The coma cluster after lunch: Has a galaxcy group passed through the cluster core?

NASA Technical Reports Server (NTRS)

Burns, Jack O.; Roettiger, Kurt; Ledlow, Michael; Klypin, Anatoly

1994-01-01

We propose that the Coma cluster has recently undergone a collision with the NGC 4839 galaxy group. The ROSAT X-ray morphology, the Coma radio halo, the presence of poststarburst galaxies in the bridge between Coma and NGC 4839, the usually high velocity dispersion for the NGC 4839 group, and the position of a large-scale galaxy filament to the NE of Coma are all used to argue that the NGC 4839 group passed through the core of Coma approximately 2 Gyr ago. We present a new Hydro/N-body simulation of the merger between a galaxy group and a rich cluster that reproduces many of the observed X-ray and optical properties of Coma/NGC 4839.

VizieR Online Data Catalog: HST/ACS Coma Cluster Survey. VI. (den Brok+, 2011)

NASA Astrophysics Data System (ADS)

den Brok, M.; Peletier, R. F.; Valentijn, E. A.; Balcells, M.; Carter, D.; Erwin, P.; Ferguson, H. C.; Goudfrooij, P.; Graham, A. W.; Hammer, D.; Lucey, J. R.; Trentham, N.; Guzman, R.; Hoyos, C.; Verdoes Kleijn, G.; Jogee, S.; Karick, A. M.; Marinova, I.; Mouhcine, M.; Weinzirl, T.

2018-01-01

We have used the data from the HST/ACS Coma Cluster Survey, a deep two-passband imaging survey of the Coma cluster. A full description of the observations and data reduction can be found in Paper I (Carter et al., 2008ApJS..176..424C). We have derived colour gradients for a sample of confirmed or very likely Coma cluster members. (2 data files).

Dwarf Galaxies in the Coma Cluster. II. Photometry and Analysis

NASA Astrophysics Data System (ADS)

Secker, J.; Harris, W. E.; Plummer, J. D.

1997-12-01

We use the data set derived in our previous paper (Secker & Harris 1997) to study the dwarf galaxy population in the central =~ 700 arcmin(2) of the Coma cluster, the majority of which are early-type dwarf elliptical (dE) galaxies. Analysis of the statistically-decontaminated dE galaxy sequence in the color-magnitude diagram reveals that the mean dE color at R = 18.0 mag is (B-R) =~ 1.4 mag, but that a highly significant trend of color with magnitude exists (Delta (B-R)/Delta R = -0.056+/-0.002 mag) in the sense that fainter dEs are bluer and thus presumably more metal-poor. The mean color of the faintest dEs in our sample is (B-R) =~ 1.15 mag, consistent with a color measurement of the diffuse intracluster light in the Coma core. This intracluster light could then have originated from the tidal disruption of faint dEs in the cluster core. The total galaxy luminosity function (LF) is well modeled as the sum of a log-normal distribution for the giant galaxies, and a Schechter function for the dE galaxies with a faint-end slope alpha = -1.41+/-0.05. This value of alpha is consistent with those measured for the Virgo and Fornax clusters. The spatial distribution of the faint dE galaxies (19.0 < R <= 22.5 mag) is well fit by a standard King model with a central surface density of Sigma_0 = 1.17 dEs arcmin(-2) and a core radius R_c = 22.15 arcmin ( =~ 0.46h(-1) Mpc). This core is significantly larger than the R_c = 13.71 arcmin ( =~ 0.29h(-1) Mpc) found for the cluster giants and the brighter dEs (R <= 19.0 mag), again consistent with the idea that faint dEs in the dense core have been disrupted. Finally, we find that most dEs belong to the general Coma cluster potential rather than as satellites of individual giant galaxies: An analysis of the number counts around 10 cluster giants reveals that they each have on average 4+/- 1 dE companions within a projected radius of 13.9h(-1) kpc. (SECTION: Galaxies)

FORTY-SEVEN MILKY WAY-SIZED, EXTREMELY DIFFUSE GALAXIES IN THE COMA CLUSTER

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

Van Dokkum, Pieter G.; Merritt, Allison; Geha, Marla

2015-01-10

We report the discovery of 47 low surface brightness objects in deep images of a 3° × 3° field centered on the Coma cluster, obtained with the Dragonfly Telephoto Array. The objects have central surface brightness μ(g, 0) ranging from 24-26 mag arcsec{sup –2} and effective radii r {sub eff} = 3''-10'', as measured from archival Canada-France-Hawaii Telescope images. From their spatial distribution we infer that most or all of the objects are galaxies in the Coma cluster. This relatively large distance is surprising as it implies that the galaxies are very large: with r {sub eff} = 1.5-4.6 kpcmore » their sizes are similar to those of L {sub *} galaxies even though their median stellar mass is only ∼6 × 10{sup 7} M {sub ☉}. The galaxies are relatively red and round, with (g – i) = 0.8 and (b/a) = 0.74. One of the 47 galaxies is fortuitously covered by a deep Hubble Space Telescope Advanced Camera for Surveys (ACS) observation. The ACS imaging shows a large spheroidal object with a central surface brightness μ{sub 475} = 25.8 mag arcsec{sup –2}, a Sérsic index n = 0.6, and an effective radius of 7'', corresponding to 3.4 kpc at the distance of Coma. The galaxy is not resolved into stars, consistent with expectations for a Coma cluster object. We speculate that these ''ultra-diffuse galaxies'' may have lost their gas supply at early times, possibly resulting in very high dark matter fractions.« less

Ram Pressure Stripping and Morphological Transformation in the Coma Cluster

NASA Astrophysics Data System (ADS)

Gregg, Michael; West, Michael

2017-01-01

The two largest spiral galaxies in the Coma cluster, NGC4911 and NGC4921, exhibit signs of being vigorously ram-pressure stripped by the hot intracluster medium. HST ACS and WFC3 images have revealed galactic scale shock fronts, giant "Pillars of Creation", rivulets of dust, and spatially coherent star formation in these grand design spirals. All evidence points to these galaxies being stressed by a global external source which can only be the hot intracluster medium (ICM). Inspired by these examples, we have obtained HST WFC3 imaging of five additional large spirals to search for and investigate the effects of ram pressure stripping across the wider Coma cluster. The results are equally spectacular as the first two examples. The geometry of the interactions in some cases allows us to estimate the various time scales involved, including gas flows out of the disk leading to creation of the ICM, and the attendant triggered star formation in the galaxy disks. The global star formation patterns and wholesale tidal stripping of matter yield insights into the spatial and temporal ISM-ICM interactions driving the evolution of galaxies in clusters and ultimately transforming their morphologies from spiral to S0. These processes, much more common in the early Universe, led to the wholesale morphological transformation of Hubble types during the assembly of rich clusters, when the intergalactic populations and hot ICM were first being created and laid down from such stripping and destruction of their member galaxies.We also report on two instrumental aspects of WFC3: 1) using the filter pair F350LP and F600LP to create an extremely broad pseudo Blue-Red color to achieve the greatest observing efficiency with HST, and 2) a WFC3 CCD effect which leads to apparent quantization of background counts, making automatic sky determination challenging when using drizzlepac routines.

The HST/ACS Coma Cluster Survey. II. Data Description and Source Catalogs

NASA Technical Reports Server (NTRS)

Hammer, Derek; Kleijn, Gijs Verdoes; Hoyos, Carlos; Den Brok, Mark; Balcells, Marc; Ferguson, Henry C.; Goudfrooij, Paul; Carter, David; Guzman, Rafael; Peletier, Reynier F.;

The origin of low mass particles within and beyond the dust coma envelopes of Comet Halley

NASA Technical Reports Server (NTRS)

Simpson, J. A.; Rabinowitz, D.; Tuzzolino, A. J.; Ksanfomality, L. V.; Sagdeev, R. Z.

1987-01-01

Measurements from the Dust Counter and Mass Analyzer (DUCMA) instruments on VEGA-1 and -2 revealed unexpected fluxes of low mass (up to 10 to the minus 13th power g) dust particles at very great distances from the nucleus (300,000 to 600,000 km). These particles are detected in clusters (10 sec duration), preceded and followed by relatively long time intervals during which no dust is detected. This cluster phenomenon also occurs inside the envelope boundaries. Clusters of low mass particles are intermixed with the overall dust distribution throughout the coma. The clusters account for many of the short-term small-scale intensity enhancements previously ascribed to microjets in the coma. The origin of these clusters appears to be emission from the nucleus of large conglomerates which disintegrate in the coma to yield clusters of discrete, small particles continuing outward to the distant coma.

The Radio Luminosity Function and Galaxy Evolution in the Coma Cluster

NASA Technical Reports Server (NTRS)

Miller, Neal A.; Hornschemeier, Ann E.; Mabasher, Bahram; Brudgesm Terrry J.; Hudson, Michael J.; Marzke, Ronald O.; Smith, Russell J.

2008-01-01

We investigate the radio luminosity function and radio source population for two fields within the Coma cluster of galaxies, with the fields centered on the cluster core and southwest infall region and each covering about half a square degree. Using VLA data with a typical rms sensitivity of 28 (mu)Jy per 4.4" beam, we identify 249 radio sources with optical counterparts brighter than r = 22 (equivalent to M(sub r) = -13 for cluster member galaxies). Comprehensive optical spectroscopy identifies 38 of these as members of the Coma cluster, evenly split between sources powered by an active nucleus and sources powered by active star formation. The radio-detected star-forming galaxies are restricted to radio luminosities between about 10(exp 21) and 10(exp 22) W/Hz, an interesting result given that star formation dominates field radio luminosity functions below about 10(exp 23) W/Hz. The majority of the radio-detected star-forming galaxies have characteristics of starbursts, including high specific star formation rates and optical spectra with strong emission lines. In conjunction with prior studies on post-starburst galaxies within the Coma cluster, this is consistent with a picture in which late-type galaxies entering Coma undergo a starburst prior to a rapid cessation of star formation. Optically bright elliptical galaxies (Mr less than or equals -20.5) make the largest contribution to the radio luminosity function at both the high (> approx. 3x10(exp 22) W/Hz) and low (< approx. 10(exp 21) W/Hz) ends. Through a stacking analysis of these optically-bright ellipticals we find that they continue to harbor radio sources down to luminosities as faint as 3x10(exp 19) W/Hz. However, contrary to published results for the Virgo cluster we find no evidence for the existence of a population of optically faint (M(sub r) approx. equals -14) dwarf ellipticals hosting strong radio AGN.

Comparative Study of Broadband Photometry Relations for Ultra-Diffuse and Normal Galaxies in the Coma Cluster

NASA Astrophysics Data System (ADS)

Stone, Maria Babakhanyan

Ultra-diffuse galaxies are a novel type of galaxies discovered first in the Coma cluster. These objects are characterized simultaneously by large sizes and by very low counts of constituent stars. Conflicting theories have been proposed to explain how these large diffuse galaxies could have survived in the harsh environment of clusters. To date, thousands of these new galaxies have been identified in cluster environments. However, further studies are required to understand their relationship to the known giant and dwarf classes of galaxies. The purpose of this study is to compare the trends of inner and outer populations of normal members of the Coma cluster and ultra-diffuse galaxies in color-magnitude space. The present work used several astronomical catalogs to identify the member galaxies based on the coordinates of their positions and to extract available colors and magnitudes. We obtained correlations to convert colors and magnitudes from different systems into the common Sloan Digital Sky Survey system to facilitate the comparative analysis. We showed the quantitative relations describing the color-magnitude trends of galaxies in the core and the outskirts of the cluster. We confirmed that the inner and outer populations of ultra-diffuse galaxies exhibit an offset similar to the normal red sequence galaxies. We presented an initial assessment of stellar population ages and metallicities which correspond to the obtained color offsets. We surveyed the available images of the cluster for outliers, merger candidates, and candidate ultra-diffuse galaxies. We conclude that ultra-diffuse galaxies are an important part of the Coma cluster evolutionary history and future work is needed especially in obtaining spectroscopic data of a larger number of these dim galaxies.

A Novel Approach to Constrain the Mass Ratio of Minor Mergers in Elliptical Galaxies: Application to NGC 4889, the Brightest Cluster Galaxy in Coma

NASA Astrophysics Data System (ADS)

Gu, Meng; Ho, Luis C.; Peng, Chien Y.; Huang, Song

2013-08-01

Minor mergers are thought to be important for the buildup and structural evolution of massive elliptical galaxies. In this work, we report the discovery of a system of four shell features in NGC 4889, one of the brightest members of the Coma cluster, using optical images taken with the Hubble Space Telescope and the Sloan Digital Sky Survey. The shells are well aligned with the major axis of the host and are likely to have been formed by the accretion of a small satellite galaxy. We have performed a detailed two-dimensional photometric decomposition of NGC 4889 and of the many overlapping nearby galaxies in its vicinity. This comprehensive model allows us not only to firmly detect the low-surface brightness shells, but, crucially, also to accurately measure their luminosities and colors. The shells are bluer than the underlying stars at the same radius in the main galaxy. We make use of the colors of the shells and the color-magnitude relation of the Coma cluster to infer the luminosity (or mass) of the progenitor galaxy. The shells in NGC 4889 appear to have been produced by the minor merger of a moderate-luminosity (MI ≈ -18.7 mag) disk (S0 or spiral) galaxy with a luminosity (mass) ratio of ~90:1 with respect to the primary galaxy. The novel methodology presented in this work can be exploited to decode the fossil record imprinted in the photometric substructure of other nearby early-type galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555.

A Dozen New Galaxies Caught in the Act: Gas Stripping and Extended Emission Line Regions in the Coma Cluster

NASA Astrophysics Data System (ADS)

Yagi, Masafumi; Yoshida, Michitoshi; Komiyama, Yutaka; Kashikawa, Nobunari; Furusawa, Hisanori; Okamura, Sadanori; Graham, Alister W.; Miller, Neal A.; Carter, David; Mobasher, Bahram; Jogee, Shardha

2010-12-01

We present images of extended Hα clouds associated with 14 member galaxies in the Coma cluster obtained from deep narrowband imaging observations with the Suprime-Cam at the Subaru Telescope. The parent galaxies of the extended Hα clouds are distributed farther than 0.2 Mpc from the peak of the X-ray emission of the cluster. Most of the galaxies are bluer than g - r ≈ 0.5 and they account for 57% of the blue (g - r < 0.5) bright (r < 17.8 mag) galaxies in the central region of the Coma cluster. They reside near the red- and blueshifted edges of the radial velocity distribution of Coma cluster member galaxies. Our findings suggest that most of the parent galaxies were recently captured by the Coma cluster potential and are now infalling toward the cluster center with their disk gas being stripped off and producing the observed Hα clouds. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Dark energy and the structure of the Coma cluster of galaxies

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Bisnovatyi-Kogan, G. S.; Teerikorpi, P.; Valtonen, M. J.; Byrd, G. G.; Merafina, M.

2013-05-01

Context. We consider the Coma cluster of galaxies as a gravitationally bound physical system embedded in the perfectly uniform static dark energy background as implied by ΛCDM cosmology. Aims: We ask if the density of dark energy is high enough to affect the structure of a large and rich cluster of galaxies. Methods: We base our work on recent observational data on the Coma cluster, and apply our theory of local dynamical effects of dark energy, including the zero-gravity radius RZG of the local force field as the key parameter. Results: 1) Three masses are defined that characterize the structure of a regular cluster: the matter mass MM, the dark-energy effective mass MDE (<0), and the gravitating mass MG (=MM + MDE). 2) A new matter-density profile is suggested that reproduces the observational data well for the Coma cluster in the radius range from 1.4 Mpc to 14 Mpc and takes the dark energy background into account. 3) Using this profile, we calculate upper limits for the total size of the Coma cluster, R ≤ RZG ≈ 20 Mpc, and its total matter mass, MM ≲ MM(RZG) = 6.2 × 1015 M⊙. Conclusions: The dark energy antigravity affects the structure of the Coma cluster strongly at large radii R ≳ 14 Mpc and should be considered when its total mass is derived.

Map-based trigonometric parallaxes of open clusters: Coma

NASA Technical Reports Server (NTRS)

Gatewood, George

1995-01-01

This is the fourth study in a series to determine the direct trigonometric parallaxes of four of the nearest open star clusters, the Hyades, the Pleiades, the Praesepe, and the nearby cluster in Coma (Gatewood et al. 1990; Gatewood et al. 1992); Gatewood & Kiewiet de Jonge 1994). The results for the open star cluster in Coma are compared with those of the other three clusters, and the members are found to be significantly subluminous. The trigonometric parallax of the cluster is estimated from that of three members studied with the Multichannel Astrometric Photometer (MAP) at the Thaw Refractor of the University of Pittsburgh's Allegheny Observatory. The weighted mean parallax of the cluster is +13.53 +/- 0.54 mass (0.00054 min), corresponding to a distance modulus of 4.34 +/- 0.09 mag. The U-B excess of the Coma cluster members may be used to adjust the observed absolute magnitudes and the B-V measurements as suggested by Sandage & Eggen (1959). The agreement obtained in this manner suggests that, like subdwarf stars, the stars of the Coma cluster appear subluminous because of line blanketing. One of the three members observed in this study was recognized as a member by its parallax and is the faintest known member of the cluster.

Map-based trigonometric parallaxes of open clusters: Coma

NASA Astrophysics Data System (ADS)

Gatewood, George

1995-06-01

This is the fourth study in a series to determine the direct trigonometric parallaxes of four of the nearest open star clusters, the Hyades, the Pleiades, the Praesepe, and the nearby cluster in Coma (Gatewood et al. 1990; Gatewood et al. 1992); Gatewood & Kiewiet de Jonge 1994). The results for the open star cluster in Coma are compared with those of the other three clusters, and the members are found to be significantly subluminous. The trigonometric parallax of the cluster is estimated from that of three members studied with the Multichannel Astrometric Photometer (MAP) at the Thaw Refractor of the University of Pittsburgh's Allegheny Observatory. The weighted mean parallax of the cluster is +13.53 +/- 0.54 mass (0.00054 min), corresponding to a distance modulus of 4.34 +/- 0.09 mag. The U-B excess of the Coma cluster members may be used to adjust the observed absolute magnitudes and the B-V measurements as suggested by Sandage & Eggen (1959). The agreement obtained in this manner suggests that, like subdwarf stars, the stars of the Coma cluster appear subluminous because of line blanketing. One of the three members observed in this study was recognized as a member by its parallax and is the faintest known member of the cluster.

VizieR Online Data Catalog: ETGs sample for the Coma cluster (Riguccini+, 2015)

NASA Astrophysics Data System (ADS)

Riguccini, L.; Temi, P.; Amblard, A.; Fanelli, M.; Brighenti, F.

2017-10-01

For the Coma Cluster, we utilize the work of Mahajan et al. (2010, J/MNRAS/404/1745) to build our ETG sample. Mahajan et al. (2010, J/MNRAS/404/1745) used a combination of MIPS 24 μm observations and SDSS photometry and spectra to investigate the star formation history of galaxies in the Coma supercluster. All of their galaxies from the SDSS data in the Coma supercluster region are brighter than r~17.77, the completeness limit of the SDSS spectroscopic galaxy catalog. Their 24 μm fluxes are obtained from archival data covering 2x2 deg2 for Coma Cluster. Our final sample of 124 sources is composed of 49 ellipticals and 75 lenticulars. (1 data file).

Coma cluster of galaxies

NASA Image and Video Library

1999-12-02

Atlas Image mosaic, covering 34 x 34 on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies over 1000 members, most prominently the two giant ellipticals, NGC 4874 right and NGC 4889 left.

VizieR Online Data Catalog: Galaxies morphology and IR photometry III. (Gavazzi+, 2000)

NASA Astrophysics Data System (ADS)

Gavazzi, G.; Franzetti, P.; Scodeggio, M.; Boselli, A.; Pierini, D.; Baffa, C.; Lisi, F.; Hunt, L. K.

1999-11-01

We present near-infrared H-band (1.65μm) surface photometry of 558 galaxies in the Coma Supercluster and in the Virgo cluster. This data set, obtained with the Arcetri NICMOS3 camera ARNICA mounted on the Gornergrat Infrared Telescope, is aimed at complementing, with observations of mostly early-type objects, our NIR survey of spiral galaxies in these regions, presented in previous papers of this series. Magnitudes at the optical radius, total magnitudes, isophotal radii and light concentration indices are derived. We confirm the existence of a positive correlation between the near-infrared concentration index and the galaxy H-band luminosity (2 data files).

Another collision for the Coma cluster

NASA Technical Reports Server (NTRS)

Vikhlinin, A.; Forman, W.; Jones, C.

1996-01-01

The wavelet transform analysis of the Rosat position sensitive proportional counter (PSPC) images of the Coma cluster are presented. The analysis shows, on small scales, a substructure dominated by two extended sources surrounding the two bright clusters NGC 4874 and NGC 4889. On scales of about 2 arcmin to 3 arcmin, the analysis reveals a tail of X-ray emission originating near the cluster center, curving to the south and east for approximately 25 arcmin and ending near the galaxy NGC 4911. The results are interpreted in terms of a merger of a group, having a core mass of approximately 10(exp 13) solar mass, with the main body of the Coma cluster.

The Nature and Origin of UCDs in the Coma Cluster

NASA Astrophysics Data System (ADS)

Chiboucas, Kristin; Tully, R. Brent; Madrid, Juan; Phillipps, Steven; Carter, David; Peng, Eric

2018-01-01

UCDs are super massive star clusters found largely in dense regions but have also been found around individual galaxies and in smaller groups. Their origin is still under debate but currently favored scenarios include formation as giant star clusters, either as the brightest globular clusters or through mergers of super star clusters, themselves formed during major galaxy mergers, or as remnant nuclei from tidal stripping of nucleated dwarf ellipticals. Establishing the nature of these enigmatic objects has important implications for our understanding of star formation, star cluster formation, the missing satellite problem, and galaxy evolution. We are attempting to disentangle these competing formation scenarios with a large survey of UCDs in the Coma cluster. Using ACS two-passband imaging from the HST/ACS Coma Cluster Treasury Survey, we are using colors and sizes to identify the UCD cluster members. With a large size limited sample of the UCD population within the core region of the Coma cluster, we are investigating the population size, properties, and spatial distribution, and comparing that with the Coma globular cluster and nuclear star cluster populations to discriminate between the threshing and globular cluster scenarios. In previous work, we had found a possible correlation of UCD colors with host galaxy and a possible excess of UCDs around a non-central giant galaxy with an unusually large globular cluster population, both suggestive of a globular cluster origin. With a larger sample size and additional imaging fields that encompass the regions around these giant galaxies, we have found that the color correlation with host persists and the giant galaxy with unusually large globular cluster population does appear to host a large UCD population as well. We present the current status of the survey.

DARK MATTER SUBHALOS AND THE X-RAY MORPHOLOGY OF THE COMA CLUSTER

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

Andrade-Santos, Felipe; Nulsen, Paul E. J.; Kraft, Ralph P.

2013-04-01

Structure formation models predict that clusters of galaxies contain numerous massive subhalos. The gravity of a subhalo in a cluster compresses the surrounding intracluster gas and enhances its X-ray emission. We present a simple model, which treats subhalos as slow moving and gasless, for computing this effect. Recent weak lensing measurements by Okabe et al. have determined masses of {approx}10{sup 13} M{sub Sun} for three mass concentrations projected within 300 kpc of the center of the Coma Cluster, two of which are centered on the giant elliptical galaxies NGC 4889 and NGC 4874. Adopting a smooth spheroidal {beta}-model for themore » gas distribution in the unperturbed cluster, we model the effect of these subhalos on the X-ray morphology of the Coma Cluster, comparing our results to Chandra and XMM-Newton X-ray data. The agreement between the models and the X-ray morphology of the central Coma Cluster is striking. With subhalo parameters from the lensing measurements, the distances of the three subhalos from the Coma Cluster midplane along our line of sight are all tightly constrained. Using the model to fit the subhalo masses for NGC 4889 and NGC 4874 gives 9.1 Multiplication-Sign 10{sup 12} M{sub Sun} and 7.6 Multiplication-Sign 10{sup 12} M{sub Sun }, respectively, in good agreement with the lensing masses. These results lend strong support to the argument that NGC 4889 and NGC 4874 are each associated with a subhalo that resides near the center of the Coma Cluster. In addition to constraining the masses and 3-d location of subhalos, the X-ray data show promise as a means of probing the structure of central subhalos.« less

THE GALAXY LUMINOSITY FUNCTIONS DOWN TO M{sub R} = -10 IN THE COMA CLUSTER

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

Yamanoi, Hitomi; Komiyama, Yutaka; Yagi, Masafumi

2012-08-15

We derived the luminosity function (LF) of dwarf galaxies in the Coma Cluster down to M{sub R} = -10 at three fields located at the center, intermediate, and outskirt of the cluster. The LF (-19 < M{sub R} < -10) shows no significant differences among the three fields. It shows a clear dip at M{sub R} {approx} -13 and is composed of two distinct components of different slopes; the bright component with -19 < M{sub R} < -13 has a flatter slope than the faint component with -13 < M{sub R} < -10 which has a steep slope. The brightmore » component (-19 < M{sub R} < -13) consists mostly of red extended galaxies including few blue galaxies whose colors are typical of late-type galaxies. On the other hand, the faint component (-13 < M{sub R} < -10) consists largely of point-spread-function-like compact galaxies. We found that both these compact galaxies and some extended galaxies are present in the center while only compact galaxies are seen in the outskirt. In the faint component, the fraction of blue galaxies is larger in the outskirt than in the center. We suggest that the dwarf galaxies in the Coma Cluster, which make up the two components in the LF, are heterogeneous with some different origins.« less

Dwarf galaxies in the coma cluster: Star formation properties and evolution

NASA Astrophysics Data System (ADS)

Hammer, Derek M.

The infall regions of galaxy clusters are unique laboratories for studying the impact of environment on galaxy evolution. This intermediate region links the low-density field environment and the dense core of the cluster, and is thought to host recently accreted galaxies whose star formation is being quenched by external processes associated with the cluster. In this dissertation, we measure the star formation properties of galaxies at the infall region of the nearby rich cluster of galaxies, Coma. We rely primarily on Ultraviolet (UV) data owing to its sensitivity to recent star formation and we place more emphasis on the properties of dwarf galaxies. Dwarf galaxies are good tracers of external processes in clusters but their evolution is poorly constrained as they are intrinsically faint and hence more challenging to detect. We make use of deep GALEX far-UV and near-UV observations at the infall region of the Coma cluster. This area of the cluster has supporting photometric coverage at optical and IR wavelengths in addition to optical spectroscopic data that includes deep redshift coverage of dwarf galaxies in Coma. Our GALEX observations were the deepest exposures taken for a local galaxy cluster. The depth of these images required alternative data analysis techniques to overcome systematic effects that limit the default GALEX pipeline analysis. Specifically, we used a deblending method that improved detection efficiency by a factor of ˜2 and allowed reliable photometry a few magnitudes deeper than the pipeline catalog. We performed deep measurements of the total UV galaxy counts in our field that were used to measure the source confusion limit for crowded GALEX fields. The star formation properties of Coma members were studied for galaxies that span from starbursts to passive galaxies. Star-forming galaxies in Coma tend to have lower specific star formation rates, on average, as compared to field galaxies. We show that the majority of these galaxies are likely in the process of being quenched or were only recently quenched. We modeled the quenching timescales for transition galaxies, or “green valley” objects, and found that the majority are quenched in less than 1 Gyr. This timescale is consistent with rapid dynamical processes that are active in the cluster environment as opposed to the more gradual quenching mechanisms that exist in the group environment. For the passive galaxy population, we have measured an average stellar age of 6-8 Gyr for the red sequence which is consistent with previous studies based on spectroscopic observations. We note that the star formation properties of Coma member galaxies were established from photometry alone, as opposed to using spectroscopic data which are more challenging to obtain for dwarf galaxies. We have measured the faintest UV luminosity functions (LFs) presented for a rich galaxy cluster thus far. The Coma UV LFs are 3.5 mag fainter than previous studies in Coma, and are sufficiently deep that we reach the dwarf passive galaxy population for the first time. We have introduced a new technique for measuring the LF which avoids color selection effects associated with previous methods. The UV LFs constructed separately for star-forming and passive galaxies follow a similar distribution at faint magnitudes, which suggests that the recent quenching of infalling dwarf star-forming galaxies is sufficient to build the dwarf passive population in Coma. The Coma UV LFs show a turnover at faint magnitudes as compared to the field, owing to a deficit of dwarf galaxies with stellar masses below M∗ = 108 M⊙ . We show that the UV LFs for the field behind the Coma cluster are nearly identical to the average field environment, and do not show evidence for a turnover at faint magnitudes. We suspect that the missing dwarf galaxies in Coma are severely disrupted by tidal processes as they are accreted onto the cluster, just prior to reaching the infall region studied here.

Spectral constraints on models of gas in clusters of galaxies

NASA Technical Reports Server (NTRS)

Henriksen, M. J.; Mushotzky, R.

1985-01-01

The HEAO 1A2 spectra of clusters of galaxies are used to determine the temperature profile which characterizes the X-ray emitting gas. Strong evidence of nonisothermality is found for the Coma, A85, and A1795 clusters. Properties of the cluster potential which binds the gas are calculated for a range of model parameters. The typical binding mass, if the gas is adiabatic, is 2-4E14 solar masses and is quite centrally concentrated. In addition, the Fe abundance in Coma is .26 + or - .06 solar, less than the typical value (.5) found for rich clusters. The results for the gas in Coma may imply a physical description of the cluster which is quite different from what was previously believed.

Elemental Abundances in the Intracluster Gas and the Hot Galactic Coronae in Cluster A194

NASA Technical Reports Server (NTRS)

Forman, William R.

1997-01-01

We have completed the analysis of observations of the Coma cluster and are continuing analysis of A1367 both of which are shown to be merging clusters. Also, we are analyzing observations of the Centaurus cluster which we see as a merger based in both its temperature and surface brightness distributions. Attachment: Another collision for the coma cluster.

Characterization of the warm-hot intergalactic medium near the Coma cluster through high-resolution spectroscopy of X Comae

NASA Astrophysics Data System (ADS)

Bonamente, M.; Ahoranta, J.; Tilton, E.; Tempel, E.; Morandi, A.

2017-08-01

We have analysed all available archival XMM-Newton observations of X Comae, a bright X-ray quasar behind the Coma cluster, to study the properties of the warm-hot intergalactic medium (WHIM) in the vicinity of the nearest massive galaxy cluster. The reflection grating spectrometer observations confirm the possible presence of a Ne ix K α absorption line at the redshift of Coma, although with a limited statistical significance. This analysis is therefore in line with the earlier analysis by Takei et al. based on a sub-set of these data. Its large column density and optical depth, however, point to implausible conditions for the absorbing medium, thereby casting serious doubts to its reality. Chandra has never observed X Comae and therefore cannot provide additional information on this source. We combine upper limits to the presence of other X-ray absorption lines (notably from O vii and O viii) at the redshift of Coma with positive measurements of the soft excess emission from Coma measured by ROSAT (Bonamente et al.). The combination of emission from warm-hot gas at kT ˜ 1/4 keV and upper limits from absorption lines provide useful constraints on the density and the sightline length of the putative WHIM towards Coma. We conclude that the putative warm-hot medium towards Coma is consistent with expected properties, with a baryon overdensity δb ≥ 10 and a sightline extent of order of tens of Mpc.

VizieR Online Data Catalog: Coma clusters and filaments galaxies FIR survey (Fuller+, 2016)

NASA Astrophysics Data System (ADS)

Fuller, C.; Davies, J. I.; Smith, M. W. L.; Valiante, E.; Eales, S.; Bourne, N.; Dunne, L.; Dye, S.; Furlanetto, C.; Ibar, E.; Ivison, R.; Maddox, S.; Sansom, A.; Michalowski, M. J.; Davis, T.

2017-05-01

We have undertaken a Herschel FIR survey of the Coma cluster and the galaxy filament it resides within. Our survey covers an area of ~150 deg2 observed in five bands at 100, 160, 250, 350 and 500um. We have used the SDSS spectroscopic survey to define an area and redshift selected sample of 744 Coma cluster galaxies - the CCC. For comparison, we also define in a similar way a sample of 951 galaxies in the connecting filament - the CFC. (2 data files).

Long-term outcomes after immediate aortic repair for acute type A aortic dissection complicated by coma.

PubMed

Tsukube, Takuro; Haraguchi, Tomonori; Okada, Yasushi; Matsukawa, Ritsu; Kozawa, Shuichi; Ogawa, Kyoichi; Okita, Yutaka

2014-09-01

The management of acute type A aortic dissection complicated by coma remains controversial. We previously reported an excellent rate of recovery of consciousness provided aortic repair was performed within 5 hours of the onset of symptoms. This study evaluates the early and long-term outcomes using this approach. Between August 2003 and July 2013, of the 241 patients with acute type A aortic dissection brought to the Japanese Red Cross Kobe Hospital and Hyogo Emergency Medical Center, 30 (12.4%) presented with coma; Glasgow Coma Scale was less than 11 on arrival. Surgery was performed in 186 patients, including 27 (14.5%) who were comatose. Twenty-four comatose patients underwent successful aortic repair immediately (immediate group). Their mean age was 71.0 ± 11.1 years, Glasgow Coma Scale was 6.5 ± 2.4, and prevalence of carotid dissection was 79%. For brain protection, deep hypothermia with antegrade cerebral perfusion was used, and postoperative induced hypothermia was performed. Neurologic evaluations were performed using the Glasgow Coma Scale, National Institutes of Health Stroke Scale, and modified Rankin Scale. In the immediate group, the time from the onset of symptoms to arrival in the operating theater was 222 ± 86 minutes. Hospital mortality was 12.5%. Full recovery of consciousness was achieved in 79% of patients in up to 30 days. Postoperative Glasgow Coma Scale and National Institutes of Health Stroke Scale improved significantly when compared with the preoperative score (P < .05), and postoperative activities of daily living independence (modified Rankin Scale <3) was achieved in 50% of patients. The mean follow-up period was 56.5 months, and the cumulative survival was 48.2% after 10 years. Cox proportional hazards regression analysis indicated that immediate repair (hazard ratio, 4.3; P = .007) was the only significant predictor of postoperative survival over a 5-year period. The early and long-term outcomes as a result of immediate aortic repair for acute type A aortic dissection complicated by coma were satisfactory. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

CONSTRAINTS ON COSMIC RAYS, MAGNETIC FIELDS, AND DARK MATTER FROM GAMMA-RAY OBSERVATIONS OF THE COMA CLUSTER OF GALAXIES WITH VERITAS AND FERMI

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

Arlen, T.; Aune, T.; Bouvier, A.

2012-10-01

Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated and, on account of weak energy losses, can accumulate, suggesting that clusters may also be sources of very high energy (VHE; E > 100 GeV) gamma-ray emission. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. No significant gamma-ray emission from the Coma Cluster was detected. Integral flux upper limits at the 99% confidence level were measured to be on themore » order of (2-5) Multiplication-Sign 10{sup -8} photons m {sup -2} s {sup -1} (VERITAS, >220 GeV) and {approx}2 Multiplication-Sign 10{sup -6} photons m {sup -2} s {sup -1} (Fermi, 1-3 GeV), respectively. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be <16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Assuming that the radio-emitting electrons of the Coma halo result from hadronic CR interactions, the observations imply a lower limit on the central magnetic field in Coma of {approx}(2-5.5) {mu}G, depending on the radial magnetic field profile and on the gamma-ray spectral index. Since these values are below those inferred by Faraday rotation measurements in Coma (for most of the parameter space), this renders the hadronic model a very plausible explanation of the Coma radio halo. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, ({sigma}v).« less

Constraints on Cosmic Rays, Magnetic Fields, and Dark Matter from Gamma-ray Observations of the Coma Cluster of Galaxies with VERITAS and FERMI

NASA Technical Reports Server (NTRS)

Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.;

A SUZAKU SEARCH FOR NONTHERMAL EMISSION AT HARD X-RAY ENERGIES IN THE COMA CLUSTER

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

Wik, Daniel R.; Sarazin, Craig L.; Finoguenov, Alexis

2009-05-10

The brightest cluster radio halo known resides in the Coma cluster of galaxies. The relativistic electrons producing this diffuse synchrotron emission should also produce inverse Compton emission that becomes competitive with thermal emission from the intracluster medium (ICM) at hard X-ray energies. Thus far, claimed detections of this emission in Coma are controversial. We present a Suzaku HXD-PIN observation of the Coma cluster in order to nail down its nonthermal hard X-ray content. The contribution of thermal emission to the HXD-PIN spectrum is constrained by simultaneously fitting thermal and nonthermal models to it and a spatially equivalent spectrum derived frommore » an XMM-Newton mosaic of the Coma field. We fail to find statistically significant evidence for nonthermal emission in the spectra which are better described by only a single- or multitemperature model for the ICM. Including systematic uncertainties, we derive a 90% upper limit on the flux of nonthermal emission of 6.0 x 10{sup -12} erg s{sup -1} cm{sup -2} (20-80 keV, for {gamma} = 2.0), which implies a lower limit on the cluster-averaged magnetic field of B>0.15 {mu}G. Our flux upper limit is 2.5 times lower than the detected nonthermal flux from RXTE and BeppoSAX. However, if the nonthermal hard X-ray emission in Coma is more spatially extended than the observed radio halo, the Suzaku HXD-PIN may miss some fraction of the emission. A detailed investigation indicates that {approx}50%-67% of the emission might go undetected, which could make our limit consistent with that of Rephaeli and Gruber and Fusco-Femiano et al. The thermal interpretation of the hard Coma spectrum is consistent with recent analyses of INTEGRAL and Swift data.« less

The Coma Cluster Luminosity Function from Ultraviolet to Near-Infrared

NASA Astrophysics Data System (ADS)

Andreon, S.; Cuillandre, J.-C.; Pello, R.

The Coma cluster luminosity function (LF) from ultraviolet (2000 AA ) to the near-infrared (H band) is summarized. In the UV the LF is very steep, much steeper than in the optical. The steep Coma UV LF implies that faint and bright galaxies give similar contributions to the total UV flux and to the total metal production rate. The ComaUV LF is dominated in number and luminosity by blue galaxies, which are often faint in the optical. Therefore the Coma UV LF is dominated by star forming galaxies, not by massive and large galaxies. The optical Coma LF is relatively steep (alpha=-1.4) over the 11 magnitudes sampled, but its slope and shape depend on considered filter and magnitude. We found a clear steeping of the FL going from B to R bands, indicative of the presence of a large number of red dwarfs, as faint as three bright globular clusters. Furthermore, using Hubble Space Telescope images, we discover that blends of globular clusters, not resolved in individual components due to seeing, look like dwarf galaxies when observed from the ground and are numerous and bright. The existence of these fake extended sources increases the steepness of the LF at faint magnitudes, if not deal on. This concern affects previous deep probing of the luminosity function, but not the present work. The near-infrared LF wa s computed on a near-infrared selected sample of galaxies which photometry is complete down to the typical dwarf (M* +5) luminosity. The Coma LF can be described by a Schechter function with intermediate slope (alpha sim-1.3), plus a dip at MH~-22 mag. The shape of the Coma LF in H band is quite similar to th e one found in the B band. The similarity of the LF in the optical and H bands implies that in the central region of Coma there is no new population of galaxies which is too faint to be observed in the optical band (because dust enshrouded, for instance), down to the magnitudes of dwarfs. The exponential cut of the LF at the bright end is in good agreement with the one derived from shallower near-infrared samples o f galaxies, both in clusters and in the field. The faint end of the LF, reaching MH~-19 mag (roughly MB~ -15), is steep, but less than previously suggested from shallower near-infrared observations of an adjacent region in the Coma cluster.

Galaxy Interactions, Tidal Debris, and the Origin of Intracluster Light in the Coma Cluster

NASA Astrophysics Data System (ADS)

Gregg, Michael

1999-07-01

We propose to obtain deep WFPC2 and parallel STIS images of low surface brightness tidal debris that we have recently discovered in the Coma cluster; the material is being stripped from its parent galaxy and added to the general cluster background. These images will enable direct study of the brightest blue and red supergiants, globular clusters, and star forming regions which may be present, or will place strong limits on the numbers of such objects and any recent star formation. We also propose similar observations of the parent spiral, NGC4911, in the core of Coma; it is losing its ISM to the hot cluster gas and as well as the low surface brightness tidal debris. By imaging this galaxy, we will get a high resolution look at the interaction between the galaxy and interstellar medium, as well as any ram-pressure induced star formation. The tidal features in Coma appear to be adding material to the background light and cD galaxy envelopes at a significant rate; determining the nature of the added stellar population and the interactions which produce it are critical to understanding the formation and evolution of cD galaxies and clusters.

Coma cluster of galaxies

NASA Technical Reports Server (NTRS)

1999-01-01

Atlas Image mosaic, covering 34' x 34' on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies (over 1000 members), most prominently the two giant ellipticals, NGC 4874 (right) and NGC 4889 (left). The remaining members are mostly smaller ellipticals, but spiral galaxies are also evident in the 2MASS image. The cluster is seen toward the constellation Coma Berenices, but is actually at a distance of about 100 Mpc (330 million light years, or a redshift of 0.023) from us. At this distance, the cluster is in what is known as the 'Hubble flow,' or the overall expansion of the Universe. As such, astronomers can measure the Hubble Constant, or the universal expansion rate, based on the distance to this cluster. Large, rich clusters, such as Coma, allow astronomers to measure the 'missing mass,' i.e., the matter in the cluster that we cannot see, since it gravitationally influences the motions of the member galaxies within the cluster. The near-infrared maps the overall luminous mass content of the member galaxies, since the light at these wavelengths is dominated by the more numerous older stellar populations. Galaxies, as seen by 2MASS, look fairly smooth and homogeneous, as can be seen from the Hubble 'tuning fork' diagram of near-infrared galaxy morphology. Image mosaic by S. Van Dyk (IPAC).

ALP conversion and the soft X-ray excess in the outskirts of the Coma cluster

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

Kraljic, David; Rummel, Markus; Conlon, Joseph P., E-mail: David.Kraljic@physics.ox.ac.uk, E-mail: Markus.Rummel@physics.ox.ac.uk, E-mail: j.conlon1@physics.ox.ac.uk

2015-01-01

It was recently found that the soft X-ray excess in the center of the Coma cluster can be fitted by conversion of axion-like-particles (ALPs) of a cosmic axion background (CAB) to photons. We extend this analysis to the outskirts of Coma, including regions up to 5 Mpc from the center of the cluster. We extract the excess soft X-ray flux from ROSAT All-Sky Survey data and compare it to the expected flux from ALP to photon conversion of a CAB. The soft X-ray excess both in the center and the outskirts of Coma can be simultaneously fitted by ALP tomore » photon conversion of a CAB. Given the uncertainties of the cluster magnetic field in the outskirts we constrain the parameter space of the CAB. In particular, an upper limit on the CAB mean energy and a range of allowed ALP-photon couplings are derived.« less

THE HST/ACS COMA CLUSTER SURVEY. VIII. BARRED DISK GALAXIES IN THE CORE OF THE COMA CLUSTER

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

Marinova, Irina; Jogee, Shardha; Weinzirl, Tim

2012-02-20

We use high-resolution ({approx}0.''1) F814W Advanced Camera for Surveys (ACS) images from the Hubble Space Telescope ACS Treasury survey of the Coma cluster at z {approx} 0.02 to study bars in massive disk galaxies (S0s), as well as low-mass dwarf galaxies in the core of the Coma cluster, the densest environment in the nearby universe. Our study helps to constrain the evolution of bars and disks in dense environments and provides a comparison point for studies in lower density environments and at higher redshifts. Our results are: (1) we characterize the fraction and properties of bars in a sample ofmore » 32 bright (M{sub V} {approx}< -18, M{sub *} > 10{sup 9.5} M{sub Sun }) S0 galaxies, which dominate the population of massive disk galaxies in the Coma core. We find that the measurement of a bar fraction among S0 galaxies must be handled with special care due to the difficulty in separating unbarred S0s from ellipticals, and the potential dilution of the bar signature by light from a relatively large, bright bulge. The results depend sensitively on the method used: the bar fraction for bright S0s in the Coma core is 50% {+-} 11%, 65% {+-} 11%, and 60% {+-} 11% based on three methods of bar detection, namely, strict ellipse fit criteria, relaxed ellipse fit criteria, and visual classification. (2) We compare the S0 bar fraction across different environments (the Coma core, A901/902, and Virgo) adopting the critical step of using matched samples and matched methods in order to ensure robust comparisons. We find that the bar fraction among bright S0 galaxies does not show a statistically significant variation (within the error bars of {+-}11%) across environments which span two orders of magnitude in galaxy number density (n {approx} 300-10,000 galaxies Mpc{sup -3}) and include rich and poor clusters, such as the core of Coma, the A901/902 cluster, and Virgo. We speculate that the bar fraction among S0s is not significantly enhanced in rich clusters compared to low-density environments for two reasons. First, S0s in rich clusters are less prone to bar instabilities as they are dynamically heated by harassment and are gas poor as a result of ram pressure stripping and accelerated star formation. Second, high-speed encounters in rich clusters may be less effective than slow, strong encounters in inducing bars. (3) We also take advantage of the high resolution of the ACS ({approx}50 pc) to analyze a sample of 333 faint (M{sub V} > -18) dwarf galaxies in the Coma core. Using visual inspection of unsharp-masked images, we find only 13 galaxies with bar and/or spiral structure. An additional eight galaxies show evidence for an inclined disk. The paucity of disk structures in Coma dwarfs suggests that either disks are not common in these galaxies or that any disks present are too hot to develop instabilities.« less

VizieR Online Data Catalog: Subaru-UDGs in the Coma cluster (Yagi+, 2016)

NASA Astrophysics Data System (ADS)

Yagi, M.; Koda, J.; Komiyama, Y.; Yamanoi, H.

2016-10-01

We retrieved a wide W-C-RC band (R-band) survey of the Coma cluster of Suprime-Cam from the Subaru public archive (SMOKA; Baba et al. 2002ASPC..281..298B) between 2011 Mar 02 and 2011 Apr 01. (1 data file).

Soft X-ray excess in the Coma cluster from a Cosmic Axion Background

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

Angus, Stephen; Conlon, Joseph P.; Marsh, M.C. David

2014-09-01

We show that the soft X-ray excess in the Coma cluster can be explained by a cosmic background of relativistic axion-like particles (ALPs) converting into photons in the cluster magnetic field. We provide a detailed self-contained review of the cluster soft X-ray excess, the proposed astrophysical explanations and the problems they face, and explain how a 0.1- 1 keV axion background naturally arises at reheating in many string theory models of the early universe. We study the morphology of the soft excess by numerically propagating axions through stochastic, multi-scale magnetic field models that are consistent with observations of Faraday rotation measuresmore » from Coma. By comparing to ROSAT observations of the 0.2- 0.4 keV soft excess, we find that the overall excess luminosity is easily reproduced for g{sub aγγ} ∼ 2 × 10{sup -13} Ge {sup -1}. The resulting morphology is highly sensitive to the magnetic field power spectrum. For Gaussian magnetic field models, the observed soft excess morphology prefers magnetic field spectra with most power in coherence lengths on O(3 kpc) scales over those with most power on O(12 kpc) scales. Within this scenario, we bound the mean energy of the axion background to 50 eV∼< ( E{sub a} ) ∼< 250 eV, the axion mass to m{sub a} ∼< 10{sup -12} eV, and derive a lower bound on the axion-photon coupling g{sub aγγ} ∼> √(0.5/Δ N{sub eff}) 1.4 × 10{sup -13} Ge {sup -1}.« less

Star formation and galaxy evolution in different environments, from the field to massive clusters

NASA Astrophysics Data System (ADS)

Tyler, Krystal

This thesis focuses on how a galaxy's environment affects its star formation, from the galactic environment of the most luminous IR galaxies in the universe to groups and massive clusters of galaxies. Initially, we studied a class of high-redshift galaxies with extremely red optical-to-mid-IR colors. We used Spitzer spectra and photometry to identify whether the IR outputs of these objects are dominated by AGNs or star formation. In accordance with the expectation that the AGN contribution should increase with IR luminosity, we find most of our very red IR-luminous galaxies to be dominated by an AGN, though a few appear to be star-formation dominated. We then observed how the density of the extraglactic environment plays a role in galaxy evolution. We begin with Spitzer and HST observations of intermediate-redshift groups. Although the environment has clearly changed some properties of its members, group galaxies at a given mass and morphology have comparable amounts of star formation as field galaxies. We conclude the main difference between the two environments is the higher fraction of massive early-type galaxies in groups. Clusters show even more distinct trends. Using three different star-formation indicators, we found the mass-SFR relation for cluster galaxies can look similar to the field (A2029) or have a population of low-star-forming galaxies in addition to the field-like galaxies (Coma). We contribute this to differing merger histories: recently-accreted galaxies would not have time for their star formation to be quenched by the cluster environment (A2029), while an accretion event in the past few Gyr would give galaxies enough time to have their star formation suppressed by the cluster environment. Since these two main quenching mechanisms depend on the density of the intracluster gas, we turn to a group of X-ray underluminous clusters to study how star-forming galaxies have been affected in clusters with lower than expected X-ray emission. We find the distribution of star-forming galaxies with respect to stellar mass varies from cluster to cluster, echoing what we found for Coma and A2029. In other words, while some preprocessing occurs in groups, the cluster environment still contributes to the quenching of star formation.

X ray archeology in the Coma cluster

NASA Technical Reports Server (NTRS)

White, Simon D. M.; Briel, Ulrich G.; Henry, J. Patrick

1993-01-01

Images of X-ray emission from hot gas within the Coma cluster of galaxies are presented. These maps, made with the Rosat satellite, have high signal to noise ratio and allow cluster structure to be analyzed in unprecedented detail. They show greater structural irregularity than could be anticipated from earlier observations of Coma. Emission is detected from a number of bright cluster galaxies in addition to the two known previously. In four cases there is evidence that these galaxies lie at the center of an extended subconcentration within the cluster, possibly the remnant of their associated groups. For at least two galaxies the images show direct evidence for ongoing disruption of their gaseous atmosphere. The luminosity associated with these galaxies is comparable to that detected around similar ellipticals in much poorer environments. Emission is easily detected and appears to become more regular at large radii. The data show that this archetype of a rich and regular galaxy cluster was formed by the merging of several distinct subunits which are not yet fully destroyed.

Analysis of LAC Observations of Clusters of Galaxies and Supernova Remnants

NASA Technical Reports Server (NTRS)

Hughes, J.

1996-01-01

The following publications are included and serve as the final report: The X-ray Spectrum of Abell 665; Clusters of Galaxies; Ginga Observation of an Oxygen-rich Supernova Remnant; Ginga Observations of the Coma Cluster and Studies of the Spatial Distribution of Iron; A Measurement of the Hubble Constant from the X-ray Properties and the Sunyaev-Zel'dovich Effect of Abell 2218; Non-polytropic Model for the Coma Cluster; and Abundance Gradients in Cooling Flow Clusters: Ginga LAC (Large Area Counter) and Einstein SSS (Solid State Spectrometer) Spectra of A496, A1795, A2142, and A2199.

Nonpolytropic model for the Coma Cluster

NASA Technical Reports Server (NTRS)

Fusco-Femiano, R.; Hughes, John P.

1994-01-01

In this article we demonstrate, for the first time, how a physically motivated static model for both the gas and galaxies in the Coma Cluster of galaxies can jointly fit all available X-ray and optical imaging and spectroscopic data. The principal assumption of this nonpolytropic model (Cavaliere & Fusco-Femiano 1981, hereafter CFF), is that the intracluster gas temperature is proportional to the square of the galaxy velocity dispersion everywhere throughout the cluster; no other assumption about the gas temperature distribution is required. After demonstrating that the CFF nonpolytropic model is an adequate representation of the gas and galaxy distributions, the radial velocity dispersion profile, and the gas temperature distribution, we derive the following information about the Coma Cluster: 1. The central temperature is about 9 keV and the central density is 2.8 x 10(exp -3)/cm(exp 3) for the X-ray emitting plasma; 2. The binding mass of the cluster is approximately 2 x 10(exp 15) solar mass within 5 Mpc for (H(sub 0) = 50 km/sec/Mpc), with a mass-to-light ratio of approximately 160 solar mass/solar luminosity; 3. The contribution of the gas to the total virial mass increases with distance from the cluster center, and we estimate that this ratio is no greater than approximately 50% within 5 Mpc. The ability of the CFF nonpolytropic model to describe the current X-ray and optical data for the Coma Cluster suggests that a significant fraction of the thermal energy contained in the hot gas in this as well as other rich galaxy clusters may have come from the interaction between the galaxies and the ambient cluster medium. interaction between the galaxies and the ambient cluster medium.

Evidence of Absence of Tidal Features in the Outskirts of Ultra Diffuse Galaxies in the Coma Cluster

NASA Astrophysics Data System (ADS)

Mowla, Lamiya; van Dokkum, Pieter; Merritt, Allison; Abraham, Roberto; Yagi, Masafumi; Koda, Jin

2017-12-01

We study the presence of tidal features associated with ultra diffuse galaxies (UDGs) in galaxy clusters. Specifically, we stack deep Subaru images of UDGs in the Coma cluster to determine whether they show position angle twists at large radii. Selecting galaxies with central surface brightness μ (g,0)> 24 magarcsec-2 and projected half-light radius {r}e> 1.5 {kpc}, we identify 287 UDGs in the Yagi et al. catalog of low surface brightness Coma objects. The UDGs have apparent spheroidal shapes with median Sérsic index < n> =0.8 and median axis ratio < b/a> =0.7. The images are processed by masking all background objects and rotating to align the major axis before stacking them in bins of properties such as axis ratio, angle of major axis with respect to the cluster center, and separation from cluster center. Our image stacks reach further than 7 kpc (≳4r e). Analysis of the isophotes of the stacks reveals that the ellipticity remains constant up to the last measured point, which means that the individual galaxies have a non-varying position angle and axis ratio and show no evidence for tidal disruption out to ˜ 4{r}e. We demonstrate this explicitly by comparing our stacks with stacks of model UDGs with and without tidal features in their outskirts. We infer that the average tidal radius of the Coma UDGs is >7 kpc and estimate that the average dark matter fraction within the tidal radius of the UDGs inhabiting the innermost 0.5 Mpc of Coma is >99%.

X-ray archaeology in the Coma cluster

NASA Technical Reports Server (NTRS)

White, Simon D. M.; Briel, Ulrich G.; Henry, J. P.

1993-01-01

We present images of X-ray emission from hot gas within the Coma cluster of galaxies. These maps, made with the ROSAT satellite, have much higher SNR than any previous X-ray image of a galaxy cluster, and allow cluster structure to be analyzed in unprecedented detail. They show greater structural irregularity than might have been anticipated from earlier observations of Coma. Emission is detected from a number of bright cluster galaxies in addition to the two known previously. In four cases, there is evidence that these galaxies lie at the center of an extended subconcentration within the cluster, possibly the remnant of their associated groups. For at least two galaxies, the images show direct evidence for ongoing disruption of their gaseous atmosphere. The luminosity associated with these galaxies is comparable to that detected around similar ellipticals in much poorer environments. Emission is easily detected to the limit of our field, about 1 deg from the cluster center, and appears to become more regular at large radii. The data show clearly that this archetype of a rich and regular galaxy cluster was, in fact, formed by the merging of several distinct subunits which are not yet fully destroyed.

The Distance to the Coma Cluster from the Tully--Fisher Relation

NASA Astrophysics Data System (ADS)

Herter, T.; Vogt, N. P.; Haynes, M. P.; Giovanelli, R.

1993-12-01

As part of a survey to determine the distances to nearby (z < .04) Abell clusters via application of the Tully--Fisher (TF) relation, we have obtained 21 cm HI line widths, optical rotation curves and photometric I--band CCD images of galaxies within and near the Coma cluster. Because spiral galaxies within the cluster itself are HI deficient and thus are detected marginally or not at all in HI, distance determinations using only the radio TF relation exclude true cluster members. Our sample includes eight HI deficient galaxies within 1.5 degrees of the cluster center, for which optical velocity widths are derived from their Hα and [NII] rotation curves. The 21 cm line widths have been extracted using a new algorithm designed to optimize the measurement for TF applications, taking into account the effects of spectral resolution and smoothing. The optical width is constructed from the velocity histogram, and is therefore a global value akin to the HI width. A correction for turbulent broadening of the HI is derived from comparison of the optical and HI widths. Using a combined sample of 260 galaxies in 11 clusters and an additional 30 field objects at comparable distances, we have performed a calibration of the radio and optical analogs of the TF relation. Preliminary results show a clear linear relationship with a small offset between optical and radio widths, and good agreement in deriving Tully--Fisher distances to clusters. Our Coma sample consists of 28 galaxies with optical widths and 42 with HI line widths, with an overlapping set of 20 galaxies. We will present the data on the Coma cluster, and discuss the results of our analysis.

The optical properties of galaxies in the Ophiuchus cluster

NASA Astrophysics Data System (ADS)

Durret, F.; Wakamatsu, K.; Adami, C.; Nagayama, T.; Omega Muleka Mwewa Mwaba, J. M.

2018-05-01

Context. Ophiuchus is one of the most massive clusters known, but due to its low Galactic latitude its optical properties remain poorly known. Aims: We investigate the optical properties of Ophiuchus to obtain clues on the formation epoch of this cluster, and compare them to those of the Coma cluster, which is comparable in mass to Ophiuchus but much more dynamically disturbed. Methods: Based on a deep image of the Ophiuchus cluster in the r' band obtained at the Canada France Hawaii Telescope with the MegaCam camera, we have applied an iterative process to subtract the contribution of the numerous stars that, due to the low Galactic latitude of the cluster, pollute the image, and have obtained a photometric catalogue of 2818 galaxies fully complete at r' = 20.5 mag and still 91% complete at r' = 21.5 mag. We use this catalogue to derive the cluster Galaxy Luminosity Function (GLF) for the overall image and for a region (hereafter the "rectangle" region) covering exactly the same physical size as the region in which the GLF of the Coma cluster was previously studied. We then compute density maps based on an adaptive kernel technique, for different magnitude limits, and define three circular regions covering 0.08, 0.08, and 0.06 deg2, respectively, centred on the cluster (C), on northwest (NW) of the cluster, and southeast (SE) of the cluster, in which we compute the GLFs. Results: The GLF fits are much better when a Gaussian is added to the usual Schechter function, to account for the excess of very bright galaxies. Compared to Coma, Ophiuchus shows a strong excess of bright galaxies. Conclusions: The properties of the two nearby very massive clusters Ophiuchus and Coma are quite comparable, though they seem embedded in different large-scale environments. Our interpretation is that Ophiuchus was built up long ago, as confirmed by its relaxed state (see paper I) while Coma is still in the process of forming. The photometric catalogue of Ophiuchus (full Table B.1) is only 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/613/A20

The near-infrared Tully-Fisher relation - A preliminary study of the Coma and Abell 400 clusters

NASA Technical Reports Server (NTRS)

Guhathakurta, Puragra; Bernstein, Gary; Raychaudhury, Somak; Haynes, Martha; Giovanelli, Riccardo; Herter, Terry; Vogt, Nicole

1993-01-01

We have started a large project to study the NIR Tully-Fisher (TF) relation using H- and I-band surface photometry of spiral galaxies. A preliminary study of 20 spirals in the Coma and Abell 400 clusters is presented. The NIR images have been used to derive accurate inclinations and total magnitudes, and rotational linewidths are measured from high-quality 21-cm Arecibo data. The scatter in the Coma TF plot is found to be 0.19 mag in the H band and 0.20 mag in the I band for a set of 13 galaxies, if we assume that they are all at the same distance. The deviation of the Coma galaxies from the best-fit Tully-Fisher relation is correlated with their redshift, indicating that some of the galaxies are not bound to the cluster. Indeed, if we treat all the galaxies in the Coma sample as undergoing free Hubble expansion, the TF scatter drops to 0.12 and 0.13 mag for the H- and I-band datasets, respectively. The Abell 400 sample is best fit by a common distance model, yielding a scatter of 0.12 mag for seven galaxies in H using a fixed TF slope. We are in the process of studying cluster and field spirals out to about 10,000 km/s in order to calibrate the NIR TF relation and will apply it to more nearby galaxies to measure the peculiar velocity field in the local universe.

Preliminary Evidence for a Virial Shock around the Coma Galaxy Cluster

NASA Astrophysics Data System (ADS)

Keshet, Uri; Kushnir, Doron; Loeb, Abraham; Waxman, Eli

2017-08-01

Galaxy clusters, the largest gravitationally bound objects in the universe, are thought to grow by accreting mass from their surroundings through large-scale virial shocks. Due to electron acceleration in such a shock, it should appear as a γ-ray, hard X-ray, and radio ring, elongated toward the large-scale filaments feeding the cluster, coincident with a cutoff in the thermal Sunyaev-Zel’dovich (SZ) signal. However, no such signature was found until now, and the very existence of cluster virial shocks has remained a theory. We find preliminary evidence for a large γ-ray ring of ˜ 5 {Mpc} minor axis around the Coma cluster, elongated toward the large-scale filament connecting Coma and Abell 1367, detected at the nominal 2.7σ confidence level (5.1σ using control signal simulations). The γ-ray ring correlates both with a synchrotron signal and with the SZ cutoff, but not with Galactic tracers. The γ-ray and radio signatures agree with analytic and numerical predictions if the shock deposits ˜ 1 % of the thermal energy in relativistic electrons over a Hubble time and ˜ 1 % in magnetic fields. The implied inverse Compton and synchrotron cumulative emission from similar shocks can contribute significantly to the diffuse extragalactic γ-ray and low-frequency radio backgrounds. Our results, if confirmed, reveal the prolate structure of the hot gas in Coma, the feeding pattern of the cluster, and properties of the surrounding large-scale voids and filaments. The anticipated detection of such shocks around other clusters would provide a powerful new cosmological probe.

The globular cluster systems of 54 Coma ultra-diffuse galaxies: statistical constraints from HST data

NASA Astrophysics Data System (ADS)

Amorisco, N. C.; Monachesi, A.; Agnello, A.; White, S. D. M.

2018-04-01

We use data from the HST Coma Cluster Treasury program to assess the richness of the globular cluster systems (GCSs) of 54 Coma ultra-diffuse galaxies (UDGs), 18 of which have a half-light radius exceeding 1.5 kpc. We use a hierarchical Bayesian method tested on a large number of mock data sets to account consistently for the high and spatially varying background counts in Coma. These include both background galaxies and intra-cluster globular clusters (ICGCs), which are disentangled from the population of member globular clusters (GCs) in a probabilistic fashion. We find no candidate for a GCS as rich as that of the Milky Way, our sample has GCSs typical of dwarf galaxies. For the standard relation between GCS richness and halo mass, 33 galaxies have a virial mass Mvir ≤ 1011 M⊙ at 90 per cent probability. Only three have Mvir > 1011 M⊙ with the same confidence. The mean colour and spread in colour of the UDG GCs are indistinguishable from those of the abundant population of ICGCs. The majority of UDGs in our sample are consistent with the relation between stellar mass and GC richness of `normal' dwarf galaxies. Nine systems, however, display GCSs that are richer by a factor of 3 or more (at 90 per cent probability). Six of these have sizes ≲1.4 kpc. Our results imply that the physical mechanisms responsible for the extended size of the UDGs and for the enhanced GC richness of some cluster dwarfs are at most weakly correlated.

Semiempirical limits on the thermal conductivity of intracluster gas

NASA Technical Reports Server (NTRS)

David, Laurence P.; Hughes, John P.; Tucker, Wallace H.

1992-01-01

A semiempirical method for establishing lower limits on the thermal conductivity of hot gas in clusters of galaxies is described. The method is based on the observation that the X-ray imaging data (e.g., Einstein IPC) for clusters are well described by the hydrostatic-isothermal beta model, even for cooling flow clusters beyond about one core radius. In addition, there are strong indications that noncooling flow clusters (like the Coma Cluster) have a large central region (up to several core radii) of nearly constant gas temperature. This suggests that thermal conduction is an effective means of transporting and redistributing the thermal energy of the gas. This in turn has implications for the extent to which magnetic fields in the cluster are effective in reducing the thermal conductivity of the gas. Time-dependent hydrodynamic simulations for the gas in the Coma Cluster under two separate evolutionary scenarios are presented. One scenario assumes that the cluster potential is static and that the gas has an initial adiabatic distribution. The second scenario uses an evolving cluster potential. These models along with analytic results show that the thermal conductivity of the gas in the Coma Cluster cannot be less than 0.1 of full Spitzer conductivity. These models also show that high gas conductivity assists rather than hinders the development of radiative cooling in the central regions of clusters.

Isothermality of the gas in the Coma cluster

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

Hughes, J.P.; Yamashita, K.; Okumura, Y.

1988-04-01

The high-quality X-ray spectrum of the Coma cluster observed by the Japanese satelite Tenma in conjunction with imaging data from the Einstein Observatory was used to explore the temperature distribution of the cluster gas. It is found that pure polytropic models are inadequate to describe this temperature distribution. Instead, a hybrid model is proposed consisting of a central isothermal region surrounded by a polytropic distribution. It is shown that as much as 75 percent of the global emission may come from the isothermal component. 30 references.

Surveying the Local Supercluster Plane

NASA Astrophysics Data System (ADS)

Kashibadze, O. G.; Karachentsev, I. D.; Karachentseva, V. E.

2018-04-01

We investigate the distribution and velocity field of galaxies situated in a band of 100 by 20 degrees centered on M87 and oriented along the Local supercluster plane. Our sample amounts 2158 galaxies with radial velocities less than 2000 km s-1. Of them, 1119 galaxies (52%) have distance and peculiar velocity estimates. About 3/4 of early-type galaxies are concentrated within the Virgo cluster core, most of the late-type galaxies in the band locate outside the virial radius. Distribution of gas-rich dwarfs with M HI > M * looks to be insensitive to the Virgo cluster presence. Among 50 galaxy groups in the equatorial supercluster band 6 groups have peculiar velocities about 500-1000 km s-1 comparable with virial motions in rich clusters. The most cryptic case is a flock of nearly 30 galaxies around NGC4278 (Coma I cloud), moving to us with the mean peculiar velocity of -840 km s-1. This cloud (or filament?) resides at a distance of 16.1 Mpc from us and approximately 5 Mpc away from the Virgo center. Galaxies around Virgo cluster exhibit Virgocentric infall with an amplitude of about 500 km s-1. Assuming the spherically symmetric radial infall, we estimate the radius of the zero-velocity surface to be R 0 = (7.0±0.3) Mpc that yields the total mass of Virgo cluster to be (7.4 ± 0.9)× 1014M⊙ in tight agreement with its virial mass estimates. We conclude that the Virgo outskirts does not contain significant amounts of dark mater beyond its virial core.

Dwarfs in Coma Cluster

NASA Technical Reports Server (NTRS)

2007-01-01

[figure removed for brevity, see original site] Click on image for larger poster version

This false-color mosaic of the central region of the Coma cluster combines infrared and visible-light images to reveal thousands of faint objects (green). Follow-up observations showed that many of these objects, which appear here as faint green smudges, are dwarf galaxies belonging to the cluster. Two large elliptical galaxies, NGC 4889 and NGC 4874, dominate the cluster's center. The mosaic combines visible-light data from the Sloan Digital Sky Survey (color coded blue) with long- and short-wavelength infrared views (red and green, respectively) from NASA's Spitzer Space Telescope.

Ultraviolet and optical view of galaxies in the Coma Supercluster

NASA Astrophysics Data System (ADS)

Mahajan, Smriti; Singh, Ankit; Shobhana, Devika

2018-05-01

The Coma supercluster (100h-1Mpc) offers an unprecedented contiguous range of environments in the nearby Universe. In this paper we present a catalogue of spectroscopically confirmed galaxies in the Coma supercluster detected in the ultraviolet (UV) wavebands. We use the arsenal of UV and optical data for galaxies in the Coma supercluster covering ˜500 square degrees on the sky to study their photometric and spectroscopic properties as a function of environment at various scales. We identify the different components of the cosmic-web: large-scale filaments and voids using Discrete Persistent Structures Extractor, and groups and clusters using Hierarchical Density-based spatial clustering of applications with noise, respectively. We find that in the Coma supercluster the median emission in Hα inclines, while the g - r and FUV - NUV colours of galaxies become bluer moving further away from the spine of the filaments out to a radius of ˜1 Mpc. On the other hand, an opposite trend is observed as the distance between the galaxy and centre of the nearest cluster or group decreases. Our analysis supports the hypothesis that properties of galaxies are not just defined by its stellar mass and large-scale density, but also by the environmental processes resulting due to the intrafilament medium whose role in accelerating galaxy transformations needs to be investigated thoroughly using multi-wavelength data.

UV SEDs of early-type cluster galaxies: a new look at the UV upturn

NASA Astrophysics Data System (ADS)

Ali, S. S.; Bremer, M. N.; Phillipps, S.; De Propris, R.

2018-05-01

Using GALEX, Ultraviolet Optical Telescope (UVOT), and optical photometry, we explore the prevalence and strength of the Ultraviolet (UV) upturn in the spectra of quiescent early-type galaxies in several nearby clusters. Even for galaxies with completely passive optical colours, there is a large spread in vacuum UV colour consistent with almost all having some UV upturn component. Combining GALEX and UVOT data below 3000 Å, we generate for the first time comparatively detailed UV spectral energy distributions for Coma cluster galaxies. Fitting the UV upturn component with a blackbody, 26 of these show a range of characteristic temperatures (10 000-21 000K) for the UV upturn population. Assuming a single temperature to explain GALEX-optical colours could underestimate the fraction of galaxies with UV upturns and mis-classify some as systems with residual star formation. The UV upturn phenomenon is not an exclusive feature found only in giant galaxies; we identify galaxies with similar (or even bluer) FUV - V colours to the giants with upturns over a range of fainter luminosities. The temperature and strength of the UV upturn are correlated with galaxy mass. Under the plausible hypothesis that the sources of the UV upturn are blue horizontal branch stars, the most likely mechanism for this is the presence of a substantial (between 4 per cent and 20 per cent) Helium-rich (Y > 0.3) population of stars in these galaxies, potentially formed at z ˜ 4 and certainly at z > 2; this plausibly sets a lower limit of {˜ } {0.3- 0.8} × 10^{10} M⊙ to the in situ stellar mass of ˜L* galaxies at this redshift.

Keck/LRIS Spectroscopy of the Distant Cluster Cl0016+16

NASA Astrophysics Data System (ADS)

Wirth, Gregory D.; Koo, David C.

1994-12-01

The rich galaxy cluster Cl0016+16 at z=0.55 initially achieved visibility (Koo 1981) for being the original ``anti Butcher-Oemler effect'' cluster: its galaxy population was found to be almost entirely red, indistinguishable in rest-frame color from local E/S0 galaxies, despite the expectation that higher redshift clusters should have a greater proportion of blue galaxies (Butcher & Oemler 1978, 1984). Interest in this cluster has heightened over the last decade as: X-ray observations found it to be among the most luminous clusters known (Henry et al. 1992); radio observations showed it to be among only a handful of clusters exhibiting a Sunyaev-Zel'dovich microwave decrement, useful for measuring the Hubble Constant (Lasenby 1992); optical spectroscopy revealed a significant population of ``E+A'' galaxies, enigmatic objects with spectra suggesting a recently-concluded episode of star formation (Dressler & Gunn 1992). Further observations by ROSAT, ASCA, and HST have established Cl0016+16 as among the best-studied clusters beyond Coma. The red nature of its galaxy population makes Cl0016+16 a prime candidate for the study of cluster galaxy evolution. As part of an ongoing effort to study the early-type galaxies in this cluster, we recently used the Keck Telescope and Low-Resolution Imaging Spectrograph to obtain high quality spectra of 19 cluster members at 6 Angstroms (FWHM) resolution. This poster describes the preliminary results from these data, which will allow us to investigate galaxy age and metallicity at lookback times nearly halfway to the Big Bang, probe the internal kinematics of galaxies at z=0.55, and thus perhaps trace the evolution of the ``fundamental plane'' for E/S0 galaxies.

A Cluster Of Activities On Coma From The Hubble Space Telescope, StarDate, And McDonald Observatory

NASA Astrophysics Data System (ADS)

Hemenway, Mary Kay; Jogee, S.; Fricke, K.; Preston, S.

2011-01-01

With a goal of providing a vast audience of students, teachers, the general public, and Spanish-speakers with activities to learn about research on the Coma cluster of galaxies based on the HST ACS Treasury survey of Coma, McDonald Observatory used a many-faceted approach. Since this research offered an unprecedented legacy dataset, part of the challenge was to convey the importance of this project to a diverse audience. The methodology was to create different products for different (overlapping) audiences. Five radio programs were produced in English and Spanish for distribution on over 500 radio stations in the US and Mexico with a listening audience of over 2 million; in addition to the radio listeners, there were over 13,000 downloads of the English scripts and almost 6000 of the Spanish. Images were prepared for use in the StarDate Online Astronomy Picture of the Week, for ViewSpace (used in museums), and for the StarDate/Universo Teacher Guide. A high-school level activity on the Coma Cluster was prepared and distributed both on-line and in an upgraded printed version of the StarDate/Universo Teacher Guide. This guide has been distributed to over 1700 teachers nationally. A YouTube video about careers and research in astronomy using the Coma cluster as an example was produced. Just as the activities were varied, so were the evaluation methods. This material is based upon work supported by the National Aeronautics and Space Administration under Grant/Contract/Agreement No. HST-EO-10861.35-A issued through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Thermodynamics of the Coma Cluster Outskirts

NASA Astrophysics Data System (ADS)

Simionescu, A.; Werner, N.; Urban, O.; Allen, S. W.; Fabian, A. C.; Mantz, A.; Matsushita, K.; Nulsen, P. E. J.; Sanders, J. S.; Sasaki, T.; Sato, T.; Takei, Y.; Walker, S. A.

2013-09-01

We present results from a large mosaic of Suzaku observations of the Coma Cluster, the nearest and X-ray brightest hot (~8 keV), dynamically active, non-cool core system, focusing on the thermodynamic properties of the intracluster medium on large scales. For azimuths not aligned with an infalling subcluster toward the southwest, our measured temperature and X-ray brightness profiles exhibit broadly consistent radial trends, with the temperature decreasing from about 8.5 keV at the cluster center to about 2 keV at a radius of 2 Mpc, which is the edge of our detection limit. The southwest merger significantly boosts the surface brightness, allowing us to detect X-ray emission out to ~2.2 Mpc along this direction. Apart from the southwestern infalling subcluster, the surface brightness profiles show multiple edges around radii of 30-40 arcmin. The azimuthally averaged temperature profile, as well as the deprojected density and pressure profiles, all show a sharp drop consistent with an outwardly-propagating shock front located at 40 arcmin, corresponding to the outermost edge of the giant radio halo observed at 352 MHz with the Westerbork Synthesis Radio Telescope. The shock front may be powering this radio emission. A clear entropy excess inside of r 500 reflects the violent merging events linked with these morphological features. Beyond r 500, the entropy profiles of the Coma Cluster along the relatively relaxed directions are consistent with the power-law behavior expected from simple models of gravitational large-scale structure formation. The pressure is also in agreement at these radii with the expected values measured from Sunyaev-Zel'dovich data from the Planck satellite. However, due to the large uncertainties associated with the Coma Cluster measurements, we cannot yet exclude an entropy flattening in this system consistent with that seen in more relaxed cool core clusters.

Membership determination of open clusters based on a spectral clustering method

NASA Astrophysics Data System (ADS)

Gao, Xin-Hua

2018-06-01

We present a spectral clustering (SC) method aimed at segregating reliable members of open clusters in multi-dimensional space. The SC method is a non-parametric clustering technique that performs cluster division using eigenvectors of the similarity matrix; no prior knowledge of the clusters is required. This method is more flexible in dealing with multi-dimensional data compared to other methods of membership determination. We use this method to segregate the cluster members of five open clusters (Hyades, Coma Ber, Pleiades, Praesepe, and NGC 188) in five-dimensional space; fairly clean cluster members are obtained. We find that the SC method can capture a small number of cluster members (weak signal) from a large number of field stars (heavy noise). Based on these cluster members, we compute the mean proper motions and distances for the Hyades, Coma Ber, Pleiades, and Praesepe clusters, and our results are in general quite consistent with the results derived by other authors. The test results indicate that the SC method is highly suitable for segregating cluster members of open clusters based on high-precision multi-dimensional astrometric data such as Gaia data.

Photometric redshifts as a tool for studying the Coma cluster galaxy populations

NASA Astrophysics Data System (ADS)

Adami, C.; Ilbert, O.; Pelló, R.; Cuillandre, J. C.; Durret, F.; Mazure, A.; Picat, J. P.; Ulmer, M. P.

2008-12-01

Aims: We apply photometric redshift techniques to an investigation of the Coma cluster galaxy luminosity function (GLF) at faint magnitudes, in particular in the u* band where basically no studies are presently available at these magnitudes. Methods: Cluster members were selected based on probability distribution function from photometric redshift calculations applied to deep u^*, B, V, R, I images covering a region of almost 1 deg2 (completeness limit R ~ 24). In the area covered only by the u* image, the GLF was also derived after a statistical background subtraction. Results: Global and local GLFs in the B, V, R, and I bands obtained with photometric redshift selection are consistent with our previous results based on a statistical background subtraction. The GLF in the u* band shows an increase in the faint end slope towards the outer regions of the cluster. The analysis of the multicolor type spatial distribution reveals that late type galaxies are distributed in clumps in the cluster outskirts, where X-ray substructures are also detected and where the GLF in the u* band is steeper. Conclusions: We can reproduce the GLFs computed with classical statistical subtraction methods by applying a photometric redshift technique. The u* GLF slope is steeper in the cluster outskirts, varying from α ~ -1 in the cluster center to α ~ -2 in the cluster periphery. The concentrations of faint late type galaxies in the cluster outskirts could explain these very steep slopes, assuming a short burst of star formation in these galaxies when entering the cluster. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is also partly based on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Also based on data from W. M. Keck Observatory which is operated as a scientific partnership between the California Institute of Technology, the University of California, and NASA. It was made possible by the generous financial support of the W. M. Keck Foundation.

New red jewels in Coma Berenices

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

Terrien, Ryan C.; Mahadevan, Suvrath; Deshpande, Rohit

2014-02-20

We have used Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) radial velocity observations in the near-infrared H-band to explore the membership of the nearby (86.7 ± 0.9 pc) open cluster Coma Berenices (Melotte 111), concentrating on the poorly populated low-mass end of the main sequence. Using SDSS-III APOGEE radial velocity measurements, we confirm the membership of eight K/M dwarf members, providing the first confirmed low-mass members of the Coma Berenices cluster. Using R ∼ 2000 spectra from IRTF-SpeX, we confirm the independently luminosity classes of these targets, and find their metallicities to be consistent withmore » the known solar mean metallicity of Coma Berenices and of M dwarfs in the solar neighborhood. In addition, the APOGEE spectra have enabled measurement of vsin i for each target and detection for the first time of the low-mass secondary components of the known binary systems Melotte 111 102 and Melotte 111 120, as well as identification of the previously unknown binary system 2MASS J12214070+2707510. Finally, we use Kilodegree Extremely Little Telescope photometry to measure photometric variability and rotation periods for a subset of the Coma Berenices members.« less

Studies of cluster X-ray sources, energy spectra for the Perseus, Virgo, and Coma clusters

NASA Technical Reports Server (NTRS)

Kellogg, E.; Baldwin, J. R.; Koch, D.

1975-01-01

Final Uhuru X-ray differential-energy spectra are presented for the Perseus, Virgo, and Coma clusters. Power-law and isothermal bremsstrahlung model spectra with low-energy cutoffs are given, and the energy-dependent Gaunt factor is calculated for the bremsstrahlung. The spectra, which are best fits to the Uhuru data between 2 and 10 keV, are compared with previous observations of these sources in the energy range from 0.1 to 100 keV. The problem of parameter estimation is discussed, error bars with 68% confidence are given for the independently determined slope and cutoff parameters, and the 68% confidence limits are plotted for the fitted spectral functions. The data for Perseus above 20 keV marginally favor the bremsstrahlung fit, those for Virgo between 0.25 and 1.0 keV clearly favor that curve, and those for Coma indicate a low-energy turnover or cutoff. Implications of such a cutoff are briefly discussed.

