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Sample records for active giant pockmark

  1. ROV study of a giant pockmark on the Gabon continental margin

    NASA Astrophysics Data System (ADS)

    Ondréas, H.; Olu, K.; Fouquet, Y.; Charlou, J. L.; Gay, A.; Dennielou, B.; Donval, J. P.; Fifis, A.; Nadalig, T.; Cochonat, P.; Cauquil, E.; Bourillet, J. F.; Moigne, M. Le; Sibuet, M.

    2005-11-01

    A giant, 800-m wide pockmark, called Regab, was discovered along the Equatorial African margin at 3160-m water depth and was explored by remote operated vehicle (ROV) as part of the Zaiango (1998-2000) and Biozaire (2001-2003) projects carried out conjointly by TOTAL and a number of French research institutes. A microbathymetric map obtained using the ROV sensors shows that the pockmark actually consists of a cluster of smaller pockmarks aligned N70 along a 15-m deep depression. Methane was recorded all over the pockmark, the highest values along the axis of the depression where massive carbonate crusts and dense seep communities were also found. Several faunal species belong to the Vesicomyidae and Mytilidae bivalve families, as well as to Siboglinidae (Vestimentifera) tubeworms. Preliminary analyses confirm their association with symbiotic bacteria, thus documenting their dependence on fluid seeps. The pockmark appears to be related to an infilled channel, visible on the seismic data 300 m below the seafloor, which may act as a reservoir for biogenic fluids supplied to the trap from the surrounding sediments.

  2. A climatic trigger for the giant Troll pockmark field in the northern North Sea

    NASA Astrophysics Data System (ADS)

    Mazzini, Adriano; Svensen, Henrik H.; Forsberg, Carl Fredrik; Linge, Henriette; Lauritzen, Stein-Erik; Haflidason, Haflidi; Hammer, Øyvind; Planke, Sverre; Tjelta, Tor Inge

    2017-04-01

    Pockmarks are seafloor craters usually formed during methane release on continental margins. However, the mechanisms behind their formation and dynamics remain elusive. Here we report detailed investigations on one of the World's largest pockmark fields located in the Troll region in the northern North Sea. Seafloor investigations show that >7000 pockmarks are present in a ∼600 km2 area. A similar density of pockmarks is likely present over a 15,000 km2 region outside our study area. Based on extensive monitoring, coring, geophysical and geochemical analyses, no indications of active gas seepage were found. Still, geochemical data from carbonate blocks collected from these pockmarks indicate a methanogenic origin linked to gas hydrate dissociation and past fluid venting at the seafloor. We have dated the carbonates using the U-Th method in order to constrain the pockmark formation. The carbonates gave an isochron age of 9.59 ± 1.38 ka, i.e. belonging to the initial Holocene. Moreover, radiocarbon dating of microfossils in the sediments inside the pockmarks is consistent with the ages derived from the carbonates. Based on pressure and temperature modelling, we show that the last deglaciation could have triggered dissociation of gas hydrates present in the region of the northern part of the Norwegian Channel, causing degassing of 0.26 MtCH4/km2 at the seafloor. Our results stress the importance of external climatic forcing of the dynamics of the seafloor, and the role of the rapid warming following the Younger Dryas in pacing the marine gas hydrate reservoir.

  3. Geochemistry of pore-fluids related to the distribution of the biological communities on the giant Regab pockmark, off Gabon

    NASA Astrophysics Data System (ADS)

    de Prunelé, A.; Caprais, J.; Ruffine, L.; Cassarino, L.; Guyader, V.; Bollinger, C.; Ondréas, H.; Donval, J.; Olu, K.; Geli, L. B.; Cunningham, K. L.; Cauquil, E.

    2013-12-01

    The Regab pockmark is a giant structure located at 3200 m water depth offshore Gabon and ~ 10 km north to the deep Congo channel (Zaïre canyon) (Gay et al. 2006; Ondréas et al. 2005). It has been visited for the first time in 2000 during the Zairov cruise. Since that time, several scientific cruises have allowed further investigations of this pockmark. The last cruise, WACS, for West Africa Cold Seeps, in January- February 2010, was undertaken on board the R/V ';Pourquoi Pas?' with the aim of identifying changes which can occur over time on this pockmark. Besides intensive ROV dives, three calypso cores and several push cores have been collected to better understand the relationships between the distribution of the living communities and the pore-fluids chemistry. In two calypso cores one collected within the pockmark and one outside, and both in areas without visible biological communities, pore-fluids profiles of dissolved elements (Alk, SO42-, Mn2+, Fe2+) show that degradation of organic matter is occurring and likely plays an important role in the sulfate reduction (Froelich et al. 1979). Methane was not detected. The Analysis of the pore-fluids by Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) has shown the presence of alcohols, acid and phenol. These molecules are likely related to the degradation of organic matter and/or the production of the biological communities. Further investigations are ongoing to provide us with a clearer picture regarding the source of these molecules. The third calypso core collected in the northeast part of the pockmark containing gas hydrates. Sulfate profiles from the push cores show significant difference from one community to another. The analyses of both major and minor dissolved elements, along with molecular and isotopic methane concentration measurements are in progress for the push cores. The latter was done using a new analyzer G2201-i from Picarro for which new methods applied to pore-fluids has

  4. Pockmarks: self-scouring seep features?

    USGS Publications Warehouse

    Brothers, Laura L.; Kelley, Joseph T.; Belknap, Daniel F.; Barnhardt, Walter A.; Koons, Peter O.

    2011-01-01

    Pockmarks, or seafloor craters, occur worldwide in a variety of geologic settings and are often associated with fluid discharge. The mechanisms responsible for pockmark preservation, and pockmarks? relation to active methane venting are not well constrained. Simple numerical simulations run in 2-and 3-dimensions, and corroborated by flume tank experiments, indicate turbulence may play a role in pockmark maintenance, and, potentially, in pockmark excavation. Morphological analysis of the pockmarks indicates an abundance of flat-bottomed and/or elongated pockmarks. Pockmarks transition into furrows as the bay narrows and tidal flow is enhanced, providing unmistakable evidence of post-formation evolution. We hypothesize that some pockmarks formed from seafloor perturbations (e.g., gas or methane discharge), are1 maintained and gradually modified by vortical flow. This hypothesis provides a mechanism for pockmark preservation and enlargement without active fluid venting, which has implications for the interpretation of seafloor seep features in gas hydrates areas.

  5. Geophysical exploration of an active pockmark field in the Bay of Concarneau, southern Brittany, and implications for resident suspension feeders

    NASA Astrophysics Data System (ADS)

    Baltzer, Agnès; Ehrhold, Axel; Rigolet, Carinne; Souron, Aurélie; Cordier, Céline; Clouet, Hélène; Dubois, Stanislas F.

    2014-06-01

    About a decade ago, a large field of pockmarks (individual features up to 30 m in diameter and <2 m deep) was discovered in water depths of 15-40 m in the Bay of Concarneau in southern Brittany along the French Atlantic coast, covering an overall area of 36 km2 and characterised by unusually high pockmark densities in places reaching 2,500 per square kilometre. As revealed by geophysical swath and subbottom profile data ground-truthed by sediment cores collected during two campaigns in 2005 and 2009, the confines of the pockmark field show a spectacular spatial association with those of a vast expanse of tube mats formed by a benthic community of the suspension-feeding amphipod Haploops nirae. The present study complements those findings with subbottom chirp profiles, seabed sonar imagery and ultrasonic backscatter data from the water column acquired in April 2011. Results show that pockmark distribution is influenced by the thickness of Holocene deposits covering an Oligocene palaeo-valley system. Two groups of pockmarks were identified: (1) a group of large (>10 m diameter), more widely scattered pockmarks deeply rooted (up to 8 ms two-way travel time, TWTT) in the Holocene palaeo-valley infills, and (2) a group of smaller, more densely spaced pockmarks shallowly rooted (up to 2 ms TWTT) in interfluve deposits. Pockmark pore water analyses revealed high methane concentrations peaking at ca. 400 μl/l at 22 and 30 cm core depth in silty sediments immediately above Haploops-bearing layers. Water column data indicate acoustic plumes above pockmarks, implying ongoing pockmark activity. Pockmark gas and/or fluid expulsion resulting in increased turbidity (resuspension of, amongst others, freshly settled phytoplankton) could at least partly account for the strong spatial association with the phytoplankton-feeding H. nirae in the Bay of Concarneau, exacerbating impacts of anthropogenically induced eutrophication and growing offshore trawling activities. Tidally driven

  6. Pockmarks off Big Sur, California

    USGS Publications Warehouse

    Paull, C.; Ussler, W.; Maher, N.; Greene, H. Gary; Rehder, G.; Lorenson, T.; Lee, H.

    2002-01-01

    A pockmark field was discovered during EM-300 multi-beam bathymetric surveys on the lower continental slope off the Big Sur coast of California. The field contains ??? 1500 pockmarks which are between 130 and 260 m in diameter, and typically are 8-12 m deep located within a 560 km2 area. To investigate the origin of these features, piston cores were collected from both the interior and the flanks of the pockmarks, and remotely operated vehicle observation (ROV) video and sampling transects were conducted which passed through 19 of the pockmarks. The water column within and above the pockmarks was sampled for methane concentration. Piston cores and ROV collected push cores show that the pockmark field is composed of monotonous fine silts and clays and the cores within the pockmarks are indistinguishable from those outside the pockmarks. No evidence for either sediment winnowing or diagenetic alteration suggestive of fluid venting was obtained. 14C measurements of the organic carbon in the sediments indicate continuous sedimentation throughout the time resolution of the radiocarbon technique ( ??? 45000 yr BP), with a sedimentation rate of ??? 10 cm per 1000 yr both within and between the pockmarks. Concentrations of methane, dissolved inorganic carbon, sulfate, chloride, and ammonium in pore water extracted from within the cores are generally similar in composition to seawater and show little change with depth, suggesting low biogeochemical activity. These pore water chemical gradients indicate that neither significant accumulations of gas are likely to exist in the shallow subsurface ( ??? 100 m) nor is active fluid advection occurring within the sampled sediments. Taken together the data indicate that these pockmarks are more than 45000 yr old, are presently inactive, and contain no indications of earlier fluid or gas venting events. ?? 2002 Elsevier Science B.V. All rights reserved.

  7. Benthic foraminifera from the deep-water Niger delta (Gulf of Guinea): Assessing present-day and past activity of hydrate pockmarks

    NASA Astrophysics Data System (ADS)

    Fontanier, C.; Koho, K. A.; Goñi-Urriza, M. S.; Deflandre, B.; Galaup, S.; Ivanovsky, A.; Gayet, N.; Dennielou, B.; Grémare, A.; Bichon, S.; Gassie, C.; Anschutz, P.; Duran, R.; Reichart, G. J.

    2014-12-01

    We present ecological and isotopic (δ18O and δ13C) data on benthic foraminifera sampled from 4 deep-sea stations in a pockmark field from the deep-water Niger delta (Gulf of Guinea, Equatorial Atlantic Ocean). In addition, a series of sedimentological and (bio)geochemical data are shown to back up foraminiferal observations. All stations are located within 1.2 km of each other, so prevailing oceanographic conditions can be assumed to be similar at each site. Two of the sites (GMMC-01 and GMMC-02) are located in a pockmark (named "pockmark A") where current methane seepages were recorded by ROV observations. A third station (GMMC-03) is located in the topographic depression interpreted as a collapsed pockmark (named "pockmark B"). The fourth site (GMMC-04) is a reference station, without evidence of past or present seepages. Our observations show that degraded organic matter with low bio-availability is present at all stations with a preferential burial of organic compounds in topographic depressions (GMMC-03 station). Authigenic aragonite is abundant in surface sediments at stations GMMC-01 and -02. Its precipitation is likely related to high rates of methane oxidation during past seep events in episodically active pockmark A. In contrast, the absence of anaerobic methanotrophic Archaea (ANME) during the sampling period (November 2011) suggests that only moderate sulphide and methane oxidation take place close to the sediment-water interface. Compared to the reference site GMMC-04, living foraminifera at the collapsed and episodically active pockmarks show minor changes in terms of diversity, standing stocks and faunal composition. However, the δ13C signal of living and dead (but well-preserved) foraminiferal species (Ceratobulimina contraria, Melonis barleeanus, Uvigerina peregrina) is depleted in the episodically active pockmark A compared to the other stations. Overgrowth of authigenic carbonate on altered foraminifera generates an important shift to lower

  8. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Jiangxin; Song, Haibin; Guan, Yongxian; Yang, Shengxiong; Pinheiro, Luis M.; Bai, Yang; Liu, Boran; Geng, Minghui

    2015-12-01

    Based on new high-resolution multi-beam bathymetry and multichannel seismic reflection data, two new groups of numerous pockmarks and mud volcanoes were discovered in the northern Zhongjiannan Basin at water depths between 600 and 1400 m. Individual pockmarks are circular, elliptical, crescent-shaped or elongated, with diameters ranging from several hundreds to thousands of meters and tens or hundreds of meters in depth, and they often form groups or strings. Crescent pockmarks, approximately 500-1500 m wide in cross-section and 50-150 m deep, occur widely in the southern study area, both as individual features and in groups or curvilinear chains, and they are more widespread and unique in this area than anywhere else in the world. Conical mud volcanoes, mostly with kilometer-wide diameters and ca. 100 m high, mainly develop in the northern study area as individual features or in groups. Seismic data show that the observed pockmarks are associated with different kinds of fluid escape structures and conduits, such as gas chimneys, diapirs, zones of acoustic blanking, acoustic turbidity and enhanced reflections, inclined faults, small fractures and polygonal faults. The mapped mud volcanoes appear to be fed from deep diapirs along two main conduit types: the conventional conduits with downward tapering cones and another other conduit type with a narrow conduit in the lower half and emanative leakage passages in the upper half. Various types of pockmarks are found and a comprehensive pockmark classification scheme is proposed, according to: (a) their shape in plan view, which includes circular, elliptical, crescent, comet-shape, elongated and irregular; (b) their magnitude, which includes small, normal, giant and mega-pockmarks; and (c) their composite pattern, which includes composite pockmarks, pockmark strings and pockmark groups. For the genesis of the crescent pockmark (strings), a 5-stage speculative formation model is proposed, implying possible controlling

  9. The significance of pockmarks to understanding fluid flow processes and geohazards

    USGS Publications Warehouse

    Hovland, M.; Gardner, J.V.; Judd, A.G.

    2002-01-01

    Underwater gas and liquid escape from the seafloor has long been treated as a mere curiosity. It was only after the advent of the side-scan sonar and the subsequent discovery of pockmarks that the scale of fluid escape and the moonlike terrain on parts of the ocean floor became generally known. Today, pockmarks ranging in size from the 'unit pockmark' (1-10 m wide, <0.6 m deep) to the normal pockmark (10-700 m wide, up to 45 m deep) are known to occur in most seas, oceans, lakes and in many diverse geological settings. In addition to indicating areas of the seabed that are 'hydraulically active', pockmarks are known to occur on continental slopes with gas hydrates and in association with slides and slumps. However, possibly their potentially greatest significance is as an indicator of deep fluid pressure build-up prior to earthquakes. Whereas only a few locations containing active (bubbling) pockmarks are known, those that become active a few days prior to major earthquakes may be important precursors that have been overlooked. Pockmark fields and individual pockmarks need to be instrumented with temperature and pressure sensors, and monitoring should continue over years. The scale of such research calls for a multinational project in several pockmark fields in various geological settings.

  10. Linking geology and microbiology: inactive pockmarks affect sediment microbial community structure.

    PubMed

    Haverkamp, Thomas H A; Hammer, Øyvind; Jakobsen, Kjetill S

    2014-01-01

    Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslofjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmarks and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial communities at the sediment surface are affected by the water column, while the deeper (40 cm) sediment communities are affected by local conditions within the sediment.

  11. Diversity and Distribution of Prokaryotes within a Shallow-Water Pockmark Field

    PubMed Central

    Giovannelli, Donato; d'Errico, Giuseppe; Fiorentino, Federica; Fattorini, Daniele; Regoli, Francesco; Angeletti, Lorenzo; Bakran-Petricioli, Tatjana; Vetriani, Costantino; Yücel, Mustafa; Taviani, Marco; Manini, Elena

    2016-01-01

    Pockmarks are crater-like depression on the seafloor associated with hydrocarbon ascent through muddy sediments in continental shelves around the world. In this study, we examine the diversity and distribution of benthic microbial communities at shallow-water pockmarks adjacent to the Middle Adriatic Ridge. We integrate microbial diversity data with characterization of local hydrocarbons concentrations and sediment geochemistry. Our results suggest these pockmarks are enriched in sedimentary hydrocarbons, and host a microbial community dominated by Bacteria, even in deeper sediment layers. Pockmark sediments showed higher prokaryotic abundance and biomass than surrounding sediments, potentially due to the increased availability of organic matter and higher concentrations of hydrocarbons linked to pockmark activity. Prokaryotic diversity analyses showed that the microbial communities of these shallow-water pockmarks are unique, and comprised phylotypes associated with the cycling of sulfur and nitrate compounds, as well as numerous know hydrocarbon degraders. Altogether, this study suggests that shallow-water pockmark habitats enhance the diversity of the benthic prokaryotic biosphere by providing specialized environmental niches. PMID:27379070

  12. Pockmarks in Passamaquoddy Bay, New Brunswick, Canada

    USGS Publications Warehouse

    Brothers, Laura; Legere, Christine; Hughes Clark, J.E.; Kelley, J.T.; Barnhardt, Walter; Andrews, Brian; Belknap, D.F.

    2016-01-01

    Pockmarks are seafloor depressions associated with fluid escape (Judd & Hovland 2007). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (Ussler et al. 2003; Rogers et al. 2006; Wildish et al. 2008). In North America, shallow-water pockmark fields are not reported south of Long Island Sound, despite the abundance of gassy, muddy estuaries. The absence of pockmarks south of the limit of North American glaciation suggests that local and regional heterogeneities, possibly related to glacial or sea-level history or bedrock geology, influence pockmark field distribution. In shallow-water embayments, such as Passamaquoddy Bay, New Brunswick, pockmarks can be large (>200 m diameter) and number in the thousands.

  13. Constraints on the Dynamics of Seabed Pockmarks: an Integrated Sedimentological, Biostratigraphic, Geophysical, Oceanographic and Experimental Approach

    NASA Astrophysics Data System (ADS)

    Pau, M.; Hammer, Ø.; Chand, S.; Gisler, G. R.

    2015-12-01

    Pockmarks are crater-like seabed depressions commonly resulting from focused fluid escape from soft, fine-grained sediments. Typically measuring 20-50 m across with depths of 2-10 m, these features often occur in extensive fields containing hundreds of them per square kilometre. They are prominent hazards for offshore installations such as oil rigs and pipelines, affecting vast areas worldwide. Besides, they represent a major geological source of methane, and their importance has been pointed out as contributors to the global climate variability.Sedimentological and biostratigraphic analyses of sediment cores were coupled with shallow seismic images to investigate the origin and evolution of a pockmark field in the southwestern Barents Sea, an epicontinental sea part of the Arctic Ocean. The pockmarks formed as a result of reduced sedimentation above active gas seeps near the retreating edge of the Barents Sea ice sheet about 15,000 years ago. The seepage is ascribed to climate change-induced dissociation of methane hydrates. These findings strengthen the case that pockmarks, worldwide, recorded the release of massive quantities of methane from the seafloor into the ocean during the last deglaciation. No evidence was found for current upward methane flux, so the pockmarks in the study area appear as inactive seabed features. Field measurements of currents and sediment fluxes in pockmarks in the Oslofjord, Norway, along with an experimental hydrodynamics study, provide insight into the mechanisms responsible for the long-term maintenance of inactive pockmarks. Near-bed currents may control the net sedimentation rate in these depressions by inhibiting the sedimentation from suspended transport. Enhanced turbulence and more intense biological activity suggest that the suspended fines are supported in the water column more easily in the pockmarks than on the surrounding bed, and can be transported away before settling. Moreover, upwelling generated by flow deflection

  14. Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

    USGS Publications Warehouse

    Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

    2017-01-01

    Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity–temperature–depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5–8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

  15. Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

    NASA Astrophysics Data System (ADS)

    Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

    2017-02-01

    Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity-temperature-depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5-8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

  16. Lithium and chromospherically active single giants

    NASA Technical Reports Server (NTRS)

    Fekel, Francis C.

    1988-01-01

    Nine chromospherically active single K giants were identified from surveys of chromospherically active stars. The stars have v sin i's ranging from 6 to 46 km/sec. Such large velocities are not explained by scenarios of main sequence to giant star evolution. Fluxes of the ultraviolet emission lines of these stars are substantially less than those of FK Comae. Many of these giants have a moderate or strong lithium line strongly suggesting that these stars recently evolved from rapidly rotating A or early F stars as is suggested by their space motions. Thus, they are not spun down FK Com stars. The characteristics of these stars are such that they may be confused with pre-main sequence stars. The primary difference may be that the post main sequence stars have strong H alpha absorption lines while the pre-main sequence stars appear to have a weak H alpha absorption line or possibly H alpha in emission above the continuum.

  17. More than a century of bathymetric observations and present-day shallow sediment characterization in Belfast Bay, Maine, USA: Implications for pockmark field longevity

    USGS Publications Warehouse

    Brothers, L.L.; Kelley, J.T.; Belknap, D.F.; Barnhardt, W.A.; Andrews, B.D.; Maynard, M.L.

    2011-01-01

    Mechanisms and timescales responsible for pockmark formation and maintenance remain uncertain, especially in areas lacking extensive thermogenic fluid deposits (e.g., previously glaciated estuaries). This study characterizes seafloor activity in the Belfast Bay, Maine nearshore pockmark field using (1) three swath bathymetry datasets collected between 1999 and 2008, complemented by analyses of shallow box-core samples for radionuclide activity and undrained shear strength, and (2) historical bathymetric data (report and smooth sheets from 1872, 1947, 1948). In addition, because repeat swath bathymetry surveys are an emerging data source, we present a selected literature review of recent studies using such datasets for seafloor change analysis. This study is the first to apply the method to a pockmark field, and characterizes macro-scale (>5 m) evolution of tens of square kilometers of highly irregular seafloor. Presence/absence analysis yielded no change in pockmark frequency or distribution over a 9-year period (1999-2008). In that time pockmarks did not detectably enlarge, truncate, elongate, or combine. Historical data indicate that pockmark chains already existed in the 19th century. Despite the lack of macroscopic changes in the field, near-bed undrained shear-strength values of less than 7 kPa and scattered downcore 137Cs signatures indicate a highly disturbed setting. Integrating these findings with independent geophysical and geochemical observations made in the pockmark field, it can be concluded that (1) large-scale sediment resuspension and dispersion related to pockmark formation and failure do not occur frequently within this field, and (2) pockmarks can persevere in a dynamic estuarine setting that exhibits minimal modern fluid venting. Although pockmarks are conventionally thought to be long-lived features maintained by a combination of fluid venting and minimal sediment accumulation, this suggests that other mechanisms may be equally active in

  18. More than a century of bathymetric observations and present-day shallow sediment characterization in Belfast Bay, Maine, USA: implications for pockmark field longevity

    USGS Publications Warehouse

    Brothers, Laura L.; Kelley, Joseph T.; Belknap, Daniel F.; Barnhardt, Walter A.; Andrews, Brian D.; Maynard, Melissa Landon

    2011-01-01

    Mechanisms and timescales responsible for pockmark formation and maintenance remain uncertain, especially in areas lacking extensive thermogenic fluid deposits (e.g., previously glaciated estuaries). This study characterizes seafloor activity in the Belfast Bay, Maine nearshore pockmark field using (1) three swath bathymetry datasets collected between 1999 and 2008, complemented by analyses of shallow box-core samples for radionuclide activity and undrained shear strength, and (2) historical bathymetric data (report and smooth sheets from 1872, 1947, 1948). In addition, because repeat swath bathymetry surveys are an emerging data source, we present a selected literature review of recent studies using such datasets for seafloor change analysis. This study is the first to apply the method to a pockmark field, and characterizes macro-scale (>5 m) evolution of tens of square kilometers of highly irregular seafloor. Presence/absence analysis yielded no change in pockmark frequency or distribution over a 9-year period (1999–2008). In that time pockmarks did not detectably enlarge, truncate, elongate, or combine. Historical data indicate that pockmark chains already existed in the 19th century. Despite the lack of macroscopic changes in the field, near-bed undrained shear-strength values of less than 7 kPa and scattered downcore 137Cs signatures indicate a highly disturbed setting. Integrating these findings with independent geophysical and geochemical observations made in the pockmark field, it can be concluded that (1) large-scale sediment resuspension and dispersion related to pockmark formation and failure do not occur frequently within this field, and (2) pockmarks can persevere in a dynamic estuarine setting that exhibits minimal modern fluid venting. Although pockmarks are conventionally thought to be long-lived features maintained by a combination of fluid venting and minimal sediment accumulation, this suggests that other mechanisms may be equally active in

  19. Shallow stratigraphic control on pockmark distribution in north temperate estuaries

    USGS Publications Warehouse

    Brothers, Laura L.; Kelley, Joseph T.; Belknap, Daniel F.; Barnhardt, Walter A.; Andrews, Brian D.; Legere, Christine; Hughes-Clarke, John E.

    2012-01-01

    Pockmark fields occur throughout northern North American temperate estuaries despite the absence of extensive thermogenic hydrocarbon deposits typically associated with pockmarks. In such settings, the origins of the gas and triggering mechanism(s) responsible for pockmark formation are not obvious. Nor is it known why pockmarks proliferate in this region but do not occur south of the glacial terminus in eastern North America. This paper tests two hypotheses addressing these knowledge gaps: 1) the region's unique sea-level history provided a terrestrial deposit that sourced the gas responsible for pockmark formation; and 2) the region's physiography controls pockmarks distribution. This study integrates over 2500 km of high-resolution swath bathymetry, Chirp seismic reflection profiles and vibracore data acquired in three estuarine pockmark fields in the Gulf of Maine and Bay of Fundy. Vibracores sampled a hydric paleosol lacking the organic-rich upper horizons, indicating that an organic-rich terrestrial deposit was eroded prior to pockmark formation. This observation suggests that the gas, which is presumably responsible for the formation of the pockmarks, originated in Holocene estuarine sediments (loss on ignition 3.5–10%), not terrestrial deposits that were subsequently drowned and buried by mud. The 7470 pockmarks identified in this study are non-randomly clustered. Pockmark size and distribution relate to Holocene sediment thickness (r2 = 0.60), basin morphology and glacial deposits. The irregular underlying topography that dictates Holocene sediment thickness may ultimately play a more important role in temperate estuarine pockmark distribution than drowned terrestrial deposits. These results give insight into the conditions necessary for pockmark formation in nearshore coastal environments.

  20. Chromospheric Activity in Population II Giants

    NASA Technical Reports Server (NTRS)

    Harper, Graham M.

    2004-01-01

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

  1. Pockmark Current Flow Patterns in Belfast Bay, Maine

    NASA Astrophysics Data System (ADS)

    Fandel, C. L.; Lippmann, T. C.; Foster, D. L.; Irish, J. D.; Brothers, L.

    2012-12-01

    Pockmarks are large, circular or elongate depressions in the seafloor that are globally distributed in a wide range of geologic settings including shallow, estuarine environments like Belfast Bay, Maine. The primary mechanism of pockmark formation in Belfast Bay is attributed to episodic methane venting of shallow, natural gas in the area. Recent models suggest pockmarks may be further maintained by the reduction or prevention of fine-grained sediment deposition due to inner-pockmark upwelling events induced by near-bed current flow and flow separation over the depressions. Fluid dynamics around these features may be similar to flow around dimples or cavities. In 2011, we tested this hypothesis by deploying two ADCP moorings at the rim and center of two pockmarks in Belfast Bay, Maine over a two day period. The sampled pockmarks consist of a circular, shallow (33 m) pockmark and a more elongated, deeper (42 m) pockmark, each with a length-to-depth ratio of 2.8. Time-varying current profiles indicate a complex rotational structure with depth, often exceeding 180°. Multiple upwelling and downwelling events extend throughout the water column with vertical velocities reaching up to 0.02 m/s. The shallow pockmark shows greater temporal and spatial variability in rotational structure that may be attributed to the converging tidal flows entering Belfast Bay. Current flow patterns in the deep pockmark are more directionally consistent with the tide and exhibit greater spatial alignment in the upper water column between the rim and center of the pockmark. Both pockmarks exhibit a counter-clockwise rotational pattern on the rising tide as current flow rotates nearly 100° from surface and into the pockmark. As the tide ebbs, a sub-division of flow is observed with a southerly-directed flow in the upper two-thirds of the water column and a northeasterly-directed flow within 10 m of the bottom. This circulation pattern resembles open cavity (L/D < 6) flow explained by

  2. Focused hydrocarbon-migration in shallow sediments of a pockmark cluster in the Niger Delta (Off Nigeria)

    NASA Astrophysics Data System (ADS)

    de Prunelé, Alexis; Ruffine, Livio; Riboulot, Vincent; Peters, Carl A.; Croguennec, Claire; Guyader, Vivien; Pape, Thomas; Bollinger, Claire; Bayon, Germain; Caprais, Jean-Claude; Germain, Yoan; Donval, Jean-Pierre; Marsset, Tania; Bohrmann, Gerhard; Géli, Louis; Rabiu, Abdulkarim; Lescanne, Marc; Cauquil, Eric; Sultan, Nabil

    2017-01-01

    The Niger Delta is one of the largest hydrocarbon basin offshore Africa and it is well known for the presence of active pockmarks on the seabed. During the Guineco-MeBo cruise in 2011, long cores were taken from a pockmark cluster in order to investigate the state of its current activity. Gas hydrates, oil, and pore-water were sampled for geochemical studies. The resulting dataset combined with seismic data reveal that shallow hydrocarbon migration in the upper sedimentary section was focused exclusively within the pockmarks. There is a clear tendency for gas migration within the hydrate-bearing pockmarks, and oil migration within the carbonate-rich one. This trend is interpreted as a consequence of hydrate dissolution followed by carbonate precipitation in the course of the evolution of these pockmarks. We also demonstrate that Anaerobic Oxidation of Methane (AOM) is the main process responsible for the depletion of pore-water sulfate, with depths of the Sulfate-Methane Transition Zone (SMTZ) ranging between 1.8 and 33.4 m. In addition, a numerical transport-reaction model was used to estimate the age of hydrate-layer formation from the present-day sulfate profiles. The results show that the sampled hydrate-layers were formed between 21 and 3750 years before present. Overall, this work shows the importance of fluid flow on the dynamics of pockmarks, and the investigated cluster offers new opportunities for future cross-site comparison studies. Our results imply that sudden discharges of gas can create hydrate layers within the upper sedimentary column which can affect the seafloor morphology over few decades.

  3. Pockmarks in the floor of Penobscot Bay, Maine

    USGS Publications Warehouse

    Scanlon, K.M.; Knebel, H. J.

    1989-01-01

    Hundreds of depressions (pockmarks) were found within a 40 square kilometer area of the sea floor near the head of Penobscot Bay, Maine. These roughly circular depressions range in diameter from 10 to 300 meters and extend as much as 30 meters below the surrounding sea floor. The pockmarks have formed in marine mud of Holocene age, which unconformably overlies glaciomarine deposits. The presence of shallow interstitial gas in the mud suggests that the pockmarks are related to the excipe of gas from the sediments, although other factors must be involved. ?? 1989 Springer-Verlag New York Inc.

  4. [Microbiological and biogeochemical processes in a pockmark of the Gdansk depression, Baltic Sea].

    PubMed

    Pimenov, N V; Ul'ianova, M O; Kanapatski, T A; Sivkov, V V; Ivanov, M V

    2008-01-01

    Comprehensive microbiological and biogeochemical investigation of a pockmark within one of the sites of gas-saturated sediments in the Gdansk depression, Baltic Sea was carried out during the 87th voyage of the Professor Shtokman research vessel. Methane content in the near-bottom water and in the underlying sediments indicates stable methane flow from the sediment into the water. In the 10-m water layer above the pockmark, apart from methane anomalies, elevated numbers of microorganisms and enhanced rates of dark CO2 fixation (up to 1.15 micromol C/(1 day)) and methane oxidation (up to 2.14 nmol CH4/(1 day)) were revealed. Lightened isotopic composition of suspended organic matter also indicates high activity of the near-bottom microbial community. Compared to the background stations, methane content in pockmark sediments increased sharply from the surface to 40-60 ml/dm3 in the 20-30cm horizon. High rates of bacterial sulfate reduction (SR) were detected throughout the core (0-40 cm); the maximum of 74 micromol/(dm3 day) was located in subsurface horizons (15-20 cm). The highest rates of anaerobic methane oxidation (AMO), up to 80 micromol/(dm3 day), were detected in the same horizon. Good coincidence of the AMO and SR profiles with stoichiometry close to 1:1 is evidence in favor of a close relation between these processes performed by a consortium of methanotrophic archaea and sulfate-reducing bacteria. Methane isotopic composition in subsurface sediments of the pockmark (from -53.0 to -56.5% per hundred) does not rule out the presence of methane other than the biogenic methane from the deep horizons of the sedimentary cover.

  5. Chromospheric Activity in Red Giants of M67

    NASA Astrophysics Data System (ADS)

    Dupree, A. K.; Whitney, B. A.; Pasquini, L.

    1994-12-01

    Red giants in the old open cluster M67 present a well-studied, homogeneous group of 1.27Msun stars with which to determine the evolution of chromospheric activity and mass loss. Echelle spectra of the Ca II H and K line region (lambda 3950) have been obtained with the 4-m telescope at KPNO, the MMT of the F. L. Whipple Observatory (K only), and the 3.6-m ESO telescope at La Silla, Chile. Spectra of 16 red giant stars down to V ~ 11 were obtained; five of the sample are identified as clump giants. The flux of the emission reversal in the Ca II K core has been calibrated using normalization based on the narrow-band absolute spectrophotometry of Gunn &\\ Stryker (1983, ApJS, 52, 121). A new spectral synthesis of the Calcium line region for radiative models of the M67 giants based on Kurucz atmospheres provides the correction necessary to extract the chromospheric component of the flux. The Ca K emission reversals display asymmetries indicative of outward motions for giants more luminous than M_V ~ +0.5. The chromospheric emission flux in Ca II K decreases with increasing stellar luminosity. Clump giants, which are thought to be in a core-helium burning stage, show Ca II emission comparable to the stars on the red giant branch. Evidence for chromospheric variability is found from multiple observations of several objects. Implications of these results upon the evolution of chromospheres and presence of mass loss in giants will be discussed.

  6. Automated feature extraction and spatial organization of seafloor pockmarks, Belfast Bay, Maine, USA

    USGS Publications Warehouse

    Andrews, B.D.; Brothers, L.L.; Barnhardt, W.A.

    2010-01-01

    Seafloor pockmarks occur worldwide and may represent millions of m3 of continental shelf erosion, but few numerical analyses of their morphology and spatial distribution of pockmarks exist. We introduce a quantitative definition of pockmark morphology and, based on this definition, propose a three-step geomorphometric method to identify and extract pockmarks from high-resolution swath bathymetry. We apply this GIS-implemented approach to 25km2 of bathymetry collected in the Belfast Bay, Maine USA pockmark field. Our model extracted 1767 pockmarks and found a linear pockmark depth-to-diameter ratio for pockmarks field-wide. Mean pockmark depth is 7.6m and mean diameter is 84.8m. Pockmark distribution is non-random, and nearly half of the field's pockmarks occur in chains. The most prominent chains are oriented semi-normal to the steepest gradient in Holocene sediment thickness. A descriptive model yields field-wide spatial statistics indicating that pockmarks are distributed in non-random clusters. Results enable quantitative comparison of pockmarks in fields worldwide as well as similar concave features, such as impact craters, dolines, or salt pools. ?? 2010.

  7. Shallow-water pockmark formation in temperate estuaries: A consideration of origins in the western gulf of Maine with special focus on Belfast Bay

    USGS Publications Warehouse

    Rogers, J.N.; Kelley, J.T.; Belknap, D.F.; Gontz, A.; Barnhardt, W.A.

    2006-01-01

    A systematic mapping program incorporating more than 5000 km of side scan sonar and seismic reflection tracklines in the western Gulf of Maine has identified more than 70 biogenic natural gas deposits, occupying 311 km 2 in nearshore muddy embayments. Many of these embayments also contain pockmark fields, with some exhibiting geologically active characteristics including the observance of plumes of escaping fluids and sediment. Pockmarks, hemispherically shaped depressions of various size and depths, formed through fluid escape of gas and/or pore water, are sometimes found within or outside gas fields, although many gas fields lack pockmarks altogether. Although the origin of the natural gas remains unclear, if coastal environments at times of lower sea level were similar to the present, numerous lake, wetland, valley fill and estuarine sources of organic-rich material may have formed on the inner shelf. If these deposits survived transgression and remain buried, they are potential gas sources. Intensive mapping of the Belfast Bay pockmark field in 1998 produced the first nearly continuous side scan sonar mosaic of a Gulf of Maine pockmark field with a corresponding 3-dimensional geological model generated from seismic data. Statistical analysis of pockmark geometry, gas deposit loci, and subsurface evidence for gas-enhanced reflectors suggest that gas migration from deeper lateral sources along permeable subsurface strata may be the mechanism for pockmark formation in areas lacking gas-curtain seismic reflections. The coarse-grained transgressive ravinement unconformity between Pleistocene glacial-marine mud and Holocene mud may act as a conduit for distributing methane to the field's margins. ?? 2005 Elsevier B.V. All rights reserved.

  8. Pockmarks on either side of the Strait of Gibraltar: formation from overpressured shallow contourite gas reservoirs and internal wave action during the last glacial sea-level lowstand?

    NASA Astrophysics Data System (ADS)

    León, Ricardo; Somoza, Luis; Medialdea, Teresa; González, Francisco Javier; Gimenez-Moreno, Carmen Julia; Pérez-López, Raúl

    2014-06-01

    Integrating novel and published swath bathymetry (3,980 km2), as well as chirp and high-resolution 2D seismic reflection profiles (2,190 km), this study presents the mapping of 436 pockmarks at water depths varying widely between 370 and 1,020 m on either side of the Strait of Gibraltar. On the Atlantic side in the south-eastern Gulf of Cádiz near the Camarinal Sill, 198 newly discovered pockmarks occur in three well localized and separated fields: on the upper slope ( n=14), in the main channel of the Mediterranean outflow water (MOW, n=160), and on the huge contourite levee of the MOW main channel ( n=24) near the well-known TASYO field. These pockmarks vary in diameter from 60 to 919 m, and are sub-circular to irregularly elongated or lobate in shape. Their slope angles on average range from 3° to 25°. On the Mediterranean side of the strait on the Ceuta Drift of the western Alborán Basin, where pockmarks were already known to occur, 238 pockmarks were identified and grouped into three interconnected fields, i.e. a northern ( n=34), a central ( n=61) and a southern field ( n=143). In the latter two fields the pockmarks are mainly sub-circular, ranging from 130 to 400 m in diameter with slope angles averaging 1.5° to 15°. In the northern sector, by contrast, they are elongated up to 1,430 m, probably reflecting MOW activity. Based on seismo-stratigraphic interpretation, it is inferred that most pockmarks formed during and shortly after the last glacial sea-level lowstand, as they are related to the final erosional discontinuity sealed by Holocene transgressive deposits. Combining these findings with other existing knowledge, it is proposed that pockmark formation on either side of the Strait of Gibraltar resulted from gas and/or sediment pore-water venting from overpressured shallow gas reservoirs entrapped in coarse-grained contourites of levee deposits and Pleistocene palaeochannel infillings. Venting was either triggered or promoted by hydraulic pumping

  9. Giant cell arteritis associated with chronic active Epstein-Barr virus infection.

    PubMed

    Giardina, A; Rizzo, A; Ferrante, A; Capra, G; Triolo, G; Ciccia, F

    2013-03-28

    Giant cell arteritis is an inflammatory vasculopathy that preferentially affects medium-sized and large arteries. A viral cause has been suspected but not confirmed in polymyalgia rheumatica and giant-cell arteritis. We report the case of a 81-year-old female who suffered from chronic active Epstein-Barr virus infection and developed giant cell temporal arteritis.

  10. Seismic Studies of Paleo-Pockmarks on the Chatham Rise, New Zealand

    NASA Astrophysics Data System (ADS)

    Smith, A. E.; Pecher, I. A.; Davy, B. W.; Coffin, R. B.; Rose, P. S.

    2015-12-01

    This study investigates buried pockmark features on the Chatham Rise through the analysis and interpretation of 2D seismic and Parasound data. The main objectives of this research are to establish what caused the formation of buried pockmarks on the Chatham Rise and to determine when the pockmarks were formed. The study area is located on the Western Chatham Rise, near the Canterbury Shelf off the East Coast of New Zealand. The pockmark fields were revealed through multibeam bathymetry data collected from surveys during the past 20 years. Previously, the pockmarks on the Chatham Rise were thought to have been produced by the release of methane through gas hydrate dissociation. However, recent geochemical investigations showed no indication of methane in the sediment cores. Current hypotheses for the formation of the pockmarks include groundwater fluid flow and the release of CO2 modulated by CO2 hydrates. We present the results of the spatial analysis of the pockmarks on the Western Chatham Rise and whether there are any links between the location of pockmark formation and regional geology. The structures of the pockmarks were investigated to determine how the features were formed. The spatial configuration of the pockmarks were analysed vertically for stacking and laterally for potential ties to specific horizons, particularly horizons associated with Milankovitch order climate cycles. Results show stacking and clustering of pockmarks around specific horizons and a depth window in the upper sediment in which pockmarks are formed. 2D seismic data was interpreted to build a regional geology model, through relative stratigraphy from intersecting seismic lines through the survey area. This improves the current understanding of the stratigraphy along the Chatham Rise and Canterbury Shelf areas and places the pockmark field in a regional geologic context.

  11. Dynamo action and magnetic activity of the giant star Pollux

    NASA Astrophysics Data System (ADS)

    Brun, Allan Sacha; Palacios, Ana

    2015-08-01

    Recent spectropolarimetric observations of the giant star Pollux have revealed that it possesses a weak global magnetic field of the order of a Gauss. Using 3-D nonlinear MHD simulations performed with the ASH code we study the source of this global magnetic field in this slowly rotating giant star (Omega*=Omega_sun/20). We find that the extended convective envelope is able to generate a multi-scales magnetic field reaching of the order of 10% of the kinetic energy contained in the envelope. This global field acts such as to suppress the strong differential rotation present in the purely hydrodynamical progenitor simulation. When filtering the large scale magnetic field components (dipole, quadrupole) we find magnetic field of the order of a few Gauss, hence in qualitative agreeement with observations. Our study confirms that such slowly rotating convective giants are likely to possess global magnetic field maintained through contemporaneous dynamo action and not as the vestige of their past main sequence activity.

  12. Distribution of anaerobic methane-oxidizing and sulfate-reducing communities in the G11 Nyegga pockmark, Norwegian Sea.

    PubMed

    Lazar, Cassandre Sara; Dinasquet, Julie; L'Haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

    2011-11-01

    Pockmarks are seabed geological structures sustaining methane seepage in cold seeps. Based on RNA-derived sequences the active fraction of the archaeal community was analysed in sediments associated with the G11 pockmark, in the Nyegga region of the Norwegian Sea. The anaerobic methanotrophic Archaea (ANME) and sulfate-reducing bacteria (SRB) communities were studied as well. The vertical distribution of the archaeal community assessed by PCR-DGGE highlighted the presence of ANME-2 in surface sediments, and ANME-1 in deeper sediments. Enrichments of methanogens showed the presence of hydrogenotrophic methanogens of the Methanogenium genus in surface sediment layers as well. The active fraction of the archaeal community was uniquely composed of ANME-2 in the shallow sulfate-rich sediments. Functional methyl coenzyme M reductase gene libraries showed that sequences affiliated with the ANME-1 and ANME-3 groups appeared in the deeper sediments but ANME-2 dominated both surface and deeper layers. Finally, dissimilatory sulfite reductase gene libraries revealed a high SRB diversity (i.e. Desulfobacteraceae, Desulfobulbaceae, Syntrophobacteraceae and Firmicutes) in the shallow sulfate-rich sediments. The SRB diversity was much lower in the deeper section. Overall, these results show that the microbial community in sediments associated with a pockmark harbour classical cold seep ANME and SRB communities.

  13. Activity syndromes and metabolism in giant deep-sea isopods

    NASA Astrophysics Data System (ADS)

    Wilson, Alexander D. M.; Szekeres, Petra; Violich, Mackellar; Gutowsky, Lee F. G.; Eliason, Erika J.; Cooke, Steven J.

    2017-03-01

    Despite growing interest, the behavioural ecology of deep-sea organisms is largely unknown. Much of this scarcity in knowledge can be attributed to deepwater animals being secretive or comparatively 'rare', as well as technical difficulties associated with accessing such remote habitats. Here we tested whether two species of giant marine isopod (Bathynomus giganteus, Booralana tricarinata) captured from 653 to 875 m in the Caribbean Sea near Eleuthera, The Bahamas, exhibited an activity behavioural syndrome across two environmental contexts (presence/absence of food stimulus) and further whether this syndrome carried over consistently between sexes. We also measured routine metabolic rate and oxygen consumption in response to a food stimulus in B. giganteus to assess whether these variables are related to individual differences in personality. We found that both species show an activity syndrome across environmental contexts, but the underlying mechanistic basis of this syndrome, particularly in B. giganteus, is unclear. Contrary to our initial predictions, neither B. giganteus nor B. tricarinata showed any differences between mean expression of behavioural traits between sexes. Both sexes of B. tricarinata showed strong evidence of an activity syndrome underlying movement and foraging ecology, whereas only male B. giganteus showed evidence of an activity syndrome. Generally, individuals that were more active and bolder, in a standard open arena test were also more active when a food stimulus was present. Interestingly, individual differences in metabolism were not related to individual differences in behaviour based on present data. Our study provides the first measurements of behavioural syndromes and metabolism in giant deep-sea isopods.

  14. MOLECULAR CLONING, SEQUENCING, EXPRESSION AND BIOLOGICAL ACTIVITY OF GIANT PANDA (AILUROPODA MELANOLEUCA) INTERFERON-GAMMA.

    PubMed

    Zhu, Hui; Wang, Wen-Xiu; Wang, Bao-Qin; Zhu, Xiao-Fu; Wu, Xu-Jin; Ma, Qing-Yi; Chen, De-Kun

    2012-06-29

    The giant panda (Ailuropoda melanoleuca) is an endangered species and indigenous to China. Interferon-gamma (IFN-γ) is the only member of type □ IFN and is vital for the regulation of host adapted immunity and inflammatory response. Little is known aboutthe FN-γ gene and its roles in giant panda.In this study, IFN-γ gene of Qinling giant panda was amplified from total blood RNA by RT-CPR, cloned, sequenced and analysed. The open reading frame (ORF) of Qinling giant panda IFN-γ encodes 152 amino acidsand is highly similar to Sichuan giant panda with an identity of 99.3% in cDNA sequence. The IFN-γ cDNA sequence was ligated to the pET32a vector and transformed into E. coli BL21 competent cells. Expression of recombinant IFN-γ protein of Qinling giant panda in E. coli was confirmed by SDS-PAGE and Western blot analysis. Biological activity assay indicated that the recombinant IFN-γ protein at the concentration of 4-10 µg/ml activated the giant panda peripheral blood lymphocytes,while at 12 µg/mlinhibited. the activation of the lymphocytes.These findings provide insights into the evolution of giant panda IFN-γ and information regarding amino acid residues essential for their biological activity.

  15. Observations of pockmark flow structure in Belfast Bay, Maine, Part 2: evidence for cavity flow

    NASA Astrophysics Data System (ADS)

    Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.

    2017-02-01

    Pockmark flow circulation patterns were investigated through current measurements along the rim and center of two pockmarks in Belfast Bay, Maine. Observed time-varying current profiles have a complex vertical and directional structure that rotates significantly with depth and is strongly dependent on the phase of the tide. Observations of the vertical profiles of horizontal velocities in relation to relative geometric parameters of the pockmark are consistent with circulation patterns described qualitatively by cavity flow models (Ashcroft and Zhang 2005). The time-mean behavior of the shear layer is typically used to characterize cavity flow, and was estimated using vorticity thickness to quantify the growth rate of the shear layer horizontally across the pockmark. Estimated positive vorticity thickness spreading rates are consistent with cavity flow predictions, and occur at largely different rates between the two pockmarks. Previously modeled flow (Brothers et al. 2011) and laboratory measurements (Pau et al. 2014) over pockmarks of similar geometry to those examined herein are also qualitatively consistent with cavity flow circulation, suggesting that cavity flow may be a good first-order flow model for pockmarks in general.

  16. Observations of pockmark flow structure in Belfast Bay, Maine, Part 2: evidence for cavity flow

    USGS Publications Warehouse

    Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.

    2017-01-01

    Pockmark flow circulation patterns were investigated through current measurements along the rim and center of two pockmarks in Belfast Bay, Maine. Observed time-varying current profiles have a complex vertical and directional structure that rotates significantly with depth and is strongly dependent on the phase of the tide. Observations of the vertical profiles of horizontal velocities in relation to relative geometric parameters of the pockmark are consistent with circulation patterns described qualitatively by cavity flow models (Ashcroft and Zhang 2005). The time-mean behavior of the shear layer is typically used to characterize cavity flow, and was estimated using vorticity thickness to quantify the growth rate of the shear layer horizontally across the pockmark. Estimated positive vorticity thickness spreading rates are consistent with cavity flow predictions, and occur at largely different rates between the two pockmarks. Previously modeled flow (Brothers et al. 2011) and laboratory measurements (Pau et al. 2014) over pockmarks of similar geometry to those examined herein are also qualitatively consistent with cavity flow circulation, suggesting that cavity flow may be a good first-order flow model for pockmarks in general.

  17. Pockmark asymmetry and seafloor currents in the Santos Basin offshore Brazil

    NASA Astrophysics Data System (ADS)

    Schattner, U.; Lazar, M.; Souza, L. A. P.; ten Brink, U.; Mahiques, M. M.

    2016-12-01

    Pockmarks form by gas/fluid expulsion into the ocean and are preserved under conditions of negligible sedimentation. Ideally, they are circular at the seafloor and symmetrical in profile. Elliptical pockmarks are more enigmatic. They are associated with seafloor currents while asymmetry is connected to sedimentation patterns. This study examines these associations through morphological analysis of new multibeam data collected across the Santos continental slope offshore Brazil in 2011 (353-865 mbsl). Of 984 pockmarks, 78% are both elliptical and asymmetric. Geometric criteria divide the pockmarks into three depth ranges that correlate with a transition between two currents: the Brazil Current transfers Tropical Water and South Atlantic Central Water southwestwards while the Intermediate Western Boundary Current transfers Antarctic Intermediate Water northeastwards. It is suggested that the velocity of seafloor currents and their persistence dictate pockmark ellipticity, orientation and profile asymmetry. Fast currents (>20 cm/s) are capable of maintaining pockmark flank steepness close to the angle of repose. These morphological expressions present direct evidence for an edge effect of the South Atlantic Subtropical Gyre and, in general, provide a correlation between pockmark geometry and seafloor currents that can be applied at other locations worldwide.

  18. Pockmark asymmetry and seafloor currents in the Santos Basin offshore Brazil

    USGS Publications Warehouse

    Schattner, U.; Lazar, M.; Souza, L. A. P.; Brink, Uri ten; Mahiques, M. M.

    2016-01-01

    Pockmarks form by gas/fluid expulsion into the ocean and are preserved under conditions of negligible sedimentation. Ideally, they are circular at the seafloor and symmetrical in profile. Elliptical pockmarks are more enigmatic. They are associated with seafloor currents while asymmetry is connected to sedimentation patterns. This study examines these associations through morphological analysis of new multibeam data collected across the Santos continental slope offshore Brazil in 2011 (353–865 mbsl). Of 984 pockmarks, 78% are both elliptical and asymmetric. Geometric criteria divide the pockmarks into three depth ranges that correlate with a transition between two currents: the Brazil Current transfers Tropical Water and South Atlantic Central Water southwestwards while the Intermediate Western Boundary Current transfers Antarctic Intermediate Water northeastwards. It is suggested that the velocity of seafloor currents and their persistence dictate pockmark ellipticity, orientation and profile asymmetry. Fast currents (>20 cm/s) are capable of maintaining pockmark flank steepness close to the angle of repose. These morphological expressions present direct evidence for an edge effect of the South Atlantic Subtropical Gyre and, in general, provide a correlation between pockmark geometry and seafloor currents that can be applied at other locations worldwide.

  19. Origin of pockmarks and chimney structures on the flanks of the Storegga Slide, offshore Norway

    USGS Publications Warehouse

    Paull, C.K.; Ussler, W.; Holbrook, W.S.; Hill, T.M.; Keaten, R.; Mienert, J.; Haflidason, H.; Johnson, J.E.; Winters, W.J.; Lorenson, T.D.

    2008-01-01

    Seafloor pockmarks and subsurface chimney structures are common on the Norwegian continental margin north of the Storegga Slide scar. Such features are generally inferred to be associated with fluid expulsion, and imply overpressures in the subsurface. Six long gravity and piston cores taken from the interior of three pockmarks were compared with four other cores taken from the same area but outside the pockmarks, in order to elucidate the origins and stratigraphy of these features and their possible association with the Storegga Slide event. Sulfate gradients in cores from within pockmarks are less steep than those in cores from outside the pockmarks, which indicates that the flux of methane to the seafloor is presently smaller within the pockmarks than in the adjacent undisturbed sediments. This suggests that these subsurface chimneys are not fluid flow conduits lined with gas hydrate. Methane-derived authigenic carbonates and Bathymodiolus shells obtained from a pockmark at >6.3 m below the seafloor indicate that methane was previously available to support a chemosynthetic community within the pockmark. AMS 14C measurements of planktonic Foraminifera overlying and interlayered with the shell-bearing sediment indicate that methane was present on the seafloor within the pockmark prior to 14 ka 14C years B.P., i.e., well before the last major Storegga Slide event (7.2 ka 14C years B.P., or 8.2 ka calendar years B.P.). These observations provide evidence that overpressured fluids existed within the continental margin sediments off Norway during the last major advance of Pleistocene glaciation. ?? Springer-Verlag 2007.

  20. Observations of pockmark flow structure in Belfast Bay, Maine, Part 3: implications for sediment transport

    NASA Astrophysics Data System (ADS)

    Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.

    2017-02-01

    Current observations and sediment characteristics acquired within and along the rim of two pockmarks in Belfast Bay, Maine, were used to characterize periods of sediment transport and to investigate conditions favorable to the settling of suspended sediment. Hourly averaged Shields parameters determined from horizontal current velocity profiles within the center of each pockmark never exceed the critical value (approximated with the theoretical model of Dade et al. 1992). However, Shields parameters estimated at the pockmark rims periodically exceed the critical value, consistent with conditions that support the onset of sediment transport and suspension. Below the rim in the near-center of each pockmark, depth-averaged vertical velocities were less than zero (downward) 60% and 55% of the time in the northern and southern pockmarks, and were often comparable to depth-averaged horizontal velocities. Along the rim, depth-averaged vertical velocities over the lower 8 m of the water column were primarily downward but much less than depth-averaged horizontal velocities indicating that suspended sediment may be moved to distant locations. Maximum grain sizes capable of remaining in suspension under terminal settling flow conditions (ranging 10-170 μm) were typically much greater than the observed median grain diameter (about 7 μm) at the bed. During upwelling flow within the pockmarks, and in the absence of flocculation, suspended sediment would not settle. The greater frequency of predicted periods of sediment transport along the rim of the southern pockmark is consistent with pockmark morphology in Belfast Bay, which transitions from more spherical to more elongated toward the south, suggesting near-bed sediment transport may contribute to post-formation pockmark evolution during typical conditions in Belfast Bay.

  1. Observations of pockmark flow structure in Belfast Bay, Maine, Part 3: implications for sediment transport

    USGS Publications Warehouse

    Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.

    2017-01-01

    Current observations and sediment characteristics acquired within and along the rim of two pockmarks in Belfast Bay, Maine, were used to characterize periods of sediment transport and to investigate conditions favorable to the settling of suspended sediment. Hourly averaged Shields parameters determined from horizontal current velocity profiles within the center of each pockmark never exceed the critical value (approximated with the theoretical model of Dade et al. 1992). However, Shields parameters estimated at the pockmark rims periodically exceed the critical value, consistent with conditions that support the onset of sediment transport and suspension. Below the rim in the near-center of each pockmark, depth-averaged vertical velocities were less than zero (downward) 60% and 55% of the time in the northern and southern pockmarks, and were often comparable to depth-averaged horizontal velocities. Along the rim, depth-averaged vertical velocities over the lower 8 m of the water column were primarily downward but much less than depth-averaged horizontal velocities indicating that suspended sediment may be moved to distant locations. Maximum grain sizes capable of remaining in suspension under terminal settling flow conditions (ranging 10–170 μm) were typically much greater than the observed median grain diameter (about 7 μm) at the bed. During upwelling flow within the pockmarks, and in the absence of flocculation, suspended sediment would not settle. The greater frequency of predicted periods of sediment transport along the rim of the southern pockmark is consistent with pockmark morphology in Belfast Bay, which transitions from more spherical to more elongated toward the south, suggesting near-bed sediment transport may contribute to post-formation pockmark evolution during typical conditions in Belfast Bay.

  2. Observed temporal hydrate-pingo alteration at pockmark G11, Nyegga, - an important climate-change signal?

    NASA Astrophysics Data System (ADS)

    Hovland, M. T.

    2010-12-01

    Complex pockmark G11 at Nyegga, occurs adjacent to the northern flank of the Storegga Slide, off mid-Norway. It is a 12 m deep and 200 - 250 m wide oval-shaped depression at ~750 m water depth. The crater-like depression contains at least six up to 4 m wide and 2 m high hydrate-pingoes in addition to large, rugged methane-derived carbonate rock ridges. Despite an ambient sub-zero water temperature (~ - 0.7 °C), the pockmark teems with life, ranging from primary producers, e.g., chemosynthetic bacteria to higher trophic animals, including filter-feeders, stalked crinoids, large pycnogonids, and various kinds of teleostei, mainly skate and eel pout. One of the circular, cylinder-shaped hydrate pingoes (‘Ice1’, Hovland and Svensen, 2006), was measured in 2004 to be about 1 m in diameter and 25 cm high. It was re-visited with ROV (remotely operated vehicle) in 2009 and was found to have slightly altered its shape and become slightly smaller. The features of the G11-pockmark, including bacterial mats, sampled gas hydrates, high biodiversity, and hydrate-pingoes documents that active fluid flow (seepage) occurs through the seafloor. Although the currently observed activity at G11 seems to be in a mode of slow, steady-state flux, e.g., ‘micro-seepage’, slightly warmer bottom water expected as a consequence of the global warming trend may induce a ‘galloping melting’ or dramatically increased seepage flux in the near future. During the last few years, there has been a trend of ocean bottom water warming along most of the 1500 km long western Norwegian coastline with up to 0.8°C above normal (www.imr.no). If this same trend also occurs at 750 m water depth at Nyegga, about 170 km west of the coastline, then there is a danger of escalating pingo-alteration at G11. Because of its easy access for research vessels and its well-documented near-surface features, G11/Nyegga represents an ideal location for the early-warning documentation of incipient hydrate

  3. Hydrate dissolution as a potential mechanism for pockmark formation in the Niger delta

    NASA Astrophysics Data System (ADS)

    Sultan, N.; Marsset, B.; Ker, S.; Marsset, T.; Voisset, M.; Vernant, A. M.; Bayon, G.; Cauquil, E.; Adamy, J.; Colliat, J. L.; Drapeau, D.

    2010-08-01

    Based on acquired geophysical, geological and geotechnical data and modeling, we suggest hydrate dissolution to cause sediment collapse and pockmark formation in the Niger delta. Very high-resolution bathymetry data acquired from the Niger delta reveal the morphology of pockmarks with different shapes and sizes going from a small ring depression surrounding an irregular floor to more typical pockmarks with uniform depression. Geophysical data, in situ piezocone measurements, piezometer measurements and sediment cores demonstrate the presence of a common internal architecture of the studied pockmarks: inner sediments rich in gas hydrates surrounded by overpressured sediments. The temperature, pressure and salinity conditions of the studied area have allowed us to exclude the process of gas-hydrate dissociation (gas hydrate turns into free gas/water mixture) as a trigger of the observed pockmarks. Based on numerical modeling, we demonstrate that gas-hydrate dissolution (gas hydrate becomes mixture of water and dissolved gas) under a local decrease of the gas concentration at the base of the gas-hydrate occurrence zone (GHOZ) can explain the excess pore pressure and fluid flow surrounding the central hydrated area and the sediment collapse at the border of the GHOZ. The different deformation (or development) stages of the detected pockmarks confirm that a local process such as the amount of gas flow through faults rather than a regional one is at the origin of those depressions.

  4. Biogeochemical and microbiological characteristic of the pockmark sediments, the Gdansk Deep, The Baltic Sea

    NASA Astrophysics Data System (ADS)

    Pimenov, Nikolay; Kanapatskiy, Timur; Sivkov, Vadim; Toshchakov, Stepan; Korzhenkov, Aleksei; Ulyanova, Marina

    2016-04-01

    Comparison of the biogeochemical and microbial features was done for the gas-bearing and background sediments as well as near-bottom water of the Gdansk Deep, The Baltic Sea. Data were received in October, 2015 during 64th cruise of the R/V Akademik Mstislav Keldysh. Gas-bearing sediments were sampled within the known pockmark (Gas-Point, depth 94 m). Background sediments area (BG-Point, depth 86 m) was located several km off the pockmark area. The sulphate concentration in the pore water of the surface sediment layer (0-5 cm) of Gas-Point was 9,7 mmol/l, and sharply decreased with depth (did not exceed 1 mmol/l deeper than 50 cm). The sulphate concentration decrease at BG-Point also took place but was not so considerable. Sulphate concentration decrease is typical for the organic rich sediments of the high productive areas, both as for the methane seep areas. Fast sulphate depletion occurs due to active processes of its microbial reduction by consortium of the sulphate-reduction bacteria, which may use low-molecular organic compounds or hydrogen, formed at the different stages of the organic matter destruction; as well as within the process of the anaerobic methane oxidation by consortium of the methane-trophic archaea and sulphate-reduction bacteria. Together with sulphate concentration decrease the methane content increase, typical for the marine sediments, occurred. At the Gas-Point the methane concentration varied within 10 μmol/dm3 in the surface layer till its maximum at sediment horizon of 65 cm (5 mmol/dm3), and decreased to 1.5 mmol/dm3 at depth of 300 cm. The BG-Point maximum values were defined at sediment horizon 6 cm (2,6 μmol/dm3). Methane sulfate transition zone at the Gas-Point sediments was at 25-35 cm depth; whereas it was not defined at the BG-Point mud. High methane concentration in the gas-bearing sediments results in the formation of the methane seep from the sediments to the near-bottom water. So the Gas-Point near-bottom waters were

  5. The magnetic fields at the surface of active single G-K giants

    NASA Astrophysics Data System (ADS)

    Aurière, M.; Konstantinova-Antova, R.; Charbonnel, C.; Wade, G. A.; Tsvetkova, S.; Petit, P.; Dintrans, B.; Drake, N. A.; Decressin, T.; Lagarde, N.; Donati, J.-F.; Roudier, T.; Lignières, F.; Schröder, K.-P.; Landstreet, J. D.; Lèbre, A.; Weiss, W. W.; Zahn, J.-P.

    2015-02-01

    Aims: We investigate the magnetic field at the surface of 48 red giants selected as promising for detection of Stokes V Zeeman signatures in their spectral lines. In our sample, 24 stars are identified from the literature as presenting moderate to strong signs of magnetic activity. An additional 7 stars are identified as those in which thermohaline mixing appears not to have occured, which could be due to hosting a strong magnetic field. Finally, we observed 17 additional very bright stars which enable a sensitive search to be performed with the spectropolarimetric technique. Methods: We use the spectropolarimeters Narval and ESPaDOnS to detect circular polarization within the photospheric absorption lines of our targets. We treat the spectropolarimetric data using the least-squares deconvolution method to create high signal-to-noise ratio mean Stokes V profiles. We also measure the classical S-index activity indicator for the Ca ii H&K lines, and the stellar radial velocity. To infer the evolutionary status of our giants and to interpret our results, we use state-of-the-art stellar evolutionary models with predictions of convective turnover times. Results: We unambiguously detect magnetic fields via Zeeman signatures in 29 of the 48 red giants in our sample. Zeeman signatures are found in all but one of the 24 red giants exhibiting signs of activity, as well as 6 out of 17 bright giant stars. However no detections were obtained in the 7 thermohaline deviant giants. The majority of the magnetically detected giants are either in the first dredge up phase or at the beginning of core He burning, i.e. phases when the convective turnover time is at a maximum: this corresponds to a "magnetic strip" for red giants in the Hertzsprung-Russell diagram. A close study of the 16 giants with known rotational periods shows that the measured magnetic field strength is tightly correlated with the rotational properties, namely to the rotational period and to the Rossby number Ro

  6. Active season microhabitat and vegetation selection by giant gartersnakes associated with a restored marsh in California

    USGS Publications Warehouse

    Halstead, Brian J.; Valcarcel, Patricia; Wylie, Glenn D.; Coates, Peter S.; Casazza, Michael L.; Rosenberg, Daniel K.

    2016-01-01

    Studies of habitat selection can reveal important patterns to guide habitat restoration and management for species of conservation concern. Giant gartersnakes Thamnophis gigas are endemic to the Central Valley of California, where >90% of their historical wetland habitat has been converted to agricultural and other uses. Information about the selection of habitats by individual giant gartersnakes would guide habitat restoration by indicating which habitat features and vegetation types are likely to be selected by these rare snakes. We examined activity patterns and selection of microhabitats and vegetation types by adult female giant gartersnakes with radiotelemetry at a site composed of rice agriculture and restored wetlands using a paired case-control study design. Adult female giant gartersnakes were 14.7 (95% credible interval [CRI] = 9.4–23.7) times more likely to be active (foraging, mating, or moving) when located in aquatic habitats than when located in terrestrial habitats. Microhabitats associated with cover—particularly emergent vegetation, terrestrial vegetation, and litter—were positively selected by giant gartersnakes. Individual giant gartersnakes varied greatly in their selection of rice and rock habitats, but varied little in their selection of open water. Tules Schoenoplectus acutus were the most strongly selected vegetation type, and duckweed Lemna spp., water-primrose Ludwigia spp., forbs, and grasses also were positively selected at the levels of availability observed at our study site. Management practices that promote the interface of water with emergent aquatic and herbaceous terrestrial vegetation will likely benefit giant gartersnakes. Given their strong selection of tules, restoration of native tule marshes will likely provide the greatest benefit to these threatened aquatic snakes.

  7. Pockmark formation and evolution in deep water Nigeria: Rapid hydrate growth versus slow hydrate dissolution

    NASA Astrophysics Data System (ADS)

    Sultan, N.; Bohrmann, G.; Ruffine, L.; Pape, T.; Riboulot, V.; Colliat, J.-L.; De Prunelé, A.; Dennielou, B.; Garziglia, S.; Himmler, T.; Marsset, T.; Peters, C. A.; Rabiu, A.; Wei, J.

    2014-04-01

    In previous works, it has been suggested that dissolution of gas hydrate can be responsible for pockmark formation and evolution in deep water Nigeria. It was shown that those pockmarks which are at different stages of maturation are characterized by a common internal architecture associated to gas hydrate dynamics. New results obtained by drilling into gas hydrate-bearing sediments with the MeBo seafloor drill rig in concert with geotechnical in situ measurements and pore water analyses indicate that pockmark formation and evolution in the study area are mainly controlled by rapid hydrate growth opposed to slow hydrate dissolution. On one hand, positive temperature anomalies, free gas trapped in shallow microfractures near the seafloor and coexistence of free gas and gas hydrate indicate rapid hydrate growth. On the other hand, slow hydrate dissolution is evident by low methane concentrations and almost constant sulfate values 2 m above the Gas Hydrate Occurrence Zone.

  8. Complete genome sequence analysis of a duck circovirus from Guangxi pockmark ducks.

    PubMed

    Xie, Liji; Xie, Zhixun; Zhao, Guangyuan; Liu, Jiabo; Pang, Yaoshan; Deng, Xianwen; Xie, Zhiqin; Fan, Qing

    2012-12-01

    We report here the complete genomic sequence of a novel duck circovirus (DuCV) strain, GX1104, isolated from Guangxi pockmark ducks in Guangxi, China. The whole nucleotide sequence had the highest homology (97.2%) with the sequence of strain TC/2002 (GenBank accession number AY394721.1) and had a low homology (76.8% to 78.6%) with the sequences of other strains isolated from China, Germany, and the United States. This report will help to understand the epidemiology and molecular characteristics of Guangxi pockmark duck circovirus in southern China.

