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Sample records for hellyer volcanogenic massive

  1. Geology of volcanogenic massive sulfide deposit near Meli ...

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. Results of a preliminary study conducted on the volcanogenic massive sulfide (VMS) deposit near Meli/Rahwa, northern Ethiopia are presented in the paper. The study area forms part of. Neoproterozoic basement of northern Ethiopia and southern part of the Arabian Nubian Shield. (ANS). Selected surface rock ...

  2. Volcanogenic massive sulfide occurrence model: Chapter C in Mineral deposit models for resource assessment

    Science.gov (United States)

    Shanks, W.C. Pat; Koski, Randolph A.; Mosier, Dan L.; Schulz, Klaus J.; Morgan, Lisa A.; Slack, John F.; Ridley, W. Ian; Dusel-Bacon, Cynthia; Seal, Robert R.; Piatak, Nadine M.; Shanks, W.C. Pat; Thurston, Roland

    2012-01-01

    Volcanogenic massive sulfide deposits, also known as volcanic-hosted massive sulfide, volcanic-associated massive sulfide, or seafloor massive sulfide deposits, are important sources of copper, zinc, lead, gold, and silver (Cu, Zn, Pb, Au, and Ag). These deposits form at or near the seafloor where circulating hydrothermal fluids driven by magmatic heat are quenched through mixing with bottom waters or porewaters in near-seafloor lithologies. Massive sulfide lenses vary widely in shape and size and may be podlike or sheetlike. They are generally stratiform and may occur as multiple lenses.

  3. Challenges for rescuing drill core from volcanogenic massive sulfide deposits in northern Wisconsin

    Science.gov (United States)

    Stanley, V.; Schoephoester, P.; Lodge, R. W. D.

    2016-12-01

    Providing adequate physical care for unique lithologies can be a challenge for rock core repositories. The purpose of a repository is to preserve its collections such that they will be available and useful for current and future research. Preservation requires both documentation and physical care, including the state of the facility housing the collections, as specimens can be endangered by environmental factors. Digital documentation is a crucial first step in rescuing at-risk samples as it allows the collection to be monitored through time. Exploratory drill core from the Flambeau copper-gold mine in Ladysmith, WI was donated to the Wisconsin Geological and Natural History Survey (WGNHS). The collection includes over 4.7 km of irreplaceable core from 50 sites. The ore body is situated in the Ladysmith-Rhinelander Volcanic Complex, an Early Proterozoic greenstone belt that hosts at least 13 volcanogenic massive sulfide deposits (DeMatties, 1996), including Flambeau. Mineral assemblages include up to 50% sulfide minerals, mainly pyrite and marcasite (May and Dinkowitz, 1996). These lithologies present a unique preservation challenge - storage conditions must be temperature and humidity controlled to prevent pyrite oxidation (Newman 1998), which chemically and physically degrades the samples as well as labels, containers, and shelving. Once initiated, pyrite oxidation cannot be stopped or reversed, but may be stabilized (Howie, 1992). Although protecting these materials is a vital part of the WGNHS mission, climate-control modifications to the facility are cost-prohibitive. In order to rescue the samples, we documented the collection's present state. We developed and implemented a new database schema including IGSNs to improve metadata records, track samples, and link data. Although preservation of the physical samples remains a challenge, digital workflows and data management improvements will allow WGNHS to monitor the condition of these samples while also

  4. The Sanfengshan copper deposit and early Carboniferous volcanogenic massive sulfide mineralization in the Beishan orogenic belt, Northwestern China

    Science.gov (United States)

    Wang, Jialin; Gu, Xuexiang; Zhang, Yongmei; Zhou, Chao; He, Ge; Liu, Ruiping

    2018-03-01

    The Sanfengshan copper deposit, located in the Beishan orogenic belt, Northwestern China, is hosted in the lower member of the Hongliuyuan Formation, an early Carboniferous metavolcanic-sedimentary sequence. Mineralization occurs as stratiform, stratiform-like and lenticular orebodies, and comprises of laminated, brecciated, banded, massive, and disseminated ores. The mineralogy is dominated by pyrite, chalcopyrite and sphalerite. Fe-Mn chert is widely distributed and generally occurs as massive, laminated, bands or lenses, which are consistent with the orebody. Alteration at Sanfengshan displays a clear concentric zoning pattern and the footwall alteration is more intense and somewhat thicker than the hanging-wall alteration. Systematic geochemical investigation on the volcanic rocks in this area shows that the basalts of the Hongliuyuan Formation (HLY) are predominantly tholeiites with nearly flat rare earth element (REE) pattern, insignificant negative anomalies of high field strength elements (HFSEs), and low Ti/V and Th/Nb ratios. They were most likely derived from partial melting of depleted asthenospheric mantle and formed in a fore-arc setting during initiation of the southward subduction of the Paleo-Asian Ocean. The basalts of the Maotoushan Formation (MTS) display a calc-alkaline nature and are enriched in large ion lithophile elements (LILEs) and depleted in HFSEs, suggesting an active continental margin setting. Sulfur isotope (δ34S) values of the sulfide and sulfate minerals vary between 0‰ and 5.4‰, which are consistent with sulfur derivation from leaching of the host volcanic rocks, although a direct magmatic contribution cannot be ruled out. The Re-Os isotope data of pyrite yield an isochron age of 353 ± 35 Ma, consistent with the age of the host HLY basalts. Thus, a syngenetic (volcanogenic massive sulfide) model is proposed and it is concluded that the Sanfengshan copper deposit is a typical Cyprus-type VMS deposit that formed in an early

  5. Correlation between compositions of ore and host rocks in volcanogenic massive sulfide deposits of the Southern Urals

    Science.gov (United States)

    Seravkin, I. B.

    2013-05-01

    The geology and typification of volcanogenic massive sulfide (VMS) deposits of the Southern Urals are considered. The mineralogical-geochemical types of these deposits correlate with the composition of the underlying igneous rocks: Ni-Co-Cu deposits correlatedwith serpentinites (Ivanovka type); (Co)-Cu deposits, with basalts (Dombarovka type); Cu-Zn deposits, with basalt-rhyolite and basalt-andesite-rhyolite complexes (Ural type); and Au-Ba-Pb-Zn-Cu deposits, with basalt-andesite-rhyolite complexes with predominance of andesitic and felsic volcanics (Baimak type). The Ural-type deposits are subdivided into three subtypes: I, underlain by basalts (Zn-Cu deposits); II, hosted in felsic volcanic rocks of bimodal complexes (Cu-Zn deposits); and III, hosted in felsic volcanic rocks of continuously differentiated complexes (Zn-Cu deposits with Ba, Pb, and As). The above types and subtypes bearing local names are compared with global types of VMS deposits (MAR, Cyprus, Noranda, and Kuroko), to which they are close but not identical.

  6. Multiple sulphur and lead sources recorded in hydrothermal exhalites associated with the Lemarchant volcanogenic massive sulphide deposit, central Newfoundland, Canada

    Science.gov (United States)

    Lode, Stefanie; Piercey, Stephen J.; Layne, Graham D.; Piercey, Glenn; Cloutier, Jonathan

    2017-01-01

    Metalliferous sedimentary rocks (mudstones, exhalites) associated with the Cambrian precious metal-bearing Lemarchant Zn-Pb-Cu-Au-Ag-Ba volcanogenic massive sulphide (VMS) deposit, Tally Pond volcanic belt, precipitated both before and after VMS mineralization. Sulphur and Pb isotopic studies of sulphides within the Lemarchant exhalites provide insight into the sources of S and Pb in the exhalites as a function of paragenesis and evolution of the deposit and subsequent post-depositional modification. In situ S isotope microanalyses of polymetallic sulphides (euhedral and framboidal pyrite, anhedral chalcopyrite, pyrrhotite, galena and euhedral arsenopyrite) by secondary ion mass spectrometry (SIMS) yielded δ34S values ranging from -38.8 to +14.4 ‰, with an average of ˜ -12.8 ‰. The δ34S systematics indicate sulphur was predominantly biogenically derived via microbial/biogenic sulphate reduction of seawater sulphate, microbial sulphide oxidation and microbial disproportionation of intermediate S compounds. These biogenic processes are coupled and occur within layers of microbial mats consisting of different bacterial/archaeal species, i.e., sulphate reducers, sulphide oxidizers and those that disproportionate sulphur compounds. Inorganic processes or sources (i.e., thermochemical sulphate reduction of seawater sulphate, leached or direct igneous sulphur) also contributed to the S budget in the hydrothermal exhalites and are more pronounced in exhalites that are immediately associated with massive sulphides. Galena Pb isotopic compositions by SIMS microanalysis suggest derivation of Pb from underlying crustal basement (felsic volcanic rocks of Sandy Brook Group), whereas less radiogenic Pb derived from juvenile sources leached from mafic volcanic rocks of the Sandy Brook Group and/or Tally Pond group. This requires that the hydrothermal fluids interacted with juvenile and evolved crust during hydrothermal circulation, which is consistent with the existing

  7. Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Foley, Nora K.; Slack, John E.; Koenig, Alan E.; Oscarson, Robert L.

    2012-01-01

    Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high field strength element (HFSE)- and rare-earth element (REE)-rich peralkaline (pantelleritic) metarhyolite, and interlayered pyritic argillite and mudstone of the Mystic Creek Member of the Totatlanika Schist Formation. Mystic Creek metarhyolite and alkali basalt (Chute Creek Member) constitute a bimodal pair that formed in an extensional environment. A synvolcanic peralkaline quartz porphyry containing veins of fluorite, sphalerite, pyrite, and quartz intrudes the central footwall at Dry Creek. The Anderson Mountain deposit, located ~32 km to the southwest, occurs within calc-alkaline felsic to intermediate-composition metavolcanic rocks and associated graphitic argillite of the Wood River assemblage. Felsic metavolcanic rocks there have only slightly elevated HFSEs and REEs. The association of abundant graphitic and siliceous argillite with the felsic volcanic rocks together with low Cu contents in the Bonnifield deposits suggests classification as a siliciclastic-felsic type of VMS deposit. Bonnifield massive sulfides and host rocks were metamorphosed and deformed under greenschist-facies conditions in the Mesozoic. Primary depositional textures, generally uncommon, consist of framboids, framboidal aggregates, and spongy masses of pyrite. Sphalerite, the predominant base metal sulfide, encloses early pyrite framboids. Galena and chalcopyrite accompanied early pyrite formation but primarily formed late in the paragenetic sequence. Silver-rich tetrahedrite is a minor late phase at the Dry Creek deposit. Gold and Ag are present in low to moderate amounts in pyrite from all of

  8. Geochemical and Sulfur-Isotopic Signatures of Volcanogenic Massive Sulfide Deposits on Prince of Wales Island and Vicinity, Southeastern Alaska

    Science.gov (United States)

    Slack, John F.; Shanks, Wayne C.; Karl, Susan M.; Gemery, Pamela A.; Bittenbender, Peter E.; Ridley, W. Ian

    2007-01-01

    Stratabound volcanogenic massive sulfide (VMS) deposits on Prince of Wales Island and vicinity, southeastern Alaska, occur in two volcanosedimentary sequences of Late Proterozoic through Cambrian and of Ordovician through Early Silurian age. This study presents geochemical data on sulfide-rich samples, in situ laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of sulfide minerals, and sulfur-isotopic analyses of sulfides and sulfates (barite) for identifying and distinguishing between primary sea-floor signatures and later regional metamorphic overprints. These datasets are also used here in an attempt to discriminate the VMS deposits in the older Wales Group from those in the younger Moira Sound unit (new informal name). The Wales Group and its contained VMS deposits have been multiply deformed and metamorphosed from greenschist to amphibolite grade, whereas the Moira Sound unit and related VMS deposits are less deformed and generally less metamorphosed (lower to middle greenschist grade). Variations in the sulfide mineral assemblages and textures of the VMS deposits in both sequences reflect a combination of processes, including primary sea-floor mineralization and sub-sea-floor zone refining, followed by metamorphic recrystallization. Very coarse grained (>1 cm diam) sulfide minerals and abundant pyrrhotite are restricted to VMS deposits in a small area of the Wales Group, at Khayyam and Stumble-On, which record high-grade metamorphism of the sulfides. Geochemical and sulfur-isotopic data distinguish the VMS deposits in the Wales Group from those in the Moira Sound unit. Although base- and precious-metal contents vary widely in sulfide-rich samples from both sequences, samples from the Moira Sound generally have proportionately higher Ag contents relative to base metals and Au. In situ LA-ICP-MS analysis of trace elements in the sulfide minerals suggests that primary sea-floor hydrothermal signatures are preserved in some samples (for

  9. Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Slack, John F.; Koenig, Alan E.; Foley, Nora K.; Oscarson, Robert L.; Gans, Kathleen D.

    2011-01-01

    This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of sulfide minerals determined by electron microprobe and laser ablation—inductively coupled plasma—mass spectrometry (LA-ICP-MS) techniques. The PDF consists of text, appendix explaining the analytical methods used for the analyses presented in the data tables, a sample location map, and seven data tables. The seven tables are also available as spreadsheets in several file formats. Descriptions and discussions of the Bonnifield deposits are given in Dusel-Bacon and others (2004, 2005, 2006, 2007, 2010).

  10. Cu-Ag Besshi type volcanogenic massive sulfide mineralization in the Late Cretaceous volcano- sedimentary sequence: the case of Garmabe Paein deposit, southeast of Shahrood

    Directory of Open Access Journals (Sweden)

    Majid Tashi

    2017-07-01

    Full Text Available Introduction Iran hosts numerous types of Volcanogenic massive sulfide (VMS deposits that occur within different tectonic assemblages and have formed at discrete time periods (Mousivand et al. 2008. The Sabzevar zone hosts several VMS deposits including the Nudeh Cu-Ag deposit (Maghfouri, 2012 and some deposits in the Kharturan area (Tashi et al., 2014, and the Kharturan area locates in the Sabzevar subzone of the Central East Iranian Microcontinent. The Sabzevar subzone mainly involves Mesozoic and Cenozoic rock unites. The Late Cretaceous ophiolite mellanges and volcano-sedimentary sequences have high extension in the Subzone. Based on Rossetti (Rossetti et al. 2010, the Cretaceous rock units were formed in a back-arc setting due to subduction of the Neo-Tethyan oceanic crust beneath the Iranian plate. The exposed rock units of the Kharturan area from bottom to top are dominated by Early Cretaceous, orbitolina-bearing massive limestone, dacitic-andesitic volcanics and related volcaniclastic rocks٫ chert and radiolarite and Late Cretaceous globotrunkana- bearing limestone, paleocene polygenic conglomerate consisting of the Cretaceous volcanics and limestone pebbles (equal to the Kerman conglomerate, and Pliocene weakly-cemented polygenic conglomerate horizon. The Garmabe Paein copper-silver deposit and the Asbkeshan deposit and a few occurrences, are located at 290 km southeast of Shahrood and they have occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone. The aim of this study is to discuss the genesis of the Garmabe Paein deposit based on geological, textural and structural, mineralogical and geochemical evidence. Materials and methods A field study and sampling was performed during the year 2013. During the field observations, 94 rock samples were collected from the study area, and 45 thin sections were prepared and studied using a polarizing microscope. Also, 5 samples for the XRD method, 21 samples for

  11. Geology, ore facies and sulfur isotopes geochemistry of the Nudeh Besshi-type volcanogenic massive sulfide deposit, southwest Sabzevar basin, Iran

    Science.gov (United States)

    Maghfouri, Sajjad; Rastad, Ebrahim; Mousivand, Fardin; Lin, Ye; Zaw, Khin

    2016-08-01

    The southwest Sabzevar basin is placed in the southwestern part of a crustal domain known as the Sabzevar zone, at the north of Central Iranian microcontinent. This basin hosts abundant mineral deposits; particularly of the Mn exhalative and Cu-Zn volcanogenic massive sulfide (VMS) types. The evolution of this basin is governed by the Neo-tethys oceanic crust subduction beneath the Central Iranian microcontinent and by the resulting continental arc (Sanandaj-Sirjan) and back-arc (Sabzevar-Naien). This evolution followed two major sequences: (I) Lower Late Cretaceous Volcano-Sedimentary Sequence (LLCVSS), which is indicated by fine-grained siliciclastic sediments, gray basic coarse-grained different pyroclastic rocks and bimodal volcanism. During this stage, tuff-hosted stratiform, exhalative Mn deposits (Nudeh, Benesbourd, Ferizy and Goft), oxide Cu deposits (Garab and Ferizy) and Cu-Zn VMS (Nudeh, Chun and Lala) deposits formed. (II) Upper Late Cretaceous Sedimentary Dominated Sequence (ULCSS), including pelagic limestone, marly tuff, silty limestone and marl with minor andesitic tuff rocks. The economically most important Mn (Zakeri and Cheshmeh-sefid) deposits of Sabzevar zone occur within the marly tuff of this sequence. The Nudeh Cu-Zn volcanogenic massive sulfide (VMS) deposit is situated in the LLCVSS. The host-rock of deposits consists of alkali olivine basalt flow and tuffaceous silty sandstone. Mineralization occurs as stratiform blanket-like and tabular orebodies. Based on ore body structure, mineralogy, and ore fabric, we recognize three different ore facies in the Nudeh deposit: (1) a stringer zone, consisting of a discordant mineralization of sulfides forming a stockwork of sulfide-bearing quartz veins cutting the footwall volcano-sedimentary rocks; (2) a massive ore, consisting of massive replacement pyrite, chalcopyrite, sphalerite and Friedrichite with magnetite; (3) bedded ore, with laminated to disseminated pyrite, and chalcopyrite

  12. Silver and silver-bearing minerals at the Um Samiuki volcanogenic massive sulphide deposit, Eastern Desert, Egypt

    Science.gov (United States)

    Shalaby, Ibrahim M.; Stumpfl, Eugen; Helmy, Hassan M.; El Mahallawi, Mahmoud M.; Kamel, Omar A.

    2004-10-01

    The Um Samiuki Zn Cu Pb Ag mineralisation, south Eastern Desert, Egypt is hosted by felsic volcanic rocks which form part of the 712-Ma-old, east-west-trending Shadli Volcanic Belt. Two major occurrences of massive sulphides are present at the top of rhyolitic breccia in the Western and Eastern mine areas. In each occurrence, a bornite-bearing zone is overlain by a pyrite-chalcopyrite-bearing zone and underlain by a disseminated, Cu-depleted zone. In the massive sulphide ore, sphalerite, chalcopyrite, pyrite, galena, bornite and tetrahedrite tennantite are major minerals, whereas arsenopyrite, pyrrhotite, molybdenite and magnetite are accessory phases. Covellite and digenite are common secondary minerals. Bornite, tetrahedrite tennantite and covellite contain high amounts of silver (averages of 1.97, 1.39 and 1.82 wt% respectively). Based on mineralogical balance calculations, bornite and covellite accommodate 80% of silver in the Um Samiuki deposit. Ag was incorporated in the crystal structure of the early-crystallised copper sulphides and sulphosalts and silver minerals. The temperature, sequential precipitation of the fluids and the structure of the crystallising phases control the distribution of silver. Post-depositional deformation and metamorphic processes caused liberation, remobilisation and redeposition of silver within the massive sulphides.

  13. Relationships between microbial communities and environmental parameters at sites impacted by mining of volcanogenic massive sulfide deposits, Prince William Sound, Alaska

    Science.gov (United States)

    Foster, A.L.; Munk, L.; Koski, R.A.; Shanks, Wayne C.; Stillings, L.L.

    2008-01-01

    The relations among geochemical parameters and sediment microbial communities were examined at three shoreline sites in the Prince William Sound, Alaska, which display varying degrees of impact by acid-rock drainage (ARD) associated with historic mining of volcanogenic massive sulfide deposits. Microbial communities were examined using total fatty acid methyl esters (FAMEs), a class of compounds derived from lipids produced by eukaryotes and prokaryotes (bacteria and Archaea); standard extraction techniques detect FAMEs from both living (viable) and dead (non-viable) biomass, but do not detect Archaeal FAMEs. Biomass and diversity (as estimated by FAMEs) varied strongly as a function of position in the tidal zone, not by study site; subtidal muds, Fe oxyhydroxide undergoing biogenic reductive dissolution, and peat-rich intertidal sediment had the highest values. These estimates were lowest in acid-generating, intertidal zone sediment; if valid, the estimates suggest that only one or two bacterial species predominate in these communities, and/or that Archeal species are important members of the microbial community in this sediment. All samples were dominated by bacterial FAMEs (median value >90%). Samples with the highest absolute abundance of eukaryotic FAMEs were biogenic Fe oxyhydroxides from shallow freshwater pools (fungi) and subtidal muds (diatoms). Eukaryotic FAMEs were practically absent from low-pH, sulfide-rich intertidal zone sediments. The relative abundance of general microbial functional groups such as aerobes/anaerobes and gram(+)/gram(-) was not estimated due to severe inconsistency among the results obtained using several metrics reported in the literature. Principal component analyses (PCAs) were performed to investigate the relationship among samples as separate functions of water, sediment, and FAMEs data. PCAs based on water chemistry and FAMEs data resulted in similar relations among samples, whereas the PCA based on sediment chemistry

  14. Geology, lithogeochemistry and paleotectonic setting of the host sequence to the Kangasjärvi Zn-Cu deposit, central Finland: implications for volcanogenic massive sulphide exploration in the Vihanti-Pyhäsalmi district

    Directory of Open Access Journals (Sweden)

    Michael D. Roberts

    2004-01-01

    Full Text Available The Kangasjärvi Zn-Cu deposit is a highly deformed and metamorphosed Paleoproterozoic volcanogenic massive sulphide (VMS deposit located in the Vihanti-Pyhäsalmi base metal mining district of central Finland. The host sequence to the deposit, referred to as the Inner Volcanic Sequence (IVS, is comprised of a bimodal suite of metavolcanic rocks and a regionally extensive tonalite-trondhjemite gneiss (sub-volcanic intrusions?. A separate and perhaps younger sequence of mafic volcanic rocks, with irregular intervals of undifferentiated intermediate to felsic schists and metalimestones, referred to as the Outer Volcanic Sequence (OVS, are separated from the IVS sequence by intervals of metagreywacke and U-P-bearing graphitic schists. A stratigraphic scheme for rocks within the IVS is proposed based on outcrop observations, locally preserved volcanic textures, aspects of seafloor-related hydrothermal alteration and lithogeochemistry. In this scheme, rare andesites form the lowermostvolcanic stratigraphy and are overlain by typical island-arc basalts that were erupted in a subaqueous setting. Tonalite-trondhjemite subvolcanic intrusions were locally emplaced within andesites and coeval rhyolites were extruded on the basaltic substrate. The extrusion of rhyolites, including high-silica rhyolites, was coeval with regional-scale, pre-metamorphic seafloor hydrothermal alteration and local sulphide mineralization. Extensively altered rhyolites envelope massive sulphides and are underlain by altered basalts. The latter rocks are now characterized by a variety of low-variance metamorphic mineral assemblages (e.g. orthoamphibole-cordierite rocks and define a domain of intense pre-metamorphic chlorite ± sericite alteration in the stratigraphic footwall of the deposit. The altered nature of these rocks is attributed to reaction with seawater-related hydrothermal fluids within a zone of upflow at or near the seafloor. The fundamental controls on convective

  15. Copper Deposits in Sedimentary and Volcanogenic Rocks

    Science.gov (United States)

    Tourtelot, Elizabeth B.; Vine, James David

    1976-01-01

    Copper deposits occur in sedimentary and volcanogenic rocks within a wide variety of geologic environments where there may be little or no evidence of hydrothermal alteration. Some deposits may be hypogene and have a deep-seated source for the ore fluids, but because of rapid cooling and dilution during syngenetic deposition on the ocean floor, the resulting deposits are not associated with hydrothermal alteration. Many of these deposits are formed at or near major tectonic features on the Earth's crust, including plate boundaries, rift valleys, and island arcs. The resulting ore bodies may be stratabound and either massive or disseminated. Other deposits form in rocks deposited in shallow-marine, deltaic, and nonmarine environments by the movement and reaction of interstratal brines whose metal content is derived from buried sedimentary and volcanic rocks. Some of the world's largest copper deposits were probably formed in this manner. This process we regard as diagenetic, but some would regard it as syngenetic, if the ore metals are derived from disseminated metal in the host-rock sequence, and others would regard the process as epigenetic, if there is demonstrable evidence of ore cutting across bedding. Because the oxidation associated with diagenetic red beds releases copper to ground-water solutions, red rocks and copper deposits are commonly associated. However, the ultimate size, shape, and mineral zoning of a deposit result from local conditions at the site of deposition - a logjam in fluvial channel sandstone may result in an irregular tabular body of limited size; a petroleum-water interface in an oil pool may result in a copper deposit limited by the size and shape of the petroleum reservoir; a persistent thin bed of black shale may result in a copper deposit the size and shape of that single bed. The process of supergene enrichment has been largely overlooked in descriptions of copper deposits in sedimentary rocks. However, supergene processes may be

  16. Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Aleinikoff, John N.; Premo, Wayne R.; Paradis, Suzanne; Lohr-Schmidt, Ilana; Gough, Larry P.; Day, Warren C.

    2007-01-01

    This paper summarizes the results of field and laboratory investigations, including whole-rock geochemistry and radiogenic isotopes, of outcrop and drill core samples from volcanogenic massive sulfide (VMS) deposits and associated metaigneous rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range (see fig. 1 of Editors’ Preface and Overview). U-Pb zircon igneous crystallization ages from felsic rocks indicate a prolonged period of Late Devonian to Early Mississippian (373±3 to 357±4 million years before present, or Ma) magmatism. This magmatism occurred in a basinal setting along the ancient Pacific margin of North America. The siliceous and carbonaceous compositions of metasedimentary rocks, Precambrian model ages based on U-Pb dating of zircon and neodymium ages, and for some units, radiogenic neodymium isotopic compositions and whole-rock trace-element ratios similar to those of continental crust are evidence for this setting. Red Mountain (also known as Dry Creek) and WTF, two of the largest VMS deposits, are hosted in peralkaline metarhyolite of the Mystic Creek Member of the Totatlanika Schist. The Mystic Creek Member is distinctive in having high concentrations of high-field-strength elements (HFSE) and rare-earth elements (REE), indicative of formation in a within-plate (extensional) setting. Mystic Creek metarhyolite is associated with alkalic, within-plate basalt of the Chute Creek Member; neodymium isotopic data indicate an enriched mantle component for both members of this bimodal (rhyolite-basalt) suite. Anderson Mountain, the other significant VMS deposit, is hosted by the Wood River assemblage. Metaigneous rocks in the Wood River assemblage span a wide compositional range, including andesitic rocks, which are characteristic of arc volcanism. Our data suggest that the Mystic Creek Member likely formed in an extensional, back-arc basin that was associated with an outboard continental-margin volcanic arc that included

  17. Geology of volcanogenic massive sulfide deposit near Meli ...

    African Journals Online (AJOL)

    Bheema

    These efforts in Tigray region, northern Ethiopia, also have resulted in .... Neoproterozoic age and intruded by syn- and post-tectonic granitoids and has experienced poly- phase deformations. The rocks belong to Tsaliet Group. ... few cms to 10m exhibit highly fragmented rocks due to deformation and contain higher density.

  18. Geology of volcanogenic massive sulfide deposit near Meli ...

    African Journals Online (AJOL)

    Bheema

    The Precambrian Geology of Ethiopia: A review. Africa Geoscience Review, 8: 271-288. Avigad, D., Stern, R.J., Beyth, M., Miller, N & McWilliams, M.O. 2007. Detrital zircon U-Pb geochronology of Cryogenian diamictites and Lower Paleozoic sandstone in Ethiopia. (Tigray): Age constraints on Neoproterozoic glaciation and ...

  19. Geology of volcanogenic massive sulfide deposit near Meli ...

    African Journals Online (AJOL)

    VMS) deposit near Meli/Rahwa, northern Ethiopia are presented in the paper. The study area forms part of Neoproterozoic basement of northern Ethiopia and southern part of the Arabian Nubian Shield (ANS). Selected surface rock samples of ...

  20. Deposit model for volcanogenic uranium deposits

    Science.gov (United States)

    Breit, George N.; Hall, Susan M.

    2011-01-01

    Volcanism is a major contributor to the formation of important uranium deposits both close to centers of eruption and more distal as a result of deposition of ash with leachable uranium. Hydrothermal fluids that are driven by magmatic heat proximal to some volcanic centers directly form some deposits. These fluids leach uranium from U-bearing silicic volcanic rocks and concentrate it at sites of deposition within veins, stockworks, breccias, volcaniclastic rocks, and lacustrine caldera sediments. The volcanogenic uranium deposit model presented here summarizes attributes of those deposits and follows the focus of the International Atomic Energy Agency caldera-hosted uranium deposit model. Although inferred by some to have a volcanic component to their origin, iron oxide-copper-gold deposits with economically recoverable uranium contents are not considered in this model.

  1. Volcanogenic massive sulfide deposits of the world: Database and grade and tonnage models

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Information on VMS deposits from around the world. It also presents new grade and tonnage models for three subtypes of VMS deposits and a text file allowing...

  2. Regional setting and characteristics of the Neoproterozoic Wadi Hamama Zn-Cu-Ag-Au prospect: evidence for an intra-oceanic island arc-hosted volcanogenic hydrothermal system

    Science.gov (United States)

    Abd El-Rahman, Yasser; Surour, Adel A.; El-Manawi, Abdel Hamid W.; El-Dougdoug, Abdel-Monem A.; Omar, Sayed

    2015-04-01

    The Wadi Hamama area is a volcanogenic Zn-Cu-Au-Ag prospect. It is hosted by a Neoproterozoic bimodal-mafic sequence, which comprises basalt, dacite and rhyolite along with volcaniclastic rocks. The rocks have a low-K tholeiitic affinity and are enriched in large ion lithophile elements over high field strength elements, which indicated their formation in an intra-oceanic island arc tectonic setting. The area was intruded by a tonalite-trondhjemite body, which has an intra-oceanic island arc affinity and later by diorite, which has a cordilleran-margin geochemical affinity. These rock units were intruded by post-tectonic granite dykes, which have a within-plate geochemical signature. There is a quartz-carbonate horizon extending along the contact between the basalt and the volcaniclastic rocks, mainly banded and lapilli tuffs. This horizon is of exhalative origin and is underlain by a mushroom-shaped alteration zone extending from the horizon down to the massive basalt. The footwall alteration is characterized by a silica-rich core surrounded by a thick chlorite sheath. Both the quartz-carbonate horizon and the footwall-altered rocks enclose historical trenches and pits. Sulfide-rich core samples are enriched in Zn, relative to Cu, and in Ag, which indicates the low-temperature nature of the hydrothermal system. The prospect was affected by supergene processes, which led to the widespread occurrence of secondary copper minerals and gold enrichment relative to the leached base metals, especially Zn. The prospect formed through a limited rifting of an intra-oceanic island arc which resulted in the formation of a small-scale volcanogenic Zn-Cu-Ag-Au prospect.

  3. Massive Gravity

    National Research Council Canada - National Science Library

    de Rham, Claudia

    2014-01-01

    We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP...

  4. Massive gravity

    OpenAIRE

    Claudia de Rham

    2016-01-01

    We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...

  5. Massive Branes

    NARCIS (Netherlands)

    Bergshoeff, E. A.; Lozano, Y.; Ortín, Tomas

    1997-01-01

    Published in: Nucl. Phys. B 518 (1998) 363-423 citations recorded in [Science Citation Index] Abstract: We investigate the effective worldvolume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity (``massive branes'') and their M-theoretic

  6. Massive branes

    NARCIS (Netherlands)

    Bergshoeff, E; Lozano, Y; Ortin, T

    1998-01-01

    We investigate the effective world-volume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity ("massive branes") and their M-theoretic origin. In the case of the solitonic 5-brane of type IIA superstring theory the construction of the

  7. Massive Stars

    Science.gov (United States)

    Livio, Mario; Villaver, Eva

    2009-11-01

    Participants; Preface Mario Livio and Eva Villaver; 1. High-mass star formation by gravitational collapse of massive cores M. R. Krumholz; 2. Observations of massive star formation N. A. Patel; 3. Massive star formation in the Galactic center D. F. Figer; 4. An X-ray tour of massive star-forming regions with Chandra L. K. Townsley; 5. Massive stars: feedback effects in the local universe M. S. Oey and C. J. Clarke; 6. The initial mass function in clusters B. G. Elmegreen; 7. Massive stars and star clusters in the Antennae galaxies B. C. Whitmore; 8. On the binarity of Eta Carinae T. R. Gull; 9. Parameters and winds of hot massive stars R. P. Kudritzki and M. A. Urbaneja; 10. Unraveling the Galaxy to find the first stars J. Tumlinson; 11. Optically observable zero-age main-sequence O stars N. R. Walborn; 12. Metallicity-dependent Wolf-Raynet winds P. A. Crowther; 13. Eruptive mass loss in very massive stars and Population III stars N. Smith; 14. From progenitor to afterlife R. A. Chevalier; 15. Pair-production supernovae: theory and observation E. Scannapieco; 16. Cosmic infrared background and Population III: an overview A. Kashlinsky.

  8. Occurrence model for volcanogenic beryllium deposits: Chapter F in Mineral deposit models for resource assessment

    Science.gov (United States)

    Foley, Nora K.; Hofstra, Albert H.; Lindsey, David A.; Seal, Robert R.; Jaskula, Brian W.; Piatak, Nadine M.

    2012-01-01

    Current global and domestic mineral resources of beryllium (Be) for industrial uses are dominated by ores produced from deposits of the volcanogenic Be type. Beryllium deposits of this type can form where hydrothermal fluids interact with fluorine and lithophile-element (uranium, thorium, rubidium, lithium, beryllium, cesium, tantalum, rare earth elements, and tin) enriched volcanic rocks that contain a highly reactive lithic component, such as carbonate clasts. Volcanic and hypabyssal high-silica biotite-bearing topaz rhyolite constitutes the most well-recognized igneous suite associated with such Be deposits. The exemplar setting is an extensional tectonic environment, such as that characterized by the Basin and Range Province, where younger topaz-bearing igneous rock sequences overlie older dolomite, quartzite, shale, and limestone sequences. Mined deposits and related mineralized rocks at Spor Mountain, Utah, make up a unique economic deposit of volcanogenic Be having extensive production and proven and probable reserves. Proven reserves in Utah, as reported by the U.S. Geological Survey National Mineral Information Center, total about 15,900 tons of Be that are present in the mineral bertrandite (Be4Si2O7(OH)2). At the type locality for volcanogenic Be, Spor Mountain, the tuffaceous breccias and stratified tuffs that host the Be ore formed as a result of explosive volcanism that brought carbonate and other lithic fragments to the surface through vent structures that cut the underlying dolomitic Paleozoic sedimentary rock sequences. The tuffaceous sediments and lithic clasts are thought to make up phreatomagmatic base surge deposits. Hydrothermal fluids leached Be from volcanic glass in the tuff and redeposited the Be as bertrandite upon reaction of the hydrothermal fluid with carbonate clasts in lithic-rich sections of tuff. The localization of the deposits in tuff above fluorite-mineralized faults in carbonate rocks, together with isotopic evidence for the

  9. The use of tree-rings and foliage as an archive of volcanogenic cation deposition

    Energy Technology Data Exchange (ETDEWEB)

    Watt, Sebastian F.L. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom)]. E-mail: sebastian.watt@earth.ox.ac.uk; Pyle, David M. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Mather, Tamsin A. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Day, Jason A. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ (United Kingdom); Aiuppa, Alessandro [CFTA - Dipt. Chimica e Fisica della Terra e Applicazioni alle Georisorse, Universita degli Studi di Palermo, Via Archirafi 36, 90123 (Italy)

    2007-07-15

    Tree cores (Pinus nigra ssp. laricio) and leaves (Castanea sativa) from the flanks of Mount Etna, Sicily were analysed by ICP-MS to investigate whether volcanogenic cations within plant material provide an archive of a volcano's temporal and spatial depositional influence. There is significant compositional variability both within and between trees, but no systematic dendrochemical correlation with periods of effusive, explosive or increased degassing activity. Dendrochemistry does not provide a record of persistent but fluctuating volcanic activity. Foliar levels of bioaccumulated cations correspond to modelled plume transport patterns, and map short-term volcanic fumigation. Around the flanks of the volcano foliar variation is greater for volatile cations (Cs, Cd, Pb) than for lithophilic cations (Ba, Sr), consistent with trace-metal supply from volcanic aerosol during quiescent periods. - Dendrochemistry does not provide an archive of persistent volcanic activity.

  10. Volcanogenic Uranium Deposits: Geology, Geochemical Processes, and Criteria for Resource Assessment

    Science.gov (United States)

    Nash, J. Thomas

    2010-01-01

    Felsic volcanic rocks have long been considered a primary source of uranium for many kinds of uranium deposits, but volcanogenic uranium deposits themselves have generally not been important resources. Until the past few years, resource summaries for the United States or the world generally include volcanogenic in the broad category of 'other deposits' because they comprised less than 0.5 percent of past production or estimated resources. Exploration in the United States from the 1940s through 1982 discovered hundreds of prospects in volcanic rocks, of which fewer than 20 had some recorded production. Intensive exploration in the late 1970s found some large deposits, but low grades (less than about 0.10 percent U3O8) discouraged economic development. A few deposits in the world, drilled in the 1980s and 1990s, are now known to contain large resources (>20,000 tonnes U3O8). However, research on ore-forming processes and exploration for volcanogenic deposits has lagged behind other kinds of uranium deposits and has not utilized advances in understanding of geology, geochemistry, and paleohydrology of ore deposits in general and epithermal deposits in particular. This review outlines new ways to explore and assess for volcanogenic deposits, using new concepts of convection, fluid mixing, and high heat flow to mobilize uranium from volcanic source rocks and form deposits that are postulated to be large. Much can also be learned from studies of epithermal metal deposits, such as the important roles of extensional tectonics, bimodal volcanism, and fracture-flow systems related to resurgent calderas. Regional resource assessment is helped by genetic concepts, but hampered by limited information on frontier areas and undiscovered districts. Diagnostic data used to define ore deposit genesis, such as stable isotopic data, are rarely available for frontier areas. A volcanic environment classification, with three classes (proximal, distal, and pre-volcanic structures

  11. Large-scale internal structure in volcanogenic breakout flood deposits: Extensive GPR survey on volcaniclastic deposits

    Science.gov (United States)

    Kataoka, K.; Gomez, C. A.

    2012-12-01

    Large-scale outburst floods from volcanic lakes such as caldera lakes or volcanically dammed river-valleys tend to be voluminous with total discharge of > 1-10s km3 and peak discharge of >10000s to 100000s m3 s-1. Such a large flood can travel long distance and leave sediments and bedforms/landforms extensively with large-scale internal structures, which are difficult to assess from single local sites. Moreover, the sediments and bedforms/landforms are sometimes untraceable, and outcrop information obtained by classical geological and geomorphological field surveys is limited to the dissected/terraced parts of fan body, road cuts and/or large quarries. Therefore, GPR (Ground Penetrating Radar), using the properties of electromagnetic waves' propagation through media, seems best adapted for the appraisal of large-scale subsurface structures. Recently, studies on GPR applications to volcanic deposits have successfully captured images of lava flows and volcaniclastic deposits and proved the usefulness of this method even onto the volcanic areas which often encompass complicated stratigraphy and structures with variable material, grainsize, and ferromagnetic content. Using GPR, the present study aims to understand the large-scale internal structures of volcanogenic flood deposits. The survey was carried out over two volcanogenic flood fan (or apron) sediments in northeast Japan, at Numazawa and Towada volcanoes. The 5 ka Numazawa flood deposits in the Tadami river catchment that has been emplaced by a breakout flood from ignimbrite-dammed valley leaving pumiceous gravelly sediments with meter-sized boulders in the flow path. At Towada volcano, a comparable flood event originating from a breach in the caldera rim emplaced the 13-15 ka Sanbongi fan deposits in the Oirase river valley, which is characterized by a bouldery fan deposits. The GPR data was collected following 200 to 500 m long lateral and longitudinal transects, which were captured using a GPR Pulse

  12. A Collaborative Approach to Monitoring Ambient Volcanogenic Pollution at Sulphur Springs, Saint Lucia.

    Science.gov (United States)

    Joseph, E. P.; Beckles, D. M.; Cox, L.; Jackson, V. B.; Alexander, D.

    2015-12-01

    The role of volcano tourism is recognized as an important contributor to the economy of volcanic islands in the Lesser Antilles. However, if it is to be promoted as a sustainable sector of the tourism industry, visitors, tour operators, and vendors must be made aware of the potential health hazards facing them in volcanic environments. Volcanogenic air pollutants are of primary concern in this setting. In general, no warning signs, guidelines for recreational use, or emissions monitoring currently exists to provide warning to the public to decrease their vulnerability to the potential risks, or to minimize the liability of the agencies managing these areas. Sulphur Springs Park in Saint Lucia is a popular international destination, and concerns about the volcanic emissions and its possible health effect have been raised by visitors, staff, and management of the Park. As part of the responsibility of the UWI, Seismic Research Centre (SRC) to provide volcanic surveillance through its geothermal monitoring programme, a network was established for quantifying the ambient SO2 concentrations at Sulphur Springs in order to assess the potential risk of unsafe exposure. This effort required collaboration with the National Emergency Management Organization (NEMO) of Saint Lucia, as well as the staff and management of the Soufrière Regional Development Foundation (SRDF). Local personnel were trained in the active field sampling and analytical techniques required for the assessment of ambient SO2 concentrations over the monitoring period, thereby contributing to an active community-based effort. This type of approach was also thought to be an effective option for scientists to engage communities as partners in disaster risk reduction. Lessons learnt from this experience are presented for the benefit of other citizen monitoring projects, including its use as a tool for promoting volcanic hazard education, and enhancing communication and understanding between geoscientists and

  13. Volcanogenic Turonian and epiclastics of senonian in the Timok magmatic complex between Bor and the Tupižnica mountain, eastern Serbia

    Directory of Open Access Journals (Sweden)

    Đorđević Miodrag

    2005-01-01

    Full Text Available In the light of the findings presented in this paper, among the volcanic products of the Upper Cretaceous, referred to as "the first volcanic phase" (Drovenik, 1961, two lithostratigraphic units can be singled out within the Timok Magmatic Complex (TMC: - The lower one, consisting of volcanogenic, subaerial, dominantly hornblende andésite volcaniclastic, formed on land, and less abundant volcanic and sub-volcanic-hypoabyssal rocks. It is the main source of sulfide mine­ralization in Bor. It was formed before the Upper Turonian and consists of hornblende andésite and occasionally low biotite. Minor constituents are biotite-hornblende dacite and some andésite and dacite materials con­taining augite in addition to hornblende and biotite. - The upper one, from the Upper Turonian period when the volcanic activity of the region had ended, is marine deposited and epiclastic. Intercalated with Senonian marls, it is composed of land deposited Turonian volcanogenic material of all generations. Fresh material mostly consisting of hornblende andésite volcanoclastics prevails in it. Fresh epiclastics include ore mineral epiclasts. Epiclastics composed of epiclasts of hydro thermally altered rocks were observed which also include ore epiclasts. The ore epiclasts originate from copper ore. The boundary between the volcanogenic Turonian and the epiclastic deposits is a well-recognized unconformity. Table 1 in the text summarizes the main characteristics of the Turonian volcanogenic rocks, primarily those of volcaniclastics, as well as those of epiclastic deposits.

  14. New massive gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Hohm, Olaf; Townsend, Paul K.

    2012-01-01

    We present a brief review of New Massive Gravity, which is a unitary theory of massive gravitons in three dimensions obtained by considering a particular combination of the Einstein-Hilbert and curvature squared terms.

  15. Epidemiology of Massive Transfusion

    DEFF Research Database (Denmark)

    Halmin, Märit; Chiesa, Flaminia; Vasan, Senthil K

    2016-01-01

    OBJECTIVE: There is an increasing focus on massive transfusion, but there is a paucity of comprehensive descriptions of the massively transfused patients and their outcomes. The objective of this study is to describe the incidence rate of massive transfusion, patient characteristics, and the mort...

  16. Massive spin-2 theories

    CERN Document Server

    Folkerts, Sarah; Wintergerst, Nico

    2014-01-01

    We give an introduction to massive spin-2 theories (including massive gravity) and the problem of their non-linear completion. We review the Boulware-Deser ghost problem and two ways to circumvent classic no-go theorems. In turn, massive spin-2 theories are not uniquely defined. In the case of truncated theories, we show that the Boulware-Deser ghost may only be avoided if the derivative structure of the theory is not tuned to be Einsteinian.

  17. Simplifying Massive Contour Maps

    DEFF Research Database (Denmark)

    Arge, Lars; Deleuran, Lasse Kosetski; Mølhave, Thomas

    2012-01-01

    We present a simple, efficient and practical algorithm for constructing and subsequently simplifying contour maps from massive high-resolution DEMs, under some practically realistic assumptions on the DEM and contours.......We present a simple, efficient and practical algorithm for constructing and subsequently simplifying contour maps from massive high-resolution DEMs, under some practically realistic assumptions on the DEM and contours....

  18. Epidemiology of massive transfusion

    DEFF Research Database (Denmark)

    Halmin, M A; Chiesa, F; Vasan, S K

    2015-01-01

    .4% among women transfused for obstetrical bleeding. Mortality increased gradually with age and among all patients massively transfused at age 80 years, only 26% were alive [TABLE PRESENTED] after 5 years. The relative mortality, early after transfusion, was high and decreased with time since transfusion...... transfusion due to obstetrical bleeding constituted 2.6%. Median age at massive transfusion was 67 years and two thirds of the patients were male. The median number of blood components transfused per massive transfusion episode was 22. RBCs formed the majority of blood components transfused. However...

  19. Quantum massive conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    Faria, F.F. [Universidade Estadual do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil)

    2016-04-15

    We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard first order canonical quantization method. It is shown that quantum massive conformal gravity is renormalizable but has ghost states. A possible decoupling of these ghost states at high energies is discussed. (orig.)

  20. Rare sulfur and triple oxygen isotope geochemistry of volcanogenic sulfate aerosols

    Science.gov (United States)

    Bindeman, I. N.; Eiler, J. M.; Wing, B. A.; Farquhar, J.

    2007-05-01

    data presented here are consistent with modification of a chemical mass-dependent fractionation of sulfur isotopes in the volcanic plume by either a kinetic gas phase reaction of volcanic SO 2 with OH and/or a Rayleigh processes involving a residual Rayleigh reactant—volcanic SO 2 gas, rather than a Rayleigh product. These results may also imply at least two removal pathways for SO 2 in volcanic plumes. Above-zero Δ17O values and their positive correlation with δ18O in sulfate can be explained by oxidation by high- δ18O and high- Δ17O compounds such as ozone and radicals such as OH that result from ozone break down. Large caldera-forming eruptions have the highest Δ17O values, and the largest range of δ18O, which can be explained by stratospheric reaction with ozone-derived OH radicals. These results suggest that massive eruptions are capable of causing a temporary depletion of the ozone layer. Such depletion may be many times that of the measured 3-8% depletion following 1991 Pinatubo eruption, if the amount of sulfur dioxide released scales with the amount of ozone depletion.

  1. [Massive pulmonary embolism].

    Science.gov (United States)

    Sanchez, Olivier; Planquette, Benjamin; Wermert, Delphine; Marié, Elisabeth; Meyer, Guy

    2008-10-01

    Massive pulmonary embolism is defined by systemic hypotension or cardiogenic shock. Clinically stable patients with right ventricular dysfunction on echocardiography, elevated brain natriuretic peptide or troponin are usually considered as having sub-massive pulmonary embolism, but this definition is not universally accepted. The time-lag to confirm massive pulmonary embolism should be kept as short as possible and every effort should be done to rely on bedside tests and to avoid patient transfer to the radiology department. D-dimer tests are useless in this setting and the diagnosis is mainly based on clinical probability and bedside echocardiography. When clinical probability is high, right ventricular dilatation assessed by echocardiography allows confirming the diagnosis without additional testing. On the other hand a normal echocardiography does not allow excluding pulmonary embolism. In this setting, a spiral computed tomography is mandatory after the patient has been stabilized. Anticoagulant treatment should be started as soon as pulmonary embolism has been suspected. Supportive care includes oxygen, fluid loading and inotropes. There is little doubt that thrombolytic treatment is of value in patients with massive pulmonary embolism. Conversely, the use of thrombolytic therapy in patients with so-called sub-massive pulmonary embolism remains controversial. Current data do not confirm that thrombolytic therapy decreases mortality in those patients but cannot exclude a clinically significant benefit. A large randomised comparison of heparin and thrombolysis in patients with sub-massive pulmonary embolism is underway to answer this question. Surgical or catheter embolectomy is nowadays only rarely performed in patients with pulmonary embolism. This method can be undertaken in the few patients with persisting shock despite supportive care and who have an absolute contraindication for thrombolytic therapy. Before new data are available there is no special

  2. Massive binary evolution

    Science.gov (United States)

    Podsiadlowski, Philipp

    2010-03-01

    Understanding the evolution of massive binaries is essential for understanding many observed classes of stellar systems, ranging from Algols to X-ray binaries, recycled pulsars, double-neutron-star systems and quite possibly gamma-ray burst sources. Here recent progress and some of the main remaining uncertainties are being reviewed, particularly emphasizing stellar mergers and their possible implications for supernovae like SN 1987A, Thorne-Żytkow objects and η Car-like eruptions. It is shown how binary evolution can affect both the envelope and the core structure of a massive star, explaining - at least in part - the observed diversity of core-collapse supernovae and potentially producing different kick distributions for systems in binaries. Various ideas linking gamma-ray bursts to massive binaries are also being discussed.

  3. Update on massive transfusion.

    Science.gov (United States)

    Pham, H P; Shaz, B H

    2013-12-01

    Massive haemorrhage requires massive transfusion (MT) to maintain adequate circulation and haemostasis. For optimal management of massively bleeding patients, regardless of aetiology (trauma, obstetrical, surgical), effective preparation and communication between transfusion and other laboratory services and clinical teams are essential. A well-defined MT protocol is a valuable tool to delineate how blood products are ordered, prepared, and delivered; determine laboratory algorithms to use as transfusion guidelines; and outline duties and facilitate communication between involved personnel. In MT patients, it is crucial to practice damage control resuscitation and to administer blood products early in the resuscitation. Trauma patients are often admitted with early trauma-induced coagulopathy (ETIC), which is associated with mortality; the aetiology of ETIC is likely multifactorial. Current data support that trauma patients treated with higher ratios of plasma and platelet to red blood cell transfusions have improved outcomes, but further clinical investigation is needed. Additionally, tranexamic acid has been shown to decrease the mortality in trauma patients requiring MT. Greater use of cryoprecipitate or fibrinogen concentrate might be beneficial in MT patients from obstetrical causes. The risks and benefits for other therapies (prothrombin complex concentrate, recombinant activated factor VII, or whole blood) are not clearly defined in MT patients. Throughout the resuscitation, the patient should be closely monitored and both metabolic and coagulation abnormalities corrected. Further studies are needed to clarify the optimal ratios of blood products, treatment based on underlying clinical disorder, use of alternative therapies, and integration of laboratory testing results in the management of massively bleeding patients.

  4. COLA with massive neutrinos

    Science.gov (United States)

    Wright, Bill S.; Winther, Hans A.; Koyama, Kazuya

    2017-10-01

    The effect of massive neutrinos on the growth of cold dark matter perturbations acts as a scale-dependent Newton's constant and leads to scale-dependent growth factors just as we often find in models of gravity beyond General Relativity. We show how to compute growth factors for ΛCDM and general modified gravity cosmologies combined with massive neutrinos in Lagrangian perturbation theory for use in COLA and extensions thereof. We implement this together with the grid-based massive neutrino method of Brandbyge and Hannestad in MG-PICOLA and compare COLA simulations to full N-body simulations of ΛCDM and f(R) gravity with massive neutrinos. Our implementation is computationally cheap if the underlying cosmology already has scale-dependent growth factors and it is shown to be able to produce results that match N-body to percent level accuracy for both the total and CDM matter power-spectra up to klesssim 1 h/Mpc.

  5. Massive prepatellar bursa.

    Science.gov (United States)

    Thompson, Terry L; Simpson, Bonnie M; Burgess, Derrick; Wilson, Robert H

    2006-01-01

    An adult male with cerebral palsy was admitted to our institution with a massive prepatellar bursa. The condition resulted from the patient's use of crawling as a means of household ambulation. The bursa had become infected secondarily, prompting him to seek medical attention. The bursa was excised in its entirety, allowing for relief of his symptoms. The patient expired three years later from unrelated causes.

  6. Dual massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Morand, Kevin, E-mail: Kevin.Morand@lmpt.univ-tours.fr [Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Federation Denis Poisson - CNRS, Parc de Grandmont, 37200 Tours (France); Solodukhin, Sergey N., E-mail: Sergey.Solodukhin@lmpt.univ-tours.fr [Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Federation Denis Poisson - CNRS, Parc de Grandmont, 37200 Tours (France)

    2012-08-29

    The linearized massive gravity in three dimensions, over any maximally symmetric background, is known to be presented in a self-dual form as a first order equation which encodes not only the massive Klein-Gordon type field equation but also the supplementary transverse-traceless conditions. We generalize this construction to higher dimensions. The appropriate dual description in d dimensions, additionally to a (non-symmetric) tensor field h{sub {mu}{nu}}, involves an extra rank-(d-1) field equivalently represented by the torsion rank-3 tensor. The symmetry condition for h{sub {mu}{nu}} arises on-shell as a consequence of the field equations. The action principle of the dual theory is formulated. The focus has been made on four dimensions. Solving one of the fields in terms of the other and putting back in the action one obtains two other equivalent formulations of the theory in which the action is quadratic in derivatives. In one of these representations the theory is formulated entirely in terms of a rank-2 non-symmetric tensor h{sub {mu}{nu}}. This quadratic theory is not identical to the Fierz-Pauli theory and contains the coupling between the symmetric and antisymmetric parts of h{sub {mu}{nu}}. Nevertheless, the only singularity in the propagator is the same as in the Fierz-Pauli theory so that only the massive spin-2 particle is propagating. In the other representation, the theory is formulated in terms of the torsion rank-3 tensor only. We analyze the conditions which follow from the field equations and show that they restrict to 5 degrees of freedom thus producing an alternative description to the massive spin-2 particle. A generalization to higher dimensions is suggested.

