Spectral Energy Distribution Fitting of Hetdex Pilot Survey Ly-alpha Emitters in Cosmos and Goods-N

NASA Technical Reports Server (NTRS)

Hagen, Alex; Ciardullo, Robin; Cronwall, Caryl; Acquaviva, Viviana; Bridge, Joanna; Zeimann, Gregory R.; Blanc, Guillermo; Bond, Nicholas; Finkelstein, Steven L.; Song, Mimi;

Continued observations of the H Ly alpha emission from Uranus

NASA Technical Reports Server (NTRS)

Clarke, J.; Durrance, S.; Moos, W.; Murthy, J.; Atreya, S.; Barnes, A.; Mihalov, J.; Belcher, J.; Festou, M.; Imhoff, C.

1986-01-01

Observations of Uranus obtained over four years with the IUE Observatory supports the initial identification of a bright H Ly alpha flux which varies independently of the solar H Ly alpha flux, implying a largely self-excited emission. An average brightness of 1400 Rayleighs is derived, and limits for the possible contribution by reflected solar H Ly alpha emission, estimated to be about 200 Rayleighs, suggest that the remaining self-excited emission is produced by an aurora. Based on comparison with solar wind measurements obtained in the vicinity of Uranus by Voyager 2 and Pioneer 11, no evidence for correlation between the solar wind density and the H Ly alpha brightness is found. The upper limit to H2 emission gives a lower limit to the ratio of H Ly alpha/H2 emissions of about 2.4, suggesting that the precipitating particles may be significantly less energetic on Uranus than those responsible for the aurora on Jupiter. The average power in precipitating particles is estimated to be of the order of 10 to the 12th W.

Lyman alpha radiation in external galaxies

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Mckee, Christopher F.

1990-01-01

The Ly alpha line of atomic hydrogen is often a luminous component of the radiation emitted by distant galaxies. Except for those galaxies which have a substantial central source of non-stellar ionizing radiation, most of the Ly alpha radiation emitted by galaxies is generated within regions of the interstellar medium which are photoionized by starlight. Conversely, much of the energy radiated by photoionized regions is carried by the Ly alpha line. Only hot, massive stars are capable of ionizing hydrogen in the interstellar medium which surrounds them, and because such stars are necessarily short-lived, Ly alpha emission traces regions of active star formation. Researchers argue that the strength of the Ly alpha emission observed from external galaxies may be used to estimate quantitatively the dust content of the emitting region, while the Ly alpha line profile is sensitive to the presence of shock waves. Interstellar dust particles and shock waves are intimately associated with the process of star formation in two senses. First, both dust particles and shock waves owe their existence to stellar activity; second, they may both serve as agents which facilitate the formation of stars, shocks by triggering gravitational instabilities in the interstellar gas that they compress, and dust by shielding star-forming molecular clouds from the ionizing and dissociative effects of external UV radiation. By using Ly alpha observations as a probe of the dust content in diffuse gas at high redshift, we might hope to learn about the earliest epochs of star formation.

Anomalous Temporal Behaviour of Broadband Ly Alpha Observations During Solar Flares from SDO/EVE

NASA Technical Reports Server (NTRS)

Milligan, Ryan O.; Chamberlin, Phillip C.

2016-01-01

Although it is the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly-alpha) emission during solar flares in recent years. However, the few examples that do exist have shown Ly-alpha emission to be a substantial radiator of the total energy budget of solar flares (of the order of 10 percent). It is also a known driver of fluctuations in the Earth's ionosphere. The EUV (Extreme Ultra-Violet) Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) now provides broadband, photometric Ly-alpha data at 10-second cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H-alpha, Ly-beta, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission and not during the impulsive phase when energy deposition in the chromosphere (often assumed to be in the form of non-thermal electrons) is greatest. The time derivative of Ly-alpha lightcurves also appears to resemble that of the time derivative of soft X-rays, reminiscent of the Neupert effect. Given that spectrally-resolved Ly-alpha observations during flares from SORCE / SOLSTICE (Solar Radiation and Climate Experiment / Solar Stellar Irradiance Comparison Experiment) peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines andor continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting broadband Ly-alpha observations of solar flares. Comparisons have also been made with other broadband Ly-alpha photometers such as PROBA2 (Project for On-Board Autonomy-2) / LYRA (Lyman Alpha Radiometer) and GOES (Geostationary Operational Environmental Satellite) / EUVE (Extreme Ultraviolet Explorer).

The Ly(alpha) Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage

NASA Technical Reports Server (NTRS)

Martin, Crystal L.; Dijkstra, Mark; Henry, Alaina L.; Soto, Kurt T.; Danforth, Charles W.; Wong, Joseph

2015-01-01

We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Ly(alpha) emission from eight ULIRGs and the companion to IRAS09583+4714. In contrast to the P Cygni profiles often seen in galaxy spectra, the Ly(alpha) profiles exhibit prominent, blueshifted emission out to Doppler shifts exceeding -1000 km/s in three H II-dominated and two AGN-dominated ULIRGs. To better understand the role of resonance scattering in shaping the Ly(alpha) line profiles, we directly compare them to non-resonant emission lines in optical spectra. We find that the line wings are already present in the intrinsic nebular spectra, and scattering merely enhances the wings relative to the line core. The Ly(alpha) attenuation (as measured in the COS aperture) ranges from that of the far-UV continuum to over 100 times more. A simple radiative transfer model suggests the Ly(alpha) photons escape through cavities which have low column densities of neutral hydrogen and become optically thin to the Lyman continuum in the most advanced mergers. We show that the properties of the highly blueshifted line wings on the Ly(alpha) and optical emission-line profiles are consistent with emission from clumps of gas condensing out of a fast, hot wind. The luminosity of the Ly(alpha) emission increases nonlinearly with the ULIRG bolometric luminosity and represents about 0.1-1% of the radiative cooling from the hot winds in the H II-dominated ULIRGs.

Toward unbiased determination of the redshift evolution of Lyman-alpha forest clouds

NASA Technical Reports Server (NTRS)

Lu, Limin; Zuo, Lin

1994-01-01

The possibility of using D(sub A), the mean depression of a quasar spectrum due to Ly-alpha forest absorption, to study the number density evolution of the Ly-alpha forest clouds is examined in some detail. Current D(sub A) measurements are made against a continuum that is a power-law extrapolation from the continuum longward of Ly-alpha emission. Compared to the line-counting approach, the D(sub A)-method has the advantage that the D(sub A) measurements are not affected by line-blending effects. However, we find using low-redshift quasar spectra obtained with the Hubble Space Telescope (HST), where the true continuum in the Ly-alpha forest can be estimated fairly reliably because of the much lower density of the Ly-alpha forest lines, that the extrapolated continuum often deviates systematically from the true continuum in the forest region. Such systematic continuum errors introduce large errors in the D(sub A) measurements. The current D(sub A) measurements may also be significantly biased by the possible presence of the Gunn-Peterson absorption. We propose a modification to the existing D(sub A)-method, namely, to measure D(sub A) against a locally established continuum in the Ly-alpha forest. Under conditions that the quasar spectrum has good resolution and S/N to allow for a reliable estimate of the local continuum in the Ly-alpha forest, the modified D(sub A) measurements should be largely free of the systematic uncertainties suffered by the existing D(sub A) measurements. We also introduce a formalism based on the work of Zuo (1993) to simplify the application of the D(sub A)-method(s) to real data. We discuss the merits and limitations of the modified D(sub A)-method, and conclude that it is a useful alternative. Our findings that the extrapolated continuum from longward of Ly-alpha emission often deviates systematically from the true continuum in the Ly-alpha forest present a major problem in the study of the Gunn-Peterson absorption.

A quadruple quasar coincident with a giant Ly-alpha nebula and a protocluster at z=2

NASA Astrophysics Data System (ADS)

Vignali, Cristian

2016-09-01

We propose to observe the only known quadruple AGN system in the Universe, embedded in a giant Ly-alpha nebula at z 2. These active nuclei and the large number of Ly-alpha emitting galaxies at the same redshift are clear indications that this is one of the most overdense protoclusters known z 2. We request a 140 ks Chandra exposure to (a) define the basic X-ray properties of all the AGN and then their bolometric luminosities and Eddington ratios, and compare these with those of "isolated" quasars at similar redshifts/luminosities; (b) detect the hot gas emission in the protocluster. Chandra is unique for this investigation: the close (few arcsec) distance of some of the AGN needs high spatial resolution, and the extended emission requires low background contribution.

Intergalactic Hydrogen Clouds at Low Redshift: Connections to Voids and Dwarf Galaxies

NASA Technical Reports Server (NTRS)

Shull, J. Michael; Stocke, John T.; Penton, Steve

1996-01-01

We provide new post-COSTAR data on one sightline (Mrk 421) and updated data from another (I Zw 1) from our Hubble Space Telescope (HST) survey of intergalactic Ly(alpha) clouds located along sightlines to four bright quasars passing through well-mapped galaxy voids (16000 km/s pathlength) and superclusters (18000 km/s). We report two more definite detections of low-redshift Ly(alpha) clouds in voids: one at 3047 km/s (heliocentric) toward Mrk 421 and a second just beyond the Local Supercluster at 2861 km/s toward I Zw 1, confirming our earlier discovery of Ly(alpha) absorption clouds in voids (Stocke et al., ApJ, 451, 24). We have now identified ten definite and one probable low-redshift neutral hydrogen absorption clouds toward four targets, a frequency of approximately one absorber every 3400 km/s above 10(exp 12.7/sq cm column density. Of these ten absorption systems, three lie within voids; the probable absorber also lies in a void. Thus, the tendency of Ly(alpha) absorbers to 'avoid the voids' is not as clear as we found previously. If the Ly(alpha) clouds are approximated as homogeneous spheres of 100 kpc radius, their masses are approximately 10(exp 9)solar mass (about 0.01 times that of bright L* galaxies) and they are 40 times more numerous, comparable to the density of dwarf galaxies and of low-mass halos in numerical CDM simulations. The Ly(alpha) clouds contribute a fraction Omega(sub cl)approximately equals 0.003/h(sub 75) to the closure density of the universe, comparable to that of luminous matter. These clouds probably require a substantial amount of nonbaryonic dark matter for gravitational binding. They may represent extended haloes of low-mass protogalaxies which have not experienced significant star formation or low-mass dwarf galaxies whose star formation ceased long ago, but blew out significant gaseous material.

Ly-alpha polarimeter design for CLASP rocket experiment

NASA Astrophysics Data System (ADS)

Kubo, M.; Watanabe, H.; Narukage, N.; Ishikawa, R.; Bando, T.; Kano, R.; Tsuneta, S.; Kobayashi, K.; Ichimoto, K.; Trujillo Bueno, J.; Song, D.

2011-12-01

A sounding-rocket program called the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is proposed to be launched in the Summer of 2014. CLASP will observe the upper solar chromosphere in Ly-alpha (121.567 nm), aiming to detect the linear polarization signal produced by scattering processes and the Hanle effect for the first time. The CLASP needs a rotating half-waveplate and a polarization analyzer working at the Ly-alpha wavelength to measure the linear polarization signal. We select Magnesium Fluoride (MgF2) as a material of the optical components because of its birefringent property and high transparency at UV wavelength. We have confirmed that the reflection at the Brewster's Angle of MgF2 plate is a good polarization analyzer for the Ly-alpha line by deriving its ordinary refractive index and extinction coefficient along the ordinary and extraordinary axes. These optical parameters are calculated with a least-square fitting in such a way that the reflectance and transmittance satisfy the Kramers-Kronig relation. The reflectance and transmittance against oblique incident angles for the s-polarized and the p-polarized light are measured using the synchrotron beamline at the Ultraviolet Synchrotron Orbital Radiation Facility (UVSOR). We have also measured a retardation of a zeroth-order waveplate made of MgF2. The thickness difference of the waveplate is 14.57 um.This waveplate works as a half-waveplate at 121.74 nm. From this measurement, we estimate that a waveplate with the thickness difference of 15.71 um will work as a half-waveplate at the Ly-alpha wavelength. We have developed a rotating waveplate - polarization analyzer system called a prototype of CLASP polarimeter, and input the perfect Stokes Q and U signals. The modulation patterns that are consistent with the theoretical prediction are successfully obtained in both cases.

DEEP LBT/LUCI SPECTROSCOPY OF AN Ly{alpha} EMITTER CANDIDATE AT z {approx_equal} 7.7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang Linhua; Bian Fuyan; Fan Xiaohui

2013-07-01

We present deep spectroscopic observations of an Ly{alpha} emitter (LAE) candidate at z {approx_equal} 7.7 using the infrared spectrograph LUCI on the 2 Multiplication-Sign 8.4 m Large Binocular Telescope (LBT). The candidate is the brightest among the four z {approx_equal} 7.7 LAE candidates found in a narrowband imaging survey by Krug et al. Our spectroscopic data include a total of 7.5 hr of integration with LBT/LUCI and are deep enough to significantly (3.2{sigma}-4.9{sigma}) detect the Ly{alpha} emission line of this candidate based on its Ly{alpha} flux 1.2 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} estimated from the narrowband photometry.more » However, we do not find any convincing signal at the expected position of its Ly{alpha} emission line, suggesting that this source is not an LAE at z {approx_equal} 7.7. The non-detection in this work, together with the previous studies of z {approx_equal} 7.7 LAEs, puts a strong constraint on the bright-end Ly{alpha} luminosity function (LF) at z {approx_equal} 7.7. We find a rapid evolution of the Ly{alpha} LF from z {approx_equal} 6.5 to 7.7: the upper limit of the z {approx_equal} 7.7 LF is more than five times lower than the z {approx_equal} 6.5 LF at the bright end (f{>=} 1.0 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} or L{>=} 6.9 Multiplication-Sign 10{sup 42} erg s{sup -1}). This is likely caused by an increasing neutral fraction in the intergalactic medium that substantially attenuates Ly{alpha} emission at z {approx_equal} 7.7.« less

Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

NASA Technical Reports Server (NTRS)

Weiler, E. J.

1978-01-01

Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

SPECTROSCOPIC CONFIRMATION OF FAINT LYMAN BREAK GALAXIES NEAR REDSHIFT FIVE IN THE HUBBLE ULTRA DEEP FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth

We present the faintest spectroscopically confirmed sample of z {approx} 5 Lyman break galaxies (LBGs) to date. The sample is based on slitless grism spectra of the Hubble Ultra Deep Field region from the Grism ACS Program for Extragalactic Science (GRAPES) and Probing Evolution and Reionization Spectroscopically (PEARS) projects, using the G800L grism on the Hubble Space Telescope Advanced Camera for Surveys. We report here confirmations of 39 galaxies, preselected as candidate LBGs using photometric selection criteria. We compare a 'traditional' V-dropout selection, based on the work of Giavalisco et al., to a more liberal one (with V - imore » > 0.9), and find that the traditional criteria are about 64% complete and 81% reliable. We also study the Ly{alpha} emission properties of our sample. We find that Ly{alpha} emission is detected in {approx}1/4 of the sample, and that the liberal V-dropout color selection includes {approx}55% of previously published line-selected Ly{alpha} sources. Finally, we examine our stacked two-dimensional spectra. We demonstrate that strong, spatially extended ({approx}1'') Ly{alpha} emission is not a generic property of these LBGs, but that a modest extension of the Ly{alpha} photosphere (compared to the starlight) may be present in those galaxies with prominent Ly{alpha} emission.« less

Design and Fabrication of the All-Reflecting H-Lyman alpha Coronagraph/Polarimeter

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Johnson, R. Barry; Fineschi, Silvano; Walker, Arthur B. C., Jr.; Baker, Phillip C.; Zukic , Muamer; Kim, Jongmin

1993-01-01

We have designed, analyzed, and are now fabricating an All-Reflecting H-Lyman alpha Coronagraph/Polarimeter for solar research. This new instrument operates in a narrow bandpass centered at lambda 1215.7 A-the neutral hydrogen Lyman alpha (Ly-alpha) line. It is shorter and faster than the telescope which produced solar Ly-alpha images as a part of the MSSTA payload that was launched on May 13, 1991. The Ly-alpha line is produced and linearly polarized in the solar corona by resonance scattering, and the presence of a magnetic field modifies this polarization according to the Hanle effect. The Lyman alpha Coronagraph/Polarimeter instrument has been designed to measure coronal magnetic fields by interpreting, via the Hanle effect, the measured linear polarization of the coronal Ly-alpha line. Ultrasmooth mirrors, polarizers, and filters are being flow-polished for this instrument from CVD silicon carbide substrates. These optical components will be coated using advanced induced transmission and absorption thin film multilayer coatings, to optimize the reflectivity and polarization properties at 1215.7 A. We describe some of the solar imaging results obtained with the MSSTA Lyman alpha coronagraph. We also discuss the optical design parameters and fabrication plans for the All-Reflecting H-Lyman alpha Coronagraph/Polarimeter.

Determining coronal electron temperatures from observations with UVCS/SOHO

NASA Technical Reports Server (NTRS)

Fineschi, S.; Esser, R.; Habbal, S. R.; Karovska, M.; Romoli, M.; Strachan, L.; Kohl, J. L.; Huber, M. C. E.

1995-01-01

The electron temperature is a fundamental physical parameter of the coronal plasma. Currently, there are no direct measurements of this quantity in the extended corona. Observations with the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the upcoming Solar and Heliospheric Observatory (SOHO) mission can provide the most direct determination of the electron kinetic temperature (or, more precisely, the electron velocity distribution along the line of sight). This measurement is based on the observation of the Thomson-scattered Lyman alpha (Ly-alpha) profile. This observation is made particularly challenging by the fact that the integrated intensity of the electron-scattered Ly-alpha line is about 10(exp 3) times fainter than that of the resonantly-scattered Ly-alpha component. In addition, the former is distributed across 50 A (FWHM), unlike the latter that is concentrated in 1 A. These facts impose stringent requirements on the stray-light rejection properties of the coronagraph/spectrometer, and in particular on the requirements for the grating. We make use of laboratory measurements of the UVCS Ly-alpha grating stray-light, and of simulated electron-scattered Ly-alpha profiles to estimate the expected confidence levels of electron temperature determination. Models of different structures typical of the corona (e.g., streamers, coronal holes) are used for this parameter study.

Intense Ly-alpha emission from Uranus

NASA Technical Reports Server (NTRS)

Durrance, S. T.; Moos, H. W.

1982-01-01

The existence of intense atomic hydrogen Ly-alpha emission from Uranus is demonstrated here by utilizing the monochromatic imaging capabilities of the International Ultraviolet Explorer (IUE) spectrograph. Observations show increased emission in the vicinity of Uranus superimposed on the geocoronal/interplanetary background. If resonant scattering of solar Ly-alpha is the source of the 1.6 + or - 0.4 kR disk averaged brightness, then very high column densities of atomic H above the absorbing methane are required. Precipitation of trapped charged particles, i.e., aurora, could explain the emissions. This would imply a planetary magnetic field.

Far-ultraviolet and optical spectrophotometry of X-ray selected Seyfert galaxies

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Bowyer, S.; Grewing, M.

1986-01-01

Five X-ray selected Seyfert galaxies were examined via near-simultaneous far-ultraviolet and optical spectrophotometry in an effort to test models for excitation of emission lines by X-ray and ultraviolet continuum photoionization. The observed Ly-alpha/H-beta ratio in the present sample averages 22, with an increase found toward the high-velocity wings of the H lines in the spectrum of at least one of the Seyfert I nuclei. It is suggested that Seyfert galaxies with the most high-velocity gas exhibit the highest Ly-alpha/H-beta ratios at all velocities in the line profiles, and that sometimes this ratio may be highest for the highest velocity material in the broad-line clouds. Since broad-lined objects are least affected by Ly-alpha trapping effects, they have Ly-alpha/H-beta ratios much closer to those predicted by early photoionization calculations.

IUE high resolution spectrophotometry of H Ly alpha emission from the local interstellar medium

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Bowyer, S.; Fahr, H. J.; Lay, G.

1984-01-01

IUE high dispersion spectra of resonantly scattered solar Ly alpha emission from H moving into the solar system with the local interstellar wind are reported which are based on observations conducted in April 1981 and April 1983. A heliocentric velocity of -29 + or - 5 km/s has been observed from the ISW component along with a surface brightness which has decreased from about 1000 to 800 Rayleighs over the two-year interval. A preliminary derivation of the velocity of the ISM at large distances from the sun yields a value of 25.6 + or - 5 km/s.

High-Reflectivity Multi-Layer Coatings for the CLASP Sounding Rocket Project

NASA Technical Reports Server (NTRS)

Narukage, Noriyuki; Kano, Ryohei; Bando, Takamasa; Ishikawa, Ryoko; Kubo, Masahito; Katsukawa, Yukio; Ishikawa, Shin-nosuke; Kobiki, Toshihiko; Giono, Gabriel; Auchere, Frederic;

Ultraviolet observations of cool stars. IV - Intensities of Lyman-alpha and Mg II in epsilon Pegasi and epsilon Eridani, and line width-luminosity correlations

NASA Technical Reports Server (NTRS)

Mcclintock, W.; Linsky, J. L.; Henry, R. C.; Moos, H. W.

1975-01-01

A spectrometer on the Copernicus satellite has been used to confirm the existence of a line width-luminosity relation for the Ly-alpha and Mg II 2800-A chromospheric emission lines in K-type stars by observation of a K2 dwarf (epsilon Eri) and a K2 supergiant (epsilon Peg). Combined with previously reported observations of lines in three K giants (alpha Boo, alpha Tau, and beta Gem), the data are consistent with an identical dependence of line width on absolute visual magnitude for the Ca II K, Ly-alpha, and Mg II 2795-A lines. Surface fluxes of Ly-alpha, Mg II 2800-A, and O V 1218-A (upper limit) for epsilon Eri, and of Mg II 2800-A for epsilon Peg are also compared with values reported previously for the three giant stars.

A Luminosity Function of Ly(alpha)-Emitting Galaxies at Z [Approx. Equal to] 4.5(Sup 1),(Sup 2)

NASA Technical Reports Server (NTRS)

Dawson, Steve; Rhoads, James E.; Malhotra, Sangeeta; Stern, Daniel; Wang, JunXian; Dey, Arjun; Spinrad, Hyron; Jannuzi, Buell T.

2007-01-01

We present a catalog of 59 z [approx. equal to] 4:5 Ly(alpha)-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Are (LALA) narrowband imaging survey.We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of approx.76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z [approx. equal to] 4:5 Ly(alpha)- emitting galaxies in the [approx. equal to] 0.7 deg(exp 2) covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the co rest-frame equivalent widths (W(sub lambda)(sup rest)) that exceed the maximum predicted for normal stellar populations: 17%-31%(93%confidence) of the detected galaxies show (W(sub lambda)(sup rest)) 12%-27% (90% confidence) show (W(sub lambda)(sup rest)) > 240 A. We construct a luminosity function of z [approx. equal to] 4.5 Ly(alpha) emission lines for comparison to Ly(alpha) luminosity function < 6.6. We find no significant evidence for Ly(alpha) luminosity function evolution from z [approx. equal to] 3 to z [approx. equal to] 6. This result supports the conclusion that the intergalactic me largely reionized from the local universe out to z [approx. equal to] 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z approx. 3 an z approx. 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.

Low redshift Lyman alpha absorption lines and the dark matter halos of disk galaxies

NASA Technical Reports Server (NTRS)

Maloney, Philip

1993-01-01

Recent observations using the Hubble Space Telescope of the z = 0.156 QSO 3C 273 have discovered a surprisingly large number of Ly-alpha absorption lines. In particular, Morris et al. found 9 certain and 7 possible Ly-alpha lines with equivalent widths above 25 mA. This is much larger (by a factor of 5-10) than the number expected from extrapolation of the high-redshift behavior of the Ly-alpha forest. Within the context of pressure-confined models for the Ly-alpha clouds, this behavior can be understood if the ionizing background declines sharply between z is approximately 2 and z is approximately 0. However, this requires that the ionizing photon flux drop as rapidly as the QSO volume emissivity; moreover, the absorbers must have a space density n(sub O) is approximately 2.6(N/10)h/((D/100 kpc)(sup 2)) Mpc(sup -3) where D is the present-day diameter of the absorbers. It is somewhat surprising that such necessarily fragile objects could have survived in such numbers to the present day. It is shown that it is plausible that the atomic hydrogen extents of spiral and irregular galaxies are large enough to produce the observed number of Ly-alpha absorption lines toward 3C 273, and that the neutral column densities and doppler b-values expected under these conditions fall in the range found by Morris et al. (1991).

Can Gas Outflows Explain The Strong Lyα Emission Of Lyman Alpha Emitters?

NASA Astrophysics Data System (ADS)

Hashimoto, Takuya; Ouchi, M.; Shimasaku, K.; Nakajima, K.; Ono, Y.; Rauch, M.

2012-05-01

Lyman alpha emitters (LAEs) are galaxies commonly seen at high redshift, probably playing an important role in galaxy evolution as building blocks of massive galaxies. The most interesting feature of LAEs is strong Lyα emission, because Lyα photons produced in a galaxy are expected to be easily absorbed by dust in the ISM before escaping the galaxy due to their resonant nature. Previous studies have suggested that outflow may help their escape thanks to reduced cross sections of outflowing (ie, redshifted) neutral hydrogen atoms. Although the presence of outflows can be examined from the offset of the Lyα emission from the systemic velocity defined by Hα emission, there are only four LAEs with reliable detection of Hα emission. We present the results of Magellan/MMIRS and Keck/NIRSPEC spectroscopic observations of five LAEs at z˜2.2 from our wide-field narrow-band survey with Subaru/Suprime-Cam. We successfully detect Hα emission for five objects. After eliminating an AGN contaminated object, we measure the velocityoffset between Lyα and Hα (Δ v_Lyα) for the remaining four, to find that three have a positive offset, suggesting an outflow. Since three among the four from the the literature also have an outflow, we conclude that ˜75% of LAEs have an outflow, with velocities of 75-280 km/s. We then use these eight LAEs to examine how the Lyα strength defined by Lyα escape fraction (f_esc) and/or Lyα equivalent width (EW(Lyα)) depend on other physical quantities including those derived from SED fitting. Contrary to our expectation, we find that both f_esc and EW(Lyα) decrease with Δ v_Lyα. Thus, although LAEs do have outflow, high outflow velocities are not the primary cause of strong Lyα emission. We also find that the Lyα strength does not depend on E(B-V). However, we find that objects with a clumpier gas distribution may have higher f_esc.

Observations of Interstellar HI Toward Nearby Late-type Stars

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1984-01-01

High-disperson Copernicus and IUE observations of chromospheric Ly alpha emission are used to study the distribution of HI in the local interstellar medium. Interstellar parameters are derived toward 3 stars within 5 pc of the Sun, and upper limits are given for the Ly alpha flux from 9 other stars within 10 pc.

The Lyman alpha reference sample. VII. Spatially resolved Hα kinematics

NASA Astrophysics Data System (ADS)

Herenz, Edmund Christian; Gruyters, Pieter; Orlitova, Ivana; Hayes, Matthew; Östlin, Göran; Cannon, John M.; Roth, Martin M.; Bik, Arjan; Pardy, Stephen; Otí-Floranes, Héctor; Mas-Hesse, J. Miguel; Adamo, Angela; Atek, Hakim; Duval, Florent; Guaita, Lucia; Kunth, Daniel; Laursen, Peter; Melinder, Jens; Puschnig, Johannes; Rivera-Thorsen, Thøger E.; Schaerer, Daniel; Verhamme, Anne

2016-03-01

We present integral field spectroscopic observations with the Potsdam Multi-Aperture Spectrophotometer of all 14 galaxies in the z ~ 0.1 Lyman Alpha Reference Sample (LARS). We produce 2D line-of-sight velocity maps and velocity dispersion maps from the Balmer α (Hα) emission in our data cubes. These maps trace the spectral and spatial properties of the LARS galaxies' intrinsic Lyα radiation field. We show our kinematic maps that are spatially registered onto the Hubble Space Telescope Hα and Lyman α (Lyα) images. We can conjecture a causal connection between spatially resolved Hα kinematics and Lyα photometry for individual galaxies, however, no general trend can be established for the whole sample. Furthermore, we compute the intrinsic velocity dispersion σ0, the shearing velocity vshear, and the vshear/σ0 ratio from our kinematic maps. In general LARS galaxies are characterised by high intrinsic velocity dispersions (54 km s-1 median) and low shearing velocities (65 km s-1 median). The vshear/σ0 values range from 0.5 to 3.2 with an average of 1.5. It is noteworthy that five galaxies of the sample are dispersion-dominated systems with vshear/σ0< 1, and are thus kinematically similar to turbulent star-forming galaxies seen at high redshift. When linking our kinematical statistics to the global LARS Lyα properties, we find that dispersion-dominated systems show higher Lyα equivalent widths and higher Lyα escape fractions than systems with vshear/σ0> 1. Our result indicates that turbulence in actively star-forming systems is causally connected to interstellar medium conditions that favour an escape of Lyα radiation. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).The reduced data cubes (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A78

High-Velocity Ly(Alpha) Emission from SMR 1987A

NASA Technical Reports Server (NTRS)

Michael, Eli; McCray, Richard; Borkowski, Kazimierz J.; Pun, Chu S. J.; Sonneborn, George

1998-01-01

The high-velocity Ly(Alpha) emission from SN 1987A observed with the Space Telescope Imaging Spectrograph (STIS) evidently comes from a reverse shock formed where the outer envelope of SN 1987A strikes ionized gas inside the inner circumstellar ring. The observations can be explained by a simple kinematic model, in which the Ly(Alpha) emission comes from hydrogen atoms with radial velocity approximately 15,000 km s(exp -1) crossing a reverse shock in the shape of a slightly prolate ellipsoid with equatorial radius 4.8 x 10(exp 17) cm or approximately 80% of the distance to the inner surface of the inner ring. N v double Lambda 1239, 1243 emission, if present, has a net luminosity approximately less than 30% times that of the Ly(Alpha) emission. Future STIS observations should enable us to predict the time of impact with the inner ring and to determine unambiguously whether or not N v emission is present. These observations will offer a unique opportunity to probe the structure of SN 1987A's circumstellar environment and the hydrodynamics and kinetics of very fast shocks.

Clasp/SJ Observation of Time Variations of Lyman-Alpha Emissions in a Solar Active Region

NASA Technical Reports Server (NTRS)

Ishikawa, S.; Kubo, M.; Katsukawa, Y.; Kano, R.; Narukage, N.; Ishikawa, R.; Bando, T.; Winebarger, A.; Kobayashi, K.; Trujillo Bueno, J.;

Ultraviolet observations of cool stars. V - The local density of interstellar matter

NASA Technical Reports Server (NTRS)

Mcclintock, W.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1976-01-01

A high-resolution Copernicus observation of the chromospheric Ly-alpha emission line of the nearby (3.3 pc) K dwarf epsilon Eri sets limits on the velocity, the velocity dispersion, and the density of atomic hydrogen in the local interstellar medium. Analysis shows that the interstellar Ly-alpha absorption is on the flat portion of the curve of growth. An upper limit of 0.12 per cu cm is derived for the atomic-hydrogen density. The value of this density is 0.08 (plus or minus 0.04 per cu cm if the velocity-dispersion parameter is 9 km/s, corresponding to a temperature of 5000 K. Also, the interstellar deuterium Ly-alpha line may be present in the spectrum.

The Lyman-alpha signature of the first galaxies

NASA Astrophysics Data System (ADS)

Smith, Aaron

2018-01-01

Radiation from the first stars and galaxies initiated the dramatic phase transition marking an end to the cosmic dark ages. The emission and absorption signatures from the Lyman-alpha (Lyα) transition of neutral hydrogen have been indispensable in extending the observational frontier for high-redshift galaxies into the epoch of reionization. Lyα radiative transfer provides clues about the processes leading to Lyα escape from individual galaxies and the subsequent transmission through the intergalactic medium. Cosmological simulations incorporating Lyα radiative transfer enhance our understanding of fundamental physics by supplying the inferred spectra and feedback on the gas. In this talk, I will discuss the dynamical impact of Lyα radiation pressure on galaxy formation throughout cosmic reionization with the first fully coupled Lyα radiation-hydrodynamics simulations. Based on a suite of spherically symmetric models and high-resolution ab initio cosmological simulations we find that Lyα radiation pressure is dynamically important during the assembly of direct collapse black holes (DCBHs), which may be the seeds of the first supermassive black holes in the universe. Finally, I will discuss recent advances in Lyα modeling based on current state-of-the-art simulations and observational insights.

Variability of Lyman-alpha emission from Jupiter

NASA Technical Reports Server (NTRS)

1979-01-01

The Jovian Lyman-alpha emission line was again observed in 1978 using the high resolution spectrometer on the Copernicus satellite. In intensity of 8.4+3.0 kilo Rayleighs was measured. This value represents a significant increase in intensity over previous (1976) Copernicus observations, but is lower than the recent (1979) values obtained by Voyager I and IUE. The increase in intensity was accompanied by a significant increase in line width, giving strong support to the theory that the emission results from resonant scattering of the solar Ly-alpha line by H atoms in the upper Jovian atmosphere. The strength of Jovian Ly-alpha emission correlates well with the level of solar activity. The solar extreme ultraviolet radiation varies with the solar cycle. This radiation causes the dissociation of H2 and CH4 into H atoms in the Jovian atmosphere. Therefore, in times of high solar activity, the H column density will increase, causing the observed stronger Jovian Ly-alpha emission.

A FAST FLARE AND DIRECT REDSHIFT CONSTRAINT IN FAR-ULTRAVIOLET SPECTRA OF THE BLAZAR S5 0716+714

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danforth, Charles W.; Nalewajko, Krzysztof; France, Kevin

The BL Lacertae object S5 0716+714 is one of the most studied blazars on the sky due to its active variability and brightness in many bands, including very-high-energy gamma rays. We present here two serendipitous results from recent far-ultraviolet spectroscopic observations by the Cosmic Origins Spectrograph onboard the Hubble Space Telescope (HST). First, during the course of our 7.3 hr HST observations, the blazar increased in flux rapidly by {approx}40% (-0.45 mag hr{sup -1}) followed by a slower decline (+0.36 mag hr{sup -1}) to previous FUV flux levels. We model this flare using asymmetric flare templates and constrain the physicalmore » size and energetics of the emitting region. Furthermore, the spectral index of the object softens considerably during the course of the flare from {alpha}{sub {nu}} Almost-Equal-To -1.0 to {alpha}{sub {nu}} Almost-Equal-To -1.4. Second, we constrain the source redshift directly using the {approx}30 intervening absorption systems. A system at z = 0.2315 is detected in Ly{alpha}, Ly{beta}, O VI, and N V and defines the lower bound on the source redshift. No absorbers are seen in the remaining spectral coverage (0.2315 < z {sub Ly{alpha}} {approx}< 0.47) and we set a statistical upper bound of z < 0.322 (95% confidence) on the blazar. This is the first direct redshift limit for this object and is consistent with literature estimates of z = 0.31 {+-} 0.08 based on the detection of a host galaxy.« less

Lyman Alpha Searches at Redshift Z>7

NASA Astrophysics Data System (ADS)

Willis, Jon

2007-05-01

The ZEN survey is a narrow J-band survey for Ly-alpha emitting galaxies at z > 7. I will briefly review the pros and cons of narrow band observations before summarising the ZEN1 and ZEN2 searches based upon deep ISAAC pointings. I will then present ZEN3, consisting of wide field, narrow band observations of two fields using the CFHT WIRCam facility. I will conclude by reviewing the current sample of candidates and what we have learned about the z > 7 Ly-alpha emitting population.

The Universe at Moderate Redshift

NASA Technical Reports Server (NTRS)

Cen, Renyue; Ostriker, Jeremiah P.

1997-01-01

The report covers the work done in the past year and a wide range of fields including properties of clusters of galaxies; topological properties of galaxy distributions in terms of galaxy types; patterns of gravitational nonlinear clustering process; development of a ray tracing algorithm to study the gravitational lensing phenomenon by galaxies, clusters and large-scale structure, one of whose applications being the effects of weak gravitational lensing by large-scale structure on the determination of q(0); the origin of magnetic fields on the galactic and cluster scales; the topological properties of Ly(alpha) clouds the Ly(alpha) optical depth distribution; clustering properties of Ly(alpha) clouds; and a determination (lower bound) of Omega(b) based on the observed Ly(alpha) forest flux distribution. In the coming year, we plan to continue the investigation of Ly(alpha) clouds using larger dynamic range (about a factor of two) and better simulations (with more input physics included) than what we have now. We will study the properties of galaxies on 1 - 100h(sup -1) Mpc scales using our state-of-the-art large scale galaxy formation simulations of various cosmological models, which will have a resolution about a factor of 5 (in each dimension) better than our current, best simulations. We will plan to study the properties of X-ray clusters using unprecedented, very high dynamic range (20,000) simulations which will enable us to resolve the cores of clusters while keeping the simulation volume sufficiently large to ensure a statistically fair sample of the objects of interest. The details of the last year's works are now described.

A 21 Centimeter Absorber Identified with a Spiral Galaxy: Hubble Space Telescope Faint Object Spectrograph and Wide-Field Camera Observations of 3CR 196

NASA Technical Reports Server (NTRS)

Cohen, Ross D.; Beaver, E. A.; Diplas, Athanassios; Junkkarinen, Vesa T.; Barlow, Thomas A.; Lyons, Ronald W.

1996-01-01

We present imaging and spectroscopy of the quasar 3CR 196 (z(sub e) = 0.871), which has 21 cm and optical absorption at z(sub a) = 0.437. We observed the region of Ly alpha absorption in 3CR 196 at z(sub a) = 0.437 with the Faint Object Spectrograph on the Hubble Space Telescope. This region of the spectrum is complicated because of the presence of a Lyman limit and strong lines from a z(sub a) approx. z(sub e) system. We conclude that there is Ly alpha absorption with an H I column density greater than 2.7 x 10(exp 19) cm(exp -2) and most probably 1.5 x 10(exp 20) cm(exp -2). Based on the existence of the high H I column density along both the optical and radio lines of sight, separated by more than 15 kpc, we conclude that the Ly alpha absorption must arise in a system comparable in size to the gaseous disks of spiral galaxies. A barred spiral galaxy, previously reported as a diffuse object in the recent work of Boisse and Boulade, can be seen near the quasar in an image taken at 0.1 resolution with the Wide Field Planetary Camera 2 on the HST. If this galaxy is at the absorption redshift, the luminosity is approximately L(sub *) and any H I disk should extend in front of the optical quasar and radio lobes of 3CR 196, giving rise to both the Ly alpha and 21 cm absorption. In the z(sub a) approx. z(sub e) system we detect Lyman lines and the Lyman limit, as well as high ion absorption lines of C III, N V, S VI, and O VI. This absorption probably only partially covers the emission-line region. The ionization parameter is approximately 0.1. Conditions in this region may be similar to those in broad absorption line QSOs.

Measurements of Lyman-Alpha Escape From HST Far-UV Spectral SNAP Survey of 33 Starforming Galaxies: Initial Results

NASA Astrophysics Data System (ADS)

Redwine, Keith

2018-01-01

This thesis will describe and analyze far-UV spectra from nearby starforming galaxies to investigate how line features like the hydrogen Lyman-alpha (Lyα) line at 1216 Å are related to the local properties of the host galaxy. It has been suggested that Lyα can be used as a proxy for the escape of Lyman continuum (LyC) radiation, the escape of of which from bright regions of galaxies is of particular interest. Most notably, the reionization epoch of neutral atomic hydrogen in the universe over a redshift range from z∼6 to z∼12, was highly dependent on the flux of ionizing LyC photons in the interstellar and intergalactic media. Expanding our understanding of the dynamics of the Lyα escape fraction (fLyα) from the local environment of its emission could be key to determining a total LyC escape fraction (fLyC) across all morphologies of galaxies. The wide range of Lyα emitters and absorbors (occasionally both) of this Cycle 22 SNAP survey observed by the Cosmic Origins Spectrograph (COS) onboard Hubble Space Telescope (HST) provides a unique look at far-UV spectra in candidate LyC emitters. Lyα profiles are easily observable in short exposures, and line features discernable in the low-resolution G140L mode can inform and guide future observations by COS or other FUV spectroscopy.

Antibody ligation of murine Ly-6G induces neutropenia, blood flow cessation, and death via complement-dependent and independent mechanisms.

PubMed

Abbitt, Katherine B; Cotter, Matthew J; Ridger, Victoria C; Crossman, David C; Hellewell, Paul G; Norman, Keith E

2009-01-01

Ly-6G is a member of the Ly-6 family of GPI-linked proteins, which is expressed on murine neutrophils. Antibodies against Ly-6G cause neutropenia, and fatal reactions also develop if mice are primed with TNF-alpha prior to antibody treatment. We have investigated the mechanisms behind these responses to Ly-6G ligation in the belief that similar mechanisms may be involved in neutropenia and respiratory disorders associated with alloantibody ligation of the related Ly-6 family member, NB1, in humans. Neutrophil adhesion, microvascular obstruction, breathing difficulties, and death initiated by anti-Ly-6G antibodies in TNF-alpha-primed mice were shown to be highly complement-dependent, partly mediated by CD11b, CD18, and FcgammaR and associated with clustering of Ly-6G. Neutrophil depletion, on the other hand, was only partly complement-dependent and was not altered by blockade of CD11b, CD18, or FcgammaR. Unlike other neutrophil-activating agents, Ly-6G ligation did not induce neutropenia via sequestration in the lungs. Cross-linking Ly-6G mimicked the responses seen with whole antibody in vivo and also activated murine neutrophils in vitro. Although this suggests that the responses are, in part, mediated by nonspecific properties of antibody ligation, neutrophil depletion requires an additional mechanism possibly specific to the natural function of Ly-6G.

The large-scale cross-correlation of Damped Lyman alpha systems with the Lyman alpha forest: first measurements from BOSS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Font-Ribera, Andreu; Miralda-Escudé, Jordi; Arnau, Eduard

2012-11-01

We present the first measurement of the large-scale cross-correlation of Lyα forest absorption and Damped Lyman α systems (DLA), using the 9th Data Release of the Baryon Oscillation Spectroscopic Survey (BOSS). The cross-correlation is clearly detected on scales up to 40h{sup −1}Mpc and is well fitted by the linear theory prediction of the standard Cold Dark Matter model of structure formation with the expected redshift distortions, confirming its origin in the gravitational evolution of structure. The amplitude of the DLA-Lyα cross-correlation depends on only one free parameter, the bias factor of the DLA systems, once the Lyα forest bias factorsmore » are known from independent Lyα forest correlation measurements. We measure the DLA bias factor to be b{sub D} = (2.17±0.20)β{sub F}{sup 0.22}, where the Lyα forest redshift distortion parameter β{sub F} is expected to be above unity. This bias factor implies a typical host halo mass for DLAs that is much larger than expected in present DLA models, and is reproduced if the DLA cross section scales with halo mass as M{sub h}{sup α}, with α = 1.1±0.1 for β{sub F} = 1. Matching the observed DLA bias factor and rate of incidence requires that atomic gas remains extended in massive halos over larger areas than predicted in present simulations of galaxy formation, with typical DLA proper sizes larger than 20 kpc in host halos of masses ∼ 10{sup 12}M{sub ☉}. We infer that typical galaxies at z ≅ 2 to 3 are surrounded by systems of atomic clouds that are much more extended than the luminous parts of galaxies and contain ∼ 10% of the baryons in the host halo.« less

SEURAT: SPH scheme extended with ultraviolet line radiative transfer

NASA Astrophysics Data System (ADS)

Abe, Makito; Suzuki, Hiroyuki; Hasegawa, Kenji; Semelin, Benoit; Yajima, Hidenobu; Umemura, Masayuki

2018-05-01

We present a novel Lyman alpha (Ly α) radiative transfer code, SEURAT (SPH scheme Extended with Ultraviolet line RAdiative Transfer), where line scatterings are solved adaptively with the resolution of the smoothed particle hydrodynamics (SPH). The radiative transfer method implemented in SEURAT is based on a Monte Carlo algorithm in which the scattering and absorption by dust are also incorporated. We perform standard test calculations to verify the validity of the code; (i) emergent spectra from a static uniform sphere, (ii) emergent spectra from an expanding uniform sphere, and (iii) escape fraction from a dusty slab. Thereby, we demonstrate that our code solves the {Ly} α radiative transfer with sufficient accuracy. We emphasize that SEURAT can treat the transfer of {Ly} α photons even in highly complex systems that have significantly inhomogeneous density fields. The high adaptivity of SEURAT is desirable to solve the propagation of {Ly} α photons in the interstellar medium of young star-forming galaxies like {Ly} α emitters (LAEs). Thus, SEURAT provides a powerful tool to model the emergent spectra of {Ly} α emission, which can be compared to the observations of LAEs.

Time-Resolved Ultraviolet Spectroscopy of the M-Dwarf GJ 876 Exoplanetary System

NASA Technical Reports Server (NTRS)

France, Kevin; Linsky, Jeffrey L.; Tian, Feng; Froning, Cynthia S.; Roberge, Aki

2012-01-01

Extrasolar planets orbiting M-stars may represent our best chance to discover habitable worlds in the coming decade. The ultraviolet spectrum incident upon both Earth-like and Jovian planets is critically important for proper modeling of their atmospheric heating and chemistry. In order to provide more realistic inputs for atmospheric models of planets orbiting low-mass stars, we present new near- and far-ultraviolet (NUV and FUV) spectroscopy of the M-dwarf exoplanet host GJ 876 (U4V). Using the COS and STIS spectrographs aboard the Hubble Space Telescope, we have measured the 1150 - 3140 Ang. spectrum of GJ 876. We have reconstructed the stellar H I Ly-alpha emission line profile, and find that the integrated Ly-apha flux is roughly equal to the rest of the integrated flux (1150 - 1210 Ang + 1220 - 3140 Ang) in the entire ultraviolet bandpass (F(Ly-alpha)/F(FUV+NUV) approximately equals 0.7). This ratio is approximately 2500 x greater than the solar value. We describe the ultraviolet line spectrum and report surprisingly strong fluorescent emission from hot H2 (T(H2) > 2000 K). We show the light-curve of a chromospheric + transition region flare observed in several far-UV emission lines, with flare/ quiescent flux ratios :2: 10. The strong FUV radiation field of an M-star (and specifically Ly-alpha) is important for determining the abundance of O2 - and the formation of biomarkers - in the lower atmospheres of Earth-like planets in the habitable zones of low-mass stars.

Solar Lyman-Alpha Polarization Observation of the Chromosphere and Transition Region by the Sounding Rocket Experiment CLASP

NASA Technical Reports Server (NTRS)

Narukage, Noriyuki; Kano, Ryohei; Bando, Takamasa; Ishikawa, Ryoko; Kubo, Masahito; Katsukawa, Yukio; Ishikawa, Shinnosuke; Hara, Hiroshi; Suematsu, Yoshinori; Giono, Gabriel;

A Sounding Rocket Experiment for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)

NASA Astrophysics Data System (ADS)

Kubo, M.; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N.; Ishikawa, R.; Tsuneta, S.; Katsukawa, Y.; Ishikawa, S.; Suematsu, Y.; Hara, H.; Shimizu, T.; Sakao, T.; Ichimoto, K.; Goto, M.; Holloway, T.; Winebarger, A.; Cirtain, J.; De Pontieu, B.; Casini, R.; Auchère, F.; Trujillo Bueno, J.; Manso Sainz, R.; Belluzzi, L.; Asensio Ramos, A.; Štěpán, J.; Carlsson, M.

2014-10-01

A sounding-rocket experiment called the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is presently under development to measure the linear polarization profiles in the hydrogen Lyman-alpha (Lyα) line at 121.567 nm. CLASP is a vacuum-UV (VUV) spectropolarimeter to aim for first detection of the linear polarizations caused by scattering processes and the Hanle effect in the Lyα line with high accuracy (0.1%). This is a fist step for exploration of magnetic fields in the upper chromosphere and transition region of the Sun. Accurate measurements of the linear polarization signals caused by scattering processes and the Hanle effect in strong UV lines like Lyα are essential to explore with future solar telescopes the strength and structures of the magnetic field in the upper chromosphere and transition region of the Sun. The CLASP proposal has been accepted by NASA in 2012, and the flight is planned in 2015.

Line Profile of H Lyman (alpha) from Dissociative Excitation of H2 with Application to Jupiter

NASA Technical Reports Server (NTRS)

Ajello, Joseph M.; Kasnik, Isik; Ahmed, Syed M.; Clarke, John T.

1995-01-01

Observations of the H Lyman(alpha) (Ly-alpha) emission from Jupiter have shown pronounced emissions, exceeding solar fluorescence, in the polar aurora and equatorial "bulge" regions. The H Ly-alpha line profiles from these regions are broader than expected, indicating high-energy processes producing fast atoms as determined from the observed Doppler broadening. Toward understanding that process a high-resolution ultraviolet (UV) spectrometer was employed for the first measurement of the H Ly-alpha emission Doppler profile from dissociative excitation of H2 by electron impact. Analysis of the deconvolved line profile reveals the existence of a narrow central peak of 40 +/- 4 mA full width at half maximum and a broad pedestal base about 240 mA wide. Two distinct dissociation mechanisms account for this Doppler structure. Slow H(2p) atoms characterized by a distribution function with peak energy near 80 meV produce the peak profile, which is nearly independent of the electron impact energy. Slow H(2p) atoms arise from direct dissociation and predissociation of singly excited states which have a dissociation limit of 14.68 eV. The wings of H Ly-alpha arise from dissociative excitation of a series of doubly excited states which cross the Franck-Condon region between 23 and 40 eV. The profile of the wings is dependent on the electron impact energy, and the distribution function of fast H(2p) atoms is therefore dependent on the electron impact energy. The fast atom kinetic energy distribution at 100 eV electron impact energy spans the energy range from 1 to 10 eV with a peak near 4 eV. For impact energies above 23 eV the fast atoms contribute to a slightly asymmetric structure of the line profile. The absolute cross sections of the H Ly-alpha line peak and wings were measured over the range from 0 to 200 eV. Analytic model coefficients are given for the measured cross sections which can be applied to planetary atmosphere auroral and dayglow calculations. The dissociative excitation process, while one contributing process, appears insufficient by itself to explain the line broadening observed at Jupiter.

Near-Field Cosmology with Low-Mass Galaxies: Constraining the Escape of Radiation from the UV-slopes of Local Galaxies

NASA Astrophysics Data System (ADS)

Venkatesan, Aparna; Rosenberg, Jessica L.; Salzer, John Joseph; Gronke, Max; Cannon, John M.; Miller, Christopher J.; Dijkstra, Mark

2018-06-01

Low-mass galaxies are thought to play a large role in reionizing the Universe at redshifts, z > 6. However, due to limited UV data on low-mass galaxies, the models used to estimate the escape of radiation are poorly constrained. Using theoretical models of radiation transport in dusty galaxies with clumpy gas media, we translate measurements of the UV slopes of a sample of low-mass low-z KISSR galaxies to their escape fraction values in Ly-alpha radiation, fesc (LyA), and in the Ly-continuum, fesc (LyC). These low-mass starforming systems have potentially steep UV slopes, and could provide a much-needed relation between easily measured spectral properties such as UV slope or LyA line properties, and the escape of LyA/LyC radiation. Such a relation could advance studies of primordial star clusters and the underlying physical conditions characterizing early galaxies, one of the target observation goals of the soon to-be-launched James Webb Space Telescope. This work was supported by the University of San Francisco Faculty Development Fund, and NSF grant AST-1637339. We thank the Aspen Center for Physics, where some of this work was conducted, and which is supported by National Science Foundation grant PHY-1607611.

KECK SPECTROSCOPY OF FAINT 3 < z < 8 LYMAN BREAK GALAXIES: EVIDENCE FOR A DECLINING FRACTION OF EMISSION LINE SOURCES IN THE REDSHIFT RANGE 6 < z < 8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schenker, Matthew A.; Ellis, Richard S.; Robertson, Brant E.

2012-01-10

Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with the Wide Field Camera 3 on board the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star-forming galaxies with detectable Lyman alpha (Ly{alpha}) emission in the redshift range 6.3 < z < 8.8. Our earlier surveys with the DEIMOS spectrograph demonstrated a significant increase with redshift in the fraction of line emitting galaxies over the interval 4 < z < 6, particularly for intrinsically faint systems which dominate the luminosity density. Using the longer wavelength sensitivities of Lowmore » Resolution Imaging Spectrometer and NIRSPEC, we have targeted 19 Lyman break galaxies selected using recent WFC3/IR data whose photometric redshifts are in the range 6.3 < z < 8.8 and which span a wide range of intrinsic luminosities. Our spectroscopic exposures typically reach a 5{sigma} sensitivity of <50 A for the rest-frame equivalent width (EW) of Ly{alpha} emission. Despite the high fraction of emitters seen only a few hundred million years later, we find only two convincing and one possible line emitter in our more distant sample. Combining with published data on a further seven sources obtained using FORS2 on the ESO Very Large Telescope, and assuming continuity in the trends found at lower redshift, we discuss the significance of this apparent reversal in the redshift-dependent Ly{alpha} fraction in the context of our range in continuum luminosity. Assuming all the targeted sources are at their photometric redshift and our assumptions about the Ly{alpha} EW distribution are correct, we would expect to find so few emitters in less than 1% of the realizations drawn from our lower redshift samples. Our new results provide further support for the suggestion that, at the redshifts now being probed spectroscopically, we are entering the era where the intergalactic medium is partially neutral. With the arrival of more sensitive multi-slit infrared spectrographs, the prospects for improving the statistical validity of this result are promising.« less

Dielectronic satellite spectra of hydrogen-like titanium (Ti XXII)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bitter, M.; von Goeler, S.; Cohen, S.

High resolution spectra of the Ly ..cap alpha../sub 1/ and Ly ..cap alpha../sub 2/ lines of hydrogenlike titanium, TiXXII, and the associated dielectronic satellites which are due to transitions 1snl-2pnl with n greater than or equal to 2, have been observed from tokamak discharges with auxiliary ion cyclotron heating (ICRH) with central electron temperatures of 2 keV and central electron densities of 8 x 10/sup 13/ cm/sup -3/ on the Princeton Large Torus (PLT). The data have been used for a detailed comparison with theoretical predictions based on the Z - expansion method and Hartree - Fock calculations. The resultsmore » obtained with the Z - expansion method are in excellent agreement with the observed spectral data except for minor discrepancies between the theoretical and experimental wavelengths of 0.0003 A for the n = 2 satellites and of 0.0001 A for the separation of the Ly ..cap alpha../sub 1/ and Ly ..cap alpha../sub 2/ lines. Very good agreement with the experimental data is also obtained for the results from the Hartree - Fock calculations though somewhat larger discrepancies (approx. = 0.0009 A) exist between experimental and theoretical wavelengths which are systematically too small. The observed spectra are used for diagnosis of the central ion and electron temperatures of the PLT discharges and for a measurement of the dielectronic recombination rate coefficient of TiXXII.« less

Do Lyman-alpha photons escape from star-forming galaxies through dust holes?

NASA Astrophysics Data System (ADS)

France, Kevin; Wofford, A.; Leitherer, C.; Fleming, B.; McCandliss, S. R.; Nell, N.

2014-01-01

H I Lyman-alpha (LyA) is commonly used as a signpost for the entire galaxy at redshifts z>2, and yet spatially and kinematically resolved views of the local conditions within galaxies that determine the integrated properties of this line are scarce. We obtained Hubble Space Telescope (HST) images in continuum-subtracted LyA, H-alpha, H-beta, and far-UV continuum of three low-inclination spiral star-forming galaxies located at redshifts z=0.02, 0.03, and 0.05. This was accomplished using the UVIS and SBC channels of the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS), respectively. Previous HST spectroscopy obtained by our team with the Cosmic Origins Spectrograph (COS) showed that the galaxies display different integrated LyA profiles within their central few kiloparsecs, i.e., pure absorption, single emission, and double emission, which are representative of what is observed between redshifts 0-3. This data is useful for establishing the relative importance of starburst phase, dust content, and gas kinematics in determining the LyA escape. We present preliminary results that combine our spectroscopic and imaging observations.

Evidence for a temperature rise in the outer layers of alpha Lyrae, from Copernicus observations of Lyman-alpha

NASA Technical Reports Server (NTRS)

Praderie, F.; Simonneau, E.; Snow, T. P., Jr.

1975-01-01

Copernicus satellite observations of the Ly-alpha profiles in alpha Lyrae (Vega) are used to determine whether classical radiative-equilibrium LTE model atmospheres can fit the thermal structure in the outer layers of that star. Two plane-parallel LTE model photospheres of alpha Lyrae are considered: a line-blanketed radiative-equilibrium model with an effective temperature of 9650 K and log g of 4.05, and the same model with a temperature of 9500 K and log g of 4.0. The profiles of the Ly-alpha wings are computed, and it is found that classical LTE models are unable to predict either the observed violet wing or the red wing longwards of 1239 A, regardless of the line source function. It is concluded that the electron temperature must increase outwards over the surface value reached in radiative equilibrium.

Studies of H I and D I in the local interstellar medium

NASA Technical Reports Server (NTRS)

Murthy, J.; Henry, R. C.; Moos, H. W.; Vidal-Madjar, A.; Linsky, J. L.

1990-01-01

High-dispersion IUE spectra are presented of the hydrogen Ly-alpha chromospheric emission line of two nearby late-type stars, Capella and Lambda And. Both interstellar H I and D I Ly-alpha absorption can be seen against the chromospheric line, and the density, velocity dispersion, and bulk velocity of the gas in those lines of sight are derived. Limits are placed on the D/H ratio. The results are consistent with the current picture of the local interstellar medium.

The SDSS-DR12 large-scale cross-correlation of damped Lyman alpha systems with the Lyman alpha forest

NASA Astrophysics Data System (ADS)

Pérez-Ràfols, Ignasi; Font-Ribera, Andreu; Miralda-Escudé, Jordi; Blomqvist, Michael; Bird, Simeon; Busca, Nicolás; du Mas des Bourboux, Hélion; Mas-Ribas, Lluís; Noterdaeme, Pasquier; Petitjean, Patrick; Rich, James; Schneider, Donald P.

2018-01-01

We present a measurement of the damped Ly α absorber (DLA) mean bias from the cross-correlation of DLAs and the Ly α forest, updating earlier results of Font-Ribera et al. (2012) with the final Baryon Oscillations Spectroscopic Survey data release and an improved method to address continuum fitting corrections. Our cross-correlation is well fitted by linear theory with the standard ΛCDM model, with a DLA bias of bDLA = 1.99 ± 0.11; a more conservative analysis, which removes DLA in the Ly β forest and uses only the cross-correlation at r > 10 h-1 Mpc, yields bDLA = 2.00 ± 0.19. This assumes the cosmological model from Planck Collaboration (2016) and the Ly α forest bias factors of Bautista et al. (2017) and includes only statistical errors obtained from bootstrap analysis. The main systematic errors arise from possible impurities and selection effects in the DLA catalogue and from uncertainties in the determination of the Ly α forest bias factors and a correction for effects of high column density absorbers. We find no dependence of the DLA bias on column density or redshift. The measured bias value corresponds to a host halo mass ∼4 × 1011 h-1 M⊙ if all DLAs were hosted in haloes of a similar mass. In a realistic model where host haloes over a broad mass range have a DLA cross-section Σ (M_h) ∝ M_h^{α } down to Mh > Mmin = 108.5 h-1 M⊙, we find that α > 1 is required to have bDLA > 1.7, implying a steeper relation or higher value of Mmin than is generally predicted in numerical simulations of galaxy formation.

Reprocessing of Soft X-ray Emission Lines in Black Hole Accretion Disks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauche, C W; Liedahl, D A; Mathiesen, B F

By means of a Monte Carlo code that accounts for Compton scattering and photoabsorption followed by recombination, we have investigated the radiation transfer of Ly{alpha}, He{alpha}, and recombination continua photons of H- and He-like C, N, O, and Ne produced in the photoionized atmosphere of a relativistic black hole accretion disk. We find that photoelectric opacity causes significant attenuation of photons with energies above the O VIII K-edge; that the conversion efficiencies of these photons into lower-energy lines and recombination continua are high; and that accounting for this reprocessing significantly (by factors of 21% to 105%) increases the flux ofmore » the Ly{alpha} and He{alpha} emission lines of H- and He-like C and O escaping the disk atmosphere.« less

NEUTRAL HYDROGEN OPTICAL DEPTH NEAR STAR-FORMING GALAXIES AT z Almost-Equal-To 2.4 IN THE KECK BARYONIC STRUCTURE SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rakic, Olivera; Schaye, Joop; Steidel, Charles C.

We study the interface between galaxies and the intergalactic medium by measuring the absorption by neutral hydrogen in the vicinity of star-forming galaxies at z Almost-Equal-To 2.4. Our sample consists of 679 rest-frame UV-selected galaxies with spectroscopic redshifts that have impact parameters <2 (proper) Mpc to the line of sight of one of the 15 bright, background QSOs and that fall within the redshift range of its Ly{alpha} forest. We present the first two-dimensional maps of the absorption around galaxies, plotting the median Ly{alpha} pixel optical depth as a function of transverse and line-of-sight separation from galaxies. The Ly{alpha} opticalmore » depths are measured using an automatic algorithm that takes advantage of all available Lyman series lines. The median optical depth, and hence the median density of atomic hydrogen, drops by more than an order of magnitude around 100 kpc, which is similar to the virial radius of the halos thought to host the galaxies. The median remains enhanced, at the >3{sigma} level, out to at least 2.8 Mpc (i.e., >9 comoving Mpc), but the scatter at a given distance is large compared with the median excess optical depth, suggesting that the gas is clumpy. Within 100 (200) kpc, and over {+-}165 km s{sup -1}, the covering fraction of gas with Ly{alpha} optical depth greater than unity is 100{sup +0}{sub -32}% (66% {+-} 16%). Absorbers with {tau}{sub Ly{alpha}} > 0.1 are typically closer to galaxies than random. The mean galaxy overdensity around absorbers increases with the optical depth and also as the length scale over which the galaxy overdensity is evaluated is decreased. Absorbers with {tau}{sub Ly{alpha}} {approx} 1 reside in regions where the galaxy number density is close to the cosmic mean on scales {>=}0.25 Mpc. We clearly detect two types of redshift space anisotropies. On scales <200 km s{sup -1}, or <1 Mpc, the absorption is stronger along the line of sight than in the transverse direction. This 'finger of God' effect may be due to redshift errors, but is probably dominated by gas motions within or very close to the halos. On the other hand, on scales of 1.4-2.0 Mpc the absorption is compressed along the line of sight (with >3{sigma} significance), an effect that we attribute to large-scale infall (i.e., the Kaiser effect).« less

An Empirical Model of the Variations of the Solar Lyman-Alpha Spectral Irradiance

NASA Astrophysics Data System (ADS)

Kretzschmar, M.; Snow, M. A.; Curdt, W.

2017-12-01

We propose a simple model that computes the spectral profile of the solar irradiance in the Hydrogen Lyman alpha line, H Ly-α (121.567nm), from 1947 to present. Such a model is relevant for the study of many astronomical environments, from planetary atmospheres to interplanetary medium, and can be used to improve the analysis of data from mission like MAVEN or GOES-16. This empirical model is based on the SOHO/SUMER observations of the Ly-α irradiance over solar cycle 23, which we analyze in details, and relies on the Ly-α integrated irradiance composite. The model reproduces the temporal variability of the spectral profile and matches the independent SORCE/SOSLTICE spectral observations from 2003 to 2007 with an accuracy better than 10%.

A New Survey for Low-Redshift Damped Lyman-Alpha Lines in QSO MgII Systems

NASA Astrophysics Data System (ADS)

Rao, Sandhya

2000-07-01

Studies have shown that most of the observable neutral gas mass in the Universe resides in QSO damped LyAlpha {DLA} systems. However, at low redshift {z<1.65}, DLA can only be found by searching in the UV with HST. Such searches are crucial since z<1.65 corresponds to 3/4 of the age of the Universe. The identification of significant numbers of low- redshift DLA systems is imperative if we ever hope to effectively study this cosmologically massive component of neutral gas. To this end, we recently reported on the results of our initial HST survey to study low-redshift DLA absorbers in QSO MgII systems. We discovered 14 DLA systems and had a success rate of 14%. Now, based on these results and our improved understanding of the selection criteria for successful DLA searches, we propose a new survey for low-redshift DLA lines in QSO MgII systems. With our new revised selection criteria, we can empirically show that our success rate would be 35%. Specifically, we propose to observe the LyAlpha line of 55 MgII systems. We estimate that we will discover 19 new DLA systems with redshift z<1.65. Finding these systems will facilitate the type of research that can be done with DLA systems. By boot-strapping from the MgII statistics, we will be able to further improve the determination of the low- redshift statistical properties of DLA {their incidence and cosmological mass density} and open up new opportunities for studies at low redshift.

Type I interferon regulates pDC maturation and Ly49Q expression.

PubMed

Toma-Hirano, Makiko; Namiki, Sahori; Miyatake, Shoichiro; Arai, Ken-Ichi; Kamogawa-Schifter, Yumiko

2007-10-01

Ly49Q is expressed on peripheral mouse plasmacytoid dendritic cells (pDC). Immature Ly49Q-negative pDC precursors acquire Ly49Q in the bone marrow and then migrate into the periphery. While searching for molecules that regulate pDC maturation, we found that type I interferon (IFN) inhibited Ly49Q acquisition in vitro. Infections that induce type I IFN production by cells other than pDC (a condition mimicked by poly(I:C) injection in vivo) increase the prevalence of Ly49Q(-) pDC in the bone marrow and peripheral lymphoid organs in wild-type but not IFN-alpha/beta receptor knockout BALB/c mice. Moreover, in vivo exposure to type I IFN causes some Ly49Q(-), but not Ly49Q(+), pDC to convert to conventional DC, defined as B220(-) CD11c(+) CD11b(+) cells. These data suggest that type I IFN regulates pDC development and affects their distribution in the body.

First Results from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) Survey: Cosmological Reionization at z ˜ 7

NASA Astrophysics Data System (ADS)

Zheng, Zhen-Ya; Wang, Junxian; Rhoads, James; Infante, Leopoldo; Malhotra, Sangeeta; Hu, Weida; Walker, Alistair R.; Jiang, Linhua; Jiang, Chunyan; Hibon, Pascale; Gonzalez, Alicia; Kong, Xu; Zheng, XianZhong; Galaz, Gaspar; Barrientos, L. Felipe

2017-06-01

We present the first results from the ongoing Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) project, which is the largest narrowband survey for z ˜ 7 galaxies to date. Using a specially built narrowband filter NB964 for the superb large-area Dark Energy Camera (DECam) on the NOAO/CTIO 4 m Blanco telescope, LAGER has collected 34 hr NB964 narrowband imaging data in the 3 deg2 COSMOS field. We have identified 23 Lyα Emitter candidates at z = 6.9 in the central 2-deg2 region, where DECam and public COSMOS multi-band images exist. The resulting luminosity function (LF) can be described as a Schechter function modified by a significant excess at the bright end (four galaxies with L Lyα ˜ 1043.4±0.2 erg s-1). The number density at L Lyα ˜ 1043.4±0.2 erg s-1 is little changed from z = 6.6, while at fainter L Lyα it is substantially reduced. Overall, we see a fourfold reduction in Lyα luminosity density from z = 5.7 to z = 6.9. Combined with a more modest evolution of the continuum UV luminosity density, this suggests a factor of ˜3 suppression of Lyα by radiative transfer through the z ˜ 7 intergalactic medium (IGM). It indicates an IGM neutral fraction of x H I ˜ 0.4-0.6 (assuming Lyα velocity offsets of 100-200 km s-1). The changing shape of the Lyα LF between z ≲ 6.6 and z = 6.9 supports the hypothesis of ionized bubbles in a patchy reionization at z ˜ 7.

Hydrodynamic Simulations and Tomographic Reconstructions of the Intergalactic Medium

NASA Astrophysics Data System (ADS)

Stark, Casey William

The Intergalactic Medium (IGM) is the dominant reservoir of matter in the Universe from which the cosmic web and galaxies form. The structure and physical state of the IGM provides insight into the cosmological model of the Universe, the origin and timeline of the reionization of the Universe, as well as being an essential ingredient in our understanding of galaxy formation and evolution. Our primary handle on this information is a signal known as the Lyman-alpha forest (or Ly-alpha forest) -- the collection of absorption features in high-redshift sources due to intervening neutral hydrogen, which scatters HI Ly-alpha photons out of the line of sight. The Ly-alpha forest flux traces density fluctuations at high redshift and at moderate overdensities, making it an excellent tool for mapping large-scale structure and constraining cosmological parameters. Although the computational methodology for simulating the Ly-alpha forest has existed for over a decade, we are just now approaching the scale of computing power required to simultaneously capture large cosmological scales and the scales of the smallest absorption systems. My thesis focuses on using simulations at the edge of modern computing to produce precise predictions of the statistics of the Ly-alpha forest and to better understand the structure of the IGM. In the first part of my thesis, I review the state of hydrodynamic simulations of the IGM, including pitfalls of the existing under-resolved simulations. Our group developed a new cosmological hydrodynamics code to tackle the computational challenge, and I developed a distributed analysis framework to compute flux statistics from our simulations. I present flux statistics derived from a suite of our large hydrodynamic simulations and demonstrate convergence to the per cent level. I also compare flux statistics derived from simulations using different discretizations and hydrodynamic schemes (Eulerian finite volume vs. smoothed particle hydrodynamics) and discuss differences in their convergence behavior, their overall agreement, and the implications for cosmological constraints. In the second part of my thesis, I present a tomographic reconstruction method that allows us to make 3D maps of the IGM with Mpc resolution. In order to make reconstructions of large surveys computationally feasible, I developed a new Wiener Filter application with an algorithm specialized to our problem, which significantly reduces the space and time complexity compared to previous implementations. I explore two scientific applications of the maps: finding protoclusters by searching the maps for large, contiguous regions of low flux and finding cosmic voids by searching the maps for regions of high flux. Using a large N-body simulation, I identify and characterize both protoclusters and voids at z = 2.5, in the middle of the redshift range being mapped by ongoing surveys. I provide simple methods for identifying protocluster and void candidates in the tomographic flux maps, and then test them on mock surveys and reconstructions. I present forecasts for sample purity and completeness and other scientific applications of these large, high-redshift objects.

Si III OV Bright Line of Scattering Polarized Light That Has Been Observed in the CLASP and Its Center-to-Limb Variation

NASA Technical Reports Server (NTRS)

Katsukawa, Yukio; Ishikawa, Ryoko; Kano, Ryohei; Kubo, Masahito; Noriyuki, Narukage; Kisei, Bando; Hara, Hirohisa; Yoshiho, Suematsu; Goto, Motouji; Ishikawa, Shinnosuke;

Measuring electron temperature in the extended corona

NASA Technical Reports Server (NTRS)

Hassler, Donald M.; Gardner, L. D.; Kohl, John L.

1992-01-01

A technique for measuring electron temperature in the extended corona from the line profile of the electron scattered component of coronal H I Ly alpha produced by Thomson scattering of chromospheric Ly alpha emission is discussed. Because of the high thermal velocity of electrons at coronal temperatures (approximately 6800 km/s at T(sub e) = 1,500,000 K) the effect of nonthermal velocities and solar wind flows on the electron velocity distribution are negligible. However, the low electron mass which is responsible for the high thermal velocity also results in a very wide profile (approximately equal to 50 A). This wide profile, together with an intensity that is three orders of magnitude weaker than the resonantly scattered component of Ly alpha makes the direct measurement of T(sub e) a challenging observational problem. An evaluation of this technique based on simulated measurements is presented and the subsequent instrumental requirements necessary to make a meaningful determination of the electron temperature are discussed. Estimates of uncertainties in the measured electron temperature are related to critical instrument parameters such as grating stray light suppression.

Imaging of the Field of 4C41.17 Below the Lyman Limit

NASA Technical Reports Server (NTRS)

Lacy, Mark; Rawlings, Steve

1997-01-01

Imaging of zeta greater than or equal to 3.4 radio galaxy fields below the Lyman continuum wavelength allows companion galaxies to be identified on the basis of red colors across the wavelength of redshifted Ly(alpha) and very red colors across the redshifted Lyman continuum. These arise due to a combination of absorption by intervening Ly(alpha) forest and Lyman-limit systems, and intrinsic Lyman-limit breaks in the galaxy spectral energy distribution caused by an Hi screen or breaks in stellar spectra. As a pilot study, we have imaged the field of the zeta = 3.8 radio galaxy 4C41.17 in U, V and R with the Auxiliary Port of the WHT. We find a number of potential companion galaxies, which require confirmation via spectroscopy or narrow-band imaging. The Lyman-limit in the spectrum of the radio galaxy itself and its implications for the origin of the UV flux is also discussed.

Coronagraph observations and analyses of the ultraviolet solar corona

NASA Technical Reports Server (NTRS)

Kohl, John L.

1989-01-01

The major activities on the Spartan Ultraviolet Coronal Spectrometer project include both scientific and experimental/technical efforts. In the scientific area, a detailed analysis of the previously reported Doppler dimming of HI Ly-alpha from the July 1982 rocket flight has determined an outflow velocity at 2 solar radii from sun center to be between 153 and 251 km/s at 67 percent confidence. The technical activities include, several improvements made to the instrument that will result in enhanced scientific performance or in regaining a capability that had deteriorated during the delay time in the launch date. These include testing and characterizing the detector for OVI radiation, characterizing a serrated occulter at UV and visible wavelengths, fabricating and testing telescope mirrors with improved edges, testing and evaluating a new array detector system, modifying the slit mask mechanism and installing a mask in the instrument to block the Ly-alpha resonance line when the electron scattered component is being observed.

THE LYMAN ALPHA REFERENCE SAMPLE. V. THE IMPACT OF NEUTRAL ISM KINEMATICS AND GEOMETRY ON Lyα ESCAPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivera-Thorsen, Thøger E.; Hayes, Matthew; Östlin, Göran

2015-05-20

We present high-resolution far-UV spectroscopy of the 14 galaxies of the Lyα Reference Sample; a sample of strongly star-forming galaxies at low redshifts (0.028 < z < 0.18). We compare the derived properties to global properties derived from multi-band imaging and 21 cm H i interferometry and single-dish observations, as well as archival optical SDSS spectra. Besides the Lyα line, the spectra contain a number of metal absorption features allowing us to probe the kinematics of the neutral ISM and evaluate the optical depth and and covering fraction of the neutral medium as a function of line of sight velocity.more » Furthermore, we show how this, in combination with the precise determination of systemic velocity and good Lyα spectra, can be used to distinguish a model in which separate clumps together fully cover the background source, from the “picket fence” model named by Heckman et al. We find that no one single effect dominates in governing Lyα radiative transfer and escape. Lyα escape in our sample coincides with a maximum velocity-binned covering fraction of ≲0.9 and bulk outflow velocities of ≳50 km s{sup −1}, although a number of galaxies show these characteristics and yet little or no Lyα escape. We find that Lyα peak velocities, where available, are not consistent with a strong backscattered component, but rather with a simpler model of an intrinsic emission line overlaid by a blueshifted absorption profile from the outflowing wind. Finally, we find a strong anticorrelation between Hα equivalent width and maximum velocity-binned covering factor, and propose a heuristic explanatory model.« less

The Universe Is Reionizing at z ∼ 7: Bayesian Inference of the IGM Neutral Fraction Using Lyα Emission from Galaxies

NASA Astrophysics Data System (ADS)

Mason, Charlotte A.; Treu, Tommaso; Dijkstra, Mark; Mesinger, Andrei; Trenti, Michele; Pentericci, Laura; de Barros, Stephane; Vanzella, Eros

2018-03-01

We present a new flexible Bayesian framework for directly inferring the fraction of neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR, z ∼ 6–10) from detections and non-detections of Lyman Alpha (Lyα) emission from Lyman Break galaxies (LBGs). Our framework combines sophisticated reionization simulations with empirical models of the interstellar medium (ISM) radiative transfer effects on Lyα. We assert that the Lyα line profile emerging from the ISM has an important impact on the resulting transmission of photons through the IGM, and that these line profiles depend on galaxy properties. We model this effect by considering the peak velocity offset of Lyα lines from host galaxies’ systemic redshifts, which are empirically correlated with UV luminosity and redshift (or halo mass at fixed redshift). We use our framework on the sample of LBGs presented in Pentericci et al. and infer a global neutral fraction at z ∼ 7 of {\\overline{x}}{{H}{{I}}}={0.59}-0.15+0.11, consistent with other robust probes of the EoR and confirming that reionization is ongoing ∼700 Myr after the Big Bang. We show that using the full distribution of Lyα equivalent width detections and upper limits from LBGs places tighter constraints on the evolving IGM than the standard Lyα emitter fraction, and that larger samples are within reach of deep spectroscopic surveys of gravitationally lensed fields and James Webb Space Telescope NIRSpec.

First Results from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) Survey: Cosmological Reionization at z ∼ 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Zhen-Ya; Jiang, Chunyan; Wang, Junxian

2017-06-20

We present the first results from the ongoing Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) project, which is the largest narrowband survey for z ∼ 7 galaxies to date. Using a specially built narrowband filter NB964 for the superb large-area Dark Energy Camera (DECam) on the NOAO/CTIO 4 m Blanco telescope, LAGER has collected 34 hr NB964 narrowband imaging data in the 3 deg{sup 2} COSMOS field. We have identified 23 Ly α Emitter candidates at z = 6.9 in the central 2-deg{sup 2} region, where DECam and public COSMOS multi-band images exist. The resulting luminosity function (LF)more » can be described as a Schechter function modified by a significant excess at the bright end (four galaxies with L {sub Lyα∼} 10{sup 43.4±0.2} erg s{sup −1}). The number density at L {sub Ly} {sub α} ∼ 10{sup 43.4±0.2} erg s{sup −1} is little changed from z = 6.6, while at fainter L {sub Lyα} it is substantially reduced. Overall, we see a fourfold reduction in Ly α luminosity density from z = 5.7 to z = 6.9. Combined with a more modest evolution of the continuum UV luminosity density, this suggests a factor of ∼3 suppression of Ly α by radiative transfer through the z ∼ 7 intergalactic medium (IGM). It indicates an IGM neutral fraction of x {sub Hi} ∼ 0.4–0.6 (assuming Ly α velocity offsets of 100–200 km s{sup −1}). The changing shape of the Ly α LF between z ≲ 6.6 and z = 6.9 supports the hypothesis of ionized bubbles in a patchy reionization at z ∼ 7.« less

Cosmic Metal Production and the Contribution of QSO Absorption Systems to the Ionizing Background

NASA Technical Reports Server (NTRS)

Madau, Piero; Shull, J. Michael

1996-01-01

The recent discovery by Cowie et al. (1995) and Tytler et al. (1995) of metals in the Ly alpha clouds shows that the intergalactic medium (IGM) at high redshift is contaminated by the products of stars and suggests that ionizing photons from massive star formation may be a significant contributor to the UV background radiation at early epochs. We assess the validity of the stellar photoionization hypothesis. Based on recent computations of metal yields and 0-star Lyman continuum (Lyc) fluxes, we find that 0.2 percent of the rest-mass energy of the metals produced is radiated as Lyc. By modeling the transfer of ionizing radiation through the IGM and the rate of chemical enrichment, we demonstrate that the background intensity of photons at 1 ryd that accompanies the production of metals in the Ly alpha forest clouds may be significant, approaching 0.5 x 10(exp -21) ergs cm squared s(-1) Hz(-1) sr(-1) at z approximately equals 3 if the Lyc escape fraction is greater than of equal to 0.25. Together with quasars, massive stars could then, in principle, provide the hydrogen and helium Lyc photons required to ionize the universe at high redshifts. We propose that observations of the He2 Gunn-Peterson effect and of the metal ionization states of the Ly alpha forest and Lyman-limit absorbers should show the signature of a stellar spectrum. We also note that the stellar photoionization model fails if a large fraction of the UV radiation emitted from stars cannot escape into the IGM, as suggested by the recent Hopkins Ultraviolet Telescope observations by Leitherer et al. (1995) of low-redshift starburst galaxies, or if most of the metals observed at z is approximately 3 were produced at much earlier epochs.

The Characteristic Dimension of Lyman-Alpha Forest Clouds Toward Q0957+561

NASA Technical Reports Server (NTRS)

Dolan, J. F.; Michalitsianos, A. G.; Hill, R. J.; Nguyen, Q. T.; Fisher, Richard (Technical Monitor)

2000-01-01

Far-ultraviolet spectra of the gravitational lens components Q0957+561 A and B were obtained with the Hubble Space Telescope Faint Object Spectrograph to investigate the characteristic dimension of Lyman-alpha forest clouds in the direction of the quasar. If one makes the usual assumption that the absorbing structures are spherical clouds with a single radius, that radius can be found analytically from the ratio of Lyman-alpha lines in only one line of sight to the number in both. A simple power series approximation to this solution, accurate everywhere to better than 1%, will be presented. Absorption lines in Q0957+561 having equivalent width greater than 0.3 A in the observer's frame not previously identified as interstellar lines, metal lines, or higher order Lyman lines were taken to be Ly-alpha forest lines. The existence of each line in this consistently selected set was then verified by its presence in two archival FOS spectra with approximately 1.5 times higher signal to noise than our spectra. Ly-alpha forest lines appear at 41 distinct wavelengths in the spectra of the two images. One absorption line in the spectrum of image A has no counterpart in the spectrum of image B, and one line in image B has no counterpart in image A. Based on the separation of the lines of sight over the redshift range searched for Ly-alpha forest lines, the density of the absorbing clouds in the direction of Q0957+561 must change significantly over a radius R = 160 (+120, -70) h (sup -1) (sub 50) kpc (H (sub 0) 50 h (sub 50) km s (sup -1) kpc (sup -1), q (sub 0) = 1/2). The 95% confidence interval on R extends from (50 950) h (sup -1) (sub 50) kpc.

The missing UV absorption lines of NGC 4151

NASA Technical Reports Server (NTRS)

Leech, K. J.; Penston, M. V.; Snijders, M. A. J.; Ward, M. J.; Gull, T. R.

1990-01-01

Near simultaneous high dispersion long and short wavelength International Ultraviolet Explorer (IUE) observations of the Seyfert galaxy NGC 4151 are discussed. Previous observations revealed a narrow absorption system in Mg II not present in Ly alpha or C IV. The new observations confirm the presence of this system in Mg II and its absence in the other lines. Possible reasons for this are discussed. Future Hubble Space Telescope studies of NGC 4151 are discussed.

LY3127760, a Selective Prostaglandin E4 (EP4) Receptor Antagonist, and Celecoxib: A Comparison of Pharmacological Profiles

PubMed Central

Smith, Claire; Hu, Leijun; Coutant, David E.; Whitehurst, Kelly; Phipps, Krista; McNearney, Terry Ann; Yang, Xiao; Ackermann, Bradley; Pottanat, Thomas; Landschulz, William

2017-01-01

Abstract Safety, tolerability, and pharmacology profiles of LY3127760, an EP4 antagonist, were explored in healthy subjects in a subject/investigator‐blind, parallel‐group, multiple‐ascending dose study. Cohorts consisted of 13 patients randomized to LY3127760, celecoxib (400 mg), or placebo (9:2:2 ratio) for 28 days. LY3127760 was well tolerated; the most commonly observed adverse events were gastrointestinal, similar to celecoxib. LY3127760 increased release of ex vivo tumor necrosis factor alpha after lipopolysaccharide/prostaglandin E2 stimulation when compared with placebo, suggesting a dose‐dependent blockade of the EP4 receptor. Compared with placebo, 24‐h urinary excretion of prostaglandin E metabolite was modestly increased; prostacyclin metabolite was inhibited; and thromboxane A2 metabolite was unchanged. Effects on sodium and potassium excretion were similar to those of celecoxib. We conclude that LY3127760 demonstrated similar effects on prostacyclin synthesis and renal sodium retention as celecoxib. These data support exploration of LY3127760 at daily doses of 60 mg to 600 mg in phase II trials. This trial's registration number: NCT01968070. PMID:28857461

Effects of ionotropic glutamate receptor antagonists on rat dural artery diameter in an intravital microscopy model.

PubMed

Chan, K Y; Gupta, S; de Vries, R; Danser, A H J; Villalón, C M; Muñoz-Islas, E; Maassenvandenbrink, A

2010-07-01

During migraine, trigeminal nerves may release calcitonin gene-related peptide (CGRP), inducing cranial vasodilatation and central nociception; hence, trigeminal inhibition or blockade of craniovascular CGRP receptors may prevent this vasodilatation and abort migraine headache. Several preclinical studies have shown that glutamate receptor antagonists affect the pathophysiology of migraine. This study investigated whether antagonists of NMDA (ketamine and MK801), AMPA (GYKI52466) and kainate (LY466195) glutamate receptors affected dural vasodilatation induced by alpha-CGRP, capsaicin and periarterial electrical stimulation in rats, using intravital microscopy. Male Sprague-Dawley rats were anaesthetized and the overlying bone was thinned to visualize the dural artery. Then, vasodilator responses to exogenous (i.v. alpha-CGRP) and endogenous (released by i.v. capsaicin and periarterial electrical stimulation) CGRP were elicited in the absence or presence of the above antagonists. alpha-CGRP, capsaicin and periarterial electrical stimulation increased dural artery diameter. Ketamine and MK801 inhibited the vasodilator responses to capsaicin and electrical stimulation, while only ketamine attenuated those to alpha-CGRP. In contrast, GYKI52466 only attenuated the vasodilatation to exogenous alpha-CGRP, while LY466195 did not affect the vasodilator responses to endogenous or exogenous CGRP. Although GYKI52466 has not been tested clinically, our data suggest that it would not inhibit migraine via vascular mechanisms. Similarly, the antimigraine efficacy of LY466195 seems unrelated to vascular CGRP-mediated pathways and/or receptors. In contrast, the cranial vascular effects of ketamine and MK801 may represent a therapeutic mechanism, although the same mechanism might contribute, peripherally, to cardiovascular side effects.

Analysis of time-resolved argon line spectra from OMEGA direct-drive implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Florido, R.; Nagayama, T.; Mancini, R. C.

2008-10-15

We discuss the observation and data analysis of argon K-shell line spectra from argon-doped deuterium-filled OMEGA direct-drive implosion cores based on data recorded with two streaked crystal spectrometers. The targets were 870 {mu}m in diameter, 27 {mu}m wall thickness plastic shells filled with 20 atm of deuterium gas, and a tracer amount of argon for diagnostic purposes. The argon K-shell line spectrum is primarily emitted at the collapse of the implosion and its analysis provides a spectroscopic diagnostic of the core implosion conditions. The observed spectra includes the He{alpha}, Ly{alpha}, He{beta}, He{gamma}, Ly{beta}, and Ly{gamma} line emissions and their associatedmore » He- and Li-like satellites thus covering a broad photon energy range from 3100 to 4200 eV with a spectral resolution power of approximately 500. The data analysis relies on detailed atomic and spectral models that take into account nonequilibrium collisional-radiative atomic kinetics, Stark-broadened line shapes, and radiation transport calculations.« less

The z = 0.8596 damped Ly-alpha absorbing galaxy toward PKS 0454+039

NASA Technical Reports Server (NTRS)

Steidel, Charles C.; Bowen, David V.; Blades, J. Chris; Dickenson, Mark

1995-01-01

We present Hubble Space Telescope (HST) and ground-based data on the Z(sub abs) = 0.8596 metal-line absorption system along the line of sight to PKS 0454+0356. The system is a moderate-redshift damped Ly-alpha system, with N(H I) = (5.7 +/- 0.3) x 10(exp 20)/sq cm as measured from the Faint Object Spectrograph (FOS) spectrum. We also present ground-based images which we use to identify the galaxy which most probably gives rise to the damped system; the most likely candidate is relatively underluminous by QSO absorber standards M(sub B) approximately -19.0 for A(sub 0) = 0.5 and H(sub 0) = 50 km/s/Mpc) and lies approximately 8.5/h kpc in projection from the QSO sight line. Ground-based measurements of Zn II, Cr II, and Fe II absorption lines from this system allow us to infer abundances of (Zn/H) = -1.1, (Cr/H) = -1.2, and (Fe/H) = -1.2 indicating overall metallicity similar to damped systems at z is greater than 2, and that the depletion of Cr and Fe onto dust grains may be even less important than in many of the high-redshift systems of comparable metallicity. Limits previously placed on the 21 cm optical depth in the z = 0.8596 system, together with our new N(H I) measurement, suggest a very high spin temperature for the H I, T(sub s) is greater than 580 K.

Intergalactic Helium Absorption toward High-Redshift Quasars

NASA Technical Reports Server (NTRS)

Giroux, Mark L.; Fardal, Mark A.; Shull, J. Michael

1995-01-01

The recent Hubble Space Telescope (HST) observations of the z(q) = 3.286 quasar Q0302-003 (Jakobsen et at. 1994) and the z(q) = 3.185 quasar Q1935-67 by Tytler (1995) show absorption edges at the redshifted wavelength of He II 304 A. A key goal is to distinguish between contributions from discrete Ly-alpha forest clouds and a smoothly distributed intergalactic medium (IGM). We model the contributions from each of these sources of He II absorption, including the distribution of line Doppler widths and column densities, the 'He II proximity effect' from the quasar, and a self-consistent derivation of the He II opacity of the universe as a function of the spectrum of ionizing sources, with the assumption that both the clouds and the IGM are photoionized. The He II edge can be fully accounted for by He II line blanketing for reasonable distributions of line widths and column densities in the Ly-alpha forest, provided that the ionizing sources have spectral index alpha(s) greater than 1.5, and any He II proximity effect is neglected. Even with some contribution from a diffuse IGM, it is difficult to account for the edge observed by Jakobsen et al. (1994) with a 'hard' source spectrum (alpha(s) less than 1.3). The proximity effect modifies the relative contributions of the clouds and IGM to tau(He II) near the quasar (z approx. less than z(q)) and markedly increases the amount of He II absorption required. This implies, for example, that to account for the He II edge with line blanketing alone, the minimum spectral index alpha(s) must be increased from 1.5 to 1.9. We demonstrate the need for higher resolution observations that characterize the change in transmission as z approaches z(q) and resolve line-free gaps in the continuum. We set limits on the density of the diffuse IGM and suggest that the IGM and Ly-alpha clouds are likely to be a significant repository for dark baryons.