  9. Giant Electron-Hole Interactions in Confined Layered Structures for Molecular Oxygen Activation.

    PubMed

    Wang, Hui; Chen, Shichuan; Yong, Dingyu; Zhang, Xiaodong; Li, Shuang; Shao, Wei; Sun, Xianshun; Pan, Bicai; Xie, Yi

    2017-04-05

    Numerous efforts have been devoted to understanding the excitation processes of photocatalysts, whereas the potential Coulomb interactions between photogenerated electrons and holes have been long ignored. Once these interactions are considered, excitonic effects will arise that undoubtedly influence the sunlight-driven catalytic processes. Herein, by taking bismuth oxyhalide as examples, we proposed that giant electron-hole interactions would be expected in confined layered structures, and excitons would be the dominating photoexcited species. Photocatalytic molecular oxygen activation tests were performed as a proof of concept, where singlet oxygen generation via energy transfer process was brightened. Further experiments verify that structural confinement is curial to the giant excitonic effects, where the involved catalytic process could be readily regulated via facet-engineering, thus enabling diverse reactive oxygen species generation. This study not only provides an excitonic prospective on photocatalytic processes, but also paves a new approach for pursuing systems with giant electron-hole interactions.

  10. What Makes Red Giants Tick? Linking Tidal Forces, Activity, and Solar-Like Oscillations via Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Rawls, Meredith L.; Gaulme, Patrick; McKeever, Jean; Jackiewicz, Jason

    2016-01-01

    Thanks to advances in asteroseismology, red giants have become astrophysical laboratories for studying stellar evolution and probing the Milky Way. However, not all red giants show solar-like oscillations. It has been proposed that stronger tidal interactions from short-period binaries and increased magnetic activity on spotty giants are linked to absent or damped solar-like oscillations, yet each star tells a nuanced story. In this work, we characterize a subset of red giants in eclipsing binaries observed by Kepler. The binaries exhibit a range of orbital periods, solar-like oscillation behavior, and stellar activity. We use orbital solutions together with a suite of modeling tools to combine photometry and spectroscopy in a detailed analysis of tidal synchronization timescales, star spot activity, and stellar evolution histories. These red giants offer an unprecedented opportunity to test stellar physics and are important benchmarks for ensemble asteroseismology.

  11. Surface activity and oscillation amplitudes of red giants in eclipsing binaries

    SciTech Connect

    Gaulme, P.; Jackiewicz, J.; Appourchaux, T.; Mosser, B.

    2014-04-10

    Among the 19 red-giant stars belonging to eclipsing binary systems that have been identified in Kepler data, 15 display solar-like oscillations. We study whether the absence of mode detection in the remaining 4 is an observational bias or possibly evidence of mode damping that originates from tidal interactions. A careful analysis of the corresponding Kepler light curves shows that modes with amplitudes that are usually observed in red giants would have been detected if they were present. We observe that mode depletion is strongly associated with short-period systems, in which stellar radii account for 16%-24% of the semi-major axis, and where red-giant surface activity is detected. We suggest that when the rotational and orbital periods synchronize in close binaries, the red-giant component is spun up, so that a dynamo mechanism starts and generates a magnetic field, leading to observable stellar activity. Pressure modes would then be damped as acoustic waves dissipate in these fields.

  12. Giant piezoelectricity on Si for hyper-active MEMS

    NASA Astrophysics Data System (ADS)

    Eom, Chang-Beom

    2011-03-01

    Smart materials that can sense, manipulate, and position are crucial to the functionality of micro- and nano-machines. Integration of single crystal piezoelectric films on silicon offers the opportunity of high performance piezoelectric microelectromechanical systems (MEMS) incorporating all the advantages of large scale integration on silicon substrates with on-board electronic circuits, improving performance and eliminating common failure points associated with heterogeneous integration. We have fabricated oxide heterostructures with the highest piezoelectric coefficients and figure of merit for piezoelectric energy harvesting system ever realized on silicon substrates by synthesizing epitaxial thin films of Pb(Mg 1/3 Nb 2/3) O3 - PbTi O3 (PMN-PT) on vicinal (001) Si wafers using an epitaxial (001) SrTi O3 template layer. We have also demonstrated fabrication of PMN-PT cantilevers, whose mechanical behavior is consistent with theoretical calculations using the material constants of a bulk PMN-PT single crystal. These epitaxial heterostructures with giant piezoelectricity can be used for MEMS or NEMS devices that function with low drive voltage such as transducers for ultrasound medical imaging, micro-fluidic control and energy harvesting. Beyond electromechanical devices, our approach will open a new avenue to tune and modulate the properties of other multifunctional materials by dynamic strain control. This work was done in collaboration with S. H. Baek, J. Park, D. M. Kim, V. Aksyuk, R. R. Das, S. D. Bu, D. A. Felker, J. Lettieri, V. Vaithyanathan, S. S. N. Bharadwaja, N. Bassiri-Gharb, Y. B. Chen, H. P. Sun, H. W. Jang, D. J. Kreft, S. K. Streiffer, R. Ramesh, X. Q. Pan, S. Trolier-McKinstry, D. G. Schlom, M. S. Rzchowski, R. Blick. This work was supported by the National Science Foundation through grants ECCS-0708759.

  13. The activation pattern of macrophages in giant cell (temporal) arteritis and primary angiitis of the central nervous system.

    PubMed

    Mihm, Bernhard; Bergmann, Markus; Brück, Wolfgang; Probst-Cousin, Stefan

    2014-06-01

    To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14-positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8-positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8-positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process.

  14. Chromospherically active stars. 6: Giants with compact hot companions and the barium star scenario

    NASA Technical Reports Server (NTRS)

    Fekel, Francis C.; Henry, Gregory W.; Busby, Michael R.; Eitter, Joseph J.

    1993-01-01

    We have determined spectroscopic orbits for three chromospherically active giants that have hot compact companions. They are HD 160538 (K0 III + wd, P = 904 days), HD 165141 (G8 III + wd, P approximately 5200 days), and HD 185510 (K0 III + sdB, P = 20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion of HD 165141 has a temperature of about 35000 K. Spectral types and rotational velocities have been determined for the three giants and distances have been estimated. These three systems and 39 Ceti are compared with the barium star mass-transfer scenario. The long-period mild barium giant HD 165141 as well as HD 185510 and 39 Ceti, which have relatively short periods and normal abundance giants, appear to be consistent with this scenario. The last binary, HD 160538, a system with apparently near solar abundances, a white dwarf companion, and orbital characteristics similar to many barium stars, demonstrates that the existence of a white-dwarf companion is insufficient to produce a barium star. The paucity of systems with confirmed white-dwarf companions makes abundance analyses of HD 160538 and HD 165141 of great value in examining the role of metallicity in barium star formation.

  15. Chromospherically active stars. 11: Giant with compact hot companions and the barium star scenario

    NASA Technical Reports Server (NTRS)

    Fekel, Francis C.; Henry, Gregory W.; Busby, Michael R.; Eitter, Joseph J.

    1993-01-01

    We have determined spectroscopic orbits for three chromsopherically active giants that have hot compact companions. They are HD 160538 (KO III + wd, P = 904 days), HD 165141 (G8 III + wd, P approximately 5200 days), and HD 185510 (KO III + sdB, P = 20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion of HD 165141 has a temperature of about 35,000 K. Spectral types and rotational velocities have been determined for the three giants and distances have been estimated. These three systems and 39 Ceti are compared with the barium star mass-transfer scenario. The long-period mild barium giant HD 165141 as well as HD 185510 and 39 Ceti, which have relatively short periods and normal abundance giants, appear to be consistent with this scenario. The last binary, HD 160538, a system with apparently near solar abundances, a white dwarf companion, and orbital characteristics similar to many barium stars, demonstrates that the existence of a white dwarf companion is insufficient to produce a barium star. The paucity of systems with confirmed white dwarf companions makes abundance analyses of HD 160538 and HD 165141 of great value in examining the role of metallicity in barium star formation.

  16. Simple model for active nematics: quasi-long-range order and giant fluctuations.

    PubMed

    Chaté, Hugues; Ginelli, Francesco; Montagne, Raúl

    2006-05-12

    We propose a simple microscopic model for active nematic particles similar in spirit to the Vicsek model for self-propelled polar particles. In two dimensions, we show that this model exhibits a Kosterlitz-Thouless-like transition to quasi-long-range orientational order and that in this nonequilibrium context, the ordered phase is characterized by giant density fluctuations, in agreement with the predictions of Ramaswamy et al.

  17. An extensive pockmark field on the upper Atlantic margin of Southeast Brazil: spatial analysis and its relationship with salt diapirism.

    PubMed

    de Mahiques, Michel Michaelovitch; Schattner, Uri; Lazar, Michael; Sumida, Paulo Yukio Gomes; Souza, Luiz Antonio Pereira de

    2017-02-01

    We present new evidence for the existence of a large pockmark field on the continental slope of the Santos Basin, offshore southeast Brazil. A recent high-resolution multibeam bathymetric survey revealed 984 pockmarks across a smooth seabed at water depths of 300-700 m. Four patterns of pockmark arrays were identified in the data: linear, network, concentric, and radial. Interpretation of Two-dimensional multi-channel seismic reflection profiles that crosscut the surveyed area shows numerous salt diapirs in various stages of development (e.g. salt domes, walls, and anticlines). Some diapirs were exposed on the seafloor, whereas the tops of others (diapir heads) were situated several hundreds of meters below the surface. Extensional faults typically cap these diapirs and reach shallow depths beneath the seafloor. Our analysis suggests that these pockmark patterns are linked to stages in the development of underlying diapirs and their related faults. The latter may extend above salt walls, take the form of polygonal extensional faults along higher-level salt anticlines, or concentric faults above diapir heads that reach close to the seafloor. Seismic data also revealed buried pockmark fields that had repeatedly developed since the Middle Miocene. The close spatio-temporal connection between pockmark and diapir distribution identified here suggests that the pockmark field extends further across the Campos and Espírito Santo Basins, offshore Brazil. Spatial overlap between the pockmark field topping a large diapir field and a proliferous hydrocarbon basin is believed to have facilitated the escape of fluid/gas from the subsurface to the water column, which was enhanced by halokinesis. This provides a possible control on fossil gas contribution to the marine system over geological time.

  18. Unit pockmarks associated with Lophelia coral reefs off mid-Norway: more evidence of control by `fertilizing' bottom currents

    NASA Astrophysics Data System (ADS)

    Hovland, Martin; Jensen, Sigmund; Indreiten, Tore

    2012-12-01

    High-resolution topographic mapping of Norwegian deep-water Lophelia coral reefs and their immediate surrounding seafloor has disclosed striking associations with small (<5 m diameter) `unit' pockmarks. A total of four study areas with Lophelia reefs and unit pockmarks are here described and discussed. At the large Fauna reef, which spans 500 m in length and 100 m in width (25 m in height), there is a field of 184 unit pockmarks occurring on its suspected upstream side. Three other, intermediate-sized Morvin reefs are associated with small fields of unit pockmarks situated upstream of live Lophelia colonies. For two of the latter locations, published data exist for geochemical and microbial analyses of sediment and water samples. Results indicate that these unit pockmarks are sources of light dissolved hydrocarbons for the local water mass, together with nutrient-rich pore waters. It is suggested that the `fertilized' seawater flows with the prevailing bottom current and feeds directly into the live portion of the Lophelia reefs. With an estimated growth rate of ~1 cm per year for the Morvin Lophelia corals, it would take between 1,000 and 2,000 years for the reefs to colonize the closest unit pockmarks, currently occurring 10-20 m from their leading (live) edges.

  19. Giant Volume Change of Active Gels under Continuous Flow

    DTIC Science & Technology

    2014-04-21

    communication17 of BZ droplets and chemical self-organiza- tion,18 the properties and potential of self-oscillating gels in a microfluidic system have yet to be...active gels driven by the Belousov−Zhabotinsky reaction. These results demon- strate that microfluidics offers a useful and facile experimental...soft materials and microfluidic systems. ■ INTRODUCTION This paper reports the use of a continuous reactant flow in a microfluidic system to achieve

  20. Expelled subsalt fluids form a pockmark field in the eastern Red Sea

    NASA Astrophysics Data System (ADS)

    Feldens, P.; Schmidt, M.; Mücke, I.; Augustin, N.; Al-Farawati, R.; Orif, M.; Faber, E.

    2016-10-01

    This study aimed to constrain the source area of fluids responsible for the formation of a pockmark field in the eastern Red Sea. The newly discovered field extends over an area of at least 1,000 km2 at a water depth of ~400 m. The pockmarks have modal diameters of 140-150 m and are either randomly distributed on the seafloor or aligned within valleys approximately 25 m deep and several kilometres in length. Seismic data show that chimneys and/or regions of acoustic turbidity prevail beneath the pockmark field down to the top of Miocene evaporites, which are widespread in the Red Sea. Four gravity cores were taken from the pockmark field. For most of the cores, geochemical analyses show that porewater has a higher Cl concentration than the local seawater and increased Cl/Br ratios, which indicate an origin from evaporites. The adsorbed hydrocarbons are of thermal origin, with C1/(C2+C3) ratios between 4 and 23 and stable carbon isotope data for methane varying from δ13C of -34 to -36.4‰ with respect to Vienna Pee Dee Belemnite. On the basis of the calculated maturity of the source rock of 1.2-1.4 Ro, local thermal gradients and sedimentation rates, its deeper depth boundary is approximated at 2,000 to 2,200 m. The results indicate that the adsorbed hydrocarbons sampled at the seafloor had to pass through an evaporite sequence of potentially several hundred metres to a few km in thickness. The most likely explanation for the increased permeability of the evaporite sequence is brittle deformation triggered by extensive local tectonic movements and supported by high fluid overpressure within the evaporite sequence.

  1. Magnetic Field Structure and Activity of the He-burning Giant 37 Comae

    NASA Astrophysics Data System (ADS)

    Tsvetkova, S.; Petit, P.; Konstantinova-Antova, R.; Aurière, M.; Wade, G. A.; Charbonnel, C.; Drake, N. A.

    2014-08-01

    We present the first magnetic map of the late-type giant 37 Com. The Least Squares Deconvolution (LSD) method and Zeeman Doppler Imaging (ZDI) inversion technique were applied. The chromospheric activity indicators Hα, S-index, Ca ii IRT and the radial velocity were also measured. The evolutionary status of the star has been studied on the basis of state-of-the-art stellar evolutionary models and chemical abundance analysis. 37 Com appears to be in the core Helium-burning phase.

  2. Pockmark development in the Petrel Sub-basin, Timor Sea, Northern Australia: Seabed habitat mapping in support of CO2 storage assessments

    NASA Astrophysics Data System (ADS)

    Nicholas, W. A.; Nichol, S. L.; Howard, F. J. F.; Picard, K.; Dulfer, H.; Radke, L. C.; Carroll, A. G.; Tran, M.; Siwabessy, P. J. W.

    2014-07-01

    The extent to which fluids may leak from sedimentary basins to the seabed is a critical issue for assessing the potential of a basin for carbon capture and storage. The Petrel Sub-basin, located beneath central and eastern Joseph Bonaparte Gulf in tropical northern Australia, was identified as potentially suitable for the geological storage of CO2 because of its geological characteristics and proximity to offshore gas and petroleum resources. In May 2012, a multidisciplinary marine survey (SOL5463) was undertaken to collect data in two targeted areas of the Petrel Sub-basin to facilitate an assessment of its CO2 storage potential. This paper focuses on Area 1 of that survey, a 471 km2 area of sediment-starved shelf (water depths of 78 to 102 m), characterised by low-gradient plains, low-lying ridges, palaeo-channels and shallow pockmarks. Three pockmark types are recognised: small shallow unit pockmarks 10-20 m in diameter (generally <1 m, rarely to 2 m deep), composite pockmarks of 150-300 m diameter formed from the co-location of several cross-cutting pockmarks forming a broad shallow depression (<1 m deep), and pockmark clusters comprised of shallow unit pockmarks co-located side by side (150-300 m width overall, <1 m deep). Pockmark distribution is non-random, focused within and adjacent to palaeo-channels, with pockmark clusters also located adjacent to ridges. Pockmark formation is constrained by AMS 14C dating of in situ mangrove deposits and shells to have begun after 15.5 cal ka BP when a rapid marine transgression of Bonaparte Shelf associated with meltwater pulse 1A drowned coastal mangrove environments. Pockmark development is likely an ongoing process driven by fluid seepage at the seabed, and sourced from CO2 produced in the shallow sub-surface (<2 m) sediment. No evidence for direct connection to deeper features was observed.

  3. Differentiation of trophoblast giant cells and their metabolic functions are dependent on peroxisome proliferator-activated receptor beta/delta.

    PubMed

    Nadra, Karim; Anghel, Silvia I; Joye, Elisabeth; Tan, Nguan Soon; Basu-Modak, Sharmila; Trono, Didier; Wahli, Walter; Desvergne, Béatrice

    2006-04-01

    Mutation of the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) severely affects placenta development, leading to embryonic death at embryonic day 9.5 (E9.5) to E10.5 of most, but not all, PPARbeta/delta-null mutant embryos. While very little is known at present about the pathway governed by PPARbeta/delta in the developing placenta, this paper demonstrates that the main alteration of the placenta of PPARbeta/delta-null embryos is found in the giant cell layer. PPARbeta/delta activity is in fact essential for the differentiation of the Rcho-1 cells in giant cells, as shown by the severe inhibition of differentiation once PPARbeta/delta is silenced. Conversely, exposure of Rcho-1 cells to a PPARbeta/delta agonist triggers a massive differentiation via increased expression of 3-phosphoinositide-dependent kinase 1 and integrin-linked kinase and subsequent phosphorylation of Akt. The links between PPARbeta/delta activity in giant cells and its role on Akt activity are further strengthened by the remarkable pattern of phospho-Akt expression in vivo at E9.5, specifically in the nucleus of the giant cells. In addition to this phosphatidylinositol 3-kinase/Akt main pathway, PPARbeta/delta also induced giant cell differentiation via increased expression of I-mfa, an inhibitor of Mash-2 activity. Finally, giant cell differentiation at E9.5 is accompanied by a PPARbeta/delta-dependent accumulation of lipid droplets and an increased expression of the adipose differentiation-related protein (also called adipophilin), which may participate to lipid metabolism and/or steroidogenesis. Altogether, this important role of PPARbeta/delta in placenta development and giant cell differentiation should be considered when contemplating the potency of PPARbeta/delta agonist as therapeutic agents of broad application.

  4. Are seafloor pockmarks on the Chatham Rise, New Zealand, linked to CO2 hydrates? Gas hydrate stability considerations.

    NASA Astrophysics Data System (ADS)

    Pecher, I. A.; Davy, B. W.; Rose, P. S.; Coffin, R. B.

    2015-12-01

    Vast areas of the Chatham Rise east of New Zealand are covered by seafloor pockmarks. Pockmark occurrence appears to be bathymetrically controlled with a band of smaller pockmarks covering areas between 500 and 700 m and large seafloor depressions beneath 800 m water depth. The current depth of the top of methane gas hydrate stability in the ocean is about 500 m and thus, we had proposed that pockmark formation may be linked to methane gas hydrate dissociation during sealevel lowering. However, while seismic profiles show strong indications of fluid flow, geochemical analyses of piston cores do not show any evidence for current or past methane flux. The discovery of Dawsonite, indicative of significant CO2 flux, in a recent petroleum exploration well, together with other circumstantial evidence, has led us to propose that instead of methane hydrate, CO2 hydrate may be linked to pockmark formation. We here present results from CO2 hydrate stability calculations. Assuming water temperature profiles remain unchanged, we predict the upper limit of pockmark occurrence to coincide with the top of CO2 gas hydrate stability during glacial-stage sealevel lowstands. CO2 hydrates may therefore have dissociated during sealevel lowering leading to gas escape and pockmark formation. In contrast to our previous model linking methane hydrate dissociation to pockmark formation, gas hydrates would dissociate beneath a shallow base of CO2 hydrate stability, rather than on the seafloor following upward "grazing" of the top of methane hydrate stability. Intriguingly, at the water depths of the larger seafloor depressions, the base of gas hydrate stability delineates the phase boundary between CO2 hydrates and super-saturated CO2. We caution that because of the high solubility of CO2, dissociation from hydrate to free gas or super-saturated CO2 would imply high concentrations of CO2 and speculate that pockmark formation may be linked to CO2 hydrate dissolution rather than dissociation

  5. Gas hydrates and fluid venting in ultradeep large scale pockmarks at the southwest african margin off Congo

    NASA Astrophysics Data System (ADS)

    Spiess, V.; Kasten, S.; Schneider, R.; Zuehlsdorff, L.; Bohrmann, G.; Sahling, H.; Breitzke, M.; Bialas, J.; Ivanov, M.; Meteor Shipboard Scientific Party, M56.

    2003-04-01

    near feeder channels, which originate from shallow gas reservoirs at some hundred meters sub-bottom depth. The pockmark structures are furthermore associated with anomalies in temperature gradient. Sea floor sampling revealed in most cases several indicators of an active vent system as shallow, layered gas hydrates, carbonate precipitates and typical life forms.

  6. FUSE Cycle 3 Program CO22: Chromospheric Activity in Population II Giants

    NASA Technical Reports Server (NTRS)

    Harper, Graham M.

    2004-01-01

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

  7. Morphosedimentary expression of the Giant Pock Mark structure known as the "Gran Burato" (Transitional Zone, Galicia continental margin)

    NASA Astrophysics Data System (ADS)

    Lopez, Angel Enrique; Rubio, Belén; Rey, Daniel; Mohamed, Kais; Alvarez, Paula; Plaza-Morlote, Maider; Bernabeu, Ana; Druet, Maria; Martins, Virginia

    2016-04-01

    This paper presents the characterization of the sedimentary environment and other sedimentological features of the Transitional Zone of the Galicia continental margin, in the vicinity of the giant pock -mark structure known as the Gran Burato. The area is characterized by marginal platforms and a horst-graben system controlled by NW-SE oriented normal faults. In this zone, three giant pockmark structures, one of them known as the Gran Burato, were reported as associated to large-scale fluid escapes. The study area is located on the Transitional Zone (TZ) of the Galicia passive continental margin, which extends from Cape Finisterre (43o N) in the North to around 40oN in the South. This margin shows a complex structural configuration, which is reflected in the seabed, owing to tectonic movements from Mesozoic rifting phases and Eocene compression (Pyrennean Orogeny). Sedimentological, geochemical and physical properties analysis and 14C AMS-dating of a 4 m piston core extracted in the vicinity of the Gran Burato complemented by multibeam and TOPAS surveys allowed characterizing of the sedimentary environment in the study area. The interpretation of these data showed that the sedimentary and tectonic evolution of the area controlled by the activity of fluid dynamics.

  8. Benthic Community Composition and Seabed Characteristics of a Chukchi Sea Pockmark

    NASA Astrophysics Data System (ADS)

    MacDonald, I. R.; Bluhm, B.; Iken, K.; Gagaev, S.; Robinson, S.

    2005-12-01

    Several dozen seafloor features were mapped by Larry Mayer and his colleagues using swath bathymetry during a 2003 cruise with the USCGC HEALY near the eastern edge of the Chukchi Plateau (Chukchi Sea 76.6N, 163.9W). These were sub-circular depressions ranging from approximately 250 to over 1000m in width, with depths of up to 50m below the surrounding seabed, and situated in water depths from 500 to 950m. The origin of these features was undetermined, but one possibility was that they were pockmarks formed as a result of gas or fluid expulsion processes. We report here on benthic sampling undertaken at one of these pockmarks on 18 July 2005, also from USCGC HEALY. This elongated feature had maximum water depth of approximately 940m, was 1200m in maximum width, and was depressed approximately 40m below the surrounding seabed. The ocean in the vicinity of the pockmark was heavily ice-covered, which tightly restricted the ship's mobility during sampling operations. We used an ROV to collect and photograph the benthic epifauna during a 6h transit that crossed from the outside of the pockmark to near the center over a distance of 900m. We used a down-looking digital camera to collect over 800 pictures of the benthos at altitudes of 2 to 3m above the seabed. We also collected three cores with a 25x25cm box corer. Our investigations did not provide any direct evidence for gas or fluid flux through the seabed of this feature. Neither did we see any secondary indications of methane flux such as authigenic carbonates or bacterial mats. The abundance and diversity of benthic epifauna at this station was the highest among 8 stations sampled using similar methods during a 30 day cruise. The ROV observed brittle stars, various types of anemones, shrimps, eel pouts, stalked crinoids, benthic ctenophore (likely new species), burrows and mounts, gooseneck barnacles, mysids. Holothurians (c.f. Peneagone sp.) were the single most abundant group and were often photographed in

  9. Near Infrared Activity Close to the Crab Pulsar Correlated with Giant Gamma-ray Flares

    NASA Technical Reports Server (NTRS)

    Rudy, Alexander R.; Max, Claire E.; Weisskopf, Martin C.

    2014-01-01

    We describe activity observed in the near-infrared correlated with a giant gamma-ray flare in the Crab Pulsar. The Crab Pulsar has been observed by the Fermi and AGILE satellites to flare for a period of 3 to 7 days, once every 1-1.5 years, increasing in brightness by a factor of 3-10 between 100MeV and 1GeV. We used Keck NIRC2 laser guide star adaptive optics imaging to observe the Crab Pulsar and environs before and during the March 2013 flare. We discuss the evidence for the knot as the location of the flares, and the theoretical implications of these observations. Ongoing target-of-opportunity programs hope to confirm this correlation for future flares.

  10. On Stellar Activity Enhancement Due to Interactions with Extrasolar Giant Planets.

    PubMed

    Cuntz; Saar; Musielak

    2000-04-20

    We present a first attempt to identify and quantify possible interactions between recently discovered extrasolar giant planets (and brown dwarfs) and their host stars, resulting in activity enhancement in the stellar outer atmospheres. Many extrasolar planets have masses comparable to or larger than Jupiter and are within a distance of 0.5 AU, suggesting the possibility of their significant influence on stellar winds, coronae, and even chromospheres. Beyond the well-known rotational synchronization, the interactions include tidal effects (in which enhanced flows and turbulence in the tidal bulge lead to increased magnetoacoustic heating and dynamo action) and direct magnetic interaction between the stellar and planetary magnetic fields. We discuss relevant parameters for selected systems and give preliminary estimates of the relative interaction strengths.

  11. Facilitation of polymer looping and giant polymer diffusivity in crowded solutions of active particles

    NASA Astrophysics Data System (ADS)

    Shin, Jaeoh; Cherstvy, Andrey G.; Kim, Won Kyu; Metzler, Ralf

    2015-11-01

    We study the dynamics of polymer chains in a bath of self-propelled particles (SPP) by extensive Langevin dynamics simulations in a two-dimensional model system. Specifically, we analyse the polymer looping properties versus the SPP activity and investigate how the presence of the active particles alters the chain conformational statistics. We find that SPPs tend to extend flexible polymer chains, while they rather compactify stiffer semiflexible polymers, in agreement with previous results. Here we show that higher activities of SPPs yield a higher effective temperature of the bath and thus facilitate the looping kinetics of a passive polymer chain. We explicitly compute the looping probability and looping time in a wide range of the model parameters. We also analyse the motion of a monomeric tracer particle and the polymer’s centre of mass in the presence of the active particles in terms of the time averaged mean squared displacement, revealing a giant diffusivity enhancement for the polymer chain via SPP pooling. Our results are applicable to rationalising the dimensions and looping kinetics of biopolymers at constantly fluctuating and often actively driven conditions inside biological cells or in suspensions of active colloidal particles or bacteria cells.

  12. The hyperpolarization-activated non-specific cation current (In ) adjusts the membrane properties, excitability, and activity pattern of the giant cells in the rat dorsal cochlear nucleus.

    PubMed

    Rusznák, Zoltán; Pál, Balázs; Kőszeghy, Aron; Fu, Yuhong; Szücs, Géza; Paxinos, George

    2013-03-01

    Giant cells of the cochlear nucleus are thought to integrate multimodal sensory inputs and participate in monaural sound source localization. Our aim was to explore the significance of a hyperpolarization-activated current in determining the activity of giant neurones in slices prepared from 10 to 14-day-old rats. When subjected to hyperpolarizing stimuli, giant cells produced a 4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyridinium chloride (ZD7288)-sensitive inward current with a reversal potential and half-activation voltage of -36 and -88 mV, respectively. Consequently, the current was identified as the hyperpolarization-activated non-specific cationic current (Ih ). At the resting membrane potential, 3.5% of the maximum Ih conductance was available. Immunohistochemistry experiments suggested that hyperpolarization-activated, cyclic nucleotide-gated, cation non-selective (HCN)1, HCN2, and HCN4 subunits contribute to the assembly of the functional channels. Inhibition of Ih hyperpolarized the membrane by 6 mV and impeded spontaneous firing. The frequencies of spontaneous inhibitory and excitatory postsynaptic currents reaching the giant cell bodies were reduced but no significant change was observed when evoked postsynaptic currents were recorded. Giant cells are affected by biphasic postsynaptic currents consisting of an excitatory and a subsequent inhibitory component. Inhibition of Ih reduced the frequency of these biphasic events by 65% and increased the decay time constants of the inhibitory component. We conclude that Ih adjusts the resting membrane potential, contributes to spontaneous action potential firing, and may participate in the dendritic integration of the synaptic inputs of the giant neurones. Because its amplitude was higher in young than in adult rats, Ih of the giant cells may be especially important during the postnatal maturation of the auditory system.

  13. Mitotically active proliferative nodule arising in a giant congenital melanocytic nevus: a diagnostic pitfall.

    PubMed

    Nguyen, Thuy L T; Theos, Amy; Kelly, David R; Busam, Klaus; Andea, Aleodor A

    2013-02-01

    Proliferative (cellular) nodules (PN) which mimic malignant melanoma clinically and histologically are described in congenital melanocytic nevi (CMN) and may pose significant diagnostic challenges. We report the case of a 10-day-old male with a giant congenital nevus involving the neck, upper chest, back, and left shoulder containing several nodular lesions, some crusted. Biopsy of a nodule revealed densely packed nevus cells with hyperchromatic round to oval and occasionally irregularly shaped nuclei. There was no necrosis or pushing border, and the nodule blended with the adjacent nevus; however, the lesion demonstrated a significant number of mitoses (27 per mm2) and a 60% labeling index with Ki-67. Further analysis by fluorescence in situ hybridization (FISH) with a 4-color probe set targeting 6p25, 6q23, 11q13, and centromere 6 revealed increased chromosomal copy numbers of all 4 probes, which was interpreted as evidence of polyploidy. In addition, analysis of DNA copy number changes using a single nucleotide polymorphism microarray (Affymetrix, Santa Clara, CA) showed no chromosomal aberrations. The diagnosis of PN in a giant congenital nevus was eventually rendered. At 13-month follow-up, the nodules showed no evidence of growth. Our case illustrates that PNs in the neonatal period might demonstrate extreme mitotic activity. This feature is worrisome when encountered in melanocytic lesions; however, it should not trigger by itself a diagnosis of melanoma in the absence of other histologic criteria of malignancy. In addition, we document polyploidy by FISH in PN, which can potentially be misinterpreted as a FISH-positive result.

  14. Submarine Dissolution During the Late-Miocene Carbonate Crash and Subsequent Mega-Pockmark Formation on the Cocos Ridge

    NASA Astrophysics Data System (ADS)

    Kluesner, J.; Silver, E. A.; Bangs, N. L.; McIntosh, K. D.

    2014-12-01

    A large field (245km2) seabed mega-pockmarks (~1 km to 4 km in diameter) was recently imaged on the western edge of the Cocos Ridge near the Middle American Trench. The pockmarks are part of a vast mega-pockmark field (~10x150 km) and were imaged using high-resolution multibeam bathymetry and backscatter and 3D seismic reflection data. On the seafloor, multiple pockmarks exhibit a two-tiered geomorphology, some of which contain small high-backscatter mounds, possibly indicating recent seafloor seepage. 3D seismic data reveal that the two-tiered morphology is caused by collapse structures at depth with large pockmarks above the walls of the former. Observed collapse structures are characterized by steep walls that truncate surrounding strata, apparent normal "ring" faults, chaotic internal reflections interpreted as infill, and circular morphologies. Younger pockmarks located above the walls of the collapse structures are larger in diameter, have gently dipping walls that do not truncate surrounding strata, and typically show elliptical morphologies. Physical properties results at IODP Site U1414 that intersects the 3D seismic volume suggest that observed reverse polarity lens-shaped zones, which are truncated by the deeper collapse structures, represent anomalous regions of high porosity and low density. In addition, a rapid drop in Ca concentrations observed within this interval at Site U1414 suggests a relationship with possible carbonate dissolution. Correlation of the collapse structures stratigraphic timing with nanno-fossil data at Site U1414 suggests formation occurred ~8-10 Ma, approximately during the Late Miocene eastern Pacific carbonate crash. Based on 3D seismic analysis and recent drilling results, we propose a two-stage formation process that consists of initial collapse caused by carbonate dissolution during the late Miocene, followed by sustained fluid-flow along the walls of established collapse features, resulting in pockmark formation. This

  15. Synthesis of extremely large mesoporous activated carbon and its unique adsorption for giant molecules

    SciTech Connect

    Tamai, Hisashi; Kakii, Takuhiro; Hirota, Yoshifumi

    1996-02-01

    The steam invigoration of pitches (softening points 85 and 280{degrees}C) homogenized with 1-3 wt% of organo rare0earth metal complexes such as Ln(C{sub 5}H{sub 5}){sub 3} or Ln(acac) (Ln=Y, Yb) at 930{degrees}C provided activated carbons with an extremely high mesopore ration, >70%. The resulted activated carbon selectively adsorbs giant molecules such as Vitamin B{sub 12}, blue acid 90 dye, dextran, nystatin, and humic acid, reflecting their large mesopore volumes. To understand what kind of carbon skeleton in pitch is suited for generation of high mesopore ration, the steam invigoration of a series of condensed polynuclear aromatics (COPNA) resins prepared from naphthlene, anthracene, phenanthrene, pyrene, or perylene and p-xylene-{alpha},{alpha}{prime}-diol were conducted in the presence of rare-earth metal complexes. As a result, COPNA resins containing phenanthrene, perylene, and pyrene generated large mesopore volume. 35 refs., 16 figs., 11 tabs.

  16. Active Transport of Potassium by the Giant Neuron of the Aplysia Abdominal Ganglion

    PubMed Central

    Russell, J. M.; Brown, A. M.

    1972-01-01

    We measured the internal potassium activity, aiK, and membrane potential, Em, simultaneously in 111 R2 giant neurons of Aplysia californica. aiK was 165.3 ± 3.4 mM, Em was -47.8 ± 0.9 mv, and EK calculated using the Nernst equation was -76.9 ± 0.05 mv. Such values were maintained for as long as 6 hr of continuous recording in untreated cells, aiK fell exponentially after the following treatments: cooling to 0.5°–4°C, ouabain, zero external potassium, 2,4-dinitrophenol, and cyanide. The effects of cooling and zero potassium were reversible. Potassium permeability was calculated from net potassium flux using the constant field equation and ranged from 2.6 to 18.5 x 10-8 cm/sec. We conclude that potassium is actively transported into this neuron against a 30–40 mv electrochemical gradient. PMID:4644326

  17. Active Transport of Chloride by the Giant Neuron of the Aplysia Abdominal Ganglion

    PubMed Central

    Russell, J. M.; Brown, A. M.

    1972-01-01

    Internal chloride activity, aiCl, and membrane potential, Em, were measured simultaneously in 120 R2 giant neurons of Aplysia californica. aiCl was 37.0 ± 0.8 mM, Em was -49.3 ± 0.4 mv, and ECl calculated using the Nernst equation was -56.2 ± 0.5 mv. Such values were maintained for as long as 6 hr of continuous recording in untreated neurons. Cooling to 1°–4°C caused aiCl to increase at such a rate that 30–80 min after cooling began, ECl equalled Em. The two then remained equal for as long as 6 hr. Rewarming to 20°C caused aiCl to decline, and ECl became more negative than Em once again. Exposure to 100 mM K+-artificial seawater caused a rapid increase of aiCl. Upon return to control seawater, aiCl declined despite an unfavorable electrochemical gradient and returned to its control values. Therefore, we conclude that chloride is actively transported out of this neuron. The effects of ouabain and 2,4-dinitrophenol were consistent with a partial inhibitory effect. Chloride permeability calculated from net chloride flux using the constant field equation ranged from 4.0 to 36 x 10-8 cm/sec. PMID:4644325

  18. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Unruh, Y. C.; Koskinen, T. T.; Sanz-Forcada, J.

    2015-04-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - ɛ Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale the EUV regions of the solar spectrum based upon stellar X-ray emission. This new method produces an outcome in terms of the planet's neutral upper atmosphere very similar to that obtained using a detailed coronal model of the host star. Our results indicate that in planets subjected to radiation from active stars, the transition from Jeans escape to a regime of hydrodynamic escape at the top of the atmosphere occurs at larger orbital distances than for planets around low activity stars (such as the Sun).

  19. The age-mass relation for chromospherically active binaries. III. Lithium depletion in giant components

    NASA Astrophysics Data System (ADS)

    Barrado y Navascues, D.; de Castro, E.; Fernandez-Figueroa, M. J.; Cornide, M.; Garcia Lopez, R. J.

    1998-09-01

    We present a study of the lithium abundances of a sample of evolved components of Chromospherically Active Binary Systems. We show that a significant part of them have lithium excesses, independently of their mass and evolutionary stage. Therefore, it can be concluded that Li abundance does not depend on age for giant components of CABS. These overabundances appear to be closely related to the stellar rotation, and we interpret them as a consequence of the transfer of angular momentum from the orbit to the rotation as the stars evolve in and off the Main Sequence, in a similar way as it happens in the dwarf components of the same systems and in the Tidally Locked Binaries belonging to the Hyades and M67. Based on observations collected with the 2.2\\,m telescope of the German-Spanish Observatorio de Calar Alto (Almeria, Spain), and with the 2.56\\,m Nordic Optical Telescope in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof\\'\\i sica de Canarias (La Palma, Spain)

  20. Control of the active site structure of giant bilayer hemoglobin from the Annelid Eisenia foetida using hierarchic assemblies

    SciTech Connect

    Girasole, Marco; Arcovito, Alessandro; Marconi, Augusta; Davoli, Camilla; Congiu-Castellano, Agostina; Bellelli, Andrea; Amiconi, Gino

    2005-12-05

    The active site structure of the oxygenated derivative of the main subassemblies (whole protein, dodecamers, and trimers) of the giant haemoglobin from Eisenia foetida has been characterized by x-ray absorption near edge structure spectroscopy. The data revealed a remarkable effect of the hierarchic assemblies on the active site of the subunit. Specifically, the whole protein has the same site structure of the dodecamer, while a sharp conformational transition occurs when the dodecamer is disassembled into trimers (and monomers) revealing that constraints due to the protein matrix determine the active site geometry and, consequently, the protein function in these large complexes.

  1. Transcriptional activity of the giant barrel sponge, Xestospongia muta Holobiont: molecular evidence for metabolic interchange

    PubMed Central

    Fiore, Cara L.; Labrie, Micheline; Jarett, Jessica K.; Lesser, Michael P.

    2015-01-01

    Compared to our understanding of the taxonomic composition of the symbiotic microbes in marine sponges, the functional diversity of these symbionts is largely unknown. Furthermore, the application of genomic, transcriptomic, and proteomic techniques to functional questions on sponge host-symbiont interactions is in its infancy. In this study, we generated a transcriptome for the host and a metatranscriptome of its microbial symbionts for the giant barrel sponge, Xestospongia muta, from the Caribbean. In combination with a gene-specific approach, our goals were to (1) characterize genetic evidence for nitrogen cycling in X. muta, an important limiting nutrient on coral reefs (2) identify which prokaryotic symbiont lineages are metabolically active and, (3) characterize the metabolic potential of the prokaryotic community. Xestospongia muta expresses genes from multiple nitrogen transformation pathways that when combined with the abundance of this sponge, and previous data on dissolved inorganic nitrogen fluxes, shows that this sponge is an important contributor to nitrogen cycling biogeochemistry on coral reefs. Additionally, we observed significant differences in gene expression of the archaeal amoA gene, which is involved in ammonia oxidation, between coral reef locations consistent with differences in the fluxes of dissolved inorganic nitrogen previously reported. In regards to symbiont metabolic potential, the genes in the biosynthetic pathways of several amino acids were present in the prokaryotic metatranscriptome dataset but in the host-derived transcripts only the catabolic reactions for these amino acids were present. A similar pattern was observed for the B vitamins (riboflavin, biotin, thiamin, cobalamin). These results expand our understanding of biogeochemical cycling in sponges, and the metabolic interchange highlighted here advances the field of symbiont physiology by elucidating specific metabolic pathways where there is high potential for host

  2. Rising fecal glucocorticoid concentrations track reproductive activity in the female giant panda (Ailuropoda melanoleuca).

    PubMed

    Kersey, David C; Wildt, David E; Brown, Janine L; Snyder, Rebecca J; Huang, Yan; Monfort, Steven L

    2011-09-01

    To better understand the adaptive significance of adrenal glucocorticoid (GC) variation in the giant panda, we assessed patterns of fecal GC excretion over time as well as during estrus, parturient and non-parturient luteal phases, lactation and acyclicity in 17 adult females. Fecal estrogen and GC patterns were positively correlated (P<0.05) in four of five periestrual females (r = 0.57-0.92). Among all reproductive states, fecal GC was highest (P<0.05) during periestrus (non-parturient, 495.9 ± 100.7 ng/g [mean ± SE]; parturient, 654.1 ± 10 6.5 ng/g; P>0.05). Concentrations of GC metabolites were lower (P<0.05) during the later stage of the luteal phase in non-parturient (334.8 ± 24.8 ng/g) compared to parturient (470.4 ± 54.0 ng/g) females. Although fecal GC concentrations in cyclic, non-parturient females did not differ (P>0.05) across all seasons, there were seasonal variations (P<0.05) in females that were acyclic and non-lactational. However, the overall lack of difference (P>0.05) in GC values between reproductively cyclic and acyclic females did not support the hypothesis that ovarian acyclicity is due to increased adrenal activity (related or unrelated to physiological stress). Furthermore, GCs may play an important role in the normal endocrine milieu associated with sexual receptivity and late pregnancy. These data demonstrate that both reproductive status and seasonal factors are important modulators of adrenal function in this endangered species.

  3. EUV-driven ionospheres and electron transport on extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Koskinen, T. T.; Miller, S.; Sanz-Forcada, J.; Unruh, Y. C.; Yelle, R. V.

    2016-03-01

    The composition and structure of the upper atmospheres of extrasolar giant planets (EGPs) are affected by the high-energy spectrum of their host stars from soft X-rays to the extreme ultraviolet (EUV). This emission depends on the activity level of the star, which is primarily determined by its age. In this study, we focus upon EGPs orbiting K- and M-dwarf stars of different ages - ɛ Eridani, AD Leonis, AU Microscopii - and the Sun. X-ray and EUV (XUV) spectra for these stars are constructed using a coronal model. These spectra are used to drive both a thermospheric model and an ionospheric model, providing densities of neutral and ion species. Ionisation - as a result of stellar radiation deposition - is included through photo-ionisation and electron-impact processes. The former is calculated by solving the Lambert-Beer law, while the latter is calculated from a supra-thermal electron transport model. We find that EGP ionospheres at all orbital distances considered (0.1-1 AU) and around all stars selected are dominated by the long-lived H+ ion. In addition, planets with upper atmospheres where H2 is not substantially dissociated (at large orbital distances) have a layer in which H3+ is the major ion at the base of the ionosphere. For fast-rotating planets, densities of short-lived H3+ undergo significant diurnal variations, with the maximum value being driven by the stellar X-ray flux. In contrast, densities of longer-lived H+ show very little day/night variability and the magnitude is driven by the level of stellar EUV flux. The H3+ peak in EGPs with upper atmospheres where H2 is dissociated (orbiting close to their star) under strong stellar illumination is pushed to altitudes below the homopause, where this ion is likely to be destroyed through reactions with heavy species (e.g. hydrocarbons, water). The inclusion of secondary ionisation processes produces significantly enhanced ion and electron densities at altitudes below the main EUV ionisation peak, as

  4. Atmospheric circulation of brown dwarfs and directly imaged extrasolar giant planets with active clouds

    NASA Astrophysics Data System (ADS)

    Tan, Xianyu; Showman, Adam

    2016-10-01

    Observational evidence have suggested active meteorology in the atmospheres of brown dwarfs (BDs) and directly imaged extrasolar giant planets (EGPs). In particular, a number of surveys for brown dwarfs showed that near-IR brightness variability is common for L and T dwarfs. Directly imaged EGPs share similar observations, and can be viewed as low-gravity versions of BDs. Clouds are believed to play the major role in shaping the thermal structure, dynamics and near-IR flux of these atmospheres. So far, only a few studies have been devoted to atmospheric circulation and the implications for observations of BDs and directly EGPs, and yet no global model includes a self-consistent active cloud formation. Here we present preliminary results from the first global circulation model applied to BDs and directly imaged EGPs that can properly treat absorption and scattering of radiation by cloud particles. Our results suggest that horizontal temperature differences on isobars can reach up to a few hundred Kelvins, with typical horizontal length scale of the temperature and cloud patterns much smaller than the radius of the object. The combination of temperature anomaly and cloud pattern can result in moderate disk-integrated near-IR flux variability. Wind speeds can reach several hundred meters per second in cloud forming layers. Unlike Jupiter and Saturn, we do not observe stable zonal jet/banded patterns in our simulations. Instead, our simulated atmospheres are typically turbulent and dominated by transient vortices. The circulation is sensitive to the parameterized cloud microphysics. Under some parameter combinations, global-scale atmospheric waves can be triggered and maintained. These waves induce global-scale temperature anomalies and cloud patterns, causing large (up to several percent) disk-integrated near-IR flux variability. Our results demonstrate that the commonly observed near-IR brightness variability for BDs and directly imaged EGPs can be explained by the

  5. Pockmarks, fluid flow, and sediments outboard of the deformation front at the Cascadia Subduction Zone from analysis of multi-channel seismic and multi-beam sonar data

    NASA Astrophysics Data System (ADS)

    Gibson, J. C.; Carbotte, S. M.; Han, S.; Carton, H. D.; Canales, P.; Nedimovic, M. R.

    2013-12-01

    Evidence of active fluid flow and the nature of the sediment section near the Cascadia deformation front are explored using multi-channel (MCS) seismic and multi-beam sonar data collected in summer 2012 using the R/V Marcus G. Langseth during the Juan de Fuca Ridge to Trench Survey. The MCS data were collected along two full plate transects (the 'Oregon' and 'Washington' transects) and one trench parallel line using a 6600 cubic inch source, and an 8 km streamer with 636 channels (12.5 m spacing). The MCS data pre-stack processing sequence includes geometry definition, trace editing, F-K filter, and deconvolution. Velocity analysis is performed via semblance and constant velocity stacks in order to create a velocity model of the sediments and upper oceanic crust. The traces are then stacked, and post-stack time migrated. The sonar data were collected using the R/V Langseth's Kongsberg EM122 1°x1° multi-beam sonar with 288 beams and 432 total soundings across track. Using MB-system the sonar data are cleaned, and the bathymetry data are then gridded at 35 m, while the backscatter data are gridded at 15 m. From the high-resolution mapping data 48 pockmarks varying in diameter from 50 m - 1 km are identified within 60 km outboard of the deformation front. The surface expression of these large features in an area of heavy sedimentation is likely indicative of active fluid flow. In order to gain sub-seafloor perspective on these features the MCS data are draped below the bathymetry/backscatter grids using QPS Fledermaus. From this perspective, specific locations for detailed velocity and attribute analysis of the sediment section are chosen. Sediment velocity and attribute analysis also provide insight into apparent differences in the sediment section and décollement formation along the Oregon and Washington plate transects. While both lines intersect areas of dense pockmark concentration, the area around the Oregon transect has been shown to contain a continuous

  6. Magnetic fields in single late-type giants in the Solar vicinity: How common is magnetic activity on the giant branches?

    NASA Astrophysics Data System (ADS)

    Konstantinova-Antova, Renada; Aurière, Michel; Charbonnel, Corinne; Drake, Natalia; Wade, Gregg; Tsvetkova, Svetla; Petit, Pascal; Schröder, Klaus-Peter; Lèbre, Agnes

    2014-08-01

    We present our first results on a new sample containing all single G, K and M giants down to V = 4 mag in the Solar vicinity, suitable for spectropolarimetric (Stokes V) observations with Narval at TBL, France. For detection and measurement of the magnetic field (MF), the Least Squares Deconvolution (LSD) method was applied (Donati et al. 1997) that in the present case enables detection of large-scale MFs even weaker than the solar one (the typical precision of our longitudinal MF measurements is 0.1-0.2 G). The evolutionary status of the stars is determined on the basis of the evolutionary models with rotation (Lagarde et al. 2012; Charbonnel et al., in prep.) and fundamental parameters given by Massarotti et al. (1998). The stars appear to be in the mass range 1-4 M ⊙, situated at different evolutionary stages after the Main Sequence (MS), up to the Asymptotic Giant Branch (AGB). The sample contains 45 stars. Up to now, 29 stars are observed (that is about 64% of the sample), each observed at least twice. For 2 stars in the Hertzsprung gap, one is definitely Zeeman detected. Only 5 G and K giants, situated mainly at the base of the Red Giant Branch (RGB) and in the He-burning phase are detected. Surprisingly, a lot of stars ascending towards the RGB tip and in early AGB phase are detected (8 of 13 observed stars). For all Zeeman detected stars v sin i is redetermined and appears in the interval 2-3 km/s, but few giants with MF possess larger v sin i.

  7. Biological assessment of the effects of petroleum production activities, Naval Petroleum Reserves in California, on the endangered giant kangaroo rat, Dipodomys ingens

    SciTech Connect

    O'Farrell, T.P.; Kato, T.T.

    1987-09-01

    This Biological Assessment evaluates the potential adverse effects that production activities conducted on the Naval Petroleum Reserveys in California may have on the endangered giant kangaroo rat (Dipodomys ingens). DOE concluded that the direct, indirect, and cumulative effects of the proposed activities will not jeopardize the continued existence of the species because results of surveys indicated that giant kangaroo rat burrow systems and habitat was initiated; a habitat restoration program was developed and implemented; and administrative policies to reduce vehicle speeds, contain oil and waste water spills, restrict off-road vehicle travel, and to regulate public access, livestock grazing, and agricultural activities were maintained. 33 refs., 3 figs.

  8. Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

    PubMed

    Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

    2011-01-01

    The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

  9. Tsc2 null murine neuroepithelial cells are a model for human tuber giant cells, and show activation of an mTOR pathway.

    PubMed

    Onda, Hiroaki; Crino, Peter B; Zhang, Hongbing; Murphey, Ryan D; Rastelli, Luca; Gould Rothberg, Bonnie E; Kwiatkowski, David J

    2002-12-01

    Cortical tubers are developmental brain malformations in the tuberous sclerosis complex (TSC) that cause epilepsy and autism in TSC patients whose pathogenesis is uncertain. Tsc2 null murine neuroepithelial progenitor (NEP) cells display persistent growth when growth factors are withdrawn, express GFAP at high levels, and have reduced expression of a set of early neuronal lineage markers. Tsc2 null NEP cells exhibit aberrant differentiation into giant cells that express both beta III-tubulin and GFAP and that are morphologically similar to giant cells in human tubers. Tsc2 null giant cells and tuber giant cells have similar transcriptional profiles. Tsc2 null NEP cells express high levels of phosphorylated S6kinase, S6, Stat3, and 4E-BP-1, which is reversed by treatment with rapamycin, an inhibitor of mTOR. We conclude that giant cells in human tubers likely result from a complete loss of TSC2 expression and activation of an mTOR pathway during cortical development.

  10. Direct detection of a magnetic field at the surface of V390 Aurigae - an effectively single active giant

    NASA Astrophysics Data System (ADS)

    Konstantinova-Antova, R.; Aurière, M.; Iliev, I. Kh.; Cabanac, R.; Donati, J.-F.; Mouillet, D.; Petit, P.

    2008-03-01

    Aims:We have studied the active giant V390 Aur using spectropolarimetry to obtain direct and simultaneous measurements of the magnetic field and the activity indicators in order to infer the origin of the activity. Methods: We used the new spectropolarimeter NARVAL at the Bernard Lyot Telescope (Observatoire du Pic du Midi, France) to obtain a series of Stokes I and Stokes V profiles. Using the LSD technique we were able to detect the Zeeman signature of the magnetic field in each of our 5 observations and to measure its longitudinal component. Using the wide wavelength range of the spectra we could monitor the CaII K&H and IR triplet, as well as the Hα lines which are activity indicators. The Stokes I LSD profiles enabled us to detect and measure the profiles of two weak stellar companions. Results: From five observations obtained from November 2006 to March 2007, we deduce that the magnetic field has a complex structure which evolves with time and is reminiscent of a dynamo-induced magnetic field. The activity indicators also present day to day variations, but their behaviour does not completely follow the magnetic field variations, because their longitudinal component can cancel the contribution of complex magnetic features. There is a significant difference between the magnetic field observed on November 27, 2006 and on March 15, 2007, at the same rotational phase, but with an interval of 10 rotations. The behaviour of the activity indicators together with the measured enhanced magnetic field on March 15, 2007 support the idea of a change in the field topology. Analysis (RV and EW) of the absorption components of the Stokes I LSD profile shows that the secondary of the visual wide orbit binary ADS 3812 is itself a spectroscopic binary, and suggests that the synchronization effect does not play role for V390 Aur (the primary), and that the giant should be considered as effectively single with regard to its fast rotation and activity. Based on data obtained

  11. Transients in global Ca2+ concentration induced by electrical activity in a giant nerve terminal

    PubMed Central

    Neher, Erwin; Taschenberger, Holger

    2013-01-01

    Giant nerve terminals offer a unique opportunity to learn about dynamic changes in intracellular global Ca2+ concentration ([Ca2+]i) because this quantity can be measured precisely with indicator dyes and the composition of the intra-terminal ionic milieu can be controlled. We review here recent literature on [Ca2+]i signalling in the calyx of Held and discuss what these measurements can tell us about endogenous Ca2+ buffers and Ca2+ extrusion mechanisms. We conclude that in spite of the favourable experimental conditions, some unresolved questions still remain regarding absolute values for the Ca2+-binding ratio, the affinity of the basic fixed buffer and the Ca2+ affinities of the major endogenous Ca2+ binding proteins. Uncertainties about some of these presynaptic properties, including the roles of Mg2+ and ATP (as a Mg2+ buffer), however, extend to the point that mechanisms controlling the decay of [Ca2+]i signals in unperturbed terminals may have to be reconsidered. PMID:23529127

  12. Spatial and Temporal Activity Patterns of the Free-Living Giant Mole-Rat (Fukomys mechowii), the Largest Social Bathyergid

    PubMed Central

    Lövy, Matěj; Šklíba, Jan; Šumbera, Radim

    2013-01-01

    Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia), knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest) 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels). Our results suggest that the breeding individuals (at least males) contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions. PMID:23383166

  13. Kinetics of activation of the sodium conductance in the squid giant axon.

    PubMed Central

    Keynes, R D; Kimura, J E

    1983-01-01

    The time course of the rise in sodium conductance during positive voltage-clamp pulses was measured in squid giant axons perfused with CsF and immersed in low-sodium solutions. The initial transients were eliminated by subtraction of records made after blocking the sodium channels with tetrodotoxin. The value of tau m as defined by Hodgkin & Huxley (1952) passed through a well defined maximum at a membrane potential of about -35 mV. On fitting the initial inflexion in the rise of INa to the expression mXh instead of m3h, the value of X was found to vary from axon to axon between 2.9 and 4.4, with an average of 3.5. For any given axon, X did not vary significantly with pulse potential. Measurements of tau m were made on approaching each value of the membrane potential both from the negative and from the positive side. The cube law kinetics of the Hodgkin-Huxley equations were closely obeyed. Application of a negative prepulse to -180 mV delayed the rise of conductance by 20 musec at 7 degrees C without obviously changing tau m. Comparisons of the voltage dependence of tau m with that of the time constant tau 1 of the fast relaxation of the asymmetry current measured in the same axon, showed that tau 1 was smaller than tau m except at positive potentials, was less steeply voltage-dependent, and reached its maximum at a more positive potential. PMID:6308231

  14. STRONG VARIABLE ULTRAVIOLET EMISSION FROM Y GEM: ACCRETION ACTIVITY IN AN ASYMPTOTIC GIANT BRANCH STAR WITH A BINARY COMPANION?

    SciTech Connect

    Sahai, Raghvendra; Neill, James D.; Gil de Paz, Armando; Sanchez Contreras, Carmen

    2011-10-20

    Binarity is believed to dramatically affect the history and geometry of mass loss in asymptotic giant branch (AGB) and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars using the Galaxy Evolution Explorer archive, we have discovered a late-M star, Y Gem, to be a source of strong and variable UV emission. Y Gem is a prime example of the success of our technique of UV imaging of AGB stars in order to search for binary companions. Y Gem's large and variable UV flux makes it one of the most prominent examples of a late-AGB star with a mass accreting binary companion. The UV emission is most likely due to emission associated with accretion activity and a disk around a main-sequence companion star. The physical mechanism generating the UV emission is extremely energetic, with an integrated luminosity of a few x L{sub sun} at its peak. We also find weak CO J = 2-1 emission from Y Gem with a very narrow line profile (FWHM of 3.4 km s{sup -1}). Such a narrow line is unlikely to arise in an outflow and is consistent with emission from an orbiting, molecular reservoir of radius 300 AU. Y Gem may be the progenitor of the class of post-AGB stars which are binaries and possess disks but no outflows.

  15. Endopolyploidy in irradiated p53-deficient tumour cell lines: Persistence of cell division activity in giant cells expressing Aurora B- kinase

    PubMed Central

    Erenpreisa, Jekaterina; Ivanov, Andrei; Wheatley, Sally P; Kosmacek, Elizabeth A; Ianzini, Fiorenza; Anisimov, Alim P; Mackey, Michael; Davis, Paul J; Plakhins, Grigorijs; Illidge, Timothy M

    2008-01-01

    Recent findings including computerized live imaging suggest that polyploidy cells transiently emerging after severe genotoxic stress (and named ‘endopolyploid cells’) may have a role in tumour regrowth after anti-cancer treatment. Until now, mostly the factors enabling metaphase were studied in them. Here we investigate the mitotic activities and the role of Aurora B, in view of potential de-polyploidisation of these cells, because Aurora B- kinase is responsible for coordination and completion of mitosis. We observed that endopolyploid giant cells are formed in irradiated p53 tumours in several ways: (1) by division/fusion of daughter cells creating early multi-nucleated cells; (2) by asynchronous division/fusion of sub-nuclei of these multinucleated cells; (3) by a series of polyploidising mitoses reverting replicative interphase from aborted metaphase and forming giant cells with a single nucleus; (4) by micronucleation of arrested metaphases enclosing genome fragments; or (5) by incomplete division in the multipolar mitoses forming late multi-nucleated giant cells. We also observed that these activities are able to release para-diploid cells, although they do so infrequently. Although after a substantial delay, apoptosis typically occurs in these cells, we also found that roughly 2% of endopolyploid cells evade apoptosis and senescence arrest and continue mitotic activities. In this article we describe that catalytically active aurora B-kinase is expressed in the nuclei of many interphase endopolyploid cells, as well as being present at the centromeres, mitotic spindle and cleavage furrow during their mitotic efforts. The totally micronucleated giant cells (containing subgenomic fragments in multiple micronuclei) represented the only minor fraction, which failed to undergo mitosis and Aurora B was absent from it. These observations suggest that most endopolyploid tumour cells are not reproductively inert and that aurora B may contribute to the establishment

  16. Effects of ocean acidification on the photosynthetic performance, carbonic anhydrase activity and growth of the giant kelp Macrocystis pyrifera.

    PubMed

    Fernández, Pamela A; Roleda, Michael Y; Hurd, Catriona L

    2015-06-01

    Under ocean acidification (OA), the 200 % increase in CO2(aq) and the reduction of pH by 0.3-0.4 units are predicted to affect the carbon physiology and growth of macroalgae. Here we examined how the physiology of the giant kelp Macrocystis pyrifera is affected by elevated pCO2/low pH. Growth and photosynthetic rates, external and internal carbonic anhydrase (CA) activity, HCO3 (-) versus CO2 use were determined over a 7-day incubation at ambient pCO2 400 µatm/pH 8.00 and a future OA treatment of pCO2 1200 µatm/pH 7.59. Neither the photosynthetic nor growth rates were changed by elevated CO2 supply in the OA treatment. These results were explained by the greater use of HCO3 (-) compared to CO2 as an inorganic carbon (Ci) source to support photosynthesis. Macrocystis is a mixed HCO3 (-) and CO2 user that exhibits two effective mechanisms for HCO3 (-) utilization; as predicted for species that possess carbon-concentrating mechanisms (CCMs), photosynthesis was not substantially affected by elevated pCO2. The internal CA activity was also unaffected by OA, and it remained high and active throughout the experiment; this suggests that HCO3 (-) uptake via an anion exchange protein was not affected by OA. Our results suggest that photosynthetic Ci uptake and growth of Macrocystis will not be affected by elevated pCO2/low pH predicted for the future, but the combined effects with other environmental factors like temperature and nutrient availability could change the physiological response of Macrocystis to OA. Therefore, further studies will be important to elucidate how this species might respond to the global environmental change predicted for the ocean.

  17. Effect of steam activation of biochar produced from a giant Miscanthus on copper sorption and toxicity.

    PubMed

    Shim, Taeyong; Yoo, Jisu; Ryu, Changkook; Park, Yong-Kwon; Jung, Jinho

    2015-12-01

    This study aims to evaluate the physiochemical properties, sorption characteristics, and toxicity effects of biochar (BC) produced from Miscanthus sacchariflorus via slow pyrolysis at 500°C and its steam activation product (ABC). Although BC has a much lower surface area than ABC (181 and 322m(2)g(-1), respectively), the Cu sorption capacities of BC and ABC are not significantly different (p>0.05). A two-compartment model successfully explains the sorption of BC and ABC as being dominated by fast and slow sorption processes, respectively. In addition, both BC and ABC efficiently eliminate the toxicity of Cu towards Daphnia magna. However, ABC itself induced acute toxicity to D. magna, which is possibly due to increased aromaticity upon steam activation. These findings suggest that activation of BC produced from M. sacchariflorus at a pyrolytic temperature of 500°C may not be appropriate in terms of Cu sorption and toxicity reduction.

  18. Giant stellar arcs in the Large Magellanic Cloud: a possible link with past activity of the Milky Way nucleus

    NASA Astrophysics Data System (ADS)

    Efremov, Yuri N.

    2013-02-01

    The origin of the giant stellar arcs in the Large Magellanic Cloud (LMC) remains a controversial issue, one that has been discussed since 1966. No other star/cluster arc is so perfect a segment of a circle; moreover, there is another similar arc nearby. Many hypotheses were advanced to explain these arcs and all but one of these was disproved. It was proposed in 2004 that the origin of these arcs was a bow shock from the jet that is intermittently fired by the Milky Way nucleus; during its last episode of activity the jet was pointed toward the LMC. Quite recently, evidence for such a jet indeed appeared. We suggest that it was once energetic enough to trigger star formation in the LMC, and if the jet opening angle was about 2° then it could push out H i gas from a region of about 2 kpc in size, forming a cavity LMC4, but also squeeze two dense clouds that occurred in the same area, causing the formation of stars along their surfaces facing the core of the Milky Way. As a result, spherical segments of stellar shells might arise, visible now as the arcs named the Quadrant and Sextant, the apexes of which point towards the centre of the Milky Way. The orientation of both arcs could be the key to unlocking their origin. Here we give data that confirm the above hypothesis, amongst which are the radial velocities of stars inside and outside the larger of the LMC arcs. The probability is low that a jet from an active galactic nucleus (AGN) points towards a nearby galaxy and triggers star formation there, but a few other examples are now known or suspected.

  19. A maximum entropy approach to detect close-in giant planets around active stars

    NASA Astrophysics Data System (ADS)

    Petit, P.; Donati, J.-F.; Hébrard, E.; Morin, J.; Folsom, C. P.; Böhm, T.; Boisse, I.; Borgniet, S.; Bouvier, J.; Delfosse, X.; Hussain, G.; Jeffers, S. V.; Marsden, S. C.; Barnes, J. R.

    2015-12-01

    Context. The high spot coverage of young active stars is responsible for distortions of spectral lines that hamper the detection of close-in planets through radial velocity methods. Aims: We aim to progress towards more efficient exoplanet detection around active stars by optimizing the use of Doppler imaging in radial velocity measurements. Methods: We propose a simple method to simultaneously extract a brightness map and a set of orbital parameters through a tomographic inversion technique derived from classical Doppler mapping. Based on the maximum entropy principle, the underlying idea is to determine the set of orbital parameters that minimizes the information content of the resulting Doppler map. We carry out a set of numerical simulations to perform a preliminary assessment of the robustness of our method, using an actual Doppler map of the very active star HR 1099 to produce a realistic synthetic data set for various sets of orbital parameters of a single planet in a circular orbit. Results: Using a simulated time series of 50 line profiles affected by a peak-to-peak activity jitter of 2.5 km s-1, in most cases we are able to recover the radial velocity amplitude, orbital phase, and orbital period of an artificial planet down to a radial velocity semi-amplitude of the order of the radial velocity scatter due to the photon noise alone (about 50 m s-1 in our case). One noticeable exception occurs when the planetary orbit is close to co-rotation, in which case significant biases are observed in the reconstructed radial velocity amplitude, while the orbital period and phase remain robustly recovered. Conclusions: The present method constitutes a very simple way to extract orbital parameters from heavily distorted line profiles of active stars, when more classical radial velocity detection methods generally fail. It is easily adaptable to most existing Doppler imaging codes, paving the way towards a systematic search for close-in planets orbiting young, rapidly

  20. Secretly Eccentric: The Giant Planet and Activity Cycle of GJ 328

    NASA Astrophysics Data System (ADS)

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Boss, Alan P.

    2013-09-01

    We announce the discovery of a ~2 Jupiter-mass planet in an eccentric 11 yr orbit around the K7/M0 dwarf GJ 328. Our result is based on 10 years of radial velocity (RV) data from the Hobby-Eberly and Harlan J. Smith telescopes at McDonald Observatory, and from the Keck Telescope at Mauna Kea. Our analysis of GJ 328's magnetic activity via the Na I D features reveals a long-period stellar activity cycle, which creates an additional signal in the star's RV curve with amplitude 6-10 m s-1. After correcting for this stellar RV contribution, we see that the orbit of the planet is more eccentric than suggested by the raw RV data. GJ 328b is currently the most massive, longest-period planet discovered around a low-mass dwarf.

  1. SECRETLY ECCENTRIC: THE GIANT PLANET AND ACTIVITY CYCLE OF GJ 328

    SciTech Connect

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Boss, Alan P.

    2013-09-10

    We announce the discovery of a {approx}2 Jupiter-mass planet in an eccentric 11 yr orbit around the K7/M0 dwarf GJ 328. Our result is based on 10 years of radial velocity (RV) data from the Hobby-Eberly and Harlan J. Smith telescopes at McDonald Observatory, and from the Keck Telescope at Mauna Kea. Our analysis of GJ 328's magnetic activity via the Na I D features reveals a long-period stellar activity cycle, which creates an additional signal in the star's RV curve with amplitude 6-10 m s{sup -1}. After correcting for this stellar RV contribution, we see that the orbit of the planet is more eccentric than suggested by the raw RV data. GJ 328b is currently the most massive, longest-period planet discovered around a low-mass dwarf.

  2. Giant Optical Activity of Quantum Dots, Rods, and Disks with Screw Dislocations

    PubMed Central

    Baimuratov, Anvar S.; Rukhlenko, Ivan D.; Noskov, Roman E.; Ginzburg, Pavel; Gun’ko, Yurii K.; Baranov, Alexander V.; Fedorov, Anatoly V.

    2015-01-01

    For centuries mankind has been modifying the optical properties of materials: first, by elaborating the geometry and composition of structures made of materials found in nature, later by structuring the existing materials at a scale smaller than the operating wavelength. Here we suggest an original approach to introduce optical activity in nanostructured materials, by theoretically demonstrating that conventional achiral semiconducting nanocrystals become optically active in the presence of screw dislocations, which can naturally develop during the nanocrystal growth. We show the new properties to emerge due to the dislocation-induced distortion of the crystal lattice and the associated alteration of the nanocrystal’s electronic subsystem, which essentially modifies its interaction with external optical fields. The g-factors of intraband transitions in our nanocrystals are found comparable with dissymmetry factors of chiral plasmonic complexes, and exceeding the typical g-factors of chiral molecules by a factor of 1000. Optically active semiconducting nanocrystals—with chiral properties controllable by the nanocrystal dimensions, morphology, composition and blending ratio—will greatly benefit chemistry, biology and medicine by advancing enantiomeric recognition, sensing and resolution of chiral molecules. PMID:26424498

  3. A Series of Jets that Drove Streamer-Puff CMEs from Giant Active Region of 2014

    NASA Technical Reports Server (NTRS)

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    We investigate characteristics of solar coronal jets that originated from active region NOAA 12192 and produced coronal mass ejections (CMEs). This active region produced many non­-jet major flare eruptions (X and M class) that made no CME. A multitude of jets occurred from the southeast edge of the active region, and in contrast to the major-­flare eruptions in the core, six of these jets resulted in CMEs. Our jet observations are from SDO/AIA EUV channels and from Hinode/XRT, and CME observations are from the SOHO/LASCO C2 coronograph. Each jet-­driven CME was relatively slow-­moving (approx. 200 - 300 km/s) compared to most CMEs; had angular width (20deg - 50deg) comparable to that of the streamer base; and was of the "streamer­-puff" variety, whereby a pre-existing streamer was transiently inflated but not removed (blown out) by the passage of the CME. Much of the chromospheric-­temperature plasma of the jets producing the CMEs escaped from the Sun, whereas relatively more of the chromospheric plasma in the non-CME-producing jets fell back to the solar surface. We also found that the CME-producing jets tended to be faster in speed and longer in duration than the non-CME-­producing jets. We expect that the jets result from eruptions of mini-filaments. We further propose that the CMEs are driven by magnetic twist injected into streamer-­base coronal loops when erupting twisted mini-filament field reconnects with the ambient field at the foot of those loops.