SUZAKU OBSERVATIONS OF SUBHALOS IN THE COMA CLUSTER

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

Sasaki, Toru; Matsushita, Kyoko; Sato, Kosuke

2015-06-10

We observed three massive subhalos in the Coma cluster with Suzaku. These subhalos, labeled “ID 1,” “ID 2,” and “ID 32,” were detected with a weak-lensing survey using Subaru/Suprime-Cam, and are located at the projected distances of 1.4 r{sub 500}, 1.2 r{sub 500}, and 1.6 r{sub 500} from the center of the Coma cluster, respectively. The subhalo “ID 1” has a compact X-ray excess emission close to the center of the weak-lensing mass contour, and the gas mass to weak-lensing mass ratio is about 0.001. The temperature of the emission is about 3 keV, which is slightly lower than thatmore » of the surrounding intracluster medium (ICM) and that expected for the temperature versus mass relation of clusters of galaxies. The subhalo “ID 32” shows an excess emission whose peak is shifted toward the opposite direction from the center of the Coma cluster. The gas mass to weak-lensing mass ratio is also about 0.001, which is significantly smaller than regular galaxy groups. The temperature of the excess is about 0.5 keV and significantly lower than that of the surrounding ICM and far from the temperature versus mass relation of clusters. However, there is no significant excess X-ray emission in the “ID 2” subhalo. Assuming an infall velocity of about 2000 km s{sup −1}, at the border of the excess X-ray emission, the ram pressures for “ID 1” and “ID 32” are comparable to the gravitational restoring force per area. We also studied the effect of the Kelvin–Helmholtz instability to strip the gas. Although we found X-ray clumps associated with the weak-lensing subhalos, their X-ray luminosities are much lower than the total ICM luminosity in the cluster outskirts.« less

DRY MERGER RATE AND POST-MERGER FRACTION IN THE COMA CLUSTER CORE

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

Cordero, Juan P.; Campusano, Luis E.; Haines, Christopher P.

2016-01-20

We evaluate the dry merger activity in the Coma cluster, using a spectroscopically complete sample of 70 red-sequence (RS) galaxies, most of which (∼75%) are located within 0.2R{sub 200} (∼0.5 Mpc) from the cluster center, with data from the Coma Treasury Survey obtained with the Hubble Space Telescope. The fraction of close galaxy pairs in the sample is the proxy employed for the estimation of the merger activity. We identify 5 pairs and 1 triplet, enclosing a total of 13 galaxies, based on limits on projected separation and line-of-sight velocity difference. Of these systems, none show signs of ongoing interaction,more » and therefore we do not find any true mergers in our sample. This negative result sets a 1σ upper limit of 1.5% per Gyr for the major dry merger rate, consistent with the low rates expected in present-day clusters. Detailed examination of the images of all the RS galaxies in the sample reveals only one with low surface brightness features identifiable as the remnant of a past merger or interaction, implying a post-merger fraction below 2%.« less

THERMODYNAMICS OF THE COMA CLUSTER OUTSKIRTS

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

Simionescu, A.; Werner, N.; Urban, O.

2013-09-20

We present results from a large mosaic of Suzaku observations of the Coma Cluster, the nearest and X-ray brightest hot ({approx}8 keV), dynamically active, non-cool core system, focusing on the thermodynamic properties of the intracluster medium on large scales. For azimuths not aligned with an infalling subcluster toward the southwest, our measured temperature and X-ray brightness profiles exhibit broadly consistent radial trends, with the temperature decreasing from about 8.5 keV at the cluster center to about 2 keV at a radius of 2 Mpc, which is the edge of our detection limit. The southwest merger significantly boosts the surface brightness,more » allowing us to detect X-ray emission out to {approx}2.2 Mpc along this direction. Apart from the southwestern infalling subcluster, the surface brightness profiles show multiple edges around radii of 30-40 arcmin. The azimuthally averaged temperature profile, as well as the deprojected density and pressure profiles, all show a sharp drop consistent with an outwardly-propagating shock front located at 40 arcmin, corresponding to the outermost edge of the giant radio halo observed at 352 MHz with the Westerbork Synthesis Radio Telescope. The shock front may be powering this radio emission. A clear entropy excess inside of r{sub 500} reflects the violent merging events linked with these morphological features. Beyond r{sub 500}, the entropy profiles of the Coma Cluster along the relatively relaxed directions are consistent with the power-law behavior expected from simple models of gravitational large-scale structure formation. The pressure is also in agreement at these radii with the expected values measured from Sunyaev-Zel'dovich data from the Planck satellite. However, due to the large uncertainties associated with the Coma Cluster measurements, we cannot yet exclude an entropy flattening in this system consistent with that seen in more relaxed cool core clusters.« less

KECK/LRIS SPECTROSCOPIC CONFIRMATION OF COMA CLUSTER DWARF GALAXY MEMBERSHIP ASSIGNMENTS

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

Chiboucas, Kristin; Tully, R. Brent; Marzke, Ronald O.

2010-11-01

Keck/LRIS multi-object spectroscopy has been carried out on 140 of some of the lowest and highest surface brightness faint (19 < R < 22) dwarf galaxy candidates in the core region of the Coma Cluster. These spectra are used to measure redshifts and establish membership for these faint dwarf populations. The primary goal of the low surface brightness sample is to test our ability to use morphological and surface brightness criteria to distinguish between Coma Cluster members and background galaxies using high resolution Hubble Space Telescope/Advanced Camera for Surveys images. Candidates were rated as expected members, uncertain, or expected background.more » From 93 spectra, 51 dwarf galaxy members and 20 background galaxies are identified. Our morphological membership estimation success rate is {approx}100% for objects expected to be members and better than {approx}90% for galaxies expected to be in the background. We confirm that low surface brightness is a very good indicator of cluster membership. High surface brightness galaxies are almost always background with confusion arising only from the cases of the rare compact elliptical (cE) galaxies. The more problematic cases occur at intermediate surface brightness. Many of these galaxies are given uncertain membership ratings, and these were found to be members about half of the time. Including color information will improve membership determination but will fail for some of the same objects that are already misidentified when using only surface brightness and morphology criteria. cE galaxies with B-V colors {approx}0.2 mag redward of the red sequence in particular require spectroscopic follow up. In a sample of 47 high surface brightness, ultracompact dwarf candidates, 19 objects have redshifts which place them in the Coma Cluster, while another 6 have questionable redshift measurements but may also prove to be members. Redshift measurements are presented and the use of indirect means for establishing cluster membership is discussed.« less

The Perseus Cluster: Bridging the Extremes of Stellar Systems

NASA Astrophysics Data System (ADS)

Harris, William

2017-08-01

The Perseus cluster (Abell 426) at d=75 Mpc is as massive and diverse as Virgo and Coma and displays a rich laboratory for studying galaxy evolution. Its massive X-ray halo gas component and its high proportion of large early-type galaxies point to a long history of dynamical interaction amongst the cluster members. The central supergiant, NGC 1275, is perhaps the most active galaxy in the local universe, with a spectacular network of H-alpha filaments, cooling flows, feedback, and prominent star formation in plain view. We propose to use the Globular Cluster (GC) populations in the Perseus region with two-band imaging to pursue three connected goals: the stellar Intracluster Medium (ICM); its Ultra-Diffuse Galaxies (UDGs); and the GC populations in the Perseus core galaxies. Our analysis of a few HST/ACS Archival images covering the Perseus core strongly indicates that a substantial Intragalactic GC component is present. Our newly discovered sample of UDGs in Perseus covers the entire parameter space of these intriguing galaxies and will be thoroughly sampled in our study: are they 'failed' underluminous galaxies with high masses, or are they a mixed bag? For all our goals, the GC populations will act as powerful tracers of the dominant old stellar populations - their metallicity distributions and total populations in the ICM, the UDGs, and the three largest E galaxies in Perseus. As a bonus, we expect to find 200 new Ultra-Compact Dwarfs (UCDs) and half a dozen rare compact ellipticals (cEs). The scientific payoffs will include a broader understanding of the nature and history of all these types of galaxies and their stripped stellar material.

A Giant Warm Baryonic Halo for the Coma Cluster

NASA Technical Reports Server (NTRS)

Bonamente, Max; Lieu, Richard; Joy, Marshall K.; Six, N. Frank (Technical Monitor)

2002-01-01

Several deep PSPC observations of the Coma cluster unveil a very large-scale halo of soft X-ray emission, substantially in excess of the well know radiation from the hot intra-cluster medium. The excess emission, previously reported in the central cluster regions through lower-sensitivity EUVE and ROSAT data, is now evident out to a radius of 2.5 Mpc, demonstrating that the soft excess radiation from clusters is a phenomenon of cosmological significance. The spectrum at these large radii cannot be modeled non-thermally, but is consistent with the original scenario of thermal emission at warm temperatures. The mass of this plasma is at least on par with that of the hot X-ray emitting plasma, and significantly more massive if the plasma resides in low-density filamentary structures. Thus the data lend vital support to current theories of cosmic evolution, which predict greater than 50 percent by mass of today's baryons reside in warm-hot filaments converging at clusters of galaxies.

Coma cluster ultradiffuse galaxies are not standard radio galaxies

NASA Astrophysics Data System (ADS)

Struble, Mitchell F.

2018-02-01

Matching members in the Coma cluster catalogue of ultradiffuse galaxies (UDGs) from SUBARU imaging with a very deep radio continuum survey source catalogue of the cluster using the Karl G. Jansky Very Large Array (VLA) within a rectangular region of ∼1.19 deg2 centred on the cluster core reveals matches consistent with random. An overlapping set of 470 UDGs and 696 VLA radio sources in this rectangular area finds 33 matches within a separation of 25 arcsec; dividing the sample into bins with separations bounded by 5, 10, 20 and 25 arcsec finds 1, 4, 17 and 11 matches. An analytical model estimate, based on the Poisson probability distribution, of the number of randomly expected matches within these same separation bounds is 1.7, 4.9, 19.4 and 14.2, each, respectively, consistent with the 95 per cent Poisson confidence intervals of the observed values. Dividing the data into five clustercentric annuli of 0.1° and into the four separation bins, finds the same result. This random match of UDGs with VLA sources implies that UDGs are not radio galaxies by the standard definition. Those VLA sources having integrated flux >1 mJy at 1.4 GHz in Miller, Hornschemeier and Mobasher without SDSS galaxy matches are consistent with the known surface density of background radio sources. We briefly explore the possibility that some unresolved VLA sources near UDGs could be young, compact, bright, supernova remnants of Type Ia events, possibly in the intracluster volume.

Variability of higher order wavefront aberrations after blinks.

PubMed

Hagyó, Krisztina; Csákány, Béla; Lang, Zsolt; Németh, János

2009-01-01

To investigate the rapid alterations in value and fluctuation of ocular wavefront aberrations during the interblink interval. Forty-two volunteers were examined with a WASCA Wavefront Analyzer (Carl Zeiss Meditec AG) using modified software. For each subject, 150 images (about 6 frames/second) were registered during an interblink period. The outcome measures were spherical and cylindrical refraction and root-mean-square (RMS) values for spherical, coma, and total higher order aberrations. Fifth order polynomials were fitted to the data and the fluctuation trends of the parameters were determined. We calculated the prevalence of the trends with an early local minimum (type 1). The tear production status (Schirmer test) and tear film break-up time (BUT) were also measured. Fluctuation trends with an early minimum (type 1) were significantly more frequent than trends with an early local maximum (type 2) for total higher order aberrations RMS (P=.036). The incidence of type 1 fluctuation trends was significantly greater for coma and total higher order aberrations RMS (P=.041 and P=.003, respectively) in subjects with normal results in the BUT or Schirmer test than in those with abnormal results. In the normal subjects, the first minimum of type 1 RMS fluctuation trends occurred, on average, between 3.8 and 5.1 seconds after blink. We suggest that wavefront aberrations can be measured most accurately at the time after blink when they exhibit a decreased degree of dispersion. We recommend that a snapshot of wavefront measurements be made 3 to 5 seconds after blink.

Discovery of the Kinematic Alignment of Early-type Galaxies in the Virgo Cluster

NASA Astrophysics Data System (ADS)

Kim, Suk; Jeong, Hyunjin; Lee, Jaehyun; Lee, Youngdae; Joo, Seok-Joo; Kim, Hak-Sub; Rey, Soo-Chang

2018-06-01

Using the kinematic position angles (PAkin), an accurate indicator for the spin axis of a galaxy, obtained from the ATLAS3D integral-field-unit (IFU) spectroscopic data, we discovered that 57 Virgo early-type galaxies tend to prefer the specific PAkin values of 20° and 100°, suggesting that they are kinematically aligned with each other. These kinematic alignment angles are further associated with the directions of the two distinct axes of the Virgo cluster extending east–west and north–south, strongly suggesting that the two distinct axes are the filamentary structures within the cluster as a trace of infall patterns of galaxies. Given that the spin axis of a massive early-type galaxy does not change easily even in clusters from the hydrodynamic simulations, Virgo early-type galaxies are likely to fall into the cluster along the filamentary structures while maintaining their angular momentum. This implies that many early-type galaxies in clusters are formed in filaments via major mergers before subsequently falling into the cluster. Investigating the kinematic alignment in other clusters will allow us to understand the formation of galaxy clusters and early-type galaxies.

PCA/HEXTE Observations of Coma and A2319

NASA Technical Reports Server (NTRS)

Rephaeli, Yoel

1998-01-01

The Coma cluster was observed in 1996 for 90 ks by the PCA and HEXTE instruments aboard the RXTE satellite, the first simultaneous, pointing measurement of Coma in the broad, 2-250 keV, energy band. The high sensitivity achieved during this long observation allows precise determination of the spectrum. Our analysis of the measurements clearly indicates that in addition to the main thermal emission from hot intracluster gas at kT=7.5 keV, a second spectral component is required to best-fit the data. If thermal, it can be described with a temperature of 4.7 keV contributing about 20% of the total flux. The additional spectral component can also be described by a power-law, possibly due to Compton scattering of relativistic electrons by the CMB. This interpretation is based on the diffuse radio synchrotron emission, which has a spectral index of 2.34, within the range allowed by fits to the RXTE spectral data. A Compton origin of the measured nonthermal component would imply that the volume-averaged magnetic field in the central region of Coma is B =0.2 micro-Gauss, a value deduced directly from the radio and X-ray measurements (and thus free of the usual assumption of energy equipartition). Barring the presence of unknown systematic errors in the RXTE source or background measurements, our spectral analysis yields considerable evidence for Compton X-ray emission in the Coma cluster.

Hubble Sees 'Island Universe' in the Coma Cluster

NASA Image and Video Library

2017-12-08

NASA image release August 10, 2010 A long-exposure Hubble Space Telescope image shows a majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies, which lies 320 million light-years away in the northern constellation Coma Berenices. The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes. The high resolution of Hubble's cameras, paired with considerably long exposures, made it possible to observe these faint details. NGC 4911 and other spirals near the center of the cluster are being transformed by the gravitational tug of their neighbors. In the case of NGC 4911, wispy arcs of the galaxy's outer spiral arms are being pulled and distorted by forces from a companion galaxy (NGC 4911A), to the upper right. The resultant stripped material will eventually be dispersed throughout the core of the Coma Cluster, where it will fuel the intergalactic populations of stars and star clusters. The Coma Cluster is home to almost 1,000 galaxies, making it one of the densest collections of galaxies in the nearby universe. It continues to transform galaxies at the present epoch, due to the interactions of close-proximity galaxy systems within the dense cluster. Vigorous star formation is triggered in such collisions. Galaxies in this cluster are so densely packed that they undergo frequent interactions and collisions. When galaxies of nearly equal masses merge, they form elliptical galaxies. Merging is more likely to occur in the center of the cluster where the density of galaxies is higher, giving rise to more elliptical galaxies. This natural-color Hubble image, which combines data obtained in 2006, 2007, and 2009 from the Wide Field Planetary Camera 2 and the Advanced Camera for Surveys, required 28 hours of exposure time. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: K. Cook (Lawrence Livermore National Laboratory) To learn more about Hubble go to: www.nasa.gov/mission_pages/hubble/main/index.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Globular Clusters for Faint Galaxies

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-07-01

The origin of ultra-diffuse galaxies (UDGs) has posed a long-standing mystery for astronomers. New observations of several of these faint giants with the Hubble Space Telescope are now lending support to one theory.Faint-Galaxy MysteryHubble images of Dragonfly 44 (top) and DFX1 (bottom). The right panels show the data with greater contrast and extended objects masked. [van Dokkum et al. 2017]UDGs large, extremely faint spheroidal objects were first discovered in the Virgo galaxy cluster roughly three decades ago. Modern telescope capabilities have resulted in many more discoveries of similar faint galaxies in recent years, suggesting that they are a much more common phenomenon than we originally thought.Despite the many observations, UDGs still pose a number of unanswered questions. Chief among them: what are UDGs? Why are these objects the size of normal galaxies, yet so dim? There are two primary models that explain UDGs:UDGs were originally small galaxies, hence their low luminosity. Tidal interactions then puffed them up to the large size we observe today.UDGs are effectively failed galaxies. They formed the same way as normal galaxies of their large size, but something truncated their star formation early, preventing them from gaining the brightness that we would expect for galaxies of their size.Now a team of scientists led by Pieter van Dokkum (Yale University) has made some intriguing observations with Hubble that lend weight to one of these models.Globulars observed in 16 Coma-cluster UDGs by Hubble. The top right panel shows the galaxy identifications. The top left panel shows the derived number of globular clusters in each galaxy. [van Dokkum et al. 2017]Globulars GaloreVan Dokkum and collaborators imaged two UDGs with Hubble: Dragonfly 44 and DFX1, both located in the Coma galaxy cluster. These faint galaxies are both smooth and elongated, with no obvious irregular features, spiral arms, star-forming regions, or other indications of tidal interactions.The most striking feature of these galaxies, however, is that they are surrounded by a large number of compact objects that appear to be globular clusters. From the observations, Van Dokkum and collaborators estimate that Dragonfly 44 and DFX1 have approximately 74 and 62 globulars, respectively significantly more than the low numbers expected for galaxies of this luminosity.Armed with this knowledge, the authors went back and looked at archival observations of 14 other UDGs also located in the Coma cluster. They found that these smaller and fainter galaxies dont host quite as many globular clusters as Dragonfly 44 and DFX1, but more than half also show significant overdensities of globulars.Main panel: relation between the number of globular clusters and total absolute magnitude for Coma UDGs (solid symbols) compared to normal galaxies (open symbols). Top panel: relation between effective radius and absolute magnitude. The UDGs are significantly larger and have more globular clusters than normal galaxies of the same luminosity. [van Dokkum et al. 2017]Evidence of FailureIn general, UDGs appear to have more globular clusters than other galaxies of the same total luminosity, by a factor of nearly 7. These results are consistent with the scenario in which UDGs are failed galaxies: they likely have the halo mass to have formed a large number of globular clusters, but they were quenched before they formed a disk and bulge. Because star formation never got going in UDGs, they are now much dimmer than other galaxies of the same size.The authors suggest that the next step is to obtain dynamical measurements of the UDGs to determine whether these faint galaxies really do have the halo mass suggested by their large numbers of globulars. Future observations will continue to help us pin down the origin of these dim giants.CitationPieter van Dokkum et al 2017 ApJL 844 L11. doi:10.3847/2041-8213/aa7ca2

1.65 μm (H-band) surface photometry of galaxies. III. observations of 558 galaxies with the TIRGO 1.5 m telescope

NASA Astrophysics Data System (ADS)

Gavazzi, G.; Franzetti, P.; Scodeggio, M.; Boselli, A.; Pierini, D.; Baffa, C.; Lisi, F.; Hunt, L. K.

2000-02-01

We present near-infrared H-band (1.65 μm ) surface photometry of 558 galaxies in the Coma Supercluster and in the Virgo cluster. This data set, obtained with the Arcetri NICMOS3 camera ARNICA mounted on the Gornergrat Infrared Telescope, is aimed at complementing, with observations of mostly early-type objects, our NIR survey of spiral galaxies in these regions, presented in previous papers of this series. Magnitudes at the optical radius, total magnitudes, isophotal radii and light concentration indices are derived. We confirm the existence of a positive correlation between the near-infrared concentration index and the galaxy H-band luminosity Based on observations taken at TIRGO (Gornergrat, Switzerland). TIRGO is operated by CAISMI-CNR, Arcetri, Firenze, Italy. Tables 1 and 2 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Analysis of Risk Factors for Hypoglycemic Coma in 194 Patients with Type 2 Diabetes

PubMed Central

Lu, Zefen; Liu, Jianfeng; He, Qing; Chakraborty, Anindita; Zhu, Tiehong

2017-01-01

Background The present study was conducted to analyze possible risk factors in patients with type 2 diabetes who are in hypoglycemic coma. Material/Methods A total of 194 patients with type 2 diabetic hypoglycemic coma who were admitted to our hospital between January 2010 and January 2016 were included. The patients were all in coma on admission, and their blood glucose levels were lower than 2.8 mmol/L. None of the patients had type I diabetes, specific types of diabetes, or gestational diabetes. Multiple linear regression analysis was used to determine possible factors associated with hypoglycemic coma. Results Among the patients, 82 were male and 112 were female (mean age, 66.88±10.62 years). In addition, 72 patients lived in urban areas and 122 lived in rural areas. Occurrence of hypoglycemic coma was correlated with difference between urban and rural residence, glycosylated hemoglobin (HbA1c) level, combined hypertension, and combined neural complications. Self-purchased drugs resulted in significantly lower blood glucose level at the onset of hypoglycemic coma than insulin, secretagogue, or non-secretagogue drugs. Blood glucose level at onset was correlated with season. Patients living in rural areas or with combined macrovascular or microvascular complications had prolonged hospital stay and poor prognosis. Conclusions Our results demonstrate that rural residence, higher HbA1c level, combined hypertension, and combined neural complications increase the incidence of hypoglycemic coma. Use of self-purchased drugs and colder seasons may result in lower blood glucose levels in patients with hypoglycemic coma. PMID:29180613

Search for Gamma-Ray Emission from the Coma Cluster with Six Years of Fermi-LAT Data

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.;

Search for gamma-ray emission from the Coma Cluster with six years of Fermi-LAT data

DOE PAGES

Ackermann, M.

2016-03-08

We present results from γ-ray observations of the Coma cluster incorporating 6 years of Fermi-LAT data and the newly released “Pass 8” event-level analysis. Our analysis of the region reveals low-significance residual structures within the virial radius of the cluster that are too faint for a detailed investigation with the current data. Using a likelihood approach that is free of assumptions on the spectral shape we derive upper limits on the γ-ray flux that is expected from energetic particle interactions in the cluster. We also consider a benchmark spatial and spectral template motivated by models in which the observed radiomore » halo is mostly emission by secondary electrons. In this case, the median expected and observed upper limits for the flux above 100MeV are 1.7 x 10 -9 ph cm -2 s -1 and 5.2 x 10 -9 ph cm -2 s -1 respectively (the latter corresponds to residual emission at the level of 1:8σ). These bounds are comparable to or higher than predicted levels of hadronic gamma-ray emission in cosmic-ray models with or without reacceleration of secondary electrons, although direct comparisons are sensitive to assumptions regarding the origin and propagation mode of cosmic rays and magnetic field properties. The minimal expected γ-ray flux from radio and star-forming galaxies within the Coma cluster is roughly an order of magnitude below the median sensitivity of our analysis.« less

A Suzaku Search for Nonthermal Emission at Hard X-Ray Energies in the Coma Cluster

DTIC Science & Technology

2008-09-01

monochromatic fluxes FR(νR), FX (νX) at frequencies νR , νX, for a power-law distribution of electrons, from which we can derive an expression for the magnetic...field as B = C(p)(1 + z)(p+5)/(p+1) ( FR FX )2/(p+1) ( νR νX )(p−1)/(p+1) , (14) where p is the index of the electron distribution N (E) ∝ E−p and is...IN THE COMA CLUSTER 1711 like NuStar,10 Astro -H (previously NeXT),11 and Simbol-X.12 If the IC emission is localized, then our joint fitting

Prognosis of patients in coma after acute subdural hematoma due to ruptured intracranial aneurysm.

PubMed

Torné, Ramon; Rodríguez-Hernández, Ana; Romero-Chala, Fabián; Arikan, Fuat; Vilalta, Jordi; Sahuquillo, Juan

2016-04-01

Acute subdural hematomas (aSDH) secondary to intracranial aneurysm rupture are rare. Most patients present with coma and their functional prognosis has been classically considered to be very poor. Previous studies mixed good-grade and poor-grade patients and reported variable outcomes. We reviewed our experience by focusing on patients in coma only and hypothesized that aSDH might worsen initial mortality but not long-term functional outcome. Between 2005 and 2013, 440 subarachnoid hemorrhage (SAH) patients were admitted to our center. Nineteen (4.3%) were found to have an associated aSDH and 13 (2.9%) of these presented with coma. Their prospectively collected clinical and outcome data were reviewed and compared with that of 104 SAH patients without aSDH who presented with coma during the same period. Median aSDH thickness was 10mm. Four patients presented with an associated aneurysmal cortical laceration and only one had good recovery. Overall, we observed good long-term outcomes in both SAH patients in coma with aSDH and those without aSDH (38.5% versus 26.4%). Associated aSDH does not appear to indicate a poorer long-term functional prognosis in SAH patients presenting with coma. Anisocoria and brain herniation are observed in patients with aSDH thicknesses that are smaller than those observed in trauma patients. Despite a high initial mortality, early surgery to remove the aSDH results in a good outcome in over 60% of survivors. Aneurysmal cortical laceration appears to be an independent entity which shows a poorer prognosis than other types of aneurysmal aSDH. Copyright © 2015 Elsevier Ltd. All rights reserved.

ROSAT observations of Coma Cluster galaxies

NASA Technical Reports Server (NTRS)

Dow, K. L.; White, S. D. M.

1995-01-01

The approximately 86 ks ROSAT Position Sensitive Proportional Counter (PSPC) image of the Coma Cluster is deeper than any previous X-ray observation of a galaxy cluster. We search for X-ray emission from 35 individual galaxies in a magnitude-limited sample, all of which lie within 20 arcmins of the optical axis in at least one of the four Coma pointings. We detect seven galaxies in the 0.4-2.4 keV band at a significance level exceeding 3 sigma, and a further four at above 2 sigma. Although we can set only upper limits on the individual flux from each of the other galaxies, we are able to measure their mean flux by stacking the observations. The X-ray luminosities of the seven detections range from 6.2 x 10(exp 40) to 1.5 x 10(exp 42) ergs/s (0.4-2.4 keV for H(sub 0) = 50 km/s/Mpc). For galaxies with a blue absolute magnitude of about -21 we find a mean X-ray luminosity of 1.3 x 10(exp 40) ergs/s. The ratio of X-ray to optical luminosity is substantially smaller for such subjects than for the brightest galaxies in the cluster. The X-ray luminosities of the four brightest galaxies are ill-defined, however, because of ambiguity in distinguishing galaxy emission from cluster emission. Each object appears to be related to significant structure in the diffuse intracluster medium. We also investigate emission in the softer 0.2-0.4 keV band where detections are less significant because of the higher background, and we discuss the properties of a number of interesting individual sources. The X-ray luminosities of the Coma galaxies are similar to those of galaxies in the Virgo Cluster and in other regions with relatively low galaxy density. We conclude that large-scale environmental effects do not significantly enhance or suppress the average X-ray emission from galaxies, but that individual objects vary in luminosity substantially in a way which may depend on the detailed history of their environment.

EEG in connection with coma.

PubMed

Wilson, John A; Nordal, Helge J

2013-01-08

Coma is a dynamic condition that may have various causes. Important changes may take place rapidly, often with consequences for treatment. The purpose of this article is to provide a brief overview of EEG patterns in comas with various causes, and indicate how EEG contributes in an assessment of the prognosis for coma patients. The article is based on many years of clinical and research-based experience of EEG used for patients in coma. A self-built reference database was supplemented by searches for relevant articles in PubMed. EEG reveals immediate changes in coma, and can provide early information on cause and prognosis. It is the only diagnostic tool for detecting a non-convulsive epileptic status. Locked-in- syndrome may be overseen without EEG. Repeated EEG scans increase diagnostic certainty and make it possible to monitor the development of coma. EEG reflects brain function continuously and therefore holds a key place in the assessment and treatment of coma.

Involuntary movements and coma as the prognostic marker for acute encephalopathy with biphasic seizures and late reduced diffusion.

PubMed

Lee, Sooyoung; Sanefuji, Masafumi; Torio, Michiko; Kaku, Noriyuki; Ichimiya, Yuko; Mizuguchi, Soichi; Baba, Haruhisa; Sakai, Yasunari; Ishizaki, Yoshito; Torisu, Hiroyuki; Kira, Ryutaro; Hara, Toshiro; Ohga, Shouichi

2016-11-15

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) occurs in children associated with infection. It is characterized by a prolonged febrile seizure in the first phase, and a cluster of seizures, deterioration of consciousness and the white matter lesions with reduced diffusion in the second phase. The patients often have severe neurological sequelae, but the prognostic indicators remain unknown. The present study aimed to clarify the characteristics of AESD patients who subsequently exhibited severe neurological sequelae. We retrospectively analyzed the clinical and laboratory findings along with the brain imaging in patients who had severe (n=8) and non-severe neurodevelopmental outcomes (n=12). Severe group more frequently showed coma (p=0.014) or involuntary movements including dystonia and oral dyskinesia (p=0.018) before the second phase than non-severe group. Severe group exhibited higher levels of serum alanine aminotransferase than non-severe group (p=0.001). Quantitatively assessed MRI in the second phase revealed that severe group had more extensive lesions than non-severe group, in the anterior (p=0.015) and posterior parts (p=0.011) of the cerebrum and basal ganglia (p=0.020). Early appearing involuntary movements or coma might account for the extension of acute brain lesions and the poor neurological outcomes in AESD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

[The diagnosis and treatment of myxedema coma].

PubMed

Aoki, Chie; Kasai, Kikuo

2012-11-01

Myxedema coma is defined as severe hypothyroidism leading to decreased mental status, hypothermia, and other symptoms related to dysfunction in multiple organs. It is very rare disease with high mortality rate. Early recognition and therapy of myxedema coma are essential, and treatment should be begun on the basis of clinical suspection. However, regimen of myxedema is not well established even now, especially about thyroid hormone supplementation. Japan Thyroid Association is drawing up "The diagnostic criteria of myxedema coma (3rd draft) and preliminary guide to treatment of it". According to this criteria and preliminary guide, the clinical presentation, diagnosis, and treatment of myxedema coma will be reviewed here.

The role of Dark Matter sub-halos in the non-thermal emission of galaxy clusters

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

Marchegiani, Paolo; Colafrancesco, Sergio, E-mail: Paolo.Marchegiani@wits.ac.za, E-mail: Sergio.Colafrancesco@wits.ac.za

2016-11-01

Annihilation of Dark Matter (DM) particles has been recognized as one of the possible mechanisms for the production of non-thermal particles and radiation in galaxy clusters. Previous studies have shown that, while DM models can reproduce the spectral properties of the radio halo in the Coma cluster, they fail in reproducing the shape of the radio halo surface brightness because they produce a shape that is too concentrated towards the center of the cluster with respect to the observed one. However, in previous studies the DM distribution was modeled as a single spherically symmetric halo, while the DM distribution inmore » Coma is found to have a complex and elongated shape. In this work we calculate a range of non-thermal emissions in the Coma cluster by using the observed distribution of DM sub-halos. We find that, by including the observed sub-halos in the DM model, we obtain a radio surface brightness with a shape similar to the observed one, and that the sub-halos boost the radio emission by a factor between 5 and 20%, thus allowing to reduce the gap between the annihilation cross section required to reproduce the radio halo flux and the upper limits derived from other observations, and that this gap can be explained by realistic values of the boosting factor due to smaller substructures. Models with neutralino mass of 9 GeV and composition τ{sup +} τ{sup −}, and mass of 43 GeV and composition b b-bar can fit the radio halo spectrum using the observed properties of the magnetic field in Coma, and do not predict a gamma-ray emission in excess compared to the recent Fermi-LAT upper limits. These findings make these DM models viable candidate to explain the origin of radio halos in galaxy clusters, avoiding the problems connected to the excessive gamma-ray emission expected from proton acceleration in most of the currently proposed models, where the acceleration of particles is directly or indirectly connected to events related to clusters merging. Therefore, DM models deserve to be better studied both from the theoretical and observational sides; the best spectral bands where it is possible to obtain better information are the radio and the gamma-ray bands, while we do not expect a strong emission in the X-ray band.« less

Stellar systems in the direction of the Hickson Compact Group 44. I. Low surface brightness galaxies

NASA Astrophysics Data System (ADS)

Smith Castelli, A. V.; Faifer, F. R.; Escudero, C. G.

2016-11-01

Context. In spite of the numerous studies of low-luminosity galaxies in different environments, there is still no consensus about their formation scenario. In particular, a large number of galaxies displaying extremely low-surface brightnesses have been detected in the last year, and the nature of these objects is under discussion. Aims: In this paper we report the detection of two extended low-surface brightness (LSB) objects (μeffg' ≃ 27 mag) found, in projection, next to NGC 3193 and in the zone of the Hickson Compact Group (HCG) 44, respectively. Methods: We analyzed deep, high-quality, GEMINI-GMOS images with ELLIPSE within IRAF in order to obtain their brightness profiles and structural parameters. We also searched for the presence of globular clusters (GC) in these fields. Results: We have found that, if these LSB galaxies were at the distances of NGC 3193 and HCG 44, they would show sizes and luminosities similar to those of the ultra-diffuse galaxies (UDGs) found in the Coma cluster and other associations. In that case, their sizes would be rather larger than those displayed by the Local Group dwarf spheroidal (dSph) galaxies. We have detected a few unresolved sources in the sky zone occupied by these galaxies showing colors and brightnesses typical of blue globular clusters. Conclusions: From the comparison of the properties of the galaxies presented in this work with those of similar objects reported in the literature, we have found that LSB galaxies display sizes covering a quite extended continous range (reff 0.3-4.5 kpc), in contrast to "normal" early-type galaxies, which show reff 1.0 kpc with a low dispersion. This fact might point to different formation processes for both types of galaxies.

Application of Early Nutrition Support in Neurosurgical Coma Patients.

PubMed

Ren, Guoqin

2015-12-01

The present study was conducted to investigate the clinical efficacy of early parenteral and enteral nutrition (PN + EN) support in neurosurgical coma patients. Eighty cases of neurosurgical coma patients were randomly divided into intervention group and control group. The intervention group received early PN + EN support, and the control group received only total enteral nutritional (TEN) support. The levels of hemoglobin (HGB), serum albumin (ALB), prealbumin (PA), and retinol-binding protein (RBP) in two groups on days 1, 10, and 20 were observed. The incidences of pneumonia, stress ulcer, abnormal liver function, abdominal distension, and diarrhea between two groups were also compared. Results found that, on day 10, compared with the control group, the levels of HGB, PA, and RBP in the intervention group were significantly increased (P < 0.05). On day 20, ALB in the intervention group significantly increased (P < 0.05), and the incidences of pneumonia, abdominal distension, and diarrhea in the intervention group were significantly lower than those in the control group (P < 0.05). Compared with only TEN support, early PN + EN support can obviously improve the nutritional status of neurosurgical coma patients and reduce the occurrence of complications.

Testing a generalized cubic Galileon gravity model with the Coma Cluster

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

Terukina, Ayumu; Yamamoto, Kazuhiro; Okabe, Nobuhiro

2015-10-01

We obtain a constraint on the parameters of a generalized cubic Galileon gravity model exhibiting the Vainshtein mechanism by using multi-wavelength observations of the Coma Cluster. The generalized cubic Galileon model is characterized by three parameters of the turning scale associated with the Vainshtein mechanism, and the amplitude of modifying a gravitational potential and a lensing potential. X-ray and Sunyaev-Zel'dovich (SZ) observations of the intra-cluster medium are sensitive to the gravitational potential, while the weak-lensing (WL) measurement is specified by the lensing potential. A joint fit of a complementary multi-wavelength dataset of X-ray, SZ and WL measurements enables us tomore » simultaneously constrain these three parameters of the generalized cubic Galileon model for the first time. We also find a degeneracy between the cluster mass parameters and the gravitational modification parameters, which is influential in the limit of the weak screening of the fifth force.« less

A Massive Warm Baryonic Halo in the Coma Cluster

NASA Technical Reports Server (NTRS)

Bonamente, Massimiliano; Joy, Marshall K.; Lieu, Richard

2003-01-01

Several deep PSPC observations of the Coma Cluster reveal a very large scale halo of soft X-ray emission, substantially in excess of the well-known radiation from the hot intracluster medium. The excess emission, previously reported in the central region of the cluster using lower sensitivity Extreme Ultraviolet Explorer (EUVE) and ROSAT data, is now evident out to a radius of 2.6 Mpc, demonstrating that the soft excess radiation from clusters is a phenomenon of cosmological significance. The X-ray spectrum at these large radii cannot be modeled nonthermally but is consistent with the original scenario of thermal emission from warm gas at approx. 10(exp 6) K. The mass of the warm gas is on par with that of the hot X-ray-emitting plasma and significantly more massive if the warm gas resides in low-density filamentary structures. Thus, the data lend vital support to current theories of cosmic evolution, which predict that at low redshift approx. 30%-40% of the baryons reside in warm filaments converging at clusters of galaxies.

Quenching of the Star Formation Activity of Galaxies in Dense Environments

NASA Astrophysics Data System (ADS)

Boselli, A.

2017-12-01

The nearby Universe is an ideal laboratory to study the effects of the environments on galaxy evolution. We have analysed the multifrequency properties of galaxies in the nearby clusters Virgo, Coma, and A1367. We have shown that the HI gas content and the activity of star formation of the late-type galaxies start to gradually decrease inwards ˜ one virial radius. We have also shown that late-type galaxies in these clusters have truncated HI, H_2, dust, and star forming discs once the HI gas content is removed by the harsh environment. Some of these galaxies also exibit spectacular tails of atomic neutral, ionised, or hot gas without any counterpart in the stellar component. All this evidence favors ram pressure stripping as the dominant mechanism responsible for the gas removal from the disc, and for the following quenching of the star formation activity.

Nonthermal Particles and Radiation Produced by Cluster Merger Shocks

DTIC Science & Technology

2003-09-10

NONTHERMAL PARTICLES AND RADIATION PRODUCED BY CLUSTER MERGER SHOCKS Robert C. Berrington and Charles D. Dermer Naval Research Laboratory, Code 7653...of the merging cluster and is assumed to be constant as the shock propagates outward from the cluster center. In this paper , we model the cluster ...emission in the60–250 eV band for a number of clus- ters. These clusters include Virgo , Coma, Fornax, A2199, A1795, and A4059 (Lieu et al. 1996a, 1996b

[Myxedema coma].

PubMed

Rizzo, Leonardo F L; Mana, Daniela L; Bruno, Oscar D; Wartofsky, Leonard

2017-01-01

Hypothyroidism is a frequently diagnosed and simply treated disease. If not recognised, however, in time it may develop into the most severe manifestation of hypothyroidism known as myxedema coma. The term "myxedema coma" is generally seen as misleading since most patients do not initially present in a coma. The typical progression is lethargy evolving into stupor and, eventually, into coma with respiratory failure and hypothermia. It mainly affects elderly women, often occurring in winter and is relatively rare. It can be considered a form of decompensated hypothyroidism often triggered by a variety of non-thyroid conditions or diseases provoking an extremely severe condition of multiple system failure with lethal consequences unless an early diagnosis is made and an aggressive treatment is administered.

The NGC 4839 group falling into the Coma cluster observed by XMM-Newton

NASA Astrophysics Data System (ADS)

Neumann, D. M.; Arnaud, M.; Gastaud, R.; Aghanim, N.; Lumb, D.; Briel, U. G.; Vestrand, W. T.; Stewart, G. C.; Molendi, S.; Mittaz, J. P. D.

2001-01-01

We present here the first analysis of the XMM-Newton EPIC-MOS data of the galaxy group around NGC 4839, which lies at a projected distance to the Coma cluster center of 1.6h50-1 Mpc. In our analysis, which includes imaging, spectro-imaging and spectroscopy we find compelling evidence for the sub group being on its first infall onto the Coma cluster. The complex temperature structure around NGC 4839 is consistent with simulations of galaxies falling into a cluster environment. We see indications of a bow shock and of ram pressure stripping around NGC 4839. Furthermore our data reveal a displacement between NGC 4839 and the center of the hot gas in the group of about 300h50-1 kpc. With a simple approximation we can explain this displacement by the pressure force originating from the infall, which acts much stronger on the group gas than on the galaxies. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). EPIC was developed by the EPIC Consortium led by the Principal Investigator, Dr. M. J. L. Turner. The consortium comprises the following Institutes: University of Leicester, University of Birmingham, (UK); CEA/Saclay, IAS Orsay, CESR Toulouse, (France); IAAP Tuebingen, MPE Garching, (Germany); IFC Milan, ITESRE Bologna, IAUP Palermo, Italy. EPIC is funded by: PPARC, CEA, CNES, DLR and ASI.

Hyperosmolar diabetic non-ketotic coma, hyperkalaemia and an unusual near death experience.

PubMed

Ting, J Y

2001-03-01

Generally, cardiac arrest due to pulseless electrical activity has a poor outcome, except when reversible factors such as acute hyperkalaemia are identified and managed early. Hyperosmolar diabetic non-ketotic coma may lead to acute hyperkalaemia. Hyperosmolar diabetic non-ketotic coma is a metabolic emergency usually seen in elderly non-insulin dependent diabetics, characterized by severe hyperglycaemia, volume depletion, altered consciousness, confusion and less frequently neurological deficit. Cerebrovascular accident or transient ischaemic attack may be mistakenly diagnosed, particularly if the patient has no history of diabetes mellitus. Delays in diagnosis and management of glycaemic emergencies presenting as a constellation of neurological abnormalities can be avoided by routine early measurement of blood glucose. Hyperosmolar diabetic non-ketotic coma should be considered in any patient with altered consciousness or neurologic deficit in conjunction with hyperglycaemia. As hyperosmolar diabetic non-ketotic coma results in severe fluid depletion, electrolyte disturbance, profound hyperglycaemia and an altered mental state, the guiding principles of therapy include aggressive rehydration, insulin therapy, correction of electrolyte abnormalities and treatment of any underlying illnesses. Treatment of acute hyperkalaemia includes calcium ions, insulin with dextrose, salbutamol and haemodialysis.

[The coma awakening unit, between intensive care and rehabilitation].

PubMed

Mimouni, Arnaud

2015-01-01

After intensive care and before classic neurological rehabilitation is possible, patients in an altered state of consciousness are cared for at early stages in so-called coma awakening units. The care involves, on the one hand, the complex support of the patient's awakening from coma as a neurological and existential process, and on the other, support for their families. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The X-ray structure of a galaxy cluster at z = 0.54 - Implications for cluster evolution and cosmology

NASA Technical Reports Server (NTRS)

White, S. D. M.; Silk, J.; Henry, J. P.

1981-01-01

High-resolution X-ray observations of the rich cluster 0016+16 at a redshift of 0.541 are presented. The emitting gas in this cluster is hot and extremely luminous, and its structure resembles that seen in the brightest nearby cluster sources. In most of its properties, 0016+16 resembles a richer version of the Coma cluster, and it offers little support to the hypothesis that clusters at z greater than 0.5 differ fundamentally from nearer objects.

Energy spectra of X-ray clusters of galaxies

NASA Technical Reports Server (NTRS)

Avni, Y.

1976-01-01

A procedure for estimating the ranges of parameters that describe the spectra of X-rays from clusters of galaxies is presented. The applicability of the method is proved by statistical simulations of cluster spectra; such a proof is necessary because of the nonlinearity of the spectral functions. Implications for the spectra of the Perseus, Coma, and Virgo clusters are discussed. The procedure can be applied in more general problems of parameter estimation.

Bright end of the color-magnitude relation for cD, E and S0 galaxies

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

Lugger, P.M.

1979-11-01

Schild and Davis's (Astron. J. 84, 311 (1979)) galaxy photometry for cD's in poor clusters is compared with Sandage's (Astrophys. J. 176, 21(1979)) color-magnitude relation defined by elliptical and S0 galaxies in the Virgo and Coma clusters. The cD galaxies are found to be somewhat bluer on average than galaxies of similar magnitude in the Virgo and Coma sample, consistent with the predictions of the galactic cannibalism model proposed by Hausman and Ostriker (Astrophys. J. 224, 320 (1978)). However, a more uniform selection of galaxy photometry is required before any definitive conclusions regarding the bright end of the color-magnitude relationmore » can be made.« less

A NuSTAR OBSERVATION OF THE CENTER OF THE COMA CLUSTER

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

Gastaldello, Fabio; Molendi, S.; Wik, Daniel R.

2015-02-20

We present the results of a 55 ks NuSTAR observation of the core of the Coma Cluster. The global spectrum can be explained by thermal gas emission, with a conservative 90% upper limit to non-thermal inverse Compton (IC) emission of 5.1 × 10{sup –12} erg cm{sup –2} s{sup –1} in a 12' × 12' field of view. The brightness of the thermal component in this central region does not allow more stringent upper limits on the IC component when compared with non-imaging instruments with much larger fields of view where claims of detections have been made. Future mosaic NuSTAR observations ofmore » Coma will further address this issue. The temperature map shows a relatively uniform temperature distribution with a gradient from the hot northwest side to the cooler southeast, in agreement with previous measurements. The temperature determination is robust given the flat effective area and low background in the 3-20 keV band, making NuSTAR an ideal instrument to measure high temperatures in the intracluster medium.« less

A NuSTAR observation of the center of the Coma Cluster

DOE PAGES

Gastaldello, Fabio; Wik, Daniel R.; Molendi, S.; ...

2015-02-20

We present the results of a 55 ks NuSTAR observation of the core of the Coma Cluster. The global spectrum can be explained by thermal gas emission, with a conservative 90% upper limit to non-thermal inverse Compton (IC) emission of 5.1 × 10 –12 erg cm –2 s –1 in a 12' × 12' field of view. The brightness of the thermal component in this central region does not allow more stringent upper limits on the IC component when compared with non-imaging instruments with much larger fields of view where claims of detections have been made. Future mosaic NuSTAR observationsmore » of Coma will further address this issue. In addition, the temperature map shows a relatively uniform temperature distribution with a gradient from the hot northwest side to the cooler southeast, in agreement with previous measurements. The temperature determination is robust given the flat effective area and low background in the 3-20 keV band, making NuSTAR an ideal instrument to measure high temperatures in the intracluster medium.« less

The Expansion of Clusters of Galaxies

DTIC Science & Technology

1961-01-01

investigators, currently we have usable data for a number of other clusters and groups. It is true that, with the exception of the Virgo Cluster , in each case...progress. Throughout this paper , the term "system of galaxies" is used as a synonym of the term " cluster " appearing in the theory of the spatial...mentioned at the beginning of the paper . Whether these outliers should be treated as members of the Coma Cluster or not is a subjective matter and

The Inner Coma Physical Environments of Ecliptic Comets 45P/Honda-Mrkos-Pajdusakova, 2P/Encke, and 41P/Tuttle-Giacobini-Kresak Revealed Through Long-Slit Spectroscopy at NASA IRTF

NASA Astrophysics Data System (ADS)

Bonev, Boncho P.; DiSanti, Michael A.; Roth, Nathan; Dello Russo, Neil; Vervack, Ronald J.; Gibb, Erika L.; Villanueva, Geronimo Luis; Combi, Michael R.; Fougere, Nicolas; Kawakita, Hideyo; McKay, Adam J.; Saki, Mohammad; Cordiner, Martin; Protopapa, Silvia; de Val-Borro, Miguel

2017-10-01

Understanding the physical processes in the inner regions of cometary atmospheres is vital for interpretation of molecular cometary emission at all wavelengths. Furthermore, because ecliptic comets are continuously evaluated as space mission targets, understanding their coma environments is a central theme in both enhancing the science return of past missions (EPOXI, Rosetta) and in selecting future mission targets. With this motivation, we report long-slit high-resolution observations of H2O emission in the comae of three ecliptic comets observed in early 2017: 45P/Honda-Mrkos-Pajdusakova, 2P/Encke, and 41P/Tuttle-Giacobini-Kresak. Using the new crossed-dispersed spectrograph iSHELL at NASA IRTF, we detected a suite of water rovibrational emission lines from these comets and measured the spatial distributions of H2O rotational temperatures and molecular column densities. Both parameters are highly diagnostic of the physical environment in cometary comae, the competition between cooling and heating processes in these environments, and the presence (or lack thereof) of extended coma sources of gas-phase H2O. Comets 2P and 45P allowed a rare glimpse into coma physics at small (< 0.6 AU) heliocentric distances, where photochemical heating is particularly important, but direct H2O observations have been sparse. Our results add to the small sample of spatial-spectral measurements of this type. They will be discussed in the context of coma physics models along with prospects for investigations during the upcoming favorable apparitions of ecliptic comets 21P/Giacobini-Zinner and 46P/Wirtanen. We gratefully acknowledge support from the NASA Solar System Workings, Planetary Atmospheres, Earth and Space Science Fellowship, Solar System Observations, Emerging Worlds, and Astrobiology Programs, and NSF Solar and Planetary Research Grants. We are grateful to the entire IRTF staff for their help with these challenging observations, most of which were done during daytime.

Ultra-diffuse cluster galaxies as key to the MOND cluster conundrum

NASA Astrophysics Data System (ADS)

Milgrom, Mordehai

2015-12-01

Modified Newtonian Dynamics (MOND) reduces greatly the mass discrepancy in clusters of galaxies,but does leave a global discrepancy of about a factor of 2 (epitomized by the structure of the Bullet Cluster). It has been proposed, within the minimalist and purist MOND, that clusters harbour some indigenous, yet undetected, cluster baryonic (dark) matter (CBDM), whose total amount is comparable with that of the observed hot gas. Koda et al. have recently identified more than a thousand ultra-diffuse, galaxy-like objects (UDGs) in the Coma cluster. These, they argue, require, within Newtonian dynamics, that they are much more massive than their observed stellar component. Here, I propound that some of the CBDM is internal to UDGs, which endows them with robustness. The rest of the CBDM objects formed in now-disrupted kin of the UDGs, and is dispersed in the intracluster medium. The discovery of cluster UDGs is not in itself a resolution of the MOND cluster conundrum, but it lends greater plausibility to CBDM as its resolution. Alternatively, if the UDGs are only now falling into Coma, their large size and very low surface brightness could result from the inflation due to the MOND, variable external-field effect (EFE). I also consider briefly solutions to the conundrum that invoke more elaborate extensions of purist MOND, e.g. that in clusters, the MOND constant takes up larger than canonical values of the MOND constant. Whatever solves the cluster conundrum within MOND might also naturally account for UDGs.

Spectroscopic characterisation of the stellar content of ultra diffuse galaxies

NASA Astrophysics Data System (ADS)

Ruiz-Lara, T.; Beasley, M. A.; Falcón-Barroso, J.; Román, J.; Pinna, F.; Brook, C.; Di Cintio, A.; Martín-Navarro, I.; Trujillo, I.; Vazdekis, A.

2018-05-01

Understanding the peculiar properties of Ultra Diffuse Galaxies (UDGs) via spectroscopic analysis is a challenging task requiring very deep observations and exquisite data reduction. In this work we perform one of the most complete characterisations of the stellar component of UDGs to date using deep optical spectroscopic data from OSIRIS at GTC. We measure radial and rotation velocities, star formation histories (SFH) and mean population parameters, such as ages and metallicities, for a sample of five UDG candidates in the Coma cluster. From the radial velocities, we confirm the Coma membership of these galaxies. We find that their rotation properties, if detected at all, are compatible with dwarf-like galaxies. The SFHs of the UDG are dominated by old (˜ 7 Gyr), metal-poor ([M/H] ˜ -1.1) and α-enhanced ([Mg/Fe] ˜ 0.4) populations followed by a smooth or episodic decline which halted ˜ 2 Gyr ago, possibly a sign of cluster-induced quenching. We find no obvious correlation between individual SFH shapes and any UDG morphological properties. The recovered stellar properties for UDGs are similar to those found for DDO 44, a local UDG analogue resolved into stars. We conclude that the UDGs in our sample are extended dwarfs whose properties are likely the outcome of both internal processes, such as bursty SFHs and/or high-spin haloes, as well as environmental effects within the Coma cluster.

Deep X-ray and UV Surveys of Galaxies with Chandra, XMM-Newton, and GALEX

NASA Technical Reports Server (NTRS)

Hornschemeier, Ann

2006-01-01

Only with the deepest Chandra surveys has X-ray emission from normal and star forming galaxies (as opposed to AGN, which dominate the X-ray sky) been accessible at cosmologically interesting distances. The X-ray emission from accreting binaries provide a critical glimpse into the binary phase of stellar evolution and studies of the hot gas reservoir constrain past star formation. UV studies provide important, sensitive diagnostics of the young star forming populations and provide the most mature means for studying galaxies at 2 < zeta < 4. This talk will review current progress on studying X-ray emission in concert with UV emission from normal/star-forming galaxies at higher redshift. We will also report on our new, deep surveys with GALEX and XMM-Newton in the nearby Coma cluster. These studies are relevant to DEEP06 as Coma is the nearest rich cluster of galaxies and provides an important benchmark for high-redshift studies in the X-ray and UV wavebands. The 30 ks GALEX (note: similar depth to the GALEX Deep Imaging Survey) and the 110 ks XMM observations provide extremely deep coverage of a Coma outskirts field, allowing the construction of the UV and X-ray luminosity function of galaxies and important constraints on star formation scaling relations such as the X-ray-Star Formation Rate correlation and the X-ray/Stellar Mass correlation. We will discuss what we learn from these deep observations of Coma, including the recently established suppression of the X-ray emission from galaxies in the Coma outskirts that is likely associated with lower levels of past star formation and/or the results of tidal gas stripping.

Studies of the Virgo cluster. VI - Morphological and kinematical structure of the Virgo cluster

NASA Technical Reports Server (NTRS)

Binggeli, Bruno; Tammann, G. A.; Sandage, Allan

1987-01-01

The structure of the Virgo cluster is analyzed on the basis of the positions, Hubble types, and radial velocities of 1277 Virgo cluster galaxies. The surface distribution of galaxies is considered according to type, and is discussed using maps, isopleths, strip counts, and radial-density distributions. It is found that the Virgo cluster shows pronounced double structure. The main concentration has a large velocity dispersion and is made up predominantly of early-type galaxies, while the secondary concentration has a much smaller velocity dispersion and contains late types. There is a strong spatial segregation of the Hubble types, the early-type galaxies being more concentrated toward the cluster center. There is significant substructure in the cluster core. The irregularity of the Virgo cluster in both configuration and velocity space shows that the core and the envelope are still forming, and hence that the cluster is young.

The Problem of Hipparcos Distances to Open Clusters. Report 1; Constraints from Multicolor a Main-Sequence Fitting

NASA Technical Reports Server (NTRS)

Pinsonneault, Marc H.; Stauffer, John; Soderblom, David R.; King, Jeremy R.; Hanson, Robert B.

1998-01-01

Parallax data from the Hipparcos mission allow the direct distance to open clusters to be compared with the distance inferred from main-sequence (MS) fitting. There are surprising differences between the two distance measurements. indicating either the need for changes in the cluster compositions or reddening, underlying problems with the technique of MS fitting, or systematic errors in the Hipparcos parallaxes at the 1 mas level. We examine the different possibilities, focusing on MS fitting in both metallicity-sensitive B-V and metallicity-insensitive V-I for five well-studied systems (the Hyades, Pleiades, alpha Per, Praesepe, and Coma Ber). The Hipparcos distances to the Hyades and alpha Per are within 1 sigma of the MS-fitting distance in B-V and V-I, while the Hipparcos distances to Coma Ber and the Pleiades are in disagreement with the MS-fitting distance at more than the 3 sigma level. There are two Hipparcos measurements of the distance to Praesepe; one is in good agreement with the MS-fitting distance and the other disagrees at the 2 sigma level. The distance estimates from the different colors are in conflict with one another for Coma but in agreement for the Pleiades. Changes in the relative cluster metal abundances, age related effects, helium, and reddening are shown to be unlikely to explain the puzzling behavior of the Pleiades. We present evidence for spatially dependent systematic errors at the 1 mas level in the parallaxes of Pleiades stars. The implications of this result are discussed.

MAPPING THE GAS TURBULENCE IN THE COMA CLUSTER: PREDICTIONS FOR ASTRO-H

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

ZuHone, J. A.; Markevitch, M.; Zhuravleva, I.

2016-02-01

Astro-H will be able for the first time to map gas velocities and detect turbulence in galaxy clusters. One of the best targets for turbulence studies is the Coma cluster, due to its proximity, absence of a cool core, and lack of a central active galactic nucleus. To determine what constraints Astro-H will be able to place on the Coma velocity field, we construct simulated maps of the projected gas velocity and compute the second-order structure function, an analog of the velocity power spectrum. We vary the injection scale, dissipation scale, slope, and normalization of the turbulent power spectrum, andmore » apply measurement errors and finite sampling to the velocity field. We find that even with sparse coverage of the cluster, Astro-H will be able to measure the Mach number and the injection scale of the turbulent power spectrum—the quantities determining the energy flux down the turbulent cascade and the diffusion rate for everything that is advected by the gas (metals, cosmic rays, etc.). Astro-H will not be sensitive to the dissipation scale or the slope of the power spectrum in its inertial range, unless they are outside physically motivated intervals. We give the expected confidence intervals for the injection scale and the normalization of the power spectrum for a number of possible pointing configurations, combining the structure function and velocity dispersion data. Importantly, we also determine that measurement errors on the line shift will bias the velocity structure function upward, and show how to correct this bias.« less

Mapping the Gas Turbulence in the Coma Cluster: Predictions for Astro-H

NASA Technical Reports Server (NTRS)

ZuHone, J. A.; Markevitch, M.; Zhuravleva, I.

2016-01-01

Astro-H will be able for the first time to map gas velocities and detect turbulence in galaxy clusters. One of the best targets for turbulence studies is the Coma cluster, due to its proximity, absence of a cool core, and lack of a central active galactic nucleus. To determine what constraints Astro-H will be able to place on the Coma velocity field, we construct simulated maps of the projected gas velocity and compute the second-order structure function, an analog of the velocity power spectrum. We vary the injection scale, dissipation scale, slope, and normalization of the turbulent power spectrum, and apply measurement errors and finite sampling to the velocity field. We find that even with sparse coverage of the cluster, Astro-H will be able to measure the Mach number and the injection scale of the turbulent power spectrum-the quantities determining the energy flux down the turbulent cascade and the diffusion rate for everything that is advected by the gas (metals, cosmic rays, etc.). Astro-H will not be sensitive to the dissipation scale or the slope of the power spectrum in its inertial range, unless they are outside physically motivated intervals. We give the expected confidence intervals for the injection scale and the normalization of the power spectrum for a number of possible pointing configurations, combining the structure function and velocity dispersion data. Importantly, we also determine that measurement errors on the line shift will bias the velocity structure function upward, and show how to correct this bias.

Mass concentrations associated with extended X-ray sources in the core of the Coma cluster

NASA Technical Reports Server (NTRS)

Vikhlinin, A.; Forman, W.; Jones, C.

1994-01-01

Using a deep (approx. 20,200 s) ROSAT Position Sensitive Proportional Counter (PSPC) image we have examined the central region of the Coma cluster. Two extended regions of enhanced X-ray emission are found, centered at the positions of the brightest elliptical galaxies in the cluster: NGC 4874 and NGC 4889. Spectral analysis of the sources reveals no evidence of any difference between the spectra of these sources and that of the surrounding cluster emission. We assume that the enhancement in the X-ray surface brightness results from gas density enhancements and also that the underlying mass concentrations lie either at the cluster center or 1 core radius out of the center (420 kpc). With these assumptions, we derive total masses of 1.2 x 10(exp 13) - 1.6 x 10(exp 13), and 0.9 x 10(exp 13) - 1.8 x 10(exp 13) Solar mass within 2 min (80 kpc) of NGC 4874 and NGC 4889, respectively, assuming a Hubble constant H(sub 0) = 50 km/s/Mpc. Corresponding mass-to-light ratios for the galaxies are 30-40 and 25-50 in solar units, increasing at larger radii and approaching the values derived for the entire cluster at distances of more than approximately 150 kpc from the galaxies.

Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Hässig, M.; Altwegg, K.; Balsiger, H.; Bar-Nun, A.; Berthelier, J. J.; Bieler, A.; Bochsler, P.; Briois, C.; Calmonte, U.; Combi, M.; De Keyser, J.; Eberhardt, P.; Fiethe, B.; Fuselier, S. A.; Galand, M.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Jäckel, A.; Keller, H. U.; Kopp, E.; Korth, A.; Kührt, E.; Le Roy, L.; Mall, U.; Marty, B.; Mousis, O.; Neefs, E.; Owen, T.; Rème, H.; Rubin, M.; Sémon, T.; Tornow, C.; Tzou, C.-Y.; Waite, J. H.; Wurz, P.

2015-01-01

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface.

Globular clusters and environmental effects in galaxy clusters

NASA Astrophysics Data System (ADS)

Sales, Laura

2016-10-01

Globular clusters are old compact stellar systems orbiting around galaxies of all types. Tens of thousands of them can also be found populating the intra-cluster regions of nearby galaxy clusters like Virgo and Coma. Thanks to the HST Frontier Fields program, GCs are starting now to be detected also in intermediate redshift clusters. Yet, despite their ubiquity, a theoretical model for the formation and evolution of GCs is still missing, especially within the cosmological context.Here we propose to use cosmological hydrodynamical simulations of 18 galaxy clusters coupled to a post-processing GC formation model to explore the assembly of galaxies in clusters together with their expected GC population. The method, which has already been implemented and tested, will allow us to characterize for the first time the number, radial distribution and kinematics of GCs in clusters, with products directly comparable to observational maps. We will explore cluster-to-cluster variations and also characterize the build up of the intra-cluster component of GCs with time.As the method relies on a detailed study of the star-formation history of galaxies, we will jointly constrain the predicted quenching time-scales for satellites and the occurrence of starburst events associated to infall and orbital pericenters of galaxies in massive clusters. This will inform further studies on the distribution, velocity and properties of post-starburst galaxies in past, ongoing and future HST programs.

Contemporary approach to neurologic prognostication of coma after cardiac arrest.

PubMed

Ben-Hamouda, Nawfel; Taccone, Fabio S; Rossetti, Andrea O; Oddo, Mauro

2014-11-01

Coma after cardiac arrest (CA) is an important cause of admission to the ICU. Prognosis of post-CA coma has significantly improved over the past decade, particularly because of aggressive postresuscitation care and the use of therapeutic targeted temperature management (TTM). TTM and sedatives used to maintain controlled cooling might delay neurologic reflexes and reduce the accuracy of clinical examination. In the early ICU phase, patients' good recovery may often be indistinguishable (based on neurologic examination alone) from patients who eventually will have a poor prognosis. Prognostication of post-CA coma, therefore, has evolved toward a multimodal approach that combines neurologic examination with EEG and evoked potentials. Blood biomarkers (eg, neuron-specific enolase [NSE] and soluble 100-β protein) are useful complements for coma prognostication; however, results vary among commercial laboratory assays, and applying one single cutoff level (eg, > 33 μg/L for NSE) for poor prognostication is not recommended. Neuroimaging, mainly diffusion MRI, is emerging as a promising tool for prognostication, but its precise role needs further study before it can be widely used. This multimodal approach might reduce false-positive rates of poor prognosis, thereby providing optimal prognostication of comatose CA survivors. The aim of this review is to summarize studies and the principal tools presently available for outcome prediction and to describe a practical approach to the multimodal prognostication of coma after CA, with a particular focus on neuromonitoring tools. We also propose an algorithm for the optimal use of such multimodal tools during the early ICU phase of post-CA coma.

[Analysis of Time-to-onset of Interstitial Lung Disease after the Administration of Small Molecule Molecularly-targeted Drugs].

PubMed

Komada, Fusao

2018-01-01

　The aim of this study was to investigate the time-to-onset of drug-induced interstitial lung disease (DILD) following the administration of small molecule molecularly-targeted drugs via the use of the spontaneous adverse reaction reporting system of the Japanese Adverse Drug Event Report database. DILD datasets for afatinib, alectinib, bortezomib, crizotinib, dasatinib, erlotinib, everolimus, gefitinib, imatinib, lapatinib, nilotinib, osimertinib, sorafenib, sunitinib, temsirolimus, and tofacitinib were used to calculate the median onset times of DILD and the Weibull distribution parameters, and to perform the hierarchical cluster analysis. The median onset times of DILD for afatinib, bortezomib, crizotinib, erlotinib, gefitinib, and nilotinib were within one month. The median onset times of DILD for dasatinib, everolimus, lapatinib, osimertinib, and temsirolimus ranged from 1 to 2 months. The median onset times of the DILD for alectinib, imatinib, and tofacitinib ranged from 2 to 3 months. The median onset times of the DILD for sunitinib and sorafenib ranged from 8 to 9 months. Weibull distributions for these drugs when using the cluster analysis showed that there were 4 clusters. Cluster 1 described a subgroup with early to later onset DILD and early failure type profiles or a random failure type profile. Cluster 2 exhibited early failure type profiles or a random failure type profile with early onset DILD. Cluster 3 exhibited a random failure type profile or wear out failure type profiles with later onset DILD. Cluster 4 exhibited an early failure type profile or a random failure type profile with the latest onset DILD.

Galaxy clusters in local Universe simulations without density constraints: a long uphill struggle

NASA Astrophysics Data System (ADS)

Sorce, Jenny G.

2018-06-01

Galaxy clusters are excellent cosmological probes provided that their formation and evolution within the large scale environment are precisely understood. Therefore studies with simulated galaxy clusters have flourished. However detailed comparisons between simulated and observed clusters and their population - the galaxies - are complicated by the diversity of clusters and their surrounding environment. An original way initiated by Bertschinger as early as 1987, to legitimize the one-to-one comparison exercise down to the details, is to produce simulations constrained to resemble the cluster under study within its large scale environment. Subsequently several methods have emerged to produce simulations that look like the local Universe. This paper highlights one of these methods and its essential steps to get simulations that not only resemble the local Large Scale Structure but also that host the local clusters. It includes a new modeling of the radial peculiar velocity uncertainties to remove the observed correlation between the decreases of the simulated cluster masses and of the amount of data used as constraints with the distance from us. This method has the particularity to use solely radial peculiar velocities as constraints: no additional density constraints are required to get local cluster simulacra. The new resulting simulations host dark matter halos that match the most prominent local clusters such as Coma. Zoom-in simulations of the latter and of a volume larger than the 30h-1 Mpc radius inner sphere become now possible to study local clusters and their effects. Mapping the local Sunyaev-Zel'dovich and Sachs-Wolfe effects can follow.

Structure of Cometary Dust Particles

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, A. C.; Hadamcik, E.; Lasue, J.

2004-11-01

The recent encounter of Stardust with comet 81P/Wild 2 has provided highly spatially resolved data about dust particles in the coma. They show intense swarms and bursts of particles, suggest the existence of fragmenting low-density particles formed of higher density sub-micrometer components [1], and definitely confirm previous results (inferred from Giotto encounter with comet Grigg-Skjellerup [2] and remote light scattering observations [3]). The light scattering properties (mostly polarization, which does not depend upon disputable normalizations) of dust in cometary comae will be summarized, with emphasis on the spatial changes and on the wavelength and phase angle dependence. Experimental and numerical simulations are needed to translate these observed light scattering properties in terms of physical properties of the dust particles (e.g. size, morphology, albedo, porosity). New experimental simulations (with fluffy mixtures of sub-micron sized silica and carbon grains) and new numerical simulations (with fractal aggregates of homogeneous or core-mantled silicate and organic grains) will be presented. The results are in favor of highly porous particles built up (by ballistic-cluster-cluster agglomeration) from grains of interstellar origin. The perspectives offered by laboratory simulations with aggregates built under conditions representative of the early solar system on board the International Space Station will be presented, together with the perspectives offered by future experiments on board the Rosetta cometary probe. Supports from CNES and ESA are acknowledged [1] Tuzzolino et al., Science, 304, 1776, 2004, [2] N. McBride et al., Mon. Not. R. Astron. Soc., 289, p. 535-553, 1997, [3] Levasseur-Regourd and Hadamcik, J. Quant. Spectros. Radiat. Transfer, 79-80, 903-910, 2003.

Immediate coma and poor outcome in subarachnoid haemorrhage are independently associated with an aneurysmal origin.

PubMed

Tsermoulas, Georgios; Flett, Lisa; Gregson, Barbara; Mitchell, Patrick

2013-08-01

Subarachnoid haemorrhage (SAH) may present with coma and this is known to be associated with aneurysmal origin and blood load. Aneurysmal origin is associated with increased blood load and existing data do not allow us to determine if the association between coma and aneurysmal SAH is wholly due to blood load or if aneurysmal origin has an additional independent effect. The objective of our study is to find if an aneurysmal origin is a predictor of acute onset of coma independent of blood load. A series of consecutive patients with spontaneous SAH were divided into two groups: aneurysmal (aSAH) and non-aneurysmal--angiographically negative SAH (naSAH). Blood load was quantified so that the effect of aneurysmal origin could be resolved from the effect of the amount of blood spilled. Non-parametric regression was used to relate blood load to coma and poor outcome rates for aneurysmal bleeds. We analysed a total of 421 patients presenting during the period 2009-2011. Ninety aneurysmal cases presented with coma, seventy immediately in the early phase and seven shortly after rebleeding. None of the naSAH cases presented with immediate coma and 1 developed delayed coma. Delayed coma was associated with acute hydrocephalus in both groups. Aneurysmal origin was found to be an independent determinant of immediate coma (p=0.02) and poor outcome (p<0.001). Immediate coma and poor outcome in SAH are associated with an aneurysmal origin and do not characterize naSAH. Copyright © 2013 Elsevier B.V. All rights reserved.

Mid-infrared spectra of comet nuclei

NASA Astrophysics Data System (ADS)

Kelley, Michael S. P.; Woodward, Charles E.; Gehrz, Robert D.; Reach, William T.; Harker, David E.

2017-03-01

Comet nuclei and D-type asteroids have several similarities at optical and near-IR wavelengths, including near-featureless red reflectance spectra, and low albedos. Mineral identifications based on these characteristics are fraught with degeneracies, although some general trends can be identified. In contrast, spectral emissivity features in the mid-infrared provide important compositional information that might not otherwise be achievable. Jovian Trojan D-type asteroids have emissivity features strikingly similar to comet comae, suggesting that they have the same compositions and that the surfaces of the Trojans are highly porous. However, a direct comparison between a comet and asteroid surface has not been possible due to the paucity of spectra of comet nuclei at mid-infrared wavelengths. We present 5-35 μm thermal emission spectra of comets 10P/Tempel 2, and 49P/Arend-Rigaux observed with the Infrared Spectrograph on the Spitzer Space Telescope. Our analysis reveals no evidence for a coma or tail at the time of observation, suggesting the spectra are dominated by the comet nucleus. We fit each spectrum with the near-Earth asteroid thermal model (NEATM) and find sizes in agreement with previous values. However, the NEATM beaming parameters of the nuclei, 0.74-0.83, are systematically lower than the Jupiter-family comet population mean of 1.03 ± 0.11, derived from 16- and 22-μm photometry. We suggest this may be either an artifact of the spectral reduction, or the consequence of an emissivity low near 16 μm. When the spectra are normalized by the NEATM model, a weak 10-μm silicate plateau is evident, with a shape similar to those seen in mid-infrared spectra of D-type asteroids. A silicate plateau is also evident in previously published Spitzer spectra of the nucleus of comet 9P/Tempel 1. We compare, in detail, these comet nucleus emission features to those seen in spectra of the Jovian Trojan D-types (624) Hektor, (911) Agamemnon, and (1172) Aneas, as well as those seen in the spectra of seven comet comae. The comet comae present silicate features with two distinct shapes, either trapezoidal, or more rounded, the latter apparently due to enhanced emission near 8 to 8.5 μm. The surfaces of Tempel 2, Arend-Rigaux, and Hektor best agree with the comae that present trapezoidal features, furthering the hypothesis that the surfaces of these targets must have high porosities in order to exhibit a spectrum similar to a comet coma. An emissivity minimum at 15 μm, present in the spectra of Tempel 2, Arend-Rigaux, Hektor, and Agamemnon, is also described, the origin of which remains unidentified. The compositional similarity between D-type asteroids and comets is discussed, and our data supports the hypothesis that they have similar origins in the early Solar System.

VizieR Online Data Catalog: Gaia DR1 open cluster members (Gaia Collaboration+, 2017)

NASA Astrophysics Data System (ADS)

Gaia Collaboration; van Leeuwen F.; Vallenari, A.; Jordi, C.; Lindegren, L.; Bastian, U.; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Hog, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castaneda, J.; Chaoul, L.; Cheek, N.; de Angeli, F.; Fabricius, C.; Guerra, R.; Hernandez, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Ordonez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thevenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.; Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Fremat, Y.; Garcia-Torres, M.; Gosset, E.; Halbwachs, J.-L.; Hambly, N. C.; Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J.-M.; Recio-Blanco, A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Alvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Anton, S.; Arcay, B.; Bach, N.; Baker, S. G.; Balaguer-Nunez, L.; Barache, C.; Barata, C.; Barbier, A.; Barblan, F.; Barrado, Y. Navascues D.; Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello Garcia, A.; Belokuro, V. V.; Ben Djoya, P.; Berihuete, A.; Bianchi, L.; Bienayme, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Bruesemeister, T.; Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; de Luise, F.; de March, R.; de Martino, D.; de Souza, R.; Debosscher, J.; Del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Duran, J.; Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcao, A. J.; Farras Casas, M.; Federici, L.; Fedorets, G.; Fernandez-Hernandez, J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; Garcia-Sedano, F.; Garofalo, A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; Gonzalez-Marcos, A.; Gonzalez-Nunez, J.; Gonzalez-Vidal, J. J.; Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gurpide, A.; Gutierrez-Sanchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle, G.; Jofre, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.; Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne, J.-B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.; Lecler, C. N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrom, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Loeffler, W.; Lopez, M.; Lorenz, D.; MacDonald, I.; Magalhaes Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni, S.; Marrese, P. M.; Marschalko, G.; Marshall, D. J.; Martin-Fleitas, J. M.; Martino, M.; Mary, N.; Matijevic, G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro, R.; Molinaro, M.; Molnar, L.; Moniez, M.; Montegriffo, P.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordenovic, C.; Ordieres-Mere, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikaeinen, H.; Pichon, B.; Piersimoni, A. M.; Pineau, F.-X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prsa, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Reyle, C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gomez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagrista Selles, T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I.-C.; Smareglia, R.; Smart, R. L.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmueller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Sueveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; van Hemelryck, E.; Vanleeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Wevers, T.; Wyrzykowski, L.; Yoldas, A.; Zerjal, M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim, A.; Anglada-Escude, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck, M.; Bernstein, H.-H.; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P.-M.; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chereau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frezouls, B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.; Gomez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A.-M.; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D.-W.; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; Lebouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A.-T.; Nordlander, T.; O'Flaherty, K. S.; Ocvirk, P.; Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Peturaud, F.; Pieniluoma, T.; Pigozzi, E.; Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.; Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straizys, V.; Ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J.-M.; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.

2017-04-01

We have determined and examined the astrometric data for 19 open clusters, ranging from the Hyades at just under 47pc to NGC 2422 at nearly 440pc. The clusters are : the Hyades, Coma Berenices, the Pleiades, Praesepe, alpha Per, IC 2391, IC 2602, Blanco 1, NGC 2451, NGC 6475, NGC 7092, NGC 2516, NGC 2232, IC 4665, NGC 6633, Collinder 140, NGC 2422, NGC 3532 and NGC 2547. (2 data files).

Evolution of the early-type galaxy fraction in clusters since z = 0.8

NASA Astrophysics Data System (ADS)

Simard, L.; Clowe, D.; Desai, V.; Dalcanton, J. J.; von der Linden, A.; Poggianti, B. M.; White, S. D. M.; Aragón-Salamanca, A.; De Lucia, G.; Halliday, C.; Jablonka, P.; Milvang-Jensen, B.; Saglia, R. P.; Pelló, R.; Rudnick, G. H.; Zaritsky, D.

2009-12-01

We study the morphological content of a large sample of high-redshift clusters to determine its dependence on cluster mass and redshift. Quantitative morphologies are based on PSF-convolved, 2D bulge+disk decompositions of cluster and field galaxies on deep Very Large Telescope FORS2 images of eighteen, optically-selected galaxy clusters at 0.45 < z < 0.80 observed as part of the ESO Distant Cluster Survey (“EDisCS”). Morphological content is characterized by the early-type galaxy fraction f_et, and early-type galaxies are objectively selected based on their bulge fraction and image smoothness. This quantitative selection is equivalent to selecting galaxies visually classified as E or S0. Changes in early-type fractions as a function of cluster velocity dispersion, redshift and star-formation activity are studied. A set of 158 clusters extracted from the Sloan Digital Sky Survey is analyzed exactly as the distant EDisCS sample to provide a robust local comparison. We also compare our results to a set of clusters from the Millennium Simulation. Our main results are: (1) the early-type fractions of the SDSS and EDisCS clusters exhibit no clear trend as a function of cluster velocity dispersion. (2) Mid-z EDisCS clusters around σ = 500 km s-1 have f_et ≃ 0.5 whereas high-z EDisCS clusters have f_et ≃ 0.4. This represents a ~25% increase over a time interval of 2 Gyr. (3) There is a marked difference in the morphological content of EDisCS and SDSS clusters. None of the EDisCS clusters have early-type galaxy fractions greater than 0.6 whereas half of the SDSS clusters lie above this value. This difference is seen in clusters of all velocity dispersions. (4) There is a strong and clear correlation between morphology and star formation activity in SDSS and EDisCS clusters in the sense that decreasing fractions of [OII] emitters are tracked by increasing early-type fractions. This correlation holds independent of cluster velocity dispersion and redshift even though the fraction of [OII] emitters decreases from z ˜0.8 to z ˜ 0.06 in all environments. Our results pose an interesting challenge to structural transformation and star formation quenching processes that strongly depend on the global cluster environment (e.g., a dense ICM) and suggest that cluster membership may be of lesser importance than other variables in determining galaxy properties. Based on observations obtained in visitor and service modes at the ESO Very Large Telescope (VLT) as part of the Large Programme 166.A-0162 (the ESO Distant Cluster Survey). Also 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 proposal 9476. Support for this proposal was provided by NASA through a grant from the Space Telescope Science Institute. Table [see full textsee full textsee full textsee full textsee full text] is only available in electronic form at http://www.aanda.org

Cometary science. Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko.

PubMed

Hässig, M; Altwegg, K; Balsiger, H; Bar-Nun, A; Berthelier, J J; Bieler, A; Bochsler, P; Briois, C; Calmonte, U; Combi, M; De Keyser, J; Eberhardt, P; Fiethe, B; Fuselier, S A; Galand, M; Gasc, S; Gombosi, T I; Hansen, K C; Jäckel, A; Keller, H U; Kopp, E; Korth, A; Kührt, E; Le Roy, L; Mall, U; Marty, B; Mousis, O; Neefs, E; Owen, T; Rème, H; Rubin, M; Sémon, T; Tornow, C; Tzou, C-Y; Waite, J H; Wurz, P

2015-01-23

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface. Copyright © 2015, American Association for the Advancement of Science.

Streaming Clumps Ejection Model and the Heterogeneous Inner Coma of Comet Wild 2

NASA Technical Reports Server (NTRS)

Clark, B. C.; Economou, T. E.; Green, S. F.; Sandford, S. A.; Zolensky, M. E.

2004-01-01

The conventional concept of cometary comae is that they are dominated by fine particulates released individually by sublimation of surface volatiles and subsequent entrainment in the near-surface gas. It has long been recognized that such particulates could be relatively large, with early estimates that objects perhaps up to one meter in size may be levitated from the surface of the typical cometary nucleus. However, the general uniformity and small average particulate size of observed comae and the relatively smooth, monotonic increases and decreases in particle density during the Giotto flythrough of comet Halley s coma in 1986 reinforced the view that the bulk of the particles are released at the surface, are fine-sized and inert. Jets have been interpreted as geometrically constrained release of these particulates. With major heterogeneities observed during the recent flythrough of the inner coma of comet Wild 2, these views deserve reconsideration.