  7. Minimal massive 3D gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric; Hohm, Olaf; Merbis, Wout; Routh, Alasdair J.; Townsend, Paul K.

    2014-01-01

    We present an alternative to topologically massive gravity (TMG) with the same 'minimal' bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new 'minimal massive gravity'

  8. Massive fetomaternal hemorrhage

    DEFF Research Database (Denmark)

    Larsen, Rune; Berkowicz, Adela; Lousen, Thea

    2008-01-01

    BACKGROUND: The clearance of D+ red blood cells (RBCs) from the circulation in D- individuals mediated by passively administered anti-D occurs by opsonization with the antibody and subsequent removal in the spleen. Few data exist on the kinetics of clearance of large volumes of D+ RBCs from...... the maternal circulation by anti-D in clinical cases of massive fetomaternal hemorrhage (FMH). CASE REPORT: A 33-year-old D- woman delivered a D+ female infant by emergency cesarean section for suspected fetal anemia. A massive FMH, initially estimated to be approximately 142 mL of RBCs, was found. In addition...... had no detectable anti-D 6 months after delivery. RESULTS: No clearance of fetal cells was apparent after the insufficient dose of IM anti-D. The IV administration of anti-D caused accelerated clearance of D+ fetal RBCs with a t1/2 of 24.5 hours. D+ reticulocytes comprised 4.2 percent of all D+ cells...

  9. Phases of massive gravity

    CERN Document Server

    Dubovsky, S L

    2004-01-01

    We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group using the explicitly covariant language. We find that at general values of mass parameters the massive graviton has six propagating degrees of freedom, and some of them are ghosts or lead to rapid classical instabilities. However, there is a number of different regions in the mass parameter space where massive gravity can be described by a consistent low-energy effective theory with cutoff $\\sim\\sqrt{mM_{Pl}}$ free of rapid instabilities and vDVZ discontinuity. Each of these regions is characterized by certain fine-tuning relations between mass parameters, generalizing the Fierz--Pauli condition. In some cases the required fine-tunings are consequences of the existence of the subgroups of the diffeomorphism group that are left unbroken by the graviton mass. We found two new cases, when the resulting theories have a property of UV insensitivity, i.e. remain well behaved after inclusion of ...

  10. Massively Parallel QCD

    Energy Technology Data Exchange (ETDEWEB)

    Soltz, R; Vranas, P; Blumrich, M; Chen, D; Gara, A; Giampap, M; Heidelberger, P; Salapura, V; Sexton, J; Bhanot, G

    2007-04-11

    The theory of the strong nuclear force, Quantum Chromodynamics (QCD), can be numerically simulated from first principles on massively-parallel supercomputers using the method of Lattice Gauge Theory. We describe the special programming requirements of lattice QCD (LQCD) as well as the optimal supercomputer hardware architectures that it suggests. We demonstrate these methods on the BlueGene massively-parallel supercomputer and argue that LQCD and the BlueGene architecture are a natural match. This can be traced to the simple fact that LQCD is a regular lattice discretization of space into lattice sites while the BlueGene supercomputer is a discretization of space into compute nodes, and that both are constrained by requirements of locality. This simple relation is both technologically important and theoretically intriguing. The main result of this paper is the speedup of LQCD using up to 131,072 CPUs on the largest BlueGene/L supercomputer. The speedup is perfect with sustained performance of about 20% of peak. This corresponds to a maximum of 70.5 sustained TFlop/s. At these speeds LQCD and BlueGene are poised to produce the next generation of strong interaction physics theoretical results.

  11. Analyse des donnees gravimetriques en forage d'un gisement de sulfures massifs volcanogenes dans un contexte geologique complexe

    Science.gov (United States)

    Nackers, Gabrielle-Claudine

    A forward modeling and an inversion code have been developed to study the use of the borehole gravity method for exploration of volcanogenic massif sulphides (VMS) deposits in the Abitibi region of Quebec. Two problems are associated with the gravity method: acquiring data can be a long and costly method in the context where there is a limited quantity of boreholes and the separation of the response caused by the immediate or local geology and the response of deeper and farther formations called the regional. The principal objective of this master's project is to analyse those two major problems by modelling and inverting synthetic data. The specific objectives are the optimisation of the data acquisition settings and the regional-residual anomaly separation. The forward modeling method is based on the prismatic method described by Li and Chouteau (1998). A stochastic approach developed by Shamsipour et al. (2010) is chosen for the inversion and was adapted for borehole data. A density model of a typical VMS ore deposit was designed based on a number of well-known mines in the region of Rouyn-Noranda, Val-d'Or and Matagami. The data acquisition settings include the number of boreholes, their location and data collection sampling in the boreholes. Since the borehole gravity method is a costly geophysics method, it is best to know well the influence of the data acquisition settings to be able to optimise them. A minimum of three boreholes within appropriate distance from the target is required to locate any structure. When four boreholes situated at the detectability range of the deposit are used, it can be located with precision. In the scenario where the borehole gravity method is used to calculate the excess mass of a deposit and to define its structure, at least four boreholes should be used with one intercepting the deposit and fixed densities or gradient constraints must be applied. A 10m sampling interval is recommended. If the position of the deposit is known

  12. S/Se ratio of pyrite from eastern Australian VHMS deposits: implication of magmatic input into volcanogenic hydrothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Huston, D.L. [Geological Survey of Canada, Ottawa, ON (Canada); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Cooke, D.R. [Tasmania Univ., Sandy Bay, TAS (Australia)

    1993-12-31

    The proton microprobe was used to determine the concentrations of over twenty trace elements in pyrite grains from four volcanic-hosted massive sulphide (VHMS) deposits in eastern Australia. Of the elements determined, Se has the most potential in resolving important problems in the genesis of this class of ore deposits. This paper summarises analytical conditions, describes the distribution of Se in pyrite in VHMS deposits as determined in this and other studies, discusses the speciation of Se in hydrothermal fluids, and presents a genetic model on the relative contribution of magmatic versus sea water Se (and S) in VHMS systems. 2 refs., 1 fig.

  13. Simplifying massive planar subdivisions

    DEFF Research Database (Denmark)

    Arge, Lars; Truelsen, Jakob; Yang, Jungwoo

    2014-01-01

    (SORT(N)) I/Os, where N is the size of the decomposition and SORT(N) is the number of I/Os need to sort in the standard external-memory model of computation. Previously, such an algorithm was only known for the special case of contour map simplification. Our algorithm is simple enough to be of practical......We present the first I/O- and practically-efficient algorithm for simplifying a planar subdivision, such that no point is moved more than a given distance εxy and such that neighbor relations between faces (homotopy) are preserved. Under some practically realistic assumptions, our algorithm uses...... interest. In fact, although more general, it is significantly simpler than the previous contour map simplification algorithm. We have implemented our algorithm and present results of experimenting with it on massive real-life data. The experiments confirm that the algorithm is efficient in practice...

  14. Massively parallel mathematical sieves

    Energy Technology Data Exchange (ETDEWEB)

    Montry, G.R.

    1989-01-01

    The Sieve of Eratosthenes is a well-known algorithm for finding all prime numbers in a given subset of integers. A parallel version of the Sieve is described that produces computational speedups over 800 on a hypercube with 1,024 processing elements for problems of fixed size. Computational speedups as high as 980 are achieved when the problem size per processor is fixed. The method of parallelization generalizes to other sieves and will be efficient on any ensemble architecture. We investigate two highly parallel sieves using scattered decomposition and compare their performance on a hypercube multiprocessor. A comparison of different parallelization techniques for the sieve illustrates the trade-offs necessary in the design and implementation of massively parallel algorithms for large ensemble computers.

  15. Massively parallel multicanonical simulations

    Science.gov (United States)

    Gross, Jonathan; Zierenberg, Johannes; Weigel, Martin; Janke, Wolfhard

    2018-03-01

    Generalized-ensemble Monte Carlo simulations such as the multicanonical method and similar techniques are among the most efficient approaches for simulations of systems undergoing discontinuous phase transitions or with rugged free-energy landscapes. As Markov chain methods, they are inherently serial computationally. It was demonstrated recently, however, that a combination of independent simulations that communicate weight updates at variable intervals allows for the efficient utilization of parallel computational resources for multicanonical simulations. Implementing this approach for the many-thread architecture provided by current generations of graphics processing units (GPUs), we show how it can be efficiently employed with of the order of 104 parallel walkers and beyond, thus constituting a versatile tool for Monte Carlo simulations in the era of massively parallel computing. We provide the fully documented source code for the approach applied to the paradigmatic example of the two-dimensional Ising model as starting point and reference for practitioners in the field.

  16. Massive Gravity in Three Dimensions

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Hohm, Olaf; Townsend, Paul K.

    2009-01-01

    A particular higher-derivative extension of the Einstein-Hilbert action in three spacetime dimensions is shown to be equivalent at the linearized level to the (unitary) Pauli-Fierz action for a massive spin-2 field. A more general model, which also includes "topologically-massive" gravity as a

  17. The evolution of massive stars

    Science.gov (United States)

    1982-01-01

    The hypotheses underlying theoretical studies of the evolution of massive model stars with and without mass loss are summarized. The evolutionary tracks followed by the models across theoretical Hertzsprung-Russell (HR) diagrams are compared with the observed distribution of B stars in an HR diagram. The pulsational properties of models of massive star are also described.

  18. The Destructive Birth of Massive Stars and Massive Star Clusters

    Science.gov (United States)

    Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

    2017-01-01

    Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

  19. Fragmentation in massive star formation.

    Science.gov (United States)

    Beuther, Henrik; Schilke, Peter

    2004-02-20

    Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here we present high-spatial-resolution interferometric dust continuum observations disentangling the cluster-like structure of a young massive star-forming region. The derived protocluster mass distribution is consistent with the stellar initial mass function. Thus, fragmentation of the initial massive cores may determine the initial mass function and the masses of the final stars. This implies that stars of all masses can form via accretion processes, and coalescence of intermediate-mass protostars appears not to be necessary.

  20. Coagulation management in massive bleeding.

    Science.gov (United States)

    Griffee, Matthew J; Deloughery, Thomas G; Thorborg, Per A

    2010-04-01

    To update readers on recent literature regarding treatment of coagulopathy for patients with life-threatening bleeding, highlighting emerging therapeutic options, controversial topics, and ongoing clinical trials. Massive transfusion protocols featuring immediate availability of blood products and multidisciplinary communication reduce mortality and conserve resources. There is a growing consensus that immediate administration of plasma and platelet units in a 1: 1: 1 ratio with red cell units reduces early mortality. Lyophilized and recombinant blood product components may have advantages over traditional blood products in certain clinical circumstances. Massive transfusion protocols standardize treatment of the coagulopathy of massive bleeding, leading to rapid restoration of hemostasis and decrease in early mortality.

  1. A not so massive cluster hosting a very massive star

    OpenAIRE

    Ramírez Alegría, S.; Chené, A. -N.; Borissova, J.; Kurtev, R.; Navarro, C.; Kuhn, M; Carballo-Bello, J. A.

    2015-01-01

    We present the first physical characterization of the young open cluster VVV CL041. We spectroscopically observed the cluster main-sequence stellar population and a very-massive star candidate: WR62-2. CMFGEN modeling to our near-infrared spectra indicates that WR62-2 is a very luminous (10$^{6.4\\pm0.2} L_{\\odot}$) and massive ($\\sim80 M_{\\odot}$) star.

  2. Paleoclimatic and paleolatitude settings of accumulation of radiolarian siliceous–volcanogenic sequences in the middle Mesozoic Pacific: Evidence from allochthons of East Asia

    Science.gov (United States)

    Vishnevskaya, V. S.; Filatova, N. I.

    2017-09-01

    Jurassic-Cretaceous siliceous-volcanogenic rocks from nappes of tectonostratigraphic sequences of the East Asia Middle Cretaceous Okhotsk-Koryak orogenic belt are represented by a wide range of geodynamic sedimentation settings: oceanic (near-spreading zones, seamounts, and deep-water basins), marginal seas, and island arcs. The taxonomic compositions of radiolarian communities are used as paleolatitude indicators in the Northern Pacific. In addition, a tendency toward climate change in the Mesozoic is revealed based on these communities: from the warm Triassic to the cold Jurassic with intense warming from the Late Jurassic to the Early Cretaceous. Cretaceous warming led to heating of ocean waters even at moderately high latitudes and to the development of Tethyan radiolarians there. These data are confirmed by a global Cretaceous temperature peak coinciding with a high-activity pulse of the planetary mantle superplume system, which created thermal anomalies and the greenhouse effect. In addition, the Pacific superplume attributed to this system caused accelerated movement of oceanic plates, which resulted in a compression setting on the periphery of the Pacific and the formation of the Okhotsk-Koryak orogenic belt on its northwestern framing in the Middle Cretaceous, where Mesozoic rocks of different geodynamic and latitudinal-climate settings were juxtaposed into allochthonous units.

  3. Astronomy: Quasars signpost massive galaxies

    Science.gov (United States)

    Bouwens, Rychard

    2017-05-01

    The neighbourhoods of extremely bright astronomical objects called quasars in the early Universe have been incompletely probed. Observations suggest that these regions harbour some of the most massive known galaxies. See Letter p.457

  4. Coordination of massively concurrent activities

    NARCIS (Netherlands)

    F. Arbab (Farhad)

    1995-01-01

    textabstractMassively parallel and distributed systems open new horizons for large applications and present new challenges for software technology. Many applications already take advantage of the increased raw computational power provided by such parallel systems to yield significantly shorter

  5. Mobility of plume-derived volcanogenic elements in meteoric water at Nyiragongo volcano (Congo) inferred from the chemical composition of single rainfall events

    Science.gov (United States)

    Liotta, Marcello; Shamavu, Patient; Scaglione, Sarah; D'Alessandro, Walter; Bobrowski, Nicole; Bruno Giuffrida, Giovanni; Tedesco, Dario; Calabrese, Sergio

    2017-11-01

    The chemical composition of single rainfall events was investigated at Nyiragongo volcano (Democratic Republic of Congo) with the aim of determining the relative contributions of plume-derived elements. The different locations of the sampling sites allowed both plume-affected samples (hereafter referred to as ;fumigated samples;) and samples representative of the local background to be collected. The chemical composition of the local background reflects the peculiar geographic features of the area, being influenced by biomass burning, geogenic dust, and biological activity. Conversely, fumigated samples contain large amounts of volcanogenic elements that can be clearly distinguished from the local background. These elements are released into the atmosphere from the persistently boiling lava lake of the Nyiragongo crater and from the neonate lava lake of Nyamulagira. These emissions result in a volcanic plume that includes solid particles, acidic droplets, and gaseous species. The chemical signature of the volcanic emissions appears in falling raindrops as they interact with the plume. HCl and HBr readily dissolve in water, and so their ratio in rain samples reflects that of the volcanic plume. The transport of HF is mediated by the large amount of silicate particles generated at the magma-air interface. SO2 is partially converted into SO42- that dissolves in water. The refractory elements dissolved in rain samples derive from the dissolution of silicate particles, and most of them (Al, Mg, Ca, and Sr) are present at exactly the same molar ratios as in the rocks. In contrast, elements such as Na, K, Rb, Cu, and Pb are enriched relative to the whole-rock composition, suggesting that they are volatilized during magma degassing. After correcting for the dissolution of silicate particles, we can define that the volatility of the elements decreases in the following order: Pb ≫ Rb > K > Na. This finding, which is the first for a volcanic plume, is consistent with

  6. Condensate of massive graviton and dark matter

    OpenAIRE

    Aoki, Katsuki; Maeda, Kei-ichi

    2018-01-01

    We study coherently oscillating massive gravitons in the ghost-free bigravity theory. This coherent field can be interpreted as a condensate of the massive gravitons. We first define the effective energy-momentum tensor of the coherent massive gravitons in a curved spacetime. We then study the background dynamics of the universe and the cosmic structure formation including the effects of the coherent massive gravitons. We find that the condensate of the massive graviton behaves as a dark matt...

  7. Massive gravitons in arbitrary spacetimes

    Science.gov (United States)

    Mazuet, Charles; Volkov, Mikhail S.

    2017-12-01

    We present two different versions of the consistent theory of massive gravitons in arbitrary spacetimes which are simple enough for practical applications. The theory is described by a nonsymmetric rank-2 tensor whose equations of motion imply six algebraic and five differential constraints, reducing the number of independent components to five. The theory reproduces the standard description of massive gravitons in Einstein spaces. In generic spacetimes it does not show the massless limit and always propagates five degrees of freedom, even for the vanishing mass parameter. We illustrate these features by an explicit calculation for a homogeneous and isotropic cosmological background. We find that the gravitons are stable if they are sufficiently massive, hence they may be a part of dark matter at present. We also discuss other possible applications.

  8. Implications of Late Cretaceous U-Pb zircon ages of granitic intrusions cutting ophiolitic and volcanogenic rocks for the assembly of the Tauride allochthon in SE Anatolia (Helete area, Kahramanmaraş Region, SE Turkey)

    Science.gov (United States)

    Nurlu, Nusret; Parlak, Osman; Robertson, Alastair; von Quadt, Albrecht

    2016-01-01

    An assemblage of NE-SW-trending, imbricate thrust slices (c. 26 km E-W long × 6.3 km N-S) of granitic rocks, basic-felsic volcanogenic rocks (Helete volcanics), ophiolitic rocks (Meydan ophiolite) and melange (Meydan melange) is exposed near the Tauride thrust front in SE Anatolia. The volcanogenic rocks were previously assumed to be Eocene because of associated Nummulitic limestones. However, ion probe U-Pb dating of zircons extracted from the intrusive granitic rocks yielded ages of 92.9 ± 2.2-83.1 ± 1.5 Ma (Cenomanian-Campanian). The Helete volcanic unit and the overlying Meydan ophiolitic rocks both are intruded by granitic rocks of similar age and composition. Structurally underlying ophiolite-related melange includes similar-aged, but fragmented granitic intrusions. Major, trace element and rare earth element analyses coupled with electron microprobe analysis of the granitic rocks show that they are metaluminus to peraluminus and calc-alkaline in composition. A magmatic arc setting is inferred from a combination of tectonomagmatic discrimination, ocean ridge granite-normalized multi-element patterns and biotite geochemistry. Sr-Nd-Pb isotope data further suggest that the granitoid rocks were derived from variably mixed mantle and crustal sources. Granitic rocks cutting the intrusive rocks are inferred to have crystallized at ~5-16 km depth. The volcanogenic rocks and granitic rocks originated in a supra-subduction zone setting that was widely developed throughout SE Anatolia. Initial tectonic assembly took place during the Late Cretaceous probably related to northward subduction and accretion beneath the Tauride continent (Keban and Malatya platforms). Initial tectonic assembly was followed by exhumation and then transgression by shelf-depth Nummulitic limestones during Mid-Eocene, as documented in several key outcrops. Final emplacement onto the Arabian continental margin took place during the Early Miocene.

  9. Cleaning Massive Sonar Point Clouds

    DEFF Research Database (Denmark)

    Arge, Lars Allan; Larsen, Kasper Green; Mølhave, Thomas

    2010-01-01

    We consider the problem of automatically cleaning massive sonar data point clouds, that is, the problem of automatically removing noisy points that for example appear as a result of scans of (shoals of) fish, multiple reflections, scanner self-reflections, refraction in gas bubbles, and so on. We...... describe a new algorithm that avoids the problems of previous local-neighbourhood based algorithms. Our algorithm is theoretically I/O-efficient, that is, it is capable of efficiently processing massive sonar point clouds that do not fit in internal memory but must reside on disk. The algorithm is also...

  10. Abdominal Compartment Syndrome complicating massive ...

    African Journals Online (AJOL)

    shobha

    massive hemorrhage from an unusual presentation of ruptured ectopic pregnancy. Robert B. Sanda, Rafeeqa Aziz1, Abdulrazaque Bhutto2, Salah I. Seliem. Departments of Surgery, 1Obstetrics/Gynecology, 2Anaesthesiology, Hail General Hospital, Hail 81451, Saudi Arabia. Correspondence to: Dr. Robert Sanda FRCSI, ...

  11. Sinus Histiocytosis with Massive Lymphadenopathy

    African Journals Online (AJOL)

    1974-03-09

    Mar 9, 1974 ... REPORT OF TWO ADDITIONAL CASES WITH ULTRASTRUCTURAL. OBSERVATIONS c. C. SUNCLAIR~NUTH. L. B. KAHN. C. J. UYS. SUMMARY. Two cases of a recently described entity, 'sinus histio- cytosis with massive lymphadenopathy,' occurring in Black males, are reported. Prominent cervical ...

  12. Massive transfusion in traumatic shock.

    Science.gov (United States)

    Elmer, Jonathan; Wilcox, Susan R; Raja, Ali S

    2013-04-01

    Hemorrhage after trauma is a common cause of death in the United States and globally. The primary goals when managing traumatic shock are the restoration of oxygen delivery to end organs, maintenance of circulatory volume, and prevention of ongoing bleeding through source control and correction of coagulopathy. Achieving these goals may require massive transfusion of blood products. Although use of blood products may be lifesaving, dose-related adverse effects are well described. Complications of massive transfusion include interdependent derangements such as coagulopathy, hypothermia, acidosis, and electrolyte abnormalities, as well as infectious and immunomodulatory phenomena. This article explores the pathogenesis, implications, prevention, and treatment of these complications through the use of massive transfusion protocols. Particular attention is given to the optimal ratio of blood products transfused in large volume resuscitation and prevention of secondary coagulopathy. Observational data indicate that the development and use of a massive transfusion protocol may reduce the morbidity and mortality associated with large-volume resuscitation of patients with hemorrhagic shock. Such protocols should include a pre-defined ratio of packed red blood cells, fresh frozen plasma, and platelets transfused; most commonly, the ratio used is 1:1:1. Additionally, such protocols should monitor for and correct hypothermia, hypofibrinogenemia, and electrolyte disturbances such as hypocalcemia and hyperkalemia. Copyright © 2013. Published by Elsevier Inc.

  13. Uveite Massive a Pseudo - Cristallin

    Directory of Open Access Journals (Sweden)

    G. Chams

    1958-01-01

    Full Text Available The authors report a rare and curious case of massive uveitis with an exudative mass in the anterior chamber rather resembling the crystalline lens."nThey followed up the case clinically and took a series of photographs showing its rapid evolution. The exudative mass was atfor a dislocation of the lens in the anterior chamber

  14. Massive subcutaneous emphysema with pneumoscrotopenis ...

    African Journals Online (AJOL)

    Chest injury commonly leads to subcutaneous emphysema of the chest, neck and face. It is usually non-life threatening. Massive subcutaneous emphysema may occur and very rarely may spread to involve the scrotal sac and subcutaneous tissue planes of the penis to cause pneumoscrotopenis. This case report presents ...

  15. Massively parallel quantum computer simulator

    NARCIS (Netherlands)

    De Raedt, K.; Michielsen, K.; De Raedt, H.; Trieu, B.; Arnold, G.; Richter, M.; Lippert, Th.; Watanabe, H.; Ito, N.

    2007-01-01

    We describe portable software to simulate universal quantum computers on massive parallel Computers. We illustrate the use of the simulation software by running various quantum algorithms on different computer architectures, such as a IBM BlueGene/L, a IBM Regatta p690+, a Hitachi SR11000/J1, a Cray

  16. Abdominal Compartment Syndrome complicating massive ...

    African Journals Online (AJOL)

    ... slow but massive intra-abdominal bleeding caused by a ruptured ectopic pregnancy (REP) in an Arab woman. Due to the unusual nature of the presentation of the REP, the diagnosis proved elusive for over a week until the patient succumbed to hypovolemic shock after losing about 4.2 l inside the peritoneal space.

  17. Cosmological solutions with massive gravitons

    Energy Technology Data Exchange (ETDEWEB)

    Chamseddine, Ali H. [Physics Department, American University of Beirut (Lebanon); Laboratoire de Mathematiques et Physique Theorique CNRS-UMR 6083, Universite de Tours, Parc de Grandmont, 37200 Tours (France); LE STUDIUM, Loire Valley Institute for Advanced Studies, Tours and Orleans (France); I.H.E.S., F-91440 Bures-sur-Yvette (France); Volkov, Mikhail S., E-mail: volkov@lmpt.univ-tours.fr [Laboratoire de Mathematiques et Physique Theorique CNRS-UMR 6083, Universite de Tours, Parc de Grandmont, 37200 Tours (France)

    2011-10-25

    We present solutions describing spatially closed, open, or flat cosmologies in the massive gravity theory within the recently proposed tetrad formulation. We find that the effect of the graviton mass is equivalent to introducing to the Einstein equations a matter source that can consist of several different matter types - a cosmological term, quintessence, gas of cosmic strings, and non-relativistic cold matter.

  18. Permissive tracts for volcanogenic massive sulfide deposits in Mauritania (phase V, deliverable 76): Chapter L1 in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

    Science.gov (United States)

    Taylor, Cliff D.; Horton, John D.

    2012-01-01

    In 1996, at the request of the Government of the Islamic Republic of Mauritania, a team of U.S. Geological Survey (USGS) scientists produced a strategic plan for the acquisition, improvement and modernization of multidisciplinary sets of data to support the growth of the Mauritanian minerals sector and to highlight the geological and mineral exploration potential of the country. In 1999, the Ministry of Petroleum, Energy, and Mines of the Islamic Republic of Mauritania implemented a program for the acquisition of the recommended basic geoscientific information, termed the first Projet de Renforcement Institutionnel du Secteur Minier (Project for Institutional Capacity Building in the Mining Sector, PRISM-I). As a result of the PRISM-I efforts, a great deal of new geological, geophysical, geochemical, remote sensing, and hydrological data became available for evaluation and synthesis. However, the Ministry of Petroleum, Energy, and Mines recognized that additional work was required to extract the full benefit of the data before it could be of greatest use to the international community and of benefit to the Mauritanian minerals and development sector.

  19. Black holes in massive gravity

    CERN Document Server

    Babichev, Eugeny

    2015-01-01

    We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...

  20. Sarcoidosis Presenting as Massive Splenic Infarction

    Directory of Open Access Journals (Sweden)

    Ishita Patel

    2012-01-01

    Full Text Available Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. Granulomatous inflammation involving the spleen is common and associated with splenomegaly. However, massive splenomegaly is a rare occurrence. Infrequently massive splenomegaly can result in splenic infarction. Massive splenic infarction in sarcoidosis has, to our knowledge, not been previously reported. We present a case of a woman presenting with massive splenic infarction and sarcoidosis confirmed by granulomatous inflammation of the liver.

  1. Sarcoidosis presenting as massive splenic infarction.

    Science.gov (United States)

    Patel, Ishita; Ismajli, Mediola; Steuer, Alan

    2012-01-01

    Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. Granulomatous inflammation involving the spleen is common and associated with splenomegaly. However, massive splenomegaly is a rare occurrence. Infrequently massive splenomegaly can result in splenic infarction. Massive splenic infarction in sarcoidosis has, to our knowledge, not been previously reported. We present a case of a woman presenting with massive splenic infarction and sarcoidosis confirmed by granulomatous inflammation of the liver.

  2. Sarcoidosis Presenting as Massive Splenic Infarction

    OpenAIRE

    Ishita Patel; Mediola Ismajli; Alan Steuer

    2012-01-01

    Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. Granulomatous inflammation involving the spleen is common and associated with splenomegaly. However, massive splenomegaly is a rare occurrence. Infrequently massive splenomegaly can result in splenic infarction. Massive splenic infarction in sarcoidosis has, to our knowledge, not been previously reported. We present a case of a woman presenting with massive splenic infarction and sarcoidosis confirmed by granulomatous in...

  3. Massive star clusters in galaxies.

    Science.gov (United States)

    Harris, William E

    2010-02-28

    The ensemble of all star clusters in a galaxy constitutes its star cluster system. In this review, the focus of the discussion is on the ability of star clusters, particularly the systems of old massive globular clusters (GCs), to mark the early evolutionary history of galaxies. I review current themes and key findings in GC research, and highlight some of the outstanding questions that are emerging from recent work.

  4. Magnetic Fields of Massive Stars

    OpenAIRE

    Lundin, Andreas

    2010-01-01

    This paper is an introduction to the subject of magnetic fields on stars, with a focus on hotter stars. Basic astrophysical concepts are explained, including: spectroscopy, stellar classification, general structure and evolution of stars. The Zeeman effect and how absorption line splitting  is used to detect and measure magnetic fields is explained. The properties of a prominent type of magnetic massive star, Ap-stars, are delved into. These stars have very stable, global, roughly dipolar mag...

  5. Formation of Massive Stars: Theoretical Considerations

    Science.gov (United States)

    Yorke, Harold W.

    2008-01-01

    This slide presentation reviews theoretical considerations of the formation of massive stars. It addresses the questions that assuming a gravitationally unstable massive clump, how does enough material become concentrated into a sufficiently small volume within a sufficiently short time? and how does the forming massive star influence its immediate surroundings to limit its mass?

  6. Theoretical Considerations of Massive Star Formation

    Science.gov (United States)

    Yorke, Harold W.

    2006-01-01

    This viewgraph presentation reviews the formation of massive stars. The formation of massive stars is different in many ways from the formation of other stars. The presentation shows the math, and the mechanisms that must be possible for a massive star to form.

  7. Massive branes and creation of branes

    NARCIS (Netherlands)

    Bergshoeff, E; Dorn, H; Lust, D; Weigt, G

    1998-01-01

    We investigate the effective worldvolume theories of p-branes and D-branes in a massive background given by (the bosonic sector of) 10-dimensional massive IIA supergravity ("massive branes"). As an application we discuss the consequences of our results for the anomalous creation of branes.

  8. Massive graviton on a spatial condensate

    Directory of Open Access Journals (Sweden)

    Chunshan Lin

    2014-11-01

    Full Text Available In this paper, we consider the spatial gauge symmetries spontaneously breaking down in GR, and graviton becoming massive on this spatial condensate background. Such a model can be considered as a simplest example of massive gravity. We then apply our massive gravity theory to inflation, and find that the graviton mass removes the IR divergence of the inflationary loop diagram.

  9. Vaidya spacetime in massive gravity's rainbow

    Science.gov (United States)

    Heydarzade, Yaghoub; Rudra, Prabir; Darabi, Farhad; Ali, Ahmed Farag; Faizal, Mir

    2017-11-01

    In this paper, we will analyze the energy dependent deformation of massive gravity using the formalism of massive gravity's rainbow. So, we will use the Vainshtein mechanism and the dRGT mechanism for the energy dependent massive gravity, and thus analyze a ghost free theory of massive gravity's rainbow. We study the energy dependence of a time-dependent geometry, by analyzing the radiating Vaidya solution in this theory of massive gravity's rainbow. The energy dependent deformation of this Vaidya metric will be performed using suitable rainbow functions.

  10. Vaidya spacetime in massive gravity's rainbow

    Directory of Open Access Journals (Sweden)

    Yaghoub Heydarzade

    2017-11-01

    Full Text Available In this paper, we will analyze the energy dependent deformation of massive gravity using the formalism of massive gravity's rainbow. So, we will use the Vainshtein mechanism and the dRGT mechanism for the energy dependent massive gravity, and thus analyze a ghost free theory of massive gravity's rainbow. We study the energy dependence of a time-dependent geometry, by analyzing the radiating Vaidya solution in this theory of massive gravity's rainbow. The energy dependent deformation of this Vaidya metric will be performed using suitable rainbow functions.

  11. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  12. New volcanogenic-eruptive genetic type of diamond occurrence (based on studying the 2012-2013 Fissure Tolbachik Eruption in Kamchatka)

    Science.gov (United States)

    Karpov, Gennady; Anikin, Leonid; Filatov, Stanislav; Silaev, Valery; Petrovsky, Vitaly; Zolotarev, Andrey; Dunin-Barkovsky, Romuald; Volynets, Anna

    2014-05-01

    the instance considered. The above can indicate that Tolbachik diamonds were never affected by mantle anneal. Generally, by their spectroscopic properties, Kamchatka diamonds correspond to the Ib-type whose occurrence among natural diamonds does not exceed 2%. Reported are isolated twinned crystals. Tiny grains of blue moissanite, single grains of pink garnet and pink and blue corundum were found within the association accompanying diamonds (commonly in basalt pores). Often found are thin laminae and filaments of native elements (Fe, Al, Cu), blades or lumpy grains of Cu-Sn (Zn) alloy. Tolbachik diamonds bear no evidence of magmatic corrosion. Data obtained allow us to state the discovery of a new genetic type of diamond occurrence that we suggest to call "volcanogenic-eruptive", or Tolbachik type.

  13. Solid holography and massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Alberte, Lasma [Abdus Salam International Centre for Theoretical Physics,Strada Costiera 11, 34151, Trieste (Italy); Baggioli, Matteo [Institut de Física d’Altes Energies (IFAE),The Barcelona Institute of Science and Technology (BIST), Campus UAB, 08193 Bellaterra, Barcelona (Spain); Department of Physics, Institute for Condensed Matter Theory, University of Illinois,1110 W. Green Street, Urbana, IL 61801 (United States); Khmelnitsky, Andrei [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy); Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE),The Barcelona Institute of Science and Technology (BIST), Campus UAB, 08193 Bellaterra, Barcelona (Spain)

    2016-02-17

    Momentum dissipation is an important ingredient in condensed matter physics that requires a translation breaking sector. In the bottom-up gauge/gravity duality, this implies that the gravity dual is massive. We start here a systematic analysis of holographic massive gravity (HMG) theories, which admit field theory dual interpretations and which, therefore, might store interesting condensed matter applications. We show that there are many phases of HMG that are fully consistent effective field theories and which have been left overlooked in the literature. The most important distinction between the different HMG phases is that they can be clearly separated into solids and fluids. This can be done both at the level of the unbroken spacetime symmetries as well as concerning the elastic properties of the dual materials. We extract the modulus of rigidity of the solid HMG black brane solutions and show how it relates to the graviton mass term. We also consider the implications of the different HMGs on the electric response. We show that the types of response that can be consistently described within this framework is much wider than what is captured by the narrow class of models mostly considered so far.

  14. Interactions in Massive Colliding Wind Binaries

    Directory of Open Access Journals (Sweden)

    Michael F. Corcoran

    2012-03-01

    Full Text Available There are observational difficulties determining dynamical masses of binary star components in the upper HR diagram both due to the scarcity of massive binary systems and spectral and photometric contamination produced by the strong wind outflows in these systems. We discuss how variable X-ray emission in these systems produced by wind-wind collisions in massive binaries can be used to constrain the system parameters, with application to two important massive binaries, Eta Carinae and WR 140.

  15. Clustered Massive Star Formation in Molecular Clouds

    OpenAIRE

    Tan, Jonathan C.

    2005-01-01

    I review some important questions in the field of massive star formation: What are the initial conditions for proto star clusters and how do they arise? What are the initial conditions for individual massive star formation within star clusters? How do massive protostars accumulate their mass? I compare the Turbulent Core Model (McKee & Tan 2003) to several nearby regions, including Orion KL. Here I also discuss the origin of BN's high proper motion.

  16. Massive star population synthesis with binaries

    OpenAIRE

    Vanbeveren, D.; Mennekens, N.

    2015-01-01

    We first give a short historical overview with some key facts of massive star population synthesis with binaries. We then discuss binary population codes and focus on two ingredients which are important for massive star population synthesis and which may be different in different codes. Population simulations with binaries is the third part where we consider the initial massive binary frequency, the RSG/WR and WC/WN and SNII/SNIbc number ratio's, the probable initial rotational velocity distr...

  17. Massive stars in young VVV clusters

    Science.gov (United States)

    Ramírez Alegría, S.; Borissova, J.; Chené, A.-N.

    2017-11-01

    The role of massive stars in the Galactic evolution is crucial. During their lifetime these stars change the kinematics around them through stellar winds, affect the formation of new stars, ionise and chemically enrich the media with the final supernova explosion. But the census of both massive stars and their host clusters is still poor. We expect that still ~100 of galactic massive stellar clusters remains unknown (Hanson & Popescu, 2008).

  18. NLO Antenna Subtraction with Massive Fermions

    OpenAIRE

    Ridder, A. Gehrmann-De; Ritzmann, M.

    2009-01-01

    We present an extension of the antenna subtraction formalism at NLO to include massive final state fermions. The basic ingredients to the subtraction terms, the NLO massive final-final antenna functions are derived and integrated over the corresponding factorised phase space. Those antenna functions account for all soft, collinear and quasi-collinear limits of the QCD matrix elements involving massive fermions in the final state.

  19. On the singularities of massive superstring amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O.

    1987-06-04

    Superstring one-loop amplitudes with massive external states are shown to be in general ill-defined due to internal on-shell propagators. However, we argue that since any massive string state (in the uncompactified theory) has a finite lifetime to decay into massless particles, such amplitudes are not terms in the perturbative expansion of physical S-matrix elements: These can be defined only with massless external states. Consistent massive amplitudes repuire an off-shell formalism.

  20. C++ and Massively Parallel Computers

    Directory of Open Access Journals (Sweden)

    Daniel J. Lickly

    1993-01-01

    Full Text Available Our goal is to apply the software engineering advantages of object-oriented programming to the raw power of massively parallel architectures. To do this we have constructed a hierarchy of C++ classes to support the data-parallel paradigm. Feasibility studies and initial coding can be supported by any serial machine that has a C++ compiler. Parallel execution requires an extended Cfront, which understands the data-parallel classes and generates C* code. (C* is a data-parallel superset of ANSI C developed by Thinking Machines Corporation. This approach provides potential portability across parallel architectures and leverages the existing compiler technology for translating data-parallel programs onto both SIMD and MIMD hardware.

  1. Massive Black Holes and Galaxies

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Evidence has been accumulating for several decades that many galaxies harbor central mass concentrations that may be in the form of black holes with masses between a few million to a few billion time the mass of the Sun. I will discuss measurements over the last two decades, employing adaptive optics imaging and spectroscopy on large ground-based telescopes that prove the existence of such a massive black hole in the Center of our Milky Way, beyond any reasonable doubt. These data also provide key insights into its properties and environment. Most recently, a tidally disrupting cloud of gas has been discovered on an almost radial orbit that reached its peri-distance of ~2000 Schwarzschild radii in 2014, promising to be a valuable tool for exploring the innermost accretion zone. Future interferometric studies of the Galactic Center Black hole promise to be able to test gravity in its strong field limit.

  2. Merlin - Massively parallel heterogeneous computing

    Science.gov (United States)

    Wittie, Larry; Maples, Creve

    1989-01-01

    Hardware and software for Merlin, a new kind of massively parallel computing system, are described. Eight computers are linked as a 300-MIPS prototype to develop system software for a larger Merlin network with 16 to 64 nodes, totaling 600 to 3000 MIPS. These working prototypes help refine a mapped reflective memory technique that offers a new, very general way of linking many types of computer to form supercomputers. Processors share data selectively and rapidly on a word-by-word basis. Fast firmware virtual circuits are reconfigured to match topological needs of individual application programs. Merlin's low-latency memory-sharing interfaces solve many problems in the design of high-performance computing systems. The Merlin prototypes are intended to run parallel programs for scientific applications and to determine hardware and software needs for a future Teraflops Merlin network.

  3. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  4. Cosmological attractors in massive gravity

    CERN Document Server

    Dubovsky, S; Tkachev, I I

    2005-01-01

    We study Lorentz-violating models of massive gravity which preserve rotations and are invariant under time-dependent shifts of the spatial coordinates. In the linear approximation the Newtonian potential in these models has an extra ``confining'' term proportional to the distance from the source. We argue that during cosmological expansion the Universe may be driven to an attractor point with larger symmetry which includes particular simultaneous dilatations of time and space coordinates. The confining term in the potential vanishes as one approaches the attractor. In the vicinity of the attractor the extra contribution is present in the Friedmann equation which, in a certain range of parameters, gives rise to the cosmic acceleration.

  5. Massive ossifying fibroma of mandible.

    Science.gov (United States)

    Saikrishna, D; Shetty, Sujith; Ramya, S

    2014-01-01

    Ossifying fibroma is a benign bone neoplasm often considered to be a type of fibro-osseous lesion. Its origin is believed to be from periodontal membrane, and it shows more predilection toward females. Mandible is more commonly affected than maxilla. This bone tumor consists of highly cellular, fibrous tissue that contains varying amounts of calcified tissue-resembling bone, cementum, or both. Radiographically, the lesions are either completely radiolucent or mixed, depending on the amount of calcification, or are completely radiopaque and surrounded by a radiolucent rim. Ossifying fibroma requires radical surgery, because of the tendency for recurrence and possibility of malignant transformation. Here, we have presented a case of massive ossifying fibroma of mandible in an 80-year-old female.

  6. Massive Star Burps, Then Explodes

    Science.gov (United States)

    2007-04-01

    Berkeley -- In a galaxy far, far away, a massive star suffered a nasty double whammy. On Oct. 20, 2004, Japanese amateur astronomer Koichi Itagaki saw the star let loose an outburst so bright that it was initially mistaken for a supernova. The star survived, but for only two years. On Oct. 11, 2006, professional and amateur astronomers witnessed the star actually blowing itself to smithereens as Supernova 2006jc. Swift UVOT Image Swift UVOT Image (Credit: NASA / Swift / S.Immler) "We have never observed a stellar outburst and then later seen the star explode," says University of California, Berkeley, astronomer Ryan Foley. His group studied the event with ground-based telescopes, including the 10-meter (32.8-foot) W. M. Keck telescopes in Hawaii. Narrow helium spectral lines showed that the supernova's blast wave ran into a slow-moving shell of material, presumably the progenitor's outer layers ejected just two years earlier. If the spectral lines had been caused by the supernova's fast-moving blast wave, the lines would have been much broader. artistic rendering This artistic rendering depicts two years in the life of a massive blue supergiant star, which burped and spewed a shell of gas, then, two years later, exploded. When the supernova slammed into the shell of gas, X-rays were produced. (Credit: NASA/Sonoma State Univ./A.Simonnet) Another group, led by Stefan Immler of NASA's Goddard Space Flight Center, Greenbelt, Md., monitored SN 2006jc with NASA's Swift satellite and Chandra X-ray Observatory. By observing how the supernova brightened in X-rays, a result of the blast wave slamming into the outburst ejecta, they could measure the amount of gas blown off in the 2004 outburst: about 0.01 solar mass, the equivalent of about 10 Jupiters. "The beautiful aspect of our SN 2006jc observations is that although they were obtained in different parts of the electromagnetic spectrum, in the optical and in X-rays, they lead to the same conclusions," says Immler. "This

  7. Massive Star Formation: Accreting from Companion

    Indian Academy of Sciences (India)

    We report the possible accretion from companion in the massive star forming region (G350.69–0.49). This region seems to be a binary system composed of a diffuse object (possible nebulae or UC HII region) and a Massive Young Stellar Object (MYSO) seen in Spitzer IRAC image. The diffuse object and MYSO are ...

  8. On "new massive" 4D gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Fernandez-Melgarejo, J. J.; Rosseel, Jan; Townsend, Paul K.

    We construct a four-dimensional (4D) gauge theory that propagates, unitarily, the five polarization modes of a massive spin-2 particle. These modes are described by a "dual" graviton gauge potential and the Lagrangian is 4th-order in derivatives. As the construction mimics that of 3D "new massive

  9. Massive rectal bleeding from colonic diverticulosis | Olokoba ...

    African Journals Online (AJOL)

    Objectives: This is to describe a case of colonic diverticulosis causing massive rectal bleeding in an elderly Nigerian man. Case report: We highlight a case of a 79 year old man who presented with massive rectal bleeding due to colonic diverticulosis from our centre. Colonoscopy identified multiple diverticula in the ...

  10. 10 billion years of massive Galaxies

    NARCIS (Netherlands)

    Taylor, Edward Nairne Cunningham

    2009-01-01

    The most massive galaxies in the local universe are not forming new stars -- but we don’t know why. As a step towards figuring out why big galaxies stop forming stars, we set out to measure when they stop forming stars. By looking at the colors of massive galaxies have changed over 10 billion

  11. Modelling populations of rotationally mixed massive stars

    NARCIS (Netherlands)

    Brott, I.

    2011-01-01

    Massive stars can be considered as cosmic engines. With their high luminosities, strong stellar winds and violent deaths they drive the evolution of galaxies through-out the history of the universe. Despite the importance of massive stars, their evolution is still poorly understood. Two major issues

  12. On the singularities of massive superstring amplitudes

    NARCIS (Netherlands)

    Foda, O.

    1987-01-01

    Superstring one-loop amplitudes with massive external states are shown to be in general ill-defined due to internal on-shell propagators. However, we argue that since any massive string state (in the uncompactified theory) has a finite lifetime to decay into massless particles, such amplitudes are

  13. XFEM for Thermal Crack of Massive Concrete

    Directory of Open Access Journals (Sweden)

    Guowei Liu

    2013-01-01

    Full Text Available Thermal cracking of massive concrete structures occurs as a result of stresses caused by hydration in real environment conditions. The extended finite element method that combines thermal fields and creep is used in this study to analyze the thermal cracking of massive concrete structures. The temperature field is accurately simulated through an equivalent equation of heat conduction that considers the effect of a cooling pipe system. The time-dependent creep behavior of massive concrete is determined by the viscoelastic constitutive model with Prony series. Based on the degree of hydration, we consider the main properties related to cracking evolving with time. Numerical simulations of a real massive concrete structure are conducted. Results show that the developed method is efficient for numerical calculations of thermal cracks on massive concrete. Further analyses indicate that a cooling system and appropriate heat preservation measures can efficiently prevent the occurrence of thermal cracks.

  14. Causality in 3D massive gravity theories

    Science.gov (United States)

    Edelstein, José D.; Giribet, Gaston; Gómez, Carolina; Kilicarslan, Ercan; Leoni, Matías; Tekin, Bayram

    2017-05-01

    We study the constraints coming from the local causality requirement in various 2 +1 dimensional dynamical theories of gravity. In topologically massive gravity, with a single parity noninvariant massive degree of freedom, and in new massive gravity, with two massive spin-2 degrees of freedom, causality and unitarity are compatible with each other and both require the Newton's constant to be negative. In their extensions, such as the Born-Infeld gravity and the minimal massive gravity the situation is similar and quite different from their higher dimensional counterparts, such as quadratic (e.g., Einstein-Gauss-Bonnet) or cubic theories, where causality and unitarity are in conflict. We study the problem both in asymptotically flat and asymptotically anti-de Sitter spaces.

  15. Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism.

    Science.gov (United States)

    Dolmatova, Elena V; Moazzami, Kasra; Cocke, Thomas P; Elmann, Elie; Vaidya, Pranay; Ng, Arthur F; Satya, Kumar; Narayan, Rajeev L

    Extracorporeal Membrane Oxygenation (ECMO) has been suggested for cardiopulmonary support in patients with massive pulmonary embolism (PE) refractory to other treatment or as bridging to embolectomy. The survival benefit from ECMO in patients with massive PE remains unclear. Here, we describe 5 cases in which ECMO was used as cardiopulmonary support following massive near-fatal pulmonary embolism. The overall mortality in patients with massive PE that received ECMO support was 40%. Death occurred secondary to ECMO-related complication in one case and due to inability to maintain adequate cerebral perfusion despite ECMO support in the second case. ECMO can be considered as a treatment modality for patients with massive PE. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Direct Localization for Massive MIMO

    Science.gov (United States)

    Garcia, Nil; Wymeersch, Henk; Larsson, Erik G.; Haimovich, Alexander M.; Coulon, Martial

    2017-05-01

    Large-scale MIMO systems are well known for their advantages in communications, but they also have the potential for providing very accurate localization thanks to their high angular resolution. A difficult problem arising indoors and outdoors is localizing users over multipath channels. Localization based on angle of arrival (AOA) generally involves a two-step procedure, where signals are first processed to obtain a user's AOA at different base stations, followed by triangulation to determine the user's position. In the presence of multipath, the performance of these methods is greatly degraded due to the inability to correctly detect and/or estimate the AOA of the line-of-sight (LOS) paths. To counter the limitations of this two-step procedure which is inherently sub-optimal, we propose a direct localization approach in which the position of a user is localized by jointly processing the observations obtained at distributed massive MIMO base stations. Our approach is based on a novel compressed sensing framework that exploits channel properties to distinguish LOS from non-LOS signal paths, and leads to improved performance results compared to previous existing methods.

  17. Nonsingular universe in massive gravity's rainbow

    Science.gov (United States)

    Hendi, S. H.; Momennia, M.; Eslam Panah, B.; Panahiyan, S.

    2017-06-01

    One of the fundamental open questions in cosmology is whether we can regard the universe evolution without singularity like a Big Bang or a Big Rip. This challenging subject stimulates one to regard a nonsingular universe in the far past with an arbitrarily large vacuum energy. Considering the high energy regime in the cosmic history, it is believed that Einstein gravity should be corrected to an effective energy dependent theory which could be acquired by gravity's rainbow. On the other hand, employing massive gravity provided us with solutions to some of the long standing fundamental problems of cosmology such as cosmological constant problem and self acceleration of the universe. Considering these aspects of gravity's rainbow and massive gravity, in this paper, we initiate studying FRW cosmology in the massive gravity's rainbow formalism. At first, we show that although massive gravity modifies the FRW cosmology, but it does not itself remove the big bang singularity. Then, we generalize the massive gravity to the case of energy dependent spacetime and find that massive gravity's rainbow can remove the early universe singularity. We bring together all the essential conditions for having a nonsingular universe and the effects of both gravity's rainbow and massive gravity generalizations on such criteria are determined.

  18. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  19. Venus - Volcano With Massive Landslides

    Science.gov (United States)

    1992-01-01

    This Magellan full-resolution mosaic which covers an area 143 by 146 kilometers (89 by 91 miles) is centered at 55 degrees north latitude, 266 degrees east longitude. The bright feature, slightly south of center is interpreted to be a volcano, 15-20 kilometers (9.3 to 12.4 miles) in diameter with a large apron of blocky debris to its right and some smaller aprons to its left. A preferred explanation is that several massive catastrophic landslides dropped down steep slopes and were carried by their momentum out into the smooth, dark lava plains. At the base of the east-facing or largest scallop on the volcano is what appears to be a large block of coherent rock, 8 to 10 kilometers (5 to 6 miles) in length. The similar margin of both the scallop and block and the shape in general is typical of terrestrial slumped blocks (masses of rock which slide and rotate down a slope instead of breaking apart and tumbling). The bright lobe to the south of the volcano may either be a lava flow or finer debris from other landslides. This volcanic feature, characterized by its scalloped flanks is part of a class of volcanoes called scalloped or collapsed domes of which there are more than 80 on Venus. Based on the chute-like shapes of the scallops and the existence of a spectrum of intermediate to well defined examples, it is hypothesized that all of the scallops are remnants of landslides even though the landslide debris is often not visible. Possible explanations for the missing debris are that it may have been covered by lava flows, the debris may have weathered or that the radar may not be recognizing it because the individual blocks are too small

  20. Using massive digital libraries a LITA guide

    CERN Document Server

    Weiss, Andrew

    2014-01-01

    Some have viewed the ascendance of the digital library as some kind of existential apocalypse, nothing less than the beginning of the end for the traditional library. But Weiss, recognizing the concept of the library as a ""big idea"" that has been implemented in many ways over thousands of years, is not so gloomy. In this thought-provoking and unabashedly optimistic book, he explores how massive digital libraries are already adapting to society's needs, and looks ahead to the massive digital libraries of tomorrow, coveringThe author's criteria for defining massive digital librariesA history o

  1. Management of massive and nonmassive pulmonary embolism

    Science.gov (United States)

    Sekhri, Vishal; Mehta, Nimeshkumar; Rawat, Naveen; Lehrman, Stuart G.

    2012-01-01

    Massive pulmonary embolism (PE) is characterized by systemic hypotension (defined as a systolic arterial pressure pulmonary embolism has a high mortality rate despite advances in diagnosis and therapy. A subgroup of patients with nonmassive PE who are hemodynamically stable but with right ventricular (RV) dysfunction or hypokinesis confirmed by echocardiography is classified as submassive PE. Their prognosis is different from that of others with non-massive PE and normal RV function. This article attempts to review the evidence-based risk stratification, diagnosis, initial stabilization, and management of massive and nonmassive pulmonary embolism. PMID:23319967

  2. Massive star archeology in globular clusters

    Science.gov (United States)

    Chantereau, W.; Charbonnel, C.; Meynet, G.

    2015-01-01

    Globular clusters are among the oldest structures in the Universe and they host today low-mass stars and no gas. However, there has been a time when they formed as gaseous objects hosting a large number of short-lived, massive stars. Many details on this early epoch have been depicted recently through unprecedented dissection of low-mass globular cluster stars via spectroscopy and photometry. In particular, multiple populations have been identified, which bear the nucleosynthetic fingerprints of the massive hot stars disappeared a long time ago. Here we discuss how massive star archeology can be done through the lense of these multiple populations.

  3. Inside-out formation of massive galaxies

    Science.gov (United States)

    de la Rosa, I. G.

    2017-03-01

    A significant fraction of the present day massive galaxies have compact cores embedded inside their disks or halos. Strikingly, those compact cores are similar to the massive high-redshift quiescent compact galaxies, nicknamed red-nuggets. We present observational evidence supporting an inside-out formation scenario, where present-day massive galaxies can begin as dense spheroidal cores (red-nuggets), around which either a spheroidal halo or a disk are accreted later. This contribution is based on the paper by de la Rosa et al. (2016).

