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Sample records for cryogenian glaciation cap

  1. Cryogenian cap carbonates - what do laminar scale investigations reveal about formation?

    Science.gov (United States)

    Miller, N. R.; Maupin, C. R.; Partin, J. W.; Quinn, T.; Giddings, J.

    2009-12-01

    Mid- to Late-Neoproterozoic “Cryogenian” cap carbonates are generally regarded as marine chemical sediments rapidly deposited during climatic recoveries from some of Earth’s most extreme glacial intervals, but there is little consensus regarding formation. Many cap successions initiate abruptly above glacigenic strata as finely laminated carbonate (typically dolostone), even in otherwise siliciclastic dominated marine continua, suggesting water mass control and widespread deposition below storm wave base. Cap carbonate units often culminate intervals of ongoing negative δ13C, transitioning to positive δ13C in the higher succession. Considering that fine lamination is a common characteristic among many cap carbonate units in space and time, laminar scale chemostratigraphic investigations may offer insights to modes of formation. Toward this end, we integrate bedding-normal LA-ICP-MS scans and high-resolution C and O isotope stratigraphy, for an array of cap carbonate units spanning “Kaigas”, “Sturtian”, and “Marinoan” post-glacial intervals; namely: Assem Limestone, N. Ethiopia (Nubia); Beck Spring Dolomite and Noonday Dolomite, Death Valley Area (W. Laurentia); Scout Mountain Member of the Pocatello Formation, S. Idaho (W. Laurentia); Tindelpina Shale Member, S. Australia (Adelaide Geosyncline); Rasthof and Keilberg Formations, N. Namibia (Congo Craton); and Mirrasol O’est, Brazil (Sao Francisco Craton). Whole-rock assessments for basal cap samples have δ13C between -4.8 to -1.4‰ and δ18O between -15.5 to -3.1‰. Corresponding PASS-normalized REE patterns show moderate LREE depletion, minor MREE enrichment, and slight HREE depletion. Cap samples from the higher positive δ13C succession (Noonday/Rasthof) display flatter patterns. Laser ablation scans for the Rasthof Fm (basal rhythmite and middle sublittoral microbialite) and Noonday Dolomite show that lamina couplets consist of alternations of comparatively darker organic/terrigenous (Si

  2. Ancient glaciations and hydrocarbon accumulations in North Africa and the Middle East

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    Le Heron, Daniel Paul; Craig, Jonathan; Etienne, James L.

    2009-04-01

    At least six glaciations are purported to have affected North Africa and the Middle East region over the last one billion years, including two in the Cryogenian (Neoproterozoic), Hirnantian (Late Ordovician), Silurian, Carboniferous and Early Permian events. The sedimentary record associated with these glaciations, together with the intensity to which each has been investigated, is highly variable. As hydrocarbon exploration proceeds aggressively across the North Africa and Middle East regions, we review the relationship between glaciation and hydrocarbon accumulations. With the exception of Oman, and locally Egypt, which were tectonically active both during the Neoproterozoic and Early Palaeozoic all glaciations took place along an essentially stable passive continental margin. During the Neoproterozoic, two glaciations are recognised, referred to as older and younger Cryogenian glaciations respectively. Both of these Cryogenian events are preserved in Oman; only the younger Cryogenian has been reported in North Africa in Mauritania and Mali at the flanks of the Taoudenni Basin. The process of initial deglaciation in younger Cryogenian glaciations resulted in incision, at least locally producing large-bedrock palaeovalleys in Oman, and the deposition of glacial diamictites, gravels, sandstones and mudstones. As deglaciation progressed "cap carbonates" were deposited, passing vertically into shale with evidence for deposition in an anoxic environment. Hence, younger Cryogenian deglaciation may be associated with hydrocarbon source rock deposits. Hirnantian (Late Ordovician) glaciation was short lived (rock across the region. Existing models do not adequately explain the temporal and spatial development of anoxia, and hence of black shale/deglacial source rocks. The origins of a palaeotopography previously invoked as the primary driver for this anoxia is allied to a complex configuration of palaeo-ice stream pathways, "underfilled" tunnel valley incisions

  3. Cryogenian Snowball Earth: a 25th anniversary assessment of models and data

    Science.gov (United States)

    Hoffman, P. F.

    2014-12-01

    In 1989, Joe Kirschvink applied a nascent planetary climate theory—the self-reversing ice-albedo instability—to Neoproterozoic geology, citing paleomagnetic evidence that ancient Australian glaciers reached tidewater near the paleo-equator. He attributed the "snowball Earth" to a unique preponderance of low-latitude continents, and inferred that complex life including metazoa were spawned in the nutrient-rich glacial aftermath. There have been major advances in models and data since 1989, and gratifying convergences between them. In models, frozen oceans coexist with dynamic ice sheets, as demanded by geological data. Geochronological data show that snowball glaciations were prolonged and their terminations globally synchronous, as required by geochemical models for snowball deglaciation. In models, zonal average sources and sinks of water vapor are reversed in snowball atmospheres relative to climate states with ice lines (at low or high-latitude). Ice-covered oceans are well mixed, by true thermohaline meridional overturning and related jets, with implications for data linking iconic snowball iron-formations with silled basins. Triple oxygen isotope data from sulfate robustly supports model predictions of atmospheric CO2 required for snowball deglaciation, while promising results have been obtained from a variety of pH, weathering, productivity and redox sensitive proxies. The known first appearances of sponge biomarkers and metazoan embryos bracket the terminal Cryogenian snowball glaciation. Existing model-data conflicts are good targets for future research. Boron isotopes in syndeglacial cap dolomites consistently imply catastrophic ocean acidification upon deglaciation, while models suggest that the existence of cap dolomites implies that seawater acidified gradually and was buffered by the dissolution of carbonate, delivered by glaciers. Above all, the newly emerging Cryogenian chronology (highlighted in this session) presents new puzzles. Two low

  4. Stratigraphic architecture of the Cryogenian successions of South China

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    Zhu, M.; Yin, Z.; Zhang, J.; Condon, D. J.; Macdonald, F. A.; Liu, P.

    2014-12-01

    Stratigraphy and sedimentology of the Cryogenian glacial successions provide primary data for elucidating climatic change of this critical interval. The Cryogenian strata of South China were deposited in a rift basin, and exhibit dramatic facies change from the basin center to margin, which complicates stratigtraphic correlations. Here we present new sedimentological, geochemical and stratigraphic data based on the detailed analyses of more than ten well exposed sections along a basinward transect from north-south. In the basin center, Cryogenian strata are about 4000 m thick and characterized by two glaciogenic diamictite units separated by a diamictite-free siliciclastic interval. Initiation of the Chang'an glaciation (Sturtian equivalent) is conformable and gradational with dropstones appearing in siltstone at the basal part of the Chang'an Formation followed by a shoaling-up sequence that is interpreted to represent a glacio-eustatic sea-level fall. In the basin center, >600 m of graded beds of siliciclastic rocks and debrites of the Fulu Formation overlie the Chang'an Formation. The Fulu Formation is succeeded by a thin (factors of glacial dynamics and active tectonism into account, we develop a facies model to interpret the sedimentology and stratigraphic architecture of these successions. Combined with new geochronological data, our data will provide tests for Cryogenian climatic models.

  5. Snowball Earth climate dynamics and Cryogenian geology-geobiology.

    Science.gov (United States)

    Hoffman, Paul F; Abbot, Dorian S; Ashkenazy, Yosef; Benn, Douglas I; Brocks, Jochen J; Cohen, Phoebe A; Cox, Grant M; Creveling, Jessica R; Donnadieu, Yannick; Erwin, Douglas H; Fairchild, Ian J; Ferreira, David; Goodman, Jason C; Halverson, Galen P; Jansen, Malte F; Le Hir, Guillaume; Love, Gordon D; Macdonald, Francis A; Maloof, Adam C; Partin, Camille A; Ramstein, Gilles; Rose, Brian E J; Rose, Catherine V; Sadler, Peter M; Tziperman, Eli; Voigt, Aiko; Warren, Stephen G

    2017-11-01

    Geological evidence indicates that grounded ice sheets reached sea level at all latitudes during two long-lived Cryogenian (58 and ≥5 My) glaciations. Combined uranium-lead and rhenium-osmium dating suggests that the older (Sturtian) glacial onset and both terminations were globally synchronous. Geochemical data imply that CO 2 was 10 2 PAL (present atmospheric level) at the younger termination, consistent with a global ice cover. Sturtian glaciation followed breakup of a tropical supercontinent, and its onset coincided with the equatorial emplacement of a large igneous province. Modeling shows that the small thermal inertia of a globally frozen surface reverses the annual mean tropical atmospheric circulation, producing an equatorial desert and net snow and frost accumulation elsewhere. Oceanic ice thickens, forming a sea glacier that flows gravitationally toward the equator, sustained by the hydrologic cycle and by basal freezing and melting. Tropical ice sheets flow faster as CO 2 rises but lose mass and become sensitive to orbital changes. Equatorial dust accumulation engenders supraglacial oligotrophic meltwater ecosystems, favorable for cyanobacteria and certain eukaryotes. Meltwater flushing through cracks enables organic burial and submarine deposition of airborne volcanic ash. The subglacial ocean is turbulent and well mixed, in response to geothermal heating and heat loss through the ice cover, increasing with latitude. Terminal carbonate deposits, unique to Cryogenian glaciations, are products of intense weathering and ocean stratification. Whole-ocean warming and collapsing peripheral bulges allow marine coastal flooding to continue long after ice-sheet disappearance. The evolutionary legacy of Snowball Earth is perceptible in fossils and living organisms.

  6. Microfossils from cap dolomites of the Lower Vendian Churochnaya Formation in the Polyudov Range (North Urals): Paleoecological approach to interpretation of Late Proterozoic glaciations

    Science.gov (United States)

    Sergeev, V. N.; Chumakov, N. M.; Semikhatov, M. A.; Vorob'eva, N. G.

    2013-01-01

    Microfossils from silicified varieties of cap dolomites crowning the section of the tillite-bearing Lower Vendian (Ediacaran) Churochnaya Formation in the Polyudov Range (North Urals) are characterized. These microfossils are the first to be found from Vendian sections of the region and from all the terminal post-glacial sediments, one of the most significant global glaciation Marinoan of the African Glacial Era, when glaciers reached the equator. They are represented by remains of hormogonian and chrococcacean cyanobacteria as well as possible green filamentous algae. This microbiotic assemblage is of relatively low diversity, being composed of taxa with wide stratigraphic ranges characteristic of Proterozoic conservative microbiotas developed in shallow-water siliceous-carbonate facies. The lack of phytoplanktonic microfossils in this biota including Pertatataka-type acanthomorphic acritarchs or Ediacaran Complex Acanthomorph Palynoflora (ECAP) is also consistent with the conclusion on shallow-water deposition of the Churochnaya Formation. Moreover, most cyanobacteria representatives occurring in the latter are characteristic of shallow-water arid environments that confirm a theory of significant temperature increase during accumulation of the cap dolomites after termination of the above-mentioned glaciation. In addition to these microfossils, the cap dolomite member of the Churochnaya Formation contains filamentous and coccoidal pseudofossils formed under influence of post-sedimentary fluids. In their morphometric parameters, they resemble structures described from Archean sections as microfossil remains, which may be a key to interpreting their nature.

  7. Oxygenation of a Cryogenian ocean (Nanhua Basin, South China) revealed by pyrite Fe isotope compositions

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    Zhang, Feifei; Zhu, Xiangkun; Yan, Bin; Kendall, Brian; Peng, Xi; Li, Jin; Algeo, Thomas J.; Romaniello, Stephen

    2015-11-01

    The nature of ocean redox chemistry between the Cryogenian Sturtian and Marinoan glaciations (ca. 663-654 Ma) is important for understanding the relationship between environmental conditions and the subsequent emergence and expansion of early animals. The Cryogenian-to-Ediacaran stratigraphic succession of the Nanhua Basin in South China provides a nearly complete sedimentary record of the Cryogenian, including a continuous record of interglacial sedimentation. Here, we present a high-resolution pyrite Fe isotope record for a ∼120-m-long drill-core (ZK105) through Sturtian glacial diamictites and the overlying interglacial sediments in the Nanhua Basin to explore changes in marine chemistry during the late Cryogenian. Our pyrite Fe isotope profile exhibits significant stratigraphic variation: Interval I, comprising middle to upper Tiesi'ao diamictites (correlative with the Sturtian glaciation), is characterized by light, modern seawater-like Fe isotope compositions; Interval II, comprising uppermost Tiesi'ao diamictites and the basal organic-rich Datangpo Formation, is characterized by an abrupt shift to heavier Fe isotope compositions; and Interval III, comprising organic-poor grey shales in the middle Datangpo Formation, is characterized by the return of lighter, seawater-like Fe isotope compositions. We infer that Interval I pyrite was deposited in a predominantly anoxic glacial Nanhua Basin through reaction of dissolved Fe2+ and H2S mediated by microbial sulfate reduction (MSR). The shift to heavier pyrite Fe isotope values in Interval II is interpreted as partial oxidation of ferrous iron to ferric iron and subsequent near-quantitative reduction and transformation of Fe-oxyhydroxides to pyrite through coupling with oxidation of organic matter in the local diagenetic environment. In Interval III, near-quantitative oxidation of ferrous iron to Fe-oxyhydroxides followed by near-quantitative reduction and conversion to pyrite in the local diagenetic environment

  8. Baltica in the Cryogenian, 850-650 Ma

    OpenAIRE

    Pease, Victoria; Daly, J.S.; Elming, S-Å.; Kumpulainen, Risto; Moczydlowska, Malgorzata; Puchkov, V.; Roberts, D.; Saintot, A.; Stephenson, R.

    2008-01-01

    This new tectonic synthesis provides a framework for understanding the dynamic evolution of Baltica and for constraining tectonic correlations within the context of the Neoproterozoic break-up of Rodinia–Pannotia. Cryogenian Baltica is described with respect to five geographic regions: the northwest, northeast, east, south, and southwest (modern coordinates). These geographic regions define three principal Cryogenian tectonic margins: a rifting northwestern margin, a passive northeaste...

  9. The rise of algae in Cryogenian oceans and the emergence of animals

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    Brocks, Jochen J.; Jarrett, Amber J. M.; Sirantoine, Eva; Hallmann, Christian; Hoshino, Yosuke; Liyanage, Tharika

    2017-08-01

    The transition from dominant bacterial to eukaryotic marine primary productivity was one of the most profound ecological revolutions in the Earth’s history, reorganizing the distribution of carbon and nutrients in the water column and increasing energy flow to higher trophic levels. But the causes and geological timing of this transition, as well as possible links with rising atmospheric oxygen levels and the evolution of animals, remain obscure. Here we present a molecular fossil record of eukaryotic steroids demonstrating that bacteria were the only notable primary producers in the oceans before the Cryogenian period (720-635 million years ago). Increasing steroid diversity and abundance marks the rapid rise of marine planktonic algae (Archaeplastida) in the narrow time interval between the Sturtian and Marinoan ‘snowball Earth’ glaciations, 659-645 million years ago. We propose that the incumbency of cyanobacteria was broken by a surge of nutrients supplied by the Sturtian deglaciation. The ‘Rise of Algae’ created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.

  10. The rise of algae in Cryogenian oceans and the emergence of animals.

    Science.gov (United States)

    Brocks, Jochen J; Jarrett, Amber J M; Sirantoine, Eva; Hallmann, Christian; Hoshino, Yosuke; Liyanage, Tharika

    2017-08-31

    The transition from dominant bacterial to eukaryotic marine primary productivity was one of the most profound ecological revolutions in the Earth's history, reorganizing the distribution of carbon and nutrients in the water column and increasing energy flow to higher trophic levels. But the causes and geological timing of this transition, as well as possible links with rising atmospheric oxygen levels and the evolution of animals, remain obscure. Here we present a molecular fossil record of eukaryotic steroids demonstrating that bacteria were the only notable primary producers in the oceans before the Cryogenian period (720-635 million years ago). Increasing steroid diversity and abundance marks the rapid rise of marine planktonic algae (Archaeplastida) in the narrow time interval between the Sturtian and Marinoan 'snowball Earth' glaciations, 659-645 million years ago. We propose that the incumbency of cyanobacteria was broken by a surge of nutrients supplied by the Sturtian deglaciation. The 'Rise of Algae' created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.

  11. Microbial mat structures in the basal Ediacaran Doushantuo cap dolostone from the Yangtze Gorges area of South China and their environmental implications

    Science.gov (United States)

    Wang, Z.; Wang, J.; Xiao, S.; Hu, J.

    2014-12-01

    Environmental changes after the terminal Cryogenian snowball Earth event have been debated extensively in the literature. But there have been relatively few studies on the biotic response in the aftermath of this snowball Earth event. In fact, a variety of potential microbial facies are preserved in basal Ediacaran cap dolostones as peloids, clotted fabrics, and morphologically diverse microbialites (e. g., tube-like stromatolites and stratiform biolaminites). In South China, centimeter-sized domal and conical stromatolites consisting of wavy or wrinkled microbial mats occur at the top of the Doushantuo cap dolostone. Sedimentological investigation of these stromatolites on outcrop and in core samples from the Yangtze Gorges area suggests that they are likely biological in origin. These stromatolites are characterized by vertical accumulation of dark and light laminae. The dark laminae are sub-millimetric in thickness and are composed of probably biogenic kerogen as determined by Raman spectroscopy. The dark laminae is also rich in pyrite, likely derived from organic degradation by sulfate reduction bacteria. Microsparry calcite occur as cements between the dark laminae. Within the Doushantuo stromatolites, there are patches of randomly oriented calcite needles. The precipitation of these calcite needles may have also been facilitated by microbial processes such bacterial sulfate reduction. Our study shows that shallow marine environment became habitable soon after the snowball Earth glaciation ended and benthic microbes were among some of the first organisms to colonize these environments.

  12. Geochemistry and Isotope Stratigraphy (C, O, Sr, Nd, Cr) of the Ediacaran Sete Lagoas Cap Carbonate, Bambui Group, Brazil: Insights into Earth's Oceanic and Atmosphere Geochemical Cycles After a Snowball Glaciation.

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    Caxito, F.; Frei, R.; Uhlein, G. J.; Uhlein, A.

    2016-12-01

    We studied a basal Ediacaran cap carbonate profile pertaining to the base of the Bambuí Group (Sete Lagoas Formation) in the central portion of the São Francisco basin, east central Brazil. The section begins with a two-meter thick pink dolostone which grades upward into a reddish limestone. The basal dolostone preserves a drop of δ13C values from -3.8 to -4.2‰, and δ18O values from -4.5 to -5.1‰. The red laminated limestone yielded δ13C values averaging -5‰ for about 60 m up section. Above 60 m, the δ13C values shift abruptly to around -0.5‰. The section is capped by black calcarenites with positive δ13C (+0.9‰); these high [Sr] carbonates (>1000 ppm) yield 87Sr/86Sr around 0.7076. Overall, there is an upwards-decreasing trend of ɛNd(630 Ma) values, from -6.0 in the base to -7.2 towards the top, and also upwards-decreasing trends of trace metal concentrations, especially for Cr (10-4 ppm), Sc (4.3-1.7 ppm), Co (3.7-0.8 ppm), Cu (4-0.3 ppm), Zn (29-0.6 ppm), and Ti (80-10 ppm). δ53Cr values of the basal pink cap dolostone are about -0.3‰, with an upwards-increasing trend to about +0.2‰ at the topmost carbonates. Thus, the cap carbonate is characterized by upwards-decreasing trends of ɛNd(630 Ma) and trace metal concentrations and upwards-increasing trends of δ13C, δ18O and δ53Cr. These fluctuations can be interpreted to reflect increased continentally-derived input into the shallow seawater. The higher ɛNd(630 Ma) and trace metal contents, as well as negative δ13C and δ53Cr of the basal cap dolostone all point to a higher contribution of less-fractionated sources to seawater geochemical composition, probably due to the fact that oceanic geochemical cycles were not yet fully restored after isolation by ice caps from atmospheric and continental weathering inputs. Upwards, in the limestone section, decreasing ɛNd(630 Ma), increasing δ13C and increasingly positively fractionated δ53Cr values suggest a recovery of Earth

  13. Late Pleistocene glaciation of the Mt Giluwe volcano, Papua New Guinea

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    Barrows, T.T.; Hope, G.S.; Prentice, M.L.; Fifield, L.K.; Tims, S.G.

    2011-01-01

    The Mt Giluwe shield volcano was the largest area glaciated in Papua New Guinea during the Pleistocene. Despite minimal cooling of the sea surface during the last glacial maximum, glaciers reached elevations as low as 3200 m. To investigate changes in the extent of ice through time we have re-mapped evidence for glaciation on the southwest flank of Mt Giluwe. We find that an ice cap has formed on the flanks of the mountain on at least three, and probably four, separate occasions. To constrain the ages of these glaciations we present 39 new cosmogenic 36Cl exposure ages complemented by new radiocarbon dates. Direct dating of the moraines identifies that the maximum extent of glaciation on the mountain was not during the last glacial maximum as previously thought. In conjunction with existing potassium/argon and radiocarbon dating, we recognise four distinct glacial periods between 293-306 ka (Gogon Glaciation), 136-158 ka (Mengane Glaciation), centred at 62 ka (Komia Glaciation) and from >20.3-11.5 ka (Tongo Glaciation). The temperature difference relative to the present during the Tongo Glaciation is likely to be of the order of at least 5 ??C which is a minimum difference for the previous glaciations. During the Tongo Glaciation, ice was briefly at its maximum for less than 1000 years, but stayed near maximum levels for nearly 4000 years, until about 15.4 ka. Over the next 4000 years there was more rapid retreat with ice free conditions by the early Holocene. ?? 2011 Elsevier Ltd.

  14. Future glaciation in Fennoscandia

    International Nuclear Information System (INIS)

    Forsstroem, L.

    1999-09-01

    Cyclic growing and melting of great ice sheets in the Northern Hemisphere is typical for the Quaternary Period, and it is likely that this cycle will continue in the future. This report discusses the principal processes predicted to occur during the future glaciation which are likely to be of importance for a nuclear waste repository. It is a revised version of a synthesis of the results of two state-of-the art reports, working meetings and a seminar. Based on present knowledge, two alternative trends (A and B) can be presented for fluctuations in climate in Fennoscandia. According to forecast A the climate will gradually become colder, permitting the growth of glaciers in the mountainous areas of Norway and Sweden after 5000 years. After a minor warmer period, a greater ice advance will cover a large part of Finland around 20 000 years from now. After a new minor interstade, the ice will advance again, so that c. 60 000 years from now the Stockholm-Helsinki region will be covered by thick ice. The ice sheet will melt partially at 70 000 years AP, but then it will grow to its maximum around 100 000 years AP and cover the whole Baltic basin. Almost complete melting of the ice sheet will take place during the next interglaciation c. 120 coo years AP. According to forecast B the growth of the ice sheet will not begin for another 50 000 years, and Finland will be covered by ice about 60 000 years from now. After a minor melting, the ice sheet will enlarge and cover almost the whole Baltic basin 100 000 years from now. During the following ice minimum, at 120 000 years AP, the ice sheet will still cover northern Finland. At 150 000 years it will cover the whole Baltic basin, but then it will melt almost completely by 165 000 years from now, during the following interglaciation. In both forecasts the main changes caused by the ice sheet will be downwarping/uplift of the crust and changes in sea level. In addition, changes in the groundwater head and flux are foreseen

  15. Cyclostratigraphic constraints on the duration of the Datangpo Formation and the onset age of the Nantuo (Marinoan) glaciation in South China

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    Bao, Xiujuan; Zhang, Shihong; Jiang, Ganqing; Wu, Huaichun; Li, Haiyan; Wang, Xinqiang; An, Zhengze; Yang, Tianshui

    2018-02-01

    Constructing an accurate timeline is critical for reconstructing the Earth systems through critical transitions in climate, geochemistry, and life. Existing dates constrain synchronous initiation (ca. 717 Ma) and termination (ca. 660 Ma) of the Sturtian glaciation from multiple continents. The termination of the younger Marinoan glaciation is also well dated at ca. 635 Ma, but the onset of this glaciation is only roughly constrained as ≤ ca. 654 Ma (South China) and ≥ ca. 639 Ma (Namibia). To test if the Marinoan glaciation started close to ca. 654 Ma or ca. 639 Ma, we have conducted a cyclostratigraphic study on the Cryogenian non-glacial Datangpo Formation that conformably overlies and underlies Sturtian and Marinoan glacial diamictites, respectively, in a deep-water basin section in South China. A total of 28,765 magnetic susceptibility (MS) measurements from a drillcore of the 292-m-thick, muddy siltstone- and shale-dominated Datangpo Formation are used for cyclostratigraphic analysis. The results reveal significant decameter- to meter-scale sedimentary cycles of 16-12 m, 3.6-3.0 m, 1.0-0.8 m, and 0.6-0.4 m. The ratios of these cycle wavelengths match well with those of the Milankovitch cycles calibrated for the Cryogenian Period. The established astrochronologic time scale suggests that the duration of the Datangpo Formation is about 9.8 million years. Together with the radiometric age of ca. 660 Ma for the termination of the Sturtian glaciation, the cyclostratigraphic data suggest that the Nantuo (Marinoan) glaciation in South China initiated at ca. 650 Ma, which is slightly younger than but consistent with the ca. 654 Ma U-Pb age from the top of the Datangpo Formation in shelf sections. This age, however, is significantly older than the ages obtained from Marinoan-age glacial diamictites in South China (ca. 636 Ma) and Namibia (ca. 639 Ma). Given that most of the shelf sections may have suffered from glacial erosion, obtaining the onset age of the

  16. The Location and Styles of Ice-Free “Oases” during Neoproterozoic Glaciations with Evolutionary Implications

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    Daniel Paul Le Heron

    2012-05-01

    Full Text Available Evidence based on molecular clocks, together with molecular evidence/biomarkers and putative body fossils, points to major evolutionary events prior to and during the intense Cryogenian and Ediacaran glaciations. The glaciations themselves were of global extent. Sedimentological evidence, including hummocky cross-stratification (representing ice-free seas affected by intra-glacial storms, dropstone textures, microbial mat-bearing ironstones, ladderback ripples, and wave ripples, militates against a “hard” Snowball Earth event. Each piece of sedimentological evidence potentially allows insight into the shape and location, with respect to the shoreline, of ice-free areas (“oases” that may be viewed as potential refugia. The location of such oases must be seen in the context of global paleogeography, and it is emphasized that continental reconstructions at 600 Ma (about 35 millions years after the “Marinoan” ice age are non-unique solutions. Specifically, whether continents such as greater India, Australia/East Antarctica, Kalahari, South and North China, and Siberia, were welded to a southern supercontinent or not, has implications for island speciation, faunal exchange, and the development of endemism.

  17. Past glaciation in the tropics

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    Hastenrath, Stefan

    2009-05-01

    Tropical glaciers are considered along three meridional profiles, for the Australasian sector, Africa and the Americas. Evaluated are the annual mean freezing level 0 °C, modern equilibrium line altitude MEL, and past equilibrium line altitude PEL. The calculation of 0 °C is based on a 1958-1997 global data set; MEL refers to estimates concerning the first half of the 20th century; and the timing of the PEL is not generally known. 0 °C stands around 4000-5000 m, with lower levels in the outer tropics. MEL is reached in the Australasian sector on four mountains, and in Africa on three mountains, near the Equator, near or above 0 °C. In the American cordilleras many peaks are still glaciated, above 0 °C, but in the arid southern tropical Andes even summits above 6000 m do not reach MEL. The PEL stands between 3000 m and 5000 m, high in the equatorial zone, but highest in the arid southern tropical Andes. The height difference between MEL and PEL is of order 1000 m, with regional differences. Deglaciation dates range between 15,000 and 8000 years BP, with later timing towards the higher elevations. This synopsis suggests priority targets for further research: morphological mapping and age determination in the High Atlas of Morocco; timing of deglaciation in the High Semyen of Ethiopia and the Altos de Cuchumatanes of Guatemala; exploration in the highlands of Lesotho and of the Dominican Republic; and glaciation in the arid southern tropical Andes.

  18. Quaternary glaciation of the Lato Massif, Zanskar Range of the NW Himalaya

    Science.gov (United States)

    Orr, Elizabeth N.; Owen, Lewis A.; Saha, Sourav; Caffee, Marc W.; Murari, Madhav K.

    2018-03-01

    The glacial chronostratigraphy and history of the Lato Massif of Zanskar northern India is defined for the first time using geomorphic mapping and 10Be surface exposure dating. Three local glacial stages, the Lato, Shiyul and Kyambu, are dated to 244-49, 25-15 and 3.4-0.2 ka, respectively. The Lato glacial stage was the most extensive period of glaciation, characterized by expanded ice caps with glaciers advancing to ∼16 km from their present position. Large till deposits are associated with this glacial stage, which represent a time of heightened glacial erosion and localized incision, and increased rates of sediment transfer and deposition. The glacial style transitioned to entrenched valley glaciation during the Shiyul glacial stage. Hummocky moraine complexes reflecting fluctuating glacier margins characterize this glaciation. Glaciers have been confined to the cirques and headwalls of the massif during and since the Kyambu glacial stage. Equilibrium-line altitude (ELA) reconstructions help define the shifts in glaciation over time, with ELA depressions changing from 470 ± 140, 270 ± 80 to 100 ± 30 m for the Lato, Shiyul and Kyambu glacial stages, respectively. The change of glacial style during the latter part of the Quaternary is similar to other regions of the Transhimalaya and Tibet suggesting that this pattern of glaciation may reflect regional climatic forcing. The evolution of the Lato Massif from an isolated alpine plateau to a steeply incised massif over the last several glacial-interglacial cycles may have also influenced the shifts from ice cap to valley glaciation.

  19. Quaternary glaciation of Mount Everest

    Science.gov (United States)

    Owen, Lewis A.; Robinson, Ruth; Benn, Douglas I.; Finkel, Robert C.; Davis, Nicole K.; Yi, Chaolu; Putkonen, Jaakko; Li, Dewen; Murray, Andrew S.

    2009-07-01

    The Quaternary glacial history of the Rongbuk valley on the northern slopes of Mount Everest is examined using field mapping, geomorphic and sedimentological methods, and optically stimulated luminescence (OSL) and 10Be terrestrial cosmogenic nuclide (TCN) dating. Six major sets of moraines are present representing significant glacier advances or still-stands. These date to >330 ka (Tingri moraine), >41 ka (Dzakar moraine), 24-27 ka (Jilong moraine), 14-17 ka (Rongbuk moraine), 8-2 ka (Samdupo moraines) and ˜1.6 ka (Xarlungnama moraine), and each is assigned to a distinct glacial stage named after the moraine. The Samdupo glacial stage is subdivided into Samdupo I (6.8-7.7 ka) and Samdupo II (˜2.4 ka). Comparison with OSL and TCN defined ages on moraines on the southern slopes of Mount Everest in the Khumbu Himal show that glaciations across the Everest massif were broadly synchronous. However, unlike the Khumbu Himal, no early Holocene glacier advance is recognized in the Rongbuk valley. This suggests that the Khumbu Himal may have received increased monsoon precipitation in the early Holocene to help increase positive glacier mass balances, while the Rongbuk valley was too sheltered to receive monsoon moisture during this time and glaciers could not advance. Comparison of equilibrium-line altitude depressions for glacial stages across Mount Everest reveals asymmetric patterns of glacier retreat that likely reflects greater glacier sensitivity to climate change on the northern slopes, possibly due to precipitation starvation.

  20. Cervical Cap

    Science.gov (United States)

    ... p020041. Accessed Nov. 11, 2014. Cervical cap About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  1. Cervical Cap

    Science.gov (United States)

    ... Things That Help Feelings Expert Answers Q&A Movies & More for Teens Teens site Sitio para adolescentes ... Because the cap has to be placed properly, women who use one should be comfortable feeling for ...

  2. Cervical Cap

    Science.gov (United States)

    ... weeks after delivery Can be inserted hours before sex and remain in place for up to 48 hours Doesn't require a partner's cooperation Poses few if any side effects The cervical cap isn't appropriate for everyone, ...

  3. The timing of Late Pleistocene glaciation at Mount Wilhelm, Papua New Guinea

    Science.gov (United States)

    Mills, Stephanie; Barrows, Timothy; Hope, Geoff; Pillans, Brad; Fifield, Keith

    2016-04-01

    The highlands of New Guinea were the most extensively glaciated area in the Asian tropical region during the Late Pleistocene. Evidence for glaciation is widespread on most of the mountain peaks above ~3500 m. Glacial landforms include both valley and ice cap forms, but the timing of glaciation remains constrained to only a few local areas. This paper focuses on Mount Wilhelm, which is situated in the central southern region of Papua New Guinea at 5.78°S and is the highest peak (4510 m a.s.l.) We focus on a south easterly valley (Pindaunde Valley) emanating from the peak, where large moraines indicate the maximum ice extent of a valley glacier ~5 km long. Within this extensive moraine complex, recessional moraines document the retreat of the glacier towards the summit region. In order to determine the timing of deglaciation, we collected samples for surface exposure dating using 36Cl and 10Be from diorite boulders positioned on moraine crests. The ages indicate that maximum ice extent was attained during the last glacial maximum (LGM) and that ice remained near its maximum extent until after 15 ka but persisted at higher elevations almost until the Holocene. These results are similar to those described from Mt Giluwe to the northwest of Mount Wilhelm, where an ice cap reached its maximum extent at the LGM and remained there for around 3-4,000 years. This indicates that full glacial conditions were only brief in this region of the tropics.

  4. Paleoceanography. Antarctic role in Northern Hemisphere glaciation.

    Science.gov (United States)

    Woodard, Stella C; Rosenthal, Yair; Miller, Kenneth G; Wright, James D; Chiu, Beverly K; Lawrence, Kira T

    2014-11-14

    Earth's climate underwent a major transition from the warmth of the late Pliocene, when global surface temperatures were ~2° to 3°C higher than today, to extensive Northern Hemisphere glaciation (NHG) ~2.73 million years ago (Ma). We show that North Pacific deep waters were substantially colder (4°C) and probably fresher than the North Atlantic Deep Water before the intensification of NHG. At ~2.73 Ma, the Atlantic-Pacific temperature gradient was reduced to <1°C, suggesting the initiation of stronger heat transfer from the North Atlantic to the deep Pacific. We posit that increased glaciation of Antarctica, deduced from the 21 ± 10-meter sea-level fall from 3.15 to 2.75 Ma, and the development of a strong polar halocline fundamentally altered deep ocean circulation, which enhanced interhemispheric heat and salt transport, thereby contributing to NHG. Copyright © 2014, American Association for the Advancement of Science.

  5. Pleistocene glaciation of the Jackson Hole area, Wyoming

    Science.gov (United States)

    Pierce, Kenneth L.; Licciardi, Joseph M.; Good, John M.; Jaworowski, Cheryl

    2018-01-24

    Pleistocene glaciations and late Cenozoic offset on the Teton fault have played central roles in shaping the scenic landscapes of the Teton Range and Jackson Hole area in Wyoming. The Teton Range harbored a system of mountain-valley glaciers that produced the striking geomorphic features in these mountains. However, the comparatively much larger southern sector of the Greater Yellowstone glacial system (GYGS) is responsible for creating the more expansive glacial landforms and deposits that dominate Jackson Hole. The glacial history is also inextricably associated with the Yellowstone hotspot, which caused two conditions that have fostered extensive glaciation: (1) uplift and consequent cold temperatures in greater Yellowstone; and (2) the lowland track of the hotspot (eastern Snake River Plain) that funneled moisture to the Yellowstone Plateau and the Yellowstone Crescent of High Terrain (YCHT).The penultimate (Bull Lake) glaciation filled all of Jackson Hole with glacial ice. Granitic boulders on moraines beyond the south end of Jackson Hole have cosmogenic 10Be exposure ages of ~150 thousand years ago (ka) and correlate with Marine Isotope Stage 6. A thick loess mantle subdues the topography of Bull Lake moraines and caps Bull Lake outwash terraces with a reddish buried soil near the base of the loess having a Bk horizon that extends down into the outwash gravel. The Bull Lake glaciation of Jackson Hole extended 48 kilometers (km) farther south than the Pinedale, representing the largest separation of these two glacial positions in the Western United States. The Bull Lake is also more extensive than the Pinedale on the west (22 km) and southwest (23 km) margins of the GYGS but not on the north and east. This pattern is explained by uplift and subsidence on the leading and trailing “bow-wave” of the YCHT, respectively.During the last (Pinedale) glaciation, mountain-valley glaciers of the Teton Range extended to the western edge of Jackson Hole and built

  6. Geoprospective study of a nuclear waste repository. Climatology: climatic changes and glaciations

    International Nuclear Information System (INIS)

    Courbouleix, S.

    1985-01-01

    Within the frame of a contract with the CEC dealing with storage and disposal of radioactive wastes in geological formations, the B.R.G.M. has been involved in a research on climatic changes and glaciations. For over three million years, the terrestrial environment has undergone a climate crisis, which causes are still discussed. 700 000 years ago, the paroxysm of this crisis was caracterized by the development of big ice-caps in the northern hemisphere. The last important glacial expansion - the Wurm- begun 70 000 years ago and ended less than 10 000 years ago. Since then, the climate warmed up slightly again with the ''small glacial age'' between the 16th and the 19th centuries. All glaciers regressed during a warmer phase lasting about one century, but, since 1945, the trend is again to a deep in temperature, the climatologists are not able to agree on its causes and its possible develoment. Considering the amplitude and the frequency of the Quaternary climatic changes, it is difficult to think that the glacial crisis is over. Many arguments let suppose the contrary. Therefore, all evidences lead, to the probability of at least one new glaciation wither the next 100 000 years. The problem is to know its importance and when it will occur. If during the present interglacial time, all ices could melt, one can expect a rise sea-levels of about 80 m. On the contrary, in the case of a future glaciation of the same amplitude as the previous one, the stocking of waters by the ice-caps would bring down the sea-level to 120 m which would lead to an important erosion period and a drastic change in landscapes

  7. Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation

    International Nuclear Information System (INIS)

    Stübner, Konstanze; Grin, Elena; Hidy, Alan J.; Schaller, Mirjam; Gold, Ryan D.

    2017-01-01

    Glacial chronologies provide insight into the evolution of paleo-landscapes, paleoclimate, topography, and the erosion processes that shape mountain ranges. In the Pamir of Central Asia, glacial morphologies and deposits indicate extensive past glaciations, whose timing and extent remain poorly constrained. Geomorphic data and 15 new 10 Be exposure ages from moraine boulders and roches moutonnées in the southwestern Pamir document multiple Pleistocene glacial stages. The oldest exposure ages, View the MathML source113 ± 10ka, underestimate the age of the earliest preserved glacial advance and imply that the modern relief of the southwestern Pamir (peaks at ~5000–6000 m a.s.l.; valleys at ~2000–3000 m a.s.l.) already existed in the late Middle Pleistocene. Younger exposure ages (~40–80 ka, ~30 ka) complement the existing Central Asian glacial chronology and reflect successively less extensive Late Pleistocene glaciations. The topography of the Pamir and the glacial chronologies suggest that, in the Middle Pleistocene, an ice cap or ice field occupied the eastern Pamir high-altitude plateau, whereas westward flowing valley glaciers incised the southwestern Pamir. Since the Late Pleistocene deglaciation, the rivers of the southwestern Pamir adjusted to the glacially shaped landscape. As a result, localized rapid fluvial incision and drainage network reorganization reflect the transient nature of the deglaciated landscape.

  8. Cradle Cap (For Parents)

    Science.gov (United States)

    ... for Educators Search English Español Cradle Cap (Infantile Seborrheic Dermatitis) KidsHealth / For Parents / Cradle Cap (Infantile Seborrheic Dermatitis) What's in this article? About Cradle Cap Causes ...

  9. The Glaciation of the Ecuadorian Andes

    Science.gov (United States)

    Schubert, Carlos

    This pleasing book fills the gap in the knowledge about Pleistocene and recent glaciation between Colombia and Peru. A significant amount of data exists already for Colombia and Venezuela and for Peru, Bolivia, and, particularly, Chile. Hastenrath has now given us a description of glaciers and glaciation underneath the equator in the Andes.The book begins with brief summaries of the physiography and the atmospheric circulation, which give the general setting of Ecuador. Then follow detailed descriptions of the glaciers and glacial morphology of all the important mountains of the Western and Eastern Cordilleras. These are well illustrated, and a particularly useful feature is the comparison of old photographs and paintings of glaciers with modern photographs, many taken by the author. All illustrate the spectacular retreat of the glaciers in the Ecuadorian Andes during the last century and correlate quite well with observations elsewhere. This retreat is snown quantitatively in Table 4, in terms of decrease in glacier-covered area since the glacial advance of moraine stage III. The area of present-day glaciers is about 10% of the area during that stage (compared with about 1.5% in the Sierra Nevada de Mérida, Venezuela). A series of maps show the glacial morphology of the mountains (unfortunately, some of the maps have been included within the binding, thus losing some information; they could have been reduced somewhat to fit a single page or, if too large, could have been included in the pocket, together with the map of Chimborazo-Carihuairazo).

  10. A geochemical modelling study of the evolution of the chemical composition of seawater linked to a "snowball" glaciation

    Directory of Open Access Journals (Sweden)

    G. Le Hir

    2008-02-01

    Full Text Available The Snowball Earth theory initially proposed by Kirschvink (1992 to explain the Neoproterozoic glacial episodes, suggested that the Earth was fully ice-covered at 720 Ma (Sturtian episode and 640 Ma (Marinoan episode. This succession of extreme climatic crises induced environmental perturbations which are considered as a strong selective pressure on the evolution of life (Hoffman et al., 1998. Using a numerical model of carbon-alkalinity global cycles, we quantify environmental stresses caused by a global glaciation. According to our results, we suggest that during global glaciations, the ocean becomes acidic (pH~6, and undersaturated with respect to carbonate minerals. Moreover the quick transition from ice-house to greenhouse conditions implies an abrupt and large shift of the oceanic surface temperature which causes an extended hypoxia. The intense continental weathering, in the aftermath of the glaciation, deeply affects the seawater composition inducing rapid changes in terms of pH and alkalinity. We also propose a new timing for post glacial perturbations and for the cap carbonates deposition, ~2 Myr instead of 200 kyr as suggested in a previous modelling study. In terms of Precambrian life sustainability, seawater pH modifications appear drastic all along the glaciation, but we suggest that the buffering action of the oceanic crust dissolution avoids a total collapse of biological productivity. But short-lived and large post-glacial perturbations are more critical and may have played the role of an environmental filter proposed in the classic snowball Earth theory. Although the link between environmental changes and life sustainability cannot be modelled accurately, we suggest that only a permissive life (Knoll, 2003 may explain the relative continuity in microfossils diversity observed before, during and after Neoproterozoic glaciation events.

  11. Asynchronous glaciations in arid continental climate

    Science.gov (United States)

    Batbaatar, Jigjidsurengiin; Gillespie, Alan R.; Fink, David; Matmon, Ari; Fujioka, Toshiyuki

    2018-02-01

    Mountain glaciers at ∼26-19 ka, during the global Last Glacial Maximum near the end of the last 105 yr glacial cycle, are commonly considered on the basis of dating and field mapping in several well-studied areas to have been the largest of the late Quaternary and to have advanced synchronously from region to region. However, a numerical sensitivity model (Rupper and Roe, 2008) predicts that the fraction of ablation due to melting varies across Central Asia in proportion to the annual precipitation. The equilibrium-line altitude of glaciers across this region likely varies accordingly: in high altitude, cold and arid regions sublimation can ablate most of the ice, whereas glaciers fed by high precipitation cannot ablate completely due to sublimation alone, but extend downhill until higher temperatures there cause them to melt. We have conducted field studies and 10Be dating at five glaciated sites along a precipitation gradient in Mongolia to test the Rupper/Roe model. The sites are located in nearby 1.875 × 1.875° cells of the Rupper/Roe model, each with a different melt fraction, in this little-studied region. The modern environment of the sites ranges from dry subhumid in the north (47.7° N) to arid in the south (45° N). Our findings show that the maximum local advances in the dry subhumid conditions predated the global Last Glacial Maximum and were likely from MIS 3. However, we also found that at ∼8-7 ka a cirque glacier in one mountain range of the arid Gobi desert grew to a magnitude comparable to that of the local maximum extent. This Holocene maximum occurred during a regional pluvial period thousands of years after the retreat of the Pleistocene glaciers globally. This asynchronous behavior is not predicted by the prevailing and generally correct presumption that glacier advances are dominantly driven by temperature, although precipitation also plays a role. Our findings are consistent with and support the Rupper/Roe model, which calls for

  12. Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography

    Science.gov (United States)

    Stubner, Konstanze; Grin, Elena; Hidy, Alan J.; Schaller, Mirjam; Gold, Ryan D.; Ratschbacher, Lothar; Ehlers, Todd

    2017-01-01

    Glacial chronologies provide insight into the evolution of paleo-landscapes, paleoclimate, topography, and the erosion processes that shape mountain ranges. In the Pamir of Central Asia, glacial morphologies and deposits indicate extensive past glaciations, whose timing and extent remain poorly constrained. Geomorphic data and 15 new 10Be exposure ages from moraine boulders and roches moutonnées in the southwestern Pamir document multiple Pleistocene glacial stages. The oldest exposure ages, , underestimate the age of the earliest preserved glacial advance and imply that the modern relief of the southwestern Pamir (peaks at ∼5000–6000 m a.s.l.; valleys at ∼2000–3000 m a.s.l.) already existed in the late Middle Pleistocene. Younger exposure ages (∼40–80 ka, ∼30 ka) complement the existing Central Asian glacial chronology and reflect successively less extensive Late Pleistocene glaciations. The topography of the Pamir and the glacial chronologies suggest that, in the Middle Pleistocene, an ice cap or ice field occupied the eastern Pamir high-altitude plateau, whereas westward flowing valley glaciers incised the southwestern Pamir. Since the Late Pleistocene deglaciation, the rivers of the southwestern Pamir adjusted to the glacially shaped landscape. Localized rapid fluvial incision and drainage network reorganization reflect the transient nature of the deglaciated landscape.

  13. Tectonic controls of Holocene erosion in a glaciated orogen

    OpenAIRE

    Adams, Byron A.; Ehlers, Todd A.

    2018-01-01

    Recent work has highlighted a strong, worldwide, glacial impact of orogen erosion rates over the last 2 Ma. While it may be assumed that glaciers increased erosion rates when active, the degree to which past glaciations influence Holocene erosion rates through the adjustment of topography is not known. In this study, we investigate the influence of long-term tectonic and post-glacial topographic controls on erosion in a glaciated orogen, the Olympic Mountains, USA. We present 14 new 10Be and ...

  14. Baltica in the Cryogenian, 850-630 Ma, in S.V. Bogdanova, X-X. Li, E.M. Moores and S.A. Pisarevsky (Eds.), Testing the Rodinia Hypothesis: Records in its Building Blocks

    NARCIS (Netherlands)

    Pease, V.; Daly, J.; Elming, S.-A.; Kumpulainen, R.; Mcozydlowska, M.; Puchkov, V.; Roberts, D.; Stephenson, R.A.; Saintot, A.N.

    2008-01-01

    This new tectonic synthesis provides a framework for understanding the dynamic evolution of Baltica and for constraining tectonic correlations within the context of the Neoproterozoic break-up of Rodinia-Pannotia. Cryogenian Baltica is described with respect to five geographic regions: the

  15. Mineral chemistry as a tool for understanding the petrogenesis of Cryogenian (arc-related)-Ediacaran (post-collisional) gabbros in the western Arabian Shield of Saudi Arabia

    Science.gov (United States)

    Surour, Adel A.; Ahmed, Ahmed H.; Harbi, Hesham M.

    2017-07-01

    Metagabbros and gabbros in the Ablah-Shuwas belt (western Saudi Arabia) represent part of significant mafic magmatism in the Neoproterozoic Arabian Shield. The metagabbros are Cryogenian, occasionally stratified and bear calcic amphiboles (hornblende, magnesio-hornblende and actinolite) typical of calc-alkaline complexes. These amphiboles suggest low pressure ( 1-3 kbar), high f_{{{{O}}2 }} and crystallization temperature up to 727 °C, whereas it is 247-275 °C in the case of retrograde chlorite. Rutile and titanite in metagabbros are Fe-rich and replace Mn-bearing ilmenite precursors at high f_{{{{O}}2 }}. On the other hand, younger gabbros are fresh, layered and comprised of olivine gabbro and olivine-hornblende gabbro with an uppermost layer of anorthositic gabbro. The fresh gabbros are biotite-bearing. They are characterized by secondary magnetite-orthopyroxene symplectitic intergrowth at the outer peripheries of olivine. The symplectite forms by deuteric alteration from residual pore fluids moving along olivine grain boundaries in the sub-solidus state. In fresh gabbros, ortho- and clinopyroxenes indicate crystallization at 1300-900 and 800-600 °C, respectively. Geochemically, the Cryogenian metagabbros ( 850-780 Ma) are tholeiitic to calc-alkaline in composition and interpreted as arc-related. Younger, fresh gabbros are calc-alkaline and post-collisional ( 620-590 Ma, i.e., Ediacaran), forming during the late stages of arc amalgamation in the southern Arabian Shield. The calc-alkaline metagabbros are related to a lithospheric mantle source previously modified by subduction. Younger, fresh gabbros were probably produced by partial melting of an enriched mantle source (e.g., garnet lherzolite).

  16. Expert Panel Elicitation of Seismicity Following Glaciation in Sweden

    International Nuclear Information System (INIS)

    Hora, Stephen; Jensen, Mikael

    2005-12-01

    The Swedish Radiation Protection Authority, the Swedish Nuclear Power Inspectorate and the Swedish Nuclear Fuel and Waste Management Company have jointly carried out a project on expert panel elicitation on the issue of glacial induced Swedish earthquakes. Following a broad nomination procedure, 5 experts were chosen by a selection committee of 4 professors within Earth sciences disciplines. The 5 experts presented judgments about the frequency of earthquakes greater the magnitude 6 within 10 km for two Swedish sites, Oskarshamn and Forsmark, in connection with a glaciation cycle. The experts' median value vas 0,1 earthquakes for one glaciation cycle

  17. Expert Panel Elicitation of Seismicity Following Glaciation in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Hora, Stephen; Jensen, Mikael (eds.)

    2005-12-15

    The Swedish Radiation Protection Authority, the Swedish Nuclear Power Inspectorate and the Swedish Nuclear Fuel and Waste Management Company have jointly carried out a project on expert panel elicitation on the issue of glacial induced Swedish earthquakes. Following a broad nomination procedure, 5 experts were chosen by a selection committee of 4 professors within Earth sciences disciplines. The 5 experts presented judgments about the frequency of earthquakes greater the magnitude 6 within 10 km for two Swedish sites, Oskarshamn and Forsmark, in connection with a glaciation cycle. The experts' median value vas 0,1 earthquakes for one glaciation cycle.