The Hunt for Missing Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-11-01

Theories of galaxy formation and evolution predict that there should be significantly more dwarf galaxies than have been observed. Are our theories wrong? Or are dwarf galaxies just difficult to detect? Recent results from a survey of a galaxy cluster 62 million light-years away suggest there may be lots of undiscovered dwarf galaxies hiding throughout the universe!Hiding in FaintnessThe missing dwarf problem has had hints of a resolution with the recent discovery of Ultra-Diffuse Galaxies (UDGs) in the Coma and Virgo galaxy clusters. UDGs have low masses and large radii, resulting in a very low surface brightness that makes them extremely difficult to detect. If many dwarfs are UDGs, this could well explain why weve been missing them!But the Coma and Virgo galaxy clusters are similar in that theyre both very massive. Are there UDGs in other galaxy clusters as well? To answer this question, an international team of scientists is running the Next Generation Fornax Survey (NGFS), a survey searching for faint dwarf galaxies in the central 30 square degrees of the Fornax galaxy cluster.The NGFS uses near-UV and optical observations from the Dark Energy Camera mounted on the 4m Blanco Telescope in Chile. The survey is still underway, but in a recent publication led by Roberto P. Muoz (Institute of Astrophysics at the Pontifical Catholic University of Chile), the team has released an overview of the first results from only the central 3 square degrees of the NGFS field.Surprising DetectionGalaxy radii vs. their absolute i-band magnitudes, for the dwarfs found in NGFS as well as other stellar systems in the nearby universe. The NGFS dwarfs are similar to the ultra-diffuse dwarfs found in the Virgo and Coma clusters, but are several orders of magnitude fainter. [Muoz et al. 2015]In just this small central field, the team has found an astounding 284 low-surface-brightness dwarf galaxy candidates 158 of them previously undetected. At the bright end of this sample are dwarf galaxies that resemble the UDGs found in Virgo and Coma clusters, verifying that such objects exist in environments beyond only massive clusters.And at the faint end of the sample, the authors find additional extremely low-surface-brightness dwarfs that are several orders of magnitude fainter even than classical UDGs.The authors describe the properties of these galaxies and compare them to systems like classical UDGs and dwarf spheroidal galaxies in our own Local Cluster. The next step is to determine which of the differences between the sample of NGFS dwarfs and previously known systems are explained by the environmental factors of their host cluster, and which are simply due to sample biases.With much more data from the NGFS still to come, it seems likely that we will soon be able to examine an even larger sample of no-longer-missing dwarfs!CitationRoberto P. Muoz et al 2015 ApJ 813 L15. doi:10.1088/2041-8205/813/1/L15

[Arreflexic coma and MELAS syndrome].

PubMed

Muñoz-Guillén, N; León-López, R; Ferrer-Higueras, M J; Vargas-Vaserot, F J; Dueñas-Jurado, J M

2009-01-01

MELAS is a progressive neurodegenerative and fatal disease characterized by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes. It is the result of a mitochondrial DNA mutation. Although the incidence of MELAS is currently unknown, it is suspected that approximately 1 out of every 5,000 persons world-wide have some type of defect in mitochondrial DNA. Cardinal clinical features observed in more than 90% of the patients include severe headache that may be associated with stroke-like episodes, seizures and the onset of symptoms before the age of 40 years. Diagnosis is established through genetic test or by with muscle biopsies that reveal the presence of ragged-red fibers. Prognosis is poor, with death at an early age. In this article, we present the clinical case of a 31-year old women diagnosed of MELAS syndrome who was admitted to the Intensive Care Unit of our hospital with arreflexic coma.

Understanding Supermassive Black Hole Growth Mechanisms in the SSA22 Protocluster

NASA Astrophysics Data System (ADS)

Bonine, Brett; Lehmer, Bret

2018-01-01

The SSA22 protocluster is a collection of galaxies at redshift z = 3.09, corresponding to a look back time of 11.6 billion years. Observations of the protocluster allow for the investigation of galaxy properties of such protocluster environments in the early universe, potentially giving insight into the formation and evolution of galaxy clusters visible in the local universe (e.g., the Coma Cluster). Compared to other field galaxies at a similar redshift, a larger fraction of galaxies in SSA22 have been found to possess active galactic nuclei (AGN). This enhanced AGN activity suggests a relationship between the environment within the cluster and the growth of supermassive black holes (SMBHs). I will clarify the role that the protocluster environment at z = 3.09 plays in enhancing the growth of SMBHs in the cluster. To accomplish this, we are analyzing recently obtained WFC3 F160W data from the Hubble Space Telescope (HST) in SSA22, and equivalent archival CANDELS data in the Hubble Deep Field-North, to compare the merger rates and stellar mass distributions of galaxies in the SSA22 protocluster and in the field. Our goal is to assess the relative role that mergers play in enhancing the SMBH growth observed in over-dense regions in the z = 3 Universe.

Taking the Measure of the Universe: Precision Astrometry with SIM Planetquest (Preprint)

DTIC Science & Technology

2006-10-09

the orbits of nearby galaxies and groups going out to the distance of the Virgo Cluster . The orbits are in comoving coordinates. This is just a...single solution of a set of several solutions using present 3-d positions as inputs. The four massive objects ( Virgo Cluster , Coma Group, CenA Group, and... Virgo Cluster from a Numerical Action Method calculation with parameters M/L = 90 for spirals and 155 for ellipticals, Ωm = 0.24, ΩΛ = 0.76. The axes are

Challenges in the Management of a Patient with Myxoedema Coma in Ghana: A Case Report.

PubMed

Akpalu, Josephine; Atiase, Yacoba; Yorke, Ernest; Fiscian, Henrietta; Kootin-Sanwu, Cecilia; Akpalu, Albert

2017-03-01

Myxoedema coma is a rare life-threatening disease, and it is essential that it is managed appropriately to reduce the associated high mortality. However, in the setting where efficient healthcare delivery is hampered by inadequacies, the management of such cases may pose a significant challenge. We present the case of a middle-aged woman diagnosed with myxoedema coma and severe hyponatremia. The case report highlights some of the challenges that may be encountered during the management of myxoedema coma in similar settings and outlines the management strategies undertaken to overcome them in the absence of national guidelines. It also brings to the fore the need for clinicians to look out for clinical features suggestive of hypothyroidism particularly among high risk individuals for early diagnosis and treatment. None declared.

Resolved magnetic dynamo action in the simulated intracluster medium

NASA Astrophysics Data System (ADS)

Vazza, F.; Brunetti, G.; Brüggen, M.; Bonafede, A.

2018-02-01

Faraday rotation and synchrotron emission from extragalactic radio sources give evidence for the presence of magnetic fields extending over ˜ Mpc scales. However, the origin of these fields remains elusive. With new high-resolution grid simulations, we studied the growth of magnetic fields in a massive galaxy cluster that in several aspects is similar to the Coma cluster. We investigated models in which magnetic fields originate from primordial seed fields with comoving strengths of 0.1 nG at redshift z = 30. The simulations show evidence of significant magnetic field amplification. At the best spatial resolution (3.95 kpc), we are able to resolve the scale where magnetic tension balances the bending of magnetic lines by turbulence. This allows us to observe the final growth stage of the small-scale dynamo. To our knowledge, this is the first time that this is seen in cosmological simulations of the intracluster medium. Our mock observations of Faraday rotation provide a good match to observations of the Coma cluster. However, the distribution of magnetic fields shows strong departures from a simple Maxwellian distribution, suggesting that the three-dimensional structure of magnetic fields in real clusters may be significantly different than what is usually assumed when inferring magnetic field values from rotation measure observations.

Neutralinos and the Origin of Radio Halos in Clusters of Galaxies

NASA Astrophysics Data System (ADS)

Colafrancesco, S.; Mele, B.

2001-11-01

We assume that the supersymmetric lightest neutralino is a good candidate for the cold dark matter in the galaxy halo and explore the possibility to produce extended diffuse radio emission from high-energy electrons arising from the neutralino annihilation in galaxy clusters whose intracluster medium is filled with a large-scale magnetic field. We show that these electrons fit the population of seed relativistic electrons that is postulated in many models for the origin of cluster radio halos. For a uniform magnetic field of ~1-3 μG the population of seed relativistic electrons from neutralino annihilation can fit the radio halo spectra of two well-studied clusters: Coma and 1E 0657-56. In the case of a magnetic field that is radially decreasing from the cluster center, central values ~8 μG (for Coma) and ~50 μG (for 1E 0657-56) are required to fit the data. The radio halo data strongly favor a centrally peaked dark matter density profile (like a Navarro, Frenk, & White [NFW97] density profile). The shape and the frequency extension of the radio halo spectra are connected with the mass and physical composition of the neutralino. A pure gaugino neutralino with mass Mχ>=80 GeV can reasonably fit the radio halo spectra of both Coma and 1E 0657-56. The model we present here provides a number of extra predictions that make it definitely testable. On the one hand, it agrees quite well with the observations that (1) the radio halo is centered on the cluster dynamical center, usually coincident with the center of its X-ray emission; (2) the radio halo surface brightness is similar to the X-ray one; and (3) the monochromatic radio luminosity at 1.4 GHz correlates strongly with the intracluster (IC) gas temperature. On the other hand, the same model predicts that radio halos should be present in every cluster, which is not presently observed, although the predicted radio halo luminosities can change (decrease) by factors of up to ~102-106, depending on the amplitude and the structure of the IC magnetic field. In addition, neutral pions arising from neutralino annihilation should give rise to substantial amounts of diffuse gamma-ray emission, up to energies of order Mχ, that could be tested by the next-generation gamma-ray experiments.

Gas Dynamics and Kinetics in the Cometary Coma: Theory and Observations

NASA Technical Reports Server (NTRS)

Combi, Michael R.; Harris, Walter M.; Smyth, William H.

2005-01-01

Our ability to describe the physical state of the expanding coma affects fundamental areas of cometary study both directly and indirectly. In order to convert measured abundances of gas species in the coma to gas production rates, models for the distribution and kinematics of gas species in the coma are required. Conversely, many different types of observations, together with laboratory data and theory, are still required to determine coma model attributes and parameters. Accurate relative and absolute gas production rates and their variations with time and from comet to comet are crucial to our basic understanding of the composition and structure of cometary nuclei and their place in the solar system. We review the gas dynamics and kinetics of cometary comae from both theoretical and observational perspectives, which are important for understanding the wide variety of physical conditions that are encountered.

X-radiation from clusters of galaxies: Spectral evidence for a hot evolved gas

NASA Technical Reports Server (NTRS)

Serlemitsos, P. J.; Smith, B. W.; Boldt, E. A.; Holt, S. S.; Swank, J. H.

1976-01-01

OSO-8 observations of the X-ray flux in the range 2-60 keV from the Virgo, Perseus, and Coma Clusters provide strong evidence for the thermal origin of the radiation, including iron line emission. The data are adequately described by emission from an isothermal plasma with an iron abundance in near agreement with cosmic levels. A power law description is generally less acceptable and is ruled out in the case of Perseus. Implications on the origin of the cluster gas are discussed.

Evidence for Cluster Evolution from an Improved Measurement of the Velocity Dispersion and Morphological Fraction of Cluster 1324+3011 at z=0.76

NASA Astrophysics Data System (ADS)

Lubin, Lori M.; Oke, J. B.; Postman, Marc

2002-10-01

We have carried out additional spectroscopic observations in the field of cluster Cl 1324+3011 at z=0.76. Combined with the spectroscopy recently presented by Postman, Lubin, & Oke, we now have spectroscopically confirmed 47 cluster members. With this significant number of redshifts, we measure accurately the cluster velocity dispersion to be 1016+126-93 km s-1. The distribution of velocity offsets is consistent with a Gaussian, indicating no substantial velocity substructure. As previously noted for other optically selected clusters at redshifts of z>~0.5, a comparison between the X-ray luminosity (LX) and the velocity dispersion (σ) of Cl 1324+3011 implies that this cluster is underluminous in X-rays by a factor of ~3-40 when compared with the LX-σ relation for local and moderate-redshift clusters. We also examine the morphologies of those cluster members that have available high angular resolution imaging with the Hubble Space Telescope (HST). There are 22 spectroscopically confirmed cluster members within the HST field of view. Twelve of these are visually classified as early-type (elliptical or S0) galaxies, implying an early-type fraction of 0.55+0.17-0.14 in this cluster. This fraction is a factor of ~1.5 lower than that observed in nearby rich clusters. Confirming previous cluster studies, the results for cluster Cl 1324+3011, combined with morphological studies of other massive clusters at redshifts of 0<=z<~1, suggest that the galaxy population in massive clusters is strongly evolving with redshift. This evolution implies that early-type galaxies are forming out of the excess of late-type (spiral, irregular, and peculiar) galaxies over the ~7 Gyr timescale.

The specific entropy of elliptical galaxies: an explanation for profile-shape distance indicators?

NASA Astrophysics Data System (ADS)

Lima Neto, G. B.; Gerbal, D.; Márquez, I.

1999-10-01

Dynamical systems in equilibrium have a stationary entropy; we suggest that elliptical galaxies, as stellar systems in a stage of quasi-equilibrium, may have in principle a unique specific entropy. This uniqueness, a priori unknown, should be reflected in correlations between the fundamental parameters describing the mass (light) distribution in galaxies. Following recent photometrical work on elliptical galaxies by Caon et al., Graham & Colless and Prugniel & Simien, we use the Sérsic law to describe the light profile and an analytical approximation to its three-dimensional deprojection. The specific entropy is then calculated, supposing that the galaxy behaves as a spherical, isotropic, one-component system in hydrostatic equilibrium, obeying the ideal-gas equations of state. We predict a relation between the three parameters of the Sérsic law linked to the specific entropy, defining a surface in the parameter space, an `Entropic Plane', by analogy with the well-known Fundamental Plane. We have analysed elliptical galaxies in two rich clusters of galaxies (Coma and ABCG 85) and a group of galaxies (associated with NGC 4839, near Coma). We show that, for a given cluster, the galaxies follow closely a relation predicted by the constant specific entropy hypothesis with a typical dispersion (one standard deviation) of 9.5per cent around the mean value of the specific entropy. Moreover, assuming that the specific entropy is also the same for galaxies of different clusters, we are able to derive relative distances between Coma, ABGC 85, and the group of NGC 4839. If the errors are due only to the determination of the specific entropy (about 10per cent), then the error in the relative distance determination should be less than 20per cent for rich clusters. We suggest that the unique specific entropy may provide a physical explanation for the distance indicators based on the Sérsic profile put forward by Young & Currie and recently discussed by Binggeli & Jerjen.

The kinetics and dynamics of the coma of Halley's comet

NASA Technical Reports Server (NTRS)

Combi, Michael R.

1994-01-01

This grant to the University of Michigan supported the efforts of Michael R. Combi to serve as a co-investigator in collaboration with a larger effort by the principal investigator, William Smyth of Atmospheric and Environmental Research, Inc. The overall objective of this project was to analyze in a self-consistent manner unique optical O((sup 1)D) and NH2 ultra-high resolution line profile data of excellent quality and other supporting lower-resolution spectral data for the coma of comet P/Halley by using highly developed and physically-based cometary coma models in order to determine and explain in terms of physical processes the actual dynamics and photochemical kinetics that occur in the coma. The justification for this work is that it provides a valuable and underlying physical base from which to interpret significantly different types of coma observations in a self-consistent manner and hence bring into agreement (or avoid) apparent inconsistencies that arise from non-physically based interpretations. The level of effort for the Michigan component amounted to less than three person-months over a planned period of three years. The period had been extended at no extra cost to four years because the Michigan grant and the AER contract did not have coincident time periods. An effort of somewhat larger scope was undertaken by the PI. The importance of the O((sup 1)D) profiles is that they provide a direct trace of the water distribution in comets. The line profile shape is produced by the convolution of the outflow velocity and thermal dispersion of the parent water molecules with the photokinetic ejection of the oxygen atoms upon photodissociation of the parent water molecules. Our understanding of the NH2 and its precursor ammonia are important for comet-to-comet composition variations as they relate to the cosmo-chemistry of the early solar nebula. Modeling of the distribution of NH2 is necessary in order to infer the ammonia production rates from NH2 observations.

The Origin of Dwarf Early-Type Galaxies

NASA Astrophysics Data System (ADS)

Toloba, Elisa

2012-10-01

Abridge. We have conducted a spectrophotometric study of dwarf early-type galaxies (dEs) in the Virgo cluster and in regions of lower density. We have found that these galaxies show many properties in common with late-type galaxies but not with more massive early-types (E/S0). The properties of the dEs in Virgo show gradients within the cluster. dEs in the outer parts of the Virgo cluster are kinematically supported by rotation, while those in the center are supported by the random motions of their stars (i.e. pressure supported). The rotationally supported dEs have disky isophotes and faint underlying spiral/irregular substructures, they also show younger ages than those pressure supported, which have boxy isophotes and are smooth and regular, without any substructure. We compare the position of these dEs with massive early-type galaxies in the Faber-Jackson and Fundamental Plane relations, and we find that, although there is no difference between the position of rotationally and pressure supported dEs, both deviate from the relations of massive early-type galaxies in the direction of dwarf spheroidal systems (dSphs). We have used their offset with respect to the Fundamental Plane of E/S0 galaxies to estimate their dark matter fraction. All the properties studied in this work agree with a ram pressure stripping scenario, where late-type galaxies infall into the cluster, their interaction with the intergalactic medium blows away their gas and, as a result, they are quenched in a small amount of time. However, those dEs in the center of the cluster seem to have been fully transformed leaving no trace of their possible spiral origin, thus, if that is the case, they must have experienced a more violent mechanism in combination with ram pressure stripping.

Effect of a chameleon scalar field on the cosmic microwave background

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

Davis, Anne-Christine; Schelpe, Camilla A. O.; Shaw, Douglas J.

2009-09-15

We show that a direct coupling between a chameleonlike scalar field and photons can give rise to a modified Sunyaev-Zel'dovich (SZ) effect in the cosmic microwave background (CMB). The coupling induces a mixing between chameleon particles and the CMB photons when they pass through the magnetic field of a galaxy cluster. Both the intensity and the polarization of the radiation are modified. The degree of modification depends strongly on the properties of the galaxy cluster such as magnetic field strength and electron number density. Existing SZ measurements of the Coma cluster enable us to place constraints on the photon-chameleon coupling.more » The constrained conversion probability in the cluster is P{sub Coma}(204 GHz)<6.2x10{sup -5} at 95% confidence, corresponding to an upper bound on the coupling strength of g{sub eff}{sup (cell)}<2.2x10{sup -8} GeV{sup -1} or g{sub eff}{sup (Kolmo)}<(7.2-32.5)x10{sup -10} GeV{sup -1}, depending on the model that is assumed for the cluster magnetic field structure. We predict the radial profile of the chameleonic CMB intensity decrement. We find that the chameleon effect extends farther toward the edges of the cluster than the thermal SZ effect. Thus we might see a discrepancy between the x-ray emission data and the observed SZ intensity decrement. We further predict the expected change to the CMB polarization arising from the existence of a chameleonlike scalar field. These predictions could be verified or constrained by future CMB experiments.« less

Testing chameleon gravity with the Coma cluster

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

Terukina, Ayumu; Yamamoto, Kazuhiro; Lombriser, Lucas

2014-04-01

We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an attractive fifth force. The presence of an extra gravitational coupling, however, is tightly constrained by local measurements. In chameleon modifications of gravity, local tests can be evaded by employing a screening mechanism that suppresses the fifth force in dense environments. While the chameleon field may be screened in the interior of the cluster, its outer region can still be affected by the extramore » force, introducing a deviation between the hydrostatic and lensing mass of the cluster. Thus, the chameleon modification can be tested by combining the gas and lensing measurements of the cluster. We demonstrate the operability of our method with the Coma cluster, for which both a lensing measurement and gas observations from the X-ray surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect are available. Using the joint observational data set, we perform a Markov chain Monte Carlo analysis of the parameter space describing the different profiles in both the Newtonian and chameleon scenarios. We report competitive constraints on the chameleon field amplitude and its coupling strength to matter. In the case of f(R) gravity, corresponding to a specific choice of the coupling, we find an upper bound on the background field amplitude of |f{sub R0}| < 6 × 10{sup −5}, which is currently the tightest constraint on cosmological scales.« less

The hELENa project - I. Stellar populations of early-type galaxies linked with local environment and galaxy mass

NASA Astrophysics Data System (ADS)

Sybilska, A.; Lisker, T.; Kuntschner, H.; Vazdekis, A.; van de Ven, G.; Peletier, R.; Falcón-Barroso, J.; Vijayaraghavan, R.; Janz, J.

2017-09-01

We present the first in a series of papers in The role of Environment in shaping Low-mass Early-type Nearby galaxies (hELENa) project. In this paper, we combine our sample of 20 low-mass early types (dEs) with 258 massive early types (ETGs) from the ATLAS3D survey - all observed with the SAURON integral field unit - to investigate early-type galaxies' stellar population scaling relations and the dependence of the population properties on local environment, extended to the low-σ regime of dEs. The ages in our sample show more scatter at lower σ values, indicative of less massive galaxies being affected by the environment to a higher degree. The shape of the age-σ relations for cluster versus non-cluster galaxies suggests that cluster environment speeds up the placing of galaxies on the red sequence. While the scaling relations are tighter for cluster than for the field/group objects, we find no evidence for a difference in average population characteristics of the two samples. We investigate the properties of our sample in the Virgo cluster as a function of number density (rather than simple clustrocentric distance) and find that dE ages correlate with the local density such that galaxies in regions of lower density are younger, likely because they are later arrivals to the cluster or have experienced less pre-processing in groups, and consequently used up their gas reservoir more recently. Overall, dE properties correlate more strongly with density than those of massive ETGs, which was expected as less massive galaxies are more susceptible to external influences.

EEG as an Indicator of Cerebral Functioning in Postanoxic Coma.

PubMed

Juan, Elsa; Kaplan, Peter W; Oddo, Mauro; Rossetti, Andrea O

2015-12-01

Postanoxic coma after cardiac arrest is one of the most serious acute cerebral conditions and a frequent cause of admission to critical care units. Given substantial improvement of outcome over the recent years, a reliable and timely assessment of clinical evolution and prognosis is essential in this context, but may be challenging. In addition to the classic neurologic examination, EEG is increasingly emerging as an important tool to assess cerebral functions noninvasively. Although targeted temperature management and related sedation may delay clinical assessment, EEG provides accurate prognostic information in the early phase of coma. Here, the most frequently encountered EEG patterns in postanoxic coma are summarized and their relations with outcome prediction are discussed. This article also addresses the influence of targeted temperature management on brain signals and the implication of the evolution of EEG patterns over time. Finally, the article ends with a view of the future prospects for EEG in postanoxic management and prognostication.

Analysis of hydrogen Lyman-alpha observations of the coma of Comet P/Halley near the perihelion

NASA Technical Reports Server (NTRS)

Smyth, William H.; Marconi, M. L.; Combi, Michael R.

1995-01-01

The pioneer Venus Orbiter Ultraviolet Spectrometer measurements of the Lyman-alpha intensity of atomic hydrogen excited by solar resonance scattering in the coma of Comet P/Halley acquired from December 28, 1985, to January 6, 1986, and from January 31, 1986, to March 6, 1986, are simulated with the Monte Carlo Particle Trajectory Model corrected for optical depth effects. Spatially detailed comparisons between data and model show excellent agreement and are used to infer that the highest cometary activity may not be at perihelion, but about 2 1/2 weeks before. An improved set of H2O production rates is presented for the period of time that the spectrometer was observing and is found to be consistent with the rates from other types of measurements. The apparent discrepancy between Stewart (1987) in early March and International Ultraviolet Explorer OH derived rates is resolved. The problem with the conversion of 18-cm OH radio brightness to H2O production rates is also discussed.

The origin of dwarf early-type galaxies

NASA Astrophysics Data System (ADS)

Toloba, E.

2013-05-01

We have conducted a spectrophotometric study of dwarf early-type galaxies (dEs) in the Virgo cluster and in regions of lower density. We have found that these galaxies show many properties in common with late-type galaxies but not with more massive early-types (E/S0). The properties of the dEs in Virgo show gradients within the cluster. dEs in the outer parts of the Virgo cluster are kinematically supported by rotation, while those in the center are supported by the random motions of their stars (i.e. pressure supported). The rotationally supported dEs have disky isophotes and faint underlying spiral/irregular substructures, they also show younger ages than those pressure supported, which have boxy isophotes and are smooth and regular, without any substructure. We compare the position of these dEs with massive early-type galaxies in the Faber-Jackson and Fundamental Plane relations, and we find that, although there is no difference between the position of rotationally and pressure supported dEs, both deviate from the relations of massive early-type galaxies in the direction of dwarf spheroidal systems (dSphs). We have used their offset with respect to the Fundamental Plane of E/S0 galaxies to estimate their dark matter fraction. All the properties studied in this work agree with a ram pressure stripping scenario, where late-type galaxies infall into the cluster, their interaction with the intergalactic medium blows away their gas and, as a result, they are quenched in a small amount of time. However, those dEs in the center of the cluster seem to have been fully transformed leaving no trace of their possible spiral origin, thus, if that is the case, they must have experienced a more violent mechanism in combination with ram pressure stripping, the open problem is that even galaxy harassment does not fully explain the observed properties for the pressure supported dEs in the center of the Virgo cluster.

Relativistic protons in the Coma galaxy cluster: first gamma-ray constraints ever on turbulent reacceleration

NASA Astrophysics Data System (ADS)

Brunetti, G.; Zimmer, S.; Zandanel, F.

2017-12-01

The Fermi-LAT (Large Area Telescope) collaboration recently published deep upper limits to the gamma-ray emission of the Coma cluster, a cluster hosting the prototype of giant radio haloes. In this paper, we extend previous studies and use a formalism that combines particle reacceleration by turbulence and the generation of secondary particles in the intracluster medium to constrain relativistic protons and their role for the origin of the radio halo. We conclude that a pure hadronic origin of the halo is clearly disfavoured as it would require excessively large magnetic fields. However, secondary particles can still generate the observed radio emission if they are reaccelerated. For the first time the deep gamma-ray limits allow us to derive meaningful constraints if the halo is generated during phases of reacceleration of relativistic protons and their secondaries by cluster-scale turbulence. In this paper, we explore a relevant range of parameter space of reacceleration models of secondaries. Within this parameter space, a fraction of model configurations is already ruled out by current gamma-ray limits, including the cases that assume weak magnetic fields in the cluster core, B ≤ 2-3 μG. Interestingly, we also find that the flux predicted by a large fraction of model configurations assuming magnetic fields consistent with Faraday rotation measures (RMs) is not far from the limits. This suggests that a detection of gamma-rays from the cluster might be possible in the near future, provided that the electrons generating the radio halo are secondaries reaccelerated and the magnetic field in the cluster is consistent with that inferred from RM.

Prognostic value of EEG in different etiological types of coma.

PubMed

Khaburzania, M; Beridze, M

2013-06-01

Study aimed at evaluation of prognostic value of standard EEG in different etiology of coma and the influence of etiological factor on the EEG patterns and coma outcome. Totally 175 coma patients were investigated. Patients were evaluated by Glasgow Coma Scale (GCS), clinically and by 16 channel electroencephalography. Auditory evoked potentials studied by EEG -regime for evoked potentials in patients with vegetative state (VS). Patients divided in 8 groups according to coma etiology. All patients were studied for photoreaction, brainstem reflexes, localization of sound and pain, length of coma state and outcome. Brain injury visualized by conventional CT. Outcome defined as death, VS, recovery with disability and without disability. Disability was rated by Disability Rating Scale (DRS). Recovered patients assessed by Mini Mental State Examination (MMSE) scale. Statistics performed by SPSS-11.0. From 175 coma patients 55 patients died, 23 patients found in VS, 97 patients recovered with and without disability. In all etiological groups of coma the background EEG patterns were established. Correspondence analysis of all investigated factors revealed that sound localization had the significant association with EEG delta and theta rhythms and with recovery from coma state (Chi-sqr. =31.10493; p= 0.000001). Among 23 VS patients 9 patients had the signs of MCS and showed the long latency waves (p300) after binaural stimulation. The high amplitude theta frequencies in frontal and temporal lobes significantly correlated with prolongation of latency of cognitive evoked potentials (r=+0.47; p<0.01). Etiological factor had the significant effect on EEG patterns' association with coma outcome only in hemorrhagic and traumatic coma (chi-sqr.=12.95; p<0.005; chi-sqr.=7.92; p<0.03 respectively). Significant correlations established between the delta and theta EEG patterns and coma outcome. Low amplitude decreased power delta and theta frequencies correlated with SND in survived coma patients (r=+0.21; p<0.001; r=+0.27; p<0.001 respectively). Standard EEG is the useful tool for elucidation of coma patients with a high probability to recover as well as those patients, who are at high risk of SND in case of recovery from coma state.

Between My Body and My "Dead Body": Narratives of Coma.

PubMed

Meoded Danon, Limor

2016-01-01

This article is based on narrative research that focuses on corporeal experience during coma and during the rehabilitation process. Seventeen participants from different areas of Israel who had been in various kinds of coma states reveal what the corporeal experience of coma is. The participants are divided into three types of narrative protagonists--"dead-alive," "rational," and "emissaries." Each of the participants redefined the boundaries of the body, especially in cases when they spoke of experiences they did not understand as corporeal, for example, out-of-body experiences, near-death experiences, or experiences of being between the earthly and unearthly. Their struggle to find suitable words to tell their coma stories emphasizes these boundaries between experiencing and telling, which crossed the normative discursive border of the medical establishment and illustrates the ambiguous nature of human existence. © The Author(s) 2015.

The sensitivity of harassment to orbit: mass loss from early-type dwarfs in galaxy clusters

NASA Astrophysics Data System (ADS)

Smith, R.; Sánchez-Janssen, R.; Beasley, M. A.; Candlish, G. N.; Gibson, B. K.; Puzia, T. H.; Janz, J.; Knebe, A.; Aguerri, J. A. L.; Lisker, T.; Hensler, G.; Fellhauer, M.; Ferrarese, L.; Yi, S. K.

2015-12-01

We conduct a comprehensive numerical study of the orbital dependence of harassment on early-type dwarfs consisting of 168 different orbits within a realistic, Virgo-like cluster, varying in eccentricity and pericentre distance. We find harassment is only effective at stripping stars or truncating their stellar discs for orbits that enter deep into the cluster core. Comparing to the orbital distribution in cosmological simulations, we find that the majority of the orbits (more than three quarters) result in no stellar mass loss. We also study the effects on the radial profiles of the globular cluster systems of early-type dwarfs. We find these are significantly altered only if harassment is very strong. This suggests that perhaps most early-type dwarfs in clusters such as Virgo have not suffered any tidal stripping of stars or globular clusters due to harassment, as these components are safely embedded deep within their dark matter halo. We demonstrate that this result is actually consistent with an earlier study of harassment of dwarf galaxies, despite the apparent contradiction. Those few dwarf models that do suffer stellar stripping are found out to the virial radius of the cluster at redshift = 0, which mixes them in with less strongly harassed galaxies. However when placed on phase-space diagrams, strongly harassed galaxies are found offset to lower velocities compared to weakly harassed galaxies. This remains true in a cosmological simulation, even when haloes have a wide range of masses and concentrations. Thus phase-space diagrams may be a useful tool for determining the relative likelihood that galaxies have been strongly or weakly harassed.

Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies AO2, AO3 and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters AO3

NASA Technical Reports Server (NTRS)

White, Raymond E., III

1998-01-01

This final report uses ROSAT observations to analyze two different studies. These studies are: Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies; and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters.

Unexpected recovery of function after severe traumatic brain injury: the limits of early neuroimaging-based outcome prediction.

PubMed

Edlow, Brian L; Giacino, Joseph T; Hirschberg, Ronald E; Gerrard, Jason; Wu, Ona; Hochberg, Leigh R

2013-12-01

Prognostication in the early stage of traumatic coma is a common challenge in the neuro-intensive care unit. We report the unexpected recovery of functional milestones (i.e., consciousness, communication, and community reintegration) in a 19-year-old man who sustained a severe traumatic brain injury. The early magnetic resonance imaging (MRI) findings, at the time, suggested a poor prognosis. During the first year of the patient's recovery, MRI with diffusion tensor imaging and T2*-weighted imaging was performed on day 8 (coma), day 44 (minimally conscious state), day 198 (post-traumatic confusional state), and day 366 (community reintegration). Mean apparent diffusion coefficient (ADC) and fractional anisotropy values in the corpus callosum, cerebral hemispheric white matter, and thalamus were compared with clinical assessments using the Disability Rating Scale (DRS). Extensive diffusion restriction in the corpus callosum and bihemispheric white matter was observed on day 8, with ADC values in a range typically associated with neurotoxic injury (230-400 × 10(-6 )mm(2)/s). T2*-weighted MRI revealed widespread hemorrhagic axonal injury in the cerebral hemispheres, corpus callosum, and brainstem. Despite the presence of severe axonal injury on early MRI, the patient regained the ability to communicate and perform activities of daily living independently at 1 year post-injury (DRS = 8). MRI data should be interpreted with caution when prognosticating for patients in traumatic coma. Recovery of consciousness and community reintegration are possible even when extensive traumatic axonal injury is demonstrated by early MRI.

[Hyperammonemia type II as an example of urea cycle disorder].

PubMed

Hawrot-Kawecka, Anna M; Kawecki, Grzegorz P; Duława, Jan

2006-01-01

Ornithine transcarbamylase deficiency is the most common inherited urea cycle disorder. Its clinical manifestations as lethargy, vomites, coma and cerebral edema are the effect of the higher concentration of the ammonia in plasma. Hyperammonemia, caused by mutation in ornithine transcarbamylase gene, is often considered as a reason of coma by pediatricians but skipped by internist, although it is the third reason of hepatic coma in adults. This article is the recapitulation of published studies and their implication on everyday clinical practice.

MMN and novelty P3 in coma and other altered states of consciousness: a review.

PubMed

Morlet, Dominique; Fischer, Catherine

2014-07-01

In recent decades, there has been a growing interest in the assessment of patients in altered states of consciousness. There is a need for accurate and early prediction of awakening and recovery from coma. Neurophysiological assessment of coma was once restricted to brainstem auditory and primary cortex somatosensory evoked potentials elicited in the 30 ms range, which have both shown good predictive value for poor coma outcome only. In this paper, we review how passive auditory oddball paradigms including deviant and novel sounds have proved their efficiency in assessing brain function at a higher level, without requiring the patient's active involvement, thus providing an enhanced tool for the prediction of coma outcome. The presence of an MMN in response to deviant stimuli highlights preserved automatic sensory memory processes. Recorded during coma, MMN has shown high specificity as a predictor of recovery of consciousness. The presence of a novelty P3 in response to the subject's own first name presented as a novel (rare) stimulus has shown a good correlation with coma awakening. There is now a growing interest in the search for markers of consciousness, if there are any, in unresponsive patients (chronic vegetative or minimally conscious states). We discuss the different ERP patterns observed in these patients. The presence of novelty P3, including parietal components and possibly followed by a late parietal positivity, raises the possibility that some awareness processes are at work in these unresponsive patients.

MMN and Novelty P3 in Coma and Other Altered States of Consciousness: A Review

PubMed Central

Morlet, Dominique; Fischer, Catherine

2014-01-01

In recent decades, there has been a growing interest in the assessment of patients in altered states of consciousness. There is a need for accurate and early prediction of awakening and recovery from coma. Neurophysiological assessment of coma was once restricted to brainstem auditory and primary cortex somatosensory evoked potentials elicited in the thirty millisecond range, which have both shown good predictive value for poor coma outcome only. In this paper, we review how passive auditory oddball paradigms including deviant and novel sounds have proved their efficiency in assessing brain function at a higher level, without requiring the patient’s active involvement, thus providing an enhanced tool for the prediction of coma outcome. The presence of an MMN in response to deviant stimuli highlights preserved automatic sensory memory processes. Recorded during coma, MMN has shown high specificity as a predictor of recovery of consciousness. The presence of a novelty P3 in response to the subject’s own first name presented as a novel (rare) stimulus has shown a good correlation with coma awakening. There is now a growing interest in the search for markers of consciousness, if there are any, in unresponsive patients (chronic vegetative or minimally conscious states). We discuss the different ERP patterns observed in these patients. The presence of novelty P3, including parietal components and possibly followed by a late parietal positivity, raises the possibility that some awareness processes are at work in these unresponsive patients. PMID:24281786

Investigating Open Clusters Melotte 111 and NGC 6811

NASA Astrophysics Data System (ADS)

Gunshefski, Linda; Paust, Nathaniel E. Q.; van Belle, Gerard

2018-01-01

We present photometry and color-magnitude diagrams for the open clusters Melotte 111 (Coma Bernices) and NGC 6811. These clusters were observed with Lowell Observatory’s Discovery Channel Telescope Large Monolithic Imager in the V and I bands. The images were reduced with IRAF and photometry was performed with DAOPHOT/ALLSTAR. The resulting photometry extends many magnitudes below the main sequence turnoff. Both clusters are located nearby, (Melotte 111 d=86 pc and NGC 6811 d=1,107) and are evolutionarily young (Melotte 111, age=450 Myr and NGC 6811, age=1,000 Myr). This work marks the first step of a project to determine the cluster main sequence mass functions and examine how the mass functions evolve in young stellar populations.

STANDARD STARS AND EMPIRICAL CALIBRATIONS FOR Hα AND Hβ PHOTOMETRY

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

Joner, Michael D.; Hintz, Eric G., E-mail: joner@byu.edu, E-mail: hintz@byu.edu

2015-12-15

We define an Hα photometric system that is designed as a companion to the well established Hβ index. The new system is built on spectrophotometric observations of field stars as well as stars in benchmark open clusters. We present data for 75 field stars, 12 stars from the Coma star cluster, 24 stars from the Hyades, 17 stars from the Pleiades, and 8 stars from NGC 752 to be used as primary standard stars in the new systems. We show that the system transformations are relatively insensitive to the shape of the filter functions. We make comparisons of the Hαmore » index to the Hβ index and illustrate the relationship between the two systems. In addition, we present relations that relate both hydrogen indices to equivalent width and effective temperature. We derive equations to calibrate both systems for Main Sequence stars with spectral types in the range O9 to K2 for equivalent width and A2 to K2 for effective temperature.« less

Nature of multiple-nucleus cluster galaxies

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

Merritt, D.

1984-05-01

In models for the evolution of galaxy clusters which include dynamical friction with the dark binding matter, the distribution of galaxies becomes more concentrated to the cluster center with time. In a cluster like Coma, this evolution could increase by a factor of approximately 3 the probability of finding a galaxy very close to the cluster center, without decreasing the typical velocity of such a galaxy significantly below the cluster mean. Such an enhancement is roughly what is needed to explain the large number of first-ranked cluster galaxies which are observed to have extra ''nuclei''; it is also consistent withmore » the high velocities typically measured for these ''nuclei.'' Unlike the cannibalism model, this model predicts that the majority of multiple-nucleus systems are transient phenomena, and not galaxies in the process of merging.« less

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

NASA Technical Reports Server (NTRS)

Jernigan, Garrett

1998-01-01

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

Fluorine Abundances of AGB Stars in Stellar Clusters

NASA Astrophysics Data System (ADS)

Hren, A.; Lebzelter, T.; Aringer, B.; Hinkle, K. H.; Nowotny, W.

2015-08-01

We have measured the abundance of fluorine, [F/Fe], in a number of AGB stars in stellar clusters have correlated the results with their C/O ratios. This allows us to investigate the change in the fluorine abundance along the evolution on the giant branch. The target list includes primarily O-rich stars in three LMC globular clusters - NGC 1806, NGC 1846 and NGC 1978 - as well as Rup 106 and 47 Tuc in our Galaxy. The observational data were obtained with the PHOENIX spectrograph, and the COMA code was used for modelling the synthetic spectra. Within individual clusters, we find consistent [F/Fe] values at similar C/O for most of our target stars.

Discovery of a young asteroid cluster associated with P/2012 F5 (Gibbs)

NASA Astrophysics Data System (ADS)

Novaković, Bojan; Hsieh, Henry H.; Cellino, Alberto; Micheli, Marco; Pedani, Marco

2014-03-01

We present the results of our search for a dynamical family around the active Asteroid P/2012 F5 (Gibbs). By applying the hierarchical clustering method, we discover an extremely compact 9-body cluster associated with P/2012 F5. The statistical significance of this newly discovered Gibbs cluster is estimated to be >99.9%, strongly suggesting that its members share a common origin. The cluster is located in a dynamically cold region of the outer main-belt at a proper semi-major axis of ∼3.005 AU, and all members are found to be dynamically stable over very long timescales. Backward numerical orbital integrations show that the age of the cluster is only 1.5 ± 0.1 Myr. Taxonomic classifications are unavailable for most of the cluster members, but SDSS spectrophotometry available for two cluster members indicate that both appear to be Q-type objects. We also estimate a lower limit of the size of the parent body to be about 10 km, and find that the impact event which produced the Gibbs cluster is intermediate between a cratering and a catastrophic collision. In addition, we search for new main-belt comets in the region of the Gibbs cluster by observing seven asteroids either belonging to the cluster, or being very close in the space of orbital proper elements. However, we do not detect any convincing evidence of the presence of a tail or coma in any our targets. Finally, we obtain optical images of P/2012 F5, and find absolute R-band and V-band magnitudes of HR = 17.0 ± 0.1 mag and HV = 17.4 ± 0.1 mag, respectively, corresponding to an upper limit on the diameter of the P/2012 F5 nucleus of ∼2 km.

Active music therapy in the rehabilitation of severe brain injured patients during coma recovery.

PubMed

Formisano, R; Vinicola, V; Penta, F; Matteis, M; Brunelli, S; Weckel, J W

2001-01-01

Active improvised music therapy may offer an adjuvant from of treatment in the early rehabilitation of severe brain-injured patients. Active music therapy consists of musical improvisation between patient and therapist by singing or by playing different musical instruments, according to the vital functions, the neurological conditions and the motor abilities of the patients. We studied 34 severe brain-injured patients with a mean coma duration of 52 days +/- 37.21 and a mean interval from coma onset to the beginning of rehabilitation of 154 days on average. Our preliminary results show a significant improvement of the collaboration of the severe brain-injured patients and a reduction of undesired behaviours such as inertia (reduced psychomotor initiative) or psychomotor agitation.

Amiodarone induced myxedema coma: Two case reports and literature review.

PubMed

Hawatmeh, Amer; Thawabi, Mohammad; Abuarqoub, Ahmad; Shamoon, Fayez

2018-05-21

Amiodarone is a benzofuran derivative that contains 37% iodine by weight and is structurally similar to the thyroid hormones. Amiodarone has a complex effect on the thyroid gland, ranging from abnormalities of thyroid function tests to overt thyroid dysfunction, with either thyrotoxicosis or hypothyroidism. Myxedema coma secondary to amiodarone use has been rarely reported in the literature. Our two case reports are an add on to the literature, and illustrate that amiodarone is an important cause of thyroid dysfunction including hypothyroidism and myxedema coma. Hence, healthcare providers should have a high index of suspicion for these conditions while treating patients who are taking amiodarone therapy as early recognition and management are essential to optimize outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

XMM-Newton observation of the Coma Galaxy cluster. The temperature structure in the central region

NASA Astrophysics Data System (ADS)

Arnaud, M.; Aghanim, N.; Gastaud, R.; Neumann, D. M.; Lumb, D.; Briel, U.; Altieri, B.; Ghizzardi, S.; Mittaz, J.; Sasseen, T. P.; Vestrand, W. T.

2001-01-01

We present a temperature map and a temperature profile of the central part (r < 20' or 1/4 virial radius) of the Coma cluster. We combined 5 overlapping pointings made with XMM/EPIC/MOS and extracted spectra in boxes of 3.5'x3.5'. The temperature distribution around the two central galaxies is remarkably homogeneous (r<10'), contrary to previous ASCA results, suggesting that the core is actually in a relaxed state. At larger distance from the cluster center we do see evidence for recent matter accretion. We confirm the cool area in the direction of NGC 4921, probably due to gas stripped from an infalling group. We find indications of a hot front in the South West, in the direction of NGC 4839, probably due to an adiabatic compression. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA). EPIC was developed by the EPIC Consortium led by the Principal Investigator, Dr. M. J. L. Turner. The consortium comprises the following Institutes: University of Leicester, University of Birmingham, (UK); CEA/Saclay, IAS Orsay, CESR Toulouse, (France); IAAP Tuebingen, MPE Garching, (Germany); IFC Milan, ITESRE Bologna, IAUP Palermo, Italy. EPIC is funded by: PPARC, CEA, CNES, DLR and ASI.

Enviromental Effects on Internal Color Gradients of Early-Type Galaxies

NASA Astrophysics Data System (ADS)

La Barbera, F.; de Carvalho, R. R.; Gal, R. R.; Busarello, G.; Haines, C. P.; Mercurio, A.; Merluzzi, P.; Capaccioli, M.; Djorgovski, S. G.

2007-05-01

One of the most debated issues of observational and theoretical cosmology is that of how the environment affects the formation and evolution of galaxies. To gain new insight into this subject, we have derived surface photometry for a sample of 3,000 early-type galaxies belonging to 163 clusters with different richness, spanning a redshift range of 0.05 to 0.25. This large data-set is used to analyze how the color distribution inside galaxies depends on several parameters, such as cluster richness, local galaxy density, galaxy luminosity and redshift. We find that the internal color profile of galaxies strongly depends on the environment where galaxies reside. Galaxies in poor and rich clusters are found to follow two distinct trends in the color gradient vs. redshift diagram, with color gradients beeing less steep in rich rather than in poor clusters. No dependence of color gradients on galaxy luminosity is detected both for poor and rich clusters. We find that color gradients strongly depend on local galaxy density, with more shallow gradients in high density regions. Interestingly, this result holds only for low richness clusters, with color gradients of galaxies in rich clusters showing no dependence on local galaxy density. Our results support a reasonable picture whereby young early-type galaxies form in a dissipative collapse process, and then undergo increased (either major or minor) merging activity in richer rather than in poor clusters.

CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

PubMed

Pallesen, Lars P; Khomenko, Andrei; Dzialowski, Imanuel; Barlinn, Jessica; Barlinn, Kristian; Zerna, Charlotte; van der Hoeven, Erik Jrj; Algra, Ale; Kapelle, L Jaap; Michel, Patrik; Bodechtel, Ulf; Demchuk, Andrew M; Schonewille, Wouter; Puetz, Volker

2017-02-01

Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. <8) and Pons-Midbrain Index (<3 vs. ≥3) with mortality and favourable outcome (modified Rankin Scale score 0-3) at one month. Results Of 619 patients in the Basilar Artery International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

[Myxedema coma in a patient with type 1 neurofibromatosis: rare association].

PubMed

Sasazawa, Denise Tieko; Tsukumo, Daniela Miti; Lalli, Cristina Alba

2013-12-01

Myxedema coma, a rare but fatal emergency, is an extreme expression of hypothyroidism. We describe a 51-year-old male patient who has discontinued hypothyroidism treatment 10 months earlier and developed lethargy, edema, and cold intolerance symptoms. He also had a previous diagnosis of neurofibromatosis. After admission, he progressed to respiratory insufficiency and coma. The prompt recognition of the condition, thyroid hormone replacement, and management of the complications (hypoventilation, cardiogenic shock associated with swinging heart, adrenal and renal insufficiency and sepsis), resulted in a favorable evolution.

Subaru Weak-lensing Survey of Dark Matter Subhalos in the Coma Cluster: Subhalo Mass Function and Statistical Properties

NASA Astrophysics Data System (ADS)

Okabe, Nobuhiro; Futamase, Toshifumi; Kajisawa, Masaru; Kuroshima, Risa

2014-04-01

We present a 4 deg2 weak gravitational lensing survey of subhalos in the very nearby Coma cluster using the Subaru/Suprime-Cam. The large apparent size of cluster subhalos allows us to measure the mass of 32 subhalos detected in a model-independent manner, down to the order of 10-3 of the virial mass of the cluster. Weak-lensing mass measurements of these shear-selected subhalos enable us to investigate subhalo properties and the correlation between subhalo masses and galaxy luminosities for the first time. The mean distortion profiles stacked over subhalos show a sharply truncated feature which is well-fitted by a Navarro-Frenk-White (NFW) mass model with the truncation radius, as expected due to tidal destruction by the main cluster. We also found that subhalo masses, truncation radii, and mass-to-light ratios decrease toward the cluster center. The subhalo mass function, dn/dln M sub, in the range of 2 orders of magnitude in mass, is well described by a single power law or a Schechter function. Best-fit power indices of 1.09^{+0.42}_{-0.32} for the former model and 0.99_{-0.23}^{+0.34} for the latter, are in remarkable agreement with slopes of ~0.9-1.0 predicted by the cold dark matter paradigm. The tangential distortion signals in the radial range of 0.02-2 h -1 Mpc from the cluster center show a complex structure which is well described by a composition of three mass components of subhalos, the NFW mass distribution as a smooth component of the main cluster, and a lensing model from a large scale structure behind the cluster. Although the lensing signals are 1 order of magnitude lower than those for clusters at z ~ 0.2, the total signal-to-noise ratio, S/N = 13.3, is comparable, or higher, because the enormous number of background source galaxies compensates for the low lensing efficiency of the nearby cluster. Based on data collected from the Subaru Telescope and obtained from SMOKA, operated by the Astronomy Data Center, National Astronomical Observatory of Japan.

Far-Infrared Emission of Intracluster Dust (ICD)

NASA Astrophysics Data System (ADS)

Arimoto, N.; Takagi, T.; Hanami, H.

2000-12-01

In the young universe, clusters of galaxies could be bright FIR-Submm sources due to the dust emissions from young ellipticals. The intracluster dust (ICD) could also contribute to the FIR-Submm emissions considerably, but the ICD is fragile in the ambient hot ICM. Therefore, a chance to detect the ICD emission would be much smaller than the dust emissions from galaxies. Dust emissions from elliptical galaxies (EROs) in the young Coma cluster at a distance of z=2-3 would be easily detected by a future mission of H2L2 satellite, thus the FIR-Submm survey would become a powerful tool for searching high-z clusters.

The Evolution of Globular Cluster Systems In Early-Type Galaxies

NASA Astrophysics Data System (ADS)

Grillmair, Carl

1999-07-01

We will measure structural parameters {core radii and concentrations} of globular clusters in three early-type galaxies using deep, four-point dithered observations. We have chosen globular cluster systems which have young, medium-age and old cluster populations, as indicated by cluster colors and luminosities. Our primary goal is to test the hypothesis that globular cluster luminosity functions evolve towards a ``universal'' form. Previous observations have shown that young cluster systems have exponential luminosity functions rather than the characteristic log-normal luminosity function of old cluster systems. We will test to see whether such young system exhibits a wider range of structural parameters than an old systems, and whether and at what rate plausible disruption mechanisms will cause the luminosity function to evolve towards a log-normal form. A simple observational comparison of structural parameters between different age cluster populations and between diff er ent sub-populations within the same galaxy will also provide clues concerning both the formation and destruction mechanisms of star clusters, the distinction between open and globular clusters, and the advisability of using globular cluster luminosity functions as distance indicators.

Multiple populations within globular clusters in Early-type galaxies Exploring their effect on stellar initial mass function estimates

NASA Astrophysics Data System (ADS)

Chantereau, W.; Usher, C.; Bastian, N.

2018-05-01

It is now well-established that most (if not all) ancient globular clusters host multiple populations, that are characterised by distinct chemical features such as helium abundance variations along with N-C and Na-O anti-correlations, at fixed [Fe/H]. These very distinct chemical features are similar to what is found in the centres of the massive early-type galaxies and may influence measurements of the global properties of the galaxies. Additionally, recent results have suggested that M/L variations found in the centres of massive early-type galaxies might be due to a bottom-heavy stellar initial mass function. We present an analysis of the effects of globular cluster-like multiple populations on the integrated properties of early-type galaxies. In particular, we focus on spectral features in the integrated optical spectrum and the global mass-to-light ratio that have been used to infer variations in the stellar initial mass function. To achieve this we develop appropriate stellar population synthesis models and take into account, for the first time, an initial-final mass relation which takes into consideration a varying He abundance. We conclude that while the multiple populations may be present in massive early-type galaxies, they are likely not responsible for the observed variations in the mass-to-light ratio and IMF sensitive line strengths. Finally, we estimate the fraction of stars with multiple populations chemistry that come from disrupted globular clusters within massive ellipticals and find that they may explain some of the observed chemical patterns in the centres of these galaxies.

Snapshot Survey of the Globular Cluster Populations of Isolated Early Type Galaxies

NASA Astrophysics Data System (ADS)

Gregg, Michael

2017-08-01

We propose WFC3/UVIS snapshot observations of a sample of 75 isolated early type galaxiesresiding in cosmic voids or extremely low density regions. The primary aim is to usetheir globular cluster populations to reconstruct their evolutionary history, revealingif, how, and why void ellipticals differ from cluster ellipticals. The galaxies span arange of luminosities, providing a varied sample for comparison with the well-documentedglobular cluster populations in denser environments. This proposed WFC3 study of isolatedearly type galaxies breaks new ground by targeting a sample which has thus far receivedlittle attention, and, significantly, this will be the first such study with HST.Characterizing early type galaxies in voids and their GC systems promises to increase ourunderstanding of galaxy formation and evolution of galaxies in general because isolatedobjects are the best approximation to a control sample that we have for understanding theinfluence of environment on formation and evolution. Whether these isolated objects turnout to be identical to or distinct from counterparts in other regions of the Universe,they will supply insight into the formation and evolution of all galaxies. Parallel ACSimaging will help to characterize the near field environments of the sample.

Rapidly rotating single late-type giants: New FK Comae stars?

NASA Technical Reports Server (NTRS)

Fekel, Francis C.

1986-01-01

A group of rapidly rotating single late-type giants was found from surveys of chromospherically active stars. These stars have V sin I's ranging from 6 to 46 km/sec, modest ultraviolet emission line fluxes, and strong H alpha absorption lines. Although certainly chromospherically active, their characteristics are much less extreme than those of FK Com and one or two other similar systems. One possible explanation for the newly identified systems is that they have evolved from stars similar to FK Com. The chromospheric activity and rotation of single giant stars like FK Com would be expected to decrease with time as they do in single dwarfs. Alternatively, this newly identified group may have evolved from single rapidly rotating A, or early F stars.

Cosmic Ray Streaming in Galaxy Clusters

NASA Astrophysics Data System (ADS)

Wiener, Joshua; Gould Zweibel, Ellen; Oh, Siang P.

2017-08-01

The origin of diffuse radio emission in galaxy clusters remains an open question in astrophysics. This emission indicates the presence of cluster-wide magnetic fields and high energy cosmic ray (CR) electrons. I will discuss how the properties of the observed radio emission in clusters are shaped by different CR transport processes, namely CR streaming. Recent work has shown that fast streaming may turn off radio emission on relatively short time scales - a full treatment of magnetohydrodynamic (MHD) wave damping shows that streaming may be even faster than previously thought in high β environments. I will briefly introduce the physics behind CR transport, and present simple numerical simulations of the Coma cluster that predict radio emission, as well as other observable signatures such as gamma radiation that can differentiate between models for the source of the CR electrons.

Nature vs. nurture in the low-density environment: structure and evolution of early-type dwarf galaxies in poor groups

NASA Astrophysics Data System (ADS)

Annibali, F.; Grützbauch, R.; Rampazzo, R.; Bressan, A.; Zeilinger, W. W.

2011-04-01

We present the stellar population properties of 13 dwarf galaxies residing in poor groups (low-density environment, LDE) observed with VIMOS at VLT. Ages, metallicities, and [α/Fe] ratios were derived within an r < re/2 aperture from the Lick indices Hβ, Mgb, Fe5270, and Fe5335 through comparison with our simple stellar population (SSP) models that account for variable [α/Fe] ratios. For a fiducial subsample of 10 early-type dwarfs, we derived median values and scatters around the medians of 5.7 ± 4.4 Gyr, -0.26 ± 0.28, and -0.04 ± 0.33 for age, log Z/Z⊙, and [α/Fe] , respectively. For a selection of bright early-type galaxies (ETGs) from an earlier sample residing in a comparable environment, we derive median values of 9.8 ± 4.1 Gyr, 0.06 ± 0.16, and 0.18 ± 0.13 for the same stellar population parameters. It follows that dwarfs are on average younger, less metal rich, and less enhanced in the α-elements than giants, in agreement with the extrapolation to the low-mass regime of the scaling relations derived for giant ETGs. From the total (dwarf + giant) sample, we find that age ∝ σ0.39 ± 0.22, Z ∝ σ0.80 ± 0.16, and α/Fe ∝ σ0.42 ± 0.22. We also find correlations with morphology, in the sense that the metallicity and the [α/Fe] ratio increase with the Sersic index n or with the bulge-to-total light fraction B/T. The presence of a strong morphology-[α/Fe] relation appears to contradict the possible evolution along the Hubble sequence from low B/T (low n) to high B/T (high n) galaxies. We also investigate the role played by environment by comparing the properties of our LDE dwarfs with those of Coma red passive dwarfs from the literature. We find possible evidence that LDE dwarfs experienced more prolonged star formations than Coma dwarfs, however larger data samples are needed to draw firmer conclusions. Based on observations obtained at the European Southern Observatory, La Silla, Chile.

The ESO Nearby Abell Cluster Survey. VI. Spatial distribution and kinematics of early- and late-type galaxies

NASA Astrophysics Data System (ADS)

de Theije, P. A. M.; Katgert, P.

1999-01-01

Analysis of the data obtained in the ESO Nearby Abell Cluster Survey (ENACS) has shown that the space distribution and kinematics of galaxies with detectable emission lines in their spectra differ significantly from those of galaxies without emission lines. This result, and details of the kinematics, were considered as support for the idea that at least the spirals with emission lines are on orbits that are not isotropic. This might indicate that this subset of late-type galaxies either has `first approach'-orbits towards the dense core of their respective clusters, or has orbits that `avoid' the core. The galaxies with emission lines are essentially all late-type galaxies. On the other hand, the emission-line galaxies represent only about a third of the late-type galaxies, the majority of which do not show detectable emission lines. The galaxies without emission lines are therefore a mix of early- and late-type galaxies. In this paper we attempt to separate early- and late-type galaxies, and we study possible differences in distribution and kinematics of the two galaxy classes. For only about 10% of the galaxies in the ENACS, the morphology is known from imaging. Here, we describe our classification on the basis of the ENACS spectrum. The significant information in each spectrum is compressed into 15 Principal Components, which are used as input for an Artificial Neural Network. The latter is `trained' with 150 of the 270 galaxies for which a morphological type is available from Dressler, and subsequently used to classify each galaxy. This yields a classification for two-thirds of the ENACS galaxies. The Artificial Neural Network has two output classes: early-type (E+S0) and late-type (S+I) galaxies. We do not distinguish E and S0 galaxies, because these cannot be separated very robustly on the basis of the spectrum. The success rate of the classification is estimated from the sample of 120 galaxies with Dressler morphologies which were not used to train the ANN. The success rate is higher for early-type than for late-type galaxies (78+/-6% vs. {63+/-6%}). The weighted average success rate, irrespective of type, is {73+/-4%}. The success rate is somewhat larger for the training set, and highest for the galaxies with emission lines. Of the 3798 galaxies that were classified from their spectrum {57+/-7%} are of early type, and {43+/-7%} of late type. Using a subset of these 3798 galaxies, we constructed a composite cluster of 2594 galaxies, 399 of which have emission lines and are therefore almost exclusively spirals and irregulars. The kinematics and spatial distribution of the late-type galaxies without emission lines resemble much more those of the early-type galaxies than those of the late-type galaxies with emission lines. Yet, the late-type galaxies without emission lines may have a somewhat larger velocity dispersion and a slightly less centrally concentrated distribution than the early-type galaxies. Only the late-type galaxies with emission lines appear to have a considerably larger global velocity dispersion and a much less concentrated projected density profile than the other galaxies. Thus, the suggestion of fairly radial, and possibly `first approach' orbits applies only to spirals with emission lines. The early-type galaxies with emission lines (among which the AGN), may also have a large velocity dispersion and be concentrated towards the cluster centre. Based on observations collected at the European Southern Observatory (La Silla, Chile)

GalWeight: A New and Effective Weighting Technique for Determining Galaxy Cluster and Group Membership

NASA Astrophysics Data System (ADS)

Abdullah, Mohamed H.; Wilson, Gillian; Klypin, Anatoly

2018-07-01

We introduce GalWeight, a new technique for assigning galaxy cluster membership. This technique is specifically designed to simultaneously maximize the number of bona fide cluster members while minimizing the number of contaminating interlopers. The GalWeight technique can be applied to both massive galaxy clusters and poor galaxy groups. Moreover, it is effective in identifying members in both the virial and infall regions with high efficiency. We apply the GalWeight technique to MDPL2 and Bolshoi N-body simulations, and find that it is >98% accurate in correctly assigning cluster membership. We show that GalWeight compares very favorably against four well-known existing cluster membership techniques (shifting gapper, den Hartog, caustic, SIM). We also apply the GalWeight technique to a sample of 12 Abell clusters (including the Coma cluster) using observations from the Sloan Digital Sky Survey. We conclude by discussing GalWeight’s potential for other astrophysical applications.

Far-infrared properties of cluster galaxies

NASA Technical Reports Server (NTRS)

Bicay, M. D.; Giovanelli, R.

1987-01-01

Far-infrared properties are derived for a sample of over 200 galaxies in seven clusters: A262, Cancer, A1367, A1656 (Coma), A2147, A2151 (Hercules), and Pegasus. The IR-selected sample consists almost entirely of IR normal galaxies, with Log of L(FIR) = 9.79 solar luminosities, Log of L(FIR)/L(B) = 0,79, and Log of S(100 microns)/S(60 microns) = 0.42. None of the sample galaxies has Log of L(FIR) greater than 11.0 solar luminosities, and only one has a FIR-to-blue luminosity ratio greater than 10. No significant differences are found in the FIR properties of HI-deficient and HI-normal cluster galaxies.

The Ellipticities of Cluster Early-type Galaxies from z ~ 1 to z ~ 0: No Evolution in the Overall Distribution of Bulge-to-Disk Ratios

NASA Astrophysics Data System (ADS)

Holden, B. P.; Franx, M.; Illingworth, G. D.; Postman, M.; van der Wel, A.; Kelson, D. D.; Blakeslee, J. P.; Ford, H.; Demarco, R.; Mei, S.

2009-03-01

We have compiled a sample of early-type cluster galaxies from 0 < z < 1.3 and measured the evolution of their ellipticity distributions. Our sample contains 487 galaxies in 17 z>0.3 clusters with high-quality space-based imaging and a comparable sample of 210 galaxies in 10 clusters at z < 0.05. We select early-type galaxies (elliptical and S0 galaxies) that fall within the cluster R 200, and which lie on the red-sequence in the magnitude range -19.3>MB > - 21, after correcting for luminosity evolution as measured by the fundamental plane. Our ellipticity measurements are made in a consistent manner over our whole sample. We perform extensive simulations to quantify the systematic and statistical errors, and find that it is crucial to use point-spread function (PSF)-corrected model fits; determinations of the ellipticity from Hubble Space Telescope image data that do not account for the PSF "blurring" are systematically and significantly biased to rounder ellipticities at redshifts z>0.3. We find that neither the median ellipticity, nor the shape of the ellipticity distribution of cluster early-type galaxies evolves with redshift from z ~ 0 to z>1 (i.e., over the last ~8 Gyr). The median ellipticity at z>0.3 is statistically identical with that at z < 0.05, being higher by only 0.01 ± 0.02 or 3 ± 6%, while the distribution of ellipticities at z>0.3 agrees with the shape of the z < 0.05 distribution at the 1-2% level (i.e., the probability that they are drawn from the same distribution is 98-99%). These results are strongly suggestive of an unchanging overall bulge-to-disk ratio distribution for cluster early-type galaxies over the last ~8 Gyr from z ~ 1 to z ~ 0. This result contrasts with that from visual classifications which show that the fraction of morphologically-selected disk-dominated early-type galaxies, or S0s, is significantly lower at z>0.4 than at z ~ 0. We find that the median disk-dominated early-type, or S0, galaxy has a somewhat higher ellipticity at z>0.3, suggesting that rounder S0s are being assigned as ellipticals. Taking the ellipticity measurements and assuming, as in all previous studies, that the intrinsic ellipticity distribution of both elliptical and S0 galaxies remains constant, then we conclude from the lack of evolution in the observed early-type ellipticity distribution that the relative fractions of ellipticals and S0s do not evolve from z ~ 1 to z = 0 for a red-sequence selected samples of galaxies in the cores of clusters of galaxies. Based on observations 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 No. NAS5-26555. 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. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

[Phylogenetic analysis of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg)].

PubMed

Yu, Xue; Yu, Hong; Kong, Lingfeng; Li, Qi

2014-02-01

The deduced amino acid sequence characteristics, classification and phylogeny of tyrosinase gene family in the Pacific oyster (Crassostrea gigas Thunberg) were analyzed using bioinformatics methods. The results showed that gene duplication was the major cause of tyrosinase gene expansion in the Pacific oyster. The tyrosinase gene family in the Pacific oyster can be further classified into three types: secreted form (Type A), cytosolic form (Type B) and membrane-bound form (Type C). Based on the topology of the phylogenetic tree of the Pacific oyster tyrosinases, among Type A isoforms, tyr18 seemed divergent from other Type A tyrosinases early, while tyr2 and tyr9 appeared divergent early in Type B. In Type C tyrosinses, tyr8 was divergent early. The cluster of the Pacific oyster tyrosinasesis determined by their classifications and positions in the scaffolds. Further analysis suggested that Type A tyrosinases of C. gigas clustered with those from cephalopods and then with nematodes and cnidarians. Type B tyrosinases were generally clustered with the same type of tyrosinases from molluscas and nematodes, and then with those from platyhelminths, cnidarians and chordates. Type A tyrosinases in the Pacific oyster and the Pearl oyster expanded independently and were divergent from membrane-bound form of tyrosinases in chordata, platyhelminthes and annelida. These observations suggested that Type C tyrosinases in the bivalve had a distinct evolution direction.

Clinical characteristics and outcomes of myxedema coma: Analysis of a national inpatient database in Japan.

PubMed

Ono, Yosuke; Ono, Sachiko; Yasunaga, Hideo; Matsui, Hiroki; Fushimi, Kiyohide; Tanaka, Yuji

2017-03-01

Myxedema coma is a life-threatening and emergency presentation of hypothyroidism. However, the clinical features and outcomes of this condition have been poorly defined because of its rarity. We conducted a retrospective observational study of patients diagnosed with myxedema coma from July 2010 through March 2013 using a national inpatient database in Japan. We investigated characteristics, comorbidities, treatments, and in-hospital mortality of patients with myxedema coma. We identified 149 patients diagnosed with myxedema coma out of approximately 19 million inpatients in the database. The mean (standard deviation) age was 77 (12) years, and two-thirds of the patients were female. The overall proportion of in-hospital mortality among cases was 29.5%. The number of patients was highest in the winter season. Patients treated with steroids, catecholamines, or mechanical ventilation showed higher in-hospital mortality than those without. Variations in type and dosage of thyroid hormone replacement were not associated with in-hospital mortality. The most common comorbidity was cardiovascular diseases (40.3%). The estimated incidence of myxedema coma was 1.08 per million people per year in Japan. Multivariable logistic regression analysis revealed that higher age and use of catecholamines (with or without steroids) were significantly associated with higher in-hospital mortality. The present study identified the clinical characteristics and outcomes of patients with myxedema coma using a large-scale database. Myxedema coma mortality was independently associated with age and severe conditions requiring treatment with catecholamines. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

GALAXY EVOLUTION IN THE MID-INFRARED GREEN VALLEY: A CASE OF THE A2199 SUPERCLUSTER

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

Lee, Gwang-Ho; Lee, Myung Gyoon; Sohn, Jubee

2015-02-20

We study the mid-infrared (MIR) properties of the galaxies in the A2199 supercluster at z = 0.03 to understand the star formation activity of galaxy groups and clusters in the supercluster environment. Using the Wide-field Infrared Survey Explorer data, we find no dependence of mass-normalized integrated star formation rates of galaxy groups/clusters on their virial masses. We classify the supercluster galaxies into three classes in the MIR color-luminosity diagram: MIR blue cloud (massive, quiescent, and mostly early-type), MIR star-forming sequence (mostly late-type), and MIR green valley galaxies. These MIR green valley galaxies are distinguishable from the optical green valley galaxiesmore » in the sense that they belong to the optical red sequence. We find that the fraction of each MIR class does not depend on the virial mass of each group/cluster. We compare the cumulative distributions of surface galaxy number density and cluster/group-centric distance for the three MIR classes. MIR green valley galaxies show the distribution between MIR blue cloud and MIR star-forming (SF) sequence galaxies. However, if we fix galaxy morphology, early- and late-type MIR green valley galaxies show different distributions. Our results suggest a possible evolutionary scenario of these galaxies: (1) late-type MIR SF sequence galaxies → (2) late-type MIR green valley galaxies → (3) early-type MIR green valley galaxies → (4) early-type MIR blue cloud galaxies. In this sequence, the star formation of galaxies is quenched before the galaxies enter the MIR green valley, and then morphological transformation occurs in the MIR green valley.« less

Some Observations on the Use of the Woodcock-Johnson Tests of Cognitive Ability in Adults with Head Injury.

ERIC Educational Resources Information Center

Tupper, David E.

1990-01-01

The study provides descriptive data on use of the Woodcock-Johnson Tests of Cognitive Ability with 39 adults with closed head injury. Correlational analyses indicated significant relationships between coma duration and performance on the Perceptual Speed and Memory clusters of the test. Time since injury did not correlate with test results.…

Is the Size Evolution of Massive Galaxies Accelerated in Cluster Environments?

NASA Astrophysics Data System (ADS)

Wilson, Gillian

2013-10-01

At z 1.6 the main progenitors of present-day massive clusters are undergoing rapid collapse, and have the highest rates of galaxy merging and assembly. Recent observational studies have hinted at accelerated galaxy evolution in dense environments at this epoch, including increased merger rates and rapid growth in galaxy size relative to the field. We propose WFC3 G102 spectroscopy and F125W {Broad J} imaging of a sample of four massive spectroscopically-confirmed clusters at z = 1.6. Our primary scientific goal is to leverage the CANDELS Wide Legacy dataset to carry out a head-to-head comparison of the sizes of cluster members relative to the field {as a function of stellar mass and Sersic index}, and quantify the role of environment in the observed rapid evolution in galaxy sizes since z = 2. These clusters are four of the highest significance overdensities in the 50 square degree SWIRE fields, and will evolve over time to have present-day masses similar to Coma. They were detected using IRAC [3.6]-[4.5] color, which identifies galaxy overdensities regardless of optically red or blue color. A heroic ground-based spectroscopic campaign has resulted in 44 spectroscopically-confirmed members. However this sample is heavily biased toward star-forming {SF} galaxies, and WFC3 spectroscopy is essential to definitively determine cluster membership for 200 members, without bias with respect to quiescent or SF type. The F125W {rest-frame V-band} imaging is necessary to measure the sizes and morphologies of cluster members. 17-passband broadband imaging spanning UV, optical, near-IR, Spitzer IR and Herschel far-IR is already in hand.

A multi-frequency analysis of possible dark matter contributions to M31 gamma-ray emissions

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

Beck, G.; Colafrancesco, S., E-mail: geoffrey.beck@wits.ac.za, E-mail: sergio.colafrancesco@wits.ac.za

We examine the possibility of a dark matter (DM) contribution to the recently observed gamma-ray spectrum seen in the M31 galaxy. In particular, we apply limits on Weakly Interacting Massive Particle DM annihilation cross-sections derived from the Coma galaxy cluster and the Reticulum II dwarf galaxy to determine the maximal flux contribution by DM annihilation to both the M31 gamma-ray spectrum and that of the Milky-Way Galactic Centre. We limit the energy range between 1 and 12 GeV in M31 and Galactic Centre spectra due to the limited range of former's data, as well as to encompass the high-energy gamma-raymore » excess observed in the latter target. In so doing, we will make use of Fermi-LAT data for all mentioned targets, as well as diffuse radio data for the Coma cluster. The multi-target strategy using both Coma and Reticulum II to derive cross-section limits, as well as multi-frequency data, ensures that our results are robust against the various uncertainties inherent in modelling of indirect DM emissions. Our results indicate that, when a Navarro-Frenk-White (or shallower) radial density profile is assumed, severe constraints can be imposed upon the fraction of the M31 and Galactic Centre spectra that can be accounted for by DM, with the best limits arising from cross-section constraints from Coma radio data and Reticulum II gamma-ray limits. These particular limits force all the studied annihilation channels to contribute 1% or less to the total integrated gamma-ray flux within both M31 and Galactic Centre targets. In contrast, considerably more, 10−100%, of the flux can be attributed to DM when a contracted Navarro-Frenk-White profile is assumed. This demonstrates how sensitive DM contributions to gamma-ray emissions are to the possibility of cored profiles in galaxies. The only channel consistently excluded for all targets and profiles (except for ∼ 10 GeV WIMPs) is the direct annihilation into photons. Finally, we discuss the ramifications of evidence in favour of cored halo density profiles for DM explanations of galactic gamma-ray emission.« less

Observations of rich clusters of galaxies at metre wavelengths

NASA Technical Reports Server (NTRS)

Cane, H. V.; Erickson, W. C.; Hanisch, R. J.; Turner, P. J.

1981-01-01

Observations have been made at 10 frequencies between 50 and 120 MHz of 17 rich, X-ray emitting clusters of galaxies with the 78 x 156 m dipole array al Llanherne. The observed flux densities were compared to the flux densities expected on the basis of the known discrete sources in the fields. In no case was a significant flux excess found that might have indicated the presence of a diffuse halo component of radio emission in the cluster. For those clusters in which spectral indices could be determined, the spectra all tend to be much steeper than is normal for extragalactic radio sources, although a strict correlation between the X-ray luminosity and the low-frequency radio luminosity or spectral index is not found. The occurrence of large halo sources such as that which is present in the Coma cluster seems to be quite unusual.

The Fundamental Plane and the Surface Brightness Test for the Expansion of the Universe

NASA Astrophysics Data System (ADS)

Kjaergaard, Per; Jorgensen, Inger; Moles, Mariano

1993-12-01

We have determined the Petrosian radius, rη , and the enclosed mean surface brightness within the Petrosian radius, <μ>η, for 33 elliptical and S0 galaxies in the Coma cluster from new accurate CCD surface photometry. For the Petrosian parameter η = 1.39, rη and <μ>η are compared with the effective radius, re, and the effective mean surface brightness, <μ>e derived from fitting a de Vaucouleurs law. The fundamental plane (FP) expressed using rη and <μ>η is the same as the FP found by Jørgensen, Franx, & Kjaergaard (1993) using re and <μ>e. The FP can be used to predict the mean surface brightness within the effective radius or the corresponding Petrosian radius (η = 1.39) with an uncertainty of ±0.14 mag for Coma cluster ellipticals. Thus the FP, applied to clusters, appears to be a suitable tool for performing the surface brightness test (SBT) for the expansion of the universe. We suggest that instead of correcting individual galaxies to some standard conditions, e.g., the same metric radius, the fundamental plane itself should be considered the standard. It is argued that the metric size enclosing around 75% of the total light represents a reasonable compromise between resolution and faint level detection when performing the SBT. This radius could be derived as the Petrosian radius corresponding to η = 2.0 or from a global fit to that part of the observed profile which encompasses 75% of the total light. In case both small and large galaxies are well described by a de Vaucouleurs law the global fit can be performed on a smaller central part of the brightness profile. The use of the FP involves the time consuming determinations of velocity dispersions. We find that <μ>η (η = 1.39) can be predicted from the log rη alone with an accuracy of 0.3 mag for the Coma cluster ellipticals. Our discussion of the various error contributions to the predicted mean surface brightness for faint cluster ellipticals at redshifts z < 0.5 shows that the final error is probably dominated by extra scatter due to, e.g., environmental and evolutionary effects. Thus it might be possible that the use of velocity dispersions are not necessary. To get significant results for the SBT, clusters out to a redshift of approximately z = 0.3 have to be observed. For the most distant galaxies light levels down to about 25-26 mag arcsec-2 in the red and sizes as small as approximately 2" have to be accurately measured. We outline an observational program which will allow the control of the different sources of scatter, including cosmic evolution, producing conclusive results about the expansion of the universe.

Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center

NASA Astrophysics Data System (ADS)

Støstad, M.; Do, T.; Murray, N.; Lu, J. R.; Yelda, S.; Ghez, A.

2015-08-01

We present new near-infrared spectroscopic observations of the outer edges of the young stellar cluster around the supermassive black hole at the Galactic center. The observations show a break in the surface density profile of young stars at ˜13″ (0.52 pc). These observations spectroscopically confirm previous suggestions of a break based on photometry. Using Gemini North's Near-Infrared Integral Field Spectrometer, we are able to detect and separate early- and late-type stars with a 75% completeness at {K}{{s}}=15.5. We sample a region with radii between 7″ and 23″ (0.28-0.92 pc) from Sgr A* and present new spectral classifications of 144 stars brighter than {K}{{s}}=15.5, where 140 stars are late-type (\\gt 1 Gyr) and only four stars are early-type (young, 4-6 Myr). A broken power-law fit of the early-type surface density matches well with our data and previously published values. The projected surface density of late-type stars is also measured and found to be consistent with previous results. We find that the observed early-type surface-density profile is inconsistent with the theory of young stars originating from a tightly bound infalling cluster, as no significant trail of young stars is found at radii above 13″. We also note that either a simple disk instability criterion or a cloud-cloud collision could explain the location of the outer edge, though we lack information to make conclusive remarks on either alternative. If this break in surface density represents an edge to the young stellar cluster, it would set an important scale for the most recent episode of star formation at the Galactic center.

The evolution of the cluster optical galaxy luminosity function between z = 0.4 and 0.9 in the DAFT/FADA survey

NASA Astrophysics Data System (ADS)

Martinet, Nicolas; Durret, Florence; Guennou, Loïc; Adami, Christophe; Biviano, Andrea; Ulmer, Melville P.; Clowe, Douglas; Halliday, Claire; Ilbert, Olivier; Márquez, Isabel; Schirmer, Mischa

2015-03-01

Context. There is some disagreement about the abundance of faint galaxies in high-redshift clusters, with contradictory results in the literature arising from studies of the optical galaxy luminosity function (GLF) for small cluster samples. Aims: We compute GLFs for one of the largest medium-to-high-redshift (0.4 ≤ z < 0.9) cluster samples to date in order to probe the abundance of faint galaxies in clusters. We also study how the GLF depends on cluster redshift, mass, and substructure and compare the GLFs of clusters with those of the field. We separately investigate the GLFs of blue and red-sequence (RS) galaxies to understand the evolution of different cluster populations. Methods: We calculated the GLFs for 31 clusters taken from the DAFT/FADA survey in the B,V,R, and I rest-frame bands. We used photometric redshifts computed from BVRIZJ images to constrain galaxy cluster membership. We carried out a detailed estimate of the completeness of our data. We distinguished the red-sequence and blue galaxies using a V - I versus I colour-magnitude diagram. We studied the evolution of these two populations with redshift. We fitted Schechter functions to our stacked GLFs to determine average cluster characteristics. Results: We find that the shapes of our GLFs are similar for the B,V,R, and I bands with a drop at the red GLF faint ends that is more pronounced at high redshift: αred ~ -0.5 at 0.40 ≤ z < 0.65 and αred > 0.1 at 0.65 ≤ z < 0.90. The blue GLFs have a steeper faint end (αblue ~ -1.6) than the red GLFs, which appears to be independent of redshift. For the full cluster sample, blue and red GLFs meet at MV = -20, MR = -20.5, and MI = -20.3. A study of how galaxy types evolve with redshift shows that late-type galaxies appear to become early types between z ~ 0.9 and today. Finally, the faint ends of the red GLFs of more massive clusters appear to be richer than less massive clusters, which is more typical of the lower redshift behaviour. Conclusions: Our results indicate that these clusters form at redshifts higher than z = 0.9 from galaxy structures that already have an established red sequence. Late-type galaxies then appear to evolve into early types, enriching the red sequence between this redshift and today. This effect is consistent with the evolution of the faint-end slope of the red sequence and the galaxy type evolution that we find. Finally, faint galaxies accreted from the field environment at all redshifts might have replaced the blue late-type galaxies that converted into early types, explaining the lack of evolution in the faint-end slopes of the blue GLFs. Appendix is available in electronic form at http://www.aanda.org

Young, metal-enriched cores in early-type dwarf galaxies in the Virgo cluster based on colour gradients

NASA Astrophysics Data System (ADS)

Urich, Linda; Lisker, Thorsten; Janz, Joachim; van de Ven, Glenn; Leaman, Ryan; Boselli, Alessandro; Paudel, Sanjaya; Sybilska, Agnieszka; Peletier, Reynier F.; den Brok, Mark; Hensler, Gerhard; Toloba, Elisa; Falcón-Barroso, Jesús; Niemi, Sami-Matias

2017-10-01

Early-type dwarf galaxies are not simply featureless, old objects, but were found to be much more diverse, hosting substructures and a variety of stellar population properties. To explore the stellar content of faint early-type galaxies, and to investigate in particular those with recent central star formation, we study colours and colour gradients within one effective radius in optical (g - r) and near-infrared (I - H) bands for 120 Virgo cluster early-type galaxies with - 19 mag

Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies.