  4. Current management of massive hemorrhage in trauma

    DEFF Research Database (Denmark)

    Johansson, Pär I; Stensballe, Jakob; Ostrowski, Sisse R

    2012-01-01

    ABSTRACT: Hemorrhage remains a major cause of potentially preventable deaths. Trauma and massive transfusion are associated with coagulopathy secondary to tissue injury, hypoperfusion, dilution, and consumption of clotting factors and platelets. Concepts of damage control surgery have evolved...

  5. Can massive stars be formed by accretion?

    Science.gov (United States)

    Yorke, H. W.

    2000-01-01

    Radiative effects strongly hinder the formation of massive stars. A necessary condition for accretion growth of a hydrostatic object up to high masses is the formation of and accretion through a circumstellar disk.

  6. Massive Subcutaneous Emphysema in Robotic Sacrocolpopexy

    Science.gov (United States)

    Celik, Hatice; Cremins, Angela; Jones, Keisha A.

    2013-01-01

    The advent of robotic surgery has increased the popularity of laparoscopic sacrocolpopexy. Carbon dioxide insufflation, an essential component of laparoscopy, may rarely cause massive subcutaneous emphysema, which may be coincident with life-threatening situations such as hypercarbia, pneumothorax, and pneumomediastinum. Although the literature contains several reports of massive subcutaneous emphysema after a variety of laparoscopic procedures, we were not able to identify any report of this complication associated with laparoscopic or robotic sacrocolpopexy. Massive subcutaneous emphysema occurred in 3 women after robotic sacrocolpopexy in our practice. The patients had remarkable but reversible physical deformities lasting up to 1 week. A valveless endoscopic dynamic pressure system was used in all 3 of our cases. Our objective is to define the risk of massive subcutaneous emphysema during robotic sacrocolpopexy in light of these cases and discuss probable predisposing factors including the use of valveless endoscopic dynamic pressure trocars. PMID:23925018

  7. Black holes in massive conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    Myung, Yun Soo, E-mail: ysmyung@inje.ac.kr

    2014-03-07

    We analyze the classical stability of Schwarzschild black hole in massive conformal gravity which was recently proposed for another massive gravity model. This model in the Jordan frame is conformally equivalent to the Einstein–Weyl gravity in the Einstein frame. The coupled linearized Einstein equation is decomposed into the traceless and trace equation when one chooses 6m{sup 2}φ=δR. Solving the traceless equation exhibits unstable modes featuring the Gregory–Laflamme s-mode instability of five-dimensional black string, while we find no unstable modes when solving the trace equation. It is shown that the instability of the black hole in massive conformal gravity arises from the massiveness where the geometry of extra dimension trades for mass.

  8. Towards Very Large Aperture Massive MIMO

    DEFF Research Database (Denmark)

    Oliveras Martínez, Àlex; De Carvalho, Elisabeth; Nielsen, Jesper Ødum

    2014-01-01

    Massive MIMO is a new technique for wireless communications that claims to offer very high system throughput and energy efficiency in multi-user scenarios. The cost is to add a very large number of antennas at the base station. Theoretical research has probed these benefits, but very few measurem......Massive MIMO is a new technique for wireless communications that claims to offer very high system throughput and energy efficiency in multi-user scenarios. The cost is to add a very large number of antennas at the base station. Theoretical research has probed these benefits, but very few...... measurements have showed the potential of Massive MIMO in practice. We investigate the properties of measured Massive MIMO channels in a large indoor venue. We describe a measurement campaign using 3 arrays having different shape and aperture, with 64 antennas and 8 users with 2 antennas each. We focus...

  9. Magneto-asteroseismology of massive magnetic pulsators

    Science.gov (United States)

    Buysschaert, B.; Neiner, C.; Aerts, C.

    2017-11-01

    Simultaneously and coherently studying the large-scale magnetic field and the stellar pulsations of a massive star provides strong complementary diagnostics suitable for detailed stellar modelling. This hybrid method is called magneto-asteroseismology and permits the determination of the internal structure and conditions within magnetic massive pulsators, for example the effect of magnetism on non-standard mixing processes. Here, we overview this technique, its requirements, and list the currently known suitable stars to apply the method.

  10. Massive Star and Star Cluster Formation

    OpenAIRE

    Tan, Jonathan C.

    2006-01-01

    I review the status of massive star formation theories: accretion from collapsing, massive, turbulent cores; competitive accretion; and stellar collisions. I conclude the observational and theoretical evidence favors the first of these models. I then discuss: the initial conditions of star cluster formation as traced by infrared dark clouds; the cluster formation timescale; and comparison of the initial cluster mass function in different galactic environments.

  11. BLITZEN: A highly integrated massively parallel machine

    Science.gov (United States)

    Blevins, D. W.; Davis, E. W.; Heaton, R. A.; Reif, J. H.

    1988-01-01

    The architecture and VLSI design of a new massively parallel processing array chip are described. The BLITZEN processing element array chip, which contains 1.1 million transistors, serves as the basis for a highly integrated, miniaturized, high-performance, massively parallel machine that is currently under development. Each processing element has 1K bits of static RAM and performs bit-serial processing with functional elements for arithmetic, logic, and shifting.

  12. BLITZEN - A highly integrated massively parallel machine

    Science.gov (United States)

    Blevins, D. W.; Davis, E. W.; Heaton, R. A.; Reif, J. H.

    1988-01-01

    The architecture and VLSI design of a new massively parallel processing array chip are described. The BLITZEN processing element array chip, which contains 1.1 million transistors, serves as the basis for a highly integrated, miniaturized, high-performance, massively parallel machine that is currently under development. Each processing element has 1K bits of static RAM and performs bit-serial processing with functional elements for arithmetic, logic, and shifting.

  13. Integrating Building Functions into Massive External Walls

    Directory of Open Access Journals (Sweden)

    Ahmed Hisham Hafez

    2017-11-01

    Full Text Available Well into the twentieth century, brick and stone were the materials used. Bricklaying and stonemasonry were the construction technologies employed for the exterior walls of virtually all major structures. However, with the rise in quality of life, the massive walls alone became incapable of fulfilling all the developed needs. Adjacent systems and layers had then to be attached to the massive layer. Nowadays, the external wall is usually composed of a layered construction. Each external wall function is usually represented by a separate layer or system. The massive layer of the wall is usually responsible for the load-bearing function. Traditional massive external walls vary in terms of their external appearance, their composition and attached layers. However, their design and construction process is usually a repeated process. It is a linear process where each discipline is concerned with a separate layer or system. These disciplines usually take their tasks away and bring them back to be re-integrated in a layered manner. New massive technologies with additional function have recently become available. Such technologies can provide the external wall with other functions in addition to its load-bearing function. The purpose of this research is to map the changes required to the traditional design and construction process when massive technologies with additional function are applied in external walls. Moreover, the research aims at assessing the performance of massive solutions with additional function when compared to traditional solutions in two different contexts, the Netherlands and Egypt. Through the analysis of different additional function technologies in external walls, a guidance scheme for different stakeholders is generated. It shows the expected process changes as related to the product level and customization level. Moreover, the research concludes that the performance of additional insulating technologies, and specifically

  14. Forming spectroscopic massive protobinaries by disc fragmentation

    Science.gov (United States)

    Meyer, D. M.-A.; Kuiper, R.; Kley, W.; Johnston, K. G.; Vorobyov, E.

    2018-01-01

    The surroundings of massive protostars constitute an accretion disc which has numerically been shown to be subject to fragmentation and responsible for luminous accretion-driven outbursts. Moreover, it is suspected to produce close binary companions which will later strongly influence the star's future evolution in the Hertzsprung-Russel diagram. We present three-dimensional gravitation-radiation-hydrodynamic numerical simulations of 100 M⊙ pre-stellar cores. We find that accretion discs of young massive stars violently fragment without preventing the (highly variable) accretion of gaseous clumps on to the protostars. While acquiring the characteristics of a nascent low-mass companion, some disc fragments migrate on to the central massive protostar with dynamical properties showing that its final Keplerian orbit is close enough to constitute a close massive protobinary system, having a young high- and a low-mass components. We conclude on the viability of the disc fragmentation channel for the formation of such short-period binaries, and that both processes - close massive binary formation and accretion bursts - may happen at the same time. FU-Orionis-type bursts, such as observed in the young high-mass star S255IR-NIRS3, may not only indicate ongoing disc fragmentation, but also be considered as a tracer for the formation of close massive binaries - progenitors of the subsequent massive spectroscopic binaries - once the high-mass component of the system will enter the main-sequence phase of its evolution. Finally, we investigate the Atacama Large (sub-)Millimeter Array observability of the disc fragments.

  15. Massive relic galaxies prefer dense environments

    Science.gov (United States)

    Peralta de Arriba, Luis; Quilis, Vicent; Trujillo, Ignacio; Cebrián, María; Balcells, Marc

    2016-09-01

    We study the preferred environments of z ∼ 0 massive relic galaxies (M⋆ ≳ 1010 M⊙ galaxies with little or no growth from star formation or mergers since z ∼ 2). Significantly, we carry out our analysis on both a large cosmological simulation and an observed galaxy catalogue. Working on the Millennium I-WMAP7 simulation we show that the fraction of today massive objects which have grown less than 10 per cent in mass since z ∼ 2 is ∼0.04 per cent for the whole massive galaxy population with M⋆ ≳ 1010 M⊙. This fraction rises to ∼0.18 per cent in galaxy clusters, confirming that clusters help massive galaxies remain unaltered. Simulations also show that massive relic galaxies tend to be closer to cluster centres than other massive galaxies. Using the New York University Value-Added Galaxy Catalogue, and defining relics as M⋆ ≳ 1010 M⊙ early-type galaxies with colours compatible with single-stellar population ages older than 10 Gyr, and which occupy the bottom 5-percentile in the stellar mass-size distribution, we find 1.11 ± 0.05 per cent of relics among massive galaxies. This fraction rises to 2.4 ± 0.4 per cent in high-density environments. Our findings point in the same direction as the works by Poggianti et al. and Stringer et al. Our results may reflect the fact that the cores of the clusters are created very early on, hence the centres host the first cluster members. Near the centres, high-velocity dispersions and harassment help cluster core members avoid the growth of an accreted stellar envelope via mergers, while a hot intracluster medium prevents cold gas from reaching the galaxies, inhibiting star formation.

  16. Massive panniculectomy results in improved functional outcome.

    Science.gov (United States)

    Evans, Chadrick; Debord, James; Howe, Heather; Marshall, John Stephen; Rossi, Thomas; Owolabi, Michael

    2014-03-01

    Panniculus morbidus is a large abdominal apron found in morbidly obese patients. This condition creates a vicious cycle of weight gain and functional incapacity. Our study assessed the functional improvement in patients undergoing massive panniculectomy. A retrospective review of panniculectomies performed from 1994 to 2012 was conducted. Twenty-seven patients with resections >20 lbs were selected. Data on demographics, operative details, complications, and pre- and postoperative functional capacity (using the Steinbrocker Functional Classification) were collected. The preoperative mean body mass index was 58 kg/m(2), with a mean resection weight of 33 lbs. The overall complication rate was 74%. A statistically significant improvement in functional capacity (preop mean 3.7 vs postop mean 2.0; P massive panniculectomy is often the only treatment available. Our data suggest that massive panniculectomy is a viable option for patients functionally incapacitated by panniculus morbidus. Published by Elsevier Inc.

  17. Limited Feedback Precoding for Massive MIMO

    Directory of Open Access Journals (Sweden)

    Xin Su

    2013-01-01

    Full Text Available The large-scale array antenna system with numerous low-power antennas deployed at the base station, also known as massive multiple-input multiple-output (MIMO, can provide a plethora of advantages over the classical array antenna system. Precoding is important to exploit massive MIMO performance, and codebook design is crucial due to the limited feedback channel. In this paper, we propose a new avenue of codebook design based on a Kronecker-type approximation of the array correlation structure for the uniform rectangular antenna array, which is preferable for the antenna deployment of massive MIMO. Although the feedback overhead is quite limited, the codebook design can provide an effective solution to support multiple users in different scenarios. Simulation results demonstrate that our proposed codebook outperforms the previously known codebooks remarkably.

  18. Gyromagnetic ratio of a massive body.

    Science.gov (United States)

    Cohen, J. M.; Tiomno, J.; Wald, R. M.

    1973-01-01

    It is well known that the gyromagnetic ratio (g factor) of a classical, slowly rotating body whose charge density is proportional to its mass density must be equal to unity. However, if the body is very massive, the spacetime curvature effects of general relativity become important and the result g = 1 is no longer valid. We calculate here the gyromagnetic ratio of a slowly rotating, massive shell with uniform charge density. When the shell is large compared with the Schwarzschild radius we have g = 1, but as the shell becomes more massive the g factor increases. In the limit as the shell approaches its Schwarzschild radius we obtain g approaching 2 (the same value as for an electron).

  19. Massive Particle Reflection from Moving Mirrors

    Science.gov (United States)

    Sfarti, Adrian

    2016-09-01

    We investigate the reflection of massive particles from moving mirrors. The adoption of the formalism based on the energy-momentum allowed us to derive the most general set of formulas, valid for massive and, in the limit, also for massless particles. We show that the momentum change of the reflecting particle always lies along the normal to the mirror, independent of the mirror speed. The subject is interesting not only to physicists designing concentrators for fascicles of massive particles and electron microscopes but also to computer scientists working in raytracing operating in the photon sector. The paper, far from being only theoretical, has profound and novel practical applications in both domains of engineering design and computer science.

  20. Massive transfusion and nonsurgical hemostatic agents.

    Science.gov (United States)

    Perkins, Jeremy G; Cap, Andrew P; Weiss, Brendan M; Reid, Thomas J; Bolan, Charles D; Bolan, Charles E

    2008-07-01

    Hemorrhage in trauma is a significant challenge, accounting for 30% to 40% of all fatalities, second only to central nervous system injury as a cause of death. However, hemorrhagic death is the leading preventable cause of mortality in combat casualties and typically occurs within 6 to 24 hrs of injury. In cases of severe hemorrhage, massive transfusion may be required to replace more than the entire blood volume. Early prediction of massive transfusion requirements, using clinical and laboratory parameters, combined with aggressive management of hemorrhage by surgical and nonsurgical means, has significant potential to reduce early mortality. Although the classification of massive transfusion varies, the most frequently used definition is ten or more units of blood in 24 hrs. Transfusion of red blood cells is intended to restore blood volume, tissue perfusion, and oxygen-carrying capacity; platelets, plasma, and cryoprecipitate are intended to facilitate hemostasis through prevention or treatment of coagulopathy. Massive transfusion is uncommon in civilian trauma, occurring in only 1% to 3% of trauma admissions. As a result of a higher proportion of penetrating injury in combat casualties, it has occurred in approximately 8% of Operation Iraqi Freedom admissions and in as many as 16% during the Vietnam conflict. Despite its potential to reduce early mortality, massive transfusion is not without risk. It requires extensive blood-banking resources and is associated with high mortality. This review describes the clinical problems associated with massive transfusion and surveys the nonsurgical management of hemorrhage, including transfusion of blood products, use of hemostatic bandages/agents, and treatment with hemostatic medications.

  1. Massive gravity and Fierz-Pauli theory

    Energy Technology Data Exchange (ETDEWEB)

    Blasi, Alberto [Universita di Genova, Dipartimento di Fisica, Genova (Italy); Maggiore, Nicola [I.N.F.N.-Sezione di Genova, Genoa (Italy)

    2017-09-15

    Linearized gravity is considered as an ordinary gauge field theory. This implies the need for gauge fixing in order to have well-defined propagators. Only after having achieved this, the most general mass term is added. The aim of this paper is to study of the degrees of freedom of the gauge fixed theory of linearized gravity with mass term. The main result is that, even outside the usual Fierz-Pauli constraint on the mass term, it is possible to choose a gauge fixing belonging to the Landau class, which leads to a massive theory of gravity with the five degrees of freedom of a spin-2 massive particle. (orig.)

  2. A Massively Parallel Face Recognition System

    Directory of Open Access Journals (Sweden)

    Ari Paasio

    2006-12-01

    Full Text Available We present methods for processing the LBPs (local binary patterns with a massively parallel hardware, especially with CNN-UM (cellular nonlinear network-universal machine. In particular, we present a framework for implementing a massively parallel face recognition system, including a dedicated highly accurate algorithm suitable for various types of platforms (e.g., CNN-UM and digital FPGA. We study in detail a dedicated mixed-mode implementation of the algorithm and estimate its implementation cost in the view of its performance and accuracy restrictions.

  3. A Massively Parallel Face Recognition System

    Directory of Open Access Journals (Sweden)

    Lahdenoja Olli

    2007-01-01

    Full Text Available We present methods for processing the LBPs (local binary patterns with a massively parallel hardware, especially with CNN-UM (cellular nonlinear network-universal machine. In particular, we present a framework for implementing a massively parallel face recognition system, including a dedicated highly accurate algorithm suitable for various types of platforms (e.g., CNN-UM and digital FPGA. We study in detail a dedicated mixed-mode implementation of the algorithm and estimate its implementation cost in the view of its performance and accuracy restrictions.

  4. Massive intracerebral hemorrhage associated with Wegener granulomatosis.

    Science.gov (United States)

    Ceri, Mevlut; Ortabozkoyun, Levent; Unverdi, Selman; Kirac, Mustafa; Duranay, Murat

    2012-06-01

    Wegener granulomatosis (WG) is a necrotizing granulomatous vasculitis that predominantly affects airways and kidneys. But central nervous system involvement (7-11%) is an uncommon. Massive ICH may occur in the course of WG, and this serious condition is related with high risk of mortality. Therefore, the new treatment strategies may be considered in addition to classical practices in serious organ involvement and recurrent attack. Here, we present an adult patient with WG whose disease was complicated by a massive intracerebral hemorrhage (ICH), which subsequently led to death.

  5. Geology, geochemistry, and genesis of the Greens Creek massive sulfide deposit, Admiralty Island, southeastern Alaska

    Science.gov (United States)

    Taylor, Cliff D.; Johnson, Craig A.

    2010-01-01

    In 1996, a memorandum of understanding was signed by representatives of the U.S. Geological Survey and Kennecott Greens Creek Mining Company to initiate a cooperative applied research project focused on the Greens Creek massive sulfide deposit in southeastern Alaska. The goals of the project were consistent with the mandate of the U.S. Geological Survey Mineral Resources Program to maintain a leading role in national mineral deposits research and with the need of Kennecott Greens Creek Mining Company to further development of the Greens Creek deposit and similar deposits in Alaska and elsewhere. The memorandum enumerated four main research priorities: (1) characterization of protoliths for the wall rocks, and elucidation of their alteration histories, (2) determination of the ore mineralogy and paragenesis, including metal residences and metal zonation within the deposit, (3) determination of the ages of events important to ore formation using both geochronology and paleontology, and (4) development of computer models that would allow the deposit and its host rocks to be examined in detail in three dimensions. The work was carried out by numerous scientists of diverse expertise over a period of several years. The written results, which are contained in this Professional Paper, are presented by 21 authors: 13 from the U.S. Geological Survey, 4 from Kennecott Greens Creek Mining Company, 2 from academia, and 2 from consultants. The Greens Creek deposit (global resource of 24.2 million tons at an average grade of 13.9 percent zinc, 5.1 percent lead, 0.15 troy ounce per ton gold, and 19.2 troy ounces per ton silver at zero cutoff) formed in latest Triassic time during a brief period of rifting of the Alexander terrane. The deposit exhibits a range of syngenetic, diagenetic, and epigenetic features that are typical of volcanogenic (VMS), sedimentary exhalative (SEDEX), and Mississippi Valley-type (MVT) genetic models. In the earliest stages of rifting, formation of

  6. FRW Cosmological Perturbations in Massive Bigravity

    CERN Document Server

    Comelli, D; Pilo, L

    2014-01-01

    Cosmological perturbations of FRW solutions in ghost free massive bigravity, including also a second matter sector, are studied in detail. At early time, we find that sub horizon exponential instabilities are unavoidable and they lead to a premature departure from the perturbative regime of cosmological perturbations.

  7. Massive Open Online Courses and Economic Sustainability

    Science.gov (United States)

    Liyanagunawardena, Tharindu R.; Lundqvist, Karsten O.; Williams, Shirley A.

    2015-01-01

    Millions of users around the world have registered on Massive Open Online Courses (MOOCs) offered by hundreds of universities (and other organizations) worldwide. Creating and offering these courses costs thousands of pounds. However, at present, revenue generated by MOOCs is not sufficient to offset these costs. The sustainability of MOOCs is a…

  8. More on massive 3D gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Hohm, Olaf; Townsend, Paul K.

    We explore the space of static solutions of the recently discovered three-dimensional "new massive gravity" (NMG), allowing for either sign of the Einstein-Hilbert term and a cosmological term parametrized by a dimensionless constant lambda. For lambda = -1 we find black hole solutions asymptotic

  9. Integrating Building Functions into Massive External Walls

    NARCIS (Netherlands)

    Hafez, A.H.

    2016-01-01

    Well into the twentieth century, brick and stone were the materials used in external walls. Bricklaying and stonemasonry were the construction technologies employed for the exterior walls of virtually all major structures. However, with the rise in quality of life, the massive walls alone became

  10. BPS black hole horizons from massive IIA

    Science.gov (United States)

    Guarino, Adolfo

    2017-08-01

    The maximal four-dimensional supergravity with a dyonic ISO(7) gauging that arises from the reduction of massive IIA on a six-sphere has recently been shown to accommodate static BPS black holes with hyperbolic horizons. When restricted to the N=2 subsector that retains one vector multiplet and the universal hypermultiplet, the attractor mechanism was shown to fix both the vector charges and the scalar fields at the horizon to a unique configuration in terms of the gauging parameters. In order to assess the (non-)uniqueness of BPS black hole horizons from massive IIA, we extend the study of the attractor mechanism to other N=2 subsectors including additional matter multiplets. We note that, while extending the hypermultiplet sector does not modify the set of solutions to the attractor equations, the inclusion of additional vector multiplets results in new hyperbolic/spherical horizon configurations containing free parameters. The model with three vector multiplets and the universal hypermultiplet, which is the massive IIA analogue of the STU-model from M-theory, may play a relevant role in massive IIA holography.

  11. Very Massive Stars in the local Universe

    NARCIS (Netherlands)

    Vink, J.S.; Heger, A.; Krumholz, M.R.; Puls, J.; Banerjee, S.; Castro, N.; Chen, K.J.; Chenè, A.N.; Crowther, P.A.; Daminelli, A.; Gräfener, G.; Groh, J.H.; Hamann, W.R.; Heap, S.; Herrero, A.; Kaper, L.; Najarro, F.; Oskinova, L.M.; Roman-Lopes, A.; Rosen, A.; Sander, A.; Shirazi, M.; Sugawara, Y.; Tramper, F.; Vanbeveren, D.; Voss, R.; Wofford, A.; Zhang, Y.

    2015-01-01

    Recent studies have claimed the existence of very massive stars (VMS) up to 300 M⊙ in the local Universe. As this finding may represent a paradigm shift for the canonical stellar upper-mass limit of 150 M⊙, it is timely to discuss the status of the data, as well as the far-reaching implications of

  12. Massive rectal bleeding from colonic diverticulosis

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    Objectives: This is to describe a case of colonic diverticulosis causing massive rectal bleeding in an elderly Nigerian man. ... Colonoscopy identified multiple diverticula in the proximal rectum, sigmoid, descending and ... rectum proximal, sigmoïde, descendant et transversal diverticules colons. Les diverticulesétaient plus.

  13. A massive runaway star from 30 Doradus

    NARCIS (Netherlands)

    Evans, C.J.; Walborn, N.R.; Crowther, P.A.; Hénault-Brunet, V.; Massa, D.; Taylor, W.D.; Howarth, I.D.; Sana, H.; Lennon, D.J.; van Loon, J.T.

    2010-01-01

    We present the first ultraviolet (UV) and multi-epoch optical spectroscopy of 30 Dor 016, a massive O2-type star on the periphery of 30 Doradus in the Large Magellanic Cloud. The UV data were obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope as part of the Servicing Mission

  14. Massive Cervico-Lingual Cystic Hygroma

    African Journals Online (AJOL)

    Cystic Hygroma (CH) is an aberrant proliferation of lymphatic vessels creating fluid-filled sacs that result from blockage in the abnormal lymphatic system. These benign lesions are characteristic in their capability to grow to an enormously huge size has potential pressure effects on the neighboring structures. The massive ...

  15. Massive Skyrmions in quantum Hall ferromagnets

    NARCIS (Netherlands)

    Abolfath, M.; Mullen, K.; Stoof, H.T.C.

    2001-01-01

    We apply the theory of elasticity to study the effects of Skyrmion mass on lattice dynamics in quantum Hall systems. We find that massive Skyrme lattices behave like a Wigner crystal in the presence of a uniform perpendicular magnetic field. We make a comparison with the microscopic Hartree-Fock

  16. Holographic Josephson junction from massive gravity

    NARCIS (Netherlands)

    Hu, Ya-Peng; Li, Huai-Fan; Zeng, Hua-Bi; Zhang, H.

    2016-01-01

    We study the holographic superconductor-normal metal-superconductor (SNS) Josephson junction in de Rham-Gabadadze-Tolley massive gravity. If the boundary theory is independent of spatial directions, i.e., if the chemical potential is homogeneous in spatial directions, we find that the graviton mass

  17. Severe falciparum malaria associated with massive pulmonary ...

    African Journals Online (AJOL)

    Microthrombotic complications are the best described; however, a number of cases of thrombosis involving larger vessels have been published in the literature. Herein, we describe the case of a woman with malaria associated with massive pulmonary embolism. Keywords: Falciparum, malaria, pulmonary embolism ...

  18. Massive Spontaneous Hemothorax, Giant Intrathoracic Meningocele ...

    African Journals Online (AJOL)

    Massive Spontaneous Hemothorax, Giant Intrathoracic. Meningocele, and Kyphoscoliosis in Neurofibromatosis Type 1. Ayodeji Salman Yusuf, Ashok Pillai1, Sajesh K. Menon1, Dilip Panikar1. INTRODUCTION. Neurofibromatosis type 1 (NF‑1) is an autosomal dominant disease with an incidence ranging from. 1 in 2500 to ...

  19. The extraordinary structural evolution of massive galaxies

    NARCIS (Netherlands)

    Szomoru, Daniel

    2013-01-01

    Galaxies have changed drastically over the past 10 billion years. This thesis deals with these changes, focusing on evolution in the structure of very massive galaxies with a range of stellar population properties. The main subjects addressed are the rapid changes in the sizes of old galaxies, the

  20. Management of massive haemoptysis | Adegboye | Nigerian Journal ...

    African Journals Online (AJOL)

    Nigerian Journal of Surgical Research ... Results: Both groups have comparative age and sex distribution and infective pulmonary diseases dominated as causes of massive haemoptysis. ... The number of pneumonectomies were 12 out of 18 procedures (66.7%) for group I and 19 out of 68 procedures (27.9%) in group II.

  1. Massive exophytic malignant peripheral nerve sheath tumor

    Directory of Open Access Journals (Sweden)

    Derek Khorsand, MD

    2016-06-01

    Full Text Available We present a case of a solitary neurofibroma involving the right posterior shoulder of a 69-year-old man with degeneration into a massive, malignant peripheral nerve sheath tumor measuring more than 3 times the average reported size. The radiographic, magnetic resonance imaging, and computed tomographic features are compared with the gross appearance and pathology.

  2. Massive Ascites Complicating Pre-eclampsia

    Directory of Open Access Journals (Sweden)

    Ma-Lee Ko

    2005-09-01

    Conclusion: Clinicians should be aware of the possible presence of ascites in patients with severe pre-eclampsia. If the hypertension is controlled and the fetus is healthy, abdominal paracentesis without pregnancy termination is an efficacious procedure for the management of massive ascites complicating severe pre-eclampsia.

  3. Massive Spontaneous Hemothorax, Giant Intrathoracic Meningocele ...

    African Journals Online (AJOL)

    Neurofibromatosis type 1 (NF‑1) is a heterogeneous autosomal dominant disease with an incidence ranging from 1 in 2500 to 1 in 3000. Rare intrathoracic vascular disorders resulting in massive spontaneous hemothorax with fatal consequences may occur in these patients, so also are various types of skeletal dysplasia ...

  4. Topical perspective on massive threading and parallelism.

    Science.gov (United States)

    Farber, Robert M

    2011-09-01

    Unquestionably computer architectures have undergone a recent and noteworthy paradigm shift that now delivers multi- and many-core systems with tens to many thousands of concurrent hardware processing elements per workstation or supercomputer node. GPGPU (General Purpose Graphics Processor Unit) technology in particular has attracted significant attention as new software development capabilities, namely CUDA (Compute Unified Device Architecture) and OpenCL™, have made it possible for students as well as small and large research organizations to achieve excellent speedup for many applications over more conventional computing architectures. The current scientific literature reflects this shift with numerous examples of GPGPU applications that have achieved one, two, and in some special cases, three-orders of magnitude increased computational performance through the use of massive threading to exploit parallelism. Multi-core architectures are also evolving quickly to exploit both massive-threading and massive-parallelism such as the 1.3 million threads Blue Waters supercomputer. The challenge confronting scientists in planning future experimental and theoretical research efforts--be they individual efforts with one computer or collaborative efforts proposing to use the largest supercomputers in the world is how to capitalize on these new massively threaded computational architectures--especially as not all computational problems will scale to massive parallelism. In particular, the costs associated with restructuring software (and potentially redesigning algorithms) to exploit the parallelism of these multi- and many-threaded machines must be considered along with application scalability and lifespan. This perspective is an overview of the current state of threading and parallelize with some insight into the future. Published by Elsevier Inc.

  5. Ore horizons, ore facies, mineralogy and geochemistry of volconogenic massive sulfide (VMS deposits of the Varandan Ba-Pb-Cu deposit, southwest of Qamsar - Iran

    Directory of Open Access Journals (Sweden)

    Fayeq Hashemi

    2017-11-01

    research funding of Iranian Mines and Mining Industries Development and Renovation Organization (IMIDRO and the University of Shahrood. References Farokhpey, H., Shamsi-Poor, R. and Nasre-Esfahani, A. 2010. Economic petrology of granitoid Ghazaan: study of metal deposit. The Conference on Applied Petrology, Khorasgan Azad university, Tehran, Iran. Hoy, T., 1995. Noranda/kuroko Massive Sulphide Cu-Zn deposits. In: D.V. Lefebure and G.E. Ray (Editors, Selected British Colombia Mineral deposit Profiles, volum 1- Metallics and Coal. British Columbia Ministry of Energy of Employment and Investment open file, Canada, pp. 53-54. Huston, D., Relvas, J., Gemmell, J.B. and Drieberg, S., 2011. The role of granites in volcanic-hosted massive sulphide ore-forming systems: an assessment of magmatic-hydrothermal contributions.Journal of Mineralium Deposita, 46(5-6: 473-507. Izadi, H., 1996. Geology, petrografy and genises of Ba-Pb Kashan Ghamsar Ghazaan. M.Sc. thesis, Khorasgan Azad university, Tehran, Iran. 160 pp. Khalajmaasomi, M., Lotfi, M. and Nazari, M., 2010. Tapeh-Sorkh Mine mineralization model designation Bijegan-Delijan Central Province. Journal of Land and Resources, 1(2: 33-43. (in Persian Nazari, M., 1994. Study of mineralogy and ore genesis Dorreh deposit in the Kashan. M.Sc. Thesis, Tarbiat-moallem University, Tehran, Iran, 147 pp. (in Persian with English abstract Ohmoto, H. and Skinner, B.L., 1983. The Kuroko and related volcanogenic massive sulphide deposits: Introduction and summary of new findings. In: H. Ohmoto and B.J. Skinner (Editors, Kuroko and Related Volcanogenic Massive Sulphide Deposits. Economic Geology, Canada, pp. 1-8.

  6. Magnetic fields and wind variability in massive stars

    NARCIS (Netherlands)

    Schnerr, R.S.; Henrichs, H.F.; Hamann, W.-R.; Feldmeier, A.; Oskinova, L.

    2008-01-01

    This paper describes the thesis work of Schnerr (2007) entitled "Magnetic fields and mass loss in massive stars", which aimed at a better understanding of the impact of magnetic fields on the winds of massive stars.

  7. M2M massive wireless access

    DEFF Research Database (Denmark)

    Zanella, Andrea; Zorzi, Michele; Santos, André F.

    2013-01-01

    In order to make the Internet of Things a reality, ubiquitous coverage and low-complexity connectivity are required. Cellular networks are hence the most straightforward and realistic solution to enable a massive deployment of always connected Machines around the globe. Nevertheless, a paradigm...... shift in the conception and design of future cellular networks is called for. Massive access attempts, low-complexity and cheap machines, sporadic transmission and correlated signals are among the main properties of this new reality, whose main consequence is the disruption of the development...... Access Reservation, Coded Random Access and the exploitation of multiuser detection in random access. Additionally, we will show how the properties of machine originated signals, such as sparsity and spatial/time correlation can be exploited. The end goal of this paper is to provide motivation...

  8. Very Massive Stars in the Local Universe

    Science.gov (United States)

    Smith, Linda

    2017-08-01

    The upper mass limit for stars is unknown. Recent UV observations of young (5 x10^4 M_sun) suggest that stars substantially more massive than 100 M_sun exist. These very massive stars (VMS) are not properly accounted for in current stellar population synthesis (SPS) codes, even though they will dominate the ionization and mechanical feedback in star-forming regions for the first few Myr. VMS have been detected as resolved stars in the nearby LMC cluster R136 and in the integrated light of two young super star clusters in two nearby starburst galaxies. Since JWST will obtain numerous UV rest-frame spectra of young high redshift galaxies, it is essential that we investigate whether VMS are common in local, low metallicity analogs, while we still have access to the UV domain. We propose to obtain FUV STIS spectroscopy of young (frame UV spectra of high-z galaxies to be obtained with JWST.

  9. Massive Predictive Modeling using Oracle R Enterprise

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    R is fast becoming the lingua franca for analyzing data via statistics, visualization, and predictive analytics. For enterprise-scale data, R users have three main concerns: scalability, performance, and production deployment. Oracle's R-based technologies - Oracle R Distribution, Oracle R Enterprise, Oracle R Connector for Hadoop, and the R package ROracle - address these concerns. In this talk, we introduce Oracle's R technologies, highlighting how each enables R users to achieve scalability and performance while making production deployment of R results a natural outcome of the data analyst/scientist efforts. The focus then turns to Oracle R Enterprise with code examples using the transparency layer and embedded R execution, targeting massive predictive modeling. One goal behind massive predictive modeling is to build models per entity, such as customers, zip codes, simulations, in an effort to understand behavior and tailor predictions at the entity level. Predictions...

  10. Adapting algorithms to massively parallel hardware

    CERN Document Server

    Sioulas, Panagiotis

    2016-01-01

    In the recent years, the trend in computing has shifted from delivering processors with faster clock speeds to increasing the number of cores per processor. This marks a paradigm shift towards parallel programming in which applications are programmed to exploit the power provided by multi-cores. Usually there is gain in terms of the time-to-solution and the memory footprint. Specifically, this trend has sparked an interest towards massively parallel systems that can provide a large number of processors, and possibly computing nodes, as in the GPUs and MPPAs (Massively Parallel Processor Arrays). In this project, the focus was on two distinct computing problems: k-d tree searches and track seeding cellular automata. The goal was to adapt the algorithms to parallel systems and evaluate their performance in different cases.

  11. How Massive Single Stars End Their Life

    Science.gov (United States)

    Heger, A.; Fryer, C. L.; Woosley, S. E.; Langer, N.; Hartmann, D. H.

    2003-01-01

    How massive stars die-what sort of explosion and remnant each produces-depends chiefly on the masses of their helium cores and hydrogen envelopes at death. For single stars, stellar winds are the only means of mass loss, and these are a function of the metallicity of the star. We discuss how metallicity, and a simplified prescription for its effect on mass loss, affects the evolution and final fate of massive stars. We map, as a function of mass and metallicity, where black holes and neutron stars are likely to form and where different types of supernovae are produced. Integrating over an initial mass function, we derive the relative populations as a function of metallicity. Provided that single stars rotate rapidly enough at death, we speculate on stellar populations that might produce gamma-ray bursts and jet-driven supernovae.

  12. Massively Parallel Computing: A Sandia Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Dosanjh, Sudip S.; Greenberg, David S.; Hendrickson, Bruce; Heroux, Michael A.; Plimpton, Steve J.; Tomkins, James L.; Womble, David E.

    1999-05-06

    The computing power available to scientists and engineers has increased dramatically in the past decade, due in part to progress in making massively parallel computing practical and available. The expectation for these machines has been great. The reality is that progress has been slower than expected. Nevertheless, massively parallel computing is beginning to realize its potential for enabling significant break-throughs in science and engineering. This paper provides a perspective on the state of the field, colored by the authors' experiences using large scale parallel machines at Sandia National Laboratories. We address trends in hardware, system software and algorithms, and we also offer our view of the forces shaping the parallel computing industry.

  13. Zinc toxicity following massive coin ingestion.

    Science.gov (United States)

    Bennett, D R; Baird, C J; Chan, K M; Crookes, P F; Bremner, C G; Gottlieb, M M; Naritoku, W Y

    1997-06-01

    This is the first reported case of human fatality associated with zinc intoxication following a massive ingestion of coins. Four hundred and sixty-one coins were removed form the gastrointestinal tract of a schizophrenic patient during the course of hospitalization. Many of the post-1981 pennies, which consist primarily of zinc, showed severe corrosion due to their prolonged contact with acidic gastric juice. The patient presented with clinical manifestations consistent with the local corrosive as well as systemic effects of zinc intoxication and died 40 days after admission with multi-system organ failure. Tissue samples of the kidneys, pancreas, and liver obtained at autopsy revealed acute tubular necrosis, mild fibrosis, and acute massive necrosis, respectively, and contained high levels of zinc. The overall effects of zinc intoxication on the various organ systems, possible hematological derangement, and the impairment of copper absorption as well as the outcome with treatment are discussed.

  14. Very massive stars in the local universe

    CERN Document Server

    2015-01-01

    This book presents the status of research on very massive stars in the Universe. While it has been claimed that stars with over 100 solar masses existed in the very early Universe, recent studies have also discussed the existence and deaths of stars up to 300 solar masses in the local Universe. This represents a paradigm shift for the stellar upper-mass limit, which may have major implications far beyond the field of stellar physics. The book comprises 7 chapters, which describe this discipline and provide sufficient background and introductory content for graduate (PhD) students and researchers from different branches of astronomy to be able to enter this exciting new field of very massive stars.

  15. Spontaneous Resolution of Massive Spontaneous Tubercular Pneumothorax

    Science.gov (United States)

    Kant, Surya; Saheer, S.; Hassan, G.; Parengal, Jabeed

    2011-01-01

    A 29-year-old female presented with complaints of fever and productive cough of three weeks duration. Pulmonary tuberculosis was diagnosed bacteriologically and she was prescribed antituberculosis drugs. During follow-up she developed massive pneumothorax, for which patient refused surgical management and was managed conservatively. After six months there was complete spontaneous resolution of pneumothorax. The unusual presentation and unexpected outcome prompted us to report this case. PMID:22937428

  16. Peer Ratings in Massive Online Social Networks

    OpenAIRE

    Zinoviev, Dmitry

    2014-01-01

    Instant quality feedback in the form of online peer ratings is a prominent feature of modern massive online social networks (MOSNs). It allows network members to indicate their appreciation of a post, comment, photograph, etc. Some MOSNs support both positive and negative (signed) ratings. In this study, we rated 11 thousand MOSN member profiles and collected user responses to the ratings. MOSN users are very sensitive to peer ratings: 33% of the subjects visited the researcher's profile in r...

  17. Massively parallel evolutionary computation on GPGPUs

    CERN Document Server

    Tsutsui, Shigeyoshi

    2013-01-01

    Evolutionary algorithms (EAs) are metaheuristics that learn from natural collective behavior and are applied to solve optimization problems in domains such as scheduling, engineering, bioinformatics, and finance. Such applications demand acceptable solutions with high-speed execution using finite computational resources. Therefore, there have been many attempts to develop platforms for running parallel EAs using multicore machines, massively parallel cluster machines, or grid computing environments. Recent advances in general-purpose computing on graphics processing units (GPGPU) have opened u

  18. Phenomenology in minimal theory of massive gravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji

    2016-04-01

    We investigate the minimal theory of massive gravity (MTMG) recently introduced. After reviewing the original construction based on its Hamiltonian in the vielbein formalism, we reformulate it in terms of its Lagrangian in both the vielbein and the metric formalisms. It then becomes obvious that, unlike previous attempts in the literature of Lorentz-violating massive gravity, not only the potential but also the kinetic structure of the action is modified from the de Rham-Gabadadze-Tolley (dRGT) massive gravity theory. We confirm that the number of physical degrees of freedom in MTMG is two at fully nonlinear level. This proves the absence of various possible pathologies such as superluminality, acausality and strong coupling. Afterwards, we discuss the phenomenology of MTMG in the presence of a dust fluid. We find that on a flat homogeneous and isotropic background we have two branches. One of them (self-accelerating branch) naturally leads to acceleration without the genuine cosmological constant or dark energy. For this branch both the scalar and the vector modes behave exactly as in general relativity (GR). The phenomenology of this branch differs from GR in the tensor modes sector, as the tensor modes acquire a non-zero mass. Hence, MTMG serves as a stable nonlinear completion of the self-accelerating cosmological solution found originally in dRGT theory. The other branch (normal branch) has a dynamics which depends on the time-dependent fiducial metric. For the normal branch, the scalar mode sector, even though as in GR only one scalar mode is present (due to the dust fluid), differs from the one in GR, and, in general, structure formation will follow a different phenomenology. The tensor modes will be massive, whereas the vector modes, for both branches, will have the same phenomenology as in GR.

  19. Magnetic fields and massive star formation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qizhou; Keto, Eric; Ho, Paul T. P.; Ching, Tao-Chung; Chen, How-Huan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Qiu, Keping [School of Astronomy and Space Science, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Girart, Josep M.; Juárez, Carmen [Institut de Ciències de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciències, C5p 2, E-08193 Bellaterra, Catalonia (Spain); Liu, Hauyu; Tang, Ya-Wen; Koch, Patrick M.; Rao, Ramprasad; Lai, Shih-Ping [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China); Li, Zhi-Yun [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Frau, Pau [Observatorio Astronómico Nacional, Alfonso XII, 3 E-28014 Madrid (Spain); Li, Hua-Bai [Department of Physics, The Chinese University of Hong Kong, Hong Kong (China); Padovani, Marco [Laboratoire de Radioastronomie Millimétrique, UMR 8112 du CNRS, École Normale Supérieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Bontemps, Sylvain [OASU/LAB-UMR5804, CNRS, Université Bordeaux 1, F-33270 Floirac (France); Csengeri, Timea, E-mail: qzhang@cfa.harvard.edu [Max Planck Institute for Radioastronomy, Auf dem Hügel 69, D-53121 Bonn (Germany)

    2014-09-10

    Massive stars (M > 8 M {sub ☉}) typically form in parsec-scale molecular clumps that collapse and fragment, leading to the birth of a cluster of stellar objects. We investigate the role of magnetic fields in this process through dust polarization at 870 μm obtained with the Submillimeter Array (SMA). The SMA observations reveal polarization at scales of ≲0.1 pc. The polarization pattern in these objects ranges from ordered hour-glass configurations to more chaotic distributions. By comparing the SMA data with the single dish data at parsec scales, we found that magnetic fields at dense core scales are either aligned within 40° of or perpendicular to the parsec-scale magnetic fields. This finding indicates that magnetic fields play an important role during the collapse and fragmentation of massive molecular clumps and the formation of dense cores. We further compare magnetic fields in dense cores with the major axis of molecular outflows. Despite a limited number of outflows, we found that the outflow axis appears to be randomly oriented with respect to the magnetic field in the core. This result suggests that at the scale of accretion disks (≲ 10{sup 3} AU), angular momentum and dynamic interactions possibly due to close binary or multiple systems dominate over magnetic fields. With this unprecedentedly large sample of massive clumps, we argue on a statistical basis that magnetic fields play an important role during the formation of dense cores at spatial scales of 0.01-0.1 pc in the context of massive star and cluster star formation.

  20. Theoretical Developments in Understanding Massive Star Formation

    Science.gov (United States)

    Yorke, Harold W.; Bodenheimer, Peter

    2007-01-01

    Except under special circumstances massive stars in galactic disks will form through accretion. The gravitational collapse of a molecular cloud core will initially produce one or more low mass quasi-hydrostatic objects of a few Jupiter masses. Through subsequent accretion the masses of these cores grow as they simultaneously evolve toward hydrogen burning central densities and temperatures. We review the evolution of accreting (proto-)stars, including new results calculated with a publicly available stellar evolution code written by the authors.

  1. Antenna Splitting Functions for Massive Particles

    Energy Technology Data Exchange (ETDEWEB)

    Larkoski, Andrew J.; Peskin, Michael E.; /SLAC

    2011-06-22

    An antenna shower is a parton shower in which the basic move is a color-coherent 2 {yields} 3 parton splitting process. In this paper, we give compact forms for the spin-dependent antenna splitting functions involving massive partons of spin 0 and spin 1/2. We hope that this formalism we have presented will be useful in describing the QCD dynamics of the top quark and other heavy particles at LHC.

  2. Surgical Treatment of Acute Massive Pulmonary Embolism.

    Science.gov (United States)

    Beckerman, Ziv; Bolotin, Gil

    2017-01-01

    Massive pulmonary embolism (MPE) is a life-threatening condition. The management of MPE has changed over the course of the last few years. Since the emergence of thrombolytic therapy, only a few patients remain amenable for surgical treatment. Currently, surgical embolectomy is advised only in very specific indications. This chapter will review the background, history, indications, surgical technique and results of surgical pulmonary embolectomy in patients with MPE.

  3. Massive Multi-Agent Systems Control

    Science.gov (United States)

    Campagne, Jean-Charles; Gardon, Alain; Collomb, Etienne; Nishida, Toyoaki

    2004-01-01

    In order to build massive multi-agent systems, considered as complex and dynamic systems, one needs a method to analyze and control the system. We suggest an approach using morphology to represent and control the state of large organizations composed of a great number of light software agents. Morphology is understood as representing the state of the multi-agent system as shapes in an abstract geometrical space, this notion is close to the notion of phase space in physics.

  4. Massive Schwinger model at finite θ

    Science.gov (United States)

    Azcoiti, Vicente; Follana, Eduardo; Royo-Amondarain, Eduardo; Di Carlo, Giuseppe; Vaquero Avilés-Casco, Alejandro

    2018-01-01

    Using the approach developed by V. Azcoiti et al. [Phys. Lett. B 563, 117 (2003), 10.1016/S0370-2693(03)00601-4], we are able to reconstruct the behavior of the massive one-flavor Schwinger model with a θ term and a quantized topological charge. We calculate the full dependence of the order parameter with θ . Our results at θ =π are compatible with Coleman's conjecture on the phase diagram of this model.

  5. Massive Multiplayer Online Games im mobilen Kontext

    OpenAIRE

    Fritsch, Tobias

    2010-01-01

    Within the last few years, the importance of (multiplayer) computer games has experienced immense growth. On par with that, the size of persistent virtual environments (VEs) has also increased. Today, more than 120 MMOGs (Massive Multiplayer Online Games) ranging from FPS (first person shooter) to classic RPG (role playing game) settings exist. This illustrates the significant influence of the growing number of simultaneously playing users. The way that games are played has also evolved. N...

  6. Massively parallelizing the RRT and the RRT*

    OpenAIRE

    Karaman, Sertac; Frazzoli, Emilio; Bialkowski, Joshua John

    2011-01-01

    In recent years, the growth of the computational power available in the Central Processing Units (CPUs) of consumer computers has tapered significantly. At the same time, growth in the computational power available in the Graphics Processing Units (GPUs) has remained strong. Algorithms that can be implemented on GPUs today are not only limited to graphics processing, but include scientific computation and beyond. This paper is concerned with massively parallel implementations of incremental s...

  7. Massive graph visualization : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Brian Neil; Moreland, Kenneth D.

    2007-10-01

    Graphs are a vital way of organizing data with complex correlations. A good visualization of a graph can fundamentally change human understanding of the data. Consequently, there is a rich body of work on graph visualization. Although there are many techniques that are effective on small to medium sized graphs (tens of thousands of nodes), there is a void in the research for visualizing massive graphs containing millions of nodes. Sandia is one of the few entities in the world that has the means and motivation to handle data on such a massive scale. For example, homeland security generates graphs from prolific media sources such as television, telephone, and the Internet. The purpose of this project is to provide the groundwork for visualizing such massive graphs. The research provides for two major feature gaps: a parallel, interactive visualization framework and scalable algorithms to make the framework usable to a practical application. Both the frameworks and algorithms are designed to run on distributed parallel computers, which are already available at Sandia. Some features are integrated into the ThreatView{trademark} application and future work will integrate further parallel algorithms.

  8. Massive transfusion protocols: current best practice

    Directory of Open Access Journals (Sweden)

    Hsu YM

    2016-03-01

    Full Text Available Yen-Michael S Hsu,1 Thorsten Haas,2 Melissa M Cushing1 1Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA; 2Department of Anesthesia, University Children's Hospital Zurich, Zurich, Switzerland Abstract: Massive transfusion protocols (MTPs are established to provide rapid blood replacement in a setting of severe hemorrhage. Early optimal blood transfusion is essential to sustain organ perfusion and oxygenation. There are many variables to consider when establishing an MTP, and studies have prospectively evaluated different scenarios and patient populations to establish the best practices to attain improved patient outcomes. The establishment and utilization of an optimal MTP is challenging given the ever-changing patient status during resuscitation efforts. Much of the MTP literature comes from the trauma population, due to the fact that massive hemorrhage is the leading cause of preventable trauma-related death. As we come to further understand the positive and negative clinical impacts of transfusion-related factors, massive transfusion practice can be further refined. This article will first discuss specific MTPs targeting different patient populations and current relevant international guidelines. Then, we will examine a wide selection of therapeutic products to support MTPs, including newly available products and the most suitable of the traditional products. Lastly, we will discuss the best design for an MTP, including ratio-based MTPs and MTPs based on the use of point-of-care coagulation diagnostic tools. Keywords: hemorrhage, MTP, antifibrinolytics, coagulopathy, trauma, ratio, logistics, guidelines, hemostatic

  9. On the generalized minimal massive gravity

    Directory of Open Access Journals (Sweden)

    M.R. Setare

    2015-09-01

    Full Text Available In this paper we study the Generalized Minimal Massive Gravity (GMMG in asymptotically AdS3 background. The generalized minimal massive gravity theory is realized by adding the CS deformation term, the higher derivative deformation term, and an extra term to pure Einstein gravity with a negative cosmological constant. We study the linearized excitations around the AdS3 background and find that at special point (tricritical in parameter space the two massive graviton solutions become massless and they are replaced by two solutions with logarithmic and logarithmic-squared boundary behavior. So it is natural to propose that GMMG model could also provide a holographic description for a 3-rank Logarithmic Conformal Field Theory (LCFT. We calculate the energy of the linearized gravitons in AdS3 background, and show that the theory is free of negative-energy bulk modes. Then we obtain the central charges of the CFT dual explicitly and show GMMG also avoids the aforementioned “bulk-boundary unitarity clash”. After that we show that General Zwei–Dreibein Gravity (GZDG model can reduce to GMMG model. Finally by a Hamiltonian analysis we show that the GMMG model has no Boulware–Deser ghosts and this model propagates only two physical modes.

  10. Emergent universe with wormholes in massive gravity

    Science.gov (United States)

    Paul, B. C.; Majumdar, A. S.

    2018-03-01

    An emergent universe (EU) scenario is proposed to obtain a universe free from big-bang singularity. In this framework the present universe emerged from a static Einstein universe phase in the infinite past. A flat EU scenario is found to exist in Einstein’s gravity with a non-linear equation of state (EoS). It has been shown subsequently that a physically realistic EU model can be obtained considering cosmic fluid composed of interacting fluids with a non-linear equation of state. It results a viable cosmological model accommodating both early inflation and present accelerating phases. In the present paper, the origin of an initial static Einstein universe needed in the EU model is explored in a massive gravity theory which subsequently emerged to be a dynamically evolving universe. A new gravitational instanton solution in a flat universe is obtained in the massive gravity theory which is a dynamical wormhole that might play an important role in realizing the origin of the initial state of the emergent universe. The emergence of a Lorentzian universe from a Euclidean gravity is understood by a Wick rotation τ = i t . A universe with radiation at the beginning finally transits into the present observed universe with a non-linear EoS as the interactions among the fluids set in. Thus a viable flat EU scenario where the universe stretches back into time infinitely, with no big bang is permitted in a massive gravity.

  11. Minimal theory of quasidilaton massive gravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele

    2017-07-01

    We introduce a quasidilaton scalar field to the minimal theory of massive gravity with the Minkowski fiducial metric, in such a way that the quasidilaton global symmetry is maintained and that the theory admits a stable self-accelerating de Sitter solution. We start with a precursor theory that contains three propagating gravitational degrees of freedom without a quasidilaton scalar and introduce Stückelberg fields to covariantize its action. This makes it possible for us to formulate the quasidilaton global symmetry that mixes the Stückelberg fields and the quasidilaton scalar field. By the Hamiltonian analysis we confirm that the precursor theory with the quasidilaton scalar contains 4 degrees of freedom, three from the precursor massive gravity and one from the quasidilaton scalar. We further remove one propagating degree of freedom to construct the minimal quasidilaton theory with three propagating degrees of freedom, corresponding to two polarizations of gravitational waves from the minimal theory of massive gravity and one scalar from the quasidilaton field, by carefully introducing two additional constraints to the system in the Hamiltonian language. Switching to the Lagrangian language, we find self-accelerating de Sitter solutions in the minimal quasidilaton theory and analyze their stability. It is found that the self-accelerating de Sitter solution is stable in a wide range of parameters.