  18. Triple oxygen isotope evidence for elevated CO2 levels after a Neoproterozoic glaciation.

    Science.gov (United States)

    Bao, Huiming; Lyons, J R; Zhou, Chuanming

    2008-05-22

    Understanding the composition of the atmosphere over geological time is critical to understanding the history of the Earth system, as the atmosphere is closely linked to the lithosphere, hydrosphere and biosphere. Although much of the history of the lithosphere and hydrosphere is contained in rock and mineral records, corresponding information about the atmosphere is scarce and elusive owing to the lack of direct records. Geologists have used sedimentary minerals, fossils and geochemical models to place constraints on the concentrations of carbon dioxide, oxygen or methane in the past. Here we show that the triple oxygen isotope composition of sulphate from ancient evaporites and barites shows variable negative oxygen-17 isotope anomalies over the past 750 million years. We propose that these anomalies track those of atmospheric oxygen and in turn reflect the partial pressure of carbon dioxide (P(CO2)) in the past through a photochemical reaction network linking stratospheric ozone to carbon dioxide and to oxygen. Our results suggest that P(CO2) was much higher in the early Cambrian than in younger eras, agreeing with previous modelling results. We also find that the (17)O isotope anomalies of barites from Marinoan (approximately 635 million years ago) cap carbonates display a distinct negative spike (around -0.70 per thousand), suggesting that by the time barite was precipitating in the immediate aftermath of a Neoproterozoic global glaciation, the P(CO2) was at its highest level in the past 750 million years. Our finding is consistent with the 'snowball Earth' hypothesis and/or a massive methane release after the Marinoan glaciation.

  19. Microtubule's conformational cap

    DEFF Research Database (Denmark)

    Flyvbjerg, H.

    1999-01-01

    The molecular mechanisms that allow elongation of the unstable microtubule lattice remain unclear. It is usually thought that the GDP-liganded tubulin lattice is capped by a small layer of GTP- or GDP-P(i)-liganded molecules, the so called "GTP-cap". Here, we point-out that the elastic properties...

  20. Predictability of seabed texture: spatial scaling of grain size and bathymetry on glaciated and non-glaciated shelves

    Science.gov (United States)

    Kostylev, V.

    2010-12-01

    In mapping seabed texture inherent predictability of sediment grain size is the key to the success of spatial interpolations. With low and stationary spatial variance the variable should be easy to predict while otherwise the results of interpolation are untrustworthy. Conceptual model known as 1/f^β noise offers a compelling way to describe predictability of environmental patterns. I have studied spatial spectra of mean grain size of surficial seabed sediments from two datasets roughly corresponding to glaciated (Canadian) and non-glaciated (US) shelves. Data for the Atlantic Canadian waters were obtained from Natural Resources Canada Expedition Database (23666 samples). For United States waters the Gulf of Mexico and Caribbean coastal and offshore data (17765 samples) as well as Atlantic Coast offshore surficial sediment data (33907 samples) were obtained from the usSEABED database. Spatial variances of mean grain size were calculated for samples separated by distance bins ranging from 1 to 1000 km. On scales from kilometers to hundreds of kilometers power spectrum of mean grain size in the studied datasets may be characterized as white noise (β = 0), indistinguishable from uniform random distribution (β =0.097 for Canada and β =0.009 for US). Power spectrum of grain size co-varies with bathymetry in US dataset across all scales. In the Canadian dataset this relationship holds up to 100 km, after which bathymetric and grain size variability become dissociated, and bathymetric variability increasing while sediment variability being relatively constant. Variance of US grain size data exhibits rapid increase in spatial variance on scales of 100 km and higher (β = 1.501). This exponent value falls between pink (β = 1) and red (Brownian, β = 2) noise and indicates that spatial patterns at larger sample separations are more predictable. There are several possible explanations for high spatial variance in grain size at relatively small sample separation (1 - 100

  1. Northern hemisphere glaciation during the globally warm early Late Pliocene.

    Directory of Open Access Journals (Sweden)

    Stijn De Schepper

    Full Text Available The early Late Pliocene (3.6 to ∼3.0 million years ago is the last extended interval in Earth's history when atmospheric CO2 concentrations were comparable to today's and global climate was warmer. Yet a severe global glaciation during marine isotope stage (MIS M2 interrupted this phase of global warmth ∼3.30 million years ago, and is seen as a premature attempt of the climate system to establish an ice-age world. Here we propose a conceptual model for the glaciation and deglaciation of MIS M2 based on geochemical and palynological records from five marine sediment cores along a Caribbean to eastern North Atlantic transect. Our records show that increased Pacific-to-Atlantic flow via the Central American Seaway weakened the North Atlantic Current and attendant northward heat transport prior to MIS M2. The consequent cooling of the northern high latitude oceans permitted expansion of the continental ice sheets during MIS M2, despite near-modern atmospheric CO2 concentrations. Sea level drop during this glaciation halted the inflow of Pacific water to the Atlantic via the Central American Seaway, allowing the build-up of a Caribbean Warm Pool. Once this warm pool was large enough, the Gulf Stream-North Atlantic Current system was reinvigorated, leading to significant northward heat transport that terminated the glaciation. Before and after MIS M2, heat transport via the North Atlantic Current was crucial in maintaining warm climates comparable to those predicted for the end of this century.

  2. Quaternary glaciation of the Tashkurgan Valley, Southeast Pamir

    Science.gov (United States)

    Owen, Lewis A.; Chen, Jie; Hedrick, Kathyrn A.; Caffee, Marc W.; Robinson, Alexander C.; Schoenbohm, Lindsay M.; Yuan, Zhaode; Li, Wenqiao; Imrecke, Daniel B.; Liu, Jinfeng

    2012-07-01

    The Quaternary glacial history of Tashkurgan valley, in the transition between the Pamir and Karakoram, in Xinjiang Province, China was examined using remote sensing, field mapping, geomorphic analysis of landforms and sediments, and 10Be terrestrial cosmogenic nuclide dating. Moraines were assigned to four glacial stages: 1) the Dabudaer glacial stage that dates to the penultimate glacial cycle and/or earlier, and may represent one or more glaciations; 2) the Tashkurgan glacial stage that dates to early last glacial, most likely Marine Oxygen Isotope Stage (MIS) 4; 3) the Hangdi glacial stage that dates to MIS 2, possibly early MIS 2; and 4) the Kuzigun glacial stage that dates to the MIS 2, possibly the global Last Glacial Maximum, and is younger than the Hangdi glacial stage. Younger moraines and rock glaciers are present at the heads of tributary valleys; but these were inaccessible because they are located close to politically sensitive borders with Pakistan, Afghanistan and Tajikistan. Glaciers during the Dabudaer glacial stage advanced into the central part of the Tashkurgan valley. During the Tashkurgan glacial stages, glaciers advanced several kilometers beyond the mouths of the tributary valleys into the Tashkurgan valley. Glaciers during the Hangdi and Kuzigun glacial stages advanced just beyond the mouths of the tributary valleys. Glaciation in this part of the Himalayan-Tibetan orogen is likely strongly controlled by northern hemisphere climate oscillations, although a monsoonal influence on glaciation cannot be ruled out entirely.

  3. Biomarkers of a Low-Latitude Neoproterozoic Glaciation

    Science.gov (United States)

    Olcott, A. N.; Sessions, A. L.; Corsetti, F. A.; Kaufman, A. J.

    2005-12-01

    Neoproterozoic low-latitude glaciations are often considered times of great biologic limitation because of the hypothesized presence of thick, global sea ice. Alternatively, climate models have suggested that tropical oceans could have remained ice-free, or covered by only thin sea ice, allowing life to continue unimpeded throughout the glaciations. The analysis of organic remains from synglacial sediments provides an approach to address the debate. Here we describe molecular, isotopic, and petrographic analyses of organic rich strata (up to 3.0 percent TOC) deposited in southeastern Brazil during Neoproterozoic low-latitude glaciation ca. 700 Ma. These strata contain extractable biomarkers, including 2-α-methyl hopanes, 2,3,6-trimethylarylisoprenoids, C29-C31 hopanes, and C27-C29 steranes. The preserved biomarkers reflect the presence of a complex and productive ecosystem comprised of both aerobic and anaerobic phototrophs, heterotrophs, and eukaryotes. The biomarker data indicate euxinia extending into the photic zone, providing evidence that the oceans were strongly stratified. Significantly, the occurrence of photosynthetic cyanobacteria and green sulfur bacteria at this time indicates that sea-ice cover at this location was thin to nonexistent, and is incompatible with models for snowball Earth that envision kilometers of ice thickness.

  4. Shelf ice glaciation in the Arctic Ocean? New results from northernmost Greenland

    Science.gov (United States)

    Kjaer, K.; Moller, P.; Larsen, N. K.

    2007-12-01

    Bounding on the last remaining patch of permanent sea ice and capped by an ice sheet with meltwater sufficient to disrupt the thermohaline circulation, North Greenland is strategically located for contributing to the understanding of the climate system. The coastal plain, which faces the Arctic Ocean, more than 100 km long and 15 km wide, is covered by a continuous blanket of Quaternary sediment that spans at least the period since the last deglaciation c. 9000 years ago, and is capped by an array of glacial and marine landforms. This area therefore contains an unsurpassed source for recording marine and glacial activities along the world's northernmost coast - a source which, owing to its inaccessibility, has largely remained untapped. Preliminary results from the 'LongTerm Project', which ended this summer, show that at least two major glacial events hit the coasts by the end of the last ice age. One of them was possibly a large scale expansion of the Inland Ice resulting in formation of a 100,000 km2 ice shelf in the Arctic Ocean - a type of glaciation, which has usually been thought to be an Antarctic speciality. Even more significantly, abundant accumulations of glacio- fluvial and -lacustrine sediments show that heat transfer to these extreme latitudes by the end of the last ice age was sufficient to allow massive melting of land-based ice. Finally, among the summer's surprises was the discovery of thick piles of raised marine sediments along the coast, allowing a detailed record of sea level history and faunal change, which can be correlated with a terrestrial record from cores, obtained from two lakes on the coastal plain.

  5. Early Paleozoic paleogeography of the northern Gondwana margin: new evidence for Ordovician-Silurian glaciation

    Science.gov (United States)

    Semtner, A.-K.; Klitzsch, E.

    1994-12-01

    During the Early Paleozoic, transgressions and the distribution of sedimentary facies on the northern Gondwana margin were controlled by a regional NNW-SSE to almost north-south striking structural relief. In Early Silurian times, a eustatic highstand enabled the sea to reach its maximum southward extent. The counterclockwise rotation of Gondwana during the Cambrian and Early Ordovician caused the northern Gondwana margin to shift from intertropical to southern polar latitudes in Ordovician times. Glacial and periglacial deposits are reported from many localities in Morocco, Algeria, Niger, Libya, Chad, Sudan, Jordan and Saudi Arabia. The Late Ordovician glaciation phase was followed by a period of a major glacioeustatic sea-level rise in the Early Silurian due to the retreat of the ice-cap. As a consequence of the decreasing water circulation in the basin centers (Central Arabia, Murzuk- and Ghadames basins), highly bituminous euxinic shales were deposited. These shales are considered to be the main source rock of Paleozoic oil and gas deposits in parts of Saudi Arabia, Libya and Algeria. The following regression in the southern parts of the Early Silurian sea was probably caused by a second glacial advance, which was mainly restricted to areas in Chad, Sudan and Niger. Evidence for glacial activity and fluvioglacial sedimentation is available from rocks overlying the basal Silurian shale in north-east Chad and north-west Sudan. The Early Silurian ice advance is considered to be responsible for the termination of euxinic shale deposition in the basin centers.

  6. Precambrian supercontinents, glaciations, atmospheric oxygenation, metazoan evolution and an impact that may have changed the second half of Earth history

    Directory of Open Access Journals (Sweden)

    Grant M. Young

    2013-05-01

    Full Text Available In more than 4 Ga of geological evolution, the Earth has twice gone through extreme climatic perturbations, when extensive glaciations occurred, together with alternating warm periods which were accompanied by atmospheric oxygenation. The younger of these two episodes of climatic oscillation preceded the Cambrian “explosion” of metazoan life forms, but similar extreme climatic conditions existed between about 2.4 and 2.2 Ga. Over long time periods, changing solar luminosity and mantle temperatures have played important roles in regulating Earth's climate but both periods of climatic upheaval are associated with supercontinents. Enhanced weathering on the orogenically and thermally buoyed supercontinents would have stripped CO2 from the atmosphere, initiating a cooling trend that resulted in continental glaciation. Ice cover prevented weathering so that CO2 built up once more, causing collapse of the ice sheets and ushering in a warm climatic episode. This negative feedback loop provides a plausible explanation for multiple glaciations of the Early and Late Proterozoic, and their intimate association with sedimentary rocks formed in warm climates. Between each glacial cycle nutrients were flushed into world oceans, stimulating photosynthetic activity and causing oxygenation of the atmosphere. Accommodation for many ancient glacial deposits was provided by rifting but escape from the climatic cycle was predicated on break-up of the supercontinent, when flooded continental margins had a moderating influence on weathering. The geochemistry of Neoproterozoic cap carbonates carries a strong hydrothermal signal, suggesting that they precipitated from deep sea waters, overturned and spilled onto continental shelves at the termination of glaciations. Paleoproterozoic (Huronian carbonates of the Espanola Formation were probably formed as a result of ponding and evaporation in a hydrothermally influenced, restricted rift setting. Why did metazoan

  7. Time scale bias in erosion rates of glaciated landscapes.

    Science.gov (United States)

    Ganti, Vamsi; von Hagke, Christoph; Scherler, Dirk; Lamb, Michael P; Fischer, Woodward W; Avouac, Jean-Philippe

    2016-10-01

    Deciphering erosion rates over geologic time is fundamental for understanding the interplay between climate, tectonic, and erosional processes. Existing techniques integrate erosion over different time scales, and direct comparison of such rates is routinely done in earth science. On the basis of a global compilation, we show that erosion rate estimates in glaciated landscapes may be affected by a systematic averaging bias that produces higher estimated erosion rates toward the present, which do not reflect straightforward changes in erosion rates through time. This trend can result from a heavy-tailed distribution of erosional hiatuses (that is, time periods where no or relatively slow erosion occurs). We argue that such a distribution can result from the intermittency of erosional processes in glaciated landscapes that are tightly coupled to climate variability from decadal to millennial time scales. In contrast, we find no evidence for a time scale bias in spatially averaged erosion rates of landscapes dominated by river incision. We discuss the implications of our findings in the context of the proposed coupling between climate and tectonics, and interpreting erosion rate estimates with different averaging time scales through geologic time.

  8. The Neoproterozoic Puga (Varanger) cap carbonate, Amazon Craton, Brazil

    Science.gov (United States)

    Riccomini, C.; Nogueira, A. C.; Sial, A. N.; Moura, C. A.; Fairchild, T. R.

    2003-04-01

    Based on stratigraphic and isotopic data the basal carbonates of the Araras Group overlying diamictites of the Puga Formation at the southwest margin of the Amazon Craton are interpreted as a Neoproterozoic cap carbonate. Deposited below wavebase on a carbonate platform, this cap consists of two units separated by a transgressive erosional surface. The lower unit comprises moderately deep to shallow-water pinkish dolomudstone with stratiform fenestrate stromatolites, fenestrate planar lamination, ridge ("tepee-like structures") and tubiform structures. The upper unit includes deep-water bituminous lime mudstones with terrigenous grains, and subordinate shales. Alternating thin calcite crusts and lime mudstone laminae are commonly disrupted by calcite crystal fans (pseudomorphs after aragonite). Brecciated, faulted, and slumped limestone beds with multiple generations of cement indicate localized synsedimentary deformation. Negative excursions of δ13C and variations in 87Sr/86Sr are consistent with a Varanger age. However, unlike other cap carbonates, the basal contact with diamictites exhibits soft-sediment deformation, providing unequivocal sedimentological evidence of rapid dolostone precipitation after ice-melting. This fact confirms the existence of an abrupt change from icehouse to extreme greenhouse conditions, as proposed in the snowball earth hypothesis for Neoproterozoic glaciation. (Financial support: FAPESP grant 00/02903-8, CNPq and Pró-Reitoria de Pós-Graduação, USP).

  9. A simple model for 100 K-year oscillations in glaciation

    Science.gov (United States)

    Lindzen, R. S.

    1986-01-01

    A simple climatic model which produces glaciation cycles of 100 K periods in response to forcing by 20 K, 40 K, and 100 K periods is described. The model is based on Milankovitch's (1930) hypothesis that glaciation fluctuations are forced by orbital variation and the associated change in insolation. The sea ice/snow cover line for the model, and the relation between heat variations and the ice/snow line are analyzed. The sea ice/snow cover line for the model is between the pole and 53 deg latitude and the line's position is the forcing for the glaciation cycle. Examples of the model's response to forcing are presented and evaluated. The negative glaciation permitted by the model is studied. The role of CO2 feedback in the glaciation cycle is investigated.

  10. Saltstone Clean Cap Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C

    2005-04-22

    The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended

  11. Saltstone Clean Cap Formulation

    International Nuclear Information System (INIS)

    Langton, C

    2005-01-01

    The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended

  12. A new model of Pleistocene glaciation in the northern Urals

    Science.gov (United States)

    Astakhov, V. I.

    2017-10-01

    This is an overview of the latest data on the age of topographically expressed glacigenic formations of the Polar Urals obtained by international geological teams by modern dating techniques including optical luminescence, radiocarbon and cosmogenic beryllium in exposed boulders. The new dates combined with the results of geological mapping and remote sensing data is a basis for rejecting the concept of the Quaternary Uralian ice caps in favor of small alpine glaciers which developed south of the Kara ice sheet.

  13. Minimal erosion of Arctic alpine topography during late Quaternary glaciation

    Science.gov (United States)

    Gjermundsen, Endre F.; Briner, Jason P.; Akçar, Naki; Foros, Jørn; Kubik, Peter W.; Salvigsen, Otto; Hormes, Anne

    2015-10-01

    The alpine topography observed in many mountainous regions is thought to have formed during repeated glaciations of the Quaternary period. Before this time, landscapes had much less relief. However, the spatial patterns and rates of Quaternary exhumation at high latitudes--where cold-based glaciers may protect rather than erode landscapes--are not fully quantified. Here we determine the exposure and burial histories of rock samples from eight summits of steep alpine peaks in northwestern Svalbard (79.5° N) using analyses of 10Be and 26Al concentrations. We find that the summits have been preserved for at least the past one million years. The antiquity of Svalbard’s alpine landscape is supported by the preservation of sediments older than one million years along a fjord valley, which suggests that both mountain summits and low-elevation landscapes experienced very low erosion rates over the past million years. Our findings support the establishment of northwestern Svalbard’s alpine topography during the early Quaternary. We suggest that, as the Quaternary ice age progressed, glacial erosion in the Arctic became inefficient and confined to ice streams, and high-relief alpine landscapes were preserved by minimally erosive glacier armour.

  14. Early to middle Holocene valley glaciations on northernmost Greenland

    DEFF Research Database (Denmark)

    Möller, Per; Larsen, Nicolaj K.; Kjær, Kurt H.

    2010-01-01

    This paper presents the glacial stratigraphy and palaeoenvironmental evolution around Constable Bugt, Johannes V. Jensen Land, located on the north coast of Greenland. This is a land of extreme climate: polar desert conditions and a coast bound by a permanent sea ice cover. Our data covers...... the period from the Last Glacial Maximum (LGM, 18e22 cal ka BP) into the Holocene. It records the history of a shelf-based glaciation with ice flowing eastward along the coast as well as two local valley glacier advances from the south during the Holocene. With ice on the coastal plain during the LGM......, glaciolacustrine basins formed in marginal positions and in ice-dammed valleys to the south into the mountainous area of Peary Land. With the break-up of shelf-based ice there was a gradual marine inundation at which the marine limit formed at w45 m a.s.l. This initial early Holocene ice advance from the south...

  15. Understanding and modelling Neo-proterozoic glaciations and their associated phenomena

    International Nuclear Information System (INIS)

    Le Hir, Guillaume

    2007-01-01

    The objective of this research thesis is to provide a consistent image of extreme glaciations which occurred during the Neo-proterozoic era. By using climate and carbon cycle models (or model of bio-geochemical cycles), the author aims at answering various scientific questions raised by the Snowball Earth hypothesis. After a description of the main geological features which characterize the Proterozoic, scientific problems are presented. The author then reports the study of carbon cycle during glaciation in order to understand its operation. Based on this constraint, a consistent scenario of exit from glaciation is defined. The physical-chemical evolution of the ocean during and after a global glaciation is then quantified in order to assess its potential effects on the environment and on the Precambrian biosphere. The last part focuses on the post-glacial evolution to establish the delay for a return to equilibrium of climate after such an extreme event [fr

  16. Cryogenian alkaline magmatism in the Southern Granulite Terrane, India: Petrology, geochemistry, zircon U-Pb ages and Lu-Hf isotopes

    Science.gov (United States)

    Santosh, M.; Yang, Qiong-Yan; Ram Mohan, M.; Tsunogae, T.; Shaji, E.; Satyanarayanan, M.

    2014-11-01

    22 Ma correlating with the ages of the basement rocks from these areas. The initial 176Hf/177Hf isotope ratios of the zircon grains from the AM syenite fall in the range between 0.281771 and 0.282284, with moderately negative εHf(t) values between - 5.9 and 0.1. Similarly, the initial 176Hf/177Hf isotope ratios for the zircon grains of PM ultrapotassic granite range between 0.281197 and 0.281970, albeit with more negative εHf(t) values in the range between - 22.7 and - 0.3 (average εHf (t) value - 18.8). The Lu-Hf data suggest the involvement of variable extent of older crust with distinct crustal residence times, either in the form of assimilation during magma emplacement, or crustal recycling during magma genesis. Based on the geochemical and isotopic systematics, a possible petrogenetic model would be asthenospheric upwelling in an extensional setting, melting of enriched lithosphere, and interaction of the magmas with lower crustal domains with subduction-related components of various ages. The disposition of these alkali plutons along two paleo sutures that weld the Meso-Neoarchean crustal blocks in the northern periphery of SGT suggests that the zones of emplacement might represent an aborted rift. The paleo-sutures probably served as a weak zone along which extension occurred broadly coeval with the Cryogenian subduction further south.

  17. ATLAS end-cap detector

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Three scientists from the Institute of Nuclear Phyiscs at Novossibirsk with one of the end-caps of the ATLAS detector. The end-caps will be used to detect particles produced in the proton-proton collisions at the heart of the ATLAS experiment that are travelling close to the axis of the two beams.

  18. Groundwater flow and transport modelling during a glaciation period

    International Nuclear Information System (INIS)

    Jaquet, O.; Siegel, P.

    2003-01-01

    Subsequent to earlier work, SKB has decided to carry out additional hydrogeological modelling studies related to glaciation effects at Aespoe. In particular, sub glacial groundwater flow and the impact assessment on a repository require further studies. As compared to the previous model, the domain geometry and processes involved remain identical, but this time, numerical calculations are performed with the NAMMU package (version 7.1.1) using a finite element formulation. Modified assumptions corresponding to specific boundary conditions are implemented and additional variations of the base case are simulated. The objectives of the study are based on the technical specifications established by SKB. The main objectives may be summarised as follows: Enhancement of the understanding of sub glacial groundwater flow due to basal ice melting. Evaluation of the impact of sub glacial roundwater flow on a repository with respect to its position to the ice margin of the glacier. Assessment of the feasibility of performing large 3D simulations of density-driven flow induced by variable salinity of the groundwater using the NAMMU package. The report begins with an account of the modelling approach applied. Then, the results of the different cases simulated are described, analysed and interpreted in detail. Finally, conclusions are drawn up together with some recommendations related to potential modelling issues for the future. The objectives proposed for the groundwater flow and transport modelling for period of glaciation have been met: The results have shown the importance of the ice tunnels in governing sub glacial groundwater flow due to basal ice melting. The influence of the ice tunnels on the salinity distribution is significant as is their impact on the flow trajectories and, hence, on the resulting travel times. The results of simulation S0 have revealed that no steady-state flow conditions are reached. Due to the chosen salt boundary conditions, salt will continue to

  19. Good Regulatory Lags for Price Cap and Rolling Cap contracts

    OpenAIRE

    Jose Luis Lima R; Andres Gomez Lobo

    2004-01-01

    Price caps are a popular form of monopoly price regulation. One of its disadvantages is the perverse incentives that regulated firms might have to scamp on cost reducing effort during the last years before a price review. In order to avoid this problem a “rolling cap†contract was introduced in the United Kingdom that overcomes this last problem. In spite of their popularity, there is scant research on the optimal regulatory lag (number of years between price reviews) of a price cap or rol...

  20. Glaciation's topographic control on Holocene erosion at the eastern edge of the Alps

    Science.gov (United States)

    Dixon, Jean L.; von Blanckenburg, Friedhelm; Stüwe, Kurt; Christl, Marcus

    2016-12-01

    What is the influence of glacial processes in driving erosion and uplift across the European Alps? It has largely been argued that repeated erosion and glaciation sustain isostatic uplift and topography in a decaying orogen. But some parts of the Alps may still be actively uplifting via deep lithospheric processes. We add insight to this debate by isolating the role of post-glacial topographic forcing on erosion rates. To do this, we quantify the topographic signature of past glaciation on millennial-scale erosion rates in previously glaciated and unglaciated catchments at the easternmost edge of the Austrian Alps. Newly measured catchment-wide erosion rates, determined from cosmogenic 10Be in river-borne quartz, correlate with basin relief and mean slope. GIS-derived slope-elevation and slope-area distributions across catchments provide clear topographic indicators of the degree of glacial preconditioning, which further correlates with erosion rates. Erosion rates in the easternmost, non-glaciated basins range from 40 to 150 mm ky-1 and likely reflect underlying tectonic forcings in this region, which have previously been attributed to recent (post 5 Ma) uplift. By contrast, erosion rates in previously glaciated catchments range from 170 to 240 mm ky-1 and reflect the erosional response to local topographic preconditioning by repeated glaciations. Together, these data suggest that Holocene erosion across the Eastern Alps is strongly shaped by the local topography relict from previous glaciations. Broader, landscape-wide forcings, such as the widely debated deep mantle-driven or isostatically driven uplift, result in lesser controls on both topography and erosion rates in this region. Comparing our data to previously published erosion rates across the Alps, we show that post-glacial erosion rates vary across more than 2 orders of magnitude. This high variation in post-glacial erosion may reflect combined effects of direct tectonic and modern climatic forcings but

  1. Late Quaternary glaciation history of monsoon-dominated Dingad basin, central Himalaya, India

    Science.gov (United States)

    Shukla, Tanuj; Mehta, Manish; Jaiswal, Manoj K.; Srivastava, Pradeep; Dobhal, D. P.; Nainwal, H. C.; Singh, Atul K.

    2018-02-01

    The study presents the Late Quaternary glaciation history of monsoon-dominated Dokriani Glacier valley, Dingad basin, central Himalaya, India. The basin is tested for the mechanism of landforms preservation in high relief and abundant precipitation regimes of the Higher Himalaya. Field geomorphology and remote sensing data, supported by Optical Stimulated Luminescence (OSL) dating enabled identification of five major glacial events of decreasing magnitude. The oldest glacial stage, Dokriani Glacial Stage I (DGS-I), extended down to ∼8 km (2883 m asl) from present-day snout (3965 m asl) followed by other four glaciations events viz. DGS-II, DGS-III, DGS-IV and DGS-V terminating at ∼3211, 3445, 3648 and ∼3733 m asl respectively. The DGS-I glaciation (∼25-∼22 ka BP) occurred during early Marine Isotope Stage (MIS) -2, characterized as Last Glacial Maximum (LGM) extension of the valley. Similarly, DGS-II stage (∼14-∼11 ka BP) represents the global cool and dry Older Dryas and Younger Dryas event glaciation. The DGS-III glaciation (∼8 ka BP) coincides with early Holocene 8.2 ka cooling event, the DGS-IV glaciations (∼4-3.7 ka BP) corresponds to 4.2 ka cool and drier event, DGS-V (∼2.7-∼1 ka BP) represents the cool and moist late Holocene glacial advancement of the valley. This study suggests that the Dokriani Glacier valley responded to the global lowering of temperature and variable precipitation conditions. This study also highlights the close correlation between the monsoon-dominated valley glaciations and Northern Hemisphere cooling events influenced by North Atlantic climate.

  2. Impact of the Wisconsinian Glaciation on Canadian Continental Groundwater Flow

    Science.gov (United States)

    Lemieux, J.; Sudicky, E. A.; Peltier, W. R.; Tarasov, L.

    2005-12-01

    During the last glacial period (75 kyr - 10 kyr), the Canadian landscape was almost entirely covered with ice. The Laurentide ice-sheet, the largest of the three North-American ice sheets, reached a thickness of about 4 km and the force exerted by its weight on the earth's crust was sufficient to cause a depression of the surface of about 1 km and an over-pressurization of porewater fluids. These dramatic conditions are suspected to have had a large impact on the groundwater flow system over the whole continent. Although an analysis of the evolution of groundwater flow systems during glacial periods is relevant to a number of problems, such as the long-term stability of high-level spent nuclear-fuel repositories located at depth, very few studies have been conducted to assess the impact of glaciation on deep-seated groundwater flow systems, particularly in a North-American context. A transient, three-dimensional groundwater flow model including the effect of the advective-dispersive redistribution of shield brines was constructed in order to capture the impact of the advance and retreat of the ice sheet over the Canadian landscape. The model is driven by a thermomechanical ice-sheet model of the last glacial cycle [Tarasov and Peltier, 2004] which provides the transient boundary conditions that includes the spatio-temporal distribution of the glacial ice, the elevation of the surface topography, meltwater rates, permafrost thicknesses, as well as temporal changes in sea level along the coastal margins. The evolving surface water drainage patterns and features such as proglacial lakes are also incorporated based on the hydrologic routing calculations performed by Tarasov and Peltier [2005]. The treatment of physical processes related to the influence of the ice sheet on the groundwater flow system such as hydromechanics, isostasy, subglacial melting and permafrost formation are also discussed. Simulation results show that hydraulic heads at depth below the ice sheet

  3. The North Zealand CAP Monitor

    DEFF Research Database (Denmark)

    Nielsen, Minna; Ravn, Pernille; Notander Clausen, Lise

    Contect We describe how we developed a monitoring system for community acquired pneumonia (CAP) at North Zealand Regional hospital. We serve 310.000 inhabitants and annually around 3200 patients with CAP are admitted. As part of a program of clinical pathways for common conditions, a pathway...... nurses and two senior doctors. Direct observations of the clinical processes revealed problems of coordination, complex disease trajectories that did not fit with the pneumonia pathway, unclear guidelines and variation in their interpretation. Intervention We designed a measurement system to monitor...... with CAP. We started with 34 audit variables. Through repeated cycles of testing, feedback and discussions, we reduced the number of indicators to 22 and time per audit from 20 to 10 minutes. Strategy for change To link the monitoring system with our patient pathway for CAP we established an improvement...

  4. Erosion patterns produced by the paleo Haizishan ice cap, SE Tibetan Plateau

    Science.gov (United States)

    Fu, P.; Stroeven, A. P.; Harbor, J.; Hättestrand, C.; Heyman, J.; Caffee, M. W.

    2017-12-01

    Erosion is a primary driver of landscape evolution, topographic relief production, geochemical cycles, and climate change. Combining in situ 10Be and 26Al exposure age dating, geomorphological mapping, and field investigations, we examine glacial erosion patterns of the almost 4,000 km2 paleo Haizishan ice cap on the southeastern Tibetan Plateau. Our results show that ice caps on the low relief Haizishan Plateau produced a zonal pattern of landscape modification. In locations where apparent exposure ages on bedrock are consistent with the last deglaciation, complete resetting of the cosmogenic exposure age clock indicates glacial erosion of at least a few meters. However, older apparent exposure ages on bedrock in areas known to have been covered by the paleo ice cap during the Last Glacial Maximum indicate inheritance and thus limited glacial erosion. Inferred surface exposure ages from cosmogenic depth profiles through two saprolites vary from resetting and thus saprolite profile truncation to nuclide inheritance indicating limited erosion. Finally, significant nuclide inheritance in river sand samples from basins on the scoured plateau surface also indicate limited glacial erosion during the last glaciation. Hence, for the first time, our study shows clear evidence of preservation under non-erosive ice on the Tibetan Plateau. As patterns of glacial erosion intensity are largely driven by the basal thermal regime, our results confirm earlier inferences from geomorphology for a concentric basal thermal pattern for the paleo Haizishan ice cap during the LGM.

  5. Multiproxy isotope constraints on ocean compositional changes across the late Neoproterozoic Ghaub glaciation, Otavi Group, Namibia

    DEFF Research Database (Denmark)

    Rodler, Alexandra; Frei, Robert; Gaucher, C.

    2017-01-01

    of the Otavi Group, Namibia, stretching over four stages from preglacial setting to retreat of the late Neoproterozoic Ghaub glaciation (∼635 Ma). The fluctuating but generally heavy δ53Cr signals indicate oxygenated shallow seawater prior to the glaciation (stage 1). Sustained high δ13Ccarb signatures...... the carbon cycle and oxygen availability (stage 2). Prior to the Ghaub diamictite, a sequence of 87Sr/86Sr in the range typical of late Neoproterozoic seawater occurs with high Sr concentrations, low Mn/Sr and low Mg/Ca. Enhanced detrital input after the Ghaub glaciation (stage 3) indicates elevated...... records typical late Neoproterozoic seawater 87Sr/86Sr ratios. The carbonate δ53Cr signatures at the base of the postglacial sequence are characterized by values even below the range of bulk silicate Earth (BSE). We hypothesize that this is due to (i) redox cycling of Cr in seawater, e.g. by (partial...

  6. Sensitivity of glaciation in the arid subtropical Andes to changes in temperature, precipitation, and solar radiation

    Science.gov (United States)

    Vargo, L. J.; Galewsky, J.; Rupper, S.; Ward, D. J.

    2018-04-01

    The subtropical Andes (18.5-27 °S) have been glaciated in the past, but are presently glacier-free. We use idealized model experiments to quantify glacier sensitivity to changes in climate in order to investigate the climatic drivers of past glaciations. We quantify the equilibrium line altitude (ELA) sensitivity (the change in ELA per change in climate) to temperature, precipitation, and shortwave radiation for three distinct climatic regions in the subtropical Andes. We find that in the western cordillera, where conditions are hyper-arid with the highest solar radiation on Earth, ELA sensitivity is as high as 34 m per % increase in precipitation, and 70 m per % decrease in shortwave radiation. This is compared with the eastern cordillera, where precipitation is the highest of the three regions, and ELA sensitivity is only 10 m per % increase in precipitation, and 25 m per % decrease in shortwave radiation. The high ELA sensitivity to shortwave radiation highlights the influence of radiation on mass balance of high elevation and low-latitude glaciers. We also consider these quantified ELA sensitivities in context of previously dated glacial deposits from the regions. Our results suggest that glaciation of the humid eastern cordillera was driven primarily by lower temperatures, while glaciations of the arid Altiplano and western cordillera were also influenced by increases in precipitation and decreases in shortwave radiation. Using paleoclimate records from the timing of glaciation, we find that glaciation of the hyper-arid western cordillera can be explained by precipitation increases of 90-160% (1.9-2.6× higher than modern), in conjunction with associated decreases in shortwave radiation of 7-12% and in temperature of 3.5 °C.

  7. NATURE MANAGEMENT, LANDSCAPE AND THE CAP

    OpenAIRE

    Brouwer, Floor M.; Godeschalk, Frans E.

    2004-01-01

    The integration of nature management, landscape and environmental concerns into the Common Agricultural Policy (CAP) has gained momentum with the CAP reforms adopted in June 2003. The report explores instruments and approaches that contribute to the inte-gration of nature conservation and landscape concerns into the CAP. A broader use of the CAP instruments might help to achieve nature types in the Netherlands.

  8. Simulating the amplification of orbital forcing by ocean feedbacks in the last glaciation.

    Science.gov (United States)

    Khodri, M; Leclainche, Y; Ramstein, G; Braconnot, P; Marti, O; Cortijo, E

    2001-03-29

    According to Milankovitch theory, the lower summer insolation at high latitudes about 115,000 years ago allowed winter snow to persist throughout summer, leading to ice-sheet build-up and glaciation. But attempts to simulate the last glaciation using global atmospheric models have failed to produce this outcome when forced by insolation changes only. These results point towards the importance of feedback effects-for example, through changes in vegetation or the ocean circulation-for the amplification of solar forcing. Here we present a fully coupled ocean-atmosphere model of the last glaciation that produces a build-up of perennial snow cover at known locations of ice sheets during this period. We show that ocean feedbacks lead to a cooling of the high northern latitudes, along with an increase in atmospheric moisture transport from the Equator to the poles. These changes agree with available geological data and, together, they lead to an increased delivery of snow to high northern latitudes. The mechanism we present explains the onset of glaciation-which would be amplified by changes in vegetation-in response to weak orbital forcing.

  9. Glaciation in the surroundings of Prášilské Lake (Bohemian Forest, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Mentlík, P.; Minár, J.; Břízová, E.; Lisá, Lenka; Tábořík, P.; Stacke, V.

    2010-01-01

    Roč. 117, 1/2 (2010), s. 181-194 ISSN 0169-555X Institutional research plan: CEZ:AV0Z30130516 Keywords : Bohemian Forest * Pleistocene glaciations * Prášilské Lake * Šumava * sedimentology * chronology Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.352, year: 2010

  10. The key role of global solid-Earth processes in preconditioning Greenland's glaciation since the Pliocene

    NARCIS (Netherlands)

    Steinberger, Bernhard; Spakman, Wim; Japsen, Peter; Torsvik, Trond H.

    After >500 Ma of absence, major Northern Hemisphere glaciations appeared during the Plio-Pleistocene, with Greenland leading other northern areas. Here, we propose that three major solid-Earth processes underpinned build-up of the Greenland ice-sheet. First, a mantle-plume pulse, responsible for the

  11. The effects of the final stages of the Late Ordovician glaciation on marine palynomorphs (chitinozoans, acritarchs, leiospheres) in well Nl-2 (NE Algerian Sahara).

    Science.gov (United States)

    Paris, F; Bourahrouh, A; Hérissé, A L.

    2000-12-01

    Palynomorph assemblages, especially chitinozoans and acritarchs, from the Upper Ordovician of well Nl-2 (north-east of the Algerian Sahara) are studied in order to precisely date the ultimate effects of the Late Ordovician glaciation and to document the impact of this major climatic stress on the diversity of the palynoplankton. References are made to stable isotope excursions and to global eustatic sea level variations in order to improve the local age determination. The Hassi el Hadjar Formation, i.e. glacio-marine diamictites, is interpreted as a transgressive event resulting from the melting of the northern Gondwana ice cap. It yields poorly preserved and moderately diverse chitinozoans of late Hirnantian age. Acritarchs are more abundant in the lower part of these "microconglomeratic clays", but display a low diversity and are badly preserved throughout the whole formation. Reworked individuals are recorded in both groups. The marine sediments of the M'Kratta Formation of latest Hirnantian age contain better preserved, more abundant and more diverse palynomorph assemblages, especially in the Upper Member. The composition of this palynoplankton indicates a fairly good faunal and phytoplankton recovery after the early Hirnantian climatic stress.The extinction of the Ordovician forms, and the appearance of Silurian type taxa occur only in the uppermost Hirnantian, i.e. following with a slight delay the glacial event. The overlying black shales of Wenlock age (lower part of the Oued Mehaiguène Formation) are indicative of marine anoxic environments. They yield a virtually exclusive, but enormous number of Tasmanacea. The very peculiar composition of this palynoplankton seems to be independent of the Late Ordovician glaciation and is most likely related to the factors that, later, generated and maintained anoxic conditions in this area.A new species of chitinozoan, Spinachitina oulebsiri sp. nov. from the latest Hirnantian M'Kratta Formation, is described and

  12. Glaciation's topographic control on Holocene erosion at the eastern edge of the Alps

    Directory of Open Access Journals (Sweden)

    J. L. Dixon

    2016-12-01

    Full Text Available What is the influence of glacial processes in driving erosion and uplift across the European Alps? It has largely been argued that repeated erosion and glaciation sustain isostatic uplift and topography in a decaying orogen. But some parts of the Alps may still be actively uplifting via deep lithospheric processes. We add insight to this debate by isolating the role of post-glacial topographic forcing on erosion rates. To do this, we quantify the topographic signature of past glaciation on millennial-scale erosion rates in previously glaciated and unglaciated catchments at the easternmost edge of the Austrian Alps. Newly measured catchment-wide erosion rates, determined from cosmogenic 10Be in river-borne quartz, correlate with basin relief and mean slope. GIS-derived slope–elevation and slope–area distributions across catchments provide clear topographic indicators of the degree of glacial preconditioning, which further correlates with erosion rates. Erosion rates in the easternmost, non-glaciated basins range from 40 to 150 mm ky−1 and likely reflect underlying tectonic forcings in this region, which have previously been attributed to recent (post 5 Ma uplift. By contrast, erosion rates in previously glaciated catchments range from 170 to 240 mm ky−1 and reflect the erosional response to local topographic preconditioning by repeated glaciations. Together, these data suggest that Holocene erosion across the Eastern Alps is strongly shaped by the local topography relict from previous glaciations. Broader, landscape-wide forcings, such as the widely debated deep mantle-driven or isostatically driven uplift, result in lesser controls on both topography and erosion rates in this region. Comparing our data to previously published erosion rates across the Alps, we show that post-glacial erosion rates vary across more than 2 orders of magnitude. This high variation in post-glacial erosion may reflect combined effects of direct

  13. Capping Drugs: Development of Prodrugs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 2. Capping Drugs: Development of Prodrugs. H Surya Prakash Rao. General Article Volume 8 Issue 2 February 2003 pp 19-27. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/02/0019-0027 ...

  14. From Blogs to Bottle Caps

    Science.gov (United States)

    Edinger, Ted

    2012-01-01

    There is a wonderful community of art educators connecting a once-isolated profession through blogging. Art educators around the world are sharing ideas and communicating with their peers through this amazing resource. In this article, the author describes the bottle cap mural at Tulip Grove Elementary School which was inspired by this exchange of…

  15. Crustal movements due to Iceland's shrinking ice caps mimic magma inflow signal at Katla volcano.

    Science.gov (United States)

    Spaans, Karsten; Hreinsdóttir, Sigrún; Hooper, Andrew; Ófeigsson, Benedikt Gunnar

    2015-05-20

    Many volcanic systems around the world are located beneath, or in close proximity to, ice caps. Mass change of these ice caps causes surface movements, which are typically neglected when interpreting surface deformation measurements around these volcanoes. These movements can however be significant, and may closely resemble movements due to magma accumulation. Here we show such an example, from Katla volcano, Iceland. Horizontal movements observed by GPS on the flank of Katla have led to the inference of significant inflow of magma into a chamber beneath the caldera, starting in 2000, and continuing over several years. We use satellite radar interferometry and GPS data to show that between 2001 and 2010, the horizontal movements seen on the flank can be explained by the response to the long term shrinking of ice caps, and that erratic movements seen at stations within the caldera are also not likely to signify magma inflow. It is important that interpretations of geodetic measurements at volcanoes in glaciated areas consider the effect of ice mass change, and previous studies should be carefully reevaluated.

  16. CAP binding proteins associated with the nucleus.

    OpenAIRE

    Patzelt, E; Blaas, D; Kuechler, E

    1983-01-01

    Cap binding proteins of HeLa cells were identified by photo-affinity labelling using the cap analogue gamma-[32P]-[4-(benzoyl-phenyl)methylamido]-7-methylguanosine-5'- triphosphate. Photoreaction with whole cell homogenates resulted in specific labelling of five major polypeptides. The small molecular weight polypeptide appeared to be identical to the 24 000 to 26 000 dalton cap binding protein previously identified in initiation factors. A cap binding protein of 37 000 dalton was found in in...

  17. Analyses of hydraulic performance of velocity caps

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Degn Eskesen, Mark Chr.; Buhrkall, Jeppe

    2014-01-01

    The hydraulic performance of a velocity cap has been investigated. Velocity caps are often used in connection with offshore intakes. CFD (computational fluid dynamics) examined the flow through the cap openings and further down into the intake pipes. This was combined with dimension analyses...

  18. Determining the rates and drivers of headwall erosion within glaciated catchments in the NW Himalaya

    Science.gov (United States)

    Orr, E.; Owen, L. A.; Saha, S.; Caffee, M. W.

    2017-12-01

    Rates of headwall erosion are defined for fourteen glaciated catchments in the NW Himalaya by measuring 10Be terrestrial cosmogenic nuclide concentrations in supraglacial debris. The investigated catchments are located throughout three broad climatic zones, which include the Lesser Himalaya (rainfall >1000 mm a-1), Greater Himalaya (500-1000 mm a-1) and Transhimalaya (arid catchments that are occupied by sub-polar glaciers, suggesting that there are additional controls upon periglacial domain landscape change. Other factors and catchment-specific dynamics influencing these landscapes include, temperature, surface processes, topography, valley morphology, geologic setting and glacial history. Defining rates of headwall erosion is one of the first steps to understanding the nature of sediment production and transfer within high-altitude glaciated catchments, and highlights the importance of periglacial rockfall processes in landscape evolution.

  19. GLANAM (Glaciated North Atlantic Margins): A Marie Curie Initial Training Network between Norway, the UK & Denmark

    Science.gov (United States)

    Petter Sejrup, Hans; Oline Hjelstuen, Berit

    2015-04-01

    GLANAM (Glaciated North Atlantic Margins) is an Initial Training Network (ITN) funded under the EU Marie Curie Programme. It comprises 10 research partners from Norway, UK and Denmark, including 7 University research teams, 1 industrial full partner and 2 industrial associate partners. The GLANAM network will employ and train 15 early career researchers (Fellows). The aim of GLANAM is to improve the career prospects and development of young researchers in both the public and private sector within the field of earth science, focusing on North Atlantic glaciated margins. The young scientists will perform multi-disciplinary research and receive training in geophysics, remote sensing, GIS, sedimentology, geomorphology, stratigraphy, geochemistry and numerical modeling through three interconnected work packages that collectively address knowledge gaps related to the large, glacial age, sedimentary depocentres on the North Atlantic margin. The 15 Fellows will work on projects that geographically extend from Ireland in the south to the High Arctic. Filling these gaps will not only result in major new insights regarding glacial age processes on continental margins in general, but will also provide paleoclimate information essential for understanding the role of marine-based ice sheets in the climate system and for the testing of climate models. GLANAM brings together leading European research groups working on glaciated margins in a coordinated and collaborative research and training project. Focusing on the North Atlantic margins, this coordinated approach will lead to a major advance in the understanding of glaciated margins more widely and will fundamentally strengthen European research and build capacity in this field.

  20. Multi-scale curvature for automated identification of glaciated mountain landscapes☆

    Science.gov (United States)

    Prasicek, Günther; Otto, Jan-Christoph; Montgomery, David R.; Schrott, Lothar

    2014-01-01

    Erosion by glacial and fluvial processes shapes mountain landscapes in a long-recognized and characteristic way. Upland valleys incised by fluvial processes typically have a V-shaped cross-section with uniform and moderately steep slopes, whereas glacial valleys tend to have a U-shaped profile with a changing slope gradient. We present a novel regional approach to automatically differentiate between fluvial and glacial mountain landscapes based on the relation of multi-scale curvature and drainage area. Sample catchments are delineated and multiple moving window sizes are used to calculate per-cell curvature over a variety of scales ranging from the vicinity of the flow path at the valley bottom to catchment sections fully including valley sides. Single-scale curvature can take similar values for glaciated and non-glaciated catchments but a comparison of multi-scale curvature leads to different results according to the typical cross-sectional shapes. To adapt these differences for automated classification of mountain landscapes into areas with V- and U-shaped valleys, curvature values are correlated with drainage area and a new and simple morphometric parameter, the Difference of Minimum Curvature (DMC), is developed. At three study sites in the western United States the DMC thresholds determined from catchment analysis are used to automatically identify 5 × 5 km quadrats of glaciated and non-glaciated landscapes and the distinctions are validated by field-based geological and geomorphological maps. Our results demonstrate that DMC is a good predictor of glacial imprint, allowing automated delineation of glacially and fluvially incised mountain landscapes. PMID:24748703

  1. Glaciation's topographic control on Holocene erosion at the eastern edge of the Alps

    OpenAIRE

    J. L. Dixon; J. L. Dixon; F. von Blanckenburg; F. von Blanckenburg; K. Stüwe; M. Christl

    2016-01-01

    What is the influence of glacial processes in driving erosion and uplift across the European Alps? It has largely been argued that repeated erosion and glaciation sustain isostatic uplift and topography in a decaying orogen. But some parts of the Alps may still be actively uplifting via deep lithospheric processes. We add insight to this debate by isolating the role of post-glacial topographic forcing on erosion rates. To do this, we quantify the topographic signature of pas...

  2. Assessment of geomorphological and hydrological changes produced by Pleistocene glaciations in a Patagonian basin

    Science.gov (United States)

    Scordo, Facundo; Seitz, Carina; Melo, Walter D.; Piccolo, M. Cintia; Perillo, Gerardo M. E.

    2018-04-01

    This work aims to assess how Pleistocene glaciations modeled the landscape in the upper Senguer River basin and its relationship to current watershed features (drainage surface and fluvial hydrological regime). During the Pleistocene six glacial lobes developed in the upper basin of the Senguer River localized east of the Andean range in southern Argentinean Patagonia between 43° 36' - 46° 27‧ S. To describe the topography and hydrology, map the geomorphology, and propose an evolution of the study area during the Pleistocene we employed multitemporal Landsat images, national geological sheets and a mosaic of the digital elevation model (Shuttle Radar Topography Mission) along with fieldwork. The main conclusion is that until the Middle Pleistocene, the drainage divide of the Senguer River basin was located to the west of its current limits and its rivers drained the meltwater of the glaciers during interglacial periods. However, processes of drainage inversion and drainage surface reduction occurred in the headwater of most rivers of the basin during the Late Pleistocene. Those processes were favored by a relative shorter glacial extension during LGM and the dam effect produced by the moraines of the Post GPG I and III glaciations. Thus, since the Late Pleistocene, the headwaters of several rivers in the basin have been reduced, and the moraines corresponding to the Middle Pleistocene glaciations currently divide the watersheds that drain towards the Senguer River from those that flow west towards the Pacific Ocean.

  3. Geomorphological and sedimentary evidence of probable glaciation in the Jizerské hory Mountains, Central Europe

    Science.gov (United States)

    Engel, Zbyněk; Křížek, Marek; Kasprzak, Marek; Traczyk, Andrzej; Hložek, Martin; Krbcová, Klára

    2017-03-01

    The Jizerské hory Mountains in the Czech Republic have traditionally been considered to be a highland that lay beyond the limits of Quaternary glaciations. Recent work on cirque-like valley heads in the central part of the range has shown that niche glaciers could form during the Quaternary. Here we report geomorphological and sedimentary evidence for a small glacier in the Pytlácká jáma Hollow that represents one of the most-enclosed valley heads within the range. Shape and size characteristics of this landform indicate that the hollow is a glacial cirque at a degraded stage of development. Boulder accumulations at the downslope side of the hollow probably represent a relic of terminal moraines, and the grain size distribution of clasts together with micromorphology of quartz grains from the hollow indicate the glacial environment of a small glacier. This glacier represents the lowermost located such system in central Europe and provides evidence for the presence of niche or small cirque glaciers probably during pre-Weichselian glacial periods. The glaciation limit (1000 m asl) and paleo-ELA (900 m asl) proposed for the Jizerské hory Mountains implies that central European ranges lower than 1100 m asl were probably glaciated during the Quaternary.

  4. Low atmospheric CO2 levels during the Permo- Carboniferous glaciation inferred from fossil lycopsids

    Science.gov (United States)

    Beerling, D. J.