The Lyman-Alpha Forest in the Lensed Quasar Q0957+561 and the Characteristic Dimension of the Absorbing Clouds

NASA Technical Reports Server (NTRS)

Dolan, Joseph; Fisher, Richard R. (Technical Monitor)

2001-01-01

Far-ultraviolet spectra of the gravitational lens components Q0957+561 A and 9 were obtained with the Hubble Space Telescope Faint Object Spectrograph (FOS) at five equally spaced epochs, one every two weeks. We confirm the flux variability of the quasar's Lyman-alpha and 0 VI emission lines reported by Dolan et al. (1995) in IUE spectra. The fluxes in these lines vary on a time scale of weeks in the observer's rest frame, independently of each other and of the surrounding continuum. The individual spectra of each image were co-added to investigate the properties of the Lyman-alpha forest along the two lines of sight to the quasar. Absorption lines having equivalent width W > 0.3 A in the observer's frame not previously identified by Michalitsianos et al. (1997) as interstellar lines, metal lines, or higher order Lyman lines were taken to be Ly-alpha forest lines. The existence of each line in this consistently selected set was then verified by its presence in two archival FOS spectra with -1.5 times higher signal to noise than our co-added spectra. Ly-alpha forest lines with W > 0.3 A appear at 41 distinct wavelengths in the spectra of the two images. one absorption line in the spectrum of image A has no counterpart in the spectrum of image B and one line in image B has no counterpart in image A. Based on the separation of the lines of sight over the redshift range searched for Ly-forest lines, the density of the absorbing clouds in the direction of Q0957+561 must change significantly over a distance R = 160 (+120, -70)/ h(sub 50) kpc in the simplified model where the absorbers are treated as spherical clouds and the characteristic dimension, R, is the radius. (We adopt H(sub 0) = 50 h(sub 50) km/s/ kpc, q(sub 0) = 1/2, and lambda = 0 throughout the paper.) The 95% confidence interval on R extends from (50 - 950)/h(sub 50) kpc We show in the Appendix that the fraction of Ly-alpha forest lines that appear in only one spectrum can be expressed as a rapidly converging power series in 1/r, where r the ratio of the radius of the cloud to the separation of the two lines of sight at the redshift of the cloud. This power series can be rewritten to give r in terms of the fraction of Ly-forest wavelengths that appear in the spectrum of only one image. A simple linear approximation to the solution that everywhere agrees with the power series solution to better than 0.8% for r > 2 is derived in the Appendix.

Deuterium and the Local Interstellar Medium: Properties for the Procyon and Capella Lines of Sight

NASA Technical Reports Server (NTRS)

Linsky, Jeffrey L.; Diplas, Athanassios; Wood, Brian E.; Brown, Alexander; Ayres, Thomas R.; Savage, Blair D.

1995-01-01

We present Goddard High-Resolution Spectrograph observations of the interstellar H I and D I Ly-alpha lines and the Mg II and Fe II resonance lines formed along the lines of sight toward the nearby stars Procyon (3.5 pc, l = 214 deg, b = 13 deg) and Capella (12.5 pc, l = 163 deg, b = 5 deg). New observations of Capella were obtained at orbital phase 0.80, when the radial velocities of the intrinsic Ly-alpha emission lines of each star were nearly reversed from those of the previous observations at phase 0.26. Since the intrinsic Ly-alpha line of the Capella system (the 'continuum' against which the interstellar absorption is measured) has different shapes at phases 0.26 and 0.80, we can derive both the intrinsic stellar profiles and the interstellar absorption lines more precisely by jointly analyzing the two data sets. For the analysis of the Procyon line of sight, we first assumed that the intrinsic Ly-alpha line profile is a broadened solar profile, but this assumption does not lead to a good fit to the observed D I line profile for any value of D/H. We then assumed that (D/H)(sub LISM) = 1.6 x 10(exp -5), the same value as for the Capella line of sight, and we modified the broadened solar profile to achieve agreement between the simulated and observed line profiles. The resulting asymmetric intrinsic stellar line profile is consistent with the shapes of the scaled Mg II line profiles. We believe therefore that the Procyon data are consistent with (D/H)(sub LISM) = 1.6 x 10(exp -5), but the uncertainty in the intrinsic Ly-alpha emission-line profile does not permit us to conclude that the D/H ratio is constant in the local interstellar medium (LISM). The temperature and turbulence in the Procyon line of sight are T = 6900 +/- 80 (+/- 300 systematic error) K and zeta = 1.21 +/- 0.27 km/s. These properties are similar to those of Capella, except that the gas toward Procyon is divided into two velocity components separated by 2.6 km/s and the Procyon line of sight has a mean neutral hydrogen density that is a factor of 2.4 larger than that of the Capella line of sight. This suggests that the first 5.3 pc along the Capella line of sight lies within the local cloud and the remaining 7.2 pc lies in the hot gas surrounding the local cloud. We propose that n(H I) = 0.1065 +/- 0.0028 cm(exp -2) be adopted for the neutral hydrogen density within the local cloud and that zeta = 1.21 +/- 0.27 km/s be adopted for the nonthermal motions. The existence of different second velocity components toward the nearby stars Procyon and Sirius provides the first glimpse of a turbulent cloudlet boundary layer between the local cloud and the surrounding hot interstellar gas.

High-Reflectivity Coatings for a Vacuum Ultraviolet Spectropolarimeter

NASA Astrophysics Data System (ADS)

Narukage, Noriyuki; Kubo, Masahito; Ishikawa, Ryohko; Ishikawa, Shin-nosuke; Katsukawa, Yukio; Kobiki, Toshihiko; Giono, Gabriel; Kano, Ryouhei; Bando, Takamasa; Tsuneta, Saku; Auchère, Frédéric; Kobayashi, Ken; Winebarger, Amy; McCandless, Jim; Chen, Jianrong; Choi, Joanne

2017-03-01

Precise polarization measurements in the vacuum ultraviolet (VUV) region are expected to be a new tool for inferring the magnetic fields in the upper atmosphere of the Sun. High-reflectivity coatings are key elements to achieving high-throughput optics for precise polarization measurements. We fabricated three types of high-reflectivity coatings for a solar spectropolarimeter in the hydrogen Lyman-α (Lyα; 121.567 nm) region and evaluated their performance. The first high-reflectivity mirror coating offers a reflectivity of more than 80 % in Lyα optics. The second is a reflective narrow-band filter coating that has a peak reflectivity of 57 % in Lyα, whereas its reflectivity in the visible light range is lower than 1/10 of the peak reflectivity (˜ 5 % on average). This coating can be used to easily realize a visible light rejection system, which is indispensable for a solar telescope, while maintaining high throughput in the Lyα line. The third is a high-efficiency reflective polarizing coating that almost exclusively reflects an s-polarized beam at its Brewster angle of 68° with a reflectivity of 55 %. This coating achieves both high polarizing power and high throughput. These coatings contributed to the high-throughput solar VUV spectropolarimeter called the Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP), which was launched on 3 September, 2015.

The Surprising Absence of Absorption in the Far-ultraviolet Spectrum of Mrk 231

NASA Technical Reports Server (NTRS)

Veilleux, S.; Trippe, M.; Hamann, F.; Rupke, D. S. N.; Tripp, T. M.; Netzer, H.; Lutz, D.; Sembach, K. R.; Krug, H.; Teng, Stacy H.;

LY3127760, a Selective Prostaglandin E4 (EP4) Receptor Antagonist, and Celecoxib: A Comparison of Pharmacological Profiles.

PubMed

Jin, Yan; Smith, Claire; Hu, Leijun; Coutant, David E; Whitehurst, Kelly; Phipps, Krista; McNearney, Terry Ann; Yang, Xiao; Ackermann, Bradley; Pottanat, Thomas; Landschulz, William

2018-01-01

Safety, tolerability, and pharmacology profiles of LY3127760, an EP4 antagonist, were explored in healthy subjects in a subject/investigator-blind, parallel-group, multiple-ascending dose study. Cohorts consisted of 13 patients randomized to LY3127760, celecoxib (400 mg), or placebo (9:2:2 ratio) for 28 days. LY3127760 was well tolerated; the most commonly observed adverse events were gastrointestinal, similar to celecoxib. LY3127760 increased release of ex vivo tumor necrosis factor alpha after lipopolysaccharide/prostaglandin E2 stimulation when compared with placebo, suggesting a dose-dependent blockade of the EP4 receptor. Compared with placebo, 24-h urinary excretion of prostaglandin E metabolite was modestly increased; prostacyclin metabolite was inhibited; and thromboxane A2 metabolite was unchanged. Effects on sodium and potassium excretion were similar to those of celecoxib. We conclude that LY3127760 demonstrated similar effects on prostacyclin synthesis and renal sodium retention as celecoxib. These data support exploration of LY3127760 at daily doses of 60 mg to 600 mg in phase II trials. This trial's registration number: NCT01968070. © 2017 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Rocket and spacecraft studies of ultraviolet emissions from astrophysical targets

NASA Technical Reports Server (NTRS)

Fastie, W. G.; Moos, H. W.; Feldman, P. D.; Henry, R. C.

1975-01-01

Rocket and spacecraft far-UV spectral measurements of several astrophysical targets are reviewed. These include observations of Ly-alpha emissions from Arcturus, Apollo-17 far-UV spectrometry of eta UMa and five other stars, Apollo-17 observations of the lunar atmosphere and the diffuse UV background, and far-UV spectral studies of Venus, Jupiter, and Comet Kohoutek. The Arcturus observations indicated a chromosphere with neutral atomic-hydrogen and atomic-oxygen emissions as well as a very weak atomic-carbon line. The planetary studies revealed O I and C I emissions in the Venusian spectrum as well as large Ly-alpha emissions and possible molecular-hydrogen emissions in that of Jupiter. The lunar observations demonstrated that solar protons do not produce an atomic-hydrogen atmosphere on the moon.

Electron impact excitation of H2 - Rydberg band systems and the benchmark dissociative cross section for H Lyman-alpha

NASA Technical Reports Server (NTRS)

Shemansky, D. E.; Hall, D. T.; Ajello, J. M.

1985-01-01

The cross sections sigma R 1 (2p) for excitation of H Ly-alpha emission produced by electron impact on H2 is reexamined. A more accurate estimate for sigma R 1 (2p) is obtained based on Born approximation estimates of the H2 Rydberg system cross sections using measured relative excitation functions. The obtained value is (8.18 + or -1.2) x 10 to the -18th sq cm at 100 eV, a factor of 0.69 below the value universally applied to cross section measurements over the past decade. Cross sections for the H2 Rydberg systems fixed in magnitude by the Born approximation have also been obtained using experimentally determined excitation functions. Accurate analytic expressions for these cross sections allow the direct calculation of rate coefficients.

Constraining the Intergalactic and Circumgalactic Media with Lyman-Alpha Absorption

NASA Astrophysics Data System (ADS)

Sorini, Daniele; Onorbe, Jose; Hennawi, Joseph F.; Lukic, Zarija

2018-01-01

Lyman-alpha (Ly-a) absorption features detected in quasar spectra in the redshift range 02Mpc, the simulations asymptotically match the observations, because the ΛCDM model successfully describes the ambient IGM. This represents a critical advantage of studying the mean absorption profile. However, significant differences between the simulations, and between simulations and observations are present on scales 20kpc-2Mpc, illustrating the challenges of accurately modeling and resolving galaxy formation physics. It is noteworthy that these differences are observed as far out as ~2Mpc, indicating that the `sphere-of-influence' of galaxies could extend to approximately ~20 times the halo virial radius (~100kpc). Current observations are very precise on these scales and can thus strongly discriminate between different galaxy formation models. I demonstrate that the Ly-a absorption profile is primarily sensitive to the underlying temperature-density relationship of diffuse gas around galaxies, and argue that it thus provides a fundamental test of galaxy formation models. With near-future high-precision observations of Ly-a absorption, the tools developed in my thesis set the stage for even stronger constraints on models of galaxy formation and cosmology.

THE FIRST OBSERVATIONS OF LOW-REDSHIFT DAMPED Ly{alpha} SYSTEMS WITH THE COSMIC ORIGINS SPECTROGRAPH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meiring, J. D.; Tripp, T. M.; Prochaska, J. X.

2011-05-01

We report on the first Cosmic Origins Spectrograph observations of damped Ly{alpha} systems (DLAs) and sub-damped Ly{alpha} systems (sub-DLAs) discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have discovered three DLAs and four sub-DLAs. We measure the neutral gas density {Omega}{sub HI}, and redshift density d N/d z, of DLA and sub-DLA systems at z < 0.35. We find d N/dz = 0.25{sup +0.24}-{sub 0.14} and {Omega}{sub HI} = 1.4{sup +1.3}{sub -0.7} x 10{sup -3} for DLAs, and d N/d z = 0.08{sup +0.19}{sub -0.06} with {Omega}{sub HI} = 4.2{supmore » +9.6}{sub -3.5} x 10{sup -5} for sub-DLAs over a redshift path {Delta}z = 11.9. To demonstrate the scientific potential of such systems, we present a detailed analysis of the DLA at z{sub abs} = 0.1140 in the spectrum of SDSS J1009+0713. Profile fits to the absorption lines determine log N(H I) = 20.68 {+-} 0.10 with a metallicity determined from the undepleted element sulfur of [S/H] = -0.62 {+-} 0.18. The abundance pattern of this DLA is similar to that of higher z DLAs, showing mild depletion of the refractory elements Fe and Ti with [S/Fe] = +0.24 {+-} 0.22 and [S/Ti] = +0.28 {+-} 0.15. Nitrogen is underabundant in this system with [N/H] = -1.40 {+-} 0.14, placing this DLA below the plateau of the [N/{alpha}] measurements in the local universe at similar metallicities. This DLA has a simple kinematic structure with only two components required to fit the profiles and a kinematic width of {Delta}v{sub 90} = 52 km s{sup -1}. Imaging of the QSO field with the Hubble Space Telescope/Wide Field Camera 3 reveals a spiral galaxy at very small impact parameter to the QSO and several galaxies within 10'', or 20 comoving kpc at the redshift of the DLA. Follow-up spectra with the Low Resolution Imaging Spectrometer on the Keck telescope reveal that none of the nearby galaxies are at the redshift of the DLA. The spiral galaxy is identified as the host galaxy of the QSO based on the near perfect alignment of the nucleus and disk of the galaxy as well as spectra of an H II region showing emission lines at the QSO redshift. A small feature appears 0.''70 from the nucleus of the QSO after point-spread function subtraction, providing another candidate for the host galaxy of the DLA system. Even with these supporting data, we are unable to unambiguously identify the host galaxy of the DLA, exemplifying some of the difficulties in determining DLA hosts even at low redshift.« less

Impact of Lyman alpha pressure on metal-poor dwarf galaxies

NASA Astrophysics Data System (ADS)

Kimm, Taysun; Haehnelt, Martin; Blaizot, Jérémy; Katz, Harley; Michel-Dansac, Léo; Garel, Thibault; Rosdahl, Joakim; Teyssier, Romain

2018-04-01

Understanding the origin of strong galactic outflows and the suppression of star formation in dwarf galaxies is a key problem in galaxy formation. Using a set of radiation-hydrodynamic simulations of an isolated dwarf galaxy embedded in a 1010 M⊙ halo, we show that the momentum transferred from resonantly scattered Lyman-α (Lyα) photons is an important source of stellar feedback which can shape the evolution of galaxies. We find that Lyα feedback suppresses star formation by a factor of two in metal-poor galaxies by regulating the dynamics of star-forming clouds before the onset of supernova explosions (SNe). This is possible because each Lyα photon resonantly scatters and imparts ˜10-300 times greater momentum than in the single scattering limit. Consequently, the number of star clusters predicted in the simulations is reduced by a factor of ˜5, compared to the model without the early feedback. More importantly, we find that galactic outflows become weaker in the presence of strong Lyα radiation feedback, as star formation and associated SNe become less bursty. We also examine a model in which radiation field is arbitrarily enhanced by a factor of up to 10, and reach the same conclusion. The typical mass-loading factors in our metal-poor dwarf system are estimated to be ˜5-10 near the mid-plane, while it is reduced to ˜1 at larger radii. Finally, we find that the escape of ionizing radiation and hence the reionization history of the Universe is unlikely to be strongly affected by Lyα feedback.

Low-redshift Lyman-alpha absorption lines and the dark matter halos of disk galaxies

NASA Technical Reports Server (NTRS)

Maloney, Philip

1992-01-01

Ultraviolet observations of the low-redshift quasar 3C 273 using the Hubble Space Telescope have revealed many more Lyman-alpha absorption lines than would be expected from extrapolation of the absorption systems seen toward QSOs at z about 2. It is shown here that these absorption lines can plausibly be produced by gas at large radii in the disks of spiral and irregular galaxies; the gas is confined by the dark matter halos and ionized and heated by the extragalactic radiation field. This scenario does not require the extragalactic ionizing radiation field to decline as rapidly with decreasing z as the QSO emissivity. Observations of Ly-alpha absorption through the halos of known galaxies at low redshift will constrain both the extragalactic background and the properties of galactic halos.

The Lyman Alpha Reference Sample. V. The Impact of Neutral ISM Kinematics and Geometry on Lyα Escape

NASA Astrophysics Data System (ADS)

Rivera-Thorsen, Thøger E.; Hayes, Matthew; Östlin, Göran; Duval, Florent; Orlitová, Ivana; Verhamme, Anne; Mas-Hesse, J. Miguel; Schaerer, Daniel; Cannon, John M.; Otí-Floranes, Héctor; Sandberg, Andreas; Guaita, Lucia; Adamo, Angela; Atek, Hakim; Herenz, E. Christian; Kunth, Daniel; Laursen, Peter; Melinder, Jens

2015-05-01

We present high-resolution far-UV spectroscopy of the 14 galaxies of the Lyα Reference Sample; a sample of strongly star-forming galaxies at low redshifts (0.028 < z < 0.18). We compare the derived properties to global properties derived from multi-band imaging and 21 cm H i interferometry and single-dish observations, as well as archival optical SDSS spectra. Besides the Lyα line, the spectra contain a number of metal absorption features allowing us to probe the kinematics of the neutral ISM and evaluate the optical depth and and covering fraction of the neutral medium as a function of line of sight velocity. Furthermore, we show how this, in combination with the precise determination of systemic velocity and good Lyα spectra, can be used to distinguish a model in which separate clumps together fully cover the background source, from the “picket fence” model named by Heckman et al. We find that no one single effect dominates in governing Lyα radiative transfer and escape. Lyα escape in our sample coincides with a maximum velocity-binned covering fraction of ≲0.9 and bulk outflow velocities of ≳50 km s-1, although a number of galaxies show these characteristics and yet little or no Lyα escape. We find that Lyα peak velocities, where available, are not consistent with a strong backscattered component, but rather with a simpler model of an intrinsic emission line overlaid by a blueshifted absorption profile from the outflowing wind. Finally, we find a strong anticorrelation between Hα equivalent width and maximum velocity-binned covering factor, and propose a heuristic explanatory model. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO 11522, GO 11727, GO 12027, and GO 12583.

IUE observations of neutral hydrogen and deuterium in the local interstellar medium

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Murthy, J.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1986-01-01

Small-aperture, high-dispersion IUE spectra have been obtained of seven late-type stars that, in general, confirm previous Copernicus results concerning the distribution of hydrogen and deuterium in the local interstellar medium. In addition, the IUE Ly Alpha spectra of Altair, and of the Alpha Cen components, suggest that multiple velocity components exist in these two directions.

AMPA antagonist LY293558 does not affect the severity of hypoxic-ischemic injury in newborn pigs.

PubMed

LeBlanc, M H; Li, X Q; Huang, M; Patel, D M; Smith, E E

1995-10-01

LY293558 is a systemically active alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) excitatory amino acid antagonist. AMPA antagonists have shown promise in several adult hypoxic-ischemic brain injury models, and we wanted to see if this work could be extended to a newborn animal. Seventy-six (beta error < .10) 0- to 3-day-old piglets under 1.5% isoflurane anesthesia underwent placement of carotid snares and arterial and venous catheters. While paralyzed with succinylcholine under 0.5% isoflurane, 50% nitrous oxide, piglets were randomly assigned to receive either 5 mg/kg or 15 mg/kg of LY293558 or saline at time--10 minutes and again 10 hours later. At time 0, both carotid arteries were clamped, and blood was withdrawn to reduce the blood pressure to two thirds of normal. At time 15 minutes, inspired oxygen was reduced to 6%. At time 30 minutes, the carotid snares were released, the withdrawn blood was reinfused, and the oxygen was switched to 100%. On the third day after the hypoxic-ischemic injury, the animals were killed by perfusion of the brain with 10% formalin. Brain pathology was scored by a blinded observer. There were no significant differences between the drug-treated and control groups. The systemically active AMPA antagonist LY293558, when given at a dose of 5 mg/kg or 15 mg/kg before injury and 10 hours later, does not affect the severity of hypoxic-ischemic brain injury in newborn piglets. Neither AMPA receptor activity nor NMDA receptor activity are important in brain injury in this model.

PG 0308 + 096 and PG 1026 + 002 - Two new short period binary stars resulting from common-envelope evolution

NASA Technical Reports Server (NTRS)

Saffer, Rex A.; Wade, Richard A.; Liebert, James; Green, Richard F.; Sion, Edward M.; Bechtold, J.; Foss, Diana; Kidder, K.

1993-01-01

Ultraviolet spectroscopy, optical spectroscopy, and spectrophotometry have been used to study the excess UV stars PG 0308 + 096 and PG 1026 + 002. Both objects are short-period binary systems, each containing a DA white dwarf star and a dM star. Orbital periods of approximately 0.284 day for PG 0308 + 096, and aproximately 0.597 day for PG 1026, have been found by spectroscopic analysis of the H-alpha emission line. Ly-alpha and Balmer line profile fitting were used to estimate the mass of white dwarf stars; mass estimates for the dM stars are based on their spectral types. The orbital inclinations are derived from these masses, the periods, and amplitudes of the H-alpha radial velocity curves. The equivalent width of the H-alpha emission line, in each binary system, varies with the orbital phase in such a manner as to imply that it arises, in large part at least, from the hemisphere of the M star that faces the white dwarf star.

Insulin induces alpha1B-adrenergic receptor phosphorylation and desensitization.

PubMed

García-Sáinz, J Adolfo; Romero-Avila, M Teresa; Molina-Muñoz, Tzindilú; Medina, Luz del Carmen

2004-09-03

The ability of insulin to induce alpha1B-adrenoceptor phosphorylation and desensitization was tested in two model systems: rat-1 cells that stably express alpha1B-adrenoceptors, through transfection, and endogenously express insulin receptors and DDT1 MF2 cells that endogenously express both receptors. Insulin induced concentration-dependent increases in the phosphorylation state of the adrenergic receptors in the two models with similar EC50 values (0.5-2 nM). The effect was rapid in the two systems but it was sustained in rat-1 cells and transient in DDT1 MF2 cells. In both cell lines, the insulin-mediated phosphorylation of alpha1B-adrenoceptors was blocked by wortmannin and LY 294002, and by staurosporine and bisindolylmaleimide I, indicating that the effect involved phosphoinositide 3-kinase and protein kinase C activities. The adrenoceptor phosphorylation induced by insulin was associated to desensitization as evidences by a diminished elevation of intracellular calcium in response to noradrenaline. Inhibitors of phosphoinositide 3-kinase and protein kinase C blocked the functional desensitization induced by insulin.

A New Population of High-z, Dusty Lyman-alpha Emitters and Blobs Discovered by WISE: Feedback Caught in the Act?

NASA Technical Reports Server (NTRS)

Bridge, Carrie R.; Blain, Andrew; Borys, Colin J. K.; Petty, Sara; Benford, Dominic; Eisenhardt, Peter; Farrah, Duncan; Griffith, Roger, L.; Jarrett, Tom; Lonsdale, Carol;

Effect of intrathecal non-NMDA EAA receptor antagonist LY293558 in rats: a new class of drugs for spinal anesthesia.

PubMed

Von Bergen, Nicholas H; Subieta, Alberto; Brennan, Timothy J

2002-07-01

Excitatory amino acid receptors are important for both sensory and motor function in the spinal cord. We studied the effects of intrathecal LY293558, a competitive non-N-methyl-D-aspartate excitatory amino acid receptor antagonist, on motor and sensory function in rats to determine whether drugs blocking these receptors could potentially be used as alternative agents to local anesthetics for spinal anesthesia. Rats were tested before and 15-240 min after intrathecal injection of 5 nmol (in 10 microl) LY293558. Sensory function was tested at the hind paw using withdrawal response to pin prick and withdrawal to pinch with sharp forceps. Motor performance (ambulation, placing reflex, and Rotorod time), blood pressure, and heart rate were also evaluated. Some tests were repeated the next day. Responses after LY293558 were compared to injection of 40 microl bupivacaine, 0.75%. Pin-prick responses at the forepaw, chest, abdomen, hind leg, and hind paw were also examined after intrathecal LY293558. Intrathecal LY293558 blocked both sensory and motor responses through 180 min; complete recovery was present the following day. No change in blood pressure or heart rate occurred. The effects of LY293558 were more pronounced and sustained than those of bupivacaine. Segmental blockade of the response to pin prick was present after LY293558. Drugs like LY293558 that block alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)/kainate receptors may be an alternative to local anesthetics for spinal anesthesia in humans.

An Empirical Model of the Variation of the Solar Lyman-α Spectral Irradiance

NASA Astrophysics Data System (ADS)

Kretzschmar, Matthieu; Snow, Martin; Curdt, Werner

2018-03-01

We propose a simple model that computes the spectral profile of the solar irradiance in the hydrogen Lyman alpha line, H Ly-α (121.567 nm), from 1947 to present. Such a model is relevant for the study of many astronomical environments, from planetary atmospheres to interplanetary medium. This empirical model is based on the SOlar Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation observations of the Ly-α irradiance over solar cycle 23 and the Ly-α disk-integrated irradiance composite. The model reproduces the temporal variability of the spectral profile and matches the independent SOlar Radiation and Climate Experiment/SOLar-STellar Irradiance Comparison Experiment spectral observations from 2003 to 2007 with an accuracy better than 10%.

Beacons into the Cosmic Dark Ages: Boosted Transmission of Lyα from UV Bright Galaxies at z ≳ 7

NASA Astrophysics Data System (ADS)

Mason, Charlotte A.; Treu, Tommaso; de Barros, Stephane; Dijkstra, Mark; Fontana, Adriano; Mesinger, Andrei; Pentericci, Laura; Trenti, Michele; Vanzella, Eros

2018-04-01

Recent detections of Lyman alpha (Lyα) emission from z > 7.5 galaxies were somewhat unexpected given a dearth of previous non-detections in this era when the intergalactic medium (IGM) is still highly neutral. But these detections were from UV bright galaxies, which preferentially live in overdensities that reionize early, and have significantly Doppler-shifted Lyα line profiles emerging from their interstellar media (ISM), making them less affected by the global IGM state. Using a combination of reionization simulations and empirical ISM models we show, as a result of these two effects, that UV bright galaxies in overdensities have >2× higher transmission through the z ∼ 7 IGM than typical field galaxies, and that this boosted transmission is enhanced as the neutral fraction increases. The boosted transmission is not sufficient to explain the observed high Lyα fraction of M UV ≲ ‑22 galaxies, suggesting that Lyα emitted by these galaxies must be stronger than expected due to enhanced production and/or selection effects. Despite the bias of UV bright galaxies to reside in overdensities we show Lyα observations of such galaxies can accurately measure the global neutral hydrogen fraction, particularly when Lyα from UV faint galaxies is extinguished, making them ideal candidates for spectroscopic follow-up into the cosmic Dark Ages.

IUE monitoring of the spatial distribution of the H Ly-alpha emission from Jupiter

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Feldman, P. D.; Moos, H. W.

1981-01-01

North-south spatial maps of the Jovian H Lyman-alpha emission observed with the IUE satellite support the identification of a marked longitudinal asymmetry in the equatorial brightness, with the peak around lambda III(1965) = 50-100 deg longitude, and show a weaker planet-wide equatorial brightening above the level predicted by a plane-parallel layer model. IUE observations made 18 months after the initial discovery of the localized emission bulge establish that it is fixed with respect to Jupiter's magnetic longitude (lambda III system) and not with respect to atmospheric longitude (lambda II system). In addition, a decrease in brightness of 20% in the region of the emission bulge has been observed over a one yr interval, while the rest of the planet remained roughly constant in brightness. This decrease is more than would be expected as a result of changes in the incident solar Lyman-alpha flux, indicating a real decrease in reflectivity in this region of Jupiter's upper atmosphere.

Confirmation of a Steep Luminosity Function for Ly alpha Emitters at z 5.7: a Major Component of Reionization

NASA Technical Reports Server (NTRS)

Dressler, Alan; Henry, Alaina L.; Martin, Crystal L.; Sawicki, Marcin; McCarthy, Patrick; Villaneuva, Edward

2014-01-01

We report the first direct and robust measurement of the faint-end slope of the Ly-alpha emitter (LAE) luminosity function at z = 5.7. Candidate LAEs from a low-spectral-resolution blind search with IMACS on Magellan- Baade were targeted at higher resolution to distinguish high redshift LAEs from foreground galaxies. All but 2 of our 42 single-emission-line systems are fainter than F = 2.0×10(exp-17) ergs s(exp-1) cm(exp-2), making these the faintest emission-lines observed for a z = 5.7 sample with known completeness, an essential property for determining the faint end slope of the LAE luminosity function. We find 13 LAEs as compared to 29 foreground galaxies, in very good agreement with the modeled foreground counts predicted in Dressler et al. (2011a) that had been used to estimate a faint-end slope of alpha = -2.0 for the LAE luminosity function. A 32% LAE fraction, LAE/(LAE+foreground) within the flux interval F = 2-20 × 10(exp-18) ergs s(exp-1) cm(exp-2) constrains the faint end slope of the luminosity function to -1.95 greater than alpha greater than -2.35 (1 delta). We show how this steep LF should provide, to the limit of our observations, more than 20% of the flux necessary to maintain ionization at z = 5.7, with a factor-of-ten extrapolation in flux reaching more than 55%. We suggest that this bodes well for a comparable contribution by similar, low-mass star forming galaxies at higher-redshift - within the reionization epoch at z greater than approximately 7, only 250 Myr earlier - and that such systems provide a substantial, if not dominant, contribution to the late-stage reionization of the IGM.

Exploring Damped Ly Alpha System Host Galaxies Using Gamma-Ray Bursts

NASA Technical Reports Server (NTRS)

Toy, Vicki L.; Cucchiara, Antonino; Veilleux, Sylvain; Fumagalli, Michele; Rafelski, Marc; Rahmati, Alireza; Cenko, S. Bradley; Capone, John I.; Pasham, Dheeraj R.

2016-01-01

We present a sample of 45 Damped Ly-Alpha system [DLA; H I-N is greater than or equal to 2 x 10(exp. 20) cm(exp. -2)] counterparts (33 detections, 12 upper limits) which host gamma-ray bursts (GRB-DLAs) in order to investigate star formation and metallicity within galaxies hosting DLAs. Our sample spans z is approx. 2 - 6 and is nearly three times larger than any previously detected DLA counterparts survey based on quasar line-of-sight searches (QSO-DLAs). We report star formation rates (SFRs) from rest-frame UV photometry and spectral energy distribution modeling. We find that DLA counterpart SFRs are not correlated with either redshift or H I column density. Thanks to the combination of Hubble Space Telescope and ground-based observations, we also investigate DLA host star formation efficiency. Our GRB-DLA counterpart sample spans both higher efficiency and low efficiency star formation regions compared to the local Kennicutt-Schmidt relation, local star formation laws, and z is approximately 3 cosmological simulations. We also compare the depletion times of our DLA hosts sample to other objects in the local universe; our sample appears to deviate from the star formation efficiencies measured in local spiral and dwarf galaxies. Furthermore, we find similar efficiencies as local inner disks, SMC, and Lyman-break galaxy outskirts. Finally, our enrichment time measurements show a spread of systems with under- and over-abundance of metals, which may suggest that these systems had episodic star formation and a metal enrichment/depletion as a result of strong stellar feedback and/or metal inflow/outflow.

The quasar proximity effect in an equivalent-width-limited sample of the Lyman-alpha forest

NASA Technical Reports Server (NTRS)

Chernomordik, Viktor V.; Ozernoy, Leonid M.

1993-01-01

We have obtained a simple analytical approximation to the relationship between a rest-frame equivalent-width distribution for Ly-alpha forest absorption lines, N(W), and an H I column density distribution of the observed cloud number, N(N). Assuming a simple power-law form for N(N) proportional to N exp (1-beta), it is shown that beta = 1.4 turns out to agree fairly well with the observed form of N(W) in a broad range of column densities. We present a theoretical analysis of how the 'proximity effect' influences a W-limited sample of Ly-alpha forest lines. It is shown that this influence is considerably smaller than has been found before for a N-limited sample, for which an approximate value of beta was assumed rather than derived as has been done, for a W-limited sample, in the present paper. As a result, available observational data appear to be still consistent with the conjecture that the observed population of QSOs is the major source of the UV background at redshifts z about 2-4.

Lyman-Alpha Observations of High Radial Velocity Stars

NASA Astrophysics Data System (ADS)

Bookbinder, Jay

1990-12-01

H I LYMAN -ALPHA (LY-A) IS ONE OF THE MOST IMPORTANT LINES EMITTED BY PLASMA IN THE TEMPERATURE RANGE OF 7000 TO 10 TO THE FIFTH POWER K IN LATE-TYPE STARS. IT IS A MAJOR COMPONENT OF THE TOTAL RADIATIVE LOSS RATE, AND IT PLAYS A CRUCIAL ROLE IN DETERMINING THE ATMOSPHERIC STRUCTURE AND IN FLUORESCING OTHER UV LINES. YET IT IS ALSO THE LEAST STUDIED MAJOR LINE IN THE FAR UV, BECAUSE MOST OF THE LINE FLUX IS ABSORBED BY THE ISM ALONG THE LINE OF SIGHT AND BECAUSE IT IS STRONGLY COMTAMINATED BY THE GEOCORONAL BACKGROUND. A KNOWLEDGE OF THE Ly-A PROFILE IS ALSO IMPORTANT FOR STUDIES OF DEUTERIUM IN THE INTERSTELLAR MEDIUM. BY OBSERVING HIGH RADIAL VELOCITY STARS WE WILL OBTAIN FOR THE FIRST TIME HIGH RESOLUTION SPECTRA OF THE CORE OF A STELLAR H I LYMAN-A EMISSION LINE PROFILE.

Jovian H2 dayglow emission (1978-1989)

NASA Technical Reports Server (NTRS)

Mcgrath, M. A.; Ballester, G. E.; Moos, H. W.

1990-01-01

The IUE data set accumulated through 10 years of Jovian equatorial observations is used to measure the long-term temporal variation of the H2 dayglow emission. The model that best fits the data indicates a possible correlation between long-term solar activity and the Jovian H2 emission in the region 1500-1700 A between 1978 and 1989, which spans the decline in solar activity for solar cycle 21 and the rise in solar activity accompanying solar cycle 22. The magnitude of the observed variation is closer to that of the solar Ly-alpha flux than the 10.7 cm radio flux. Short-wavelength H2 band emission intensity is inconsistent with the amount of long-wavelength emission but may be reconciled if relatively low-energy excitation or fluorescence of solar radiation is invoked. No persistent longitudinal feature analogous to the H I Ly-alpha can be identified.

Giant Lyman-alpha Nebulae in the Illustris Simulation

NASA Astrophysics Data System (ADS)

Gronke, Max; Bird, Simeon

2017-02-01

Several “giant” Lyα nebulae with an extent ≳300 kpc and observed Lyα luminosity of ≳1044 erg s-1 cm-2 arcsec-2 have recently been detected, and it has been speculated that their presence hints at a substantial cold gas reservoir in small cool clumps not resolved in modern hydrodynamical simulations. We use the Illustris simulation to predict the Lyα emission emerging from large halos (M > 1011.5 M⊙) at z ˜ 2 and thus test this model. We consider both active galactic nucleus (AGN) and star driven ionization, and compare the simulated surface brightness maps, profiles, and Lyα spectra to a model where most gas is clumped below the simulation resolution scale. We find that with Illustris, no additional clumping is necessary to explain the extents, luminosities, and surface brightness profiles of the “giant Lyα nebulae” observed. Furthermore, the maximal extents of the objects show a wide spread for a given luminosity and do not correlate significantly with any halo properties. We also show how the detected size depends strongly on the employed surface brightness cutoff, and predict that further examples of such objects will be found in the near future.

The gravitational lens system Q0957+561 in the ultraviolet

NASA Technical Reports Server (NTRS)

Dolan, J. F.; Michalitsianos, A. G.; Thompson, R. W.; Boyd, P. T.; Wolinski, K. G.; Bless, R. C.; Nelson, M. J.; Percival, J. W.; Taylor, M. J.; Elliot, J. L.

1995-01-01

Photometric and polarimetric observations of both images of the gravitationally lensed quasar Q0957+561 (z(sub em) = 1.41) were obtained in the UV in 1993 with the High Speed Photometer on board the Hubble Space Photometer on board the Hubble Space Telescope. The images exhibited no significant polarization in a bandpass centered on 2770 A (observer's frame); p less than or = 3.2 % (2 sigma upper limit) in each image. The ratio of the flux density in image A to that in image B in late 1993 had a constant valuee, 1.021 +/- 0.008, in four different UV bandpass between 1400 A and 3040 A observer's frame). These results are consistent with the prediction of the gravitation lens interpretation that the photometric ratio of the images measured simultaneously should be independent of frequency. Reprocessed archival spectra of the two images obtained between 1981 and 1983 by the International Ultraviolet Explorer (IUE) show that the photometric ratio of A to B varies between 0.96 and 2.0 in the Ly alpha emission line, and between 0.77 and 1.8 in the O VI lambda 1037 emission line (quasar rest frame). The photometric ratio of A to B at any single epoch is often significantly different in the two emission lines. Accepting the system as a gravitational lens implies that in the quasar the flux in the Ly alpha emsisson line can vary independently of the flux in the 0 IV emission line.

Activation of Telomerase by Ionizing Radiation: Differential Response to the Inhibition of DNA Double-Strand Break Repair by Abrogation of Poly(ADP-ribosyl)ation, by LY294002, or by Wortmannin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neuhof, Dirk; Zwicker, Felix; Kuepper, Jan-Heiner

2007-11-01

Purpose: Telomerase activity represents a radiation-inducible function, which may be targeted by a double-strand break (DSB)-activated signal transduction pathway. Therefore, the effects of DNA-PK inhibitors (Wortmannin and LY294002) on telomerase upregulation after irradiation were studied. In addition, the role of trans-dominant inhibition of poly(ADP-ribosyl)ation, which strongly reduces DSB rejoining, was assessed in comparison with 3-aminobenzamide. Methods and Materials: COM3 rodent cells carry a construct for the dexamethasone-inducible overexpression of the DNA-binding domain of PARP1 and exhibit greatly impaired DSB rejoining after irradiation. Telomerase activity was measured using polymerase chain reaction ELISA 1 h after irradiation with doses up to 10more » Gy. Phosphorylation status of PKB/Akt and of PKC{alpha}/{beta}{sub II} was assessed by western blotting. Results: No telomerase upregulation was detectable for irradiated cells with undisturbed DSB rejoining. In contrast, incubation with LY294002 or dexamethasone yielded pronounced radiation induction of telomerase activity that could be suppressed by Wortmannin. 3-Aminobenzamide not only was unable to induce telomerase activity but also suppressed telomerase upregulation upon incubation with LY294002 or dexamethasone. Phospho-PKB was detectable independent of irradiation or dexamethasone pretreatment, but was undetectable upon incubations with LY294002 or Wortmannin, whereas phospho-PKC rested detectable. Conclusions: Telomerase activation postirradiation was triggered by different treatments that interfere with DNA DSB processing. This telomerase upregulation, however, was not reflected by the phosporylation status of the putative mediators of TERT activation, PKB and PKC. Although an involvement of PKB in TERT activation is not supported by the present findings, a respective role of PKC isoforms other than {alpha}/{beta}{sub II} cannot be ruled out.« less

Study of Modern Instrumentation and Methods for Astronomic Positioning in the Field

DTIC Science & Technology

1987-03-01

CALL AMAT(A.Y, UKK, KALPHA, DELTA) DO 40 kl.,2*K WR ITE( 3.300 )( A( I.M),.M=1,3) 300 FORMAT M, 3F18.12) 40 CONTINUE CALL BMAT (BY, UKKK, ALPHA, DELTA...1 20 CONTINUE RETURN END C C C SUBROUTINE BMAT (B, YU, KK, KALPHA, DELTA) C BMAT constructs the matrix 8 DIMENSION B(2*KK,3*KK)LY(KK,3),U(3),ALPHA(KK

Indication of the Hanle Effect by Comparing the Scattering Polarization Observed by CLASP in the Ly α and Si iii 120.65 nm Lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishikawa, R.; Kubo, M.; Kano, R.

The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Ly α line (121.57 nm) radiation of the solar disk. In this paper, we report that the Si iii line at 120.65 nm also shows scattering polarization and we compare the scattering polarization signals observed in the Ly α and Si iii lines in order to search for observational signatures of the Hanle effect. We focus on four selected bright structures and investigate how the U / I spatial variations vary between themore » Ly α wing, the Ly α core, and the Si iii line as a function of the total unsigned photospheric magnetic flux estimated from Solar Dynamics Observatory /Helioseismic and Magnetic Imager observations. In an internetwork region, the Ly α core shows an antisymmetric spatial variation across the selected bright structure, but it does not show it in other more magnetized regions. In the Si iii line, the spatial variation of U / I deviates from the above-mentioned antisymmetric shape as the total unsigned photospheric magnetic flux increases. A plausible explanation of this difference is the operation of the Hanle effect. We argue that diagnostic techniques based on the scattering polarization observed simultaneously in two spectral lines with very different sensitivities to the Hanle effect, like Ly α and Si iii, are of great potential interest for exploring the magnetism of the upper solar chromosphere and transition region.« less

Moderate resolution spectrophotometry of high redshift quasars

NASA Technical Reports Server (NTRS)

Schneider, Donald P.; Schmidt, Maarten; Gunn, James E.

1991-01-01

A uniform set of photometry and high signal-to-noise moderate resolution spectroscopy of 33 quasars with redshifts larger than 3.1 is presented. The sample consists of 17 newly discovered quasars (two with redshifts in excess of 4.4) and 16 sources drawn from the literature. The objects in this sample have r magnitudes between 17.4 and 21.4; their luminosities range from -28.8 to -24.9. Three of the 33 objects are broad absorption line quasars. A number of possible high redshift damped Ly-alpha systems were found.

Weighing the Low-Redshift Lyman-alpha Forest

NASA Technical Reports Server (NTRS)

Shull, Mike

2005-01-01

In 2003-2004, our FUSE research group prepared several major surveys of the amount of baryonic matter in the intergalactic medium (IGM), using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. These surveys include measurements of the Lyman-alpha absorption line of neutral hydrogen (H I), the far-ultraviolet (1032,1038 Angstrom) doublet of highly ionized oxygen ( O VI), the higher Lyman-series lines (Ly-beta, Ly-gamma, etc) of H I, and the 977 Angstrom line of c III. As an overview, our FUSE spectroscopic studies, taken together with data from the Hubble Space Telescope, show that approximately 30% of the normal matter is contained in intergalactic hydrogen gas clouds (the Lyman-alpha forest). Another 5-10% resides in hotter gas at temperatures of 10(exp 5) to 10(exp 6) K, visible in 0 VI and C III absorption. Along with the matter attributed to galaxies, we have now accounted for approximately HALF of all the baryonic matter in the universe. Where is the other half? That matter my exist in even hotter gas, invisible through the ultraviolet absorption lines, but perhaps detectable through X-ray absorption lines of more highly ionized oxygen and neon.

HST/COS Observations Of Lyman-α Emission From =0.03 Star Forming Galaxies

NASA Astrophysics Data System (ADS)

Wofford, Aida; Leitherer, C.; Salzer, J.; COS Science Team

2012-01-01

Although HI Lyman-alpha (Lyα, 1216 Å) is expected to be the strongest recombination line in HII nebulae, it is resonantly scattered by neutral hydrogen and is easily destroyed by dust. And yet, some star-forming galaxies show Lyα in emission. As evidenced by high dispersion HST/GHRS+STIS FUV spectroscopy of a handful of local (z<0.03) galaxies, the velocity shift between the neutral gas and the ionized gas plays a key role in driving the observed Lyα escape. We present HST/COS/G130M 1150-1450 Å (observed-frame) spectroscopy of 20 new targets located at a mean redshift of =0.03. The targets were selected from the KISSR survey on the basis of their GALEX FUV continuum luminosity. The observations cover the central 1-2 kpc of each galaxy, a wide range in metallicity ([O/H]=-0.83 to 0.38), and at least two orders of magnitude in FUV continuum luminosity. Seven objects show Lyα emission in the form of a P-Cygni or double-peaked profile. For 6/7 of the latter objects we are able to show that the emission is accompanied of O I gas outflows with speeds of up to 200 km/s. Two objects have Lyα luminosities comparable to the GALEX Lyα luminosities of targets at =0.3, but we find no Lyα emitters with EW(Lyα)>20 Å, such as those discovered with GALEX at z=0.2-0.35. We compare the observed Lyα/Hα line intensity ratios with predictions from dust-free cases A and B recombination under normal HII region conditions. We find evidence of O I gas inflow in the most metal-poor objects. This work is supported by NASA grant N1317.

Predicting Ly-alpha intensities in coronal streamers

NASA Technical Reports Server (NTRS)

Noci, Giancarlo; Poletto, Giannina; Suess, Steven T.; Wang, A.-H.; Wu, S. T.

1992-01-01

SOHO (Solar and Heliospheric Observatory) UVCS (Ultraviolet Coronagraph Spectrometer) will make long term observations of coronal streamers in UV lines, providing a new tool for the analysis of structures which have been known for decades but are still far from being adequately described. Work to evaluate the Lyman alpha brightness of coronal streamers is reported, adopting the streamer models obtained, via a time dependent numerical relaxation technique. This will yield understanding on the role of geometric versus physical factors in determining the streamer lyman alpha intensity and provide guidelines for UVCS observational operations. Future prospects along this line of research are summarized.

Observations of interstellar hydrogen and deuterium toward Alpha Centauri A

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1984-01-01

A composite profile is presented of the Ly-alpha emission line of Alpha Cen A, obtained from 10 individual spectra with the high-resolution spectrograph aboard the International Ultraviolet Explorer (IUE) satellite. There is excellent overall agreement with two previous Copernicus observations. Interstellar deuterium is detected, and a lower limit is set on the deuterium to hydrogen ratio of nDI/nHI greater than 8 x 10 to the -6th. In addition, the deuterium bulk velocity appears blueshifted by 8 + or - 2 km/s with respect to interstellar hydrogen, suggesting a nonuniform medium along the line of sight.

Beacons in the dark: using the most distant galaxies to probe cosmic reionization

NASA Astrophysics Data System (ADS)

De Barros, Stephane

2017-08-01

One of the major unresolved problems in modern cosmology is when and how the universe was ionized. The consensus scenario is that ultra-faint, low-mass galaxies contributed most to the UV background at high-redshift and that reionization was an inhomogeneous process, with ionized bubbles created first around galaxy overdensities. The very surprising discovery of Ly-alpha emission lines around a large fraction of the most luminous galaxies at z=7.4-8.7, when we expect the universe to be highly neutral, could thus be explained by the fact that they lie in large HII bubbles which were ionized thanks to yet undetected fainter neighbors. Theoretical models indeed predict a boost of up to 6x larger galaxy counts around the brightest sources compared to the general field, when probing down to luminosities as faint as 0.1L_UV of the central source. Here we propose a direct test of these models by searching for fainter neighbors around three bright z>7.4 galaxies emitting Ly-alpha, including two sources that lie only 9 Mpc from each other and could share the same ionized bubble, as well as the most distant confirmed Ly-alpha emitter EGSY-8p7 at z=8.68. Given the expected overdensities, we have the opportunity to detect 20 (and up to 50) new z 7-9 galaxies with only a modest investment of HST time. These observations are thus maximally efficient at providing a large number of precious high-redshift targets for early JWST spectroscopy to directly study the galaxies that are in the process of ionizing the universe. Our imaging will further enhance the legacy of the CANDELS/EGS field, and we will make the reduced data available to the community immediately for JWST follow-up.

Resolving the Structure of Ionized Helium in the Intergalactic Medium with the Far Ultraviolet Spectroscopic Explorer. 2.3

NASA Technical Reports Server (NTRS)

Kriss, G. A.; Shull, J. M.; Oegerle, W.; Zheng, W.; Davidsen, A. F.; Songaila, A.; Tumlinson, J.; Cowie, L. L.; Dehavreng, J.-M.; Friedman, S. D.

2001-01-01

The neutral hydrogen and the ionized helium absorption in the spectra of high-redshift quasi-stellar objects (QSOs) are unique probes of structure in the universe at epochs intermediate between the earliest density fluctuations seen in the cosmic background radiation and the distribution of galaxies visible today. We present Far-Ultraviolet Spectroscopic Explorer (FUSE) observations of the line of sight to the QSO HE2347-4342 in the 1000-1187 angstrom band at a resolving power of 15,000. Above redshift z = 2.7, the IGM is largely opaque in He II Ly-alpha (304 angstroms). At lower redshifts, the optical depth gradually decreases to a mean value tau = 1 at z = 2.4. We resolve the He II Ly-alpha absorption as a discrete forest of absorption lines in the z = 2.3 - 2.7 redshift range. Approximately 50% of these spectral features have H I counterparts with column densities N(sub HI) > 10(exp 12.3)/sq cm visible in a Keck spectrum. These account for most of the observed opacity in He II Ly-alpha. The remainder have N(sub HI) < 10(exp 12.3)/sq cm, below the threshold for current observations. A short extrapolation of the power-law distribution of H I column densities to lower values can account for these new absorbers. The He II to H I column density ratio eta averages approximately 80, consistent with photoionization of the IGM by a hard ionizing spectrum resulting from the integrated light of quasars at high redshift, but there is considerable scatter. Values of eta > 100 in many locations indicate that there may be localized contributions from starbursts or heavily filtered QSO radiation.

Suzaku Observations of the Ultracompact Binary System 4U1626-67

NASA Technical Reports Server (NTRS)

Camero-Arranz, A.; Pottschmidt, K.; Finger, M. H.; Wilson-Hodge, C. A.; Marcu, D. M.

2011-01-01

The accretion-powered pulsar 4U1626-67 experienced a new torque reversal at the beginning of 2008, after about 18 years of steadily spinning down. We present a spectral analysis of this source using two pointed observations performed by Suzaku in 2006 March and in 2010 September. We confirm with Suzaku the presence of a strong emission-line complex centered on 1 keV, with the strongest line being the hydrogen-like Ne Ly- alpha at 1.025(1.5) keV. We were able to resolve this complex with up to eight emission lines. A dramatic increase of the equivalent width of the Ne Ly-alpha 1.021 keV after the 2008 torque reversal occurred, reaching almost the same value measured by ASCA in 1993. In addition, we confirm the general decrease trend of the equivalent widths during the spin-down period. We also report on the detection of a cyclotron line feature centered at approx 37 keV. In spite of the fact that a dramatic increase of the X-ray luminosity (0.5-100 keV) of a factor of approx 3.5 occurred between these two observations, no significant change in the energy of the cyclotron line feature was observed. However, the intensity of the approx 1 keV line complex increased by an overall factor of approx 10.

Spectroscopic survey of the far-ultraviolet /1160-1700 A/ emissions of Capella

NASA Technical Reports Server (NTRS)

Vitz, R. C.; Weiser, H.; Moos, H. W.; Weinstein, A.; Warden, E. S.

1976-01-01

A far-ultraviolet spectral survey of Capella (Alpha Aur, G5 III + G0 III) has been obtained using a highly sensitive rocketborne spectrograph with a microchannel plate detector. The spectral distribution is very similar to that of the sun; however, if the line surface fluxes are due to the primary (G5 III), then, except for Ly-alpha, they are about an order of magnitude greater than those of the quiet sun

UV Spectral Variability and the Lyman-Alpha Forest in the Lensed Quasar Q0957+561

NASA Technical Reports Server (NTRS)

Dolan, J. F.; Michalitsianos, A. G.; Nguyen, Q. T.; Hill, R. J.

1999-01-01

Far-ultraviolet spectra of the gravitational lens components Q0957+561 A and B were obtained with the Hubble Space Telescope Faint Object Spectrograph (FOS) at five equally spaced epochs, one every two weeks. We confirm the flux variability of the quasar's Lyman-alpha and O VI lambda 1037 emission lines reported in IUE (International Ultraviolet Explorer) spectra. The fluxes in these lines vary on a time scale of weeks in the local rest frame (LRF), independently of each other and of the surrounding continuum. The individual spectra of each image were co-added to investigate the properties of the Lyman-alpha forest along the two lines of sight to the quasar. Absorption lines having equivalent width W (sub lambda) greater than or equal to 0.3 Angstroms in the LRF not previously identified as interstellar lines, metal lines, or higher order Lyman lines were taken to be LY-alpha forest lines. The existence of each line in this consistently selected set was then verified by its presence in two archival FOS spectra with approx. 1.5 times higher signal to noise than our co-added spectra. Ly-alpha forest lines with W (sub lambda) greater than or equal to 0.3 Angstroms appear at 42 distinct wavelengths in the spectra of the two images. Two absorption lines in the spectrum of image A have no counterpart at that wavelength in the spectrum of image B, and two lines in image B have no counterpart in image A. Based on the separation of the lines of sight at the redshift of the absorption lines appearing in only one spectrum, the density of the absorbing clouds in the direction of Q0957+561 must change significantly over a distance of 79 (+34, -26) h (sub 50) (sup -1) kpc in the simplified model where the absorbers are treated as spherical clouds and the characteristic dimension is the radius. (We adopt H (sub 0)= 50 h (sub 50) km s (sup -1) kpc (sup -1), q (sub 0) = 1/2, and LAMBDA = 0 throughout the paper.) The two limits define the 68% confidence interval on the characteristic dimension, equivalent to the 1 sigma confidence interval for a Gaussian distribution. The 95% confidence interval extends from (32 - 250) h (sub 50) (sup -1) kpc. We show in the Appendix that the fraction of Ly-alpha forest lines that appear in only one spectrum can be expressed as a rapidly converging power series in 1/r, where r the ratio of the radius of the cloud to the separation of the two LOS at the redshift of the cloud. This power series can be rewritten to give r in terms of the fraction of Ly-alpha forest wavelengths that appear in the spectrum of only one image. A simple linear approximation to the solution which everywhere agrees with the power series solution to better than 0.8% for r greater than or equal to 2 is derived in the Appendix.

How does ionizing radiation escape from galaxies?

NASA Astrophysics Data System (ADS)

Orlitova, Ivana

2016-10-01

Search for sources that reionized the Universe from z 15 to z 6 is one of the main drivers of present-day astronomy. Low-mass star-forming galaxies are the most favoured sources of ionizing photons, but the searches of escaping Lyman continuum (LyC) have not been extremely successful. Our team has recently detected prominent LyC escape from five Green Pea galaxies at redshift 0.3, using the HST/COS spectrograph, which represents a significant breakthrough. We propose here to study the LyC escape of the strongest among these leakers, J1152, with spatial resolution. From the comparison of the ionizing and non-ionizing radiation maps, and surface brightness profiles, we will infer the major mode in which LyC is escaping: from the strongest starburst, from the galaxy edge, through a hole along our line-of-sight, through clumpy medium, or directly from all the production sites due to highly ionized medium in the entire galaxy. In parallel, we will test the predictive power of two highly debated indirect indicators of LyC leakage: the [OIII]5007/[OII]3727 ratio, and Lyman-alpha. We predict that their spatial distribution should closely follow that of the ionizing continuum if column densities of the neutral gas are low. This combined study, which relies on the HST unique capabilities, will bring crucial information on the structure of the leaking galaxies, provide constraints for hydrodynamic simulations, and will lead to efficient future searches for LyC leakers across a large range of redshifts.

Detection of Lyman-alpha Emission from a Triply Imaged z = 6.85 Galaxy behind MACS J2129.4-0741

NASA Astrophysics Data System (ADS)

Huang, Kuang-Han; Lemaux, Brian C.; Schmidt, Kasper B.; Hoag, Austin; Bradač, Maruša; Treu, Tommaso; Dijkstra, Mark; Fontana, Adriano; Henry, Alaina; Malkan, Matthew; Mason, Charlotte; Morishita, Takahiro; Pentericci, Laura; Ryan, Russell E., Jr.; Trenti, Michele; Wang, Xin

2016-05-01

We report the detection of Lyα emission at ˜9538 Å in the Keck/DEIMOS and Hubble Space Telescope WFC3 G102 grism data from a triply imaged galaxy at z=6.846+/- 0.001 behind galaxy cluster MACS J2129.4-0741. Combining the emission line wavelength with broadband photometry, line ratio upper limits, and lens modeling, we rule out the scenario that this emission line is [O II] at z = 1.57. After accounting for magnification, we calculate the weighted average of the intrinsic Lyα luminosity to be ˜ 1.3× {10}42 {erg} {{{s}}}-1 and Lyα equivalent width to be 74 ± 15 Å. Its intrinsic UV absolute magnitude at 1600 Å is -18.6 ± 0.2 mag and stellar mass (1.5+/- 0.3)× {10}7\\quad {M}⊙ , making it one of the faintest (intrinsic {L}{UV}˜ 0.14 {L}{UV}\\ast ) galaxies with Lyα detection at z˜ 7 to date. Its stellar mass is in the typical range for the galaxies thought to dominate the reionization photon budget at z≳ 7; the inferred Lyα escape fraction is high (≳ 10%), which could be common for sub-L* z≳ 7 galaxies with Lyα emission. This galaxy offers a glimpse of the galaxy population that is thought to drive reionization, and it shows that gravitational lensing is an important avenue for probing the sub-L* galaxy population.

Angular Distribution of Ly(alpha) Resonant Photons Emergent from Optically Thick Medium

DTIC Science & Technology

2012-02-26

cosmology : theory - intergalactic medium - radiation transfer - scattering 1Division of Applied Mathematics, Brown University, Providence, RI 02912, USA...It definitely cannot be described by the Eddington approximation. The evolution of the angular distribution of resonant photons is not trivial. We

First measurement of Lyman alpha x-ray lines in hydrogen-like vanadium: results and implications for precision wavelength metrology and tests of QED

NASA Astrophysics Data System (ADS)

Gillaspy, J. D.; Chantler, C. T.; Paterson, D.; Hudson, L. T.; Serpa, F. G.; Takács, E.

2010-04-01

The first measurement of hydrogen-like vanadium x-ray Lyman alpha transitions has been made. The measurement was made on an absolute scale, fully independent of atomic structure calculations. Sufficient signal was obtained to reduce the statistical uncertainty to a small fraction of the total uncertainty budget. Potential sources of systematic error due to Doppler shifts were eliminated by performing the measurement on trapped ions. The energies for Ly α1 (1s-2p3/2) and Ly α2 (1s-2p1/2) are found to be 5443.95(25) eV and 5431.10(25) eV, respectively. These results are within approximately 1.5 σ (experimental) of the theoretical values 5443.63 eV and 5430.70 eV. The results are discussed in terms of their relation to the Lamb shift and the development of an x-ray wavelength standard based on a compact source of trapped highly charged ions.

Modeling the Scattering Polarization of the Hydrogen Ly-alpha Line Observed by CLASP in a Filament Channel

NASA Technical Reports Server (NTRS)

Stepan, J.; Trujillo Bueno, J.; Gunar, S.; del Pino Aleman, T.; Heinzel, P.; Kano, R.; Ishikawa, R.; Narukage, M.; Bando, T.; Winebarger, Amy;

Ultraviolet studies of the intergalactic medium, active galactic nuclei, and the low-z Ly-alpha forest

NASA Astrophysics Data System (ADS)

Penton, Steven Victor

1999-05-01

A database of all active galactic nuclei (AGN) observed with the International Ultraviolet Explorer (IUE, 1976-1995) was created to determine the brightest UV (1250 Å) extragalactic sources. Combined spectra, and continuum lightcurves are available for ~700 AGN. Fifteen targets were selected from this database for observation of the low-z Lyα forest with the Hubble Space Telescope. These observations were taken with the Goddard High Resolution spectrograph and the G160M grating (1991-1997). 111 significance level >3σ Lyα absorbers were detected in the redshift range, 0.002 < z < 0.069. This Thesis evaluates the physical properties of these Lyα absorbers and compares them to their high-z counterparts. In addition, we use large galaxy catalogs (i.e. the CfA Redshift Survey) to compare the relationship between known galaxies and the low-z Lyα forest. We find that the low-z absorbers are similar in physical characteristic and density to those detected at high- z. Some of these clouds appear to be primordial matter, owing to the lack of detected metallicity. A comparison to the known galaxy distribution indicates that the low-z Lyα forest clusters less than galaxies, but more than random. This suggests that at least a fraction of the absorbers are associated with the gas in galaxy associations (i.e. filaments), while a second population is distributed more uniformly. Over equal pathlengths (cΔz ~60,000 km s -1 each) of galaxy-rich and galaxy-poor environments (voids), we determine that 80% of Lyα absorbers are near large-scale galactic structures (i.e. filaments), while 20% are in galaxy voids.

Solar H-alpha features with hot onsets. III. Long fibrils in Lyman-alpha and with ALMA

NASA Astrophysics Data System (ADS)

Rutten, R. J.

2017-02-01

In H-alpha most of the solar surface is covered by dense canopies of long opaque fibrils, but predictions for quiet-Sun observations with ALMA have ignored this fact. Comparison with Ly-alpha suggests that the extraordinary opacity of H-alpha fibrils is caused by hot precursor events. Application of a recipe that assumes momentary Saha-Boltzmann extinction during their hot onset to millimeter wavelengths suggests that ALMA will observe H-alpha-like fibril canopies, not acoustic shocks underneath, and will yield data more interesting than if these canopies were transparent. An additional file is available at the end of the PDF file of this article.This study is offered as compliment to M.W.M. de Graauw. Our ways, objects, instruments and spectral domains parted after the 1970 eclipse but converge here.

Myostatin antibody (LY2495655) in older weak fallers: a proof-of-concept, randomised, phase 2 trial.

PubMed

Becker, Clemens; Lord, Stephen R; Studenski, Stephanie A; Warden, Stuart J; Fielding, Roger A; Recknor, Christopher P; Hochberg, Marc C; Ferrari, Serge L; Blain, Hubert; Binder, Ellen F; Rolland, Yves; Poiraudeau, Serge; Benson, Charles T; Myers, Stephen L; Hu, Leijun; Ahmad, Qasim I; Pacuch, Kelli R; Gomez, Elisa V; Benichou, Olivier

2015-12-01

Myostatin inhibits skeletal muscle growth. The humanised monoclonal antibody LY2495655 (LY) binds and neutralises myostatin. We aimed to test whether LY increases appendicular lean body mass (aLBM) and improves physical performance in older individuals who have had recent falls and low muscle strength and power. In this proof-of-concept, randomised, placebo-controlled, double-blind, parallel, multicentre, phase 2 study, we recruited patients aged 75 years or older who had fallen in the past year from 21 investigator sites across Argentina, Australia, France, Germany, Sweden, and the USA. Eligible patients had low performance on hand grip strength and chair rise tests, tested with the procedure described by Guralnik and colleagues. Participants were stratified by country, age, hand grip strength, and performance on the chair rise test, and were randomly assigned (1:1) by a computer-generated random sequence to receive subcutaneous injections of placebo or 315 mg LY at weeks 0 (randomisation visit), 4, 8, 12, 16, and 20, followed by 16 weeks observation. The primary outcome was change in aLBM from baseline to 24 weeks. We measured physical performance as secondary outcomes (four-step stair climbing time, usual gait speed, and time to rise five times from a chair without arms, or with arms for participants unable to do it without arms) and exploratory outcomes (12-step stair climbing test, 6-min walking distance, fast gait speed, hand grip strength, and isometric leg extension strength). Efficacy analyses included all randomly assigned patients who received at least one dose and had a baseline and at least one subsequent measure. The primary analysis and all other tests of treatment effect (except physical performance tests) were done at a two-sided alpha level of 0·05. Tests of treatment effect on physical performance tests were done at a pre-specified two-sided alpha level of 0·1. This trial is registered with ClinicalTrials.gov, number NCT01604408. Between June 19, 2012, and Dec 12, 2013, we screened 365 patients. 99 were randomly assigned to receive placebo and 102 to receive LY. Treatment was completed in 85 (86%) of patients given placebo and in 82 (80%) given LY. At 24 weeks, the least-squares mean change in aLBM was -0·123 kg (95% CI -0·287 to 0·040) in the placebo group and 0·303 kg (0·135 to 0·470) in the LY group, a difference of 0·43 kg (95% CI 0·192 to 0·660; p<0·0001). Stair climbing time (four-step and 12-step tests), chair rise with arms, and fast gait speed improved significantly from baseline to week 24 with differences between LY and placebo of respectively -0·46 s (p=0·093), -1·28 s (p=0·011), -4·15 s (p=0·054), and 0·05 m/s (p=0·088). No effect was detected for other performance-based measures. Injection site reactions were recorded in nine (9%) patients given placebo and in 31 (30%) patients given LY (p<0·0001), and were generally mild, and led to treatment discontinuation in two patients given LY. Our findings show LY treatment increases lean mass and might improve functional measures of muscle power. Although additional studies are needed to confirm these results, our data suggest LY should be tested for its potential ability to reduce the risk of falls or physical dependency in older weak fallers. Eli Lilly and Company. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fluid shear stress inhibits TNF-alpha-induced apoptosis in osteoblasts: a role for fluid shear stress-induced activation of PI3-kinase and inhibition of caspase-3

NASA Technical Reports Server (NTRS)

Pavalko, Fredrick M.; Gerard, Rita L.; Ponik, Suzanne M.; Gallagher, Patricia J.; Jin, Yijun; Norvell, Suzanne M.

2003-01-01

In bone, a large proportion of osteoblasts, the cells responsible for deposition of new bone, normally undergo programmed cell death (apoptosis). Because mechanical loading of bone increases the rate of new bone formation, we hypothesized that mechanical stimulation of osteoblasts might increase their survival. To test this hypothesis, we investigated the effects of fluid shear stress (FSS) on osteoblast apoptosis using three osteoblast cell types: primary rat calvarial osteoblasts (RCOB), MC3T3-E1 osteoblastic cells, and UMR106 osteosarcoma cells. Cells were treated with TNF-alpha in the presence of cyclohexamide (CHX) to rapidly induce apoptosis. Osteoblasts showed significant signs of apoptosis within 4-6 h of exposure to TNF-alpha and CHX, and application of FSS (12 dyne/cm(2)) significantly attenuated this TNF-alpha-induced apoptosis. FSS activated PI3-kinase signaling, induced phosphorylation of Akt, and inhibited TNF-alpha-induced activation of caspase-3. Inhibition of PI3-kinase, using LY294002, blocked the ability of FSS to rescue osteoblasts from TNF-alpha-induced apoptosis and blocked FSS-induced inhibition of caspase-3 activation in osteoblasts treated with TNF-alpha. LY294002 did not, however, prevent FSS-induced phosphorylation of Akt suggesting that activation of Akt alone is not sufficient to rescue cells from apoptosis. This result also suggests that FSS can activate Akt via a PI3-kinase-independent pathway. These studies demonstrate for the first time that application of FSS to osteoblasts in vitro results in inhibition of TNF-alpha-induced apoptosis through a mechanism involving activation of PI3-kinase signaling and inhibition of caspases. FSS-induced activation of PI3-kinase may promote cell survival through a mechanism that is distinct from the Akt-mediated survival pathway. Copyright 2002 Wiley-Liss, Inc.

Structural basis of selectivity and neutralizing activity of a TGFα/epiregulin specific antibody.

PubMed

Boyles, Jeffrey S; Atwell, Shane; Druzina, Zhanna; Heuer, Josef G; Witcher, Derrick R

2016-11-01

Recent studies have implicated a role of the epidermal growth factor receptor (EGFR) pathway in kidney disease. Skin toxicity associated with therapeutics which completely block the EGFR pathway precludes their use in chronic dosing. Therefore, we developed antibodies which specifically neutralize the EGFR ligands TGFα (transforming growth factor-alpha) and epiregulin but not EGF (epidermal growth factor), amphiregulin, betacellulin, HB-EGF (heparin-binding epidermal growth factor), or epigen. The epitope of one such neutralizing antibody, LY3016859, was characterized in detail to elucidate the structural basis for ligand specificity. Here we report a crystal structure of the LY3016859 Fab fragment in complex with soluble human TGFα. Our data demonstrate a conformational epitope located primarily within the C-terminal subdomain of the ligand. In addition, point mutagenesis experiments were used to highlight specific amino acids which are critical for both antigen binding and neutralization, most notably Ala 41 , Glu 44 , and His 45 . These results illustrate the structural basis for the ligand specificity/selectivity of LY3016859 and could also provide insight into further engineering to alter specificity and/or affinity of LY3016859. © 2016 The Protein Society.

Direct evidence for Lyboldsymbol{alpha } depletion in the protocluster core

NASA Astrophysics Data System (ADS)

Shimakawa, Rhythm; Kodama, Tadayuki; Hayashi, Masao; Tanaka, Ichi; Matsuda, Yuichi; Kashikawa, Nobunari; Shibuya, Takatoshi; Tadaki, Ken-ichi; Koyama, Yusei; Suzuki, Tomoko L.; Yamamoto, Moegi

2017-06-01

We have carried out panoramic Lyα narrow-band imaging with Suprime-Cam on Subaru towards the known protocluster USS1558-003 at z = 2.53. Our previous narrow-band imaging in the near-infrared identified multiple dense groups of Hα emitters (HAEs) within the protocluster. We have now identified the large-scale structures across a ˜50 comoving Mpc scale traced by Lyα emitters (LAEs) in which the protocluster traced by the HAEs is embedded. On a smaller scale, however, there are remarkably few LAEs in the regions of HAE overdensities. Moreover, the stacking analyses of the images show that HAEs in higher-density regions show systematically lower escape fractions of Lyα photons than those of HAEs in lower-density regions. These phenomena may be driven by the extra depletion of Lyα emission lines along our line of sight by more intervening cold circumgalactic/intergalactic medium and/or dust in the dense core. We also caution that all the previous high-z protocluster surveys using LAEs as tracers would have largely missed galaxies in the very dense cores of the protoclusters where we would expect to see any early environmental effects.

Optical Alignment of the Chromospheric Lyman-Alpha SpectroPolarimeter using Sophisticated Methods to Minimize Activities under Vacuum

NASA Technical Reports Server (NTRS)

Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.; Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.;

Development of High-Resolution UV-VIS Diagnostics for Space Plasma Simulation

NASA Astrophysics Data System (ADS)

Taylor, Andrew; Batishchev, Oleg

2012-10-01

Non-invasive far-UV-VIS plasma emission allows remote diagnostics of plasma, which is particularly important for space application. Accurate vacuum tank space plasma simulations require monochromators with high spectral resolution (better than 0.01A) to capture important details of atomic and ionic lines, such as Ly-alpha, etc. We are building a new system based on the previous work [1], and will discuss the development of a spectrometry system that combines a single-pass vacuum far-UV-NIR spectrometer and a tunable Fabry-Perot etalon. [4pt] [1] O. Batishchev and J.L. Cambier, Experimental Study of the Mini-Helicon Thruster, Air Force Research Laboratory Report, AFRL-RZ-ED-TR-2009-0020, 2009.

Searching for the UV counterpart of the extraordinary X-ray UFO in the NLSy1 IRAS17020+4544

NASA Astrophysics Data System (ADS)

Krongold, Yair

2017-08-01

We recently reported the first unambiguous discovery in high resolution X-ray data of an ultra fast outflow (UFO) with velocity .1c. This wind, in Narrow Line Seyfert 1 galaxy IRAS17020+4544, represents so far the most compelling detection of an UFO, with many different absorption lines that give rise to very high significance detections. The charge states that form the wind clearly indicate a large range of ionization states in the gas, and significant absorption by Ly alpha, C IV, Si IV and N V (among other ions) is expected in the UV band. The goal of our proposed program is to observe an characterize the best X-ray detected UFO in the UV. These observations are crucial to study in great detail the UFO phenomenon, and understand its nature and its relation to the narrow absorption line low velocity systems. Only through detection of Ly alpha absorption in the UV data, measurements of the metallicity of these winds will be possible. The proposed program will help guide new theoretical models of UFOs origins, beyond the simple actual picture that predicts only very high ionization Fe absorption. UV data are required to understand the wind nature and launching mechanism (whether due to radiation pressure via line or continuum opacity, or magnetic forces). Fully characterizing the wind properties will put stronger constraints in the mass outflow and kinetic outflow rates of these systems, as well as in their geometry. Such estimates will give a much clearer picture of UFOs feedback potential, and will provide clues on the feedback mode in action (e.g. energy conserving vs. momentum conserving).

Search for Jovian auroral hot spots

NASA Technical Reports Server (NTRS)

Atreya, S. K.; Barker, E. S.; Yung, Y. L.; Donahue, T. M.

1977-01-01

Auroral emission originating at the foot of the Io-associated flux tube at Jupiter has been detected with a high-resolution spectrometer/telescope on board the Orbiting Astronomical Observatory Copernicus. The emission intensity at Ly-alpha is found to be greater than 100 kR, and the emission is located at zenographic latitudes greater than 65 deg.

THE SPECTRALLY RESOLVED Lyα EMISSION OF THREE Lyα-SELECTED FIELD GALAXIES AT z ∼ 2.4 FROM THE HETDEX PILOT SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chonis, Taylor S.; Finkelstein, Steven L.; Gebhardt, Karl

2013-10-01

We present new results on the spectrally resolved Lyα emission of three Lyα-emitting field galaxies at z ∼ 2.4 with high Lyα equivalent width (>100 Å) and Lyα luminosity (∼10{sup 43} erg s{sup –1}). At 120 km s{sup –1} (FWHM) spectral resolution, the prominent double-peaked Lyα profile straddles the systemic velocity, where the velocity zero point is determined from spectroscopy of the galaxies' rest-frame optical nebular emission lines. The average velocity offset from systemic of the stronger redshifted emission component for our sample is 176 km s{sup –1} while the average total separation between the redshifted and main blueshifted emissionmore » components is 380 km s{sup –1}. These measurements are a factor of ∼2 smaller than for UV-continuum-selected galaxies that show Lyα in emission with lower Lyα equivalent widths. We compare our Lyα spectra to the predicted line profiles of a spherical 'expanding shell' Lyα radiative transfer grid that models large-scale galaxy outflows. Specifically, blueward of the systemic velocity where two galaxies show a weak, highly blueshifted (by ∼1000 km s{sup –1}) tertiary emission peak, the model line profiles are a relatively poor representation of the observed spectra. Since the neutral gas column density has a dominant influence over the shape of the Lyα line profile, we caution against equating the observed Lyα velocity offset with a physical outflow velocity, especially at lower spectral resolution where the unresolved Lyα velocity offset is a convoluted function of several degenerate parameters. Referring to rest-frame ultraviolet and optical Hubble Space Telescope imaging, we find that galaxy-galaxy interactions may play an important role in inducing a starburst that results in copious Lyα emission as well as perturbing the gas distribution and velocity field, both of which have strong influence over the Lyα emission line profile.« less

The Evolution of Ly-alpha Emitting Galaxies Between z = 2.1 and z = 3.l

NASA Technical Reports Server (NTRS)

Ciardullo, Robin; Gronwall,Caryl; Wolf, Christopher; McCathran, Emily; Bond, Nicholas A.; Gawiser, Eric; Guaita, Lucia; Feldmeier, John J.; Treister, Ezequiel; Padilla, Nelson;

First Spectroscopic Confirmations of z ∼ 7.0 Ly α Emitting Galaxies in the LAGER Survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Weida; Wang, Junxian; Kang, Wenyong

Narrowband imaging is a highly successful approach for finding large numbers of high-redshift Ly α emitting galaxies (LAEs) up to z ∼ 6.6. However, at z ≳ 7 there are as of yet only three narrowband selected LAEs with spectroscopic confirmations (two at z ∼ 6.9–7.0, one at z ∼ 7.3), which hinders extensive studies on cosmic reionization and galaxy evolution at this key epoch. We have selected 23 candidate z ∼ 6.9 LAEs in COSMOS field with the large area narrowband survey Lyman-Alpha Galaxies at the End of Reionization (LAGER). In this work, we present spectroscopic follow-up observations ofmore » 12 candidates using the Inamori Magellan Areal Camera and Spectrograph on Magellan. For nine of these, the observations are sufficiently deep to detect the expected lines. Ly α emission lines are identified in six sources (yielding a success rate of 2/3), including three luminous LAEs with Ly α luminosities of L {sub Lyα} ∼ 10{sup 43.5} erg s{sup −1}, the highest among known spectroscopically confirmed galaxies at ≳7.0. This triples the sample size of spectroscopically confirmed narrowband selected LAEs at z ≳ 7, and confirms the bright-end bump in the Ly α luminosity function we previously derived based on the photometric sample, supporting a patchy reionization scenario. Two luminous LAEs appear physically linked with a projected distance of 1.1 pMpc and velocity difference of ∼170 km s{sup −1}. They likely sit in a common ionized bubble produced by themselves or with close neighbors, which reduces the intergalactic medium attenuation of Ly α . A tentative narrow N v λ 1240 line is seen in one source, hinting at activity of a central massive black hole with metal-rich line-emitting gas.« less

The Lyα properties of faint galaxies at z ∼ 2-3 with systemic redshifts and velocity dispersions from Keck-MOSFIRE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erb, Dawn K.; Steidel, Charles C.; Trainor, Ryan F.

2014-11-01

We study the Lyα profiles of 36 spectroscopically detected Lyα-emitters (LAEs) at z ∼ 2-3, using Keck MOSFIRE to measure systemic redshifts and velocity dispersions from rest-frame optical nebular emission lines. The sample has a median optical magnitude R=26.0, and ranges from R≃23 to R>27, corresponding to rest-frame UV absolute magnitudes M {sub UV} ≅ –22 to M {sub UV} > –18.2. Dynamical masses range from M {sub dyn} < 1.3 × 10{sup 8} M {sub ☉} to M {sub dyn} = 6.8 × 10{sup 9} M {sub ☉}, with a median value of M {sub dyn} = 6.3 ×more » 10{sup 8} M {sub ☉}. Thirty of the 36 Lyα emission lines are redshifted with respect to the systemic velocity with at least 1σ significance, and the velocity offset with respect to systemic Δv {sub Lyα} is correlated with the R-band magnitude, M {sub UV}, and the velocity dispersion measured from nebular emission lines with >3σ significance: brighter galaxies with larger velocity dispersions tend to have larger values of Δv {sub Lyα}. We also make use of a comparison sample of 122 UV-color-selected R<25.5 galaxies at z ∼ 2, all with Lyα emission and systemic redshifts measured from nebular emission lines. Using the combined LAE and comparison samples for a total of 158 individual galaxies, we find that Δv {sub Lyα} is anti-correlated with the Lyα equivalent width with 7σ significance. Our results are consistent with a scenario in which the Lyα profile is determined primarily by the properties of the gas near the systemic redshift; in such a scenario, the opacity to Lyα photons in lower mass galaxies may be reduced if large gaseous disks have not yet developed and if the gas is ionized by the harder spectrum of young, low metallicity stars.« less

Hydrogen and deuterium in the local interstellar medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murthy, J.N.

1987-01-01

This work reports on the results of a series of IUE observations of interstellar HI and DI Ly..cap alpha.. absorption against the chromospheric Ly..cap alpha.. emission of the nearby late-type stars ..cap alpha.. Cen B(1.3 pc), epsilon Eri (3.3 pc), Procyon (3.5 pc), Altair (5.1 pc), Capella (13.2 pc), and HR 1099 (33 pc). The density, velocity dispersion, and bulk velocity of the neutral hydrogen along the line of sight to each of these stars was derived. Lower limits were placed on the deuterium-to-hydrogen (D/H) ratio towards the same stars. These IUE results are generally consistent with previous observations ofmore » the same stars with the Copernicus satellite showing that this modeling procedure is independent of stellar variations over a period of several years. The HI absorption profile towards Altair shows a broad saturated core and steep line wings, consistent with a multicomponent interstellar medium in that direction. The bulk velocities towards the other stars are consistent with a bulk flow from the approximate direction of the galactic center but do show local variations from a uniform flow, possibly indicating a complicated velocity structure even in the solar neighborhood. Interstellar deuterium is detected towards every star except Altair and the derived values for the D/H ratio are consistent with those previously found with Copernicus.« less

Lyman-alpha forests cool warm dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baur, Julien; Palanque-Delabrouille, Nathalie; Yèche, Christophe

2016-08-01

The free-streaming of keV-scale particles impacts structure growth on scales that are probed by the Lyman-alpha forest of distant quasars. Using an unprecedentedly large sample of medium-resolution QSO spectra from the ninth data release of SDSS, along with a state-of-the-art set of hydrodynamical simulations to model the Lyman-alpha forest in the non-linear regime, we issue one of the tightest bounds to date, from Ly-α data alone, on pure dark matter particles: m{sub X} >4.09 keV (95% CL) for early decoupled thermal relics such as a hypothetical gravitino, and correspondingly m{sub s} >24.4 keV (95% CL) for a non-resonantly produced right-handedmore » neutrino. This limit depends on the value on n {sub s} , and Planck measures a higher value of n {sub s} than SDSS-III/BOSS. Our bounds thus change slightly when Ly-α data are combined with CMB data from Planck 2016. The limits shift to m{sub X} >2.96 keV (95% CL) and m{sub s} >16.0 keV (95% CL). Thanks to SDSS-III data featuring smaller uncertainties and covering a larger redshift range than SDSS-I data, our bounds confirm the most stringent results established by previous works and are further at odds with a purely non-resonantly produced sterile neutrino as dark matter.« less

Observing Supernova 1987A with the Refurbished Hubble Space Telescope

NASA Technical Reports Server (NTRS)

France, Kevin; McCray, Richard; Heng, Kevin; Kirshner, Robert P.; Challis, Peter; Bouchet, Patrice; Crotts, Arlin; Dwek, Eli; Fransson, Claes; Garnavich, Peter M.;

27ps DFT Molecular Dynamics Simulation of a-maltose: A Reduced Basis Set Study.

USDA-ARS?s Scientific Manuscript database

DFT molecular dynamics simulations are time intensive when carried out on carbohydrates such as alpha-maltose, requiring up to three or more weeks on a fast 16-processor computer to obtain just 5ps of constant energy dynamics. In a recent publication [1] forces for dynamics were generated from B3LY...

Ultraviolet emissions from the upper atmospheres of the planets

NASA Technical Reports Server (NTRS)

Moos, H. W.

1981-01-01

Some recent results on planetary upper atmospheres obtained by means of orbiting ultraviolet observatories are reviewed with emphasis on Jupiter and Io torus. Consideration is given to long-term variation in Jovian Ly alpha emission, UV polar auroras on Jupiter, and UV emission from the Io torus. Requirements for UV planetary astronomy are briefly discussed.

CLASP2: The Chromospheric LAyer Spectro-Polarimeter

NASA Astrophysics Data System (ADS)

Rachmeler, Laurel; E McKenzie, David; Ishikawa, Ryohko; Trujillo Bueno, Javier; Auchère, Frédéric; Kobayashi, Ken; Winebarger, Amy; Bethge, Christian; Kano, Ryouhei; Kubo, Masahito; Song, Donguk; Narukage, Noriyuki; Ishikawa, Shin-nosuke; De Pontieu, Bart; Carlsson, Mats; Yoshida, Masaki; Belluzzi, Luca; Stepan, Jiri; del Pino Alemná, Tanausú; Ballester, Ernest Alsina; Asensio Ramos, Andres

2017-08-01

We present the instrument, science case, and timeline of the CLASP2 sounding rocket mission. The successful CLASP (Chromospheric Lyman-Alpha Spectro-Polarimeter) sounding rocket flight in 2015 resulted in the first-ever linear polarization measurements of solar hydrogen Lyman-alpha line, which is sensitive to the Hanle effect and can be used to constrain the magnetic field and geometric complexity of the upper chromosphere. Ly-alpha is one of several upper chromospheric lines that contain magnetic information. In the spring of 2019, we will re-fly the modified CLASP telescope to measure the full Stokes profile of Mg II h & k near 280 nm. This set of lines is sensitive to the upper chromospheric magnetic field via both the Hanle and the Zeeman effects.

A High Space Density of Luminous Lyman Alpha Emitters at z ∼ 6.5

NASA Astrophysics Data System (ADS)

Bagley, Micaela B.; Scarlata, Claudia; Henry, Alaina; Rafelski, Marc; Malkan, Matthew; Teplitz, Harry; Dai, Y. Sophia; Baronchelli, Ivano; Colbert, James; Rutkowski, Michael; Mehta, Vihang; Dressler, Alan; McCarthy, Patrick; Bunker, Andrew; Atek, Hakim; Garel, Thibault; Martin, Crystal L.; Hathi, Nimish; Siana, Brian

2017-03-01

We present the results of a systematic search for Lyα emitters (LAEs) at 6≲ z≲ 7.6 using the HST WFC3 Infrared Spectroscopic Parallel (WISP) Survey. Our total volume over this redshift range is ∼ 8× {10}5 Mpc3, comparable to many of the narrowband surveys despite their larger area coverage. We find two LAEs at z = 6.38 and 6.44 with line luminosities of {L}Lyα }∼ 4.7× {10}43 erg s‑1, putting them among the brightest LAEs discovered at these redshifts. Taking advantage of the broad spectral coverage of WISP, we are able to rule out almost all lower-redshift contaminants. The WISP LAEs have a high number density of 7.7× {10}-6 Mpc‑3. We argue that the LAEs reside in megaparsec-scale ionized bubbles that allow the Lyα photons to redshift out of resonance before encountering the neutral intergalactic medium. We discuss possible ionizing sources and conclude that the observed LAEs alone are not sufficient to ionize the bubbles.

Ada Compiler Validation Summary Report: Certificate Number: 940325S1. 11348 DDC-I, DACS Sun SPARC/Solaris to 80386 PM Bare Ada Cross Compiler System, Version 4.6.4 Sun SPARCclassic = Intel iSBC 386/116 (Bare Machine)

DTIC Science & Technology

1994-03-25

digits than SYSTEM.MAXDIGITS: C24113L..Y (14 tests) C35705L..Y (14 tests) C35706L..Y (14 tests) C35707L..Y (14 tests) 2-1 C35708L..Y (14 tests) C35802L...MACHINE CODETYPE : REGISTERTYPE MANTISSADOC : 31 A-2 MAX_- DIGITS : 15 MAX_-INT : 9223372036854775807 MAX_-INTPLUS_1 : 9223372036854775808 MIN_ INT...words. A libary task is formed when a task object is declared at the outermost level of a package. Library tasks ame created and activated during the

The discovery of a young radio galaxy at z = 2.390 - Probing initial star formation at z less than approximately 3.0

NASA Technical Reports Server (NTRS)

Windhorst, Rogier A.; Burstein, David; Mathis, Doug F.; Neuschaefer, Lyman W.; Bertola, F.; Buson, L. M.; Koo, David C.; Matthews, Keith; Barthel, Peter D.; Chambers, K. C.

1991-01-01

The discovery of a weak radio galaxy from the Leiden Berkeley Deep Survey at a redshift of 2.390 is presented, as well as nine-band photometry for the galaxy and for surrounding objects. The source 53W002 is not variable on the time scales of years. Its rest-frame UV continuum is compared with IUE spectra of various nearby galaxies with relatively recent starbursts, and with nearby AGNs. It is inferred from the C IV/Ly-alpha and N V/Ly-alpha ratios that 53W002 has a Seyfert 1-like AGN, and that the ratios constrain the nonthermal component to about 35 percent of the observed UV continuum. Several independent age estimates yield a consistent value of 0.25-0.32 Gyr. The available data are consistent with 53W002 being a genuinely young galaxy seen at a redshift of 2.390 during its first major starburst. It likely started forming most of its current stars at redshifts between 2.5 and 3.0, suggesting that radio galaxies do not form the bulk of their stars coevally, but start doing so over a lengthy period of cosmic time.

The Properties of the local Interstellar Medium and the Interaction of the Stellar Winds of epsilon Indi and lambda Andromedae with the Interstellar Environment

NASA Technical Reports Server (NTRS)

Wood, Brian E.; Alexander, William R.; Linsky, Jeffrey L.