PubMed

McConnell, Nicholas J; Ma, Chung-Pei; Gebhardt, Karl; Wright, Shelley A; Murphy, Jeremy D; Lauer, Tod R; Graham, James R; Richstone, Douglas O

2011-12-08

Observational work conducted over the past few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that some were powered by black holes with masses greater than 10 billion solar masses, the remnants of these objects have not been found in the nearby Universe. The giant elliptical galaxy Messier 87 hosts the hitherto most massive known black hole, which has a mass of 6.3 billion solar masses. Here we report that NGC 3842, the brightest galaxy in a cluster at a distance from Earth of 98 megaparsecs, has a central black hole with a mass of 9.7 billion solar masses, and that a black hole of comparable or greater mass is present in NGC 4889, the brightest galaxy in the Coma cluster (at a distance of 103 megaparsecs). These two black holes are significantly more massive than predicted by linearly extrapolating the widely used correlations between black-hole mass and the stellar velocity dispersion or bulge luminosity of the host galaxy. Although these correlations remain useful for predicting black-hole masses in less massive elliptical galaxies, our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes.

[The myxoedema coma exists, we met it].

PubMed

Fritsch, N; Tran-Van, D; Dardare, E; Gentile, A; Deroudilhe, G; Fontaine, B

2007-09-01

The myxoedema coma corresponds to the ultimate evolution of a hypothyroidism and is characterized by a major deficit in thyroid hormones responsible for a collapse of the metabolism. The preventive and curative treatment is based on the administration of thyroid hormones, whose benefits are opposed to the cardiovascular risks related to an iatrogenic hyperthyroidism for patients often old with cardiopathy. We report the case of a 92-year-old patient with unbalanced hypothyroidism and chronic cardiac deficiency, who presented a myxoedema coma in the postoperative period of an urgent digestive surgery. This observation illustrates the difficulties in treating patients with unbalanced hypothyroidism following emergency surgery, in the absence of consensus on the type and the amounts of thyroid hormones substitution.

High β effects on cosmic ray streaming in galaxy clusters

NASA Astrophysics Data System (ADS)

Wiener, Joshua; Zweibel, Ellen G.; Oh, S. Peng

2018-01-01

Diffuse, extended radio emission in galaxy clusters, commonly referred to as radio haloes, indicate the presence of high energy cosmic ray (CR) electrons and cluster-wide magnetic fields. We can predict from theory the expected surface brightness of a radio halo, given magnetic field and CR density profiles. Previous studies have shown that the nature of CR transport can radically effect the expected radio halo emission from clusters (Wiener, Oh & Guo 2013). Reasonable levels of magnetohydrodynamic (MHD) wave damping can lead to significant CR streaming speeds. But a careful treatment of MHD waves in a high β plasma, as expected in cluster environments, reveals damping rates may be enhanced by a factor of β1/2. This leads to faster CR streaming and lower surface brightnesses than without this effect. In this work, we re-examine the simplified, 1D Coma cluster simulations (with radial magnetic fields) of Wiener et al. (2013) and discuss observable consequences of this high β damping. Future work is required to study this effect in more realistic simulations.

Low Metallicities and Old Ages for Three Ultra-diffuse Galaxies in the Coma Cluster

NASA Astrophysics Data System (ADS)

Gu, Meng; Conroy, Charlie; Law, David; van Dokkum, Pieter; Yan, Renbin; Wake, David; Bundy, Kevin; Merritt, Allison; Abraham, Roberto; Zhang, Jielai; Bershady, Matthew; Bizyaev, Dmitry; Brinkmann, Jonathan; Drory, Niv; Grabowski, Kathleen; Masters, Karen; Pan, Kaike; Parejko, John; Weijmans, Anne-Marie; Zhang, Kai

2018-05-01

A large population of ultra-diffuse galaxies (UDGs) was recently discovered in the Coma cluster. Here we present optical spectra of three such UDGs, DF 7, DF 44, and DF 17, which have central surface brightnesses of μ g ≈ 24.4–25.1 mag arcsec‑2. The spectra were acquired as part of an ancillary program within the SDSS-IV MaNGA Survey. We stacked 19 fibers in the central regions from larger integral field units (IFUs) per source. With over 13.5 hr of on-source integration, we achieved a mean signal-to-noise ratio in the optical of 9.5 Å‑1, 7.9 Å‑1, and 5.0 Å‑1, respectively, for DF 7, DF 44, and DF 17. Stellar population models applied to these spectra enable measurements of recession velocities, ages, and metallicities. The recession velocities of DF 7, DF 44, and DF 17 are {6599}-25+40 km s‑1, {6402}-39+41 km s‑1, and {8315}-43+43 km s‑1, spectroscopically confirming that all of them reside in the Coma cluster. The stellar populations of these three galaxies are old and metal-poor, with ages of {7.9}-2.5+3.6 Gyr, {8.9}-3.3+4.3 Gyr, and {9.1}-5.5+3.9 Gyr, and iron abundances of [Fe/H] -{1.0}-0.4+0.3, -{1.3}-0.4+0.4, and -{0.8}-0.5+0.5, respectively. Their stellar masses are (3–6) × 108 M ⊙. The UDGs in our sample are as old or older than galaxies at similar stellar mass or velocity dispersion (only DF 44 has an independently measured dispersion). They all follow the well-established stellar mass–stellar metallicity relation, while DF 44 lies below the velocity dispersion-metallicity relation. These results, combined with the fact that UDGs are unusually large for their stellar masses, suggest that stellar mass plays a more important role in setting stellar population properties for these galaxies than either size or surface brightness.

Discovery of an Ultra-diffuse Galaxy in the Pisces--Perseus Supercluster

NASA Astrophysics Data System (ADS)

Martínez-Delgado, David; Läsker, Ronald; Sharina, Margarita; Toloba, Elisa; Fliri, Jürgen; Beaton, Rachael; Valls-Gabaud, David; Karachentsev, Igor D.; Chonis, Taylor S.; Grebel, Eva K.; Forbes, Duncan A.; Romanowsky, Aaron J.; Gallego-Laborda, J.; Teuwen, Karel; Gómez-Flechoso, M. A.; Wang, Jie; Guhathakurta, Puragra; Kaisin, Serafim; Ho, Nhung

2016-04-01

We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10.°4 in projection from the Andromeda galaxy (M31). This low-surface brightness galaxy (μV = 24.8 mag arcsec-2), found with a small amateur telescope, appears unresolved in sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, in spite of its relatively large effective radius (Re(V) = 12″) and proximity (15‧) to the well-known dwarf spheroidal galaxy And II. Its red color (V - I = 1.0), shallow Sérsic index (nV = 0.68), and the absence of detectable Hα emission are typical properties of dwarf spheroidal galaxies and suggest that it is mainly composed of old stars. Initially interpreted as an interesting case of an isolated dwarf spheroidal galaxy in the local universe, our radial velocity measurement obtained with the BTA 6 m telescope (Vh = 5450 ± 40 km s-1) shows that this system is an M31-background galaxy associated with the filament of the Pisces-Perseus supercluster. At the distance of this cluster (˜78 Mpc), DGSAT I would have an Re ˜ 4.7 kpc and MV ˜ -16.3. Its properties resemble those of the ultra-diffuse galaxies (UDGs) recently discovered in the Coma cluster. DGSAT I is the first case of these rare UDGs found in this galaxy cluster. Unlike the UDGs associated with the Coma and Virgo clusters, DGSAT I is found in a much lower density environment, which provides a fresh constraint on the formation mechanisms for this intriguing class of galaxy.

On the Origins of Starburst and Poststarburst Galaxies in Nearby Clusters

NASA Astrophysics Data System (ADS)

Caldwell, Nelson; Rose, James A.; Dendy, Kristi

1999-01-01

Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images in B (F450W) and I (F814W) have been obtained for three starburst (SB) and two poststarburst (PSB) galaxies in the Coma Cluster and for three such galaxies in the cluster DC 048-52. V (F555W) and I images for an additional PSB galaxy in Coma have been extracted from the HST archive. Six of these galaxies were previously classified as E/S0 on the basis of ground-based images, two as Sa, and the other as an irregular. The HST images reveal these SB/PSB galaxies to be heterogeneous in morphology. Nevertheless, a common theme is that many of them, especially the SB galaxies, tend to have centralized spiral structure that appears simply as a bright ``bulge'' on ground-based images. In addition, while some PSB galaxies exhibit distinct spiral structure, on the whole they have smoother morphologies than the SB galaxies. The morphologies and luminosity profiles are generally consistent with substantial starbursts, in the form of centralized spiral structure (the SB galaxies), that fade into smoother morphologies (the PSB galaxies), with lingering spectroscopic evidence for past central starbursts. An important point is that the PSB galaxies retain disks; i.e., they have not evolved into spheroidal systems. While the morphologies revealed in the HST images are heterogeneous, and thus may not fit well into a single picture, we see evidence in several cases that the morphologies and centralized star formation have been driven by external tidal perturbations. We discuss several physical mechanisms for inducing star formation in cluster galaxies with a view toward explaining the particular morphologies seen in the HST images.

DISCOVERY OF AN ULTRA-DIFFUSE GALAXY IN THE PISCES-PERSEUS SUPERCLUSTER

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

Martínez-Delgado, David; Grebel, Eva K.; Läsker, Ronald

We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10.°4 in projection from the Andromeda galaxy (M31). This low-surface brightness galaxy (μ{sub V} = 24.8 mag arcsec{sup −2}), found with a small amateur telescope, appears unresolved in sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, in spite of its relatively large effective radius (R{sub e}(V) = 12″) and proximity (15′) to the well-known dwarf spheroidal galaxy And II. Its red color (V − I = 1.0), shallow Sérsic index (n{sub V} = 0.68), and the absence of detectable Hα emission aremore » typical properties of dwarf spheroidal galaxies and suggest that it is mainly composed of old stars. Initially interpreted as an interesting case of an isolated dwarf spheroidal galaxy in the local universe, our radial velocity measurement obtained with the BTA 6 m telescope (V{sub h} = 5450 ± 40 km s{sup −1}) shows that this system is an M31-background galaxy associated with the filament of the Pisces-Perseus supercluster. At the distance of this cluster (∼78 Mpc), DGSAT I would have an R{sub e} ∼ 4.7 kpc and M{sub V} ∼ −16.3. Its properties resemble those of the ultra-diffuse galaxies (UDGs) recently discovered in the Coma cluster. DGSAT I is the first case of these rare UDGs found in this galaxy cluster. Unlike the UDGs associated with the Coma and Virgo clusters, DGSAT I is found in a much lower density environment, which provides a fresh constraint on the formation mechanisms for this intriguing class of galaxy.« less

Right median nerve electrical stimulation for acute traumatic coma (the Asia Coma Electrical Stimulation trial): study protocol for a randomised controlled trial.

PubMed

Wu, Xiang; Zhang, Chao; Feng, Junfeng; Mao, Qing; Gao, Guoyi; Jiang, Jiyao

2017-07-10

Traumatic brain injury (TBI) has become the most common cause of death and disability in persons between 15 and 30 years of age, and about 10-15% of patients affected by TBI will end up in a coma. Coma caused by TBI presents a significant challenge to neuroscientists. Right median nerve electrical stimulation has been reported as a simple, inexpensive, non-invasive technique to speed recovery and improve outcomes for traumatic comatose patients. This multicentre, prospective, randomised (1:1) controlled trial aims to demonstrate the efficacy and safety of electrical right median nerve stimulation (RMNS) in both accelerating emergence from coma and promoting long-term outcomes. This trial aims to enrol 380 TBI comatose patients to partake in either an electrical stimulation group or a non-stimulation group. Patients assigned to the stimulation group will receive RMNS in addition to standard treatment at an amplitude of 15-20 mA with a pulse width of 300 μs at 40 Hz ON for 20 s and OFF for 40 s. The electrical treatment will last for 8 h per day for 2 weeks. The primary endpoint will be the percentage of patients regaining consciousness 6 months after injury. The secondary endpoints will be Extended Glasgow Outcome Scale, Coma Recovery Scale-Revised and Disability Rating Scale scores at 28 days, 3 months and 6 months after injury; Glasgow Coma Scale, Glasgow Coma Scale Motor Part and Full Outline of Unresponsiveness scale scores on day 1 and day 7 after enrolment and 28 days, 3 months and 6 months after injury; duration of unconsciousness and mechanical ventilation; length of intensive care unit and hospital stays; and incidence of adverse events. Right median nerve electrical stimulation has been used as a safe, inexpensive, non-invasive therapy for neuroresuscitation of coma patients for more than two decades, yet no trial has robustly proven the efficacy and safety of this treatment. The Asia Coma Electrical Stimulation (ACES) trial has the following novel features compared with other major RMNS trials: (1) the ACES trial is an Asian multicentre randomised controlled trial; (2) RMNS therapy starts at an early stage 7-14 days after the injury; and (3) various assessment scales are used to evaluate the condition of patients. We hope the ACES trial will lead to optimal use of right median nerve electrical treatment. ClinicalTrials.gov, NCT02645578 . Registered on 23 December 2015.

Can sterile neutrinos be ruled out as warm dark matter candidates?

PubMed

Viel, Matteo; Lesgourgues, Julien; Haehnelt, Martin G; Matarrese, Sabino; Riotto, Antonio

2006-08-18

We present constraints on the mass of warm dark matter (WDM) particles from a combined analysis of the matter power spectrum inferred from the Sloan Digital Sky Survey Lyman-alpha flux power spectrum at 2.2

Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure.

PubMed

Lee, William M; Hynan, Linda S; Rossaro, Lorenzo; Fontana, Robert J; Stravitz, R Todd; Larson, Anne M; Davern, Timothy J; Murray, Natalie G; McCashland, Timothy; Reisch, Joan S; Robuck, Patricia R

2009-09-01

N-acetylcysteine (NAC), an antidote for acetaminophen poisoning, might benefit patients with non-acetaminophen-related acute liver failure. In a prospective, double-blind trial, acute liver failure patients without clinical or historical evidence of acetaminophen overdose were stratified by site and coma grade and assigned randomly to groups that were given NAC or placebo (dextrose) infusion for 72 hours. The primary outcome was overall survival at 3 weeks. Secondary outcomes included transplant-free survival and rate of transplantation. A total of 173 patients received NAC (n = 81) or placebo (n = 92). Overall survival at 3 weeks was 70% for patients given NAC and 66% for patients given placebo (1-sided P = .283). Transplant-free survival was significantly better for NAC patients (40%) than for those given placebo (27%; 1-sided P = .043). The benefits of transplant-free survival were confined to the 114 patients with coma grades I-II who received NAC (52% compared with 30% for placebo; 1-sided P = .010); transplant-free survival for the 59 patients with coma grades III-IV was 9% in those given NAC and 22% in those given placebo (1-sided P = .912). The transplantation rate was lower in the NAC group but was not significantly different between groups (32% vs 45%; P = .093). Intravenous NAC generally was well tolerated; only nausea and vomiting occurred significantly more frequently in the NAC group (14% vs 4%; P = .031). Intravenous NAC improves transplant-free survival in patients with early stage non-acetaminophen-related acute liver failure. Patients with advanced coma grades do not benefit from NAC and typically require emergency liver transplantation.

Fatal coma in a young adult due to late-onset urea cycle deficiency presenting with a prolonged seizure: a case report.

PubMed

Alameri, Majid; Shakra, Mustafa; Alsaadi, Taoufik

2015-11-23

Unexplained hyperammonemic coma in adults can be a medical dilemma in the absence of triggering factors and known comorbidities. Ornithine transcarbamylase deficiency presents most commonly with hyperammonemic coma. Although a rare disorder, ornithine transcarbamylase deficiency is the most common of the urea cycle disorders, which can occur both in children, and less commonly, in adults. The urea cycle disorder is usually acquired as an X-linked trait, and very rarely, similar to our reported case, may be acquired as a "new" mutation. Mutations that lead to later-onset presentations may lead to life-threatening disease and may be unrecognized, particularly when the first clinical symptoms occur in adulthood. We report the case of a previously healthy 17-year-old white man who developed a prolonged seizure and a rapid decline in mental status leading to coma over a 3-day period. Analysis of the OTC gene showed a 119G variant, which was identified in exon 2 of the OTC gene by sequencing. A diagnosis of ornithine transcarbamylase deficiency should be considered in adult patients who present with unexplained hyperammonemic coma and for all adult patients presenting with cryptogenic new-onset seizure and laboratory finding of elevated blood ammonia levels. This reported case highlights the importance of early recognition of this potentially reversible cause of life-threatening encephalopathy, as timely recognition and appropriate treatment can be lifesaving.

Contemporary Rates of Severe Hypoglycaemia in Youth with Type 1 Diabetes: Variability by Insulin Regimen

PubMed Central

Katz, M. L.; Volkening, L. K.; Anderson, B. J.; Laffel, L. M.

2013-01-01

Aims To determine incidence rates of severe hypoglycaemia and compare incidence rates by insulin regimen in a diverse sample of youth with type 1 diabetes from two sites. Methods In this observational study, 255 youth (51% female) aged 9–15 years receiving varied insulin regimens provided data prospectively for a median of 1.2 years. Reported episodes of severe hypoglycaemia, defined as episodes requiring help from another person for oral treatment or episodes resulting in seizure/coma, and current insulin regimens were collected systematically. Incidence rates were calculated and compared according to insulin regimen in bivariate and multivariate analyses. Results At first encounter, participants had a median age of 12.2 years (range 9.0–15.0), median diabetes duration of 4.4 years (range 1.0–13.0) and mean A1C of 67±12 mmol/mol (8.3±1.1%). The incidence rate was 37.6/100-patient-years for all severe hypoglycaemia and 9.6/100-patient-years for seizure/coma. The incidence rate for severe hypoglycaemia was 31.8/100-patient-years on continuous subcutaneous insulin infusion (CSII), 34.4/100-patient-years on basal-bolus injections (B-B) and 46.1/100-patient-years on NPH (NPH vs. CSII: p=.04). The incidence rate for seizure/coma was 4.5/100-patient-years on CSII, 11.1/100-patient-years on B-B, and 14.4/100-patient-years on NPH (NPH vs. CSII: p=.004). In the multivariate analysis, the rate of seizure/coma was significantly higher for those on NPH vs. CSII (rate ratio 2.9, p=.03). Conclusions Rates of severe hypoglycaemia in youth with type 1 diabetes remain high. CSII was associated with lower rates of all severe hypoglycaemia and seizure/coma in comparison to NPH. PMID:22417321

An X-Ray Survey of the Open Cluster NGC 6475 (M7) with ROSAT

NASA Technical Reports Server (NTRS)

Prosser, Charles F.; Stauffer, John R.; Caillault, J.-P.; Balachandran, Suchitra; Stern, Robert A.; Randich, Sofia

1995-01-01

A ROSAT x-ray survey, with complimentary optical photometry, of the open cluster NGC 6475 has enabled the detection of approx. 50 late-F to K0 and approx. 70 K/M dwarf new candidate members, providing the first reliable detection of low-mass stars in this low. galactic latitude, 220 Myr old cluster. The x-ray observations reported here have a typical limiting sensitivity of L(sub x) approx. equal to 10(exp 29) erg/s. The detection frequency of early type cluster members is consistent with the hypothesis that the x-ray emitting early type stars are binary systems with an unseen, low-mass secondary producing the x rays. The ratio between x-ray and bolometric luminosity among NGC 6475 members saturates at a spectral-type/color which is intermediate between that in much younger and in much older clusters, consistent with rotational spindown of solar-type stars upon their arrival on the ZAMS. The upper envelope of x-ray luminosity as a function of spectral type is comparable to that of the Pleiades, with the observed spread in x-ray luminosity among low-mass members being likely due to the presence of binaries and relatively rapid rotators. However, the list of x-ray selected candidate members is likely biased against low-mass, slowly rotating single stars. While some preliminary spectroscopic information is given in an appendix, further spectroscopic observations of the new candidate members will aid in interpreting the coronal activity among solar-type NGC 6475 members and their relation to similar stars in older and younger open clusters.

Mass and size growth of early-type galaxies by dry mergers in cluster environments

NASA Astrophysics Data System (ADS)

Oogi, Taira; Habe, Asao; Ishiyama, Tomoaki

2016-02-01

We perform dry merger simulations to investigate the role of dry mergers in the size growth of early-type galaxies in high-density environments. We replace the virialized dark matter haloes obtained by a large cosmological N-body simulation with N-body galaxy models consisting of two components, a stellar bulge and a dark matter halo, which have higher mass resolution than the cosmological simulation. We then resimulate nine cluster-forming regions, whose masses range from 1 × 1014 to 5 × 1014 M⊙. Masses and sizes of stellar bulges are also assumed to satisfy the stellar mass-size relation of high-z compact massive early-type galaxies. We find that dry major mergers considerably contribute to the mass and size growth of central massive galaxies. One or two dry major mergers double the average stellar mass and quadruple the average size between z = 2 and 0. These growths favourably agree with observations. Moreover, the density distributions of our simulated central massive galaxies grow from the inside-out, which is consistent with recent observations. The mass-size evolution is approximated as R∝ M_{{ast }}^{α }, with α ˜ 2.24. Most of our simulated galaxies are efficiently grown by dry mergers, and their stellar mass-size relations match the ones observed in the local Universe. Our results show that the central galaxies in the cluster haloes are potential descendants of high-z (z ˜ 2-3) compact massive early-type galaxies. This conclusion is consistent with previous numerical studies which investigate the formation and evolution of compact massive early-type galaxies.

The kinematic properties of dwarf early-type galaxies in the Virgo cluster

NASA Astrophysics Data System (ADS)

Toloba, E.; Boselli, A.; Peletier, R. F.; Gorgas, J.

2011-11-01

We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster. These data are used to study the origin of dEs inhabiting clusters. Within them we detect two populations: half of the sample (52%) are rotationally supported and the other half are pressure supported. We also find that the rotationally supported dEs are located in the outer parts of the cluster, present disky morphological shapes and are younger than those pressure supported that are concentrated in the core of the cluster without any underlying structures. Our analysis reveals that the rotationally supported objects have rotation curves similarly shaped to those of star forming galaxies of similar luminosities and follow the Tully-Fisher relation. This is expected if dEs are the descendant of low luminosity star forming systems which recently entered the cluster and lost their gas due to a ram pressure stripping event, quenching their star formation activity and transforming them into quiescent systems, but conserving their angular momentum.

An X-ray and optical study of the cluster of galaxies Abell 754

NASA Technical Reports Server (NTRS)

Fabricant, D.; Beers, T. C.; Geller, M. J.; Gorenstein, P.; Huchra, J. P.

1986-01-01

X-ray and optical data for A754 are used to study the relative distribution of the luminous and dark matter in this dense, rich cluster of galaxies with X-ray luminosity comparable to that of the Coma Cluster. A quantitative statistical comparison is made of the galaxy positions with the total mass responsible for maintaining the X-ray emitting gas in hydrostatic equilibrium. A simple bimodal model which fits both the X-ray and optical data suggests that the galaxies are distributed consistently with the projected matter distribution within the region covered by the X-ray map (0.5-1 Mpc). The X-ray and optical estimates of the mass in the central region of the cluster are 2.9 x 10 to the 14th and 3.6 + or - 0.5 x 10 to the 14th solar masses, respectively.

Synergism of isothermal regimen and sodium succinate in experimental therapy of barbiturate coma.

PubMed

Reinyuk, V L; Shefer, T V; Ivnitskii, Yu Yu

2006-07-01

In rats with experimental thiopental coma rectal temperature decreased by 9.4 degrees C, oxygen consumption 5-fold, and arteriovenous Po(2)gradient decreased 2-fold within 3 h; CO(2)accumulated in the blood and mixed type acidosis developed. Administration of sodium succinate under these conditions increased arteriovenous Po(2)gradient and reduced manifestations of metabolic acidosis. Maintenance of normal body temperature (warming) corrected primarily manifestations of respiratory acidosis. Each therapeutic agent reduced inhibition of O(2)consumption by 1/4; animal survival tended to increase from 42 to 50%. Combined use of these treatments potentiated the antiacidotic effect and increased survival to 92%. The authors conclude that hypothermia inhibits the therapeutic effect of succinate in barbiturate coma.

Origin of the fundamental plane of elliptical galaxies in the Coma cluster without fine-tuning

NASA Astrophysics Data System (ADS)

Chiu, Mu-Chen; Ko, Chung-Ming; Shu, Chenggang

2017-03-01

Thirty years after the discovery of the fundamental plane, explanations of the tilt of the fundamental plane with respect to the virial plane are still in need of fine-tuning. In this paper, we try to explore the origin of this tilt from the perspective of modified Newtonian dynamics (MOND) by applying the 16 Coma galaxies available in J. Thomas et al. [Mon. Not. R. Astron. Soc. 415, 545 (2011), 10.1111/j.1365-2966.2011.18725.x]. Based on the mass models that can reproduce de Vaucouleurs' law closely, we find that the tilt of the traditional fundamental plane is naturally explained by the simple form of the MONDian interpolating function, if we assume a well motivated choice of anisotropic velocity distribution, and adopt the Kroupa or Salpeter stellar mass-to-light ratio. Our analysis does not necessarily rule out a varying stellar mass-to-light ratio.

Angular and energy distribution of low energy cometary ions measured in the outer coma of Comet Halley

NASA Technical Reports Server (NTRS)

Berthelier, J. J.; Illiano, J. M.; Hodges, R. R.; Krankowsky, D.; Eberhardt, P.; Laemmerzahl, P.; Hoffman, J. H.; Herrwerth, I.; Woweries, J.; Dolder, U.

1986-01-01

During the early phase of the Giotto encounter with comet Halley, at distances from the nucleus greater than 350,000 km, the neutral mass spectrometer was operated in a mode allowing the measurement of low energy ions. Data reveal two important features of the outer coma: the presence of a sharp discontinuity in the plasma flow at 550,000 km from the nucleus which results in a significant decrease of the plasma flow accompanied by an increase in temperature; and the detection of newly born ions identified as O(+) and CO(+), at distances from the comet greater than 800,000 km.

Consonant Cluster Production in Children with Cochlear Implants: A Comparison with Normally Hearing Peers

ERIC Educational Resources Information Center

Faes, Jolien; Gillis, Steven

2017-01-01

In early word productions, the same types of errors are manifest in children with cochlear implants (CI) as in their normally hearing (NH) peers with respect to consonant clusters. However, the incidence of those types and their longitudinal development have not been examined or quantified in the literature thus far. Furthermore, studies on the…

Characteristics of Near-Death Experiences Memories as Compared to Real and Imagined Events Memories

PubMed Central

Brédart, Serge; Dehon, Hedwige; Ledoux, Didier; Laureys, Steven; Vanhaudenhuyse, Audrey

2013-01-01

Since the dawn of time, Near-Death Experiences (NDEs) have intrigued and, nowadays, are still not fully explained. Since reports of NDEs are proposed to be imagined events, and since memories of imagined events have, on average, fewer phenomenological characteristics than real events memories, we here compared phenomenological characteristics of NDEs reports with memories of imagined and real events. We included three groups of coma survivors (8 patients with NDE as defined by the Greyson NDE scale, 6 patients without NDE but with memories of their coma, 7 patients without memories of their coma) and a group of 18 age-matched healthy volunteers. Five types of memories were assessed using Memory Characteristics Questionnaire (MCQ – Johnson et al., 1988): target memories (NDE for NDE memory group, coma memory for coma memory group, and first childhood memory for no memory and control groups), old and recent real event memories and old and recent imagined event memories. Since NDEs are known to have high emotional content, participants were requested to choose the most emotionally salient memories for both real and imagined recent and old event memories. Results showed that, in NDE memories group, NDE memories have more characteristics than memories of imagined and real events (p<0.02). NDE memories contain more self-referential and emotional information and have better clarity than memories of coma (all ps<0.02). The present study showed that NDE memories contained more characteristics than real event memories and coma memories. Thus, this suggests that they cannot be considered as imagined event memories. On the contrary, their physiological origins could lead them to be really perceived although not lived in the reality. Further work is needed to better understand this phenomenon. PMID:23544039

Galaxy collisions as a mechanism of ultra diffuse galaxy (UDG) formation

NASA Astrophysics Data System (ADS)

Baushev, A. N.

2018-04-01

We suggest a possible mechanism of ultra diffuse galaxy formation: the UDGs may occur as a result of a central collision of galaxies. If the galaxies are young and contain a lot of gas, the collision may kick all the gas off the systems and thus strongly suppress any further star formation. As a result, the galaxies now have a very low surface brightness and other properties typical of the ultra diffuse galaxies. We use the Coma cluster (where numerous UDGs were recently discovered) to test the efficiency of the process. The mechanism works very well and can transform a significant fraction of the cluster population into ultra diffuse galaxies. The UDGs formed by the process concentrate towards the center of the cluster, and their globular cluster systems remain undamaged, in accordance with observational results. The projected surface density of UDGs in the cluster may help us to recognize the mechanism of UDG formation, or clarify relative contributions of several possible competitive mechanisms at work.

STELLAR KINEMATICS AND STRUCTURAL PROPERTIES OF VIRGO CLUSTER DWARF EARLY-TYPE GALAXIES FROM THE SMAKCED PROJECT. III. ANGULAR MOMENTUM AND CONSTRAINTS ON FORMATION SCENARIOS

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

Toloba, E.; Guhathakurta, P.; Boselli, A.

2015-02-01

We analyze the stellar kinematics of 39 dwarf early-type galaxies (dEs) in the Virgo Cluster. Based on the specific stellar angular momentum λ{sub Re} and the ellipticity, we find 11 slow rotators and 28 fast rotators. The fast rotators in the outer parts of the Virgo Cluster rotate significantly faster than fast rotators in the inner parts of the cluster. Moreover, 10 out of the 11 slow rotators are located in the inner 3° (D < 1 Mpc) of the cluster. The fast rotators contain subtle disk-like structures that are visible in high-pass filtered optical images, while the slow rotatorsmore » do not exhibit these structures. In addition, two of the dEs have kinematically decoupled cores and four more have emission partially filling in the Balmer absorption lines. These properties suggest that Virgo Cluster dEs may have originated from late-type star-forming galaxies that were transformed by the environment after their infall into the cluster. The correlation between λ{sub Re} and the clustercentric distance can be explained by a scenario where low luminosity star-forming galaxies fall into the cluster, their gas is rapidly removed by ram-pressure stripping, although some of it can be retained in their core, their star formation is quenched but their stellar kinematics are preserved. After a long time in the cluster and several passes through its center, the galaxies are heated up and transformed into slow rotating dEs.« less

Balance of corneal horizontal coma by internal optics in eyes with intraocular artificial lenses: evidence of a passive mechanism.

PubMed

Marcos, Susana; Rosales, Patricia; Llorente, Lourdes; Barbero, Sergio; Jiménez-Alfaro, I

2008-01-01

It is well known that the aberrations of the cornea are partially compensated by the aberrations of the internal optics of the eye (primarily the crystalline lens) in young subjects. This effect has been found not only for the spherical aberration, but also for horizontal coma. It has been debated whether the compensation of horizontal coma is the result of passive mechanism [Artal, P., Benito, A., & Tabernero, J. (2006). The human eye is an example of robust optical design. Journal of Vision, 6 (1), 1-7] or through an active developmental feedback process [Kelly, J. E., Mihashi, T., & Howland, H. C. (2004). Compensation of corneal horizontal/vertical astigmatism, lateral coma, and spherical aberration by internal optics of the eye. Journal of Vision, 4 (4), 262-271]. In this study we investigate the active or passive nature of the horizontal coma compensation using eyes with artificial lenses, where no active developmental process can be present. We measured total and corneal aberrations, and lens tilt and decentration in a group of 38 eyes implanted with two types of intraocular lenses designed to compensate the corneal spherical aberration of the average population. We found that spherical aberration was compensated by 66%, and horizontal coma by 87% on average. The spherical aberration is not compensated at an individual level, but horizontal coma is compensated individually (coefficients of correlation corneal/internal aberration: -0.946, p<0.0001). The fact that corneal (but not total) horizontal coma is highly correlated with angle lamda (computed from the shift of the 1st Purkinje image from the pupil center, for foveal fixation) indicates that the compensation arises primarily from the geometrical configuration of the eye (which generates horizontal coma of opposite signs in the cornea and internal optics). The amount and direction of tilts and misalignments of the lens are comparable to those found in young eyes, and on average tend to compensate (rather than increase) horizontal coma. Computer simulations using customized model eyes and different designs of intraocular lenses show that, while not all designs produce a compensation of horizontal coma, a wide range of aspheric biconvex designs may produce comparable compensation to that found in young eyes with crystalline lenses, over a relatively large field of view. These findings suggest that the lens shape, gradient index or foveal location do not need to be fine-tuned to achieve a compensation of horizontal coma. Our results cannot exclude a fine-tuning for the orientation of the crystalline lens, since cataract surgery seems to preserve the position of the capsule.

Prospective Cohort Study Evaluating the Prognostic Value of Simple EEG Parameters in Postanoxic Coma.

PubMed

Azabou, Eric; Fischer, Catherine; Mauguiere, François; Vaugier, Isabelle; Annane, Djillali; Sharshar, Tarek; Lofaso, Fréderic

2016-01-01

We prospectively studied early bedside standard EEG characteristics in 61 acute postanoxic coma patients. Five simple EEG features, namely, isoelectric, discontinuous, nonreactive to intense auditory and nociceptive stimuli, dominant delta frequency, and occurrence of paroxysms were classified yes or no. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC) of each of these variables for predicting an unfavorable outcome, defined as death, persistent vegetative state, minimally conscious state, or severe neurological disability, as assessed 1 year after coma onset were computed as well as Synek's score. The outcome was unfavorable in 56 (91.8%) patients. Sensitivity, specificity, PPV, NPV, and AUC of nonreactive EEG for predicting an unfavorable outcome were 84%, 80%, 98%, 31%, and 0.82, respectively; and were all very close to the ones of Synek score>3, which were 82%, 80%, 98%, 29%, and 0.81, respectively. Specificities for predicting an unfavorable outcome were 100% for isoelectric, discontinuous, or dominant delta activity EEG. These 3 last features were constantly associated to unfavorable outcome. Absent EEG reactivity strongly predicted an unfavorable outcome in postanoxic coma, and performed as accurate as a Synek score>3. Analyzing characteristics of some simple EEG features may easily help nonneurophysiologist physicians to investigate prognostic issue of postanoxic coma patient. In this study (a) discontinuous, isoelectric, or delta-dominant EEG were constantly associated with unfavorable outcome and (b) nonreactive EEG performed prognostic as accurate as a Synek score>3. © EEG and Clinical Neuroscience Society (ECNS) 2015.

Group sequential designs for stepped-wedge cluster randomised trials

PubMed Central

Grayling, Michael J; Wason, James MS; Mander, Adrian P

2017-01-01

Background/Aims: The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Methods: Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. Results: We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial’s type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. Conclusion: The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into stepped-wedge cluster randomised trials according to the needs of the particular trial. PMID:28653550

Group sequential designs for stepped-wedge cluster randomised trials.

PubMed

Grayling, Michael J; Wason, James Ms; Mander, Adrian P

2017-10-01

The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into stepped-wedge cluster randomised trials according to the needs of the particular trial.

Spatial temporal clustering for hotspot using kulldorff scan statistic method (KSS): A case in Riau Province

NASA Astrophysics Data System (ADS)

Hudjimartsu, S. A.; Djatna, T.; Ambarwari, A.; Apriliantono

2017-01-01

The forest fires in Indonesia occurs frequently in the dry season. Almost all the causes of forest fires are caused by the human activity itself. The impact of forest fires is the loss of biodiversity, pollution hazard and harm the economy of surrounding communities. To prevent fires required the method, one of them with spatial temporal clustering. Spatial temporal clustering formed grouping data so that the results of these groupings can be used as initial information on fire prevention. To analyze the fires, used hotspot data as early indicator of fire spot. Hotspot data consists of spatial and temporal dimensions can be processed using the Spatial Temporal Clustering with Kulldorff Scan Statistic (KSS). The result of this research is to the effectiveness of KSS method to cluster spatial hotspot in a case within Riau Province and produces two types of clusters, most cluster and secondary cluster. This cluster can be used as an early fire warning information.

A CCD survey of galaxies. IV. Observations with the 2.1 M telescope at San Pedro Martir.

NASA Astrophysics Data System (ADS)

Gavazzi, G.; Boselli, A.; Carrasco, L.

1995-09-01

Continuing a CCD survey of galaxies belonging or projected onto the Coma and Hercules Superclusters, to the A262 and Cancer clusters, we present isophote maps and photometric profiles in the Johnson system of 111 galaxies (67 in the V and B bands, 42 only in V, 2 only in B) obtained with the 2.1 m telescope at San Pedro Martir (Baja California, Mexico).

VizieR Online Data Catalog: CCD Survey of Galaxies IV (Gavazzi+, 1995)

NASA Astrophysics Data System (ADS)

Gavazzi, G.; Boselli, A.; Carrasco, L.

1995-03-01

Continuing a CCD survey of galaxies belonging or projected onto the Coma and Hercules Superclusters, to the A262 and Cancer clusters, we present isophote maps and photometric profiles in the Johnson system of 111 galaxies (67 in the V and B bands, 42 only in V, 2 only in B) obtained with the 2.1m telescope at San Pedro Martir (Baja California, Mexico). (2 data files).

Higher-order aberrations of lenticular opacities.

PubMed

Sachdev, Nisha; Ormonde, Susan E; Sherwin, Trevor; McGhee, Charles N J

2004-08-01

To measure and quantify higher-order aberrations induced by different types of lenticular opacities. Department of Ophthalmology, University of Auckland, and Department of Ophthalmology, Auckland Public Hospital, Auckland, New Zealand. Patients with lenticular opacities were recruited from outpatient clinics of a major tertiary referral center for ophthalmology. Patients were included if they had clinically evident, mild to moderate lenticular opacity with no coexisting ocular pathology. Patients were examined using standard preoperative techniques with additional assessment by wavefront aberrometry (Zywave, Bausch & Lomb) and Scheimpflug photography (EAS-1000, Nidek). For comparison, 20 eyes of 10 subjects with no lenticular opacity (control group) were recruited and assessed in an identical manner. Thirty persons were recruited and 40 eyes assessed, 20 with lenticular opacities. Ten eyes had predominantly cortical opacification, and 10 had mainly nuclear opacification. In eyes with predominantly cortical opacification, the mean logMAR uncorrected visual acuity (UCVA) was 0.5 +/- 0.2 (SD) (6/18 Snellen equivalent) and the mean logMAR best spectacle-corrected visual acuity (BSCVA), 0.2 +/- 0.2 (6/9). Analysis of aberrometry data for a 6.0 mm pupil in this group revealed an increase in coma of cosine phase (Z(3), P =.06) and tetrafoil of cosine phase (Z(4), P =.07) compared to eyes in the control group. Eyes with predominantly nuclear opacification had a mean logMAR UCVA of 0.7 +/- 0.2 (6/30) and a logMAR BSCVA of 0.4 +/- 0.2 (6/15). Aberrometry data for this cohort for a 6.0 mm pupil showed a statistically greater amount of spherical aberration (Z(4)(0), P =.001) and tetrafoil of cosine phase (Z(4), P =.005; Z(4)(-4), P =.004). This pilot study suggests that different types of early lenticular opacities induce different wavefront aberration profiles. Predominantly cortical opacification produced an increase in coma and nuclear opacification induced an increase in spherical aberration compared to eyes without opacities. Both types of lenticular opacities also induced a higher amount of tetrafoil. This could explain the significant visual symptoms in patients with early cataract and relatively good high-contrast Snellen acuity.

Lithium Abundances in the Young Open Cluster IC 2602

NASA Technical Reports Server (NTRS)

Randich, S.; Aharpour, N.; Pallavicini, R.; Prosser, C. F.; Stauffer, J. R.

1997-01-01

We have obtained high-resolution spectra for 28 candidate late-type stars in the 30 Myr old cluster IC 2602. NLTE Li abundances have been derived from measured equivalent widths. The log n(Li) - T(sub eff) and log n(Li) - mass distributions for our sample stars have been compared with those of the Pleiades and alpha Persei. Our data show that F stars in the three clusters have the same lithium content, which corresponds to the initial content for Pop. I stars. G and early-K IC 2602 stars are, on average, somewhat more Li-rich than their counterparts in the two slightly older clusters. Finally, the latest-type IC 2602 stars are heavily Li depleted, with their Li content being as low as the lowest measured among the Pleiades. As in the Pleiades and alpha Per, a star-to-star scatter in lithium is observed among 30 Myr old late-K/early-K dwarfs in IC 2602, indicating that this spread develops in the pre-main sequence phases.

Mild decentration measured by a Scheimpflug camera and its impact on visual quality following SMILE in the early learning curve.

PubMed

Li, Meiyan; Zhao, Jing; Miao, Huamao; Shen, Yang; Sun, Ling; Tian, Mi; Wadium, Elizabeth; Zhou, Xingtao

2014-05-20

To measure decentration following femtosecond laser small incision lenticule extraction (SMILE) for the correction of myopia and myopic astigmatism in the early learning curve, and to investigate its impact on visual quality. A total of 55 consecutive patients (100 eyes) who underwent the SMILE procedure were included. Decentration was measured using a Scheimpflug camera 6 months after surgery. Uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction, and wavefront errors were also measured. Associations between decentration and the preoperative spherical equivalent were analyzed, as well as the associations between decentration and wavefront aberrations. Regarding efficacy and safety, 40 eyes (40%) had an unchanged CDVA; 32 eyes (32%) gained one line; and 11 eyes (11%) gained two lines. Fifteen eyes (15%) lost one line of CDVA, and two eyes (2%) lost two lines. Ninety-nine of the treated eyes (99%) had a postoperative UDVA better than 1.0, and 100 eyes (100%) had a UDVA better than 0.8. The mean decentered displacement was 0.17 ± 0.09 mm. The decentered displacement of all treated eyes (100%) was within 0.50 mm; 70 eyes (70%) were within 0.20 mm; and 90 eyes (90%) were within 0.30 mm. The vertical coma showed the greatest increase in magnitude. The magnitude of horizontal decentration was found to be associated with an induced horizontal coma. This study suggests that, although mild decentration occurred in the early learning curve, good visual outcomes were achieved after the SMILE surgery. Special efforts to minimize induced vertical coma are necessary. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Chemical composition of A and F dwarfs members of the Hyades open cluster

NASA Astrophysics Data System (ADS)

Gebran, M.; Vick, M.; Monier, R.; Fossati, L.

2010-11-01

Aims: Abundances of 15 chemical elements have been derived for 28 F and 16 A stars members of the Hyades open cluster in order to set constraints on self-consistent evolutionary models that include radiative and turbulent diffusion. Methods: A spectral synthesis, iterative procedure was applied to derive the abundances from selected high-quality lines in high-resolution, high-signal-to-noise spectra obtained with SOPHIE and AURELIE at the Observatoire de Haute Provence. Results: The abundance patterns found for A and F stars in the Hyades resemble those observed in Coma Berenices and Pleiades clusters. In graphs representing the abundances versus the effective temperature, A stars often display much more scattered abundances around their mean values than the coolest F stars do. Large star-to-star variations are detected in the Hyades A dwarfs in their abundances of C, Na, Sc, Fe, Ni, Sr, Y, and Zr, which we interpret as evidence of transport processes competing with radiative diffusion. In A and Am stars, the abundances of Cr, Ni, Sr, Y, and Zr are found to be correlated with that of Fe as in the Pleiades and in Coma Berenices. The ratios C/Fe and O/Fe are found to be anticorrelated with Fe/H as in Coma Berenices. All Am stars in the Hyades are deficient in C and O and overabundant in elements heavier than Fe but not all are deficient in Ca and/or Sc. The F stars have solar abundances for almost all elements except for Si. The overall shape of the abundance pattern of the slow rotator HD 30210 cannot be entirely reproduced by models including radiative diffusion and different amounts of turbulent diffusion. Conclusions: While part of the discrepancies between derived and predicted abundances could come from non-LTE effects, including competing processes such as rotational mixing and/or mass loss seems necessary in order to improve the agreement between the observed and predicted abundance patterns. Tables 5 to 8 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/523/A71Based on observations at the Observatoire de Haute-Provence, France.

Early Activity of Cometary Species from ROSINA/DFMS at 67P/ Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Hässig, Myrtha; Fuselier, Stephen A.; Altwegg, Kathrin; Balsiger, Hans; Berthelier, Jean-Jacques; Bieler, André; Calmonte, Ursina; Dhooghe, Frederik; Fiethe, Björn; Gasc, Sébastien; Gombosi, Tamas I.; Jäckel, Annette; Korth, Axel; Le Roy, Léna; Rème, Henri; Rubin, Martin; Tzou, Chia-Yu; Wurz, Peter

2014-11-01

The European Space Agency’s Rosetta spacecraft arrived after a journey of more than 10 years at comet 67P/Churyumov-Gerasimenko. ROSINA is an instrument package on board Rosetta. It consists of two mass spectrometers and a COmetary Pressure Sensor (COPS). The two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time of Flight (RTOF) complement each other with high mass resolution (e.g to resolve 13C from CH), high dynamic range (to detect low abundant isotopes and species), high mass range (to detect organics), and high time resolution. ROSINA is designed to measure the neutral gas and plasma composition in the coma of 67P/Churyumov-Gerasimenko in addition to the physical properties of the neutral component of the coma. For the first time, a comet can be observed in situ from its early activity towards and after perihelion. Little is known about what drives initial cometary activity very far from the Sun. Remote sensing observations to date are highly constrained to a limited number of a few bright comets (e.g. Hale-Bopp) and a limited number of species. Rosetta provides the first measurements of the early activity of a comet in situ and detected the first cometary molecules early August. We will focus on early activity of cometary species from the high resolution mass spectrometer ROSINA/DFMS.

IL-1 or TNF receptor gene deletion delays onset of encephalopathy and attenuates brain edema in experimental acute liver failure.

PubMed

Bémeur, Chantal; Qu, Hong; Desjardins, Paul; Butterworth, Roger F

2010-01-01

Previous reports suggested that brain-derived proinflammatory cytokines are involved in the pathogenesis of hepatic encephalopathy (HE) and brain edema in acute liver failure (ALF). To further address this issue, expression of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) mRNAs were measured in the brains of mice with acute liver failure resulting from exposure to azoxymethane. In addition, time to severe encephalopathy (coma) was assessed in mice lacking genes coding for interferon-gamma, the tumor necrosis factor receptor-1 or the interleukin-1 type 1 receptor. Interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma expression were quantified using RT-PCR. Significant increases in interleukin-1beta and tumor necrosis factor-alpha mRNA were observed in the frontal cortex of azoxymethane-treated wild-type mice at coma stages of encephalopathy. Interferon-gamma, however, could not be detected in the brains of these animals. Onset of severe encephalopathy (coma) and brain edema in ALF mice were significantly delayed in interleukin-1 type 1 receptor or tumor necrosis factor receptor-1 knockout mice. Deletion of the interferon-gamma gene, on the other hand, had no significative effect on the neurological status or brain water content of acute liver failure mice. These results demonstrate that toxic liver injury resulting from exposure to azoxymethane is associated with selective induction of proinflammatory cytokines in the brain and that deletion of tumor necrosis factor receptor-1 or interlukin-1 type 1 receptor delays the onset of coma and brain edema in this model of acute liver failure. These findings further support a role for selective brain-derived cytokines in the pathogenesis of the cerebral complications in acute liver failure and suggest that anti-inflammatory strategies could be beneficial in their prevention. Copyright 2009 Elsevier Ltd. All rights reserved.

Investigation relative to the Roentgen Satellite (ROSAT)

NASA Technical Reports Server (NTRS)

Elvis, Martin S.; Primini, Francis A.; Fabbiano, Guiseppina; Harris, Daniel E.; Jones-Foreman, Christine; Trinchieri, Ginevra; Golub, Leon; Bookbinder, Jay; Seward, Frederick D.; Zombeck, Martin V.

1994-01-01

Reports include: High Resolution Observations of the Central Region of M31; The X-ray Emission of Low-X-ray-Luminosity Early-Type Galaxies: Gas Versus Compact Sources; Interaction Between Cluster Gas and Radio Features of Cygnus A; Hot Gas and Dark Halos in Early-Type Galaxies; A Gravitational Lens in X-rays - 0957+461; How Massive are Early-Type Galaxies?; Three Crab-Like SNR in the Large Magellanic Cloud; and Soft X-ray Emission from Boundary Layers in Cataclysmic Variables. Papers submitted to the Astrophysical Journal are attached.

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

Kim, Suk; Rey, Soo-Chang; Lisker, Thorsten

We present ultraviolet (UV) color-magnitude relations (CMRs) of early-type dwarf galaxies in the Virgo cluster, based on Galaxy Evolution Explorer (GALEX) UV and Sloan Digital Sky Survey (SDSS) optical imaging data. We find that dwarf lenticular galaxies (dS0s), including peculiar dwarf elliptical galaxies (dEs) with disk substructures and blue centers, show a surprisingly distinct and tight locus separated from that of ordinary dEs, which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. We also find that the UV CMRs of dEsmore » in the outer cluster region are slightly steeper than that of their counterparts in the inner region, due to the existence of faint, blue dEs in the outer region. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. We confirm that the feature of delayed star formation of early-type dwarf galaxies in the Virgo cluster is strongly correlated with their morphology and environment. The observed CMR of dS0s is well matched by models with relatively long delayed star formation. Our results suggest that dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment. In any case, UV photometry provides a powerful tool to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories.« less

Implications for the Origin of Early-type Dwarf Galaxies: A Detailed Look at the Isolated Rotating Early-type Dwarf Galaxy LEDA 2108986 (CG 611), Ramifications for the Fundamental Plane’s {S}_{K}^{2} Kinematic Scaling, and the Spin-Ellipticity Diagram

NASA Astrophysics Data System (ADS)

Graham, Alister W.; Janz, Joachim; Penny, Samantha J.; Chilingarian, Igor V.; Ciambur, Bogdan C.; Forbes, Duncan A.; Davies, Roger L.

2017-05-01

Selected from a sample of nine, isolated, dwarf early-type galaxies (ETGs) with the same range of kinematic properties as dwarf ETGs in clusters, we use LEDA 2108986 (CG 611) to address the nature versus nurture debate regarding the formation of dwarf ETGs. The presence of faint disk structures and rotation within some cluster dwarf ETGs has often been heralded as evidence that they were once late-type spiral or dwarf irregular galaxies prior to experiencing a cluster-induced transformation into an ETG. However, CG 611 also contains significant stellar rotation (≈20 km s-1) over its inner half-light radius ({R}{{e},{maj}}=0.71 kpc), and its stellar structure and kinematics resemble those of cluster ETGs. In addition to hosting a faint young nuclear spiral within a possible intermediate-scale stellar disk, CG 611 has accreted an intermediate-scale, counter-rotating gas disk. It is therefore apparent that dwarf ETGs can be built by accretion events, as opposed to disk-stripping scenarios. We go on to discuss how both dwarf and ordinary ETGs with intermediate-scale disks, whether under (de)construction or not, are not fully represented by the kinematic scaling {S}0.5=\\sqrt{0.5 {V}{rot}2+{σ }2}, and we also introduce a modified spin-ellipticity diagram λ (R)-ɛ (R) with the potential to track galaxies with such disks.

An X-ray method for detecting substructure in galaxy clusters - Application to Perseus, A2256, Centaurus, Coma, and Sersic 40/6

NASA Technical Reports Server (NTRS)

Mohr, Joseph J.; Fabricant, Daniel G.; Geller, Margaret J.

1993-01-01

We use the moments of the X-ray surface brightness distribution to constrain the dynamical state of a galaxy cluster. Using X-ray observations from the Einstein Observatory IPC, we measure the first moment FM, the ellipsoidal orientation angle, and the axial ratio at a sequence of radii in the cluster. We argue that a significant variation in the image centroid FM as a function of radius is evidence for a nonequilibrium feature in the intracluster medium (ICM) density distribution. In simple terms, centroid shifts indicate that the center of mass of the ICM varies with radius. This variation is a tracer of continuing dynamical evolution. For each cluster, we evaluate the significance of variations in the centroid of the IPC image by computing the same statistics on an ensemble of simulated cluster images. In producing these simulated images we include X-ray point source emission, telescope vignetting, Poisson noise, and characteristics of the IPC. Application of this new method to five Abell clusters reveals that the core of each one has significant substructure. In addition, we find significant variations in the orientation angle and the axial ratio for several of the clusters.

Clinical Characteristics of Exacerbation-Prone Adult Asthmatics Identified by Cluster Analysis.

PubMed

Kim, Mi Ae; Shin, Seung Woo; Park, Jong Sook; Uh, Soo Taek; Chang, Hun Soo; Bae, Da Jeong; Cho, You Sook; Park, Hae Sim; Yoon, Ho Joo; Choi, Byoung Whui; Kim, Yong Hoon; Park, Choon Sik

2017-11-01

Asthma is a heterogeneous disease characterized by various types of airway inflammation and obstruction. Therefore, it is classified into several subphenotypes, such as early-onset atopic, obese non-eosinophilic, benign, and eosinophilic asthma, using cluster analysis. A number of asthmatics frequently experience exacerbation over a long-term follow-up period, but the exacerbation-prone subphenotype has rarely been evaluated by cluster analysis. This prompted us to identify clusters reflecting asthma exacerbation. A uniform cluster analysis method was applied to 259 adult asthmatics who were regularly followed-up for over 1 year using 12 variables, selected on the basis of their contribution to asthma phenotypes. After clustering, clinical profiles and exacerbation rates during follow-up were compared among the clusters. Four subphenotypes were identified: cluster 1 was comprised of patients with early-onset atopic asthma with preserved lung function, cluster 2 late-onset non-atopic asthma with impaired lung function, cluster 3 early-onset atopic asthma with severely impaired lung function, and cluster 4 late-onset non-atopic asthma with well-preserved lung function. The patients in clusters 2 and 3 were identified as exacerbation-prone asthmatics, showing a higher risk of asthma exacerbation. Two different phenotypes of exacerbation-prone asthma were identified among Korean asthmatics using cluster analysis; both were characterized by impaired lung function, but the age at asthma onset and atopic status were different between the two. Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease

Subtype-specific differentiation of cardiac pacemaker cell clusters from human induced pluripotent stem cells.

PubMed

Schweizer, Patrick A; Darche, Fabrice F; Ullrich, Nina D; Geschwill, Pascal; Greber, Boris; Rivinius, Rasmus; Seyler, Claudia; Müller-Decker, Karin; Draguhn, Andreas; Utikal, Jochen; Koenen, Michael; Katus, Hugo A; Thomas, Dierk

2017-10-16

Human induced pluripotent stem cells (hiPSC) harbor the potential to differentiate into diverse cardiac cell types. Previous experimental efforts were primarily directed at the generation of hiPSC-derived cells with ventricular cardiomyocyte characteristics. Aiming at a straightforward approach for pacemaker cell modeling and replacement, we sought to selectively differentiate cells with nodal-type properties. hiPSC were differentiated into spontaneously beating clusters by co-culturing with visceral endoderm-like cells in a serum-free medium. Subsequent culturing in a specified fetal bovine serum (FBS)-enriched cell medium produced a pacemaker-type phenotype that was studied in detail using quantitative real-time polymerase chain reaction (qRT-PCR), immunocytochemistry, and patch-clamp electrophysiology. Further investigations comprised pharmacological stimulations and co-culturing with neonatal cardiomyocytes. hiPSC co-cultured in a serum-free medium with the visceral endoderm-like cell line END-2 produced spontaneously beating clusters after 10-12 days of culture. The pacemaker-specific genes HCN4, TBX3, and TBX18 were abundantly expressed at this early developmental stage, while levels of sarcomeric gene products remained low. We observed that working-type cardiomyogenic differentiation can be suppressed by transfer of early clusters into a FBS-enriched cell medium immediately after beating onset. After 6 weeks under these conditions, sinoatrial node (SAN) hallmark genes remained at high levels, while working-type myocardial transcripts (NKX2.5, TBX5) were low. Clusters were characterized by regular activity and robust beating rates (70-90 beats/min) and were triggered by spontaneous Ca 2+ transients recapitulating calcium clock properties of genuine pacemaker cells. They were responsive to adrenergic/cholinergic stimulation and able to pace neonatal rat ventricular myocytes in co-culture experiments. Action potential (AP) measurements of cells individualized from clusters exhibited nodal-type (63.4%) and atrial-type (36.6%) AP morphologies, while ventricular AP configurations were not observed. We provide a novel culture media-based, transgene-free approach for targeted generation of hiPSC-derived pacemaker-type cells that grow in clusters and offer the potential for disease modeling, drug testing, and individualized cell-based replacement therapy of the SAN.

[Thyroid emergencies : Thyroid storm and myxedema coma].

PubMed

Spitzweg, C; Reincke, M; Gärtner, R

2017-10-01

Thyroid emergencies are rare life-threatening endocrine conditions resulting from either decompensated thyrotoxicosis (thyroid storm) or severe thyroid hormone deficiency (myxedema coma). Both conditions develop out of a long-standing undiagnosed or untreated hyper- or hypothyroidism, respectively, precipitated by an acute stress-associated event, such as infection, trauma, or surgery. Cardinal features of thyroid storm are myasthenia, cardiovascular symptoms, in particular tachycardia, as well as hyperthermia and central nervous system dysfunction. The diagnosis is made based on clinical criteria only as thyroid hormone measurements do not differentiate between thyroid storm and uncomplicated hyperthyroidism. In addition to critical care measures therapy focusses on inhibition of thyroid hormone synthesis and secretion (antithyroid drugs, perchlorate, Lugol's solution, cholestyramine, thyroidectomy) as well as inhibition of thyroid hormone effects in the periphery (β-blocker, glucocorticoids).Cardinal symptoms of myxedema coma are hypothermia, decreased mental status, and hypoventilation with risk of pneumonia and hyponatremia. The diagnosis is also purely based on clinical criteria as measurements of thyroid hormone levels do not differ between uncomplicated severe hypothyroidism and myxedema coma. In addition to substitution of thyroid hormones and glucocorticoids, therapy focusses on critical care measures to treat hypoventilation and hypercapnia, correction of hyponatremia and hypothermia.Survival of both thyroid emergencies can only be optimized by early diagnosis based on clinical criteria and prompt initiation of multimodal therapy including supportive measures and treatment of the precipitating event.

Morphology and Dynamics of Jets of Comet 67P Churyumov-Gerasimenko: Early Phase Development

NASA Astrophysics Data System (ADS)

Lin, Zhong-Yi; Ip, Wing-Huen; Lai, Ian-Lin; Lee, Jui-Chi; Pajola, Maurizio; Lara, Luisa; Gutierrez, Pedro; Rodrigo, Rafael; Bodewits, Dennis; A'Hearn, Mike; Vincent, Jean-Baptiste; Agarwal, Jessica; Keller, Uwe; Mottola, Stefano; Bertini, Ivano; Lowry, Stephen; Rozek, Agata; Liao, Ying; Rosetta Osiris Coi Team

2015-04-01

The scientific camera, OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System), onboard the Rosetta spacecraft comprises a Narrow Angle Camera (NAC) for nucleus surface and dust studies and a Wide Angle Camera (WAC) for the wide field of dust and gas coma investigations. The dynamical behavior of jets in the dust coma continuously monitored by using dust filters from the arrival at the comet (August 2014) throughout the mapping phase (Oct. 2014) is described here. The analysis will cover the study of the time variability of jets, the source regions of these jets, the excess brightness of jets relative to the averaged coma brightness, and the brightness distribution of dust jets along the projected distance. The jets detected between August and September originated mostly from the neck region (Hapi). Morphological changes appeared over a time scale of several days in September. The brightness slope of the dust jets is much steeper than the background coma. This might be related to the sublimation or fragmentation of the emitted dust grains. Inter-comparison with results from other experiments will be necessary to understand the difference between the dust emitted from Hapi and those from the head and the body of the nucleus surface. The physical properties of the Hapi jets will be compared to dust jets (and their source regions) to emerge as comet 67P moves around the perihelion.

Photometry of the comet 2060 Chiron

NASA Technical Reports Server (NTRS)

Buratti, Bonnie J.; Marcialis, Robert L.; Dunbar, R. Scott

1991-01-01

The comet 2060 Chiron has proven to be an interesting and enigmatic object. Situated between the orbits of Saturn and Uranus, it was originally classified as the most distant asteroid. It began to show cometary behavior in 1987 by increasing a full magnitude in brightness and developing a coma; there is evidence also for similar earlier outbursts. A thorough study of Chiron is important for two reasons: (1) it is a transition object defining the relationship between comets, asteroids, and meteorites; and (2) a full description of its changes in brightness - particularly on time scale of hours - will provide an empirical foundation for understanding the physical mechanisms (including outgassing, sublimation of volatiles, and even significant mass ejections) driving the evolution of comets. Short term outbursts were observed in early 1989, and a rapid decrease in brightness of Chiron's coma was observed in 1990 in the V and R filters. Also, a rotational lightcurve was detected of the nucleus with an amplitude only 1/4 that observed in its quiescent state: this fact indicates the increased importance of the optically thin coma to the observed brightness.

Gait and Glasgow Coma Scale scores can predict functional recovery in patients with traumatic brain injury☆

PubMed Central

Bilgin, Sevil; Guclu-Gunduz, Arzu; Oruckaptan, Hakan; Kose, Nezire; Celik, Bülent

2012-01-01

Fifty-one patients with mild (n = 14), moderate (n = 10) and severe traumatic brain injury (n = 27) received early rehabilitation. Level of consciousness was evaluated using the Glasgow Coma Score. Functional level was determined using the Glasgow Outcome Score, whilst mobility was evaluated using the Mobility Scale for Acute Stroke. Activities of daily living were assessed using the Barthel Index. Following Bobath neurodevelopmental therapy, the level of consciousness was significantly improved in patients with moderate and severe traumatic brain injury, but was not greatly influenced in patients with mild traumatic brain injury. Mobility and functional level were significantly improved in patients with mild, moderate and severe traumatic brain injury. Gait recovery was more obvious in patients with mild traumatic brain injury than in patients with moderate and severe traumatic brain injury. Activities of daily living showed an improvement but this was insignificant except for patients with severe traumatic brain injury. Nevertheless, complete recovery was not acquired at discharge. Multiple regression analysis showed that gait and Glasgow Coma Scale scores can be considered predictors of functional outcomes following traumatic brain injury. PMID:25624828

Central diabetes insipidus in pediatric severe traumatic brain injury.

PubMed

Alharfi, Ibrahim M; Stewart, Tanya Charyk; Foster, Jennifer; Morrison, Gavin C; Fraser, Douglas D

2013-02-01

To determine the occurrence rate of central diabetes insipidus in pediatric patients with severe traumatic brain injury and to describe the clinical, injury, biochemical, imaging, and intervention variables associated with mortality. Retrospective chart and imaging review. Children's Hospital, level 1 trauma center. Severely injured (Injury Severity Score ≥ 12) pediatric trauma patients (>1 month and <18 yr) with severe traumatic brain injury (presedation Glasgow Coma Scale ≤ 8 and head Maximum Abbreviated Injury Scale ≥ 4) that developed acute central diabetes insipidus between January 2000 and December 2011. Of 818 severely injured trauma patients, 180 had severe traumatic brain injury with an overall mortality rate of 27.2%. Thirty-two of the severe traumatic brain injury patients developed acute central diabetes insipidus that responded to desamino-8-D-arginine vasopressin and/or vasopressin infusion, providing an occurrence rate of 18%. At the time of central diabetes insipidus diagnosis, median urine output and serum sodium were 6.8 ml/kg/hr (interquartile range = 5-11) and 154 mmol/L (interquartile range = 149-159), respectively. The mortality rate of central diabetes insipidus patients was 87.5%, with 71.4% declared brain dead after central diabetes insipidus diagnosis. Early central diabetes insipidus onset, within the first 2 days of severe traumatic brain injury, was strongly associated with mortality (p < 0.001), as were a lower presedation Glasgow Coma Scale (p = 0.03), a lower motor Glasgow Coma Scale (p = 0.01), an occurrence of fixed pupils (p = 0.04), and a prolonged partial thromboplastin time (p = 0.04). Cerebral edema on the initial computed tomography, obtained in the first 24 hrs after injury, was the only imaging finding associated with death (p = 0.002). Survivors of central diabetes insipidus were more likely to have intracranial pressure monitoring (p = 0.03), have thiopental administered to induce coma (p = 0.04) and have received a decompressive craniectomy for elevated intracranial pressure (p = 0.04). The incidence of central diabetes insipidus in pediatric patients with severe traumatic brain injury is 18%. Mortality was associated with early central diabetes insipidus onset and cerebral edema on head computed tomography. Central diabetes insipidus nonsurvivors were less likely to have received intracranial pressure monitoring, thiopental coma and decompressive craniectomy.

2010 Aerospace Medical Certification Statistical Handbook

DTIC Science & Technology

2012-02-01

type, hysterical- dissociative type, phobic, neurasthenic, depersonalization, hypochondriacal, adjustment disorder and other neurosis 12,178 2.03...Murmur – includes functional or physiological 10,301 1.72 Traumatic brain injury, concussion, amnesia , coma (30 minutes or more), loss of memory 10,197

The Geometry and Origin of Ultra-diffuse Ghost Galaxies

NASA Astrophysics Data System (ADS)

Burkert, A.

2017-04-01

The geometry and intrinsic ellipticity distribution of ultra-diffuse galaxies (UDG) is determined from the line-of-sight distribution of axial ratios q of a large sample of UDGs, detected by Koda et al. in the Coma cluster. With high significance, the data rules out an oblate, disk-like geometry, characterized by major axes a = b > c. The data is, however, in good agreement with prolate shapes, corresponding to a = b < c. This indicates that UDGs are not thickened, rotating, axisymmetric disks, puffed up by violent processes. Instead, they are anisotropic elongated cigar- or bar-like structures, similar to the prolate dwarf spheroidal galaxy population of the Local Group. The intrinsic distribution of axial ratios of the Coma UDGs is flat in the range of 0.4 ≤ a/c ≤ 0.9 with a mean value of < a/c> =0.65+/- 0.14. This might provide important constraints for theoretical models of their origin. Formation scenarios that could explain the extended prolate nature of UDGs are discussed.

A revised catalog of CfA galaxy groups in the Virgo/Great Attractor flow field

NASA Technical Reports Server (NTRS)

Nolthenius, Richard

1993-01-01

A new identification of groups and clusters in the CfAl Catalog of Huchra, et al. (1983) is presented, using a percolation algorithm to identify density enhancements. The procedure differs from that of the original Geller and Huchra (1983; GH) catalog in several important respects; galaxy distances are calculated from the Virgo-Great Attractor flow model of Faber and Burnstein (1988), the adopted distance linkage criteria is only approx. 1/4 as large as in the Geller and Huchra catalog, the sky link relation is taken from Nolthenius and White (1987), correction for interstellar extinction is included, and 'by-hand' adjustments to group memberships are made in the complex regions of Virgo/Coma I/Ursa Major and Coma/A1367 (to allow for varying group velocity dispersions and to trim unphysical 'spider arms'). Since flow model distances are poorly determined in these same regions, available distances from the IR Tully-Fisher planetary nebula luminosity function and surface brightness resolution methods are adopted if possible.

Hyperosmolar nonketotic coma precipitated by lithium-induced nephrogenic diabetes insipidus.

PubMed Central

Azam, H.; Newton, R. W.; Morris, A. D.; Thompson, C. J.

1998-01-01

A 45-year-old man, with a 10-year history of manic depression treated with lithium, was admitted with hyperosmolar, nonketotic coma. He gave a five-year history of polyuria and polydipsia, during which time urinalysis had been negative for glucose. After recovery from hyperglycaemia, he remained polyuric despite normal blood glucose concentrations; water deprivation testing indicated nephrogenic diabetes insipidus, likely to be lithium-induced. We hypothesize that when this man developed type 2 diabetes, chronic polyuria due to nephrogenic diabetes insipidus was sufficient to precipitate hyperosmolar dehydration. PMID:9538487

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

Goudfrooij, Paul, E-mail: goudfroo@stsci.edu

We study mass functions of globular clusters derived from Hubble Space Telescope/Advanced Camera for Surveys images of the early-type merger remnant galaxy NGC 1316, which hosts a significant population of metal-rich globular clusters of intermediate age ({approx}3 Gyr). For the old, metal-poor ({sup b}lue{sup )} clusters, the peak mass of the mass function M{sub p} increases with internal half-mass density {rho}{sub h} as M{sub p}{proportional_to}{rho}{sub h}{sup 0.44}, whereas it stays approximately constant with galactocentric distance R{sub gal}. The mass functions of these clusters are consistent with a simple scenario in which they formed with a Schechter initial mass function andmore » evolved subsequently by internal two-body relaxation. For the intermediate-age population of metal-rich ({sup r}ed{sup )} clusters, the faint end of the previously reported power-law luminosity function of the clusters with R{sub gal} > 9 kpc is due to many of those clusters having radii larger than the theoretical maximum value imposed by the tidal field of NGC 1316 at their R{sub gal}. This renders disruption by two-body relaxation ineffective. Only a few such diffuse clusters are found in the inner regions of NGC 1316. Completeness tests indicate that this is a physical effect. Using comparisons with star clusters in other galaxies and cluster disruption calculations using published models, we hypothesize that most red clusters in the low-{rho}{sub h} tail of the initial distribution have already been destroyed in the inner regions of NGC 1316 by tidal shocking, and that several remaining low-{rho}{sub h} clusters will evolve dynamically to become similar to 'faint fuzzies' that exist in several lenticular galaxies. Finally, we discuss the nature of diffuse red clusters in early-type galaxies.« less

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

Van den Bergh, Sidney

It is widely believed that lenticular (S0) galaxies were initially spirals from which the gas has been removed by interactions with hot cluster gas, or by ram pressure stripping of cool gas from spirals that are orbiting within rich clusters of galaxies. However, problems with this interpretation are that (1) some lenticulars, such as NGC 3115, are isolated field galaxies rather than cluster members. (2) The distribution of flattening values of S0 galaxies in clusters, in groups, and in the field are statistically indistinguishable. This is surprising because one might have expected most of the progenitors of field S0 galaxiesmore » to have been flattened late-type galaxies, whereas lenticulars in clusters are thought to have mostly been derived from bulge-dominated early-type galaxies. (3) It should be hardest for ram pressure to strip massive luminous galaxies with deep potential wells. However, no statistically significant differences are seen between the luminosity distributions of early-type Shapley-Ames galaxies in clusters, groups, and in the field. (4) Finally both ram pressure stripping and evaporation by hot intracluster gas would be most efficient in rich clusters. However, the small number of available data in the Shapley-Ames sample appears to show no statistically significant differences between the relative frequencies of dust-poor S0{sub 1} and dust-rich S0{sub 3} galaxies in clusters, groups, and in the field. It is tentatively concluded that ram pressure stripping and heating by intracluster gas, may not be the only evolutionary channels that lead to the formation of lenticular galaxies. It is speculated that gas starvation, or gas ejection by active nuclei, may have played a major role in the formation of a significant fraction of all S0 galaxies.« less

Rosetta/OSIRIS - Nucleus morphology and activity of comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rickman, Hans; Rodrigo, Rafael; Koschny, Detlef

2015-04-01

ESA's Rosetta mission arrived on August 6, 2014, at target comet 67P/Churyumov-Gerasimenko after 10 years of cruise. OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) is the scientific imaging system onboard Rosetta. It comprises a Narrow Angle Camera (NAC) for nucleus surface and dust studies and a Wide Angle Camera (WAC) for the wide field coma investigations. OSIRIS imaged the nucleus and coma of the comet from the arrival throughout the mapping phase, PHILAE landing, early escort phase and close fly-by. The overview paper will discuss the surface morpholo-gy and activity of the nucleus as seen in gas, dust, and local jets as well as small scale structures in the local topography.

Subacute sclerosing panencephalitis.

PubMed

Garg, Ravindra Kumar

2008-12-01

Subacute sclerosing panencephalitis (SSPE) is a subacute encephalopathy of childhood and young adolescence. Infrequently, SSPE can occur in adults and pregnant women. It is caused by an aberrant measles virus, known as the SSPE virus. SSPE virus differs from wild-type measles viruses in the form of several mutations affecting the viral genome. The matrix gene is most commonly affected by these mutations. The characteristic clinical manifestations of SSPE include behavioral changes, cognitive decline, myoclonic jerks, seizures, abnormalities in vision, bilateral pyramidal signs and coma. Ocular changes may occur in up to 50% of patients. The most characteristic ophthalmological lesion is necrotizing retinitis. Cortical blindness can be the early feature of SSPE. The diagnosis of SSPE is often difficult in the early stages. In a typical case diagnosis is based on clinical, electroencephalographic, and cerebrospinal fluid findings. At present, there is no effective treatment to completely cure SSPE. Oral isoprinosine and intrathecal or intraventricular alpha-interferon may prolong survival to some extent. Immunization against measles is currently the most effective strategy against SSPE.

Spectroscopic studies of the molecular parentage of radical species in cometary comae

NASA Astrophysics Data System (ADS)

Lewis, Benjamin; Pierce, Donna; Cochran, Anita

2015-11-01

We have observed several comets using an integral-field unit spectrograph (the George and Cynthia Mitchell Spectrograph) on the 2.7m Harlan J. Smith telescope at McDonald Observatory. Full-coma spectroscopic images were obtained for various radical species (C2, C3, CH, CN, NH2). By constructing azimuthal average profiles from the full-coma spectroscopic images we can test Haser model parameters with our observations. The Haser model was used to determine production rates and possible parent lifetimes that would be consistent with the model. By iterating through a large range of possible parents lifetimes, we can see what range of values in which the Haser model is consistent with observations. Also, this type of analysis gives us perspective on how sensitive the model's fit quality is to changes in parent lifetimes. Here, we present the work completed to date, and we compare our results to other comet taxonomic surveys.

Comment on “Modeling of opposition effects with ensembles of clusters: Interplay of various scattering mechanisms” by Elena V. Petrova, Victor P. Tishkovets, Klaus Jockers, 2007 [Icarus 188, 233 245

NASA Astrophysics Data System (ADS)

Shkuratov, Yuriy G.; Zubko, Evgenij S.

2008-04-01

We show that the mechanism called "near-field effect" [e.g., Petrova, E.V., Tishkovets, V.P., Jockers, K., 2007. Icarus 188, 233-245], which is used to explain wide-phase-angle negative polarization branch observed for planetary regoliths and cometary comas, is not realistic as it contradicts laboratory experiments and results of modeling with discrete dipole approximation calculations.

2011 Aerospace Medical Certification Statistical Handbook

DTIC Science & Technology

2013-01-01

reconstruction§ 14,769 2.48 Asthma 12,777 2.15 Neuroses – hysterical, hysterical-conversion type, hysterical- dissociative type, phobic, neurasthenic...functional or physiological 10,086 1.70 Traumatic brain injury, concussion, amnesia , coma (30 minutes or more), loss of memory 10,010 1.68 * Excludes

The Three Sources of Gas in the Comae of Comets

NASA Technical Reports Server (NTRS)

Huebner, W. F.

1995-01-01

Surface water ice on a comet nucleus is the major source of coma gas. Dust, entrained by coma gas, fragments and vaporizes, forming a second, distributed source of coma gas constituents. Ice species more volatile than water ice below the surface of the nucleus are a third source of coma gas. Vapors from these ices, produced by heat penetrating into the nucleus, diffuse through pores outward into the coma. The second and third sources provide minor, but sometimes easily detectible, gaseous species in the coma. We present mixing ratios of observed minor coma constituents relative to water vapor as a function of heliocentric and cometocentric distances and compare these ratios with model predictions, assuming the sources of the minor species are either coma dust or volatile ices in the nucleus.

Mutation Clusters from Cancer Exome.

PubMed

Kakushadze, Zura; Yu, Willie

2017-08-15

We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

Mutation Clusters from Cancer Exome

PubMed Central

Kakushadze, Zura; Yu, Willie

2017-01-01

We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development. PMID:28809811

Relationship between solitary pulmonary nodule lung cancer and CT image features based on gradual clustering

NASA Astrophysics Data System (ADS)

Zhang, Weipeng

2017-06-01

The relationship between the medical characteristics of lung cancers and computer tomography (CT) images are explored so as to improve the early diagnosis rate of lung cancers. This research collected CT images of patients with solitary pulmonary nodule lung cancer, and used gradual clustering methodology to classify them. Preliminary classifications were made, followed by continuous modification and iteration to determine the optimal condensation point, until iteration stability was achieved. Reasonable classification results were obtained. the clustering results fell into 3 categories. The first type of patients was mostly female, with ages between 50 and 65 years. CT images of solitary pulmonary nodule lung cancer for this group contain complete lobulation and burr, with pleural indentation; The second type of patients was mostly male with ages between 50 and 80 years. CT images of solitary pulmonary nodule lung cancer for this group contain complete lobulation and burr, but with no pleural indentation; The third type of patients was also mostly male with ages between 50 and 80 years. CT images for this group showed no abnormalities. the application of gradual clustering methodology can scientifically classify CT image features of patients with lung cancer in the initial lesion stage. These findings provide the basis for early detection and treatment of malignant lesions in patients with lung cancer.

Revealing the origin of the cold ISM in massive early-type galaxies

NASA Astrophysics Data System (ADS)

Davis, T. A.; Alatalo, K.; Bureau, M.; Young, L.; Blitz, L.; Crocker, A.; Bayet, E.; Bois, M.; Bournaud, F.; Cappellari, M.; Davies, R. L.; Duc, P.-A.; de Zeeuw, P. T.; Emsellem, E.; Falcon-Barroso, J.; Khochfar, S.; Krajnovic, D.; Kuntschner, H.; Lablanche, P.-Y.; McDermid, R. M.; Morganti, R.; Naab, T.; Sarzi, M.; Scott, N.; Serra, P.; Weijmans, A.

2013-07-01

Recently, massive early-type galaxies have shed their red-and-dead moniker, thanks to the discovery that many host residual star formation. As part of the ATLAS-3D project, we have conducted a complete, volume-limited survey of the molecular gas in 260 local early-type galaxies with the IRAM-30m telescope and the CARMA interferometer, in an attempt to understand the fuel powering this star formation. We find that around 22% of early-type galaxies in the local volume host molecular gas reservoirs. This detection rate is independent of galaxy luminosity and environment. Here we focus on how kinematic misalignment measurements and gas-to-dust ratios can be used to put constraints on the origin of the cold ISM in these systems. The origin of the cold ISM seems to depend strongly on environment, with misaligned, dust poor gas (indicative of externally acquired material) being common in the field but completely absent in rich groups and in the Virgo cluster. Very massive galaxies also appear to be devoid of accreted gas. This suggests that in the field mergers and/or cold gas accretion dominate the gas supply, while in clusters internal secular processes become more important. This implies that environment has a strong impact on the cold gas properties of ETGs.

Clinical, Radiologic, and Legal Significance of "Extensor Response" in Posttraumatic Coma.