    2002-01-01

    Earth history was punctuated during the Permo-Carboniferous [300–250 million years (Myr) ago] by the longest and most severe glaciation of the entire Phanerozoic Eon. But significant uncertainty surrounds the concentration of CO2 in the atmosphere through this time interval and therefore its role in the evolution of this major prePleistocene glaciation. Here, I derive 24 Late Paleozoic CO2 estimates from the fossil cuticle record of arborsecent lycopsids of the equatorial Carboniferous and Permian swamp communities. Quantitative calibration of Late Carboniferous (330–300 Myr ago) and Permian (270–260 Myr ago) lycopsid stomatal indices yield average atmospheric CO2 concentrations of 344 ppm and 313 ppm, respectively. The reconstructions show a high degree of self-consistency and a degree of precision an order of magnitude greater than other approaches. Low CO2 levels during the Permo-Carboniferous glaciation are in agreement with glaciological evidence for the presence of continental ice and coupled models of climate and ice-sheet growth on Pangea. Moreover, the Permian data indicate atmospheric CO2 levels were low 260 Myr ago, by which time continental deglaciation was already underway. Positive biotic feedbacks on climate, and geotectonic events, therefore are implicated as mechanisms underlying deglaciation. PMID:12235372

  5. Is the extent of glaciation limited by marine gas-hydrates?

    Science.gov (United States)

    Paull, Charles K.; Ussler, William; Dillon, William P.

    1991-01-01

    Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming [Revelle, 1983; Kvenvolden, 1988a; Nisbet, 1990]. We consider the response to sea-level changes by the immense amount of gas-hydrate that exists in continental rise sediments, and suggest that the reverse situation may apply—that release of methane trapped in the deep-sea sediments as gas-hydrates may provide a negative feedback to advancing glaciation. Methane is likely to be released from deep-sea gas-hydrates as sea-level falls because methane gas-hydrates decompose with pressure decrease. Methane would be released to sediment pore space at shallow sub-bottom depths (100's of meters beneath the seafloor, commonly at water depths of 500 to 4,000 m) producing zones of markedly decreased sediment strength, leading to slumping [Carpenter, 1981; Kayen, 1988] and abrupt release of the gas. Methane is likely to be released to the atmosphere in spikes that become larger and more frequent as glaciation progresses. Because addition of methane to the atmosphere warms the planet, this process provides a negative feedback to glaciation, and could trigger deglaciation.

  6. Constraining Middle Pleistocene Glaciations in Birmingham, England; Using Optical Stimulated Luminescence (OSL) Dating.

    Science.gov (United States)

    Gibson, S. M.; Gibbard, P. L.; Bateman, M. D.; Boreham, S.

    2014-12-01

    Birmingham is built on a complex sequence of Middle Pleistocene sediments, representing at least three lowland glaciations (MIS12, MIS6, and MIS2). British Geological Survey mapping accounts 75% of the land mass as Quaternary deposits; predominantly glacial-sandy tills, glacial-fluvial sands, clays and organic silts and peats. Understanding the age of fluvial-glacial outwash, related to specific glaciations, is critical in establishing a Geochronology of Birmingham. Shotton (1953) found a series of Middle Pleistocene glacial sediments, termed the Wolstonian, intermediate in age between MIS11 and MIS5e Interglacial's. Uncertainty surrounding the relation to East Anglian sequences developed by Rose (1987) implies Birmingham sequences should be referred to MIS12. Despite this, younger Middle Pleistocene glacial sequences occur in Birmingham, yet uncertainty has deepened over our understanding of the complex, inaccessible sediments, especially as deposits have similar extent with MIS2 sequences. Five Optical Stimulated Luminescence (OSL) dates from three sites around Birmingham have been sampled. East of Birmingham, ice advanced from the Irish Sea and later the North East. In Wolston, a sample of outwash sand, associated with the Thurssington Till, is dated. In Meriden, two samples of outwash sands, associated with a distal Oadby Till, are dated. West of Birmingham, ice advanced from the Welsh Ice Sheet. In Seisdon, two samples of an Esker and outwash sand, associated with a Ridgeacre Till, are dated. Correlation of OSL dates provide an important constraint on understanding the history of Birmingham. Using GSI3D modeling to correlate geochronology and sedimentology, the significance of OSL dating can be understood within the complex sequences (and regional stratigraphy), complimented by Cosmogenic and Palynology dates taken in South West and North East. OSL dating on Birmingham's outwash sands, deposited by extensive repeated Middle Pleistocene glaciations, asserts the

  7. Carbon and Oxygen Isotope Stratigraphy of the Ediacaran Jaíba Formation, Upper Bambuí Group, Brazil: Insights into Paleogeography and Sedimentary Environments after a Neoproterozoic Glaciation.

    Science.gov (United States)

    Caxito, F.; Uhlein, G. J.; Sial, A. N.; Uhlein, A.

    2015-12-01

    The Neoproterozoic Era was a time of extreme climatic variation as recorded in sedimentary rocks of this age across the globe, leading to a number of controversial hypotheses (e.g. the Snowball Earth glaciations). In eastern Brazil, the Bambuí Gr. is a thick carbonatic-siliciclastic unit that covers the São Francisco Craton and preserves remnants of a Neoproterozoic glaciation and their respective cap carbonate (1). Recent findings of Cloudina in the Januária region (2) suggest that at least part of the sequence might be upper Ediacaran or even Cambrian. Here we present the first carbon-oxygen isotope data for the Jaíba Fm., a ca. 50 m thick carbonate unit that occurs in the topmost portion of the Bambuí Gr. in this same region. The Jaíba Fm. post-dates the cap carbonate sequence and the fossil-bearing layers, and thus was probably deposited in the Ediacaran-Cambrian transition. Three stratigraphic columns were analyzed, and yielded similar ratios. Values of δ13CVPDB are between 0.8 and 3.4 ‰, while δ18OVPDB values are mostly around -8 ‰. These values contrasts with the negative δ13C values found for the base of the Bambuí Gr., followed by highly positive δ13C (up to +14‰) on its middle portion. The unusually high δ13C values are commonly interpreted as evidence for deposition on a restricted basin, such as in a foreland setting. The return to values which are close to the PDB standard in the uppermost Bambuí Gr. might thus indicate a change in the paleogeography and tectonic environment of the basin, suggesting an open, ventilated environment along with a recovery of the biological and hydrological cycle after a Late Neoproterozoic glaciation. Ongoing detailed sedimentological, geochemical and isotopic work might help to further clarify these issues and to provide new clues for unraveling Late Neoproterozoic paleoclimate, paleogeography and ocean chemistry. We thank FAPEMIG (Brazil) for finnacial support through grants n. APQ-00914-14 and PPM

  8. A Late-Glacial sedimentary sequence at KIlkeel, Northern Ireland: implications for the glaciation of the Irish Sea Basin

    Science.gov (United States)

    Merritt, Jon; Roberson, Sam; Cooper, Mark

    2017-04-01

    of cross-trough stratified sandy gravels, with flame structures indicative of syn-depositional loading. The entire sequence is capped by loose interbedded sands and gravels (LA4) representing a Late-Glacial raised beach. Evidence of a marine terminating ice margin provides support for high relative sea levels in the north western sector of the Irish Sea during deglaciation. Forthcoming dates from shells with the rafted subaqueous fan deposits underlying LF2 provide the opportunity to constrain either: a) sea-level rise prior to the onset of Irish Sea Basin glaciation, or, b) Late-Glacial sea level rise following deglaciation of the Irish Sea and prior to the re-advance of local ice masses.

  9. Can we apply the 10Be/9Be flux tracer to marine sediments along glaciated margins?

    Science.gov (United States)

    Valletta, R. D.; Willenbring, J. K.; Passchier, S.; Elmi, C.

    2016-12-01

    Radioactive cosmogenic 10Be normalized to its stable isotope 9Be is proposed as a tracer of continental deposition into the marine basins throughout the Late Cenozoic. Close to glaciated margins, 10Be/9Be may reflect shifts in ice sheet dynamics whereby ice sheet retraction is accompanied by increases in freshwater discharge and terrestrial weathering, which may both increase 10Be and 9Be delivery to the continental shelf. However, this signal is complicated by boundary scavenging during periods of warmth and increased productivity. To disentangle the environmental and biological imprint on the 10Be/9Be isotope record, we sampled extensively characterized marine sedimentary packages offshore the Wilkes Subglacial Basin in an area where East Antarctic Ice Sheet (EAIS) retraction and advance is well-established (IODP U1361A). Combining this existing data with our new measurements creates a uniquely large, multi-proxy dataset for geochemical reconstructions along a glaciated margin. We measured 10Be, 9Be and a suite of bio-reactive transition metals from alternating diatom-rich and diatom-poor clay units 1) adsorbed to authigenic clays and 2) contained within diatom frustules, making this the first dataset of its kind. Diatom-rich clay sediments mark abrupt periods of Pliocene warming and a retracted EAIS. Beryllium co-varies with diatom-rich units: maximum 10Be ( 1.3 x 109 atoms g-1) and 9Be ( 300 ng g-1) peak during warmer intervals. These data mimic patterns observed in the nearby Ross Sea (Yokoyama et al., 2016), suggesting that interglacials are marked along glaciated margins by sudden pulses in Be delivery. By accounting for the Be inventory within diatoms, we have allowed for the exciting pairing of 10Be with 26Al to obtain 1) particle flux and 2) freshwater volume discharged from the EAIS during melting events. These values may offer an approach to constraining changes in two elusive parameters: subglacial erosion and ice sheet melt.

  10. Data-mining Based Detection of Glaciers: Quantifying the Extent of Alpine Valley Glaciation

    Directory of Open Access Journals (Sweden)

    Wei Luo

    2015-07-01

    Full Text Available The extent of glaciation in alpine valleys often gives clues to past climates, plate movement, mountain landforms, bedrock geology and more. However, without field investigation, the degree to which a valley was affected by a glacier has been difficult to assess. We developed a model that uses quantitative parameters derived from digital elevations model (DEM data to predict whether a glacier was likely present in an alpine valley. The model's inputs are mainly derived from the basin hypsometry, and a new parameter termed the Hypothetical Basin Equilibrium Elevation (HBEE, which is based on the equilibrium elevation altitude (ELA of a glacier. We used data mining techniques that comb through large data sets to find patterns for classification and prediction as the basis for the model. Four classifiers were utilized, and each was tested with two different training set/test data ratios of nearly 150 basins that were previously delineated as fully- or non-glaciated. The classifiers had a predictive accuracy of up to 90% with none falling below 72%. Two of the classifiers, classification tree and naïve-Bayes, have graphical outputs that visually describe the classification process, predictive results, and in the naïve-Bayes case, the relative effectiveness towards the model of each attribute. In all scenarios, the HBEE was found to be an accurate predictor for the model. The model can be applied to any area where glaciation may have occurred, but is particularly useful in areas where the valley is inaccessible for detailed field investigation.

  11. A short circuit in thermohaline circulation: A cause for northern hemisphere glaciation?

    Science.gov (United States)

    Driscoll; Haug

    1998-10-16

    The cause of Northern Hemisphere glaciation about 3 million years ago remains uncertain. Closing the Panamanian Isthmus increased thermohaline circulation and enhanced moisture supply to high latitudes, but the accompanying heat would have inhibited ice growth. One possible solution is that enhanced moisture transported to Eurasia also enhanced freshwater delivery to the Arctic via Siberian rivers. Freshwater input to the Arctic would facilitate sea ice formation, increase the albedo, and isolate the high heat capacity of the ocean from the atmosphere. It would also act as a negative feedback on the efficiency of the "conveyor belt" heat pump.

  12. Reconstructing Southern Greenland Ice Sheet History During the Plio-Pleistocene Intensification of Northern Hemisphere Glaciation: Insights from IODP Site U1307

    Science.gov (United States)

    Blake-Mizen, K. R.; Hatfield, R. G.; Carlson, A. E.; Walczak, M. H.; Stoner, J. S.; Xuan, C.; Lawrence, K. T.; Bailey, I.

    2017-12-01

    Should it melt entirely, the Greenland Ice Sheet (GrIS) has the potential to raise global sea-level by 7 metres. With the Arctic continuing to warm at a remarkable rate, to better understand how the GrIS will respond to future anthropogenically-induced climate change we must constrain its natural variability in the geological past. In this regard, much uncertainty exists surrounding its pre-Quaternary history; particularly during the mid-Piacenzian warm period (mPWP; 3.3-3.0 Ma) - widely considered an analogue for near-future equilibrium climate with modern atmospheric CO2 levels and elevated temperatures relative to today - and the late Pliocene/early Pleistocene onset of widespread Northern Hemisphere glaciation (NHG, 2.7 Ma). GrIS reconstructions for these intervals have been largely hampered by a lack of well-dated, high-resolution records from suitable sites. To address this, we present new high-resolution, multi-proxy records from IODP Site U1307, a North Atlantic marine sediment core recovered from the Eirik Drift just south of Greenland. Generation of a new high-resolution relative palaeointensity (RPI)-based age-model - representing the first of its kind for high-latitude sediments deposited during NHG - has enabled strong orbital age control. Our ice-rafted debris (IRD) record confirms a 2.72 Ma initiation of major southern GrIS marine-terminating glaciations, which appear to persist even through interglacial periods up to at least 2.24 Ma. XRF-scanning and IRD evidence suggests, however, that an ephemeral ice-cap of likely considerable size persisted on southern Greenland prior to the mPWP. These data, together with the analysed provenance of individual IRD, indicate marine-based GrIS margins extended southward over the NHG interval and only occurred on Greenland's southern tip from 2.7 Ma. Despite a large increase in the deposition of GrIS-derived IRD from this time, bulk sedimentation rates and magnetic grain-size dropped significantly, implying that

  13. Durability of Capped Wood Plastic Composites

    Science.gov (United States)

    Mark Mankowski; Mark J. Manning; Damien P. Slowik

    2015-01-01

    Manufacturers of wood plastic composites (WPCs) have recently introduced capped decking to their product lines. These new materials have begun to take market share from the previous generation of uncapped products that possessed a homogenous composition throughout the thickness of their cross-section. These capped offerings have been introduced with claims that the...

  14. Does uncertainty justify intensity emission caps?

    International Nuclear Information System (INIS)

    Quirion, Philippe

    2005-01-01

    Environmental policies often set 'relative' or 'intensity' emission caps, i.e. emission limits proportional to the polluting firm's output. One of the arguments put forth in favour of relative caps is based on the uncertainty on business-as-usual output: if the firm's production level is higher than expected, so will be business-as-usual emissions, hence reaching a given level of emissions will be more costly than expected. As a consequence, it is argued, a higher emission level should be allowed if the production level is more important than expected. We assess this argument with a stochastic analytical model featuring two random variables: the business-as-usual emission level, proportional to output, and the slope of the marginal abatement cost curve. We compare the relative cap to an absolute cap and to a price instrument, in terms of welfare impact. It turns out that in most plausible cases, either a price instrument or an absolute cap yields a higher expected welfare than a relative cap. Quantitatively, the difference in expected welfare is typically very small between the absolute and the relative cap but may be significant between the relative cap and the price instrument. (author)

  15. Hybrid revenue caps and incentive regulation

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, Bjoern [School of Business, Economics and Law, Gothenburg University, Box 610, 40530 Gothenburg (Sweden)

    2008-05-15

    This paper analyzes the incentive effects of a hybrid revenue cap on a regulated monopolistic firm using non-discriminatory two-part pricing. It is shown that the fixed and the variable part of the cap have different meanings in terms of regulation - the fixed part of a hybrid revenue cap should be used to control the profit level of the regulated firm while the variable part should be used to control the social efficiency level. Since detailed information about the firm's cost function is required to determine the revenue cap parameters, the overall conclusion is that revenue caps are a rather bad idea in the area of incentive regulation. (author)

  16. Antarctic glaciation caused ocean circulation changes at the Eocene-Oligocene transition.

    Science.gov (United States)

    Goldner, A; Herold, N; Huber, M

    2014-07-31

    Two main hypotheses compete to explain global cooling and the abrupt growth of the Antarctic ice sheet across the Eocene-Oligocene transition about 34 million years ago: thermal isolation of Antarctica due to southern ocean gateway opening, and declining atmospheric CO2 (refs 5, 6). Increases in ocean thermal stratification and circulation in proxies across the Eocene-Oligocene transition have been interpreted as a unique signature of gateway opening, but at present both mechanisms remain possible. Here, using a coupled ocean-atmosphere model, we show that the rise of Antarctic glaciation, rather than altered palaeogeography, is best able to explain the observed oceanographic changes. We find that growth of the Antarctic ice sheet caused enhanced northward transport of Antarctic intermediate water and invigorated the formation of Antarctic bottom water, fundamentally reorganizing ocean circulation. Conversely, gateway openings had much less impact on ocean thermal stratification and circulation. Our results support available evidence that CO2 drawdown--not gateway opening--caused Antarctic ice sheet growth, and further show that these feedbacks in turn altered ocean circulation. The precise timing and rate of glaciation, and thus its impacts on ocean circulation, reflect the balance between potentially positive feedbacks (increases in sea ice extent and enhanced primary productivity) and negative feedbacks (stronger southward heat transport and localized high-latitude warming). The Antarctic ice sheet had a complex, dynamic role in ocean circulation and heat fluxes during its initiation, and these processes are likely to operate in the future.

  17. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean.

    Science.gov (United States)

    Coxall, Helen K; Wilson, Paul A; Pälike, Heiko; Lear, Caroline H; Backman, Jan

    2005-01-06

    The ocean depth at which the rate of calcium carbonate input from surface waters equals the rate of dissolution is termed the calcite compensation depth. At present, this depth is approximately 4,500 m, with some variation between and within ocean basins. The calcite compensation depth is linked to ocean acidity, which is in turn linked to atmospheric carbon dioxide concentrations and hence global climate. Geological records of changes in the calcite compensation depth show a prominent deepening of more than 1 km near the Eocene/Oligocene boundary (approximately 34 million years ago) when significant permanent ice sheets first appeared on Antarctica, but the relationship between these two events is poorly understood. Here we present ocean sediment records of calcium carbonate content as well as carbon and oxygen isotopic compositions from the tropical Pacific Ocean that cover the Eocene/Oligocene boundary. We find that the deepening of the calcite compensation depth was more rapid than previously documented and occurred in two jumps of about 40,000 years each, synchronous with the stepwise onset of Antarctic ice-sheet growth. The glaciation was initiated, after climatic preconditioning, by an interval when the Earth's orbit of the Sun favoured cool summers. The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.

  18. Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes

    Science.gov (United States)

    Hauer, F. Richard; Locke, Harvey; Dreitz, Victoria; Hebblewhite, Mark; Lowe, Winsor; Muhlfeld, Clint C.; Nelson, Cara; Proctor, Michael F; Rood, Stewart B.

    2016-01-01

    Gravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologicaltering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.

  19. Simulation of the European ice sheet through the last glacial cycle and prediction of future glaciation

    International Nuclear Information System (INIS)

    Boulton, G.S.; Payne, A.

    1992-12-01

    Global climates of the recent past appear to correlate with patterns of variation in the earths orbit round the sun. As such orbital changes can be predicted into the future, it is argued that the pattern of natural long-term future change can also be estimated. From this, future trends of glaciation can be inferred. The physical and mathematical basis of a time-dependent, thermo mechanically coupled, three dimensional ice sheet model is described. The model is driven by changes in the equilibrium line altitude (ELA) on its surface. This causes flexure of the underlying lithosphere. The model is tuned to the maximum extension of the last (Weichselian) ice sheet and driven by an ELA fluctuation which reflects the NE Atlantic sea surface temperature fluctuation pattern during the last glacial cycle in such a way that the model reproduces the ice sheet margin at the glacial maximum. The distribution of internal ice sheet velocity, temperature, basal melting rate and sub glacial permafrost penetration are all computed. The model is then tested against its predictions of the areal pattern of ice sheet expansion and decay, the pattern of crustal flexure and relative sea level change, and the distribution of till produced by the last European ice sheet. The tested model is then driven by predictions of future climate change to produce simulations of future ice sheet glaciation in northern Europe

  20. Environments during the Kaihinu Interglacial and Otira Glaciation, coastal north Westland, New Zealand

    International Nuclear Information System (INIS)

    Moar, N.; Suggate, R.P.; Burrows, C.

    2008-01-01

    Shoreline gravel of a 47 m raised beach 15 km north of Greymouth, north-west South Island, is overlain by 6 m of lagoonal deposits, beginning with fine organic silts from which pollen records the replacement of an early podocarp-hardwood forest by Nothofagus-podocarp and then by Nothofagus forest. Plant macro-remains, including Dacrydium cupressinum (rimu), Nothofagus menziesii (silver beech), N. truncata (red beech), and N. solandri var. cliffortioides (mountain beech), clarify the nature of these forests. Radiocarbon dates >50,000 14 C yr BP and comparison with other north Westland sequences lead to correlation with the early Kaihinu (Last) Interglacial, and assignment to MIS5e and 5d. Locally overlying are 12 m of interbedded slope deposits and alluvial gravel, together with seven organic silt layers (Bed A down to Bed G). Leaves of Nothofagus menziesii were recovered from Bed G and N. solandri var. cliffortioides from higher layers. Bed B shows a significant Poaceae maximum. Radiocarbon dates from Beds G and E are 42,700 ± 1300 and 22,280 ± 150 14 C yr BP, respectively. The sequence represents much of the Otira (Last) Glaciation, MIS3 and MIS2. The persistence of trees and shrubs at this coastal site is consistent with the inference of closed canopy forest from a site near Westport, but contrasts with the dominance of Poaceae and Cyperaceae at previously studied inland Otira Glaciation sites. (author). 17 refs., 8 figs., 3 tabs

  1. Sensitivity study of rock mass response to glaciation at Finnsjoen, central Sweden

    International Nuclear Information System (INIS)

    Israelsson, J.; Rosengren, L.; Stephansson, O.

    1992-11-01

    The safety analysis SKB-91 of the Swedish Nuclear Fuel and Waste Management Company (SKB) paid specific attention to the glaciation scenario and related phenomena. In the first phase, Rosengren and Stephansson (1990), used the distinct element computer code UDEC to examine the response of the rock mass in the Finnsjoen area to the processes of glaciation and deglaciation. This report describes the second phase, in which the sensitivity of the results to different in situ stresses and fault zone strength properties have been analyzed. A statistical approach was used to extrapolate the range of in-situ stresses at depth from measured in-situ stresses at shallower depths. Three different linear in-situ stress variations with depth were defined using a 99% confidence interval. For each in-situ stress case, three fault zone strength assumptions were analyzed for an ice loading sequence, involving 3 km, 1 km, 0-1 km (ice wedge) and 0 km of ice thickness. Each combination of in-situ stress and fault zone strength was analyzed with and without an ice lake, situated on top of the ice sheet. Consequently, a total of 18 models were studied. The results indicated significant differences in stress distribution, failure (reactivation) of fault zones, and shear displacement on fault zones for some combinations of in-situ stress, fault zone strength, and ice lake pressure. Based on the results, several preliminary recommendations for repository siting are made, as well as recommendations for further study. (authors)

  2. Exploring the MIS M2 glaciation occurring during a warm and high atmospheric CO2 Pliocene background climate

    Science.gov (United States)

    Tan, Ning; Ramstein, Gilles; Dumas, Christophe; Contoux, Camille; Ladant, Jean-Baptiste; Sepulchre, Pierre; Zhang, Zhongshi; De Schepper, Stijn

    2017-08-01

    Prior to the Northern Hemisphere glaciation around ∼2.7 Ma, a large global glaciation corresponding to a 20 to 60 m sea-level drop occurred during Marine Isotope Stage (MIS) M2 (3.312-3.264 Ma), interrupted the period of global warmth and high CO2 concentration (350-450 ppmv) of the mid Piacenzian. Unlike the late Quaternary glaciations, the M2 glaciation only lasted 50 kyrs and occurred under uncertain CO2 concentration (220-390 ppmv). The mechanisms causing the onset and termination of the M2 glaciation remain enigmatic, but a recent geological hypothesis suggests that the re-opening and closing of the shallow Central American Seaway (CAS) might have played a key role. In this article, thanks to a series of climate simulations carried out using a fully coupled Atmosphere Ocean General Circulation Model (GCM) and a dynamic ice sheet model, we show that re-opening of the shallow CAS helps precondition the low-latitude oceanic circulation and affects the related northward energy transport, but cannot alone explain the onset of the M2 glaciation. The presence of a shallow open CAS, together with favourable orbital parameters, 220 ppmv of CO2 concentration, and the related vegetation and ice sheet feedback, led to a global ice sheet build-up producing a global sea-level drop in the lowest range of proxy-derived estimates. More importantly, our results show that the simulated closure of the CAS has a negligible impact on the NH ice sheet melt and cannot explain the MIS M2 termination.

  3. Proceedings from glaciation and hydrogeology. Workshop on the impact of climate change and glaciations on rock stresses, groundwater flow and hydrochemistry - Past, present and future

    International Nuclear Information System (INIS)

    King-Clayton, L.; Chapman, N.; Kautsky, F.

    1997-04-01

    Assessment of the long term safety of radioactive waste disposal requires assimilation of evidence for the impact of climate change and especially glaciation on the geosphere, particularly in terms of its implications for: the distribution and stability of stress regimes, groundwater flux and flow patterns, groundwater chemistry, and thermal conditions. This workshop was intended to promote informal scientific discussion and the exchange of information and ideas between a wide range of disciplines such as climatology, glaciology, hydrology, hydrochemistry, rock mechanics and structural geology. Participants from outside the radioactive waste community were welcome. Of particular need were palaeosignatures, direct observational information and models of the impact of continental ice sheets and periglacial conditions on crystalline bedrock. The workshop has highlighted the fact that there is a great deal of interest in the area of climate change and its impact on the performance of a deep geological repository, but that there are still many issues remaining that require further resolution. The first half of these proceedings gives overviews of the discussions and conclusions from the different sessions at the workshop, as well as the general conclusion and summary. In the second half, summaries of 49 contributions to the workshop are printed. These summaries have been indexed separately

  4. Proceedings from glaciation and hydrogeology. Workshop on the impact of climate change and glaciations on rock stresses, groundwater flow and hydrochemistry - Past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    King-Clayton, L.; Chapman, N. [eds.] [QuantiSci Ltd (United Kingdom); Ericsson, L.O. [ed.] [SKB, Stockholm (Sweden); Kautsky, F. [ed.] [SKI, Stockholm (Sweden)

    1997-04-01

    Assessment of the long term safety of radioactive waste disposal requires assimilation of evidence for the impact of climate change and especially glaciation on the geosphere, particularly in terms of its implications for: the distribution and stability of stress regimes, groundwater flux and flow patterns, groundwater chemistry, and thermal conditions. This workshop was intended to promote informal scientific discussion and the exchange of information and ideas between a wide range of disciplines such as climatology, glaciology, hydrology, hydrochemistry, rock mechanics and structural geology. Participants from outside the radioactive waste community were welcome. Of particular need were palaeosignatures, direct observational information and models of the impact of continental ice sheets and periglacial conditions on crystalline bedrock. The workshop has highlighted the fact that there is a great deal of interest in the area of climate change and its impact on the performance of a deep geological repository, but that there are still many issues remaining that require further resolution. The first half of these proceedings gives overviews of the discussions and conclusions from the different sessions at the workshop, as well as the general conclusion and summary. In the second half, summaries of 49 contributions to the workshop are printed. These summaries have been indexed separately.

  5. Edge of polar cap patches

    Science.gov (United States)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2016-04-01

    On the night of 4 December 2013, a sequence of polar cap patches was captured by an all-sky airglow imager (ASI) in Longyearbyen, Norway (78.1°N, 15.5°E). The 630.0 nm airglow images from the ASI of 4 second exposure time, oversampled the emission of natural lifetime (with quenching) of at least ˜30 sec, introduce no observational blurring effects. By using such high-quality ASI images, we succeeded in visualizing an asymmetry in the gradients between the leading/trailing edges of the patches in a 2-D fashion. The gradient in the leading edge was found to be 2-3 times steeper than that in the trailing edge. We also identified fingerlike structures, appearing only along the trailing edge of the patches, whose horizontal scale size ranged from 55 to 210 km. These fingers are considered to be manifestations of plasma structuring through the gradient-drift instability (GDI), which is known to occur only along the trailing edge of patches. That is, the current 2-D observations visualized, for the first time, how GDI stirs the patch plasma and such a mixing process makes the trailing edge more gradual. This result strongly implies a close connection between the GDI-driven plasma stirring and the asymmetry in the large-scale shape of patches and then suggests that the fingerlike structures can be used as markers to estimate the fine-scale structure in the plasma flow within patches.

  6. Genetic ablation of root cap cells in Arabidopsis

    OpenAIRE

    Tsugeki, Ryuji; Fedoroff, Nina V.

    1999-01-01

    The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of...

  7. Medical Malpractice Damage Caps and Provider Reimbursement.

    Science.gov (United States)

    Friedson, Andrew I

    2017-01-01

    A common state legislative maneuver to combat rising healthcare costs is to reform the tort system by implementing caps on noneconomic damages awardable in medical malpractice cases. Using the implementation of caps in several states and large database of private insurance claims, I estimate the effect of damage caps on the amount providers charge to insurance companies as well as the amount that insurance companies reimburse providers for medical services. The amount providers charge insurers is unresponsive to tort reform, but the amount that insurers reimburse providers decreases for some procedures. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. The pharmaceutical vial capping process: Container closure systems, capping equipment, regulatory framework, and seal quality tests.

    Science.gov (United States)

    Mathaes, Roman; Mahler, Hanns-Christian; Buettiker, Jean-Pierre; Roehl, Holger; Lam, Philippe; Brown, Helen; Luemkemann, Joerg; Adler, Michael; Huwyler, Joerg; Streubel, Alexander; Mohl, Silke

    2016-02-01

    Parenteral drug products are protected by appropriate primary packaging to protect against environmental factors, including potential microbial contamination during shelf life duration. The most commonly used CCS configuration for parenteral drug products is the glass vial, sealed with a rubber stopper and an aluminum crimp cap. In combination with an adequately designed and controlled aseptic fill/finish processes, a well-designed and characterized capping process is indispensable to ensure product quality and integrity and to minimize rejections during the manufacturing process. In this review, the health authority requirements and expectations related to container closure system quality and container closure integrity are summarized. The pharmaceutical vial, the rubber stopper, and the crimp cap are described. Different capping techniques are critically compared: The most common capping equipment with a rotating capping plate produces the lowest amount of particle. The strength and challenges of methods to control the capping process are discussed. The residual seal force method can characterize the capping process independent of the used capping equipment or CCS. We analyze the root causes of several cosmetic defects associated with the vial capping process. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Reconstructing the groundwater flow in the Baltic Basin during the Last glaciation

    Science.gov (United States)

    Saks, T.; Sennikovs, J.; Timuhins, A.; Kalvāns, A.

    2012-04-01

    In last decades it has been discussed that most large ice sheets tend to reside on warm beds even in harsh clima tic conditions and subglacial melting occurs due to geothermal heat flow and deformation heat of the ice flow. However the subglacial groundwater recharge and flow conditions have been addressed in only few studies. The aim of this study is to establish the groundwater flow pattern in the Baltic Basin below the Scandinavian ice sheet during the Late Weichselian glaciation. The calculation results are compared to the known distribution of the groundwater body of the glacial origin found in Cambrian - Vendian (Cm-V) aquifer in the Northern Estonia which is believed to have originated as a result of subglacial meltwater infiltration during the reoccurring glaciations. Steady state regional groundwater flow model of the Baltic Basin was used to simulate the groundwater flow beneath the ice sheet with its geometry adjusted to reflect the subglacial topography. Ice thickness modelling data (Argus&Peltier, 2010) was used for the setup of the boundary conditions: the meltwater pressure at the ice bed was assumed equal to the overlying ice mass. The modelling results suggest two main recharge areas of the Cm-V aquifer system, and reversed groundwater flow that persisted for at least 14 thousand years. Model results show that the groundwater flow velocities in the Cm-V aquifer in the recharge area in N-Estonia beneath the ice sheet exceeded the present velocities by a factor of 10 on average. The calculated meltwater volume recharged into the Cm-V aquifer system during the Late Weichselian corresponds roughly to the estimated, however, considering the fact, that the study area has been glaciated at least 4 times this is an overestimation. The modeling results attest the hypothesis of light dO18 groundwater glacial origin in the Cm-V aquifer system, however the volumes, timing and processes involved in the meltwater intrusion are yet to be explored. This study was

  10. A 565 Ma old glaciation in the Ediacaran of peri-Gondwanan West Africa

    Science.gov (United States)

    Linnemann, Ulf; Pidal, Agustín Pieren; Hofmann, Mandy; Drost, Kerstin; Quesada, Cecilio; Gerdes, Axel; Marko, Linda; Gärtner, Andreas; Zieger, Johannes; Ulrich, Jens; Krause, Rita; Vickers-Rich, Patricia; Horak, Jana

    2018-04-01

    In the Cadomian orogen of the NE Bohemian Massif and of SW Iberia, a post-Gaskiers glacial event dated at c. 565 Ma has been detected. Such Ediacaran-aged glaciomarine deposits occur in the Weesenstein and Clanzschwitz groups of the Saxo-Thuringian zone (Bohemia) and in the Lower Alcudian group of the southern Central Iberian zone (Iberia). Both areas are parts of Cadomia situated in the Western and Central European Variscides. Glaciomarine sedimentary rocks are characterized by such features as dropstones, flat iron-shaped pebbles (" Bügeleisen- Geschiebe"), facetted pebbles, dreikanters, and zircon grains affected by ice abrasion. For age and provenance determination, LA-ICP-MS U-Pb ages ( n = 1124) and Hf isotope ( n = 446) analyses were performed. The maximum age of the glaciomarine deposits within a Cadomian back-arc basin based on U-Pb analytics resulted in the youngest detrital zircon populations showing ages of 562-565 Ma and of c. 566-576 Ma old zircon derived from granitoid pebbles within the diamictites. The youngest age recorded was 538-540 Ma based on zircon from the plutons which had intruded the previously deformed Ediacaran metasedimentary rocks. Previously described glaciomarine diamictites of Cadomia (Weesenstein, Clanzschwitz, and Orellana diamictites) are most definitely younger than the c. 579-581 Ma Gaskiers glaciation in Newfoundland (Gaskiers) and in SE New England (Squantum). We propose the term Weesenstein- Orellana glaciation for this new Ediacaran glacial event, named after the most relevant regions of exposure. Palaeogeographically, these glaciomarine diamictites and related sedimentary deposits lie on the periphery of the West African Craton (western peri-Gondwana), and evidence has been provided by detrital zircon U-Pb ages and their Hf isotope composition. Correlation with similar glaciomarine deposits in the Anti-Atlas (Bou Azzer) and Saudi Arabia suggests a continued distribution of post-Gaskiers glacial deposits along the

  11. Mapping of p140Cap phosphorylation sites

    DEFF Research Database (Denmark)

    Repetto, Daniele; Aramu, Simona; Boeri Erba, Elisabetta

    2013-01-01

    Protein phosphorylation tightly regulates specific binding of effector proteins that control many diverse biological functions of cells (e. g. signaling, migration and proliferation). p140Cap is an adaptor protein, specifically expressed in brain, testis and epithelial cells, that undergoes...

  12. Recessed floating pier caps for highway bridges.

    Science.gov (United States)

    1973-01-01

    Presented are alternate designs for two existing bridges in Virginia - one with steel beams and the other with prestressed concrete beams - whereby the pier caps are recessed within the depth of the longitudinal beams. The purpose of this recession i...

  13. Circumpolar Active-Layer Permafrost System (CAPS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Circumpolar Active-Layer Permafrost System (CAPS) contains over 100 data sets pertaining to permafrost and frozen ground topics. It also contains detailed...

  14. The ATLAS TRT end-cap detectors

    Science.gov (United States)

    ATLAS TRT Collaboration; Abat, E.; Addy, T. N.; Åkesson, T. P. A.; Alison, J.; Anghinolfi, F.; Arik, E.; Arik, M.; Atoian, G.; Auerbach, B.; Baker, O. K.; Banas, E.; Baron, S.; Bault, C.; Becerici, N.; Beddall, A.; Beddall, A. J.; Bendotti, J.; Benjamin, D. P.; Bertelsen, H.; Bingul, A.; Blampey, H.; Bocci, A.; Bochenek, M.; Bondarenko, V. G.; Bychkov, V.; Callahan, J.; Capeáns Garrido, M.; Cardiel Sas, L.; Catinaccio, A.; Cetin, S. A.; Chandler, T.; Chritin, R.; Cwetanski, P.; Dam, M.; Danielsson, H.; Danilevich, E.; David, E.; Degenhardt, J.; Di Girolamo, B.; Dittus, F.; Dixon, N.; Dobos, D.; Dogan, O. B.; Dolgoshein, B. A.; Dressnandt, N.; Driouchi, C.; Ebenstein, W. L.; Eerola, P.; Egede, U.; Egorov, K.; Evans, H.; Farthouat, P.; Fedin, O. L.; Fowler, A. J.; Fratina, S.; Froidevaux, D.; Fry, A.; Gagnon, P.; Gavrilenko, I. L.; Gay, C.; Ghodbane, N.; Godlewski, J.; Goulette, M.; Gousakov, I.; Grigalashvili, N.; Grishkevich, Y.; Grognuz, J.; Hajduk, Z.; Hance, M.; Hansen, F.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hare, G. A.; Harvey, A., Jr.; Hauviller, C.; High, A.; Hulsbergen, W.; Huta, W.; Issakov, V.; Istin, S.; Jain, V.; Jarlskog, G.; Jeanty, L.; Kantserov, V. A.; Kaplan, B.; Kapliy, A. S.; Katounine, S.; Kayumov, F.; Keener, P. T.; Kekelidze, G. D.; Khabarova, E.; Khristachev, A.; Kisielewski, B.; Kittelmann, T. H.; Kline, C.; Klinkby, E. B.; Klopov, N. V.; Ko, B. R.; Koffas, T.; Kondratieva, N. V.; Konovalov, S. P.; Koperny, S.; Korsmo, H.; Kovalenko, S.; Kowalski, T. Z.; Krüger, K.; Kramarenko, V.; Kudin, L. G.; LeBihan, A.-C.; LeGeyt, B. C.; Levterov, K.; Lichard, P.; Lindahl, A.; Lisan, V.; Lobastov, S.; Loginov, A.; Loh, C. W.; Lokwitz, S.; Long, M. C.; Lucas, S.; Lucotte, A.; Luehring, F.; Lundberg, B.; Mackeprang, R.; Maleev, V. P.; Manara, A.; Mandl, M.; Martin, A. J.; Martin, F. F.; Mashinistov, R.; Mayers, G. M.; McFarlane, K. W.; Mialkovski, V.; Mills, B. M.; Mindur, B.; Mitsou, V. A.; Mjörnmark, J. U.; Morozov, S. V.; Morris, E.; Mouraviev, S. V.; Muir, A. M.; Munar, A.; Nadtochi, A. V.; Nesterov, S. Y.; Newcomer, F. M.; Nikitin, N.; Novgorodova, O.; Novodvorski, E. G.; Ogren, H.; Oh, S. H.; Oleshko, S. B.; Olivito, D.; Olszowska, J.; Ostrowicz, W.; Passmore, M. S.; Patrichev, S.; Penwell, J.; Perez-Gomez, F.; Peshekhonov, V. D.; Petersen, T. C.; Petti, R.; Placci, A.; Poblaguev, A.; Pons, X.; Price, M. J.; hne, O. Rø; Reece, R. D.; Reilly, M. B.; Rembser, C.; Romaniouk, A.; Rousseau, D.; Rust, D.; Ryabov, Y. F.; Ryjov, V.; Söderberg, M.; Savenkov, A.; Saxon, J.; Scandurra, M.; Schegelsky, V. A.; Scherzer, M. I.; Schmidt, M. P.; Schmitt, C.; Sedykh, E.; Seliverstov, D. M.; Shin, T.; Shmeleva, A.; Sivoklokov, S.; Smirnov, S. Yu; Smirnova, L.; Smirnova, O.; Smith, P.; Sosnovtsev, V. V.; Sprachmann, G.; Subramania, S.; Suchkov, S. I.; Sulin, V. V.; Szczygiel, R. R.; Tartarelli, G.; Thomson, E.; Tikhomirov, V. O.; Tipton, P.; Valls Ferrer, J. A.; Van Berg, R.; Vassilakopoulos, V. I.; Vassilieva, L.; Wagner, P.; Wall, R.; Wang, C.; Whittington, D.; Williams, H. H.; Zhelezko, A.; Zhukov, K.

    2008-10-01

    The ATLAS TRT end-cap is a tracking drift chamber using 245,760 individual tubular drift tubes. It is a part of the TRT tracker which consist of the barrel and two end-caps. The TRT end-caps cover the forward and backward pseudo-rapidity region 1.0 < |η| < 2.0, while the TRT barrel central η region |η| < 1.0. The TRT system provides a combination of continuous tracking with many measurements in individual drift tubes (or straws) and of electron identification based on transition radiation from fibers or foils interleaved between the straws themselves. Along with other two sub-system, namely the Pixel detector and Semi Conductor Tracker (SCT), the TRT constitutes the ATLAS Inner Detector. This paper describes the recently completed and installed TRT end-cap detectors, their design, assembly, integration and the acceptance tests applied during the construction.

  15. The role of sub-milankovitch climatic forcing in the initiation of the northern hemisphere glaciation

    Science.gov (United States)

    Willis; Kleczkowski; Briggs; Gilligan

    1999-07-23

    Mechanisms responsible for the initiation of major glaciation in the Northern Hemisphere at about 2.75 million years ago are poorly understood. A laminated terrestrial sequence from Pula maar, Hungary, containing about 320,000 years in annual layers between 3.05 and 2. 60 million years ago, provides a detailed record of rates of climatic change across this dramatic transition. An analysis of the record implies that climatic variations at sub-Milankovitch frequencies (less than or equal to 15,000 years) were an important driving force during this transitional interval and that, as the threshold was approached, these increased in frequency and amplitude, possibly providing the final trigger for the amplification of Northern Hemisphere ice sheets.

  16. Quaternary sediment thickness and bedrock topography of the glaciated United States east of the Rocky Mountains

    Science.gov (United States)

    Soller, David R.; Garrity, Christopher P.

    2018-01-26

    Beginning roughly 2.6 million years ago, global climate entered a cooling phase known as the Pleistocene Epoch. As snow in northern latitudes compacted into ice several kilometers thick, it flowed as glaciers southward across the North American continent. These glaciers extended across the northern United States, dramatically altering the landscape they covered. East of the Rocky Mountains, the ice coalesced into continental glaciers (called the Laurentide Ice Sheet) that at times blanketed much of the north-central and northeastern United States. To the west of the Laurentide Ice Sheet, glaciers formed in the mountains of western Canada and the United States and coalesced into the Cordilleran ice sheet; this relatively smaller ice mass extended into the conterminous United States in the northernmost areas of western Montana, Idaho, and Washington. Throughout the Pleistocene, landscape alteration occurred by (1) glacial erosion of the rocks and sediments; (2) redeposition of the eroded earth materials in a form substantially different from their source rocks, in terms of texture and overall character; and (3) disruption of preexisting drainage patterns by the newly deposited sediments. In many cases, pre-glacial drainage systems (including, for example, the Mississippi River) were rerouted because their older drainage courses became blocked with glacial sediment.The continental glaciers advanced and retreated many times across those areas. During each ice advance, or glaciation, erosion and deposition occurred, and the landscape was again altered. Through successive glaciations, the landscape and the bedrock surface gradually came to resemble their present configurations. As continental ice sheets receded and the Pleistocene ended, erosion and deposition of sediment (for example in stream valleys) continued to shape the landscape up to the present day (albeit to a lesser extent than during glaciation). The interval of time since the last recession of the glaciers

  17. Meltwater channel scars and the extent of Mid-Pleistocene glaciation in central Pennsylvania

    Science.gov (United States)

    Marsh, Ben

    2017-10-01

    High-resolution digital topographic data permit morphological analyses of glacial processes in detail that was previously infeasible. High-level glaciofluvial erosional scars in central Pennsylvania, identified and delimited using LiDAR data, define the approximate ice depth during a pre-Wisconsin advance, > 770,000 BP, on a landscape unaffected by Wisconsin glaciation. Distinctive scars on the prows of anticlinal ridges at 175-350 m above the valley floor locate the levels of subice meltwater channels. A two-component planar GIS model of the ice surface is derived using these features and intersected with a digital model of contemporary topography to create a glacial limit map. The map is compared to published maps, demonstrating the limits of conventional sediment-based mapping. Additional distinctive meltwater features that were cut during deglaciation are modeled in a similar fashion.

  18. Corrective action program (CAP) in United States

    International Nuclear Information System (INIS)

    Okamoto, Koji; Kobayashi, Masahide

    2008-01-01

    The Corrective Action Process (CAP) is one of the most important key issues on the Nuclear Reactor Safety. The experiences on the nuclear power plant operations, including safety culture, maintenance, and so on, should be continuously evaluated and influenced to the KAIZEN (improvement) of the NPP operations. The review of the CAP system in US will be useful for the NPP safety in Japan. (author)

  19. Application of Radiocarbon Dating for Mapping of the Limits of the Last Glaciation (Nemunas, Weichselian) in South-East Lithuania

    International Nuclear Information System (INIS)

    Gaigalas, A.

    1996-01-01

    The recent research of certain sites located in the Medininkai Highland have provided significant data for mapping up the limits of the last Glaciation in South-East Lithuania. The Medininkai Highland has been formed in conditions of active advances of the ice of Ashmena glacial lobe and consists of several corner type morainic massifs which are joined by belts of terminal moraines stretching from North-West to South-East (Fig. 1). The location of the limits of Last Glaciation depends essentially on the age of glacial deposits forming the topography of the Medininkai Highland. Attempts to establish the limits of the Last Glaciation were made by using complex methods in scope of a mapping project in scale 1:50000. In this article the data received from radiocarbon dating of Section 117A are presented. Radiocarbon dating is of exclusive importance for substantiating the location of the limits of the maximum advance of the Nemunas (Weichselian) continental ice in South-East Lithuania. The significance of the problem is made obvious by suppositions that the Last Glaciation has covered all Medininkai Highland. Radiocarbon dating have confirmed the conclusions received by palynological research that until the topography of Medininkai Highland evolved in the present kettle holes and lowlands in the central part of this highland there were deposits accumulated of the Holocene, Late Middle and Early Nemunas and Merkine Interglacial periods. 18 refs., 2 figs., 1 tab

  20. Silicate Weathering and Carbon Cycle Controls on the Oligocene-Miocene Transition Glaciation

    Science.gov (United States)

    Stewart, Joseph A.; James, Rachael H.; Anand, Pallavi; Wilson, Paul A.

    2017-10-01

    Changes in both silicate weathering rates and organic carbon burial have been proposed as drivers of the transient "Mi-1" glaciation event at the Oligocene-Miocene transition (OMT; 23 Ma). However, detailed geochemical proxy data are required to test these hypotheses. Here we present records of Li/Ca, Mg/Ca, Cd/Ca, U/Ca, δ18O, δ13C, and shell weight in planktonic foraminifera from marine sediments spanning the OMT in the equatorial Atlantic Ocean. Li/Ca values increase by 1 μmol/mol across this interval. We interpret this to indicate an 20% increase in silicate weathering rates, which would have lowered atmospheric CO2, potentially forcing the Antarctic glaciation 23 Ma. δ13C of thermocline dwelling planktonic foraminifera track the global increase in seawater δ13C across the OMT and during the Mi-1 event, hence supporting a hypothesized global increase in organic carbon burial rates. High δ13C previously measured in epipelagic planktonic foraminifera and high Cd/Ca ratios during Mi-1 are interpreted to represent locally enhanced primary productivity, stimulated by increased nutrients supply to surface waters. The fingerprint of high export production and associated organic carbon burial at this site is found in reduced bottom water oxygenation (inferred from high foraminiferal U/Ca) and enhanced respiratory dissolution of carbonates, characterized by reduced foraminiferal shell weight. Replication of our results elsewhere would strengthen the case that weathering-induced CO2 sequestration preconditioned climate for Antarctic ice sheet growth across the OMT, and increased burial of organic carbon acted as a feedback that intensified cooling at this time.

  1. Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters

    Science.gov (United States)

    Kubo, Joshua S.; Torgersen, Christian E.; Bolton, Susan M.; Weekes, Anne A.; Gara, Robert I.

    2013-01-01

    1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in relict glaciated subalpine basins in Mt. Rainier National Park, Washington, USA. 2. Aquatic insects were collected during summer and autumn in three headwater basins. In each basin, three different stream segment types were sampled: colluvial groundwater sources, alluvial lake inlets, and cascade-bedrock lake outlets. Ward's hierarchical cluster analysis revealed high β diversity in aquatic insect assemblages, and non-metric multidimensional scaling indicated that spatial and temporal patterns in assemblage composition differed among headwater stream segment types. Aquatic insect assemblages showed more fidelity to stream segment types than to individual basins, and the principal environmental variables associated with assemblage structure were temperature and substrate. 3. Indicator species analyses identified specific aquatic insects associated with each stream segment type. Several rare and potentially endemic aquatic insect taxa were present, including the recently described species, Lednia borealis (Baumann and Kondratieff). 4. Our results indicate that aquatic insect assemblages in relict glaciated subalpine headwaters were strongly differentiated among stream segment types. These results illustrate the contribution of headwaters to riverine biodiversity and emphasise the importance of these habitats for monitoring biotic responses to climate change. Monitoring biotic assemblages in high-elevation headwaters is needed to prevent the potential loss of unique and sensitive biota.

  2. Final closure of the Panamaian Isthmus and the onset of northern hemisphere glaciation

    Science.gov (United States)

    Sarnthein, M.; Bartoli, G.; Weinelt, M.; Erlenkeuser, H.; Garbe-Schoenberg, D.; Lea, D. W.

    2005-12-01

    The Greenland ice sheet forms a key factor controlling the Quaternary-style glacial scenario. However, origin and mechanisms of major Arctic glaciation starting at 3.15 Ma and culminating at 2.74 Ma have remained controversial. For this phase of intense cooling Ravelo et al. (2004) proposed a complex gradual forcing mechanism. In contrast, our new submillennial-scale paleoceanographic records from the Pliocene North Atlantic suggest a far more precise timing and forcing for the initiation of northern hemisphere glaciation (NHG), since it was linked to a 2-3 /degC surface water warming during warm stages from 2.95 to 2.82 Ma (until glacial stage G10). These records support previous models (Haug and Tiedemann, 1998) claiming that the final closure of the Panama Isthmus (3.0 - ~2.5 Ma; Groeneveld, 2005) induced an increased poleward salt and heat transport. Associated strengthening of North Atlantic thermohaline circulation and in turn, an intensified moisture supply to northern high latitudes resulted in the build-up of NHG, finally culminating in the great, irreversible climate crash at glacial stage G6 (2.74 Ma). In summary, we see a two-step threshold mechanism that marked the onset of NHG with glacial-to-interglacial cycles quasi-persistent until today. G r o e n e v e l d, J., The final closure of the Central American Seaway. PhD Thesis Kiel, 2005. H a u g, G. and T i e d e m a n n , R., 1 9 9 8. Nature 393, 676-678. R a v e l o , A.C., e t a l ., 2004. Nature 429, 263-267.

  3. Controls on the distribution of channel reach morphology in selectively glaciated catchments

    Science.gov (United States)

    Addy, S.; Soulsby, C.; Hartley, A. J.