1996-01-01

We present new observations of the Ly alpha lines of Epsilon Indi (K5 5) and A Andromedae (G8 4-3 + ?) These data were obtained by the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. Analysis of the interstellar H 1 and D 1 absorption lines reveals that the velocities and temperatures inferred from the H 1 lines are inconsistent with the parameters inferred from the D 1 lines, unless the H 1 absorption is assumed to be produced by two absorption components. One absorption component is produced by interstellar material. For both lines of sight observed, the velocity of this component is consistent with the velocity predicted by the local flow vector. For the Epsilon Indi data, the large velocity separation between the stellar emission and the interstellar absorption allows us to measure the H 1 column density independent of the shape of the intrinsic stellar Ly alpha profile. This approach permits us to quote an accurate column density and to assess its uncertainty with far more confidence than in previous analyses, for which the errors were dominated by uncertainties in the assumed stellar profiles.

Quasar Feedback at the Peak of the Galaxy Formation Epoch

NASA Astrophysics Data System (ADS)

Liu, Guilin; Zakamska, Nadia L.; Strauss, Michael A.; Greene, Jenny E.; Alexandroff, Rachael

2014-08-01

The correlations between properties of supermassive black holes and stellar spheroids in galaxies imply a physical connection between these two components. Using Gemini GMOS IFU, we demonstrated that powerful ionized gas winds are ubiquitous in luminous radio-quiet z~ 0.5 quasars. We now extend this study to the era of peak galaxy formation and quasar activity when quasar feedback likely shaped the properties of massive galaxies. Our GMOS IFU observations of 5 quasars at z~ 3 are now underway, and we plan for fall observations. We propose a GMOS IFU survey to map the spatial distribution and kinematics of Ly(alpha) and N V 1240Aemission around 5 obscured quasars at z=3-3.3 that are extremely luminous (L_Ly(alpha)~10^45 erg s^- 1). Obscured quasars likely constitute the majority of the quasar population and represent the early enshrouded phase of black hole growth, luminous obscured quasars are thus the most likely sites of quasar feedback, as we found at low redshifts. We will look for quasar- driven outflows, and directly probe the effects of quasars on their galaxy-wide and intergalactic environments close to the peak of the galaxy formation epoch.

NMDA receptors regulate nicotine-enhanced brain reward function and intravenous nicotine self-administration: role of the ventral tegmental area and central nucleus of the amygdala.

PubMed

Kenny, Paul J; Chartoff, Elena; Roberto, Marisa; Carlezon, William A; Markou, Athina

2009-01-01

Nicotine is considered an important component of tobacco responsible for the smoking habit in humans. Nicotine increases glutamate-mediated transmission throughout brain reward circuitries. This action of nicotine could potentially contribute to its intrinsic rewarding and reward-enhancing properties, which motivate consumption of the drug. Here we show that the competitive N-methyl-D-aspartate (NMDA) receptor antagonist LY235959 (0.5-2.5 mg per kg) abolished nicotine-enhanced brain reward function, reflected in blockade of the lowering of intracranial self-stimulation (ICSS) thresholds usually observed after experimenter-administered (0.25 mg per kg) or intravenously self-administered (0.03 mg per kg per infusion) nicotine injections. The highest LY235959 dose (5 mg per kg) tested reversed the hedonic valence of nicotine from positive to negative, reflected in nicotine-induced elevations of ICSS thresholds. LY235959 doses that reversed nicotine-induced lowering of ICSS thresholds also markedly decreased nicotine self-administration without altering responding for food reinforcement, whereas the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonist NBQX had no effects on nicotine intake. In addition, nicotine self-administration upregulated NMDA receptor subunit expression in the central nucleus of the amygdala (CeA) and ventral tegmental area (VTA), suggesting important interactions between nicotine and the NMDA receptor. Furthermore, nicotine (1 microM) increased NMDA receptor-mediated excitatory postsynaptic currents in rat CeA slices, similar to its previously described effects in the VTA. Finally, infusion of LY235959 (0.1-10 ng per side) into the CeA or VTA decreased nicotine self-administration. Taken together, these data suggest that NMDA receptors, including those in the CeA and VTA, gate the magnitude and valence of the effects of nicotine on brain reward systems, thereby regulating motivation to consume the drug.

The non-linear power spectrum of the Lyman alpha forest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arinyo-i-Prats, Andreu; Miralda-Escudé, Jordi; Viel, Matteo

2015-12-01

The Lyman alpha forest power spectrum has been measured on large scales by the BOSS survey in SDSS-III at z∼ 2.3, has been shown to agree well with linear theory predictions, and has provided the first measurement of Baryon Acoustic Oscillations at this redshift. However, the power at small scales, affected by non-linearities, has not been well examined so far. We present results from a variety of hydrodynamic simulations to predict the redshift space non-linear power spectrum of the Lyα transmission for several models, testing the dependence on resolution and box size. A new fitting formula is introduced to facilitate themore » comparison of our simulation results with observations and other simulations. The non-linear power spectrum has a generic shape determined by a transition scale from linear to non-linear anisotropy, and a Jeans scale below which the power drops rapidly. In addition, we predict the two linear bias factors of the Lyα forest and provide a better physical interpretation of their values and redshift evolution. The dependence of these bias factors and the non-linear power on the amplitude and slope of the primordial fluctuations power spectrum, the temperature-density relation of the intergalactic medium, and the mean Lyα transmission, as well as the redshift evolution, is investigated and discussed in detail. A preliminary comparison to the observations shows that the predicted redshift distortion parameter is in good agreement with the recent determination of Blomqvist et al., but the density bias factor is lower than observed. We make all our results publicly available in the form of tables of the non-linear power spectrum that is directly obtained from all our simulations, and parameters of our fitting formula.« less

The HI Environment of Nearby Lyman-alpha Absorbers

NASA Technical Reports Server (NTRS)

VanGorkom, J. H.; Carilli, C. L.; Stocke, John T.; Perlman, Eric S.; Shull, J. Michael

1996-01-01

We present the results of a VLA and WSRT search for H I emission from the vicinity of seven nearby clouds, which were observed in Ly-alpha absorption with HST toward Mrk 335, Mrk 501, and PKS 2155-304. Around the absorbers, we searched a volume of 4O' x 40' x 1000 km/s; for one of the absorbers we probed a velocity range of only 600 km/s. The H I mass sensitivity (5 sigma) very close to the lines of sight varies from 5 x 10(exp 6) solar mass at best to 5 x 10(exp 8) solar mass at worst. We detected H I emission in the vicinity of four out of seven absorbers. The closest galaxy we find to the absorbers is a small dwarf galaxy at a projected distance of 68 h(exp -1) kpc from the sight line toward Mrk 335. This optically uncataloged galaxy has the same velocity (V = 1970 km/s) as one of the absorbers, is fainter than the SMC, and has an H I mass of only 4 x 10(exp 7) solar mass. We found a somewhat more luminous galaxy at exactly the velocity (V = 5100 km/s) of one of the absorbers toward PKS 2155-304 at a projected distance of 230 h(exp -1) kpc from the sight line. Two other, stronger absorbers toward PKS 2155-304 at V approx. 17,000 km/s appear to be associated with a loose group of three bright spiral galaxies, at projected distances of 300 to 600 h(exp -1) kpc. These results support the conclusions emerging from optical searches that most nearby Ly-alpha forest clouds trace the large-scale structures outlined by the optically luminous galaxies, although this is still based on small-number statistics. We do not find any evidence from the H I distribution or kinematics that there is a physical association between an absorber and its closest galaxy. While the absorbing clouds are at the systemic velocity of the galaxies, the H I extent of the galaxies is fairly typical, and at least an order of magnitude smaller than the projected distance to the sight line at which the absorbers are seen. On the other hand, we also do not find evidence against such a connection. In total, we detected H I emission from five galaxies, of which two were previously uncataloged and one did not have a known redshift. No H I emission was detected from the vicinity of the two absorbers, which are located in a void and a region of very low galaxy density; but the limits are somewhat less stringent than for the other sight lines. These results are similar to what has been found in optically unbiased H I surveys. Thus, presence of Ly-alpha absorbers does not significantly alter the H I detection rate in their environment.

IUE observations of hydrogen and deuterium in the local interstellar medium

NASA Technical Reports Server (NTRS)

Murthy, J.; Henry, R. C.; Moos, H. W.; Landsman, W. B.; Linsky, J. L.

1987-01-01

High-resolution Ly-alpha spectra of the late-type stars Epsilon Eri, Procyon, Altair, Capella, and HR 1099 taken with the short-wavelength camera on IUE are presented. The density, velocity dispersion, and bulk velocity of the interstellar H I toward each of the stars is derived from the spectra. Lower limits on the deuterium-to-hydrogen ratio toward these stars are obtained.

Modelling of Lyman-alpha emitting galaxies and ionized bubbles at the epoch of reionization

NASA Astrophysics Data System (ADS)

Yajima, Hidenobu; Sugimura, Kazuyuki; Hasegawa, Kenji

2018-07-01

Understanding {Ly{α}} emitting galaxies (LAEs) can be a key to reveal cosmic reionization and galaxy formation in the early Universe. Based on halo merger trees and {Ly{α}} radiation transfer calculations, we model redshift evolution of LAEs and their observational properties at z ≥ 6. We consider ionized bubbles associated with individual LAEs and IGM (integer-galactic medium) transmission of {Ly{α}} photons. We find that {Ly{α}} luminosity tightly correlates with halo mass and stellar mass, while the relation with star formation rate has a large dispersion. Comparing our models with the observed luminosity function by Konno et al., we suggest that LAEs at z ˜ 7 have galactic wind of V_out ≳ 100 km s^{-1} and H I column density of N_HI ≳ 10^{20} cm^{-2}. Number density of bright LAEs rapidly decreases as redshift increases, due to both lower star formation rate and smaller H II bubbles. Our model predicts future wide deep surveys with next-generation telescopes, such as James Webb Space Telescope, European Extremely Large Telescope, and Thirty Metre Telescope, can detect LAEs at z ˜ 10 with a number density of n_LAE ˜ {a few } × 10^{-6} Mpc^{-3} for the flux sensitivity of 10^{-18} erg cm^{-2} s^{-1}. When giant H II bubbles are formed by clustering LAEs, the number density of observable LAEs can increase by a factor of few. By combining these surveys with future 21-cm observations, it could be possible to detect both LAEs with L_{Lyα }≳ 10^{42} erg s^{-1} and their associated giant H II bubbles with the size {≳ } 250 kpc at z ˜ 10.

Modelling of Lyman-alpha emitting galaxies and ionized bubbles at the epoch of reionization

NASA Astrophysics Data System (ADS)

Yajima, Hidenobu; Sugimura, Kazuyuki; Hasegawa, Kenji

2018-04-01

Understanding {Ly{α }} emitting galaxies (LAEs) can be a key to reveal cosmic reionization and galaxy formation in the early Universe. Based on halo merger trees and {Ly{α }} radiation transfer calculations, we model redshift evolution of LAEs and their observational properties at z ≥ 6. We consider ionized bubbles associated with individual LAEs and IGM transmission of {Ly{α }} photons. We find that {Ly{α }} luminosity tightly correlates with halo mass and stellar mass, while the relation with star formation rate has a large dispersion. Comparing our models with the observed luminosity function by Konno et al., we suggest that LAEs at z ˜ 7 have galactic wind of V_out ≳ 100 km s^{-1} and HI column density of N_HI ≳ 10^{20} cm^{-2}. Number density of bright LAEs rapidly decreases as redshift increases, due to both lower star formation rate and smaller HII bubbles. Our model predicts future wide deep surveys with next generation telescopes, such as JWST, E-ELT and TMT, can detect LAEs at z ˜ 10 with a number density of n_LAE ˜ a few × 10^{-6} Mpc^{-3} for the flux sensitivity of 10^{-18} erg cm^{-2} s^{-1}. When giant HII bubbles are formed by clustering LAEs, the number density of observable LAEs can increase by a factor of few. By combining these surveys with future 21-cm observations, it could be possible to detect both LAEs with L_{Lyα }≳ 10^{42} erg s^{-1} and their associated giant HII bubbles with the size ≳ 250 kpc at z ˜ 10.

The Role of Galaxies and AGN in Reionising the IGM - slowromancapi@: Keck Spectroscopy of 5 < z < 7 Galaxies in the QSO Field J1148+5251

NASA Astrophysics Data System (ADS)

Kakiichi, Koki; Ellis, Richard S.; Laporte, Nicolas; Zitrin, Adi; Eilers, Anna-Christina; Ryan-Weber, Emma; Meyer, Romain A.; Robertson, Brant; Stark, Daniel P.; Bosman, Sarah E. I.

2018-05-01

We introduce a new method for determining the influence of galaxies and active galactic nuclei (AGN) on the intergalactic medium (IGM) at high redshift and illustrate its potential via a first application to the field of the z = 6.42 QSO J1148+5251. Correlating spatial positions Lyman break galaxies (LBGs) with the Lyman alpha forest seen in the spectrum of a background QSO, we provide a statistical measure of the typical escape fraction of Lyman continuum photons. Using Keck DEIMOS spectroscopy to locate 7 colour-selected LBGs in the range 5.3 ≲ z ≲ 6.4 we examine the spatial correlation between this sample and Lyα/Lyβ transmission fluctuations in a Keck ESI spectrum of the QSO. Interpreting the statistical H I proximity effect as arising from faint galaxies clustered around the LBGs, we translate the observed mean Lyα transmitted flux into a constraint on the mean escape fraction ⟨fesc⟩ ≥ 0.08 at z ≃ 6. We also report individual transverse H I proximity effect for a z = 6.177 luminous LBG via a Lyβ transmission spike and two broad Lyα transmission spikes around the z = 5.701 AGN. We discuss the origin of such associations which suggest that while faint galaxies are primarily driving reionisation, luminous galaxies and AGN may provide important contributions to the UV background or thermal fluctuations of the IGM at z ≃ 6. Although a limited sample, our results demonstrate the potential of making progress using this method in resolving one of the most challenging aspects of the contribution of galaxies and AGN to cosmic reionisation.

Akt/protein kinase B activation by adenovirus vectors contributes to NFkappaB-dependent CXCL10 expression.

PubMed

Liu, Qiang; White, Lindsay R; Clark, Sharon A; Heffner, Daniel J; Winston, Brent W; Tibbles, Lee Anne; Muruve, Daniel A

2005-12-01

In gene therapy, the innate immune system is a significant barrier to the effective application of adenovirus (Ad) vectors. In kidney epithelium-derived (REC) cells, serotype 5 Ad vectors induce the expression of the chemokine CXCL10 (IP-10), a response that is dependent on NFkappaB. Compared to the parental vector AdLuc, transduction with the RGD-deleted vector AdL.PB resulted in reduced CXCL10 activation despite increasing titers, implying that RGD-alpha(V) integrin interactions contribute to adenovirus induction of inflammatory genes. Akt, a downstream effector of integrin signaling, was activated within 10 min of transduction with Ad vectors in a dose-dependent manner. Akt activation was not present following transduction with AdL.PB, confirming the importance of capsid-alpha(V) integrin interactions in Ad vector Akt activation. Inhibition of the phosphoinositide-3-OH kinase/Akt pathway by Wortmannin or Ly294002 compounds decreased Ad vector induction of CXCL10 mRNA. Similarly, adenovirus-mediated overexpression of the dominant negative AktAAA decreased CXCL10 mRNA expression compared to the reporter vector AdLacZ alone. The effect of Akt on CXCL10 mRNA expression occurred via NFkappaB-dependent transcriptional activation, since AktAAA overexpression and Ly294002 both inhibited CXCL10 and NFkappaB promoter activation in luciferase reporter experiments. These results show that Akt plays a role in the Ad vector activation of NFkappaB and CXCL10 expression. Understanding the mechanism underlying the regulation of host immunomodulatory genes by adenovirus vectors will lead to strategies that will improve the efficacy and safety of these agents for clinical use.

Ada Compiler Validation Summary Report: Certificate Number: 940325S1. 11341 DDC-I, DACS Sun SPARC/SunOS to 80186 Bare Ada Cross Compiler System, Version 4.6.4 Sun SPARCstation IPX = Intel iSBC 186/100 (Bare Machine)

DTIC Science & Technology

1994-03-25

declarations requiring more digits than SYSTEM.MAXDIGITS: C24113L..Y (14 tests) C35705L..Y (14 tests) C35706L..Y (14 tests) C35707L..Y (14 tests) 2-1...before the DACS Run-Time System (RMs) libary normally searches for na-4ime routin;, in this way one can replace the standard DACS RTS routines with...SHORTINTEGER is range -128 .. 127; type INTEGER is range -32_768 .. 32_767; type LONGINTEGER is range -2147_483_648 .. 2_147_483_647; type FLOAT is digits 6

Directly Imaging Damped Ly-Alpha Galaxies at Redshifts Greater Than 2. III: The Star Formation Rates of Neutral Gas Reservoirs at Redshifts of Approximately 2.7

NASA Technical Reports Server (NTRS)

Fumagalli, Michele; OMeara, John M.; Prochaska, J. Xavier; Rafelski, Marc; Kanekar, Nissim

2014-01-01

We present results from a survey designed to probe the star formation properties of 32 damped Ly alpha systems (DLAs) at redshifts of approximately 2.7. By using the "double-DLA" technique that eliminates the glare of the bright background quasars, we directly measure the rest-frame FUV flux from DLAs and their neighbouring galaxies. At the position of the absorbing gas, we place stringent constraints on the unobscured star formation rates (SFRs) of DLAs to 2 sigma limits of psi less than 0.09-0.27 solar mass yr(exp -1), corresponding to SFR surface densities sigma(sub sfr) less than 10(exp -2.6)-10(exp -1.5) solar mass yr(exp -1) kpc(exp -2). The implications of these limits for the star formation law, metal enrichment, and cooling rates of DLAs are examined. By studying the distribution of impact parameters as a function of SFRs for all the galaxies detected around these DLAs, we place new direct constraints on the bright end of the UV luminosity function of DLA hosts. We find that less than or equal to 13% of the hosts have psi greater than or equal to 2 solar mass yr(exp -1) at impact parameters b(sub dla) less than or equal to (psi/solar mass yr(exp -1))(exp 0.8) + 6 kpc, differently from current samples of confirmed DLA galaxies. Our observations also disfavor a scenario in which the majority of DLAs arise from bright LBGs at distances 20 less than or equal to b(sub dla) less than 100 kpc. These new findings corroborate a picture in which DLAs do not originate from highly star forming systems that are coincident with the absorbers, and instead suggest that DLAs are associated with faint, possibly isolated, star-forming galaxies. Potential shortcomings of this scenario and future strategies for further investigation are discussed.

IUE observations of interstellar hydrogen and deuterium toward Alpha Centauri B

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Murthy, J.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1986-01-01

A high dispersion profile is presented of the Lyman-alpha emission toward Alpha Cen B as recorded in two images taken with the IUE spacecraft. The spectra were examined with a three-parameter Gaussian or five-parameter solar-type profile to derive the intrinsic background stellar emission. Voight absorption profiles were calculated for the intervening H I and D I gas. A uniform, thermally broadened medium was assumed, with the calculations being based on the free stellar parameters of density, velocity dispersion and the bulk velocity of H I, and the density of D I. The use of a small aperture is shown to have been effective in eliminating geocoronal and interplanetary diffuse Ly-alpha contamination. The H I absorption profile toward Alpha Cen B is found to be equivalent to that toward Alpha Cen A, indicating that the H I profiles derived are essentially independent of stellar emission. Less success, however, was attained in obtaining any definitive D I profile, although an asymmetry in the blue and red wings of the Lyman-alpha emissions did show the presence of absorption by interstellar deuterium and allow setting a lower limit of 0.00001 for the D I/H I ratio.

Lyman Alpha Camera for Io's SO2 atmosphere and Europa's water plumes

NASA Astrophysics Data System (ADS)

McEwen, Alfred S.; Sandel, Bill; Schneider, Nick

2014-05-01

The Student Lyman-Alpha Mapper (SLAM) was conceived for the Io Volcano Observer (IVO) mission proposal (McEwen et al., 2014) to determine the spatial and temporal variations in Io's SO2 atmosphere by recording the H Ly-α reflection over the disk (Feldman et al., 2000; Feaga et al., 2009). SO2 absorbs at H Ly-α, thereby modulating the brightness of sunlight reflected by the surface, and measures the density of the SO2 atmosphere and its variability with volcanic activity and time of day. Recently, enhancements at the Ly-α wavelength (121.57 nm) were seen near the limb of Europa and interpreted as active water plumes ~200 km high (Roth et al., 2014). We have a preliminary design for a very simple camera to image in a single bandpass at Ly-α, analogous to a simplified version of IMAGE EUV (Sandel et al. 2000). Our goal is at least 50 resolution elements across Io and/or Europa (~75 km/pixel), ~3x better than HST STIS, to be acquired at a range where the radiation noise is below 1E-4 hits/pixel/s. This goal is achieved with a Cassegrain-like telescope with a 10-cm aperture. The wavelength selection is achieved using a simple self-filtering mirror in combination with a solar-blind photocathode. A photon-counting detector based on a sealed image intensifier preserves the poisson statistics of the incoming photon flux. The intensifier window is coated with a solar-blind photocathode material (CsI). The location of each photon event is recorded by a position-sensitive anode based on crossed delay-line or wedge-and-strip technology. The sensitivity is 0.01 counts/pixel/sec/R, sufficient to estimate SO2 column abundances ranging from 1E15 to 1E17 per cm2 in a 5 min (300 sec) exposure. Sensitivity requirements to search for and image Europa plumes may be similar. Io's Ly-α brightness of ~3 kR exceeds the 0.8 kR brightness of Europa's plume reported by Roth et al. (2014), but the plume brightness is a direct measurement rather than inferring column abundance from absorption. Also, the radiation-induced noise is lower at Europa, permitting longer exposure times and imaging at closer range. This is a very simple instrument with no moving parts, a mass of 4 kg (plus 1.7 kg radiation shielding), and it needs 4 W power. It has no special accommodation requirements and would simply collect data in ride-along mode during point-and-stare sequences. Feaga, L.M., et al. (2009) Io's dayside SO2 atmosphere, Icarus 201, 570-584 (2009). Feldman, P.D., et al., (2000) Lyman-α imaging of the SO2 distribution on Io, Geophys. Res. Lett., 27, 1787-1790. McEwen, A.S. et al. (2014) Io Volcano Observer (IVO): Budget travel to the outer Solar System. Acta Astronautica 93, 539-544. Roth, L. et al. (2014) Transient water vapor at Europa's south pole. Science 343, 171. Sandel, B., et al. (2000) The Extreme Ultraviolet Imager investigation for the IMAGE mission. Space Sci. Rev. 91, 197-242.

Survey parameters for detecting 21cm - Lyα emitter cross correlations with the Square Kilometre Array

NASA Astrophysics Data System (ADS)

Hutter, Anne; Trott, Cathryn M.; Dayal, Pratika

2018-06-01

Detections of the cross correlation signal between the 21cm signal during reionization and high-redshift Lyman Alpha emitters (LAEs) are subject to observational uncertainties which mainly include systematics associated with radio interferometers and LAE selection. These uncertainties can be reduced by increasing the survey volume and/or the survey luminosity limit, i.e. the faintest detectable Lyman Alpha (Lyα) luminosity. We use our model of high-redshift LAEs and the underlying reionization state to compute the uncertainties of the 21cm-LAE cross correlation function at z ≃ 6.6 for observations with SKA1-Low and LAE surveys with Δz = 0.1 for three different values of the average IGM ionization state (⟨χHI⟩≃ 0.1, 0.25, 0.5). At z ≃ 6.6, we find SILVERRUSH type surveys, with a field of view of 21 deg2 and survey luminosity limits of Lα ≥ 7.9 × 1042erg s-1, to be optimal to distinguish between an inter-galactic medium (IGM) that is 50%, 25% and 10% neutral, while surveys with smaller fields of view and lower survey luminosity limits, such as the 5 and 10 deg2 surveys with WFIRST, can only discriminate between a 50% and 10% neutral IGM.

Single isotope fractionation of (16)O(-) implications for early history of solar system

NASA Technical Reports Server (NTRS)

Arrhenius, G.

1980-01-01

Chemical fractionation processes are investigated with emphasis on selective single isotope fractionation in polyisotopic systems, particularly in oxygen. The related temperature parameters of meteoritic condensates and of their source medium are investigated by a thermometric method that is independent of assumptions regarding temperatures and pressures in the solar nebula. The crucial nonlinear chemical fractionation of O-16 was demonstrated experimentally. The effect was achieved in condensed CO2 formed from CO with C-12 O-16 selectively excited by H Ly alpha. The effect was verified by mass spectrometric measurements. The meteorite paleotemperature estimates were advanced from defining only thermal exposure to evaluating time and temperature independently. Grain temperatures at condensation of refractory inclusion materials are indicated to be less than 900 K in agreement with radiation temperature considerations and observations in circumstellar dust shells.

Lee-Yang Polynomials and Ground States of Spin Systems

NASA Astrophysics Data System (ADS)

Slawny, Joseph

2014-08-01

We obtain two kinds of results on the region in the space of the interactions of lattice systems where the Lee-Yang property holds (LY domain). First we show that the LY domain is related to interactions with exactly two ground states. Then we give a description of the full LY domain of an extended "plaquette model" analyzed by Lebowitz and Ruelle (Commun Math Phys 304:711-722, 2011). This allows us to prove a permanence property of the system, which we conjecture to hold in general.

Resolved spectroscopy of adolescent and infant galaxies (1 < z < 10)

NASA Astrophysics Data System (ADS)

Wright, Shelley; IRIS Science Team

2014-07-01

The combination of integral field spectroscopy (IFS) and adaptive optics (AO) on TMT will be revolutionary in studying the distant universe. The high angular resolution exploited by an AO system with this large aperture will be essential for studying high-redshift (1 < z < 5) galaxies' kinematics and chemical abundance histories. At even greater distances, TMT will be essential for conducting follow-up spectroscopy of Ly-alpha emission from first lights galaxies (6 < z < 10) and determining their kinematics and morphologies. I will present simulations and sensitivity calculations for high-z and first light galaxies using the diffraction-limited instrument IRIS coupled with NFIRAOS. I will put these simulations in context with current IFS+AO high-z observations and future capabilities with JWST.

Frequency and Risk Factors for Associated Lymphomas in Patients With Lymphomatoid Papulosis

PubMed Central

Tressières, Benoît; D’Incan, Michel; Machet, Laurent; Grange, Florent; Estève, Éric; Dalac, Sophie; Ingen-Housz-Oro, Saskia; Bagot, Martine; Beylot-Barry, Marie; Joly, Pascal

2016-01-01

Background. Lymphomatoid papulosis (LyP) is classified as an indolent cutaneous lymphoma, but outcome dramatically worsens if LyP is associated with lymphoma. The frequency of this association remains unclear in the literature. Here, we assess the frequency and risk factors of association between LyP and another lymphoma in an 11-year retrospective study conducted in 8 dermatology departments belonging to the French Study Group on Cutaneous Lymphoma (FSGCL). Patients and Methods. Patients with LyP were identified and data extracted from the FSGCL registry between 1991 and 2006. Patients were followed up to January 2014. Age, sex, number of skin lesions, histologic subtype, and genotype were recorded at baseline. Risk factors were determined using univariate and multivariate analysis. Cumulative probability of association was calculated using the Kaplan-Meier method. Results. We observed 52 cases of lymphomas (cutaneous, n = 38; systemic, n = 14) in 44 of 106 patients (41%). Lymphoma diagnosis was concomitant with or prior to LyP diagnosis in 31 cases and occurred during the course of LyP in 21 cases (cutaneous, n = 14; systemic, n = 7; median delay: 5 years; interquartile range: 1.5–7 years). In multivariate analysis, main prognostic factors for association between LyP and another lymphoma were older age (odds ratio [OR]: 1.05 per year; 95% confidence interval [CI]: 1.01–1.08; p = .011) and presence of a T-cell clone in LyP lesions (OR: 7.55; 95% CI: 2.18–26.18; p = .001). Conclusion. Older age and presence of a T-cell clone in LyP lesions are risk factors for associated lymphomas in patients with LyP. These findings should help to identify patients who require close management in clinical practice. Implications for Practice: The management of lymphomatoid papulosis (LyP) is that of an indolent cutaneous lymphoma, based on its excellent prognosis. However, this good prognosis is altered if LyP is associated with lymphoma. Furthermore, risk factors for and frequency of this association remain unclear in the literature. The results presented here demonstrate a high rate of association between LyP and other lymphomas (41%) as well as a long median delay of occurrence (5 years), which emphasizes the need for prolonged follow-up of patients with LyP. Moreover, two main risk factors (i.e., older age and presence of a T-cell clone in LyP lesions) are highlighted, which should help clinical practitioners to identify patients who require close management. PMID:26668250

THE ALFALFA H I ABSORPTION PILOT SURVEY: A WIDE-AREA BLIND DAMPED Ly{alpha} SYSTEM SURVEY OF THE LOCAL UNIVERSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darling, Jeremy; Macdonald, Erin P.; Haynes, Martha P.

2011-11-20

We present the results of a pilot survey for neutral hydrogen (H I) 21 cm absorption in the Arecibo Legacy Fast Arecibo L-Band Feed Array (ALFALFA) Survey. This project is a wide-area 'blind' search for H I absorption in the local universe, spanning -650 km s{sup -1} < cz < 17, 500 km s{sup -1} and covering 517.0 deg{sup 2} (7% of the full ALFALFA survey). The survey is sensitive to H I absorption lines stronger than 7.7 mJy (8983 radio sources) and is 90% complete for lines stronger than 11.0 mJy (7296 sources). The total redshift interval sensitive tomore » all damped Ly{alpha} (DLA) systems (N{sub H{sub i}}{>=}2 Multiplication-Sign 10{sup 20} cm{sup -2}) is {Delta}z = 7.0 (129 objects, assuming T{sub s} = 100 K and covering fraction unity); for super-DLAs (N{sub H{sub i}}{>=}2 Multiplication-Sign 10{sup 21} cm{sup -2}) it is {Delta}z = 128.2 (2353 objects). We re-detect the intrinsic H I absorption line in UGC 6081 but detect no intervening absorption line systems. We compute a 95% confidence upper limit on the column density frequency distribution function f(N{sub H{sub i}},X) spanning four orders of magnitude in column density, 10{sup 19} (T{sub s} /100 K) (1/f) cm{sup -2}

VizieR Online Data Catalog: Census of QSOs Narrow Absorption Lines (Misawa+, 2007)

NASA Astrophysics Data System (ADS)

Misawa, T.; Charlton, J. C.; Eracleous, M.; Ganguly, R.; Tytler, D.; Kirkman, D.; Suzuki, N.; Lubin, D.

2009-04-01

The quasars in our sample were originally selected and observed in a survey aimed at measuring the deuterium-to-hydrogen abundance ratio (D/H) in the Ly{alpha} forest. The observations were carried out with Keck HIRES through a 1.14" slit resulting in a velocity resolution of ~8km/s (FWHM). The spectra were extracted by the automated program, MAKEE, written by Tom Barlow. (2 data files).

Activation of PKC isoform beta(I) at the blood-brain barrier rapidly decreases P-glycoprotein activity and enhances drug delivery to the brain.

PubMed

Rigor, Robert R; Hawkins, Brian T; Miller, David S

2010-07-01

P-glycoprotein is an ATP (adenosine triphosphate)-driven drug efflux transporter that is highly expressed at the blood-brain barrier (BBB) and is a major obstacle to the pharmacotherapy of central nervous system diseases, including brain tumors, neuro-AIDS, and epilepsy. Previous studies have shown that P-glycoprotein transport activity in rat brain capillaries is rapidly reduced by the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha) acting through protein kinase C (PKC)-dependent signaling. In this study, we used isolated rat brain capillaries to show that the TNF-alpha-induced reduction of P-glycoprotein activity was prevented by a PKCbeta(I/II) inhibitor, LY333531, and mimicked by a PKCbeta(I/II) activator, 12-deoxyphorbol-13-phenylacetate-20-acetate (dPPA). Western blotting of brain capillary extracts with phospho-specific antibodies showed that dPPA activated PKCbeta(I), but not PKCbeta(II). Moreover, in intact rats, intracarotid infusion of dPPA potently increased brain accumulation of the P-glycoprotein substrate, [(3)H]-verapamil without compromising tight junction integrity. Thus, PKCbeta(I) activation selectively reduced P-glycoprotein activity both in vitro and in vivo. Targeting PKCbeta(I) at the BBB may prove to be an effective strategy for enhancing the delivery of small molecule therapeutics to the brain.

alpha1B-Adrenergic receptor phosphorylation and desensitization induced by transforming growth factor-beta.

PubMed Central

Romero-Avila, M Teresa; Flores-Jasso, C Fabián; García-Sáinz, J Adolfo

2002-01-01

Transforming growth factor-beta (TGF-beta) induced alpha(1B)-adrenergic receptor phosphorylation in Rat-1 fibroblasts stably expressing these adrenoceptors. This effect of TGF-beta was rapid, reaching a maximum within 30 min and decreasing thereafter, and concentration-dependent (EC(50) 0.3 pM). The phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and the protein kinase C inhibitors staurosporine, Ro 318220 and bisindolylmaleimide, blocked the effect of this growth factor. alpha(1B)-Adrenergic receptor phosphorylation was associated with desensitization, as indicated by a reduction in the adrenergic-mediated production of [(3)H]inositol phosphates. Phosphorylation of alpha(1B)-adrenergic receptors by TGF-beta was also observed in Cos-1 cells transfected with the receptor. Co-transfection of the dominant-negative mutant of the regulatory subunit of phosphoinositide 3-kinase (Deltap85) inhibited the phosphorylation of alpha(1B)-adrenergic receptors induced by TGF-beta. Our results indicate that activation of TGF-beta receptors induces alpha(1B)-adrenergic receptor phosphorylation and desensitization. The data suggest that phosphoinositide 3-kinase and protein kinase C play key roles in this effect of TGF-beta. PMID:12234252

alpha1B-Adrenergic receptor phosphorylation and desensitization induced by transforming growth factor-beta.

PubMed

Romero-Avila, M Teresa; Flores-Jasso, C Fabián; García-Sáinz, J Adolfo

2002-12-01

Transforming growth factor-beta (TGF-beta) induced alpha(1B)-adrenergic receptor phosphorylation in Rat-1 fibroblasts stably expressing these adrenoceptors. This effect of TGF-beta was rapid, reaching a maximum within 30 min and decreasing thereafter, and concentration-dependent (EC(50) 0.3 pM). The phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and the protein kinase C inhibitors staurosporine, Ro 318220 and bisindolylmaleimide, blocked the effect of this growth factor. alpha(1B)-Adrenergic receptor phosphorylation was associated with desensitization, as indicated by a reduction in the adrenergic-mediated production of [(3)H]inositol phosphates. Phosphorylation of alpha(1B)-adrenergic receptors by TGF-beta was also observed in Cos-1 cells transfected with the receptor. Co-transfection of the dominant-negative mutant of the regulatory subunit of phosphoinositide 3-kinase (Deltap85) inhibited the phosphorylation of alpha(1B)-adrenergic receptors induced by TGF-beta. Our results indicate that activation of TGF-beta receptors induces alpha(1B)-adrenergic receptor phosphorylation and desensitization. The data suggest that phosphoinositide 3-kinase and protein kinase C play key roles in this effect of TGF-beta.

Superoxide differentially controls pulmonary and systemic vascular tone through multiple signalling pathways

PubMed Central

Snetkov, Vladimir A.; Smirnov, Sergey V.; Kua, Justin; Aaronson, Philip I.; Ward, Jeremy P.T.; Knock, Greg A.

2011-01-01

Aims The aim of this study was to determine the relative importance of Ca2+ sensitization, ion channels, and intracellular Ca2+ ([Ca2+]i) in the mixed constrictor/relaxation actions of superoxide anion on systemic and pulmonary arteries. Methods and results Pulmonary and mesenteric arteries were obtained from rat. Superoxide was generated in arteries and cells with 6-anilino-5,8-quinolinequinone (LY83583). Following pre-constriction with U46619, 10 μmol/L LY83583 caused constriction in pulmonary and relaxation in mesenteric arteries. Both constrictor and relaxant actions of LY83583 were inhibited by superoxide dismutase and catalase. LY83583 caused Rho-kinase-dependent constriction in α-toxin-permeabilized pulmonary but not mesenteric arteries. Phosphorylation of myosin phosphatase-targeting subunit-1 (MYPT-1; as determined by western blot), was enhanced by LY83583 in pulmonary artery only. However, in both artery types, changes in tension were closely correlated with changes in phosphorylation of the 20 kDa myosin light chain as well as changes in [Ca2+]i (as measured with Fura PE-3), with LY83583 causing increases in pulmonary and decreases in mesenteric arteries. When U46619 was replaced by 30 mmol/L K+, all changes in [Ca2+]i were abolished and LY83583 constricted both artery types. The KV channel inhibitor 4-aminopyridine abolished the LY83583-induced relaxation in mesenteric artery without affecting constriction in pulmonary artery. However, LY83583 caused a similar hyperpolarizing shift in the steady-state activation of KV current in isolated smooth muscle cells of both artery types. Conclusions Superoxide only causes Rho-kinase-dependent Ca2+ sensitization in pulmonary artery, resulting in constriction, and whilst it opens KV channels in both artery types, this only results in relaxation in mesenteric. PMID:20805095

A Novel Nociceptin Receptor Antagonist LY2940094 Inhibits Excessive Feeding Behavior in Rodents: A Possible Mechanism for the Treatment of Binge Eating Disorder.

PubMed

Statnick, Michael A; Chen, Yanyun; Ansonoff, Michael; Witkin, Jeffrey M; Rorick-Kehn, Linda; Suter, Todd M; Song, Min; Hu, Charlie; Lafuente, Celia; Jiménez, Alma; Benito, Ana; Diaz, Nuria; Martínez-Grau, Maria Angeles; Toledo, Miguel A; Pintar, John E

2016-02-01

Nociceptin/orphanin FQ (N/OFQ), a 17 amino acid peptide, is the endogenous ligand of the ORL1/nociceptin-opioid-peptide (NOP) receptor. N/OFQ appears to regulate a variety of physiologic functions including stimulating feeding behavior. Recently, a new class of thienospiro-piperidine-based NOP antagonists was described. One of these molecules, LY2940094 has been identified as a potent and selective NOP antagonist that exhibited activity in the central nervous system. Herein, we examined the effects of LY2940094 on feeding in a variety of behavioral models. Fasting-induced feeding was inhibited by LY2940094 in mice, an effect that was absent in NOP receptor knockout mice. Moreover, NOP receptor knockout mice exhibited a baseline phenotype of reduced fasting-induced feeding, relative to wild-type littermate controls. In lean rats, LY2940094 inhibited the overconsumption of a palatable high-energy diet, reducing caloric intake to control chow levels. In dietary-induced obese rats, LY2940094 inhibited feeding and body weight regain induced by a 30% daily caloric restriction. Last, in dietary-induced obese mice, LY2940094 decreased 24-hour intake of a high-energy diet made freely available. These are the first data demonstrating that a systemically administered NOP receptor antagonist can reduce feeding behavior and body weight in rodents. Moreover, the hypophagic effect of LY2940094 is NOP receptor dependent and not due to off-target or aversive effects. Thus, LY2940094 may be useful in treating disorders of appetitive behavior such as binge eating disorder, food choice, and overeating, which lead to obesity and its associated medical complications and morbidity. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Alpha-2 adrenergic activity of bromocriptine and quinpirole in chicken pineal gland. Effects on melatonin synthesis and ( sup 3 H)rauwolscine binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zawilska, J.; Iuvone, P.M.

In the pineal gland and retina of chickens, serotonin N-acetyl-transferase (NAT) activity and melatonin content are modulated by different receptors, alpha-2 adrenergic receptors in pineal gland and D2-dopamine receptors in retina. The effect of two D2-dopamine receptor agonists, bromocriptine and quinpirole (LY 171555), on melatonin synthesis in these tissues was investigated. Systemic administrations of bromocriptine and quinpirole decreased nocturnal NAT activity and melatonin content of both pineal gland and retina. Bromocriptine was equipotent in the two tissues, whereas quinpirole was approximately 100-fold more potent in retina than in pineal gland. In pineal gland, the suppressive effects of bromocriptine and quinpirolemore » on NAT activity were blocked by yohimbine, a selective alpha-2 adrenergic receptor antagonist, but not by spiperone, a D2-dopamine receptor antagonist. In contrast, bromocriptine- and quinpirole-induced decreases of the enzyme activity in retina were antagonized by spiperone, and not affected by yohimbine. The nocturnal increase of NAT activity of pineal glands in vitro was inhibited with an order of potency clonidine greater than bromocriptine greater than quinpirole. Additionally, bromocriptine and quinpirole displaced the specific binding of (3H)rauwolscine, an alpha-2 adrenergic receptor antagonist, to membranes from chicken pineal gland, with potencies comparable to those observed for inhibition of NAT activity in vitro. It is suggested that bromocriptine and quinpirole, in addition to their D2-dopaminergic activity, can stimulate alpha-2 adrenergic receptors in pineal gland of chicken.« less

Frontline Science: Proliferation of Ly6C+ monocytes during urinary tract infections is regulated by IL-6 trans-signaling.

PubMed

Dixit, Akanksha; Bottek, Jenny; Beerlage, Anna-Lena; Schuettpelz, Jana; Thiebes, Stephanie; Brenzel, Alexandra; Garbers, Christoph; Rose-John, Stefan; Mittrücker, Hans-Willi; Squire, Anthony; Engel, Daniel R

2018-01-01

Ly6C + monocytes are important components of the innate immune defense against infections. These cells have been shown to proliferate in the bone marrow of mice with systemic infections. However, the proliferative capacity of Ly6C + monocytes in infected peripheral tissues as well as the associated regulatory mechanisms remain unclear. In this study, we analyzed the proliferative capacity of Ly6C + monocytes in the urinary bladder after infection with uropathogenic E. coli, one of the most prevalent pathogen worldwide, and in LPS-induced peritonitis. We show that Ly6C + monocytes proliferated in the bladder after infection with uropathogenic E. coli and in the peritoneum after intraperitoneal injection of LPS. We identified IL-6, a molecule that is highly expressed in infections, as a crucial regulator of Ly6C + monocyte proliferation. Inhibition of IL-6 via administration of antibodies against IL-6 or gp130 impeded Ly6C + monocyte proliferation. Furthermore, repression of IL-6 trans-signaling via administration of soluble gp130 markedly reduced the proliferation of Ly6C + monocytes. Overall, this study describes the proliferation of Ly6C + monocytes using models of urinary tract infection and LPS-induced peritonitis. IL-6 trans-signaling was identified as the regulator of Ly6C + monocyte proliferation. ©2017 Society for Leukocyte Biology.

Id-1 activation of PI3K/Akt/NFkappaB signaling pathway and its significance in promoting survival of esophageal cancer cells.

PubMed

Li, Bin; Cheung, Pak Yan; Wang, Xianghong; Tsao, Sai Wah; Ling, Ming Tat; Wong, Yong Chuan; Cheung, Annie L M

2007-11-01

Inhibitor of differentiation or DNA binding (Id-1) is a helix-loop-helix protein that is over-expressed in many types of cancer including esophageal cancer. This study aims to investigate its effects on the phosphatidylinositol-3-kinase (PI3K)/Akt/ nuclear factor kappa B (NFkappaB) signaling pathway and the significance in protecting esophageal cancer cells against apoptosis. We found elevated expression of phosphorylated forms of Akt, glycogen synthase kinase 3beta and inhibitor of kappa B, as well as increased nuclear translocation of NFkappaB subunit p65 and NFkappaB DNA-binding activity, in esophageal cancer cells with stable ectopic Id-1 expression. Transient transfection of Id-1 into HEK293 cells confirmed activation of PI3K/Akt/NFkappaB signaling and the effects were counteracted by the PI3K inhibitor LY294002. Treatment with tumor necrosis factor-alpha (TNF-alpha) elicited a significantly weaker apoptotic response, following a marked and sustained activation of Akt and NFkappaB in the Id-1-over-expressing cells, compared with the vector control. The effects of Id-1 on the PI3K/Akt/NFkappaB signaling pathway and apoptosis were reversed in esophageal cancer cells transfected with siRNA against Id-1. In addition, inhibition of PI3K or NFkappaB signaling using the PI3K inhibitor LY294002 or the NFkappaB inhibitor Bay11-7082 increased the sensitivity of Id-1-over-expressing esophageal cancer cells to TNF-alpha-induced apoptosis. Our results provide the first evidence that Id-1 induces the activation of PI3K/Akt/NFkappaB signaling pathway, and protects esophageal cancer cells from TNF-alpha-induced apoptosis in vitro. Inactivation of Id-1 may provide us with a novel strategy to improve the treatment and survival of patients with esophageal cancer.

Comparison of Solar Fine Structure Observed Simultaneously in Lyα and Mg II h

NASA Astrophysics Data System (ADS)

Schmit, D.; Sukhorukov, A. V.; De Pontieu, B.; Leenaarts, J.; Bethge, C.; Winebarger, A.; Auchère, F.; Bando, T.; Ishikawa, R.; Kano, R.; Kobayashi, K.; Narukage, N.; Trujillo Bueno, J.

2017-10-01

The Chromospheric Lyman Alpha Spectropolarimeter (CLASP) observed the Sun in H I Lyα during a suborbital rocket flight on 2015 September 3. The Interface Region Imaging Telescope (IRIS) coordinated with the CLASP observations and recorded nearly simultaneous and co-spatial observations in the Mg II h and k lines. The Mg II h and Lyα lines are important transitions, energetically and diagnostically, in the chromosphere. The canonical solar atmosphere model predicts that these lines form in close proximity to each other and so we expect that the line profiles will exhibit similar variability. In this analysis, we present these coordinated observations and discuss how the two profiles compare over a region of quiet Sun at viewing angles that approach the limb. In addition to the observations, we synthesize both line profiles using a 3D radiation-MHD simulation. In the observations, we find that the peak width and the peak intensities are well correlated between the lines. For the simulation, we do not find the same relationship. We have attempted to mitigate the instrumental differences between IRIS and CLASP and to reproduce the instrumental factors in the synthetic profiles. The model indicates that formation heights of the lines differ in a somewhat regular fashion related to magnetic geometry. This variation explains to some degree the lack of correlation, observed and synthesized, between Mg II and Lyα. Our analysis will aid in the definition of future observatories that aim to link dynamics in the chromosphere and transition region.

Comparison of Solar Fine Structure Observed Simultaneously in Ly α and Mg ii h

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmit, D.; Sukhorukov, A. V.; Leenaarts, J.

The Chromospheric Lyman Alpha Spectropolarimeter (CLASP) observed the Sun in H i Ly α during a suborbital rocket flight on 2015 September 3. The Interface Region Imaging Telescope ( IRIS ) coordinated with the CLASP observations and recorded nearly simultaneous and co-spatial observations in the Mg ii h and k lines. The Mg ii h and Ly α lines are important transitions, energetically and diagnostically, in the chromosphere. The canonical solar atmosphere model predicts that these lines form in close proximity to each other and so we expect that the line profiles will exhibit similar variability. In this analysis, wemore » present these coordinated observations and discuss how the two profiles compare over a region of quiet Sun at viewing angles that approach the limb. In addition to the observations, we synthesize both line profiles using a 3D radiation-MHD simulation. In the observations, we find that the peak width and the peak intensities are well correlated between the lines. For the simulation, we do not find the same relationship. We have attempted to mitigate the instrumental differences between IRIS and CLASP and to reproduce the instrumental factors in the synthetic profiles. The model indicates that formation heights of the lines differ in a somewhat regular fashion related to magnetic geometry. This variation explains to some degree the lack of correlation, observed and synthesized, between Mg ii and Ly α . Our analysis will aid in the definition of future observatories that aim to link dynamics in the chromosphere and transition region.« less

KECK ECHELLETTE SPECTROGRAPH AND IMAGER OBSERVATIONS OF METAL-POOR DAMPED Ly{alpha} SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penprase, Bryan E.; Toro-Martinez, Irene; Beeler, Daniel J.

2010-09-20

We present the first results from a survey of SDSS quasars selected for strong H I damped Ly{alpha} (DLA) absorption with corresponding low equivalent width absorption from strong low-ion transitions (e.g., C II {lambda}1334 and Si II {lambda}1260). These metal-poor DLA candidates were selected from the SDSS fifth release quasar spectroscopic database, and comprise a large new sample for probing low-metallicity galaxies. Medium-resolution echellette spectra from the Keck Echellette Spectrograph and Imager spectrograph for an initial sample of 35 systems were obtained to explore the metal-poor tail of the DLA distribution and to investigate the nucleosynthetic patterns at these metallicities.more » We have estimated saturation corrections for the moderately underresolved spectra, and systems with very narrow Doppler parameters (b {<=} 5 km s{sup -1}) will likely have underestimated abundances. For those systems with Doppler parameters b > 5 km s{sup -1}, we have measured low-metallicity DLA gas with [X/H] <-2.4 for at least one of C, O, Si, or Fe. Assuming non-saturated components, we estimate that several DLA systems have [X/H] <-2.8, including five DLA systems with both low equivalent widths and low metallicity in transitions of both C II and O I. All of the measured DLA metallicities, however, exceed or are consistent with a metallicity of at least 1/1000 of solar, regardless of the effects of saturation in our spectra. Our results indicate that the metal-poor tail of galaxies at z {approx} 3 drops exponentially at [X/H] {approx}<-3. If the distribution of metallicity is Gaussian, the probability of identifying interstellar medium gas with lower abundance is extremely small, and our results suggest that DLA systems with [X/H] < -4.0 are extremely rare, and could comprise only 8 x 10{sup -7} of DLA systems. The relative abundances of species within these low-metallicity DLA systems are compared with stellar nucleosynthesis models, and are consistent with stars having masses of 30 M{sub sun} < M{sub *} < 100 M{sub sun}. The observed ratio of [C/O] for values of [O/H] <-2.5 exceeds values seen in moderate metallicity DLA systems, and also exceeds theoretical nucleosynthesis predictions for higher mass Population III stars. We also have observed a correlation between the column density N(C IV) with [Si/H] metallicity, suggestive of a trend between mass of the DLA system and its metallicity.« less

Resistance of the Brain to Escherichia coli K1 Infection Depends on MyD88 Signaling and the Contribution of Neutrophils and Monocytes

PubMed Central

Regen, Tommy; Meister, Tanja; Tauber, Simone C.; Schütze, Sandra; Mildner, Alexander; Mack, Matthias; Hanisch, Uwe-Karsten; Nau, Roland

2013-01-01

Escherichia coli is the leading cause of Gram-negative neonatal bacterial meningitis and also causes meningitis and meningoencephalitis in older and immunocompromised patients. Here, we determined the contribution of granulocytes, monocytes, and TLR signaling cascades in the resistance of adult mice to Escherichia coli K1 brain infection. Deficiency in MyD88 (myd88−/−) but not in TRIF (triflps2) adaptor proteins dramatically reduced the survival of animals. Depletion of CD11b+ Ly-6G+ Ly-6Cint neutrophils by application of the anti-Ly-6G (1A8) monoclonal antibody (MAb) led to higher bacterial loads in cerebellum and spleen tissue and resulted in increased mortality compared to those of isotype-treated controls. Depletion of CD11b+ Ly-6G+ Ly-6Cint neutrophils and CD11b+ Ly-6G− Ly-6Chigh monocytes by administration of the anti-Gr-1 (RB6-8C5) MAb rendered mice even more susceptible to the infection, with higher central nervous system (CNS) and spleen bacterial burdens than anti-Ly-6G-treated animals. Depletion of ∼50% of CD11b+ Ly-6G− Ly-6Chigh monocytes by injection of the anti-CCR2 (MC-21) MAb resulted in a trend toward higher mortality compared to that with isotype treatment. Production of interleukin 1β (IL-1β), IL-6, KC, and MIP-2 in the CNS strongly depended on the bacterial load: increased levels of these cytokines/chemokines were found after depletion of CD11b+ Ly-6G+ Ly-6Cint neutrophils alone or together with CD11b+ Ly-6G− Ly-6Chigh monocytes. These findings identify Toll-like receptor (TLR)-MyD88 signaling and neutrophil and monocyte activity as critical elements in the early host defense against E. coli meningitis. PMID:23478323

Resistance of the brain to Escherichia coli K1 infection depends on MyD88 signaling and the contribution of neutrophils and monocytes.

PubMed

Ribes, Sandra; Regen, Tommy; Meister, Tanja; Tauber, Simone C; Schütze, Sandra; Mildner, Alexander; Mack, Matthias; Hanisch, Uwe-Karsten; Nau, Roland

2013-05-01

Escherichia coli is the leading cause of Gram-negative neonatal bacterial meningitis and also causes meningitis and meningoencephalitis in older and immunocompromised patients. Here, we determined the contribution of granulocytes, monocytes, and TLR signaling cascades in the resistance of adult mice to Escherichia coli K1 brain infection. Deficiency in MyD88 (myd88(-/-)) but not in TRIF (trif(lps2)) adaptor proteins dramatically reduced the survival of animals. Depletion of CD11b(+) Ly-6G(+) Ly-6C(int) neutrophils by application of the anti-Ly-6G (1A8) monoclonal antibody (MAb) led to higher bacterial loads in cerebellum and spleen tissue and resulted in increased mortality compared to those of isotype-treated controls. Depletion of CD11b(+) Ly-6G(+) Ly-6C(int) neutrophils and CD11b(+) Ly-6G(-) Ly-6C(high) monocytes by administration of the anti-Gr-1 (RB6-8C5) MAb rendered mice even more susceptible to the infection, with higher central nervous system (CNS) and spleen bacterial burdens than anti-Ly-6G-treated animals. Depletion of ∼50% of CD11b(+) Ly-6G(-) Ly-6C(high) monocytes by injection of the anti-CCR2 (MC-21) MAb resulted in a trend toward higher mortality compared to that with isotype treatment. Production of interleukin 1β (IL-1β), IL-6, KC, and MIP-2 in the CNS strongly depended on the bacterial load: increased levels of these cytokines/chemokines were found after depletion of CD11b(+) Ly-6G(+) Ly-6C(int) neutrophils alone or together with CD11b(+) Ly-6G(-) Ly-6C(high) monocytes. These findings identify Toll-like receptor (TLR)-MyD88 signaling and neutrophil and monocyte activity as critical elements in the early host defense against E. coli meningitis.

Insulin-mediated inhibition of p38 mitogen-activated protein kinase protects cardiomyocytes in severe burns.

PubMed

Lv, Gen-fa; Dong, Mao-long; Hu, Da-hai; Zhang, Wan-fu; Wang, Yun-chuan; Tang, Chao-wu; Zhu, Xiong-xiang

2011-01-01

Thermal injury inhibits Akt activation and upregulates p38 mitogen-activated protein kinase, which in turn induces inflammation and increases apoptosis. This study aimed to elucidate the mechanism underlying the cytoprotective role of insulin in severe burns by examining the effects of insulin on inflammation and apoptosis mediated by p38 mitogen-activated protein kinase in burn serum-challenged cardiomyocytes. Neonatal rat cardiomyocytes were exposed to burn serum for 6 hours in the presence or absence of insulin and pretreated with inhibitors to p38 mitogen-activated protein kinase (SB203580) and Akt (LY294002). The authors examined expression of myocardial tumor necrosis factor-alpha, cardiac myofilament proteins caspase-3 and Bcl2, and apoptosis. Burn serum-induced upregulation of tumor necrosis factor was inhibited by both SB203580 and insulin. LY294002 reversed insulin-mediated downregulation of tumor necrosis factor. Both SB203580 and insulin inhibited apoptosis, resulting in fewer pyknotic nuclei and inhibition of caspase-3 activation and Bcl2 downregulation. LY294002 reversed insulin-mediated inhibition of apoptosis. Insulin decreases inflammatory cytokine expression and apoptosis via PI3K/Akt-mediated inhibition of p38 mitogen-activated protein kinase. The cytoprotective role of insulin suggests that it may have a potential role in strategies for treating thermal injuries.

Evolution of Structure in the Intergalactic Medium and the Nature of the LY-Alpha Forest

NASA Technical Reports Server (NTRS)

Bi, Hongguang; Davidsen, Arthur F.

1997-01-01

We have performed a detailed statistical study of the evolution of structure in a photoionized intergalactic medium (IGM) using analytical simulations to extend the calculation into the mildly nonlinear density regime found to prevail at z = 3. Our work is based on a simple fundamental conjecture: that the probability distribution function of the density of baryonic diffuse matter in the universe is described by a lognormal (LN) random field. The LN distribution has several attractive features and follows plausibly from the assumption of initial linear Gaussian density and velocity fluctuations at arbitrarily early times. Starting with a suitably normalized power spectrum of primordial fluctuations in a universe dominated by cold dark matter (CDM), we compute the behavior of the baryonic matter, which moves slowly toward minima in the dark matter potential on scales larger than the Jeans length. We have computed two models that succeed in matching observations. One is a nonstandard CDM model with OMEGA = 1, h = 0.5, and GAMMA = 0.3, and the other is a low-density flat model with a cosmological constant (LCDM), with OMEGA = 0.4, OMEGA(sub LAMBDA) = 0.6, and h = 0.65. In both models, the variance of the density distribution function grows with time, reaching unity at about z = 4, where the simulation yields spectra that closely resemble the Ly-alpha forest absorption seen in the spectra of high-z quasars. The calculations also successfully predict the observed properties of the Ly-alpha forest clouds and their evolution from z = 4 down to at least z = 2, assuming a constant intensity for the metagalactic UV background over this redshift range. However, in our model the forest is not due to discrete clouds, but rather to fluctuations in a continuous intergalactic medium. At z = 3; typical clouds with measured neutral hydrogen column densities N(sub H I) = 10(exp 13.3), 10(exp 13.5), and 10(exp 11.5) /sq cm correspond to fluctuations with mean total densities approximately 10, 1, and 0.1 times the universal mean baryon density. Perhaps surprisingly, fluctuations whose amplitudes are less than or equal to the mean density still appear as "clouds" because in our model more than 70% of the volume of the IGM at z = 3 is filled with gas at densities below the mean value.

The role of stem cell mobilization regimen on lymphocyte collection yield in patients with multiple myeloma.

PubMed

Hiwase, D K; Hiwase, S; Bailey, M; Bollard, G; Schwarer, A P

2008-01-01

The lymphocyte dose (LY-DO) infused during an autograft influences absolute lymphocyte (ALC) recovery and survival following autologous stem cell transplantation (ASCT) in multiple myeloma (MM) patients. Factors influencing lymphocyte yield (LY-C) during leukapheresis have been poorly studied. Factors that could influence survival, LY-C and CD34(+) cell yield were analyzed in 122 MM patients. Three mobilization regimens were used, granulocyte-colony-stimulating factor (G-CSF) alone (n=13), cyclophosphamide 1-2 g/m(2) plus G-CSF (LD-CY, n=62) and cyclophosphamide 3-4 g/m(2) and G-CSF (ID-CY, n=47). Using multivariate analysis, age, LY-C, ALC on day 30 (ALC-30) and International Staging System stage significantly influenced overall (OS) and progression-free survival (PFS) following ASCT. PFS (56 versus 29 months, P=0.05) and OS (72 versus 49 months; P=0.07) were longer in the LY-C>or=0.12x10(9)/kg group than the LY-C<0.12x10(9)/kg group. LY-C also influenced ALC on day 15 (ALC-15). Mobilization regimen, lymphocytes on the day of leukapheresis, prior radiotherapy and number of leukaphereses significantly influenced LY-C. Significantly higher LY-C was obtained with G-CSF alone compared with the LD-CY and ID-CY groups. CD34(+) count on the day of leukapheresis, prior chemotherapy with prednisone, cyclophosphamide, adriamycin and BCNU or melphalan, and stem cell mobilization regimen significantly influenced CD34(+) cell yield. LY-C influenced ALC-15 and survival following ASCT. Factors that influenced CD34(+) cell yield and LY-C during leukapheresis were different. Mobilization should be tailored to maximize the LY-C and CD34(+) cell yield.

Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64. 3.1

NASA Technical Reports Server (NTRS)

Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.;

Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+641. 2.5

NASA Technical Reports Server (NTRS)

Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.;

[Change of chart genes expression in small intestines of mouse induced by electromagnetic pulse irradiation].

PubMed

Ren, Dongqing; Jin, Juan; Li, Xiaojuan; Zeng, Guiying

2008-01-01

To explore the bio-effects of electromagnetic pulse(EMP) on mouse small intestines induced by means of gene chip. Twelve BALB/c mice were randomly assigned to the normal control group and the EMP group with 6 in each group. The EMP group was irradiated with 200 kV/m, 200 pulses EMP. 18 hours after the irradiation, the mice were sacrificed and their jejunum of small intestines were eviscerated. The fluorescent cDNA probes labeled with Cy3 and Cy5 were prepared from RNA extracted from the intestines of the two groups. Probes of the two groups were then hybridized against cDNA gene chip, the fluorescent signals were scanned with a scanner and the results were analyzed by computer. Compared with the control, 56 genes in gene expression profile were altered. The expression levels of 37 genes were up-regulated distinctly while 19 genes were down-regulated significantly. Among the 56 genes, 19 were reported with known or inferred functions, 12 up-regulated genes were catenin alpha 1 (alpha-catenin), ly-6 alloantigen(Ly-6E), fructose-6-phosphate transaminase (GF6P), ribosomal protein S17 (rpS17), small proline-rich protein 2A (Sprr2a), glandular kallikrein27 (GK27), lipoxygenase-3, aldo-keto reductase (Akr1c12), GSG1, amylase 2 (Amy2),elastase 2, p6-5 gene and 7 down-regulated genes were junctional adhesion molecule (Jam), protein arginine methyltransferase (Carm1),NNP-1, 2-5 A synthetase L2,Mlark gene, ATP synthase alpha subunit, uncoupling protein-2 (Ucp2) gene; the other 37 were reported with unknown functions. EMP irradiation could induce specific expressions of some genes in mouse small intestines and most of these genes were up-regulated ones.

Optical alignment of the Chromospheric Lyman-Alpha Spectro-Polarimeter using sophisticated methods to minimize activities under vacuum

NASA Astrophysics Data System (ADS)

Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.; Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.; Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.

2016-07-01

The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding-rocket instrument developed at the National Astronomical Observatory of Japan (NAOJ) as a part of an international collaboration. The instrument main scientific goal is to achieve polarization measurement of the Lyman-α line at 121.56 nm emitted from the solar upper-chromosphere and transition region with an unprecedented 0.1% accuracy. The optics are composed of a Cassegrain telescope coated with a "cold mirror" coating optimized for UV reflection and a dual-channel spectrograph allowing for simultaneous observation of the two orthogonal states of polarization. Although the polarization sensitivity is the most important aspect of the instrument, the spatial and spectral resolutions of the instrument are also crucial to observe the chromospheric features and resolve the Ly-α profiles. A precise alignment of the optics is required to ensure the resolutions, but experiments under vacuum conditions are needed since Ly-α is absorbed by air, making the alignment experiments difficult. To bypass this issue, we developed methods to align the telescope and the spectrograph separately in visible light. We explain these methods and present the results for the optical alignment of the CLASP telescope and spectrograph. We then discuss the combined performances of both parts to derive the expected resolutions of the instrument, and compare them with the flight observations performed on September 3rd 2015.

Platelet-derived-growth-factor-induced signalling in human platelets: phosphoinositide-3-kinase-dependent inhibition of platelet activation.

PubMed Central

Selheim, F; Fukami, M H; Holmsen, H; Vassbotn, F S

2000-01-01

Human platelets release platelet-derived growth factor (PDGF) from alpha-granules during platelet activation. We have previously shown that platelets have PDGF alpha-receptors, a transmembrane tyrosine kinase that takes part in negative feedback regulation during platelet activation. Here we have described a study of PDGF-induced tyrosine phosphorylation of platelet substrates and phosphoinositide 3-kinase (PI-3K) activity in collagen-stimulated platelets. By immunoblotting with phosphotyrosine antibodies of collagen-activated platelets we found that PDGF increased the phosphorylation of several platelet substrates, e.g. pp140, pp120 and pp85. PDGF inhibited collagen-induced platelet activation in the presence of inhibitors of autocrine stimulation, thus blocking the pure collagen-induced signal transduction. PDGF enhanced the collagen-induced formation of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) as measured by HPLC. Wortmannin and LY294002, two unrelated inhibitors of PI-3K, were used to investigate the role of PI-3K in PDGF-induced platelet signalling. Incubation of platelets with wortmannin and LY294002 blocked the formation of three phosphorylated inositides as well as the inhibitory effect of PDGF on collagen-induced platelet activation. We conclude that the inhibitory effect of PDGF on platelet activation is PI-3K dependent. This is the first demonstration of a negative regulatory function of 3-phosphorylated inositides in platelets. PMID:10947961

Platelet-derived-growth-factor-induced signalling in human platelets: phosphoinositide-3-kinase-dependent inhibition of platelet activation.

PubMed

Selheim, F; Fukami, M H; Holmsen, H; Vassbotn, F S

2000-09-01

Human platelets release platelet-derived growth factor (PDGF) from alpha-granules during platelet activation. We have previously shown that platelets have PDGF alpha-receptors, a transmembrane tyrosine kinase that takes part in negative feedback regulation during platelet activation. Here we have described a study of PDGF-induced tyrosine phosphorylation of platelet substrates and phosphoinositide 3-kinase (PI-3K) activity in collagen-stimulated platelets. By immunoblotting with phosphotyrosine antibodies of collagen-activated platelets we found that PDGF increased the phosphorylation of several platelet substrates, e.g. pp140, pp120 and pp85. PDGF inhibited collagen-induced platelet activation in the presence of inhibitors of autocrine stimulation, thus blocking the pure collagen-induced signal transduction. PDGF enhanced the collagen-induced formation of PtdIns(3,4)P(2) and PtdIns(3,4,5)P(3) as measured by HPLC. Wortmannin and LY294002, two unrelated inhibitors of PI-3K, were used to investigate the role of PI-3K in PDGF-induced platelet signalling. Incubation of platelets with wortmannin and LY294002 blocked the formation of three phosphorylated inositides as well as the inhibitory effect of PDGF on collagen-induced platelet activation. We conclude that the inhibitory effect of PDGF on platelet activation is PI-3K dependent. This is the first demonstration of a negative regulatory function of 3-phosphorylated inositides in platelets.

Observation of X-ray lines from a gamma-ray burst (GRB991216): evidence of moving ejecta from the progenitor.

PubMed

Piro, L; Garmire, G; Garcia, M; Stratta, G; Costa, E; Feroci, M; Mészáros, P; Vietri, M; Bradt, H; Frail, D; Frontera, F; Halpern, J; Heise, J; Hurley, K; Kawai, N; Kippen, R M; Marshall, F; Murakami, T; Sokolov, V V; Takeshima, T; Yoshida, A

2000-11-03

We report on the discovery of two emission features observed in the x-ray spectrum of the afterglow of the gamma-ray burst (GRB) of 16 December 1999 by the Chandra X-ray Observatory. These features are identified with the Ly(alpha) line and the narrow recombination continuum by hydrogenic ions of iron at a redshift z = 1.00 +/- 0.02, providing an unambiguous measurement of the distance of a GRB. Line width and intensity imply that the progenitor of the GRB was a massive star system that ejected, before the GRB event, a quantity of iron approximately 0.01 of the mass of the sun at a velocity approximately 0.1 of the speed of light, probably by a supernova explosion.

Ly49 Receptors: Innate and Adaptive Immune Paradigms

PubMed Central

Rahim, Mir Munir A.; Tu, Megan M.; Mahmoud, Ahmad Bakur; Wight, Andrew; Abou-Samra, Elias; Lima, Patricia D. A.; Makrigiannis, Andrew P.

2014-01-01

The Ly49 receptors are type II C-type lectin-like membrane glycoproteins encoded by a family of highly polymorphic and polygenic genes within the mouse natural killer (NK) gene complex. This gene family is designated Klra, and includes genes that encode both inhibitory and activating Ly49 receptors in mice. Ly49 receptors recognize class I major histocompatibility complex-I (MHC-I) and MHC-I-like proteins on normal as well as altered cells. Their functional homologs in humans are the killer cell immunoglobulin-like receptors, which recognize HLA class I molecules as ligands. Classically, Ly49 receptors are described as being expressed on both the developing and mature NK cells. The inhibitory Ly49 receptors are involved in NK cell education, a process in which NK cells acquire function and tolerance toward cells that express “self-MHC-I.” On the other hand, the activating Ly49 receptors recognize altered cells expressing activating ligands. New evidence shows a broader Ly49 expression pattern on both innate and adaptive immune cells. Ly49 receptors have been described on multiple NK cell subsets, such as uterine NK and memory NK cells, as well as NKT cells, dendritic cells, plasmacytoid dendritic cells, macrophages, neutrophils, and cells of the adaptive immune system, such as activated T cells and regulatory CD8+ T cells. In this review, we discuss the expression pattern and proposed functions of Ly49 receptors on various immune cells and their contribution to immunity. PMID:24765094

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin, E-mail: Jqin710@vip.sina.com

Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-addedmore » active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.« less

Propionibacterium acnes overabundance and natural killer group 2 member D system activation in corpus-dominant lymphocytic gastritis.

PubMed

Montalban-Arques, Ana; Wurm, Philipp; Trajanoski, Slave; Schauer, Silvia; Kienesberger, Sabine; Halwachs, Bettina; Högenauer, Christoph; Langner, Cord; Gorkiewicz, Gregor

2016-12-01

Corpus-dominant lymphocytic gastritis (LyG) is characterized by CD8 + T-cell infiltration of the stomach epithelium by a so far uncharacterized mechanism. Although Helicobacter pylori is typically undetectable in LyG, patients respond to H. pylori antibiotic eradication therapy, suggesting a non-H. pylori microbial trigger for the disease. Comparative microbiota analysis of specimens from LyG, H. pylori gastritis and healthy controls precluded involvement of H. pylori in LyG but identified Propionibacterium acnes as a possible disease trigger. In addition, the natural killer group 2 member D (NKG2D) system and the proinflammatory cytokine interleukin (IL)-15 are significantly upregulated in the gastric mucosa of LyG patients, and gastric epithelial cells respond to microbe-derived stimuli, including live P. acnes and the microbial products short-chain fatty acids, with induction of NKG2D ligands. In contrast, H. pylori infection does not activate or even repress NKG2D ligands. Together, our findings identify P. acnes as a possible causative agent for LyG, which is dependent on the NKG2D system and IL-15 activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Lyα-Lyman continuum connection in 3.5 ≤ z ≤ 4.3 star-forming galaxies from the VUDS survey

NASA Astrophysics Data System (ADS)

Marchi, F.; Pentericci, L.; Guaita, L.; Schaerer, D.; Verhamme, A.; Castellano, M.; Ribeiro, B.; Garilli, B.; Fèvre, O. Le; Amorin, R.; Bardelli, S.; Cassata, P.; Durkalec, A.; Grazian, A.; Hathi, N. P.; Lemaux, B. C.; Maccagni, D.; Vanzella, E.; Zucca, E.

2018-06-01

Context. To identify the galaxies responsible for the reionization of the Universe, we must rely on the investigation of the Lyman continuum (LyC) properties of z ≲ 5 star-forming galaxies, where we can still directly observe their ionizing radiation. Aims: The aim of this work is to explore the correlation between the LyC emission and some of the proposed indirect indicators of LyC radiation at z 4 such as a bright Lyα emission and a compact UV continuum size. Methods: We selected a sample of 201 star-forming galaxies from the Vimos Ultra Deep Survey (VUDS) at 3.5 ≤ z ≤ 4.3 in the COSMOS, ECDFS, and VVDS-2h fields, including only those with reliable spectroscopic redshifts, a clean spectrum in the LyC range and clearly not contaminated by bright nearby sources in the same slit. For all galaxies we measured the Lyα EW, the Lyα velocity shift with respect to the systemic redshift, the Lyα spatial extension and the UV continuum effective radius. We then selected different sub-samples according to the properties predicted to be good LyC emission indicators: in particular we created sub-samples of galaxies with EW(Lyα) ≥ 70 Å, Lyαext ≤ 5.7 kpc, rUV ≤ 0.30 kpc and |ΔvLyα|≤ 200 km s-1. We stacked all the galaxies in each sub-sample and measured the flux density ratio (fλ(895)/fλ(1470)), that we considered to be a proxy for LyC emission. We then compared these ratios to those obtained for the complementary samples. Finally, to estimate the statistical contamination from lower redshift inter-lopers in our samples, we performed dedicated Monte Carlo simulations using an ultradeep U-band image of the ECDFS field. Results: We find that the stacks of galaxies which are UV compact (rUV ≤ 0.30 kpc) and have bright Lyα emission (EW(Lyα) ≥ 70 Å), have much higher LyC fluxes compared to the rest of the galaxy population. These parameters appear to be good indicators of LyC radiation in agreement with theoretical studies and previous observational works. In addition we find that galaxies with a low Lyα spatial extent (Lyαext ≤ 5.7 kpc) have higher LyC flux compared to the rest of the population. Such a correlation had never been analysed before and seems even stronger than the correlation with high EW(Lyα) and small rUV. These results assume that the stacks from all sub-samples present the same statistical contamination from lower redshift interlopers. If we subtract a statistical contamination from low redshift interlopers obtained with the simulations from the flux density ratios (fλ(895)/fλ(1470)) of the significant sub-samples we find that these samples contain real LyC leaking flux with a very high probability, although the true average escape fractions are very uncertain. Conclusions: Our work indicates that galaxies with very high EW(Lyα), small Ly αext and small rUV are very likely the best candidates to show Lyman continuum radiation at z 4 and could therefore be the galaxies that have contributed most to reionisation. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Program 185.A-0791.

CHEMICAL ENRICHMENT OF DAMPED Ly{alpha} SYSTEMS AS A DIRECT CONSTRAINT ON POPULATION III STAR FORMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulkarni, Girish; Hennawi, Joseph F.; Rollinde, Emmanuel

2013-08-01

Observations of damped Ly{alpha} absorbers (DLAs) can be used to measure gas-phase metallicities at large cosmological look-back times with high precision. Furthermore, relative abundances can still be measured accurately deep into the reionization epoch (z > 6) using transitions redward of Ly{alpha}, even though Gunn-Peterson absorption precludes measurement of neutral hydrogen. In this paper, we study the chemical evolution of DLAs using a model for the coupled evolution of galaxies and the intergalactic medium (IGM), which is constrained by a variety of observations. Our goal is to explore the influence of Population III stars on the abundance patterns of DLAsmore » to determine the degree to which abundance measurements can discriminate between different Population III stellar initial mass functions (IMFs). We include effects, such as inflows onto galaxies due to cosmological accretion and outflows from galaxies due to supernova feedback. A distinct feature of our model is that it self-consistently calculates the effect of Population III star formation on the reionization of an inhomogeneous IGM, thus allowing us to calculate the thermal evolution of the IGM and implement photoionization feedback on low-mass galaxy formation. We find that if the critical metallicity of Population III to II/I transition is {approx}< 10{sup -4} Z{sub Sun }, then the cosmic Population III star formation rate drops to zero for z < 8. Nevertheless, at high redshift (z {approx} 6), chemical signatures of Population III stars remain in low-mass galaxies (halo mass {approx}< 10{sup 9} M{sub Sun }). This is because photoionization feedback suppresses star formation in these galaxies until relatively low redshift (z {approx} 10), and the chemical record of their initial generation of Population III stars is retained. We model DLAs as these low-mass galaxies, and assign to them a mass-dependent H I absorption cross-section in order to predict the expected distribution of DLA abundance ratios. We find that these distributions are anchored toward abundance ratios set by Population II supernova yields, but they exhibit a tail which depends significantly on the Population III IMF for z > 5. Thus, a sample of DLA metallicity and relative abundance measurements at high redshift holds the promise to constrain Population III enrichment and the Population III IMF. We find that a sample of just 10 DLAs with relative abundances measured to an accuracy of 0.1 dex is sufficient to constrain the Population III IMF at 4{sigma}. These constraints may prove stronger than other probes of Population III enrichment, such as metal-poor stars and individual metal-poor DLAs. Our results provide a global picture of the thermal, ionization, and chemical evolution of the universe, and have the potential to rule out certain Population III scenarios.« less

New Action of Inhibin Alpha Subunit in Advanced Prostate Cancer

DTIC Science & Technology

2009-02-01

are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by...tumors. For detailed description of the methodology see Appendix 1. Positive immunostaining for human mitochondrial protein confirmed that the...m et as ta si s (% ag e) PC 3 E V PC 3 IN H A ly m ph n od e vo lu m e (m m 3 ) 5 no difference in LVD in peritumoral and surrounding non

Observations of polar aurora on Jupiter

NASA Technical Reports Server (NTRS)

Lane, A. L.; Clarke, J. T.; Moos, H. W.; Atreya, S. K.

1981-01-01

North-south spatial maps of Jupiter were obtained with the SWP camera in IUE observations of 10 December 1978, 19 May 1979, and 7 June 1979. Bright auroral emissions were detected from the north and south polar regions at H Ly alpha (1216 A) and in the H2 Lyman bands (1250-1608 A) on 19 May 1979; yet no enhanced polar emission was detected on the other days. The relationship between the IUE observing geometry and the geometry of the Jovian magnetosphere is discussed.

Lick slit spectra of thirty-eight objective prism quasar candidates and low metallicity halo stars

NASA Technical Reports Server (NTRS)

Tytler, David; Fan, Xiao-Ming; Junkkarinen, Vesa T.; Cohen, Ross D.

1993-01-01

Lick Observatory slit spectra of 38 objects which were claimed to have pronounced UV excess and emission lines are presented. Eleven QSOs, four galaxies at z of about 0.1, 22 stars, and one unidentified object with a low S/N spectrum were found. Of 11 objects which Zhan and Chen (1987, 1989) suggested were QSO with z(prism) not greater than 2.8; eight are QSOs. Six of the QSOs show absorption systems, including Q0000+027A with a relatively strong associated C IV absorption system, and Q0008+008 with a damped Ly-alpha system with an H I column density of 10 exp 21/sq cm. The equivalent widths of the Ca II K line, the G band, and the Balmer lines in 10 stars with the best spectra are measured, and metallicities are derived. Seven of them are in the range -2.5 to -1.7, while the others are less metal-poor.

THE ANATOMY OF AN EXTREME STARBURST WITHIN 1.3 Gyr OF THE BIG BANG REVEALED BY ALMA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carilli, C. L.; Riechers, D.; Walter, F.

We present further analysis of the [C II] 158 {mu}m fine structure line and thermal dust continuum emission from the archetype extreme starburst/active galactic nucleus (AGN) group of galaxies in the early universe, BRI 1202-0725 at z = 4.7, using the Atacama Large Millimeter Array. The group has long been noted for having a closely separated (26 kpc in projection) FIR-hyperluminous quasar host galaxy and an optically obscured submillimeter galaxy (SMG). A short ALMA test observation reveals a rich laboratory for the study of the myriad processes involved in clustered massive galaxy formation in the early universe. Strong [C II]more » emission from the SMG and the quasar have been reported earlier by Wagg et al. based on these observations. In this paper, we examine in more detail the imaging results from the ALMA observations, including velocity channel images, position-velocity plots, and line moment images. We present detections of [C II] emission from two Ly{alpha}-selected galaxies in the group, demonstrating the relative ease with which ALMA can detect the [C II] emission from lower star formation rate galaxies at high redshift. Imaging of the [C II] emission shows a clear velocity gradient across the SMG, possibly indicating rotation or a more complex dynamical system on a scale {approx}10 kpc. There is evidence in the quasar spectrum and images for a possible outflow toward the southwest, as well as more extended emission (a {sup b}ridge{sup )}, between the quasar and the SMG, although the latter could simply be emission from Ly{alpha}-1 blending with that of the quasar at the limited spatial resolution of the current observations. These results provide an unprecedented view of a major merger of gas-rich galaxies driving extreme starbursts and AGN accretion during the formation of massive galaxies and supermassive black holes within 1.3 Gyr of the big bang.« less

A HUBBLE SPACE TELESCOPE/COSMIC ORIGINS SPECTROGRAPH SEARCH FOR WARM-HOT BARYONS IN THE Mrk 421 SIGHT LINE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danforth, Charles W.; Stocke, John T.; Keeney, Brian A.

2011-12-10

Thermally broadened Ly{alpha} absorbers (BLAs) offer an alternate method to using highly ionized metal absorbers (O VI, O VII, etc.) to probe the warm-hot intergalactic medium (WHIM, T = 10{sup 5}-10{sup 7} K). Until now, WHIM surveys via BLAs have been no less ambiguous than those via far-UV and X-ray metal-ion probes. Detecting these weak, broad features requires background sources with a well-characterized far-UV continuum and data of very high quality. However, a recent Hubble Space Telescope/Cosmic Origins Spectrograph (COS) observation of the z = 0.03 blazar Mrk 421 allows us to perform a metal-independent search for WHIM gas withmore » unprecedented precision. The data have high signal-to-noise ratio (S/N Almost-Equal-To 50 per {approx}20 km s{sup -1} resolution element) and the smooth, power-law blazar spectrum allows a fully parametric continuum model. We analyze the Mrk 421 sight line for BLA absorbers, particularly for counterparts to the proposed O VII WHIM systems reported by Nicastro et al. based on Chandra/Low Energy Transmission Grating observations. We derive the Ly{alpha} profiles predicted by the X-ray observations. The S/N of the COS data is high (S/N Almost-Equal-To 25 pixel{sup -1}), but much higher S/N can be obtained by binning the data to widths characteristic of the expected BLA profiles. With this technique, we are sensitive to WHIM gas over a large (N{sub H}, T) parameter range in the Mrk 421 sight line. We rule out the claimed Nicastro et al. O VII detections at their nominal temperatures (T {approx} 1-2 Multiplication-Sign 10{sup 6} K) and metallicities (Z = 0.1 Z{sub Sun }) at {approx}> 2{sigma} level. However, WHIM gas at higher temperatures and/or higher metallicities is consistent with our COS non-detections.« less

Evolution and survival of marine carnivores did not require a diversity of KIR or Ly49 NK cell receptors1

PubMed Central

Hammond, John A.; Guethlein, Lisbeth A.; Abi-Rached, Laurent; Moesta, Achim K; Parham, Peter

2009-01-01

Ly49 lectin-like receptors and killer cell immunoglobulin-like receptors (KIR) are structurally unrelated cell-surface glycoproteins that evolved independently to function as diverse NK cell receptors for MHC class I molecules. Comparison of primates and various domesticated animals has shown that species have either a diverse Ly49 or KIR gene family, but not both. In four pinniped species of wild marine carnivore, three seals and one sea lion, we find that Ly49 and KIR are each represented by single, orthologous genes that exhibit little polymorphism and are transcribed to express cell-surface protein. Pinnipeds are therefore species in which neither Ly49 nor KIR are polygenic but retain the ancestral single-copy state. Whereas pinniped Ly49 has been subject to purifying selection, we find evidence for positive selection on KIR3DL during pinniped evolution. This selection, which focused on the D0 domain and the stem, points to the functionality of the KIR and likely led to the sea lion’s loss of D0. In contrast to the dynamic and rapid evolution of the KIR and Ly49 genes in other species, the pinniped KIR and Ly49 have been remarkably stable during the > 33 million years since the last common ancestor of seals and sea lions. These results demonstrate that long-term survival of placental mammal species need not require a diverse system of either Ly49 or KIR NK-cell receptors. PMID:19265140

T cell-dependent antibody production by Ly-1 B cells.

PubMed

Taki, S; Schmitt, M; Tarlinton, D; Förster, I; Rajewsky, K

1992-05-04

Through the use of a SCID transfer system, we have demonstrated that under certain conditions, the production of Ig by Ly-1 B cells can be modulated by T cells. This modulation can take the form of enhanced isotype production or isotype-switch induction and to some extent appears to be dependent on the activation state of the T cells. Furthermore we have shown that Ly-1 B cells can mount an idiotypically restricted T cell-dependent immune response to the antigen PC-KLH. This result suggests that the previous failure to observe T cell-dependent responses by Ly-1 B cells has been due to these B cells being "blind" to the antigens used and is not due to some inherent property of these B cells. When one considers the previous reports of the substantial contribution of Ly-1 B cells to the natural serum immunoglobulin levels and the ability of T cells to affect Ig production by Ly-1 B cells documented in this report, it is clear that the interaction of T cells with the Ly-1 B-cell population is important in determining the "natural" serum Ig repertoire of the mouse.

Synthesis of crystalline Ce-activated garnet phosphor powders and technique to characterize their scintillation light yield

NASA Astrophysics Data System (ADS)

Gordienko, E.; Fedorov, A.; Radiuk, E.; Mechinsky, V.; Dosovitskiy, G.; Vashchenkova, E.; Kuznetsova, D.; Retivov, V.; Dosovitskiy, A.; Korjik, M.; Sandu, R.

2018-04-01

This work reports on a process of preparation of garnet phosphor powders and a technique for light yield evaluation of strongly light scattering samples. Powders of scintillation compounds could be used as individual materials or as samples for express tests of scintillation properties. However, estimation of their light yield (LY) is complicated by strong light scattering of this kind of materials. Ce3+-activated yttrium-aluminum and gallium-gadolinium-aluminum garnet phosphor powders, Y3Al5O12 (YAG:Ce) and Gd3Ga3Al2O12 (GGAG:Ce), were obtained using a modified coprecipitation technique. Ga tends to residue in mother liquor in ammonia media, but the modification allows to avoid the loss of components. We propose an approach for sample preparation and LY measurement setup with alpha particles excitation, allowing to decrease light scattering influence and to estimate a light yield of powder samples. This approach is used to evaluate the obtained powders.

A Luminous Lyα-emitting Galaxy at Redshift z = 6.535: Discovery and Spectroscopic Confirmation

NASA Astrophysics Data System (ADS)

Rhoads, James E.; Xu, Chun; Dawson, Steve; Dey, Arjun; Malhotra, Sangeeta; Wang, JunXian; Jannuzi, Buell T.; Spinrad, Hyron; Stern, Daniel

2004-08-01

We present a redshift z=6.535 galaxy discovered by its Lyα emission in a 9180 Å narrowband image from the Large Area Lyman Alpha survey. The Lyα line luminosity (1.1×1043 ergs s-1) is among the largest known for star-forming galaxies at z~6.5. The line shows the distinct asymmetry that is characteristic of high-redshift Lyα. The 2 σ lower bound on the observer-frame equivalent width is greater than 530 Å. This is hard to reconcile with a neutral intergalactic medium (IGM) unless the Lyα line is intrinsically strong and is emitted from its host galaxy with an intrinsic Doppler shift of several hundred km s-1. If the IGM is ionized, it corresponds to a rest-frame equivalent width greater than 40 Å after correcting for Lyα forest absorption. We also present a complete spectroscopic follow-up of the remaining candidates with line flux greater than 2×10-17 ergs cm-2 s-1 in our 1200 arcmin2 narrowband image. These include another galaxy with a strong emission line at 9136 Å and no detected continuum flux, which, however, is most likely an [O III] λ5007 source at z=0.824, on the basis of a weak detection of the [O III] λ4959 line. The data presented in this paper were obtained at the Kitt Peak National Observatory, the Gemini Observatory, and the W. M. Keck Observatory. Kitt Peak National Observatory, National Optical Astronomy Observatory, is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), under cooperative agreement with the National Science Foundation (NSF). The Gemini Observatory is operated by AURA under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NSF (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council, CNPq (Brazil), and CONICET (Argentina). The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Keck Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Feasibility of the MUSIC Algorithm for the Active Protection System

DTIC Science & Technology

2001-03-01

Feasibility of the MUSIC Algorithm for the Active Protection System ARL-MR-501 March 2001 Canh Ly Approved for public release; distribution... MUSIC Algorithm for the Active Protection System Canh Ly Sensors and Electron Devices Directorate Approved for public release; distribution unlimited...This report compares the accuracy of the doppler frequency of an incoming projectile with the use of the MUSIC (multiple signal classification

Survival of residual neutrophils and accelerated myelopoiesis limit the efficacy of antibody-mediated depletion of Ly-6G+ cells in tumor-bearing mice.

PubMed

Moses, Katrin; Klein, Johanna C; Männ, Linda; Klingberg, Anika; Gunzer, Matthias; Brandau, Sven

2016-06-01

Expansion of Ly-6G(+) myeloid cells has been reported in most murine cancer models. However, divergent findings exist regarding the role and effect of these cells on host immunity and tumor progression. Antibody-mediated depletion of Ly-6G(+) cells is a common technique to assess the in vivo relevance of these cells. Interpretation of results crucially depends on the efficacy and course of depletion. We established murine head and neck cancer models and analyzed the efficacy of antibody-mediated depletion by flow cytometry, conventional histology, and intravital imaging with a novel Ly-6G-transgenic mouse model. The first phase of depletion was characterized by effective elimination of Ly-6G(+) cells from the peripheral blood. Nevertheless, viable, resistant cells were found to reside in the tumor tissue and spleen. This peripheral depletion phase was associated with high systemic levels of granulocyte colony-stimulating factor and KC and enhanced splenic production of Ly-6G(+) cells. Even under sustained treatment with either αGr-1 or αLy-6G antibodies, peripheral blood depletion ended after approximately 1 wk and was followed by reappearance of immature Ly-6G(+) cells with an immunoregulatory phenotype. Reappearance of these depletion-resistant immature cells was enhanced in tumor-bearing, compared with naïve, control mice. Collectively, our data suggest that depletion of Ly-6G(+) myeloid cells in tumor-bearing mice is counteracted by the persistence of intratumoral cells, enhanced extramedullary granulopoiesis, and accelerated reappearance of immature cells. Hence, extensive monitoring of in vivo kinetics and tissue distribution of Ly-6G(+) cells is required in depletion studies. © Society for Leukocyte Biology.