  4. A Series of Jets that Drove Streamer-Puff CMEs from Giant Active Region of 2014

    NASA Technical Reports Server (NTRS)

    Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    We investigate characteristics of solar coronal jets that originated from active region NOAA 12192 and produced coronal mass ejections (CMEs). This active region produced many non-jet major flare eruptions (X and M class) that made no CME. A multiitude of jets occurred from the southeast edge of the active region, and in contrast to the major-flare eruptions in the core, six of these jets resulted in CMEs. Our jet observations are from multiple SDO/AIA EUV channels, including 304, 171 and 193 Angstrom, and CME observations are taken from SOHO/LASCO C2 coronograph. Each jet-driven CME was relatively slow-moving (approximately 200 - 300 km s(sup-1) compared to most CMEs; had angular width (20deg - 50deg) comparable to that of the streamer base; and was of the "streamer-puff" variety, whereby a preexisting streamer was transiently inflated but not removed (blown out) by the passage of the CME. Much of the chromospheric-temperature plasma of the jets producing the CMEs escaped from the Sun, whereas relatively more of the chromospheric plasma in the non-CME-producing jets fell back to the solar surface. We also found that the CME-producing jets tended to be faster in speed and longer in duration than the non-CME-producing jets. We expect that the jets result from eruptions of mini-filaments. We further propose that the CMEs are driven by magnetic twist injected into streamer-base coronal loops when erupting twisted mini-filament field reconnects with the ambient field at the foot of those loops.

  5. High-resolution mapping and transcriptional activity analysis of chicken centromere sequences on giant lampbrush chromosomes.

    PubMed

    Krasikova, Alla; Fukagawa, Tatsuo; Zlotina, Anna

    2012-12-01

    Exploration into morphofunctional organisation of centromere DNA sequences is important for understanding the mechanisms of kinetochore specification and assembly. In-depth epigenetic analysis of DNA fragments associated with centromeric nucleosome proteins has demonstrated unique features of centromere organisation in chicken karyotype: there are both mature centromeres, which comprise chromosome-specific homogeneous arrays of tandem repeats, and recently evolved primitive centromeres, which consist of non-tandemly organised DNA sequences. In this work, we describe the arrangement and transcriptional activity of chicken centromere repeats for Cen1, Cen2, Cen3, Cen4, Cen7, Cen8, and Cen11 and non-repetitive centromere sequences of chromosomes 5, 27, and Z using highly elongated lampbrush chromosomes, which are characteristic of the diplotene stage of oogenesis. The degree of chromatin packaging and fine spatial organisations of tandemly repetitive and non-tandemly repetitive centromeric sequences significantly differ at the lampbrush stage. Using DNA/RNA FISH, we have demonstrated that during the lampbrush stage, DNA sequences are transcribed within the centromere regions of chromosomes that lack centromere-specific tandem repeats. In contrast, chromosome-specific centromeric repeats Cen1, Cen2, Cen3, Cen4, Cen7, Cen8, and Cen11 do not demonstrate any transcriptional activity during the lampbrush stage. In addition, we found that CNM repeat cluster localises adjacent to non-repetitive centromeric sequences in chicken microchromosome 27 indicating that centromere region in this chromosome is repeat-rich. Cross-species FISH allowed localisation of the sequences homologous to centromeric DNA of chicken chromosomes 5 and 27 in centromere regions of quail orthologous chromosomes.

  6. Time-series Doppler imaging of the red giant HD 208472. Active longitudes and differential rotation

    NASA Astrophysics Data System (ADS)

    Özdarcan, O.; Carroll, T. A.; Künstler, A.; Strassmeier, K. G.; Evren, S.; Weber, M.; Granzer, T.

    2016-10-01

    Context. HD 208472 is among the most active RS CVn binaries with cool starspots. Decade-long photometry has shown that the spots seem to change their longitudinal appearance with a period of about six years, coherent with brightness variations. Aims: Our aim is to spatially resolve the stellar surface of HD 208472 and relate the photometric results to the true longitudinal and latitudinal spot appearance. Furthermore, we investigate the surface differential rotation pattern of the star. Methods: We employed three years of high-resolution spectroscopic data with a high signal-to-noise ratio (S/N) from the STELLA robotic observatory and determined new and more precise stellar physical parameters. Precalculated synthetic spectra were fit to each of these spectra, and we provide new spot-corrected orbital elements. A sample of 34 absorption lines per spectrum was used to calculate mean line profiles with a S/N of several hundred. A total of 13 temperature Doppler images were reconstructed from these line profiles with the inversion code iMap. Differential rotation was investigated by cross-correlating successive Doppler images in each observing season. Results: Spots on HD 208472 are distributed preferably at high latitudes and less frequently around mid-to-low latitudes. No polar-cap like structure is seen at any epoch. We observed a flip-flop event between 2009 and 2010, manifested as a flip of the spot activity from phase 0.0 to phase 0.5, while the overall brightness of the star continued to increase and reached an all-time maximum in 2014. Cross-correlation of successive Doppler images suggests a solar-like differential rotation that is ≈15 times weaker than that of the Sun. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP and IAC, and the Potsdam Automatic Photoelectric Telescopes (APT) in Arizona, jointly operated by AIP and Fairborn Observatory.Radial velocity measurements are only available at the

  7. Giant and switchable surface activity of liquid metal via surface oxidation

    PubMed Central

    Khan, Mohammad Rashed; Eaker, Collin B.; Bowden, Edmond F.; Dickey, Michael D.

    2014-01-01

    We present a method to control the interfacial tension of a liquid alloy of gallium via electrochemical deposition (or removal) of the oxide layer on its surface. In sharp contrast with conventional surfactants, this method provides unprecedented lowering of surface tension (∼500 mJ/m2 to near zero) using very low voltage, and the change is completely reversible. This dramatic change in the interfacial tension enables a variety of electrohydrodynamic phenomena. The ability to manipulate the interfacial properties of the metal promises rich opportunities in shape-reconfigurable metallic components in electronic, electromagnetic, and microfluidic devices without the use of toxic mercury. This work suggests that the wetting properties of surface oxides—which are ubiquitous on most metals and semiconductors—are intrinsic “surfactants.” The inherent asymmetric nature of the surface coupled with the ability to actively manipulate its energetics is expected to have important applications in electrohydrodynamics, composites, and melt processing of oxide-forming materials. PMID:25228767

  8. The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea): chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage

    NASA Astrophysics Data System (ADS)

    Taviani, M.; Angeletti, L.; Ceregato, A.; Foglini, F.; Froglia, C.; Trincardi, F.

    2013-01-01

    The geo-biological exploration of a pockmark field located at ca. -800 m in the Gela basin (Strait of Sicily, Central Mediterranean) provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such type of specialized deep-water cold-seep communities recorded from this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins. The thiotrophic chemosymbiotic organisms recovered from this area include empty tubes of the vestimentiferan Lamellibrachia sp., loose and articulated shells of lucinids (Lucinoma kazani, Myrtea amorpha), vesicomyids (Isorropodon perplexum), and gastropods (Taranis moerchi). A callianassid decapod (Calliax sp.) was consistently found alive in large numbers in the pockmark mud. Their post-mortem calcified parts mixed with molluscs and subordinately miliolid foraminifers form a distinct type of skeletal assemblage (named DECAMOL). Carbonate concretions display δ13C values as low as -40 ‰ PDB suggesting the occurrence of light hydrocarbons in the seeping fluids. Since none of the truly chemosymbiotic organisms was found alive, although their skeletal parts appear at times very fresh, some specimens have been AMS-14C dated to shed light on the historical evolution of this site. Lamellibrachia and Lucinoma are two of the most significant chemosymbiotic taxa reported from various Mediterranean cold seep sites (Alboran Sea and Eastern basin). Specimens from station MEDCOR78 (pockmark#1, Lat 36°46´10.18´´ N, Long 14°01´31.59´´ E, -815 m) provided ages of 11 736 ± 636 yr cal BP (Lamellibrachia sp.), and 9609.5 ± 153.5 yr cal BP (L. kazani). One shell of M. amorpha in core MEDCOR81 (pockmark#6, Lat 36°45´38.89´´ N, Long 14°00´07.58´´ E, -822 m) provided a sub-modern age of 484 ± 54 yr cal BP. These ages document that fluid seepage at this pockmark site has been episodically sustaining thiotrophic

  9. The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea): chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage

    NASA Astrophysics Data System (ADS)

    Taviani, M.; Angeletti, L.; Ceregato, A.; Foglini, F.; Froglia, C.; Trincardi, F.

    2013-07-01

    The geo-biological exploration of a pockmark field located at ca. 800 m below sea level in the Gela basin (Strait of Sicily, Central Mediterranean) provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such a type of specialised deep-water cold-seep communities recorded from this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins. The thiotrophic chemosymbiotic organisms recovered from this area include empty tubes of the vestimentiferan Lamellibrachia sp., loose and articulated shells of lucinids (Lucinoma kazani, Myrtea amorpha), vesicomyids (Isorropodon perplexum), and gastropods (Taranis moerchii). A callianassid decapod (Calliax sp.) was consistently found alive in large numbers in the pockmark mud. Their post-mortem calcified parts mixed with molluscs and subordinately miliolid foraminifers form a distinct type of skeletal assemblage. Carbonate concretions display δ13C values as low as -40‰ PDB suggesting the occurrence of light hydrocarbons in the seeping fluids. Since none of the truly chemosymbiotic organisms was found alive, although their skeletal parts appear at times very fresh, some specimens have been AMS-14C dated to shed light on the historical evolution of this site. Lamellibrachiav and Lucinoma are two of the most significant chemosymbiotic taxa reported from various Mediterranean cold seep sites (Alboran Sea and Eastern basin). Specimens from station MEDCOR78 (pockmark #1, Lat. 36°46´10.18" N, Long. 14°01´31.59" E, 815 m below sea level) provided ages of 11736 ± 636 yr cal BP (Lamellibrachia sp.), and 9609.5 ± 153.5 yr cal BP (L. kazani). One shell of M. amorpha in core MEDCOR81 (pockmark #6, Lat 36°45´38.89" N, Long 14°00´07.58" E, 822 m below sea level) provided a sub-modern age of 484 ± 54 yr cal BP. These ages document that fluid seepage at this pockmark site has been episodically

  10. Anti-solar differential rotation on the active sub-giant HU Virginis

    NASA Astrophysics Data System (ADS)

    Harutyunyan, G.; Strassmeier, K. G.; Künstler, A.; Carroll, T. A.; Weber, M.

    2016-08-01

    Context. Measuring surface differential rotation (DR) on different types of stars is important when characterizing the underlying stellar dynamo. It has been suggested that anti-solar DR laws can occur when strong meridional flows exist. Aims: We aim to investigate the differential surface rotation on the primary star of the RS CVn binary, HU Vir, by tracking its starspot distribution as a function of time. We also aim to recompute and update the values for several system parameters of the triple system HU Vir (close and wide orbits). Methods: Time-series high-resolution spectroscopy for four continuous months was obtained with the 1.2-m robotic STELLA telescope. Nine consecutive Doppler images were reconstructed from these data, using our line-profile inversion code iMap. An image cross-correlation method was applied to derive the surface differential-rotation law for HU Vir. New orbital elements for the close and the wide orbits were computed using our new STELLA radial velocities (RVs) combined with the RV data available in the literature. Photometric observations were performed with the Amadeus Automatic Photoelectric Telescope (APT), providing contemporaneous Johnson-Cousins V and I data for approximately 20 yrs. This data was used to determine the stellar rotation period and the active longitudes. Results: We confirm anti-solar DR with a surface shear parameter α of -0.029 ± 0.005 and -0.026 ± 0.009, using single-term and double-term differential rotation laws, respectively. These values are in good agreement with previously claimed results. The best fit is achieved assuming a solar-like double-term law with a lap time of ≈400 d. Our orbital solutions result in a period of 10.387678 ± 0.000003 days for the close orbit and 2726 ± 7 d (≈7.5 yr) for the wide orbit. A Lomb-Scarge (L-S) periodogram of the pre-whitened V-band data reveals a strong single peak providing a rotation period of 10.391 ± 0.008 d, well synchronized to the short orbit. Based on

  11. The p in p-T is for pressure: Movement of the gas hydrate stability field during glacial sealevel lowering and its possible link to pockmark formation on the Chatham Rise, New Zealand (Invited)

    NASA Astrophysics Data System (ADS)

    Pecher, I. A.; Davy, B. W.; Wood, R.; Carter, L.; Gohl, K.

    2010-12-01

    The discussion on a possible destabilization of gas hydrates caused by climate fluctuations has in recent years focused on the role of a sub-seafloor temperature increase following bottom-water warming. We here revisit the scenario that a pressure drop during glacial sealevel lowering could lead to gas hydrate dissociation. A >20,000 km2 field of seafloor depressions that we interpret as pockmarks has been identified on the southern flanks of the Chatham Rise. Three classes of pockmarks are present in two distinct water-depth ranges. The shallowest class of pockmarks with a diameter of ~150 m are present in a water-depth range of 500-700 m, close to the current top of the gas hydrate stability field. Sub-bottom profiler data show evidence for a bottom simulating reflection making it likely that gas hydrates are present beneath the seafloor. Furthermore, buried pockmarks are identified on horizons that we correlate with sealevel lowstands suggesting that pockmark formation is linked to sealevel lowering. Assuming constant bottom-water temperatures, a glacial sealevel drop by 120 m would move much of the seafloor that is covered with these pockmarks out of the gas hydrate stability field. We therefore suggest these pockmarks were formed by gas from dissociating gas hydrate due to depressurization following sealevel lowering. Two larger classes of pockmarks with diameters of 1-5 and ~10 km, respectively, are present in water depths of 800-1100 m. Here, the seafloor has probably remained within the gas hydrate stability field during sealevel lowstands. However, the associated pressure drop has moved the base of gas hydrate stability upwards by ~30 m. It is unclear whether bottom-water temperatures have changed significantly in our study area during glacial cycles - changes of 1-3° C would be required to have a similar effect on gas hydrate stability as sealevel fluctuations. The boundary between warmer subtropical and cold subantarctic waters, the subtropical front

  12. News from the "blowout", a man-made methane pockmark in the North Sea: chemosynthetic communities and microbial methane oxidation

    NASA Astrophysics Data System (ADS)

    Steinle, Lea I.; Wilfert, Philipp; Schmidt, Mark; Bryant, Lee; Haeckel, Matthias; Lehmann, Moritz F.; Linke, Peter; Sommer, Stefan; Treude, Tina; Niemann, Helge

    2013-04-01

    The accidental penetration of a base-Quaternary shallow gas pocket by a drilling rig in 1990 caused a "blowout" in the British sector of the North Sea (57°55.29' N, 01°37.86' E). Large quantities of methane have been seeping out of this man-made pockmark ever since. As the onset of gas seepage is well constrained, this site can be used as a natural laboratory to gain information on the development of methane oxidizing microbial communities at cold seeps. During an expedition with the R/V Celtic Explorer in July and August 2012, we collected sediments by video-guided push-coring with an ROV (Kiel 6000) along a gradient from inside the crater (close to where a jet of methane bubbles enters the water column) outwards. We also sampled the water column in a grid above the blowout at three different depths. In this presentation, we provide evidence for the establishment of methanotrophic communities in the sediment (AOM communities) on a time scale of decades. Furthermore, we will report data on methane concentrations and anaerobic methane oxidation rates in the sediment. Finally, we will also discuss the spatial distribution of methane and aerobic methane oxidation rates in the water column.

  13. Expression, purification, and evaluation for anticancer activity of ribosomal protein L31 gene (RPL31) from the giant panda (Ailuropoda melanoleuca).

    PubMed

    Su, Xiu-Lan; Hou, Yi-Ling; Yan, Xiang-Hui; Ding, Xiang; Hou, Wan-Ru; Sun, Bing; Zhang, Si-Nan

    2012-09-01

    Ribosomal protein L31 gene is a component of the 60S large ribosomal subunit encoded by RPL31 gene, while ribosomal protein L31 (RPL31) is an important constituent of peptidyltransferase center. In our research, the cDNA and the genomic sequence of RPL31 were cloned successfully from the giant panda (Ailuropoda melanoleuca) using RT-PCR technology respectively, following sequencing and analyzing preliminarily. We constructed a recombinant expression vector contained RPL31 cDNA and over-expressed it in Escherichia coli using pET28a plasmids. The expression product was purified to obtain recombinant protein of RPL31 from the giant panda. Recombinant protein of RPL31 obtained from the experiment acted on human laryngeal carcinoma Hep-2 and human hepatoma HepG-2 cells for study of its anti-cancer activity by MTT [3-(4, 5-dimehyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide] method. Then observe these cells growth depressive effect. The result indicated that the cDNA fragment of the RPL31 cloned from the giant panda is 419 bp in size, containing an open reading frame of 378 bp, and deduced protein was composed of 125 amino acids with an estimated molecular weight of 14.46-kDa and PI of 11.21. The length of the genomic sequence is 8,091 bp, which was found to possess four exons and three introns. The RPL31 gene can be readily expressed in E.coli, expecting 18-kDa polypeptide that formed inclusion bodies. Recombinant protein RPL31 from the giant panda consists of 157 amino acids with an estimated molecular weight of 17.86 kDa and PI of 10.77. The outcomes showed that the cell growth inhibition rate in a time- and dose-dependent on recombinant protein RPL31. And also indicated that the effect at low concentrations was better than high concentrations on Hep-2 cells, and the concentration of 0.33 μg/mL had the best rate of growth inhibition, 44 %. Consequently, our study aimed at revealing the recombinant protein RPL31 anti-cancer function from the giant panda

  14. Overexpression, purification, and pharmacologic evaluation of anticancer activity of ribosomal protein L24 from the giant panda (Ailuropoda melanoleuca).

    PubMed

    Hou, Y L; Ding, X; Hou, W; Song, B; Wang, T; Wang, F; Li, J; Zhong, J; Xu, T; Ma, B X; Zhu, H Q; Li, J H; Zhong, J C

    2013-10-18

    The ribosomal protein L24 (RPL24) belongs to the L24E family of ribosomal proteins and is located in the cytoplasm. The purpose of this study was to investigate the structure and anti-cancer function of RPL24 of the giant panda (Ailuropoda melanoleuca). The complementary DNA of RPL24 was cloned successfully using reverse transcription-polymerase chain reaction technology. We constructed a recombinant expression vector containing RPL24 complementary DNA and overexpressed it in Escherichia coli using pET28a plasmids. The expression product obtained was purified using Ni-chelating affinity chromatography. The results indicated that the length of the fragment cloned is 509 bp, and it contains an open-reading frame of 474 bp encoding 157 amino acids. Primary structure analysis revealed that the molecular weight of the putative RPL24 protein is 17.78 kDa with a theoretical isoelectric point of 11.86. The RPL24 gene is readily expressed in E. coli, and the RPL24 fused with the N-terminal histidine-tagged protein to give rise to the accumulation of an expected 23.51-kDa polypeptide. The inhibitory rate in mice treated with 0.1 mg/mL RPL24, the highest of 3 doses administered, can reach 67.662%, which may be comparable to the response to mannatide. The histology of organs with tumors showed that the tissues in the RPL24 group displayed a looser arrangement compared with that in the control group. Furthermore, no obvious damage was apparent in other organs, such as heart, lung, and kidney. The data showed that the recombinant RPL24 had time and dose dependency on the cell growth inhibition rate. Human laryngeal carcinoma Hep-2 cells treated with 0.3125-10 µg/mL RPL24 for 24 h displayed significant cell growth inhibition (P < 0.05; N = 6) in assays using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide compared with that in control (untreated) cells. By contrast, human hepatoma Hep G-2 cells displayed no significant change (P > 0.05; N = 6) from control

  15. Giant Magnons Meet Giant Gravitons

    SciTech Connect

    Hofman, Diego M.

    2008-07-28

    We study the worldsheet reflection matrix of a string attached to a D-brane in AdS{sub 5}xS{sup 5}. The D-brane corresponds to a maximal giant graviton that wraps an S{sup 3} inside S{sup 5}. In the gauge theory, the open string is described by a spin chain with boundaries. We focus on open strings with a large SO(6) charge and define an asymptotic boundary reflection matrix. Using the symmetries of the problem, we review the computation of the boundary reflection matrix, up to a phase. We also discuss weak and strong coupling computations where we obtain the overall phase factor and test our exact results.

  16. Clump Giants in the Hyades

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard F. (Technical Monitor); Brickhouse, Nancy

    2003-01-01

    The project is entitled 'Clump Giants in the Hyades.' This observation of one of the late-type Hyades giants (Gamma Tau) has implications for understanding the formation of late-type stellar coronae as a function of the evolutionary state of the star. The Hyades giants are interesting because they are all clump giants in the Helium burning phase, similar to the cool primary of Capella. The Hyades giants show significantly more magnetic activity than expected from their state of evolution (and slowed-down rotation). Thus these systems provide an important clue to dynamo action. The data were obtained by the satellite on 13 March 2001 for a total RGS exposure of 58220 seconds. These data were delivered to the PI on 7 August 2001. The data could not be reprocessed until SAS Version 5.3.3 which became available 7 June 2002. Although the guidelines for assessing background rates suggested that half the data were contaminated, it does not appear that the spectral region of the RGS was adversely affected by unusually high background. The spectra show strong lines of Fe XVII and XVIII, O VII and VIII, Ne IX and X, along with numerous weaker lines. The emission measure distribution is highly reminiscent of Capella; if anything, the emission measure distribution is steeper at 6 million K than for Capella. Gamma Tau is the second brightest of the Hyades clump giants. Pallavicini et al. have shown that the luminosity of the brightest Hyades giant (Theta Tau) is remarkably similar to its luminosity as measured by Einstein. Short-term variability is also modest. We are addressing the variability issue now for Gamma Tau. Initial results were reported at the 2003 Seattle AAS meeting. A paper is in preparation for submission to the Astrophysical Journal.

  17. Giant left ventricular pseudoaneurysm.

    PubMed

    Prakash, Sumi; Garg, Nadish; Xie, Gong-Yuan; Dellsperger, Kevin C

    2010-01-01

    Left ventricular (LV) pseudoaneurysm (PS) is an uncommon, often fatal complication associated with myocardial infarction, cardiothoracic surgery, trauma, and, rarely, infective endocarditis. A 28-year-old man with prior history of bioprosthetic mitral valve replacement presented with congestive heart failure and bacteremia with Abiotrophia granulitica. Transesophageal echocardiogram showed bioprosthesis dysfunction, large vegetations, mitral regurgitation, and probable PS. Cardiac and chest CT confirmed a PS communicating with the left ventricle Patient had pulseless electrical activity and died. Autopsy showed a giant PS with layered thrombus and pseudo-endothelialized cavity. Our case highlights the importance of multimodality imaging as an important tool in management of PS.

  18. Transforming giants.

    PubMed

    Kanter, Rosabeth Moss

    2008-01-01

    Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big.

  19. Giant Cell Arteritis

    MedlinePlus

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  20. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2013-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010/2012 impact flash detections and lightcurve measurements}.We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere {10^20 J}.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  1. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2014-10-01

    The 2009 impact and recent superbolides on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution (enabling the 2009 impact debris field detection) and rapid frame rates (enabling the 2010/2012 impact flash detections and lightcurve measurements).We propose a ToO program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere (10^20 J).HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing (not achievable from the ground) is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  2. Giant impacts on giant planets

    NASA Astrophysics Data System (ADS)

    de Pater, Imke

    2012-10-01

    The 2009 impact on Jupiter caught the world by surprise and cast doubt on impactor flux estimates for the outer solar system. Enhanced amateur planetary imaging techniques yield both high spatial resolution {enabling the 2009 impact debris field detection} and rapid frame rates {enabling the 2010 impact flash detections and lightcurve measurements}.We propose a Target of Opportunity program to image future impacts on Jupiter and Saturn. To remove the possibility of impact cloud non-detections, the program will be triggered only if an existing impact debris field is seen, an object on a collision course with Jupiter or Saturn is discovered, or an impact light curve is measured with an estimated total energy large enough to generate an impact cloud in a giant planet atmosphere.HST provides the only way to image these events in the ultraviolet, providing information on aerosol altitudes and on smaller particles that are less visible to ground-based infrared observations. High-resolution imaging with proper timing {not achievable from the ground} is required to measure precisely both the velocity fields of impact sites and the optical spectrum of impact debris. HST observations of past impacts on Jupiter have also served both as cornerstones of science investigations at other wavelengths and as vehicles for effective public outreach.Large outer solar system impacts are governed by the same physics as in the terrestrial events that dominate the impact threat to humans. Studying the behavior of impactors of various sizes and compositions, as they enter the atmosphere at varying angles and speeds, will better quantify terrestrial impact hazards.

  3. Coexpression of interleukin-6 and -2 from giant panda in Escherichia coli and the biological activity of the fusion protein.

    PubMed

    Yi, Y; Nian, Y-Y; Ji, H-W; Zhang, H; Zhu, L; Xu, Z-W

    2013-06-14

    To construct a fusion cytokine protein with more and stronger bioactivities to enhance the immunity of the cytokine alone, we expressed interleukin (IL)-6/(IL)-2 from giant panda (Ailuropoda melanoleuca) in Escherichia coli as a 59.4-kDa fusion protein. Subsequently, the inclusion bodies were solubilized with 8 M urea and applied onto a Ni-nitrilotriacetic acid column. The final production of IL-6/IL-2 reached 6 mg/L in soluble form, and the purified final product was >96% pure. In Western blot assays, the recombinant IL-6/IL-2 was recognized by polyclonal antibodies against IL-6 and IL-2 of giant panda. The results demonstrated that the protein mixture contained correctly folded IL-2 and IL-6 proteins. A 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide assay demonstrated that IL-6/IL-2 can promote lymphocyte proliferation and differentiation. These data suggest that the fusion protein could be used to develop a novel immunoadjuvant to enhance the immunity of animals against infectious diseases.

  4. Monitoring Of The Magnetic Field Topology And Activity Of The Core Helium-Burning Giant Beta Ceti In The Period 2010-2013

    NASA Astrophysics Data System (ADS)

    Tsvetkova, Svetla; Petit, Pascal; Konstantinova-Antova, Renada; Aurière, Michel; Wade, Gregg A.; Charbonnel, Corinne; Bogdanovski, Rumen; Borisova, Ana

    2016-07-01

    Beta Ceti is a slowly rotating (v sin i = 3.5 kms-1) single giant. In our previous study (Tsvetkova et al. (2013)) we showed that it is in the core He-burning phase and we reconstructed two Zeeman Doppler imaging (ZDI) maps (using data from 2010 and 2011) revealing a simple large-scale magnetic field structure. We concluded that the magnetic field of beta Ceti could have a fossil field origin. In addition, the study of Aurière et al. (2015) about the properties and origin of the magnetism of late-type giants, where beta Ceti was a member of that sample, revealed that this star did not follow the general trends for dynamo-generated magnetic fields. Now, we present a new ZDI map of beta Ceti and compare the new results with our previous study. This monitoring for several years of the magnetic field topology and line activity indicators variability supports our previous conclusion about the fossil field origin of the magnetic field of beta Ceti.

  5. Molecular Profiling of Giant Cell Tumor of Bone and the Osteoclastic Localization of Ligand for Receptor Activator of Nuclear Factor κB

    PubMed Central

    Morgan, Teresa; Atkins, Gerald J.; Trivett, Melanie K.; Johnson, Sandra A.; Kansara, Maya; Schlicht, Stephen L.; Slavin, John L.; Simmons, Paul; Dickinson, Ian; Powell, Gerald; Choong, Peter F.M.; Holloway, Andrew J.; Thomas, David M.

    2005-01-01

    Giant cell tumor of bone (GCT) is a generally benign, osteolytic neoplasm comprising stromal cells and osteoclast-like giant cells. The osteoclastic cells, which cause bony destruction, are thought to be recruited from normal monocytic pre-osteoclasts by stromal cell expression of the ligand for receptor activator of nuclear factor κB (RANKL). This model forms the foundation for clinical trials in GCTs of novel cancer therapeutics targeting RANKL. Using expression profiling, we identified both osteoblast and osteoclast signatures within GCTs, including key regulators of osteoclast differentiation and function such as RANKL, a C-type lectin, osteoprotegerin, and the wnt inhibitor SFRP4. After ex vivo generation of stromal- and osteoclast-enriched cultures, we unexpectedly found that RANKL mRNA and protein were more highly expressed in osteoclasts than in stromal cells, as determined by expression profiling, flow cytometry, immunohistochemistry, and reverse transcriptase-polymerase chain reaction. The expression patterns of molecules implicated in signaling between stromal cells and monocytic osteoclast precursors were analyzed in both primary and fractionated GCTs. Finally, using array-based comparative genomic hybridization, neither GCTs nor the derived stromal cells demonstrated significant genomic gains or losses. These data raise questions regarding the role of RANKL in GCTs that may be relevant to the development of molecularly targeted therapeutics for this disease. PMID:15972958

  6. Long-term fluid expulsion revealed by carbonate crusts and pockmarks connected to subsurface gas anomalies and palaeo-channels in the central North Sea

    NASA Astrophysics Data System (ADS)

    Chand, Shyam; Crémière, Antoine; Lepland, Aivo; Thorsnes, Terje; Brunstad, Harald; Stoddart, Daniel

    2016-11-01

    Gas seepage through the seafloor into the water column is inferred based on acoustic mapping, video observations and geochemical analyses at multiple locations in the Viking Graben and Utsira High areas of the central North Sea. Flares in the Viking Graben occur both inside and along the periphery of a submarine melt water channel where pockmarks (up to 500 m in diameter) and methane-derived carbonate crusts are found on the seafloor, indicating focussing of fluid flow in the vicinity of the channel. The flares can be related to gas accumulations close to the seafloor as well as in Quaternary and deeper strata, observed as high-amplitude reflections on seismic data. Many palaeo-channels, which act as accumulation zones, are observed in the subsurface of both the Viking Graben and Utsira High areas. The deeper origin of gas is partially supported by results of isotope analyses of headspace gas collected from sediment samples of the Viking Graben, which show a mixed microbial/thermogenic origin whereas isotope data on free seeping gas in the Viking Graben indicate a predominantly microbial origin. Based on these lines of evidence, a structure-controlled fluid flow model is proposed whereby hydrocarbons migrate in limited amount from deep thermogenic reservoirs along faults, and these deep fluids are strongly diluted by microbial methane. Moreover, the existence of subsurface pockmarks at several stratigraphic levels indicates long-term fluid flow, interpreted to be caused by gas hydrate destabilisation and stress-related high overpressures.

  7. Comparative study on the sensitivity of turions and active fronds of giant duckweed (Spirodela polyrhiza (L.) Schleiden) to heavy metal treatments.

    PubMed

    Oláh, Viktor; Hepp, Anna; Mészáros, Ilona

    2015-08-01

    Standard ecotoxicological test procedures use only active forms of aquatic plants. The potential effects of toxicants on vegetative propagules, which play an important role in the survival of several aquatic plant species, is not well understood. Because turion-like resting propagules overwinter on the water bottom in temperate regions, they could be exposed to contaminants for longer periods than active plants. Due to its turion producing capability, giant duckweed (Spirodela polyrhiza) is widely used in studying morphogenesis, dormancy, and activation mechanisms in plants. It is also suitable for ecotoxicological purposes. The present work aims to compare the growth inhibition sensitivity of active (normal frond) and overwintering (turion) forms of S. polyrhiza to concentrations of nickel (Ni), cadmium (Cd) and hexavalent chromium (Cr) ranging from 0 to 100mgL(-1). The results indicated that in general, resting turions have higher heavy metal tolerance than active fronds. Cd proved to be the most toxic heavy metal to S. polyrhiza active frond cultures because it induced rapid turion formation. In contrast, the toxicity of Ni and Cr were found to be similar but lower than the effects of Cd. Cr treatments up to 10mgL(-1) did not result in any future negative effects on turion activation. Turions did not survive heavy metal treatments at higher concentrations of Cr. Cd and Ni treatments affected both the floating-up and germination of turions but did not significantly affect the vigor of sprouts. Higher concentrations (of 100mgL(-1)) Cd completely inhibited germination.

  8. The Electric Giant Resonances

    NASA Astrophysics Data System (ADS)

    van der Woude, A.

    The following sections are included: * Introduction * Experimental Methods to Study Giant Resonances * Introduction * The Tools * Introduction * Tools for Isoscalar Scattering * INELASTIC α-SCATTERING * INELASTIC PROTON SCATTERING * Tools for Isovector Excitations * γ-ABSORPTION AND PARTICLE CAPTURE REACTIONS * CHARGE EXCHANGE REACTIONS - THE (π+, π0) REACTION * Tools For Isoscalar And Isovector Excitations * INELASTIC ELECTRON SCATTERING * GIANT RESONANCE EXCITATION BY FAST HEAVY IONS * From Multipole Cross Section To Multipole Strength * The Electric Isoscalar Resonances * The Isoscalar Giant Monopole Resonance * Systematics on the GMR * Compressibility and the Giant Monopole Resonance * Introduction * The Compressibility of nuclear matter from the GMR energies * Discussion * The Isoscalar Giant Quadrupole Resonance * General Trends In Medium-Heavy and Heavy Nuclei * The GQR In Light Nuclei * The Isoscalar 3- Strength, LEOR and HEOR * Isoscalar 4+ Strength * Miscellaneous; Isoscalar 1- and L > 4-Strength * The Electric Isovector Giant Resonances * The Isovector Giant Dipole Resonance: GDR * The Isovector Giant Monopole Resonances: IVGMR * The Isovector Quadrupole Resonance: IVGQR * The Effect of Ground State Deformation on the Shape of Giant Resonance: Microscopic Picture * Giant Resonances Built on Excited States * Introduction * Capture Reactions on Light Nuclei * Statistical decay of GDR γ Emission in Heavy Compound Systems * Introduction * Theoretical Predictions * Some Experimental Results * Summary and Outlook * Acknowledgements * General References * References

  9. The impact of increased sedimentation rates associated with the decay of the Fennoscandian ice-sheet on gas hydrate stability and focused fluid flow at the Nyegga pockmark field, offshore mid-Norway

    NASA Astrophysics Data System (ADS)

    Karstens, Jens; Haflidason, Haflidi; Becker, Lukas; Petter Sejrup, Hans; Berndt, Christian; Planke, Sverre; Dahlgreen, Torbjørn

    2016-04-01

    Climatic changes since the Last Glacial Maximum (LGM) have affected the stability of gas hydrate systems on glaciated margins by sea-level changes, bottom water temperature changes, isostatic uplift or subsidence and variability in sedimentation rates. While subsidence and sea-level rise stabilize gas hydrate deposits, bottom water temperature warming, uplift and enhanced sedimentation have the opposite effect. The response of gas hydrate systems to post-glaciation warming is therefore a complex phenomenon and highly depends on the timing and magnitude of each of these processes. While the impact of bottom water warming on the dissociation of gas hydrates have been addressed in numerous studies, the potential of methane release due to basal gas hydrate dissociation during periods of warming has received less attention. Here, we present results from numerical simulations which show that rapid sedimentation associated with the decay of the Fennoscandian ice-sheet was capable of causing significant basal gas hydrate dissociation. The modeling is constrained by a high-resolution three-dimensional sedimentation rate reconstruction of the Nyegga pockmark field, offshore mid-Norway, obtained by integrating chrono-stratigraphic information derived from sediments cores and a seismo-stratigraphic framework. The model run covers the period between 28,000 and 15,000 calendar years before present and predict that the maximum sedimentation rate-related gas hydrate dissociation coincides temporally and spatially with enhanced focused fluid flow activity in the study area. Basal gas hydrate dissociation due to rapid sedimentation may have occurred as well in other glaciated continental margins after the LGM and may have caused the release of significant amounts of methane to the hydrosphere and atmosphere. The major post glaciation deposition centers are the location of some of the largest known submarine slide complexes. The release of free gas due to basal gas hydrate

  10. The action of alcohols and other non-ionic surface active substances on the sodium current of the squid giant axon.

    PubMed Central

    Haydon, D A; Urban, B W

    1983-01-01

    The effects of several n-alkanols and n-alkyl oxyethylene alcohols, methyl octanoate, glycerol 1-monooctanoate and dioctanoyl phosphatidylcholine on the ionic currents and electrical capacity of the squid giant axon membrane have been examined. The peak inward current in voltage-clamped axons was reduced reversibly by each substance. For n-pentanol to n-decanol the concentrations required to suppress the peak inward current by 50% were determined. From these data, it was estimated that the standard free energy per CH2 for adsorption to the site of action was -3.04 kJ mole-1, as compared with -3.11 kJ mole-1 for adsorption into phospholipid bilayers or an n-alkane/aqueous solution interface. The membrane capacity at 100 kHz was not greatly by any of the test substances at concentrations which reduced the inward current by 50%. Na currents under voltage clamp were recorded in intracellularly perfused axons before, during and sometimes after exposure to the test substances and the records were fitted with equations similar to those proposed by Hodgkin & Huxley (1952). Shifts in the curves of the steady-state activation and inactivation parameters (m infinity and h infinity) against membrane potential, changes in the peak heights of the activation and inactivation time constants (tau m and tau h) and reductions in the maximum Na conductance (gNa) have been tabulated. All of the test substances shifted the voltage dependence of the steady-state activation in the depolarizing direction and lowered the peak time constants for both activation and inactivation. The origins of these effects, and of the differences in the present results from those of the hydrocarbons (Haydon & Urban, 1983), have been discussed in terms of the physico-chemical properties of the two groups of substances and with reference to their effects on artificial membranes. PMID:6312030

  11. Overexpression, purification, molecular characterization and pharmacological evaluation for anticancer activity of ribosomal protein S23 from the giant panda (Ailuropoda melanoleuca).

    PubMed

    Wang, Ting; Hou, Yiling; Ding, Xiang; Song, Bo; Wang, Fang; Hou, Wanru

    2013-06-01

    Ribosomal protein S23 (RPS23) is a component of the 40S small ribosomal subunit encoded by the RPS23 gene, which is specific to eukaryotes. The cDNA and genomic sequence of RPS23 were cloned from Ailuropoda melanoleuca (A. melanoleuca) using reverse transcription‑polymerase chain reaction (RT-PCR) technology and touchdown PCR, respectively. The two sequences were analyzed preliminarily and the cDNA of the RPS23 gene was overexpressed in Escherichia coli (E. coli) BL21. The cDNA of RPS23 cloned from giant panda was 472 bp, and it contained an open reading frame (ORF) of 432 bp encoding 142 amino acids. The nucleotide sequence of the coding sequence showed a high degree of homology to some mammals as determined by BLAST analysis, similar to the amino acid sequence. The genomic sequence was 2,105 bp in length, with 4 exons and 3 introns. The primary structure analysis revealed that the molecular weight of the putative RPS23 protein was 15.80 kDa with a theoretical isoelectric point (pI) of 11.23. The molecular weight of the recombinant protein RPS23 was 21.5 kDa with a theoretical pI of 10.57. Topology prediction showed that there are seven different patterns of functional sites in the RPS23 protein of giant panda. RPS23 was successfully expressed in E. coli and its protein fused with the N‑terminal His‑tagged protein triggered the accumulation of an expected 21.5‑kDa polypeptide. The inhibitory rate of tumor growth in mice treated with 0.1 µg/ml RPS23 protein was 49.45%, the highest in the three doses used, which may be comparable to mannatide treatment. Histology of immune organs showed that the tissues were characterized by a regular and tight arrangement, while tumor tissues of the mice in the RPS23 group exhibited a loose arrangement compared to the control group. However, there was no obvious damage to other organs, such as the heart, lung and kidney. Investigations are currently being conducted to determine the bioactive principles of the recombinant

  12. cDNA cloning, overexpression, purification and pharmacologic evaluation for anticancer activity of ribosomal protein L23A gene (RPL23A) from the Giant Panda.

    PubMed

    Sun, Bing; Hou, Yi-Ling; Hou, Wan-Ru; Zhang, Si-Nan; Ding, Xiang; Su, Xiu-Lan

    2012-01-01

    RPL23A gene encodes a ribosomal protein that is a component of the 60S subunit. The protein belongs to the L23P family of ribosomal proteins, which is located in the cytoplasm. The purpose of this paper was to explore the structure and anti-cancer function of ribosomal protein L23A (RPL23A) gene of the Giant Panda (Ailuropoda melanoleuca). The cDNA of RPL23A was cloned successfully from the Giant Panda using RT-PCR technology. We constructed a recombinant expression vector containing RPL23A cDNA and over-expressed it in Escherichia coli using pET28a plasmids. The expression product obtained was purified by using Ni chelating affinity chromatography. Recombinant protein of RPL23A obtained from the experiment acted on Hep-2 cells and human HepG-2 cells, then the growth inhibitory effect of these cells was observed by MTT (3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide) assay. The result indicated that the length of the fragment cloned is 506 bp, and it contains an open-reading frame (ORF) of 471 bp encoding 156 amino acids. Primary structure analysis revealed that the molecular weight of the putative RPL23A protein is 17.719 kDa with a theoretical pI 11.16. The molecular weight of the recombinant protein RPL23A is 21.265 kDa with a theoretical pI 10.57. The RPL23A gene can be really expressed in E. coli and the RPL23A protein, fusioned with the N-terminally His-tagged protein, gave rise to the accumulation of an expected 22 KDa polypeptide. The data showed that the recombinant protein RPL23A had a time- and dose-dependency on the cell growth inhibition rate. The data also indicated that the effect at low concentrations was better than at high concentrations on Hep-2 cells, and that the concentration of 0.185 μg/mL had the best rate of growth inhibition of 36.31%. All results of the experiment revealed that the recombinant protein RPL23A exhibited anti-cancer function on the Hep-2 cells. The study provides a scientific basis and aids orientation for

  13. Unstable giant gravitons

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Smolic, Jelena; Smolic, Milena

    2006-03-15

    We find giant graviton solutions in Frolov's three parameter generalization of the Lunin-Maldacena background. The background we study has {gamma}-tilde{sub 1}=0 and {gamma}-tilde{sub 2}={gamma}-tilde{sub 3}={gamma}-tilde. This class of backgrounds provides a nonsupersymmetric example of the gauge theory/gravity correspondence that can be tested quantitatively, as recently shown by Frolov, Roiban, and Tseytlin. The giant graviton solutions we find have a greater energy than the point gravitons, making them unstable states. Despite this, we find striking quantitative agreement between the gauge theory and gravity descriptions of open strings attached to the giant.

  14. The Next Giant Step

    NASA Video Gallery

    Artist Robert McCall painted "The Next Giant Step" in 1979 to commemorate the heroism and courage of spaceflight pioneers. Located in the lobby of Johnson's building 2, the mural depicts America's ...

  15. The Giant Cell.

    ERIC Educational Resources Information Center

    Stockdale, Dennis

    1998-01-01

    Provides directions for the construction of giant plastic cells, including details for building and installing the organelles. Also contains instructions for preparing the ribosomes, nucleolus, nucleus, and mitochondria. (DDR)

  16. Investigation of antibacterial activity of Bacillus spp. isolated from the feces of Giant Panda and characterization of their antimicrobial gene distributions.

    PubMed

    Zhou, Ziyao; Zhou, Xiaoxiao; Zhong, Zhijun; Wang, Chengdong; Zhang, Hemin; Li, Desheng; He, Tingmei; Li, Caiwu; Liu, Xuehan; Yuan, Hui; Ji, Hanli; Luo, Yongjiu; Gu, Wuyang; Fu, Hualin; Peng, Guangneng

    2014-12-01

    Bacillus group is a prevalent community of Giant Panda's intestinal flora, and plays a significant role in the field of biological control of pathogens. To understand the diversity of Bacillus group from the Giant Panda intestine and their functions in maintaining the balance of the intestinal microflora of Giant Panda, this study isolated a significant number of strains of Bacillus spp. from the feces of Giant Panda, compared the inhibitory effects of these strains on three common enteric pathogens, investigated the distributions of six universal antimicrobial genes (ituA, hag, tasA, sfp, spaS and mrsA) found within the Bacillus group by PCR, and analyzed the characterization of antimicrobial gene distributions in these strains using statistical methods. The results suggest that 34 strains of Bacillus spp. were isolated which has not previously been detected at such a scale, these Bacillus strains could be classified into five categories as well as an external strain by 16S rRNA; Most of Bacillus strains are able to inhibit enteric pathogens, and the antimicrobial abilities may be correlated to their categories of 16S rRNA; The detection rates of six common antimicrobial genes are between 20.58 %(7/34) and 79.41 %(27/34), and genes distribute in three clusters in these strains. We found that the antimicrobial abilities of Bacillus strains can be one of the mechanisms by which Giant Panda maintains its intestinal microflora balance, and may be correlated to their phylogeny.

  17. DISCOVERY OF ULTRA-STEEP SPECTRUM GIANT RADIO GALAXY WITH RECURRENT RADIO JET ACTIVITY IN ABELL 449

    SciTech Connect

    Hunik, Dominika; Jamrozy, Marek

    2016-01-20

    We report a discovery of a 1.3 Mpc diffuse radio source with extremely steep spectrum fading radio structures in the vicinity of the Abell 449 cluster of galaxies. Its extended diffuse lobes are bright only at low radio frequencies and their synchrotron age is about 160 Myr. The parent galaxy of the extended relic structure, which is the dominant galaxy within the cluster, is starting a new jet activity. There are three weak X-rays sources in the vicinity of the cluster as found in the ROSAT survey, however it is not known if they are connected with this cluster of galaxies. Just a few radio galaxy relics are currently known in the literature, as finding them requires sensitive and high angular resolution low-frequency radio observations. Objects of this kind, which also are starting a new jet activity, are important for understanding the life cycle and evolution of active galactic nuclei. A new 613 MHz map as well as the archival radio data pertaining to this object are presented and analyzed.

  18. Recombinant production of biologically active giant grouper (Epinephelus lanceolatus) growth hormone from inclusion bodies of Escherichia coli by fed-batch culture.

    PubMed

    Chung, Wen-Jen; Huang, Chi-Lung; Gong, Hong-Yi; Ou, Tsung-Yin; Hsu, Jue-Liang; Hu, Shao-Yang

    2015-06-01

    Growth hormone (GH) performs important roles in regulating somatic growth, reproduction, osmoregulation, metabolism and immunity in teleosts, and thus, it has attracted substantial attention in the field of aquaculture application. Herein, giant grouper GH (ggGH) cDNA was cloned into the pET28a vector and expressed in Shuffle® T7 Competent Escherichia coli. Recombinant N-terminal 6× His-tagged ggGH was produced mainly in insoluble inclusion bodies; the recombinant ggGH content reached 20% of total protein. For large-scale ggGH production, high-cell density E. coli culture was achieved via fed-batch culture with pH-stat. After 30h of cultivation, a cell concentration of 41.1g/l dry cell weight with over 95% plasmid stability was reached. Maximal ggGH production (4.0g/l; 22% total protein) was achieved via mid-log phase induction. Various centrifugal forces, buffer pHs and urea concentrations were optimized for isolation and solubilization of ggGH from inclusion bodies. Hydrophobic interactions and ionic interactions were the major forces in ggGH inclusion body formation. Complete ggGH inclusion body solubilization was obtained in PBS buffer at pH 12 containing 3M urea. Through a simple purification process including Ni-NTA affinity chromatography and refolding, 5.7mg of ggGH was obtained from 10ml of fed-batch culture (45% recovery). The sequence and secondary structure of the purified ggGH were confirmed by LC-MS/MS mass spectrometry and circular dichroism analysis. The cell proliferation-promoting activity was confirmed in HepG2, ZFL and GF-1 cells with the WST-1 colorimetric bioassay.

  19. Method of making active magnetic refrigerant, colossal magnetostriction and giant magnetoresistive materials based on Gd-Si-Ge alloys

    DOEpatents

    Gschneidner, Jr., Karl A.; Pecharsky, Alexandra O.; Pecharsky, Vitalij K.

    2003-07-08

    Method of making an active magnetic refrigerant represented by Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4 alloy for 0.ltoreq.x.ltoreq.1.0 comprising placing amounts of the commercially pure Gd, Si, and Ge charge components in a crucible, heating the charge contents under subambient pressure to a melting temperature of the alloy for a time sufficient to homogenize the alloy and oxidize carbon with oxygen present in the Gd charge component to reduce carbon, rapidly solidifying the alloy in the crucible, and heat treating the solidified alloy at a temperature below the melting temperature for a time effective to homogenize a microstructure of the solidified material, and then cooling sufficiently fast to prevent the eutectoid decomposition and improve magnetocaloric and/or the magnetostrictive and/or the magnetoresistive properties thereof.

  20. Giant congenital melanocytic nevus*

    PubMed Central

    Viana, Ana Carolina Leite; Gontijo, Bernardo; Bittencourt, Flávia Vasques

    2013-01-01

    Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion. PMID:24474093

  1. Giant congenital melanocytic nevus.

    PubMed

    Viana, Ana Carolina Leite; Gontijo, Bernardo; Bittencourt, Flávia Vasques

    2013-01-01

    Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion.

  2. Anti-white spot syndrome virus activity of Ceriops tagal aqueous extract in giant tiger shrimp Penaeus monodon.

    PubMed

    Sudheer, N S; Philip, Rosamma; Bright Singh, I S

    2012-09-01

    White spot syndrome virus (WSSV), the most contagious pathogen of cultured shrimp, causes mass mortality, leading to huge economic loss to the shrimp industry. The lack of effective therapeutic or prophylactic measures has aggravated the situation, necessitating the development of antiviral agents. With this objective, the antiviral activity in the aqueous extract of a mangrove plant Ceriops tagal in Penaeus monodon was evaluated. The Ceriops tagal aqueous extract (CTAE) was non-toxic to shrimps at 50 mg/ml when injected intramuscularly at a dosage of 10 μL/animal (0.5 mg/animal) and showed a protective effect against WSSV at 30 mg/ml when mixed with WSSV suspension at a 1:1 ratio. When the extract was administered along with the diet and the animals were challenged orally, there was a dose-dependent increase in survival, culminating in 100 % survival at a concentration of 500 mg/kg body weight/day. Neither hypertrophied nuclei nor the viral envelope protein VP28 could be demonstrated in surviving shrimps using histology and indirect immunofluorescence histochemistry (IIFH), respectively. To elucidate the mode of action, the temporal expression of WSSV genes and shrimp immune genes, including antimicrobial peptides, was attempted. None of the viral genes were found to be expressed in shrimps that were fed with the extract and challenged or in those that were administered CTAE-exposed WSSV. The overall results suggest that the aqueous extract from C. tagal can protect P. monodon from white spot syndrome virus infection.

  3. Bivalve Shell Horizons in Seafloor Pockmarks of the Last Glacial-interglacial Transition Suggest a Thousand Years of Methane Emissions in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Ambrose, W. G., Jr.; Panieri, G.; Schneider, A.; Plaza-Faverola, A. A.; Carroll, M.; Åström, E. K. L.; Locke, W. L.; Carroll, J.

    2015-12-01

    We studied discrete bivalve shell horizons, in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (ca. 1200 m water depth), western Svalbard (79° 00' N, 06° 55' W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, are dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp. were 20-30cm thick centered at 250-400cm depth in the cores. The carbon isotope composition of inorganic (δ13C from -13.02‰ to +2.364‰) and organic (δ13C from -29.283‰ to -21.33‰) shell material indicates that these taxa derived their energy primarily from endosymbiotic chemosynthetic bacteria feeding on methane. In addition, negative δ13C values for planktonic foraminifera (-6.7‰ to -3.1‰), micritic concretions identified as methane-derived authigenic carbonates and pyrite encrusted fossil worm tubes at the shell horizons indicate a sustained paleo-methane seep environment. Combining sedimentation rates with 14C ages for bivalve material from the shell horizons, we estimate the horizons persisted for about 1000 years between approximately 17,707 to 16,680 yrs. BP (corrected). The major seepage event over a 1000 -year time interval was most likely triggered by tectonic stress and the subsequent release of over-pressurized fluids.

  4. Bivalve shell horizons in seafloor pockmarks of the last glacial-interglacial transition: a thousand years of methane emissions in the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Ambrose, William G.; Panieri, Giuliana; Schneider, Andrea; Plaza-Faverola, Andreia; Carroll, Michael L.; Åström, Emmelie K. L.; Locke, William L.; Carroll, JoLynn

    2015-12-01

    We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (˜1200 m water depth) and western Svalbard (79°00' N, 06°55' W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20-30 cm thick and centered at 250-400 cm deep in the cores. The carbon isotope composition of inorganic (δ13C from -13.02‰ to +2.36‰) and organic (δ13C from -29.28‰ to -21.33‰) shell material and a two-end member mixing model indicate that these taxa derived between 8% and 43% of their nutrition from chemosynthetic bacteria. In addition, negative δ13C values for planktonic foraminifera (-6.7‰ to -3.1‰), concretions identified as methane-derived authigenic carbonates, and pyrite-encrusted fossil worm tubes at the shell horizons indicate a sustained paleo-methane seep environment. Combining sedimentation rates with 14C ages for bivalve material from the shell horizons, we estimate the horizons persisted for about 1000 years between approximately 17,707 and 16,680 years B.P. (corrected). The seepage event over a 1000 year time interval was most likely associated with regional stress-related faulting and the subsequent release of overpressurized fluids.

  5. An Innocent Giant

    PubMed Central

    Solanki, Lakhan Singh; Dhingra, Mandeep; Raghubanshi, Gunjan; Thami, Gurvinder Pal

    2014-01-01

    A cutaneous horn (cornu cutaneum) is a protrusion from the skin composed of a cornified material. It may be associated with a benign, premalignant, or malignant lesion at the base, masking numerous dermatoses. In a 24-year-old female, a giant cutaneous horn arising from a seborrheic keratosis located on the leg is presented. This case has been reported to emphasize that a giant cutaneous horn may also occur in young patients, even in photoprotected areas, and are not always associated with malignancy. PMID:25484426

  6. Sunspots and Giant-Cell Convection

    NASA Technical Reports Server (NTRS)

    Moore, Ron L.; Hathaway, David H.; Reichmann, Ed J.

    2000-01-01

    From analysis of Doppler velocity images from SOHO/MDI, Hathaway et al (2000, Solar Phys., in press) have found clear evidence for giant convection cells that fill the solar surface, have diameters 3 - 10 times that typical of supergranules, and have lifetimes approx. greater than 10 days. Analogous to the superposition of the granular convection on the supergranular convection, the approx. 30,000 km diameter supergranules are superposed on these still larger giant cells. Because the giant cells make up the large-scale end of a continuous power spectrum that peaks at the size scale of supergranules, it appears that the giant cells are made by the same mode of convection as the supergranules. This suggests that the giant cells are similar to supergranules, just longer-lived, larger in diameter, and deeper. Here we point out that the range of lengths of large bipolar sunspot groups is similar to the size range of giant cells. This, along with the long lives (weeks) of large sunspots, suggests that large sunspots sit in long-lived, deep downflows at the corners of giant cells, and that the distance from leader to follower sunspots in large bipolar groups is the distance from one giant-cell corner to the next. By this line of reasoning, an unusually large and strong downdraft might pull in both legs of a rising spot-group magnetic flux loop, resulting in the formation of a delta sunspot. This leads us to suggest that a large, strong giant-cell corner downdraft should be present at the birthplaces of large delta sunspots for some time (days to weeks) before the birth. Thus, early detection of such downdrafts by local helioscismology might provide an early warning for the formation of those active regions (large delta sunspot groups) that produce the Sun's most violent flares and coronal mass ejections. This work is supported by NASA's Office of Space Science through the Solar Physics Branch of its Sun-Earth Connection Program.

  7. The GIANT Encyclopedia of Science Activities for Children 3 to 6: More Than 600 Science Activities Written by Teachers for Teachers.

    ERIC Educational Resources Information Center

    Charner, Kathy, Ed.

    This book presents science activities developed by teachers for children ages 3-6 years old. The activities aim to develop science skills including communication, observation, estimation, measurement, cause and effect, investigation, and evaluation in children by using their curiosity as a staring point. Activities include age suggestions, address…

  8. Two New Long-period Giant Planets from the McDonald Observatory Planet Search and Two Stars with Long-period Radial Velocity Signals Related to Stellar Activity Cycles

    NASA Astrophysics Data System (ADS)

    Endl, Michael; Brugamyer, Erik J.; Cochran, William D.; MacQueen, Phillip J.; Robertson, Paul; Meschiari, Stefano; Ramirez, Ivan; Shetrone, Matthew; Gullikson, Kevin; Johnson, Marshall C.; Wittenmyer, Robert; Horner, Jonathan; Ciardi, David R.; Horch, Elliott; Simon, Attila E.; Howell, Steve B.; Everett, Mark; Caldwell, Caroline; Castanheira, Barbara G.

    2016-02-01

    We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 (ψ1 Dra B) by the McDonald Observatory planet search. The planet HD 95872b has a minimum mass of 4.6 {M}{{Jup}} and an orbital semimajor axis of 5.2 AU. The giant planet ψ1 Dra Bb has a minimum mass of 1.5 {M}{{Jup}} and an orbital semimajor axis of 4.4 AU. Both of these planets qualify as Jupiter analogs. These results are based on over one and a half decades of precise radial velocity (RV) measurements collected by our program using the McDonald Observatory Tull Coude spectrograph at the 2.7 m Harlan J. Smith Telescope. In the case of ψ1 Dra B we also detect a long-term nonlinear trend in our data that indicates the presence of an additional giant planet, similar to the Jupiter-Saturn pair. The primary of the binary star system, ψ1 Dra A, exhibits a very large amplitude RV variation due to another stellar companion. We detect this additional member using speckle imaging. We also report two cases—HD 10086 and HD 102870 (β Virginis)—of significant RV variation consistent with the presence of a planet, but that are probably caused by stellar activity, rather than reflexive Keplerian motion. These two cases stress the importance of monitoring the magnetic activity level of a target star, as long-term activity cycles can mimic the presence of a Jupiter-analog planet.

  9. Giant scrotal elephantiasis.

    PubMed

    Kuepper, Daniel

    2005-02-01

    How much can a man carry? Penoscrotal elephantiasis is a debilitating syndrome. This is a case report of a patient with giant genital elephantiasis secondary to long-standing lymphogranuloma venereum infection in Ethiopia. Complete surgical resection of the pathologic tissue and penile reconstruction was undertaken with good cosmetic and functional results.

  10. Electroluminescence of Giant Stretchability.

    PubMed

    Yang, Can Hui; Chen, Baohong; Zhou, Jinxiong; Chen, Yong Mei; Suo, Zhigang

    2016-06-01

    A new type of electroluminescent device achieves giant stretchability by integrating electronic and ionic components. The device uses phosphor powders as electroluminescent materials, and hydrogels as stretchable and transparent ionic conductors. Subject to cyclic voltage, the phosphor powders luminesce, but the ionic conductors do not electrolyze. The device produces constant luminance when stretched up to an area strain of 1500%.

  11. Types and Evolution of Gas Hydrate System along the Tectonically Active Zones of the Western Pacific: Nankai Trough vs. Eastern Margin of Japan Sea

    NASA Astrophysics Data System (ADS)

    Matsumoto, R.; Tomaru, H.; Takeuchi, L.; Hiruta, A.; Ishizaki, O.; Aoyama, C.; Machiyama, H.; Goto, T.

    2007-12-01

    are widely distributed throughout the area, while no double BSRs are observed. BSRs within gas chimneys are very strong and often exhibit pull-up structure. A number of piston corers have recovered chunks of massive gas hydrate from the mounds. ROV dives observed gas hydrates exposed atop the mounds. Furthermore, electric ocean floor survey has revealed that sediments below the pockmark-mound zones were not conductive. These lines of evidence suggest that the mounds are more-or-less composed of or at least contain significant amounts of methane. Sea-level fall during the last glacial, 120 m in Japan Sea, should have caused instability of gas hydrate, in particular, those within pockmarks. Pull-up structures within the chimney seem to support the model that the mounds are gas hydrate dome and the pockmark, probably a relic hydrate mound. Glacial sea level fall should have caused massive dissociation of subsurface methane hydrate as in case of the Nankai trough. However the methane from the dissociation of massive hydrate in the chimney should escape to seawater to form a crater-like depression pockmarks. Considering active venting, gigantic plumes, inferred violent venting and perhaps floating of massive gas hydrates, gas hydrate deposits are to be formed during warmer, high-sea level periods, and episodic dissociation and massive emission of methane to ocean/atmosphere system.

  12. Insights into the activity, formation and origin of seep systems on the seafloor in the SW Barents Sea

    NASA Astrophysics Data System (ADS)

    Mangelsdorf, Kai; Nickel, Julia C.; di Primio, Rolando; Kallmeyer, Jens; Horsfield, Brian; Stoddart, Daniel; Brunstad, Harald

    2014-05-01

    The southwestern Loppa High region, being part of the Barents Sea located in the north of Norway, is a promising area for oil and gas exploration since hydrocarbon discoveries have been made in this area in recent time. Additionally, surface features for hydrocarbon seepage, so called "cold seeps" have been detected on the seafloor, comprising extensive pockmark fields, carbonate crusts bearing areas and fault related gas flares. Leaking hydrocarbons are of specific interest since they are potential indicators for hydrocarbon reservoirs in the subsurface and the emitting hydrocarbons such as the greenhouse gas methane can have significant impact on the evolution of global warming when reaching the atmosphere. In this study cold seep systems like huge pockmark areas and carbonate crust sites from the SW Loppa High region were examined in detail, in order to determine the activity, formation and spatial distribution of the different seepage structures as well as the origin and timing of the seeping hydrocarbon fluids. The sample material comprising sediment cores from pockmarks, reference sites and carbonate crust areas as well as carbonate crust samples have been analyzed applying a combined biogeochemical and microbiological approach. In the carbonate crust area diagnostic biomarkers for the anaerobic oxidation of methane (AOM) were detected in the sediments as well as in the corresponding carbonate crusts. Their depth profiles show a distinct interval of higher concentrations, which points towards a shallow AOM zone in the investigated core. The biomarkers were also characterized by very negative carbon isotope signatures, indicating the involvement of the source microorganisms in the process of AOM. These data and active gas bubbling during sampling indicate the presence of methane at the carbonate crust site. In contrast in the pockmark areas active release of gas from the sediment could not be observed, neither in the gas measurement nor in the biogeochemical

  13. Ice Giant Exploration

    NASA Astrophysics Data System (ADS)

    Rymer, A. M.; Arridge, C. S.; Masters, A.; Turtle, E. P.; Simon, A. A.; Hofstadter, M. D.; Turrini, D.; Politi, R.

    2015-12-01

    The Ice Giants in our solar system, Uranus and Neptune, are fundamentally different from their Gas Giant siblings Jupiter and Saturn, from the different proportions of rock and ice to the configuration of their planetary magnetic fields. Kepler space telescope discoveries of exo-planets indicate that planets of this type are among the most ubiquitous universally and therefore a future mission to explore the nature of the Ice Giants in our own solar system will provide insights into the nature of extra-solar system objects in general. Uranus has the smallest self- luminosity of all the planets, potentially related to catastrophic events early in the planet's history, which also may explain Uranus' large obliquity. Uranus' atmosphere is subject to extreme seasonal forcing making it unique in the Solar System. Neptune is also unique in a number of ways, notably its large moon Triton which is likely a captured Kuiper Belt Object and one of only two moons in the solar system with a robustly collisional atmosphere. Similar to Uranus, the angle between the solar wind and the magnetic dipole axis is subject to large-amplitude variations on both diurnal and seasonal timescales, but peculiarly it has one of the quietest magnetospheres of the solar system, at least according to Voyager 2, the only spacecraft to encounter Neptune to date. A comprehensive mission, as advocated in the Decadal Survey, would provide enormous science return but is also challenging and expensive. In this presentation we will discuss mission scenarios and suggest how collaboration between disciplines and internationally can help us to pursue a mission that includes Ice Giant exploration.

  14. Giant cell arteritis

    PubMed Central

    Calvo-Romero, J

    2003-01-01

    Giant cell arteritis (GCA), temporal arteritis or Horton's arteritis, is a systemic vasculitis which involves large and medium sized vessels, especially the extracranial branches of the carotid arteries, in persons usually older than 50 years. Permanent visual loss, ischaemic strokes, and thoracic and abdominal aortic aneurysms are feared complications of GCA. The treatment consists of high dose steroids. Mortality, with a correct treatment, in patients with GCA seems to be similar that of controls. PMID:13679546

  15. Giant Cell Arteritis.

    PubMed

    Hoffman, Gary S

    2016-11-01

    This issue provides a clinical overview of giant cell arteritis, focusing on diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  16. Fatal canine distemper virus infection of giant pandas in China.

    PubMed

    Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

    2016-06-16

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species.

  17. Fatal canine distemper virus infection of giant pandas in China

    PubMed Central

    Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

    2016-01-01

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species. PMID:27310722

  18. SPOON-FEEDING GIANT STARS TO SUPERMASSIVE BLACK HOLES: EPISODIC MASS TRANSFER FROM EVOLVING STARS AND THEIR CONTRIBUTION TO THE QUIESCENT ACTIVITY OF GALACTIC NUCLEI

    SciTech Connect

    MacLeod, Morgan; Ramirez-Ruiz, Enrico; Grady, Sean; Guillochon, James

    2013-11-10

    Stars may be tidally disrupted if, in a single orbit, they are scattered too close to a supermassive black hole (SMBH). Tidal disruption events are thought to power luminous but short-lived accretion episodes that can light up otherwise quiescent SMBHs in transient flares. Here we explore a more gradual process of tidal stripping where stars approach the tidal disruption radius by stellar evolution while in an eccentric orbit. After the onset of mass transfer, these stars episodically transfer mass to the SMBH every pericenter passage, giving rise to low-level flares that repeat on the orbital timescale. Giant stars, in particular, will exhibit a runaway response to mass loss and 'spoon-feed' material to the black hole for tens to hundreds of orbital periods. In contrast to full tidal disruption events, the duty cycle of this feeding mode is of order unity for black holes M{sub bh} ∼> 10{sup 7} M{sub ☉}. This mode of quasi-steady SMBH feeding is competitive with indirect SMBH feeding through stellar winds, and spoon-fed giant stars may play a role in determining the quiescent luminosity of local SMBHs.

  19. [Distribution patterns of giant panda in Guanyinshan and Foping nature reserves].

    PubMed

    Cao, Qing; Zhu, Yun; Ruan, Ying-qin; Yong, Li-jun; Wang, Xiao-hong; Zhang, Wen-hui

    2009-09-01

    By using line transect method, the distribution patterns of giant panda population and its sympatric companion wildlife species in Foping and Guanyinshan nature reserves were investigated in October 2007 and April 2008, and the environmental factors affecting the spatial distribution of giant panda activity were analyzed. The giant panda population and its sympatric companion wildlife species in the two reserves had the similar distribution patterns, and the density and distribution range of giant panda were smaller in Guanyinshan than in Foping. Giant panda had two high-density distribution areas in Foping, but no activity trace in most parts of Guanyinshan. The activity trace of Budorcas taxicolor, Naemorhedus goral and Sus scrofa was more in Guanyinshan than in Foping. Anthropogenic interference might affect the distribution pattern of giant panda.

  20. Imaging Extrasolar Giant Planets

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.

    2016-10-01

    High-contrast adaptive optics (AO) imaging is a powerful technique to probe the architectures of planetary systems from the outside-in and survey the atmospheres of self-luminous giant planets. Direct imaging has rapidly matured over the past decade and especially the last few years with the advent of high-order AO systems, dedicated planet-finding instruments with specialized coronagraphs, and innovative observing and post-processing strategies to suppress speckle noise. This review summarizes recent progress in high-contrast imaging with particular emphasis on observational results, discoveries near and below the deuterium-burning limit, and a practical overview of large-scale surveys and dedicated instruments. I conclude with a statistical meta-analysis of deep imaging surveys in the literature. Based on observations of 384 unique and single young (≈5-300 Myr) stars spanning stellar masses between 0.1 and 3.0 M ⊙, the overall occurrence rate of 5-13 M Jup companions at orbital distances of 30-300 au is {0.6}-0.5+0.7 % assuming hot-start evolutionary models. The most massive giant planets regularly accessible to direct imaging are about as rare as hot Jupiters are around Sun-like stars. Dividing this sample into individual stellar mass bins does not reveal any statistically significant trend in planet frequency with host mass: giant planets are found around {2.8}-2.3+3.7 % of BA stars, <4.1% of FGK stars, and <3.9% of M dwarfs. Looking forward, extreme AO systems and the next generation of ground- and space-based telescopes with smaller inner working angles and deeper detection limits will increase the pace of discovery to ultimately map the demographics, composition, evolution, and origin of planets spanning a broad range of masses and ages.

