HI-deficient spiral galaxies in the Coma cluster and Abell 1367

International Nuclear Information System (INIS)

Sullivan, W.T. III; Johnson, P.E.

1978-01-01

A sample of 11 spiral galaxies in each of the clusters Abell 1367 and Coma (Abell 1656) was observed in the 21-cm H I line with the Arecibo 305-m radio telescope. Nine galaxies are detected in Al367 and three in Coma. Comparison of the quantity log M/sub H/L/sub pg/ for each galaxy with the mean value for its Hubble type from the standard samples of nearby spirals compiled by Balkowski and by Roberts indicates that the A1367 and Coma spirals have lower values of log M/sub H/L/sub pg/ than field spirals by a factor of at least 4, with the Coma values probably more extreme. It is argued that little of this effect (perhaps a factor approx. 1.5) can be attributed to the bias toward high luminosities in the sample, and thus that these spirals are deficient in H I by factors of at least 3 to 5 in comparison with the standard samples. For the present limited sample, several mechanisms seem adequate to account qualitatively for stripping of H I from the Coma cluster spirals, but the case of the A1367 spirals is puzzling. 2 figures

DEEP GALEX OBSERVATIONS OF THE COMA CLUSTER: SOURCE CATALOG AND GALAXY COUNTS

International Nuclear Information System (INIS)

Hammer, D.; Hornschemeier, A. E.; Miller, N.; Jenkins, L.; Mobasher, B.; Smith, R.; Arnouts, S.; Milliard, B.

2010-01-01

We present a source catalog from a deep 26 ks Galaxy Evolution Explorer (GALEX) observation of the Coma cluster in the far-UV (FUV; 1530 A) and near-UV (NUV; 2310 A) wavebands. The observed field is centered ∼0. 0 9 (1.6 Mpc) southwest of the Coma core in a well-studied region of the cluster known as 'Coma-3'. The entire field is located within the apparent virial radius of the Coma cluster, and has optical photometric coverage with Sloan Digital Sky Survey (SDSS) and deep spectroscopic coverage to r ∼ 21. We detect GALEX sources to NUV = 24.5 and FUV = 25.0, which corresponds to a star formation rate of ∼10 -3 M sun yr -1 for galaxies at the distance of Coma. We have assembled a catalog of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically confirmed Coma member galaxies that span a large range of galaxy types from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is ∼80% complete to NUV = 23 and FUV = 23.5. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g., object blends, source confusion, Eddington Bias) that influence the source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is free from source confusion over the UV magnitude range studied here; we estimate that the GALEX pipeline catalogs are

The radio halo and active galaxies in the Coma cluster

International Nuclear Information System (INIS)

Cordey, R.A.

1985-01-01

The Cambridge Low-Frequency Synthesis Telescope has been used to map the Coma cluster at 151 MHz. Two new extended sources are found, associated with the cluster galaxies NGC4839 and NGC4849. The central halo radio source is shown not to have a simple symmetrical structure but to be distorted, with separate centres of brightening near the radio galaxies NGC4874 and IC4040. The structure cannot be accounted for by cluster-wide acceleration processes but implies a close connection with current radio galaxies and, in particular, models requiring diffusion of electrons out of radio sources seem to be favoured. The other large source, near Coma A, is detected and higher resolution data at 1407 MHz are used to clarify its structure. (author)

Binary model for the coma cluster of galaxies

International Nuclear Information System (INIS)

Valtonen, M.J.; Byrd, G.G.

1979-01-01

We study the dynamics of galaxies in the Coma cluster and find that the cluster is probably dominated by a central binary of galaxies NGC 4874--NGC4889. We estimate their total mass to be about 3 x 10 14 M/sub sun/ by two independent methods (assuming in Hubble constant of 100 km s -1 Mpc -1 ). This binary is efficient in dynamically ejecting smaller galaxies, some of of which are seen in projection against the inner 3 0 radius of the cluster and which, if erroneously considered as bound members, cause a serious overestimate of the mass of the entire cluster. Taking account of the ejected galaxies, we estimate the total cluster mass to be 4--9 x 10 14 M/sub sun/, with a corresponding mass-to-light ratio for a typical galaxy in the range of 20--120 solar units. The origin of the secondary maximum observed in the radial surface density profile is studied. We consider it to be a remnant of a shell of galaxies which formed around the central binary. This shell expanded, then collapsed into the binary, and is now reexpanding. This is supported by the coincidence of the minimum in the cluster eccentricity and radical velocity dispersion at the same radial distance as the secondary maximum. Numerical simulations of a cluster model with a massive central binary and a spherical shell of test particles are performed, and they reproduce the observed shape, galaxy density, and radial velocity distributions in the Coma cluster fairly well. Consequences of extending the model to other clusters are discussed

H-alpha observations of spiral galaxies in Cancer, A1367, and Coma

International Nuclear Information System (INIS)

Kennicutt, R.C.; Bothun, G.D.; Schommer, R.A.

1984-01-01

We have used large aperture Hα photometry of 65 spiral galaxies in the Cancer, Coma, and Abell 1367 clusters to compare the ionized-gas contents and star-formation rates in cluster and field spirals. Overall, we do not observe any significant deficiency of Hα emission in the cluster members. Emission strength correlates strongly with integrated galaxy colors, but only weakly with H I content. All three clusters contain several galaxies with unusually strong Hα emission, including several H I-poor objects in Coma and A1367. Thus, spirals which appear ''anemic'' in their morphology or exhibit weak Hα emission are not necessarily H I poor; conversely, H I poor spirals can show strong Hα emission, indicating relatively high current star-formation rates. Gas depletion time scales for some objects in the core of Coma are significantly shorter than the field, indicating rapid stellar and gaseous evolution

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

International Nuclear Information System (INIS)

Chiboucas, Kristin; Tully, R. Brent; Marzke, Ronald O.; Trentham, Neil; Ferguson, Henry C.; Hammer, Derek; Carter, David; Khosroshahi, Habib

2010-01-01

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. From 93 spectra, 51 dwarf galaxy members and 20 background galaxies are identified. Our morphological membership estimation success rate is ∼100% for objects expected to be members and better than ∼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 ∼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

FAST MOTIONS OF GALAXIES IN THE COMA I CLOUD: A CASE OF DARK ATTRACTOR?

International Nuclear Information System (INIS)

Karachentsev, Igor D.; Nasonova, Olga G.; Courtois, Helene M.

2011-01-01

We note that nearby galaxies having high negative peculiar velocities are distributed over the sky very inhomogeneously. A part of this anisotropy is caused by the 'Local Velocity Anomaly', i.e., by the bulk motion of nearby galaxies away from the Local Void. However, half of the fast-flying objects reside within a small region known as the Coma I cloud. According to Makarov and Karachentsev, this complex contains 8 groups, 5 triplets, 10 pairs, and 83 single galaxies with a total mass of 4.7 × 10 13 M ☉ . We use 122 galaxies in the Coma I region with known distances and radial velocities V LG –1 to draw the Hubble relation for them. The Hubble diagram shows a Z-shaped effect of infall with an amplitude of +200 km s –1 on the nearby side and –700 km s –1 on the back side. This phenomenon can be understood as the galaxy infall toward a dark attractor with a mass of ∼2 × 10 14 M ☉ situated at a distance of 15 Mpc from us. The existence of a large void between the Coma and Virgo clusters also probably affects the Hubble flow around the Coma I.

Dark energy and the structure of the Coma cluster of galaxies

Science.gov (United States)

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 (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.

Deep Galex Observations of the Coma Cluster: Source Catalog and Galaxy Counts

Science.gov (United States)

Hammer, D.; Hornschemeier, A. E.; Mobasher, B.; Miller, N.; Smith, R.; Arnouts, S.; Milliard, B.; Jenkins, L.

2010-01-01

We present a source catalog from deep 26 ks GALEX observations of the Coma cluster in the far-UV (FUV; 1530 Angstroms) and near-UV (NUV; 2310 Angstroms) wavebands. The observed field is centered 0.9 deg. (1.6 Mpc) south-west of the Coma core, and has full optical photometric coverage by SDSS and spectroscopic coverage to r-21. The catalog consists of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically-confirmed Coma member galaxies that range from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is 80% complete to NUV=23 and FUV=23.5, and has a limiting depth at NUV=24.5 and FUV=25.0 which corresponds to a star formation rate of 10(exp -3) solar mass yr(sup -1) at the distance of Coma. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as a position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g. object blends, source confusion, Eddington Bias) that influence source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is also free from source confusion over the UV magnitude range studied here: conversely, we estimate that the GALEX pipeline catalogs are confusion limited at NUV approximately 23 and FUV approximately 24. We have measured the total UV galaxy counts using our catalog and report a 50% excess of counts across FUV=22-23.5 and NUV=21.5-23 relative to previous GALEX

The HST/ACS Coma Cluster Survey : VI. Colour gradients in giant and dwarf early-type galaxies

NARCIS (Netherlands)

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

Using deep, high-spatial-resolution imaging from the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey, we determine colour profiles of early-type galaxies in the Coma cluster. From 176 galaxies brighter than M-F814W(AB) = -15 mag that are either

A DOZEN NEW GALAXIES CAUGHT IN THE ACT: GAS STRIPPING AND EXTENDED EMISSION LINE REGIONS IN THE COMA CLUSTER

International Nuclear Information System (INIS)

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

2010-01-01

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.

Dynamics of rich clusters of galaxies. I. The Coma cluster

International Nuclear Information System (INIS)

Kent, S.M.; Gunn, J.E.

1982-01-01

The structure and dynamics of the Coma cluster are analyzed using self-consistent equilibrium dynamical models. Observational material for Coma is culled from a variety of sources. Projected surface, density, and velocity-dispersion profiles are derived extending out to a radius of 3 0 from the cluster center, which are essentially free from field contamination. Segregation of galaxies by luminosity and morphology are discussed and a quantitative estimate of the latter is made. The method of constructing self-consistent dynamical models is discussed. Four different forms of the distribution function are analyzed allowing for different possible dependences of f on energy and angular momentum. Properties of typical models that might resemble actual clusters are presented, and the importance of having velocity-dispersion information is empha sized. The effect of a central massive object such as a cD galaxy on the core structure is illustrated. A comparison of these models with Coma reveals that only models with a distribution function in which the ratio of tangential to radial velocity dispersions is everywhere constant give acceptable fits. In particular, it is possible to rule out models that have isotropic motions in the core and predominantly radial motions in the halo. For H 0 = 50, the best-fitting models give a total projected mass inside 3 0 of 2.9 x 10 15 M/sub sun/ , a core radius of 340--400 kpc (8.5'--10'), an upper limit to any central massive object of approx.10 13 M/sub sun/ , and a mass-to-blue-light ratio of M/L = 181. From cosmological considerations the cluster ''edge'' is determined to lie at rapprox.5 0 --6 0 . The possible distribution of ''dark matter'' in Coma is discussed and it is argued that this distribution cannot be significantly different from that of the galaxies. The dynamics of morphological segregation are examined quantitatively, and are explained at least qualitatively

GLOBULAR CLUSTERS AND SPUR CLUSTERS IN NGC 4921, THE BRIGHTEST SPIRAL GALAXY IN THE COMA CLUSTER

International Nuclear Information System (INIS)

Lee, Myung Gyoon; Jang, In Sung

2016-01-01

We resolve a significant fraction of globular clusters (GCs) in NGC 4921, the brightest spiral galaxy in the Coma cluster. We also find a number of extended bright star clusters (star complexes) in the spur region of the arms. The latter are much brighter and bluer than those in the normal star-forming region, being as massive as 3 × 10 5 M ⊙ . The color distribution of the GCs in this galaxy is found to be bimodal. The turnover magnitudes of the luminosity functions of the blue (metal-poor) GCs (0.70 < (V − I) ≤ 1.05) in the halo are estimated V(max) = 27.11 ± 0.09 mag and I(max) = 26.21 ± 0.11 mag. We obtain similar values for NGC 4923, a companion S0 galaxy, and two Coma cD galaxies (NGC 4874 and NGC 4889). The mean value for the turnover magnitudes of these four galaxies is I(max) = 26.25 ± 0.03 mag. Adopting M I (max) = −8.56 ± 0.09 mag for the metal-poor GCs, we determine the mean distance to the four Coma galaxies to be 91 ± 4 Mpc. Combining this with the Coma radial velocity, we derive a value of the Hubble constant, H 0  = 77.9 ± 3.6 km s −1 Mpc −1 . We estimate the GC specific frequency of NGC 4921 to be S N  = 1.29 ± 0.25, close to the values for early-type galaxies. This indicates that NGC 4921 is in the transition phase to S0s

GLOBULAR CLUSTERS AND SPUR CLUSTERS IN NGC 4921, THE BRIGHTEST SPIRAL GALAXY IN THE COMA CLUSTER

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Gyoon; Jang, In Sung, E-mail: mglee@astro.snu.ac.kr, E-mail: isjang@astro.snu.ac.kr [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

2016-03-01

We resolve a significant fraction of globular clusters (GCs) in NGC 4921, the brightest spiral galaxy in the Coma cluster. We also find a number of extended bright star clusters (star complexes) in the spur region of the arms. The latter are much brighter and bluer than those in the normal star-forming region, being as massive as 3 × 10{sup 5} M{sub ⊙}. The color distribution of the GCs in this galaxy is found to be bimodal. The turnover magnitudes of the luminosity functions of the blue (metal-poor) GCs (0.70 < (V − I) ≤ 1.05) in the halo are estimated V(max) = 27.11 ± 0.09 mag and I(max) = 26.21 ± 0.11 mag. We obtain similar values for NGC 4923, a companion S0 galaxy, and two Coma cD galaxies (NGC 4874 and NGC 4889). The mean value for the turnover magnitudes of these four galaxies is I(max) = 26.25 ± 0.03 mag. Adopting M{sub I} (max) = −8.56 ± 0.09 mag for the metal-poor GCs, we determine the mean distance to the four Coma galaxies to be 91 ± 4 Mpc. Combining this with the Coma radial velocity, we derive a value of the Hubble constant, H{sub 0} = 77.9 ± 3.6 km s{sup −1} Mpc{sup −1}. We estimate the GC specific frequency of NGC 4921 to be S{sub N} = 1.29 ± 0.25, close to the values for early-type galaxies. This indicates that NGC 4921 is in the transition phase to S0s.

Origins of ultra-diffuse galaxies in the Coma cluster - II. Constraints from their stellar populations

Science.gov (United States)

Ferré-Mateu, Anna; Alabi, Adebusola; Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean; Pandya, Viraj; Martín-Navarro, Ignacio; Bellstedt, Sabine; Wasserman, Asher; Stone, Maria B.; Okabe, Nobuhiro

2018-06-01

In this second paper of the series we study, with new Keck/DEIMOS spectra, the stellar populations of seven spectroscopically confirmed ultra-diffuse galaxies (UDGs) in the Coma cluster. We find intermediate to old ages (˜ 7 Gyr), low metallicities ([Z/H]˜ - 0.7 dex) and mostly super-solar abundance patterns ([Mg/Fe] ˜ 0.13 dex). These properties are similar to those of low-luminosity (dwarf) galaxies inhabiting the same area in the cluster and are mostly consistent with being the continuity of the stellar mass scaling relations of more massive galaxies. These UDGs' star formation histories imply a relatively recent infall into the Coma cluster, consistent with the theoretical predictions for a dwarf-like origin. However, considering the scatter in the resulting properties and including other UDGs in Coma, together with the results from the velocity phase-space study of the Paper I in this series, a mixed-bag of origins is needed to explain the nature of all UDGs. Our results thus reinforce a scenario in which many UDGs are field dwarfs that become quenched through their later infall onto cluster environments, whereas some UDGs could be be genuine primordial galaxies that failed to develop due to an early quenching phase. The unknown proportion of dwarf-like to primordial-like UDGs leaves the enigma of the nature of UDGs still open.

THE HST/ACS COMA CLUSTER SURVEY. IV. INTERGALACTIC GLOBULAR CLUSTERS AND THE MASSIVE GLOBULAR CLUSTER SYSTEM AT THE CORE OF THE COMA GALAXY CLUSTER

International Nuclear Information System (INIS)

Peng, Eric W.; Ferguson, Henry C.; Goudfrooij, Paul; Hammer, Derek; Lucey, John R.; Marzke, Ronald O.; Puzia, Thomas H.; Carter, David; Balcells, Marc; Bridges, Terry; Chiboucas, Kristin; Del Burgo, Carlos; Graham, Alister W.; Guzman, Rafael; Hudson, Michael J.; Matkovic, Ana

2011-01-01

Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these populations is difficult, but important for understanding the assembly of the most massive galaxies. The Coma cluster of galaxies is one of the nearest truly massive galaxy clusters and is host to a correspondingly large system of globular clusters (GCs). We use imaging from the HST/ACS Coma Cluster Survey to present the first definitive detection of a large population of intracluster GCs (IGCs) that fills the Coma cluster core and is not associated with individual galaxies. The GC surface density profile around the central massive elliptical galaxy, NGC 4874, is dominated at large radii by a population of IGCs that extend to the limit of our data (R +4000 -5000 (systematic) IGCs out to this radius, and that they make up ∼70% of the central GC system, making this the largest GC system in the nearby universe. Even including the GC systems of other cluster galaxies, the IGCs still make up ∼30%-45% of the GCs in the cluster core. Observational limits from previous studies of the intracluster light (ICL) suggest that the IGC population has a high specific frequency. If the IGC population has a specific frequency similar to high-S N dwarf galaxies, then the ICL has a mean surface brightness of μ V ∼ 27 mag arcsec -2 and a total stellar mass of roughly 10 12 M sun within the cluster core. The ICL makes up approximately half of the stellar luminosity and one-third of the stellar mass of the central (NGC 4874+ICL) system. The color distribution of the IGC population is bimodal, with blue, metal-poor GCs outnumbering red, metal-rich GCs by a ratio of 4:1. The inner GCs associated with NGC 4874 also have a bimodal distribution in color, but with a redder metal-poor population. The fraction of red IGCs (20%), and the red color of those GCs, implies that IGCs can originate from the halos of relatively massive, L* galaxies, and not solely from the disruption of

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

Science.gov (United States)

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.

Coma cluster ultradiffuse galaxies are not standard radio galaxies

Science.gov (United States)

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.

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

Science.gov (United States)

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 =0.8 and median axis ratio =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%.

The Enigmatic (Almost) Dark Galaxy Coma P: The Atomic Interstellar Medium

Science.gov (United States)

Ball, Catherine; Cannon, John M.; Leisman, Lukas; Adams, Elizabeth A. K.; Haynes, Martha P.; Józsa, Gyula I. G.; McQuinn, Kristen B. W.; Salzer, John J.; Brunker, Samantha; Giovanelli, Riccardo; Hallenbeck, Gregory; Janesh, William; Janowiecki, Steven; Jones, Michael G.; Rhode, Katherine L.

2018-02-01

We present new high-resolution H I spectral line imaging of Coma P, the brightest H I source in the system HI 1232+20. This galaxy with extremely low surface brightness was first identified in the ALFALFA survey as an “(Almost) Dark” object: a clearly extragalactic H I source with no obvious optical counterpart in existing optical survey data (although faint ultraviolet emission was detected in archival GALEX imaging). Using a combination of data from the Westerbork Synthesis Radio Telescope and the Karl G. Jansky Very Large Array, we investigate the H I morphology and kinematics at a variety of physical scales. The H I morphology is irregular, reaching only moderate maxima in mass surface density (peak {σ }{{H}{{I}}}∼ 10 {M}ȯ pc‑2). Gas of lower surface brightness extends to large radial distances, with the H I diameter measured at 4.0 ± 0.2 kpc inside the 1 {M}ȯ pc‑2 level. We quantify the relationships between mass surface density of H I gas and star formation on timescales of ∼100–200 Myr as traced by GALEX far-ultraviolet emission. While Coma P has regions of dense H I gas reaching the {N}{{H}{{I}}}={10}21 cm‑2 level typically associated with ongoing star formation, it lacks massive star formation as traced by Hα emission. The H I kinematics are extremely complex: a simple model of a rotating disk cannot describe the H I gas in Coma P. Using spatially resolved position–velocity analysis we identify two nearly perpendicular axes of projected rotation that we interpret as either the collision of two H I disks or a significant infall event. Similarly, three-dimensional modeling of the H I dynamics provides a best fit with two H I components. Coma P is just consistent (within 3σ) with the known {M}{{H}{{I}}}{--}{D}{{H}{{I}}} scaling relation. It is either too large for its H I mass, has too low an H I mass for its H I size, or the two H I components artificially extend its H I size. Coma P lies within the empirical scatter at the faint end

Infrared emission from dust in the Coma cluster of galaxies

International Nuclear Information System (INIS)

Dwek, E.; Rephaeli, Y.; Mather, J.C.

1990-01-01

Detailed calculations of the infrared emission from collisionally heated dust in the Coma cluster are presented. The proposed model includes continuous dust injection from galaxies, grain destruction by sputtering, and transient grain heating by the hot plasma. The computed infrared fluxes are in agreement with the upper limits obtained from the IRAS. The calculations, and constraints implied by the IRAS observations, suggest that the intracluster dust in the central region of the cluster must be significantly depleted compared to interstellar abundances. The observed visual extinction can therefore not be attributed to the presence of dust in that region. Extinction due to cluster galaxies or their haloes is ruled out as well. The only alternative explanation is that the extinction is caused by dust at great distances from the cluster center. 30 refs

CHEMICAL SIGNATURES OF THE FIRST GALAXIES: CRITERIA FOR ONE-SHOT ENRICHMENT

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Frebel, Anna; Bromm, Volker

2012-01-01

We utilize metal-poor stars in the local, ultra-faint dwarf galaxies (UFDs; L tot ≤ 10 5 L ☉ ) to empirically constrain the formation process of the first galaxies. Since UFDs have much simpler star formation histories than the halo of the Milky Way, their stellar populations should preserve the fossil record of the first supernova (SN) explosions in their long-lived, low-mass stars. Guided by recent hydrodynamical simulations of first galaxy formation, we develop a set of stellar abundance signatures that characterize the nucleosynthetic history of such an early system if it was observed in the present-day universe. Specifically, we argue that the first galaxies are the product of chemical 'one-shot' events, where only one (long-lived) stellar generation forms after the first, Population III, SN explosions. Our abundance criteria thus constrain the strength of negative feedback effects inside the first galaxies. We compare the stellar content of UFDs with these one-shot criteria. Several systems (Ursa Major II, and also Coma Berenices, Bootes I, Leo IV, Segue 1) largely fulfill the requirements, indicating that their high-redshift predecessors did experience strong feedback effects that shut off star formation. We term the study of the entire stellar population of a dwarf galaxy for the purpose of inferring details about the nature and origin of the first galaxies 'dwarf galaxy archaeology'. This will provide clues to the connection of the first galaxies, the surviving, metal-poor dwarf galaxies, and the building blocks of the Milky Way.

A NOVEL APPROACH TO CONSTRAIN THE MASS RATIO OF MINOR MERGERS IN ELLIPTICAL GALAXIES: APPLICATION TO NGC 4889, THE BRIGHTEST CLUSTER GALAXY IN COMA

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Gu Meng; Huang Song [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Ho, Luis C. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Peng, Chien Y. [Giant Magellan Telescope Organization, 251 South Lake Avenue, Suite 300, Pasadena, CA 91101 (United States)

2013-08-10

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 (M{sub I} Almost-Equal-To -18.7 mag) disk (S0 or spiral) galaxy with a luminosity (mass) ratio of {approx}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.

A NOVEL APPROACH TO CONSTRAIN THE MASS RATIO OF MINOR MERGERS IN ELLIPTICAL GALAXIES: APPLICATION TO NGC 4889, THE BRIGHTEST CLUSTER GALAXY IN COMA

International Nuclear Information System (INIS)

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

2013-01-01

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 (M I ≈ –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

Is the Coma cluster binary dominated?

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The, L.S.; White, S.D.M.

1990-01-01

It is investigated whether the model of an expanding cluster dominated by a massive binary galaxy, first suggested by Valtonen and Byrd (1979), is consistent with optical data on the surface density and velocity dispersion of the Coma cluster. The evolution of this model is simulated for a wide variety of initial conditions. It is found that galaxy counts in the model can be made to agree with observation, but that the observed velocity dispersion profile cannot be reproduced. A number of other arguments suggest that the central galaxies in Coma cannot be as massive as required by the model. This model is not a viable representation of the Coma cluster. 25 refs

ULTRA-COMPACT DWARFS IN THE COMA CLUSTER

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Chiboucas, Kristin; Tully, R. Brent; Marzke, R. O.; Phillipps, S.; Price, J.; Peng, Eric W.; Trentham, Neil; Carter, David; Hammer, Derek

2011-01-01

We have undertaken a spectroscopic search for ultra-compact dwarf galaxies (UCDs) in the dense core of the dynamically evolved, massive Coma cluster as part of the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey. UCD candidates were initially chosen based on color, magnitude, degree of resolution within the ACS images, and the known properties of Fornax and Virgo UCDs. Follow-up spectroscopy with Keck/Low-Resolution Imaging Spectrometer confirmed 27 candidates as members of the Coma cluster, a success rate >60% for targeted objects brighter than M R = -12. Another 14 candidates may also prove to be Coma members, but low signal-to-noise spectra prevent definitive conclusions. An investigation of the properties and distribution of the Coma UCDs finds these objects to be very similar to UCDs discovered in other environments. The Coma UCDs tend to be clustered around giant galaxies in the cluster core and have colors/metallicity that correlate with the host galaxy. With properties and a distribution similar to that of the Coma cluster globular cluster population, we find strong support for a star cluster origin for the majority of the Coma UCDs. However, a few UCDs appear to have stellar population or structural properties which differentiate them from the old star cluster populations found in the Coma cluster, perhaps indicating that UCDs may form through multiple formation channels.

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

Science.gov (United States)

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.

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

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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.

Radio observations of the peripheral region of the Coma cluster near Coma A

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Giovannini, G.

1986-01-01

VLA and WSRT observations are reported for the extended radio source 1253+275 on the periphery of the Coma cluster and for two active Coma radio galaxies within 20 arcmin of 1253+275. The data are presented in contour maps and characterized in detail. Source 1253+275 is shown to be a relic radio galaxy with physical conditions similar to those seen in the external regions (30-50 kpc from the cores) of the two active sources (NGC 4789 and NGC 4827). It is suggested that these regions survived for long periods (400 Myr) after the last acceleration of the radiating electrons because transverse expansion was inhibited by the local intergalactic medium, which has a density comparable to that in other rich clusters of galaxies. 7 references

The outskirts of the Coma cluster

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Gavazzi, Giuseppe

Evolved Coma-like clusters of galaxies are constituted of relaxed cores composed of ''old'' early-type galaxies, embedded in large-scale structures, mostly constituted of unevolved (late-type) systems. According to the hierarchical theory of cluster formation the central regions are being fed with unevolved, low-mass systems infalling from the surroundings that are gradually transformed into elliptical/S0 galaxies by tidal galaxy-galaxy and galaxy-cluster interactions, taking place at some boundary distance. The Coma cluster, the most studied of all local clusters, provides us with the ideal test-bed for such an evolutionary study because of the completeness of the photometric and kinematic information already at hands. The field of view of the planned GALEX observations is not big enough to include the boundary interface where most transformations processes are expected to take place, including the truncation of the current star formation. We propose to complete the outskirt of Coma with an additional corona of 11 GALEX imaging fields of 1500 sec exposure each, matching the deepness (UV_{AB}=23.5 mag) of the fields observed in guarantee time. Given the priority of the target, we also propose one optional Central pointing that includes one bright star marginally exceeding the detector brightness limit.

KINEMATICS AND EXCITATION OF THE RAM PRESSURE STRIPPED IONIZED GAS FILAMENTS IN THE COMA CLUSTER OF GALAXIES

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Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yagi, Masafumi; Komiyama, Yutaka; Kashikawa, Nobunari [Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Furusawa, Hisanori [Astronomical Data Center, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Hattori, Takashi [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' Ohoku Place, Hilo, HI 96720 (United States); Okamura, Sadanori, E-mail: yoshidam@hiroshima-u.ac.jp [Department of Astronomy, University of Tokyo, Tokyo 113-0033 (Japan)

2012-04-10

We present the results of deep imaging and spectroscopic observations of very extended ionized gas (EIG) around four member galaxies of the Coma Cluster of galaxies: RB 199, IC 4040, GMP 2923, and GMP 3071. The EIGs were serendipitously found in an H{alpha} narrowband imaging survey of the central region of the Coma Cluster. The relative radial velocities of the EIGs with respect to the systemic velocities of the parent galaxies from which they emanate increase almost monotonically with the distance from the nucleus of the respective galaxies, reaching {approx} - 400 to - 800 km s{sup -1} at around 40-80 kpc from the galaxies. The one-sided morphologies and the velocity fields of the EIGs are consistent with the predictions of numerical simulations of ram pressure stripping. We found a very low velocity filament (v{sub rel} {approx} -1300 km s{sup -1}) at the southeastern edge of the disk of IC 4040. Some bright compact knots in the EIGs of RB 199 and IC 4040 exhibit blue continuum and strong H{alpha} emission. The equivalent widths of the H{alpha} emission exceed 200 A and are greater than 1000 Angstrom-Sign for some knots. The emission-line intensity ratios of the knots are basically consistent with those of sub-solar abundance H II regions. These facts indicate that intensive star formation occurs in the knots. Some filaments, including the low-velocity filament of the IC 4040 EIG, exhibit shock-like emission-line spectra, suggesting that shock heating plays an important role in ionization and excitation of the EIGs.

Deep UV Luminosity Functions at the Infall Region of the Coma Cluster

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Hammer, D. M.; Hornschemeier, A. E.; Salim, S.; Smith, R.; Jenkins, L.; Mobasher, B.; Miller, N.; Ferguson, H.

2011-01-01

We have used deep GALEX observations at the infall region of the Coma cluster to measure the faintest UV luminosity functions (LFs) presented for a rich galaxy cluster thus far. The Coma UV LFs are measured to M(sub uv) = -10.5 in the GALEX FUV and NUV bands, or 3.5 mag fainter than previous studies, and reach the dwarf early-type galaxy population in Coma for the first time. The Schechter faint-end slopes (alpha approximately equal to -1.39 in both GALEX bands) are shallower than reported in previous Coma UV LF studies owing to a flatter LF at faint magnitudes. A Gaussian-plus-Schechter model provides a slightly better parametrization of the UV LFs resulting in a faint-end slope of alpha approximately equal to -1.15 in both GALEX bands. The two-component model gives faint-end slopes shallower than alpha = -1 (a turnover) for the LFs constructed separately for passive and star forming galaxies. The UV LFs for star forming galaxies show a turnover at M(sub UV) approximately equal to -14 owing to a deficit of dwarf star forming galaxies in Coma with stellar masses below M(sub *) = 10(sup 8) solar mass. A similar turnover is identified in recent UV LFs measured for the Virgo cluster suggesting this may be a common feature of local galaxy clusters, whereas the field UV LFs continue to rise at faint magnitudes. We did not identify an excess of passive galaxies as would be expected if the missing dwarf star forming galaxies were quenched inside the cluster. In fact, the LFs for both dwarf passive and star forming galaxies show the same turnover at faint magnitudes. We discuss the possible origin of the missing dwarf star forming galaxies in Coma and their expected properties based on comparisons to local field galaxies.

DEEP ULTRAVIOLET LUMINOSITY FUNCTIONS AT THE INFALL REGION OF THE COMA CLUSTER

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Hammer, D. M.; Hornschemeier, A. E.; Jenkins, L.; Salim, S.; Smith, R.; Mobasher, B.; Miller, N.; Ferguson, H.

2012-01-01

We have used deep GALEX observations at the infall region of the Coma cluster to measure the faintest ultraviolet (UV) luminosity functions (LFs) presented for a rich galaxy cluster thus far. The Coma UV LFs are measured to M UV = –10.5 in the GALEX FUV and NUV bands, or 3.5 mag fainter than previous studies, and reach the dwarf early-type galaxy population in Coma for the first time. The Schechter faint-end slopes (α ≈ –1.39 in both GALEX bands) are shallower than reported in previous Coma UV LF studies owing to a flatter LF at faint magnitudes. A Gaussian-plus-Schechter model provides a slightly better parameterization of the UV LFs resulting in a faint-end slope of α ≈ –1.15 in both GALEX bands. The two-component model gives faint-end slopes shallower than α = –1 (a turnover) for the LFs constructed separately for passive and star-forming galaxies. The UV LFs for star-forming galaxies show a turnover at M UV ≈ –14 owing to a deficit of dwarf star-forming galaxies in Coma with stellar masses below M * = 10 8 M ☉ . A similar turnover is identified in recent UV LFs measured for the Virgo cluster suggesting this may be a common feature of local galaxy clusters, whereas the field UV LFs continue to rise at faint magnitudes. We did not identify an excess of passive galaxies as would be expected if the missing dwarf star-forming galaxies were quenched inside the cluster. In fact, the LFs for both dwarf passive and star-forming galaxies show the same turnover at faint magnitudes. We discuss the possible origin of the missing dwarf star-forming galaxies in Coma and their expected properties based on comparisons to local field galaxies.

Soft X-ray structure of the Coma cluster of galaxies

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Gorenstein, P.; Fabricant, D.; Topka, K.; Harnden, F.R. Jr.

1979-01-01

An X-ray image of the Coma cluster of galaxies was obtained in the 0.15--2.0 keV band with an imaging telescope. In contrast to the Virgo and Perseus clusters, which were observed previously with the same instrument, there is no indication of a strong contribution from an individual galaxy. However, there is granularity within the central region of the X-ray source that is suggestive of the galaxy distribution. For the 0.15--0.28 keV band only, the flux is much larger in the region north of the cluster center as compared to the south. We interpret this as a Galactic feature accidentally superposed upon the cluster.There is a marginal indication of ellipticity in the region between 10' and 25' from the center. The major axis is approximately along the E-W direction and is 1.2 +- 0.1 times larger than the minor axis. This is consistent with the distribution of galaxies.Assuming radial symmetry, three models containing a free parameter were fitted to the radial distribution of surface brightness: isothermal hydrostatic, adiabatic hydrostatic, and the isothermal sphere. All three fit the data with an acceptable value for the chi 2 . Of the three, the isothermal hydrostatic model is unique in its prediction of an extended halo beyond the range of measurements. For this model β=0.49, meaning that gas density falls off with radius approximately as the square root of the galaxy density. This value of of β is in agreement with the number computed from optical data and the X-ray temperature. Comparison of our 0.5--2.0 keV intensity with an extrapolation of a higher energy measurement obtained with a broader field of view detector aboard OSO 8 provides tentative evidence that the isothermal hydrostatic model is the most appropriate of the three models considered

Discovery of intergalactic radio emission in the Coma-A1367 supercluster

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Kim, K.T.; Kronberg, P.P.; Venturi, T.

1989-01-01

The Coma cluster is a rich cluster of galaxies nested in an even larger super cluster of galaxies. The plane of the supercluster seems to be defined by the Coma cluster itself and another galaxy cluster, Abell 1367, which lies ∼ 40 Mpc farther west. The largest structures known are the giant voids and superclusters which are as large as 70h 75 -1 Mpc (refs 3-5). The Coma cluster of galaxies seems to be located on the rim of a giant void in the three-dimensional distribution of galaxies. Here we describe the detection of faint, supercluster-scale radio emission at 326 MHz that extends between the Coma cluster of galaxies and the Abell 1367 cluster and which is apparently not associated with any individual galaxy system in the complex. The radiation's synchrotron origin implies the existence of a large-scale intercluster magnetic field with an estimated strength of 0.3-0.6 μG, which is remarkably strong. The synchrotron-emitting relativistic electrons cannot be older than a few times 10 8 yr, but we speculate that the magnetic field is the fossil of a pre-galactic primaeval field, which was amplified in the course of the formation of intergalactic voids and superclusters. (author)

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

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

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

Science.gov (United States)

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).

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

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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.

Observation of the Coma cluster of galaxies with ROSAT during the all-sky survey

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Briel, U. G.; Henry, J. P.; Boehringer, H.

1992-01-01

The Coma cluster of galaxies was observed with the position sensitive proportional counter (PSPC) during the ROSAT all sky survey. We find evidence for substructure in this cluster. Diffuse X-ray emission is detected from the regions of the NGC 4839 and 4911 subgroups at 6 percent and 1 percent of the total cluster emission respectively. There may be emission associated with the NGC 4874 and 4889 subgroups as well. The NGC 4839 group appears to be in the process of merging with the cluster. These X-ray data show that at least some of the groups previously found in projection are in fact physical objects possessing potential wells deep enough to trap their own X-ray gas. Because of the unlimited field of view of the all sky survey and the low background of the PSPC, we were able to measure the azimuthally averaged surface brightness of Coma out to approximately 100 arcmin, twice as far as was previously possible. Given the validity of our mass models, these new X-ray data imply that within 5/h(50) Mpc the binding mass of the Coma cluster is 1.8 +/- 0.6 x 10 exp 15/h(50) solar mass, and the fraction of cluster mass contained in hot gas is 0.30 +/- 0.14h(50) exp -3/2. Furthermore, the binding mass is more centrally concentrated than is the X-ray gas.

The Nature and Origin of UCDs in the Coma Cluster

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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.

Berenice Abbott (1898-1991, photographies

Directory of Open Access Journals (Sweden)

Juliette Mélia

2012-05-01

Full Text Available C’est la première fois que Berenice Abbott est exposée à Paris. Les cent vingt images et trente documents présentés au Jeu de Paume sont regroupés en quatre grandes séries, qui correspondent aux quatre grandes phases de sa carrière photographique. La première partie retrace son œuvre de portraitiste, qui commence à Paris au début des années 1920, où elle photographie des anonymes, mais aussi beaucoup d’artistes et d’écrivains tels que Marcel Duchamp, Jean Cocteau, James Joyce, ou encore Djuna...

THE HST/ACS COMA CLUSTER SURVEY. II. DATA DESCRIPTION AND SOURCE CATALOGS

International Nuclear Information System (INIS)

Hammer, Derek; Verdoes Kleijn, Gijs; Den Brok, Mark; Peletier, Reynier F.; Hoyos, Carlos; Balcells, Marc; Aguerri, Alfonso L.; Ferguson, Henry C.; Goudfrooij, Paul; Carter, David; Guzman, Rafael; Smith, Russell J.; Lucey, John R.; Graham, Alister W.; Trentham, Neil; Peng, Eric; Puzia, Thomas H.; Jogee, Shardha; Batcheldor, Dan; Bridges, Terry J.

2010-01-01

The Coma cluster, Abell 1656, was the target of an HST-ACS Treasury program designed for deep imaging in the F475W and F814W passbands. Although our survey was interrupted by the ACS instrument failure in early 2007, the partially completed survey still covers ∼50% of the core high-density region in Coma. Observations were performed for 25 fields that extend over a wide range of cluster-centric radii (∼1.75 Mpc or 1 0 ) with a total coverage area of 274 arcmin 2 . The majority of the fields are located near the core region of Coma (19/25 pointings) with six additional fields in the southwest region of the cluster. In this paper, we present reprocessed images and SEXTRACTOR source catalogs for our survey fields, including a detailed description of the methodology used for object detection and photometry, the subtraction of bright galaxies to measure faint underlying objects, and the use of simulations to assess the photometric accuracy and completeness of our catalogs. We also use simulations to perform aperture corrections for the SEXTRACTOR Kron magnitudes based only on the measured source flux and its half-light radius. We have performed photometry for ∼73,000 unique objects; approximately one-half of our detections are brighter than the 10σ point-source detection limit at F814W = 25.8 mag (AB). The slight majority of objects (60%) are unresolved or only marginally resolved by ACS. We estimate that Coma members are 5%-10% of all source detections, which consist of a large population of unresolved compact sources (primarily globular clusters but also ultra-compact dwarf galaxies) and a wide variety of extended galaxies from a cD galaxy to dwarf low surface brightness galaxies. The red sequence of Coma member galaxies has a color-magnitude relation with a constant slope and dispersion over 9 mag (-21 F814W < -13). The initial data release for the HST-ACS Coma Treasury program was made available to the public in 2008 August. The images and catalogs described

A DEEP VERY LARGE ARRAY RADIO CONTINUUM SURVEY OF THE CORE AND OUTSKIRTS OF THE COMA CLUSTER

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Miller, Neal A.; Hornschemeier, Ann E.; Mobasher, Bahram

2009-01-01

We present deep 1.4 GHz Very Large Array radio continuum observations of two ∼0.5 deg 2 fields in the Coma cluster of galaxies. The two fields, 'Coma 1' and 'Coma 3', correspond to the cluster core and southwest infall region and were selected on account of abundant preexisting multiwavelength data. In their most sensitive regions the radio data reach 22 μJy rms per 4.''4 beam, sufficient to detect (at 5σ) Coma member galaxies with L 1.4 G Hz = 1.3 x 10 20 W Hz -1 . The full catalog of radio detections is presented herein and consists of 1030 sources detected at ≥5σ, 628 of which are within the combined Coma 1 and Coma 3 area. We also provide optical identifications of the radio sources using data from the Sloan Digital Sky Survey. The depth of the radio observations allows us to detect active galactic nucleus in cluster elliptical galaxies with M r r r ∼ sun yr -1 .

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

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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.

Optical identifications of IRAS point sources: the Fornax, Hydra I and Coma clusters

International Nuclear Information System (INIS)

Wang, G.; Leggett, S.K.; Savage, A.

1991-01-01

We present optical identifications for 66 IRAS point sources in the region of the Fornax cluster of galaxies, 106 IRAS point sources in the region of the Hydra I cluster of galaxies (Abell 1060) and 59 IRAS point sources in the region of the Coma cluster of galaxies (Abell 1656). Eight other sources in Hydra I do not have optical counterparts and are very probably due to infrared cirrus. Twenty-three (35 per cent) of the Fornax sources are associated with stars and 43 (65 per cent) with galaxies; 48 (42 per cent) of the Hydra I sources are associated with stars and 58 (51 per cent) with galaxies; 18 (31 per cent) of the Coma sources are associated with stars and 41 (69 per cent) with galaxies. The stellar and infrared cirrus surface density is consistent with the galactic latitude of each field. (author)

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

Science.gov (United States)

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

Modified Newtonian dynamics and the Coma cluster

International Nuclear Information System (INIS)

The, L.S.; White, S.D.M.

1988-01-01

The consistency of Milgrom's theory of modified Newtonian dynamics is checked against optical and X-ray data for the Coma cluster of galaxies. It is found that viable models for the cluster containing no dark matter can be constructed. They require an extensive gaseous atmosphere through which galaxies move on near-radial orbits. The gas temperature is predicted to have a shallow minimum near the cluster center; this structure may conflict with the best X-ray spectra of the cluster. 18 references

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

Science.gov (United States)

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

MID-INFRARED EVIDENCE FOR ACCELERATED EVOLUTION IN COMPACT GROUP GALAXIES

International Nuclear Information System (INIS)

Walker, Lisa May; Johnson, Kelsey E.; Gallagher, Sarah C.; Hibbard, John E.; Hornschemeier, Ann E.; Tzanavaris, Panayiotis; Charlton, Jane C.; Jarrett, Thomas H.

2010-01-01

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 μm 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 show 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.

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

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Cordero, Juan P.; Campusano, Luis E.; Haines, Christopher P. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); De Propris, Roberto [Finnish Centre for Astronomy with ESO, University of Turku, Vaisalantie 20, Piikkio, FI-21500 (Finland); Weinzirl, Tim [School of Physics and Astronomy, The University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Jogee, Shardha, E-mail: jcordero@das.uchile.cl [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712-1205 (United States)

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, 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%.

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

International Nuclear Information System (INIS)

Cordero, Juan P.; Campusano, Luis E.; Haines, Christopher P.; De Propris, Roberto; Weinzirl, Tim; Jogee, Shardha

2016-01-01

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 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, 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%

ULTRA-COMPACT DWARFS IN THE CORE OF THE COMA CLUSTER

International Nuclear Information System (INIS)

Madrid, Juan P.; Graham, Alister W.; Forbes, Duncan A.; Spitler, Lee R.; Harris, William E.; Goudfrooij, Paul; Ferguson, Henry C.; Carter, David; Blakeslee, John P.