Neutral particle beam sensing and steering

DOEpatents

Maier, II, William B.; Cobb, Donald D.; Robiscoe, Richard T.

1991-01-01

The direction of a neutral particle beam (NPB) is determined by detecting Ly.alpha. radiation emitted during motional quenching of excited H(2S) atoms in the beam during movement of the atoms through a magnetic field. At least one detector is placed adjacent the beam exit to define an optical axis that intercepts the beam at a viewing angle to include a volume generating a selected number of photons for detection. The detection system includes a lens having an area that is small relative to the NPB area and a pixel array located in the focal plane of the lens. The lens viewing angle and area pixel array are selected to optimize the beam tilt sensitivity. In one embodiment, two detectors are placed coplanar with the beam axis to generate a difference signal that is insensitive to beam variations other than beam tilt.

64Cu-Labeled LyP-1-Dendrimer for PET-CT Imaging of Atherosclerotic Plaque

PubMed Central

2015-01-01

The ability to detect and quantify macrophage accumulation can provide important diagnostic and prognostic information for atherosclerotic plaque. We have previously shown that LyP-1, a cyclic 9-amino acid peptide, binds to p32 proteins on activated macrophages, facilitating the visualization of atherosclerotic plaque with PET. Yet, the in vivo plaque accumulation of monomeric [18F]FBA-LyP-1 was low (0.31 ± 0.05%ID/g). To increase the avidity of LyP-1 constructs to p32, we synthesized a dendritic form of LyP-1 on solid phase using lysine as the core structural element. Imaging probes (FAM or 6-BAT) were conjugated to a lysine or cysteine on the dendrimer for optical and PET studies. The N-terminus of the dendrimer was further modified with an aminooxy group in order to conjugate LyP-1 and ARAL peptides bearing a ketone. Oxime ligation of peptides to both dendrimers resulted in (LyP-1)4- and (ARAL)4-dendrimers with optical (FAM) and PET probes (6-BAT). For PET-CT studies, (LyP-1)4- and (ARAL)4-dendrimer-6-BAT were labeled with 64Cu (t1/2 = 12.7 h) and intravenously injected into the atherosclerotic (ApoE–/–) mice. After two hours of circulation, PET-CT coregistered images demonstrated greater uptake of the (LyP-1)4-dendrimer-64Cu than the (ARAL)4-dendrimer-64Cu in the aortic root and descending aorta. Ex vivo images and the biodistribution acquired at three hours after injection also demonstrated a significantly higher uptake of the (LyP-1)4-dendrimer-64Cu (1.1 ± 0.26%ID/g) than the (ARAL)4-dendrimer-64Cu (0.22 ± 0.05%ID/g) in the aorta. Similarly, subcutaneous injection of the LyP-1-dendrimeric carriers resulted in preferential accumulation in plaque-containing regions over 24 h. In the same model system, ex vivo fluorescence images within aortic plaque depict an increased accumulation and penetration of the (LyP-1)4-dendrimer-FAM as compared to the (ARAL)4-dendrimer-FAM. Taken together, the results suggest that the (LyP-1)4-dendrimer can be applied for in vivo PET imaging of plaque and that LyP-1 could be further exploited for the delivery of therapeutics with multivalent carriers or nanoparticles. PMID:24433095

The Local ISM and its Interaction with the Winds of Nearby Late-type Stars

NASA Technical Reports Server (NTRS)

Wood, Brian E.; Linsky, Jeffrey L.

1998-01-01

We present new Goddard High-Resolution Spectrograph (GHRS) observations of the Ly-alpha and Mg II absorption lines seen toward the nearby stars 61 Cyg A and 40 Eri A. We use these data to measure interstellar properties along these lines of sight and to search for evidence of circumstellar hydrogen walls, which are produced by collisions between the stellar winds and the Local InterStellar Medium (LISM). We were able to model the Ly-alpha lines of both stars without hydrogen-wall absorption components, but for 61 Cyg A the fit required a stellar Ly-alpha, line profile with an improbably deep self-reversal, and for 40 Eri A the fit required a very low deuterium-to-hydrogen ratio that is inconsistent with previous GHRS measurements. Since these problems could be rectified simply by including stellar hydrogen-wall components with reasonable attributes, our preferred fits to the data include these components. We have explored several ways in which the hydrogen-wall properties measured here and in previous work can be used to study stellar winds and the LISM. We argue that the existence of a hydrogen wall around 40 Eri A and a low H I column density along that line of sight imply that either the interstellar density must decrease toward 40 Eri A or the hydrogen ionization fraction (chi) must increase. We find that hydrogen-wall temperatures are larger for stars with faster velocities through the LISM. The observed temperature-velocity relation is consistent with the predictions of hydromagnetic shock jump conditions. More precise comparison of the data and the jump conditions suggests crude upper limits for both chi and the ratio of magnetic to thermal pressure in the LISM (alpha): chi less than 0.6 and alpha less than 2. The latter upper limit corresponds to a limit on the LISM magnetic field of B less than 5 micro G. These results imply that the plasma Mach number of the interstellar wind flowing into the heliosphere is M(sub A) greater than 1.3, which indicates that the collision is supersonic and that there should therefore be a bow shock outside the heliopause in the upwind direction. Finally, we estimate stellar wind pressures (P sub wind) from the measured hydrogen-wall column densities. These estimates represent the first empirical measurements of wind properties for late-type main-sequence stars. The wind pressures appear to be correlated with stellar X-ray surface fluxes, F(x), in a manner consistent with the relation P(wind) varies as F(x)(exp -1/2), a relation that is also consistent with the variations of P(sub wind) and F(sub x) observed during the solar activity cycle. If this relation can in fact be generalized to solar-like stars, as is suggested by our data, then it is possible to estimate stellar wind properties simply by measuring stellar X-rays. One implication of this is that stellar wind pressures and mass-loss rates are then predicted to increase with time, since F(sub x) is known to decrease with stellar age.

A SURVEY OF METAL LINES AT HIGH-REDSHIFT. I. SDSS ABSORPTION LINE STUDIES- THE METHODOLOGY AND FIRST SEARCH RESULTS FOR O VI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, S.; Mathur, S.; Pieri, M.

2010-09-15

We report the results of a systematic search for signatures of metal lines in quasar spectra of the Sloan Digital Sky Survey (SDSS) data release 3 (DR3), focusing on finding intervening absorbers via detection of their O VI doublet. Here, we present the search algorithm and criteria for distinguishing candidates from spurious Ly{alpha} forest lines. In addition, we compare our findings with simulations of the Ly{alpha} forest in order to estimate the detectability of O VI doublets over various redshift intervals. We have obtained a sample of 1756 O VI doublet candidates with rest-frame equivalent width (EW) {>=}0.05 A inmore » 855 active galactic nuclei spectra (out of 3702 objects with redshifts in the accessible range for O VI detection). This sample is further subdivided into three groups according to the likelihood of being real and the potential for follow-up observation of the candidate. The group with the cleanest and most secure candidates is comprised of 145 candidates. Sixty-nine of these reside at a velocity separation {>=}5000 km s{sup -1} from the QSO and can therefore be classified tentatively as intervening absorbers. Most of these absorbers have not been picked up by earlier, automated QSO absorption line detection algorithms. This sample increases the number of known O VI absorbers at redshifts beyond z{sub abs{>=}} 2.7 substantially.« less

CLASP/SJ Observations of Rapid Time Variations in the Ly α Emission in a Solar Active Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishikawa, Shin-nosuke; Kubo, Masahito; Katsukawa, Yukio

The Chromospheric Ly α SpectroPolarimeter (CLASP) is a sounding rocket experiment launched on 2015 September 3 to investigate the solar chromosphere and transition region. The slit-jaw (SJ) optical system captured Ly α images with a high time cadence of 0.6 s. From the CLASP/SJ observations, many variations in the solar chromosphere and transition region emission with a timescale of <1 minute were discovered. In this paper, we focus on the active region within the SJ field of view and investigate the relationship between short (<30 s) temporal variations in the Ly α emission and the coronal structures observed by Solarmore » Dynamics Observatory/Atmospheric Imaging Assembly (AIA). We compare the Ly α temporal variations at the coronal loop footpoints observed in the AIA 211 Å (≈2 MK) and AIA 171 Å (≈0.6 MK) channels with those in the regions with bright Ly α features without a clear association with the coronal loop footpoints. We find more short (<30 s) temporal variations in the Ly α intensity in the footpoint regions. Those variations did not depend on the temperature of the coronal loops. Therefore, the temporal variations in the Ly α intensity at this timescale range could be related to the heating of the coronal structures up to temperatures around the sensitivity peak of 171 Å. No signature was found to support the scenario that these Ly α intensity variations were related to the nanoflares. Waves or jets from the lower layers (lower chromosphere or photosphere) are possible causes for this phenomenon.« less

Intrinsic Lyα Profile Reconstructions of the MUSCLES Low-Mass Exoplanet Host Stars

NASA Astrophysics Data System (ADS)

Youngblood, Allison A.; France, Kevin; Loyd, R. O. Parke

2015-12-01

UV stellar radiation can significantly impact planetary atmospheres through heating and photochemistry, even regulating production of potential biomarkers. Cool stars emit the majority of their UV radiation in the form of emission lines, and the incident UV radiation on close-in habitable-zone planets is significant. Lyα (1215.67 Å) dominates the 912 - 3200 Å spectrum of cool stars, but strong absorption from the interstellar medium (ISM) makes direct observations of the intrinsic Lyα emission of even nearby stars challenging. The MUSCLES Hubble Space Telescope Treasury Survey (Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems) has completed observations of 7 M and 4 K stars hosting exoplanets (d < 22 pc). We have reconstructed the intrinsic Lyα profiles using an MCMC technique and used the results to estimate the extreme ultraviolet (100 - 911 Å) spectrum. We also present empirical relations between Lyα and chromospheric UV metal lines, e.g., Mg II, for use when ISM absorption prevents direct measurement of Lyα. The spectra presented here will be made publicly available through MAST to support exoplanet atmosphere modeling.

PI3K/Akt contributes to increased expression of Toll-like receptor 4 in macrophages exposed to hypoxic stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, So Young; Jeong, Eunshil; Joung, Sun Myung

2012-03-16

Highlights: Black-Right-Pointing-Pointer Hypoxic stress-induced TLR4 expression is mediated by PI3K/Akt in macrophages. Black-Right-Pointing-Pointer PI3K/Akt regulated HIF-1 activation leading to TLR4 expression. Black-Right-Pointing-Pointer p38 mitogen-activated protein kinase was not involved in TLR4 expression by hypoxic stress. Black-Right-Pointing-Pointer Sulforaphane suppressed hypoxia-mediated TLR4 expression by inhibiting PI3K/Akt. -- Abstract: Toll-like receptors (TLRs) play critical roles in triggering immune and inflammatory responses by detecting invading microbial pathogens and endogenous danger signals. Increased expression of TLR4 is implicated in aggravated inflammatory symptoms in ischemic tissue injury and chronic diseases. Results from our previous study showed that TLR4 expression was upregulated by hypoxic stress mediated bymore » hypoxia-inducible factor-1 (HIF-1) at a transcriptional level in macrophages. In this study, we further investigated the upstream signaling pathway that contributed to the increase of TLR4 expression by hypoxic stress. Either treatment with pharmacological inhibitors of PI3K and Akt or knockdown of Akt expression by siRNA blocked the increase of TLR4 mRNA and protein levels in macrophages exposed to hypoxia and CoCl{sub 2}. Phosphorylation of Akt by hypoxic stress preceded nuclear accumulation of HIF-1{alpha}. A PI3K inhibitor (LY294002) attenuated CoCl{sub 2}-induced nuclear accumulation and transcriptional activation of HIF-1{alpha}. In addition, HIF-1{alpha}-mediated upregulation of TLR4 expression was blocked by LY294002. Furthermore, sulforaphane suppressed hypoxia- and CoCl{sub 2}-induced upregulation of TLR4 mRNA and protein by inhibiting PI3K/Akt activation and the subsequent nuclear accumulation and transcriptional activation of HIF-1{alpha}. However, p38 was not involved in HIF-1{alpha} activation and TLR4 expression induced by hypoxic stress in macrophages. Collectively, our results demonstrate that PI3K/Akt contributes to hypoxic stress-induced TLR4 expression at least partly through the regulation of HIF-1 activation. These reveal a novel mechanism for regulation of TLR4 expression upon hypoxic stress and provide a therapeutic target for chronic diseases related to hypoxic stress.« less

Continuing C3 breakdown after bilateral nephrectomy in patients with membrano-proliferative glomerulonephritis.

PubMed

Vallota, E H; Forristal, J; Spitzer, R E; Davis, N C; West, C D

1971-03-01

Serum levels of complement components and of C3 nephritic factor (C3NeF) were measured serially in two patients with membrano-proliferative glomerulonephritis who were subjected to bilateral nephrectomy and maintained by peritoneal dialysis for 2 wk before renal transplantation. In both patients, low levels of C3 and high levels of preformed alpha 2D, a C3 breakdown product, were present before nephrectomy and remained essentially unchanged during the anephric period. With transplantation, C3 levels rose towards normal and alpha 2D disappeared from the serum. The serum of both patients contained detectable amounts of C3NeF, a factor which has been shown to react with a cofactor found in normal serum to form an enzyme, designated C3 lytic nephritic factor (C3LyNeF), which will cleave C3 to form the breakdown products, beta1A and alpha 2D. The level of C3NeF was high in one patient before nephrectomy, increased somewhat during the anephric period, and fell after transplantation. In the other patient, the C3NeF level was initially lower, remained relatively constant during the anephric period, and was not significantly affected by transplantation. In both patients, levels of C4 and C5 were either normal or elevated over the period of the study and bore no relationship to the C3 level. The following conclusions can be drawn from the data. The high levels of alpha 2D during the anephric period and the disappearance of this protein as C3 levels approach normal at the time of transplantation indicate that the low C3 levels were largely the result of C3 breakdown rather than diminished synthesis. The presence of C3NeF in detectable amounts in both patients suggest that C3LyNeF, formed by the reaction of C3NeF and cofactor, was responsible for the low C3 levels. Finally, the lack of effect of nephrectomy on C3, alpha 2D, and C3NeF levels indicate that the site of C3 breakdown was extrarenal and that C3NeF and cofactor are at least in large part of extrarenal origin.

The Solar Spectral Irradiance as a Function of the Mg II Index for Atmosphere and Climate Modelling

NASA Technical Reports Server (NTRS)

Thuillier, Gerard; DeLand, Matthew; Shapiro, Alexander; Schmutz, Werner; Bolsee, David; Melo, Stella

2011-01-01

In this paper we present a new method to reconstruct the solar spectrum irradiance in the Ly alpha-400 nm region, and its variability, based on the Mg II index and neutron monitor. Measurements of the solar spectral irradiance available in the literature have been made with different instruments at different times and different spectral ranges. However, climate studies require harmonized data sets. This new approach has the advantage of being independent of the absolute calibration and aging of the instruments. First, the Mg II index is derived using solar spectra from Ly alpha (121 nm) to 410 nm measured from 1978 to 2010 by several space missions. The variability of the spectra with respect to a chosen reference spectrum as a function of time and wavelength is scaled to the derived Mg II index. The set of coefficients expressing the spectral variability can be applied to the chosen reference spectrum to reconstruct the solar spectra within a given time frame or Mg II index values. The accuracy of this method is estimated using two approaches: by direct comparison with particular cases where solar spectra are available from independent measurements, and by calculating the standard deviation between the measured spectra and their reconstruction. From direct comparisons with measurements we obtain an accuracy of about 1 to 2 %, which degrades towards Ly alpha. In a further step, we extend our solar spectral irradiance reconstruction back to the Maunder Minimum introducing the relationship between the Mg II index and the neutron monitor data. Consistent measurements of the Mg II index are not available prior to 1978. However, we observe that over the last three solar cycles, the Mg II index shows strong correlation with the modulation potential determined from the neutron monitor data. Assuming that this correlation can be applied to the past, we reconstruct the Mg II index from the modulation potential back to the Maunder Minimum, and obtain the corresponding solar spectral irradiance reconstruction back to that period. As there is no direct measurement of the spectral irradiance for this period we discuss this methodology in light of the other proposed approaches available in the literature. The use of the cosmogenic isotope data provides a major advantage: it provides information about the solar activity over several thousands years. Using technology of today we can calibrate the solar irradiance against the activity and thus reconstruct it for the times when cosmogenic isotope data are available. This calibration can be re-accessed at any time, if necessary.

Magnifying the Early Episodes of Star Formation: Super Star Clusters at Cosmological Distances

NASA Astrophysics Data System (ADS)

Vanzella, E.; Castellano, M.; Meneghetti, M.; Mercurio, A.; Caminha, G. B.; Cupani, G.; Calura, F.; Christensen, L.; Merlin, E.; Rosati, P.; Gronke, M.; Dijkstra, M.; Mignoli, M.; Gilli, R.; De Barros, S.; Caputi, K.; Grillo, C.; Balestra, I.; Cristiani, S.; Nonino, M.; Giallongo, E.; Grazian, A.; Pentericci, L.; Fontana, A.; Comastri, A.; Vignali, C.; Zamorani, G.; Brusa, M.; Bergamini, P.; Tozzi, P.

2017-06-01

We study the spectrophotometric properties of a highly magnified (μ ≃ 40{--}70) pair of stellar systems identified at z = 3.2222 behind the Hubble Frontier Field galaxy cluster MACS J0416. Five multiple images (out of six) have been spectroscopically confirmed by means of VLT/MUSE and VLT/X-Shooter observations. Each image includes two faint ({m}{UV}≃ 30.6), young (≲ 100 Myr), low-mass (< {10}7 {M}⊙ ), low-metallicity (12 + Log(O/H) ≃ 7.7, or 1/10 solar), and compact (30 pc effective radius) stellar systems separated by ≃ 300 pc after correcting for lensing amplification. We measured several rest-frame ultraviolet and optical narrow ({σ }v≲ 25 km s-1) high-ionization lines. These features may be the signature of very hot (T> {{50,000}} K) stars within dense stellar clusters, whose dynamical mass is likely dominated by the stellar component. Remarkably, the ultraviolet metal lines are not accompanied by Lyα emission (e.g., C IV/Lyα > 15), despite the fact that the Lyα line flux is expected to be 150 times brighter (inferred from the Hβ flux). A spatially offset, strongly magnified (μ > 50) Lyα emission with a spatial extent ≲ 7.6 kpc2 is instead identified 2 kpc away from the system. The origin of such a faint emission could be the result of fluorescent Lyα induced by a transverse leakage of ionizing radiation emerging from the stellar systems and/or may be associated with an underlying and barely detected object (with {m}{UV}> 34 de-lensed). This is the first confirmed metal-line emitter at such low-luminosity and redshift without Lyα emission—suggesting that, at least in some cases, a non-uniform covering factor of the neutral gas might hamper the Lyα detection. Based on observations collected at the European Southern Observatory for Astronomical research in the southern hemisphere, under ESO programmes P095.A-0840, P095.A-0653, and P186.A-0798.

"Effects of the novel relatively short-acting kappa opioid receptor antagonist LY2444296 in behaviors observed after chronic extended-access cocaine self-administration in rats".

PubMed

Valenza, Marta; Butelman, Eduardo R; Kreek, Mary Jeanne

2017-08-01

The recruitment of the stress circuitry contributes to a shift from positive to negative reinforcement mechanisms sustaining long-term cocaine addiction. The kappa opioid receptor (KOPr) signaling is upregulated by stress and chronic cocaine exposure. While KOPr agonists induce anhedonia and dysphoria, KOPr antagonists display antidepressant and anxiolytic properties. Most of the knowledge on KOPr antagonism is based on drugs with unusual pharmacokinetic and pharmacodynamic properties, complicating interpretation of results. Here we characterized in vivo behavioral and neuroendocrine effects of the novel relatively short-acting KOPr antagonist LY2444296. To date, no study has investigated whether systemic KOPr blockade reduced anxiety-like and depressive-like behaviors in animals previously exposed to chronic extended access cocaine self-administration. We tested the effect of LY2444296 in blocking KOPr-mediated aversive and neuroendocrine effects. Then, we tested acute systemic LY2444296 in reducing anxiety- and depression-like behaviors, as well as releasing the stress hormone corticosterone (CORT), observed after chronic extended access (18 h/day for 14 days) cocaine self-administration. LY2444296 blocked U69,593-induced place aversion and -reduced motor activity as well as U69,593-induced release of serum CORT, confirming its major site of action, without exerting an effect per se. Acute systemic administration of LY2444296 reduced anxiety-like and depressive-like behaviors, as well as CORT release, in rats tested after chronic extended access cocaine self-administration, but not in cocaine-naïve rats. Results suggest that acute blockade of KOPr by a relatively short-acting antagonist produces therapeutic-like effects selectively in rats with a history of chronic extended access cocaine self-administration.

Radiance line ratios Ly-β/Ly-α, Ly-γ/Ly-α, Ly-δ/Ly-α, and Ly-ε/Ly-α for soft X-ray emissions following charge exchange between C 6+ and Kr

DOE Office of Scientific and Technical Information (OSTI.GOV)

V. M. Andrianarijaona; Wulf, D.; McCammon, D.

2015-02-04

The radiance line ratios Ly-β/Ly-α, Ly-γ/Ly-α, Ly-δ/Ly-α, and Ly-ε/Ly-α for soft X-ray emission following charge exchange (CX) between C 6+ and Kr are reported in this paper for collision energies between approximately 320 and 46,000 eV/u. The corresponding collision velocities (250–3000 km/s) are characteristic of the solar wind. X-ray spectra were obtained at the Oak Ridge National Laboratory Multicharged Ion Research Facility using a microcalorimeter X-ray detector with a resolution on the order of 10 eV FWHM. The measured Ly-ε/Ly-α is zero for all considered energies and suggests that very little, if any, capture to 6p occurs. The measured Ly-β/Ly-αmore » and Ly-γ/Ly-α ratios intersect and form a well resolved node around (950 ± 50) km/s, which could be used as an astrophysical velocity indicative tool. The results reported here are compared to calculations for C 6+ + H since no published theory for C 6+ + Kr is known to exist. Finally, double-electron-capture (DEC) and other multi-electron processes are possible. True double capture is estimated to be only 10% of the single-electron-capture (SEC).« less

The HETDEX pilot survey. V. The physical origin of Lyα emitters probed by near-infrared spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Mimi; Finkelstein, Steven L.; Gebhardt, Karl

2014-08-10

We present the results from a Very Large Telescope/SINFONI and Keck/NIRSPEC near-infrared spectroscopic survey of 16 Lyα emitters (LAEs) at z = 2.1-2.5 in the COSMOS and GOODS-N fields discovered from the Hobby Eberly Telescope Dark Energy Experiment Pilot Survey. We detect rest-frame optical nebular lines (Hα and/or [O III] λ5007) for 10 of the LAEs and measure physical properties, including the star formation rate (SFR), gas-phase metallicity, gas mass fraction, and Lyα velocity offset. We find that LAEs may lie below the mass-metallicity relation for continuum-selected star-forming galaxies at the same redshift. The LAEs all show velocity shifts ofmore » Lyα relative to the systemic redshift ranging between +85 and +296 km s{sup –1} with a mean of +180 km s{sup –1}. This value is smaller than measured for continuum-selected star-forming galaxies at similar redshifts. The Lyα velocity offsets show a moderate correlation with the measured SFR (2.5σ), but no significant correlations are seen with the SFR surface density, specific SFR, stellar mass, or dynamical mass (≲1.5σ). Exploring the role of dust, kinematics of the interstellar medium (ISM), and geometry on the escape of Lyα photons, we find no signature of selective quenching of resonantly scattered Lyα photons. However, we also find no evidence that a clumpy ISM is enhancing the Lyα equivalent width. Our results suggest that the low metallicity in LAEs may be responsible for yielding an environment with a low neutral hydrogen column density and less dust, easing the escape of Lyα photons over that in continuum-selected star-forming galaxies.« less

Low-Redshift Damped Ly(alpha) Galaxies Toward the Quasars B2 0827+243, PKS 0952+179, PKS 1127-145, and PKS 1629+120

DTIC Science & Technology

2003-09-20

is defined at 3000 km s1 by the outer boundary of the Virgo cluster (Binggeli, Popescu, & Tammann 1993). We note that it is an LSB galaxy, with LB... Research Laboratory, 4555 OverlookAvenue SW, Code 7600A,Washington, DC 20375 Eric M. Monier Department of Astronomy, Ohio State University, Columbus...Association of Universities for Research in Astronomy (AURA), Inc. (WIYN is a joint facility of University of Wisconsin, Indiana University, Yale University

A Study of Mid-Latitude 5577A CI Dayglow Emissions

DTIC Science & Technology

1992-01-01

The subroutine returns the longwave and shortwave boundaries, WAVE1 and WAVE2 , of the wavelength bins (A), and the solar flux in each bin SFLUX...average 10.7 cm flux (’) C FLYA H Lyman-alpha flux (photons cm-2 s-i) C WAVE 1 longwave bound of spectral intervals (Angstroms) C WAVE2 shortwave bound...currently = 59 C WAVEL = WAVE1 C WAVES = WAVE2 C RFLUX low solar activity reference flux C XFLUX high solar activity flux C SCALE1 scaling factors for H LyB

The line continuum luminosity ratio in AGN: Or on the Baldwin Effect

NASA Technical Reports Server (NTRS)

Mushotzky, R.; Ferland, F. J.

1983-01-01

The luminosity dependence of the equivalent width of CIV in active galaxies, the "Baldwin" effect, is shown to be a consequence of a luminosity dependent ionization parameter. This law also agrees with the lack of a "Baldwin" effect in Ly alpha or other hydrogen lines. A fit to the available data gives a weak indication that the mean covering factor decreases with increasing luminosity, consistent with the inference from X-ray observations. The effects of continuum shape and density on various line ratios of interest are discussed.

Lyman-alpha observations in the vicinity of Saturn with Copernicus

NASA Technical Reports Server (NTRS)

Barker, E.; Cazes, S.; Emerich, C.; Vidal-Madjar, A.; Owen, T.

1980-01-01

For the first time, high-resolution Ly-alpha observations of the Saturn vicinity were completed with the Princeton spectrometer on board the Copernicus satellite. They showed that near a minimum solar activity the emissions related to several sources are 250 + or - 50 rayleighs for the interplanetary medium in a near-downwind direction, less than 100 rayleighs for the rings, 200 + or - 100 rayleighs for a torus linked to the Titan orbit, and 1400 + or - 450 rayleighs for the disk of Saturn. These results induce some constraints through the corresponding theoretical evaluations: the B ring as the primary source of the atoms for the ring emissions; an efficient production mechanism for hydrogen atoms in the Titan torus; and a slightly larger eddy diffusion coefficient in the Saturn atmosphere than in the Jupiter atmosphere near solar minimum.

Differential expression and activation of a family of murine peroxisome proliferator-activated receptors.

PubMed Central

Kliewer, S A; Forman, B M; Blumberg, B; Ong, E S; Borgmeyer, U; Mangelsdorf, D J; Umesono, K; Evans, R M

1994-01-01

To gain insight into the function of peroxisome proliferator-activated receptor (PPAR) isoforms in mammals, we have cloned and characterized two PPAR alpha-related cDNAs (designated PPAR gamma and -delta, respectively) from mouse. The three PPAR isoforms display widely divergent patterns of expression during embryogenesis and in the adult. Surprisingly, PPAR gamma and -delta are not activated by pirinixic acid (Wy 14,643), a potent peroxisome proliferator and activator of PPAR alpha. However, PPAR gamma and -delta are activated by the structurally distinct peroxisome proliferator LY-171883 and linoleic acid, respectively, indicating that each of the isoforms can act as a regulated activator of transcription. These data suggest that tissue-specific responsiveness to peroxisome proliferators, including certain fatty acids, is in part a consequence of differential expression of multiple, pharmacologically distinct PPAR isoforms. Images PMID:8041794

Reactive oxygen species-generating mitochondrial DNA mutation up-regulates hypoxia-inducible factor-1alpha gene transcription via phosphatidylinositol 3-kinase-Akt/protein kinase C/histone deacetylase pathway.

PubMed

Koshikawa, Nobuko; Hayashi, Jun-Ichi; Nakagawara, Akira; Takenaga, Keizo

2009-11-27

Lewis lung carcinoma-derived high metastatic A11 cells constitutively overexpress hypoxia-inducible factor (HIF)-1alpha mRNA compared with low metastatic P29 cells. Because A11 cells exclusively possess a G13997A mutation in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene, we addressed here a causal relationship between the ND6 mutation and the activation of HIF-1alpha transcription, and we investigated the potential mechanism. Using trans-mitochondrial cybrids between A11 and P29 cells, we found that the ND6 mutation was directly involved in HIF-1alpha mRNA overexpression. Stimulation of HIF-1alpha transcription by the ND6 mutation was mediated by overproduction of reactive oxygen species (ROS) and subsequent activation of phosphatidylinositol 3-kinase (PI3K)-Akt and protein kinase C (PKC) signaling pathways. The up-regulation of HIF-1alpha transcription was abolished by mithramycin A, an Sp1 inhibitor, but luciferase reporter and chromatin immunoprecipitation assays indicated that Sp1 was necessary but not sufficient for HIF-1alpha mRNA overexpression in A11 cells. On the other hand, trichostatin A, a histone deacetylase (HDAC) inhibitor, markedly suppressed HIF-1alpha transcription in A11 cells. In accordance with this, HDAC activity was high in A11 cells but low in P29 cells and in A11 cells treated with the ROS scavenger ebselene, the PI3K inhibitor LY294002, and the PKC inhibitor Ro31-8220. These results suggest that the ROS-generating ND6 mutation increases HIF-1alpha transcription via the PI3K-Akt/PKC/HDAC pathway, leading to HIF-1alpha protein accumulation in hypoxic tumor cells.

Protein Cage Nanoparticles Bearing the LyP-1 Peptide for Enhanced Imaging of Macrophage-Rich Vascular Lesions

PubMed Central

Uchida, Masaki; Kosuge, Hisanori; Terashima, Masahiro; Willits, Deborah A.; Liepold, Lars O.; Young, Mark J.; McConnell, Michael V.; Douglas, Trevor

2011-01-01

Cage-like protein nano particles are promising platforms for cell and tissue specific targeted delivery of imaging and therapeutic agents. Here, we have successfully modified the 12 nm small heat shock protein from Methanococcus jannaschii (MjHsp) to detect atherosclerotic plaque lesions in a mouse model system. As macrophages are centrally involved in the initiation and progression of atherosclerosis, targeted imaging of macrophages is valuable to assess the biologic status of the blood vessel wall. LyP-1, a nine residue peptide, has been shown to target tumor-associated macrophages. Thus, LyP-1 was genetically incorporated onto the exterior surface of MjHsp, while a fluorescent molecule (Cy5.5) was conjugated on the interior cavity. This bioengineered protein cage, LyP-Hsp, exhibited enhanced affinity to macrophage in vitro. Furthermore, in vivo injection of LyP-Hsp allowed visualization of macrophage-rich murine carotid lesions by in situ and ex vivo fluorescence imaging. These results demonstrate the potential of LyP-1-conjugated protein cages as nano-scale platforms for delivery of imaging agents for the diagnosis of atherosclerosis. PMID:21391720

Polymeric Nano-Micelles as Novel Cargo-Carriers for LY2157299 Liver Cancer Cells Delivery.

PubMed

Hanafy, Nemany Abdelhamid Nemany; Quarta, Alessandra; Ferraro, Marzia Maria; Dini, Luciana; Nobile, Concetta; De Giorgi, Maria Luisa; Carallo, Sonia; Citti, Cinzia; Gaballo, Antonio; Cannazza, Giuseppe; Rinaldi, Rosaria; Giannelli, Gianluigi; Leporatti, Stefano

2018-03-06

LY2157299 (LY), which is very small molecule bringing high cancer diffusion, is a pathway antagonist against TGFβ. LY dosage can be diluted by blood plasma, can be captured by immune system or it might be dissolved during digestion in gastrointestinal tract. The aim of our study is to optimize a "nano-elastic" carrier to avoid acidic pH of gastrointestinal tract, colon alkaline pH, and anti-immune recognition. Polygalacturonic acid (PgA) is not degradable in the gastrointestinal tract due to its insolubility at acidic pH. To avoid PgA solubility in the colon, we have designed its conjugation with Polyacrylic acid (PAA). PgA-PAA conjugation has enhanced their potential use for oral and injected dosage. Following these pre-requisites, novel polymeric nano-micelles derived from PgA-PAA conjugation and loading LY2157299 are developed and characterized. Efficacy, uptake and targeting against a hepatocellular carcinoma cell line (HLF) have also been demonstrated.

On modeling and measuring the temperature of the z ∼ 5 intergalactic medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lidz, Adam; Malloy, Matthew, E-mail: alidz@sas.upenn.edu

2014-06-20

The temperature of the low-density intergalactic medium (IGM) at high redshift is sensitive to the timing and nature of hydrogen and He II reionization, and can be measured from Lyman-alpha (Lyα) forest absorption spectra. Since the memory of intergalactic gas to heating during reionization gradually fades, measurements as close as possible to reionization are desirable. In addition, measuring the IGM temperature at sufficiently high redshifts should help to isolate the effects of hydrogen reionization since He II reionization starts later, at lower redshift. Motivated by this, we model the IGM temperature at z ≳ 5 using semi-numeric models of patchymore » reionization. We construct mock Lyα forest spectra from these models and consider their observable implications. We find that the small-scale structure in the Lyα forest is sensitive to the temperature of the IGM even at redshifts where the average absorption in the forest is as high as 90%. We forecast the accuracy at which the z ≳ 5 IGM temperature can be measured using existing samples of high resolution quasar spectra, and find that interesting constraints are possible. For example, an early reionization model in which reionization ends at z ∼ 10 should be distinguishable—at high statistical significance—from a lower redshift model where reionization completes at z ∼ 6. We discuss improvements to our modeling that may be required to robustly interpret future measurements.« less

Discovery of Scattering Polarization in the Hydrogen Lyα Line of the Solar Disk Radiation

NASA Astrophysics Data System (ADS)

Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.; Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.; Štěpán, J.; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.; Cirtain, J.; De Pontieu, B.; Casini, R.; Carlsson, M.

2017-04-01

There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region other than the magnetic field plays a key role. The magnetism of the TR can only be detected by polarimetric measurements of a few ultraviolet (UV) spectral lines, the Lyα line of neutral hydrogen at 121.6 nm (the strongest line of the solar UV spectrum) being of particular interest given its sensitivity to the Hanle effect (the magnetic-field-induced modification of the scattering line polarization). We report the discovery of linear polarization produced by scattering processes in the Lyα line, obtained with the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket experiment. The Stokes profiles observed by CLASP in quiet regions of the solar disk show that the Q/I and U/I linear polarization signals are of the order of 0.1% in the line core and up to a few percent in the nearby wings, and that both have conspicuous spatial variations with scales of ˜10 arcsec. These observations help constrain theoretical models of the chromosphere-corona TR and extrapolations of the magnetic field from photospheric magnetograms. In fact, the observed spatial variation from disk to limb of polarization at the line core and wings already challenge the predictions from three-dimensional magnetohydrodynamical models of the upper solar chromosphere.

Discovery of Ubiquitous Fast Propagating Intensity Disturbances by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)

NASA Technical Reports Server (NTRS)

Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;

Near-infrared and optical spectroscopy of FSC 10214+4724

NASA Technical Reports Server (NTRS)

Soifer, B. T.; Cohen, J. G.; Armus, L.; Matthews, K.; Neugebauer, G.; Oke, J. B.

1995-01-01

New infrared and optical spectroscopic observations, obtained with the W. M. Keck Telescope, are reported for the highly luminous infrared source FSC 10214+4724. The rest frame optical spectrum shows new emission lines of (Ne III), (Ne V), (O I), (O II), (S II), and He(+), while the rest frame ultraviolet spectrum shows new lines of O IV) + Si IV, N III, N IV), Si II, Ne IV, and possibly N II and (Ne III), as well as clearly showing that Ly-alpha is self-absorbed. The emission-line spectrum is most characteristic of a Seyfert 2 nucleus. The preponderance of spectroscopic evidence strengthens the case for a dust-enshrouded Active galactic nuclei (AGN) powering much or most of the observed luminosity. The various spectral lines lead to a wide range in the inferred reddening and ionization parameter for this system, suggesting that we are viewing several environments through differing extinctions.

Ada Compiler Validation Summary Report: Certificate Number 910705S1. 11192 InterAct Corporation InterAct Ada Mips Cross-Compiler System, Release 2.0 MicroVAX 3100 Cluster = Lockheed Sanders STAR MVP R3000/R3010 board (Bare Machine).

DTIC Science & Technology

1991-07-31

have floating-point type declarations requiring more digits than SYSTEM.MAXDIGITS: C24113L..Y (14 tests) C35705L..Y (14 tests) C357C6L..Y (14 tests...2_147_483_648..2_147_483_647; type FLOAT is digits 6 range -2#l.0#E128.. 2#0.IIIIIIIIIIIIIIIIIIIII#El28; type LONGFLOAT is digits 15 range -2#l.0#EI024.. 2...are instan- tated into libary packages or subprograms.) F-14 Appendix F of the Ada Reference Manual F.8.1. Address Clauses for Variables Address

Investigation of the Chromosphere-Corona Interface with the Upgraded Very High Angular Resolution Ultraviolet Telescope (VAULT2.0)

NASA Astrophysics Data System (ADS)

Vourlidas, Angelos; Beltran, Samuel Tun; Chintzoglou, Georgios; Eisenhower, Kevin; Korendyke, Clarence; Feldman, Ronen; Moser, John; Shea, John; Johnson-Rambert, Mary; McMullin, Don; Stenborg, Guillermo; Shepler, Ed; Roberts, David

2016-03-01

Very high angular resolution ultraviolet telescope (VAULT2.0) is a Lyman-alpha (Lyα; 1216Å) spectroheliograph designed to observe the upper chromospheric region of the solar atmosphere with high spatial (<0.5‧‧) and temporal (8s) resolution. Besides being the brightest line in the solar spectrum, Lyα emission arises at the temperature interface between coronal and chromospheric plasmas and may, hence, hold important clues about the transfer of mass and energy to the solar corona. VAULT2.0 is an upgrade of the previously flown VAULT rocket and was launched successfully on September 30, 2014 from White Sands Missile Range (WSMR). The target was AR12172 midway toward the southwestern limb. We obtained 33 images at 8s cadence at arc second resolution due to hardware problems. The science campaign was a resounding success, with all space and ground-based instruments obtaining high-resolution data at the same location within the AR. We discuss the science rationale, instrument upgrades, and performance during the first flight and present some preliminary science results.

Eclipsing damped Ly α systems in the Sloan Digital Sky Survey Data Release 12

NASA Astrophysics Data System (ADS)

Fathivavsari, H.; Petitjean, P.; Jamialahmadi, N.; Khosroshahi, H. G.; Rahmani, H.; Finley, H.; Noterdaeme, P.; Pâris, I.; Srianand, R.

2018-07-01

We present the results of our automatic search for proximate damped Ly α absorption (PDLA) systems in the quasar spectra from the Sloan Digital Sky Survey Data Release 12. We constrain our search to those PDLAs lying within 1500 km s-1 from the quasar to make sure that the broad DLA absorption trough masks most of the strong Ly α emission from the broad-line region (BLR) of the quasar. When the Ly α emission from the BLR is blocked by these so-called eclipsing DLAs, narrow Ly α emission from the host galaxy could be revealed as a narrow emission line (NEL) in the DLA trough. We define a statistical sample of 399 eclipsing DLAs with log N(H I) ≥ 21.10. We divide our statistical sample into three subsamples based on the strength of the NEL detected in the DLA trough. By studying the stacked spectra of these subsamples, we found that absorptions from high ionization species are stronger in DLAs with stronger NEL in their absorption core. Moreover, absorption from the excited states of species like SIII are also stronger in DLAs with stronger NEL. We also found no correlation between the luminosity of the Ly α NEL and the quasar luminosity. These observations are consistent with a scenario in which the DLAs with stronger NEL are denser and physically closer to the quasar. We propose that these eclipsing DLAs could be the product of the interaction between infalling and outflowing gas. High-resolution spectroscopic observation would be needed to shed some light on the nature of these eclipsing DLAs.

Simulation and Measurement of Stray Light in the CLASP

NASA Technical Reports Server (NTRS)

Narukage, Noriyuki; Kano, Ryohei; Bando, Takamasa; Ishikawa, Ryoko; Kubo, Masahito; Tsuzuki, Toshihiro; Katsukawa, Yukio; Ishikawa, Shin-nosuke; Giono, Gabriel; Suematsu, Yoshinori;

Quasar Feedback at the Peak of Galaxy Formation Epoch

NASA Astrophysics Data System (ADS)

Liu, Guilin; Zakamska, Nadia L.; Strauss, Michael A.; Greene, Jenny E.; Alexandroff, Rachael

2013-02-01

The correlations between properties of supermassive black holes and stellar spheroids in galaxies imply a physical connection between these two components in spite of their vastly different masses and physical scales. Using Gemini GMOS IFU, we demonstrated that powerful ionized gas winds are a ubiquitous feature in luminous radio-quiet obscured z 0.5 quasars. We now plan to extend this discovery to the era of peak galaxy formation and quasar activity - to the epoch when feedback was most prominent and the galaxy vs. black hole correlations were established. We propose a GMOS IFU survey to map the spatial distribution and the kinematics of Ly(alpha) and N sc v 1240Å emission around 5 obscured quasars at z=3-3.4. We will use Ly(alpha) observations to directly probe the effects of ionizing radiation of obscured quasars on their large-scale environments and N sc v observations to look for signatures of unbound quasar-driven outflows. We will observe in the g-band on sub-galactic and galaxy- wide scales (spatial resolution 3-6 kpc, field of view 40times50 kpc^2 at z=3). Obscured quasars likely constitute the majority of the quasar population and may represent the relatively early enshrouded phase of black hole growth; thus, luminous obscured quasars are the most likely sites of quasar ionization- and wind-feedback, as we found at low redshifts. Our proposed GMOS observations will provide a definitive probe of the effects of quasars on their galaxy-wide and large-scale environments close to the peak of galaxy formation epoch.

Far Ultraviolet Spectroscopy of the Intergalactic and Interstellar Absorption Toward 3C 273

NASA Technical Reports Server (NTRS)

Sembach, Kenneth R.; Howk, J. Christopher; Savage, Blair D.; Shull, J. Michael; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)

2001-01-01

We present Far Ultraviolet Spectroscopic Explorer observations of the molecular, neutral atomic, weakly ionized, and highly ionized components of the interstellar and intergalactic material toward the quasar 3C273. We identify Ly-beta absorption in eight of the known intergalactic Ly-alpha absorbers along the sight line with the rest-frame equivalent widths W(sub r)(Ly-alpha) > 50 micro-angstroms. Refined estimates of the H(I) column densities and Doppler parameters (b) of the clouds are presented. We find a range of b = 16-46 km/s. We detect multiple H(I) lines (Ly-beta - Ly-theta) in the 1590 km/s Virgo absorber and estimate logN(H(I)) = 15.85 +/- 0.10, ten times more H(I) than all of the other absorbers along the sight line combined. The Doppler width of this absorber, b = 16 km/s, implies T < 15,000 K. We detect O(VI) absorption at 1015 km/s at the 2-3(sigma) level that may be associated with hot, X-ray emitting gas in the Virgo Cluster. We detect weak C(III) and O(VI) absorption in the IGM at z=0.12007; this absorber is predominantly ionized and has N(H+)/N(H(I)) > 4000/Z, where Z is the metallicity. Strong Galactic interstellar O(VI) is present between -100 and +100 km/s with an additional high-velocity wing containing about 13% of the total O(VI) between +100 and +240 km/s. The Galactic O(VI), N(V), and C(IV) lines have similar shapes, with roughly constant ratios across the -100 to +100 km/s velocity range. The high velocity O(VI) wing is not detected in other species. Much of the interstellar high ion absorption probably occurs within a highly fragmented medium within the Loop IV remnant or in the outer cavity walls of the remnant. Multiple hot gas production mechanisms are required. The broad O(VI) absorption wing likely traces the expulsion of hot gas out of the Galactic disk into the halo. A flux limit of 5.4 x 10(epx -16) erg/sq cm/s on the amount of diffuse O(VI) emission present = 3.5' off the 3C273 sight line combined with the observed O(VI) column density toward 3C273, logN O(VI) = 14.73 +/- 0.04, implies n(sub e) < 0.02/cubic cm and P/k < 11,500/cubic cm for an assumed temperature of 3 x 10(exp 5) K. The elemental abundances in the neutral and weakly-ionized interstellar clouds are similar to those found for other halo clouds. The warm neutral and warm ionized clouds along the sight line have similar dust-phase abundances, implying that the properties of the dust grains in the two types of clouds are similar. Interstellar H2 absorption is present at positive velocities at a level of logN(H2) = 15.71, but is very weak at the velocities of the main column density concentration along the sight line observed in H(I) 21 cm emission.

GREEN PEA GALAXIES REVEAL SECRETS OF Lyα ESCAPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Wang, Junxian; Malhotra, Sangeeta

2016-04-01

We analyze archival Lyα spectra of 12 “Green Pea” galaxies observed with the Hubble Space Telescope, model their Lyα profiles with radiative transfer models, and explore the dependence of the Lyα escape fraction on various properties. Green Pea galaxies are nearby compact starburst galaxies with [O iii] λ5007 equivalent widths (EWs) of hundreds of Å. All 12 Green Pea galaxies in our sample show Lyα lines in emission, with an Lyα EW distribution similar to high-redshift Lyα emitters. Combining the optical and UV spectra of Green Pea galaxies, we estimate their Lyα escape fractions and find correlations between Lyα escape fractionmore » and kinematic features of Lyα profiles. The escape fraction of Lyα in these galaxies ranges from 1.4% to 67%. We also find that the Lyα escape fraction depends strongly on metallicity and moderately on dust extinction. We compare their high-quality Lyα profiles with single H i shell radiative transfer models and find that the Lyα escape fraction anticorrelates with the derived H i column densities. Single-shell models fit most Lyα profiles well, but not the ones with the highest escape fractions of Lyα. Our results suggest that low H i column density and low metallicity are essential for Lyα escape and make a galaxy an Lyα emitter.« less

Nonclinical pharmacology and toxicology of the first biosimilar insulin glargine drug product (BASAGLAR®/ABASAGLAR®) approved in the European Union.

PubMed

Byrd, Richard A; Owens, Rebecca A; Blackbourne, Jamie L; Coutant, David E; Farmen, Mark W; Michael, M Dodson; Moyers, Julie S; Schultze, A Eric; Sievert, Michael K; Tripathi, Niraj K; Vahle, John L

2017-08-01

Basaglar ® /Abasaglar ® (Lilly insulin glargine [LY IGlar]) is a long-acting human insulin analogue drug product granted marketing authorisation as a biosimilar to Lantus ® (Sanofi insulin glargine [SA IGlar]) by the European Medicines Agency. We assessed the similarity of LY IGlar to the reference drug product, European Union-sourced SA IGlar (EU-SA IGlar), using nonclinical in vitro and in vivo studies. No biologically relevant differences were observed for receptor binding affinity at either the insulin or insulin-like growth factor-1 (IGF-1) receptors, or in assays of functional or de novo lipogenic activity. The mitogenic potential of LY IGlar and EU-SA IGlar was similar when tested in both insulin- and IGF-1 receptor dominant cell systems. Repeated subcutaneous daily dosing of rats for 4 weeks with 0, 0.3, 1.0, or 2.0 mg/kg LY IGlar and EU-SA IGlar produced mortalities and clinical signs consistent with severe hypoglycaemia. Glucodynamic profiles of LY IGlar and EU-SA IGlar in satellite animals showed comparable dose-related hypoglycaemia. Severe hypoglycaemia was associated with axonal degeneration of the sciatic nerve; the incidence and severity were low and did not differ between LY IGlar and EU-SA IGlar. These results demonstrated no biologically relevant differences in toxicity between LY IGlar and EU-SA IGlar. Copyright © 2017 Elsevier Inc. All rights reserved.

Jupiter's hydrogen bulge: A Cassini perspective

NASA Astrophysics Data System (ADS)

Melin, Henrik; Stallard, T. S.

2016-11-01

We present observations of H Ly-α and H2 emissions on the body of Jupiter obtained during the Cassini flyby in late 2000 and early 2001. The H Ly-α emission is highly organised by System III longitude and latitude, peaking at a brightness of 22 kR between 90 and 120° longitude. This is known as the H Ly-α 'bulge'. These observations add to a number of previous studies, showing that the feature is very long-lived, present over several decades. We show that there is a strong correlation between the prevailing solar H Ly-α flux (measured at Earth) and the peak brightness of the H Ly-α bulge at Jupiter, which supports the notion that it is primarily driven by solar resonance scatter. The H Ly-α brightness distribution is not aligned with the jovigraphic equator, but is approximately aligned with the particle drift equator of some, but not all, major Jupiter magnetic field models. On the time scale of days, the bulge region appears twice as variable as the non-bulge region. We propose that the electron recombination of H3+ is an important reaction for the generation of the H Ly-α bulge, which requires an enhancement of soft electrons at the location of the bulge. We derive an equatorial H3+ lifetime of 1.6 ± 0.4 h and a corresponding column averaged electron density of 1.7 × 109 m-3.

Chromospheric LAyer SpectroPolarimeter (CLASP2)

NASA Technical Reports Server (NTRS)

Narukage, Noriyuki; Cirtain, Jonathan W.; Ishikawa, Ryoko; Trujillo-Bueno, Javier; De Pontieu, Bart; Kubo, Masahito; Ishikawa, Shinnosuke; Kano, Ryohei; Suematsu, Yoshinori; Yoshida, Masaki;

Lyα Profile, Dust, and Prediction of Lyα Escape Fraction in Green Pea Galaxies

NASA Astrophysics Data System (ADS)

Yang, Huan; Malhotra, Sangeeta; Gronke, Max; Rhoads, James E.; Leitherer, Claus; Wofford, Aida; Jiang, Tianxing; Dijkstra, Mark; Tilvi, V.; Wang, Junxian

2017-08-01

We studied Lyman-α (Lyα) escape in a statistical sample of 43 Green Peas with HST/COS Lyα spectra. Green Peas are nearby star-forming galaxies with strong [O III]λ5007 emission lines. Our sample is four times larger than the previous sample and covers a much more complete range of Green Pea properties. We found that about two-thirds of Green Peas are strong Lyα line emitters with rest-frame Lyα equivalent width > 20 \\mathringA . The Lyα profiles of Green Peas are diverse. The Lyα escape fraction, defined as the ratio of observed Lyα flux to intrinsic Lyα flux, shows anti-correlations with a few Lyα kinematic features—both the blue peak and red peak velocities, the peak separations, and the FWHM of the red portion of the Lyα profile. Using properties measured from Sloan Digital Sky Survey optical spectra, we found many correlations—the Lyα escape fraction generally increases at lower dust reddening, lower metallicity, lower stellar mass, and higher [O III]/[O II] ratio. We fit their Lyα profiles with the H I shell radiative transfer model and found that the Lyα escape fraction is anti-correlated with the best-fit N H I . Finally, we fit an empirical linear relation to predict {f}{esc}{Lyα } from the dust extinction and Lyα red peak velocity. The standard deviation of this relation is about 0.3 dex. This relation can be used to isolate the effect of intergalactic medium (IGM) scatterings from Lyα escape and to probe the IGM optical depth along the line of sight of each z> 7 Lyα emission-line galaxy in the James Webb Space Telescope era.

First Results from Faint Infrared Grism Survey (Figs): First Simultaneous Detection of Ly Alpha Emission and Lyman Break From a Galaxy at Z =7.51

NASA Technical Reports Server (NTRS)

Tilvi, V.; Pirzkal, N.; Malhotra, S.; Finkelstein, S. L.; Rhoads, J. E.; Windhorst, R.; Grogin, N. A.; Koekemoer, A.; Zakamska, N. L.; Ryan, R.;

Eclipsing damped Lyα systems in the Sloan Digital Sky Survey Data Release 12★

NASA Astrophysics Data System (ADS)

Fathivavsari, H.; Petitjean, P.; Jamialahmadi, N.; Khosroshahi, H. G.; Rahmani, H.; Finley, H.; Noterdaeme, P.; Pâris, I.; Srianand, R.

2018-04-01

We present the results of our automatic search for proximate damped Lyα absorption (PDLA) systems in the quasar spectra from the Sloan Digital Sky Survey Data Release 12. We constrain our search to those PDLAs lying within 1500 km s-1 from the quasar to make sure that the broad DLA absorption trough masks most of the strong Lyα emission from the broad line region (BLR) of the quasar. When the Lyα emission from the BLR is blocked by these so-called eclipsing DLAs, narrow Lyα emission from the host galaxy could be revealed as a narrow emission line (NEL) in the DLA trough. We define a statistical sample of 399 eclipsing DLAs with log N(H I) ≥ 21.10. We divide our statistical sample into three subsamples based on the strength of the NEL detected in the DLA trough. By studying the stacked spectra of these subsamples, we found that absorption from high ionization species are stronger in DLAs with stronger NEL in their absorption core. Moreover, absorption from the excited states of species like Si II are also stronger in DLAs with stronger NEL. We also found no correlation between the luminosity of the Lyα NEL and the quasar luminosity. These observations are consistent with a scenario in which the DLAs with stronger NEL are denser and physically closer to the quasar. We propose that these eclipsing DLAs could be the product of the interaction between infalling and outflowing gas. High resolution spectroscopic observation would be needed to shed some light on the nature of these eclipsing DLAs.

The Spectroscopic Properties of Lyα-Emitters at z ˜2.7: Escaping Gas and Photons from Faint Galaxies

NASA Astrophysics Data System (ADS)

Trainor, Ryan F.; Steidel, Charles C.; Strom, Allison L.; Rudie, Gwen C.

2015-08-01

We present a spectroscopic survey of 318 faint ({R}˜ 27, L˜ 0.1{L}*), Lyα-emission-selected galaxies (LAEs) in regions centered on the positions of hyperluminous QSOs (HLQSOs) at 2.5\\lt z\\lt 3. A sample of 32 LAEs with rest-frame optical emission line spectra from Keck/Multi-Object Spectrometer For InfraRed Exploration (MOSFIRE) are used to interpret the LAE spectra in the context of their systemic redshifts. The fields are part of the Keck Baryonic Structure Survey, which includes substantial ancillary multi-wavelength imaging from both the ground and space. From a quantitative analysis of the diverse Lyα spectral morphologies, including line widths, asymmetries, and multi-peaked profiles, we find that peak widths and separations are typically smaller than among samples of more luminous continuum-selected galaxies (Lyman-break galaxies and their analogs; LBGs) at similar redshifts. We find tentative evidence for an association between Lyα spectral morphology and external illumination by the nearby HLQSO. Using the MOSFIRE subsample, we find that the peak of the resolved (R ≈ 1300) Lyα line is shifted by +200 km s-1 with respect to systemic across a diverse set of galaxies including both LAEs and LBGs. We also find a small number of objects with significantly blueshifted Lyα emission, a potential indicator of accreting gas. The Lyα-to-Hα line ratios measured for the MOSFIRE subset suggest that the LAEs in this sample have Lyα escape fractions {f}{esc,{Ly}α } ≈ 30%, significantly higher than typical LBG samples. Using redshifts calibrated by our MOSFIRE sample, we construct composite LAE spectra, finding the first evidence for metal-enriched outflows in such intrinsically faint high-redshift galaxies. These outflows have smaller continuum covering fractions ({f}{{c}}≈ 0.3) and velocities ({v}{ave} ≈ 100-200 km s-1, {v}{max} ≈ 500 km s-1) than those associated with typical LBGs, suggesting that the gas covering fraction is a likely driver of the high Lyα and Ly-continuum escape fractions of LAEs with respect to LBGs. Our results suggest a similar scaling of outflow velocity with star formation rate (SFR) as is observed at lower redshifts ({v}{outflow} ˜ SFR0.25) and indicate that a substantial fraction of gas is ejected with v\\gt {v}{esc}. Further observations, including deep spectroscopy in the observed near-IR, will further probe the evolution and enrichment of these galaxies in the context of their gaseous environments. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

Ultraviolet observation of nova LMC 2012 with STIS/HST

NASA Astrophysics Data System (ADS)

Shore, S. N.; Schwarz, G.; Page, K.; Osborne, J. P.; Starrfield, S.; Walter, F.; Woodward, C. E.; Bode, M.; Ness, J.-U.

2012-05-01

Nova LMC 2012 (ATel #4002, #4043) was observed with STIS on the Hubble Space Telescope on 2012 May 7 (MJD 56055) at three settings with medium resolution (E140M, E230M, with exposure times of 724 sec per setting) covering 1150 - 3000 A. There is only one strong emission line in the entire spectral range: N V 1240 (S/N ~ 15, 0.5 A binning, integrated (not dereddened) flux of 1.2E-13 erg/s/cm^2, FWZI ~ 7500 km/s); the blue wing is blended with Ly-alpha absorption (MW+LMC).

A Doppler dimming determination of coronal outflow velocity

NASA Technical Reports Server (NTRS)

Strachan, Leonard; Kohl, John L.; Weiser, Heinz; Withbroe, George L.; Munro, Richard H.

1993-01-01

Outflow velocities in a polar coronal hole are derived from observations made during a 1982 sounding rocket flight. The velocity results are derived from a Doppler dimming analysis of resonantly scattered H I Ly-alpha. This analysis indicates radial outflow velocities of 217 km/s at 2 solar radii from sun-center with an uncertainty range of 153 to 251 km/s at a confidence level of 67 percent. These results are best characterized as strong evidence for supersonic outflow within 2 solar radii of sun-center in a polar coronal hole. Several means for obtaining improved accuracy in future observations are discussed.

Novel 18F-Labeled κ-Opioid Receptor Antagonist as PET Radiotracer: Synthesis and In Vivo Evaluation of 18F-LY2459989 in Nonhuman Primates.

PubMed

Li, Songye; Cai, Zhengxin; Zheng, Ming-Qiang; Holden, Daniel; Naganawa, Mika; Lin, Shu-Fei; Ropchan, Jim; Labaree, David; Kapinos, Michael; Lara-Jaime, Teresa; Navarro, Antonio; Huang, Yiyun

2018-01-01

The κ-opioid receptor (KOR) has been implicated in depression, addictions, and other central nervous system disorders and, thus, is an important target for drug development. We previously developed several 11 C-labeled PET radiotracers for KOR imaging in humans. Here we report the synthesis and evaluation of 18 F-LY2459989 as the first 18 F-labeled KOR antagonist radiotracer in nonhuman primates and its comparison with 11 C-LY2459989. Methods: The novel radioligand 18 F-LY2459989 was synthesized by 18 F displacement of a nitro group or an iodonium ylide. PET scans in rhesus monkeys were obtained on a small-animal scanner to assess the pharmacokinetic and in vivo binding properties of the ligand. Metabolite-corrected arterial activity curves were measured and used as input functions in the analysis of brain time-activity curves and the calculation of binding parameters. Results: With the iodonium ylide precursor, 18 F-LY2459989 was prepared at high radiochemical yield (36% ± 7% [mean ± SD]), radiochemical purity (>99%), and mean molar activity (1,175 GBq/μmol; n = 6). In monkeys, 18 F-LY2459989 was metabolized at a moderate rate, with a parent fraction of approximately 35% at 30 min after injection. Fast and reversible kinetics were observed, with a regional peak uptake time of less than 20 min. Pretreatment with the selective KOR antagonist LY2456302 (0.1 mg/kg) decreased the activity level in regions with high levels of binding to that in the cerebellum, thus demonstrating the binding specificity and selectivity of 18 F-LY2459989 in vivo. Regional time-activity curves were well fitted by the multilinear analysis 1 kinetic model to derive reliable estimates of regional distribution volumes. With the cerebellum as the reference region, regional binding potentials were calculated and ranked as follows: cingulate cortex > insula > caudate/putamen > frontal cortex > temporal cortex > thalamus, consistent with the reported KOR distribution in the monkey brain. Conclusion: The evaluation of 18 F-LY2459989 in nonhuman primates demonstrated many attractive imaging properties: fast tissue kinetics, specific and selective binding to the KOR, and high specific binding signals. A side-by-side comparison of 18 F-LY2459989 and 11 C-LY2459989 indicated similar kinetic and binding profiles for the 2 radiotracers. Taken together, the results indicated that 18 F-LY2459989 appears to be an excellent PET radiotracer for the imaging and quantification of the KOR in vivo. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Akt mediates 17beta-estradiol and/or estrogen receptor-alpha inhibition of LPS-induced tumor necresis factor-alpha expression and myocardial cell apoptosis by suppressing the JNK1/2-NFkappaB pathway.

PubMed

Liu, Chung-Jung; Lo, Jeng-Fan; Kuo, Chia-Hua; Chu, Chun-Hsien; Chen, Li-Ming; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tzang, Bor-Show; Kuo, Wei-Wen; Huang, Chih-Yang

2009-09-01

Evidence shows that women have lower tumour necrosis factor-alpha (TNF-alpha) levels and lower incidences of heart dysfunction and sepsis-related morbidity and mortality. To identify the cardioprotective effects and precise cellular/molecular mechanisms behind estrogen and estrogen receptors (ERs), we investigated the effects of 17beta-estradiol (E(2)) and estrogen receptor alpha (ERalpha) on LPS-induced apoptosis by analyzing the activation of survival and death signalling pathways in doxycycline (Dox)-inducible Tet-On/ERalpha H9c2 myocardial cells and ERalpha-transfected primary cardiomyocytes overexpressing ERalpha. We found that LPS challenge activated JNK1/2, and then induced IkappaB degradation, NFkappaB activation, TNF-alpha up-regulation and subsequent myocardial apoptotic responses. In addition, treatments involving E(2), membrane-impermeable BSA-E(2) and/or Dox, which induces ERalpha overexpression, significantly inhibited LPS-induced apoptosis by suppressing LPS-up-regulated JNK1/2 activity, IkappaB degradation, NFkappaB activation and pro-apoptotic proteins (e.g. TNF-alpha, active caspases-8, t-Bid, Bax, released cytochrome c, active caspase-9, active caspase-3) in myocardial cells. However, the cardioprotective properties of E(2), BSA-E(2) and ERalpha overexpression to inhibit LPS-induced apoptosis and promote cell survival were attenuated by applying LY294002 (PI3K inhibitor) and PI3K siRNA. These findings suggest that E(2), BSA-E(2) and ERalpha expression exert their cardioprotective effects by inhibiting JNK1/2-mediated LPS-induced TNF-alpha expression and cardiomyocyte apoptosis through activation of Akt.

NASA employee utilizes Virtual Reality (VR) equipment

NASA Image and Video Library

1991-10-28

S91-50404 (1 Nov 1991) --- Bebe Ly of the Information Systems Directorate's (ISD) Software Technology Branch at the Johnson Space Center (JSC) gives virtual reality a try. The stereo video goggles and head[phones allow her to see and hear in a computer-generated world and the gloves allow her to move around and grasp objects. Ly is a member of the team that developed the C Language Integrated production System (CLIPS) which has been instrumental in developing several of the systems to be demonstrated in an upcoming Software Technology Exposition at JSC.

LINKING Lyα AND LOW-IONIZATION TRANSITIONS AT LOW OPTICAL DEPTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaskot, A. E.; Oey, M. S.

2014-08-20

We suggest that low optical depth in the Lyman continuum (LyC) may relate the Lyα emission, C II and Si II absorption, and C II* and Si II* emission seen in high-redshift galaxies. We base this analysis on Hubble Space Telescope Cosmic Origins Spectrograph spectra of four Green Pea (GP) galaxies, which may be analogs of z > 2 Lyα emitters (LAEs). In the two GPs with the strongest Lyα emission, the Lyα line profiles show reduced signs of resonant scattering. Instead, the Lyα profiles resemble the Hα line profiles of evolved star ejecta, suggesting that the Lyα emission originatesmore » from a low column density and similar outflow geometry. The weak C II absorption and presence of non-resonant C II* emission in these GPs support this interpretation and imply a low LyC optical depth along the line of sight. In two additional GPs, weak Lyα emission and strong C II absorption suggest a higher optical depth. These two GPs differ in their Lyα profile shapes and C II* emission strengths, however, indicating different inclinations of the outflows to our line of sight. With these four GPs as examples, we explain the observed trends linking Lyα, C II, and C II* in stacked LAE spectra, in the context of optical depth and geometric effects. Specifically, in some galaxies with strong Lyα emission, a low LyC optical depth may allow Lyα to escape with reduced scattering. Furthermore, C II absorption, C II* emission, and Lyα profile shape can reveal the optical depth, constrain the orientation of neutral outflows in LAEs, and identify candidate LyC emitters.« less

Discovery of Scattering Polarization in the Hydrogen Ly α Line of the Solar Disk Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kano, R.; Narukage, N.; Ishikawa, R.

There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region other than the magnetic field plays a key role. The magnetism of the TR can only be detected by polarimetric measurements of a few ultraviolet (UV) spectral lines, the Ly α line of neutral hydrogen at 121.6 nm (the strongest line of the solar UV spectrum) being of particular interest given its sensitivity to the Hanle effect (the magnetic-field-induced modification ofmore » the scattering line polarization). We report the discovery of linear polarization produced by scattering processes in the Ly α line, obtained with the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) rocket experiment. The Stokes profiles observed by CLASP in quiet regions of the solar disk show that the Q / I and U / I linear polarization signals are of the order of 0.1% in the line core and up to a few percent in the nearby wings, and that both have conspicuous spatial variations with scales of ∼10 arcsec. These observations help constrain theoretical models of the chromosphere–corona TR and extrapolations of the magnetic field from photospheric magnetograms. In fact, the observed spatial variation from disk to limb of polarization at the line core and wings already challenge the predictions from three-dimensional magnetohydrodynamical models of the upper solar chromosphere.« less

Resonant line transfer in a fog: using Lyman-alpha to probe tiny structures in atomic gas

NASA Astrophysics Data System (ADS)

Gronke, Max; Dijkstra, Mark; McCourt, Michael; Peng Oh, S.

2017-11-01

Motivated by observational and theoretical work that suggest very small-scale (≲ 1 pc) structure in the circumgalactic medium of galaxies and in other environments, we study Lyman-α (Lyα) radiative transfer in an extremely clumpy medium with many clouds of neutral gas along the line of sight. While previous studies have typically considered radiative transfer through sightlines intercepting ≲ 10 clumps, we explored the limit of a very large number of clumps per sightline (up to fc 1000). Our main finding is that, for covering factors greater than some critical threshold, a multiphase medium behaves similarly to a homogeneous medium in terms of the emergent Lyα spectrum. The value of this threshold depends on both the clump column density and the movement of the clumps. We estimated this threshold analytically and compare our findings to radiative transfer simulations with a range of covering factors, clump column densities, radii, and motions. Our results suggest that (I) the success in fitting observed Lyα spectra using homogeneous "shell models" (and the corresponding failure of multiphase models) hints at the presence of very small-scale structure in neutral gas, which is in agreement within a number of other observations; and (II) the recurrent problems of reproducing realistic line profiles from hydrodynamical simulations may be due to their inability to resolve small-scale structure, which causes simulations to underestimate the effective covering factor of neutral gas clouds. The movie associated to Fig. B.2 is available at http://www.aanda.org

Thromboelastographic tracings in retired racing greyhounds and in non-greyhound dogs.

PubMed

Vilar, P; Couto, C G; Westendorf, N; Iazbik, C; Charske, J; Marín, L

2008-01-01

Bleeding disorders in patients with normal coagulation test results are frequently reported in Greyhounds. The purpose of this study was to compare Greyhounds to non-Greyhounds by thromboelastography (TEG). TEG parameters in Greyhounds are different from those in non-Greyhounds. Forty-three healthy dogs (28 Greyhounds and 15 non-Greyhounds) based on the results of physical examination, CBC, activated partial thromboplastin time, prothrombin time, fibrinogen, and platelet count. Recalcified citrated native TEGs were performed in both groups; data were compared using Student's, Mann-Whitney, and Pearson's statistical tests. In Greyhounds, mean +/- SD were as follows: R-time 4.3 +/- 1.7 minutes, K-time 3.8 +/- 1.4 minutes, angle (alpha) 50.0 +/- 8.0 degrees , maximum amplitude (MA) 47.6 +/- 5.6 mm, clot strength (G) 4,647 +/- 1,097 dyn/cm2, and percent lysis at 60 minutes (LY60) 2.8 +/- 5.0%. In the non-Greyhounds they were R-time 3.7 +/- 1.6 minutes, K-time 2.5 +/- 0.9 minutes, angle 59.8 +/- 7.0 degrees , MA 53.1 +/- 5.6 mm, G 5,811 +/- 1,256 dyn/cm2, and LY60 3.1 +/- 2.5%. All parameters were significantly different between the groups, except for R-time and LY60. In Greyhounds, clotting kinetics are slower and clot strength are weaker than in non-Greyhounds, supporting the increased tendency to bleed observed after minor trauma or surgical procedures in the breed. The findings may also be attributed to blood viscosity or to the concentration of citrate in the sample (ie, Greyhounds have higher hematocrit and less plasma per unit volume).

Analysis of Ly49 gene transcripts in mature NK cells supports a role for the Pro1 element in gene activation, not gene expression.

PubMed

McCullen, M V; Li, H; Cam, M; Sen, S K; McVicar, D W; Anderson, S K

2016-09-01

The variegated expression of murine Ly49 loci has been associated with the probabilistic behavior of an upstream promoter active in immature cells, the Pro1 element. However, recent data suggest that Pro1 may be active in mature natural killer (NK) cells and function as an enhancer element. To assess directly if Pro1 transcripts are present in mature Ly49-expressing NK cells, RNA-sequencing of the total transcript pool was performed on freshly isolated splenic NK cells sorted for expression of either Ly49G or Ly49I. No Pro1 transcripts were detected from the Ly49a, Ly49c or Ly49i genes in mature Ly49(+) NK cells that contained high levels of Pro2 transcripts. Low levels of Ly49g Pro1 transcripts were found in both Ly49G(+) and Ly49G(-) populations, consistent with the presence of a small population of mature NK cells undergoing Ly49g gene activation, as previously demonstrated by culture of splenic NK cells in interleukin-2. Ly49 gene reporter constructs containing Pro1 failed to show any enhancer activity of Pro1 on Pro2 in a mature Ly49-expressing cell line. Taken together, the results are consistent with Pro1 transcription having a role in gene activation in developing NK, and argue against a role for Pro1 in Ly49 gene transcription by mature NK cells.

Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

PubMed

Chalmers, Iain W; Fitzsimmons, Colin M; Brown, Martha; Pierrot, Christine; Jones, Frances M; Wawrzyniak, Jakub M; Fernandez-Fuentes, Narcis; Tukahebwa, Edridah M; Dunne, David W; Khalife, Jamal; Hoffmann, Karl F

2015-01-01

The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored. Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively) when compared to rising IgG1 levels against sub-surface SmTAL1. Collectively, these results expand the number of SmLy6 proteins found within S. mansoni and specifically demonstrate that surface-associated SmLy6A and SmLy6B elicit immunological responses during infection in endemic communities.

Ly6CHi Blood Monocyte/Macrophage Drive Chronic Inflammation and Impair Wound Healing in Diabetes Mellitus.

PubMed

Kimball, Andrew; Schaller, Matthew; Joshi, Amrita; Davis, Frank M; denDekker, Aaron; Boniakowski, Anna; Bermick, Jennifer; Obi, Andrea; Moore, Bethany; Henke, Peter K; Kunkel, Steve L; Gallagher, Katherine A

2018-05-01

Wound monocyte-derived macrophage plasticity controls the initiation and resolution of inflammation that is critical for proper healing, however, in diabetes mellitus, the resolution of inflammation fails to occur. In diabetic wounds, the kinetics of blood monocyte recruitment and the mechanisms that control in vivo monocyte/macrophage differentiation remain unknown. Here, we characterized the kinetics and function of Ly6C Hi [Lin - (CD3 - CD19 - NK1.1 - Ter-119 - ) Ly6G - CD11b + ] and Ly6C Lo [Lin - (CD3 - CD19 - NK1.1 - Ter-119 - ) Ly6G - CD11b + ] monocyte/macrophage subsets in normal and diabetic wounds. Using flow-sorted tdTomato -labeled Ly6C Hi monocyte/macrophages, we show Ly6C Hi cells transition to a Ly6C Lo phenotype in normal wounds, whereas in diabetic wounds, there is a late, second influx of Ly6C Hi cells that fail transition to Ly6C Lo . The second wave of Ly6C Hi cells in diabetic wounds corresponded to a spike in MCP-1 (monocyte chemoattractant protein-1) and selective administration of anti-MCP-1 reversed the second Ly6C Hi influx and improved wound healing. To examine the in vivo phenotype of wound monocyte/macrophages, RNA-seq-based transcriptome profiling was performed on flow-sorted Ly6C Hi [Lin - Ly6G - CD11b + ] and Ly6C Lo [Lin - Ly6G - CD11b + ] cells from normal and diabetic wounds. Gene transcriptome profiling of diabetic wound Ly6C Hi cells demonstrated differences in proinflammatory and profibrotic genes compared with controls. Collectively, these data identify kinetic and functional differences in diabetic wound monocyte/macrophages and demonstrate that selective targeting of CD11b + Ly6C Hi monocyte/macrophages is a viable therapeutic strategy for inflammation in diabetic wounds. © 2018 American Heart Association, Inc.

Lyα emitters with very large Lyα equivalent widths, EW0(Lyα) ≃ 200-400 Å, at z ˜ 2

NASA Astrophysics Data System (ADS)

Hashimoto, Takuya; Ouchi, Masami; Shimasaku, Kazuhiro; Schaerer, Daniel; Nakajima, Kimihiko; Shibuya, Takatoshi; Ono, Yoshiaki; Rauch, Michael; Goto, Ryosuke

2017-02-01

We present physical properties of spectroscopically confirmed Lyα emitters (LAEs) with very large rest-frame Lyα equivalent widths EW0(Lyα). Although the definition of large EW0(Lyα) LAEs is usually difficult due to limited statistical and systematic uncertainties, we identify six LAEs selected from ˜3000 LAEs at z ˜ 2 with reliable measurements of EW0 (Lyα) ≃ 200-400 Å given by careful continuum determinations with our deep photometric and spectroscopic data. These large EW0(Lyα) LAEs do not have signatures of AGN, but notably small stellar masses of M★ = 107-8 M⊙ and high specific star formation rates (star formation rate per unit galaxy stellar mass) of ˜100 Gyr-1. These LAEs are characterized by the median values of L(Lyα) = 3.7 × 1042 erg s-1 and MUV = -18.0 as well as the blue UV continuum slope of β = -2.5 ± 0.2 and the low dust extinction E(B-V)_* = 0.02^{+0.04}_{-0.02}, which indicate a high median Lyα escape fraction of f_esc^{Lyα }=0.68± 0.30. This large f_esc^{Lyα } value is explained by the low H I column density in the interstellar medium which is consistent with full width at half-maximum (FWHM) of the Lyα line, FWHM(Lyα) = 212 ± 32 km s-1, significantly narrower than those of small EW0(Lyα) LAEs. Based on the stellar evolution models, our observational constraints of the large EW0 (Lyα), the small β, and the rest-frame He II EW imply that at least a half of our large EW0(Lyα) LAEs would have young stellar ages of ≲20 Myr and very low metallicities of Z < 0.02 Z⊙ regardless of the star formation history.

Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens.

PubMed

Wu, Hanyu; Cao, Dainan; Liu, Tongxin; Zhao, Jianmin; Hu, Xiaoxiang; Li, Ning

2015-01-01

Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY) in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies.

Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens

PubMed Central

Wu, Hanyu; Cao, Dainan; Liu, Tongxin; Zhao, Jianmin; Hu, Xiaoxiang; Li, Ning

2015-01-01

Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY) in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies. PMID:26713728

International Conference on Stiff Computation Held at Park City, Utah on April 12, 13 and 14, 1982.

DTIC Science & Technology

1983-05-31

algorithm should be designed which can analyse a system description and find out for the user ~to which class of problems his system belongs... Dove...processors designed to implement aspecific solution process. yrne: IEE floating point chip design " used by INE and others is an example (Xahan)...the...hardware speciaList has designed his computer such that the paraL#L features can be addressed convenientLy and !! ’) efficientLy, and 4;) the software

Lyα and UV Sizes of Green Pea Galaxies

NASA Astrophysics Data System (ADS)

Yang, Huan; Malhotra, Sangeeta; Rhoads, James E.; Leitherer, Claus; Wofford, Aida; Jiang, Tianxing; Wang, Junxian

2017-03-01

Green Peas are nearby analogs of high-redshift Lyα-emitting galaxies (LAEs). To probe their Lyα escape, we study the spatial profiles of Lyα and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope. We extract the spatial profiles of Lyα emission from their 2D COS spectra, and of the UV continuum from both 2D spectra and NUV images. The Lyα emission shows more extended spatial profiles than the UV continuum, in most Green Peas. The deconvolved full width at half maximum of the Lyα spatial profile is about 2-4 times that of the UV continuum, in most cases. Because Green Peas are analogs of high z LAEs, our results suggest that most high-z LAEs probably have larger Lyα sizes than UV sizes. We also compare the spatial profiles of Lyα photons at blueshifted and redshifted velocities in eight Green Peas with sufficient data quality, and find that the blue wing of the Lyα line has a larger spatial extent than the red wing in four Green Peas with comparatively weak blue Lyα line wings. We show that Green Peas and MUSE z = 3-6 LAEs have similar Lyα and UV continuum sizes, which probably suggests that starbursts in both low-z and high-z LAEs drive similar gas outflows illuminated by Lyα light. Five Lyman continuum (LyC) leakers in this sample have similar Lyα to UV continuum size ratios (˜1.4-4.3) to the other Green Peas, indicating that their LyC emissions escape through ionized holes in the interstellar medium.

The Influence of the Photoionizing Radiation Spectrum on Metal-Line Ratios in Ly(alpha) Forest Clouds

NASA Technical Reports Server (NTRS)

Giroux, Mark L.; Shull, J. Michael

1997-01-01

Recent measurements of Si IV/C IV ratios in the high-redshift Ly(alpha) forest (Songaila & Cowie, AJ, 112, 335 (1996a); Savaglio et at., A&A (in press) (1997)) have opened a new window on chemical enrichment and the first generations of stars. However, the derivation of accurate Si/C abundances requires reliable ionization corrections, which are strongly dependent on the spectral shape of the metagalactic ionizing background and on the 'local effects' of hot stars in nearby galaxies. Recent models have assumed power-law quasar ionizing backgrounds plus a decrement at 4 Ryd to account for He II attenuation in intervening clouds. However, we show that realistic ionizing backgrounds based on cosmological radiative transfer models produce more complex ionizing spectra between 1-5 Ryd that are critical to interpreting ions of Si and C. We also make a preliminary investigation of the effects of He II ionization front nonoverlap. Because the attenuation and reemission by intervening clouds enhance Si IV relative to C the observed high Si IV/C IV ratios do not require an unrealistic Si overproduction (Si/C greater than or equal to 3 (Si/C)(solar mass)). If the ionizing spectrum is dominated by 'local effects' from massive stars, even larger Si IV/C IV ratios are possible. However, unless stellar radiation dominates quasars by more than a factor of 10, we confirm the evidence for some Si overproduction by massive stars; values Si/C approx. 2(Si/C)(solar mass) fit the measurements better than solar abundances. Ultimately, an adequate interpretation of the ratios of C IV, Si IV, and C II may require hot, collisionally ionized gas in a multiphase medium.

Filling the Void: A Comprehensive Survey of the Intergalactic Medium at z 1 Using STIS/COS Archival Spectra

NASA Astrophysics Data System (ADS)

Khaire, Vikram

2017-08-01

There exists a large void in our understanding of the intergalactic medium (IGM) at z=0.5-1.5, spanning a significant cosmic time of 4 Gyr. This hole resulted from a paucity of near-UV QSO spectra, which were historically very expensive to obtain. However, with the advent of COS and the HST UV initiative, sufficient STIS/COS NUV spectra have finally become available, enabling the first statistical analyses. We propose a comprehensive study of the z 1 IGM using the Ly-alpha forest of 26 archival QSO spectra. This analysis will: (1) measure the distribution of HI absorbers to several percent precision down to log NHI < 13 to test our model of the IGM, and determine the extragalactic UV background (UVB) at that epoch; (2) measure the Ly-alpha forest power spectrum to 12%, providing another precision test of LCDM and our theory of the IGM; (3) measure the thermal state of the IGM, which reflects the balance of heating (photoheating, HI/HeII reionization) and cooling (Hubble expansion) of cosmic baryons, and directly verify the predicted cooldown of IGM gas after reionization for the first time; (4) generate high-quality reductions, coadds, and continuum fits that will be released to the public to enable other science cases. These results, along with our state-of-the-art hydrodynamical simulations, and theoretical models of the UVB, will fill the 4 Gyr hole in our understanding of the IGM. When combined with existing HST and ground-based data from lower and higher z, they will lead to a complete, empirical description of the IGM from HI reionization to the present, spanning more than 10 Gyr of cosmic history, adding substantially to Hubble's legacy of discovery on the IGM.

New Constraints on the Hard Ionizing Photon Budget and the Lifetime and Obscuration of Quasars During the Epoch of Helium Reionization

NASA Astrophysics Data System (ADS)

Davies, Frederick

2017-08-01

The epoch of helium reionization was a major milestone in the history of the Universe, a direct consequence of supermassive black hole growth and the cumulative output of hard ionizing photons by quasars. Our observations of the He II Ly-alpha forest with HST/COS in 26 quasar sightlines show strong fluctuations at z 3, consistent with our state-of-the-art simulations of the He II reionization epoch. However, our detection of transmission at z > 3.5 is inconsistent with all He II reionization models. Resolving this puzzle requires an extensive parameter study of He II reionization, which we propose to carry out using our fast, efficient simulations. The He II Ly-alpha forest is also sensitive to the effect of quasar radiation illuminating the intergalactic medium, known as the proximity effect. We have performed an ambitious ground-based imaging and spectroscopic survey for z 3 quasars in the foreground of HeII sightlines observed with HST/COS, and statistically detected the transverse proximity effect for the first time. The strength of this effect depends on both the quasar lifetime and the opening angle of quasar emission (or the fraction of obscured quasars), and we propose to use our He II reionization simulations to interpret this new measurement. Finally, the line-of-sight proximity effect due to the background quasar provides an independent constraint on the quasar lifetime. Our preliminary comparison of He II spectra to our radiative transfer simulations suggests a quasar lifetime > 10 Myr. We propose to use our He II reionization simulations to model this diverse set of observations and fully capitalize on the far-UV legacy of HST.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saunders, Will; Smedley, Scott; Gillingham, Peter

We present Simulated Annealing fiber-to-target allocation simulations for the proposed DESI and 4MOST massively multiplexed spectroscopic surveys, and for both Poisson and realistically clustered mock target samples. We simulate both Echidna and theta-phi actuator designs, including the restrictions caused by the physical actuator characteristics during repositioning. For DESI, with theta-phi actuators, used in 5 passes over the sky for a mock ELG/LRG/QSO sample, with matched fiber and target densities, a total target allocation yield of 89.3% was achieved, but only 83.7% for the high-priority Ly-alpha QSOs. If Echidna actuators are used with the same pitch and number of passes, themore » yield increases by 5.7% and 16% respectively. Echidna also allows a factor-of-two increase in the number of close Ly-alpha QSO pairs that can be observed. Echidna spine tilt causes a variable loss of throughput, with average loss being the same as the loss at the rms tilt. With a natural tilt minimization scheme, we find an rms tilt always close to 0.58 x maximum. There is an additional but much smaller defocus loss, equivalent to an average defocus of 30microns. These tilt losses offset the gains in yield for Echidna, but because the survey strategy is driven by the higher priority targets, a clear survey speed advantage remains. For 4MOST, high and low latitude sample mock catalogs were supplied by the 4MOST team, and allocations were carried out with the proposed Echidna-based positioner geometry. At high latitudes, the resulting target completeness was 85.3% for LR targets and 78.9% for HR targets. At low latitude, the target completeness was 93.9% for LR targets and 71.2% for HR targets.« less

[Histopathological and immunohistochemical studies on mucous cysts].

PubMed

Kuroda, N

1989-01-01

The present study investigated the histopathology, histochemistry of mucopolysaccharides, and immunohistochemistry of oral mucous cysts. The materials were obtained from ninety cases that were histopathologically diagnosed as oral mucous cysts at the Department of Oral Pathology, Meikai University School of Dentistry. Mucopolysaccharide staining was done with PAS, alcian blue (AB, pH 2.5) and high iron diamine (HID). Immunohistochemical studies were focused on secretory component (SC), lactoferrin (Lf), alpha-amylase (Am), IgA, lysozyme (Ly), and keratin (Kr). The following results were obtained: 1. Histopathological findings. (1) Retention and/or retention-like type cysts occurred in was twenty-six cases and the extravasation type in sixty-four cases. (2) Cases showing epithelial lining of the cystic wall were only eight in number, and many cystic walls were contained granulation tissue (fifty cases). (3) As for inflammation of the cystic wall, the degree was slight, and infiltrated cells were mainly macrophages (so-called mucinophages) and lymphocytes. (4) Regarding adjoining salivary glands, acinar cells showed atrophic changes, and hypertrophy of mucous acinar cells was evident. Many ducts showed dilatation, and stromal connective tissue showed fibrosis and hyalinization. 2. Histochemical findings on mucopolysaccharides. (1) Mucous materials in cystic cavity, mucous acinar cells, and secretory materials in ductal lumens were intensely stained by PAS and AB. But stainability with AB was less than that with PAS staining. Serous acinar cells and ductal epithelium were negative to PAS and AB staining. (2) Stainability of the above with HID was less than at with PAS or AB. Cystic walls were not stained by HID. Mucous acinar cells reactive with HID were intensely stained, but the number of the positive cells was limited when compared with the numbers of PAS-and AB-positive cells. 3. Immunohistochemical findings. (1) As for mucous materials in the cystic cavity, reactions for Sc, Am, IgA, and Ly were all positive, whereas those for Lf and Kr were negative. (2) Staining of cystic walls was generally weak: the walls were negative for IgA, Ly and Kr showed and borderline or slightly positive for Sc, Lf, and Am. (3) Mucous acinar cells were negative for all markers examined in this study, but serous acinar cells and/or demilunes were markedly positive for Sc, Ly, and Am. (4) In ductal epithelial cells, Ly and Kr were negative, but IgA was borderline or slightly positive. Sc and Am gave intensely positive staining. (5) Secretory materials in ductal lumens, Sc were intensely positive for Lf, and Ly; slightly or moderately positive for IgA; and slightly positive or negative for Am.(ABSTRACT TRUNCATED AT 400 WORDS)

The Hubble Space Telescope Quasar Absorption Line Key Project: The Unusual Absorption-Line System in the Spectrum of PG 2302+029--Ejected or Intervening?

NASA Technical Reports Server (NTRS)

Jannuzi, B. T.; Hartig, G. F.; Kirhakos, S.; Sargent, W. L. W.; Turnshek, D. A.; Weymann, R. J.; Bahcall, J. N.; Bergeron, J.; Boksenberg, A.; Savage, B. D.;

Structural Analysis and Deletion Mutagenesis Define Regions of QUIVER/SLEEPLESS that Are Responsible for Interactions with Shaker-Type Potassium Channels and Nicotinic Acetylcholine Receptors

PubMed Central

Wu, Meilin; Liu, Clifford Z.; Joiner, William J.

2016-01-01

Ly6 proteins are endogenous prototoxins found in most animals. They show striking structural and functional parallels to snake α-neurotoxins, including regulation of ion channels and cholinergic signaling. However, the structural contributions of Ly6 proteins to regulation of effector molecules is poorly understood. This question is particularly relevant to the Ly6 protein QUIVER/SLEEPLESS (QVR/SSS), which has previously been shown to suppress excitability and synaptic transmission by upregulating potassium (K) channels and downregulating nicotinic acetylcholine receptors (nAChRs) in wake-promoting neurons to facilitate sleep in Drosophila. Using deletion mutagenesis, co-immunoprecipitations, ion flux assays, surface labeling and confocal microscopy, we demonstrate that only loop 2 is required for many of the previously described properties of SSS in transfected cells, including interactions with K channels and nAChRs. Collectively our data suggest that QVR/SSS, and by extension perhaps other Ly6 proteins, target effector molecules using limited protein motifs. Mapping these motifs may be useful in rational design of drugs that mimic or suppress Ly6-effector interactions to modulate nervous system function. PMID:26828958

Ly49Q, a member of the Ly49 family that is selectively expressed on myeloid lineage cells and involved in regulation of cytoskeletal architecture

PubMed Central

Toyama-Sorimachi, Noriko; Tsujimura, Yusuke; Maruya, Mikako; Onoda, Atsuko; Kubota, Toshiyuki; Koyasu, Shigeo; Inaba, Kayo; Karasuyama, Hajime

2004-01-01

Here, we identified and characterized a Ly49 family member, designated as Ly49Q. The Ly49q gene encodes a 273-aa protein with an immunoreceptor tyrosine-based inhibitory motif (ITIM) at the N terminus of its cytoplasmic domain. We show that the ITIM of Ly49Q can recruit SHP-2 and SHP-1 in a tyrosine phosphorylation-dependent manner. In contrast to other known members of the Ly49 family, Ly49Q was found not to be expressed on NK1.1+ cells, but instead was detectable on virtually all Gr-1+ cells, such as myeloid precursors in bone marrow. Monocytes/macrophages also expressed low levels of Ly49Q, and the expression was enhanced by the treatment of cells with IFN-γ. Treatment of activated macrophages with anti-Ly49Q mAb induced rapid formation of polarized actin structures, showing filopodia-like structure on one side and lamellipodial-like structure on the other side. A panel of proteins became tyrosine-phosphorylated in myeloid cells when treated with the mAb. Induction of the phosphorylation depends on the ITIM of Ly49Q. Thus, Ly49Q has unique features different from other known Ly49 family members and appears to be involved in regulation of cytoskeletal architecture of macrophages through ITIM-mediated signaling. PMID:14732700

Analysis of Pulsating Components in the Eclipsing Binary Systems LT Herculis, RZ Microscopii, LY Puppis, V632 Scorpii, and V638 Scorpii

NASA Astrophysics Data System (ADS)

Streamer, M.; Bohlsen, T.; Ogmen, Y.