  1. A Giant Urethral Calculus.

    PubMed

    Sigdel, G; Agarwal, A; Keshaw, B W

    2014-01-01

    Urethral calculi are rare forms of urolithiasis. Majority of the calculi are migratory from urinary bladder or upper urinary tract. Primary urethral calculi usually occur in presence of urethral stricture or diverticulum. In this article we report a case of a giant posterior urethral calculus measuring 7x3x2 cm in a 47 years old male. Patient presented with acute retention of urine which was preceded by burning micturition and dribbling of urine for one week. The calculus was pushed in to the bladder through the cystoscope and was removed by suprapubic cystolithotomy.

  2. The first-order giant neurons of the giant fiber system in the squid: electrophysiological and ultrastructural observations.

    PubMed

    Pozzo-Miller, L D; Moreira, J E; Llinás, R R

    1998-06-01

    The giant fiber system controlling mantle contraction used for jet propulsion in squid consists of two sets of three giant neurons organized in tandem. The somata of the 1st- and 2nd-order giant cells are located in the brain, while the perikarya of the 3rd-order giant cells are encountered in the stellate ganglia of the mantle. The somata and dendrites of one fused pair of 1st-order giant cells are thought to receive synaptic input from the eye, statocyst, skin proprioceptors, and supraesophageal lobes. To define the cellular properties for integration of such an extensive synaptic load, especially given its diversity, intracellular recordings and electron microscopic observations were performed on 1st-order giant cells in an isolated head preparation. Spontaneous bursts of action potentials and spikes evoked by extracellular stimulation of the brachial lobe were sensitive to the Na+ channel blocker TTX. Action potentials were also abolished by recording with microelectrodes containing the membrane impermeant, use dependent Na+ channel blocker QX-314. The small action potential amplitude and the abundant synaptic input imply that the spike initiation zone is remotely located from the recording site. The high spontaneous activity in the isolated head preparation, as well as the presence of synaptic junctions resembling inhibitory synapses, suggest; that afferent synapses on 1st-order giant neurons might represent the inhibitory control of the giant fiber system. The characterization of the electroresponsive properties of the 1st-order giant neurons will provide a description of the single cell integrative properties that trigger the rapid jet propulsion necessary for escape behavior in squid.

  3. Denosumab for the treatment of giant cell tumor of the bone.

    PubMed

    Brodowicz, Thomas; Hemetsberger, Margit; Windhager, Reinhard

    2015-01-01

    Giant cell tumor of bone is typically composed of neoplastic stromal cells and non-neoplastic osteoclastic giant cells. RANK-expressing osteoclastic giant cells are recruited by RANK ligand excreted by the stromal cells, and used by these neoplastic cells to create expansion space. Denosumab specifically binds to and inhibits RANK ligand, thereby eradicating osteoclastic giant cells from the tumor and thus reducing osteolytic activity. Clinical studies reported disease stabilization and clinical benefit in terms of reduced pain and analgesics use, avoided surgeries or surgeries with less morbid procedures. Adverse events observed in patients with giant cell tumor of bone were consistent with the known safety profile of denosumab with a very low incidence of hypocalcemia and osteonecrosis. Overall, denosumab was shown to suppress osteolytic activity and slow disease progression and is thus a treatment option for patients with giant cell tumor of bone.

  4. Giant papillary conjunctivitis.

    PubMed Central

    Donshik, P C

    1994-01-01

    Giant papillary conjunctivitis is a syndrome found frequently as a complication of contact lenses. Many variables can affect the onset and severity of the presenting signs and symptoms. Rigid gas permeable contact lenses appear to result in less severe signs and symptoms, with a longer time before the development of giant papillary conjunctivitis. Nonionic, low-water-content soft contact lenses tend to produce less severe signs and symptoms than ionic, low-water-content soft contact lenses. Enzymatic treatment appears to lessen the severity of signs and symptoms. The association of an allergy appears to play a role in the onset of the severity of the signs and symptoms but does not appear to affect the final ability of the individual to wear contact lenses. Using multiple treatment options, such as changing the polymer to a glyceryl methyl methacrylate or a rigid lens, or utilizing a soft lens on a frequent-replacement basis, can result in a success rate of over 90%. In individuals who still have a return of symptoms, the use of topical mast cell stabilizers or a nonsteroidal anti-inflammatory drug as an adjunctive therapy offers the added possibility of keeping these patients in contact lenses. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 11 A FIGURE 11 B FIGURE 11 C FIGURE 11 D PMID:7886881

  5. Giant extragenital Bowen's disease.

    PubMed

    Bakardzhiev, Ilko; Chokoeva, Anastasiya Atanasova; Tchernev, Georgi

    2015-12-01

    Giant extragenital forms of Morbus Bowen are extremely rare. The already described cases in the word literature are most commonly with periungual localization, as well as located on the foot and neck area. The clinical manifestation is presented most commonly by non-specific erythematous to erythematous-squamous plaques or papules, which is confusing to the clinician. From the pathogenic point of view, it is important to be confirmed or rejected the presence of human papilloma viruses (HPVs) in each case of affected patient, as this information is mandatory in respect to the adequate selection of the subsequent regimen. If HPVs are detected, systemic antiviral therapy could be initiated to reduce the size of the lesions before subsequent surgical eradication. A postoperative prevention through vaccination could be also considered additionally. In cases of HPV-negative giant extragenital forms of Morbus Bowen (as in the described patient), the focus should be on local immunomodulation by substances such as imiquimod, which reduce the size of the lesions, thereby creating optimal opportunities for their future surgical eradication. Other possible options described in the literature include topical application of 5-fluorouracil, photodynamic therapy, cryotherapy, and laser therapy (carbon dioxide laser). The choice of the most appropriate regimen should have been an individual decision of the clinician, considering also the location and the extent of the lesion.

  6. Gas Giants Form Quickly

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas.

    Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years.

    The scientists came to this conclusion after searching for traces of gas around 15 different sun-like stars, most with ages ranging from 3 million to 30 million years. With the help of Spitzer's Infrared Spectrometer instrument, they were able to search for relatively warm gas in the inner regions of these star systems, an area comparable to the zone between Earth and Jupiter in our own solar system. They also used ground-based radio telescopes to search for cooler gas in the outer regions of these systems, an area comparable to the zone around Saturn and beyond.

  7. Giant Intradiverticular Bladder Tumor

    PubMed Central

    Noh, Mohamad Syafeeq Faeez Md; Aziz, Ahmad Fuad Abdul; Ghani, Khairul Asri Mohd; Siang, Christopher Lee Kheng; Yunus, Rosna; Yusof, Mubarak Mohd

    2017-01-01

    Patient: Male, 74 Final Diagnosis: Giant intradiverticular bladder tumor with metastasis Symptoms: Hematuria Medication:— Clinical Procedure: — Specialty: Urology Objective: Rare disease Background: Intradiverticular bladder tumors are rare. This renders diagnosis of an intradiverticular bladder tumor difficult. Imaging plays a vital role in achieving the diagnosis, and subsequently staging of the disease. Case Report: A 74-year-old male presented to our center with a few months history of constitutional symptoms. Upon further history, he reported hematuria two months prior to presentation, which stopped temporarily, only to recur a few days prior to coming to the hospital. The patient admitted to having lower urinary tract symptoms. However, there was no dysuria, no sandy urine, and no fever. Palpation of his abdomen revealed a vague mass at the suprapubic region, which was non tender. In view of his history and the clinical examination findings, an ultrasound of the abdomen and computed tomography (CT) was arranged. These investigations revealed a giant tumor that seemed to be arising from a bladder diverticulum, with a mass effect and hydronephrosis. He later underwent operative intervention. Conclusions: Intradiverticular bladder tumors may present a challenge to the treating physician in an atypical presentation; thus requiring a high index of suspicion and knowledge of tumor pathophysiology. As illustrated in our case, CT with its wide availability and multiplanar imaging capabilities offers a useful means for diagnosis, disease staging, operative planning, and follow-up. PMID:28246375

  8. HHV-6A in syncytial giant-cell hepatitis.

    PubMed

    Potenza, Leonardo; Luppi, Mario; Barozzi, Patrizia; Rossi, Giulio; Cocchi, Stefania; Codeluppi, Mauro; Pecorari, Monica; Masetti, Michele; Di Benedetto, Fabrizio; Gennari, William; Portolani, Marinella; Gerunda, Giorgio Enrico; Lazzarotto, Tiziana; Landini, Maria Paola; Schulz, Thomas F; Torelli, Giuseppe; Guaraldi, Giovanni

    2008-08-07

    Syncytial giant-cell hepatitis is a rare but severe form of hepatitis that is associated with autoimmune diseases, drug reactions, and viral infections. We used serologic, molecular, and immunohistochemical methods to search for an infectious cause in a case of syncytial giant-cell hepatitis that developed in a liver-transplant recipient who had latent infection with variant B of human herpesvirus 6 (HHV-6B) and who had received the organ from a donor with variant A latent infection (HHV-6A). At the onset of the disease, the detection of HHV-6A (but not HHV-6B) DNA in plasma, in affected liver tissue, and in single micromanipulated syncytial giant cells with the use of two different polymerase-chain-reaction (PCR) assays indicated the presence of active HHV-6A infection in the patient. Expression of the HHV-6A-specific early protein, p41/38, but not of the HHV-6B-specific late protein, p101, was demonstrated only in liver syncytial giant cells in the absence of other infectious pathogens. The same markers of HHV-6A active infection were documented in serial follow-up samples from the patient and disappeared only at the resolution of syncytial giant-cell hepatitis. Neither HHV-6B DNA nor late protein was identified in the same follow-up samples from the patient. Thus, HHV-6A may be a cause of syncytial giant-cell hepatitis.

  9. Reinflating Giant Planets

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-01-01

    Two new, large gas-giant exoplanets have been discovered orbiting close to their host stars. A recent study examining these planets and others like them may help us to better understand what happens to close-in hot Jupiters as their host stars reach the end of their main-sequence lives.OversizedGiantsUnbinned transit light curves for HAT-P-65b. [Adapted from Hartman et al. 2016]The discovery of HAT-P-65b and HAT-P-66b, two new transiting hot Jupiters, is intriguing. These planets have periods of just under 3 days and masses of roughly 0.5 and 0.8 times that of Jupiter, but their sizes are whats really interesting: they have inflated radii of 1.89 and 1.59 times that of Jupiter.These two planets, discovered using the Hungarian-made Automated Telescope Network (HATNet) in Arizona and Hawaii, mark the latest in an ever-growing sample of gas-giant exoplanets with radii larger than expected based on theoretical planetary structure models.What causes this discrepancy? Did the planets just fail to contract to the expected size when they were initially formed, or were they reinflated later in their lifetimes? If the latter, how? These are questions that scientists are only now starting to be able to address using statistics of the sample of close-in, transiting planets.Unbinned transit light curves for HAT-P-66b. [Hartman et al. 2016]Exploring Other PlanetsLed by Joel Hartman (Princeton University), the team that discovered HAT-P-65b and HAT-P-66b has examined these planets observed parameters and those of dozens of other known close-in, transiting exoplanets discovered with a variety of transiting exoplanet missions: HAT, WASP, Kepler, TrES, and KELT. Hartman and collaborators used this sample to draw conclusions about what causes some of these planets to have such large radii.The team found that there is a statistically significant correlation between the radii of close-in giant planets and the fractional ages of their host stars (i.e., the stars age divided by its full

  10. Allometry indicates giant eyes of giant squid are not exceptional

    PubMed Central

    2013-01-01

    Background The eyes of giant and colossal squid are among the largest eyes in the history of life. It was recently proposed that sperm whale predation is the main driver of eye size evolution in giant squid, on the basis of an optical model that suggested optimal performance in detecting large luminous visual targets such as whales in the deep sea. However, it is poorly understood how the eye size of giant and colossal squid compares to that of other aquatic organisms when scaling effects are considered. Results We performed a large-scale comparative study that included 87 squid species and 237 species of acanthomorph fish. While squid have larger eyes than most acanthomorphs, a comparison of relative eye size among squid suggests that giant and colossal squid do not have unusually large eyes. After revising constants used in a previous model we found that large eyes perform equally well in detecting point targets and large luminous targets in the deep sea. Conclusions The eyes of giant and colossal squid do not appear exceptionally large when allometric effects are considered. It is probable that the giant eyes of giant squid result from a phylogenetically conserved developmental pattern manifested in very large animals. Whatever the cause of large eyes, they appear to have several advantages for vision in the reduced light of the deep mesopelagic zone. PMID:23418818

  11. [Giant esophageal fibrovascular polyp].

    PubMed

    Palacios, Fernando; Contardo, Carlos; Guevara, Jorge; Vera, Augusto; Aguilar, Luis; Huamán, Manuel; Palomino, Américo; Yabar, Alejandro

    2003-01-01

    Fibrovascular polyps are extremely rare benign neoplasias of the esophagus, which usually originate in the lower cricoid area. They do not produce any discomfort in the patient for a long time, however it may make itself evident by the patient's regurgitation of the polyp, producing asphyxia or, more frequently, dysphagia. The case of a 58 year old male patient is presented herein, with a 9 month record of dysphagia, weight loss and intermittent melena. The barium x-ray showed a distended esophagus, with a tumor running from the upper esophageal sphincter to the cardia. The endoscopy confirmed the presence of a pediculated tumor, implanted in the cervical esophagus. Surgeons suspected the potential malignancy of the tumor and performed a transhiatal esophagectomy. The final pathologic diagnosis was giant fibrovascular esophageal polyp.

  12. Giant resonances: Progress, new directions, new challenges

    SciTech Connect

    Bertrand, J.R.; Beene, J.R.

    1989-01-01

    A review of some recent developments in the field of giant multipole resonances is presented. Particular emphasis is placed on directions that the authors feel will be followed in this field during the next several years. In particular, the use of high-energy heavy ions to excite the giant resonances is shown to provide exciting new capabilities for giant resonance studies. Among subjects covered are: Coulomb excitation of giant resonances, photon decay of giant resonances, the recent controversy over the identity of the giant monopole resonance, the most recent value for incompressibility of nuclear matter from analysis of giant monopole data, the isospin character of the 63 A/sup /minus/1/3/ GQR, agreement between (e,e/prime/) and (hadron, hadron/prime/) excitation of the giant quadrupole resonance, prospects for multiphonon giant resonance observation, and isolation of the isovector giant quadrupole resonance. 55 refs., 23 figs., 4 tabs.

  13. Giant Hedge-Hogs: Spikes on Giant Gravitons

    SciTech Connect

    Sadri, D

    2004-01-28

    We consider giant gravitons on the maximally supersymmetric plane-wave background of type IIB string theory. Fixing the light-cone gauge, we work out the low energy effective light-cone Hamiltonian of the three-sphere giant graviton. At first order, this is a U(1) gauge theory on R x S{sup 3}. We place sources in this effective gauge theory. Although non-vanishing net electric charge configurations are disallowed by Gauss' law, electric dipoles can be formed. From the string theory point of view these dipoles can be understood as open strings piercing the three-sphere, generalizing the usual BIons to the giant gravitons, BIGGons. Our results can be used to give a two dimensional (worldsheet) description of giant gravitons, similar to Polchinski's description for the usual D-branes, in agreement with the discussions of hep-th/0204196.

  14. A giant Ordovician anomalocaridid.

    PubMed

    Van Roy, Peter; Briggs, Derek E G

    2011-05-26

    Anomalocaridids, giant lightly sclerotized invertebrate predators, occur in a number of exceptionally preserved early and middle Cambrian (542-501 million years ago) biotas and have come to symbolize the unfamiliar morphologies displayed by stem organisms in faunas of the Burgess Shale type. They are characterized by a pair of anterior, segmented appendages, a circlet of plates around the mouth, and an elongate segmented trunk lacking true tergites with a pair of flexible lateral lobes per segment. Disarticulated body parts, such as the anterior appendages and oral circlet, had been assigned to a range of taxonomic groups--but the discovery of complete specimens from the middle Cambrian Burgess Shale showed that these disparate elements all belong to a single kind of animal. Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods. The anomalocaridids were the largest animals in Cambrian communities. The youngest unequivocal examples occur in the middle Cambrian Marjum Formation of Utah but an arthropod retaining some anomalocaridid characteristics is present in the Devonian of Germany. Here we report the post-Cambrian occurrence of anomalocaridids, from the Early Ordovician (488-472 million years ago) Fezouata Biota in southeastern Morocco, including specimens larger than any in Cambrian biotas. These giant animals were an important element of some marine communities for about 30 million years longer than previously realized. The Moroccan specimens confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments; these blades probably functioned as gills.

  15. Ra5G, a homologue of Ra5 in giant ragweed pollen: isolation, HLA-DR-associated activity and amino acid sequence.

    PubMed

    Goodfriend, L; Choudhury, A M; Klapper, D G; Coulter, K M; Dorval, G; Del Carpio, J; Osterland, C K

    1985-08-01

    Recent studies [Marsh et al. (1982) J. exp. Med. 155, 1439-1451; Coulter (1983) M.Sc. thesis, McGill University, Montreal, Canada; Coulter et al. (1983) in Genetic and Environmental Factors in Clinical Allergy (Edited by Marsh D.G., Blumenthal M.N. and Santilli J., Jr), University of Minnesota Press, Minneapolis, MN] have shown a highly significant association between HLA-Dw2/DR2 and host sensitivity to the 5000-D, 4-disulfide bonded protein Ra5S of short ragweed pollen. To extend these findings, we isolated Ra5G, an Ra5S-like protein, from giant ragweed pollen by gel and ion-exchange chromatography. The protein was homogeneous by polyacrylamide gel electrophoresis (pH 4.3), reverse-phase high-performance liquid chromatography, and antigenic assays. Its mol. wt and amino acid composition (including 8 half-cystine residues) were closely similar to Ra5S, but the two proteins had little or no antigenic or allergenic cross-reactivity. In a study of 200 ragweed-sensitive individuals, host sensitivity simultaneously to Ra5G and Ra5S was significantly associated with the DR2 allele. The amino acid sequence of Ra5G was determined and showed close homology with Ra5S. The potential function of a highly homologous decapeptidyl sequence stretch is discussed in relation to Ir gene control of immune response to the 2 proteins.

  16. Pharma giants swap research programs.

    PubMed

    2014-07-01

    Pharmaceutical giants Novartis and GlaxoSmithKline (GSK) agreed in late April to swap some assets, with Novartis handing off its vaccine business to GSK and getting most of the British company's cancer portfolio in return.

  17. Theories of Giant Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of planetary formation, with emphasis on giant planets, is presented. The most detailed models are based upon observations of our own Solar System and of young stars and their environments. While these models predict that rocky planets should form around most single stars, the frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Most models for extrasolar giant planets suggest that they formed as did Jupiter and Saturn (in nearly circular orbits, far enough from the star that ice could), and subsequently migrated to their current positions, although some models suggest in situ formation.

  18. Lichens On Galapagos Giant Tortoises.

    PubMed

    Hendrickson, J R; Weber, W A

    1964-06-19

    The association of Physcia picta with the giant Galdpagos tortoise is believed to be the first reported occurrence of lichens on land animals. The habitat is restricted to specific sites on the carapace of male tortoises.

  19. Landscape of the lost giants

    NASA Astrophysics Data System (ADS)

    2013-09-01

    The Pleistocene megafauna extinction erased a group of remarkable animals. Whether humans had a prominent role in the extinction remains controversial, but it is emerging that the disappearance of the giants has markedly affected the environment.

  20. Atmospheres of Extrasolar Giant Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2006-01-01

    The next decade will almost certainly see the direct imaging of extrasolar giant planets around nearby stars. Unlike purely radial velocity detections, direct imaging will open the door to characterizing the atmosphere and interiors of extrasola planets and ultimately provide clues on their formation and evolution through time. This process has already begun for the transiting planets, placing new constraints on their atmospheric structure, composition, and evolution. Indeed the key to understanding giant planet detectability, interpreting spectra, and constraining effective temperature and hence evolution-is the atmosphere. I will review the universe of extrasolar giant planet models, focusing on what we have already learned from modeling and what we will likely be able to learn from the first generation of direct detection data. In addition to these theoretical considerations, I will review the observations and interpretation of the - transiting hot Jupiters. These objects provide a test of our ability to model exotic atmospheres and challenge our current understanding of giant planet evolution.

  1. Giants in the Local Region

    NASA Astrophysics Data System (ADS)

    Luck, R. Earle; Heiter, Ulrike

    2007-06-01

    We present parameter and abundance data for a sample of 298 nearby giants. The spectroscopic data for this work have a resolution of R~60,000, S/N>150, and spectral coverage from 475 to 685 nm. Overall trends in the Z>10 abundances are dominated by Galactic chemical evolution, while the light-element abundances are influenced by stellar evolution, as well as Galactic evolution. We find several super-Li stars in our sample and confirm that Li abundances in the first giant branch are related to mixing depths. Once astration of lithium on the main sequence along with the overall range of main-sequence lithium abundances are taken into account, the lithium abundances of the giants are not dramatically at odds with the predictions of standard stellar evolution. We find the giants to be carbon-diluted in accord with standard stellar evolution and that the carbon and oxygen abundances determined for the local giants are consistent with those found in local field dwarfs. We find that there is evidence for systematic carbon variations in the red giant clump in the sense that the blue side of the clump is carbon-poor (more diluted) than the red side.

  2. The Giant Magnetocaloric Effect

    NASA Astrophysics Data System (ADS)

    Pecharsky, Vitalij K.

    1998-03-01

    Since the discovery of the magnetocaloric effect in pure iron by E.Warburg in 1881, it has been measured experimentally on many magnetic metals and compounds. The majority of the materials studied order magnetically undergoing a second order phase transformation. The magnetocaloric effect, typically peaking near the Curie or the Néel temperature, generally ranges from 0.5 to 2 K (in terms of adiabatic temperature change) or at 1 to 4 J/kg K (in terms of isothermal magnetic entropy change) per 1 T magnetic field change. The giant magnetocaloric effect recently discovered in Gd_5(Si_xGe_1-x)4 alloys, where x <= 0.5, is associated with a first order magnetic phase transition and it reaches values of 3 to 4 K and 6 to 10 J/kg K per 1 T field change, respectively. The refrigerant capacity, which is the measure of how much heat can be transferred from a cold to a hot reservoir in one ideal thermodynamic cycle, is larger than that of the best second order phase transition materials by 25 to 100%. When the Gd_5(Si_xGe_1-x)4 alloys are compared with other known materials, which show first order magnetic phase transition, such as Dy, Ho, Er, HoCo_2, NdMn_2Si_2, Fe_0.49Rh_0.51, and (Hf_0.83Ta_0.17)Fe_2+x, only Fe_0.49Rh_0.51 has comparable magnetocaloric properties. However, the first order magnetic phase transition in Fe_0.49Rh_0.51 is irreversible, and the magnetocaloric effect disappears after one magnetizing/demagnetizing cycle. A study of the crystal structure, thermodynamics, and magnetism of the Gd_5(Si_xGe_1-x)4 alloys, where 0 <= x <= 1 allowed us to obtain a qualitative understanding of the basic relations between the composition, the crystal structure, and the change in thermodynamics and magnetocaloric properties, which occur in the Gd_5(Si_xGe_1-x)4 system, and which brings about the giant magnetocaloric effect when x <= 0.5.

  3. The Giant Planet Satellite Exospheres

    NASA Astrophysics Data System (ADS)

    McGrath, M. A.

    2014-12-01

    Exospheres are relatively common in the outer solar system among the moons of the gas giant planets. They span the range from very tenuous, surface-bounded exospheres (e.g., Rhea, Dione) to quite robust exospheres with exobase above the surface (e.g., Io, Triton), and include many intermediate cases (e.g., Europa, Ganymede, Enceladus). The exospheres of these moons exhibit an interesting variety of sources, from surface sputtering, to frost sublimation, to active plumes, and also well illustrate another common characteristic of the outer planet satellite exospheres, namely, that the primary species often exists both as a gas in atmosphere, and a condensate (frost or ice) on the surface. As described by Yelle et al. (1995) for Triton, "The interchange of matter between gas and solid phases on these bodies has profound effects on the physical state of the surface and the structure of the atmosphere." A brief overview of the exospheres of the outer planet satellites will be presented, including an inter-comparison of these satellites exospheres with each other, and with the exospheres of the Moon and Mercury.

  4. The Giant Planet Satellite Exospheres

    NASA Technical Reports Server (NTRS)

    McGrath, Melissa A.

    2014-01-01

    Exospheres are relatively common in the outer solar system among the moons of the gas giant planets. They span the range from very tenuous, surface-bounded exospheres (e.g., Rhea, Dione) to quite robust exospheres with exobase above the surface (e.g., lo, Triton), and include many intermediate cases (e.g., Europa, Ganymede, Enceladus). The exospheres of these moons exhibit an interesting variety of sources, from surface sputtering, to frost sublimation, to active plumes, and also well illustrate another common characteristic of the outer planet satellite exospheres, namely, that the primary species often exists both as a gas in atmosphere, and a condensate (frost or ice) on the surface. As described by Yelle et al. (1995) for Triton, "The interchange of matter between gas and solid phases on these bodies has profound effects on the physical state of the surface and the structure of the atmosphere." A brief overview of the exospheres of the outer planet satellites will be presented, including an inter-comparison of these satellites exospheres with each other, and with the exospheres of the Moon and Mercury.

  5. A unique advantage for giant eyes in giant squid.

    PubMed

    Nilsson, Dan-Eric; Warrant, Eric J; Johnsen, Sönke; Hanlon, Roger; Shashar, Nadav

    2012-04-24

    Giant and colossal deep-sea squid (Architeuthis and Mesonychoteuthis) have the largest eyes in the animal kingdom [1, 2], but there is no explanation for why they would need eyes that are nearly three times the diameter of those of any other extant animal. Here we develop a theory for visual detection in pelagic habitats, which predicts that such giant eyes are unlikely to evolve for detecting mates or prey at long distance but are instead uniquely suited for detecting very large predators, such as sperm whales. We also provide photographic documentation of an eyeball of about 27 cm with a 9 cm pupil in a giant squid, and we predict that, below 600 m depth, it would allow detection of sperm whales at distances exceeding 120 m. With this long range of vision, giant squid get an early warning of approaching sperm whales. Because the sonar range of sperm whales exceeds 120 m [3-5], we hypothesize that a well-prepared and powerful evasive response to hunting sperm whales may have driven the evolution of huge dimensions in both eyes and bodies of giant and colossal squid. Our theory also provides insights into the vision of Mesozoic ichthyosaurs with unusually large eyes.

  6. Formation of the giant planets

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2006-01-01

    The observed properties of giant planets, models of their evolution and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our Solar System contain considerable quantities of hydrogen and helium, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our Solar System, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory .experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions

  7. Dietary resources shape the adaptive changes of cyanide detoxification function in giant panda (Ailuropoda melanoleuca).

    PubMed

    Huang, He; Yie, Shangmian; Liu, Yuliang; Wang, Chengdong; Cai, Zhigang; Zhang, Wenping; Lan, Jingchao; Huang, Xiangming; Luo, Li; Cai, Kailai; Hou, Rong; Zhang, Zhihe

    2016-10-05

    The functional adaptive changes in cyanide detoxification in giant panda appear to be response to dietary transition from typical carnivore to herbivorous bear. We tested the absorption of cyanide contained in bamboo/bamboo shoots with a feeding trial in 20 adult giant pandas. We determined total cyanide content in bamboo shoots and giant panda's feces, levels of urinary thiocyanate and tissue rhodanese activity using color reactions with a spectrophotometer. Rhodanese expression in liver and kidney at transcription and translation levels were measured using real-time RT-PCR and immunohistochemistry, respectively. We compared differences of rhodanese activity and gene expressions among giant panda, rabbit (herbivore) and cat (carnivore), and between newborn and adult giant pandas. Bamboo shoots contained 3.2 mg/kg of cyanide and giant pandas absorbed more than 65% of cyanide. However, approximately 80% of absorbed cyanide was metabolized to less toxic thiocyanate that was discharged in urine. Rhodanese expression and activity in liver and kidney of giant panda were significantly higher than in cat, but lower than in rabbit (all P < 0.05). Levels in adult pandas were higher than that in newborn cub. Phylogenetic analysis of both nucleotide and amino acid sequences of the rhodanese gene supported a closer relationship of giant panda with carnivores than with herbivores.

  8. Dietary resources shape the adaptive changes of cyanide detoxification function in giant panda (Ailuropoda melanoleuca)

    PubMed Central

    Huang, He; Yie, Shangmian; Liu, Yuliang; Wang, Chengdong; Cai, Zhigang; Zhang, Wenping; Lan, Jingchao; Huang, Xiangming; Luo, Li; Cai, Kailai; Hou, Rong; Zhang, Zhihe

    2016-01-01

    The functional adaptive changes in cyanide detoxification in giant panda appear to be response to dietary transition from typical carnivore to herbivorous bear. We tested the absorption of cyanide contained in bamboo/bamboo shoots with a feeding trial in 20 adult giant pandas. We determined total cyanide content in bamboo shoots and giant panda’s feces, levels of urinary thiocyanate and tissue rhodanese activity using color reactions with a spectrophotometer. Rhodanese expression in liver and kidney at transcription and translation levels were measured using real-time RT-PCR and immunohistochemistry, respectively. We compared differences of rhodanese activity and gene expressions among giant panda, rabbit (herbivore) and cat (carnivore), and between newborn and adult giant pandas. Bamboo shoots contained 3.2 mg/kg of cyanide and giant pandas absorbed more than 65% of cyanide. However, approximately 80% of absorbed cyanide was metabolized to less toxic thiocyanate that was discharged in urine. Rhodanese expression and activity in liver and kidney of giant panda were significantly higher than in cat, but lower than in rabbit (all P < 0.05). Levels in adult pandas were higher than that in newborn cub. Phylogenetic analysis of both nucleotide and amino acid sequences of the rhodanese gene supported a closer relationship of giant panda with carnivores than with herbivores. PMID:27703267

  9. Effects of hot-water extract of banana (Musa acuminata) fruit's peel on the antibacterial activity, and anti-hypothermal stress, immune responses and disease resistance of the giant freshwater prawn, Macrobrachium rosenbegii.

    PubMed

    Rattanavichai, Wutti; Cheng, Winton

    2014-08-01

    The hot-extracts isolated from fruit's peel of banana, Musa acuminata, was evaluated on the antibacterial activity to pathogens from aquatic animals, and immunostimulating potential, disease resistance and anti-hypothermal stress in giant freshwater prawn, Macrobrachium rosenbergii through injection administration. The banana peel extract (BPE) showed good activity against 1 Gram-positive and 3 Gram-negative pathogens, including Lactococcus garvieae, Photobacteria damsella, Vibrio alginolyticus and Vibrio parahemolyticus especially in prawn pathogen of L. garvieae strain, which were carried out by a disk diffusion method. Prawn received BPE via injection administration at 1-6 μg (g prawn)(-1) significantly increased total haemocyte count (THC), hyaline cell (HC), granular cell (GC), phenoloxidase (PO) activity and phagocytic activity against L. garvieae from 3 to 6 days, and significantly increased clearance efficiency against L. garvieae and a significantly decreased coagulation time of prawn from 1 to 6 days. Prawn injected with BPE at 6.0 μg (g prawn)(-1) for 6 days showed significantly increased superoxide dismutase (SOD) activity, but significantly decreased respiratory bursts (RBs) of per haemocyte. Survival rates of M. rosenbergii injected with BPE at concentrations of 1, 3 and 6 μg (g prawn)(-1) were significantly higher than those injected with saline control after challenge with L. garvieae for 4-6 days, and the respective relative survival percentages of prawn were 28.6%, 38.1%, and 47.8%, respectively at 6 days. The sublethal time of prawns that had received saline and BPE at 1, 3 and 6 μg (g prawn)(-1) for 6 days and then were transferred from 28 °C to 14 °C were 69.4, 79.8, 83.6, and 90.2 h, respectively. It was concluded that the BPE can be used as the bacteriostat, and immunostimulant and physiological regulator for prawn through injection administration to enhance immunity, physiological responses, and resistance against L. garvieae.

  10. Open questions about giant viruses.

    PubMed

    Claverie, Jean-Michel; Abergel, Chantal

    2013-01-01

    The recent discovery of giant viruses exhibiting double-stranded DNA genomes larger than a million base pairs, encoding more than a thousand proteins and packed in near micron-sized icosahedral particles, opened a new and unexpected chapter in virology. As of today, these giant viruses and their closest relatives of lesser dimensions infect unicellular eukaryotes found in aquatic environments, but belonging to a wide diversity of early branching phyla. This broad phylogenetic distribution of hosts is consistent with the hypothesis that giant viruses originated prior to the radiation of the eukaryotic domain and/or might have been involved in the partition of nuclear versus cytoplasmic functions in ancestral cells. The distinctive features of the known giant viruses, in particular the recurrent presence of components of the translation apparatus in their proteome, raise a number of fundamental questions about their origin, their mode of evolution, and the relationship they may entertain with other dsDNA viruses, the genome size of which exhibits the widest distribution among all biological entities, from less than 5 kb to more than 1.25 Mb (a ratio of 1:250). At a more conceptual level, the convergence between the discovery of increasingly reduced parasitic cellular organisms and that of giant viruses exhibiting a widening array of cellular-like functions may ultimately abolish the historical discontinuity between the viral and the cellular world.

  11. Giant Magellan Telescope: overview

    NASA Astrophysics Data System (ADS)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  12. Light induces changes in activities of Na+/K+-ATPase, H+/K+-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam, Tridacna squamosa

    PubMed Central

    Ip, Yuen K.; Ching, Biyun; Hiong, Kum C.; Choo, Celine Y. L.; Boo, Mel V.; Wong, Wai P.; Chew, Shit F.

    2015-01-01

    The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control), on enzymatic activities of transporters involved in the transport of NH+4 or H+, and activities of enzymes involved in converting NH+4 to glutamate/glutamine in inner mantle, outer mantle, and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH+4 in substitution for K+ to activate Na+/K+-ATPase (NKA), manifested as a significant increase in the Na+/NH+4-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H+ released from CaCO3 deposition could react with NH3 to form NH+4 in the extrapallial fluid, and NH+4 could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH+4 and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM)-sensitive-V-H+-ATPase (VATPase) in the inner mantle, and significant increases in the Na+/K+-activated-NKA, H+/NH+4-activated-H+/K+-ATPase, and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na+ homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH+4 from the environment. This is the first report on light having direct enhancing effects on activities of certain transporters

  13. Polymyalgia Rheumatica and Giant Cell Arteritis

    MedlinePlus

    ... Clinical Trial Journal Articles Polymyalgia Rheumatica and Giant Cell Arteritis May 2016 Questions and Answers about Polymyalgia Rheumatica and Giant Cell Arteritis This publication contains general information about polymyalgia ...

  14. The Lushan earthquake and the giant panda: impacts and conservation.

    PubMed

    Zhang, Zejun; Yuan, Shibin; Qi, Dunwu; Zhang, Mingchun

    2014-06-01

    Earthquakes not only result in a great loss of human life and property, but also have profound effects on the Earth's biodiversity. The Lushan earthquake occurred on 20 Apr 2013, with a magnitude of 7.0 and an intensity of 9.0 degrees. A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined. Making use of research on the Wenchuan earthquake (with a magnitude of 8.0), which occurred approximately 5 years ago, we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat. An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death. In addition, an earthquake can damage conservation facilities for pandas, and result in further habitat fragmentation and degradation. However, from a historical point of view, the impacts of human activities on giant pandas and their habitat may, in fact, far outweigh those of natural disasters such as earthquakes. Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas, not those of humans.

  15. Giant lobelias exemplify convergent evolution

    PubMed Central

    2010-01-01

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution. PMID:20074322

  16. Atmospheres of Extrasolar Giant Planets

    NASA Astrophysics Data System (ADS)

    Marley, M. S.; Fortney, J.; Seager, S.; Barman, T.

    The key to understanding an extrasolar giant planet's spectrum - and hence its detectability and evolution - lies with its atmosphere. Now that direct observations of thermal emission from extrasolar giant planets (EGPs) are in hand, atmosphere models can be used to constrain atmospheric composition, thermal structure, and ultimately the formation and evolution of detected planets. We review the important physical processes that influence the atmospheric structure and evolution of EGPs and consider what has already been learned from the first generation of observations and modeling. We pay particular attention to the roles of cloud structure, metallicity, and atmospheric chemistry in affecting detectable properties through Spitzer Space Telescope observations of the transiting giant planets. Our review stresses the uncertainties that ultimately limit our ability to interpret EGP observations. Finally we will conclude with a look to the future as characterization of multiple individual planets in a single stellar system leads to the study of comparative planetary architectures.

  17. CMB lensing and giant rings

    SciTech Connect

    Rathaus, Ben; Itzhaki, Nissan E-mail: ben.rathaus@gmail.com

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  18. Structure of giant muscle proteins

    PubMed Central

    Meyer, Logan C.; Wright, Nathan T.

    2013-01-01

    Giant muscle proteins (e.g., titin, nebulin, and obscurin) play a seminal role in muscle elasticity, stretch response, and sarcomeric organization. Each giant protein consists of multiple tandem structural domains, usually arranged in a modular fashion spanning 500 kDa to 4 MDa. Although many of the domains are similar in structure, subtle differences create a unique function of each domain. Recent high and low resolution structural and dynamic studies now suggest more nuanced overall protein structures than previously realized. These findings show that atomic structure, interactions between tandem domains, and intrasarcomeric environment all influence the shape, motion, and therefore function of giant proteins. In this article we will review the current understanding of titin, obscurin, and nebulin structure, from the atomic level through the molecular level. PMID:24376425

  19. Giant elves: Lightning-generated electromagnetic pulses in giant planets.

    NASA Astrophysics Data System (ADS)

    Luque Estepa, Alejandro; Dubrovin, Daria; José Gordillo-Vázquez, Francisco; Ebert, Ute; Parra-Rojas, Francisco Carlos; Yair, Yoav; Price, Colin

    2015-04-01

    We currently have direct optical observations of atmospheric electricity in the two giant gaseous planets of our Solar System [1-5] as well as radio signatures that are possibly generated by lightning from the two icy planets Uranus and Neptune [6,7]. On Earth, the electrical activity of the troposphere is associated with secondary electrical phenomena called Transient Luminous Events (TLEs) that occur in the mesosphere and lower ionosphere. This led some researchers to ask if similar processes may also exist in other planets, focusing first on the quasi-static coupling mechanism [8], which on Earth is responsible for halos and sprites and then including also the induction field, which is negligible in our planet but dominant in Saturn [9]. However, one can show that, according to the best available estimation for lightning parameters, in giant planets such as Saturn and Jupiter the effect of the electromagnetic pulse (EMP) dominates the effect that a lightning discharge has on the lower ionosphere above it. Using a Finite-Differences, Time-Domain (FDTD) solver for the EMP we found [10] that electrically active storms may create a localized but long-lasting layer of enhanced ionization of up to 103 cm-3 free electrons below the ionosphere, thus extending the ionosphere downward. We also estimate that the electromagnetic pulse transports 107 J to 1010 J toward the ionosphere. There emissions of light of up to 108 J would create a transient luminous event analogous to a terrestrial elve. Although these emissions are about 10 times fainter than the emissions coming from the lightning itself, it may be possible to target them for detection by filtering the appropiate wavelengths. [1] Cook, A. F., II, T. C. Duxbury, and G. E. Hunt (1979), First results on Jovian lightning, Nature, 280, 794, doi:10.1038/280794a0. [2] Little, B., C. D. Anger, A. P. Ingersoll, A. R. Vasavada, D. A. Senske, H. H. Breneman, W. J. Borucki, and The Galileo SSI Team (1999), Galileo images of

  20. Stimulatory action of mitemcinal (GM-611), an acid-resistant non-peptide motilin receptor agonist, on colonic motor activity and defecation: spontaneous and mitemcinal-induced giant migrating contractions during defecation in dogs.

    PubMed

    Hirabayashi, T; Morikawa, Y; Matsufuji, H; Hoshino, K; Hagane, K; Ozaki, K

    2009-10-01

    The aim of this study was to characterize giant migrating contractions (GMCs) during spontaneous defecation in dogs and to investigate the effect of mitemcinal (an orally active and highly acid-resistant motilin receptor agonist) on colonic motility to assess the possibility of using it for the treatment of colonic motility disorders. To assess colonic motility, strain-gauge force transducers were implanted on the gastrointestinal tract of five dogs, and the behaviour of the dogs was monitored with a noctovision-video camera system. The effect of mitemcinal (0, 3, 10 or 30 mg per dog) and sennoside (300 mg per dog) on colonic motility was assessed 24 h after oral administration. During a 39-day period, the starting point of most of the 140 GMCs was between the transverse colon and the descending colon, but some variation was observed. In the daytime, the GMCs originated from somewhat more proximal positions than at night. Mitemcinal caused an increase in the GMC-index (integration of contractile amplitude and duration) and proximal translocation of the GMC starting point, but did not cause an increase in the number of defecations 12 h after administration. Sennoside, however, caused a significant increase in the number of defecations, an increase in the GMC-index, and prolongation of the duration of GMCs. The GMC starting point in the canine colon varied during spontaneous defecation. Mitemcinal was a potent prokinetic drug to mimic a spontaneous defecation compared with sennoside. Mitemcinal evacuates more intestinal luminal contents during the defecation than does sennoside.

  1. Giant right atrial thrombi treated with thrombolysis.

    PubMed

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Ramos Cuadra, José Angel; Lara Toral, Juan; Lozano Cabezas, Cristobal; Fernández Guerrero, Juan Carlos

    2008-04-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery.

  2. Giant right atrial thrombi treated with thrombolysis

    PubMed Central

    Ruiz-Bailén, Manuel; López-Caler, Carmen; Castillo-Rivera, Ana; Rucabado-Aguilar, Luis; Cuadra, José Ángel Ramos; Toral, Juan Lara; Cabezas, Cristobal Lozano; Guerrero, Juan Carlos Fernández

    2008-01-01

    The present report describes giant atrial thrombi that were treated with thrombolysis in a community hospital. Two patients with giant atrial thrombi whose treatment involved complications are presented. Both patients developed cardiogenic shock and were treated unsuccessfully with thrombolysis. Because thrombolysis of giant thrombi may be ineffective, patients in this situation may require surgery. PMID:18401474

  3. Cabergoline treatment in invasive giant prolactinoma.

    PubMed

    Alsubaie, Sadeem; Almalki, Mussa H

    2014-01-01

    Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically.

  4. Charting the Giants

    NASA Astrophysics Data System (ADS)

    2004-06-01

    zero expansion asymptotically after an infinite time and has a flat geometry). All three observational tests by means of supernovae (green), the cosmic microwave background (blue) and galaxy clusters converge at a Universe around Ωm ~ 0.3 and ΩΛ ~ 0.7. The dark red region for the galaxy cluster determination corresponds to 95% certainty (2-sigma statistical deviation) when assuming good knowledge of all other cosmological parameters, and the light red region assumes a minimum knowledge. For the supernovae and WMAP results, the inner and outer regions corespond to 68% (1-sigma) and 95% certainty, respectively. References: Schuecker et al. 2003, A&A, 398, 867 (REFLEX); Tonry et al. 2003, ApJ, 594, 1 (supernovae); Riess et al. 2004, ApJ, 607, 665 (supernovae) Galaxy clusters are far from being evenly distributed in the Universe. Instead, they tend to conglomerate into even larger structures, "super-clusters". Thus, from stars which gather in galaxies, galaxies which congregate in clusters and clusters tying together in super-clusters, the Universe shows structuring on all scales, from the smallest to the largest ones. This is a relict of the very early (formation) epoch of the Universe, the so-called "inflationary" period. At that time, only a minuscule fraction of one second after the Big Bang, the tiny density fluctuations were amplified and over the eons, they gave birth to the much larger structures. Because of the link between the first fluctuations and the giant structures now observed, the unique REFLEX catalogue - the largest of its kind - allows astronomers to put considerable constraints on the content of the Universe, and in particular on the amount of dark matter that is believed to pervade it. Rather interestingly, these constraints are totally independent from all other methods so far used to assert the existence of dark matter, such as the study of very distant supernovae (see e.g. ESO PR 21/98) or the analysis of the Cosmic Microwave background (e

  5. Magma Reservoirs Feeding Giant Radiating Dike Swarms: Insights from Venus

    NASA Technical Reports Server (NTRS)

    Grosfils, E. B.; Ernst, R. E.

    2003-01-01

    Evidence of lateral dike propagation from shallow magma reservoirs is quite common on the terrestrial planets, and examination of the giant radiating dike swarm population on Venus continues to provide new insight into the way these complex magmatic systems form and evolve. For example, it is becoming clear that many swarms are an amalgamation of multiple discrete phases of dike intrusion. This is not surprising in and of itself, as on Earth there is clear evidence that formation of both magma reservoirs and individual giant radiating dikes often involves periodic magma injection. Similarly, giant radiating swarms on Earth can contain temporally discrete subswarms defined on the basis of geometry, crosscutting relationships, and geochemical or paleomagnetic signatures. The Venus data are important, however, because erosion, sedimentation, plate tectonic disruption, etc. on Earth have destroyed most giant radiating dike swarm's source regions, and thus we remain uncertain about the geometry and temporal evolution of the magma sources from which the dikes are fed. Are the reservoirs which feed the dikes large or small, and what are the implications for how the dikes themselves form? Does each subswarm originate from a single, periodically reactivated reservoir, or do subswarms emerge from multiple discrete geographic foci? If the latter, are these discrete foci located at the margins of a single large magma body, or do multiple smaller reservoirs define the character of the magmatic center as a whole? Similarly, does the locus of magmatic activity change with time, or are all the foci active simultaneously? Careful study of giant radiating dike swarms on Venus is yielding the data necessary to address these questions and constrain future modeling efforts. Here, using giant radiating dike swarms from the Nemesis Tessera (V14) and Carson (V43) quadrangles as examples, we illustrate some of the dike swarm focal region diversity observed on Venus and briefly explore some

  6. Dynamics of Giant Planet Polar Vortices

    NASA Astrophysics Data System (ADS)

    Brueshaber, Shawn R.; Sayanagi, Kunio M.

    2016-10-01

    The polar atmospheres of the giant planets have come under increasing interest since a compact, warm-core, stable, cyclonic polar vortex was discovered at each of Saturn's poles. In addition, the south pole of Neptune appears to have a similar feature, and Uranus' north pole is exhibiting activity that could indicate the formation of a polar vortex. We investigate the formation and maintenance of these giant planet polar vortices by varying several key atmospheric dynamics parameters in a forced-dissipative, 1.5-layer shallow water model. Our simulations are run using the EPIC (Explicit Planetary Isentropic Coordinate) global circulation model, to which we have added a gamma-plane rectangular grid option appropriate for simulating polar atmospheric dynamics.In our numerical simulations, we vary the atmospheric deformation radius, planetary rotation rate, storm forcing intensity, and storm vorticity (cyclone-to-anticyclone) ratio to determine what combination of values favors the formation of a polar vortex. We find that forcing the atmosphere by injecting small-scale mass perturbations ("storms") to form either all cyclones, all anticyclones, or equal numbers of both, may all result in a cyclonic polar vortex. Additionally, we examine the role of eddy momentum convergence in the intensification and maintenance of a polar cyclone.Our simulation results are applicable to understanding all four of the solar system giant planets. In the future, we plan to expand our modeling effort with a more realistic 3D primitive equations model, also with a gamma-plane rectangular grid using EPIC. With our 3D primitive equations model, we will study how various vertical atmospheric stratification structures influence the formation and maintenance of a polar cyclone. While our shallow-water model only involves storms of a single layer, a 3D primitive equations model allows us to study how storms of finite vertical extent and at differing levels in the atmosphere may further favor

  7. Giant Serpentine Aneurysms: Multidisciplinary Management

    PubMed Central

    Anshun, W.; Feng, L.; Daming, W.

    2000-01-01

    Summary Sixty-five cases of intracranial giant serpentine aneurysms (GSΛs), including 61 cases reported in the literature and four additional cases presented in this study were reviewed. The clinical presentation, possible causes, natural history, and especially management of GSAs are discussed with emphasis on the need for aggressive intervention and multidisciplinary management. PMID:20667180

  8. On the Shoulders of Giants...

    DTIC Science & Technology

    2013-01-01

    REFERENCES 1. Newton I. Turnbull HW, ed. Correspondence of Isaac Newton . Vol I: 1661Y1675. Cambridge, United Kingdom: Cambridge University Press; 1959:416...calendar), Sir Isaac Newtonopined to Robert Hooke, ‘‘If I have seen further [than you and Descartes], it is by standing on the shoulders of giants.’’1 That

  9. The giant panda gut microbiome.

    PubMed

    Wei, Fuwen; Wang, Xiao; Wu, Qi

    2015-08-01

    Giant pandas (Ailuropoda melanoleuca) are bamboo specialists that evolved from carnivores. Their gut microbiota probably aids in the digestion of cellulose and this is considered an example of gut microbiota adaptation to a bamboo diet. However, this issue remains unresolved and further functional and compositional studies are needed.

  10. Nursery of Giants

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Hidden behind a shroud of dust in the constellation Cygnus is a stellar nursery called DR21, which is giving birth to some of the most massive stars in our galaxy. Visible light images reveal no trace of this interstellar cauldron because of heavy dust obscuration. In fact, visible light is attenuated in DR21 by a factor of more than 10,000,000,000,000,000,000,000,000,000,000,000,000,000 (ten thousand trillion heptillion).

    New images from NASA's Spitzer Space Telescope allow us to peek behind the cosmic veil and pinpoint one of the most massive natal stars yet seen in our Milky Way galaxy. The never-before-seen star is 100,000 times as bright as the Sun. Also revealed for the first time is a powerful outflow of hot gas emanating from this star and bursting through a giant molecular cloud.

    This image is a large-scale mosaic assembled from individual photographs obtained with the InfraRed Array Camera (IRAC) aboard Spitzer. The image covers an area about two times that of a full moon. The mosaic is a composite of images obtained at mid-infrared wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). The brightest infrared cloud near the top center corresponds to DR21, which presumably contains a cluster of newly forming stars at a distance of 10,000 light-years.

    Protruding out from DR21 toward the bottom left of the image is a gaseous outflow (green), containing both carbon monoxide and molecular hydrogen. Data from the Spitzer spectrograph, which breaks light into its constituent individual wavelengths, indicate the presence of hot steam formed as the outflow heats the surrounding molecular gas. Outflows are physical signatures of processes that create supersonic beams, or jets, of gas. They are usually accompanied by discs of material around the new star, which likely contain the materials from which future planetary systems are formed. Additional newborn stars, depicted in green, can be seen surrounding the

  11. IL-4 induces the formation of multinucleated giant cells and expression of β5 integrin in central giant cell lesion

    PubMed Central

    Aghbali, Amirala; Rafieyan, Sona; Mohamed-Khosroshahi, Leila; Baradaran, Behzad; Shanehbandi, Dariush

    2017-01-01

    Background It is now well established that IL-4 has a central role in the development of monocytes to multinucleated giant cells (MGCs) by inducing the expression of integrins on the surface of monocytes. The aim of this study was to investigate the potential role of IL-4 in induction of β5 integrin expression in the peripheral blood samples of patients with giant cell granuloma. Material and Methods Monocytes were isolated from peripheral blood samples of patients with central giant cell granuloma (CGCG) and healthy controls using human Monocyte Isolation Kit II. Isolated monocytes were then cultured in the absence or presence of IL-4 (10 and 20 ng/mL), and following RNA extraction and cDNA synthesis, Real-time PCR was performed to determine the level of β5 integrin expression. The formation of CGCGs and morphological analyses were done under light microscopy. For confirmation of CGCGs, immunocytochemistry technique was also carried out by anti-RANK (receptor-activator of NF-κB ligand) antibody. Results In both patient and control groups, β5 levels were significantly enhanced by increasing the IL-4 dose from 10 to 20 ng/mL. In addition, these differences were significant between patient and control groups without IL-4 treatment. On the other hand, the number of cells which expressed RANK and therefore the number of giant cells were significantly higher in the patient group in comparison to controls, as assessed by immunohistochemistry evaluations. Conclusions In this study, we showed an elevation in the expression levels of β5 integrin when stimulated by IL-4. It is strongly indicated that this integrin acts as an important mediator during macrophage to macrophage fusion and development of giant cells. Key words:β5 integrin, giant cell, Il-4, monocyte, rank. PMID:27918730

  12. Giant piezoelectricity on Si for hyperactive MEMS.

    PubMed

    Baek, S H; Park, J; Kim, D M; Aksyuk, V A; Das, R R; Bu, S D; Felker, D A; Lettieri, J; Vaithyanathan, V; Bharadwaja, S S N; Bassiri-Gharb, N; Chen, Y B; Sun, H P; Folkman, C M; Jang, H W; Kreft, D J; Streiffer, S K; Ramesh, R; Pan, X Q; Trolier-McKinstry, S; Schlom, D G; Rzchowski, M S; Blick, R H; Eom, C B

    2011-11-18

    Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.

  13. Magnetocardiography with sensors based on giant magnetoresistance

    NASA Astrophysics Data System (ADS)

    Pannetier-Lecoeur, M.; Parkkonen, L.; Sergeeva-Chollet, N.; Polovy, H.; Fermon, C.; Fowley, C.

    2011-04-01

    Biomagnetic signals, mostly due to the electrical activity in the body, are very weak and they can only be detected by the most sensitive magnetometers, such as Superconducting Quantum Interference Devices (SQUIDs). We report here biomagnetic recordings with hybrid sensors based on Giant MagnetoResistance (GMR). We recorded magnetic signatures of the electric activity of the human heart (magnetocardiography) in healthy volunteers. The P-wave and QRS complex, known from the corresponding electric recordings, are clearly visible in the recordings after an averaging time of about 1 min. Multiple recordings at different locations over the chest yielded a dipolar magnetic field map and allowed localizing the underlying current sources. The sensitivity of the GMR-based sensors is now approaching that of SQUIDs and paves way for spin electronics devices for functional imaging of the body.

  14. Isolated and combined exposure to ammonia and nitrite in giant freshwater pawn (Macrobrachium rosenbergii): effects on the oxidative stress, antioxidant enzymatic activities and apoptosis in haemocytes.

    PubMed

    Zhang, Yufan; Ye, Chaoxia; Wang, Anli; Zhu, Xuan; Chen, Changhong; Xian, Jianan; Sun, Zhenzhu

    2015-10-01

    The residual contaminators such as ammonia and nitrite are widely considered as relevant sources of aquatic environmental pollutants, posing a great threat to shrimp survival. To study the toxicological effects of ammonia and nitrite exposure on the innate immune response in invertebrates, we investigated the oxidative stress and apoptosis in haemocytes of freshwater prawn (Macrobrachium rosenbergii) under isolated and combined exposure to ammonia and nitrite in order to provide useful information about adult prawn immune responses. M. rosenbergii (13.44 ± 2.75 g) were exposed to 0, 5, and 25 mg/L total ammonia-N (TAN) and 0, 5, and 20 mg/L nitrite-N for 24 h. All ammonia concentrations were combined with all nitrite concentrations, making a total of nine treatments studied. Following the exposure treatment, antioxidant enzyme activity, reactive oxygen species (ROS) generation, nitric oxide (NO) generation, and apoptotic cell ratio of haemocytes were measured using flow cytometry. Results indicated that ROS generation was sensitive to the combined effect of ammonia and nitrite, which subsequently affected the Cu-Zn SOD activity. In addition, CAT showed the highest activity at 5 mg/L TAN while GPx decreased at 5 mg/L TAN and returned towards baseline at 25 mg/L. NO generation synchronized with the apoptotic cell ratio in haemocytes, indicating that NO production was closely associated with programmed cell death. Both NO production and apoptotic ratios significantly decreased following 25 mg/L TAN, which may be due to the antagonistic regulation of NO and GPx. We hypothesized that the toxicological effect of nitrite exhibited less change in physiological changes compared to that of ammonia, because of the high tolerance to nitrite exposure in mature M. rosenbergii and/or the competitive effects of chloride ions. Taken together, these results showed that ammonia and nitrite caused a series of combined oxidative stress and apoptosis in M. rosenbergi, but further

  15. Giant Herbig-Haro Flows

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo; Bally, John; Devine, David

    1997-12-01

    We present the discovery of a number of Herbig-Haro flows which extend over parsec-scale distances. The largest of these is the well known HH 111 jet complex, which is shown, through CCD images and a proper motion study, to have an angular extent of almost one degree on the sky, corresponding to 7.7 pc, making it the largest known HH flow. In our imaging survey we also found that T Tauri is at the center of a huge bipolar HH flow, HH 355, with a total extent of 38 arcmin, corresponding to 1.55 pc, and aligned with the axis of the tiny HH 255 flow surrounding the infrared companion T Tau S. We additionally have found a number of other giant HH flow candidates, including HH 315 at PV Cep, HH 41/295 at Haro 5a/6a, HH 300 in Bl8w, HH 354 in Li 165, HH 376 in Li 152, and HH 114/115 and HH 243/244/245/179 in the X Orionis molecular ring. It thus appears that it is common for HH flows to attain parsec-scale dimensions. The ubiquity of parsec-scale HH flows profoundly alters our view of the impact of young stars on their environment. Giant flows have dynamical ages comparable to the duration of the accretion phase of the sources, and provide a fossil record of their mass loss and accretion history. Multiple internal working surfaces and their S-shaped point symmetry provide evidence for variability of ejection velocity and orientation of the source jets. Giant HH flows are either longer or comparable in length to associated CO outflows, providing evidence for unified models in which HH flows power CO flows. Many giant flows have burst out of their source cloud cores and are dissociating molecules and injecting momentum and kinetic energy into the interclump medium of the host clouds. They contribute to the UV radiation field, and may produce C I and C ii in cloud interiors. Giant flows may contribute to the chemical rejuvenation of clouds, the generation of turbulent motions, and the self-regulation of star formation. The terminal working surfaces of giant flows may be

  16. Surface modification with multiphilic ligands at detectable well defined active positions of nano-object of giant wheel shaped molybdenum blue showing third-order nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Zhang, Lijuan; Li, Yuhao; Zhou, Yunshan

    2010-04-01

    The reaction of an aqueous solution of sodium molybdate with L-tyrosine in the presence of reducing agent results in the formation of a new compound of the formula of Na 8Co 3[Mo VI126 Mo V28O 462H 14(H 2O) 46(HOC 6H 4CH 2CH( NH3+)COO -) 12]·ca. 200H 2O. The compound contains nanosized ring-shaped clusters with tyrosine ligands possessing different types of functional groups (one -CO 2, one -NH3+ and one -ArOH) coordinated through the carboxylate groups at the active sites of the inner cavity. Importantly, the result demonstrates that not only active sites/areas of the cluster surface under a specified condition can be directly monitored and detected but also novel type surfaces within the cavity of a nano-structured ring-shaped cluster can be generated simultaneously. The nonlinear optical properties of the new cluster are studied using the well-known Z-scan technique at a wavelength of 532 nm with laser pulse duration of 18 ps. The results show that the new cluster exhibits interesting self-focusing nonlinear optical response with the real and imaginary parts of the third-order nonlinear optical susceptibility χ(3) being 1.069 × 10 -13(esu) and 2.529 × 10 -15(esu), respectively, which may find application in material science.

  17. Sizing Up Red-Giant Twins

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-02-01

    -resolution ground-based spectroscopy at the Fred Lawrence Whipple Observatory and Apache Point Observatory, Rawls and collaborators established that the two stars have masses of 2.17 and 2.15 solar masses, and radii of 8.4 and 8.3 solar radii.Not Quite Twins?Intriguingly, when the authors measured the stellar oscillations from the binary, they were only able to pick out one signal. Using the scaling relations, their measurements reveal that the star producing the oscillations has a mass of 2.17 solar masses and radius of 8.3 radii consistent with both red giants in the system, within error bars. This provides excellent confirmation of the scaling relations for obtaining mass and radius, but it also raises a new question: why is only one star of this twin system producing oscillations?Rawls and collaborators have an idea: one star might be more magnetically active than the other, causing the suppression of oscillations in the more active star. The authors observations and detailed modeling support this idea, but similar analyses of the rest of the red-giant eclipsing binaries identified in the Kepler field will help to determine if KIC 9246715 is unusual, or if this behavior is common among such systems.CitationMeredith L. Rawls et al 2016 ApJ 818 108. doi:10.3847/0004-637X/818/2/108

  18. Proteorhodopsin genes in giant viruses.

    PubMed

    Yutin, Natalya; Koonin, Eugene V

    2012-10-04

    Viruses with large genomes encode numerous proteins that do not directly participate in virus biogenesis but rather modify key functional systems of infected cells. We report that a distinct group of giant viruses infecting unicellular eukaryotes that includes Organic Lake Phycodnaviruses and Phaeocystis globosa virus encode predicted proteorhodopsins that have not been previously detected in viruses. Search of metagenomic sequence data shows that putative viral proteorhodopsins are extremely abundant in marine environments. Phylogenetic analysis suggests that giant viruses acquired proteorhodopsins via horizontal gene transfer from proteorhodopsin-encoding protists although the actual donor(s) could not be presently identified. The pattern of conservation of the predicted functionally important amino acid residues suggests that viral proteorhodopsin homologs function as sensory rhodopsins. We hypothesize that viral rhodopsins modulate light-dependent signaling, in particular phototaxis, in infected protists.

  19. Giant viruses come of age.

    PubMed

    Fischer, Matthias G

    2016-06-01

    Viruses with genomes up to a few megabases in length are a common occurrence in nature, even though they have escaped our notice until recently. These giant viruses infect mainly single-celled eukaryotes and isolation efforts concentrating on amoebal hosts alone have spawned hundreds of viral isolates, featuring viruses with previously unseen virion morphologies and the largest known viral genomes and particles. One of the challenges that lie ahead is to analyze and categorize the available data and to establish an approved classification system that reflects the evolutionary relationships and biological properties of these viruses. Extensive sampling of Acanthamoeba-infecting mimiviruses and initial characterization of their virophage parasites have provided a first blueprint of the genetic diversity and composition of a giant virus clade that will facilitate the taxonomic grouping of these fascinating microorganisms.

  20. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    PubMed

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50 nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18 mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18 mg Mn-oxide NPs/kg shows enhanced (P<0.05) growth performance, including final weight and weight gain (WG). Significant differences (P<0.05) in feed conversion ratio (FCR) were observed in prawn fed with different diets. Additionally, prawns fed with 3.0-18 mg/kg Mn-oxide NPs supplemented diets achieved significant (P<0.05) improvement in growth performance, digestive enzyme activities and muscle biochemical compositions, while, the prawns fed with 16 mg/kg of Mn-oxide NPs showed enhanced performance. Prawns fed on diet supplemented with 16 mg/kg Mn-oxide NPs showed significantly (P<0.05) higher total protein level. The antioxidants enzymatic activity (SOD and CAT) metabolic enzymes status in muscle and hepatopancreas showed no significant (P>0.05) alterations in prawns fed with 3.0-18 mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16 mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16 mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system.

  1. Giant thermoelectric effect in graphene

    NASA Astrophysics Data System (ADS)

    Dragoman, D.; Dragoman, M.

    2007-11-01

    The paper predicts a giant thermoelectric coefficient in a nanostructure consisting of metallic electrodes periodically patterned over graphene, which is deposited on a silicon dioxide substrate. The Seebeck coefficient in this device attains 30mV/K, this value being among the largest reported ever. The calculations are based on a transfer matrix approach that takes a particular form for graphene-based devices. The results are important for future nanogenerators with applications in the area of sensors, energy harvesting, and scavenging.

  2. Observed Properties of Giant Cells

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Upton, Lisa; Colegrove, Owen

    2014-01-01

    The existence of Giant Cells has been suggested by both theory and observation for over 45 years. We have tracked the motions of supergranules in SDO/HMI Doppler velocity data and find larger (Giant Cell) flows that persist for months. The flows in these cells are clockwise around centers of divergence in the north and counter-clockwise in the south. Equatorward flows are correlated with prograde flows - giving the transport of angular momentum toward the equator that is needed to maintain the Sun's rapid equatorial rotation. The cells are most pronounced at mid- and high-latitudes where they exhibit the rotation rates representative of those latitudes. These are clearly large, long-lived, cellular features, with the dynamical characteristics expected from the effects of the Sun's rotation, but the shapes of the cells are not well represented in numerical models. While the Giant Cell flow velocities are small (<10 m/s), their long lifetimes should nonetheless substantially impact the transport of magnetic flux in the Sun's near surface layers.

  3. KEPLER RAPIDLY ROTATING GIANT STARS

    SciTech Connect

    Costa, A. D.; Martins, B. L. Canto; Bravo, J. P.; Paz-Chinchón, F.; Chagas, M. L. das; Leão, I. C.; Oliveira, G. Pereira de; Silva, R. Rodrigues da; Roque, S.; Oliveira, L. L. A. de; Silva, D. Freire da; De Medeiros, J. R.

    2015-07-10

    Rapidly rotating giant stars are relatively rare and may represent important stages of stellar evolution, resulting from stellar coalescence of close binary systems or accretion of substellar companions by their hosting stars. In the present Letter, we report 17 giant stars observed in the scope of the Kepler space mission exhibiting rapid rotation behavior. For the first time, the abnormal rotational behavior for this puzzling family of stars is revealed by direct measurements of rotation, namely from photometric rotation period, exhibiting a very short rotation period with values ranging from 13 to 55 days. This finding points to remarkable surface rotation rates, up to 18 times the rotation of the Sun. These giants are combined with six others recently listed in the literature for mid-infrared (IR) diagnostics based on Wide-field Infrared Survey Explorer information, from which a trend for an IR excess is revealed for at least one-half of the stars, but at a level far lower than the dust excess emission shown by planet-bearing main-sequence stars.

  4. Hairpin Furans and Giant Biaryls.

    PubMed

    Geng, Xin; Mague, Joel T; Donahue, James P; Pascal, Robert A

    2016-05-06

    The thermal reaction of two cyclopentadienones with 5,5'-binaphthoquinone or 6,6'-dimethoxy-5,5'-binaphthoquinone in refluxing nitrobenzene (210 °C) gives, in a single synthetic step that includes two Diels-Alder additions, two decarbonylations, and two dehydrogenations, giant biaryl bisquinones (compounds 13, 14, 15, 18, and 21). However, when two cyclopentadienones react with 6,6'-dimethoxy-5,5'-binaphthoquinone in nitrobenzene at higher temperatures (250-260 °C), the resulting products are molecular ribbons composed of two twisted aromatic systems fused to a heteropentahelicene (19, 20, and 22). These molecules are representatives of a new class of chiral polycyclic aromatic compounds, the "hairpin furans". Interestingly, reheating a dimethoxy-substituted giant biaryl (e.g., 21) in nitrobenzene at 260 °C does not yield the corresponding hairpin furan (22), and mechanistic studies indicate that some intermediate or byproduct of the synthesis of the giant biaryls is a reagent or catalyst necessary for the conversion of the dimethoxybiaryl to the furan.

  5. Electrodynamics in Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Koskinen, T.; Yelle, R. V.; Lavvas, P.; Cho, J.

    2014-12-01

    The atmospheres of close-in extrasolar giant planets such as HD209458b are strongly ionized by the UV flux of their host stars. We show that photoionization on such planets creates a dayside ionosphere that extends from the thermosphere to the 100 mbar level. The resulting peak electron density near the 1 mbar level is higher than that encountered in any planetary ionosphere of the solar system, and the model conductivity is in fact comparable to the atmospheres of Sun-like stars. As a result, the momentum and energy balance in the upper atmosphere of HD209458b and similar planets can be strongly affected by ion drag and resistive heating arising from wind-driven electrodynamics. Despite much weaker ionization, electrodynamics is nevertheless also important on the giant planets of the solar system. We use a generic framework to constrain the conductivity regimes on close-in extrasolar planets, and compare the results with conductivites based on the same approach for Jupiter and Saturn. By using a generalized Ohm's law and assumed magnetic fields, we then demonstrate the basic effects of wind-driven ion drag in giant planet atmospheres. Our results show that ion drag is often significant in the upper atmosphere where it can also substantially alter the energy budget through resistive heating.

  6. Giant panda conservation science: how far we have come.

    PubMed

    Swaisgood, Ronald R; Wei, Fuwen; Wildt, David E; Kouba, Andrew J; Zhang, Zejun

    2010-04-23

    The giant panda is a conservation icon, but science has been slow to take up its cause in earnest. In the past decade, researchers have been making up for lost time, as reflected in the flurry of activity reported at the symposium Conservation Science for Giant Pandas and Their Habitat at the 2009 International Congress for Conservation Biology (ICCB) in Beijing. In reports addressing topics ranging from spatial ecology to molecular censusing, from habitat recovery in newly established reserves to earthquake-induced habitat loss, from new insights into factors limiting carrying capacity to the uncertain effects of climate change, this symposium displayed the vibrant and blossoming application of science to giant panda conservation. Collectively, we find that we have come a long way, but we also reach an all-too-familiar conclusion: the more we know, the more challenges are revealed. While many earlier findings are supported, many of our assumptions are debatable. Here we discuss recent advancements in conservation science for giant pandas and suggest that the way forward is more direct application of emerging science to management and policy.