  12. Current management of massive hemorrhage in trauma

    Directory of Open Access Journals (Sweden)

    Johansson Pär I

    2012-07-01

    Full Text Available Abstract Hemorrhage remains a major cause of potentially preventable deaths. Trauma and massive transfusion are associated with coagulopathy secondary to tissue injury, hypoperfusion, dilution, and consumption of clotting factors and platelets. Concepts of damage control surgery have evolved prioritizing early control of the cause of bleeding by non-definitive means, while hemostatic control resuscitation seeks early control of coagulopathy. Hemostatic resuscitation provides transfusions with plasma and platelets in addition to red blood cells in an immediate and sustained manner as part of the transfusion protocol for massively bleeding patients. Although early and effective reversal of coagulopathy is documented, the most effective means of preventing coagulopathy of massive transfusion remains debated and randomized controlled studies are lacking. Viscoelastical whole blood assays, like TEG and ROTEM however appear advantageous for identifying coagulopathy in patients with severe hemorrhage as opposed the conventional coagulation assays. In our view, patients with uncontrolled bleeding, regardless of it´s cause, should be treated with hemostatic control resuscitation involving early administration of plasma and platelets and earliest possible goal-directed, based on the results of TEG/ROTEM analysis. The aim of the goal-directed therapy should be to maintain a normal hemostatic competence until surgical hemostasis is achieved, as this appears to be associated with reduced mortality.

  13. On the Formation of Massive Stars

    Science.gov (United States)

    Yorke, Harold W.; Sonnhalter, Cordula

    2002-01-01

    We calculate numerically the collapse of slowly rotating, nonmagnetic, massive molecular clumps of masses 30,60, and 120 Stellar Mass, which conceivably could lead to the formation of massive stars. Because radiative acceleration on dust grains plays a critical role in the clump's dynamical evolution, we have improved the module for continuum radiation transfer in an existing two-dimensional (axial symmetry assumed) radiation hydrodynamic code. In particular, rather than using "gray" dust opacities and "gray" radiation transfer, we calculate the dust's wavelength-dependent absorption and emission simultaneously with the radiation density at each wavelength and the equilibrium temperatures of three grain components: amorphous carbon particles. silicates, and " dirty ice " -coated silicates. Because our simulations cannot spatially resolve the innermost regions of the molecular clump, however, we cannot distinguish between the formation of a dense central cluster or a single massive object. Furthermore, we cannot exclude significant mass loss from the central object(s) that may interact with the inflow into the central grid cell. Thus, with our basic assumption that all material in the innermost grid cell accretes onto a single object. we are able to provide only an upper limit to the mass of stars that could possibly be formed. We introduce a semianalytical scheme for augmenting existing evolutionary tracks of pre-main-sequence protostars by including the effects of accretion. By considering an open outermost boundary, an arbitrary amount of material could, in principal, be accreted onto this central star. However, for the three cases considered (30, 60, and 120 Stellar Mass originally within the computation grid), radiation acceleration limited the final masses to 3 1.6, 33.6, and 42.9 Stellar Mass, respectively, for wavelength-dependent radiation transfer and to 19.1, 20.1, and 22.9 Stellar Mass. for the corresponding simulations with gray radiation transfer. Our

  14. Molecular Outflows in Massive Star Forming Regions

    Science.gov (United States)

    Cunningham, Nichol

    2015-11-01

    This thesis presents millimetre continuum and molecular line observations exploring the properties of molecular outflows towards massive star forming regions. Massive stars produce some of the most energetic phenomena in the Galaxy, yet we still do not have a comprehensive understanding of how they actually form. Outflows are known to play a key role in this formation process and their properties, particularly how they change depending on the mass, luminosity and evolution of the driving source can shed light on how massive stars actually form. This thesis presents observations at both high (SMA 3 arcsecond) and low (JCMT 15 arcsecond) spatial resolution of the known jet/outflow tracers, SiO and 12CO, towards a sample massive star forming region drawn from the RMS survey. Furthermore, the presence of infall signatures is explored through observations of HCO+ and H13CO+, and the hot core nature of the regions is probed using tracers such as CH3CN, HC3N and CH3OH. SiO is detected towards approximately 50% of the massive young stellar objects and HII regions in the JCMT sample. The detection of SiO appears to be linked to the age of the RMS source, with the likely younger sources showing a stronger dependence with SiO. The presence of SiO also appears to be linked to the CO velocity, with SiO more efficiently tracing sources with higher velocity dispersions. In the MOPRA observations towards a sample of 33 RMS sources, CH3CN is detected towards 66% of the sources, with the redder likely younger sources having the largest rotational temperatures. This thesis presents the first interferometric SiO (5-4) and 12CO (2-1) observations, taken with the SMA, towards the massive star forming region G203.3166/NGC 2264-C. In this intermediate/massive star forming cluster, SiO is again tracing the youngest sources. Both the SiO and 12CO emission trace two bipolar, high velocity outflows towards the mm brightest, IR-dark, likely youngest sources in this reg! ion. In contrast the IR

  15. Lithogeochemical, mineralogical analyses and oxygen-hydrogen isotopes of the Hercynian Koudiat Aïcha massive sulphide deposit, Morocco

    Science.gov (United States)

    Lotfi, F.; Belkabir, A.; Brunet, S.; Brown, A. C.; Marcoux, E.

    2010-03-01

    Koudiat Aïcha is a Visean stratiform, volcanogenic massive sulphide (VMS) zinc-copper-lead deposit, situated northwest of Marrakech, within the Central Domain of the Jebilet massif of the Western Moroccan Meseta. The Central Domain is formed mainly of sedimentary (argillite, siltstone, sandstone, carbonate) and magmatic (gabbro and rhyodacite) rocks that host numerous massive sulphide deposits (e.g., Koudiat Aïcha, Kettara and Draa Sfar) in a thick grayish argillite sequence (rhythmic metapelite). The deposit is stratabound and consists of highly deformed, sheet-like lenses of massive sulphide located structurally on the eastern flank of a large anticline. Prior to metamorphism, the country rocks were subjected to hydrothermal alteration which is particularly pronounced in the immediate vicinity of the sulphide deposits where chloritization and sericitization are prevalent. Hydrothermal alteration extends into both the stratigraphic footwall and the stratigraphic hanging wall. The footwall lacks an obvious pipe zone (sulphide stringers or vent complex) beneath the sulphide mineralization, but is characterized by an increase in the modal proportion of Mg-chlorite and by the breakdown of feldspar and sericite. Chloritization, the most extensive and readily recognizable alteration useful in mineral exploration, is evident for more than 60 m above the subcropping sulphide deposits. The hanging wall rocks show a pervasive sericitization (over 30 m wide) and a weak chlorite alteration accompanied by disseminated nodules of pyrrhotite stretched parallel to the S 1 foliation. Because chlorite and sericite are metamorphic minerals that also occur in unaltered rocks surrounding the sulphide deposits, abundant Mg-rich chlorite and the absence of feldspar in the footwall are used to distinguish hydrothermal alteration facies from metamorphic facies. The chlorite geothermometer reveals temperatures between 250 and 330 °C. Higher temperatures (up to 300 °C) are associated

  16. Massively parallel implementation of character recognition systems

    Science.gov (United States)

    Garris, Michael D.; Wilson, Charles L.; Blue, James L.; Candela, Gerald T.; Grother, Patrick J.; Janet, Stanley A.; Wilkinson, R. A.

    1992-08-01

    A massively parallel character recognition system has been implemented. The system is designed to study the feasibility of the recognition of handprinted text in a loosely constrained environment. The NIST handprint database, NIST Special Database 1, is used to provide test data for the recognition system. The system consists of eight functional components. The loading of the image into the system and storing the recognition results from the system are I/O components. In between are components responsible for image processing and recognition. The first image processing component is responsible for image correction for scale and rotation, data field isolation, and character data location within each field; the second performs character segmentation; and the third does character normalization. Three recognition components are responsible for feature extraction and character reconstruction, neural network-based character recognition, and low-confidence classification rejection. The image processing to load and isolate 34 fields on a scientific workstation takes 900 seconds. The same processing takes only 11 seconds using a massively parallel array processor. The image processing components, including the time to load the image data, use 94 of the system time. The segmentation time is 15 ms/character and segmentation accuracy is 89 for handprinted digits and alphas. Character recognition accuracy for medium quality machine print is 99.8. On handprinted digits, the recognition accuracy is 96 and recognition speeds of 10,100 characters/second can be realized. The limiting factor in the recognition portion of the system is feature extraction, which occurs at 806 characters/second. Through the use of a massively parallel machine and neural recognition algorithms, significant improvements in both accuracy and speed have been achieved, making this technology effective as a replacement for key data entry in existing data capture systems.

  17. Molecular Outflows from Newly Formed Massive Stars

    Science.gov (United States)

    Kim, Kee-Tae; Kim, Won-Ju; Kim, Chang-Hee

    2015-12-01

    We map 6 massive young stellar objects (YSOs) in the CO J=2-1 line and survey 18 massive YSOs, including the six, in the hcopj, sioj, water 6_{16}-5_{23} maser, and methanol 7_{0}-6_{1} A^{+} maser lines. We detect CO bipolar outflows in all the six mapped sources. Four of them are newly discovered (ifive, ieight, inine, iten), while itwo is mapped in the CO J=2-1 line for the first time. The detected outflows are much more massive and energetic than outflows from low-mass YSOs with masses >20 M_⊙ and momenta >300 M_⊙ km/s. They have mass outflow rates (3-6)×10^{-4} M_⊙ yr^{-1}, which are at least one order of magnitude greater than those observed in low-mass YSOs. We detect hcop and SiO line emission in 18 (100%) and 4 (22%) sources, respectively. The hcop spectra show high-velocity wings in 11 (61%) sources. We detect water maser emission in 13 (72%) sources and 44 GHz methanol maser emission in 8 (44%) sources. Of the detected sources, 5 water and 6 methanol maser sources are new discoveries. iseven shows high-velocity (>30 kms) water maser lines. We find good correlations of the bolometric luminosity of the central (proto)star with the mechanical force, mechanical luminosity, and mass outflow rate of molecular outflow %L_{bol} with F_{m}, L_{m}, and dot{M}_{out} in the bolometric luminosity range of 10^{-1}-10^6 lsol, and identified 3 intermediate- or high-mass counterparts of Class O objects.

  18. Dressler Syndrome is Characterized by Massive Hemoptysis

    Directory of Open Access Journals (Sweden)

    Erkan Ceylan

    2016-01-01

    Full Text Available A 63-year-old man was admitted with signs of dyspnea, pleuritic chest pain, fever, leukocytosis, high sedimentation rate, increase on C-reactive protein level, pleural effusion 2 weeks after coronary artery bypass surgery. According to the clinic and laboratory findings, Dressler syndrome diagnosed by the exclusion of pulmonary embolism, pneumonia, congestive heart failure and coronary artery bypass surgery complications. Massive hemoptysis was thought to be a result of local inflammatory reaction triggered by the immune activation and pleura, pericardium and vascular structures.

  19. Massively parallel sequencing of forensic STRs

    DEFF Research Database (Denmark)

    Parson, Walther; Ballard, David; Budowle, Bruce

    2016-01-01

    The DNA Commission of the International Society for Forensic Genetics (ISFG) is reviewing factors that need to be considered ahead of the adoption by the forensic community of short tandem repeat (STR) genotyping by massively parallel sequencing (MPS) technologies. MPS produces sequence data...... accessible genome assembly, and in place before the uptake of MPS by the general forensic community starts to generate sequence data on a large scale. While the established nomenclature for CE-based STR analysis will remain unchanged in the future, the nomenclature of sequence-based STR genotypes will need...

  20. Analytic solutions in nonlinear massive gravity.

    Science.gov (United States)

    Koyama, Kazuya; Niz, Gustavo; Tasinato, Gianmassimo

    2011-09-23

    We study spherically symmetric solutions in a covariant massive gravity model, which is a candidate for a ghost-free nonlinear completion of the Fierz-Pauli theory. There is a branch of solutions that exhibits the Vainshtein mechanism, recovering general relativity below a Vainshtein radius given by (r(g)m(2))(1/3), where m is the graviton mass and r(g) is the Schwarzschild radius of a matter source. Another branch of exact solutions exists, corresponding to de Sitter-Schwarzschild spacetimes where the curvature scale of de Sitter space is proportional to the mass squared of the graviton.

  1. Massive juvenile angiomatosis of maxilla and mandible

    Directory of Open Access Journals (Sweden)

    Dinesh Singh Chauhan

    2014-01-01

    Full Text Available Angiomatosis is a complex vascular malformation of infancy and childhood consisting of proliferating blood vessels with accompanying mature fat, fibrous tissue, lymphatic′s and nerves, which may involve skin, subcutaneous tissue, skeletal muscle and occasionally bone. It is extremely rare and benign, but a clinically extensive vascular lesion of soft-tissue, which usually becomes symptomatic during childhood or adolescence. We report a rare case of massive juvenile angiomatosis of maxilla and mandible in a 15-year-old male patient.

  2. Massive phytoplankton blooms under Arctic sea ice.

    Science.gov (United States)

    Arrigo, Kevin R; Perovich, Donald K; Pickart, Robert S; Brown, Zachary W; van Dijken, Gert L; Lowry, Kate E; Mills, Matthew M; Palmer, Molly A; Balch, William M; Bahr, Frank; Bates, Nicholas R; Benitez-Nelson, Claudia; Bowler, Bruce; Brownlee, Emily; Ehn, Jens K; Frey, Karen E; Garley, Rebecca; Laney, Samuel R; Lubelczyk, Laura; Mathis, Jeremy; Matsuoka, Atsushi; Mitchell, B Greg; Moore, G W K; Ortega-Retuerta, Eva; Pal, Sharmila; Polashenski, Chris M; Reynolds, Rick A; Schieber, Brian; Sosik, Heidi M; Stephens, Michael; Swift, James H

    2012-06-15

    Phytoplankton blooms over Arctic Ocean continental shelves are thought to be restricted to waters free of sea ice. Here, we document a massive phytoplankton bloom beneath fully consolidated pack ice far from the ice edge in the Chukchi Sea, where light transmission has increased in recent decades because of thinning ice cover and proliferation of melt ponds. The bloom was characterized by high diatom biomass and rates of growth and primary production. Evidence suggests that under-ice phytoplankton blooms may be more widespread over nutrient-rich Arctic continental shelves and that satellite-based estimates of annual primary production in these waters may be underestimated by up to 10-fold.

  3. Detecting emotional contagion in massive social networks.

    Directory of Open Access Journals (Sweden)

    Lorenzo Coviello

    Full Text Available Happiness and other emotions spread between people in direct contact, but it is unclear whether massive online social networks also contribute to this spread. Here, we elaborate a novel method for measuring the contagion of emotional expression. With data from millions of Facebook users, we show that rainfall directly influences the emotional content of their status messages, and it also affects the status messages of friends in other cities who are not experiencing rainfall. For every one person affected directly, rainfall alters the emotional expression of about one to two other people, suggesting that online social networks may magnify the intensity of global emotional synchrony.

  4. Detecting emotional contagion in massive social networks.

    Science.gov (United States)

    Coviello, Lorenzo; Sohn, Yunkyu; Kramer, Adam D I; Marlow, Cameron; Franceschetti, Massimo; Christakis, Nicholas A; Fowler, James H

    2014-01-01

    Happiness and other emotions spread between people in direct contact, but it is unclear whether massive online social networks also contribute to this spread. Here, we elaborate a novel method for measuring the contagion of emotional expression. With data from millions of Facebook users, we show that rainfall directly influences the emotional content of their status messages, and it also affects the status messages of friends in other cities who are not experiencing rainfall. For every one person affected directly, rainfall alters the emotional expression of about one to two other people, suggesting that online social networks may magnify the intensity of global emotional synchrony.

  5. CSW rules for a massive scalar

    DEFF Research Database (Denmark)

    Boels, Rutger Herman; Schwinn, Christian

    2008-01-01

    We derive the analog of the Cachazo-Svrcek-Witten (CSW) diagrammatic Feynman rules for four-dimensional Yang-Mills gauge theory coupled to a massive colored scalar. The mass term is shown to give rise to a new tower of vertices in addition to the CSW vertices for massless scalars in non......-supersymmetric theories. The rules are derived directly from an action, once through a canonical transformation within light-cone Yang-Mills and once by the construction of a twistor action. The rules are tested against known results in several examples and are used to simplify the proof of on-shell recursion relations...

  6. Massive clot formation after tooth extraction

    Directory of Open Access Journals (Sweden)

    Santosh Hunasgi

    2015-01-01

    Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.

  7. Dipolar dark matter with massive bigravity

    Energy Technology Data Exchange (ETDEWEB)

    Blanchet, Luc [GRECO Institut d’Astrophysique de Paris - UMR 7095 du CNRS,Université Pierre & Marie Curie,98" b" i" s boulevard Arago, 75014 Paris (France); Heisenberg, Lavinia [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, 10691 Stockholm (Sweden); Department of Physics & The Oskar Klein Centre, AlbaNova University Centre,Roslagstullsbacken 21, 10691 Stockholm (Sweden)

    2015-12-14

    Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.

  8. Massive rotator cuff tears: definition and treatment.

    Science.gov (United States)

    Lädermann, Alexandre; Denard, Patrick J; Collin, Philippe

    2015-12-01

    The aim of this review is to summarise tear pattern classification and management options for massive rotator cuff tears (MRCT), as well as to propose a treatment paradigm for patients with a MRCT. Data from 70 significant papers were reviewed in order to define the character of reparability and the possibility of alternative techniques in the management of MRCT. Massive rotator cuff tears (MRCT) include a wide panoply of lesions in terms of tear pattern, functional impairment, and reparability. Pre-operative evaluation is critical to successful treatment. With the advancement of medical technology, arthroscopy has become a frequently used method of treatment, even in cases of pseudoparalytic shoulders. Tendon transfer is limited to young patients with an irreparable MRCT and loss of active rotation. Arthroplasty can be considered for the treatment of a MRCT with associated arthritis. There is insufficient evidence to establish an evidence-based treatment algorithm for MRCTs. Treatment is based on patient factors and associated pathology, and includes personal experience and data from case series.

  9. Knowledge Discovery from Massive Healthcare Claims Data

    Energy Technology Data Exchange (ETDEWEB)

    Chandola, Varun [ORNL; Sukumar, Sreenivas R [ORNL; Schryver, Jack C [ORNL

    2013-01-01

    The role of big data in addressing the needs of the present healthcare system in US and rest of the world has been echoed by government, private, and academic sectors. There has been a growing emphasis to explore the promise of big data analytics in tapping the potential of the massive healthcare data emanating from private and government health insurance providers. While the domain implications of such collaboration are well known, this type of data has been explored to a limited extent in the data mining community. The objective of this paper is two fold: first, we introduce the emerging domain of big"healthcare claims data to the KDD community, and second, we describe the success and challenges that we encountered in analyzing this data using state of art analytics for massive data. Specically, we translate the problem of analyzing healthcare data into some of the most well-known analysis problems in the data mining community, social network analysis, text mining, and temporal analysis and higher order feature construction, and describe how advances within each of these areas can be leveraged to understand the domain of healthcare. Each case study illustrates a unique intersection of data mining and healthcare with a common objective of improving the cost-care ratio by mining for opportunities to improve healthcare operations and reducing hat seems to fall under fraud, waste,and abuse.

  10. MASSIVE PLEURAL EFFUSION: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Putu Bayu Dian Tresna Dewi

    2013-03-01

    Full Text Available Pleural effusion is abnormal fluid accumulation within pleural cavity between the parietal pleura and visceralis pleura, either transudation or exudates. A 47 year-old female presented with dyspneu, cough, and decreased of appetite. She had history of right lung tumor. Physical examination revealed asymmetric chest movement where right part of lung was lagged during breathing, vocal fremitus on the right chest was decreased, dullness at the right chest, decreased vesicular sound in the right chest, enlargement of supraclavicular and colli dextra lymph nodes, and hepatomegali. Complete blood count showed leukocytosis. Clinical chemistry analysis showed hipoalbumin and decreased liver function. Blood gas analysis showed hypoxemia. Pleural fluid analysis showed an exudates, murky red liquid color filled with erythrocytes, number of cells. Cytological examination showed existence of a non-small cell carcinoma tends adeno type. From chest X-ray showed massive right pleural effusion. Based on history, physical examination and investigations, she was diagnosed with massive pleural effusion et causa suspected malignancy. She had underwent pleural fluid evacuation and treated with analgesics and antibiotics.

  11. Massive Science with VO and Grids

    Science.gov (United States)

    Nichol, R.; Smith, G.; Miller, C.; Freeman, P.; Genovese, C.; Wasserman, L.; Bryan, B.; Gray, A.; Schneider, J.; Moore, A.

    2006-07-01

    There is a growing need for massive computational resources for the analysis of new astronomical datasets. To tackle this problem, we present here our first steps towards marrying two new and emerging technologies; the Virtual Observatory (e.g, AstroGrid) and the computational grid (e.g. TeraGrid, COSMOS etc.). We discuss the construction of VOTechBroker, which is a modular software tool designed to abstract the tasks of submission and management of a large number of computational jobs to a distributed computer system. The broker will also interact with the AstroGrid workflow and MySpace environments. We discuss our planned usages of the VOTechBroker in computing a huge number of n--point correlation functions from the SDSS data and massive model-fitting of millions of CMBfast models to WMAP data. We also discuss other applications including the determination of the XMM Cluster Survey selection function and the construction of new WMAP maps.

  12. Planckian Interacting Massive Particles as Dark Matter.

    Science.gov (United States)

    Garny, Mathias; Sandora, McCullen; Sloth, Martin S

    2016-03-11

    The standard model could be self-consistent up to the Planck scale according to the present measurements of the Higgs boson mass and top quark Yukawa coupling. It is therefore possible that new physics is only coupled to the standard model through Planck suppressed higher dimensional operators. In this case the weakly interacting massive particle miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian interacting massive particle, we show that the most natural mass larger than 0.01M_{p} is already ruled out by the absence of tensor modes in the cosmic microwave background (CMB). This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the Kaluza-Klein graviton mode as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar properties of this type of dark matter candidate. This paradigm therefore leads to a subtle connection between quantum gravity, the physics of primordial inflation, and the nature of dark matter.

  13. MASSIVE+: The Growth Histories of MASSIVE Survey Galaxies from their Globular Cluster Colors

    Science.gov (United States)

    Blakeslee, John

    2017-08-01

    The MASSIVE survey is targeting the 100 most massive galaxies within 108 Mpc that are visible in the northern sky. These most massive galaxies in the present-day universe reside in a surprisingly wide variety of environments, from rich clusters to fossil groups to near isolation. We propose to use WFC3/UVIS and ACS to carry out a deep imaging study of the globular cluster populations around a selected subset of the MASSIVE targets. Though much is known about GC systems of bright galaxies in rich clusters, we know surprisingly little about the effects of environment on these systems. The MASSIVE sample provides a golden opportunity to learn about the systematics of GC systems and what they can tell us about environmental drivers on the evolution of the highest mass galaxies. The most pressing questions to be addressed include: (1) Do isolated giants have the same constant mass fraction of GCs to total halo mass as BCGs of similar luminosity? (2) Do their GC systems show the same color (metallicity) distribution, which is an outcome of the mass spectrum of gas-rich halos during hierarchical growth? (3) Do the GCs in isolated high-mass galaxies follow the same radial distribution versus metallicity as in rich environments (a test of the relative importance of growth by accretion)? (4) Do the GCs of galaxies in sparse environments follow the same mass function? Our proposed second-band imaging will enable us to secure answers to these questions and add enormously to the legacy value of existing HST imaging of the highest mass galaxies in the universe.

  14. Neutron stars structure in the context of massive gravity

    Science.gov (United States)

    Hendi, S. H.; Bordbar, G. H.; Eslam Panah, B.; Panahiyan, S.

    2017-07-01

    Motivated by the recent interests in spin-2 massive gravitons, we study the structure of neutron star in the context of massive gravity. The modifications of TOV equation in the presence of massive gravity are explored in 4 and higher dimensions. Next, by considering the modern equation of state for the neutron star matter (which is extracted by the lowest order constrained variational (LOCV) method with the AV18 potential), different physical properties of the neutron star (such as Le Chatelier's principle, stability and energy conditions) are investigated. It is shown that consideration of the massive gravity has specific contributions into the structure of neutron star and introduces new prescriptions for the massive astrophysical objects. The mass-radius relation is examined and the effects of massive gravity on the Schwarzschild radius, average density, compactness, gravitational redshift and dynamical stability are studied. Finally, a relation between mass and radius of neutron star versus the Planck mass is extracted.

  15. Deployment and Implementation Strategies for Massive MIMO in 5G

    DEFF Research Database (Denmark)

    Panzner, Berthold; Zirwas, Wolfgang; Dierks, Stefan

    2015-01-01

    Massive MIMO has emerged as one technology enabler for the next generation mobile communications 5G. The gains promised by massive MIMO are augured to overcome the capacity crunch in today's mobile networks and to pave the way for the ambitious targets of 5G. The challenge to realize massive MIMO...... for 5G is a successful and cost-efficient integration in the overall network concept. This work highlights deployment and implementation strategies for massive MIMO in the context of 5G indoor small cell scenarios. Different massive MIMO deployment scenarios are analyzed for a standard 3GPP indoor...... to spatial streams is varied stepwise from equality to a factor of ten. For implementation of massive MIMO in 5G networks trends in beamforming techniques, mutually coupled subarrays, over the calibration procedure and estimated ADC performance in 2020 time-frame are discussed. Based on the debate the paper...

  16. Study of Stellar Clusters Containing Massive Stars

    Science.gov (United States)

    Costado, Teresa; Alfaro, E. J.; Delgado, A. J.; Djupvik, A. A.; Maíz Apellániz, J.

    2013-06-01

    Most stars form in clusters, but the percentage of stars born in dense stellar systems is currently matter of controversy and depends very much on the own definition of cluster. The cluster definition and hence the morphologies of individual clusters appear to vary significantly from region to region, as well as with age, which suggests that either, star formation in clusters is not universal and may depend on the local environment, or that all clusters form with the same morphology but early dynamical evolution quickly modifies the structure of the phase space distribution. In addition, young populated clusters containing massive stars are excellent labs for the study of the formation of the massive stellar component of the Galactic disk. Three main scenarios have been proposed for the formation of high-mass stars (M > 7-8 M_{⊙}): a) monolithic collapse of proto-stellar nuclei; b) competitive accretion inside the proto-cluster molecular cloud; and c) coalescence of proto-stellar nuclei and low-mass stars in very dense atmospheres. Both scientific questions: a) cluster formation and b) formation of high mass stars in clusters are intimately connected via the structural description of the phase space distribution of cluster stars and their Mass Function (MF). Models of static clusters with different initial spatial and kinematic distributions show how the spatial distribution dynamically evolves with time, allowing a characterization of their dynamical state from snapshots of their spatial distribution. Four are the main variables (and their distribution with mass and position) needed for a reliable characterization of the cluster dynamical state: a) Mass segregation parameter; b) Mapping of surface density for different ranges of masses; c) Q morphological parameter based on the minimum spanning tree graph and its variation with mass and cluster age, and d) MF of the cluster members. Two years ago, the Stellar System Group of IAA has begun an observational

  17. The Birth of Massive Stars and Star Clusters

    OpenAIRE

    Tan, Jonathan C.

    2005-01-01

    In the present-day universe, it appears that most, and perhaps all, massive stars are born in star clusters. It also appears that all star clusters contain stars drawn from an approximately universal initial mass function, so that almost all rich young star clusters contain massive stars. In this review I discuss the physical processes associated with both massive star formation and with star cluster formation. First I summarize the observed properties of star-forming gas clumps, then address...

  18. Volcanogenic sediments in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.

    and be transported thousands of kilometers depending upon the connectedness of vesicles. Earlier studies in CIOB suggested that pumice is of in-situ, Krakatau 1883 and Indonesian arc volcanic sources. Recently, we have carried out major, trace and REE data...

  19. Computational aeroacoustics on massively parallel computers

    Science.gov (United States)

    Oezyoeruek, Yusuf; Long, Lyle N.

    1995-01-01

    A computational fluid dynamics (CFD) technique is employed to solve aeroacoustics problems on massively parallel computers. The algorithm is based on a 4th order accurate central finite difference and 4th order accurate 4-stage Runge-Kutta time integration method that solves the 3-D full Navier-Stokes/Euler equations on a curvilinear coordinate system. The code has been developed to predict noise radiation from ducted fans. A specific application of this code is made here to the oscillating circular piston problem (Workshop Category 4, Problem 2) by solving the full Euler equations with nonreflecting boundary conditions in the axisymmetric mode. The features of the code that apply to this particular problem are described in this paper.

  20. Planckian Interacting Massive Particles as Dark Matter

    DEFF Research Database (Denmark)

    Garny, Mathias; Sandora, McCullen; Sloth, Martin S.

    2016-01-01

    . In this case the WIMP miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian Interacting Massive Particle......, we show that the most natural mass larger than $0.01\\,\\textrm{M}_p$ is already ruled out by the absence of tensor modes in the CMB. This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the KK graviton mode...... as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar properties of this type of dark matter candidate. This paradigm therefore leads to a subtle connection between quantum gravity, the physics of primordial inflation, and the nature of dark...

  1. Massive parallelism in the future of science

    Science.gov (United States)

    Denning, Peter J.

    1988-01-01

    Massive parallelism appears in three domains of action of concern to scientists, where it produces collective action that is not possible from any individual agent's behavior. In the domain of data parallelism, computers comprising very large numbers of processing agents, one for each data item in the result will be designed. These agents collectively can solve problems thousands of times faster than current supercomputers. In the domain of distributed parallelism, computations comprising large numbers of resource attached to the world network will be designed. The network will support computations far beyond the power of any one machine. In the domain of people parallelism collaborations among large groups of scientists around the world who participate in projects that endure well past the sojourns of individuals within them will be designed. Computing and telecommunications technology will support the large, long projects that will characterize big science by the turn of the century. Scientists must become masters in these three domains during the coming decade.

  2. PHYSIOLOGIC TRANSFUSION TRIGGERS AND MASSIVE TRANSFUSION

    Directory of Open Access Journals (Sweden)

    Tánczos Krisztián

    2013-01-01

    Full Text Available Blood transfusion is often a life saving intervention, but can also be harmful. Restrictive transfusion protocols have recently been developed with a post transfusion target haemoglobin level of 70–100 g/l. Whether haemoglobin level on its own is enough to guide our transfusion policy is an important issue. This review was aimed to look at other possible, so called physiological indicators of blood transfusion what clinicians can be used in addition to haemoglobin during their everyday practice. In the second part of the paper the problems of the management of massive bleeding are reviewed. In both cases, a complex approach is requiredtaking into consideration physiological changes in order to individualize treatment and hence avoid harm that can be caused by unnecessary transfusion of blood products.

  3. Production of massive particles during reheating

    CERN Document Server

    Chung, D J H; Riotto, Antonio; Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    What is commonly called the reheat temperature, $T_{RH}$, is not the maximum temperature obtained after inflation. The maximum temperature is, in fact, much larger than $T_{RH}$. As an application of this we consider the production of massive stable dark-matter particles of mass $M_X$ during reheating, and show that their abundance is suppressed as a power of $T_{RH}/M_X$ rather than times the reheat temperature may be produced in interesting abundance. In addition to dark matter, our analysis is relevant for baryogenesis if the baryon asymmetry is produced by the baryon (or lepton) number violating decays of superheavy bosons, and also for relic ultra-high energy cosmic rays if decays of superheavy particles are responsible for the highest energy cosmic rays.

  4. Hot, Massive Stars in I Zw 18

    Science.gov (United States)

    Heap, Sara R.; Lindler, D.; Malumuth, E.

    2011-01-01

    I Zw 18 is one of the most primitive blue, compact dwarf galaxies. The ionized gas in I Zw 18 has a low oxygen abundance (O approx.1/30 Osun) and nitrogen abundance (N-1/100 Nsun) (Pequignot 2008). We have obtained a far-UV spectrum of the northwest massive star cluster of I Zw 18 using Hubble's Cosmic Origins Spectrograph (COS). The spectrum is compatible with continuous star-formation over the past approx.10 Myr, and a very low metallicity, log Z/Zsun 1.7, although the stellar surface may be enhanced in carbon. Stellar wind lines are very weak, and the edge velocity of wind lines is very low (approx.250 km/s).

  5. Massive cortical reorganization in sighted Braille readers.

    Science.gov (United States)

    Siuda-Krzywicka, Katarzyna; Bola, Łukasz; Paplińska, Małgorzata; Sumera, Ewa; Jednoróg, Katarzyna; Marchewka, Artur; Śliwińska, Magdalena W; Amedi, Amir; Szwed, Marcin

    2016-03-15

    The brain is capable of large-scale reorganization in blindness or after massive injury. Such reorganization crosses the division into separate sensory cortices (visual, somatosensory...). As its result, the visual cortex of the blind becomes active during tactile Braille reading. Although the possibility of such reorganization in the normal, adult brain has been raised, definitive evidence has been lacking. Here, we demonstrate such extensive reorganization in normal, sighted adults who learned Braille while their brain activity was investigated with fMRI and transcranial magnetic stimulation (TMS). Subjects showed enhanced activity for tactile reading in the visual cortex, including the visual word form area (VWFA) that was modulated by their Braille reading speed and strengthened resting-state connectivity between visual and somatosensory cortices. Moreover, TMS disruption of VWFA activity decreased their tactile reading accuracy. Our results indicate that large-scale reorganization is a viable mechanism recruited when learning complex skills.

  6. Substructure of Highly Boosted Massive Jets

    Energy Technology Data Exchange (ETDEWEB)

    Alon, Raz [Weizmann Inst. of Science, Rehovot (Israel)

    2012-10-01

    Modern particle accelerators enable researchers to study new high energy frontiers which have never been explored before. This realm opens possibilities to further examine known fields such as Quantum Chromodynamics. In addition, it allows searching for new physics and setting new limits on the existence of such. This study examined the substructure of highly boosted massive jets measured by the CDF II detector. Events from 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron Collider were collected out of a total integrated luminosity of 5.95 fb$^{-1}$. They were selected to have at least one jet with transverse momentum above 400 GeV/c. The jet mass, angularity, and planar flow were measured and compared with predictions of perturbative Quantum Chromodynamics, and were found to be consistent with the theory. A search for boosted top quarks was conducted and resulted in an upper limit on the production cross section of such top quarks.

  7. MASSIVE INFANT STARS ROCK THEIR CRADLE

    Science.gov (United States)

    2002-01-01

    Extremely intense radiation from newly born, ultra-bright stars has blown a glowing spherical bubble in the nebula N83B, also known as NGC 1748. A new NASA Hubble Space Telescope image has helped to decipher the complex interplay of gas and radiation of a star-forming region in a nearby galaxy. The image graphically illustrates just how these massive stars sculpt their environment by generating powerful winds that alter the shape of the parent gaseous nebula. These processes are also seen in our Milky Way in regions like the Orion Nebula. The Hubble telescope is famous for its contribution to our knowledge about star formation in very distant galaxies. Although most of the stars in the Universe were born several billions of years ago, when the Universe was young, star formation still continues today. This new Hubble image shows a very compact star-forming region in a small part of one of our neighboring galaxies - the Large Magellanic Cloud. This galaxy lies only 165,000 light-years from our Milky Way and can easily be seen with the naked eye from the Southern Hemisphere. Young, massive, ultra-bright stars are seen here just as they are born and emerge from the shelter of their pre-natal molecular cloud. Catching these hefty stars at their birthplace is not as easy as it may seem. Their high mass means that the young stars evolve very rapidly and are hard to find at this critical stage. Furthermore, they spend a good fraction of their youth hidden from view, shrouded by large quantities of dust in a molecular cloud. The only chance is to observe them just as they start to emerge from their cocoon - and then only with very high-resolution telescopes. Astronomers from France, the U.S., and Germany have used Hubble to study the fascinating interplay between gas, dust, and radiation from the newly born stars in this nebula. Its peculiar and turbulent structure has been revealed for the first time. This high-resolution study has also uncovered several individual stars

  8. Massive stars. A chemical signature of first-generation very massive stars.

    Science.gov (United States)

    Aoki, W; Tominaga, N; Beers, T C; Honda, S; Lee, Y S

    2014-08-22

    Numerical simulations of structure formation in the early universe predict the formation of some fraction of stars with several hundred solar masses. No clear evidence of supernovae from such very massive stars has, however, yet been found in the chemical compositions of Milky Way stars. We report on an analysis of a very metal-poor star SDSS J001820.5-093939.2, which possesses elemental-abundance ratios that differ significantly from any previously known star. This star exhibits low [α-element Fe] ratios and large contrasts between the abundances of odd and even element pairs, such as scandium/titanium and cobalt/nickel. Such features have been predicted by nucleosynthesis models for supernovae of stars more than 140 times as massive as the Sun, suggesting that the mass distribution of first-generation stars might extend to 100 solar masses or larger. Copyright © 2014, American Association for the Advancement of Science.

  9. The Formation of Massive Molecular Filaments and Massive Stars Triggered by a MHD Shock Wave

    OpenAIRE

    Inoue, Tsuyoshi; Hennebelle, Patrick; Fukui, Yasuo; Matsumoto, Tomoaki; Iwasaki, Kazunari; Inutsuka, Shu-ichiro

    2017-01-01

    Recent observations suggest that intensive molecular cloud collision can trigger massive star/cluster formation. The most important physical process caused by the collision is a shock compression. In this paper, the influence of a shock wave on the evolution of a molecular cloud is studied numerically by using isothermal magnetohydrodynamics (MHD) simulations with the effect of self-gravity. Adaptive-mesh-refinement and sink particle techniques are used to follow long-time evolution of the sh...

  10. [Massive pulmonary embolism. When medical treatment is not enough].

    Science.gov (United States)

    Gerardin, B; Glorion, M; Rodriguez, A; Garcia, C; Stephan, F; Fabre, D; Mercier, O; Brenot, P; Fadel, E

    2017-12-01

    Emergency bedside veno-arterious ECMO implantation can be the only saving gesture in the suspicion of acute massive pulmonary embolism leading to haemodynamic failure, even before CT-scan imaging. Once the massive pulmonary embolism is confirmed it is possible to undergo surgical or percutaneous pulmonary thrombectomy, when thrombolytic therapy is contraindicated. Copyright © 2017. Published by Elsevier SAS.

  11. Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Thomas; /ZAH, Heidelberg; Klessen, Ralf S.; /ZAH, Heidelberg /KIPAC, Menlo Park; Mac Low, Mordecai-Mark; /Amer. Museum Natural Hist.; Banerjee, Robi; /ZAH, Heidelberg

    2010-08-25

    Massive stars influence their surroundings through radiation, winds, and supernova explosions far out of proportion to their small numbers. However, the physical processes that initiate and govern the birth of massive stars remain poorly understood. Two widely discussed models are monolithic collapse of molecular cloud cores and competitive accretion. To learn more about massive star formation, we perform simulations of the collapse of rotating, massive, cloud cores including radiative heating by both non-ionizing and ionizing radiation using the FLASH adaptive mesh refinement code. These simulations show fragmentation from gravitational instability in the enormously dense accretion flows required to build up massive stars. Secondary stars form rapidly in these flows and accrete mass that would have otherwise been consumed by the massive star in the center, in a process that we term fragmentation-induced starvation. This explains why massive stars are usually found as members of high-order stellar systems that themselves belong to large clusters containing stars of all masses. The radiative heating does not prevent fragmentation, but does lead to a higher Jeans mass, resulting in fewer and more massive stars than would form without the heating. This mechanism reproduces the observed relation between the total stellar mass in the cluster and the mass of the largest star. It predicts strong clumping and filamentary structure in the center of collapsing cores, as has recently been observed. We speculate that a similar mechanism will act during primordial star formation.

  12. A spin-4 analog of 3D massive gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Kovacevic, Marija; Rosseel, Jan; Townsend, Paul K.; Yin, Yihao

    2011-01-01

    A sixth-order, but ghost-free, gauge-invariant action is found for a fourth-rank symmetric tensor potential in a three-dimensional (3D) Minkowski spacetime. It propagates two massive modes of spin 4 that are interchanged by parity and is thus a spin-4 analog of linearized 'new massive gravity'. Also

  13. Massive Star Formation: Accreting from Companion X. Chen1 ...

    Indian Academy of Sciences (India)

    system composed of a diffuse object (possible nebulae or UC HII region) and a Massive Young Stellar Object (MYSO) seen in Spitzer IRAC image. The diffuse object and MYSO are connected by the ... Infrared: ISM—stars: formation—ISM: jets and outflows. 1. Introduction. The dynamics processes in Massive Star Formation ...

  14. The properties of low-metallicity massive stars

    NARCIS (Netherlands)

    Tramper, F.

    2014-01-01

    My thesis has two main topics: the study of low-metallicity massive stars, and the study of the suspected final stage of massive stars from a certain initial mass range, the WO stars. All the data that has been used in this thesis has been obtained with the X-Shooter spectrograph on ESO's Very Large

  15. Massive vulval oedema in multiple pregnancies at Bugando Medical ...

    African Journals Online (AJOL)

    Abstract: Massive vulval oedema is not common during pregnancy, but when it develops, it often is associated with patient discomfort and management challenges. Two pregnant women presented to Bugando Medical Centre in Mwanza, Tanzania, with massive swelling of the vulva at 39 weeks and 32 weeks of gestation.

  16. Complicated Massive Choledochal Cyst: A Case Report | Okoromah ...

    African Journals Online (AJOL)

    Choledochal cysts are rare congenital anomalies resulting from congenital dilatations of the common bile duct (CBD) and usually they present during infancy with cholestatic jaundice. This report is on a massive-sized choledochal cyst associated with massive abdominal distention, respiratory embarrassment, postprandial ...

  17. On massive gravitons in 2+1 dimensions

    NARCIS (Netherlands)

    Bergshoeff, Eric; Hohm, Olaf; Townsend, Paul; Lazkoz, R; Vera, R

    2010-01-01

    The Fierz-Pauli (FP) free field theory for massive spin-2 particles can be extended, in a spacetime of (1+2) dimensions (3D), to a generally covariant parity-preserving interacting field theory, in at least two ways. One is "new massive gravity" (NMG), with an action that involves curvature-squared

  18. Massive Splenomegaly in Children: Laparoscopic Versus Open Splenectomy

    OpenAIRE

    Hassan, Mohamed E.; Al Ali, Khalid

    2014-01-01

    Background and Objectives: Laparoscopic splenectomy for massive splenomegaly is still a controversial procedure as compared with open splenectomy. We aimed to compare the feasibility of laparoscopic splenectomy versus open splenectomy for massive splenomegaly from different surgical aspects in children. Methods: The data of children aged

  19. Massive weight loss-induced mechanical plasticity in obese gait

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Herring, Cortney; Pories, Walter J.; Rider, Patrick; DeVita, Paul

    2011-01-01

    Hortobagyi T, Herring C, Pories WJ, Rider P, DeVita P. Massive weight loss-induced mechanical plasticity in obese gait. J Appl Physiol 111: 1391-1399, 2011. First published August 18, 2011; doi:10.1152/japplphysiol.00291.2011.-We examined the hypothesis that metabolic surgery-induced massive weight

  20. Massive Born--Infeld and Other Dual Pairs

    CERN Document Server

    Ferrara, S

    2015-01-01

    We consider massive dual pairs of p-forms and (D-p-1)-forms described by non-linear Lagrangians, where non-linear curvature terms in one theory translate into non-linear mass-like terms in the dual theory. In particular, for D=2p and p even the two non-linear structures coincide when the non-linear massless theory is self-dual. This state of affairs finds a natural realization in the four-dimensional massive N=1 supersymmetric Born-Infeld action, which describes either a massive vector multiplet or a massive linear (tensor) multiplet with a Born-Infeld mass-like term. These systems should play a role for the massive gravitino multiplet obtained from a partial super-Higgs in N=2 Supergravity.

  1. Mass loss from very young massive stars

    Science.gov (United States)

    Henning, Th.

    The physics of mass loss from very young massive stars is reviewed, and mass-loss rates are determined for several objects on the basis of published observational data. The observational evidence for mass loss of 0.0001-0.001 solar mass/yr with velocity 10-60 km/s, dynamical timescale 1000-100,000 yr, and kinetic energy (1-100) x 10 to the 38th W from these objects is chracterized; techniques for estimating mass-loss rates from H recombination lines, CO line profiles maser data, and IR-continuum observations are described; rates for molecular outflows and ionized winds are presented in tabels; and theoretical models developed to explain the mechanism driving bipolar mass loss are examined critically. It is found that neither radiation pressure on dust grins nor the ionized winds can drive the molecular outflow. The models considered most probable are those involving production of holes by original spherical stellar winds (Canto, 1980, rotationally driven magnetic pressure (Draine, 1983), and infall from an accretion disk (Torbett, 1984).

  2. Massive Tension Pneumocephalus Following Cochlear Implant Surgery.

    Science.gov (United States)

    Di Lella, Filippo; D'Angelo, Giulia; Iaccarino, Ilaria; Piccinini, Silvia; Negri, Maurizio; Vincenti, Vincenzo

    2016-10-01

    To report clinical presentation, management and outcomes of a rare complication of cochlear implant surgery. A 68-year-old man, affected by profound bilateral deafness because of superficial cerebral hemosiderosis, presented to Authors' Department 8 days after cochlear implant surgery with vomiting, fever, and mental confusion. Brain computed tomographic (CT) scan showed a massive collection of intracranial air from an osteodural defect in the right tegmen mastoideum because of repeated nose blowing in the postoperative period. A multilayer reconstruction of the tegmen with obliteration of the mastoid cavity using abdominal subcutaneous adipose tissue was performed, preserving the cochlear implant in place. Following surgery the patient showed rapid neurological improvement and CT scan performed 2 days later showed complete resolution of the intracranial air collection. He is currently using the cochlear implant with open set performances. Pneumocephalus is a rare complication of cochlear implant surgery. In patients with severe neurological signs following cochlear implantation (CI), pneumocephalus should be suspected. Drilling of mastoid air cells may expose dura mater and positive high pressure events may break meningeal layers and force air into the cranial cavity.

  3. Planckian Interacting Massive Particles as Dark Matter

    CERN Document Server

    Garny, Mathias; Sloth, Martin S.

    2016-03-10

    The Standard Model could be self-consistent up to the Planck scale according to the present measurements of the Higgs mass and top quark Yukawa coupling. It is therefore possible that new physics is only coupled to the Standard Model through Planck suppressed higher dimensional operators. In this case the WIMP miracle is a mirage, and instead minimality as dictated by Occam's razor would indicate that dark matter is related to the Planck scale, where quantum gravity is anyway expected to manifest itself. Assuming within this framework that dark matter is a Planckian Interacting Massive Particle, we show that the most natural mass larger than $0.01\\,\\textrm{M}_p$ is already ruled out by the absence of tensor modes in the CMB. This also indicates that we expect tensor modes in the CMB to be observed soon for this type of minimal dark matter model. Finally, we touch upon the KK graviton mode as a possible realization of this scenario within UV complete models, as well as further potential signatures and peculiar...

  4. Multiplexed microsatellite recovery using massively parallel sequencing

    Science.gov (United States)

    Jennings, T.N.; Knaus, B.J.; Mullins, T.D.; Haig, S.M.; Cronn, R.C.

    2011-01-01

    Conservation and management of natural populations requires accurate and inexpensive genotyping methods. Traditional microsatellite, or simple sequence repeat (SSR), marker analysis remains a popular genotyping method because of the comparatively low cost of marker development, ease of analysis and high power of genotype discrimination. With the availability of massively parallel sequencing (MPS), it is now possible to sequence microsatellite-enriched genomic libraries in multiplex pools. To test this approach, we prepared seven microsatellite-enriched, barcoded genomic libraries from diverse taxa (two conifer trees, five birds) and sequenced these on one lane of the Illumina Genome Analyzer using paired-end 80-bp reads. In this experiment, we screened 6.1 million sequences and identified 356958 unique microreads that contained di- or trinucleotide microsatellites. Examination of four species shows that our conversion rate from raw sequences to polymorphic markers compares favourably to Sanger- and 454-based methods. The advantage of multiplexed MPS is that the staggering capacity of modern microread sequencing is spread across many libraries; this reduces sample preparation and sequencing costs to less than $400 (USD) per species. This price is sufficiently low that microsatellite libraries could be prepared and sequenced for all 1373 organisms listed as 'threatened' and 'endangered' in the United States for under $0.5M (USD).

  5. Massive Black Holes in Central Cluster Galaxies

    Science.gov (United States)

    Volonteri, Marta; Ciotti, Luca

    2013-05-01

    We explore how the co-evolution of massive black holes (MBHs) and galaxies is affected by environmental effects, addressing in particular MBHs hosted in the central cluster galaxies (we will refer to these galaxies in general as "CCGs"). Recently, the sample of MBHs in CCGs with dynamically measured masses has increased, and it has been suggested that these MBH masses (M BH) deviate from the expected correlations with velocity dispersion (σ) and mass of the bulge (M bulge) of the host galaxy: MBHs in CCGs appear to be "overmassive." This discrepancy is more pronounced when considering the M BH-σ relation than the M BH-M bulge one. We show that this behavior stems from a combination of two natural factors: (1) CCGs experience more mergers involving spheroidal galaxies and their MBHs and (2) such mergers are preferentially gas poor. We use a combination of analytical and semi-analytical models to investigate the MBH-galaxy co-evolution in different environments and find that the combination of these two factors is in accordance with the trends observed in current data sets.

  6. MASSIVE BLACK HOLES IN CENTRAL CLUSTER GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Volonteri, Marta [Institut d' Astrophysique de Paris, 98bis Bd. Arago, F-75014 Paris (France); Ciotti, Luca [Dipartimento di Fisica e Astronomia, Universita di Bologna, via Ranzani 1, I-40127 Bologna (Italy)

    2013-05-01

    We explore how the co-evolution of massive black holes (MBHs) and galaxies is affected by environmental effects, addressing in particular MBHs hosted in the central cluster galaxies (we will refer to these galaxies in general as ''CCGs''). Recently, the sample of MBHs in CCGs with dynamically measured masses has increased, and it has been suggested that these MBH masses (M{sub BH}) deviate from the expected correlations with velocity dispersion ({sigma}) and mass of the bulge (M{sub bulge}) of the host galaxy: MBHs in CCGs appear to be ''overmassive''. This discrepancy is more pronounced when considering the M{sub BH}-{sigma} relation than the M{sub BH}-M{sub bulge} one. We show that this behavior stems from a combination of two natural factors: (1) CCGs experience more mergers involving spheroidal galaxies and their MBHs and (2) such mergers are preferentially gas poor. We use a combination of analytical and semi-analytical models to investigate the MBH-galaxy co-evolution in different environments and find that the combination of these two factors is in accordance with the trends observed in current data sets.

  7. Massive stars in their death throes.

    Science.gov (United States)

    Eldridge, John J

    2008-12-13

    The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently, there are eight detected progenitors with another 21 non-detections, for which only a limit on the pre-explosion luminosity can be placed. This new avenue of supernova research has led to many interesting conclusions, most importantly that the progenitors of the most common supernovae, type IIP, are red supergiants, as theory has long predicted. However, no progenitors have been detected thus far for the hydrogen-free type Ib/c supernovae, which, given the expected progenitors, is an unlikely result. Also, observations have begun to show evidence that luminous blue variables, which are among the most massive stars, may directly explode as supernovae. These results contradict the current stellar evolution theory. This suggests that we may need to update our understanding.

  8. Collective excitations of massive flavor branes

    Directory of Open Access Journals (Sweden)

    Georgios Itsios

    2016-08-01

    Full Text Available We study the intersections of two sets of D-branes of different dimensionalities. This configuration is dual to a supersymmetric gauge theory with flavor hypermultiplets in the fundamental representation of the gauge group which live on the defect of the unflavored theory determined by the directions common to the two types of branes. One set of branes is dual to the color degrees of freedom, while the other set adds flavor to the system. We work in the quenched approximation, i.e., where the flavor branes are considered as probes, and focus specifically on the case in which the quarks are massive. We study the thermodynamics and the speeds of first and zero sound at zero temperature and non-vanishing chemical potential. We show that the system undergoes a quantum phase transition when the chemical potential approaches its minimal value and we obtain the corresponding non-relativistic critical exponents that characterize its critical behavior. In the case of (2+1-dimensional intersections, we further study alternative quantization and the zero sound of the resulting anyonic fluid. We finally extend these results to non-zero temperature and magnetic field and compute the diffusion constant in the hydrodynamic regime. The numerical results we find match the predictions by the Einstein relation.

  9. MASSIVE HYBRID PARALLELISM FOR FULLY IMPLICIT MULTIPHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Cody J. Permann; David Andrs; John W. Peterson; Derek R. Gaston

    2013-05-01

    As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided.

  10. EFFECTIVE SUMMARY FOR MASSIVE DATA SET

    Directory of Open Access Journals (Sweden)

    A. Radhika

    2015-07-01

    Full Text Available The research efforts attempt to investigate size of the data increasing interest in designing the effective algorithm for space and time reduction. Providing high-dimensional technique over large data set is difficult. However, Randomized techniques are used for analyzing the data set where the performance of the data from part of storage in networks needs to be collected and analyzed continuously. Previously collaborative filtering approach is used for finding the similar patterns based on the user ranking but the outcomes are not observed yet. Linear approach requires high running time and more space. To overcome this sketching technique is used to represent massive data sets. Sketching allows short fingerprints of the item sets of users which allow approximately computing similarity between sets of different users. The concept of sketching is to generate minimum subset of record that executes all the original records. Sketching performs two techniques dimensionality reduction which reduces rows or columns and data reduction. It is proved that sketching can be performed using Principal Component Analysis for finding index value

  11. Massively Parallel Dimension Independent Adaptive Metropolis

    KAUST Repository

    Chen, Yuxin

    2015-05-14

    This work considers black-box Bayesian inference over high-dimensional parameter spaces. The well-known and widely respected adaptive Metropolis (AM) algorithm is extended herein to asymptotically scale uniformly with respect to the underlying parameter dimension, by respecting the variance, for Gaussian targets. The result- ing algorithm, referred to as the dimension-independent adaptive Metropolis (DIAM) algorithm, also shows improved performance with respect to adaptive Metropolis on non-Gaussian targets. This algorithm is further improved, and the possibility of probing high-dimensional targets is enabled, via GPU-accelerated numerical libraries and periodically synchronized concurrent chains (justified a posteriori). Asymptoti- cally in dimension, this massively parallel dimension-independent adaptive Metropolis (MPDIAM) GPU implementation exhibits a factor of four improvement versus the CPU-based Intel MKL version alone, which is itself already a factor of three improve- ment versus the serial version. The scaling to multiple CPUs and GPUs exhibits a form of strong scaling in terms of the time necessary to reach a certain convergence criterion, through a combination of longer time per sample batch (weak scaling) and yet fewer necessary samples to convergence. This is illustrated by e ciently sampling from several Gaussian and non-Gaussian targets for dimension d 1000.