PubMed

Firsching, Raimund; Woischneck, Dieter; Langejürgen, Alexander; Parreidt, Andreas; Bondar, Imre; Skalej, Martin; Röhl, Friedrich; Voellger, Benjamin

2015-11-01

The timely detection of neurologic deterioration can be critical for the survival of a neurosurgical patient following head injury. Because little reliable evidence is available on the prognostic value of the clinical sign "extensor response" in comatose posttraumatic patients, we investigated the correlation of this clinical sign with outcome and with early radiologic findings from magnetic resonance imaging (MRI). This retrospective analysis of prospectively obtained data included 157 patients who had remained in a coma for a minimum of 24 hours after traumatic brain injury. All patients received a 1.5-T MRI within 10 days (median: 2 days) of the injury. The correlations between clinical findings 12 and 24 hours after the injury-in particular, extensor response and pupillary function, MRI findings, and outcome after 1 year-were investigated. Statistical analysis included contingency tables, Fisher exact test, odds ratios (ORs) with confidence intervals (CIs), and weighted κ values. There were 48 patients with extensor response within the first 24 hours after the injury. Patients with extensor response (World Federation of Neurosurgical Societies coma grade III) statistically were significantly more likely to harbor MRI lesions in the brainstem when compared with patients in a coma who had no further deficiencies (coma grade I; p = 0.0004 by Fisher exact test, OR 10.8 with 95% CI, 2.7-42.5) and patients with unilateral loss of pupil function (coma grade II; p = 0.0187, OR 2.8 with 95% CI, 1.2-6.5). The correlation of brainstem lesions as found by MRI and outcome according to the Glasgow Outcome Scale after 1 year was also highly significant (p ≤ 0.016). The correlation of extensor response and loss of pupil function with an unfavorable outcome and with brainstem lesions revealed by MRI is highly significant. Their sudden onset may be associated with the sudden onset of brainstem dysfunction and should therefore be regarded as one of the most fundamental warning signs in the clinical monitoring of comatose patients. Georg Thieme Verlag KG Stuttgart · New York.

VizieR Online Data Catalog: Spectroscopy of standard stars (Joner+, 2015)

NASA Astrophysics Data System (ADS)

Joner, M. D.; Hintz, E. G.

2016-06-01

Between 2005 and 2015, spectroscopic data were obtained using the 1.2-m McKellar Telescope of the Dominion Astrophysical Observatory (DAO). In total, data were secured on 153 nights using the telescope in robotic mode. Observations were made using the Coude spectrograph with the 3231 grating, which provided 40.9Å/mm. Using the Site4 CCD with 15μm pixels gives 0.614Å/pixel. With 4096 pixels along the dispersion axis, this provided a total coverage of approximately 2500Å. Aligning the grating to give a central wavelength of 5710Å allowed a spectral coverage from 4450 to 6970Å, which provided coverage of both Hα and Hβ. In total we examined 75 field stars (table2), 12 stars from the Coma star cluster (table3), 24 from the Hyades (table4), 17 from the Pleiades (table5), and 8 from NGC 752 (table6). These stars cover a spectral type range from O9 to K2. (5 data files).

The most massive galaxies in clusters are already fully grown at z ˜ 0.5

NASA Astrophysics Data System (ADS)

Oldham, L. J.; Houghton, R. C. W.; Davies, Roger L.

2017-02-01

By constructing scaling relations for galaxies in the massive cluster MACSJ0717.5 at z = 0.545 and comparing with those of Coma, we model the luminosity evolution of the stellar populations and the structural evolution of the galaxies. We calculate magnitudes, surface brightnesses and effective radii using Hubble Space Telescope (HST)/ACS images and velocity dispersions using Gemini/GMOS spectra, and present a catalogue of our measurements for 17 galaxies. We also generate photometric catalogues for ˜3000 galaxies from the HST imaging. With these, we construct the colour-magnitude relation, the Fundamental Plane, the mass-to-light versus mass relation, the mass-size relation and the mass-velocity dispersion relation for both clusters. We present a new, coherent way of modelling these scaling relations simultaneously using a simple physical model in order to infer the evolution in luminosity, size and velocity dispersion as a function of redshift, and show that the data can be fully accounted for with this model. We find that (a) the evolution in size and velocity dispersion undergone by these galaxies between z ˜ 0.5 and z ˜ 0 is mild, with Re(z) ˜ (1 + z)-0.40 ± 0.32 and σ(z) ˜ (1 + z)0.09 ± 0.27, and (b) the stellar populations are old, ˜10 Gyr, with a ˜3 Gyr dispersion in age, and are consistent with evolving purely passively since z ˜ 0.5 with Δ log M/L_B = -0.55_{-0.07}^{+0.15} z. The implication is that these galaxies formed their stars early and subsequently grew dissipationlessly so as to have their mass already in place by z ˜ 0.5, and suggests a dominant role for dry mergers, which may have accelerated the growth in these high-density cluster environments.

Music in disorders of consciousness.

PubMed

Rollnik, Jens D; Altenmüller, Eckart

2014-01-01

This review presents an overview of the use of music therapy in neurological early rehabilitation of patients with coma and other disorders of consciousness (DOC) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). There is evidence that patients suffering from UWS show emotional processing of auditory information, such as listening to speech. Thus, it seems reasonable to believe that music listening-as part of an enriched environment setting-may be of therapeutic value in these patients. There is, however, a considerable lack of evidence. The authors strongly encourage further studies to evaluate the efficacy of music listening in patients with DOC in neurological early rehabilitation. These studies should consider a precise clinical definition and homogeneity of the patient cohort with respect to the quality (coma vs. UWS vs. MCS), duration (rather weeks to months than days) and cause (traumatic vs. non-traumatic) of DOC, a standardized intervention protocol, valid clinical outcome parameters over a longer observation period (weeks to months), monitoring of neurophysiological and vegetative parameters and, if available, neuroimaging to confirm diagnosis and to demonstrate responses and functional changes in the patients' brains.

Music in disorders of consciousness

PubMed Central

Rollnik, Jens D.; Altenmüller, Eckart

2014-01-01

This review presents an overview of the use of music therapy in neurological early rehabilitation of patients with coma and other disorders of consciousness (DOC) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). There is evidence that patients suffering from UWS show emotional processing of auditory information, such as listening to speech. Thus, it seems reasonable to believe that music listening—as part of an enriched environment setting—may be of therapeutic value in these patients. There is, however, a considerable lack of evidence. The authors strongly encourage further studies to evaluate the efficacy of music listening in patients with DOC in neurological early rehabilitation. These studies should consider a precise clinical definition and homogeneity of the patient cohort with respect to the quality (coma vs. UWS vs. MCS), duration (rather weeks to months than days) and cause (traumatic vs. non-traumatic) of DOC, a standardized intervention protocol, valid clinical outcome parameters over a longer observation period (weeks to months), monitoring of neurophysiological and vegetative parameters and, if available, neuroimaging to confirm diagnosis and to demonstrate responses and functional changes in the patients' brains. PMID:25071434

Pixel Color–Magnitude Diagram Analysis of the Brightest Cluster Galaxies in Dynamically Young and Old Clusters Abell 1139 and Abell 2589

NASA Astrophysics Data System (ADS)

Lee, Joon Hyeop; Oh, Sree; Jeong, Hyunjin; Yi, Sukyoung K.; Kyeong, Jaemann; Park, Byeong-Gon

2017-07-01

As a case study to understand the coevolution of Brightest Cluster Galaxies (BCGs) and their host clusters, we investigate the BCGs in dynamically young and old clusters Abell 1139 (A1139) and Abell 2589 (A2589). We analyze the pixel color–magnitude diagrams (pCMDs) using deep g- and r-band images, obtained from the Canada–France–Hawaii Telescope observations. After masking foreground/background objects and smoothing pixels in consideration of the observational seeing size, detailed pCMD features are compared between the two BCGs. (1) Although the overall shapes of the pCMDs are similar to those of typical early-type galaxies, the A2589-BCG tends to have redder mean pixel color and smaller pixel color deviation at given surface brightness than the A1139-BCG. (2) The mean pixel color distribution as a function of pixel surface brightness (pCMD backbone) indicates that the A2589-BCG formed a larger central body (∼2.0 kpc in radius) via major dry mergers at an early epoch than the A1139-BCG (a central body ∼1.3 kpc in radius), whereas they have grown commonly in subsequent minor mergers. (3) The spatial distributions of the pCMD outliers reveal that the A1139-BCG experienced considerable tidal events more recently than the A2589-BCG, whereas the A2589-BCG has an asymmetric compact core, possibly resulting from a major dry merger at an early epoch. (4) The A2589-BCG shows a very large faint-to-bright pixel number ratio, compared to early-type non-BCGs, whereas the ratio for the A1139-BCG is not distinctively large. These results are consistent with the idea that the BCG in the dynamically older cluster (A2589) formed earlier and is better relaxed.

A 17-billion-solar-mass black hole in a group galaxy with a diffuse core.

PubMed

Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J; Greene, Jenny E; Blakeslee, John P; Janish, Ryan

2016-04-21

Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already existed 13 billion years ago. Two possible present-day 'dormant' descendants of this population of 'active' black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall--the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600--a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 billion solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.

Membership and Coronal Activity in the NGC 2232 and Cr 140 Open Clusters

NASA Technical Reports Server (NTRS)

Oliversen, Ronald J. (Technical Monitor); Patten, Brian M.

2004-01-01

Making use of eight archival ROSAT HRI images in the regions of the NGC 2232 and Cr 140, this project's primary focus is to identify X-ray sources and to extract net source counts for these sources in these two open clusters. These X-ray data would be combined with ground-based photometry and spectroscopy in order to identify G, K, and early-M type cluster members. Such membership data are important because, at present, no members later than spectral type approx. F5 are currently known for either cluster. With ages estimated to be approx. 25 Myr and at distances of just approx. 350 pc, the combined late-type membership of the NGC 2232 and Cr 140 clusters would yield an almost unique sample of solar-type stars in the post-T Tauri/pre-main sequence phase of evolution. These stars could be used to assess the level and dispersion of coronal activity levels, as a part of a probe of the importance of magnetic braking and the level of magnetic dynamo activity, for solar-type stars just before they reach the zero-age main sequence.

The effects of hypoglycemic and alcoholic coma on the blood-brain barrier permeability

PubMed Central

Yorulmaz, Hatice; Seker, Fatma Burcu; Oztas, Baria

2011-01-01

In this investigation, the effects of hypoglycemic coma and alcoholic coma on the blood-brain barrier (BBB) permeability have been compared. Female adult Wistar albino rats weighing 180-230 g were divided into three groups: Control group (n=8), Alcoholic Coma Group (n=18), and Hypoglycemic Coma group (n=12). The animals went into coma approximately 3-4 hours after insulin administration and 3-5 minutes after alcohol administration. Evans blue (4mL/kg) was injected intravenously as BBB tracer. It was observed that the alcoholic coma did not significantly increase the BBB permeability in any of the brain regions when compared to control group. Changes in BBB permeability were significantly increased by the hypoglycemic coma in comparison to the control group values (p<0.01). Our findings suggest that hypoglycemic and alcoholic coma have different effects on the BBB permeability depending on the energy metabolism. PMID:21619558

Efficacy of Intravenous Haloperidol on the duration of Delirium and Coma in Critically Ill Patients (Hope-ICU): a Randomised, Placebo-Controlled Trial

PubMed Central

Page, Valerie J; Ely, E Wesley; Gates, Simon; Zhao, Xiao Bei; Alce, Timothy; Shintani, Ayumi; Jackson, Jim; Perkins, Gavin D; McAuley, Daniel F

2016-01-01

Background Delirium is frequently diagnosed in critically ill patients and is associated with poor clinical outcomes. Haloperidol is the most commonly used drug for delirium despite little evidence of its effectiveness. The aim of this study was to establish whether early treatment with haloperidol would decrease the time that survivors of critical illness spent in delirium or in coma. Methods We did this double-blind, placebo-controlled randomised trial in a general adult intensive care unit (ICU). Critically ill patients (≥18 years) needing mechanical ventilation within 72 of admission were enrolled. Patients were randomised (by an independent nurse, in 1:1 ratio, with permuted block size of four and six, using a centralised, secure web-based randomisation service) to receive haloperidol 2·5mgs or 0·9% saline placebo intravenously every 8 h irrespective of coma or delirium status. Study drug was discontinued on ICU discharge, once delirium-free and coma-free for 2 consecutive days, or after a maximum of 14 days treatment, which ever came first. Delirium was assessed using the confusion assessment method - for the ICU (CAM-ICU). The primary outcome was delirium-free and coma-free days, defined as the number of days in the first 14 days after randomisation during which the patient was alive without delirium and not in coma from any cause. Patients who died within the 14-day study period were recorded as having 0 days free of delirium and coma. ICU clinical and research staff and patients were masked to treatment throughout the study. Analyses were by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Registry, number ISRCTN83567338. Findings 142 patients were randomised, 141 were included in the final analysis (71 haloperidol, 70 placebo). Patients in the haloperidol group spent about the same number of days alive, without delirium, and without coma as did patients in the placebo group (median 5 days [IQR 0-10] vs 6 days [0-11] days; p= 0·53). The most common adverse events were oversedation (11 patients in the haloperidol group vs. six in the placebo) and QTc prolongation (seven in haloperidol group and six in the placebo group). No patient had a serious adverse event related to study drug. Interpretation These results do not support the hypothesis that haloperidol modifies duration of delirium in critically ill patients. Although haloperidol can be used safely in this population of patients, pending the results of trials in progress, the use of intravenous haloperidol should be reserved for the short-term management of acute agitation. Funding National Institute for Health Research PMID:24461612

Effect of intravenous haloperidol on the duration of delirium and coma in critically ill patients (Hope-ICU): a randomised, double-blind, placebo-controlled trial.

PubMed

Page, Valerie J; Ely, E Wesley; Gates, Simon; Zhao, Xiao Bei; Alce, Timothy; Shintani, Ayumi; Jackson, Jim; Perkins, Gavin D; McAuley, Daniel F

2013-09-01

Delirium is frequently diagnosed in critically ill patients and is associated with poor clinical outcomes. Haloperidol is the most commonly used drug for delirium despite little evidence of its effectiveness. The aim of this study was to establish whether early treatment with haloperidol would decrease the time that survivors of critical illness spent in delirium or coma. We did this double-blind, placebo-controlled randomised trial in a general adult intensive care unit (ICU). Critically ill patients (≥18 years) needing mechanical ventilation within 72 h of admission were enrolled. Patients were randomised (by an independent nurse, in 1:1 ratio, with permuted block size of four and six, using a centralised, secure web-based randomisation service) to receive haloperidol 2.5 mg or 0.9% saline placebo intravenously every 8 h, irrespective of coma or delirium status. Study drug was discontinued on ICU discharge, once delirium-free and coma-free for 2 consecutive days, or after a maximum of 14 days of treatment, whichever came first. Delirium was assessed using the confusion assessment method for the ICU (CAM-ICU). The primary outcome was delirium-free and coma-free days, defined as the number of days in the first 14 days after randomisation during which the patient was alive without delirium and not in coma from any cause. Patients who died within the 14 day study period were recorded as having 0 days free of delirium and coma. ICU clinical and research staff and patients were masked to treatment throughout the study. Analyses were by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Registry, number ISRCTN83567338. 142 patients were randomised, 141 were included in the final analysis (71 haloperidol, 70 placebo). Patients in the haloperidol group spent about the same number of days alive, without delirium, and without coma as did patients in the placebo group (median 5 days [IQR 0-10] vs 6 days [0-11] days; p=0.53). The most common adverse events were oversedation (11 patients in the haloperidol group vs six in the placebo group) and QTc prolongation (seven patients in the haloperidol group vs six in the placebo group). No patient had a serious adverse event related to the study drug. These results do not support the hypothesis that haloperidol modifies duration of delirium in critically ill patients. Although haloperidol can be used safely in this population of patients, pending the results of trials in progress, the use of intravenous haloperidol should be reserved for short-term management of acute agitation. National Institute for Health Research. Copyright © 2013 Elsevier Ltd. All rights reserved.

Illuminating the clinical significance of alexithymia subtypes: A cluster analysis of alexithymic traits and psychiatric symptoms.

PubMed

Kajanoja, J; Scheinin, N M; Karlsson, L; Karlsson, H; Karukivi, M

2017-06-01

Alexithymia is a personality construct involving difficulties identifying and verbalizing feelings, and an externally oriented thinking style. There is preliminary evidence for alexithymia subtypes that may carry different risk profiles for psychiatric illness. The aim of this study was to gain support for the existence of alexithymia subtypes and further characterize their clinical relevance. To identify possible subtypes, a cluster analysis was conducted for individuals with high alexithymic traits (N=113). Current depressive and anxiety symptoms, self-reported psychiatric medical history, and self-reported early life adversity were compared between subtypes. The cluster analysis was replicated with the low (N=2471) and moderate (N=290) alexithymia groups. We identified two alexithymia subtypes. Compared to type A, type B alexithymia was associated with higher levels of difficulties in identifying feelings, and was more strongly associated with current depressive (Cohen's d=0.77, p<0.001) and anxiety symptoms (Cohen's d=0.82, p<0.001), and self-reported early life adversity (Cohen's d 0.42, p=0.048). Compared to type A, type B alexithymia was also associated with a higher prevalence of self-reported diagnosis of major depressive- (30.2% vs. 8.3%) and anxiety disorder (18.9% vs. 3.3%). The results of this study support the hypothesis of alexithymia subtypes, and add support to the growing evidence showing that alexithymia is likely a heterogeneous and dimensional phenomenon. The subtype (type B) with most pronounced difficulties in identifying feelings may be associated with a higher risk for psychiatric illness compared to type A alexithymia, and may exhibit a more severe history of early life adversity. Copyright © 2017 Elsevier Inc. All rights reserved.

Globular cluster systems as tracers of environmental effects on Virgo early-type dwarfs

NASA Astrophysics Data System (ADS)

Sánchez-Janssen, R.; Aguerri, J. A. L.

2012-08-01

Early-type dwarfs (dEs) are by far the most abundant galaxy population in nearby clusters. Whether these objects are primordial, or the recent end products of the different physical mechanisms that can transform galaxies once they enter these high-density environments, is still a matter of debate. Here we present a novel approach to test these scenarios by comparing the properties of the globular cluster systems (GCSs) of Virgo dEs and their potential progenitors with simple predictions from gravitational and hydrodynamical interaction models. We show that low-mass (M★ ≲ 2 × 108 M⊙) dEs have GCSs consistent with the descendants of gas-stripped late-type dwarfs. On the other hand, higher mass dEs have properties - including the high mass specific frequencies of their GCSs and their concentrated spatial distribution within Virgo - incompatible with a recent, environmentally driven evolution. They mostly comprise nucleated systems, but also dEs with recent star formation and/or disc features. Bright, nucleated dEs appear to be a population that has long resided within the cluster potential well, but have surprisingly managed to retain very rich and spatially extended GCSs - possibly an indication of high total masses. Our analysis does not favour violent evolutionary mechanisms that result in significant stellar mass-losses, but more gentle processes involving gas removal by a combination of internal and external factors, and highlights the relevant role of initial conditions. Additionally, we briefly comment on the origin of luminous cluster S0 galaxies.

Real & Simulated IFU Observations of Low-Mass Early-Type Galaxies: Environmental Influence Probed for Cluster Galaxies

NASA Astrophysics Data System (ADS)

Sybilska, Agnieszka; Łokas, Ewa Luiza; Fouquet, Sylvain

2017-03-01

We combine high-quality IFU data with a new set of numerical simulations to study low-mass early type galaxies (dEs) in dense environments. Our earlier study of dEs in the Virgo cluster has produced the first large-scale maps of kinematic and stellar population properties of dEs in those environments (Ryś et al. 2013, 2014, 2015). A quantitative discrimination between various (trans)formation processes proposed for these objects is, however, a complex issue, requiring a priori assumptions about the progenitors of galaxies we observe and study today. To bridge this gap between observations and theoretical predictions, we use the expertise gained in the IFU data analysis to look ``through the eye of SAURON'' at our new suite of high-resolution N-body simulations of dEs in the Virgo cluster. Mimicking the observers perspective as closely as possible, we can also indicate the existing instrumental and viewer limitations regarding what we are/are not able to detect as observers.

Survey for Ortho-to-Para Abundance Ratios (OPRs) of NH2 in Comets: Revisit to the Meaning of OPRs of Cometary Volatiles

NASA Astrophysics Data System (ADS)

Kawakita, Hideyo; Shinnaka, Yoshiharu; Jehin, Emmanuel; Decock, Alice; Hutsemekers, Damien; Manfroid, Jean

2016-10-01

Since molecules having identical protons can be classified into nuclear-spin isomers (e.g., ortho-H2O and para-H2O for water) and their inter-conversions by radiative and non-destructive collisional processes are believed to be very slow, the ortho-to-para abundance ratios (OPRs) of cometary volatiles such as H2O, NH3 and CH4 in coma have been considered as primordial characters of cometary molecules [1]. Those ratios are usually interpreted as nuclear-spin temperatures although the real meaning of OPRs is in strong debate. Recent progress in laboratory studies about nuclear-spin conversion in gas- and solid-phases [2,3] revealed short-time nuclear-spin conversions for water, and we have to reconsider the interpretation for observed OPRs of cometary volatiles. We have already performed the survey for OPRs of NH2 in more than 20 comets by large aperture telescopes with high-resolution spectrographs (UVES/VLT, HDS/Subaru, etc.) in the optical wavelength region [4]. The observed OPRs of ammonia estimated from OPRs of NH2, cluster around ~1.1 (cf. 1.0 as a high-temperature limit), indicative of ~30 K as nuclear-spin temperatures. We present our latest results for OPRs of cometary NH2 and discuss about the real meaning of OPRs of cometary ammonia, in relation to OPRs of water in cometary coma. Chemical processes in the inner coma may play an important role to achieve un-equilibrated OPRs of cometary volatiles in coma.This work was financially supported by MEXT Supported Program for the Strategic Research Foundation at Private Universities, 2014-2018 (No. S1411028) (HK) and by Graint-in-Aid for JSPS Fellows, 15J10864 (YS).References:[1] Mumma & Charnley, 2011, Annu. Rev. Astro. Astrophys. 49, 471.[2] Hama & Watanabe, 2013, Chem. Rev. 113, 8783.[3] Hama et al., 2008, Science 351, 6268.[4] Shinnaka et al., 2011, ApJ 729, 81.

Homeopathic treatment for prolonged postoperative coma: a case report.

PubMed

Vithoulkas, G; Văcăraș, V; Kavouras, J; Buzoianu, A D; Mărginean, M; Văcăraș, D; Cozma, S

2017-01-01

Coma is the state of unrousable unconsciousness. There are variations in the degree of coma and the findings and signs found on the patient's clinical examination depend on the underlying cause of the disorder. The Glasgow Coma scale evaluates the best motor, verbal and eye answers of the patient. A patient is considered to be in a coma if his Glasgow Coma Scale is below 8 points. The progress that we have made throughout the years has also led to complications that can culminate in a major catastrophe like death, permanent brain damage, coma. A study performed reached the conclusion that prior comorbidity, older age, intraoperative hypotension, and cardiovascular surgery may predispose patients to postoperative coma. The article presents a case of postoperative coma treated successfully with homeopathy. Although a rare complication, postoperative coma is a severe, death-leading condition, causing immense suffering on both the patient and the patient's family. A multidisciplinary and thorough approach is necessary for these patients, but even after a well-conducted therapy, this condition leads to the death of the patient.

Homeopathic treatment for prolonged postoperative coma: a case report

PubMed Central

Vithoulkas, G; Văcăraș, V; Kavouras, J; Buzoianu, AD; Mărginean, M; Văcăraș, D; Cozma, S

2017-01-01

Coma is the state of unrousable unconsciousness. There are variations in the degree of coma and the findings and signs found on the patient’s clinical examination depend on the underlying cause of the disorder. The Glasgow Coma scale evaluates the best motor, verbal and eye answers of the patient. A patient is considered to be in a coma if his Glasgow Coma Scale is below 8 points. The progress that we have made throughout the years has also led to complications that can culminate in a major catastrophe like death, permanent brain damage, coma. A study performed reached the conclusion that prior comorbidity, older age, intraoperative hypotension, and cardiovascular surgery may predispose patients to postoperative coma. The article presents a case of postoperative coma treated successfully with homeopathy. Although a rare complication, postoperative coma is a severe, death-leading condition, causing immense suffering on both the patient and the patient’s family. A multidisciplinary and thorough approach is necessary for these patients, but even after a well-conducted therapy, this condition leads to the death of the patient. PMID:28616086

Analysis and Interpretation of Hard X-ray Emission fromthe Bullet Cluster (1E0657-56), the Most Distant Cluster of Galaxies Observed by the RXTE

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

Petrosian, Vahe; /Stanford U., Phys. Dept. /SLAC /Stanford U., Appl. Phys. Dept.; Madejski, Greg

2006-08-16

Evidence for non-thermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons. New windows in the Extreme Ultraviolet and Hard X-ray ranges have provided for more powerful tools for the investigation of this phenomenon. Detection of hard X-rays in the 20 to 100 keV range have been reported from several clusters of galaxies, notably from Coma and others. Based on these earlier observations we identified the relatively high redshift cluster 1E0657-56 (also known as RX J0658-5557) as a good candidate for hard X-ray observations. This cluster, also known as the bullet cluster,more » has many other interesting and unusual features, most notably that it is undergoing a merger, clearly visible in the X-ray images. Here we present results from a successful RXTE observations of this cluster. We summarize past observations and their theoretical interpretation which guided us in the selection process. We describe the new observations and present the constraints we can set on the flux and spectrum of the hard X-rays. Finally we discuss the constraints one can set on the characteristics of accelerated electrons which produce the hard X-rays and the radio radiation.« less

Do We Really Have an Age/H_0 Conflict?

NASA Astrophysics Data System (ADS)

Baum, W. A.

1997-12-01

Two independent methods for estimating the age of the universe can both be linked to the absolute magnitudes of the RR Lyrae stars, one based on stellar evolution in globular clusters and the other based on the Hubble Constant derived from globular clusters as distance indicators. The latter has recently been extracted from HST-WFPC2 data for globular clusters in the Coma Cluster galaxy IC 4051 (Baum et al. 1997, AJ, 113, 1483). If RR Lyrae stars are brighter than we have previously thought, the stellar-evolution age estimate is shortened whereas the Hubble age is increased, so we can ask a very simple question: For what RR Lyrae magnitude zero point would the stellar-evolution age coincide with the Hubble age, and is it a reasonable value? Allowing 1 Gyr for globular clusters to have formed, and assuming a classical Einstein-deSitter universe with Lambda = 0, I find the two ages to coincide if M_V(RR) ~ 0.16[Fe/H] + 0.46, which (among other things) puts the Large Magellanic Cloud at (m-M) = 18.78 +/- 0.17 mag. The implied age of the universe is 11.0 +/- 1.4 Gyr, and the corresponding H_0 = 59 +/- 8 km/s per Mpc.

2 years with comet 67P/Churyumov-Gerasimenko: H2O, CO2, CO as seen by ROSINA RTOF

NASA Astrophysics Data System (ADS)

Hoang, M.; Garnier, P.; Lasue, J.; Reme, H.; Altwegg, K.; Balsiger, H. R.; Bieler, A. M.; Calmonte, U.; Capria, M. T.; Combi, M. R.; De Keyser, J. M.; Fiethe, B.; Fougere, N.; Fuselier, S. A.; Galli, A.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Jäckel, A.; Korth, A.; Mall, U.; Migliorini, A.; Rubin, M.; Sémon, T.; Tzou, C. Y.; Waite, J. H., Jr.; Wurz, P.

2017-12-01

The Rosetta space mission investigated comet 67P/Churyumov-Gerasimenko (67P) over two years from August 2014 to September 2016. Onboard the spacecraft, the ROSINA experiment included two mass spectrometers to derive the composition of neutrals and ions, and a COmet Pressure Sensor (COPS) to monitor the density and velocity of the neutrals in the coma. We will here analyse and discuss data from the Reflectron-type Time-Of-Flight instrument during the comet escort phase. The RTOF mass spectrometer possessed a wide mass range and a high temporal resolution (Balsiger et al., 2007). The analysis of 67P/C-G's coma major molecules over the mission showed strong variability of the comet coma's main volatiles concentrations (H2O, CO2, CO) and their relative abundances. The 2 years long Rosetta mission allowed us to observe the seasonal evolution in the atmosphere of 67P, in particular the change occurring during the equinoxes and at perihelion. In this work, we analyze the asymmetry in the outgassing rate before and after the perihelion (13/08/2015), the evolution of abundance ratios through the whole mission, and in particular the behavior of the very volatile CO molecules. Density maps projected on the surface of 67P demonstrate the evolution of the three main coma species after the outbound equinox. We will present first results of our comet nucleus thermal modelling used to simulate the internal structure and temperature evolution of 67P at characteristic surface areas. These results will be compared with the coma composition measurements obtained by ROSINA.

The Noble Gas Abundances in the Coma of Comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA

NASA Astrophysics Data System (ADS)

Rubin, M.; Altwegg, K.; Balsiger, H. R.; Berthelier, J. J.; Briois, C.; Combi, M. R.; De Keyser, J.; Fiethe, B.; Fuselier, S. A.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Jäckel, A.; Kopp, E.; Korth, A.; Mall, U.; Marty, B.; Mousis, O.; Owen, T.; Reme, H.; Schuhmann, M.; Schroeder, I. R. H. G.; Semon, T.; Tzou, C. Y.; Waite, J. H., Jr.; Wurz, P.

2017-12-01

The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), the mass spectrometer suite on board the European Space Agency's Rosetta mission, was dedicated to the measurement of the volatiles in the coma of comet 67P/Churyumov-Gerasimenko (67P) [1]. Among many other species, ROSINA DFMS, the Double Focusing Mass Spectrometer, detected and quantified the three noble gases argon, krypton, and xenon including their major isotopes [2,3]. Noble gases provide important clues to the physical and chemical conditions during and possibly even before and after the comet's formation in the early solar system. Furthermore, measurements of the isotope ratios provide constraints on the amount of cometary material brought to Earth and its early atmosphere. In this presentation, we will report on the measured coma densities and derived nucleus bulk abundances of these three noble gases and investigate correlations with other volatiles. Furthermore, we will discuss the measured isotope ratios and the implications of these results. AcknowledgementsUoB was funded by the State of Bern, the Swiss National Science Foundation and by the European Space Agency PRODEX Programme. Work at MPS was funded by the Max-Planck Gesellschaft and BMWI (contract 50QP1302), at Southwest Research institute by Jet Propulsion Laboratory (subcontract #1496541 and JPL subcontract to JWH NAS703001TONMO710889), at the University of Michigan by NASA (contract JPL-1266313). This work has been supported through the A*MIDEX project from the French National Research Agency (ANR) (n° ANR-11-IDEX- 0001-02) and by CNES grants at IRAP, LATMOS, LPC2E, LAM, CRPG, by the European Research Council (grant no. 267255 to B. Marty) and at BIRA-IASB by the Belgian Science Policy Office via PRODEX/ROSINA PEA C4000107705. References[1] Balsiger, H., et al., Rosina - Rosetta orbiter spectrometer for ion and neutral analysis. Space Science Reviews. 128, 745-801, 2007. [2] Balsiger, H., et al., Detection of argon in the coma of comet 67P/Churyumov-Gerasimenko. Sci Adv. 1, e1500377, 2015. [3] Marty B., et al., Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere, Science, 356, 1069 - 1072, 2017.

Carbonaceous Components in the Comet Halley Dust

NASA Technical Reports Server (NTRS)

Fomenkova, M. N.; Chang, S.; Mukhin, L. M.

1994-01-01

Cometary grains containing large amounts of carbon and/or organic matter (CHON) were discovered by in situ measurements of comet Halley dust composition during VEGA and GIOTTO flyby missions. In this paper, we report the classification of these cometary, grains by means of cluster analysis, discuss the resulting compositional groups, and compare them with substances observed or hypothesized in meteorites, interplanetary dust particles, and the interstellar medium. Grains dominated by carbon and/or organic matter (CHON grains) represent approx. 22% of the total population of measured cometary dust particles. They, usually contain a minor abundance of rock-forming elements as well. Grains having organic material are relatively more abundant in the vicinity of the nucleus than in the outer regions of the coma, which suggests decomposition of the organics in the coma environment. The majority of comet Halley organic particles are multicomponent mixtures of carbon phases and organic compounds. Possibly, the cometary CHON grains may be related to kerogen material of an interstellar origin in carbonaceous meteorites. Pure carbon grains, hydrocarbons and polymers of cyanopolyynes, and multi-carbon monoxides are present in cometary dust as compositionally simple and distinctive components among a variety of others. There is no clear evidence of significant presence of pure formaldehyde or HCN polymers in Halley dust particles. The diversity of types of cometary organic compounds is consistent with the inter-stellar dust model of comets and probably reflects differences in composition of precursor dust. Preservation of this heterogeneity among submicron particles suggest the gentle formation of cometary, nucleus by aggregation of interstellar dust in the protosolar nebula without complete mixing or chemical homogenization at the submicron level.

Long-Period Planets in Open Clusters and the Evolution of Planetary Systems

NASA Astrophysics Data System (ADS)

Quinn, Samuel N.; White, Russel; Latham, David W.; Stefanik, Robert

2018-01-01

Recent discoveries of giant planets in open clusters confirm that they do form and migrate in relatively dense stellar groups, though overall occurrence rates are not yet well constrained because the small sample of giant planets discovered thus far predominantly have short periods. Moreover, planet formation rates and the architectures of planetary systems in clusters may vary significantly -- e.g., due to intercluster differences in the chemical properties that regulate the growth of planetary embryos or in the stellar space density and binary populations, which can influence the dynamical evolution of planetary systems. Constraints on the population of long-period Jovian planets -- those representing the reservoir from which many hot Jupiters likely form, and which are most vulnerable to intracluster dynamical interactions -- can help quantify how the birth environment affects formation and evolution, particularly through comparison of populations possessing a range of ages and chemical and dynamical properties. From our ongoing RV survey of open clusters, we present the discovery of several long-period planets and candidate substellar companions in the Praesepe, Coma Berenices, and Hyades open clusters. From these discoveries, we improve estimates of giant planet occurrence rates in clusters, and we note that high eccentricities in several of these systems support the prediction that the birth environment helps shape planetary system architectures.

Prediction of cognitive outcome based on the progression of auditory discrimination during coma.

PubMed

Juan, Elsa; De Lucia, Marzia; Tzovara, Athina; Beaud, Valérie; Oddo, Mauro; Clarke, Stephanie; Rossetti, Andrea O

2016-09-01

To date, no clinical test is able to predict cognitive and functional outcome of cardiac arrest survivors. Improvement of auditory discrimination in acute coma indicates survival with high specificity. Whether the degree of this improvement is indicative of recovery remains unknown. Here we investigated if progression of auditory discrimination can predict cognitive and functional outcome. We prospectively recorded electroencephalography responses to auditory stimuli of post-anoxic comatose patients on the first and second day after admission. For each recording, auditory discrimination was quantified and its evolution over the two recordings was used to classify survivors as "predicted" when it increased vs. "other" if not. Cognitive functions were tested on awakening and functional outcome was assessed at 3 months using the Cerebral Performance Categories (CPC) scale. Thirty-two patients were included, 14 "predicted survivors" and 18 "other survivors". "Predicted survivors" were more likely to recover basic cognitive functions shortly after awakening (ability to follow a standardized neuropsychological battery: 86% vs. 44%; p=0.03 (Fisher)) and to show a very good functional outcome at 3 months (CPC 1: 86% vs. 33%; p=0.004 (Fisher)). Moreover, progression of auditory discrimination during coma was strongly correlated with cognitive performance on awakening (phonemic verbal fluency: rs=0.48; p=0.009 (Spearman)). Progression of auditory discrimination during coma provides early indication of future recovery of cognitive functions. The degree of improvement is informative of the degree of functional impairment. If confirmed in a larger cohort, this test would be the first to predict detailed outcome at the single-patient level. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of the Large Scale Environment on the Internal Dynamics of Early-Type Galaxies

NASA Astrophysics Data System (ADS)

Maubon, G.; Prugniel, Ph.

We have studied the population-density relation in very sparse environments, from poor clusters to isolated galaxies, and we find that early-type galaxies with a young stellar population are preferably found in the lowest density environments. We show a marginal indication that this effect is due to an enhancement of the stellar formation independent of the morphological segregation, but we failed to find any effect from the internal dynamics.

UBV and H. beta. photometry of faint early-type stars in Crux and Centaurus

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

Muzzio, J.C.; Feinstein, A.; Orsatti, A.M.

1976-08-01

UBV and H..beta.. photoelectric observations of faint early-type stars in a small region in Crux near the open cluster Hogg 15 and another in Centaurus are presented. The data suggest large absorption in Crux and small absorption in Centaurus. The spread in the distance moduli of the observed stars seems to be in agreement with the view that a spiral arm is seen tangentially near l = 305/sup 0/.

Early Withdrawal Decision-Making in Patients with Coma After Cardiac Arrest: A Qualitative Study of Intensive Care Clinicians.

PubMed

Ong, Charlene J; Dhand, Amar; Diringer, Michael N

2016-10-01

Neurologists are often asked to define prognosis in comatose patients. However, comatose patients following cardiac arrest are usually cared for by cardiologists or intensivists, and it is their approach that will influence decisions regarding withdrawal of life-sustaining interventions (WLSI). We observed that factors leading to these decisions vary across specialties and considered whether they could result in self-fulfilling prophecies and early WLSI. We conducted a hypothesis-generating qualitative study to identify factors used by non-neurologists to define prognosis in these patients and construct an explanatory model for how early WLSI might occur. This was a single-center qualitative study of intensivists caring for cardiac arrest patients with hypoxic-ischemic coma. Thirty attending physicians (n = 16) and fellows (n = 14) from cardiac (n = 8), medical (n = 6), surgical (n = 10), and neuro (n = 6) intensive care units underwent semi-structured interviews. Interview transcripts were analyzed using grounded theory techniques. We found three components of early WLSI among non-neurointensivists: (1) development of fixed negative opinions; (2) early framing of poor clinical pictures to families; and (3) shortened windows for judging recovery potential. In contrast to neurointensivists, non-neurointensivists' negative opinions were frequently driven by patients' lack of consciousness and cardiopulmonary resuscitation circumstances. Both groups were influenced by age and comorbidities. The results demonstrate that factors influencing prognostication differ across specialties. Some differ from those recommended by published guidelines and may lead to self-fulfilling prophecies and early WLSI. Better understanding of this framework would facilitate educational interventions to mitigate this phenomenon and its implications on patient care.

Evolution of Cometary Activity at 67P/Churyumov-Gerasimenko as seen by ROSINA/Rosetta

NASA Astrophysics Data System (ADS)

Jäckel, A.; Altwegg, K.; Balsiger, H.; Calmonte, U.; Gasc, S.; Le Roy, L.; Rubin, M.; Tzou, C. Y.; Wurz, P.; Bieler, A.; Berthelier, J.-J.; Fiethe, B.; Hässig, M.; deKeyser, J.; Mall, U.; Rème, H.

2015-10-01

Since nine months the European Space Agency's spacecraft Rosetta, with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard, is in the comet escort phase. ROSINA is a suite of three instruments, consisting of the COmetary Pressure Sensor (COPS), the Double Focusing Mass Spectrometer (DFMS), and the Reflectron-type Time-Of-Flight (RTOF) mass spectrometer [1]. The two mass spectrometers measure in situ the neutral and ionized volatile material in the coma of comet 67P/Churyumov- Gerasimenko (67P/C-G). With COPS we are able to derive the total gas density, bulk velocities and temperatures of the coma.

Resolution of electroconvulsive therapy refractory major depressive disorder with unintentional hypoglycemic seizure: a case report.

PubMed

Rosenblat, Joshua D; Devarajan, Sivakumaran

2013-09-01

We report a 74-year-old white woman with type 1 diabetes and major depressive disorder refractory to multiple medications who received 15 electroconvulsive therapy treatments with minimal improvement. After an accidental hypoglycemic seizure, the patient's symptoms completely resolved. In conclusion, the present case reveals an instance where electroconvulsive therapy-induced seizures appeared to be minimally effective, whereas a single accidental hypoglycemia-induced seizure was incredibly effective for the resolutions of depressive symptoms. Although this case presents a single efficacious use of accidental insulin coma therapy, the applicability is limited because of the known risks of insulin coma therapy.

NAGD regimen for the coma of drug-related overdose.

PubMed

Rappolt, R T; Gay, G R; Decker, W J; Inaba, D S

1980-07-01

A specific arousal therapy with NAGD (Naloxone, Activated Charcoal, Glucagon, Doxapram) is outlined for victims of drug overdose in comatose and semi-comatose states. Several direct benefits accrue if early awakening or lightening of such patients is safely accomplished. There are: 1) elimination of need for prolonged intubation or tracheostomy; 2) patient's ability to tell which drug(s) were taken; 3) excessively frantic and vigorous supportive treatment is obviated; and 4) the overall hospital stay is shortened. The NAGD regimen has been found to effectively, safely, and predictably reverse coma. Therapy consists of: naloxone 0.8 mg to 1.6 mg intravenously; large-bore orogastric tube instillation of 100 gm to 120 gm activated charcoal slurry; glucagon 1 mg to 2 mg intravenously; and, in selected cases, doxapram 1 mg/kg to 2 mg/kg intravenously.

Neurological prognostication of outcome in patients in coma after cardiac arrest.

PubMed

Rossetti, Andrea O; Rabinstein, Alejandro A; Oddo, Mauro

2016-05-01

Management of coma after cardiac arrest has improved during the past decade, allowing an increasing proportion of patients to survive, thus prognostication has become an integral part of post-resuscitation care. Neurologists are increasingly confronted with raised expectations of next of kin and the necessity to provide early predictions of long-term prognosis. During the past decade, as technology and clinical evidence have evolved, post-cardiac arrest prognostication has moved towards a multimodal paradigm combining clinical examination with additional methods, consisting of electrophysiology, blood biomarkers, and brain imaging, to optimise prognostic accuracy. Prognostication should never be based on a single indicator; although some variables have very low false positive rates for poor outcome, multimodal assessment provides resassurance about the reliability of a prognostic estimate by offering concordant evidence. Copyright © 2016 Elsevier Ltd. All rights reserved.

Incidence, predictors and outcomes of postoperative coma: an observational study of 858,606 patients.

PubMed

Newman, Jessica; Blake, Kathryn; Fennema, Jordan; Harris, David; Shanks, Amy; Avidan, Michael S; Kelz, Max B; Mashour, George A

2013-08-01

Coma is a state of profound unresponsiveness that can occur as a serious perioperative complication. The study of risk factors for, and sequelae of, postoperative coma has been limited due to the rarity of the event. To determine the incidence, risk factors and impact of postoperative coma in a large patient population. Observational study using a prospectively gathered national dataset. Data from 858 606 patients were analysed. The incidence of postoperative coma of more than 24-h duration was identified. Logistic regression was used to identify independent predictors and develop a risk model of postoperative coma in derivation and validation cohorts; 30-day mortality was also analysed. The incidence of postoperative coma was 0.06%. Multivariate analysis revealed the following independent predictors: liver disease, systemic sepsis, age at least 63 years, renal disease, emergency operation, cardiac disease, hypertension, prior neurological disease, diabetes mellitus and BMI 25 to 29.99 kg m (protective). These predictors were incorporated into a risk index classification; odds ratios for postoperative coma increased from 2.5 with one risk factor to 18.4 with three. Coma was associated with 74.2% all-cause mortality; coma associated with cardiac arrest had a 1.9-fold higher mortality. This is the largest study of postoperative coma ever reported and will be useful for determining risk of coma of more than 24 h duration when evaluating an unresponsive patient following surgery. Data on prognosis will aid medical and ethical decision-making for the comatose surgical patient.

Study of crystallization mechanisms of Fe nanoparticle

NASA Astrophysics Data System (ADS)

Kien, P. H.; Trang, G. T. T.; Hung, P. K.

2017-06-01

In this paper, the nanoparticle (NP) Fe was investigated by means of molecular dynamics simulation. The crystallization mechanism was studied through the time evolution of crystal cluster and potential energies of different atom types. The simulation shows that the NP was crystallized into bcc crystal structure when it was annealed at 900 K for long times. At early stage of the annealing, small nuclei form in different places of NP and dissolve for short times. After long times some nuclei form and gather nearby which create the stable clusters in the core of NP. After that the crystal clusters grow in the direction to cover the core and then to spread into the surface of NP. Analyzing the energies of different type atoms, we found that the crystal growth is originated from specific atomic arrangement in the boundary region of crystal clusters.

EFFECT OF ENVIRONMENT ON GALAXIES' MASS-SIZE DISTRIBUTION: UNVEILING THE TRANSITION FROM OUTSIDE-IN TO INSIDE-OUT EVOLUTION

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

Cappellari, Michele

2013-11-20

The distribution of galaxies on the mass-size plane as a function of redshift or environment is a powerful test for galaxy formation models. Here we use integral-field stellar kinematics to interpret the variation of the mass-size distribution in two galaxy samples spanning extreme environmental densities. The samples are both identically and nearly mass-selected (stellar mass M {sub *} ≳ 6 × 10{sup 9} M {sub ☉}) and volume-limited. The first consists of nearby field galaxies from the ATLAS{sup 3D} parent sample. The second consists of galaxies in the Coma Cluster (Abell 1656), one of the densest environments for which good, resolvedmore » spectroscopy can be obtained. The mass-size distribution in the dense environment differs from the field one in two ways: (1) spiral galaxies are replaced by bulge-dominated disk-like fast-rotator early-type galaxies (ETGs), which follow the same mass-size relation and have the same mass distribution as in the field sample; (2) the slow-rotator ETGs are segregated in mass from the fast rotators, with their size increasing proportionally to their mass. A transition between the two processes appears around the stellar mass M {sub crit} ≈ 2 × 10{sup 11} M {sub ☉}. We interpret this as evidence for bulge growth (outside-in evolution) and bulge-related environmental quenching dominating at low masses, with little influence from merging. In contrast, significant dry mergers (inside-out evolution) and halo-related quenching drives the mass and size growth at the high-mass end. The existence of these two processes naturally explains the diverse size evolution of galaxies of different masses and the separability of mass and environmental quenching.« less

Galaxy clusters in simulations of the local Universe: a matter of constraints

NASA Astrophysics Data System (ADS)

Sorce, Jenny G.; Tempel, Elmo

2018-06-01

To study the full formation and evolution history of galaxy clusters and their population, high-resolution simulations of the latter are flourishing. However, comparing observed clusters to the simulated ones on a one-to-one basis to refine the models and theories down to the details is non-trivial. The large variety of clusters limits the comparisons between observed and numerical clusters. Simulations resembling the local Universe down to the cluster scales permit pushing the limit. Simulated and observed clusters can be matched on a one-to-one basis for direct comparisons provided that clusters are well reproduced besides being in the proper large-scale environment. Comparing random and local Universe-like simulations obtained with differently grouped observational catalogues of peculiar velocities, this paper shows that the grouping scheme used to remove non-linear motions in the catalogues that constrain the simulations affects the quality of the numerical clusters. With a less aggressive grouping scheme - galaxies still falling on to clusters are preserved - combined with a bias minimization scheme, the mass of the dark matter haloes, simulacra for five local clusters - Virgo, Centaurus, Coma, Hydra, and Perseus - is increased by 39 per cent closing the gap with observational mass estimates. Simulacra are found on average in 89 per cent of the simulations, an increase of 5 per cent with respect to the previous grouping scheme. The only exception is Perseus. Since the Perseus-Pisces region is not well covered by the used peculiar velocity catalogue, the latest release lets us foresee a better simulacrum for Perseus in a near future.

Galaxy clusters in the cosmic web

NASA Astrophysics Data System (ADS)

Acebrón, A.; Durret, F.; Martinet, N.; Adami, C.; Guennou, L.

2014-12-01

Simulations of large scale structure formation in the universe predict that matter is essentially distributed along filaments at the intersection of which lie galaxy clusters. We have analysed 9 clusters in the redshift range 0.4

The portrayal of coma in contemporary motion pictures.

PubMed

Wijdicks, Eelco F M; Wijdicks, Coen A

2006-05-09

Coma has been a theme of screenplays in motion pictures, but there is no information about its accuracy. The authors reviewed 30 movies from 1970 to 2004 with actors depicting prolonged coma. Accurate depiction of comatose patients was defined by appearance, the complexity of care, accurate cause of coma and probability of awakening, and appropriate compassionate discussion between the physician and family members. Twenty-two key scenes from 17 movies were rated for accuracy by a panel of neurointensivists and neuroscience nurses and then were shown to 72 nonmedical viewers. Accuracy of the scenes was assessed using a Likert Scale. Coma was most often caused by motor vehicle accidents or violence (63%). The time in a comatose state varied from days to 10 years. Awakening occurred in 18 of 30 motion pictures (60%). Awakening was sudden with cognition intact, even after prolonged time in a coma. Actors personified "Sleeping Beauty" (eyes closed, beautifully groomed). Physicians appeared as caricatures. Only two movies had a reasonable accurate representation (Dream Life of Angels and Reversal of Fortune). The majority of the surveyed viewers identified inaccuracy of representation of coma, awakenings, and conversations on the experience of being in a coma, except in 8 of the 22 scenes (36%). Twenty-eight of the 72 viewers (39%) could potentially allow these scenes to influence decisions in real life. Misrepresentation of coma and awakening was common in motion pictures and impacted on the public perception of coma. Neurologic advice regarding prolonged coma is needed.

These are two images of the inner coma of Comet Hyakutake

NASA Technical Reports Server (NTRS)

2002-01-01

These are two images of the inner coma of Comet Hyakutake made on April 3 and 4, 1996, using the NASA Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2). The first one, shown in red, was taken through a narrow-band red filter that shows only sunlight scattered by dust particles in the inner coma of the comet. The second one, shown in blue was taken with an ultraviolet 'Woods' filter image that shows the distribution of scattered ultraviolet radiation from hydrogen atoms in the inner coma. The coma is the head or dusty-gas atmosphere of a comet. The square field of view is 14,000 km on a side and the sun is toward the upper right corner of the image. Hydrogen atoms represent the most abundant gas in the whole coma of the comet. They are produced when solar ultraviolet light breaks up molecules of water, the major constitutent of the nucleus of the comet. These images were taken as part of an observing program to study water photochemistry in comets. Measurements of hydrogen (H) and hydroxyl (OH) in the coma (or atmosphere) of Comet Hyakutake were also made using the Goddard High Resolution Spectrograph (GHRS) and the Faint Object Spectrograph (FOS). A self-consistent analysis of all the data shows that the water production rate of the comet was between 7 and 8 tons per second on the April 3 and 4. A theoretical model was used in the analysis which accounts for the detailed physics and chemistry of the photochemical destruction of the water, the production of the H and OH, and their expansion in the coma (or atmosphere) of the comet. The model matched the velocity measurements of hydrogen atoms made using the high spectral resolution capabilities of the GHRS instrument. The importance of such a detailed model is that is permits the accurate calculation of the production rate of water from observations of H and OH. The inner yellow region near the center of the red dust image is dominated by the contribution from the dust which shows sunward directed spiral jets toward the upper right, and the thin straight particle trail pointing toward the lower left. The trail was a permanent feature of the comet around the time of its close approach to the earth in late March and early April. Also barely visible just beyond the lower left end of the trail are two of the many condensations which were seen to travel slowly down the tail are are believed to be clumps of material released from the nucleus. The inner white region of the blue image appears to show that the hydrogen atoms like the dust might be preferentially ejected toward the sunward or day side of the nucleus. However, this is not true. The asymmetric ultraviolet radiation pattern is produced by a roughly spherical distribution of hydrogen atoms because they are so efficient at scattering the incoming solar ultraviolet light. The atoms on the sunward side actually shadow the atoms on the tailward or night side of the coma. The same detailed model analysis of the coma which explains the expansion of the hydrogen atoms in the coma also explains the appearance of the image. The team was lead by Michael Combi, The University of Michigan, and included Michael Brown, California Institute of Technology, Paul Feldman, Johns Hopkins University, H. Uwe Keller of the Max Planck Institute, Lindau, Robert Meier of the Naval Research Laboratory, and William Smyth of Atmospheric and Environmental Research, Inc. Credit: M.R. Combi (The University of Michigan)

The Globular Cluster System of the Coma cD Galaxy NGC 4874 from Hubble Space Telescope ACS and WFC3/IR Imaging

NASA Astrophysics Data System (ADS)

Cho, Hyejeon; Blakeslee, John P.; Chies-Santos, Ana L.; Jee, M. James; Jensen, Joseph B.; Peng, Eric W.; Lee, Young-Wook

2016-05-01

We present new Hubble Space Telescope (HST) optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed with the HST Advanced Camera for Surveys in the F475W (g 475) and F814W (I 814) passbands and with the Wide Field Camera 3 IR Channel in F160W (H 160). The GCs in this field exhibit a bimodal optical color distribution with more than half of the GCs falling on the red side at g 475-I 814 > 1. Bimodality is also present, though less conspicuously, in the optical-NIR I 814-H 160 color. Consistent with past work, we find evidence for nonlinearity in the g 475-I 814 versus I 814-H 160 color-color relation. Our results thus underscore the need for understanding the detailed form of the color-metallicity relations in interpreting observational data on GC bimodality. We also find a very strong color-magnitude trend, or “blue tilt,” for the blue component of the optical color distribution of the NGC 4874 GC system. A similarly strong trend is present for the overall mean I 814-H 160 color as a function of magnitude; for M 814 < -10 mag, these trends imply a steep mass-metallicity scaling with Z\\propto {M}{{GC}}1.4+/- 0.4, but the scaling is not a simple power law and becomes much weaker at lower masses. As in other similar systems, the spatial distribution of the blue GCs is more extended than that of the red GCs, partly because of blue GCs associated with surrounding cluster galaxies. In addition, the center of the GC system is displaced by 4 ± 1 kpc toward the southwest from the luminosity center of NGC 4874, in the direction of NGC 4872. Finally, we remark on a dwarf elliptical galaxy with a noticeably asymmetrical GC distribution. Interestingly, this dwarf has a velocity of nearly -3000 km s-1 with respect to NGC 4874; we suggest it is on its first infall into the cluster core and is undergoing stripping of its GC system by the cluster potential. Based on observations with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute (STScI), which is operated by AURA, Inc., under NASA contract NAS 5-26555. These observations are associated with program #11712.

The inter-rater reliability and prognostic value of coma scales in Nepali children with acute encephalitis syndrome.

PubMed

Ray, Stephen; Rayamajhi, Ajit; Bonnett, Laura J; Solomon, Tom; Kneen, Rachel; Griffiths, Michael J

2018-02-01

Background Acute encephalitis syndrome (AES) is a common cause of coma in Nepali children. The Glasgow coma scale (GCS) is used to assess the level of coma in these patients and predict outcome. Alternative coma scales may have better inter-rater reliability and prognostic value in encephalitis in Nepali children, but this has not been studied. The Adelaide coma scale (ACS), Blantyre coma scale (BCS) and the Alert, Verbal, Pain, Unresponsive scale (AVPU) are alternatives to the GCS which can be used. Methods Children aged 1-14 years who presented to Kanti Children's Hospital, Kathmandu with AES between September 2010 and November 2011 were recruited. All four coma scales (GCS, ACS, BCS and AVPU) were applied on admission, 48 h later and on discharge. Inter-rater reliability (unweighted kappa) was measured for each. Correlation and agreement between total coma score and outcome (Liverpool outcome score) was measured by Spearman's rank and Bland-Altman plot. The prognostic value of coma scales alone and in combination with physiological variables was investigated in a subgroup (n = 22). A multivariable logistic regression model was fitted by backward stepwise. Results Fifty children were recruited. Inter-rater reliability using the variables scales was fair to moderate. However, the scales poorly predicted clinical outcome. Combining the scales with physiological parameters such as systolic blood pressure improved outcome prediction. Conclusion This is the first study to compare four coma scales in Nepali children with AES. The scales exhibited fair to moderate inter-rater reliability. However, the study is inadequately powered to answer the question on the relationship between coma scales and outcome. Further larger studies are required.

Kinematic properties and dark matter fraction of Virgo dwarf early-type galaxies

NASA Astrophysics Data System (ADS)

Toloba, E.; Boselli, A.; Peletier, R.; Gorgas, J.

2015-03-01

What happens to dwarf galaxies as they enter the cluster potential well is one of the main unknowns in studies of galaxy evolution. Several evidence suggests that late-type galaxies enter the cluster and are transformed to dwarf early-type galaxies (dEs). We study the Virgo cluster to understand which mechanisms are involved in this transformation. We find that the dEs in the outer parts of Virgo have rotation curves with shapes and amplitudes similar to late-type galaxies of the same luminosity (Fig. 1). These dEs are rotationally supported, have disky isophotes, and younger ages than those dEs in the center of Virgo, which are pressure supported, often have boxy isophotes and are older (Fig. 1). Ram pressure stripping, thus, explains the properties of the dEs located in the outskirts of Virgo. However, the dEs in the central cluster regions, which have lost their angular momentum, must have suffered a more violent transformation. A combination of ram pressure stripping and harassment is not enough to remove the rotation and the spiral/disky structures of these galaxies. We find that on the the Faber-Jackson and the Fundamental Plane relations dEs deviate from the trends of massive elliptical galaxies towards the position of dark matter dominated systems such as the dwarf spheroidal satellites of the Milky Way and M31. Both, rotationally and pressure supported dEs, however, populate the same region in these diagrams. This indicates that dEs have a non-negligible dark matter fraction within their half light radius.

Spatial analysis improves the detection of early corneal nerve fiber loss in patients with recently diagnosed type 2 diabetes

PubMed Central

Winter, Karsten; Strom, Alexander; Zhivov, Andrey; Allgeier, Stephan; Papanas, Nikolaos; Ziegler, Iris; Brüggemann, Jutta; Ringel, Bernd; Peschel, Sabine; Köhler, Bernd; Stachs, Oliver; Guthoff, Rudolf F.; Roden, Michael

2017-01-01

Corneal confocal microscopy (CCM) has revealed reduced corneal nerve fiber (CNF) length and density (CNFL, CNFD) in patients with diabetes, but the spatial pattern of CNF loss has not been studied. We aimed to determine whether spatial analysis of the distribution of corneal nerve branching points (CNBPs) may contribute to improving the detection of early CNF loss. We hypothesized that early CNF decline follows a clustered rather than random distribution pattern of CNBPs. CCM, nerve conduction studies (NCS), and quantitative sensory testing (QST) were performed in a cross-sectional study including 86 patients recently diagnosed with type 2 diabetes and 47 control subjects. In addition to CNFL, CNFD, and branch density (CNBD), CNBPs were analyzed using spatial point pattern analysis (SPPA) including 10 indices and functional statistics. Compared to controls, patients with diabetes showed lower CNBP density and higher nearest neighbor distances, and all SPPA parameters indicated increased clustering of CNBPs (all P<0.05). SPPA parameters were abnormally increased >97.5th percentile of controls in up to 23.5% of patients. When combining an individual SPPA parameter with CNFL, ≥1 of 2 indices were >99th or <1st percentile of controls in 28.6% of patients compared to 2.1% of controls, while for the conventional CNFL/CNFD/CNBD combination the corresponding rates were 16.3% vs 2.1%. SPPA parameters correlated with CNFL and several NCS and QST indices in the controls (all P<0.001), whereas in patients with diabetes these correlations were markedly weaker or lost. In conclusion, SPPA reveals increased clustering of early CNF loss and substantially improves its detection when combined with a conventional CCM measure in patients with recently diagnosed type 2 diabetes. PMID:28296936

On the occurrence of galaxy harassment

NASA Astrophysics Data System (ADS)

Bialas, D.; Lisker, T.; Olczak, C.; Spurzem, R.; Kotulla, R.

2015-04-01

Context. Tidal interactions of galaxies in galaxy clusters have been proposed as one potential explanation of the morphology-density relation at low masses. Earlier studies have shown that galaxy harassment is a suitable mechanism for inducing a morphological transformation from low-mass late-type disk galaxies to the abundant early-type galaxies. Aims: The efficiency of tidal transformation is expected to depend strongly on the orbit of a galaxy within the cluster halo. The orbit determines both the strength of the cluster's global tidal field and the probability of encounters with other cluster members. Here we aim to explore these dependencies. Methods: We use a combination of N-body simulation and Monte-Carlo method to study the efficiency of the transformation of late-type galaxies by tidal interactions on different orbits in a galaxy cluster. Additionally, we investigate the effect of an inclination between the disk of the infalling galaxy and its orbital plane. We compare our results to observational data to assess the possible relevance of such transformations for the existing cluster galaxy population. Results: We find that galaxies that entered a cluster from the outskirts are unlikely to be significantly transformed (stellar mass loss ≤6%). Closer to the cluster centre, tidal interactions are a more efficient mechanism (stellar mass loss up to 50%) for producing harassed galaxies. The inclination of the disk can reduce the mass loss significantly, yet it amplifies the thickening of the galaxy disk. Galaxies with smaller sizes on intermediate orbits are nearly unaffected by tidal interactions. The tidal influence on an infalling galaxy and the likelihood that it leads to galaxy harassment make a very stochastical process that depends on the galaxy's specific history. Conclusions: We conclude that harassment is a suitable mechanism that could explain the transformation of at least a fraction of galaxies inside galaxy clusters. However, the transformation would have to start at an early epoch in protocluster environments and continue until today, in order to result in a complete morphological transformation. Appendices are available in electronic form at http://www.aanda.org

Orbits of Four Very Massive Binaries in the R136 Cluster

NASA Astrophysics Data System (ADS)

Penny, L. R.; Massey, P.; Vukovich, J.

2001-12-01

We present radial velocity and photometry for four early-type, massive double-lined spectroscopic binaries in the R136 cluster. Three of these systems are eclipsing, allowing orbital inclinations to be determined. One of these systems, R136-38 (O3 V + O6 V), has one of the highest masses ever measured, 57 Modot, for the primary. Comparison of our masses with those derived from standard evolutionary tracks shows excellent agreement. We also identify five other light variables in the R136 cluster worthy of follow-up study.

STAR CLUSTERS IN A NUCLEAR STAR FORMING RING: THE DISAPPEARING STRING OF PEARLS

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

Väisänen, Petri; Barway, Sudhanshu; Randriamanakoto, Zara, E-mail: petri@saao.ac.za

2014-12-20

An analysis of the star cluster population in a low-luminosity early-type galaxy, NGC 2328, is presented. The clusters are found in a tight star forming nuclear spiral/ring pattern and we also identify a bar from structural two-dimensional decomposition. These massive clusters are forming very efficiently in the circumnuclear environment and they are young, possibly all less than 30 Myr of age. The clusters indicate an azimuthal age gradient, consistent with a ''pearls-on-a-string'' formation scenario, suggesting bar-driven gas inflow. The cluster mass function has a robust down turn at low masses at all age bins. Assuming clusters are born with a power-lawmore » distribution, this indicates extremely rapid disruption at timescales of just several million years. If found to be typical, it means that clusters born in dense circumnuclear rings do not survive to become old globular clusters in non-interacting systems.« less

EEG and Coma.

PubMed

Ardeshna, Nikesh I

2016-03-01

Coma is defined as a state of extreme unresponsiveness, in which a person exhibits no voluntary movement or behavior even to painful stimuli. The utilization of EEG for patients in coma has increased dramatically over the last few years. In fact, many institutions have set protocols for continuous EEG (cEEG) monitoring for patients in coma due to potential causes such as subarachnoid hemorrhage or cardiac arrest. Consequently, EEG plays an important role in diagnosis, managenent, and in some cases even prognosis of coma patients.

Diversity in the stellar velocity dispersion profiles of a large sample of brightest cluster galaxies z ≤ 0.3

NASA Astrophysics Data System (ADS)

Loubser, S. I.; Hoekstra, H.; Babul, A.; O'Sullivan, E.

2018-06-01

We analyse spatially resolved deep optical spectroscopy of brightestcluster galaxies (BCGs) located in 32 massive clusters with redshifts of 0.05 ≤ z ≤ 0.30 to investigate their velocity dispersion profiles. We compare these measurements to those of other massive early-type galaxies, as well as central group galaxies, where relevant. This unique, large sample extends to the most extreme of massive galaxies, spanning MK between -25.7 and -27.8 mag, and host cluster halo mass M500 up to 1.7 × 1015 M⊙. To compare the kinematic properties between brightest group and cluster members, we analyse similar spatially resolved long-slit spectroscopy for 23 nearby brightest group galaxies (BGGs) from the Complete Local-Volume Groups Sample. We find a surprisingly large variety in velocity dispersion slopes for BCGs, with a significantly larger fraction of positive slopes, unique compared to other (non-central) early-type galaxies as well as the majority of the brightest members of the groups. We find that the velocity dispersion slopes of the BCGs and BGGs correlate with the luminosity of the galaxies, and we quantify this correlation. It is not clear whether the full diversity in velocity dispersion slopes that we see is reproduced in simulations.

M/L, Hα Rotation Curves, and H I Gas Measurements for 329 Nearby Cluster and Field Spirals. III. Evolution in Fundamental Galaxy Parameters

NASA Astrophysics Data System (ADS)

Vogt, Nicole P.; Haynes, Martha P.; Giovanelli, Riccardo; Herter, Terry

2004-06-01

We have conducted a study of optical and H I properties of spiral galaxies (size, luminosity, Hα flux distribution, circular velocity, H I gas mass) to investigate causes (e.g., nature vs. nurture) for variation within the cluster environment. We find H I-deficient cluster galaxies to be offset in fundamental plane space, with disk scale lengths decreased by a factor of 25%. This may be a relic of early galaxy formation, caused by the disk coalescing out of a smaller, denser halo (e.g., higher concentration index) or by truncation of the hot gas envelope due to the enhanced local density of neighbors, although we cannot completely rule out the effect of the gas stripping process. The spatial extent of Hα flux and the B-band radius also decreases, but only in early-type spirals, suggesting that gas removal is less efficient within steeper potential wells (or that stripped late-type spirals are quickly rendered unrecognizable). We find no significant trend in stellar mass-to-light ratios or circular velocities with H I gas content, morphological type, or clustercentric radius, for star-forming spiral galaxies throughout the clusters. These data support the findings of a companion paper that gas stripping promotes a rapid truncation of star formation across the disk and could be interpreted as weak support for dark matter domination over baryons in the inner regions of spiral galaxies.

Subacute sclerosing panencephalitis presenting as schizophrenia with an alpha coma pattern in a child.

PubMed

Kartal, Ayşe; Kurt, Ayşegül Neşe Çitak; Gürkaş, Esra; Aydin, Kurşad; Serdaroğlu, Ayşe

2014-10-01

Subacute sclerosing panencephalitis, a progressive neurodegenerative disorder of the central nervous system, can present atypically with uncharacteristic electroencephalographic (EEG) features at its onset albeit typically with progressive mental deterioration, behavioral changes, and myoclonic jerks. An atypical presentation of subacute sclerosing panencephalitis can lead to a delay in diagnosis, thus hindering early treatment. Herein, we describe a 14-year-old girl who presented with insomnia, amnesia, auditory and visual hallucinations. The patient's electroencephalography on admission showed an alpha coma pattern. In spite of antipsychiatric treatment (olanzapine 20 mg/d) for 3 months, a progressive deterioration in neurologic function was observed. Subacute sclerosing panencephalitis was suspected and diagnosis was confirmed by increased titers of measles antibodies in the cerebrospinal fluid. The attention of pediatricians should be drawn to psychiatric symptoms as possible initial presentations of subacute sclerosing panencephalitis in order to avoid needless diagnostic and treatment procedures. © The Author(s) 2013.

A population of faint low surface brightness galaxies in the Perseus cluster core

NASA Astrophysics Data System (ADS)

Wittmann, Carolin; Lisker, Thorsten; Ambachew Tilahun, Liyualem; Grebel, Eva K.; Conselice, Christopher J.; Penny, Samantha; Janz, Joachim; Gallagher, John S.; Kotulla, Ralf; McCormac, James

2017-09-01

We present the detection of 89 low surface brightness (LSB), and thus low stellar density galaxy candidates in the Perseus cluster core, of the kind named 'ultra-diffuse galaxies', with mean effective V-band surface brightnesses 24.8-27.1 mag arcsec-2, total V-band magnitudes -11.8 to -15.5 mag, and half-light radii 0.7-4.1 kpc. The candidates have been identified in a deep mosaic covering 0.3 deg2, based on wide-field imaging data obtained with the William Herschel Telescope. We find that the LSB galaxy population is depleted in the cluster centre and only very few LSB candidates have half-light radii larger than 3 kpc. This appears consistent with an estimate of their tidal radius, which does not reach beyond the stellar extent even if we assume a high dark matter content (M/L = 100). In fact, three of our candidates seem to be associated with tidal streams, which points to their current disruption. Given that published data on faint LSB candidates in the Coma cluster - with its comparable central density to Perseus - show the same dearth of large objects in the core region, we conclude that these cannot survive the strong tides in the centres of massive clusters.

An exploration of links between early parenting experiences and personality disorder type and disordered personality functioning.

PubMed

Parker, G; Roy, K; Wilhelm, K; Mitchell, P; Austin, M P; Hadzi-Pavlovic, D

1999-01-01

Reports of early parenting were assessed using two measures, the Parental Bonding Index (PBI) and the Measure of Parenting Style (MOPS), in a sample of 265 patients with DSM-defined major depressive disorder. Psychiatrists then rated the extent to which sample members evidenced the personality "styles" underpinning 15 separate personality disorders, returning personality vignette scores. The extent of disordered functioning was also assessed across "parameters" and "domains" by psychiatrists, referrers, and family members, using a range of measures. Those with higher scores on vignettes measuring borderline, anxious, depressive, and self-defeating personality style rated parents as uncaring, overcontrolling, and abusive. When vignettes were consolidated into scores akin to the DSM clusters, the most consistent links between perceived dysfunctional parenting were with the Cluster C (anxious), and Cluster B (dramatic) styles and were nonsignificant for Cluster A (eccentric) style. Meeting criteria for an increasing number of personality disorder clusters was associated with increasing levels of adverse parenting. Multiple regression analyses indicated that disordered functioning (as assessed by the three independent rater groups) was most distinctly associated with paternal indifference and maternal overcontrol.

The dwarf galaxy population of nearby galaxy clusters

NASA Astrophysics Data System (ADS)

Lisker, Thorsten; Wittmann, Carolin; Pak, Mina; Janz, Joachim; Bialas, Daniel; Peletier, Reynier; Grebel, Eva; Falcon Barroso, Jesus; Toloba, Elisa; Smakced Collaboration, Focus Collaboration

2015-01-01

The Fornax, Virgo, Ursa Major and Perseus galaxy clusters all have very different characteristics, in terms of their density, mass, and large-scale environment. We can regard these clusters as laboratories for studying environmental influence on galaxy evolution, using the sensitive low-mass galaxies as probes for external mechanisms. Here we report on recent and ongoing observational studies of the said clusters with imaging and spectroscopy, as well as on the interpretation of present-day cluster galaxy populations with the aid of cosmological simulations.Multicolor imaging data allow us to identify residual star formation in otherwise red early-type dwarf galaxies, which hold clues to the strength of gas stripping processes. Major-axis spectra and 2D kinematical maps provide insight regarding the amount of rotational support and how much dynamical heating a dwarf galaxy may have experienced. To this end, dedicated N-body simulations that follow the evolution of galaxies since early epochs reveal their path through parameter space, and can be compared to observations in order to understand the time-integrated effect of environmental influence.

Myxedema coma leading to respiratory depression in a dog.

PubMed

Atkinson, Kathryn; Aubert, Isabelle

2004-04-01

A 10-year-old, intact male, cocker spaniel was presented with hypothermia, without shivering, and progressive stupor leading to coma. Myxedema coma, potentially precipitated by diuretic therapy, was tentatively diagnosed and treatment initiated, but progressive respiratory depression led to the decision to euthanize. Postmortem findings supported the diagnosis of myxedema coma.

Myxedema coma leading to respiratory depression in a dog

PubMed Central

2004-01-01

Abstract A 10-year-old, intact male, cocker spaniel was presented with hypothermia, without shivering, and progressive stupor leading to coma. Myxedema coma, potentially precipitated by diuretic therapy, was tentatively diagnosed and treatment initiated, but progressive respiratory depression led to the decision to euthanize. Postmortem findings supported the diagnosis of myxedema coma. PMID:15144105

The Environmental Impact of Intra-Cluster Medium on the Interstellar Medium in Early Type Galaxies

NASA Technical Reports Server (NTRS)

Trinchieri, Ginevra

1993-01-01

Draft versions of three articles submitted for publication are presented. The first two articles address high resolution X-ray images of early type galaxies observed with the ROSAT HRI and PSPC. Data for NGC 1553 and NGC 5846 indicate that the emission is highly irregular, with interesting features at different scales. The gas temperatures also vary both with the galactocentric radius and in correspondence to regions of higher emission and denser material. Strikingly similar features are observed in the X-ray and H-alpha morphologies of NGC 1553 and NGC 5846, while smooth, regular isophotes are observed in NGC 4649 at both wavelengths. The third article addresses ROSAT PSPC observations of 5 X-ray bright early type galaxies.

Zeldovich pancakes in observational data are cold

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

Brinckmann, Thejs; Lindholmer, Mikkel; Hansen, Steen

The present day universe consists of galaxies, galaxy clusters, one-dimensional filaments and two-dimensional sheets or pancakes, all of which combine to form the cosmic web. The so called ''Zeldovich pancakes' are very difficult to observe, because their overdensity is only slightly greater than the average density of the universe. Falco et al. [1] presented a method to identify Zeldovich pancakes in observational data, and these were used as a tool for estimating the mass of galaxy clusters. Here we expand and refine that observational detection method. We study two pancakes on scales of 10 Mpc, identified from spectroscopically observed galaxiesmore » near the Coma cluster, and compare with twenty numerical pancakes.We find that the observed structures have velocity dispersions of about 100 km/sec, which is relatively low compared to typical groups and filaments. These velocity dispersions are consistent with those found for the numerical pancakes. We also confirm that the identified structures are in fact two-dimensional structures. Finally, we estimate the stellar to total mass of the observational pancakes to be 2 · 10{sup −4}, within one order of magnitude, which is smaller than that of clusters of galaxies.« less

Severe angioedema in myxedema coma: a difficult airway in a rare endocrine emergency.

PubMed

Lee, Christopher H; Wira, Charles R

2009-10-01

Myxedema coma is the most lethal manifestation of hypothyroidism. It is a true medical emergency and can result in profound hemodynamic instability and airway compromise. Myxedema coma currently remains a diagnostic challenge due to the rarity of cases seen today, and failure to promptly initiate therapy with replacement thyroid hormone can be fatal. As thyroid hormone therapy can take days or weeks to reverse the manifestations of myxedema coma, interim supportive therapy is critical while awaiting clinical improvement. Some patients will require endotracheal intubation in the emergency department (ED), and physicians should be aware that unanticipated posterior pharyngeal edema in myxedema coma could severely complicate airway management. Although mechanical ventilation is a well-described adjunctive therapy for myxedema coma, reports of the potential difficulty in securing a definitive airway in these patients are rare. We describe a case of an unidentified woman who presented to the ED with myxedema coma requiring urgent endotracheal intubation and was found to have extensive posterior pharyngeal angioedema inconsistent with her relatively benign external examination. This case highlights the typical features of myxedema coma and discusses our necessity for a rescue device in definitive endotracheal tube placement. Emergency physicians should anticipate a potentially difficult airway in all myxedema coma patients regardless of the degree of external facial edema present.

Survival rate and expression of Heat-shock protein 70 and Frost genes after temperature stress in Drosophila melanogaster lines that are selected for recovery time from temperature coma.

PubMed

Udaka, Hiroko; Ueda, Chiaki; Goto, Shin G

2010-12-01

In this study, we investigated the physiological mechanisms underlying temperature tolerance using Drosophila melanogaster lines with rapid, intermediate, or slow recovery from heat or chill coma that were established by artificial selection or by free recombination without selection. Specifically, we focused on the relationships among their recovery from heat or chill coma, survival after severe heat or cold, and survival enhanced by rapid cold hardening (RCH) or heat hardening. The recovery time from heat coma was not related to the survival rate after severe heat. The line with rapid recovery from chill coma showed a higher survival rate after severe cold exposure, and therefore the same mechanisms are likely to underlie these phenotypes. The recovery time from chill coma and survival rate after severe cold were unrelated to RCH-enhanced survival. We also examined the expression of two genes, Heat-shock protein 70 (Hsp70) and Frost, in these lines to understand the contribution of these stress-inducible genes to intraspecific variation in recovery from temperature coma. The line showing rapid recovery from heat coma did not exhibit higher expression of Hsp70 and Frost. In addition, Hsp70 and Frost transcription levels were not correlated with the recovery time from chill coma. Thus, Hsp70 and Frost transcriptional regulation was not involved in the intraspecific variation in recovery from temperature coma. Copyright © 2010 Elsevier Ltd. All rights reserved.

Childhood acute non-traumatic coma: aetiology and challenges in management in resource-poor countries of Africa and Asia.

PubMed

Gwer, Samson; Chacha, Clifford; Newton, Charles R; Idro, Richard

2013-08-01

This review examines the best available evidence on the aetiology of childhood acute non-traumatic coma in resource-poor countries (RPCs), discusses the challenges associated with management, and explores strategies to address them. Publications in English and French which reported on studies on the aetiology of childhood non-traumatic coma in RPCs are reviewed. Primarily, the MEDLINE database was searched using the keywords coma, unconsciousness, causality, aetiology, child, malaria cerebral, meningitis, encephalitis, Africa, Asia, and developing countries. 14 records were identified for inclusion in the review. Cerebral malaria (CM) was the commonest cause of childhood coma in most of the studies conducted in Africa. Acute bacterial meningitis (ABM) was the second most common known cause of coma in seven of the African studies. Of the studies in Asia, encephalitides were the commonest cause of coma in two studies in India, and ABM was the commonest cause of coma in Pakistan. Streptococcus pneumoniae was the most commonly isolated organism in ABM. Japanese encephalitis, dengue fever and enteroviruses were the viral agents most commonly isolated. Accurate diagnosis of the aetiology of childhood coma in RPCs is complicated by overlap in clinical presentation, limited diagnostic resources, disease endemicity and co-morbidity. For improved outcomes, studies are needed to further elucidate the aetiology of childhood coma in RPCs, explore simple and practical diagnostic tools, and investigate the most appropriate specific and supportive interventions to manage and prevent infectious encephalopathies.

'Is she alive? Is she dead?' Representations of chronic disorders of consciousness in Douglas Coupland's Girlfriend in a Coma.

PubMed

Colbeck, Matthew

2016-09-01

Depictions of coma have come to dominate literary and filmic texts over the last half century, a phenomenon coinciding with advancements in medical technology that have led to remarkable increases in the survival rates of patients with chronic disorders of consciousness. Authors of coma fiction are preoccupied with the imagined subjective experience of coma, often creating complex, dream-like worlds from which the protagonist must escape if survival is to be achieved. However, such representations appear to conflict with medical case studies and patient narratives that reveal that most often survivors of coma have no recollection of the coma itself. Providing a close reading of Douglas Coupland's Girlfriend in a Coma (1998) against the context of medical literature and diagnoses, this article examines how the coma patient is represented, often depicting the realities of a prolonged vegetative state, in contrast with other popular representations of coma. It explores how the author develops a work of 'fantastic' fiction (a genre defined by the structuralist critic Tzvetan Todorov), using the condition of coma as a metaphor for a postmodern existential crisis, while simultaneously employing mimetic techniques that raise important medical, ethical and philosophical questions surrounding the ontological status of the comatose patient. It is argued that coma fiction, even in its misrepresentation of the condition, can help us to engage with and interrogate how we think about chronic disorders of consciousness, thereby providing a valuable insight into our attitudes towards illness and mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

ERRATUM: 'MAPPING THE GAS TURBULENCE IN THE COMA CLUSTER: PREDICTIONS FOR ASTRO-H'

NASA Technical Reports Server (NTRS)

Zuhone, J. A.; Markevitch, M.; Zhuravleva, I.

2016-01-01

The published version of this paper contained an error in Figure 5. This figure is intended to show the effect on the structure function of subtracting the bias induced by the statistical and systematic errors on the line shift. The filled circles show the bias-subtracted structure function. The positions of these points in the left panel of the original figure were calculated incorrectly. The figure is reproduced below (with the original caption) with the correct values for the bias-subtracted structure function. No other computations or figures in the original manuscript are affected.

The Size Distribution Of Cluster Galaxies

NASA Astrophysics Data System (ADS)

Kuchner, U.; Ziegler, B.; Bamford, S.; Verdugo, M.; Haeussler, B.