  7. Giant-cell granuloma of the axis.

    PubMed

    González-Martínez, Emilio; Santamarta, David; Lomas-García, Jesús; Ibáñez-Plágaro, F Javier; Fernández-Fernández, J Javier; Ariño, Teresa Ribas; García-Cosamalón, José

    2012-02-01

    Giant-cell granuloma is a benign and nonneoplastic lesion with an expansive and locally destructive behavior. It typically involves the mandible and the maxilla. Only 1 case arising from the odontoid process of the axis has been reported previously. The authors report on a 64-year-old man with a giant-cell granuloma of the axis. They review this uncommon entity, emphasizing the complexity of differentiating between this lesion and other giant-cell tumors.

  8. Cabergoline Treatment in Invasive Giant Prolactinoma

    PubMed Central

    Alsubaie, Sadeem; Almalki, Mussa H

    2014-01-01

    Patients with invasive giant prolactinoma suffer from a constellation of symptoms including headache, blurred vision, lethargy, and sexual dysfunction. Cabergoline, a potent dopamine agonist, is a known medication prescribed for the treatment of invasive giant prolactinoma. Here, we report a case of invasive giant prolactinoma in a 52-year-old Saudi male with dramatic response to cabergoline treatment clinically, biochemically, and radiologically. PMID:25002819

  9. Guiding the Giant

    NASA Astrophysics Data System (ADS)

    1998-08-01

    New ESO Survey Provides Targets for the VLT Giant astronomical telescopes like the ESO Very Large Telescope (VLT) must be used efficiently. Observing time is expensive and there are long waiting lines of excellent research programmes. Thus the work at the telescope must be very well prepared and optimized as much as possible - mistakes should be avoided and no time lost! Astronomers working with the new 8-m class optical/infrared telescopes must base their observations on detailed lists of suitable target objects if they want to perform cutting-edge science. This is particularly true for research programmes that depend on observations of large samples of comparatively rare, distant objects. This type of work requires that extensive catalogues of such objects must be prepared in advance. One such major catalogue - that will serve as a very useful basis for future VLT observations - has just become available from the new ESO Imaging Survey (EIS). The Need for Sky Surveys Astronomers have since long recognized the need to carry out preparatory observations with other telescopes in order to "guide" large telescopes. To this end, surveys of smaller or larger parts of the sky have been performed by wide-field telescopes, paving the way for subsequent work at the limits of the largest available ground-based telescopes. For instance, a complete photographic survey of the sourthern sky (declination < -17.5°) was carried out in the 1970's with the ESO 1-metre Schmidt Telescope in support of the work at the 3.6-m telescope at the ESO La Silla observatory. However, while until recently most observational programmes could rely on samples of objects found on photographic plates, this is no longer possible. New image surveys must match the fainter limiting magnitudes reached by the new and larger telescopes. Modern digital, multi-colour, deep imaging surveys have thus become an indispensable complement to the 8-m telescopes. The new generation of imaging surveys will, without

  10. Nucleosynthesis in asymptotic giant branch stars

    SciTech Connect

    El Eid, Mounib F.

    2014-05-09

    The nucleosynthesis in asymptotic giant branch stars (briefly: AGB)is a challenging and fascinating subject in the theory of stellar evolution and important for observations as well. This is because about of half the heavy elements beyond iron are synthesized during thermal pulsation phases of these stars. Furthermore, the understanding of the production of the heavy elements and some light elements like carbon and fluorine represent a powerful tool to get more insight into the internal structure of these stars. The diversity of nuclear processing during the AGB phases may also motivate experimental activities in measuring important nuclear reactions. In this contribution, we emphasize several interesting feature of the nucleosynthesis in AGB stars which still needs further elaboration especially from theoretical point of view.

  11. Nucleosynthesis in asymptotic giant branch stars

    NASA Astrophysics Data System (ADS)

    El Eid, Mounib F.

    2014-05-01

    The nucleosynthesis in asymptotic giant branch stars (briefly: AGB)is a challenging and fascinating subject in the theory of stellar evolution and important for observations as well. This is because about of half the heavy elements beyond iron are synthesized during thermal pulsation phases of these stars. Furthermore, the understanding of the production of the heavy elements and some light elements like carbon and fluorine represent a powerful tool to get more insight into the internal structure of these stars. The diversity of nuclear processing during the AGB phases may also motivate experimental activities in measuring important nuclear reactions. In this contribution, we emphasize several interesting feature of the nucleosynthesis in AGB stars which still needs further elaboration especially from theoretical point of view.

  12. Red giants: then and now

    NASA Astrophysics Data System (ADS)

    Faulkner, John

    Fred Hoyle's work on the structure and evolution of red giants, particularly his pathbreaking contribution with Martin Schwarzschild (Hoyle and Schwarzschild 1955), is both lauded and critically assessed. In his later lectures and work with students in the early 1960s, Hoyle presented more physical ways of understanding some of the approximations used, and results obtained, in that seminal paper. Although later ideas by other investigators will be touched upon, Hoyle's viewpoint - that low-mass red giants are essentially white dwarfs with a serious mass-storage problem - is still extremely fruitful. Over the years, I have further developed his method of attack. Relatively recently, I have been able to deepen and broaden the approach, finally extending the theory to provide a unifying treatment of the structure of low-mass stars from the main sequence though both the red-giant and horizontal-branch phases of evolution. Many aspects of these stars that had remained puzzling, even mysterious, for decades have now fallen into place, and some questions have been answered that were not even posed before. With low-mass red giants as the simplest example, this recent work emphasizes that stars, in general, may have at least two distinct but very important centres: (I) a geometrical centre, and (II) a separate nuclear centre, residing in a shell outside a zero-luminosity dense core for example. This two-centre perspective leads to an explicit, analytical, asymptotic theory of low-mass red-giant structure. It enables one to appreciate that the problem of understanding why such stars become red giants is one of anticipating a remarkable yet natural structural bifurcation that occurs in them. This bifurcation occurs because of a combination of known and understandable facts just summarized namely that, following central hydrogen exhaustion, a thin nuclear-burning shell does develop outside a more-or-less dense core. In the resulting theory, both ρsh/ρolinec and

  13. Red Giants in Eclipsing Binaries as a Benchmark for Asteroseismology

    NASA Astrophysics Data System (ADS)

    Rawls, Meredith L.

    2016-04-01

    Red giants with solar-like oscillations are astrophysical laboratories for probing the Milky Way. The Kepler Space Telescope revolutionized asteroseismology by consistently monitoring thousands of targets, including several red giants in eclipsing binaries. Binarity allows us to directly measure stellar properties independently of asteroseismology. In this dissertation, we study a subset of eight red giant eclipsing binaries observed by Kepler with a range of orbital periods, oscillation behavior, and stellar activity. Two of the systems do not show solar-like oscillations at all. We use a suite of modeling tools to combine photometry and spectroscopy into a comprehensive picture of each star's life. One noteworthy case is a double red giant binary. The two stars are nearly twins, but have one main set of solar-like oscillations with unusually low-amplitude, wide modes, likely due to stellar activity and modest tidal forces acting over the 171 day eccentric orbit. Mixed modes indicate the main oscillating star is on the secondary red clump (a core-He-burning star), and stellar evolution modeling supports this with a coeval history for a pair of red clump stars. The other seven systems are all red giant branch stars (shell-H-burning) with main sequence companions. The two non-oscillators have the strongest magnetic signatures and some of the strongest lifetime tidal forces with nearly-circular 20-34 day orbits. One system defies this trend with oscillations and a 19 day orbit. The four long-period systems (>100 days) have oscillations, more eccentric orbits, and less stellar activity. They are all detached binaries consistent with coevolution. We find the asteroseismic scaling laws are approximately correct, but fail the most for stars that are least like the Sun by systematically overestimating both mass and radius. Strong magnetic activity and tidal effects often occur in tandem and act to suppress solar-like oscillations. These red giant binaries offer an

  14. Spontaneous thrombosis in giant intracranial aneurysms.

    PubMed Central

    Whittle, I R; Dorsch, N W; Besser, M

    1982-01-01

    Twelve patients in a series of 22 with giant intracranial aneurysms demonstrated neuroradiological features of partial or total spontaneous intra-aneurysmal thrombosis. The presence of this intra-aneurysmal clot significantly altered the computed tomographic appearance of the giant aneurysm. Massive intra-aneurysmal thrombosis did not protect against subarachnoid haemorrhage and the likelihood of rupture of a clot containing giant aneurysm was not significantly different from that of a non-thrombosed giant aneurysm. Although parent artery occlusion from a thrombosed giant aneurysm, and massive aneurysmal thrombosis leading to the formation of giant serpentine aneurysm were documented, these are rare epiphenomena. The risk of embolisation from a partially thrombosed giant aneurysm, which was documented in one case, would appear to be greater than that from a non-thrombosed giant aneurysm. The findings in this series, and a review of literature, suggest that the presence of intra-aneurysmal clot in giant intracranial aneurysms has little prognostic significance and does not alter the management or outcome after treatment. Images PMID:7175528

  15. ORIGIN OF LITHIUM ENRICHMENT IN K GIANTS

    SciTech Connect

    Kumar, Yerra Bharat; Reddy, Bacham E.; Lambert, David L.

    2011-03-20

    In this Letter, we report on a low-resolution spectroscopic survey for Li-rich K giants among 2000 low-mass (M {<=} 3 M{sub sun}) giants spanning the luminosity range from below to above the luminosity of the clump. Fifteen new Li-rich giants including four super Li-rich K giants (log {epsilon}(Li) {>=}3.2) were discovered. A significant finding is that there is a concentration of Li-rich K giants at the luminosity of the clump or red horizontal branch. This new finding is partly a consequence of the fact that our low-resolution survey is the first large survey to include giants well below and above the red giant branch (RGB) bump and clump locations in the H-R diagram. Origin of the lithium enrichment may be plausibly attributed to the conversion of {sup 3}He via {sup 7}Be to {sup 7}Li by the Cameron-Fowler mechanism but the location for the onset of the conversion is uncertain. Two possible opportunities to effect this conversion are discussed: the bump in the first ascent of the RGB and the He-core flash at the tip of the RGB. The finite luminosity spread of the Li-rich giants serves to reject the idea that Li enhancement is, in general, a consequence of a giant swallowing a large planet.

  16. Territoriality of giant otter groups in an area with seasonal flooding.

    PubMed

    Leuchtenberger, Caroline; Magnusson, William E; Mourão, Guilherme

    2015-01-01

    Territoriality carries costs and benefits, which are commonly affected by the spatial and temporal abundance and predictability of food, and by intruder pressure. Giant otters (Pteronura brasiliensis) live in groups that defend territories along river channels during the dry season using chemical signals, loud vocalizations and agonistic encounters. However, little is known about the territoriality of giant otters during the rainy season, when groups leave their dry season territories and follow fish dispersing into flooded areas. The objective of this study was to analyze long-term territoriality of giant otter groups in a seasonal environment. The linear extensions of the territories of 10 giant otter groups were determined based on locations of active dens, latrines and scent marks in each season. Some groups overlapped the limits of neighboring territories. The total territory extent of giant otters was correlated with group size in both seasons. The extent of exclusive territories of giant otter groups was negatively related to the number of adults present in adjacent groups. Territory fidelity ranged from 0 to 100% between seasons. Some groups maintained their territory for long periods, which demanded constant effort in marking and re-establishing their territories during the wet season. These results indicate that the defense capacity of groups had an important role in the maintenance of giant otter territories across seasons, which may also affect the reproductive success of alpha pairs.

  17. Territoriality of Giant Otter Groups in an Area with Seasonal Flooding

    PubMed Central

    Leuchtenberger, Caroline; Magnusson, William E.; Mourão, Guilherme

    2015-01-01

    Territoriality carries costs and benefits, which are commonly affected by the spatial and temporal abundance and predictability of food, and by intruder pressure. Giant otters (Pteronura brasiliensis) live in groups that defend territories along river channels during the dry season using chemical signals, loud vocalizations and agonistic encounters. However, little is known about the territoriality of giant otters during the rainy season, when groups leave their dry season territories and follow fish dispersing into flooded areas. The objective of this study was to analyze long-term territoriality of giant otter groups in a seasonal environment. The linear extensions of the territories of 10 giant otter groups were determined based on locations of active dens, latrines and scent marks in each season. Some groups overlapped the limits of neighboring territories. The total territory extent of giant otters was correlated with group size in both seasons. The extent of exclusive territories of giant otter groups was negatively related to the number of adults present in adjacent groups. Territory fidelity ranged from 0 to 100% between seasons. Some groups maintained their territory for long periods, which demanded constant effort in marking and re-establishing their territories during the wet season. These results indicate that the defense capacity of groups had an important role in the maintenance of giant otter territories across seasons, which may also affect the reproductive success of alpha pairs. PMID:25955248

  18. The SEEDs of Planet Formation: Indirect Signatures of Giant Planets in Transitional Disks

    NASA Technical Reports Server (NTRS)

    Grady, Carol; Currie, T.

    2012-01-01

    We live in a planetary system with 2 gas giant planets, and as a resu lt of RV, transit, microlensing, and transit timing studies have ide ntified hundreds of giant planet candidates in the past 15 years. Su ch studies have preferentially concentrated on older, low activity So lar analogs, and thus tell us little about .when, where, and how gian t planets form in their disks, or how frequently they form in disks associated with intermediate-mass stars.

  19. Evaluating landscape options for corridor restoration between giant panda reserves.

    PubMed

    Wang, Fang; McShea, William J; Wang, Dajun; Li, Sheng; Zhao, Qing; Wang, Hao; Lu, Zhi

    2014-01-01

    The establishment of corridors can offset the negative effects of habitat fragmentation by connecting isolated habitat patches. However, the practical value of corridor planning is minimal if corridor identification is not based on reliable quantitative information about species-environment relationships. An example of this need for quantitative information is planning for giant panda conservation. Although the species has been the focus of intense conservation efforts for decades, most corridor projects remain hypothetical due to the lack of reliable quantitative researches at an appropriate spatial scale. In this paper, we evaluated a framework for giant panda forest corridor planning. We linked our field survey data with satellite imagery, and conducted species occupancy modelling to examine the habitat use of giant panda within the potential corridor area. We then conducted least-cost and circuit models to identify potential paths of dispersal across the landscape, and compared the predicted cost under current conditions and alternative conservation management options considered during corridor planning. We found that due to giant panda's association with areas of low elevation and flat terrain, human infrastructures in the same area have resulted in corridor fragmentation. We then identified areas with high potential to function as movement corridors, and our analysis of alternative conservation scenarios showed that both forest/bamboo restoration and automobile tunnel construction would significantly improve the effectiveness of corridor, while residence relocation would not significantly improve corridor effectiveness in comparison with the current condition. The framework has general value in any conservation activities that anticipate improving habitat connectivity in human modified landscapes. Specifically, our study suggested that, in this landscape, automobile tunnels are the best means to remove current barriers to giant panda movements caused by

  20. Metabolic rates of giant pandas inform conservation strategies

    PubMed Central

    Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

    2016-01-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction. PMID:27264109

  1. Giant number fluctuations in self-propelled particles without alignment

    NASA Astrophysics Data System (ADS)

    Fily, Yaouen; Henkes, Silke; Marchetti, M. Cristina

    2012-02-01

    Giant number fluctuations are a ubiquitous property of active systems. They were predicted using a generic continuum description of active nematics, and have been observed in simulations of Vicsek-type models and in experiments on vibrated granular layers and swimming bacteria. In all of these systems, there is an alignment interaction among the self-propelled units, either imposed as a rule, or arising from hydrodynamic or other medium-mediated couplings. Here we report numerical evidence of giant number fluctuations in a minimal model of self-propelled disks in two dimensions in the absence of any alignment mechanism. The direction of self-propulsion evolves via rotational diffusion and the particles interact solely via a finite range repulsive soft potential. It can be shown that in this system self propulsion is equivalent to a non Markovian noise whose correlation time is controlled by the amplitude of the orientational noise.

  2. Metabolic rates of giant pandas inform conservation strategies

    NASA Astrophysics Data System (ADS)

    Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

    2016-06-01

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

  3. Metabolic rates of giant pandas inform conservation strategies.

    PubMed

    Fei, Yuxiang; Hou, Rong; Spotila, James R; Paladino, Frank V; Qi, Dunwu; Zhang, Zhihe

    2016-06-06

    The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

  4. Warm Disks from Giant Impacts

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    In the process of searching for exoplanetary systems, weve discovered tens of debris disks close around distant stars that are especially bright in infrared wavelengths. New research suggests that we might be looking at the late stages of terrestrial planet formation in these systems.Forming Terrestrial PlanetsAccording to the widely-accepted formation model for our solar-system, protoplanets the size of Mars formed within a protoplanetary disk around our Sun. Eventually, the depletion of the gas in the disk led the orbits of these protoplanets to become chaotically unstable. Finally, in the giant impact stage, many of the protoplanets collided with each other ultimately leading to the formation of the terrestrial planets and their moons as we know them today.If giant impact stages occur in exoplanetary systems, too leading to the formation of terrestrial exoplanets how would we detect this process? According to a study led by Hidenori Genda of the Tokyo Institute of Technology, we might be already be witnessing this stage in observations of warm debris disks around other stars. To test this, Genda and collaborators model giant impact stages and determine what we would expect to see from a system undergoing this violent evolution.Modeling CollisionsSnapshots of a giant impact in one of the authors simulations. The collision causes roughly 0.05 Earth masses of protoplanetary material to be ejected from the system. Click for a closer look! [Genda et al. 2015]The collaborators run a series of simulations evolving protoplanetary bodies in a solar system. The simulations begin 10 Myr into the lifetime of the solar system, i.e., after the gas from the protoplanetary disk has had time to be cleared and the protoplanetary orbits begin to destabilize. The simulations end when the protoplanets are done smashing into each other and have again settled into stable orbits, typically after ~100 Myr.The authors find that, over an average giant impact stage, the total amount of

  5. Sodium in weak G-band giants

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy J.; Lambert, David L.

    1994-01-01

    Sodium abundances have been determined for eight weak G-band giants whose atmospheres are greatly enriched with products of the CN-cycling H-burning reactions. Systematic errors are minimized by comparing the weak G-band giants to a sample of similar but normal giants. If, further, Ca is selected as a reference element, model atmosphere-related errors should largely be removed. For the weak-G-band stars (Na/Ca) = 0.16 +/- 0.01, which is just possibly greater than the result (Na/Ca) = 0.10 /- 0.03 from the normal giants. This result demonstrates that the atmospheres of the weak G-band giants are not seriously contaminated with products of ON cycling.

  6. Giant Planets in Open Clusters

    NASA Astrophysics Data System (ADS)

    Quinn, S. N.; White, R. J.; Latham, D. W.

    2015-10-01

    Two decades after the discovery of 51 Peg b, more than 200 hot Jupiters have now been confirmed, but the details of their inward migration remain uncertain. While it is widely accepted that short period giant planets could not have formed in situ, several different mechanisms (e.g., Type II migration, planet-planet scattering, Kozai-Lidov cycles) may contribute to shrinking planetary orbits, and the relative importance of each is not well-constrained. Migration through the gas disk is expected to preserve circular, coplanar orbits and must occur quickly (within ˜ 10 Myr), whereas multi-body processes should initially excite eccentricities and inclinations and may take hundreds of millions of years. Subsequent evolution of the system (e.g., orbital circularization and inclination damping via tidal interaction with the host star) may obscure these differences, so observing hot Jupiters soon after migration occurs can constrain the importance of each mechanism. Fortunately, the well-characterized stars in young and adolescent open clusters (with known ages and compositions) provide natural laboratories for such studies, and recent surveys have begun to take advantage of this opportunity. We present a review of the discoveries in this emerging realm of exoplanet science, discuss the constraints they provide for giant planet formation and migration, and reflect on the future direction of the field.

  7. Corridor connecting giant panda habitats from north to south in the Min Mountains, Sichuan, China.

    PubMed

    Yin, Kaipu; Xie, Yan; Wu, Ning

    2006-12-01

    The giant panda faces severe threats from habitat fragmentation and isolation. Currently, giant panda populations have been fragmented into 30 habitat patches. The disappearance of isolated small populations and studies on the genetic diversity of various populations have shown that small isolated panda populations are at a high risk of dying out completely. Habitat fragmentation has seriously impaired the ability of the giant panda to resist climate changes and other natural disasters, such as large-scale, synchronous bamboo blooming. The Min Mountains have the largest population of pandas in China, numbering 581 individuals and accounting for 52% of the total (1114) in China. Geographic isolation means that giant pandas in the Min Mountains are divided into two populations (population A in the north and population B in the south). Population B, which had only 42 individuals in 1989, is severely threatened by high-density human populations and the loss of genetic diversity. However, we have identified an important corridor connecting the two populations. This paper explains the importance and the feasibility of reestablishing this corridor. Due to the special geographic locations of these two populations (two rivers block the migration of giant pandas between south and north), the corridor is the only passage for giant pandas in the region. Recent studies have also shown an increase of giant panda activity in the area of the corridor. However, vegetation in the corridor has been severely degraded. Bamboo forest must be restored in this area to provide food for the pandas during migration. The effects of human activities must be reduced in order to maintain panda habitat. We believe that a restored corridor will be of great benefit to the survival of giant pandas in the Min Mountains, especially for population B. Successful re-establishment of a corridor will be a valuable model for corridor construction in the future.

  8. Separating gas-giant and ice-giant planets by halting pebble accretion

    NASA Astrophysics Data System (ADS)

    Lambrechts, M.; Johansen, A.; Morbidelli, A.

    2014-12-01

    In the solar system giant planets come in two flavours: gas giants (Jupiter and Saturn) with massive gas envelopes, and ice giants (Uranus and Neptune) with much thinner envelopes around their cores. It is poorly understood how these two classes of planets formed. High solid accretion rates, necessary to form the cores of giant planets within the life-time of protoplanetary discs, heat the envelope and prevent rapid gas contraction onto the core, unless accretion is halted. We find that, in fact, accretion of pebbles (~cm sized particles) is self-limiting: when a core becomes massive enough it carves a gap in the pebble disc. This halt in pebble accretion subsequently triggers the rapid collapse of the super-critical gas envelope. Unlike gas giants, ice giants do not reach this threshold mass and can only bind low-mass envelopes that are highly enriched by water vapour from sublimated icy pebbles. This offers an explanation for the compositional difference between gas giants and ice giants in the solar system. Furthermore, unlike planetesimal-driven accretion scenarios, our model allows core formation and envelope attraction within disc life-times, provided that solids in protoplanetary discs are predominantly made up of pebbles. Our results imply that the outer regions of planetary systems, where the mass required to halt pebble accretion is large, are dominated by ice giants and that gas-giant exoplanets in wide orbits are enriched by more than 50 Earth masses of solids.

  9. An ecological basis for managing giant sequoia ecosystems.

    PubMed

    Piirto, Douglas D; Rogers, Robert R

    2002-07-01

    A strategy for management of giant sequoia groves is formulated using a conceptual framework for ecosystem management recently developed by Region Five of the USDA Forest Service. The framework includes physical, biological, and social dimensions. Environmental indicators and reference variability for key ecosystem elements are discussed in this paper. The selected ecosystem elements include: 1) attitudes, beliefs, and values; 2) economics and subsistence; 3) stream channel morphology; 4) sediment; 5) water; 6) fire; 7) organic debris; and 8) vegetation mosaic. Recommendations are made for the attributes of environmental indicators that characterize these elements. These elements and associated indicators will define and control management activities for the protection, preservation, and restoration of national forest giant sequoia ecosystems.

  10. Fecal hormones measured within giant Pacific octopuses Enteroctopus dofleini.

    PubMed

    Larson, Shawn E; Anderson, Roland C

    2010-09-01

    The captive husbandry of giant Pacific octopuses Enteroctopus dofleini is well understood, but their endocrine signatures are not well documented. The major vertebrate reproductive hormones--estrogen, progesterone, and testosterone--and the stress-related hormone corticosterone are relatively well known for many vertebrate species. However, few studies on these hormones within invertebrates have been conducted. Our hypothesis was that endocrine signatures within octopuses are similar to those found within vertebrates in response to reproductive activity and stress. Using standard immunoassay techniques, we measured fecal steroids within fecal samples collected from five female and three male giant Pacific octopuses housed at the Seattle Aquarium. The mean estrogen level ranged from 3.67 to 99.39 ng/g of feces, progesterone ranged from 44.35 to 231.71 ng/g feces, testosterone ranged from 9.30 to 18.18 ng/g feces, and corticosterone ranged from 10.91 to 22.14 ng/g feces. The results suggest that octopus fecal hormones are similar to those in vertebrates and may be useful in measuring ovarian activity and stress within captive female giant Pacific octopuses.

  11. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    SciTech Connect

    Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho . E-mail: keesh@korea.ac.kr

    2005-08-01

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear {beta}-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear {beta}-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3{beta} activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death.

  12. Detection of thermal radio emission from a single coronal giant

    NASA Astrophysics Data System (ADS)

    O'Gorman, E.; Harper, G. M.; Vlemmings, W.

    2017-02-01

    We report the detection of thermal continuum radio emission from the K0 III coronal giant Pollux (β Gem) with the Karl G. Jansky Very Large Array (VLA). The star was detected at 21 and 9 GHz with flux density values of 150 ± 21 and 43 ± 8 μJy, respectively. We also place a 3σrms upper limit of 23 μJy for the flux density at 3 GHz. We find the stellar disk-averaged brightness temperatures to be approximately 9500, 15 000, and <71 000 K, at 21, 9, and 3 GHz, respectively, which are consistent with the values of the quiet Sun. The emission is most likely dominated by optically thick thermal emission from an upper chromosphere at 21 and 9 GHz. We discuss other possible additional sources of emission at all frequencies and show that there may also be a small contribution from gyroresonance emission above active regions, coronal free-free emission and free-free emission from an optically thin stellar wind, particularly at the lower frequencies. We constrain the maximum mass-loss rate from Pollux to be less than 3.7 × 10-11M⊙ yr-1 (assuming a wind terminal velocity of 215 km s-1), which is about an order of magnitude smaller than previous constraints for coronal giants and is in agreement with existing predictions for the mass-loss rate of Pollux. These are the first detections of thermal radio emission from a single (i.e., non-binary) coronal giant and demonstrate that low activity coronal giants like Pollux have atmospheres at radio frequencies akin to the quiet Sun.

  13. Deep Biosphere Secrets of the Mediterranean Salt Giant

    NASA Astrophysics Data System (ADS)

    Aloisi, Giovanni; Lugli, Stefano; McGenity, Terry; Kuroda, Junichiro; Takai, Ken; Treude, Tina; Camerlenghi, Angelo

    2015-04-01

    One component of the IODP multi-platform drilling proposal called DREAM (Deep-Sea Record of Mediterranean Messisnian Events), plans to investigate the deep biosphere associated to the Messinian Salinity Crisis (MSC) Salt Giant. We propose that the MSC Salt Giant, because of the variety of chemical environments it produces, has the potential to harbour an unprecedented diversity of microbial life with exceptional metabolic activity. Gypsum and anhydrite deposits provide a virtually unlimited source of sulphate at depths where oxidants are a rarity in other sedimentary environments. When reduced organic carbon comes into contact with these minerals there is the potential for a dynamic deep biosphere community of sulphate reducers to develop, with implications for sedimentary biogeochemical cycles and the souring of cruide oil. But the thickness of the Messinian evaporites and the range of chemical environments it harbours poses fundamental questions: will the interaction of several extreme conditions of temperature, salinity, pressure and chemical composition limit the ability of microbes to take advantage of such favourable thermodynamic conditions? And has such a diverse set of physical and chemical environments fostered microbal diversity, rather than phylogenetic specialization, as recent research into deep Mediterranean brine systems seems to indicate ? Over three kilometres in thickness, approaching the known temperature limits of life and with fluids precipitating carbonate, sulphate, halite and potash salts, microbes living within and around the MSC Salt Giant will be subject to the most exotic combinations of extremes, and have likely evolved yet unknown adaptations. Gypsum and Halite crystals contain fluid inclusions that are a micro-habitat in which microbes survive for tens of thousands, to possibly millions, of years, posing the fundamental question of cells devoting nearly all of their energy flow to somatic maintenance needs, rather than growth and

  14. Giant tunneling magnetoresistance in silicene

    SciTech Connect

    Wang, Yu; Lou, Yiyi

    2013-11-14

    We have theoretically studied ballistic electron transport in silicene under the manipulation of a pair of ferromagnetic gate. Transport properties like transmission and conductance have been calculated by the standard transfer matrix method for parallel and antiparallel magnetization configurations. It is demonstrated here that, due to the stray field-induced wave-vector filtering effect, remarkable difference in configuration-dependent transport gives rise to a giant tunneling magnetoresistance. In combination with the peculiar buckled structure of silicene and its electric tunable energy gap, the receiving magnetoresistance can be efficiently modulated by the externally-tunable stray field, electrostatic potential, and staggered sublattice potential, providing some flexible strategies to construct silicene-based nanoelectronic device.

  15. [Endovascular treatment of giant intracranial aneurysms].

    PubMed

    Bracard, S; Derelle, A L; Tonnelet, R; Barbier, C; Proust, F; Anxionnat, R

    2016-02-01

    Giant aneurysms are defined as having a maximal diameter higher than 25mm. The dynamic aspect of giant aneurysms, in particular, is its growth, which was responsible for parenchyma sequellae either due to haemorrhagic complications or a compression of cranial nerves. The treatment of these giant aneurysms was challenging because of its size, the mass effect and the neck diameter. These morphologic conditions required complex endovascular procedures such as remodelling, stenting, using flow diverters. Subsequently, the complex procedures increased the risk of morbidity because of ischemic complications. Despite these procedures, the risk of recurrence was high.

  16. SYNOVIAL GIANT CELL TUMOR OF THE KNEE.

    PubMed

    Abdalla, Rene Jorge; Cohen, Moisés; Nóbrega, Jezimar; Forgas, Andrea

    2009-01-01

    Synovial giant cell tumor is a benign neoplasm, rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs on the hand, and, most uncommon, on the ankle and knee. In the present study, the authors describe a rare case of synovial giant cell tumor on the knee as well as the treatment approach. Arthroscopy has been shown, in this case, to be the optimal method for treating this kind of lesion, once it allowed a less aggressive approach, while providing good visualization of all compartments of knee joint and full tumor resection.

  17. Idiopathic Giant Cell Myocarditis: A Case Report

    PubMed Central

    Kumari M.K., Kalpana; Mysorekar, Vijaya V.; S., Praveen

    2012-01-01

    Giant-cell myocarditis is a disease of relatively young, predominantly healthy adults. The patients usually die of heart failure and ventricular arrhythmia unless a cardiac transplantation is performed. We are reporting here an autopsy case of idiopathic giant cell myocarditis with no symptoms in a 27-year old -worker who died suddenly. The purpose of this report was to emphasize that idiopathic giant cell myocarditis was a rare disease and that it could exist in the absence of any symptomatic heart disease. PMID:23205365

  18. A giant pancreatic pseudocyst treated by cystogastrostomy

    PubMed Central

    Wang, Grace C; Misra, Subhasis

    2015-01-01

    We report a case of a giant pancreatic pseudocyst in a 65-year-old man presenting with abdominal pain, loss of appetite and abdominal distension. CT scans demonstrated a giant pancreatic pseudocyst measuring 25.7 cm×15.3 cm×10.9 cm anteroposteriorly, with significant compression of surrounding organs. An open cystogastrostomy was performed through a midline incision, and 3 L of fluid was drained from the giant pseudocyst. Recovery has been uneventful. PMID:25804943

  19. Rotation and macroturbulence in bright giants

    SciTech Connect

    Gray, D.F.; Toner, C.G.

    1986-11-01

    Spectral line profiles of 35 F, G, and K bright giants were analyzed to obtain rotation rates, v sin i, and macroturbulence dispersion. This sample indicates that rotation rates of cool class II giants is less than 11 km/s, in contrast with some recent periodicity measurements. Macroturbulence dispersion generally increases with effective temperature, but the range of values at a given effective temperature is much larger than seen for lower luminosity classes; this is interpreted in terms of red-giant and blue-loop evolution. No evidence is found for angular momentum dissipation on the first crossing of the H-R diagram. 57 references.

  20. SYNOVIAL GIANT CELL TUMOR OF THE KNEE

    PubMed Central

    Abdalla, Rene Jorge; Cohen, Moisés; Nóbrega, Jezimar; Forgas, Andrea

    2015-01-01

    Synovial giant cell tumor is a benign neoplasm, rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs on the hand, and, most uncommon, on the ankle and knee. In the present study, the authors describe a rare case of synovial giant cell tumor on the knee as well as the treatment approach. Arthroscopy has been shown, in this case, to be the optimal method for treating this kind of lesion, once it allowed a less aggressive approach, while providing good visualization of all compartments of knee joint and full tumor resection. PMID:27004193

  1. Rapidly Developing Yeast Microcolonies Differentiate in a Similar Way to Aging Giant Colonies

    PubMed Central

    Váchová, Libuše; Hatáková, Ladislava; Čáp, Michal; Pokorná, Michaela; Palková, Zdena

    2013-01-01

    During their development and aging on solid substrates, yeast giant colonies produce ammonia, which acts as a quorum sensing molecule. Ammonia production is connected with alkalization of the surrounding medium and with extensive reprogramming of cell metabolism. In addition, ammonia signaling is important for both horizontal (colony centre versus colony margin) and vertical (upper versus lower cell layers) colony differentiations. The centre of an aging differentiated giant colony is thus composed of two major cell subpopulations, the subpopulation of long-living, metabolically active and stress-resistant cells that form the upper layers of the colony and the subpopulation of stress-sensitive starving cells in the colony interior. Here, we show that microcolonies originating from one cell pass through similar developmental phases as giant colonies. Microcolony differentiation is linked to ammonia signaling, and cells similar to the upper and lower cells of aged giant colonies are formed even in relatively young microcolonies. A comparison of the properties of these cells revealed a number of features that are similar in microcolonies and giant colonies as well as a few that are only typical of chronologically aged giant colonies. These findings show that colony age per se is not crucial for colony differentiation. PMID:23970946

  2. Direct Imaging of Giant Exoplanets

    NASA Astrophysics Data System (ADS)

    Tamura, Motohide

    Since the first detection of exoplanets around a Sun-like star 51 Peg in 1995, their detection and characterization are mainly led by indirect methods such as radial velocity and transit methods. However, recent progresses of observational techniques have finally enabled the direct imaging observations of giant planets of solar-system-scale orbit (with their semi-major axes less than about 50 AU) around A-type stars (e.g., Marois et al. 2008, 2010) and G-type stars (e.g., Kuzuhara et al. 2013). Direct imaging is useful to obtain the physical and atmospheric parameters of exoplanets. In fact not only colors but also a medium-resolution spectroscopy of such planets has been successfully obtained for their atmospheric characterization (Barman et al. 2013). Their masses are typically a few to ~10 Jupiter masses and they orbit at a Saturn- to-Pluto distance. Therefore, like hot-Jupiters and super-Earths they are unlike any solar-system planets, and called wide-orbit giant planets. A recent large search for planets and disk on the Subaru 8.2-m telescope (SEEDS project) has detected a 3-5 Jupiter-masses planet around a Sun-like star GJ 504 (Kuzuhara et al. 2013). It is the coolest planetary companion so far directly imaged and its near-infrared color is “bluer” than that of other directly imaged planets. In this contribution, I will review the recent progresses on direct imaging of exoplanets, highlight the results of the SEEDS project, and discuss the future developments.

  3. Giant gastrointestinal stromal tumor of the stomach.

    PubMed

    Ionescu, Sever; Barbu, Emil; Ionescu, Călin; Costache, Adrian; Bălăşoiu, Maria

    2015-01-01

    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies of the digestive tract. Gastric localization is the most frequent. The aim of this study is to evaluate the importance of immunohistochemical factors (CD117, CD34, α-SMA, vimentin, p53, Ki67) in diagnostic and size tumor and mitotic activity as prognostic factors for these tumors. We present the case of a 66-year-old male patient with a giant gastric GIST. Like in the vast majority, the symptomatology in this patient has long been faint, despite the large tumor size, and when it became manifest, it was nonspecific. Imagery wise, the computer tomography (CT) scan was the most efficient, showing the origin of the tumor from the greater curvature of the stomach, its dimensions, as well as the relations with the other abdominal viscera. Surgery in this patient was en-bloc, according to the principles of GIST. The histological aspect is characterized by a proliferation of spindle cells positive for CD117 and CD34. Despite complete microscopic resection, the size of the tumor (25×20×27 cm) and the mitotic activity (21÷5 mm2) remains important relapse factor.

  4. Functional annotation from the genome sequence of the giant panda.

    PubMed

    Huo, Tong; Zhang, Yinjie; Lin, Jianping

    2012-08-01

    The giant panda is one of the most critically endangered species due to the fragmentation and loss of its habitat. Studying the functions of proteins in this animal, especially specific trait-related proteins, is therefore necessary to protect the species. In this work, the functions of these proteins were investigated using the genome sequence of the giant panda. Data on 21,001 proteins and their functions were stored in the Giant Panda Protein Database, in which the proteins were divided into two groups: 20,179 proteins whose functions can be predicted by GeneScan formed the known-function group, whereas 822 proteins whose functions cannot be predicted by GeneScan comprised the unknown-function group. For the known-function group, we further classified the proteins by molecular function, biological process, cellular component, and tissue specificity. For the unknown-function group, we developed a strategy in which the proteins were filtered by cross-Blast to identify panda-specific proteins under the assumption that proteins related to the panda-specific traits in the unknown-function group exist. After this filtering procedure, we identified 32 proteins (2 of which are membrane proteins) specific to the giant panda genome as compared against the dog and horse genomes. Based on their amino acid sequences, these 32 proteins were further analyzed by functional classification using SVM-Prot, motif prediction using MyHits, and interacting protein prediction using the Database of Interacting Proteins. Nineteen proteins were predicted to be zinc-binding proteins, thus affecting the activities of nucleic acids. The 32 panda-specific proteins will be further investigated by structural and functional analysis.

  5. Lithium Abundance in M3 Red Giant

    NASA Astrophysics Data System (ADS)

    Givens, Rashad; Pilachowski, Catherine A.

    2015-01-01

    We present the abundance of lithium in the red giant star vZ 1050 (SK 291) in the globular cluster M3. A previous survey of giants in the cluster showed that like IV-101, vZ 1050 displays a prominent Li I 6707 Å feature. vZ 1050 lies on the blue side of the red giant branch about 1.3 magnitudes above the level of the horizontal branch, and may be an asymptotic giant branch star. A high resolution spectrum of M3 vZ1050 was obtained with the ARC 3.5m telescope and the ARC Echelle Spectrograph (ARCES). Atmospheric parameters were determined using Fe I and Fe II lines from the spectrum using the MOOG spectral analysis program, and the lithium abundance was determined using spectrum synthesis.

  6. Giant cell arteritis presenting as scalp necrosis.

    PubMed

    Maidana, Daniel E; Muñoz, Silvia; Acebes, Xènia; Llatjós, Roger; Jucglà, Anna; Alvarez, Alba

    2011-07-07

    The differential of scalp ulceration in older patients should include several causes, such as herpes zoster, irritant contact dermatitis, ulcerated skin tumors, postirradiation ulcers, microbial infections, pyoderma gangrenosum, and giant cell arteritis. Scalp necrosis associated with giant cell arteritis was first described in the 1940s. The presence of this dermatological sign within giant cell arteritis represents a severity marker of this disease, with a higher mean age at diagnosis, an elevated risk of vision loss and tongue gangrene, as well as overall higher mortality rates, in comparison to patients not presenting this manifestation. Even though scalp necrosis due to giant cell arteritis is exceptional, a high level of suspicion must be held for this clinical finding, in order to initiate prompt and proper treatment and avoid blindness.

  7. Mass loss in red giants and supergiants

    NASA Technical Reports Server (NTRS)

    Sanner, F.

    1975-01-01

    The circumstellar envelopes surrounding late-type giants and supergiants were studied using high resolution, photoelectric scans of strong optical resonance lines. A method for extracting the circumstellar from the stellar components of the lines allowed a quantitative determination of the physical conditions in the envelopes and the rates of mass loss at various positions in the red giant region of the HR diagram. The observed strengthening of the circumstellar spectrum with increasing luminosity and later spectral type is probably caused by an increase in the mass of the envelopes. The mass loss rate for individual stars is proportional to the visual luminosity; high rates for the supergiants suggest that mass loss is important in their evolution. The bulk of the mass return to the interstellar medium in the red giant region comes from the normal giants, at a rate comparable to that of planetary nebulae.

  8. "GIANT" Steps to Create Online Orientations

    ERIC Educational Resources Information Center

    Bacon, Pamela

    2005-01-01

    Online orientation is provided due to the flexibility of online learning. The online orientation consists of the GIANT steps which stands for Get support, Identify your curriculum, Assemble your program, Navigate students through the pilot project and Test students.

  9. Tests of the Giant Impact Hypothesis

    NASA Technical Reports Server (NTRS)

    Jones, J. H.

    1998-01-01

    The giant impact hypothesis has gained popularity as a means of explaining a volatile-depleted Moon that still has a chemical affinity to the Earth. As Taylor's Axiom decrees, the best models of lunar origin are testable, but this is difficult with the giant impact model. The energy associated with the impact would be sufficient to totally melt and partially vaporize the Earth. And this means that there should he no geological vestige of Barber times. Accordingly, it is important to devise tests that may be used to evaluate the giant impact hypothesis. Three such tests are discussed here. None of these is supportive of the giant impact model, but neither do they disprove it.

  10. Giant salivary calculi of the submandibular gland

    PubMed Central

    Fowell, C; MacBean, A

    2012-01-01

    Sialolithasis is the most common salivary gland disease. A case of an unusually large sialolith arising in the submandibular gland is presented, along with a review of the management of giant salivary gland calculi. PMID:24960792

  11. The behavior and release of methane related to hydrates in a pockmark area in the eastern margin of the Japan Sea: An approach from chlorine isotope composition in pore water and sea water

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Satake, H.; Takeuchi, A.; Gamo, T.

    2006-12-01

    Methane released from the seafloor is a strong contributor to the greenhouse gas budget. Some deposits of methane hydrates existing in ocean sediment are linked to plate collision/subduction boundaries and associated tectonic motion. Methane plumes were observed in the pockmark area off Sado, at the end of the eastern margin of the Japan Sea where the North American and Eurasian tectonic plates intersect. Our goal in this study is to investigate the origin of methane and its actual release mechanisms from the seafloor and its behavior and seasonal variation in the water column by using chemical oceanic observations and geochemical analysis of pore water and sea waters. Geochemical data sets are from five cruises over two years and three seasons. The KT05-11 and KT06-26 expeditions were on the R/V Tansei-Maru, NA220 on the T/S Nagasaki-Maru, and the NT05-10 and NT06-19 expeditions using the unmanned submersible HYPER-DOLPHIN and its mother-ship R/V Natsushima. Results of chlorine and oxygen isotope compositions and other water chemical characteristics indicate that methane hydrate is generated over the bottom and is then melted in the shallow water. The possible processes are: 1) In deep water, chlorine isotope composition shows inverse correlation with oxygen, which suggests the fine particles of methane hydrate are adhering to the surface of gas bubbles released from deep sediment together with cold seep; the methane hydrate particles possibly grow and expand above the bottom and rise in water column. 2) In shallower water mass (< 300m depth), the amount of fresh water accumulated hints that fresh water is derived from the melting of methane hydrate and contributes up to 3% of the amount calculated by the decrease in upper-water salinity; this implies that a corresponding amount of methane was transported to ocean surface. The seasonal variations of dissolved methane and other chemical features in shallow water are possibly affected by the methane-oxidation and

  12. Arterial Embolization of Giant Hepatic Hemangiomas

    SciTech Connect

    Giavroglou, Constantinos; Economou, Hippolete; Ioannidis, Ioannis

    2003-02-15

    Hepatic cavernous hemangiomas are usually small and asymptomatic. They are usually discovered incidentally and only a few require treatment. However, giant hemangiomas may cause symptoms,which are indications for treatment. We describe four cases of symptomatic giant hepatic hemangiomas successfully treated with transcatheter arterial embolization, performed with polyvinyl alcohol particles. There were no complications. Follow-up with clinical and imaging examinations showed disappearance of symptoms and decrease in size of lesions.

  13. Bayesian Inference of Giant Exoplanet Physics

    NASA Astrophysics Data System (ADS)

    Thorngren, Daniel; Fortney, Jonathan J.

    2017-01-01

    The physical processes within a giant planet directly set its observed radius for a given mass, age, and insolation. The important aspects are the planet’s bulk composition and its interior thermal evolution. By studying many giant planets as an ensemble, we can gain insight into this physics. We demonstrate two novel examples here. We examine 50 cooler transiting giant planets, whose insolation is sufficiently low (T_eff < 1000 K) that they are not affected by the hot Jupiter radius inflation effect. For these planets, the thermal evolution is relatively well understood, and we show that the bulk planet metallicity increases with the total planet mass, which directly impacts plans for future atmospheric studies. We also examine the relation with stellar metallicity and discuss how these relations place new constraints on the core accretion model of planet formation. Our newest work seeks to quantify the flow of energy into hot Jupiters needed to explain their enlarged radii, in addition to their bulk composition. Because the former is related to stellar insolation and the latter is related to mass, we are able to create a hierarchical Bayesian model to disentangle the two effects in our sample of ~300 transiting giant planets. Our results show conclusively that the inflation power is not a simple fraction of stellar insolation: instead, the power increases with incident flux at a much higher rate. We use these results to test published models of giant planet inflation and to provide accurate empirical mass-radius relations for giant planets.

  14. Formation of Giant Planets and Brown Dwarves

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2003-01-01

    According to the prevailing core instability model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models predict that rocky planets should form in orbit about most stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. Ongoing theoretical modeling of accretion of giant planet atmospheres, as well as observations of protoplanetary disks, will help decide this issue. Observations of extrasolar planets around main sequence stars can only provide a lower limit on giant planet formation frequency . This is because after giant planets form, gravitational interactions with material within the protoplanetary disk may cause them to migrat inwards and be lost to the central star. The core instability model can only produce planets greater than a few jovian masses within protoplanetary disks that are more viscous than most such disks are believed to be. Thus, few brown dwarves (objects massive enough to undergo substantial deuterium fusion, estimated to occur above approximately 13 jovian masses) are likely to be formed in this manner. Most brown dwarves, as well as an unknown number of free-floating objects of planetary mass, are probably formed as are stars, by the collapse of extended gas/dust clouds into more compact objects.

  15. Management of giant liver hemangiomas: an update.

    PubMed

    Hoekstra, Lisette T; Bieze, Matthanja; Erdogan, Deha; Roelofs, Joris J T H; Beuers, Ulrich H W; van Gulik, Thomas M

    2013-03-01

    Liver hemangiomas are the most common benign liver tumors and are usually incidental findings. Liver hemangiomas are readily demonstrated by abdominal ultrasonography, computed tomography or magnetic resonance imaging. Giant liver hemangiomas are defined by a diameter larger than 5 cm. In patients with a giant liver hemangioma, observation is justified in the absence of symptoms. Surgical resection is indicated in patients with abdominal (mechanical) complaints or complications, or when diagnosis remains inconclusive. Enucleation is the preferred surgical method, according to existing literature and our own experience. Spontaneous or traumatic rupture of a giant hepatic hemangioma is rare, however, the mortality rate is high (36-39%). An uncommon complication of a giant hemangioma is disseminated intravascular coagulation (Kasabach-Merritt syndrome); intervention is then required. Herein, the authors provide a literature update of the current evidence concerning the management of giant hepatic hemangiomas. In addition, the authors assessed treatment strategies and outcomes in a series of patients with giant liver hemangiomas managed in our department.

  16. Giant crystals inside mitochondria of equine chondrocytes.

    PubMed

    Nürnberger, S; Rentenberger, C; Thiel, K; Schädl, B; Grunwald, I; Ponomarev, I; Marlovits, St; Meyer, Ch; Barnewitz, D

    2016-12-24

    The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 1-2 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It is elongated, spanning a length of several micrometres through the whole cell. In some chondrocytes, several crystals were found, sometimes combined in a single mitochondrion. Crystals were preferentially aligned along the long axis of the cells, thus appearing in the same orientation as the chondrocytes in the tissue. Although no similar structures have been found in the cartilage of any other species investigated, they have been found in cartilage repair tissue formed within a mechanically stimulated equine chondrocyte construct. Crystals were mainly located in superficial regions of cartilage, especially in joint regions of well-developed superficial layers, more often in yearlings than in adult horses. These results indicate that intramitochondrial crystals are related to the high mechanical stress in the horse joint and potentially also to the increased metabolic activity of immature individuals.

  17. Refined contour analysis of giant unilamellar vesicles

    NASA Astrophysics Data System (ADS)

    Pécréaux, J.; Döbereiner, H.-G.; Prost, J.; Joanny, J.-F.; Bassereau, P.

    2004-03-01

    The fluctuation spectrum of giant unilamellar vesicles is measured using a high-resolution contour detection technique. An analysis at higher q vectors than previously achievable is now possible due to technical improvements of the experimental setup and of the detection algorithm. The global fluctuation spectrum is directly fitted to deduce the membrane tension and the bending modulus of lipid membranes. Moreover, we show that the planar analysis of fluctuations is valid for spherical objects, even at low wave vectors. Corrections due to the integration time of the video camera and to the section of a 3D object by the observation plane are introduced. A precise calculation of the error bars has been done in order to provide reliable error estimate. Eventually, using this technique, we have measured bending moduli for EPC, SOPC and \\chem{SOPC:CHOL} membranes confirming previously published values. An interesting application of this technique can be the measurement of the fluctuation spectra for non-equilibrium membranes, such as “active membranes”.

  18. Giant cell arteritis: Current treatment and management

    PubMed Central

    Ponte, Cristina; Rodrigues, Ana Filipa; O’Neill, Lorraine; Luqmani, Raashid Ahmed

    2015-01-01

    Glucocorticoids remain the cornerstone of medical therapy in giant cell arteritis (GCA) and should be started immediately to prevent severe consequences of the disease, such as blindness. However, glucocorticoid therapy leads to significant toxicity in over 80% of the patients. Various steroid-sparing agents have been tried, but robust scientific evidence of their efficacy and safety is still lacking. Tocilizumab, a monoclonal IL-6 receptor blocker, has shown promising results in a number of case series and is now being tested in a multi-centre randomized controlled trial. Other targeted treatments, such as the use of abatacept, are also now under investigation in GCA. The need for surgical treatment is rare and should ideally be performed in a quiescent phase of the disease. Not all patients follow the same course, but there are no valid biomarkers to assess therapy response. Monitoring of disease progress still relies on assessing clinical features and measuring inflammatory markers (C-reactive protein and erythrocyte sedimentation rate). Imaging techniques (e.g., ultrasound) are clearly important screening tools for aortic aneurysms and assessing patients with large-vessel involvement, but may also have an important role as biomarkers of disease activity over time or in response to therapy. Although GCA is the most common form of primary vasculitis, the optimal strategies for treatment and monitoring remain uncertain. PMID:26090367

  19. Biomass yield comparisons of giant miscanthus, giant reed, and miscane grown under irrigated and rainfed conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Department of Energy has initiated efforts to decrease the nation’s dependence on imported oil by developing domestic renewable sources of cellulosic-derived bioenergy. In this study, giant miscanthus (Miscanthus x giganteus), sugarcane (complex hybrid of Saccharum spp.), and giant reed (Ar...

  20. Migration of accreting giant planets

    NASA Astrophysics Data System (ADS)

    Crida, A.; Bitsch, B.; Raibaldi, A.

    2016-12-01

    We present the results of 2D hydro simulations of giant planets in proto-planetary discs, which accrete gas at a more or less high rate. First, starting from a solid core of 20 Earth masses, we show that as soon as the runaway accretion of gas turns on, the planet is saved from type I migration : the gap opening mass is reached before the planet is lost into its host star. Furthermore, gas accretion helps opening the gap in low mass discs. Consequently, if the accretion rate is limited to the disc supply, then the planet is already inside a gap and in type II migration. We further show that the type II migration of a Jupiter mass planet actually depends on its accretion rate. Only when the accretion is high do we retrieve the classical picture where no gas crosses the gap and the planet follows the disc spreading. These results impact our understanding of planet migration and planet population synthesis models. The e-poster presenting these results in French can be found here: L'e-poster présentant ces résultats en français est disponible à cette adresse: http://sf2a.eu/semaine-sf2a/2016/posterpdfs/156_179_49.pdf.

  1. A giant thunderstorm on Saturn.

    PubMed

    Fischer, G; Kurth, W S; Gurnett, D A; Zarka, P; Dyudina, U A; Ingersoll, A P; Ewald, S P; Porco, C C; Wesley, A; Go, C; Delcroix, M

    2011-07-06

    Lightning discharges in Saturn's atmosphere emit radio waves with intensities about 10,000 times stronger than those of their terrestrial counterparts. These radio waves are the characteristic features of lightning from thunderstorms on Saturn, which last for days to months. Convective storms about 2,000 kilometres in size have been observed in recent years at planetocentric latitude 35° south (corresponding to a planetographic latitude of 41° south). Here we report observations of a giant thunderstorm at planetocentric latitude 35° north that reached a latitudinal extension of 10,000 kilometres-comparable in size to a 'Great White Spot'-about three weeks after it started in early December 2010. The visible plume consists of high-altitude clouds that overshoot the outermost ammonia cloud layer owing to strong vertical convection, as is typical for thunderstorms. The flash rates of this storm are about an order of magnitude higher than previous ones, and peak rates larger than ten per second were recorded. This main storm developed an elongated eastward tail with additional but weaker storm cells that wrapped around the whole planet by February 2011. Unlike storms on Earth, the total power of this storm is comparable to Saturn's total emitted power. The appearance of such storms in the northern hemisphere could be related to the change of seasons, given that Saturn experienced vernal equinox in August 2009.

  2. Atmospheres of the Giant Planets

    NASA Technical Reports Server (NTRS)

    Ingersoll, Andrew P.

    2002-01-01

    The giant planets, Jupiter, Saturn, Uranus, and Neptune, are fluid objects. They have no solid surfaces because the light elements constituting them do not condense at solar-system temperatures. Instead, their deep atmospheres grade downward until the distinction between gas and liquid becomes meaningless. The preceding chapter delved into the hot, dark interiors of the Jovian planets. This one focuses on their atmospheres, especially the observable layers from the base of the clouds to the edge of space. These veneers arc only a few hundred kilometers thick, less than one percent of each planet's radius, but they exhibit an incredible variety of dynamic phenomena. The mixtures of elements in these outer layers resemble a cooled-down piece of the Sun. Clouds precipitate out of this gaseous soup in a variety of colors. The cloud patterns are organized by winds, which are powered by heat derived from sunlight (as on Earth) and by internal heat left over from planetary formation. Thus the atmospheres of the Jovian planets are distinctly different both compositionally and dynamically from those of the terrestrial planets. Such differences make them fascinating objects for study, providing clues about the origin and evolution of the planets and the formation of the solar system.

  3. Treatment of Giant Intracranial Aneurysms

    PubMed Central

    Lv, X.; Jiang, C.; Li, Y.; Yang, X.; Zhang, J.; Wu, Z.

    2009-01-01

    Summary We report on report the clinical outcome obtained in treatment of giant intracranial aneurysms (GAs). Between 2005 and 2007, 51 patients with 51 GAs presented at our hospital. Twentynine were treated with primary parent vessel occlusion without distal bypass and ten underwent treatment preserving the parent artery. Twelve patients could not be treated endovascularly. Selective embolization (including two remodeling techniques and two stent-coil embolizations) resulted in only one cure. Two patients died as a result of subarachnoid hemorrhage periprocedurely. Twenty-nine patients treated primarily with parent vessel occlusion and three patients treated with covered stent were considered cured after their treatments. Only one patient treated with parent vessel occlusion experienced ischemia during follow-up, which resulted in a mild neurological deficit. Of the twelve patients who could not be treated endovascularly, one succumbed to surgery, four died while being treated conservatively, and three were lost to follow-up. Parent artery occlusion, covered stent and coil occlusion provide effective protection against bleeding. In treatment of paraclinoid GAs of the internal carotid artery, the use of a stent, and stent-assisted coil embolization may be a pitfall. PMID:20465907

  4. Giant electrocaloric effect around Tc.

    PubMed

    Rose, Maimon C; Cohen, R E

    2012-11-02

    We use molecular dynamics with a first-principles-based shell model potential to study the electrocaloric effect (ECE) in lithium niobate, LiNbO(3), and find a giant electrocaloric effect along a line passing through the ferroelectric transition. With an applied electric field, a line of maximum ECE passes through the zero field ferroelectric transition, continuing along a Widom line at high temperatures with increasing fields, and along the instability that leads to homogeneous ferroelectric switching below T(c) with an applied field antiparallel to the spontaneous polarization. This line is defined as the minimum in the inverse capacitance under an applied electric field. We investigate the effects of pressure, temperature and an applied electric field on the ECE. The behavior we observe in LiNbO(3) should generally apply to ferroelectrics; we therefore suggest that the operating temperature for refrigeration and energy scavenging applications should be above the ferroelectric transition region to obtain a large electrocaloric response. The relationship between T(c), the Widom line, and homogeneous switching should be universal among ferroelectrics, relaxors, multiferroics, and the same behavior should be found under applied magnetic fields in ferromagnets.

  5. Red Giant Plunging Through Space

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Poster Version

    This image from NASA's Spitzer Space Telescope (left panel) shows the 'bow shock' of a dying star named R Hydrae, or R Hya, in the constellation Hydra.

    Bow shocks are formed where the stellar wind from a star are pushed into a bow shape (illustration, right panel) as the star plunges through the gas and dust between stars. Our own Sun has a bow shock, but prior to this image one had never been observed around this particular class of red giant star.

    R Hya moves through space at approximately 50 kilometers per second. As it does so, it discharges dust and gas into space. Because the star is relatively cool, that ejecta quickly assumes a solid state and collides with the interstellar medium. The resulting dusty nebula is invisible to the naked eye but can be detected using an infrared telescope. This bow shock is 16,295 astronomical units from the star to the apex and 6,188 astronomical units thick (an astronomical unit is the distance between the sun and Earth). The mass of the bow shock is about 400 times the mass of the Earth.

    The false-color Spitzer image shows infrared emissions at 70 microns. Brighter colors represent greater intensities of infrared light at that wavelength. The location of the star itself is drawn onto the picture in the black 'unobserved' region in the center.

  6. Giant resonances of endohedral atoms

    NASA Astrophysics Data System (ADS)

    Amusia, M. Ya.; Baltenkov, A. S.; Chernysheva, L. V.

    2008-04-01

    It is demonstrated for the first time that the effect of a fullerene shell on the photoionization of a “caged” atom in an endohedral can result in the formation of giant endohedral resonances or GER. This is illustrated by the concrete case of the Xe@C60 photoionization cross section that, at 17 eV, exhibits a powerful resonance with total oscillator strengths of about 25. The prominent modification of the 5 p 6 electron photoionization cross section of Xe@C60 takes place due to the strong fullerene shell polarization under the action of the incoming electromagnetic wave and the oscillation of this cross section due to the reflection of the photoelectron from Xe by the C60. These two factors transform the smoothly decreasing 5 p 6 cross section of Xe into a rather complex curve with a powerful maximum for Xe@C60, with the oscillator strength of it being equal to 25. We also present the results for the dipole angular anisotropy parameter that is strongly affected by the reflection of the photoelectron waves, but not modified by C60 polarization.

  7. Giant resonances of endohedral atoms

    NASA Astrophysics Data System (ADS)

    Amusia, M. Ya.; Baltenkov, Arkadiy; Chernysheva, Larissa

    2008-05-01

    We demonstrate for that the effect of fullerene shell upon photoionization of the ``caged'' atom in an endohedral can result in formation of Giant Endohedral Resonances or GER. This is illustrated by the concrete case of Xe@C60 photoionization cross-section that exhibits at 17 eV a powerful resonance with total oscillator strengths of about 25. The prominent modification of the 5p^6 electron photoionization cross-section of Xe@C60 takes place due to strong fullerene shell polarization under the action of the incoming electromagnetic wave and oscillation of this cross-section due to the reflection of the photoelectron from Xe by the C60. These two factors transform the smoothly decreasing 5p^6 cross-section of Xe into a rather complex curve with a powerful maximum for Xe@C60, with the oscillator strength of it being equal to 25! We present also the results for the dipole angular anisotropy parameter that is strongly affected by the reflection of the photoelectron waves but not modified by C60 polarization.

  8. Radiological and Histopathological Outcome of Giant Cell Tumor of Femur with Denosumab Treatment: A Case Report

    PubMed Central

    Krishnakumar, R.; Jojo, Annie

    2016-01-01

    Giant Cell Tumour of Bone (GCTB) is a benign but locally aggressive osteolytic skeletal neoplasm of young adults consisting of giant cells expressing RANK (Receptor Activator of Nuclear Factor-κB) and mesenchymal spindle-like stromal cells expressing RANKL (RANK ligand). The interaction of these cells leads to bone resorption. Recently, the RANKL inhibitor, denosumab, has demonstrated activity against giant-cell tumours. The current article reports a case of a Giant cell tumour of left distal femur with pathological fracture. A 34-year-old male patient presented with history of on and off dull aching pain in the left knee for 4 months followed by a history of trivial fall. He sustained a closed injury in the left knee, following which he was unable to bear weight and developed pain and swelling in left knee. Conventional radiographs and Computerized tomography (CT) was done which showed the presence of a left distal femoral osteolytic lesion and a histological analysis of a biopsy specimen confirmed the diagnosis of GCTB. The patient was treated with neoadjuvant denosumab therapy which resulted in successful downstaging of the tumour followed by extended curettage of the lesion with high speed burr and argon laser cautery. The post-curettage microscopic examination revealed the absence of osteoclast-type giant cells. PMID:28208958

  9. The potential for giant tsunamigenic earthquakes in the northern Bay of Bengal.

    PubMed

    Cummins, Phil R

    2007-09-06

    The great Sumatra-Andaman earthquake and Indian Ocean tsunami of 2004 came as a surprise to most of the earth science community. Although it is now widely recognized that the risk of another giant earthquake is high off central Sumatra, just east of the 2004 earthquake, there seems to be relatively little concern about the subduction zone to the north, in the northern Bay of Bengal along the coast of Myanmar. Here I show that similar indicators suggest a high potential for giant earthquakes along the coast of Myanmar. These indicators include the tectonic environment, which is similar to other subduction zones that experience giant megathrust earthquakes, stress and crustal strain observations, which indicate that the seismogenic zone is locked, and historical earthquake activity, which indicates that giant tsunamigenic earthquakes have occurred there in the past. These are all consistent with active subduction in the Myanmar subduction zone and I suggest that the seismogenic zone extends beneath the Bengal Fan. I conclude therefore that giant earthquakes probably occur off the coast of Myanmar, and that a large and vulnerable population is thereby exposed to a significant earthquake and tsunami hazard.

  10. The "Giant Virus Finder" discovers an abundance of giant viruses in the Antarctic dry valleys.

    PubMed

    Kerepesi, Csaba; Grolmusz, Vince

    2017-02-28

    Mimivirus was identified in 2003 from a biofilm of an industrial water-cooling tower in England. Later, numerous new giant viruses were found in oceans and freshwater habitats, some of them having 2,500 genes. We have demonstrated their likely presence in four soil samples taken from the Kutch Desert (Gujarat, India). Here we describe a bioinformatics work-flow, called the "Giant Virus Finder" that is capable of discovering the likely presence of the genomes of giant viruses in metagenomic shotgun-sequenced datasets. The new workflow is applied to numerous hot and cold desert soil samples as well as some tundra- and forest soils. We show that most of these samples contain giant viruses, especially in the Antarctic dry valleys. The results imply that giant viruses could be frequent not only in aqueous habitats, but in a wide spectrum of soils on our planet.

  11. YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?

    SciTech Connect

    Nesvorny, David

    2011-12-15

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside {approx}15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  12. Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

    USGS Publications Warehouse

    Wylie, G.D.; Casazza, M.L.; Gregory, C.J.; Halstead, B.J.

    2010-01-01

    The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

  13. The vocal repertoire of adult and neonate giant otters (Pteronura brasiliensis).

    PubMed

    Mumm, Christina A S; Knörnschild, Mirjam

    2014-01-01

    Animals use vocalizations to exchange information about external events, their own physical or motivational state, or about individuality and social affiliation. Infant babbling can enhance the development of the full adult vocal repertoire by providing ample opportunity for practice. Giant otters are very social and frequently vocalizing animals. They live in highly cohesive groups, generally including a reproductive pair and their offspring born in different years. This basic social structure may vary in the degree of relatedness of the group members. Individuals engage in shared group activities and different social roles and thus, the social organization of giant otters provides a basis for complex and long-term individual relationships. We recorded and analysed the vocalizations of adult and neonate giant otters from wild and captive groups. We classified the adult vocalizations according to their acoustic structure, and described their main behavioural context. Additionally, we present the first description of vocalizations uttered in babbling bouts of new born giant otters. We expected to find 1) a sophisticated vocal repertoire that would reflect the species' complex social organisation, 2) that giant otter vocalizations have a clear relationship between signal structure and function, and 3) that the vocal repertoire of new born giant otters would comprise age-specific vocalizations as well as precursors of the adult repertoire. We found a vocal repertoire with 22 distinct vocalization types produced by adults and 11 vocalization types within the babbling bouts of the neonates. A comparison within the otter subfamily suggests a relation between vocal and social complexity, with the giant otters being the socially and vocally most complex species.

  14. The Vocal Repertoire of Adult and Neonate Giant Otters (Pteronura brasiliensis)

    PubMed Central

    Mumm, Christina A. S.; Knörnschild, Mirjam

    2014-01-01

    Animals use vocalizations to exchange information about external events, their own physical or motivational state, or about individuality and social affiliation. Infant babbling can enhance the development of the full adult vocal repertoire by providing ample opportunity for practice. Giant otters are very social and frequently vocalizing animals. They live in highly cohesive groups, generally including a reproductive pair and their offspring born in different years. This basic social structure may vary in the degree of relatedness of the group members. Individuals engage in shared group activities and different social roles and thus, the social organization of giant otters provides a basis for complex and long-term individual relationships. We recorded and analysed the vocalizations of adult and neonate giant otters from wild and captive groups. We classified the adult vocalizations according to their acoustic structure, and described their main behavioural context. Additionally, we present the first description of vocalizations uttered in babbling bouts of new born giant otters. We expected to find 1) a sophisticated vocal repertoire that would reflect the species’ complex social organisation, 2) that giant otter vocalizations have a clear relationship between signal structure and function, and 3) that the vocal repertoire of new born giant otters would comprise age-specific vocalizations as well as precursors of the adult repertoire. We found a vocal repertoire with 22 distinct vocalization types produced by adults and 11 vocalization types within the babbling bouts of the neonates. A comparison within the otter subfamily suggests a relation between vocal and social complexity, with the giant otters being the socially and vocally most complex species. PMID:25391142

  15. Management considerations for giant congenital melanocytic nevi in adults.

    PubMed

    Green, Margaret C; Mitchum, Marsha D; Marquart, Jason D; Bingham, Jonathan L

    2014-04-01

    Giant congenital melanocytic nevi (GCMN) are a rare type of melanocytic nevus that covers a large body surface, often with satellite nevi scattered on the rest of the skin. There are several complications associated with GCMN, including malignant melanoma and neurocutaneous melanosis. The management of GCMN is very complex because of the cosmetic appearance and the associated psychological distress, the risk of severe complications, and the need for long-term follow-up. We report a case of a 43-year-old active-duty female with a GCMN reporting new and symptomatic satellite lesions with atypical features on dermoscopy.

  16. Radio emission from rapidly-rotating cool giant stars

    NASA Technical Reports Server (NTRS)

    Drake, Stephen A.; Walter, Frederick M.; Florkowski, David R.

    1990-01-01

    The results of a VLA program are reported to examine the radio continuum emission from 11 rapidly-rotating cool giant stars, all of which were originally believed to be single stars. Six of the 11 stars were detected as radio sources, including FK Com and HR 9024, for which there exist multifrequency observations. HD 199178, UZ Lib (now known to be a binary system), and HD 82558, for which there is only 6-cm data. The radio properties of these stars are compared with those of the active, rapidly rotating evolved stars found in the RS CVn binary systems.

  17. An MHD model for magnetar giant flares

    SciTech Connect

    Meng, Y.; Lin, J.; Zhang, Q. S.; Zhang, L.; Reeves, K. K.; Yuan, F. E-mail: jlin@ynao.ac.cn

    2014-04-10

    Giant flares on soft gamma-ray repeaters that are thought to take place on magnetars release enormous energy in a short time interval. Their power can be explained by catastrophic instabilities occurring in the magnetic field configuration and the subsequent magnetic reconnection. By analogy with the coronal mass ejection events on the Sun, we develop a theoretical model via an analytic approach for magnetar giant flares. In this model, the rotation and/or displacement of the crust causes the field to twist and deform, leading to flux rope formation in the magnetosphere and energy accumulation in the related configuration. When the energy and helicity stored in the configuration reach a threshold, the system loses its equilibrium, the flux rope is ejected outward in a catastrophic way, and magnetic reconnection helps the catastrophe develop to a plausible eruption. By taking SGR 1806–20 as an example, we calculate the free magnetic energy released in such an eruptive process and find that it is more than 10{sup 47} erg, which is enough to power a giant flare. The released free magnetic energy is converted into radiative energy, kinetic energy, and gravitational energy of the flux rope. We calculated the light curves of the eruptive processes for the giant flares of SGR 1806–20, SGR 0526–66, and SGR 1900+14, and compared them with the observational data. The calculated light curves are in good agreement with the observed light curves of giant flares.