  12. Massively parallel microscopic particle-in-cell

    Science.gov (United States)

    Bart, G.; Peltz, C.; Bigaouette, N.; Fennel, T.; Brabec, T.; Varin, C.

    2017-10-01

    The microscopic particle-in-cell (MicPIC) method was developed to model classical light-matter interaction in strongly-coupled plasma systems. It effectively overcomes the limitations of the particle-in-cell and molecular dynamics techniques by combining them into a single, unified framework to solve for both electromagnetic wave propagation and atomic-scale collision processes in a self-consistent treatment. Its effective time complexity is O(N) , where N is the number of model particles, which is ideal for studying the dynamics of large ensembles. In this paper, we show that through massively parallel, distributed computations, current implementations of the MicPIC approach can handle up to 1011 particles on an IBM Blue Gene/Q computer with 65 536 physical cores. This allows modelling volumes of matter of approximately 1 μm3 at solid gold density, opening a wealth of potential applications of MicPIC in nanophotonics, diffractive X-ray imaging, and strong-field science.

  13. Massive neutral particles on heterotic string theory

    CERN Document Server

    Olivares, Marco

    2013-01-01

    The motion of massive particles in the background of a charged black hole in heterotic string theory, which is characterized by a parameter $\\alpha$, is studied in detail across this paper. Since it is possible to write this space-time in the Einstein frame, we perform a quantitative analysis of the time-like geodesics by means of the standard Lagrange procedure. Thus, we obtain and solve a set of differential equations and then we describe the orbits in terms of elliptic $\\wp$-Weierstra{\\ss} function. Also, by making an elementary derivation developed by Cornbleet (Am. J. Phys. \\textbf{61} 7, (1993) 650 - 651) we obtain the correction to the angle of advance of perihelion to first order in $\\alpha$, and thus, by comparing with Mercury's data we give an estimation for the value of this parameter, which yields to an {\\it heterotic solar charge} $Q_{\\odot}\\simeq 0.728\\,[\\textrm{Km}]= 0.493\\, M_{\\odot}$. Therefore, in addition with the study on null geodesics performed by Fernando (Phys. Rev. D {\\bf 85}, (2012) ...

  14. Mining knowledge in astrophysical massive data sets

    Energy Technology Data Exchange (ETDEWEB)

    Brescia, Massimo, E-mail: brescia@na.astro.i [INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli (Italy); Longo, Giuseppe [Dipartimento di Fisica, Universita degli Studi Federico II, Via Cintia 26, 80125 Napoli (Italy); Pasian, Fabio [INAF-Osservatorio Astronomico di Trieste, Via Tiepolo 11, 34143 Trieste (Italy)

    2010-11-11

    Modern scientific data mainly consist of huge data sets gathered by a very large number of techniques and stored in much diversified and often incompatible data repositories. More in general, in the e-science environment, it is considered as a critical and urgent requirement to integrate services across distributed, heterogeneous, dynamic 'virtual organizations' formed by different resources within a single enterprise. In the last decade, Astronomy has become an immensely data-rich field due to the evolution of detectors (plates to digital to mosaics), telescopes and space instruments. The Virtual Observatory approach consists of the federation under common standards of all astronomical archives available worldwide, as well as data analysis, data mining and data exploration applications. The main drive behind such an effort is that once the infrastructure is complete, it will allow a new type of multi-wavelength, multi-epoch science, which can only be barely imagined. Data mining, or knowledge discovery in databases, while being the main methodology to extract the scientific information contained in such Massive Data Sets (MDS), poses crucial problems since it has to orchestrate complex problems posed by transparent access to different computing environments, scalability of algorithms, reusability of resources, etc. In the present paper we summarize the present status of the MDS in the Virtual Observatory and what is currently done and planned to bring advanced data mining methodologies in the case of the DAME (DAta Mining and Exploration) project.

  15. Is rehabilitation effective in massive rotator cuff tears?

    Science.gov (United States)

    Collin, P G; Gain, S; Nguyen Huu, F; Lädermann, A

    2015-06-01

    Irreparable massive rotator cuff tears are challenging to treat. Our objective here was to evaluate the efficacy of a specifically designed rehabilitation programme. We hypothesised that outcomes of the rehabilitation programme would vary with the site of the tears. Patients with irreparable massive rotator cuff tears and shoulder pseudoparalysis were included prospectively. They followed a five-session specific rehabilitation programme. The outcomes were analysed according to the site of the tears. We included 45 patients with a mean age of 67 years. At last follow-up after rehabilitation, 24 patients had recovered more than 160° of anterior shoulder elevation. Treatment failure was common in patients with massive anterior rotator cuff tears or tears involving three or more tendons. Patients with massive posterior tears, in contrast, often experienced substantial improvements, even in the medium term. Outcomes of rehabilitation therapy in patients with irreparable massive rotator cuff tears and shoulder pseudoparalysis vary according to the site and number of the tears. Failure of rehabilitation therapy is common in patients with massive anterior tears or tears involving at least three tendons. In contrast, in patients with isolated massive posterior tears, substantial benefits from rehabilitation therapy can be expected. III. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Bridging the gap: from massive stars to supernovae

    Science.gov (United States)

    Maund, Justyn R.; Crowther, Paul A.; Janka, Hans-Thomas; Langer, Norbert

    2017-09-01

    Almost since the beginning, massive stars and their resultant supernovae have played a crucial role in the Universe. These objects produce tremendous amounts of energy and new, heavy elements that enrich galaxies, encourage new stars to form and sculpt the shapes of galaxies that we see today. The end of millions of years of massive star evolution and the beginning of hundreds or thousands of years of supernova evolution are separated by a matter of a few seconds, in which some of the most extreme physics found in the Universe causes the explosive and terminal disruption of the star. Key questions remain unanswered in both the studies of how massive stars evolve and the behaviour of supernovae, and it appears the solutions may not lie on just one side of the explosion or the other or in just the domain of the stellar evolution or the supernova astrophysics communities. The need to view massive star evolution and supernovae as continuous phases in a single narrative motivated the Theo Murphy international scientific meeting `Bridging the gap: from massive stars to supernovae' at Chicheley Hall, UK, in June 2016, with the specific purpose of simultaneously addressing the scientific connections between theoretical and observational studies of massive stars and their supernovae, through engaging astronomers from both communities. This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'.

  17. Bridging the gap: from massive stars to supernovae.

    Science.gov (United States)

    Maund, Justyn R; Crowther, Paul A; Janka, Hans-Thomas; Langer, Norbert

    2017-10-28

    Almost since the beginning, massive stars and their resultant supernovae have played a crucial role in the Universe. These objects produce tremendous amounts of energy and new, heavy elements that enrich galaxies, encourage new stars to form and sculpt the shapes of galaxies that we see today. The end of millions of years of massive star evolution and the beginning of hundreds or thousands of years of supernova evolution are separated by a matter of a few seconds, in which some of the most extreme physics found in the Universe causes the explosive and terminal disruption of the star. Key questions remain unanswered in both the studies of how massive stars evolve and the behaviour of supernovae, and it appears the solutions may not lie on just one side of the explosion or the other or in just the domain of the stellar evolution or the supernova astrophysics communities. The need to view massive star evolution and supernovae as continuous phases in a single narrative motivated the Theo Murphy international scientific meeting 'Bridging the gap: from massive stars to supernovae' at Chicheley Hall, UK, in June 2016, with the specific purpose of simultaneously addressing the scientific connections between theoretical and observational studies of massive stars and their supernovae, through engaging astronomers from both communities.This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'. © 2017 The Author(s).

  18. Massive Black Hole Implicated in Stellar Destruction

    Science.gov (United States)

    2010-01-01

    New results from NASA's Chandra X-ray Observatory and the Magellan telescopes suggest that a dense stellar remnant has been ripped apart by a black hole a thousand times as massive as the Sun. If confirmed, this discovery would be a cosmic double play: it would be strong evidence for an intermediate mass black hole, which has been a hotly debated topic, and would mark the first time such a black hole has been caught tearing a star apart. This scenario is based on Chandra observations, which revealed an unusually luminous source of X-rays in a dense cluster of old stars, and optical observations that showed a peculiar mix of elements associated with the X-ray emission. Taken together, a case can be made that the X-ray emission is produced by debris from a disrupted white dwarf star that is heated as it falls towards a massive black hole. The optical emission comes from debris further out that is illuminated by these X-rays. The intensity of the X-ray emission places the source in the "ultraluminous X-ray source" or ULX category, meaning that it is more luminous than any known stellar X-ray source, but less luminous than the bright X-ray sources (active galactic nuclei) associated with supermassive black holes in the nuclei of galaxies. The nature of ULXs is a mystery, but one suggestion is that some ULXs are black holes with masses between about a hundred and several thousand times that of the Sun, a range intermediate between stellar-mass black holes and supermassive black holes located in the nuclei of galaxies. This ULX is in a globular cluster, a very old and crowded conglomeration of stars. Astronomers have suspected that globular clusters could contain intermediate-mass black holes, but conclusive evidence for this has been elusive. "Astronomers have made cases for stars being torn apart by supermassive black holes in the centers of galaxies before, but this is the first good evidence for such an event in a globular cluster," said Jimmy Irwin of the University

  19. Very early stages of massive stars

    Science.gov (United States)

    Vasyunina, Tatiana

    2010-12-01

    The goal of this thesis work is to investigate the initial conditions and the early phases of the formation of high-mass stars by means of dedicated observational studies. We consider two object classes: infrared dark clouds (IRDCs), and a subsequent stage characterized by the presence of young embedded (proto-)stellar clusters. First, we estimate masses and column densities for a completely new sample of southern IRDCs, utilizing our own millimeter continuum emission maps as well as Spitzer satellite data. The parameters we derive show that IRDCs from our sample have the potential to form not only low- and intermediate-mass stars, but can also be the birth places of massive stars. In particular, the comparison of our results with previously obtained data for low-mass starless cores shows a clear trend for IRDCs to have systematically higher column densities. The interpolated IRDC peak column densities exceed the threshold for the onset of massive star formation previously advocated by theoretical studies. We also critically evaluate the limitations of the applied emission and extinction methods. Second, we investigate the physical conditions and the chemical composition of the dense gas within the IRDCs of our sample by means of a multi-line molecular spectroscopy analysis. All the clouds have complex HCO+ line pro les, and we detect SiO emission in some clouds. These ndings mark the presence of infall and out ow motions in at least some parts of the IRDCs, and hence, ongoing star formation. In comparison with low-mass starless cores, the IRDCs have broader and more intense lines. Thus, they may be characterised by more turbulent conditions. Nevertheless, we nd a tendency for the IRDCs to have molecular abundances similar to the case of low-mass starless cores. This indicates similar chemical initial conditions for low- and high-mass star-forming regions. Finally, we study the stellar composition and environmental conditions in the young embedded cluster IRAS

  20. Two Senses of Massive Truth in Donald Davidson's Philosophy

    OpenAIRE

    Melogno, Pablo

    2012-01-01

    The present paper proposes a critical revision of the massive truth notion, in the context of Donald Davidson’s criticism to skepticism. It´s distinguished in Davidson’s work a cuantitative sense and a cualitative sense of the massive truth, asserting that the first one has been more frequently used and has had just an intuitive level of elucidation. The main problems associated to the cuantitative notion of massive truth are revised in relation to the quantification of beliefs, the detection...

  1. Massive Black Hole Binaries: Dynamical Evolution and Observational Signatures

    Directory of Open Access Journals (Sweden)

    M. Dotti

    2012-01-01

    Full Text Available The study of the dynamical evolution of massive black hole pairs in mergers is crucial in the context of a hierarchical galaxy formation scenario. The timescales for the formation and the coalescence of black hole binaries are still poorly constrained, resulting in large uncertainties in the expected rate of massive black hole binaries detectable in the electromagnetic and gravitational wave spectra. Here, we review the current theoretical understanding of the black hole pairing in galaxy mergers, with a particular attention to recent developments and open issues. We conclude with a review of the expected observational signatures of massive binaries and of the candidates discussed in literature to date.

  2. Asymptotic symmetries of gravity and soft theorems for massive particles

    Energy Technology Data Exchange (ETDEWEB)

    Campiglia, Miguel [Instituto de Física, Facultad de Ciencias, Universidad de la República,Iguá 4225, Montevideo (Uruguay); Laddha, Alok [Chennai Mathematical Institute,SIPCOT IT Park, Siruseri 603103 (India)

    2015-12-15

    The existing equivalence between (generalized) BMS Ward identities with leading and subleading soft graviton theorems is extended to the case where the scattering particles are massive scalars. By extending the action of generalized BMS group off null infinity at late times, we show that there is a natural action of such group not only on the radiative data at null infinity but also on the scattering data of the massive scalar field. This leads to a formulation of Ward identities associated to the generalized BMS group when the scattering states are massive scalars or massless gravitons and we show that these Ward identities are equivalent to the leading and subleading soft graviton theorems.

  3. A Massive-born Neutron Star with a Massive White Dwarf Companion

    Science.gov (United States)

    Cognard, Ismaël; Freire, Paulo C. C.; Guillemot, Lucas; Theureau, Gilles; Tauris, Thomas M.; Wex, Norbert; Graikou, Eleni; Kramer, Michael; Stappers, Benjamin; Lyne, Andrew G.; Bassa, Cees; Desvignes, Gregory; Lazarus, Patrick

    2017-08-01

    We report on the results of a 4 year timing campaign of PSR J2222-0137, a 2.44 day binary pulsar with a massive white dwarf (WD) companion, with the Nançay, Effelsberg, and Lovell radio telescopes. Using the Shapiro delay for this system, we find a pulsar mass m p = 1.76 ± 0.06 M ⊙ and a WD mass m c = 1.293 ± 0.025 M ⊙. We also measure the rate of advance of periastron for this system, which is marginally consistent with the general relativity prediction for these masses. The short lifetime of the massive WD progenitor star led to a rapid X-ray binary phase with little (< 10-2 M ⊙) mass accretion onto the neutron star; hence, the current pulsar mass is, within uncertainties, its birth mass, which is the largest measured to date. We discuss the discrepancy with previous mass measurements for this system; we conclude that the measurements presented here are likely to be more accurate. Finally, we highlight the usefulness of this system for testing alternative theories of gravity by tightly constraining the presence of dipolar radiation. This is of particular importance for certain aspects of strong-field gravity, like spontaneous scalarization, since the mass of PSR J2222-0137 puts that system into a poorly tested parameter range.

  4. A Massive-born Neutron Star with a Massive White Dwarf Companion

    Energy Technology Data Exchange (ETDEWEB)

    Cognard, Ismaël; Guillemot, Lucas; Theureau, Gilles [Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, Université d’Orléans/CNRS, F-45071 Orléans Cedex 02 (France); Freire, Paulo C. C. [Station de radioastronomie de Nançay, Observatoire de Paris, CNRS/INSU, F-18330 Nançay (France); Tauris, Thomas M.; Wex, Norbert; Graikou, Eleni; Kramer, Michael; Desvignes, Gregory; Lazarus, Patrick [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Stappers, Benjamin; Lyne, Andrew G. [Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, The University of Manchester, M13 9PL (United Kingdom); Bassa, Cees [ASTRON, The Netherlands Institute for Radioastronomy, Postbus 2, 7900 AA, Dwingeloo (Netherlands)

    2017-08-01

    We report on the results of a 4 year timing campaign of PSR J2222−0137, a 2.44 day binary pulsar with a massive white dwarf (WD) companion, with the Nançay, Effelsberg, and Lovell radio telescopes. Using the Shapiro delay for this system, we find a pulsar mass m {sub p} = 1.76 ± 0.06 M {sub ⊙} and a WD mass m {sub c} = 1.293 ± 0.025 M {sub ⊙}. We also measure the rate of advance of periastron for this system, which is marginally consistent with the general relativity prediction for these masses. The short lifetime of the massive WD progenitor star led to a rapid X-ray binary phase with little (< 10{sup −2} M {sub ⊙}) mass accretion onto the neutron star; hence, the current pulsar mass is, within uncertainties, its birth mass, which is the largest measured to date. We discuss the discrepancy with previous mass measurements for this system; we conclude that the measurements presented here are likely to be more accurate. Finally, we highlight the usefulness of this system for testing alternative theories of gravity by tightly constraining the presence of dipolar radiation. This is of particular importance for certain aspects of strong-field gravity, like spontaneous scalarization, since the mass of PSR J2222−0137 puts that system into a poorly tested parameter range.

  5. Visualisation of Massive Military Datasets: Human Factors, Applications, and Technologies

    National Research Council Canada - National Science Library

    2001-01-01

    This final report of IST-0l3/RTG-O()2 "Visualisation of Massive Military Datasets" presents some of the issues involved in visualisation as well as techniques that have been used in support of visualisation for military applications...

  6. Holographic complexity and action growth in massive gravities

    Science.gov (United States)

    Pan, Wen-Jian; Huang, Yong-Chang

    2017-06-01

    In this paper, we investigate the growth rates of action for the anti-de Sitter black holes in massive-Einstein gravity models and obtain the universal behaviors of the growth rates of action (the rates of holographic complexity) within the "Wheeler-DeWitt" (WDW) patch at the late limit. Furthermore, we find that, for the static neutral cases, when the same mass of black holes is given, the computational speed of the neutral massive black hole is the same as its Einstein gravity counterpart, which is independent with the effect of the graviton mass terms; nevertheless, for the static charged cases, when the same mass and charge parameters of black holes are given, the growth rates of action for the massive charged black holes are always superior to the growth rates of action without graviton mass terms, which directly shows that the massive charged black holes as computers on the computational speeds are faster than their Einstein gravity counterparts.

  7. Phase transitions of black holes in massive gravity

    CERN Document Server

    Fernando, Sharmanthie

    2016-01-01

    In this paper we have studied thermodynamics of a black hole in massive gravity in the canonical ensemble. The massive gravity theory in consideration here has a massive graviton due to Lorentz symmetry breaking. The black hole studied here has a scalar charge due to the massive graviton and is asymptotically anti-de Sitter. We have computed various thermodynamical quantities such as temperature, specific heat and free energy. Both the local and global stability of the black hole are studied by observing the behavior of the specific heat and the free energy. We have observed that there is a first order phase transition between small and large black hole for a certain range of the scalar charge. This phase transition is similar to the liquid/gas phase transition at constant temperature for a Van der Waals fluid. The coexistence curves for the small and large black hole branches are also discussed in detail.

  8. Massive Axial Gauge in the Exact Renormalization Group Approach

    Science.gov (United States)

    Panza, P.; Soldati, R.

    The Exact Renormalization Group (ERG) approach to massive gauge theories in the axial gauge is studied and the smoothness of the massless limit is analysed for a formally gauge invariant quantity such as the Euclidean Wilson loop.

  9. A case of massive hemoptysis following transesophageal echocardiogram

    Directory of Open Access Journals (Sweden)

    Sean J. Callahan

    2017-01-01

    Conclusions: Tracheal trauma is not a described complication of TEE, but clinicians should be mindful of this possible complication in patients receiving anticoagulation. Typical management for massive hemoptysis was successful in this patient.

  10. Video and Course Context Discussion on Massive Open Online Courses

    DEFF Research Database (Denmark)

    Dubosson, Magali; Emad, Sabine; Broillet, Alexandra

    2014-01-01

    Video and Course Content Discussion on Massive Open Online Courses: An Exploratory Research—Magali Dubosson (HEG Fribourg), Sabine Emad (HEG Genève), Alexandra Broillet (University of Geneva and Webster University Geneva), Constance Kampf (Aarhus University, Denmark)...

  11. Massive cuts to science and medicine in Trump budget

    National Research Council Canada - National Science Library

    Roger Collier

    2017-01-01

    The budget proposed by United States President Donald Trump calls for "massive cuts" to spending on medical and scientific research, public health and disease-prevention programs, and health insurance...

  12. Massively multiplayer online games (MMOs) in the new media classroom

    National Research Council Canada - National Science Library

    Aaron Delwiche

    2006-01-01

    .... Several scholars have suggested that massively multiplayer online games (MMOs) such as Everquest and Second Life have educational potential, but we have little data about what happens when such tools are introduced in the classroom...

  13. Massive to gauge field reduction and gravitational wave zone information

    CERN Document Server

    Deser, S

    2016-01-01

    We show explicitly that massive, Abelian, vector, just like (properly defined) massive tensor, fields limit smoothly to their massless, gauge, versions: they emit only maximal helicity radiation and mediate Coulomb and (special relativistic) Newtonian, forces between their (conserved) sources. Our main motivation, though, is to show that the recent gravitational wave detection probably cannot directly rule out very long-range gravity: Even though the waves were emitted in a strong field regime, their being detected in the weak field wave zone means the above equivalences apply. There remains the, not unlikely, possibility that no strong field generation of radiation in massive models can reproduce the observed ring-down patterns. Separately, the smooth linear limiting behaviors show that the discontinuity lies not in the mass alone, but rather in Abelian versus non-Abelian, Yang-Mills and General Relativity, regimes, whose respective massive versions are known to be non-physical.

  14. CERN's search for God (Particles) drives massive storage needs

    CERN Multimedia

    McLaughlin, Laurianne

    2007-01-01

    One of the grisliest problems is finding storage for the massive amounts of data derived from its four high-profile physics experiments making use of the institute's large hadron collider (LHC). (1,5 page)

  15. [Massive fecal impaction in a patient with osteogenesis imperfecta].

    Science.gov (United States)

    Bujanda, L; Beguiristain, A; Villar, J M; Medrano, M A; Arana, J; Alvarez-Caperochipi, J; Arenas, J I

    1994-05-01

    The case of a 22 year old male with massive faecal impaction and anorectal mechanical stenosis caused by multiples bone fractures and pelvic deformities secondary to imperfect osteogenesis is reported. The patient was treated with subtotal colectomy and permanent colostomy.

  16. Experimental free-space optical network for massively parallel computers.

    Science.gov (United States)

    Araki, S; Kajita, M; Kasahara, K; Kubota, K; Kurihara, K; Redmond, I; Schenfeld, E; Suzaki, T

    1996-03-10

    A free-space optical interconnection scheme is described for massively parallel processors based on the interconnection-cached network architecture. The optical network operates in a circuit-switching mode. Combined with a packet-switching operation among the circuit-switched optical channels, a high-bandwidth, low-latency network for massively parallel processing results. The design and assembly of a 64-channel experimental prototype is discussed, and operational results are presented.

  17. Quark–hadron phase transition in massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Atazadeh, K., E-mail: atazadeh@azaruniv.ac.ir

    2016-11-15

    We study the quark–hadron phase transition in the framework of massive gravity. We show that the modification of the FRW cosmological equations leads to the quark–hadron phase transition in the early massive Universe. Using numerical analysis, we consider that a phase transition based on the chiral symmetry breaking after the electroweak transition, occurred at approximately 10 μs after the Big Bang to convert a plasma of free quarks and gluons into hadrons.

  18. Massive gastrointestinal bleed due to multiple gastric neuroendocrine tumors

    Directory of Open Access Journals (Sweden)

    Vishal Sharma

    2015-01-01

    Full Text Available Gastric neuroendocrine tumors (G-NETs are uncommon lesions which are usually diagnosed on histological evaluation of gastric polyps. These may occur sporadically or due to hypergastrinemia in the setting of atrophic gastritis or Zollinger-Ellison Syndrome. Large lesions may ulcerate and result in gastrointestinal bleeding. However, massive gastrointestinal bleeding is rare in patients with NETs. We report a 60-year-old lady who presented with massive gastrointestinal bleeding due to multiple G-NETs.

  19. Experimental and clinical observations on massive suprachoroidal hemorrhage.

    OpenAIRE

    Lakhanpal, V

    1993-01-01

    We have been able to create a reproducible experimental model of nonexpulsive massive suprachoroidal hemorrhage in a rabbit eye. Massive suprachoroidal hemorrhage was demonstrated on echography and confirmed on histopathologic examination in all eyes. The natural course of the disease suggests that there is very little change in the size of the choroidal detachment in the first 7 days. Maximum liquefaction of the suprachoroidal hemorrhage clot was seen to occur between 7 and 14 days. However,...

  20. Massive basketball diagram for a thermal scalar field theory

    Science.gov (United States)

    Andersen, Jens O.; Braaten, Eric; Strickland, Michael

    2000-08-01

    The ``basketball diagram'' is a three-loop vacuum diagram for a scalar field theory that cannot be expressed in terms of one-loop diagrams. We calculate this diagram for a massive scalar field at nonzero temperature, reducing it to expressions involving three-dimensional integrals that can be easily evaluated numerically. We use this result to calculate the free energy for a massive scalar field with a φ4 interaction to three-loop order.

  1. Dietary management of the patient with massive enterectomy.

    Science.gov (United States)

    Gillanders, L; Maher, K; Schroeder, D; Stokes, M A; Hill, G L

    1990-07-11

    We present two cases who required massive enterectomy and who represent different points in the spectrum of this disease. We discuss their management from a nutritional stand-point and show details of energy uptake and expenditure for one of our patients. This describes our approach to this problem, and we hope it will be of use to others when dealing with patients following massive enterectomy.

  2. Duality and Confinement in Massive Antisymmetric Tensor Gauge Theories

    CERN Document Server

    Diamantini, M Cristina

    2001-01-01

    We extend the duality between massive and topologically massive antisymmetric tensor gauge theories in arbitrary space-time dimensions to include topological defects. We show explicitly that the condensation of these defects leads, in 4 dimensions, to confinement of electric strings in the two dual models. The dual phase, in which magnetic strings are confined is absent. The presence of the confinement phase explicitely found in the 4-dimensional case, is generalized, using duality arguments, to arbitrary space-time dimensions.

  3. Observations of Bright Massive Stars Using Small Size Telescopes

    Science.gov (United States)

    Beradze, Sopia; Kochiashvili, Nino

    2017-11-01

    The size of a telescope determines goals and objects of observations. During the latest decades it becomes more and more difficult to get photometric data of bright stars because most of telescopes of small sizes do not operate already. But there are rather interesting questions connected to the properties and evolution ties between different types of massive stars. Multi-wavelength photometric data are needed for solution of some of them. We are presenting our observational plans of bright Massive X-ray binaries, WR and LBV stars using a small size telescope. All these stars, which are presented in the poster are observational targets of Sopia Beradze's future PhD thesis. We already have got very interesting results on the reddening and possible future eruption of the massive hypergiant star P Cygni. Therefore, we decided to choose some additional interesting massive stars of different type for future observations. All Massive stars play an important role in the chemical evolution of galaxies because of they have very high mass loss - up to 10-4M⊙/a year. Our targets are on different evolutionary stages and three of them are the members of massive binaries. We plan to do UBVRI photometric observations of these stars using the 48 cm Cassegrain telescope of the Abastumani Astrophisical Observatory.

  4. Eta Carinae in the Context of the Most Massive Stars

    Science.gov (United States)

    Gull, Theodore R.; Damineli, Augusto

    2009-01-01

    Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know it to be a massive binary system with a 5.54-year period. In January 2009, Car underwent one of its periodic low-states, associated with periastron passage of the two massive stars. This event was monitored by an intensive multi-wavelength campaign ranging from -rays to radio. A large amount of data was collected to test a number of evolving models including 3-D models of the massive interacting winds. August 2009 was an excellent time for observers and theorists to come together and review the accumulated studies, as have occurred in four meetings since 1998 devoted to Eta Car. Indeed, Car behaved both predictably and unpredictably during this most recent periastron, spurring timely discussions. Coincidently, WR140 also passed through periastron in early 2009. It, too, is a intensively studied massive interacting binary. Comparison of its properties, as well as the properties of other massive stars, with those of Eta Car is very instructive. These well-known examples of evolved massive binary systems provide many clues as to the fate of the most massive stars. What are the effects of the interacting winds, of individual stellar rotation, and of the circumstellar material on what we see as hypernovae/supernovae? We hope to learn. Topics discussed in this 1.5 day Joint Discussion were: Car: the 2009.0 event: Monitoring campaigns in X-rays, optical, radio, interferometry WR140 and HD5980: similarities and differences to Car LBVs and Eta Carinae: What is the relationship? Massive binary systems, wind interactions and 3-D modeling Shapes of the Homunculus & Little Homunculus: what do we learn about mass ejection? Massive stars: the connection to supernovae, hypernovae and gamma ray bursters Where do we go from here? (future

  5. Most Massive Globular Cluster in Our Galaxy

    Science.gov (United States)

    1994-05-01

    Far down in the southern sky, in the constellation of Centaurus, a diffuse spot of light can be perceived with the unaided eye. It may be unimpressive, but when seen through a telescope, it turns out to be a beautiful, dense cluster of innumerable stars [1]. Omega Centauri, as this object is called, is the brightest of its type in the sky. We refer to it as a "globular cluster", due to its symmetric form. It belongs to our Milky Way galaxy and astrophysical investigations have shown that it is located at a distance of about 16,500 light-years (1 light-year = 9,460,000,000,000 km). Nobody knows for sure how many individual stars it contains, but recent estimates run into the millions. Most of these stars are more than 10,000 million years old and it is generally agreed that Omega Centauri has a similar age. Measurements of its motion indicate that Omega Centauri plows through the Milky Way in an elongated orbit. It is not easy to understand how it has managed to keep its stars together during such an extended period. MEASURING STELLAR VELOCITIES IN OMEGA CENTAURI A group of astronomers [2] have recently carried through a major investigation of Omega Centauri. After many nights of observations at the ESO La Silla observatory, they now conclude that not only is this globular cluster the brightest, it is indeed by far the most massive known in the Milky Way. The very time-consuming observations were made during numerous observing sessions over a period of no less than 13 years (1981-1993), with the photoelectric spectrometer CORAVEL mounted on the 1.5-m Danish telescope at La Silla. The CORAVEL instrument (COrelation RAdial VELocities) was built in a joint effort between the Geneva (Switzerland) and Marseilles (France) observatories. It functions according to the cross-correlation technique, by means of which the spectrum of the observed star is compared with a "standard stellar spectrum" [3]. HOW HEAVY IS OMEGA CENTAURI? In the present study, a total of 1701

  6. The ATLASGAL survey: The sample of young massive cluster progenitors

    Science.gov (United States)

    Csengeri, T.; Bontemps, S.; Wyrowski, F.; Megeath, S. T.; Motte, F.; Sanna, A.; Wienen, M.; Menten, K. M.

    2017-05-01

    Context. The progenitors of high-mass stars and clusters are still challenging to recognise. Only unbiased surveys, sensitive to compact regions of high dust column density, can unambiguously reveal such a small population of particularly massive and cold clumps. Aims: Here we use the ATLASGAL survey to identify a sample of candidate progenitors of massive clusters in the inner Galaxy. Methods: We characterise a flux limited sample of compact sources selected from the ATLASGAL survey. Sensitive mid-infrared data at 21-24μm from the WISE and MIPSGAL surveys were explored to search for embedded objects, and complementary spectroscopic data were used to investigate their stability and their star formation activity. Results: We identify an unbiased sample of infrared-quiet massive clumps in the Galaxy that potentially represent the earliest stages of massive cluster formation. An important fraction of this sample consists of sources that have not been studied in detail before. We first find that clumps hosting more evolved embedded objects and infrared-quiet clumps exhibit similar physical properties in terms of mass and size, suggesting that the sources are not only capable of forming high-mass stars, but likely also follow a single evolutionary track leading to the formation of massive clusters. The majority of the clumps are likely not in virial-equilibrium, suggesting collapse on the clump scale. Conclusions: We identify the precursors of the most massive clusters in the Galaxy within our completeness limit, and argue that these objects are undergoing large-scale collapse. This is in line with the low number of infrared-quiet massive clumps and earlier findings that star formation, in particular for high-mass objects is a fast, dynamic process. We propose a scenario in which massive clumps start to fragment and collapse before their final mass is accumulated indicating that strong self-gravity and global collapse is needed to build up rich clusters and the most

  7. Cosmological stability bound in massive gravity and bigravity

    Science.gov (United States)

    Fasiello, Matteo; Tolley, Andrew J.

    2013-12-01

    We give a simple derivation of a cosmological bound on the graviton mass for spatially flat FRW solutions in massive gravity with an FRW reference metric and for bigravity theories. This bound comes from the requirement that the kinetic term of the helicity zero mode of the graviton is positive definite. The bound is dependent only on the parameters in the massive gravity potential and the Hubble expansion rate for the two metrics. We derive the decoupling limit of bigravity and FRW massive gravity, and use this to give an independent derivation of the cosmological bound. We recover our previous results that the tension between satisfying the Friedmann equation and the cosmological bound is sufficient to rule out all observationally relevant FRW solutions for massive gravity with an FRW reference metric. In contrast, in bigravity this tension is resolved due to different nature of the Vainshtein mechanism. We find that in bigravity theories there exists an FRW solution with late-time self-acceleration for which the kinetic terms for the helicity-2, helicity-1 and helicity-0 are generically nonzero and positive making this a compelling candidate for a model of cosmic acceleration. We confirm that the generalized bound is saturated for the candidate partially massless (bi)gravity theories but the existence of helicity-1/helicity-0 interactions implies the absence of the conjectured partially massless symmetry for both massive gravity and bigravity.

  8. Multimodality imaging findings of massive ovarian edema in children

    Energy Technology Data Exchange (ETDEWEB)

    Dahmoush, Hisham [Stanford University Medical Center, Department of Radiology, Neuroradiology Division, Stanford, CA (United States); Anupindi, Sudha A.; Chauvin, Nancy A. [University of Pennsylvania, The Children' s Hospital of Philadelphia, Department of Radiology, Perelman School of Medicine, Philadelphia, PA (United States); Pawel, Bruce R. [University of Pennsylvania, The Children' s Hospital of Philadelphia, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, Philadelphia, PA (United States)

    2017-05-15

    Massive ovarian edema is a rare benign condition that predominantly affects childbearing women as well as preadolescent girls. It is thought to result from intermittent or partial torsion of the ovary compromising the venous and lymphatic drainage but with preserved arterial supply. The clinical features of massive ovarian edema are nonspecific and can simulate tumors, leading to unnecessary oophorectomy. To demonstrate imaging features that should alert radiologists to consider the diagnosis of massive ovarian edema preoperatively so that fertility-sparing surgery may be considered. We identified five girls diagnosed with massive ovarian edema at pathology. Presenting symptoms, sidedness, imaging appearance, preoperative diagnosis, and operative and histopathological findings were reviewed. Age range was 9.6-14.3 years (mean age: 12.5 years). Common imaging findings included ovarian enlargement with edema of the stroma, peripherally placed follicles, isointense signal on T1-W MRI and markedly hyperintense signal on T2-W MRI, preservation of color Doppler flow by US, and CT Hounsfield units below 40. The uterus was deviated to the affected side in all patients. Two of the five patients had small to moderate amounts of free pelvic fluid. Mean ovarian volume on imaging was 560 mL (range: 108-1,361 mL). While the clinical presentation of massive ovarian edema is nonspecific, an enlarged ovary with stromal edema, peripherally placed follicles and preservation of blood flow may be suggestive and wedge biopsy should be considered intraoperatively to avoid unnecessary removal of the ovary. (orig.)

  9. Massive MIMO meets small cell backhaul and cooperation

    CERN Document Server

    Yang, Howard H

    2017-01-01

    This brief explores the utilization of large antenna arrays in massive multiple-input-multiple-output (MIMO) for both interference suppression, where it can improve cell-edge user rates, and for wireless backhaul in small cell networks, where macro base stations can forward data to small access points in an energy efficient way. Massive MIMO is deemed as a critical technology for next generation wireless technology. By deploying an antenna array that has active elements in excess of the number of users, massive MIMO not only provides tremendous diversity gain but also powers new aspects for network design to improve performance. This brief investigates a better utilization of the excessive spatial dimensions to improve network performance. It combines random matrix theory and stochastic geometry to develop an analytical framework that accounts for all the key features of a network, including number of antenna array, base station density, inter-cell interference, random base station deployment, and network tra...

  10. Massive Stars: From the VLT to the ELT

    Science.gov (United States)

    Evans, C. J.

    2008-08-01

    New facilities and technologies have advanced our understanding of massive stars significantly over the past 30 years. Here I introduce a new large survey of massive stars using VLT-FLAMES, noting the target fields and observed binary fractions. These data have been used for the first empirical test of the metallicity dependence of the intensity of stellar winds, finding good agreement with theory - an important result for the evolutionary models that are used to interpret distant clusters, starbursts, and star-forming galaxies. Looking ahead, plans for future Extremely Large Telescopes (ELTs) are now undergoing significant development, and offer the exciting prospect of observing spatially-resolved massive stars well beyond the Local Group.

  11. Cosmological viability of theories with massive spin-2 fields

    Energy Technology Data Exchange (ETDEWEB)

    Koennig, Frank

    2017-03-30

    Theories of spin-2 fields take on a particular role in modern physics. They do not only describe the mediation of gravity, the only theory of fundamental interactions of which no quantum field theoretical description exists, it furthermore was thought that they necessarily predict massless gauge bosons. Just recently, a consistent theory of a massive graviton was constructed and, subsequently, generalized to a bimetric theory of two interacting spin-2 fields. This thesis studies both the viability and consequences at cosmological scales in massive gravity as well as bimetric theories. We show that all consistent models that are free of gradient and ghost instabilities behave like the cosmological standard model, LCDM. In addition, we construct a new theory of massive gravity which is stable at both classical background and quantum level, even though it suffers from the Boulware-Deser ghost.

  12. The formation of massive star systems by accretion.

    Science.gov (United States)

    Krumholz, Mark R; Klein, Richard I; McKee, Christopher F; Offner, Stella S R; Cunningham, Andrew J

    2009-02-06

    Massive stars produce so much light that the radiation pressure they exert on the gas and dust around them is stronger than their gravitational attraction, a condition that has long been expected to prevent them from growing by accretion. We present three-dimensional radiation-hydrodynamic simulations of the collapse of a massive prestellar core and find that radiation pressure does not halt accretion. Instead, gravitational and Rayleigh-Taylor instabilities channel gas onto the star system through nonaxisymmetric disks and filaments that self-shield against radiation while allowing radiation to escape through optically thin bubbles. Gravitational instabilities cause the disk to fragment and form a massive companion to the primary star. Radiation pressure does not limit stellar masses, but the instabilities that allow accretion to continue lead to small multiple systems.

  13. Radioactive and kinematic tracers of feedback from massive stars

    Directory of Open Access Journals (Sweden)

    Voss R.

    2012-02-01

    Full Text Available The mixing of ejecta from young stars into the interstellar medium is an important process in the interplay between star formation and galaxy evolution. A unique window into these processes is provided by the radioactive isotopes 26Al, traced by its γ-ray decay lines at 1.8 MeV. With a mean lifetime of ∼ 1 Myr it is a long-term tracer of nucleosynthesis for massive stars. Our population synthesis code models the ejection of 26Al, together with the 60Fe, the kinetic energy and UV radiation for a population of massive stars. We have applied the code to study the nearby Orion region and the more massive Carina region and found good agreement with observational constraints.

  14. Role of Massive Stars in the Evolution of Primitive Galaxies

    Science.gov (United States)

    Heap, Sara

    2012-01-01

    An important factor controlling galaxy evolution is feedback from massive stars. It is believed that the nature and intensity of stellar feedback changes as a function of galaxy mass and metallicity. At low mass and metallicity, feedback from massive stars is mainly in the form of photoionizing radiation. At higher mass and metallicity, it is in stellar winds. IZw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass greater than 10(exp 9)Msun, strong photoionizing radiation, no galactic outflow, and very low metallicity,log(O/H)+12=7.2. We will describe the properties of massive stars and their role in the evolution of IZw 18, based on analysis of ultraviolet images and spectra obtained with HST.

  15. What can distant galaxies teach us about massive stars?

    Science.gov (United States)

    Stanway, Elizabeth R.

    2017-11-01

    Observations of star-forming galaxies in the distant Universe (z > 2) are starting to confirm the importance of massive stars in shaping galaxy emission and evolution. Inevitably, these distant stellar populations are unresolved, and the limited data available must be interpreted in the context of stellar population synthesis models. With the imminent launch of JWST and the prospect of spectral observations of galaxies within a gigayear of the Big Bang, the uncertainties in modelling of massive stars are becoming increasingly important to our interpretation of the high redshift Universe. In turn, these observations of distant stellar populations will provide ever stronger tests against which to gauge the success of, and flaws in, current massive star models.

  16. International Conference on Instability and Control of Massively Separated Flows

    CERN Document Server

    Soria, Julio

    2015-01-01

    This book contains the outcome of the international meeting on instability, control and noise generated by massive flow separation that was organized at the Monash Center, in Prato, Italy, September 4-6, 2013. The meeting served as the final review of the EU-FP7 Instability and Control of Massively Separated Flows Marie Curie travel grant and was supported by the European Office of Aerospace Research and Development. Fifty leading specialists from twelve countries reviewed the progress made since the 50s of the last century and discussed modern analysis techniques, advanced experimental flow diagnostics, and recent developments in active flow control techniques from the incompressible to the hypersonic regime. Applications involving massive flow separation and associated instability and noise generation mechanisms of interest to the aeronautical, naval and automotive industries have been addressed from a theoretical, numerical or experimental point of view, making this book a unique source containing the stat...

  17. Magnetic resonance imaging of massive bone allografts with histologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeffner, E.G. [Dept. of Radiology, Wayne State Univ. School of Medicine, Detroit, MI (United States); Soulen, R.L. [Dept. of Radiology, Wayne State Univ. School of Medicine, Detroit, MI (United States); Ryan, J.R. [Dept. of Orthopaedic Surgery, Wayne State Univ. School of Medicine, Detroit, MI (United States); Qureshi, F. [Dept. of Pathology, Wayne State Univ. School of Medicine, Detroit, MI (United States)

    1996-02-01

    The objective of this study was to better understand the MRI appearance of massive bone allografts. The MRI findings of three massive bone allografts imaged in vivo were correlated with the histologic findings following removal of the allografts. A fourth allograft, never implanted, was imaged and evaluated histologically. Allografts were placed for the treatment of primary or recurrent osteosarcoma. The in-vivo allografts have a heterogeneous appearance on MRI which we attribute to the revascularization process. Fibrovascular connective tissue grows into the graft in a patchy, focal fashion, down the medullary canal from the graft-host junction and adjacent to the periosteum. The marrow spaces are initially devoid of normal cellular elements and occupied by fat and gelatinous material. This normal postoperative appearance of massive bone allografts must not be interpreted as recurrent neoplasm or infection in the allograft. Recognition of these complications rests on features outside the marrow. (orig./MG)

  18. Massive stars in the Sagittarius Dwarf Irregular Galaxy

    Science.gov (United States)

    Garcia, Miriam

    2018-02-01

    Low metallicity massive stars hold the key to interpret numerous processes in the past Universe including re-ionization, starburst galaxies, high-redshift supernovae, and γ-ray bursts. The Sagittarius Dwarf Irregular Galaxy [SagDIG, 12+log(O/H) = 7.37] represents an important landmark in the quest for analogues accessible with 10-m class telescopes. This Letter presents low-resolution spectroscopy executed with the Gran Telescopio Canarias that confirms that SagDIG hosts massive stars. The observations unveiled three OBA-type stars and one red supergiant candidate. Pending confirmation from high-resolution follow-up studies, these could be the most metal-poor massive stars of the Local Group.

  19. Light element production by low energy nuclei from massive stars

    Science.gov (United States)

    Vangioni-Flam, E.; Casse, M.; Ramaty, R.

    1997-01-01

    The Orion complex is a source of gamma rays attributed to the de-excitation of fast carbon and oxygen nuclei excited through interactions with ambient hydrogen and helium. This has consequences for the production and evolution of light isotopes in the Galaxy, as massive stars appear as prolific sources of C-O rich low energy nuclei. The different stages of massive star evolution are considered in relation to the acceleration of nuclei to moderate energies. It is concluded that the low energy nuclear component originating from massive stars plays a larger role than the usual Galactic cosmic rays in shaping the evolution of Li-6, Be-9, B-10 and B-11, especially in the early Galactic evolution. The enhancement of the B-11/B-10 ratio observed in meteorites and in the interstellar medium is attributed to the interaction of low energy carbon nuclei with ambient H and to a lesser degree, to neutrino spallation.

  20. Distributed Learning over Massive XML Documents in ELM Feature Space

    Directory of Open Access Journals (Sweden)

    Xin Bi

    2015-01-01

    Full Text Available With the exponentially increasing volume of XML data, centralized learning solutions are unable to meet the requirements of mining applications with massive training samples. In this paper, a solution to distributed learning over massive XML documents is proposed, which provides distributed conversion of XML documents into representation model in parallel based on MapReduce and a distributed learning component based on Extreme Learning Machine for mining tasks of classification or clustering. Within this framework, training samples are converted from raw XML datasets with better efficiency and information representation ability and taken to distributed learning algorithms in Extreme Learning Machine (ELM feature space. Extensive experiments are conducted on massive XML documents datasets to verify the effectiveness and efficiency for both classification and clustering applications.

  1. Multiuser Beamforming with Limited Feedback for FDD Massive MIMO Systems

    Directory of Open Access Journals (Sweden)

    Senyao Zheng

    2016-01-01

    Full Text Available This paper discusses the multiuser beamforming in FDD massive MIMO systems. It first introduces the feature of FDD massive MIMO systems to implement multiuser beamforming schemes. After that, considering the realistic implementation of multiuser beamforming scheme in FDD massive MIMO systems, it introduces the knowledge of channel quantization. In the main part of the paper, we introduce two traditional multiuser beamforming schemes and analyse their merits and demerits. Based on these, we propose a novel multiuser beamforming scheme to flexibly combine the merits of the traditional beamforming schemes. In the final part of the paper, we give some simulation results to compare the beamforming schemes mentioned in the paper. These simulation results show the superiority of the proposed beamforming scheme.

  2. A non-perturbative study of massive gauge theories

    DEFF Research Database (Denmark)

    Della Morte, Michele; Hernandez, Pilar

    2013-01-01

    We consider a non-perturbative formulation of an SU(2) massive gauge theory on a space-time lattice, which is also a discretised gauged non-linear chiral model. The lattice model is shown to have an exactly conserved global SU(2) symmetry. If a scaling region for the lattice model exists...... and the lightest degrees of freedom are spin one vector particles with the same quantum numbers as the conserved current, we argue that the most general effective theory describing their low-energy dynamics must be a massive gauge theory. We present results of a exploratory numerical simulation of the model...

  3. Black hole conserved charges in Generalized Minimal Massive Gravity

    Directory of Open Access Journals (Sweden)

    M.R. Setare

    2015-05-01

    Full Text Available In this paper we construct mass, angular momentum and entropy of black hole solution of Generalized Minimal Massive Gravity (GMMG in asymptotically Anti-de Sitter (AdS spacetimes. The Generalized Minimal Massive Gravity theory is realized by adding the CS deformation term, the higher derivative deformation term, and an extra term to pure Einstein gravity with a negative cosmological constant. We apply our result for conserved charge Qμ(ξ¯ to the rotating BTZ black hole solution of GMMG, and find energy, angular momentum and entropy. Then we show that our results for these quantities are consistent with the first law of black hole thermodynamics.

  4. Anaesthetic management of a child with massive extracranial arteriovenous malformation

    Directory of Open Access Journals (Sweden)

    Faisal Shamim

    2012-01-01

    Full Text Available Vascular tumors affect the head and neck commonly but arteriovenous malformations are rare. Vascular malformations are often present at birth and grow with the patient, usually only becoming significant later in childhood. Embolization has been the mainstay of treatment in massive and complex arteriovenous malformations. We present a case of massive extracranial arteriovenous malformation in a 7-year-old boy causing significant workload on right heart and respiratory distress. The management of angioembolization under general anaesthesia and anaesthetic concerns are presented.

  5. QUALITY OF LIFE IN PATIENTS AFTER MASSIVE PULMONARY EMBOLISM

    Directory of Open Access Journals (Sweden)

    Dragan Kovačić

    2004-04-01

    Full Text Available Background. Pulmonary embolism is a disease, which has a 30% mortality if untreated, while an early diagnosis and treatment lowers it to 2–8%. Health related quality of life (HRQL of patients who survived massive pulmonary embolism is unknown in published literature. In our research we tried to apply experience of foreign experts in estimation of quality of life in some other diseases to the field of massive pulmonary embolism.Patients and methods. Eighteen patients with shock or hypotension due to massive pulmonary embolism, treated with thrombolysis, between July 1993 and November 2000, were prospectively included in the study. Control group included 18 gender and age matched persons. There were no significant differences regarding demographic data between the groups. The HRQL and aerobic capacity of patients and control group were tested with short questions and questionnaires (Veterans brief, self administered questionnaire (VSAQ, EuroQuality questionnaire (EQ, Living with heart failure questionnaire (LlhHF. With LlhHF physical (F-LlhHF and emotional (E-LlhHF HRQL was assessed at hospitalization and 12 months later.Results. One year after massive pulmonary embolism aerobic capacity (–9.5%, p < 0.017 and HRQL (EQ (–34.5%, F-LlhHF (–85.4%, E-LlhHF (–48.7% decreased in massive pulmonary embolism group compared to aerobic capacity 6 months before massive pulmonary embolism and HRQL. Heart rate before thrombolysis correlated with aerobic capacity (r = 0.627, p < 0.01, EQ (r = 0.479, p < 0.01 and F-LlhHF (r = 0.479, p = 0.04 1 year after massive pulmonary embolism. Total pulmonary resistance at 12 hours after start of treatment correlated with aerobic capacity at 1 year (r = 0.354, p < 0.01.With short question (»Did you need any help in everyday activities in last 2 weeks?« we successfully separated patients with decreased HRQL in EQ (74.3 ± 20.8 vs. 24.5 ± 20.7, p < 0.001 and F-LlhHF (21.7 ± 6.7 vs. 32.8 ± 4.3, p < 0.01, but we

  6. Bilateral Massive Ovarian Luteinized Follicular Cysts of a Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Li-Song Teng

    2010-12-01

    Full Text Available We report a case of rare bilateral massive ovarian luteinized follicular cysts in a twin pregnancy. A 28-year-old, gravida 1, para 0, abortus 0 woman was incidentally found to have bilateral massive ovarian cysts (left side, 12 × 10 × 8 cm; right side, 15 × 10 × 6 cm during the cesarean delivery of a twin pregnancy at 36 weeks of gestation. After 1,950-g and 2,350-g female babies were delivered in good condition, the patient received bilateral oophorectomy. Subsequent histopathology led to the diagnosis of giant bilateral ovarian luteinized follicular cysts.

  7. Bilateral Massive Ovarian Luteinized Follicular Cysts of a Twin Pregnancy

    OpenAIRE

    Li-Song Teng; Ke-Tao Jin; Kui-Feng He; Tie-Ming Zhu; Fan Zhao; Zhi-Gang Jin

    2010-01-01

    We report a case of rare bilateral massive ovarian luteinized follicular cysts in a twin pregnancy. A 28-year-old, gravida 1, para 0, abortus 0 woman was incidentally found to have bilateral massive ovarian cysts (left side, 12 × 10 × 8 cm; right side, 15 × 10 × 6 cm) during the cesarean delivery of a twin pregnancy at 36 weeks of gestation. After 1,950-g and 2,350-g female babies were delivered in good condition, the patient received bilateral oophorectomy. Subsequent histopathology led to t...

  8. A Visualization of Null Geodesics for the Bonnor Massive Dipole

    CERN Document Server

    Oliva-Mercado, Guillermo Andree; Cordero-García, Iván; Frutos-Alfaro, Francisco

    2015-01-01

    In this work we simulate null geodesics for the Bonnor massive dipole metric by implementing a symbolic-numerical algorithm in Sage and Python. This program is also capable of visualizing in 3D, in principle, the geodesics for any given metric. Geodesics are launched from a common point, collectively forming a cone of light beams, simulating a solid-angle section of a point source in front of a massive object with a magnetic field. Parallel light beams also were considered, and their bending due to the curvature of the space-time was simulated.

  9. A visualization of null geodesics for the bonnor massive dipole

    Directory of Open Access Journals (Sweden)

    G. Andree Oliva Mercado

    2015-08-01

    Full Text Available In this work we simulate null geodesics for the Bonnor massive dipole metric by implementing a symbolic-numerical algorithm in Sage and Python. This program is also capable of visualizing in 3D, in principle, the geodesics for any given metric. Geodesics are launched from a common point, collectively forming a cone of light beams, simulating a solid-angle section of a point source in front of a massive object with a magnetic field. Parallel light beams also were considered, and their bending due to the curvature of the space-time was simulated.

  10. Massive retinal gliosis: An unusual case with immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Sanjay D Deshmukh

    2011-01-01

    Full Text Available Massive retinal gliosis (MRG is a rare, benign intraocular condition that results from the proliferation of well-differentiated glial cells. Immunohistochemically, these cells show positivity for glial fibrillary acid protein (GFAP, neuron specific enolase (NSE, and S-100 protein. We encountered a case of a 45-year-old female with loss of vision in the left eye. She had a history of trauma to that eye two years ago. Enucleation was carried out, because malignancy was suspected due to retinal calcification. On the basis of light microscopy and immunohistochemistry (IHC performed on the enucleated eye, it was diagnosed as massive retinal gliosis.