2010-01-01

We have discovered both a red and a blue subpopulation of ultra-compact dwarf (UCD) galaxy candidates in the Coma galaxy cluster. We analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera for Surveys Wide Field Channel as part of the Coma Cluster Treasury Survey and have fitted the light profiles of ∼5000 point-like sources in the vicinity of NGC 4874, one of the two central dominant galaxies of the Coma Cluster. Although almost all of these sources are globular clusters that remain unresolved, we found that 52 objects have effective radii between ∼10 and 66 pc, in the range spanned by dwarf globular transition objects (DGTOs) and UCDs. Of these 52 compact objects, 25 are brighter than M V ∼ -11 mag, a magnitude conventionally thought to separate UCDs and globular clusters. The UCD/DGTO candidates have the same color and luminosity distribution as the most luminous globular clusters within the red and blue subpopulations of the immensely rich NGC 4874 globular cluster system. Unlike standard globular clusters, blue and red UCD/DGTO subpopulations have the same median effective radius. The spatial distribution of UCD/DGTO candidates reveals that they congregate toward NGC 4874 and are not uniformly distributed. We find a relative deficit of UCD/DGTOs compared with globular clusters in the inner 15 kpc around NGC 4874; however, at larger radii UCD/DGTO and globular clusters follow the same spatial distribution.

The Hunt for Missing Dwarf Galaxies

Science.gov (United States)

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

IRAS galaxies and the large-scale structure in the CfA slice

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Babul, Arif; Postman, Marc

1990-01-01

The spatial distributions of the IRAS and the optical galaxies in the first CfA slice are compared. The IRAS galaxies are generally less clustered than optical ones, but their distribution is essentially identical to that of late-type optical galaxies. The discrepancy between the clustering properties of the IRAS and optical samples in the CfA slice region is found to be entirely due to the paucity of IRAS galaxies in the core of the Coma cluster. The spatial distributions of the IRAS and the optical galaxies, both late and early types, outside the dense core of the Coma cluster are entirely consistent with each other. This conflicts with the prediction of the linear biasing scenario.

Observing RAM Pressure Stripping and Morphological Transformation in the Coma Cluster

Science.gov (United States)

Gregg, Michael; West, Michael

2017-07-01

The two largest spirals in the Coma cluster, NGC4911 and NGC4921, are being vigorously ram-pressure stripped by the hot intracluster medium. Our 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. We have now obtained HST WFC3 imaging of five additional large Coma spirals to search for and investigate the effects of ram pressure stripping across the wider cluster environment. The results are equally spectacular as the first two examples. The geometry of the interactions in some cases allows an estimation of 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 yield insights into the spatial and temporal ISM-ICM interactions driving cluster galaxy evolution and ultimately transforming morphologies from spiral to S0. These processes were much more common in the early Universe when the intergalactic and intracluster components were initially created from stripping and destruction of member galaxies.

Globular Clusters for Faint Galaxies

Science.gov (United States)

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

Chameleonic contribution to the Sunyaev-Zel'dovich radial profile of the Coma cluster

International Nuclear Information System (INIS)

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

2011-01-01

We constrain the chameleonic Sunyaev-Zel'dovich (CSZ) effect in the Coma cluster from measurements of the Coma radial profile presented in the WMAP 7-year results. The CSZ effect arises from the interaction of a scalar (or pseudoscalar) particle with the cosmic microwave background in the magnetic field of galaxy clusters. We combine this radial profile data with SZ measurements towards the center of the Coma cluster in different frequency bands, to find ΔT SZ,RJ (0)=-410±50 μK and ΔT CSZ 204 GHz (0) > or approx. -50 μK (at 95% confidence) for the thermal SZ and CSZ effects in the cluster, respectively. This leads to an estimated bound on the photon to scalar (or pseudoscalar) coupling strength of g eff -10 GeV -1 .

VizieR Online Data Catalog: HST/ACS Coma cluster survey. II. (Hammer+, 2010)

NARCIS (Netherlands)

Hammer, D.; Verdoes Kleijn, G.; Hoyos, C.; den Brok, M.; Balcells, M.; Ferguson, H. C.; Goudfrooij, P.; Carter, D.; Guzman, R.; Peletier, R. F.; Smith, R. J.; Graham, A. W.; Trentham, N.; Peng, E.; Puzia, T. H.; Lucey, J. R.; Jogee, S.; Aguerri, A. L.; Batcheldor, D.; Bridges, T. J.; Chiboucas, K.; Davies, J. I.; Del Burgo, C.; Erwin, P.; Hornschemeier, A.; Hudson, M. J.; Huxor, A.; Jenkins, L.; Karick, A.; Khosroshahi, H.; Kourkchi, E.; Komiyama, Y.; Lotz, J.; Marzke, R. O.; Marinova, I.; Matkovic, A.; Merritt, D.; Miller, B. W.; Miller, N. A.; Mobasher, B.; Mouhcine, M.; Okamura, S.; Percival, S.; Phillipps, S.; Poggianti, B. M.; Price, J.; Sharples, R. M.; Tully, R. B.; Valentijn, E.

2010-01-01

This data release contains catalogs for the ACS Images in F475W and F814W bands of 25 fields in the Coma cluster of galaxies. Each field is about 202x202arcsec. Please see the release notes for further details. (25 data files).

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

Science.gov (United States)

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.

Substructure in clusters of galaxies

International Nuclear Information System (INIS)

Fitchett, M.J.

1988-01-01

Optical observations suggesting the existence of substructure in clusters of galaxies are examined. Models of cluster formation and methods used to detect substructure in clusters are reviewed. Consideration is given to classification schemes based on a departure of bright cluster galaxies from a spherically symmetric distribution, evidence for statistically significant substructure, and various types of substructure, including velocity, spatial, and spatial-velocity substructure. The substructure observed in the galaxy distribution in clusters is discussed, focusing on observations from general cluster samples, the Virgo cluster, the Hydra cluster, Centaurus, the Coma cluster, and the Cancer cluster. 88 refs

Low frequency radio observations of five rich clusters of galaxies

International Nuclear Information System (INIS)

Hanisch, R.J.; Erickson, W.C.

1980-01-01

Observations have been made at 43.0 and 73.8 MHz of five rich x-ray emitting clusters of galaxies: Abell 399/401, Abell 426 (the Perseus cluster), Abell 1367, Abell 1656 (the Coma cluster), and the Virgo cluster. A fan beam synthesis system has been used to search for extended radio emission, i.e., radio halos, in these clusters. Radio halos were detected in the Coma and Virgo clusters. No evidence was found for the existence of 3C84B, the halo source previously thought to exist in the Perseus cluster. If halo sources exist in Abell 399/401 or Abell 1367, they must be quite weak at frequencies less than 100 MHz. The observed sizes of the extended sources in Coma and Virgo imply that the rate of particle propagation away from strong radio galaxies greatly exceeds the Alfven velocity and is probably independent of particle energy

Galaxy angular momentum

International Nuclear Information System (INIS)

Thompson, L.A.

1974-01-01

In order to test the theories which purport to explain the origin of galaxy angular momentum, this study presents new data for about 1000 individual galaxies in eight rich clusters. The clusters which are studied include Virgo, A 119, A 400, A 1656 (Coma), A 2147, A 2151 (Hercules), A 2197, and A 2199. Selected samples of these data are used to investigate systematic alignment effects in clusters of galaxies and to investigate the intrinsic ellipticities of E, SO, and spiral galaxies. The following new results are reported: Galaxies in the cluster A 2197 show a significant alignment effect (chi 2 probability less than 0.0002), and the preferential direction of alignment corresponds approximately to the major axis of the overall cluster elongation. None of the other seven clusters show any significant alignment trends. The spiral galaxy samples in four clusters (Virgo, A 1656, A 2151, and A 2197) were large enough to analyze the number distributions of forward and reverse winding spirals. Large and small spiral galaxies have identical ellipticity distributions. Large E and SO galaxies tend to be more spherical, and small E and SO galaxies more flattened. The intrinsic ellipticities of E, SO, and spiral galaxies are the same for galaxies in the ''field'' and for galaxies in rich clusters. Six models of galaxy formation are reviewed, and the major []mphasis is placed on how each model explains the origin of galaxy angular momentum. (Diss. Abstr. Int., B)

The optical properties of galaxies in the Ophiuchus cluster

Science.gov (United States)

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

ENVIRONMENTAL EFFECTS ON THE METAL ENRICHMENT OF LOW-MASS GALAXIES IN NEARBY CLUSTERS

Energy Technology Data Exchange (ETDEWEB)

Petropoulou, V.; Vilchez, J.; Iglesias-Paramo, J. [Instituto de Astrofisica de Andalucia-C.S.I.C., Glorieta de la Astronomia, 18008 Granada (Spain)

2012-04-20

In this paper, we study the chemical history of low-mass star-forming (SF) galaxies in the local universe clusters Coma, A1367, A779, and A634. The aim of this work is to search for the imprint of the environment on the chemical evolution of these galaxies. Galaxy chemical evolution is linked to the star formation history, as well as to the gas interchange with the environment, and low-mass galaxies are well known to be vulnerable systems to environmental processes affecting both these parameters. For our study we have used spectra from the SDSS-III DR8. We have examined the spectroscopic properties of SF galaxies of stellar masses 10{sup 8}-10{sup 10} M{sub Sun }, located from the core to the cluster's outskirts. The gas-phase O/H and N/O chemical abundances have been derived using the latest empirical calibrations. We have examined the mass-metallicity relation of cluster galaxies, finding well-defined sequences. The slope of these sequences, for galaxies in low-mass clusters and galaxies at large cluster-centric distances, follows the predictions of recent hydrodynamic models. A flattening of this slope has been observed for galaxies located in the core of the two more massive clusters of the sample, principally in Coma, suggesting that the imprint of the cluster environment on the chemical evolution of SF galaxies should be sensitive to both the galaxy mass and the host cluster mass. The H I gas content of Coma and A1367 galaxies indicates that low-mass SF galaxies, located at the core of these clusters, have been severely affected by ram-pressure stripping (RPS). The observed mass-dependent enhancement of the metal content of low-mass galaxies in dense environments seems plausible, according to hydrodynamic simulations. This enhanced metal enrichment could be produced by the combination of effects such as wind reaccretion, due to pressure confinement by the intracluster medium (ICM), and the truncation of gas infall, as a result of the RPS. Thus, the

ENVIRONMENTAL EFFECTS ON THE METAL ENRICHMENT OF LOW-MASS GALAXIES IN NEARBY CLUSTERS

International Nuclear Information System (INIS)

Petropoulou, V.; Vílchez, J.; Iglesias-Páramo, J.

2012-01-01

In this paper, we study the chemical history of low-mass star-forming (SF) galaxies in the local universe clusters Coma, A1367, A779, and A634. The aim of this work is to search for the imprint of the environment on the chemical evolution of these galaxies. Galaxy chemical evolution is linked to the star formation history, as well as to the gas interchange with the environment, and low-mass galaxies are well known to be vulnerable systems to environmental processes affecting both these parameters. For our study we have used spectra from the SDSS-III DR8. We have examined the spectroscopic properties of SF galaxies of stellar masses 10 8 -10 10 M ☉ , located from the core to the cluster's outskirts. The gas-phase O/H and N/O chemical abundances have been derived using the latest empirical calibrations. We have examined the mass-metallicity relation of cluster galaxies, finding well-defined sequences. The slope of these sequences, for galaxies in low-mass clusters and galaxies at large cluster-centric distances, follows the predictions of recent hydrodynamic models. A flattening of this slope has been observed for galaxies located in the core of the two more massive clusters of the sample, principally in Coma, suggesting that the imprint of the cluster environment on the chemical evolution of SF galaxies should be sensitive to both the galaxy mass and the host cluster mass. The H I gas content of Coma and A1367 galaxies indicates that low-mass SF galaxies, located at the core of these clusters, have been severely affected by ram-pressure stripping (RPS). The observed mass-dependent enhancement of the metal content of low-mass galaxies in dense environments seems plausible, according to hydrodynamic simulations. This enhanced metal enrichment could be produced by the combination of effects such as wind reaccretion, due to pressure confinement by the intracluster medium (ICM), and the truncation of gas infall, as a result of the RPS. Thus, the properties of the ICM

SUZAKU OBSERVATIONS OF SUBHALOS IN THE COMA CLUSTER

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Sasaki, Toru; Matsushita, Kyoko; Sato, Kosuke [Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Okabe, Nobuhiro, E-mail: j1213703@ed.tus.ac.jp, E-mail: matusita@rs.kagu.tus.ac.jp [Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

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 that 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.

Radio investigations of clusters of galaxies

International Nuclear Information System (INIS)

Valentijn, E.A.

1978-01-01

This thesis contains a number of papers of the series entitled, A Westerbork Survey of Rich Clusters of Galaxies. The primary aim was to study the radio characteristics of cluster galaxies and especially the question whether their ''radio-activity'' is influenced by their location inside a cluster. It is enquired whether the presence of an intra-cluster medium (ICM), or the typical cluster evolution or cluster dynamical processes can give rise to radio-observable effects on the behaviour of cluster galaxies. 610 MHz WSRT observations of the Coma cluster (and radio observations of the Hercules supercluster) are presented. Extended radio sources in Abell clusters are then described. (Auth.)

Myxedema coma

Directory of Open Access Journals (Sweden)

Leonardo F. L. Rizzo

2017-08-01

Full Text Available 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

[Myxedema coma].

Science.gov (United States)

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.

EEG and Coma.

Science.gov (United States)

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.

COMA

Directory of Open Access Journals (Sweden)

P.F. Litvitsky

2010-01-01

Full Text Available The lecture reviews modern ideas of comatose conditions: their types, etiology, common key pathogenesis elements, stages, key manifestations, treatment principles; it characterizes the specifics of certain coma varieties and key impairments of consciousness. Key words: coma, stupor, sopor, hypoxia, impairments of energy supply for neurons.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2010;9(5:48-54

Photographic measurements of the diffuse light in the coma cluster

International Nuclear Information System (INIS)

Thuan, T.X.; Kormendy, J.

1977-01-01

The diffuse background light in the Coma cluster is measured using isodensity tracings of B, G, V, and R photographic plates taken with the Palomar 1.2-m Schmidt telescope. The isodensity contours are calibrated using the star profile derived by Kormendy (1973). Between 4 and 14 arc min from the center, the surface brightness of the diffuse light decreases from approximately 26 to approximately 28 G magnitudes arc sec -2 . The total magnitude in this annulus is G = 11.22, which is approximately 45 percent of the light in galaxies alone, or approximately 30 percent of the total. This does little to alleviate the ''missing mass'' problem. The isodensity contours and the equivalent profile of the diffuse light closely parallel the distribution of light in galaxies, implying no strong mass segregation. However, the background light appears to be bluer than the galaxies. This is consistent with the hypothesis that the background consists of stars tidally stripped from galaxies, which generally become bluer at larger radii. The present technique is very different from methods used in the past. Comparison of a variety of measurements shows that a reasonably consistent body of data on the background light now exists

Measurements of the gas temperature and iron abundance distribution in the Coma Cluster

International Nuclear Information System (INIS)

Hughes, J.P.; Gorenstein, P.; Fabricant, D.

1988-01-01

The medium energy X-ray detectors onboard the EXOSAT Observatory have been used to determine the gas temperature at several positions in the Coma Cluster of galaxies. Evidence is found at greater than 95 percent confidence for a higher temperature in the center of the cluster than in a position approximately 45 arcmin off-center. No difference in iron abundance is observed between the center and off-center regions and the equilibrium model for the distribution of elements in the Coma Cluster of Abramopoulos, Chanan, and Ku can be rejected with greater than 99.5 percent confidence, in favor of a model with more uniform composition. A phenomenological model is presented of the Coma Cluster, which is consistent with the data presented here, as well as the imaging data from the Einstein Observatory and the Tenma X-ray spectrum. The model has a central isothermal region of temperature about 9 keV extending to about 25 arcmin (about 1 Mpc). Beyond this radius the temperature falls as a polytrope with index about 1.6. 36 references

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

Science.gov (United States)

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.

Spectroscopic characterisation of the stellar content of ultra diffuse galaxies

Science.gov (United States)

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.

Prominent string of galaxies in Bootes: evidence for a Lagrangian singularity

Energy Technology Data Exchange (ETDEWEB)

Tago, E; Einasto, J; Saar, E

1986-01-15

An outstanding string of galaxies and of small groups in Bootes has been found during a study of bridges between the Coma and the Local superclusters. It lies on the boundary of a large void between the Hercules and the Local superclusters, has a length of 50 Mpc, is only a few megaparsecs wide and consists of non-elliptical galaxies. A possible explanation by a specific Lagrangian singularity at the formation, the imprint of which has survived in the present galaxy distribution, is proposed. (author).

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

Energy Technology Data Exchange (ETDEWEB)

Martínez-Delgado, David; Grebel, Eva K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12–14, D-69120 Heidelberg (Germany); Läsker, Ronald [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Sharina, Margarita; Karachentsev, Igor D. [Special Astrophysical Observatory, Russian Academy of Sciences (Russian Federation); Toloba, Elisa; Romanowsky, Aaron J. [University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Fliri, Jürgen [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38200 La Laguna, Tenerife (Spain); Beaton, Rachael [The Observatories of the Carnegie Institutions for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Valls-Gabaud, David [LERMA, CNRS UMR 8112, Observatoire de Paris, 61 Avenue de l’Observatoire, F-75014 Paris (France); Chonis, Taylor S. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Forbes, Duncan A. [Center for Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122 (Australia); Gallego-Laborda, J. [Fosca Nit Observatory, Montsec Astronomical Park, Ager (Spain); Teuwen, Karel [Remote Observatories Southern Alpes, Verclause (France); Gómez-Flechoso, M. A. [Departamento de Matemática Aplicada (Biomatemática), Universidad Complutense de Madrid, E-28040 Madrid (Spain); and others

2016-04-15

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 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 (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.

The Magnetic Field in Galaxies, Galaxy Clusters, and the InterGalactic Space

CERN Document Server

Dar, A; Dar, Arnon

2005-01-01

Magnetic fields of debated origin appear to permeate the Universe on all large scales. There is mounting evidence that supernovae produce not only roughly spherical ejecta and winds, but also highly relativistic jets of ordinary matter. These jets, which travel long distances, slow down by accelerating the matter encountered on their path to cosmic-ray energies. We show that, if the turbulent motions induced by the winds and the cosmic rays generate magnetic fields in rough energy equipartition, the predicted magnetic-field strengths coincide with the ones observed not only in galaxies (5 $\\mu$G in the Milky Way) but also in galaxy clusters (6 $\\mu$G in Coma). The prediction for the intergalactic (or inter-cluster) field is 50 nG.

GLOBULAR CLUSTERS INDICATE THAT ULTRA-DIFFUSE GALAXIES ARE DWARFS

Energy Technology Data Exchange (ETDEWEB)

Beasley, Michael A.; Trujillo, Ignacio, E-mail: beasley@iac.es [Instituto de Astrofisica de Canarias, Calle Via Láctea, La Laguna, Tenerife (Spain)

2016-10-10

We present an analysis of archival HST /ACS imaging in the F475W ( g {sub 475}), F606W ( V {sub 606}), and F814W ( I {sub 814}) bands of the globular cluster (GC) system of a large (3.4 kpc effective radius) ultra-diffuse galaxy (DF17) believed to be located in the Coma Cluster of galaxies. We detect 11 GCs down to the 5 σ completeness limit of the imaging ( I {sub 814} = 27 mag). Correcting for background and our detection limits yields a total population of GCs in this galaxy of 27 ± 5 and a V -band specific frequency S {sub N} = 28 ± 5. Based on comparisons to the GC systems of local galaxies, we show that both the absolute number and the colors of the GC system of DF17 are consistent with the GC system of a dark-matter-dominated dwarf galaxy with virial mass ∼9.0 × 10{sup 10} M {sub ⊙} and a dark-to-stellar mass ratio M {sub vir}/ M {sub star} ∼ 1000. Based on the stellar mass growth of the Milky Way, we show that DF17 cannot be understood as a failed Milky-Way-like system, but is more similar to quenched Large-Magellanic-Cloud-like systems. We find that the mean color of the GC population, g {sub 475}– I {sub 814} = 0.91 ± 0.05 mag, coincides with the peak of the color distribution of intracluster GCs and is also similar to those of the blue GCs in the outer regions of massive galaxies. We suggest that both the intracluster GC population in Coma and the blue peak in the GC populations of massive galaxies may be fed—at least in part—by the disrupted equivalents of systems such as DF17.

EEG in connection with coma.

Science.gov (United States)

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.

Functional coma.

Science.gov (United States)

Ludwig, L; McWhirter, L; Williams, S; Derry, C; Stone, J

2016-01-01

Functional coma - here defined as a prolonged motionless dissociative attack with absent or reduced response to external stimuli - is a relatively rare presentation. In this chapter we examine a wide range of terms used to describe states of unresponsiveness in which psychologic factors are relevant to etiology, such as depressive stupor, catatonia, nonepileptic "pseudostatus," and factitious disorders, and discuss the place of functional or psychogenic coma among these. Historically, diagnosis of functional coma has sometimes been reached after prolonged investigation and exclusion of other diagnoses. However, as is the case with other functional disorders, diagnosis should preferably be made on the basis of positive findings that provide evidence of inconsistency between an apparent comatose state and normal waking nervous system functioning. In our review of physical signs, we find some evidence for the presence of firm resistance to eye opening as reasonably sensitive and specific for functional coma, as well as the eye gaze sign, in which patients tend to look to the ground when turned on to one side. Noxious stimuli such as Harvey's sign (application of high-frequency vibrating tuning fork to the nasal mucosa) can also be helpful, although patients with this disorder are often remarkably unresponsive to usually painful stimuli, particularly as more commonly applied using sternal or nail bed pressure. The use of repeated painful stimuli is therefore not recommended. We also discuss the role of general anesthesia and other physiologic triggers to functional coma. © 2016 Elsevier B.V. All rights reserved.

Anions in Cometary Comae

Science.gov (United States)

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.

Chemical kinetics in the coma

International Nuclear Information System (INIS)

Huebner, W.F.

1980-01-01

Physical and chemical conditions in the coma of a bright new comet are related to the composition of the nucleus. Chemical and photolytic processes are described and related to distance in the coma above the nucleus and to heliocentric distance of the comet. Comparison of the model with coma observations leads to some restrictions about the nucleus composition. It is expected that these restrictions become more stringent as coma models are developed further and as observations become more detailed

Properties in the middle and far infrared radiation of spiral and irregular galaxies

International Nuclear Information System (INIS)

Contursi, Alessandra

1998-01-01

In the first part of this research thesis, the author reports the study in the middle infrared of H II regions belonging to Magellanic clouds. For this purpose, he presents different aspects of infrared emission by the interstellar medium: origin and evolution of interstellar grains, dust studied by astrophysical observations, dust models, infrared observations made by COBE and IRAS satellites, exploitation of the ISO satellite. He also presents the Small and Large Magellanic clouds, and reports the study of the H II N4 region of the large one, imagery and spectroscopy of the H II N66 region of the small one, and the study of silicate emission in the central region of N66. The second part reports the study of cluster normal spiral galaxies in the middle and far infrared. For this purpose, the author discusses the colours in the middle infrared of Virgo's and Coma's galaxies, discusses the properties in the infrared of spiral galaxies (Coma and A1367), based on observations made by ISO [fr

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

International Nuclear Information System (INIS)

Wik, Daniel R.; Sarazin, Craig L.; Finoguenov, Alexis; Matsushita, Kyoko; Nakazawa, Kazuhiro; Clarke, Tracy E.

2009-01-01

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 from 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 -12 erg s -1 cm -2 (20-80 keV, for Γ = 2.0), which implies a lower limit on the cluster-averaged magnetic field of B>0.15 μG. 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 ∼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.

Energy expenditure during barbiturate coma.

Science.gov (United States)

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.

Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions

Energy Technology Data Exchange (ETDEWEB)

Belokurov, V.; Zucker, Daniel B.; Evans, N.W.; Kleyna, J.T.; Koposov, S.; Hodgkin, S.T.; Irwin, M.J.; Gilmore, G.; Wilkinson, M.I.; Fellhauer, M.; Bramich, D.M.; /Cambridge U., Inst. of Astron. /Inst. Astron., Honolulu /Heidelberg, Max Planck Inst. Astron. /Los Alamos /Austin Peay State U. /Johns Hopkins U. /Rensselaer Poly. /Louisiana

2006-08-01

We present five new satellites of the Milky Way discovered in Sloan Digital Sky Survey (SDSS) imaging data, four of which were followed-up with either the Subaru or the Isaac Newton Telescopes. They include four probable new dwarf galaxies--one each in the constellations of Coma Berenices, Canes Venatici, Leo and Hercules--together with one unusually extended globular cluster, Segue 1. We provide distances, absolute magnitudes, half-light radii and color-magnitude diagrams for all five satellites. The morphological features of the color-magnitude diagrams are generally well described by the ridge line of the old, metal-poor globular cluster M92. In the last two years, a total of ten new Milky Way satellites with effective surface brightness {mu}{sub v} {approx}> 28 mag arcsec{sup -2} have been discovered in SDSS data. They are less luminous, more irregular and appear to be more metal-poor than the previously-known nine Milky Way dwarf spheroidals. The relationship between these objects and other populations is discussed. We note that there is a paucity of objects with half-light radii between {approx} 40 pc and {approx} 100 pc. We conjecture that this may represent the division between star clusters and dwarf galaxies.

Cats and Dogs, Hair and a Hero: A Quintet of New Milky Way Companions

Science.gov (United States)

Belokurov, V.; Zucker, D. B.; Evans, N. W.; Kleyna, J. T.; Koposov, S.; Hodgkin, S. T.; Irwin, M. J.; Gilmore, G.; Wilkinson, M. I.; Fellhauer, M.; Bramich, D. M.; Hewett, P. C.; Vidrih, S.; De Jong, J. T. A.; Smith, J. A.; Rix, H.-W.; Bell, E. F.; Wyse, R. F. G.; Newberg, H. J.; Mayeur, P. A.; Yanny, B.; Rockosi, C. M.; Gnedin, O. Y.; Schneider, D. P.; Beers, T. C.; Barentine, J. C.; Brewington, H.; Brinkmann, J.; Harvanek, M.; Kleinman, S. J.; Krzesinski, J.; Long, D.; Nitta, A.; Snedden, S. A.

2007-01-01

We present five new satellites of the Milky Way discovered in Sloan Digital Sky Survey (SDSS) imaging data, four of which were followed up with either the Subaru or the Isaac Newton Telescopes. They include four probable new dwarf galaxies-one each in the constellations of Coma Berenices, Canes Venatici, Leo, and Hercules-together with one unusually extended globular cluster, Segue 1. We provide distances, absolute magnitudes, half-light radii, and color-magnitude diagrams for all five satellites. The morphological features of the color-magnitude diagrams are generally well described by the ridge line of the old, metal-poor globular cluster M92. In the past two years, a total of 10 new Milky Way satellites with effective surface brightness μv>~28 mag arcsec-2 have been discovered in SDSS data. They are less luminous, more irregular, and apparently more metal-poor than the previously known nine Milky Way dwarf spheroidals. The relationship between these objects and other populations is discussed. We note that there is a paucity of objects with half-light radii between ~40 and ~100 pc. We conjecture that this may represent the division between star clusters and dwarf galaxies. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

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

International Nuclear Information System (INIS)

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

1975-01-01

We present the final Uhuru X-ray differential-energy spectra for the Perseus, Virgo, and Coma clusters of galaxies. The power-law and isothermal bremsstrahlung model forms, both with a low-energy cutoff, are given. For bremsstrahlung, the energy-dependent Gaunt factor is calculated by an improved method. The spectra, best fits to the Uhuru 2-10 keV data, are also compared with other observations of these sources in the energy range 0.1-100 keV. For Perseus, the data above 20 keV favor the bremsstrahlung fit marginally. For Virgo, the data of Catura et al. between 0.25 and 1.0 keV clearly favor the bremsstrahlung curve. For Coma, the weakest of the three sources, the data are less precise, but there is some evidence for a low-energy turnover or cutoff. The implications of such a cutoff are discussed briefly

Imaging in the diagnosis of coma

International Nuclear Information System (INIS)

Aubin, M.L.; Molho, M.

1989-01-01

Imaging has become one of the main methods to diagnose and monitor coma. CT is the technique of choice in the exploration of traumatic coma or spontaneous intracerebral haemorrhage, but MRI is better than CT to explore comas of ischaemic, infective, tumoral or toxic origin, as it provides earlier and more precise images [fr

[Coma in France today].

Science.gov (United States)

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.

Evolution of Late-type Galaxies in a Cluster Environment: Effects of High-speed Multiple Encounters with Early-type Galaxies

Science.gov (United States)

Hwang, Jeong-Sun; Park, Changbom; Banerjee, Arunima; Hwang, Ho Seong

2018-04-01

Late-type galaxies falling into a cluster would evolve being influenced by the interactions with both the cluster and the nearby cluster member galaxies. Most numerical studies, however, tend to focus on the effects of the former with little work done on those of the latter. We thus perform a numerical study on the evolution of a late-type galaxy interacting with neighboring early-type galaxies at high speed using hydrodynamic simulations. Based on the information obtained from the Coma cluster, we set up the simulations for the case where a Milky Way–like late-type galaxy experiences six consecutive collisions with twice as massive early-type galaxies having hot gas in their halos at the closest approach distances of 15–65 h ‑1 kpc at the relative velocities of 1500–1600 km s‑1. Our simulations show that the evolution of the late-type galaxy can be significantly affected by the accumulated effects of the high-speed multiple collisions with the early-type galaxies, such as on cold gas content and star formation activity of the late-type galaxy, particularly through the hydrodynamic interactions between cold disk and hot gas halos. We find that the late-type galaxy can lose most of its cold gas after the six collisions and have more star formation activity during the collisions. By comparing our simulation results with those of galaxy–cluster interactions, we claim that the role of the galaxy–galaxy interactions on the evolution of late-type galaxies in clusters could be comparable with that of the galaxy–cluster interactions, depending on the dynamical history.

Effects of Galaxy collisions on the structure and evolution of Galaxy clusters. I. Mass and luminosity functions and background light

International Nuclear Information System (INIS)

Miller, G.E.; Department of Astronomy, University of Texas at Austin)

1983-01-01

The role of galaxy collisions in controlling the form of the galaxy mass and luminosity functions and in creating a diffuse background light is investigated by means of a direct computer simulation. Galaxy collisions are treated in a realistic manner, including both galaxy mergers and tidal encounters. A large number of theoretical studies of a galaxy collisions were consulted to formulate the basic input physics of collision cross sections. Despite this large number of studies, there remains considerable uncertainty in the effects of a collision on a galaxy due mainly to our lack of knowledge of the orbital distribution of matter in galaxies. To improve this situation, some methods of semiempirical calibration are suggested: for example, a survey of background light in clusters of different richness and morphological classes. If real galaxies are represented by galaxy models where the bulk of the matter is on radial, rather than circular, orbits, then tidal collisions are more damaging and there are a number of interesting effects: Repeated tidal encounters lead to galaxy mass and luminosity functions which are largely independent of model parameters and the initial galaxy mass function. It appears unlikely that the form of the average present-day luminosity function characteristic of both field and cluster galaxies is due to collisions, but certain observed deviations from the average found by Heiligman and Turner and by Dressler may be a signature of collisions, in particular a flat faint-end slope. The amount of luminous matter stripped from the galaxies in the simulations agrees with the amount of diffuse background light seen in the Coma Cluster

KDG218, a nearby ultra-diffuse galaxy

Science.gov (United States)

Karachentsev, I. D.; Makarova, L. N.; Sharina, M. E.; Karachentseva, V. E.

2017-10-01

We present properties of the low-surface-brightness galaxy KDG218 observed with the HST/ACS. The galaxy has a half-light (effective) diameter of a e = 47″ and a central surface brightness of SB V (0) = 24.m4/□″. The galaxy remains unresolved with the HST/ACS, which implies its distance of D > 13.1 Mpc and linear effective diameter of A e > 3.0 kpc. We notice that KDG218 is most likely associated with a galaxy group around the massive lenticular NGC4958 galaxy at approximately 22 Mpc, or with the Virgo Southern Extension filament at approximately 16.5 Mpc. At these distances, the galaxy is classified as an ultra-diffuse galaxy (UDG) similar to those found in the Virgo, Fornax, and Coma clusters. We also present a sample of 15 UDG candidates in the Local Volume. These sample galaxies have the following mean parameters: 〈 D〉 = 5.1 Mpc, 〈 A e 〉 = 4.8 kpc, and 〈 SB B ( e)〉 = 27.m4/□″. All the local UDG candidates reside near massive galaxies located in the regions with the mean stellar mass density (within 1 Mpc) about 50 times greater than the average cosmic density. The local fraction of UDGs does not exceed 1.5% of the Local Volume population. We notice that the presented sample of local UDGs is a heterogeneous one containing irregular, transition, and tidal types, as well as objects consisting of an old stellar population.

Myxedema coma: diagnosis and treatment.

Science.gov (United States)

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.

Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

Energy Technology Data Exchange (ETDEWEB)

Sánchez-Conde, Miguel A. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Cannoni, Mirco; Gómez, Mario E. [Dpto. Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva (Spain); Zandanel, Fabio; Prada, Francisco, E-mail: masc@stanford.edu, E-mail: mirco.cannoni@dfa.uhu.es, E-mail: fabio@iaa.es, E-mail: mario.gomez@dfa.uhu.es, E-mail: fprada@iaa.es [Instituto de Astrofísica de Andalucía (CSIC), E-18008, Granada (Spain)

2011-12-01

In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Conde, Miguel A.; /KIPAC, Menlo Park /SLAC /IAC, La Laguna /Laguna U., Tenerife; Cannoni, Mirco; /Huelva U.; Zandanel, Fabio; /IAA, Granada; Gomez, Mario E.; /Huelva U.; Prada, Francisco; /IAA, Granada

2012-06-06

In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

[Brain function recovery after prolonged posttraumatic coma].

Science.gov (United States)

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.

Homeopathic treatment for prolonged postoperative coma: a case report.

Science.gov (United States)

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.

THE PLANCK SUNYAEV-ZEL'DOVICH VERSUS THE X-RAY VIEW OF THE COMA CLUSTER

International Nuclear Information System (INIS)

Fusco-Femiano, R.; Lapi, A.; Cavaliere, A.

2013-01-01

The Planck collaboration has recently published precise and resolved measurements of the Sunyaev-Zel'dovich (SZ) effect in Abell 1656 (the Coma cluster of galaxies), thus directly gauging the electron pressure profile in the intracluster plasma. On the other hand, such a quantity may be also derived from combining the density and temperature provided by X-ray observations of the thermal bremsstrahlung radiation emitted by the plasma. We find a model-independent tension between the SZ and the X-ray pressure, with the SZ one being definitely lower by 15%-20%. We propose that such a challenging tension can be resolved in terms of an additional, non-thermal support to the gravitational equilibrium of the intracluster plasma. This can be straightforwardly included in our Supermodel, so as to fit in detail the Planck SZ profile while being consistent with the X-ray observables. Possible origins of the non-thermal component include cosmic-ray protons, ongoing turbulence, and relativistic electrons; given the existing observational constraints on the first two options, here we focus on the third. For this to be effective, we find that the electron population must include not only an energetic tail accelerated to γ ∼> 10 3 responsible for the Coma radiohalo, but also many more, lower energy electrons. The electron acceleration is to be started by merging events similar to those that provided the very high central entropy of the thermal intracluster plasma in Coma.

Endozepine-4 levels are increased in hepatic coma.

Science.gov (United States)

Malaguarnera, Giulia; Vacante, Marco; Drago, Filippo; Bertino, Gaetano; Motta, Massimo; Giordano, Maria; Malaguarnera, Michele

2015-08-14

To evaluate the serum levels of endozepine-4, their relation with ammonia serum levels, the grading of coma and the severity of cirrhosis, in patients with hepatic coma. In this study we included 20 subjects with Hepatic coma, 20 subjects with minimal hepatic encephalopathy (MHE) and 20 subjects control. All subjects underwent blood analysis, Child Pugh and Model for End - stage liver disease (MELD) assessment, endozepine-4 analysis. Subjects with hepatic coma showed significant difference in endozepine-4 (P blood ammonia concentration was noted to be raised in patients with hepatic coma, with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia (P < 0.001). In patients with grade IV hepatic coma, endozepine levels were significantly higher compared to other groups. This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion, data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations.

Initial Diagnosis and Management of Coma.

Science.gov (United States)

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.

[Myxedema coma. A case reported].

Science.gov (United States)

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.

[The diagnosis and treatment of myxedema coma].

Science.gov (United States)

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.

Myxedema coma.

Science.gov (United States)

Kwaku, Maxwell P; Burman, Kenneth D

2007-01-01

Untreated or unrecognized hypothyroidism may progress to severe decompensated hypothyroidism or myxedema coma. Relatively few cases are reported in the literature since the first case was apparently reported from the St. Thomas Hospital in London in 1879. The paucity of cases may be due to either underreporting or improvement in the diagnosis and treatment of uncomplicated hypothyroidism. However, despite the ready availability of sensitive thyrotropin assays, the recognition and treatment of myxedema coma remains a challenge. Although thyroid hormone treatment is highly effective when combined with ventilatory and hemodynamic support in the intensive care unit setting, controversies abound on the optimal and most effective choice of thyroid hormone preparation: thyroxine and triiodothyronine and in what amount. Accumulated evidence now shows that proper use of either thyroxine alone or in combination with triiodothyronine may be effective therapy.

Postanoxic coma: prognosis after therapeutic hypothermia

NARCIS (Netherlands)

Bouwes, A.

2012-01-01

Postanoxic coma, also known as anoxic-ischemic coma, is a state of unconsciousness caused by global anoxia of the brain. The most common cause is primary cardiac arrest followed by successful cardiopulmonary resuscitation (CPR). Other causes include primary respiratory arrest, near-drowning,

Prognostic value of EEG in different etiological types of coma.

Science.gov (United States)

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; pEEG patterns' association with coma outcome only in hemorrhagic and traumatic coma (chi-sqr.=12.95; pEEG patterns and coma outcome. Low amplitude decreased power delta and theta frequencies correlated with SND in survived coma patients (r=+0.21; pEEG 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

Diffuse radio emission in the Coma cluster and Abell 1367: observations at 430 and 1400 MHz

International Nuclear Information System (INIS)

Hanisch, R.J.

1980-01-01

Two rich clusters of galaxies, Abell 1656 (the Coma cluster) and Abell 1367, have been mapped at both 430 and 1400 MHz with the 305-m telescope at Arecibo. The contribution to the observed radio emission due to known discrete sources has been calculated by convolving interferometrically determined source lists with observed Arecibo beam patterns, and maps of the diffuse radio emission alone have been constructed. Both clusters contain regions of diffuse radio emission, although the source in Coma is larger and much more luminous than the source in Abell 1367. The linear extent of the diffuse emission and its dependence on frequency have been used to study particle propagation rates and modes of diffusion in the intracluster medium. The possible correlations between the diffuse radio emission and x-ray emission in these clusters have been investigated, and it has been found that the observed x-ray luminosities can be accounted for if the intracluster gas is heated through Coulomb interactions with the relativistic electrons responsible for the diffuse radio emission

Extragalactic Gamma Ray Excess from Coma Supercluster Direction

Indian Academy of Sciences (India)

More precise analysis of EGRET data however, makes it possible to estimate the diffuse gamma ray in Coma supercluster (i.e., Coma\\A1367 supercluster) direction with a value of ( > 30MeV) ≃ 1.9 × 10-6 cm-2 s-1, which is considered to be an upper limit for the diffuse gamma ray due to Coma supercluster. The related ...

[Thyroid Storm and Myxedema Coma].

Science.gov (United States)

Milkau, Malte; Sayk, Friedhelm

2018-03-01

Thyroid storm and myxedema coma are the most severe clinical forms of thyroid dysfunction. While both hyper- and hypothyroidsm are common diseases, thyroid storm and myxedema coma are rare. Due to their unspecific signs and symptoms they are often difficult to diagnose. Both disorders are medical emergencies, which still show a significant mortality. The following article summarizes diagnostic tools and treatment options for these disorders. © Georg Thieme Verlag KG Stuttgart · New York.

Myxedema coma after esophagectomy.

Science.gov (United States)

Yuan, Yong; Hu, Yang; Xie, Tianpeng; Zhao, Yongfan

2010-07-01

For most patients with esophageal cancer, esophagectomy is an effective therapy. Perioperative management is critical for clinical outcomes after the operation. Great efforts should be made to avoid postoperative complications. We report myxedema coma, an emergency condition caused by severe hypothyroidism, after a patient underwent esophagectomy for esophageal cancer. The patient was successfully treated with intravenous levothyroxine. We strongly recommend that physicians test the thyroid hormone levels in patients with risk factors. If myxedema coma occurs, immediate use of intravenous levothyroxine is effective for this lethal complication. Copyright 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Elliptical shape of the coma cluster

International Nuclear Information System (INIS)

Schipper, L.; King, I.R.

1978-01-01

The elliptical shape of the Coma cluster is examined quantitatively. The degree of ellipticity is high and depends to some extent on the radial distance of the sample from the Coma center as well as on the brightness of the sample. The elliptical shape does not appear to be caused by rotation; other possible causes are briefly discussed

STAR FORMATION IN ULTRA-FAINT DWARFS: CONTINUOUS OR SINGLE-AGE BURSTS?

International Nuclear Information System (INIS)

Webster, David; Bland-Hawthorn, Joss; Sutherland, Ralph

2015-01-01

We model the chemical evolution of six ultra-faint dwarfs (UFDs): Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV, and Ursa Major I based on their recently determined star formation histories. We show that two single-age bursts cannot explain the observed [α/Fe] versus [Fe/H] distribution in these galaxies and that some self-enrichment is required within the first burst. An alternative scenario is modeled, in which star formation is continuous except for short interruptions when one or more supernovae temporarily blow the dense gas out from the center of the system. This model allows for self-enrichment and can reproduce the chemical abundances of the UFDs in which the second burst is only a trace population. We conclude that the most likely star formation history is one or two extended periods of star formation, with the first burst lasting for at least 100 Myr. As found in earlier work, the observed properties of UFDs can be explained by formation at a low mass (M vir ∼10 7 M ⊙ ), rather than being stripped remnants of much larger systems

STAR FORMATION IN ULTRA-FAINT DWARFS: CONTINUOUS OR SINGLE-AGE BURSTS?

Energy Technology Data Exchange (ETDEWEB)

Webster, David; Bland-Hawthorn, Joss [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Sutherland, Ralph, E-mail: d.webster@physics.usyd.edu.au [Research School of Astronomy and Astrophysics, Australian National University, Cotter Rd, Weston, ACT 2611 (Australia)

2015-01-30

We model the chemical evolution of six ultra-faint dwarfs (UFDs): Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV, and Ursa Major I based on their recently determined star formation histories. We show that two single-age bursts cannot explain the observed [α/Fe] versus [Fe/H] distribution in these galaxies and that some self-enrichment is required within the first burst. An alternative scenario is modeled, in which star formation is continuous except for short interruptions when one or more supernovae temporarily blow the dense gas out from the center of the system. This model allows for self-enrichment and can reproduce the chemical abundances of the UFDs in which the second burst is only a trace population. We conclude that the most likely star formation history is one or two extended periods of star formation, with the first burst lasting for at least 100 Myr. As found in earlier work, the observed properties of UFDs can be explained by formation at a low mass (M{sub vir}∼10{sup 7} M{sub ⊙}), rather than being stripped remnants of much larger systems.

Myxedema coma leading to respiratory depression in a dog

OpenAIRE

Atkinson, Kathryn; Aubert, Isabelle

2004-01-01

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

[Thyrotoxic storm and myxedema coma].