2016-06-01

Eclipsing binary stars are especially valuable for studies of stellar evolution. If pulsating components are also present then the stellar interior can be studied using asteroseismology techniques. We present photometric data and the analysis of the delta Scuti pulsations that we have discovered in five eclipsing binary systems. The systems are: LT Herculis, RZ Microscopii, LY Puppis, V632 Scorpii and V638 Scorpii. The dominant pulsation frequencies range between 13 - 29 cycles per day with semi-amplitudes of 4 - 20 millimagnitudes.

Ly α and UV Sizes of Green Pea Galaxies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Wang, Junxian; Malhotra, Sangeeta

Green Peas are nearby analogs of high-redshift Ly α -emitting galaxies (LAEs). To probe their Ly α escape, we study the spatial profiles of Ly α and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope . We extract the spatial profiles of Ly α emission from their 2D COS spectra, and of the UV continuum from both 2D spectra and NUV images. The Ly α emission shows more extended spatial profiles than the UV continuum, in most Green Peas. The deconvolved full width at half maximum of the Lymore » α spatial profile is about 2–4 times that of the UV continuum, in most cases. Because Green Peas are analogs of high z LAEs, our results suggest that most high- z LAEs probably have larger Ly α sizes than UV sizes. We also compare the spatial profiles of Ly α photons at blueshifted and redshifted velocities in eight Green Peas with sufficient data quality, and find that the blue wing of the Ly α line has a larger spatial extent than the red wing in four Green Peas with comparatively weak blue Ly α line wings. We show that Green Peas and MUSE z = 3–6 LAEs have similar Ly α and UV continuum sizes, which probably suggests that starbursts in both low- z and high- z LAEs drive similar gas outflows illuminated by Ly α light. Five Lyman continuum (LyC) leakers in this sample have similar Ly α to UV continuum size ratios (∼1.4–4.3) to the other Green Peas, indicating that their LyC emissions escape through ionized holes in the interstellar medium.« less

Cost effectiveness of facility-based care, home-based care and mobile clinics for provision of antiretroviral therapy in Uganda.

PubMed

Babigumira, Joseph B; Sethi, Ajay K; Smyth, Kathleen A; Singer, Mendel E

2009-01-01

Stakeholders in HIV/AIDS care currently use different programmes for provision of antiretroviral therapy (ART) in Uganda. It is not known which of these represents the best value for money. To compare the cost effectiveness of home-based care (HBC), facility-based care (FBC) and mobile clinic care (MCC) for provision of ART in Uganda. Incremental cost-effectiveness analysis was performed using decision and Markov modeling of adult AIDS patients in WHO Clinical Stage 3 and 4 from the perspective of the Ugandan healthcare system. The main outcome measures were cost (year 2008 values), life expectancy in life-years (LY) and the incremental cost-effectiveness ratio (ICER) measured as cost per QALY or LY gained over 10 years. Ten-year mean undiscounted life expectancy was lowest for FBC (3.6 LY), followed by MCC (4.3 LY) and highest for HBC (5.3 LY), while the mean discounted QALYs were also lowest for FBC (2.3), followed by MCC (2.9) and highest for HBC (3.7). The 10-year mean costs per patient were lowest for FBC ($US3212), followed by MCC ($US4782) and highest for HBC ($US7033). The ICER was lower for MCC versus FBC ($US2241 per LY and $US2615 per QALY) than for HBC versus MCC ($US2251 per LY and $US2814 per QALY). FBC remained cost effective in univariate and probabilistic sensitivity analyses. FBC appears to be the most cost-effective programme for provision of ART in Uganda. This analysis supports the implementation of FBC for scale-up and sustainability of ART in Uganda. HBC and MCC would be competitive only if there is increased access, increased adherence or reduced cost.

PI3K/Akt inhibitor LY294002 potentiates homoharringtonine antimyeloma activity in myeloma cells adhered to stromal cells and in SCID mouse xenograft.

PubMed

Chen, Ping; Wen, Xiaofang; Wang, Bin; Hou, Diyu; Zou, Hong; Yuan, Qin; Yang, Hui; Xie, Jieqiong; Huang, Huifang

2018-05-01

Homoharringtonine (HHT) is a known anti-leukemia drug that inhibits multiple myeloma (MM) cells both in vitro and in vivo. Our prior study demonstrated that the potency of HHT in MM cells was compromised significantly when myeloma cells were co-cultured with BM stromal cells. This study aimed to investigate whether PI3K/Akt inhibitor LY294002 could potentiate the antimyeloma activity of HHT against MM cells adhered to BM stromal cells and in vivo xenograft models. A co-culture system composed of MM cells and human stromal cells was employed to mimic MM cells in bone marrow niche. The inhibitory and pro-apoptotic effect of HHT and LY294002 was determined by CCK-8 assay or flow cytometry. Expression of PI3K/Akt signaling molecules and anti-apoptotic protein myeloid cell leukemia-1 (Mcl-1) was assessed by western blot analysis and/or reverse transcription real-time quantitative PCR (RT-qPCR). MM xenografts were used to evaluate antitumor effect of combined therapy with HHT and LY294002. Adhesion to BM stromal cells rendered MM cells resistant to HHT whereas silencing Mcl-1 partly reversed the resistance. LY294002 induced apoptosis in MM cells and potentiated the antimyeloma effects of HHT by inhibiting the PI3K/Akt signal pathway which was abnormally activated during adhesion. LY294002 also enhanced the antimyeloma effect of HHT in in vivo xenograft models. These findings suggest that activation of PI3K/Akt signal pathway was responsible for the resistance to HHT in MM cells adhered to stromal cells. LY294002 can potentiate the antimyeloma activity of HHT both in vitro and in vivo, which may represent a new clinical treatment in MM.

Cost Effectiveness of Facility-Based Care, Home-Based Care and Mobile Clinics for Provision of Antiretroviral Therapy in Uganda

PubMed Central

Babigumira, Joseph B.; Sethi, Ajay K.; Smyth, Kathleen A.; Singer, Mendel E.

2012-01-01

Background Stakeholders in HIV/AIDS care currently use different programmes for provision of antiretroviral therapy (ART) in Uganda. It is not known which of these represents the best value for money. Objective To compare the cost effectiveness of home-based care (HBC), facility-based care (FBC) and mobile clinic care (MCC) for provision of ART in Uganda. Methods Incremental cost-effectiveness analysis was performed using decision and Markov modeling of adult AIDS patients in WHO Clinical Stage 3 and 4 from the perspective of the Ugandan healthcare system. The main outcome measures were cost (year 2008 values), life expectancy in life-years (LY) and the incremental cost-effectiveness ratio (ICER) measured as cost per QALY or LY gained over 10 years. Results Ten-year mean undiscounted life expectancy was lowest for FBC (3.6 LY), followed by MCC (4.3 LY) and highest for HBC (5.3 LY), while the mean discounted QALYs were also lowest for FBC (2.3), followed by MCC (2.9) and highest for HBC (3.7). The 10-year mean costs per patient were lowest for FBC ($US3212), followed by MCC ($US4782) and highest for HBC ($US7033). The ICER was lower for MCC versus FBC ($US2241 per LY and $US2615 per QALY) than for HBC versus MCC ($US2251 per LY and $US2814 per QALY). FBC remained cost effective in univariate and probabilistic sensitivity analyses. Conclusions FBC appears to be the most cost-effective programme for provision of ART in Uganda. This analysis supports the implementation of FBC for scale-up and sustainability of ART in Uganda. HBC and MCC would be competitive only if there is increased access, increased adherence or reduced cost. PMID:19888795

Effects of the novel endocannabinoid uptake inhibitor, LY2183240, on fear-potentiated startle and alcohol-seeking behaviors in mice selectively bred for high alcohol preference.

PubMed

Powers, Matthew S; Barrenha, Gustavo D; Mlinac, Nate S; Barker, Eric L; Chester, Julia A

2010-12-01

Alcohol-use disorders often occur together with anxiety disorders in humans which may be partly due to common inherited genetic factors. Evidence suggests that the endocannabinoid system (ECS) is a promising therapeutic target for the treatment of individuals with anxiety and/or alcohol-use disorders. The present study assessed the effects of a novel endocannabinoid uptake inhibitor, LY2183240, on anxiety- and alcohol-seeking behaviors in a unique animal model that may represent increased genetic risk to develop co-morbid anxiety and alcohol-use disorders in humans. Mice selectively bred for high alcohol preference (HAP) show greater fear-potentiated startle (FPS) than mice selectively bred for low alcohol preference (LAP). We examined the effects of LY2183240 on the expression of FPS in HAP and LAP mice and on alcohol-induced conditioned place preference (CPP) and limited-access alcohol drinking behavior in HAP mice. Repeated administration of LY2183240 (30 mg/kg) reduced the expression of FPS in HAP but not LAP mice when given prior to a second FPS test 48 h after fear conditioning. Both the 10 and 30 mg/kg doses of LY2183240 enhanced the expression of alcohol-induced CPP and this effect persisted in the absence of the drug. LY2183240 did not alter limited-access alcohol drinking behavior, unconditioned startle responding, or locomotor activity. These findings suggest that ECS modulation influences both conditioned fear and conditioned alcohol reward behavior. LY2183240 may be an effective pharmacotherapy for individuals with anxiety disorders, such as post-traumatic stress disorder, but may not be appropriate for individuals with co-morbid anxiety and alcohol-use disorders.

Mechanisms of Inhibition and Potentiation of α4β2 Nicotinic Acetylcholine Receptors by Members of the Ly6 Protein Family*

PubMed Central

Wu, Meilin; Puddifoot, Clare A.; Taylor, Palmer; Joiner, William J.

2015-01-01

α4β2 nicotinic acetylcholine receptors (nAChRs) are abundantly expressed throughout the central nervous system and are thought to be the primary target of nicotine, the main addictive substance in cigarette smoking. Understanding the mechanisms by which these receptors are regulated may assist in developing compounds to selectively interfere with nicotine addiction. Here we report previously unrecognized modulatory properties of members of the Ly6 protein family on α4β2 nAChRs. Using a FRET-based Ca2+ flux assay, we found that the maximum response of α4β2 receptors to agonist was strongly inhibited by Ly6h and Lynx2 but potentiated by Ly6g6e. The mechanisms underlying these opposing effects appear to be fundamentally distinct. Receptor inhibition by Lynx2 was accompanied by suppression of α4β2 expression at the cell surface, even when assays were preceded by chronic exposure of cells to an established chaperone, nicotine. Receptor inhibition by Lynx2 also was resistant to pretreatment with extracellular phospholipase C, which cleaves lipid moieties like those that attach Ly6 proteins to the plasma membrane. In contrast, potentiation of α4β2 activity by Ly6g6e was readily reversible by pretreatment with phospholipase C. Potentiation was also accompanied by slowing of receptor desensitization and an increase in peak currents. Collectively our data support roles for Lynx2 and Ly6g6e in intracellular trafficking and allosteric potentiation of α4β2 nAChRs, respectively. PMID:26276394

Mechanisms of inhibition and potentiation of α4β2 nicotinic acetylcholine receptors by members of the Ly6 protein family.

PubMed

Wu, Meilin; Puddifoot, Clare A; Taylor, Palmer; Joiner, William J

2015-10-02

α4β2 nicotinic acetylcholine receptors (nAChRs) are abundantly expressed throughout the central nervous system and are thought to be the primary target of nicotine, the main addictive substance in cigarette smoking. Understanding the mechanisms by which these receptors are regulated may assist in developing compounds to selectively interfere with nicotine addiction. Here we report previously unrecognized modulatory properties of members of the Ly6 protein family on α4β2 nAChRs. Using a FRET-based Ca(2+) flux assay, we found that the maximum response of α4β2 receptors to agonist was strongly inhibited by Ly6h and Lynx2 but potentiated by Ly6g6e. The mechanisms underlying these opposing effects appear to be fundamentally distinct. Receptor inhibition by Lynx2 was accompanied by suppression of α4β2 expression at the cell surface, even when assays were preceded by chronic exposure of cells to an established chaperone, nicotine. Receptor inhibition by Lynx2 also was resistant to pretreatment with extracellular phospholipase C, which cleaves lipid moieties like those that attach Ly6 proteins to the plasma membrane. In contrast, potentiation of α4β2 activity by Ly6g6e was readily reversible by pretreatment with phospholipase C. Potentiation was also accompanied by slowing of receptor desensitization and an increase in peak currents. Collectively our data support roles for Lynx2 and Ly6g6e in intracellular trafficking and allosteric potentiation of α4β2 nAChRs, respectively. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Activation of peroxisome proliferator-activated receptor beta/delta induces lung cancer growth via peroxisome proliferator-activated receptor coactivator gamma-1alpha.

PubMed

Han, Shouwei; Ritzenthaler, Jeffrey D; Sun, Xiaojuan; Zheng, Ying; Roman, Jesse

2009-03-01

We previously demonstrated that a selective agonist of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta), GW501516, stimulated human non-small cell lung carcinoma (NSCLC) growth, partly through inhibition of phosphatase and tensin homolog deleted on chromosome 10 expression. Here, we show that GW501516 also decreases the phosphorylation of AMP-activated protein kinase alpha (AMPKalpha), a major regulator of energy metabolism. This was mediated through specific activation of PPARbeta/delta, as a PPARbeta/delta small interfering RNA inhibited the effect. However, AMPKalpha did not mediate the growth-promoting effects of GW501516, as silencing of AMPKalpha did not inhibit GW501516-induced cell proliferation. Instead, we found that GW501516 stimulated peroxisome proliferator-activated receptor coactivator gamma (PGC)-1alpha, which activated the phosphatidylinositol 3 kinase (PI3-K)/Akt mitogenic pathway. An inhibitor of PI3-K, LY294002, had no effect on PGC-1alpha, consistent with PGC-1alpha being upstream of PI3-K/Akt. Of note, an activator of AMPKalpha, 5-amino-4-imidazole carboxamide riboside, inhibited the growth-promoting effects of GW501516, suggesting that although AMPKalpha is not responsible for the mitogenic effects of GW501516, its activation can oppose these events. This study unveils a novel mechanism by which GW501516 and activation of PPARbeta/delta stimulate human lung carcinoma cell proliferation, and suggests that activation of AMPKalpha may oppose this effect.

Noradrenaline and alpha-adrenergic signaling induce the hsp70 gene promoter in mollusc immune cells.

PubMed

Lacoste, A; De Cian, M C; Cueff, A; Poulet, S A

2001-10-01

Expression of heat shock proteins (hsp) is a homeostatic mechanism induced in both prokaryotic and eukaryotic cells in response to metabolic and environmental insults. A growing body of evidence suggests that in mammals, the hsp response is integrated with physiological responses through neuroendocrine signaling. In the present study, we have examined the effect of noradrenaline (NA) on the hsp70 response in mollusc immune cells. Oyster and abalone hemocytes transfected with a gene construct containing a gastropod hsp70 gene promoter linked to the luciferase reporter-gene were exposed to physiological concentrations of NA, or to various alpha- and beta-adrenoceptor agonists and antagonists. Results show that NA and alpha-adrenergic stimulations induced the expression of luciferase in transfected mollusc immunocytes. Furthermore, exposure of hemocytes to NA or to the alpha-adrenoceptor agonist phenylephrine (PE) resulted in the expression of the inducible isoform of the hsp70 protein. Pertussis toxin (PTX), the phospholipase C (PLC) inhibitor U73122, the protein kinase C (PKC) inhibitor calphostin C, the Ca(2+)-dependent PKC inhibitor Gö 6976 and the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor LY294002 blocked the PE-mediated induction of the hsp70 gene promoter. These results suggest that alpha-adrenergic signaling induces the transcriptionnal upregulation of hsp70 in mollusc hemocytes through a PTX-sensitive G-protein, PLC, Ca(2+)-dependent PKC and PI 3-kinase. Thus, a functional link exists between neuroendocrine signaling and the hsp70 response in mollusc immune cells.

Internal Representation and Memory Formation of Odor Preference Based on Oscillatory Activities in a Terrestrial Slug

ERIC Educational Resources Information Center

Sekiguchi, Tatsuhiko; Furudate, Hiroyuki; Kimura, Tetsuya

2010-01-01

The terrestrial slug "Limax" exhibits a highly developed ability to learn odors with a small nervous system. When a fluorescent dye, Lucifer Yellow (LY), is injected into the slug's body cavity after odor-taste associative conditioning, a group of neurons in the procerebral (PC) lobe, an olfactory center of the slug, is labeled by LY. We examined…

PSGL-1 is highly expressed on Ly-6Chi monocytes and a major determinant for Ly-6Chi monocyte recruitment to sites of atherosclerosis in mice

PubMed Central

An, Guangyu; Wang, Huan; Tang, Rong; Yago, Tadayuki; McDaniel, J. Michael; McGee, Samuel; Huo, Yuqing; Xia, Lijun

2008-01-01

Background Ly-6Chi monocytes are key contributors to atherosclerosis in mice. However, how Ly-6Chi monocytes selectively accumulate in atherosclerotic lesions is largely unknown. Monocyte homing to sites of atherosclerosis is primarily initiated by rolling on P- and E-selectin expressed on endothelium. We hypothesize that P-selectin glycoprotein ligand-1 (PSGL-1), the common ligand of P- and E-selectin on leukocytes, contributes to the preferential homing of Ly-6Chi monocytes to atherosclerotic lesions. Methods and Results To test this hypothesis, we examined the expression and function of PSGL-1 on Ly-6Chi and Ly-6Clo monocytes from wild-type mice, ApoE-/- mice, and mice lacking both ApoE and PSGL-1 genes (ApoE-/-/PSGL-1-/-). We found that Ly-6Chi monocytes expressed a higher level of PSGL-1, and had enhanced binding to fluid-phase P- and E-selectin, compared to Ly-6Clo monocytes. Under in vitro flow conditions, more Ly-6Chi monocytes rolled on P-, E-, and L-selectin at slower velocities than Ly-6Clo cells. In an ex vivo perfused carotid artery model, Ly-6Chi monocytes interacted preferentially with atherosclerotic endothelium compared with Ly-6Clo monocytes in a PSGL-1-dependent manner. In vivo, ApoE-/- mice lacking PSGL-1 had impaired Ly-6Chi monocyte recruitment to atherosclerotic lesions. Moreover, ApoE-/-/PSGL-1-/- mice exhibited significantly reduced monocyte infiltration in wire injury-induced neointima and in atherosclerotic lesions. ApoE-/-/PSGL-1-/- mice also developed smaller neointima and atherosclerotic plaques. Conclusions These data indicate that PSGL-1 is a new marker for Ly-6Chi monocytes and a major determinant for Ly-6Chi cell recruitment to sites of atherosclerosis in mice. PMID:18519846

The Kinematics of Multiple-peaked Lyα Emission in Star-forming Galaxies at z ~ 2-3

NASA Astrophysics Data System (ADS)

Kulas, Kristin R.; Shapley, Alice E.; Kollmeier, Juna A.; Zheng, Zheng; Steidel, Charles C.; Hainline, Kevin N.

2012-01-01

We present new results on the Lyα emission-line kinematics of 18 z ~ 2-3 star-forming galaxies with multiple-peaked Lyα profiles. With our large spectroscopic database of UV-selected star-forming galaxies at these redshifts, we have determined that ~30% of such objects with detectable Lyα emission display multiple-peaked emission profiles. These profiles provide additional constraints on the escape of Lyα photons due to the rich velocity structure in the emergent line. Despite recent advances in modeling the escape of Lyα from star-forming galaxies at high redshifts, comparisons between models and data are often missing crucial observational information. Using Keck II NIRSPEC spectra of Hα (z ~ 2) and [O III]λ5007 (z ~ 3), we have measured accurate systemic redshifts, rest-frame optical nebular velocity dispersions, and emission-line fluxes for the objects in the sample. In addition, rest-frame UV luminosities and colors provide estimates of star formation rates and the degree of dust extinction. In concert with the profile sub-structure, these measurements provide critical constraints on the geometry and kinematics of interstellar gas in high-redshift galaxies. Accurate systemic redshifts allow us to translate the multiple-peaked Lyα profiles into velocity space, revealing that the majority (11/18) display double-peaked emission straddling the velocity-field zero point with stronger red-side emission. Interstellar absorption-line kinematics suggest the presence of large-scale outflows for the majority of objects in our sample, with an average measured interstellar absorption velocity offset of langΔv absrang = -230 km s-1. A comparison of the interstellar absorption kinematics for objects with multiple- and single-peaked Lyα profiles indicate that the multiple-peaked objects are characterized by significantly narrower absorption line widths. We compare our data with the predictions of simple models for outflowing and infalling gas distributions around high-redshift galaxies. While popular "shell" models provide a qualitative match with many of the observations of Lyα emission, we find that in detail there are important discrepancies between the models and data, as well as problems with applying the framework of an expanding thin shell of gas to explain high-redshift galaxy spectra. Our data highlight these inconsistencies, as well as illuminating critical elements for success in future models of outflow and infall in high-redshift galaxies. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

ADAMTS1 inhibits lymphangiogenesis by attenuating phosphorylation of the lymphatic endothelial cell-specific VEGF receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inagaki, Junko; Takahashi, Katsuyuki; Ogawa, Hiroko

2014-05-01

Angiogenesis and lymphangiogenesis play roles in malignant tumor progression, dissemination, and metastasis. ADAMTS1, a member of the matrix metalloproteinase family, is known to inhibit angiogenesis. Recombinant ADAMTS1 was shown to strongly inhibit angiogenesis. We investigated whether ADAMTS1 inhibited lymphangiogenesis in the present study. We examined cell proliferation and cell migration in normal human dermal lymphatic microvascular endothelial cells (HMVEC-dLy) transduced with or without adenoviral human ADAMTS1 gene therapy. We then examined the VEGFC/VEGFR3 signal transduction pathway in ADAMTS1-transduced HMVEC-dLy. Cell proliferation and tube formation in Matrigel were significantly lower with transduced ADAMTS1 than with control (non-transduced HMVEC-dLy). The phosphorylation ofmore » VEGFR3 was also attenuated by ADAMTS1 gene therapy in HMVEC-dLy. Immunoprecipitation assays revealed that ADAMTS1 formed a complex with VEGFC. Our results demonstrated that ADAMTS1 inhibited lymphangiogenesis in vitro. The data highlight the new function of ADAMTS1 in the regulation of lymphangiogenesis and the therapeutic potential of ADAMTS1 in cancer therapy. - Highlights: • ADAMTS1 significantly inhibited tube formation and cell proliferation in HMVEC-dLy. • Reduced lymph endothelial cell migration in ADAMTS1 transduced co-culture systems. • VEGFC-stimulated phosphorylation of VEGFR3 is attenuated by ADAMTS1. • Reduced phosphorylation of Akt and ERK1/2 in ADAMTS1 treated HMVEC-dLy. • ADAMTS1 binds directly to VEGFC.« less

Chemical dampening of Ly6C(hi) monocytes in the periphery produces anti-depressant effects in mice.

PubMed

Zheng, Xiao; Ma, Sijing; Kang, An; Wu, Mengqiu; Wang, Lin; Wang, Qiong; Wang, Guangji; Hao, Haiping

2016-01-19

The involvement of systemic immunity in depression pathogenesis promises a periphery-targeting paradigm in novel anti-depressant discovery. However, relatively little is known about druggable targets in the periphery for mental and behavioral control. Here we report that targeting Ly6C(hi) monocytes in blood can serve as a strategy for anti-depressant purpose. A natural compound, ginsenoside Rg1 (Rg1), was firstly validated as a periphery-restricted chemical probe. Rg1 selectively suppressed Ly6C(hi) monocytes recruitment to the inflamed mice brain. The proinflammatory potential of Ly6C(hi) monocytes to activate astrocytes was abrogated by Rg1, which led to a blunted feedback release of CCL2 to recruit the peripheral monocytes. In vitro study demonstrated that Rg1 pretreatment on activated THP-1 monocytes retarded their ability to trigger CCL2 secretion from co-cultured U251 MG astrocytes. CCL2-triggered p38/MAPK and PI3K/Akt activation were involved in the action of Rg1. Importantly, in mice models, we found that dampening Ly6C(hi) monocytes at the periphery ameliorated depression-like behavior induced by neuroinflammation or chronic social defeat stress. Together, our work unravels that blood Ly6C(hi) monocytes may serve as the target to enable remote intervention on the depressed brain, and identifies Rg1 as a lead compound for designing drugs targeting peripheral CCL2 signals.

Energy balance in the solar transition region. II - Effects of pressure and energy input on hydrostatic models

NASA Technical Reports Server (NTRS)

Fontenla, J. M.; Avrett, E. H.; Loeser, R.

1991-01-01

The radiation of energy by hydrogen lines and continua in hydrostatic energy-balance models of the transition region between the solar chromosphere and corona is studied using models which assume that mechanical or magnetic energy is dissipated in the hot corona and is then transported toward the chromosphere down the steep temperature gradient of the transition region. These models explain the average quiet sun and also the entire range of variability of the Ly-alpha lines. The relations between the downward energy flux, the pressure of the transition region, and the different hydrogen emission are described.

The hot subdwarf in the eclipsing binary HD 185510

NASA Technical Reports Server (NTRS)

Jeffery, C. S.; Simon, Theodore; Evans, T. L.

1992-01-01

High-resolution spectroscopic measurements of radial velocity are employed to characterize the eclipsing binary HD 185510 in terms of masses and evolutionary status. The IUE is used to obtain the radial velocities which indicate a large mass ratio Mp/Ms of 7.45 +/- 0.15, and Teff is given at 25,000 +/- 1000 K based on Ly alpha and UV spectrophotometry. Photometric observations are used to give an orbital inclination of between 90 and 70 deg inclusive, leading to masses of 0.31-0.37 and 2.3-2.8 solar mass for the hot star and the K star, respectively. The surface gravity of HD 185510B is shown to be higher than those values for sdB stars suggesting that the object is a low-mass white dwarf that has not reached its fully degenerate configuration. The object is theorized to be a low-mass helium main-sequence star or a nascent helium degenerate in a post-Algol system.

The MUSE Hubble Ultra Deep Field Survey. VIII. Extended Lyman-α haloes around high-z star-forming galaxies

NASA Astrophysics Data System (ADS)

Leclercq, Floriane; Bacon, Roland; Wisotzki, Lutz; Mitchell, Peter; Garel, Thibault; Verhamme, Anne; Blaizot, Jérémy; Hashimoto, Takuya; Herenz, Edmund Christian; Conseil, Simon; Cantalupo, Sebastiano; Inami, Hanae; Contini, Thierry; Richard, Johan; Maseda, Michael; Schaye, Joop; Marino, Raffaella Anna; Akhlaghi, Mohammad; Brinchmann, Jarle; Carollo, Marcella

2017-11-01

We report the detection of extended Lyα haloes around 145 individual star-forming galaxies at redshifts 3 ≤ z ≤ 6 in the Hubble Ultra Deep Field observed with the Multi-Unit Spectroscopic Explorer (MUSE) at ESO-VLT. Our sample consists of continuum-faint (- 15 ≥ MUV ≥ -22) Lyα emitters (LAEs). Using a 2D, two-component (continuum-like and halo) decomposition of Lyα emission assuming circular exponential distributions, we measure scale lengths and luminosities of Lyα haloes. We find that 80% of our objects having reliable Lyα halo measurements show Lyα emission that is significantly more extended than the UV continuum detected by HST (by a factor ≈4 to >20). The median exponential scale length of the Lyα haloes in our sample is ≈4.5 kpc with a few haloes exceeding 10 kpc. By comparing the maximal detected extent of the Lyα emission with the predicted dark matter halo virial radii of simulated galaxies, we show that the detected Lyα emission of our selected sample of Lyα emitters probes a significant portion of the cold circum-galactic medium of these galaxies (>50% in average). This result therefore shows that there must be significant HI reservoirs in the circum-galactic medium and reinforces the idea that Lyα haloes are ubiquitous around high-redshift Lyα emitting galaxies. Our characterization of the Lyα haloes indicates that the majority of the Lyα flux comes from the halo (≈65%) and that their scale lengths seem to be linked to the UV properties of the galaxies (sizes and magnitudes). We do not observe a significant Lyα halo size evolution with redshift, although our sample for z> 5 is very small. We also explore the diversity of the Lyα line profiles in our sample and we find that the Lyα lines cover a large range of full width at half maximum (FWHM) from 118 to 512 km s-1. While the FWHM does not seem to be correlated to the Lyα scale length, most compact Lyα haloes and those that are not detected with high significance tend to have narrower Lyα profiles (<350 km s-1). Finally, we investigate the origin of the extended Lyα emission but we conclude that our data do not allow us to disentangle the possible processes, i.e. scattering from star-forming regions, fluorescence, cooling radiation from cold gas accretion, and emission from satellite galaxies. MUSE Ultra Deep Field Lyα haloes catalog (Table B.1) is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A8

Distinct mobilization of leukocytes and hematopoietic stem cells by CXCR4 peptide antagonist LY2510924 and monoclonal antibody LY2624587

PubMed Central

Peng, Sheng-Bin; Van Horn, Robert D.; Yin, Tinggui; Brown, Robin M.; Roell, William C.; Obungu, Victor H.; Ruegg, Charles; Wroblewski, Victor J.; Raddad, Eyas; Stille, John R.

2017-01-01

Stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 play a critical role in mobilization and redistribution of immune cells and hematopoietic stem cells (HSCs). We evaluated effects of two CXCR4-targeting agents, peptide antagonist LY2510924 and monoclonal antibody LY2624587, on mobilizing HSCs and white blood cells (WBCs) in humans, monkeys, and mice. Biochemical analysis showed LY2510924 peptide blocked SDF-1/CXCR4 binding in all three species; LY2624587 antibody blocked binding in human and monkey, with minimal activity in mouse. Cellular analysis showed LY2624587 antibody, but not LY2510924 peptide, down-regulated cell surface CXCR4 and induced hematological tumor cell death; both agents have been shown to inhibit SDF-1/CXCR4 interaction and downstream signaling. In animal models, LY2510924 peptide induced robust, prolonged, dose- and time-dependent WBC and HSC increases in mice and monkeys, whereas LY2624587 antibody induced only moderate, transient increases in monkeys. In clinical trials, similar pharmacodynamic effects were observed in patients with advanced cancer: LY2510924 peptide induced sustained WBC and HSC increases, while LY2624587 antibody induced only minimal, transient WBC changes. These distinct pharmacodynamic effects in two different classes of CXCR4 inhibitors are clinically important and should be carefully considered when designing combination studies with immune checkpoint inhibitors or other agents for cancer therapy. PMID:29212254

A Spectroscopic Search for AGN Activity in the Reionization Era

NASA Astrophysics Data System (ADS)

Laporte, Nicolas; Nakajima, Kimihiko; Ellis, Richard S.; Zitrin, Adi; Stark, Daniel P.; Mainali, Ramesh; Roberts-Borsani, G. W.

2017-12-01

The ubiquity of Lyman alpha (Lyα) emission in a sample of four bright [O III]-strong star-forming galaxies with redshifts above seven has led to the suggestion that such luminous sources represent a distinct population compared with their fainter, more numerous counterparts. The presence of Lyα emission within the reionization era could indicate that these sources created early ionized bubbles due to their unusually strong radiation, possibly because of the presence of active galactic nuclei. To test this hypothesis, we secured long integration spectra with XSHOOTER on the VLT for three z≃ 7 sources selected to have similar luminosities and prominent excess fluxes in the IRAC 3.6 or 4.5 μm band, usually attributed to strong [O III] emission. We secured additional spectroscopy for one of these galaxies at z = 7.15 using MOSFIRE at the Keck telescope. For the most well-studied source in our sample with the strongest IRAC excess, we detect significant nebular emission from He II and N V indicative of a non-thermal source. For the other two sources at z = 6.81 and z = 6.85, for which no previous optical/near-infrared spectroscopy was available, Lyα is seen in one and C III] emission in the other. Although based on a modest sample, our results further support the hypothesis that the phenomenon of intense [O III] emission is associated preferentially with sources lying in early ionized bubbles. However, even though one of our sources at z = 7.15 suggests the presence of non-thermal radiation, such ionized bubbles may not uniquely arise in this manner. We discuss the unique advantages of extending such challenging diagnostic studies with JWST.

Insulin-like growth factor-1 (IGF-1) promotes primordial follicle growth and reduces DNA fragmentation through the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signalling pathway.

PubMed

Bezerra, Maria É S; Barberino, Ricássio S; Menezes, Vanúzia G; Gouveia, Bruna B; Macedo, Taís J S; Santos, Jamile M S; Monte, Alane P O; Barros, Vanessa R P; Matos, Maria H T

2018-05-30

We investigated the effects of insulin-like growth factor 1 (IGF-1) on the morphology and follicular activation of ovine preantral follicles cultured in situ and whether the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway is involved in IGF-1 action in the sheep ovary. Ovine ovarian fragments were fixed for histological and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) analyses (fresh control) or cultured in supplemented alpha-minimum essential medium (α-MEM+; control) or α-MEM+ with IGF-1 (1, 10, 50, 100 or 200ngmL-1) for 7 days. Follicles were classified as normal or atretic, primordial or growing and the oocyte and follicle diameters were measured. DNA fragmentation was evaluated by TUNEL assay. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was performed on the fresh control, α-MEM+ and 100ngmL-1 IGF-1 samples. Inhibition of PI3K activity was performed through pretreatment with the PI3K inhibitor LY294002 and phosphorylated AKT (pAKT) expression was analysed after culture in the absence or presence of LY294002. IGF-1 at 100ngmL-1 increased (P<0.05) follicular activation compared with α-MEM+ and decreased TUNEL-positive cells (P<0.05) compared with other treatments. PCNA-positive cells also increased (P<0.05) in 100ngmL-1 IGF-1. LY294002 significantly inhibited follicular activation stimulated by α-MEM+ and 100ngmL-1 IGF-1 and reduced pAKT expression in follicles. Overall, IGF-1 at 100ngmL-1 promoted primordial follicle activation, cell proliferation and reduced DNA fragmentation after in situ culture through the PI3K/AKT pathway.

Novel PEGylated Basal Insulin LY2605541 Has a Preferential Hepatic Effect on Glucose Metabolism

PubMed Central

Moore, Mary Courtney; Smith, Marta S.; Sinha, Vikram P.; Beals, John M.; Michael, M. Dodson; Jacober, Scott J.; Cherrington, Alan D.

2014-01-01

The impact of the novel basal insulin LY2605541 (LY) on hepatic and nonhepatic glucose uptake (non-HGU) was evaluated. Conscious dogs underwent euglycemic clamps with tracer and hepatic balance measurements. Clamp period infusions were peripheral venous regular insulin (0.1 nmol ⋅ kg−1 ⋅ h−1 [control], n = 6) or LY (bolus [nmol/kg], continuous [nmol ⋅ kg−1 ⋅ h−1]: 0.5, 0.5 [n = 6]; 0.375, 0.375 [n = 5]; 0.25, 0.25 [n = 4]), somatostatin, and glucose, as well as intraportal glucagon (basal). During the clamp, the dogs switched from net hepatic glucose output to uptake (rates reached 2.1 ± 1.2, 0.9 ± 2.1, 8.6 ± 2.3, and 6.0 ± 1.1 µmol ⋅ kg−1 ⋅ min−1 within 5 h in control, LY0.25, LY0.375, and LY0.5, respectively). Non-HGU in LY increased less than in control; the ratio of change from basal in non-HGU to change in net hepatic glucose balance, calculated when glucose infusion rates (GIRs) were ~20 µmol ⋅ kg-1 ⋅ min−1 in all groups, was higher in control (1.17 ± 0.38) versus LY0.25 (0.39 ± 0.33), LY0.375 (−0.01 ± 0.13), and LY0.5 (−0.09 ± 0.07). Likewise, the change from baseline in glucose Rd-to-Ra ratio was greatest in control (1.4 ± 0.3 vs. 0.6 ± 0.4, 0.5 ± 0.2, and 0.6 ± 0.2 in LY0.25, LY0.375, and LY0.5, respectively). In contrast to exogenously administered human insulin, LY demonstrated preferential hepatic effects, similar to endogenously secreted insulin. Therefore, the analog might reduce complications associated with current insulin therapy. PMID:24089512

Chromospheric Activity in Population II Giants

NASA Technical Reports Server (NTRS)

Harper, Graham M.

2004-01-01

One of the mysteries of Population II giants is that they still show chromospheric emission despite their great age. The global dynamo which was active during their main-sequence lifetimes is expected to become extremely weak through magnetic rotational braking. The nature of the observed emission is not understood; although acoustic shock waves might provide the heating, acoustic waves are not predicted to drive the observed mass loss - which in turn requires the dissipation of magneto-hydrodynamic waves. This program was designed to search for the faint stellar H Ly beta emission wings and the fluorescent Fe II and H2 emission from one of the brightest, metal poor, Population II stars. These FUSE diagnostics, when combined with existing UV and optical spectra, help determine the major radiative cooling channels for the chromosphere. This observation was to complement that previously planned for the mildly metal deficient giant alpha Boo (K2 III). However, alpha Boo has yet to be observed with FUSE.

The MUSCLES Treasury Survey: Intrinsic Lyα Profile Reconstructions and UV, X-ray, and Optical Correlations of Low-mass Exoplanet Host Stars

NASA Astrophysics Data System (ADS)

Youngblood, Allison; France, Kevin; Loyd, R. O. Parke

2016-01-01

UV stellar radiation can significantly impact planetary atmospheres through heating and photochemistry, even regulating production of potential biomarkers. Cool stars emit the majority of their UV radiation in the form of emission lines, and the incident UV radiation on close-in habitable-zone planets is significant. Lyα (1215.67 Å) dominates the 912 - 3200 Å spectrum of cool stars, but strong absorption from the interstellar medium (ISM) makes direct observations of the intrinsic Lyα emission of even nearby stars challenging. The MUSCLES Hubble Space Telescope Treasury Survey (Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems) has completed observations of 7 M and 4 K stars hosting exoplanets (d < 22 pc) with simultaneous X-ray and ground-based optical spectroscopy for many of the targets. We have reconstructed the intrinsic Lyα profiles using an MCMC technique and used the results to estimate the extreme ultraviolet (100 - 911 Å) spectrum. We also present empirical relations between chromospheric UV and optical lines, e.g., Lyα, Mg II, Ca II H & K, and Hα, for use when direct UV observations of low-mass exoplanet host stars are not possible. The spectra presented here will be made publicly available through MAST to support exoplanet atmosphere modeling.

Simplex and duplex event-specific analytical methods for functional biotech maize.

PubMed

Lee, Seong-Hun; Kim, Su-Jeong; Yi, Bu-Young

2009-08-26

Analytical methods are very important in the control of genetically modified organism (GMO) labeling systems or living modified organism (LMO) management for biotech crops. Event-specific primers and probes were developed for qualitative and quantitative analysis for biotech maize event 3272 and LY 038 on the basis of the 3' flanking regions, respectively. The qualitative primers confirmed the specificity by a single PCR product and sensitivity to 0.05% as a limit of detection (LOD). Simplex and duplex quantitative methods were also developed using TaqMan real-time PCR. One synthetic plasmid was constructed from two taxon-specific DNA sequences of maize and two event-specific 3' flanking DNA sequences of event 3272 and LY 038 as reference molecules. In-house validation of the quantitative methods was performed using six levels of mixing samples, from 0.1 to 10.0%. As a result, the biases from the true value and the relative deviations were all within the range of +/-30%. Limits of quantitation (LOQs) of the quantitative methods were all 0.1% for simplex real-time PCRs of event 3272 and LY 038 and 0.5% for duplex real-time PCR of LY 038. This study reports that event-specific analytical methods were applicable for qualitative and quantitative analysis for biotech maize event 3272 and LY 038.

The CALYMHA survey: Lyα luminosity function and global escape fraction of Lyα photons at z = 2.23

NASA Astrophysics Data System (ADS)

Sobral, David; Matthee, Jorryt; Best, Philip; Stroe, Andra; Röttgering, Huub; Oteo, Iván; Smail, Ian; Morabito, Leah; Paulino-Afonso, Ana

2017-04-01

We present the CAlibrating LYMan-α with Hα (CALYMHA) pilot survey and new results on Lyman α (Lyα) selected galaxies at z ˜ 2. We use a custom-built Lyα narrow-band filter at the Isaac Newton Telescope, designed to provide a matched volume coverage to the z = 2.23 Hα HiZELS survey. Here, we present the first results for the COSMOS and UDS fields. Our survey currently reaches a 3σ line flux limit of ˜4 × 10-17 erg s-1 cm-2, and a Lyα luminosity limit of ˜1042.3 erg s-1. We find 188 Lyα emitters over 7.3 × 105 Mpc3, but also find significant numbers of other line-emitting sources corresponding to He II, C III] and C IV emission lines. These sources are important contaminants, and we carefully remove them, unlike most previous studies. We find that the Lyα luminosity function at z = 2.23 is very well described by a Schechter function up to LLy α ≈ 1043 erg s-1 with L^{ast }=10^{42.59^{+0.16}_{-0.08}} erg s-1, φ ^{ast }=10^{-3.09^{+0.14}_{-0.34}} Mpc-3 and α = -1.75 ± 0.25. Above LLy α ≈ 1043 erg s-1, the Lyα luminosity function becomes power-law like, driven by X-ray AGN. We find that Lyα-selected emitters have a high escape fraction of 37 ± 7 per cent, anticorrelated with Lyα luminosity and correlated with Lyα equivalent width. Lyα emitters have ubiquitous large (≈40 kpc) Lyα haloes, ˜2 times larger than their Hα extents. By directly comparing our Lyα and Hα luminosity functions, we find that the global/overall escape fraction of Lyα photons (within a 13 kpc radius) from the full population of star-forming galaxies is 5.1 ± 0.2 per cent at the peak of the star formation history. An extra 3.3 ± 0.3 per cent of Lyα photons likely still escape, but at larger radii.

HELIOSPHERIC STRUCTURE: THE BOW WAVE AND THE HYDROGEN WALL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zank, G. P.; Heerikhuisen, J.; Pogorelov, N. V.

2013-01-20

Recent IBEX observations indicate that the local interstellar medium (LISM) flow speed is less than previously thought (23.2 km s{sup -1} rather than 26 km s{sup -1}). Reasonable LISM plasma parameters indicate that the LISM flow may be either marginally super-fast magnetosonic or sub-fast magnetosonic. This raises two challenging questions: (1) Can a LISM model that is barely super-fast or sub-fast magnetosonic account for Ly{alpha} observations that rely critically on the additional absorption provided by the hydrogen wall (H-wall)? and (2) If the LISM flow is weakly super-fast magnetosonic, does the transition assume the form of a traditional shock ormore » does neutral hydrogen (H) mediate shock dissipation and hence structure through charge exchange? Both questions are addressed using three three-dimensional self-consistently coupled magnetohydrodynamic plasma-kinetic H models with different LISM magnetic field strengths (2, 3, and 4 {mu}G) as well as plasma and neutral H number densities. The 2 and 3 {mu}G models are fast magnetosonic far upwind of the heliopause whereas the 4 {mu}G model is fully subsonic. The 2 {mu}G model admits a broad ({approx}50-75 AU) bow-shock-like structure. The 3 {mu}G model has a smooth super-fast-sub-fast magnetosonic transition that resembles a very broad, {approx}200 AU thick, bow wave. A theoretical analysis shows that the transition from a super-fast to a sub-fast magnetosonic downstream state is due to the charge exchange of fast neutral H and hot neutral H created in the supersonic solar wind and hot inner heliosheath, respectively. For both the 2 {mu}G and the 3 {mu}G models, the super-fast magnetosonic LISM flow passes through a critical point located where the fast magnetosonic Mach number M = 1 and Q{sub e} = {gamma}/({gamma} - 1)UQ{sub m} , where Q{sub e} and Q{sub m} are the plasma energy and momentum source terms due to charge exchange, U is the LISM flow speed, and {gamma} is the plasma adiabatic index. Because the Mach number is only barely super-fast magnetosonic in the 3 {mu}G case, the hot and fast neutral H can completely mediate the transition and impose a charge exchange length scale on the structure, making the solar-wind-LISM interaction effectively bow-shock-free. The charge exchange of fast and hot heliospheric neutral H therefore provides a primary dissipation mechanism at the weak heliospheric bow shock, in some cases effectively creating a one-shock heliosphere (i.e., a heliospheric termination shock only). Both super-fast magnetosonic models produce a sizeable H-wall. We find that (1) a sub-fast magnetosonic LISM flow cannot model the observed Ly{alpha} absorption profiles along the four sightlines considered ({alpha} Cen, 36 Oph, DK UMa, and {chi}{sup 1} Ori-upwind, sidewind, and downwind respectively); (2) both the super-fast magnetosonic models can account for the Ly{alpha} observations, with possibly the bow-shock-free 3 {mu}G model being slightly favored. Subject to further modeling and comparison against further lines of sight, we conclude with the tantalizing possibility that IBEX may have discovered a class of interstellar shocks mediated by neutral H.« less

The O-type eclipsing contact binary LY Aurigae - member of a quadruple system

NASA Astrophysics Data System (ADS)

Mayer, Pavel; Drechsel, Horst; Harmanec, Petr; Yang, Stephenson; Šlechta, Miroslav

2013-11-01

The eclipsing binary LY Aur (O9 II + O9 III) belongs to the rare class of early-type contact systems. We obtained 23 new spectra at the Ondřejov and Dominion Astrophysical Observatories, which were analysed with four older Calar Alto and one ELODIE archive spectra. A new result of this study is that the visual companion of LY Aur - the spectral lines of which are clearly seen in our spectra - is also an SB1 binary having an orbital period of 20.46d, an eccentric orbit, and a radial velocity semi-amplitude of 33 km s-1. The Hα line blend contains an emission component, which shows dependence on the orbital phase of the eclipsing system, with the strongest emission around the secondary eclipse. Revised elements of the eclipsing binary and the orbital solution of the companion binary are determined from our set of spectra and new light-curve solutions of the eclipsing pair. The mass of the primary of 25.5 M⊙ agrees well with its spectral type, whereas the secondary mass of 14 M⊙ is smaller than expected. From an O-C analysis of the minimum times of LY Aur that span more than 40 years, we found that the orbital period is decreasing, indicating the presence of interaction processes. The system is likely in a phase of non-conservative mass exchange. Based on spectral observations collected at the German-Spanish Observatory, Calar Alto, Spain; Dominion Astrophysical Observatory, Canada; Ondřejov Observatory, Czech Republic, and an archival Haute Provence Observatory ELODIE spectrum.

Ly49H signaling through DAP10 is essential for optimal natural killer cell responses to mouse cytomegalovirus infection

PubMed Central

Orr, Mark T.; Sun, Joseph C.; Hesslein, David G.T.; Arase, Hisashi; Phillips, Joseph H.; Takai, Toshiyuki

2009-01-01

The activating natural killer (NK) cell receptor Ly49H recognizes the mouse cytomegalovirus (MCMV) m157 glycoprotein expressed on the surface of infected cells and is required for protection against MCMV. Although Ly49H has previously been shown to signal via DAP12, we now show that Ly49H must also associate with and signal via DAP10 for optimal function. In the absence of DAP12, DAP10 enables Ly49H-mediated killing of m157-bearing target cells, proliferation in response to MCMV infection, and partial protection against MCMV. DAP10-deficient Ly49H+ NK cells, expressing only Ly49H–DAP12 receptor complexes, are partially impaired in their ability to proliferate during MCMV infection, display diminished ERK1/2 activation, produce less IFN-γ upon Ly49H engagement, and demonstrate reduced control of MCMV infection. Deletion of both DAP10 and DAP12 completely abrogates Ly49H surface expression and control of MCMV infection. Thus, optimal NK cell–mediated immunity to MCMV depends on Ly49H signaling through both DAP10 and DAP12. PMID:19332875

The largest Lyapunov exponent of gait in young and elderly individuals: A systematic review.

PubMed

Mehdizadeh, Sina

2018-02-01

The largest Lyapunov exponent (LyE) is an accepted method to quantify gait stability in young and old adults. However, a range of LyE values has been reported in the literature for healthy young and elderly adults in normal walking. Therefore, it has been impractical to use the LyE as a clinical measure of gait stability. The aims of this systematic review were to summarize different methodological approaches of quantifying LyE, as well as to classify LyE values of different body segments and joints in young and elderly individuals during normal walking. The Pubmed, Ovid Medline, Scopus and ISI Web of Knowledge databases were searched using keywords related to gait, stability, variability, and LyE. Only English language articles using the Lyapunov exponent to quantify the stability of healthy normal young and old subjects walking on a level surface were considered. 102 papers were included for full-text review and data extraction. Data associated with the walking surface, data recording method, sampling rate, walking speed, body segments and joints, number of strides/steps, variable type, filtering, time-normalizing, state space dimension, time delay, LyE algorithm, and the LyE values were extracted. The disparity in implementation and calculation of the LyE was from, (i) experiment design, (ii) data pre-processing, and (iii) LyE calculation method. For practical implementation of LyE as a measure of gait stability in clinical settings, a standard and universally accepted approach of calculating LyE is required. Therefore, future studies should look for a standard and generalized procedure to apply and calculate LyE. Copyright © 2017 Elsevier B.V. All rights reserved.

Lymphocytic Esophagitis: An emerging clinicopathologic disease associated with dysphagia

PubMed Central

Pasricha, Sarina; Gupta, Amit; Reed, Craig C.; Speck, Olga; Woosley, John T.; Dellon, Evan S.

2016-01-01

Background Lymphocytic Esophagitis (LyE) is a recently described clinicopathological condition, but little is known about its features and clinical associations. Aim To characterize patients with LyE, compare them to non-LyE controls, and identify risk factors. Methods We conducted a retrospective study of all patients ≥18 years old who underwent upper endoscopy with esophageal biopsy between January 1, 2000 and June 1, 2012. Archived pathology slides were re-reviewed and LyE was diagnosed if there was lymphocyte-predominant esophageal inflammation with no eosinophils or granulocytes. Three non-LyE controls groups were also defined: reflux, eosinophilic esophagitis (EoE), and normal. Clinical data were extracted from electronic medical records, and LyE cases were compared to non-LyE controls. Results 27 adults were diagnosed with LyE, and the majority were female (63%). The most common symptom was dysphagia (70%). 52% had a prior or current diagnosis of reflux. Endoscopic findings included strictures (37%), erosive esophagitis (33%), rings (26%), and hiatal hernia (26%); 33% of patients required dilation. After histology re-review, 78% of LyE patients were found to have more than 20 lymphs/hpf. In comparison to the normal, reflux and EoE controls, patients with LyE tended to be non-white (p<0.01), were more commonly tobacco users (p=0.02), and less likely to have seasonal allergies (p=0.02). Conclusion LyE commonly presents with dysphagia due to esophageal strictures which require dilation. Smoking was associated with LyE whereas atopy was not. LyE should be considered as a diagnostic possibility in patients with these characteristics undergoing upper endoscopy. PMID:27343035

Lymphocytic Esophagitis: An Emerging Clinicopathologic Disease Associated with Dysphagia.

PubMed

Pasricha, Sarina; Gupta, Amit; Reed, Craig C; Speck, Olga; Woosley, John T; Dellon, Evan S

2016-10-01

Lymphocytic esophagitis (LyE) is a recently described clinicopathological condition, but little is known about its features and clinical associations. The aim of this study was to characterize patients with LyE, compare them to non-LyE controls, and identify risk factors. We conducted a retrospective study of all patients ≥18 years old who underwent upper endoscopy with esophageal biopsy between January 1, 2000, and June 1, 2012. Archived pathology slides were re-reviewed, and LyE was diagnosed if there was lymphocyte-predominant esophageal inflammation with no eosinophils or granulocytes. Three non-LyE controls groups were also defined: reflux, eosinophilic esophagitis (EoE), and normal. Clinical data were extracted from electronic medical records, and LyE cases were compared to non-LyE controls. Twenty-seven adults were diagnosed with LyE, and the majority were female (63 %). The most common symptom was dysphagia (70 %). Fifty-two percentage had a prior or current diagnosis of reflux. Endoscopic findings included strictures (37 %), erosive esophagitis (33 %), rings (26 %), and hiatal hernia (26 %); 33 % of patients required dilation. After histology re-review, 78 % of LyE patients were found to have more than 20 lymphs/hpf. In comparison with the normal, reflux and EoE controls, patients with LyE tended to be nonwhite (p < 0.01), were more commonly tobacco users (p = 0.02) and less likely to have seasonal allergies (p = 0.02). LyE commonly presents with dysphagia due to esophageal strictures which require dilation. Smoking was associated with LyE, whereas atopy was not. LyE should be considered as a diagnostic possibility in patients with these characteristics undergoing upper endoscopy.

Inflammatory Ly6Chigh Monocytes Protect against Candidiasis through IL-15-Driven NK Cell/Neutrophil Activation.

PubMed

Domínguez-Andrés, Jorge; Feo-Lucas, Lidia; Minguito de la Escalera, María; González, Leticia; López-Bravo, María; Ardavín, Carlos

2017-06-20

Neutrophils play a crucial role in defense against systemic candidiasis, a disease associated with a high mortality rate in patients receiving immunosuppressive therapy, although the early immune mechanisms that boost the candidacidal activity of neutrophils remain to be defined in depth. Here, we used a murine model of systemic candidiasis to explore the role of inflammatory Ly6C high monocytes in NK cell-mediated neutrophil activation during the innate immune response against C. albicans. We found that efficient anti-Candida immunity required a collaborative response between the spleen and kidney, which relied on type I interferon-dependent IL-15 production by spleen inflammatory Ly6C high monocytes to drive efficient activation and GM-CSF release by spleen NK cells; this in turn was necessary to boost the Candida killing potential of kidney neutrophils. Our findings unveil a role for IL-15 as a critical mediator in defense against systemic candidiasis and hold promise for the design of IL-15-based antifungal immunotherapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Antidepressant-like effects of scopolamine in mice are enhanced by the group II mGlu receptor antagonist LY341495.

PubMed

Podkowa, Karolina; Podkowa, Adrian; Sałat, Kinga; Lenda, Tomasz; Pilc, Andrzej; Pałucha-Poniewiera, Agnieszka

2016-12-01

Clinical studies have shown that the muscarinic receptor antagonist scopolamine induces a potent and rapid antidepressant effect relative to conventional antidepressants. However, potential undesirable effects, including memory impairment, partially limit the use of scopolamine in psychiatry. In the present study, we propose to overcome these limitations and enhance the therapeutic effects of scopolamine via administration in combination with the group II metabotropic glutamate (mGlu) receptor antagonist, LY341495. Joint administration of sub-effective doses of scopolamine (0.03 or 0.1 mg/kg, i.p.) with a sub-effective dose of LY341495 (0.1 mg/kg, i.p.) induced a profound antidepressant effect in the tail suspension test (TST) and in the forced swim test (FST) in mice. This drug combination did not impair memory, as measured using the Morris water maze (MWM), and did not influence the locomotor activity of mice. Furthermore, we found that an AMPA receptor antagonist, NBQX (10 mg/kg), completely reversed the antidepressant-like activity of a mixture of scopolamine and LY341495 in the TST. However, this effect was not influenced by para-chlorophenylalanine (PCPA) pre-treatment, indicating a lack of involvement of serotonergic system activation in the antidepressant-like effects of jointly given scopolamine and LY341495. Therefore, the combined administration of low doses of the antimuscarinic drug scopolamine and the group II mGlu receptor antagonist LY341495 might be a new, effective and safe strategy in the therapy of depression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combinatorial therapy with adenoviral-mediated PTEN and a PI3K inhibitor suppresses malignant glioma cell growth in vitro and in vivo by regulating the PI3K/AKT signaling pathway.

PubMed

Nan, Yang; Guo, Liyun; Song, Yunpeng; Wang, Le; Yu, Kai; Huang, Qiang; Zhong, Yue

2017-08-01

Glioblastoma is a highly invasive and challenging tumor of the central nervous system. The mutation/deletion of the tumor suppressor phosphatase and tensin homolog (PTEN) gene is the main genetic change identified in glioblastomas. PTEN plays a critical role in tumorigenesis and has been shown to be an important therapeutic target. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 is commonly used to inhibit glioma cell growth via regulation of the PI3K/AKT signaling pathway. In this study, we examined the growth inhibitory effects of a combinatorial therapy of adenoviral-mediated PTEN (Ad-PTEN) and LY294002 on LN229 and U251 glioma cells in vitro and on tumor xenografts in vivo. In vitro, LN229 and U251 glioma cells were treated by combinatorial therapy with Ad-PTEN and LY294002. The growth ability was determined by MTT assay. The cell cycle distribution was analyzed by flow cytometry. Cell invasive ability was analyzed by transwell invasion assay and cell apoptosis analysis via FITC-Annexin V analysis. In vivo, U251 subcutaneous glioblastoma xenograft was used to assay anti-tumor effect of combinatorial therapy with Ad-PTEN and LY294002 by mean volume of tumors, immunohistochemistry and TUNEL method. The combinatorial treatment clearly suppressed cell proliferation, arrested the cell cycle, reduced cell invasion and promoted cell apoptosis compared with the Ad-PTEN or LY294002 treatment alone. The treatment worked by inhibiting the PI3K/AKT pathway. In addition, the growth of U251 glioma xenografts treated with the combination of Ad-PTEN and LY294002 was significantly inhibited compared with those treated with Ad-PTEN or LY294002 alone. Our data indicated that the combination of Ad-PTEN and LY294002 effectively suppressed the malignant growth of human glioma cells in vitro and in tumor xenografts, suggesting a promising new approach for glioma gene therapy that warrants further investigation.

Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yèche, Christophe; Palanque-Delabrouille, Nathalie; Baur, Julien

We present constraints on masses of active and sterile neutrinos in the context of the ΛCDMν and ΛWDM models, respectively. We use the one-dimensional Lyα-forest power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III) measured by Palanque-Delabrouille et al. [1], and from the VLT/XSHOOTER legacy survey (XQ-100). In this paper, we present our own measurement of the publicly released XQ-100 quasar spectra, focusing in particular on an improved determination of the spectrograph resolution that allows us to push to smaller scales than the public release and reach k -modes of 0.070 s km{supmore » −1}. We compare the obtained 1D Lyα flux power spectrum to the one measured by Irsic et al. [2] to k -modes of 0.057 s km{sup −1}. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from Planck 2015 Cosmic Microwave Background (CMB) data. Combining BOSS and XQ-100 Lyα power spectra, we constrain the sum of neutrino masses to ∑ m {sub ν} < 0.8 eV (95% C.L.) including all identified sources of systematic uncertainties. With the addition of CMB data, this bound is tightened to ∑ m {sub ν} < 0.14 eV (95% C.L.). With their sensitivity to small scales, Lyα data are ideal to constrain ΛWDM models. Using XQ-100 alone, we issue lower bounds on pure dark matter particles: m {sub X} ∼> 2.08 : keV (95% C.L.) for early decoupled thermal relics, and m {sub s} ∼> 10.2 : keV (95% C.L.) for non-resonantly produced right-handed neutrinos. Combining the 1D Lyα-forest power spectrum measured by BOSS and XQ-100, we improve the two bounds to m {sub X} ∼> 4.17 : keV and m {sub s} ∼> 25.0 : keV (95% C.L.), slightly more constraining than what was achieved in Baur et al. 2015 [3] with BOSS data alone. The 3 σ bound shows a more significant improvement, increasing from m {sub X} ∼> 2.74 : keV for BOSS alone to m {sub X} ∼> 3.10 : keV for the combined BOSS+XQ-100 data set. Finally, we include in our analysis the first two redshift bins ( z = 4.2 and z = 4.6) of the power spectrum measured by Viel et al. 2013 [4] with the high-resolution HIRES/MIKE spectrographs. The addition of HIRES/MIKE power spectrum allows us to further improve the two limits to m {sub X} ∼> 4.65 : keV and m {sub s} ∼> 28.8 : keV (95% C.L.).« less

Radiation-damped profiles of extremely high column density neutral hydrogen: implications of cosmic reionization

NASA Astrophysics Data System (ADS)

Bach, Kiehunn

2017-01-01

Incorporating the time-dependent second-order perturbation theory for the Lyman scattering cross-section, we investigate the intergalactic absorption profiles of extremely high column density systems near the end of cosmic reionization. Assuming a representative set of the redshift distribution of neutral hydrogen, we quantitatively examined the impact of inhomogeneous density on the intrinsic absorption profiles. The cumulative absorption by neutral patches in the line of sight mainly affects the far off-centre region of the red damping wing, but the effect is not significant. The shape of the line centre can be modified by the near-zone distribution due to high opacities of the near-resonance scattering. On the other hand, the HWHM (half width at half-maximum) as an effective line width is relatively less sensitive to the local inhomogeneity. Specifically, when the two local damping wings of Lyα and Lyβ are close in spectra of the strongly damped systems, accurate profiles of both lines are required. In the case of N_{H I}≲ 10^{21} { cm^{-2}}, the two-level approximation is marginally applicable for the damping wing fit within 5 - 7 per cent errors. However, as the local column density reaches N_{H I}˜ 10^{22.3} { cm^{-2}}, this classical approximation yields a relative error of a 10 per cent overestimation in the red wing and a 20 per cent underestimation in the blue wing of Lyα. If severe extinction by the Lyα forests is carefully subtracted, the intrinsic absorption profile will provide a better constraint on the local ionized states. For practical applications, an analytic fitting function for the Lyβ scattering is derived.

Modulation of Hippocampal Synaptic Transmission by the Kynurenine Pathway Member Xanthurenic Acid and Other VGLUT Inhibitors

PubMed Central

Neale, S A; Copeland, C S; Uebele, V N; Thomson, F J; Salt, T E

2013-01-01

Xanthurenic acid (XA), an endogenous kynurenine, is a known vesicular glutamate transport (VGLUT) inhibitor and has also been proposed as an mGlu2/3 receptor agonist. Changes in these systems have been implicated in the pathophysiology of schizophrenia and other psychiatric disorders; however, little is known of how XA affects synaptic transmission. We therefore investigated the effects of XA on synaptic transmission at two hippocampal glutamatergic pathways and evaluated the ability of XA to bind to mGlu2/3 receptors. Field excitatory postsynaptic potentials (fEPSPs) were recorded from either the dentate gyrus (DG) or CA1 region of mouse hippocampal slices in vitro. Addition of XA to the bathing medium (1–10 mM) resulted in a dose-related reduction of fEPSP amplitudes (up to 52% reduction) in both hippocampal regions. In the DG, the VGLUT inhibitors Congo Red and Rose Bengal, and the mGlu2/3 agonist LY354740, also reduced fEPSPs (up to 80% reduction). The mGlu2/3 antagonist LY341495 reversed the LY354740 effect, but not the XA effect. LY354740, but not XA, also reduced DG paired-pulse depression. XA had no effect on specific binding of 1 nM [3H]LY341495 to membranes with human mGlu2 receptors. We conclude that XA can modulate synaptic transmission via a mechanism that may involve VGLUT inhibition rather than activation of mGlu2/3 receptors. This could be important in the pathophysiology of nervous system disorders including schizophrenia and might represent a target for developing novel pharmacological therapies. PMID:23303071

Antimutagenic action of the live yeast can be transmitted to the offspring of Drosophila melanogaster. A genetic study using the wing spot assay.

PubMed

Pimentel, Emilio; Cruces, Martha P

2018-01-01

The present study evaluates whether the protective effect of live yeast (LY) against direct and indirect mutagenic agents, persists in the offspring from individuals fed with LY. The wing-spot test in Drosophila was used; four different mates were performed: a) neither females nor males were fed with LY-enriched food (NLYxNLY); b) only females were fed (LYxNLY); c) males were fed (NLYxLY) or d) both progenitors were fed (LYxLY). Results confirm that LY strongly stimulates fecundity in females but not in males and provides strength to the egg for survive. A greater reduction in mutation rate was observed when females were feed, in the following relationship: LYxNLY>LYxLY>NLYxLY. No protection was found against action in any of the promutagens tested. Results suggest that LY has a very powerful antimutagenic action, predominantly against the action of ionizing radiation and Chromium trioxide that can be transmitted mainly through the female. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential antimutagenicity of WR-1065 added after irradiation in L5178Y cell lines

NASA Technical Reports Server (NTRS)

Evans, H. H.; Horng, M. F.; Ricanati, M.; McCoy, E. C.

1999-01-01

The purpose of this study was to determine the antimutagenicity of WR-1065 added after irradiation of cells of cell lines differing in their ability to rejoin radiation-induced DNA double-strand breaks (DSBs). The postirradiation antimutagenicity of WR-1065 at the thymidine kinase locus was demonstrated for L5178Y (LY)-S1 cells that are deficient in repair of DNA DSBs. Less postirradiation antimutagenicity of WR-1065 was observed in LY-R16 and LY-SR1 cells, which are relatively efficient in DSB repair. Postirradiation treatment with WR-1065 had only a small stimulatory effect on DSB rejoining. A 3-h incubation of irradiated LY cells with WR-1065 caused slight changes in the distribution of cells in the phases of the cell cycle that differed between LY-S1 and LY-SR1 cells. Both LY-S1 and LY-SR1 cells were protected against the cytotoxic and mutagenic effects of radiation when WR-1065 was present 30 min before and during the irradiation. We conclude that the differential postirradiation effects of WR-1065 in the LY-S1 and LY-SR1 cells are not caused by differences in cellular uptake of the radioprotector or in its radical scavenging activity. Possible mechanisms for the postirradiation antimutagenicity of WR-1065 are discussed.

The Ionization and Metallicity of the Intervening O VI Absorber at z=0.1212 in the Spectrum of H1821+643

NASA Technical Reports Server (NTRS)

Tripp, Todd M.; Giroux, Mark L.; Stocke, John T.; Tumlinson, Jason; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)

2001-01-01

We use high-resolution UV (ultraviolet) spectra of the radio-quiet QSO (quasi-stellar object) H1821+643 (z(sub em) = 0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) and the Far Ultraviolet Spectroscopic Explorer (FUSE), to study the ionization and metallicity of an intervening O VI absorption line system at z(sub abs) = 0.1212. This absorber has the following notable properties: (1) Several galaxies are close to the sight line at the absorber redshift, including an actively star-forming galaxy at a projected distance of 144 h(sub 75)(exp -1) kpc. (2) There is a complex cluster of H I Ly(alpha) absorption lines near the O VI redshift, including at least five components spread over a velocity range of approximately 700 km s(exp -1). (3) The strongest Ly(alpha) line in the cluster appears to be composed of a mildly saturated component with a typical b-value blended with a remarkably broad component with b approximately equals 85 km s(exp -1). (4) The O VI absorption is not aligned with the strongest (saturated) H I absorption, but instead is well-aligned with the very broad component. (5) The only detected species (at the 4(sigma) level) are O VI and H I despite coverage of strong transitions of abundant elements (e.g., C II, C III, and C IV). Based on these constraints, we find that the absorption line properties can be produced in collisionally ionized gas with 10(exp 5.3) is equal to or less than T is equal to or less than 10(exp 5.6) K and -1.8 is equal to or less than [O/H] is equal to or less than -0.6. However, we find that photoionization is also viable if the pathlength l through the absorbing gas is long enough; simple photoionization models require 85 is equal to or less than l is equal to or less than 1900 kpc and -1.1 is equal to or less than [O/H] is equal to or less than -0.3. We briefly discuss how observations of X-ray absorption lines due to O VII and O VIII could be used, in principle, to break the ionization mechanism degeneracy, and we conclude with some comments regarding the nature of O VI absorbers.

A Population of Faint Extended Line Emitters and the Host Galaxies of Optically Thick QSO Absorption Systems

NASA Astrophysics Data System (ADS)

Rauch, Michael; Haehnelt, Martin; Bunker, Andrew; Becker, George; Marleau, Francine; Graham, James; Cristiani, Stefano; Jarvis, Matt; Lacey, Cedric; Morris, Simon; Peroux, Celine; Röttgering, Huub; Theuns, Tom

2008-07-01

We have conducted a long-slit search for low surface brightness Lyα emitters at redshift 2.67 < z < 3.75. A 92 hr long exposure with the ESO VLT FORS2 instrument down to a 1 σ surface brightness detection limit of 8 × 10-20 erg cm-2 s-1 arcsec-2 per arcsec2 aperture yielded a sample of 27 single line emitters with fluxes of a few × 10-18 erg s-1 cm-2. We present arguments that most objects are indeed Lyα. The large comoving number density, 3 × 10-2 h370 Mpc-3, the large covering factor, dN/dz ~ 0.2-1, and the often extended Lyα emission suggest that the emitters can be identified with the elusive host population of damped Lyα systems (DLAS) and high column density Lyman limit systems (LLS). A small inferred star formation rate, perhaps supplemented by cooling radiation, appears to energetically dominate the Lyα emission, and is consistent with the low metallicity, low dust content, and theoretically inferred low masses of DLAS, and with the relative lack of success of earlier searches for their optical counterparts. Some of the line profiles show evidence for radiative transfer in galactic outflows. Stacking surface brightness profiles, we find emission out to at least 4''. The centrally concentrated emission of most objects appears to light up the outskirts of the emitters (where LLS arise) down to a column density where the conversion from UV to Lyα photon becomes inefficient. DLAS, high column density LLS, and the emitter population discovered in this survey appear to be different observational manifestations of the same low-mass, protogalactic building blocks of present-day L* galaxies. Based partly on observations made with ESO Telescopes at the Paranal Observatories under Program ID LP173.A-0440, and partly on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil) and CONICET (Argentina).

Escape of Resonantly Scattered Lyβ and Hα from Hot and Optically Thick Media

NASA Astrophysics Data System (ADS)

Chang, Seok-Jun; Lee, Hee-Won; Ahn, Sang-Hyeon; Lee, Hogyu; Angeloni, Rodolfo; Palma, Tali; Di Mille, Francesco

2018-02-01

We investigate the escape of Lyβ from emission nebulae with a significant population of excited hydrogen atoms in the level n=2, rendering them optically thick in Hα. The transfer of Lyβ line photons in these optically thick regions is complicated by the presence of another scattering channel leading to re-emission of Hα, alternating their identities between Lyβ and Hα. In this work, we develop a Monte Carlo code to simulate the transfer of Lyβ line photons incorporating the scattering channel into Hα. Both Hα and Lyβ lines are formed through diffusion in frequency space, where a line photon enters the wing regime after a fairly large number of resonance scatterings with hydrogen atoms. Various line profiles of Hα and Lyβ emergent from our model nebulae are presented. It is argued that the electron temperature is a critical parameter which controls the flux ratio of emergent Lyβ and Hα. Specifically for T=3 × 10^4{K} and Hα line center optical depth τ_α=10, the number flux ratio of emergent Lyβ and Hα is ˜ 49 percent, which is quite significant. We propose that the leaking Lyβ can be an interesting source for the formation of Hα wings observed in many symbiotic stars and active galactic nuclei. Similar broad Hα wings are also expected in Lyα emitting halos found in the early universe, which can be potentially probed by the James Webb Telescope in the future.

An Intercomparison Study of Two Proximate Damped Lyα Systems with Residual Flux upon the Lyα Absorption Trough toward Quasars

NASA Astrophysics Data System (ADS)

Xie, Xiaoyi; Zhou, Hongyan; Pan, Xiang; Jiang, Peng; Shi, Xiheng; Ji, Tuo; Zhang, Shaohua; Wu, Shengmiao; Zhong, Zhihao

2018-05-01

In this paper, we present an intercomparison study of two quasars, SDSS J145618.32+340037.2 and SDSS J215331.50–025514.1, which have proximate damped Lyα systems (PDLAs) with residual flux upon the Lyα absorption trough. Though they both have residual flux as luminous as 1043 erg s‑1, their PDLAs are quite different in, e.g., neutral hydrogen column density, metal line absorption strength, high-ionization absorption lines as well as residual flux strength. For J1456+3400, the H I column density is log(N H I /cm–2) = 20.6 ± 0.2, with z abs = 2.3138, nearly identical to the quasar redshift (z = 2.3142) determined from the [O III] emission line. The metallicity of this system is typical of DLAs and there is high ionization therein, suggesting that the PDLA system is multiphase, putting it in the quasar environment. For J2153–0255, we measure the H I column density to be log(N H I /cm–2) = 21.5 ± 0.1 at z abs = 3.511, slightly redshifted with respect to the quasar (z = 3.490) measured from C III]. The metallicity of this system is quite low and there is a lack of significant high-ionization absorption lines therein, suggesting that the system is beyond the quasar host galaxy. The residual flux is wide (∼1000 km s‑1) in J1456, with a significance of ∼8σ, while also wide (∼1500 km s‑1) but with a smaller significance of ∼3σ in J2153. Among many explanations, we find that Lyα fuzz or resonant scattering can be used to explain the residual flux in the two sources while partial coverage cannot be excluded for J1456. By comparing these two cases, together with a similar case reported previously, we suggest that the strength of the residual flux is related to properties such as metallicity and high-ionization absorption lines of PDLAs. The residual flux recorded upon the PDLA absorption trough opens a window for us to see the physical conditions and processes of the quasar environment, and their profile and strength further remind us of their spatial scales.

Direct energy inputs to the middle atmosphere

NASA Technical Reports Server (NTRS)

Rosenberg, T. J.; Lanzerotti, L. J.

1979-01-01

As a working definition of the extent of the middle atmosphere (MA), the height range from 30 to 100 km was adopted. The neutral and ionic composition and the dynamics within this height range are, for the most part, poorly understood. From available information, the importance of various particle and photon energy sources, including their variability, for ionization of the neutral atmosphere in this height range is assessed. The following topics are discussed: (1) penetration of the MA by particle and electromagnetic energy; (2) ionization sources for the MA; (3) galactic cosmic rays; (4) solar H Ly alpha, other EUV, and X-rays; (5) magnetospheric electrons and bremsstrahlung X-rays; and (6) solar cosmic rays.

Ultraviolet continuum and H2 fluorescent emission in Herbig-Haro objects 43 and 47

NASA Technical Reports Server (NTRS)

Schwartz, R. D.

1983-01-01

IUE short wavelength spectra are presented for the low excitation Herbig-Haro objects HH 43 and HH 47. In the former, several emission lines in the Lyman band of H2 from an excited state are observed which are due to fluorescence from the H Ly-alpha line pumping a lower state (that is in turn excited by a low-velocity shock wave). No evidence of highly ionized gas emission is found in the UV spectra, and both objects exhibit a UV continuum which peaks in the vicinity of 1500 A and is probably caused by H two-photon emission enhanced by low velocity shock collisional excitation.

Lyα EMISSION FROM GREEN PEAS: THE ROLE OF CIRCUMGALACTIC GAS DENSITY, COVERING, AND KINEMATICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, Alaina; Scarlata, Claudia; Martin, Crystal L.

2015-08-10

We report Hubble Space Telescope/Cosmic Origins Spectrograph observations of the Lyα emission and interstellar absorption lines in a sample of 10 star-forming galaxies at z ∼ 0.2. Selected on the basis of high equivalent width optical emission lines, the sample, dubbed “Green Peas,” make some of the best analogs for young galaxies in an early universe. We detect Lyα emission in all ten galaxies, and 9/10 show double-peaked line profiles suggestive of low H i column density. We measure Lyα/Hα flux ratios of 0.5–5.6, implying that 5%–60% of Lyα photons escape the galaxies. These data confirm previous findings that low-ionizationmore » metal absorption (LIS) lines are weaker when Lyα escape fraction and equivalent width are higher. However, contrary to previously favored interpretations of this trend, increased Lyα output cannot be the result of a varying H i covering: the Lyman absorption lines (Lyβ and higher) show a covering fraction near unity for gas with N{sub H} {sub i} ≳ 10{sup 16} cm{sup −2}. Moreover, we detect no correlation between Lyα escape and the outflow velocity of the LIS lines, suggesting that kinematic effects do not explain the range of Lyα/Hα flux ratios in these galaxies. In contrast, we detect a strong anticorrelation between the Lyα escape fraction and the velocity separation of the Lyα emission peaks, driven primarily by the velocity of the blue peak. As this velocity separation is sensitive to H i column density, we conclude that Lyα escape in these Green Peas is likely regulated by the H i column density rather than outflow velocity or H i covering fraction.« less

Impact of species variability and ‘probe-dependence’ on the detection and in vivo validation of allosteric modulation at the M4 muscarinic acetylcholine receptor

PubMed Central

Suratman, S; Leach, K; Sexton, PM; Felder, CC; Loiacono, RE; Christopoulos, A

2011-01-01

BACKGROUND AND PURPOSE We recently characterized LY2033298 as a novel allosteric modulator and agonist at M4 muscarinic acetylcholine receptors (mAChRs). Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M4 mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalize its in vivo actions. EXPERIMENTAL APPROACH LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M4 mAChRs, using assays of agonist-induced ERK1/2 or GSK-3α phosphorylation, [35S]-GTPγS binding, or effects on equilibrium binding of [3H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. KEY RESULTS LY2033298 had similar affinities for the human and mouse M4 mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M4 mAChR. At the mouse M4 mAChR, LY2033298 showed higher co-operativity with oxotremorine than with ACh or xanomeline. The different degrees of co-operativity between LY2033298 and each agonist at the mouse relative to the human M4 mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. CONCLUSIONS AND IMPLICATIONS These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M4 mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to ‘probe dependence’. This has implications for the validation of allosteric modulator actions in vivo. PMID:21198541

Impact of species variability and 'probe-dependence' on the detection and in vivo validation of allosteric modulation at the M4 muscarinic acetylcholine receptor.

PubMed

Suratman, S; Leach, K; Sexton, Pm; Felder, Cc; Loiacono, Re; Christopoulos, A

2011-04-01

We recently characterized LY2033298 as a novel allosteric modulator and agonist at M(4) muscarinic acetylcholine receptors (mAChRs). Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M(4) mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalize its in vivo actions. LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M(4) mAChRs, using assays of agonist-induced ERK1/2 or GSK-3α phosphorylation, [(35) S]-GTPγS binding, or effects on equilibrium binding of [(3) H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. LY2033298 had similar affinities for the human and mouse M(4) mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M(4) mAChR. At the mouse M(4) mAChR, LY2033298 showed higher co-operativity with oxotremorine than with ACh or xanomeline. The different degrees of co-operativity between LY2033298 and each agonist at the mouse relative to the human M(4) mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M(4) mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to 'probe dependence'. This has implications for the validation of allosteric modulator actions in vivo. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

MAPPING THE POLARIZATION OF THE RADIO-LOUD Ly α NEBULA B3 J2330+3927

DOE Office of Scientific and Technical Information (OSTI.GOV)

You, Chang; Zabludoff, Ann; Smith, Paul

Ly α nebulae, or “Ly α blobs,” are extended (up to ∼100 kpc), bright (L{sub Lyα}  ≳ 10{sup 43} erg s{sup −1}) clouds of Ly α emitting gas that tend to lie in overdense regions at z  ∼ 2–5. The origin of the Ly α emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband imaging polarimetry of a radio-loud Ly α nebula, B3 J2330+3927, at z = 3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob’s Ly α emission peak, and its radiomore » lobes align roughly with the blob’s major axis. With the SPOL polarimeter on the 6.5 m MMT telescope, we map the total (Ly α + continuum) polarization in a grid of circular apertures of a radius of 0.″6 (4.4 kpc), detecting a significant (>2 σ ) polarization fraction P {sub %} in nine apertures and achieving strong upper limits (as low as 2%) elsewhere. P{sub %} increases from <2% at ∼5 kpc from the blob center to 17% at ∼15–25 kpc. The detections are distributed asymmetrically, roughly along the nebula’s major axis. The polarization angles θ are mostly perpendicular to this axis. Comparing the Ly α flux to that of the continuum and conservatively assuming that the continuum is highly polarized (20%–100%) and aligned with the total polarization, we place lower limits on the polarization of the Ly α emission P{sub %,Lyα} ranging from no significant polarization at ∼5 kpc from the blob center to 3%–17% at 10–25 kpc. Like the total polarization, the Ly α polarization detections occur more often along the blob’s major axis.« less

An ERβ agonist induces browning of subcutaneous abdominal fat pad in obese female mice.

PubMed

Miao, Yi-Fei; Su, Wen; Dai, Yu-Bing; Wu, Wan-Fu; Huang, Bo; Barros, Rodrigo P A; Nguyen, Hao; Maneix, Laure; Guan, You-Fei; Warner, Margaret; Gustafsson, Jan-Åke

2016-12-06

Estrogen, via estrogen receptor alpha (ERα), exerts several beneficial effects on metabolism and energy homeostasis by controlling size, enzymatic activity and hormonal content of adipose tissue. The actions of estrogen on sympathetic ganglia, which are key players in the browning process, are less well known. In the present study we show that ERβ influences browning of subcutaneous adipose tissue (SAT) via its actions both on sympathetic ganglia and on the SAT itself. A 3-day-treatment with a selective ERβ agonist, LY3201, induced browning of SAT in 1-year-old obese WT and ERα -/- female mice. Browning was associated with increased expression of ERβ in the nuclei of neurons in the sympathetic ganglia, increase in tyrosine hydroxylase in both nerve terminals in the SAT and sympathetic ganglia neurons and an increase of β3-adrenoceptor in the SAT. LY3201 had no effect on browning in young female or male mice. In the case of young females browning was already maximal while in males there was very little expression of ERβ in the SAT and very little expression of the β3-adrenoceptor. The increase in both sympathetic tone and responsiveness of adipocytes to catecholamines reveals a novel role for ERβ in controlling browning of adipose tissue.

An ERβ agonist induces browning of subcutaneous abdominal fat pad in obese female mice

PubMed Central

Miao, Yi-fei; Su, Wen; Dai, Yu-bing; Wu, Wan-fu; Huang, Bo; Barros, Rodrigo P. A.; Nguyen, Hao; Maneix, Laure; Guan, You-fei; Warner, Margaret; Gustafsson, Jan-Åke

2016-01-01

Estrogen, via estrogen receptor alpha (ERα), exerts several beneficial effects on metabolism and energy homeostasis by controlling size, enzymatic activity and hormonal content of adipose tissue. The actions of estrogen on sympathetic ganglia, which are key players in the browning process, are less well known. In the present study we show that ERβ influences browning of subcutaneous adipose tissue (SAT) via its actions both on sympathetic ganglia and on the SAT itself. A 3-day-treatment with a selective ERβ agonist, LY3201, induced browning of SAT in 1-year-old obese WT and ERα−/− female mice. Browning was associated with increased expression of ERβ in the nuclei of neurons in the sympathetic ganglia, increase in tyrosine hydroxylase in both nerve terminals in the SAT and sympathetic ganglia neurons and an increase of β3-adrenoceptor in the SAT. LY3201 had no effect on browning in young female or male mice. In the case of young females browning was already maximal while in males there was very little expression of ERβ in the SAT and very little expression of the β3-adrenoceptor. The increase in both sympathetic tone and responsiveness of adipocytes to catecholamines reveals a novel role for ERβ in controlling browning of adipose tissue. PMID:27922125

The individual and combined effects of phenmetrazine and mgluR2/3 agonist LY379268 on the motivation to self-administer cocaine.

PubMed

Karkhanis, Anushree N; Beveridge, Thomas J R; Blough, Bruce E; Jones, Sara R; Ferris, Mark J

2016-09-01

The US Food and Drug Administration has not approved a treatment for cocaine addiction, possibly due in part to the fact that repeated cocaine use results in dysregulation of multiple neurotransmitter systems, including glutamate and dopamine, and an emergence of increased negative affective states and heightening motivation to take cocaine despite negative consequences. We used a combination therapy approach to assess whether modulation of both glutamate and dopamine transmission would reduce the motivation to self- administer cocaine compared to modulation of either system alone. The metabotropic glutamate 2/3 receptor agonist, LY379268, and the monoamine releaser, phenmetrazine, were used to assess their individual and combined ability to decrease the reinforcing efficacy of cocaine because they modulate glutamate and dopamine levels, respectively. Cocaine breakpoints and cocaine intake was assessed, using a progressive ratio schedule, at baseline in three groups based on dose of cocaine (0.19, 0.38, 0.75mg/kg/infusion), and following LY379268 (0.03 or 0.30mg/kg; i.p.), phenmetrazine (25mg/kg/day; osmotic minipump), and a combination of the two drugs. LY379268 and phenmetrazine alone reduced breakpoints for all doses of cocaine. The combination of the two drugs showed a concerted effect in reducing breakpoints for all doses of cocaine, with the lowest dose of cocaine reduced by as much as 70%. These data support combination therapy of dopamine and glutamate systems as an effective means to reduce the motivation to take cocaine since a combination of drugs can address neurobiological dysfunction in multiple neurotransmitter systems compared to therapies using single drugs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A potential germ cell-specific marker in Japanese flounder, Paralichthys olivaceus: identification and characterization of lymphocyte antigen 75 (Ly75/CD205)

NASA Astrophysics Data System (ADS)

Yang, Yang; Liu, Qinghua; Ma, Daoyuan; Song, Zongchen; Li, Jun

2018-04-01

Some germ cell marker genes, such as vasa, nanos, and dead end (dnd), have been identified in fish. Recently, lymphocyte antigen 75 (Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder ly75 homolog (ly75) was cloned and its expression pattern in gonads was analyzed. The full-length cDNA of ly75 was 7 346 bp, with an open reading frame (ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 kDa. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.

LY294002 enhances expression of proteins encoded by recombinant replication-defective adenoviruses via mTOR- and non-mTOR-dependent mechanisms.

PubMed

Shepelev, Mikhail V; Korobko, Elena V; Vinogradova, Tatiana V; Kopantsev, Eugene P; Korobko, Igor V

2013-03-04

Adenovirus-based drugs are efficient when combined with other anticancer treatments. Here we show that treatment with LY294002 and LY303511 upregulates expression of recombinant proteins encoded by replication-defective adenoviruses, including expression of therapeutically valuable combination of herpes simplex virus thymidine kinase controlled by human telomerase reverse transcriptase promoter (Ad-hTERT-HSVtk). In line with this, treatment with LY294002 synergized with Ad-hTERT-HSVtk infection in the presence of gancyclovir prodrug on Calu-I lung cancer cell death. The effect of LY294002 and LY303511 on adenovirus-delivered transgene expression was demonstrated in 4 human lung cancer cell lines. LY294002-induced upregulation of adenovirally delivered transgene is mediated in part by direct inhibition of mTOR protein kinase in mTORC2 signaling complex thus suggesting that anticancer drugs targeting mTOR will also enhance expression of transgenes delivered with adenoviral vectors. As both LY294002 and LY303511 are candidate prototypic anticancer drugs, and many mTOR inhibitors for cancer treatment are under development, our results have important implication for development of future therapeutic strategies with adenoviral gene delivery.

Extinction Correction Significantly Influences the Estimate of the Lyα Escape Fraction

NASA Astrophysics Data System (ADS)

An, Fang Xia; Zheng, Xian Zhong; Hao, Cai-Na; Huang, Jia-Sheng; Xia, Xiao-Yang

2017-02-01

The Lyα escape fraction is a key measure to constrain the neutral state of the intergalactic medium and then to understand how the universe was fully reionized. We combine deep narrowband imaging data from the custom-made filter NB393 and the {{{H}}}2S1 filter centered at 2.14 μm to examine the Lyα emitters and Hα emitters at the same redshift z = 2.24. The combination of these two populations allows us to determine the Lyα escape fraction at z = 2.24. Over an area of 383 arcmin2 in the Extended Chandra Deep Field South (ECDFS), 124 Lyα emitters are detected down to NB393 = 26.4 mag at the 5σ level, and 56 Hα emitters come from An et al. Of these, four have both Lyα and Hα emissions (LAHAEs). We also collect the Lyα emitters and Hα emitters at z = 2.24 in the COSMOS field from the literature, and increase the number of LAHAEs to 15 in total. About one-third of them are AGNs. We measure the individual/volumetric Lyα escape fraction by comparing the observed Lyα luminosity/luminosity density to the extinction-corrected Hα luminosity/luminosity density. We revisit the extinction correction for Hα emitters using the Galactic extinction law with color excess for nebular emission. We also adopt the Calzetti extinction law together with an identical color excess for stellar and nebular regions to explore how the uncertainties in extinction correction affect the estimate of individual and global Lyα escape fractions. In both cases, an anti-correlation between the Lyα escape fraction and dust attenuation is found among the LAHAEs, suggesting that dust absorption is responsible for the suppression of the escaping Lyα photons. However, the estimated Lyα escape fraction of individual LAHAEs varies by up to ˜3 percentage points between the two methods of extinction correction. We find the global Lyα escape fraction at z = 2.24 to be (3.7 ± 1.4)% in the ECDFS. The variation in the color excess of the extinction causes a discrepancy of ˜1 percentage point in the global Lyα escape fraction.