  11. Parallel Spatiotemporal Spectral Clustering with Massive Trajectory Data

    Science.gov (United States)

    Gu, Y. Z.; Qin, K.; Chen, Y. X.; Yue, M. X.; Guo, T.

    2017-09-01

    Massive trajectory data contains wealth useful information and knowledge. Spectral clustering, which has been shown to be effective in finding clusters, becomes an important clustering approaches in the trajectory data mining. However, the traditional spectral clustering lacks the temporal expansion on the algorithm and limited in its applicability to large-scale problems due to its high computational complexity. This paper presents a parallel spatiotemporal spectral clustering based on multiple acceleration solutions to make the algorithm more effective and efficient, the performance is proved due to the experiment carried out on the massive taxi trajectory dataset in Wuhan city, China.

  12. Blood Transfusion Strategies for Hemostatic Resuscitation in Massive Trauma.

    Science.gov (United States)

    McGrath, Caroline

    2016-03-01

    Massive transfusion practices were transformed during the 1970s without solid evidence supporting the use of component therapy. A manual literature search was performed for all references to the lethal triad, acute or early coagulopathy of trauma, fresh whole blood, and component transfusion therapy in massive trauma, and damage control resuscitation. Data from recent wars suggest traditional component therapy causes a nonhemostatic resuscitation worsening the propagation of the lethal triad hastening death. These same studies also indicate the advantage of fresh whole blood over component therapy even when administered in a 1:1:1 replacement ratio. Published by Elsevier Inc.

  13. The Stripe 82 Massive Galaxy Project. III. A Lack of Growth among Massive Galaxies

    Science.gov (United States)

    Bundy, Kevin; Leauthaud, Alexie; Saito, Shun; Maraston, Claudia; Wake, David A.; Thomas, Daniel

    2017-12-01

    The average stellar mass (M *) of high-mass galaxies ({log}{M}* /{M}⊙ > 11.5) is expected to grow by ˜30% since z˜ 1, largely through ongoing mergers that are also invoked to explain the observed increase in galaxy sizes. Direct evidence for the corresponding growth in stellar mass has been elusive, however, in part because the volumes sampled by previous redshift surveys have been too small to yield reliable statistics. In this work, we make use of the Stripe 82 Massive Galaxy Catalog (S82-MGC) to build a mass-limited sample of 41,770 galaxies ({log}{M}* /{M}⊙ > 11.2) with optical-to-near-IR photometry and a large fraction (>55%) of spectroscopic redshifts. Our sample spans 139 deg2, significantly larger than most previous efforts. After accounting for a number of potential systematic errors, including the effects of M * scatter, we measure galaxy stellar mass functions over 0.3history assumed for M * estimates, although our inability to characterize low-surface-brightness outskirts may be the most important limitation of our study. Even among these high-mass galaxies, we find evidence for differential evolution when splitting the sample by recent SF activity. While low-SF systems appear to become completely passive, we find a mostly subdominant population of galaxies with residual, but low rates of SF (˜1 M ⊙ yr-1) whose number density does not evolve. Interestingly, these galaxies become more prominent at higher M *, representing ˜10% of all galaxies at {10}12 {M}⊙ and perhaps dominating at even larger masses.

  14. Prediction of RNA base pairing probabilities on massively parallel computers.

    Science.gov (United States)

    Fekete, M; Hofacker, I L; Stadler, P F

    2000-01-01

    We present an implementation of McCaskill's algorithm for computing the base pair probabilities of an RNA molecule for massively parallel message passing architectures. The program can be used to routinely fold RNA sequences of more than 10,000 nucleotides. Applications to complete viral genomes are discussed.

  15. Fluorescent bands in massive corals record centuries of coastal rainfall

    Science.gov (United States)

    Isdale, Peter

    1984-08-01

    Massive coral colonies on the Great Barrier Reef grow outwards at 5-25 mm yr-1 (ref. 1). Skeletal density varies seasonally in all massive corals from the Great Barrier Reef and an exact temporal record of growth can be obtained by X-radiography of appropriately cut sections of the colony2,3. Environmental influences on coral growth have been described from such analyses4-6. This is the first report from the skeletons of massive corals of yellow green fluorescent bands which appear under long-wave UV light. Such fluorescence is confined to corals growing within 20 km of the shore and is not present in massive corals from mid- and outer shelf reefs of the central Great Barrier Reef region. The timing, width and intensity of the fluorescent bands correlate strongly with summer, monsoonal rainfall and coastal runoff. Large colonies, several centuries old, can provide long records of the strength and periodicity of terrestrial runoff to the tropical nearshore environment. Such records are potentially important to climatology, meteorology, agriculture, civil engineering and management of the Great Barrier Reef.

  16. Impulsive gravitational waves in general massive 3D gravity

    Science.gov (United States)

    Baykal, Ahmet; Dereli, Tekin

    2017-10-01

    Impulsive, nondiverging, Petrov-Segre type-N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter, and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms.

  17. NEW APPROACHES TO EFFICIENCY OF MASSIVE ONLINE COURSE

    Directory of Open Access Journals (Sweden)

    Liubov S. Lysitsina

    2014-09-01

    Full Text Available This paper is focused on efficiency of e-learning, in general, and massive online course in programming and information technology, in particular. Several innovative approaches and scenarios have been proposed, developed, implemented and verified by the authors, including 1 a new approach to organize and use automatic immediate feedback that significantly helps a learner to verify developed code and increases an efficiency of learning, 2 a new approach to construct learning interfaces – it is based on “develop a code – get a result – validate a code” technique, 3 three scenarios of visualization and verification of developed code, 4 a new multi-stage approach to solve complex programming assignments, 5 a new implementation of “perfectionism” game mechanics in a massive online course. Overall, due to implementation of proposed and developed approaches, the efficiency of massive online course has been considerably increased, particularly 1 the additional 27.9 % of students were able to complete successfully “Web design and development using HTML5 and CSS3” massive online course at ITMO University, and 2 based on feedback from 5588 students a “perfectionism” game mechanics noticeably improves students’ involvement into course activities and retention factor.

  18. The QCD form factor of massive quarks and applications

    Energy Technology Data Exchange (ETDEWEB)

    Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-11-15

    We review the electromagnetic form factor of heavy quarks with emphasis on the QCD radiative corrections at two-loop order in the perturbative expansion. We discuss important properties of the heavy-quark form factor such as its exponentiation in the high-energy limit and its role in QCD factorization theorems for massive n-parton amplitudes. (orig.)

  19. [Endomyocardial fibrosis with massive calcification of the left ventricle].

    Science.gov (United States)

    Trigo, Joana; Camacho, Ana; Gago, Paula; Candeias, Rui; Santos, Walter; Marques, Nuno; Matos, Pedro; Brandão, Victor; Gomes, Veloso

    2010-03-01

    Endomyocardial fibrosis is a rare disease, endemic in tropical countries. It is characterized by fibrosis of the endocardium that can extend to myocardium. Important calcification of the endocardium is rare with only a few cases reported in the literature. We report a case of endomyocardial fibrosis in a european caucasian patient, associated with massive calcification of left ventricle.

  20. MOOCocracy: The Learning Culture of Massive Open Online Courses

    Science.gov (United States)

    Loizzo, Jamie; Ertmer, Peggy A.

    2016-01-01

    Massive open online courses (MOOCs) are often examined and evaluated in terms of institutional cost, instructor prestige, number of students enrolled, and completion rates. MOOCs, which are connecting thousands of adult learners from diverse backgrounds, have yet to be viewed from a learning culture perspective. This research used virtual…

  1. Astronomy for Astronomical Numbers: A Worldwide Massive Open Online Class

    Science.gov (United States)

    Impey, Chris D.; Wenger, Matthew C.; Austin, Carmen L.

    2015-01-01

    Astronomy: State of the Art is a massive, open, online class (MOOC) offered through Udemy by an instructional team at the University of Arizona. With nearly 24,000 enrolled as of early 2015, it is the largest astronomy MOOC available. The astronomical numbers enrolled do not translate into a similar level of engagement. The content consists of 14…

  2. The place of interferometry in massive star multiplicity studies

    NARCIS (Netherlands)

    Sana, H.; Le Bouquin, J.-B.; Rivinius, T.; Curé, M.

    2010-01-01

    While it is well known that most massive stars are found to be part of binary or multiple systems, an accurate characterization of the statistical properties of these multiple objects is still lacking. In the present talk, we will review the current status of the field, emphasizing the need of using

  3. Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

    DEFF Research Database (Denmark)

    Peise, Jan; Kruse, I.; Lange, K.

    2016-01-01

    In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, as shown successfully...

  4. A New Framework for Massive Open Online Courses (MOOCs)

    Science.gov (United States)

    Schoenack, Lindsie

    2013-01-01

    The challenges that massive open online courses (MOOCs) bring to the learning arena spur adult educators to improve delivery. A framework for a new type of MOOC is presented to address some of the challenges presented by earlier models. This new MOOC, called a mesoMOOC, can bridge several challenges that hinder current effective delivery of MOOCs…

  5. Massive Open Online Librarianship: Emerging Practices in Response to MOOCs

    Science.gov (United States)

    Mune, Christina

    2015-01-01

    Massive Open Online Courses, or MOOCs, have recently emerged as a disruptive pedagogy gaining rapid momentum in higher education. In some states, proposed legislations would accredit MOOCs to provide college-credit courses in the name of cost saving, efficiency and access. While debates rage regarding the place of MOOCs in higher education, some…

  6. Auditing the Accessibility of Massive Open Online Courses (MOOCs).

    Science.gov (United States)

    Iniesto, Francisco; McAndrew, Patrick; Minocha, Shailey; Coughlan, Tim

    2017-01-01

    The outcome from the research being reported in this paper is the design of an accessibility audit to evaluate Massive Open Online Courses (MOOCs) for accessibility and to arrive at solutions and adaptations that can meet user needs. This accessibility audit includes expert-based heuristic evaluations and user-based evaluations of the MOOC platforms and individual courses.

  7. Metallicity dependence of envelope inflation in massive stars

    Czech Academy of Sciences Publication Activity Database

    Sanyal, D.; Langer, N.; Szécsi, Dorottya; Yoon, S.-C.; Grassitelli, L.

    2017-01-01

    Roč. 597, January (2017), A71/1-A71/16 E-ISSN 1432-0746 R&D Projects: GA ČR(CZ) GA14-02385S Institutional support: RVO:67985815 Keywords : stars evolution * stars massive * stars interiors Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.014, year: 2016

  8. Classical and quantum cosmology of minimal massive bigravity

    Energy Technology Data Exchange (ETDEWEB)

    Darabi, F., E-mail: f.darabi@azaruniv.edu; Mousavi, M., E-mail: mousavi@azaruniv.edu

    2016-10-10

    In a Friedmann–Robertson–Walker (FRW) space–time background we study the classical cosmological models in the context of recently proposed theory of nonlinear minimal massive bigravity. We show that in the presence of perfect fluid the classical field equations acquire contribution from the massive graviton as a cosmological term which is positive or negative depending on the dynamical competition between two scale factors of bigravity metrics. We obtain the classical field equations for flat and open universes in the ordinary and Schutz representation of perfect fluid. Focusing on the Schutz representation for flat universe, we find classical solutions exhibiting singularities at early universe with vacuum equation of state. Then, in the Schutz representation, we study the quantum cosmology for flat universe and derive the Schrodinger–Wheeler–DeWitt equation. We find its exact and wave packet solutions and discuss on their properties to show that the initial singularity in the classical solutions can be avoided by quantum cosmology. Similar to the study of Hartle–Hawking no-boundary proposal in the quantum cosmology of de Rham, Gabadadze and Tolley (dRGT) massive gravity, it turns out that the mass of graviton predicted by quantum cosmology of the minimal massive bigravity is large at early universe. This is in agreement with the fact that at early universe the cosmological constant should be large.

  9. Unexplained massive subdural haematoma in a newborn delivered ...

    African Journals Online (AJOL)

    Emergency Caesarean Section (EmC/S) carried out after failed attempts at vaginal delivery may also be complicated by symptomatic SDH but spontaneous symptomatic SDH complicating Elective Caesarean Section (ElC/S) is a rarity. We describe a case of massive SDH in a term baby delivered by Elective C/S in the ...

  10. Massive open online courses are relevant for postgraduate medical training

    DEFF Research Database (Denmark)

    Subhi, Yousif; Andresen, Kristoffer; Rolskov Bojsen, Signe

    2014-01-01

    INTRODUCTION: The CanMEDS framework describes seven roles in postgraduate training, but training and courses relevant to these roles can be limited. Massive open online courses (MOOCs) - free online courses in which anyone can participate, anywhere - may improve course participation. This study...

  11. Spontaneous gastric perforation in a neonate presenting with massive hydroperitoneum

    Energy Technology Data Exchange (ETDEWEB)

    Im, Soo Ah [Catholic University of Korea, Kangnam St. Mary' s Hospital, Seoul (Korea); Lim, Gye-Yeon; Hahn, Seong Tai [Catholic University of Korea, Department of Radiology, Seoul (Korea); St. Mary' s Hospital, College of Medicine, Seoul (Korea)

    2005-12-01

    We report the imaging findings in a case of neonatal spontaneous gastric perforation presenting as massive hydroperitoneum rather than pneumoperitoneum. Plain abdominal radiography showed a diffuse ground-glass opacity with paucity of bowel gas. Subsequent ultrasonography demonstrated numerous echogenic peritoneal fluid collections containing echogenic debris shown at surgery to be due to milk and bile. (orig.)

  12. The Evolution and Properties of Rotating Massive Star Populations

    Science.gov (United States)

    Choi, Jieun; Conroy, Charlie; Byler, Nell

    2017-04-01

    We investigate the integrated properties of massive (> 10 {M}⊙ ) rotating single-star stellar populations for a variety of initial rotation rates (v/{v}{crit}=0.0, 0.2, 0.4, 0.5, and 0.6). We couple the new MESA Isochrone and Stellar Tracks (MIST) models to the Flexible Stellar Population Synthesis (FSPS) package, extending the stellar population synthesis models to include the contributions from very massive stars (> 100 {M}⊙ ), which can be significant in the first ˜4 Myr after a starburst. These models predict ionizing luminosities that are consistent with recent observations of young nuclear star clusters. We also construct composite stellar populations assuming a distribution of initial rotation rates. Even in low-metallicity environments where rotation has a significant effect on the evolution of massive stars, we find that stellar population models require a significant contribution from fast-rotating (v/{v}{crit}> 0.4) stars in order to sustain the production of ionizing photons beyond a few Myr following a starburst. These results have potentially important implications for cosmic reionization by massive stars and the interpretation of nebular emission lines in high-redshift star-forming galaxies.

  13. Massive Haemorrhagic Ascites and Pleural effusion: An Unusual ...

    African Journals Online (AJOL)

    The association between endometriosis and haemorrhagic (bloody) ascites is rare.Since its first description by Brews in 1954,only a few sporadic cases have been reported in the literature. We report a case of massive haemorrhagic ascites associated with right-sided pleural effussion.Therapeutic paracentesis of eight litres ...

  14. Sinus Histiocytosis with Massive Lymphadenopathy | Sinclair-Smith ...

    African Journals Online (AJOL)

    Two cases of a recently described entity, 'sinus histiocytosis with massive lymphadenopathy,' occurring in Black males, are reported. Prominent cervical adenopathy was the main presenting feature in both. Histologically, these nodes were characterised by pronounced proliferation of sinus histiocytes which showed ...

  15. Near-Infrared Mass Loss Diagnostics for Massive Stars

    Science.gov (United States)

    Sonneborn, George; Bouret, J. C.

    2010-01-01

    Stellar wind mass loss is a key process which modifies surface abundances, luminosities, and other physical properties of hot, massive stars. Furthermore, mass loss has to be understood quantitatively in order to accurately describe and predict massive star evolution. Two urgent problems have been identified that challenge our understanding of line-driven winds, the so-called weak-wind problem and wind clumping. In both cases, mass-loss rates are drastically lower than theoretically expected (up to a factor 1001). Here we study how the expected spectroscopic capabilities of the James Webb Space Telescope (JWST), especially NIRSpec, could be used to significantly improve constraints on wind density structures (clumps) and deep-seated phenomena in stellar winds of massive stars, including OB, Wolf-Rayet and LBV stars. Since the IR continuum of objects with strong winds is formed in the wind, IR lines may sample different depths inside the wind than UV-optical lines and provide new information about the shape of the velocity field and clumping properties. One of the most important applications of IR line diagnostics will be the measurement of mass-loss rates in massive stars with very weak winds by means of the H I Bracket alpha line, which has been identified as one of the most promising diagnostics for this problem.

  16. Small scale kinematics of massive star-forming cores

    NARCIS (Netherlands)

    Wang, Kuo-Song

    2013-01-01

    Unlike the formation of Solar-type stars, the formation of massive stars (M>8 Msun) is not yet well understood. For Solar-type protostars, the presence of circumstellar or protoplanetary disks which provide a path for mass accretion onto protostars is well established. However, to date only few

  17. Discovery of X-ray pulsations from a massive star.

    Science.gov (United States)

    Oskinova, Lidia M; Nazé, Yael; Todt, Helge; Huenemoerder, David P; Ignace, Richard; Hubrig, Swetlana; Hamann, Wolf-Rainer

    2014-06-03

    X-ray emission from stars much more massive than the Sun was discovered only 35 years ago. Such stars drive fast stellar winds where shocks can develop, and it is commonly assumed that the X-rays emerge from the shock-heated plasma. Many massive stars additionally pulsate. However, hitherto it was neither theoretically predicted nor observed that these pulsations would affect their X-ray emission. All X-ray pulsars known so far are associated with degenerate objects, either neutron stars or white dwarfs. Here we report the discovery of pulsating X-rays from a non-degenerate object, the massive B-type star ξ(1) CMa. This star is a variable of β Cep-type and has a strong magnetic field. Our observations with the X-ray Multi-Mirror (XMM-Newton) telescope reveal X-ray pulsations with the same period as the fundamental stellar oscillations. This discovery challenges our understanding of stellar winds from massive stars, their X-ray emission and their magnetism.

  18. Luminous blue variables and the fates of very massive stars.

    Science.gov (United States)

    Smith, Nathan

    2017-10-28

    Luminous blue variables (LBVs) had long been considered massive stars in transition to the Wolf-Rayet (WR) phase, so their identification as progenitors of some peculiar supernovae (SNe) was surprising. More recently, environment statistics of LBVs show that most of them cannot be in transition to the WR phase after all, because LBVs are more isolated than allowed in this scenario. Additionally, the high-mass H shells around luminous SNe IIn require that some very massive stars above 40  M ⊙ die without shedding their H envelopes, and the precursor outbursts are a challenge for understanding the final burning sequences leading to core collapse. Recent evidence suggests a clear continuum in pre-SN mass loss from super-luminous SNe IIn, to regular SNe IIn, to SNe II-L and II-P, whereas most stripped-envelope SNe seem to arise from a separate channel of lower-mass binary stars rather than massive WR stars.This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'. © 2017 The Author(s).

  19. Observational constraints on mass loss and evolution of massive stars

    NARCIS (Netherlands)

    de Koter, A.

    2008-01-01

    We review the empirical mass-loss properties of early-type stars in the upper part of the Hertzsprung-Russell diagram. Specifically, we focus on the relation between mass loss and chemical composition by comparing properties of massive stars in our galaxy with those in the Magellanic Clouds. The

  20. Search for Massive Neutrinos in the Decay pi --> e nu

    CERN Document Server

    Aoki, M; Bryman, D A; Chen, S; Ding, M; Doria, L; Gumplinger, P; Hurst, C; Hussein, A; Igarashi, Y; Ito, N; Kettell, S H; Kurchaninov, L; Littenberg, L; Malbrunot, C; Numao, T; Poutissou, R; Sher, A; Sullivan, T; Yamada, K; Yoshida, M; Vavilov, D

    2011-01-01

    Evidence of massive neutrinos in the pi --> e nu decay spectrum was sought with the background pi --> mu --> e decay chain highly suppressed. Upper limits (90% C.L.) on the neutrino mixing matrix element |U_ei|^2 in the neutrino mass region 60--129 MeV/c^2 were set at the level of 10^-8.

  1. The Geopolitics and Meanings of India's Massive Skills Development Ambitions

    Science.gov (United States)

    King, Kenneth

    2012-01-01

    This paper interrogates the drivers and meanings behind the dramatic rise of technical and vocational education and training in the policy and political agenda of India. What are the assumptions about the existing traditions and character of India's culture or cultures of skills development? Is the massive planned expansion of skilled people in…

  2. Massively Multiplayer Online Games (MMOs) in the New Media Classroom

    Science.gov (United States)

    Delwiche, Aaron

    2006-01-01

    Recent research demonstrates that videogames enhance literacy, attention, reaction time, and higher-level thinking. Several scholars have suggested that massively multiplayer online games (MMOs) such as "Everquest" and "Second Life" have educational potential, but we have little data about what happens when such tools are introduced in the…

  3. A Predictive Model for Massive Transfusion in Combat Casualty Patients

    Science.gov (United States)

    2008-02-01

    addition to acute hemorrhage, hypothermia, acido - sis, and coagulopathy have been demonstrated to perpetu- ate the ongoing cycle of bleeding.17 Recent...massively transfused trauma patient: hypothermia and acidoses revisited. J Trauma. 1997;42:857–862. 18. Brohi K, Singh J, Heron M, Coats T. Acute

  4. AMIDST: Analysis of MassIve Data STreams

    DEFF Research Database (Denmark)

    Masegosa, Andres; Martinez, Ana Maria; Borchani, Hanen

    2015-01-01

    The Analysis of MassIve Data STreams (AMIDST) Java toolbox provides a collection of scalable and parallel algorithms for inference and learning of hybrid Bayesian networks from data streams. The toolbox, available at http://amidst.github.io/toolbox/ under the Apache Software License version 2...

  5. The close-binary content of massive star clusters

    Science.gov (United States)

    van den Berg, Maureen C.

    2015-08-01

    The fates of star clusters and the binaries in them are closely intertwined. Close binaries support a cluster against core collapse, while stellar encounters in the dense cores of massive star clusters shape the properties and numbers of the binaries. Observations of massive globular clusters with the Chandra X-ray Observatory have revealed hundreds of close binaries. I will present new results from deep HST observations of massive star clusters including 47Tuc, M28, and M4, that are aimed at classifying the X-ray source populations. Besides exotic systems such as low-mass X-ray binaries and millisecond pulsars, more mundane systems such as magnetically active binaries and accreting white dwarfs have been found. I will discuss how a breakdown of sources by class has revealed how the various binary populations bear the imprints of stellar encounters: some are dominated by dynamical creation, others by dynamical destruction. I will also discuss the effects on the integrated X-ray emissivity of massive star clusters, which is suppressed compared to lower-density environments.

  6. Bronchial artery embolisation for the treatment of massive ...

    African Journals Online (AJOL)

    fuse lung disease or those who are not surgical candidates.12 BAE should be considered early in the evolution of massive haemoptysis. BAE for the short-term control of haemoptysis is effective in around. 90% of cases. Incomplete embolisation is usually the reason for early rebleeding. Ten to twenty per cent of patients will ...

  7. MASSIVE PULMONARY EMBOLISM IN OLDER PATIENT: SURVIVAL DESPITE STATISTIC DATA

    Directory of Open Access Journals (Sweden)

    O. S. Makharynska

    2017-06-01

    Full Text Available Massive pulmonary thromboembolism is presented in this article on example of clinical case. Clinical investigation, prognosis evaluation tools, diagnosis and acute phase treatment along with prevention of recurrent episode of pulmonary embolism presented. Observed and described clinical case of pulmonary embolism in older patient, when patient was mistakenly diagnosed in emergency department as acute coronary syndrome patient.

  8. Massive Open Online Courses for Africa by Africa

    Science.gov (United States)

    Oyo, Benedict; Kalema, Billy Mathias

    2014-01-01

    Africa is known for inadequate access to all sorts of human needs including health, education, food, shelter, transport, security, and energy. Before the emergence of massive open online courses (MOOCs), open access to higher education (HE) was exclusive of Africa. However, as a generally affordable method of post-secondary education delivery,…

  9. MASSIVE RECTORRHAGIA IN A RURAL HOSPITAL IN KENYA.

    African Journals Online (AJOL)

    2013-05-05

    May 5, 2013 ... Despite prompt and uncomplicated surgery the patient did ... treatment. CASE REPORT. An 18 years old female patient was admitted to our hospital for massive rectorrhagia and with acute abdomen. The patient was passing fresh blood and clots from ... started a difficult and lengthy job of adhesion release.

  10. Challenges of Massive Application of Information Technologies in ...

    African Journals Online (AJOL)

    Effective diffusion of information technology and related initiatives in African Universities is hindered by various barriers. The paper investigated the challenges of massive application of information technology (IT) in Niger Delta universities in Nigeria. The research design was survey design, while the population consisted of ...

  11. Exploring Engaging Gamification Mechanics in Massive Online Open Courses

    Science.gov (United States)

    Chang, Jen-Wei; Wei, Hung-Yu

    2016-01-01

    Massive open online courses (MOOCs) have developed rapidly and become tremendously popular because of their plentiful gamification designs, such as reputation points, rewards, and goal setting. Although previous studies have mentioned a broad range of gamification designs that might influence MOOC learner engagement, most gamified MOOCs fail to…

  12. Turning points of massive particles in Schwarzschild geometry

    OpenAIRE

    Polonyi, J.; Radosz, A.; Siwek, A.; Ostasiewicz, K.

    2009-01-01

    The stable geodesics in Schwarzschild geometry can not approach the center closer than the radius of the photon sphere, 3/2 times the Schwarzschild radius. In other words, massive particles moving along geodesics that cross the photon sphere do not escape, they fall into the black hole.

  13. A rare case of massive hepatosplenomegaly due to acute ...

    African Journals Online (AJOL)

    Cancer in pregnancy is rare, occurring in about one in 1 000 preg nancies.[1] The most .... hypertension. The case highlights the importance of maintaining a high index of suspicion for uncommon causes of massive hepatosplenomegaly as well as rare ... veries in 73% of 160 pregnant patients treated with anthracycline.

  14. Urethral diverticulum with massive lithiasis presenting as a scrotal mass.

    Science.gov (United States)

    Labanaris, Apostolos P; Zugor, Vahudin; Witt, Jorn H; Nützel, Reinhold; Kühn, Reinhard

    2011-01-01

    Urethral diverticula in men are uncommon clinical entities. Their clinical manifestations include urinary tract infection, hematuria, irritative or obstructive voiding symptoms, ventral bulging and displacement of the penile shaft. Male urethral diverticulum with massive lithiasis presenting as a scrotal mass with stress urinary incontinence as the main symptom is extremely rare. Herein, we present such a case. Copyright © 2011 S. Karger AG, Basel.

  15. Massive neutrino search in the decay π+-->e+ν

    Science.gov (United States)

    Malbrunot, C.; Aoki, M.; Blecher, M.; Bryman, D. A.; Chen, S.; Ding, M.; Doria, L.; Gumplinger, P.; Hurst, C.; Hussein, A.; Igarashi, Y.; Ito, N.; Kettell, S. H.; Kurchaninov, L.; Littenberg, L.; Numao, T.; Poutissou, R.; Sher, A.; Sullivan, T.; Vavilov, D.; Yamada, K.; Yoshida, M.

    2012-09-01

    Evidence of massive neutrinos in the π+→e+ν decay spectrum was sought with the background π+→μ+→e+ decay chain highly suppressed. Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60-129 MeV/c2 were set at the level of 10-8.

  16. Classical and quantum cosmology of minimal massive bigravity

    Directory of Open Access Journals (Sweden)

    F. Darabi

    2016-10-01

    Full Text Available In a Friedmann–Robertson–Walker (FRW space–time background we study the classical cosmological models in the context of recently proposed theory of nonlinear minimal massive bigravity. We show that in the presence of perfect fluid the classical field equations acquire contribution from the massive graviton as a cosmological term which is positive or negative depending on the dynamical competition between two scale factors of bigravity metrics. We obtain the classical field equations for flat and open universes in the ordinary and Schutz representation of perfect fluid. Focusing on the Schutz representation for flat universe, we find classical solutions exhibiting singularities at early universe with vacuum equation of state. Then, in the Schutz representation, we study the quantum cosmology for flat universe and derive the Schrodinger–Wheeler–DeWitt equation. We find its exact and wave packet solutions and discuss on their properties to show that the initial singularity in the classical solutions can be avoided by quantum cosmology. Similar to the study of Hartle–Hawking no-boundary proposal in the quantum cosmology of de Rham, Gabadadze and Tolley (dRGT massive gravity, it turns out that the mass of graviton predicted by quantum cosmology of the minimal massive bigravity is large at early universe. This is in agreement with the fact that at early universe the cosmological constant should be large.

  17. Holographic renormalization of 3D minimal massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Qaemmaqami, Mohammad M.; Naseh, Ali [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Shirzad, Ahmad [Department of Physics, Isfahan University of Technology,P.O.Box 84156-83111, Isfahan (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-01-19

    We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.

  18. Bianchi type-I massive string magnetized barotropic perfect fluid ...

    Indian Academy of Sciences (India)

    Bianchi type-I massive string cosmological model for perfect fluid distribution in the presence of magnetic field is investigated in Rosen's [Gen. Relativ. Gravit. 4, 435 (1973)] bimetric theory of gravitation. To obtain the deterministic model in terms of cosmic time, we have used the condition A = ( B C ) n , where n is a constant, ...

  19. Massive Stars as Progenitors of Supernovae and GRBs

    NARCIS (Netherlands)

    Langer, N.; van Marle, A.J.; Poelarends, A.J.T.; Yoon, S.C.

    2007-01-01

    The evolutionary fate of massive stars in our Milky Way is thought to be reasonably well understood: stars above ˜ 8 M_o produce neutron stars and supernovae, while those above ˜ 20...30 M_o are presumed to form black holes. At metallicities below that of the SMC, however, our knowledge becomes

  20. Early death of massive galaxies in the distant universe

    NARCIS (Netherlands)

    Straatman, Caroline Margaretha Stefanie

    2016-01-01

    One of the major unresolved questions in astronomy is: how do galaxies form and evolve? In the local universe we can distinguish between actively star-forming and quiescent galaxies. Quiescent galaxies are typically the most massive, with elliptical morphologies and red optical colors. The

  1. Evaluation of the Efficiency of Treatment for Massive Obstetric Hemorrhage

    Directory of Open Access Journals (Sweden)

    S. V. Barinov

    2014-01-01

    Full Text Available Objective: to evaluate the efficiency of therapy for massive obstetric hemorrhage, by applying thromboelastography (TEG. Subjects and methods. Sixty six patients with massive obstetric hemorrhage who were divided into two groups: a study (A; n=37 and comparison (B; n=29 groups were examined. A control group (C; n=30 comprised women with physiological blood loss during labor. The efficiency of TEG was evaluated from the volume of blood loss and the frequency of hysterectomy.Results. Fibrin clot density, MA have the highest prognostic capacity to identify the risk of massive obstetric hemorrhage [AUC=0.83 (95% CI 0.79—0.87; р=0.001]. A therapeutic and diagnostic set for massive obstetric hemorrhage, by applying TEG, can reduce the number of hysterectomies by 3. 1 times (p=0.02, the volume of blood loss by 1.3 times (p=0.03, and the use of fresh frozen plasma by 2.0 times (p=0.01. Conclusion. Rapid evaluation of the blood coagulation system, by using a TEG® 5000 device (Haemoscope Corp., USA makes it possible to perform timely pathogenetic sound therapy, to prevent a critical condition, and to implement organ-sparing tactics.  

  2. Topologically massive gravity and the AdS/CFT correspondence

    NARCIS (Netherlands)

    Skenderis, K.; Taylor, M.; van Rees, B.C.

    2009-01-01

    We set up the AdS/CFT correspondence for topologically massive gravity (TMG) in three dimensions. The first step in this procedure is to determine the appropriate fall off conditions at infinity. These cannot be fixed a priori as they depend on the bulk theory under consideration and are derived by

  3. Bronchial Artery Embolization for Massive Hemoptysis: a Retrospective Study

    Directory of Open Access Journals (Sweden)

    Ali Fani

    2013-05-01

    Full Text Available   Introduction: To assess the efficacy and safety of bronchial artery embolization in the treatment of massive hemoptysis.   Materials and Methods: A retrospective study on 46 patients (26 males and 20 females who were referred to the Razavi Hospital from April 2009 to May 2012 with massive hemoptysis and had bronchial artery embolization procedures. General characteristics of the patients including age, gender, etiology, and thorax computed tomograms, findings of bronchial angiographic, results of the embolization, complications related to bronchial artery embolization and clinical outcome during follow-up were reviewed. Results: The etiology included previous pulmonary tuberculosis in 20 cases, previous tuberculosis with bronchiectasis in 16 cases, bronchiectasis in 6 cases, and active pulmonary tuberculosis in one case. No identifiable causes could be detected in three patients. Moreover, massive hemoptysis was successfully and immediately controlled following the embolization procedure in all patients. One patient developed recurrent hemoptysis during one month following the procedure and was treated by re-embolization. No major procedure–related complication such as bronchial infarction was identified However none of the patientsexperienced neurological complications. Conclusion: Bronchial artery embolization is a safe and effective means of controlling massive hemoptysis and should be regarded as the first-line treatment for this condition.

  4. MASSIVE VULVAR EDEMA IN A WOMAN WITH SEVERE ...

    African Journals Online (AJOL)

    2010-06-11

    Jun 11, 2010 ... We report a case of massive vulvar edema in a 20 years old primigravida woman with severe preeclampsia at 32 weeks gestation. Other causes of vulvar edema were excluded. The vulvar edema appeared as the blood pressure increased, and cesarean section was performed for increasing preeclampsia ...

  5. Massive vulvar edema in a woman with severe preeclampsia. A ...

    African Journals Online (AJOL)

    We report a case of massive vulvar edema in a 20 years old primigravida woman with severe preeclampsia at 32 weeks gestation. Other causes of vulvar edema were excluded. The vulvar edema appeared as the blood pressure increased, and cesarean section was performed for increasing preeclampsia and fetal distress.

  6. MASSIVE RECTORRHAGIA IN A RURAL HOSPITAL IN KENYA.

    African Journals Online (AJOL)

    2013-05-05

    May 5, 2013 ... A young female patient presented to our hospital for massive rectorrhagia associated with clinical signs of peritonitis. The provisional diagnosis was of sigmoid volvolus, but laparatomy demonstrated that the problem originated from. Pelvic Inflammatory Disease (PID). Despite prompt and uncomplicated ...

  7. Are Massive Open Online Courses (MOOCs) Pedagogically Innovative?

    Science.gov (United States)

    Armellini, Alejandro; Padilla Rodriguez, Brenda Cecilia

    2016-01-01

    While claims about pedagogic innovation in Massive Open Online Courses (MOOCs) are common, most reports provide no evidence to justify those claims. This paper reports on a survey aimed at exploring how different stakeholders describe MOOCs, focusing on whether they would consider them pedagogically innovative, and if so, why. Respondents (n =…

  8. Massive Open Online Courses: Disruptive Innovations or Disturbing Inventions?

    Science.gov (United States)

    de Langen, Frank; van den Bosch, Herman

    2013-01-01

    According to Christensen and Horn, Massive Open Online Courses (MOOCs) are serving non-consumers. Although they are limited in the services they provide compared with traditional colleges, they offer free and accessible education to a broader audience, who cannot afford the traditional provision. However, this is a characteristic of online…

  9. Can Massively Multiplayer Online Gaming Environments Support Team Training?

    Science.gov (United States)

    O'Connor, Debra L.; Menaker, Ellen S.

    2008-01-01

    Instructional games are created when training is deliberately added to a gaming environment or when gaming aspects are deliberately incorporated into training. One type of game that is currently attracting the attention of the education and training field is the massively multiplayer online game (MMOG). Because evidence about learning outcomes…

  10. Value and impact of massive blood transfusion protocols in the ...

    African Journals Online (AJOL)

    Bleeding trauma patients die as a consequence of the so-called lethal triad or bloody vicious cycle: acidosis, coagulopathy and hypothermia. Effective initial management of trauma patients can help to improve outcomes. Keywords: massive blood transfusion protocol, damage control surgery, damage control resuscitation, ...

  11. Domian Transfer as a Strategy Deployed to Portray Massive ...

    African Journals Online (AJOL)

    This essay is a pragmatic analysis of Olusegun Obasanjo.s open letter, dated 2nd December 2013, to the sitting president, Goodluck Ebele Jonathan. The letter titled ¡°Before It Is Too Late¡± raises pertinent national issues bothering on massive corruption and the degenerating state of the country.s social, economic, and ...

  12. Gas-phase SO2 in absorption towards massive protostars

    NARCIS (Netherlands)

    Keane, JV; Boonman, AMS; Tielens, AGGM; van Dishoeck, EF; Dishoeck, E. F.; Lahuis, F. van; Wright, C. M.; Doty, S. D.

    We present the first detection of the v(3) ro-vibrational band of gas-phase SO2 in absorption in the mid-infrared spectral region around 7.3 mum of a sample of deeply embedded massive protostars. Comparison with model spectra shows that the derived excitation temperatures correlate with previous

  13. Construction of horizontal mining facilities through schist`s massive

    OpenAIRE

    Doneva, Nikolinka; Hadzi-Nikolova, Marija; Mirakovski, Dejan; Mijalkovski, Stojance

    2013-01-01

    This paper presents cost analysis for horizontal mining facilities through schist’s massive. Two variables, headings cross section and rock-quality designation (RQD) were considered. Based on a real data analyses we were able to define two parameters functional relation between costs and cross-section. Examples and clasifications are elaborated in details.

  14. Traumatic carotid-cavernous fistula presenting as massive epistaxis.

    Science.gov (United States)

    Wyrick, Deidre; Smith, Samuel D; Dassinger, Melvin S

    2013-04-01

    Carotid-cavernous sinus fistulae (CCF) are a rare complication with the potential for great morbidity including intracranial hemorrhage, blindness, cranial nerve palsy and stroke. Traumatic CCF are the most common type of CCF. Here we discuss a patient who sustained blunt head trauma and had substantial epistaxis, requiring massive transfusion, intraoperatively due to unrecognized CCF. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Massive Open Online Courses: Looking Ahead by Looking Back

    Science.gov (United States)

    Matkin, Gary W.

    2013-01-01

    Gary W. Matkin, Dean of Continuing Education, Distance Learning, and Summer Session at the University of California, Irvine (UCI), writes about the "year of the MOOC (Massive Open Online Courses), 2012" and how over 250,000 students signed up for six courses that began in early January 2013. Within its first year Coursera had signed 62…

  16. Observational properties of massive black hole binary progenitors

    Science.gov (United States)

    Hainich, R.; Oskinova, L. M.; Shenar, T.; Marchant, P.; Eldridge, J. J.; Sander, A. A. C.; Hamann, W.-R.; Langer, N.; Todt, H.

    2018-01-01

    Context. The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ≈ 36 M⊙ and ≈ 29 M⊙. Several scenarios have been proposed to put this detection into an astrophysical context. The evolution of an isolated massive binary system is among commonly considered models. Aims: Various groups have performed detailed binary-evolution calculations that lead to BH merger events. However, the question remains open as to whether binary systems with the predicted properties really exist. The aim of this paper is to help observers to close this gap by providing spectral characteristics of massive binary BH progenitors during a phase where at least one of the companions is still non-degenerate. Methods: Stellar evolution models predict fundamental stellar parameters. Using these as input for our stellar atmosphere code (Potsdam Wolf-Rayet), we compute a set of models for selected evolutionary stages of massive merging BH progenitors at different metallicities. Results: The synthetic spectra obtained from our atmosphere calculations reveal that progenitors of massive BH merger events start their lives as O2-3V stars that evolve to early-type blue supergiants before they undergo core-collapse during the Wolf-Rayet phase. When the primary has collapsed, the remaining system will appear as a wind-fed high-mass X-ray binary. Based on our atmosphere models, we provide feedback parameters, broad band magnitudes, and spectral templates that should help to identify such binaries in the future. Conclusions: While the predicted parameter space for massive BH binary progenitors is partly realized in nature, none of the known massive binaries match our synthetic spectra of massive BH binary progenitors exactly. Comparisons of empirically determined mass-loss rates with those assumed by evolution calculations reveal significant differences. The consideration of the empirical mass-loss rates in evolution calculations will

  17. Highly accurate quantitative spectroscopy of massive stars in the Galaxy

    Science.gov (United States)

    Nieva, María-Fernanda; Przybilla, Norbert

    2017-11-01

    Achieving high accuracy and precision in stellar parameter and chemical composition determinations is challenging in massive star spectroscopy. On one hand, the target selection for an unbiased sample build-up is complicated by several types of peculiarities that can occur in individual objects. On the other hand, composite spectra are often not recognized as such even at medium-high spectral resolution and typical signal-to-noise ratios, despite multiplicity among massive stars is widespread. In particular, surveys that produce large amounts of automatically reduced data are prone to oversight of details that turn hazardous for the analysis with techniques that have been developed for a set of standard assumptions applicable to a spectrum of a single star. Much larger systematic errors than anticipated may therefore result because of the unrecognized true nature of the investigated objects, or much smaller sample sizes of objects for the analysis than initially planned, if recognized. More factors to be taken care of are the multiple steps from the choice of instrument over the details of the data reduction chain to the choice of modelling code, input data, analysis technique and the selection of the spectral lines to be analyzed. Only when avoiding all the possible pitfalls, a precise and accurate characterization of the stars in terms of fundamental parameters and chemical fingerprints can be achieved that form the basis for further investigations regarding e.g. stellar structure and evolution or the chemical evolution of the Galaxy. The scope of the present work is to provide the massive star and also other astrophysical communities with criteria to evaluate the quality of spectroscopic investigations of massive stars before interpreting them in a broader context. The discussion is guided by our experiences made in the course of over a decade of studies of massive star spectroscopy ranging from the simplest single objects to multiple systems.

  18. The VLT-FLAMES Tarantula Survey. III. A very massive star in apparent isolation from the massive cluster R136

    NARCIS (Netherlands)

    Bestenlehner, J.M.; Vink, J.S.|info:eu-repo/dai/nl/212372971; Gräfener, G.; Najarro, F.; Evans, C.J.; Bastian, N.; Bonanos, A.Z.; Bressert, E.; Crowther, P.A.; Doran, E.; Friedrich, K.; Hénault-Brunet, V.; Herrero, A.; de Koter, A.; Langer, N.|info:eu-repo/dai/nl/304829498; Lennon, D.J.; Maíz Apellániz, J.; Sana, H.; Soszynski, I.; Taylor, W.D.

    2011-01-01

    VFTS 682 is located in an active star-forming region, at a projected distance of 29 pc from the young massive cluster R136 in the Tarantula Nebula of the Large Magellanic Cloud. It was previously reported as a candidate young stellar object, and more recently spectroscopically revealed as a

  19. Kinematics of the inner thousand AU region around the young massive star AFGL 2591-VLA3: a massive disk candidate?

    NARCIS (Netherlands)

    Wang, K. -S.; van der Tak, F. F. S.; Hogerheijde, M. R.

    Context. Recent detections of disks around young high-mass stars support the idea of massive star formation through accretion rather than coalescence, but the detailed kinematics in the equatorial region of the disk candidates is not well known, which limits our understanding of the accretion

  20. Requirements for supercomputing in energy research: The transition to massively parallel computing

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    This report discusses: The emergence of a practical path to TeraFlop computing and beyond; requirements of energy research programs at DOE; implementation: supercomputer production computing environment on massively parallel computers; and implementation: user transition to massively parallel computing.

  1. Results from massive underground detectors on solar and atmospheric neutrino studies and proton decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki, E-mail: kajita@icrr.u-tokyo.ac.jp [ICRR and IPMU, University of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa, Chiba 277-8582 (Japan)

    2011-07-25

    Massive underground detectors have been playing important roles in particle and astro-particle physics. Results from massive underground detectors on solar and atmospheric neutrino studies and proton decay searches are reviewed.

  2. Homogeneous solutions of minimal massive 3D gravity

    Science.gov (United States)

    Charyyev, Jumageldi; Deger, Nihat Sadik

    2017-07-01

    In this paper, we systematically construct simply transitive homogeneous spacetime solutions of the three-dimensional minimal massive gravity (MMG) model. In addition to those that have analogs in topologically massive gravity, such as warped AdS and p p waves, there are several solutions genuine to MMG. Among them, there is a stationary Lifshitz metric with the dynamical exponent z =-1 and an anisotropic Lifshitz solution where all coordinates scale differently. Moreover, we identify a homogeneous Kundt-type solution at the chiral point of the theory. We also show that in a particular limit of the physical parameters in which the Cotton tensor drops out from the MMG field equation, homogeneous solutions exist only at the merger point in the parameter space if they are not conformally flat.

  3. Coronagraphic imaging of circumstellar material around evolved massive stars

    Science.gov (United States)

    Lomax, Jamie R.; Levesque, Emily; Wisniewski, John

    2018-01-01

    While many astronomical subfields (e.g. the solar, exoplanet, and disk communities) have been using coronagraphy to combat contrast ratio problems for years, the use of coronagraphic imaging techniques to probe the circumstellar environments of massive stars has been surprisingly underutilized. While current extreme adaptive optics coronagraphic imaging systems (e.g. GPI on Gemini South, SPHERE at the VLT, and SCExAO at Subaru) were built for the sole purpose of detecting exoplanets, their ability to provide large contrast ratios and small inner working angles means they can detect gas, dust, and companions that are closer to the central star than ever before. In this poster we present pilot studies of evolved massive stars using several coronagraphic imaging systems and summarize potential science gains this technique might provide.

  4. Programming massively parallel processors a hands-on approach

    CERN Document Server

    Kirk, David B

    2010-01-01

    Programming Massively Parallel Processors discusses basic concepts about parallel programming and GPU architecture. ""Massively parallel"" refers to the use of a large number of processors to perform a set of computations in a coordinated parallel way. The book details various techniques for constructing parallel programs. It also discusses the development process, performance level, floating-point format, parallel patterns, and dynamic parallelism. The book serves as a teaching guide where parallel programming is the main topic of the course. It builds on the basics of C programming for CUDA, a parallel programming environment that is supported on NVI- DIA GPUs. Composed of 12 chapters, the book begins with basic information about the GPU as a parallel computer source. It also explains the main concepts of CUDA, data parallelism, and the importance of memory access efficiency using CUDA. The target audience of the book is graduate and undergraduate students from all science and engineering disciplines who ...

  5. The impact of temperature loading on massive concrete block resistance

    Science.gov (United States)

    Beran, Pavel; Kočí, Jan

    2017-07-01

    Very large and massive concrete blocks with thickness in interval 3.5 - 6 meters are often designed in cement industry. These massive blocks have high heat inertial and thus the thermal stress due to nonlinear temperature gradient in concrete block may occur. The coupled thermo-mechanical analysis of concrete block in Prague Czech Republic and Sterlitamak Russia was made. By the numerical model of concrete block was analyzed the typical year (called reference year) in particular localities. The results show that in concrete block the thermal stresses which are higher than the tensile strength of concrete originate. Therefore, the concrete block should be reinforced by steel rods. The values of stresses are markedly affected by climate. The significantly higher values of thermal stresses were detected in Sterlitamak than in Prague.

  6. OBSERVATIONAL SIGNATURES OF CONVECTIVELY DRIVEN WAVES IN MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, C. [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Rogers, T. M. [Department of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne (United Kingdom)

    2015-06-20

    We demonstrate observational evidence for the occurrence of convectively driven internal gravity waves (IGWs) in young massive O-type stars observed with high-precision CoRoT space photometry. This evidence results from a comparison between velocity spectra based on two-dimensional hydrodynamical simulations of IGWs in a differentially rotating massive star and the observed spectra. We also show that the velocity spectra caused by IGWs may lead to detectable line-profile variability and explain the occurrence of macroturbulence in the observed line profiles of OB stars. Our findings provide predictions that can readily be tested by including a sample of bright, slowly and rapidly rotating OB-type stars in the scientific program of the K2 mission accompanied by high-precision spectroscopy and their confrontation with multi-dimensional hydrodynamic simulations of IGWs for various masses and ages.

  7. Massive hemoptysis caused by tracheal hemangioma treated with interventional radiology.

    Science.gov (United States)

    Zambudio, Antonio Ríos; Calvo, Maria Jose Roca; Lanzas, Juan Torres; Medina, J García; Paricio, Pascual Parrilla

    2003-04-01

    Capillary hemangiomas of the tracheobronchial tree are extremely rare in adults, with hemoptysis being one of the most serious forms of presentation. An operation has been the treatment of choice, although it does involve high rates of morbidity and mortality, especially in emergency situations such as massive hemoptysis, which has led to the search for other therapeutic alternatives. There is no experience with embolization by interventional radiology when the hemoptysis is tracheal in origin, caused partly because the infrequency of this pathology; however, the foundations for it have been laid with the development of embolization for bronchopulmonary pathology. We report a case of a tracheal capillary hemangioma in a 66-year-old woman diagnosed with idiopathic thrombopenic purpura, which began as a massive hemoptysis and was treated successfully with embolization by interventional radiology. There has been no recurrence of the bleeding after 1 year's follow-up, and the patient's control fibrobronchoscopy is normal.

  8. Bilateral massive ovarian luteinized follicular cysts of a twin pregnancy.

    Science.gov (United States)

    Teng, Li-Song; Jin, Ke-Tao; He, Kui-Feng; Zhu, Tie-Ming; Zhao, Fan; Jin, Zhi-Gang

    2010-12-01

    We report a case of rare bilateral massive ovarian luteinized follicular cysts in a twin pregnancy. A 28-year-old, gravida 1, para 0, abortus 0 woman was incidentally found to have bilateral massive ovarian cysts (left side, 12 × 10 × 8 cm; right side, 15 × 10 × 6 cm) during the cesarean delivery of a twin pregnancy at 36 weeks of gestation. After 1,950-g and 2,350-g female babies were delivered in good condition, the patient received bilateral oophorectomy. Subsequent histopathology led to the diagnosis of giant bilateral ovarian luteinized follicular cysts. Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

  9. Magnetic fields in the formation of massive stars.

    Science.gov (United States)

    Girart, Josep M; Beltrán, Maria T; Zhang, Qizhou; Rao, Ramprasad; Estalella, Robert

    2009-06-12

    Massive stars play a crucial role in the production of heavy elements and in the evolution of the interstellar medium, yet how they form is still a matter of debate. We report high-angular-resolution submillimeter observations toward the massive hot molecular core (HMC) in the high-mass star-forming region G31.41+0.31. We find that the evolution of the gravitational collapse of the HMC is controlled by the magnetic field. The HMC is simultaneously contracting and rotating, and the magnetic field lines threading the HMC are deformed along its major axis, acquiring an hourglass shape. The magnetic energy dominates over the centrifugal and turbulence energies, and there is evidence of magnetic braking in the contracting core.

  10. RESULTS OF TENEKTEPLASE USE IN MASSIVE PULMONARY THROMBOEMBOLISM. CLINICAL CASE

    Directory of Open Access Journals (Sweden)

    R. Rajan

    2011-01-01

    Full Text Available Pulmonary thromboembolism (PTE — a life-threatening condition that can lead to death at any age. PTE — is not an independent disease, but it is a complication of venous thromboembolism. Conflicting opinions about the possibility of using tissue plasminogen activator (tenekteplase expressed in the literature. Clinical case of the tenekteplase use in 42 years old woman with acute massive PTE and its results are described. PTE in the case was observed simultaneously with diabetic ketoacidosis. Full resolution of this thrombus according to computer pulmonary angiography was observed in patient hospitalized within 24 hours after symptom onset. This is one of the first cases of effective application of the tenekteplase in patients with massive PTE and diabetic ketoacidosis.

  11. Massive Hemolysis Causing Renal Failure in Acute Hepatitis E Infection.

    Science.gov (United States)

    Karki, Pragya; Malik, Sarthak; Mallick, Bipadabhanjan; Sharma, Vishal; Rana, Surinder S

    2016-12-28

    Acute viral hepatitis is usually a self-limiting illness. However, it can lead to complications that can be life-threatening, such as acute liver failure. Glucose 6 phosphate dehydrogenase (G6PD) deficiency in the setting of acute viral hepatitis can lead to a massive hemolysis, manifesting as acute kidney injury and markedly raised bilirubin levels; although cases are rare. Here, we report such a case. The patient had a viral hepatitis E infection and presented with kidney injury requiring dialysis. Examination showed very high mixed hyperbilirubinemia due to massive intravascular hemolysis. The patient experienced a long, protracted course of illness, requiring renal replacement therapy with other supportive management, which led to improvement over a period of four weeks. This case highlights the importance of recognizing associated hemolysis in a patient with viral hepatitis who presents with very high bilirubin levels or associated kidney injury. Such patients will require aggressive supportive care with prompt fluid and electrolyte management.

  12. Magnetic brane solutions in Gauss–Bonnet–Maxwell massive gravity

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Hendi

    2017-09-01

    Full Text Available Magnetic branes of Gauss–Bonnet–Maxwell theory in the context of massive gravity is studied in detail. Exact solutions are obtained and their interesting geometrical properties are investigated. It is argued that although these horizonless solutions are free of curvature singularity, they enjoy a cone-like geometry with a conic singularity. In order to investigate the effects of various parameters on the geometry of conic singularity, its corresponding deficit angle is studied. It will be shown that despite the effects of Gauss–Bonnet gravity on the solutions, deficit angle is free of Gauss–Bonnet parameter. On the other hand, the effects of massive gravity, cosmological constant and electrical charge on the deficit angle will be explored. Also, a brief discussion related to possible geometrical phase transition of these topological objects is given.