Science.gov (United States)

Takasu, N

1999-08-01

Thyrotoxic or hyperthyroid storm is a grave, life-threatening, but relatively infrequent medical emergency. Immediate causes of death in this emergency are severe hyperpyrexia and pulmonary edema associated with arrhythmias, shock, and coma. This emergency is found in Graves' patients most frequently. Myxedema coma is an emergency clinical state caused by severe deficiency of thyroid hormones. This crisis represents the extreme expression of hypothyroidism. While it is quite useful to elicit a history of previous hypothyroidism, thyroid surgery, or radioactive iodine treatment, it is not obtainable.

Evolution of disk galaxies and the SO problem, revisited

International Nuclear Information System (INIS)

Bothun, G.D.

1982-01-01

We begin by summerizing the relevant properties of clusters of galaxies in relation to their ability to alter the course of galaxy evolution. Previous work on the effect of environment on the evolution of disk galaxies is also summerized and critiqued. The extensive data base of Bothun is then used to reexamine the issue of the role of the environment in motivating the evolution of disk galaxies. This data base consists of radio and optical observations of approx.350 galaxies in the clusters Peg I, Cancer, Pices, Coma, A1367, Z74--23, Hercules, A539, and A400. The data are portrayed in the color-gas content plane [log M/sub H//L/sub B/ vs. (B--V)/sup T/ 0 ], and theoretical evolutionary tracks have been constructed in that plane to serve as an adjunct to data interpretation. All analysis is done solely on the basis of the measurable quantities themselves, as opposed to morphological considerations. We find that spiral galaxies exhibit such a wide range in their integrated properties that attempting to force then into ''narrow'' morphological bins is neither practical or physically meaningful. With respect to the question of environmental modification of disk galaxies in clusters, we find the great majority of the data to mitigate strongly against any global environmental processes as having been important in determining the particular evolutionary history of cluster galaxies. Our basic conclusion is that initial conditions of formation and variations in star formation histories have been more important than environmental influences in determining the present-day character of spiral galaxies in clusters. The key parameter may well be the amount of neutral hydrogen remaining after star formation in the bulge component has ceased

Intensive Care for Eclampic Coma

Directory of Open Access Journals (Sweden)

V. V. Moroz

2010-01-01

Full Text Available Objective: to enhance the efficiency of treatment of puerperas with eclampic coma, by substantiating, developing, and introducing new algorithms for correction of systemic hemodynamic, metabolic disturbances, and perfusion-metabolic changes in brain tissues. Subjects and methods. Studies were conducted in 18 puerperas with eclampic coma (Group 2 in whom the authors used a new treatment algorithm aimed at maintaining baseline cerebral perfusion pressure (CPP, restoring volemic levels at the expense of interstitial fluid. A control group (Group 1 included 30 patients who received conventional standard therapy. Regional cerebral circulation was measured by a non-invasive (inhalation radioisotopic method, by applying the tracer 131Xe, as described by V. D. Obrist et al., on a modified КПРДИ-1 apparatus (USSR. The rate of brain oxygen uptake was determined from the oxygen content between the artery and the internal jugular vein. Central hemodynamic parameters were studied by the direct method of right heart catheterization using a flow-directed Swan-Ganz catheter. The volumes of total and extracellular fluids were estimated using 20% urea and mannitol solutions, respectively, at 0.2 g/kg weight by the procedure of V. M. Mogen. Circulating blood volume (CBV was determined by a radioisotopic method using 131iodine albumin on an УPI-7 apparatus (USSR. Cerebral spinal fluid pressure was measured by an ИиНД apparatus. Studies were made in four steps: 1 on admission; 2 on days 2—3; 3 during emergence from coma; 4 before transition. Results. The use of the new algorithm for intensive care for eclampic coma, which is aimed at improving the perfusion metabolic provision of brain structures, with a reduction in mean blood pressure by 10—15% of the baseline level, by administering magnesium sulfate and nimodipine, and at compensating for CBV by high-molecular-weight hydroxyethylated starch (stabizol, ensured early emergence from a comatose state

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

Science.gov (United States)

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.

Which EEG patterns in coma are nonconvulsive status epilepticus?

Science.gov (United States)

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.

Myxedema coma in a patient with Down's syndrome.

Science.gov (United States)

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.

NON-TRAUMATIC COMA- INCIDENCE, AETIOLOGY AND OUTCOME

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Mallikarjun R. Patil

2017-10-01

Full Text Available BACKGROUND Acute non-traumatic coma is one of the most common paediatric emergencies, which arouses much anxiety and apprehension in both parents and physicians. Due to heterogeneity of causes in these patients, prediction of outcome is difficult and unfortunately no single clinical, laboratory or electrophysiological parameters singly predict their outcome. Aetiology of nontraumatic coma varies depending on different geographical area. We have attempted to find the incidence, aetiology and outcome and delineate neurological signs to predict the prognosis in this study. The aim of this study is to study the incidence, aetiology and outcome of non-traumatic coma in children. MATERIALS AND METHODS 100 consecutive cases of non-traumatic coma between 5months and 15 years of age were selected for the study. Clinical signs and findings were recorded at admission (‘0’ Hr and after ‘48’ Hrs. of hospital stay. Aetiology of coma is determined on the basis of clinical history, examination and relevant laboratory investigations by the treating physician. These children were followed up till the death in the hospital or discharged from the hospital. Discharged patients were asked for followup after 4 weeks. During this period, all of them were evaluated by formal neurological examination and for special sensory involvement. The neurological outcomes were categorised into 6 groups (I-VI based on the severity of neurological involvement. Chisquare test was applied to determine the predictors of outcome. RESULTS 1. The incidence of non-traumatic coma in our hospital based study was 8.02% of all paediatric admissions and 21.64% of all PICU admissions. 2. CNS infections contributed the majority (58% of cases. (Dengue encephalitis-28%, viral encephalitis-12%, TB meningitis-8%, pyogenic meningitis- 6%, Shigella encephalopathy-3% and cerebral malaria-1%. 3. Other non-infectious aetiologies were toxic and metabolic group- 21%, post status epilepticus- 9

Development and Preliminary Validation of the Coma Arousal Communication Scale.

Science.gov (United States)

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.

Predictors of Stroke and Coma After Neurosurgery: An ACS-NSQIP Analysis.

Science.gov (United States)

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 coma longer than 24 hours (P 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 XMM CLUSTER SURVEY: GALAXY MORPHOLOGIES AND THE COLOR-MAGNITUDE RELATION IN XMMXCS J2215.9 - 1738 AT z = 1.46

International Nuclear Information System (INIS)

Hilton, Matt; Stanford, S. Adam; Stott, John P.; Collins, Chris A.; Hoyle, Ben; Nichol, Robert C.; Davidson, Michael; Mann, Robert G.; Hosmer, Mark; Liddle, Andrew R.; Lloyd-Davies, Ed; Mehrtens, Nicola; Romer, A. Kathy; Sabirli, Kivanc; Sahlen, Martin; Kay, Scott T.; Miller, Christopher J.; Viana, Pedro T. P.; West, Michael J.; Barbary, Kyle

2009-01-01

We present a study of the morphological fractions and color-magnitude relation (CMR) in the most distant X-ray selected galaxy cluster currently known, XMMXCS J2215.9 - 1738 at z = 1.46, using a combination of optical imaging data obtained with the Hubble Space Telescope Advanced Camera for Surveys, and infrared data from the Multi-Object Infrared Camera and Spectrograph, mounted on the 8.2 m Subaru telescope. We find that the morphological mix of the cluster galaxy population is similar to clusters at z ∼ 1. Within the central 0.5 Mpc, approximately ∼62% of the galaxies identified as likely cluster members are ellipticals or S0s; and ∼38% are spirals or irregulars. Therefore, early-type galaxies were already entrenched as the dominant galaxy population in at least some clusters approximately ∼4.5 Gyr after the big bang. We measure the CMRs for the early-type galaxies, finding that the slope in the z 850 -J relation is consistent with that measured in the Coma cluster, some ∼9 Gyr earlier, although the uncertainty is large. In contrast, the measured intrinsic scatter about the CMR is more than three times the value measured in Coma, after conversion to rest-frame U - V. From comparison with stellar population synthesis models, the intrinsic scatter measurements imply mean luminosity-weighted ages for the early-type galaxies in J2215.9 - 1738 of ∼3 Gyr, corresponding to the major epoch of star formation coming to an end at z f ∼ 3-5. We find that the cluster exhibits evidence of the 'downsizing' phenomenon: the fraction of faint cluster members on the red sequence expressed using the Dwarf-to-Giant Ratio (DGR) is 0.32 ± 0.18 within a radius of 0.5R 200 . This is consistent with extrapolation of the redshift evolution of the DGR seen in cluster samples at z 1 clusters, we find a lack of very bright galaxies within the cluster.

Myxedema coma with cardiac tamponade and severe cardiomyopathy

OpenAIRE

Majid-Moosa, Abdulla; Schussler, Jeffrey M.; Mora, Adan

2015-01-01

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.

Myxedema coma with cardiac tamponade and severe cardiomyopathy.

Science.gov (United States)

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.

Diagnosis of reversible causes of coma.

Science.gov (United States)

Edlow, Jonathan A; Rabinstein, Alejandro; Traub, Stephen J; Wijdicks, Eelco F M

2014-12-06

Because coma has many causes, physicians must develop a structured, algorithmic approach to diagnose and treat reversible causes rapidly. The three main mechanisms of coma are structural brain lesions, diffuse neuronal dysfunction, and, rarely, psychiatric causes. The first priority is to stabilise the patient by treatment of life-threatening conditions, then to use the history, physical examination, and laboratory findings to identify structural causes and diagnose treatable disorders. Some patients have a clear diagnosis. In those who do not, the first decision is whether brain imaging is needed. Imaging should be done in post-traumatic coma or when structural brain lesions are probable or possible causes. Patients who do not undergo imaging should be reassessed regularly. If CT is non-diagnostic, a checklist should be used use to indicate whether advanced imaging is needed or evidence is present of a treatable poisoning or infection, seizures including non-convulsive status epilepticus, endocrinopathy, or thiamine deficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

Neutrino dark matter in clusters of galaxies

International Nuclear Information System (INIS)

Treumann, R A; Kull, A; Boehringer, H

2000-01-01

We present a model calculation for the radial matter density and mass distribution in two clusters of galaxies (Coma and A119) including cold dark matter, massive though light (≅2 eV) neutrino dark matter and collisional intra-cluster gas which emits x-ray radiation. The calculation uses an extension of the Lynden-Bell statistics to the choice of constant masses instead of constant volume. This allows proper inclusion of mixtures of particles of various masses in the gravitational interaction. When it is applied to the matter in the galaxy cluster the radial ROSAT x-ray luminosity profiles can be nicely accounted for. The result is that the statistics identifies the neutrino dark matter in the cluster centre as being degenerate in the sense of Lynden-Bell's spatial degeneracy. This implies that it is distributed in a way different from the classical assumption. The best fits are obtained for the ≅2 eV neutrinos. The fraction of these and their spatial distribution are of interest for understanding cluster dynamics and may have cosmological implications

Neutrino dark matter in clusters of galaxies

International Nuclear Information System (INIS)

Treumann, R.A.

2000-01-01

We present a model calculation for the radial matter density and mass distribution in two clusters of galaxies (Coma and A119) including cold dark matter, massive though light (approx. 2 eV) neutrino dark matter and collisional intra-cluster gas which emits x-ray radiation. The calculation uses an extension of the Lynden-Bell statistics to the choice of constant masses instead of constant volume. This allows proper inclusion of mixtures of particles of various masses in the gravitational interaction. When it is applied to the matter in the galaxy cluster the radial ROSAT x-ray luminosity profiles can be nicely accounted for. The result is that the statistics identifies the neutrino dark matter in the cluster centre as being degenerate in the sense of Lynden-Bell's spatial degeneracy. This implies that it is distributed in a way different from the classical assumption. The best fits are obtained for the approx. 2 eV neutrinos. The fraction of these and their spatial distribution are of interest for understanding cluster dynamics and may have cosmological implications. (author)

Thyroid gland disorder emergencies: thyroid storm and myxedema coma.

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

ZuHone, J. A. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Markevitch, M. [Astrophysics Science Division, X-ray Astrophysics Laboratory, Code 662, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Zhuravleva, I. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, California 94305-4085 (United States)

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, 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.

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

Science.gov (United States)

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.

Influence of coma aberration on aperture averaged scintillations in oceanic turbulence

Science.gov (United States)

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.

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

Science.gov (United States)

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 (pcoma have different effects on the BBB permeability depending on the energy metabolism. PMID:21619558

STAR-FORMING GALAXIES IN THE HERCULES CLUSTER: Hα IMAGING OF A2151

International Nuclear Information System (INIS)

Cedres, Bernabe; Iglesias-Paramo, Jorge; VIlchez, Jose Manuel; Reverte, Daniel; Petropoulou, Vasiliki; Hernandez-Fernandez, Jonathan

2009-01-01

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 ≤ M B ≤ -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 M B 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 M B , 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

Predicting outcome from coma : man-in-the-barrel syndrome as potential pitfall

NARCIS (Netherlands)

Elting, JW; Haaxma, R; De Keyser, J; Sulter, G.

The Glasgow coma scale motor score is often used in predicting outcome after hypoxic ischemic coma. Judicious care should be exerted when using this variable in predicting outcome in patients with coma following hypotension since borderzone infarction can obscure the clinical picture. We describe a

Coma blisters in children: case report and review of the literature.

Science.gov (United States)

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.

Color gradients in the coma of P/Halley

International Nuclear Information System (INIS)

Meech, K.

1988-01-01

Some important information relevant to the understanding of the gas/dust dynamics near the surface of a comet nucleus concerns knowledge of the grain composition and scattering properties as well as the particle size distribution of dust in the coma. Ground based measurements of light scattered from the dust comae can provide some information about the physical grain properties, in particular about the mean optically dominant grain size. Optical spectra of continua of nine comets presented by Jewitt and Meech, 1986, show that all of the scattered light is reddened with respect to the Sun. There is significant scatter in the amount of reddening seen for different comets. In the near IF regions, the reddening decreases until near 2 to 3 micrometers where the reflectivity is nearly neutral. It is of particular interest to see if there are any observable changes in the grain size distribution during outburst. Although no coma colar changes were observed during the Nov. 1985 outbursts, a color gradient within the coma has been observed in Halley. Radial color gradients in J, H, and K images of Halley as reported by Campins have not been observed by the author

The evolution of early-type galaxies in distant clusters

International Nuclear Information System (INIS)

Stanford, S.A.; Eisenhardt, P.R.; Dickinson, M.

1998-01-01

We present results from an optical-infrared photometric study of early-type (E+S0) galaxies in 19 galaxy clusters out to z=0.9. The galaxy sample is selected on the basis of morphologies determined from Hubble Space Telescope (HST) WFPC2 images and is photometrically defined in the K band in order to minimize redshift-dependent selection biases. Using new ground-based photometry in five optical and infrared bands for each cluster, we examine the evolution of the color-magnitude relation for early-type cluster galaxies, considering its slope, intercept, and color scatter around the mean relation. New multiwavelength photometry of galaxies in the Coma Cluster is used to provide a baseline sample at z∼0 with which to compare the distant clusters. The optical - IR colors of the early-type cluster galaxies become bluer with increasing redshift in a manner consistent with the passive evolution of an old stellar population formed at an early cosmic epoch. The degree of color evolution is similar for clusters at similar redshift and does not depend strongly on the optical richness or X-ray luminosity of the cluster, which suggests that the history of early-type galaxies is relatively insensitive to environment, at least above a certain density threshold. The slope of the color-magnitude relationship shows no significant change out to z=0.9, which provides evidence that it arises from a correlation between galaxy mass and metallicity, not age. Finally, the intrinsic scatter in the optical - IR colors of the galaxies is small and nearly constant with redshift, which indicates that the majority of giant, early-type galaxies in clusters share a common star formation history, with little perturbation due to uncorrelated episodes of later star formation. Taken together, our results are consistent with models in which most early-type galaxies in rich clusters are old, formed the majority of their stars at high redshift in a well-synchronized fashion, and evolved quiescently

Dynamic molecular oxygen production in cometary comae

Science.gov (United States)

Yao, Yunxi; Giapis, Konstantinos P.

2017-05-01

Abundant molecular oxygen was discovered in the coma of comet 67P/Churyumov-Gerasimenko. Its origin was ascribed to primordial gaseous O2 incorporated into the nucleus during the comet's formation. This thesis was put forward after discounting several O2 production mechanisms in comets, including photolysis and radiolysis of water, solar wind-surface interactions and gas-phase collisions. Here we report an original Eley-Rideal reaction mechanism, which permits direct O2 formation in single collisions of energetic water ions with oxidized cometary surface analogues. The reaction proceeds by H2O+ abstracting a surface O-atom, then forming an excited precursor state, which dissociates to produce O2-. Subsequent photo-detachment leads to molecular O2, whose presence in the coma may thus be linked directly to water molecules and their interaction with the solar wind. This abiotic O2 production mechanism is consistent with reported trends in the 67P coma and raises awareness of the role of energetic negative ions in comets.

An Atypical Case of Myxedema Coma with Concomitant Nonconvulsive Seizure.

Science.gov (United States)

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.

Capturing the Coma

Science.gov (United States)

2005-01-01

This image shows comet Tempel 1, as seen by the Deep Impact spacecraft on June 21, 2005. It was taken using the clear filter of the spacecraft's medium resolution imager camera. The spacecraft was 11,564,081.7 kilometers (7,185,920 miles) away from the comet. Twelve images were combined together, and a logarithmic stretch was applied to enhance the coma of the comet.

Bacteriology of aspiration pneumonia in patients with acute coma.

Science.gov (United States)

Lauterbach, Enise; Voss, Frederik; Gerigk, Roland; Lauterbach, Michael

2014-12-01

Loss of protective airway reflexes in patients with acute coma puts these patients at risk of aspiration pneumonia complicating the course of the primary disease. Available data vary considerably with regard to bacteriology, role of anaerobic bacteria, and antibiotic treatment. Our objective was to research the bacteriology of aspiration pneumonia in acute coma patients who were not pre-treated with antibiotics or hospitalized within 30 days prior to the event. We prospectively analyzed 127 patient records from adult patients admitted, intubated and ventilated to a tertiary medical intensive care unit with acute coma. Bacteriology and antibiotic resistance testing from tracheal aspirate sampled within 24 h after admission, blood cultures, ICU scores (APACHE II, SOFA), hematology, and clinical chemistry were assessed. Patients were followed up until death or hospital discharge. The majority of patients with acute coma suffered from acute cardiovascular disorders, predominantly myocardial infarction, followed by poisonings, and coma of unknown cause. In a majority of our patients, microaspiration resulted in overt infection. Most frequently S. aureus, H. influenzae, and S. pneumoniae were isolated. Anaerobic bacteria (Bacteroides spec., Fusobacteria, Prevotella spec.) were isolated from tracheal aspirate in a minority of patients, and predominantly as part of a mixed infection. Antibiotic monotherapy with a 2nd generation cephalosporin, or a 3rd generation gyrase inhibitor, was most effective in our patients regardless of the presence of anaerobic bacteria.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

An Atypical Case of Myxedema Coma with Concomitant Nonconvulsive Seizure

Directory of Open Access Journals (Sweden)

Pratik Patel

2016-01-01

Full Text Available 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.

Coma mixedematoso Myxedema coma

Directory of Open Access Journals (Sweden)

Lisette Leal Curí

2012-12-01

Full Text Available El coma mixedematoso es la forma más severa y profunda del hipotiroidismo. Se presenta con mayor frecuencia en mujeres y ancianos. Entre los factores precipitantes se encuentran: la sepsis, la exposición al frío, los eventos agudos graves, el uso de anestésicos, sedantes o narcóticos, así como la descontinuación del tratamiento sustitutivo con hormonas tiroideas, entre otros. El diagnóstico clínico se realiza por la presencia de síntomas y signos característicos de un hipotiroidismo severo, con hipotermia y alteraciones de la conciencia. Apoyan este diagnóstico los hallazgos de laboratorio: hiponatremia, hipoxemia, hipercapnia, alteraciones hemoquímicas y el aumento de la tirotropina por la disminución de las hormonas tiroideas en el caso de la enfermedad primaria. El tratamiento se debe realizar en una unidad de cuidados intensivos, con monitorización, medidas de soporte respiratorio y cardiovascular, calentamiento corporal interno, hidratación, corrección de la hipotensión y de los trastornos electrolíticos. Se administrarán, además, glucocorticoides, antibióticos de amplio espectro y hormonas tiroideas. La evolución depende de la demora en el inicio del tratamiento, la edad, las comorbilidades, la hipotermia persistente y las complicaciones asociadas.Myxedema coma is the most severe and deepest form of hypothyroidism. It occurs more often in the women and the elderly. Among the unleashing factors found are sepsis, exposure to cold, acute severe events, use of anesthetic drugs, sedatives or narcotics as well as the interruption of the replacement treatment with thyroid hormones, among others. The clinical diagnosis is based on the presence of symptoms and signs that are characteristic of severe hypothyroidism, with hypothermia and altered consciousness. This diagnosis is also supported by the lab findings: hyponatremia, hypoxemia, hypercapnia, hemochemical alterations and the rise of thyrotropin due to the decrease of

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

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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.

Development of an objective tool for the diagnosis of myxedema coma.

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

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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.

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

Energy Technology Data Exchange (ETDEWEB)

Kenney, Jeffrey D. P.; Abramson, Anne [Yale University Astronomy Department, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Bravo-Alfaro, Hector, E-mail: jeff.kenney@yale.edu [Institut d’Astrophysique de Paris, CNRS/UPMC, 98bis, Boulevard Arago F-75014, Paris (France)

2015-08-15

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 separates 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.

Coma Associated with Microscopy-Diagnosed Plasmodium vivax: A Prospective Study in Papua, Indonesia

Science.gov (United States)

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 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

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

OpenAIRE

Dixit, Siddharth; 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 o...

Contemporary approach to neurologic prognostication of coma after cardiac arrest.

Science.gov (United States)

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.

Jet Morphology and Coma Analysis of Comet 103P/Hartley 2

Science.gov (United States)

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.

The relation between persistent coma and brain ischemia after severe brain injury.

Science.gov (United States)

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.

The outflow speed of the coma of Halley's comet

International Nuclear Information System (INIS)

Combi, M.R.

1989-01-01

Data concerning the outflow speed of the coma of Comet Halley are studied in relation to a generalization of the coupled pure-gas-dynamic/Monte Carlo model of Combi and Smyth (1988) to include the dusty-gas dynamics of the inner coma. Measurements made by the Giotto neutral-gas spectrometer, IR water observations from the Kuiper Airborne Observatory, and Doppler radio line profiles of HCN and OH are used to examine the radial dependence of the outflow speed, the asymmetry in the outflow speed, and the overall heliocentric distance dependence of the Doppler profiles, respectively. The results suggest that the model makes it possible to understand the gross long-term behavior and radial structure of the dynamics of the cometary coma. 23 refs

Myxedema coma in a patient with subclinical hypothyroidism.

Science.gov (United States)

Mallipedhi, Akhila; Vali, Hamza; Okosieme, Onyebuchi

2011-01-01

Myxedema coma is the extreme manifestation of hypothyroidism, typically seen in patients with severe biochemical hypothyroidism. Its occurrence in association with subclinical hypothyroidism is extremely unusual. We describe a patient with subclinical hypothyroidism who developed clinical manifestations of myxedema coma. A 47-year-old woman presented to our endocrine clinic with complaints of fatigue and biochemical findings of subclinical hypothyroidism. She was started on treatment with thyroxine (T4) but remained unwell and was later admitted to hospital with hormone profile showing persisting subclinical hypothyroidism (elevated thyrotropin and normal free T4 [FT4] and free triiodothyronine [FT3]): FT4 10.7 pmol/L (reference range 10.3-24.5), FT3 2.7 pmol/L (reference range 2.67-7.03), and thyrotropin 6.09 mU/L (reference range 0.4-4.0). She subsequently developed hypothermia (temperature 33.2°C), circulatory collapse, and coma. Biochemical profile showed hyponatremia, elevated creatinine phosphokinase, metabolic acidosis, and renal failure. An echocardiogram revealed a moderate-sized pericardial effusion. We diagnosed myxedema coma and started treatment with intravenous T3. She responded dramatically with improvement in level of consciousness and normalization of metabolic parameters. We found no explanation other than hypothyroidism to account for the presentation. Adrenocorticotrophic hormone (ACTH) stimulation tests excluded adrenal insufficiency, and serum gonadotrophins were within the normal reference range. FT4 estimation by equilibrium dialysis excluded analytical interference, and molecular analysis for the thyroid hormone receptor β gene associated with thyroid hormone resistance was negative. To the best of our knowledge this is the first report of myxedema coma in a patient with subclinical hypothyroidism. The reason for normal thyroid hormone levels is unclear but may reflect deviation from a higher pre-morbid set-point. The case

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

Science.gov (United States)

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.

Comet coma sample return instrument

Science.gov (United States)

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.

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

Science.gov (United States)

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

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

Science.gov (United States)

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.

Molecular Gas Dominated 50 kpc Ram Pressure Stripped Tail of the Coma Galaxy D100

Czech Academy of Sciences Publication Activity Database

Jáchym, Pavel; Sun, M.; Kenney, J.D.P.; Cortese, L.; Combes, F.; Yagi, M.; Yoshida, M.; Palouš, Jan; Roediger, E.

2017-01-01

Roč. 839, č. 2 (2017), 114/1-114/15 ISSN 0004-637X R&D Projects: GA MŠk LG14013; GA ČR GA15-06012S; GA MŠk(CZ) LM2015067 Institutional support: RVO:67985815 Keywords : galaxies * cluster s * evolution Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

PCA/HEXTE Observations of Coma and A2319

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Marchegiani, Paolo; Colafrancesco, Sergio, E-mail: Paolo.Marchegiani@wits.ac.za, E-mail: Sergio.Colafrancesco@wits.ac.za [School of Physics, University of the Witwatersrand, Private Bag 3, WITS-2050, Johannesburg (South Africa)

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 in 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

Diagnosis of myxedema coma complicated by renal failure: a case report.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Disruption of posteromedial large-scale neural communication predicts recovery from coma.

Science.gov (United States)

Silva, Stein; de Pasquale, Francesco; Vuillaume, Corine; Riu, Beatrice; Loubinoux, Isabelle; Geeraerts, Thomas; Seguin, Thierry; Bounes, Vincent; Fourcade, Olivier; Demonet, Jean-Francois; Péran, Patrice

2015-12-08

We hypothesize that the major consciousness deficit observed in coma is due to the breakdown of long-range neuronal communication supported by precuneus and posterior cingulate cortex (PCC), and that prognosis depends on a specific connectivity pattern in these networks. We compared 27 prospectively recruited comatose patients who had severe brain injury (Glasgow Coma Scale score Coma Recovery Scale-Revised (CRS-R). Patients who were comatose showed a significant disruption of functional connectivity of brain areas spontaneously synchronized with PCC, globally notwithstanding etiology. The functional connectivity strength between PCC and medial prefrontal cortex (mPFC) was significantly different between comatose patients who went on to recover and those who eventually scored an unfavorable outcome 3 months after brain injury (Kruskal-Wallis test, p coma. Sparing of functional connectivity between PCC and mPFC may predict patient outcome, and further studies are needed to substantiate this potential prognosis biomarker. © 2015 American Academy of Neurology.

Alpha coma in an adolescent with diabetic ketoacidosis.

Science.gov (United States)

Ostojic, Slavica; Vukovic, Rade; Milenkovic, Tatjana; Mitrovic, Katarina; Djuric, Milena; Nikolic, Ljubica

2017-01-01

Ostojic S, Vukovic R, Milenkovic T, Mitrovic K, Djuric M, Nikolic L. Alpha coma in an adolescent with diabetic ketoacidosis. Turk J Pediatr 2017; 59: 318-321. This is the first report of alpha coma (AC) caused by brain edema in a patient with diabetic ketoacidosis (DKA). A previously healthy 15-year-old girl was admitted to the intensive care unit due to altered state of consciousness during the course of treatment for DKA. Patient was in a coma, intubated and had tachycardia with poor peripheral perfusion. Results of laboratory analyses indicated severe DKA and computed tomography scan indicated diffuse brain edema. The EEG pattern showed uniform alpha activity. Treatment with intravenous fluids, insulin and mannitol was started. Patient`s state of consciousness gradually improved and on the third day she was extubated. On the fifth day, her neurologic status and EEG findings were completely normal with no residual neurological deficits. In conclusion, although AC is associated with a high fatality rate, favorable outcome can be achieved with prompt recognition and treatment of cerebral edema in pediatric patients with DKA.

EXTINCTION IN THE COMA OF COMET 17P/HOLMES

Energy Technology Data Exchange (ETDEWEB)

Lacerda, Pedro [Astrophysics Research Centre, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Jewitt, David, E-mail: lacerda.pedro@gmail.com [Department of Earth and Space Sciences, University of California Los Angeles (UCLA), 595 Charles Young Drive, Los Angeles, CA 90095-1567 (United States)

2012-11-20

On 2007 October 29, the outbursting comet 17P/Holmes passed within 0.''79 of a background star. We recorded the event using optical, narrowband photometry and detect a 3%-4% dip in stellar brightness bracketing the time of closest approach to the comet nucleus. The detected dimming implies an optical depth {tau} Almost-Equal-To 0.04 at 1.''5 from the nucleus and an optical depth toward the nucleus center {tau}{sub n} < 13.3. At the time of our observations, the coma was optically thick only within {rho} {approx}< 0.''01 from the nucleus. By combining the measured extinction and the scattered light from the coma, we estimate a dust red albedo p{sub d} = 0.006 {+-} 0.002 at {alpha} = 16 Degree-Sign phase angle. Our measurements place the most stringent constraints on the extinction optical depth of any cometary coma.

Split high-dose oral levothyroxine treatment as a successful therapy option in myxedema coma.

Science.gov (United States)

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.

Coma morphology of comet 67P controlled by insolation over irregular nucleus

Science.gov (United States)

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.

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

Science.gov (United States)

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 (pcoma and poor outcome in SAH are associated with an aneurysmal origin and do not characterize naSAH. Copyright © 2013 Elsevier B.V. All rights reserved.

Diagnosis of myxedema coma complicated by renal failure: a case report

OpenAIRE

Takamura, Akiteru; Sangen, Ryusho; Furumura, Yoshiki; Usuda, Daisuke; Kasamaki, Yuji; Kanda, Tsugiyasu

2017-01-01

Key Clinical Message 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.

The X-ray morphology of the relaxed cluster of galaxies A2256. I - Evidence for a merger event

Science.gov (United States)

Briel, U. G.; Henry, J. P.; Schwarz, R. A.; Boehringer, H.; Ebeling, H.

1991-01-01

The rich cluster of galaxies A2256 are studied by utilizing the imaging proportional counter on board the X-ray observatory ROSAT. A2256 is considered to be a relaxed Coma-like cluster which is dynamically well evolved. Cleara evidence, however, is found for substructure in A2256. The X-ray surface brightness distribution reveals two separate maxima in the center; one of which is coincident with the central cD galaxy while the morphology of the other shows indications that it is merging with the main cluster body. The X-ray temperatures of the two maxima are different; the probable merging object being about a factor of five cooler than the cluster. The previously measured broad velocity distribution supports the idea that a merger is occurring in this cluster.

The Spinning Corona of FK Comae

Science.gov (United States)

Kashyap, Vinay

2010-09-01

FK Comae is an ultra-fast rotating, single yellow giant, product of a recent W UMa merger. Extraordinary levels of FUV and X-ray emission rate FK Comae a coronal powerhouse on par with the most extreme of the better known activity heavyweights: short-period RS CVn binaries. As a single star, FK Comae has clear advantages as a laboratory for exploring the outer limits of magnetospheric activity among the coronal cool stars. FK Comae has a long history of attention at optical and X-ray wavelengths, thanks to its generously spotted surface, and proclivity to flare regularly at high energies. FUSE discovered ultra-broad, redshifted profiles of OVI and CIII, but unfortunately the singular observation could not be repeated, thanks to the satellite's flaky attitude system. The remarkable FUV spectrum was taken just a few months before STIS failed in 2004, so there was no opportunity to turn the more powerful gaze of Hubble to the task. Now, finally, the amazing sensitivity of Cosmic Origins Spectrograph can be brought to bear: a single orbit can capture an FUV spectrum of FK Comae with S/N at instrumental limits for bright lines, and digging down to faint FeXXI 1354 {bridge to the coordinated Chandra HETGS pointing we are carrying out}.We will trace how the bright FUV regions relate spatially to the photospheric dark spots, to inform ideas of coronal structure and heating in these advanced objects. We will probe whether a global magnetosphere exists, and whether the field lines are loaded with hot coronal gas {>10 MK}, as well as the cooler 0.3 MK material already suggested by highly broadened FUSE OVI. Further, we will test whether the striking 100 km/s redshifts of the FUV lines, and similar shifts seen in NeX by Chandra HETGS, are caused by persistent coronal flows {outflows, perhaps implicated in magnetic braking; or inflows, like "coronal rain" on the Sun}. Our method is to exploit, on the one hand, emission-line "Doppler imaging," whereby bright surface regions are

Split high‐dose oral levothyroxine treatment as a successful therapy option in myxedema coma

OpenAIRE

Charoensri, Suranut; Sriphrapradang, Chutintorn; Nimitphong, Hataikarn

2017-01-01

Key Clinical Message 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.

Testing chameleon gravity with the Coma cluster

International Nuclear Information System (INIS)

Terukina, Ayumu; Yamamoto, Kazuhiro; Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C.

2014-01-01

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 extra 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 R0 | < 6 × 10 −5 , which is currently the tightest constraint on cosmological scales

Testing chameleon gravity with the Coma cluster

Energy Technology Data Exchange (ETDEWEB)

Terukina, Ayumu; Yamamoto, Kazuhiro [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Kagamiyama 1-3-1, 739-8526 (Japan); Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C., E-mail: telkina@theo.phys.sci.hiroshima-u.ac.jp, E-mail: lucas.lombriser@port.ac.uk, E-mail: kazuhiro@hiroshima-u.ac.jp, E-mail: david.bacon@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: bob.nichol@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom)

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 extra 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.

Acute Kidney Injury as a Risk Factor for Delirium and Coma during Critical Illness.

Science.gov (United States)

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.

An Atypical Case of Myxedema Coma with Concomitant Nonconvulsive Seizure

OpenAIRE

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 expr...

CHANDRA OBSERVATION OF ABELL 1142: A COOL-CORE CLUSTER LACKING A CENTRAL BRIGHTEST CLUSTER GALAXY?

Energy Technology Data Exchange (ETDEWEB)

Su, Yuanyuan; Weeren, Reinout van [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buote, David A. [Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Gastaldello, Fabio, E-mail: yuanyuan.su@cfa.harvard.edu [INAF-IASF-Milano, Via E. Bassini 15, I-20133 Milano (Italy)

2016-04-10

Abell 1142 is a low-mass galaxy cluster at low redshift containing two comparable brightest cluster galaxies (BCGs) resembling a scaled-down version of the Coma Cluster. Our Chandra analysis reveals an X-ray emission peak, roughly 100 kpc away from either BCG, which we identify as the cluster center. The emission center manifests itself as a second beta-model surface brightness component distinct from that of the cluster on larger scales. The center is also substantially cooler and more metal-rich than the surrounding intracluster medium (ICM), which makes Abell 1142 appear to be a cool-core cluster. The redshift distribution of its member galaxies indicates that Abell 1142 may contain two subclusters, each of which contain one BCG. The BCGs are merging at a relative velocity of ≈1200 km s{sup −1}. This ongoing merger may have shock-heated the ICM from ≈2 keV to above 3 keV, which would explain the anomalous L{sub X}–T{sub X} scaling relation for this system. This merger may have displaced the metal-enriched “cool core” of either of the subclusters from the BCG. The southern BCG consists of three individual galaxies residing within a radius of 5 kpc in projection. These galaxies should rapidly sink into the subcluster center due to the dynamical friction of a cuspy cold dark matter halo.

[Hysterical pseudo-coma: A case report].

Science.gov (United States)

Chouaib, N; Chouaib, H; Belyamani, L; Otheman, Y; Bichra, M Z

2015-09-01

Hysterical pseudo-coma corresponds to a state of clinical sleep with contrasting waking electroencephalogram. It can last several hours or even several days in the absence of an underlying organic disease. In psychiatry, this disorder is currently part of the "dissociative disorder not otherwise specified". Through this case report, we describe the evolution of a hysterical pseudo-coma that lasted four days in a 28-year-old man. The normality of biological, radiological and electroencephalographic assessments, and responsiveness of the patient during the implementation of a nasogastric tube, led us to suspect a mental origin. An adapted psychiatric care allowed the patient to recover his autonomy after three days of hospitalization. This had prevented the escalation of explorations and invasive treatments. However, the search for organic comorbidity and its management remains a priority. Copyright © 2014 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

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

Science.gov (United States)

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).

The Complex Outgassing of Comets and the Resulting Coma, a Direct Simulation Monte-Carlo Approach

Science.gov (United States)

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

Therapeutic burst-suppression coma in pediatric febrile refractory status epilepticus.

Science.gov (United States)

Lin, Jainn-Jim; Chou, Cheng-Che; Lan, Shih-Yun; Hsiao, Hsiang-Ju; Wang, Yu; Chan, Oi-Wa; Hsia, Shao-Hsuan; Wang, Huei-Shyong; Lin, Kuang-Lin

2017-09-01

Evidence for the beneficial effect of therapeutic burst-suppression coma in pediatric patients with febrile refractory status epilepticus is limited, and the clinical outcomes of this treatment strategy are largely unknown. Therefore, the aim of this study was to explore the outcomes of therapeutic burst-suppression coma in a series of children with febrile refractory status epilepticus. We retrospectively reviewed consecutive pediatric patients with febrile refractory status epilepticus admitted to our pediatric intensive care unit between January 2000 and December 2013. The clinical characteristics were analyzed. Thirty-five patients (23 boys; age range: 1-18years) were enrolled, of whom 28 (80%) developed super-refractory status epilepticus. All of the patients received the continuous administration of intravenous antiepileptic drugs for febrile refractory status epilepticus, and 26 (74.3%) achieved therapeutic burst-suppression coma. All of the patients received mechanical ventilatory support, and 26 (74.3%) received inotropic agents. Eight (22.9%) patients died within 1month. The neurologically functional outcomes at 6months were good in six (27.3%) of the 22 survivors, of whom two returned to clinical baseline. The patients with therapeutic burst-suppression coma were significantly associated with hemodynamic support than the patients with electrographic seizures control (p=0.03), and had a trend of higher 1-month mortality rate, worse 6months outcomes, and a longer duration of hospitalization. Our results suggest that therapeutic burst-suppression coma to treat febrile refractory status epilepticus may lead to an increased risk of hemodynamic instability and a trend of worse outcomes. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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.

Music therapy for coma patients: preliminary results.

Science.gov (United States)

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 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.

[Thyroid emergencies : Thyroid storm and myxedema coma].

Science.gov (United States)

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.

Prediction of Recovery from Coma After CPR

Science.gov (United States)

... to pain. There is good evidence* that myoclonus status epilepticus within the first day after CPR accurately predicts poor recovery from coma. Myoclonus status epilepticus is a constant twitching of muscles, including the ...

DARK ENERGY AND KEY PHYSICAL PARAMETERS OF CLUSTERS OF GALAXIES

Directory of Open Access Journals (Sweden)

Gennady S. Bisnovatyi-Kogan

2013-12-01

Full Text Available We study physics of clusters of galaxies embedded in the cosmic dark energy background. The equilibrium and stability of polytropic spheres with equation of state of the matter             P = Kpγ, γ = 1 + 1/n, in presence of a non-zero cosmological constant is investigated. The equilibrium state exists only for central densities p0 larger than the critical value pc and there are no static solutions at p0Coma cluster, are consistent with the assumption that the local density of dark energy on the scale of clusters of galaxies is the same as on the global cosmological scales.

An analysis of CCD images of the coma of Comet Halley. Final report, October 1989-September 1990

International Nuclear Information System (INIS)

Combi, M.

1990-12-01

The analysis of selected CCD images of the coma of comet P/Halley is presented. The images were taken using specially designed filters that isolate regions of a comet's spectrum such that only sunlight which has been scattered by the dust in the coma is recorded. The modeling analysis objective is to make use of the skills developed in the development of Monte Carlo particle trajectory models for the distributions of gas species in cometary comae and to use those models as a basis for a new dust coma model. This model will include a self-consistant picture of the time-dependent dusty-gas dynamics of the inner coma and the three-dimensional time-dependent trajectories of the dust particles under the influence of solar gravity and solar radiation pressure in the outer coma. The model is intended to be used as a tool to analyze selected images from the two sets of CCD images with the hope that it will help the understanding of the effects of a number of important processes on the spatial morphology of the observed dust coma. The processes of importance to the observed dust coma include: (1) the dust particle size distribution function; (2) the terminal velocities of various sized dust particles in the inner coma; (3) the radiation scattering properties of dust particles, which are important both in terms of the observe scattered radiation and the radiation pressure acceleration on dust particles; (4) the fragmentation and/or vaporization of dust particles; and (5) the relative importance of CHON and silicate dust particles as they contribute both to the dusty-gasdynamics in the inner coma (that produce the dust particle terminal velocities) and to the observed spatial morphology on the outer dust coma

Modeling the Thermodynamic Properties of the Inner Comae of Comets

Science.gov (United States)

Boice, Daniel C.

2017-10-01

Introduction: Modeling is central to understand the important properties of the cometary environment. We have developed a comet model, SUISEI, that self-consistently includes the relevant physicochemical processes within a global modeling framework, from the porous subsurface layers of the nucleus to the interaction with the solar wind. Our goal is to gain valuable insights into the intrinsic properties of cometary nuclei so we can better understand observations and in situ measurements. SUISEI includes a multifluid, reactive gas dynamics simulation of the dusty coma (ComChem) and a suite of other coupled numerical simulations. This model has been successfully applied to a variety of comets in previous studies over the past three decades. We present results from a quantitative study of the thermodynamic properties and chemistry of cometary comae as a function of cometocentric and heliocentric distance to aid in interpretation of observations and in situ measurements of comets.Results and Discussion: ComChem solves the fluid dynamic equations for the mass, momentum, and energy of three neutral fluids (H, H2, and the heavier bulk fluid), ions, and electrons. In the inner coma, the gas expands, cools, accelerates, and undergoes many photolytic and gas-phase chemical reactions tracking hundreds of sibling species. The code handles the transition to free molecular flow and describes the spatial distribution of species in the coma of a comet. Variations of neutral gas temperature and velocity with cometocentric distance and heliocentric distance for a comet approaching the Sun from 2.5 to 0.3 AU are presented. Large increases in the gas temperatures (>400 K) due to photolytic heating in the coma within ~0.5 AU are noted, with dramatic effects on the chemistry, optical depth, and other coma properties. Results are compared to observations when available.Conclusions: SUISEI has proven to be a unique and valuable model to understand the relevant physical processes and

Spatial variation in automated burst suppression detection in pharmacologically induced coma.

Science.gov (United States)

An, Jingzhi; Jonnalagadda, Durga; Moura, Valdery; Purdon, Patrick L; Brown, Emery N; Westover, M Brandon

2015-01-01

Burst suppression is actively studied as a control signal to guide anesthetic dosing in patients undergoing medically induced coma. The ability to automatically identify periods of EEG suppression and compactly summarize the depth of coma using the burst suppression probability (BSP) is crucial to effective and safe monitoring and control of medical coma. Current literature however does not explicitly account for the potential variation in burst suppression parameters across different scalp locations. In this study we analyzed standard 19-channel EEG recordings from 8 patients with refractory status epilepticus who underwent pharmacologically induced burst suppression as medical treatment for refractory seizures. We found that although burst suppression is generally considered a global phenomenon, BSP obtained using a previously validated algorithm varies systematically across different channels. A global representation of information from individual channels is proposed that takes into account the burst suppression characteristics recorded at multiple electrodes. BSP computed from this representative burst suppression pattern may be more resilient to noise and a better representation of the brain state of patients. Multichannel data integration may enhance the reliability of estimates of the depth of medical coma.

Molecular distribution in the comae of H2O-comets: an analytic model

International Nuclear Information System (INIS)

Yamamoto, T.