    2014-04-01

    To assess the controls on the distribution of channel reach morphology in a selectively glaciated landscape, we used field mapping and a geographical information system (GIS) in the River Dee catchment, northeast Scotland. Controls on channel morphology were investigated using (1) continuous longitudinal assessment of channel morphology distribution in relation to geology, glacial history, topography, and total stream power (Ω) in two subcatchments, and (2) slope (S), Ω, and a slope-drainage area (S-A) framework to understand the occurrence of 173 widely distributed bedrock, mixed bedrock-alluvial, and alluvial (three different types) reaches. The S-A framework used indicators of transport capacity (Qc) and sediment supply (Qs) to differentiate channel types. The study highlights the disjointed nature of channel reach distribution at the river scale that reflects variable lithology and glacial modification. Because of the subdued topography in contrast to other regions, colluvial forcing of channel morphology in the headwaters was lacking. However, in common with other glaciated landscapes, repeated sequences of channel reach type progression determined by valley steps were evident. The S-A analysis successfully discriminated 87.2% of alluvial and 91.4% of bedrock reaches despite the variable land use and glacial modification. Discrimination of the full range of channel types using S, Ω, or the S-A framework was poor however. Notably, a third of the transport alluvial reaches were located in the bedrock S-A domain, and the majority of mixed reaches were widely distributed mostly within the bedrock domain and not close to the critical slope (Sc). In comparison to other regions, the Sc above which Qc > Qs and bedrock reaches dominate, was notably higher. We hypothesise that a drier climate and the higher entrainment threshold of coarse, granite-dominated bed materials create a higher Sc.

  4. A nucleation theory of cell surface capping

    International Nuclear Information System (INIS)

    Coutsias, E.A.; Wester, M.J.; Perelson, A.S.

    1997-01-01

    We propose a new theory of cell surface capping based on the principles of nucleation. When antibody interacts with cell surface molecules, the molecules initially form small aggregates called patches that later coalesce into a large aggregate called a cap. While a cap can form by patches being pulled together by action of the cell''s cytoskeleton, in the case of some molecules, disruption of the cytoskeleton does not prevent cap formation. Diffusion of large aggregates on a cell surface is slow, and thus we propose that a cap can form solely through the diffusion of small aggregates containing just one or a few cell surface molecules. Here we consider the extreme case in which single molecules are mobile, but aggregates of all larger sizes are immobile. We show that a set of patches in equilibrium with a open-quotes seaclose quotes of free cell surface molecules can undergo a nucleation-type phase transition in which the largest patch will bind free cell surface molecules, deplete the concentration of such molecules in the open-quotes seaclose quotes and thus cause the other patches to shrink in size. We therefore show that a cap can form without patches having to move, collide with each other, and aggregate

  5. Study of Mechanisms of Aerosol Indirect Effects on Glaciated Clouds: Progress during the Project Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-10-18

    This 3-year project has studied how aerosol pollution influences glaciated clouds. The tool applied has been an 'aerosol-cloud model'. It is a type of Cloud-System Resolving Model (CSRM) modified to include 2-moment bulk microphysics and 7 aerosol species, as described by Phillips et al. (2009, 2013). The study has been done by, first, improving the model and then performing sensitivity studies with validated simulations of a couple of observed cases from ARM. These are namely the Tropical Warm Pool International Cloud Experiment (TWP-ICE) over the tropical west Pacific and the Cloud and Land Surface Interaction Campaign (CLASIC) over Oklahoma. During the project, sensitivity tests with the model showed that in continental clouds, extra liquid aerosols (soluble aerosol material) from pollution inhibited warm rain processes for precipitation production. This promoted homogeneous freezing of cloud droplets and aerosols. Mass and number concentrations of cloud-ice particles were boosted. The mean sizes of cloud-ice particles were reduced by the pollution. Hence, the lifetime of glaciated clouds, especially ice-only clouds, was augmented due to inhibition of sedimentation and ice-ice aggregation. Latent heat released from extra homogeneous freezing invigorated convective updrafts, and raised their maximum cloud-tops, when aerosol pollution was included. In the particular cases simulated in the project, the aerosol indirect effect of glaciated clouds was twice than of (warm) water clouds. This was because glaciated clouds are higher in the troposphere than water clouds and have the first interaction with incoming solar radiation. Ice-only clouds caused solar cooling by becoming more extensive as a result of aerosol pollution. This 'lifetime indirect effect' of ice-only clouds was due to higher numbers of homogeneously nucleated ice crystals causing a reduction in their mean size, slowing the ice-crystal process of snow production and slowing

  6. A thermoelectric cap for seafloor hydrothermal vents

    International Nuclear Information System (INIS)

    Xie, Yu; Wu, Shi-jun; Yang, Can-jun

    2016-01-01

    Highlights: • We developed a thermoelectric cap (TC) to harvest hydrothermal energy. • The TC was deployed at a hydrothermal vent site near Kueishantao islet, Taiwan. • The TC monitored the temperature of the hydrothermal fluids during the field test. • The TC could make the thermal energy of hydrothermal fluids a viable power source. - Abstract: Long-term in situ monitoring is crucial to seafloor scientific investigations. One of the challenges of operating sensors in seabed is the lifespan of the sensors. Such sensors are commonly powered by batteries when other alternatives, such as tidal or solar energy, are unavailable. However, the batteries have a limited lifespan and must be recharged or replaced periodically, which is costly and impractical. A thermoelectric cap, which harvests the thermal energy of hydrothermal fluids through a conduction pipe and converts the heat to electrical energy by using thermoelectric generators, was developed to avoid these inconveniences. The thermoelectric cap was combined with a power and temperature measurement system that enables the thermoelectric cap to power a light-emitting diode lamp, an electronic load (60 Ω), and 16 thermocouples continuously. The thermoelectric cap was field tested at a shallow hydrothermal vent site near Kueishantao islet, which is located offshore of northeastern Taiwan. By using the thermal gradient between hydrothermal fluids and seawater, the thermoelectric cap obtained a sustained power of 0.2–0.5 W during the field test. The thermoelectric cap successfully powered the 16 thermocouples and recorded the temperature of the hydrothermal fluids during the entire field test. Our results show that the thermal energy of hydrothermal fluids can be an alternative renewable power source for oceanographic research.

  7. 75 FR 49527 - Caps Visual Communications, LLC; Black Dot Group; Formerly Known as Caps Group Acquisition, LLC...

    Science.gov (United States)

    2010-08-13

    ... Employment and Training Administration Caps Visual Communications, LLC; Black Dot Group; Formerly Known as... Adjustment Assistance on June 24, 2010, applicable to workers of Caps Visual Communications, LLC, Black Dot..., Caps Visual Communications, LLC, Black Dot Group, formerly known as Caps Group Acquisition, LLC...

  8. Relation between the occurence of major glaciations of Antarctica and Greenland and the atmospheric CO2: a modelling approach

    Science.gov (United States)

    Bonelli, S.; Ramstein, G.; Donnadieu, Y.; Dumas, C.; Ritz, C.; Waldman, R.

    2009-12-01

    The main purpose of the studies presented here is to investigate the relationship between the occurrence of major glaciations of Antarctica and Greenland and the atmospheric CO_2 through modelling approach. We use a Climate Model of Intermediate Complexity^1 coupled with two ice sheet models GRISLI^2 for Antarctica ice sheet and GREMLINS^3 for Greenland. Our study focuses on the two extremities of Cenozoic(Palaeocene / Eocene glaciation of Antarctica 34My BP) and Pliocene (3My) glaciation of Greenland. Using such a tool enable to explore the different forcing factors (CO_2 , insolation, tectonics) and more interestingly to capture the CO2 threshold that corresponds to ice sheet build-up. Our results compare well with CO_2 reconstructions for instance from Pagani M., 2005^4 for Paleocene / Eocene and with Kürschner, W.^5 for glaciation of Greenland. Moreover, these results^6 are in good agreement with previous studies of Antarctica glaciation^7,8, and with the recent study of D. Lunt^9 for Greenland. Major finding is that CO_2 decrease is indeed the basic tempo for explaining ice sheet, but the real value of CO_2 which will trigger the onset of glaciation are deeply modulated by changes in paleogeography, tectonic, ocean dynamics and insolation. 1. Bonelli S., Charbit S., Kageyama M., Woillez M.N., Ramstein G., Dumas C., Quiquet A., 2009. Investigating the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle.Clim. Past 5, 329-345 2. Ritz, C., Rommelaere, V., and Dumas, C.: Modeling the evolution of Antarctic ice sheet over the last 420,000 years: Implications for altitude changes in the Vostok region, J. Geophys. Res.-Atmos., 106(D23), 31943¿31964, 2001 3. Ritz, C., Fabre, A., and Letreguilly, A.: Sensitivity of a Greenland ice sheet model to ice flow and ablation parameters: consequences for the evolution through the last climatic cycle, Clim. Dynam., (13), 11¿24, 1997. 4. Pagani, M., J. C. Zachos, et al. (2005). "Marked

  9. Catastrophic antiphospholipid syndrome (CAPS): Descriptive analysis of 500 patients from the International CAPS Registry.

    Science.gov (United States)

    Rodríguez-Pintó, Ignasi; Moitinho, Marta; Santacreu, Irene; Shoenfeld, Yehuda; Erkan, Doruk; Espinosa, Gerard; Cervera, Ricard

    2016-12-01

    To analyze the clinical and immunologic manifestations of patients with catastrophic antiphospholipid syndrome (CAPS) from the "CAPS Registry". The demographic, clinical and serological features of 500 patients included in the website-based "CAPS Registry" were analyzed. Frequency distribution and measures of central tendency were used to describe the cohort. Comparison between groups regarding qualitative variables was undertaken by chi-square or Fisher exact test while T-test for independent variables was used to compare groups regarding continuous variables. 500 patients (female: 343 [69%]; mean age 38±17) accounting for 522 episodes of CAPS were included in the analysis. Forty percent of patients had an associated autoimmune disease, mainly systemic lupus erythematosus (SLE) (75%). The majority of CAPS episodes were triggered by a precipitating factor (65%), mostly infections (49%). Clinically, CAPS was characterized by several organ involvement affecting kidneys (73%), lungs (60%), brain (56%), heart (50%), and skin (47%). Lupus anticoagulant, IgG anticardiolipin and IgG anti-β2-glycprotein antibodies were the most often implicated antiphospholipid antibodies (83%, 81% and 78% respectively). Mortality accounted for 37% of episodes of CAPS. Several clinical differences could be observed based on the age of presentation and its association to SLE. Those cases triggered by a malignancy tended to occur in older patients, while CAPS episodes in young patients were associated with an infectious trigger and peripheral vessels involvement. Additionally, CAPS associated with SLE were more likely to have severe cardiac and brain involvement leading to a higher mortality (48%). Although the presentation of CAPS is characterized by multiorgan thrombosis and failure, clinical differences among patients exist based on age and underlying chronic diseases, e.g. malignancy and SLE. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Current glaciation of the Chikhachev ridge (South-Eastern Altai and its dynamics after maximum of the Little Ice Age

    Directory of Open Access Journals (Sweden)

    D. A. Ganyushkin

    2016-01-01

    Full Text Available Glaciation of the Chikhachev ridge (South-Eastern Altai remains poorly known: field observations were not performed since the mid-twentieth century, available schemes and estimates of the glaciation and its scale made on the basis of remote sensing cover only a part of the glaciers, reconstructions of the Little Ice Age (LIA glaciations are absent. This research was based on interpretation of the satellite images: Landsat-4 (1989, Landsat-7 (2001, and Spot-5 (2011, as well as with the use of data of the field season of 2015. Characteristics of glaciations of the Chikhachev ridge as the whole and of its individual centers (Talduair massif, Mongun-Taiga-Minor massif, and southern part of the Chikhachev ridge were determined for the first time. Recent glaciation is represented by 7 glaciers with their total area of 1.12 km2 in the Talduair massif, by 5 glaciers with total area of 0.75 km2 in the Mongun-Taiga-Minor massif, and by 85 glaciers with total area of 29 km2 in the southern part of the Chikhachev ridge. Since the LIA maximum, areas of glaciers decreased by 61% in the Talduair massif, by 74% in the Mongun-Taiga-Minor massif, by 56% in the southern part of the Chikhachev ridge with simultaneous lifting of the firn line by 50 m, 65 m, and 70 m, respectively.The largest rates of the glacier contractions were determined for the period 1989–2011. Different mechanisms of the glacier retreats were shown by the example of the glacier complexes Burgastyn-Gol (one-sided retreat and disintegration and the Grigorjev glacier (gradual retreat of the tongue. Retreat of the Grigorjev glacier has been reconstructed for the period from the LIA maximum until 2015. Average rate of the retreat increased from 1,6 m/year in 1957–1989 up to 11,3 m/year in 2011–2015. The present-day scales of the glaciers and rates of their retreating do not significantly differ from estimations made by other researchers for the nearest centers of glaciation of the

  11. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...... as a strong ice wave. The ice cap leads to low transmission of energy into the crust such that charges need be larger than in conventional onshore experiments to obtain reliable seismic signals. The strong reflection coefficient at the base of the ice generates strong multiples which may mask for secondary...... phases. This effect may be crucial for acquisition of reflection seismic profiles on ice caps. Our experience shows that it is essential to use optimum depth for the charges and to seal the boreholes carefully....

  12. Microtubule dynamics: Caps, catastrophes, and coupled hydrolysis

    DEFF Research Database (Denmark)

    Flyvbjerg, H.; Holy, T.E.; Leibler, S.

    1996-01-01

    individual tubulin dimers, an ignored. In this cap model, GTP hydrolysis is assumed to be stochastic and uncoupled to microtubule growth. Different rates of hydrolysis are assumed for GTP in the cap's interior and for GTP at its boundary with hydrolyzed parts of the microtubule. Expectation values...... and probability distributions relating to available experimental data are derived. Caps are found to be short and the total rate of hydrolysis at a microtubule end is found to be dynamically coupled to growth. The so-called catastrophe rate is a simple function of the microtubule growth rare and fits experimental...... of microtubule growth before dilution. The GTP content of microtubules is found and its rare of hydrolysis is determined under the circumstances created in an experiment designed to measure this GTP content. It is concluded that this experiment's failure to register any GTP content is consistent with the model...

  13. A nanobody targeting the F-actin capping protein CapG restrains breast cancer metastasis.

    Science.gov (United States)

    Van Impe, Katrien; Bethuyne, Jonas; Cool, Steven; Impens, Francis; Ruano-Gallego, David; De Wever, Olivier; Vanloo, Berlinda; Van Troys, Marleen; Lambein, Kathleen; Boucherie, Ciska; Martens, Evelien; Zwaenepoel, Olivier; Hassanzadeh-Ghassabeh, Gholamreza; Vandekerckhove, Joël; Gevaert, Kris; Fernández, Luis Ángel; Sanders, Niek N; Gettemans, Jan

    2013-12-13

    Aberrant turnover of the actin cytoskeleton is intimately associated with cancer cell migration and invasion. Frequently however, evidence is circumstantial, and a reliable assessment of the therapeutic significance of a gene product is offset by lack of inhibitors that target biologic properties of a protein, as most conventional drugs do, instead of the corresponding gene. Proteomic studies have demonstrated overexpression of CapG, a constituent of the actin cytoskeleton, in breast cancer. Indirect evidence suggests that CapG is involved in tumor cell dissemination and metastasis. In this study, we used llama-derived CapG single-domain antibodies or nanobodies in a breast cancer metastasis model to address whether inhibition of CapG activity holds therapeutic merit. We raised single-domain antibodies (nanobodies) against human CapG and used these as intrabodies (immunomodulation) after lentiviral transduction of breast cancer cells. Functional characterization of nanobodies was performed to identify which biochemical properties of CapG are perturbed. Orthotopic and tail vein in vivo models of metastasis in nude mice were used to assess cancer cell spreading. With G-actin and F-actin binding assays, we identified a CapG nanobody that binds with nanomolar affinity to the first CapG domain. Consequently, CapG interaction with actin monomers or actin filaments is blocked. Intracellular delocalization experiments demonstrated that the nanobody interacts with CapG in the cytoplasmic environment. Expression of the nanobody in breast cancer cells restrained cell migration and Matrigel invasion. Notably, the nanobody prevented formation of lung metastatic lesions in orthotopic xenograft and tail-vein models of metastasis in immunodeficient mice. We showed that CapG nanobodies can be delivered into cancer cells by using bacteria harboring a type III protein secretion system (T3SS). CapG inhibition strongly reduces breast cancer metastasis. A nanobody-based approach offers

  14. Testing the "Mudball Earth" Hypothesis: Are Neoproterozoic Glacial Deposits Capped with Supraglacial Dust?

    Science.gov (United States)

    Goodman, J. C.; Alvim Lage, C.

    2014-12-01

    The Snowball Earth hypothesis has inspired several variants which may help to explain some of the great mysteries of the Neoproterozoic glaciations. One of these, the "Mudball Earth", proposes that as the Earth remained completely frozen for millions of years, a layer of dust accumulated on the ice surface. This dust layer would darken the planet, making it easier for the Earth to escape from the highly stable snowball climate state. This hypothesis is testable: after the ice melted at the end of a glacial era, this dust would sink to the bottom of the ocean, possibly forming a distinct clay, mud, or silt layer on the top of the glacial till deposits: this "clay drape" would then be covered by the cap carbonates that mark a return to warm climate. Sublimation and ice flow during the glacial episode should make this layer thicker at the equator and thinner or absent in the poles. Is this clay layer actually present in the rock record? Is it more prevalent at the paleoequator, as predicted? A clay drape has been noticed anecdotally, but no global survey has been done to date. We conducted a thorough literature review of all sites where Neoproterozoic glacial diamictites have been observed, identifying the type of rock that lies between the diamictite and the postglacial cap carbonate, when present, during both Sturtian and Marinoan glacial periods. Only a few publications identify a distinct clay/silt/mud layer that might represent weathered dust. These sites are not grouped by paleolatitude in any obvious way. With access only to published reports, we cannot determine whether such a layer is absent, went unreported, or was misinterpreted by us. With this work we hope to attract the attention of Neoproterozoic field geologists, inviting them to comment on the presence or absence of strata which could confirm or reject the "Mudball" hypothesis.

  15. A hybrid approach to direct pulp capping by using emdogain with a capping material.

    Science.gov (United States)

    Al-Hezaimi, Khalid; Al-Tayar, Badr Abdullah; Bajuaifer, Yaseer Salim; Salameh, Ziad; Al-Fouzan, Khalid; Tay, Franklin R

    2011-05-01

    This study evaluated the formation of reparative hard tissues in baboon pulps after Emdogain (EMD) application in conjunction with 3 pulp-capping materials. Thirty-two premolars in four 3-year-old baboons were randomly assigned to 1 of 3 pulp-capping materials. A split-mouth design and intra-animal side randomization were applied to 3 experimental groups (calcium hydroxide, ProRoot White mineral trioxide aggregate, white Portland cement) and the control group (no pulp-capping material). In the hybrid EMD approach, a small drop of EMD was placed over the exposure site after arrest of hemorrhage. The designated pulp-capping material was placed over the EMD, followed by placement of resin-modified glass ionomer cement over the set/unset pulp-capping material. The animals were killed after 4 months. Histomorphometric analysis and micro-computed tomography were performed on the retrieved specimens. All groups capped with EMD and 1 of the 3 capping materials exhibited similar reparative tissue thickness (P > .05). Dentin tunnel defects were absent in the mineral trioxide aggregate and Portland cement groups after the use of EMD. However, only a tubular was identified from all specimens. Mineral trioxide aggregate produces a better quality reparative hard tissue response with the adjunctive use of Emdogain, when compared with the use of calcium hydroxide. Copyright © 2011 American Association of Endodontists. All rights reserved.

  16. Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment.

    Science.gov (United States)

    Vijayakumar, S P; Menezes, Riya C; Jayarajan, Aditi; Shanker, Kartik

    2016-08-17

    The historical processes underlying high diversity in tropical biodiversity hotspots like the Western Ghats of Peninsular India remain poorly understood. We sampled bush frogs on 13 massifs across the Western Ghats Escarpment and examined the relative influence of Quaternary glaciations, ecological gradients and geological processes on the spatial patterns of lineage and clade diversification. The results reveal a large in situ radiation (more than 60 lineages), exhibiting geographical structure and clade-level endemism, with two deeply divergent sister clades, North and South, highlighting the biogeographic significance of an ancient valley, the Palghat Gap. A majority of the bush frog sister lineages were isolated on adjacent massifs, and signatures of range stasis provide support for the dominance of geological processes in allopatric speciation. In situ diversification events within the montane zones (more than 1800 m) of the two highest massifs suggest a role for climate-mediated forest-grassland persistence. Independent transitions along elevational gradients among sub-clades during the Miocene point to diversification along the elevational gradient. The study highlights the evolutionary significance of massifs in the Western Ghats with the high elevations acting as centres of lineage diversification and the low- and mid-elevations of the southern regions, with deeply divergent lineages, serving as museums. © 2016 The Author(s).

  17. Sea level fall during glaciation stabilized atmospheric CO2by enhanced volcanic degassing.

    Science.gov (United States)

    Hasenclever, Jörg; Knorr, Gregor; Rüpke, Lars H; Köhler, Peter; Morgan, Jason; Garofalo, Kristin; Barker, Stephen; Lohmann, Gerrit; Hall, Ian R

    2017-07-06

    Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO 2 , which may have modulated the climate system's descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO 2 , instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO 2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO 2 predominantly controlled by marine volcanism on multi-millennial timescales of ∼5,000-15,000 years.

  18. Formation of most of our coal brought Earth close to global glaciation

    Science.gov (United States)

    Feulner, Georg

    2017-10-01

    The bulk of Earth's coal deposits used as fossil fuel today was formed from plant debris during the late Carboniferous and early Permian periods. The high burial rate of organic carbon correlates with a significant drawdown of atmospheric carbon dioxide (CO2) at that time. A recent analysis of a high-resolution record reveals large orbitally driven variations in atmospheric CO2 concentration between ˜150 and 700 ppm for the latest Carboniferous and very low values of 100 ± 80 ppm for the earliest Permian. Here, I explore the sensitivity of the climate around the Carboniferous/Permian boundary to changes in Earth's orbital parameters and in atmospheric CO2 using a coupled climate model. The coldest orbital configurations are characterized by large axial tilt and small eccentricities of Earth's elliptical orbit, whereas the warmest configuration occurs at minimum tilt, maximum eccentricity, and a perihelion passage during Northern hemisphere spring. Global glaciation occurs at CO2 concentrations fossil carbon stored in Earth's coal deposits.

  19. A process-based hierarchical framework for monitoring glaciated alpine headwaters

    Science.gov (United States)

    Weekes, Anne A.; Torgersen, Christian E.; Montgomery, David R.; Woodward, Andrea; Bolton, Susan M.

    2012-01-01

    Recent studies have demonstrated the geomorphic complexity and wide range of hydrologic regimes found in alpine headwater channels that provide complex habitats for aquatic taxa. These geohydrologic elements are fundamental to better understand patterns in species assemblages and indicator taxa and are necessary to aquatic monitoring protocols that aim to track changes in physical conditions. Complex physical variables shape many biological and ecological traits, including life history strategies, but these mechanisms can only be understood if critical physical variables are adequately represented within the sampling framework. To better align sampling design protocols with current geohydrologic knowledge, we present a conceptual framework that incorporates regional-scale conditions, basin-scale longitudinal profiles, valley-scale glacial macroform structure, valley segment-scale (i.e., colluvial, alluvial, and bedrock), and reach-scale channel types. At the valley segment- and reach-scales, these hierarchical levels are associated with differences in streamflow and sediment regime, water source contribution and water temperature. Examples of linked physical-ecological hypotheses placed in a landscape context and a case study using the proposed framework are presented to demonstrate the usefulness of this approach for monitoring complex temporal and spatial patterns and processes in glaciated basins. This approach is meant to aid in comparisons between mountain regions on a global scale and to improve management of potentially endangered alpine species affected by climate change and other stressors.

  20. Presumable incipient hybrid speciation of door snails in previously glaciated areas in the Caucasus.

    Science.gov (United States)

    Koch, Eva L; Neiber, Marco T; Walther, Frank; Hausdorf, Bernhard

    2016-04-01

    Homoploid hybrid speciation, speciation by hybridization without a change in chromosome number, may be the result of an encounter of closely related species in a habitat that is different from that usually occupied by these species. In the northwestern Caucasus the land snail species Micropontica caucasica and M. circassica form two distinct entities with little admixture at low and intermediate altitudes. However, at higher altitudes in the Lagonaki plateau, which were repeatedly glaciated, Micropontica populations with intermediate characters occur. Admixture analyses based on AFLP data demonstrated that the populations from the Lagonaki plateau are homoploid hybrids that now form a cluster separate from the parental species. The Lagonaki populations are characterized by a mtDNA haplotype clade that has been found in the parental species only once. The fixation of this haplotype clade in most hybrid populations suggests that these haplotypes are better adapted to the cooler conditions in high altitude habitats and have replaced the haplotypes of the parental species in a selective sweep. The fixation of a presumably adaptive mitochondrial haplotype clade in the Lagonaki populations is an important step towards speciation under the differential fitness species concept. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation

    Science.gov (United States)

    Coxall, Helen K.; Huck, Claire E.; Huber, Matthew; Lear, Caroline H.; Legarda-Lisarri, Alba; O'Regan, Matt; Sliwinska, Kasia K.; van de Flierdt, Tina; de Boer, Agatha M.; Zachos, James C.; Backman, Jan

    2018-03-01

    The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep North Atlantic. Here we present detailed geochemical records from North Atlantic sediment cores located close to sites of deep-water formation. We find that prior to 36 Ma, the northwestern Atlantic was stratified, with nutrient-rich, low-salinity bottom waters. This restricted basin transitioned into a conduit for NCW that began flowing southwards approximately one million years before the initial Antarctic glaciation. The probable trigger was tectonic adjustments in subarctic seas that enabled an increased exchange across the Greenland-Scotland Ridge. The increasing surface salinity and density strengthened the production of NCW. The late Eocene deep-water mass differed in its carbon isotopic signature from modern values as a result of the leakage of fossil carbon from the Arctic Ocean. Export of this nutrient-laden water provided a transient pulse of CO2 to the Earth system, which perhaps caused short-term warming, whereas the long-term effect of enhanced NCW formation was a greater northward heat transport that cooled Antarctica.

  2. Large-scale evolution of the central-east Greenland margin: New insights to the North Atlantic glaciation history

    Science.gov (United States)

    Pérez, Lara F.; Nielsen, Tove; Knutz, Paul C.; Kuijpers, Antoon; Damm, Volkmar

    2018-04-01

    The continental shelf of central-east Greenland is shaped by several glacially carved transverse troughs that form the oceanward extension of the major fjord systems. The evolution of these troughs through time, and their relation with the large-scale glaciation of the Northern Hemisphere, is poorly understood. In this study seismostratigraphic analyses have been carried out to determine the morphological and structural development of this important sector of the East Greenland glaciated margin. The age of major stratigraphic discontinuities has been constrained by a direct tie to ODP site 987 drilled in the Greenland Sea basin plain off Scoresby Sund fan system. The areal distribution and internal facies of the identified seismic units reveal the large-scale depositional pattern formed by ice-streams draining a major part of the central-east Greenland ice sheet. Initial sedimentation along the margin was, however, mainly controlled by tectonic processes related to the margin construction, continental uplift, and fluvial processes. From late Miocene to present, progradational and erosional patterns point to repeated glacial advances across the shelf. The evolution of depo-centres suggests that ice sheet advances over the continental shelf have occurred since late Miocene, about 2 Myr earlier than previously assumed. This cross-shelf glaciation is more pronounced during late Miocene and early Pliocene along Blosseville Kyst and around the Pliocene/Pleistocene boundary off Scoresby Sund; indicating a northward migration of the glacial advance. The two main periods of glaciation were separated by a major retreat of the ice sheet to an inland position during middle Pliocene. Mounded-wavy deposits interpreted as current-related deposits suggest the presence of changing along-slope current dynamics in concert with the development of the modern North Atlantic oceanographic pattern.

  3. Chronostratigraphy of the Vistulian Glaciation (Weichselian) on the Kujawy Moraine Plateau (Central Poland) Based on Lithostratigraphic Research and OSL Dating

    OpenAIRE

    Przegiętka, Krzysztof; Chruścińska, Alicja; Oczkowski, Hubert Lucjan; Molewski, Paweł

    2008-01-01

    The subject of the investigations presented here is fixing dilemmatic character (transgressive or recessive) of the Poznań phase of the Vistulian (Weichselian) Glaciation and answering the question about the possibility of lithostratigraphic separation of this phase from the Leszno phase in the region of so called Vistula lob. Here we present the outcomes of the research project carried out on a few tills exposures, which constitute the sedimentological record of the last ice sheet advance on...

  4. The Effectiveness of Caps on Political Lobbying

    NARCIS (Netherlands)

    Matejka, M.; Onderstal, A.M.; De Waegenaere, A.M.B.

    2002-01-01

    In this paper, we analyze a lobby game, modelled as an all-pay auction in which interest groups submit bids in order to obtain a political prize.The bids are restricted to be below a cap imposed by the government.For both an incomplete and a complete information setting we show the following

  5. Added Mass of a Spherical Cap Body

    Czech Academy of Sciences Publication Activity Database

    Šimčík, Miroslav; Punčochář, Miroslav; Růžička, Marek

    2014-01-01

    Roč. 118, OCT 18 (2014), s. 1-8 ISSN 0009-2509 R&D Projects: GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : spherical cap * added mass * single particle Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.337, year: 2014

  6. Preliminary Test for Constitutive Models of CAP

    International Nuclear Information System (INIS)

    Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon

    2010-01-01

    The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper

  7. Preliminary Test for Constitutive Models of CAP

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Ha, Sang Jun; Choi, Hoon [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper

  8. Facially amphiphilic thiol capped gold and silver nanoparticles

    Indian Academy of Sciences (India)

    Abstract. A series of bile acid-derived facially amphiphilic thiols have been used to cap sliver and gold nanoparticles. The self-assembling properties of these steroid-capped nanoparticles have been investigated and reported in this article.

  9. NAMMA CLOUD MICROPHYSICS (CAPS-PIP) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Cloud Microphysics (CAPS-PIP) dataset consists of particle size distributions from the Clouds, Aerosol and Preciptaition Spectrometer (CAPS) and the...

  10. An integrative water balance model framework for a changing glaciated catchment in the Andes of Peru

    Science.gov (United States)

    Drenkhan, Fabian; Huggel, Christian; García Hernández, Javier; Fluixá-Sanmartín, Javier; Seidel, Jochen; Muñoz Asmat, Randy

    2017-04-01

    In the Santa River catchment [SRC] (Cordillera Blanca, Andes of Peru), human livelihoods strongly depend on year-round streamflow from glaciers and reservoirs, particularly in the dry season and in adjacent arid lowlands. Perennial glacial streamflow represents a buffer to water shortages, annual discharge variability and river contamination levels. However, climate change impacts, consecutive glacier shrinkage as well as new irrigated agriculture and hydropower schemes, population growth and thus water allocation might increase water scarcity in several areas of the SRC. This situation exerts further pressure and conflict potential over water resources and stresses the need to analyze both water supply and demand trends in a multidisciplinary and interlinked manner. In this context, an integrative glacio-hydrological framework was developed based on the Glacier and Snow Melt (GSM) and SOil CONTribution (SOCONT) models using the semi-distributed free software RS MINERVE. This water balance model incorporates hydroclimatic, socioeconomic and hydraulic objects and data at daily scale (with several gaps) for the last 50 years (1965-2015). A particular challenge in this context represents the poor data availability both in quantity and quality. Therefore, the hydroclimatic dataset to be used had to be carefully selected and data gaps were filled applying a statistical copula-based approach. The socioeconomic dataset of water demand was elaborated using several assumptions based on further census information and experiences from other projects in the region. Reservoirs and hydropower models were linked with additional hydraulic data. In order to increase model performance within a complex topography of the 11660 km2 SRC, the area was divided into 22 glaciated (GSM) and 42 non-glaciated (SOCONT) subcatchment models. Additionally, 382 elevation bands at 300 m interval were created and grouped into 22 different calibration zones for the whole SRC. The model was calibrated

  11. District element modelling of the rock mass response to glaciation at Finnsjoen, central Sweden

    International Nuclear Information System (INIS)

    Rosengren, L.; Stephansson, O.

    1990-12-01

    Six rock mechanics models of a cross section of the Finnsjoen test site have been simulated by means of distinct element analysis and the computer code UDEC. The rock mass response to glaciation, deglaciation, isostatic movements and water pressure from an ice lake have been simulated. Four of the models use a boundary condition with boundary elements at the bottom and sides of the model. This gives a state of stress inside the model which agrees well with the analytical solution where the horizontal and vertical stresses are almost similar. Roller boundaries were applied to two models. This boundary condition cause zero lateral displacement at the model boundaries and the horizontal stress are always less than the vertical stress. Isostatic movements were simulated in one model. Two different geometries of fracture Zone 2 were simulated. Results from modelling the two different geometries show minor changes in stresses, displacements and failure of fracture zones. Under normal pore pressure conditions in the rock mass the weight of the ice load increases the vertical stresses in the models differ depending on the boundary condition. An ice thickness of 3 km and 1 km and an ice wedge of 1 km thickness covering half the top surface of the model have been simulated. For each loading sequence of the six models a complete set of data about normal stress, stress profiles along selected sections, displacements and failure of fracture zones are presented. Based on the results of this study a protection zone of about 100 m width from the outer boundary of stress discontinuity to the repository location is suggested. This value is based on the result that the stress disturbance diminishes at this distance from the outer boundary of the discontinuity. (25 refs.) (authors)

  12. Sensor Webs and Virtual Globes: Enabling Understanding of Changes in a partially Glaciated Watershed

    Science.gov (United States)

    Heavner, M.; Fatland, D. R.; Habermann, M.; Berner, L.; Hood, E.; Connor, C.; Galbraith, J.; Knuth, E.; O'Brien, W.

    2008-12-01

    The University of Alaska Southeast is currently implementing a sensor web identified as the SouthEast Alaska MOnitoring Network for Science, Telecommunications, Education, and Research (SEAMONSTER). SEAMONSTER is operating in the partially glaciated Mendenhall and Lemon Creek Watersheds, in the Juneau area, on the margins of the Juneau Icefield. These watersheds are studied for both 1. long term monitoring of changes, and 2. detection and analysis of transient events (such as glacier lake outburst floods). The heterogeneous sensors (meteorologic, dual frequency GPS, water quality, lake level, etc), power and bandwidth constraints, and competing time scales of interest require autonomous reactivity of the sensor web. They also present challenges for operational management of the sensor web. The harsh conditions on the glaciers provide additional operating constraints. The tight integration of the sensor web and virtual global enabling technology enhance the project in multiple ways. We are utilizing virtual globe infrastructures to enhance both sensor web management and data access. SEAMONSTER utilizes virtual globes for education and public outreach, sensor web management, data dissemination, and enabling collaboration. Using a PosgreSQL with GIS extensions database coupled to the Open Geospatial Consortium (OGC) Geoserver, we generate near-real-time auto-updating geobrowser files of the data in multiple OGC standard formats (e.g KML, WCS). Additionally, embedding wiki pages in this database allows the development of a geospatially aware wiki describing the projects for better public outreach and education. In this presentation we will describe how we have implemented these technologies to date, the lessons learned, and our efforts towards greater OGC standard implementation. A major focus will be on demonstrating how geobrowsers and virtual globes have made this project possible.

  13. Population genetics of the westernmost distribution of the glaciations-surviving black truffle Tuber melanosporum.

    Science.gov (United States)

    García-Cunchillos, Iván; Sánchez, Sergio; Barriuso, Juan José; Pérez-Collazos, Ernesto

    2014-04-01

    The black truffle (Tuber melanosporum Vittad.) is an important natural resource due to its relevance as a delicacy in gastronomy. Different aspects of this hypogeous fungus species have been studied, including population genetics of French and Italian distribution ranges. Although those studies include some Spanish populations, this is the first time that the genetic diversity and genetic structure of the wide geographical range of the natural Spanish populations have been analysed. To achieve this goal, 23 natural populations were sampled across the Spanish geographical distribution. ISSR technique demonstrated its reliability and capability to detect high levels of polymorphism in the species. Studied populations showed high levels of genetic diversity (h N  = 0.393, h S  = 0.678, Hs = 0.418), indicating a non threatened genetic conservation status. These high levels may be a consequence of the wide distribution range of the species, of its spore dispersion by animals, and by its evolutionary history. AMOVA analysis showed a high degree of genetic structure among populations (47.89%) and other partitions as geographical ranges. Bayesian genetic structure analyses differentiated two main Spanish groups separated by the Iberian Mountain System, and showed the genetic uniqueness of some populations. Our results suggest the survival of some of these populations during the last glaciation, the Spanish southern distribution range perhaps surviving as had occurred in France and Italy, but it is also likely that specific northern areas may have acted as a refugia for the later dispersion to other calcareous areas in the Iberian Peninsula and probably France.

  14. Diamictite From the Chukchi Sea: Evidence of Northern Glaciation During the Late Miocene and Early Pliocene

    Science.gov (United States)

    Phillips, R. L.; Ager, T. A.; Barron, J. A.; Starratt, S.

    2001-12-01

    Ten vibracores obtained across the Chukchi Sea from the southeast to the northwest over a distance of 200 km contain a thin diamictite up to 310 cm thick. The diamictite represents a late Miocene and early Pliocene glacial marine matrix-supported deposit overlain by thin nonmarine Pleistocene and marine Holocene strata. Seven cores end in the diamictite, whereas, three cores also sampled underlying Cretaceous tephra. Horizontal parallel laminations, thin black organic-rich beds, bioturbated strata, and structureless mud characterize this ice-rafted deposit. The texture of the diamictite is heterogeneous with gravel-size clasts, to 6 cm diameter, floating in a sandy mud matrix comprising up to 40 percent of the sediment. Quartz and chert comprise up to 68 percent of the gravel-size dropstone clasts with siltstone and sandstone forming the next most abundant clast type, to 32 percent. The presence of a varied marine fauna consisting of benthic foraminifers, diatoms, sponge spicules, ostracodes, and pelecypods shows that the Chukchi Sea was covered with marine waters with the clastic sediment deposited from floating glacial icebergs. Marine diatoms indicate that the diamictite as latest Miocene or earliest Pliocene (5.5 to 5.0 Ma) based on the overlapping ranges of Thalassiosira oestrupii and Cosmiodiscus insignis. This is the same age (Subzone b of the Neodenticula Kamtschatica Zone of the North Pacific diatom biochronology) as the opening of the Bering Strait. The widespread occurrence of ice-rafted detritus both in North Atlantic and North Pacific sediments in the latest Miocene indicates a cooling trend with the initiation of continental glaciation in the Northern Hemisphere. The highstand glacial-derived diamictite in the Chukchi Sea is a result of this cooling trend and documents the formation of continental glaciers in northern Alaska and with tidewater glaciers reaching the Chukchi Sea between 5.5 and 5 Ma.

  15. A study of the Würm glaciation focused on the Valais region (Alps

    Directory of Open Access Journals (Sweden)

    P. Becker

    2017-12-01

    Full Text Available During the Last Glacial Maximum (LGM, the glaciation in the European Alps reached maximum ice extent. We already simulated the steady states of the Alpine ice coverage for several climate drivers in Becker et al. (2016 and heighten in this article such studies for the Swiss Valais region. To this end, we employ the Parallel Ice Sheet Model (PISM, which combines the shallow ice approximation (SIA with basal sliding elements of the shallow shelf approximation (SSA, and subject this model to various external driving mechanisms. We further test the sensitivity of this kind of the ice coverage in the Valais region to a temporally constant climate and to monotonic ice sheet build-up from inception to steady state as well as to the Dye 3 temperature driving during the past 120 000 years. We also test differences in the precipitation patterns exerted to the northern and southern catchment areas of the Rhone and Toce rivers to possible transfluence changes in ice from the northern to the southern catchment areas and vice versa. Moreover, we study the effect of the ice deformability and estimate the removal up to 1000 m of sediment in the Rhone Valley and study the removal of rock hindering the flow through the valley cross section at the knee of Martigny. All these studies took place because of a discrepancy in the ice height prediction of the modelled ice sheet with its geomorphologically reconstructed counterpart with proxy data obtained by Bini et al. (2009 as well as a difference in ice height between the two of up to 800 m. Unfortunately, all the scenarios in the model do not sufficiently reduce this discrepancy in the height prediction and the geomorphological reconstruction. The model results have discovered an ice dynamical discrepancy with the land map in Bini et al. (2009.

  16. Sulfate exports from multiple catchments in a glaciated forested watershed in western New York, USA.

    Science.gov (United States)

    Inamdar, Shreeram P; Mitchell, Myron J

    2008-04-01

    Sulfate (SO4(2-)) concentrations and fluxes were studied for multiple storm events in the Point Peter Brook watershed, a glaciated, forested watershed located in Western New York, USA. Investigations were performed across one large (696 ha) and three small (1.6-3.4 ha) catchments with varying extent of riparian and wetland areas. Concentrations of SO4(2-) in groundwater sources (mean values: 238-910 micromol(c) L(-1)) were considerably greater than concentrations recorded for rainfall (60 micromol(c) L(-1)) and throughfall (72-129 micromol(c) L(-1)). Seasonality in SO4(2-) concentrations was most pronounced for valley-bottom riparian waters with maximum concentrations in late winter-spring (February-March) and a minimum in late summer (August). Concentrations of SO4(2-) in wetland water were considerably less than riparian water indicating the likelihood of SO4(2-) reduction in anoxic wetland conditions. Storm events displayed a dilution pattern in SO4(2-) concentrations with a minimum coinciding with the maximum in throughfall contributions. End member mixing analysis (EMMA) was able to predict the storm event concentrations of SO4(2-) for four of the six comparisons. Concentrations of SO4(2-) at the outlet of the large (696 ha) catchment were much greater than values recorded for the smaller catchments. Exports of SO4(2-) in streamflow exceeded the inputs from atmospheric deposition suggesting that watersheds like Point Peter Brook may not show any immediate response to decreases in atmospheric SO4(2-) deposition.

  17. Biogeochemical cycling in the Bering Sea over the onset of major Northern Hemisphere Glaciation

    Science.gov (United States)

    Swann, George E. A.; Snelling, Andrea M.; Pike, Jennifer

    2016-09-01

    The Bering Sea is one of the most biologically productive regions in the marine system and plays a key role in regulating the flow of waters to the Arctic Ocean and into the subarctic North Pacific Ocean. Cores from Integrated Ocean Drilling Program (IODP) Expedition 323 to the Bering Sea provide the first opportunity to obtain reconstructions from the region that extend back to the Pliocene. Previous research at Bowers Ridge, south Bering Sea, has revealed stable levels of siliceous productivity over the onset of major Northern Hemisphere Glaciation (NHG) (circa 2.85-2.73 Ma). However, diatom silica isotope records of oxygen (δ18Odiatom) and silicon (δ30Sidiatom) presented here demonstrate that this interval was associated with a progressive increase in the supply of silicic acid to the region, superimposed on shift to a more dynamic environment characterized by colder temperatures and increased sea ice. This concluded at 2.58 Ma with a sharp increase in diatom productivity, further increases in photic zone nutrient availability and a permanent shift to colder sea surface conditions. These transitions are suggested to reflect a gradually more intense nutrient leakage from the subarctic northwest Pacific Ocean, with increases in productivity further aided by increased sea ice- and wind-driven mixing in the Bering Sea. In suggesting a linkage in biogeochemical cycling between the south Bering Sea and subarctic Northwest Pacific Ocean, mainly via the Kamchatka Strait, this work highlights the need to consider the interconnectivity of these two systems when future reconstructions are carried out in the region.

  18. Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic

    Science.gov (United States)

    Segal, Rebecca A.; Lantz, Trevor C.; Kokelj, Steven V.

    2016-03-01

    Climate change is increasing the frequency and intensity of thermokarst, but the influences of regional climate and physiography remain poorly understood. Retrogressive thaw slumping is one of the most dynamic forms of thermokarst and affects many areas of glaciated terrain across northwestern Canada. In this study, we used airphotos and satellite imagery to investigate the influence of climate and landscape factors on thaw slump dynamics. We assessed slump size, density, and growth rates in four regions of ice-rich terrain with contrasting climate and physiographic conditions: the Jesse Moraine, the Tuktoyaktuk Coastlands, the Bluenose Moraine, and the Peel Plateau. Observed increases in: (1) the area impacted by slumps (+2 to +407%), (2) average slump sizes (+0.31 to +1.82 ha), and (3) slump growth rates (+169 to +465 m2 yr-1) showed that thermokarst activity is rapidly accelerating in ice-rich morainal landscapes in the western Canadian Arctic, where slumping has become a dominant driver of geomorphic change. Differences in slump characteristics among regions indicate that slump development is strongly influenced by topography, ground ice conditions, and Quaternary history. Observed increases in slump activity occurred in conjunction with increases in air temperature and precipitation, but variation in slump activity among the four regions suggests that increased precipitation has been an important driver of change. Our observation that the most rapid intensification of slump activity occurred in the coldest environment (the Jesse Moraine on Banks Island) indicates that ice-cored landscapes in cold permafrost environments are highly vulnerable to climate change.

  19. CMS end-cap yoke at the detector's assembly site.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The magnetic flux generated by the superconducting coil in the CMS detector is returned via an iron yoke comprising three end-cap discs at each end (end-cap yoke) and five concentric cylinders (barrel yoke). This picture shows the first of three end-cap discs (red) seen through the outer cylinder of the vacuum tank which will house the superconducting coil.

  20. 42 CFR 418.309 - Hospice cap amount.

    Science.gov (United States)

    2010-10-01

    ...) MEDICARE PROGRAM HOSPICE CARE Payment for Hospice Care § 418.309 Hospice cap amount. The hospice cap amount... Medicare beneficiaries who elected to receive hospice care from that hospice during the cap period. For... election to receive hospice care, in accordance with § 418.24, from the hospice during the period beginning...

  1. 47 CFR 61.41 - Price cap requirements generally.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Price cap requirements generally. 61.41 Section... (CONTINUED) TARIFFS General Rules for Dominant Carriers § 61.41 Price cap requirements generally. (a... companies shall not bar a carrier from electing price cap regulation provided the carrier is otherwise...

  2. Greening CAP payments: a missed opportunity?

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Alan

    2013-01-15

    At an important point in the current reform of the Common Agricultural Policy (CAP), a new IIEA policy brief by Professor Alan Matthews, one of the EU’s foremost experts on the topic, considers proposals to green direct farm payments. Professor Matthews argues that proposed greening of direct payments – the key innovation in the current round of CAP Reform – look likely to fail. While greening may survive as a concept, the likely outcome of the negotiations between Agriculture Ministers and the European Parliament will deliver little practical environmental benefit. The paper examines the rationale underpinning greening, arguing that it exists to justify the continuation of a large agricultural budget, explores reasons for the apparent failure of the proposals, and reflects on the implications for future efforts to better integrate environmental objectives into EU agriculture policy. This is the first in a series of Environment Nexus policy briefs by leading experts in the fields of agriculture, energy, climate change and water.

  3. ATLAS End-cap Part II

    CERN Multimedia

    2007-01-01

    The epic journey of the ATLAS magnets is drawing to an end. On Thursday 12 July, the second end-cap of the ATLAS toroid magnet was lowered into the cavern of the experiment with the same degree of precision as the first (see Bulletin No. 26/2007). This spectacular descent of the 240-tonne component, is one of the last transport to be completed for ATLAS.

  4. Cytocompatibility and Antibacterial Properties of Capping Materials

    OpenAIRE

    Poggio, Claudio; Arciola, Carla Renata; Beltrami, Riccardo; Monaco, Annachiara; Dagna, Alberto; Lombardini, Marco; Visai, Livia

    2014-01-01

    The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towa...

  5. MycoCAP - Mycobacterium Comparative Analysis Platform.

    Science.gov (United States)

    Choo, Siew Woh; Ang, Mia Yang; Dutta, Avirup; Tan, Shi Yang; Siow, Cheuk Chuen; Heydari, Hamed; Mutha, Naresh V R; Wee, Wei Yee; Wong, Guat Jah

    2015-12-15

    Mycobacterium spp. are renowned for being the causative agent of diseases like leprosy, Buruli ulcer and tuberculosis in human beings. With more and more mycobacterial genomes being sequenced, any knowledge generated from comparative genomic analysis would provide better insights into the biology, evolution, phylogeny and pathogenicity of this genus, thus helping in better management of diseases caused by Mycobacterium spp.With this motivation, we constructed MycoCAP, a new comparative analysis platform dedicated to the important genus Mycobacterium. This platform currently provides information of 2108 genome sequences of at least 55 Mycobacterium spp. A number of intuitive web-based tools have been integrated in MycoCAP particularly for comparative analysis including the PGC tool for comparison between two genomes, PathoProT for comparing the virulence genes among the Mycobacterium strains and the SuperClassification tool for the phylogenic classification of the Mycobacterium strains and a specialized classification system for strains of Mycobacterium abscessus. We hope the broad range of functions and easy-to-use tools provided in MycoCAP makes it an invaluable analysis platform to speed up the research discovery on mycobacteria for researchers. Database URL: http://mycobacterium.um.edu.my.

  6. Pulp-Capping with Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Peycheva Kalina

    2015-11-01

    Full Text Available There are two considerations for direct pulp capping - accidental mechanical pulp exposure and exposure caused by caries. Mineral trioxide aggregate (MTA was used as pulp-capping material to preserve the vitality of the pulpal tissues. Follow-up examinations revealed that treatment was successful in preserving pulpal vitality and continued development of the tooth. On the basis of available information, it appears that MTA is the material of choice for some clinical applications. Material and methods: Cases 18 - 8 teeth with grey MTA, 10 teeth with white MTA; diagnose: Pulpitis chronica ulcerosa, Electro pulpal test (EOD - 30-35 μA, pre-clinical X-ray - without changes in the structures, follow ups for 4 years. Successful treatments: without clinical symptoms and changes in the X-rays: 5 teeth with grey MTA, 8 teeth with white MTA for period of 4 years. Unsuccessful treatments: Clinical symptoms and sometimes changes in the X-ray: 3 with grey MTA, 2 with white MTA. MTA is an appropriate material for pulp-capping and follow-up examinations revealed that the treatment was successful in preserving pulpal vitality.

  7. CAP protein superfamily members in Toxocara canis.

    Science.gov (United States)

    Stroehlein, Andreas J; Young, Neil D; Hall, Ross S; Korhonen, Pasi K; Hofmann, Andreas; Sternberg, Paul W; Jabbar, Abdul; Gasser, Robin B

    2016-06-24

    Proteins of the cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 (CAP) superfamily are recognized or proposed to play roles in parasite development and reproduction, and in modulating host immune attack and infection processes. However, little is known about these proteins for most parasites. In the present study, we explored CAP proteins of Toxocara canis, a socioeconomically important zoonotic roundworm. To do this, we mined and curated transcriptomic and genomic data, predicted and curated full-length protein sequences (n = 28), conducted analyses of these data and studied the transcription of respective genes in different developmental stages of T. canis. In addition, based on information available for Caenorhabditis elegans, we inferred that selected genes (including lon-1, vap-1, vap-2, scl-1, scl-8 and scl-11 orthologs) of T. canis and their interaction partners likely play central roles in this parasite's development and/or reproduction via TGF-beta and/or insulin-like signaling pathways, or via host interactions. In conclusion, this study could provide a foundation to guide future studies of CAP proteins of T. canis and related parasites, and might assist in finding new interventions against diseases caused by these parasites.

  8. Continental glaciation and its potential impact on a used-fuel disposal vault in the Canadian Shield

    International Nuclear Information System (INIS)

    Ates, Y.; Bruneau, D.; Ridgway, W.R.