  18. Giant cell tumor in adipose package Hoffa

    PubMed Central

    Etcheto, H. Rivarola; Escobar, G.; Blanchod, C. Collazo; Palanconi, M.; Zordan, J.; Salinas, E. Alvarez; Autorino₁, Carlos

    2017-01-01

    Tumors of adipose Hoffa package are very uncommon, with isolated cases reported in the literature. His presentation in pediatric patients knee is exceptional. The most frequently described tumors are benign including vellonodular synovitis. The extra-articular localized variant there of is known as giant cell tumor of the tendon sheath. It is characterized by locally aggressive nature, and has been described in reports of isolated cases. Objective: A case of giant cell tumor of the tendon sheath in adipose presentation package Hoffa in pediatric patients is presented in this paper. Methods: male patient eleven years with right knee pain after sports practice was evaluated. Physical examination, showed limited extension -30º, joint effusion, stable negative Lachman maneuver without peripheral knee laxity. MRI hyperintense on tumor is observed in T2 and hypointense on T1 homogeneous and defined edges content displayed prior to LCA related to adipose Hoffa package. Results: The tumor specimen was obtained and histopathology is defined as densely cellular tissue accumulation of xantomisados fibrocollagenous with histiocytes and multinucleated giant cells, compatible with giant cell tumor of tendon sheath. Conclusion: The presentation of giant cell tumors of the tendon sheath in Hoffa fat pad is exceptional. However, his suspicion allows adequate preoperative surgical planning, as a whole resection is the only procedure that has been shown to decrease the rate of recurrence of this disease.

  19. Electrodynamics on extrasolar giant planets

    SciTech Connect

    Koskinen, T. T.; Yelle, R. V.; Lavvas, P.; Cho, J. Y-K.

    2014-11-20

    Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of H and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially be

  20. Anaplastic giant cell thyroid carcinoma.

    PubMed

    Wallin, G; Lundell, G; Tennvall, J

    2004-01-01

    Anaplastic (giant cell) thyroid carcinoma (ATC), is one of the most aggressive malignancies in humans with a median survival time after diagnosis of 3-6 months. Death from ATC was earlier seen because of local growth and suffocation. ATC is uncommon, accounting for less than 5 % of all thyroid carcinomas. The diagnosis can be established by means of multiple fine needle aspiration biopsies, which are neither harmful nor troublesome for the patient. The cytological diagnosis of this high-grade malignant tumour is usually not difficult for a well trained cytologist. The intention to treat patients with ATC is cure, although only few of them survive. The majority of the patients are older than 60 years and treatment must be influenced by their high age. We have by using a combined modality regimen succeeded in achieving local control in most patients. Every effort should be made to control the primary tumour and thereby improve the quality of remaining life and it is important for patients, relatives and the personnel to know that cure is not impossible. Different treatment combinations have been used since 30 years including radiotherapy, cytostatic drugs and surgery, when feasible. In our latest combined regimen, 22 patients were treated with hyper fractionated radiotherapy 1.6Gy x 2 to a total target dose of 46 Gy given preoperatively, 20 mg doxorubicin was administered intravenously once weekly and surgery was carried out 2-3 weeks after the radiotherapy. 17 of these 22 patients were operated upon and none of these 17 patients got a local recurrence. In the future we are awaiting the development of new therapeutic approaches to this aggressive type of carcinoma. Inhibitors of angiogenesis might be useful. Combretastatin has displayed cytotoxicity against ATC cell lines and has had a positive effect on ATC in a patient. Sodium iodide symporter (NIS) genetherapy is also being currently considered for dedifferentiated thyroid carcinomas with the ultimate aim of

  1. A GIANT SAMPLE OF GIANT PULSES FROM THE CRAB PULSAR

    SciTech Connect

    Mickaliger, M. B.; McLaughlin, M. A.; Lorimer, D. R.; Palliyaguru, N.; Langston, G. I.; Bilous, A. V.; Kondratiev, V. I.; Lyutikov, M.; Ransom, S. M.

    2012-11-20

    We observed the Crab pulsar with the 43 m telescope in Green Bank, WV over a timespan of 15 months. In total we obtained 100 hr of data at 1.2 GHz and seven hours at 330 MHz, resulting in a sample of about 95,000 giant pulses (GPs). This is the largest sample, to date, of GPs from the Crab pulsar taken with the same telescope and backend and analyzed as one data set. We calculated power-law fits to amplitude distributions for main pulse (MP) and interpulse (IP) GPs, resulting in indices in the range of 2.1-3.1 for MP GPs at 1.2 GHz and in the range of 2.5-3.0 and 2.4-3.1 for MP and IP GPs at 330 MHz. We also correlated the GPs at 1.2 GHz with GPs from the Robert C. Byrd Green Bank Telescope (GBT), which were obtained simultaneously at a higher frequency (8.9 GHz) over a span of 26 hr. In total, 7933 GPs from the 43 m telescope at 1.2 GHz and 39,900 GPs from the GBT were recorded during these contemporaneous observations. At 1.2 GHz, 236 (3%) MP GPs and 23 (5%) IP GPs were detected at 8.9 GHz, both with zero chance probability. Another 15 (4%) low-frequency IP GPs were detected within one spin period of high-frequency IP GPs, with a chance probability of 9%. This indicates that the emission processes at high and low radio frequencies are related, despite significant pulse profile shape differences. The 43 m GPs were also correlated with Fermi {gamma}-ray photons to see if increased pair production in the magnetosphere is the mechanism responsible for GP emission. A total of 92,022 GPs and 393 {gamma}-ray photons were used in this correlation analysis. No significant correlations were found between GPs and {gamma}-ray photons. This indicates that increased pair production in the magnetosphere is likely not the dominant cause of GPs. Possible methods of GP production may be increased coherence of synchrotron emission or changes in beaming direction.

  2. Disappearance of giant cells and presence of newly formed bone in the pulmonary metastasis of a sacral giant-cell tumor following denosumab treatment: A case report.

    PubMed

    Yamagishi, Tetsuro; Kawashima, Hiroyuki; Ogose, Akira; Sasaki, Taro; Hotta, Tetsuo; Inagawa, Shoichi; Umezu, Hajime; Endo, Naoto

    2016-01-01

    A giant-cell tumor of the bone (GCTB) is a benign but locally aggressive bone tumor. Recently, the receptor activator of nuclear factor κB (RANK) ligand inhibitor, denosumab, has demonstrated activity against giant-cell tumors. The current study reports a case of a sacral GCTB with lung metastasis. A 19-year-old male patient presented with right buttock pain and right lower leg pain, and a sacral GCTB was diagnosed based on the histological analysis of a biopsy specimen. The patient was successfully treated with neoadjuvant denosumab therapy, which allowed curettage. In addition, the pulmonary nodule reduced in size following denosumab administration, and surgical resection was performed. Since the operation, the patient has been managed with the continued use of denosumab with no sign of recurrence. Microscopic findings from the surgical specimen following denosumab treatment revealed that the giant cells had disappeared and woven bone had formed. The specimen from the pulmonary nodule exhibited similar findings to the surgical specimen. It was reported that denosumab treatment was able to reduce the number of giant cells and RANK-positive stromal cells, and cause the formation of new bone in the primary lesion. The present study reports the first case to demonstrate the efficiency of denosumab in treating pulmonary metastasis of GCTB.

  3. a Survey of Giant Resonance Excitations with 200 Mev Protons

    NASA Astrophysics Data System (ADS)

    Tinsley, James Royce

    The giant resonance region in ('60)Ni, ('90)Zr, ('120)Sn, and ('208)Pb has been studied using inelastic scattering of 200 MeV protons. Angular distributions were obtained for the giant quadrupole resonance, giant octupole resonance, and for the combined giant dipole and giant monopole resonance between 4 and 20 degrees. The 2(H/2PI)(omega) component of the giant hexadecapole resonance has been directly observed for the first time in ('208)Pb. In the other nuclei, upper limits on the amount of hexadecapole strength contained within the giant quadrupole resonance have been obtained. Peaks are observed in ('60)Ni and ('90)Zr that are consistent with recently reported M1 states. Discrepancies between sum rules extracted from this data and from previous work are discussed. Possible explanations include DWBA breakdown or difficulties in estimating the magnitude of the continuum. Systematics obtained for the giant resonances are compared to earlier work.

  4. What Are Polymyalgia Rheumatica and Giant Cell Arteritis?

    MedlinePlus

    ... permanently damaged. There is also a risk of blindness or stroke. Early symptoms of giant cell arteritis ... giant cell arteritis are more likely to develop blindness. The likelihood of getting these conditions peaks between ...

  5. Giant faraday rotation in conjugated, rod-like molecules

    NASA Astrophysics Data System (ADS)

    Vleugels, Rick; Brullot, Ward; Verbiest, Thierry

    2016-09-01

    Faraday rotation is a magneto-optic phenomenon in which the polarization plane of light is rotated due to magnetically induced circular birefringence. It can be used in a variety of applications such as optical isolators, magnetic field sensors and current sensors. So far, most of the applications use inorganic, paramagnetic materials, which have Verdet constants up to millions of degrees per tesla per meter in the visible spectrum range. They are performant at telecommunication wavelengths, though with smaller Verdet constants, so thicker materials are used. Disadvantages of these materials are their magnetic saturation at low magnetic fields and their strong temperature dependency. Organic, diamagnetic materials on the contrary, saturate at much larger magnetic fields and are less temperature dependent. Furthermore, they also have the advantage of their flexibility and processability. Up to now, magneto-optical research on organic materials has mostly characterized materials with low magneto-optical activity in regions without absorption, but there are some exceptions. Some pi-conjugated polymers have been shown to have very large magneto-optic responses. Furthermore, a mesogenic, organic molecule has been reported with a very high Verdet constant. Conclusive explanations for these large Verdet constants are still lacking, but different possible hypotheses were proposed. In our ongoing search for organic materials with exceptional magneto-optical properties, we examined conjugated, rod-like molecules. Structural, these molecules show close resemblances with the earlier reported mesogenic, organic molecule. We measured giant Verdet constants for thin films of these molecules, reaching values almost as giant as the previous reported mesogenic molecule. These findings shed first preliminary light on a structure-activity relationship for giant Faraday rotation in diamagnetic organic materials.

  6. Multinucleated Giant Cancer Cells Produced in Response to Ionizing Radiation Retain Viability and Replicate Their Genome

    PubMed Central

    Mirzayans, Razmik; Andrais, Bonnie; Scott, April; Wang, Ying W.; Kumar, Piyush; Murray, David

    2017-01-01

    Loss of wild-type p53 function is widely accepted to be permissive for the development of multinucleated giant cells. However, whether therapy-induced multinucleation is associated with cancer cell death or survival remains controversial. Herein, we demonstrate that exposure of p53-deficient or p21WAF1 (p21)-deficient solid tumor-derived cell lines to ionizing radiation (between 2 and 8 Gy) results in the development of multinucleated giant cells that remain adherent to the culture dish for long times post-irradiation. Somewhat surprisingly, single-cell observations revealed that virtually all multinucleated giant cells that remain adherent for the duration of the experiments (up to three weeks post-irradiation) retain viability and metabolize 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), and the majority (>60%) exhibit DNA synthesis. We further report that treatment of multinucleated giant cells with pharmacological activators of apoptosis (e.g., sodium salicylate) triggers their demise. Our observations reinforce the notion that radiation-induced multinucleation may reflect a survival mechanism for p53/p21-deficient cancer cells. With respect to evaluating radiosensitivity, our observations underscore the importance of single-cell experimental approaches (e.g., single-cell MTT) as the creation of viable multinucleated giant cells complicates the interpretation of the experimental data obtained by commonly-used multi-well plate colorimetric assays. PMID:28208747

  7. BD+15 2940 AND HD 233604: TWO GIANTS WITH PLANETS CLOSE TO THE ENGULFMENT ZONE

    SciTech Connect

    Nowak, G.; Niedzielski, A.; Adamow, M.; Maciejewski, G.; Wolszczan, A. E-mail: andrzej.niedzielski@astri.umk.pl E-mail: gracjan.maciejewski@astri.umk.pl

    2013-06-10

    We report the discovery of planetary-mass companions to two red giants by the ongoing Penn State-Torun Planet Search (PTPS) conducted with the 9.2 m Hobby-Eberly Telescope. The 1.1 M{sub Sun} K0-giant, BD+15 2940, has a 1.1 M{sub J} minimum mass companion orbiting the star at a 137.5 day period in a 0.54 AU orbit what makes it the closest-in planet around a giant and possible subject of engulfment as the consequence of stellar evolution. HD 233604, a 1.5 M{sub Sun} K5-giant, is orbited by a 6.6 M{sub J} minimum mass planet which has a period of 192 days and a semi-major axis of only 0.75 AU making it one of the least distant planets to a giant star. The chemical composition analysis of HD 233604 reveals a relatively high {sup 7}Li abundance which may be a sign of its early evolutionary stage or recent engulfment of another planet in the system. We also present independent detections of planetary-mass companions to HD 209458 and HD 88133, and stellar activity-induced radial velocity variations in HD 166435, as part of the discussion of the observing and data analysis methods used in the PTPS project.

  8. The morphology and fine structure of the giant interneurons of the wood cricket Nemobius sylvestris.

    PubMed

    Insausti, T C; Lazzari, C R; Casas, J

    2011-02-01

    The structural and ultrastructural characteristics of giant interneurons in the terminal abdominal ganglion of the cricket Nemobius sylvestris were investigated by means of cobalt and fluorescent dye backfilling and transmission electron microscopy. The projections of the 8 eight pairs of the biggest ascending interneurons (giant interneurons) are described in detail. The somata of all interneurons analyzed are located contralateral to their axons, which project to the posterior region of the terminal ganglion and arborise in the cercal glomerulus. Neuron 7-1a is an exception, because its arborisation is restricted to the anterior region of the ganglion. The fine structure of giant interneurons shows typical features of highly active cells. We observed striking indentations in the perineural layer, enabling the somata of the giant interneurons to be very close to the haemolymph. The cercal glomerulus exhibits a high diversity of synaptic contacts (i.e. axo-dendritic, axo-axonic, dendro-axonic, and dendro-dendritic), as well as areas of tight junctions. Electrical synapses seem to be present, as well as mixed synapses. The anatomical organization of the giant interneurons is finally discussed in terms of functional implications and on a comparative basis.

  9. Heavy elements and mixing in red giants

    NASA Astrophysics Data System (ADS)

    Smith, Verne V.

    A brief overview of the s-process in red giants is presented, followed by discussions of three specific topics involving heavy-element s-process nucleosynthesis and mixing in red giants: (1) a comparison of neutron densities derived from observations and from the most recent stellar models, (2) how observations of technetium in S stars have led to a natural division of these stars into two separate groups, one of which is the result of single-star stellar evolution while the other is the result of mass transfer in a binary system, (3) a brief discussion of the recent speculative suggestion that gamma-ray induced photofission of heavy elements (Th and U) might be a source of the Tc observed in certain types of red giants.

  10. Trace Molecules in Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Huestis, D. L.; Smith, G. P.

    2010-12-01

    Chemical kinetics matters in the upper atmospheres of giant planets in our solar system and in extrasolar systems. The composition of a volume of gas depends not only on where it is, but also on how it got there. The giant planets in our own solar system still have much to teach us about what we will be observing on extrasolar giant planets and how to interpret what we observe. Some molecules, such as CO, C2H2, C2H6, PH3, and NH3, which we call tracer molecules, provide remotely observable signatures of vertical transport. PH3 and NH3 especially have complicated thermochemistry and chemical kinetics that, until recently, have been poorly understood. Based on analysis of recent literature, we have identified new chemical mechanisms for interconverting NH3 and N2 and for interconverting PH3 and NH4-H2PO4.

  11. Compositional constraints on giant planet formation

    NASA Astrophysics Data System (ADS)

    Owen, Tobias; Encrenaz, Therese

    2006-10-01

    Using Ockham's razor as a guide, we have tried to find the simplest model for the formation of giant planets that can explain current observations of atmospheric composition. While this "top-down" approach is far from sufficient to define such models, it establishes a set of boundary conditions whose satisfaction is necessary. Using Jupiter as the prototype, we find that a simple model for giant planet formation that begins with a solar nebula of uniform composition and relies on accretion of low temperature icy planetesimals plus collapse of surrounding solar nebula gas supplies that satisfaction. We compare the resulting predictions of elemental abundances and isotope ratios in the atmospheres of the other giants with those from contrasting models and suggest some key measurements to make further progress.

  12. ɛ Ophiuchi: Revisiting a Red Giant

    NASA Astrophysics Data System (ADS)

    Kallinger, T.; Matthews, J. M.; Guenther, D. B.; Gruberbauer, M.; Kuschnig, R.; Weiss, W. W.; MOST Team

    2012-09-01

    In only a decade, seismology of red-giant stars has grown from infancy to adulthood in the study of stellar structure and evolution. The stimulants for this accelerated growth have been space observations, first provided by the WIRE star-tracker and MOST, and continuing with CoRoT and Kepler, having detected oscillations in thousands of cool giants. However, almost all of the stars in this impressive sample are faint, with little known about their basic properties. Even reliable spectral classifications are lacking for many of them. MOST is the only space-based photometer capable of continuous observations of bright red giants for which we have independent constraints (e.g., spectroscopy) essential to extract the internal structure from the stars' p-modes.

  13. On the shape of giant soap bubbles.

    PubMed

    Cohen, Caroline; Darbois Texier, Baptiste; Reyssat, Etienne; Snoeijer, Jacco H; Quéré, David; Clanet, Christophe

    2017-03-07

    We study the effect of gravity on giant soap bubbles and show that it becomes dominant above the critical size [Formula: see text], where [Formula: see text] is the mean thickness of the soap film and [Formula: see text] is the capillary length ([Formula: see text] stands for vapor-liquid surface tension, and [Formula: see text] stands for the liquid density). We first show experimentally that large soap bubbles do not retain a spherical shape but flatten when increasing their size. A theoretical model is then developed to account for this effect, predicting the shape based on mechanical equilibrium. In stark contrast to liquid drops, we show that there is no mechanical limit of the height of giant bubble shapes. In practice, the physicochemical constraints imposed by surfactant molecules limit the access to this large asymptotic domain. However, by an exact analogy, it is shown how the giant bubble shapes can be realized by large inflatable structures.

  14. Asymptomatic post-rheumatic giant left atrium

    PubMed Central

    Özkartal, Tardu; Tanner, Felix C; Niemann, Markus

    2016-01-01

    A 78-year-old asymptomatic woman was referred to our clinic for a second opinion regarding indication for mitral valve surgery. An echocardiogram showed a moderate mitral stenosis with a concomitant severe regurgitation. The most striking feature, however, was a giant left atrium with a parasternal anteroposterior diameter of 79 mm and a left atrial volume index of 364 mL/m². There are various echocardiographic definitions of a giant left atrium, which are mainly based on measurements of the anteroposterior diameter of the left atrium using M-mode in the parasternal long axis view. Since the commonly accepted method for echocardiographic evaluation of left atrial size is left atrial volume index, we propose a cut-off value of 140 mL/m2 for the definition of a “giant left atrium”. PMID:27354895

  15. LITHIUM-RICH GIANTS IN GLOBULAR CLUSTERS

    SciTech Connect

    Kirby, Evan N.; Cohen, Judith G.; Guhathakurta, Puragra; Hong, Jerry; Guo, Michelle; Guo, Rachel; Cunha, Katia

    2016-03-10

    Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron–Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistent with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval.

  16. Lithium-rich Giants in Globular Clusters

    NASA Astrophysics Data System (ADS)

    Kirby, Evan N.; Guhathakurta, Puragra; Zhang, Andrew J.; Hong, Jerry; Guo, Michelle; Guo, Rachel; Cohen, Judith G.; Cunha, Katia

    2016-03-01

    Although red giants deplete lithium on their surfaces, some giants are Li-rich. Intermediate-mass asymptotic giant branch (AGB) stars can generate Li through the Cameron-Fowler conveyor, but the existence of Li-rich, low-mass red giant branch (RGB) stars is puzzling. Globular clusters are the best sites to examine this phenomenon because it is straightforward to determine membership in the cluster and to identify the evolutionary state of each star. In 72 hours of Keck/DEIMOS exposures in 25 clusters, we found four Li-rich RGB and two Li-rich AGB stars. There were 1696 RGB and 125 AGB stars with measurements or upper limits consistent with normal abundances of Li. Hence, the frequency of Li-richness in globular clusters is (0.2 ± 0.1)% for the RGB, (1.6 ± 1.1)% for the AGB, and (0.3 ± 0.1)% for all giants. Because the Li-rich RGB stars are on the lower RGB, Li self-generation mechanisms proposed to occur at the luminosity function bump or He core flash cannot explain these four lower RGB stars. We propose the following origin for Li enrichment: (1) All luminous giants experience a brief phase of Li enrichment at the He core flash. (2) All post-RGB stars with binary companions on the lower RGB will engage in mass transfer. This scenario predicts that 0.1% of lower RGB stars will appear Li-rich due to mass transfer from a recently Li-enhanced companion. This frequency is at the lower end of our confidence interval. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  17. [Giant cell arteritis--case report].

    PubMed

    Napora, Katarzyna J; Obuchowska, Iwona; Mariak, Zofia

    2008-01-01

    Giant cell arteritis is a systemic disease of unknown origin. Vasculitis involves large and medium-sized vessels. Frequent clinical manifestations include characteristic headache in the temporal area, jaw or tongue claudication, apathy, fatigue, weight loss. The incidence of ocular involvement is reported in up to 70% patients. The most common and serious ophthalmic presentation is arteritic anterior ischemic optic neuropathy, which can lead to irreversible visual loss. Only early and aggressive steroid therapy may prevent this dangerous complication. The authors presented a case of a 68-years-old woman with giant cell arteritis. The main visual manifestation of this disease was anterior ischemic optic neuropathy.

  18. A giant Pseudomonas phage from Poland.

    PubMed

    Drulis-Kawa, Zuzanna; Olszak, Tomasz; Danis, Katarzyna; Majkowska-Skrobek, Grazyna; Ackermann, Hans-W

    2014-03-01

    A novel giant phage of the family Myoviridae is described. Pseudomonas phage PA5oct was isolated from a sewage sample from an irrigated field near Wroclaw, Poland. The virion morphology indicates that PA5oct differs from known giant phages. The phage has a head of about 131 nm in diameter and a tail of 136 × 19 nm. Phage PA5oct contains a genome of approximately 375 kbp and differs in size from any tailed phages known. PA5oct was further characterized by determination of its latent period and burst size and its sensitivity to heating, chloroform, and pH.

  19. Isoscalar giant resonances in {sup 48}Ca

    SciTech Connect

    Lui, Y.-W.; Youngblood, D. H.; Shlomo, S.; Chen, X.; Tokimoto, Y.; Krishichayan,; Anders, M.; Button, J.

    2011-04-15

    The giant resonance region from 9.5 MeV < E{sub x} < 40 MeV in {sup 48}Ca has been studied with inelastic scattering of 240-MeV {alpha} particles at small angles, including 0 deg. 95{sub -15}{sup +11}% of E0 energy-weighted sum rule (EWSR), 83{sub -16}{sup +10}% of E2 EWSR, and 137 {+-} 20% of E1 EWSR were located below E{sub x}=40 MeV. A comparison of the experimental data with calculated results for the isoscalar giant monopole resonance, obtained within the mean-field-based random-phase approximation, is also given.

  20. Giant-cell lesions of the facial bones

    SciTech Connect

    Som, P.M.; Lawson, W.; Cohen, B.A.

    1983-04-01

    Giant-cell lesions of the paranasal sinuses, including the giant-cell reparative granuloma, the brown tumor of hyperparathyroidism, the true giant-cell tumor, cherubism, and the aneurysmal bone cyst, are uncommon entities. Plain radiographic and computed-tomographic studies of these lesions are described and the differential diagnosis is discussed.

  1. Denosumab-treated Giant Cell Tumor of Bone Exhibits Morphologic Overlap With Malignant Giant Cell Tumor of Bone.

    PubMed

    Wojcik, John; Rosenberg, Andrew E; Bredella, Miriam A; Choy, Edwin; Hornicek, Francis J; Nielsen, G Petur; Deshpande, Vikram

    2016-01-01

    Giant cell tumor (GCT) of bone is a locally aggressive benign neoplasm characterized by an abundance of osteoclastic giant cells that are induced by the neoplastic mononuclear cells; the latter express high levels of receptor activator of nuclear factor κ-B ligand (RANKL). Denosumab, a RANKL inhibitor, which is clinically used to treat GCT, leads to a marked alteration in the histologic appearance of the tumor with giant cell depletion and new bone deposition, leading to substantial histologic overlap with other primary tumors of bone. Most significantly, denosumab-treated GCT (tGCT) with abundant bone deposition may mimic de novo osteosarcoma, or GCT that has undergone malignant transformation. To histologically characterize tGCT, we identified 9 cases of GCT biopsied or resected after denosumab treatment. tGCT cases included 16 specimens from 9 patients including 6 female and 3 male individuals aged 16 to 47 (median 32) years. Duration of treatment varied from 2 to 55 months. We compared these tumors with malignant neoplasms arising in GCTs (n=9). The histology of tGCT was variable but appeared to relate to the length of therapy. All tGCTs showed marked giant cell depletion. Early lesions were highly cellular, and the combination of cellularity, atypia, and haphazard bone deposition caused the lesion to resemble high-grade osteosarcoma. Unlike de novo high-grade osteosarcoma or malignancies arising in GCT, however, tGCT showed less severe atypia, reduced mitotic activity, and lack of infiltrative growth pattern. Tumor in patients on prolonged therapy showed decreased cellularity and abundant new bone, deposited as broad, rounded cords or long, curvilinear arrays. The latter morphology was reminiscent of low-grade central osteosarcoma, but, unlike low-grade central osteosarcoma, tGCT was negative for MDM2 and again lacked an infiltrative growth pattern. Overall, tGCT may have a wide range of morphologic appearances. Because the treated tumors bear little

  2. Multisatellite observations of a giant pulsation event

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazue; Glassmeier, Karl-Heinz; Angelopoulos, Vassilis; Bonnell, John; Nishimura, Yukitoshi; Singer, Howard J.; Russell, Christopher T.

    2011-11-01

    Giant pulsations (Pgs; frequency ˜10 mHz) were detected with ground magnetometers on the North American continent on 19 October 2008, when the GOES-10, -11, -12, and -13 geostationary satellites and the THEMIS-A probe were magnetically connected to the region of the ground pulsation activity. This unique configuration allowed us to determine the properties of magnetospheric ultra-low-frequency (ULF) waves that caused the Pgs on the ground. All spacecraft detected monochromatic ULF waves at ˜10 mHz, and the coherence between the Pg at the Gillam ground station and the ULF wave at THEMIS-A was high when the magnetic field foot point of the spacecraft came close to the ground station. The ULF waves observed by the five spacecraft had perturbations in the radial and compressional components of the magnetic field and in the azimuthal component of the electric field, which are attributed to poloidal mode standing Alfvén waves. The poloidal waves were accompanied by multiharmonic toroidal waves, and from the frequency relationship among these, it is concluded that the ˜10 mHz oscillations correspond to the fundamental (odd, or symmetric) mode. The standing wave mode also explains the amplitude variation with latitude and the phase delay between the magnetic and electric fields. Numerical models of poloidal waves incorporating finite height integrated ionospheric conductivity indicate that the fundamental mode interpretation is valid even when the damping of the standing waves is strong. Our observations are the most comprehensive to date in terms of spacecraft data, and we believe that theoretical work on the Pg generation mechanism should focus on mechanisms specific to odd mode standing waves, such as drift resonance of ring current ions.

  3. Multisatellite Observations of a Giant Pulsation Event

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Glassmeier, K.; Angelopoulos, V.; Bonnell, J. W.; Nishimura, T.; Singer, H. J.; Russell, C. T.

    2011-12-01

    Giant pulsations (Pgs; frequency ~10 mHz) were detected with ground magnetometers in the North American continent on October 2008, when the GOES-10, -11, -12, and -13 geostationary satellites and the THEMIS-A probe were magnetically connected to the region of the ground pulsation activity. This unique observational configuration allowed us to determine the properties of magnetospheric ultra-low-frequency (ULF) waves that caused the Pgs on the ground. All spacecraft detected monochromatic ULF waves at ~10 mHz, and the coherence between the Pg at the Gillam ground station and the ULF wave at THEMIS-A was high when the magnetic field foot point of the spacecraft came close to the ground station, indicating a causal relationship between the two oscillation phenomena. The ULF waves observed by the five spacecraft had perturbations in the radial and compressional components of the magnetic field and in the azimuthal component of the electric field, which are attributed to poloidal mode standing Alfvén waves. The poloidal waves were accompanied by multiharmonic toroidal waves, and from the frequency relationship among these, it is concluded that the ~10 mHz oscillations correspond to the fundamental (odd, or symmetric) mode. The standing wave mode also explains the amplitude variation with latitude and the phase delay between the magnetic and electric fields. Numerical models of poloidal waves incorporating finite ionospheric conductivity indicate that the fundamental mode interpretation is valid even when the damping of the standing waves is strong. Our observations are the most comprehensive to date in terms of spacecraft data, and we believe that theoretical work on the Pg generation mechanism should focus on mechanisms specific to odd mode standing waves, such as drift resonance of ring current ions.

  4. MAPPING DIRECTLY IMAGED GIANT EXOPLANETS

    SciTech Connect

    Kostov, Veselin; Apai, Daniel

    2013-01-01

    With the increasing number of directly imaged giant exoplanets, the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational modulations these planets may show. We propose that the time-resolved observations of such periodic photometric and spectroscopic variations of extrasolar planets due to their rotation can be used as a powerful tool to probe the heterogeneity of their optical surfaces. In this paper, we develop simulations to explore the capabilities of current and next-generation ground- and space-based instruments for this technique. We address and discuss the following questions: (1) what planet properties can be deduced from the light curve and/or spectra, and in particular can we determine rotation periods, spot coverage, spot colors, and spot spectra?; (2) what is the optimal configuration of instrument/wavelength/temporal sampling required for these measurements?; and (3) can principal component analysis be used to invert the light curve and deduce the surface map of the planet? Our simulations describe the expected spectral differences between homogeneous (clear or cloudy) and patchy atmospheres, outline the significance of the dominant absorption features of H{sub 2}O, CH{sub 4}, and CO, and provide a method to distinguish these two types of atmospheres. Assuming surfaces with and without clouds for most currently imaged planets the current models predict the largest variations in the J band. Simulated photometry from current and future instruments is used to estimate the level of detectable photometric variations. We conclude that future instruments will be able to recover not only the rotation periods

  5. THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED

    SciTech Connect

    Miller, Neil; Fortney, Jonathan J.

    2011-08-01

    We investigate a population of transiting planets that receive relatively modest stellar insolation, indicating equilibrium temperatures <1000 K, and for which the heating mechanism that inflates hot Jupiters does not appear to be significantly active. We use structural evolution models to infer the amount of heavy elements within each of these planets. There is a correlation between the stellar metallicity and the mass of heavy elements in its transiting planet(s). It appears that all giant planets possess a minimum of {approx}10-15 Earth masses of heavy elements, with planets around metal-rich stars having larger heavy-element masses. There is also an inverse relationship between the mass of the planet and the metal enrichment (Z{sub pl}/Z{sub star}), which appears to have little dependency on the metallicity of the star. Saturn- and Jupiter-like enrichments above solar composition are a hallmark of all the gas giants in the sample, even planets of several Jupiter masses. These relationships provide an important constraint on planet formation and suggest large amounts of heavy elements within planetary H/He envelopes. We suggest that the observed correlation can soon also be applied to inflated planets, such that the interior heavy-element abundance of these planets could be estimated, yielding better constraints on their interior energy sources. We point to future directions for planetary population synthesis models and suggest future correlations. This appears to be the first evidence that extrasolar giant planets, as a class, are enhanced in heavy elements.

  6. THE REDSHIFT DISTRIBUTION OF GIANT ARCS IN THE SLOAN GIANT ARCS SURVEY

    SciTech Connect

    Bayliss, Matthew B.; Gladders, Michael D.; Koester, Benjamin P.; Oguri, Masamune; Hennawi, Joseph F.; Sharon, Keren; Dahle, Haakon

    2011-01-20

    We measure the redshift distribution of a sample of 28 giant arcs discovered as a part of the Sloan Giant Arcs Survey. Gemini/GMOS-North spectroscopy provides precise redshifts for 24 arcs, and 'redshift desert' constrains for the remaining 4 arcs. This is a direct measurement of the redshift distribution of a uniformly selected sample of bright giant arcs, which is an observable that can be used to inform efforts to predict giant arc statistics. Our primary giant arc sample has a median redshift z = 1.821 and nearly two-thirds of the arcs, 64%, are sources at z {approx}> 1.4, indicating that the population of background sources that are strongly lensed into bright giant arcs resides primarily at high redshift. We also analyze the distribution of redshifts for 19 secondary strongly lensed background sources that are not visually apparent in Sloan Digital Sky Survey imaging, but were identified in deeper follow-up imaging of the lensing cluster fields. Our redshift sample for the secondary sources is not spectroscopically complete, but combining it with our primary giant arc sample suggests that a large fraction of all background galaxies that are strongly lensed by foreground clusters reside at z {approx}> 1.4. Kolmogorov-Smirnov tests indicate that our well-selected, spectroscopically complete primary giant arc redshift sample can be reproduced with a model distribution that is constructed from a combination of results from studies of strong-lensing clusters in numerical simulations and observational constraints on the galaxy luminosity function.

  7. Hydrogel-assisted functional reconstitution of human P-glycoprotein (ABCB1) in giant liposomes

    PubMed Central

    Horger, Kim S.; Liu, Haiyan; Rao, Divya K.; Shukla, Suneet; Sept, David; Ambudkar, Suresh V.; Mayer, Michael

    2015-01-01

    This paper describes the formation of giant proteoliposomes containing P-glycoprotein (P-gp) from a solution of small proteoliposomes that had been deposited and partially dried on a film of agarose. This preparation method generated a significant fraction of giant proteoliposomes that were free of internalized vesicles, making it possible to determine the accessible liposome volume. Measuring the intensity of the fluorescent substrate rhodamine 123 (Rho123) inside and outside these giant proteoliposomes determined the concentration of transported substrates of P-gp. Fitting a kinetic model to the fluorescence data revealed the rate of passive diffusion as well as active transport by reconstituted P-gp in the membrane. This approach determined estimates for the membrane permeability coefficient (Ps) of passive diffusion and rate constants of active transport (kT) by P-gp as a result of different experimental conditions. The Ps value for Rho123 was larger in membranes containing P-gp under all assay conditions than in membranes without P-gp indicating increased leakiness in the presence of reconstituted transmembrane proteins. For P-gp liposomes, the kT value was significantly higher in the presence of ATP than in its absence or in the presence of ATP and the competitive inhibitor verapamil. This difference in kT values verified that P-gp was functionally active after reconstitution and quantified the rate of active transport. Lastly, patch clamp experiments on giant proteoliposomes showed ion channel activity consistent with a chloride ion channel protein that co-purified with P-gp. Together, these results demonstrate several advantages of using giant rather than small proteoliposomes to characterize transport properties of transport proteins and ion channels. PMID:25450342

  8. Sucrose-mediated giant cell formation in the genus Neisseria.

    PubMed

    Johnson, K G; McDonald, I J

    1976-03-01

    Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.

  9. Giant-cell granuloma of the sinuses

    SciTech Connect

    Rhea, J.T.; Weber, A.L.

    1983-04-01

    Three cases are presented which illustrate giant-cell granulomas in the maxillary, ethmoid, and sphenoid sinuses. The radiographic features are nonspecific, and the lesion can mimic carcinoma. Ossification can be demonstrated, especially with computed tomography, and may indicate a benign lesion.

  10. Vocal repertoire of the social giant otter.

    PubMed

    Leuchtenberger, Caroline; Sousa-Lima, Renata; Duplaix, Nicole; Magnusson, William E; Mourão, Guilherme

    2014-11-01

    According to the "social intelligence hypothesis," species with complex social interactions have more sophisticated communication systems. Giant otters (Pteronura brasiliensis) live in groups with complex social interactions. It is likely that the vocal communication of giant otters is more sophisticated than previous studies suggest. The objectives of the current study were to describe the airborne vocal repertoire of giant otters in the Pantanal area of Brazil, to analyze call types within different behavioral contexts, and to correlate vocal complexity with level of sociability of mustelids to verify whether or not the result supports the social intelligence hypothesis. The behavior of nine giant otters groups was observed. Vocalizations recorded were acoustically and statistically analyzed to describe the species' repertoire. The repertoire was comprised by 15 sound types emitted in different behavioral contexts. The main behavioral contexts of each sound type were significantly associated with the acoustic variable ordination of different sound types. A strong correlation between vocal complexity and sociability was found for different species, suggesting that the communication systems observed in the family mustelidae support the social intelligence hypothesis.

  11. Giant Viruses of Amoebas: An Update.

    PubMed

    Aherfi, Sarah; Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2016-01-01

    During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea, and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreover, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages.

  12. Giant infantile gliosarcoma: magnetic resonance imaging findings.

    PubMed

    Sanal, Hatice Tuba; Bulakbasi, Nail; Kocaoglu, Murat; Onguru, Onder; Chen, Lina

    2008-08-01

    Gliosarcoma is an uncommon variant of glioblastoma multiforme, which is composed of gliomatous and sarcomatous elements. The tumor is rarely encountered in childhood. This case report presents the magnetic resonance imaging characteristics of a giant gliosarcoma in a 3-year-old girl. Size and location of the tumor are described.

  13. Giant leucaena (koa haole) energy tree farm

    SciTech Connect

    Brewbaker, J.L.

    1980-09-01

    Giant leucaena is a tall arboreal form of the common koa haole of the tropics that is known for its wide adaptability, hardiness, and rapid growth. Wood yields of the giant leucaena equal or exceed those of other tropical trees and can be the equivalent annually of 30 barrels of oil per acre. In addition, the tree is a legume that produces a marketable co-product, a nutritious, high-nitrogen leaf meal. A thorough assessment is provided of the known yield capability of giant leucaena, its soil and fertilizer needs, its impact on the environment, its water and irrigation needs, its handling from nursery through establishment, its wood properties and combustion characteristics, and methods of harvesting suitable for the comparatively small trees to be grown. Analyses are also given of capital equipment and operating expenses, labor needs, effects of tax incentives, and economic considerations of application to various scenarios and market conditions in Hawaii. This study suggests that giant leucaena could be grown profitably in Molokai as a source of fuel wood and co-product animal feed.

  14. Giant light enhancement in atomic clusters

    SciTech Connect

    Gadomsky, O. N. Gadomskaya, I. V.; Altunin, K. K.

    2009-07-15

    We show that the polarizing effect of the atoms in an atomic cluster can lead to full compensation of the radiative damping of excited atomic states, a change in the sign of the dispersion of the atomic polarizability, and giant light enhancement by the atomic cluster.

  15. Asteroseismic Diagram for Subgiants and Red Giants

    NASA Astrophysics Data System (ADS)

    Gai, Ning; Tang, Yanke; Yu, Peng; Dou, Xianghua

    2017-02-01

    Asteroseismology is a powerful tool for constraining stellar parameters. NASA’s Kepler mission is providing individual eigenfrequencies for a huge number of stars, including thousands of red giants. Besides the frequencies of acoustic modes, an important breakthrough of the Kepler mission is the detection of nonradial gravity-dominated mixed-mode oscillations in red giants. Unlike pure acoustic modes, mixed modes probe deeply into the interior of stars, allowing the stellar core properties and evolution of stars to be derived. In this work, using the gravity-mode period spacing and the large frequency separation, we construct the ΔΠ1–Δν asteroseismic diagram from models of subgiants and red giants with various masses and metallicities. The relationship ΔΠ1–Δν is able to constrain the ages and masses of the subgiants. Meanwhile, for red giants with masses above 1.5 M ⊙, the ΔΠ1–Δν asteroseismic diagram can also work well to constrain the stellar age and mass. Additionally, we calculate the relative “isochrones” τ, which indicate similar evolution states especially for similar mass stars, on the ΔΠ1–Δν diagram.

  16. Giant Cavernous Haemangioma of the Anterior Mediastinum

    PubMed Central

    Kaya, Seyda Ors; Samancılar, Ozgur; Usluer, Ozan; Acar, Tuba; Yener, Ali Galip

    2015-01-01

    Cavernous hemangiomas of the anterior mediastinum is rare. We present a case of a 56-year-old male patient with a giant cavernous hemangioma of the anterior mediastinum, 18 cm in diameters, approached by left posterolateral thoracotomy. To the best of our knowledge, such a unique case has not been previously presented in the literature. PMID:26644773

  17. Giant Viruses of Amoebas: An Update

    PubMed Central

    Aherfi, Sarah; Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2016-01-01

    During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea, and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreover, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages. PMID:27047465

  18. Insights on a Giant Aneurysm Treated Endovascularly.

    PubMed

    Graziano, Francesca; Iacopino, Domenico Gerardo; Ulm, Arthur John

    2016-07-01

    Background Endovascular treatment with stent-assisted Guglielmi detachable coils is an accepted method for treating intracranial giant aneurysms that otherwise would require more invasive or destructive treatment or could not be treated at all. Nevertheless, there is a paucity of information concerning inner postcoiling aneurysmal changes in human subjects over the long term. We report a postmortem analysis of a patient with a giant aneurysm at the vertebrobasilar junction (VBJ) who was treated endovascularly and studied pathologically 24 months after treatment. Materials and Method The head was removed at autopsy and prefixed in a 10% neutral buffered formalin solution. The brain was gently removed from the skull base after cutting the intracranial nerves and vascular structures. The giant VBJ aneurysm and its relationship with the brainstem, cranial nerves, and vessels were captured photographically and analyzed. Afterward, under operating microscope guidance, the vertebrobasilar system with the aneurysm was gently and carefully detached from the brainstem and carefully analyzed. Results No complete fibrous obliteration of the aneurysm lumen could be detected in our case, and no endothelialization had taken place 24 months after treatment. Conclusions Our findings agree with those of previous similar reports. Coiling, in particular in large or giant aneurysms, may be burdened by the risk of coil compaction and recanalization, but it has the advantage of not affecting the flow in the perforating arteries.

  19. Tuberculosis Detection by Giant African Pouched Rats

    ERIC Educational Resources Information Center

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  20. Reading on the Shoulders of Giants

    ERIC Educational Resources Information Center

    Ben-Chaim, Michael; Riendeau, Michael

    2012-01-01

    Reflecting on his successful scientific career, Isaac Newton highlighted his intellectual debt to his predecessors. "If I have seen further," he wrote, "it was "only" by standing on the shoulders of giants." The authors have chosen the title of their article as a token of recognition of their debt to the teachings of…

  1. Standing on the shoulders of giants.

    PubMed

    Romanovsky, Andrej A

    2014-01-01

    In this editorial, the author explains that the journal Temperature stands on the shoulders of giants-prominent scientists of the past and current members of the Temperature community. Temperature also uses the best tools, such as Google Scholar profiles. The editorial includes a new puzzle: why does warm water freeze faster than cold water?

  2. Recovery From Giant Eruptions in Massive Stars

    NASA Astrophysics Data System (ADS)

    Kashi, A.; Davidson, K.; Humphreys, R. M.

    2015-12-01

    We perform radiation hydrodynamic simulations to study how very massive stars recover from giant eruptions. The post eruption star experience strong mass loss due to strong winds, driven by radial pulsations in the star*s interior, that operate by the κ-mechanism. The mass loss history obtained in our simulations resembles η Car*s history.

  3. [Habitat selection attributes of giant panda].

    PubMed

    Kang, Dong-Wei; Zhao, Zhi-Jiang; Guo, Wen-Xia; Tan, Liu-Yi; Kang, Wen; Li, Jun-Qing

    2011-02-01

    Based on the 1997-2009 inventory data of Wanglang Nature Reserve, the habitat selection attributes of giant panda were studied from the aspects of topography, forest community structure, and main feeding bamboo by the methods of frequency distribution and Bailey. The giant panda had obvious habitat preferences. Topographically, the preferred microhabitat was on the even or convex slopes at the ridge, top, or middle part of mountain body at an elevation 2500-3000 m, with southwest aspect, 6 degrees-30 degrees, and the distance to the nearest water source > 300 m. As for the forest community structure, the giant panda preferred the microhabitat with the bamboo succeeded from secondary forest or mixed conifer and broad-leaved forest, and with the average tree height being 20-29 m and the shrub coverage being 0-24%. The preferred main feeding bamboo by the giant panda was the growing well Fargesia denudate with an average height of 2-5 m and the coverage of > 50%.

  4. Assimilation of planets by red giant stars

    NASA Astrophysics Data System (ADS)

    Carlberg, Joleen Karen

    The typical red giant star rotates slowly. This characteristic is expected from the conservation of angular momentum as these stars expand during their evolution. Nevertheless, a small percentage of red giant stars are rapidly rotating. One possible source of these stars' excess angular momenta is the orbital angular momentum of a planetary companion. The transfer of orbital angular momentum to the stellar envelope decays the planet's orbit, ultimately leading to the rapid in-spiral of the planet into the star. Using the known sample of exoplanets around main sequence host stars, I simulated both the future evolution of these stars and the expected interactions with their planets and found that Jupiter-mass planets residing at inner solar system distances---relatively common in exoplanetary systems---can contribute enough angular momentum to cause rapid rotation in their host stars during the red giant phase. Gas giant planets are also massive enough to alter the chemical composition of their host stars' envelopes when they are accreted. The central experiment of this thesis is to search for abundance anomalies in the rapid rotators that could be indicative of planet accretion. Hypothetical anomalies include the replenishment of light elements that are diluted by giant stars during first dredge-up (such as the stellar surface abundance of lithium), changes in isotopic abundance ratios that were altered by nucleosynthesis (such as increasing the stellar surface 12C/13C), and the preferential enhancement of refractory elements (indicative of the accretion of chemically fractionated material such as a planet). To increase the total number of known rapid rotators, I measured rotational velocities in a large database of spectra collected for the Grid Giant Star Survey developed for NASA's Space Interferometry Mission's astrometric grid. The 28 new rapid rotators discovered in this sample were combined with rapid rotators from the literature and a control sample of slow

  5. Measuring and modeling the spatial pattern of understory bamboo across landscapes: Implications for giant panda habitat

    NASA Astrophysics Data System (ADS)

    Linderman, Marc Alan

    We examined an approach to classifying understory bamboo, the staple food of the giant panda (Ailuropoda melanoleuca), from remote sensing imagery in the Wolong Nature Reserve, China. We also used these data to estimate the landscape-scale distribution of giant panda habitat, and model the human effects on forest cover and the spatio-temporal dynamics of bamboo and the resulting implications for giant panda habitat. The spatial distribution of understory bamboo was mapped using an artificial neural network and leaf-on remote sensing data. Training on a limited set of ground truth data and using widely available Landsat TM data as input, a non-linear artificial neural network achieved a classification accuracy of 80% despite the presence of co-occurring mid-story and understory vegetation. Using information on the spatial distribution of bamboo in Wolong, we compared the results of giant panda habitat analyses with and without bamboo information. Total amount of habitat decreased by 29--56% and overall habitat patch size decreased by 16--48% after bamboo information was incorporated into the analyses. The decreases in the quantity of panda habitat and increases in habitat fragmentation resulted in decreases of 41--60% in carrying capacity. Using a spatio-temporal model of bamboo dynamics and human activities, we found that local fuelwood collection and household creation will likely reduce secondary habitat relied upon by pandas. Human impacts would likely contribute up to an additional 16% loss of habitat. Furthermore, these impacts primarily occur in the habitat relied upon by giant pandas during past bamboo die-offs. Decreased total area of habitat and increased fragmentation from human activities will likely make giant pandas increasingly sensitive to natural disturbances such as cyclical bamboo die-offs. Our studies suggest that it is necessary to further examine approaches to monitor understory vegetation and incorporate understory information into wildlife

  6. Independent coding of wind direction in cockroach giant interneurons.

    PubMed

    Mizrahi, A; Libersat, F

    1997-11-01

    Independent coding of wind direction in cockroach giant interneurons. J. Neurophysiol. 78: 2655-2661, 1997. In this study we examined the possible role of cell-to-cell interactions in the localization processing of a wind stimulus by the cockroach cercal system. Such sensory processing is performed primarily by pairs of giant interneurons (GIs), a group of highly directional cells. We have studied possible interactions among these GIs by comparing the wind sensitivity of a given GI before and after removing another GI with the use of photoablation. Testing various combinations of GI pairs did not reveal any suprathreshold interactions. This was true for all unilateral GI pairs on the left or right side as well as all the bilateral GI pairs (left and right homologues). Those experiments in which we were able to measure synaptic activity did not reveal subthreshold interactions between the GIs either. We conclude that the GIs code independently for a given wind direction without local GI-GI interactions. We discuss the possible implications of the absence of local interactions on information transfer in the first station of the escape circuit.

  7. Spectroscopy of chromospheric lines of giants in the globular cluster

    NASA Technical Reports Server (NTRS)

    Dupree, A. K.; Hartmann, Lee; Smith, Graeme H.; Rodgers, A. W.; Roberts, W. H.; Zucker, D. B.

    1994-01-01

    Spectroscopic observations of chromospheric transitions (Mg II, H-alpha, and Ca II K) from two red giants (A31 and A59) in the globular cluster NGC 6572 were made with the Goddard High Resolution Spectrograph on the Hubble Space Telescope and the coude spectrograph of the 1.9 m telescope at the Mount Stromlo Observatory. These measurements give evidence for chromospheric activity and outward motions within the atmospheres. The surface flux of the Mg II emission is comparable to that in disk population giants of similar (B-V) color. The Mg II profiles are asymmetric, which is most likely caused by absorption in an expanding stellar atmosphere and/or by possible interstellar features. Notches are found in the core of the H-alpha line of A59, which are similar to those found in Cepheids. This suggests that shocks are present in the atmosphere of A59 and indicates that hydrodynamic phenomena are influencing the levvel of chromospheric emission and producing upper atmospheric motions which may lead to mass loss.

  8. Giant deep-sea protist produces bilaterian-like traces.

    PubMed

    Matz, Mikhail V; Frank, Tamara M; Marshall, N Justin; Widder, Edith A; Johnsen, Sönke

    2008-12-09

    One of the strongest paleontological arguments in favor of the origin of bilaterally symmetrical animals (Bilateria) prior to their obvious and explosive appearance in the fossil record in the early Cambrian, 542 million years ago, is the occurrence of trace fossils shaped like elongated sinuous grooves or furrows in the Precambrian. Being restricted to the seafloor surface, these traces are relatively rare and of limited diversity, and they do not show any evidence of the use of hard appendages. They are commonly attributed to the activity of the early nonskeletonized bilaterians or, alternatively, large cnidarians such as sea anemones or sea pens. Here we describe macroscopic groove-like traces produced by a living giant protist and show that these traces bear a remarkable resemblance to the Precambrian trace fossils, including those as old as 1.8 billion years. This is the first evidence that organisms other than multicellular animals can produce such traces, and it prompts re-evaluation of the significance of Precambrian trace fossils as evidence of the early diversification of Bilateria. Our observations also render indirect support to the highly controversial interpretation of the enigmatic Ediacaran biota of the late Precambrian as giant protists.

  9. The clinical approach toward giant cell tumor of bone.

    PubMed

    van der Heijden, Lizz; Dijkstra, P D Sander; van de Sande, Michiel A J; Kroep, Judith R; Nout, Remi A; van Rijswijk, Carla S P; Bovée, Judith V M G; Hogendoorn, Pancras C W; Gelderblom, Hans

    2014-05-01

    We provide an overview of imaging, histopathology, genetics, and multidisciplinary treatment of giant cell tumor of bone (GCTB), an intermediate, locally aggressive but rarely metastasizing tumor. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated giant cells. Conventional radiographs show a typical eccentric lytic lesion, mostly located in the meta-epiphyseal area of long bones. GCTB may also arise in the axial skeleton and very occasionally in the small bones of hands and feet. Magnetic resonance imaging is necessary to evaluate the extent of GCTB within bone and surrounding soft tissues to plan a surgical approach. Curettage with local adjuvants is the preferred treatment. Recurrence rates after curettage with phenol and polymethylmethacrylate (PMMA; 8%-27%) or cryosurgery and PMMA (0%-20%) are comparable. Resection is indicated when joint salvage is not feasible (e.g., intra-articular fracture with soft tissue component). Denosumab (RANKL inhibitor) blocks and bisphosphonates inhibit GCTB-derived osteoclast resorption. With bisphosphonates, stabilization of local and metastatic disease has been reported, although level of evidence was low. Denosumab has been studied to a larger extent and seems to be effective in facilitating intralesional surgery after therapy. Denosumab was recently registered for unresectable disease. Moderate-dose radiotherapy (40-55 Gy) is restricted to rare cases in which surgery would lead to unacceptable morbidity and RANKL inhibitors are contraindicated or unavailable.

  10. Simultaneous formation of solar system giant planets

    NASA Astrophysics Data System (ADS)

    Guilera, O. M.; Fortier, A.; Brunini, A.; Benvenuto, O. G.

    2011-08-01

    Context. In the last few years, the so-called "Nice model" has become increasingly significant for studying the formation and evolution of the solar system. According to this model, the initial orbital configuration of the giant planets was much more compact than the one we observe today. Aims: We study the formation of the giant planets in connection with several parameters that describe the protoplanetary disk. We aim to establish which conditions enable their simultaneous formation in line with the initial configuration proposed by the Nice model. We focus on the conditions that lead to the simultaneous formation of two massive cores, corresponding to Jupiter and Saturn, which are able to reach the cross-over mass (where the mass of the envelope of the giant planet equals the mass of the core, and gaseous runway starts), while two other cores that correspond to Uranus and Neptune have to be able to grow to their current masses. Methods: We compute the in situ planetary formation, employing the numerical code introduced in our previous work for different density profiles of the protoplanetary disk. Planetesimal migration is taken into account and planetesimals are considered to follow a size distribution between r_pmin (free parameter) and r_pmax= 100 km. The core's growth is computed according to the oligarchic growth regime. Results: The simultaneous formation of the giant planets was successfully completed for several initial conditions of the disk. We find that for protoplanetary disks characterized by a power law (Σ ∝ r - p), flat surface density profiles (p ≤ 1.5) favor the simultaneous formation. However, for steep slopes (p 2, as previously proposed by other authors) the simultaneous formation of the solar system giant planets is unlikely. Conclusions: The simultaneous formation of the giant planets - in the context of the Nice model - is favored by flat surface density profiles. The formation time-scale agrees with the estimates of disk lifetimes if

  11. Giant oil fields of the Gulf Coast area

    SciTech Connect

    Haeberle, F.R.

    1993-09-01

    The 134 giant fields in the Gulf Coastal area contain 29% of the total giant-field reserves. Cumulative production is 32% of the giant-field cumulative total and 20% of the United States cumulative production. Eighty-nine of the giant fields are offshore with 22% of the reserves, 11 fields are in east Texas with 24% of the reserves, and 1 field is in Florida with 1% of the reserves. In 106 of the giant fields the primary producing interval is Cenozoic with 65% of the reserves, and in 28 giant fields the producing interval is Mesozoic with 35% of the reserves. The primary producing interval is Mesozoic with 35% of the reserves. The primary producing interval in 124 giant fields consists of clastics with 91% of the reserves, in 7 fields the primary lithology is carbonates with 6% of the reserves, and in 3 giant fields the lithology is mixed clastics and carbonates. A total of 127 fields are in structural traps with all of the reserves, 4 fields are stratigraphic traps (3%) with 18% of the reserves, and 3 fields are combination traps with 1% of the reserves. Over 50 of the giant oil fields in structural traps are salt domes. The most prevalent types of giant fields in the Gulf Coastal area are onshore structural traps with Cenozoic clastics as the primary producing intervals.

  12. Quasar feedback revealed by giant molecular outflows

    NASA Astrophysics Data System (ADS)

    Feruglio, C.; Maiolino, R.; Piconcelli, E.; Menci, N.; Aussel, H.; Lamastra, A.; Fiore, F.

    2010-07-01

    In the standard scenario for galaxy evolution young star-forming galaxies transform into red bulge-dominated spheroids, where star formation has been quenched. To explain this transformation, a strong negative feedback generated by accretion onto a central super-massive black hole is often invoked. The depletion of gas resulting from quasar-driven outflows should eventually stop star-formation across the host galaxy and lead the black hole to “suicide” by starvation. Direct observational evidence for a major quasar feedback onto the host galaxy is still missing, because outflows previously observed in quasars are generally associated with the ionized component of the gas, which only accounts for a minor fraction of the total gas content, and typically occurrs in the central regions. We used the IRAM PdB Interferometer to observe the CO(1-0) transition in Mrk 231, the closest quasar known. Thanks to the wide band we detected broad wings of the CO line, with velocities of up to 750 km s-1 and spatially resolved on the kpc scale. These broad CO wings trace a giant molecular outflow of about 700 M_⊙/year, far larger than the ongoing star-formation rate (~200 M_⊙/year) observed in the host galaxy. This wind will totally expel the cold gas reservoir in Mrk 231 in about 107 yrs, therefore halting the star-formation activity on the same timescale. The inferred kinetic energy in the molecular outflow is ~1.2 × 1044 erg/s, corresponding to a few percent of the AGN bolometric luminosity, which is very close to the fraction expected by models ascribing quasar feedback to highly supersonic shocks generated by radiatively accelerated nuclear winds. Instead, the contribution by the SNe associated with the starburst fall short by several orders of magnitude to account for the kinetic energy observed in the outflow. The direct observational evidence for quasar feedback reported here provides solid support to the scenarios ascribing the observed properties of local massive

  13. Lunar mascons as consequences of giant impacts

    NASA Technical Reports Server (NTRS)

    Arkani-Hamed, J.

    1974-01-01

    An investigation is conducted regarding the effect of a giant impact on the thermal evolution of the moon. A model is proposed for the formation of the lunar mascons. The model takes into account the evidence of late volcanism during a period from about 3.7 to about 3.2 b.y. ago. It is found that a giant impact produces extensive fracturing in the region surrounding the basin and reduces the average thermal conductivity of the upper 20 km of this region by a factor of about 2. The less conductive ejecta blanket and the fractured zone behave as a thermal insulator. The lithosphere beneath the basin thickens monotonically and it becomes strong enough to support the mascon.

  14. Formation of gas and ice giant planets

    NASA Astrophysics Data System (ADS)

    Boss, Alan P.

    2003-10-01

    The only presently known example of a planetary system containing a terrestrial planet in the habitable zone of a main sequence star is the Solar System. If the Solar System's giant planets formed by the generally assumed mechanism of core accretion, the Solar System probably formed in a relatively long-lived protoplanetary disk in a quiescent region of star formation, such as in the Taurus molecular cloud. However, if the giant planets formed by the more radical disk instability mechanism, then the Solar System would have formed in a region of high mass star formation, similar to the Orion Nebula Cluster or the Carina Nebula. In the latter case, the number of extrasolar planetary systems strongly resembling our own is likely to be significantly larger than in the former case, with important implications for the design of Darwin/TPF.

  15. Viral metagenomics: are we missing the giants?

    PubMed

    Halary, S; Temmam, S; Raoult, D; Desnues, C

    2016-06-01

    Amoeba-infecting giant viruses are recently discovered viruses that have been isolated from diverse environments all around the world. In parallel to isolation efforts, metagenomics confirmed their worldwide distribution from a broad range of environmental and host-associated samples, including humans, depicting them as a major component of eukaryotic viruses in nature and a possible resident of the human/animal virome whose role is still unclear. Nevertheless, metagenomics data about amoeba-infecting giant viruses still remain scarce, mainly because of methodological limitations. Efforts should be pursued both at the metagenomic sample preparation level and on in silico analyses to better understand their roles in the environment and in human/animal health and disease.

  16. Giant viruses of the Kutch Desert.

    PubMed

    Kerepesi, Csaba; Grolmusz, Vince

    2016-03-01

    The Kutch Desert (Great Rann of Kutch, Gujarat, India) is a unique ecosystem: in the larger part of the year it is a hot, salty desert that is flooded regularly in the Indian monsoon season. In the dry season, the crystallized salt deposits form the "white desert" in large regions. The first metagenomic analysis of the soil samples of Kutch was published in 2013, and the data were deposited in the NCBI Sequence Read Archive. At the same time, the sequences were analyzed phylogenetically for prokaryotes, especially for bacteria. In the present work, we identified DNA sequences of recently discovered giant viruses in the soil samples from the Kutch Desert. Since most giant viruses have been discovered in biofilms in industrial cooling towers, ocean water, and freshwater ponds, we were surprised to find their DNA sequences in soil samples from a seasonally very hot and arid, salty environment.

  17. Mass loss from warm giants: Magnetic effects

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1980-01-01

    Among warm giant stars, rapid mass loss sets in along a well defined velocity dividing line (VDL). Hot corona also disappear close to the VDL and thermal pressure cannot drive the observed rapid mass loss in these stars. The VDL may be associated with magnetic fields changing from closed to open. Such a change is consistent with the lack of X-rays from late-type giants. A magnetic transition locus based on Pneuman's work on helmet streamer stability agrees well with the empirical VDL. The change from closed to open fields not only makes rapid mass loss possible, but also contributes to energizing the mass loss in the form of discrete bubbles.

  18. Imaging of giant cell tumor of bone

    PubMed Central

    Purohit, Shaligram; Pardiwala, Dinshaw N

    2007-01-01

    Giant cell tumor (GCT) of bone is a benign but locally aggressive and destructive lesion generally occurring in skeletally mature individuals. Typically involving the epiphysiometaphyseal region of long bones, the most common sites include the distal femur, proximal tibia and distal radius. On radiographs, GCT demonstrates a lytic lesion centered in the epiphysis but involving the metaphysis and extending at least in part to the adjacent articular cortex. Most are eccentric, but become symmetric and centrally located with growth. Most cases show circumscribed borders or so-called geographical destruction with no periosteal reaction unless a pathological fracture is present. There is no mineralized tumor matrix. Giant cell tumor can produce wide-ranging appearances depending on site, complications such as hemorrhage or pathological fracture and after surgical intervention. This review demonstrates a spectrum of these features and describes the imaging characteristics of GCT in conventional radiographs, computerized tomography scans, magnetic resonance imaging, bone scans, positron emission tomography scans and angiography. PMID:21139758

  19. Thermal escape from extrasolar giant planets

    PubMed Central

    Koskinen, Tommi T.; Lavvas, Panayotis; Harris, Matthew J.; Yelle, Roger V.

    2014-01-01

    The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres. PMID:24664923

  20. Giant vortex state in mesoscopic superconductors

    NASA Astrophysics Data System (ADS)

    Cobacy García, Luis; Giraldo, Jairo

    2005-08-01

    Using the self-consistent solution of the nonlinear Ginzburg-Landau equations, the superconducting state of a type II mesoscopic cylinder and of an infinite thin sheet with a circular hole (antidot), in the presence of an homogeneous magnetic field is studied. Close to the third critical field, the magnetic field penetrates the sample in the form of a vortex around the axis of the cylinder or of the antidot. This result has been found previously by other authors. The vortex, called a giant vortex, can carry several flux quanta. The giant vortex is persistent when the state is metastable and evolves to the so called paramagnetic Meissner effect (PME) within the cylinder. The behaviour of this effect as a function of the Ginzburg-Landau (GL) parameter is studied and the results are discussed. Gibbs free energy, order parameter and magnetic induccion as a function of the applied field and of the GL parameter are also studied.

  1. Giant radio galaxies and cosmic web

    NASA Astrophysics Data System (ADS)

    Heinämäki, Pekka

    2016-10-01

    Giant radio galaxies create the welldistinguishable class of sources.These sources are characterized with edge-brightened radio lobes withhighly collimated radio jets and large linear sizes which make themthe largest individual structures in the Universe. They are also knownto be hosted by elliptical/disturbed host galaxies and avoid clustersand high galaxy density regions. Because of GRG, large linear sizeslobes extend well beyond the interstellar media and host galaxyhalo the evolution of the radio lobes may depend on interactionwith this environment. Using our method to extract filamentarystructure of the galaxies in our local universe we study whetherradio lobe properties in some giant radio galaxies are determinedon an interaction of this filament ambient.

  2. [Giant Meckel's diverticulum in an adult].

    PubMed

    Rivas, Tomas Contreras; Gallardo, Nasser Eluzen; Valenzuela, Sebastian King; Pezoa, María Elena Molina; Zúñiga, José Miguel; Muñoz, Carol Bustamante; Saralic, Biserka Spralja

    2014-10-07

    Meckel's diverticulum results from a partial persistence of the omphalomesenteric duct and is the most common congenital anomaly of the gastrointestinal tract, affecting about 2% of the general population. Its presentation as a giant Meckel's diverticulum (>5 cm) is rare and is associated with major complications. We report a case of a 53 year-old woman with constipation for at least ten years. A colonoscopy from eight years ago suggested megacolon. The patient consults in the last month for abdominal pain associated with anorexia. The computed tomography scan image suggested an ileal megadiverticulum. An exploratory laparotomy revealed a saccular dilatation of the distal ileum of 6 x 15.5 cm, located 20 cm away from the ileocecal valve. We resected the involved segment of distal ileum and performed a manual ileo-ascendo anastomosis. The biopsy showed a saccular dilatation of the wall, lined by small intestinal mucosa with areas of gastric metaplasia, supporting the diagnosis of giant Meckel's diverticulum.

  3. Thermal escape from extrasolar giant planets.

    PubMed

    Koskinen, Tommi T; Lavvas, Panayotis; Harris, Matthew J; Yelle, Roger V

    2014-04-28

    The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres.

  4. Isolated giant molluscum contagiosum mimicking epidermoid cyst

    PubMed Central

    Uzuncakmak, Tugba K.; Kuru, Burce C.; Zemheri, Ebru I.; Zindanci, Ilkin; Turkoglu, Zafer; Kavala, Mukaddes

    2016-01-01

    Molluscum contagiosum is a benign cutaneous viral infection which is caused by double- stranded DNA poxvirus. It affects mainly children and young adults and usually presents with single or multiple umblicated papules or nodules on face, arms, legs and anogenital regions. It may present in atypical size and clinical appearance in patients with altered or impaired immunity and rarely in immuncompetent patients. Herein we present an immuncompetent young adult patient with isolated giant molluscum contagiosum, which was mimicking epidermoid cyst clinically. PMID:27648389

  5. Immunocytochemical study of giant cell fibroma.

    PubMed

    Campos, E; Gomez, R S

    1999-01-01

    Giant cell fibroma (GCF) is a non-neoplastic lesion of the oral mucosa. The origin of stellate and multinucleate cells of GCF is not well known. The purpose of the present article was to investigate the immunoreactivity of these cells for leukocyte common antigen, vimentin, tryptase, HLA-DR, alpha-smooth muscle actin, CD68, and S-100. The results showed positive staining only for vimentin. This suggests that the stellate and multinucleate cells of GCF have a fibroblast phenotype.

  6. Giant Kerr nonlinearities in circuit quantum electrodynamics.

    PubMed

    Rebić, Stojan; Twamley, Jason; Milburn, Gerard J

    2009-10-09

    The very small size of optical nonlinearities places strict restrictions on the types of novel physics one can explore. This work describes how a single artificial multilevel Cooper pair box molecule, interacting with a superconducting microwave coplanar resonator, when suitably driven, can generate extremely large optical nonlinearities at microwave frequencies, with no associated absorption. We describe how the giant self-Kerr effect can be detected by measuring the second-order correlation function and quadrature squeezing spectrum.

  7. Giant optical nonlinearity of plasmonic nanostructures

    SciTech Connect

    Melentiev, P N; Afanasev, A E; Balykin, V I

    2014-06-30

    The experimental studies of giant optical nonlinearity of single metal nanostructures are briefly reviewed. A new hybrid nanostructure – split-hole resonator (SHR) – is investigated. This structure is characterised by a record-high efficiency of third-harmonic generation and multiphoton luminescence (its nonlinearity exceeds that of a single nanohole by five orders of magnitude) and an unprecedently high sensitivity to light polarisation (extinction coefficient 4 × 10{sup 4}). (extreme light fields and their applications)

  8. Giant Pleomorphic Adenoma of the Parotid Gland.

    PubMed

    Sajid, Muhammad; Rehman, Sajid; Misbah, Junaid

    2015-10-01

    Salivary gland tumours are a relatively rare entity. Pleomorphic adenoma is the most common amongst these, comprising 60 - 70% of all parotid tumours. Pleomorphic adenomas are benign and tend to increase in size slowly. Here we are presenting a case of giant pleomorphic adenoma of the parotid, being the largest in size to be excised in Pakistan in recorded literature measuring 24 x 22 x 12 cm and weighing 1.8 kgs. Superficial parotidectomy was done with an excellent cosmetic outcome.