SILVERRUSH. V. Census of Lyα, [O III] λ5007, Hα, and [C II] 158 μm Line Emission with ∼1000 LAEs at z = 4.9–7.0 Revealed with Subaru/HSC

NASA Astrophysics Data System (ADS)

Harikane, Yuichi; Ouchi, Masami; Shibuya, Takatoshi; Kojima, Takashi; Zhang, Haibin; Itoh, Ryohei; Ono, Yoshiaki; Higuchi, Ryo; Inoue, Akio K.; Chevallard, Jacopo; Capak, Peter L.; Nagao, Tohru; Onodera, Masato; Faisst, Andreas L.; Martin, Crystal L.; Rauch, Michael; Bruzual, Gustavo A.; Charlot, Stephane; Davidzon, Iary; Fujimoto, Seiji; Hilmi, Miftahul; Ilbert, Olivier; Lee, Chien-Hsiu; Matsuoka, Yoshiki; Silverman, John D.; Toft, Sune

2018-06-01

We investigate Lyα, [O III] λ5007, Hα, and [C II] 158 μm emission from 1124 galaxies at z = 4.9–7.0. Our sample is composed of 1092 Lyα emitters (LAEs) at z = 4.9, 5.7, 6.6, and 7.0 identified by Subaru/Hyper-Suprime-Cam (HSC) narrowband surveys covered by Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) and 34 galaxies at z = 5.148–7.508 with deep ALMA [C II] 158 μm data in the literature. Fluxes of strong rest-frame optical lines of [O III] and Hα (Hβ) are constrained by significant excesses found in the SPLASH 3.6 and 4.5 μm photometry. At z = 4.9, we find that the rest-frame Hα equivalent width and the Lyα escape fraction f Lyα positively correlate with the rest-frame Lyα equivalent width {EW}}Lyα }0. The {f}Lyα }{--}{EW}}Lyα }0 correlation is similarly found at z ∼ 0–2, suggesting no evolution of the correlation over z ≃ 0–5. The typical ionizing photon production efficiency of LAEs is log(ξ ion/[Hz erg‑1]) ≃ 25.5, significantly (60%–100%) higher than those of LBGs at a given UV magnitude. At z = 5.7–7.0, there exists an interesting turnover trend that the [O III]/Hα flux ratio increases in {EW}}Lyα }0≃ 0{--}30 \\mathringA and then decreases out to {EW}}Lyα }0≃ 130 \\mathringA . We also identify an anticorrelation between a ratio of [C II] luminosity to star formation rate (L [C II]/SFR) and {EW}}Lyα }0 at the >99% confidence level.. We carefully investigate physical origins of the correlations with stellar-synthesis and photoionization models and find that a simple anticorrelation between {EW}}Lyα }0 and metallicity explains self-consistently all of the correlations of Lyα, Hα, [O III]/Hα, and [C II] identified in our study, indicating detections of metal-poor (∼0.03 Z ⊙) galaxies with {EW}}Lyα }0≃ 200 \\mathringA .

A New Constraint on Reionization from the Evolution of the Lyα Luminosity Function at z ˜ 6-7 Probed by a Deep Census of z = 7.0 Lyα Emitter Candidates to 0.3L *

NASA Astrophysics Data System (ADS)

Ota, Kazuaki; Iye, Masanori; Kashikawa, Nobunari; Konno, Akira; Nakata, Fumiaki; Totani, Tomonori; Kobayashi, Masakazu A. R.; Fudamoto, Yoshinobu; Seko, Akifumi; Toshikawa, Jun; Ichikawa, Akie; Shibuya, Takatoshi; Onoue, Masafusa

2017-07-01

We detect 20 z = 7.0 Lyα emitter (LAE) candidates to L(Lyα) ˜ 2 × 1042 erg s-1 or 0.3 {L}z=7* and in a volume of 6.1 × 105 Mpc3 in the Subaru Deep Field and the Subaru/XMM-Newton Deep Survey field by 82 hr and 37 hr of Subaru Suprime-Cam narrowband NB973 and reddest optical y-band imaging. We compare their Lyα and UV luminosity functions (LFs) and densities and Lyα equivalent widths (EWs) to those of z = 5.7, 6.6, and 7.3 LAEs from previous Suprime-Cam surveys. The Lyα LF (density) rapidly declines by a factor of ×1.5 (1.9) in L(Lyα) at z = 5.7-6.6 (160 Myr), ×1.5 (1.6) at z = 6.6-7.0 (60 Myr) at the faint end, and ×2.0 (3.8) at z = 7.0-7.3 (40 Myr). Also, in addition to the systematic decrease in EW at z = 5.7-6.6 previously found, two-thirds of the z = 7.0 LAEs detected in the UV continuum exhibit lower EWs than the z = 6.6 ones. Moreover, while the UV LF and density do not evolve at z = 5.7-6.6, they modestly decline at z = 6.6-7.0, implying galaxy evolution contributing to the decline of the Lyα LF. Comparison of the z = 7.0 Lyα LF to the one predicted by an LAE evolution model further reveals that galaxy evolution alone cannot explain all of the decline of the Lyα LF. If we attribute the discrepancy to Lyα attenuation by neutral hydrogen, the intergalactic medium transmission of Lyα photons at z = 7.0 would be {T}{Lyα }{IGM}≤slant 0.6{--}0.7. It is lower (higher) than the {T}{Lyα }{IGM} at z = 6.6 (7.3) derived by previous studies, suggesting rapid increase in neutral fraction at z > 6. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Crystal Structure of the FGFR4/LY2874455 Complex Reveals Insights into the Pan-FGFR Selectivity of LY2874455.

PubMed

Wu, Daichao; Guo, Ming; Philips, Michael A; Qu, Lingzhi; Jiang, Longying; Li, Jun; Chen, Xiaojuan; Chen, Zhuchu; Chen, Lin; Chen, Yongheng

2016-01-01

Aberrant FGFR4 signaling has been documented abundantly in various human cancers. The majority of FGFR inhibitors display significantly reduced potency toward FGFR4 compared to FGFR1-3. However, LY2874455 has similar inhibition potency for FGFR1-4 with IC50 less than 6.4 nM. To date, there is no published crystal structure of LY2874455 in complex with any kinase. To better understand the pan-FGFR selectivity of LY2874455, we have determined the crystal structure of the FGFR4 kinase domain bound to LY2874455 at a resolution of 2.35 Å. LY2874455, a type I inhibitor for FGFR4, binds to the ATP-binding pocket of FGFR4 in a DFG-in active conformation with three hydrogen bonds and a number of van der Waals contacts. After alignment of the kinase domain sequence of 4 FGFRs, and superposition of the ATP binding pocket of 4 FGFRs, our structural analyses reveal that the interactions of LY2874455 to FGFR4 are largely conserved in 4 FGFRs, explaining at least partly, the broad inhibitory activity of LY2874455 toward 4 FGFRs. Consequently, our studies reveal new insights into the pan-FGFR selectivity of LY2874455 and provide a structural basis for developing novel FGFR inhibitors that target FGFR1-4 broadly.

Analysis of the Glutamate Agonist LY404,039 Binding to Nonstatic Dopamine Receptor D2 Dimer Structures and Consensus Docking.

PubMed

Salmas, Ramin Ekhteiari; Seeman, Philip; Aksoydan, Busecan; Erol, Ismail; Kantarcioglu, Isik; Stein, Matthias; Yurtsever, Mine; Durdagi, Serdar

2017-06-21

Dopamine receptor D2 (D2R) plays an important role in the human central nervous system and is a focal target of antipsychotic agents. The D2 High R and D2 Low R dimeric models previously developed by our group are used to investigate the prediction of binding affinity of the LY404,039 ligand and its binding mechanism within the catalytic domain. The computational data obtained using molecular dynamics simulations fit well with the experimental results. The calculated binding affinities of LY404,039 using MM/PBSA for the D2 High R and D2 Low R targets were -12.04 and -9.11 kcal/mol, respectively. The experimental results suggest that LY404,039 binds to D2 High R and D2 Low R with binding affinities (K i ) of 8.2 and 1640 nM, respectively. The high binding affinity of LY404,039 in terms of binding to [ 3 H]domperidone was inhibited by the presence of a guanine nucleotide, indicating an agonist action of the drug at D2 High R. The interaction analysis demonstrated that while Asp114 was among the most critical amino acids for D2 High R binding, residues Ser193 and Ser197 were significantly more important within the binding cavity of D2 Low R. Molecular modeling analyses are extended to ensemble docking as well as structure-based pharmacophore model (E-pharmacophore) development using the bioactive conformation of LY404,039 at the binding pocket as a template and screening of small-molecule databases with derived pharmacophore models.

Evidence That Ly6C(hi) Monocytes are Protective in Acute Ischemic Stroke by Promoting M2 Macrophage Polarization.

PubMed

Chu, Hannah X; Broughton, Brad R S; Kim, Hyun Ah; Lee, Seyoung; Drummond, Grant R; Sobey, Christopher G

2015-07-01

Ly6C(hi) monocytes are generally thought to exert a proinflammatory role in acute tissue injury, although their impact after injuries to the central nervous system is poorly defined. CC chemokine receptor 2 is expressed on Ly6C(hi) monocytes and plays an essential role in their extravasation and transmigration into the brain after cerebral ischemia. We used a selective CC chemokine receptor 2 antagonist, INCB3344, to assess the effect of Ly6C(hi) monocytes recruited into the brain early after ischemic stroke. Male C57Bl/6J mice underwent occlusion of the middle cerebral artery for 1 hour followed by 23 hours of reperfusion. Mice were administered either vehicle (dimethyl sulfoxide/carboxymethylcellulose) or INCB3344 (10, 30 or 100 mg/kg IP) 1 hour before ischemia and at 2 and 6 hours after ischemia. At 24 hours, we assessed functional outcomes, infarct volume, and quantified the immune cells in blood and brain by flow cytometry or immunofluorescence. Gene expression of selected inflammatory markers was assessed by quantitative polymerase chain reaction. Ly6C(hi) monocytes were increased 3-fold in the blood and 10-fold in the brain after stroke, and these increases were selectively prevented by INCB3344 in a dose-dependent manner. Mice treated with INCB3344 exhibited markedly worse functional outcomes and larger infarct volumes, in association with reduced M2 polarization and increased peroxynitrite production in macrophages, compared with vehicle-treated mice. Our data suggest that Ly6C(hi) monocytes exert an acute protective effect after ischemic stroke to limit brain injury and functional deficit that involves promotion of M2 macrophage polarization. © 2015 American Heart Association, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Micheva, Genoveva; Oey, M. S.; Jaskot, Anne E.

We present the remarkable discovery that the dwarf irregular galaxy NGC 2366 is an excellent analog of the Green Pea (GP) galaxies, which are characterized by extremely high ionization parameters. The similarities are driven predominantly by the giant H ii region Markarian 71 (Mrk 71). We compare the system with GPs in terms of morphology, excitation properties, specific star-formation rate, kinematics, absorption of low-ionization species, reddening, and chemical abundance, and find consistencies throughout. Since extreme GPs are associated with both candidate and confirmed Lyman continuum (LyC) emitters, Mrk 71/NGC 2366 is thus also a good candidate for LyC escape. Themore » spatially resolved data for this object show a superbubble blowout generated by mechanical feedback from one of its two super star clusters (SSCs), Knot B, while the extreme ionization properties are driven by the ≲1 Myr-old, enshrouded SSC Knot A, which has ∼10 times higher ionizing luminosity. Very massive stars (>100 M {sub ⊙}) may be present in this remarkable object. Ionization-parameter mapping indicates that the blowout region is optically thin in the LyC, and the general properties also suggest LyC escape in the line of sight. Mrk 71/NGC 2366 does differ from GPs in that it is one to two orders of magnitude less luminous. The presence of this faint GP analog and candidate LyC emitter (LCE) so close to us suggests that LCEs may be numerous and commonplace, and therefore could significantly contribute to the cosmic ionizing budget. Mrk 71/NGC 2366 offers an unprecedentedly detailed look at the viscera of a candidate LCE, and could clarify the mechanisms of LyC escape.« less

E-2 Systems Approach to Training: Development, Implementation, Evaluation, and Revision.

DTIC Science & Technology

1979-08-01

1 1 2.0 xxII 2 2 3.3 XXIII 5 1.5 2 3.3 XXIV 1 2 1.5 2.- XXV 4 1 39 NAVTRAEQUIPCEN 78-C-0045-1 TABLE 2. (CONTINUED) lOIIhLI CARRIL CLASSROOM 1 SI-8 - 2...i i cvc r ed i -i a e ext reP me ly tnt e r,, t I n ______ b_ h. n te re s tinr% __________c. bo r ing _________d. extreme-ly bu )ring o. .IA 1

75 FR 49955 - Hung Thien Ly, M.D.; Revocation of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Hung Thien Ly, M.D.; Revocation of... Enforcement Administration, issued an Order to Show Cause to Hung Thien Ly, M.D. (Respondent), of McRae..., BL8586147, issued to Hung Thien Ly, M.D., be, and it hereby is, revoked. I further order that any pending...

Myostatin antibody (LY2495655) in older weak fallers: a proof-of-concept, randomised, phase 2 trial

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Myostatin inhibits skeletal muscle growth. The humanised monoclonal antibody LY2495655 (LY) binds and neutralises myostatin. We aimed to test whether LY increases appendicular lean body mass (aLBM) and improves physical performance in older individuals who have had recent falls and low m...

Targeting PI3K-AKT-mTOR by LY3023414 inhibits human skin squamous cell carcinoma cell growth in vitro and in vivo.

PubMed

Zou, Ying; Ge, Minggai; Wang, Xuemin

2017-08-19

Abnormal activation of PI3K-AKT-mTOR signaling is detected in human skin squamous cell carcinoma (SCC). LY3023414 is a novel, potent, and orally bio-available PI3K-AKT-mTOR inhibitor. Its activity against human skin SCC cells was tested. We demonstrated that LY3023414 was cytotoxic when added to established (A431 line) and primary (patient-derived) human skin SCC cells. LY3023414 induced G0/1-S arrest and inhibited proliferation of skin SCC cells. Moreover, LY3023414 induced activation of caspase-3/-9 and apoptosis in skin SCC cells. Intriguingly, LY3023414 was yet non-cytotoxic nor pro-apoptotic to normal human skin cells (melanocytes, keratinocytes and fibroblasts). At the molecular level, LY3023414 blocked PI3K-AKT-mTOR activation in skin SCC cells, as it dephosphorylated PI3K-AKT-mTOR substrates: P85, AKT and S6K1. In vivo studies showed that oral administration of LY3023414 at well-tolerated doses inhibited A431 xenograft tumor growth in severe combined immunodeficiency (SCID) mice. AKT-mTOR activation in LY3023414-treated tumors was also largely inhibited. Together, these results suggest that targeting PI3K-AKT-mTOR by LY3023414 inhibits human skin SCC cell growth in vitro and in vivo, establishing the rationale for further clinical testing. Copyright © 2017 Elsevier Inc. All rights reserved.

Haro 11: Where is the Lyman Continuum Source?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keenan, Ryan P.; Oey, M. S.; Jaskot, Anne E.

2017-10-10

Identifying the mechanism by which high-energy Lyman continuum (LyC) photons escaped from early galaxies is one of the most pressing questions in cosmic evolution. Haro 11 is the best known local LyC-leaking galaxy, providing an important opportunity to test our understanding of LyC escape. The observed LyC emission in this galaxy presumably originates from one of the three bright, photoionizing knots known as A, B, and C. It is known that Knot C has strong Ly α emission, and Knot B hosts an unusually bright ultraluminous X-ray source, which may be a low-luminosity active galactic nucleus. To clarify the LyCmore » source, we carry out ionization-parameter mapping (IPM) by obtaining narrow-band imaging from the Hubble Space Telescope WFC3 and ACS cameras to construct spatially resolved ratio maps of [O iii]/[O ii] emission from the galaxy. IPM traces the ionization structure of the interstellar medium and allows us to identify optically thin regions. To optimize the continuum subtraction, we introduce a new method for determining the best continuum scale factor derived from the mode of the continuum-subtracted, image flux distribution. We find no conclusive evidence of LyC escape from Knots B or C, but instead we identify a high-ionization region extending over at least 1 kpc from Knot A. This knot shows evidence of an extremely young age (≲1 Myr), perhaps containing very massive stars (>100 M {sub ⊙}). It is weak in Ly α , so if it is confirmed as the LyC source, our results imply that LyC emission may be independent of Ly α emission.« less

LY294002 inhibits glucocorticoid-induced COX-2 gene expression in cardiomyocytes through a phosphatidylinositol 3 kinase-independent mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun Haipeng; Xu Beibei; Sheveleva, Elena

2008-10-01

Glucocorticoids induce COX-2 expression in rat cardiomyocytes. While investigating whether phosphatidylinositol 3 kinase (PI3K) plays a role in corticosterone (CT)-induced COX-2, we found that LY294002 (LY29) but not wortmannin (WM) attenuates CT from inducing COX-2 gene expression. Expression of a dominant-negative mutant of p85 subunit of PI3K failed to inhibit CT from inducing COX-2 expression. CT did not activate PI3K/AKT signaling pathway whereas LY29 and WM decreased the activity of PI3K. LY303511 (LY30), a structural analogue and a negative control for PI3K inhibitory activity of LY29, also suppressed COX-2 induction. These data suggest PI3K-independent mechanisms in regulating CT-induced COX-2 expression.more » LY29 and LY30 do not inhibit glucocorticoid receptor transactivity. Both compounds have been reported to inhibit Casein Kinase 2 activity and modulate potassium and calcium levels independent of PI3K, while LY29 has been reported to inhibit mammalian Target of Rapamycin (mTOR), and DNA-dependent Protein Kinase (DNA-PK). Inhibitor of Casein Kinase 2 (CK2), mTOR or DNA-PK failed to prevent CT from inducing COX-2 expression. Tetraethylammonium (TEA), a potassium channel blocker, and nimodipine, a calcium channel blocker, both attenuated CT from inducing COX-2 gene expression. CT was found to increase intracellular Ca{sup 2+} concentration, which can be inhibited by LY29, TEA or nimodipine. These data suggest a possible role of calcium instead of PI3K in CT-induced COX-2 expression in cardiomyocytes.« less

Target specificity, in vivo pharmacokinetics, and efficacy of the putative STAT3 inhibitor LY5 in osteosarcoma, Ewing's sarcoma, and rhabdomyosarcoma.

PubMed

Yu, Peter Y; Gardner, Heather L; Roberts, Ryan; Cam, Hakan; Hariharan, Seethalakshmi; Ren, Ling; LeBlanc, Amy K; Xiao, Hui; Lin, Jiayuh; Guttridge, Denis C; Mo, Xiaokui; Bennett, Chad E; Coss, Christopher C; Ling, Yonghua; Phelps, Mitch A; Houghton, Peter; London, Cheryl A

2017-01-01

STAT3 is a transcription factor involved in cytokine and receptor kinase signal transduction that is aberrantly activated in a variety of sarcomas, promoting metastasis and chemotherapy resistance. The purpose of this work was to develop and test a novel putative STAT3 inhibitor, LY5. An in silico fragment-based drug design strategy was used to create LY5, a small molecule inhibitor that blocks the STAT3 SH2 domain phosphotyrosine binding site, inhibiting homodimerization. LY5 was evaluated in vitro demonstrating good biologic activity against rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma cell lines at high nanomolar/low micromolar concentrations, as well as specific inhibition of STAT3 phosphorylation without effects on other STAT3 family members. LY5 exhibited excellent oral bioavailability in both mice and healthy dogs, and drug absorption was enhanced in the fasted state with tolerable dosing in mice at 40 mg/kg BID. However, RNAi-mediated knockdown of STAT3 did not phenocopy the biologic effects of LY5 in sarcoma cell lines. Moreover, concentrations needed to inhibit ex vivo metastasis growth using the PuMA assay were significantly higher than those needed to inhibit STAT3 phosphorylation in vitro. Lastly, LY5 treatment did not inhibit the growth of sarcoma xenografts or prevent pulmonary metastasis in mice. LY5 is a novel small molecule inhibitor that effectively inhibits STAT3 phosphorylation and cell proliferation at nanomolar concentrations. LY5 demonstrates good oral bioavailability in mice and dogs. However LY5 did not decrease tumor growth in xenograft mouse models and STAT3 knockdown did not induce concordant biologic effects. These data suggest that the anti-cancer effects of LY5 identified in vitro were not mediated through STAT3 inhibition.

The Redshift Evolution of Rest-UV Spectroscopic Properties in Lyman-break Galaxies at z ∼ 2–4

NASA Astrophysics Data System (ADS)

Du, Xinnan; Shapley, Alice E.; Reddy, Naveen A.; Jones, Tucker; Stark, Daniel P.; Steidel, Charles C.; Strom, Allison L.; Rudie, Gwen C.; Erb, Dawn K.; Ellis, Richard S.; Pettini, Max

2018-06-01

We present the first comprehensive evolutionary analysis of the rest-frame UV spectroscopic properties of star-forming galaxies at z ∼ 2–4. We match samples at different redshifts in UV luminosity and stellar mass, and perform systematic measurements of spectral features and stellar population modeling. By creating composite spectra grouped according to Lyα equivalent width (EW) and various galaxy properties, we study the evolutionary trends among Lyα, low- and high-ionization interstellar (LIS and HIS) absorption features, and integrated galaxy properties. We also examine the redshift evolution of Lyα and LIS absorption kinematics, and fine-structure emission EWs. The connections among the strengths of Lyα, LIS lines, and dust extinction are redshift independent, as is the decoupling of the Lyα and HIS line strengths, and the bulk outflow kinematics as traced by the LIS lines. Stronger Lyα emission is observed at higher redshift at fixed UV luminosity, stellar mass, SFR, and age. Much of this variation in the average Lyα strength with redshift, and the variation in Lyα strength at fixed redshift, can be explained in terms of variations in the neutral gas covering fraction and/or dust content in the ISM and CGM. However, based on the connection between Lyα and C III] emission strengths, we additionally find evidence for variations in the intrinsic production rate of Lyα photons at the highest Lyα EWs. The challenge now is to understand the observed evolution of the neutral gas covering fraction and dust extinction within a coherent model for galaxy formation, and make robust predictions for the escape of ionizing radiation at z > 6.

Listeria monocytogenes infection enhances the interaction between rat non-classical MHC-Ib molecule and Ly49 receptors.

PubMed

Shegarfi, Hamid; Kane, Kevin P; Nestvold, Janne

2018-05-01

Murine NK cell Ly49 receptors, functionally analogous to KIRs in humans recognize MHC class I molecules and play a key role in controlling NK cell function. We have previously shown that the paired activating Ly49s4 and inhibitory Ly49i4 receptors recognize undefined non-classical MHC-Ib ligands from the RT1-CE region in rats. Here, the RT1-CE16 gene of the RT1 d haplotype was stably transfected into the mouse RAW macrophage cell line, termed RAW-CE16 d cells. Combining RAW-CE16 d cells with Ly49 expressing reporter cells demonstrated Ly49i4 and Ly49s4 specificity for CE16 d . The Ly49s4/i4:CE16 d interaction was confirmed by specific MHC-I blocking monoclonal Abs. Further, we used our in vitro model to study the effect of Listeria monocytogenes (LM) on CE16 d after infection. LM infection and IFN-γ stimulation both led to enhanced CE16 d expression on the surface of transfected RAW-CE16 d cells. Interestingly, the reporter cells displayed increased response to LM-infected RAW-CE16 d cells compared with IFN-γ-treated RAW-CE16 d cells, suggesting a fundamental difference between these stimuli in supporting enhanced Ly49 recognition of CE16 d . Collectively, our data show that Ly49s4 and Ly49i4 recognize the non-classical RT1-CE16 d molecule, which in turn is up-regulated during LM infection and thereby may contribute to NK-mediated responses against infected cells.

Comparing the Antiseizure and Neuroprotective Efficacy of LY293558, Diazepam, Caramiphen, and LY293558-Caramiphen Combination against Soman in a Rat Model Relevant to the Pediatric Population

PubMed Central

Apland, James P.; Aroniadou-Anderjaska, Vassiliki; Figueiredo, Taiza H.; Pidoplichko, Volodymyr I.; Rossetti, Katia

2018-01-01

The currently Food and Drug Administration–approved anticonvulsant for the treatment of status epilepticus (SE) induced by nerve agents is the benzodiazepine diazepam; however, diazepam does not appear to offer neuroprotective benefits. This is of particular concern with respect to the protection of children because, in the developing brain, synaptic transmission mediated via GABAA receptors, the target of diazepam, is weak. In the present study, we exposed 21-day-old male rats to 1.2 × LD50 soman and compared the antiseizure, antilethality, and neuroprotective efficacy of diazepam (10 mg/kg), LY293558 (an AMPA/GluK1 receptor antagonist; 15 mg/kg), caramiphen (CRM, an antimuscarinic with NMDA receptor-antagonistic properties; 50 mg/kg), and LY293558 (15 mg/kg) + CRM (50 mg/kg), administered 1 hour after exposure. Diazepam, LY293558, and LY293558 + CRM, but not CRM alone, terminated SE; LY293558 + CRM treatment acted significantly faster and produced a survival rate greater than 85%. Thirty days after soman exposure, neurodegeneration in limbic regions was most severe in the CRM-treated group, minimal to severe—depending on the region—in the diazepam group, absent to moderate in the LY293558-treated group, and totally absent in the LY293558 + CRM group. Amygdala and hippocampal atrophy, a severe reduction in spontaneous inhibitory activity in the basolateral amygdala, and increased anxiety-like behavior in the open-field and acoustic startle response tests were present in the diazepam and CRM groups, whereas the LY293558 and LY293558 + CRM groups did not differ from controls. The combined administration of LY293558 and CRM, by blocking mainly AMPA, GluK1, and NMDA receptors, is a very effective anticonvulsant and neuroprotective therapy against soman in young rats. PMID:29467308

The Grism Lens-Amplified Survey from Space (GLASS). III. A Census of Lyα Emission at z ≳ 7 from HST Spectroscopy

NASA Astrophysics Data System (ADS)

Schmidt, K. B.; Treu, T.; Bradač, M.; Vulcani, B.; Huang, K.-H.; Hoag, A.; Maseda, M.; Guaita, L.; Pentericci, L.; Brammer, G. B.; Dijkstra, M.; Dressler, A.; Fontana, A.; Henry, A. L.; Jones, T. A.; Mason, C.; Trenti, M.; Wang, X.

2016-02-01

We present a census of Lyα emission at z≳ 7, utilizing deep near-infrared Hubble Space Telescope grism spectroscopy from the first six completed clusters of the Grism Lens-Amplified Survey from Space (GLASS). In 24/159 photometrically selected galaxies we detect emission lines consistent with Lyα in the GLASS spectra. Based on the distribution of signal-to-noise ratios and on simulations, we expect the completeness and the purity of the sample to be 40%-100% and 60%-90%, respectively. For the objects without detected emission lines we show that the observed (not corrected for lensing magnification) 1σ flux limits reach 5 × 10-18 erg s-1 cm-2 per position angle over the full wavelength range of GLASS (0.8-1.7 μm). Based on the conditional probability of Lyα emission measured from the ground at z˜ 7, we would have expected 12-18 Lyα emitters. This is consistent with the number of detections, within the uncertainties, confirming the drop in Lyα emission with respect to z˜ 6. Deeper follow-up spectroscopy, here exemplified by Keck spectroscopy, is necessary to improve our estimates of completeness and purity and to confirm individual candidates as true Lyα emitters. These candidates include a promising source at z = 8.1. The spatial extent of Lyα in a deep stack of the most convincing Lyα emitters with < z> = 7.2 is consistent with that of the rest-frame UV continuum. Extended Lyα emission, if present, has a surface brightness below our detection limit, consistent with the properties of lower-redshift comparison samples. From the stack we estimate upper limits on rest-frame UV emission line ratios and find {f}{{C}{{IV}}}/{f}{Lyα }≲ 0.32 and {f}{{C}{{III}}]}/{f}{Lyα }≲ 0.23, in good agreement with other values published in the literature.

Experimental Estimation of CLASP Spatial Resolution: Results of the Instrument's Optical Alignment

NASA Technical Reports Server (NTRS)

Giono, Gabrial; Katsukawa, Yukio; Ishikawa, Ryoko; Narukage, Noriyuki; Bando, Takamasa; Kano, Ryohei; Suematsu, Yoshinori; Kobayashi, Ken; Winebarger, Amy; Auchere, Frederic

2015-01-01

The Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) is a sounding-rocket experiment currently being built at the National Astronomical Observatory of Japan. This instrument aims to probe for the first time the magnetic field strength and orientation in the solar upper-chromosphere and lower-transition region. CLASP will measure the polarization of the Lyman-Alpha line (121.6nm) with an unprecedented accuracy, and derive the magnetic field information through the Hanle effect. Although polarization accuracy and spectral resolution are crucial for the Hanle effect detection, spatial resolution is also important to get reliable context image via the slit-jaw camera. As spatial resolution is directly related with the alignment of optics, it is also a good way of ensuring the alignment of the instrument to meet the scientific requirement. This poster will detail the experiments carried out to align CLASP's optics (telescope and spectrograph), as both part of the instrument were aligned separately. The telescope was aligned in double-pass mode, and a laser interferometer (He-Ne) was used to measure the telescope's wavefront error (WFE). The secondary mirror tilt and position were adjusted to remove comas and defocus aberrations from the WFE. Effect of gravity on the WFE measurement was estimated and the final WFE derived in zero-g condition for CLASP telescope will be presented. In addition, an estimation of the spot shape and size derived from the final WFE will also be shown. The spectrograph was aligned with a custom procedure: because Ly-??light is absorbed by air, the spectrograph's off-axis parabolic mirrors were aligned in Visible Light (VL) using a custom-made VL grating instead of the flight Ly-? grating. Results of the alignment in Visible Light will be shown and the spot shape recorded with CCDs at various position along the slit will be displayed. Results from both alignment experiment will be compared to the design requirement, and will be combined in order to estimate CLASP spatial resolution after its alignment in visible light.

The Relationship between Stellar Populations and Lyα Emission in Lyman Break Galaxies

NASA Astrophysics Data System (ADS)

Kornei, Katherine A.; Shapley, Alice E.; Erb, Dawn K.; Steidel, Charles C.; Reddy, Naveen A.; Pettini, Max; Bogosavljević, Milan

2010-03-01

We present the results of a photometric and spectroscopic survey of 321 Lyman break galaxies (LBGs) at z~ 3 to investigate systematically the relationship between Lyα emission and stellar populations. Lyα equivalent widths (W Lyα) were calculated from rest-frame UV spectroscopy and optical/near-infrared/Spitzer photometry was used in population synthesis modeling to derive the key properties of age, dust extinction, star formation rate (SFR), and stellar mass. We directly compare the stellar populations of LBGs with and without strong Lyα emission, where we designate the former group (W Lyα>= 20 Å) as Lyα emitters (LAEs) and the latter group (W Lyα< 20 Å) as non-LAEs. This controlled method of comparing objects from the same UV luminosity distribution represents an improvement over previous studies in which the stellar populations of LBGs and narrowband-selected LAEs were contrasted, where the latter were often intrinsically fainter in broadband filters by an order of magnitude simply due to different selection criteria. Using a variety of statistical tests, we find that Lyα equivalent width and age, SFR, and dust extinction, respectively, are significantly correlated in the sense that objects with strong Lyα emission also tend to be older, lower in SFR, and less dusty than objects with weak Lyα emission, or the line in absorption. We accordingly conclude that, within the LBG sample, objects with strong Lyα emission represent a later stage of galaxy evolution in which supernovae-induced outflows have reduced the dust covering fraction. We also examined the hypothesis that the attenuation of Lyα photons is lower than that of the continuum, as proposed by some, but found no evidence to support this picture. Based, in part, on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

Intron retention and transcript chimerism conserved across mammals: Ly6g5b and Csnk2b-Ly6g5b as examples

PubMed Central

2013-01-01

Background Alternative splicing (AS) is a major mechanism for modulating gene expression of an organism, allowing the synthesis of several structurally and functionally distinct mRNAs and protein isoforms from a unique gene. Related to AS is the Transcription Induced Chimerism (TIC) or Tandem Chimerism, by which chimeric RNAs between adjacent genes can be found, increasing combinatorial complexity of the proteome. The Ly6g5b gene presents particular behaviours in its expression, involving an intron retention event and being capable to form RNA chimera transcripts with the upstream gene Csnk2b. We wanted to characterise these events more deeply in four tissues in six different mammals and analyse their protein products. Results While canonical Csnk2b isoform was widely expressed, Ly6g5b canonical isoform was less ubiquitous, although the Ly6g5b first intron retained transcript was present in all the tissues and species analysed. Csnk2b-Ly6g5b chimeras were present in all the samples analysed, but with restricted expression patterns. Some of these chimeric transcripts maintained correct structural domains from Csnk2b and Ly6g5b. Moreover, we found Csnk2b, Ly6g5b, and Csnk2b-Ly6g5b transcripts that present exon skipping, alternative 5' and 3' splice site and intron retention events. These would generate truncated or aberrant proteins whose role remains unknown. Some chimeric transcripts would encode CSNK2B proteins with an altered C-terminus, which could affect its biological function broadening its substrate specificity. Over-expression of human CSNK2B, LY6G5B, and CSNK2B-LY6G5B proteins, show different patterns of post-translational modifications and cell distribution. Conclusions Ly6g5b intron retention and Csnk2b-Ly6g5b transcript chimerism are broadly distributed in tissues of different mammals. PMID:23521802

Regulation of expression of two LY-6 family genes by intron retention and transcription induced chimerism

PubMed Central

Calvanese, Vincenzo; Mallya, Meera; Campbell, R Duncan; Aguado, Begoña

2008-01-01

Background Regulation of the expression of particular genes can rely on mechanisms that are different from classical transcriptional and translational control. The LY6G5B and LY6G6D genes encode LY-6 domain proteins, whose expression seems to be regulated in an original fashion, consisting of an intron retention event which generates, through an early premature stop codon, a non-coding transcript, preventing expression in most cell lines and tissues. Results The MHC LY-6 non-coding transcripts have shown to be stable and very abundant in the cell, and not subject to Nonsense Mediated Decay (NMD). This retention event appears not to be solely dependent on intron features, because in the case of LY6G5B, when the intron is inserted in the artificial context of a luciferase expression plasmid, it is fully spliced but strongly stabilises the resulting luciferase transcript. In addition, by quantitative PCR we found that the retained and spliced forms are differentially expressed in tissues indicating an active regulation of the non-coding transcript. EST database analysis revealed that these genes have an alternative expression pathway with the formation of Transcription Induced Chimeras (TIC). This data was confirmed by RT-PCR, revealing the presence of different transcripts that would encode the chimeric proteins CSNKβ-LY6G5B and G6F-LY6G6D, in which the LY-6 domain would join to a kinase domain and an Ig-like domain, respectively. Conclusion In conclusion, the LY6G5B and LY6G6D intron-retained transcripts are not subjected to NMD and are more abundant than the properly spliced forms. In addition, these genes form chimeric transcripts with their neighbouring same orientation 5' genes. Of interest is the fact that the 5' genes (CSNKβ or G6F) undergo differential splicing only in the context of the chimera (CSNKβ-LY6G5B or G6F-LY6G6C) and not on their own. PMID:18817541

Inclusion of live yeast and mannan-oligosaccharides in high grain-based diets for sheep: Ruminal parameters, inflammatory response and rumen morphology

PubMed Central

Jacovaci, Fernando Alberto; Cabreira Jobim, Clóves; Bolson, Dheyme Cristina; Pratti Daniel, João Luiz

2018-01-01

The objective of this study was to evaluate the effects of dietary supplementation with live yeast (Saccharomyces cerevisiae), mannan-oligosaccharides and the combination of these additives on the inflammatory response, ruminal parameters and rumen morphology of sheep fed a high grain-based diet. Thirty-Two Dorper x Santa Ines crossbred lambs with an average weight of 24±2 kg were distributed in a completely randomized design. The animals were housed in individual stalls and fed ad libitum. Diet treatments were: Control (without additive); LY (2 g/kg DM of live yeast, Saccharomyces cerevisiae), MOS (2 g/kg DM of mannan-oligosaccharides) and LY+MOS (2 g/kg DM of LY + 2 g/kg DM of MOS). The experiment lasted 42 days. The supplementation with MOS alone and the additives combination resulted in increased ruminal pH (P<0.01), while the total concentrations of short chain fatty acids (SCFA) in the rumen were higher (P<0.05) only in the diets with LY and MOS. Ammonia (NH3) concentration in the rumen decreased (P<0.04) with the additives usage. Diets with LY, MOS and with additives combination reduced (P<0.01) the levels of lipopolysaccharides (LPS) in the plasma with values of 0.46; 0.44 and 0.04 EU/mL, respectively when compared to the control (0.93 EU/mL). MOS and LY+MOS treatments had reduced stratum corneum thickness (P<0.01) in comparison to the control treatment. The total thickness of ruminal epithelium was lower with the addition of MOS in the diet (P<0.03) than with LY additive. The incidence and severity of hepatic abscesses in animals whose diet was supplemented with LY and LY+MOS was lower (P<0.05) than in animals fed the control diet. The use of LY, MOS and LY+MOS in the high-concentrate diets for sheep reduced NH3 concentrations and LPS translocation into the bloodstream. Diets containing MOS and LY+MOS enhanced the health of the ruminal epithelium by reducing the thickness of the stratum corneum, and diets containing LY and LY+MOS decreased the incidence and severity of hepatic abscesses. PMID:29466450

Accelerated Evolution of the Lyα Luminosity Function at z >~ 7 Revealed by the Subaru Ultra-deep Survey for Lyα Emitters at z = 7.3

NASA Astrophysics Data System (ADS)

Konno, Akira; Ouchi, Masami; Ono, Yoshiaki; Shimasaku, Kazuhiro; Shibuya, Takatoshi; Furusawa, Hisanori; Nakajima, Kimihiko; Naito, Yoshiaki; Momose, Rieko; Yuma, Suraphong; Iye, Masanori

2014-12-01

We present the ultra-deep Subaru narrowband imaging survey for Lyα emitters (LAEs) at z = 7.3 in the Subaru/XMM-Newton Deep Survey (SXDS) and Cosmic Evolution Survey (COSMOS) fields (~0.5 deg2) with a total integration time of 106 hr. Exploiting our new sharp bandwidth filter, NB101, installed on the Suprime-Cam, we have reached L(Lyα) = 2.4 × 1042 erg s-1 (5σ) for z = 7.3 LAEs, about four times deeper than previous Subaru z >~ 7 studies, which allows us to reliably investigate the evolution of the Lyα luminosity function (LF) for the first time down to the luminosity limit same as those of Subaru z = 3.1-6.6 LAE samples. Surprisingly, we only find three and four LAEs in the SXDS and COSMOS fields, respectively, while one expects a total of ~65 LAEs by our survey in the case of no Lyα LF evolution from z = 6.6 to 7.3. We identify a decrease of the Lyα LF from z = 6.6 to 7.3 at the >90% confidence level from our z = 7.3 Lyα LF with the best-fit Schechter parameters of L*{Lyα } = 2.7+8.0-1.2 × 1042 {erg} {s}-1 and φ * = 3.7+17.6-3.3 × 10-4 {Mpc}-3 for a fixed α = -1.5. Moreover, the evolution of the Lyα LF is clearly accelerated at z > 6.6 beyond the measurement uncertainties including cosmic variance. Because no such accelerated evolution of the UV-continuum LF or the cosmic star formation rate (SFR) is found at z ~ 7, but suggested only at z > 8, this accelerated Lyα LF evolution is explained by physical mechanisms different from a pure SFR decrease but related to the Lyα production and escape in the process of cosmic reionization. Because a simple accelerating increase of intergalactic medium neutral hydrogen absorbing Lyα cannot be reconciled with Thomson scattering of optical depth measurements from WMAP and Planck, our findings may support new physical pictures suggested by recent theoretical studies, such as the existence of HI clumpy clouds within cosmic ionized bubbles that are selectively absorbing Lyα and the large ionizing photon escape fraction of galaxies causing weak Lyα emission.

Slicing COSMOS with SC4K: the evolution of typical Ly α emitters and the Ly α escape fraction from z ˜ 2 to 6

NASA Astrophysics Data System (ADS)

Sobral, David; Santos, Sérgio; Matthee, Jorryt; Paulino-Afonso, Ana; Ribeiro, Bruno; Calhau, João; Khostovan, Ali A.

2018-06-01

We present and explore deep narrow- and medium-band data obtained with the Subaru and the Isaac Newton Telescopes in the ˜2 deg2 COSMOS field. We use these data as an extremely wide, low-resolution (R ˜ 20-80) Integral Field Unit survey to slice through the COSMOS field and obtain a large sample of ˜4000 Ly α emitters (LAEs) from z ˜ 2 to 6 in 16 redshift slices (SC4K). We present new Ly α luminosity functions (LFs) covering a comoving volume of ˜108 Mpc3. SC4K extensively complements ultradeep surveys, jointly covering over 4 dex in Ly α luminosity and revealing a global (2.5 < z < 6) synergy LF with α =-1.93^{+0.12}_{-0.12}, log _{10}Φ ^*_{Lyα }={-3.45^{+0.22}_{-0.29}} Mpc-3, and log _{10}L^*_{Lyα }={42.93^{+0.15}_{-0.11}} erg s-1. The Schechter component of the Ly α LF reveals a factor ˜5 rise in L^*_Lyα and a ˜7 × decline in Φ ^*_{Lyα } from z ˜ 2 to 6. The data reveal an extra power-law (or Schechter) component above LLy α ≈ 1043.3 erg s-1 at z ˜ 2.2-3.5 and we show that it is partially driven by X-ray and radio active galactic nucleus (AGN), as their Ly α LF resembles the excess. The power-law component vanishes and/or is below our detection limits above z > 3.5, likely linked with the evolution of the AGN population. The Ly α luminosity density rises by a factor ˜2 from z ˜ 2 to 3 but is then found to be roughly constant (1.1^{+0.2}_{-0.2}× 10^{40} erg s-1 Mpc-3) to z ˜ 6, despite the ˜0.7 dex drop in ultraviolet (UV) luminosity density. The Ly α/UV luminosity density ratio rises from 4 ± 1 per cent to 30 ± 6 per cent from z ˜ 2.2 to 6. Our results imply a rise of a factor of ≈2 in the global ionization efficiency (ξion) and a factor ≈4 ± 1 in the Ly α escape fraction from z ˜ 2 to 6, hinting for evolution in both the typical burstiness/stellar populations and even more so in the typical interstellar medium conditions allowing Ly α photons to escape.

Cytokines Induce Faster Membrane Diffusion of MHC Class I and the Ly49A Receptor in a Subpopulation of Natural Killer Cells

PubMed Central

Bagawath-Singh, Sunitha; Staaf, Elina; Stoppelenburg, Arie Jan; Spielmann, Thiemo; Kambayashi, Taku; Widengren, Jerker; Johansson, Sofia

2016-01-01

Cytokines have the potential to drastically augment immune cell activity. Apart from altering the expression of a multitude of proteins, cytokines also affect immune cell dynamics. However, how cytokines affect the molecular dynamics within the cell membrane of immune cells has not been addressed previously. Molecular movement is a vital component of all biological processes, and the rate of motion is, thus, an inherent determining factor for the pace of such processes. Natural killer (NK) cells are cytotoxic lymphocytes, which belong to the innate immune system. By fluorescence correlation spectroscopy, we investigated the influence of cytokine stimulation on the membrane density and molecular dynamics of the inhibitory receptor Ly49A and its ligand, the major histocompatibility complex class I allele H-2Dd, in freshly isolated murine NK cells. H-2Dd was densely expressed and diffused slowly in resting NK cells. Ly49A was expressed at a lower density and diffused faster. The diffusion rate in resting cells was not altered by disrupting the actin cytoskeleton. A short-term stimulation with interleukin-2 or interferon-α + β did not change the surface density of moving H-2Dd or Ly49A, despite a slight upregulation at the cellular level of H-2Dd by interferon-α + β, and of Ly49A by IL-2. However, the molecular diffusion rates of both H-2Dd and Ly49A increased significantly. A multivariate analysis revealed that the increased diffusion was especially marked in a subpopulation of NK cells, where the diffusion rate was increased around fourfold compared to resting NK cells. After IL-2 stimulation, this subpopulation of NK cells also displayed lower density of Ly49A and higher brightness per entity, indicating that Ly49A may homo-cluster to a larger extent in these cells. A faster diffusion of inhibitory receptors could enable a faster accumulation of these molecules at the immune synapse with a target cell, eventually leading to a more efficient NK cell response. It has previously been assumed that cytokines regulate immune cells primarily via alterations of protein expression levels or posttranslational modifications. These findings suggest that cytokines may also modulate immune cell efficiency by increasing the molecular dynamics early on in the response. PMID:26870035

Discovery of Ubiquitous Fast-Propagating Intensity Disturbances by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)

NASA Astrophysics Data System (ADS)

Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.; Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.; Auchère, F.; Trujillo Bueno, J.; Asensio Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.

2016-12-01

High-cadence observations by the slit-jaw (SJ) optics system of the sounding rocket experiment known as the Chromospheric Lyman Alpha Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances that recurrently propagate in either the chromosphere or the transition region or both at a speed much higher than the speed of sound. The CLASP/SJ instrument provides a time series of two-dimensional images taken with broadband filters centered on the Lyα line at a 0.6 s cadence. The multiple fast-propagating intensity disturbances appear in the quiet Sun and in an active region, and they are clearly detected in at least 20 areas in a field of view of 527″ × 527″ during the 5 minute observing time. The apparent speeds of the intensity disturbances range from 150 to 350 km s-1, and they are comparable to the local Alfvén speed in the transition region. The intensity disturbances tend to propagate along bright elongated structures away from areas with strong photospheric magnetic fields. This suggests that the observed fast-propagating intensity disturbances are related to the magnetic canopy structures. The maximum distance traveled by the intensity disturbances is about 10″, and the widths are a few arcseconds, which are almost determined by a pixel size of 1.″03. The timescale of each intensity pulse is shorter than 30 s. One possible explanation for the fast-propagating intensity disturbances observed by CLASP is magnetohydrodynamic fast-mode waves.

SOHO Ultraviolet Coronagraph Spectrometer (UVCS) Mission Operations and Data Analysis

NASA Technical Reports Server (NTRS)

Kohl, John L.; Gurman, Joseph (Technical Monitor)

2003-01-01

The scientific goal of UVCS is to obtain detailed empirical descriptions of the extended solar corona as it evolves over the solar cycle and to use these descriptions to identify and understand the physical processes responsible for coronal heating, solar wind acceleration, coronal mass ejections (CMEs), and the phenomena that establish the plasma properties of the solar wind as measured by 'in situ' solar wind instruments. This report covers the period from 01 February 2002 to 15 February 2003. During that time, UVCS observations have consisted of three types: 1) standard synoptic observations comprising, primarily, the H I Ly alpha line profile and the O VI 103.2 and 103.7 nm intensity over a range of heights from 1.5 to about 3.0 solar radii and covering 360 degrees about the sun, 2) sit and stare watches for CMEs, and 3) special observations designed by the UVCS Lead Observer of the Week for a specific scientific purpose. The special observations are often coordinated with those of other space-based and ground-based instruments and they often are part of SOHO joint observation programs and campaigns. Lead observers have included UVCS Co-Investigators, scientists from the solar physics community and several graduate and undergraduate level students. UVCS has continued to achieve its purpose of using powerful spectroscopic diagnostic techniques to obtain a much more detailed description of coronal structures and dynamic phenomena than existed before the SOHO mission. The new descriptions of coronal mass ejections (CMEs) and coronal structures from UVCS have inspired a large number of theoretical studies aimed at identifying the physical processes responsible for CMEs and solar wind acceleration in coronal holes and streamers. UVCS has proven to be a very stable instrument. Stellar observations have demonstrated its stability. UVCS has required no flight software modifications and all mechanisms are operational. The UVCS O VI Channel with its redundant optical path for wavelengths near H I Ly alpha is capable of observing the entire UVCS wavelength range. Since December 1998, the O VI Channel has been used for all UVCS observations. Although the H I Ly alpha Channel and detector are still operational, increases in the dark count up to about 5 x 10(exp -4) counts/sec/pixel and an increase in high voltage current to within a factor of two of the maximum used in the laboratory before flight led to the decision to not use that detector at the present time. There is no significant decrease in the scientific capability of UVCS owing to the O VI channel redundant optical path. UVCS data, data analysis software, calibration files and the mission log are available from the SOHO archive and SAO. All UVCS data is now available to scientists and the general public via the SOHO Data Archive and SAO within three months of the observations. UVCS has resulted in 46 scientific papers in 2002. There were numerous presentations at scientific meetings. All requests for observation time by qualified outside users have been granted.

The VLT LBG redshift survey - VI. Mapping H I in the proximity of z ˜ 3 LBGs with X-Shooter

NASA Astrophysics Data System (ADS)

Bielby, R. M.; Shanks, T.; Crighton, N. H. M.; Bornancini, C. G.; Infante, L.; Lambas, D. G.; Minniti, D.; Morris, S. L.; Tummuangpak, P.

2017-10-01

We present an analysis of the spatial distribution and dynamics of neutral hydrogen gas around galaxies using new X-Shooter observations of z ˜ 2.5-4 quasars. Adding the X-Shooter data to our existing data set of high-resolution quasar spectroscopy, we use a total sample of 29 quasars alongside ˜1700 Lyman Break Galaxies (LBGs) in the redshift range 2 ≲ z ≲ 3.5. We measure the Lyα forest auto-correlation function, finding a clustering length of s0 = 0.081 ± 0.006 h-1 Mpc, and the cross-correlation function with LBGs, finding a cross-clustering length of s0 = 0.27 ± 0.14 h-1 Mpc and power-law slope γ = 1.1 ± 0.2. Our results highlight the weakly clustered nature of neutral hydrogren systems in the Lyα forest. Building on this, we make a first analysis of the dependence of the clustering on absorber strength, finding a clear preference for stronger Lyα forest absorption features to be more strongly clustered around the galaxy population, suggesting that they trace on average higher mass haloes. Using the projected and 2-D cross-correlation functions, we constrain the dynamics of Lyα forest clouds around z ˜ 3 galaxies. We find a significant detection of large-scale infall of neutral hydrogen, with a constraint on the Lyα forest infall parameter of βF = 1.02 ± 0.22.

Line Intensity Mapping during the Epoch of Reionization

NASA Astrophysics Data System (ADS)

Silva, Marta B.; Zaroubi, Saleem

2018-05-01

Characterizing the properties and the evolution of the first stars and galaxies is a challenging task for traditional galaxy surveys since they are sensitivity limited and can only detect the brightest light sources. Three-dimensional intensity mapping (IM) of transition lines can be a valuable alternative to study the high redshift Universe given that this technique avoids sensitivity limitation problems by measuring the overall emission of a line, with a low resolution, without resolving its sources. While 21cm line IM surveys probe neutral hydrogen gas and can, therefore, be used to probe the state of the IGM and the evolution of the ionization field during the Epoch of Reionization (EoR). IM surveys of other lines, such as CO, CII, Ly-alpha or H-alpha, can be used to probe the galaxies which emitted most of the ionizing radiation responsible for the EoR. These lines will trace the different ISM gas phases, the excitation state of this gas, its metallicity, etc. This study addresses IM of multiple transition lines and how it can be used to probe the EoR and to constrain the redshift evolution of galaxy properties.

A CD2-green fluorescence protein-transgenic mouse reveals very late antigen-4-dependent CD8+ lymphocyte rolling in inflamed venules.

PubMed

Singbartl, K; Thatte, J; Smith, M L; Wethmar, K; Day, K; Ley, K

2001-06-15

Intravital microscopy allows detailed analysis of leukocyte trafficking in vivo, but fails to identify the nature of leukocytes investigated. Here, we describe the development of a CD2-enhanced green fluorescence protein (EGFP)-transgenic mouse to characterize lymphocyte trafficking during inflammation in vivo. A CD2-EGFP plasmid construct including the CD2 promoter, the EGFP transgene, and the CD2 locus control region was injected into B6CBA/F1 pronuclei. EGFP+ offspring were backcrossed into C57BL/6 mice for six generations. Flow cytometry demonstrated that all peripheral blood EGFP+ cells were positive for CD2 and negative for the granulocyte Ag Ly 6-G (GR-1). EGFP(high) cells stained positive for CD2, CD3, CD8, TCR beta-chain, and NK1.1 but did not express the B cell and monocyte markers CD45RA, CD19, and CD11b. In vitro stimulation assays revealed no difference in lymphocyte proliferation and IL-2 secretion between EGFP+ and EGFP- mice. Intravital microscopy of untreated or TNF-alpha-treated cremaster muscle venules showed EGFP+ cells in vivo, but these cells did not roll or adhere to the vessel wall. In cremaster muscle venules treated with both TNF-alpha and IFN-gamma, EGFP(high) cells rolled, adhered, and transmigrated at a rolling velocity slightly higher (11 microm/s) than that of neutrophils (10 microm/s). Blocking alpha4 integrin with a mAb increased rolling velocity to 24 microm/s. These findings show that CD8+ T cells roll in TNF-alpha/IFN-gamma-pretreated vessels in vivo via an alpha4 integrin-dependent pathway.

LyP-1-conjugated Fe3O4 nanoparticles suppress tumor growth by magnetic induction hyperthermia.

PubMed

Teo, Peishan; Wang, Xiaowen; Zhang, Jieying; Zhang, Han; Yang, Xin; Huang, Yun; Tang, Jintian

2018-02-01

To find a promising drug carrier to suppress tumor using magnetic induction hyperthermia (MIH) and targeted therapy, two superparamagnetic iron oxide nanoparticles (SPIONs) coated with polyethylene glycol (PEG) and LyP-1, respectively, were prepared and compared. The particle size ranges of PEG-SPIONs and LyP-1-SPIONs were 10-15 nm, and 15-20 nm, respectively. In FTIR spectra, PEG-SPIONs and LyP-1-SPIONs had strong peaks between 575 and 1630 cm -1 . Specifically, the PEG-SPIONs mainly has peaks in 581 and 1630 cm -1 . The LyP-1-SPIONs mainly had peaks in 575, 1050 and 1625 cm -1 . The contents of Fe 3 O 4 in the PEG-SPIONs and LyP-1-SPIONs were about 94.24 and 89.26%, respectively. The iron contents in the MCF-7 and CT-26 cells were 33.1 ± 1.8 and 27.9 ± 0.95 pg, respectively, after co-incubation with LyP-1-SPIONs for 8 h. The LyP-1-SPIONs accumulated in the nucleus of MCF-7 cells while PEG-SPIONs in cytoplasma. In vitro, after 30 days we can found the tumor almost stopped to grow in Group LyP-1-SPIONs. LyP-1-SPIONs are promising in treating cancer as they accumulated in the nucleus of MCF-7 cells which expressed p32 and almost stopped tumor growth by combined MIH and targeted therapy.

A Faint Flux-limited Ly α Emitter Sample at z ∼ 0.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wold, Isak G. B.; Finkelstein, Steven L.; Barger, Amy J.

2017-10-20

We present a flux-limited sample of z ∼ 0.3 Ly α emitters (LAEs) from Galaxy Evolution Explorer ( GALEX ) grism spectroscopic data. The published GALEX z ∼ 0.3 LAE sample is pre-selected from continuum-bright objects and thus is biased against high equivalent width (EW) LAEs. We remove this continuum pre-selection and compute the EW distribution and the luminosity function of the Ly α emission line directly from our sample. We examine the evolution of these quantities from z ∼ 0.3 to 2.2 and find that the EW distribution shows little evidence for evolution over this redshift range. As shownmore » by previous studies, the Ly α luminosity density from star-forming (SF) galaxies declines rapidly with declining redshift. However, we find that the decline in Ly α luminosity density from z = 2.2 to z = 0.3 may simply mirror the decline seen in the H α luminosity density from z = 2.2 to z = 0.4, implying little change in the volumetric Ly α escape fraction. Finally, we show that the observed Ly α luminosity density from AGNs is comparable to the observed Ly α luminosity density from SF galaxies at z = 0.3. We suggest that this significant contribution from AGNs to the total observed Ly α luminosity density persists out to z ∼ 2.2.« less

Detection of emission lines from z ˜ 3 DLAs towards the QSO J2358+0149

NASA Astrophysics Data System (ADS)

Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari

2016-07-01

Using VLT/X-shooter, we searched for emission line galaxies associated with four damped Lyman α systems (DLAs) and one sub-DLA at 2.73 ≤z ≤3.25 towards QSO J2358+0149. We detect [O III] emission from a `low-cool' DLA at zabs = 2.9791 (having log N(H I) = 21.69 ± 0.10, [Zn/H] = -1.83 ± 0.18) at an impact parameter of, ρ ˜ 12 kpc. The associated galaxy is compact with a dynamical mass of (1-6) × 109 M⊙, very high excitation ([O III]/[O II] and [O III]/[Hβ] both greater than 10), 12+[O/H]≤8.5 and moderate star formation rate (SFR ≤2 M⊙ yr-1). Such properties are typically seen in the low-z extreme blue compact dwarf galaxies. The kinematics of the gas is inconsistent with that of an extended disc and the gas is part of either a large scale wind or cold accretion. We detect Lyα emission from the zabs = 3.2477 DLA [having log N(H I) = 21.12 ± 0.10 and [Zn/H] = -0.97 ± 0.13]. The Lyα emission is redshifted with respect to the metal absorption lines by 320 km s-1, consistent with the location of the red hump expected in radiative transport models. We derive SFR ˜0.2-1.7 M⊙ yr-1 and Lyα escape fraction of ≥10 per cent. No other emission line is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA emission is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα emission is being induced by the QSO itself. QSO-induced Lyα fluorescence is possible if the DLA is within a physical separation of 340 kpc to the QSO. Detection of stellar continuum light and/or the oxygen emission lines would disfavour this possibility. We do not detect any emission line from the remaining three systems.

Identities of P2 and P3 Residues of H-2Kb-Bound Peptides Determine Mouse Ly49C Recognition

PubMed Central

Marquez, Elsa A.; Kane, Kevin P.

2015-01-01

Ly49 receptors can be peptide selective in their recognition of MHC-I-peptide complexes, affording them a level of discrimination beyond detecting the presence or absence of specific MHC-I allele products. Despite this ability, little is understood regarding the properties that enable some peptides, when bound to MHC-I molecules, to support Ly49 recognition, but not others. Using RMA-S target cells expressing MHC-I molecules loaded with individual peptides and effector cells expressing the ectodomain of the inhibitory Ly49C receptor, we found that two adjacent amino acid residues, P2 and P3, both buried in the peptide binding groove of H-2Kb, determine mouse Ly49C specificity. If both are aliphatic residues, this is supportive. Whereas, small amino acids at P2 and aromatic amino acids at the P3 auxiliary anchor residue are detrimental to Ly49C recognition. These results resemble those with a rat Ly49 where the identity of a peptide anchor residue determines recognition, suggesting that dependence on specific peptide residues buried in the MHC-I peptide-binding groove may be fundamental to Ly49 peptide selectivity and recognition. PMID:26147851

Deep learning of quasar spectra to discover and characterize damped Lyα systems

NASA Astrophysics Data System (ADS)

Parks, David; Prochaska, J. Xavier; Dong, Shawfeng; Cai, Zheng

2018-05-01

We have designed, developed, and applied a convolutional neural network (CNN) architecture using multi-task learning to search for and characterize strong H I Lyα absorption in quasar spectra. Without any explicit modelling of the quasar continuum or application of the predicted line profile for Lyα from quantum mechanics, our algorithm predicts the presence of strong H I absorption and estimates the corresponding redshift zabs and H I column density N_{H I}, with emphasis on damped Lyα systems (DLAs, absorbers with N_{H I}≥ 2 × 10^{20} cm^{-2}). We tuned the CNN model using a custom training set of DLAs injected into DLA-free quasar spectra from the Sloan Digital Sky Survey (SDSS), data release 5 (DR5). Testing on a held-back validation set demonstrates a high incidence of DLAs recovered by the algorithm (97.4 per cent as DLAs and 99 per cent as an H I absorber with N_{H I}> 10^{19.5} cm^{-2}) and excellent estimates for zabs and N_{H I}. Similar results are obtained against a human-generated survey of the SDSS DR5 data set. The algorithm yields a low incidence of false positives and negatives but is challenged by overlapping DLAs and/or very high N_{H I} systems. We have applied this CNN model to the quasar spectra of SDSS DR7 and the Baryon Oscillation Spectroscopic Survey (data release 12) and provide catalogues of 4913 and 50 969 DLAs, respectively (including 1659 and 9230 high-confidence DLAs that were previously unpublished). This work validates the application of deep learning techniques to astronomical spectra for both classification and quantitative measurements.

A Lyα blob and zabs ≈ zem damped Lyα absorber in the dark matter halo of the binary quasar Q 0151+048

NASA Astrophysics Data System (ADS)

Zafar, T.; Møller, P.; Ledoux, C.; Fynbo, J. P. U.; Nilsson, K. K.; Christensen, L.; D'Odorico, S.; Milvang-Jensen, B.; Michałowski, M. J.; Ferreira, D. D. M.

2011-08-01

Context. Q 0151+048 is a physical quasar (QSO) pair at z ~ 1.929 with a separation of 3.3 arcsec on the sky. In the spectrum of the brighter member of this pair, Q 0151+048A, a damped Lyα absorber (DLA) is observed at a higher redshift. We have previously detected the host galaxies of both QSOs, as well as a Lyα blob whose emission surrounding Q 0151+048A extends over 5 × 3.3 arcsec. Aims: We seek to constrain the geometry of the system and understand the possible relations between the DLA, the Lyα blob, and the two QSOs. We also aim at characterizing the former two objects in more detail. Methods: To study the nature of the Lyα blob, we performed low-resolution, long-slit spectroscopy with the slit aligned with the extended emission. We also observed the whole system using the medium-resolution VLT/X-shooter spectrograph and the slit aligned with the two QSOs. The systemic redshift of both QSOs was determined from rest-frame optical emission lines redshifted into the NIR. We employed line-profile fitting technique, to measure metallicities and the velocity width of low-ionization metal absorption lines associated to the DLA and photo-ionization modeling to characterize the DLA further. Results: We measure systemic redshifts of zem(A) = 1.92924 ± 0.00036 and zem(B) = 1.92863 ± 0.00042 from the H β and H α emission lines, respectively. In other words, the two QSOs have identical redshifts within 2σ. From the width of Balmer emission lines and the strength of the rest-frame optical continuum, we estimate the masses of the black holes of the two QSOs to be 109.33 M⊙ and 108.38 M⊙ for Q 0151+048A and Q 0151+048B, respectively. We then use the correlation between black hole mass and dark matter halo mass to infer the mass of the dark matter halos hosting the two QSOs: 1013.74 M⊙ and 1013.13 M⊙ for Q 0151+048A and Q 0151+048B, respectively. We observe a velocity gradient along the major axis of the Lyα blob consistent with the rotation curve of a large disk galaxy, but it may also be caused by gas inflow or outflow. We detect residual continuum in the DLA trough, which we interpret as emission from the host galaxy of Q 0151+048A. The derived H0 column density of the DLA is log NH0 = 20.34 ± 0.02 cm-2. Metal column densities are also determined for a number of low-ionization species resulting in an overall metallicity of 0.01 Z⊙. We detect C ii ∗ , which allows us to make a physical model of the DLA cloud. Conclusions: From the systemic redshifts of the QSOs, we conclude that the Lyα blob is associated with Q 0151+048A rather than with the DLA. The DLA must be located in front of both the Lyα blob and Q 0151+048A at a distance greater than 30 kpc and has a velocity relative to the blob of 640 ± 70 km s-1. The two quasars accrete at normal Eddington ratios. The DM halo of this double quasar will grow to the mass of our local supercluster at z = 0. We point out that those objects therefore form an ideal laboratory to study the physical interactions in a z = 2 precursor of our local supercluster. Based on observations done with i) European Southern Observatory (ESO) utilizing 8.2m Very Large Telescope (VLT) X-shooter spectrograph on Cerro Paranal in the Atacama Desert, northern Chile. ii) 2.56 m Nordic Optical Telescope (NOT), a scientific association between Denmark, Finland, Iceland, Norway and Sweden, operated at Observatorio del Roque de Los Muchachos on the island of La Palma, Spain.

Large-scale clustering of Lymanα emission intensity from SDSS/BOSS

DOE PAGES

Croft, Rupert A. C.; Miralda-Escudé, Jordi; Zheng, Zheng; ...

2016-01-27

Here we present a tentative detection of the large-scale structure of Ly α emission in the Universe at redshifts z = 2–3.5 by measuring the cross-correlation of Ly α surface brightness with quasars in Sloan Digital Sky Survey/Baryon Oscillation Spectroscopic Survey. We use a million spectra targeting luminous red galaxies at z < 0.8, after subtracting a best-fitting model galaxy spectrum from each one, as an estimate of the high-redshift Ly α surface brightness. The quasar–Ly α emission cross-correlation is detected on scales 1 ~ 15h ₋1 Mpc, with shape consistent with a ΛCDM model with Ω m =0.30± 0.10more » 0.07. The predicted amplitude of this cross- correlation is proportional to the product of the mean Lyα surface brightness, {μ α}, the amplitude of mass density fluctuations, and the quasar and Lyα emission bias factors. Using published cosmological observations to constrain the amplitude of mass fluctuations and the quasar bias factor, we infer the value of the product {μ α} (b α /3) = (3.9±0.9)×10 ₋21 erg s ₋1 cm ₋2 °A ₋1 arcsec ₋2, where b α is the Lyα emission linear bias factor. If the dominant sources of Lyα emission we measure are star forming galaxies, we infer a total mean star formation rate density of ρSFR = (0.28 ± 0.07)(3/b α ) yr ₋1 Mpc ₋3 at z = 2 ₋ 3.5. For b α = 3, this value is a factor of 21 ₋ 35 above previous estimates relying on individually detected Lyα emitters, although it is consistent with the total star-formation density derived from dust-corrected, continuum UV surveys. Our observations therefore imply that 97% of the Lyα emission in the Universe at these redshifts is undetected in previous surveys of Lyα emitters. Our detected Lyα emission is also much greater, by at least an order of magnitude, than that measured from stacking analyses of faint halos surrounding previously detected Lyα emitters, but we speculate that it arises from similar low surface brightness Lyα halos surrounding all luminous star-forming galaxies. We also detect a redshift space anisotropy of the quasar-Lyα emission cross-correlation, finding evidence at the 3.0σ level that it is radially elongated, contrary to the prediction for linear gravitational evolution, but consistent with distortions caused by radiative-transfer effects, as predicted by Zheng et al. (2011). Lastly, our measurements represent the first application of the intensity mapping technique to optical observations.« less

Accelerated evolution of the Lyα luminosity function at z ≳ 7 revealed by the Subaru ultra-deep survey for Lyα emitters at z = 7.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konno, Akira; Ouchi, Masami; Ono, Yoshiaki

2014-12-10

We present the ultra-deep Subaru narrowband imaging survey for Lyα emitters (LAEs) at z = 7.3 in the Subaru/XMM-Newton Deep Survey (SXDS) and Cosmic Evolution Survey (COSMOS) fields (∼0.5 deg{sup 2}) with a total integration time of 106 hr. Exploiting our new sharp bandwidth filter, NB101, installed on the Suprime-Cam, we have reached L(Lyα) = 2.4 × 10{sup 42} erg s{sup –1} (5σ) for z = 7.3 LAEs, about four times deeper than previous Subaru z ≳ 7 studies, which allows us to reliably investigate the evolution of the Lyα luminosity function (LF) for the first time down to themore » luminosity limit same as those of Subaru z = 3.1-6.6 LAE samples. Surprisingly, we only find three and four LAEs in the SXDS and COSMOS fields, respectively, while one expects a total of ∼65 LAEs by our survey in the case of no Lyα LF evolution from z = 6.6 to 7.3. We identify a decrease of the Lyα LF from z = 6.6 to 7.3 at the >90% confidence level from our z = 7.3 Lyα LF with the best-fit Schechter parameters of L{sub Lyα}{sup ∗}=2.7{sub −1.2}{sup +8.0}×10{sup 42} erg s{sup −1} and ϕ{sup ∗}=3.7{sub −3.3}{sup +17.6}×10{sup −4} Mpc{sup −3} for a fixed α = –1.5. Moreover, the evolution of the Lyα LF is clearly accelerated at z > 6.6 beyond the measurement uncertainties including cosmic variance. Because no such accelerated evolution of the UV-continuum LF or the cosmic star formation rate (SFR) is found at z ∼ 7, but suggested only at z > 8, this accelerated Lyα LF evolution is explained by physical mechanisms different from a pure SFR decrease but related to the Lyα production and escape in the process of cosmic reionization. Because a simple accelerating increase of intergalactic medium neutral hydrogen absorbing Lyα cannot be reconciled with Thomson scattering of optical depth measurements from WMAP and Planck, our findings may support new physical pictures suggested by recent theoretical studies, such as the existence of HI clumpy clouds within cosmic ionized bubbles that are selectively absorbing Lyα and the large ionizing photon escape fraction of galaxies causing weak Lyα emission.« less

CCL2, but not its receptor, is essential to restrict immune privileged central nervous system-invasion of Japanese encephalitis virus via regulating accumulation of CD11b(+) Ly-6C(hi) monocytes.

PubMed

Kim, Jin Hyoung; Patil, Ajit Mahadev; Choi, Jin Young; Kim, Seong Bum; Uyangaa, Erdenebileg; Hossain, Ferdaus Mohd Altaf; Park, Sang-Youel; Lee, John Hwa; Kim, Koanhoi; Eo, Seong Kug

2016-10-01

Japanese encephalitis virus (JEV) is a re-emerging zoonotic flavivirus that poses an increasing threat to global health and welfare due to rapid changes in climate and demography. Although the CCR2-CCL2 axis plays an important role in trafficking CD11b(+) Ly-6C(hi) monocytes to regulate immunopathological diseases, little is known about their role in monocyte trafficking during viral encephalitis caused by JEV infection. Here, we explored the role of CCR2 and its ligand CCL2 in JE caused by JEV infection using CCR2- and CCL2-ablated murine models. Somewhat surprisingly, the ablation of CCR2 and CCL2 resulted in starkly contrasting susceptibility to JE. CCR2 ablation induced enhanced resistance to JE, whereas CCL2 ablation highly increased susceptibility to JE. This contrasting regulation of JE progression by CCR2 and CCL2 was coupled to central nervous system (CNS) infiltration of Ly-6C(hi) monocytes and Ly-6G(hi) granulocytes. There was also enhanced expression of CC and CXC chemokines in the CNS of CCL2-ablated mice, which appeared to induce CNS infiltration of these cell populations. However, our data revealed that contrasting regulation of JE in CCR2- and CCL2-ablated mice was unlikely to be mediated by innate natural killer and adaptive T-cell responses. Furthermore, CCL2 produced by haematopoietic stem cell-derived leucocytes played a dominant role in CNS accumulation of Ly-6C(hi) monocytes in infected bone marrow chimeric models, thereby exacerbating JE progression. Collectively, our data indicate that CCL2 plays an essential role in conferring protection against JE caused by JEV infection. In addition, blockage of CCR2, but not CCL2, will aid in the development of strategies for prophylactics and therapeutics of JE. © 2016 John Wiley & Sons Ltd.

Limits on the LyC signal from z ~ 3 sources with secure redshift and HST coverage in the E-CDFS field

NASA Astrophysics Data System (ADS)

Guaita, L.; Pentericci, L.; Grazian, A.; Vanzella, E.; Nonino, M.; Giavalisco, M.; Zamorani, G.; Bongiorno, A.; Cassata, P.; Castellano, M.; Garilli, B.; Gawiser, E.; Le Brun, V.; Le Fèvre, O.; Lemaux, B. C.; Maccagni, D.; Merlin, E.; Santini, P.; Tasca, L. A. M.; Thomas, R.; Zucca, E.; De Barros, S.; Hathi, N. P.; Amorin, R.; Bardelli, S.; Fontana, A.

2016-03-01

Context. Determining the strength of the Lyman continuum (LyC) and the fraction of LyC escape have implications for the properties of the emitting sources at any redshift, but also for the re-ionization of the Universe at z > 6. Aims: We aim to measure the LyC signal from a sample of sources in the Chandra deep field south. We collect star-forming galaxies (SFGs) and active galactic nuclei (AGN) with accurate spectroscopic redshifts, for which Hubble Space Telescope (HST) coverage and multi-wavelength photometry are available. Methods: We selected a sample of about 200 sources at z ~ 3. Taking advantage of HST resolution, we applied a careful cleaning procedure and rejected sources showing nearby clumps with different colours, which could be lower-z interlopers. Our clean sample consisted of 86 SFGs (including 19 narrow-band selected Lyα emitters) and 8 AGN (including 6 detected in X-rays). We measured the LyC flux from aperture photometry in four narrow-band filters covering wavelengths below a 912 Å rest frame (3.11 < z < 3.53). We estimated the ratio between ionizing (LyC flux) and 1400 Å non-ionizing emissions for AGN and galaxies. Results: By running population synthesis models, we assume an average intrinsic Lν(1400 Å)/Lν(900 Å) ratio of 5 as the representative value for our sample. With this value and an average treatment of the lines of sight of the inter-galactic medium, we estimate the LyC escape fraction relative to the intrinsic value (fescrel(LyC)). We do not directly detect ionizing radiation from any individual SFG, but we are able to set a 1(2)σ upper limit of fescrel(LyC) < 12(24)%. This result is consistent with other non-detections published in the literature. No meaningful limits can be calculated for the sub-sample of Lyα emitters. We obtain one significant direct detection for an AGN at z = 3.46, with fescrel(LyC) = (72 ± 18)%. Conclusions: Our upper limit on fescrel(LyC) implies that the SFGs studied here do not present either the physical properties or the geometric conditions suitable for efficient LyC-photon escape. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Programs 170.A-0788, 074.A-0709, 171.A-3045, 275.A-5060, and 185.A-0791.

Time variations of solar UV irradiance as measured by the SOLSTICE (UARS) instrument

NASA Technical Reports Server (NTRS)

London, Julius; Rottman, Gary J.; Woods, Thomas N.; Wu, Fie

1993-01-01

An analysis is presented of solar ultraviolet irradiance measurements made by the SOLSTICE spectrometers on the Upper Atmosphere Research Satellite (UARS). Reported observations cover the wavelength interval 119-420 nm, and the analysis discussed here is for the time period 26 Nov 1991 to 31 Dec 1992, during which time solar activity decreased in intensity. At the time of peak activity, the average 27-day variation had a relative amplitude of about 8 percent at Ly-alpha, tailing off to about 0.6 percent at 260 nm. It is shown that over the spectral interval 119-260 nm, the relative 27-day harmonic was about a factor of two larger during the strongly disturbed as compared with the moderately disturbed period.

Spectrophotometry near the atmospheric cutoff of the strongest Bowen resonance fluorescence lines of O III in two planetary nebulae

NASA Technical Reports Server (NTRS)

O'Dell, C. R.; Opal, Chet B.

1989-01-01

Spectrophotometric results are presented for the stronger, well-resolved Bowen O III resonance fluorescence emission lines in the planetary nebulae 7027 and NGC 7662 down to and including the intrinsically strong line at 3133 A. These data are combined with results from the IUE atlas of spectra and similar results for the longer wavelength lines by Likkel and Aller (1986) to give the first full coverage of the Bowen lines. Good agreement is found with fluorescence theory for the primary cascade lines, except for the Likkel and Aller results. The efficiency of conversion of the exciting He II Ly-alpha into O III lines is determined, and values comparable to other planetary nebulae are found.

The coolest DA white dwarfs detected at soft X-ray wavelengths

NASA Technical Reports Server (NTRS)

Kidder, K. M.; Holberg, J. B.; Barstow, M. A.; Tweedy, R. W.; Wesemael, F.

1992-01-01

New soft X-ray/EUV photometric observations of the DA white dwarfs KPD 0631 + 1043 = WD 0631 + 107 and PG 1113 + 413 = WD 1113 + 413 are analyzed. Previously reported soft X-ray detections of three other DAs and the failure to detect a fourth DA in deep Exosat observations are investigated. New ground-based spectra are presented for all of the objects, with IUE Ly-alpha spectra for some. These data are used to constrain the effective temperatures and surface gravities. The improved estimates of these parameters are employed to refer a photospheric He abundance for the hotter objects and to elucidate an effective observational low-temperature threshold for the detection of pure hydrogen DA white dwarfs at soft X-ray wavelengths.

More than Solfège and Hand Signs: Philosophy, Tools, and Lesson Planning in the Authentic Kodály Classroom

ERIC Educational Resources Information Center

Bowyer, James

2015-01-01

Four components of the Kodály concept are delineated here: philosophy, objectives, essential tools, and lesson planning process. After outlining the tenets of the Kodály philosophy and objectives, the article presents the Kodály concept's essential tools, including singing, movable "do" solfège, rhythm syllables, hand signs, singing on…

Spectroscopic properties of luminous Ly α emitters at z ≈ 6-7 and comparison to the Lyman-break population

NASA Astrophysics Data System (ADS)

Matthee, Jorryt; Sobral, David; Darvish, Behnam; Santos, Sérgio; Mobasher, Bahram; Paulino-Afonso, Ana; Röttgering, Huub; Alegre, Lara

2017-11-01

We present spectroscopic follow-up of candidate luminous Ly α emitters (LAEs) at z = 5.7-6.6 in the SA22 field with VLT/X-SHOOTER. We confirm two new luminous LAEs at z = 5.676 (SR6) and z = 6.532 (VR7), and also present HST follow-up of both sources. These sources have luminosities LLy α ≈ 3 × 1043 erg s-1, very high rest-frame equivalent widths of EW0 ≳ 200 Å and narrow Ly α lines (200-340 km s-1). VR7 is the most UV-luminous LAE at z > 6.5, with M1500 = -22.5, even brighter in the UV than CR7. Besides Ly α, we do not detect any other rest-frame UV lines in the spectra of SR6 and VR7, and argue that rest-frame UV lines are easier to observe in bright galaxies with low Ly α equivalent widths. We confirm that Ly α line widths increase with Ly α luminosity at z = 5.7, while there are indications that Ly α lines of faint LAEs become broader at z = 6.6, potentially due to reionization. We find a large spread of up to 3 dex in UV luminosity for >L⋆ LAEs, but find that the Ly α luminosity of the brightest LAEs is strongly related to UV luminosity at z = 6.6. Under basic assumptions, we find that several LAEs at z ≈ 6-7 have Ly α escape fractions ≳ 100 per cent, indicating bursty star formation histories, alternative Ly α production mechanisms, or dust attenuating Ly α emission differently than UV emission. Finally, we present a method to compute ξion, the production efficiency of ionizing photons, and find that LAEs at z ≈ 6-7 have high values of log10(ξion/Hz erg-1) ≈ 25.51 ± 0.09 that may alleviate the need for high Lyman-Continuum escape fractions required for reionization.

SILVERRUSH. IV. Lyα luminosity functions at z = 5.7 and 6.6 studied with ˜1300 Lyα emitters on the 14-21 deg2 sky

NASA Astrophysics Data System (ADS)

Konno, Akira; Ouchi, Masami; Shibuya, Takatoshi; Ono, Yoshiaki; Shimasaku, Kazuhiro; Taniguchi, Yoshiaki; Nagao, Tohru; Kobayashi, Masakazu A. R.; Kajisawa, Masaru; Kashikawa, Nobunari; Inoue, Akio K.; Oguri, Masamune; Furusawa, Hisanori; Goto, Tomotsugu; Harikane, Yuichi; Higuchi, Ryo; Komiyama, Yutaka; Kusakabe, Haruka; Miyazaki, Satoshi; Nakajima, Kimihiko; Wang, Shiang-Yu

2018-01-01

We present the Lyα luminosity functions (LFs) at z = 5.7 and 6.6 derived from a new large sample of 1266 Lyα emitters (LAEs) identified in total areas of 14 and 21 deg2, respectively, based on the early narrowband data of the Subaru/Hyper Suprime-Cam survey. Together with careful Monte Carlo simulations that account for the incompleteness of the LAE selection and the flux estimate systematics in the narrowband imaging, we have determined the Lyα LFs with unprecedentedly small statistical and systematic uncertainties in a wide Lyα luminosity range of 1042.8-43.8 erg s-1. We obtain best-fit Schechter parameters of L^{*}_{Lyα } = 1.6^{+2.2}_{-0.6} (1.7^{+0.3}_{-0.7}) × 10^{43}ergs^{-1}, φ ^{*}_{Lyα } = 0.85^{+1.87}_{-0.77} (0.47^{+1.44}_{-0.44}) × 10^{-4}Mpc^{-3}, and α = -2.6^{+0.6}_{-0.4} (-2.5^{+0.5}_{-0.5}) at z = 5.7 (6.6). We confirm that our best-estimate Lyα LFs are consistent with the majority of the previous studies, but find that our Lyα LFs do not agree with the high number densities of LAEs recently claimed by Matthee/Santos et al.'s studies that may overcorrect the incompleteness and the flux systematics. Our Lyα LFs at z = 5.7 and 6.6 show an indication that the faint-end slope is very steep (α ≃ -2.5), although it is also possible that the bright-end LF results are enhanced by systematic effects such as the contribution from AGNs, blended merging galaxies, and/or large ionized bubbles around bright LAEs. Comparing our Lyα LF measurements with four independent reionization models, we estimate the neutral hydrogen fraction of the intergalactic medium to be x_{H I} = 0.3 ± 0.2 at z = 6.6, which is consistent with the small Thomson scattering optical depth obtained by Planck 2016.

J1154+2443: a low-redshift compact star-forming galaxy with a 46 per cent leakage of Lyman continuum photons

NASA Astrophysics Data System (ADS)

Izotov, Y. I.; Schaerer, D.; Worseck, G.; Guseva, N. G.; Thuan, T. X.; Verhamme, A.; Orlitová, I.; Fricke, K. J.

2018-03-01

We report the detection of the Lyman continuum (LyC) radiation of the compact star-forming galaxy (SFG) J1154+2443 observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope. This galaxy, at a redshift of z = 0.3690, is characterized by a high emission-line flux ratio O32 = [O III] λ5007/[O II] λ3727 = 11.5. The escape fraction of the LyC radiation fesc(LyC) in this galaxy is 46 per cent, the highest value found so far in low-redshift SFGs and one of the highest values found in galaxies at any redshift. The narrow double-peaked Ly α emission line is detected in the spectrum of J1154+2443 with a separation between the peaks Vsep of 199 km s-1, one of the lowest known for Ly α-emitting galaxies, implying a high fesc(Ly α). Comparing the extinction-corrected Ly α/H β flux ratio with the case B value, we find fesc(Ly α) = 98 per cent. Our observations, combined with previous detections in the literature, reveal an increase of O32 with increasing fesc(LyC). We also find a tight anticorrelation between fesc(LyC) and Vsep. The surface brightness profile derived from the COS acquisition image reveals a bright star-forming region in the centre and an exponential disc in the outskirts with a disc scale length α = 1.09 kpc. J1154+2443, compared to other known low-redshift LyC leakers, is characterized by the lowest metallicity, 12+log O/H = 7.65 ± 0.01, the lowest stellar mass M⋆ = 108.20 M⊙, a similar star formation rate SFR = 18.9 M⊙ yr-1, and a high specific SFR of 1.2 × 10-7 yr-1.

Better Glycemic Control and Weight Loss With the Novel Long-Acting Basal Insulin LY2605541 Compared With Insulin Glargine in Type 1 Diabetes

PubMed Central

Rosenstock, Julio; Bergenstal, Richard M.; Blevins, Thomas C.; Morrow, Linda A.; Prince, Melvin J.; Qu, Yongming; Sinha, Vikram P.; Howey, Daniel C.; Jacober, Scott J.

2013-01-01

OBJECTIVE To compare effects of LY2605541 versus insulin glargine on daily mean blood glucose as part of a basal-bolus regimen for type 1 diabetes. RESEARCH DESIGN AND METHODS In this randomized, Phase 2, open-label, 2 × 2 crossover study, 137 patients received once-daily basal insulin (LY2605541 or glargine) plus mealtime insulin for 8 weeks, followed by crossover treatment for 8 weeks. Daily mean blood glucose was obtained from 8-point self-monitored blood glucose profiles. The noninferiority margin was 10.8 mg/dL. RESULTS LY2605541 met noninferiority and superiority criteria compared with insulin glargine in daily mean blood glucose (144.2 vs. 151.7 mg/dL, least squares mean difference = −9.9 mg/dL [90% CI −14.6 to −5.2], P < 0.001). Fasting blood glucose variability and A1C were reduced with LY2605541 compared with insulin glargine (both P < 0.001). Mealtime insulin dose decreased with LY2605541 and increased with insulin glargine. Mean weight decreased 1.2 kg with LY2605541 and increased 0.7 kg with insulin glargine (P < 0.001). The total hypoglycemia rate was higher for LY2605541 (P = 0.04) and the nocturnal hypoglycemia rate was lower (P = 0.01), compared with insulin glargine. Adverse events (including severe hypoglycemia) were similar, although more gastrointestinal-related events occurred with LY2605541 (15% vs. 4%, P < 0.001). Mean changes (all within normal range) were higher for alanine aminotransferase, aspartate aminotransferase, triglycerides, and LDL-cholesterol and lower for HDL-cholesterol with LY2605541 compared with insulin glargine (all P < 0.02). CONCLUSIONS In type 1 diabetes, compared with insulin glargine, LY2605541, a novel, long-acting basal insulin, demonstrated greater improvements in glycemic control, increased total hypoglycemia, and reduced nocturnal hypoglycemia, as well as reduced weight and lowered mealtime insulin doses. PMID:23193209

A phase I dose-escalation study of LY2875358, a bivalent MET antibody, given as monotherapy or in combination with erlotinib or gefitinib in Japanese patients with advanced malignancies.

PubMed

Yoh, Kiyotaka; Doi, Toshihiko; Ohmatsu, Hironobu; Kojima, Takashi; Takahashi, Hideaki; Zenke, Yoshitaka; Wacheck, Volker; Enatsu, Sotaro; Nakamura, Takashi; Turner, Kellie; Uenaka, Kazunori

2016-10-01

Background MET is a tyrosine kinase receptor involved in the regulation of cell proliferation and migration. Reported here are the phase I dose-escalation results for LY2875358, a monoclonal antibody against MET, in Japanese patients with advanced malignancies. Methods The study comprised a 3 + 3 dose-escalation part for LY2875358 monotherapy in patients with advanced malignancies (Part A) followed by an assessment of LY2875358 in combination with erlotinib or gefitinib in patients with non-small cell lung cancer (Part B). LY2875358 was administered once every 2 weeks. The primary objective was to evaluate the safety and tolerability of LY2875358; secondary objectives included evaluation of pharmacokinetics, pharmacodynamics, and antitumor activity. Results Eleven patients received LY2875358 monotherapy at 3 dose levels (700 mg, N = 3; 1400 mg, N = 3; 2000 mg, N = 5) and 6 patients received LY2875358 2000 mg in combination with erlotinib (N = 3) or gefitinib (N = 3). No dose-limiting toxicities or serious adverse events related to LY2875358 were observed. The most frequently reported drug-related adverse events were hypoalbuminemia (2 patients) in Part A and dermatitis acneiform (4 patients) in Part B. LY2875358 area under the curve (AUC) and maximum concentration (Cmax) increased with dose over the dose range of 700 mg to 2000 mg. A best response of stable disease was achieved by 2/11 patients in Part A and 4/6 patients in Part B (disease control rate: 35 %). Conclusions LY2875358 at doses up to 2000 mg demonstrated a favorable safety and tolerability profile as monotherapy or in combination with erlotinib or gefitinib in Japanese patients with advanced malignancies.

Lyα vs. fundamental properties of galaxies

NASA Astrophysics Data System (ADS)

Wofford, Aida; Leitherer, Claus; Salzer, John; COS Science Team

2013-03-01

We obtained HST COS Lyα spectroscopy for 20 galaxies that were Hα-selected from the Kitt Peak International Spectroscopic Survey data release. We cover redshifts of z=0.02-0.06 and a broad range in metallicity, reddening, and luminosity. We investigate correlations between the properties of the Lyα-lines and fundamental properties of the galaxies. Our seven emitters have: equivalent widths in the range EW(Lyα)=1-12 Å, i.e., below the completeness limits of higher redshift studies; extinction corrected Lyα/Hα ratios of at most 12-15% of the case B recombination theory value; and O I λ1302 ISM absorptions blueshifted to = - 117±40 km/s, which are consistent with H I gas outflows. Six emitters have P-Cygni-like Lyα profiles with peaks redshifted to =172±25 km/s, and one of our face-on spiral galaxies has two Lyα peaks separated by 370 km/s. The latter peaks are such that the blueshifted peak is twice as strong as the redshifted peak. The rest of the galaxies show Lyα absorption troughs centered at =19 km/s and O I λ1302 absorptions centered at = - 34±25 km/s, which is consistent with static or low velocity H I gas. Our two most metal poor and least reddened galaxies, which have large Hα equivalent widths are absorbers. The spiral galaxies in our sample have Lyα in single emission, double emission, or absorption. There appears to be a correlation between the Hα derived SFR and the strength of the Lyα emission but our sample is small. Our observations cover regions of at most 3 kpc in diameter and may miss a significant fraction of the resonantly scattered Lyα emission. This work is supported by NASA grant N1317.

The Relationship Between Stellar Populations and Lyα Emission in Lyman Break Galaxies

NASA Astrophysics Data System (ADS)

Kornei, Katherine; Shapley, A. E.; Erb, D. K.; Steidel, C. C.; Reddy, N. A.; Pettini, M.; Bogosavljevic, M.