1981-01-01

Density distribution in cometary comae resulting from photodissociation, ionization and ion-molecule reaction of H 2 O is investigated in an analytic manner. It is assumed that particles expand isotropically around the nucleus, and that each species has its own constant radial velocity. Formulae for the density distribution of photochemical products are presented throughout the coma, and approximate formulae are given for the distribution of ion-molecule reaction products in the inner coma. Characteristics of the density profile are discussed on the basis of these analytic formulae. (Auth.)

The effect of brain death and coma on gastric myoelectrical activity.

Science.gov (United States)

Bor, Canan; Bordin, Dmitry; Demirag, Kubilay; Uyar, Mehmet

2016-05-01

Gastrointestinal motility problems and delayed gastric emptying in patients admitted to intensive care units are important because they can contribute to different problems. Herein we aimed to measure the changes in gastric myoelectrical activity with electrogastrography (EGG) following brain death (BD) and compare the results to those from patients in a deep coma without BD. Fifteen patients with BD and nine in a deep coma with a Glasgow Coma Score from 3 to 8 were included. An enteral nutrition solution was given via a nasogastric tube between 45 min of fasting and the postprandial periods. The mean dominant frequency (MnDF), normal gastric slow wave ratio (%), tachygastria and bradygastria (%), power ratio (PR: dominant power after test meal/fasting), and dominant frequency instability coefficient were evaluated. The median of MnDF was determined 3.20±0.6 (BD) vs 3.05±0.5 (control), p>0.05. Patients with BD displayed tachygastria, particularly during the fasting state, with this disturbance decreasing during the postprandial period (from 41% to 15%). However, none of the differences between the groups were statistically significant. PR was pathologic in 4/15 (26.7%) patients in the BD group and 4/9 (44.4%) patients in the control group (p=0.288). Patients with coma or BD bouth might have gastric myoelectrical activity disturbances. BD does not show more severe disturbance than coma wihouth BD. EGG might be useful as a non-invasive and easy-to-use technology; however, it needs further improvement.

Morfología de la Coma del Cometa Hale - Bopp

Science.gov (United States)

Gil-Hutton, R.; Caballero, M.; Coldwell, G.; Cañada, M.; Godoy, G.; Trozzo, C.; Gómez, G.

Para lograr comprender plenamente los procesos físicos que se desarrollan en los núcleos cometarios y obtener un modelo que explique, no sólo su actividad, sino también sus efectos sobre la coma, es necesario obtener información detallada para el mayor número de cometas posible, siendo las características más interesantes para estudiar la ubicación de las regiones activas, la presencia de jets, las tasas de producción de gas y polvo y la interacción de la coma con el viento solar. En la actualidad, con técnicas de procesamiento de imágenes y tecnología CCD se pueden obtener este tipo de datos para cometas que ingresan al sistema solar interior y estudiar, de esta manera, la morfología de sus comas, tratando de correlacionar la actividad detectada con algún modelo teórico. En este trabajo se presenta un estudio parcial de la actividad desarrollada por el cometa Hale-Bopp, y sus efectos sobre la morfología de su coma, desde agosto de 1995 hasta la fecha en base a imágenes adquiridas con el telescopio de 0.76 m. de la Estación Astronómica Dr. Carlos Ulrrico Cesco.

Hypothyroidism and myxedema coma.

Science.gov (United States)

Finora, Kevin; Greco, Deborah

2007-01-01

Hypothyroidism is a common endocrinopathy in dogs but is rare in cats. Lymphocytic thyroiditis and idiopathic thyroid atrophy are common causes of this condition. Specific thyroid function tests, in conjunction with clinical signs and physical examination findings, are used to help confirm a diagnosis of hypothyroidism. This disease can be managed with synthetic hormone supplementation and has an excellent prognosis. Myxedema coma is a rare and potentially fatal manifestation of severe hypothyroidism that can be successfully treated using intravenous levothyroxine.

Severe oligozoospermia in a patient with myxedema coma.

Science.gov (United States)

Komiya, Akira; Watanabe, Akihiko; Kawauchi, Yoko; Takano, Atsuko; Fuse, Hideki

2012-10-01

A case of severe oligozoospermia with myxedema coma is herein presented. The patient was referred to a male infertility clinic with a 5-year history of primary infertility. Decreased serum testosterone and elevated serum prolactin without abnormal MRI findings in the hypothalamus, and decreased semen volume and sperm motility were noted. A GnRH test revealed a decreased luteinizing hormone response, whereas the HCG test showed a normal testosterone increase. Because a urinalysis after ejaculation indicated retrograde ejaculation, imipramine administration was started. However, the semen quality deteriorated, so the patient was referred to an ART clinic. Twenty-one months from the initial visit, the patient developed a loss of consciousness and edema due to myxedema coma, a life-threatening state of hypothyroidism. The patient recovered after 1 month of thyroid hormone replacement therapy (HRT) with corticosteroids. Three months after the myxedema coma, a semen analysis showed a decreased semen volume (0.2 mL) and severe oligozoospermia (two spermatozoa/ejaculate). Elevated prolactin and decreased testosterone levels were still present. These parameters gradually improved after restoration of euthyroidism by HRT. In conclusion, physicians should confirm the thyroid function in the management of male infertility, especially in patients with elevated prolactin levels.

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

Science.gov (United States)

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.

EEG as an Indicator of Cerebral Functioning in Postanoxic Coma.

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Yosuke Ono

2017-04-01

Full Text Available Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Combining Galaxy-Galaxy Lensing and Galaxy Clustering

Energy Technology Data Exchange (ETDEWEB)

Park, Youngsoo [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Krause, Elisabeth [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Dodelson, Scott [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Jain, Bhuvnesh [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Amara, Adam [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Becker, Matt [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bridle, Sarah [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Clampitt, Joseph [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Crocce, Martin [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Honscheid, Klaus [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gaztanaga, Enrique [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sanchez, Carles [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wechsler, Risa [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2015-01-01

Combining galaxy-galaxy lensing and galaxy clustering is a promising method for inferring the growth rate of large scale structure, a quantity that will shed light on the mechanism driving the acceleration of the Universe. The Dark Energy Survey (DES) is a prime candidate for such an analysis, with its measurements of both the distribution of galaxies on the sky and the tangential shears of background galaxies induced by these foreground lenses. By constructing an end-to-end analysis that combines large-scale galaxy clustering and small-scale galaxy-galaxy lensing, we also forecast the potential of a combined probes analysis on DES datasets. In particular, we develop a practical approach to a DES combined probes analysis by jointly modeling the assumptions and systematics affecting the different components of the data vector, employing a shared halo model, HOD parametrization, photometric redshift errors, and shear measurement errors. Furthermore, we study the effect of external priors on different subsets of these parameters. We conclude that DES data will provide powerful constraints on the evolution of structure growth in the universe, conservatively/ optimistically constraining the growth function to 8%/4.9% with its first-year data covering 1000 square degrees, and to 4%/2.3% with its full five-year data covering 5000 square degrees.

Hyperosmolar Hyperglycemic Non Ketotic Coma and ...

African Journals Online (AJOL)

Recognition of this association will enable better management of the patient and reduce the burden on the care taker by preventing the onset of complications that can prove fatal. It is also important to realise that hyperosmolar coma can be the presenting complaint of a diabetic seeking medical attention for the first time.

Evaluation of the protein metabolism during hepatic coma evidenced by 15N tracer data

International Nuclear Information System (INIS)

Matkowitz, R.; Hartig, W.; Junghans, P.; Jung, K.; Hirschberg, K.; Bornhak, H.

1983-01-01

In patients in coma hepaticum as well as in pigs with experimental hepatic coma the protein metabolism was studied under conditions of parenteral application of an amino acid diet using 15 N-glycine as tracer

THERMODYNAMICS OF THE COMA CLUSTER OUTSKIRTS

International Nuclear Information System (INIS)

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

2013-01-01

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

Solar wind effects on the outer ion coma of Comet Halley

International Nuclear Information System (INIS)

Flammer, K.R.

1987-01-01

A simple two-dimensional model is developed to examine the composition of the cometary ion coma in the region outside the ionopause which is strongly affected by the solar wind. Two-dimensional ion distributions are obtained assuming a cylindrically symmetric ion coma which accounts for the dynamic effects of the mass-loaded solar wind flow around the cometary ionosphere. The results of this model are discussed in the context of analyzing the GIOTTO ion data

Soft x-ray emission from the direction of the Coma cluster

International Nuclear Information System (INIS)

Hayakawa, Satio; Tanaka, Yasuo; Yamashita, Koujun; Bleeker, J.A.M.; Deerenberg, A.J.M.

1975-01-01

A soft X-ray source was observed in the direction of the Coma cluster. The flux in the energy range 0.2--0.4 keV was found to change within a time scale shorter than 80 s. The fast transient and the energy spectrum prohibit identification of this source with the Coma cluster. It is suggested that this source belongs to a class of nearby transient soft X-ray sources. (auth.)

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Jet morphology and coma analysis of comet 103P/Hartley 2

Science.gov (United States)

Vaughan, Charles M.

In 2010, comet 103P/Hartley 2 was observed pre- and post-perihelion using the George and Cynthia Mitchell Integral Field Spectrometer on the 2.7-m telescope at McDonald Observatory in Texas. Data for gaseous radicals C2, C3, CH, CN, and NH2 were collected over six nights from 15 July to 10 November. The spectral data were used to create coma maps for each of the observed species, and the maps were processed using radial and azimuthal mean division techniques to create enhanced images of the coma, revealing subtle morphological features. 340 enhanced coma images were created for each observation and species. Visual inspection reveals that the coma is heterogeneous between the five detected radicals, and statistical analyses verify this result. To compliment the ongoing investigation of Hartley 2 as studied by the EPOXI flyby mission, findings from other researchers (Belton et al., 2012; Syal et al., 2012; and Thomas et al., 2012) are used to characterize the nucleus spin state and identify dust jet locations on the nucleus. With rotational period measurements from EPOXI, dust jet vectors on the nucleus surface are rotated to relevant observation times in November to compare the computed jet directions with the radical densities in the coma. Dust jet sites on the smaller nucleus lobe show a stronger correlation with high radical concentrations than the dust sites on the larger nucleus lobe. Production rates for potential parentage of radical species are calculated using the radial outflow Haser model (Haser, 1957), which are compared to mixing ratios relative to water from separate campaigns to constrain parentage. NH3 is likely the sole producer of NH2, whereas CN may be produced from a combination of HCN, C2N2, and CH3CN. Traditional parentage of C2, C3, and CH do not yield acceptable fits or suitable mixing ratios with the Haser model, and it is possible that extended coma ices having relatively short scale lengths greatly contribute to production of these

Is the Comma cluster a zel'dovich disk

International Nuclear Information System (INIS)

Thompson, L.A.; Gregory, S.A.

1978-01-01

The two-dimensional structure of the Coma cluster is analyzed with the use of galaxies from a wide-area redshift survey. Since redshift observations allow us to sort cluster galaxies from foreground and background galaxies, we can accurately trace the cluster structure to large radii. The following results have been obtained: (1) The center of mass of the Coma cluster is coincident with NGC 4874, the brightest S0 (or cD) galaxy. (2) The cluster has an elliptical shape with axis ratio-0.55 and position angle 67 0 . (3) There is a sharp falloff in the distribution of bright galaxies at a radius ab)/sup 1/2/=rapprox. =3.1. (4) The radial distribution of galaxies contains a slight secondary maximum at a radius (ab) 12 =rapprox. =1 0 .4. The observations are used to show that the cluster may be composed of two components, a central spherical core plus a more widely idspersed flattened disk. We suggest that the observed structure of Coma can be consistently explained using the model of Doroshkevich, Sunyaev, and Zel'kovich which involves the formation of massive protoclusters prior to the epoch of galaxy formation

[Myxedema coma as a rare differential diagnosis of severe consciousness disturbance].

Science.gov (United States)

Kollmar, R; Schellinger, P D; Bardutzky, J; Meisel, F; Schwaninger, M

2002-12-01

Myxedema coma is a rare and life-threatening complication of untreated hypothyroidism. Therefore, it must be part of the differential diagnosis in comatose patients. We report one patient who presented with CO(2) narcosis,hypothermia, bradycardia,hyporeflexia, tetraparesis, ascitis, pleural effusions, and heart insufficiency. Examination of the CSF, cranial CT, MRI, and MR angiography were normal. In suspicion of myxedema coma,the patient was treated with high dose L-thyroxine and hydrocortisone for preventing secondary adrenal insufficiency. A fast clinical recovery, decreased T4 (7.2 ng/l) and T3 (0.93 ng/l), and increased TSH (20.19 mU/l) together with the following anamnesis of radio iodine therapy and insufficient thyroxine intake confirmed the diagnosis. In conclusion, treatment of the myxedema coma must be started as soon as the laboratory results are confirmatory, since its course depends on the time of initiation of treatment.

The Blue Coma: The Role of Methylene Blue in Unexplained Coma After Cardiac Surgery.

Science.gov (United States)

Martino, Enrico Antonio; Winterton, Dario; Nardelli, Pasquale; Pasin, Laura; Calabrò, Maria Grazia; Bove, Tiziana; Fanelli, Giovanna; Zangrillo, Alberto; Landoni, Giovanni

2016-04-01

Methylene blue commonly is used as a dye or an antidote, but also can be used off label as a vasopressor. Serotonin toxicity is a potentially lethal and often misdiagnosed condition that can result from drug interaction. Mild serotonin toxicity previously was reported in settings in which methylene blue was used as a dye. The authors report 3 cases of life-threatening serotonin toxicity in patients undergoing chronic selective serotonin reuptake inhibitor (SSRI) therapy who also underwent cardiac surgery and received methylene blue to treat vasoplegic syndrome. An observational study. A cardiothoracic intensive care unit (ICU) in a teaching hospital. Three patients who received methylene blue after cardiac surgery, later discovered to be undergoing chronic SSRI therapy. None. All 3 patients received high doses of fentanyl during general anesthesia. They all developed vasoplegic syndrome and consequently were given methylene blue in the ICU. All 3 patients developed serotonin toxicity, including coma, after this administration and diagnostic tests were negative for acute intracranial pathology. Coma lasted between 1 and 5 days. Two patients were discharged from the ICU shortly after awakening, whereas the third patient experienced a complicated postoperative course for concomitant refractory low-cardiac-output syndrome. Patients undergoing chronic SSRI therapy should not be administered methylene blue to treat vasoplegic syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

Hall effect in the coma of 67P/Churyumov-Gerasimenko

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Huang, Z.; Tóth, G.; Gombosi, T. I.; Jia, X.; Combi, M. R.; Hansen, K. C.; Fougere, N.; Shou, Y.; Tenishev, V.; Altwegg, K.; Rubin, M.

2018-04-01

Magnetohydrodynamics simulations have been carried out in studying the solar wind and cometary plasma interactions for decades. Various plasma boundaries have been simulated and compared well with observations for comet 1P/Halley. The Rosetta mission, which studies comet 67P/Churyumov-Gerasimenko, challenges our understanding of the solar wind and comet interactions. The Rosetta Plasma Consortium observed regions of very weak magnetic field outside the predicted diamagnetic cavity. In this paper, we simulate the inner coma with the Hall magnetohydrodynamics equations and show that the Hall effect is important in the inner coma environment. The magnetic field topology becomes complex and magnetic reconnection occurs on the dayside when the Hall effect is taken into account. The magnetic reconnection on the dayside can generate weak magnetic field regions outside the global diamagnetic cavity, which may explain the Rosetta Plasma Consortium observations. We conclude that the substantial change in the inner coma environment is due to the fact that the ion inertial length (or gyro radius) is not much smaller than the size of the diamagnetic cavity.

Model of comet comae. II. Effects of solar photodissociative ionization

International Nuclear Information System (INIS)

Huebner, W.F.; Giguere, P.T.

1980-01-01

Improvements to our computer model of coma plotochemistry are described. These include an expansion of the chemical reactions network and new rate constants that have been measured only recently. Photolytic reactions of additional molecules are incorporated, and photolytic branching ratios are treated in far greater detail than in our previous work. A total of 25 photodissociative ionization (PDI) reactions are now considered (as compared to only 3 PDI reactions previously). Solar PDI of the mother molecule CO 2 is shown to compete effectively with photoionization of CO in the production of observed CO + . The CO + density peak predicted by our improved model, for COP 2 or CO mother molecules, is deep in the inner coma, in better agreement with observation than our old CO 2 model. However, neither CO 2 nor CO mother molecule calculations reproduce the CO + /H 2 O + ratio observed in comet Kohoutek. PDI products of CO 2 , CO, CH 4 , and NH 3 mother molecules fuel a complex chemistry scheme, producing inner coma abundances of CN, C 2 , and C 3 much greater than previously calculated

Deficiency of normal galaxies among Markaryan galaxies

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Iyeveer, M.M.

1986-01-01

Comparison of the morphological types of Markaryan galaxies and other galaxies in the Uppsala catalog indicates a strong deficiency of normal ellipticals among the Markaryan galaxies, for which the fraction of type E galaxies is ≤ 1% against 10% among the remaining galaxies. Among the Markaryan galaxies, an excess of barred galaxies is observed - among the Markaryan galaxies with types Sa-Scd, approximately half or more have bars, whereas among the remaining galaxies of the same types bars are found in about 1/3

Assessment of refractive astigmatism and simulated therapeutic refractive surgery strategies in coma-like-aberrations-dominant corneal optics.

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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.

Properties of the Nucleus, Dust Coma, and Gas Coma of Comet 29P/Schwassmann-Wachmann 1 As Observed By WISE/NEOWISE

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Fernandez, Yanga R.; Bauer, J. M.; Lisse, C. M.; Grav, T.; Mainzer, A. K.; Masiero, J. R.; Walker, R. G.; Meech, K. J.

2012-10-01

We present our analysis of mid-infrared imaging of comet 29P/Schwassmann-Wachmann 1 by the Wide-field Infrared Survey Explorer (WISE) [1,2]. The comet was observed on May 3-4, 2010 - not in strong outburst - with imaging at 3.4, 4.6, 12, and 22 microns (a.k.a. bands W1, W2, W3, and W4). W1 and W2 were sensitive to the reflected-sunlight continuum and W3 and W4 to thermal emission. The comet's coma was seen in all bands, with a point-source clearly embedded in W1, W3, and W4 imaging. A coma-fitting technique [3,4] let us photometrically extract this point-source from the images, thereby letting us measure the nucleus's size, W1-band geometric albedo, and infrared beaming. The dust coma was most clearly seen at bands W1, W3, and W4, letting us estimate the dust production rate, extract spatially-resolved information about the dust albedo and color temperature, and constrain the grain composition and size distribution. W2 imaging shows a coma whose radial surface-brightness profile and photometry suggest we are seeing a gas component, specifically emission from CO and/or CO2, i.e. high-abundance species with emission lines within the bandpass. This lets us estimate 29P’s gas production rate and dust-to-gas ratio independently from earlier methods. We present a comparison of our dust, gas, and nucleus results to those from earlier studies of this comet. References: [1] E. L. Wright et al. 2010, AJ, 140, 1868. [2] A. K. Mainzer et al. 2011, ApJ, 731, 53. [3] C. M. Lisse et al. 1999, Icarus, 140, 189. [4] P. L. Lamy et al. 2004, in Comets II, pp. 223-264. Acknowledgements: This publication makes use of data products from (1) WISE, which is a joint project of UCLA and JPL/Caltech, funded by NASA; and (2) NEOWISE, which is a project of JPL/Caltech, funded by the Planetary Science Division of NASA.

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

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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.

Long-lasting functional disabilities in patients who recover from coma after cardiac operations.

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Rodriguez, Rosendo A; Nair, Shona; Bussière, Miguel; Nathan, Howard J

2013-03-01

Uncertainty regarding the long-term functional outcome of patients who awaken from coma after cardiac operations is difficult for families and physicians and may delay rehabilitation. We studied the long-term functional status of these patients to determine if duration of coma predicted outcome. We followed 71 patients who underwent cardiac operations; recovered their ability to respond to verbal commands after coma associated with postoperative stroke, encephalopathy, and/or seizures; and were discharged from the hospital. The Glasgow Outcome Scale Extended (GOSE) was used to assess functional disability 2 to 4 years after discharge. Outcomes were classified as favorable (GOSE scores 7 and 8) and unfavorable (GOSE scores 1-6). Of 71 patients identified, 39 were interviewed, 15 died, 1 refused to be interviewed, and 16 were lost to follow-up. Of the 54 patients with completed GOSE evaluations, only 15 (28%) had favorable outcomes. Among patients with unfavorable outcomes, 15 (28%) died, 14 (26%) survived with moderate disabilities, and 10 (18%) had severe disabilities. Factors associated with unfavorable outcomes were increases in duration of coma (p = 0.007), time in intensive care (p = 0.006), length of hospitalization (p = 0.004), and postoperative serum creatine kinase levels (p = 0.006). Only duration of coma was an independent predictor of unfavorable outcome (odds ratio [OR], 1.25; 95% confidence interval [CI], 1.008-1.537; p = 0.042). Patients with durations of coma greater than 4 days were more likely to have unfavorable outcomes (OR, 5.1; 95% CI, 1.3-21.3; p = 0.02). Two thirds of comatose patients who survived to discharge after cardiac operations had unfavorable long-term functional outcomes. A longer duration of unconsciousness is a predictor of unfavorable outcome. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

DETECTION OF OUTFLOWING AND EXTRAPLANAR GAS IN DISKS IN AN ASSEMBLING GALAXY CLUSTER AT z = 0.37

International Nuclear Information System (INIS)

Freeland, Emily; Tran, Kim-Vy H.; Irwin, Trevor; Giordano, Lea; Saintonge, Amélie; Gonzalez, Anthony H.; Zaritsky, Dennis; Just, Dennis

2011-01-01

We detect ionized gas characteristics indicative of winds in three disk-dominated galaxies that are members of a super-group at z = 0.37 that will merge to form a Coma-mass cluster. All three galaxies are IR luminous (L IR > 4 × 10 10 L ☉ , SFR > 8 M ☉ yr –1 ) and lie outside the X-ray cores of the galaxy groups. We find that the most IR-luminous galaxy has strong blueshifted and redshifted emission lines with velocities of ∼ ± 200 km s –1 and a third, blueshifted (∼900 km s –1 ) component. This galaxy's line widths (Hβ, [O III]λ5007, [N II], Hα) correspond to velocities of 100-1000 km s –1 . We detect extraplanar gas in two of the three galaxies with SFR >8 M ☉ yr –1 whose orientations are approximately edge-on and which have integral field unit (IFU) spaxels off the stellar disk. IFU maps reveal that the extraplanar gas extends to r h ∼ 10 kpc; [N II] and Hα line widths correspond to velocities of ∼200-400 km s –1 in the disk and decrease to ∼50-150 km s –1 above the disk. Multi-wavelength observations indicate that the emission is dominated by star formation. Including the most IR-luminous galaxy we find that 18% of supergroup members with SFR >8 M ☉ yr –1 show ionized gas characteristics indicative of outflows. This is a lower limit as showing that gas is outflowing in the remaining, moderately inclined, galaxies requires a non-trivial decoupling of contributions to the emission lines from rotational and turbulent motion. Ionized gas mass loss in these winds is ∼0.1 M ☉ yr –1 for each galaxy, although the winds are likely to entrain significantly larger amounts of mass in neutral and molecular gases.

Perioperative management of a patient with myxedema coma and septicemic shock.

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Baduni, Neha; Sinha, Sunil Kumar; Sanwal, Manoj K

2012-10-01

Myxedema coma is a life-threatening but uncommon complication of long-standing, neglected hypothyroidism. It was first reported by Ord in 1879. Till date only around 200 cases have been reported in literature. The incidence in European countries is 0.22 per million per year. No epidemiological data is available from the Indian subcontinent. We are reporting the case of an elderly lady who went into life-threatening myxedema coma along with septicemic shock, and was successfully treated with oral thyroxine.

Extreme hyperphosphatemia and hypocalcemic coma associated with phosphate enema.

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Hsu, Heng Jung; Wu, Mai-Szu

2008-01-01

Fleet enema (sodium phosphate, C.B. Fleet Co., Inc., Lynchburg, Virginia) is widely used for bowel preparation or constipation relief in the hospital and over the counter. The potential risks, including hyperphosphatemia and hypocalcemic coma should be kept in mind of primary care physician. The patients with older age, bowel obstruction, small intestinal disorders, poor gut motility, and renal disease are contraindicated or should be administered with caution. We present a patient with old age and chronic renal failure who developed severe hyperphosphatemia and hypocalcemic tetany with coma after sodium phosphate enema. We recommend the use of alternative enema preparations, such as simple tap water or saline solution enemas, which can prevent fatal complications in high risk patients.

Energy balance and photochemical processes in the inner coma

International Nuclear Information System (INIS)

Huebner, W.F.; Keady, J.J.

1982-01-01

Energy balance and multifluid flow in the coma are described. Expansion cooling, radiative cooling, photodissociative heating, chemical heating, and relative multifluid flow are the processes determining the energy budget. In the fluid dynamics, fast atomic and molecular hydrogen are considered as separate fluids with larger collision mean free paths than the cold bulk fluid that has a larger mean molecular weight. The transition from fluid flow to free molecular flow is approximated. The model predicts hydrogen and bulk fluid flow velocities in general agreement with observations. The effects of the temperature profile and the fast hydrogen flow on the chemistry in the inner coma are investigated. Results from a model approximating conditions in Halley's comet are presented

On the production of positive molecular ions in cometary comas

International Nuclear Information System (INIS)

Tarafdar, S.P.; Wickramasinghe, N.C.

1977-01-01

Positively charged molecular ions, such as H 2 O + , which have been observed in cometary comas, may be efficiently produced by the evaporation of positively charged clathrate grains of radii in the range approximately 10 -6 -10 -3 cm. Such grains may be expelled from nuclei of comets, along with gaseous molecules. Grain charging occurs via interaction with solar ultraviolet photons and/or solar wind protons. Observational data on the total quantities as well as the distributions of H 2 O and H 2 O + in cometary comas are shown to be in accord with detailed model calculations. (Auth.)

Bullous lesions, sweat gland necrosis and rhabdomyolysis in alcoholic coma

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Neelakandhan Asokan

2014-01-01

Full Text Available A 42-year-old male developed hemorrhagic bullae and erosions while in alcohol induced coma. The lesions were limited to areas of the body in prolonged contact with the ground in the comatose state. He developed rhabdomyolysis, progressing to acute renal failure (ARF. Histopathological examination of the skin showed spongiosis, intraepidermal vesicles, and necrosis of eccrine sweat glands with denudation of secretory epithelial lining cells. With supportive treatment and hemodialysis, the patient recovered in 3 weeks time. This is the first reported case of bullous lesions and sweat gland necrosis occurring in alcohol-induced coma complicated by rhabdomyolysis and ARF.

Disconnection of the Ascending Arousal System in Traumatic Coma

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Edlow, Brian L.; Haynes, Robin L.; Takahashi, Emi; Klein, Joshua P.; Cummings, Peter; Benner, Thomas; Greer, David M.; Greenberg, Steven M.; Wu, Ona; Kinney, Hannah C.; Folkerth, Rebecca D.

2013-01-01

Traumatic coma is associated with disruption of axonal pathways throughout the brain but the specific pathways involved in humans are incompletely understood. In this study, we used high angular resolution diffusion imaging (HARDI) to map the connectivity of axonal pathways that mediate the 2 critical components of consciousness – arousal and awareness – in the postmortem brain of a 62-year-old woman with acute traumatic coma and in 2 control brains. HARDI tractography guided tissue sampling in the neuropathological analysis. HARDI tractography demonstrated complete disruption of white matter pathways connecting brainstem arousal nuclei to the basal forebrain and thalamic intralaminar and reticular nuclei. In contrast, hemispheric arousal pathways connecting the thalamus and basal forebrain to the cerebral cortex were only partially disrupted, as were the cortical “awareness pathways.” Neuropathologic examination, which utilized β-amyloid precursor protein and fractin immunomarkers, revealed axonal injury in the white matter of the brainstem and cerebral hemispheres that corresponded to sites of HARDI tract disruption. Axonal injury was also present within the grey matter of the hypothalamus, thalamus, basal forebrain, and cerebral cortex. We propose that traumatic coma may be a subcortical disconnection syndrome related to the disconnection of specific brainstem arousal nuclei from the thalamus and basal forebrain. PMID:23656993

Severe congestive heart failure patient on amiodarone presenting with myxedemic coma: a case report.

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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.

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

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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/

On the universality of MOG weak field approximation at galaxy cluster scale

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Ivan De Martino

2017-07-01

Full Text Available In its weak field limit, Scalar-tensor-vector gravity theory introduces a Yukawa-correction to the gravitational potential. Such a correction depends on the two parameters, α which accounts for the modification of the gravitational constant, and μ⁎−1 which represents the scale length on which the scalar field propagates. These parameters were found to be universal when the modified gravitational potential was used to fit the galaxy rotation curves and the mass profiles of galaxy clusters, both without Dark Matter. We test the universality of these parameters using the temperature anisotropies due to the thermal Sunyaev–Zeldovich effect. In our model the intra-cluster gas is in hydrostatic equilibrium within the modified gravitational potential well and it is described by a polytropic equation of state. We predict the thermal Sunyaev–Zeldovich temperature anisotropies produced by Coma cluster, and we compare them with those obtained using the Planck 2013 Nominal maps. In our analysis, we find α and the scale length, respectively, to be consistent and to depart from their universal values. Our analysis points out that the assumption of the universality of the Yukawa-correction to the gravitational potential is ruled out at more than 3.5σ at galaxy clusters scale, while demonstrating that such a theory of gravity is capable to fit the cluster profile if the scale dependence of the gravitational potential is restored.

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

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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 coma were satisfactory. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

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

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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.

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

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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.

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

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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.

Cometary models - excitation of molecules at radio wavelengths and thermodynamics of the coma

International Nuclear Information System (INIS)

Crovisier, J.

1987-01-01

Models for molecular excitation under physical conditions of cometary atmospheres are obviously a requisite for interpreting radio spectroscopic observations of comets. A review of such models is presented. The prevailing excitation mechanism for the rotational lines of parent molecules is pumping of the fundamental vibrational bands by the solar infrared radiation field, followed by spontaneous decay; the molecular rotational population is then at fluorescence equilibrium. Another competing mechanism in the inner coma is thermal excitation by collisions. Its evaluation needs the knowledge of the coma kinetic temperature law, which up to now can only be achieved by modeling the coma thermodynamics. A review of cometary thermodynamical models is also given here, and the relations between such models and cometary molecular observations are discussed. 50 references

Therapeutic options to enhance coma arousal after traumatic brain injury: state of the art of current treatments to improve coma recovery.

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Cossu, Giulia

2014-04-01

Traumatic brain injury is a leading cause of death and disability. Optimizing the recovery from coma is a priority in seeking to improve patients' functional outcomes. Standards of care have not been established: pharmacological interventions, right median nerve and sensory stimulation, dorsal column stimulation (DCS), deep brain stimulation, transcranial magnetic stimulation, hyperbaric oxygen therapy and cell transplantation have all been utilized with contrasting results. The aim of this review is to clarify the indications for the various techniques and to guide the clinical practice towards an earlier coma arousal. A systematic bibliographic search was undertaken using the principal search engines (Pubmed, Embase, Ovid and Cochrane databases) to locate the most pertinent studies. Traumatic injury is a highly individualized process, and subsequent impairments are dependent on multiple factors: this heterogeneity influences and determines therapeutic responses to the various interventions.

Galaxies

International Nuclear Information System (INIS)

1981-01-01

Normal galaxies, radio galaxies, and Seyfert galaxies are considered. The large magellanic cloud and the great galaxy in Andromedia are highlighted. Quasars and BL lacertae objects are also discussed and a review of the spectral observations of all of these galaxies and celestial objects is presented

Burst Suppression on Processed Electroencephalography as a Predictor of Post-Coma Delirium in Mechanically Ventilated ICU Patients

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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

THE SPATIAL DISTRIBUTION OF OH AND CN RADICALS IN THE COMA OF COMET ENCKE

International Nuclear Information System (INIS)

Ihalawela, Chandrasiri A.; Pierce, Donna M.; Dorman, Garrett R.; Cochran, Anita L.

2011-01-01

Multiple potential parent species have been proposed to explain CN abundances in comet comae, but the parent has not been definitively identified for all comets. This study examines the spatial distribution of CN radicals in the coma of comet Encke and determines the likelihood that CN is a photodissociative daughter of HCN in the coma. Comet Encke is the shortest orbital period (3.3 years) comet known and also has a low dust-to-gas ratio based on optical observations. Observations of CN were obtained from 2003 October 22 to 24, using the 2.7 m telescope at McDonald Observatory. To determine the parent of CN, the classical vectorial model was modified by using a cone shape in order to reproduce Encke's highly aspherical and asymmetric coma. To test the robustness of the modified model, the spatial distribution of OH was also modeled. This also allowed us to obtain CN/OH ratios in the coma. Overall, we find the CN/OH ratio to be 0.009 ± 0.004. The results are consistent with HCN being the photodissociative parent of CN, but we cannot completely rule out other possible parents such as CH 3 CN and HC 3 N. We also found that the fan-like feature spans ∼90°, consistent with the results of Woodney et al..

Galaxies

International Nuclear Information System (INIS)

1987-01-01

The size and nature of any large-scale anisotropy in the three-dimensional distribution of galaxies is still little understood. Recent studies have indicated that large fluctuations in the matter distribution on a scale from tens up to several hundreds of megaparsecs may exist. Work at the South African Astronomical Observatory (SAAO) in recent years has made major contributions to studies of the large scale distribution of galaxies, as well as to solving the problems of the galactic and extragalactic distance scale. Other studies of galaxies undertaken at SAAO include: quasars in the fields of nearby galaxies; dwarf irregular galaxies; IRAS galaxies; Seyfert galaxies; 'hot spot' galaxies; supernovae in NGC 5128 and NGC 1559 and superclusters. 4 figs

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

Science.gov (United States)

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

Etiologies et pronostic des comas non-traumatiques de l'enfant a l ...

African Journals Online (AJOL)

Objectif. Déterminer la fréquence, le profil clinique, l'étiologie et l'évolution du coma non traumatique de l'enfant de un mois à 16 ans. Méthode. Tous les cas consécutifs de coma identifiés dans les services de pédiatrie du CHU de Lomé ont fait l'objet d'une étude prospective à partir d'une fiche d'enquête préétablie.

Globular Clusters Shine in a Galaxy Lacking Dark Matter

Science.gov (United States)

Kohler, Susanna

2018-04-01

( 9.3 billion years) population and metal-poor.Rethinking Formation TheoriesThe long-standing picture of galaxies has closely connected old, metal-poor globular clusters to the galaxies dark-matter halos. Past studies have found that the ratio between the total globular-cluster mass and the overall mass of a galaxy (i.e., all dark + baryonic matter) holds remarkably constant across galaxies its typically 3 x 10-5. This has led researchers to believe that properties of the dark-matter halo may determine globular-cluster formation.The luminosity function of the compact objects in NGC 1052DF2. The red and blue curves show the luminosity functions of globular clusters in the Milky Way and in the typical ultra-diffuse galaxies of the Coma cluster, respectively. NGC 1052DF2s globular clusters peak at a significantly higher luminosity. [Adapted from van Dokkum et al. 2018]NGC 1052DF2, with a globular-cluster mass thats 3% of the mass of the galaxy ( 1000 times the expected ratio!), defies this picture. This unusual galaxy therefore demonstrates that the usual relation between globular-cluster mass and total galaxy mass probably isnt due to a fundamental connection between the dark-matter halo and globular-cluster formation. Instead, van Dokkum and collaborators suggest, globular-cluster formation may ultimately be a baryon-driven process.As with all unexpected discoveries in astronomy, we must now determine whether NGC 1052DF2 is simply a fluke, or whether it represents a new class of object we can expect to find more of. Either way, this unusual galaxy is forcing us to rethink what we know about galaxies and the star clusters they host.CitationPieter van Dokkum et al 2018 ApJL 856 L30. doi:10.3847/2041-8213/aab60b

Why do insects enter and recover from chill coma? Low temperature and high extracellular potassium compromises muscle function in Locusta migratoria

DEFF Research Database (Denmark)

Findsen, Anders; Pedersen, Thomas Holm; Petersen, Asbjørn G

2014-01-01

When exposed to low temperatures, many insect species enter a reversible comatose state (chill coma), which is driven by a failure of neuromuscular function. Chill coma and chill coma recovery have been associated with a loss and recovery of ion-homeostasis (particularly extracellular [K......+]) and accordingly onset of chill coma has been hypothesised to result from depolarization of membrane potential caused by loss of ion-homeostasis. Here we examined whether onset of chill coma is associated with a disturbance in ion balance by examining the correlation between disruption of ion homeostasis and onset...... of chill coma in locusts exposed to cold at varying rates of cooling. Chill coma onset temperature changed maximally 1°C under different cooling rates and marked disturbances of ion homeostasis were not observed at any of the cooling rates. In a second set of experiments we used isolated tibial muscle...

Using an integral-field unit spectrograph to study radical species in cometary coma

Science.gov (United States)

Lewis, Benjamin; Pierce, Donna M.; Vaughan, Charles M.; Cochran, Anita

2015-01-01

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, CN, NH2). Various coma enhancements were used to identify and characterize coma morphological features. The azimuthal average profiles and the Haser model were used to determine production rates and possible parent molecules. Here, we present the work completed to date, and we compare our results to other comet taxonomic surveys. This work was funded by the National Science Foundation Graduate K-12 (GK-12) STEM Fellows program (Award No. DGE-0947419), NASA's Planetary Atmospheres program (Award No. NNX14AH18G), and the Fund for Astrophysical Research, Inc.

A case report on near manual strangulation and glasgow coma scale.

Science.gov (United States)

Meel Banwari, L

2015-09-01

Glasgow Coma Scale (GCS) is considered as a gold standard in estimating the prognosis of the comatose patient. The management of the patient relies heavily on this scale. The mechanism of injury must also be included in scoring of the GCS. Survival from strangulation is uncommon, and if it occurs, it is often associated with various complications such as neurological consequences. To highlight a poor correlation with low GCS and ultimate outcome in cases of manual strangulation. This is a case report of young female adult who was raped and manually strangulated by a colleague during a training course for traditional healers. She was admitted with very low (3/15) Glasgow Coma Scale (GCS) and presumed to have a poor prognosis. She was rigorously ventilated in Intensive Care Unit (ICU), and was discharged from hospital after a week without any complications. The neck and genital injuries are described. This report discusses. A low Glasgow Coma Scale is not a predictive of poor prognosis in cases of manual strangulation.

A simulation of the intracluster medium with feedback from cluster galaxies

Science.gov (United States)

Metzler, Christopher A.; Evrard, August E.

1994-01-01

We detail method and report first results from a three-dimensional hydrodynamical and N-body simulation of the formation and evolution of a Coma-sized cluster of galaxies, with the intent of studying the history of the hot, X-ray emitting intracluster medium. Cluster gas, galaxies, and dark matter are included in the model. The galaxies and dark matter fell gravitational forces; the cluster gas also undergoes hydrodynamical effects such as shock heating and PdV work. For the first time in three dimensions, we include modeling of ejection of processed gas from the simulated galaxies by winds, including heating and heavy element enrichment. For comparison, we employ a `pure infall' simulation using the same initial conditions but with no galaxies or winds. We employ an extreme ejection history for galactic feedback in order to define the boundary of likely models. As expected, feedback raises the entropy of the intracluster gas, preventing it from collapsing to densities as high as those attained in the infall model. The effect is more pronounced in subclusters formed at high redshift. The cluster with feedback is always less X-ray luminous, but experiences more rapid luminosity evolution, than the pure infall cluster. Even employing an extreme ejection model, the final gas temperature is only approximately 15% larger than in the infall model. The radial temperature profile is very nearly isothermal within 1.5 Mpc. The cluster galaxies in the feedback model have a velocity dispersion approximately 15% lower than the dark matter. This results in the true ratio of specific energies in galaxies to gas being less than one, beta(sub spec) approximately 0.7. The infall model predicts beta(sub spec) approximately 1.2. Large excursions in these values occur over time, following the complex dynamical history of the cluster. The morphology of the X-ray emission is little affected by feedback. The emission profiles of both clusters are well described by the standard beta

INTERACTIONS OF GALAXIES IN THE GALAXY CLUSTER ENVIRONMENT

International Nuclear Information System (INIS)

Park, Changbom; Hwang, Ho Seong

2009-01-01

We study the dependence of galaxy properties on the clustercentric radius and the environment attributed to the nearest neighbor galaxy using the Sloan Digital Sky Survey galaxies associated with the Abell galaxy clusters. We find that there exists a characteristic scale where the properties of galaxies suddenly start to depend on the clustercentric radius at fixed neighbor environment. The characteristic scale is 1-3 times the cluster virial radius depending on galaxy luminosity. Existence of the characteristic scale means that the local galaxy number density is not directly responsible for the morphology-density relation in clusters because the local density varies smoothly with the clustercentric radius and has no discontinuity in general. What is really working in clusters is the morphology-clustercentric radius-neighbor environment relation, where the neighbor environment means both neighbor morphology and the local mass density attributed to the neighbor. The morphology-density relation appears working only because of the statistical correlation between the nearest neighbor distance and the local galaxy number density. We find strong evidence that the hydrodynamic interactions with nearby early-type galaxies is the main drive to quenching star formation activity of late-type galaxies in clusters. The hot cluster gas seems to play at most a minor role down to one tenth of the cluster virial radius. We also find that the viable mechanisms which can account for the clustercentric radius dependence of the structural and internal kinematics parameters are harassment and interaction of galaxies with the cluster potential. The morphology transformation of the late-type galaxies in clusters seems to have taken place through both galaxy-galaxy hydrodynamic interactions and galaxy-cluster/galaxy-galaxy gravitational interactions.

INTERACTIONS OF GALAXIES IN THE GALAXY CLUSTER ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Park, Changbom; Hwang, Ho Seong [School of Physics, Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)], E-mail: cbp@kias.re.kr, E-mail: hshwang@kias.re.kr

2009-07-10

We study the dependence of galaxy properties on the clustercentric radius and the environment attributed to the nearest neighbor galaxy using the Sloan Digital Sky Survey galaxies associated with the Abell galaxy clusters. We find that there exists a characteristic scale where the properties of galaxies suddenly start to depend on the clustercentric radius at fixed neighbor environment. The characteristic scale is 1-3 times the cluster virial radius depending on galaxy luminosity. Existence of the characteristic scale means that the local galaxy number density is not directly responsible for the morphology-density relation in clusters because the local density varies smoothly with the clustercentric radius and has no discontinuity in general. What is really working in clusters is the morphology-clustercentric radius-neighbor environment relation, where the neighbor environment means both neighbor morphology and the local mass density attributed to the neighbor. The morphology-density relation appears working only because of the statistical correlation between the nearest neighbor distance and the local galaxy number density. We find strong evidence that the hydrodynamic interactions with nearby early-type galaxies is the main drive to quenching star formation activity of late-type galaxies in clusters. The hot cluster gas seems to play at most a minor role down to one tenth of the cluster virial radius. We also find that the viable mechanisms which can account for the clustercentric radius dependence of the structural and internal kinematics parameters are harassment and interaction of galaxies with the cluster potential. The morphology transformation of the late-type galaxies in clusters seems to have taken place through both galaxy-galaxy hydrodynamic interactions and galaxy-cluster/galaxy-galaxy gravitational interactions.

Particle Sizes in the Coma of Comet 45P/Honda-Mrkos-Pajdušáková from Arecibo Radar Observations

Science.gov (United States)

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.

Low-Surface-Brightness Galaxies: Hidden Galaxies Revealed

Science.gov (United States)

Bothun, G.; Impey, C.; McGaugh, S.