    1997-09-01

    AECL has been assessing the concept of nuclear fuel waste disposal in a vault excavated at a depth ranging between 500 m and 1000 m in a plutonic rock mass of the Canadian Shield. Glaciation is a natural process that has occurred in the past, and is likely to occur in the future, thus causing changes in the loading conditions on the rock mass hosting the disposal vault. Because the rock mass is a natural barrier to the migration of radionuclides, it is important to evaluate its integrity under load changes caused by the glaciation process. Assuming that the magnitude and extent of the future glaciation will be similar to those of the past, we have reviewed published data pertaining to the last continental ice sheet that covered a large area of North America. Estimates have been made for the magnitude of stresses due to ice sheet loading for a vault located at depths of 500 to 1000 m. These analyses have shown that the uniform loading of a continental ice sheet would reduce the deviatoric stresses in the Canadian Shield, creating more favourable conditions than those existing at the present time, namely, high horizontal stresses. The effects of surface erosion and increase in the in-situ shear stresses have also been examined. Based on the existing data and structural modelling studies, there would be no significant structural effect on a disposal vault located at 1000-m depth in a plutonic rock. At its maximum size, an ice sheet comparable to the Laurentide ice sheet could reactivate the faults and fracture zones along the perimeter areas. Our analyses have been based on fully drained conditions only. At a potential disposal site, it would be important also to consider the potential for excess pore pressure in the analyses. (author)

  9. Continental glaciation and its potential impact on a used-fuel disposal vault in the Canadian Shield

    Energy Technology Data Exchange (ETDEWEB)

    Ates, Y.; Bruneau, D.; Ridgway, W.R

    1997-09-01

    AECL has been assessing the concept of nuclear fuel waste disposal in a vault excavated at a depth ranging between 500 m and 1000 m in a plutonic rock mass of the Canadian Shield. Glaciation is a natural process that has occurred in the past, and is likely to occur in the future, thus causing changes in the loading conditions on the rock mass hosting the disposal vault. Because the rock mass is a natural barrier to the migration of radionuclides, it is important to evaluate its integrity under load changes caused by the glaciation process. Assuming that the magnitude and extent of the future glaciation will be similar to those of the past, we have reviewed published data pertaining to the last continental ice sheet that covered a large area of North America. Estimates have been madefor the magnitude of stresses due to ice sheet loading for a vault located at depths of 500 to 1000 m. These analyses have shown that the uniform loading of a continental ice sheet would reduce the deviatoric stresses in the Canadian Shield, creating more favourable conditions than those existing at the present time, namely, high horizontal stresses. The effects of surface erosion and increase in the in-situ shear stresses have also been examined. Based on the existing data and structural modelling studies, there would be no significant structural effect on a disposal vault located at 1000-m depth in a plutonic rock. At its maximum size, an ice sheet comparable to the Laurentide ice sheet could reactivate the faults and fracture zones along the perimeter areas. Our analyses have been based on fully drained conditions only. At a potential disposal site, it would be important also to consider the potential for excess pore pressure in the analyses. (author)

  10. Is diatom richness responding to catchment glaciation? A case study from Cana+9dian headwater streams

    Directory of Open Access Journals (Sweden)

    Eugen Rott

    2012-01-01

    Full Text Available Due to global change affecting glaciers worldwide, glacial streams are seen as threatened environments deserving specific scientific interest. Glacial streams from the Coast Range and Rocky Mountains in British Columbia and at the border to Alberta were investigated. In particular glacial streams and downstream sites in the Joffré Lakes Provincial Park, a near by mountain river and two large glacial streams in the Rocky Mountains (Kootenay Range, Jasper National Park were studied. Regardless of a high variability of catchment glaciation (1 to 99% thin organic biofilms with firmly attached diatom frustules of the genera Achnanthidium, Psammothidium, Encyonema, Gomphonema and fragilaroid taxa were found in all cases. In spite of fundamentally different geological conditions between the Coast Range sites and the Rocky Mountain sites, the pioneer taxon Achnanthidium minutissimum (with a slimy long ecomorph was dominating quantitatively in most of the glacier stream samples together with the rheobiontic Hannaea arcus. Individual glacier stream samples were characterized by the dominance of Achnanthidium petersenii and Gomphonema calcifugum/Encyonema latens. The diatom community analysis (cluster analysis revealed the expected separation of glacier stream sites and sites of the lower segments of the river continuum (e.g., dominance of Diatoma ehrenbergii in the mountain river. In the Joffré area, the total species richness of turbid glacial streams close to the glacier mouth was significantly lower than in the more distant sites. The two largest glacial streams in the Rocky Mountains showed divergent results with a remarkable high species richness (43 taxa at the Athabasca River origin (Columbia Icefield and low diversity in Illecillewaet river (9 km downstream the glacier mouth. From the biogeographical point of view the dominant taxa comprised mainly widespread pioneer species coping best with the unstable conditions, while the subdominant taxa

  11. The relation between gravity rate of change and vertical displacement in previously glaciated areas

    Science.gov (United States)

    Olsson, Per-Anders; Milne, Glenn; Scherneck, Hans-Georg; Ågren, Jonas

    2015-01-01

    The rate of change of surface gravity, g˙, and vertical deformation rate of the solid surface, u˙, are two observables of glacial isostatic adjustment (GIA). They contribute with different information on the same phenomenon. Their relation contains information of the underlying physics and a trustworthy relation allows to combine these observations to strengthen the overall observational accuracy of the phenomenon. In this paper we investigate the predicted relation between g˙ and u˙ in previously glaciated areas. We use the normal mode approach for one dimensional earth models and solutions of the sea level equation with time-dependent coastline geometry. Numerical predictions of g˙ and u˙ are computed for Laurentia, Fennoscandia and the British Isles respectively, using six different earth models. Within each region a linear trend is then fitted using the relation g˙ = Cu˙ +g˙0. The estimated C and g˙0 differ more between the regions than between different earth models within each region. For Fennoscandia C ≈ -0.163 μGal/mm and for Laurentia C ≈ -0.152 μGal/mm. Maximum residuals between the linear trend and spatially varying model predictions of g˙ are 0.04 μGal/yr in Fennoscandia and 0.17 μGal/yr in Laurentia. For the British Isles the results are harder to interpret, mainly since this region is located on the zero uplift isoline of Fennoscandia. In addition, we show temporal variation of the relation since the last glacial maximum till present-day. The temporal and spatial variation of the relation between g˙ and u˙ can be explained by (i) the elastic respectively viscous proportion of the total signal and (ii) the spectral composition of the regional signal. Additional local effects, such as the Newtonian attraction and elastic deformation from local sea level changes, are examined in a case study for six stations in the Nordic absolute gravity network. The influence of these local effects on the relation between g˙ and u˙ is negligible

  12. Groundwater-supported evapotranspiration within glaciated watersheds under conditions of climate change

    Science.gov (United States)

    Cohen, D.; Person, M.; Daannen, R.; Locke, S.; Dahlstrom, D.; Zabielski, V.; Winter, T.C.; Rosenberry, D.O.; Wright, H.; Ito, E.; Nieber, J.L.; Gutowski, W.J.

    2006-01-01

    This paper analyzes the effects of geology and geomorphology on surface-water/-groundwater interactions, evapotranspiration, and recharge under conditions of long-term climatic change. Our analysis uses hydrologic data from the glaciated Crow Wing watershed in central Minnesota, USA, combined with a hydrologic model of transient coupled unsaturated/saturated flow (HYDRAT2D). Analysis of historical water-table (1970-1993) and lake-level (1924-2002) records indicates that larger amplitude and longer period fluctuations occur within the upland portions of watersheds due to the response of the aquifer system to relatively short-term climatic fluctuations. Under drought conditions, lake and water-table levels fell by as much as 2-4 m in the uplands but by 1 m in the lowlands. The same pattern can be seen on millennial time scales. Analysis of Holocene lake-core records indicates that Moody Lake, located near the outlet of the Crow Wing watershed, fell by as much as 4 m between about 4400 and 7000 yr BP. During the same time, water levels in Lake Mina, located near the upland watershed divide, fell by about 15 m. Reconstructed Holocene climate as represented by HYDRAT2D gives somewhat larger drops (6 and 24 m for Moody Lake and Lake Mina, respectively). The discrepancy is probably due to the effect of three-dimensional flow. A sensitivity analysis was also carried out to study how aquifer hydraulic conductivity and land-surface topography can influence water-table fluctuations, wetlands formation, and evapotranspiration. The models were run by recycling a wet year (1985, 87 cm annual precipitation) over a 10-year period followed by 20 years of drier and warmer climate (1976, 38 cm precipitation). Model results indicated that groundwater-supported evapotranspiration accounted for as much as 12% (10 cm) of evapotranspiration. The aquifers of highest hydraulic conductivity had the least amount of groundwater-supported evapotranspiration owing to a deep water table. Recharge

  13. The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

    DEFF Research Database (Denmark)

    Stewart, L.; Alsos, Inger G.; Bay, Christian

    2016-01-01

    correlated with each other, and both showed a positive relationship with landscape age. Plot species richness showed differing responses for vascular plants, bryophytes and lichens. At this finer scale, the richness of vascular plants was not significantly related to landscape age, which had a small effect...... size compared to the models of bryophyte and lichen richness. Main conclusion Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag...

  14. Application of surface-geophysical methods to investigations of sand and gravel aquifers in the glaciated Northeastern United States

    Science.gov (United States)

    Haeni, F.P.

    1995-01-01

    Combined use of seismic-refraction, direct-current resistivity, very-low-frequency terrain-resistivity, and inductive terrain-conductivity methods were demonstrated at sites in Connecticut, New York, and Maine. Although no single method can define both the hydrogeologic boundaries and general grain-size characteristics of sand and gravel aquifers, a combination of these methods can. Comparisons of measured electrical properties of aquifers with logs of test holes and wells indicate that, for a given conductivity of ground water, the bulk electrical resistivity of aquifers in the glaciated Northeast increases with grain size.

  15. Ice marginal fluctuations during the Weichselian glaciation in Fennoscandia, a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Lokrantz, Hanna; Sohlenius, Gustav [Geological Survey of Sweden, Uppsala (Sweden)

    2006-12-15

    This report presents an overview regarding ice marginal fluctuations during the last glacial, the Weichselian. It is focusing on marginal positions in Sweden with surroundings. The results are used to calibrate a computer simulation of the Weichselian ice sheet. The report also contains some information regarding basal conditions beneath the Swedish part of the Weichselian ice sheet. This information will be used to validate the results of the simulation of the Weichselian ice sheet. The Weichselian glaciation started 115 ka BP (thousands of years before present) and ended at the transition to the Holocene 11.5 ka BP. Terrestrial and marine records show that ice volumes fluctuated drastically during the Weichselian. The marine isotope record shows the global variations in climate and ice volume during the last ice age and has been divided into Marine Isotope Stages (MIS), which are well dated (MIS5d to MIS 2). Dating of terrestrial records is, however, problematic due to stratigraphical gaps and deposits, which are difficult to date. In many areas the timing of local and regional ice marginal fluctuations, prior to the Last Glacial Maximum (LGM), is therefore poorly understood. Age attribution of terrestrial deposits is often interpreted from bio- and litostratigraphical information, which has been correlated to other records, e.g. marine stratigraphies. The marine record from Early Weichselian (MIS 5d-5a) shows that two relatively warm periods, interstadials (MIS 5c and 5a), prevailed 105-9 ka BP and 85-74 ka BP. After MIS 5a global ice volume increased and remained large throughout Middle Weichselian (74-24 ka BP). During the LGM (c 21 ka BP), before the onset of the deglaciation, the ice volume was at its largest. Stratigraphical data indicate at least two periods with ice-free conditions in northern Fennoscandia, which have been correlated with the two early Weichselian interstadials Broerup and Odderade (MIS 5c and 5a). Few absolute dates have, however, been

  16. Ice marginal fluctuations during the Weichselian glaciation in Fennoscandia, a literature review

    International Nuclear Information System (INIS)

    Lokrantz, Hanna; Sohlenius, Gustav

    2006-12-01

    This report presents an overview regarding ice marginal fluctuations during the last glacial, the Weichselian. It is focusing on marginal positions in Sweden with surroundings. The results are used to calibrate a computer simulation of the Weichselian ice sheet. The report also contains some information regarding basal conditions beneath the Swedish part of the Weichselian ice sheet. This information will be used to validate the results of the simulation of the Weichselian ice sheet. The Weichselian glaciation started 115 ka BP (thousands of years before present) and ended at the transition to the Holocene 11.5 ka BP. Terrestrial and marine records show that ice volumes fluctuated drastically during the Weichselian. The marine isotope record shows the global variations in climate and ice volume during the last ice age and has been divided into Marine Isotope Stages (MIS), which are well dated (MIS5d to MIS 2). Dating of terrestrial records is, however, problematic due to stratigraphical gaps and deposits, which are difficult to date. In many areas the timing of local and regional ice marginal fluctuations, prior to the Last Glacial Maximum (LGM), is therefore poorly understood. Age attribution of terrestrial deposits is often interpreted from bio- and litostratigraphical information, which has been correlated to other records, e.g. marine stratigraphies. The marine record from Early Weichselian (MIS 5d-5a) shows that two relatively warm periods, interstadials (MIS 5c and 5a), prevailed 105-9 ka BP and 85-74 ka BP. After MIS 5a global ice volume increased and remained large throughout Middle Weichselian (74-24 ka BP). During the LGM (c 21 ka BP), before the onset of the deglaciation, the ice volume was at its largest. Stratigraphical data indicate at least two periods with ice-free conditions in northern Fennoscandia, which have been correlated with the two early Weichselian interstadials Broerup and Odderade (MIS 5c and 5a). Few absolute dates have, however, been

  17. IAA transport in corn roots includes the root cap

    International Nuclear Information System (INIS)

    Hasenstein, K.H.

    1989-01-01

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing 3 H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 μ1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 μ1 of sorbitol or the Ca 2+ chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap

  18. GPS scintillations associated with cusp dynamics and polar cap patches

    Directory of Open Access Journals (Sweden)

    Jin Yaqi

    2017-01-01

    Full Text Available This paper investigates the relative scintillation level associated with cusp dynamics (including precipitation, flow shears, etc. with and without the formation of polar cap patches around the cusp inflow region by the EISCAT Svalbard radar (ESR and two GPS scintillation receivers. A series of polar cap patches were observed by the ESR between 8:40 and 10:20 UT on December 3, 2011. The polar cap patches combined with the auroral dynamics were associated with a significantly higher GPS phase scintillation level (up to 0.6 rad than those observed for the other two alternatives, i.e., cusp dynamics without polar cap patches, and polar cap patches without cusp aurora. The cusp auroral dynamics without plasma patches were indeed related to GPS phase scintillations at a moderate level (up to 0.3 rad. The polar cap patches away from the active cusp were associated with sporadic and moderate GPS phase scintillations (up to 0.2 rad. The main conclusion is that the worst global navigation satellite system space weather events on the dayside occur when polar cap patches enter the polar cap and are subject to particle precipitation and flow shears, which is analogous to the nightside when polar cap patches exit the polar cap and enter the auroral oval.

  19. GPS scintillations associated with cusp dynamics and polar cap patches

    Science.gov (United States)

    Jin, Yaqi; Moen, Jøran I.; Oksavik, Kjellmar; Spicher, Andres; Clausen, Lasse B. N.; Miloch, Wojciech J.

    2017-10-01

    This paper investigates the relative scintillation level associated with cusp dynamics (including precipitation, flow shears, etc.) with and without the formation of polar cap patches around the cusp inflow region by the EISCAT Svalbard radar (ESR) and two GPS scintillation receivers. A series of polar cap patches were observed by the ESR between 8:40 and 10:20 UT on December 3, 2011. The polar cap patches combined with the auroral dynamics were associated with a significantly higher GPS phase scintillation level (up to 0.6 rad) than those observed for the other two alternatives, i.e., cusp dynamics without polar cap patches, and polar cap patches without cusp aurora. The cusp auroral dynamics without plasma patches were indeed related to GPS phase scintillations at a moderate level (up to 0.3 rad). The polar cap patches away from the active cusp were associated with sporadic and moderate GPS phase scintillations (up to 0.2 rad). The main conclusion is that the worst global navigation satellite system space weather events on the dayside occur when polar cap patches enter the polar cap and are subject to particle precipitation and flow shears, which is analogous to the nightside when polar cap patches exit the polar cap and enter the auroral oval.

  20. Polar cap deflation during magnetospheric substorms

    Science.gov (United States)

    Moses, J. J.; Siscoe, G. L.; Heelis, R. A.; Winningham, J. D.

    1989-01-01

    The expanding/contracting polar cap model has been used to simulate DE-2 ion drift data during substorms as determined using the AL index. Of the 39 cases modeled, 57 percent required the opening of a nightside gap which maps to where reconnection occurs in the tail; 75 percent of the 16 recovery phase cases required a nightside gap, while only 29 percent of the 17 expansion phase cases required a nightside gap. On the basis of this result, it is concluded that if a nightside gap implies tail reconnection, then reconnection probably occurs after expansion phase onset and continues throughout most of the recovery phase of a substorm.

  1. Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA

    Science.gov (United States)

    Rosenbaum, Joseph G.; Reynolds, Richard L.; Colman, Steven M.

    2012-01-01

    Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect glacial extent. The two areas are at similar latitudes and yield similar records of glacial growth and recession, even though UKL lies less than 200 km from the ocean and BL is in the continental interior. As sea level began to fall prior to the global Last Glacial Maximum (LGM), existing glaciers in the UKL area expanded. Near the beginning of the global LGM (26.5 ka), the BL record indicates onset of glaciation and UKL-area glaciers underwent further expansion. Both records indicate that local glaciers reached their maximum extents near the end of the global LGM, remained near their maxima for ~1000 yr, and underwent two stages of retreat separated by a short period of expansion.

  2. The impact of the Quaternary glaciations on the Durmitor mountains (Montenegro) as understood from detailed geomorphological mapping

    Science.gov (United States)

    Frankl, Amaury; Annys, Klaas; Spalević, Velibor; Čurović, Milic; Borota, Dragan; Nyssen, Jan

    2014-05-01

    In the Balkans, few studies exist that highlight the impact of the Quaternary glaciations on the landscape. However, the impact of the Quaternary glaciations was important and the glacial imprint remains well preserved in the limestone massifs where karst hydrology prevails. This study presents a detailed geomorphological map at scale 1:10,000 that was prepared of the northeastern Durmitor mountains (2523 m a.s.l.) and the plateau Jezerska Površ (47 km², Dinaric Alps, Montenegro). Mapping occurred from an intensive fieldwork campaign and remote sensing analysis, and was finalized in a GIS environment. The basic components of the legend are (i) processes/genesis, (ii) materials, (iii) morphometry/morphography, (iv) hydrography, (v) vegetation and (vi) anthropogenic features, that are organized as a box-of-bricks type of legend (AGRG-system). The geomorphological setting of the area consists of Mesozoic limestones which were eroded physically by Quaternary glacial and periglacial activity and chemically during interglacials. Glacial deposits of three Middle to Late Pleistocene glacial phases exist on the plateau, only scarcely dissected by meltwater channels. In the mountains, Holocene glacier retreat left behind a series of well-preserved recessional moraines and a static glacier remains in the cirque head. The presented map serves as a valuable tool for Quaternary research in the Durmitor Mountains, and serves as an example on the interaction between glacial and karst processes. Keywords: Debeli Namet glacier, Dinaric Alps, Geographic Information System (GIS), Glacial landforms, Karst.

  3. EVOLUTION OF THE ELBRUS GLACIATION SINCE THE MID XIX CENTURY UNDER CHANGING CLIMATE. KEY FINDINGS OF THE GLACIO-CARTOGRAPHICAL MONITORING

    Directory of Open Access Journals (Sweden)

    Yevgeniy Zolotarev

    2010-01-01

    Full Text Available Changes in the area and volume that have been occurring from the middle of the XIX century within the largest in Europe Elbrus glaciation were studied using lichenometry and digital cartography methods. There were cyclical, approximately 55 years long, frontal fluctuations of glaciers Bolshoi Azau (the largest Elbrus glacier and Dzhankuat (which is representative of all Central Caucasus glaciation. Quantitative data on changes in the area and volume of the Elbrus glaciation indicated that the greatest rates of its retreat coincided with the 1850–1887 period. Beginning in 1887, the area reduction was occurring practically evenly through time while the decrease in its volume has even slowed down. These facts suggest that global climate warming, which alternated with short-term cooling periods, began in the middle of the XIX century after the end of the Little Ice Age. The warming was most likely due to natural rather than anthropogenic causes.

  4. Contemporary suspended sediment yield of a partly glaciated catchment, Riffler Bach (Tyrol, Austria)

    Science.gov (United States)

    Weber, Martin; Baewert, Henning; Morche, David

    2015-04-01

    Due to glacier retreat since the LIA (Little Ice Age) proglacial areas in high mountain landscapes are growing. These systems are characterized by a high geomorphological activity, especially in the fluvial subsystem. Despite the long tradition of geomorphological research in the European Alps there is a still a lack of understanding in the interactions between hydrology, sediment sources, sediments sinks and suspended sediment transport. As emphasized by ORWIN ET AL. (2010) those problems can be solved by gathering data in a higher frequency and/or in a higher spatial resolution or density - both leading to a big amount of data. In 2012 a gauging station was installed at the outlet of the partly glaciated catchment of the Riffler Bach (Kaunertal valley, Tyrol). During the ablation seasons in 2012 and 2013 water stage was logged automatically every 15 minutes. In both seasons discharge was measured at different water levels to calculate a stage-discharge relation. Additionally, water samples were taken by an automatic water sampler. Within 16 sampling cycles with sampling frequencies ranging from 1 to 24 hours 389 water samples have been collected. The samples were filtered to calculate the suspended sediment concentration (SSC) of each sample. Furthermore, the climate station Weißsee provided meteorological data at a 15 minute interval. Due to the high variability in suspended sediment transport in proglacial rivers it is impossible to compute a robust annual Q-SSC-relation. Hence, two other approaches were used to calculate the suspended sediment load (SSL) and the suspended sediment yield (SSY): A) Q-SSC-relations for every single sampling cycle (e.g. GEILHAUSEN ET AL. 2013) B) Q-SSC-relations based on classification of dominant runoff-generating processes (e.g. ORWIN AND SMART 2004). The first approach uses commonly operated analysis methods that are well understood. While the hydro-climatic approach is more feasible to explain discharge generation and to

  5. Macrophage Capping Protein CapG Is a Putative Oncogene Involved in Migration and Invasiveness in Ovarian Carcinoma

    Directory of Open Access Journals (Sweden)

    J. Glaser

    2014-01-01

    Full Text Available The actin binding protein CapG modulates cell motility by interacting with the cytoskeleton. CapG is associated with tumor progression in different nongynecologic tumor entities and overexpression in breast cancer cell lines correlates with a more invasive phenotype in vitro. Here, we report a significant CapG overexpression in 18/47 (38% of ovarian carcinomas (OC analyzed by qRealTime-PCR analyses. Functional analyses in OC cell lines through siRNA mediated CapG knockdown and CapG overexpression showed CapG-dependent cell migration and invasiveness. A single nucleotide polymorphism rs6886 inside the CapG gene was identified, affecting a CapG phosphorylation site and thus potentially modifying CapG function. The minor allele frequency (MAF of SNP rs6886 (c.1004A/G was higher and the homozygous (A/A, His335 genotype was significantly more prevalent in patients with fallopian tube carcinomas (50% as in controls (10%. With OC being one of the most lethal cancer diseases, the detection of novel biomarkers such as CapG could reveal new diagnostic and therapeutic targets. Moreover, in-depth analyses of SNP rs6886 related to FTC and OC will contribute to a better understanding of carcinogenesis and progression of OC.

  6. MFTF-. cap alpha. + T progress report

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, W.D. (ed.)

    1985-04-01

    Early in FY 1983, several upgrades of the Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory (LLNL) were proposed to the fusion community. The one most favorably received was designated MFTF-..cap alpha..+T. The engineering design of this device, guided by LLNL, has been a principal activity of the Fusion Engineering Design Center during FY 1983. This interim progress report represents a snapshot of the device design, which was begun in FY 1983 and will continue for several years. The report is organized as a complete design description. Because it is an interim report, some parts are incomplete; they will be supplied as the design study proceeds. As described in this report, MFTF-..cap alpha..+T uses existing facilities, many MFTF-B components, and a number of innovations to improve on the physics parameters of MFTF-B. It burns deuterium-tritium and has a central-cell Q of 2, a wall loading GAMMA/sub n/ of 2 MW/m/sup 2/ (with a central-cell insert module), and an availability of 10%. The machine is fully shielded, allows hands-on maintenance of components outside the vacuum vessel 24 h after shutdown, and has provisions for repair of all operating components.

  7. Acoustic Monitoring of the Arctic Ice Cap

    Science.gov (United States)

    Porter, D. L.; Goemmer, S. A.; Chayes, D. N.

    2012-12-01

    Introduction The monitoring of the Arctic Ice Cap is important economically, tactically, and strategically. In the scenario of ice cap retreat, new paths of commerce open, e.g. waterways from Northern Europe to the Far East. Where ship-going commerce is conducted, the U.S. Navy and U.S. Coast Guard have always stood guard and been prepared to assist from acts of nature and of man. It is imperative that in addition to measuring the ice from satellites, e.g. Icesat, that we have an ability to measure the ice extent, its thickness, and roughness. These parameters play an important part in the modeling of the ice and the processes that control its growth or shrinking and its thickness. The proposed system consists of three subsystems. The first subsystem is an acoustic source, the second is an array of geophones and the third is a system to supply energy and transmit the results back to the analysis laboratory. The subsystems are described below. We conclude with a plan on how to tackle this project and the payoff to the ice cap modeler and hence the users, i.e. commerce and defense. System Two historically tested methods to generate a large amplitude multi-frequency sound source include explosives and air guns. A new method developed and tested by the University of Texas, ARL is a combustive Sound Source [Wilson, et al., 1995]. The combustive sound source is a submerged combustion chamber that is filled with the byproducts of the electrolysis of sea water, i.e. Hydrogen and Oxygen, an explosive mixture which is ignited via a spark. Thus, no additional compressors, gases, or explosives need to be transported to the Arctic to generate an acoustic pulse capable of the sediment and the ice. The second subsystem would be geophones capable of listening in the O(10 Hz) range and transmitting that data back to the laboratory. Thus two single arrays of geophones arranged orthogonal to each other with a range of 1000's of kilometers and a combustive sound source where the two

  8. Preform spar cap for a wind turbine rotor blade

    Science.gov (United States)

    Livingston, Jamie T [Simpsonville, SC; Driver, Howard D [Greer, SC; van Breugel, Sjef [Enschede, NL; Jenkins, Thomas B [Cantonment, FL; Bakhuis, Jan Willem [Nijverdal, NL; Billen, Andrew J [Daarlerveen, NL; Riahi, Amir [Pensacola, FL

    2011-07-12

    A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

  9. Lowering the YE+1 end-cap for CMS

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    On 9 January 2007, the massive YE+1 end-cap was lowered into the CMS cavern. This is a very precise process as the crane must lower the end-cap through minimal clearance without tilt or sway. Once in the cavern, the end-cap is then positioned over the end of the barrel to detect particles produced in collisions that travel close to the axis of the beams.

  10. Increased 5. cap alpha. -reductase activity in idiopathic hirsutism

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, P.; Lobo, R.A.

    1985-01-01

    In vitro, genital skin 5..cap alpha..-reductase activity (5..cap alpha..-RA) was measured in ten hirsute women with normal androgen levels (idiopathic hirsutism (IH)) and in ten hirsute women with elevated androgen levels (polycystic ovary syndrome (PCO)) in order to determine the influence of secreted androgens on 5..cap alpha..-RA. In vitro 5..cap alpha..-RA was assessed by incubations of skin with /sup 14/C-testosterone (T) for 2 hours, after which steroids were separated and the radioactivity of dihydrotestosterone (DHT) and 5..cap alpha..-androstane 3..cap alpha..-17..beta..-estradiol (3..cap alpha..-diol) in specific eluates were determined. All androgens were normal in IH with the exception of higher levels of 3..cap alpha..-diol glucuronide which were similar to the levels of PCO. The conversion ratio (CR) of T to DHT in IH and PCO were similar, yet significantly greater than the CR of control subjects. The CR of T to 3..cap alpha..-diol in IH and PCO were similar, yet higher than in control subjects. Serum androgens showed no correlation with 5..cap alpha..-RA, while the CR of T to DHT showed a significant positive correlation with the Ferriman and Gallwey score. The increased 5..cap alpha..-RA in IH appears to be independent of serum androgen levels and is, therefore, an inherent abnormality. The term idiopathic is a misnomer, because hirsutism in these patients may be explained on the basis of increased skin 5..cap alpha..-RA.

  11. Capped bit patterned media for high density magnetic recording

    Science.gov (United States)

    Li, Shaojing; Livshitz, Boris; Bertram, H. Neal; Inomata, Akihiro; Fullerton, Eric E.; Lomakin, Vitaliy

    2009-04-01

    A capped composite patterned medium design is described which comprises an array of hard elements exchange coupled to a continuous cap layer. The role of the cap layer is to lower the write field of the individual hard element and introduce ferromagnetic exchange interactions between hard elements to compensate the magnetostatic interactions. Modeling results show significant reduction in the reversal field distributions caused by the magnetization states in the array which is important to prevent bit errors and increase achievable recording densities.

  12. Management of community acquired pneumonia (CAP) in children ...

    African Journals Online (AJOL)

    2015-06-04

    ADV). Human metapneumovirus. Measles virus c. Others. Mycobacterium spp. Pneumocystis jiroveci. Globally, the common pathogens of CAP and the corre- sponding paediatric population are: General population of children.

  13. The CAP Theorem Versus Databases with Relaxed ACID properties

    DEFF Research Database (Denmark)

    Frank, Lars; Ulslev Pedersen, Rasmus; Frank, Christian Havnø

    2014-01-01

    The CAP theorem combines the three desirable properties C (data consistency), A (data availability), and P (partition-tolerance: tolerance of inconsistencies between data stored in a distributed database where partitions are allowed). The CAP theorem asserts that any distributed system that uses ...... data from different locations can have at most two of the three desirable CAP properties [5]. The NoSQL movement has applied the CAP theorem as an argument against traditional ACID (atomicity, consistency, isolation, and durability) databases, which prioritize consistency and partition...

  14. Biochemical principles and inhibitors to interfere with viral capping pathways.

    Science.gov (United States)

    Decroly, Etienne; Canard, Bruno

    2017-06-01

    Messenger RNAs are decorated by a cap structure, which is essential for their translation into proteins. Many viruses have developed strategies in order to cap their mRNAs. The cap is either synthetized by a subset of viral or cellular enzymes, or stolen from capped cellular mRNAs by viral endonucleases ('cap-snatching'). Reverse genetic studies provide evidence that inhibition of viral enzymes belonging to the capping pathway leads to inhibition of virus replication. The replication defect results from reduced protein synthesis as well as from detection of incompletely capped RNAs by cellular innate immunity sensors. Thus, it is now admitted that capping enzymes are validated antiviral targets, as their inhibition will support an antiviral response in addition to the attenuation of viral mRNA translation. In this review, we describe the different viral enzymes involved in mRNA capping together with relevant inhibitors, and their biochemical features useful in inhibitor discovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. NAMMA CLOUD MICROPHYSICS (CAPS-PIP) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cloud Microphysics dataset consists of particle size distributions from the Clouds, Aerosol and Preciptaition Spectrometer (CAPS) and the Precipitaiton Imaging...

  16. Who's (Still) Above the Social Security Payroll Tax Cap?

    OpenAIRE

    Nicole Woo; Janelle Jones; John Schmitt

    2012-01-01

    The Social Security payroll tax cap is the earnings level above which no further Social Security taxes are collected. The cap is currently at $110,100, though legislation has been introduced in Congress to apply the Social Security payroll tax to earnings above $250,000 (but not between the current cap and this level). This issue brief updates earlier work, finding that 5.8 percent of workers would be affected if the Social Security cap were eliminated entirely and 1.4 percent would be affect...

  17. THE TURN OF THE MONTH EFFECT CONTINUED: A COMPARISON OF SMALL CAP STOCKS AND LARGE CAP STOCKS

    OpenAIRE

    Ramsundhar, Shamman

    2010-01-01

    The purpose of this paper is to investigate whether the turn of the month effect occurs in small cap and large cap stocks and if it occurs in both categories, to determine whether there is a difference in the magnitude. My research, for the period of 1963-2008, based on the CRSP value weighted index, shows that there is a significant turn of the month effect in small and large cap stocks, however the effect is larger in small cap stocks. Furthermore, this effect is not limited to a short time...

  18. Alternate cap designs under RCRA regulations

    International Nuclear Information System (INIS)

    Manrod, W.E. III; Yager, R.E.; Craig, P.M.

    1988-01-01

    Low-level radioactive waste and mixed wastes have been disposed of in several sites in the vicinity of the Oak Ridge Y-12 Plant in Tennessee. Most of these materials have been placed in shallow land burial pits (SLB). Closure plans have been developed and approved by appropriate regulatory agencies for several of these sites. A variety of cap (final cover) designs for closure of these sites were investigated to determine their ability to inhibit infiltration of precipitation to the waste. The most effective designs are those that use synthetic materials as drainage layers and/or impermeable liners. The more complex, multi-layer systems perform no better than simpler covers and would complicate construction and increase costs. Despite the successful analytical results described in this paper, additional considerations must be factored into use of geosynthetic as well as natural materials

  19. Glaciers and ice caps outside Greenland

    Science.gov (United States)

    Sharp, Marin; Wolken, G.; Burgess, D.; Cogley, J.G.; Copland, L.; Thomson, L.; Arendt, A.; Wouters, B.; Kohler, J.; Andreassen, L.M.; O'Neel, Shad; Pelto, M.

    2015-01-01

    Mountain glaciers and ice caps cover an area of over 400 000 km2 in the Arctic, and are a major influence on global sea level (Gardner et al. 2011, 2013; Jacob et al. 2012). They gain mass by snow accumulation and lose mass by meltwater runoff. Where they terminate in water (ocean or lake), they also lose mass by iceberg calving. The climatic mass balance (Bclim, the difference between annual snow accumulation and annual meltwater runoff) is a widely used index of how glaciers respond to climate variability and change. The total mass balance (ΔM) is defined as the difference between annual snow accumulation and annual mass losses (by iceberg calving plus runoff).

  20. Cytocompatibility and Antibacterial Properties of Capping Materials

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2014-01-01

    Full Text Available The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply, Calcicur (Voco, Calcimol LC (Voco, TheraCal LC (Bisco, MTA Angelus (Angelus, and Biodentine (Septodont. To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity.

  1. Cytocompatibility and Antibacterial Properties of Capping Materials

    Science.gov (United States)

    Arciola, Carla Renata; Monaco, Annachiara; Lombardini, Marco

    2014-01-01

    The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity. PMID:24959601

  2. Response of Eyjafjallajökull, Torfajökull and Tindfjallajökull ice caps in Iceland to regional warming, deduced by remote sensing

    DEFF Research Database (Denmark)

    Gudmundsson, Sverrir; Björnsson, Helgi; Magnússon, Eyjólfur

    2011-01-01

    We assess the volume change and mass balance of three ice caps in southern Iceland for two periods, 1979–1984 to 1998 and 1998 to 2004, by comparing digital elevation models (DEMs). The ice caps are Eyjafjallajökull (ca. 81 km2), Tindfjallajökull (ca. 15 km2) and Torfajökull (ca. 14 km2). The DEMs...... as a reference map for co-registration and correction of the vertical offset of the other DEMs. The average specific mass balance was estimated from the mean elevation difference between glaciated areas of the DEMs. The glacier mass balance declined significantly between the two periods: from −0.2 to 0.2 m yr−1...... w. eq. during the earlier period (1980s through 1998) to −1.8 to −1.5 m yr−1 w. eq. for the more recent period (1998–2004). The declining mass balance is consistent with increased temperature over the two periods. The low mass balance and the small accumulation area ratio of Tindfjallajökull...

  3. Cap buckling as a potential mechanism of atherosclerotic plaque vulnerability.

    Science.gov (United States)

    Abdelali, Maria; Reiter, Steven; Mongrain, Rosaire; Bertrand, Michel; L'Allier, Philippe L; Kritikou, Ekaterini A; Tardif, Jean-Claude

    2014-04-01

    Plaque rupture in atherosclerosis is the primary cause of potentially deadly coronary events, yet about 40% of ruptures occur away from the plaque cap shoulders and cannot be fully explained with the current biomechanical theories. Here, cap buckling is considered as a potential destabilizing factor which increases the propensity of the atherosclerotic plaque to rupture and which may also explain plaque failure away from the cap shoulders. To investigate this phenomenon, quasistatic 2D finite element simulations are performed, considering the salient geometrical and nonlinear material properties of diverse atherosclerotic plaques over the range of physiological loads. The numerical results indicate that buckling may displace the location of the peak von Mises stresses in the deflected caps. Plaque buckling, together with its deleterious effects is further observed experimentally in plaque caps using a physical model of deformable mock coronary arteries with fibroatheroma. Moreover, an analytical approach combining quasistatic equilibrium equations with the Navier-Bresse formulas is used to demonstrate the buckling potential of a simplified arched slender cap under intraluminal pressure and supported by foundations. This analysis shows that plaque caps - calcified, fibrotic or cellular - may buckle in specific undulated shapes once submitted to critical loads. Finally, a preliminary analysis of intravascular ultrasonography recordings of patients with atherosclerotic coronary arteries corroborates the numerical, experimental and theoretical findings and shows that various plaque caps buckle in vivo. By displacing the sites of high stresses in the plaque cap, buckling may explain the atherosclerotic plaque cap rupture at various locations, including cap shoulders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Influence of Late Paleozoic Gondwana glaciations on the depositional evolution of the northern Pangean shelf, North Greenland, Svalbard and the Barents Sea

    DEFF Research Database (Denmark)

    Stemmerik, Lars

    2008-01-01

    Outcrop and subsurface data from the central northern margin of the Pangean shelf in North Greenland, Svalbard, and the Norwegian Barents Sea record the depositional response of a Northern Hemisphere subtropical shelf to Late Carboniferous-Early Permian (Bashkirian-Sakmarian) Gondwana glaciations...

  5. Spatial organization of process domains in headwater drainage basins of a glaciated foothills region with complex longitudinal profiles

    Science.gov (United States)

    McCleary, Richard J.; Hassan, Marwan A.; Miller, Dan; Moore, R. D.

    2011-05-01

    Lithologic transitions and glaciations create complex longitudinal profiles that control contemporary erosion and deposition processes. In areas with these characteristics, traditional morphometric approaches for predicting process domains, such as area-slope plots, can be augmented by considering other predictors measured from high resolution lidar-derived digital elevation models (DEMs). Ordinal logistic regression was used to model the distribution of hillslope, swale, colluvial channel, and fluvial channel domains, as identified during field surveys. The study area was a glaciated region of the Rocky Mountain foothills with a complex lithostructural setting. Relationships between domains and a suite of geographic information system-derived descriptors were explored. Predictors included profile anomalies measured at the reach and basin scale using a normalized stream length-gradient (SL/k) index. Drainage area was the dominant factor controlling domains. A model with area as the only predictor was 82% accurate. Reach slope relations were not consistent. A model that also included lithology and basin-scale SL/k index variation was 87% accurate. Domain transitions had larger area thresholds in basins with resistant conglomerate versus sandstone or shale formations and where SL/k index was more variable along a profile. In a restricted model of hillslope, swale, and colluvial channel domains, profile curvature measured over 100 m was also related to domain occurrence. A model for regional-scale mapping applications with six additional predictors was 95% accurate. The results showed that ordinal logistic regression can be used to predict and map process domains in regions with complex physiography using descriptors measured from high -resolution DEMs.

  6. A wireless partially glaciated watershed in a virtual globe: Integrating data, models, and visualization to increase climate change understanding

    Science.gov (United States)

    Jones, J.; Hood, E.; Fatland, D. R.; Berner, L.; Heavner, M.; Connor, C.; O'Brien, W.

    2008-12-01

    SEAMONSTER, a NASA funded sensor web project, is the SouthEast Alaska MOnitoring Network for Science, Telecommunications, Education and Research. SEAMONSTER is operating in the partially glaciated Mendenhall and Lemon Creek Watersheds, in the Juneau area, on the margins of the Juneau Icefield. These watersheds are studied for both 1. long term monitoring of changes, and 2. detection and analysis of transient events (such as glacier lake outburst floods). The diverse sensors (meteorological, dual frequency GPS, water quality, lake level, etc), power and bandwidth constraints, and competing time scales of interest require autonomous reactivity of the sensor web. The sensors are deployed throughout two partially glaciated watersheds and facilitated data acquisition in temperate rain forest, alpine, lacustrine, and glacial environments. Understanding these environments is important for public understanding of climate change. These environments are geographically isolated, limiting public access to, and understanding of, such locales. In an effort to inform the general public and primary educators about the basic processes occurring in these unique natural systems, we have developed an interactive website. This web portal supplements and enhances environmental science primary education by providing educators and students with interactive access to basic information from the glaciological, hydrological, and meteorological systems we are studying. In addition, we have developed an interactive virtual tour of the Lemon Glacier and its watershed. The focus of this presentation is using the data gathered by the SEAMONSTER sensor web, coupled with a temperature-indexed glacial melt model, to educate students and the public on topics ranging from modeling responses due to environmental changes to glacial hydrology. The interactive SEAMONSTER web site is the primary source for visualizing the data, while Google Earth can be used to visualize the isolated Lemon Creek watershed

  7. Genetic and morphological consequences of Quaternary glaciations: A relic barbel lineage (Luciobarbus pallaryi, Cyprinidae) of Guir Basin (Algeria).

    Science.gov (United States)

    Brahimi, Amina; Tarai, Nacer; Benhassane, Abdelkrim; Henrard, Arnaud; Libois, Roland

    2016-02-01

    Climatic variations during the Quaternary period had a considerable impact on landscapes and habitat fragmentation (rivers) in North Africa. These historical events can have significant consequences on the genetic structure of the populations. Indeed, geographically separated and genetically isolated populations tend to differentiate themselves through time, eventually becoming distinct lineages, allowing new species to emerge in later generations. The aim of the present study is to use genetic and morphological techniques to evaluate the major role of the Saalian glaciation (Middle Quaternary) in the establishment of the geographic space and in the evolution of the intraspecific genetic diversity, by tracing the demographic history of barbels belonging to the Luciobarbus pallaryi (Cyprinidae) species in the Guir Basin (Algeria). In this context, two populations, from two distinct and isolated sites, were studied. Analysis of the cytochrome b (cyt b) mitochondrial markers and of the "D-loop" control region has shown that the "upstream" and "downstream" Guir populations are genetically differentiated. The molecular analyses suggest that the upstream population was disconnected from this hydrographic system during the Saalian glaciation period of the Quaternary. Subsequently, it was isolated in the foggaras underground waters in the Great Western Erg, at approximately 320 000 years BP, creating, through a bottleneck effect, a new allopatric lineage referred to as "Adrar". Conversely, the high genetic diversity in the upstream Guir (Bechar) population suggests that the stock is globally in expansion. These barbels (n=52) were also examined with meristic, morphometric, osteological, and biological features. These data also reveal a complete discrimination between the two populations, with a remarkable and distinctive behavioural adaptation for the Adrar specimens: neoteny. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  8. Analyses of Current And Wave Forces on Velocity Caps

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Buhrkall, Jeppe; Eskesen, Mark C. D.

    2015-01-01

    ) this paper investigates the current and wave forces on the velocity cap and the vertical cylinder. The Morison’s force model was used in the analyses of the extracted force time series in from the CFD model. Further the distribution of the inlet velocities around the velocity cap was also analyzed in detail...

  9. Assembling Modules to the End-cap SCT Discs

    CERN Document Server

    Jackson, JN; Sutcliffe, P

    2002-01-01

    A major step in the construction of the SCT end-caps is the process of mounting the modules onto the discs and testing them. This note contains a description of the proposed assembly procedure and the design of the necessary jig to assemble inner, middle, and outer modules to the end-cap disc structure. Results obtained using prototype jigs are described.

  10. Preparing an ATLAS toroid magnet end-cap for lowering

    CERN Multimedia

    Claudia Marcelloni

    2007-01-01

    One of the two 13-m high toroid magnet end-caps for the ATLAS experiment being transported from the construction hall to the experimental area. The end-cap will be lowered into the ATLAS cavern and attached to an end of the detector.

  11. ATLAS end-caps 
on the move

    CERN Document Server

    2007-01-01

    Two delicate and spectacular transport operations have been performed for ATLAS in recent weeks: the first end-cap tracker was installed in its final position, and one of the huge end-caps of the toroid magnet was moved to the top of the experiment’s shaft.

  12. 20 CFR 606.20 - Cap on tax credit reduction.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Cap on tax credit reduction. 606.20 Section 606.20 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TAX CREDITS... Tax Credit Reduction § 606.20 Cap on tax credit reduction. (a) Applicability. Subsection (f) of...

  13. An historical look at a contemporary question: the cervical cap.

    Science.gov (United States)

    Zimmet, J A; Reagan, P A

    1986-01-01

    The cervical cap was most likely invented during the 19th century and was rediscovered in 1908 by a Viennese physician. The cap was always more popular in Europe than in the US, and the introduction of oral contraceptives and the IUD in the 1960s led to a declining interest in barrier methods. In 1977, the US Food and Drug Administration banned distribution of the cervical cap, presumably in reaction to outbreaks of toxic shock syndrome and despite rising interest in the device on the part of the woman's health movement. It is important for health educators to be informed about empirical research about the cervical cap so that they can counsel consumers in the event that the device is reclassified for general use. Acceptor studies have identified convenience, safety, spontaneity, and comfort as reasons for selecting the cervical cap, while difficult insertion and removal, odor, partner discomfort, and uncertainty about contraceptive effectiveness are cited as reasons for disliking this device. Dislodgement has been a major problem, experienced by almost half of cap acceptors at some point. Discontinuation rates after 6 months of use have been in the 25-40% range. No cases of pelvic inflammatory disease or significant cervical pathology have been recorded. The unplanned pregnancy rate associated with the cervical cap has been estimated to be about 8%. Omission of spermicide, dislodgement, faulty technique, and irregular usage account for most of these failures. There is a need for additional research addressing the issues and documenting the limits of safe cervical cap use.

  14. A simplified model of polar cap electric fields

    International Nuclear Information System (INIS)

    D'Angelo, N.

    1977-01-01

    A simple-minded 'model' is used in order to visualize the gross features of polar cap electric fields, in particular the 'diode' effect which had emerged already from earlier observations and the asymmetry between the electric fields observed on the dawn and dusk sides of the polar cap, which depends on Bsub(y)

  15. Effect of capping agents on optical and antibacterial properties of ...

    Indian Academy of Sciences (India)

    Administrator

    nature of capping agents. The QDs have been characterized by Fourier-transform infrared spectroscopy, atomic absorption spectroscopy and transmission electron microscopy. Further, antimicrobial activity of as-prepared QDs has also been investigated using the disk diffusion method. Keywords. Capping agents; quantum ...

  16. Progress in LAr EndCap Calorimetry: News from the Hadronic EndCap Group.

    CERN Multimedia

    Oram, C.J.

    With module production and testing completed for the Hadronic EndCap calorimeter, the attention of the HEC group is heavily directed towards wheel assembly in building 180. Three of the four HEC wheels are now assembled and rotated, and work is progressing on assembling the final wheel. This year has been a busy year for the installation of components in the EndCap C cryostat: the signal feedthrough installation was completed April 22nd, the pre-sampler shortly thereafter and the Electro-Magnetic EndCap August 13th. This allowed the HEC group to start transferring the HEC wheels from the T6A storage cradle into the cryostat. The operation started in mid-September and has progressed, on or ahead of schedule, since then with the major milestones being: Insertion of 67 ton front HEC wheel October 3rd Insertion of 90 ton rear HEC wheel October 22nd. The wheel alignment has proved to be excellent, with the position of the centre of the front(rear) wheel with respect to the nominal position being displaced b...

  17. Capping protein binding to S100B: implications for the tentacle model for capping the actin filament barbed end.

    Science.gov (United States)

    Wear, Martin A; Cooper, John A

    2004-04-02

    S100B binds tightly to a 12-amino acid peptide derived from heterodimeric capping protein. In native intact capping protein, this sequence is in the C terminus of the alpha-subunit, which is important for capping the actin filament. This C-terminal region is proposed to act as a flexible "tentacle," extending away from the body of capping protein in order to bind actin. To this hypothesis, we analyzed the interaction between S100B and capping protein in solution. The C-terminal 28 amino acids of the alpha-subunit, the proposed tentacle, bound to S100B as a free synthetic peptide or a glutathione S-transferase fusion (K(d) approximately 0.4-1 microm). In contrast, S100B did not bind to whole native capping protein or functionally affect its capping activity. S100B does not bind, with any significant affinity, to the proposed alpha-tentacle sequence of whole native capping protein in solution. In the NMR structure of S100B complexed with the alpha-subunit-derived 12-amino acid peptide, the hydrophobic side of a short alpha-helix in the peptide, containing an important tryptophan residue, contacts S100B. In the x-ray structure of native capping protein, the corresponding sequence of the alpha-subunit C terminus, including Trp(271), interacts closely with the body of the protein. Therefore, our results suggest the alpha-subunit C terminus is not mobile as predicted by the tentacle model. Addition of non-ionic detergent allowed whole capping protein to bind weakly to S100B, indicating that the alpha-subunit C terminus can be mobilized from the surface of the capping protein molecule, presumably by weakening the hydrophobic binding at the contact site.

  18. Elevated CO2degassing rates prevented the return of Snowball Earth during the Phanerozoic.

    Science.gov (United States)

    Mills, Benjamin J W; Scotese, Christopher R; Walding, Nicholas G; Shields, Graham A; Lenton, Timothy M

    2017-10-24

    The Cryogenian period (~720-635 Ma) is marked by extensive Snowball Earth glaciations. These have previously been linked to CO 2 draw-down, but the severe cold climates of the Cryogenian have never been replicated during the Phanerozoic despite similar, and sometimes more dramatic changes to carbon sinks. Here we quantify the total CO 2 input rate, both by measuring the global length of subduction zones in plate tectonic reconstructions, and by sea-level inversion. Our results indicate that degassing rates were anomalously low during the Late Neoproterozoic, roughly doubled by the Early Phanerozoic, and remained comparatively high until the Cenozoic. Our carbon cycle modelling identifies the Cryogenian as a unique period during which low surface temperature was more easily achieved, and shows that the shift towards greater CO 2 input rates after the Cryogenian helped prevent severe glaciation during the Phanerozoic. Such a shift appears essential for the development of complex animal life.