  9. Management of giant pseudomeningoceles after spinal surgery

    PubMed Central

    2010-01-01

    Background Pseudomeningoceles are a rare complication after spinal surgery, and studies on these complex formations are few. Methods Between October 2000 and March 2008, 11 patients who developed symptomatic pseudomeningoceles after spinal surgery were recruited. In this retrospective study, we reported our experiences in the management of these complex, symptomatic pseudomeningoceles after spinal surgery. A giant pseudomeningocele was defined as a pseudomeningocele >8 cm in length. We also evaluated the risk factors for the formation of giant pseudomeningoceles. Results All patients were treated successfully with a combined treatment protocol of open revision surgery for extirpation of the pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage. Surgery-related complications were not observed. Recurrence of pseudomeningocele was not observed for any patient at a mean follow-up of 16.5 months. This result was confirmed by magnetic resonance imaging. Conclusions We conclude that a combined treatment protocol involving open revision surgery for extirpation of pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage is safe and effective to treat giant pseudomeningoceles. PMID:20302667

  10. Two cases of giant serpentine aneurysm.

    PubMed

    Kumabe, T; Kaneko, U; Ishibashi, T; Kaneko, K; Uchigasaki, S

    1990-06-01

    Giant serpentine aneurysm (GSA) is an entity defined on radiological and pathological grounds as a giant, partially thrombosed aneurysm containing tortuous vascular channels. We have had the opportunity to study two patients with GSAs, which has allowed for a complete comparative anatomical and radiological study. This report emphasizes the etiology of the GSAs. Twenty-two patients with GSAs have been reported in the literature, of which pathological studies were done in 10. In most of these, the aneurysm was found to be filled with an organized thrombus, but in our patients the aneurysm was filled with relatively new clot. The aneurysm enlarged and a change in the tortuous vascular channel was observed over a period of 1 year in the first patient, whereas a globoid aneurysm developed into a GSA in the brief period of just 2 weeks in the second patient. This rapid transformation of a globoid aneurysm into a GSA is of particular interest when the etiology of GSAs is considered. Our patients therefore shed some interesting light on the possible pathophysiology of GSAs. That is, the bloodstream may change dynamically in a giant aneurysm and may become a serpentine channel under conditions that lead to a "Coanda effect."

  11. Giant Cell Tumor of Bone - An Overview

    PubMed Central

    Sobti, Anshul; Agrawal, Pranshu; Agarwala, Sanjay; Agarwal, Manish

    2016-01-01

    Giant Cell tumors (GCT) are benign tumors with potential for aggressive behavior and capacity to metastasize. Although rarely lethal, benign bone tumors may be associated with a substantial disturbance of the local bony architecture that can be particularly troublesome in peri-articular locations. Its histogenesis remains unclear. It is characterized by a proliferation of mononuclear stromal cells and the presence of many multi- nucleated giant cells with homogenous distribution. There is no widely held consensus regarding the ideal treatment method selection. There are advocates of varying surgical techniques ranging from intra-lesional curettage to wide resection. As most giant cell tumors are benign and are located near a joint in young adults, several authors favor an intralesional approach that preserves anatomy of bone in lieu of resection. Although GCT is classified as a benign lesion, few patients develop progressive lung metastases with poor outcomes. Treatment is mainly surgical. Options of chemotherapy and radiotherapy are reserved for selected cases. Recent advances in the understanding of pathogenesis are essential to develop new treatments for this locally destructive primary bone tumor. PMID:26894211

  12. Social Waves in Giant Honeybees Repel Hornets

    PubMed Central

    Kastberger, Gerald; Schmelzer, Evelyn; Kranner, Ilse

    2008-01-01

    Giant honeybees (Apis dorsata) nest in the open and have evolved a plethora of defence behaviors. Against predatory wasps, including hornets, they display highly coordinated Mexican wave-like cascades termed ‘shimmering’. Shimmering starts at distinct spots on the nest surface and then spreads across the nest within a split second whereby hundreds of individual bees flip their abdomens upwards. However, so far it is not known whether prey and predator interact and if shimmering has anti-predatory significance. This article reports on the complex spatial and temporal patterns of interaction between Giant honeybee and hornet exemplified in 450 filmed episodes of two A. dorsata colonies and hornets (Vespa sp.). Detailed frame-by-frame analysis showed that shimmering elicits an avoidance response from the hornets showing a strong temporal correlation with the time course of shimmering. In turn, the strength and the rate of the bees' shimmering are modulated by the hornets' flight speed and proximity. The findings suggest that shimmering creates a ‘shelter zone’ of around 50 cm that prevents predatory wasps from foraging bees directly from the nest surface. Thus shimmering appears to be a key defence strategy that supports the Giant honeybees' open-nesting life-style. PMID:18781205

  13. Observations of Radio Giant Pulses with GAVRT

    NASA Astrophysics Data System (ADS)

    Jones, Glenn

    2011-08-01

    Radio giant pulses provide a unique opportunity to study the pulsar radio emission mechanism in exquisite detail. Previous studies have revealed a wide range of properties and phenomena, including extraordinarily high brightness temperatures, sub-nanosecond emission features, and banded dynamic spectra. New measurements of giant pulse characteristics can help guide and test theoretical emission models. To this end, an extensive observation campaign has begun which will provide more than 500 hours on the Crab with a 34-meter antenna located in California, USA. The observations are being done as part of an educational outreach program called the Goldstone-Apple Valley Radio Telescope (GAVRT). This antenna has a novel wide bandwidth receiver which provides up to 8 GHz of instantaneous bandwidth in the range of 2.5 to 14 GHz. These observations will provide detailed information about the variability, amplitude distribution, and detailed frequency structure of radio giant pulses. In addition, a database of pulses from these observations and others of the Crab pulsar is being created which will simplify multiwavelength correlation analysis.

  14. Rare cause of odynophagia: Giant esophageal ulcer.

    PubMed

    Veroux, Massimiliano; Aprile, Giuseppe; Amore, Francesca F; Corona, Daniela; Giaquinta, Alessia; Veroux, Pierfrancesco

    2016-04-14

    Gastrointestinal complications are a frequent cause of morbidity after transplantation and may affect up to 40% of kidney transplant recipients. Here we report a rare case of idiopathic giant esophageal ulcer in a kidney transplant recipient. A 37-year-old female presented with a one-week history of odynophagia and weight loss. Upon admission, the patient presented cold sores, and a quantitative cytomegalovirus polymerase chain reaction was positive (10(5) copies/mL). An upper endoscopy demonstrated the presence of a giant ulcer. Serological test and tissue biopsies were unable to demonstrate an infectious origin of the ulcer. Immunosuppression was reduced and everolimus was introduced. An empirical i.v. therapy with acyclovir was started, resulting in a dramatic improvement in symptoms and complete healing of the ulcer. Only two cases of idiopathic giant esophageal ulcer in kidney transplant recipients have been reported in the literature; in both cases, steroid therapy was successful without recurrence of symptoms or endoscopic findings. However, this report suggests that correction of immune imbalance is mandatory to treat such a rare complication.

  15. Giant planet formation via pebble accretion

    NASA Astrophysics Data System (ADS)

    Guilera, O. M.

    2016-08-01

    In the standard model of core accretion, the formation of giant planets occurs by two main processes: first, a massive core is formed by the accretion of solid material; then, when this core exceeds a critical value (typically greater than ) a gaseous runaway growth is triggered and the planet accretes big quantities of gas in a short period of time until the planet achieves its final mass. Thus, the formation of a massive core has to occur when the nebular gas is still available in the disk. This phenomenon imposes a strong time-scale constraint in the giant planet formation due to the fact that the lifetimes of the observed protoplanetary disks are in general lower than 10 Myr. The formation of massive cores before 10 Myr by accretion of big planetesimals (with radii 10 km) in the oligarchic growth regime is only possible in massive disks. However, planetesimal accretion rates significantly increase for small bodies, especially for pebbles, particles of sizes between mm and cm, which are strongly coupled with the gas. In this work, we study the formation of giant planets incorporating pebble accretion rates in our global model of planet formation.

  16. Social waves in giant honeybees repel hornets.

    PubMed

    Kastberger, Gerald; Schmelzer, Evelyn; Kranner, Ilse

    2008-09-10

    Giant honeybees (Apis dorsata) nest in the open and have evolved a plethora of defence behaviors. Against predatory wasps, including hornets, they display highly coordinated Mexican wave-like cascades termed 'shimmering'. Shimmering starts at distinct spots on the nest surface and then spreads across the nest within a split second whereby hundreds of individual bees flip their abdomens upwards. However, so far it is not known whether prey and predator interact and if shimmering has anti-predatory significance. This article reports on the complex spatial and temporal patterns of interaction between Giant honeybee and hornet exemplified in 450 filmed episodes of two A. dorsata colonies and hornets (Vespa sp.). Detailed frame-by-frame analysis showed that shimmering elicits an avoidance response from the hornets showing a strong temporal correlation with the time course of shimmering. In turn, the strength and the rate of the bees' shimmering are modulated by the hornets' flight speed and proximity. The findings suggest that shimmering creates a 'shelter zone' of around 50 cm that prevents predatory wasps from foraging bees directly from the nest surface. Thus shimmering appears to be a key defence strategy that supports the Giant honeybees' open-nesting life-style.

  17. Giant thoracic osteophyte: a distinct clinical entity.

    PubMed

    Coumans, Jean-Valery C E; Neal, Jonathan B; Grottkau, Brian E; Nahed, Brian V; Shin, John H; Walcott, Brian P

    2014-09-01

    Calcified lesions described within the neural axis are classified as either an ossification of the posterior longitudinal ligament, diffuse idiopathic skeletal hyperostosis, or ossification of the ligamentum flavum. We aim to describe a unique pathologic entity: the giant thoracic osteophyte. We identified four patients who were surgically treated at the Massachusetts General Hospital from 2006 to 2012 with unusual calcified lesions in the ventral aspect of the spinal canal. In order to differentiate giant thoracic osteophytes from calcified extruded disc material, disc volumetrics were performed on actual and simulated disc spaces. All patients underwent operative resection of the calcific lesion as they had signs and/or symptoms of spinal cord compression. The lesions were found to be isolated, large calcific masses that originated from the posterior aspect of adjacent thoracic vertebral bodies. Pathological examination was negative for tumor. Adjacent disc volumes were not significantly different from the index disc (p=0.91). A simulated calculation hypothesizing that the calcific mass was extruded disc material demonstrated a significant difference (p=0.01), making this scenario unlikely. In conclusion, giant thoracic osteophyte is a unique and rare entity that can be found in the thoracic spine. The central tenant of surgical treatment is resection to relieve spinal cord compression.

  18. Giant Galaxy's Violent Past Comes Into Focus

    NASA Astrophysics Data System (ADS)

    2004-05-01

    Long-exposure images of the giant elliptical galaxy M87 by NASA's Chandra X-ray Observatory, together with radio observations, have provided spectacular evidence of repetitive outbursts from the vicinity of the galaxy's supermassive black hole. Magnetized rings, bubbles, plumes and jets ranging in size from a few thousand to a few hundred thousand light years point to ongoing violent activity for hundreds of millions of years. "The hot X-ray emitting gas extending for hundreds of thousands of light years around M87 reveals a record of episodes of black hole activity," said Paul Nulsen of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. and an author of an Astrophysical Journal paper describing the latest Chandra observations. "With these detailed observations, we are beginning to understand how the central supermassive black hole transfers enormous amounts of energy over vast reaches of space." M87, located in the middle of the Virgo galaxy cluster, is surrounded by an extensive atmosphere of multi-million degree Celsius gas. Chandra's long-exposure image has allowed astronomers to see in more detail structures discovered by previous observations with Chandra and other X-ray telescopes, to discover new features, and to make specific comparisons with radio images, which trace the presence of high-energy electrons in a magnetic field." X-ray Image of M87 Chandra X-ray Image of M87, Close-Up The picture that emerges is one in which the infall of material toward a central supermassive black hole produces a magnetized jet of high-energy particles that blasts away from the vicinity of the black hole at near the speed of light. As a jet plows into the surrounding gas, a buoyant, magnetized bubble of high-energy particles is created, and an intense sound wave rushes ahead of the expanding bubble. In Chandra's image of M87, X-rays from the jet dominate the central region of the galaxy. The jet is thought to be pointed at a small angle toward the

  19. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

    PubMed Central

    Griffiths, Kate; Hou, Rong; Wang, Hairui; Zhang, Zhihe; Zhang, Liang; Zhang, Tong; Watson, David G.; Burchmore, Richard J. S.; Loeffler, I. Kati; Kennedy, Malcolm W.

    2015-01-01

    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20–30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates. PMID:26587250

  20. Giant panda׳s tooth enamel: Structure, mechanical behavior and toughening mechanisms under indentation.

    PubMed

    Weng, Z Y; Liu, Z Q; Ritchie, R O; Jiao, D; Li, D S; Wu, H L; Deng, L H; Zhang, Z F

    2016-12-01

    The giant panda׳s teeth possess remarkable load-bearing capacity and damage resistance for masticating bamboos. In this study, the hierarchical structure and mechanical behavior of the giant panda׳s tooth enamel were investigated under indentation. The effects of loading orientation and location on mechanical properties of the enamel were clarified and the evolution of damage in the enamel under increasing load evaluated. The nature of the damage, both at and beneath the indentation surfaces, and the underlying toughening mechanisms were explored. Indentation cracks invariably were seen to propagate along the internal interfaces, specifically the sheaths between enamel rods, and multiple extrinsic toughening mechanisms, e.g., crack deflection/twisting and uncracked-ligament bridging, were active to shield the tips of cracks from the applied stress. The giant panda׳s tooth enamel is analogous to human enamel in its mechanical properties, yet it has superior hardness and Young׳s modulus but inferior toughness as compared to the bamboo that pandas primarily feed on, highlighting the critical roles of the integration of underlying tissues in the entire tooth and the highly hydrated state of bamboo foods. Our objective is that this study can aid the understanding of the structure-mechanical property relations in the tooth enamel of mammals and further provide some insight on the food habits of the giant pandas.

  1. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca.

    PubMed

    Griffiths, Kate; Hou, Rong; Wang, Hairui; Zhang, Zhihe; Zhang, Liang; Zhang, Tong; Watson, David G; Burchmore, Richard J S; Loeffler, I Kati; Kennedy, Malcolm W

    2015-10-01

    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20-30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates.

  2. VLA Discovers Giant Rings Around Galaxy Cluster

    NASA Astrophysics Data System (ADS)

    2006-11-01

    Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope have discovered giant, ring-like structures around a cluster of galaxies. The discovery provides tantalizing new information about how such galaxy clusters are assembled, about magnetic fields in the vast spaces between galaxy clusters, and possibly about the origin of cosmic rays. Radio-Optical Image of Cluster Galaxy Cluster Abell 3376 (Radio/Optical) CREDIT: Joydeep Bagchi, IUCAA, NRAO/AUI/NSF Above, a combined radio/optical image shows the galaxy cluster Abell 3376 in visible light (blue) and radio (red) images. The giant radio arcs surrounding the cluster were discovered using the Very Large Array. The visible-light image is from the Digitized Sky survey. Below, an X-ray image of Abell 3376 made using the European Space Agency's XMM-Newton telescope shows a spectacular, bullet-shaped region of X-rays coming from gas heated to 60 million degrees Kelvin. The bullet shape results from the supersonic collision of a smaller smaller galaxy subcluster with the main body of the larger cluster. Click on images for larger version. X-Ray Image of Cluster Galaxy Cluster Abell 3376 (X-Ray) CREDIT: Joydeep Bagchi, IUCAA, ESA "These giant, radio-emitting rings probably are the result of shock waves caused by violent collisions of smaller groups of galaxies within the cluster," said Joydeep Bagchi, of the Inter-University Centre for Astronomy and Astrophysics in Pune, India, who led an international research team. The scientists reported their findings in the November 3 edition of the journal Science. The newly-discovered ring segments, some 6 million light-years across, surround a galaxy cluster called Abell 3376, more than 600 million light-years from Earth. They were revealed because fast-moving electrons emitted radio waves as they spiraled around magnetic field lines in intergalactic space. "Even from this large distance, the feeble radio waves were easily picked up by the VLA

  3. Three cases giant panda attack on human at Beijing Zoo

    PubMed Central

    Zhang, Peixun; Wang, Tianbing; Xiong, Jian; Xue, Feng; Xu, Hailin; Chen, Jianhai; Zhang, Dianying; Fu, Zhongguo; Jiang, Baoguo

    2014-01-01

    Panda is regarded as Chinese national treasure. Most people always thought they were cute and just ate bamboo and had never imagined a panda could be vicious. Giant panda attacks on human are rare. There, we present three cases of giant panda attacks on humans at the Panda House at Beijing Zoo from September 2006 to June 2009 to warn people of the giant panda’s potentially dangerous behavior. PMID:25550978

  4. The identification of K giant stars in LAMOST pilot survey

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Yang, Fan; Deng, Licai; Xu, Yan; Cui, Wenyuan; Xue, Xiangxiang; Gao, Shuang; Zhang, Yueyang; Xin, Yu

    2014-01-01

    A support vector machine (SVM) method is applied to select K giant stars directly from the spectral features of LAMOST spectra. The performance of the algorithm is assessed using the MILES library. It shows that the completeness of the K giant stars is 87% with only about 6% dwarf contamination. This allows us to select 18,013 K giant stars at |b|>20° and 38,108 at |b|<20° from LAMOST pilot survey data.

  5. Three cases giant panda attack on human at Beijing Zoo.

    PubMed

    Zhang, Peixun; Wang, Tianbing; Xiong, Jian; Xue, Feng; Xu, Hailin; Chen, Jianhai; Zhang, Dianying; Fu, Zhongguo; Jiang, Baoguo

    2014-01-01

    Panda is regarded as Chinese national treasure. Most people always thought they were cute and just ate bamboo and had never imagined a panda could be vicious. Giant panda attacks on human are rare. There, we present three cases of giant panda attacks on humans at the Panda House at Beijing Zoo from September 2006 to June 2009 to warn people of the giant panda's potentially dangerous behavior.

  6. Liquid Water Oceans in Ice Giants

    NASA Technical Reports Server (NTRS)

    Wiktorowicz, Sloane J.; Ingersoll, Andrew P.

    2007-01-01

    Aptly named, ice giants such as Uranus and Neptune contain significant amounts of water. While this water cannot be present near the cloud tops, it must be abundant in the deep interior. We investigate the likelihood of a liquid water ocean existing in the hydrogen-rich region between the cloud tops and deep interior. Starting from an assumed temperature at a given upper tropospheric pressure (the photosphere), we follow a moist adiabat downward. The mixing ratio of water to hydrogen in the gas phase is small in the photosphere and increases with depth. The mixing ratio in the condensed phase is near unity in the photosphere and decreases with depth; this gives two possible outcomes. If at some pressure level the mixing ratio of water in the gas phase is equal to that in the deep interior, then that level is the cloud base. The gas below the cloud base has constant mixing ratio. Alternately, if the mixing ratio of water in the condensed phase reaches that in the deep interior, then the surface of a liquid ocean will occur. Below this ocean surface, the mixing ratio of water will be constant. A cloud base occurs when the photospheric temperature is high. For a family of ice giants with different photospheric temperatures, the cooler ice giants will have warmer cloud bases. For an ice giant with a cool enough photospheric temperature, the cloud base will exist at the critical temperature. For still cooler ice giants, ocean surfaces will result. A high mixing ratio of water in the deep interior favors a liquid ocean. We find that Neptune is both too warm (photospheric temperature too high) and too dry (mixing ratio of water in the deep interior too low) for liquid oceans to exist at present. To have a liquid ocean, Neptune s deep interior water to gas ratio would have to be higher than current models allow, and the density at 19 kbar would have to be approx. equal to 0.8 g/cu cm. Such a high density is inconsistent with gravitational data obtained during the Voyager

  7. Analytical model of a giant magnetostrictive resonance transducer

    NASA Astrophysics Data System (ADS)

    Sheykholeslami, M.; Hojjat, Y.; Ansari, S.; Cinquemani, S.; Ghodsi, M.

    2016-04-01

    Resonance transducers have been widely developed and studied, as they can be profitably used in many application such as liquid atomizing and sonar technology. The active element of these devices can be a giant magnetostrictive material (GMM) that is known to have significant energy density and good performance at high frequencies. The paper introduces an analytical model of GMM transducers to describe their dynamics in different working conditions and to predict any change in their performance. The knowledge of the transducer behavior, especially in operating conditions different from the ideal ones, is helpful in the design and fabrication of highly efficient devices. This transducer is design to properly work in its second mode of vibration and its working frequency is around 8000 Hz. Most interesting parameters of the device, such as quality factor, bandwidth and output strain are obtained from theoretical analysis.

  8. Giant Impacts on Earth-Like Worlds

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-05-01

    Earth has experienced a large number of impacts, from the cratering events that may have caused mass extinctions to the enormous impact believed to have formed the Moon. A new study examines whether our planets impact history is typical for Earth-like worlds.N-Body ChallengesTimeline placing the authors simulations in context of the history of our solar system (click for a closer look). [Quintana et al. 2016]The final stages of terrestrial planet formation are thought to be dominated by giant impacts of bodies in the protoplanetary disk. During this stage, protoplanets smash into one another and accrete, greatly influencing the growth, composition, and habitability of the final planets.There are two major challenges when simulating this N-body planet formation. The first is fragmentation: since computational time scales as N^2, simulating lots of bodies that split into many more bodies is very computationally intensive. For this reason, fragmentation is usually ignored; simulations instead assume perfect accretion during collisions.Total number of bodies remaining within the authors simulations over time, with fragmentation included (grey) and ignored (red). Both simulations result in the same final number of bodies, but the ones that include fragmentation take more time to reach that final number. [Quintana et al. 2016]The second challengeis that many-body systems are chaotic, which means its necessary to do a large number of simulations to make statistical statements about outcomes.Adding FragmentationA team of scientists led by Elisa Quintana (NASA NPP Senior Fellow at the Ames Research Center) has recently pushed at these challenges by modeling inner-planet formation using a code that does include fragmentation. The team ran 140 simulations with and 140 without the effects of fragmentation using similar initial conditions to understand how including fragmentation affects the outcome.Quintana and collaborators then used the fragmentation-inclusive simulations to

  9. Seafloor doming driven by active mantle degassing offshore Naples (Italy)

    NASA Astrophysics Data System (ADS)

    Ventura, Guido; Passaro, Salvatore; Tamburrino, Stella; Vallefuoco, Mattia; Tassi, Franco; Vaselli, Orlando; Giannini, Luciano; Caliro, Stefano; Chiodini, Giovanni; Sacchi, Marco; Rizzo, Andrea

    2016-04-01

    Structures and processes associated with shallow water hydrothermal fluid discharges on continental shelves are poorly known. We report geomorphological, geophysical, and geochemical evidences of a 5.5 x 5.3 km seabed doming located 5 km offshore the Naples harbor (Italy). The dome lies between 100 and 170 m of water depth and it is 15-20 m higher than the surrounding seafloor. It is characterized by a hummocky morphology due to 280 sub-circular to elliptical mounds, about 660 cones, and 30 pockmarks. The mounds and pockmarks alignments follow those of the main structural discontinuity affecting the Gulf of Naples. The seafloor swelling and breaching require relatively low pressures (about 2-3 MPa), and the sub-seafloor structures, which consists of 'pagodas' affecting the present-day seabed, record the active upraise, pressurization, and release of magmatic fluids. The gas composition of the sampled submarine emissions is consistent with that of the emissions from the hydrothermal systems of Ischia, CampiFlegrei and Somma-Vesuvius active volcanoes, and CO2 has a magmatic/thermometamorphic origin. The 3He/4He ratios (1.66-1.96 Ra) are slightly lower than in the Somma-Vesuvius and Campi Flegrei volcanoes (~2.6-3.0 Ra) indicating the contamination of fluids originated from the same magmatic source by crustal-derived radiogenic 4He. All these evidences concur to hypothesize an extended magmatic reservoir beneath Naples and its offshore. Seabed doming, faulting, and hydrothermal discharges are manifestations of non-volcanic unrests potentially preluding submarine eruptions and/or hydrothermal explosions. We conclude that seabed deformations and hydrothermal discharge must be included in the coastal hazard studies.

  10. Giant Serpentine Aneurysm of the Middle Cerebral Artery

    PubMed Central

    Lee, Seung Joo; Kwun, Byung Duk; Kim, Chang Jin

    2010-01-01

    Giant serpentine aneurysms are rare and have distinct angiographic findings. The rarity, large size, complex anatomy and hemodynamic characteristics of giant serpentine aneurysms make treatment difficult. We report a case of a giant serpentine aneurysm of the right middle cerebral artery (MCA) that presented as headache. Treatment involved a superficial temporal artery (STA)-MCA bypass followed by aneurysm resection. The patient was discharged without neurological deficits, and early and late follow-up angiography disclosed successful removal of the aneurysm and a patent bypass graft. We conclude that STA-MCA bypass and aneurysm excision is a successful treatment method for a giant serpentine aneurysm. PMID:20856671

  11. Giant Inguinal Herniae Managed by Primary Repair: A Case Series

    PubMed Central

    Anand, Madhur; Naku, Narang; Hajong, Debobratta; Singh, K Lenish

    2017-01-01

    Giant inguinal hernia are usually found in developing countries due to delay in seeking medical attention. The management of such hernias may sometimes require procedures to increase the intra-peritoneal capacity prior to the repair of the giant hernia. Otherwise patients may develop abdominal compartment syndrome leading to various unwanted complications. Primary repair of giant hernias are possible in some cases without having significant post-operative complications. In this present case series, we have managed a total of four patients of giant inguinal hernia by primary repair without much post-operative complications. PMID:28384934

  12. Giant pseudomeningocele after spinal surgery: A case report

    PubMed Central

    Srilomsak, Prepram; Okuno, Kazuma; Sakakibara, Toshihiko; Wang, Zhuo; Kasai, Yuichi

    2012-01-01

    Very few reports have described giant pseudomeningoceles ≥ 8 cm in diameter. We report this case of the biggest giant pseudomeningocele at the unusual cervicothoracic level. A 59 year old man who underwent cervicothoracic laminectomy had a giant pseudomeningocele detected and the lesion gradually grew to about 15 cm in diameter by 2 years postoperatively. Cerebrospinal fluid leak closure was performed and the postoperative course was favorable. We present this case, review the literature and discuss the size and portion, mechanism of formation, symptoms and treatments of giant pseudomeningocele. PMID:22816066

  13. Two cases of giant pyogenic granuloma of scalp

    PubMed Central

    Chandra, B. Satish; Rao, P. Narasimha

    2013-01-01

    Pyogenic granuloma is a benign vascular tumor of unknown etiology, though multiple factors play a role in its onset, e.g., trauma, chronic irritation, drugs etc., It is commonly seen in children and adolescents. Giant pyogenic granuloma is its atypical variant. We are presenting two cases of giant pyogenic granuloma, one, in a 28-year-old adult, presenting as a giant fluffy swelling of scalp and the other in a 11-year-old child, presenting as a giant ulcerated globular swelling of the scalp. PMID:24350008

  14. M-giant star candidates identified in LAMOST DR 1

    NASA Astrophysics Data System (ADS)

    Zhong, Jing; Lépine, Sébastien; Li, Jing; Chen, Li; Hou, Jin-Liang; Yang, Ming; Li, Guang-Wei; Zhang, Yong; Hou, Yong-Hui

    2015-08-01

    We perform a discrimination procedure with the spectral index diagram of TiO5 and CaH2+CaH3 to separate M giants from M dwarfs. Using the M giant spectra identified from LAMOST DR1 with high signal-to-noise ratio, we have successfully assembled a set of M giant templates, which show more reliable spectral features. Combining with the M dwarf/subdwarf templates in Zhong et al., we present an extended library of M-type templates which includes not only M dwarfs with a well-defined temperature and metallicity grid but also M giants with subtypes from M0 to M6. Then, the template-fitting algorithm is used to automatically identify and classify M giant stars from LAMOST DR1. The resulting catalog of M giant stars is cross-matched with 2MASS JHKs and WISE W1/W2 infrared photometry. In addition, we calculated the heliocentric radial velocity of all M giant stars by using the cross-correlation method with the template spectrum in a zero-velocity rest frame. Using the relationship between the absolute infrared magnitude MJ and our classified spectroscopic subtype, we derived the spectroscopic distance of M giants with uncertainties of about 40%. A catalog of 8639 M giants is provided. As an additional result of this analysis, we also present a catalog of 101 690 M dwarfs/subdwarfs which are processed by our classification pipeline.

  15. Giant multinucleated macrophages occur in acute spinal cord injury.

    PubMed

    Leskovar, A; Turek, J; Borgens, R B

    2001-05-01

    Using a cell-isolation and -culture procedure specific for macrophages, we report the existence of giant (more than 50 microm diameter), multinucleated macrophages within an acute, 5-day-old adult rat spinal cord injury. The size and multinuclearity of these isolated giant cells was confirmed using transmission electron microscopy. Giant macrophages are markers for long-term infection, disease, and chronic injury in other soft tissues and are unexpected in the acute inflammatory stage of central nervous system injury. To our knowledge, this descriptive report is the first confirming the existence of giant macrophages in any injured nervous tissue, with additional data suggesting some of these cells to be multinucleated.

  16. Exotic Earths: forming habitable worlds with giant planet migration.

    PubMed

    Raymond, Sean N; Mandell, Avi M; Sigurdsson, Steinn

    2006-09-08

    Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.

  17. Adaptive Optics Educational Outreach and the Giant Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Sparks, R. T.; Pompea, S. M.; Walker, C. E.

    2008-06-01

    One of the limiting factors in telescope performance is atmospheric seeing. Atmospheric seeing limits the resolution of ground based optical telescopes. Even telescopes in good locations on top of mountains cannot achieve diffraction-limited resolution. Until recently, the only way to overcome this limitation was to use space-based telescopes. Adaptive Optics (AO) is a collection of technologies that measure the turbulence of Earth's atmosphere and compensate for the turbulence, resulting in high-resolution images without the expense and complexity of space based telescopes. Our Hands-On Optics program has developed activities that teach students how telescopes form images and make observations about the resolution of a telescope. We are developing materials for high school students to use in the study of adaptive optics. These activities include various ways to illustrate atmospheric distortion by using everyday materials such as bubble wrap and mineral oil. We will also illustrate how to demonstrate the workings of a Shack-Hartman sensor to measure atmospheric distortion through the use of a unique model. We will also show activities illustrating two techniques astronomers use to improve the image: tip-tilt mirrors and deformable mirrors. We are developing an activity where students learn how to use a tip-tilt mirror to keep an image focused at one point on a screen. The culminating activity has students learn to use a deformable mirror to correct a distorted wavefront. These activities are being developed in conjunction with the Education program for the Giant Segmented Mirror Telescope (GSMT).

  18. Biophysical characterisation of electrofused giant HEK293-cells as a novel electrophysiological expression system

    SciTech Connect

    Zimmermann, D.; Terpitz, U.; Zhou, A.; Reuss, R.; Mueller, K.; Sukhorukov, V.L.; Gessner, P.; Nagel, G.; Zimmermann, U.; Bamberg, E. . E-mail: ernst.bamberg@mpibp-frankfurt.mpg.de

    2006-09-22

    Giant HEK293 cells of 30-65 {mu}m in diameter were produced by three-dimensional multi-cell electrofusion in 75 mOsm sorbitol media. These strong hypotonic conditions facilitated fusion because of the spherical shape and smooth membrane surface of the swollen cells. A regulatory volume decrease (RVD), as observed at higher osmolalities, did not occur at 75 mOsm. In contrast to field-treated, but unfused cells, the increase in volume induced by hypotonic shock was only partly reversible in the case of fused giant cells after their transfer into isotonic medium. The large size of the electrofused cells allowed the study of their electrophysiological properties by application of both whole-cell and giant excised patch-clamp techniques. Recordings on giant cells yielded a value of 1.1 {+-} 0.1 {mu}F/cm{sup 2} for the area-specific membrane capacitance. This value was consistent with that of the parental cells. The area-specific conductivity of giant cells (diameter > 50 {mu}m) was found to be between 12.8 and 16.1 {mu}S/cm{sup 2}, which is in the range of that of the parental cells. Measurements with patch-pipettes containing fluorescein showed uniform dye uptake in the whole-cell configuration, but not in the cell-attached configuration. The diffusion-controlled uniform uptake of the dye into the cell interior excludes internal compartmentalisation. The finding of a homogeneous fusion was also supported by expression of the yellow fluorescent protein YFP (as part of the fusion-protein ChR2-YFP) in giant cells since no plasma-membrane bound YFP-mediated fluorescence was detected in the interior of the electrofused cells. Functional expression and the electrophysiological characterisation of the light-activated cation channel Channelrhodopsin 2 (ChR2) yielded similar results as for parental cells. Most importantly, the giant cells exhibited a comparable expression density of the channel protein in the plasma membrane as observed in parental cells. This demonstrates that

  19. Immunological responses and protection in Chinese giant salamander Andrias davidianus immunized with inactivated iridovirus.

    PubMed

    Liu, Wenzhi; Xu, Jin; Ma, Jie; LaPatra, Scott E; Meng, Yan; Fan, Yuding; Zhou, Yong; Yang, Xin; Zeng, Lingbing

    2014-12-05

    Chinese giant salamander hemorrhage is a newly emerged infectious disease in China and has caused huge economic losses. The causative pathogen has been identified as the giant salamander iridovirus (GSIV). In this study, the immunological responses and protection in Chinese giant salamander immunized with β-propiolactone inactivated GSIV are reported. Red and white blood cell counting and classification, phagocytic activity, neutralizing antibody titration, immune-related gene expression and determination of the relative percent survival were evaluated after vaccination. The red and white blood cell counts showed that the numbers of erythrocytes and leukocytes in the peripheral blood of immunized Chinese giant salamanders increased significantly on days 4 and 7 post-injection (P<0.01). Additionally, the differential leukocyte count of monocytes and neutrophils were significantly different compared to the control group (P<0.01); the percentage of lymphocytes was 70.45±7.52% at day 21. The phagocytic percentage and phagocytic index was 38.78±4.33% and 3.75±0.52, respectively, at day 4 post-immunization which were both significantly different compared to the control group (P<0.01). The serum neutralizing antibody titer increased at day 14 post-immunization and reached the highest titer (341±9.52) at day 21. The quantitative PCR analysis revealed that the immunization significantly up-regulated the expression of immune related genes TLR-9 and MyD88 the first two weeks after immunization. The challenge test conducted at day 30 post-injection demonstrated that the immunized group produced a relative survival of 72%. These results indicate that the inactivated GSIV could elicit significant non-specific and specific immunological responses in Chinese giant salamander that resulted in significant protection against GSIV induced disease.

  20. Three ferritin subunit analogs in Chinese giant salamander (Andrias davidianus) and their response to microbial stimulation.

    PubMed

    You, Xiuling; Sheng, Jianghong; Liu, Liu; Nie, Dongsong; Liao, Zhiyong

    2015-10-01

    Ferritin, an evolutionarily conserved iron-binding protein, plays important roles in iron storage and detoxification and in host immune response to invading stimulus as well. In the present study, we identified three ferritin subunit analog cDNAs from Chinese giant salamander (Andrias davidianus). All the three ferritin subunit cDNAs had a putative iron responsive element in the 5'-untranslated region. Two deduced ferritin subunits (designated as cgsFerH and cgsFerM) had the highest identity of 90% to H type subunit of vertebrate ferritins, while another deduced ferritin subunit (designated as cgsFerL) had the highest identity of 84% to L type subunit of vertebrate ferritins. The Chinese giant salamander ferritin (cgsFer) was widely expressed in various tissues, with highest expression for cgsFerH and cgsFerL in liver and highest expression for cgsFerM in spleen. Infection of Chinese giant salamander with A. davidianus ranavirus showed significant induction of cgsFer expression. Both lipopolysaccharide and iron challenge drastically augmented cgsFer expression in the splenocytes and hepatocytes from Chinese giant salamander. In addition, recombinant cgsFers bound to ferrous iron in a dose-dependent manner, with significant ferroxidase activity. Furthermore, the recombinant cgsFer inhibited the growth of the pathogen Vibrio anguillarum. These results indicated that cgsFer was potential candidate of immune molecules involved in acute phase response to invading microbial pathogens in Chinese giant salamander possibly through its regulatory roles in iron homeostasis.

  1. Arbuscular mycorrhizal colonization of giant sequoia (Sequoiadendron giganteum) in response to restoration practices.

    PubMed

    Fahey, Catherine; York, Robert A; Pawlowska, Teresa E

    2012-01-01

    Interactions with soil microbiota determine the success of restoring plants to their native habitats. The goal of our study was to understand the effects of restoration practices on interactions of giant sequoia Sequoiadendron giganteum with arbuscular mycorrhizal (AM) fungi (Glomeromycota). Natural regeneration of Sequoiadendron is threatened by the absence of severe fires that create forest canopy gaps. Generating artificial canopy gaps offers an alternative tool for giant sequoia restoration. We investigated the effect of regeneration practices, including (i) sapling location within gaps, (ii) gap size and (iii) soil substrate, on AM fungal colonization of giant sequoia sapling roots in a native giant sequoia grove of the Sierra Nevada, California. We found that the extent of AM fungal root colonization was positively correlated with sapling height and light availability, which were related to the location of the sapling within the gap and the gap size. While colonization frequency by arbuscules in saplings on ash substrate was higher relative to saplings in mineral soil, the total AM fungal root colonization was similar between the substrates. A negative correlation between root colonization by Glomeromycota and non-AM fungal species indicated antagonistic interactions between different classes of root-associated fungi. Using DNA genotyping, we identified six AM fungal taxa representing genera Glomus and Ambispora present in Sequoiadendron roots. Overall, we found that AM fungal colonization of giant sequoia roots was associated with availability of plant-assimilated carbon to the fungus rather than with the AM fungal supply of mineral nutrients to the roots. We conclude that restoration practices affecting light availability and carbon assimilation alter feedbacks between sapling growth and activity of AM fungi in the roots.

  2. The sleeping giant: Reinforcement schedules

    PubMed Central

    Zeiler, Michael D.

    1984-01-01

    Schedule research has been the core of operant conditioning, but it is no longer an active area, at least with respect to its traditional focus of describing and explaining moment-to-moment behavior. Yet schedules are central in psychology: Not only do they establish lawful behavior, but they also play a major role in determining the effects of other variables. The reason for the decline appears to be primarily theoretical, in that the work seems not to have led to meaningful integration. The search for controlling variables brought into play by schedule specification has proven unsuccessful, and a catalog of all possible schedule effects is of limited interest. The paper reviews the reasons for the contemporary state of affairs. One prediction about future developments is that instead of revealing component variables and their modes of interaction, schedule effects will be treated as basic empirical laws. Theory will take the form of abstract statements that integrate these separate laws by reference to higher-order principles rather than by reduction to supposedly simpler component variables. PMID:16812403

  3. Giant cell tumour of bone in the denosumab era.

    PubMed

    van der Heijden, Lizz; Dijkstra, P D Sander; Blay, Jean-Yves; Gelderblom, Hans

    2017-03-30

    Giant cell tumour of bone (GCTB) is an intermediate locally aggressive primary bone tumour, occurring mostly at the meta-epiphysis of long bones. Overexpression of receptor activator of nuclear factor kappa-B ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated osteoclast-like giant cells, causing lacunar bone resorption. Preferential treatment is curettage with local adjuvants such as phenol, alcohol or liquid nitrogen. The remaining cavity may be filled with bone graft or polymethylmethacrylate (PMMA) bone cement; benefits of the latter are a lower risk of recurrence, possibility of direct weight bearing and early radiographic detection of recurrences. Reported recurrence rates are comparable for the different local adjuvants (27-31%). Factors increasing the local recurrence risk include soft tissue extension and anatomically difficult localisations such as the sacrum. When joint salvage is impossible, en-bloc resection and endoprosthetic joint replacement may be performed. Local tumour control on the one hand and maintenance of a functional native joint and quality of life on the other hand are the main pillars of surgical treatment for this disease. Current knowledge and development in the fields of imaging, functional biology and systemic therapy are forcing us into a paradigm shift from a purely surgical approach towards a multidisciplinary approach. Systemic therapy with denosumab (RANKL inhibitor) or zoledronic acid (bisphosphonates) blocks, respectively inhibits, bone resorption by osteoclast-like giant cells. After use of zoledronic acid, stabilisation of local and metastatic disease has been reported, although the level of evidence is low. Denosumab is more extensively studied in two prospective trials, and appears effective for the optimisation of surgical treatment. Denosumab should be considered in the standard multidisciplinary treatment of advanced GCTB (e.g. cortical destruction, soft

  4. The lithium abundances of a large sample of red giants

    SciTech Connect

    Liu, Y. J.; Tan, K. F.; Wang, L.; Zhao, G.; Li, H. N.; Sato, Bun'ei; Takeda, Y. E-mail: gzhao@nao.cas.cn

    2014-04-20

    The lithium abundances for 378 G/K giants are derived with non-local thermodynamic equilibrium correction considered. Among these are 23 stars that host planetary systems. The lithium abundance is investigated, as a function of metallicity, effective temperature, and rotational velocity, as well as the impact of a giant planet on G/K giants. The results show that the lithium abundance is a function of metallicity and effective temperature. The lithium abundance has no correlation with rotational velocity at v sin i < 10 km s{sup –1}. Giants with planets present lower lithium abundance and slow rotational velocity (v sin i < 4 km s{sup –1}). Our sample includes three Li-rich G/K giants, 36 Li-normal stars, and 339 Li-depleted stars. The fraction of Li-rich stars in this sample agrees with the general rate of less than 1% in the literature, and the stars that show normal amounts of Li are supposed to possess the same abundance at the current interstellar medium. For the Li-depleted giants, Li-deficiency may have already taken place at the main sequence stage for many intermediate mass (1.5-5 M {sub ☉}) G/K giants. Finally, we present the lithium abundance and kinematic parameters for an enlarged sample of 565 giants using a compilation of the literature, and confirm that the lithium abundance is a function of metallicity and effective temperature. With the enlarged sample, we investigate the differences between the lithium abundance in thin-/thick-disk giants, which indicate that the lithium abundance in thick-disk giants is more depleted than that in thin-disk giants.

  5. Constructing stable 3D hydrodynamical models of giant stars

    NASA Astrophysics Data System (ADS)

    Ohlmann, Sebastian T.; Röpke, Friedrich K.; Pakmor, Rüdiger; Springel, Volker

    2017-02-01

    Hydrodynamical simulations of stellar interactions require stable models of stars as initial conditions. Such initial models, however, are difficult to construct for giant stars because of the wide range in spatial scales of the hydrostatic equilibrium and in dynamical timescales between the core and the envelope of the giant. They are needed for, e.g., modeling the common envelope phase where a giant envelope encompasses both the giant core and a companion star. Here, we present a new method of approximating and reconstructing giant profiles from a stellar evolution code to produce stable models for multi-dimensional hydrodynamical simulations. We determine typical stellar stratification profiles with the one-dimensional stellar evolution code mesa. After an appropriate mapping, hydrodynamical simulations are conducted using the moving-mesh code arepo. The giant profiles are approximated by replacing the core of the giant with a point mass and by constructing a suitable continuation of the profile to the center. Different reconstruction methods are tested that can specifically control the convective behaviour of the model. After mapping to a grid, a relaxation procedure that includes damping of spurious velocities yields stable models in three-dimensional hydrodynamical simulations. Initially convectively stable configurations lead to stable hydrodynamical models while for stratifications that are convectively unstable in the stellar evolution code, simulations recover the convective behaviour of the initial model and show large convective plumes with Mach numbers up to 0.8. Examples are shown for a 2 M⊙ red giant and a 0.67 M⊙ asymptotic giant branch star. A detailed analysis shows that the improved method reliably provides stable models of giant envelopes that can be used as initial conditions for subsequent hydrodynamical simulations of stellar interactions involving giant stars.

  6. Microhabitat and vegetation selection by giant gartersnakes associated with a restored marsh in California

    USGS Publications Warehouse

    Halstead, Brian J.; Valcarcel, Patricia; Wylie, Glenn D.; Coates, Peter S.; Casazza, Michael L.; Rosenberg, Daniel K.

    2016-01-01

    These data describe coarse habitat use, activity information, and differences between used and available microhabitats and vegetation types to provide information about the behavior and habitat relationships of adult female giant gartersnakes (Thamnophis gigas) associated with a restored marsh in the Sacramento Valley of California.These data support the following publication:Brian J. Halstead, Patricia Valcarcel, Glenn D. Wylie, Peter S. Coates, Michael L. Casazza, and Daniel K. Rosenberg (2016) Active Season Microhabitat and Vegetation Selection by Giant Gartersnakes Associated with a Restored Marsh in California. Journal of Fish and Wildlife Management: December 2016, Vol. 7, No. 2, pp. 397-407. http://dx.doi.org/10.3996/042016-JFWM-029

  7. Denosumab: a new treatment option for giant cell tumor of bone.

    PubMed

    Lewin, J; Thomas, D

    2013-11-01

    Giant cell tumor of bone (GCTB) is an osteolytic, usually benign neoplasm characterized by infiltration with osteoclast-like giant cells, and the osteoclast differentiation factor receptor activator of nuclear factor kappa-B ligand (RANKL) is heavily involved in its pathogenesis. Denosumab belongs to a new class of drugs that inhibit RANKL. Prior to denosumab, multimodality treatment in refractory, recurrent and metastatic GCTB has shown variable results. Recent phase II data have demonstrated denosumab's activity with regard to disease and symptom control, without significant adverse effects. On the basis of this data, the FDA approved denosumab for the treatment of patients whose GCTB is unresectable, or when surgery is likely to result in severe morbidity. Ongoing questions remain, including the optimal scheduling, patient selection, use in the adjuvant setting and long-term toxicity concerns.

  8. Some requirements for the future giant low frequency ground based radio telescopes

    NASA Astrophysics Data System (ADS)

    Konovalenko, A. A.; Falkovich, I. S.; Gridin, A. A.; Lecheux, A.; Rosolen, C.; Rucker, H.

    2003-04-01

    During last years the interest to the low frequency radio astronomy is growing considerably. The projects of space-borne and ground-based new generation giant radio telescope (i.e. LOFAR) are discussed actively. The largest existing low frequency systems, at first, UTR-2 and URAN Ukraine) and NDA (France) are useful for the probing of new astrophysical ideas as well as of new technical approaches and requirements including future giant radio telescopes and solar system radio astronomy purposes. The 30 elements array with active dipoles was created on UTR-2 observatory for the test of some principal requirements. The investigations of the array confirmed the sensitivity, frequency range, interference immunity and low cost what need for the future instruments.

  9. DO GIANT PLANETS SURVIVE TYPE II MIGRATION?

    SciTech Connect

    Hasegawa, Yasuhiro; Ida, Shigeru E-mail: ida@geo.titech.ac.jp

    2013-09-10

    Planetary migration is one of the most serious problems to systematically understand the observations of exoplanets. We clarify that the theoretically predicted type II, migration (like type I migration) is too fast, by developing detailed analytical arguments in which the timescale of type II migration is compared with the disk lifetime. In the disk-dominated regime, the type II migration timescale is characterized by a local viscous diffusion timescale, while the disk lifetime is characterized by a global diffusion timescale that is much longer than the local one. Even in the planet-dominated regime where the inertia of the planet mass reduces the migration speed, the timescale is still shorter than the disk lifetime except in the final disk evolution stage where the total disk mass decays below the planet mass. This suggests that most giant planets plunge into the central stars within the disk lifetime, and it contradicts the exoplanet observations that gas giants are piled up at r {approx}> 1 AU. We examine additional processes that may arise in protoplanetary disks: dead zones, photoevaporation of gas, and gas flow across a gap formed by a type II migrator. Although they make the type II migration timescale closer to the disk lifetime, we show that none of them can act as an effective barrier for rapid type II migration with the current knowledge of these processes. We point out that gas flow across a gap and the fraction of the flow accreted onto the planets are uncertain and they may have the potential to solve the problem. Much more detailed investigation for each process may be needed to explain the observed distribution of gas giants in extrasolar planetary systems.

  10. A Program To Detect and Characterize Extra-Solar Giant Planets

    NASA Technical Reports Server (NTRS)

    Noyes, Robert W.; Boyce, Joseph M. (Technical Monitor)

    2001-01-01

    This grant report highlights activity in the following areas: (1) Improvement in Precise Radial Velocity (PRV) analysis code; (2) Reanalysis of previous data; (3) Improvements to the AFOE (Advanced Fiber Optic Echelle) spectrograph; (4) Development of PRV capabilities for the Hectochelle; (5) Extra-solar planet studies; (6) Longer-term plans for the AFOE; (7) Completion and publication of the analysis of the transiting gas-giant planet HD 209458b.

  11. Autoimmune hemolytic anemia and giant cell hepatitis: Report of three infants.

    PubMed

    Ünal, Şule; Kuşkonmaz, Barış; Balamtekin, Necati; Baysoy, Gökhan; Aytaç Elmas, Selin; Orhan, Diclehan; Kale, Gülsev; Yüce, Aysel; Gürakan, Figen; Gümrük, Fatma; Çetin, Mualla

    2010-12-05

    Giant cell hepatitis associated with direct Coombs' test-positive hemolytic anemia is a rare condition of childhood and the pathogenesis remains unclear. An autoimmune activation and loss of self-tolerance in these patients may be the underlying pathology related to the response of some of the patients to immunosuppressive treatment. Herein, we report the clinical presentation and course of three consecutive patients with this rare condition. We conclude that serum ferritin at diagnosis may be used for prediction of the outcome.

  12. Giant fibroelastoma of the aortic valve.

    PubMed

    di Summa, Michele; Iezzi, Federica

    2013-01-01

    Fibroelastomas account for less than 10% of all cardiac tumours, representing the most common valvular and the second most common cardiac benign tumour, following myxomas. Fibroelastomas are histologically benign; they can result in life-threatening complications such as stroke, acute valvular dysfunction, embolism, ventricular fibrillation, and sudden death. Surgical resection should be offered to all patients who have symptoms and to asymptomatic patients who have pedunculated lesions or tumors larger than 1 cm in diameter. Valve-sparing excision produces good long-term results in most instances. We report our surgical experience of a giant fibroelastoma in the aortic valve.

  13. Giant magnetoresistance in organic spin valves

    SciTech Connect

    Sun, Da-Li; Yin, Lifeng; Sun, Chengjun; Guo, Hangwen; Gai, Zheng; Zhang, Xiaoguang; Ward, Thomas Z; Cheng, Zhaohua; Shen, Jian

    2010-01-01

    Interfacial diffusion between magnetic electrodes and organic spacer layers is a serious problem in the organic spintronics which complicates attempts to understand the spin-dependent transport mechanism and hurts the achievement of a desirably high magnetoresistance (MR). We deposit nanodots instead of atoms onto the organic layer using buffer layer assist growth. Spin valves using this method exhibit a sharper interface and a giant MR of up to {approx}300%. Analysis of the current-voltage characteristics indicates that the spin-dependent carrier injection correlates with the observed MR.

  14. Enhanced giant magnetoimpedance in heterogeneous nanobrush

    PubMed Central

    2012-01-01

    A highly sensitive and large working range giant magnetoimpedance (GMI) effect is found in the novel nanostructure: nanobrush. The nanostructure is composed of a soft magnetic nanofilm and a nanowire array, respectively fabricated by RF magnetron sputtering and electrochemical deposition. The optimal GMI ratio of nanobrush is promoted to more than 250%, higher than the pure FeNi film and some sandwich structures at low frequency. The design of this structure is based on the vortex distribution of magnetic moments in thin film, and it can be induced by the exchange coupling effect between the interfaces of nanobrush. PMID:22963551

  15. Giant Malignant Pheochromocytoma with Palpable Rib Metastases

    PubMed Central

    Gokce, Gokhan; Kilicli, Fatih; Elagoz, Sahande; Ayan, Semih; Gultekin, Emin Yener

    2014-01-01

    Pheochromocytoma is a rare and usually benign neuroendocrine neoplasm. Only 10% of all these tumors are malignant and there are no definitive histological or cytological criteria of malignancy. Single malignancy criteria are the presence of advanced locoregional disease or metastases. We report a case, with a giant retroperitoneal tumor having multiple metastases including palpable rib metastases, who was diagnosed as a malignant pheochromocytoma. The patient was treated with surgery. The literature was reviewed to evaluate tumor features and current diagnostic and therapeutic approaches for patients with metastatic or potentially malignant pheochromocytoma. PMID:25152826

  16. Enhanced giant magnetoimpedance in heterogeneous nanobrush

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Mu, Congpu; Luo, Caiqin; Dong, Juan; Liu, Qingfang; Wang, Jianbo

    2012-09-01

    A highly sensitive and large working range giant magnetoimpedance (GMI) effect is found in the novel nanostructure: nanobrush. The nanostructure is composed of a soft magnetic nanofilm and a nanowire array, respectively fabricated by RF magnetron sputtering and electrochemical deposition. The optimal GMI ratio of nanobrush is promoted to more than 250%, higher than the pure FeNi film and some sandwich structures at low frequency. The design of this structure is based on the vortex distribution of magnetic moments in thin film, and it can be induced by the exchange coupling effect between the interfaces of nanobrush.

  17. Enhanced giant magnetoimpedance in heterogeneous nanobrush.

    PubMed

    Zhang, Yi; Mu, Congpu; Luo, Caiqin; Dong, Juan; Liu, Qingfang; Wang, Jianbo

    2012-09-10

    A highly sensitive and large working range giant magnetoimpedance (GMI) effect is found in the novel nanostructure: nanobrush. The nanostructure is composed of a soft magnetic nanofilm and a nanowire array, respectively fabricated by RF magnetron sputtering and electrochemical deposition. The optimal GMI ratio of nanobrush is promoted to more than 250%, higher than the pure FeNi film and some sandwich structures at low frequency. The design of this structure is based on the vortex distribution of magnetic moments in thin film, and it can be induced by the exchange coupling effect between the interfaces of nanobrush.

  18. Dynamical Coupling of Pygmy and Giant Resonances

    NASA Astrophysics Data System (ADS)

    Bertulani, Carlos; Brady, Nathan; Aumann, Thomas; Thomas, James

    2016-03-01

    One of the effects overseen in studies of excitation of pygmy resonances is the fact that both pygmy and giant resonances are strongly coupled. This coupling leads to dynamical effects such as the modification of transition probabilities and and cross sections. We make an assessment of such effects by means of the relativistic coupled channels equations developed by our group. Supported by the U.S. NSF Grant No. 1415656 and the U.S. DOE Grant No. DE-FG02-08ER41533.

  19. Asymptomatic Giant Intraventricular Cysticercosis: A Case Report

    PubMed Central

    Wongjittraporn, Suwarat; Tongma, Chawat; Chung, Heath

    2016-01-01

    Neurocysticercosis is a growing health problem in the United States and worldwide. Diagnosis and treatment is challenging especially if the physician is not familiar with this condition. The World Health Organization (WHO) estimates that neurocysticercosis affects 50 million people worldwide, especially in developing countries and causes approximately 50,000 deaths annually.1 Neurocysticercosis is of emerging importance in the United States especially in Hawai‘i because of immigration from disease-endemic regions.2 We present a case of a young Chinese immigrant male who presented with impressive imaging studies of a giant intraventricular neurocysticercosis. This case emphasizes the importance of recognizing neurocysticercosis, especially in the immigrant population. PMID:27437162

  20. Giant nonreciprocity near exceptional-point degeneracies

    NASA Astrophysics Data System (ADS)

    Thomas, Roney; Li, Huanan; Ellis, F. M.; Kottos, Tsampikos

    2016-10-01

    We show that gyrotropic structures with balanced gain and loss that respect antilinear symmetries exhibit a giant nonreciprocity at the so-called exact phase where the eigenfrequencies of the isolated non-Hermitian setup are real. The effect occurs in a parameter domain near an exceptional- point (EP) degeneracy, where mode orthogonality collapses. The theoretical predictions are confirmed numerically in the microwave domain, where a nonreciprocal transport above 90 dB is demonstrated, and are further verified using lumped-circuitry modeling. The analysis allows us to speculate the universal nature of the phenomenon for any wave system where EP and gyrotropy can coexist.

  1. Giant Star Clusters Near Galactic Core

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A video sequence of still images goes deep into the Milky Way galaxy to the Arches Cluster. Hubble, penetrating through dust and clouds, peers into the core where two giant clusters shine more brightly than any other clusters in the galaxy. Footage shows the following still images: (1) wide view of Sagittarius constellation; (2) the Palomar Observatory's 2 micron all-sky survey; and (3) an image of the Arches Cluster taken with the Hubble Space Telescope NICMOS instrument. Dr. Don Figer of the Space Telescope Science Institute discusses the significance of the observations and relates his first reaction to the images.

  2. Giant oral lipoma: a rare entity*

    PubMed Central

    Ponce, José Burgos; Ferreira, Gustavo Zanna; Santos, Paulo Sérgio da Silva; Lara, Vanessa Soares

    2016-01-01

    Lipomas are very common benign slow-growing soft tissue neoplasms composed of mature adipose tissue mostly diagnosed in the fifth decade of life. These tumors rarely present in the oral cavity, representing less than approximately 5% of all benign mouth tumors. They are usually less than 2cm in size and etiology remains unclear. We report a young male patient presenting with a giant lipoma in the buccal mucosa. Histopathology revealed a large area of mature fat cells consistent with conventional lipoma and an area of the mucosal lining of the lesion suggestive of morsicatio buccarum. In the present article, we emphasize the clinicopathological features and differential diagnosis of the disease.

  3. Giant magnetoresistance in bilayer graphene nanoflakes

    NASA Astrophysics Data System (ADS)

    Farghadan, Rouhollah; Farekiyan, Marzieh

    2016-09-01

    Coherent spin transport through bilayer graphene (BLG) nanoflakes sandwiched between two electrodes made of single-layer zigzag graphene nanoribbon was investigated by means of Landauer-Buttiker formalism. Application of a magnetic field only on BLG structure as a channel produces a perfect spin polarization in a large energy region. Moreover, the conductance could be strongly modulated by magnetization of the zigzag edge of AB-stacked BLG, and the junction, entirely made of carbon, produces a giant magnetoresistance (GMR) up to 100%. Intestinally, GMR and spin polarization could be tuned by varying BLG width and length. Generally, MR in a AB-stacked BLG strongly increases (decreases) with length (width).

  4. Giant field enhancement in electromagnetic Helmholtz nanoantenna

    NASA Astrophysics Data System (ADS)

    Chevalier, Paul; Bouchon, Patrick; Greffet, Jean-Jacques; Pelouard, Jean-Luc; Haïdar, Riad; Pardo, Fabrice

    2014-11-01

    Inspired by the acoustic Helmholtz resonator, we propose a slit-box electromagnetic nanoantenna able to concentrate the energy of an incident beam into surfaces a thousand times smaller than with a classical lens. This design produces a giant electric field enhancement throughout the slit. The intensity enhancement reaches 104 in the visible range up to 108 in the THz range even with focused beams, thanks to an omnidirectional reception. These properties could target applications requiring extreme light concentration, such as surface-enhanced infrared absorption, nonlinear optics, and biophotonics.

  5. Giant velum interpositum meningioma in a child.

    PubMed

    Moiyadi, Aliasgar V; Shetty, Prakash

    2012-07-01

    Intraventricular meningiomas are rare, but are relatively more often seen in children. Large size at presentation often obscures anatomical details. A particular subset of such tumors arising from the velum interpositum pose a significant surgical challenge. Thorough preoperative imaging, especially with respect to the course of the deep venous structures, provides useful evidence as to the origin. Preservation of venous anatomy at surgery is vital. We describe a 3-year-old girl with a giant velum interpositum meningioma that was completely excised with excellent outcome. This is probably the youngest such case reported.

  6. Giant monopole strength in {sup 58}Ni

    SciTech Connect

    Lui, Y.-W.; Clark, H. L.; Youngblood, D. H.

    2000-06-01

    The strength distribution of the giant monopole resonance in {sup 58}Ni has been measured from E{sub x}=10 to 35 MeV using small-angle scattering of 240-MeV {alpha} particles. E0 strength corresponding to 74{sub -12}{sup +22}% of the E0 EWSR was found between E{sub x}=12.0 and 31.1 MeV with a centroid of 20.30{sub -0.14}{sup +1.69} MeV. (c) 2000 The American Physical Society.

  7. Spectropolarimetry of Giant stars: Probing the influence of magnetic field on evolved stars Spectropolarimetry of Giant stars: Probing the influence of magnetic field on evolved stars

    NASA Astrophysics Data System (ADS)

    da Costa, Jefferson; Castro, Matthieu; Petit, Pascal; do Nascimento, José-Dias, Jr.

    2015-08-01

    It is know that lithium is element easily destroyed in stellar interior, the existence of lithium rich stars means a great challenge in stellar evolution. In this context our observations ravels the serendipitous discovery of an unusually high lithium abundance star. This is a K0III HD 150050, which has strong deepening on lithium line (6707.8 Å) this means lithium abundance of 2.81 0.2 dex, therefore this star belong a rare group called super Li-Rich stars. A possible source of the non-standard episodes required to produce Li-rich stars were identified in magneto-thermohaline mixing accounted by models of extra-mixing induced by magnetic buoyancy. However to better understand this is necessary more observational data. In last three decades several studies has showed that late type red giant stars presents a remarkable modifications in these outer atmosphere layers when they become late type star in HR diagram. These changes are founded through X-ray, Ultraviolet, and Chromospheric activity analyses, and then we can establish the called “Dividing lines”. We made spectropalarimetric observations with ESPaDOnS@CFHT to achieve two main objectives: analyze the influence of magnetic field in the Li-rich giant stars, and understand how works the magnetic field in late type giants and supergiants across the “dividing line”.

  8. Evolutionary dynamics of giant viruses and their virophages.

    PubMed

    Wodarz, Dominik

    2013-07-01

    Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested.

  9. New Frontiers-Class Missions to the Ice Giants

    NASA Astrophysics Data System (ADS)

    Elder, C. M.; Bramson, A. M.; Blum, L. W.; Chilton, H. T.; Chopra, A.; Chu, C.; Das, A.; Davis, A.; Delgado, A.; Fulton, J.; Jozwiak, L.; Khayat, A.; Landis, M. E.; Molaro, J. L.; Slipski, M.; Valencia, S.; Watkins, J.; Young, C. L.; Budney, C. J.; Mitchell, K. L.

    2017-02-01

    Ice giants are the least understood class of planets in our solar system but the most commonly observed type of exoplanet. We identify the major hurdles to achieving an ice giant mission within the cost constraints of a New Frontiers-class mission.

  10. [Prevalence and clinicopathological characteristics of giant cell tumors].

    PubMed

    Estrada-Villaseñor, E G; Linares-González, L M; Delgado-Cedillo, E A; González-Guzmán, R; Rico-Martínez, G

    2015-01-01

    The frequency of giant cell tumors reported in the literature is very variable. Considering that our population has its own features, which distinguish it from the Anglo-Saxon and Asian populations, we think that both the frequency and the clinical characteristics of giant cell tumors in our population are different. The major aim of this paper was to determine the frequency and clinicopathological characteristics of giant cell tumors of the bone. A cross-sectional descriptive study was conducted of the cases diagnosed at our service as giant cell tumors of the bone from January to December 2013. The electronic clinical records, radiologic records and histologic slides from each case were reviewed. Giant cell tumors represented 17% of total bone tumors and 28% of benign tumors. Patients included 13 females and 18 males. The most frequent locations of giant cell tumors were: the proximal tibia, 9 cases (29%), and the distal femur, 6 cases (19%). Forty-five percent of giant cell tumors were associated with aneurysmal bone cyst (ABC) (14 cases) and one case (3%) was malignant. The frequency of giant cell tumors in this case series was intermediate, that is, higher than the one reported in Anglo-Saxon countries (usually low), but without reaching the frequency rates reported in Asian countries (high).

  11. The central giant cell granuloma in childhood: clinical case report.

    PubMed

    Loyola, Adriano Mota; Fernandes, Alexandre Vieira; Magalhaes, Aparecido Onorio; Moreira, Marilia Rodrigues

    2005-01-01

    This report reviews the literature involving the central giant cell granuloma. Diagnosis and treatment are presented. The article reports the case of central giant cell granuloma, affecting the anterior region maxillary of a child, whom a conservative treatment, with cryotherapy, helped the preservation of anterior permanent teeth germs.

  12. Shoot transcriptome of the Giant Reed, Arundo donax

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The giant reed, Arundo donax, is a perennial grass species that has become an invasive plant in many countries. Expansive stands of A. donax have significant negative impacts on available water resources and efforts are underway to identify biological control agents against this species. The giant r...

  13. Rare liver tumor: symptomatic giant von Meyenburg complex

    PubMed Central

    Singh, Yardesh; Cawich, Shamir O.; Ramjit, Chunilal; Naraynsingh, Vijay

    2016-01-01

    von Meyenburg complexes are hamartomas that arise from intra-hepatic bile ducts. Symptomatic lesions are uncommon and giant lesions are exceedingly rare. When encountered, they should be excised because there are reports of malignant change in large, symptomatic lesions. We report a case of a symptomatic giant von Meyenburg complex. PMID:28068648

  14. Forming giant-sized polymersomes using gel-assisted rehydration

    DOE PAGES

    Greene, Adrienne C.; Sasaki, Darryl Y.; Bachand, George D.

    2016-05-26

    Here, we present a protocol to rapidly form giant polymer vesicles (pGVs). Briefly, polymer solutions are dehydrated on dried agarose films adhered to coverslips. Rehydration of the polymer films results in rapid formation of pGVs. This method greatly advances the preparation of synthetic giant vesicles for direct applications in biomimetic studies.

  15. Forming giant-sized polymersomes using gel-assisted rehydration

    SciTech Connect

    Greene, Adrienne C.; Sasaki, Darryl Y.; Bachand, George D.

    2016-05-26

    Here, we present a protocol to rapidly form giant polymer vesicles (pGVs). Briefly, polymer solutions are dehydrated on dried agarose films adhered to coverslips. Rehydration of the polymer films results in rapid formation of pGVs. This method greatly advances the preparation of synthetic giant vesicles for direct applications in biomimetic studies.

  16. Photo series for quantifying fuels and assessing fire risk in giant sequoia groves. Forest Service general technical report

    SciTech Connect

    Weise, D.R.; Gelobter, A.; Haase, S.M.; Sackett, S.S.

    1997-03-01

    Fuels and stand inventory data are presented for giant sequoia by using 18 different photos located in giant sequoia/mixed conifer stands in the Sierra Nevada of California. Total fuel loading ranges from 7 to 72 tons/acre. The stands have been subjected to a variety of disturbances including timbers harvesting, wildfire, prescribed fire, and recreational use. Fire behavior predictions were made by using 10th, 50th, and 90th percentile weather conditions and the inventoried fuels information. The long-term visual impacts of the various management activities can also be partially assessed with this photo series.

  17. Denosumab-Treated Giant Cell Tumor of Bone Its Histologic Spectrum and Potential Diagnostic Pitfalls.

    PubMed

    Roitman, Pablo Daniel; Jauk, Federico; Farfalli, Germán Luis; Albergo, José Ignacio; Aponte-Tinao, Luis Alberto

    2017-02-21

    Giant cell tumor of bone (GCT) is a locally aggressive, rarely metastasizing primary bone neoplasm that occurs most frequently in the epiphysis of long bones of young adults. It is composed of round, oval or elongated mononuclear cells admixed with osteoclast-like giant cells that express receptor activator of nuclear factor- қB (RANK). The mononuclear stromal cells express RANK ligand (RANKL), a mediator of osteoclast activation. Denosumab, a monoclonal antibody that inhibits RANKL reducing tumor-associated bone lysis, has been used to treat selected cases of GCT. We reviewed the clinical records and histologic slides of 9 patients with GCT that had received denosumab therapy and were subsequently surgically treated. There were 5 males and 4 females, aged 20 to 66 (mean 36). Duration of treatment varied from 2,5 to 13months (mean 5,9). In all cases, different degrees of ossification, fibrosis, depletion of giant cells and proliferation of mononuclear cells were seen. With this combination of changes, denosumab-treated GCT may mimick other lesions such as fibrous dysplasia, juvenile ossifying fibroma, nonossifying fibroma and osteoblastoma. Less frequent but more relevant is the presence of cellular atypia or patterns of ossification that resemble an undifferentiated pleomorphic sarcoma, a conventional osteosarcoma or a low-grade central osteosarcoma. The presence of clinical and radiological response to denosumab along with the lack of high mitotic activity, atypical mitotic figures, extensive necrosis or a permeative pattern of growth, represent clues to achieve a correct diagnosis.

  18. Therapeutic Antibodies Targeting CSF1 Impede Macrophage Recruitment in a Xenograft Model of Tenosynovial Giant Cell Tumor

    PubMed Central

    Cheng, Hongwei; Clarkson, Paul W.; Gao, Dongxia; Pacheco, Marina; Wang, Yuzhuo; Nielsen, Torsten O.

    2010-01-01

    Tenosynovial giant cell tumor is a neoplastic disease of joints that can cause severe morbidity. Recurrences are common following local therapy, and no effective medical therapy currently exists. Recent work has demonstrated that all cases overexpress macrophage colony-stimulating factor (CSF1), usually as a consequence of an activating gene translocation, resulting in an influx of macrophages that form the bulk of the tumor. New anti-CSF1 drugs have been developed; however there are no preclinical models suitable for evaluation of drug benefits in this disease. In this paper, we describe a novel renal subcapsular xenograft model of tenosynovial giant cell tumor. Using this model, we demonstrate that an anti-CSF1 monoclonal antibody significantly inhibits host macrophage infiltration into this tumor. The results from this model support clinical trials of equivalent humanized agents and anti-CSF1R small molecule drugs in cases of tenosynovial giant cell tumor refractory to conventional local therapy. PMID:20981142

  19. First Measurement of the Giant Monopole and Quadrupole Resonances in a Short-Lived Nucleus: {sup 56}Ni

    SciTech Connect

    Monrozeau, C.; Khan, E.; Blumenfeld, Y.; Beaumel, D.; Ebran, J. P.; Frascaria, N.; Gupta, D.; Marechal, F.; Scarpaci, J-A.; Mittig, W.; Roussel-Chomaz, P.; Gelin, M.; Garg, U.; Gillibert, A.; Keeley, N.; Obertelli, A.