1997-07-01

In twenty years, low surface brightness (LSB) galaxies have evolved from being an idiosyncratic notion to being one of the major baryonic repositories in the Universe. The story of their discovery and the characterization of their properties is told here. Their recovery from the noise of the night sky background is a strong testament to the severity of surface brightness selection effects. LSB galaxies have a number of remarkable properties which distinguish them from the more familiar Hubble Sequence of spirals. The two most important are 1) they evolve at a significantly slower rate and may well experience star formation outside of the molecular cloud environment, 2) they are embedded in dark matter halos which are of lower density and more extended than the halos around high surface brightness (HSB) disk galaxies. Compared to HSB disks, LSB disks are strongly dark matter dominated at all radii and show a systematic increase in $M/L$ with decreasing central surface brightness. In addition, the recognition that large numbers of LSB galaxies actually exist has changed the form of the galaxy luminosity function and has clearly increased the space density of galaxies at z =0. Recent CCD surveys have uncovered a population of red LSB disks that may be related to the excess of faint blue galaxies detected at moderate redshifts. LSB galaxies offer us a new window into galaxy evolution and formation which is every bit as important as those processes which have produced easy to detect galaxies. Indeed, the apparent youth of some LSB galaxies suggest that galaxy formation is a greatly extended process. While the discovery of LSB galaxies have lead to new insights, it remains unwise to presume that we now have a representative sample which encompasses all galaxy types and forms. (SECTION: Invited Review Paper)

Galaxies

International Nuclear Information System (INIS)

1989-01-01

In studies of the large scale structure of the universe there is a continuing need for extensive galaxy redshift determinations. Optically selected redshift surveys are of particular importance, since flux-limited samples record much higher space densities of galaxies than samples of similar size selected in other wavebands. A considerable amount of the South African Astronomical Observatory (SAAO) observing time is currently being devoted to carrying out a large southern galaxy redshift survey. A recently completed study, the Durham-SAAO redshift survey suggests that the mean density of matter is well below the critical limit for a closed universe and also that the universe may be homogenous at very large scales. Other research conducted by the SAAO include studies on: the distribution of galaxies; Seyfert galaxies; starburst and IRAS galaxies; interacting and compact galaxies; a re-evaluation of the Cepheid distance to NGC 300, and a search for quasars behind galaxies. 1 fig

Jet Morphology and Coma Analysis of 103P/Hartley 2: Temporal Evolution and Interspecies Comparisons

Science.gov (United States)

Vaughan, Charles M.; Pierce, Donna M.; Cochran, Anita L.

2014-11-01

We present our results on an expanded study of the jet and coma behavior of comet 103P/Hartley 2 (a continuation of original results presented in Vaughan et al. 2012). We observed Hartley 2 pre- and post-perihelion in 2010 using the George and Cynthia Mitchell Spectrograph on the 2.7 m telescope at McDonald Observatory. Data for CN, C2, C3, CH, and NH2 were collected over six nights from 15 July to 10 November. The spectral data were used to create coma maps for each of the observed species, and the maps were processed using radial and azimuthal division techniques to create enhanced images of the coma to examine coma morphological features. To compliment the ongoing investigation of Hartley 2 as studied by the EPOXI flyby mission, we use findings from other researchers (Belton et al. 2012; Syal et al. 2012; Thomas et al. 2012) to identify dust jet locations on the nucleus and compare the computed jet directions to the radical densities in the coma at our observation times. We also calculate production rates and mixing ratios with water for suspected parent species. This work was funded by the National Science Foundation Graduate K-12 (GK-12) STEM Fellows program (Award No. DGE-0947419) and NASA’s Planetary Atmospheres program (Award No. NNX14AH18G).

Assessment of physicians' knowledge of Glasgow Coma Score ...

African Journals Online (AJOL)

Background: Glasgow Coma Scale (GCS) is the most commonly used tool in assessing comatose patients. It is simple, easily communicable, and useful in prognostication and determination of the treatment modality in head injury. Unfortunately, a high percentage of clinicians who are not in the emergency or neurological ...

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

Science.gov (United States)

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.

Near-UV OH Prompt Emission in the Innermost Coma of 103P/Hartley 2

Science.gov (United States)

La Forgia, Fiorangela; Bodewits, Dennis; A'Hearn, Michael F.; Protopapa, Silvia; Kelley, Michael S. P.; Sunshine, Jessica; Feaga, Lori; Farnham, Tony

2017-11-01

The Deep Impact spacecraft flyby of comet 103P/Hartley 2 occurred on 2010 November 4, 1 week after perihelion with a closest approach (CA) distance of about 700 km. We used narrowband images obtained by the Medium Resolution Imager on board the spacecraft to study the gas and dust in the innermost coma. We derived an overall dust reddening of 15%/100 nm between 345 and 749 nm and identified a blue enhancement in the dust coma in the sunward direction within 5 km from the nucleus, which we interpret as a localized enrichment in water ice. OH column density maps show an anti-sunward enhancement throughout the encounter, except for the highest-resolution images, acquired at CA, where a radial jet becomes visible in the innermost coma, extending up to 12 km from the nucleus. The OH distribution in the inner coma is very different from that expected for a fragment species. Instead, it correlates well with the water vapor map derived by the HRI-IR instrument on board Deep Impact. Radial profiles of the OH column density and derived water production rates show an excess of OH emission during CA that cannot be explained with pure fluorescence. We attribute this excess to a prompt emission process where photodissociation of H2O directly produces excited OH*(A 2Σ+) radicals. Our observations provide the first direct imaging of near-UV prompt emission of OH. We therefore suggest the use of a dedicated filter centered at 318.8 nm to directly trace the water in the coma of comets.

Negative Ion Chemistry in the Coma of Comet 1P/Halley

Science.gov (United States)

Cordiner, M. A.; Charnley, S. B.

2012-01-01

Negative ions (anions) were identified in the coma of comet 1P/Halley from in-situ measurements performed by the Giotto spacecraft in 1986. These anions were detected with masses in the range 7-110 amu, but with insufficient mass resolution to permit unambiguous identification. We present details of a new chemical-hydrodynamic model for the coma of comet Halley that includes - for the first time - atomic and molecular anions, in addition to a comprehensive hydrocarbon chemistry. Anion number densities arc calculated as a function of radius in the coma, and compared with the Giotto results. Important anion production mechanisms arc found to include radiative electron attachment, polar photodissociation, dissociative electron attachment, and proton transfer. The polyyne anions C4H(-) and C6H(-) arc found to be likely candidates to explain the Giotto anion mass spectrum in the range 49-73 amu. Thc CN(-) anion probably makes a significant contribution to the mass spectrum at 26 amu. Larger carbon-chain anions such as C8H(1) can explain the peak near 100 amu provided there is a source of large carbon-chain-bearing molecules from the cometary nucleus.

Modeling Coma Gas Jets in Comet Hale-Bopp

Science.gov (United States)

Lederer, S. M.; Campins, H.

2001-01-01

We present an analysis of OH, CN, and C2 jets observed in Comet Hale-Bopp. The relative contributions from and composition of the coma gas sources, and the parameters describing the active areas responsible for the gas jets will be discussed. Additional information is contained in the original extended abstract.

Unusual cause of coma | Jaggi | Malawi Medical Journal

African Journals Online (AJOL)

Journal Home > Vol 8, No 2 (1992) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Unusual cause of coma. P Jaggi, AD Harries. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

Galaxy collisions

International Nuclear Information System (INIS)

Combes, F.

1987-01-01

Galaxies are not isolated systems of stars and gas, ''independent universes'' as believed by astronomers about ten years ago, but galaxies are formed and evolve by interaction with their environment, and in particular with their nearest neighbors. Gravitational interactions produce enormous tides in the disk of spiral galaxies, generate spiral arms and trigger bursts of star formation. Around elliptical galaxies, the collision with a small companion produces a series of waves, or shells. A galaxy interaction leads, in most cases, to the coalescence of the two coliders; therefore all galaxies are not formed just after the Big-Bang, when matter recombines: second generation galaxies are still forming now by galaxy mergers, essentially elliptical galaxies, but also compact dwarfs. Collisions between galaxies could also trigger activity in nuclei for radiogalaxies and quasars [fr

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

Science.gov (United States)

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.

Dwarf spheroidal galaxies: Keystones of galaxy evolution

Science.gov (United States)

Gallagher, John S., III; Wyse, Rosemary F. G.

1994-01-01

Dwarf spheroidal galaxies are the most insignificant extragalactic stellar systems in terms of their visibility, but potentially very significant in terms of their role in the formation and evolution of much more luminous galaxies. We discuss the present observational data and their implications for theories of the formation and evolution of both dwarf and giant galaxies. The putative dark-matter content of these low-surface-brightness systems is of particular interest, as is their chemical evolution. Surveys for new dwarf spheroidals hidden behind the stars of our Galaxy and those which are not bound to giant galaxies may give new clues as to the origins of this unique class of galaxy.

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

Science.gov (United States)

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.

A TALE OF A RICH CLUSTER AT z ∼ 0.8 AS SEEN BY THE STAR FORMATION HISTORIES OF ITS EARLY-TYPE GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Ferré-Mateu, Anna [Subaru Telescope, Hilo, HI 96720 (United States); Sánchez-Blázquez, Patricia [Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049 Cantoblanco, Madrid (Spain); Vazdekis, Alexandre; De la Rosa, Ignacio G., E-mail: aferre@naoj.org [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

2014-12-20

We present a detailed stellar population analysis for a sample of 24 early-type galaxies (ETGs) belonging to the rich cluster RX J0152.7-1357 at z = 0.83. We have derived the age, metallicity, abundance pattern, and star formation history (SFH) for each galaxy individually to further characterize this intermediate-z reference cluster. We then study how these stellar population parameters depend on the local environment. This provides a better understanding on the formation timescales and subsequent evolution of the substructures in this cluster. We have also explored the evolutionary link between z ∼ 0.8 ETGs and those in the local universe by comparing the trends that the stellar population parameters followed with galaxy velocity dispersion at each epoch. We find that the ETGs in Coma are consistent with being the (passively evolving) descendants of the ETG population in RX J10152.7-1357. Furthermore, our results favor a downsizing picture, where the subclumps centers were formed first. These central parts contain the most massive galaxies, which formed the bulk of their stars in a short, burst-like event at high z. On the contrary, the cluster outskirts are populated with less-massive, smaller galaxies that show a wider variety of SFHs. In general, they present extended star formation episodes over cosmic time, which seems to be related to their posterior incorporation into the cluster around 4 Gyr after the initial event of formation.

A study of the reliability of the Nociception Coma Scale.

Science.gov (United States)

Riganello, F; Cortese, M D; Arcuri, F; Candelieri, A; Guglielmino, F; Dolce, G; Sannita, W G; Schnakers, C

2015-04-01

In this study, we investigated the reliability of the Nociception Coma Scale which has recently been developed to assess nociception in non-communicative, severely brain-injured patients. Prospective cross-sequential study. Semi-intensive care unit and long-term brain injury care. Forty-four patients diagnosed as being in a vegetative state (n=26) or in a minimally conscious state (n=18). Patients were assessed by two experts (rater A and rater B) on two consecutive weeks to measure inter-rater agreement and test-retest reliability. Total scores and subscores of the Nociception Coma Scale. We performed a total of 176 assessments. The inter-rater agreement was moderate for the total scores (k = 0.57) and fair to substantial for the subscores (0.33 ≤ k ≤ 0.62) on week 2. The test-retest reliability was substantial for the total scores (k = 0.66) and moderate to almost perfect for the subscores (0.53 ≤ k ≤ 0.96) for rater A. The inter-rater agreement was weaker on week 1, whereas the test-retest reliability was lower for the least experienced rater (rater B). This study provides further evidence of the psychometric qualities of the Nociception Coma Scale. Future studies should assess the impact of practical experience and background on administration and scoring of the scale. © The Author(s) 2014.

Investigation of previously derived Hyades, Coma, and M67 reddenings

International Nuclear Information System (INIS)

Taylor, B.J.

1980-01-01

New Hyades polarimetry and field star photometry have been obtained to check the Hyades reddening, which was found to be nonzero in a previous paper. The new Hyades polarimetry implies essentially zero reddening; this is also true of polarimetry published by Behr (which was incorrectly interpreted in the previous paper). Four photometric techniques which are presumed to be insensitive to blanketing are used to compare the Hyades to nearby field stars; these four techniques also yield essentially zero reddening. When all of these results are combined with others which the author has previously published and a simultaneous solution for the Hyades, Coma, and M67 reddenings is made, the results are E (B-V) =3 +- 2 (sigma) mmag, -1 +- 3 (sigma) mmag, and 46 +- 6 (sigma) mmag, respectively. No support for a nonzero Hyades reddening is offered by the new results. When the newly obtained reddenings for the Hyades, Coma, and M67 are compared with results from techniques given by Crawford and by users of the David Dunlap Observatory photometric system, no differences between the new and other reddenings are found which are larger than about 2 sigma. The author had previously found that the M67 main-sequence stars have about the same blanketing as that of Coma and less blanketing than the Hyades; this conclusion is essentially unchanged by the revised reddenings

Human Brain Activity Patterns beyond the Isoelectric Line of Extreme Deep Coma

Science.gov (United States)

Kroeger, Daniel; Florea, Bogdan; Amzica, Florin

2013-01-01

The electroencephalogram (EEG) reflects brain electrical activity. A flat (isoelectric) EEG, which is usually recorded during very deep coma, is considered to be a turning point between a living brain and a deceased brain. Therefore the isoelectric EEG constitutes, together with evidence of irreversible structural brain damage, one of the criteria for the assessment of brain death. In this study we use EEG recordings for humans on the one hand, and on the other hand double simultaneous intracellular recordings in the cortex and hippocampus, combined with EEG, in cats. They serve to demonstrate that a novel brain phenomenon is observable in both humans and animals during coma that is deeper than the one reflected by the isoelectric EEG, and that this state is characterized by brain activity generated within the hippocampal formation. This new state was induced either by medication applied to postanoxic coma (in human) or by application of high doses of anesthesia (isoflurane in animals) leading to an EEG activity of quasi-rhythmic sharp waves which henceforth we propose to call ν-complexes (Nu-complexes). Using simultaneous intracellular recordings in vivo in the cortex and hippocampus (especially in the CA3 region) we demonstrate that ν-complexes arise in the hippocampus and are subsequently transmitted to the cortex. The genesis of a hippocampal ν-complex depends upon another hippocampal activity, known as ripple activity, which is not overtly detectable at the cortical level. Based on our observations, we propose a scenario of how self-oscillations in hippocampal neurons can lead to a whole brain phenomenon during coma. PMID:24058669

Neuroimaging after coma

International Nuclear Information System (INIS)

Tshibanda, Luaba; Vanhaudenhuyse, Audrey; Soddu, Andrea; Bruno, Marie-Aurelie; Noirhomme, Quentin; Boly, Melanie; Laureys, Steven; Moonen, Gustave

2010-01-01

Following coma, some patients will recover wakefulness without signs of consciousness (only showing reflex movements, i.e., the vegetative state) or may show non-reflex movements but remain without functional communication (i.e., the minimally conscious state). Currently, there remains a high rate of misdiagnosis of the vegetative state (Schnakers et. al. BMC Neurol, 9:35, 8) and the clinical and electrophysiological markers of outcome from the vegetative and minimally conscious states remain unsatisfactory. This should incite clinicians to use multimodal assessment to detect objective signs of consciousness and validate para-clinical prognostic markers in these challenging patients. This review will focus on advanced magnetic resonance imaging (MRI) techniques such as magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI (fMRI studies in both ''activation'' and ''resting state'' conditions) that were recently introduced in the assessment of patients with chronic disorders of consciousness. (orig.)

Myxedema coma in a 74 year old man: case report and narrative review

Directory of Open Access Journals (Sweden)

Idania Teresa Mora López

2013-05-01

Full Text Available The follicular cells of the thyroid gland produce thyroxine and triiodothyronine hormones, as regulated by the thyrotropic hormone of the anterior pituitary, also called thyroid stimulating hormone. Myxedema coma is defined as profound hypothyroidism characterized by impairment of consciousness ranging from lethargy to stupor and coma, associated with hypothermia, hypoglycemia, seizures, hypotension, and manifestations of uncompensated hypothyroidism. The condition can be prevented if diagnosis of primary hypothyroidism is established and thyroid hormone replacement therapy is instituted. It is considered a medical emergency with high mortality rates, where environmental factors such as cold, severe infections and drug poisoning are important triggering factors. We report the case of a 74 year old male adult with no history of thyroid disease who was admitted to the Internal Medicine Ward of the “Enrique Cabrera” Hospital, Havana, Cuba, in December 2011, with clinical and laboratory signs of thyroid hypofunction. Myxedema coma was confirmed and patient course was untoward.

Myxedema Coma with Reversible Cardiopulmonary Failure: a Rare Entity in 21St Century.

Science.gov (United States)

Dhakal, Prajwal; Pant, Manisha; Acharya, Pranab Sharma; Dahal, Sumit; Bhatt, Vijaya Raj

2015-09-01

Myxedema coma, a rare entity in 21st century in developed nations, is a decompensated phase of hypothyroidism with high mortality rates. We describe a young woman with myxedema, who developed respiratory failure, congestive heart failure and significant pericardial effusion, some of the uncommon manifestations. Decreased cardiac contractility can result in cardiomyopathy and heart failure. As illustrated by this case, myxedema can also result in significant pericardial effusion due to increased vascular permeability. Myxedema can further be complicated by alveolar hypoventilation and respiratory failure secondary to the lack of central drive as well as respiratory muscle weakness. Prompt therapy with thyroid hormone replacement, glucocorticoid therapy, aggressive supportive care and management of the precipitating event can save lives and reverse the cardiopulmonary symptoms, as in our patient. Hence, physicians should have a high index of suspicion for myxedema coma in patients with unexplained cardiopulmonary failure. Our report is, therefore, aimed at bringing awareness about the rare but fatal manifestations of myxedema coma.

Near-UV OH Prompt Emission in the Innermost Coma of 103P/Hartley 2

Energy Technology Data Exchange (ETDEWEB)

La Forgia, Fiorangela [Department of Physics and Astronomy, University of Padova, Vicolo dellOsservatorio 3, I-35122 Padova (Italy); Bodewits, Dennis; A’Hearn, Michael F.; Protopapa, Silvia; Kelley, Michael S. P.; Sunshine, Jessica; Feaga, Lori; Farnham, Tony, E-mail: fiorangela.laforgia@unipd.it [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

2017-11-01

The Deep Impact spacecraft flyby of comet 103P/Hartley 2 occurred on 2010 November 4, 1 week after perihelion with a closest approach (CA) distance of about 700 km. We used narrowband images obtained by the Medium Resolution Imager on board the spacecraft to study the gas and dust in the innermost coma. We derived an overall dust reddening of 15%/100 nm between 345 and 749 nm and identified a blue enhancement in the dust coma in the sunward direction within 5 km from the nucleus, which we interpret as a localized enrichment in water ice. OH column density maps show an anti-sunward enhancement throughout the encounter, except for the highest-resolution images, acquired at CA, where a radial jet becomes visible in the innermost coma, extending up to 12 km from the nucleus. The OH distribution in the inner coma is very different from that expected for a fragment species. Instead, it correlates well with the water vapor map derived by the HRI-IR instrument on board Deep Impact . Radial profiles of the OH column density and derived water production rates show an excess of OH emission during CA that cannot be explained with pure fluorescence. We attribute this excess to a prompt emission process where photodissociation of H{sub 2}O directly produces excited OH*( A {sup 2}Σ{sup +}) radicals. Our observations provide the first direct imaging of near-UV prompt emission of OH. We therefore suggest the use of a dedicated filter centered at 318.8 nm to directly trace the water in the coma of comets.

Near-UV OH Prompt Emission in the Innermost Coma of 103P/Hartley 2

International Nuclear Information System (INIS)

La Forgia, Fiorangela; Bodewits, Dennis; A’Hearn, Michael F.; Protopapa, Silvia; Kelley, Michael S. P.; Sunshine, Jessica; Feaga, Lori; Farnham, Tony

2017-01-01

The Deep Impact spacecraft flyby of comet 103P/Hartley 2 occurred on 2010 November 4, 1 week after perihelion with a closest approach (CA) distance of about 700 km. We used narrowband images obtained by the Medium Resolution Imager on board the spacecraft to study the gas and dust in the innermost coma. We derived an overall dust reddening of 15%/100 nm between 345 and 749 nm and identified a blue enhancement in the dust coma in the sunward direction within 5 km from the nucleus, which we interpret as a localized enrichment in water ice. OH column density maps show an anti-sunward enhancement throughout the encounter, except for the highest-resolution images, acquired at CA, where a radial jet becomes visible in the innermost coma, extending up to 12 km from the nucleus. The OH distribution in the inner coma is very different from that expected for a fragment species. Instead, it correlates well with the water vapor map derived by the HRI-IR instrument on board Deep Impact . Radial profiles of the OH column density and derived water production rates show an excess of OH emission during CA that cannot be explained with pure fluorescence. We attribute this excess to a prompt emission process where photodissociation of H 2 O directly produces excited OH*( A 2 Σ + ) radicals. Our observations provide the first direct imaging of near-UV prompt emission of OH. We therefore suggest the use of a dedicated filter centered at 318.8 nm to directly trace the water in the coma of comets.

Which clinical variable influences health-related quality of life the most after spontaneous subarachnoid hemorrhage? Hunt and Hess scale, Fisher score, World Federation of Neurosurgeons score, Brussels coma score, and Glasgow coma score compared.

Science.gov (United States)

Kapapa, Thomas; Tjahjadi, Martin; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

2013-12-01

To determine the strength of the correlation between the Hunt and Hess scale, Fisher score, Brussels coma score, World Federation of Neurosurgeons score, and Glasgow coma score and health-related quality of life. Evaluable questionnaires from 236 patients (5.6 years [± standard deviation, 2.854 years] on average after hemorrhage) were included in the analysis. Quality of life was documented using the MOS-36 item short form health survey. Because of the ordinal nature of the variables, Kendall tau was used for calculation. Significance was established as P ≤ 0.05. Weak and very weak correlations were found in general (r ≤ 0.28). The strongest correlations were found between the Glasgow coma score and quality of life (r = 0.236, P = 0.0001). In particular, the "best verbal response" achieved the strongest correlations in the comparison, at r = 0.28/P = 0.0001. The Fisher score showed very weak correlations (r = -0.148/P = 0.012). The Brussels coma score (r = -0.216/P = 0.0001), Hunt and Hess scale (r = -0.197/P = 0.0001), and the World Federation of Neurosurgeons score (r = -0.185/P = 0.0001) revealed stronger correlations, especially in terms of the physical aspects of quality of life. The Glasgow coma scale revealed the strongest, and the Fisher score showed the weakest correlations. Thus the Fisher score, as an indicator of the severity of a hemorrhage, has little significance in terms of health-related quality of life. Copyright © 2013 Elsevier Inc. All rights reserved.

Sudden cardiac arrest as a rare presentation of myxedema coma: case report.

Science.gov (United States)

Salhan, Divya; Sapkota, Deepak; Verma, Prakash; Kandel, Saroj; Abdulfattah, Omar; Lixon, Antony; Zwenge, Deribe; Schmidt, Frances

2017-01-01

Myxedema coma is a decompensated hypothyroidism which occurs due to long-standing, undiagnosed, or untreated hypothyroidism. Untreated hypothyroidism is known to affect almost all organs including the heart. It is associated with a decrease in cardiac output, stroke volume due to decreased myocardial contractility, and an increase in systemic vascular resistance. It can cause cardiac arrhythmias and the most commonly seen conduction abnormalities are sinus bradycardia, heart block, ventricular tachycardia, and torsade de pointes. The authors report a case of an elderly man who presented with sudden cardiac arrest and myxedema coma and who was successfully revived.

THE NEXT GENERATION VIRGO CLUSTER SURVEY. XIX. TOMOGRAPHY OF MILKY WAY SUBSTRUCTURES IN THE NGVS FOOTPRINT

Energy Technology Data Exchange (ETDEWEB)

Lokhorst, Deborah; Starkenburg, Else; Navarro, Julio F. [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 1A1, Canada (Canada); McConnachie, Alan W.; Ferrarese, Laura; Côté, Patrick; Gwyn, Stephen D. J. [National Research Council, Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Liu, Chengze [Center for Astronomy and Astrophysics, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Cuillandre, Jean-Charles [CEA/IRFU/SAP, Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, Observatoire de Paris, PSL Research University, F-91191 Gif-sur-Yvette Cedex (France); Guhathakurta, Puragra, E-mail: dml@uvic.ca [Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

2016-03-10

The Next Generation Virgo Cluster Survey (NGVS) is a deep u*giz survey targeting the Virgo Cluster of galaxies at 16.5 Mpc. This survey provides high-quality photometry over an ∼100 deg{sup 2} region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo overdensity (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep u*gi imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) stars as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations (α ∼ 190°, δ ∼ −5°) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between ∼8 and 25 kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40 kpc, with a density maximum at ≃35 kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of ∼90 kpc—the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the ∼30° of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream with those predicted by leading stream models.

THE NEXT GENERATION VIRGO CLUSTER SURVEY. XIX. TOMOGRAPHY OF MILKY WAY SUBSTRUCTURES IN THE NGVS FOOTPRINT

International Nuclear Information System (INIS)

Lokhorst, Deborah; Starkenburg, Else; Navarro, Julio F.; McConnachie, Alan W.; Ferrarese, Laura; Côté, Patrick; Gwyn, Stephen D. J.; Liu, Chengze; Peng, Eric W.; Cuillandre, Jean-Charles; Guhathakurta, Puragra

2016-01-01

The Next Generation Virgo Cluster Survey (NGVS) is a deep u*giz survey targeting the Virgo Cluster of galaxies at 16.5 Mpc. This survey provides high-quality photometry over an ∼100 deg 2 region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo overdensity (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep u*gi imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) stars as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations (α ∼ 190°, δ ∼ −5°) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between ∼8 and 25 kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40 kpc, with a density maximum at ≃35 kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of ∼90 kpc—the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the ∼30° of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream with those predicted by leading stream models

Jet Morphology and Coma Analysis of 103P/Hartley 2

Science.gov (United States)

Vaughan, Charles; Pierce, D.; Dorman, G.; Cochran, A.

2012-10-01

We have observed comet 103P/Hartley 2 using the George and Cynthia Mitchell Spectrograph (formerly VIRUS-P) on the 2.7 m telescope at McDonald Observatory (Hill et al. 2008). Data for CN, C2, C3, and NH2 were collected over six nights from 2010 July 15 to November 10. The data were processed to form images of the coma for each of the observed species. We have performed azimuthal average division on each of the coma images to examine jet morphology and have investigated the nature of the production of the radical species using our modified vectorial model (Ihalawela et al. 2011). This work enhances the ongoing investigation of the chemistry and outgassing behavior of Hartley 2 as studied by the EPOXI flyby mission.

Spontaneous intraparenchymal otogenic pneumocephalus presenting with abrupt onset of coma

International Nuclear Information System (INIS)

Scuotto, A.; Cappabianca, S.; Capasso, R.; Natale, M.; D'Oria, S.; Rotondo, M.

2016-01-01

We report a case of spontaneous otogenic pneumocephalus, manifesting with a rapid deterioration of consciousness level. A 37-year-old man presented a 3-days history of headache and fluctuant confusion. On admission the patient was neurologically intact except for temporo-spatial disorientation. Brain Computed Tomography (CT) scan showed a large air collection in the left temporal lobe, causing mass effect. Hyperpneumatisation of mastoid air cells was also noticed. Because of the abrupt onset of coma (Glasgow Coma Scale = 10), emergency surgical evacuation of tensive pneumocephalus was carried out. Postoperatively, the patient quickly regained a good level of consciousness and was headache-free. - Highlights: • Spontaneous otogenic pneumocephalus generally presents with subtle symptoms. • Sudden consciousness involvement is a rare onset condition. • Hyperpneumatisation of the petrous bone is a predisposing factor.

Irreversible Coma clinicopathologic correlations in 79 observations

OpenAIRE

Jerí, F. Raúl

2014-01-01

Clinical and developmental data of 79 patients suffering from deep coma associated with isoelectric electroencephalogram for at least 24 consecutive hours are presented. The neuropathological study showed that the vast majority had ischemic lesions in the cerebral cortex hiccups field , cerebellum , striatum , thalamus and to a lesser extent , in the brain - stem . Failed to check precise relationship between the clinical manifestations of the specific nerve dysfunction and destruction of neu...

Galaxy bias from galaxy-galaxy lensing in the DES Science Verification Data

Energy Technology Data Exchange (ETDEWEB)

Prat, J.; et al.

2016-09-26

We present a measurement of galaxy-galaxy lensing around a magnitude-limited ($i_{AB} < 22.5$) sample of galaxies selected from the Dark Energy Survey Science Verification (DES-SV) data. We split these lenses into three photometric-redshift bins from 0.2 to 0.8, and determine the product of the galaxy bias $b$ and cross-correlation coefficient between the galaxy and dark matter overdensity fields $r$ in each bin, using scales above 4 Mpc/$h$ comoving, where we find the linear bias model to be valid given our current uncertainties. We compare our galaxy bias results from galaxy-galaxy lensing with those obtained from galaxy clustering (Crocce et al. 2016) and CMB lensing (Giannantonio et al. 2016) for the same sample of galaxies, and find our measurements to be in good agreement with those in Crocce et al. (2016), while, in the lowest redshift bin ($z\\sim0.3$), they show some tension with the findings in Giannantonio et al. (2016). Our results are found to be rather insensitive to a large range of systematic effects. We measure $b\\cdot r$ to be $0.87\\pm 0.11$, $1.12 \\pm 0.16$ and $1.24\\pm 0.23$, respectively for the three redshift bins of width $\\Delta z = 0.2$ in the range $0.2galaxy sample, except possibly at the lowest redshift bin ($z\\sim 0.3$), where we find $r = 0.71 \\pm 0.11$ when using TPZ, and $0.83 \\pm 0.12$ with BPZ, assuming the difference between the results from the two probes can be solely attributed to the cross-correlation parameter.

Polar ring galaxies in the Galaxy Zoo

Science.gov (United States)

Finkelman, Ido; Funes, José G.; Brosch, Noah

2012-05-01

We report observations of 16 candidate polar-ring galaxies (PRGs) identified by the Galaxy Zoo project in the Sloan Digital Sky Survey (SDSS) data base. Deep images of five galaxies are available in the SDSS Stripe82 data base, while to reach similar depth we observed the remaining galaxies with the 1.8-m Vatican Advanced Technology Telescope. We derive integrated magnitudes and u-r colours for the host and ring components and show continuum-subtracted Hα+[N II] images for seven objects. We present a basic morphological and environmental analysis of the galaxies and discuss their properties in comparison with other types of early-type galaxies. Follow-up photometric and spectroscopic observations will allow a kinematic confirmation of the nature of these systems and a more detailed analysis of their stellar populations.

Optical emission line spectra of Seyfert galaxies and radio galaxies

International Nuclear Information System (INIS)

Osterbrock, D.E.

1978-01-01

Many radio galaxies have strong emission lines in their optical spectra, similar to the emission lines in the spectra of Seyfert galaxies. The range of ionization extends from [O I] and [N I] through [Ne V] and [Fe VII] to [Fe X]. The emission-line spectra of radio galaxies divide into two types, narrow-line radio galaxies whose spectra are indistinguishable from Seyfert 2 galaxies, and broad-line radio galaxies whose spectra are similar to Seyfert 1 galaxies. However on the average the broad-line radio galaxies have steeper Balmer decrements, stronger [O III] and weaker Fe II emission than the Seyfert 1 galaxies, though at least one Seyfert 1 galaxy not known to be a radio source has a spectrum very similar to typical broad-line radio galaxies. Intermediate-type Seyfert galaxies exist that show various mixtures of the Seyfert 1 and Seyfert 2 properties, and the narrow-line or Seyfert 2 property seems to be strongly correlated with radio emission. (Auth.)

Dark matter halo properties from galaxy-galaxy lensing

International Nuclear Information System (INIS)

Brimioulle, Fabrice

2013-01-01

The scientific results over the past years have shown that the Universe is by far not only composed of baryonic matter. In fact the major energy content of 72% of the Universe appears to be represented by so-called dark energy, while even from the remaining components only about one fifth is of baryonic origin, whereas 80% have to be attributed to dark matter. Originally appearing in observations of spiral galaxy rotation curves, the need for dark matter has also been verified investigating elliptical galaxies and galaxy clusters. In fact, it appears that dark matter played a major role during structure formation in the early Universe. Shortly after the Big Bang, when the matter distribution was almost homogeneous, initially very small inhomogeneities in the matter distribution formed the seeds for the gravitational collapse of the matter structures. Numerical n-body simulations, for instance, clearly indicate that the presently observable evolutionary state and complexity of the matter structure in the Universe would not have been possible without dark matter, which significantly accelerated the structure collapse due to its gravitational interaction. As dark matter does not interact electromagnetically and therefore is non-luminous but only interacts gravitationally, the gravitational lens effect provides an excellent opportunity for its detection and estimation of its amount. Weak gravitational lensing is a technique that makes use of the random orientation of the intrinsic galaxy ellipticities and thus their uniform distribution. Gravitational tidal forces introduce a coherent distortion of the background object shapes, leading to a deviation from the uniform distribution which depends on the lens galaxy properties and therefore can be used to study them. This thesis describes the galaxy-galaxy lensing analysis of 89deg 2 of optical data, observed within the CFHTLS-WIDE survey. In the framework of this thesis the data were used in order to create photometric

Two-dimensional molecular line transfer for a cometary coma

Science.gov (United States)

Szutowicz, S.

2017-09-01

In the proposed axisymmetric model of the cometary coma the gas density profile is described by an angular density function. Three methods for treating two-dimensional radiative transfer are compared: the Large Velocity Gradient (LVG) (the Sobolev method), Accelerated Lambda Iteration (ALI) and accelerated Monte Carlo (MC).

Accuracy of clinical signs, SEP, and EEG in predicting outcome of hypoxic coma: a meta-analysis.

Science.gov (United States)

Lee, Y C; Phan, T G; Jolley, D J; Castley, H C; Ingram, D A; Reutens, D C

2010-02-16

Accurate prediction of neurologic outcome after hypoxic coma is important. Previous systematic reviews have not used summary statistics to summarize and formally compare the accuracy of different prognostic tests. We therefore used summary receiver operating characteristic curve (SROC) and cluster regression methods to compare motor and pupillary responses with sensory evoked potential (SEP) and EEG in predicting outcome after hypoxic coma. We searched PubMed, MEDLINE, and Embase (1966-2007) for reports in English, German, and French and identified 25 suitable studies. An SROC was constructed for each marker (SEP, EEG, M1 and M SEP was larger than those for M1, M SEP (AUC 0.891) and that for M1 (AUC 0.786) was small (0.105, 95% confidence interval 0.023-0.187), only reaching significance on day 1 after coma onset. The use of M SEP) is marginally better than M1 at predicting outcome after hypoxic coma. However, the superiority of SEP diminishes after day 1 and when M SEP is a better marker than clinical signs.

CoMA, an instrument for the detailed in-situ analysis of collected cometary particulates

International Nuclear Information System (INIS)

Kissel, J.; Fechtig, H.; Jessberger, E.K.; Krueger, F.R.; Niemczyk, N.; Schaefer, G.; Zscheeg, H.

1988-01-01

The proposal for CoMA, a pulsed time-of-flight SIMS instrument to be flown onboard CRAF to rendezvous with a comet, had been accepted by NASA in October 1986. After several attempts it seems that funding by BMFT for the instrument pre-development phase can be obtained. Apart from that we made first essential progress in producing the primary ion pulses from an indium liquid metal ion source. Those pulses are needed to operate CoMA. (orig.)

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

Science.gov (United States)

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.

Hyperammonemic coma in a patient with late-onset OTC deficiency

Directory of Open Access Journals (Sweden)

V. D’Onofrio

2014-06-01

Full Text Available Urea Cycle Disorders ( UCD are among the most common genetic diseases of the metabolism and ornithine transcarbamylase deficiency (OTC, an X-linked defect is the most frequent among them. It is responsible for hyperammonemia that can lead to chronic neurological illness and potentially to death in case of delayed diagnosis and treatment. With regards to the OTC deficiency there is great clinical heterogeneity with early-onset phenotypes with mostly poor prognosis and late-onset phenotypes with a better one. In the article it is reported the case of a 8 years old patient with diagnosis of OTC deficit with late-onset phenotype. The kid was brought to our hospital because of continuous vomiting and gastro- intestinal disorders, associated with irritability and lethargy later resulted into coma. Measurement of plasma ammonia concentration, followed by measurement of plasma amino acid and urine orotic acid levels allowed to diagnose the OTC deficit, lately confirmed by molecular genetic studies. The patient has been promptly treated with Sodium Phenylbutyrate, Arginine and discontinuing the protein intake. Gradually the ammonemia value decreased, and general and neurological conditions improved with resolution of the coma. To conclude, for patients presenting unexplained neurological symptoms, confusion and decreased level of consciousness, up to coma, urea cycle disorders and in particularly OTC deficiency should be considered in the differential diagnosis and an urgent ammonia level determined. In case of hyperammonemia, the treatment should be started immediately , even without a precise ethiologic diagnosis.

Carotid artery aneurysm resulting in myxedema coma

Directory of Open Access Journals (Sweden)

Elizabeth M. Lamos

2015-06-01

Full Text Available Intra-sellar aneurysms are a rare, but important consideration when evaluating pituitary masses. Identification of aneurysms is critical to appropriate treatment and avoiding perilous consequences. These vascular aneurysms can result in severe endocrine dysfunction due to mass effect, stripping of the vascular supply to the pituitary, or hemorrhage. Here we describe a novel case of spontaneous myxedema coma and pituitary apoplexy secondary to a large internal carotid artery aneurysm.

Isolated galaxies, pairs, and groups of galaxies

International Nuclear Information System (INIS)

Kuneva, I.; Kalinkov, M.

1990-01-01

The authors searched for isolated galaxies, pairs and groups of galaxies in the CfA survey (Huchra et al. 1983). It was assumed that the distances to galaxies are given by R = V/H sub o, where H sub o = 100 km s(exp -1) Mpc(exp -1) and R greater than 6 Mpc. The searching procedure is close to those, applied to find superclusters of galaxies (Kalinkov and Kuneva 1985, 1986). A sphere with fixed radius r (asterisk) is described around each galaxy. The mean spatial density in the sphere is m. Let G 1 be any galaxy and G 2 be its nearest neighbor at a distance R 2 . If R sub 2 exceeds the 95 percent quintile in the distribution of the distances of the second neighbors, then G 1 is an isolated galaxy. Let the midpoint of G 1 and G 2 be O 2 and r 2 =R 2 2. For the volume V 2 , defined with the radius r 2 , the density D 2 less than k mu, the galaxy G 2 is a single one and the procedure for searching for pairs and groups, beginning with this object is over and we have to pass to another object. Here the authors present the groups - isolated and nonisolated - with n greater than 3, found in the CfA survey in the Northern galactic hemisphere. The parameters used are k = 10 and r (asterisk) = 5 Mpc. Table 1 contains: (1) the group number, (2) the galaxy, nearest to the multiplet center, (3) multiplicity n, (4) the brightest galaxy if it is not listed in (2); (5) and (6) are R.A. and Dec. (1950), (7) - mean distance D in Mpc. Further there are the mean density rho (8) of the multiplet (galaxies Mpc (exp -3)), (9) the density rho (asterisk) for r (asterisk) = 5 Mpc and (10) the density rho sub g for the group with its nearest neighbor. The parenthesized digits for densities in the last three columns are powers of ten

Hyperosmolar non-ketotic diabetic coma as a cause of emergency ...

African Journals Online (AJOL)

Five of the known diabetic patients had defaulted from treatment (2 deaths). .... volume and type of fluid used in the treatment of HNKC and the final outcome; it ... Krentz AJ, Nattrass M. Diabetic ketoacidosis, non-ketotic hyperosmolar coma and.

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

OpenAIRE

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

2017-01-01

Background: 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. Methods: 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 myxedem...

Galaxy Formation

DEFF Research Database (Denmark)

Sparre, Martin

Galaxy formation is an enormously complex discipline due to the many physical processes that play a role in shaping galaxies. The objective of this thesis is to study galaxy formation with two different approaches: First, numerical simulations are used to study the structure of dark matter and how...... galaxies form stars throughout the history of the Universe, and secondly it is shown that observations of gamma-ray bursts (GRBs) can be used to probe galaxies with active star formation in the early Universe. A conclusion from the hydrodynamical simulations is that the galaxies from the stateof...... is important, since it helps constraining chemical evolution models at high redshift. A new project studying how the population of galaxies hosting GRBs relate to other galaxy population is outlined in the conclusion of this thesis. The core of this project will be to quantify how the stellar mass function...

Hyperosmolar non-ketotic diabetic coma as a cause of emergency ...

African Journals Online (AJOL)

%) while 16 admissions (12%) were as a result of hyperosmolar non-ketotic coma (HNKC), defined as hyperglycaemia, dehydration and an altered level of consciousness with a plasma osmolality ≥ 330 and an arterial pH ≥ 7,30, with absent ...

Galaxy Zoo: dust in spiral galaxies

Science.gov (United States)

Masters, Karen L.; Nichol, Robert; Bamford, Steven; Mosleh, Moein; Lintott, Chris J.; Andreescu, Dan; Edmondson, Edward M.; Keel, William C.; Murray, Phil; Raddick, M. Jordan; Schawinski, Kevin; Slosar, Anže; Szalay, Alexander S.; Thomas, Daniel; Vandenberg, Jan

2010-05-01

We investigate the effect of dust on spiral galaxies by measuring the inclination dependence of optical colours for 24276 well-resolved Sloan Digital Sky Survey (SDSS) galaxies visually classified via the Galaxy Zoo project. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4mag for the ugri passbands (estimating 0.3mag of extinction in z band). We split the sample into `bulgy' (early-type) and `discy' (late-type) spirals using the SDSS fracdeV (or fDeV) parameter and show that the average face-on colour of `bulgy' spirals is redder than the average edge-on colour of `discy' spirals. This shows that the observed optical colour of a spiral galaxy is determined almost equally by the spiral type (via the bulge-disc ratio and stellar populations), and reddening due to dust. We find that both luminosity and spiral type affect the total amount of extinction, with discy spirals at Mr ~ -21.5mag having the most reddening - more than twice as much as both the lowest luminosity and most massive, bulge-dominated spirals. An increase in dust content is well known for more luminous galaxies, but the decrease of the trend for the most luminous has not been observed before and may be related to their lower levels of recent star formation. We compare our results with the latest dust attenuation models of Tuffs et al. We find that the model reproduces the observed trends reasonably well but overpredicts the amount of u-band attenuation in edge-on galaxies. This could be an inadequacy in the Milky Way extinction law (when applied to external galaxies), but more likely indicates the need for a wider range of dust-star geometries. We end by discussing the effects of dust on large galaxy surveys and emphasize that these effects will become important as we push to higher precision measurements of galaxy properties and their clustering. This publication has been made possible by the participation of more than

Isolated galaxies

International Nuclear Information System (INIS)

Einasto, Maret

1990-01-01

To test for the possible presence of really isolated galaxies, which form a randomly distributed population in voids, we compare the distribution of most isolated galaxies in an observed sample with distributions of the same number of random points using the nearest neighbour test. The results show that the random population of really isolated galaxies does not exist - even the most isolated galaxies are connected with systems of galaxies, forming their outlying parts. (author)

A percepção auditiva nos pacientes em estado de coma: uma revisão bibliográfica La percepción auditiva en los pacientes en estado de coma: una revisión bibliográfica The auditory perception in the patients in state of coma: a bibliographical revision

Directory of Open Access Journals (Sweden)

Ana Cláudia Giesbrecht Puggina

2005-09-01

Full Text Available Muito ainda precisa ser estudado pela neurociência, tanto em relação aos estados de consciência quanto aos processos cognitivos e a percepção auditiva nos estados de coma. Assim, esse estudo de revisão bibliográfica sobre a percepção auditiva dos pacientes em estado de coma parece ser relevante no sentido de trazer maiores esclarecimentos e identificação de evidências. Identificar, nas publicações, as lacunas, consistências e inconsistências desse tema. O estudo consiste em levantamento bibliográfico nas bases de dados LILACS e PUBMED. Os artigos foram analisados quanto ao método e os principais resultados do estudo. Foram selecionados 10 artigos sobre o tema, sendo nenhum deles nacional. A maior parte dos estudos selecionados foi publicada no período de 1971-1995 (80%, pelos Estados Unidos (70%, como pesquisa longitudinal (50% ou relato de caso (30%; a amostra variou entre 1 e 5 (70%, a maioria usou a música (80%; o EEG (60% e a observação comportamental (50% foram as medidas de resposta ao estímulo mais utilizadas. Os procedimentos foram variados, porém a maioria dos estudos, apontam para a existência de uma percepção auditiva nos pacientes em estado de coma.Mucho aún se hace necesario a ser estudiado por la neurociencia, tanto en relación a los estados de conciencia cuanto a los procesos cognitivos y la percepción auditiva en lo estado de coma. Así, este estudio de revisión bibliográfica sobre la percepción auditiva de los pacientes en estado de coma parece ser relevante para traer mayores esclarecimientos e identificar las evidencias. Identificar, en las publicaciones encuentradas, las lacunas, las consistencias y las inconsistencias de este tema. Este estudo consistió en un levantamiento bibliográfico en las bases de datos LILACS y PUBMED. Para esto, los artículos fueron analizados de acuerdo con el método y los resultados principales del estudo. Fueron seleccionados 10 artículos sobre el tema

Coma Morphology Due to an Extended Active Region and Implications for the Spin State of Comet Hale-Bopp

Science.gov (United States)

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 case of myxedema coma presenting as a brain stem infarct in a 74-year-old Korean woman.