2017-06-01

We establish a sample of 560 spectroscopically confirmed cluster members of MACS J1206.2- 0847 at z = 0.45 and utilize multi-wavelength and multi-component Sersic profile fitting to provide luminosities and sizes for the key structural components bulge and disk. While the difference between field and cluster galaxy properties are mostly due to a preference for cluster members to be early-type (quiescent, bulge-dominated), we see evidence for an outer disk fading and a sharp rise in the number of red disks with smaller effective radii at the tidally active cluster region around R200. Even though red disks are already virialized according to their velocity distribution, they are clearly not part of the old population found in the innermost region; they represent an important population of transitional objects in clusters.

Early-type galaxies: mass-size relation at z ˜ 1.3 for different environments

NASA Astrophysics Data System (ADS)

Raichoor, A.; Mei, S.; Stanford, S. A.; Holden, B. P.; Nakata, F.; Rosati, P.; Shankar, F.; Tanaka, M.; Ford, H.; Huertas-Company, M.; Illingworth, G.; Kodama, T.; Postman, M.; Rettura, A.; Blakeslee, J. P.; Demarco, R.; Jee, M. J.; White, R. L.

2011-12-01

We combine multi-wavelength data of the Lynx superstructure and GOODS/CDF-S to build a sample of 75 visually selected early-type galaxies (ETGs), spanning different environments (cluster/group/field) at z ˜ 1.3. By estimating their mass, age (SED fitting, with a careful attention to the stellar population model used) and size, we are able to probe the dependence on the environment of the mass-size relation. We find that, for ETGs with 10^{10} < M / M_⊙ < 10^{11.5}, (1) the mass-size relation in the field did not evolve overall from z ˜ 1.3 to present; (2) the mass-size relation in cluster/group environments at z ˜ 1.3 lies at smaller sizes than the local mass-size relation (R_{e,z ˜ 1.3}/R_{e,z = 0} ˜ 0.6-0.8).

LUMINOSITY FUNCTIONS OF LMXBs IN CENTAURUS A: GLOBULAR CLUSTERS VERSUS THE FIELD

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

Voss, Rasmus; Gilfanov, Marat; Sivakoff, Gregory R.

2009-08-10

We study the X-ray luminosity function (XLF) of low-mass X-ray binaries (LMXB) in the nearby early-type galaxy Centaurus A, concentrating primarily on two aspects of binary populations: the XLF behavior at the low-luminosity limit and the comparison between globular cluster and field sources. The 800 ksec exposure of the deep Chandra VLP program allows us to reach a limiting luminosity of {approx}8 x 10{sup 35} erg s{sup -1}, about {approx}2-3 times deeper than previous investigations. We confirm the presence of the low-luminosity break of the overall LMXB XLF at log(L{sub X} ) {approx} 37.2-37.6, below which the luminosity distribution followsmore » a dN/d(ln L) {approx} const law. Separating globular cluster and field sources, we find a statistically significant difference between the two luminosity distributions with a relative underabundance of faint sources in the globular cluster population. This demonstrates that the samples are drawn from distinct parent populations and may disprove the hypothesis that the entire LMXB population in early-type galaxies is created dynamically in globular clusters. As a plausible explanation for this difference in the XLFs, we suggest an enhanced fraction of helium-accreting systems in globular clusters, which are created in collisions between red giants and neutron stars. Due to the four times higher ionization temperature of He, such systems are subject to accretion disk instabilities at {approx}20 times higher mass accretion rate and, therefore, are not observed as persistent sources at low luminosities.« less

Glasgow Coma Scale Scores, Early Opioids, and 4-year Psychological Outcomes among Combat Amputees

DTIC Science & Technology

2014-01-01

psychological outcomes, loss of consciousness, military and VA health data, morphine , posttraumatic stress disorder, traumatic brain injury. INTRODUCTION...appropriate for postinjury analgesia [15–17]. Unfortu- nately, little research has compared the psychological benefits of morphine or fentanyl...that morphine reduced PTSD compared with fentanyl because mor- phine produced more long-lasting pain relief and/or was more effective at blocking

[Brain function recovery after prolonged posttraumatic coma].

PubMed

Klimash, A V; Zhanaidarov, Z S

2016-01-01

To explore the characteristics of brain function recovery in patients after prolonged posttraumatic coma and with long-unconscious states. Eighty-seven patients after prolonged posttraumatic coma were followed-up for two years. An analysis of a clinical/neurological picture after a prolonged episode of coma was based on the dynamics of vital functions, neurological status and patient's reactions to external stimuli. Based on the dynamics of the clinical/neurological picture that shows the recovery of functions of the certain brain areas, three stages of brain function recovery after a prolonged episode of coma were singled out: brain stem areas, diencephalic areas and telencephalic areas. These functional/anatomic areas of brain function recovery after prolonged coma were compared to the present classifications.

Millimeter and Submillimeter Observations of comet 67P/C-G with the MIRO Instrument

NASA Astrophysics Data System (ADS)

Hofstadter, Mark D.; Allen, Mark; von Allmen, Paul; Beaudin, Gerard; Biver, Nicolas; Bockelee-Morvan, Dominique; Choukroun, Mathieu; Crovisier, Jacques; Encrenaz, Pierre; Encrenaz, Therese; Frerking, Margaret; Gulkis, Samuel; Hartogh, Paul; Ip, Wing; Janssen, Michael; Jarchow, Christopher; Kamp, Lucas; Keihm, Stephen; Lee, Seungwon; Lellouch, Emmanuel; Leyrat, Cedric; Rezac, Ladislav; Schloerb, Frederick P.; Spilker, Thomas

2014-11-01

The Microwave Instrument for the Rosetta Orbiter (MIRO) makes millimeter and submillimeter observations of the nucleus and coma of Rosetta's target comet. This presentation summarizes the instrument and its observations, with details presented in later talks. MIRO makes continuum measurements at 190 and 563 GHz (1.6 and 0.5 mm) to study the thermal and electrical properties of the nucleus near-surface (depths from ~1 millimeter to 10 centimeters). MIRO also makes spectroscopic measurements of 8 lines near 560 GHz (H2O, H217O, H218O, CO, NH3, and three CH3OH transitions). The abundance, gas velocity, and temperature of those species are measured as functions of time and location. To interpret its data, the MIRO team has developed sophisticated nucleus and coma models. Our goal is to understand the dominant physical processes that create the coupled nucleus-coma system. MIRO has clearly detected water in the coma since 6 June 2014 (heliocentric distance 3.9 AU). Water production varies both with location on the nucleus and time-of-day. We also see an overall increase in production as the comet approaches the Sun. At the time of this writing, only H2O and H218O have been detected by MIRO. Our analysis of spectral data uses a non-LTE coma model, accounting for the boundary layer at the nucleus, regions dominated by gas collisions, electron collisions, and radiative processes. MIRO's continuum channels have detected the nucleus since 19 July 2014, and it has been spatially resolved since early August. Initial results are consistent with a very low thermal inertia surface, as expected for a porous, dusty layer. We expect to provide information on spatial variability of nucleus properties at the meeting. MIRO has developed a 3-D nucleus thermal/radiative model to assist in observation planning and interpretation. In addition to its science objectives, MIRO provides information in support of spacecraft operations. Measurements help predict the gas drag on the spacecraft, and were used in determining the shape of un-illuminated regions of the nucleus and in selecting possible landing sites.

Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 cm width

NASA Technical Reports Server (NTRS)

Bernstein, Gary M.; Guhathakurta, Puragra; Raychaudhury, Somak; Giovanelli, Riccardo; Haynes, Martha P.; Herter, Terry; Vogt, Nicole P.

1994-01-01

We examine the precision of the Tully-Fisher relation (TFR) using a sample of galaxies in the Coma region of the sky, and find that it is good to 5% or better in measuring relative distances. Total magnitudes and disk axis ratios are derived from H and I band surface photometry, and Arecibo 21 cm profiles define the rotation speeds of the galaxies. Using 25 galaxies for which the disk inclination and 21 cm width are well defined, we find an rms deviation of 0.10 mag from a linear TFR with dI/d(log W(sub c)) = -5.6. Each galaxy is assumed to be at a distance proportional to its redshift, and an extinction correction of 1.4(1-b/a) mag is applied to the total I magnitude. The measured scatter is less than 0.15 mag using milder extinction laws from the literature. The I band TFR scatter is consistent with measurement error, and the 95% CL limits on the intrinsic scatter are 0-0.10 mag. The rms scatter using H band magnitudes is 0.20 mag (N = 17). The low width galaxies have scatter in H significantly in excess of known measurement error, but the higher width half of the galaxies have scatter consistent with measurement error. The H band TFR slope may be as steep as the I band slope. As the first applications of this tight correlation, we note the following: (1) the data for the particular spirals commonly used to define the TFR distance to the Coma cluster are inconsistent with being at a common distance and are in fact in free Hubble expansion, with an upper limit of 300 km/s on the rms peculiar line-of-sight velocity of these gas-rich spirals; and (2) the gravitational potential in the disks of these galaxies has typical ellipticity less than 5%. The published data for three nearby spiral galaxies with Cepheid distance determinations are inconsistent with our Coma TFR, suggesting that these local calibrators are either ill-measured or peculiar relative to the Coma Supercluster spirals, or that the TFR has a varying form in different locales.

Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 CM width

NASA Astrophysics Data System (ADS)

Bernstein, Gary M.; Guhathakurta, Puragra; Raychaudhury, Somak; Giovanelli, Riccardo; Haynes, Martha P.; Herter, Terry; Vogt, Nicole P.

1994-06-01

We examine the precision of the Tully-Fisher relation (TFR) using a sample of galaxies in the Coma region of the sky, and find that it is good to 5% or better in measuring relative distances. Total magnitudes and disk axis ratios are derived from H and I band surface photometry, and Arecibo 21 cm profiles define the rotation speeds of the galaxies. Using 25 galaxies for which the disk inclination and 21 cm width are well defined, we find an rms deviation of 0.10 mag from a linear TFR with dI/d(log Wc) = -5.6. Each galaxy is assumed to be at a distance proportional to its redshift, and an extinction correction of 1.4(1-b/a) mag is applied to the total I magnitude. The measured scatter is less than 0.15 mag using milder extinction laws from the literature. The I band TFR scatter is consistent with measurement error, and the 95% CL limits on the intrinsic scatter are 0-0.10 mag. The rms scatter using H band magnitudes is 0.20 mag (N = 17). The low width galaxies have scatter in H significantly in excess of known measurement error, but the higher width half of the galaxies have scatter consistent with measurement error. The H band TFR slope may be as steep as the I band slope. As the first applications of this tight correlation, we note the following: (1) the data for the particular spirals commonly used to define the TFR distance to the Coma cluster are inconsistent with being at a common distance and are in fact in free Hubble expansion, with an upper limit of 300 km/s on the rms peculiar line-of-sight velocity of these gas-rich spirals; and (2) the gravitational potential in the disks of these galaxies has typical ellipticity less than 5%. The published data for three nearby spiral galaxies with Cepheid distance determinations are inconsistent with our Coma TFR, suggesting that these local calibrators are either ill-measured or peculiar relative to the Coma Supercluster spirals, or that the TFR has a varying form in different locales.

Gravitational anti-screening as an alternative to dark matter

NASA Astrophysics Data System (ADS)

Penner, A. Raymond

2016-04-01

A semiclassical model of the screening of electric charge by virtual electric dipoles, as found in electrodynamic theory, will be presented. This model is then applied to the hypothetical case of an electric force where like charges attract. The resulting anti-screening of the electric charge is found to have the same functional dependence on the field source and observation distance that is found with the Baryonic Tully-Fisher Relationship. This leads to an anti-screening model for the gravitational force which is then used to determine the theoretical rotational curve of the Galaxy and the theoretical velocity dispersions and shear values for the Coma cluster. These theoretical results are found to be in good agreement with the corresponding astronomical observations. The screening of electric charge as found in QED and the larger apparent masses of galaxies and galactic clusters therefore appears to be two sides of the same coin.

Are the virial masses of clusters smaller than we think?

NASA Technical Reports Server (NTRS)

Cowie, L. L.; Henriksen, M.; Mushotzky, R.

1987-01-01

The constraints that the available X-ray spectral and imaging data place on the mass distribution and mass to light ratio of rich clusters are considered. It was found for the best determined cases that the mass to light ratio is less than 125 h sub 50 at radii exceeding 1 h sub 50 Mpc. The mass to light ratio is approximately constant at radii exceeding 1 h sub 50 Mpc but may rise to values of roughly 200 h sub 50 in the central regions. The fraction of the total mass that is in baryons, primarily the hot X-ray emitting gas, is roughly 30 percent thus setting the mass to light ratio of the dark material to roughly 70. The model that fits the X-ray data for Coma is in good agreement with the observed optical velocity dispersion vs. radius data.

Are the virial masses of clusters smaller than we think?

NASA Technical Reports Server (NTRS)

Cowie, L. L.; Henriksen, M.; Mushotzky, R.

1986-01-01

The constraints that the available X-ray spectral and imaging data place on the mass distribution and mass to light ratio of rich clusters are considered. It was found for the best determined cases that the mass to light ratio is less than 125 h sub 50 at radii exceeding 1 h sub 50 Mpc. The mass to light ratio is approximately constant at radii exceeding 1 h sub 50 Mpc but may rise to values of roughly 200 h sub 50 in the central regions. The fraction of the total mass that is in baryons, primarily the hot X-ray emitting gas, is roughly 30% thus setting the mass to light ratio of the dark material to roughly 70. The model that fits the X-ray data for Coma is in good agreement with the observed optical velocity dispersion vs. radius data.

Evidence for biasing in the CfA survey

NASA Technical Reports Server (NTRS)

Hamilton, A. J. S.

1988-01-01

Intrinsically bright galaxies appear systematically more correlated than faint galaxies in the Center for Astrophysics redshift survey. The amplification of the two-point correlation function behaves exponentially with luminosity, being essentially flat up to the knee of the luminosity function, then increasing markedly. The amplification reaches a factor of 3.5e + or - 0.4 in the very brightest galaxies. The effect is dominated by spirals rather than ellipticals, so that the correlation function of bright spirals becomes comparable to that of normal ellipticals. Similar results are obtained whether the correlation function is measured in two or three dimensions. The effect persists to separations of a correlation length or more, and is not confined to the cores of the Virgo, Coma, and Abell 1367 clusters, suggesting that the effect is caused by biasing, that is, galaxies kindle preferentially in more clustered regions, rather than by gravitational relaxation.

Dynamical Effects of the Scale Invariance of the Empty Space: The Fall of Dark Matter?

NASA Astrophysics Data System (ADS)

Maeder, Andre

2017-11-01

The hypothesis of the scale invariance of the macroscopic empty space, which intervenes through the cosmological constant, has led to new cosmological models. They show an accelerated cosmic expansion after the initial stages and satisfy several major cosmological tests. No unknown particles are needed. Developing the weak-field approximation, we find that the here-derived equation of motion corresponding to Newton’s equation also contains a small outward acceleration term. Its order of magnitude is about \\sqrt{{\\varrho }{{c}}/\\varrho } × Newton’s gravity (ϱ being the mean density of the system and {\\varrho }{{c}} the usual critical density). The new term is thus particularly significant for very low density systems. A modified virial theorem is derived and applied to clusters of galaxies. For the Coma Cluster and Abell 2029, the dynamical masses are about a factor of 5-10 smaller than in the standard case. This tends to leave no room for dark matter in these clusters. Then, the two-body problem is studied and an equation corresponding to the Binet equation is obtained. It implies some secular variations of the orbital parameters. The results are applied to the rotation curve of the outer layers of the Milky Way. Starting backward from the present rotation curve, we calculate the past evolution of the Galactic rotation and find that, in the early stages, it was steep and Keplerian. Thus, the flat rotation curves of galaxies appear as an age effect, a result consistent with recent observations of distant galaxies by Genzel et al. and Lang et al. Finally, in an appendix we also study the long-standing problem of the increase with age of the vertical velocity dispersion in the Galaxy. The observed increase appears to result from the new small acceleration term in the equation of the harmonic oscillator describing stellar motions around the Galactic plane. Thus, we tend to conclude that neither dark energy nor dark matter seems to be needed in the proposed theoretical context.

Accuracy of self-reported length of coma and posttraumatic amnesia in persons with medically verified traumatic brain injury.

PubMed

Sherer, Mark; Sander, Angelle M; Maestas, Kacey Little; Pastorek, Nicholas J; Nick, Todd G; Li, Jingyun

2015-04-01

To determine the accuracy of self-reported length of coma and posttraumatic amnesia (PTA) in persons with medically verified traumatic brain injury (TBI) and to investigate factors that affect self-report of length of coma and PTA duration. Prospective cohort study. Specialized rehabilitation center with inpatient and outpatient programs. Persons (N=242) with medically verified TBI who were identified from a registry of persons who had previously participated in TBI-related research. Not applicable. Self-reported length of coma and self-reported PTA duration. Review of medical records revealed that the mean medically documented length of coma and PTA duration was 6.9±12 and 19.2±22 days, respectively, and the mean self-reported length of coma and PTA duration was 16.7±22 and 106±194 days, respectively. The average discrepancy between self-report and medical record for length of coma and PTA duration was 8.2±21 and 64±176 days, respectively. Multivariable regression models revealed that time since injury, performance on cognitive tests, and medical record values were associated with self-reported values for both length of coma and PTA duration. In this investigation, persons with medically verified TBI showed poor accuracy in their self-report of length of coma and PTA duration. Discrepancies were large enough to affect injury severity classification. Caution should be exercised when considering self-report of length of coma and PTA duration. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Comet Hyakutake C/1996 B2

NASA Technical Reports Server (NTRS)

1998-01-01

These are two images of the inner coma of Comet Hyakutake made on April 3 and 4, 1996, using the NASA Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2). The first one, shown in red, was taken through a narrow-band red filter that shows only sunlight scattered by dust particles in the inner coma of the comet. The second one, shown in blue was taken with an ultraviolet 'Woods' filter image that shows the distribution of scattered ultraviolet radiation from hydrogen atoms in the inner coma. The coma is the head or dusty-gas atmosphere of a comet. The square field of view is 14,000 km on a side and the sun is toward the upper right corner of the image. Hydrogen atoms represent the most abundant gas in the whole coma of the comet. They are produced when solar ultraviolet light breaks up molecules of water, the major constituent of the nucleus of the comet. These images were taken as part of an observing program to study water photochemistry in comets. Measurements of hydrogen (H) and hydroxyl (OH) in the coma (or atmosphere) of Comet Hyakutake were also made using the Goddard High Resolution Spectrograph (GHRS) and the Faint Object Spectrograph (FOS). A self-consistent analysis of all the data shows that the water production rate of the comet was between 7 and 8 tons per second on the April 3 and 4. A theoretical model was used in the analysis which accounts for the detailed physics and chemistry of the photochemical destruction of the water, the production of the H and OH, and their expansion in the coma (or atmosphere) of the comet. The model matched the velocity measurements of hydrogen atoms made using the high spectral resolution capabilities of the GHRS instrument. The importance of such a detailed model is that is permits the accurate calculation of the production rate of water from observations of H and OH.

The inner yellow region near the center of the red dust image is dominated by the contribution from the dust which shows sunward directed spiral jets toward the upper right, and the thin straight particle trail pointing toward the lower left. The trail was a permanent feature of the comet around the time of its close approach to the Earth in late March and early April. Also barely visible just beyond the lower left end of the trail are two of the many condensations which were seen to travel slowly down the tail are believed to be clumps of material released from the nucleus.

The inner white region of the blue image appears to show that the hydrogen atoms like the dust might be preferentially ejected toward the sunward or day side of the nucleus. However, this is not true. The asymmetric ultraviolet radiation pattern is produced by a roughly spherical distribution of hydrogen atoms because they are so efficient at scattering the incoming solar ultraviolet light. The atoms on the sunward side actually shadow the atoms on the tailward or night side of the coma. The same detailed model analysis of the coma which explains the expansion of the hydrogen atoms in the coma also explains the appearance of the image.

The team was lead by Michael Combi, The University of Michigan, and included Michael Brown, California Institute of Technology, Paul Feldman, Johns Hopkins University, H. Uwe Keller of the Max Planck Institute, Lindau, Robert Meier of the Naval Research Laboratory, and William Smyth of Atmospheric and Environmental Research, Inc.

The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS).

PubMed

Dixit, Siddharth; Dutta, Manoj Kumar; Namdeo, Mayank

2015-05-01

Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity of classical NMS contributing to diagnostic problem and treatment delay. Scientific literature on coexistance of myxedema coma and NMS is sparse. We hereby report first case with coexisting myxedema coma and NMS in a patient of schizophrenia treated with antipsychotic, where classical symptoms of NMS were masked by myxedema coma. Prompt diagnosis and effective management by a team resulted in favourable outcome in our patient. This case is reported to alert intensive care physicians to atypical manifestations of NMS in presence of hypothyroidism.

A Rare Case of Myxedema Coma with Neuroleptic Malignant Syndrome (NMS)

PubMed Central

Dutta, Manoj Kumar; Namdeo, Mayank

2015-01-01

Myxedema coma or hypothyroid crisis is an endocrine emergency and needs ICU management. Neuroleptic malignant syndrome (NMS) is another medical emergency which needs high degree of clinical suspicion else mortality can be high. There is a paradox in co existence of myxedema coma and NMS. While one is hypometabolic state another is hypermetabolic state and both can be precipitated by antipsychotics use. Hypothermia and flaccidity commonly expected in myxedema coma may mask fever and rigidity of classical NMS contributing to diagnostic problem and treatment delay. Scientific literature on coexistance of myxedema coma and NMS is sparse. We hereby report first case with coexisting myxedema coma and NMS in a patient of schizophrenia treated with antipsychotic, where classical symptoms of NMS were masked by myxedema coma. Prompt diagnosis and effective management by a team resulted in favourable outcome in our patient. This case is reported to alert intensive care physicians to atypical manifestations of NMS in presence of hypothyroidism. PMID:26155541

Comet coma sample return instrument

NASA Technical Reports Server (NTRS)

Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

1994-01-01

The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

The complete Einstein Observatory X-ray survey of the Orion Nebula region.

NASA Technical Reports Server (NTRS)

Gagne, Marc; Caillault, Jean-Pierre

1994-01-01

We have analyzed archival Einstein Observatory images of a roughly 4.5 square degree region centered on the Orion Nebula. In all, 245 distinct X-ray sources have been detected in six High Resolution Imager (HRI) and 17 Imaging Proportional Counter (IPC) observations. An optical database of over 2700 stars has been assembled to search for candidate counterparts to the X-ray sources. Roughly half the X-ray sources are identified with a single Orion Nebula cluster member. The 10 main-sequence O6-B5 cluster stars detected in Orion have X-ray activity levels comparable to field O and B stars. X-ray emission has also been detected in the direction of four main-sequence late-B and early-A type stars. Since the mechanisms producing X-rays in late-type coronae and early-type winds cannot operate in the late-B and early-A type atmospheres, we argue that the observed X-rays, with L(sub X) approximately = 3 x 10(exp 30) ergs/s, are probably produced in the coronae of unseen late-type binary companions. Over 100 X-ray sources have been associated with late-type pre-main sequence stars. The upper envelope of X-ray activity rises sharply from mid-F to late-G, with L(sub x)/L(sub bol) in the range 10(exp -4) to 2 x 10(exp -3) for stars later than approximately G7. We have looked for variability of the late-type cluster members on timescales of a day to a year and find that 1/4 of the stars show significantly variable X-ray emission. A handful of the late-type stars have published rotational periods and spectroscopic rotational velocities; however, we see no correlation between X-ray activity and rotation. Thus, for this sample of pre-main-sequence stars, the large dispersion in X-ray activity does not appear to be caused by the dispersion in rotation, in contrast with results obtained for low-mass main-sequence stars in the Pleiades and pre-main-sequence stars in Taurus-Auriga.

Theory of mind predicts severity level in autism.

PubMed

Hoogenhout, Michelle; Malcolm-Smith, Susan

2017-02-01

We investigated whether theory of mind skills can indicate autism spectrum disorder severity. In all, 62 children with autism spectrum disorder completed a developmentally sensitive theory of mind battery. We used intelligence quotient, Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnosis and level of support needed as indicators of severity level. Using hierarchical cluster analysis, we found three distinct clusters of theory of mind ability: early-developing theory of mind (Cluster 1), false-belief reasoning (Cluster 2) and sophisticated theory of mind understanding (Cluster 3). The clusters corresponded to severe, moderate and mild autism spectrum disorder. As an indicator of level of support needed, cluster grouping predicted the type of school children attended. All Cluster 1 children attended autism-specific schools; Cluster 2 was divided between autism-specific and special needs schools and nearly all Cluster 3 children attended general special needs and mainstream schools. Assessing theory of mind skills can reliably discriminate severity levels within autism spectrum disorder.

The ATLAS3D project - X. On the origin of the molecular and ionized gas in early-type galaxies

NASA Astrophysics Data System (ADS)

Davis, Timothy A.; Alatalo, Katherine; Sarzi, Marc; Bureau, Martin; Young, Lisa M.; Blitz, Leo; Serra, Paolo; Crocker, Alison F.; Krajnović, Davor; McDermid, Richard M.; Bois, Maxime; Bournaud, Frédéric; Cappellari, Michele; Davies, Roger L.; Duc, Pierre-Alain; de Zeeuw, P. Tim; Emsellem, Eric; Khochfar, Sadegh; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Scott, Nicholas; Weijmans, Anne-Marie

2011-10-01

We make use of interferometric CO and H I observations, and optical integral-field spectroscopy from the ATLAS3D survey, to probe the origin of the molecular and ionized interstellar medium (ISM) in local early-type galaxies. We find that 36 ± 5 per cent of our sample of fast-rotating early-type galaxies have their ionized gas kinematically misaligned with respect to the stars, setting a strong lower limit on the importance of externally acquired gas (e.g. from mergers and cold accretion). Slow rotators have a flat distribution of misalignments, indicating that the dominant source of gas is external. The molecular, ionized and atomic gas in all the detected galaxies are always kinematically aligned, even when they are misaligned from the stars, suggesting that all these three phases of the ISM share a common origin. In addition, we find that the origin of the cold and warm gas in fast-rotating early-type galaxies is strongly affected by environment, despite the molecular gas detection rate and mass fractions being fairly independent of group/cluster membership. Galaxies in dense groups and the Virgo cluster nearly always have their molecular gas kinematically aligned with the stellar kinematics, consistent with a purely internal origin (presumably stellar mass loss). In the field, however, kinematic misalignments between the stellar and gaseous components indicate that at least 42 ± 5 per cent of local fast-rotating early-type galaxies have their gas supplied from external sources. When one also considers evidence of accretion present in the galaxies' atomic gas distributions, ≳46 per cent of fast-rotating field ETGs are likely to have acquired a detectable amount of ISM from accretion and mergers. We discuss several scenarios which could explain the environmental dichotomy, including preprocessing in galaxy groups/cluster outskirts and the morphological transformation of spiral galaxies, but we find it difficult to simultaneously explain the kinematic misalignment difference and the constant detection rate. Furthermore, our results suggest that galaxy mass may be an important independent factor associated with the origin of the gas, with the most massive fast-rotating galaxies in our sample (MK≲-24 mag; stellar mass of ≈8 × 1010 M⊙) always having kinematically aligned gas. This mass dependence appears to be independent of environment, suggesting it is caused by a separate physical mechanism.

MID-INFRARED EVIDENCE FOR ACCELERATED EVOLUTION IN COMPACT GROUP GALAXIES

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

Walker, Lisa May; Johnson, Kelsey E.; Gallagher, Sarah C.

2010-11-15

Compact galaxy groups are at the extremes of the group environment, with high number densities and low velocity dispersions that likely affect member galaxy evolution. To explore the impact of this environment in detail, we examine the distribution in the mid-infrared (MIR) 3.6-8.0 {mu}m color space of 42 galaxies from 12 Hickson compact groups (HCGs) in comparison with several control samples, including the LVL+SINGS galaxies, interacting galaxies, and galaxies from the Coma Cluster. We find that the HCG galaxies are strongly bimodal, with statistically significant evidence for a gap in their distribution. In contrast, none of the other samples showmore » such a marked gap, and only galaxies in the Coma infall region have a distribution that is statistically consistent with the HCGs in this parameter space. To further investigate the cause of the HCG gap, we compare the galaxy morphologies of the HCG and LVL+SINGS galaxies, and also probe the specific star formation rate (SSFR) of the HCG galaxies. While galaxy morphology in HCG galaxies is strongly linked to position with MIR color space, the more fundamental property appears to be the SSFR, or star formation rate normalized by stellar mass. We conclude that the unusual MIR color distribution of HCG galaxies is a direct product of their environment, which is most similar to that of the Coma infall region. In both cases, galaxy densities are high, but gas has not been fully processed or stripped. We speculate that the compact group environment fosters accelerated evolution of galaxies from star-forming and neutral gas-rich to quiescent and neutral gas-poor, leaving few members in the MIR gap at any time.« less

Monte Carlo Particle Trajectory Models for Neutral Cometary Gases. II. The Spatial Morphology of the Lyman-Alpha Coma

NASA Astrophysics Data System (ADS)

Combi, Michael R.; Smyth, William H.

1988-04-01

The Monte Carlo particle-trajectory model (MCPTM) developed in Paper 1 is applied to explain the observed morphology of the spatially extended Lyα comae of comets. The physical processes and assumptions used in the model as they relate to the photodissociation of H2O and OH and the solar radiation pressure acceleration are presented herein. For this first application, the rocket and Skylab images of the Lyα coma of comet Kohoutek were chosen for study. The self-consistent modeling analysis of these data consisted of two parts. The first part entailed using a steady state spherically symmetric inner coma MCPTM coupled with a simple gas-dynamic model to calculate the physical development of the coma, i.e., the dependence of coma temperature and outflow speed on radial distance to the center of the nucleus, as a function of the (time) heliocentric distance of the comet. The inner coma MCPTM was used to calculate correctly the photo-chemical heating of the coma due to the partial collisional thermalization of the hot hydrogen atoms produced in the photodissociation of water molecules. In the second part of the analysis the results from the first part were used in a fully time-dependent and three-dimensional extended coma MCPTM which includes the explicit calculation of partial thermalization of the H atoms by multiple collisions with coma molecules. The same physical model yielded very good matches between the modeled Lycα isophotes and those observed in both of the two very different images of comet Kohoutek. The production rate was varied in time as implied by the shape of the visual light curve. All other physical parameters were varied only according to their naturally expected heliocentric distance and velocity dependencies. The complete physical description of the inner coma provided by the coupled gas-dynamic/MCPTM calculation was needed to obtain a good fit to the data. The correct inner coma description is important since it provides not only the initial conditions for the photodissociated H atoms but also (and most importantly) the collisional targets for the H atoms produced in the innermost regions of the coma. Simplistic descriptions for the coma (single speed and perfectly radial molecular motion) do not yield realistic isophote contours. The implications of the model results as they apply to other comets, species, and a variety of conditions are also discussed.

Galaxy clusters in the SDSS Stripe 82 based on photometric redshifts

DOE PAGES

Durret, F.; Adami, C.; Bertin, E.; ...

2015-06-10

Based on a recent photometric redshift galaxy catalogue, we have searched for galaxy clusters in the Stripe ~82 region of the Sloan Digital Sky Survey by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune the AMACFI parameters and make the cluster detection as reliable as possible. The same method was applied to the Millennium simulation to estimate our detection efficiency and the approximate masses of the detected clusters. Considering all the cluster galaxies (i.e. within a 1 Mpc radius of the cluster to which they belong and with a photoz differing by less thanmore » 0.05 from that of the cluster), we stacked clusters in various redshift bins to derive colour-magnitude diagrams and galaxy luminosity functions (GLFs). For each galaxy with absolute magnitude brighter than -19.0 in the r band, we computed the disk and spheroid components by applying SExtractor, and by stacking clusters we determined how the disk-to-spheroid flux ratio varies with cluster redshift and mass. We also detected 3663 clusters in the redshift range 0.1513 and a few 10 14 solar masses. Furthermore, by stacking the cluster galaxies in various redshift bins, we find a clear red sequence in the (g'-r') versus r' colour-magnitude diagrams, and the GLFs are typical of clusters, though with a possible contamination from field galaxies. The morphological analysis of the cluster galaxies shows that the fraction of late-type to early-type galaxies shows an increase with redshift (particularly in high mass clusters) and a decrease with detection level, i.e. cluster mass. From the properties of the cluster galaxies, the majority of the candidate clusters detected here seem to be real clusters with typical cluster properties.« less

Galaxy clusters in the SDSS Stripe 82 based on photometric redshifts

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

Durret, F.; Adami, C.; Bertin, E.

Based on a recent photometric redshift galaxy catalogue, we have searched for galaxy clusters in the Stripe ~82 region of the Sloan Digital Sky Survey by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune the AMACFI parameters and make the cluster detection as reliable as possible. The same method was applied to the Millennium simulation to estimate our detection efficiency and the approximate masses of the detected clusters. Considering all the cluster galaxies (i.e. within a 1 Mpc radius of the cluster to which they belong and with a photoz differing by less thanmore » 0.05 from that of the cluster), we stacked clusters in various redshift bins to derive colour-magnitude diagrams and galaxy luminosity functions (GLFs). For each galaxy with absolute magnitude brighter than -19.0 in the r band, we computed the disk and spheroid components by applying SExtractor, and by stacking clusters we determined how the disk-to-spheroid flux ratio varies with cluster redshift and mass. We also detected 3663 clusters in the redshift range 0.1513 and a few 10 14 solar masses. Furthermore, by stacking the cluster galaxies in various redshift bins, we find a clear red sequence in the (g'-r') versus r' colour-magnitude diagrams, and the GLFs are typical of clusters, though with a possible contamination from field galaxies. The morphological analysis of the cluster galaxies shows that the fraction of late-type to early-type galaxies shows an increase with redshift (particularly in high mass clusters) and a decrease with detection level, i.e. cluster mass. From the properties of the cluster galaxies, the majority of the candidate clusters detected here seem to be real clusters with typical cluster properties.« less

Split high-dose oral levothyroxine treatment as a successful therapy option in myxedema coma.

PubMed

Charoensri, Suranut; Sriphrapradang, Chutintorn; Nimitphong, Hataikarn

2017-10-01

High-dose intravenous thyroxine (T4) is the preferable treatment for myxedema coma. We describe the clinical course of a 69-year-old man who presented with myxedema coma and received oral levothyroxine (LT4) therapy (1 mg) in a split dose. This suggests split high-dose oral LT4 as a therapeutic option in myxedema coma.

Large-scale dust jets in the coma of 67P/Churyumov-Gerasimenko as seen by the OSIRIS instrument onboard Rosetta

NASA Astrophysics Data System (ADS)

Lara, L. M.; Lowry, S.; Vincent, J.-B.; Gutiérrez, P. J.; Rożek, A.; La Forgia, F.; Oklay, N.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Agarwal, J.; Auger, A.-T.; A'Hearn, M. F.; Barucci, M. A.; Bertaux, J.-L.; Bertini, I.; Besse, S.; Bodewits, D.; Cremonese, G.; Davidsson, B.; Da Deppo, V.; Debei, S.; De Cecco, M.; El-Maarry, M. R.; Ferri, F.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutiérrez-Marques, P.; Güttler, C.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Knollenberg, J.; Kovacs, G.; Kramm, J.-R.; Kührt, E.; Küppers, M.; Lazzarin, M.; Lin, Z.-Y.; López-Moreno, J. J.; Magrin, S.; Marzari, F.; Michalik, H.; Moissl-Fraund, R.; Moreno, F.; Mottola, S.; Naletto, G.; Pajola, M.; Pommerol, A.; Thomas, N.; Sabau, M. D.; Tubiana, C.

2015-11-01

Context. During the most recent perihelion passage in 2009 of comet 67P/Churyumov-Gerasimenko (67P), ground-based observations showed an anisotropic dust coma where jet-like features were detected at ~ 1.3 AU from the Sun. The current perihelion passage is exceptional as the Rosetta spacecraft is monitoring the nucleus activity since March 2014, when a clear dust coma was already surrounding the nucleus at 4.3 AU from the Sun. Subsequently, the OSIRIS camera also witnessed an outburst in activity between April 27 and 30, and since mid-July, the dust coma at rh ~ 3.7-3.6 AU preperihelion is clearly non-isotropic, pointing to the existence of dust jet-like features. Aims: We aim to ascertain on the nucleus surface the origin of the dust jet-like features detected as early as in mid-July 2014. This will help to establish how the localized comet nucleus activity compares with that seen in previous apparitions and will also help following its evolution as the comet approaches its perihelion, at which phase most of the jets were detected from ground-based observations. Determining these areas also allows locating them in regions on the nucleus with spectroscopic or geomorphological distinct characteristics. Methods: Three series of dust images of comet 67P obtained with the Wide Angle Camera (WAC) of the OSIRIS instrument onboard the Rosetta spacecraft were processed with different enhancement techniques. This was made to clearly show the existence of jet-like features in the dust coma, whose appearance toward the observer changed as a result of the rotation of the comet nucleus and of the changing observing geometry from the spacecraft. The position angles of these features in the coma together with information on the observing geometry, nucleus shape, and rotation, allowed us to determine the most likely locations on the nucleus surface where the jets originate from. Results: Geometrical tracing of jet sources indicates that the activity of the nucleus of 67P gave rise during July and August 2014 to large-scale jet-like features from the Hapi, Hathor, Anuket, and Aten regions, confirming that active regions may be present on the nucleus localized at 60° northern latitude as deduced from previous comet apparitions. There are also hints that large-scale jets observed from the ground are possibly composed, at their place of origin on the nucleus surface, of numerous small-scale features.

The Black Hole Safari: Big Game Hunting in 30+ Massive Galaxies

NASA Astrophysics Data System (ADS)

McConnell, Nicholas J.; Ma, Chung-Pei; Janish, Ryan; Gebhardt, Karl; Lauer, Tod R.; Graham, James R.

2015-01-01

The current census of the most massive black holes in the local universe turns up an odd variety of galaxy hosts: central galaxies in rich clusters, second- or lower-ranked cluster members, and compact relics from the early universe. More extensive campaigns are required to explore the number density and environmental distribution of these monsters. Over the past three years we have collected a large set of stellar kinematic data with sufficient resolution to detect the gravitational signatures of supermassive black holes with MBH > 109 MSun. This Black Hole Safari targets enormous galaxies at the centers of nearby galaxy clusters, as well as their similarly luminous counterparts in weaker galaxy groups. To date we have observed more than 30 early-type galaxies with integral-field spectrographs on the Keck, Gemini North, and Gemini South telescopes. Here I present preliminary stellar kinematics from 10 objects.

Discovery of Main-belt Comet P/2006 VW139 by Pan-STARRS1

NASA Astrophysics Data System (ADS)

Hsieh, Henry H.; Yang, Bin; Haghighipour, Nader; Kaluna, Heather M.; Fitzsimmons, Alan; Denneau, Larry; Novaković, Bojan; Jedicke, Robert; Wainscoat, Richard J.; Armstrong, James D.; Duddy, Samuel R.; Lowry, Stephen C.; Trujillo, Chadwick A.; Micheli, Marco; Keane, Jacqueline V.; Urban, Laurie; Riesen, Timm; Meech, Karen J.; Abe, Shinsuke; Cheng, Yu-Chi; Chen, Wen-Ping; Granvik, Mikael; Grav, Tommy; Ip, Wing-Huen; Kinoshita, Daisuke; Kleyna, Jan; Lacerda, Pedro; Lister, Tim; Milani, Andrea; Tholen, David J.; Vereš, Peter; Lisse, Carey M.; Kelley, Michael S.; Fernández, Yanga R.; Bhatt, Bhuwan C.; Sahu, Devendra K.; Kaiser, Nick; Chambers, K. C.; Hodapp, Klaus W.; Magnier, Eugene A.; Price, Paul A.; Tonry, John L.

2012-03-01

The main-belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short (~10'') antisolar dust tail and a longer (~60'') dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event. Photometry showing the brightness of the near-nucleus coma remaining constant over ~30 days provides further evidence for this object's cometary nature, suggesting it is in fact an MBC, and not a disrupted asteroid. A spectroscopic search for CN emission was unsuccessful, though we find an upper limit CN production rate of Q CN < 1.3 × 1024 mol s-1, from which we infer a water production rate of Q_H_2O<10^{26} mol s-1. We also find an approximately linear optical spectral slope of 7.2%/1000 Å, similar to other cometary dust comae. Numerical simulations indicate that P/2006 VW139 is dynamically stable for >100 Myr, while a search for a potential asteroid family around the object reveals a cluster of 24 asteroids within a cutoff distance of 68 m s-1. At 70 m s-1, this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.

DISCOVERY OF MAIN-BELT COMET P/2006 VW{sub 139} BY Pan-STARRS1

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

Hsieh, Henry H.; Yang Bin; Haghighipour, Nader

2012-03-20

The main-belt asteroid (300163) 2006 VW{sub 139} (later designated P/2006 VW{sub 139}) was discovered to exhibit comet-like activity by the Pan-STARRS1 (PS1) survey telescope using automated point-spread-function analyses performed by PS1's Moving Object Processing System. Deep follow-up observations show both a short ({approx}10'') antisolar dust tail and a longer ({approx}60'') dust trail aligned with the object's orbit plane, similar to the morphology observed for another main-belt comet (MBC), P/2010 R2 (La Sagra), and other well-established comets, implying the action of a long-lived, sublimation-driven emission event. Photometry showing the brightness of the near-nucleus coma remaining constant over {approx}30 days provides furthermore » evidence for this object's cometary nature, suggesting it is in fact an MBC, and not a disrupted asteroid. A spectroscopic search for CN emission was unsuccessful, though we find an upper limit CN production rate of Q{sub CN} < 1.3 Multiplication-Sign 10{sup 24} mol s{sup -1}, from which we infer a water production rate of Q{sub H{sub 2O}}<10{sup 26} mol s{sup -1}. We also find an approximately linear optical spectral slope of 7.2%/1000 A, similar to other cometary dust comae. Numerical simulations indicate that P/2006 VW{sub 139} is dynamically stable for >100 Myr, while a search for a potential asteroid family around the object reveals a cluster of 24 asteroids within a cutoff distance of 68 m s{sup -1}. At 70 m s{sup -1}, this cluster merges with the Themis family, suggesting that it could be similar to the Beagle family to which another MBC, 133P/Elst-Pizarro, belongs.« less

VEGAS-SSS: A VST Programme to Study the Satellite Stellar Systems around Bright Early-type Galaxies

NASA Astrophysics Data System (ADS)

Cantiello, M.; Capaccioli, M.; Napolitano, N.; Grado, A.; Limatola, L.; Paolillo, M.; Iodice, E.; Romanowsky, A. J.; Forbes, D. A.; Raimondo, G.; Spavone, M.; La Barbera, F.; Puzia, T. H.; Schipani, P.

2015-03-01

The VEGAS-SSS programme is devoted to studying the properties of small stellar systems (SSSs) in and around bright galaxies, built on the VLT Survey Telescope early-type galaxy survey (VEGAS), an ongoing guaranteed time imaging survey distributed over many semesters (Principal Investigator: Capaccioli). On completion, the VEGAS survey will have collected detailed photometric information of ~ 100 bright early-type galaxies to study the properties of diffuse light (surface brightness, colours, surface brightness fluctuations, etc.) and the distribution of clustered light (compact ''small'' stellar systems) out to previously unreached projected galactocentric radii. VEGAS-SSS will define an accurate and homogeneous dataset that will have an important legacy value for studies of the evolution and transformation processes taking place in galaxies through the fossil information provided by SSSs.

Particle Sizes in the Coma of Comet 45P/Honda-Mrkos-Pajdušáková from Arecibo Radar Observations

NASA Astrophysics Data System (ADS)

Springmann, Alessondra; Howell, Ellen S.; Harmon, John K.; Lejoly, Cassandra; Rivera-Valentin, Edgard G.; Virkki, Anne; Zambrano-Marin, Luisa F.; Taylor, Patrick A.; Harris, Walter M.; Mueller, Beatrice E. A.; Samarasinha, Nalin H.; Rodriguez Sanchez-Vahamonde, Carolina

2017-10-01

Radar observations of cometary comae can provide information about not only the cross-section of the coma, but also constraints on the particle sizes comprising the coma. Harmon et al. (2011) described analysis of radar observations of comet 103P/Hartley 2 to constrain the sizes of its coma particles, as well as modeling to analyze the particle velocity distribution in the coma and orientation with respect to the sun. Arecibo Observatory planetary radar system observations of comet 45P/Honda-Mrkos-Pajdušáková were obtained 9-16 February 2017 by transmitting a continuous wave of polarized radio waves at the comet. By examining the polarization ratios of the returned signal (whether it has the same sense or opposite sense of the transmitted signal), we can look for non-zero same sense polarization signal. Detectable same sense signal indicates the presence of particles with sizes larger than the Rayleigh transition size criteria, a = λ/2π ≈ 2 cm (for the Arecibo wavelength of 12.6 cm).The observations show strong opposite sense signal return from the comet nucleus, as well as a larger ‘skirt’ of surrounding grains in the coma. Preliminary analysis of this data indicates at least a weak same sense polarized signal, implying a population of grains larger than 2 cm in the coma. The sizes of particles in the coma, compared with the area of the coma, can help us constrain the minimum mass for particles at the Rayleigh size limit in the 45P coma. Further, a detectable grain halo of large particles around 45P would imply significant lofting of grains from the comet nucleus.ReferencesHarmon, John K., et al. "Radar observations of comet 103P/Hartley 2." The Astrophysical Journal Letters 734.1 (2011): L2.

In Situ Space Gas Dynamic Measurements by the ROSINA Comet Pressure Sensor COPS Onboard Rosetta Spacecraft

NASA Astrophysics Data System (ADS)

Tzou, Chia-Yu; Altwegg, Kathrin; Fiethe, Björn; Gasc, Sébastien; Rubin, Martin

2015-04-01

Rosetta is part of the cornerstone missions executed by the European Space Agency. It is the first space mission to orbit and also land on a comet. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The COmet Pressure Sensor (COPS) includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux. The combination of these two gauges makes COPS capable to derive the gas dynamics (velocity and temperature) at the location of the spacecraft. Over several months Rosetta has been carrying out a close study of comet 67P/Churyumov-Gerasimenko. In early August 2014 COPS detected the faint and expanding atmosphere of the comet while it was still outside of 3.5 AU from the Sun. We will present ROSINA COPS observations of the evolution and gas dynamics of the cometary coma following these first observations until spring 2015. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

ORIGIN OF MOLECULAR OXYGEN IN COMET 67P/CHURYUMOV–GERASIMENKO

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

Mousis, O.; Ronnet, T.; Brugger, B.

2016-06-01

Molecular oxygen has been detected in the coma of comet 67P/Churyumov–Gerasimenko with abundances in the 1%–10% range by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis-Double Focusing Mass Spectrometer instrument on board the Rosetta spacecraft. Here we find that the radiolysis of icy grains in low-density environments such as the presolar cloud may induce the production of large amounts of molecular oxygen. We also show that molecular oxygen can be efficiently trapped in clathrates formed in the protosolar nebula (PSN), and that its incorporation as crystalline ice is highly implausible, because this would imply much larger abundances of Armore » and N{sub 2} than those observed in the coma. Assuming that radiolysis has been the only O{sub 2} production mechanism at work, we conclude that the formation of comet 67P/Churyumov–Gerasimenko is possible in a dense and early PSN in the framework of two extreme scenarios: (1) agglomeration from pristine amorphous icy grains/particles formed in ISM and (2) agglomeration from clathrates that formed during the disk’s cooling. The former scenario is found consistent with the strong correlation between O{sub 2} and H{sub 2}O observed in comet 67P/Churyumov-Gerasimenko’s coma while the latter scenario requires that clathrates formed from ISM icy grains that crystallized when entering the PSN.« less

Assessment of refractive astigmatism and simulated therapeutic refractive surgery strategies in coma-like-aberrations-dominant corneal optics.

PubMed

Zhou, Wen; Stojanovic, Aleksandar; Utheim, Tor Paaske

2016-01-01

The aim of the study is to raise the awareness of the influence of coma-like higher-order aberrations (HOAs) on power and orientation of refractive astigmatism (RA) and to explore how to account for that influence in the planning of topography-guided refractive surgery in eyes with coma-like-aberrations-dominant corneal optics. Eleven eyes with coma-like-aberrations-dominant corneal optics and with low lenticular astigmatism (LA) were selected for astigmatism analysis and for treatment simulations with topography-guided custom ablation. Vector analysis was used to evaluate the contribution of coma-like corneal HOAs to RA. Two different strategies were used for simulated treatments aiming to regularize irregular corneal optics: With both strategies correction of anterior corneal surface irregularities (corneal HOAs) were intended. Correction of total corneal astigmatism (TCA) and RA was intended as well with strategies 1 and 2, respectively. Axis of discrepant astigmatism (RA minus TCA minus LA) correlated strongly with axis of coma. Vertical coma influenced RA by canceling the effect of the with-the-rule astigmatism and increasing the effect of the against-the-rule astigmatism. After simulated correction of anterior corneal HOAs along with TCA and RA (strategies 1 and 2), only a small amount of anterior corneal astigmatism (ACA) and no TCA remained after strategy 1, while considerable amount of ACA and TCA remained after strategy 2. Coma-like corneal aberrations seem to contribute a considerable astigmatic component to RA in eyes with coma-like-aberrations dominant corneal optics. If topography-guided ablation is programmed to correct the corneal HOAs and RA, the astigmatic component caused by the coma-like corneal HOAs will be treated twice and will result in induced astigmatism. Disregarding RA and treating TCA along with the corneal HOAs is recommended instead.

Citrullinemia type I, classical variant. Identification of ASS-p~G390R (c.1168G>A) mutation in families of a limited geographic area of Argentina: a possible population cluster.

PubMed

Laróvere, Laura E; Angaroni, Celia J; Antonozzi, Sandra L; Bezard, Miriam B; Shimohama, Mariko; de Kremer, Raquel Dodelson

2009-07-01

Citrullinemia type I (CTLN1) is an urea cycle defect caused by mutations in the argininosuccinate synthetase gene. We report the first identification in Argentina of patients with CTLN1 in a limited geographic area. Molecular analysis in patient/relatives included PCR, sequencing and restriction enzyme assay. The studied families showed the same mutation: ASS~p.G390R, associated with the early-onset/severe phenotype. We postulate a possible population cluster. A program to know the carrier frequency in that population is in progress.

A deep x-ray survey of the Pleiades cluster and the B6-A3 main sequence stars in Orion

NASA Technical Reports Server (NTRS)

Caillault, Jean-Pierre

1993-01-01

We have obtained deep ROSAT images of three regions within the Pleiades open cluster. We have detected 317 X-ray sources in these ROSAT PSPC images, 171 of which we associate with certain probable members of the Pleiades cluster. We detect nearly all Pleiades members with spectral types later than G0 and within 25 arcminutes of our three field centers where our sensitivity is highest. This has allowed us to derive for the first time the luminosity function for the G, K, and M dwarfs of an open cluster without the need to use statistical techniques to account for the presence of upper limits in the data sample. Because of our high X-ray detection frequency down to the faint limit of the optical catalog, we suspect that some of our unidentified X-ray sources are previously unknown, very low-mass members of the Pleiades. A large fraction of the Pleiades members detected with ROSAT have published rotational velocities. Plots of L(sub x)/L(sub bol) versus spectroscopic rotational velocity show tightly correlated 'saturation' type relations for stars with (B - V)(sub O) greater than 0.60. For each of several color ranges, X-ray luminosities rise rapidly with increasing rotation rate until v sin i approximately equals 15 km/s, and then remain essentially flat for rotation rates up to at least v sin i approximately equal to 100 km/s. The dispersion in rotation among low-mass stars in the Pleiades is by far the dominant contributor to the dispersion in L(subx) at a given mass. Only about 35 percent of the B.A. and early F stars in the Pleiades are detected as X-ray sources in our survey. There is no correlation between X-ray flux and rotation for these stars. The X-ray luminosity function for the early-type Pleiades stars appears to be bimodal, with only a few exceptions. We either detect these stars at fluxes in the range found for low-mass stars or we derive X-ray limits below the level found for most Pleiades dwarfs. The X-ray spectra for the early-type Pleiades stars detected by ROSAT are indistinguishable from the spectra of the low-mass Pleiades members. We believe that the simple explanation for this behavior is that the early-type Pleiades stars are not themselves intrinsic X-ray sources and that the X-ray sources and that the X-ray emission actually arises from low-mass companions to these stars.

Observational data needs useful for modeling the coma

NASA Technical Reports Server (NTRS)

Huebner, W. F.; Giguere, P. T.

1981-01-01

A computer model of comet comae is described; results from assumed composition of frozen gases are summarized and compared to coma observations. Restrictions on relative abundance of some frozen constituents are illustrated. Modeling, when tightly coupled to observational data, can be important for comprehensive analysis of observations, for predicting undetected molecular species and for improved understanding of coma and nucleus. To accomplish this, total gas production rates and relative elemental abundances of H:C:N:O:S are needed as a function of heliocentric distance of the comet. Also needed are relative column densitites and column density profiles with well defined diaphragm range and pointing position on the coma. Production rates are less desirable since they are model dependent. Total number (or upper limits) of molecules in the coma and analysis of unidentified spectral lines are needed also.

Influence of coma aberration on aperture averaged scintillations in oceanic turbulence

NASA Astrophysics Data System (ADS)

Luo, Yujuan; Ji, Xiaoling; Yu, Hong

2018-01-01

The influence of coma aberration on aperture averaged scintillations in oceanic turbulence is studied in detail by using the numerical simulation method. In general, in weak oceanic turbulence, the aperture averaged scintillation can be effectively suppressed by means of the coma aberration, and the aperture averaged scintillation decreases as the coma aberration coefficient increases. However, in moderate and strong oceanic turbulence the influence of coma aberration on aperture averaged scintillations can be ignored. In addition, the aperture averaged scintillation dominated by salinity-induced turbulence is larger than that dominated by temperature-induced turbulence. In particular, it is shown that for coma-aberrated Gaussian beams, the behavior of aperture averaged scintillation index is quite different from the behavior of point scintillation index, and the aperture averaged scintillation index is more suitable for characterizing scintillations in practice.

Glasgow Coma Scores, Early Opioids, and Posttraumatic Stress Disorder Among Combat Amputees

DTIC Science & Technology

2014-04-01

icz, Johnson, & Mosely, 2008). Little research has compared how morphine and fentanyl might impact later psychological outcomes such as PTSD. In the...Fox, Saunders, Menk, & Middaugh, 1995). Because the analgesic effect of fentanyl is approximately 100 times more than morphine , the median Level 2...dosages administered to patients for these opioids appeared equivalent for analgesic effectiveness (Fox et al., 1995). Of the morphine -treated pa

Measuring the stellar luminosity function and spatial density profile of the inner 0.5 pc of the Milky Way nuclear star cluster

NASA Astrophysics Data System (ADS)

Do, Tuan; Ghez, Andrea; Lu, Jessica R.; Morris, Mark R.; Yelda, Sylvana; Martinez, Gregory D.; Peter, Annika H. G.; Wright, Shelley; Bullock, James; Kaplinghat, Manoj; Matthews, K.

2012-07-01

We report on measurements of the luminosity function of early (young) and late-type (old) stars in the central 0.5 pc of the Milky Way nuclear star cluster as well as the density profiles of both components. The young (~ 6 Myr) and old stars (> 1 Gyr) in this region provide different physical probes of the environment around a supermassive black hole; the luminosity function of the young stars offers us a way to measure the initial mass function from star formation in an extreme environment, while the density profile of the old stars offers us a probe of the dynamical interaction of a star cluster with a massive black hole. The two stellar populations are separated through a near-infrared spectroscopic survey using the integral-field spectrograph OSIRIS on Keck II behind the laser guide star adaptive optics system. This spectroscopic survey is able to separate early-type (young) and late-type (old) stars with a completeness of 50% at K' = 15.5. We describe our method of completeness correction using a combination of star planting simulations and Bayesian inference. The completeness corrected luminosity function of the early-type stars contains significantly more young stars at faint magnitudes compared to previous surveys with similar depth. In addition, by using proper motion and radial velocity measurements along with anisotropic spherical Jeans modeling of the cluster, it is possible to measure the spatial density profile of the old stars, which has been difficult to constrain with number counts alone. The most probable model shows that the spatial density profile, n(r) propto r-γ, to be shallow with γ = 0.4 ± 0.2, which is much flatter than the dynamically relaxed case of γ = 3/2 to 7/4, but does rule out a 'hole' in the distribution of old stars. We show, for the first time, that the spatial density profile, the black hole mass, and velocity anisotropy can be fit simultaneously to obtain a black hole mass that is consistent with that derived from individual orbits of stars at distances < 1000 AU from the Galactic center.

The Origin of Dwarf Early-Type Galaxies

NASA Astrophysics Data System (ADS)

Toloba, Elisa; Boselli, A.; Gorgas, J.

2013-01-01

The physical mechanisms involved in the formation and evolution of dwarf early-type galaxies (dEs) are not well understood yet. Whether these objects, that outnumber any other class of object in clusters, are the low luminosity extension of massive early-type galaxies, i.e. formed through similar processes, or are a different group of objects possibly formed through the transformation of low luminosity spiral galaxies, is still an open debate. Studying the kinematic properties of dEs is a powerful way to distinguish between these two scenarios. In my PhD, awarded with a Fulbright postdoctoral Fellowship and with the 2011 prize to the best Spanish PhD dissertation in Astronomy, we used this technique to make a spectrophotometric analysis of 18 dEs in the Virgo cluster. I found some differences for these dEs within the cluster. The dEs in the outer parts of Virgo have rotation curves with shapes and amplitudes similar to late-type galaxies of the same luminosity. They are rotationally supported, have disky isophotes, and younger ages than those dEs in the center of Virgo, which are pressure supported, often have boxy isophotes and are older. Ram pressure stripping, which removes the gas of galaxies leaving the stars untouched, explains the properties of the dEs located in the outskirts of Virgo. However, the dEs in the central cluster regions, which have lost their angular momentum, must have suffered a more violent transformation. A combination of ram pressure stripping and harassment is not enough to remove the rotation and the disky structures of these galaxies. I am conducting new analysis with 20 new dEs to throw some light in this direction. I also analysed the Faber-Jackson and the Fundamental Plane relations, and I found that dEs deviate from the trends of massive elliptical galaxies towards the position of dark matter dominated systems such as the dwarf spheroidal satellites of the Milky Way and M31. This indicates that dEs have a non-negligible dark matter fraction within their half light radius, we used these diagrams to quantify this dark matter content, which is ~40%, significantly larger than previously thought for these kind of objects.

Isophote Shapes Of Early-Type Galaxies In Massive Clusters At Z 1 And 0

NASA Astrophysics Data System (ADS)

Mitsuda, Kazuma; Doi, Mamoru; Morokuma, Tomoki; Suzuki, Nao; Yasuda, Naoki; Perlmutter, Saul; Aldering, Greg; Meyers, Joshua

2017-06-01

Dynamics of early-type galaxies (ETGs), whether they are supported by rotation or dispersion, is a clue to understand their assembly history. We compare the isophote shape parameter a4 between z ˜ 1 and 0 as a proxy for dynamics to investigate the epoch at which the dynamical properties are established. We create cluster ETG samples with stellar masses of log(M✽/M⦿) ≥ 10.5 with spectroscopic redshifts. We have 130 ETGs from the Hubble Space Telescope Cluster Supernova Survey for z ˜ 1 and 355 ETGs from the Sloan Digital Sky Survey for z ˜ 0. We find similar dependence of the a4 parameter on the mass at z ˜ 1 and 0; the main population changes from disky (a4 > 0) to boxy (a4 ≤ 0) at a critical mass of log(M✽/M⦿) 11.5 with the massive end dominated by boxy ETGs. The disky ETG fraction is consistent between these redshifts. Although uncertainties are large, the results suggest that the isophote shapes and probably dynamical properties of cluster ETGs are already in place at z > 1 and do not significantly evolve in z < 1, despite significant size evolution. The constant disky fraction imply that the processes responsible for the size evolution is not enough violent to convert the dynamical properties of ETGs.

Study of the coma of comet 67P/Churyumov-Gerasimenko based on the ROSINA/RTOF instrument onboard Rosetta

NASA Astrophysics Data System (ADS)

Hoang, M.; Garnier, P.; Lasue, J.; Reme, H.; Altwegg, K.; Balsiger, H. R.; Bieler, A. M.; Calmonte, U.; Fiethe, B.; Galli, A.; Gasc, S.; Gombosi, T. I.; Jäckel, A.; Mall, U.; Le Roy, L.; Rubin, M.; Tzou, C. Y.; Waite, J. H., Jr.; Wurz, P.

2015-12-01

The ROSETTA spacecraft of ESA is in the environment of comet 67P/Churyumov-Gerasimenko since August 2014. Among the experiments onboard the spacecraft, the ROSINA experiment (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) includes two mass spectrometers (DFMS and RTOF) to analyze the composition of neutrals and ions, and a pressure sensor (COPS) to monitor the density and velocity of neutrals in the coma [1]. We will here analyze and discuss the data of the ROSINA/RTOF instrument during the comet escort phase. The Reflectron-type Time-Of-Flight (RTOF) mass spectrometer possesses a wide mass range and a high temporal resolution [1,2]. It was designed to measure cometary neutral gas as well as cometary ions. A detailed description of the main volatiles (H2O, CO2, CO) dynamics and of the heterogeneities of the coma will then be provided. The influence of various parameters on the coma measurements is investigated on a statistical basis, with the parameters being distance to the comet, heliocentric distance, longitude and latitude of nadir point. Our analysis of the northern hemisphere summer season shows the presence of water vapor mostly in the illuminated northern hemisphere near the neck region with cyclic diurnal variations whereas CO2 was confined to the cold southern hemisphere with a more spatially homogeneous composition, in agreement with previous observations of 67P [2] or Hartley 2 [3]. A comparison will also be provided with the COPS total density and DFMS abundance measurements. [1] Balsiger et al., "ROSINA - Rosetta Orbiter Spectrometer for Ion and Neutral Analysis", Space Sci. Rev., 2007. [2] Scherer et al., "A novel principle for an ion mirror design in time-of-flight mass spectrometry," Int. Jou. Mass Spectr., 2006. [3] Hässig et al., "Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko", Science, 2015. [4] A'Hearn et al., "EPOXI at comet Hartley 2", Science, 2011.

Development and Preliminary Validation of the Coma Arousal Communication Scale.

PubMed

Garin, Julie; Reina, Margot; DeiCas, Paula; Rousseaux, Marc

To develop a Coma Arousal Communication Scale and perform preliminary validation. A group of experts developed a questionnaire to assess communication between patients emerging from coma and caregiver (participation, communication modes, and themes) and the strategies used to facilitate communication. To assess the scale's psychometric characteristics, it was presented to the caregivers of 40 inpatients admitted to 5 coma units and (to obtain reference data) to 29 control participants. The Coma Arousal Communication Scale displayed good intra- and interrater reliability as judged by intraclass correlation coefficients (between 0.76 and 0.98) and Bland and Altman plots. Cohen κ coefficient revealed moderate to almost perfect levels of agreement for most individual items and slight levels for a few items dealing with compensatory strategies. We observed good internal consistency, relations with the Wessex Head Injury Matrix, and sensitivity to change for patients who had sustained brain injury in the previous 6 months. The Coma Arousal Communication Scale provides accurate information about communication skills of individuals emerging from coma. However, some compensatory strategies adopted by caregivers are difficult to characterize.

The relation between persistent coma and brain ischemia after severe brain injury.

PubMed

Cheng, Quan; Jiang, Bing; Xi, Jian; Li, Zhen Yan; Liu, Jin Fang; Wang, Jun Yu

2013-12-01

To investigate the relation between brain ischemia and persistent vegetative state after severe traumatic brain injury. The 66 patients with severe brain injury were divided into two groups: The persistent coma group (coma duration ≥10 d) included 51 patients who had an admission Glasgow Coma Scale (GCS) of 5-8 and were unconscious for more than 10 d. There were 15 patients in the control group, their admission GCS was 5-8, and were unconscious for less than 10 d. The brain areas, including frontal, parietal, temporal, occipital lobes and thalamus, were measured by Single Photon Emission Computed Tomography (SPECT). In the first SPECT scan, multiple areas of cerebral ischemia were documented in all patients in both groups, whereas bilateral thalamic ischemia were presented in all patients in the persistent coma group and were absented in the control group. In the second SPECT scan taken during the period of analepsia, with an indication that unilateral thalamic ischemia were persisted in 28 of 41 patients in persistent coma group(28/41,68.29%). Persistent coma after severe brain injury is associated with bilateral thalamic ischemia.

Coma measurement by transmission image sensor with a PSM

NASA Astrophysics Data System (ADS)

Wang, Fan; Wang, Xiangzhao; Ma, Mingying; Zhang, Dongqing; Shi, Weijie; Hu, Jianming

2005-01-01

As feature size decreases, especially with the use of resolution enhancement technique such as off axis illumination and phase shifting mask, fast and accurate in-situ measurement of coma has become very important in improving the performance of modern lithographic tools. The measurement of coma can be achieved by the transmission image sensor, which is an aerial image measurement device. The coma can be determined by measuring the positions of the aerial image at multiple illumination settings. In the present paper, we improve the measurement accuracy of the above technique with an alternating phase shifting mask. Using the scalar diffraction theory, we analyze the effect of coma on the aerial image. To analyze the effect of the alternating phase shifting mask, we compare the pupil filling of the mark used in the above technique with that of the phase-shifted mark used in the new technique. We calculate the coma-induced image displacements of the marks at multiple partial coherence and NA settings, using the PROLITH simulation program. The simulation results show that the accuracy of coma measurement can increase approximately 20 percent using the alternating phase shifting mask.

Prevalence and risk factors of seizure clusters in adult patients with epilepsy.

PubMed

Chen, Baibing; Choi, Hyunmi; Hirsch, Lawrence J; Katz, Austen; Legge, Alexander; Wong, Rebecca A; Jiang, Alfred; Kato, Kenneth; Buchsbaum, Richard; Detyniecki, Kamil

2017-07-01

In the current study, we explored the prevalence of physician-confirmed seizure clusters. We also investigated potential clinical factors associated with the occurrence of seizure clusters overall and by epilepsy type. We reviewed medical records of 4116 adult (≥16years old) outpatients with epilepsy at our centers for documentation of seizure clusters. Variables including patient demographics, epilepsy details, medical and psychiatric history, AED history, and epilepsy risk factors were then tested against history of seizure clusters. Patients were then divided into focal epilepsy, idiopathic generalized epilepsy (IGE), or symptomatic generalized epilepsy (SGE), and the same analysis was run. Overall, seizure clusters were independently associated with earlier age of seizure onset, symptomatic generalized epilepsy (SGE), central nervous system (CNS) infection, cortical dysplasia, status epilepticus, absence of 1-year seizure freedom, and having failed 2 or more AEDs (P<0.0026). Patients with SGE (27.1%) were more likely to develop seizure clusters than patients with focal epilepsy (16.3%) and IGE (7.4%; all P<0.001). Analysis by epilepsy type showed that absence of 1-year seizure freedom since starting treatment at one of our centers was associated with seizure clustering in patients across all 3 epilepsy types. In patients with SGE, clusters were associated with perinatal/congenital brain injury. In patients with focal epilepsy, clusters were associated with younger age of seizure onset, complex partial seizures, cortical dysplasia, status epilepticus, CNS infection, and having failed 2 or more AEDs. In patients with IGE, clusters were associated with presence of an aura. Only 43.5% of patients with seizure clusters were prescribed rescue medications. Patients with intractable epilepsy are at a higher risk of developing seizure clusters. Factors such as having SGE, CNS infection, cortical dysplasia, status epilepticus or an early seizure onset, can also independently increase one's chance of having seizure clusters. Copyright © 2017. Published by Elsevier B.V.

Myxoedema coma presenting in status epilepticus.

PubMed Central

Woods, K. L.; Holmes, G. K.

1977-01-01

A 71-year-old woman with myxoedema coma presenting in status epilepticus is reported. Although this complication of myxoedema coma is considered to be fatal the patient described responded dramatically to treatment and remains in good health. PMID:876913

Coma blisters in children: case report and review of the literature.

PubMed

Bosco, Laura; Schena, Donatella; Colato, Chiara; Biban, Paolo; Girolomoni, Giampiero

2013-12-01

Coma-induced blisters is a rare condition associated with prolonged impairment of conscious level, which is relatively well-known in adults following overdose with barbiturates. However, it has been very rarely described in children. A case of coma-bullae occurring in an 11-year-old child with meningoencephalitis is herein reported. The bullous lesions occurred on the limbs and trunks, and evolved into necrotic ulcers in a few days. No correlation with any drug overdosage was found. A skin biopsy revealed epidermal and eccrine sweat gland necrosis with abundant neutrophils, and thrombosis of the vessels in the lower dermis. A comprehensive review of the literature showed that only 5 cases of coma-bullae in children have been published so far. Coma blistering resolves spontaneously within days or weeks. Diagnosis of coma-bullae may require careful clinical-pathologic correlation to exclude other blistering diseases in children.

Anions in Cometary Comae

NASA Technical Reports Server (NTRS)

Charnley, Steven B.

2011-01-01

The presence of negative ions (anions) in cometary comae is known from Giotto mass spectrometry of IP/Halley. The anions 0-, OH-, C-, CH- and CN- have been detected, as well as unidentified anions with masses 22-65 and 85-110 amu (Chaizy et al. 1991). Organic molecular anions are known to have a significant impact on the charge balance of interstellar clouds and circumstellar envelopes and have been shown to act as catalysts for the gas-phase synthesis of larger hydrocarbon molecules in the ISM, but their importance in cometary comae has not yet been explored. We present details of the first attempt to model the chemistry of anions in cometary comae. Based on the combined chemical and hydro dynamical model of Rodgers & Charnley (2002), we investigate the role of large carbon-chain anions in cometary coma chemistry. We calculate the effects of these anions on coma thermodynamics, charge balance and examine their impact on molecule formation.

The relationship between pneumonia and Glasgow coma scale assessment on acute stroke patients

NASA Astrophysics Data System (ADS)

Ritarwan, K.; Batubara, C. A.; Dhanu, R.

2018-03-01

Pneumonia is one of the most frequent medical complications of a stroke. Despite the well-documented association of a stroke associated infections with increased mortality and worse long-term outcome, on the other hand, the limited data available on independent predictors of pneumonia in acute stroke patients in an emergency unit. To determine the independentrelationship between pneumonia and Glasgow Coma Scale assessment on acute stroke patients. The cohort retrospective study observed 55 acute stroke patients who stayed in intensive care unit Adam Malik General Hospital from January until August 2017. Pneumonia was more frequent in patients with Ischemic stroke (OR 5.40; 95% CI: 1.28 – 6.40, p=0.003), higher National Institute of Health Stroke Scale (NIHSS) (p=0.014) and lower Glasgow Coma Scale (p=0.0001). Analysis multivariate logistic regression identified NIHSS as an independent of predictors of pneumonia (95% CI : 1.047 – 1.326, p=0.001). Pneumonia was associated with severity and type of stroke and length of hospital stay. The severity of the deficits evaluated by the NIHSS was shown to be the only independent risk factor for pneumonia in acute stroke patients.

Hα Monitoring of Early-Type Emission Line Stars

NASA Astrophysics Data System (ADS)

Souza, Steven P.; Boettcher, E.; Wilson, S.; Hosek, M.

2011-05-01

We have begun a narrowband imaging program to monitor Hα emission in early-type stars in young open clusters and associations. A minority of early-type stars, particularly Be stars, show Hα in emission due to extended atmospheres and non-equilibrium conditions. Emission features commonly vary irregularly over a range of timescales (Porter, J.M. & Rivinus, T., P.A.S.P. 115:1153-1170, 2003). Some of the brightest such stars, e.g. γ Cas, have been spectroscopically monitored for Hα variability to help constrain models of the unstable disk, but there is relatively little ongoing monitoring in samples including fainter stars (Peters, G., Be Star Newsletter 39:3, 2009). Our program uses matched 5nm-wide on-band (656nm) and off-band (645nm) filters, in conjunction with the Hopkins Observatory 0.6-m telescope and CCD camera. Aperture photometry is done on all early-type stars in each frame, and results expressed as on-band to off-band ratios. Though wavelength-dependent information is lost compared with spectroscopy, imaging allows us to observe much fainter (and therefore many more) objects. Observing young clusters, rather than individual target stars, allows us to record multiple known and candidate emission line stars per frame, and provides multiple "normal" reference stars of similar spectral type. Observations began in the summer of 2010. This project has the potential to produce significant amounts of raw data, so a semi-automated data reduction process has been developed, including astrometric and photometric tasks. Early results, including some preliminary light curves and recovery of known Be stars at least as faint as R=13.9, are presented. We gratefully acknowledge support for student research through an REU grant to the Keck Northeast Astronomy Consortium from the National Science Foundation, and from the Division III Research Funding Committee of Williams College.

The Complex Outgassing of Comets and the Resulting Coma, a Direct Simulation Monte-Carlo Approach

NASA Astrophysics Data System (ADS)

Fougere, Nicolas

During its journey, when a comet gets within a few astronomical units of the Sun, solar heating liberates gases and dust from its icy nucleus forming a rarefied cometary atmosphere, the so-called coma. This tenuous atmosphere can expand to distances up to millions of kilometers representing orders of magnitude larger than the nucleus size. Most of the practical cases of coma studies involve the consideration of rarefied gas flows under non-LTE conditions where the hydrodynamics approach is not valid. Then, the use of kinetic methods is required to properly study the physics of the cometary coma. The Direct Simulation Monte-Carlo (DSMC) method is the method of choice to solve the Boltzmann equation, giving the opportunity to study the cometary atmosphere from the inner coma where collisions dominate and is in thermodynamic equilibrium to the outer coma where densities are lower and free flow conditions are verified. While previous studies of the coma used direct sublimation from the nucleus for spherically symmetric 1D models, or 2D models with a day/night asymmetry, recent observations of comets showed the existence of local small source areas such as jets, and extended sources via sublimating icy grains, that must be included into cometary models for a realistic representation of the physics of the coma. In this work, we present, for the first time, 1D, 2D, and 3D models that can take into account the full effects of conditions with more complex sources of gas with jets and/or icy grains. Moreover, an innovative work in a full 3D description of the cometary coma using a kinetic method with a realistic nucleus and outgassing is demonstrated. While most of the physical models used in this study had already been developed, they are included in one self-consistent coma model for the first time. The inclusion of complex cometary outgassing processes represents the state-of-the-art of cometary coma modeling. This provides invaluable information about the coma by refining the understanding of the material that constitutes comets. This helps us to comprehend the process of the Solar System formation, one of the top priority questions in the 2013-2022 Planetary Science Decadal survey.

An Italian case of hereditary myopathy with early respiratory failure (HMERF) not associated with the titin kinase domain R279W mutation.

PubMed

Tasca, Giorgio; Mirabella, Massimiliano; Broccolini, Aldobrando; Monforte, Mauro; Sabatelli, Mario; Biscione, Gian Luca; Piluso, Giulio; Gualandi, Francesca; Tonali, Pietro Attilio; Udd, Bjarne; Ricci, Enzo

2010-11-01

Hereditary myopathy with early respiratory failure (HMERF) is a rare disorder characterized by severe respiratory involvement at onset, muscle weakness starting in the early adulthood, and cytoplasmic bodies with peculiar immunohistochemical reactivity on muscle biopsy. Here we describe a patient who presented with hypercapnic coma at age 32. A detailed light and electron microscopy analysis on muscle biopsy was performed and, together with clinical data, led to the diagnosis. The R279W mutation in the TTN gene was excluded. This report expands the geographical region of incidence and encourages additional studies to clarify the genetic heterogeneity of the condition. Copyright © 2010 Elsevier B.V. All rights reserved.

The Hubble Space Telescope Cluster Supernova Survey. II. The Type la Supernova rate in high-redshift galaxy clusters

DOE PAGES

Barbary, K.; Aldering, G.; Amanullah, R.; ...

2011-12-28

Here we report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 < z < 1.46 from the Hubble Space Telescope Cluster Supernova Survey. This is the first cluster SN Ia rate measurement with detected z > 0.9 SNe. Finding 8 ± 1 cluster SNe Ia, we determine an SN Ia rate of 0.50 +0.23 -0.19 (stat) +0.10 -0.09 (sys) h 2 70 SNuB (SNuB ≡ 10 -12 SNe L -1 ⊙,B yr -1). In units of stellar mass, this translates to 0.36 + 0.16 -0.13 (stat) +0.07 -0.06 (sys) h 2 70 SNuMmore » (SNuM ≡ 10 -12 SNe M –1 ⊙ yr –1). This represents a factor of ≈ 5 ± 2 increase over measurements of the cluster rate at z < 0.2. We parameterize the late-time SN Ia delay time distribution (DTD) with a power law: Ψ(t)∝t s . Under the approximation of a single-burst cluster formation redshift of zf = 3, our rate measurement in combination with lower-redshift cluster SN Ia rates constrains s = –1.41 +0.47 –0.40, consistent with measurements of the DTD in the field. This measurement is generally consistent with expectations for the "double degenerate" scenario and inconsistent with some models for the "single degenerate" scenario predicting a steeper DTD at large delay times. We check for environmental dependence and the influence of younger stellar populations by calculating the rate specifically in cluster red-sequence galaxies and in morphologically early-type galaxies, finding results similar to the full cluster rate. Finally, the upper limit of one hostless cluster SN Ia detected in the survey implies that the fraction of stars in the intra-cluster medium is less than 0.47 (95% confidence), consistent with measurements at lower redshifts.« less

[Translation and Validation of the FOUR Scale for Children and its Use as Outcome Predictor: A Pilot Study].

PubMed

Ferreira, Sofia Simões; Meireles, Daniel; Pinto, Alexandra; Abecasis, Francisco

2017-09-29

The Full Outline of UnResponsiveness - FOUR scale has been previously validated to assess impaired consciousness in the adult population. The aim of this study is the translation into Portuguese and validation of the FOUR scale in the pediatric population. The study also compares the FOUR scale and Glasgow coma scale score ratings and the clinical outcome of patients hospitalized in Pediatric Intensive Care Units. This study prospectively rated patients admitted to the Pediatric Intensive Care Units with impaired consciousness during one year. Both scales were applied daily to patients by three types of examiners: intensivists, residents and nurses, from the moment of admission until clinical discharge. Neurological sequelae was evaluated using the King's Outcome Scale for Childhood Head Injury - KOSCHI. Twenty seven patients between one and 17 years of age were included. Both scales are reliable and inter-rater reliability was greater for the FOUR score. Glasgow coma scale showed a minimum score in eight evaluations, whereas the FOUR scale obtained the minimum score in only two of these evaluations. In both scales there was a strong association between the admission score and the patient's outcome (area under curve FOUR = 0.939, versus Glasgow coma scale = 0.925). The FOUR scale provides more neurological information than Glasgow coma scale in patients with impaired consciousness and has prognostic interest. The FOUR scale can be applied in patients admitted with impaired consciousness in Pediatric Intensive Care Units. We think that a multicenter study would be very beneficial for confirming and generalizing these results.

The mini-CIDEX GC/IMS: Analysis of cometary ice and dust

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Carle, Glenn C.; Humphry, Donald E.; Shao, Maxine; Takeuchi, Nori

1995-01-01

Comets are recognized as among the most scientifically important objects in the solar system. They are presumed relics of the early primitive material in the solar nebula and are believed to have provided a general enrichment of volatiles to the inner solar system. The Cometary Coma Chemical Composition (C4) Mission, a proposed Discovery-Class Mission, will analyze materials released into the coma, providing information leading to the understanding of the chemical composition and make-up of the cometary nucleus. As one of two scientific instruments in the C4 spacecraft, an advanced and streamlined version of the Cometary Ice and Dust Experiment (CIDEX), a mini-CIDEX, will employ an X-Ray Fluorescence (XRF) spectrometer to determine bulk elemental composition of cometary dust grains and a Gas Chromatograph/Ion Mobility Spectrometer (GC/IMS) for determination of the molecular composition of dust and ices following stepwise pyrolysis and combustion. A description of the mini-CIDEX IMS will be provided as well as data from analyses conducted using the mini-CIDEX breadboard instrument.