  19. Phosphogypsum capping depth affects revegetation and hydrology in Western Canada.

    Science.gov (United States)

    Jackson, Mallory E; Naeth, M Anne; Chanasyk, David S; Nichol, Connie K

    2011-01-01

    Phosphogypsum (PG), a byproduct of phosphate fertilizer manufacturing, is commonly stacked and capped with soil at decommissioning. Shallow (0, 8, 15, and 30 cm) and thick (46 and 91 cm) sandy loam caps on a PG stack near Fort Saskatchewan, Alberta, Canada, were studied in relation to vegetation establishment and hydrologic properties. Plant response was evaluated over two growing seasons for redtop ( L.), slender wheatgrass ( (Link) Malte ex H.F. Lewis), tufted hairgrass ( (L.) P. Beauv.), and sheep fescue ( L.) and for a mix of these grasses with alsike clover ( L.). Water content below the soil-PG interface was monitored with time-domain reflectometry probes, and leachate water quantity and quality at a depth of 30 cm was measured using lysimeters. Vegetation responded positively to all cap depths relative to bare PG, with few significant differences among cap depths. Slender wheatgrass performed best, and tufted hairgrass performed poorly. Soil caps <1 m required by regulation were sufficient for early revegetation. Soil water fluctuated more in shallow than in thick caps, and water content was generally between field capacity and wilting point regardless of cap depth. Water quality was not affected by cap depths ≤30 cm. Leachate volumes at 30 cm from distinct rainfall events were independent of precipitation amount and cap depth. The study period had lower precipitation than normal, yet soil caps were hospitable for plant growth in the first 2 yr of establishment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  20. Weak hydrothermal carbonation of the Ongeluk volcanics: evidence for low CO2 concentrations in seawater and atmosphere during the Paleoproterozoic global glaciation

    Science.gov (United States)

    Shibuya, Takazo; Komiya, Tsuyoshi; Takai, Ken; Maruyama, Shigenori; Russell, Michael J.

    2017-12-01

    It was previously revealed that the total CO2 concentration in seawater decreased during the Late Archean. In this paper, to assess the secular change of total CO2 concentration in seawater, we focused on the Paleoproterozoic era when the Earth experienced its first recorded global glaciation. The 2.4 Ga Ongeluk Formation outcrops in the Kaapvaal Craton, South Africa. The formation consists mainly of submarine volcanic rocks that have erupted during the global glaciation. The undeformed lavas are mostly carbonate-free but contain rare disseminated calcites. The carbon isotope ratio of the disseminated calcite (δ13Ccc vs. VPDB) ranges from - 31.9 to - 13.2 ‰. The relatively low δ13Ccc values clearly indicate that the carbonation was partially contributed by 13C-depleted CO2 derived from decomposition of organic matter beneath the seafloor. The absence of δ13Ccc higher than - 13.2‰ is consistent with the exceptionally 13C-depleted CO2 in the Ongeluk seawater during glaciation. The results suggest that carbonation occurred during subseafloor hydrothermal circulation just after the eruption of the lavas. Previously, it was reported that the carbonate content in the uppermost subseafloor crust decreased from 3.2 to 2.6 Ga, indicating a decrease in total CO2 concentration in seawater during that time. However, the average CO2 (as carbonate) content in the Ongeluk lavas (extremely low CO2 concentration in seawater during the global glaciation. Considering that the carbonate content of the subseafloor crusts also shows a good correlation with independently estimated atmospheric pCO2 levels through the Earth history, it seem highly likely that the low carbonate content in the Ongeluk lavas reflects the low atmospheric pCO2 at that time. We conclude that the continuous decrease in CO2 concentration of seawater/atm. from 3.2 Ga was one of the contributing factors to the Paleoproterozoic global glaciation.

  1. Cap-preserving SMILE Enhancement Surgery.

    Science.gov (United States)

    Sedky, Ahmed N; Wahba, Sherine S; Roshdy, Maged M; Ayaad, Nermeen R

    2018-02-17

    Different enhancement procedures have been suggested for reduction of residual refractive errors after SMILE. The aim of this study is to evaluate an improved cap-preserving technique for enhancement after SMILE (Re-SMILE). A retrospective case series was conducted at Eye subspecialty center, Cairo, Egypt on 9 eyes with myopia or myopic astigmatism (spherical equivalent - 8.0 and - 12.0D). undergoing SMILE procedure and needed second interference. This was either because the more myopic meridian was more than - 10.0 D and therefore planned to have two-steps procedure (six eyes) or because of under correction needing enhancement (three eyes). Assessment after the primary SMILE procedure was conducted at 1 day, 1 week, 1 month and 3 months postoperatively. Assessment after Re-SMILE was conducted at 1 day, 1 week, 1 month, 3 months, 6 months and 1 year postoperatively. The assessments included full ophthalmic examination, objective and subjective refraction, and rotating Scheimpflug camera imaging. Preoperatively, the mean refractive spherical equivalent (MRSE) values were: - 9.36 ± 0. 89. After primary SMILE it was - 2.18 ± 0.71. After Re-SMILE it was - 0.13 ± 0.68. MRSE was significantly improved after both procedures (P < 0.01). The safety index of primary SMILE cases was 1.65 ± 0.62 and for Re-SMILE 1.13 ± 0.34 and the efficacy index was 1.14 ± 0.24 after primary SMILE and 1.11 ± 0.26 after Re-SMILE. Centered cap-preserving Re-SMILE is an effective procedure in reducing residual refractive errors after primary SMILE in high myopes.

  2. The influence of connecting pile cap-column in the mechanisms of break in the two pile caps

    Directory of Open Access Journals (Sweden)

    A. C. MESQUITA

    Full Text Available Abstract The paper analyzes the two pile caps with partially embedded socket and subject a center load. Three models were experimentally tested, varying the type of conformation of the column and walls of the socket, with a smooth, the other rough, and a monolithic two pile cap, used for reference. The roughening of the column-socket interface was examined with the aim of verifying the difference of the distribution of compressive and tensile stresses in the strut an tie model used for design. The experimental test to show that the two pile caps with conformation rough of the column and walls of the socket, support more load in comparison with two pile caps with smooth of the column and walls of the socket. Both however underperformed the monolithic two pile cap, with values of 66% and 36% respectively.

  3. Innovation under cap-and-trade programs.

    Science.gov (United States)

    Taylor, Margaret R

    2012-03-27

    Policies incentivizing the private sector to reach its innovative potential in "clean" technologies are likely to play a key role in achieving climate stabilization. This article explores the relationship between innovation and cap-and-trade programs (CTPs)--the world's most prominent climate policy instrument--through empirical evidence drawn from successful CTPs for sulfur dioxide and nitrogen oxide control. The article shows that before trading began for these CTPs, analysts overestimated the value of allowances in a pattern suggestive of the frequent a priori overestimation of the compliance costs of regulation. When lower-than-expected allowance prices were observed, in part because of the unexpected range of abatement approaches used in the lead-up to trading, emissions sources chose to bank allowances in significant numbers and reassess abatement approaches going forward. In addition, commercially oriented inventive activity declined for emissions-reducing technologies with a wide range of costs and technical characteristics, dropping from peaks before the establishment of CTPs to nadirs a few years into trading. This finding is consistent with innovators deciding during trading that their research and development investments should be reduced, based on assessments of future market conditions under the relevant CTPs. The article concludes with a discussion of the results and their implications for innovation and climate policy.

  4. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification.

    Science.gov (United States)

    Dixon, Derek R; Schweiger, Michael J; Riley, Brian J; Pokorny, Richard; Hrma, Pavel

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated profile generated by a cold-cap model that has been developed to assess the rate of glass production in a melter.

  5. ImmunoCAP assays: Pros and cons in allergology.

    Science.gov (United States)

    van Hage, Marianne; Hamsten, Carl; Valenta, Rudolf

    2017-10-01

    Allergen-specific IgE measurements and the clinical history are the cornerstones of allergy diagnosis. During the past decades, both characterization and standardization of allergen extracts and assay technology have improved. Here we discuss the uses, advantages, misinterpretations, and limitations of ImmunoCAP IgE assays (Thermo Fisher Scientific/Phadia, Uppsala, Sweden) in the field of allergology. They can be performed as singleplex (ImmunoCAP) and, for the last decade, as multiplex (Immuno Solid-phase Allergen Chip [ISAC]). The major benefit of ImmunoCAP is the obtained quantified allergen-specific IgE antibody level and the lack of interference from allergen-specific IgG antibodies. However, ImmunoCAP allergen extracts are limited to the composition of the extract. The introduction of allergen molecules has had a major effect on analytic specificity and allergy diagnosis. They are used in both singleplex ImmunoCAP and multiplex ImmunoCAP ISAC assays. The major advantage of ISAC is the comprehensive IgE pattern obtained with a minute amount of serum. The shortcomings are its semiquantitative measurements, lower linear range, and cost per assay. With respect to assay performance, ImmunoCAP allergen extracts are good screening tools, but allergen molecules dissect the IgE response on a molecular level and put allergy research on the map of precision medicine. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  6. Electrochemical synthesis and optical properties of organically capped silver nanoparticles

    International Nuclear Information System (INIS)

    Rabinal, M.K.; Kalasad, M.N.; Praveenkumar, K.; Bharadi, V.R.; Bhikshavartimath, A.M.

    2013-01-01

    Graphical abstract: A simple electrochemical method for the synthesis of organically capped silver nanoparticles by anodic dissolution of silver. Highlights: ► Electrochemical method has been developed to synthesize silver nanoparticles. ► The bulk silver is converted to monodispersed silver nanoparticles by anodic dissolution of metal. ► It permits in-situ capping of nanoparticles with suitable organic molecules. ► The method is simple, economical and greener in approach to prepare bulk quantity of stable sols of silver nanoparticles. -- Abstract: A top to bottom approach has been adopted to prepare silver nanoparticles by electrochemical dissolution of metal in suitable organic solvents. The method is being simple and economical, also permits in situ capping of nanoparticles with organic molecules. Thioglycolic acid is used as capping/stabilizing agent. Optical absorption, transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffraction measurements were carried out to study the effect of capping molecules on the size and shape of nanoparticles. It is found that thioglycolic acid is an effective capping agent and hence the resultant sol, even with high density of nanoparticles, is kinetically more stable. The present method can also be extended to synthesize other metal nanoparticles capped with various organic molecules

  7. Pulpal response to tricalcium phosphate as a capping agent.

    Science.gov (United States)

    Chohayeb, A A; Adrian, J C; Salamat, K

    1991-03-01

    The purpose of this study was to evaluate tricalcium phosphate (TCP) as a pulp-capping agent. Two adult male beagle dogs were used for this investigation. Class I cavities were prepared in the posterior teeth and Class V cavities in the anterior teeth. With the use of a rubber dam and high speed with water coolant, minimal pulp exposures were created in both the experimental and control teeth, by means of a 1/2 round bur. Zinc oxide-eugenol was the temporary filling material used to restore all cavities. In each dog, five teeth served as control and were capped with the use of calcium hydroxide. In one dog, 10 teeth from two quadrants were capped with the tested material (TCP). In the other dog, 11 teeth were capped with TCP. Four teeth from the fourth quadrant in each dog were capped with a mixture of calcium hydroxide and TCP in a ratio of 1:1 by weight (50/50 group.) The two dogs were killed after 70 days. The histologic evaluation of the response to the capping agents and at the exposure site was recorded. A total of 39 teeth were evaluated in this study. It was found that TCP as a capping agent precipitated the highest mean inflammatory response and also demonstrated the highest percentage of reparative dentin formation.

  8. Oxidation resistance of Ru-capped EUV multilayers

    Science.gov (United States)

    Bajt, Sasa; Dai, Zu Rong; Nelson, Erik J.; Wall, Mark A.; Alameda, Jennifer; Nguyen, Nhan; Baker, Sherry; Robinson, Jeffrey C.; Taylor, John S.; Clift, Miles; Aquila, Andy; Gullikson, Eric M.; Edwards, N. V. Ginger

    2005-05-01

    Differently prepared Ru-capping layers, deposited on Mo/Si EUV multilayers, have been characterized using a suite of metrologies to establish their baseline structural, optical, and surface properties in as-deposited state. The same capping layer structures were tested for their thermal stability and oxidation resistance. Post-mortem characterization identified changes due to accelerated tests. The best performing Ru-capping layer structure was studied in detail with transmission electron microscopy to identify the grain microstructure and texture. This information is essential for modeling and performance optimization of EUVL multilayers.

  9. Capítulo I: Contabilidad de costos - Capítulo II : Costos estimados

    OpenAIRE

    Rojas Medina, Ricardo Alfredo

    2014-01-01

    Me permito poner a su consideración los capítulos I y II del libro titulado: Costos un enfoque administrativo y de gerencia, contenido que fue realizado para mejorar y reestructurar el libro titulado Sistemas de costos un proceso para su implementación, que tuvo gran acogida dado el volumen de consulta y descarga del repositorio de la UN. En la primera unidad se trabaja lo referente a costos para la toma de decisiones, presentado un marco teórico y los fundamentos básicos del costeo direct...

  10. New U-Pb age constraints on the upper Banxi Group and synchrony of the Sturtian glaciation in South China

    Directory of Open Access Journals (Sweden)

    Gaoyuan Song

    2017-09-01

    -Sturtian strata in Oman and Canada. These ages indicate that the Jiangkou (Sturtian glaciation in South China started at ca. 715 Ma instead of ca. 780 Ma and support a globally synchronous initiation of the Sturtian glaciation at ca. 715 Ma.

  11. Multi-proxy geochemical evidence for primary aragonite precipitation in a tropical-shelf 'calcite sea' during the Hirnantian glaciation

    Science.gov (United States)

    Kimmig, Sara R.; Holmden, Chris

    2017-06-01

    A positive excursion in sedimentary δ26Mg values (2-3‰) is recorded in a mud dominated carbonate succession spanning the Hirnantian glaciation event in a tropical-shelf sea in Nevada. The increase is coincident with lithofacies and biofacies indicators of sea-level change, and previously reported changes in sedimentary δ13C and δ44/40Ca values in the same section. The synchronousness of the isotopic changes is inconsistent with differences in the oceanic residence times of Mg (13 Myr), Ca (0.5-1 Myr), and C (0.1 Myr), indicating that the isotopic trends cannot be attributed to perturbations in the oceanic cycling of these elements. Instead, a mixing analysis (δ26Mg vs. Ca/Mg) reveals that the stratigraphic shift in sedimentary δ26Mg values is an artifact of changing dolomite abundance in the carbonate succession, which increases by an average of ∼12 mol% during the glaciation. The mixing analysis also uncovers stratigraphic changes in end-member limestone δ26Mg values that are tentatively attributed to variations in aragonite abundance. The aragonite, which inverted to calcite during diagenesis, accumulated during the glacio-eustatically controlled sea-level lowstand in the study setting. Although this interpretation is vulnerable to diagenetic effects that are difficult to evaluate, it is strengthened by shifts to lower δ44/40Ca values and higher δ13C values in the same section. Experiments show that aragonite can precipitate in seawater with the chemistry of a 'calcite sea' at temperatures above 20-23 °C. Considering the warm climates of the early Paleozoic, temperatures above this range were likely common in low latitudes. This study shows that the isotopes of Mg, Ca, and C have the potential to fingerprint aragonite that has inverted to calcite in the rock record. It is important recognize carbonate successions where this has occurred so as to avoid misinterpreting facies-dependent changes in carbonate polymorph mineralogy as genuine records of

  12. Analyses of Current And Wave Forces on Velocity Caps

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Buhrkall, Jeppe; Eskesen, Mark C. D.

    2015-01-01

    leads the water into another pipe or tunnel system. A pressure gradient generated by the water level difference between the sea and basin drives the flow through the tunnel system. The tunnel system is often in the order of a couple kilometers long. Based on CFD analyses (computational fluid dynamics......Velocity caps are often used in connection with for instance offshore intake sea water for the use of for cooling water for power plants or as a source for desalinization plants. The intakes can also be used for river intakes. The velocity cap is placed on top of a vertical pipe. The vertical pipe......) this paper investigates the current and wave forces on the velocity cap and the vertical cylinder. The Morison’s force model was used in the analyses of the extracted force time series in from the CFD model. Further the distribution of the inlet velocities around the velocity cap was also analyzed in detail...

  13. Radical Scavenging Efficacy of Thiol Capped Silver Nanoparticles

    Indian Academy of Sciences (India)

    OH) ... nents involved in redox homeostasis. Nature of bonding ..... study provides valuable and fundamental information about the scavenging behavior of thiol capped AgNPs in biological system. Supplementary Information. All additional ...

  14. 2011 C-CAP Land Cover of Oahu, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  15. Wind blade spar cap and method of making

    Science.gov (United States)

    Mohamed, Mansour H [Raleigh, NC

    2008-05-27

    A wind blade spar cap for strengthening a wind blade including an integral, unitary three-dimensional woven material having a first end and a second end, corresponding to a root end of the blade and a tip end of the blade, wherein the material tapers in width from the first to the second end while maintaining a constant thickness and decreasing weight therebetween, the cap being capable of being affixed to the blade for providing increased strength with controlled variation in weight from the root end to the tip end based upon the tapered width of the material thereof. The present inventions also include the method of making the wind blade spar cap and a wind blade including the wind blade spar cap.

  16. Circumpolar Active-Layer Permafrost System (CAPS), Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Circumpolar Active-Layer Permafrost System (CAPS) contains over 100 data sets pertaining to permafrost and frozen ground topics. It also contains detailed...

  17. Evidence that polar cap arcs occur on open field lines

    International Nuclear Information System (INIS)

    Gussenhoven, M.S.; Hardy, D.A.; Rich, F.J.; Mullen, E.G.; Redus, R.H.

    1990-01-01

    The characteristics of polar cap arc occurrence are reviewed to show that the assumption of a closed magnetospheric magnetic field topology at very high latitudes when the IMF B z is strongly northward is difficult to reconcile with a wide variety of observational and theoretical considerations. In particular, we consider the implications of observations of particle entry for high and low energy electrons, magnetic flux conservation between the near and far tail, the time sequencing in polar cap arcs events, and the hemispherical differences in polar cap arc observations. These points can be explained either by excluding the need for a major topological magnetic field change from explanations of polar cap arc dynamics, or by assuming a long-tailed magnetosphere for all IMF orientations in which magnetic field lines eventually merge with solar wind field lines in either a smooth or a patchy fashion. (author)

  18. License - RGP caps | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available might be changed without notice. About This Database Database Description Download License Update History of This Database Site Policy | Contact Us License - RGP caps | LSDB Archive ...

  19. Impact of CAP Direct Payments on French Farms’ Managerial Efficiency

    OpenAIRE

    Latruffe, Laure; Guyomard, Herve; Le Mouel, Chantal

    2008-01-01

    This paper investigates the relationship between CAP direct payments and managerial efficiency for French crop and beef farms. Managerial efficiency scores are calculated using a four-step approach that allows disentangling managerial inefficiency from other technical inefficiency components, notably what is due to unfavourable environment conditions. Then managerial efficiency scores are regressed over a set of explanatory variables, including CAP direct payments. Our empirical application, ...

  20. In vitro antibacterial activity of different pulp capping materials

    OpenAIRE

    Poggio, Claudio; Beltrami, Riccardo; Colombo, Marco; Ceci, Matteo; Dagna, Alberto; Chiesa, Marco

    2015-01-01

    Background Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC...

  1. The General Design and Technology Innovations of CAP1400

    OpenAIRE

    Zheng, Mingguang; Yan, Jinquan; Jun, Shentu; Tian, Lin; Wang, Xujia; Qiu, Zhongming

    2017-01-01

    The pressurized water reactor CAP1400 is one of the sixteen National Science and Technology Major Projects. Developed from China's nuclear R&D system and manufacturing capability, as well as AP1000 technology introduction and assimilation, CAP1400 is an advanced large passive nuclear power plant with independent intellectual property rights. By discussing the top design principle, main performance objectives, general parameters, safety design, and important improvements in safety, economy, an...

  2. Exact Lagrangian caps and non-uniruled Lagrangian submanifolds

    Science.gov (United States)

    Dimitroglou Rizell, Georgios

    2015-04-01

    We make the elementary observation that the Lagrangian submanifolds of C n , n≥3, constructed by Ekholm, Eliashberg, Murphy and Smith are non-uniruled and, moreover, have infinite relative Gromov width. The construction of these submanifolds involve exact Lagrangian caps, which obviously are non-uniruled in themselves. This property is also used to show that if a Legendrian submanifold inside a contactisation admits an exact Lagrangian cap, then its Chekanov-Eliashberg algebra is acyclic.

  3. Density functional study of condensation in capped capillaries

    Science.gov (United States)

    Yatsyshin, P.; Savva, N.; Kalliadasis, S.

    2015-07-01

    We study liquid adsorption in narrow rectangular capped capillaries formed by capping two parallel planar walls (a slit pore) with a third wall orthogonal to the two planar walls. The most important transition in confined fluids is arguably condensation, where the pore becomes filled with the liquid phase which is metastable in the bulk. Depending on the temperature T, the condensation in capped capillaries can be first-order (at T≤slant {{T}\\text{cw}} ) or continuous (at T\\gt {{T}\\text{cw}} ), where {{T}\\text{cw}} is the capillary wetting temperature. At T \\gt {{T}\\text{cw}} , the capping wall can adsorb mesoscopic amounts of metastable under-condensed liquid. The onset of condensation is then manifested by the continuous unbinding of the interface between the liquid adsorbed on the capping wall and the gas filling the rest of the capillary volume. In wide capped capillaries there may be a remnant of wedge filling transition, which is manifested by the adsorption of liquid drops in the corners. Our classical statistical mechanical treatment predicts a possibility of three-phase coexistence between gas, corner drops and liquid slabs adsorbed on the capping wall. In sufficiently wide capillaries we find that thick prewetting films of finite length may be nucleated at the capping wall below the boundary of the prewetting transition. Prewetting then proceeds in a continuous manner manifested by the unbinding interface between the thick and thin films adsorbed on the side walls. Our analysis is based on a detailed numerical investigation of the density functional theory for the fluid equilibria for a number of illustrative case studies.

  4. A decision tool for selecting trench cap designs

    Energy Technology Data Exchange (ETDEWEB)

    Paige, G.B.; Stone, J.J.; Lane, L.J. [USDA-ARS, Tucson, AZ (United States)] [and others

    1995-12-31

    A computer based prototype decision support system (PDSS) is being developed to assist the risk manager in selecting an appropriate trench cap design for waste disposal sites. The selection of the {open_quote}best{close_quote} design among feasible alternatives requires consideration of multiple and often conflicting objectives. The methodology used in the selection process consists of: selecting and parameterizing decision variables using data, simulation models, or expert opinion; selecting feasible trench cap design alternatives; ordering the decision variables and ranking the design alternatives. The decision model is based on multi-objective decision theory and uses a unique approach to order the decision variables and rank the design alternatives. Trench cap designs are evaluated based on federal regulations, hydrologic performance, cover stability and cost. Four trench cap designs, which were monitored for a four year period at Hill Air Force Base in Utah, are used to demonstrate the application of the PDSS and evaluate the results of the decision model. The results of the PDSS, using both data and simulations, illustrate the relative advantages of each of the cap designs and which cap is the {open_quotes}best{close_quotes} alternative for a given set of criteria and a particular importance order of those decision criteria.

  5. Interfacial and Wall Transport Models for SPACE-CAP Code

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Soon Joon; Choo, Yeon Joon; Han, Tae Young; Hwang, Su Hyun; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Choi, Hoon; Ha, Sang Jun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. And CAP (Containment Analysis Package) code has been also developed for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (gas, continuous liquid, and dispersed drop) for the assessment of containment specific phenomena, and is featured by its multidimensional assessment capabilities. Thermal hydraulics solver was already developed and now under testing of its stability and soundness. As a next step, interfacial and wall transport models was setup. In order to develop the best model and correlation package for the CAP code, various models currently used in major containment analysis codes, which are GOTHIC, CONTAIN2.0, and CONTEMPT-LT, have been reviewed. The origins of the selected models used in these codes have also been examined to find out if the models have not conflict with a proprietary right. In addition, a literature survey of the recent studies has been performed in order to incorporate the better models for the CAP code. The models and correlations of SPACE were also reviewed. CAP models and correlations are composed of interfacial heat/mass, and momentum transport models, and wall heat/mass, and momentum transport models. This paper discusses on those transport models in the CAP code.

  6. Signatures of Late Neoproterozoic Gondwana assembly and Maronian glaciation in Lesser Himalaya: a palaeogeographical and stratigraphical approach

    Science.gov (United States)

    Umar, Muhammad; Betts, Peter; Saud Khan, Malik Muhammad; Amjad Sabir, Muhammad; Farooq, Muhammad; Zeb, Asif; Khan Jadoon, Umair; Ali, Shoaib

    2015-03-01

    Stratigraphical and sedimentological analyses of Late Neoproterozoic successions in Lesser Himalaya are combined herein with palaeogeographical considerations and comparisons with equivalent successions in India and South China. The succession starts with the Hazara Formation, which contains complete and incomplete Bouma sequences suggesting its deposition in deep marine turbidite settings. The overlying Tanawal Formation, rich in massive sandstone, shale and siltstone, was deposited in shallow marine conditions, as indicated by the presence of parallel lamination, large scale tabular, trough cross- and hummocky cross-stratifications. The Tanawal Formation facies shift laterally from proximal (south-southeast) to distal (north-northwest). The glaciogenic Tanaki Boulder Bed, overlying the Tanawal Formation, was deposited during the Maronian glaciation. It is equivalent to the Blaini Formation of India, and to the Sinian diamictites of South China. The Abbottabad Formation of Cambrian age overlies the Tanaki Boulder Bed, and is composed of dolomite, chert nodules and phosphate-rich packages; similar successions are documented in India and South China at the same stratigraphical interval. The similarities of the Neoproterozoic successions of Lesser Himalaya (both in Pakistan and India) and South China suggests their possible proximity during the break-up of Rodinia and the assembly of the Gondwana Supercontinent.

  7. Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project

    Science.gov (United States)

    Fritz, Sherilyn C.; Baker, Paul A.; Seltzer, Geoffrey O.; Ballantyne, Ashley; Tapia, Pedro; Cheng, Hai; Edwards, R. Lawrence

    2007-11-01

    A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.

  8. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary

    Science.gov (United States)

    Amarilla, Leonardo D.; Anton, Ana M.; Chiapella, Jorge O.; Manifesto, María M.; Angulo, Diego F.; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species’ range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2–1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity. PMID:26110533

  9. Mass balance and sliding velocity of the Puget lobe of the cordilleran ice sheet during the last glaciation

    Science.gov (United States)

    Booth, D.B.

    1986-01-01

    An estimate of the sliding velocity and basal meltwater discharge of the Puget lobe of the Cordilleran ice sheet can be calculated from its reconstructed extent, altitude, and mass balance. Lobe dimensions and surface altitudes are inferred from ice limits and flow-direction indicators. Net annual mass balance and total ablation are calculated from relations empirically derived from modern maritime glaciers. An equilibrium-line altitude between 1200 and 1250 m is calculated for the maximum glacial advance (ca. 15,000 yr B.P.) during the Vashon Stade of the Fraser Glaciation. This estimate is in accord with geologic data and is insensitive to plausible variability in the parameters used in the reconstruction. Resultant sliding velocities are as much as 650 m/a at the equilibrium line, decreasing both up- and downglacier. Such velocities for an ice sheet of this size are consistent with nonsurging behavior. Average meltwater discharge increases monotonically downglacier to 3000 m3/sec at the terminus and is of a comparable magnitude to ice discharge over much of the glacier's ablation area. Palcoclimatic inferences derived from this reconstruction are consistent with previous, independently derived studies of late Pleistocene temperature and precipitation in the Pacific Northwest. ?? 1986.

  10. Lithologic influences on groundwater recharge through incised glacial till from profile to regional scales: Evidence from glaciated Eastern Nebraska

    Science.gov (United States)

    Gates, John B.; Steele, Gregory V.; Nasta, Paolo; Szilagyi, Jozsef

    2014-01-01

    Variability in sediment hydraulic properties associated with landscape depositional and erosional features can influence groundwater recharge processes by affecting soil-water storage and transmission. This study considers recharge to aquifers underlying river-incised glaciated terrain where the distribution of clay-rich till is largely intact in upland locations but has been removed by alluvial erosion in stream valleys. In a stream-dissected glacial region in eastern Nebraska (Great Plains region of the United States), recharge estimates were developed for nested profile, aquifer, and regional scales using unsaturated zone profile measurements (matric potentials, Cl- and 3H), groundwater tracers (CFC-12 and SF6), and a remote sensing-assisted water balance model. Results show a consistent influence of till lithology on recharge rates across nested spatial scales despite substantial uncertainty in all recharge estimation methods, suggesting that minimal diffuse recharge occurs through upland glacial till lithology whereas diffuse recharge occurs in river valleys where till is locally absent. Diffuse recharge is estimated to account for a maximum of 61% of total recharge based on comparison of diffuse recharge estimated from the unsaturated zone (0-43 mm yr-1) and total recharge estimated from groundwater tracers (median 58 mm yr-1) and water balance modeling (median 56 mm yr-1). The results underscore the importance of lithologic controls on the distributions of both recharge rates and mechanisms.

  11. Prices regulation in price-cap: the lessons of the british gas industry; Reglementations tarifaires en price-cap: les lecons de l'industrie gaziere anglaise

    Energy Technology Data Exchange (ETDEWEB)

    David, L.

    2003-07-01

    This article examines the problem of the price-cap regulation applied to the british gas transport. The RPI-X cap is a particular form of the price cap. This cap seems to be more remunerative for the regulatory firm than a cap calculated on the Laspeyres index because it authorizes a greater freedom of prices choice, to the prejudice of the consumers. Facing these perverse effects, Cowan proposed in 1997 a new system, not more satisfying. Another equation is analyzed in this article, proposed by Ofgem. Meanwhile this system presents no improvement of the consumers surplus facing the RPI-X cap. (A.L.B.)

  12. Lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, investigated using optically stimulated luminescence dating of beach ridges

    International Nuclear Information System (INIS)

    Li Dewen; Li Yingkui; Ma Baoqi; Zhao, Junxiang; Dong Guocheng; Wang Liqiang

    2009-01-01

    This paper presents a preliminary study on lake-level fluctuations since the Last Glaciation in Selin Co (lake), Central Tibet, by dating four groups of beach ridges using optically stimulated luminescence (OSL). The highest/oldest beach ridge group (>100 m higher than the current lake level) is dated back to 67.9 ± 2.4 ka BP, corresponding to the early stage of the Last Glaciation (marine isotope stage (MIS) 4). This date further supports that no plateau-scale ice sheet covered the Tibetan Plateau during the Last Glaciation. The other three groups produce OSL ages of 30.4 ± 2.9 to 18.6 ± 1.7, 12.5 ± 1.6 to 9.2 ± 0.5, and 6.9 ± 0.2 ka BP respectively, most likely corresponding to cold or wet climate periods of the late stage of the Last Glaciation (MIS 2), deglaciation, and Holocene Hypsithermal. On the plateau scale, these four beach ridge groups are almost synchronous with advances or standstills of Himalayan glaciers, indicating similar climate controls across the central and southern Tibetan Plateau, and being consistent with the conclusion, obtained from nearby ice core records, that this area is affected by the South Asia monsoon. Furthermore, beach ridges are also synchronous with fluvial terraces in the northern Tibetan Plateau, implying common driving forces during their formation. Therefore, some terraces may be formed as a result of climate events rather than being of tectonic origin.

  13. Concept of geomorphological analysis of previously glaciated areas (based on analysis of the surroundings of Prášilské jezero lake and jezero Laka lake, Šumava Mts., Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Mentlík, P.; Lisá, Lenka; Minár, J.

    2007-01-01

    Roč. 11, č. 5 (2007), s. 58-59 ISSN 1429-799X Institutional research plan: CEZ:AV0Z30130516 Keywords : glaciation * lake sediments * quartz micromorphology * geomorphology * mountains glaciers Subject RIV: DB - Geology ; Mineralogy

  14. The stratigraphic imprint of a mid-Telychian (Llandovery, Early Silurian glaciation on far-field shallow-water carbonates, Anticosti Island, Eastern Canada

    Directory of Open Access Journals (Sweden)

    François Clayer

    2014-12-01

    Full Text Available The near-field stratigraphic record of the Early Silurian glaciations is well documented in the literature. Data from far-field areas are, however, sparse. One of the best far-field stratigraphic records of these Llandovery glaciations is exposed on Anticosti Island in eastern Canada. Eight shallow-water paleotropical facies are present close to the mid-Telychian Jupiter–Chicotte formational boundary along the south-central coast of Anticosti Island. These can be grouped into three facies associations that include, from bottom to top: a carbonate facies association (FA-1, a mixed siliciclastic and carbonate facies association (FA-2 and an encrinitic facies association (FA-3. These mid- to outer-ramp strata represent deposition mostly from episodic, high-energy storm events as evidenced by their sharp bases, hummocky cross-stratification, large wave ripples, gutter casts and wave-enhanced sediment gravity flow deposits. Superimposed on a long-term regressive trend, one main transgressive–regressive (TR sequence and four meter-scale TR cycles are evident, indicating a multi-order stratigraphic framework developed under the influence of glacio-eustasy. The Jupiter–Chicotte formational boundary, a regional discontinuity surface caused by a forced regression, corresponds to the onset of a far-field mid-Telychian glaciation.

  15. Numerical modeling of the Snowmass Creek paleoglacier, Colorado, and climate in the Rocky Mountains during the Bull Lake glaciation (MIS 6)

    Science.gov (United States)

    Leonard, Eric M.; Plummer, Mitchell A.; Carrara, Paul E.

    2014-11-01

    Well-preserved moraines from the penultimate, or Bull Lake, glaciation of Snowmass Creek Valley in the Elk Range of Colorado (USA) present an opportunity to examine the character of the high-altitude climate in the Rocky Mountains during Marine Oxygen Isotope Stage 6. This study employs a 2-D coupled mass/energy balance and flow model to assess the magnitudes of temperature and precipitation change that could have sustained the glacier in mass-balance equilibrium at its maximum extent during the Bull Lake glaciation. Variable substrate effects on glacier flow and ice thickness make the modeling somewhat more complex than in geologically simpler settings. Model results indicate that a temperature depression of about 6.7°C compared with the present (1971-2000 AD) would have been necessary to sustain the Snowmass Creek glacier in mass-balance equilibrium during the Bull Lake glaciation, assuming no change in precipitation amount or seasonality. A 50% increase or decrease from modern precipitation would have been coupled with 5.2°C and 9.1°C Bull Lake temperature depressions respectively. Uncertainty in these modeled temperature depressions is about 1°C.

  16. Landscape Evolution and the Reincarnation of the Southern Residual Ice Cap

    Science.gov (United States)

    Byrne, S.; Zuber, M. T.

    2006-10-01

    Given the present rate of erosion on the southern residual ice cap, it is unlikely that any part of the cap is older than a few centuries. Unless we're lucky, why is there a residual cap present today for us to observe? We propose a solution involving constant destruction and renewal of the cap.

  17. PERANAN PAGUYUBAN TIONGHOA PURBALINGGA DALAM PELESTARIAN TRADISI CAP GO MEHPERANAN PAGUYUBAN TIONGHOA PURBALINGGA DALAM PELESTARIAN TRADISI CAP GO MEH

    Directory of Open Access Journals (Sweden)

    Rina Fitriyani

    2013-04-01

    Full Text Available Tujuan penelitian ini adalah menggambarkan peran Paguyuban Tionghoa Purbalingga (PTP dalam menjaga kebudayaan Tionghoa, khususnya tradisi Cap Go Meh. Sebelum  Paguyuban Tionghoa Purbalingga terbentuk, perayaan Cap Go Meh hanya dirayakan dalam lingkup keluarga dan di dalam rumah saja, akan tetapi setelah adanya Paguyuban Tionghoa Purbalingga tradisi ini dirayakan secara terbuka sehingga tidak hanya golongan Tionghoa yang merasakan akan tetapi juga masyarakat Purbalingga. Penelitian ini menggunakan pendekatan kualitatif dengan lokasi penelitian di kabupaten Purbalingga. Menggunakan bentuk analisis interaktif, penelitian ini menghasilkan fakta-fakta sebagai berikut. Bentuk-bentuk pelestarian tradisi Cap Go Meh meliputi perlindungan, pengembangan, dan pemanfaatan tradisi Cap Go Meh. Makna tradisi Cap Go Meh bagi masyarakat Tionghoa Purbalingga adalah wujud syukur, dan sarana berkumpul. Tradisi ini mengandung nilai 8 Jalan Kebenaran bagi golongan Tionghoa sesuai ajaran Tridharma Tionghoa yaitu kesetiaan (loyality, integritas (integrity, kesopanan (propriety, kebenaran moral (righteousness, kehormatan (honour, bakti (filial piety, kebajikan (kindness, kasih sayang (love.The objective of this study is to describe the role of Chinese Society of Purbalingga (PTP in conserving Chinese culture, especially the tradition of Cap Go Meh. Before the establishment of the Chinese Society of Purbalingga, Cap Go Meh was celebrated only in the sphere of family and home, but after the Chinese Society of Purbalingga was established, the tradition was celebrated openly so that not only the Chinese but also people of Purbalingga can feel its presence. The study method used is qualitative approach and the research sites is in the district Purbalingga. Using the form of interactive analysis, this research found the following facts. Preservation of Cap Go Meh tradition include these practices: protection, development, and utilization of Cap Go Meh tradition. The meaning

  18. Parametric study of propeller boss cap fins for container ships

    Directory of Open Access Journals (Sweden)

    Sang-Seop Lim

    2014-06-01

    Full Text Available The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD analysis with a propeller open water (POW test was performed to check the validity of CFD analysis. The design of experiment (DOE case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test

  19. Parametric study of propeller boss cap fins for container ships

    Science.gov (United States)

    Lim, Sang-Seop; Kim, Tae-Won; Lee, Dong-Myung; Kang, Chung-Gil; Kim, Soo-Young

    2014-06-01

    The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed

  20. Peptide-capped nanoparticles for catalysis and assembly

    Science.gov (United States)

    Briggs, Beverly D.

    Nature possesses methods for the formation and manipulation of inorganic materials with controlled size, shape, and compositions. Biomolecules, such as peptides, are known to be responsible for the generation of such inorganic materials on the nanoscale, where the enhanced properties can be exploited for various applications. Pd nanoparticles, capped with the Pd-specific Pd4 peptide (TSNAVHPTLRHL), were found to be active catalysts for Stille coupling, where the debated mechanism of oxidative addition was explored. Furthermore, the same Pd4-capped nanoparticles were found to be active in Suzuki coupling, another C-C coupling reaction that undergoes catalysis following a similar mechanism. Other considerations with peptide-capped metal catalysis involved the role of the reductant and the subsequent effects on morphology and reactivity, as seen by use of Au nanoparticles capped with a library of peptides. The role of the reductant was studied using varied reductants and was found to directly affect the catalytic activity. Additionally, such Au and Ag materials-binding peptides were expanded to generate multi-domain biomolecules capable of metal-specific binding and nanoparticle assembly. Such in-depth studies of peptide-capped nanomaterials and their uses in catalysis and assembly is important for optimized functionality and application.

  1. Submarine geomorphology of the Celtic Sea - new observations and hypotheses for the glaciation of a mid-latitude continental shelf

    Science.gov (United States)

    Praeg, Daniel; McCarron, Stephen; Dove, Dayton; Cofaigh, Colm Ó.; Monteys, Xavier; Coxon, Peter; Accettella, Daniella; Cova, Andrea; Facchin, Lorenzo; Romeo, Roberto; Scott, Gill

    2015-04-01

    The southern limit of glaciation of the European continental margin lies in the Celtic Sea, where the full extent and dynamics of the British-Irish Ice Sheet (BIIS) remain in question. This is in part because the broad continental shelf contains no obvious glacial geomorphological features, but is dominated by a system of shelf-crossing sediment ridges, up to 60 m high, 10 km wide and 300 km long, traditionally interpreted as moribund palaeo-tidal sand banks. Ice sheet extent has been constrained by samples of subglacial and glacimarine sediments recovered (in the 1970s) between the ridges, and in places on their flanks, used to propose a tidewater ice margin that advanced to a grounding line on the mid-shelf, overriding a precursor ridge system. New information on the glaciation of the Celtic Sea is available from geophysical and core data acquired during Italian- and Irish-led campaigns in 2009, 2012, and 2014, both from the mid- and outer shelf. On the mid-shelf, multibeam seabed imagery of a 25 x 100 km area reveal a distinctive rectilinear network of en echelon ridge segments giving way laterally and longitudinally to transverse ribs. Seismic correlation to glacigenic sediments previously cored on a ridge flank (at core site 49/-09/44) indicates the ribs to be composed in part of glacimarine sediments, above a till reflection that can be traced across the ridge crest. No change in seabed morphology is observed across the proposed grounding line. On the outer shelf, new cores of glacigenic sediments were obtained from the flank of a shelf-crossing ridge, and provide evidence of ice sheet advance to the shelf edge, 150 km beyond the proposed grounding line. The cores from outer Cockburn Bank contain facies interpreted to record subglacial deformation and glacimarine deposition from turbid meltwater plumes during withdrawal of a tidewater ice sheet margin from the shelf edge by 24,265 ± 195 cal BP. These sediments are inferred to form part of a sheet of

  2. Timing of Pleistocene glaciations in the High Atlas, Morocco: New 10Be and 36Cl exposure ages

    Science.gov (United States)

    Hughes, Philip D.; Fink, David; Rodés, Ángel; Fenton, Cassandra R.; Fujioka, Toshiyuki

    2018-01-01

    This paper presents data from 42 new samples yielding Late Pleistocene cosmogenic 10Be and 36Cl exposure ages of moraine boulders across a series of glaciated valleys in the Toubkal Massif (4167 m a.s.l.), High Atlas, Morocco. This represents the first comprehensive Pleistocene glacial chronology in North Africa and one of the largest datasets from the Mediterranean region. The timing of these glacier advances has major implications for understanding the influence of Atlantic depressions on moisture supply to North Africa and the Mediterranean basin during the Pleistocene. The oldest and lowest moraines which span elevations from ∼1900 to 2400 m a.s.l. indicate that the maximum glacier advance occurred from MIS 5 to 3 with a combined mean 10Be and 36Cl age of 50.2 ± 19.5 ka (1 SD; n = 12, 7 outliers). The next moraine units up-valley at higher elevations (∼2200-2600 m a.s.l.) yielded exposure ages close to the global Last Glacial Maximum (LGM) with a combined mean 10Be and 36Cl age of 22.0 ± 4.9 ka (1 SD; n = 9, 7 outliers). The youngest exposure ages are from moraines that were emplaced during the Younger Dryas with a combined mean 10Be and 36Cl age of 12.3 ± 0.9 ka (1 SD; n = 7, no outliers) and are found in cirques at the highest elevations ranging from ∼2900 to 3300 m a.s.l. From moraines predating the Younger Dryas, a large number of young outliers are spread evenly between 6 and 13 ka suggesting a continuing process of exhumation or repositioning of boulders during the early to mid-Holocene. This attests to active seismic processes and possibly intense erosion during this period.

  3. Tectonomorphic evolution of Marie Byrd Land - Implications for Cenozoic rifting activity and onset of West Antarctic glaciation

    Science.gov (United States)

    Spiegel, Cornelia; Lindow, Julia; Kamp, Peter J. J.; Meisel, Ove; Mukasa, Samuel; Lisker, Frank; Kuhn, Gerhard; Gohl, Karsten

    2016-10-01

    glaciation of this part of West Antarctica may have only started since the early Miocene.

  4. Texture and geochemistry of surface horizons of Arctic soils from a non-glaciated catchment, SW Spitsbergen

    Directory of Open Access Journals (Sweden)

    Szymański Wojciech

    2016-09-01

    Full Text Available Physical and chemical properties of Arctic soils and especially the properties of surface horizons of the soils are very important because they are responsible for the rate and character of plant colonization, development of vegetation cover, and influence the rate and depth of thawing of soils and development of active layer of permafrost during summer. The main aim of the present study is to determine and explain the spatial diversity of selected physical and chemical properties of surface horizons of Arctic soils from the non-glaciated Fuglebekken catchment located in the Hornsund area (SW Spitsbergen by means of geostatistical approach. Results indicate that soil surface horizons in the Fuglebekken catchment are characterized by highly variable physical and chemical properties due to a heterogeneous parent material (marine sediments, moraine, rock debris, tundra vegetation types, and non-uniform influence of seabirds. Soils experiencing the strongest influence of seabird guano have a lower pH than other soils. Soils developed on the lateral moraine of the Hansbreen glacier have the highest pH due to the presence of carbonates in the parent material and a lack or presence of a poorly developed and discontinuous A horizon. The soil surface horizons along the coast of the Hornsund exhibit the highest content of the sand fraction and SiO2. The surface of soils occurring at the foot of the slope of Ariekammen Ridge is characterized by the highest content of silt and clay fractions as well as Al2O3, Fe2O3, and K2O. Soils in the central part of the Fuglebekken catchment are depleted in CaO, MgO, and Na2O in comparison with soils in the other sampling sites, which indicates the highest rate of leaching in this part of the catchment.

  5. Caps Seal Boltholes On Vacuum-System Flanges

    Science.gov (United States)

    Roman, Robert F.

    1993-01-01

    Sealing caps devised for boltholes on vacuum-system flanges. Used in place of leak-prone gaskets, and provide solid metal-to-metal interfaces. Each sealing cap contains square-cut circular groove in which O-ring placed. Mounted on studs protruding into access ports, providing positive seal around each bolthole. Each cap mates directly with surface of flange, in solid metal-to-metal fit, with O-ring completely captured in groove. Assembly immune to misalignment, leakage caused by vibration, and creeping distortion caused by weight of port. O-ring material chosen for resistance to high temperature; with appropriate choice of material, temperature raised to as much as 315 degrees C.

  6. Cyclic alternating pattern (CAP): the marker of sleep instability.

    Science.gov (United States)

    Parrino, Liborio; Ferri, Raffaele; Bruni, Oliviero; Terzano, Mario G

    2012-02-01

    Cyclic alternating pattern CAP is the EEG marker of unstable sleep, a concept which is poorly appreciated among the metrics of sleep physiology. Besides, duration, depth and continuity, sleep restorative properties depend on the capacity of the brain to create periods of sustained stable sleep. This issue is not confined only to the EEG activities but reverberates upon the ongoing autonomic activity and behavioral functions, which are mutually entrained in a synchronized oscillation. CAP can be identified both in adult and children sleep and therefore represents a sensitive tool for the investigation of sleep disorders across the lifespan. The present review illustrates the story of CAP in the last 25 years, the standardized scoring criteria, the basic physiological properties and how the dimension of sleep instability has provided new insight into pathophysiolology and management of sleep disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Economic evaluation of closure cap barrier materials study

    Energy Technology Data Exchange (ETDEWEB)

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration.

  8. Assessing the value of price caps and floors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This publication assesses the long-term economic and climatic effects of introducing price caps and price floors in hypothetical global climate change mitigation policy. Based on emission trends, abatement costs and equilibrium climate sensitivity from IPCC and IEA reports, this quantitative analysis confirms that price caps could significantly reduce economic uncertainty. This uncertainty stems primarily from unpredictable economic growth and energy prices, and ultimately unabated emission trends. In addition, the development of abatement technologies is uncertain. Furthermore,this analysis shows that rigid targets may entail greater economic risks with little or no comparative advantage for the climate. More ambitious emission objectives, combined with price caps and price floors, could still entail significantly lower expected costs while driving similar, or even slightly better, climatic outcomes in probabilistic terms.

  9. Controlling the Shapes of Silver Nanocrystals with Different Capping Agents

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, J.; Tao, J.; Zheng, Y.; Rycenga, M.; Li, Z.-Y.; Zhang, Q.A.; Zhu, Y.; Xia, Y.

    2010-06-30

    This paper provides direct evidence to support the role of a capping agent in controlling the evolution of Ag seeds into nanocrystals with different shapes. Starting with single-crystal seeds (spherical or cubic in shape), we could selectively obtain Ag octahedrons enclosed by {l_brace}111{r_brace} facets and nanocubes/nanobars enclosed by {l_brace}100{r_brace} facets by adding sodium citrate (Na{sub 3}CA) and poly(vinyl pyrrolidone) (PVP), respectively, as a capping agent while all other parameters were kept the same. This research not only offers new insights into the role played by a capping agent in shape-controlled synthesis but also provides, for the first time, Ag octahedrons as small as 40 nm in edge length for optical and spectroscopic studies.

  10. Controlling the shapes of silver nanocrystals with different capping agents.

    Science.gov (United States)

    Zeng, Jie; Zheng, Yiqun; Rycenga, Matthew; Tao, Jing; Li, Zhi-Yuan; Zhang, Qiang; Zhu, Yimei; Xia, Younan

    2010-06-30

    This paper provides direct evidence to support the role of a capping agent in controlling the evolution of Ag seeds into nanocrystals with different shapes. Starting with single-crystal seeds (spherical or cubic in shape), we could selectively obtain Ag octahedrons enclosed by {111} facets and nanocubes/nanobars enclosed by {100} facets by adding sodium citrate (Na(3)CA) and poly(vinyl pyrrolidone) (PVP), respectively, as a capping agent while all other parameters were kept the same. This research not only offers new insights into the role played by a capping agent in shape-controlled synthesis but also provides, for the first time, Ag octahedrons as small as 40 nm in edge length for optical and spectroscopic studies.

  11. CAPS and Munc13: CATCHRs that SNARE vesicles

    Directory of Open Access Journals (Sweden)

    Declan J James

    2013-12-01

    Full Text Available Abstract. CAPS (Calcium-dependent Activator Protein for Secretion, aka CADPS and Munc13 (Mammalian Unc-13 proteins function to prime vesicles for Ca2+-triggered exocytosis in neurons and neuroendocrine cells. CAPS and Munc13 proteins contain conserved C-terminal domains that promote the assembly of SNARE complexes for vesicle priming. Similarities of the C-terminal domains of CAPS/Munc13 proteins with CATCHR (Complex Associated with Tethering Containing Helical Rods domains in multi-subunit tethering complexes have been reported. Multi-subunit tethering complexes coordinate multiple interactions for SNARE complex assembly at constitutive membrane fusion steps. We review aspects of these diverse tethering and priming factors to identify common operating principles.

  12. Buy badges and help finance Cap Loisirs activities!

    CERN Document Server

    2008-01-01

    Please give a warm welcome to Cap Loisirs’ volunteers who will be manning a stand at the main entrance on Friday 8 February! In honour of St. Valentine’s Day, they will be selling a selection of 5 badges designed by artist Anna Sommer, depicting declarations of love by our friends from the animal kingdom. Price : Frs. 3.- per badge The aim of Fondation Cap Loisirs is to provide leisure activities for mentally handicapped children, adolescents and adults. The Foundation offers a wide range of activities which allow the mentally handicapped to enjoy quality leisure in areas as varied as culture, sport, tourism, travel and artistic expression. Fondation Cap Loisirs Rue de Monthoux 66 – 1201 Geneva – Tel: 022 731 86 00 – CCP Genève 12-5587-5 – caploisirs@caploisirs.ch – http://www.Caploisirs.ch

  13. Economic evaluation of closure cap barrier materials study

    International Nuclear Information System (INIS)

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration

  14. Empiric penicillin monotherapy of CAP is not associated with increased mortality; experiences from the retrospective CAP-North cohort

    DEFF Research Database (Denmark)

    Baunbæk-Knudsen, Getrud; Vestergaard Jensen, Andreas; Andersen, Stine

    2016-01-01

    Background: Community-acquired pneumonia (CAP) is a severe infection, with high morbidity and mortality. The antibiotic strategies for CAP differ across Europe. Objective: To assess the usage of Penicillin monotherapy in a real-life cohort and to evaluate predictors of treatment duration and the ......Background: Community-acquired pneumonia (CAP) is a severe infection, with high morbidity and mortality. The antibiotic strategies for CAP differ across Europe. Objective: To assess the usage of Penicillin monotherapy in a real-life cohort and to evaluate predictors of treatment duration......, and evaluated predictors of treatment duration by linear regression. Mortality of patients receiving empiric penicillin-G/V was compared to others by logistic regression analysis. The CAPNETZ database technology was used for data-capture. Results: We included 1320 patients. The incidence of hospitalized CAP...... was 3.1 per 1000 inhabitants. The median age was 71 years (IQR; 58.81). In-hospital mortality was 8%. Patients treated with penicillin-G/V as empiric monotherapy (45%) did not have a higher mortality than those treated with broader spectrum antibiotics (OR 1.30, CI 95% 0.84-2-02). The median duration...