Science.gov (United States)

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.

Poor outcome prediction by burst suppression ratio in adults with post-anoxic coma without hypothermia.

Science.gov (United States)

Yang, Qinglin; Su, Yingying; Hussain, Mohammed; Chen, Weibi; Ye, Hong; Gao, Daiquan; Tian, Fei

2014-05-01

Burst suppression ratio (BSR) is a quantitative electroencephalography (qEEG) parameter. The purpose of our study was to compare the accuracy of BSR when compared to other EEG parameters in predicting poor outcomes in adults who sustained post-anoxic coma while not being subjected to therapeutic hypothermia. EEG was registered and recorded at least once within 7 days of post-anoxic coma onset. Electrodes were placed according to the international 10-20 system, using a 16-channel layout. Each EEG expert scored raw EEG using a grading scale adapted from Young and scored amplitude-integrated electroencephalography tracings, in addition to obtaining qEEG parameters defined as BSR with a defined threshold. Glasgow outcome scales of 1 and 2 at 3 months, determined by two blinded neurologists, were defined as poor outcome. Sixty patients with Glasgow coma scale score of 8 or less after anoxic accident were included. The sensitivity (97.1%), specificity (73.3%), positive predictive value (82.5%), and negative prediction value (95.0%) of BSR in predicting poor outcome were higher than other EEG variables. BSR1 and BSR2 were reliable in predicting death (area under the curve > 0.8, P coma who do not undergo therapeutic hypothermia when compared to other qEEG parameters.

Abnormal intra-aural pressure waves associated with death in African children with acute nontraumatic coma.

Science.gov (United States)

Gwer, Samson; Kazungu, Michael; Chengo, Eddie; Ohuma, Eric O; Idro, Richard; Birch, Tony; Marchbanks, Robert; Kirkham, Fenella J; Newton, Charles R

2015-07-01

We explored the relationship between tympanic membrane displacement (TMD) measurements, a tool to monitor intracranial pressure noninvasively, and clinical features and death in children with acute coma in Kilifi, Kenya. Between November 2007 and September 2009, we made serial TMD measurements and clinical observations on children with acute coma (Blantyre coma score (BCS) ≤ 2) on the pediatric high dependency unit of Kilifi District Hospital, and on well children presenting to the hospital's outpatient department for routine follow-up. We examined middle ear function using tympanometry and measured cardiac pulse (CPA) and respiratory pulse pressure amplitudes (RPA) using the TMD analyzer. We recruited 75 children (32 (43%) females; median age 3.3 (IQR: 2.0, 4.3) years). Twenty-one (28%) children died. Higher TMD measurements predicted death. Adjusting for diagnosis, every 50 nl rise in both semirecumbent and recumbent CPA was associated with increased odds of death associated with intracranial herniation (OR: 1.61, 95% confidence interval (CI): 1.07, 2.41; P = 0.02 and OR: 1.35, 95% CI: 1.10, 1.66; P ≤ 0.01 respectively). Raised TMD pulse pressure measurements are associated with death and may be useful in detecting and monitoring risk of intracranial herniation and intracranial pressure in childhood coma.

Polyuria, acidosis, and coma following massive ibuprofen ingestion.

Science.gov (United States)

Levine, Michael; Khurana, Amandeep; Ruha, Anne-Michelle

2010-09-01

Ibuprofen was the first over-the-counter nonsteroidal anti-inflammatory drug available in the United States. Despite being a common agent of ingestion, significant toxicity in overdose is rare. We report a case of a massive ibuprofen ingestion who developed polyuria, acidosis, and coma but survived, despite having a serum ibuprofen concentration greater than previous fatal cases. A 19-year-old man ingested 90 g (1,200 mg/kg) ibuprofen. He was initially awake and alert, but his level of consciousness deteriorated over several hours. Seven hours following the ingestion, he was intubated and mechanically ventilated secondary to loss of airway reflexes. He developed a lactic acidosis and polyuria, which lasted for nearly 24 h. His serum creatinine peaked at 1.12 mg/dL. An ibuprofen level drawn 7 h postingestion was 739.2 mg/L (therapeutic 5-49 mg/L). We describe a case of a massive ibuprofen overdose characterized by metabolic acidosis, coma, and a state of high urine output who survived with aggressive supportive care. This case is unique in several ways. First, ibuprofen levels this high have only rarely been described. Second, polyuria is very poorly described following ibuprofen ingestions.

The effects of assembly bias on the inference of matter clustering from galaxy-galaxy lensing and galaxy clustering

Science.gov (United States)

McEwen, Joseph E.; Weinberg, David H.

2018-04-01

The combination of galaxy-galaxy lensing (GGL) and galaxy clustering is a promising route to measuring the amplitude of matter clustering and testing modified gravity theories of cosmic acceleration. Halo occupation distribution (HOD) modeling can extend the approach down to nonlinear scales, but galaxy assembly bias could introduce systematic errors by causing the HOD to vary with large scale environment at fixed halo mass. We investigate this problem using the mock galaxy catalogs created by Hearin & Watson (2013, HW13), which exhibit significant assembly bias because galaxy luminosity is tied to halo peak circular velocity and galaxy colour is tied to halo formation time. The preferential placement of galaxies (especially red galaxies) in older halos affects the cutoff of the mean occupation function for central galaxies, with halos in overdense regions more likely to host galaxies. The effect of assembly bias on the satellite galaxy HOD is minimal. We introduce an extended, environment dependent HOD (EDHOD) prescription to describe these results and fit galaxy correlation measurements. Crucially, we find that the galaxy-matter cross-correlation coefficient, rgm(r) ≡ ξgm(r) . [ξmm(r)ξgg(r)]-1/2, is insensitive to assembly bias on scales r ≳ 1 h^{-1} Mpc, even though ξgm(r) and ξgg(r) are both affected individually. We can therefore recover the correct ξmm(r) from the HW13 galaxy-galaxy and galaxy-matter correlations using either a standard HOD or EDHOD fitting method. For Mr ≤ -19 or Mr ≤ -20 samples the recovery of ξmm(r) is accurate to 2% or better. For a sample of red Mr ≤ -20 galaxies we achieve 2% recovery at r ≳ 2 h^{-1} Mpc with EDHOD modeling but lower accuracy at smaller scales or with a standard HOD fit. Most of our mock galaxy samples are consistent with rgm = 1 down to r = 1h-1Mpc, to within the uncertainties set by our finite simulation volume.

The effects of assembly bias on the inference of matter clustering from galaxy-galaxy lensing and galaxy clustering

Science.gov (United States)

McEwen, Joseph E.; Weinberg, David H.

2018-07-01

The combination of galaxy-galaxy lensing and galaxy clustering is a promising route to measuring the amplitude of matter clustering and testing modified gravity theories of cosmic acceleration. Halo occupation distribution (HOD) modelling can extend the approach down to non-linear scales, but galaxy assembly bias could introduce systematic errors by causing the HOD to vary with the large-scale environment at fixed halo mass. We investigate this problem using the mock galaxy catalogs created by Hearin & Watson (2013, HW13), which exhibit significant assembly bias because galaxy luminosity is tied to halo peak circular velocity and galaxy colour is tied to halo formation time. The preferential placement of galaxies (especially red galaxies) in older haloes affects the cutoff of the mean occupation function ⟨Ncen(Mmin)⟩ for central galaxies, with haloes in overdense regions more likely to host galaxies. The effect of assembly bias on the satellite galaxy HOD is minimal. We introduce an extended, environment-dependent HOD (EDHOD) prescription to describe these results and fit galaxy correlation measurements. Crucially, we find that the galaxy-matter cross-correlation coefficient, rgm(r) ≡ ξgm(r) . [ξmm(r)ξgg(r)]-1/2, is insensitive to assembly bias on scales r ≳ 1 h-1 Mpc, even though ξgm(r) and ξgg(r) are both affected individually. We can therefore recover the correct ξmm(r) from the HW13 galaxy-galaxy and galaxy-matter correlations using either a standard HOD or EDHOD fitting method. For Mr ≤ -19 or Mr ≤ -20 samples the recovery of ξmm(r) is accurate to 2 per cent or better. For a sample of red Mr ≤ -20 galaxies, we achieve 2 per cent recovery at r ≳ 2 h-1 Mpc with EDHOD modelling but lower accuracy at smaller scales or with a standard HOD fit. Most of our mock galaxy samples are consistent with rgm = 1 down to r = 1 h-1 Mpc, to within the uncertainties set by our finite simulation volume.

Prognostic and diagnostic value of EEG signal coupling measures in coma.

Science.gov (United States)

Zubler, Frederic; Koenig, Christa; Steimer, Andreas; Jakob, Stephan M; Schindler, Kaspar A; Gast, Heidemarie

2016-08-01

Our aim was to assess the diagnostic and predictive value of several quantitative EEG (qEEG) analysis methods in comatose patients. In 79 patients, coupling between EEG signals on the left-right (inter-hemispheric) axis and on the anterior-posterior (intra-hemispheric) axis was measured with four synchronization measures: relative delta power asymmetry, cross-correlation, symbolic mutual information and transfer entropy directionality. Results were compared with etiology of coma and clinical outcome. Using cross-validation, the predictive value of measure combinations was assessed with a Bayes classifier with mixture of Gaussians. Five of eight measures showed a statistically significant difference between patients grouped according to outcome; one measure revealed differences in patients grouped according to the etiology. Interestingly, a high level of synchrony between the left and right hemisphere was associated with mortality on intensive care unit, whereas higher synchrony between anterior and posterior brain regions was associated with survival. The combination with the best predictive value reached an area-under the curve of 0.875 (for patients with post anoxic encephalopathy: 0.946). EEG synchronization measures can contribute to clinical assessment, and provide new approaches for understanding the pathophysiology of coma. Prognostication in coma remains a challenging task. qEEG could improve current multi-modal approaches. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Galaxy mergers

International Nuclear Information System (INIS)

Roos, N.

1981-01-01

This thesis contains a series of four papers dealing with the effects of interactions among galaxies during the epoch of cluster formation. Galaxy interactions are investigated and the results incorporated in numerical simulations of the formation of groups and clusters of galaxies. The role of galaxy interactions is analysed in the more general context of simulations of an expanding universe. The evolution of galaxies in rich clusters is discussed. The results of the investigations are presented and their relation to other work done in the field are briefly reviewed and an attempt is made to link galaxy mergers to the occurrence of activity in galactic nuclei. (Auth.)

Anisotropic Galaxy-Galaxy Lensing in the Illustris-1 Simulation

Science.gov (United States)

Brainerd, Tereasa G.

2017-06-01

In Cold Dark Matter universes, the dark matter halos of galaxies are expected to be triaxial, leading to a surface mass density that is not circularly symmetric. In principle, this "flattening" of the dark matter halos of galaxies should be observable as an anisotropy in the weak galaxy-galaxy lensing signal. The degree to which the weak lensing signal is observed to be anisotropic, however, will depend strongly on the degree to which mass (i.e., the dark matter) is aligned with light in the lensing galaxies. That is, the anisotropy will be maximized when the major axis of the projected mass distribution is well aligned with the projected light distribution of the lens galaxies. Observational studies of anisotropic galaxy-galaxy lensing have found an anisotropic weak lensing signal around massive, red galaxies. Detecting the signal around blue, disky galaxies has, however, been more elusive. A possible explanation for this is that mass and light are well aligned within red galaxies and poorly aligned within blue galaxies (an explanation that is supported by studies of the locations of satellites of large, relatively isolated galaxies). Here we compute the weak lensing signal of isolated central galaxies in the Illustris-1 simulation. We compute the anisotropy of the weak lensing signal using two definitions of the geometry: [1] the major axis of the projected dark matter mass distribution and [2] the major axis of the projected stellar mass. On projected scales less than 15% of the virial radius, an anisotropy of order 10% is found for both definitions of the geometry. On larger scales, the anisotropy computed relative to the major axis of the projected light distribution is less than the anisotropy computed relative to the major axis of the projected dark matter. On projected scales of order the virial radius, the anisotropy obtained when using the major axis of the light is an order of magnitude less than the anisotropy obtained when using the major axis of the

Intravenous administration of levothyroxine for treatment of suspected myxedema coma complicated by severe hypothermia in a dog.

Science.gov (United States)

Henik, R A; Dixon, R M

2000-03-01

A 7-year-old male English Coonhound with suspected myxedema coma complicated by severe hypothermia and metabolic abnormalities was treated with a combination of active external and core rewarming techniques, i.v. and oral administration of levothyroxine, supplemental oxygen, and administration of fluids (0.9% NaCl solution). Myxedema coma develops as a consequence of severe hypothyroidism and is characterized by a hypometabolic, stuporous state. Myxedema coma is associated with a high mortality rate, and most reported cases have involved Doberman Pinschers. Intravenous administration of levothyroxine can be used successfully in combination with oral administration to restore normal metabolic function and assist in warming and thermoregulation, although dosages should be conservative to avoid adverse cardiovascular effects.

Galaxy formation

International Nuclear Information System (INIS)

Gribbin, J.

1979-01-01

The current debate on the origin and evolution of galaxies is reviewed and evidence to support the so-called 'isothermal' and 'adiabatic' fluctuation models considered. It is shown that new theories have to explain the formation of both spiral and elliptical galaxies and the reason for their differences. It is stated that of the most recent models the best indicates that rotating spiral galaxies are formed naturally when gas concentrates in the centre of a great halo and forms stars while ellipticals are explained by later interactions between spiral galaxies and merging, which can cancel out the rotation while producing an elliptical galaxy in which the stars, coming from two original galaxies, follow very elliptical, anisotropic orbits. (UK)

The etiology and outcome of non-traumatic coma in critical care: a systematic review.

Science.gov (United States)

Horsting, Marlene Wb B; Franken, Mira D; Meulenbelt, Jan; van Klei, Wilton A; de Lange, Dylan W

2015-04-29

Non-traumatic coma (NTC) is a serious condition requiring swift medical or surgical decision making upon arrival at the emergency department. Knowledge of the most frequent etiologies of NTC and associated mortality might improve the management of these patients. Here, we present the results of a systematic literature search on the etiologies and prognosis of NTC. Two reviewers independently performed a systematic literature search in the Pubmed, Embase and Cochrane databases with subsequent reference and citation checking. Inclusion criteria were retrospective or prospective observational studies on NTC, which reported on etiologies and prognostic information of patients admitted to the emergency department or intensive care unit. Eventually, 14 studies with enough data on NTC, were selected for this systematic literature review. The most common causes of NTC were stroke (6-54%), post-anoxic coma (3-42%), poisoning (coma (54-89%) and lowest for poisoning (0-39%) and epilepsy (0-10%). NTC represents a challenge to the emergency and the critical care physicians with an important mortality and moderate-severe disability rate. Even though, included studies were very heterogeneous, the most common causes of NTC are stroke, post anoxic, poisoning and various metabolic etiologies. The best outcome is achieved for patients with poisoning and epilepsy, while the worst outcome was seen in patients with stroke and post-anoxic coma. Adequate knowledge of the most common causes of NTC and prioritizing the causes by mortality ensures a swift and adequate work-up in diagnosis of NTC and may improve outcome.

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

International Nuclear Information System (INIS)

Kraljic, David; Rummel, Markus; Conlon, Joseph P.

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 to 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

Potencial evocado auditivo de tronco encefálico no prognóstico do coma superficial

Directory of Open Access Journals (Sweden)

Libia Camargo Ribeiro Leite

2013-08-01

Full Text Available O coma é a redução persistente do nível de consciência, arresponsivo a estímulos, devido à baixa atividade cerebral. Para verificar o nível de consciência, um recurso frequentemente utilizado é a Escala de Coma de Glasgow. Outro método que se destaca é o Potencial Evocado Auditivo de Tronco Encefálico, o qual avalia a atividade elétrica das vias auditivas ascendentes, desde o trajeto periférico até o mesencéfalo. O exame é simples, imune a medicamentos depressores e ambientes eletricamente carregados, sendo o mais adequado dos potenciais para a monitoração dos estados de coma. O presente estudo teve por objetivo verificar as características do Potencial Evocado Auditivo de Tronco Encefálico no estado de coma leve (Glasgow 7 - 8 e suas respectivas contribuições. Foi realizado um estudo prospectivo transversal em dois pacientes em coma (Glasgow 7, estado secundário a traumatismo cranioencefálico. Os resultados do exame evidenciaram presença de atividade elétrica em toda extensão da via estudada, em ambos os casos, com indicações de diferentes alterações, quanto à redução na latência entre os intervalos, morfologia e replicação das ondas. Tais diferenças foram contempladas com a evolução de cada caso: caso 1 evoluiu a alta hospitalar e caso 2 evoluiu a óbito. Os resultados confirmaram os achados da literatura, que descreve que a presença do Potencial Evocado Auditivo de Tronco Encefálico normal está associada à boa evolução do caso clínico, enquanto alterações no exame podem sinalizar para um mau prognóstico.

NUMERICAL SIMULATION OF DUST IN A COMETARY COMA: APPLICATION TO COMET 67P/CHURYUMOV-GERASIMENKO

International Nuclear Information System (INIS)

Tenishev, Valeriy; Combi, Michael R.; Rubin, Martin

2011-01-01

The Rosetta spacecraft is en route to comet 67P/Churyumov-Gerasimenko for a rendezvous, landing, and extensive orbital phase beginning in 2014. With a limited amount of available observational data, planning of the mission as well as the interpretation of measurements obtained by instruments on board the spacecraft requires modeling of the dusty/gas environment of the comet. During the mission, the collision regime in the inner coma will change starting from transitional to fully collisionless. As a result, a physically correct model has to be valid at conditions that are far from equilibrium and account for the kinetic nature of the processes occurring in the coma. A study of the multi-species coma of comet 67P/Churyumov-Gerasimenko is presented in our previous paper, where we describe our kinetic model and discuss the results of its application to cases that correspond to the different stages during the mission. In this work, we focus on numerical modeling of the dust phase in the coma of comet 67P/Churyumov-Gerasimenko and its interaction with the surrounding gas. The basic phenomena that govern the dynamics and energy balance of the dust grains are outlined. The effect of solar radiation pressure and the nucleus gravity in limiting the maximum liftable mass of the grains is discussed. The distribution of the terminal velocity of the dust grains as a function of subsolar angle is derived in the paper. We have found that in the regions with high gradients of the gas density, spike-like features can form in the dust flow. The obtained results represent the state of the coma in the vicinity of the nucleus for a series of stages throughout the Rosetta mission. The implications of the model results for future measurements by the GIADA instrument are discussed.

Cosmological parameter constraints from galaxy-galaxy lensing and galaxy clustering with the SDSS DR7

Science.gov (United States)

Mandelbaum, Rachel; Slosar, Anže; Baldauf, Tobias; Seljak, Uroš; Hirata, Christopher M.; Nakajima, Reiko; Reyes, Reinabelle; Smith, Robert E.

2013-06-01

Recent studies have shown that the cross-correlation coefficient between galaxies and dark matter is very close to unity on scales outside a few virial radii of galaxy haloes, independent of the details of how galaxies populate dark matter haloes. This finding makes it possible to determine the dark matter clustering from measurements of galaxy-galaxy weak lensing and galaxy clustering. We present new cosmological parameter constraints based on large-scale measurements of spectroscopic galaxy samples from the Sloan Digital Sky Survey (SDSS) data release 7. We generalize the approach of Baldauf et al. to remove small-scale information (below 2 and 4 h-1 Mpc for lensing and clustering measurements, respectively), where the cross-correlation coefficient differs from unity. We derive constraints for three galaxy samples covering 7131 deg2, containing 69 150, 62 150 and 35 088 galaxies with mean redshifts of 0.11, 0.28 and 0.40. We clearly detect scale-dependent galaxy bias for the more luminous galaxy samples, at a level consistent with theoretical expectations. When we vary both σ8 and Ωm (and marginalize over non-linear galaxy bias) in a flat Λ cold dark matter model, the best-constrained quantity is σ8(Ωm/0.25)0.57 = 0.80 ± 0.05 (1σ, stat. + sys.), where statistical and systematic errors (photometric redshift and shear calibration) have comparable contributions, and we have fixed ns = 0.96 and h = 0.7. These strong constraints on the matter clustering suggest that this method is competitive with cosmic shear in current data, while having very complementary and in some ways less serious systematics. We therefore expect that this method will play a prominent role in future weak lensing surveys. When we combine these data with Wilkinson Microwave Anisotropy Probe 7-year (WMAP7) cosmic microwave background (CMB) data, constraints on σ8, Ωm, H0, wde and ∑mν become 30-80 per cent tighter than with CMB data alone, since our data break several parameter

AN ANALYSIS OF CO PRODUCTION IN COMETARY COMAE: CONTRIBUTIONS FROM GAS-PHASE PHENOMENA

International Nuclear Information System (INIS)

Pierce, Donna M.; A'Hearn, Michael F.

2010-01-01

Understanding the sources of CO in cometary comae is important for understanding comet chemistry and the roles comets have played in the development of the solar system. Among comets sampled to date, the CO abundances vary widely and no direct correlation of CO abundance with other known comet properties has been identified. The picture is complicated further by the discovery of CO production in the comae of some comets, most notably comets Halley and Hale-Bopp. In this study, we investigate the conditions under which CO can be produced in the coma via gas-phase phenomena. We include photochemistry of several parent molecules, as well as two-body chemical reactions that involve the parents and their photodissociative daughter and granddaughter products. We also consider the level of excitation of 'hot' hydrogen (H*) and O( 1 D) in the network, because the level of excitation of these reactants strongly influences reaction rates. Our results suggest that the dominant gas-phase contributor to CO formation is the photodissociation of H 2 CO. Even though typical abundances of H 2 CO are at ∼1% relative to water in the coma, it produces more CO than other processes due to its relatively short photodissociation lifetime. Because other studies have shown H 2 CO to have a distributed source as well, it suggests that at least some CO formation in the coma is connected to the H 2 CO distributed source. We take the time to examine the CO 2 /CO ratio and note that while the CO 2 /CO ratio in comets Halley, Hale-Bopp, and Hyakutake are noticeably different when only native CO is considered, the CO 2 /CO ratios show greater similarity when total CO is considered. Although this sample is relatively small, should the relatively similar CO 2 /CO Total ratio of ∼0.25 indeed be constant for comets with distributed CO sources, it suggests that the extended CO source of these comets is tied directly to the overall C, H, O chemistry of comets, as is likely to happen if hydrogenation

Clusters of Galaxies

Science.gov (United States)

Huchtmeier, W. K.; Richter, O. G.; Materne, J.

1981-09-01

The large-scale structure of the universe is dominated by clustering. Most galaxies seem to be members of pairs, groups, clusters, and superclusters. To that degree we are able to recognize a hierarchical structure of the universe. Our local group of galaxies (LG) is centred on two large spiral galaxies: the Andromeda nebula and our own galaxy. Three sr:naller galaxies - like M 33 - and at least 23 dwarf galaxies (KraanKorteweg and Tammann, 1979, Astronomische Nachrichten, 300, 181) can be found in the evironment of these two large galaxies. Neighbouring groups have comparable sizes (about 1 Mpc in extent) and comparable numbers of bright members. Small dwarf galaxies cannot at present be observed at great distances.

The dynamics of aggregates of galaxies as related to their main galaxies

International Nuclear Information System (INIS)

Einasto, J.; Joeveer, M.; Kaasik, A.; Vennik, J.

1976-01-01

The dynamics of the aggregates of galaxies is compared with the dynamics of their member galaxies. It is demonstrated that within a factor 1.5-2 the dispersion of relative line-of-sight velocities is constant from the nuclei of main galaxies to the periphery of an aggregate. This isothermality of aggregates of galaxies is observed in all aggregates studied so far, from poor groups to rich clusters. The fact that the velocity dispersion of stars in galaxies is equal to that of galaxies in aggregates applies only to main galaxies. The stars in all companion galaxies have a smaller velocity dispersion of stars. The dynamical evolution of both galaxies and aggregates of galaxies is very slow. Thus the above data suggest that galaxies and their aggregates were formed together. (orig.) [de

Planck intermediate results. X. Physics of the hot gas in the Coma cluster

DEFF Research Database (Denmark)

Planck Collaboration,; Ade, P. A. R.; Aghanim, N.

2013-01-01

We present an analysis of Planck satellite data on the Coma Cluster observed via the Sunyaev-Zeldovich effect. Planck is able, for the first time, to detect SZ emission up to r ~ 3 X R_500. We test previously proposed models for the pressure distribution in clusters against the azimuthally averaged...... data. We find that the Arnaud et al. universal pressure profile does not fit Coma, and that their pressure profile for merging systems provides a good fit of the data only at rR_500 than the mean pressure profile predicted by the simulations. The Planck image shows significant local steepening of the y...

Evolution of Cerebral Atrophy in a Patient with Super Refractory Status Epilepticus Treated with Barbiturate Coma

Directory of Open Access Journals (Sweden)

Christopher R. Newey

2017-01-01

Full Text Available Introduction. Status epilepticus is associated with neuronal breakdown. Radiological sequelae of status epilepticus include diffusion weighted abnormalities and T2/FLAIR cortical hyperintensities corresponding to the epileptogenic cortex. However, progressive generalized cerebral atrophy from status epilepticus is underrecognized and may be related to neuronal death. We present here a case of diffuse cerebral atrophy that developed during the course of super refractory status epilepticus management despite prolonged barbiturate coma. Methods. Case report and review of the literature. Case. A 19-year-old male with a prior history of epilepsy presented with focal clonic seizures. His seizures were refractory to multiple anticonvulsants and eventually required pentobarbital coma for 62 days and midazolam coma for 33 days. Serial brain magnetic resonance imaging (MRI showed development of cerebral atrophy at 31 days after admission to our facility and progression of the atrophy at 136 days after admission. Conclusion. This case highlights the development and progression of generalized cerebral atrophy in super refractory status epilepticus. The cerebral atrophy was noticeable at 31 days after admission at our facility which emphasizes the urgency of definitive treatment in patients who present with super refractory status epilepticus. Further research into direct effects of therapeutic coma is warranted.

The Stellar Populations of Two Ultra-diffuse Galaxies from Optical and Near-infrared Photometry

Science.gov (United States)

Pandya, Viraj; Romanowsky, Aaron J.; Laine, Seppo; Brodie, Jean P.; Johnson, Benjamin D.; Glaccum, William; Villaume, Alexa; Cuillandre, Jean-Charles; Gwyn, Stephen; Krick, Jessica; Lasker, Ronald; Martín-Navarro, Ignacio; Martinez-Delgado, David; van Dokkum, Pieter

2018-05-01

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospector fully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (≳7.7 Gyr) and surprisingly metal-poor ([Z/Z ⊙] ≲ ‑1.0) stellar population, even after marginalizing over uncertainties on diffuse interstellar dust. In contrast, the field UDG DGSAT I shows evidence of being younger than the Virgo UDG, with an extended star formation history and an age posterior extending down to ∼3 Gyr. The stellar metallicity of DGSAT I is sub-solar but higher than that of the Virgo UDG, with [Z/{Z}ȯ ]=-{0.63}-0.62+0.35; in the case of exactly zero diffuse interstellar dust, DGSAT I may even have solar metallicity. With VCC 1287 and several Coma UDGs, a general picture is emerging where cluster UDGs may be “failed” galaxies, but the field UDG DGSAT I seems more consistent with a stellar feedback-induced expansion scenario. In the future, our approach can be applied to a large and diverse sample of UDGs down to faint surface brightness limits, with the goal of constraining their stellar ages, stellar metallicities, and circumstellar and diffuse interstellar dust content.

Prediction of recovery from a post-traumatic coma state by diffusion-weighted imaging (DWI) in patients with diffuse axonal injury

International Nuclear Information System (INIS)

Zheng, W.B.; Liu, G.R.; Wu, R.H.; Li, L.P.

2007-01-01

To determine whether diffusion-weighted magnetic resonance (MR) imaging findings combined with initial clinical factors indicate the depth of shearing lesions in the brain structure and therefore relate to coma duration in diffuse axonal injury (DAI). A total of 74 adult patients (48 male and 26 female) with DAI were examined with conventional MR imaging and diffusion-weighted MR imaging between 2 hours and 20 days after injury. Apparent diffusion coefficient (ADC) maps were obtained and the mean ADC values of each region of interest (ROI) were measured using MRI console software. The involvement of the brainstem, deep gray matter, and corpus callosum was determined for each sequence separately as well as for the combination of all sequences. The correlations between MR imaging findings indicating the presence of apparent brain injury combined with initial clinical factors were determined. Clinical characteristics, such as initial score on the Glasgow coma scale (GCS), age and number of all lesions, and ADC scores were predictive of the duration of coma. It was possible to predict post-traumatic coma duration in DAI from cerebral MR imaging findings combined with clinical prognostic factors in the acute to subacute stage after head injury. Age, ADC scores, GCS score and number of lesions were highly significant in predicting coma duration. The technique presented here might provide a tool for in vivo detection of DAI to allow the prediction of the coma duration during the early stages in patients with traumatic brain injury. (orig.)

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

Science.gov (United States)

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.

Superclusters and galaxy formation

International Nuclear Information System (INIS)

Einasto, J.; Joeveer, M.; Saar, E.

1979-01-01

The spatial distribution of Galaxies and Galaxy congestions in the southern galactic hemisphere is studied. The rich galaxy congestions, containing many elliptic Galaxies and radiogalaxies, are linked with each other by chains of scanty congestions with moderate content of elliptic Galaxies and radiogalaxies. The flat formation, linking the density pikes and the intermediate chains, can reasonably be called supercongestion. In the central region of supercongestions there is a thin layer of Galaxies consisting of only spiral Galaxies. The neighbouring supercongestions touch each other, while the intersupercongestion space contains no Galaxy congestions and almost no Galaxies. It is shown that such a structure was, apparently, formed before the formation of Galaxies

Separating intrinsic alignment and galaxy-galaxy lensing

International Nuclear Information System (INIS)

Blazek, Jonathan; Seljak, Uroš; Mandelbaum, Rachel; Nakajima, Reiko

2012-01-01

The coherent physical alignment of galaxies is an important systematic for gravitational lensing studies as well as a probe of the physical mechanisms involved in galaxy formation and evolution. We develop a formalism for treating this intrinsic alignment (IA) in the context of galaxy-galaxy lensing and present an improved method for measuring IA contamination, which can arise when sources physically associated with the lens are placed behind the lens due to photometric redshift scatter. We apply the technique to recent Sloan Digital Sky Survey (SDSS) measurements of Luminous Red Galaxy lenses and typical ( ∼ L * ) source galaxies with photometric redshifts selected from the SDSS imaging data. Compared to previous measurements, this method has the advantage of being fully self-consistent in its treatment of the IA and lensing signals, solving for the two simultaneously. We find an IA signal consistent with zero, placing tight constraints on both the magnitude of the IA effect and its potential contamination to the lensing signal. While these constraints depend on source selection and redshift quality, the method can be applied to any measurement that uses photometric redshifts. We obtain a model-independent upper-limit of roughly 10% IA contamination for projected separations of r p ≈ 0.1–10 h −1 Mpc. With more stringent photo-z cuts and reasonable assumptions about the physics of intrinsic alignments, this upper limit is reduced to 1–2%. These limits are well below the statistical error of the current lensing measurements. Our results suggest that IA will not present intractable challenges to the next generation of galaxy-galaxy lensing experiments, and the methods presented here should continue to aid in our understanding of alignment processes and in the removal of IA from the lensing signal

Properties of Stellar Streams in the Galactic Disk

Directory of Open Access Journals (Sweden)

Marsakov V. A.

2016-12-01

Full Text Available Stars of the Sirius, Coma Berenices, Hyades, Pleiades, Wolf 630, Dehnen 6, Dehnen 14, HR 1614, η Cephei, γ Leo streams, the newly identified two subgroups of the Hercules stream, and the streams BB 14, BB 17, BB 20, and BB 21 are selected using the components of space velocities from three independent catalogs. The relationship between their ages, metallicities and relative abundances of α-elements are studied. The data of the three catalogs show slightly different properties for each of the streams studied. However, the general tendency shows that the dependences studied for the stars within the streams hardly differ from those found for the field stars with the corresponding velocities. The dependences found confirm the assumption that all of the streams studied could have been formed as a result of resonance effects due to the Galactic bar or spiral density waves acting on field stars.

COMBINED EFFECTS OF GALAXY INTERACTIONS AND LARGE-SCALE ENVIRONMENT ON GALAXY PROPERTIES

International Nuclear Information System (INIS)

Park, Changbom; Choi, Yun-Young

2009-01-01

We inspect the coupled dependence of physical parameters of the Sloan Digital Sky Survey galaxies on the small-scale (distance to and morphology of the nearest neighbor galaxy) and the large-scale (background density smoothed over 20 nearby galaxies) environments. The impacts of interaction on galaxy properties are detected at least out to the neighbor separation corresponding to the virial radius of galaxies, which is typically between 200 and 400 h -1 kpc for the galaxies in our sample. To detect these long-range interaction effects, it is crucial to divide galaxy interactions into four cases dividing the morphology of target and neighbor galaxies into early and late types. We show that there are two characteristic neighbor-separation scales where the galaxy interactions cause abrupt changes in the properties of galaxies. The first scale is the virial radius of the nearest neighbor galaxy r vir,nei . Many physical parameters start to deviate from those of extremely isolated galaxies at the projected neighbor separation r p of about r vir,nei . The second scale is at r p ∼ 0.05r vir,nei = 10-20 h -1 kpc, and is the scale at which the galaxies in pairs start to merge. We find that late-type neighbors enhance the star formation activity of galaxies while early-type neighbors reduce it, and that these effects occur within r vir,nei . The hot halo gas and cold disk gas must be participating in the interactions at separations less than the virial radius of the galaxy plus dark halo system. Our results also show that the role of the large-scale density in determining galaxy properties is minimal once luminosity and morphology are fixed. We propose that the weak residual dependence of galaxy properties on the large-scale density is due to the dependence of the halo gas property on the large-scale density.

Joint analysis of galaxy-galaxy lensing and galaxy clustering: Methodology and forecasts for Dark Energy Survey

International Nuclear Information System (INIS)

Park, Y.; Krause, E.; Dodelson, S.; Jain, B.; Amara, A.

2016-01-01

Here, the joint analysis of galaxy-galaxy lensing and galaxy clustering is a promising method for inferring the growth function of large-scale structure. Anticipating a near future application of this analysis to Dark Energy Survey (DES) measurements of galaxy positions and shapes, we develop a practical approach to modeling the assumptions and systematic effects affecting the joint analysis of small-scale galaxy-galaxy lensing and large-scale galaxy clustering. Introducing parameters that characterize the halo occupation distribution (HOD), photometric redshift uncertainties, and shear measurement errors, we study how external priors on different subsets of these parameters affect our growth constraints. Degeneracies within the HOD model, as well as between the HOD and the growth function, are identified as the dominant source of complication, with other systematic effects being subdominant. The impact of HOD parameters and their degeneracies necessitate the detailed joint modeling of the galaxy sample that we employ. We conclude that DES data will provide powerful constraints on the evolution of structure growth in the Universe, conservatively/optimistically constraining the growth function to 7.9%/4.8% with its first-year data that cover over 1000 square degrees, and to 3.9%/2.3% with its full five-year data that will survey 5000 square degrees, including both statistical and systematic uncertainties.

On-chip COMA cache-coherence protocol for microgrids of microthreaded cores

NARCIS (Netherlands)

Zhang, L.; Jesshope, C.

2008-01-01

This paper describes an on-chip COMA cache coherency protocol to support the microthread model of concurrent program composition. The model gives a sound basis for building multi-core computers as it captures concurrency, abstracts communication and identifies resources, such as processor groups

Spectroscopy of the galaxy components of N and Seyfert galaxies

International Nuclear Information System (INIS)

Boroson, T.A.; Oke, J.B.; Palomar Observatory, Pasadena, CA)

1987-01-01

Nuclear and off-nuclear spectra of nine active galaxies are presented. The sample consists of four Seyfert galaxies, two N galaxies, one Seyfert radio galaxy, and one liner/Seyfert 2 galaxy. All of the objects show continuum emission off the nucleus. Four clearly show absorption features from a stellar population. Velocities have been measured for the off-nuclear emission and absorption lines. In the case of I Zw 1, the absorption-line velocities are inconsistent with 21-cm H I measurements of this object. 26 references

Acupuncture Treatment for 15 Cases of Post-traumatic Coma

Institute of Scientific and Technical Information of China (English)

He Jing; Wu Bin; Zhang Yongling; Wang Xinzhong

2005-01-01

In order to observe the effects of acupuncture combined with point-injection therapy on post-traumatic coma, 30 such cases were randomly divided into the following two groups. The patients in the control group were simply treated with the basic neural medical treatment; while patients in the treatment group were treated by acupuncture and point-injection therapy in addition to the above treatment. Comparisons were made between the two groups in the therapeutic effects by GCS evaluations as well as in the changes of main symptoms. The results showed that the GCS value in the treatment group was higher than that of the control group, but with no statistical significance (P＞0.05). However, the main symptoms of the patients in treatment group, such as aphasia, hemiplegia, and injuries of cranial nerves (including injuries of the facial, oculomotor and abducent nerves) were obviously improved, showing significant differences as compared with the control group (P＜0.05). Conclusion can be made that acupuncture combined with point-injection has the consciousness-inducing effect for post-traumatic coma, and shows good effects for the cranial nerve injuries and aphasia.

Myxedema coma: A case report of pediatric emergency care.

Science.gov (United States)

Zhu, Yueniu; Qiu, Wenjuan; Deng, Mengyan; Zhu, Xiaodong

2017-05-01

Myxedema coma (MC) is extremely rare but lethal in pediatric patients with hypothyroidism leading to altered mental status and hypothermia. But there is no clinical guideline for such cases. A 6-year-old Chinese girl presented with coma and hypothermia preceded by pneumonia. Her lab results were: free thyroxin (T4) 4.18 pmol/L and thyroid-stimulating hormone (TSH) > 150 μIU/mL with extremely elevated anti-thyroid peroxidase (TPO-Ab) and anti-thyroglobulin. Pneumonia, mild pleural, and pericardial effusion were seen on computed tomographic (CT) scan. MC, autoimmune hypothyroidism, pneumonia and sepsis were diagnosed. Gastric levothyroxine, intravenous dexamethasone and antibiotics were administered. Her consciousness was restored and temperature returned to normal 2 days after starting levothyroxine. She was discharged two weeks later. MC is rare but may be the initial presentation in pediatric patients with prolonged untreated hypothyroidism. Autoimmune thyroiditis could cause hypothyroidism in children. MC should be suspected in pediatric patients with altered mental status, hypothermia and cardiovascular instability. Treatment with 100 mg/m of gastric levothyroxine is an option for pediatric patients with MC.

Challenges in the Management of a Patient with Myxoedema Coma ...

African Journals Online (AJOL)

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 ...

Galaxy and Mass Assembly (GAMA): small-scale anisotropic galaxy clustering and the pairwise velocity dispersion of galaxies

Science.gov (United States)

Loveday, J.; Christodoulou, L.; Norberg, P.; Peacock, J. A.; Baldry, I. K.; Bland-Hawthorn, J.; Brown, M. J. I.; Colless, M.; Driver, S. P.; Holwerda, B. W.; Hopkins, A. M.; Kafle, P. R.; Liske, J.; Lopez-Sanchez, A. R.; Taylor, E. N.

2018-03-01

The galaxy pairwise velocity dispersion (PVD) can provide important tests of non-standard gravity and galaxy formation models. We describe measurements of the PVD of galaxies in the Galaxy and Mass Assembly (GAMA) survey as a function of projected separation and galaxy luminosity. Due to the faint magnitude limit (r PVD to smaller scales (r⊥ = 0.01 h - 1 Mpc) than previous work. The measured PVD at projected separations r⊥ ≲ 1 h - 1 Mpc increases near monotonically with increasing luminosity from σ12 ≈ 200 km s - 1 at Mr = -17 mag to σ12 ≈ 600 km s - 1 at Mr ≈ -22 mag. Analysis of the Gonzalez-Perez et al. (2014) GALFORM semi-analytic model yields no such trend of PVD with luminosity: the model overpredicts the PVD for faint galaxies. This is most likely a result of the model placing too many low-luminosity galaxies in massive haloes.

Formation of galaxies

International Nuclear Information System (INIS)

Szalay, A.S.

1984-12-01

The present theories of galaxy formation are reviewed. The relation between peculiar velocities and the correlation function of galaxies points to the possibility that galaxies do not form uniformly everywhere. Scale invariant properties of the cluster-cluster correlations are discussed. Comparing the correlation functions in a dimensionless way, galaxies appear to be stronger clustered, in contrast with the comparison of the dimensional amplitudes of the correlation functions. Theoretical implications of several observations as Lyman-α clouds, correlations of faint galaxies are discussed. None of the present theories of galaxy formation can account for all facts in a natural way. 29 references

The intrinsic shape of galaxies in SDSS/Galaxy Zoo

Science.gov (United States)

Rodríguez, Silvio; Padilla, Nelson D.

2013-09-01

By modelling the axis ratio distribution of Sloan Digital Sky Survey (SDSS) Data Release 8 galaxies, we find the intrinsic 3D shapes of spirals and ellipticals. We use morphological information from the Galaxy Zoo project and assume a non-parametric distribution intrinsic of shapes, while taking into account dust extinction. We measure the dust extinction of the full sample of spiral galaxies and find a smaller value than previous estimations, with an edge-on extinction of E_0 = 0.284^{+0.015}_{-0.026} in the SDSS r band. We also find that the distribution of minor to major axis ratio has a mean value of 0.267 ± 0.009, slightly larger than previous estimates mainly due to the lower extinction used; the same affects the circularity of galactic discs, which are found to be less round in shape than in previous studies, with a mean ellipticity of 0.215 ± 0.013. For elliptical galaxies, we find that the minor to major axis ratio, with a mean value of 0.584 ± 0.006, is larger than previous estimations due to the removal of spiral interlopers present in samples with morphological information from photometric profiles. These interlopers are removed when selecting ellipticals using Galaxy Zoo data. We find that the intrinsic shapes of galaxies and their dust extinction vary with absolute magnitude, colour and physical size. We find that bright elliptical galaxies are more spherical than faint ones, a trend that is also present with galaxy size, and that there is no dependence of elliptical galaxy shape with colour. For spiral galaxies, we find that the reddest ones have higher dust extinction as expected, due to the fact that this reddening is mainly due to dust. We also find that the thickness of discs increases with luminosity and size, and that brighter, smaller and redder galaxies have less round discs.