    2008-02-01

    The isoscalar giant monopole resonance (GMR) and giant quadrupole resonance (GQR) have been measured in the {sup 56}Ni unstable nucleus by inducing the {sup 56}Ni(d,d{sup '}) reaction at 50A MeV in the Maya active target at the GANIL facility. The GMR and GQR centroids are measured at 19.3{+-}0.5 MeV and 16.2{+-}0.5 MeV, respectively. The corresponding angular distributions are extracted from 3 deg. to 7 deg. A multipole decomposition analysis using distorted wave Born approximation with random phase approximation transition densities shows that both the GMR and the GQR exhaust a large fraction of the energy-weighted sum rule. The demonstration of this new method opens a broad range of giant resonance studies at intermediate-energy radioactive beam facilities.

  20. Peripheral giant cell granuloma: This enormity is a rarity.

    PubMed

    Rodrigues, Silvia Victor; Mitra, Dipika Kalyan; Pawar, Sudarshana Devendrasing; Vijayakar, Harshad Narayan

    2015-01-01

    Peripheral giant cell granuloma (PGCG) is an infrequent exophytic lesion of the oral cavity, also known as giant cell epulis, osteoclastoma, giant cell reparative granuloma, or giant cell hyperplasia. Lesions vary in appearance from smooth, regularly outlined masses to irregularly shaped, multilobulated protuberances with surface indentations. Ulcerations of the margin are occasionally seen. The lesions are painless, vary in size, and may cover several teeth. It normally presents as a purplish-red nodule consisting of multinucleated giant cells in the background of mononuclear stromal cells and extravasated red blood cells. This case report describes the unusual appearance of a PGCG extending from left maxillary interdental gingiva to palatal area in 32-year-old female patient.

  1. Metastatic giant basal cell carcinoma: a case report

    PubMed Central

    Bellahammou, Khadija; Lakhdissi, Asmaa; Akkar, Othman; Rais, Fadoua; Naoual, Benhmidou; Elghissassi, Ibrahim; M’rabti, Hind; Errihani, Hassan

    2016-01-01

    Basal cell carcinoma is the most common skin cancer, characterised by a slow growing behavior, metastasis are extremely rare, and it occurs in less than 0, 1% of all cases. Giant basal cell carcinoma is a rare form of basal cell carcinoma, more aggressive and defined as a tumor measuring more than 5 cm at its largest diameter. Only 1% of all basal cell carcinoma develops to a giant basal cell carcinoma, resulting of patient's negligence. Giant basal cell carcinoma is associated with higher potential of metastasis and even death, compared to ordinary basal cell carcinoma. We report a case of giant basal cell carcinoma metastaticin lung occurring in a 79 years old male patient, with a fatal evolution after one course of systemic chemotherapy. Giant basal cell carcinoma is a very rare entity, early detection of these tumors could prevent metastasis occurrence and improve the prognosis of this malignancy. PMID:27795755

  2. Metastatic giant basal cell carcinoma: a case report.

    PubMed

    Bellahammou, Khadija; Lakhdissi, Asmaa; Akkar, Othman; Rais, Fadoua; Naoual, Benhmidou; Elghissassi, Ibrahim; M'rabti, Hind; Errihani, Hassan

    2016-01-01

    Basal cell carcinoma is the most common skin cancer, characterised by a slow growing behavior, metastasis are extremely rare, and it occurs in less than 0, 1% of all cases. Giant basal cell carcinoma is a rare form of basal cell carcinoma, more aggressive and defined as a tumor measuring more than 5 cm at its largest diameter. Only 1% of all basal cell carcinoma develops to a giant basal cell carcinoma, resulting of patient's negligence. Giant basal cell carcinoma is associated with higher potential of metastasis and even death, compared to ordinary basal cell carcinoma. We report a case of giant basal cell carcinoma metastaticin lung occurring in a 79 years old male patient, with a fatal evolution after one course of systemic chemotherapy. Giant basal cell carcinoma is a very rare entity, early detection of these tumors could prevent metastasis occurrence and improve the prognosis of this malignancy.

  3. [Giant haemangioma of the liver: diagnosis and treatment].

    PubMed

    Hoekstra, Lisette T; Bieze, Matthanja; Erdogan, Deha; Roelofs, Joris J T H; Beuers, Ulrich H W; van Gulik, Thomas M

    2012-01-01

    A liver haemangioma is a benign, usually small tumour comprised of blood vessels, which is often discovered coincidentally; giant haemangiomas are defined as haemangiomas larger than 5 cm. The differential diagnosis includes other hypervascular tumours, such as hepatocellular adenoma, hepatocellular carcinoma, metastasis of a neuro-endocrine tumour or renal cell carcinoma.- The diagnosis is based on abdominal ultrasonography and can be confirmed by a CT or MR scan. A wait-and-see approach is justified in patients without symptoms or with minimal symptoms, even in the presence of a giant haemangioma. Surgical resection of a giant haemangioma is only necessary when the preoperative diagnosis is inconclusive, or when the haemangioma leads to mechanical symptoms or complications. Extirpation is the only effective form of treatment of the giant haemangioma; enucleation is preferred over partial liver resection. A known complication of a giant haemangioma is the occurrence of disseminated intravascular coagulation, the Kasabach-Merritt syndrome; intervention is then demanded.

  4. Shackleton's Antarctic Adventure: The Greatest Survival Story of All Time. Teacher's Guide To Accompany the Giant-Screen Film.

    ERIC Educational Resources Information Center

    Gibb, Reen

    This teacher's guide was developed to accompany the giant-screen film, "Shackleton's Antarctic Adventure". The activities featured use a multidisciplinary approach and target students ages 7 through 14. Teacher pages include background information and student pages include instructions and additional information for understanding the…

  5. Ultrabass Sounds of the Giant Star xi Hya

    NASA Astrophysics Data System (ADS)

    2002-05-01

    times larger. The new observations demonstrate that xi Hya oscillates with several periods of around 3 hours. xi Hya is now approaching the end of its life - it is about to expand its outer envelope and to become a "red giant star" . It is quite different from stars like the Sun, which are only halfway through their active life. xi Hya is considerably more massive than any other star in which solar-like oscillations have so far been detected. This observational feat allows to study for the first time with seismic techniques the interior of such a highly evolved star. It paves the way for similar studies of different types of stars. A new chapter of stellar astrophysics is now opening as asteroseismology establishes itself as an ingenious method that is able to revolutionise our detailed understanding of stellar interiors and the overall evolution of stars . PR Photo 13a/02 : Oscillation frequencies in the Giant Star xi Hya PR Photo 13b/02 : Non-radial oscillations of xi Hya (computer graphics) PR Audio Clip 01/02 : Listen to the sound of xi Hya (RealMedia and MP3) The difficult art of asteroseismology Helioseismology (seismology of the Sun) is based on measurements of the changing radial velocity of the solar upper atmospheric layers (the "surface") by means of the well-known Doppler effect, as this surface moves up and down during acoustic oscillations. The corresponding amplitudes are very small, with velocities of up to 15 - 20 cm/sec, and the typical period is around 5 minutes. Therefore the phenomenon was first known as the "five-minute oscillations". Intensity measurements have also been tried, but the noise level is larger than for velocity data due to the presence of "granulation" (moving cells of hot gas) on the solar surface. In the case of larger and brighter stars like the giant stars, the corresponding amplitudes and periods increase. For instance, theoretical predictions for the giant star xi Hya have indicated that velocity amplitudes of about 7 m/sec and

  6. The effect of banana (Musa acuminata) peels hot-water extract on the immunity and resistance of giant freshwater prawn, Macrobrachium rosenbergii via dietary administration for a long term: Activity and gene transcription.

    PubMed

    Rattanavichai, Wutti; Chen, Ying-Nan; Chang, Chin-Chyuan; Cheng, Winton

    2015-10-01

    The non-specific immune parameters, disease resistance and immune genes expressions in Macrobrachium rosenbergii were evaluated at 120 days of post feeding the diets containing the extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). Results showed that prawns fed with a diet containing BPE at the level of 1.0, 3.0 and 6.0 g kg(-1) for 120 days had a significantly higher survival rate (30.0%, 40.0% and 56.7%, respectively) than those fed with the control diet after challenge with Lactococcus garvieae for 144 h, and the respective relative survival percentages were 22.2%, 33.3%, and 51.9%, respectively. Dietary BPE supplementation at 3.0 and/or 6.0 g kg(-1) for 120 days showed a significant increase total haemocyte count (THC), granular cell (GC), superoxide dismutase (SOD) activity, phenoloxidase (PO) activity, transglutaminase (TG) activity, and phagocytic activity and clearance efficiency to L. garvieae infection, and meanwhile, the significant decrease in haemolymph clotting times and respiratory bursts (RBs) per haemocyte of prawns were revealed. Furthermore, the mRNA expressions of prophenoloxidase (proPO), lipopolysaccharide and β-1,3-glucan binding protein (LGBP), peroxinectin (PE), transglutaminase (TG), and crustin (CT) were significantly increased. We therefore recommend that BPE can be used as an immunomodulator for prawns through dietary administration at 6.0 g kg(-1) for a long term (over 120 days) to modify immune responses and genes expression following the enhanced resistance against pathogens.

  7. Management of a giant perineal condylomata acuminata.

    PubMed

    Hemper, Evelyn; Wittau, Mathias; Lemke, Johannes; Kornmann, Marko; Henne-Bruns, Doris

    2016-01-01

    A condylomata acuminata infection is caused by human papillomaviridae (HPV). This sexually transmitted condition most often affects the perineal region. Importantly, infections with types 16 and 18 are associated with an increased risk for anal and cervix cancer. In most cases topical therapy is sufficient for successfully treating condylomata acuminata. Here, we report the case of a 51-year old patient who suffered from a giant perianal located condylomata acuminata which had developed over a period of more than 10 years. Imaging by MRI revealed a possible infiltration of the musculus sphincter ani externus. Because a topical treatment or a radiotherapy was considered unfeasible, a surgical treatment was the only therapeutic option in this unusual case. First, a colostomy was performed and subsequently a resection of the tumor in toto with circular resection of the external portion of the musculus sphincter ani externus was performed. The large skin defect was closed by two gluteus flaps. The rectum wall was reinserted in the remnant of the musculus sphincter ani externus. Postoperatively, parts of the flaps developed necrosis. Therefore, a vacuum sealing therapy was initiated. Subsequently, the remaining skin defects were closed by autologous skin transplantation. Six months later the colostomy could be reversed. To date, one year after first surgery, the patient has still a normal sphincter function and no recurrence of the condylomata acuminata. This case report demonstrates how giant condylomata acuminata can be successfully treated by extended surgical procedures including colostomy and plastic reconstruction of resulting defects upon resection.

  8. [Giant viruses: update, enigmas, controversies and perspectives].

    PubMed

    Claverie, Jean-Michel; Abergel, Chantal

    2016-12-01

    Unlike microbes known in his time, the first virus (that of tobacco mosaic disease) was discovered by Ivanoski in 1892 because it was not retained by Chamberland's porcelain candles. For more than a century afterward, viruses were equated with this simple property that is still extensively used today (using modern 0,2 µm pore filters) as a practical criterion to delineate the "viral fraction" from other microbes in medical or environmental samples. The first documented exception to the simplistic criterion of particle size came with the discovery of Mimivirus, the viral nature of which was eventually recognized in 2003, following ten years during which it was mistaken for an obligate intracellular bacterium. Thirteen more years later, we now realize that non-filtering "giant viruses" are not rare, probably ubiquitous, and come in a large variety of virion shapes, genome sizes, gene contents, and replication strategies. Following a quick description of the 4 giant virus families known today, we discuss the enigmas, controversies and perspectives of conceptual revolutions that are brought about by this new and booming area of virology.

  9. Giant magnetoresistance through a single molecule.

    PubMed

    Schmaus, Stefan; Bagrets, Alexei; Nahas, Yasmine; Yamada, Toyo K; Bork, Annika; Bowen, Martin; Beaurepaire, Eric; Evers, Ferdinand; Wulfhekel, Wulf

    2011-03-01

    Magnetoresistance is a change in the resistance of a material system caused by an applied magnetic field. Giant magnetoresistance occurs in structures containing ferromagnetic contacts separated by a metallic non-magnetic spacer, and is now the basis of read heads for hard drives and for new forms of random access memory. Using an insulator (for example, a molecular thin film) rather than a metal as the spacer gives rise to tunnelling magnetoresistance, which typically produces a larger change in resistance for a given magnetic field strength, but also yields higher resistances, which are a disadvantage for real device operation. Here, we demonstrate giant magnetoresistance across a single, non-magnetic hydrogen phthalocyanine molecule contacted by the ferromagnetic tip of a scanning tunnelling microscope. We measure the magnetoresistance to be 60% and the conductance to be 0.26G(0), where G(0) is the quantum of conductance. Theoretical analysis identifies spin-dependent hybridization of molecular and electrode orbitals as the cause of the large magnetoresistance.

  10. Giant renal artery aneurysm: A case report.

    PubMed

    Cindolo, Luca; Ingrosso, Manuela; De Francesco, Piergustavo; Castellan, Pietro; Berardinelli, Francesco; Fiore, Franco; Schips, Luigi

    2015-07-07

    A case of a 12 cm giant renal artery aneurysm (RAA) in an 59-year-old woman is reported. The patient was referred to our hospital for flank pain and spot hematuria. Ultrasonography (US) revealed some wide lacunar areas in her right kidney and a thin cortex. Three-dimensional computed tomography (3D-CT) revealed a giant right renal arteriovenous malformation (AVM). AngioCT scan showed a pervious right renal artery. The cavities of the right kidney were dilated and the parenchyma was markedly reduced. Two months later the patient underwent an open resection of the aneurysm and a right nephrectomy. She had an uneventful recovery and a healthy status (last follow-up: 9 month). In this particular case, a safe approach is the transabdominal approach since the aneurysm was very large, friable, and located on the right side. This report confirms the opportunity of a planned nephrectomy once there is adequate renal reserve in the opposite kidney using a midline approach.

  11. Giant intradiploic pseudomeningocele of occipital bone.

    PubMed

    Kumar, Rajinder; Chandra, Sarat P; Sharma, Bhawani Shanker

    2012-01-01

    The management of intradiploic CSF collection is controversial. Although it is a benign lesion, even then delay in diagnosis and treatment may lead to significant morbidity. The authors report a very rare case of giant posttraumatic intradiploic pseudomeningocele involving the occipital bone, occipital condyles, and clivus. The pathogenesis and management of intradiploic CSF collection are discussed. This 16-year-old boy presented with a history of enlarging swelling in the suboccipital region associated with headache, lower cranial nerve palsy, and features of high cervical compressive myelopathy. Investigations revealed a giant intradiploic lesion involving the occipital bone, condyles, and clivus associated with secondary basilar invagination, hydrocephalus, and syringomyelia. Intrathecal contrast administration did not reveal communication of intradiploic space with the subarachnoid space. A large occipital craniotomy was performed. A linear fracture and dural defect in the midline was identified, which was closed with fascial graft after removing the inner table of the skull. Cranioplasty was performed using the expanded calvarial bone. Ventriculoperitoneal shunt insertion was performed for hydrocephalus, and the patient improved remarkably. Posttraumatic intradiploic CSF collection, although a benign condition, may present with severe complications if treatment is delayed. Early diagnosis and treatment is essential. The authors suggest that this condition should be treated early, as for growing skull fractures.

  12. Giant cell reparative granuloma of the axis.

    PubMed

    Bayar, Mehmet Akif; Erdem, Yavuz; Gokcek, Cevdet; Koktekir, Ender; Kilic, Celal; Yasitli, Ugur; Tekiner, Ayhan

    2009-10-01

    Giant cell reparative granuloma (GCRG) is a rare, benign fibroosseous lesion. It typically arises in the mandible and maxilla, and less frequently in the skull bones. We report a case of GCRG of the axis, which is the first to be reported in the literature. A 35-year-old man was admitted to our clinic with the complaint of pain at his neck. There was no neurological deficit. CT and MRI showed a lesion destructing the body of the axis. Biopsy specimens were taken through the transoral-transpharyngeal route. Histopathological diagnosis was GCRG. The lesion was removed subtotally by the same route. We filled the tumor cavity with a bone graft and the patient was discharged with a halo brace without any neurological deficits. The follow-up CT revealed one year after the surgery showed sclerosis at the tumor site. The etiopathogenesis of GCRG is still controversial and the differential diagnosis, especially from giant cell tumor of bone is quite difficult. The treatment of choice for these lesions is complete surgical removal. Some authors recommend radiotherapy if total removal fails.

  13. Model of a Giant Impact on Saturn

    NASA Astrophysics Data System (ADS)

    Parisi, M. G.; Brunini, A.

    2002-09-01

    The stochastic processes at the end of the accretionary epoch have been long known (Safronov 1969). The large spin obliquity of Uranus (98o) is usually attributed to a great tangential collision with another protoplanet at the end of the accretion process (e.g., Korycansky et al. 1990, Parisi and Brunini 1997). Saturn may owe its obliquity (27o) to an impact by a very large protoplanet (Lissauer and Safronov 1991). If satellites had been orbiting around these planets before these large impacts had taken place, the impulse imparted at collision would have produced a shift in the orbital velocity of the satellites. Parisi and Brunini (1997) obtained that outer satellites of Uranus had been probably unbound. The discovery of the outer uranian moons (Gladman et al. 1998, 2000) set important constraints in this scenario. Physical conditions for Uranus, dynamical constraints and restrictions in the possible mechanisms for the origin of the outer uranian satellites were obtained from the knowledge of their actual orbital properties (Brunini et al. 2002). The richness of the irregular satellites systems is yielding valuable insights into the processes that occurred during the final stages of giant planet formation. We present here our first result of the modelling of a giant impact onto Saturn in connection with te recent discovery of a rich system of outer satellites of this planet (Gladman et al. 2001).

  14. Predecessors of the giant 1960 Chile earthquake

    USGS Publications Warehouse

    Cisternas, M.; Atwater, B.F.; Torrejon, F.; Sawai, Y.; Machuca, G.; Lagos, M.; Eipert, A.; Youlton, C.; Salgado, I.; Kamataki, T.; Shishikura, M.; Rajendran, C.P.; Malik, J.K.; Rizal, Y.; Husni, M.

    2005-01-01

    It is commonly thought that the longer the time since last earthquake, the larger the next earthquake's slip will be. But this logical predictor of earthquake size, unsuccessful for large earthquakes on a strike-slip fault, fails also with the giant 1960 Chile earthquake of magnitude 9.5 (ref. 3). Although the time since the preceding earthquake spanned 123 years (refs 4, 5), the estimated slip in 1960, which occurred on a fault between the Nazca and South American tectonic plates, equalled 250-350 years' worth of the plate motion. Thus the average interval between such giant earthquakes on this fault should span several centuries. Here we present evidence that such long intervals were indeed typical of the last two millennia. We use buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture. In these records, the 1960 earthquake ended a recurrence interval that had begun almost four centuries before, with an earthquake documented by Spanish conquistadors in 1575. Two later earthquakes, in 1737 and 1837, produced little if any subsidence or tsunami at the estuary and they therefore probably left the fault partly loaded with accumulated plate motion that the 1960 earthquake then expended. ?? 2005 Nature Publishing Group.

  15. Giant Baker's Cyst Associated with Rheumatoid Arthritis

    PubMed Central

    Bılgın, Emre; Ketencı, İsmail Emre; Ugurlar, Meriç

    2017-01-01

    We report a rare case of a “giant Baker's cyst-related rheumatoid arthritis (RA)” with 95 × 26 mm dimensions originating from the semimembranosus tendon. The patient presented with chronic pain and a palpable mass behind his left calf located between the posteriosuperior aspect of the popliteal fossa and the distal third of the calf. In MRI cystic lesion which was located in soft tissue at the posterior of gastrocnemius, extensive synovial pannus inside and degeneration of medial meniscus posterior horn were observed. Arthroscopic joint debridement and partial excision of the cyst via biomechanical valve excision were performed. The patient continued his follow-up visits at Rheumatology Department and there was no recurrence of cyst-related symptoms in 1-year follow-up. Similar cases were reported in the literature previously. However, as far as we know, a giant Baker's cyst-related RA, which was treated as described, has not yet been presented. PMID:28116197

  16. Predecessors of the giant 1960 Chile earthquake

    NASA Astrophysics Data System (ADS)

    Cisternas, Marco; Atwater, Brian F.; Torrejón, Fernando; Sawai, Yuki; Machuca, Gonzalo; Lagos, Marcelo; Eipert, Annaliese; Youlton, Cristián; Salgado, Ignacio; Kamataki, Takanobu; Shishikura, Masanobu; Rajendran, C. P.; Malik, Javed K.; Rizal, Yan; Husni, Muhammad

    2005-09-01

    It is commonly thought that the longer the time since last earthquake, the larger the next earthquake's slip will be. But this logical predictor of earthquake size, unsuccessful for large earthquakes on a strike-slip fault, fails also with the giant 1960 Chile earthquake of magnitude 9.5 (ref. 3). Although the time since the preceding earthquake spanned 123years (refs 4, 5), the estimated slip in 1960, which occurred on a fault between the Nazca and South American tectonic plates, equalled 250-350years' worth of the plate motion. Thus the average interval between such giant earthquakes on this fault should span several centuries. Here we present evidence that such long intervals were indeed typical of the last two millennia. We use buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture. In these records, the 1960 earthquake ended a recurrence interval that had begun almost four centuries before, with an earthquake documented by Spanish conquistadors in 1575. Two later earthquakes, in 1737 and 1837, produced little if any subsidence or tsunami at the estuary and they therefore probably left the fault partly loaded with accumulated plate motion that the 1960 earthquake then expended.

  17. Management of a giant perineal condylomata acuminata

    PubMed Central

    Hemper, Evelyn; Wittau, Mathias; Lemke, Johannes; Kornmann, Marko; Henne-Bruns, Doris

    2016-01-01

    A condylomata acuminata infection is caused by human papillomaviridae (HPV). This sexually transmitted condition most often affects the perineal region. Importantly, infections with types 16 and 18 are associated with an increased risk for anal and cervix cancer. In most cases topical therapy is sufficient for successfully treating condylomata acuminata. Here, we report the case of a 51-year old patient who suffered from a giant perianal located condylomata acuminata which had developed over a period of more than 10 years. Imaging by MRI revealed a possible infiltration of the musculus sphincter ani externus. Because a topical treatment or a radiotherapy was considered unfeasible, a surgical treatment was the only therapeutic option in this unusual case. First, a colostomy was performed and subsequently a resection of the tumor in toto with circular resection of the external portion of the musculus sphincter ani externus was performed. The large skin defect was closed by two gluteus flaps. The rectum wall was reinserted in the remnant of the musculus sphincter ani externus. Postoperatively, parts of the flaps developed necrosis. Therefore, a vacuum sealing therapy was initiated. Subsequently, the remaining skin defects were closed by autologous skin transplantation. Six months later the colostomy could be reversed. To date, one year after first surgery, the patient has still a normal sphincter function and no recurrence of the condylomata acuminata. This case report demonstrates how giant condylomata acuminata can be successfully treated by extended surgical procedures including colostomy and plastic reconstruction of resulting defects upon resection. PMID:26814336

  18. Giant Solitary Fibrous Tumor of Orbit.

    PubMed

    Tenekeci, Goktekin; Sari, Alper; Vayisoglu, Yusuf; Serin, Onur

    2015-07-01

    Solitary fibrous tumors (SFTs) have been reported in various locations in the body. Solitary fibrous tumors are extremely rare tumors, especially when located in the orbit. Diagnosis of SFT cannot be made based on histopathology only because it exhibits a variable microscopic appearance, and necessitates immunohistochemistry to confirm the diagnosis. A 51-year-old man was admitted to our clinic for the evaluation of a mass bulging in his left eye. Clinical examination revealed a painless mass extruding out of the orbital cavity with dimensions of 8 × 7  cm. Exenteration of the left eye including the upper and lower eyelid and reconstruction of the orbital cavity using a temporoparietal fascia flap and a temporal muscle flap was performed. SFT of orbital region is known as a slow growing and painless tumor. Based on previous studies, increased mitotic rate of the tumor gives the impression that the tumor has a malignant nature. Until now a small number or orbital SFTs were reported and none of them presented with a giant mass protruding out of the orbital cavity. We present a unique case of orbital SFT filling the whole orbital cavity and protruding outward as a giant mass. This case has been reported to expand our knowledge in this debated entity.

  19. Lessons from Mars on exploring for giants

    SciTech Connect

    Woidneck, R.K.; Mutschler, J.C.; Kasten, R.K. )

    1996-01-01

    Mars field, located in Mississippi Canyon blocks 763 and 807, stands out as the largest known field in the deep water Gulf of Mexico. Discovered in 1989, Mars is currently in the early stages of development. Understanding the geologic controls on this giant oil field provides insights which can be applied to exploration. Characteristics that distinguish Mars as a giant oil field are the large number of high quality reservoirs within an effective trapping configuration, and the highly efficient hydrocarbon migration pathway. Reservoir deposition was strongly influenced by shallow salt sheets, which focused deep marine sediment gravity flows. Trapping is predominantly stratigraphic, with reservoir limits controlled by basin geometry during deposition. Surrounding salt canopies served to focus, rather than impede, hydrocarbon migration into the Mars basin. Mars field geology typifies that of a broader play fairway, providing a framework for evaluating further prospectivity. The play fairway is characterized by Miocene to lower Pliocene deep marine reservoirs, primary salt withdrawal basins, thin salt canopies, and a low Pleistocene sedimentation rate. Experience at Mars demonstrates the importance of considering a range of possible reserve outcomes during prospect evaluation, and the value of high quality 3-D seismic data for reducing uncertainty.

  20. Lessons from Mars on exploring for giants

    SciTech Connect

    Woidneck, R.K.; Mutschler, J.C.; Kasten, R.K.

    1996-12-31

    Mars field, located in Mississippi Canyon blocks 763 and 807, stands out as the largest known field in the deep water Gulf of Mexico. Discovered in 1989, Mars is currently in the early stages of development. Understanding the geologic controls on this giant oil field provides insights which can be applied to exploration. Characteristics that distinguish Mars as a giant oil field are the large number of high quality reservoirs within an effective trapping configuration, and the highly efficient hydrocarbon migration pathway. Reservoir deposition was strongly influenced by shallow salt sheets, which focused deep marine sediment gravity flows. Trapping is predominantly stratigraphic, with reservoir limits controlled by basin geometry during deposition. Surrounding salt canopies served to focus, rather than impede, hydrocarbon migration into the Mars basin. Mars field geology typifies that of a broader play fairway, providing a framework for evaluating further prospectivity. The play fairway is characterized by Miocene to lower Pliocene deep marine reservoirs, primary salt withdrawal basins, thin salt canopies, and a low Pleistocene sedimentation rate. Experience at Mars demonstrates the importance of considering a range of possible reserve outcomes during prospect evaluation, and the value of high quality 3-D seismic data for reducing uncertainty.

  1. How to make a giant bubble

    NASA Astrophysics Data System (ADS)

    Burton, Justin; Frazier, Stephen

    2016-11-01

    Soap and water solutions can form massive, free floating films encompassing volumes in excess of 50 m3 with thicknesses of only 1-10 microns when mixed with polymeric additives. These films are interesting from a physical standpoint due to their long lifetime and stability in ambient environments. We have investigated a variety of mixtures which are deemed "optimal" for making large bubbles, such as solutions made from guar seeds and polyethylene oxide (PEO). Making a giant bubble requires a balance between viscous and elastic forces. Drawing out a large soap film requires a low-viscosity solution, while elasticity enhances stability. Using a combination of shear rheology, drop-based extensional rheology, and time-dependent thickness measurements, we found that "optimal" solutions showed similar extensional properties even though their shear viscosity differed by more than an order of magnitude. Soap and water solutions with polymers lived 2-3 times longer and drained more slowly than typical soap and water solutions, even though their initial thicknesses were similar. In addition, polymeric bubbles showed increased stability to aging in dry environments. By varying the molecular weight and concentration of PEO in the solutions, we are able to optimize the lifetime of the film and determine the best way to make a giant bubble.

  2. On the Final Mass of Giant Planets

    NASA Technical Reports Server (NTRS)

    Estrada, P. R.; Mosqueira, I.

    2004-01-01

    In the core accretion model of giant planet formation, when the core reaches critical mass, hydrostatic equilibrium is no longer possible and gas accretion ensues. If the envelope is radiative, the critical core mass is nearly independent of the boundary conditions and is roughly M(sub crit) 10Mass of the Earth (with weak dependence on the rate of planetesimal accretion M(sub core) and the disk opacity k). Given that such a core may form at the present location of Jupiter in a time comparable to its Type I migration time (10(exp 5) - 10(exp 6) years) provided that the nebula was significantly enhanced in solids with respect to the MMSN and stall at this location in a weakly turbulent (alpha approximately less than 10(exp -4) disk, it may be appropriate to assume that such objects inevitably form and drive the evolution of late-phase T Tauri star disks. Here we investigate the final masses of giant planets in disks with one or more than one such cores. Although the presence of several planets would lead to Type II migration (due to the effective viscosity resulting from the planetary tidal torques), we ignore this complication for now and simply assume that each core has stalled at its location in the disk. Once a core has achieved critical mass, its gaseous accretion is governed by the given Kelvin-Helmholtz timescale.

  3. Molecular genetic analysis of giant cell glioblastomas.

    PubMed Central

    Meyer-Puttlitz, B.; Hayashi, Y.; Waha, A.; Rollbrocker, B.; Boström, J.; Wiestler, O. D.; Louis, D. N.; Reifenberger, G.; von Deimling, A.

    1997-01-01

    Glioblastomas (GBMs) are a heterogeneous group of tumors. Recently, distinct molecular genetic alterations have been linked to subgroups of patients with GBM. Giant cell (gc)GBMs are a rare variant of GBM characterized by a marked preponderance of multinucleated giant cells. Several reports have associated this entity with a more favorable prognosis than the majority of GBMs. To evaluate whether gcGBM may also represent a genetically defined subgroup of GBM, we analyzed a series of 19 gcGBMs for mutations in the TP53 gene for amplification of the EGFR and CDK4 genes and for homozygous deletions in the CDKN2A (p16/MTS1) gene. Seventeen of nineteen gcGBMs carried TP53 mutations whereas EGFR and CDK4 gene amplification was seen in only one tumor each and homozygous deletion of CDKN2A was not observed at all. The strikingly high incidence of TP53 mutations and the relative absence of other genetic alterations groups gcGBM together with a previously recognized molecular genetic variant of GBM (type 1 GBM). It is tempting to speculate that the better prognosis of gcGBM patients may result from the low incidence of EGFR amplification and CDKN2A deletion, changes known for their growth-promoting potential. Images Figure 1 PMID:9284834

  4. Core merging and stratification following giant impact

    NASA Astrophysics Data System (ADS)

    Landeau, Maylis; Olson, Peter; Deguen, Renaud; Hirsh, Benjamin H.

    2016-10-01

    A stratified layer below the core-mantle boundary has long been suspected on the basis of geomagnetic and seismic observations. It has been suggested that the outermost core has a stratified layer about 100 km thick that could be due to the diffusion of light elements. Recent seismological evidence, however, supports a layer exceeding 300 km in thickness of enigmatic origin. Here we show from turbulent mixing experiments that merging between projectile and planetary core following a giant impact can lead to a stratified layer at the top of the core. Scaling relationships between post-impact core structure and projectile properties suggest that merging between Earth's protocore and a projectile core that is enriched in light elements and 20 times less massive can produce the thick stratification inferred from seismic data. Our experiments favour Moon-forming impact scenarios involving a projectile smaller than the proto-Earth and suggest that entrainment of mantle silicates into the protocore led to metal-silicate equilibration under extreme pressure-temperature conditions. We conclude that the thick stratified layer detected at the top of Earth's core can be explained as a vestige of the Moon-forming giant impact during the late stages of planetary accretion.

  5. Giant waves in weakly crossing sea states

    SciTech Connect

    Ruban, V. P.

    2010-03-15

    The formation of rogue waves in sea states with two close spectral maxima near the wave vectors k{sub 0} {+-} {Delta}k/2 in the Fourier plane is studied through numerical simulations using a completely nonlinear model for long-crested surface waves [24]. Depending on the angle {theta} between the vectors k{sub 0} and {Delta}k, which specifies a typical orientation of the interference stripes in the physical plane, the emerging extreme waves have a different spatial structure. If {theta} {<=} arctan(1/{radical}2), then typical giant waves are relatively long fragments of essentially two-dimensional ridges separated by wide valleys and composed of alternating oblique crests and troughs. For nearly perpendicular vectors k{sub 0} and {Delta}k, the interference minima develop into coherent structures similar to the dark solitons of the defocusing nonlinear Schroedinger equation and a two-dimensional killer wave looks much like a one-dimensional giant wave bounded in the transverse direction by two such dark solitons.

  6. Usefulness of immunosuppression for giant cell myocarditis.

    PubMed

    Cooper, Leslie T; Hare, Joshua M; Tazelaar, Henry D; Edwards, William D; Starling, Randall C; Deng, Mario C; Menon, Santosh; Mullen, G Martin; Jaski, Brian; Bailey, Kent R; Cunningham, Madeleine W; Dec, G William

    2008-12-01

    Giant cell myocarditis (GCM) is a rare and highly lethal disorder. The only multicenter case series with treatment data lacked cardiac function assessments and had a retrospective design. We conducted a prospective, multicenter study of immunosuppression including cyclosporine and steroids for acute, microscopically-confirmed GCM. From June 1999 to June 2005 in a standard protocol, 11 subjects received high dose steroids and cyclosporine, and 9 subjects received muromonab-CD3. In these, 7 of 11 were women, the mean age was 60 +/- 15 years, and the mean time from symptom onset to presentation was 27 +/- 33 days. During 1 year of treatment, 1 subject died of respiratory complications on day 178, and 2 subjects received heart transplantations on days 2 and 27, respectively. Serial endomyocardial biopsies revealed that after 4 weeks of treatment the degree of necrosis, cellular inflammation, and giant cells decreased (p = 0.001). One patient who completed the trial subsequently died of a fatal GCM recurrence after withdrawal of immunosuppression. Her case demonstrates for the first time that there is a risk of recurrent, sometimes fatal, GCM after cessation of immunosuppression. In conclusion, this prospective study of immunosuppression for GCM confirms retrospective case reports that such therapy improves long-term survival. Additionally, withdrawal of immunosuppression can be associated with fatal GCM recurrence.

  7. Literature review of giant gartersnake (Thamnophis gigas) biology and conservation

    USGS Publications Warehouse

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2015-08-03

    This report reviews the available literature on giant gartersnakes (Thamnophis gigas) to compile existing information on this species and identify knowledge gaps that, if addressed, would help to inform conservation efforts for giant gartersnakes.  Giant gartersnakes comprise a species of semi-aquatic snake precinctive to wetlands in the Central Valley of California.  The diversion of surface water and conversion of wetlands to agricultural and other land uses resulted in the loss of more than 90 percent of natural giant gartersnake habitats.  Because of this habitat loss, giant gartersnakes are now listed by the United States and California Endangered Species Acts as Threatened.  Most extant populations occur in the rice-growing regions of the Sacramento Valley, which comprises the northern portion of the giant gartersnake’s former range.  The huge demand for water in California for agriculture, industry, recreation, and other human consumption, combined with periodic severe drought, places remaining giant gartersnake habitats at increased risk of degradation and loss.  This literature review summarizes the available information on giant gartersnake distribution, habitat relations, behavior, demography, and other aspects of its biology relevant to conservation.  This information is then compiled into a graphical conceptual model that indicates the importance of different aspects of giant gartersnake biology for maintaining positive population growth, and identifies those areas for which important information relevant for conservation is lacking.  Directing research efforts toward these aspects of giant gartersnake ecology will likely result in improvements to conserving this unique species while meeting the high demands for water in California.

  8. Gas giants in hot water: inhibiting giant planet formation and planet habitability in dense star clusters through cosmic time

    NASA Astrophysics Data System (ADS)

    Thompson, Todd A.

    2013-05-01

    I show that the temperature of nuclear star clusters, starburst clusters in M82, compact high-z galaxies and some globular clusters of the Galaxy likely exceeded the ice-line temperature (TIce ≈ 150-170 K) during formation for a time comparable to the planet formation time-scale. The protoplanetary discs within these systems will thus, not have an ice line, decreasing the total material available for building protoplanetary embryos, inhibiting the formation of gas- and ice-giants if they form by core accretion, and prohibiting habitability. Planet formation by gravitational instability is similarly suppressed because Toomre's Q > 1 in all but the most massive discs. I show that cluster irradiation can in many cases dominate the thermodynamics and structure of passive and active protoplanetary discs for semi-major axes larger than ˜1-5 au. I discuss these results in the context of the observed lack of planets in 47 Tuc. I predict that a similar search for planets in the globular cluster NGC 6366 ([Fe/H] = -0.82) should yield detections, whereas (counterintuitively) the relatively metal-rich globular clusters NGC 6440, 6441 and 6388 should be devoid of giant planets. The characteristic stellar surface density above which TIce is exceeded in star clusters is ˜ 6 × 103 M⊙ pc- 2 f- 1/2dg, MW, where fdg, MW is the dust-to-gas ratio of the embedding material, normalized to the Milky Way value. Simple estimates suggest that ˜5-50 per cent of the stars in the universe formed in an environment exceeding this surface density. Future microlensing planet searches that directly distinguish between the bulge and disc planet populations of the Galaxy and M31 can test these predictions. Caveats and uncertainties are detailed.

  9. Atmospheric models for post- giant impact planets

    NASA Astrophysics Data System (ADS)

    Lupu, R.; Zahnle, K. J.; Marley, M. S.; Schaefer, L. K.; Fegley, B.; Morley, C.; Cahoy, K.; Freedman, R. S.; Fortney, J. J.

    2013-12-01

    The final assembly of terrestrial planets is now universally thought to have occurred through a series of giant impacts, such as Earth's own Moon-forming impact. These collisions take place over a time interval of about 100 million years, during which time it takes at least 10 collisions between planets to make a Venus or an Earth. In the aftermath of one of these collisions the surviving planet is hot, and can remain hot for millions of years. During this phase of accretion, the proto-terrestrial planet may have a dense steam atmosphere, that will affect both the cooling of the planet and our ability to detect it. Here we explore the atmospheric chemistry, photochemistry, and spectral signatures of post-giant-impact terrestrial planets enveloped by thick atmospheres consisting of vaporized rock material. The atmospheric chemistry is computed self-consistently for atmospheres in equilibrium with hot surfaces, with compositions reflecting either the bulk silicate Earth (BSE, which includes the crust, mantle, atmosphere and oceans) or Earth's continental crust (CC). These two cases allow us to examine differences in atmospheres formed by outgassing of silica-rich (felsic) rocks - like the Earth's continental crust - and MgO- and FeO-rich (mafic) rocks - like the BSE. Studies of detrital zircons from Jack Hills, Australia, show that the continental crust existed 164 million years after the formation of the solar system, in which case the material vaporized in a giant impact should likely reflect the CC composition. However, if at the time of impact the surface of the planet does not yet exhibit the formation of continents, then the BSE case becomes relevant. We compute atmospheric profiles for surface temperatures ranging from 1000 to 2200 K, surface pressures of 10 and 100 bar, and surface gravities of 10 and 30 m/s^2. We account for all major molecular and atomic opacity sources, including collision-induced absorption, to derive the atmospheric structure and compute

  10. Giant Oyster Mushroom Pleurotus giganteus (Agaricomycetes) Enhances Adipocyte Differentiation and Glucose Uptake via Activation of PPARγ and Glucose Transporters 1 and 4 in 3T3-L1 Cells.

    PubMed

    Paravamsivam, Puvaneswari; Heng, Chua Kek; Malek, Sri Nurestri Abdul; Sabaratnam, Vikineswary; M, Ravishankar Ram; Kuppusamy, Umah Rani

    2016-01-01

    The edible mushroom Pleurotus giganteus was tested for its effect on adipocyte differentiation and glucose uptake activity in 3T3-L1 cells. The basidiocarps of P. giganteus were soaked in methanol to obtain a crude methanol extract and then fractionated to obtain an ethyl acetate extract. In this study, cell proliferation was measured using an MTT assay, lipid accumulation using an Oil Red O assay, and glucose uptake using a fluorescence glucose uptake assay. Gene expression was measured via real-time polymerase chain reaction analysis with TaqMan primer. Ethyl acetate extract significantly enhanced adipogenic differentiation and glucose uptake in 3T3-L1 adipocytes via the expression of sterol regulatory element-binding protein, peroxisome proliferator-activated receptor γ, and phos-phatidylinositol 3-kinase/Akt. Glucose uptake was facilitated by the highly expressed glucose transporters Glut1 and Glut4. Taken together, these results suggest that P. giganteus ethyl acetate extract has an insulin-sensitizing effect on adipocytes and has potential as an adjuvant for the management of type 2 diabetes.

  11. First-ever observations of a live giant squid in the wild.

    PubMed

    Kubodera, Tsunemi; Mori, Kyoichi

    2005-12-22

    The giant squid, Architeuthis, is renowned as the largest invertebrate in the world and has featured as an ominous sea monster in novels and movies. Considerable efforts to view this elusive creature in its deep-sea habitat have been singularly unsuccessful. Our digital camera and depth recorder system recently photographed an Architeuthis attacking bait at 900 m off Ogasawara Islands in the North Pacific. Here, we show the first wild images of a giant squid in its natural environment. Recovery of a severed tentacle confirmed both identification and scale of the squid (greater than 8 m). Architeuthis appears to be a much more active predator than previously suspected, using its elongate feeding tentacles to strike and tangle prey.

  12. First-ever observations of a live giant squid in the wild

    PubMed Central

    Kubodera, Tsunemi; Mori, Kyoichi

    2005-01-01

    The giant squid, Architeuthis, is renowned as the largest invertebrate in the world and has featured as an ominous sea monster in novels and movies. Considerable efforts to view this elusive creature in its deep-sea habitat have been singularly unsuccessful. Our digital camera and depth recorder system recently photographed an Architeuthis attacking bait at 900 m off Ogasawara Islands in the North Pacific. Here, we show the first wild images of a giant squid in its natural environment. Recovery of a severed tentacle confirmed both identification and scale of the squid (greater than 8 m). Architeuthis appears to be a much more active predator than previously suspected, using its elongate feeding tentacles to strike and tangle prey. PMID:16321779

  13. Coupling between atmospheric layers in gaseous giant planets due to lightning-generated electromagnetic pulses

    NASA Astrophysics Data System (ADS)

    Luque, A.; Dubrovin, D.; Gordillo-Vázquez, F. J.; Ebert, U.; Parra-Rojas, F. C.; Yair, Y.; Price, C.

    2014-10-01

    Atmospheric electricity has been detected in all gaseous giants of our solar system and is therefore likely present also in extrasolar planets. Building upon measurements from Saturn and Jupiter, we investigate how the electromagnetic pulse emitted by a lightning stroke affects upper layers of a gaseous giant. This effect is probably significantly stronger than that on Earth. We find that electrically active storms may create a localized but long-lasting layer of enhanced ionization of up to 103 cm-3 free electrons below the ionosphere, thus extending the ionosphere downward. We also estimate that the electromagnetic pulse transports 107 J to 1010 J toward the ionosphere. There emissions of light of up to 108 J would create a transient luminous event analogous to a terrestrial "elve."

  14. The response of benthic meiofauna to hydrothermal emissions in the Pontine Archipelago, Tyrrhenian Sea (central Mediterranean Basin)

    NASA Astrophysics Data System (ADS)

    Di Bella, Letizia; Ingrassia, Michela; Frezza, Virgilio; Chiocci, Francesco Latino; Martorelli, Eleonora

    2016-12-01

    Recent investigations highlighted the occurrence of a giant depression related to hydrothermal activity off the Pontine Archipelago (central Mediterranean Sea, Italy). The new record of a giant seeping depression (Zannone Giant Pockmark, ZGP) in shallow-water provides the opportunity to study fluid vent impact on meiobenthic communities. The micropaleontological analyses on living (Rose Bengal stained) and dead assemblages recorded inside and outside the Zannone Giant Pockmark, allow to highlight changes in the structure and composition of the foraminiferal community that suggest variations of fluid emissions in different sectors of the study area. Inside the ZGP, under the direct influence of venting activity, a very peculiar living foraminiferal assemblage is found. It consists of agglutinated species (Spiculosiphon oceana, Jaculella acuta, Deuterammina rotaliformis) never found or very rare in the Mediterranean Sea. On the contrary dead assemblage testifies the changes on foraminiferal assemblages under carbonate dissolution process. Outside the pockmark in the nearby area of ZGP, the integrated meiofaunal and geochemical data suggest a transitional condition between vent influenced sedimentation and the typical carbonate sedimentation recorded in the rest of the Pontine Archipelago. In particular a possible spread of the venting activity in the northern and southern sectors of the study area, towards the edge of the Zannone insular shelf, is inferred. The impact of fluid emissions on foraminiferal assemblages can be summarized in the following observations: reduced biodiversity, increase of agglutinated species with predominant siliceous component in the test structure, limited distribution of living specimens inside the sediment, disappearance of porcelaneous taxa and presence of carbonate loss tests. As the result, the venting activity is likely to be the main environmental driver on the meiofaunal distribution. We also report, at the emission sites in the

  15. Host genome integration and giant virus-induced reactivation of the virophage mavirus.

    PubMed

    Fischer, Matthias G; Hackl, Thomas

    2016-12-07

    Endogenous viral elements are increasingly found in eukaryotic genomes, yet little is known about their origins, dynamics, or function. Here we provide a compelling example of a DNA virus that readily integrates into a eukaryotic genome where it acts as an inducible antiviral defence system. We found that the virophage mavirus, a parasite of the giant Cafeteria roenbergensis virus (CroV), integrates at multiple sites within the nuclear genome of the marine protozoan Cafeteria roenbergensis. The endogenous mavirus is structurally and genetically similar to eukaryotic DNA transposons and endogenous viruses of the Maverick/Polinton family. Provirophage genes are not constitutively expressed, but are specifically activated by superinfection with CroV, which induces the production of infectious mavirus particles. Virophages can inhibit the replication of mimivirus-like giant viruses and an anti-viral protective effect of provirophages on their hosts has been hypothesized. We find that provirophage-carrying cells are not directly protected from CroV; however, lysis of these cells releases infectious mavirus particles that are then able to suppress CroV replication and enhance host survival during subsequent rounds of infection. The microbial host-parasite interaction described here involves an altruistic aspect and suggests that giant-virus-induced activation of provirophages might be ecologically relevant in natural protist populations.

  16. Disc Dynamics In The Early Universe: Instabilities, Giant Clumps, Feedback & Outflows

    NASA Astrophysics Data System (ADS)

    Bournaud, Frédéric

    2016-10-01

    Star-forming galaxies at high redshift (z=1-3) have irregular, clumpy morphologies. These are best explained by a violent, ubiquitous gravitational instability in gas-rich disks, causing fragmentation in giant clumps and other irregular features. The instability can rapidly redistribute the baryons within galaxies, by inward migration of the giant clumps and other rapid inflows of mass. The promotes the growth of central bulges and other galactic components, and models predict that the resulting properties may finely match those observed in today's Milky Way-like spirals. The instability-driven inflow may also feed the central black hole in a moderate but steady mode and drive a high fraction of active galaxies, promoting earlier supermassive black hole growth. At the same time, intense stellar feedback in the giant gas-rich clumps and from the active nucleus drive intense gas outflows that regulate the galaxy mass to realistic levels, but the outflows are largely decoupled from the dense gas phases, which continue to form stars continuously. Hence the high-redshift progenitors of massive galaxies evolve in a steady unstable state lasting a couple of Gyr during which they build their fondamental structural components before evolving secularly into modern, quasi-stable spiral disks and spheroids.

  17. Pathogenesis of giant cell arteritis: new insight into the implication of CD161+ T cells.

    PubMed

    Samson, M; Audia, S; Martin, L; Janikashvili, N; Bonnotte, B

    2013-01-01

    Giant cell arteritis (GCA) is a granulomatous large-vessel vasculitis that usually affects the aorta and/or its major branches, especially the branches of the carotid arteries. Histo-pathological lesions are observed in all layers of the artery leading to segmental and focal panarteritis with a polymorphic cell infiltrate that includes T cells, macrophages and multinucleated giant cells, a fragmented internal elastic lamina and intimal hyperplasia. The pathophysiology of GCA is complex and not fully understood. In this review, we discuss the immunological aspects of GCA pathogenesis with a particular emphasis on T cell responses. Upon dendritic cell activation in the adventitia, CD4 T cells co-expressing CD161 are recruited in the arterial wall and polarised into Th1 and Th17 cells that produce IFN-γ and IL-17, respectively. These cytokines activate macrophages, giant cells and vascular smooth muscle cells, thus inducing vascular remodelling which leads to the ischaemic manifestations of GCA. Macrophages infiltrating the adventitia produce IL-1β and IL-6, which are responsible for the general symptoms encountered in GCA.

  18. Magneto-thermally activated spin-state transition in La0.95Ca0.05CoO3: magnetically-tunable dipolar glass and giant magneto-electricity.

    PubMed

    Pandey, Suchita; Kumar, Jitender; Awasthi, A M

    2016-03-07

    The magneto-dielectric spectroscopy of La0.95Ca0.05CoO3 covering the crossover of spin states reveals the strong coupling of its spin and dipolar degrees of freedom. The signature of the spin-state transition at 30 K clearly manifests in the magnetization data at a 1 Tesla optimal field. Our Co L3,2-edge X-ray absorption spectrum on the doped specimen is consistent with its suppressed low-to-intermediate spin-state transition temperature at ∼30 K compared to ∼150 K, documented for pure LaCoO3. The dispersive activation step in the dielectric constant with the associated relaxation peak in imaginary permittivity characterize the allied influence of coexistent spin-states on the dielectric character. Dipolar relaxation in the low-spin regime below the transition temperature is partly segmental (Vogel-Fulcher-Tamman (VFT) kinetics) and features magnetic-field tunability, whereas in the low/intermediate-spin disordered state above ∼30 K, it is uncorrelated (Arrhenic kinetics) and almost impervious to the magnetic field H. Kinetics-switchover defines the dipolar-glass transition temperature Tg(H) (=27 K|0T), below which their magneto-thermally-activated cooperative relaxations freeze out by the VFT temperature T0(H) (=15 K|0T). An applied magnetic field facilitates thermal activation in toggling the low spins up into the intermediate states. Consequently, the downsized dipolar-glass segments in the low-spin state and the independent dipoles in the intermediate state exhibit accelerated dynamics. A critical 5 Tesla field collapses the entire relaxation kinetics into a single Arrhenic behaviour, signaling that the dipolar glass is completely devitrified under all higher fields. The magneto-electricity (ME) spanning sizeable thermo-spectral range registers diverse signatures here in kinetic, spectral, and field behaviors, in contrast to the static/perturbative ME observed close to the spin-ordering in typical multiferroics. Intrinsic magneto-dielectricity (50%) along

  19. Giants among larges: how gigantism impacts giant virus entry into amoebae.

    PubMed

    Rodrigues, Rodrigo Araújo Lima; Abrahão, Jônatas Santos; Drumond, Betânia Paiva; Kroon, Erna Geessien

    2016-06-01

    The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites.

  20. Abundances in Globular Cluster Red Giant Stars

    NASA Astrophysics Data System (ADS)

    Cavallo, R. M.

    1997-12-01

    Observations of globular cluster red giant branch (RGB) stars have shown star-to-star variations in the abundances of C, N, O, Na, Mg, and Al, contrary to predictions of standard stellar evolutionary theory. I have modeled the variations in the abundance profiles around the hydrogen-burning shell (H shell) of metal-poor red giant stars by combining four RGB stellar evolutionary sequences of different metallicities with a detailed nuclear reaction network. This approach has significant advantages over previous research: (1) it allows for the variation in the temperature and density around the H shell; (2) it follows the effects of the changing H-shell structure as the sequence evolves; (3) it accounts for the effect of the metallicity on the abundance profiles; (4) it allows the reaction rates to be varied so that their uncertainties may be explored. The results are in good qualitative agreement with the observations. All the models show a region above the H shell in which first C, then O, is depleted in the CN and ON nuclear burning cycles. Within the C-depleted region, the (12) C/(13) C ratio is reduced to its equilibrium value. Just above the O-depleted region, Na is enhanced from proton captures on (22) Ne. In brighter models, Na becomes greatly enhanced within the O-depleted region as the NeNa cycle converts (20) Ne into (23) Na before attaining equilibrium inside the H shell. The more metal-poor models also show Al being increased around the H shell, first from (25,26) Mg, then from (24) Mg in the MgAl cycle. Despite the diminution (24) Mg suffers in synthesizing Al, the models show its abundance is increased due to the NeNa-cycle breakout reaction, (23) Na(p,γ)(24) Mg. This latter result is at odds with observations that show (24) Mg is depleted in a sample of M 13 and NGC 6752 giants (Shetrone 1996, 1997).

  1. Zonal Jets on the Giant Planets

    NASA Astrophysics Data System (ADS)

    Showman, A. P.; Lian, Y.; Gierasch, P. J.

    2006-12-01

    The question of what causes the numerous east-west zonal jets on the giant planets has remained a mystery since high-resolution Pioneer and Voyager images were returned in the 1970s. A probable hypothesis is that small-scale turbulence undergoes an inverse energy cascade that reorganizes the energy into zonal jets, but whether this turbulence results from deep penetrative convection or shallow cloud-layer processes (e.g., thunderstorms) remains unknown. Here I provide a broad summary of this problem and proceed to describe several results on the effect of cloud-layer turbulence on the flow. I present 3D numerical simulations showing that cloud-layer thermal contrasts (resulting from sunlight or latent-heat variations in the upper troposphere) can drive numerous Jupiter-like zonal jets at the cloud level, in some cases including a superrotating equatorial jet resembling that on Jupiter. Furthermore, these simulations -- as well as linear, analytic calculations -- show that such shallow forcing can produce deep jets that extend far below the level of the forcing. This disproves the common assumption that jets produced by cloud-layer processes would be confined to these shallow layers. An implication is that, contrary to the claims of many publications, the winds measured by the Galileo probe to pressures of 22 bars might just as easily result from shallow forcing as from deep convective forcing. Detailed diagnostics show that the deep jets result from Coriolis accelerations acting on deep meridional circulations that are induced by the upper-level forcing. I also show that, under some conditions, vertical stretching of atmospheric columns can inhibit the standard jet-formation mechanism and lead to vortices instead of jets. Cloud-layer turbulence can also substantially modify pre-existing deep jets, leading to different jet patterns at the 1-bar cloud level than exist in the interior. On balance, these simulations support the idea that cloud-level forcing plays an

  2. Provirophages and transpovirons as the diverse mobilome of giant viruses.

    PubMed

    Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V; Raoult, Didier

    2012-10-30

    A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ~7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer.

  3. Provirophages and transpovirons as the diverse mobilome of giant viruses

    PubMed Central

    Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V.; Raoult, Didier

    2012-01-01

    A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ∼7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer. PMID:23071316

  4. Important population viability analysis parameters for giant pandas (Aliuropoda melanoleuca).

    PubMed

    Gong, Minghao; Song, Yanling; Yang, Zhisong; Lin, Chen

    2012-06-01

    Population viability analysis (PVA) is a tool to evaluate the risk of extinction for endangered species and aid conservation decision-making. The quality of PVA output is dependent on parameters related to population dynamics and life-history; however, it has been difficult to collect this information for the giant panda (Aliuropoda melanoleuca), a rare and endangered mammal native to China, confined to some 30 fragmented habitat patches. Since giant pandas are long-lived, mature late, have lower reproductive rates, and show little sexual dimorphism, obtaining data to perform adequate PVA has been difficult. Here, we develop a parameter sensitivity index by modeling the dynamics of six giant panda populations in the Minshan Mountains, in order to determine the parameters most influential to giant panda populations. Our data shows that the giant panda populations are most sensitive to changes in four female parameters: initial breeding age, reproductive rate, mortality rate between age 0 and 1, and mortality rate of adults. The parameter sensitivity index strongly correlated with initial population size, as smaller populations were more sensitive to changes in these four variables. This model suggests that demographic parameters of females have more influence on the results of PVA, indicating that females may play a more important role in giant panda population dynamics than males. Consequently, reintroduction of female individuals to a small giant panda population should be a high priority for conservation efforts. Our findings form a technical basis for the coming program of giant panda reintroduction, and inform which parameters are crucial to successfully and feasibly monitoring wild giant panda populations.

  5. The behaviour of giant clams (Bivalvia: Cardiidae: Tridacninae).

    PubMed

    Soo, Pamela; Todd, Peter A

    2014-01-01

    Giant clams, the largest living bivalves, live in close association with coral reefs throughout the Indo-Pacific. These iconic invertebrates perform numerous important ecological roles as well as serve as flagship species-drawing attention to the ongoing destruction of coral reefs and their associated biodiversity. To date, no review of giant clams has focussed on their behaviour, yet this component of their autecology is critical to their life history and hence conservation. Almost 100 articles published between 1865 and 2014 include behavioural observations, and these have been collated and synthesised into five sections: spawning, locomotion, feeding, anti-predation, and stress responses. Even though the exact cues for spawning in the wild have yet to be elucidated, giant clams appear to display diel and lunar periodicities in reproduction, and for some species, peak breeding seasons have been established. Perhaps surprisingly, giant clams have considerable mobility, ranging from swimming and gliding as larvae to crawling in juveniles and adults. Chemotaxis and geotaxis have been established, but giant clams are not phototactic. At least one species exhibits clumping behaviour, which may enhance physical stabilisation, facilitate reproduction, or provide protection from predators. Giant clams undergo several shifts in their mode of acquiring nutrition; starting with a lecithotrophic and planktotrophic diet as larvae, switching to pedal feeding after metamorphosis followed by the transition to a dual mode of filter feeding and phototrophy once symbiosis with zooxanthellae (Symbiodinium spp.) is established. Because of their shell weight and/or byssal attachment, adult giant clams are unable to escape rapidly from threats using locomotion. Instead, they exhibit a suite of visually mediated anti-predation behaviours that include sudden contraction of the mantle, valve adduction, and squirting of water. Knowledge on the behaviour of giant clams will benefit

  6. Ghost of habitat past: historic habitat affects the contemporary distribution of giant garter snakes in a modified landscape.

    USGS Publications Warehouse

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2014-01-01

    Historic habitat conditions can affect contemporary communities and populations, but most studies of historic habitat are based on the reduction in habitat extent or connectivity. Little is known about the effects of historic habitat on contemporary species distributions when historic habitat has been nearly completely removed, but species persist in a highly altered landscape. More than 93% of the historic wetlands in the Central Valley of California, USA, have been drained and converted to agricultural and other uses, but agricultural wetlands, such as rice and its supporting infrastructure of canals, allow some species to persist. Little is known about the distribution of giant garter snakes Thamnophis gigas, a rare aquatic snake species inhabiting this predominantly agricultural landscape, or the variables that affect where this species occurs. We used occupancy modeling to examine the distribution of giant garter snakes at the landscape scale in the Sacramento Valley (northern portion of the Central Valley) of California, with an emphasis on the relative strength of historic and contemporary variables (landscape-scale habitat, local microhabitat, vegetation composition and relative prey counts) for predicting giant garter snake occurrence. Proximity to historic marsh best explained variation in the probability of occurrence of giant garter snakes at the landscape scale, with greater probability of occurrence near historic marsh. We suspect that the importance of distance to historic marsh represents dispersal limitations of giant garter snakes. These results suggest that preserving and restoring areas near historic marsh, and minimizing activities that reduce the extent of marsh or marsh-like (e.g. rice agriculture, canal) habitats near historic marsh may be advantageous to giant garter snakes.

  7. Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal.

    PubMed

    Watson, Sue-Ann

    2015-01-01

    Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as 'Vulnerable' on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are 'solar-powered' animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2) (control ~400, mid ~650 and high ~950 μatm) and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1). Elevated CO2 projected for the end of this century (~650 and ~950 μatm) reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation) in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals.

  8. Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal

    PubMed Central

    Watson, Sue-Ann

    2015-01-01

    Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as ‘Vulnerable’ on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are ‘solar-powered’ animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2) (control ~400, mid ~650 and high ~950 μatm) and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1). Elevated CO2 projected for the end of this century (~650 and ~950 μatm) reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation) in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals. PMID:26083404

  9. Management of Giant Splenic Artery Aneurysm

    PubMed Central

    Akbulut, Sami; Otan, Emrah

    2015-01-01

    Abstract To provide an overview of the medical literature on giant splenic artery aneurysm (SAA). The PubMed, Medline, Google Scholar, and Google databases were searched using keywords to identify articles related to SAA. Keywords used were splenic artery aneurysm, giant splenic artery aneuryms, huge splenic artery aneurysm, splenic artery aneurysm rupture, and visceral artery aneurysm. SAAs with a diameter ≥5 cm are considered as giant and included in this study. The language of the publication was not a limitation criterion, and publications dated before January 15, 2015 were considered. The literature review included 69 papers (62 fulltext, 6 abstract, 1 nonavailable) on giant SAA. A sum of 78 patients (50 males, 28 females) involved in the study with an age range of 27–87 years (mean ± SD: 55.8 ± 14.0 years). Age range for male was 30–87 (mean ± SD: 57.5 ± 12.0 years) and for female was 27–84 (mean ± SD: 52.7 ± 16.6 years). Most frequent predisposing factors were acute or chronic pancreatitis, atherosclerosis, hypertension, and cirrhosis. Aneurysm dimensions were obtained for 77 patients with a range of 50–300 mm (mean ± SD: 97.1 ± 46.0 mm). Aneurysm dimension range for females was 50–210 mm (mean ± SD: 97.5 ± 40.2 mm) and for males was 50–300 mm (mean ± SD: 96.9 ± 48.9 mm). Intraperitoneal/retroperitoneal rupture was present in 15, among which with a lesion dimension range of 50–180 mm (mean ± SD; 100 ± 49.3 mm) which was range of 50–300 mm (mean ± SD: 96.3 ± 45.2 mm) in cases without rupture. Mortality for rupture patients was 33.3%. Other frequent complications were gastrosplenic fistula (n = 3), colosplenic fistula (n = 1), pancreatic fistula (n = 1), splenic arteriovenous fistula (n = 3), and portosplenic fistula (n = 1). Eight of the patients died in early postoperative period while 67 survived. Survival status of the

  10. Giant piezoelectricity of monolayer group IV monochalcogenides

    NASA Astrophysics Data System (ADS)

    Fei, Ruixiang; Li, Wenbin; Li, Ju; Yang, Li

    We predict enormous, anisotropic piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M =Sn or Ge, X =Se or S), including SnSe, SnS, GeSe, and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their piezoelectric coefficients are about one to two orders of magnitude larger than those of other 2D materials, such as MoS2 and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique ``puckered'' C2v symmetry and electronic structure of monolayer group IV monochalcogenides. Given the achieved experimental advances in the fabrication of monolayers, their flexible character, and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  11. Variable Red Giants--The MACHO View

    SciTech Connect

    Keller, S C; Cook, K H

    2003-01-03

    The authors present a study of the MACHO red variable population in the Large Magellanic Cloud. This study reveals six period-luminosity relations among the red variable population. Only two of these were known prior to MACHO. The results are consistent with Mira pulsation in the fundamental mode. A sequence comprising 26% of the red variable population can not be explained by pulsation. They propose a dust {kappa}-mechanism in the circumstellar environment is responsible for the long period variation of these objects. The luminosity function of the variables shows a sharp edge at the tip of the red giant branch (TRGB). This is the first clear indication of a population of variable stars within the immediate vicinity of the TRGB. The results indicate this population amounts to 8% of the RGB population near the TRGB.

  12. Giant natural fluctuation models and anthropogenic warming

    NASA Astrophysics Data System (ADS)

    Lovejoy, S.; Rio Amador, L.; Hébert, R.; Lima, I.

    2016-08-01

    Explanations for the industrial epoch warming are polarized around the hypotheses of anthropogenic warming (AW) and giant natural fluctuations (GNFs). While climate sceptics have systematically attacked AW, up until now they have only invoked GNFs. This has now changed with the publication by D. Keenan of a sample of 1000 series from stochastic processes purporting to emulate the global annual temperature since 1880. While Keenan's objective was to criticize the International Panel on Climate Change's trend uncertainty analysis (their assumption that residuals are only weakly correlated), for the first time it is possible to compare a stochastic GNF model with real data. Using Haar fluctuations, probability distributions, and other techniques of time series analysis, we show that his model has unrealistically strong low-frequency variability so that even mild extrapolations imply ice ages every ≈1000 years. Helped by statistics, the GNF model can easily be scientifically rejected.

  13. Saturn: A Giant Thrust into Space

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Saturn: A Giant Thrust into Space. The film provides an introduction and overview of the Saturn launch vehicle. It is designed with stages to drop off as fuel is spent. There may be two, three, or four stages, depending on the payload. The Saturn rocket will be used to send Apollo missions to the Moon and back. Guidance systems and booster engine rockets are based on proven mechanisms. Scale models are used to test the engines. Hardware, airframes, guidance systems, instrumentation, and the rockets are produced at sites throughout the country. The engines go to Marshall Space Flight Center for further tests. After partial assembly, the vehicle is shipped to Cape Canaveral in large pieces where it is assembled using specially built equipment and structures. Further trials are performed to assure successful launches. [Entire movie available on DVD from CASI as Doc ID 20070030961. Contact help@sti.nasa.gov

  14. [A case of giant obsolete hydrocele testis].

    PubMed

    Numa, H; Sakamoto, S; Itoh, H; Kusuyama, H; Hiraga, S; Okada, K

    1987-09-01

    A 58-year-old man visited the urological clinic in Prefectural Tohkamachi Hospital with complaint of swelling of bilateral scrotal contents. He had no history of fever, pain or difficulty of urination. Physical examination revealed a giant mass of adult-head size in right scrotum and left inguinal hernia of fist growth. Surgical extirpation of the right scrotal mass and left inguinal herniorrhaphy was performed and the mass was diagnosed as obsolete hydrocele testis and weighed 1,600 g. The excised hydrocele sac showed marked thickening and dark brown pus amounted to about 1,400 ml, which was negative in bacterial culture. Histological examination revealed partial deposits of cholesterol and calcification in tunica vaginalis with extremely atrophic testis and destructive spermatogenesis. The findings suggested the existence of long-term infection in hydrocele testis. The etiology and pathogenesis of this disease is discussed.

  15. Multidisciplinary approach to giant paratesticular liposarcoma

    PubMed Central

    Sopeña-Sutil, Raquel; Silan, Francesco; Butron-Vila, Maria Teresa; Guerrero-Ramos, Felix; Lagaron-Comba, Emilio; Passas-Martinez, Juan

    2016-01-01

    Primary paratesticular tumours are very rare and the spermatic cord (SCT) is the most frequent site of origin, with 20% of malignancy. Although liposarcoma is the most frequent histotype (46.6 %), less than 200 cases have been reported in the literature. We report the case of a 56-year-old man who presented a giant scrotal mass of 25 years of evolution and measuring 40 × 40 cm. It could be considered the greatest paratesticular liposarcoma described to date. Computed tomogaphy (CT) revealed mass features consistent with liposarcoma and the simultaneous presence of bilateral inguinal hernia with bladder involvement. A multidisciplinary approach was taken to remove the mass, solve the hernia, and provide functional results. PMID:27695588

  16. Giant lupus vulgaris: A rare presentation.

    PubMed

    Sacchidanand, S; Sharavana, S; Mallikarjun, M; Nataraja, H V

    2012-01-01

    Cutaneous tuberculosis continues to be an important public health problem even with the availability of highly effective anti-tuberculous drugs. It constitutes 0.1% of all cases of extrapulmonary tuberculosis. Lupus vulgaris is the most common form of cutaneous tuberculosis that occurs in previously sensitized individuals with a moderate degree of immunity against tubercle bacilli. The different types of lupus vulgaris include plaque, ulcerative, vegetative, papular and nodular, and tumor forms. A 40-year-old man presented with large multiple plaques over right upper limb, right side of chest and back, and right lower limb for the past 30 years. Histopathology showed numerous noncaseating granulomas with Langhan's type of giant cells. The Mantoux test showed strong positivity and there was excellent response to anti-tuberculous treatment. This case is being reported because of its extreme chronicity of 30 years duration, unusually large size and multiplicity of lesions.

  17. Giant vacuum forces via transmission lines

    PubMed Central

    Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon

    2014-01-01

    Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line. PMID:25002503

  18. Giant complex odontoma in maxillary sinus

    PubMed Central

    Carvalho Visioli, Adriano Rossini; de Oliveira e Silva, Cléverson; Marson, Fabiano Carlos; Takeshita, Wilton Mitsunari