  13. Massively Parallel Functional Analysis of BRCA1 RING Domain Variants.

    Science.gov (United States)

    Starita, Lea M; Young, David L; Islam, Muhtadi; Kitzman, Jacob O; Gullingsrud, Justin; Hause, Ronald J; Fowler, Douglas M; Parvin, Jeffrey D; Shendure, Jay; Fields, Stanley

    2015-06-01

    Interpreting variants of uncertain significance (VUS) is a central challenge in medical genetics. One approach is to experimentally measure the functional consequences of VUS, but to date this approach has been post hoc and low throughput. Here we use massively parallel assays to measure the effects of nearly 2000 missense substitutions in the RING domain of BRCA1 on its E3 ubiquitin ligase activity and its binding to the BARD1 RING domain. From the resulting scores, we generate a model to predict the capacities of full-length BRCA1 variants to support homology-directed DNA repair, the essential role of BRCA1 in tumor suppression, and show that it outperforms widely used biological-effect prediction algorithms. We envision that massively parallel functional assays may facilitate the prospective interpretation of variants observed in clinical sequencing. Copyright © 2015 by the Genetics Society of America.

  14. Reappraising the concept of massive transfusion in trauma

    DEFF Research Database (Denmark)

    Stanworth, Simon J; Morris, Timothy P; Gaarder, Christine

    2010-01-01

    transfusion requirements could allow early activation of blood bank protocols. METHODS : Datasets on trauma admissions over a 1 or 2-year period were obtained from the trauma registries of five large trauma research networks. A fractional polynomial was used to model the transfusion-associated probability...... of death. A logistic regression model for the prediction of massive transfusion, defined as 10 or more units of red cell transfusions, was developed. RESULTS : In total, 5,693 patient records were available for analysis. Mortality increased as transfusion requirements increased, but the model indicated...... no threshold effect. Mortality was 9% in patients who received none to five PRBC units, 22% in patients receiving six to nine PRBC units, and 42% in patients receiving 10 or more units. A logistic model for prediction of massive transfusion was developed and validated at multiple sites but achieved only...

  15. Attempted Suicide by Massive Warfarin Ingestion Conservatively Managed Using Phytonadione

    Directory of Open Access Journals (Sweden)

    Katherine L. March

    2016-01-01

    Full Text Available Treatment strategies for acute toxicity following massive ingestion of warfarin are not well described in the literature. Warfarin is the primary oral anticoagulation agent used in the treatment of thromboembolic disease, and patients with acute toxicity are at risk for life-threatening hemorrhages. Treatment options include phytonadione (vitamin K1, fresh frozen plasma (FFP, and prothrombin complex concentrates (PCCs used alone or in combination. FFP and PCC can be associated with volume complications, undesirable thromboembolic events, and increased costs. We describe the case of a 63-year-old female with acute warfarin toxicity following a massive ingestion of warfarin (420 mg–450 mg in an attempt to commit suicide. Upon arrival to the emergency department, serial INR checks were initiated to help guide dosing strategy and later adjusted based on INR response to treatment using only phytonadione.

  16. Massively Parallel Computers: The Connection Machine and NON-VON.

    Science.gov (United States)

    Gabriel, R P

    1986-02-28

    The demand for high-speed computers is increasing, and as the limits on single-processor computers are approached, researchers are turning their attention to parallel computers. Parallel computers have more than one processing element; massively parallel computers contain many processing elements. Constructing computers on this scale and learning how to program them effectively will be major challenges in the next decade. Several such computers, for example the Connection Machine and the NON-VON, are under development.

  17. MIMD massively parallel methods for engineering and science problems

    Energy Technology Data Exchange (ETDEWEB)

    Camp, W.J.; Plimpton, S.J.

    1993-08-01

    MIMD massively parallel computers promise unique power and flexibility for engineering and scientific simulations. In this paper we review the development of a number of software methods and algorithms for scientific and engineering problems which are helping to realize that promise. We discuss new domain decomposition, load balancing, data layout and communications methods applicable to simulations in a broad range of technical field including signal processing, multi-dimensional structural and fluid mechanics, materials science, and chemical and biological systems.

  18. Strong interactions and exact solutions in nonlinear massive gravity

    OpenAIRE

    Koyama, Kazuya; Niz, Gustavo; Tasinato, Gianmassimo

    2011-01-01

    We investigate strong coupling effects in a covariant massive gravity model, which is a candidate for a ghost-free nonlinear completion of Fierz-Pauli. We analyze the conditions to recover general relativity via the Vainshtein mechanism in the weak field limit, and find three main cases depending on the choice of parameters. In the first case, the potential is such that all nonlinearities disappear and the vDVZ discontinuity cannot be avoided. In the second case, the Vainshtein mechanism allo...

  19. Fluid Resuscitation and Massive Transfusion Protocol in Pediatric Trauma

    OpenAIRE

    Marjanović Vesna; Budić Ivana

    2016-01-01

    Trauma is the leading cause of morbidity and mortality in children due to the occurrence of hemorrhagic shock. Hemorrhagic shock and its consequences, anemia and hypovolemia, decrease oxygen delivery, due to which appropriate transfusion and volume resuscitation are critical. Guidelines for massive transfusion, in the pediatric trauma, have not been defined yet. Current data indicate that early identification of coagulopathy and its treatment with RBSs, plasma and platelets in a 1:1:1 unit ra...

  20. Advances in Domain Mapping of Massively Parallel Scientific Computations

    Energy Technology Data Exchange (ETDEWEB)

    Leland, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hendrickson, Bruce A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    One of the most important concerns in parallel computing is the proper distribution of workload across processors. For most scientific applications on massively parallel machines, the best approach to this distribution is to employ data parallelism; that is, to break the datastructures supporting a computation into pieces and then to assign those pieces to different processors. Collectively, these partitioning and assignment tasks comprise the domain mapping problem.

  1. The Hydrangea simulations: galaxy formation in and around massive clusters

    Science.gov (United States)

    Bahé, Yannick M.; Barnes, David J.; Dalla Vecchia, Claudio; Kay, Scott T.; White, Simon D. M.; McCarthy, Ian G.; Schaye, Joop; Bower, Richard G.; Crain, Robert A.; Theuns, Tom; Jenkins, Adrian; McGee, Sean L.; Schaller, Matthieu; Thomas, Peter A.; Trayford, James W.

    2017-10-01

    We introduce the Hydrangea simulations, a suite of 24 cosmological hydrodynamic zoom-in simulations of massive galaxy clusters (M200c = 1014-1015.4 M⊙) with baryon particle masses of ˜106 M⊙. Designed to study the impact of the cluster environment on galaxy formation, they are a key part of the `Cluster-EAGLE' project. They use a galaxy formation model developed for the EAGLE project, which has been shown to yield both realistic field galaxies and hot gas fractions of galaxy groups consistent with observations. The total stellar mass content of the simulated clusters agrees with observations, but central cluster galaxies are too massive, by up to 0.6 dex. Passive satellite fractions are higher than in the field, and at stellar masses Mstar > 1010 M⊙, this environmental effect is quantitatively consistent with observations. The predicted satellite stellar mass function matches data from local cluster surveys. Normalized to total mass, there are fewer low-mass (Mstar ≲ 1010 M⊙) galaxies within the virial radius of clusters than in the field, primarily due to star formation quenching. Conversely, the simulations predict an overabundance of massive galaxies in clusters compared to the field that persists to their far outskirts (>5 r200c). This is caused by a significantly increased stellar mass fraction of (sub-)haloes in the cluster environment, by up to ˜0.3 dex even well beyond r200c. Haloes near clusters are also more concentrated than equally massive field haloes, but these two effects are largely uncorrelated.

  2. Reappraising the concept of massive transfusion in trauma

    DEFF Research Database (Denmark)

    Stanworth, Simon J; Morris, Timothy P; Gaarder, Christine

    2010-01-01

    transfusion requirements could allow early activation of blood bank protocols. METHODS : Datasets on trauma admissions over a 1 or 2-year period were obtained from the trauma registries of five large trauma research networks. A fractional polynomial was used to model the transfusion-associated probability...... transfusion as a concept in trauma has limited utility, and emphasis should be placed on identifying patients with massive hemorrhage and acute traumatic coagulopathy....

  3. Ilizarov bone transport after massive tibial trauma: Case report

    Directory of Open Access Journals (Sweden)

    Nader S. Alkenani

    2016-01-01

    Conclusion: The use of bone transport technique using Ilizarov external rings has proved to be a minimally invasive and reliable method in managing massive bone defects. Accurate application of the Ilizarov frame and proper transport of the middle segment are important factors alleviating the risk for deviation of the transported segment. However, due to the need for regular follow-ups and monitoring, it demands high compliance from the patient to achieve optimal results.

  4. Performance of Air Pollution Models on Massively Parallel Computers

    DEFF Research Database (Denmark)

    Brown, John; Hansen, Per Christian; Wasniewski, Jerzy

    1996-01-01

    To compare the performance and use of three massively parallel SIMD computers, we implemented a large air pollution model on the computers. Using a realistic large-scale model, we gain detailed insight about the performance of the three computers when used to solve large-scale scientific problems...... that involve several types of numerical computations. The computers considered in our study are the Connection Machines CM-200 and CM-5, and the MasPar MP-2216...

  5. Toward Emotionally Accessible Massive Open Online Courses (MOOCs).

    Science.gov (United States)

    Hillaire, Garron; Iniesto, Francisco; Rienties, Bart

    2017-01-01

    This paper outlines an approach to evaluating the emotional content of three Massive Open Online Courses (MOOCs) using the affective computing approach of prosody detection on two different text-to-speech voices in conjunction with human raters judging the emotional content of course text. The intent of this work is to establish the potential variation on the emotional delivery of MOOC material through synthetic voice.

  6. MOOCs 101: an introduction to massive open online courses.

    Science.gov (United States)

    Hoy, Matthew B

    2014-01-01

    Massive Open Online Courses (MOOCs) are a new type of online class that allow anyone, anywhere, to participate via video lectures, computer graded tests, and discussion forums. This article will give a basic overview of what MOOCs are, how they work, and some of their inherent advantages and disadvantages. It will also explore what MOOCs mean for medical education and libraries. A list of MOOC-related resources is also included.

  7. Performance Analysis of (TDD) Massive MIMO with Kalman Channel Prediction

    OpenAIRE

    Kashyap, Salil; Mollén, Christopher; Emil, Björnson; Larsson, Erik G.

    2017-01-01

    In massive MIMO systems, which rely on uplink pilots to estimate the channel, the time interval between pilot transmissions constrains the length of the downlink.  Since switching between up- and downlink takes time, longer downlink blocks increase the effective spectral efficiency.  We investigate the use of low-complexity channel models and Kalman filters for channel prediction, to allow for longer intervals between the pilots.  Specifically, we quantify how often uplink pilots have to be s...

  8. Shift: A Massively Parallel Monte Carlo Radiation Transport Package

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Tara M [ORNL; Johnson, Seth R [ORNL; Davidson, Gregory G [ORNL; Evans, Thomas M [ORNL; Hamilton, Steven P [ORNL

    2015-01-01

    This paper discusses the massively-parallel Monte Carlo radiation transport package, Shift, developed at Oak Ridge National Laboratory. It reviews the capabilities, implementation, and parallel performance of this code package. Scaling results demonstrate very good strong and weak scaling behavior of the implemented algorithms. Benchmark results from various reactor problems show that Shift results compare well to other contemporary Monte Carlo codes and experimental results.

  9. Very Massive Stars in the Primitive Galaxy, IZw 18

    Science.gov (United States)

    Heap, Sara

    2012-01-01

    IZw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass greater than 10(exp 9) Msun, strong photoionizing radiation, no galactic outflow, and very low metallicity,log(O/H)+12=7.2. We will describe the properties and evolutionary status of very massive stars in IZw 18, based on UV photometry of individual stars in I Zw 18 and analysis of unresolved ultraviolet spectra of IZw 18-NW obtained with HST.

  10. Massive pre-main-sequence stars in M17

    Science.gov (United States)

    Ramírez-Tannus, M. C.; Kaper, L.; de Koter, A.; Tramper, F.; Sana, H.; Ramírez-Agudelo, O. H.; Bik, A.; Ellerbroek, L. E.; Ochsendorf, B. B.

    2017-11-01

    We obtained VLT/X-shooter spectra of twelve candidate young massive stars previously selected by Hanson et al. (1997) in the giant Hii region M17. An analysis of their spectra using FASTWIND models (Puls et al. 2005) shows that they span a mass range of 6 - 20 M⊙. We identify the presence of gaseous and dusty disks around six sources based on emission lines in the spectrum and infrared continuum excess.

  11. Cheating and Virtual Crime in Massively Multiplayer Online Games

    OpenAIRE

    Joshi, Rahul

    2009-01-01

    Massively Multiplayer Online Games (MMOG) have become extremely popular since the birth of the Internet, with many millions of players playing games such as Poker and World of Warcraft. However, they do not seem to be well understood, and academic research into them has been limited. This project explains the nature of MMOG, and the relationship between MMOG and information security. This project discusses the problem of cheating in MMOG and it explains what cheating i...

  12. A massively parallel corpus: the Bible in 100 languages.

    Science.gov (United States)

    Christodouloupoulos, Christos; Steedman, Mark

    We describe the creation of a massively parallel corpus based on 100 translations of the Bible. We discuss some of the difficulties in acquiring and processing the raw material as well as the potential of the Bible as a corpus for natural language processing. Finally we present a statistical analysis of the corpora collected and a detailed comparison between the English translation and other English corpora.

  13. Massive renormalization scheme and perturbation theory at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Blaizot, Jean-Paul, E-mail: jean-paul.blaizot@cea.fr [Institut de Physique Théorique, CNRS/URA2306, CEA-Saclay, 91191 Gif-sur-Yvette (France); Wschebor, Nicolás [Instituto de Fìsica, Faculdad de Ingeniería, Universidade de la República, 11000 Montevideo (Uruguay)

    2015-02-04

    We argue that the choice of an appropriate, massive, renormalization scheme can greatly improve the apparent convergence of perturbation theory at finite temperature. This is illustrated by the calculation of the pressure of a scalar field theory with quartic interactions, at 2-loop order. The result, almost identical to that obtained with more sophisticated resummation techniques, shows a remarkable stability as the coupling constant grows, in sharp contrast with standard perturbation theory.

  14. Search for massive neutrinos in π+-->μ+ν decay

    Science.gov (United States)

    Bryman, D. A.; Numao, T.

    1996-01-01

    Evidence of massive neutrinos was sought in the π+-->μ+x decay spectrum in the mass region Mx=30-33.91 MeV/c2. Upper limits on the branching ratio Rμx<=(4-6)×10-5 (90% C.L.) were set for this region, which correspond to the neutrino mixing parameter ||Uμx||2<10-3-10-4.

  15. Search for massive neutrinos in the decay. pi -->. e. nu

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.A.; Dubois, R.; Numao, T.; Olaniyi, B.; Olin, A.; Dixit, M.S.; Poutissou, J.; Macdonald, J.A.

    1983-05-16

    The positron spectrum from the decay ..pi../sup +/..-->..e/sup +/..nu../sub e/ has been examined for evidence of peaks arising from an admixture in the ..nu../sub e/ weak eigenstate of massive neutrinos. Limits on the intensity of such peaks, together with the measured ..pi -->..e..nu.. branching ratio, have been used to derive constraints on the neutrino mixing parameters over the range 4 MeV

  16. Analysis of massive data streams using R and AMIDST

    DEFF Research Database (Denmark)

    Madsen, Anders Læsø; Salmerón, Antonio

    methods able to handle massive data streams based on Bayesian networks technology. All of the developed methods are available through the AMIDST toolbox, implemented in Java 8. We show how the functionality of the AMIDST toolbox can be accessed from R. Available AMIDST objects include variables......, distributions and Bayesian networks, as well as those devoted to inference and learning. The interaction between both platforms relies on the rJava package....

  17. The nature of ultra-massive lens galaxies

    Science.gov (United States)

    Canameras, Raoul

    2017-08-01

    During the past decade, strong gravitational lensing analyses have contributed tremendously to the characterization of the inner properties of massive early-type galaxies, beyond the local Universe. Here we intend to extend studies of this kind to the most massive lens galaxies known to date, well outside the mass limits investigated by previous lensing surveys. This will allow us to probe the physics of the likely descendants of the most violent episodes of star formation and of the compact massive galaxies at high redshift. We propose WFC3 imaging (F438W and F160W) of four extremely massive early-type lens galaxies at z 0.5, in order to put them into context with the evolutionary trends of ellipticals as a function of mass and redshift. These systems were discovered in the SDSS and show one single main lens galaxy with a stellar mass above 1.5x10^12 Msun and large Einstein radii. Our high-resolution spectroscopic follow-up with VLT/X-shooter provides secure lens and source redshifts, between 0.3 and 0.7 and between 1.5 and 2.5, respectively, and confirm extreme stellar velocity dispersions > 400 km/s for the lenses. The excellent angular resolution of the proposed WFC3 imaging - not achievable from the ground - is the remaining indispensable piece of information to :(1) Resolve the lens structural parameters and obtain robust measurements of their stellar mass distributions,(2) Model the amount and distribution of the lens total masses and measure their M/L ratios and stellar IMF with joint strong lensing and stellar dynamics analyses,(3) Enhance our on-going lens models through the most accurate positions and morphologies of the blue multiply-imaged sources.

  18. [Massive GIST of the stomach--case report].

    Science.gov (United States)

    Jovović, M; Bajić, P; Golubović, M; Dobricanin, V; Marić, I

    2007-01-01

    Gastrointestinal stromal tumors (GIST) are rare mesenchimal neoplasmas of the gastrointestinal tract. The diagnosis of this tumors are oftenly very difficult. Patients with this tumor are ussualy addmited to the hospital cause of the gastrointestinal bleeding, abdominal pain, abdominal distension, disphagia, obstructive jaundice and bowel obsstruction. In this case report, we present a 86 year old patient with massive GIST of the stomach which was not preoperatively diagnosed.

  19. A massive infestation of sea snakes by cymothoid isopods.

    Science.gov (United States)

    Saravanakumar, A; Balasubramanian, T; Raja, K; Trilles, Jean-Paul

    2012-06-01

    In this study, a massive infestation of the sea snake Enhydrina schistosa by the cymothoid isopod Nerocila serra, commonly parasitizing fishes, is reported for the first time from India. This isopod was found attached on the different parts of the body of the snake. According to the month, the parasitic prevalence ranged from 30.8 to 55.3%, increasing during the monsson period. It was higher in female than in male snakes.

  20. An unstable truth: how massive stars get their mass

    Science.gov (United States)

    Rosen, Anna L.; Krumholz, Mark R.; McKee, Christopher F.; Klein, Richard I.

    2016-12-01

    The pressure exerted by massive stars' radiation fields is an important mechanism regulating their formation. Detailed simulation of massive star formation therefore requires an accurate treatment of radiation. However, all published simulations have either used a diffusion approximation of limited validity; have only been able to simulate a single star fixed in space, thereby suppressing potentially important instabilities; or did not provide adequate resolution at locations where instabilities may develop. To remedy this, we have developed a new, highly accurate radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform 3D radiation-hydrodynamic simulations of the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channelled to the stellar system via gravitational and Rayleigh-Taylor (RT) instabilities, in agreement with previous results using stars capable of moving, but in disagreement with methods where the star is held fixed or with simulations that do not adequately resolve the development of RT instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of instability, but does not suppress it entirely provided the edges of radiation-dominated bubbles are adequately resolved. Instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. Our results suggest that RT features should be present around accreting massive stars throughout their formation.

  1. Efficient channel estimation in massive MIMO systems - a distributed approach

    KAUST Repository

    Al-Naffouri, Tareq Y.

    2016-01-21

    We present two efficient algorithms for distributed estimation of channels in massive MIMO systems. The two cases of 1) generic, and 2) sparse channels is considered. The algorithms estimate the impulse response for each channel observed by the antennas at the receiver (base station) in a coordinated manner by sharing minimal information among neighboring antennas. Simulations demonstrate the superior performance of the proposed methods as compared to other methods.

  2. Massive hemorrhage management-a best evidence topic report.

    Science.gov (United States)

    Vymazal, Tomas

    2015-01-01

    Massive hemorrhage remains a major cause of potentially preventable deaths. Better control of bleeding could improve survival rates by 10%-20%. Transfusion intervention concepts have been formulated in order to minimize acute traumatic coagulopathy. These interventions still have not been standardized and vary among medical centers. Based on a literature search using free term keywords and Medical Subject Heading (MeSH) index, we analyzed published articles addressing massive hemorrhage, component therapy, fresh whole blood, and fibrinogen from the year 2000 onward, in journals with impact factor >1.000, in Medline, PubMed, and Google Scholar. The evidence was grouped into topics including laboratory testing and transfusion interventions/viscoelastic assays vs standard laboratory tests, the effect of component therapy on patient outcome, the effect of warm fresh whole blood on patient outcome, and the effects of fibrinogen in severe bleeding. The obtained information was compared, evaluated, confronted, and was focused on to present an adequate and individual-based massive hemorrhage management approach. Viscoelastic whole-blood assays are superior to standard coagulation blood tests for the identification of coagulopathy and for guiding decisions on appropriate therapy in patients with severe bleeding. Replacement of plasma, red blood cells, platelets, and fibrinogen in a ratio of 1:1:1:1 has appeared to be the best substitution for lost whole blood. There is no evidence that cryoprecipitate improves the outcome of patients with severe hemorrhage. Current literature promotes the transfusion of warm fresh whole blood, which seems to be superior to the component therapy in certain clinical situations. Some authors recommend that fibrinogen and other coagulation factors be administered according to the viscoelastic attributes of the blood clot. This best-evidence topic report brings comprehensive information about massive hemorrhage management.

  3. TSE computers - A means for massively parallel computations

    Science.gov (United States)

    Strong, J. P., III

    1976-01-01

    A description is presented of hardware concepts for building a massively parallel processing system for two-dimensional data. The processing system is to use logic arrays of 128 x 128 elements which perform over 16 thousand operations simultaneously. Attention is given to image data, logic arrays, basic image logic functions, a prototype negator, an interleaver device, image logic circuits, and an image memory circuit.

  4. Probing Massive Black Hole Populations and Their Environments with LISA

    Science.gov (United States)

    Katz, Michael; Larson, Shane

    2018-01-01

    With the adoption of the LISA Mission Proposal by the European Space Agency in response to its call for L3 mission concepts, gravitational wave measurements from space are on the horizon. With data from the Illustris large-scale cosmological simulation, we provide analysis of LISA detection rates accompanied by characterization of the merging Massive Black Holes (MBH) and their host galaxies. MBHs of total mass $\\sim10^6-10^9 M_\\odot$ are the main focus of this study. Using a precise treatment of the dynamical friction evolutionary process prior to gravitational wave emission, we evolve MBH simulation particle mergers from $\\sim$kpc scales until coalescence to achieve a merger distribution. Using the statistical basis of the Illustris output, we Monte-carlo synthesize many realizations of the merging massive black hole population across space and time. We use those realizations to build mock LISA detection catalogs to understand the impact of LISA mission configurations on our ability to probe massive black hole merger populations and their environments throughout the visible Universe.

  5. Relativistic N-body simulations with massive neutrinos

    Science.gov (United States)

    Adamek, Julian; Durrer, Ruth; Kunz, Martin

    2017-11-01

    Some of the dark matter in the Universe is made up of massive neutrinos. Their impact on the formation of large scale structure can be used to determine their absolute mass scale from cosmology, but to this end accurate numerical simulations have to be developed. Due to their relativistic nature, neutrinos pose additional challenges when one tries to include them in N-body simulations that are traditionally based on Newtonian physics. Here we present the first numerical study of massive neutrinos that uses a fully relativistic approach. Our N-body code, gevolution, is based on a weak-field formulation of general relativity that naturally provides a self-consistent framework for relativistic particle species. This allows us to model neutrinos from first principles, without invoking any ad-hoc recipes. Our simulation suite comprises some of the largest neutrino simulations performed to date. We study the effect of massive neutrinos on the nonlinear power spectra and the halo mass function, focusing on the interesting mass range between 0.06 eV and 0.3 eV and including a case for an inverted mass hierarchy.

  6. Does massive intraabdominal free gas require surgical intervention?

    Science.gov (United States)

    Furihata, Tadashi; Furihata, Makoto; Ishikawa, Kunibumi; Kosaka, Masato; Satoh, Naoki; Kubota, Keiichi

    2016-01-01

    We describe a rare case of an 81-year-old man who presented with severe epigastralgia. A chest radiograph showed massive free gas bilaterally in the diaphragmatic spaces. Computed tomography (CT) scan also showed massive free gas in the peritoneal cavity with portal venous gas. We used a wait-and-see approach and carefully considered surgery again when the time was appropriate. The patient received conservative therapy with fasting, an intravenous infusion of antibiotics, and nasogastric intubation. The patient soon recovered and was able to start eating meals 4 d after treatment; thus, surgical intervention was avoided. Thereafter, colonoscopy examination showed pneumatosis cystoides intestinalis in the ascending colon. On retrospective review, CT scan demonstrated sporadic air-filled cysts in the ascending colon. The present case taught us a lesson: the presence of massive intraabdominal free gas with portal venous gas does not necessarily require surgical intervention. Pneumatosis cystoides intestinalis should be considered as a potential causative factor of free gas with portal venous gas when making the differential diagnosis. PMID:27621584

  7. Black-hole-regulated star formation in massive galaxies

    Science.gov (United States)

    Martín-Navarro, Ignacio; Brodie, Jean P.; Romanowsky, Aaron J.; Ruiz-Lara, Tomás; van de Ven, Glenn

    2018-01-01

    Supermassive black holes, with masses more than a million times that of the Sun, seem to inhabit the centres of all massive galaxies. Cosmologically motivated theories of galaxy formation require feedback from these supermassive black holes to regulate star formation. In the absence of such feedback, state-of-the-art numerical simulations fail to reproduce the number density and properties of massive galaxies in the local Universe. There is, however, no observational evidence of this strongly coupled coevolution between supermassive black holes and star formation, impeding our understanding of baryonic processes within galaxies. Here we report that the star formation histories of nearby massive galaxies, as measured from their integrated optical spectra, depend on the mass of the central supermassive black hole. Our results indicate that the black-hole mass scales with the gas cooling rate in the early Universe. The subsequent quenching of star formation takes place earlier and more efficiently in galaxies that host higher-mass central black holes. The observed relation between black-hole mass and star formation efficiency applies to all generations of stars formed throughout the life of a galaxy, revealing a continuous interplay between black-hole activity and baryon cooling.

  8. Black-hole-regulated star formation in massive galaxies.

    Science.gov (United States)

    Martín-Navarro, Ignacio; Brodie, Jean P; Romanowsky, Aaron J; Ruiz-Lara, Tomás; van de Ven, Glenn

    2018-01-18

    Supermassive black holes, with masses more than a million times that of the Sun, seem to inhabit the centres of all massive galaxies. Cosmologically motivated theories of galaxy formation require feedback from these supermassive black holes to regulate star formation. In the absence of such feedback, state-of-the-art numerical simulations fail to reproduce the number density and properties of massive galaxies in the local Universe. There is, however, no observational evidence of this strongly coupled coevolution between supermassive black holes and star formation, impeding our understanding of baryonic processes within galaxies. Here we report that the star formation histories of nearby massive galaxies, as measured from their integrated optical spectra, depend on the mass of the central supermassive black hole. Our results indicate that the black-hole mass scales with the gas cooling rate in the early Universe. The subsequent quenching of star formation takes place earlier and more efficiently in galaxies that host higher-mass central black holes. The observed relation between black-hole mass and star formation efficiency applies to all generations of stars formed throughout the life of a galaxy, revealing a continuous interplay between black-hole activity and baryon cooling.

  9. [Interventional treatment of massive hemorrhage after percutaneous nephrolithotomy].

    Science.gov (United States)

    Zhao, Yilei; Zhong, Baishu; Xu, Shunliang; Shen, Bohua; Tan, Fuqing

    2014-08-13

    To explore the diagnostic and therapeutic measures of massive hemorrhage after percutaneous nephrolithotomy (PCNL) unresponsive to conservative treatment. The clinical data of 36 cases of massive hemorrhage occurring after PCNL from January 2010 to January 2014 at our hospital were analyzed. There were 21 males and 15 females with an average age of 46.7 years. There were left (n = 22) and right (n = 14) cases. Severe hemorrhage had an average onset of Days 3-4 (range, 1 to 7) after PCNL. Clinical manifestations included a drainage of fresh red blood liquids out of kidney fistula accompanied by red gross hematuria. Conservative measures were ineffective. On computed tomography angiography (CTA), pseudoaneurysm (n = 22) and arteriovenous fistula (n = 5) were found. Digital subtraction angiography (DSA) and coil embolization were successfully performed in 27 cases whose hemorrhage stopped in 1-3 days after embolization and kidney function returned to normal. Another 9 cases had no obvious hemorrhage on CTA. And venous hemorrhage was considered and conservative treatment succeeded. Renal arterial CTA is an ideal for assessing massive hemorrhage after PCNL unresponsive to conservative treatment. DSA and coil embolization are the preferred treatments.

  10. Shifting from Stewardship to Analytics of Massive Science Data

    Science.gov (United States)

    Crichton, D. J.; Doyle, R.; Law, E.; Hughes, S.; Huang, T.; Mahabal, A.

    2015-12-01

    Currently, the analysis of large data collections is executed through traditional computational and data analysis approaches, which require users to bring data to their desktops and perform local data analysis. Data collection, archiving and analysis from future remote sensing missions, be it from earth science satellites, planetary robotic missions, or massive radio observatories may not scale as more capable instruments stress existing architectural approaches and systems due to more continuous data streams, data from multiple observational platforms, and measurements and models from different agencies. A new paradigm is needed in order to increase the productivity and effectiveness of scientific data analysis. This paradigm must recognize that architectural choices, data processing, management, analysis, etc are interrelated, and must be carefully coordinated in any system that aims to allow efficient, interactive scientific exploration and discovery to exploit massive data collections. Future observational systems, including satellite and airborne experiments, and research in climate modeling will significantly increase the size of the data requiring new methodological approaches towards data analytics where users can more effectively interact with the data and apply automated mechanisms for data reduction, reduction and fusion across these massive data repositories. This presentation will discuss architecture, use cases, and approaches for developing a big data analytics strategy across multiple science disciplines.

  11. The Role of Rotation in the Evolution of Massive Stars

    Science.gov (United States)

    Heap, Sara R.; Lanz, Thierry M.

    2003-01-01

    Recent evolutionary models of massive stars predict important effects of rotation including: increasing the rate of mass loss; lowering the effective gravity; altering the evolutionary track on the Hertzsprung-Russel Diagram (HRD); extending the main-sequence phase (both on the HR diagram and in time); and mixing of CNO-processed elements up to the stellar surface. Observations suggest that rotation is a more important factor at lower metallicities because of higher initial rotational velocities and weaker winds. This makes the Small Magellanic Cloud (SMC), a low-metallicity galaxy (Z=0.2 solar Z), an excellent environment for discerning the role of rotation in massive stars. We report on a FUSE+STIS+optical spectral analysis of 17 O-type stars in the SMC, where we found an enormous range in N abundances. Three stars in the sample have the same (low) CN abundances as the nebular material out of which they formed, namely C=0.085 solar C and N=0.034 solar N. However, more than half show N approx. solar N, an enrichment factor of 30X! Such unexpectedly high levels of N have ramifications for the evolution of massive stars including precursors to supernovae. They also raise questions about the sources of nitrogen in the early universe. This study was supported in part by grants from NASA's ADP, HST GO-7437, and FUSE B134.

  12. Thought Leaders during Crises in Massive Social Networks

    Energy Technology Data Exchange (ETDEWEB)

    Corley, Courtney D.; Farber, Robert M.; Reynolds, William

    2012-05-24

    The vast amount of social media data that can be gathered from the internet coupled with workflows that utilize both commodity systems and massively parallel supercomputers, such as the Cray XMT, open new vistas for research to support health, defense, and national security. Computer technology now enables the analysis of graph structures containing more than 4 billion vertices joined by 34 billion edges along with metrics and massively parallel algorithms that exhibit near-linear scalability according to number of processors. The challenge lies in making this massive data and analysis comprehensible to an analyst and end-users that require actionable knowledge to carry out their duties. Simply stated, we have developed language and content agnostic techniques to reduce large graphs built from vast media corpora into forms people can understand. Specifically, our tools and metrics act as a survey tool to identify thought leaders' -- those members that lead or reflect the thoughts and opinions of an online community, independent of the source language.

  13. CHaMP: From Molecular Clouds to Massive Young Clusters

    Science.gov (United States)

    Barnes, Peter J.

    2017-03-01

    I review the major science outcomes to date of the Galactic Census of High- and Medium-mass Protostars (CHaMP), and also report the latest observational results on this unbiased, uniform sample of massive, cluster-forming molecular clumps, based on new mm-wave and IR data. These clouds represent the vast, subthermally-excited population of clumps predicted by Narayanan et al. (2008) to dominate the molecular mass of disk galaxies. Besides confirming their existence, we have presented evidence that these massive clumps probably spend a large fraction (90-95%) of their long lives (possibly up to 100 Myr) in a mostly quiescent, low star formation rate (SFR) state. This is likely ended when a density or internal pressure threshold is crossed, after which vigorous, massive cluster formation consumes the densest gas with a high SFR, dispersing the embedding envelope. New results presented in two other posters at this Symposium include (1) the first analysis of HCN emission from the dense gas (Schap et al. 2015), and (2) the first deep photometry of clusters in this sample based on NIR AAT & CTIO data, and on MIR Warm Spitzer IRAC data (Dallilar et al. 2015).

  14. Large-Scale CFD Parallel Computing Dealing with Massive Mesh

    Directory of Open Access Journals (Sweden)

    Zhi Shang

    2013-01-01

    Full Text Available In order to run CFD codes more efficiently on large scales, the parallel computing has to be employed. For example, in industrial scales, it usually uses tens of thousands of mesh cells to capture the details of complex geometries. How to distribute these mesh cells among the multiprocessors for obtaining a good parallel computing performance (HPC is really a challenge. Due to dealing with the massive mesh cells, it is difficult for the CFD codes without parallel optimizations to handle this kind of large-scale computing. Some of the open source mesh partitioning software packages, such as Metis, ParMetis, Scotch, PT-Scotch, and Zoltan, are able to deal with the distribution of large number of mesh cells. Therefore they were employed as the parallel optimization tools ported into Code_Saturne, an open source CFD code, for testing if they can solve the issue of dealing with massive mesh cells for CFD codes. Through the studies, it was found that the mesh partitioning optimization software packages can help CFD codes not only deal with massive mesh cells but also have a good HPC.

  15. Helicity decoupling in the massless limit of massive tensor fields

    Directory of Open Access Journals (Sweden)

    Jens Mund

    2017-11-01

    Full Text Available Massive and massless potentials play an essential role in the perturbative formulation of particle interactions. Many difficulties arise due to the indefinite metric in gauge theoretic approaches, or the increase with the spin of the UV dimension of massive potentials. All these problems can be evaded in one stroke: modify the potentials by suitable terms that leave unchanged the field strengths, but are not polynomial in the momenta. This feature implies a weaker localization property: the potentials are “string-localized”. In this setting, several old issues can be solved directly in the physical Hilbert space of the respective particles: We can control the separation of helicities in the massless limit of higher spin fields and conversely we recover massive potentials with 2s+1 degrees of freedom by a smooth deformation of the massless potentials (“fattening”. We construct stress–energy tensors for massless fields of any helicity (thus evading the Weinberg–Witten theorem. We arrive at a simple understanding of the van Dam–Veltman–Zakharov discontinuity concerning, e.g., the distinction between a massless or a very light graviton. Finally, the use of string-localized fields opens new perspectives for interacting quantum field theories with, e.g., vector bosons or gravitons.

  16. MAX-SLNR Precoding Algorithm for Massive MIMO System

    Directory of Open Access Journals (Sweden)

    Jiang Jing

    2016-01-01

    Full Text Available Pilot Contamination obviously degrades the system performance of Massive MIMO systems. In this paper, a downlink precoding algorithm based on the Signal-to- Leakage-plus-Noise-Ratio (SLNR criterion is put forward. First, the impact of Pilot Contamination on SLNR is analyzed,then the precoding matrix is calculated with the eigenvalues decomposition of SLNR, which not only maximize the array gains of the target user, but also minimize the impact of Pilot Contamination and the leak to the users of other cells. Further, a simplified solution is derived, in which the impact of Pilot Contamination can be suppressed only with the large-scale fading coefficients. Simulation results reveal that: in the scenario of the serious pilot contamination, the proposed algorithm can avoid the performance loss caused by the pilot contamination compared with the conventional Massive MIMO precoding algorithm. Thus the proposed algorithm can acquire the perfect performance gains of Massive MIMO system and has better practical value since the large-scale fading coefficients are easy to measure and feedback.

  17. Split Octonion Reformulation for Electromagnetic Chiral Media of Massive Dyons

    Science.gov (United States)

    Chanyal, B. C.

    2017-12-01

    In an explicit, unified, and covariant formulation of an octonion algebra, we study and generalize the electromagnetic chiral fields equations of massive dyons with the split octonionic representation. Starting with 2×2 Zorn’s vector matrix realization of split-octonion and its dual Euclidean spaces, we represent the unified structure of split octonionic electric and magnetic induction vectors for chiral media. As such, in present paper, we describe the chiral parameter and pairing constants in terms of split octonionic matrix representation of Drude-Born-Fedorov constitutive relations. We have expressed a split octonionic electromagnetic field vector for chiral media, which exhibits the unified field structure of electric and magnetic chiral fields of dyons. The beauty of split octonionic representation of Zorn vector matrix realization is that, the every scalar and vector components have its own meaning in the generalized chiral electromagnetism of dyons. Correspondingly, we obtained the alternative form of generalized Proca–Maxwell’s equations of massive dyons in chiral media. Furthermore, the continuity equations, Poynting theorem and wave propagation for generalized electromagnetic fields of chiral media of massive dyons are established by split octonionic form of Zorn vector matrix algebra.

  18. Horndeski extension of the minimal theory of quasidilaton massive gravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele

    2017-11-01

    The minimal theory of quasidilaton massive gravity allows for a stable self-accelerating de Sitter solution in a wide range of parameters. On the other hand, in order for the theory to be compatible with local gravity tests, the fifth force due to the quasidilaton scalar needs to be screened at local scales. The present paper thus extends the theory by inclusion of a cubic Horndeski term in a way that (i) respects the quasidilaton global symmetry, that (ii) maintains the physical degrees of freedom in the theory being 3, that (iii) can accommodate the Vainshtein screening mechanism, and that (iv) still allows for a stable self-accelerating de Sitter solution. After adding the Horndeski term (and a k -essence type nonlinear kinetic term as well) to the precursor action, we switch to the Hamiltonian language and find a complete set of independent constraints. We then construct the minimal theory with 3 physical degrees of freedom by carefully adding a pair of constraints to the total Hamiltonian of the precursor theory. Switching back to the Lagrangian language, we study cosmological solutions and their stability in the minimal theory. In particular, we show that a self-accelerating de Sitter solution is stable for a wide range of parameters. Furthermore, as in the minimal theory of massive gravity, the propagation speed of the massive gravitational waves in the high momentum limit precisely agrees with the speed of light.

  19. Increasing the reach of forensic genetics with massively parallel sequencing.

    Science.gov (United States)

    Budowle, Bruce; Schmedes, Sarah E; Wendt, Frank R

    2017-09-01

    The field of forensic genetics has made great strides in the analysis of biological evidence related to criminal and civil matters. More so, the discipline has set a standard of performance and quality in the forensic sciences. The advent of massively parallel sequencing will allow the field to expand its capabilities substantially. This review describes the salient features of massively parallel sequencing and how it can impact forensic genetics. The features of this technology offer increased number and types of genetic markers that can be analyzed, higher throughput of samples, and the capability of targeting different organisms, all by one unifying methodology. While there are many applications, three are described where massively parallel sequencing will have immediate impact: molecular autopsy, microbial forensics and differentiation of monozygotic twins. The intent of this review is to expose the forensic science community to the potential enhancements that have or are soon to arrive and demonstrate the continued expansion the field of forensic genetics and its service in the investigation of legal matters.

  20. Spontaneous massive hemopneumothorax: Double trouble with a twist

    Directory of Open Access Journals (Sweden)

    Milta Kuriakose

    2017-01-01

    Full Text Available Spontaneous hemopneumothorax (SHP is observed in 3%–7% cases of spontaneous pneumothorax where the tear of an adhesion can lead to bleeding with associated hemothorax. This condition has been reported in patients with hemophilia, sarcoidosis, congenital cystic adenomatoid malformation, systemic lupus erythematosus, etc., Here, we describe an unusual case of acute massive SHP in a 62-year-old male who underwent a percutaneous transluminal coronary angioplasty (PTCA and presented with worsening dyspnea over the next 3 days. On evaluation, he had a massive hemopneumothorax which was considered to be secondary to the use of anticoagulants during the PTCA procedure. Pleural fluid analysis revealed frank blood and was consistent with the diagnosis of hemothorax. Surprisingly, the pleural fluid cytology revealed malignant cells. As the patient had a normal chest X-ray 3 days ago, thoracoscopic pleural biopsy was taken which confirmed the diagnosis of an epithelioid mesothelioma. Although post-PTCA or mesothelioma-associated hemothorax has been rarely reported, these two conditions have not been associated with SHP. Since the patient had no prior clinicoradiological features of mesothelioma, the procedure, and the anticoagulants probably contributed to the massive and rapid accumulation of blood. The presence of small amount of air added further confusion to the dual etiology and has not been described earlier.

  1. 3D seismic imaging on massively parallel computers

    Energy Technology Data Exchange (ETDEWEB)

    Womble, D.E.; Ober, C.C.; Oldfield, R.

    1997-02-01

    The ability to image complex geologies such as salt domes in the Gulf of Mexico and thrusts in mountainous regions is a key to reducing the risk and cost associated with oil and gas exploration. Imaging these structures, however, is computationally expensive. Datasets can be terabytes in size, and the processing time required for the multiple iterations needed to produce a velocity model can take months, even with the massively parallel computers available today. Some algorithms, such as 3D, finite-difference, prestack, depth migration remain beyond the capacity of production seismic processing. Massively parallel processors (MPPs) and algorithms research are the tools that will enable this project to provide new seismic processing capabilities to the oil and gas industry. The goals of this work are to (1) develop finite-difference algorithms for 3D, prestack, depth migration; (2) develop efficient computational approaches for seismic imaging and for processing terabyte datasets on massively parallel computers; and (3) develop a modular, portable, seismic imaging code.

  2. Evolution of rapidly rotating metal-poor massive stars towards gamma-ray bursts

    NARCIS (Netherlands)

    Yoon, S.-C.; Langer, N.

    2005-01-01

    Recent models of rotating massive stars including magnetic fields prove it difficult for the cores of single stars to retain enough angular momentum to produce a collapsar and gamma-ray burst. At low metallicity, even very massive stars may retain a massive hydrogen envelope due to the weakness of

  3. Peculiarities of massive vector mesons and their zero mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert, E-mail: schroer@zedat.fu-berlin.de [CBPF, Rua Dr. Xavier Sigaud 150, 22290-180, Rio de Janeiro (Brazil); Institut für Theoretische Physik, FU-Berlin, Arnimallee 14, 14195, Berlin (Germany)

    2015-08-12

    Massive QED, in contrast with its massless counterpart, possesses two conserved charges; one is a screened (vanishing) Maxwell charge which is directly associated with the massive vector mesons through the identically conserved Maxwell current, while the presence of a particle-antiparticle counting charge depends on the matter. A somewhat peculiar situation arises for couplings of Hermitian matter fields to massive vector potentials; in that case the only current is the screened Maxwell current and the coupling disappears in the massless limit. In the case of self-interacting massive vector mesons the situation becomes even more peculiar in that the usually renormalizability guaranteeing validity of the first order power-counting criterion breaks down in second order and requires the compensatory presence of additional Hermitian H-fields. Some aspect of these observation have already been noticed in the BRST gauge theoretic formulation, but here we use a new setting based on string-local vector mesons which is required by Hilbert space positivity (“off-shell unitarity”). This new formulation explains why spontaneous symmetry breaking cannot occur in the presence of higher spin s≥1 fields. The coupling to H-fields induces Mexican hat-like self-interactions; they are not imposed and bear no relation with spontaneous symmetry breaking; they are rather consequences of the foundational causal localization properties realized in a Hilbert space setting. In the case of self-interacting massive vector mesons their presence is required in order to maintain the first order power-counting restriction of renormalizability also in second order. The presentation of the new Hilbert space setting for vector mesons which replaces gauge theory and extends on-shell unitarity to its off-shell counterpart is the main motivation for this work. The new Hilbert space setting also shows that the second order Lie-algebra structure of self-interacting vector mesons is a consequence of

  4. Inferring the Growth of Massive Galaxies Using Bayesian Spectral Synthesis Modeling

    Science.gov (United States)

    Stillman, Coley Michael; Poremba, Megan R.; Moustakas, John

    2018-01-01

    The most massive galaxies in the universe are typically found at the centers of massive galaxy clusters. Studying these galaxies can provide valuable insight into the hierarchical growth of massive dark matter halos. One of the key challenges of measuring the stellar mass growth of massive galaxies is converting the measured light profiles into stellar mass. We use Prospector, a state-of-the-art Bayesian spectral synthesis modeling code, to infer the total stellar masses of a pilot sample of massive central galaxies selected from the Sloan Digital Sky Survey. We compare our stellar mass estimates to previous measurements, and present some of the quantitative diagnostics provided by Prospector.

  5. Investigation of the status quo of massive blood transfusion in China and a synopsis of the proposed guidelines for massive blood transfusion.

    Science.gov (United States)

    Yang, Jiang-Cun; Wang, Qiu-Shi; Dang, Qian-Li; Sun, Yang; Xu, Cui-Xiang; Jin, Zhan-Kui; Ma, Ting; Liu, Jing

    2017-08-01

    The aim of this study was to provide an overview of massive transfusion in Chinese hospitals, identify the important indications for massive transfusion and corrective therapies based on clinical evidence and supporting experimental studies, and propose guidelines for the management of massive transfusion. This multiregion, multicenter retrospective study involved a Massive Blood Transfusion Coordination Group composed of 50 clinical experts specializing in blood transfusion, cardiac surgery, anesthesiology, obstetrics, general surgery, and medical statistics from 20 tertiary general hospitals across 5 regions in China. Data were collected for all patients who received ≥10 U red blood cell transfusion within 24 hours in the participating hospitals from January 1 2009 to December 31 2010, including patient demographics, pre-, peri-, and post-operative clinical characteristics, laboratory test results before, during, and after transfusion, and patient mortality at post-transfusion and discharge. We also designed an in vitro hemodilution model to investigate the changes of blood coagulation indices during massive transfusion and the correction of coagulopathy through supplement blood components under different hemodilutions. The experimental data in combination with the clinical evidence were used to determine the optimal proportion and timing for blood component supplementation during massive transfusion. Based on the findings from the present study, together with an extensive review of domestic and international transfusion-related literature and consensus feedback from the 50 experts, we drafted the guidelines on massive blood transfusion that will help Chinese hospitals to develop standardized protocols for massive blood transfusion.

  6. Imaging findings of adiposis dolorosa vs. massive localized lymphedema

    Energy Technology Data Exchange (ETDEWEB)

    Petscavage-Thomas, Jonelle M.; Bernard, Stephanie A.; Bennett, Jennifer [Milton S. Hershey Medical Center, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Walker, Eric A. [Milton S. Hershey Medical Center, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Uniformed Services University of the Health Sciences, Department of Radiology and Nuclear Medicine, Bethesda, MD (United States)

    2015-06-01

    Adiposis dolorosa (Dercum's disease) is a condition of benign, painful subcutaneous lipomatous lesions associated with weakness, endocrine and lipid abnormalities, and mental disturbances. There is little information documenting the cross-sectional imaging findings that differentiate it from lipomatous and neoplastic soft tissue masses, or massive localized lymphedema. The purpose of this study was to provide a radiological case series of adiposis dolorosa. A 10-year retrospective review of the picture archiving and communications system was performed. Two musculoskeletal radiologists reviewed images to confirm and document imaging features, location, size, and patient demographics. Medical records were reviewed to characterize patients into three groups: one group met at least three of the four criteria of Dercum's syndrome, the second group met less than three criteria, and the third group had clinical diagnosis of cellulitis of the lower extremity. Seventeen cases (25 masses) of adiposis dolorosa were found, nine cases of which met at least three criteria of Dercum's syndrome. All cases in the first two groups demonstrated skin thickening and lymphedema of subcutaneous fat, which was fluid attenuation on CT and low or intermediate T1-weighted and high STIR/T2-weighted MR signal. Two cases with pathology showed mild fatty infiltration with fibrous septa, and the third case showed massive localized lymphedema. The third group of ten cellulitis patients demonstrated non-mass-like subcutaneous edema with similar CT attenuation and MR signal characteristics to the first two groups, but differed by the presence of post-contrast enhancement and non-mass-like appearance in 90 %. Imaging findings of adiposis dolorosa and massive localized lymphedema overlap, as do the symptoms and pathological features. Due to the mass-like engorgement of the soft tissues and pain, patients will often undergo imaging to exclude neoplasm or infection. Knowledge of these

  7. Periodic self-lensing from accreting massive black hole binaries

    Science.gov (United States)

    D'Orazio, Daniel J.; Di Stefano, Rosanne

    2018-03-01

    Nearly 150 massive black hole binary (MBHB) candidates at sub-pc orbital separations have been reported in recent literature. Nevertheless, the definitive detection of even a single such object remains elusive. If at least one of the black holes is accreting, the light emitted from its accretion disc will be lensed by the other black hole for binary orbital inclinations near to the line of sight. This binary self-lensing could provide a unique signature of compact MBHB systems. We show that, for MBHBs with masses in the range 106-1010 M⊙ and with orbital periods less than ˜10 yr, strong lensing events should occur in one to 10s of per cent of MBHB systems that are monitored for an entire orbit. Lensing events will last from days for the less massive, shorter period MBHBs to a year for the most massive ˜10 year orbital period MBHBs. At small inclinations of the binary orbit to the line of sight, lensing must occur and will be accompanied by periodicity due to the relativistic Doppler boost. Flares at the same phase as the otherwise average flux of the Doppler modulation would be a smoking gun signature of self-lensing and can be used to constrain binary parameters. For MBHBs with separation ≳100 Schwarzschild radii, we show that finite-sized source effects could serve as a probe of MBH accretion disc structure. Finally, we stress that our lensing probability estimate implies that ˜10 of the known MBHB candidates identified through quasar periodicity should exhibit strong lensing flares.

  8. Young and intermediate-age massive star clusters.

    Science.gov (United States)

    Larsen, Søren S

    2010-02-28

    An overview of our current understanding of the formation and evolution of star clusters is given, with the main emphasis on high-mass clusters. Clusters form deeply embedded within dense clouds of molecular gas. Left-over gas is cleared within a few million years and, depending on the efficiency of star formation, the clusters may disperse almost immediately or remain gravitationally bound. Current evidence suggests that a small percentage of star formation occurs in clusters that remain bound, although it is not yet clear whether this fraction is truly universal. Internal two-body relaxation and external shocks will lead to further, gradual dissolution on time scales of up to a few hundred million years for low-mass open clusters in the Milky Way, while the most massive clusters (>10(5) M(o)) have lifetimes comparable to or exceeding the age of the Universe. The low-mass end of the initial cluster mass function is well approximated by a power-law distribution, dN/dM proportional to M(-2), but there is mounting evidence that quiescent spiral discs form relatively few clusters with masses M > 2 x 10(5) M(o). In starburst galaxies and old globular cluster systems, this limit appears to be higher, at least several x10(6) M(o). The difference is likely related to the higher gas densities and pressures in starburst galaxies, which allow denser, more massive giant molecular clouds to form. Low-mass clusters may thus trace star formation quite universally, while the more long-lived, massive clusters appear to form preferentially in the context of violent star formation.

  9. A distance-limited sample of massive molecular outflows

    Science.gov (United States)

    Maud, L. T.; Moore, T. J. T.; Lumsden, S. L.; Mottram, J. C.; Urquhart, J. S.; Hoare, M. G.

    2015-10-01

    We have observed 99 mid-infrared-bright, massive young stellar objects and compact H II regions drawn from the Red MSX source survey in the J = 3-2 transition of 12CO and 13CO, using the James Clerk Maxwell Telescope. 89 targets are within 6 kpc of the Sun, covering a representative range of luminosities and core masses. These constitute a relatively unbiased sample of bipolar molecular outflows associated with massive star formation. Of these, 59, 17 and 13 sources (66, 19 and 15 per cent) are found to have outflows, show some evidence of outflow, and have no evidence of outflow, respectively. The time-dependent parameters of the high-velocity molecular flows are calculated using a spatially variable dynamic time-scale. The canonical correlations between the outflow parameters and source luminosity are recovered and shown to scale with those of low-mass sources. For coeval star formation, we find the scaling is consistent with all the protostars in an embedded cluster providing the outflow force, with massive stars up to ˜30 M⊙ generating outflows. Taken at face value, the results support the model of a scaled-up version of the accretion-related outflow-generation mechanism associated with discs and jets in low-mass objects with time-averaged accretion rates of ˜10-3 M⊙ yr-1 on to the cores. However, we also suggest an alternative model, in which the molecular outflow dynamics are dominated by the entrained mass and are unrelated to the details of the acceleration mechanism. We find no evidence that outflows contribute significantly to the turbulent kinetic energy of the surrounding dense cores.