2010-01-01

We present the results of a photometric and spectroscopic survey of 321 Lyman break galaxies (LBGs) at z ˜ 3 to investigate systematically the relationship between Lyα emission and stellar populations. Lyα equivalent widths (EWs) were calculated from rest-frame UV spectroscopy and optical/near-infrared/Spitzer photometry was used in population synthesis modeling to derive the key properties of age, dust extinction, star formation rate (SFR), and stellar mass. We directly compare the stellar populations of LBGs with and without strong Lyα emission, where we designate the former group (EW ≥ 20 angstroms) as Lyα-emitters (LAEs) and the latter group (EW < 20 angstroms) as non-LAEs. This controlled method of comparing objects from the same UV luminosity distribution represents an improvement over previous studies in which the stellar populations of LBGs and narrowband-selected LAEs were contrasted, where the latter were often intrinsically fainter in broadband filters by an order of magnitude simply due to different selection criteria. Using a variety of statistical tests, we find that Lyα equivalent width and age, SFR, and dust extinction, respectively, are significantly correlated in the sense that objects with strong Lyα emission also tend to be older, lower in star formation rate, and less dusty than objects with weak Lyα emission, or the line in absorption. We accordingly conclude that, within the LBG sample, objects with strong Lyα emission represent a later stage of galaxy evolution in which supernovae-induced outflows have reduced the dust covering fraction. We also examined the hypothesis that the attenuation of Lyα photons is lower than that of the continuum, as proposed by some, but found no evidence to support this picture.

Camptothecin-producing endophytic fungus Trichoderma atroviride LY357: isolation, identification, and fermentation conditions optimization for camptothecin production.

PubMed

Pu, Xiang; Qu, Xixing; Chen, Fei; Bao, Jinku; Zhang, Guolin; Luo, Yinggang

2013-11-01

Camptothecin (CPT), the third largest anticancer drug, is produced mainly by Camptotheca acuminata and Nothapodytes foetida. CPT itself is the starting material for clinical CPT-type drugs, but the plant-derived CPT cannot support the heavy demand from the global market. Research efforts have been made to identify novel sources for CPT. In this study, three CPT-producing endophytic fungi, Aspergillus sp. LY341, Aspergillus sp. LY355, and Trichoderma atroviride LY357, were isolated and identified from C. acuminata. Most CPT produced by these fungi was found in the fermentation broth, and their corresponding CPT yields were 7.93, 42.92, and 197.82 μg l(-1), respectively. The CPT-producing capability of LY341 and LY355 was completely lost after repeat subculturing. A substantial decrease of CPT production was also observed in the second generation of LY357. However, a stable and sustainable production of CPT was found from the second generation through the eighth generation of LY357. The fermentation medium, time, pH, temperature, and agitation rate were optimized for CPT production. Methyl jasmonate and XAD16 were proven to be an optimum elicitor and adsorbent resin, respectively, in view of that CPT yield was increased 3.4- and 11-fold through their use. A 50- to 75-fold increase of CPT yield was obtained when the optimized fermentation conditions, elicitor, and adsorbent resin were combined and applied to the culture of the seventh and eighth generations of LY357, and the highest CPT yield was 142.15 μg l(-1). The CPT-producing T. atroviride LY357 paves a potential to uncover the mysteries of CPT biosynthesis.

The Diversity of Diffuse Ly α Nebulae around Star-forming Galaxies at High Redshift

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xue, Rui; Lee, Kyoung-Soo; Dey, Arjun

2017-03-10

We report the detection of diffuse Ly α emission, or Ly α halos (LAHs), around star-forming galaxies at z ≈ 3.78 and 2.66 in the NOAO Deep Wide-Field Survey Boötes field. Our samples consist of a total of ∼1400 galaxies, within two separate regions containing spectroscopically confirmed galaxy overdensities. They provide a unique opportunity to investigate how the LAH characteristics vary with host galaxy large-scale environment and physical properties. We stack Ly α images of different samples defined by these properties and measure their median LAH sizes by decomposing the stacked Ly α radial profile into a compact galaxy-like andmore » an extended halo-like component. We find that the exponential scale-length of LAHs depends on UV continuum and Ly α luminosities, but not on Ly α equivalent widths or galaxy overdensity parameters. The full samples, which are dominated by low UV-continuum luminosity Ly α emitters ( M {sub UV} ≳ −21), exhibit LAH sizes of 5–6 kpc. However, the most UV- or Ly α- luminous galaxies have more extended halos with scale-lengths of 7–9 kpc. The stacked Ly α radial profiles decline more steeply than recent theoretical predictions that include the contributions from gravitational cooling of infalling gas and from low-level star formation in satellites. However, the LAH extent matches what one would expect for photons produced in the galaxy and then resonantly scattered by gas in an outflowing envelope. The observed trends of LAH sizes with host galaxy properties suggest that the physical conditions of the circumgalactic medium (covering fraction, H i column density, and outflow velocity) change with halo mass and/or star formation rates.« less

The Diversity of Diffuse Lyα Nebulae around Star-forming Galaxies at High Redshift

NASA Astrophysics Data System (ADS)

Xue, Rui; Lee, Kyoung-Soo; Dey, Arjun; Reddy, Naveen; Hong, Sungryong; Prescott, Moire K. M.; Inami, Hanae; Jannuzi, Buell T.; Gonzalez, Anthony H.

2017-03-01

We report the detection of diffuse Lyα emission, or Lyα halos (LAHs), around star-forming galaxies at z ≈ 3.78 and 2.66 in the NOAO Deep Wide-Field Survey Boötes field. Our samples consist of a total of ˜1400 galaxies, within two separate regions containing spectroscopically confirmed galaxy overdensities. They provide a unique opportunity to investigate how the LAH characteristics vary with host galaxy large-scale environment and physical properties. We stack Lyα images of different samples defined by these properties and measure their median LAH sizes by decomposing the stacked Lyα radial profile into a compact galaxy-like and an extended halo-like component. We find that the exponential scale-length of LAHs depends on UV continuum and Lyα luminosities, but not on Lyα equivalent widths or galaxy overdensity parameters. The full samples, which are dominated by low UV-continuum luminosity Lyα emitters (M UV ≳ -21), exhibit LAH sizes of 5-6 kpc. However, the most UV- or Lyα-luminous galaxies have more extended halos with scale-lengths of 7-9 kpc. The stacked Lyα radial profiles decline more steeply than recent theoretical predictions that include the contributions from gravitational cooling of infalling gas and from low-level star formation in satellites. However, the LAH extent matches what one would expect for photons produced in the galaxy and then resonantly scattered by gas in an outflowing envelope. The observed trends of LAH sizes with host galaxy properties suggest that the physical conditions of the circumgalactic medium (covering fraction, H I column density, and outflow velocity) change with halo mass and/or star formation rates.

Characterization of LY3023414, a Novel PI3K/mTOR Dual Inhibitor Eliciting Transient Target Modulation to Impede Tumor Growth.

PubMed

Smith, Michele C; Mader, Mary M; Cook, James A; Iversen, Philip; Ajamie, Rose; Perkins, Everett; Bloem, Laura; Yip, Yvonne Y; Barda, David A; Waid, Philip P; Zeckner, Douglas J; Young, Debra A; Sanchez-Felix, Manuel; Donoho, Gregory P; Wacheck, Volker

2016-10-01

The PI3K/AKT/mTOR pathway is among the most frequently altered pathways in cancer cell growth and survival. LY3023414 is a complex fused imidazoquinolinone with high solubility across a wide pH range designed to inhibit class I PI3K isoforms and mTOR kinase. Here, we describe the in vitro and in vivo activity of LY3023414. LY3023414 was highly soluble at pH 2-7. In biochemical testing against approximately 266 kinases, LY3023414 potently and selectively inhibited class I PI3K isoforms, mTORC1/2, and DNA-PK at low nanomolar concentrations. In vitro, inhibition of PI3K/AKT/mTOR signaling by LY3023414 caused G 1 cell-cycle arrest and resulted in broad antiproliferative activity in cancer cell panel screens. In vivo, LY3023414 demonstrated high bioavailability and dose-dependent dephosphorylation of PI3K/AKT/mTOR pathway downstream substrates such as AKT, S6K, S6RP, and 4E-BP1 for 4 to 6 hours, reflecting the drug's half-life of 2 hours. Of note, equivalent total daily doses of LY3023414 given either once daily or twice daily inhibited tumor growth to similar extents in multiple xenograft models, indicating that intermittent target inhibition is sufficient for antitumor activity. In combination with standard-of-care drugs, LY3023414 demonstrated additive antitumor activity. The novel, orally bioavailable PI3K/mTOR inhibitor LY3023414 is highly soluble and exhibits potent in vivo efficacy via intermittent target inhibition. It is currently being evaluated in phase I and II trials for the treatment of human malignancies. Mol Cancer Ther; 15(10); 2344-56. ©2016 AACR. ©2016 American Association for Cancer Research.

Small molecule sensitization to TRAIL is mediated via nuclear localization, phosphorylation and inhibition of chaperone activity of Hsp27

PubMed Central

Mellier, G; Liu, D; Bellot, G; Lisa Holme, A; Pervaiz, S

2013-01-01

The small chaperone protein Hsp27 confers resistance to apoptosis, and therefore is an attractive anticancer drug target. We report here a novel mechanism underlying the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) sensitizing activity of the small molecule LY303511, an inactive analog of the phosphoinositide 3-kinase inhibitor inhibitor LY294002, in HeLa cells that are refractory to TRAIL-induced apoptosis. On the basis of the fact that LY303511 is derived from LY294002, itself derived from quercetin, and earlier findings indicating that quercetin and LY294002 affected Hsp27 expression, we investigated whether LY303511 sensitized cancer cells to TRAIL via a conserved inhibitory effect on Hsp27. We provide evidence that upon treatment with LY303511, Hsp27 is progressively sequestered in the nucleus, thus reducing its protective effect in the cytosol during the apoptotic process. LY303511-induced nuclear translocation of Hsp27 is linked to its sustained phosphorylation via activation of p38 kinase and MAPKAP kinase 2 and the inhibition of PP2A. Furthermore, Hsp27 phosphorylation leads to the subsequent dissociation of its large oligomers and a decrease in its chaperone activity, thereby further compromising the death inhibitory activity of Hsp27. Furthermore, genetic manipulation of Hsp27 expression significantly affected the TRAIL sensitizing activity of LY303511, which corroborated the Hsp27 targeting activity of LY303511. Taken together, these data indicate a novel mechanism of small molecule sensitization to TRAIL through targeting of Hsp27 functions, rather than its overall expression, leading to decreased cellular protection, which could have therapeutic implications for overcoming chemotherapy resistance in tumor cells. PMID:24176848

A FOURTH H I 21 cm ABSORPTION SYSTEM IN THE SIGHT LINE OF MG J0414+0534: A RECORD FOR INTERVENING ABSORBERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanna, A.; Webb, J. K.; Curran, S. J.

2013-08-01

We report the detection of a strong H I 21 cm absorption system at z = 0.5344, as well as a candidate system at z = 0.3389, in the sight line toward the z = 2.64 quasar MG J0414+0534. This, in addition to the absorption at the host redshift and the other two intervening absorbers, takes the total to four (possibly five). The previous maximum number of 21 cm absorbers detected along a single sight line is two and so we suspect that this number of gas-rich absorbers is in some way related to the very red color of themore » background source. Despite this, no molecular gas (through OH absorption) has yet been detected at any of the 21 cm redshifts, although, from the population of 21 cm absorbers as a whole, there is evidence for a weak correlation between the atomic line strength and the optical-near-infrared color. In either case, the fact that so many gas-rich galaxies (likely to be damped Ly{alpha} absorption systems) have been found along a single sight line toward a highly obscured source may have far-reaching implications for the population of faint galaxies not detected in optical surveys, a possibility which could be addressed through future wide-field absorption line surveys with the Square Kilometer Array.« less

Ly6Chi inflammatory monocytes promote susceptibility to Leishmania donovani infection.

PubMed

Terrazas, Cesar; Varikuti, Sanjay; Oghumu, Steve; Steinkamp, Heidi M; Ardic, Nurittin; Kimble, Jennifer; Nakhasi, Hira; Satoskar, Abhay R

2017-10-31

Ly6C hi inflammatory monocytes (iMO) are critical for host defense against toxoplasmosis and malaria but their role in leishmaniasis is unclear. In this study, we report a detrimental role of Ly6C hi iMOs in visceral leishmaniasis (VL) caused by Leishmania donovani. We demonstrate that Ly6C hi iMOs are continuously recruited into the spleen and liver during L. donovani infection and they are preferential targets for the parasite. Using microarray-based gene expression profiling, we show that Ly6C hi iMOs isolated from the infected liver and spleen have distinct phenotypic and activation profiles. Furthermore, we demonstrate that blocking the recruitment of Ly6C hi iMOs into the liver and spleen during L. donovani infection using a CCR2 antagonist reduces the frequency of the pathogenic IFN-γ/IL10 dual producer CD4+ T cells in the spleen and leads to a significant reduction in parasite loads in the liver and spleen. Using STAT1-/- mice we show that STAT1 is critical for mediating the recruitment of Ly6C hi iMOs into organs during L. donovani infection, and adaptive transfer of wild type Ly6C hi iMOs into STAT1-/- recipients renders them susceptible to disease. Our findings reveal an unexpected pathogenic role for Ly6C hi iMOs in promoting parasite survival in VL and open the possibility of targeting this population for host-directed therapy during VL.

Low-redshift Lyman continuum leaking galaxies with high [O III]/[O II] ratios

NASA Astrophysics Data System (ADS)

Izotov, Y. I.; Worseck, G.; Schaerer, D.; Guseva, N. G.; Thuan, T. X.; Fricke, K. J.; Verhamme, A.; Orlitová, I.

2018-05-01

We present observations with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope of five star-forming galaxies at redshifts z in the range 0.2993 - 0.4317 and with high emission-line flux ratios O32 = [O III]λ5007/[O II]λ3727 ˜ 8 - 27 aiming to detect the Lyman continuum (LyC) emission. We detect LyC emission in all galaxies with the escape fractions fesc(LyC) in a range of 2 - 72 per cent. A narrow Lyα emission line with two peaks in four galaxies and with three peaks in one object is seen in medium-resolution COS spectra with a velocity separation between the peaks Vsep varying from ˜153 km s-1 to ˜ 345 km s-1. We find a general increase of the LyC escape fraction with increasing O32 and decreasing stellar mass M⋆, but with a large scatter of fesc(LyC). A tight anti-correlation is found between fesc(LyC) and Vsep making Vsep a good parameter for the indirect determination of the LyC escape fraction. We argue that one possible source driving the escape of ionizing radiation is stellar winds and radiation from hot massive stars.

Positive regulation of plasmacytoid dendritic cell function via Ly49Q recognition of class I MHC

PubMed Central

Tai, Lee-Hwa; Goulet, Marie-Line; Belanger, Simon; Toyama-Sorimachi, Noriko; Fodil-Cornu, Nassima; Vidal, Silvia M.; Troke, Angela D.; McVicar, Daniel W.; Makrigiannis, Andrew P.

2008-01-01

Plasmacytoid dendritic cells (pDCs) are an important source of type I interferon (IFN) during initial immune responses to viral infections. In mice, pDCs are uniquely characterized by high-level expression of Ly49Q, a C-type lectin-like receptor specific for class I major histocompatibility complex (MHC) molecules. Despite having a cytoplasmic immunoreceptor tyrosine-based inhibitory motif, Ly49Q was found to enhance pDC function in vitro, as pDC cytokine production in response to the Toll-like receptor (TLR) 9 agonist CpG-oligonucleotide (ODN) could be blocked using soluble monoclonal antibody (mAb) to Ly49Q or H-2Kb. Conversely, CpG-ODN–dependent IFN-α production by pDCs was greatly augmented upon receptor cross-linking using immobilized anti-Ly49Q mAb or recombinant H-2Kb ligand. Accordingly, Ly49Q-deficient pDCs displayed a severely reduced capacity to produce cytokines in response to TLR7 and TLR9 stimulation both in vitro and in vivo. Finally, TLR9-dependent antiviral responses were compromised in Ly49Q-null mice infected with mouse cytomegalovirus. Thus, class I MHC recognition by Ly49Q on pDCs is necessary for optimal activation of innate immune responses in vivo. PMID:19075287

[Diffusion of fluorescent and magnetic molecular probes in brain interstitial space].

PubMed

Li, Huai-ye; Zhao, Yue; Zuo, Long; Fu, Yu; Li, Nan; Yuan, Lan; Zhang, Shu-jia; Han, Hong-bin

2015-08-18

To compare the diffusion properties of fluorescent probes dextran-tetramethylrhodamine (DT) and lucifer yellow CH (LY) and magnetic probe gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) in porous media and to screen out a suitable fluorescent probe for optical imaging of brain interstitial space (ISS). Agarose gels sample were divided into DT group, LY group and Gd-DTPA group, and the corresponding molecular probes were imported in each group. The dynamic diffusions of DT and LY in agarose gels at different time points (15, 30, 45, 60, 90, and 120 min) were scanned with laser scanning confocal microscope, the dynamic diffusion of Gd-DTPA was imaged with magnetic resonance imaging. The average diffusion speed of LY were demonstrated to be consistent with those of Gd-DTPA. The LY was introduced into caudate putamen of 18 rats, respectively, the diffusion of LY in the sequential slices of rat brain at different time points (0.5, 1, 2, 3, 7, 11 h) were scanned, and the results were compared with those of rats' brain with Gd-DTPA imported and imaged in vivo with magnetic resonance imaging. The diffusions of the three probes were isotropic in the agarose gels, and the average diffusion speeds of DT, LY and Gd-DTPA were: (0.07±0.02)×10(-2) mm2/s, (1.54±0.47)×10(-2) mm2/s, (1.45±0.50)×10(-2) mm2/s, respectively. The speed of DT was more slower than both LY and Gd-DTPA (ANOVA, F=367.15, P<0.001; Post-Hoc LSD, P<0.001), and there was no significant difference between the speeds of LY and Gd-DTPA (Post-Hoc LSD, P=0.091). The variation tendency of diffusion area of DT was different with both that of LY and that of Gd-DTPA (Bonferroni correction, α=0.0125, P<0.001), and there was no significant difference between LY and Gd-DTPA (Bonferroni correction, α=0.0125, P=0.203), in analysis by repeated measures data of ANOVA. The diffusions of LY and Gd-DTPA were anisotropy in rat caudate putamen,and the average diffusion speeds of LY and Gd-DTPA were: (1.03±0.29)×10(-3) mm2/s, (0.81±0.27)×10(-3) mm2/s, respectively, no significant difference was demonstrated (t=0.759, P=0.490); half-time of single intensity of LY and Gd-DTPA was (2.58±0.04) h, (2.46±0.10) h, respectively, no significant difference was found (t=2.025, P=0.113). The diffusion area ratios between LY and Gd-DTPA in rat caudate putamen was not statistically different at hours 0.5, 1, 2, 3 and 7 (t=2.249, P=0.088; t=2.582, P=0.061; t=1.966, P=0.121; t=0.132, P=0.674; t=0.032, P=0.976), while, a slightly difference was found at 11 h (t=2.917, P=0.043,in analysis by t test). LY present the same diffusion property with Gd-DTPA in porous media witch including agarose gels and live rat brain tissue, indicates that LY is a suitable fluorescent probe for optical imaging of brain ISS, and it can be used for microscopic, macro and in vitro measure of brain ISS.

Effects of naltrexone and LY255582 on ethanol maintenance, seeking, and relapse responding by alcohol-preferring (P) rats.

PubMed

Dhaher, Ronnie; Toalston, Jamie E; Hauser, Sheketha R; Bell, Richard L; McKinzie, David L; McBride, William J; Rodd, Zachary A

2012-02-01

Research indicates opioid antagonists can reduce alcohol drinking in rodents. However, tests examining the effects of opioid antagonists on ethanol seeking and relapse behavior have been limited. The present study examined the effects of two opioid antagonists on ethanol maintenance, seeking, and relapse responding by alcohol-preferring (P) rats. Adult P rats were self-trained in two-lever operant chambers to self-administer 15% (vol/vol) ethanol on a fixed-ratio 5 (FR5) versus water on a FR1 concurrent schedule of reinforcement in daily 1-h sessions. After 10 weeks, rats underwent extinction training, followed by 2 weeks in their home cages. Rats were then returned to the operant chambers without ethanol or water to measure responses on the ethanol and water levers for four sessions. After a subsequent 2 weeks in the home cage, without access to ethanol, rats were returned to the operant chambers with ethanol and water available. Effects of antagonists on maintenance responding were tested after several weeks of daily 1-h sessions. Naltrexone (NAL; 1-10mg/kg, subcutaneously [s.c.]; n=8/dose), LY255582 (LY; 0.03-1mg/kg, s.c.; n=8/dose), or vehicle were injected 30min before the first session (in the absence of ethanol), following 2 weeks in their home cages, and for four consecutive sessions of ethanol self-administration under maintenance and relapse conditions. Both NAL and LY reduced responses on the ethanol lever without any fluids present, and ethanol self-administration under relapse and on-going drinking conditions, with LY being more potent than NAL. Both NAL and LY were less effective in reducing responding in the absence of ethanol than in reducing ethanol self-administration. Overall, the results indicate that the opioid system is involved in mediating ethanol seeking, and ethanol self-administration under relapse and on-going alcohol drinking, but that different neurocircuits may underlie these behaviors. Published by Elsevier Inc.

Stacking the Cosmic Web in fluorescent Ly α emission with MUSE

NASA Astrophysics Data System (ADS)

Gallego, Sofia G.; Cantalupo, Sebastiano; Lilly, Simon; Marino, Raffaella Anna; Pezzulli, Gabriele; Schaye, Joop; Wisotzki, Lutz; Bacon, Roland; Inami, Hanae; Akhlaghi, Mohammad; Tacchella, Sandro; Richard, Johan; Bouche, Nicolas F.; Steinmetz, Matthias; Carollo, Marcella

2018-04-01

Cosmological simulations suggest that most of the matter in the Universe is distributed along filaments connecting galaxies. Illuminated by the cosmic UV background (UVB), these structures are expected to glow in fluorescent Ly α emission with a surface brightness (SB) that is well below current limits for individual detections. Here, we perform a stacking analysis of the deepest MUSE/VLT data using three-dimensional regions (subcubes) with orientations determined by the position of neighbouring Ly α galaxies at 3 < z < 4. Our method increase the probability of detecting filamentary Ly α emission, provided that these structures are Lyman-limit systems (LLSs). By stacking 390 oriented subcubes we reach a 2σ sensitivity level of SB ≈ 0.44 × 10-20 erg s-1 cm-2 arcsec-2 in an aperture of 1 arcsec2 × 6.25 Å, three times below the expected fluorescent Ly α signal from the Haardt & Madau UVB at z ˜ 3.5. No detectable emission is found on intergalactic scales, implying that at least two thirds of our subcubes do not contain oriented LLSs. On the other hand, significant emission is detected in the circumgalactic medium (CGM) in the direction of the neighbours. The signal is stronger for galaxies with a larger number of neighbours and appears to be independent of any other galaxy properties. We estimate that preferentially oriented satellite galaxies cannot contribute significantly to this signal, suggesting instead that gas densities in the CGM are typically larger in the direction of neighbouring galaxies on cosmological scales.

Ginkgolide B preconditioning protects neurons against ischaemia-induced apoptosis.

PubMed

Wu, Xiaomei; Qian, Zhongming; Ke, Ya; Du, Fang; Zhu, Li

2009-01-01

Ischaemic preconditioning (IP) has been reported to protect the brain against subsequent lethal ischaemia, but it has not been used clinically to prevent ischaemic injury because of safety concerns. The aim of the present study was to see whether Ginkgolide B (GB) is capable of preconditioning as IP to protect neurons against ischaemic injury; if so, which mechanism is involved. Cultured mouse cortical neurons at day 8 were pre-treated with GB (120 micromol/l) for 24 hrs or exposed to short-term ischaemia (1 hr) followed by 24-hr normal culture to induce IP before being treated with severe ischaemia (5 hrs). GB and IP significantly increased cell viability, expression of hypoxia-inducible factor-1 alpha (HIF-1alpha), erythropoietin (EPO), phosphorylated Bad at serine 136 (136p-Bad) and phosphorylated glycogen synthase kinase- 3beta at serine 9 (p-GSK-3beta), and decreased the percentage of apoptotic cells and the level of active caspase-3 in severely ischaemic neurons. Moreover, LY294002 that is a specific inhibitor of phosphatidylinositol 3-kinase (PI3K) significantly reduced the enhanced expression of HIF-1alpha, EPO and 136p-Bad induced by GB and IP. These results suggest that GB, like IP in neurons, is capable of preconditioning against ischaemia-induced apoptosis, the mechanism of which may involve the PI3K signalling pathway.

Pluto's Extended Atmosphere: New Horizons Alice Lyman-α Imaging

NASA Astrophysics Data System (ADS)

Retherford, Kurt D.; Gladstone, G. Randall; Stern, S. Alan; Weaver, Harold A.; Young, Leslie A.; Ennico, Kimberly A.; Olkin, Cathy B.; Cheng, Andy F.; Greathouse, Thomas K.; Hinson, David P.; Kammer, Joshua A.; Linscott, Ivan R.; Parker, Alex H.; Parker, Joel Wm.; Pryor, Wayne R.; Schindhelm, Eric; Singer, Kelsi N.; Steffl, Andrew J.; Strobel, Darrell F.; Summers, Michael E.; Tsang, Constantine C. C.; Tyler, G. Len; Versteeg, Maarten H.; Woods, William W.; Cunningham, Nathaniel J.; Curdt, Werner

2015-11-01

Pluto's upper atmosphere is expected to extend several planetary radii, proportionally more so than for any planet in our solar system. Atomic hydrogen is readily produced at lower altitudes due to photolysis of methane and transported upward to become an important constituent. The Interplanetary Medium (IPM) provides a natural light source with which to study Pluto's atomic hydrogen atmosphere. While direct solar Lyman-α emissions dominate the signal at 121.6 nm at classical solar system distances, the contribution of diffuse illumination by IPM Lyman-α sky-glow is roughly on par at Pluto (Gladstone et al., Icarus, 2015). Hydrogen atoms in Pluto's upper atmosphere scatter these bright Lyα emission lines, and detailed simulations of the radiative transfer for these photons indicate that Pluto would appear dark against the IPM Lyα background. The Pluto-Alice UV imaging spectrograph on New Horizons conducted several observations of Pluto during the encounter to search for airglow emissions, characterize its UV reflectance spectra, and to measure the radial distribution of IPM Lyα near the disk. Our early results suggest that these model predictions for the darkening of IPM Lyα with decreasing altitude being measureable by Pluto-Alice were correct. We'll report our progress toward extracting H and CH4 density profiles in Pluto's upper atmosphere through comparisons of these data with detailed radiative transfer modeling. These New Horizons findings will have important implications for determining the extent of Pluto's atmosphere and related constraints to high-altitude vertical temperature structure and atmospheric escape.This work was supported by NASA's New Horizons project.

Metallicity Evolution of Damped Lyα Systems Out to z ~ 5

NASA Astrophysics Data System (ADS)

Rafelski, Marc; Wolfe, Arthur M.; Prochaska, J. Xavier; Neeleman, Marcel; Mendez, Alexander J.

2012-08-01

We present chemical abundance measurements for 47 damped Lyα (DLA) systems, 30 at z > 4, observed with the Echellette Spectrograph and Imager and the High Resolution Echelle Spectrometer on the Keck telescopes. H I column densities of the DLAs are measured with Voigt profile fits to the Lyα profiles, and we find an increased number of false DLA identifications with Sloan Digital Sky Survey at z > 4 due to the increased density of the Lyα forest. Ionic column densities are determined using the apparent optical depth method, and we combine our new metallicity measurements with 195 from previous surveys to determine the evolution of the cosmic metallicity of neutral gas. We find the metallicity of DLAs decreases with increasing redshift, improving the significance of the trend and extending it to higher redshifts, with a linear fit of -0.22 ± 0.03 dex per unit redshift from z = 0.09-5.06. The metallicity "floor" of ≈1/600 solar continues out to z ~ 5, despite our sensitivity for finding DLAs with much lower metallicities. However, this floor is not statistically different from a steep tail to the distribution. We also find that the intrinsic scatter of metallicity among DLAs of ~0.5 dex continues out to z ~ 5. In addition, the metallicity distribution and the α/Fe ratios of z > 2 DLAs are consistent with being drawn from the same parent population with those of halo stars. It is therefore possible that the halo stars in the Milky Way formed out of gas that commonly exhibits DLA absorption at z > 2.

The escape of Lyman photons from a young starburst: the case of Haro11†

NASA Astrophysics Data System (ADS)

Hayes, Matthew; Östlin, Göran; Atek, Hakim; Kunth, Daniel; Mas-Hesse, J. Miguel; Leitherer, Claus; Jiménez-Bailón, Elena; Adamo, Angela

2007-12-01

Lyman α (Lyα) is one of the dominant tools used to probe the star-forming galaxy population at high redshift (z). However, astrophysical interpretations of data drawn from Lyα alone hinge on the Lyα escape fraction which, due to the complex radiative transport, may vary greatly. Here, we map the Lyα emission from the local luminous blue compact galaxy Haro11, a known emitter of Lyα and the only known candidate for low-z Lyman continuum emission. To aid in the interpretation, we perform a detailed ultraviolet and optical multiwavelength analysis and model the stellar population, dust distribution, ionizing photon budget, and star-cluster population. We use archival X-ray observations to further constrain properties of the starburst and estimate the neutral hydrogen column density. The Lyα morphology is found to be largely symmetric around a single young star-forming knot and is strongly decoupled from other wavelengths. From general surface photometry, only very slight correlation is found between Lyα and Hα, E(B - V), and the age of the stellar population. Only around the central Lyα bright cluster do we find the Lyα/Hα ratio at values predicted by the recombination theory. The total Lyα escape fraction is found to be just 3 per cent. We compute that ~90 per cent of the Lyα photons that escape do so after undergoing multiple resonance scattering events, masking their point of origin. This leads to a largely symmetric distribution and, by increasing the distance that photons must travel to escape, decreases the escape probability significantly. While dust must ultimately be responsible for the destruction of Lyα, it plays a little role in governing the observed morphology, which is regulated more by interstellar medium kinematics and geometry. We find tentative evidence for local Lyα equivalent width in the immediate vicinity of star clusters being a function of cluster age, consistent with hydrodynamic studies. We estimate the intrinsic production of ionizing photons and put further constraints of ~9 per cent on the escaping fraction of photons at 900Å. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS 5-26555. These observations are associated with programmes #GO9470 and #GO10575. Based on observations made with ESO Telescopes at the La Silla Observatories under programme ID 073.B-0785. ‡ E-mail: matthew@astro.su.se

tLyP-1-conjugated mesoporous silica nanoparticles for tumor targeting and penetrating hydrophobic drug delivery

NASA Astrophysics Data System (ADS)

Xu, Baiyao; Ju, Yang; Song, Guanbin; Cui, Yanbin

2013-12-01

Mesoporous silica nanoparticles (MSNs) are among the most appealing candidates for targeted drug delivery, a process for which it is essential that nanoparticles be internalized into targeted cells with high speed and efficiency. Therefore, it is necessary to conjugate a targeting ligand to the surface of a nanocarrier in order to trigger rapid receptor-mediated endocytosis and effective cellular uptake, which occurs following recognition and selective binding to a target cell's membrane receptor. Here, a tumor targeting and penetrating drug delivery system (DDS) based on MSNs ( 100 nm in size) is described. The MSNs were functionalized by engrafting with the tumor-homing and penetrating peptide tLyP-1. The fabricated MSN-tLyP-1 loaded with camptothecin (CPT) showed a robust targeting and penetrating efficiency to HeLa cells and MCF-7 cells and induced the death of these cells. Moreover, the adverse side effect of CPT on human mesenchymal stem cells (hMSCs) was minimized, because the nanoparticles were selectively targeted to the tumor cells, and little hydrophobic CPT was released into the culture medium or blood. The results indicate that the MSN-tLyP-1 DDS has great potential for the delivery of hydrophobic anticancer drugs to target tumors.

Survivin and NAIP in Human Benign Prostatic Hyperplasia: Protective Role of the Association of Serenoa repens, Lycopene and Selenium from the Randomized Clinical Study.

PubMed

Morgia, Giuseppe; Micali, Antonio; Rinaldi, Mariagrazia; Irrera, Natasha; Marini, Herbert; Puzzolo, Domenico; Pisani, Antonina; Privitera, Salvatore; Russo, Giorgio I; Cimino, Sebastiano; Ieni, Antonio; Trichilo, Vincenzo; Altavilla, Domenica; Squadrito, Francesco; Minutoli, Letteria

2017-03-22

Benign prostatic hyperplasia (BPH) treatment includes the apoptosis machinery modulation through the direct inhibition of caspase cascade. We previously demonstrated that Serenoa repens (Ser) with lycopene (Ly) and selenium (Se) reawakened apoptosis by reducing survivin and neuronal apoptosis inhibitory protein (NAIP) levels in rats. The aim of this study was to evaluate the effectiveness of Ser-Se-Ly association on survivin and NAIP expression in BPH patients. Ninety patients with lower urinary tract symptoms (LUTS) due to clinical BPH were included in this randomized, double-blind, placebo-controlled trial. Participants were randomly assigned to receive placebo (Group BPH + placebo, n = 45) or Ser-Se-Ly association (Group BPH + Ser-Se-Ly; n = 45) for 3 months. At time 0, all patients underwent prostatic biopsies. After 3 months of treatment, they underwent prostatic re-biopsy and specimens were collected for molecular, morphological, and immunohistochemical analysis. After 3 months, survivin and NAIP were significantly decreased, while caspase-3 was significantly increased in BPH patients treated with Ser-Se-Ly when compared with the other group. In BPH patients treated with Ser-Se-Ly for 3 months, the glandular epithelium was formed by a single layer of cuboidal cells. PSA showed high immunoexpression in all BPH patients and a focal positivity in Ser-Se-Ly treated patients after 3 months. Evident prostate specific membrane antigen (PSMA) immunoexpression was shown in all BPH patients, while no positivity was present after Ser-Se-Ly administration. Ser-Se-Ly proved to be effective in promoting apoptosis in BPH patients.

Interaction of LY171883 and other peroxisome proliferators with fatty-acid-binding protein isolated from rat liver.

PubMed Central

Cannon, J R; Eacho, P I

1991-01-01

Fatty-acid-binding protein (FABP) is a 14 kDa protein found in hepatic cytosol which binds and transports fatty acids and other hydrophobic ligands throughout the cell. The purpose of this investigation was to determine whether LY171883, a leukotriene D4 antagonist, and other peroxisome proliferators bind to FABP and displace an endogenous fatty acid. [3H]Oleic acid was used to monitor the elution of FABP during chromatographic purification. [14C]LY171883 had a similar elution profile when substituted in the purification, indicating a common interaction with FABP. LY171883 and its structural analogue, LY189585, as well as the hypolipidaemic peroxisome proliferators clofibric acid, ciprofibrate, bezafibrate and WY14,643, displaced [3H]oleic acid binding to FABP. Analogues of LY171883 that do not induce peroxisome proliferation only weakly displaced oleate binding. [3H]Ly171883 bound directly to FABP with a Kd of 10.8 microM, compared with a Kd of 0.96 microM for [3H]oleate. LY171883 binding was inhibited by LY189585, clofibric acid, ciprofibrate and bezafibrate. These findings demonstrate that peroxisome proliferators, presumably due to their structural similarity to fatty acids, are able to bind to FABP and displace an endogenous ligand from its binding site. Interaction of peroxisome proliferators with FABP may be involved in perturbations of fatty acid metabolism caused by these agents as well as in the development of the pleiotropic response of peroxisome proliferation. Images Fig. 2. PMID:1747111

Lyα Escape from z ~ 0.03 Star-forming Galaxies: The Dominant Role of Outflows

NASA Astrophysics Data System (ADS)

Wofford, Aida; Leitherer, Claus; Salzer, John

2013-03-01

The usefulness of H I Lyα photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies. These processes can only be observed in detail out to a few × 100 Mpc. Past nearby (z < 0.3) spectroscopic studies are based on small samples and/or kinematically unresolved data. Taking advantage of the high sensitivity of Hubble Space Telescope's Cosmic Origins Spectrograph (COS), we observed the Lyα lines of 20 Hα-selected galaxies located at =0.03. The galaxies cover a broad range of luminosity, oxygen abundance, and reddening. In this paper, we characterize the observed Lyα lines and establish correlations with fundamental galaxy properties. We find seven emitters. These host young (<=10 Myr) stellar populations have rest-frame equivalent widths in the range 1-12 Å, and have Lyα escape fractions within the COS aperture in the range 1%-12%. One emitter has a double-peaked Lyα with peaks 370 km s-1 apart and a stronger blue peak. Excluding this object, the emitters have Lyα and O I λ1302 offsets from Hα in agreement with expanding-shell models and Lyman break galaxies observations. The absorbers have offsets that are almost consistent with a static medium. We find no one-to-one correspondence between Lyα emission and age, metallicity, or reddening. Thus, we confirm that Lyα is enhanced by outflows and is regulated by the dust and H I column density surrounding the hot stars.

Discovery of a Very Bright and Intrinsically Very Luminous, Strongly Lensed Lyα Emitting Galaxy at z = 2.82 in the BOSS Emission-Line Lens Survey

NASA Astrophysics Data System (ADS)

Marques-Chaves, Rui; Pérez-Fournon, Ismael; Shu, Yiping; Martínez-Navajas, Paloma I.; Bolton, Adam S.; Kochanek, Christopher S.; Oguri, Masamune; Zheng, Zheng; Mao, Shude; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Brownstein, Joel R.

2017-01-01

We report the discovery of a very bright (r = 20.16), highly magnified, and yet intrinsically very luminous Lyα emitter (LAE) at z=2.82. This system comprises four images in the observer plane with a maximum separation of ˜ 6\\prime\\prime and it is lensed by a z=0.55 massive early-type galaxy. It was initially identified in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey for GALaxy-Lyα EmitteR sYstems survey, and follow-up imaging and spectroscopic observations using the Gran Telescopio Canarias and William Herschel Telescope confirmed the lensing nature of this system. A lens model using a singular isothermal ellipsoid in an external shear field reproduces the main features of the system quite well, yielding an Einstein radius of 2.″95 ± 0.″10, and a total magnification factor for the LAE of 8.8 ± 0.4. This LAE is one of the brightest and most luminous galaxy-galaxy strong lenses known. We present initial imaging and spectroscopy showing the basic physical and morphological properties of this lensed system. Based on observations made with the Gran Telescopio Canarias (GTC) and William Herschel Telescope (WHT), in the Spanish Observatorio del Roque de los Muchachos of the IAC, under Directors Discretionary Time (DDT programs IDs: GTC2016-054 and DDT2016-077).

Activating receptors promote NK cell expansion for maintenance, IL-10 production, and CD8 T cell regulation during viral infection.

PubMed

Lee, Seung-Hwan; Kim, Kwang-Sin; Fodil-Cornu, Nassima; Vidal, Silvia M; Biron, Christine A

2009-09-28

Natural killer (NK) cells have the potential to deliver both direct antimicrobial effects and regulate adaptive immune responses, but NK cell yields have been reported to vary greatly during different viral infections. Activating receptors, including the Ly49H molecule recognizing mouse cytomegalovirus (MCMV), can stimulate NK cell expansion. To define Ly49H's role in supporting NK cell proliferation and maintenance under conditions of uncontrolled viral infection, experiments were performed in Ly49h(-/-), perforin 1 (Prf1)(-/-), and wild-type (wt) B6 mice. NK cell numbers were similar in uninfected mice, but relative to responses in MCMV-infected wt mice, NK cell yields declined in the absence of Ly49h and increased in the absence of Prf1, with high rates of proliferation and Ly49H expression on nearly all cells. The expansion was abolished in mice deficient for both Ly49h and Prf1 (Ly49h(-/-)Prf1(-/-)), and negative consequences for survival were revealed. The Ly49H-dependent protection mechanism delivered in the absence of Prf1 was a result of interleukin 10 production, by the sustained NK cells, to regulate the magnitude of CD8 T cell responses. Thus, the studies demonstrate a previously unappreciated critical role for activating receptors in keeping NK cells present during viral infection to regulate adaptive immune responses.

A Deep Narrowband Imaging Search for C IV and He II Emission from Lyα Blobs

NASA Astrophysics Data System (ADS)

Arrigoni Battaia, Fabrizio; Yang, Yujin; Hennawi, Joseph F.; Prochaska, J. Xavier; Matsuda, Yuichi; Yamada, Toru; Hayashino, Tomoki

2015-05-01

We conduct a deep narrowband imaging survey of 13 Lyα blobs (LABs) located in the SSA22 proto-cluster at z ˜ 3.1 in the C iv and He ii emission lines in an effort to constrain the physical process powering the Lyα emission in LABs. Our observations probe down to unprecedented surface brightness (SB) limits of (2.1-3.4) × 10-18 erg s-1 cm-2 arcsec-2 per 1 arcsec2 aperture (5σ) for the He ii λ1640 and C iv λ1549 lines, respectively. We do not detect extended He ii and C iv emission in any of the LABs, placing strong upper limits on the He ii/Lyα and C iv/Lyα line ratios, of 0.11 and 0.16, for the brightest two LABs in the field. We conduct detailed photoionization modeling of the expected line ratios and find that, although our data constitute the deepest ever observations of these lines, they are still not deep enough to rule out a scenario where the Lyα emission is powered by the ionizing radiation from an obscured active galactic nucleus. Our models can accommodate He ii/Lyα and C iv/Lyα ratios as low as ≃0.05 and ≃0.07, respectively, implying that one needs to reach SB as low as (1-1.5) × 10-18 erg s-1 cm-2 arcsec-2 (at 5σ) in order to rule out a photoionization scenario. These depths will be achievable with the new generation of image-slicing integral field units such as the Multi Unit Spectroscopic Explorer (MUSE) on VLT and the Keck Cosmic Web Imager (KCWI). We also model the expected He ii/Lyα and C iv/Lyα in a different scenario, where Lyα emission is powered by shocks generated in a large-scale superwind, but find that our observational constraints can only be met for shock velocities vs ≳ 250 km s-1, which appear to be in conflict with recent observations of quiescent kinematics in LABs. .

Discovery of LY2457546: a multi-targeted anti-angiogenic kinase inhibitor with a novel spectrum of activity and exquisite potency in the acute myelogenous leukemia-Flt-3-internal tandem duplication mutant human tumor xenograft model.

PubMed

Burkholder, Timothy P; Clayton, Joshua R; Rempala, Mark E; Henry, James R; Knobeloch, John M; Mendel, David; McLean, Johnathan A; Hao, Yan; Barda, David A; Considine, Eileen L; Uhlik, Mark T; Chen, Yuefeng; Ma, Liandong; Bloem, Laura J; Akunda, Jacqueline K; McCann, Denis J; Sanchez-Felix, Manuel; Clawson, David K; Lahn, Michael M; Starling, James J

2012-06-01

LY2457546 is a potent and orally bioavailable inhibitor of multiple receptor tyrosine kinases involved in angiogenic and tumorigenic signalling. In biochemical and cellular assays, LY2457546 demonstrates potent activity against targets that include VEGFR2 (KDR), PDGFRβ, FLT-3, Tie-2 and members of the Eph family of receptors. With activities against both Tie2 and Eph receptors, LY2457546 possesses an activity profile that distinguishes it from multikinase inhibitors. When compared head to head with sunitinib, LY2457546 was more potent for inhibition of endothelial tube formation in an in vitro angiogenesis co-culture model with an intermittent treatment design. In vivo, LY2457546 inhibited VEGF-driven autophosphorylation of lung KDR in the mouse and rat in a dose and concentration dependent manner. LY2457546 was well tolerated and exhibited efficacy in a 13762 syngeneic rat mammary tumor model in both once and twice daily continuous dosing schedules and in mouse human tumor xenograft models of lung, colon, and prostate origin. Additionally, LY2457546 caused complete regression of well-established tumors in an acute myelogenous leukemia (AML) FLT3-ITD mutant xenograft tumor model. The observed efficacy that was displayed by LY2457546 in the AML FLT3-ITD mutant tumor model was superior to sunitinib when both were evaluated using equivalent doses normalized to in vivo inhibition of pKDR in mouse lung. LY2457546 was well tolerated in non-clinical toxicology studies conducted in rats and dogs. The majority of the toxicities observed were similar to those observed with other multi-targeted anti-angiogenic kinase inhibitors (MAKs) and included bone marrow hypocellularity, hair and skin depigmentation, cartilage dysplasia and lymphoid organ degeneration and necrosis. Thus, the unique spectrum of target activity, potent in vivo anti-tumor efficacy in a variety of rodent and human solid tumor models, exquisite potency against a clinically relevant model of AML, and non-clinical safety profile justify the advancement of LY2457546 into clinical testing.

Anti-idiotype antibody induced cellular immunity in mice transgenic for human carcinoembryonic antigen.

PubMed

Saha, Asim; Chatterjee, Sunil K; Foon, Kenneth A; Bhattacharya-Chatterjee, Malaya

2006-08-01

In the present study, we have analysed the detailed cellular immune mechanisms involved in tumour rejection in carcinoembryonic antigen (CEA) transgenic mice after immunization with dendritic cells (DC) pulsed with an anti-idiotype (Id) antibody, 3H1, which mimics CEA. 3H1-pulsed DC vaccinations resulted in induction of CEA specific cytotoxic T lymphocyte (CTL) responses in vitro and the rejection of CEA-transfected MC-38 murine colon carcinoma cells, C15, in vivo (Saha et al.,Cancer Res 2004; 64: 4995-5003). These CTL mediated major histocompatibility complex (MHC) class I-restricted tumour cell lysis, production of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and expression of Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) in response to C15 cells. CTL used perforin-, FasL-, and TRAIL-mediated death pathways to lyse C15 cells, although perforin-mediated killing was the predominant lytic mechanism in vitro. The cytokines IFN-gamma and TNF-alpha synergistically enhanced surface expression of Fas, TRAIL receptor, MHC class I and class II on C15 cells that increased the sensitivity of tumour cells to CTL lysis. CTL activity generated in 3H1-pulsed DC immunized mice was directed against an epitope defined by the idio-peptide LCD-2, derived from 3H1. In vivo lymphocyte depletion experiments demonstrated that induction of CTL response and antitumour immunity was dependent on both CD4+ and CD8+ T cells. The analysis of splenocytes of immunized mice that had rejected C15 tumour growth revealed up-regulated surface expression of memory phenotype Ly-6C and CD44 on both CD4+ and CD8+ T cells. The adoptive transfer experiments also suggested the role of both CD4+ and CD8+ T cells in this model system. Furthermore, mice that had rejected C15 tumour growth, developed tumour-specific immunological memory.

Direct Detection of The Lyman Continuum of Star-forming Galaxies at z~3

NASA Astrophysics Data System (ADS)

Vasei, Kaveh; Siana, Brian; Shapley, Alice; Alavi, Anahita; Rafelski, Marc

2018-01-01

Star-forming galaxies are widely believed to be responsible for the reionization of the Universe and much of the ionizing background at z>3. Therefore, there has been much interest in quantifying the escape fraction of the Lyman continuum (LyC) radiation of the star-forming galaxies. Yet direct detection of LyC has proven to be exceptionally challenging. Despite numerous efforts only 7 galaxies at z<2 (all with escape fractions less than 0.04) and 3 galaxies at z>2 have been robustly confirmed as LyC leakers. To avoid these challenges many studies use indirect methods to infer the LyC escape fraction. We tested these indirect methods by attempting to detect escaping LyC with a 10-orbit Hubble near-UV (F275W) image that is just below the Lyman limit at the redshift of the Cosmic Horseshoe (a lensed galaxy at z=2.4). We concluded that the measured escape fraction is lower, by more than a factor of five, than the expected escape fraction based on the indirect methods. This emphasizes that indirect determinations should only be interpreted as upper-limits. We also investigated the deepest near-UV Hubble images of the SSA22 field to detect LyC leakage from a large sample of candidate star-forming galaxies at z~3.1, whose redshift was obtained by deep Keck/LRIS spectroscopy and for which Keck narrow-band imaging was showing possible LyC leakage. The high spatial resolution of Hubble images is crucial to confirm our detections are clean from foreground contaminating galaxies, and also to ascertain the escape fraction of our final candidates. We identify five clean LyC emitting star-forming galaxies. The follow up investigation of these galaxies will significantly increase our knowledge of the LyC escape fraction and the mechanisms allowing for LyC escape.

Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies

NASA Astrophysics Data System (ADS)

Izotov, Y. I.; Schaerer, D.; Thuan, T. X.; Worseck, G.; Guseva, N. G.; Orlitová, I.; Verhamme, A.

2016-10-01

Following our first detection reported in Izotov et al., we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope. These galaxies, at redshifts of z ˜ 0.3, are characterized by high emission-line flux ratios [O III] λ5007/[O II] λ3727 ≳ 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ˜6-13 per cent, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Ly α emission lines are detected in the spectra of all four galaxies, compatible with predictions for LyC leakers. We find escape fractions of Ly α, fesc(Ly α) ˜ 20-40 per cent, among the highest known for Ly α emitting galaxies. Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the centre and exponential discs in the outskirts with disc scalelengths α in the range ˜0.6-1.4 kpc. Our galaxies are characterized by low metallicity, ˜1/8-1/5 solar, low stellar mass ˜(0.2-4) × 109 M⊙, high star formation rates, SFR ˜ 14-36 M⊙ yr-1, and high SFR densities, Σ ˜ 2-35 M⊙ yr-1 kpc-2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al., reveal that a selection for compact star-forming galaxies showing high [O III] λ5007/[O II] λ3727 ratios appears to pick up very efficiently sources with escaping LyC radiation: all five of our selected galaxies are LyC leakers.

Anti-epileptic activity of group II metabotropic glutamate receptor agonists (--)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268) and (--)-2-thia-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY389795).

PubMed

Moldrich, R X; Jeffrey, M; Talebi, A; Beart, P M; Chapman, A G; Meldrum, B S

2001-07-01

The selective group II metabotropic glutamate receptor (mGlu(2/3)) agonists (-)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268) and (-)-2-thia-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY389795) have been evaluated as anti-epileptic drugs in dilute brown agouti (DBA/2) mice, lethargic (lh/lh) mice, genetically epilepsy-prone-9 (GEP) rats and amygdala-kindled rats. Sound-induced clonic seizures in DBA/2 mice were transiently inhibited by both agonists intracerebroventricularly (i.c.v.), LY379268 ED(50)=0.08 [0.02-0.33]nmol and LY389795 ED(50)=0.82 [0.27-3.24]nmol or intraperitoneally (i.p.), LY379268 ED(50)=2.9 [0.9-9.6]mg/kg and LY389795 ED(50)=3.4 [1.0-11.7]mg/kg. Both mGlu(2/3) agonists inhibited seizures induced by the group I mGlu receptor agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG), where LY379268, i.c.v. ED(50)=0.3 [0.02-5.0]pmol and LY389795, i.c.v. ED(50)=0.03 [0.05-0.19]nmol. The spike and wave discharge (SWD) duration of absence seizures in lh/lh mice was significantly reduced by both agonists at 1 and 10nmol (i.c.v.) up to 90min following infusion. The electrically induced seizure score and afterdischarge duration of amygdala-kindled rats was partially inhibited by the agonists 30min after i.p. injection of 10mg/kg. The agonists did not inhibit sound-induced seizures in GEP rats (0.1-1mg/kg, 30min 1h, i.p.), but were proconvulsant following sound stimulus (> or =0.1mg/kg). These findings identify a potential role for mGlu(2/3) agonists in the amelioration of generalised and partial epileptic seizures.

Antiproliferative and apoptotic effect of LY2090314, a GSK-3 inhibitor, in neuroblastoma in vitro.

PubMed

Kunnimalaiyaan, Selvi; Schwartz, Victoriana K; Jackson, Iris Alao; Clark Gamblin, T; Kunnimalaiyaan, Muthusamy

2018-05-11

Neuroblastoma (NB) is a devastating disease. Despite recent advances in the treatment of NB, about 60% of high-risk NB will have relapse and therefore long-term event free survival is very minimal. We have reported that targeting glycogen synthase kinase-3 (GSK-3) may be a potential strategy to treat NB. Consequently, investigating LY2090314, a clinically relevant GSK-3 inhibitor, on NB cellular proliferation and may be beneficial for NB treatment. The effect of LY2090314 was compared with a previously studied GSK-3 inhibitor, Tideglusib. Colorimetric, clonogenic, and live-cell image confluency assays were used to study the proliferative effect of LY2090314 on NB cell lines (NGP, SK-N-AS, and SH-SY-5Y). Western blotting and caspase glo assay were performed to determine the mechanistic function of LY2090314 in NB cell lines. LY2090314 treatment exhibited significant growth reduction starting at a 20 nM concentration in NGP, SK-N-AS, and SH-SY-5Y cells. Western blot analysis indicated that growth suppression was due to apoptosis as evidenced by an increase in pro-apoptotic markers cleaved PARP and cleaved caspase-3 and a reduction in the anti-apoptotic protein, survivin. Further, treatment significantly reduced the level of cyclin D1, a key regulatory protein of the cell cycle and apoptosis. Functionally, this was confirmed by an increase in caspase activity. LY2090314 treatment reduced the expression levels of phosphorylated GSK-3 proteins and increased the stability of β-catenin in these cells. LY2090314 effectively reduces growth of both human MYCN amplified and non-amplified NB cell lines in vitro. To our knowledge, this is the first study to look at the effect of LY2090314 in NB cell lines. These results indicate that GSK-3 may be a therapeutic target for NB and provide rationale for further preclinical analysis using LY2090314.

Safety, tolerability, pharmacokinetics, and effects on human experimental pain of the selective ionotropic glutamate receptor 5 (iGluR5) antagonist LY545694 in healthy volunteers.

PubMed

Petersen, Karin L; Iyengar, Smriti; Chappell, Amy S; Lobo, Evelyn D; Reda, Haatem; Prucka, William R; Verfaille, Steven J

2014-05-01

The objective of this study was to establish in healthy volunteers the maximally tolerated multiple dose (MTMD) of the ionotropic glutamate receptor 5 antagonist LY545694 (part A), and to investigate whether that dose had analgesic or antihyperalgesic effects in the brief thermal stimulation (BTS) pain model (Part B). Part A was a double-blind, placebo-controlled study in 3 groups of 10 healthy men. To simulate an extended-release formulation, study drug was administered orally over 6hours (12 equally divided aliquots at 30-minute intervals). Part B was a double-blind, placebo-controlled, double-dummy, 3-way crossover study in 27 healthy men. At each of the 3 study periods, subjects received either LY545694 (MTMD; as determined during part A) as a simulated, twice daily extended-release formulation for 4 doses over 3days, gabapentin (600mg 8hours apart; 6 doses over 3days; positive control), or matching placebo. The BTS model was induced twice with a 1-hour interval on each of the 2 study days, before drug administration and at the time of expected peak analgesia of LY545694. Plasma exposure for LY545694 was approximately linear over the 25- to 75-mg dose range. The MTMD of LY545694 was 25mg twice daily. Areas of secondary hyperalgesia were significantly smaller after administration of LY545694 and gabapentin compared with placebo (P<.0001 and P=.0004, respectively), but there was no difference between areas after administration of gabapentin and LY545694 (P=.400). Neither gabapentin nor LY545694 reduced the painfulness of skin heating during BTS model induction. The most common treatment-emergent adverse event was dizziness. The results of this study suggest that LY545694 should be explored further as a potential treatment for chronic pain involving neuronal sensitization. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Selective Estrogen Receptor β Agonist LY500307 as a Novel Therapeutic Agent for Glioblastoma

PubMed Central

Sareddy, Gangadhara R.; Li, Xiaonan; Liu, Jinyou; Viswanadhapalli, Suryavathi; Garcia, Lauren; Gruslova, Aleksandra; Cavazos, David; Garcia, Mike; Strom, Anders M.; Gustafsson, Jan-Ake; Tekmal, Rajeshwar Rao; Brenner, Andrew; Vadlamudi, Ratna K.

2016-01-01

Glioblastomas (GBM), deadly brain tumors, have greater incidence in males than females. Epidemiological evidence supports a tumor suppressive role of estrogen; however, estrogen as a potential therapy for GBM is limited due to safety concerns. Since GBM express ERβ, a second receptor for estrogen, targeting ERβ with a selective agonist may be a potential novel GBM therapy. In the present study, we examined the therapeutic effect of the selective synthetic ERβ agonist LY500307 using in vitro and in vivo GBM models. Treatment with LY500307 significantly reduced the proliferation of GBM cells with no activity on normal astrocytes in vitro. ERβ agonists promoted apoptosis of GBM cells, and mechanistic studies using RNA sequencing revealed that LY500307 modulated several pathways related to apoptosis, cell cycle, and DNA damage response. Further, LY500307 sensitized GBM cells to several FDA-approved chemotherapeutic drugs including cisplatin, lomustine and temozolomide. LY500307 treatment significantly reduced the in vivo tumor growth and promoted apoptosis of GBM tumors in an orthotopic model and improved the overall survival of tumor-bearing mice in the GL26 syngeneic glioma model. Our results demonstrate that LY500307 has potential as a therapeutic agent for GBM. PMID:27126081

The physical properties and evolution of Lyα emitting galaxies

NASA Astrophysics Data System (ADS)

Pentericci, L.; Grazian, A.; Fontana, A.

2009-05-01

A significant fraction of high redshift starburst galaxies presents strong Lyα emission. Understanding the nature of these galaxies is important to assess the role they played in the early Universe and to shed light on the relation between the narrow band selected Lyα emitters and the Lyman break galaxies: are the Lyα emitters a subset of the general LBG population? or do they represent the youngest galaxies in their early phases of formation? We studied a sample of UV continuum selected galaxies from z~2.5 to z~6 (U, B, V and i-dropouts) from the GOODS-South survey, that have been observed spectroscopically. Using the GOODS-MUSIC catalog we investigated their physical properties, such as total masses, ages, SFRs, extinction etc as determined from a spectrophotometric fit to the multi-wavelength (U band to mid-IR) SEDs, and their dependence on the emission line characteristics. In particular we determined the nature of the LBGs with Lyα in emission and compared them to the properties of narrow band selected Lyα emitters. For U and B-dropouts we also compared the properties of LBGs with and without the Lyα emission line.

The mean ultraviolet spectrum of a representative sample of faint z ˜ 3 Lyman alpha emitters

NASA Astrophysics Data System (ADS)

Nakajima, Kimihiko; Fletcher, Thomas; Ellis, Richard S.; Robertson, Brant E.; Iwata, Ikuru

2018-06-01

We discuss the rest-frame ultraviolet (UV) emission line spectra of a large (˜100) sample of low luminosity redshift z ˜ 3.1 Lyman alpha emitters (LAEs) drawn from a Subaru imaging survey in the SSA22 survey field. Our earlier work based on smaller samples indicated that such sources have high [O III]/[O II] line ratios possibly arising from a hard ionizing spectrum that may be typical of similar sources in the reionization era. With optical spectra secured from VLT/VIMOS, we re-examine the nature of the ionizing radiation in a larger sample using the strength of the high ionization diagnostic emission lines of CIII]λ1909, CIVλ1549, HEIIλ1640, and O III]λλ1661, 1666 Å in various stacked subsets. Our analysis confirms earlier suggestions of a correlation between the strength of Ly α and CIII] emission and we find similar trends with broad-band UV luminosity and rest-frame UV colour. Using various diagnostic line ratios and our stellar photoionization models, we determine both the gas phase metallicity and hardness of the ionization spectrum characterized by ξion - the number of Lyman continuum photons per UV luminosity. We confirm our earlier suggestion that ξion is significantly larger for LAEs than for continuum-selected Lyman break galaxies, particularly for those LAEs with the faintest UV luminosities. We briefly discuss the implications for cosmic reionization if the metal-poor intensely star-forming systems studied here are representative examples of those at much higher redshift.

Pharmacological activation of estrogen receptor beta augments innate immunity to suppress cancer metastasis.

PubMed

Zhao, Linjie; Huang, Shuang; Mei, Shenglin; Yang, Zhengnan; Xu, Lian; Zhou, Nianxin; Yang, Qilian; Shen, Qiuhong; Wang, Wei; Le, Xiaobing; Lau, Wayne Bond; Lau, Bonnie; Wang, Xin; Yi, Tao; Zhao, Xia; Wei, Yuquan; Warner, Margaret; Gustafsson, Jan-Åke; Zhou, Shengtao

2018-04-17

Metastases constitute the greatest causes of deaths from cancer. However, no effective therapeutic options currently exist for cancer patients with metastasis. Estrogen receptor β (ERβ), as a member of the nuclear receptor superfamily, shows potent tumor-suppressive activities in many cancers. To investigate whether modulation of ERβ could serve as a therapeutic strategy for cancer metastasis, we examined whether the selective ERβ agonist LY500307 could suppress lung metastasis of triple-negative breast cancer (TNBC) and melanoma. Mechanistically, while we observed that LY500307 potently induced cell death of cancer cells metastasized to lung in vivo, it does not mediate apoptosis of cancer cells in vitro, indicating that the cell death-inducing effects of LY500307 might be mediated by the tumor microenvironment. Pathological examination combined with flow cytometry assays indicated that LY500307 treatment induced significant infiltration of neutrophils in the metastatic niche. Functional experiments demonstrated that LY500307-treated cancer cells show chemotactic effects for neutrophils and that in vivo neutrophil depletion by Ly6G antibody administration could reverse the effects of LY500307-mediated metastasis suppression. RNA sequencing analysis showed that LY500307 could induce up-regulation of IL-1β in TNBC and melanoma cells, which further triggered antitumor neutrophil chemotaxis. However, the therapeutic effects of LY500307 treatment for suppression of lung metastasis was attenuated in IL1B -/- murine models, due to failure to induce antitumor neutrophil infiltration in the metastatic niche. Collectively, our study demonstrated that pharmacological activation of ERβ could augment innate immunity to suppress cancer metastatic colonization to lung, thus providing alternative therapeutic options for cancer patients with metastasis.

Flavivirus internalization is regulated by a size-dependent endocytic pathway.

PubMed

Hackett, Brent A; Cherry, Sara

2018-04-17

Flaviviruses enter host cells through the process of clathrin-mediated endocytosis, and the spectrum of host factors required for this process are incompletely understood. Here we found that lymphocyte antigen 6 locus E (LY6E) promotes the internalization of multiple flaviviruses, including West Nile virus, Zika virus, and dengue virus. Perhaps surprisingly, LY6E is dispensable for the internalization of the endogenous cargo transferrin, which is also dependent on clathrin-mediated endocytosis for uptake. Since viruses are substantially larger than transferrin, we reasoned that LY6E may be required for uptake of larger cargoes and tested this using transferrin-coated beads of similar size as flaviviruses. LY6E was indeed required for the internalization of transferrin-coated beads, suggesting that LY6E is selectively required for large cargo. Cell biological studies found that LY6E forms tubules upon viral infection and bead internalization, and we found that tubule formation was dependent on RNASEK, which is also required for flavivirus internalization, but not transferrin uptake. Indeed, we found that RNASEK is also required for the internalization of transferrin-coated beads, suggesting it functions upstream of LY6E. These LY6E tubules resembled microtubules, and we found that microtubule assembly was required for their formation and flavivirus uptake. Since microtubule end-binding proteins link microtubules to downstream activities, we screened the three end-binding proteins and found that EB3 promotes virus uptake and LY6E tubularization. Taken together, these results highlight a specialized pathway required for the uptake of large clathrin-dependent endocytosis cargoes, including flaviviruses. Copyright © 2018 the Author(s). Published by PNAS.

THE MUSCLES TREASURY SURVEY. II. INTRINSIC LY α AND EXTREME ULTRAVIOLET SPECTRA OF K AND M DWARFS WITH EXOPLANETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Youngblood, Allison; France, Kevin; Loyd, R. O. Parke

2016-06-20

The ultraviolet (UV) spectral energy distributions (SEDs) of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Ly α line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar H i absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES Hubble Space Telescope Treasury Survey has obtained UV observations of 11 nearby M and Kmore » dwarfs hosting exoplanets. This paper presents the Ly α and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Ly α profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV SED from the intrinsic Ly α flux in ∼100 Å bins from 100–1170 Å. The reconstructed Ly α profiles have 300 km s{sup −1} broad cores, while >1% of the total intrinsic Ly α flux is measured in extended wings between 300 and 1200 km s{sup −1}. The Ly α surface flux positively correlates with the Mg ii surface flux and negatively correlates with the stellar rotation period. Stars with larger Ly α surface flux also tend to have larger surface flux in ions formed at higher temperatures, but these correlations remain statistically insignificant in our sample of 11 stars. We also present H i column density measurements for 10 new sightlines through the local interstellar medium.« less

Pharmacokinetics and pharmacodynamics of the cathepsin S inhibitor, LY3000328, in healthy subjects.

PubMed

Payne, Christopher D; Deeg, Mark A; Chan, Melanie; Tan, Lai Hock; LaBell, Elizabeth Smith; Shen, Tong; DeBrota, David J

2014-12-01

The aim of this study was to assess the safety and tolerability, pharmacokinetics and pharmacodynamics of LY3000328 when administered as single escalating doses to healthy volunteers. This was a phase 1, placebo-controlled, dose escalation study with LY3000328 in 21 healthy male volunteers. Subjects were administered escalating LY3000328 doses up to 300 mg with food in this single dose study. Blood samples were collected at set times post-dose for the assessment of LY3000328 pharmacokinetics and the measurement of cathepsin S (CatS) activity, CatS mass and calculated CatS specific activity. All doses of LY3000328 were well tolerated, with linear pharmacokinetics up to the 300 mg dose. The pharmacodynamic activity of LY3000328 was measured ex vivo showing a biphasic response to LY3000328, where CatS activity declines, then returns to baseline, and then increases to a level above baseline. CatS mass was also assessed post-dose which increased in a dose-dependent manner, and continued to increase after LY3000328 had been cleared from the body. CatS specific activity was additionally calculated to normalize CatS activity for changes in CatS mass. This demonstrated the increase in CatS activity was attributable to the increase in CatS mass detected in plasma. A specific inhibitor of CatS which is cleared quickly from plasma may produce a transient decrease in plasma CatS activity which is followed by a more prolonged increase in plasma CatS mass which may have implications for the future clinical development of inhibitors of CatS. © 2014 The British Pharmacological Society.

Pharmacokinetics and pharmacodynamics of the cathepsin S inhibitor, LY3000328, in healthy subjects

PubMed Central

Payne, Christopher D; Deeg, Mark A; Chan, Melanie; Tan, Lai Hock; LaBell, Elizabeth Smith; Shen, Tong; DeBrota, David J

2014-01-01

Aim The aim of this study was to assess the safety and tolerability, pharmacokinetics and pharmacodynamics of LY3000328 when administered as single escalating doses to healthy volunteers. Methods This was a phase 1, placebo-controlled, dose escalation study with LY3000328 in 21 healthy male volunteers. Subjects were administered escalating LY3000328 doses up to 300 mg with food in this single dose study. Blood samples were collected at set times post-dose for the assessment of LY3000328 pharmacokinetics and the measurement of cathepsin S (CatS) activity, CatS mass and calculated CatS specific activity. Results All doses of LY3000328 were well tolerated, with linear pharmacokinetics up to the 300 mg dose. The pharmacodynamic activity of LY3000328 was measured ex vivo showing a biphasic response to LY3000328, where CatS activity declines, then returns to baseline, and then increases to a level above baseline. CatS mass was also assessed post-dose which increased in a dose-dependent manner, and continued to increase after LY3000328 had been cleared from the body. CatS specific activity was additionally calculated to normalize CatS activity for changes in CatS mass. This demonstrated the increase in CatS activity was attributable to the increase in CatS mass detected in plasma. Conclusion A specific inhibitor of CatS which is cleared quickly from plasma may produce a transient decrease in plasma CatS activity which is followed by a more prolonged increase in plasma CatS mass which may have implications for the future clinical development of inhibitors of CatS. PMID:25039273

A Faint Flux-limited Lyα Emitter Sample at z ˜ 0.3

NASA Astrophysics Data System (ADS)

Wold, Isak G. B.; Finkelstein, Steven L.; Barger, Amy J.; Cowie, Lennox L.; Rosenwasser, Benjamin

2017-10-01

We present a flux-limited sample of z ˜ 0.3 Lyα emitters (LAEs) from Galaxy Evolution Explorer (GALEX) grism spectroscopic data. The published GALEX z ˜ 0.3 LAE sample is pre-selected from continuum-bright objects and thus is biased against high equivalent width (EW) LAEs. We remove this continuum pre-selection and compute the EW distribution and the luminosity function of the Lyα emission line directly from our sample. We examine the evolution of these quantities from z ˜ 0.3 to 2.2 and find that the EW distribution shows little evidence for evolution over this redshift range. As shown by previous studies, the Lyα luminosity density from star-forming (SF) galaxies declines rapidly with declining redshift. However, we find that the decline in Lyα luminosity density from z = 2.2 to z = 0.3 may simply mirror the decline seen in the Hα luminosity density from z = 2.2 to z = 0.4, implying little change in the volumetric Lyα escape fraction. Finally, we show that the observed Lyα luminosity density from AGNs is comparable to the observed Lyα luminosity density from SF galaxies at z = 0.3. We suggest that this significant contribution from AGNs to the total observed Lyα luminosity density persists out to z ˜ 2.2. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Regulation of Akt and Wnt signaling by the group II metabotropic glutamate receptor antagonist LY341495 and agonist LY379268.

PubMed

Sutton, Laurie P; Rushlow, Walter J

2011-06-01

Metabotropic glutamate receptors 2/3 (mGlu(2/3)) have been implicated in schizophrenia and as a novel treatment target for schizophrenia. The current study examined whether mGlu(2/3) regulates Akt (protein kinase B) and Wnt (Wingless/Int-1) signaling, two cascades associated with schizophrenia and modified by antipsychotics. Western blotting revealed increases in phosphorylated Akt (pAkt) and phosphorylated glycogen synthase kinase-3 (pGSK-3) following acute and repeated treatment of LY379268 (mGlu(2/3) agonist), whereas increases in dishevelled-2 (Dvl-2), dishevelled-3 (Dvl-3), GSK-3 and β-catenin were only observed following repeated treatment. LY341495 (mGlu(2/3) antagonist) induced the opposite response compared with LY379268. Co-immunoprecipitation experiments showed an association between the mGlu(2/3) complex and Dvl-2 providing a possible mechanism to explain how the mGlu(2/3) can mediate changes in Wnt signaling. However, there was no association between the mGlu(2/3) complex and Akt suggesting that changes in Akt signaling following LY341495 and LY379268 treatments may not be directly mediated by the mGlu(2/3) . Finally, an increase in locomotor activity induced by LY341495 treatment correlated with increased pAkt and pGSK-3 levels and was attenuated by the administration of the GSK-3 inhibitor, SB216763. Overall, the results suggest that mGlu(2/3) regulates Akt and Wnt signaling and LY379268 treatment has overlapping effects with D(2) dopamine receptor antagonists (antipsychotic drugs). © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

Protection against amphetamine-induced neurotoxicity toward striatal dopamine neurons in rodents by LY274614, an excitatory amino acid antagonist.

PubMed

Fuller, R W; Hemrick-Luecke, S K; Ornstein, P L

1992-10-01

LY274614, 3SR,4aRS,6SR,8aRS-6-[phosphonomethyl]decahydr oisoquinoline-3- carboxylic acid, has been described as a potent antagonist of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor. Here its ability to antagonize the prolonged depletion of dopamine in the striatum by amphetamine in iprindole-treated rats is reported. A single 18.4 mg/kg (i.p.) dose of (+/-)-amphetamine hemisulfate, given to rats pretreated with iprindole, resulted in persistent depletion of dopamine in the striatum 1 week later. This prolonged depletion of dopamine in the striatum was antagonized by dizocilpine (MK-801, a non-competitive antagonist of NMDA receptors) or by LY274614 (a competitive antagonist of NMDA receptors). The protective effect of LY274614 was dose-dependent, being maximum at 10-40 mgkg (i.p.). A 10 mg/kg dose of LY274614 was effective in antagonizing the depletion of dopamine in the striatum, when given as long as 8 hr prior to amphetamine but not when given 24 hr prior to amphetamine. Depletion of dopamine in the striatum was also antagonized when LY274614 was given after the injection of amphetamine; LY274614 protected when given up to 4 hr after but not when given 8 or 24 hr after amphetamine. The prolonged depletion of dopamine in the striatum in mice, given multiple injections of methamphetamine, was also antagonized dose-dependently and completely by LY274614. The data strengthen the evidence that the neurotoxic effect of amphetamine and related compounds toward nigrostriatal dopamine neurons involves NMDA receptors and that LY274614 is an NMDA receptor antagonist with long-lasting in vivo effects in rats.

S100A8/A9 increases the mobilization of pro-inflammatory Ly6Chigh monocytes to the synovium during experimental osteoarthritis.

PubMed

Cremers, Niels A J; van den Bosch, Martijn H J; van Dalen, Stephanie; Di Ceglie, Irene; Ascone, Giuliana; van de Loo, Fons; Koenders, Marije; van der Kraan, Peter; Sloetjes, Annet; Vogl, Thomas; Roth, Johannes; Geven, Edwin J W; Blom, Arjen B; van Lent, Peter L E M

2017-09-29

Monocytes are dominant cells present within the inflamed synovium during osteoarthritis (OA). In mice, two functionally distinct monocyte subsets are described: pro-inflammatory Ly6C high and patrolling Ly6C low monocytes. Alarmins S100A8/A9 locally released by the synovium during inflammatory OA for prolonged periods may be dominant proteins involved in stimulating recruitment of Ly6C high monocytes from the circulation to the joint. Our objective was to investigate the role of S100A8/A9 in the mobilization of Ly6C high and Ly6C low monocytic populations to the inflamed joint in collagenase-induced OA (CiOA). S100A8 was injected intra-articularly to investigate monocyte influx. CiOA was induced by injection of collagenase into knee joints of wild-type C57BL/6 (WT), and S100a9 -/- mice. Mice were sacrificed together with age-matched saline-injected control mice (n = 6/group), and expression of monocyte markers, pro-inflammatory cytokines, and chemokines was determined in the synovium using ELISA and RT-qPCR. Cells were isolated from the bone marrow (BM), spleen, blood, and synovium and monocytes were identified using FACS. S100A8/A9 was highly expressed during CiOA. Intra-articular injection of S100A8 leads to elevated expression of monocyte markers and the monocyte-attracting chemokines CCL2 and CX3CL1 in the synovium. At day 7 (d7) after CiOA induction in WT mice, numbers of Ly6C high , but not Ly6C low monocytes, were strongly increased (7.6-fold) in the synovium compared to saline-injected controls. This coincided with strong upregulation of CCL2, which preferentially attracts Ly6C high monocytes. In contrast, S100a9 -/- mice showed a significant increase in Ly6C low monocytes (twofold) within the synovium at CiOA d7, whereas the number of Ly6C high monocytes remained unaffected. In agreement with this finding, the Ly6C low mobilization marker CX3CL1 was significantly higher within the synovium of S100a9 -/- mice. Next, we studied the effect of S100A8/A9 on release of Ly6C high monocytes from the BM into the circulation. A 14% decrease in myeloid cells was found in WT BM at CiOA d7. No decrease in myeloid cells in S100a9 -/- BM was found, suggesting that S100A8/A9 promotes the release of myeloid populations from the BM. Induction of OA locally leads to strongly elevated S100A8/A9 expression and an elevated influx of Ly6C high monocytes from the BM to the synovium.

Keck and VLT Observations of Super-Damped Lyman-Alpha Absorbers at z 2- 2.5: Constraints on Chemical Compositions and Physical Conditions

NASA Astrophysics Data System (ADS)

Kulkarni, Varsha P.; Som, Debopam; Morrison, Sean; Péroux, Celine; Quiret, Samuel; York, Donald G.

2015-12-01

We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Lyα quasar absorbers with H i column densities log NH i ≥ 21.7 at redshifts 2 ≲ z ≲ 2.5. All three absorbers show similar metallicities (˜-1.3 to -1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other damped Lyα a absorbers (DLAs) to examine trends between NH i, metallicity, and dust depletion. A larger fraction of the super-DLAs lie close to or above the line [X/H] = 20.59 - log NH i in the metallicity versus NH i plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230-0334 and Q0743+1421 do not cover H2 absorption lines. For Q1418+0718, some H2 lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log NH i < 21.7, we confirm strong correlation between metallicity and Fe depletion, and find a correlation between metallicity and Si depletion. For super-DLAs, these correlations are weaker or absent. The absorbers toward Q0230-0334 and Q1418+0718 show potential detections of weak Lyα emission, implying star formation rates of ˜1.6 and ˜0.7 M⊙ yr-1, respectively (ignoring dust extinction). Upper limits on the electron densities from C ii*/C ii or Si ii*/Si ii are low, but are higher than the median values in less gas-rich DLAs. Finally, systems with log NH i > 21.7 may have somewhat narrower velocity dispersions Δv90 than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas. Includes observations collected during program ESO 93.A-0422 at the European Southern Observatory (ESO) Very Large Telescope (VLT) with the Ultraviolet-Visual Echelle Spectrograph (UVES) on the 8.2 m telescopes operated at the Paranal Observatory, Chile. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Prediction of emission line fluxes of gravitationally lensed very high-z galaxies

NASA Astrophysics Data System (ADS)

Inoue, Akio; Shimizu, Ikkoh; Okamoto, Takashi; Yoshida, Naoki; Matsuo, Hiroshi; Tamura, Yoichi

2015-08-01

Spectroscopic confirmation of very high-z galaxy candidates is extremely valuable because this is a direct proof of the existence of galaxies in the early Universe and put a strong constraint on the structure formation theory to produce such galaxies during the limited age of the Universe. Before the completion of the cosmic reionization, hydrogen Ly-alpha emission line is hard to be observed and we need other emission lines to confirm the redshift of galaxies. By using a state-of-the-art cosmological hydrodynamics simulation of galaxy formation and evolution with an emission line model based on Cloudy, we predict the line fluxes of some gravitationally-lensed very high-z galaxy candidates. We also discuss their detectability with the current and future telescopes.

A study of ten quasars with redshifts greater than four

NASA Technical Reports Server (NTRS)

Schneider, Donald P.; Schmidt, Maarten; Gunn, James E.

1989-01-01

Four quasars with redshifts greater than four were detected in a low-resolution CCD grism survey. CCD photometry and high S/N, moderate resolution spectra are presented for these quasars and the six other known quasars with redshifts above 4. The M sub B values of nine of the objects are between -27.5 and -25, with the tenth quasar having an M sub B value of -29. The emission lines and shapes of the continua of these ten quasars are similar to those of lower-redshift quasars. The results suggest that the C IV emission lines in high-redshift quasars may be weaker than those in lower-redshift quasars. The continua of all of the high-redshift quasars display strong depressions blueward of the Ly-alpha emission line.

Observations of the interstellar gas with the Copernicus satellite

NASA Technical Reports Server (NTRS)

Morton, D. C.

1975-01-01

Results are reviewed for Copernicus far-UV measurements of the absorption lines of H I, D I, H2, and heavier elements in the interstellar gas. Column densities along several lines of sight, as estimated from Ly-alpha absorption-line profiles, confirm that wide differences in the gas density are present in various directions. The measurement of interstellar D I implies an open universe unless alternate sources for this nuclide are found. Analysis of reddened stars for which the line of sight passes through one or more interstellar clouds indicates a depletion of several heavy elements in the gas. It is suggested that the depleted elements may be present in grains rather than molecules and that the intercloud medium may consist primarily of H II with a few small H I clouds.

IUE spectrophotometry of the DA4 primary in the short-period white dwarf-red dwarf spectroscopic binary Case 1

NASA Technical Reports Server (NTRS)

Sion, E. M.; Guinan, E. F.; Wesemael, F.

1984-01-01

Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha red wing yields T(e) = 13,000 + or - 500 K. Possible interpretations of the 1400 A feature are reviewed. Case 1 is the coolest white dwarf found in a short-period, detached white dwarf-red dwarf binary, and its cooling time is consistent with estimates of the efficiency of angular momentum removal mechanisms in the phases subsequent to common envelope binary evolution.

Combined antibacterial activity of phage lytic proteins holin and lysin from Streptococcus suis bacteriophage SMP.

PubMed

Shi, Yibo; Li, Ning; Yan, Yaxian; Wang, Hengan; Li, Yan; Lu, Chengping; Sun, Jianhe

2012-07-01

Development of novel antibacterial agents is required to control infection with multidrug-resistant Streptococcus suis. HolSMP and LySMP, the holin and lysin of S. suis serotype 2 bacteriophage, named SMP, are responsible for lysis of host cells and release of progeny phage. HolSMP and LySMP expressed in Escherichia coli BL21(DE3) exerted efficient activity at 37 °C, pH 5.2, with addition of 0.8 % β-mercaptoethanol. Lytic spectra of purified HolSMP, LySMP or HolSMP + LySMP mixture were investigated. HolSMP, exhibiting a narrow lytic spectrum, was effective against Staphylococcus aureus and Bacillus subtilis, which were insensitive to LySMP. Moreover, HolSMP was identified as a promising antibacterial agent which was able to extend the spectrum of LySMP. The data suggest that combined use of holin and lysin could be a candidate strategy for resolution of drug resistance.

Lyman continuum leaking AGN in the SSA22 field

NASA Astrophysics Data System (ADS)

Micheva, Genoveva; Iwata, Ikuru; Inoue, Akio K.

2017-02-01

Subaru/SuprimeCam narrow-band photometry of the SSA22 field reveals the presence of four Lyman continuum (LyC) candidates among a sample of 14 active galactic nuclei (AGNs). Two show offsets and likely have stellar LyCin nature or are foreground contaminants. The remaining two LyC candidates are type I AGN. We argue that the average LyC escape fraction of high-redshift, low-luminosity AGN is not likely to be unity, as often assumed in the literature. From direct measurement we obtain the average LyC-to-UV flux density ratio and ionizing emissivity for a number of AGN classes and find it at least a factor of 2 lower than values obtained assuming fesc = 1. Comparing to recent Ly α forest measurements, AGNs at redshift z ˜ 3 make up at most ˜12 per cent and as little as ˜5 per cent of the total ionizing budget. Our results suggest that AGNs are unlikely to dominate the ionization budget of the Universe at high redshifts.

A long-term, phase 2, multicenter, randomized, open-label, comparative safety study of pomaglumetad methionil (LY2140023 monohydrate) versus atypical antipsychotic standard of care in patients with schizophrenia

PubMed Central

2013-01-01

Background We compared the time to discontinuation due to lack of tolerability over 24 weeks in patients suffering from schizophrenia treated with pomaglumetad methionil (LY2140023 monohydrate, the prodrug of metabotropic glutamate 2/3 receptor agonist, LY404039) or standard of care (SOC: olanzapine, risperidone, or aripiprazole). Methods Study HBBR was a multicenter, randomized, open-label study comparing the long-term safety and tolerability of LY2140023 with SOC for schizophrenia. Patients had moderate symptomatology with prominent negative symptoms and evidence of functional impairment. Those who met entry criteria were randomized to open-label treatment with either LY2140023 (target dose: 40 mg twice daily [BID]; n = 130) or SOC (n = 131). Results There was no statistically significant difference between LY2140023 and SOC for time to discontinuation due to lack of tolerability (primary objective; P = .184). The Kaplan-Meier estimates revealed comparable time to event profiles. Only 27% of LY2140023 and 45% of SOC patients completed the 24-week open-label, active treatment phase. Twenty-seven patients (20.8%) in the LY2140023 group and 15 patients (11.5%) in the SOC group discontinued due to lack of efficacy (P = .044). Twenty-three patients (17.7%) in the LY2140023 group and 19 patients (14.5%) in the SOC group discontinued due to adverse events (physician and subject decision combined, P = .505). The incidence of serious adverse events was comparable between groups. LY2140023-treated patients reported significantly more treatment-emergent adverse events of vomiting, agitation, and dyspepsia, while SOC-treated patients reported significantly more akathisia and weight gain. The incidence of treatment-emergent parkinsonism (P = .011) and akathisia (P = .029) was significantly greater in SOC group. Improvement in PANSS total score over the initial 6 to 8 weeks of treatment was similar between groups, but improvement was significantly greater in the SOC group at 24-week endpoint (P = .004). LY2140023 and SOC groups had comparable negative symptom improvement at 24-week endpoint (P = .444). Conclusion These data provide further evidence that the potential antipsychotic LY2140023 monohydrate, with a glutamatergic mechanism of action, may have a unique tolerability profile characterized by a low association with some adverse events such as extrapyramidal symptoms and weight gain that may characterize currently available dopaminergic antipsychotics. Trials registration A Long-term, Phase 2, Multicenter, Randomized, Open-label, Comparative Safety Study of LY2140023 Versus Atypical Antipsychotic Standard of Care in Patients with DSM-IV-TR Schizophrenia ClinicalTrials.gov identifier: NCT00845026. PMID:23694720

Biometric assessment of prostate cancer's metastatic potential.

PubMed

Cooper, C R; Emmett, N; Harris-Hooker, S; Patterson, R; Cooke, D B

1994-01-01

Currently, no protocol exists that can assess the metastatic potential of prostate adenocarcinoma. The reason for this is partly due to the lack of information on cellular changes that result in a tumor cell's becoming metastatic. In this investigation, attempts were made to devise a method that correlated with the metastatic potential of AT-1, Mat-Lu, and Mat-LyLu cell lines of the Dunning R-3327 rat prostatic adenocarcinoma system. To accomplish this, we applied BioQuant biometric parameters, i.e., area, shape factor, and cell motility. AT-1 had a lower shape factor and a greater area as compared with the more highly metastatic Mat-Lu subline. No significant difference in area or shape factor was detected between the AT-1 cell line and the highly metastatic Mat-LyLu line. However, the lowly metastatic AT-1 line had less motility as compared with the Mat-Lu and Mat-LyLu lines. This study revealed that metastatic potential could be partially predicted via area and shape factor and accurately predicted via cell motility.

Influence of stellar radiation pressure on flow structure in the envelope of hot-Jupiter HD 209458b

NASA Astrophysics Data System (ADS)

Cherenkov, A. A.; Bisikalo, D. V.; Kosovichev, A. G.

2018-03-01

Close-in exoplanets are subjected to extreme radiation of their host stars. Photometric observations of the hot-Jupiter HD 209458b transit by HST/STIS detected strong absorption in the Ly α line, thus indicating the existence of a hydrogen envelope extending beyond the Roche lobe. The gasdynamic modelling (Bisikalo et al.) showed that the stable structure of this envelope is maintained by the balance between the Roche lobe overfilling and stellar wind pressure. Obviously, the dynamics and stability of the envelope can be affected by stellar radiation pressure. Using 3D gasdynamic simulations, we study the impact of radiation pressure in the Ly α line on the envelope of hot-Jupiter HD 209458b, and show that the effect is not strong enough to significantly affect the gasdynamics in the system. For a detectable radiation pressure effect the intensity of the Ly α line has to be by two orders of magnitude greater.

Inspiraling halo accretion mapped in Ly α emission around a z ˜ 3 quasar

NASA Astrophysics Data System (ADS)

Arrigoni Battaia, Fabrizio; Prochaska, J. Xavier; Hennawi, Joseph F.; Obreja, Aura; Buck, Tobias; Cantalupo, Sebastiano; Dutton, Aaron A.; Macciò, Andrea V.

2018-01-01

In an effort to search for Ly α emission from circum- and intergalactic gas on scales of hundreds of kpc around z ∼ 3 quasars, and thus characterize the physical properties of the gas in emission, we have initiated an extensive fast survey with the Multi-Unit Spectroscopic Explorer (MUSE): Quasar Snapshot Observations with MUse: Search for Extended Ultraviolet eMission (QSO MUSEUM). In this work, we report the discovery of an enormous Ly α nebula (ELAN) around the quasar SDSS J102009.99+104002.7 at z = 3.164, which we followed-up with deeper MUSE observations. This ELAN spans ∼297 projected kpc, has an average Ly α surface brightness SBLy α ∼ 6.04 × 10-18 erg s-1 cm-2 arcsec-2(within the 2σ isophote) and is associated with an additional four previously unknown embedded sources: two Ly α emitters and two faint active galactic nuclei (one type-1 and one type-2 quasar). By mapping at high significance, the line-of-sight velocity in the entirety of the observed structure, we unveiled a large-scale coherent rotation-like pattern spanning ∼300 km s-1 with a velocity dispersion of <270 km s-1, which we interpret as a signature of the inspiraling accretion of substructures within the quasar's host halo. Future multiwavelength data will complement our MUSE observations and are definitely needed to fully characterize such a complex system. None the less, our observations reveal the potential of new sensitive integral-field spectrographs to characterize the dynamical state of diffuse gas on large scales in the young Universe, and thereby witness the assembly of galaxies.

Plasticity of Myeloid Cells during Oral Barrier Wound Healing and the Development of Bisphosphonate-related Osteonecrosis of the Jaw.