Galaxy-galaxy weak gravitational lensing in f(R) gravity

Science.gov (United States)

Li, Baojiu; Shirasaki, Masato

2018-03-01

We present an analysis of galaxy-galaxy weak gravitational lensing (GGL) in chameleon f(R) gravity - a leading candidate of non-standard gravity models. For the analysis, we have created mock galaxy catalogues based on dark matter haloes from two sets of numerical simulations, using a halo occupation distribution (HOD) prescription which allows a redshift dependence of galaxy number density. To make a fairer comparison between the f(R) and Λ cold dark matter (ΛCDM) models, their HOD parameters are tuned so that the galaxy two-point correlation functions in real space (and therefore the projected two-point correlation functions) match. While the f(R) model predicts an enhancement of the convergence power spectrum by up to ˜ 30 per cent compared to the standard ΛCDM model with the same parameters, the maximum enhancement of GGL is only half as large and less than 5 per cent on separations above ˜1-2 h-1 Mpc, because the latter is a cross-correlation of shear (or matter, which is more strongly affected by modified gravity) and galaxy (which is weakly affected given the good match between galaxy autocorrelations in the two models) fields. We also study the possibility of reconstructing the matter power spectrum by combination of GGL and galaxy clustering in f(R) gravity. We find that the galaxy-matter cross-correlation coefficient remains at unity down to ˜2-3 h-1 Mpc at relevant redshifts even in f(R) gravity, indicating joint analysis of GGL and galaxy clustering can be a powerful probe of matter density fluctuations in chameleon gravity. The scale dependence of the model differences in their predictions of GGL can potentially allows us to break the degeneracy between f(R) gravity and other cosmological parameters such as Ωm and σ8.

Neural signature of coma revealed by posteromedial cortex connection density analysis.

Science.gov (United States)

Malagurski, Briguita; Péran, Patrice; Sarton, Benjamine; Riu, Beatrice; Gonzalez, Leslie; Vardon-Bounes, Fanny; Seguin, Thierry; Geeraerts, Thomas; Fourcade, Olivier; de Pasquale, Francesco; Silva, Stein

2017-01-01

Posteromedial cortex (PMC) is a highly segregated and dynamic core, which appears to play a critical role in internally/externally directed cognitive processes, including conscious awareness. Nevertheless, neuroimaging studies on acquired disorders of consciousness, have traditionally explored PMC as a homogenous and indivisible structure. We suggest that a fine-grained description of intrinsic PMC topology during coma, could expand our understanding about how this cortical hub contributes to consciousness generation and maintain, and could permit the identification of specific markers related to brain injury mechanism and useful for neurological prognostication. To explore this, we used a recently developed voxel-based unbiased approach, named functional connectivity density (CD). We compared 27 comatose patients (15 traumatic and 12 anoxic), to 14 age-matched healthy controls. The patients' outcome was assessed 3 months later using Coma Recovery Scale-Revised (CRS-R). A complex pattern of decreased and increased connections was observed, suggesting a network imbalance between internal/external processing systems, within PMC during coma. The number of PMC voxels with hypo-CD positive correlation showed a significant negative association with the CRS-R score, notwithstanding aetiology. Traumatic injury specifically appeared to be associated with a greater prevalence of hyper-connected (negative correlation) voxels, which was inversely associated with patient neurological outcome. A logistic regression model using the number of hypo-CD positive and hyper-CD negative correlations, accurately permitted patient's outcome prediction (AUC = 0.906, 95%IC = 0.795-1). These points might reflect adaptive plasticity mechanism and pave the way for innovative prognosis and therapeutics methods.

Emulating galaxy clustering and galaxy-galaxy lensing into the deeply nonlinear regime: methodology, information, and forecasts

OpenAIRE

Wibking, Benjamin D.; Salcedo, Andrés N.; Weinberg, David H.; Garrison, Lehman H.; Ferrer, Douglas; Tinker, Jeremy; Eisenstein, Daniel; Metchnik, Marc; Pinto, Philip

2017-01-01

The combination of galaxy-galaxy lensing (GGL) with galaxy clustering is one of the most promising routes to determining the amplitude of matter clustering at low redshifts. We show that extending clustering+GGL analyses from the linear regime down to $\\sim 0.5 \\, h^{-1}$ Mpc scales increases their constraining power considerably, even after marginalizing over a flexible model of non-linear galaxy bias. Using a grid of cosmological N-body simulations, we construct a Taylor-expansion emulator ...

Rosetta/Alice Measurements of Atomic and Molecular Abundances in the Coma of 67P/Churyumov-Gerasimenko

Science.gov (United States)

Vervack, R. J., Jr.; Weaver, H. A., Jr.; Knight, M. M.; Feldman, P.; Stern, A.; Parker, J. W.; Feaga, L. M.; Steffl, A.; Bertaux, J. L.; A'Hearn, M. F.; Keeney, B. A.

2017-12-01

During the Rosetta orbital phase from August 2014 through September 2016, the Alice far-ultraviolet (FUV) imaging spectrograph routinely monitored the FUV emission from the coma of 67P/Churyumov-Gerasimenko (67P). These data, spanning 700-2050 Å, provide both spatial and temporal information on the evolution of the coma composition throughout the encounter. Emissions from hydrogen (Lyman beta at 1025 Å), oxygen (1304 Å triplet, 1356 Å), sulfur (1429 Å and 1479 Å multiplets, 1814 Å triplet), and carbon (1561 Å, 1657 Å) were regularly observed, as well as emission from the CO Fourth Positive and Cameron bands. We present a preliminary analysis of these emissions with a focus on the abundances in the coma and a mapping of the temporal and spatial variations. Both short-term (days) and long-term (months) variations will be discussed in the context of rotational and seasonal timeframes. We also present ratios among various species with the goal of identifying the dominant processes at work in the coma as a function of time. Rosetta is an ESA mission with contributions from its member states and NASA. The Alice team acknowledges continuing support from NASA's Jet Propulsion Laboratory through contract 1336850 to the Southwest Research Institute. RJV's work was supported by a subcontract from Southwest Research Institute to the Johns Hopkins University Applied Physics Laboratory.

Galaxy formation

International Nuclear Information System (INIS)

Silk, J.; Di Cintio, A.; Dvorkin, I.

2014-01-01

Galaxy formation is at the forefront of observation and theory in cosmology. An improved understanding is essential for improving our knowledge both of the cosmological parameters, of the contents of the universe, and of our origins. In these lectures intended for graduate students, galaxy formation theory is reviewed and confronted with recent observational issues. In lecture 1, the following topics are presented: star formation considerations, including IMF, star formation efficiency and star formation rate, the origin of the galaxy luminosity function, and feedback in dwarf galaxies. In lecture 2, we describe formation of disks and massive spheroids, including the growth of supermassive black holes, negative feedback in spheroids, the AGN-star formation connection, star formation rates at high redshift and the baryon fraction in galaxies.

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

Science.gov (United States)

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.

Comparison of the Full Outline of UnResponsiveness score and the Glasgow Coma Scale in predicting mortality in critically ill patients*.

Science.gov (United States)

Wijdicks, Eelco F M; Kramer, Andrew A; Rohs, Thomas; Hanna, Susan; Sadaka, Farid; O'Brien, Jacklyn; Bible, Shonna; Dickess, Stacy M; Foss, Michelle

2015-02-01

Impaired consciousness has been incorporated in prediction models that are used in the ICU. The Glasgow Coma Scale has value but is incomplete and cannot be assessed in intubated patients accurately. The Full Outline of UnResponsiveness score may be a better predictor of mortality in critically ill patients. Thirteen ICUs at five U.S. hospitals. One thousand six hundred ninety-five consecutive unselected ICU admissions during a six-month period in 2012. Glasgow Coma Scale and Full Outline of UnResponsiveness score were recorded within 1 hour of admission. Baseline characteristics and physiologic components of the Acute Physiology and Chronic Health Evaluation system, as well as mortality were linked to Glasgow Coma Scale/Full Outline of UnResponsiveness score information. None. We recruited 1,695 critically ill patients, of which 1,645 with complete data could be linked to data in the Acute Physiology and Chronic Health Evaluation system. The area under the receiver operating characteristic curve of predicting ICU mortality using the Glasgow Coma Scale was 0.715 (95% CI, 0.663-0.768) and using the Full Outline of UnResponsiveness score was 0.742 (95% CI, 0.694-0.790), statistically different (p = 0.001). A similar but nonsignificant difference was found for predicting hospital mortality (p = 0.078). The respiratory and brainstem reflex components of the Full Outline of UnResponsiveness score showed a much wider range of mortality than the verbal component of Glasgow Coma Scale. In multivariable models, the Full Outline of UnResponsiveness score was more useful than the Glasgow Coma Scale for predicting mortality. The Full Outline of UnResponsiveness score might be a better prognostic tool of ICU mortality than the Glasgow Coma Scale in critically ill patients, most likely a result of incorporating brainstem reflexes and respiration into the Full Outline of UnResponsiveness score.

wft4galaxy: a workflow testing tool for galaxy.

Science.gov (United States)

Piras, Marco Enrico; Pireddu, Luca; Zanetti, Gianluigi

2017-12-01

Workflow managers for scientific analysis provide a high-level programming platform facilitating standardization, automation, collaboration and access to sophisticated computing resources. The Galaxy workflow manager provides a prime example of this type of platform. As compositions of simpler tools, workflows effectively comprise specialized computer programs implementing often very complex analysis procedures. To date, no simple way to automatically test Galaxy workflows and ensure their correctness has appeared in the literature. With wft4galaxy we offer a tool to bring automated testing to Galaxy workflows, making it feasible to bring continuous integration to their development and ensuring that defects are detected promptly. wft4galaxy can be easily installed as a regular Python program or launched directly as a Docker container-the latter reducing installation effort to a minimum. Available at https://github.com/phnmnl/wft4galaxy under the Academic Free License v3.0. marcoenrico.piras@crs4.it. © The Author 2017. Published by Oxford University Press.

Rebuilding Spiral Galaxies

Science.gov (United States)

2005-01-01

Major Observing Programme Leads to New Theory of Galaxy Formation Summary Most present-day large galaxies are spirals, presenting a disc surrounding a central bulge. Famous examples are our own Milky Way or the Andromeda Galaxy. When and how did these spiral galaxies form? Why do a great majority of them present a massive central bulge? An international team of astronomers [1] presents new convincing answers to these fundamental questions. For this, they rely on an extensive dataset of observations of galaxies taken with several space- and ground-based telescopes. In particular, they used over a two-year period, several instruments on ESO's Very Large Telescope. Among others, their observations reveal that roughly half of the present-day stars were formed in the period between 8,000 million and 4,000 million years ago, mostly in episodic burst of intense star formation occurring in Luminous Infrared Galaxies. From this and other evidence, the astronomers devised an innovative scenario, dubbed the "spiral rebuilding". They claim that most present-day spiral galaxies are the results of one or several merger events. If confirmed, this new scenario could revolutionise the way astronomers think galaxies formed. PR Photo 02a/05: Luminosity - Oxygen Abundance Relation for Galaxies (VLT) PR Photo 02b/05: The Spiral Rebuilding Scenario A fleet of instruments How and when did galaxies form? How and when did stars form in these island universes? These questions are still posing a considerable challenge to present-day astronomers. Front-line observational results obtained with a fleet of ground- and space-based telescopes by an international team of astronomers [1] provide new insights into these fundamental issues. For this, they embarked on an ambitious long-term study at various wavelengths of 195 galaxies with a redshift [2] greater than 0.4, i.e. located more than 4000 million light-years away. These galaxies were studied using ESO's Very Large Telescope, as well as the

STRUCTURES OF LOCAL GALAXIES COMPARED TO HIGH-REDSHIFT STAR-FORMING GALAXIES

International Nuclear Information System (INIS)

Petty, Sara M.; De Mello, DuIlia F.; Gallagher, John S.; Gardner, Jonathan P.; Lotz, Jennifer M.; Matt Mountain, C.; Smith, Linda J.

2009-01-01

The rest-frame far-ultraviolet morphologies of eight nearby interacting and starburst galaxies (Arp 269, M 82, Mrk 8, NGC 520, NGC 1068, NGC 3079, NGC 3310, and NGC 7673) are compared with 54 galaxies at z ∼ 1.5 and 46 galaxies at z ∼ 4 observed in the Great Observatories Origins Deep Survey (GOODS) taken with the Advanced Camera for Surveys onboard the Hubble Space Telescope. The nearby sample is artificially redshifted to z ∼ 1.5 and 4 by applying luminosity and size scaling. We compare the simulated galaxy morphologies to real z ∼ 1.5 and 4 UV-bright galaxy morphologies. We calculate the Gini coefficient (G), the second-order moment of the brightest 20% of the galaxy's flux (M 20 ), and the Sersic index (n). We explore the use of nonparametric methods with two-dimensional profile fitting and find the combination of M 20 with n an efficient method to classify galaxies as having merger, exponential disk, or bulge-like morphologies. When classified according to G and M 20 20/30% of real/simulated galaxies at z ∼ 1.5 and 37/12% at z ∼ 4 have bulge-like morphologies. The rest have merger-like or intermediate distributions. Alternatively, when classified according to the Sersic index, 70% of the z ∼ 1.5 and z ∼ 4 real galaxies are exponential disks or bulge-like with n>0.8, and ∼ 30% of the real galaxies are classified as mergers. The artificially redshifted galaxies have n values with ∼ 35% bulge or exponential at z ∼ 1.5 and 4. Therefore, ∼ 20%-30% of Lyman-break galaxies have structures similar to local starburst mergers, and may be driven by similar processes. We assume merger-like or clumpy star-forming galaxies in the GOODS field have morphological structure with values n 20 > - 1.7. We conclude that Mrk 8, NGC 3079, and NGC 7673 have structures similar to those of merger-like and clumpy star-forming galaxies observed at z ∼ 1.5 and 4.

Chemical evolution of galaxies

International Nuclear Information System (INIS)

Vigroux, Laurent

1979-01-01

This research thesis addresses theories on the chemical evolution of galaxies which aim at explaining abundances of different elements in galaxies, and more particularly aims at improving the model by modifying hypotheses. After a description of the simple model and of its uncertainties, the author shows how it is possible to understand the evolution of the main elements. Predictions obtained with this model are then compared with the present knowledge on galaxies by considering them according to an increasing complexity: Sun's neighbourhood, our galaxy, other spiral galaxies, elliptical galaxies, and finally galaxy clusters. A specific attention is given to irregular galaxies which are the simplest systems [fr

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.

Science.gov (United States)

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.

The comparison of modified early warning score and Glasgow coma ...

African Journals Online (AJOL)

Introduction: The purpose of this study is to assess and compare the discriminatory ability of the Glasgow coma scale (GCS)‑age‑systolic blood pressure (GAP) score and modified early warning scoring system (mEWS) score for 4‑week mortality, for the patients being in the triage category 1 and 2 who refer to Emergency ...

Challenges in the Management of a Patient with Myxoedema Coma ...

African Journals Online (AJOL)

ism.1 The incidence in western countries is reported to be 0.22 million per year, however, there is a paucity of data from countries adjacent to the equator.2 Myxoede- ma coma is a medical emergency associated with high mortality rates ranging from 25–60% even with the best possible treatment and settings.1,3 Patients ...

Non-thermal Hard X-Ray Emission from Coma and Several Abell Clusters

International Nuclear Information System (INIS)

Correa, C

2004-01-01

We report results of hard X-Ray observations of the clusters Coma, Abell 496, Abell754, Abell 1060, Abell 1367, Abell2256 and Abell3558 using RXTE data from the NASA HEASARC public archive. Specifically we searched for clusters with hard x-ray emission that can be fitted by a power law because this would indicate that the cluster is a source of non-thermal emission. We are assuming the emission mechanism proposed by Vahk Petrosian where the inter cluster space contains clouds of relativistic electrons that by themselves create a magnetic field and emit radio synchrotron radiation. These relativistic electrons Inverse-Compton scatter Microwave Background photons up to hard x-ray energies. The clusters that were found to be sources of non-thermal hard x-rays are Coma, Abell496, Abell754 and Abell 1060

Cosmological constraints from galaxy clustering and the mass-to-number ratio of galaxy clusters: marginalizing over the physics of galaxy formation

Energy Technology Data Exchange (ETDEWEB)

Reddick, Rachel M.; Wechsler, Risa H.; Lu, Yu [Kavli Institute for Particle Astrophysics and Cosmology, Physics Department, Stanford University, Stanford, CA 94305 (United States); Tinker, Jeremy L., E-mail: rmredd@stanford.edu, E-mail: rwechsler@stanford.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003 (United States)

2014-03-10

Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as on the cosmological model, and galaxy formation is still not a well-constrained process. Thus, methods that probe cosmology using galaxies as tracers for dark matter must be able to accurately estimate the cosmological parameters. This can be done without knowing details of galaxy formation a priori as long as the galaxies are well represented by a halo occupation distribution (HOD). We apply this reasoning to the method of obtaining Ω {sub m} and σ{sub 8} from galaxy clustering combined with the mass-to-number ratio of galaxy clusters. To test the sensitivity of this method to variations due to galaxy formation, we consider several different models applied to the same cosmological dark matter simulation. The cosmological parameters are then estimated using the observables in each model, marginalizing over the parameters of the HOD. We find that for models where the galaxies can be well represented by a parameterized HOD, this method can successfully extract the desired cosmological parameters for a wide range of galaxy formation prescriptions.

Cosmological constraints from galaxy clustering and the mass-to-number ratio of galaxy clusters: marginalizing over the physics of galaxy formation

International Nuclear Information System (INIS)

Reddick, Rachel M.; Wechsler, Risa H.; Lu, Yu; Tinker, Jeremy L.

2014-01-01

Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as on the cosmological model, and galaxy formation is still not a well-constrained process. Thus, methods that probe cosmology using galaxies as tracers for dark matter must be able to accurately estimate the cosmological parameters. This can be done without knowing details of galaxy formation a priori as long as the galaxies are well represented by a halo occupation distribution (HOD). We apply this reasoning to the method of obtaining Ω m and σ 8 from galaxy clustering combined with the mass-to-number ratio of galaxy clusters. To test the sensitivity of this method to variations due to galaxy formation, we consider several different models applied to the same cosmological dark matter simulation. The cosmological parameters are then estimated using the observables in each model, marginalizing over the parameters of the HOD. We find that for models where the galaxies can be well represented by a parameterized HOD, this method can successfully extract the desired cosmological parameters for a wide range of galaxy formation prescriptions.

Measuring Extinction in Local Group Galaxies Using Background Galaxies

Science.gov (United States)

Wyder, T. K.; Hodge, P. W.

1999-05-01

Knowledge of the distribution and quantity of dust in galaxies is important for understanding their structure and evolution. The goal of our research is to measure the total extinction through Local Group galaxies using measured properties of background galaxies. Our method relies on the SExtractor software as an objective and automated method of detecting background galaxies. In an initial test, we have explored two WFPC2 fields in the SMC and two in M31 obtained from the HST archives. The two pointings in the SMC are fields around the open clusters L31 and B83 while the two M31 fields target the globular clusters G1 and G170. Except for the G1 observations of M31, the fields chosen are very crowded (even when observed with HST) and we chose them as a particularly stringent test of the method. We performed several experiments using a series of completeness tests that involved superimposing comparison fields, adjusted to the equivalent exposure time, from the HST Medium-Deep and Groth-Westphal surveys. These tests showed that for crowded fields, such as the two in the core of the SMC and the one in the bulge of M31, this automated method of detecting galaxies can be completely dominated by the effects of crowding. For these fields, only a small fraction of the added galaxies was recovered. However, in the outlying G1 field in M31, almost all of the added galaxies were recovered. The numbers of actual background galaxies in this field are consistent with zero extinction. As a follow-up experiment, we used image processing techniques to suppress stellar objects while enhancing objects with non-stellar, more gradual luminosity profiles. This method yielded significant numbers of background galaxies in even the most crowded fields, which we are now analyzing to determine the total extinction and reddening caused by the foreground galaxy.

Combination of Glasgow Coma Scale, Age, and Systolic Blood Pressure in Assessing Patients’ Outcomes with Decreased Consciousness

Directory of Open Access Journals (Sweden)

Amir S Madjid

2017-04-01

Full Text Available Glasgow Coma Scale (GCS is commonly used to assess outcomes of patients with loss of consciousness, but it is insufficient in predicting the outcome of some cases. This study aimed to assess the combination of GCS, systolic blood pressure and age to predict the outcome of patients with decreased consciousness. This was a retrospective cohort observational study of 76 loss of consciousness patients that comes into the Emergency Department of Dr. Cipto Mangunkusumo General Hospital in June-August 2014. Data was obtained from the medical records . GCS, systolic blood pressure and age were recorded when patients were admitted to the triage. Outcome was assessed two weeks after admission in the emergency department. Bivariate analysis on the GCS and age showed significant different between patients with poor outcome group with good outcome group (p<0.05 and no significant different of the systolic blood pressure between both groups (p>0.05. Multivariate analysis on the GCS and age showed good probability equation based on the calibration test and discrimination. The combination of Glasgow Coma Scale and age was accurate in assessing the outcomes of patients with loss of consciousness. Keywords. Glasgow Coma Scale, systolic, age, outcomes     Gabungan Glasgow Coma Scale, Umur, dan Tekanan Darah Sistolik Sebagai Penilai Luaran Pasien Penurunan Kesadaran   Abstrak Glasgow Coma Scale (GCS telah menjadi salah satu penilaian yang digunakan untuk menilai luaran pasien penurunan kesadaran, tetapi dinilai masih belum mampu memprediksi luaran yang terjadi. Penelitian ini bertujuan untuk menilai gabungan GCS, tekanan darah sistolik dan umur untuk memprediksi luaran pasien dengan penurunan kesadaran. Penelitian ini merupakan studi observasional kohort retrospektif yang melibatkan 76 pasien dengan penurunan kesadaran yang datang ke IGD RSUPN Dr. Cipto Mangunkusumo selama bulan Juni-Agustus 2014. Data diambil dari rekam medik. GCS, tekanan darah sistolik dan

Looking Wider and Further: The Evolution of Galaxies Inside Galaxy Clusters

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuanyuan [Univ. of Michigan, Ann Arbor, MI (United States)

2016-01-01

Galaxy clusters are rare objects in the universe, but on-going wide field optical surveys are identifying many thousands of them to redshift 1.0 and beyond. Using early data from the Dark Energy Survey (DES) and publicly released data from the Sloan Digital Sky Survey (SDSS), this dissertation explores the evolution of cluster galaxies in the redshift range from 0 to 1.0. As it is common for deep wide field sky surveys like DES to struggle with galaxy detection efficiency at cluster core, the first component of this dissertation describes an efficient package that helps resolving the issue. The second part focuses on the formation of cluster galaxies. The study quantifies the growth of cluster bright central galaxies (BCGs), and argues for the importance of merging and intra-cluster light production during BCG evolution. An analysis of cluster red sequence galaxy luminosity function is also performed, demonstrating that the abundance of these galaxies is mildly dependent on cluster mass and redshift. The last component of the dissertation characterizes the properties of galaxy filaments to help understanding cluster environments

Galaxy Zoo: dust in spiral galaxies star

OpenAIRE

Masters, Karen L.; Nichol, Robert; Bamford, Steven; Mosleh, Moein; Lintott, Chris J.; Andreescu, Dan; Edmondson, Edward M.; Keel, William C.; Murray, Phil; Raddick, M. Jordan; Schawinski, Kevin; Slosar, Anze; Szalay, Alexander S.; Thomas, Daniel; Vandenberg, Jan

2010-01-01

We investigate the effect of dust on spiral galaxies by measuring the inclination dependence of optical colours for 24 276 well-resolved Sloan Digital Sky Survey (SDSS) galaxies visually classified via the Galaxy Zoo project. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4 mag for the ugri passbands (estimating 0.3 mag of extinction in z band). We split the sample into ‘bulgy’ (early-type) and ‘discy’ (late-typ...

A comparative study on assessment procedures and metric properties of two scoring systems of the Coma Recovery Scale-Revised items: standard and modified scores.

Science.gov (United States)

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.

Optical-to-virial velocity ratios of local disc galaxies from combined kinematics and galaxy-galaxy lensing

Science.gov (United States)

Reyes, R.; Mandelbaum, R.; Gunn, J. E.; Nakajima, R.; Seljak, U.; Hirata, C. M.

2012-10-01

In this paper, we measure the optical-to-virial velocity ratios Vopt/V200c of disc galaxies in the Sloan Digital Sky Survey (SDSS) at a mean redshift of = 0.07 and with stellar masses 109 < M* < 1011 M⊙. Vopt/V200c, the ratio of the circular velocity measured at the optical radius of the disc (˜10 kpc) to that at the virial radius of the dark matter halo (˜150 kpc), is a powerful observational constraint on disc galaxy formation. It links galaxies to their dark matter haloes dynamically and constrains the total mass profile of disc galaxies over an order of magnitude in length scale. For this measurement, we combine Vopt derived from the Tully-Fisher relation (TFR) from Reyes et al. with V200c derived from halo masses measured with galaxy-galaxy lensing. In anticipation of this combination, we use similarly selected galaxy samples for both the TFR and lensing analysis. For three M* bins with lensing-weighted mean stellar masses of 0.6, 2.7 and 6.5 × 1010 M⊙, we find halo-to-stellar mass ratios M200c/M* = 41, 23 and 26, with 1σ statistical uncertainties of around 0.1 dex, and Vopt/V200c = 1.27 ± 0.08, 1.39 ± 0.06 and 1.27 ± 0.08 (1σ), respectively. Our results suggest that the dark matter and baryonic contributions to the mass within the optical radius are comparable, if the dark matter halo profile has not been significantly modified by baryons. The results obtained in this work will serve as inputs to and constraints on disc galaxy formation models, which will be explored in future work. Finally, we note that this paper presents a new and improved galaxy shape catalogue for weak lensing that covers the full SDSS Data Release 7 footprint.

Monte Carlo particle-trajectory models for neutral cometary gases. I. Models and equations. II. The spatial morphology of the Lyman-alpha coma

International Nuclear Information System (INIS)

Combi, M.R.; Smyth, W.H.

1988-01-01

The mathematical derivations of various methods employed in the Monte Carlo particle-trajectory model (MCPTM) are presented, and the application of the MCPTM to the calculation of the photochemical heating of the inner coma through the partial thermalization of cometary hydrogen atoms produced by the photodissociation of water is discussed. This model is then used to explain the observed morphology of the spatially extended Ly-alpha comas of comets. The rocket and Skylab images of the Ly-alpha coma of Comet Kohoutek are examined. 90 references

Chorea--an unusual manifestation in a woman recovering from myxedema coma.

Science.gov (United States)

Yu, Catherine H Y; Stovel, Rebecca; Fox, Susan

2012-01-01

To report a case of reversible chorea in a woman with myxedema coma. We describe the clinical course, imaging findings, and laboratory test results of a patient who initially presented with myxedema coma and then developed reversible chorea upon treatment. A 33-year-old woman with a known history of primary hypothyroidism presented with a 3-week history of lethargy, progressing to a precipitous decline in consciousness that required intubation. Physical examination revealed concurrent hypothermia and bradycardia. Laboratory investigations demonstrated a thyrotropin concentration greater than 100 mIU/L, a free triiodothyronine concentration of 1.9 pg/mL, and a free thyroxine concentration of 0.24 ng/dL, but no other metabolic abnormalities. She was treated with intravenous levothyroxine therapy on the first 2 days of hospital admission (200 mcg and 250 mcg, respectively). On day 2, she was obeying commands and she was extubated. She began exhibiting choreiform movements. Thyroid function test results revealed a normal free thyroxine concentration (1.10 ng/dL), but an elevated thyrotropin concentration (40.98 mIU/L) and a low free triiodothyronine concentration (1.9 pg/mL). Findings from computed tomography and magnetic resonance imaging of her brain and analysis of cerebrospinal fluid were normal. Her regimen was transitioned to oral levothyroxine, 88 mcg daily, and by day 4, her choreiform movements ceased. Neurologic manifestations of hypothyroidism include psychomotor slowing, memory deficits, and dementia, with myxedema coma at the extreme of this spectrum. Although chorea is a rare manifestation of hyperthyroidism, this is the first report of a patient with acquired, reversible choreiform movement disorder while still being severely hypothyroid and treated with levothyroxine.

Delirium and coma evaluated in mechanically ventilated patients in the intensive care unit in Japan: a multi-institutional prospective observational study.

Science.gov (United States)

Tsuruta, Ryosuke; Oda, Yasutaka; Shintani, Ayumi; Nunomiya, Shin; Hashimoto, Satoru; Nakagawa, Takashi; Oida, Yasuhisa; Miyazaki, Dai; Yabe, Shigemi

2014-06-01

The object of this study is to evaluate the prevalence and effects of delirium on 28-day mortality in critically ill patients on mechanical ventilation in Japan. Prospective cohort study was conducted in medical and surgical intensive care units (ICUs) of 24 medical centers. Patients were followed up daily for delirium during ICU stay after enrollment. Coma was defined with the Richmond Agitation Sedation Scale score of -4 or -5. Delirium was diagnosed using the Confusion Assessment Method for the ICU. The Cox proportional hazards regression model was used to assess the effects of delirium and coma on 28-day mortality, time to extubation, and time to ICU discharge; delirium and coma were included as time-varying covariates after controlling for age, Acute Physiology and Chronic Health Evaluation II score, ventilator-associated pneumonia, and the reason for intubation with infection. Of 180 patients, 115 patients (64%) developed delirium. Moreover, 15 patients (8%) died within 28 days after ICU admission, including 7 patients who experienced coma and 8 patients who experienced both coma and delirium. There were no deaths among patients who did not experience coma. Delirium was associated with a shorter time to extubation (hazard ratio [HR], 2.52; 95% confidence interval [CI], 1.65-3.85; Pcoma, although statistical significance was not detected due to limited analytical power (HR, 0.62; 95% CI, 0.34-1.12; P=.114). Delirium during ICU stay was not associated with higher mortality. Further study is needed to investigate the discrepancy between these and previous data. Copyright © 2014 Elsevier Inc. All rights reserved.

Photometric redshift requirements for lens galaxies in galaxy-galaxy lensing analyses

Science.gov (United States)

Nakajima, R.; Mandelbaum, R.; Seljak, U.; Cohn, J. D.; Reyes, R.; Cool, R.

2012-03-01

Weak gravitational lensing is a valuable probe of galaxy formation and cosmology. Here we quantify the effects of using photometric redshifts (photo-z) in galaxy-galaxy lensing, for both sources and lenses, both for the immediate goal of using galaxies with photo-z as lenses in the Sloan Digital Sky Survey (SDSS) and as a demonstration of methodology for large, upcoming weak lensing surveys that will by necessity be dominated by lens samples with photo-z. We calculate the bias in the lensing mass calibration as well as consequences for absolute magnitude (i.e. k-corrections) and stellar mass estimates for a large sample of SDSS Data Release 8 (DR8) galaxies. The redshifts are obtained with the template-based photo-z code ZEBRA on the SDSS DR8 ugriz photometry. We assemble and characterize the calibration samples (˜9000 spectroscopic redshifts from four surveys) to obtain photometric redshift errors and lensing biases corresponding to our full SDSS DR8 lens and source catalogues. Our tests of the calibration sample also highlight the impact of observing conditions in the imaging survey when the spectroscopic calibration covers a small fraction of its footprint; atypical imaging conditions in calibration fields can lead to incorrect conclusions regarding the photo-z of the full survey. For the SDSS DR8 catalogue, we find σΔz/(1+z)= 0.096 and 0.113 for the lens and source catalogues, with flux limits of r= 21 and 21.8, respectively. The photo-z bias and scatter is a function of photo-z and template types, which we exploit to apply photo-z quality cuts. By using photo-z rather than spectroscopy for lenses, dim blue galaxies and L* galaxies up to z˜ 0.4 can be used as lenses, thus expanding into unexplored areas of parameter space. We also explore the systematic uncertainty in the lensing signal calibration when using source photo-z, and both lens and source photo-z; given the size of existing training samples, we can constrain the lensing signal calibration (and

Near-death experiences in non-life-threatening events and coma of different etiologies

Directory of Open Access Journals (Sweden)

Vanessa eCharland-Verville

2014-05-01

Full Text Available Background: Near death experiences (NDEs are increasingly being reported as a clearly identifiable physiological and psychological reality of clinical significance. However, the definition and causes of the phenomenon as well as the identification of NDE experiencers is still a matter of debate. To date, the most widely used standardized tool to identify and characterize NDEs in research is the Greyson NDE Scale. Using this scale, retrospective and prospective studies have been trying to estimate their incidence in various populations but few studies have tackled to associate the experiences’ intensity and content related to etiology. Methods: This retrospective investigation assessed the most frequently recounted features of self-reported NDEs after a non-life-threatening event (i.e., NDE-like experience or after a pathological coma (i.e., classical NDEs and according to the etiology of the acute brain insult. We also compared our retrospectively acquired data in anoxic coma with historical data from the published literature on prospective post-anoxic studies using the Greyson NDE Scale. Results: From our 190 reports who met the criteria for NDE (i.e., NDE scale total score Conclusions: It appears that real NDEs after coma of different etiologies are similar to NDE-like experiences occurring after non-life threatening events. Subjects reporting NDEs retrospectively tend to have experienced a different content compared to the prospective experiencers

Visibility of galaxies

International Nuclear Information System (INIS)

Disney, M.J.

1976-01-01

It is stated that counts of galaxies could be seriously biased by selection effects, largely influenced by the brightness of the night sky. To illustrate this suppose the Earth were situated near the center of a giant elliptical galaxy. The mean surface brightness of the sky would then appear some 8 to 9 mag. brighter than is observed from our position in the Galaxy. Extragalactic space would then appear to be empty void; spiral and irregular galaxies would be invisible, and all that could be easily detected would be the core regions of galaxy ellipticals very similar to our own. Much of the Universe would be blinded by the surface brightness of the parent galaxy. This blinding, however, is a relative matter and the question arises as to what extent we are blinded by the spiral galaxy in which we exist. Strong indirect evidence exists that our knowledge of galaxies is heavily biased by the sky background, and the true population of extragalactic space may be very different from that seen. Other relevant work is also discussed, and further investigational work is indicated. (U.K.)

Strong bimodality in the host halo mass of central galaxies from galaxy-galaxy lensing

Science.gov (United States)

Mandelbaum, Rachel; Wang, Wenting; Zu, Ying; White, Simon; Henriques, Bruno; More, Surhud

2016-04-01

We use galaxy-galaxy lensing to study the dark matter haloes surrounding a sample of locally brightest galaxies (LBGs) selected from the Sloan Digital Sky Survey. We measure mean halo mass as a function of the stellar mass and colour of the central galaxy. Mock catalogues constructed from semi-analytic galaxy formation simulations demonstrate that most LBGs are the central objects of their haloes, greatly reducing interpretation uncertainties due to satellite contributions to the lensing signal. Over the full stellar mass range, 10.3 10.7. Tests using the mock catalogues and on the data themselves clarify the effects of LBG selection and show that it cannot artificially induce a systematic dependence of halo mass on LBG colour. The bimodality in halo mass at fixed stellar mass is reproduced by the astrophysical model underlying our mock catalogue, but the sign of the effect is inconsistent with recent, nearly parameter-free age-matching models. The sign and magnitude of the effect can, however, be reproduced by halo occupation distribution models with a simple (few-parameter) prescription for type dependence.

Ultraviolet Extinction in Backlit Galaxies - from Galaxy Zoo to GALEX

Science.gov (United States)

Keel, William C.; Manning, A.; Holwerda, B. W.; Lintott, C.; Schawinski, K.; Galaxy Zoo Team

2012-01-01

We examine the ultraviolet extinction of galaxies on large scales, combining optical and GALEX UV data on backlit galaxies (most found in the Galaxy Zoo citizen-science project). We analyze the images in matching ways, modelling both foreground and background galaxies by symmetry or elliptical isophote families as appropriate, and using the non-overlapping regions of the galaxies to estimate errors in the derived transmission T=e-κ. Spirals appear less symmetric in the UV, as star-forming regions become more dominant, so that our most reliable results are mean values across multiple regions and multiple galaxies. Our mean effective extinction curve is dominated by the contribution of luminous spirals,and shows a fairly flat gray" extinction law into the ultraviolet. For example, the median of κNUV/κB in spiral arms is only 1.3. Along with previous high-resolution HST studies of a few nearby backlit galaxies, this suggests that on kpc scales the effective extinction is dominated by the dust clumping rather than the intrinsic reddening law. This implies that extrapolation of local properties to short wavelengths, a step toward the history of dust in galaxies through comparison of local properties with a similar analysis in deep HST fields, can be done without introducing much additional error. This work was supported by NASA Astrophysics Data Analysis Program grant NNX10AD54G.

Prognosis of non traumatic coma: The role of some socio-economic ...

African Journals Online (AJOL)

Background : Coma occurring in the course of an illness, irrespective of cause, traditionally implies a poor prognosis and many factors may determine its outcome. These factors must be identified and possibly stratified in their order of importance. This research seeks to identify these factors and how they influenced the ...

Myxedema coma of both primary and secondary origin, with non-classic presentation and extremely elevated creatine kinase.

Science.gov (United States)

Benvenga, S; Squadrito, S; Saporito, F; Cimino, A; Arrigo, F; Trimarchi, F

2000-09-01

Myxedema coma is a rare, often fatal endocrine emergency that concerns elderly patients with long-standing primary hypothyroidism; myxedema coma of central origin is exceedingly rare. Here, we report a 37-year-old woman in whom classical symptoms of hypothyroidism had been absent. Six years earlier, she had severe obstetric hemorrhage and, shortly after, two subsequent episodes of pericardial effusion. On the day of admission, pericardiocentesis was performed for the third episode of pericardial effusion. Because of the subsequent grave arrhythmias and unconsciousness, she was transferred to our ICU. Prior to the endocrine consultation, a silent myocardial infarction had been suspected, based on the extremely high serum levels of creatine kinase (CK) and isoenzyme CK-MB. However, based on thyroid sonography, pituitary computed tomography, elevated titers of antithyroid antibodies and pituitary stimulation tests, the final diagnosis was myxedema coma of dual origin: an atrophic variant of Hashimoto's thyroiditis and post-necrotic pituitary atrophy (Sheehan syndrome). Substitutive therapy caused a prompt clinical amelioration and normalization of CK levels. Our patient is the first case of myxedema coma of double etiology, and illustrates how its presentation deviates markedly from the one endocrinologists and physicians at ICU are prepared to encounter. In addition, cardiac problems as those of our patient should not discourage from substitutive treatment (using L-thyroxine and the gastrointestinal route of absorption), if the age is relatively low.

Economic evaluation of decompressive craniectomy versus barbiturate coma for refractory intracranial hypertension following traumatic brain injury.

Science.gov (United States)

Alali, Aziz S; Naimark, David M J; Wilson, Jefferson R; Fowler, Robert A; Scales, Damon C; Golan, Eyal; Mainprize, Todd G; Ray, Joel G; Nathens, Avery B

2014-10-01

Decompressive craniectomy and barbiturate coma are often used as second-tier strategies when intracranial hypertension following severe traumatic brain injury is refractory to first-line treatments. Uncertainty surrounds the decision to choose either treatment option. We investigated which strategy is more economically attractive in this context. We performed a cost-utility analysis. A Markov Monte Carlo microsimulation model with a life-long time horizon was created to compare quality-adjusted survival and cost of the two treatment strategies, from the perspective of healthcare payer. Model parameters were estimated from the literature. Two-dimensional simulation was used to incorporate parameter uncertainty into the model. Value of information analysis was conducted to identify major drivers of decision uncertainty and focus future research. Trauma centers in the United States. Base case was a population of patients (mean age = 25 yr) who developed refractory intracranial hypertension following traumatic brain injury. We compared two treatment strategies: decompressive craniectomy and barbiturate coma. Decompressive craniectomy was associated with an average gain of 1.5 quality-adjusted life years relative to barbiturate coma, with an incremental cost-effectiveness ratio of $9,565/quality-adjusted life year gained. Decompressive craniectomy resulted in a greater quality-adjusted life expectancy 86% of the time and was more cost-effective than barbiturate coma in 78% of cases if our willingness-to-pay threshold is $50,000/quality-adjusted life year and 82% of cases at a threshold of $100,000/quality-adjusted life year. At older age, decompressive craniectomy continued to increase survival but at higher cost (incremental cost-effectiveness ratio = $197,906/quality-adjusted life year at mean age = 85 yr). Based on available evidence, decompressive craniectomy for the treatment of refractory intracranial hypertension following traumatic brain injury provides better

Extending technology-aided leisure and communication programs to persons with spinal cord injury and post-coma multiple disabilities.

Science.gov (United States)

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Ricciuti, Riccardo A; Trignani, Roberto; Oliva, Doretta; Signorino, Mario; D'Amico, Fiora; Sasanelli, Giovanni

2015-01-01

These two studies extended technology-aided programs to promote leisure and communication opportunities to a man with cervical spinal cord injury and a post-coma man with multiple disabilities. The studies involved the use of ABAB designs, in which A and B represented baseline and intervention phases, respectively. The programs focused on enabling the participants to activate songs, videos, requests, text messages, and telephone calls. These options were presented on a computer screen and activated through a small pressure microswitch by the man with spinal cord injury and a special touch screen by the post-coma man. To help the latter participant, who had no verbal skills, with requests and telephone calls, series of words and phrases were made available that he could activate in those situations. Data showed that both participants were successful in managing the programs arranged for them. The man with spinal cord injury activated mean frequencies of above five options per 10-min session. The post-coma man activated mean frequencies of about 12 options per 20-min session. Technology-aided programs for promoting leisure and communication opportunities might be successfully tailored to persons with spinal cord injury and persons with post-coma multiple disabilities. Implications for Rehabilitation Technology-aided programs may be critical to enable persons with pervasive motor impairment to engage in leisure activities and communication events independently. Persons with spinal cord injury, post-coma extended brain damage, and forms of neurodegenerative disease, such as amyotrophic lateral sclerosis, may benefit from those programs. The programs could be adapted to the participants' characteristics, both in terms of technology and contents, so as to improve their overall impact on the participants' functioning and general mood.

Crashing galaxies, cosmic fireworks

International Nuclear Information System (INIS)

Keel, W.C.