Long-Term Psychological Health among Individuals Pursuing Emerging Adulthood-Type Pathways in the 1950s and 1960s

PubMed Central

Reifman, Alan; Oblad, Timothy; Niehuis, Sylvia

2016-01-01

We analyzed data from the Wisconsin Longitudinal Study (N = 6390) to investigate how common an emerging adulthood-type lifestyle (e.g., delayed marriage and childbearing, pursuit of higher education) was in the late 1950s and early 1960s, and what the long-term psychological-health correlates were of such a lifestyle. Cluster analyses of marital, childbearing, educational, and occupational variables from 1957 (high school graduation) to 1964 generated six clusters that we labeled: fast-starters (early marriage and childbearing, little education beyond high school, virtually all employed), very-educated/partnered (mean educational attainment well into graduate school and among the earliest to get married), moderately educated/family oriented (mean years of education somewhat shy of a bachelor’s degree, early marriage and childbearing), educated singles (late marriage and childbearing, if at all, averaging a bachelor’s degree; most prototypical of emerging adulthood), work/military first (little education past high school, late marriage and childbearing), and military/professional aspiration (envisioning career requiring college education and pursuing one). The clusters were then compared on health and well-being measures from 1992–93 and 2003–05, controlling for family-of-origin socioeconomic status. In general, individuals whose life pursuits combined higher education, professional career aspirations, and marriage exhibited the best long-term psychological health. Results are discussed in terms of historical conditions when these individuals transitioned to adulthood. PMID:28936106

Coma Associated with Microscopy-Diagnosed Plasmodium vivax: A Prospective Study in Papua, Indonesia

PubMed Central

Hardianto, Setiawan O.; Tjitra, Emiliana; Kenangalem, Enny; Sugiarto, Paulus; Price, Ric N.; Anstey, Nicholas M.

2011-01-01

Background Coma complicates Plasmodium falciparum infection but is uncommonly associated with P. vivax. Most series of vivax coma have been retrospective and have not utilized molecular methods to exclude mixed infections with P. falciparum. Methods We prospectively enrolled patients hospitalized in Timika, Indonesia, with a Glasgow Coma Score (GCS) ≤10 and P. vivax monoinfection on initial microscopy over a four year period. Hematological, biochemical, serological, radiological and cerebrospinal fluid (CSF) examinations were performed to identify other causes of coma. Repeat microscopy, antigen detection and polymerase chain reaction (PCR) were performed to exclude infections with other Plasmodium species. Results Of 24 patients fulfilling enrolment criteria, 5 had clear evidence for other non-malarial etiologies. PCR demonstrated 10 mixed infections and 3 P. falciparum monoinfections. 6 (25%) patients had vivax monoinfection and no apparent alternative cause, with a median GCS of 9 (range 8–10) and a median coma duration of 42 (range 36–48) hours. CSF leukocyte counts were <10/ul (n = 3); 2 of the 3 patients without CSF examination recovered with antimalarial therapy alone. One patient had a tremor on discharge consistent with a post-malarial neurological syndrome. No patient had other organ dysfunction. The only death was associated with pure P. falciparum infection by PCR. Vivax monoinfection-associated risk of coma was estimated at 1 in 29,486 clinical vivax infections with no deaths. In comparison, the risk of falciparum-associated coma was estimated at 1 in 1,276 clinical infections with an 18.5% mortality rate. Conclusions P. vivax-associated coma is rare, occurring 23 times less frequently than that seen with falciparum malaria, and is associated with a high proportion of non-malarial causes and mixed infections using PCR. The pathogenesis of coma associated with vivax malaria, particularly the role of comorbidities, is uncertain and requires further investigation. PMID:21666785

Which EEG patterns in coma are nonconvulsive status epilepticus?

PubMed

Trinka, Eugen; Leitinger, Markus

2015-08-01

Nonconvulsive status epilepticus (NCSE) is common in patients with coma with a prevalence between 5% and 48%. Patients in deep coma may exhibit epileptiform EEG patterns, such as generalized periodic spikes, and there is an ongoing debate about the relationship of these patterns and NCSE. The purposes of this review are (i) to discuss the various EEG patterns found in coma, its fluctuations, and transitions and (ii) to propose modified criteria for NCSE in coma. Classical coma patterns such as diffuse polymorphic delta activity, spindle coma, alpha/theta coma, low output voltage, or burst suppression do not reflect NCSE. Any ictal patterns with a typical spatiotemporal evolution or epileptiform discharges faster than 2.5 Hz in a comatose patient reflect nonconvulsive seizures or NCSE and should be treated. Generalized periodic diacharges or lateralized periodic discharges (GPDs/LPDs) with a frequency of less than 2.5 Hz or rhythmic discharges (RDs) faster than 0.5 Hz are the borderland of NCSE in coma. In these cases, at least one of the additional criteria is needed to diagnose NCSE (a) subtle clinical ictal phenomena, (b) typical spatiotemporal evolution, or (c) response to antiepileptic drug treatment. There is currently no consensus about how long these patterns must be present to qualify for NCSE, and the distinction from nonconvulsive seizures in patients with critical illness or in comatose patients seems arbitrary. The Salzburg Consensus Criteria for NCSE [1] have been modified according to the Standardized Terminology of the American Clinical Neurophysiology Society [2] and validated in three different cohorts, with a sensitivity of 97.2%, a specificity of 95.9%, and a diagnostic accuracy of 96.3% in patients with clinical signs of NCSE. Their diagnostic utility in different cohorts with patients in deep coma has to be studied in the future. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015. Published by Elsevier Inc.

Reye's Syndrome: A Review of Research Studies.

ERIC Educational Resources Information Center

Lopez, Thomas P.; And Others

1982-01-01

Clinical and pathological studies of Reye's syndrome indicate that symptoms range from influenza-related encephalitis-type disease to cranial pressure, cerebral edema, hemorrhage, and coma. Biochemical research on the blood, ammonia, and the liver is increasing in sophistication, and hopes for future insight into the etiology of Reye's syndrome…

The prognostic impact of clinical and CT parameters in patients with pontine hemorrhage.

PubMed

Dziewas, Rainer; Kremer, Marion; Lüdemann, Peter; Nabavi, Darius G; Dräger, Bianca; Ringelstein, Bernd

2003-01-01

In patients with pontine hemorrhage (PH), an accurate prognostic assessment is critical for establishing a reasonable therapeutic approach. The initial clinical symptoms and computed tomography (CT) features were analyzed with multivariate regression analysis in 39 consecutive patients with PH. PHs were classified into three types: (1) large paramedian, (2) basal or basotegmental and (3) lateral tegmental, and the hematomas' diameters were measured. The patients' outcome was evaluated. Twenty-seven patients (69%) died and 12 (31%) survived for more than 1 year after PH. The symptom most predictive of death was coma on admission. The large paramedian type of PH predicted a poor prognosis, whereas the lateral tegmental type was associated with a favorable outcome. The transverse hematoma diameter was also related to outcome, with the threshold value found to be 20 mm. We conclude that PH outcome can be estimated best by combining the CT parameters 'large paramedian PH' and 'transverse diameter >/=20 mm' with the clinical variable 'coma on admission'. Survival is unlikely if all 3 features are present, whereas survival may be expected if only 1 or none of these features is found. Copyright 2003 S. Karger AG, Basel

Open clusters in Auriga OB2

NASA Astrophysics Data System (ADS)

Marco, Amparo; Negueruela, Ignacio

2016-06-01

We study the area around the H II region Sh 2-234, including the young open cluster Stock 8, to investigate the extent and definition of the association Aur OB2 and the possible role of triggering in massive cluster formation. We obtained Strömgren and J, H, KS photometry for Stock 8 and Strömgren photometry for two other cluster candidates in the area, which we confirm as young open clusters and name Alicante 11 and Alicante 12. We took spectroscopy of ˜33 early-type stars in the area, including the brightest cluster members. We calculate a common distance of 2.80^{+0.27}_{-0.24} kpc for the three open clusters and surrounding association. We derive an age 4-6 Ma for Stock 8, and do not find a significantly different age for the other clusters or the association. The star LS V +34°23, with spectral type O8 II(f), is likely the main source of ionization of Sh 2-234. We observe an important population of pre-main-sequence stars, some of them with discs, associated with the B-type members lying on the main sequence. We interpret the region as an area of recent star formation with some residual and very localized ongoing star formation. We do not find evidence for sequential star formation on a large scale. The classical definition of Aur OB2 has to be reconsidered, because its two main open clusters, Stock 8 and NGC 1893, are not at the same distance. Stock 8 is probably located in the Perseus arm, but other nearby H II regions whose distances also place them in this arm show quite different distances and radial velocities and, therefore, are not connected.

An Atypical Case of Myxedema Coma with Concomitant Nonconvulsive Seizure.

PubMed

Patel, Pratik; Bekkerman, Mikhael; Varallo-Rodriguez, Cristina; Rampersaud, Rajendra

2016-01-01

Hypothyroidism is a prevalent condition in the general population that is treatable with appropriately dosed thyroid hormone replacement medication. Infrequently, patients will present with myxedema coma, characterized by hypothermia, hypotension, bradycardia, and altered mental status in the setting of severe hypothyroidism. Myxedema coma has also been known to manifest in a number of unusual and dangerous forms. Here, we present the case of a woman we diagnosed with an uncharacteristic expression of myxedema coma and nonconvulsive seizure complicated by a right middle cerebral artery infarct.

The child in coma

NASA Technical Reports Server (NTRS)

Lewinn, E. B.

1978-01-01

Children in coma continue to pose medical, social, economic, ethical, moral, and legal problems. Modern life-support technology has aggravated these problems. Coma is viewed as a pathological state of unconsciousness from which the patient has not achieved arousal, and which calls for vigorous action to help him regain consciousness. There are two variables that have an especially important bearing on the ability to achieve arousal. These are: the character of the brain injury that caused the coma, and environmental factors that affect the patient after the injury.

[Evaluation of prognosis in purulent meningitis-myelitis based on the Glasgow Coma Scale].

PubMed

Garlicki, A; Caban, J; Bociaga, M; Krukowiecki, J; Warunek, W; Skwara, P

1996-01-01

We presented data from the investigation of the usefulness of the Glasgow Coma Scale in predicting the outcome of bacterial meningitis. Patients who aggregated high Glasgow Coma Scale scores had a good prognosis, whereas those patients with low scores had a very poor prognosis, inspite of this limitation the Glasgow Coma Scale seems to be a valuable supplement to the physical examination of patients with bacterial meningitis and may help in predicting the outcome of the disease.

Initial Diagnosis and Management of Coma.

PubMed

Traub, Stephen J; Wijdicks, Eelco F

2016-11-01

Coma represents a true medical emergency. Drug intoxications are a leading cause of coma; however, other metabolic disturbances and traumatic brain injury are also common causes. The general emergency department approach begins with stabilization of airway, breathing, and circulation, followed by a thorough physical examination to generate a limited differential diagnosis that is then refined by focused testing. Definitive treatment is ultimately disease-specific. This article presents an overview of the pathophysiology, causes, examination, and treatment of coma. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of 1,5-anhydro-d-glucitol in clinical and forensic urine samples.

PubMed

Sydow, Konrad; Wiedfeld, Christopher; Musshoff, Frank; Madea, Burkhard; Tschoepe, Diethelm; Stratmann, Bernd; Hess, Cornelius

2018-06-01

Because of the lack of characteristic morphological findings post mortem diagnosis of diabetes mellitus and identification of diabetic coma can be complicated. 1,5-Anhydroglucitol (1,5-AG), the 1-deoxy form of glucose, competes with glucose for renal reabsorption. Therefore low serum concentrations of 1,5-AG, reflect hyperglycemic excursions over the prior 1-2 weeks in diabetic patients. Next to clinical applications determination of 1,5-AG can also be used in forensic analysis. To investigate the elimination of 1,5-AG, a liquid chromatographic-mass spectrometric method for the determination of 1,5-AG and creatinine in urine was developed and validated according to international guidelines. To evaluate ante mortem concentrations of 1,5-AG spot urine samples of 30 healthy subjects, 46 type 1 and 46 type 2 diabetic patients were analyzed. 1,5-AG urine concentrations of diabetic patients were significantly (p<0.001) lower (mean: 1.54μg/ml, n=92) compared to concentrations of healthy subjects (mean: 4.76μg/ml, n=30) which led to the idea that 1,5-AG urine concentrations post mortem might help in the interpretation of a diabetic coma post mortem. Urine of 47 deceased non-diabetics, 37 deceased diabetic and 9 cases of diabetic coma were measured. Comparison of blood and urine 1,5-AG concentrations in clinic samples (linear, R 2 =0.13) and forensic samples (linear, R 2 =0.02) showed no correlation. Urinary levels of 1,5-AG in deceased diabetic (mean 6.9μg/ml) and in non-diabetic patients (mean 6.3μg/ml) did not show a significant difference (p=0.752). However, urinary 1,5-AG concentrations in deceased due to diabetic coma (mean: 1.7μg/ml) were significantly lower than in non-diabetic (mean: 6.3μg/ml, p=0.039) and lower than in diabetic cases (mean: 4.7μg/ml, p=0.058). The determination of a reliable cut-off for the differentiation of diabetic to diabetic coma cases was not possible. Normalization of urinary 1,5-AG concentrations with the respective creatinine concentrations did not show any gain of information. In clinical (serum) and forensic blood samples a significant difference between all groups could be detected (p<0.05). Comparison of blood and urine 1,5-AG concentrations in clinical samples (linear, R 2 =0.13) and forensic samples (linear, R 2 =0.02) showed no correlation. Copyright © 2018 Elsevier B.V. All rights reserved.

Neuroanatomical Predictors of Awakening in Acutely Comatose Patients

PubMed Central

Kowalski, Robert G.; Buitrago, Manuel M.; Duckworth, Josh; Chonka, Zachary D.; Puttgen, H. Adrian; Stevens, Robert D.; Geocadin, Romergryko G.

2016-01-01

Objective Lateral brain displacement has been associated with loss of consciousness and poor outcome in a range of acute neurologic disorders. We studied the association between lateral brain displacement and awakening from acute coma. Methods This prospective observational study included all new onset coma patients admitted to the Neurosciences Critical Care Unit (NCCU) over 12 consecutive months. Head computed tomography (CT) scans were analyzed independently at coma onset, after awakening, and at follow-up. Primary outcome measure was awakening, defined as the ability to follow commands before hospital discharge. Secondary outcome measures were discharge Glasgow Coma Scale (GCS), modified Rankin Scale, Glasgow Outcome Scale, and hospital and NCCU lengths of stay. Results Of the 85 patients studied, the mean age was 58 ± 16 years, 51% were female, and 78% had cerebrovascular etiology of coma. Fifty-one percent of patients had midline shift on head CT at coma onset and 43 (51%) patients awakened. In a multivariate analysis, independent predictors of awakening were younger age (odds ratio [OR] = 1.039, 95% confidence interval [CI] = 1.002–1.079, p = 0.040), higher GCS score at coma onset (OR = 1.455, 95% CI = 1.157–1.831, p = 0.001), nontraumatic coma etiology (OR = 4.464, 95% CI = 1.011–19.608, p = 0.048), lesser pineal shift on follow-up CT (OR = 1.316, 95% CI = 1.073–1.615, p = 0.009), and reduction or no increase in pineal shift on follow-up CT (OR = 11.628, 95% CI = 2.207–62.500, p = 0.004). Interpretation Reversal and/or limitation of lateral brain displacement are associated with acute awakening in comatose patients. These findings suggest objective parameters to guide prognosis and treatment in patients with acute onset of coma. PMID:25628166

Acute Kidney Injury as a Risk Factor for Delirium and Coma during Critical Illness.

PubMed

Siew, Edward D; Fissell, William H; Tripp, Christina M; Blume, Jeffrey D; Wilson, Matthew D; Clark, Amanda J; Vincz, Andrew J; Ely, E Wesley; Pandharipande, Pratik P; Girard, Timothy D

2017-06-15

Acute kidney injury may contribute to distant organ dysfunction. Few studies have examined kidney injury as a risk factor for delirium and coma. To examine whether acute kidney injury is associated with delirium and coma in critically ill adults. In a prospective cohort study of intensive care unit patients with respiratory failure and/or shock, we examined the association between acute kidney injury and daily mental status using multinomial transition models adjusting for demographics, nonrenal organ failure, sepsis, prior mental status, and sedative exposure. Acute kidney injury was characterized daily using the difference between baseline and peak serum creatinine and staged according to Kidney Disease Improving Global Outcomes criteria. Mental status (normal vs. delirium vs. coma) was assessed daily with the Confusion Assessment Method for the ICU and Richmond Agitation-Sedation Scale. Among 466 patients, stage 2 acute kidney injury was a risk factor for delirium (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.07-2.26) and coma (OR, 2.04; 95% CI, 1.25-3.34) as was stage 3 injury (OR for delirium, 2.56; 95% CI, 1.57-4.16) (OR for coma, 3.34; 95% CI, 1.85-6.03). Daily peak serum creatinine (adjusted for baseline) values were also associated with delirium (OR, 1.35; 95% CI, 1.18-1.55) and coma (OR, 1.44; 95% CI, 1.20-1.74). Renal replacement therapy modified the association between stage 3 acute kidney injury and daily peak serum creatinine and both delirium and coma. Acute kidney injury is a risk factor for delirium and coma during critical illness.

Intranasal post-cardiac arrest treatment with orexin-A facilitates arousal from coma and ameliorates neuroinflammation.

PubMed

Modi, Hiren R; Wang, Qihong; Gd, Sahithi; Sherman, David; Greenwald, Elliot; Savonenko, Alena V; Geocadin, Romergryko G; Thakor, Nitish V

2017-01-01

Cardiac arrest (CA) entails significant risks of coma resulting in poor neurological and behavioral outcomes after resuscitation. Significant subsequent morbidity and mortality in post-CA patients are largely due to the cerebral and cardiac dysfunction that accompanies prolonged whole-body ischemia post-CA syndrome (PCAS). PCAS results in strong inflammatory responses including neuroinflammation response leading to poor outcome. Currently, there are no proven neuroprotective therapies to improve post-CA outcomes apart from therapeutic hypothermia. Furthermore, there are no acceptable approaches to promote cortical or cognitive arousal following successful return of spontaneous circulation (ROSC). Hypothalamic orexinergic pathway is responsible for arousal and it is negatively affected by neuroinflammation. However, whether activation of the orexinergic pathway can curtail neuroinflammation is unknown. We hypothesize that targeting the orexinergic pathway via intranasal orexin-A (ORXA) treatment will enhance arousal from coma and decrease the production of proinflammatory cytokines resulting in improved functional outcome after resuscitation. We used a highly validated CA rat model to determine the effects of intranasal ORXA treatment 30-minute post resuscitation. At 4hrs post-CA, the mRNA levels of proinflammatory markers (IL1β, iNOS, TNF-α, GFAP, CD11b) and orexin receptors (ORX1R and ORX2R) were examined in different brain regions. CA dramatically increased proinflammatory markers in all brain regions particularly in the prefrontal cortex, hippocampus and hypothalamus. Post-CA intranasal ORXA treatment significantly ameliorated the CA-induced neuroinflammatory markers in the hypothalamus. ORXA administration increased production of orexin receptors (ORX1R and ORX2R) particularly in hypothalamus. In addition, ORXA also resulted in early arousal as measured by quantitative electroencephalogram (EEG) markers, and recovery of the associated behavioral neurologic deficit scale score (NDS). Our results indicate that intranasal delivery of ORXA post-CA has an anti-inflammatory effect and accelerates cortical EEG and behavioral recovery. Beneficial outcomes from intranasal ORXA treatment lay the groundwork for therapeutic clinical approach to treating post-CA coma.

Constraining the Volatile Composition and Coma Photochemistry in Jupiter Family Comet 41P/Tuttle-Giacobini-Kresak with High Resolution IR and Optical Spectroscopy

NASA Astrophysics Data System (ADS)

McKay, Adam; DiSanti, Michael A.; Cochran, Anita L.; Dello Russo, Neil; Bonev, Boncho P.; Vervack, Ronald J.; Gibb, Erika L.; Roth, Nathan X.; Kawakita, Hideyo

2017-10-01

Over the past 20 years optical and IR spectroscopy of cometary comae has expanded our understanding both of cometary volatile composition and coma photochemistry. However, these observations tend to be biased towards Nearly Isotropic Comets (NIC's) from the Oort Cloud, rather than the generally fainter and less active Jupiter Family Comets (JFC's) that are thought to originate from the Scattered Disk. However, early 2017 provided a rare opportunity to study several JFC's. We present preliminary results from IR and optical spectroscopy of JFC 41P/Tuttle-Giacobini-Kresak obtained during its 2017 apparition. IR spectra were obtained with the NIRSPEC instrument on Keck II and the new iSHELL spectrograph on NASA IRTF. High spectral resolution optical spectra were obtained with the Tull Coude spectrograph on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory. We will discuss mixing ratios of HCN, NH3, C2H6, C2H2, H2CO, and CH3OH compared to H2O and compare these to previous observations of comets. Preliminary results from the NIRSPEC observations indicate that 41P has typical C2H2 and HCN abundances compared to other JFC's, while the C2H6 abundance is similar to that of NIC's, but is enriched compared to other JFC's. H2CO appears to be heavily depleted in 41P. Analysis of the iSHELL spectra is underway and we will include results from these observations, which complement those from NIRSPEC and extend the scope or our compositional study by measuring additional molecules. We will also present abundances for CN, C2, NH2, C3, and CH obtained from the optical spectra and discuss the implications for the coma photochemistry.This work is supported by the NASA Postdoctoral Program, administered by the Universities Space Research Association, with additional funding from the NSF and NASA PAST.

Constraining the Volatile Composition and Coma Photochemistry in Jupiter Family Comet 41P/Tuttle-Giacobini-Kresak with High Resolution IR and Optical Spectroscopy

NASA Astrophysics Data System (ADS)

McKay, Adam; DiSanti, Michael; Cochran, Anita; Dello Russo, Neil; Bonev, Boncho; Vervack, Ronald; Gibb, Erika; Roth, Nathan; Kawakita, Hideyo

2018-01-01

Over the past 20 years optical and IR spectroscopy of cometary comae has expanded our understanding both of cometary volatile composition and coma photochemistry. However, these observations tend to be biased towards Nearly Isotropic Comets (NIC'S) from the Oort Cloud, rather than the generally fainter and less active Jupiter Family Comets (JFC's) that are thought to originate from the Scattered Disk. However, early 2017 provided a rare opportunity to study several JFC's. We present preliminary results from IR and optical spectroscopy of JFC 41P/Tuttle-Giacobini-Kresak obtained during its 2017 apparition. IR spectra were obtained with the NIRSPEC instrument on Keck II and the new iSHELL spectrograph on NASA IRTF. High spectral resolution optical spectra were obtained with the Tull Coude spectrograph on the 2.7-meter Harlan J. Smith Telescope at McDonald Observatory. We will discuss mixing ratios of HCN, NH3, C2H6, C2H2, H2CO, and CH3OH compared to H2O and compare these to previous observations of comets. Preliminary results from the NIRSPEC observations indicate that 41P has typical C2H2 and HCN abundances compared to other JFC's, while the C2H6 abundance is similar to that of NIC's, but is enriched compared to other JFC's. H2CO appears to be heavily depleted in 41P. Analysis of the iSHELL spectra is underway and we will include results from these observations, which complement those from NIRSPEC and extend the scope or our compositional study by measuring additional molecules. We will also present abundances for CN, C2, NH2, C3, and CH obtained from the optical spectra and discuss the implications for the coma photochemistry.This work is supported by the NASA Postdoctoral Program, administered by the Universities Space Research Association, with additional funding from the NSF and NASA PAST.

Myxedema coma with cardiac tamponade and severe cardiomyopathy.

PubMed

Majid-Moosa, Abdulla; Schussler, Jeffrey M; Mora, Adan

2015-10-01

Myxedema coma is an infrequent but potentially fatal complication of hypothyroidism. We present a rare case of previously undiagnosed hypothyroidism presenting in cardiogenic shock from pericardial tamponade and depressed myocardial contractility in myxedema coma. Here, we focus on cardiovascular complications associated with the condition.

Modeling the coma of 2060 Chiron

NASA Technical Reports Server (NTRS)

Boice, D. C.; Konno, I.; Stern, S. Alan; Huebner, W. F.

1991-01-01

Observations of comet-like activity and a resolved coma have established that 2060 Chiron is a comet. Determinations of its radius range from 65 to 200 km. This unusually large size for a comet suggests that the atmosphere of Chiron is intermediate to the tightly bound, thin atmospheres typical of planets and satellite and the greatly extended atmospheres in free expansion typical of cometary comae. Under certain conditions it may gravitationally bind an atmosphere that is thick compared to its size, while a significant amount of gas escapes to an extensive exosphere. These attributes coupled with reports of sporadic outbursts at large heliocentric distances and the identification of CN in the coma make Chiron a challenging object to model. Simple models of gas production and the dusty coma were recently presented but a general concensus on many basic features has not emerged. Development was begun on a more complete coma model of Chiron. The objectives are to report progress on this model and give the preliminary results for understanding Chiron.

Isolated ellipticals and their globular cluster systems. III. NGC 2271, NGC 2865, NGC 3962, NGC 4240, and IC 4889

NASA Astrophysics Data System (ADS)

Salinas, R.; Alabi, A.; Richtler, T.; Lane, R. R.

2015-05-01

As tracers of star formation, galaxy assembly, and mass distribution, globular clusters have provided important clues to our understanding of early-type galaxies. But their study has been mostly constrained to galaxy groups and clusters where early-type galaxies dominate, leaving the properties of the globular cluster systems (GCSs) of isolated ellipticals as a mostly uncharted territory. We present Gemini-South/GMOS g'i' observations of five isolated elliptical galaxies: NGC 3962, NGC 2865, IC 4889, NGC 2271, and NGC 4240. Photometry of their GCSs reveals clear color bimodality in three of them, but remains inconclusive for the other two. All the studied GCSs are rather poor with a mean specific frequency SN ~ 1.5, independently of the parent galaxy luminosity. Considering information from previous work as well, it is clear that bimodality and especially the presence of a significant, even dominant, population of blue clusters occurs at even the most isolated systems, which casts doubts on a possible accreted origin of metal-poor clusters, as suggested by some models. Additionally, we discuss the possible existence of ultra-compact dwarfs around the isolated elliptical NGC 3962. Based 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), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).Globular cluster photometry is available in electronic form 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/577/A59Appendices are available in electronic form at http://www.aanda.org

Up-regulation of brain cytokines and chemokines mediates neurotoxicity in early acute liver failure by a mechanism independent of microglial activation.

PubMed

Faleiros, Bruno E; Miranda, Aline S; Campos, Alline C; Gomides, Lindisley F; Kangussu, Lucas M; Guatimosim, Cristina; Camargos, Elizabeth R S; Menezes, Gustavo B; Rachid, Milene A; Teixeira, Antônio L

2014-08-26

The neurological involvement in acute liver failure (ALF) is characterized by arousal impairment with progression to coma. There is a growing body of evidence that neuroinflammatory mechanisms play a role in this process, including production of inflammatory cytokines and microglial activation. However, it is still uncertain whether brain-derived cytokines and glial cells are crucial to the pathophysiology of ALF at the early stage, before coma development. Here, we investigated the influence of cytokines and microglia in ALF-induced encephalopathy in mice as soon as neurological symptoms were identifiable. Behavior was assessed at 12, 24, 36 and 48 h post-injection of thioacetamide, a hepatotoxic drug, through locomotor activity by an open field test. Brain concentration of cytokines (TNF-α and IL-1β) and chemokines (CXCL1, CCL2, CCL3 and CCL5) were assessed by ELISA. Microglial activation in brain sections was investigated through immunohistochemistry, and cellular ultrastructural changes were observed by transmission electron microscopy. We found that ALF-induced animals presented a significant decrease in locomotor activity at 24 h, which was accompanied by an increase in IL-1β, CXCL1, CCL2, CCL3 and CCL5 in the brain. TNF-α level was significantly increased only at 36 h. Despite marked morphological changes in astrocytes and brain endothelial cells, no microglial activation was observed. These findings suggest an involvement of brain-derived chemokines and IL-1β in early pathophysiology of ALF by a mechanism independent of microglial activation. Copyright © 2014 Elsevier B.V. All rights reserved.

Energy expenditure during barbiturate coma.

PubMed

Ashcraft, Christine M; Frankenfield, David C

2013-10-01

Barbiturate coma may have a significant effect on metabolic rate, but the phenomenon is not extensively studied. The primary purpose of the current study was to compare the metabolic rate of general critical care patients with those requiring barbiturate coma. A secondary purpose was to evaluate the accuracy of the Penn State prediction equation between these 2 groups of patients. Indirect calorimetry was used to measure the resting metabolic rate of mechanically ventilated, critically ill patients in a barbiturate coma and those of similar height, weight, and age but not in a barbiturate coma. Measurements of resting metabolic rate were compared with predictions using the Penn State equation accounting for body size, body temperature, and minute ventilation. The barbiturate coma group had a lower resting metabolic rate than the control group that remained lower even after adjustment for predicted healthy metabolic rate and maximum body temperature (1859 ± 290 vs 2037 ± 289 kcal/d, P = .020). When minute ventilation was also included in the analysis, the resting metabolic rate between the groups became statistically insignificant (1929 ± 229 vs 2023 ± 226 kcal/d, P = .142). The Penn State equation, which uses these variables, was accurate in 73% of the control patients and also the barbiturate coma patients. Resting metabolic rate is moderately reduced in barbiturate coma, but the decrease is out of proportion with changes in body temperature. However, if both body temperature and minute ventilation are considered, then the change is predictable.

Decompressive craniectomy or medical management for refractory intracranial hypertension: an AAST-MIT propensity score analysis.

PubMed

Nirula, Ram; Millar, D; Greene, Tom; McFadden, Molly; Shah, Lubdha; Scalea, Thomas M; Stein, Deborah M; Magnotti, Louis J; Jurkovich, Gregory J; Vercruysse, Gary; Demetriades, Demetrios; Scherer, Lynette A; Peitzman, Andrew; Sperry, Jason; Beauchamp, Kathryn; Bell, Scott; Feiz-Erfan, Iman; O'Neill, Patrick; Coimbra, Raul

2014-04-01

Moderate/severe traumatic brain injury (TBI) management involves minimizing cerebral edema to maintain brain oxygen delivery. While medical therapy (MT) consisting of diuresis, hyperosmolar therapy, ventriculostomy, and barbiturate coma is the standard of care, decompressive craniectomy (DC) for refractory intracranial hypertension (ICH) has gained renewed interest. Since TBI treatment guidelines consider DC a second-tier intervention after MT failure, we sought to determine if early DC (<48 hours) was associated with improved survival in patients with refractory ICH. Eleven Level 1 trauma centers provided clinical data and head computed tomographic scans for patients with a Glasgow Coma Scale (GCS) score of 13 or less and radiographic evidence of TBI excluding deaths within 48 hours. Computed tomographic scans were graded according to the Marshall classification. A propensity score to receive DC (regardless of whether DC was performed) was calculated for each patient based on patient characteristics, physiology, injury severity, GCS, severity of intracranial injury, and treatment center. Patients who actually received a DC were matched to patients with similar propensity scores who received MT for analysis. Outcomes were compared between early (<48 hours of injury) primary or secondary DC and matched controls and then between early primary DC only and matched controls. There were 2,602 patients who met the inclusion criteria ,of whom 264 (10.1%) received DC (either primary or secondary to another cranial procedure) and 109 (5%) had a DC that was primary. Variables associated with performing a DC included sex, race, intracranial pressure monitor placement, in-house trauma attending, traumatic subarachnoid hemorrhage, midline shift, and basal cistern compression. There was no survival benefit with early primary DC compared with the controls (relative risk, 1.07; 95% confidence interval, 0.67-1.73; p = 0.77), and resource use was higher. Early DC does not seem to significantly improve mortality in patients with refractory ICH compared with MT. Neurosurgeons should pause before entertaining this resource-demanding form of therapy. Therapeutic care/management, level III.

Star-Forming Galaxies in the Hercules Cluster: Hα Imaging of A2151

NASA Astrophysics Data System (ADS)

Cedrés, Bernabé; Iglesias-Páramo, Jorge; Vílchez, José Manuel; Reverte, Daniel; Petropoulou, Vasiliki; Hernández-Fernández, Jonathan

2009-09-01

This paper presents the first results of an Hα imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in Hα, from which 41 were classified as secure members of the cluster and 2 as likely members based on spectroscopic and photometric redshift considerations. The remaining seven galaxies were classified as background contaminants and thus excluded from our study on the Hα properties of the cluster. The morphologies of the 43 Hα selected galaxies range from grand design spirals and interacting galaxies to blue compacts and tidal dwarfs or isolated extragalactic H II regions, spanning a range of magnitudes of -21 <= MB <= -12.5 mag. From these 43 galaxies, 7 have been classified as active galactic nucleus (AGN) candidates. These AGN candidates follow the L(Hα) versus MB relationship of the normal galaxies, implying that the emission associated with the nuclear engine has a rather secondary impact on the total Hα emission of these galaxies. A comparison with the clusters Coma and A1367 and a sample of field galaxies has shown the presence of cluster galaxies with L(Hα) lower than expected for their MB , a consequence of the cluster environment. This fact results in differences in the L(Hα) versus EW(Hα) and L(Hα) distributions of the clusters with respect to the field, and in cluster-to-cluster variations of these quantities, which we propose are driven by a global cluster property as the total mass. In addition, the cluster Hα emitting galaxies tend to avoid the central regions of the clusters, again with different intensity depending on the cluster total mass. For the particular case of A2151, we find that most Hα emitting galaxies are located close to the regions with the higher galaxy density, offset from the main X-ray peak. Overall, we conclude that both the global cluster environment and the cluster merging history play a non-negligible role in the integral star formation properties of clusters of galaxies.

STAR-FORMING GALAXIES IN THE HERCULES CLUSTER: H{alpha} IMAGING OF A2151

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

Cedres, Bernabe; Iglesias-Paramo, Jorge; VIlchez, Jose Manuel

2009-09-15

This paper presents the first results of an H{alpha} imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in H{alpha}, from which 41 were classified as secure members of the cluster and 2 as likely members based on spectroscopic and photometric redshift considerations. The remaining seven galaxies were classified as background contaminants and thus excluded from our study on the H{alpha} properties of the cluster. The morphologies of the 43 H{alpha} selected galaxies range from grand design spirals and interacting galaxies to blue compacts and tidal dwarfs or isolated extragalacticmore » H II regions, spanning a range of magnitudes of -21 {<=} M{sub B} {<=} -12.5 mag. From these 43 galaxies, 7 have been classified as active galactic nucleus (AGN) candidates. These AGN candidates follow the L(H{alpha}) versus M{sub B} relationship of the normal galaxies, implying that the emission associated with the nuclear engine has a rather secondary impact on the total H{alpha} emission of these galaxies. A comparison with the clusters Coma and A1367 and a sample of field galaxies has shown the presence of cluster galaxies with L(H{alpha}) lower than expected for their M{sub B} , a consequence of the cluster environment. This fact results in differences in the L(H{alpha}) versus EW(H{alpha}) and L(H{alpha}) distributions of the clusters with respect to the field, and in cluster-to-cluster variations of these quantities, which we propose are driven by a global cluster property as the total mass. In addition, the cluster H{alpha} emitting galaxies tend to avoid the central regions of the clusters, again with different intensity depending on the cluster total mass. For the particular case of A2151, we find that most H{alpha} emitting galaxies are located close to the regions with the higher galaxy density, offset from the main X-ray peak. Overall, we conclude that both the global cluster environment and the cluster merging history play a non-negligible role in the integral star formation properties of clusters of galaxies.« less

HUBBLE SPACE TELESCOPE AND HI IMAGING OF STRONG RAM PRESSURE STRIPPING IN THE COMA SPIRAL NGC 4921: DENSE CLOUD DECOUPLING AND EVIDENCE FOR MAGNETIC BINDING IN THE ISM

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

Kenney, Jeffrey D. P.; Abramson, Anne; Bravo-Alfaro, Hector, E-mail: jeff.kenney@yale.edu

Remarkable dust extinction features in the deep Hubble Space Telescope (HST) V and I images of the face-on Coma cluster spiral galaxy NGC 4921 show in unprecedented ways how ram pressure strips the ISM from the disk of a spiral galaxy. New VLA HI maps show a truncated and highly asymmetric HI disk with a compressed HI distribution in the NW, providing evidence for ram pressure acting from the NW. Where the HI distribution is truncated in the NW region, HST images show a well-defined, continuous front of dust that extends over 90° and 20 kpc. This dust front separatesmore » the dusty from dust-free regions of the galaxy, and we interpret it as galaxy ISM swept up near the leading side of the ICM–ISM interaction. We identify and characterize 100 pc–1 kpc scale substructure within this dust front caused by ram pressure, including head–tail filaments, C-shaped filaments, and long smooth dust fronts. The morphology of these features strongly suggests that dense gas clouds partially decouple from surrounding lower density gas during stripping, but decoupling is inhibited, possibly by magnetic fields that link and bind distant parts of the ISM.« less

NASA Hubble Sees Comet ISON Intact

NASA Image and Video Library

2013-10-09

This image from NASA Hubble Space Telescope of the sunward plunging comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the sun warms it. In this NASA Hubble Space Telescope image taken on October 9, 2013 the comet's solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments. Moreover, the coma or head surrounding the comet's nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. What's more, a polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off. This color composite image was assembled using two filters. The comet's coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars' orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on 26 December, at a distance of 39.9 million miles. http://photojournal.jpl.nasa.gov/catalog/PIA18153

HUBBLE SPACE TELESCOPE OBSERVATIONS OF THE NUCLEUS OF COMET C/2012 S1 (ISON)

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

Lamy, Philippe L.; Toth, Imre; Weaver, Harold A., E-mail: philippe.lamy@lam.fr

2014-10-10

We report on the analysis of several sequences of broadband visible images of comet C/2012 S1 (ISON) taken with the Wide Field Camera 3 of the Hubble Space Telescope on 2013 April 10, May 8, October 9, and November 1 in an attempt to detect and characterize its nucleus. Whereas the overwhelming coma precluded the detection of the nucleus in the first two sequences, the contrast was sufficient in early October to unambiguously retrieve the signal from the nucleus. Two images taken within a few minutes led to similar V magnitudes for the nucleus of 21.97 and 22.0 with amore » 1σ uncertainty of 0.065. Assuming a standard value for the geometric albedo (0.04) and a linear phase function with a coefficient of 0.04 mag deg{sup –1}, these V values imply that the nucleus radius is 0.68 ± 0.02 km. Although this result does depend on these two assumptions, we argue that the radius most likely lies in the range 0.6-0.9 km. This result is consistent with the constraints derived from the water production rates reported by Combi et al. The last sequence of images in 2013 November revealed temporal variation of the innermost coma. If attributed to a single rotating jet, this coma brightness variation suggests the rotational period of the nucleus may be close to ∼10.4 hr.« less

Wavefront aberrations and retinal image quality in different lenticular opacity types and densities.

PubMed

Wu, Cheng-Zhe; Jin, Hua; Shen, Zhen-Nv; Li, Ying-Jun; Cui, Xun

2017-11-10

To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and densities. Forty-one eyes with nuclear cataract, 33 eyes with cortical cataract, and 29 eyes with posterior subcapsular cataract were examined. In each group, wavefront aberrations in the entire eye and in the internal optics and retinal image quality were measured using a raytracing aberrometer. Eyes with cortical cataracts showed significantly higher coma-like aberrations compared to the other two groups in both entire eye and internal optic aberrations (P = 0.012 and P = 0.007, respectively). Eyes with nuclear cataract had lower spherical-like aberrations than the other two groups in both entire eye and internal optics aberrations (P < 0.001 and P < 0.001, respectively). In the nuclear cataract group, nuclear lens density was negatively correlated with internal spherical aberrations (r = -0.527, P = 0.005). Wavefront technology is useful for objective and quantitative analysis of retinal image quality deterioration in eyes with different early lenticular opacity types and densities. Understanding the wavefront optical properties of different crystalline lens opacities may help ophthalmic surgeons determine the optimal time to perform cataract surgery.

Real-time visualization of clustering and intracellular transport of gold nanoparticles by correlative imaging

NASA Astrophysics Data System (ADS)

Liu, Mengmeng; Li, Qian; Liang, Le; Li, Jiang; Wang, Kun; Li, Jiajun; Lv, Min; Chen, Nan; Song, Haiyun; Lee, Joon; Shi, Jiye; Wang, Lihua; Lal, Ratnesh; Fan, Chunhai

2017-05-01

Mechanistic understanding of the endocytosis and intracellular trafficking of nanoparticles is essential for designing smart theranostic carriers. Physico-chemical properties, including size, clustering and surface chemistry of nanoparticles regulate their cellular uptake and transport. Significantly, even single nanoparticles could cluster intracellularly, yet their clustering state and subsequent trafficking are not well understood. Here, we used DNA-decorated gold (fPlas-gold) nanoparticles as a dually emissive fluorescent and plasmonic probe to examine their clustering states and intracellular transport. Evidence from correlative fluorescence and plasmonic imaging shows that endocytosis of fPlas-gold follows multiple pathways. In the early stages of endocytosis, fPlas-gold nanoparticles appear mostly as single particles and they cluster during the vesicular transport and maturation. The speed of encapsulated fPlas-gold transport was critically dependent on the size of clusters but not on the types of organelle such as endosomes and lysosomes. Our results provide key strategies for engineering theranostic nanocarriers for efficient health management.

Unrepaired clustered DNA lesions induce chromosome breakage in human cells

PubMed Central

Asaithamby, Aroumougame; Hu, Burong; Chen, David J.

2011-01-01

Clustered DNA damage induced by ionizing radiation is refractory to repair and may trigger carcinogenic events for reasons that are not well understood. Here, we used an in situ method to directly monitor induction and repair of clustered DNA lesions in individual cells. We showed, consistent with biophysical modeling, that the kinetics of loss of clustered DNA lesions was substantially compromised in human fibroblasts. The unique spatial distribution of different types of DNA lesions within the clustered damages, but not the physical location of these damages within the subnuclear domains, determined the cellular ability to repair the damage. We then examined checkpoint arrest mechanisms and yield of gross chromosomal aberrations. Induction of nonrepairable clustered damage affected only G2 accumulation but not the early G2/M checkpoint. Further, cells that were released from the G2/M checkpoint with unrepaired clustered damage manifested a spectrum of chromosome aberrations in mitosis. Difficulties associated with clustered DNA damage repair and checkpoint release before the completion of clustered DNA damage repair appear to promote genome instability that may lead to carcinogenesis. PMID:21527720

Two Years and Five Images of Supernova Refsdal

NASA Astrophysics Data System (ADS)

Kelly, Patrick

2017-01-01

In 1964, Sjur Refsdal hypothesized that a supernova (SN) whose light takes multiple paths to reach us around a strong gravitational lens could be used as a highly powerful probe. For such a system, the time delays between the images of the SN should depend sensitively on the cosmic expansion rate and the distribution of matter within the lens. I will present observations of the first strongly lensed SN resolved into multiple images, which was found in near-infrared imaging taken in early November 2014 with the Hubble Space Telescope (HST). SN `Refsdal' appeared in an Einstein cross configuration around an early-type galaxy in the MACS J1149.6+2223 cluster (z=0.54), and its light curve and spectrum are broadly similar to those of the peculiar and well-studied SN 1987A. Models of the cluster potential predicted that the SN would reappear within two years in a different image of its spiral host galaxy (z=1.49) closer to the cluster's center. In early December 2015, we detected the new image of the SN with the HST, and we anticipate being able to measure its relative time delay with a 1-2% precision, providing a rare test of blind model predictions.

Conserved gene clusters in bacterial genomes provide further support for the primacy of RNA

NASA Technical Reports Server (NTRS)

Siefert, J. L.; Martin, K. A.; Abdi, F.; Widger, W. R.; Fox, G. E.

1997-01-01

Five complete bacterial genome sequences have been released to the scientific community. These include four (eu)Bacteria, Haemophilus influenzae, Mycoplasma genitalium, M. pneumoniae, and Synechocystis PCC 6803, as well as one Archaeon, Methanococcus jannaschii. Features of organization shared by these genomes are likely to have arisen very early in the history of the bacteria and thus can be expected to provide further insight into the nature of early ancestors. Results of a genome comparison of these five organisms confirm earlier observations that gene order is remarkably unpreserved. There are, nevertheless, at least 16 clusters of two or more genes whose order remains the same among the four (eu)Bacteria and these are presumed to reflect conserved elements of coordinated gene expression that require gene proximity. Eight of these gene orders are essentially conserved in the Archaea as well. Many of these clusters are known to be regulated by RNA-level mechanisms in Escherichia coli, which supports the earlier suggestion that this type of regulation of gene expression may have arisen very early. We conclude that although the last common ancestor may have had a DNA genome, it likely was preceded by progenotes with an RNA genome.

The colour-magnitude relation as a constraint on the formation of rich cluster galaxies

NASA Astrophysics Data System (ADS)

Bower, Richard G.; Kodama, Tadayuki; Terlevich, Ale

1998-10-01

The colours and magnitudes of early-type galaxies in galaxy clusters are strongly correlated. The existence of such a correlation has been used to infer that early-type galaxies must be old passively evolving systems. Given the dominance of early-type galaxies in the cores of rich clusters, this view sits uncomfortably with the increasing fraction of blue galaxies found in clusters at intermediate redshifts, and with the late formation of galaxies favoured by cold dark matter type cosmologies. In this paper, we make a detailed investigation of these issues and examine the role that the colour-magnitude relation can play in constraining the formation history of galaxies currently found in the cores of rich clusters. We start by considering the colour evolution of galaxies after star formation ceases. We show that the scatter of the colour-magnitude relation places a strong constraint on the spread in age that is allowed for the bulk of the stellar population. In the extreme case that the stars are formed in a single event, the spread in age cannot be more than 4 Gyr. Although the bulk of stars must be formed in a short period, continuing formation of stars in a fraction of the galaxies is not so strongly constrained. We examine a model in which star formation occurs over an extended period of time in most galaxies with star formation being truncated randomly. This model is consistent with the formation of stars in a few systems until look-back times of ~5Gyr. An extension of this type of star formation history allows us to reconcile the small present-day scatter of the colour-magnitude relation with the observed blue galaxy fractions of intermediate redshift galaxy clusters. In addition to setting a limit on the variations in luminosity-weighted age between the stellar populations of cluster galaxies, the colour-magnitude relation can also be used to constrain the degree of merging between pre-existing stellar systems. This test relies on the slope of the colour-magnitude relation: mergers between galaxies of unequal mass tend to reduce the slope of the relation and to increase its scatter. We show that random mergers between galaxies very rapidly remove any well-defined colour-magnitude correlation. This model is not physically motivated, however, and we prefer to examine the merger process using a self-consistent merger tree. In such a model there are two effects. First, massive galaxies preferentially merge with systems of similar mass. Secondly, the rate of mass growth is considerably smaller than for the random merger case. As a result of both of these effects, the colour-magnitude correlation persists through a larger number of merger steps. The passive evolution of galaxy colours and their averaging in dissipationless mergers provide opposing constraints on the formation of cluster galaxies in a hierarchical model. At the level of current constraints, a compromise solution appears possible. The bulk of the stellar population must have formed before z=1, but cannot have formed in mass units much less than about half the mass of a present-day L_* galaxy. In this case, the galaxies are on average old enough that stellar population evolution is weak, yet formed recently enough that mass growth resulting from mergers is small.

Diagnosis of myxedema coma complicated by renal failure: a case report.

PubMed

Takamura, Akiteru; Sangen, Ryusho; Furumura, Yoshiki; Usuda, Daisuke; Kasamaki, Yuji; Kanda, Tsugiyasu

2017-04-01

Myxedema coma, caused by severe lack of thyroid hormone, is characterized by deterioration of mental status, hypothermia, hypotension, hyponatremia, and hypoventilation. We describe an 84-year-old woman who presented with renal failure and new onset severe hypothyroidism leading to challenges in the recognition of myxedema coma.

X-ray studies of coeval star samples. II - The Pleiades cluster as observed with the Einstein Observatory

NASA Technical Reports Server (NTRS)

Micela, G.; Sciortino, S.; Vaiana, G. S.; Harnden, F. R., Jr.; Rosner, R.

1990-01-01

Coronal X-ray emission of the Pleiades stars is investigated, and maximum likelihood, integral X-ray luminosity functions are computed for Pleiades members in selected color-index ranges. A detailed search is conducted for long-term variability in the X-ray emission of those stars observed more than once. An overall comparison of the survey results with those of previous surveys confirms the ubiquity of X-ray emission in the Pleiades cluster stars and its higher rate of emission with respect to older stars. It is found that the X-ray emission from dA and early dF stars cannot be proven to be dissimilar to that of Hyades and field stars of the same spectral type. The Pleiades cluster members show a real rise of the X-ray luminosity from dA stars to early dF stars. X-ray emission for the young, solarlike Pleiades stars is about two orders of magnitude more intense than for the nearby solarlike stars.

Myxedema coma in a patient with Down's syndrome.

PubMed

Bansal, Darpan; Nanda, Ashish; Gupta, Ekta; Croker, Mary; Williams, Misty L; Bacchus, Amy; Simmons, Debra; Erbland, Marcia

2006-11-01

hyroid dysfunction is common in Down's syndrome, most common being hypothyroidism. Longstanding, untreated hypothyroidism can lead to myxedema coma. Here we report a patient with Down's syndrome who presented with myxedema coma. The three essential elements for the diagnosis of myxedema coma include altered mental status, defective thermoregulation and a precipitating event or illness; all of these were present in our patient. Also, very high TSH, low T3 and T4, and the rapid response to the treatment with levothyroxine confirmed the diagnosis. Patients with Down's syndrome should have regular screening for thyroid dysfunction.

Thyroid gland disorder emergencies: thyroid storm and myxedema coma.

PubMed

Hampton, Jessica

2013-01-01

Although thyroid dysfunction will develop in more than 12% of the US population during their lifetimes, true thyroid emergencies are rare. Thyroid storm and myxedema coma are endocrine emergencies resulting from thyroid hormone dysregulation, usually coupled with an acute illness as a precipitant. Careful assessment of risk and rapid action, once danger is identified, are essential for limiting morbidity and mortality related to thyroid storm and myxedema coma. This article reviews which patients are at risk, explains thyroid storm and myxedema coma, and describes pharmacological treatment and supportive cares.

An Atypical Case of Myxedema Coma with Concomitant Nonconvulsive Seizure

PubMed Central

Patel, Pratik; Varallo-Rodriguez, Cristina

2016-01-01

Hypothyroidism is a prevalent condition in the general population that is treatable with appropriately dosed thyroid hormone replacement medication. Infrequently, patients will present with myxedema coma, characterized by hypothermia, hypotension, bradycardia, and altered mental status in the setting of severe hypothyroidism. Myxedema coma has also been known to manifest in a number of unusual and dangerous forms. Here, we present the case of a woman we diagnosed with an uncharacteristic expression of myxedema coma and nonconvulsive seizure complicated by a right middle cerebral artery infarct. PMID:27872766

Reestablishment of ion homeostasis during chill-coma recovery in the cricket Gryllus pennsylvanicus

PubMed Central

MacMillan, Heath A.; Williams, Caroline M.; Staples, James F.; Sinclair, Brent J.

2012-01-01

The time required to recover from cold-induced paralysis (chill-coma) is a common measure of insect cold tolerance used to test central questions in thermal biology and predict the effects of climate change on insect populations. The onset of chill-coma in the fall field cricket (Gryllus pennsylvanicus, Orthoptera: Gryllidae) is accompanied by a progressive drift of Na+ and water from the hemolymph to the gut, but the physiological mechanisms underlying recovery from chill-coma are not understood for any insect. Using a combination of gravimetric methods and atomic absorption spectroscopy, we demonstrate that recovery from chill-coma involves a reestablishment of hemolymph ion content and volume driven by removal of Na+ and water from the gut. Recovery is associated with a transient elevation of metabolic rate, the time span of which increases with increasing cold exposure duration and closely matches the duration of complete osmotic recovery. Thus, complete recovery from chill-coma is metabolically costly and encompasses a longer period than is required for the recovery of muscle potentials and movement. These findings provide evidence that physiological mechanisms of hemolymph ion content and volume regulation, such as ion-motive ATPase activity, are instrumental in chill-coma recovery and may underlie natural variation in insect cold tolerance. PMID:23184963

Non-Random Spatial Distribution of Impacts in the Stardust Cometary Collector

NASA Technical Reports Server (NTRS)

Westphal, Andrew J.; Bastien, Ronald K.; Borg, Janet; Bridges, John; Brownlee, Donald E.; Burchell, Mark J.; Cheng, Andrew F.; Clark, Benton C.; Djouadi, Zahia; Floss, Christine

2007-01-01

In January 2004, the Stardust spacecraft flew through the coma of comet P81/Wild2 at a relative speed of 6.1 km/sec. Cometary dust was collected at in a 0.1 sq m collector consisting of aerogel tiles and aluminum foils. Two years later, the samples successfully returned to earth and were recovered. We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than approx.10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a noncometary impact on the spacecraft bus just forward of the collector. Here we summarize the observations, and review the evidence for and against three scenarios that we have considered for explaining the impact clustering found on the Stardust aerogel and foil collectors.

Massive Galaxies Are Larger in Dense Environments: Environmental Dependence of Mass-Size Relation of Early-type Galaxies

NASA Astrophysics Data System (ADS)

Yoon, Yongmin; Im, Myungshin; Kim, Jae-Woo

2017-01-01

Under the Λ cold dark matter (ΛCDM) cosmological models, massive galaxies are expected to be larger in denser environments through frequent hierarchical mergers with other galaxies. Yet, observational studies of low-redshift early-type galaxies have shown no such trend, standing as a puzzle to solve during the past decade. We analyzed 73,116 early-type galaxies at 0.1 ≤ z < 0.15, adopting a robust nonparametric size measurement technique and extending the analysis to many massive galaxies. We find for the first time that local early-type galaxies heavier than 1011.2 M⊙ show a clear environmental dependence in mass-size relation, in such a way that galaxies are as much as 20%-40% larger in the densest environments than in underdense environments. Splitting the sample into the brightest cluster galaxies (BCGs) and non-BCGs does not affect the result. This result agrees with the ΛCDM cosmological simulations and suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory.

CLASH: Extending galaxy strong lensing to small physical scales with distant sources highly magnified by galaxy cluster members

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

Grillo, C.; Christensen, L.; Gobat, R.

2014-05-01

We present a complex strong lensing system in which a double source is imaged five times by two early-type galaxies. We take advantage in this target of the extraordinary multi-band photometric data set obtained as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) program, complemented by the spectroscopic measurements of the VLT/VIMOS and FORS2 follow-up campaign. We use a photometric redshift value of 3.7 for the source and confirm spectroscopically the membership of the two lenses to the galaxy cluster MACS J1206.2–0847 at redshift 0.44. We exploit the excellent angular resolution of the HST/ACS images to modelmore » the two lenses in terms of singular isothermal sphere profiles and derive robust effective velocity dispersion values of 97 ± 3 and 240 ± 6 km s{sup –1}. Interestingly, the total mass distribution of the cluster is also well characterized by using only the local information contained in this lensing system, which is located at a projected distance of more than 300 kpc from the cluster luminosity center. According to our best-fitting lensing and composite stellar population models, the source is magnified by a total factor of 50 and has a luminous mass of approximately (1.0 ± 0.5) × 10{sup 9} M {sub ☉} (assuming a Salpeter stellar initial mass function). By combining the total and luminous mass estimates of the two lenses, we measure luminous over total mass fractions projected within the effective radii of 0.51 ± 0.21 and 0.80 ± 0.32. Remarkably, with these lenses we can extend the analysis of the mass properties of lens early-type galaxies by factors that are approximately two and three times smaller than previously done with regard to, respectively, velocity dispersion and luminous mass. The comparison of the total and luminous quantities of our lenses with those of astrophysical objects with different physical scales, like massive early-type galaxies and dwarf spheroidals, reveals the potential of studies of this kind for improving our knowledge about the internal structure of galaxies. These studies, made possible thanks to the CLASH survey, will allow us to go beyond the current limits posed by the available lens samples in the field.« less

Curious Case of a Stripped Elliptical Galaxy

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-05-01

MUSE fields of view (1 1 for each square) are superimposed on a pseudo-color image of the elliptical galaxy in Abell 2670. The blue blobs lie in the opposite direction to the galactic center. [Sheen et al. 2017]An elliptical galaxy in the cluster Abell 2670 has been discovered with some unexpected features. What conditions led to this galaxys unusual morphology?Unexpected JellyfishWe often see galaxies that have been disrupted or reshaped due to their motion within a cluster but these are usually late-type galaxies like our own. Such gas-rich galaxies are distorted by ram pressure as they fall into the cluster center, growing long tails of stripped gas and young stars that earn them the name jellyfish galaxies.But early-type, elliptical galaxies have long since used up or cleared out most of their gas, and they correspondingly form very few new stars. Its therefore unsurprising that theyve never before been spotted to have jellyfish-like features.Panels a and b show zoomed-in observations of some of the star-forming blobs with tadpole-like morphology. Panel c shows a schematic illustration of how ram-pressure stripping causes this shape. [Adapted from Sheen et al. 2017]New deep observations of an elliptical galaxy in the cluster Abell 2670, however, have revealed some unexpected structures for an early-type galaxy. Led by Yun-Kyeong Sheen (Korea Astronomy and Space Science Institute), a team of scientists now reports on the optical and spectroscopic observations of this galaxy, made with the MUSE instrument on the Very Large Telescope in Chile.Tadpole BlobsThese observations reveal a number of features, including starbursts at the galactic center, 80-parsec-long tails of ionized gas, disturbed halo features, and several blue star-forming blobs with tadpole-like morphology in the surrounding region. The blobs have stellar tails that point in the direction of motion of the galaxy (toward the cluster center) and streams of ionized gas that point in the opposite direction.All of these features are signs that this galaxy is being ram-pressurestripped as it falls into the center of the cluster. The star-forming blobs, for example, are exhibiting classic ram-pressure-stripping behavior: as a galaxy falls into the cluster center, streams of ionized gas blow downwind, and stars (which dont respond as easily to the force of the wind) are left behind in a stream pointing upwind.Gas from a Merger?An example of a tidal tail drawn out from a disrupted late-type galaxy. The disrupted galaxy in Abell 2670 is, in contrast, an early-type, elliptical galaxy that should be gas-poor. [H. Ford, JHU/M. Clampin, STScI/G. Hartig, STScI/G. Illingworth, UCO, Lick/ACS Science Team/ESA/NASA]But if this is an elliptical galaxy, where did the gas come from for the tails and the galactic-center star formation? To rule out the obvious, the authors first check that this galaxy really is an early-type elliptical. The galaxys color (reddened), morphology (elliptical and no sign of a stellar disk), and stellar velocities (no sign of stellar rotation) all confirm this.The authors therefore speculate that the galaxy recently underwent a wet merger a merger with a companion galaxy that was gas-rich. Much of this gas was driven to the center of the elliptical galaxy in the merger, and its now responsible for the starbursts there.Well hopefully be able to draw stronger conclusions about this unusual galaxy after additional investigation into the amount of gas it contains and the galaxys star formation rate. In the meantime, this stripped elliptical makes for an intriguing puzzle!CitationYun-Kyeong Sheen et al 2017 ApJL 840 L7. doi:10.3847/2041-8213/aa6d79

Myxedema coma: a new look into an old crisis.

PubMed

Mathew, Vivek; Misgar, Raiz Ahmad; Ghosh, Sujoy; Mukhopadhyay, Pradip; Roychowdhury, Pradip; Pandit, Kaushik; Mukhopadhyay, Satinath; Chowdhury, Subhankar

2011-01-01

Myxedema crisis is a severe life threatening form of decompensated hypothyroidism which is associated with a high mortality rate. Infections and discontinuation of thyroid supplements are the major precipitating factors while hypothermia may not play a major role in tropical countries. Low intracellular T3 leads to cardiogenic shock, respiratory depression, hypothermia and coma. Patients are identified on the basis of a low index of suspicion with a careful history and examination focused on features of hypothyroidism and precipitating factors. Arrythmias and coagulation disorders are increasingly being identified in myxedema crisis. Thyroid replacement should be initiated as early as possible with careful attention to hypotension, fluid replacement and steroid replacement in an intensive care facility. Studies have shown that replacement of thyroid hormone through ryles tube with a loading dose and maintenance therapy is as efficacious as intravenous therapy. In many countries T3 is not available and oral therapy with T4 can be used effectively without major significant difference in outcomes. Hypotension, bradycardia at presentation, need for mechanical ventilation, hypothermia unresponsive to treatment, sepsis, intake of sedative drugs, lower GCS and high APACHE II scores and Sequential Organ Failure Assessment (SOFA) scores more than 6 are significant predictors of mortality in myxedema crisis. Early intervention in hypothyroid patients developing sepsis and other precipitating factors and ensuring continued intake of thyroid supplements may prevent mortality and morbidity associated with myxedema crisis.

Myxedema Coma: A New Look into an Old Crisis

PubMed Central

Mathew, Vivek; Misgar, Raiz Ahmad; Ghosh, Sujoy; Mukhopadhyay, Pradip; Roychowdhury, Pradip; Pandit, Kaushik; Mukhopadhyay, Satinath; Chowdhury, Subhankar

2011-01-01

Myxedema crisis is a severe life threatening form of decompensated hypothyroidism which is associated with a high mortality rate. Infections and discontinuation of thyroid supplements are the major precipitating factors while hypothermia may not play a major role in tropical countries. Low intracellular T3 leads to cardiogenic shock, respiratory depression, hypothermia and coma. Patients are identified on the basis of a low index of suspicion with a careful history and examination focused on features of hypothyroidism and precipitating factors. Arrythmias and coagulation disorders are increasingly being identified in myxedema crisis. Thyroid replacement should be initiated as early as possible with careful attention to hypotension, fluid replacement and steroid replacement in an intensive care facility. Studies have shown that replacement of thyroid hormone through ryles tube with a loading dose and maintenance therapy is as efficacious as intravenous therapy. In many countries T3 is not available and oral therapy with T4 can be used effectively without major significant difference in outcomes. Hypotension, bradycardia at presentation, need for mechanical ventilation, hypothermia unresponsive to treatment, sepsis, intake of sedative drugs, lower GCS and high APACHE II scores and Sequential Organ Failure Assessment (SOFA) scores more than 6 are significant predictors of mortality in myxedema crisis. Early intervention in hypothyroid patients developing sepsis and other precipitating factors and ensuring continued intake of thyroid supplements may prevent mortality and morbidity associated with myxedema crisis. PMID:21941682

A classification of substance-dependent men on temperament and severity variables.

PubMed

Henderson, Melinda J; Galen, Luke W

2003-06-01

This study examined the validity of classifying substance abusers based on temperament and dependence severity, and expanded the scope of typology differences to proximal determinants of use (e.g., expectancies, motives). Patients were interviewed about substance use, depression, and family history of alcohol and drug abuse. Self-report instruments measuring temperament, expectancies, and motives were completed. Participants were 147 male veterans admitted to inpatient substance abuse treatment at a U.S. Department of Veterans Affairs medical center. Cluster analysis identified four types of users with two high substance problem severity and two low substance problem severity groups. Two, high problem severity, early onset groups differed only on the cluster variable of negative affectivity (NA), but showed differences on antisocial personality characteristics, hypochondriasis, and coping motives for alcohol. The two low problem severity groups were distinguished by age of onset and positive affectivity (PA). The late onset, low PA group had a higher incidence of depression, a greater tendency to use substances in solitary contexts, and lower enhancement motives for alcohol compared to the early onset, high PA cluster. The four-cluster solution yielded more distinctions on external criteria than the two-cluster solution. Such temperament variation within both high and low severity substance abusers may be important for treatment planning.

A rare genetic disorder causing persistent severe neonatal hypoglycaemia the diagnostic workup.

PubMed

Francescato, Gaia; Salvatoni, Alessandro; Persani, Luca; Agosti, Massimo

2012-07-19

We report a case of familial glucocorticoid deficiency (FGD), a rare genetic autosomal-recessive disorder with typical hyperpigmentation of the skin and mucous membranes, severe hypoglycaemia, occasionally leading to seizures and coma, feeding difficulties, failure to thrive and infections. A newborn child was admitted, on his second day of life, to our neonatal intensive care unit because of seizures and respiratory insufficiency. Hyperpigmentation was not evident due to his Senegalese origin. The clinical presentation led us to consider a wide range of diagnostic hypothesis. Laboratory findings brought us to the diagnosis of FGD that was confirmed by molecular analysis showing an MC2R:p.Y254C mutation previously reported as causative of type 1 FGD and two novel heterozygous non-synonymous single-nucleotide polymorphisms in exon 2 and 3 of melanocortin 2 receptor accessory protein-α, whose role in the disease is currently unknown. The importance of an early collection and storage of blood samples during hypoglycaemic event is emphasised.

Burst Suppression on Processed Electroencephalography as a Predictor of Post-Coma Delirium in Mechanically Ventilated ICU Patients

PubMed Central

Andresen, Jennifer M.; Girard, Timothy D.; Pandharipande, Pratik P.; Davidson, Mario A.; Ely, E. Wesley; Watson, Paula L.

2015-01-01

Objectives Many patients, due to a combination of illness and sedatives, spend a considerable amount of time in a comatose state that can include time in burst suppression. We sought to determine if burst suppression measured by processed electroencephalography (pEEG) during coma in sedative-exposed patients is a predictor of post-coma delirium during critical illness. Design Observational convenience sample cohort Setting Medical and surgical ICUs in a tertiary care medical center Patients Cohort of 124 mechanically ventilated ICU patients Measurements and Main Results Depth of sedation was monitored twice daily using the Richmond Agitation-Sedation Scale and continuously monitored by pEEG. When non-comatose, patients were assessed for delirium twice daily using Confusion Assessment Method for the ICU (CAM-ICU). Multiple logistic regression and Cox proportional hazards regression were used to assess associations between time in burst suppression and both incidence and time to resolution of delirium, respectively, adjusting for time in deep sedation and a principal component score consisting of APACHE II score and cumulative doses of sedatives while comatose. Of the 124 patients enrolled and monitored, 55 patients either never had coma or never emerged from coma yielding 69 patients for whom we performed these analyses; 42 of these 69 (61%) had post-coma delirium. Most patients had burst-suppression during coma, though often short-lived [ median (intraquartile range) time in burst suppression, 6.4 (1-58) minutes]. After adjusting for covariates, even this short time in burst suppression independently predicted a higher incidence of post-coma delirium [odds ratio 4.16; 95% confidence interval (CI) 1.27-13.62; p=0.02] and a lower likelihood (delayed) resolution of delirium (hazard ratio 0.78; 95% CI 0.53-0.98; p=0.04). Conclusions Time in burst suppression during coma, as measured by processed EEG, was an independent predictor of incidence and time to resolution of post-coma/post-deep sedation delirium. These findings of this single center investigation support lighter sedation strategies. PMID:25072756

Antagonists in Mutual Antipathies: A Person-Oriented Approach

ERIC Educational Resources Information Center

Guroglu, Berna; Haselager, Gerbert J. T.; van Lieshout, Cornelis F. M.; Scholte, Ron H. J.

2009-01-01

This study investigated the heterogeneity of mutual antipathy relationships. Separate cluster analyses of peer interactions of early adolescents (mean age 11 years) and adolescents (mean age of 14) yielded 3 "types of individuals" in each age group, namely Prosocial, Antisocial, and Withdrawn. Prevalence analysis of the 6 possible combinations of…

VEGAS-SSS: A VST Early-Type GAlaxy Survey: Analysis of Small Stellar System

NASA Astrophysics Data System (ADS)

Cantiello, M.

VEGAS-SSS is a program devoted to study the properties of small stellar systems (SSSs) around bright galaxies, built on the VEGAS survey. At completion, the survey will have collected detailed photometric information of ˜ 100 bright early-type galaxies to study the properties of diffuse light (surface brightness, colours, SBF, etc.) and the clustered light (compact stellar systems) out to previously unreached projected galactocentric radii. VEGAS-SSS will define an accurate and homogeneous dataset that will have an important legacy value for studies of the evolution and transformation processes taking place in galaxies through the fossil information provided by SSSs.

Development of an objective tool for the diagnosis of myxedema coma.

PubMed

Chiong, Yien V; Bammerlin, Elaine; Mariash, Cary N

2015-09-01

Myxedema coma, a rare entity, with a reported 25%-65% mortality had no objective criteria for making the diagnosis when we began our study. We developed an objective screening tool for myxedema coma to more easily identify patients and examine the best treatment method in future prospective studies to reduce the mortality of this entity. We conducted a retrospective chart review to find all patients aged ≥18 years admitted with myxedema coma from January 1, 2005 through June 13, 2010 at Indiana University Health Methodist Hospital. On the basis of both our retrospective chart review and on literature accounts, we identified 6 criteria to diagnose myxedema coma. We identified 10 patients initially diagnosed with myxedema coma and established a control group consisting of 13 patients identified with altered mental status and increased thyroid-stimulating hormone (TSH) levels. The 6 variables we created for the screening tool were heart rate, temperature, Glasgow coma scale, TSH, free thyroxine, and precipitating factors. The screening tool has a sensitivity and specificity of about 80%. We ran a logistic regression model using the 10 study patients and 13 controls with the 6 variables. No variables alone significantly contributed to the model. However, the overall model was highly significant (P = 0.012), providing strong support for a scoring system that uses these variables simultaneously. This screening tool enables physicians to rapidly diagnose myxedema coma to expedite treatment. A more refined diagnostic tool may be used in future clinical studies designed to determine the optimal treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparative study on assessment procedures and metric properties of two scoring systems of the Coma Recovery Scale-Revised items: standard and modified scores.

PubMed

Sattin, Davide; Lovaglio, Piergiorgio; Brenna, Greta; Covelli, Venusia; Rossi Sebastiano, Davide; Duran, Dunja; Minati, Ludovico; Giovannetti, Ambra Mara; Rosazza, Cristina; Bersano, Anna; Nigri, Anna; Ferraro, Stefania; Leonardi, Matilde

2017-09-01

The study compared the metric characteristics (discriminant capacity and factorial structure) of two different methods for scoring the items of the Coma Recovery Scale-Revised and it analysed scale scores collected using the standard assessment procedure and a new proposed method. Cross sectional design/methodological study. Inpatient, neurological unit. A total of 153 patients with disorders of consciousness were consecutively enrolled between 2011 and 2013. All patients were assessed with the Coma Recovery Scale-Revised using standard (rater 1) and inverted (rater 2) procedures. Coma Recovery Scale-Revised score, number of cognitive and reflex behaviours and diagnosis. Regarding patient assessment, rater 1 using standard and rater 2 using inverted procedures obtained the same best scores for each subscale of the Coma Recovery Scale-Revised for all patients, so no clinical (and statistical) difference was found between the two procedures. In 11 patients (7.7%), rater 2 noted that some Coma Recovery Scale-Revised codified behavioural responses were not found during assessment, although higher response categories were present. A total of 51 (36%) patients presented the same Coma Recovery Scale-Revised scores of 7 or 8 using a standard score, whereas no overlap was found using the modified score. Unidimensionality was confirmed for both score systems. The Coma Recovery Scale Modified Score showed a higher discriminant capacity than the standard score and a monofactorial structure was also supported. The inverted assessment procedure could be a useful evaluation method for the assessment of patients with disorder of consciousness diagnosis.

Gas Dynamics in the Fornax Cluster: Viscosity, turbulence, and sloshing

NASA Astrophysics Data System (ADS)

Kraft, Ralph; Su, Yuanyuan; Sheardown, Alexander; Roediger, Elke; Nulsen, Paul; Forman, William; Jones, Christine; Churazov, Eugene

2018-01-01

We present results from deep Chandra and XMM-Newton observations of the ICM in the Fornax cluster, and combine these data with specifically-tailored hydrodynamic simulations for an unprecedented view of the gas dynamics in this nearby cluster. We report the detection of four sloshing fronts (Su+2017). Based on our simulations, all four of these fronts can plausibly be attributed to the infall of the early-type galaxy NGC 1404 into the cluster potential. We argue that the presence of these sloshing cold fronts, the lack of its own extended gas halo, and the approximately transonic infall velocity indicate that this must be at least the second core passage for NGC 1404. Additionally, there is virtually no stripped tail of cool gas behind NGC 1404, conclusively demonstrating that the stripped gas is efficiently mixed with the cluster ICM. This mixing most likely occurs via small-scale Kelvin-Helmholtz instabilities formed in the high Reynolds number flow.

Astrophysics. Multiple images of a highly magnified supernova formed by an early-type cluster galaxy lens.

PubMed

Kelly, Patrick L; Rodney, Steven A; Treu, Tommaso; Foley, Ryan J; Brammer, Gabriel; Schmidt, Kasper B; Zitrin, Adi; Sonnenfeld, Alessandro; Strolger, Louis-Gregory; Graur, Or; Filippenko, Alexei V; Jha, Saurabh W; Riess, Adam G; Bradac, Marusa; Weiner, Benjamin J; Scolnic, Daniel; Malkan, Matthew A; von der Linden, Anja; Trenti, Michele; Hjorth, Jens; Gavazzi, Raphael; Fontana, Adriano; Merten, Julian C; McCully, Curtis; Jones, Tucker; Postman, Marc; Dressler, Alan; Patel, Brandon; Cenko, S Bradley; Graham, Melissa L; Tucker, Bradley E

2015-03-06

In 1964, Refsdal hypothesized that a supernova whose light traversed multiple paths around a strong gravitational lens could be used to measure the rate of cosmic expansion. We report the discovery of such a system. In Hubble Space Telescope imaging, we have found four images of a single supernova forming an Einstein cross configuration around a redshift z = 0.54 elliptical galaxy in the MACS J1149.6+2223 cluster. The cluster's gravitational potential also creates multiple images of the z = 1.49 spiral supernova host galaxy, and a future appearance of the supernova elsewhere in the cluster field is expected. The magnifications and staggered arrivals of the supernova images probe the cosmic expansion rate, as well as the distribution of matter in the galaxy and cluster lenses. Copyright © 2015, American Association for the Advancement of Science.

Non-Thermal Hard X-Ray Emission in Galaxy Clusters Observed with the BeppoSAX PDS

NASA Technical Reports Server (NTRS)

Nevalainen, Jukka H.; Oosterbroeck, T.; Bonamente, Max; Six, N. Frank (Technical Monitor)

2002-01-01

We studied the X-ray emission in a sample of clusters using the BeppoSAX PDS instrument in the 20 -- 80 keV energy band. We estimated the non-thermal cluster emission (HXR) by modeling the thermal contribution from the cluster gas and the non-thermal contamination from the AGN in the field, and propagating the corresponding uncertainties. We also evaluated and propagated the systematic uncertainties due to the background fluctuations. The resulting non-thermal component is detected at a sigma level in approx. 50 % of the non-significantly AGN-contaminated clusters, i.e. in clusters A2142, A2256, A3376, Coma, Ophiuchus and Virgo. Furthermore, Virgo is detected at a 4 sigma level. All the clusters detected at a 2 sigma level exhibit some degree of merger signatures, i.e. deviations from the azimuthally symmetric brightness and temperature distributions, while the relaxed clusters are detected at a lower confidence. The data are consistent with a scenario whereby relaxed clusters have no non-thermal hard X-ray component, whereas merger clusters do, with a 20 -- 80 keV luminosity of approx. 10(exp 42-44)((h(sub 50))(exp -2))(erg/s). Consistent with merger boosting of cluster temperatures, the non-thermal luminosity increases by 2-3 orders of magnitude between the average cluster temperatures 2 and 10 keV, as L(sub NTE) is proportional to T(sup j) with j = 2.4+/-0.3. These results corroborate the assumption which is the essential element in most non-thermal hard X-ray emission models. The co-added spectrum of all non-significantly AGN-contaminated clusters indicates a power-law spectrum for the non-thermal component with a photon index of 1.5+/-0.25 at 1 sigma confidence level. Unless there is a high energy cut-off in the electron velocity distribution, the total spectrum implies that Inverse Compton scatter of Cosmic Microwave Background photons from electron population dominates over the non-thermal bremsstrahlung in producing hard X-rays in clusters on the merger shock acceleration of electrons in clusters.

Galactic Dark Matter Halos and Globular Cluster Populations. III. Extension to Extreme Environments

NASA Astrophysics Data System (ADS)

Harris, William E.; Blakeslee, John P.; Harris, Gretchen L. H.

2017-02-01

The total mass {M}{GCS} in the globular cluster (GC) system of a galaxy is empirically a near-constant fraction of the total mass {M}h\\equiv {M}{bary}+{M}{dark} of the galaxy across a range of 105 in galaxy mass. This trend is radically unlike the strongly nonlinear behavior of total stellar mass M ⋆ versus M h . We discuss extensions of this trend to two more extreme situations: (a) entire clusters of galaxies and (b) the ultra-diffuse galaxies (UDGs) recently discovered in Coma and elsewhere. Our calibration of the ratio {η }M={M}{GCS}/{M}h from normal galaxies, accounting for new revisions in the adopted mass-to-light ratio for GCs, now gives {η }M=2.9× {10}-5 as the mean absolute mass fraction. We find that the same ratio appears valid for galaxy clusters and UDGs. Estimates of {η }M in the four clusters we examine tend to be slightly higher than for individual galaxies, but more data and better constraints on the mean GC mass in such systems are needed to determine if this difference is significant. We use the constancy of {η }M to estimate total masses for several individual cases; for example, the total mass of the Milky Way is calculated to be {M}h=1.1× {10}12 {M}⊙ . Physical explanations for the uniformity of {η }M are still descriptive, but point to a picture in which massive dense star clusters in their formation stages were relatively immune to the feedback that more strongly influenced lower-density regions where most stars form.

Systematics of the CHON and other light-element particle populations in Comet Halley

NASA Technical Reports Server (NTRS)

Clark, Benton; Mason, Larry W.; Kissel, Jochen

1986-01-01

Based on chemical signatures measured by the PIA experiment during the Giotto flyby of comet Halley, particle classifications were designated. In addition to silicate-like grains and particles of mixed (cosmic) composition, there appear to be several light-element rich populations, including the CHON, (H,C), (H,C,O), and (H,C,N) particle types. These compositional classes are further distinguished by differences in mass distributions, a density indicator, and variations in relative abundance within the coma. These particle populations are evidence for chemical heterogeneity in the surface of the cometary nucleus. Particles found mainly in the inner coma may be volatile icy grains. Most of the N of the comet may be found in up to three different populations of grains; one or more of these may be responsible for the observation of cyanojets.

Music therapy for coma patients: preliminary results.

PubMed

Sun, J; Chen, W

2015-04-01

The application of quantitative EEG (δ+θ/α+β value) and GCS value to evaluate the role of music therapy for traumatic brain injury coma patients. Forty patients of traumatic brain injury coma were selected to meet the inclusion criteria. Twenty cases were selected for the rehabilitation, neurology and neurosurgery ward, whose families could actively cooperate with, and the patients could receive a long-term fixed nursing staff with formal music therapy (music group). Twenty cases were in the intensive care unit of the rehabilitation, neurology and neurosurgery ward. Their families members cooperated poorly, had often changing nursing staff, and without a formal music therapy (control group). After a one monthe follow up, the GCS value and quantitative EEG (δ+θ/α+β value) were compared between the two groups. Between the two groups, except for the presence or absence of formal music therapy, the rest of treatment had no significant difference and was matched by age, gender, and injury types. In 40 cases of traumatic brain injury patients, the GCS value increased in the music group after treatment when compared to the control group. The difference between the two groups was significant (p < 0.05). The quantitative EEG value (δ+θ/α+β value) of music group values were decreased after treatment, and the difference was significant compared with the control group (p < 0.05). Through the quantitative EEG (δ+θ/α+β value) and the GCS observation score, music therapy in patients with craniocerebral trauma coma has obviously an effect on promoting to regain consciousness. The quantitative EEG (δ+θ/α+β value) can be used as an objective index to evaluate the state of brain function.

Memory disorder related to coma duration after head injury.

PubMed Central

Vilkki, J; Poropudas, K; Servo, A

1988-01-01

The relationship of memory and intelligence test performances to coma duration was studied in 51 head injured patients who had not been operated on for intracranial haematoma. Memory defect was related to coma duration, and was not secondary to impaired perceptual or conceptual analysis of the material to be remembered. PMID:3236022

[Coma in France today].