  15. CapsID: a web-based tool for developing parsimonious sets of CAPS molecular markers for genotyping

    Directory of Open Access Journals (Sweden)

    Provart Nicholas J

    2006-05-01

    Full Text Available Abstract Background Genotyping may be carried out by a number of different methods including direct sequencing and polymorphism analysis. For a number of reasons, PCR-based polymorphism analysis may be desirable, owing to the fact that only small amounts of genetic material are required, and that the costs are low. One popular and cheap method for detecting polymorphisms is by using cleaved amplified polymorphic sequence, or CAPS, molecular markers. These are also known as PCR-RFLP markers. Results We have developed a program, called CapsID, that identifies snip-SNPs (single nucleotide polymorphisms that alter restriction endonuclease cut sites within a set or sets of reference sequences, designs PCR primers around these, and then suggests the most parsimonious combination of markers for genotyping any individual who is not a member of the reference set. The output page includes biologist-friendly features, such as images of virtual gels to assist in genotyping efforts. CapsID is freely available at http://bbc.botany.utoronto.ca/capsid. Conclusion CapsID is a tool that can rapidly provide minimal sets of CAPS markers for molecular identification purposes for any biologist working in genetics, community genetics, plant and animal breeding, forensics and other fields.

  16. Cap polyposis: a rare cause of rectal bleeding in children.

    Science.gov (United States)

    Li, Jia Hui; Leong, May Ying; Phua, Kong Boo; Low, Yee; Kader, Ajmal; Logarajah, Veena; Ong, Lin Yin; Chua, Joyce Hy; Ong, Christina

    2013-07-14

    To evaluate the clinicopathological features and treatment outcomes of cap polyposis in the pediatric population. All pediatric patients with histologically proven diagnosis of cap polyposis were identified from our endoscopy and histology database over a 12 year period from 2000-2012 at our tertiary pediatric center, KK Women's and Children's Hospital in Singapore. The case records of these patients were retrospectively reviewed. The demographics, clinical course, laboratory results, endoscopic and histopathological features, treatments, and outcomes were analyzed. The study protocol was approved by the hospital institutional review board. The histological slides were reviewed by a pediatric histopathologist to confirm the diagnosis of cap polyposis. Eleven patients were diagnosed with cap polyposis. The median patient age was 13 years (range 5-17 years); the sample included 7 males and 4 females. All of the patients presented with bloody stools. Seven patients (63%) had constipation, while 4 patients (36%) had diarrhea. All of the patients underwent colonoscopy and polypectomies (excluding 1 patient who refused polypectomy). The macroscopic findings were of polypoid lesions covered by fibrinopurulent exudates with normal intervening mucosa. The rectum was the most common involvement site (n = 9, 82%), followed by the rectosigmoid colon (n = 3, 18%). Five (45%) patients had fewer than 5 polyps, and 6 patients (65%) had multiple polyps. Histological examination of these polyps showed surface ulcerations with a cap of fibrin inflammatory exudate. Four (80%) patients with fewer than 5 polyps had complete resolution of symptoms following the polypectomy. One patient who did not consent to the polypectomy had resolution of symptoms after being treated with sulphasalazine. All 6 patients with multiple polyps experienced recurrence of bloody stools on follow-up (mean = 28 mo). Cap polyposis is a rare and under-recognised cause of rectal bleeding in children. Our study

  17. Water Ice Albedo Variations on the Martian Northern Polar Cap

    Science.gov (United States)

    Hale, A. S.; Bass, D. S.; Tamppari, L. K.

    2003-01-01

    The Viking Orbiters determined that the surface of Mars northern residual cap is water ice. Many researchers have related observed atmospheric water vapor abundances to seasonal exchange between reservoirs such as the polar caps, but the extent to which the exchange between the surface and the atmosphere remains uncertain. Early studies of the ice coverage and albedo of the northern residual Martian polar cap using Mariner 9 and Viking images reported that there were substantial internannual differences in ice deposition on the polar cap, a result which suggested a highly variable Martian climate. However, some of the data used in these studies were obtained at differing values of heliocentric solar longitude (L(sub s)). Reevaluation of this dataset indicated that the residual cap undergoes seasonal brightening throughout the summer, and indicated that this process repeats from year to year. In this study we continue to compare Mariner 9 and Viking Orbiter imaging observations and thermal data of the north residual polar cap to data acquired with Mars Global Surveyor s Mars Orbiter Camera (MOC) instrument. In the current study, our goal is to examine all released data from MGS MOC in the northern summer season, along with applicable TES data in order to better understand the albedo variations in the northern summer and their implications on water transport. To date, work has focused primarily on the MOC dataset. In 1999, data acquisition of the northern polar regions began at L(sub s) = 107, although there was little north polar data acquired from L(sub s)= 107 to L(sub s) = 109. We examined a total of 409 images from L(sub s) = 107 to L(sub s)=148. We have also examined data from 2000 from L(sub s)= 93 to L(sub s)= 110; additional progress is ongoing. Here we present a progress report of our observations, and continue to determine their implications for the Martian water cycle.

  18. Elevation Changes of Ice Caps in the Canadian Arctic Archipelago

    Science.gov (United States)

    Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Yungel, J.; Koerner, R.

    2004-01-01

    Precise repeat airborne laser surveys were conducted over the major ice caps in the Canadian Arctic Archipelago in the spring of 1995 and 2000 in order to measure elevation changes in the region. Our measurements reveal thinning at lower elevations (below 1600 m) on most of the ice caps and glaciers, but either very little change or thickening at higher elevations in the ice cap accumulation zones. Recent increases in precipitation in the area can account for the slight thickening where it was observed, but not for the thinning at lower elevations. For the northern ice caps on the Queen Elizabeth Islands, thinning was generally less than 0.5 m/yr , which is consistent with what would be expected from the warm temperature anomalies in the region for the 5-year period between surveys and appears to be a continuation of a trend that began in the mid 1980s. Further south, however, on the Barnes and Penny ice caps on Baffin Island, this thinning was much more pronounced at over 1 m/yr in the lower elevations. Here temperature anomalies were very small, and the thinning at low elevations far exceeds any associated enhanced ablation. The observations on Barnes, and perhaps Penny are consistent with the idea that the observed thinning is part of a much longer term deglaciation, as has been previously suggested for Barnes Ice Cap. Based on the regional relationships between elevation and elevation-change in our data, the 1995-2000 mass balance for the region is estimated to be 25 cu km/yr of ice, which corresponds to a sea level increase of 0.064 mm/ yr . This places it among the more significant sources of eustatic sea level rise, though not as substantial as Greenland ice sheet, Alaskan glaciers, or the Patagonian ice fields.

  19. Enzymatic synthesis of RNAs capped with nucleotide analogues reveals the molecular basis for substrate selectivity of RNA capping enzyme: impacts on RNA metabolism.

    Directory of Open Access Journals (Sweden)

    Moheshwarnath Issur

    Full Text Available RNA cap binding proteins have evolved to specifically bind to the N7-methyl guanosine cap structure found at the 5' ends of eukaryotic mRNAs. The specificity of RNA capping enzymes towards GTP for the synthesis of this structure is therefore crucial for mRNA metabolism. The fact that ribavirin triphosphate was described as a substrate of a viral RNA capping enzyme, raised the possibility that RNAs capped with nucleotide analogues could be generated in cellulo. Owing to the fact that this prospect potentially has wide pharmacological implications, we decided to investigate whether the active site of the model Paramecium bursaria Chlorella virus-1 RNA capping enzyme was flexible enough to accommodate various purine analogues. Using this approach, we identified several key structural determinants at each step of the RNA capping reaction and generated RNAs harboring various different cap analogues. Moreover, we monitored the binding affinity of these novel capped RNAs to the eIF4E protein and evaluated their translational properties in cellulo. Overall, this study establishes a molecular rationale for the specific selection of GTP over other NTPs by RNA capping enzyme It also demonstrates that RNAs can be enzymatically capped with certain purine nucleotide analogs, and it also describes the impacts of modified RNA caps on specific steps involved in mRNA metabolism. For instance, our results indicate that the N7-methyl group of the classical N7-methyl guanosine cap is not always indispensable for binding to eIF4E and subsequently for translation when compensatory modifications are present on the capped residue. Overall, these findings have important implications for our understanding of the molecular determinants involved in both RNA capping and RNA metabolism.

  20. Response of Eyjafjallajökull, Torfajökull and Tindfjallajökull ice caps in Iceland to regional warming, deduced by remote sensing

    Directory of Open Access Journals (Sweden)

    Jørgen Dall

    2011-07-01

    Full Text Available We assess the volume change and mass balance of three ice caps in southern Iceland for two periods, 1979–1984 to 1998 and 1998 to 2004, by comparing digital elevation models (DEMs. The ice caps are Eyjafjallajökull (ca. 81 km2, Tindfjallajökull (ca. 15 km2 and Torfajökull (ca. 14 km2. The DEMs were compiled using aerial photographs from 1979 to 1984, airborne Synthetic Aperture Radar (SAR images obtained in 1998 and two image pairs from the SPOT 5 satellite's high-resolution stereoscopic (HRS instrument acquired in 2004. The ice-free part of the accurate DEM from 1998 was used as a reference map for co-registration and correction of the vertical offset of the other DEMs. The average specific mass balance was estimated from the mean elevation difference between glaciated areas of the DEMs. The glacier mass balance declined significantly between the two periods: from −0.2 to 0.2 m yr−1 w. eq. during the earlier period (1980s through 1998 to −1.8 to −1.5 m yr−1 w. eq. for the more recent period (1998–2004. The declining mass balance is consistent with increased temperature over the two periods. The low mass balance and the small accumulation area ratio of Tindfjallajökull and Torfajökull indicate that they will disappear if the present-day climate continues. The future lowering rate of Eyjafjallajökull will, however, be influenced by the 2010 subglacial eruption in the Eyjafjallajökull volcano.

  1. Glacial Boundary Features Delineated Using Enhanced-resolution Passive-microwave Data to Determine Melt Season Variation of the Vatnajokull Ice Cap, Iceland

    Science.gov (United States)

    Marzillier, D. M.; Ramage, J. M.

    2017-12-01

    Temperate glaciers such as those seen in Iceland experience high annual mass flux, thereby responding to small scale changes in Earth's climate. Decadal changes in the glacial margins of Iceland's ice caps are observable in the Landsat record, however twice daily AMSR-E Calibrated Enhanced-Resolution Passive Microwave Daily EASE-Grid 2.0 Brightness Temperature (CETB) Earth System Data Record (ESDR) allow for observation on a daily temporal scale and a 3.125 km spatial scale, which can in turn be connected to patterns seen over longer periods of time. Passive microwave data allow for careful observation of melt onset and duration in Iceland's glacial regions by recording changes in emissivity of the ice surface, known as brightness temperature (TB), which is sensitive to fluctuations in the liquid water content of snow and ice seen during melting in glaciated regions. Enhanced resolution of this data set allows for a determination of a threshold that defines the melting season. The XPGR snowmelt algorithm originally presented by Abdalati and Steffen (1995) is used as a comparison with the diurnal amplitude variation (DAV) values on Iceland's Vatnajokull ice cap located at 64.4N, -16.8W. Ground-based air temperature data in this region, digital elevation models (DEMs), and river discharge dominated by glacial runoff are used to confirm the glacial response to changes in global climate. Results show that Iceland glaciers have a bimodal distribution of brightness temperature delineating when the snow/ice is melting and refreezing. Ground based temperatures have increased on a decadal trend. Clear glacial boundaries are visible on the passive microwave delineating strong features, and we are working to understand their variability and contribution to glacier evolution. The passive microwave data set allows connections to be made between observations seen on a daily scale and the long term glacier changes observed by the Landsat satellite record that integrates the

  2. Three-dimensional analysis of two-pile caps

    Directory of Open Access Journals (Sweden)

    T.E.T. Buttignol

    Full Text Available This paper compares the results between a non-linear three-dimensional numerical analysis of pile caps with two piles and the experimental study conducted by Delalibera. It is verified the load-carrying capacity, the crack pattern distribution, the principal stress in concrete and steel, the deflection and the fracture of the pile cap. The numerical analysis is executed with the finite-element software ATENA 3D, considering a perfect bond between concrete and steel. The numerical and experimental results are presented and have demonstrated a good approximation, reasserting the results of the experimental model and corroborating the theory.

  3. A comparative study of internally and externally capped balloons using small scale test balloons

    Science.gov (United States)

    Bell, Douglas P.

    1994-01-01

    Caps have been used to structurally reinforce scientific research balloons since the late 1950's. The scientific research balloons used by the National Aeronautics and Space Administration (NASA) use internal caps. A NASA cap placement specification does not exist since no empirical information exisits concerning cap placement. To develop a cap placement specification, NASA has completed two in-hangar inflation tests comparing the structural contributions of internal caps and external caps. The tests used small scale test balloons designed to develop the highest possible stresses within the constraints of the hangar and balloon materials. An externally capped test balloon and an internally capped test balloon were designed, built, inflated and simulated to determine the structural contributions and benefits of each. The results of the tests and simulations are presented.

  4. Dynamic pattern of prices under price-cap regulation; Price cap kiseika no ryokin hendo pattern

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-07-01

    In this analysis, a power rate determination model was developed for numerical experiment, a dynamic pattern of prices under price-cap regulation (PCR) which has been overlooked in the analysis, and a study was made on if the Ramsey pricing can be realized. A power rate determination simulation model was developed which maximizes a total amount of profits from corporate acts under PCR. By expanding the model in future, policy simulations on PCR under various conditions became possible. With relation to the rate determination act under PCR, two cases were assumed for the simulational comparison: the case in which competition is introduced into the power sector, and the case in which both the power sector and lighting sector are monopolistic for comparison with the former case. As a result, it was confirmed that in any cases the rate of power demand which is relatively price-dynamic under PCR largely declined and contrarily the lighting rate soars. 12 refs., 5 figs., 13 tabs.

  5. Integrated Modeling and Decision-Support System for Water Management in the Puget Sound Basin: Snow Caps to White Caps

    Energy Technology Data Exchange (ETDEWEB)

    Copping, Andrea E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yang, Zhaoqing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Voisin, Nathalie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richey, Jeff [Univ. of Washington, Seattle, WA (United States); Wang, Taiping [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Taira, Randal Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Constans, Michael [Univ. of Washington, Seattle, WA (United States); Wigmosta, Mark S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Van Cleve, Frances B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tesfa, Teklu K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    Final Report for the EPA-sponsored project Snow Caps to White Caps that provides data products and insight for water resource managers to support their predictions and management actions to address future changes in water resources (fresh and marine) in the Puget Sound basin. This report details the efforts of a team of scientists and engineers from Pacific Northwest National Laboratory (PNNL) and the University of Washington (UW) to examine the movement of water in the Snohomish Basin, within the watershed and the estuary, under present and future conditions, using a set of linked numerical models.

  6. Climate Change Projections for the Tropical Andes Using Multiple Emission Scenarios: Implications for Future Glaciation and Water Resources

    Science.gov (United States)

    Vuille, M.; Urrutia, R.

    2008-12-01

    increased and decreased precipitation across the Andes. These results provide a first attempt at quantifying future climate change in the tropical Andes and could serve as input for impact models to simulate anticipated changes in Andean glaciation, hydrology and ecosystem integrity. In particular these simulations could help to analyze future changes in streamflow seasonality which might affect the water availability downstream due to the reduction of the glacial buffer during the dry season. They could also be used to assess for how long current glacier retreat and mass loss will add to a temporary increase in runoff, a process that raises sustainability concerns as downstream users quickly adapt to the temporary water surplus.

  7. Disentangling the record of diagenesis, local redox conditions, and global seawater chemistry during the latest Ordovician glaciation

    Science.gov (United States)

    Ahm, Anne-Sofie C.; Bjerrum, Christian J.; Hammarlund, Emma U.

    2017-02-01

    The Late Ordovician stratigraphic record integrates glacio-eustatic processes, water-column redox conditions and carbon cycle dynamics. This complex stratigraphic record, however, is dominated by deposits from epeiric seas that are susceptible to local physical and chemical processes decoupled from the open ocean. This study contributes a unique deep water basinal perspective to the Late Ordovician (Hirnantian) glacial record and the perturbations in seawater chemistry that may have contributed to the Hirnantian mass extinction event. We analyze recently drilled cores and outcrop samples from the upper Vinini Formation in central Nevada and report combined trace- and major element geochemistry, Fe speciation (FePy /FeHR and FeHR /FeT), and stable isotope chemostratigraphy (δ13COrg and δ34SPy). Measurements of paired samples from outcrop and core reveal that reactive Fe is preserved mainly as pyrite in core samples, while outcrop samples have been significantly altered as pyrite has been oxidized and remobilized by modern weathering processes. Fe speciation in the more pristine core samples indicates persistent deep water anoxia, at least locally through the Late Ordovician, in contrast to the prevailing interpretation of increased Hirnantian water column oxygenation in shallower environments. Deep water redox conditions were likely decoupled from shallower environments by a basinal shift in organic matter export driven by decreasing rates of organic matter degradation and decreasing shelf areas. The variable magnitude in the record of the Hirnantian carbon isotope excursion may be explained by this increased storage of isotopically light carbon in the deep ocean which, in combination with increased glacio-eustatic restriction, would strengthen lateral- and vertical gradients in seawater chemistry. We adopt multivariate statistical methods to deconstruct the spatial and temporal re-organization of seawater chemistry during the Hirnantian glaciation and attempt to

  8. Shelf life of pie caps with biodegradable films as spacers

    Directory of Open Access Journals (Sweden)

    Daniela Verónica Escobar Gianni

    2013-01-01

    Full Text Available Commonly pie caps at market use polyethylene films as spacers between them. This paper studies the conventional spacers replacement with edible and biodegradable films made with whey protein isolate (WPI and potassium sorbate as a preservative. Besides facilitating the separation of pie caps, with this application is intended to increase their shelf life. The films made by the compression molding method were used as spacers in pie caps without preservative in their formula (A and with preservative (B and they were compared with conventional polyethylene spacers (C. During four months, monthly sensory, microbiological and physicochemical (humidity evaluations were done on the pie caps, together with humidity and solubility evaluations of the films. None of the samples showed microbiological or sensory deterioration. The sensory attributes showed no or slight difference in study time. Between samples the differences were minor: the best scores were for sample A in color, sample C in flavor, and samples B and C in texture and overall liking. The edible films have an interesting potential for this application, although studies in disguise the flavor of serum should be done.

  9. 1 | Page ARBITRATION AND CONCILIATION ACT CAP A18 LAWS ...

    African Journals Online (AJOL)

    Fr. Ikenga

    The primary sources of the Nigerian Law of Arbitration are the English Common Law, the Nigerian. Customary ... NWAKOBY: Arbitration and Conciliation Act Cap A18 Laws of the Federation of Nigeria 2004 -Call for Amendment the arbitration .... parte application before a formal application by motion on notice. Some also ...

  10. Aspiration of a perforated pen cap: complete tracheal obstruction ...

    African Journals Online (AJOL)

    shape, their rigid material (plastic or metal), and smooth ... symptoms after choking on a plastic pen cap. A FBA was suspected. .... Its use was initially limited because of the lack of adequate working channels and satisfactory ancillary extraction instruments. In a recent study including 1027 flexible bronchoscopies in children ...

  11. Facially amphiphilic thiol capped gold and silver nanoparticles

    Indian Academy of Sciences (India)

    Wintec

    Jawaharlal Nehru Centre for Advanced Scientific Research,. Bangalore 560 064. Facially amphiphilic thiol capped gold and silver nanoparticles. †. SHREEDHAR BHAT a and UDAY MAITRA*. Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012 a. Current address: ISM, University of Bordeaux, ...

  12. Magnetic actuation and transition shapes of a bistable spherical cap

    Directory of Open Access Journals (Sweden)

    E.G. Loukaides

    2014-10-01

    Full Text Available Multistable shells have been proposed for a variety of applications; however, their actuation is almost exclusively addressed through embedded piezoelectric patches. Additional actuation techniques are needed for applications requiring high strains or where remote actuation is desirable. Part of the reason for the lack of research in this area is the absence of appropriate models describing the detailed deformation and energetics of such shells. This work presents a bistable spherical cap made of iron carbonyl-infused polydimethylsiloxane. The magnetizable structure can be actuated remotely through permanent magnets while the transition is recorded with a high-speed camera. Moreover, the experiment is reproduced in a finite element (FE dynamic model for comparison with the physical observations. High-speed footage of the physical cap inversion together with the FE modeling gives valuable insight on preferable intermediate geometries. Both methods return similar values for the magnetic field strength required for the snap-through. High-strain multistable spherical cap transformation is demonstrated, based on informed material selection. We discover that non-axisymmetric transition shapes are preferred in intermediate geometries by bistable spherical caps. We develop the methods for design and analysis of such actuators, including the feasibility of remote actuation methods for multistable shells.

  13. Effect of capping agents on optical and antibacterial properties of ...

    Indian Academy of Sciences (India)

    ... spectra of CdSe QDs confirmed that the particles are poly-dispersed and possess enhanced luminescent property, depending upon the chemical nature of capping agents. The QDs have been characterized by Fourier-transform infrared spectroscopy, atomic absorption spectroscopy and transmission electron microscopy.

  14. CAPS OpenACC Compilers: Performance and Portability

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    The announcement late 2011 of the new OpenACC directive-based programming standard supported by CAPS, CRAY and PGI compilers has open up the door to more scientific applications that can be ported on many-core systems. Following a porting methodology, this talk will first review the principles of programming with OpenACC and then the advanced features available in the CAPS compilers to further optimize OpenACC applications: library integration, tuning directives with auto-tune mechanisms to build applications adaptive to different GPUs. CAPS compilers use hardware vendors' backends such as NVIDIA CUDA and OpenCL making them the only OpenACC compilers supporting various many-core architectures. About the speaker Stéphane Bihan is co-funder and currently Director of Sales and Marketing at CAPS enterprise. He has held several R&D positions in companies such as ARC international plc in London, Canon Research Center France, ACE compiler experts in Amsterdam and the INRIA r...

  15. New Synthesis of .alfa.,.omega.-Diiodoalkynes and Capped Iodobutadiynes

    Czech Academy of Sciences Publication Activity Database

    Hlavatý, Jaromír; Kavan, Ladislav; Štícha, M.

    - (2002), s. 705-706 ISSN 1472-7781 R&D Projects: GA ČR GA203/00/0634 Institutional research plan: CEZ:AV0Z4040901 Keywords : .alfa.,. omega .-diiodoalkynes * capped iodobutadiynes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.181, year: 2002

  16. Translation initiation mediated by nuclear cap-binding protein complex.

    Science.gov (United States)

    Ryu, Incheol; Kim, Yoon Ki

    2017-04-01

    In mammals, cap-dependent translation of mRNAs is initiated by two distinct mechanisms: cap-binding complex (CBC; a heterodimer of CBP80 and 20)-dependent translation (CT) and eIF4E-dependent translation (ET). Both translation initiation mechanisms share common features in driving cap- dependent translation; nevertheless, they can be distinguished from each other based on their molecular features and biological roles. CT is largely associated with mRNA surveillance such as nonsense-mediated mRNA decay (NMD), whereas ET is predominantly involved in the bulk of protein synthesis. However, several recent studies have demonstrated that CT and ET have similar roles in protein synthesis and mRNA surveillance. In a subset of mRNAs, CT preferentially drives the cap-dependent translation, as ET does, and ET is responsible for mRNA surveillance, as CT does. In this review, we summarize and compare the molecular features of CT and ET with a focus on the emerging roles of CT in translation. [BMB Reports 2017; 50(4): 186-193].

  17. Effect of capping agents on optical and antibacterial properties

    Indian Academy of Sciences (India)

    Cadmium selenide quantum dots (CdSe QDs) were synthesized in aqueous phase by the freezing temperature injection technique using different capping agents (viz. thioglycolic acid, 1-thioglycerol, L-cysteine). Absorption spectra of CdSe QDs exhibited a blue shift as compared to its bulk counterpart, which is an indication ...

  18. Diagnostic criteria for cryopyrin-associated periodic syndrome (CAPS)

    NARCIS (Netherlands)

    Kuemmerle-Deschner, Jasmin B.; Ozen, Seza; Tyrrell, Pascal N.; Kone-Paut, Isabelle; Goldbach-Mansky, Raphaela; Lachmann, Helen; Blank, Norbert; Hoffman, Hal M.; Weissbarth-Riedel, Elisabeth; Hugle, Boris; Kallinich, Tilmann; Gattorno, Marco; Gul, Ahmet; Ter Haar, Nienke; Oswald, Marlen; Dedeoglu, Fatma; Cantarini, Luca; Benseler, Susanne M.

    2017-01-01

    Cryopyrin-associated periodic syndrome (CAPS) is a rare, heterogeneous disease entity associated with NLRP3 gene mutations and increased interleukin-1 (IL-1) secretion. Early diagnosis and rapid initiation of IL-1 inhibition prevent organ damage. The aim of the study was to develop and validate

  19. Facially amphiphilic thiol capped gold and silver nanoparticles

    Indian Academy of Sciences (India)

    Wintec

    *For correspondence. Also at the Chemical Biology Unit,. Jawaharlal Nehru Centre for Advanced Scientific Research,. Bangalore 560 064. Facially amphiphilic thiol capped gold and silver nanoparticles. †. SHREEDHAR BHAT a and UDAY MAITRA*. Department of Organic Chemistry, Indian Institute of Science, Bangalore ...

  20. Working on an LHC dipole end-cap

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A metal worker constructs an end-cap for an LHC dipole magnet. These magnets will be used to bend the proton beams around the LHC, which is due to start up in 2008. The handmade prototype seen here will be used to make a mold from which the final set of components will be made for the accelerator.

  1. Primate numts and reticulate evolution of capped and golden leaf ...

    Indian Academy of Sciences (India)

    Capped and golden leaf monkeys might have to be assigned to a new genus to reconcile their unique evolutionary history. Additionally, northeast India appears to be a 'hot spot' for lineages that ... Author Affiliations. K Praveen Karanth1. Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India ...

  2. Primate numts and reticulate evolution of capped and golden leaf ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India ... To test this hybridization scenario, I analysed nuclear copies of the mitochondrial cytochrome b gene (numts) from capped, golden and Phayre's leaf monkeys. These numts ... According to Oates et al (1994), there are around five species.

  3. CucCAP - Developing genomic resources for the cucurbit community

    Science.gov (United States)

    The U.S. cucurbit community has initiated a USDA-SCRI funded cucurbit genomics project, CucCAP: Leveraging applied genomics to increase disease resistance in cucurbit crops. Our primary objectives are: develop genomic and bioinformatic breeding tool kits for accelerated crop improvement across the...

  4. External caps: An approach to stress reduction in balloons

    Science.gov (United States)

    Hazlewood, K. H.

    Recent findings of the catastrophic balloon failures investigation in the U.S.A. indicate that very large gross inflations, in balloons using present design philosophy, over-stress currently available materials. External caps are proposed as an economic approach to reducting those stresses to an acceptable level.

  5. Aspiration of a perforated pen cap: complete tracheal obstruction ...

    African Journals Online (AJOL)

    Foreign body aspiration is a common but underestimated event in children with potentially fatal outcome. Because of unreliable histories and inconsistent clinical and radiologic findings, diagnosis and treatment can represent a challenge. Inhaled pen caps predispose for complete airway obstruction and are difficult to ...

  6. Moving one of the ATLAS end-cap calorimeters

    CERN Multimedia

    Claudia Marcelloni

    2007-01-01

    One of the end-cap calorimeters for the ATLAS experiment is moved using a set of rails. This calorimeter will measure the energy of particles that are produced close to the axis of the beam when two protons collide. It is kept cool inside a cryostat to allow the detector to work at maximum efficiency.

  7. Optical Properties of ZnO Nanoparticles Capped with Polymers

    Directory of Open Access Journals (Sweden)

    Atsushi Noguchi

    2011-06-01

    Full Text Available Optical properties of ZnO nanoparticles capped with polymers were investigated. Polyethylene glycol (PEG and polyvinyl pyrrolidone (PVP were used as capping reagents. ZnO nanoparticles were synthesized by the sol-gel method. Fluorescence and absorption spectra were measured. When we varied the timing of the addition of the polymer to the ZnO nanoparticle solution, the optical properties were drastically changed. When PEG was added to the solution before the synthesis of ZnO nanoparticles, the fluorescence intensity increased. At the same time, the total particle size increased, which indicated that PEG molecules had capped the ZnO nanoparticles. The capping led to surface passivation, which increased fluorescence intensity. However, when PEG was added to the solution after the synthesis of ZnO nanoparticles, the fluorescence and particle size did not change. When PVP was added to the solution before the synthesis of ZnO nanoparticles, aggregation of nanoparticles occurred. When PVP was added to the solution after the synthesis of ZnO nanoparticles, fluorescence and particle size increased. This improvement of optical properties is advantageous to the practical usage of ZnO nanoparticles, such as bioimaging

  8. Traditional M e n Caps o f Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    Serap TANRISEVER

    2015-07-01

    Full Text Available Kyrgyzstan has an extraordinarily rich mosaic of folk culture. There is a great importance of wear clothing, crafts and decorative arts in this mosaic. Traditional caps and clothes of Kyrgyzstan are the best elements that reflect the presence of culture, t raditions, geography inhabited, climatic conditions that they already live in. Kyrgyzstan has been trying to keep alive the traditions, styles of lives by using the required crafts and handmade products although the global fashion, time and technological development. According to research, it has still been seen that the caps and clothes of Kyrgyzstan are being used less in daily life. Caps, Kalpak , Tebetey, Malakay, are some of the best known extant that come to this age related with the traditions of ca p s of Kyrgyzstan’s men . In this research, it has been worked of decorations of Kirghiz men caps , specialties of color and design, techniques of sewing, characteristics of mold and fabrics, Moreover the place and the meaning of the titles has been trying to determine in the cultural life. The scan method has been used by doing regional research.

  9. Seismic explosion sources on an ice cap - Technical considerations

    Science.gov (United States)

    Shulgin, Alexey; Thybo, Hans

    2015-03-01

    Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed as a strong ice wave. The ice cap leads to low transmission of energy into the crust such that charges need be larger than in conventional onshore experiments to obtain reliable seismic signals. The strong reflection coefficient at the base of the ice generates strong multiples which may mask for secondary phases. This effect may be crucial for acquisition of reflection seismic profiles on ice caps. Our experience shows that it is essential to use optimum depth for the charges and to seal the boreholes carefully.

  10. Guardian Caps: What's the Impact?

    Science.gov (United States)

    Jenny, Seth E.; Rouse, Wardell; Seibles, Ashlie

    2017-01-01

    Reported sport-related concussion rates have dramatically increased recently. In response, the Guardian company has emerged as a leading manufacturer of soft-shell helmet covers. The "Guardian Cap" is a foam padded covering that fits over a helmet that aims to reduce the impact of collisions and lessen the chance of a concussion. The…

  11. Indirect pulp capping in primary molar using glass ionomer cements

    Directory of Open Access Journals (Sweden)

    Murtia Metalita

    2014-12-01

    Full Text Available Background: Indirect pulp capping in primary teeth, however, is more rarely conducted than permanent teeth, since it thought to have low impact and most suggestion is for taking caries lesion aggressively on primary teeth. Purpose: The study was aimed to evaluate the subjective complaint, clinical symptom, and radiographic appearance of indirect pulp capping treatment using glass ionomers cements in primary molar. Methods: Sixteen children in range of age 6 to 8 years old, who visited Clinic of Pediatric Dentistry Universitas Airlangga Dental Hospital, Surabaya Indonesia, were the subject of study. They had one occlusal dental caries on one side of maxillary or mandibular primary molar with the diagnose of pulpitis reversible. The experimental group, had indirect pulp capping treatment with glass ionomer cements (GC Fuji VII®, while the control group, had indirect pulp capping treatment with calcium hydroxide (Metapaste. Each group was filled with GC Fuji IX® as permanent restoration. After one week, one month, and three months later, the observations were made on subjective complaint, clinical symptom, and radiographic appearance. Results: The results showed no subjective complaint such as pain or problem on mastication; no negative clinical symptoms such as pain on palpation, gingivitis or periodontitis, and abnormal tooth mobility; no negative radiographic appearance such as pathological apical radioluscency, internal or external resorbtion, and change of ligament periodontal widthafter the treatment. Conclusion: The study suggested that indirect pulp capping treatment using glass ionomer cement materials on primary teeth might be considered to be the treatment choice.Latar belakang: Indirect pulp capping pada gigi sulung lebih jarang dilakukan dibandingkan gigi permanen, karena dianggap memiliki dampak yang rendah dan sebagian besar menyarankan untuk mengambil lesi karies secara agresif pada gigi sulung. Tujuan: Penelitian ini bertujuan

  12. Coccolithophores put a CAP on calcification and carbon

    Science.gov (United States)

    Rickaby, R. E. M.; Lee, R. B. Y.; Mavridou, D. A. I.; Papadakos, G.; McClelland, H. L. O.; Anderson, C. J.

    2014-12-01

    Unlike the majority of biomineralization, mediated via proteins, the coccolithophores employ acidic polysaccharides (CAPs) as the template for the multitude of intricate calcium carbonate liths which are precipitated inside their cells and expelled to form an external spherical armour. Massive accumulations of these calcium carbonate coccoliths (we estimate a flux of ~ 6x1025 liths/year) form sediments on the deep seafloor, a dominant sink of carbon from the atmosphere over geological timescales, and a buffer for seawater chemistry. This acidic, coccolith-associated polysaccharide (CAP) plays a dual role, likely determined by the calcifying vesicle chemistry, promoting and limiting precipitation. We have developed and demonstrated novel techniques for the extraction and characterisation of these biomineral-mediating molecules, encapsulated and preserved within liths from sediments as old as the Mesozoic. Modern cultures of extant coccolithophores show that the composition of CAP is distinctive for different species, and even strains of e.g. Emiliania huxleyi, suggestive that interactions with galacturonic acid residues are key to dictating the architecture of the liths. Furthermore, it appears that the galacturonic acid content reflects an adaptive response of the CAP to the chemistry within the coccolith vesicle where calcification is induced; in particular the size of the internal carbon pool and inferred saturation state. Extraction of CAPs from the Coccolithale fraction of sediments suggests that the galacturonic acid content of these relatively large and inefficient carbon concentrators evolves in response to declining CO2 availability and thus may provide a novel means for reconstructing paleo pCO2.

  13. Coastal Change Analysis Program (C-CAP) Regional Land Cover Data and Change Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  14. NOAA's Coastal Change Analysis Program (C-CAP) 2001 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  15. NOAA's Coastal Change Analysis Program (C-CAP) 1985 Regional Land Cover Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  16. NOAA's Coastal Change Analysis Program (C-CAP) 1975 Regional Land Cover Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  17. NOAA's Coastal Change Analysis Program (C-CAP) 1992 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  18. Innovative Capping Technology To Prevent The Migration of Toxic Chemicals From Contaminated Sediments

    Science.gov (United States)

    Capping is a common strategy for decreasing the risk associated with contaminated sediments in lakes and streams. Historically, caps have been designed to physically isolate contaminated sediments and prevent the transport of contaminants from sediments into the water above them...

  19. NOAA's Coastal Change Analysis Program (C-CAP) 2010 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  20. NOAA's Coastal Change Analysis Program (C-CAP) 1996 Regional Land Cover Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  1. NOAA's Coastal Change Analysis Program (C-CAP) 1992 Regional Land Cover Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  2. NOAA's Coastal Change Analysis Program (C-CAP) 2016 Regional Land Cover Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  3. NOAA's Coastal Change Analysis Program (C-CAP) 2006 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  4. NOAA's Coastal Change Analysis Program (C-CAP) 1996 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  5. NOAA's Coastal Change Analysis Program (C-CAP) 1985 Forest Fragmentation Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  6. Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker

    CERN Document Server

    Adler, Volker; Ageron, Michel; Agram, Jean-Laurent; Atz, Bernd; Barvich, Tobias; Baulieu, Guillaume; Beaumont, Willem; Beissel, Franz; Bergauer, Thomas; Berst, Jean-Daniel; Blüm, Peter; Bock, E; Bogelsbacher, F; de Boer, Wim; Bonnet, Jean-Luc; Bonnevaux, Alain; Boudoul, Gaelle; Bouhali, Othmane; Braunschweig, Wolfgang; Bremer, R; Brom, Jean-Marie; Butz, Erik; Chabanat, Eric; Chabert, Eric Christian; Clerbaux, Barbara; Contardo, Didier; De Callatay, Bernard; Dehm, Philip; Delaere, Christophe; Della Negra, Rodolphe; Dewulf, Jean-Paul; D'Hondt, Jorgen; Didierjean, Francois; Dierlamm, Alexander; Dirkes, Guido; Dragicevic, Marko; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Esser, Hans; Estre, Nicolas; Fahrer, Manuel; Feld, Lutz; Fernández, J; Florins, Benoit; Flossdorf, Alexander; Flucke, Gero; Flügge, Günter; Fontaine, Jean-Charles; Freudenreich, Klaus; Frey, Martin; Friedl, Markus; Furgeri, Alexander; Giraud, Noël; Goerlach, Ulrich; Goorens, Robert; Graehling, Philippe; Grégoire, Ghislain; Gregoriev, E; Gross, Laurent; Hansel, S; Haroutunian, Roger; Hartmann, Frank; Heier, Stefan; Hermanns, Thomas; Heydhausen, Dirk; Heyninck, Jan; Hosselet, J; Hrubec, Josef; Jahn, Dieter; Juillot, Pierre; Kaminski, Jochen; Karpinski, Waclaw; Kaussen, Gordon; Keutgen, Thomas; Klanner, Robert; Klein, Katja; König, Stefan; Kosbow, M; Krammer, Manfred; Ledermann, Bernhard; Lemaître, Vincent; De Lentdecker, Gilles; Linn, Alexander; Lounis, Abdenour; Lübelsmeyer, Klaus; Lumb, Nicholas; Maazouzi, Chaker; Mahmoud, Tariq; Michotte, Daniel; Militaru, Otilia; Mirabito, Laurent; Müller, Thomas; Neukermans, Lionel; Ollivetto, C; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pein, Uwe; Pernicka, Manfred; Perriès, Stephane; Piaseki, C; Pierschel, Gerhard; Piotrzkowski, Krzysztof; Poettgens, Michael; Pooth, Oliver; Rouby, Xavier; Sabellek, Andreas; Schael, Stefan; Schirm, Norbert; Schleper, Peter; Schmitz, Stefan Antonius; Schultz von Dratzig, Arndt; Siedling, Rolf; Simonis, Hans-Jürgen; Stahl, Achim; Steck, Pia; Steinbruck, G; Stoye, Markus; Strub, Roger; Tavernier, Stefaan; Teyssier, Daniel; Theel, Andreas; Trocmé, Benjamin; Udo, Fred; Van der Donckt, M; Van der Velde, C; Van Hove, Pierre; Vanlaer, Pascal; Van Lancker, Luc; Van Staa, Rolf; Vanzetto, Sylvain; Weber, Markus; Weiler, Thomas; Weseler, Siegfried; Wickens, John; Wittmer, Bruno; Wlochal, Michael; De Wolf, Eddi A; Zhukov, Valery; Zoeller, Marc Henning

    2009-01-01

    The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing.

  7. Cap snatching in yeast L-BC double-stranded RNA totivirus.

    Science.gov (United States)

    Fujimura, Tsutomu; Esteban, Rosa

    2013-08-16

    Yeast L-A double-stranded RNA virus furnishes its transcript with a 5' cap structure by a novel cap-snatching mechanism in which m(7)Gp from a host mRNA cap structure is transferred to the 5'-diphosphate terminus of the viral transcript. His-154 of the coat protein Gag forms an m(7)Gp adduct, and the H154R mutation abolishes both m(7)Gp adduct formation and cap snatching. Here we show that L-BC, another totivirus closely related to L-A, also synthesizes 5'-diphosphorylated transcripts and transfers m(7)Gp from mRNA to the 5' termini of the transcripts. L-BC Gag also covalently binds to the cap structure and the mutation H156R, which corresponds to H154R of L-A Gag, abolishes cap adduct formation. Cap snatching of the L-BC virus is very similar to that of L-A; N7 methylation of the mRNA cap is essential for cap donor activity, and only 5'-diphosphorylated RNA is used as cap acceptor. L-BC cap snatching is also activated by viral transcription. Furthermore, both viruses require Mg(2+) and Mn(2+) for cap snatching. These cations are not only required for transcription activation but also directly involved in the cap transfer process. These findings support our previous proposal that the cap-snatching mechanism of the L-A virus is shared by fungal totiviruses closely related to L-A. Interestingly, L-A and L-BC viruses accept either viral transcript as cap acceptor in vitro. Because L-A and L-BC viruses cohabit in many yeast strains, it raises the possibility that their cohabitation in the same host may be beneficial for their mutual cap acquisition.

  8. An ATLAS inner detector end-cap is placed in its cryostat

    CERN Multimedia

    2007-01-01

    The instrumentation housed inside the inner end-cap must be kept cool to avoid thermal noise. This cooling is achieved on ATLAS by placing the end-cap inside a liquid argon cryostat. The end-cap measures particles that are produced close to the direction of the beam pipe and would otherwise be missed.

  9. 40 CFR 1060.521 - How do I test fuel caps for permeation emissions?

    Science.gov (United States)

    2010-07-01

    ... tank and fuel cap meet emission standards by certifying them separately or by combining the separate... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test fuel caps for permeation... EQUIPMENT Test Procedures § 1060.521 How do I test fuel caps for permeation emissions? If you measure a fuel...

  10. Molecular Basis of Transcription-Coupled Pre-mRNA Capping

    NARCIS (Netherlands)

    Martinez-Rucobo, Fuensanta W.; Kohler, Rebecca; van de Waterbeemd, Michiel|info:eu-repo/dai/nl/412537761; Heck, Albert J R|info:eu-repo/dai/nl/105189332; Hemann, Matthias; Herzog, Franz; Stark, Holger; Cramer, Patrick

    2015-01-01

    Capping is the first step in pre-mRNA processing, and the resulting 5'-RNA cap is required for mRNA splicing, export, translation, and stability. Capping is functionally coupled to transcription by RNA polymerase (Pol) II, but the coupling mechanism remains unclear. We show that efficient binding of

  11. Ectopic peripontine arcuate fibres, a novel finding in pontine tegmental cap dysplasia

    NARCIS (Netherlands)

    Caan, Matthan W. A.; Barth, Peter G.; Niermeijer, Jikke-Mien; Majoie, Charles B.; Poll-The, Bwee Tien

    2014-01-01

    Pontine Tegmental Cap Dysplasia (PTCD) is a recently described hindbrain malformation presenting hypoplasia of the ventral pons, and a "pontine tegmental cap". Previous DTI studies identified ectopic transversely oriented nerve fibres in the cap, and absence of transverse fibre bundles in the

  12. Green wet chemical route to synthesize capped CdSe quantum dots

    Indian Academy of Sciences (India)

    In the present work, we report green synthesis of tartaric acid (TA) and triethanolamine (TEA) capped cadmium selenide quantum dots (CdSe QDs) employing chemical bath deposition (CBD) method. The mechanism of capping using non-toxic binary capping agents is also discussed. Stable QDs of various sizes were ...

  13. Palaeoceanographic Variability of the Benguela Upwelling System Depending on the Northern Hemisphere Glaciation (NHG) - Indicated by Organic-Walled Dinoflagellates

    Science.gov (United States)

    Bork, M.

    2003-12-01

    The causes and effects of the intensification of growth of the northern Hemisphere ice caps at around 3.2 and 2.74 Ma BP are still unclear. Possible causes are changes in the global ocean circulation and the global carbon cycle, which might have resulted from tectonic processes, solar insolation changes, or the interaction between both processes. The Benguela upwelling area forms a key area within the global ocean system. Here, warm and saline Indian Ocean waters enter the South Atlantic Ocean and are transported to the north. Variability of this inflow may thus result in changes in deep-water production in the North Atlantic, thereby influencing the global thermohaline circulation. Furthermore, the Benguela area is characterized by extremely high bioproductivity in surface waters as a result of year-round upwelling. Variations in the upwelling intensity might lead to changes in atmospheric ¤CO2. To study the changes in the circulation and the upwelling intensity, within this region organic-walled dinoflagellate cysts from two high-resolution cores (ODP 1084 and1082) covering the time interval from 3.3 to 2.5 Ma BP were investigated. Due to their sensitiveness to ecological parameters, organic-walled dinoflagellates reflect oceanographic characteristics keenly. The analyses discover clear distribution differences of individual species, especially of those that are sensible or resistant against aerobic decay. The sensible species, (Protoperidinium and Echinidinium), have their highest abundance from 2.76 to 2.73 Ma BP, a time interval in which the resistant species show no significant changes in their abundance. This implies that during this time interval the oxygen was reduced in the deep- and porewater suggesting that the global ocean deepwater circulation was weakened. Comparing these results with the known intensification of the NHG at around 2.74 Ma BP leads to the speculation that the increasing of ice caps in the northern hemisphere is highly associated with

  14. Environmentally Sustainable Agriculture and Future Developments of the CAP

    DEFF Research Database (Denmark)

    Ørsted Nielsen, Helle; Branth Pedersen, Anders; Christensen, Tove

    2009-01-01

    Recent reforms of the European Union’s Common Agricultural Policy (CAP) have set in motion a process of increased market orientation in the agricultural sector, a process that will be intensified by trade liberalization if an agreement is reached under the World Trade Organization (WTO......). It is widely expected that both CAP reforms and a WTO agreement will also lead to a more environmentally friendly European agriculture. It is conceivable, however, that market demand would instead provide renewed incentives for intensive agricultural production. Opening European agriculture to more competition...... in the world market could increase pressure to slacken regulatory requirements on agriculture. Thus, the question of whether liberalization will hinder or promote environmentally sustainable production methods in agriculture is unresolved. This paper analyses different scenarios of agricultural policy...

  15. Actin microfilaments in presumptive statocytes of root caps and coleoptiles

    Science.gov (United States)

    White, R. G.; Sack, F. D.

    1990-01-01

    Rhodamine-phalloidin was used to determine the distribution of actin microfilament bundles (mfb) in cells thought to be the site of gravity perception (statocytes) in coleoptiles and root caps of Zea mays and Hordeum vulgare. In coleoptile cells, amyloplasts were usually observed in close proximity to thick mfb, which often appeared to divide into finer mfb adjacent to individual amyloplasts. The nucleus in these cells was surrounded by an extensive network of mfb, which were connected to thicker transvacuolar mfb. Columella cells of the root cap contained an extensive reticulum of fine mfb throughout the protoplast, but lacked the much thicker mfb seen in coleoptile cells. The distribution and extent of mfb observed in fixed cells correlates with patterns of streaming and amyloplast movement seen in living cells. A possible role for actin mfb in the perception of gravity is discussed.

  16. Nanoscale gadolinium oxide capping layers on compositionally variant gate dielectrics

    KAUST Repository

    Alshareef, Husam N.

    2010-11-19

    Metal gate work function enhancement using nanoscale (1.0 nm) Gd2O3 interfacial layers has been evaluated as a function of silicon oxide content in the HfxSiyOz gate dielectric and process thermal budget. It is found that the effective work function tuning by the Gd2O3 capping layer varied by nearly 400 mV as the composition of the underlying dielectric changed from 0% to 100% SiO2, and by nearly 300 mV as the maximum process temperature increased from ambient to 1000 °C. A qualitative model is proposed to explain these results, expanding the existing models for the lanthanide capping layer effect.

  17. Thermal analysis of the airflow around ATLAS muon end cap

    CERN Document Server

    Gasser, D

    2003-01-01

    A thermal analysis of the airflow inside the UX15 cavern and through the ATLAS detector is presented. This study is done using a CFD (Computational Fluid Dynamics) model. This model includes a simplified geometry of the detector and the experimental cavern, the ventilation flow rate and the released heat dissipation figures are taken into account. This analysis aims at estimate the temperature gradients that develop in the muons end cap area. Indeed, light rays seen by CCD camera will be used in this area in order to align the muon chambers. The rays should not be too much distorted by temperature difference, which would hinder the chamber alignment. The simulation results show that a light ray projected through the whole end cap area should not encounter a gradient higher than 5 K. Nevertheless, the results of this analysis are valid if and only if the spaces represented as empty in the model are allowed to remain empty in ATLAS.

  18. Collapse mechanisms and strength prediction of reinforced concrete pile caps

    DEFF Research Database (Denmark)

    Jensen, Uffe G.; Hoang, Linh Cao

    2012-01-01

    This paper describes an upper bound plasticity approach for strength prediction of reinforced concrete pile caps. A number of collapse mechanisms are identified and analysed. The procedure leads to an estimate of the load-carrying capacity and an identification of the critical collapse mechanism....... Calculations have been compared with nearly 200 test results found in the literature. Satisfactory agreement has been found. The analyses are conducted on concentrically loaded caps supported by four piles. The paper briefly outlines how the approach may be extended to more complicated loadings and geometries....... It is argued that the upper bound approach may be a useful complement to the widely used lower bound strut-and-tie method. Especially when dealing with strength assessment of existing structures....

  19. Evaluation of management alternatives for LWR hulls and caps

    International Nuclear Information System (INIS)

    Chaudon, L.; Mehling, O.; Cecille, L.; Thiels, G.; Kowa, S.

    1993-01-01

    Hulls and caps resulting from the reprocessing of LWR spent fuels represent one of the major sources of alpha-bearing solid waste generated during the nuclear fuel cycle. The Commission of the European Communities has undertaken considerable R and D efforts on the development of advanced treatment and conditioning methods for this type of waste. In view of the encouraging results achieved, the Commission launched a theoretical assessment study on cladding waste management. Six practical or potential schemes were identified and elaborated: direct cementation, decontamination prior to cementation, rolling before cementation, rolling followed by embedding in graphite, compaction, and melting in a cold crucible. The economic aspects of each management option were also investigated. This included the assessment of the plant (treatment, conditioning and interim storage), transport and disposal costs. Further consideration will be required to define the best management option for 'cap' wastes. Transport and disposal costs will also require further analysis from an industrial standpoint

  20. Tinjauan Tekno Ekonomi Cap Batik dari Bahan Kayu

    Directory of Open Access Journals (Sweden)

    Lies Susilaning Sri Hastuti

    2016-04-01

    Full Text Available Batik telah diakui sebagai warisan dunia, hal ini yang memberikan semangat kepada industri batik untuk dapat berkembang dan menghasilkan produk yang bermutu. Salah sau alat yang digunakan dalam membatik adalah canting cap yang umumnya terbuat dari tembaga. Pada tinjauan ini yang dilakukan adalah perhitungan tekno ekonomi terhadap canting kayu.Hasil tinjauan adalah sebagai berikut: Canting kayu dibuat dengan dua cara yaitu Jig-Saw Rekat dan Ukir Rekat. Kapasitas produksi cara Jigsaw Rekat adalah 4 buah/hari. Diasumsikan dalam 1 (satu bulan ada 25 hari kerja sehingga kapasitas produksi per bulan adalah 100 buah canting kayu JigSaw Rekat dan 75 buah canting kayu Ukir Rekat. Jumlah total produksi adalah 175 buah canting kayu. Tenaga kerja yang dibutuhkan adalah 1 (satu orang pimpinan dan 20 orang karyawan. Modal yang dibuuhkan adalah Rp 87.740.000,-, biaya produksi Rp 20.573.334,-/bulan dan harga pokok Rp 120.000,-. Harga jual diperkirakan Rp 250.000,-/canting mengingat cara pengerjaannya yang cukup rumit. Keuntungan yang didapat Rp 19.700.166,-/bulan dan BEP=70 buah canting serta model diperkirakan dapat kembali dalam waktu 1,5 (satu setengah bulan.Kesimpulan yang dapat ditetapkan adalah bahwa industri caning cap kayu merupakan industri yang dapat dikembangkan serta mempunyai prospek yang baik dalam mendukung perkembangan industri batik saat ini meskipun canting cap kayu mempunyai kelemahan yaitu desain motif yang dapat diterapkan pada canting kayu terbatas pada motif yang tidak menggunakan isen-isen. Kata Kunci: batik, canting cap kayu, tekno ekonomi

  1. Characterization of Mars' seasonal caps using neutron spectroscopy

    Science.gov (United States)

    Prettyman, T.H.; Feldman, W.C.; Titus, T.N.