  10. Massive splenomegaly in children: laparoscopic versus open splenectomy.

    Science.gov (United States)

    Hassan, Mohamed E; Al Ali, Khalid

    2014-01-01

    Laparoscopic splenectomy for massive splenomegaly is still a controversial procedure as compared with open splenectomy. We aimed to compare the feasibility of laparoscopic splenectomy versus open splenectomy for massive splenomegaly from different surgical aspects in children. The data of children aged splenectomy for hematologic disorders were retrospectively reviewed in 2 pediatric surgery centers from June 2004 until July 2012. The study included 32 patients, 12 who underwent laparoscopic splenectomy versus 20 who underwent open splenectomy. The mean ages were 8.5 years and 8 years in the laparoscopic splenectomy group and open splenectomy group, respectively. The mean operative time was 180 minutes for laparoscopic splenectomy and 120 minutes for open splenectomy. The conversion rate was 8%. The mean amount of intraoperative blood loss was 60 mL in the laparoscopic splenectomy group versus 110 mL in the open splenectomy group. Postoperative atelectasis developed in 2 cases in the open splenectomy group (10%) and 1 case in the laparoscopic splenectomy group (8%). Oral feeding postoperatively resumed at a mean of 7.5 hours in the laparoscopic splenectomy group versus 30 hours in the open splenectomy group. The mean hospital stay was 36 hours in the laparoscopic splenectomy group versus 96 hours in the open splenectomy group. Postoperative pain was less in the laparoscopic splenectomy group. Laparoscopic splenectomy for massive splenomegaly in children is safe and feasible. Although the operative time was significantly greater in the laparoscopic splenectomy group, laparoscopic splenectomy was associated with statistically significantly less pain, less blood loss, better recovery, and shorter hospital stay. Laparoscopic splenectomy for pediatric hematologic disorders should be the gold-standard approach regardless of the size of the spleen.

  11. Small bowel adaptation is dependent on site of massive enterectomy.

    Science.gov (United States)

    Wang, H T; Miller, J H; Avissar, N; Sax, H C

    1999-06-01

    Changes in amino acid transport after massive enterectomy occur in a nutrient-dependent fashion and may affect long-term outcome. Epidermal growth factor (EGF) can enhance nutrient transport and a defective epidermal growth factor receptor (EGF-R) has been noted to attenuate adaptation. Most animal studies, however, have examined only a single site of resection. This does not mimic the clinical situation where disease dictates the site of resection leading to proximal, middle, or distal enterectomies. We hypothesize that the site of massive enterectomy will alter nutrient transport and EGF-R levels in the residual gut. New Zealand White rabbits were randomized to control, midgut division, or 70% resection (proximal, midgut, or distal). After 1 week, sodium-dependent transport of glucose, glutamine, alanine, and leucine into brush border membrane vesicles was quantitated. EGF-R protein was determined by Western blot analysis. At baseline, amino acid transport was greater in ileum than jejunum. Surgery alone elevated glutamine and leucine jejunal transport by 130 and 97%, respectively, over controls (P < 0.05). Midgut resection increased jejunal glutamine transport 61% over control (P < 0.05). In contrast, distal resection increased jejunal alanine transport by 150% over controls with no change in glutamine (P < 0.05). After midgut resection, EGF-R was significantly greater (124%) in ileum then in jejunum in whole mucosa homogenates. Proximal resection significantly lowered ileal EGF-R compared to that seen in midgut resected residual ileum. Site of massive resection is important in determining postoperative changes in nutrient transport and EGF-R. Copyright 1999 Academic Press.

  12. Massive fetomaternal hemorrhage as a cause of severe fetal anemia

    Directory of Open Access Journals (Sweden)

    Dobrosavljević Aleksandar

    2016-01-01

    Full Text Available Introduction. Fetomaternal hemorrhage (FMH is a transfu-sion of fetal blood into the maternal circulation. A volume of transfused fetal blood required to cause severe, life-threatening fetal anemia, is not clearly defined. Some authors suggest vol-umes of 80 mL and 150 mL as a threshold which defines mas-sive FMH. Therefore, a rate of massive FMH is 1 : 1,000 and 1 : 5,000 births, respectively. Fetal and neonatal anemia is one of the most serious complications of the FMH. Clinical manifesta-tions of FMH are nonspecific, and mostly it presented as re-duced fetal movements and changes in cardiotocography (CTG. The standard for diagnosing FMH is Kleihaurer-Betke test. Case report. A 34-year-old gravida (G 1, para (P 1 was hospitalized due to uterine contractions at 39 weeks of gesta-tion. CTG monitoring revealed sinusoidal fetal heart rate and clinical examination showed complete cervical dilatation. Im-mediately after admission, the women delivered vaginally. Ap-gar scores were 1 and 2 at the first and fifth minute, respec-tively. Immediately baby was intubated and mechanical ventila-tion started. Initial analysis revealed pronounced acidosis and severe anemia. The patient received intravenous fluid therapy with sodium-bicarbonate as well as red cell transfusion. With all measures, the condition of the baby improved with normaliza-tion of hemoglobin level and blood pH. Kleihaurer-Betke test revealed the presence of fetal red cells in maternal circulation, equivalent to 531 mL blood loss. The level of maternal fetal hemoglobin (HbF and elevated alpha fetoprotein also con-firmed the diagnosis of massive FMH. Conclusion. For the successful diagnosis and management of FMH direct commu-nication between the obstetrician and the pediatrician is neces-sary as presented in this report.

  13. Determinants of mortality in trauma patients following massive blood transfusion

    Directory of Open Access Journals (Sweden)

    Rangarajan Kanchana

    2011-01-01

    Full Text Available Aim : This study was designed to find out the factors influencing mortality in trauma patients receiving massive blood transfusion (MBT. Materials and Methods : Records of all patients admitted during December 2007 to November 2008 at a Level I Trauma Center emergency and who underwent massive transfusion (≥10 units of packed red cells in 24 h were retrospectively analyzed. Death during the hospital stay was considered as the study outcome and various demographic, laboratory, and clinical parameters were included as its potential determinants. Statistical Analysis : Bivariate and multivariate logistic regression analyses were done to identify the risk factors associated with mortality. Results : Of the 4054 transfused patients who were admitted to the trauma center during the study period, 71 (1.8% patients underwent massive transfusion. Of this, there were 37 survivors and 34 nonsurvivors (48%. The median overall ISS was 27 (22-34. The patients who died had shorter mean length of hospital stay, shorter mean duration of intensive care unit (ICU stay, and low admission Glasgow Coma Scale (GCS compared to the survivors (P < 0.01. The mean prothrombin time (PT and the mean activated partial thromboplastin time was significantly high (P < 0.01 among nonsurvivors. Total leukocyte count (TLC ≥ 10,000 cells/cubic mm, GCS ≤ 8, the presence of coagulopathy and major vascular surgery were the four independent determinants of mortality in multivariate logistic regression analysis. The FFP:PRBC (fresh frozen plasma:packed red cells ratio and PC:PRBC (platelet concentrate:packed red cells ratio calculated in our study was not statistically significant in correlation to the in hospital mortality. Conclusions : Overall mortality among the MBT patients was comparable with the studies in the literature. Mortality is not affected by the amount of packed red cells given in the first 12 h and the total number of packed red cells transfused. Prospective

  14. [Ratio of erythrocyte and plasma in massive blood transfusion].

    Science.gov (United States)

    Wen, Xian-Hui; Liu, Feng-Xia; Zhang, Jun-Hua; Gui, Rong

    2014-06-01

    This study was purposed to explore the suitable ratio between fresh frozen plasma and erythrocyte by retrospective analysis of coagulation in patients with massive blood transfusion. The clinical data of 151 cases with massive blood transfusion from January 2011 to January 2013 were analyzed retrospectively. According to coagulation, patients were divided into coagulation normal group (138 cases) and coagulation dysfunction group (13 cases). Based on the ratio of 1:1 of fresh frozen plasma and erythrocyte, the patients were divided into high plasma group(2:1), medium plasma group (1:1) and low plasma (blood transfusion. The results showed that prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) were prolonged, fibrinogen (FIB) level decreased significantly (all P blood transfusion 24 h; the high plasma and the medium plasma group of coagulation normal group had no significant changes in coagulation (P > 0.05); prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen level in the medium plasma and low plasma subgroup of coagulation dysfunction group after massive transfusion was still in abnormal levels (P > 0.05), coagulation function in high plasma subgroup was improved significantly (P blood transfusion, the ratio between fresh frozen plasma and erythrocyte is recommended to be 2:1 in patients of coagulation dysfunction in order to improve the patient's coagulation function and to reduce the incidence of adverse event, the ratio of fresh frozen plasma to erythrocyte is recommended to be 1:1 in patients with normal coagulation so as to reduce the dilutional coagulopathy and hypervolemia of blood.

  15. Massive Open Online Courses: what will be their legacy?

    Science.gov (United States)

    Daniel, John

    2016-04-01

    Massive Open Online Courses (MOOCs) dominated discussions of online learning and higher education in the news media and in universities between 2012 and 2015. However, fashions pass, needs change and technology evolves. This Commentary looks back, pauses on the present, and then looks forward. Whilst MOOCs are a significant milestone on the road that online teaching and learning is following, open, distance and online learning started long before MOOCs and will continue to grow in importance when MOOCs are just an interesting footnote in its development. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Formation des etoiles massives dans les galaxies spirales

    Science.gov (United States)

    Lelievre, Mario

    Le but de cette thèse est de décrire la formation des étoiles massives dans les galaxies spirales appartenant à divers types morphologiques. L'imagerie Hα profonde combinée à une robuste méthode d'identification des régions HII ont permis de détecter et de mesurer les propriétés (position, taille, luminosité, taux de formation d'étoiles) de plusieurs régions HII situées dans le disque interne (R produire dans les galaxies.

  17. Routing performance analysis and optimization within a massively parallel computer

    Science.gov (United States)

    Archer, Charles Jens; Peters, Amanda; Pinnow, Kurt Walter; Swartz, Brent Allen

    2013-04-16

    An apparatus, program product and method optimize the operation of a massively parallel computer system by, in part, receiving actual performance data concerning an application executed by the plurality of interconnected nodes, and analyzing the actual performance data to identify an actual performance pattern. A desired performance pattern may be determined for the application, and an algorithm may be selected from among a plurality of algorithms stored within a memory, the algorithm being configured to achieve the desired performance pattern based on the actual performance data.

  18. Massive stars and the Canadian Galactic Plane Survey

    Science.gov (United States)

    Pineault, S.

    The Canadian Galactic Plane Survey is the first high angular resolution (about 1 arcminute at 1420 MHz) radio survey of part of the plane of our Galaxy. The radio survey is complemented by images in the four infrared bands of IRAS and by CO (J=1-0) molecular observations. After a brief description of the main properties of the survey, I present large-scale images of our Galaxy in total intensity, polarization and in the 21-cm line of HI, including some results related more specifically to massive stars (O and Wolf-Rayet stars, supernova remnants).

  19. CERVICAL ECTOPIC PREGNANCY WITH MASSIVE BLEEDING: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Slavcho Tomov

    2015-05-01

    Full Text Available A 29-year-old patient with cervical ectopic pregnancy (CEP presented as "suspected" cervical mass, and irregular vaginal bleeding was directed to a gynecologic oncologist for consultation. During the examination a massive bleeding occurred. After an unsuccessful attempt to stop the bleeding with a balloon catheter and vaginal tamponade, a total abdominal hysterectomy was performed. The predisposing factors, the differential diagnostic possibilities and the clinical approaches in CEP are discussed. Total abdominal hysterectomy is the procedure of choice for treatment of cervical pregnancy under conditions of urgency and life-threatening bleeding.

  20. Exploring the Potential of the Massive, Open, Online Astronomy Course

    Science.gov (United States)

    Austin, Carmen; Impey, C. D.; Wenger, M.

    2014-01-01

    Astronomy: State of the Art is a massive, open, online course (MOOC) in astronomy. Course content was released weekly, over 7 weeks, in the spring of 2013. More than 10 hours of video lectures were produced and deployed along with supplementary readings, podcasts, and realtime Q&A sessions with professor Chris Impey. All content is still available online as a self-paced course. Over 5,000 students have enrolled in the course through the online course platform Udemy. This poster presents student engagement data, and a discussion of lessons learned and opportunities for future improvement.

  1. Vacuum degeneracy in massive gravity: Multiplicity of fundamental scales

    Science.gov (United States)

    Arraut, Ivan; Chelabi, Kaddour

    2017-07-01

    The presence of Nambu-Goldstone bosons introduce a natural degeneracy inside the vacuum solutions of the nonlinear formulations of massive gravity in the same spirit of the σ-models. When the gravitational effects are taken into account, and the observers are located at any distance with respect to the source, this degeneracy corresponds to a multiplicity (flow) of the fundamental scales of the theory. The different values of the fundamental scales are connected to each other through the broken generators of the theory.

  2. A massive thermal detector for alpha and gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Alessandrello, A.; Brofferio, C.; Cremonesi, O.; Fiorini, E. E-mail: ettore.fiorini@mi.infn.it; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pirro, S.; Pessina, G.; Parmeggiano, S.; Previtali, E.; Vanzini, M.; Zanotti, L.; Coccia, E.; Fafone, V.; Bucci, C.; Rotilio, A

    2000-02-01

    A massive bolometer with a 760 g TeO{sub 2} crystal as energy absorber, the largest employed underground, has been realized and operated in the Gran Sasso Underground Laboratory for {gamma}- and {alpha}-ray spectroscopy. A new system of mechanical suspensions was implemented to reduce vibration and thermal noise, and special care was put to the read-out electronics. As a consequence the FWHM resolution for high-energy {gamma}-rays became comparable to that of Germanium diodes. The 4.2 keV average FWHM resolution for the 5407 keV line is the best ever obtained for {alpha} particles with any type of detector.

  3. A massive thermal detector for alpha and gamma spectroscopy

    Science.gov (United States)

    Alessandrello, A.; Brofferio, C.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pirro, S.; Pessina, G.; Parmeggiano, S.; Previtali, E.; Vanzini, M.; Zanotti, L.; Coccia, E.; Fafone, V.; Bucci, C.; Rotilio, A.

    2000-02-01

    A massive bolometer with a 760 g TeO 2 crystal as energy absorber, the largest employed underground, has been realized and operated in the Gran Sasso Underground Laboratory for γ- and α-ray spectroscopy. A new system of mechanical suspensions was implemented to reduce vibration and thermal noise, and special care was put to the read-out electronics. As a consequence the FWHM resolution for high-energy γ-rays became comparable to that of Germanium diodes. The 4.2 keV average FWHM resolution for the 5407 keV line is the best ever obtained for α particles with any type of detector.

  4. Solar-like oscillations in a massive star.

    Science.gov (United States)

    Belkacem, Kévin; Samadi, Réza; Goupil, Marie-Jo; Lefèvre, Laure; Baudin, Fréderic; Deheuvels, Sébastien; Dupret, Marc-Antoine; Appourchaux, Thierry; Scuflaire, Richard; Auvergne, Michel; Catala, Claude; Michel, Eric; Miglio, Andrea; Montalban, Josefina; Thoul, Anne; Talon, Suzanne; Baglin, Annie; Noels, Arlette

    2009-06-19

    Seismology of stars provides insight into the physical mechanisms taking place in their interior, with modes of oscillation probing different layers. Low-amplitude acoustic oscillations excited by turbulent convection were detected four decades ago in the Sun and more recently in low-mass main-sequence stars. Using data gathered by the Convection Rotation and Planetary Transits mission, we report here on the detection of solar-like oscillations in a massive star, V1449 Aql, which is a known large-amplitude (beta Cephei) pulsator.

  5. The quest for magnetic massive stars in the Magellanic Clouds

    Science.gov (United States)

    Nazé, Y.; Bagnulo, S.; Walborn, N. R.; Morrell, N.; Wade, G. A.; Szymanski, M. K.; Townsend, R. H. D.

    2017-11-01

    The Of?p category was introduced more than 40 years ago to gather several Galactic stars with some odd properties. Since 2000, spectropolarimetry, high-resolution spectroscopy, long-term photometry, and X-ray observations have revealed their nature: magnetic oblique rotators - they all have magnetic fields that confine their winds. Several Of?p stars have now been detected in the Magellanic Clouds, likely the prototypes of magnetic massive stars at low metallicity. This contribution will present the most recent photometric, spectroscopic, and spectropolarimetric data, along with the first modeling of these objects.

  6. RCW 108: Massive Young Stars Trigger Stellar Birth

    Science.gov (United States)

    2008-01-01

    RCW 108 is a region where stars are actively forming within the Milky Way galaxy about 4,000 light years from Earth. This is a complicated region that contains young star clusters, including one that is deeply embedded in a cloud of molecular hydrogen. By using data from different telescopes, astronomers determined that star birth in this region is being triggered by the effect of nearby, massive young stars. This image is a composite of X-ray data from NASA's Chandra X-ray Observatory (blue) and infrared emission detected by NASA's Spitzer Space Telescope (red and orange). More than 400 X-ray sources were identified in Chandra's observations of RCW 108. About 90 percent of these X-ray sources are thought to be part of the cluster and not stars that lie in the field-of-view either behind or in front of it. Many of the stars in RCW 108 are experiencing the violent flaring seen in other young star-forming regions such as the Orion nebula. Gas and dust blocks much of the X-rays from the juvenile stars located in the center of the image, explaining the relative dearth of Chandra sources in this part of the image. The Spitzer data show the location of the embedded star cluster, which appears as the bright knot of red and orange just to the left of the center of the image. Some stars from a larger cluster, known as NGC 6193, are also visible on the left side of the image. Astronomers think that the dense clouds within RCW 108 are in the process of being destroyed by intense radiation emanating from hot and massive stars in NGC 6193. Taken together, the Chandra and Spitzer data indicate that there are more massive star candidates than expected in several areas of this image. This suggests that pockets within RCW 108 underwent localized episodes of star formation. Scientists predict that this type of star formation is triggered by the effects of radiation from bright, massive stars such as those in NGC 6193. This radiation may cause the interior of gas clouds in RCW 108 to

  7. Massive pre-main-sequence stars in M17

    Science.gov (United States)

    Ramírez-Tannus, M. C.; Kaper, L.; de Koter, A.; Tramper, F.; Bik, A.; Ellerbroek, L. E.; Ochsendorf, B. B.; Ramírez-Agudelo, O. H.; Sana, H.

    2017-08-01

    The formation process of massive stars is still poorly understood. Massive young stellar objects (mYSOs) are deeply embedded in their parental clouds; these objects are rare, and thus typically distant, and their reddened spectra usually preclude the determination of their photospheric parameters. M17 is one of the best-studied H ii regions in the sky, is relatively nearby, and hosts a young stellar population. We have obtained optical to near-infrared spectra of previously identified candidate mYSOs and a few OB stars in this region with X-shooter on the ESO Very Large Telescope. The large wavelength coverage enables a detailed spectroscopic analysis of the photospheres and circumstellar disks of these candidate mYSOs. We confirm the pre-main-sequence (PMS) nature of six of the stars and characterise the O stars. The PMS stars have radii that are consistent with being contracting towards the main sequence and are surrounded by a remnant accretion disk. The observed infrared excess and the double-peaked emission lines provide an opportunity to measure structured velocity profiles in the disks. We compare the observed properties of this unique sample of young massive stars with evolutionary tracks of massive protostars and propose that these mYSOs near the western edge of the H ii region are on their way to become main-sequence stars ( 6-20 M⊙) after having undergone high mass accretion rates (Ṁacc 10-4-10-3M⊙yr-1). Their spin distribution upon arrival at the zero age main-sequence is consistent with that observed for young B stars, assuming conservation of angular momentum and homologous contraction. Based on observations collected at the European Southern Observatory at Paranal, Chile (ESO programmes 60.A-9404(A), 085.D-0741, 089.C-0874(A), and 091.C-0934(B)).The full normalised X-shooter spectra are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A78

  8. Body Contouring Surgery in the Massive Weight Loss Patient.

    Science.gov (United States)

    Hurwitz, Dennis J; Ayeni, Omodele

    2016-08-01

    Plastic surgeons subspecializing in body contouring are meeting the challenge of postbariatric surgery massive weight loss patients. With an appreciation of the magnitude of the surface deformity, and altered metabolism, nutrition, and psychological makeup of these patients, innovative plastic surgeons have forged an organized approach to preparation, operative technique, and postoperative care. Patients at greatest risk for complications are identified, appraised, and either their condition improved or they are counselled to reduce expectations. Beyond the removal of excess skin and adipose tissue, advanced gender-specific techniques have improved aesthetics. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Full NLO massive gauge boson pair production at the LHC

    CERN Document Server

    Baglio, Julien; Weber, Marcus M

    2013-01-01

    Electroweak gauge boson pair production is a very important process at the LHC as it probes the non-abelian structure of electroweak interactions and is a background process for many searches. We present full next-to-leading order predictions for the production cross sections and distributions of on-shell massive gauge boson pair production in the Standard Model, including both QCD and electroweak corrections. The hierarchy between the ZZ, WW and WZ channels, observed in the transverse momentum distributions, will be analyzed. We will also present a comparison with experimental data for the total cross sections including a study of the theoretical uncertainties.

  10. A Massive Prestellar Clump Hosting No High-mass Cores

    Energy Technology Data Exchange (ETDEWEB)

    Sanhueza, Patricio; Lu, Xing; Tatematsu, Ken’ichi [National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Jackson, James M. [School of Mathematical and Physical Sciences, University of Newcastle, University Drive, Callaghan, NSW 2308 (Australia); Zhang, Qizhou; Stephens, Ian W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Guzmán, Andrés E. [Departamento de Astronomía, Universidad de Chile, Camino el Observatorio 1515, Las Condes, Santiago (Chile); Wang, Ke, E-mail: patricio.sanhueza@nao.ac.jp [European Southern Observatory (ESO) Headquarters, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)

    2017-06-01

    The infrared dark cloud (IRDC) G028.23-00.19 hosts a massive (1500 M {sub ⊙}), cold (12 K), and 3.6–70 μ m IR dark clump (MM1) that has the potential to form high-mass stars. We observed this prestellar clump candidate with the Submillimeter Array (∼3.″5 resolution) and Jansky Very Large Array (∼2.″1 resolution) in order to characterize the early stages of high-mass star formation and to constrain theoretical models. Dust emission at 1.3 mm wavelength reveals five cores with masses ≤15 M {sub ⊙}. None of the cores currently have the mass reservoir to form a high-mass star in the prestellar phase. If the MM1 clump will ultimately form high-mass stars, its embedded cores must gather a significant amount of additional mass over time. No molecular outflows are detected in the CO (2-1) and SiO (5-4) transitions, suggesting that the SMA cores are starless. By using the NH{sub 3} (1, 1) line, the velocity dispersion of the gas is determined to be transonic or mildly supersonic (Δ V {sub nt}/Δ V {sub th} ∼ 1.1–1.8). The cores are not highly supersonic as some theories of high-mass star formation predict. The embedded cores are four to seven times more massive than the clump thermal Jeans mass and the most massive core (SMA1) is nine times less massive than the clump turbulent Jeans mass. These values indicate that neither thermal pressure nor turbulent pressure dominates the fragmentation of MM1. The low virial parameters of the cores (0.1–0.5) suggest that they are not in virial equilibrium, unless strong magnetic fields of ∼1–2 mG are present. We discuss high-mass star formation scenarios in a context based on IRDC G028.23-00.19, a study case believed to represent the initial fragmentation of molecular clouds that will form high-mass stars.

  11. Contact-impact simulations on massively parallel SIMD supercomputers

    Energy Technology Data Exchange (ETDEWEB)

    Plaskacz, E. J. [Argonne National Lab., IL (United States); Belytscko, T.; Chiang, H. Y. [Northwestern Univ., Evanston, IL (United States)

    1992-01-01

    The implementation of explicit finite element methods with contact-impact on massively parallel SIMD computers is described. The basic parallel finite element algorithm employs an exchange process which minimizes interprocessor communication at the expense of redundant computations and storage. The contact-impact algorithm is based on the pinball method in which compatibility is enforced by preventing interpenetration on spheres embedded in elements adjacent to surfaces. The enhancements to the pinball algorithm include a parallel assembled surface normal algorithm and a parallel detection of interpenetrating pairs. Some timings with and without contact-impact are given.

  12. Massive pulmonary embolism at the onset of acute promyelocytic leukemia

    Directory of Open Access Journals (Sweden)

    Federica Sorà

    2016-07-01

    Full Text Available Life-threatening bleeding is a major and early complication of acute promyelocytic leukemia (APL, but in the last years there is a growing evidence of thromboses in  APL. We report the first case of a young woman with dyspnea as the first symptom of APL due to massive pulmonary embolism (PE successfully treated with thrombolysis for PE and heparin. APL has been processed with a combination of all-trans retinoic acid (ATRA and arsenic trioxide (ATO obtaining complete remission.

  13. Induced massive star formation in the trifid nebula?

    Science.gov (United States)

    Cernicharo; Lefloch; Cox; Cesarsky; Esteban; Yusef-Zadeh; Mendez; Acosta-Pulido; Garcia Lopez RJ; Heras

    1998-10-16

    The Trifid nebula is a young (10(5) years) galactic HII region where several protostellar sources have been detected with the infrared space observatory. The sources are massive (17 to 60 solar masses) and are associated with molecular gas condensations at the edges or inside the nebula. They appear to be in an early evolutionary stage and may represent the most recent generation of stars in the Trifid. These sources range from dense, apparently still inactive cores to more evolved sources, undergoing violent mass ejection episodes, including a source that powers an optical jet. These observations suggest that the protostellar sources may have evolved by induced star formation in the Trifid nebula.

  14. Dynamic Star Formation in the Massive DR21 Filament

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, N.; /Saclay; Csengeri, T.; /Saclay; Bontemps, S.; /OASU, Floirac; Motte, F.; /Saclay; Simon, R.; /Cologne U.; Hennebelle, P.; /Paris Observ.; Federrath, C.; /ZAH, Heidelberg; Klessen, R.; /ZAH, Heidelberg /KIPAC, Menlo Park

    2010-08-25

    The formation of massive stars is a highly complex process in which it is unclear whether the star-forming gas is in global gravitational collapse or an equilibrium state supported by turbulence and/or magnetic fields. By studying one of the most massive and dense star-forming regions in the Galaxy at a distance of less than 3 kpc, i.e. the filament containing the well-known sources DR21 and DR21(OH), we attempt to obtain observational evidence to help us to discriminate between these two views. We use molecular line data from our {sup 13}CO 1 {yields} 0, CS 2 {yields} 1, and N{sub 2}H{sup +} 1 {yields} 0 survey of the Cygnus X region obtained with the FCRAO and CO, CS, HCO{sup +}, N{sub 2}H{sup +}, and H{sub 2}CO data obtained with the IRAM 30m telescope. We observe a complex velocity field and velocity dispersion in the DR21 filament in which regions of the highest column-density, i.e., dense cores, have a lower velocity dispersion than the surrounding gas and velocity gradients that are not (only) due to rotation. Infall signatures in optically thick line profiles of HCO{sup +} and {sup 12}CO are observed along and across the whole DR21 filament. By modelling the observed spectra, we obtain a typical infall speed of {approx}0.6 km s{sup -1} and mass accretion rates of the order of a few 10{sup -3} M{sub {circle_dot}} yr{sup -1} for the two main clumps constituting the filament. These massive clumps (4900 and 3300 M{sub {circle_dot}} at densities of around 10{sup 5} cm{sup -3} within 1 pc diameter) are both gravitationally contracting. The more massive of the clumps, DR21(OH), is connected to a sub-filament, apparently 'falling' onto the clump. This filament runs parallel to the magnetic field. Conclusions. All observed kinematic features in the DR21 filament (velocity field, velocity dispersion, and infall), its filamentary morphology, and the existence of (a) sub-filament(s) can be explained if the DR21 filament was formed by the convergence of flows

  15. The formation and evolution of massive black holes.

    Science.gov (United States)

    Volonteri, M

    2012-08-03

    The past 10 years have witnessed a change of perspective in the way astrophysicists think about massive black holes (MBHs), which are now considered to have a major role in the evolution of galaxies. This appreciation was driven by the realization that black holes of millions of solar masses and above reside in the center of most galaxies, including the Milky Way. MBHs also powered active galactic nuclei known to exist just a few hundred million years after the Big Bang. Here, I summarize the current ideas on the evolution of MBHs through cosmic history, from their formation about 13 billion years ago to their growth within their host galaxies.

  16. [Massive pneumocephalus and cerebrospinal fluid fistula after thoracotomy].

    Science.gov (United States)

    Olarra, J; Longarela, A

    2008-10-01

    We report the case of a 70-year-old man (ASA physical status 2) who developed massive pneumocephalus caused by a fistula between the subarachnoid and pleural spaces following a left pneumonectomy. After an uneventful immediate postoperative period, the patient was readmitted to the recovery care unit with dyspnea, intense headache, confusion, and diminished level of consciousness. Computed tomography confirmed a cerebrospinal fluid fistula secondary to the opening of the intradural space during tumor resection. Treatment was conservative, consisting of rest in a slightly Trendelenburg position, antibiotic prophylaxis to prevent meningitis, and a water seal on the thoracic drainage tube.

  17. MASSIVE OPEN ONLINE COURSES IN EDUCATION OF ROBOTICS

    Directory of Open Access Journals (Sweden)

    Gyula Mester

    2016-03-01

    Full Text Available Recently, the requirement for learning is constantly increasing. MOOC – massive open online courses represent educational revolution of the century. A MOOC is an online course accessible to unlimited number of participation and is an open access via the web. Mayor participants in the MOOCS are: Coursera, Udacity (Stanford, since 2012 and edX (Harvard, MIT, since 2012. In this paper two MOOCs are considered: Introduction for Robotics and Robotics Vision, both from the Queensland University of Technology, Brisbane, Australia.

  18. Complications following body contouring surgery after massive weight loss

    DEFF Research Database (Denmark)

    Hasanbegovic, Emir; Sørensen, Jens Ahm

    2014-01-01

    Bariatric surgery is a way to achieve lasting weight loss in the obese. Body contouring surgery seeks to alleviate some of the discomfort caused by the excessive loose skin following massive weight loss. Higher complication rates are described in this type of surgery when done post-bariatric....... The purpose of this article is to compare complication rates of body contouring surgery when performed on patients with weight loss due to bariatric surgery compared to patients who lost weight due to dietary changes and/or exercise....

  19. A possible connection between massive fermions and dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Terrance [Los Alamos National Laboratory; Stephenson, G J [UNM; Alsing, P M [UNM; Mckellar, B H J [UNIV OF MELBOURNE

    2009-01-01

    In a dense cloud of massive fermions interacting by exchange of a light scalar field, the effective mass of the fermion can become negligibly small. As the cloud expands, the effective mass and the total energy density eventually increase with decreasing density. In this regime, the pressure-density relation can approximate that required for dark energy. They apply this phenomenon to the expansion of the Universe with a very light scalar field and infer relations between the parameters available and cosmological observations. Majorana neutrinos at a mass that may have been recently determined, and fermions such as the Lightest Supersymmetric Particle (LSP) may both be consistent with current observations of dark energy.

  20. Massive star evolution: Luminous Blue Variables as unexpected Supernova progenitors

    OpenAIRE

    Groh, Jose H.; Meynet, Georges; Ekström, Sylvia

    2013-01-01

    Stars more massive than about 8 Msun end their lives as a Supernova (SN), an event of fundamental importance Universe-wide. Theoretically, these stars have been expected to be either at the red supergiant, blue supergiant, or Wolf-Rayet stage before the explosion. We performed coupled stellar evolution and atmospheric modeling of stars with initial masses between 20 Msun and 120 Msun. We found that the 20 Msun and 25 Msun rotating models, before exploding as SN, have spectra that do not resem...

  1. Fluid Resuscitation and Massive Transfusion Protocol in Pediatric Trauma

    Directory of Open Access Journals (Sweden)

    Marjanović Vesna

    2016-06-01

    Full Text Available Trauma is the leading cause of morbidity and mortality in children due to the occurrence of hemorrhagic shock. Hemorrhagic shock and its consequences, anemia and hypovolemia, decrease oxygen delivery, due to which appropriate transfusion and volume resuscitation are critical. Guidelines for massive transfusion, in the pediatric trauma, have not been defined yet. Current data indicate that early identification of coagulopathy and its treatment with RBSs, plasma and platelets in a 1:1:1 unit ratio, and limited use of crystalloids may improve survival in pediatric trauma patients.

  2. Closed-Form Decomposition of One-Loop Massive Amplitudes

    CERN Document Server

    Britto, Ruth; Mastrolia, Pierpaolo

    2008-01-01

    We present formulas for the coefficients of 2-, 3-, 4- and 5-point master integrals for one-loop massive amplitudes. The coefficients are derived from unitarity cuts in D dimensions. The input parameters can be read off from any unitarity-cut integrand, as assembled from tree-level expressions, after simple algebraic manipulations. The formulas presented here are suitable for analytical as well as numerical evaluation. Their validity is confirmed in two known cases of helicity amplitudes contributing to gg -> gg and gg -> gH, where the masses of the Higgs and the fermion circulating in the loop are kept as free parameters.

  3. Distributive estimation of frequency selective channels for massive MIMO systems

    KAUST Repository

    Zaib, Alam

    2015-12-28

    We consider frequency selective channel estimation in the uplink of massive MIMO-OFDM systems, where our major concern is complexity. A low complexity distributed LMMSE algorithm is proposed that attains near optimal channel impulse response (CIR) estimates from noisy observations at receive antenna array. In proposed method, every antenna estimates the CIRs of its neighborhood followed by recursive sharing of estimates with immediate neighbors. At each step, every antenna calculates the weighted average of shared estimates which converges to near optimal LMMSE solution. The simulation results validate the near optimal performance of proposed algorithm in terms of mean square error (MSE). © 2015 EURASIP.

  4. Massive hemorrhage management – a best evidence topic report

    Directory of Open Access Journals (Sweden)

    Vymazal T

    2015-07-01

    Full Text Available Tomas VymazalDepartment of Anesthesiology and Intensive Care Medicine, 2nd Faculty of Medicine Charles University, University Hospital Motol, Prague, Czech RepublicIntroduction: Massive hemorrhage remains a major cause of potentially preventable deaths. Better control of bleeding could improve survival rates by 10%–20%. Transfusion intervention concepts have been formulated in order to minimize acute traumatic coagulopathy. These interventions still have not been standardized and vary among medical centers.Materials and Methods: Based on a literature search using free term keywords and Medical Subject Heading (MeSH index, we analyzed published articles addressing massive hemorrhage, component therapy, fresh whole blood, and fibrinogen from the year 2000 onward, in journals with impact factor >1.000, in Medline, PubMed, and Google Scholar. The evidence was grouped into topics including laboratory testing and transfusion interventions/viscoelastic assays vs standard laboratory tests, the effect of component therapy on patient outcome, the effect of warm fresh whole blood on patient outcome, and the effects of fibrinogen in severe bleeding. The obtained information was compared, evaluated, confronted, and was focused on to present an adequate and individual-based massive hemorrhage management approach.Results: Viscoelastic whole-blood assays are superior to standard coagulation blood tests for the identification of coagulopathy and for guiding decisions on appropriate therapy in patients with severe bleeding. Replacement of plasma, red blood cells, platelets, and fibrinogen in a ratio of 1:1:1:1 has appeared to be the best substitution for lost whole blood. There is no evidence that cryoprecipitate improves the outcome of patients with severe hemorrhage. Current literature promotes the transfusion of warm fresh whole blood, which seems to be superior to the component therapy in certain clinical situations. Some authors recommend that fibrinogen

  5. Development of massively parallel quantum chemistry program SMASH

    Energy Technology Data Exchange (ETDEWEB)

    Ishimura, Kazuya [Department of Theoretical and Computational Molecular Science, Institute for Molecular Science 38 Nishigo-Naka, Myodaiji, Okazaki, Aichi 444-8585 (Japan)

    2015-12-31

    A massively parallel program for quantum chemistry calculations SMASH was released under the Apache License 2.0 in September 2014. The SMASH program is written in the Fortran90/95 language with MPI and OpenMP standards for parallelization. Frequently used routines, such as one- and two-electron integral calculations, are modularized to make program developments simple. The speed-up of the B3LYP energy calculation for (C{sub 150}H{sub 30}){sub 2} with the cc-pVDZ basis set (4500 basis functions) was 50,499 on 98,304 cores of the K computer.

  6. Strong interactions and exact solutions in nonlinear massive gravity

    Science.gov (United States)

    Koyama, Kazuya; Niz, Gustavo; Tasinato, Gianmassimo

    2011-09-01

    We investigate strong coupling effects in a covariant massive gravity model, which is a candidate for a ghost-free nonlinear completion of Fierz-Pauli. We analyze the conditions to recover general relativity via the Vainshtein mechanism in the weak field limit, and find three main cases depending on the choice of parameters. In the first case, the potential is such that all nonlinearities disappear and the vDVZ discontinuity cannot be avoided. In the second case, the Vainshtein mechanism allows to recover general relativity within a macroscopic radius from a source. In the last case, the strong coupling of the scalar graviton completely shields the massless graviton, and weakens gravity when approaching the source. In the second part of the paper, we explore new exact vacuum solutions, that asymptote to de Sitter or anti de Sitter space depending on the choice of parameters. The curvature of the space is proportional to the mass of the graviton, thus providing a cosmological background which may explain the present-day acceleration in terms of the graviton mass. Moreover, by expressing the potential for nonlinear massive gravity in a convenient form, we also suggest possible connections with a higher-dimensional framework.

  7. Coexistent physics of massive black holes in the phase transitions

    CERN Document Server

    Zhang, Ming

    2016-01-01

    The coexistent physics of de Rham-Gabada-dze-Tolley (dRGT) massive black holes and holographic massive black holes is investigated in the extended phase space where the cosmological constant is viewed as pressure. Van der Waals like phase transitions are found for both of them. Coexistent curves of reduced pressure and reduced temperature are found to be different from that of RN-AdS black holes. Coexistent curves of reduced Gibbs free energy and reduced pressure show that Gibbs free energy in the canonical ensemble decreases monotonically with the increasing pressure. The concept number density is introduced to study the coexistent physics. It is uncovered that with the increasing pressure, the number densities of small black holes (SBHs) and large black holes (LBHs) change monotonically in the contrary directions till finally reaching the same value at the critical points of the phase transitions. In other words, with the increasing pressure the number density differences between SBHs and LBHs decrease mono...

  8. Abstracting massive data for lightweight intrusion detection in computer networks

    KAUST Repository

    Wang, Wei

    2016-10-15

    Anomaly intrusion detection in big data environments calls for lightweight models that are able to achieve real-time performance during detection. Abstracting audit data provides a solution to improve the efficiency of data processing in intrusion detection. Data abstraction refers to abstract or extract the most relevant information from the massive dataset. In this work, we propose three strategies of data abstraction, namely, exemplar extraction, attribute selection and attribute abstraction. We first propose an effective method called exemplar extraction to extract representative subsets from the original massive data prior to building the detection models. Two clustering algorithms, Affinity Propagation (AP) and traditional . k-means, are employed to find the exemplars from the audit data. . k-Nearest Neighbor (k-NN), Principal Component Analysis (PCA) and one-class Support Vector Machine (SVM) are used for the detection. We then employ another two strategies, attribute selection and attribute extraction, to abstract audit data for anomaly intrusion detection. Two http streams collected from a real computing environment as well as the KDD\\'99 benchmark data set are used to validate these three strategies of data abstraction. The comprehensive experimental results show that while all the three strategies improve the detection efficiency, the AP-based exemplar extraction achieves the best performance of data abstraction.

  9. The Massive Star Forming Region Cygnus OB2

    Science.gov (United States)

    Wright, Nicholas James; Drake, J. J.; Drew, J. E.

    2009-12-01

    We present a multi-wavelength study of the massive star forming Cygnus OB2. Cygnus OB2 is the northern hemisphere's most massive star forming region and hosts a tremendously rich and diverse stellar population, with thousands of OB stars. The strong and highly variable extinction in the direction of the association have hindered previous studies of the region, but recent deep photometric surveys in the optical and near-infrared are opening the region up for study. The appreciation of the pivotal status of Cyg OB2 has led to a number of recent ambitious surveys of the cluster and its setting within the Cygnus-X region at X-ray, infrared and radio wavelengths. Chandra X-ray observations of two fields in the center of the association reveal 1720 X-ray sources, which we have combined with optical and near-IR photometry from the IPHAS and UKIDSS surveys. Near-IR photometry reveals a stellar population with a spread of ages greater than previously thought, overturning the picture of coeval star formation in the region. The distribution of young sources in the region shows evidence for clustering and significant mass segregation, which we judge to be primordial given the cluster's age.

  10. Stellar and wind parameters of massive stars from spectral analysis

    Science.gov (United States)

    Araya, Ignacio; Curé, Michel

    2017-11-01

    The only way to deduce information from stars is to decode the radiation it emits in an appropriate way. Spectroscopy can solve this and derive many properties of stars. In this work we seek to derive simultaneously the stellar and wind characteristics of a wide range of massive stars. Our stellar properties encompass the effective temperature, the surface gravity, the stellar radius, the micro-turbulence velocity, the rotational velocity and the Si abundance. For wind properties we consider the mass-loss rate, the terminal velocity and the line-force parameters α, k and δ (from the line-driven wind theory). To model the data we use the radiative transport code Fastwind considering the newest hydrodynamical solutions derived with Hydwind code, which needs stellar and line-force parameters to obtain a wind solution. A grid of spectral models of massive stars is created and together with the observed spectra their physical properties are determined through spectral line fittings. These fittings provide an estimation about the line-force parameters, whose theoretical calculations are extremely complex. Furthermore, we expect to confirm that the hydrodynamical solutions obtained with a value of δ slightly larger than ~ 0.25, called δ-slow solutions, describe quite reliable the radiation line-driven winds of A and late B supergiant stars and at the same time explain disagreements between observational data and theoretical models for the Wind-Momentum Luminosity Relationship (WLR).

  11. Spatial Correlation Characterization of a Full Dimension Massive MIMO System

    KAUST Repository

    Nadeem, Qurrat-Ul-Ain

    2017-02-07

    Elevation beamforming and Full Dimension MIMO (FD-MIMO) are currently active areas of research and standardization in 3GPP LTE-Advanced. FD-MIMO utilizes an active antenna array system (AAS), that provides the ability of adaptive electronic beam control over the elevation dimension, resulting in a better system performance as compared to the conventional 2D MIMO systems. FD-MIMO is more advantageous when amalgamated with massive MIMO systems, in that it exploits the additional degrees of freedom offered by a large number of antennas in the elevation. To facilitate the evaluation of these systems, a large effort in 3D channel modeling is needed. This paper aims at providing a summary of the recent 3GPP activity around 3D channel modeling. The 3GPP proposed approach to model antenna radiation pattern is compared with the ITU approach. A closed-form expression is then worked out for the spatial correlation function (SCF) for channels constituted by individual antenna elements in the array by exploiting results on spherical harmonics and Legendre polynomials. The proposed expression can be used to obtain correlation coefficients for any arbitrary 3D propagation environment. Simulation results corroborate and study the derived spatial correlation expression. The results are directly applicable to the analysis of future 5G 3D massive MIMO systems.

  12. Massive and recurrent diverticular hemorrhage, risk factors and treatment.

    Science.gov (United States)

    Gilshtein, Hayim; Kluger, Yoram; Khoury, Areen; Issa, Nidal; Khoury, Wisam

    2016-09-01

    Diverticular hemorrhage may be massive or recurrent, requiring surgical management. The aim of our study is to define risk factors that predict rebleeding or need for urgent operation in patients with diverticular hemorrhage. Retrospective study was conducted on patients who were admitted for diverticular hemorrhage. Data pertaining to patient and bleeding characteristics, method of diagnosis, blood transfusion and type of operation were collected. Multivariate analysis model compared patients who experienced single bleeding episode with those with recurrent episodes, and patients who underwent surgery with those who did not. One hundred and four patients met the inclusion criteria. Thirty four patients experienced more than one bleeding episode. Ten patients needed surgery for recurrent bleeding. Five patients presented with hemodynamic instability, none of them required surgical treatment. Neither patients' comorbidity nor anticoagulant and antiaggregant treatments were associated with increased risk for recurrent hemorrhage. Diabetes mellitus was correlated with decreased risk for recurrent hemorrhage, OR = 0.21, (CI 95% (0.06-0.73)); p = 0.014. Independent risk factor for massive recurrent diverticular hemorrhage requiring surgery was right sided diverticulosis, OR = 4.6(CI 95% (2.1-19)); p = 0.006. Right colon diverticulosis rather than patient characteristics and medical treatment should prompt for aggressive management with lower threshold for surgical intervention. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Stellar haloes in massive early-type galaxies

    Science.gov (United States)

    Buitrago, F.

    2017-03-01

    The Hubble Ultra Deep Field (HUDF) opens up an unique window to witness galaxy assembly at all cosmic distances. Thanks to its extraordinary depth, it is a privileged tool to beat the cosmological dimming, which affects any extragalactic observations and has a very strong dependence with redshift (1 +z)^4. In particular, massive (M_{stellar}>5 × 10^{10} M_⊙) Early Type Galaxies (ETGs) are the most interesting candidates for these studies, as they must grow in an inside-out fashion developing an extended stellar envelope/halo that accounts for their remarkable size evolution (˜5 times larger in the nearby Universe than at z=2-3). To this end we have analysed the 6 most massive ETGs at z data reduction and the exhaustive treatment of the Point Spread Function (PSF), we are able to trace the galaxy surface brightness profiles up to the same levels as in the local Universe but this time at = 0.65 (31 mag arcsec^{-2} in all 8 HST bands, ˜ 29 mag arcsec^{-2} restframe or beyond 25 effective radii). This fact enables us to investigate the galactic outskirts or stellar haloes at a previously unexplored era, characterising their light and mass profiles, colors and for the first time the amount of mass in ongoing mergers.

  14. Enhanced Deposition Uniformity via an Auxiliary Electrode in Massive Electrospinning.

    Science.gov (United States)

    Wu, Dezhi; Xiao, Zhiming; Deng, Lei; Sun, Yu; Tan, Qiulin; Dong, Linxi; Huang, Shaohua; Zhu, Rui; Liu, Yifang; Zheng, Wanxi; Zhao, Yang; Wang, Lingyun; Sun, Daoheng

    2016-07-22

    Uniform deposition of nanofibers in the massive electrospinning process is critical in the industrial applications of nanofibers. Tip-Induced Electrospinning (TIE) is a cost-effective large-scale nanofiber-manufacturing method, but it has poor deposition uniformity. An auxiliary conductive electrode connected to the emitting electrode was introduced to improve the deposition uniformity of the nanofibers. The effects of the auxiliary electrode shape, the tilted angles and the position of the boat-like electrode on the electric field distribution, the diameter of the nanofibers, the jet control and the deposition uniformity were explored by using finite element analysis of the electric field and experiments. Experiments showed that the boat-like electrode at 20 mm above the reservoir bottom with a 5° tilted angle helped to decrease the relative deposition error of nanofibers in the greatest extent to about 5.66%, indicating such an auxiliary electrode is a good candidate method to greatly improve the deposition uniformity of nanofibers in massive electrospinning.

  15. Survival of acute hypernatremia due to massive soy sauce ingestion.

    Science.gov (United States)

    Carlberg, David J; Borek, Heather A; Syverud, Scott A; Holstege, Christopher P

    2013-08-01

    Intentional massive sodium chloride ingestions are rare occurrences and are often fatal. There are a variety of treatment recommendations for hypernatremia, ranging from dialysis to varying rates of correction. We report a case of acute severe hypernatremia corrected with rapid free-water infusions that, to our knowledge, has not been previously reported. A 19-year-old man presented to the Emergency Department in a comatose state with seizure-like activity 2 hours after ingesting a quart of soy sauce. He was administered 6 L of free water over 30 min and survived neurologically intact without clinical sequelae. Corrected for hyperglycemia, the patient's peak serum sodium was 196 mmol/L, which, to our knowledge, is the highest documented level in an adult patient to survive an acute sodium ingestion without neurologic deficits. Emergency physicians should consider rapidly lowering serum sodium with hypotonic intravenous fluids as a potential management strategy for acute severe hypernatremia secondary to massive salt ingestion. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. A massive, dead disk galaxy in the early Universe

    Science.gov (United States)

    Toft, Sune; Zabl, Johannes; Richard, Johan; Gallazzi, Anna; Zibetti, Stefano; Prescott, Moire; Grillo, Claudio; Man, Allison W. S.; Lee, Nicholas Y.; Gómez-Guijarro, Carlos; Stockmann, Mikkel; Magdis, Georgios; Steinhardt, Charles L.

    2017-06-01

    At redshift z = 2, when the Universe was just three billion years old, half of the most massive galaxies were extremely compact and had already exhausted their fuel for star formation. It is believed that they were formed in intense nuclear starbursts and that they ultimately grew into the most massive local elliptical galaxies seen today, through mergers with minor companions, but validating this picture requires higher-resolution observations of their centres than is currently possible. Magnification from gravitational lensing offers an opportunity to resolve the inner regions of galaxies. Here we report an analysis of the stellar populations and kinematics of a lensed z = 2.1478 compact galaxy, which—surprisingly—turns out to be a fast-spinning, rotationally supported disk galaxy. Its stars must have formed in a disk, rather than in a merger-driven nuclear starburst. The galaxy was probably fed by streams of cold gas, which were able to penetrate the hot halo gas until they were cut off by shock heating from the dark matter halo. This result confirms previous indirect indications that the first galaxies to cease star formation must have gone through major changes not just in their structure, but also in their kinematics, to evolve into present-day elliptical galaxies.

  17. Role of Rotation in Massive Stars in the SMC

    Science.gov (United States)

    Heap, Sara R.; Lanz, Thierry

    2002-01-01

    We report on an analysis of FUSE+STIS+optical spectra of 17 O-type stars in the SMC. We found an enormous range in N abundances. Three stars in the sample have the same (low) CN abundances as the nebular material out of which they formed, namely C=0.08 C(sub circle dot) and N=0.03 N(sub circle dot). However, more than half shows NO, an enrichment factor of 30X! Such a high level of N enrichment cannot be reproduced by current evolutionary models accounting for rotationally induced mixing. It suggests that the sum of CNO nuclei may not be conserved, i.e. massive stars might be producing primary nitrogen. It raises questions concerning the sources of nitrogen in the early universe, presently thought to be almost exclusively intermediate-mass stars. It also raises basic questions about the evolution of massive stars in low-metallicity environments, including the precursors to supernovae.

  18. Massive Alveolar Hemorrhage During Wegener Granulomatosis: a Case Report

    Directory of Open Access Journals (Sweden)

    Gökhan Perincek

    2011-11-01

    Full Text Available This is a presentation of Wegener Granulomatosis (WG disease. Even though the lungs are rarely affected. massive alveolar hemorrhage is seen which leads to mortality. The patient was a 28 year old man. His illness was diagnosed as WG and glomerulonephritis a year previously and he was treated by administration of methylprednisolone orally. He had been treated irregularly. He applied to the emergency service with hemoptysis and asthma complaints two days earlier. After the results of his examination Hb: 3.6 gr/dl, Htc:10.3%, Üre:131 mg /dl, kreatini: 7.7 mg/dl, pH: 7.41, pO2: 55 mmHg, pCO2:33 mmHg, and being diagnosed as alveolar consolidation on lung X-ray, he was taken to the intensive care unit with a diagnosis of a massive alveolar hemorrhagei. He was intubated and attached to mechanical ventilation. He was treated with parenteral 1 mg/kg/day methylprednisolone and, siklofosfamid 2 mg/kg/day. He was extubated on the 21st day. He was taken to the chest service department on 24th day. He is still being treated.

  19. Genetic susceptibility to progressive massive fibrosis in coal miners

    Energy Technology Data Exchange (ETDEWEB)

    Yucesoy, B.; Johnson, V.J.; Kissling, G.E.; Fluharty, K.; Kashon, M.L.; Slaven, J.; Germolec, D.; Vallyathan, V.; Luster, M.I. [NIOSH, Morgantown, WV (United States)

    2008-06-15

    Progressive massive fibrosis (PMF) is a chronic interstitial lung disease with a complex aetiology that can occur after cumulative dust exposure. A case-control study was conducted to test the hypothesis that single nucleotide polymorphisms (SNPs) within genes involved in inflammatory and fibrotic processes modulate the risk of PMF development. The study population consisted of 648 underground coal miners participating in the National Coal Workers Autopsy Study, of which 304 were diagnosed with PMF SNPs that influence the regulation of interleukin (IL)-1, IL-6, tumour necrosis factor-alpha, transforming growth factor-beta 1, vascular endothelial growth factor (VEGF), epidermal growth factor intercellular cell adhesion molecule (ICAM)-1 and matrix metalloproteinase-2 genes were determined using a 5'-nuclease real-time PCR assay. There were no significant differences in the distribution of any individual SNP or haplotype between the PMF and control groups. However, the polygenotype of VEGF +405/ICAM-1 +241/IL-6 -174 (C-A-G) conferred an increased risk for PMF (odds ratio 3.4, 95% confidence interval 1.3-8.8). The present study suggests that the examined genetic variations that help regulate inflammatory and fibrotic processes are unlikely to strongly influence susceptibility to this interstitial lung disease, although the role of vascular endothelial growth factor, intercellular cell adhesion molecule-1 and interleukin-6 polymorphisms in the development of progressive massive fibrosis may require further investigation.

  20. Formation of young massive clusters from turbulent molecular clouds

    Science.gov (United States)

    Fujii, Michiko S.; Portegies Zwart, Simon

    2017-03-01

    We simulate the formation and evolution of young star clusters from turbulent molecular clouds using smoothed-particle hydrodynamics and direct N-body methods. We find that the shape of the cluster mass function that originates from an individual molecular cloud is consistent with a Schechter function with power-law slopes of β = -1.73. The superposition of mass functions turn out to have a power-law slope of < -2. The mass of the most massive cluster formed from a single molecular cloud with mass M g scales with 6.1 M 0.51 g. The molecular clouds that tend to form massive clusters are much denser than those typical found in the Milky Way. The velocity dispersion of such molecular clouds reaches 20km s-1 and it is consistent with the relative velocity of the molecular clouds observed near NGC 3603 and Westerlund 2, for which a triggered star formation by cloud-cloud collisions is suggested.