PubMed

Do, Chung Hi

2015-01-01

Comas result from acute life-threatening neurological failure. To understand coma, it is firstly necessary to define it, to cite the aetiologies and their epidemiology and to describe the chronic disorders of consciousness. It is also important to address the challenges and principles of treatment during the acute phase. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Comparative composition, diversity, and abundance of oligosaccharides in early lactation milk from commercial dairy and beef cows

PubMed Central

Sischo, William M.; Short, Diana M.; Geissler, Mareen; Bunyatratchata, Apichaya; Barile, Daniela

2017-01-01

Prebiotics are nondigestible dietary ingredients, usually oligosaccharides (OS), that provide a health benefit to the host by directly modulating the gut microbiota. Although there is some information describing OS content in dairy-source milk, no information is available to describe the OS content of beef-source milk. Given the different trait emphasis between dairy and beef for milk production and calf survivability, it is plausible that OS composition, diversity, and abundance differ between production types. The goal of this study was to compare OS in milk from commercial dairy and beef cows in early lactation. Early-lactation multiparous cows (5–12 d in milk) from 5 commercial Holstein dairy herds and 5 Angus or Angus hybrid beef herds were sampled once. Milk was obtained from each enrolled cow and frozen on the farm. Subsequently, each milk sample was assessed for total solids, pH, and OS content and relative abundance. Oligosaccharide diversity and abundance within and between samples was transformed through principal component analysis to reduce data complexity. Factors from principal component analysis were used to create similarity clusters, which were subsequently used in a multivariate logistic regression. In total, 30 OS were identified in early-lactation cow milk, including 21 distinct OS and 9 isomers with unique retention times. The majority of OS detected in the milk samples were present in all individual samples regardless of production type. Two clusters described distribution patterns of OS for the study sample; when median OS abundance was compared between the 2 clusters, we found that overall OS relative abundance was consistently greater in the cluster dominated by beef cows. For several of the structures, including those with known prebiotic effect, the difference in abundance was 2- to 4-fold greater in the beef-dominated cluster. Assuming that beef OS content in milk is the gold standard for cattle, it is likely that preweaning dairy calves are deprived of dietary-source OS. Although supplementing rations with OS is an approach to rectify this deficiency, understanding the health and productivity effects of improving OS abundance being fed to preweaning calves is a necessary next step before recommending supplementation. These studies should account for the observation that OS products are variable for both OS diversity and structural complexity, and some products may not be suitable as prebiotics. PMID:28318588

Myxedema coma: diagnosis and treatment.

PubMed

Wall, C R

2000-12-01

Myxedema coma, the extreme manifestation of hypothyroidism, is an uncommon but potentially lethal condition. Patients with hypothyroidism may exhibit a number of physiologic alterations to compensate for the lack of thyroid hormone. If these homeostatic mechanisms are overwhelmed by factors such as infection, the patient may decompensate into myxedema coma. Patients with hypothyroidism typically have a history of fatigue, weight gain, constipation and cold intolerance. Physicians should include hypothyroidism in the differential diagnosis of every patient with hyponatremia. Patients with suspected myxedema coma should be admitted to an intensive care unit for vigorous pulmonary and cardiovascular support. Most authorities recommend treatment with intravenous levothyroxine (T4) as opposed to intravenous liothyronine (T3). Hydrocortisone should be administered until coexisting adrenal insufficiency is ruled out. Family physicians are in an important position to prevent myxedema coma by maintaining a high level of suspicion for hypothyroidism.

Models for Cometary Comae Containing Negative Ions

NASA Technical Reports Server (NTRS)

Cordiner, M. A.; Charnley, S. B.

2012-01-01

The presence of negative ions (anions) in cometary comae is known from Giotto mass spectrometry of IP/Halley. The anions O(-), OH(-), C(-), CH(-) and CN(-) have been detected, as well as unidentified anions with masses 22-65 and 85-110 amu [I]. Organic molecular anions such as C4H(-) and C6H(-) are known to have a significant impact on the charge balance of interstellar clouds and circumstellar envelopes and have been shown to act as catalysts for the gas phase synthesis of larger hydrocarbon molecules in the ISM, but their importance in cometary comae has not yet been fully explored. We present details of our new models for the chemistry of cometary comae that include atomic and molecular anions. We calculate the impact of these anions on the charge balance and examine their importance for cometary coma chemistry.

Revealing the Formation Mechanism of Ultra-Diffuse Galaxies

NASA Astrophysics Data System (ADS)

Garmire, Gordon

2017-09-01

Recently a population of large, very low optical surface brightness galaxies, so called ultra-diffuse galaxies (UDGs), were discovered in the outskirts of Coma clusters. Stellar line-of-sight velocity dispersions suggest large dark matter halo masses of 10^12 M_sun with very low baryon fractions ( 1%). The outstanding question waiting to be answered is: How do UDGs form and evolve? One theory is that UDGs are related to bright galaxies, however they are prevented from building a normal stellar population through various violent processes, such as gas stripping. We propose to observe Dragonfly 44, the most massive UDG known, for 100 ks with ACIS-I to test some of the formation theories.

Pre-processing and post-processing in group-cluster mergers

NASA Astrophysics Data System (ADS)

Vijayaraghavan, R.; Ricker, P. M.

2013-11-01

Galaxies in clusters are more likely to be of early type and to have lower star formation rates than galaxies in the field. Recent observations and simulations suggest that cluster galaxies may be `pre-processed' by group or filament environments and that galaxies that fall into a cluster as part of a larger group can stay coherent within the cluster for up to one orbital period (`post-processing'). We investigate these ideas by means of a cosmological N-body simulation and idealized N-body plus hydrodynamics simulations of a group-cluster merger. We find that group environments can contribute significantly to galaxy pre-processing by means of enhanced galaxy-galaxy merger rates, removal of galaxies' hot halo gas by ram pressure stripping and tidal truncation of their galaxies. Tidal distortion of the group during infall does not contribute to pre-processing. Post-processing is also shown to be effective: galaxy-galaxy collisions are enhanced during a group's pericentric passage within a cluster, the merger shock enhances the ram pressure on group and cluster galaxies and an increase in local density during the merger leads to greater galactic tidal truncation.

A Study of the Effects of Faint Dust Comae on the Spectra of Asteroids

NASA Astrophysics Data System (ADS)

Rondón, E.; Carvano, J.; Lorenz-Martins, S.

2017-09-01

The presence of dust comae on asteroids and centaurs is a phenomenon that became accepted in the last decades and which challenges the traditional definitions of asteroids and comets. A possible way of improving the chances of discovery of Active Asteroids is to use large multi-colour surveys or catalogs, like SDSS Moving Object Catalog. In this work we analyze the effects of faint dust comae on asteroid spectra and then use it to investigate the effects that a faint dust comae would have over the spectrum, magnitude, and radial profile of asteroids.

CTCF Occupation of the Herpes Simplex Virus 1 Genome Is Disrupted at Early Times Postreactivation in a Transcription-Dependent Manner

PubMed Central

Ertel, Monica K.; Cammarata, Amy L.; Hron, Rebecca J.

2012-01-01

In herpes simplex virus 1 (HSV-1), binding clusters enriched in CTCF during latency have been previously identified. We hypothesized that CTCF binding to CTCF clusters in HSV-1 would be disrupted in a reactivation event. To investigate, CTCF occupation of three CTCF binding clusters in HSV-1 was analyzed following sodium butyrate (NaB)- and explant-induced reactivation in the mouse. Our data show that the CTCF domains positioned within the HSV-1 genome, specifically around the latency-associated transcript (LAT) and ICP0 and ICP4 regions of the genome, lose CTCF occupancy following the application of reactivation stimuli in wild-type virus. We also found that CTCF binding clusters upstream of the ICP0 and ICP4 promoters both function as classical insulators capable of acting as enhancer blockers of the LAT enhancer. Finally, our results suggest that CTCF occupation of domains in HSV-1 may be differentially regulated both during latency and at early times following reactivation by the presence of lytic transcripts and further implicate epigenetic regulation of HSV-1 as a critical component of the latency-reactivation transition. PMID:22973047

Requirements for efficient cell-type proportioning: regulatory timescales, stochasticity and lateral inhibition

NASA Astrophysics Data System (ADS)

Pfeuty, B.; Kaneko, K.

2016-04-01

The proper functioning of multicellular organisms requires the robust establishment of precise proportions between distinct cell types. This developmental differentiation process typically involves intracellular regulatory and stochastic mechanisms to generate cell-fate diversity as well as intercellular signaling mechanisms to coordinate cell-fate decisions at tissue level. We thus surmise that key insights about the developmental regulation of cell-type proportion can be captured by the modeling study of clustering dynamics in population of inhibitory-coupled noisy bistable systems. This general class of dynamical system is shown to exhibit a very stable two-cluster state, but also metastability, collective oscillations or noise-induced state hopping, which can prevent from timely and reliably reaching a robust and well-proportioned clustered state. To circumvent these obstacles or to avoid fine-tuning, we highlight a general strategy based on dual-time positive feedback loops, such as mediated through transcriptional versus epigenetic mechanisms, which improves proportion regulation by coordinating early and flexible lineage priming with late and firm commitment. This result sheds new light on the respective and cooperative roles of multiple regulatory feedback, stochasticity and lateral inhibition in developmental dynamics.

M Dwarf Rotation from the K2 Young Clusters to the Field. I. A Mass-Rotation Correlation at 10 Myr

NASA Astrophysics Data System (ADS)

Somers, Garrett; Stauffer, John; Rebull, Luisa; Cody, Ann Marie; Pinsonneault, Marc

2017-12-01

Recent observations of the low-mass (0.1-0.6 {M}⊙ ) rotation distributions of the Pleiades and Praesepe clusters have revealed a ubiquitous correlation between mass and rotation, such that late M dwarfs rotate an order-of-magnitude faster than early M dwarfs. In this paper, we demonstrate that this mass-rotation correlation is present in the 10 Myr Upper Scorpius association, as revealed by new K2 rotation measurements. Using rotational evolution models, we show that the low-mass rotation distribution of the 125 Myr Pleiades cluster can only be produced if it hosted an equally strong mass-rotation correlation at 10 Myr. This suggests that physical processes important in the early pre-main sequence (PMS; star formation, accretion, disk-locking) are primarily responsible for the M dwarf rotation morphology, and not quirks of later angular momentum (AM) evolution. Such early mass trends must be taken into account when constructing initial conditions for future studies of stellar rotation. Finally, we show that the average M star loses ˜25%-40% of its AM between 10 and 125 Myr, a figure accurately and generically predicted by modern solar-calibrated wind models. Their success rules out a lossless PMS and validates the extrapolation of magnetic wind laws designed for solar-type stars to the low-mass regime at early times.

Chemical and Hydrodynamical Models of Cometary Comae

NASA Technical Reports Server (NTRS)

Charnley, Steven

2012-01-01

Multi-fluid modelling of the outflowing gases which sublimate from cometary nuclei as they approach the Sun is necessary for understanding the important physical and chemical processes occurring in this complex plasma. Coma chemistry models can be employed to interpret observational data and to ultimately determine chemical composition and structure of the nuclear ices and dust. We describe a combined chemical and hydrodynamical model [1] in which differential equations for the chemical abundances and the energy balance are solved as a function of distance from the cometary nucleus. The presence of negative ions (anions) in cometary comae is known from Giotto mass spectrometry of 1P/Halley. The anions O(-), OH(-), C(-), CH(-) and CN(-) have been detected, as well as unidentified anions with masses 22-65 and 85-110 amu [2]. Organic molecular anions such as C4H(-) and C6H(-) are known to have a significant impact on the charge balance of interstellar clouds and circumstellar envelopes and have been shown to act as catalysts for the gas-phase synthesis of larger hydrocarbon molecules in the ISM, but their importance in cometary comae has not yet been fully explored. We present details of new models for the chemistry of cometary comae that include atomic and molecular anions and calculate the impact of these anions on the coma physics and chemistry af the coma.

Jet Morphology and Coma Analysis of Comet 103P/Hartley 2

NASA Astrophysics Data System (ADS)

Vaughan, Charles M.; Pierce, Donna M.; Cochran, Anita L.

2017-12-01

Spectral data for the coma of Hartley 2 were acquired across four nights in late 2010 using an integral field spectrometer at McDonald Observatory. For the 30 observations during these four nights, we detected five radical species in the coma: C2, C3, CH, CN, and NH2. Using division by azimuthal mean and division by radial profile, we enhanced 150 images of the coma to reveal subtle coma structure. These images revealed noticeable temporal evolution and spatial variations between species. To quantify the observed variation between species, we partitioned the coma and used analysis of variance (ANOVA) techniques to provide a statistical basis for heterogeneity. Nearly every ANOVA test indicated a spatially diverse distribution in the coma when considering all species collectively. To examine the temporal behavior, we used the works by Belton et al., Thomas et al., and Bruck Syal et al. to predict nucleus orientation and active jet directions at our observation times. Several of these reported jet sites correlated to high radical concentrations, and the sites on the smaller lobe are more closely associated with high radical concentrations. Lastly, we provide constraints for the suspect parent molecules of the detected radicals, and we propose that photolysis reactions occurring at or near extended icy grains are a source for the more enigmatic radicals, such as C3.

First CT findings and improvement in GOS and GOSE scores 6 and 12 months after severe traumatic brain injury.

PubMed

Corral, Luisa; Herrero, José Ignacio; Monfort, José Luis; Ventura, José Luis; Javierre, Casimiro F; Juncadella, Montserrat; García-Huete, Lucía; Bartolomé, Carlos; Gabarrós, Andreu

2009-05-01

To analyse the association between individual initial computerized tomography (CT) scan characteristics and Glasgow Outcome Scale (GOS) and Extended Glasgow Outcome Scale (GOSE) improvement between 6 months and 1 year. Two hundred and twenty-four adult patients with severe traumatic brain injury and Glasgow Coma Scale (GCS) score of 8 or less who were admitted to an intensive care unit were studied. GOS and GOSE scores were obtained 6 and 12 months after injury in 203 subjects. Patients were predominantly male (84%) and median age was 35 years. Traumatic Coma Data Bank (TCDB) CT classification was associated with GOS/GOSE improvement between 6 months and 1 year, with diffuse injury type I, type II and evacuated mass improving more than diffuse injury type III, type IV and non-evacuated mass; for GOS 43/155 (28%) vs 3/48 (6%) (chi(2) = 9.66, p < 0.01) and for GOSE 71/155 (46%) vs 7/48 (15%) (chi(2) = 15.1, p < 0.01). CT individual abnormalities were not associated with GOS/GOSE improvement, with the exception of subarachnoid haemorrhage, which showed a negative association with GOSE improvement (chi(2) = 4.08, p < 0.05). TCDB CT scan classification and subarachnoid haemorrhage were associated with GOS/GOSE improvement from 6-12 months, but individual CT abnormalities were not associated.

The Last Gasp of Gas Giant Planet Formation: A Spitzer Study of the 5 Myr Old Cluster NGC 2362

NASA Astrophysics Data System (ADS)

Currie, Thayne; Lada, Charles J.; Plavchan, Peter; Robitaille, Thomas P.; Irwin, Jonathan; Kenyon, Scott J.

2009-06-01

Expanding upon the Infrared Array Camera (IRAC) survey from Dahm & Hillenbrand, we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5 Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically thin IR excess emission at λ >= 24 μm consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical "transition disks") and "homologously depleted" disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, in agreement with previous results, we find that multiple paths for the primordial-to-debris disk transition exist. Because these "evolved primordial disks" greatly outnumber primordial disks, our results undermine standard arguments in favor of a lsim105 yr timescale for the transition based on data from Taurus-Auriga. Because the typical transition timescale is far longer than 105 yr, these data also appear to rule out standard ultraviolet photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant planet formation. Consistent with Currie et al., the luminosity of 24 μm emission in debris disks due to planet formation peaks at ≈10-20 Myr. If the gas and dust in disks evolve on similar timescales, the formation timescale for gas giant planets surrounding early-type, high/intermediate-mass (gsim1.4 M sun) stars is likely 1-5 Myr. Most solar/subsolar-mass stars detected by Spitzer have SEDs that indicate their disks may be actively leaving the primordial disk phase. Thus, gas giant planet formation may also occur by ~5 Myr around solar/subsolar-mass stars as well.

Asymmetric Spherical Coupled Escape Probability: Model and Results for Optically Thick Cometary Comae

NASA Astrophysics Data System (ADS)

Gersch, Alan; A'Hearn, M. F.

2012-05-01

We have adapted the Coupled Escape Probability method of radiative transfer calculations for use in asymmetrical spherical situations and applied it to modeling molecular emission spectra of potentially optically thick cometary comae. Recent space missions (e.g. Deep Impact & EPOXI) have provided spectra from comets of unprecedented spatial resolution of the regions of the coma near the nucleus, where the coma may be optically thick. Currently active missions (e.g. Rosetta) and hopefully more in the future will continue the trend and demonstrate the need for better modeling of comae with optical depth effects included. Here we present a brief description of our model and results of interest for cometary studies, especially for space based observations. Although primarily motivated by the need for comet modeling, our (asymmetric spherical) radiative transfer model could be used for studying other astrophysical phenomena as well.

A Case of Myxedema Coma Presenting as a Brain Stem Infarct in a 74-Year-Old Korean Woman

PubMed Central

Ahn, Ji Yun; Kwon, Hyuk-Sool; Ahn, Hee Chol

2010-01-01

Myxedema coma is the extreme form of untreated hypothyroidism. In reality, few patients present comatose with severe myxedema. We describe a patient with myxedema coma which was initially misdiagnosed as a brain stem infarct. She presented to the hospital with alteration of the mental status, generalized edema, hypothermia, hypoventilation, and hypotension. Initially her brain stem reflexes were absent. After respiratory and circulatory support, her neurologic status was not improved soon. The diagnosis of myxedema coma was often missed or delayed due to various clinical findings and concomitant medical condition and precipitating factors. It is more difficult to diagnose when a patient has no medical history of hypothyroidism. A high index of clinical suspicion can make a timely diagnosis and initiate appropriate treatment. We report this case to alert clinicians considering diagnosis of myxedema coma in patients with severe decompensated metabolic state including mental change. PMID:20808690

Severe congestive heart failure patient on amiodarone presenting with myxedemic coma: a case report.

PubMed

Shaheen, Mazen

2009-01-01

This is a case report of myxedema coma secondary to amiodarone-induced hypothyroidism in a patient with severe congestive heart failure (CHF). To our knowledge and after reviewing the literature there is one case report of myxedema coma during long term amiodarone therapy. Myxedema coma is a life threatening condition that carries a mortality reaching as high as 20% with treatment. The condition is treated with intravenous thyroxine (T4) or intravenous tri-iodo-thyronine (T3). Patients with CHF on amiodarone may suffer serious morbidity and mortality from hypothyroidism, and thus may deserve closer follow up for thyroid stimulating hormone (TSH) levels. This case report carries an important clinical application given the frequent usage of amiodarone among CHF patients. The myriad clinical presentation of myxedema coma and its serious morbidity and mortality stresses the need to suspect this clinical syndrome among CHF patients presenting with hypotension, weakness or other unexplained symptoms.

A case of myxedema coma presenting as a brain stem infarct in a 74-year-old Korean woman.

PubMed

Ahn, Ji Yun; Kwon, Hyuk-Sool; Ahn, Hee Chol; Sohn, You Dong

2010-09-01

Myxedema coma is the extreme form of untreated hypothyroidism. In reality, few patients present comatose with severe myxedema. We describe a patient with myxedema coma which was initially misdiagnosed as a brain stem infarct. She presented to the hospital with alteration of the mental status, generalized edema, hypothermia, hypoventilation, and hypotension. Initially her brain stem reflexes were absent. After respiratory and circulatory support, her neurologic status was not improved soon. The diagnosis of myxedema coma was often missed or delayed due to various clinical findings and concomitant medical condition and precipitating factors. It is more difficult to diagnose when a patient has no medical history of hypothyroidism. A high index of clinical suspicion can make a timely diagnosis and initiate appropriate treatment. We report this case to alert clinicians considering diagnosis of myxedema coma in patients with severe decompensated metabolic state including mental change.

[Prognostic value of EEG in acute posttraumatic coma (author's transl)].

PubMed

Walser, H; Friedli, W; Glinz, W

1981-12-01

To evaluate the prognostic power of a single EEG-record, the recordings of 50 patients with posttraumatic coma performed within 48 hours after the injury were compared with the outcome after 6 months. A 5-point scale comprising 2 EEG-patterns being notorious for their dismal prognostic significance (suppression bursts, alpha-coma) and changes of vigilance were used as a mean of visual assessment of the recordings. In 24 out of the 28 patients with a bad outcome, the EEG had shown the patterns of category I, II and III (suppression bursts, alpha coma, no changes of vigilance). Of the 22 patients with a good outcome, the EEG had been classified as IV or V (clearly discernible changes of vigilance, sleep patterns). Further findings of particular dismal prognostic significance were focal epileptic discharges, as 9 out of the 11 patients with this EEG pattern had not survived the posttraumatic coma for more than 6 months.

An Extreme Protocluster of Luminous Dusty Starbursts in the Early Universe

NASA Astrophysics Data System (ADS)

Oteo, I.; Ivison, R. J.; Dunne, L.; Manilla-Robles, A.; Maddox, S.; Lewis, A. J. R.; de Zotti, G.; Bremer, M.; Clements, D. L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Greenslade, J.; Omont, A.; Perez–Fournón, I.; Riechers, D.; Scott, D.; van der Werf, P.; Weiss, A.; Zhang, Z.-Y.

2018-03-01

We report the identification of an extreme protocluster of galaxies in the early universe whose core (nicknamed Distant Red Core, DRC, because of its very red color in Herschel SPIRE bands) is formed by at least 10 dusty star-forming galaxies (DSFGs), spectroscopically confirmed to lie at {z}spec}=4.002 via detection of [C I](1–0), 12CO(6–5), 12CO(4–3), 12CO(2–1), and {{{H}}}2{{O}}({2}11{--}{2}02) emission lines with ALMA and ATCA. These DSFGs are distributed over a 260 {kpc}× 310 {kpc} region and have a collective obscured star formation rate (SFR) of ∼ 6500 {M}ȯ {yr}}-1, considerably higher than those seen before in any protocluster at z≳ 4. Most of the star formation is taking place in luminous DSFGs since no Lyα emitters are detected in the protocluster core, apart from a Lyα blob located next to one of the DRC components, extending over 60 {kpc}. The total obscured SFR of the protocluster could rise to {SFR}∼ {{14,400}} {M}ȯ {yr}}-1 if all the members of an overdensity of bright DSFGs discovered around DRC in a wide-field Large APEX BOlometer CAmera 870 μm image are part of the same structure. [C I](1–0) emission reveals that DRC has a total molecular gas mass of at least {M}{{{H}}2}∼ 6.6× {10}11 {M}ȯ , and its total halo mass could be as high as ∼ 4.4× {10}13 {M}ȯ , indicating that it is the likely progenitor of a cluster at least as massive as Coma at z = 0.

Large Outbreaks of Ciguatera after Consumption of Brown Marbled Grouper

PubMed Central

Chan, Thomas Y. K.

2014-01-01

Brown marbled grouper (Epinephelus fuscoguttatus) is an apex predator from coral reefs of the Indo-Pacific region. All five published case series of ciguatera after consumption of brown marbled grouper were reviewed to characterize the types, severity and chronicity of ciguatera symptoms associated with its consumption. Three of these case series were from large outbreaks affecting over 100–200 subjects who had eaten this reef fish served at banquets. Affected subjects generally developed a combination of gastrointestinal, neurological and, less commonly, cardiovascular symptoms. Gastrointestinal symptoms occurred early and generally subsided in 1–2 days. Some neurological symptoms (e.g., paresthesia of four limbs) could last for weeks or months. Sinus bradycardia and hypotension occurred early, but could be severe and prolonged, necessitating the timely use of intravenous fluids, atropine and dopamine. Other cardiovascular and neurological features included atrial ectopics, ventricular ectopics, dyspnea, chest tightness, PR interval >0.2 s, ST segment changes, polymyositis and coma. Concomitant alcohol consumption was associated with a much higher risk of developing bradycardia, hypotension and altered skin sensation. The public should realize that consumption of the high-risk fish (especially the ciguatoxin-rich parts and together with alcohol use) and repeated ciguatoxin exposures will result in more severe and chronic illness. PMID:25019942

Large outbreaks of ciguatera after consumption of brown marbled grouper.

PubMed

Chan, Thomas Y K

2014-07-11

Brown marbled grouper (Epinephelus fuscoguttatus) is an apex predator from coral reefs of the Indo-Pacific region. All five published case series of ciguatera after consumption of brown marbled grouper were reviewed to characterize the types, severity and chronicity of ciguatera symptoms associated with its consumption. Three of these case series were from large outbreaks affecting over 100-200 subjects who had eaten this reef fish served at banquets. Affected subjects generally developed a combination of gastrointestinal, neurological and, less commonly, cardiovascular symptoms. Gastrointestinal symptoms occurred early and generally subsided in 1-2 days. Some neurological symptoms (e.g., paresthesia of four limbs) could last for weeks or months. Sinus bradycardia and hypotension occurred early, but could be severe and prolonged, necessitating the timely use of intravenous fluids, atropine and dopamine. Other cardiovascular and neurological features included atrial ectopics, ventricular ectopics, dyspnea, chest tightness, PR interval >0.2 s, ST segment changes, polymyositis and coma. Concomitant alcohol consumption was associated with a much higher risk of developing bradycardia, hypotension and altered skin sensation. The public should realize that consumption of the high-risk fish (especially the ciguatoxin-rich parts and together with alcohol use) and repeated ciguatoxin exposures will result in more severe and chronic illness.

The hot corona of YY Mensae

NASA Technical Reports Server (NTRS)

Guedel, M.; Guinan, E. F.; Skinner, S. L.; Linsky, J. L.

1996-01-01

The results of a long time series of Rosat position sensitive proportional counter (PSPC) pointings are reported on together with the first Advanced Satellite for Cosmology and Astrophysics (ASCA) observation of the FK Comae-type star YY Mensae. This star reveals a hot dominant plasma of up to 3 keV, with less material at 0.7 keV.

ROSAT observations of compact groups of galaxies

NASA Technical Reports Server (NTRS)

Pildis, Rachel A.; Bregman, Joel N.; Evrard, August E.

1995-01-01

We have systematically analyzed a sample of 13 new and archival ROSAT Position Sensitive Proportional Counter (PSPC) observations of compact groups of galaxies: 12 Hickson compact groups plus the NCG 2300 group. We find that approximately two-thirds of the groups have extended X-ray emission and, in four of these, the emission is resolved into diffuse emission from gas at a temperature of kT approximately 1 keV in the group potential. All but one of the groups with extended emission have a spiral fraction of less than 50%. The baryon fraction of groups with diffuse emission is 5%-19%, similar to the values in clusters of galaxies. However, with a single exception (HCG 62), the gas-to-stellar mass ratio in our groups has a median value near 5%, somewhat greater than the values for individual early-type galaxies and two orders of magnitude than in clusters of galaxies. The X-ray luminosities of individual group galaxies are comparable to those of similar field galaxies, although the L(sub X)-L(sub B) relation for early-type galaxies may be flatter in compact groups than in the field.

THE EFFECT OF SECOND-GENERATION POPULATIONS ON THE INTEGRATED COLORS OF METAL-RICH GLOBULAR CLUSTERS IN EARLY-TYPE GALAXIES

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

Chung, Chul; Lee, Sang-Yoon; Yoon, Suk-Jin

2013-05-20

The mean color of globular clusters (GCs) in early-type galaxies is in general bluer than the integrated color of halo field stars in host galaxies. Metal-rich GCs often appear more associated with field stars than metal-poor GCs, yet show bluer colors than their host galaxy light. Motivated by the discovery of multiple stellar populations in Milky Way GCs, we present a new scenario in which the presence of second-generation (SG) stars in GCs is responsible for the color discrepancy between metal-rich GCs and field stars. The model assumes that the SG populations have an enhanced helium abundance as evidenced bymore » observations, and it gives a good explanation of the bluer optical colors of metal-rich GCs than field stars as well as strong Balmer lines and blue UV colors of metal-rich GCs. Ours may be complementary to the recent scenario suggesting the difference in stellar mass functions (MFs) as an origin for the GC-to-star color offset. A quantitative comparison is given between the SG and MF models.« less

Abundant molecular oxygen in the coma of comet 67P/Churyumov-Gerasimenko.

PubMed

Bieler, A; Altwegg, K; Balsiger, H; Bar-Nun, A; Berthelier, J-J; Bochsler, P; Briois, C; Calmonte, U; Combi, M; De Keyser, J; van Dishoeck, E F; Fiethe, B; Fuselier, S A; Gasc, S; Gombosi, T I; Hansen, K C; Hässig, M; Jäckel, A; Kopp, E; Korth, A; Le Roy, L; Mall, U; Maggiolo, R; Marty, B; Mousis, O; Owen, T; Rème, H; Rubin, M; Sémon, T; Tzou, C-Y; Waite, J H; Walsh, C; Wurz, P

2015-10-29

The composition of the neutral gas comas of most comets is dominated by H2O, CO and CO2, typically comprising as much as 95 per cent of the total gas density. In addition, cometary comas have been found to contain a rich array of other molecules, including sulfuric compounds and complex hydrocarbons. Molecular oxygen (O2), however, despite its detection on other icy bodies such as the moons of Jupiter and Saturn, has remained undetected in cometary comas. Here we report in situ measurement of O2 in the coma of comet 67P/Churyumov-Gerasimenko, with local abundances ranging from one per cent to ten per cent relative to H2O and with a mean value of 3.80 ± 0.85 per cent. Our observations indicate that the O2/H2O ratio is isotropic in the coma and does not change systematically with heliocentric distance. This suggests that primordial O2 was incorporated into the nucleus during the comet's formation, which is unexpected given the low upper limits from remote sensing observations. Current Solar System formation models do not predict conditions that would allow this to occur.

Factors predisposing to coma and delirium: fentanyl and midazolam exposure; CYP3A5, ABCB1, and ABCG2 genetic polymorphisms; and inflammatory factors.

PubMed

Skrobik, Yoanna; Leger, Caroline; Cossette, Mariève; Michaud, Veronique; Turgeon, Jacques

2013-04-01

Delirium and sedative-induced coma are described as incremental manifestations of cerebral dysfunction. Both may be associated with sedative or opiate doses and pharmacokinetic or pharmacogenetic variables, such as drug plasma levels (exposure), drug metabolism, and/or their transport across the blood-brain barrier. To compare biological and drug treatment characteristics in patients with coma and/or delirium while in the ICU. In 99 patients receiving IV fentanyl, midazolam, or both, we evaluated drug doses, covariates likely to influence drug effects (age, body mass index, and renal and hepatic dysfunction); delirium risk factors; concomitant administration of CYP3A and P-glycoprotein substrates/inhibitors; ABCB1, ABCG2, and CYP3A5 genetic polymorphisms; and fentanyl and midazolam plasma levels. Delirium and coma were evaluated daily. In patients with only coma (n=15), only delirium (n=7), and neither ever (n=14), we measured plasma levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-1RA, IL-6, IL-8, IL-10, IL-17,macrophage inflammatory protein-1β, and monocyte chemotactic protein-1. Time to first coma was associated with fentanyl and midazolam doses (p=0.03 and p=0.01, respectively). The number of days in coma was associated with the number of days of coadministration of CYP3A inhibitors (r=0.30; p=0.006). Plasma levels of fentanyl were higher in patients with clinical coma (3.7±4.7 vs. 2.0±1.8 ng/mL, p=0.0001) as were midazolam plasma levels (1050±2232 vs. 168±249 ng/mL, p=0.0001). Delirium occurrence was unrelated to midazolam administration, cumulative doses, or serum levels. Days with delirium were associated with days of coadministration of P-glycoprotein inhibitor (r=0.35; p=0.0004). Delirious patients had higher levels of the inflammatory mediator IL-6 than comatose patients (129.3 vs. 35.0 pg/mL, p=0.05). Coma is associated with fentanyl and midazolam exposure; delirium is unrelated to midazolam and may be linked to inflammatory status. These data suggest that iatrogenic coma and delirium are not mechanistically linked.

The 67P/Churyumov-Gerasimenko observation campaign in support of the Rosetta mission.

PubMed

Snodgrass, C; A'Hearn, M F; Aceituno, F; Afanasiev, V; Bagnulo, S; Bauer, J; Bergond, G; Besse, S; Biver, N; Bodewits, D; Boehnhardt, H; Bonev, B P; Borisov, G; Carry, B; Casanova, V; Cochran, A; Conn, B C; Davidsson, B; Davies, J K; de León, J; de Mooij, E; de Val-Borro, M; Delacruz, M; DiSanti, M A; Drew, J E; Duffard, R; Edberg, N J T; Faggi, S; Feaga, L; Fitzsimmons, A; Fujiwara, H; Gibb, E L; Gillon, M; Green, S F; Guijarro, A; Guilbert-Lepoutre, A; Gutiérrez, P J; Hadamcik, E; Hainaut, O; Haque, S; Hedrosa, R; Hines, D; Hopp, U; Hoyo, F; Hutsemékers, D; Hyland, M; Ivanova, O; Jehin, E; Jones, G H; Keane, J V; Kelley, M S P; Kiselev, N; Kleyna, J; Kluge, M; Knight, M M; Kokotanekova, R; Koschny, D; Kramer, E A; López-Moreno, J J; Lacerda, P; Lara, L M; Lasue, J; Lehto, H J; Levasseur-Regourd, A C; Licandro, J; Lin, Z Y; Lister, T; Lowry, S C; Mainzer, A; Manfroid, J; Marchant, J; McKay, A J; McNeill, A; Meech, K J; Micheli, M; Mohammed, I; Monguió, M; Moreno, F; Muñoz, O; Mumma, M J; Nikolov, P; Opitom, C; Ortiz, J L; Paganini, L; Pajuelo, M; Pozuelos, F J; Protopapa, S; Pursimo, T; Rajkumar, B; Ramanjooloo, Y; Ramos, E; Ries, C; Riffeser, A; Rosenbush, V; Rousselot, P; Ryan, E L; Santos-Sanz, P; Schleicher, D G; Schmidt, M; Schulz, R; Sen, A K; Somero, A; Sota, A; Stinson, A; Sunshine, J M; Thompson, A; Tozzi, G P; Tubiana, C; Villanueva, G L; Wang, X; Wooden, D H; Yagi, M; Yang, B; Zaprudin, B; Zegmott, T J

2017-07-13

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Self-similar hierarchical energetics in the ICM of massive galaxy clusters

NASA Astrophysics Data System (ADS)

Miniati, Francesco; Beresnyak, Andrey

Massive galaxy clusters (GC) are filled with a hot, turbulent and magnetised intra-cluster medium (ICM). They are still forming under the action of gravitational instability, which drives supersonic mass accretion flows. These partially dissipate into heat through a complex network of large scale shocks, and partly excite giant turbulent eddies and cascade. Turbulence dissipation not only contributes to heating of the ICM but also amplifies magnetic energy by way of dynamo action. The pattern of gravitational energy turning into kinetic, thermal, turbulent and magnetic is a fundamental feature of GC hydrodynamics but quantitative modelling has remained a challenge. In this contribution we present results from a recent high resolution, fully cosmological numerical simulation of a massive Coma-like galaxy cluster in which the time dependent turbulent motions of the ICM are resolved (Miniati 2014) and their statistical properties are quantified for the first time (Miniati 2015, Beresnyak & Miniati 2015). We combine these results with independent state-of-the art numerical simulations of MHD turbulence (Beresnyak 2012), which shows that in the nonlinear regime of turbulent dynamo (for magnetic Prandtl numbers>~ 1) the growth rate of the magnetic energy corresponds to a fraction CE ~= 4 - 5 × 10-2 of the turbulent dissipation rate. We thus determine without adjustable parameters the thermal, turbulent and magnetic history of giant GC (Miniati & Beresnyak 2015). We find that the energy components of the ICM are ordered according to a permanent hierarchy, in which the sonic Mach number at the turbulent injection scale is of order unity, the beta of the plasma of order forty and the ratio of turbulent injection scale to Alfvén scale is of order one hundred. These dimensionless numbers remain virtually unaltered throughout the cluster's history, despite evolution of each individual component and the drive towards equipartition of the turbulent dynamo, thus revealing a new type of self-similarity in cosmology. Their specific values, while consistent with current data, indicate that thermal energy dominates the ICM energetics and the turbulent dynamo is always far from saturation, unlike the condition in other familiar astrophysical fluids (stars, interstellar medium of galaxies, compact objects, etc.). In addition, they have important physical meaning as their specific values encodes information about the efficiency of turbulent heating (the fraction of ICM thermal energy produced by turbulent dissipation) and the efficiency of dynamo action in the ICM (CE ).

A Quantitative Analysis Of Pre-Processing In The Coma And Perseus-Pisces Superclusters Using Galex And Wise Survey Data

NASA Astrophysics Data System (ADS)

Yun, Min

Studies of massive galaxy clusters and groups at redshifts below 1 typically find environments with little-to-no star formation activity, in sharp contrast with the field. Over-dense regions are dominated by passively-evolving spheroidal (S0) and elliptical galaxies, whereas galaxies in the field tend to have spiral morphologies, younger stellar populations, and systematically higher star formation rates. Studies of the galaxy populations of clusters and massive galaxy groups have found that the increase in the fraction of spirals at higher redshifts corresponds to a decline in the fraction of S0 galaxies, which strongly suggests that field spirals are transformed into S0 galaxies at some point in their transition between field and cluster regions. This transformation necessarily involves an increase in the stellar content of the bulge relative to the disk, and then a removal of disk gas accompanied by either a rapid or gradual decline in star formation to eventually produce a red, spheroidal, passively-evolving S0 galaxy. Deep and wide area cosmological surveys such as the GOODS and COSMOS have shown that both environment and stellar mass play a distinct role in the overall galaxy evolution over a wide redshift range (to z~3). The density-morphology relation and the blue-fraction, first noted in the targeted studies of clusters and groups, also appears to be an extension of the evolutionary trends seen in the field sample. However, the trends seen in these large cosmological surveys should be taken with a caution since they are broad statistical trends of primarily massive galaxies with relatively poor sensitivity on star formation rate (SFR), associated with a relatively narrow range of sparsely sampled galaxy density. This can lead to potentially serious shortcomings when studying the role of environment because many of the physical mechanisms involved may preferentially impact the lower mass galaxies. The dominant physical mechanism(s) responsible for this transformation are still being debated, but the overwhelming evidence has shown that spirals are readily altered in groups or cluster outskirts prior to falling into a galaxy cluster (pre-processing). This implies that the best approach to catch galaxy transformation in the act is to examine galaxies in lower density environments. A complete accounting of star-formation activity for galaxies over a wide range masses and environments is needed to assess which of many possible mechanisms is the dominant cause of galaxy transformation in over-dense regions. The main goal of this proposed study is to examine the SF and quenching activities associated with galaxies using the high spatial resolution of the targeted studies of individual clusters, but covering much larger areas and density ranges (from voids to cluster cores) with the sample statistics approaching those of the cosmological surveys such as COSMOS, using exquisite stellar mass and SFR (both UV and IR) sensitivity. To achieve this, we propose a multi-wavelength study (with a specific emphasis on GALEX and WISE) of the two most prominent large scale structures in the local universe: the Coma and Perseus-Pisces Superclusters. The total sample area covers ~3000 sq. degree and contains about 7000 spectroscopically identified galaxies (from SDSS and archival spectra). In addition, we will evaluate the impacts of the high mass and SFR cut employed by deep cosmological surveys by paring down our sample in stellar mass and SFR (and resulting coarse galaxy density estimates) and examine whether any important insights are missed as a result.

Rosetta/ROSINA observations of the volatiles in the coma of comet 67P/Churyumov-Gerasimenko during the nominal mission

NASA Astrophysics Data System (ADS)

Rubin, M.; Altwegg, K.; Balsiger, H. R.; Berthelier, J. J.; Calmonte, U.; De Keyser, J.; Fiethe, B.; Fuselier, S. A.; Gasc, S.; Gombosi, T. I.; Hässig, M.; Jäckel, A.; Le Roy, L.; Mall, U. A.; Rème, H.; Sémon, T.; Tzou, C. Y.; Wurz, P.

2015-12-01

The European Space Agency's Rosetta spacecraft is in close proximity of comet 67P/Churyumov-Gerasimenko for well over a year now. During this time Rosetta followed the comet from almost 3.5 AU through perihelion at 1.25 AU and away from the Sun again. Part of the scientific payload scrutinizing the comet is the ROSINA experiment, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis. The suite of instruments consists of the Double Focusing Mass Spectrometer DFMS, the Reflectron Time-Of-Flight mass spectrometer RTOF, and the COmet Pressure Sensor COPS. From the combined measurements by ROSINA, the composition and dynamics of the volatiles in the coma of the comet are derived. On 13 August 2015, comet 67P/Churyumov-Gerasimenko reached perihelion, the point along its orbits that is closest to the Sun. Furthermore equinox occurred in May 2015 leading to a change in season - the previous summer hemisphere is now in winter and vice versa. One of the goals of ROSINA is to track the activity of the comet during its apparition and to investigate potential changes in the chemical composition as the spacecraft orbits around the nucleus. In this presentation we will summarize some key findings obtained during the first year and a half of the nominal mission and present first results comparing the pre- and post perihelion neutral gas coma. The goal of these observations is to gather information about the formation and the composition of the comet and ultimately our early Solar System.

Photometric and Spectroscopic Survey of the Cluster [DBS2003] 156 Associated with the H II Region G331.1-0.5

NASA Astrophysics Data System (ADS)

Pinheiro, M. C.; Ortiz, R.; Abraham, Z.; Copetti, M. V. F.

2016-05-01

The Norma section of the Milky Way is especially interesting because it crosses three spiral arms: Sagittarius-Carina, Scutum-Crux and the Norma arm itself. Distance determinations of embedded young stellar clusters can contribute to define the spiral structure in this part of the Galaxy. However, spectrophotometric distances were obtained for only a few of these clusters in Norma. We present a photometric and spectroscopic study in the NIR of the [DBS2003] 156 stellar cluster, associated with the H II region G331.1-0.5. We aim to find the ionizing sources of the H II region and determine its distance. The cluster was observed in the J, H, and {K}{{s}} bands and eight potential massive stars were chosen among the detected sources according to color criteria; subsequent spectroscopy of these candidates was performed with the Ohio State Infrared Imager/Spectrometer spectrograph attached to the Southern Observatory for Astrophysical Research 4.1 m telescope. We identified and classified spectroscopically four early-type stars: IRS 176 (O8 V), IRS 308 (O-type), IRS 310 (O6 V), and IRS 71 (B1 Iab). Based on the proximity of IRS 176 and 308 with the radio continuum emission peaks and their relative positions with respect to the warm dust mid-infrared emission, we concluded that these two stars are the main ionizing sources of the H ii region G331.1-0.5. The mean spectrophotometric distance of IRS 176 and 310 of 3.38 ± 0.58 kpc is similar to that obtained in a previous work for two early-type stars of the neighbor cluster [DBS2003] 157 of 3.29 ± 0.58 kpc. The narrow range of radial velocities of radio sources in the area of the clusters [DBS2003] 156 and 157 and their similar visual extinction indicate that these clusters are physically associated. A common distance of 3.34 ± 0.34 kpc is derived for the system [DBS2003] 156 and 157. Based on observations obtained at the Southern Observatory for Astrophysical Research (SOAR), a joint project of the Ministério de Ciência, Tecnologia e Inovação (MCTI) of the República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC) and the Michigan State University (MSU).

An early, novel illness severity score to predict outcome after cardiac arrest.

PubMed

Rittenberger, Jon C; Tisherman, Samuel A; Holm, Margo B; Guyette, Francis X; Callaway, Clifton W

2011-11-01

Illness severity scores are commonly employed in critically ill patients to predict outcome. To date, prior scores for post-cardiac arrest patients rely on some event-related data. We developed an early, novel post-arrest illness severity score to predict survival, good outcome and development of multiple organ failure (MOF) after cardiac arrest. Retrospective review of data from adults treated after in-hospital or out-of-hospital cardiac arrest in a single tertiary care facility between 1/1/2005 and 12/31/2009. In addition to clinical data, initial illness severity was measured using serial organ function assessment (SOFA) scores and full outline of unresponsiveness (FOUR) scores at hospital or intensive care unit arrival. Outcomes were hospital mortality, good outcome (discharge to home or rehabilitation) and development of multiple organ failure (MOF). Single-variable logistic regression followed by Chi-squared automatic interaction detector (CHAID) was used to determine predictors of outcome. Stepwise multivariate logistic regression was used to determine the independent association between predictors and each outcome. The Hosmer-Lemeshow test was used to evaluate goodness of fit. The n-fold method was used to cross-validate each CHAID analysis and the difference between the misclassification risk estimates was used to determine model fit. Complete data from 457/495 (92%) subjects identified distinct categories of illness severity using combined FOUR motor and brainstem subscales, and combined SOFA cardiovascular and respiratory subscales: I. Awake; II. Moderate coma without cardiorespiratory failure; III. Moderate coma with cardiorespiratory failure; and IV. Severe coma. Survival was independently associated with category (I: OR 58.65; 95% CI 27.78, 123.82; II: OR 14.60; 95% CI 7.34, 29.02; III: OR 10.58; 95% CI 4.86, 23.00). Category was also similarly associated with good outcome and development of MOF. The proportion of subjects in each category changed over time. Initial illness severity explains much of the variation in cardiac arrest outcome. This model provides prognostic information at hospital arrival and may be used to stratify patients in future studies. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Clusters of Insomnia Disorder: An Exploratory Cluster Analysis of Objective Sleep Parameters Reveals Differences in Neurocognitive Functioning, Quantitative EEG, and Heart Rate Variability

PubMed Central

Miller, Christopher B.; Bartlett, Delwyn J.; Mullins, Anna E.; Dodds, Kirsty L.; Gordon, Christopher J.; Kyle, Simon D.; Kim, Jong Won; D'Rozario, Angela L.; Lee, Rico S.C.; Comas, Maria; Marshall, Nathaniel S.; Yee, Brendon J.; Espie, Colin A.; Grunstein, Ronald R.

2016-01-01

Study Objectives: To empirically derive and evaluate potential clusters of Insomnia Disorder through cluster analysis from polysomnography (PSG). We hypothesized that clusters would differ on neurocognitive performance, sleep-onset measures of quantitative (q)-EEG and heart rate variability (HRV). Methods: Research volunteers with Insomnia Disorder (DSM-5) completed a neurocognitive assessment and overnight PSG measures of total sleep time (TST), wake time after sleep onset (WASO), and sleep onset latency (SOL) were used to determine clusters. Results: From 96 volunteers with Insomnia Disorder, cluster analysis derived at least two clusters from objective sleep parameters: Insomnia with normal objective sleep duration (I-NSD: n = 53) and Insomnia with short sleep duration (I-SSD: n = 43). At sleep onset, differences in HRV between I-NSD and I-SSD clusters suggest attenuated parasympathetic activity in I-SSD (P < 0.05). Preliminary work suggested three clusters by retaining the I-NSD and splitting the I-SSD cluster into two: I-SSD A (n = 29): defined by high WASO and I-SSD B (n = 14): a second I-SSD cluster with high SOL and medium WASO. The I-SSD B cluster performed worse than I-SSD A and I-NSD for sustained attention (P ≤ 0.05). In an exploratory analysis, q-EEG revealed reduced spectral power also in I-SSD B before (Delta, Alpha, Beta-1) and after sleep-onset (Beta-2) compared to I-SSD A and I-NSD (P ≤ 0.05). Conclusions: Two insomnia clusters derived from cluster analysis differ in sleep onset HRV. Preliminary data suggest evidence for three clusters in insomnia with differences for sustained attention and sleep-onset q-EEG. Clinical Trial Registration: Insomnia 100 sleep study: Australia New Zealand Clinical Trials Registry (ANZCTR) identification number 12612000049875. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347742. Citation: Miller CB, Bartlett DJ, Mullins AE, Dodds KL, Gordon CJ, Kyle SD, Kim JW, D'Rozario AL, Lee RS, Comas M, Marshall NS, Yee BJ, Espie CA, Grunstein RR. Clusters of Insomnia Disorder: an exploratory cluster analysis of objective sleep parameters reveals differences in neurocognitive functioning, quantitative EEG, and heart rate variability. SLEEP 2016;39(11):1993–2004. PMID:27568796

Coma morphology of comet 67P controlled by insolation over irregular nucleus

NASA Astrophysics Data System (ADS)

Shi, X.; Hu, X.; Mottola, S.; Sierks, H.; Keller, H. U.; Rose, M.; Güttler, C.; Fulle, M.; Fornasier, S.; Agarwal, J.; Pajola, M.; Tubiana, C.; Bodewits, D.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Barucci, M. A.; Bertaux, J.-L.; Bertini, I.; Boudreault, S.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Deller, J.; Groussin, O.; Gutiérrez, P. J.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Knollenberg, J.; Kovacs, G.; Kramm, J.-R.; Kührt, E.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez-Moreno, J. J.; Marzari, F.; Naletto, G.; Oklay, N.; Toth, I.; Vincent, J.-B.

2018-05-01

While the structural complexity of cometary comae is already recognizable from telescopic observations1, the innermost region, within a few radii of the nucleus, was not resolved until spacecraft exploration became a reality2,3. The dust coma displays jet-like features of enhanced brightness superposed on a diffuse background1,4,5. Some features can be traced to specific areas on the nucleus, and result conceivably from locally enhanced outgassing and/or dust emission6-8. However, diffuse or even uniform activity over topographic concavity can converge to produce jet-like features9,10. Therefore, linking observed coma morphology to the distribution of activity on the nucleus is difficult11,12. Here, we study the emergence of dust activity at sunrise on comet 67P/Churyumov-Gerasimenko using high-resolution, stereo images from the OSIRIS camera onboard the Rosetta spacecraft, where the sources and formation of the jet-like features are resolved. We perform numerical simulations to show that the ambient dust coma is driven by pervasive but non-uniform water outgassing from the homogeneous surface layer. Physical collimations of gas and dust flows occur at local maxima of insolation and also via topographic focusing. Coma structures are projected to exhibit jet-like features that vary with the perspective of the observer. For an irregular comet such as 67P/Churyumov-Gerasimenko, near-nucleus coma structures can be concealed in the shadow of the nucleus, which further complicates the picture.

Lightcurves and Period Changes for Type II Cepheids in the Globular Cluster M13 (Abstract)

NASA Astrophysics Data System (ADS)

Smith, H. A.; Anderson, M.; Osborn, W.; Layden, A.; Kopacki, G.; Pritzl, B.; Kelley, A.; McBride, K.; Alexander, M.; Kuehn, C.; Kilian, A.; King, E.; Carbajal, D.; Lusting, R.; De Lee, N.

2015-12-01

(Abstract only) B, V, and Cousins I-band light curves have been observed for the type II Cepheids V1, V2, and V6 in the globular cluster M13. These are relatively short period, BL Her-type Cepheids, with periods of 1.5, 5.1, and 2.1 days, respectively. Additional observations of V2 have been obtained from early photographic plates in the Yerkes Observatory archive. Long term period changes of these Cepheids have been determined by combining recent photometry with earlier observations that now extend back for more than a century. The observed period changes for V1, V2, and V6 are compared with the predictions of stellar evolution theory, under the assumption that the progenitors of the Cepheids were stars that at one time were on the blue horizontal branch.

Predictors of outcome in myxoedema coma: a study from a tertiary care centre.

PubMed

Dutta, Pinaki; Bhansali, Anil; Masoodi, Shriq Rashid; Bhadada, Sanjay; Sharma, Navneet; Rajput, Rajesh

2008-01-01

With the easy availability of thyroid hormone assays, thyroid disorders are now recognised even in a subclinical state. However, patients are still seen with advanced manifestations of the disease, particularly in developing countries. This observational study analysed the predictors of outcome in patients with myxoedema coma and tested the validity of different modules to define morbidity and mortality in these patients. Twenty-three consecutive patients with myxoedema coma who presented from January 1999 to August 2006 were studied. The thyroid function test and random serum cortisol were measured in all patients at the time of admission. Patients were given oral or intravenous (i.v.) thyroxine with intention to treat with the latter according to availability. Various modules that predict outcome, including Glasgow Coma Scale (GCS), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and Sequential Organ Failure Assessment (SOFA) score, were analysed. SOFA score was repeated every 2 days until the time of discharge or demise. Twenty-three patients (20 women; 87%) of 59.5 +/- 14.4 years of age (range, 30 to 89 years) were seen during the study period. Nine (39%) patients were diagnosed with hypothyroidism for the first time at the time of presentation of myxoedema coma, whereas 14 (70%) were diagnosed with hypothyroidism previously. However, the treatment defaulters presented early to the hospital and had more severe manifestations than de novo subjects. Nineteen (82%) had thyroprivic (primary) and 4 (17%) had trophoprivic (secondary) hypothyroidism. Fifteen (65%) patients presented in the winter and in 17 (74%) sepsis was the major accompanying comorbidity. Twelve (52%) had a history of diuretic use, thereby delaying the initial diagnosis. Patients who received oral L-thyroxine had no difference in outcome from those receiving i.v. thyroxine. Twelve (52%) subjects died and sepsis was the predominant cause of death. Various predictors of mortality included hypotension (p = 0.01) and bradycardia (p = 0.03) at presentation, need for mechanical ventilation (p = 0.00), hypothermia unresponsive to treatment (p = 0.01), sepsis (p = 0.01), intake of sedative drugs (p = 0.02), lower GCS (p = 0.03), high APACHE II score (p = 0.04), and high SOFA score (p = 0.00). However, SOFA score was more effective than other predictive models as baseline and day 3 SOFA scores of more than 6 were highly predictive of poor outcome. L-Thyroxine treatment defaulters had more severe manifestations compared with de novo subjects. Outcome was not influenced by either aetiology or route of administration of L-thyroxine, and SOFA score was the best outcome predictor model.

Accurate age determinations of several nearby open clusters containing magnetic Ap stars

NASA Astrophysics Data System (ADS)

Silaj, J.; Landstreet, J. D.

2014-06-01

Context. To study the time evolution of magnetic fields, chemical abundance peculiarities, and other characteristics of magnetic Ap and Bp stars during their main sequence lives, a sample of these stars in open clusters has been obtained, as such stars can be assumed to have the same ages as the clusters to which they belong. However, in exploring age determinations in the literature, we find a large dispersion among different age determinations, even for bright, nearby clusters. Aims: Our aim is to obtain ages that are as accurate as possible for the seven nearby open clusters α Per, Coma Ber, IC 2602, NGC 2232, NGC 2451A, NGC 2516, and NGC 6475, each of which contains at least one magnetic Ap or Bp star. Simultaneously, we test the current calibrations of Te and luminosity for the Ap/Bp star members, and identify clearly blue stragglers in the clusters studied. Methods: We explore the possibility that isochrone fitting in the theoretical Hertzsprung-Russell diagram (i.e. log (L/L⊙) vs. log Te), rather than in the conventional colour-magnitude diagram, can provide more precise and accurate cluster ages, with well-defined uncertainties. Results: Well-defined ages are found for all the clusters studied. For the nearby clusters studied, the derived ages are not very sensitive to the small uncertainties in distance, reddening, membership, metallicity, or choice of isochrones. Our age determinations are all within the range of previously determined values, but the associated uncertainties are considerably smaller than the spread in recent age determinations from the literature. Furthermore, examination of proper motions and HR diagrams confirms that the Ap stars identified in these clusters are members, and that the presently accepted temperature scale and bolometric corrections for Ap stars are approximately correct. We show that in these theoretical HR diagrams blue stragglers are particularly easy to identify. Conclusions: Constructing the theoretical HR diagram of a nearby open cluster makes possible an accurate age determination, with well defined uncertainty. This diagnostic of a cluster also provides a useful tool for studying unusual stars such as Ap stars and blue stragglers. Table 3 is available in electronic form at http://www.aanda.org

Predictors of Stroke and Coma After Neurosurgery: An ACS-NSQIP Analysis.

PubMed

Larsen, Alexandra M G; Cote, David J; Karhade, Aditya V; Smith, Timothy R

2016-09-01

The American College of Surgeons National Surgical Quality Improvement Program database aims to reduce 30-day postoperative complications. Reduction of postoperative stroke and coma can decrease length and cost of hospitalization, improve patient functional status, and decrease morbidity and mortality. We performed a search of the American College of Surgeons National Surgical Quality Improvement Program database for all patients from 2006 to 2013 undergoing an operation with a surgeon whose primary specialty was neurologic surgery. Of 94,546 neurosurgical patients reported, there were 687 (0.73%) cases of postoperative stroke and coma. The annual rate of coma longer than 24 hours decreased from 0.90% in 2006 to 0.002% in 2013 (P < 0.001), and the annual rate of stroke decreased from 1.2% in 2006 to 0.5% in 2013 (P = 0.013). Multivariate analysis showed that inpatient status (P = 0.001; odds ratio [OR], 30.3), age (P = 0.005; OR, 1.012), history of diabetes (P = 0.017; OR, 1.515), ventilator dependence (P < 0.001; OR, 4.379), impaired sensorium (P < 0.001; OR, 2.314), history of coma longer than 24 hours (P < 0.001; OR, 2.655), hemiparesis (P = 0.022; OR, 1.492), cerebrovascular accident/stroke with neurologic deficit (P < 0.001; OR, 2.091), cerebrovascular accident/stroke without neurologic deficit (P = 0.001; OR, 2.44), and tumor involving central nervous system (P < 0.001; OR, 2.928) are significant risk factors for developing postneurosurgical stroke and coma. The rate of postneurosurgical stroke decreased from 1.2% in 2006 to 0.5% in 2013 and the rate of postneurosurgical coma greater than 24 hours decreased from 0.9% in 2006 to 0.002% in 2013. Ten risk factors for developing postneurosurgical stroke and coma were identified using multivariable analysis. These risk factors should be assessed preoperatively and incorporated into clinical decision making so that individuals who are at higher risk for the development of stroke and coma can be appropriately monitored during the postoperative period. Copyright © 2016 Elsevier Inc. All rights reserved.

The importance of early treatment with tranexamic acid in bleeding trauma patients: an exploratory analysis of the CRASH-2 randomised controlled trial.

PubMed

Roberts, Ian; Shakur, Haleema; Afolabi, Adefemi; Brohi, Karim; Coats, Tim; Dewan, Yashbir; Gando, Satoshi; Guyatt, Gordon; Hunt, B J; Morales, Carlos; Perel, Pablo; Prieto-Merino, David; Woolley, Tom

2011-03-26

The aim of the CRASH-2 trial was to assess the effects of early administration of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage. Tranexamic acid significantly reduced all-cause mortality. Because tranexamic acid is thought to exert its effect through inhibition of fibrinolysis, we undertook exploratory analyses of its effect on death due to bleeding. The CRASH-2 trial was undertaken in 274 hospitals in 40 countries. 20,211 adult trauma patients with, or at risk of, significant bleeding were randomly assigned within 8 h of injury to either tranexamic acid (loading dose 1 g over 10 min followed by infusion of 1 g over 8 h) or placebo. Patients were randomly assigned by selection of the lowest numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Both participants and study staff (site investigators and trial coordinating centre staff ) were masked to treatment allocation. We examined the effect of tranexamic acid on death due to bleeding according to time to treatment, severity of haemorrhage as assessed by systolic blood pressure, Glasgow coma score (GCS), and type of injury. All analyses were by intention to treat. The trial is registered as ISRCTN86750102, ClinicalTrials.gov NCT00375258, and South African Clinical Trial Register/Department of Health DOH-27-0607-1919. 10,096 patients were allocated to tranexamic acid and 10,115 to placebo, of whom 10,060 and 10,067, respectively, were analysed. 1063 deaths (35%) were due to bleeding. We recorded strong evidence that the effect of tranexamic acid on death due to bleeding varied according to the time from injury to treatment (test for interaction p<0.0001). Early treatment (≤1 h from injury) significantly reduced the risk of death due to bleeding (198/3747 [5.3%] events in tranexamic acid group vs 286/3704 [7.7%] in placebo group; relative risk [RR] 0.68, 95% CI 0.57-0.82; p<0.0001). Treatment given between 1 and 3 h also reduced the risk of death due to bleeding (147/3037 [4.8%] vs 184/2996 [6.1%]; RR 0.79, 0.64-0.97; p=0.03). Treatment given after 3 h seemed to increase the risk of death due to bleeding (144/3272 [4.4%] vs 103/3362 [3.1%]; RR 1.44, 1.12-1.84; p=0.004). We recorded no evidence that the effect of tranexamic acid on death due to bleeding varied by systolic blood pressure, Glasgow coma score, or type of injury. Tranexamic acid should be given as early as possible to bleeding trauma patients. For trauma patients admitted late after injury, tranexamic acid is less effective and could be harmful. UK NIHR Health Technology Assessment programme, Pfizer, BUPA Foundation, and J P Moulton Charitable Foundation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Uniform Contribution of Supernova Explosions to the Chemical Enrichment of Abell 3112 out to R{sub 200}

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

Ezer, Cemile; Ercan, E. Nihal; Bulbul, Esra

2017-02-10

The spatial distribution of the metals residing in the intra-cluster medium (ICM) of galaxy clusters records all the information on a cluster’s nucleosynthesis and chemical enrichment history. We present measurements from a total of 1.2 Ms Suzaku XIS and 72 ks Chandra observations of the cool-core galaxy cluster Abell 3112 out to its virial radius (∼1470 kpc). We find that the ratio of the observed supernova type Ia explosions to the total supernova explosions has a uniform distribution at a level of 12%–16% out to the cluster’s virial radius. The observed fraction of type Ia supernova explosions is in agreementmore » with the corresponding fraction found in our Galaxy and the chemical enrichment of our Galaxy. The non-varying supernova enrichment suggests that the ICM in cluster outskirts was enriched by metals at an early stage before the cluster itself was formed during a period of intense star formation activity. Additionally, we find that the 2D delayed detonation model CDDT produce significantly worse fits to the X-ray spectra compared to simple 1D W7 models. This is due to the relative overestimate of Si, and the underestimate of Mg in these models with respect to the measured abundances.« less

Pre-referral Rectal Artesunate Treatment by Community-Based Treatment Providers in Ghana, Guinea-Bissau, Tanzania, and Uganda (Study 18): A Cluster-Randomized Trial

PubMed Central

Warsame, Marian; Gyapong, Margaret; Mpeka, Betty; Rodrigues, Amabelia; Singlovic, Jan; Babiker, Abdel; Mworozi, Edison; Agyepong, Irene; Ansah, Evelyn; Azairwe, Robert; Biai, Sidu; Binka, Fred; Folb, Peter; Gyapong, John; Kimbute, Omari; Machinda, Zena; Kitua, Andrew; Lutalo, Tom; Majaha, Melkzedik; Mamadu, Jao; Mrango, Zakayo; Petzold, Max; Rujumba, Joseph; Ribeiro, Isabela; Gomes, Melba

2016-01-01

Background. If malaria patients who cannot be treated orally are several hours from facilities for injections, rectal artesunate prior to hospital referral can prevent death and disability. The goal is to reduce death from malaria by having rectal artesunate treatment available and used. How best to do this remains unknown. Methods. Villages remote from a health facility were randomized to different community-based treatment providers trained to provide rectal artesunate in Ghana, Guinea-Bissau, Tanzania, and Uganda. Prereferral rectal artesunate treatment was provided in 272 villages: 109 through community-based health workers (CHWs), 112 via trained mothers (MUMs), 25 via trained traditional healers (THs), and 26 through trained community-chosen personnel (COMs); episodes eligible for rectal artesunate were established through regular household surveys of febrile illnesses recording symptoms eligible for prereferral treatment. Differences in treatment coverage with rectal artesunate in children aged <5 years in MUM vs CHW (standard-of-care) villages were assessed using the odds ratio (OR); the predictive probability of treatment was derived from a logistic regression analysis, adjusting for heterogeneity between clusters (villages) using random effects. Results. Over 19 months, 54 013 children had 102 504 febrile episodes, of which 32% (31 817 episodes) had symptoms eligible for prereferral therapy; 14% (4460) children received treatment. Episodes with altered consciousness, coma, or convulsions constituted 36.6% of all episodes in treated children. The overall OR of treatment between MUM vs CHW villages, adjusting for country, was 1.84 (95% confidence interval [CI], 1.20–2.83; P = .005). Adjusting for heterogeneity, this translated into a 1.67 higher average probability of a child being treated in MUM vs CHW villages. Referral compliance was 81% and significantly higher with CHWs vs MUMs: 87% vs 82% (risk ratio [RR], 1.1 [95% CI, 1.0–1.1]; P < .0001). There were more deaths in the TH cluster than elsewhere (RR, 2.7 [95% CI, 1.4–5.6]; P = .0040). Conclusions. Prereferral episodes were almost one-third of all febrile episodes. More than one-third of patients treated had convulsions, altered consciousness, or coma. Mothers were effective in treating patients, and achieved higher coverage than other providers. Treatment access was low. Clinical Trials Registration. ISRCTN58046240. PMID:27941110

X-ray studies of coeval star samples. II. The Pleiades cluster as observed with the Einstein Observatory

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

Micela, G.; Sciortino, S.; Vaiana, G.S.

1990-01-01

Coronal X-ray emission of the Pleiades stars is investigated, and maximum likelihood, integral X-ray luminosity functions are computed for Pleiades members in selected color-index ranges. A detailed search is conducted for long-term variability in the X-ray emission of those stars observed more than once. An overall comparison of the survey results with those of previous surveys confirms the ubiquity of X-ray emission in the Pleiades cluster stars and its higher rate of emission with respect to older stars. It is found that the X-ray emission from dA and early dF stars cannot be proven to be dissimilar to that ofmore » Hyades and field stars of the same spectral type. The Pleiades cluster members show a real rise of the X-ray luminosity from dA stars to early dF stars. X-ray emission for the young, solarlike Pleiades stars is about two orders of magnitude more intense than for the nearby solarlike stars. 77 refs.« less

Yellow fever

MedlinePlus

... the heart, liver, and kidney. Bleeding disorders, seizures, coma, and delirium may also occur. Symptoms may include: ... heartbeats (arrhythmias) Bleeding (may progress to hemorrhage) Seizures Coma

Recovery of consciousness and an injured ascending reticular activating system in a patient who survived cardiac arrest: A case report.

PubMed

Jang, Sung Ho; Hyun, Yi Ji; Lee, Han Do

2016-06-01

We report on a patient who survived cardiac arrest and showed recovery of consciousness and an injured ARAS at the early stage of hypoxic-ischemic brain injury (HI- BI) for 3 weeks, which was demonstrated by diffusion tensor tractography (DTT).A 52-year-old male patient who had suffered cardiac arrest caused by acute coronary syndrome was resuscitated immediately by a layman and paramedics for ∼25 minutes. He was then transferred immediately to the emergency room of a local medical center. When starting rehabilitation at 2 weeks after onset, his consciousness was impaired, with a Glasgow Coma Scale (GCS) score of 8 and Coma Recovery Scale-Revised (GRS-R) score of 8. He underwent comprehensive rehabilitative therapy, including drugs for recovery of consciousness. He recovered well and rapidly so that his consciousness had recovered to full scores in terms of GCS:15 and GRS-R:23 at 5 weeks after onset.The left lower dorsal and right lower ventral ARAS had become thicker on 5-week DTT compared with 2-week DTT (Fig. 1B). Regarding the change of neural connectivity of the thalamic ILN, increased neural connectivity to the basal forebrain and prefrontal cortex was observed in both hemispheres on 5-week DTT compared with 2-week DTT.Recovery of an injured ARAS was demonstrated in a patient who survived cardiac arrest and his consciousness showed rapid and good recovery for 3 weeks at the early stage of HI-BI.

[Myxedema coma. A case reported].

PubMed

Rebollo-Gómez, Héctor

2010-01-01

Myxedema coma is a life-threatening condition; it is a complication of untreated hypothyroidism and an endocrine emergency. Most patients are elderly women with a previous history of long-standing hypothyroidism which presents during the winter. The myxedema coma has an insidious onset and it is very rare; its recognition can be quite difficult. Once suspected, treatment can be lifesaving and should be start promptly in anticipation of confirmation of the diagnosis by laboratory test. The mortality rate is high. I presented a case of an old woman with myxedema coma with an undiagnosed hypothyroidism, with altered mental status, normal temperature, pneumonia, hyponatremia and high level of creatine phosphokinase, who presented in the emergency room.

A CO2-rich coma model applied to the neutral coma of Comet West

NASA Technical Reports Server (NTRS)

Mitchell, G. F.; Swift, M. B.; Huntress, W. T.

1982-01-01

Models of the cometary coma in which the dominant volatile is CO2 have been constructed for a range of heliocentric distances. Model coma abundances of C2, C3, and CN are compared with the abundances observed in Comet West and are found to be in good agreement. Furthermore, the variation with heliocentric distance of C2, C3, and CN model abundances agree well with the observed variation in Comet West. The present work lends detailed support to a previous suggestion that a substance more volatile than water, such as CO2, controls the evaporation of the nucleus of Comet West. The implications for cometary formation are briefly discussed.

The dust distribution within the inner coma of comet P/Halley 1982i - Encounter by Giotto's impact detectors

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Evans, G. C.; Evans, S. T.; Alexander, W. M.; Burton, W. M.; Firth, J. G.; Bussoletti, E.; Grard, R. J. L.; Hanner, M. S.; Sekanina, Z.

1987-01-01

Analyses are presented of Giotto's Dust Impact Detection System experiment measurements of dust grains incident on the Giotto dust shield along its trajectory through the coma of comet P/Halley on March 13 and 14, 1986. Ground-based CCD imagery of the inner coma dust continuum at the time of the encounter are used to derive the area of grains intercepted by Giotto. Data obtained at large masses show clear evidence of a decrease in the mass distribution index at these masses within the coma; it is shown that such a value of the mass index can furnish sufficient mass for consistency with an observed deceleration.

A deep imaging survey of the Pleiades with ROSAT

NASA Technical Reports Server (NTRS)

Stauffer, J. R.; Caillault, J.-P.; Gagne, M.; Prosser, C. F.; Hartmann, L. W.

1994-01-01

We have obtained deep ROSAT images of three regions within the Pleiades open cluster. We have detected 317 X-ray sources in these ROSAT Position Sensitive Proportional Counter (PSPC) images, 171 of which we associate with certain or probable members of the Pleiades cluster. We detect nearly all Pleiades members with spectral types later than G0 and within 25 arcminutes of our three field centers where our sensitivity is highest. This has allowed us to derive for the first time the luminosity function for the G, K, amd M dwarfs of an open cluster without the need to use statistical techniques to account for the presence of upper limits in the data sample. Because of our high X-ray detection frequency down to the faint limit of the optical catalog, we suspect that some of our unidentified X-ray sources are previously unknown, very low-mass members of Pleiades. A large fraction of the Pleiades members detected with ROSAT have published rotational velocities. Plots of L(sub X)/L(sub Bol) versus spectroscopic rotational velocity show tightly correlated `saturation' type relations for stars with ((B - V)(sub 0)) greater than or equal to 0.60. For each of several color ranges, X-ray luminosities rise rapidly with increasing rotation rate until c sin i approximately equal to 15 km/sec, and then remains essentially flat for rotation rates up to at least v sin i approximately equal to 100 km/sec. The dispersion in rotation among low-mass stars in the Pleiades is by far the dominant contributor to the dispersion in L(sub X) at a given mass. Only about 35% of the B, A, and early F stars in the Pleiades are detected as X-ray sources in our survey. There is no correlation between X-ray flux and rotation for these stars. The X-ray luminosity function for the early-type Pleiades stars appears to be bimodal -- with only a few exceptions, we either detect these stars at fluxes in the range found for low-mass stars or we derive X-ray limits below the level found for most Pleiades dwarfs. The X-ray spectra for the early-type Pleiades stars detected by ROSAT are indistinguishable from the spectra of the low-mass Pleiades members. We believe that the simplest explanation for this behavior is that the early-type Pleiades stars are not themselves intrinsic X-ray sources and that the X-ray emission actually arises from low-mass companions to these stars.

Hydrogen halides at Comet 67P/Churyumov-Gerasimenko as detected by ROSINA-DFMS

NASA Astrophysics Data System (ADS)

Dhooghe, Frederik

2017-04-01

The Rosetta spacecraft has been studying the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) in-situ from the comet encounter in August 2014 up to end of mission in September 2016. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) contains a double focussing mass spectrometer (DFMS) with a mass range 13-140 u/e. It is optimized for high mass resolution and large dynamic range for the chemical and isotopic characterization of the volatiles in the coma. Since comets retained information about the physical and chemical conditions of the protoplanetary disk from which they formed, they may provide insights into the halogen chemistry in the early Solar System. We have studied the halogen-bearing compounds in the coma with DFMS on 67P/C-G's inbound journey during four periods, as the gas production increased towards perihelion and as the comet's subsolar latitude moved from the northern to the southern hemisphere: (A) when Rosetta was close to the comet, during 1-31/10/2014, at 3.0-3.3 AU, (B) during the close flybys on 14/2/2015 and on 28/3/2015 at 2.3 AU and 2.0 AU, (C) post-equinox between 10/5/2015 and 1/6/2015, at 1.5-1.7 AU, and (D) around perihelion between 9/7/2015 and 31/8/2015, at 1.24-1.31 AU. The main halogen-bearing compounds in the comet atmosphere were found to be the hydrogen halides HF (hydrogen fluoride), HCl (hydrogen chloride) and HBr (hydrogen bromide). HF and HCl could be observed during all four periods, while hydrogen bromide could, due to its low abundance, only be detected during period A, when Rosetta was close to the comet. An increase in the halogen-to-oxygen ratio as a function of distance was observed which suggests a distributed source for HF and HCl, probably through progressive release of these compounds from grains. This contribution will address the abundance and variability of the hydrogen halides in the coma as well as the cometary isotopic ratios for 37Cl/35Cl and 81Br/79Br.

Redshifts for 2410 Galaxies in the Century Survey Region

NASA Astrophysics Data System (ADS)

Wegner, Gary; Thorstensen, John R.; Kurtz, Michael J.; Brown, Warren R.; Fabricant, Daniel G.; Geller, Margaret J.; Huchra, John P.; Marzke, Ronald O.; Sakai, Shoko

2001-12-01

The Century Survey strip covers 102 deg2 within the limits 8h5<=α<=16h5, 29.0d<=δ<=30.0d, equinox B1950.0. The strip passes through the Corona Borealis supercluster and the outer region of the Coma cluster. Within the Century Survey region, we have measured 2410 redshifts that constitute four overlapping complete redshift surveys: (1) 1728 galaxies with Kron-Cousins Rph<=16.13 covering the entire strip, (2) 507 galaxies with Rph<=16.4 in right ascension range 8h32m<=α<=10 h45m, equinox B1950.0, (3) 1251 galaxies with absorption- and K-corrected RCCDc<=16.2 (where ``c'' indicates ``corrected'') covering the right ascension range 8h5<=α<=13h5, equinox B1950.0, and (4) 1255 galaxies with absorption- and K-corrected VCCDc<=16.7 also covering the right ascension range 8h5<=α<=13h5, equinox B1950.0. All these redshift samples are more than 98% complete to the specified magnitude limit. We derived samples 1 and 2 from scans of the POSS1 red (E) plates calibrated with CCD photometry. We derived samples 3 and 4 from deep V and R CCD images covering the entire region. We include coarse morphological types for all the galaxies in sample 1. The distribution of (V-R)CCD for each type corresponds appropriately with the classification. Work reported here is based partly on observations obtained at the Michigan-Dartmouth-MIT Observatory.

Latent profile and cluster analysis of infant temperament: Comparisons across person-centered approaches.

PubMed

Gartstein, Maria A; Prokasky, Amanda; Bell, Martha Ann; Calkins, Susan; Bridgett, David J; Braungart-Rieker, Julia; Leerkes, Esther; Cheatham, Carol L; Eiden, Rina D; Mize, Krystal D; Jones, Nancy Aaron; Mireault, Gina; Seamon, Erich

2017-10-01

There is renewed interest in person-centered approaches to understanding the structure of temperament. However, questions concerning temperament types are not frequently framed in a developmental context, especially during infancy. In addition, the most common person-centered techniques, cluster analysis (CA) and latent profile analysis (LPA), have not been compared with respect to derived temperament types. To address these gaps, we set out to identify temperament types for younger and older infants, comparing LPA and CA techniques. Multiple data sets (N = 1,356; 672 girls, 677 boys) with maternal ratings of infant temperament obtained using the Infant Behavior Questionnaire-Revised (Gartstein & Rothbart, 2003) were combined. All infants were between 3 and 12 months of age (M = 7.85; SD = 3.00). Due to rapid development in the first year of life, LPA and CA were performed separately for younger (n = 731; 3 to 8 months of age) and older (n = 625; 9 to 12 months of age) infants. Results supported 3-profile/cluster solutions as optimal for younger infants, and 5-profile/cluster solutions for the older subsample, indicating considerable differences between early/mid and late infancy. LPA and CA solutions produced relatively comparable types for younger and older infants. Results are discussed in the context of developmental changes unique to the end of the first year of life, which likely account for the present findings. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Thermal modeling of cometary nuclei

NASA Astrophysics Data System (ADS)

Weissman, P. R.; Kieffer, H. H.

1981-09-01

A model of the sublimation of volatile ices from a cometary nucleus is presented which includes the effects of (1) diurnal heating and cooling, (2) rotation period and pole orientation, (3) the thermal properties of the ice and subsurface layers, and (4) the contributions from coma opacity, scattering and thermal emission where the properties of the coma are derived from the integrated rate of volatile production by the nucleus. In applying the model to the case of the 1986 apparition of Halley's comet, it is found that the generation of a cometary dust coma increases the total energy reaching the Halley nucleus due to the greater geometrical cross-section of the coma as compared with the bare nucleus. The calculated coma opacity of Halley is about 0.2 at 1 AU from the sun and 1.2 at perihelion. Possible consequences of the results obtained for the generation of nongravitational forces, volatile production rates for comets and cometary lifetimes against sublimation are discussed.

Coma Morphology Due to an Extended Active Region and Implications for the Spin State of Comet Hale-Bopp

NASA Technical Reports Server (NTRS)

Samarasinha, Nalin H.

2000-01-01

We show that the circular character of continuum structures observed in the coma of comet Hale-Bopp around the perihelion passage is most likely due to a dust jet from a large extended active region on the surface. Coma morphology due to a wide jet is different from that due to a narrow jet. The latter shows foreshortening effects due to observing geometry, wider jet produces more circular features. This circularization effect provides a self-consistent explanation for the evolution of near-perihelion coma morphology. No changes in the direction of the rotational angular momentum vector are required during this period in contrast to the models of Schleicher et al. This circularization effect also enables us to produce near-circular coma features in the S-E quadrant during 1997 late February and therefore questions the basic premise on which Sekanina bases his morphological arguments for a gravitationally bound satellite nucleus.

A continued program of planetary study at the University of Texas McDonald Observatory

NASA Technical Reports Server (NTRS)

Smith, H. J.; Barker, E. S.; Cochran, W. D.; Trafton, L. M.

1986-01-01

The beginning of eclipses of the Pluto-Charon system was detected. The onset of coma formation of P/Halley at 5.4 au was detected and evidence of sublimation at 4.8 au when CN emission was detected. Extensive spatial maps of the gas in the comae of comets Halley and Giacobini-Zinner were obtained in fall 1985. Halley was time variable, and Giacobini-Zinner was depleted in C2 and C3 relative to CN. Comet Kopff was shown to have a pre-perihelion brightness maximum of its gas, consistent with mantle development if the comet is a high obliquity object. New Haser model scale lengths for CN, C3, and C2 were determined using results from the Faint Comet Survey. Spectra of 12 asteroids in unusual orbits showed no evidence of any comet-like emission features. In particular, 3200 Phaethon (1983 TB) has no gas or dust coma, in spite of the similarity of its orbit with the Geminid meteor stream. Data were analyzed on Saturn's H2 and CH4 bands for the recent southern summer using a Tomasko-Doose type of haze distribution. This haze model fits the data moderately well, giving a CH4 mixing ratio of (4.2 + or 0.4)x003. Simple functions were found to approximate the collision-induced rotation-translation thermal opacity of H2.