1989-01-01

The study of binary systems is reviewed. The history of the study of interacting galaxies, the behavior of gas in binary systems, studies to identify the processes that occur when galaxies interact, and the relationship of Seyfert galaxies and quasars to binary systems are discussed. The development of an atlas of peculiar galaxies (Arp, 1966) and methods for modeling galaxy interactions are examined

Modeling of the VIRTIS-M Observations of the Coma of Comet 67P/Churyumov-Gerasimenko

Science.gov (United States)

Fougere, Nicolas; Combi, Michael R.; Tenishev, Valeriy; Bieler, Andre; Migliorini, Alessandra; Piccioni, Giuseppe; Capaccioni, Fabrizio; Filacchione, Gianrico; Toth, Gabor; Huang, Zhenguang; Gombosi, Tamas; Hansen, Kenneth; Bockelee-Morvan, Dominique; Debout, Vincent; Erard, Stephane; Leyrat, Cedric; Fink, Uwe; Rubin, Martin; Altwegg, Kathrin; Tzou, Chia-Yu; Le Roy, Lena; Calmonte, Ursina; Berthelier, Jean-Jacques; Reme, Henri; Hassig, Myrtha; Fuselier, Stephen; Fiethe, Bjorn; De Keyser, Johan

2015-11-01

The recent images of the inner coma of 67P/Churyumov-Gerasimenko (CG) made by the infrared channel of the VIRTIS-M instrument on board the Rosetta spacecraft show the gas distribution as it expands in the coma (Migliorini et al. 2015, DPS abstract).Since VIRTIS is a remote sensing instrument, a proper modeling of these observations requires the computation of the full coma of comet CG, which necessitates the use of a kinetic approach due to the rather low gas densities. Hence, we apply a Direct Simulation Monde Carlo (DSMC) method to solve the Boltzmann equation and describe CG’s coma from the nucleus surface up to a few hundreds of kilometers. The model uses the SHAP5 nucleus shape model from the OSIRIS team. The gas flux distribution takes into account solar illumination, including self-shadowing. The local activity at the surface of the nucleus is given by spherical harmonics expansion reproducing best the ROSINA-DFMS data. The densities from the DSMC model outputs are then integrated along the line-of-sight to create synthetic images that are directly comparable with the VIRTIS-M column density measurements.The good agreement between the observations and the model illustrates our continuously improving understanding of the physics of the coma of comet CG.AcknowledgementsWork at UofM was supported by contracts JPL#1266313, JPL#1266314 and NASA grant NNX09AB59G. Work at UoB was funded by the State of Bern, the Swiss National Science Foundation and by the European Space Agency PRODEX Program. Work at Southwest Research institute was supported by subcontract #1496541 from the JPL. Work at BIRA-IASB was supported by the Belgian Science Policy Office via PRODEX/ROSINA PEA 90020. The authors would like to thank ASI, CNES, DLR, NASA for supporting this research. VIRTIS was built by a consortium formed by Italy, France and Germany, under the scientific responsibility of the IAPS of INAF, which guides also the scientific operations. The consortium includes also the

Chinese calligraphy handwriting (CCH: a case of rehabilitative awakening of a coma patient after stroke

Directory of Open Access Journals (Sweden)

Kao HSR

2018-01-01

Full Text Available Henry SR Kao,1 Stewart PW Lam,2 Tin Tin Kao3,4 1Calligraphy Therapy Laboratory, Shenzhen Institute of Neuroscience, Shenzhen, China; 2Research and Development Division, Calli-Health Society, 3Department of Geography, 4Department of Psychology, University of Hong Kong, Hong Kong Introduction: This study investigated the efficacy of Chinese calligraphy handwriting (CCH for the awakening of patients under a vegetative state after stroke. The theories, the instrument, and the treatment protocols were reported. A single case of a severe stroke patient who was in a coma state for 2 years is presented in this study. The objectives were to apply finger writing as a new method to awaken a stroke patient in a coma state and to test the effect of this method in improving the patient’s vegetative states over time. Case presentation: A 55-year-old man suffered a severe stroke in 2004 which left him in a coma for 2 years without any systematic rehabilitation. A culture-based finger-writing method of visual-spatial intervention was then applied to improve his condition. The writing tasks involved aided viewing and finger tracing of sets of innovative characters with enriched visual-spatial and movement characteristics. Following regular treatment protocols involving diverse movement and sensory feedback, the patient was awakened after 12 months. As a consequence, the patient showed significant behavioral changes favoring enhanced focusing, alertness, visual scan, visual span, and quickened visual and motor responses. The treatment continued for another 12 months. As the treatment progressed, we gradually observed improvements in his attention span and mental concentration. His eye ball movements – the left eye in particular – were quickened and showed wider visual angularity in his focal vision. Currently, the patient can now watch television, engage in improved visual sighting, and focus on visual-spatial and cognitive-linguistic materials. Conclusion

Intubation is not a marker for coma after in-hospital cardiac arrest: A retrospective study.

Science.gov (United States)

Berg, Katherine M; Grossestreuer, Anne V; Uber, Amy; Patel, Parth V; Donnino, Michael W

2017-10-01

In-hospital cardiac arrest (IHCA) strikes over 200,000 people in the United States annually. Targeted temperature management (TTM) is considered beneficial in other settings, but there is no prospective data for IHCA. Recent work on TTM and IHCA found an association between TTM and worse outcome. However, the authors used intubation as a marker for coma to determine eligibility for TTM. The validity of this approach is unexplored. Retrospective, single center study of adult patients with IHCA occurring in an intensive care unit, intubated prior to or during the event, or immediately after ROSC. We evaluated the percentage of patients documented as comatose after arrest, defined as Glasgow Comas Score (GCS) <8 for the primary analysis. We also evaluated the difference in hospital survival in patients with GCS <8 versus ≥8. Two sensitivity analyses using different methods for defining coma using post-ROSC GCS were conducted. 29/102 (28%) intubated patients had a post-ROSC GCS≥8, and 22 (22%) were documented as following commands. Survival in patients with GCS≥8 vs.<8 was 62% (18/29) vs. 37% (27/73) in unadjusted analysis (p=0.02). The adjusted odds ratio for survival to hospital discharge was 3.81 (95%CI: 1.37-10.61, p=0.01). Results were similar in both sensitivity analyses. Intubation prior to or during IHCA was not a valid marker of coma after ROSC. Post-ROSC mental status was associated with hospital survival, and thus could be an important confounder when conducting observational studies on the association of TTM with outcomes in this patient population. Copyright © 2017 Elsevier B.V. All rights reserved.

SPATIAL ANISOTROPY OF GALAXY KINEMATICS IN SLOAN DIGITAL SKY SURVEY GALAXY CLUSTERS

International Nuclear Information System (INIS)

Skielboe, Andreas; Wojtak, Radosław; Pedersen, Kristian; Rozo, Eduardo; Rykoff, Eli S.

2012-01-01

Measurements of galaxy cluster kinematics are important in understanding the dynamical state and evolution of clusters of galaxies, as well as constraining cosmological models. While it is well established that clusters exhibit non-spherical geometries, evident in the distribution of galaxies on the sky, azimuthal variations of galaxy kinematics within clusters have yet to be observed. Here we measure the azimuthal dependence of the line-of-sight velocity dispersion profile in a stacked sample of 1743 galaxy clusters from the Sloan Digital Sky Survey (SDSS). The clusters are drawn from the SDSS DR8 redMaPPer catalog. We find that the line-of-sight velocity dispersion of galaxies lying along the major axis of the central galaxy is larger than those that lie along the minor axis. This is the first observational detection of anisotropic kinematics of galaxies in clusters. We show that the result is consistent with predictions from numerical simulations. Furthermore, we find that the degree of projected anisotropy is strongly dependent on the line-of-sight orientation of the galaxy cluster, opening new possibilities for assessing systematics in optical cluster finding.

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

Science.gov (United States)

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.

Tidal interaction of galaxies

International Nuclear Information System (INIS)

Kozlov, N.N.; Syunyaev, R.A.; Ehneev, T.M.

1974-01-01

One of the hypotheses explaining the occurrence of anomalous details in interacting galaxies has been investigated. Pairs of galaxies with 'tails' oppositely directed or neighbouring galaxies with cofferdams 'bridges', as if connecting the galaxies, are called interacting galaxies. The hypothesis connects the origin of cofferdams and 'tails' of interacting galaxies with tidal effects ; the action of power gravitational forces in the intergalactic space. A source of such forces may be neighbouring stellar systems or invisible bodies, for instance, 'dead' quasars after a gravitational collapse. The effect of large masses of matter on the galaxy evolution has been investigated in the Institute of Applied Mathematics of the Academy of Sciences of the USSSR in 1971-1972 by numerical simulation of the process on a digital computer with the subsequent data transmission on a display. Different versions of a massive body flight relative to a galaxy disk are considered. Photographs of a display screen at different moments of time are presented. As a result of mathematical simulation of galaxies gravitational interactions effects are discovered which resemble real structures in photographs of galaxies. It seems to be premature to state that namely these mechanisms cause the formation of 'tails' and cofferdams between galaxies. However, even now it is clear that the gravitational interaction strongly affects the dynamics of the stellar system evolution. Further studies should ascertain a true scale of this effect and its genuine role in galaxy evolution

A case report on near manual strangulation and glasgow coma scale.

African Journals Online (AJOL)

Abstract. Background: Glasgow Coma Scale (GCS) is considered as a gold standard in estimating the prognosis of the comatose patient. The management of the patient relies heavily on this scale. The mechanism of injury must also be included in scor- ing of the GCS. Survival from strangulation is uncommon, and if it ...

Heart failure presenting as myxedema coma: case report and review article.

Science.gov (United States)

Chaudhari, Dhara; Gangadharan, Venkat; Forrest, Terry

2013-05-01

Hypothyroidism is a common medical problem easily treated when diagnosed but requiring regular follow-up and patient medication compliance. At times, this diagnosis can go untreated resulting in the development of severe consequences such as Myxedema Coma. Of all the clinical symptoms, cardiovascular manifestations tend to be especially severe and often life threatening.

Nearby Galaxies: Templates for Galaxies Across Cosmic Time

OpenAIRE

Lockman, F. J.; Ott, J.

2009-01-01

Studies of nearby galaxies including the Milky Way have provided fundamental information on the evolution of structure in the Universe, the existence and nature of dark matter, the origin and evolution of galaxies, and the global features of star formation. Yet despite decades of work, many of the most basic aspects of galaxies and their environments remain a mystery. In this paper we describe some outstanding problems in this area and the ways in which large radio facilities will contribute ...

Galaxy Cluster Outskirts from the Thermal SZ and Non-Thermal Synchrotron Link

Directory of Open Access Journals (Sweden)

Kaustuv Basu

2016-11-01

Full Text Available Galaxy cluster merger shocks are the main agent for the thermalization of the intracluster medium and the energization of cosmic ray particles in it. Shock propagation changes the state of the tenuous intracluster plasma, and the corresponding signal variations are measurable with the current generation of X-ray and Sunyaev–Zel’dovich (SZ effect instruments. Additionally, non-thermal electrons (re-energized by the shocks sometimes give rise to extended and luminous synchrotron sources known as radio relics, which are prominent indicators of shocks propagating roughly in the plane of the sky. In this short review, we discuss how the joint modeling of the non-thermal and thermal signal variations across radio relic shock fronts is helping to advance our knowledge of the gas thermodynamical properties and magnetic field strengths in the cluster outskirts. We describe the first use of the SZ effect to measure the Mach numbers of relic shocks, for both the nearest (Coma and the farthest (El Gordo clusters with known radio relics.

Brain connectivity in pathological and pharmacological coma

Directory of Open Access Journals (Sweden)

Quentin Noirhomme

2010-12-01

Full Text Available Recent studies in patients with disorders of consciousness (DOC tend to support the view that awareness is not related to activity in a single brain region but to thalamo-cortical connectivity in the frontoparietal network. Functional neuroimaging studies have shown preserved albeit disconnected low level cortical activation in response to external stimulation in patients in a vegetative state or unresponsive wakefulness syndrome. While activation of these primary sensory cortices does not necessarily reflect conscious awareness, activation in higher order associative cortices in minimally conscious state patients seems to herald some residual perceptual awareness. PET studies have identified a metabolic dysfunction in a widespread fronto-parietal global neuronal workspace in DOC patients including the midline default mode network, ‘intrinsic’ system, and the lateral frontoparietal cortices or ‘extrinsic system’. Recent studies have investigated the relation of awareness to the functional connectivity within intrinsic and extrinsic networks, and with the thalami in both pathological and pharmacological coma. In brain damaged patients, connectivity in all default network areas was found to be non-linearly correlated with the degree of clinical consciousness impairment, ranging from healthy controls and locked-in syndrome to minimally conscious, vegetative, coma and brain dead patients. Anesthesia-induced loss of consciousness was also shown to correlate with a global decrease in cortico-cortical and thalamo-cortical connectivity in both intrinsic and extrinsic networks, but not in auditory or visual networks. In anesthesia, unconsciousness was also associated with a loss of cross-modal interactions between networks. These results suggest that conscious awareness critically depends on the functional integrity of thalamo-cortical and cortico-cortical frontoparietal connectivity within and between intrinsic and extrinsic brain networks.

GALAXY ENVIRONMENTS OVER COSMIC TIME: THE NON-EVOLVING RADIAL GALAXY DISTRIBUTIONS AROUND MASSIVE GALAXIES SINCE z = 1.6

International Nuclear Information System (INIS)

Tal, Tomer; Van Dokkum, Pieter G.; Leja, Joel; Franx, Marijn; Wake, David A.; Whitaker, Katherine E.

2013-01-01

We present a statistical study of the environments of massive galaxies in four redshift bins between z = 0.04 and z = 1.6, using data from the Sloan Digital Sky Survey and the NEWFIRM Medium Band Survey. We measure the projected radial distribution of galaxies in cylinders around a constant number density selected sample of massive galaxies and utilize a statistical subtraction of contaminating sources. Our analysis shows that massive primary galaxies typically live in group halos and are surrounded by 2-3 satellites with masses more than one-tenth of the primary galaxy mass. The cumulative stellar mass in these satellites roughly equals the mass of the primary galaxy itself. We further find that the radial number density profile of galaxies around massive primaries has not evolved significantly in either slope or overall normalization in the past 9.5 Gyr. A simplistic interpretation of this result can be taken as evidence for a lack of mergers in the studied groups and as support for a static evolution model of halos containing massive primaries. Alternatively, there exists a tight balance between mergers and accretion of new satellites such that the overall distribution of galaxies in and around the halo is preserved. The latter interpretation is supported by a comparison to a semi-analytic model, which shows a similar constant average satellite distribution over the same redshift range.

Galaxy Formation

CERN Document Server

Longair, Malcolm S

2008-01-01

This second edition of Galaxy Formation is an up-to-date text on astrophysical cosmology, expounding the structure of the classical cosmological models from a contemporary viewpoint. This forms the background to a detailed study of the origin of structure and galaxies in the Universe. The derivations of many of the most important results are derived by simple physical arguments which illuminate the results of more advanced treatments. A very wide range of observational data is brought to bear upon these problems, including the most recent results from WMAP, the Hubble Space Telescope, galaxy surveys like the Sloan Digital Sky Survey and the 2dF Galaxy Redshift Survey, studies of Type 1a supernovae, and many other observations.

Automatic Approach to Morphological Classification of Galaxies With Analysis of Galaxy Populations in Clusters

Science.gov (United States)

Sultanova, Madina; Barkhouse, Wayne; Rude, Cody

2018-01-01

The classification of galaxies based on their morphology is a field in astrophysics that aims to understand galaxy formation and evolution based on their physical differences. Whether structural differences are due to internal factors or a result of local environment, the dominate mechanism that determines galaxy type needs to be robustly quantified in order to have a thorough grasp of the origin of the different types of galaxies. The main subject of my Ph.D. dissertation is to explore the use of computers to automatically classify and analyze large numbers of galaxies according to their morphology, and to analyze sub-samples of galaxies selected by type to understand galaxy formation in various environments. I have developed a computer code to classify galaxies by measuring five parameters from their images in FITS format. The code was trained and tested using visually classified SDSS galaxies from Galaxy Zoo and the EFIGI data set. I apply my morphology software to numerous galaxies from diverse data sets. Among the data analyzed are the 15 Abell galaxy clusters (0.03 Frontier Field galaxy clusters. The high resolution of HST allows me to compare distant clusters with those nearby to look for evolutionary changes in the galaxy cluster population. I use the results from the software to examine the properties (e.g. luminosity functions, radial dependencies, star formation rates) of selected galaxies. Due to the large amount of data that will be available from wide-area surveys in the future, the use of computer software to classify and analyze the morphology of galaxies will be extremely important in terms of efficiency. This research aims to contribute to the solution of this problem.

The group environment of Seyfert galaxies. II. Spectrophotometry of galaxies in groups

International Nuclear Information System (INIS)

Fricke, K.J.; Kollatschny, W.

1989-01-01

Medium-resolution spectrophotometric data of 104 galaxies have been obtained. These galaxies are members of 22 loose groups of < 1 Mpc size. Thirteen of these groups contain Seyfert galaxies. In this paper we present calibrated emission-line data and absolute optical spectra of the individual galaxies as well as plates of each group

Isothermality of the gas in the Coma cluster

International Nuclear Information System (INIS)

Hughes, J.P.; Yamashita, K.; Okumura, Y.; Tsunemi, H.; Matsuoka, M.

1988-01-01

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

Factors predisposing to coma and delirium: fentanyl and midazolam exposure; CYP3A5, ABCB1, and ABCG2 genetic polymorphisms; and inflammatory factors.

Science.gov (United States)

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

GalaxyGAN: Generative Adversarial Networks for recovery of galaxy features

Science.gov (United States)

Schawinski, Kevin; Zhang, Ce; Zhang, Hantian; Fowler, Lucas; Krishnan Santhanam, Gokula

2017-02-01

GalaxyGAN uses Generative Adversarial Networks to reliably recover features in images of galaxies. The package uses machine learning to train on higher quality data and learns to recover detailed features such as galaxy morphology by effectively building priors. This method opens up the possibility of recovering more information from existing and future imaging data.

A Spanish validation of the Coma Recovery Scale-Revised (CRS-R).

Science.gov (United States)

Tamashiro, Mercedes; Rivas, Maria Elisa; Ron, Melania; Salierno, Fernando; Dalera, Marisol; Olmos, Lisandro

2014-01-01

Analysis of inter-rater reliability and concurrent validity. To determine measurement properties of a Spanish version of The Coma Recovery Scale-Revised (CRS-R). A sample of 35 in-patients with severe acquired brain injury. To test concurrent validity of the translated scale, the Glasgow Coma Scale (GSC) and Disability Rating Scale (DRS) were also administered. Two experts in the field were recruited to assess inter-rater agreement. Inter-rater reliability was good for total CRS-R scores (Cronbach α = 0.973, p = 0.001). Sub-scale analysis showed moderate-to-high inter-rater agreement. Total CRS-R scores correlated significantly (p < 0.05) with total GCS (r = 0.74) and DRS (r = 0.54) scores, indicating acceptable concurrent validity. The Spanish version of CRS-R can be administered reliably by trained and experienced examiners. CRS-R appears capable of differentiating patients in Emergence from Minimally Conscious State (EMCS) or in Minimally Conscious State (MCS) from those in a Vegetative State (VS).

A NuSTAR OBSERVATION OF THE CENTER OF THE COMA CLUSTER

Energy Technology Data Exchange (ETDEWEB)

Gastaldello, Fabio; Molendi, S. [IASF-Milano, INAF, Via Bassini 15, I-20133 Milan (Italy); Wik, Daniel R.; Zhang, W. W. [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Westergaard, N. J.; Hornstrup, A.; Ferreira, D. D. M.; Christensen, F. E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Madejski, G. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Grefenstette, B. W.; Harrison, F. A.; Madsen, K. K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Stern, D., E-mail: gasta@lambrate.inaf.it [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

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 of 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.

Predicting galaxy star formation rates via the co-evolution of galaxies and haloes

Science.gov (United States)

Watson, Douglas F.; Hearin, Andrew P.; Berlind, Andreas A.; Becker, Matthew R.; Behroozi, Peter S.; Skibba, Ramin A.; Reyes, Reinabelle; Zentner, Andrew R.; van den Bosch, Frank C.

2015-01-01

In this paper, we test the age matching hypothesis that the star formation rate (SFR) of a galaxy of fixed stellar mass is determined by its dark matter halo formation history, e.g. more quiescent galaxies reside in older haloes. We present new Sloan Digital Sky Survey measurements of the galaxy two-point correlation function and galaxy-galaxy lensing as a function of stellar mass and SFR, separated into quenched and star-forming galaxy samples to test this simple model. We find that our age matching model is in excellent agreement with these new measurements. We also find that our model is able to predict: (1) the relative SFRs of central and satellite galaxies, (2) the SFR dependence of the radial distribution of satellite galaxy populations within galaxy groups, rich groups, and clusters and their surrounding larger scale environments, and (3) the interesting feature that the satellite quenched fraction as a function of projected radial distance from the central galaxy exhibits an ˜r-.15 slope, independent of environment. These accurate predictions are intriguing given that we do not explicitly model satellite-specific processes after infall, and that in our model the virial radius does not mark a special transition region in the evolution of a satellite. The success of the model suggests that present-day galaxy SFR is strongly correlated with halo mass assembly history.

The galaxy builders

Science.gov (United States)

Cho, Adrian

2018-06-01

Philip Hopkins, a theoretical astrophysicist at the California Institute of Technology in Pasadena, likes to prank his colleagues. An expert in simulating the formation of galaxies, Hopkins sometimes begins his talks by projecting images of his creations next to photos of real galaxies and defying his audience to tell them apart. "We can even trick astronomers," Hopkins says. For decades, scientists have tried to simulate how the trillions of galaxies in the observable universe arose from clouds of gas after the big bang. But only in the past few years have the simulations begun to reproduce both the details of individual galaxies and their distribution of masses and shapes. As the fake universes improve, their role is also changing. Previously, information flowed one way: from the astronomers studying real galaxies to the modelers trying to simulate them. Now, insight is flowing the other way, too, with the models helping guide astronomers and astrophysicists. The models suggest that the earliest galaxies were oddly pickle-shaped, that wafer-thin spiral galaxies are surprisingly rugged in the face of collisions, and, perhaps most important, that galaxies must form stars far more slowly than astrophysicists expected. Progress is coming so fast, says Tiziana Di Matteo, a numerical cosmologist at Carnegie Mellon University in Pittsburgh, Pennsylvania, that "the whole thing has reached this little golden age."

Secular evolution of galaxies and galaxy clusters in decaying dark matter cosmology

International Nuclear Information System (INIS)

Ferrer, Francesc; Nipoti, Carlo; Ettori, Stefano

2009-01-01

If the dark matter sector in the Universe is composed by metastable particles, galaxies and galaxy clusters are expected to undergo significant secular evolution from high to low redshift. We show that the decay of dark matter, with a lifetime compatible with cosmological constraints, can be at the origin of the observed evolution of the Tully-Fisher relation of disk galaxies and alleviate the problem of the size evolution of elliptical galaxies, while being consistent with the current observational constraints on the gas fraction of clusters of galaxies.

The Arecibo Galaxy Environment Survey IX: the isolated galaxy sample

Czech Academy of Sciences Publication Activity Database

Minchin, R.F.; Auld, R.; Davies, J.I.; Karachentsev, I.D.; Keenan, O.; Momjian, E.; Rodriguez, R.; Taber, T.; Taylor, Rhys

2016-01-01

Roč. 455, č. 4 (2016), s. 3430-3435 ISSN 0035-8711 R&D Projects: GA MŠk LG14013; GA ČR GAP209/12/1795 Institutional support: RVO:67985815 Keywords : individual galaxies NGC 1156 * individual galaxies NGC 5523 * individual galaxies UGC 2082 Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.961, year: 2016

Brain MRS glutamine as a biomarker to guide therapy of hyperammonemic coma.

Science.gov (United States)

O'Donnell-Luria, Anne H; Lin, Alexander P; Merugumala, Sai K; Rohr, Frances; Waisbren, Susan E; Lynch, Rebecca; Tchekmedyian, Vatche; Goldberg, Aaron D; Bellinger, Andrew; McFaline-Figueroa, J Ricardo; Simon, Tracey; Gershanik, Esteban F; Levy, Bruce D; Cohen, David E; Samuels, Martin A; Berry, Gerard T; Frank, Natasha Y

2017-05-01

Acute idiopathic hyperammonemia in an adult patient is a life-threatening condition often resulting in a rapid progression to irreversible cerebral edema and death. While ammonia-scavenging therapies lower blood ammonia levels, in comparison, clearance of waste nitrogen from the brain may be delayed. Therefore, we used magnetic resonance spectroscopy (MRS) to monitor cerebral glutamine levels, the major reservoir of ammonia, in a gastric bypass patient with hyperammonemic coma undergoing therapy with N-carbamoyl glutamate and the ammonia-scavenging agents, sodium phenylacetate and sodium benzoate. Improvement in mental status mirrored brain glutamine levels, as coma persisted for 48h after plasma ammonia normalized. We hypothesize that the slower clearance for brain glutamine levels accounts for the delay in improvement following initiation of treatment in cases of chronic hyperammonemia. We propose MRS to monitor brain glutamine as a noninvasive approach to be utilized for diagnostic and therapeutic monitoring purposes in adult patients presenting with idiopathic hyperammonemia. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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.

Sagittarius Dwarf Galaxy

Science.gov (United States)

Ibata, R.; Murdin, P.

2000-11-01

The Sagittarius DWARF GALAXY is the closest member of the Milky Way's entourage of satellite galaxies. Discovered by chance in 1994, its presence had previously been overlooked because it is largely hidden by the most crowded regions of our own Galaxy with which it is merging....

THE GALAXY OPTICAL LUMINOSITY FUNCTION FROM THE AGN AND GALAXY EVOLUTION SURVEY

Energy Technology Data Exchange (ETDEWEB)

Cool, Richard J. [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Eisenstein, Daniel J. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Kochanek, Christopher S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Brown, Michael J. I. [School of Physics, Monash University, Clayton, Victoria 3800 (Australia); Caldwell, Nelson; Forman, William R.; Hickox, Ryan C.; Jones, Christine; Murray, Stephen S. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Dey, Arjun; Jannuzi, Buell T. [National Optical Astronomy Observatory, Tucson, AZ 85726 (United States); Moustakas, John [Center for Astrophysics and Space Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States)

2012-03-20

We present the galaxy optical luminosity function for the redshift range 0.05 < z < 0.75 from the AGN and Galaxy Evolution Survey, a spectroscopic survey of 7.6 deg{sup 2} in the Booetes field of the NOAO Deep Wide-Field Survey. Our statistical sample is composed of 12,473 galaxies with known redshifts down to I = 20.4 (AB). Our results at low redshift are consistent with those from Sloan Digital Sky Survey; at higher redshift, we find strong evidence for evolution in the luminosity function, including differential evolution between blue and red galaxies. We find that the luminosity density evolves as (1 + z){sup (0.54{+-}0.64)} for red galaxies and (1 + z){sup (1.64{+-}0.39)} for blue galaxies.

Galveston Orientation and Amnesia Test: applicability and relation with the Glasgow Coma Scale Galveston Orientation and Amnesia Test: aplicabilidad y relación con la Escala de Coma de Glasgow Galveston Orientation and Amnesia Test: aplicabilidade e relação com a Escala de Coma de Glasgow

Directory of Open Access Journals (Sweden)

Silvia Cristina Fürbringer e Silva

2007-08-01

Full Text Available Restrictions in the application of the Galveston Orientation and Amnesia Test and questionings about the relationship between conscience and post-traumatic amnesia motivated this study, which aims to identify, through the Glasgow Coma Scale scores, when to initiate the application of this amnesia test, as well to verify the relationship between the results of these two indicators. The longitudinal prospective study was carried at a referral center for trauma care in São Paulo - Brazil. The sample consisted of 73 victims of blunt traumatic brain injury, admitted at this institution between January 03rd and May 03rd 2001. Regarding the applicability, the test could be applied in patients with a Glasgow Coma Scale score > 12; however, the end of post traumatic amnesia was verified in patients who scored > 14 on the scale. A significant relationship (r s = 0.65 was verified between these measures, although different kinds of relationship between the end of the amnesia and changes in consciousness were observed.Restricciones en la aplicación del Galveston Orientation and Amnesia Test y los cuestionamientos sobre la relación entre conciencia y amnesia post-traumática motivaron este estudio que visa identificar, a través de la puntuación de la Escala de Coma de Glasgow, el periodo más adecuado para la aplicación de la prueba de amnesia, y observar la relación entre los resultados de esos dos indicadores. El estudio prospectivo y longitudinal fue realizado en un centro de referencia para traumas en São Paulo - Brasil. El número fue de 73 victimas de trauma craneoencefálico contuso, internadas en esta institución en el periodo de 03/01 a 03/05/2001. Con relación a la aplicabilidad, la prueba puede ser aplicada en los pacientes con la Escala de Coma de Glasgow > 12, pero el término de la amnesia post-traumática fue observado en los pacientes con puntuación > 14 en la escala. Correlación significativa (rs = 0,65 fue observada entre esas

Post-anoxic quantitative MRI changes may predict emergence from coma and functional outcomes at discharge.

Science.gov (United States)

Reynolds, Alexandra S; Guo, Xiaotao; Matthews, Elizabeth; Brodie, Daniel; Rabbani, Leroy E; Roh, David J; Park, Soojin; Claassen, Jan; Elkind, Mitchell S V; Zhao, Binsheng; Agarwal, Sachin

2017-08-01

Traditional predictors of neurological prognosis after cardiac arrest are unreliable after targeted temperature management. Absence of pupillary reflexes remains a reliable predictor of poor outcome. Diffusion-weighted imaging has emerged as a potential predictor of recovery, and here we compare imaging characteristics to pupillary exam. We identified 69 patients who had MRIs within seven days of arrest and used a semi-automated algorithm to perform quantitative volumetric analysis of apparent diffusion coefficient (ADC) sequences at various thresholds. Area under receiver operating characteristic curves (ROC-AUC) were estimated to compare predictive values of quantitative MRI with pupillary exam at days 3, 5 and 7 post-arrest, for persistence of coma and functional outcomes at discharge. Cerebral Performance Category scores of 3-4 were considered poor outcome. Excluding patients where life support was withdrawn, ≥2.8% diffusion restriction of the entire brain at an ADC of ≤650×10 -6 m 2 /s was 100% specific and 68% sensitive for failure to wake up from coma before discharge. The ROC-AUC of ADC changes at ≤450×10 -6 mm 2 /s and ≤650×10 -6 mm 2 /s were significantly superior in predicting failure to wake up from coma compared to bilateral absence of pupillary reflexes. Among survivors, >0.01% of diffusion restriction of the entire brain at an ADC ≤450×10 -6 m 2 /s was 100% specific and 46% sensitive for poor functional outcome at discharge. The ROC curve predicting poor functional outcome at ADC ≤450×10 -6 mm 2 /s had an AUC of 0.737 (0.574-0.899, p=0.04). Post-anoxic diffusion changes using quantitative brain MRI may aid in predicting persistent coma and poor functional outcomes at hospital discharge. Copyright © 2017 Elsevier B.V. All rights reserved.

Acompañamiento pedagógico en la práctica docente en nivel primaria, Comas, 2015

OpenAIRE

Sulca Alarcón, Silvia Marina

2015-01-01

La investigación titulada Acompañamiento pedagógico en la práctica docente en el nivel primaria Comas, 2015 se desarrolló con el objetivo de demostrar que, el acompañamiento pedagógico influye en la práctica docente de las instituciones Educativas correspondientes a la UGEL 04 Comas 2015. El estudio realizado en el contexto en contribuir esfuerzos para la mejora del servicio educativo. La investigación se sustenta en la teoría que sostiene que elacompañamiento pedsgógico es una...

MULTIPLE GALAXY COLLISIONS

Science.gov (United States)

2002-01-01

Here is a sampling of 15 ultraluminous infrared galaxies viewed by NASA's Hubble Space Telescope. Hubble's sharp vision reveals more complexity within these galaxies, which astronomers are interpreting as evidence of a multiple-galaxy pileup. These images, taken by the Wide Field and Planetary Camera 2, are part of a three-year study of 123 galaxies within 3 billion light-years of Earth. The study was conducted in 1996, 1997, and 1999. False colors were assigned to these photos to enhance fine details within these coalescing galaxies. Credits: NASA, Kirk Borne (Raytheon and NASA Goddard Space Flight Center, Greenbelt, Md.), Luis Colina (Instituto de Fisica de Cantabria, Spain), and Howard Bushouse and Ray Lucas (Space Telescope Science Institute, Baltimore, Md.)

Food deprivation and prior anoxic coma have opposite effects on the activity of a visual interneuron in the locust.

Science.gov (United States)

Cross, Kevin P; Britton, Samantha; Mangulins, Rebecca; Money, Tomas G A; Robertson, R Meldrum

2017-04-01

We compared how different metabolic stressors, anoxic coma and food deprivation, affected signaling in neural tissue. We used the locust's Descending Contralateral Movement Detector (DCMD) interneuron because its large axon, high firing frequencies, and rapid conduction velocity make it energetically expensive. We exposed locusts to a 30min anoxic coma or 1day of food deprivation and found contrasting effects on signaling within the axon. After a prior anoxic coma, the DCMD fired fewer high-frequency (>200Hz) action potentials (APs) (Control: 12.4±1.6; Coma: 6.3±0.9) with a reduction in axonal conduction velocity (CV) at all frequencies (∼4-8%) when presented with a standard looming visual stimulus. Prior anoxic coma was also associated with a loss of supernormal conduction by reducing both the number of supernormal APs and the firing frequency with the highest CV. Initially, food deprivation caused a significant increase in the number of low- and high-frequency APs with no differences observed in CV. After controlling for isolation, food deprivation resulted in an increase in high-frequency APs (>200Hz: Control: 17.1±1.7; Food-deprived: 19.9±1.3) and an increase in relative conduction velocity for frequencies >150Hz (∼2%). Action potentials of food-deprived animals had a smaller half-width (Control: 0.45±0.02ms; Food-deprived: 0.40±0.01ms) and decay time (Control: 0.62±0.03ms; Food-deprived: 0.54±0.02ms). Our data indicate that the effects of metabolic stress on neural signaling can be stressor-dependent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Elevated transaminases as a predictor of coma in a patient with anorexia nervosa: a case report and review of the literature

Directory of Open Access Journals (Sweden)

Yoshida Shuhei

2010-09-01

Full Text Available Abstract Introduction Liver injury is a frequent complication associated with anorexia nervosa, and steatosis of the liver is thought to be the major underlying pathology. However, acute hepatic failure with transaminase levels over 1000 IU/mL and deep coma are very rare complications and the mechanism of pathogenesis is largely unknown. Case presentation A 37-year-old Japanese woman showed features of acute liver failure and hepatic coma which were not associated with hypoglycemia or hyper-ammonemia. Our patient's consciousness was significantly improved with the recovery of liver function and normalization of transaminase levels after administration of nutritional support. Conclusions Our case report demonstrates that transaminase levels had an inverse relationship with the consciousness of our patient, although the pathogenesis of coma remains largely unknown. This indicates that transaminase levels can be one of the key predictors of impending coma in patients with anorexia nervosa. Therefore, frequent monitoring of transaminase levels combined with rigorous treatment of the underlying nutritional deficiency and psychiatric disorder are necessary to prevent this severe complication.

A Comparative Study of Glasgow Coma Scale and Full Outline of Unresponsiveness Scores for Predicting Long-Term Outcome After Brain Injury.

Science.gov (United States)

McNett, Molly M; Amato, Shelly; Philippbar, Sue Ann

2016-01-01

The aim of this study was to compare predictive ability of hospital Glasgow Coma Scale (GCS) scores and scores obtained using a novel coma scoring tool (the Full Outline of Unresponsiveness [FOUR] scale) on long-term outcomes among patients with traumatic brain injury. Preliminary research of the FOUR scale suggests that it is comparable with GCS for predicting mortality and functional outcome at hospital discharge. No research has investigated relationships between coma scores and outcome 12 months postinjury. This is a prospective cohort study. Data were gathered on adult patients with traumatic brain injury admitted to urban level I trauma center. GCS and FOUR scores were assigned at 24 and 72 hours and at hospital discharge. Glasgow Outcome Scale scores were assigned at 6 and 12 months. The sample size was n = 107. Mean age was 53.5 (SD = ±21, range = 18-91) years. Spearman correlations were comparable and strongest among discharge GCS and FOUR scores and 12-month outcome (r = .73, p coma scores performed best for both tools, with GCS discharge scores predictive in multivariate models.

The dwarf galaxy population of nearby galaxy clusters

NARCIS (Netherlands)

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

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

Subaru weak-lensing survey of dark matter subhalos in the Coma cluster: Subhalo mass function and statistical properties

International Nuclear Information System (INIS)

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

2014-01-01

We present a 4 deg 2 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 −0.32 +0.42 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.

Distant Galaxy Clusters Hosting Extreme Central Galaxies

Science.gov (United States)

McDonald, Michael

2014-09-01

The recently-discovered Phoenix cluster harbors the most star-forming central cluster galaxy of any cluster in the known Universe, by nearly a factor of 10. This extreme system appears to be fulfilling early cooling flow predictions, although the lack of similar systems makes any interpretation difficult. In an attempt to find other "Phoenix-like" clusters, we have cross-correlated archival all-sky surveys (in which Phoenix was detected) and isolated 4 similarly-extreme systems which are also coincident in position and redshift with an overdensity of red galaxies. We propose here to obtain Chandra observations of these extreme, Phoenix-like systems, in order to confirm them as relaxed, rapidly-cooling galaxy clusters.

[Arreflexic coma and MELAS syndrome].

Science.gov (United States)

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.

A diagnostic scoring system for myxedema coma.

Science.gov (United States)

Popoveniuc, Geanina; Chandra, Tanu; Sud, Anchal; Sharma, Meeta; Blackman, Marc R; Burman, Kenneth D; Mete, Mihriye; Desale, Sameer; Wartofsky, Leonard

2014-08-01

To develop diagnostic criteria for myxedema coma (MC), a decompensated state of extreme hypothyroidism with a high mortality rate if untreated, in order to facilitate its early recognition and treatment. The frequencies of characteristics associated with MC were assessed retrospectively in patients from our institutions in order to derive a semiquantitative diagnostic point scale that was further applied on selected patients whose data were retrieved from the literature. Logistic regression analysis was used to test the predictive power of the score. Receiver operating characteristic (ROC) curve analysis was performed to test the discriminative power of the score. Of the 21 patients examined, 7 were reclassified as not having MC (non-MC), and they were used as controls. The scoring system included a composite of alterations of thermoregulatory, central nervous, cardiovascular, gastrointestinal, and metabolic systems, and presence or absence of a precipitating event. All 14 of our MC patients had a score of ≥60, whereas 6 of 7 non-MC patients had scores of 25 to 50. A total of 16 of 22 MC patients whose data were retrieved from the literature had a score ≥60, and 6 of 22 of these patients scored between 45 and 55. The odds ratio per each score unit increase as a continuum was 1.09 (95% confidence interval [CI], 1.01 to 1.16; P = .019); a score of 60 identified coma, with an odds ratio of 1.22. The area under the ROC curve was 0.88 (95% CI, 0.65 to 1.00), and the score of 60 had 100% sensitivity and 85.71% specificity. A score ≥60 in the proposed scoring system is potentially diagnostic for MC, whereas scores between 45 and 59 could classify patients at risk for MC.

S0 galaxies in Formax

DEFF Research Database (Denmark)

Bedregal...[], A. G.; Aragón-Salamanca, A.; Merrifield, M. R.

2006-01-01

Galaxies: elliptical and lenticular, cD: galaxies: kinematics and dynamics Udgivelsesdato: Oct.1......Galaxies: elliptical and lenticular, cD: galaxies: kinematics and dynamics Udgivelsesdato: Oct.1...

The H IX galaxy survey - II. H I kinematics of H I eXtreme galaxies

Science.gov (United States)

Lutz, K. A.; Kilborn, V. A.; Koribalski, B. S.; Catinella, B.; Józsa, G. I. G.; Wong, O. I.; Stevens, A. R. H.; Obreschkow, D.; Dénes, H.

2018-05-01

By analysing a sample of galaxies selected from the H I Parkes All Sky Survey (HIPASS) to contain more than 2.5 times their expected H I content based on their optical properties, we investigate what drives these H I eXtreme (H IX) galaxies to be so H I-rich. We model the H I kinematics with the Tilted Ring Fitting Code TiRiFiC and compare the observed H IX galaxies to a control sample of galaxies from HIPASS as well as simulated galaxies built with the semi-analytic model DARK SAGE. We find that (1) H I discs in H IX galaxies are more likely to be warped and more likely to host H I arms and tails than in the control galaxies, (2) the average H I and average stellar column density of H IX galaxies is comparable to the control sample, (3) H IX galaxies have higher H I and baryonic specific angular momenta than control galaxies, (4) most H IX galaxies live in higher spin haloes than most control galaxies. These results suggest that H IX galaxies are H I-rich because they can support more H I against gravitational instability due to their high specific angular momentum. The majority of the H IX galaxies inherits their high specific angular momentum from their halo. The H I content of H IX galaxies might be further increased by gas-rich minor mergers. This paper is based on data obtained with the Australia Telescope Compact Array through the large program C 2705.

Cosmic rings from colliding galaxies

Energy Technology Data Exchange (ETDEWEB)

Mitton, S

1976-11-18

Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.

Nurses assessing pain with the Nociception Coma Scale: interrater reliability and validity

NARCIS (Netherlands)

Vink, Peter; Eskes, Anne Maria; Lindeboom, Robert; van den Munckhof, Pepijn; Vermeulen, Hester

2014-01-01

The Nociception Coma Scale (NCS) is a pain observation tool, developed for patients with disorders of consciousness (DOC) due to acquired brain injury (ABI). The aim of this study was to assess the interrater reliability of the NCS and NCS-R among nurses for the assessment of pain in ABI patients

Stellar feedback in galaxies and the origin of galaxy-scale winds

Science.gov (United States)

Hopkins, Philip F.; Quataert, Eliot; Murray, Norman

2012-04-01

Feedback from massive stars is believed to play a critical role in driving galactic super-winds that enrich the intergalactic medium and shape the galaxy mass function, mass-metallicity relation and other global galaxy properties. In previous papers, we have introduced new numerical methods for implementing stellar feedback on sub-giant molecular cloud (sub-GMC) through galactic scales in numerical simulations of galaxies; the key physical processes include radiation pressure in the ultraviolet through infrared, supernovae (Type I and Type II), stellar winds ('fast' O star through 'slow' asymptotic giant branch winds), and H II photoionization. Here, we show that these feedback mechanisms drive galactic winds with outflow rates as high as ˜10-20 times the galaxy star formation rate. The mass-loading efficiency (wind mass-loss rate divided by the star formation rate) scales roughly as ? (where Vc is the galaxy circular velocity), consistent with simple momentum-conservation expectations. We use our suite of simulations to study the relative contribution of each feedback mechanism to the generation of galactic winds in a range of galaxy models, from Small Magellanic Cloud like dwarfs and Milky Way (MW) analogues to z˜ 2 clumpy discs. In massive, gas-rich systems (local starbursts and high-z galaxies), radiation pressure dominates the wind generation. By contrast, for MW-like spirals and dwarf galaxies the gas densities are much lower and sources of shock-heated gas such as supernovae and stellar winds dominate the production of large-scale outflows. In all of our models, however, the winds have a complex multiphase structure that depends on the interaction between multiple feedback mechanisms operating on different spatial scales and time-scales: any single feedback mechanism fails to reproduce the winds observed. We use our simulations to provide fitting functions to the wind mass loading and velocities as a function of galaxy properties, for use in cosmological

Clustering of Star-forming Galaxies Near a Radio Galaxy at z=5.2

Science.gov (United States)

Overzier, Roderik A.; Miley, G. K.; Bouwens, R. J.; Cross, N. J. G.; Zirm, A. W.; Benítez, N.; Blakeslee, J. P.; Clampin, M.; Demarco, R.; Ford, H. C.; Hartig, G. F.; Illingworth, G. D.; Martel, A. R.; Röttgering, H. J. A.; Venemans, B.; Ardila, D. R.; Bartko, F.; Bradley, L. D.; Broadhurst, T. J.; Coe, D.; Feldman, P. D.; Franx, M.; Golimowski, D. A.; Goto, T.; Gronwall, C.; Holden, B.; Homeier, N.; Infante, L.; Kimble, R. A.; Krist, J. E.; Mei, S.; Menanteau, F.; Meurer, G. R.; Motta, V.; Postman, M.; Rosati, P.; Sirianni, M.; Sparks, W. B.; Tran, H. D.; Tsvetanov, Z. I.; White, R. L.; Zheng, W.

2006-01-01

We present HST ACS observations of the most distant radio galaxy known, TN J0924-2201 at z=5.2. This radio galaxy has six spectroscopically confirmed Lyα-emitting companion galaxies and appears to lie within an overdense region. The radio galaxy is marginally resolved in i775 and z850, showing continuum emission aligned with the radio axis, similar to what is observed for lower redshift radio galaxies. Both the half-light radius and the UV star formation rate are comparable to the typical values found for Lyman break galaxies at z~4-5. The Lyα emitters are sub-L* galaxies, with deduced star formation rates of 1-10 Msolar yr-1. One of the Lyα emitters is only detected in Lyα. Based on the star formation rate of ~3 Msolar yr-1 calculated from Lyα, the lack of continuum emission could be explained if the galaxy is younger than ~2 Myr and is producing its first stars. Observations in V606i775z850 were used to identify additional Lyman break galaxies associated with this structure. In addition to the radio galaxy, there are 22 V606 break (z~5) galaxies with z850dropouts extracted from GOODS and the UDF parallel fields. We find evidence for an overdensity to very high confidence (>99%), based on a counts-in-cells analysis applied to the control field. The excess suggests that the V606 break objects are associated with a forming cluster around the radio galaxy. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 9291.

Transient Coma Due To Epidural Anesthesia: The Role of Loss of Sensory Input.

LENUS (Irish Health Repository)