PubMed

Sun, Yujie; Kaur, Kawaljit; Kanayama, Keiichi; Morinaga, Kenzo; Park, Sil; Hokugo, Akishige; Kozlowska, Anna; McBride, William H; Li, Jun; Jewett, Anahid; Nishimura, Ichiro

2016-09-23

Injury to the barrier tissue initiates a rapid distribution of myeloid immune cells from bone marrow, which guide sound wound healing. Bisphosphonates, a widely used anti-bone resorptive drug with minimal systemic side effects, have been linked to an abnormal wound healing in the oral barrier tissue leading to, in some cases, osteonecrosis of the jaw (ONJ). Here we report that the development of ONJ may involve abnormal phenotypic plasticity of Ly6G+/Gr1+ myeloid cells in the oral barrier tissue undergoing tooth extraction wound healing. A bolus intravenous zoledronate (ZOL) injection to female C57Bl/6 mice followed by maxillary first molar extraction resulted in the development of ONJ-like lesion during the second week of wound healing. The multiplex assay of dissociated oral barrier cells exhibited the secretion of cytokines and chemokines, which was significantly modulated in ZOL mice. Tooth extraction-induced distribution of Ly6G+/Gr1+ cells in the oral barrier tissue increased in ZOL mice at week 2. ONJ-like lesion in ZOL mice contained Ly6G+/Gr1+ cells with abnormal size and morphology as well as different flow cytometric staining intensity. When anti-Ly6G (Gr1) antibody was intraperitoneally injected for 5 days during the second week of tooth extraction, CD11b+GR1(hi) cells in bone marrow and Ly6G+ cells in the oral barrier tissue were depleted, and the development of ONJ-like lesion was significantly attenuated. This study suggests that local modulation of myeloid cell plasticity in the oral barrier tissue may provide the basis for pathogenesis and thus therapeutic as well as preventive strategy of ONJ. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Kinematics and Optical Depth in the Green Peas: Suppressed Superwinds in Candidate LyC Emitters

NASA Astrophysics Data System (ADS)

Jaskot, Anne E.; Oey, M. S.; Scarlata, Claudia; Dowd, Tara

2017-12-01

By clearing neutral gas away from a young starburst, superwinds may regulate the escape of Lyman continuum (LyC) photons from star-forming galaxies. However, models predict that superwinds may not launch in the most extreme, compact starbursts. We explore the role of outflows in generating low optical depths in the Green Peas (GPs), the only known star-forming population with several confirmed and candidate LyC-leaking galaxies. With Hubble Space Telescope UV spectra of 25 low-redshift GPs, including new observations of 13 of the most highly ionized GPs, we compare the kinematics of UV absorption lines with indirect H I optical depth diagnostics: Lyα escape fraction, Lyα peak separation, or low-ionization absorption line equivalent width. The data suggest that high-ionization kinematics tracing superwind activity may correlate with low optical depth in some objects. However, the most extreme GPs, including many of the best candidate LyC emitters with weak low-ionization absorption and strong, narrow Lyα profiles, show the lowest velocities. These results are consistent with models for suppressed superwinds, which suggests that outflows may not be the only cause of LyC escape from galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS-5-26555. These observations are associated with programs GO-14080, GO-13293, and GO-12928.

Specific depletion of Ly6C(hi) inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

PubMed

Schumak, Beatrix; Klocke, Katrin; Kuepper, Janina M; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6C(hi) inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi) inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi) inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

Specific Depletion of Ly6Chi Inflammatory Monocytes Prevents Immunopathology in Experimental Cerebral Malaria

PubMed Central

Kuepper, Janina M.; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes. PMID:25884830

Acetylcholine-producing NK cells attenuate CNS inflammation via modulation of infiltrating monocytes/macrophages.

PubMed

Jiang, Wei; Li, Daojing; Han, Ranran; Zhang, Chao; Jin, Wei-Na; Wood, Kristofer; Liu, Qiang; Shi, Fu-Dong; Hao, Junwei

2017-07-25

The nonneural cholinergic system of immune cells is pivotal for the maintenance of immunological homeostasis. Here we demonstrate the expression of choline acetyltransferase (ChAT) and cholinergic enzymes in murine natural killer (NK) cells. The capacity for acetylcholine synthesis by NK cells increased markedly under inflammatory conditions such as experimental autoimmune encephalomyelitis (EAE), in which ChAT expression escalated along with the maturation of NK cells. ChAT + and ChAT - NK cells displayed distinctive features in terms of cytotoxicity and chemokine/cytokine production. Transfer of ChAT + NK cells into the cerebral ventricles of CX3CR1 -/- mice reduced brain and spinal cord damage after EAE induction, and decreased the numbers of CNS-infiltrating CCR2 + Ly6C hi monocytes. ChAT + NK cells killed CCR2 + Ly6C hi monocytes directly via the disruption of tolerance and inhibited the production of proinflammatory cytokines. Interestingly, ChAT + NK cells and CCR2 + Ly6C hi monocytes formed immune synapses; moreover, the impact of ChAT + NK cells was mediated by α7-nicotinic acetylcholine receptors. Finally, the NK cell cholinergic system up-regulated in response to autoimmune activation in multiple sclerosis, perhaps reflecting the severity of disease. Therefore, this study extends our understanding of the nonneural cholinergic system and the protective immune effect of acetylcholine-producing NK cells in autoimmune diseases.

High-resolution ultraviolet radiation fields of classical T Tauri stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

France, Kevin; Schindhelm, Eric; Bergin, Edwin A.

2014-04-01

The far-ultraviolet (FUV; 912-1700 Å) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r < 10 AU), from a gas- and dust-rich primordial disk to a transitional system where the optically thick warm dust distribution has been depleted. Previous efforts to measure the true stellar+accretion-generated FUV luminosity (both hot gas emission lines and continua) have been complicated by a combination of low-sensitivity and/or low-spectral resolution and did not includemore » the contribution from the bright Lyα emission line. In this work, we present a high-resolution spectroscopic study of the FUV radiation fields of 16 T Tauri stars whose dust disks display a range of evolutionary states. We include reconstructed Lyα line profiles and remove atomic and molecular disk emission (from H{sub 2} and CO fluorescence) to provide robust measurements of both the FUV continuum and hot gas lines (e.g., Lyα, N V, C IV, He II) for an appreciable sample of T Tauri stars for the first time. We find that the flux of the typical classical T Tauri star FUV radiation field at 1 AU from the central star is ∼10{sup 7} times the average interstellar radiation field. The Lyα emission line contributes an average of 88% of the total FUV flux, with the FUV continuum accounting for an average of 8%. Both the FUV continuum and Lyα flux are strongly correlated with C IV flux, suggesting that accretion processes dominate the production of both of these components. On average, only ∼0.5% of the total FUV flux is emitted between the Lyman limit (912 Å) and the H{sub 2} (0-0) absorption band at 1110 Å. The total and component-level high-resolution radiation fields are made publicly available in machine-readable format.« less

Coding variants in PNPLA3 and TM6SF2 are risk factors for hepatic steatosis and elevated serum alanine aminotransferases caused by a glucagon receptor antagonist

PubMed Central

Guzman, Cristina B.; Duvvuru, Suman; Akkari, Anthony; Bhatnagar, Pallav; Battioui, Chakib; Foster, Wendra; Zhang, Xiaotian Michelle; Shankar, Sudha S.; Deeg, Mark A.; Hardy, Thomas A.; Kazda, Christof M.

2018-01-01

LY2409021 is a glucagon receptor antagonist that was associated with hepatic steatosis and elevated aminotransferases in phase 2 diabetes studies. We investigated the relationship between selected genetic variants and hepatic steatosis and elevated alanine aminotransferases (ALTs) associated with LY2409021. Patients participated in a 6‐week placebo‐controlled trial (I1R‐MC‐GLDI [GLDI], n = 246) and a 52‐week placebo‐ and active comparator‐controlled trial (I1R‐MC‐GLDJ [GLDJ], n = 158). GLDJ had endpoints at 6 months, including measures of hepatic fat fraction (HFF) by magnetic resonance imaging. The five genes tested were patatin‐like phospholipase domain containing 3 (PNPLA3) (rs738409 and rs738491), transmembrane 6 superfamily member 2 (TM6SF2) (rs58542926), peroxisome proliferative activated receptor gamma coactivator 1 alpha (PPARGC1A) (rs4361373, rs3774921, rs2970849), adenylate cyclase 3 (ADCY3) (rs713586), and insulin‐like growth factor 1 (IGF‐1) (rs1520220). In GLDI, PNPLA3 I148M (P = 0.001) and TM6SF2 E167K (P = 0.001) were significantly associated with an increase in ALT at 6 weeks for LY2409021 but not for placebo. In GLDJ, PNPLA3 I148M showed the same effect (P = 0.007) on ALT at 6 months but the placebo or sitagliptin did not. In GLDJ, both PNPLA3 and TM6SF2 risk‐allele carriers showed increases in HFF that were numerically greater but not statistically significant. The carriers of PNPLA3 and/or TM6SF2 risk alleles showed significantly increased ALT (GLDI, +13.28 U/L in carriers versus +4.84 U/L in noncarriers, P = 4 × 10–5; GLDJ, +14.6 U/L in carriers versus +1.7 in noncarriers, P = 0.0018) and HFF (GLDJ, +5.35% in carriers versus 2.38% in noncarriers, P = 0.048). Elevation of transaminase and HFF were also noted in the noncarriers but at a significantly lower degree. Conclusion: The carriers of PNPLA3 and/or TM6SF2 variant alleles are at risk for hepatic steatosis and elevated ALT levels caused by LY2409021, a glucagon receptor antagonist. More studies are needed to investigate if our observations are generalizable to hepatic steatosis caused by other medications. (Hepatology Communications 2018;2:561‐570) PMID:29761171

Coding variants in PNPLA3 and TM6SF2 are risk factors for hepatic steatosis and elevated serum alanine aminotransferases caused by a glucagon receptor antagonist.

PubMed

Guzman, Cristina B; Duvvuru, Suman; Akkari, Anthony; Bhatnagar, Pallav; Battioui, Chakib; Foster, Wendra; Zhang, Xiaotian Michelle; Shankar, Sudha S; Deeg, Mark A; Chalasani, Naga; Hardy, Thomas A; Kazda, Christof M; Pillai, Sreekumar G

2018-05-01

LY2409021 is a glucagon receptor antagonist that was associated with hepatic steatosis and elevated aminotransferases in phase 2 diabetes studies. We investigated the relationship between selected genetic variants and hepatic steatosis and elevated alanine aminotransferases (ALTs) associated with LY2409021. Patients participated in a 6-week placebo-controlled trial (I1R-MC-GLDI [GLDI], n = 246) and a 52-week placebo- and active comparator-controlled trial (I1R-MC-GLDJ [GLDJ], n = 158). GLDJ had endpoints at 6 months, including measures of hepatic fat fraction (HFF) by magnetic resonance imaging. The five genes tested were patatin-like phospholipase domain containing 3 ( PNPLA3 ) (rs738409 and rs738491), transmembrane 6 superfamily member 2 ( TM6SF2 ) (rs58542926), peroxisome proliferative activated receptor gamma coactivator 1 alpha ( PPARGC1A ) (rs4361373, rs3774921, rs2970849), adenylate cyclase 3 ( ADCY3 ) ( rs713586), and insulin-like growth factor 1 ( IGF-1 ) (rs1520220). In GLDI, PNPLA3 I148M ( P = 0.001) and TM6SF2 E167K ( P = 0.001) were significantly associated with an increase in ALT at 6 weeks for LY2409021 but not for placebo. In GLDJ, PNPLA3 I148M showed the same effect ( P = 0.007) on ALT at 6 months but the placebo or sitagliptin did not. In GLDJ, both PNPLA3 and TM6SF2 risk-allele carriers showed increases in HFF that were numerically greater but not statistically significant. The carriers of PNPLA3 and/or TM6SF2 risk alleles showed significantly increased ALT (GLDI, +13.28 U/L in carriers versus +4.84 U/L in noncarriers, P = 4 × 10 -5 ; GLDJ, +14.6 U/L in carriers versus +1.7 in noncarriers, P = 0.0018) and HFF (GLDJ, +5.35% in carriers versus 2.38% in noncarriers, P = 0.048). Elevation of transaminase and HFF were also noted in the noncarriers but at a significantly lower degree. Conclusion: The carriers of PNPLA3 and/or TM6SF2 variant alleles are at risk for hepatic steatosis and elevated ALT levels caused by LY2409021, a glucagon receptor antagonist. More studies are needed to investigate if our observations are generalizable to hepatic steatosis caused by other medications. ( Hepatology Communications 2018;2:561-570).

Antagonism of mGlu2/3 receptors in the nucleus accumbens prevents oxytocin from reducing cued methamphetamine seeking in male and female rats.

PubMed

Bernheim, Aurelien; Leong, Kah-Chung; Berini, Carole; Reichel, Carmela M

2017-10-01

Methamphetamine (meth) addiction is a prevalent health concern worldwide, yet remains without approved pharmacological treatments. Preclinical evidence suggests that oxytocin may decrease relapse, but the neuronal underpinnings driving this effect remain unknown. Here we investigate whether oxytocin's effect is dependent on presynaptic glutamatergic regulation in the nucleus accumbens core (NAcore) by blocking metabotropic glutamate receptors 2/3 (mGluR2/3). Male and female Sprague-Dawley rats self-administered meth or sucrose on an escalating fixed ratio, followed by extinction and cue-induced reinstatement sessions. Reinstatement tests consisted of systemic (Experiment 1) or site-specific application of the drugs into the NAcore (Experiments 2 and 3). Before reinstatement sessions, rats received LY341495, an mGluR2/3 antagonist, or its vehicle followed by a second infusion/injection of oxytocin or saline. As expected, both males and females reinstated lever pressing to meth associated cues, and LY341495 alone did not impact this behavior. Oxytocin injected systemically or infused into the NAcore decreased cued meth seeking. Importantly, combined LY341495 and oxytocin administration restored meth cued reinstatement. Interestingly, neither oxytocin nor LY341495 impacted sucrose-cued reinstatement, suggesting distinct mechanisms between meth and sucrose. These findings were consistent between males and females. Overall, we report that oxytocin reduced responding to meth-associated cues and blocking presynaptic mGluR2/3 reversed this effect. Further, oxytocin's effects were specific to meth cues as NAcore oxytocin was without an effect on sucrose cued reinstatement. Results are discussed in terms of oxytocin receptor localization in the NAcore and modulation of presynaptic regulation of glutamate in response to drug associated cues. Copyright © 2017 Elsevier Inc. All rights reserved.

Probing the Intergalactic Medium with Ly α and 21 cm Fluctuations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heneka, Caroline; Cooray, Asantha; Feng, Chang

2017-10-10

We study 21 cm and Ly α fluctuations, as well as H α , while distinguishing between Ly α emission of galactic, diffuse, and scattered intergalactic medium (IGM) origin. Cross-correlation information about the state of the IGM is obtained, testing neutral versus ionized medium cases with different tracers in a seminumerical simulation setup. In order to pave the way toward constraints on reionization history and modeling beyond power spectrum information, we explore parameter dependencies of the cross-power signal between 21 cm and Ly α , which displays a characteristic morphology and a turnover from negative to positive correlation at scalesmore » of a couple Mpc{sup −1}. In a proof of concept for the extraction of further information on the state of the IGM using different tracers, we demonstrate the use of the 21 cm and H α cross-correlation signal to determine the relative strength of galactic and IGM emission in Ly α . We conclude by showing the detectability of the 21 cm and Ly α cross-correlation signal over more than one decade in scale at high signal-to-noise ratio for upcoming probes like SKA and the proposed all-sky intensity mapping satellites SPHEREx and CDIM, while also including the Ly α damping tail and 21 cm foreground avoidance in the modeling.« less

Photometric followup investigations on LAMOST survey target Ly And

NASA Astrophysics Data System (ADS)

Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Pi, Qing-feng; Wang, Dai-mei

2017-02-01

We present a low-dispersion spectrum and two sets of CCD photometric light curves of the eclipsing binary LY And for the first time. The spectrum of LY And was classified as G2. We derived an updated ephemeris based on all previously available and our newly acquired minimum light times. Our analyses of LY And light curve minimum times reveals that the differences between calculated and observed minimum times for LY And can be represented by an upward parabolic curve, which means its orbital period is increasing with a rate of 1.88 (± 0.13) × 10-7 days/year. This increase in orbital period may be interpreted as mass transfer from the primary component to the secondary component, with a rate of dM1/dt = -4.54 × 10-8M⊙/year. By analyzing our CCD photometric light curves obtained in 2015, we obtained its photometric solution with the Wilson-Devinney program. This photometric solution also fits very well our light curves obtained in 2014. Our photometric solution shows that LY And is a contact eclipsing binary and its contact factor is f = (17.8 ± 1.9)%. Furthermore, both our spectroscopic and photometric data show no obvious chromospheric activity of LY And.

The putative endocannabinoid transport blocker LY2183240 is a potent inhibitor of FAAH and several other brain serine hydrolases.

PubMed

Alexander, Jessica P; Cravatt, Benjamin F

2006-08-02

How lipid transmitters move within and between cells to communicate signals remains an important and largely unanswered question. Integral membrane transporters, soluble lipid-binding proteins, and metabolic enzymes have all been proposed to collaboratively regulate lipid signaling dynamics in vivo. Assignment of the relative contributions made by each of these classes of proteins requires selective pharmacological agents to perturb their individual functions. Recently, LY2183240, a heterocyclic urea inhibitor of the putative endocannabinoid (EC) transporter, was shown to disrupt the cellular uptake of the lipid EC anandamide and promote analgesia in vivo. Here, we show that LY2183240 is a potent, covalent inhibitor of the EC-degrading enzyme fatty acid amide hydrolase (FAAH). LY2183240 inactivates FAAH by carbamylation of the enzyme's serine nucleophile. More global screens using activity-based proteomic probes identified several additional serine hydrolases that are also inhibited by LY2183240. These results indicate that the blockade of anandamide uptake observed with LY2183240 may be due primarily to the inactivation of FAAH, providing further evidence that this enzyme serves as a metabolic driving force that promotes the diffusion of anandamide into cells. More generally, the proteome-wide target promiscuity of LY2183240 designates the heterocyclic urea as a chemotype with potentially excessive protein reactivity for drug design.

Proof-of-Concept Study to Assess the Nociceptin Receptor Antagonist LY2940094 as a New Treatment for Alcohol Dependence.

PubMed

Post, Anke; Smart, Trevor S; Jackson, Kimberley; Mann, Joanne; Mohs, Richard; Rorick-Kehn, Linda; Statnick, Michael; Anton, Raymond; O'Malley, Stephanie S; Wong, Conrad J

2016-09-01

This was a proof-of-concept study to evaluate the efficacy of LY2940094, a nociceptin/orphanin FQ peptide receptor antagonist, in reducing alcohol consumption in actively alcohol-drinking patients with alcohol dependence. Eighty-eight patients, 21 to 66 years of age, diagnosed with alcohol dependence, reporting 3 to 6 heavy drinking days per week, were randomized (1:1) to 8 weeks of treatment with once-daily oral placebo (N = 44) or 40 mg/d of LY2940094 (N = 44). The primary efficacy analysis was the change from baseline in number of drinks per day (NDD) utilizing mixed-model repeated measures comparing LY2940094 and placebo in Month 2 of the 8-week double-blind treatment period. The probability that the difference relative to placebo in NDD was ≤0 at endpoint was calculated, and a probability ≥80% was considered to be evidence that LY2940094 was associated with the reduction in NDD. After 8 weeks of treatment, reduction in mean NDD did not differ between LY2940094 versus placebo (-1.4 vs. -1.5, respectively, 44% probability of greater reduction relative to placebo), but there was a greater reduction in the mean percentage of heavy drinking days in a month with LY2940094 versus placebo (-24.5 vs. -15.7%, respectively, 93% probability of a greater reduction relative to placebo), and an increase in the mean percentage of abstinent days in a month compared to placebo (9.1 vs. 1.9%, respectively, 91% probability of a greater increase relative to placebo). Patients who were treated with LY2940094 showed decreased plasma levels of gamma-glutamyl transferase with probabilities ≥98% for greater reduction compared with placebo at Weeks 1, 4, 6, and 8. Treatment-emergent adverse events in ≥5% of patients treated with LY2940094 included insomnia, vomiting, and anxiety. There were no serious adverse events or significant changes in laboratory assessments or vital signs with LY2940094. Although not reducing the NDD, LY2940094, compared to placebo, did reduce heavy drinking days and increased abstinence days in patients with alcohol dependence. Copyright © 2016 by the Research Society on Alcoholism.

Influence of Lymphatic Invasion on Locoregional Recurrence Following Mastectomy: Indication for Postmastectomy Radiotherapy for Breast Cancer Patients With One to Three Positive Nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsunuma, Ryoichi, E-mail: r-matsunuma@nifty.com; First Department of Surgery, Hamamatsu University School of Medicine, Shizuoka; Oguchi, Masahiko

2012-07-01

Purpose: The indication for postmastectomy radiotherapy (PMRT) in breast cancer patients with one to three positive lymph nodes has been in discussion. The purpose of this study was to identify patient groups for whom PMRT may be indicated, focusing on varied locoregional recurrence rates depending on lymphatic invasion (ly) status. Methods and Materials: Retrospective analysis of 1,994 node-positive patients who had undergone mastectomy without postoperative radiotherapy between January 1990 and December 2000 at our hospital was performed. Patient groups for whom PMRT should be indicated were assessed using statistical tests based on the relationship between locoregional recurrence rate and lymore » status. Results: Multivariate analysis showed that the ly status affected the locoregional recurrence rate to as great a degree as the number of positive lymph nodes (p < 0.001). Especially for patients with one to three positive nodes, extensive ly was a more significant factor than stage T3 in the TNM staging system for locoregional recurrence (p < 0.001 vs. p = 0.295). Conclusion: Among postmastectomy patients with one to three positive lymph nodes, patients with extensive ly seem to require local therapy regimens similar to those used for patients with four or more positive nodes and also seem to require consideration of the use of PMRT.« less

New constraints on the average escape fraction of Lyman continuum radiation in z 4 galaxies from the VIMOS Ultra Deep Survey (VUDS)

NASA Astrophysics Data System (ADS)

Marchi, F.; Pentericci, L.; Guaita, L.; Ribeiro, B.; Castellano, M.; Schaerer, D.; Hathi, N. P.; Lemaux, B. C.; Grazian, A.; Le Fèvre, O.; Garilli, B.; Maccagni, D.; Amorin, R.; Bardelli, S.; Cassata, P.; Fontana, A.; Koekemoer, A. M.; Le Brun, V.; Tasca, L. A. M.; Thomas, R.; Vanzella, E.; Zamorani, G.; Zucca, E.

2017-05-01

Context. Determining the average fraction of Lyman continuum (LyC) photons escaping high redshift galaxies is essential for understanding how reionization proceeded in the z> 6 Universe. Aims: We want to measure the LyC signal from a sample of sources in the Chandra Deep Field South (CDFS) and COSMOS fields for which ultra-deep VIMOS spectroscopy as well as multi-wavelength Hubble Space Telescope (HST) imaging are available. Methods: We select a sample of 46 galaxies at z 4 from the VIMOS Ultra Deep Survey (VUDS) database, such that the VUDS spectra contain the LyC part, that is, the rest-frame range 880-910 Å. Taking advantage of the HST imaging, we apply a careful cleaning procedure and reject all the sources showing nearby clumps with different colours, that could potentially be lower-redshift interlopers. After this procedure, the sample is reduced to 33 galaxies. We measure the ratio between ionizing flux (LyC at 895 Å) and non-ionizing emission (at 1500 Å) for all individual sources. We also produce a normalized stacked spectrum of all sources. Results: Assuming an intrinsic average Lν(1470) /Lν(895) of 3, we estimate the individual and average relative escape fraction. We do not detect ionizing radiation from any individual source, although we identify a possible LyC emitter with very high Lyα equivalent width (EW). From the stacked spectrum and assuming a mean transmissivity for the sample, we measure a relative escape fraction . We also look for correlations between the limits in the LyC flux and source properties and find a tentative correlation between LyC flux and the EW of the Lyα emission line. Conclusions: Our results imply that the LyC flux emitted by V = 25-26 star-forming galaxies at z 4 is at most very modest, in agreement with previous upper limits from studies based on broad and narrow band imaging. Based on data obtained with the European Southern Observatory Very Large Telescope, Paranal, Chile, under Large Program 185.A-0791.

SHARDS Frontier Fields: Physical Properties of a Low-mass Lyα Emitter at z = 5.75

NASA Astrophysics Data System (ADS)

Hernán-Caballero, Antonio; Pérez-González, Pablo G.; Diego, Jose M.; Lagattuta, David; Richard, Johan; Schaerer, Daniel; Alonso-Herrero, Almudena; Marino, Raffaella Anna; Sklias, Panos; Alcalde Pampliega, Belén; Cava, Antonio; Conselice, Christopher J.; Dannerbauer, Helmut; Domínguez-Sánchez, Helena; Eliche-Moral, Carmen; Esquej, Pilar; Huertas-Company, Marc; Marques-Chaves, Rui; Pérez-Fournon, Ismael; Rawle, Tim; Rodríguez Espinosa, José Miguel; Rosa González, Daniel; Rujopakarn, Wiphu

2017-11-01

We analyze the properties of a multiply imaged Lyα (Lyα) emitter at z = 5.75 identified through SHARDS Frontier Fields intermediate-band imaging of the Hubble Frontier Fields (HFF) cluster Abell 370. The source, A370-L57, has low intrinsic luminosity (M UV ˜ -16.5), steep UV spectral index (β = -2.4 ± 0.1), and extreme rest-frame equivalent width of Lyα ({{EW}}0({Ly}α )={420}-120+180 Å). Two different gravitational lens models predict high magnification (μ ˜ 10-16) for the two detected counterimages, separated by 7″, while a predicted third counterimage (μ ˜ 3-4) is undetected. We find differences of ˜50% in magnification between the two lens models, quantifying our current systematic uncertainties. Integral field spectroscopy of A370-L57 with MUSE shows a narrow (FWHM = 204 ± 10 km s-1) and asymmetric Lyα profile with an integrated luminosity L(Lyα) ˜ 1042 erg s-1. The morphology in the Hubble Space Telescope bands comprises a compact clump (r e < 100 pc) that dominates the Lyα and continuum emission and several fainter clumps at projected distances ≲1 kpc that coincide with an extension of the Lyα emission in the SHARDS F823W17 and MUSE observations. The latter could be part of the same galaxy or an interacting companion. We find no evidence of a contribution from active galactic nuclei to the Lyα emission. Fitting of the spectral energy distribution with stellar population models favors a very young (t < 10 Myr), low-mass ({M}* ˜ {10}6.5 {M}⊙ ), and metal-poor (Z ≲ 4 × 10-3) stellar population. Its modest star formation rate (SFR ˜ 1.0 {M}⊙ yr-1) implies high specific SFR (sSFR ˜ 2.5 × 10-7 yr-1) and SFR density ({{{Σ }}}{SFR}˜ 7{--}35 {M}⊙ yr-1 kpc-2). The properties of A370-L57 make it a good representative of the population of galaxies responsible for cosmic reionization.

The nature of luminous Lyα emitters at z ˜ 2-3: maximal dust-poor starbursts and highly ionising AGN

NASA Astrophysics Data System (ADS)

Sobral, David; Matthee, Jorryt; Darvish, Behnam; Smail, Ian; Best, Philip N.; Alegre, Lara; Röttgering, Huub; Mobasher, Bahram; Stroe, Ana Paulino-Afonso Andra; Oteo, Iván

2018-03-01

Deep narrow-band surveys have revealed a large population of faint Lyα emitters (LAEs) in the distant Universe, but relatively little is known about the most luminous sources (L_Lyα {≳} 10^{42.7} erg s-1; L_Lyα {≳} L^*_{Lyα }). Here we present the spectroscopic follow-up of 21 luminous LAEs at z ˜ 2 - 3 found with panoramic narrow-band surveys over five independent extragalactic fields (≈4 × 106 Mpc3 surveyed at z ˜ 2.2 and z ˜ 3.1). We use WHT/ISIS, Keck/DEIMOS and VLT/X-SHOOTER to study these sources using high ionisation UV lines. Luminous LAEs at z ˜ 2-3 have blue UV slopes (β =-2.0^{+0.3}_{-0.1}), high Lyα escape fractions (50^{+20}_{-15}%) and span five orders of magnitude in UV luminosity (M_{UV}≈ -19 to -24). Many (70%) show at least one high ionisation rest-frame UV line such as CIV, NV, CIII], HEII or OIII], typically blue-shifted by ≈100 - 200 km s-1 relative to Lyα. Their Lyα profiles reveal a wide variety of shapes, including significant blue-shifted components and widths from 200 to 4000 km s-1. Overall, 60 ± 11 % appear to be AGN dominated, and at L_{Lyα }>10^{43.3} erg s-1 and/or M_{UV}<-21.5 virtually all LAEs are AGN with high ionisation parameters (log U = 0.6 ± 0.5) and with metallicities of ≈0.5 - 1 Z⊙. Those lacking signatures of AGN (40 ± 11 %) have lower ionisation parameters (log U=-3.0^{+1.6}_{-0.9} and log ξion = 25.4 ± 0.2) and are apparently metal-poor sources likely powered by young, dust-poor "maximal" starbursts. Our results show that luminous LAEs at z ˜ 2-3 are a diverse population and that 2 × L^*_{Lyα } and 2 × M_UV^* mark a sharp transition in the nature of LAEs, from star formation dominated to AGN dominated.

Anomalous temporal behaviour of broadband Lyα observations during solar flares from SDO/EVE

NASA Astrophysics Data System (ADS)

Milligan, Ryan O.; Chamberlin, Phillip C.

2016-03-01

Although it is the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyα emission during solar flares in recent years. However, the few examples that do exist have shown Lyα emission to be a substantial radiator of the total energy budget of solar flares (of the order of 10%). It is also a known driver of fluctuations in the Earth's ionosphere. The EUV Variability Experiment (EVE) on board the Solar Dynamics Observatory now provides broadband, photometric Lyα data at 10 s cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (Hα, Lyβ, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission and not during the impulsive phase when energy deposition in the chromosphere (often assumed to be in the form of non-thermal electrons) is greatest. The time derivative of Lyα lightcurves also appears to resemble that of the time derivative of soft X-rays, reminiscent of the Neupert effect. Given that spectrally-resolved Lyα observations during flares from SORCE/SOLSTICE peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines and/or continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting broadband Lyα observations of solar flares. Comparisons have also been made with other broadband Lyα photometers such as PROBA2/LYRA and GOES/EUVS-E.

A New Method to Measure the Post-reionization Ionizing Background from the Joint Distribution of Lyα and Lyβ Forest Transmission

NASA Astrophysics Data System (ADS)

Davies, Frederick B.; Hennawi, Joseph F.; Eilers, Anna-Christina; Lukić, Zarija

2018-03-01

The amplitude of the ionizing background that pervades the intergalactic medium (IGM) at the end of the epoch of reionization provides a valuable constraint on the emissivity of the sources that reionized the universe. While measurements of the ionizing background at lower redshifts rely on a simulation-calibrated mapping between the photoionization rate and the mean transmission of the Lyα forest, at z ≳ 6 the IGM becomes increasingly opaque and transmission arises solely in narrow spikes separated by saturated Gunn–Peterson troughs. In this regime, the traditional approach of measuring the average transmission over large ∼50 Mpc/h regions is less sensitive and suboptimal. In addition, the five times smaller oscillator strength of the Lyβ transition implies that the Lyβ forest is considerably more transparent at z ≳ 6, even in the presence of contamination by foreground z ∼ 5 Lyα forest absorption. In this work we present a novel statistical approach to analyze the joint distribution of transmission spikes in the cospatial z ∼ 6 Lyα and Lyβ forests. Our method relies on approximate Bayesian computation (ABC), which circumvents the necessity of computing the intractable likelihood function describing the highly correlated Lyα and Lyβ transmission. We apply ABC to mock data generated from a large-volume hydrodynamical simulation combined with a state-of-the-art model of ionizing background fluctuations in the post-reionization IGM and show that it is sensitive to higher IGM neutral hydrogen fractions than previous techniques. As a proof of concept, we apply this methodology to a real spectrum of a z = 6.54 quasar and measure the ionizing background from 5.4 ≤ z ≤ 6.4 along this sightline with ∼0.2 dex statistical uncertainties. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Unlocking the Full Potential of Extragalactic Lyα through Its Polarization Properties

NASA Astrophysics Data System (ADS)

Eide, Marius B.; Gronke, Max; Dijkstra, Mark; Hayes, Matthew

2018-04-01

Lyα is a powerful astrophysical probe. Not only is it ubiquitous at high redshifts, it is also a resonant line, making Lyα photons scatter. This scattering process depends on the physical conditions of the gas through which Lyα propagates, and these conditions are imprinted on observables such as the Lyα spectrum and its surface brightness profile. In this work, we focus on a less-used observable capable of probing any scattering process: polarization. We implement the density matrix formalism of polarization into the Monte Carlo radiative transfer code tlac. This allows us to treat it as a quantum mechanical process where single photons develop and lose polarization from scatterings in arbitrary gas geometries. We explore static and expanding ellipsoids, biconical outflows, and clumpy multiphase media. We find that photons become increasingly polarized as they scatter and diffuse into the wings of the line profiles, making scattered Lyα polarized in general. The degree and orientation of Lyα polarization depends on the kinematics and distribution of the scattering H I gas. We find that it generally probes spatial or velocity space asymmetries and aligns itself tangentially to the emission source. We show that the mentioned observables, when studied separately, can leave similar signatures for different source models. We conclude by revealing how a joint analysis of the Lyα spectra, surface brightness profiles, and polarization can break these degeneracies and help us extract unique physical information on galaxies and their environments from their strongest, most prominent emission line.

OVERTURNING THE CASE FOR GRAVITATIONAL POWERING IN THE PROTOTYPICAL COOLING LYα NEBULA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prescott, Moire K. M.; Fynbo, Johan P. U.; Momcheva, Ivelina

The Nilsson et al. Lyα nebula has often been cited as the most plausible example of an Lyα nebula powered by gravitational cooling. In this paper, we bring together new data from the Hubble Space Telescope and the Herschel Space Observatory as well as comparisons to recent theoretical simulations in order to revisit the questions of the local environment and most likely power source for the Lyα nebula. In contrast to previous results, we find that this Lyα nebula is associated with six nearby galaxies and an obscured AGN that is offset by ∼4″ ≈ 30 kpc from the Lyαmore » peak. The local region is overdense relative to the field, by a factor of ∼10, and at low surface brightness levels the Lyα emission appears to encircle the position of the obscured AGN, highly suggestive of a physical association. At the same time, we confirm that there is no compact continuum source located within ∼2–3″ ≈ 15–23 kpc of the Lyα peak. Since the latest cold accretion simulations predict that the brightest Lyα emission will be coincident with a central growing galaxy, we conclude that this is actually a strong argument against, rather than for, the idea that the nebula is gravitationally powered. While we may be seeing gas within cosmic filaments, this gas is primarily being lit up, not by gravitational energy, but due to illumination from a nearby buried AGN.« less

Physical properties of z ~ 4 LBGs: differences between galaxies with and without Lyα emission

NASA Astrophysics Data System (ADS)

Pentericci, L.; Grazian, A.; Fontana, A.; Salimbeni, S.; Santini, P.; de Santis, C.; Gallozzi, S.; Giallongo, E.

2007-08-01

Aims:We analysed the physical properties of z ˜4 Lyman Break Galaxies observed in the GOODS-S survey, in order to investigate possible differences between galaxies where the Lyα is present in emission, and those where the line is absent or in absorption. Methods: The objects were selected from their optical color and then spectroscopically confirmed by Vanzella et al. (2005). From the public spectra we assessed the nature of the Lyα emission and divided the sample into galaxies with Lyα in emission and objects without a Lyα line (i.e. either absent or in absorption). We then used complete photometry, from U band to mid-infrared from the GOODS-MUSIC database, to study the observational properties of the galaxies, such as UV spectral slopes and optical to mid-infrared colors, and the possible differences between the two samples. Lastly, we used standard spectral fitting techniques to determine the physical properties of the galaxies, such as total stellar mass, stellar ages and so on, and again we looked at the possible differences between the two samples. Results: Our results indicate that LBG with Lyα in emission are on average a much younger and less massive population than the LBGs without Lyα emission. Both populations are forming stars very actively and are relatively dust free, although those with line emission seem to be even less dusty on average. We briefly discuss these results in the context of recent models for the evolution of Lyman break galaxies and Lyα emitters.

Results from clinical trials of a selective ionotropic glutamate receptor 5 (iGluR5) antagonist, LY5454694 tosylate, in 2 chronic pain conditions.

PubMed

Chappell, Amy S; Iyengar, Smriti; Lobo, Evelyn D; Prucka, William R

2014-06-01

This article reports results of 2 studies investigating LY545694 in pain due to osteoarthritis (OA) of the knee and diabetic peripheral neuropathic pain (DPNP). Study I randomized patients to either of 2 doses of LY545694 or to placebo, and study II randomized patients to either of 3 doses of LY545694, to pregabalin, or to placebo. No significant differences between LY545694 groups and placebo were observed on the primary (average pain severity) or secondary efficacy measures in either study. Notably, study I lacked an active control, and, in study II, pregabalin, did not separate from placebo. Treatment-emergent nausea, vomiting, and dizziness were significantly more frequent in the LY545694 groups in both trials (P⩽.05), and significantly more LY545694-treated patients discontinued because of adverse events (P<.001). Steady-state concentrations of LY545694 were comparable in patients in both studies but were lower than exposures required for efficacy in animal models of pain behavior. Because the active control did not separate from placebo in the DPNP study, the study was potentially failed, rather than negative. Without an active control, it is unknown whether the OA study was negative or failed. Consequently, efficacy of selective ionotropic glutamate receptor antagonism in chronic pain conditions may warrant further investigation. Future trials should consider different pain conditions, contain a positive control with larger patient numbers per arm, and be conducted within a single region. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Postsynaptic and presynaptic group II metabotropic glutamate receptor activation reduces neuronal excitability in rat midline paraventricular thalamic nucleus.

PubMed

Hermes, M L H J; Renaud, L P

2011-03-01

Drugs that interact with group II metabotropic glutamate receptors (mGluRs) are presently being evaluated for a role in the treatment of anxiety disorders and symptoms of schizophrenia. Their mechanism of action is believed to involve a reduction in excitatory neurotransmission in limbic and forebrain regions commonly associated with these mental disorders. In rodents, the glutamatergic neurons in the midline paraventricular thalamic nucleus (PVT) provide excitatory inputs to the limbic system and forebrain. PVT also displays a high density of group II mGluRs, predominantly the metabotropic glutamate 2 receptor (mGluR2). Because the role of group II mGluRs in regulating cellular and synaptic excitability in this location has yet to be determined, we used whole-cell patch-clamp recording and acute rat brain slice preparations to evaluate PVT neuron responses to a selective group II mGluR agonist, (1R,4R,5S,6R)-4-amino-2-oxabicyclo[3.1.0]hexane-4,6-dicarboxylic acid (LY 379268). LY 379268 consistently induced membrane hyperpolarization and suppressed firing by postsynaptic receptor-mediated activation of a barium-sensitive background K(+) conductance. This effect could be blocked by (2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl)propanoic acid (LY 341495), a selective group II mGluR antagonist. In addition, LY 379268 acted at presynaptic receptors to reduce ionotropic glutamate receptor-mediated excitatory synaptic transmission. An mGluR2-positive allosteric modulator, 2,2,2-trifluoro-N-[4-(2-methoxyphenoxy)phenyl]-N-(3-pyridinylmethyl)ethanesulfonamide hydrochloride (LY 487379), resulted in leftward shifts of the LY 379268 dose-response curve for both postsynaptic and presynaptic actions. The data demonstrate that activation of postsynaptic and presynaptic group II (presumably mGluR2) mGluRs reduces neuronal excitability in midline thalamus, an action that may contribute to the effectiveness of mGluR2-activating drugs in rodent models of anxiety and psychosis.

Pharmacological characterization of stress-induced hyperthermia in DBA/2 mice using metabotropic and ionotropic glutamate receptor ligands.

PubMed

Rorick-Kehn, Linda M; Hart, John C; McKinzie, David L

2005-12-01

Accumulating evidence suggests that drugs acting on the glutamatergic system may represent promising novel therapeutic targets for the treatment of anxiety disorders. The stress-induced hyperthermia paradigm has been used widely to model some of the physiological symptoms associated with anxiety disorders and has produced results that are predictive of clinical efficacy. We have modified this paradigm to measure the autonomic consequences of stress induced by the fear of predation in mice. To evaluate the efficacy of several classes of metabotropic and ionotropic glutamate receptor ligands, as well as known anxiolytics and psychotropic comparators, in attenuating predatory-stress-induced hyperthermia. Male DBA/2 mice were implanted with radiotelemetric transmitters in the peritoneal cavity to measure stress-related increases in core body temperature, following placement in a novel cage containing soiled rat shavings. Clinically active compounds such as chlordiazepoxide (5-10 mg/kg), alprazolam (0.3-3 mg/kg), and buspirone (10-30 mg/kg) exhibited an anxiolytic profile. Assessment of glutamatergic agents indicated that the mGlu1 receptor antagonist LY456236 (10-30 mg/kg), mGlu5 receptor antagonist MPEP (10-30 mg/kg), mGlu2/3 receptor agonist LY354740 (3-10 mg/kg), mGlu2 receptor potentiator LY566332 (30 and 100 mg/kg), mGlu8 receptor agonist (S)-3,4-dicarboxyphenylglycine (30-60 mg/kg), competitive NMDA receptor antagonist LY235959 (1 mg/kg), AMPA receptor antagonist GYKI-52466 (10-20 mg/kg), and glycine transporter-1 (GlyT-1) inhibitor ALX-5407 (3-10 mg/kg) dose-dependently attenuated stress-induced hyperthermia. The AMPA receptor potentiator LY451646, iGlu5 kainate receptor antagonist LY382884, glycine(B) receptor partial agonist D: -cycloserine, and GlyT-1 inhibitor ORG-24461 were ineffective in this model. Select metabotropic and ionotropic glutamate receptor ligands exhibited an anxiolytic profile, as measured by the attenuation of stress-induced hyperthermia, and may represent viable targets for the development of pharmacological treatments for anxiety-related disorders.

Molecular diagnostics of FUV and accretion-related heating in protoplanetary disks

NASA Astrophysics Data System (ADS)

Adamkovics, Mate; Najita, Joan R.

2017-10-01

Emission lines from the terrestrial planet forming regions of disks are diagnostic of both the physical processes that heat the gas and the chemistry that determines the inventory of nebular material available during the epoch of planet formation. Interpreting emission spectra is informed by models of radiative, thermal, physical, and chemical processes, such as: (i) the radiation transfer of X-rays and FUV --- both continuum and Ly-alpha, (ii) direct and indirect heating processes such as the photoelectric effect and photochemical heating, (iii) heating related to turbulent processes and viscous dissipation, and (iv) gas phase chemical reaction kinetics. Many of these processes depend on a the spatial distribution of dust grains and their properties, which temporally evolve during the lifetime of the disk and the formation of planets. Studies of disks atmospheres often predict a layered structure of hot (a few thousand K) atomic gas overlying warm (a few hundred K) molecular gas, which is generally consistent with the isothermal slab emission models that are used to interpret emission spectra. However, detailed comparison between observed spectra and models (e.g., comparing the total columns and the radial extent of warm emitting species) is rare.We present results including the implementation of Ly-alpha scattering, which is an important part of the photochemical heating and FUV heating radiation budget. By including these processes we find a new component of the disk atmosphere; hot molecular gas at ~2000K within radial distances of ~0.5AU, which is consistent with observations of UV-fluorescent H2 emission (Ádámkovics, Najita & Glassgold, 2016). Constraining the most optimistic contribution of radiative heating mechanisms via X-rays and FUV together with a favorable comparison to observations, allows us to explore and evaluate additional heating mechanisms. We find that the total columns of warm (90-400K) emitting molecules such as CO, arising directly below the irradiated molecular layer, are diagnostic of the role of turbulent (viscous) mechanical heating. We discuss how the total columns of warm molecules in this layer may be diagnostic of the magnetorotational instability (Najita & Ádámkovics, 2017).

[Development and validation of event-specific quantitative PCR method for genetically modified maize LY038].

PubMed

Mano, Junichi; Masubuchi, Tomoko; Hatano, Shuko; Futo, Satoshi; Koiwa, Tomohiro; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi

2013-01-01

In this article, we report a novel real-time PCR-based analytical method for quantitation of the GM maize event LY038. We designed LY038-specific and maize endogenous reference DNA-specific PCR amplifications. After confirming the specificity and linearity of the LY038-specific PCR amplification, we determined the conversion factor required to calculate the weight-based content of GM organism (GMO) in a multilaboratory evaluation. Finally, in order to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind DNA samples containing LY038 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The precision of the method was evaluated as the RSD of reproducibility (RSDR), and the values obtained were all less than 25%. The limit of quantitation of the method was judged to be 0.5% based on the definition of ISO 24276 guideline. The results from the collaborative trial suggested that the developed quantitative method would be suitable for practical testing of LY038 maize.

Lymphocytic esophagitis: Report of three cases and review of the literature

PubMed Central

Jideh, Bilel; Keegan, Andrew; Weltman, Martin

2016-01-01

Lymphocytic esophagitis (LyE) is a rare condition characterised histologically by high numbers of esophageal intraepithelial lymphocytes without significant granulocytes infiltration, in addition to intercellular edema (“spongiosis”). The clinical significance and natural history of LyE is poorly defined although dysphagia is reportedly the most common symptom. Endoscopic features range from normal appearing esophageal mucosa to features similar to those seen in eosinophilic esophagitis, including esophageal rings, linear furrows, whitish exudates, and esophageal strictures/stenosis. Symptomatic gastroesophageal reflux disease is an inconsistent association. LyE has been associated in paediatric Crohn’s disease, and recently in primary esophageal dysmotility disorder in adults. There are no studies assessing effective treatment strategies for LyE; empirical therapies have included use of proton pump inhibitor and corticosteroids. Esophageal dilatation have been used to manage esophageal strictures. LyE has been reported to run a benign course; however there has been a case of esophageal perforation associated with LyE. Here, we describe the clinical, endoscopic and histopathological features of three patients with lymphocytic esophagitis along with a review of the current literature. PMID:28035315

Fluorescence life-time imaging and steady state polarization for examining binding of fluorophores to gold nanoparticles.

PubMed

Schwartz, Shmulik; Fixler, Dror; Popovtzer, Rachela; Shefi, Orit

2015-11-01

Nanocomposites as multifunctional agents are capable of combing imaging and cell biology technologies. The conventional methods used for validation of the conjugation process of nanoparticles (NPs) to fluorescent molecules such as spectroscopy analysis and surface potential measurements, are not sufficient. In this paper we present a new and highly sensitive procedure that uses the combination of (1) fluorescence spectrum, (2) fluorescence lifetime, and (3) steady state fluorescence polarization measurements. We characterize and analyze gold NPs with Lucifer yellow (LY) surface coating as a model. We demonstrate the ability to differentiate between LY-GNP (the conjugated complex) and a mixture of coated NP and free dyes. We suggest the approach for neuroscience applications where LY is used for detecting and labeling cells, studying morphology and intracellular communications. Histograms of Fluorescence lifetime imaging (FLIM) of free LY dye (Left) in comparison to the conjugated dye to gold nanoparticles, LY-GNP (Middle) enable the differentiation between LY-GNP (the conjugated complex) and a mixture of coated NP and free dyes (Right). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lyman-α emitters gone missing: the different evolution of the bright and faint populations

NASA Astrophysics Data System (ADS)

Weinberger, Lewis H.; Kulkarni, Girish; Haehnelt, Martin G.; Choudhury, Tirthankar Roy

2018-06-01

We model the transmission of the Lyman-α line through the circum- and intergalactic media around dark matter haloes expected to host Lyman-alpha emitters (LAEs) at z ≥ 5.7, using the high-dynamic-range Sherwood simulations. We find very different CGM environments around more massive haloes (˜1011M⊙) compared to less massive haloes (˜109M⊙) at these redshifts, which can contribute to a different evolution of the Lyα transmission from LAEs within these haloes. Additionally we confirm that part of the differential evolution could result from bright LAEs being more likely to reside in larger ionized regions. We conclude that a combination of the CGM environment and the IGM ionization structure is likely to be responsible for the differential evolution of the bright and faint ends of the LAE luminosity function at z ≥ 6. More generally, we confirm the suggestion that the self-shielded neutral gas in the outskirts of the host halo can strongly attenuate the Lyα emission from high redshift galaxies. We find that this has a stronger effect on the more massive haloes hosting brighter LAEs. The faint-end of the LAE luminosity function is thus a more reliable probe of the average ionization state of the IGM. Comparing our model for LAEs with a range of observational data we find that the favoured reionization histories are our previously advocated `Late' and `Very Late' reionization histories, in which reionization finishes rather rapidly at around z ≃ 6.

Interstellar Deuterium, Nitrogen and Oxygen Abundances Toward BD+28(deg) 4211: Results from the Far Ultraviolet Spectroscopic Explorer

NASA Technical Reports Server (NTRS)

Sonneborn, George; Andre, Martial; Oliveira, Cristina; Hebrard, Guillaume; Howk, J. Christopher; Tripp, Todd M.; Chayer, Pierre; Friedman, Scott D.; Kruk, Jeffery W.; Jenkins, Edward B.;

Ly6G-mediated depletion of neutrophils is dependent on macrophages.

PubMed

Bruhn, Kevin W; Dekitani, Ken; Nielsen, Travis B; Pantapalangkoor, Paul; Spellberg, Brad

2016-01-01

Antibody-mediated depletion of neutrophils is commonly used to study neutropenia. However, the mechanisms by which antibodies deplete neutrophils have not been well defined. We noticed that mice deficient in complement and macrophages had blunted neutrophil depletion in response to anti-Ly6G monoclonal antibody (MAb) treatment. In vitro, exposure of murine neutrophils to anti-Ly6G MAb in the presence of plasma did not result in significant depletion of cells, either in the presence or absence of complement. In vivo, anti-Ly6G-mediated neutrophil depletion was abrogated following macrophage depletion, but not complement depletion, indicating a requirement for macrophages to induce neutropenia by this method. These results inform the use and limitations of anti-Ly6G antibody as an experimental tool for depleting neutrophils in various immunological settings.

SILVERRUSH. VI. A simulation of Lyα emitters in the reionization epoch and a comparison with Subaru Hyper Suprime-Cam survey early data

NASA Astrophysics Data System (ADS)

Inoue, Akio K.; Hasegawa, Kenji; Ishiyama, Tomoaki; Yajima, Hidenobu; Shimizu, Ikkoh; Umemura, Masayuki; Konno, Akira; Harikane, Yuichi; Shibuya, Takatoshi; Ouchi, Masami; Shimasaku, Kazuhiro; Ono, Yoshiaki; Kusakabe, Haruka; Higuchi, Ryo; Lee, Chien-Hsiu

2018-06-01

The survey of Lyman α emitters (LAEs) with the Subaru Hyper Suprime-Cam, called SILVERRUSH (Ouchi et al. 2018, PASJ, 70, S13), is producing massive data of LAEs at z ≳ 6. Here we present LAE simulations to compare the SILVERRUSH data. In 1623 comoving Mpc3 boxes, where numerical radiative transfer calculations of reionization were performed, LAEs have been modeled with physically motivated analytic recipes as a function of halo mass. We have examined 23 models depending on the presence or absence of dispersion of halo Lyα emissivity, dispersion of the halo Lyα optical depth, τα, and halo mass dependence of τα. The unique free parameter in our model, a pivot value of τα, is calibrated so as to reproduce the z = 5.7 Lyα luminosity function (LF) of SILVERRUSH. We compare our model predictions with Lyα LFs at z = 6.6 and 7.3, LAE angular auto-correlation functions (ACFs) at z = 5.7 and 6.6, and LAE fractions in Lyman break galaxies at 5 < z < 7. The Lyα LFs and ACFs are reproduced by multiple models, but the LAE fraction turns out to be the most critical test. The dispersion of τα and the halo mass dependence of τα are essential to explain all observations reasonably. Therefore, a simple model of one-to-one correspondence between halo mass and Lyα luminosity with a constant Lyα escape fraction has been ruled out. Based on our best model, we present a formula to estimate the intergalactic neutral hydrogen fraction, x_{H I}, from the observed Lyα luminosity density at z ≳ 6. We finally obtain x_{H I}=0.5_{-0.3}^{+0.1} as a volume-average at z = 7.3.

Functional Heterogeneity in the CD4+ T Cell Response to Murine γ-Herpesvirus 68

PubMed Central

Hu, Zhuting; Blackman, Marcia A.; Kaye, Kenneth M.; Usherwood, Edward J.

2015-01-01

CD4+ T cells are critical for the control of virus infections, T cell memory and immune surveillance. Here we studied the differentiation and function of murine γ-herpesvirus 68 (MHV-68)-specific CD4+ T cells using gp150-specific TCR transgenic mice. This allowed a more detailed study of the characteristics of the CD4+ T cell response than previously available approaches for this virus. Most gp150-specific CD4+ T cells expressed T-bet and produced IFN-γ, indicating MHV-68 infection triggered differentiation of CD4+ T cells largely into the Th1 subset, whereas some became TFH and Foxp3+ regulatory T cells. These CD4+ T cells were protective against MHV-68 infection, in the absence of CD8+ T cells and B cells, and protection depended on IFN-γ secretion. Marked heterogeneity was observed in the CD4+ T cells, based on Ly6C expression. Ly6C expression positively correlated with IFN-γ, TNF-α and granzyme B production, T-bet and KLRG1 expression, proliferation and CD4+ T cell-mediated cytotoxicity. Ly6C expression inversely correlated with survival, CCR7 expression and secondary expansion potential. Ly6C+ and Ly6C− gp150-specific CD4+ T cells were able to interconvert in a bidirectional manner upon secondary antigen exposure in vivo. These results indicate that Ly6C expression is closely associated with antiviral activity in effector CD4+ T cells, but inversely correlated with memory potential. Interconversion between Ly6C+ and Ly6C− cells may maintain a balance between the two antigen-specific CD4+ T cell populations during MHV-68 infection. These findings have significant implications for Ly6C as a surface marker to distinguish functionally distinct CD4+ T cells during persistent virus infection. PMID:25662997

Assessment of the relationships among coagulopathy, hyperfibrinolysis, plasma lactate, and protein C in dogs with spontaneous hemoperitoneum.

PubMed

Fletcher, Daniel J; Rozanski, Elizabeth A; Brainard, Benjamin M; de Laforcade, Armelle M; Brooks, Marjory B

2016-01-01

To relate coagulation and fibrinolysis derangements to shock severity as reflected by plasma lactate concentrations in dogs with spontaneous hemoperitoneum (SHP) and determine the impact on transfusions. Prospective, observational, case-control study. Three veterinary teaching hospitals. Twenty-eight client-owned dogs with SHP and 28 breed- and age-matched control dogs. None. Blood samples for platelet counts, coagulation, and anticoagulant assays (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, and protein C, thromboelastography [TEG]), fibrinolysis testing (d-dimer and TEG lysis parameters with and without the addition of 50 U/mL of tissue plasminogen activator [TEG LY30 measured with the addition of 50 U/mL of tPA to the blood sample, LY3050 and TEG LY60 measured with the addition of 50 U/mL of tPA to the blood sample, LY6050 ; LY30 and LY60]), and plasma lactate as an indicator of severity of shock were collected from SHP dogs at the time of diagnosis. SHP dogs were hypocoagulable (prolonged prothrombin time and activated partial thromboplastin time, decreased TEG maximum amplitude) and hyperfibrinolytic (increased LY3050 and TEG LY6050 ) compared to controls. The severity of hypocoagulability was related to protein C activity, while the severity of hyperfibrinolysis was related to plasma lactate concentration. Among the 18 dogs discharged from the hospital, LY3050 was significantly associated with the dose of fresh frozen plasma administered, but none of the parameters were associated with the dose of red blood cells administered. Dogs with SHP have evidence of hypocoagulability, protein C deficiency, and hyperfibrinolysis. Parameters of hyperfibrinolysis were related to plasma lactate concentrations and volume of plasma transfused during hospitalization. These derangements resemble those found in people with acute coagulopathy of trauma and shock, and activation of protein C may be a common feature to both syndromes. © Veterinary Emergency and Critical Care Society 2015.

SILVERRUSH. VI. A simulation of Lyα emitters in the reionization epoch and a comparison with Subaru Hyper Suprime-Cam survey early data

NASA Astrophysics Data System (ADS)

Inoue, Akio K.; Hasegawa, Kenji; Ishiyama, Tomoaki; Yajima, Hidenobu; Shimizu, Ikkoh; Umemura, Masayuki; Konno, Akira; Harikane, Yuichi; Shibuya, Takatoshi; Ouchi, Masami; Shimasaku, Kazuhiro; Ono, Yoshiaki; Kusakabe, Haruka; Higuchi, Ryo; Lee, Chien-Hsiu

2018-05-01

The survey of Lyman α emitters (LAEs) with the Subaru Hyper Suprime-Cam, called SILVERRUSH (Ouchi et al. 2018, PASJ, 70, S13), is producing massive data of LAEs at z ≳ 6. Here we present LAE simulations to compare the SILVERRUSH data. In 1623 comoving Mpc3 boxes, where numerical radiative transfer calculations of reionization were performed, LAEs have been modeled with physically motivated analytic recipes as a function of halo mass. We have examined 23 models depending on the presence or absence of dispersion of halo Lyα emissivity, dispersion of the halo Lyα optical depth, τα, and halo mass dependence of τα. The unique free parameter in our model, a pivot value of τα, is calibrated so as to reproduce the z = 5.7 Lyα luminosity function (LF) of SILVERRUSH. We compare our model predictions with Lyα LFs at z = 6.6 and 7.3, LAE angular auto-correlation functions (ACFs) at z = 5.7 and 6.6, and LAE fractions in Lyman break galaxies at 5 < z < 7. The Lyα LFs and ACFs are reproduced by multiple models, but the LAE fraction turns out to be the most critical test. The dispersion of τα and the halo mass dependence of τα are essential to explain all observations reasonably. Therefore, a simple model of one-to-one correspondence between halo mass and Lyα luminosity with a constant Lyα escape fraction has been ruled out. Based on our best model, we present a formula to estimate the intergalactic neutral hydrogen fraction, x_{H I}, from the observed Lyα luminosity density at z ≳ 6. We finally obtain x_{H I}=0.5_{-0.3}^{+0.1} as a volume-average at z = 7.3.

Spectroscopic Constraints on UV Metal Line Emission at z ≃ 6 - 9 The Nature of Lyα Emitting Galaxies in the Reionization-Era

NASA Astrophysics Data System (ADS)

Mainali, Ramesh; Zitrin, Adi; Stark, Daniel P.; Ellis, Richard S.; Richard, Johan; Tang, Mengtao; Laporte, Nicolas; Oesch, Pascal; McGreer, Ian

2018-06-01

Recent studies have revealed intense UV metal emission lines in a modest sample of z > 7 Lyman-α emitters, indicating a hard ionizing spectrum is present. If such high ionization features are shown to be common, it may indicate that extreme radiation fields play a role in regulating the visibility of Lyα in the reionization era. Here we present deep near-infrared spectra of seven galaxies with Lyα emission at 5.4 < z < 8.7 (including a newly-confirmed lensed galaxy at zLyα = 6.031) and three bright z ≃ 7 photometric targets. In nine sources we do not detect UV metal lines. However in the zLyα = 8.683 galaxy EGSY8p7, we detect a 4.6σ emission line in the narrow spectral window expected for NVλ1243. The feature is unresolved (FWHM<90 km s-1) and is likely nebular in origin. A deep H-band spectrum of EGSY8p7 reveals non-detections of CIV, He II, and OIII]. The presence of NV requires a substantial flux of photons above 77 eV, pointing to a hard ionizing spectrum powered by an AGN or fast radiative shocks. Regardless of its origin, the intense radiation field of EGSY8p7 may aid the transmission of Lyα through what is likely a partially neutral IGM. With this new detection, five of thirteen known Lyα emitters at z > 7 have now been shown to have intense UV line emission, suggesting that extreme radiation fields are commonplace among the Lyα population. Future observations with JWST will eventually clarify the origin of these features and explain their role in the visibility of Lyα in the reionization era.

An immunocapture/scintillation proximity analysis of G alpha q/11 activation by native serotonin (5-HT)2A receptors in rat cortex: blockade by clozapine and mirtazapine.

PubMed

Mannoury La Cour, C; Chaput, C; Touzard, M; Millan, M J

2009-02-01

Though transduction mechanisms recruited by heterologously expressed 5-HT(2A) receptors have been extensively studied, their interaction with specific subtypes of G-protein remains to be directly evaluated in cerebral tissue. Herein, as shown by an immunocapture/scintillation proximity analysis, 5-HT, the prototypical 5-HT(2A) agonist, DOI, and Ro60,0175 all enhanced [(35)S]GTPgammaS binding to G alpha q/11 in rat cortex with pEC(50) values of 6.22, 7.24 and 6.35, respectively. No activation of G o or G s/olf was seen at equivalent concentrations of DOI. Stimulation of G alpha q/11 by 5-HT (30 microM) and DOI (30 microM) was abolished by the selective 5-HT(2A) vs. 5-HT(2C)/5-HT(2B) antagonists, ketanserin (pK(B) values of 9.11 and 8.88, respectively) and MDL100,907 (9.82 and 9.68). By contrast, 5-HT-induced [(35)S]GTPgammaS binding to G alpha q/11 was only weakly inhibited by the preferential 5-HT(2C) receptor antagonists, RS102,221 (6.94) and SB242,084 (7.39), and the preferential 5-HT(2B) receptor antagonist, LY266,097 (6.66). The antipsychotic, clozapine, which had marked affinity for 5-HT(2A) receptors, blocked the recruitment of G alpha q/11 by 5-HT and DOI with pK(B) values of 8.54 and 8.14, respectively. Its actions were mimicked by the "atypical" antidepressant and 5-HT(2A) receptor antagonist, mirtazapine, which likewise blocked 5-HT and DOI-induced G alpha q/11 protein activation with pK(B) values of 7.90 and 7.76, respectively. In conclusion, by use of an immunocapture/scintillation proximity strategy, this study shows that native 5-HT(2A) receptors in rat frontal cortex specifically recruit G alpha q/11 and that this action is blocked by clozapine and mirtazapine. Quantification of 5-HT(2A) receptor-mediated G alpha q/11 activation in frontal cortex should prove instructive in characterizing the actions of diverse classes of psychotropic agent. 2008 Wiley-Liss, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Wang, JunXian; Zheng, Zhen-Ya

Using the Lyα emission line as a tracer of high-redshift, star-forming galaxies, hundreds of Lyα emission line galaxies (LAEs) at z > 5 have been detected. These LAEs are considered to be low-mass young galaxies, critical to the re-ionization of the universe and the metal enrichment of the circumgalactic medium (CGM) and the intergalactic medium (IGM). It is assumed that outflows in LAEs can help both ionizing photons and Lyα photons escape from galaxies. However, we still know little about the outflows in high-redshift LAEs due to observational difficulties, especially at redshift >5. Models of Lyα radiative transfer predict asymmetricmore » Lyα line profiles with broad red wings in LAEs with outflows. Here, we report a z ∼ 5.7 Lyα emission line with a broad red wing extending to >1000 km s{sup –1} relative to the peak of Lyα line, which has been detected in only a couple of z > 5 LAEs until now. If the broad red wing is ascribed to gas outflow instead of active galactic nucleus activity, the outflow velocity could be larger than the escape velocity (∼500 km s{sup –1}) of a typical halo mass of z ∼ 5.7 LAEs, which is consistent with the idea that outflows in LAEs disperse metals to CGM and IGM.« less

Synergistic Lethality of Mifepristone and LY294002 in Ovarian Cancer Cells

PubMed Central

Wempe, Stacy L.; Gamarra-Luques, Carlos D.; Telleria, Carlos M.

2013-01-01

We have previously shown that the antiprogestin and antiglucocorticoid mifepristone inhibits the growth of ovarian cancer cells. In this work, we hypothesized that cellular stress caused by mifepristone is limited to cytostasis and that cell killing is avoided as a consequence of the persistent activity of the PI3K/Akt survival pathway. To investigate the role of this pathway in mifepristone-induced growth inhibition, human ovarian cancer cells of various histological subtypes and genetic backgrounds were exposed to cytostatic doses of mifepristone in the presence or absence of the PI3K inhibitor, LY294002. The activation of Akt in ovarian cancer cells, as marked by its phosphorylation on Ser473, was not modified by cytostatic concentrations of mifepristone, but it was blocked upon treatment with LY294002. The combination mifepristone/LY294002, but not the individual drugs, killed ovarian cancer cells via apoptosis, as attested by genomic DNA fragmentation and cleavage of caspase-3, and the concomitant downregulation of antiapoptotic proteins Bcl-2 and XIAP. From a pharmacological standpoint, when assessing cell growth inhibition using a median-dose analysis algorithm, the interaction between mifepristone and LY294002 was synergistic. The lethality caused by the combination mifepristone/LY294004 in 2-dimensional cell cultures was recapitulated in organized, 3-dimensional spheroids. This study demonstrates that mifepristone and LY294002 when used individually cause cell growth arrest; yet, when combined, they cause lethality. PMID:23420486

Subpopulations of M-MDSCs from mice infected by an immunodeficiency-causing retrovirus and their differential suppression of T- vs B-cell responses.

PubMed

O'Connor, Megan A; Fu, Whitney W; Green, Kathy A; Green, William R

2015-11-01

Monocytic (CD11b(+)Ly6G(±/Lo)Ly6C(+)) myeloid derived suppressor cells (M-MDSCs) expand following murine retroviral LP-BM5 infection and suppress ex vivo polyclonal T-cell and B-cell responses. M-MDSCs 3 weeks post LP-BM5 infection have decreased suppression of T-cell, but not B-cell, responses and alterations in the degree of iNOS/NO dependence of suppression. M-MDSCs from LP-BM5 infected mice were sorted into four quadrant populations (Ly6C/CD11b density): all quadrants suppressed B-cell responses, but only M-MDSCs expressing the highest levels of Ly6C and CD11b (Q2) significantly suppressed T-cell responses. Further subdivision of this Q2 population revealed the Ly6C(+/Hi) M-MDSC subpopulation as the most suppressive, inhibiting T- and B-cell responses in a full, or partially, iNOS/NO-dependent manner, respectively. In contrast, the lower/moderate levels of suppression by the Ly6C(+/Lo) and Ly6C(+/Mid) M-MDSC Q2 subpopulations, whether versus T- and/or B-cells, displayed little/no iNOS dependency for suppression. These results highlight differential phenotypic and functional immunosuppressive M-MDSC subsets in a retroviral immunodeficiency model. Published by Elsevier Inc.

Dose-dependent acute liver injury with hypersensitivity features in humans due to a novel microsomal prostaglandin E synthase 1 inhibitor.

PubMed

Jin, Yan; Regev, Arie; Kam, Jeanelle; Phipps, Krista; Smith, Claire; Henck, Judith; Campanale, Kristina; Hu, Leijun; Hall, D Greg; Yang, Xiao Yan; Nakano, Masako; McNearney, Terry Ann; Uetrecht, Jack; Landschulz, William

2018-01-01

LY3031207, a novel microsomal prostaglandin E synthase 1 inhibitor, was evaluated in a multiple ascending dose study after nonclinical toxicology studies and a single ascending dose study demonstrated an acceptable toxicity, safety and tolerability profile. Healthy subjects were randomized to receive LY3031207 (25, 75 and 275 mg), placebo or celecoxib (400 mg) once daily for 28 days. The safety, tolerability and pharmacokinetic and pharmacodynamic profiles of LY3031207 were evaluated. The study was terminated when two subjects experienced drug-induced liver injury (DILI) after they had received 225 mg LY3031207 for 19 days. Liver biopsy from these subjects revealed acute liver injury with eosinophilic infiltration. Four additional DILI cases were identified after LY3031207 dosing had been stopped. All six DILI cases shared unique presentations of hepatocellular injury with hypersensitivity features and demonstrated a steep dose-dependent trend. Prompt discontinuation of the study drug and supportive medical care resulted in full recovery. Metabolites from metabolic activation of the imidazole ring were observed in plasma and urine samples from all subjects randomized to LY3031207 dosing. This study emphasized the importance of careful safety monitoring and serious adverse events management in phase I trials. Metabolic activation of the imidazole ring may be involved in the development of hepatotoxicity of LY3031207. © 2017 The British Pharmacological Society.

Ly49H Engagement Compensates for the Absence of Type I Interferon Signaling in Stimulating NK Cell Proliferation during MCMV Infection

PubMed Central

Geurs, Theresa L.; Zhao, Yun M.; Hill, Elaise B.; French, Anthony R.

2009-01-01

NK cells vigorously proliferate during viral infections, resulting in an expanded pool of innate lymphocytes that are able to participate in early host defense. The relative contributions of cytokines and activation receptors in stimulating NK cell proliferation during viral infections are not well characterized. In this study, we demonstrated that signaling through the NK cell activation receptor Ly49H was able to compensate for the absence of cytokine stimulation in the preferential phase of viral-induced proliferation during MCMV infection. In the absence of type I interferon stimulation, NK cell proliferation was strongly biased toward cells expressing the Ly49H receptor, even at early time points when minimal preferential Ly49H-mediated proliferation was observed in wild-type mice. In the absence of effective Ly49H signaling or following infection with virus that did not express the ligand for Ly49H, no difference was observed in the proliferation of subsets of NK cells that either express or lack expression of Ly49H, although the overall proliferation of NK cells in IFNαβR−/− mice was substantially reduced. These results highlight the contribution of NK cell activation receptors in stimulating proliferation and subsequent expansion of NK cells that are able to recognize virally infected cells. PMID:19828630

On the Decreasing Fraction of Strong Ly α Emitters around z ∼ 6-7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadoun, Raphael; Zheng, Zheng; Miralda-Escudé, Jordi, E-mail: raphael.sadoun@utah.edu

2017-04-10

The fraction of galaxies with strong Ly α emission has been observed to decrease rapidly with redshift at z ≳ 6, after a gradual increase at z < 6. This has been interpreted as being a trace of the reionization of the intergalactic medium (IGM): the emitted Ly α photons would be scattered by an increasingly neutral IGM at z > 6. We study this effect by modeling the ionization and Ly α radiative transfer in the infall region and the IGM around a Ly α emitting galaxy (LAE), for a spherical halo model with the mean density and radialmore » velocity profiles in the standard ΛCDM cosmological scenario. We find that the expected fast increase of the ionizing background intensity toward the end of the reionization epoch implies a rapid evolution of halo infall regions from being self-shielded against the external ionizing background to being mostly ionized. Whereas self-shielded infall regions can scatter the Ly α photons over a much larger area than the commonly used apertures for observing LAEs, the same infalling gas is no longer optically thick to the Ly α emission line after it is ionized by the external background, making the Ly α emission more compact and brighter within the observed apertures. Based on this simple model, we show that the observed drop in the abundance of LAEs at z > 6 does not imply a rapid increase with redshift of the fraction of the whole IGM volume that is atomic, but is accounted for by a rapid increase of the neutral fraction in the infall regions around galaxy host halos.« less

Myeloid-derived suppressor cell functionality and interaction with Leishmania major parasites differ in C57BL/6 and BALB/c mice.

PubMed

Schmid, Maximilian; Zimara, Nicole; Wege, Anja Kathrin; Ritter, Uwe

2014-11-01

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of CD11b+ cells. According to the surface molecules Ly6G and Ly6C (where Ly6G and Ly6C are lymphocyte antigen 6, locus G and C, respectively), MDSCs are further divided into monocytic (Mo-MDSCs, CD11b+ /Ly6C(high) /Ly6G-) and polymorphonucleated suppressor cells (PMN-MDSCs, CD11b+ /Ly6C(int) /Ly6G+). Most published manuscripts focus on the suppressive role of MDSCs in cancer, whereas their impact on adaptive immunity against obligatory intracellular parasites is not well understood. Furthermore, it is not clear how the genetic background of mice influences MDSC functionality. Therefore, we implemented an experimental model of leishmaniasis, and analyzed MDSC maturation and the impact of MDSCs on the parasite-specific T-cell responses in resistant C57BL/6 and susceptible BALB/c mice. This experimental setup demonstrated the impaired ability of BALB/c mice to produce Mo-MDSCs when compared with C57BL/6 mice. This phenotype is detectable after subcutaneous infection with parasites and is specifically represented by a reduced accumulation of Mo-MDSCs at the site of infection in BALB/c mice. Moreover, infected C57BL/6-derived MDSCs were able to suppress Leishmania-specific CD4+ -cell proliferation, whereas BALB/c-derived MDSCs harboring parasites lost this suppressive function. In conclusion, we demonstrate that (i) genetic background defines MDSC differentiation; and (ii) Leishmania major parasites are able to modulate the suppressive effect of MDSCs in a strain-dependent manner. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Safety and Pharmacokinetics of the Antisense Oligonucleotide (ASO) LY2181308 as a Single-Agent or in Combination with Idarubicin and Cytarabine in Patients with Refractory or Relapsed Acute Myeloid Leukemia (AML)

PubMed Central

Erba, Harry P.; Sayar, Hamid; Juckett, Mark; Lahn, Michael; Andre, Valerie; Callies, Sophie; Schmidt, Shelly; Kadam, Sunil; Brandt, John T.; Van Bockstaele, Dirk; Andreeff, Michael

2014-01-01

Summary Survivin is expressed in tumor cells, including acute myeloid leukemia (AML), regulates mitosis, and prevents tumor cell death. The antisense oligonucleotide sodium LY2181308 (LY2181308) inhibits survivin expression and may cause cell cycle arrest and restore apoptosis in AML. Methods In this study, the safety, pharmacokinetics, and pharmacodynamics/efficacy of LY2181308 was examined in AML patients, first in a cohort with monotherapy (n=8) and then post-amendment in a cohort with the combination of cytarabine and idarubicin treatment (n=16). LY2181308 was administered with a loading dosage of 3 consecutive daily infusions of 750 mg followed by weekly intravenous (IV) maintenance doses of 750 mg. Cytarabine 1.5 g/m2 was administered as a 4-hour IV infusion on Days 3, 4, and 5 of Cycle 1, and idarubicin 12 mg/m2 was administered as a 30-minute IV infusion on Days 3, 4, and 5 of Cycle 1. Cytarabine and idarubicin were administered on Days 1, 2, and 3 of each subsequent 28-day cycle. Reduction of survivin was evaluated in peripheral blasts and bone marrow. Results Single-agent LY2181308 was well tolerated and survivin was reduced only in patients with a high survivin expression. In combination with chemotherapy, 4/16 patients had complete responses, 1/16 patients had incomplete responses, and 4/16 patients had cytoreduction. Nine patients died on study: 6 (monotherapy), 3 (combination). Conclusions LY2181308 alone is well tolerated in patients with AML. In combination with cytarabine and idarubicin, LY2181308 does not appear to cause additional toxicity, and has shown some clinical benefit needing confirmation in future clinical trials. PMID:23397500

A Close Relationship between Lyα and Mg II in Green Pea Galaxies

NASA Astrophysics Data System (ADS)

Henry, Alaina; Berg, Danielle A.; Scarlata, Claudia; Verhamme, Anne; Erb, Dawn

2018-03-01

The Mg II λλ2796, 2803 doublet is often used to measure interstellar medium absorption in galaxies, thereby serving as a diagnostic for feedback and outflows. However, the interpretation of Mg II remains confusing, due to resonant trapping and re-emission of the photons, analogous to Lyα. Therefore, in this paper, we present new MMT Blue Channel Spectrograph observations of Mg II for a sample of 10 Green Pea galaxies at z ∼ 0.2–0.3, where Lyα was previously observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope. With strong, (mostly) double-peaked Lyα profiles, these galaxies allow us to observe Mg II in the limit of low H I column density. We find strong Mg II emission and little-to-no absorption. We use photoionization models to show that nebular Mg II from H II regions is non-negligible, and the ratios of Mg II λλ2796, 2803/[O III] λ5007 versus [O III] λ5007/[O II] λ3727 form a tight sequence. Using this relation, we predict intrinsic Mg II flux, and show that Mg II escape fractions range from 0 to 0.9. We find that the Mg II escape fraction correlates tightly with the Lyα escape fraction, and the Mg II line profiles show evidence for broader and more redshifted emission when the escape fractions are low. These trends are expected if the escape fractions and velocity profiles of Lyα and Mg II are shaped by resonant scattering in the same low column density gas. As a consequence of a close relation with Lyα, Mg II may serve as a useful diagnostic in the epoch of reionization, where Lyα and Lyman continuum photons are not easily observed.

A Search for H I Lyα Counterparts to Ultrafast X-Ray Outflows

NASA Astrophysics Data System (ADS)

Kriss, Gerard A.; Lee, Julia C.; Danehkar, Ashkbiz

2018-06-01

Prompted by the H I Lyα absorption associated with the X-ray ultrafast outflow at ‑17,300 km s‑1 in the quasar PG 1211+143, we have searched archival UV spectra at the expected locations of H I Lyα absorption for a large sample of ultrafast outflows identified in XMM-Newton and Suzaku observations. Sixteen of the X-ray outflows have predicted H I Lyα wavelengths falling within the bandpass of spectra from either the Far Ultraviolet Spectroscopic Explorer or the Hubble Space Telescope, although none of the archival observations were simultaneous with the X-ray observations in which ultrafast X-ray outflows (UFOs) were detected. In our spectra broad features with FWHM of 1000 km s‑1 have 2σ upper limits on the H I column density of generally ≲2 × 1013 cm‑2. Using grids of photoionization models covering a broad range of spectral energy distributions (SEDs), we find that producing Fe XXVI Lyα X-ray absorption with equivalent widths >30 eV and associated H I Lyα absorption with {N}{{H}{{I}}}< 2× {10}13 {cm}}-2 requires total absorbing column densities {N}{{H}}> 5× {10}22 {cm}}-2 and ionization parameters log ξ ≳ 3.7. Nevertheless, a wide range of SEDs would predict observable H I Lyα absorption if ionization parameters are only slightly below peak ionization fractions for Fe XXV and Fe XXVI. The lack of Lyα features in the archival UV spectra indicates that the UFOs have very high ionization parameters, that they have very hard UV-ionizing spectra, or that they were not present at the time of the UV spectral observations owing to variability.

Lyα-emitting galaxies as a probe of reionization: large-scale bubble morphology and small-scale absorbers

NASA Astrophysics Data System (ADS)

Kakiichi, Koki; Dijkstra, Mark; Ciardi, Benedetta; Graziani, Luca

2016-12-01

The visibility of Lyα-emitting galaxies during the Epoch of Reionization is controlled by both diffuse H I patches in large-scale bubble morphology and small-scale absorbers. To investigate their impacts on Lyα transfer, we apply a novel combination of analytic modelling and cosmological hydrodynamical, radiative transfer simulations to three reionization models: (I) the `bubble' model, where only diffuse H I outside ionized bubbles is present; (II) the `web' model, where H I exists only in overdense self-shielded gas; and (III) the hybrid `web-bubble' model. The three models can explain the observed Lyα luminosity function equally well, but with very different H I fractions. This confirms a degeneracy between the ionization topology of the intergalactic medium (IGM) and the H I fraction inferred from Lyα surveys. We highlight the importance of the clustering of small-scale absorbers around galaxies. A combined analysis of the Lyα luminosity function and the Lyα fraction can break this degeneracy and provide constraints on the reionization history and its topology. Constraints can be improved by analysing the full MUV-dependent redshift evolution of the Lyα fraction of Lyman break galaxies. We find that the IGM-transmission probability distribution function is unimodal for bubble models and bimodal in web models. Comparing our models to observations, we infer that the neutral fraction at z ˜ 7 is likely to be of the order of tens of per cent when interpreted with bubble or web-bubble models, with a conservative lower limit ˜1 per cent when interpreted with web models.

Luminescence and scintillation properties of liquid phase epitaxy grown Y2SiO5:Ce single crystalline films

NASA Astrophysics Data System (ADS)

Wantong, Kriangkrai; Yawai, Nattasuda; Chewpraditkul, Weerapong; Kucera, Miroslav; Hanus, Martin; Nikl, Martin

2017-06-01

Luminescence and scintillation properties of Y2SiO5:Ce single crystalline film (YSO:Ce-LPE) grown by the liquid phase epitaxy technique are investigated and compared to the bulk Czochralski-grown YSO:Ce single crystal (YSO:Ce-SC). The light yield (LY) and energy resolution are measured using an R6231 photomultiplier under excitation with α - and γ- rays. At 662 keV γ- rays, the LY value of 12,410 ph/MeV obtained for YSO:Ce -LPE is lower than that of 20,150 ph/MeV for YSO:Ce -SC whereas the comparable LY value and energy resolution are obtained under excitation with 5.5 MeV α- rays. The ratio of LY under excitation with α- and γ- rays (α/γ ratio) is determined. Dependence of LY on an amplifier shaping time (0.5-12 μs) is also measured.

Photoredox Catalysis in a Complex Pharmaceutical Setting: Toward the Preparation of JAK2 Inhibitor LY2784544

PubMed Central

2015-01-01

We report a detailed investigation into the application of visible light-mediated photocatalysis to a challenging bond construction in a complex pharmaceutical target. The optimized reaction allowed the direct coupling of N-methylmorpholine with an unfunctionalized pyridazine in good yield and selectivity, and with high purity of the product isolated via crystallization. The reaction also facilitated the expedient synthesis of a range of analogues via the use of other commercially available N-methyl substituted tertiary amines, and therefore it represents an attractive tool for medicinal chemistry. Furthermore, a number of other interesting photoredox reactions were discovered during the course of this investigation, such as a formal methylation reaction via C–N bond cleavage, functionalization of C–H bonds alpha to amides, and a visible light-mediated iminium ion reduction. PMID:25356724

Spectrophotometry of Bowen resonance fluorescence lines in three planetary nebulae

NASA Technical Reports Server (NTRS)

O'Dell, C. R.; Miller, Christopher O.

1992-01-01

The results are presented of a uniquely complete, carefully reduced set of observations of the O III Bowen fluorescence lines in the planetary nebulae NGC 6210, NGC 7027, and NGC 7662. A detailed comparison with the predictions of radiative excitation verify that some secondary lines are enhanced by selective population by the charge exchange mechanism involving O IV. Charge exchange is most important in NGC 6210, which is of significantly lower ionization than the other nebulae. In addition to the principal Bowen lines arising from Ly-alpha pumping of the O III O1 line, lines arising from pumping of the O3 line are also observed. Comparison of lines produced by O1 and O3 with the theoretical predictions of Neufeld indicate poor agreement; comparison with the theoretical predictions of Harrington show agreement with NGC 7027 and NGC 7662.

CRITICAL STAR FORMATION RATES FOR REIONIZATION: FULL REIONIZATION OCCURS AT REDSHIFT z Almost-Equal-To 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael Shull, J.; Harness, Anthony; Trenti, Michele

We assess the probable redshift (z{sub rei} Almost-Equal-To 7) for full reionization of the intergalactic medium (IGM) using a prescription for the comoving star formation rate (SFR) density ({rho}-dot{sub SFR}) required to maintain photoionization against recombination. Our newly developed online reionization simulator allows users to assess the required SFR and ionization histories, using a variety of assumptions for galactic and stellar populations, IGM clumping factor and temperature, and Lyman continuum (LyC) escape fraction. The decline in high-redshift galaxy candidates and Ly{alpha} emitters at z = 6-8 suggests a rising neutral fraction, with reionization at z {approx}> 7 increasingly difficult owingmore » to increased recombination rates and constraints from the ionizing background and LyC mean free path. The required rate is {rho}-dot{sub SFR}{approx}(.018 M{sub sun}yr{sup -1}Mpc{sup -3})[(1+z)/8]{sup 3}(C{sub H}/3)(0.2/f{sub esc})T{sub 4}{sup -0.845} scaled to fiducial values of clumping factor C{sub H} = 3, escape fraction f{sub esc} = 0.2, electron temperature T{sub e} = 10{sup 4} K, and low-metallicity initial mass functions (IMFs) and stellar atmospheres. Our hydrodynamical + N-body simulations find a mean clumping factor C{sub H} Almost-Equal-To (2.9)[(1 + z)/6]{sup -1.1} in the photoionized, photoheated filaments at z = 5-9. The critical SFR could be reduced by increasing the minimum stellar mass, invoking a top-heavy IMF, or systematically increasing f{sub esc} at high z. The cosmic microwave background optical depth, {tau}{sub e} = 0.088 {+-} 0.015, could be explained by full reionization, producing {tau}{sub e} = 0.050 back to z{sub rei} Almost-Equal-To 7, augmented by {Delta}{tau}{sub e} Almost-Equal-To 0.01-0.04 in a partially ionized IGM at z > 7. In this scenario, the strongest 21 cm signal should occur at redshifted frequencies 124-167 MHz owing to IGM heating over an interval {Delta}z Almost-Equal-To 3 in the range z Almost-Equal-To 7.5-10.5.« less

THE BOSS EMISSION-LINE LENS SURVEY. IV. SMOOTH LENS MODELS FOR THE BELLS GALLERY SAMPLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, Yiping; Bolton, Adam S.; Montero-Dorta, Antonio D.

We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Ly α emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Ly α EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Ly α emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thoroughmore » exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ∼13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc.« less

Subregional localization and characterization of Ly6aGFP-expressing hematopoietic cells in the mouse embryonic head.

PubMed

Li, Zhuan; Vink, Chris S; Mariani, Samanta A; Dzierzak, Elaine

2016-08-01

Hematopoietic cell generation in the midgestation mouse embryo occurs through the natural transdifferentiation of temporally and spatially restricted set of hemogenic endothelial cells. These cells take on hematopoietic fate in the aorta, vitelline and umbilical arteries and appear as hematopoietic cell clusters that emerge from the vascular wall. Genetic and live imaging data have supported this. Recently, the embryonic head has been shown to contain fully functional hematopoietic stem cells (HSC). By lineage tracing, cerebrovascular specific endothelial cells were shown to contribute to the postnatal mouse hematopoietic system. Since Ly6aGFP is a marker of all HSCs, some hematopoietic cluster cells and hemogenic endothelial cells in the midgestation mouse aorta, we examine here whether embryonic head HSCs and vascular endothelial cells are positive for this marker. Whereas some head vasculature, single hematopoietic cells and all HSCs are Ly6aGFP expressing, we do not find clusters of hematopoietic cells emerging from the cerebrovasculature that are characteristic of endothelial-to-hematopoietic transition. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

An estimate of the prevalence of biocompatible and habitable planets.

PubMed

Fogg, M J

1992-01-01

A Monte Carlo computer model of extra-solar planetary formation and evolution, which includes the planetary geochemical carbon cycle, is presented. The results of a run of one million galactic disc stars are shown where the aim was to assess the possible abundance of both biocompatible and habitable planets. (Biocompatible planets are defined as worlds where the long-term presence of surface liquid water provides environmental conditions suitable for the origin and evolution of life. Habitable planets are those worlds with more specifically Earthlike conditions). The model gives an estimate of 1 biocompatible planet per 39 stars, with the subset of habitable planets being much rarer at 1 such planet per 413 stars. The nearest biocompatible planet may thus lie approximately 14 LY distant and the nearest habitable planet approximately 31 LY away. If planets form in multiple star systems then the above planet/star ratios may be more than doubled. By applying the results to stars in the solar neighbourhood, it is possible to identify 28 stars at distances of < 22 LY with a non-zero probability of possessing a biocompatible planet.

Hepatoprotective and antioxidant effects of lycopene on non-alcoholic fatty liver disease in rat.

PubMed

Jiang, Wei; Guo, Mei-Hua; Hai, Xin

2016-12-14

To evaluate the hepatoprotective effect of lycopene (Ly) on non-alcoholic fatty liver disease (NAFLD) in rat. A rat model of NAFLD was first established by feeding a high-fat diet for 14 wk. Sixty-five rats were randomly divided into normal group, model group and Ly treatment groups. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TG), total cholesterol (TC) in serum and low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), free fatty acid (FFA), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) in liver tissue were evaluated, respectively. While the hepatoprotective effect was also confirmed by histopathological analysis, the expression levels of TNF-α and cytochrome P 450 (CYP) 2E1 in rat liver were determined by immunohistochemistry analysis. A significant decrease was observed in the levels of serum AST (2.07-fold), ALT (2.95-fold), and the blood lipid TG (2.34-fold) and TC (1.66-fold) in the dose of 20 mg/kg Ly-treated rats ( P < 0.01), compared to the model group. Pretreatment with 5, 10 and 20 mg/kg of Ly significantly raised the levels of antioxidant enzyme SOD in a dose-dependent manner, to 90.95 ± 9.56, 109.52 ± 11.34 and 121.25 ± 10.68 ( P < 0.05, P < 0.01), as compared with the model group. Similarly, the levels of GSH were significantly increased ( P < 0.05, P < 0.01) after the Ly treatment. Meanwhile, pretreatment with 5, 10 and 20 mg/kg of Ly significantly reduced MDA amount by 30.87, 45.51 and 54.49% in the liver homogenates, respectively ( P < 0.01). The Ly treatment group showed significantly decreased levels of lipid products LDL-C ( P < 0.05, P < 0.01), improved HDL-C level and significantly decreased content of FFA, compared to the model group ( P < 0.05, P < 0.01). Furthermore, the Ly-treated group also exhibited a down-regulated TNF-α and CYP2E1 expression, decreased infiltration of liver fats and reversed histopathological changes, all in a dose-dependent manner ( P < 0.05, P < 0.01). This study suggests that Ly has a protective effect on NAFLD, down-regulates expression of TNF-α, and that CYP2E1 may be one of the action mechanisms for Ly.