    2009-01-01

    Mars' seasonal caps are characterized during Mars years 26 and 27 (April 2002 to January 2006) using data acquired by the 2001 Mars Odyssey Neutron Spectrometer. Time-dependent maps of the column abundance of seasonal CO 2 surface ice poleward of 60?? latitude in both hemispheres are determined from spatially deconvolved, epithermal neutron counting data. Sources of systematic error are analyzed, including spatial blurring by the spectrometer's broad footprint and the seasonal variations in the abundance of noncondensable gas at high southern latitudes, which are found to be consistent with results reported by Sprague et al. (2004, 2007). Corrections for spatial blurring are found to be important during the recession, when the column abundance of seasonal CO2 ice has the largest latitude gradient. The measured distribution and inventory of seasonal CO2 ice is compared to simulations by a general circulation model (GCM) calibrated using Viking lander pressure data, cap edge functions determined by thermal emission spectroscopy, and other nuclear spectroscopy data sets. On the basis of the amount of CO2 cycled through the caps during years 26 and 27, the gross polar energy balance has not changed significantly since Viking. The distribution of seasonal CO2 ice is longitudinally asymmetric: in the north, deposition rates of CO2 ice are elevated in Acidalia, which is exposed to katabatic winds from Chasma Borealis; in the south, CO2 deposition is highest near the residual cap. During southern recession, CO 2 ice is present longer than calculated by the GCM, which has implications for the local polar energy balance. Copyright 2009 by the American Geophysical Union.

  2. Polar cap index as a proxy for hemispheric Joule heating

    DEFF Research Database (Denmark)

    Chun, F.K.; Knipp, D.J.; McHarg, M.G.

    1999-01-01

    input into the polar cap, we propose to use PC as a proxy for the hemispheric Joule heat production rate (JH). In this study, JH is estimated from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. We fit hourly PC values to hourly averages of JH. Using a data base approximately...... is as equally accurate. Thus the single station PC index appears to provide a quick estimate of, and is an appropriate proxy for, the hemispheric Joule heating rate....

  3. Cavity Attenuated Phase Shift (CAPS) Monitor Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, Arthur J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-04-01

    The CAPS PMex monitor is a cavity attenuated phase shift extinction instrument. It operates as an optical extinction spectrometer, using a visible-light-emitting diode (LED) as the light source, a sample cell incorporating two high-reflectivity mirrors centered at the wavelength of the LED, and a vacuum photodiode detector. Its efficacy is based on the fact that aerosols are broadband scatterers and absorbers of light.

  4. Enhanced gravitropism of roots with a disrupted cap actin cytoskeleton

    Science.gov (United States)

    Hou, Guichuan; Mohamalawari, Deepti R.; Blancaflor, Elison B.

    2003-01-01

    The actin cytoskeleton has been proposed to be a major player in plant gravitropism. However, understanding the role of actin in this process is far from complete. To address this problem, we conducted an analysis of the effect of Latrunculin B (Lat B), a potent actin-disrupting drug, on root gravitropism using various parameters that included detailed curvature kinetics, estimation of gravitropic sensitivity, and monitoring of curvature development after extended clinorotation. Lat B treatment resulted in a promotion of root curvature after a 90 degrees reorientation in three plant species tested. More significantly, the sensitivity of maize (Zea mays) roots to gravity was enhanced after actin disruption, as determined from a comparison of presentation time of Lat B-treated versus untreated roots. A short 10-min gravistimulus followed by extended rotation on a 1-rpm clinostat resulted in extensive gravitropic responses, manifested as curvature that often exceeded 90 degrees. Application of Lat B to the cap or elongation zone of maize roots resulted in the disruption of the actin cytoskeleton, which was confined to the area of localized Lat B application. Only roots with Lat B applied to the cap displayed the strong curvature responses after extended clinorotation. Our study demonstrates that disrupting the actin cytoskeleton in the cap leads to the persistence of a signal established by a previous gravistimulus. Therefore, actin could function in root gravitropism by providing a mechanism to regulate the proliferation of a gravitropic signal originating from the cap to allow the root to attain its correct orientation or set point angle.

  5. Structural basis for capping protein sequestration by myotrophin (V-1).

    Science.gov (United States)

    Zwolak, Adam; Fujiwara, Ikuko; Hammer, John A; Tjandra, Nico

    2010-08-13

    Capping protein (CP) is a ubiquitously expressed, heterodimeric 62-kDa protein that binds the barbed end of the actin filament with high affinity to block further filament elongation. Myotrophin (V-1) is a 13-kDa ankyrin repeat-containing protein that binds CP tightly, sequestering it in a totally inactive complex in vitro. Here, we elucidate the molecular interaction between CP and V-1 by NMR. Specifically, chemical shift mapping and intermolecular paramagnetic relaxation enhancement experiments reveal that the ankyrin loops of V-1, which are essential for V-1/CP interaction, bind the basic patch near the joint of the alpha tentacle of CP shown previously to drive most of the association of CP with and affinity for the barbed end. Consistently, site-directed mutagenesis of CP shows that V-1 and the strong electrostatic binding site for CP on the barbed end compete for this basic patch on CP. These results can explain how V-1 inactivates barbed end capping by CP and why V-1 is incapable of uncapping CP-capped actin filaments, the two signature biochemical activities of V-1.

  6. Results from the First Validation Phase of CAP code

    International Nuclear Information System (INIS)

    Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon

    2010-01-01

    The second stage of Safety Analysis Code Development for Nuclear Power Plants was lunched on Apirl, 2010 and is scheduled to be through 2012, of which the scope of work shall cover from code validation to licensing preparation. As a part of this project, CAP(Containment Analysis Package) will follow the same procedures. CAP's validation works are organized hieratically into four validation steps using; 1) Fundamental phenomena. 2) Principal phenomena (mixing and transport) and components in containment. 3) Demonstration test by small, middle, large facilities and International Standard Problems. 4) Comparison with other containment codes such as GOTHIC or COMTEMPT. In addition, collecting the experimental data related to containment phenomena and then constructing the database is one of the major works during the second stage as a part of this project. From the validation process of fundamental phenomenon, it could be expected that the current capability and the future improvements of CAP code will be revealed. For this purpose, simple but significant problems, which have the exact analytical solution, were selected and calculated for validation of fundamental phenomena. In this paper, some results of validation problems for the selected fundamental phenomena will be summarized and discussed briefly

  7. Completion of the first TRT End-cap

    CERN Multimedia

    Catinaccio, A; Rohne, O

    On July 1, the first end-cap of the ATLAS Transition Radiation Tracker (TRT) was successfully completed in terms of the integration of the wheels assembled in Russia with their front-end electronics. The two groups of the detector, fully assembled and equipped with front-end electronics, were rotated from their horizontal position during stacking to their nominal vertical position, in which they will be integrated with the corresponding end-cap silicon-strip (SCT) detector towards the end of 2005, before installation into ATLAS in spring 2006. After starting the assembly in the SR building one year ago, the TRT team reached this important milestone, which marks the final realization and validation of the engineering concept developed by the CERN DT1 (ex-TA1) and ATT teams. A TRT end-cap consists of two sets of identical and independent wheels. The first type of wheels (type A, 12 wheels, positioned closest to the primary interaction point) contains 6144 radial straws positioned in eight successive layers s...

  8. The thermospheric effects of a rapid polar cap expansion

    Directory of Open Access Journals (Sweden)

    D. W. Idenden

    Full Text Available In a previous publication we used results from a coupled thermosphere-ionosphere-plasmasphere model to illustrate a new mechanism for the formation of a large-scale patch of ionisation arising from a rapid polar cap expansion. Here we describe the thermospheric response to that polar cap expansion, and to the ionospheric structure produced. The response is dominated by the energy and momentum input at the dayside throat during the expansion phase itself. These inputs give rise to a large-scale travelling atmospheric disturbance (TAD that propagates both antisunward across the polar cap and equatorward at speeds much greater than both the ion drifts and the neutral winds. We concentrate only on the initially poleward travelling disturbance. The disturbance is manifested in the neutral temperature and wind fields, the height of the pressure level surfaces and in the neutral density at fixed heights. The thermospheric effects caused by the ionospheric structure produced during the expansion are hard to discern due to the dominating effects of the TAD.

    Key words. Ionosphere (ionosphere · atmosphere interaction; modeling and forecasting; plasma convection.

  9. Commissioning Test of ATLAS End-Cap Toroidal Magnets

    CERN Document Server

    Dudarev, A; Foussat, A; Benoit, P; Jeckel, M; Olyunin, A; Kopeykin, N; Stepanov, V; Deront, L; Olesen, G; Ponts, X; Ravat, S; Sbrissa, K; Barth, J; Bremer, J; Delruelle, J; Metselaar, J; Pengo, R; Pirotte, O; Buskop, J; Baynham, D E; Carr, F S; Holtom, E

    2009-01-01

    The system of superconducting toroids in the ATLAS experiment at CERN consists of three magnets. The Barrel Toroid was assembled and successfully tested in 2006. Next, two End-Cap Toroids have been tested on surface at 77 K and installed in the cavern, 100-m underground. The End Cap Toroids are based on Al stabilized Nb-Ti/Cu Rutherford cables, arranged in double pancake coils and conduction cooled at 4.6 K. The nominal current is 20.5 kA at 4.1 T peak field in the windings and the stored energy is 250 MJ per toroid. Prior to final testing of the entire ATLAS Toroidal system, each End Cap Toroid passed a commissioning test up to 21 kA to guarantee a reliable performance in the final assembly. In this paper the test results are described. It includes the stages of test preparation, isolation vacuum pumping and leak testing, cooling down, step-by-step charging to full current, training quenches and quench recovery. By fast discharges the quench detection and protection system was checked to demonstrate a safe e...

  10. Last End Cap Toroid installation : The Pharaonic enterprise

    CERN Document Server

    Arnaud Foussat

    After the successful and impressive transport feat from Building 191 to Point 1 was carried out by the Friderici crew on 28th June, the second and last Toroid End Cap, ECT-C, was transferred into the surface building, SX1, on 2nd July. The ECT-C was installed in the ATLAS cavern on the C-side on 12th July. As the person responsible for the project, in my opinion, one of the crucial points of this project was to design all the tooling and installation sequences taking into account the building infrastructure dimensional constraints. View of the ECT installation tooling and preparation for the ECT-C descent into the ATLAS 80m-shaft by the ATLAS magnet group and DBS teams. The movement of the 240-ton magnet and 12-m diameter toroid end-cap was achieved in collaboration with SCALES, a subcontractor company, using a hydraulic gantry able to lower the ECT inside the shaft by 5m below the floor level . This allowed the DBS team to attach the end-cap with the 2 x 140 tons overhead crane and lower it onto the c...

  11. First Wheel of the Hadronic EndCap Calorimeter Completed

    CERN Multimedia

    Oram, C.J.

    2002-01-01

    With the LAr calorimeters well advanced in module production, the attention is turning to Batiment 180 where the calorimeter modules are formed into complete detectors and inserted into their respective cryostats. For the Hadronic End Cap (HEC) Group the task in B180 is to assemble the wheels, rotate them into their final orientation, and put them onto the cradle in front of the End Cap Cryostat. These tasks have been completed for the first HEC wheel in the B180 End Cap Clean Room. Given that this wheel weighs 70 tons the group is very relieved to have established that these gymnastics with the wheel proceed in a routine fashion. To assemble a wheel we take modules that have already been cold tested, do the final electrical testing and locate them onto the HEC wheel assembly table. Four wheels are required in total, each consisting of 32 modules. Wheel assembly is done in the horizontal position, creating a doughnut-like object sitting on the HEC table. The first picture shows the last module being added ...

  12. Population Files for use with CAP88 at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    McNaughton, Michael W [Los Alamos National Laboratory; Brock, Burgandy R [Los Alamos National Laboratory

    2012-07-10

    CAP88 (Clean Air Act Assessment Package 1988) is a computer model developed for the US Environmental Protection Agency to assess the potential dose from radionuclide emissions to air and to demonstrate compliance with the Clean Air Act. It has options to calculate either individual doses, in units of mrem, or a collective dose, also called population dose, in units of person-rem. To calculate the collective dose, CAP88 uses a population file such as LANL.pop, that lists the number of people in each sector (N, NNE, NE, etc.) as a function of distance (1 to 2 km, etc.) out to a maximum radius of 80 km. Early population files are described in the Los Alamos National Laboratory (LANL) Environmental Reports for 1985 (page 14) and subsequent years. LA-13469-MS describes a population file based on the 1990 census. These files have been updated several times, most recently in 2006 for CAP88 version 3. The 2006 version used the US census for 2000. The present paper describes the 2012 updates, using the 2010 census.

  13. Design and implementation of carbon cap and dividend policies

    Energy Technology Data Exchange (ETDEWEB)

    Kunkel, Catherine M. [Energy and Resources Group (United States); Kammen, Daniel M. [Goldman School of Public Policy, University of California, Berkeley, CA 94720-3050 (United States)

    2011-01-15

    An important concept in discussions of carbon management policies is cap and dividend, where some fraction of the revenues of an auction on emission allowances is returned to citizens on an equal per capita basis. This policy tool has some important features; it emphasizes the fact that the atmosphere is a common property resource, and it is a highly transparent measure that can be effectively used to protect the income of low-income individuals. In this paper we examine this policy in the California context, and focus on the costs and impacts of a cap and dividend scheme when applied to carbon emissions associated with electricity, natural gas and transportation services. We find that cap and dividend can effectively be used to address the economic impacts of carbon management policies, making them progressive for the lowest-income members of society. We find that the majority of households receive positive net benefits from the policy even with the government retaining half of the auction revenue. If auction revenues are instead dedicated only to low-income households, the majority of low-income households can be fully compensated even with the state government retaining upwards of 90% of auction revenues for other purposes. (author)

  14. Fourier analysis of polar cap electric field and current distributions

    Science.gov (United States)

    Barbosa, D. D.

    1984-01-01

    A theoretical study of high-latitude electric fields and currents, using analytic Fourier analysis methods, is conducted. A two-dimensional planar model of the ionosphere with an enhanced conductivity auroral belt and field-aligned currents at the edges is employed. Two separate topics are treated. A field-aligned current element near the cusp region of the polar cap is included to investigate the modifications to the convection pattern by the east-west component of the interplanetary magnetic field. It is shown that a sizable one-cell structure is induced near the cusp which diverts equipotential contours to the dawnside or duskside, depending on the sign of the cusp current. This produces characteristic dawn-dusk asymmetries to the electric field that have been previously observed over the polar cap. The second topic is concerned with the electric field configuration obtained in the limit of perfect shielding, where the field is totally excluded equatorward of the auroral oval. When realistic field-aligned current distributions are used, the result is to produce severely distorted, crescent-shaped equipotential contours over the cap. Exact, analytic formulae applicable to this case are also provided.

  15. Magnetic properties of TOAB-capped CuO nanoparticles.

    Science.gov (United States)

    Seehra, M.; Punnoose, A.; Mahamuni, S.

    2002-03-01

    Synthesis of CuO nanoparticles (NP) capped with TOAB (tetraoctylammonium bromide) and their structural properties were reported recently [1]. Here we report on the magnetic properties of the TOAB-capped CuO-NP of size 4, 6 and 10 nm and compare these properties with those of uncapped CuO-NP in the size range of 6.6-37 nm described in the above abstract [2] and in a recent publication [3]. Temperature (5 K 350 K) and magnetic field (up to 55 kOe) variations of magnetization M, coercivity H_c, exchange bias He (field-cooled in 55 kOe) and the Neel temperature TN (where He goes to zero) were measured. The TOAB-capped NP have higher magnitudes of Ms (the weak ferromagnetic component of M) and lower He values, confirming the 1/Ms variation of He observed in uncapped CuO-NP for size Magnone, Seehra & Bonevich, Phys. Rev. B64, 174420 (2001).

  16. The thermospheric effects of a rapid polar cap expansion

    Directory of Open Access Journals (Sweden)

    D. W. Idenden

    1998-10-01

    Full Text Available In a previous publication we used results from a coupled thermosphere-ionosphere-plasmasphere model to illustrate a new mechanism for the formation of a large-scale patch of ionisation arising from a rapid polar cap expansion. Here we describe the thermospheric response to that polar cap expansion, and to the ionospheric structure produced. The response is dominated by the energy and momentum input at the dayside throat during the expansion phase itself. These inputs give rise to a large-scale travelling atmospheric disturbance (TAD that propagates both antisunward across the polar cap and equatorward at speeds much greater than both the ion drifts and the neutral winds. We concentrate only on the initially poleward travelling disturbance. The disturbance is manifested in the neutral temperature and wind fields, the height of the pressure level surfaces and in the neutral density at fixed heights. The thermospheric effects caused by the ionospheric structure produced during the expansion are hard to discern due to the dominating effects of the TAD.Key words. Ionosphere (ionosphere · atmosphere interaction; modeling and forecasting; plasma convection.

  17. Alternative splicing variations in mouse CAPS2: differential expression and functional properties of splicing variants

    Directory of Open Access Journals (Sweden)

    Furuichi Teiichi

    2007-04-01

    Full Text Available Abstract Background Ca2+-dependent activator protein 2 (CAPS2/CADPS2 is a secretory vesicle-associated protein involved in the release of neurotrophin. We recently reported that an aberrant, alternatively spliced CAPS2 mRNA that lacks exon 3 (CAPS2Δexon3 is detected in some patients with autism. Splicing variations in mouse CAPS2 and their expression and functions remain unclear. Results In this study, we defined 31 exons in the mouse CAPS2 gene and identified six alternative splicing variants, CAPS2a-f. CAPS2a is an isoform lacking exons 22 and 25, which encode part of the Munc13-1-homologous domain (MHD. CAPS2b lacks exon 25. CAPS2c lacks exons 11 and 22. CAPS2d, 2e, and 2f have C-terminal deletions from exon 14, exon 12, and exon 5, respectively. On the other hand, a mouse counterpart of CAPS2Δexon3 was not detected in the mouse tissues tested. CAPS2b was expressed exclusively in the brain, and the other isoforms were highly expressed in the brain, but also in some non-neural tissues. In the brain, all isoforms showed predominant expression patterns in the cerebellum. In the developing cerebellum, CAPS2b showed an up-regulated expression pattern, whereas the other isoforms exhibited transiently peaked expression patterns. CAPS2 proteins were mostly recovered in soluble fractions, but some were present in membrane fractions, except for CAPS2c and 2f, both of which lack the PH domain, suggesting that the PH domain is important for membrane association. In contrast to CAPS2a and 2b, CAPS2c showed slightly decreased BDNF-releasing activity, which is likely due to the C-terminal truncation of the PH domain in CAPS2c. Conclusion This study indicates that, in mouse, there are six splicing variants of CAPS2 (CAPS2a-f, and that these are subdivided into two groups: a long form containing the C-terminal MHD and a short form lacking the C-terminal MHD. These results demonstrate that the splicing variations correlate with their expression patterns and

  18. Dynamic Interaction between Cap & Trade and Electricity Markets

    Science.gov (United States)

    Jeev, Kumar

    Greenhouse Gases (GHG), such as Carbon-Dioxide (CO2), which is released in the atmosphere due to anthropogenic activities like power production, are now accepted as the main culprits for global warming. The Regional Greenhouse Gas Initiative (RGGI), an initiative of the North East and Mid-Atlantic States of the United States (US) for limiting the emission of GHG, has developed a regional cap-and-trade program for CO2 emissions for power plants. Existing cap-and-trade programs in US and Europe for Greenhouse Gases have recently been plagued by over-allocation. Carbon prices recently collapsed in all these markets during the global recession. Since then, there have been significant policy changes, which have resulted in the adoption of aggressive emission cap targets by most major carbon emission markets. This is expected to make carbon emissions availability more restrictive, raising the prices of these credits. These emissions markets are expected to have a major impact on the wholesale electricity markets. Two models to study the interaction of these two markets are presented. These models assess the impact of the emissions market on wholesale electricity prices. The first model characterizes the competition between two types of power plants (coal and gas) in both the electricity and emissions markets as a dynamic game using the Cournot approximation. Under this approximation, we find that in the Nash equilibrium the plants increase their permit allocation to high-demand periods and the marginal value of each credit for a plant is identical in all periods under their optimal equilibrium strategy. The second numerical model allows us to explicitly evaluate the closed loop equilibrium of the dynamic interaction of two competitors in these markets. We find that plants often try to corner the market and push prices all the way to the price cap. Power plants derive most of their profits from these extreme price regimes. In the experiments where trading is allowed

  19. Qualification Approach for the CMC Nose Cap of X-38

    Science.gov (United States)

    Weihs, H.; Gülhan, A.

    2002-01-01

    In October 2001 the flight hardware of the TPS nose assembly of X-38 has been installed at the main structure of the X-38 V201 vehicle at NASA's Johnson Space Center, Houston Texas. X-38 is a test vehicle for the planned Crew Return Vehicle CRV for the International Space Station ISS. Currently the flight of the X-38 is scheduled for 2005. Besides the Body flaps (MAN-T) and the nose skirt system (ASTRIUM, MAN-T) the nose cap system is one of the essential hot structure components that were developed within Germany's national TETRA (Technologies for future space transportation systems) programme. The integration of the hardware was an important milestone for the nose cap development which started approx. 5 years ago. DLR-Stuttgart is responsible for the design and manufacturing of the CMC based nose cap system, which has to withstand the extreme thermal loads during re-entry which will induce a maximum temperature up to 1750 °C on the surface of the cap. Thus, the shell of the cap system is designed and manufactured using DLR's C/C-SiC material which is a special kind of carbon based ceramic matrix composite (CMC) material produced via the in house liquid silicon infiltration process of DLR. This material has demonstrated its good temperature resistance during FOTON and EXPRESS re-entry capsule missions. Besides the design and manufacturing of the nose cap system, the qualification approach was an important effort of the development work. Missing a test facility which is able to simulate all loading conditions from lift off to re-entry and landing, is was necessary to separate the loads and to use different test facilities. Considering the limitations of the facilities, the budget and time constraints, an optimized test philosophy has been established. The goal was to use a full scale qualification unit including all TPS components of the nose area for most of the tests. These were the simulation of ascent loads given by the shuttle requirements and descent loads

  20. Evaluation of MerCAP for Power Plant Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    Carl Richardson

    2008-09-30

    This report is submitted to the U.S. Department of Energy National Energy Technology Laboratory (DOE-NETL) as part of Cooperative Agreement DE-FC26-03NT41993, 'Evaluation of EPRI's MerCAP{trademark} Technology for Power Plant Mercury Control'. This project has investigated the mercury removal performance of EPRI's Mercury Capture by Amalgamation Process (MerCAP{trademark}) technology. Test programs were conducted to evaluate gold-based MerCAP{trademark} at Great River Energy's Stanton Station Unit 10 (Site 1), which fired both North Dakota lignite (NDL) and Power River Basin (PRB) coal during the testing period, and at Georgia Power's Plant Yates Unit 1 (Site 2) [Georgia Power is a subsidiary of The Southern Company] which fires a low sulfur Eastern bituminous coal. Additional tests were carried out at Alabama Power's Plant Miller, which fires Powder River Basin Coal, to evaluate a carbon-based MerCAP{trademark} process for removing mercury from flue gas downstream of an electrostatic precipitator [Alabama Power is a subsidiary of The Southern Company]. A full-scale gold-based sorbent array was installed in the clean-air plenum of a single baghouse compartment at GRE's Stanton Station Unit 10, thereby treating 1/10th of the unit's exhaust gas flow. The substrates that were installed were electroplated gold screens oriented parallel to the flue gas flow. The sorbent array was initially installed in late August of 2004, operating continuously until its removal in July 2006, after nearly 23 months. The initial 4 months of operation were conducted while the host unit was burning North Dakota lignite (NDL). In November 2004, the host unit switched fuel to burn Powder River Basin (PRB) subbituminous coal and continued to burn the PRB fuel for the final 19 months of this program. Tests were conducted at Site 1 to evaluate the impacts of flue gas flow rate, sorbent plate spacing, sorbent pre-cleaning and regeneration, and spray

  1. Estuarine-scale genetic variation in the polychaete hobsonia Florida (ampharetidae; annelida) in long island sound and relationships to pleistocene glaciations.

    Science.gov (United States)

    Olson, Mary Ann; Zajac, Roman N; Russello, Michael A

    2009-08-01

    Modern patterns of genetic variation in northern estuarine species are likely shaped by both historical and contemporary processes. Many studies have demonstrated the predominant roles of Pleistocene glaciations, life-history traits, or a combination of both in shaping patterns of population differentiation across a broad range of animal species, yet comparatively few have investigated such questions in benthic invertebrates. We examined fine-scale patterns of genetic differentiation among populations in the ampharetid polychaete Hobsonia florida in Long Island Sound (LIS) relative to its life-history traits and the geologic history of the region. Mitochondrial DNA sequencing of cytochrome oxidase I (COI) revealed 15 unique haplotypes among four populations in LIS and two outgroups. Populations in LIS exhibited the greatest haplotypic diversity compared to outgroup populations. Analysis of molecular variance revealed a highly significant level of genetic heterogeneity (P mixing, further mediated by low dispersal and specialized habitat requirements.

  2. Enhanced δ13C and δ18O Differences Between the South Atlantic and South Pacific During the Last Glaciation: The Deep Gateway Hypothesis

    Science.gov (United States)

    Sikes, Elisabeth L.; Allen, Katherine A.; Lund, David C.

    2017-10-01

    Enhanced vertical gradients in benthic foraminiferal δ13C and δ18O in the Atlantic and Pacific during the last glaciation have revealed that ocean overturning circulation was characterized by shoaling of North Atlantic sourced interior waters; nonetheless, our understanding of the specific mechanisms driving these glacial isotope patterns remains incomplete. Here we compare high-resolution depth transects of Cibicidoides spp. δ13C and δ18O from the Southwest Pacific and the Southwest Atlantic to examine relative changes in northern and southern sourced deep waters during the Last Glacial Maximum (LGM) and deglaciation. During the LGM, our transects show that water mass properties and boundaries in the South Atlantic and Pacific were different from one another. The Atlantic between 1.0 and 2.5 km was more than 1‰ enriched in δ13C relative to the Pacific and remained more enriched through the deglaciation. During the LGM, Atlantic δ18O was 0.5‰ more enriched than the Pacific, particularly below 2.5 km. This compositional difference between the deep portions of the basins implies independent deep water sources during the glaciation. We attribute these changes to a "deep gateway" effect whereby northern sourced waters shallower than the Drake Passage sill were unable to flow southward into the Southern Ocean because a net meridional geostrophic transport cannot be supported in the absence of a net east-west circumpolar pressure gradient above the sill depth. We surmise that through the LGM and early deglaciation, shoaled northern sourced waters were unable to escape the Atlantic and contribute to deep water formation in the Southern Ocean.

  3. The MIS 3 maximum of the Torres del Paine and Última Esperanza ice lobes in Patagonia and the pacing of southern mountain glaciation

    Science.gov (United States)

    García, Juan-Luis; Hein, Andrew S.; Binnie, Steven A.; Gómez, Gabriel A.; González, Mauricio A.; Dunai, Tibor J.

    2018-04-01

    The timing, structure and termination of the last southern mountain glaciation and its forcing remains unclear. Most studies have focused on the global Last Glacial Maximum (LGM; 26.5-19 ka) time period, which is just part of the extensive time-frame within the last glacial period, including Marine Isotope Stages 3 and 4. Understanding the glacial fluctuations throughout the glacial period is a prerequisite for uncovering the cause and climate mechanism driving southern glaciation and the interhemispheric linkages of climate change. Here, we present an extensive (n = 65) cosmogenic 10Be glacier chronology derived from moraine belts marking the pre-global LGM extent of the former Patagonian Ice Sheet in southernmost South America. Our results show the mountain ice sheet reached its maximum extent at 48.0 ± 1.8 ka during the local LGM, but attained just half this extent at 21.5 ± 1.8 ka during the global LGM. This finding, supported by nearby glacier chronologies, indicates that at orbital time scales, the southern mid-latitude glaciers fluctuated out-of-phase with northern hemisphere ice sheets. At millennial time-scales, our data suggest that Patagonian and New Zealand glaciers advanced in unison with cold Antarctic stadials and reductions in Southern Ocean sea surface temperatures. This implies a southern middle latitudes-wide millennial rhythm of climate change throughout the last glacial period linked to the north Atlantic by the bipolar seesaw. We suggest that winter insolation, acting alongside other drivers such as the strength and/or position of the southern westerlies, controlled the extents of major southern mountain glaciers such as those in southernmost South America.

  4. New age constraints for the Saalian glaciation in northern central Europe: Implications for the extent of ice sheets and related proglacial lake systems

    Science.gov (United States)

    Lang, Jörg; Lauer, Tobias; Winsemann, Jutta

    2018-01-01

    A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events.

  5. The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating

    Science.gov (United States)

    Johnson, Joanne S.; Smith, James A.; Schaefer, Joerg M.; Young, Nicolás E.; Goehring, Brent M.; Hillenbrand, Claus-Dieter; Lamp, Jennifer L.; Finkel, Robert C.; Gohl, Karsten

    2017-12-01

    Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and timing of ice cover. However, terrestrial records of ice sheet history from the region remain sparse, resulting in significant model uncertainties. We report glacial-geological evidence for the duration and timing of the last glaciation of Hunt Bluff, in the central Amundsen Sea Embayment. A multi-nuclide approach was used, measuring cosmogenic 10Be and in situ14C in bedrock surfaces and a perched erratic cobble. Bedrock 10Be ages (118-144 ka) reflect multiple periods of exposure and ice-cover, not continuous exposure since the last interglacial as had previously been hypothesized. In situ14C dating suggests that the last glaciation of Hunt Bluff did not start until 21.1 ± 5.8 ka - probably during the Last Glacial Maximum - and finished by 9.6 ± 0.9 ka, at the same time as ice sheet retreat from the continental shelf was complete. Thickening of ice at Hunt Bluff most likely post-dated the maximum extent of grounded ice on the outer continental shelf. Flow re-organisation provides a possible explanation for this, with the date for onset of ice-cover at Hunt Bluff providing a minimum age for the timing of convergence of the Dotson and Getz tributaries to form a single palaeo-ice stream. This is the first time that timing of onset of ice cover has been constrained in the Amundsen Sea Embayment.

  6. Preparation and characterization of Au nanoparticles capped with mercaptocarboranyl clusters.

    Science.gov (United States)

    Cioran, Ana M; Teixidor, Francesc; Krpetić, Željka; Brust, Mathias; Viñas, Clara

    2014-04-07

    The preparation of 3-4 nm and 10 nm gold nanoparticles capped with neutral carborane-based mercaptocarboranes, via two different preparative routes, is reported. The resulting boron-enriched nanomaterials exhibit complete dispersibility in water, opening the way for the use of these monolayer protected clusters (MPCs) in medical applications, such as boron neutron capture therapy (BNCT). These newly prepared MPCs have been characterized by FTIR, (1)H and (11)B NMR spectroscopy, UV-visible, centrifugal particle sizing (CPS), and, in some cases, inductively coupled plasma atomic emission spectrometry (ICP-AES). Water dispersibility exhibited by these MPCs allowed the study of the cellular uptake by HeLa cells.

  7. Computed tomography on a defective CANDU fuel pencil end cap

    International Nuclear Information System (INIS)

    Lupton, L.R.

    1985-09-01

    Five tomographic slices through a defective end cap from a CANDU fuel pencil have been generated using a Co-60 source and a first generation translate-rotate tomography scanner. An anomaly in the density distribution that is believed to have resulted from the defect has been observed. However, with the 0.30 mm spatial resolution used, it has not been possible to state unequivocally whether the change in density is caused by a defect in the weld or a statistical anomaly in the data. It is concluded that a microtomography system, with a spatial resolution in the range of 0.1 mm, could detect the flaw

  8. The structural effects of cap and trade climate policy

    International Nuclear Information System (INIS)

    Goettle, Richard J.; Fawcett, Allen A.

    2009-01-01

    The Inter-temporal General Equilibrium Model (IGEM) explores the cost to the U.S. economy of increasingly more stringent cap and trade regimes. The economy-wide losses are small with energy, agriculture, chemicals, high tech manufacturing and trade being most affected. The availability of lower cost offsets substantially reduces these economic losses. The economy becomes less capital but more labor intensive. Household welfare losses are smaller for full consumption (goods, services and leisure). A more inelastic trade-off between consumption and leisure dramatically reduces policy costs as do more favorable revenue recycling options. Induced technical change yields a small, measurable reduction in policy costs. (author)

  9. Metal-silicon reaction rates - The effects of capping

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.

    1989-01-01

    Evidence is presented showing that the presence of the commonly used anti-reflection coating material Ta2O5 on the free surface of contact metallization can either suppress or enhance, depending on the system, the interaction that takes place at elevated temperatures between the metallization and the underlying Si. The cap layer is shown to suppress both the generation and annihilation of vacancies at the free surface of the metal which are necessary to support metal-Si interactons. Evidence is also presented indicating that the mechanical condition of the free metal surface has a significant effect on the metal-silicon reaction rate.

  10. Production of the CMS Tracker End Cap sub-structures

    CERN Document Server

    Fontaine, Jean-Charles

    2007-01-01

    The production and qualification of the 288 petals needed to build both CMS Tracker End Caps (TECs) is summarized. There will be first a description of a petal, integrating many components, the most important ones being the silicon modules. The organization of the production, involving 7 Institutes all over Europe, will then be explained. The petal assembly and testing procedure will be quickly described. The quality assurance put in place at each production step has resulted in a very high petal quality, as some overall plots will attest. Finally some details about part failures will be given.

  11. Environmentally Sustainable Agriculture and Future Developments of the CAP

    DEFF Research Database (Denmark)

    Ørsted Nielsen, Helle; Branth Pedersen, Anders; Christensen, Tove

    2009-01-01

    in the world market could increase pressure to slacken regulatory requirements on agriculture. Thus, the question of whether liberalization will hinder or promote environmentally sustainable production methods in agriculture is unresolved. This paper analyses different scenarios of agricultural policy...... development and examines their consequences for the promotion of environmentally sustainable agriculture in the EU.......Recent reforms of the European Union’s Common Agricultural Policy (CAP) have set in motion a process of increased market orientation in the agricultural sector, a process that will be intensified by trade liberalization if an agreement is reached under the World Trade Organization (WTO...

  12. Effectiveness evaluation of three RCRA caps at the Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Shevenell, L.A. [Nevada Bureau of Mines and Geology, Reno, NV (United States); Goldstrand, P.M. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences

    1994-01-01

    Because installation of Resource Conservation and Recovery Act (RCRA)- engineered caps is costly, it is prudent to evaluate the effectiveness of this procedure for hydrologically isolating contaminants. The objective for installation of five-part engineered caps at the Y-12 Plant was to (1) satisfy the regulatory compliance issues, (2) minimize the risk of direct contact with the wastes, and (3) reduce rainfall infiltration. Although the original objectives of installing the caps were not to alter groundwater flow, a potential effect of reducing infiltration is to minimize leaching, thus retarding groundwater contaminant migration from the site. Hence, cap effectiveness with respect to reduced groundwater contaminant migration is evaluated using groundwater data in this report. Based on the available data at the Y-12 capped areas, evaluation of cap effectiveness includes studying water level and chemical variability in nearby monitoring wells. Three caps installed during 1989 are selected for evaluation in this report. These caps are located in three significantly different hydrogeologic settings: overlying a karst aquifer (Chestnut Ridge Security Pits [CRSP]), overlying shales located on a hill slope (Oil Landfarm Waste Management Area [OLWMA]), and overlying shales in a valley floor which is a site of convergent groundwater flow (New Hope Pond [NHP]). Presumably, the caps have been effective in minimizing risk of direct contact with the wastes and halting direct rainfall infiltration into the sites over the extent of the capped areas, but no evidence is presented in this report to directly demonstrate this. The caps installed over the three sites appear to have had a minimal effect on groundwater contaminant migration from the respective sites. Following cap construction, no changes in the configuration of the water table were observed. Migration of contaminant plumes occurred at all three sites, apparently without regard to the timing of cap installation.

  13. DNA-PKcs is critical for telomere capping

    Energy Technology Data Exchange (ETDEWEB)

    Gilley, David; Tanaka, Hiromi; Hande, M. Prakash; Kurimasa,Akihiro; Li, Gloria C.; Chen, David J.

    2001-04-10

    The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is critical for DNA repair via the non-homologous end joining (NHEJ) pathway. Previously, it was reported that bone marrow cells and spontaneously transformed fibroblasts from SCID (severe combined immunodeficiency) mice have defects in telomere maintenance. The genetically defective SCID mouse arose spontaneously from its parental strain CB17. One known genomic alteration in SCID mice is a truncation of the extreme carboxyl-terminus of DNA-PKcs, but other as yet unidentified alterations may also exist. We have used a defined system, the DNA-PKcs knockout mouse, to investigate specifically the role DNA-PKcs specifically plays in telomere maintenance. We report that primary mouse embryonic fibroblasts (MEFs) and primary cultured kidney cells from 6-8 month old DNA-PKcs deficient mice accumulate a large number of telomere fusions, yet still retain wildtype telomere length. Thus, the phenotype of this defect separates the two-telomere related phenotypes, capping and length maintenance. DNA-PKcs deficient MEFs also exhibit elevated levels of chromosome fragments and breaks, which correlate with increased telomere fusions. Based on the high levels of telomere fusions observed in DNA-PKcs deficient cells, we conclude that DNA-PKcs plays an important capping role at the mammalian telomere.

  14. Self-assembly of colloids with magnetic caps

    Energy Technology Data Exchange (ETDEWEB)

    Novak, E.V., E-mail: ekaterina.novak@urfu.ru [Ural Federal University, Lenin Av. 51, Ekaterinburg (Russian Federation); Kantorovich, S.S. [Ural Federal University, Lenin Av. 51, Ekaterinburg (Russian Federation); University of Vienna, Sensengasse 8, Vienna (Austria)

    2017-06-01

    In our earlier work (Steinbach et al., 2016 ) we investigated a homogeneous system of magnetically capped colloidal particles that self-assembled via two structural patterns of different symmetry. The particles could form a compact, equilateral triangle with a three-fold rotational symmetry and zero dipole moment and a staggered chain with mirror symmetry with a net magnetisation perpendicular to the chain. The system exhibited a bistability already in clusters of three particles. Based on observations of a real magnetic particles system, analytical calculations and molecular dynamics simulations, it has been shown that the bistability is a result of an anisotropic magnetisation distribution with rotational symmetry inside the particles. The present study is a logical extension of the above research and forms a preparatory stage for the study of a self-assembly of such magnetic particles under the influence of an external magnetic field. Since the magnetic field is only an additive contribution to the total ground state energy, we can study the interparticle interaction energies of candidate ground state structures based on the field-free terms. - Highlights: • Analytical calculations of the energies of ground state candidates for colloids with magnetic caps. • Computer simulations confirmed the theoretical model. • The structural transition between ground states was found.

  15. Trapping and release of citrate-capped gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Darwin R., E-mail: darwin.reyes@nist.gov [Semiconductor Electronics Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Mijares, Geraldine I.; Nablo, Brian [Semiconductor Electronics Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Briggman, Kimberly A. [Optical Technology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Gaitan, Michael [Semiconductor Electronics Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2011-08-01

    An electrical method to trap and release charged gold nanoparticles onto and from the surface of gold electrodes modified by an alkanethiol self-assembled monolayer (SAM) is presented. To form electrodes coated with gold nanoparticles (GNPs), amine-terminated SAMs on gold electrodes were immersed in a solution of negatively charged citrate-capped GNPs. Accumulation of GNPs on the electrode surface was monitored by a decrease in the impedance of the SAM-modified electrode and by an increase in the electrochemical activity at the electrode as shown through cyclic voltammetry (CV). Electrostatic interactions between the GNPs and the amine-terminated SAM trap the GNPs on the electrode surface. Application of a subsequent negative bias to the electrode initiated a partial release of the GNPs from the electrode surface. Impedance spectroscopy, cyclic voltammetry, ultraviolet-visible (UV-Vis) spectroscopy and atomic force microscopy (AFM) were used to monitor and confirm the attraction of GNPs to and release from the aminealkanethiolated gold electrodes. This work describes a method of trapping and release for citrate-capped GNPs that could be used for on-demand nanoparticle delivery applications such as in assessing and modeling nanoparticle toxicology, as well as for monitoring the functionalization of gold nanoparticles.

  16. Effects of intima stiffness and plaque morphology on peak cap stress

    Directory of Open Access Journals (Sweden)

    Virmani Renu

    2011-04-01

    Full Text Available Abstract Background Rupture of the cap of a vulnerable plaque present in a coronary vessel may cause myocardial infarction and death. Cap rupture occurs when the peak cap stress exceeds the cap strength. The mechanical stress within a cap depends on the plaque morphology and the material characteristics of the plaque components. A parametric study was conducted to assess the effect of intima stiffness and plaque morphology on peak cap stress. Methods Models with idealized geometries based on histology images of human coronary arteries were generated by varying geometric plaque features. The constructed multi-layer models contained adventitia, media, intima, and necrotic core sections. For adventitia and media layers, anisotropic hyperelastic material models were used. For necrotic core and intima sections, isotropic hyperelastic material models were employed. Three different intima stiffness values were used to cover the wide range reported in literature. According to the intima stiffness, the models were classified as stiff, intermediate and soft intima models. Finite element method was used to compute peak cap stress. Results The intima stiffness was an essential determinant of cap stresses. The computed peak cap stresses for the soft intima models were much lower than for stiff and intermediate intima models. Intima stiffness also affected the influence of morphological parameters on cap stresses. For the stiff and intermediate intima models, the cap thickness and necrotic core thickness were the most important determinants of cap stresses. The peak cap stress increased three-fold when the cap thickness was reduced from 0.25 mm to 0.05 mm for both stiff and intermediate intima models. Doubling the thickness of the necrotic core elevated the peak cap stress by 60% for the stiff intima models and by 90% for the intermediate intima models. Two-fold increase in the intima thickness behind the necrotic core reduced the peak cap stress by

  17. A Capping Step During Automated Glycan Assembly Enables Access to Complex Glycans in High Yield.

    Science.gov (United States)

    Yu, Yang; Kononov, Andrew; Delbianco, Martina; Seeberger, Peter H

    2018-04-20

    The products of multi-step automated solid phase syntheses are purified after release from the resin. Capping of unreacted nucleophiles is commonplace in automated oligonucleotide synthesis to minimize accumulation of deletion sequences. To date, capping was not used routinely during automated glycan assembly (AGA) since previous capping protocols suffered from long reaction times and conditions incompatible with some protective groups. Here, a method using methanesulfonic acid and acetic anhydride for the fast and quantitative capping of hydroxyl groups that failed to be glycosylated is reported. Commonly used protective groups in AGA are stable under these capping conditions. The introduction of a capping step into the coupling cycle drastically improved overall yields by decreasing side-products and simplifying purification, while reducing building block consumption. To illustrate the method, the biologically important tetrasaccharide Lc4, as well as a 50-mer polymannoside were prepared. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Organic–Inorganic Nanostructure Architecture via Directly Capping Fullerenes onto Quantum Dots

    Directory of Open Access Journals (Sweden)

    Kim Jonggi

    2011-01-01

    Full Text Available Abstract A new form of fullerene-capped CdSe nanoparticles (PCBA-capped CdSe NPs, using carboxylate ligands with [60]fullerene capping groups that provides an effective synthetic methodology to attach fullerenes noncovalently to CdSe, is presented for usage in nanotechnology and photoelectric fields. Interestingly, either the internal charge transfer or the energy transfer in the hybrid material contributes to photoluminescence (PL quenching of the CdSe moieties.

  19. Organic-Inorganic Nanostructure Architecture via Directly Capping Fullerenes onto Quantum Dots.

    Science.gov (United States)

    Lee, Jae Kwan; Kim, Jonggi; Yang, Changduk

    2011-12-01

    A new form of fullerene-capped CdSe nanoparticles (PCBA-capped CdSe NPs), using carboxylate ligands with [60]fullerene capping groups that provides an effective synthetic methodology to attach fullerenes noncovalently to CdSe, is presented for usage in nanotechnology and photoelectric fields. Interestingly, either the internal charge transfer or the energy transfer in the hybrid material contributes to photoluminescence (PL) quenching of the CdSe moieties.

  20. Student Loans: Oversight of Servicemembers Interest Rate Cap Could Be Strengthened

    Science.gov (United States)

    2016-11-01

    STUDENT LOANS Oversight of Servicemembers’ Interest Rate Cap Could Be Strengthened Report to Ranking Member...Governmental Affairs, U.S. Senate November 2016 STUDENT LOANS Oversight of Servicemembers’ Interest Rate Cap Could Be Strengthened Why GAO Did...This Study SCRA helps servicemembers financially by capping interest rates on student loans during active duty. As of May 2016, about 1.3 million

  1. In Vitro Comparison of Cytotoxicity and Genotoxicity of Three Vital Pulp Capping Materials

    OpenAIRE

    Zakerzadeh, Azadeh; Esnaashari, Ehsan; Dadfar, Sonia

    2017-01-01

    Introduction: Direct pulp capping (DPC) is a treatment for maintaining pulp vitality and its biological function. Ideally, pulp capping agents are expected to induce pulp cells to form hard tissue. This in vitro study assessed the cytotoxicity and genotoxicity of three vital pulp capping (VPC) agents naming Biodentine (Septodont, Saint-Maur-des-Fosses, France), mineral trioxide aggregate (ProRoot MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA) and TheraCal LC (Bisco Inc, Schamburg, IL, USA) on h...

  2. Comparative Politics of Sub-Federal Cap-and-Trade: Implementing the Western Climate Initiative

    OpenAIRE

    David Houle; Erick Lachapelle; Mark Purdon

    2015-01-01

    Why have only two of the eleven original members of the Western Climate Initiative implemented a cap-and-trade system? This article compares the implementation of cap-and-trade in California and Quebec versus in New Mexico and British Columbia. Ideas around the reality of anthropogenic global warming and the legitimacy of cap-and-trade created favorable context in three jurisdictions, although institutions condition the expression of these ideas in the policy-making process. Since parliamenta...

  3. Neutron transition multipole moment for /sup 88/Sr(. cap alpha. ,. cap alpha. ')/sup 88/Sr (2/sup +/, 1. 84 MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S.K.; Ray, S.; Majumdar, H.; Ghosh, S.K.; Samanta, C.; Dasgupta, P.; Chintalapudi, S.N.; Banerjee, S.R.

    1989-04-01

    The neutron transition multipole moment, M/sub n/, for (0/sup +/..-->..2/sup +/, 1.84 MeV) transition is inferred by measuring the (..cap alpha..,..cap alpha..') angular distribution at E/sub ..cap alpha../ = 50 MeV and comparing it with a microscopic distorted-wave Born approximation calculation. Proton transition densities are taken from electron scattering data. M/sub n//M/sub p/ is found to be substantially less than N/Z in agreement with the (p,p') result.

  4. The first Inner Detector End-Cap is lowered into the cavern

    CERN Multimedia

    Heinz Pernegger

    The first Inner Detector End-Cap, containing both the SCT and TRT detectors, arriving down the access shaft on the A-side. . The Inner Detector End-Cap A approaching the installation platform. During the difficult phase of inserting the Inner Detector into the cryostat. On Thursday, May 24, the first Inner Detector end-cap, with both the TRT and SCT end-caps, was taken down to the pit. More pictures can be found on the transfer from SR1 to SX1 as well as the lowering into the cavern and reception on the platform which can also be seen as a slide show

  5. Retention Strength of Conical Welding Caps for Fixed Implant-Supported Prostheses.

    Science.gov (United States)

    Nardi, Diego; Degidi, Marco; Sighinolfi, Gianluca; Tebbel, Florian; Marchetti, Claudio

    This study evaluated the retention strength of welding caps for Ankylos standard abutments using a pull-out test. Each sample consisted of an implant abutment and its welding cap. The tests were performed with a Zwick Roell testing machine with a 1-kN load cell. The retention strength of the welding caps increased with higher abutment diameters and higher head heights and was comparable or superior to the values reported in the literature for the temporary cements used in implant dentistry. Welding caps provide a reliable connection between an abutment and a fixed prosthesis without the use of cement.

  6. A concept study of a carbon spar cap design for a 80m wind turbine blade

    International Nuclear Information System (INIS)

    Rosemeier, M; Bätge, M

    2014-01-01

    The buckling resistance is a key design driver for large wind turbine blades with a significant influence on the material costs. During the structural design process the choice was made for carbon spar caps and two shear webs, which were set relatively far apart in order to stabilize the panels. This design presented a major challenge for the stability of the spar caps. The topology of these spar caps has been modified with regard to stability, comparing a continuous spar cap with split spar cap concepts and considering both lay-ups with hybrid carbon glass spar caps or sandwich concepts. Within those concepts, parametric studies were conducted varying different geometrical parameters of the spar caps and its layups. In order to determine the buckling resistance of the spar cap, an analytical model considering a 2D cross section discretized blade model was utilized to select the basic concept, after which a 3D numerical finite element model taking the whole blade into account was used to evaluate the chosen design concepts. The stability limit state analysis was conducted according to the certification scheme of GL guideline 2012. The various concepts were evaluated based on the blade's mass, tip deflection and modal properties. The results of this design process of the spar caps and the evaluation of the used analysis tools are presented within the paper

  7. Reception Test of Petals for the End Cap TEC+ of the CMS Silicon Strip Tracker

    CERN Document Server

    Bremer, R; Klein, Katja; Schmitz, Stefan Antonius; Adler, Volker; Adolphi, Roman; Ageron, Michel; Agram, Jean-Laurent; Atz, Bernd; Barvich, Tobias; Baulieu, Guillaume; Beaumont, Willem; Beissel, Franz; Bergauer, Thomas; Berst, Jean-Daniel; Blüm, Peter; Bock, E; Bogelsbacher, F; de Boer, Wim; Bonnet, Jean-Luc; Bonnevaux, Alain; Boudoul, Gaelle; Bouhali, Othmane; Braunschweig, Wolfgang; Brom, Jean-Marie; Butz, Erik; Chabanat, Eric; Chabert, Eric Christian; Clerbaux, Barbara; Contardo, Didier; De Callatay, Bernard; Dehm, Philip; Delaere, Christophe; Della Negra, Rodolphe; Dewulf, Jean-Paul; D'Hondt, Jorgen; Didierjean, Francois; Dierlamm, Alexander; Dirkes, Guido; Dragicevic, Marko; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Esser, Hans; Estre, Nicolas; Fahrer, Manuel; Fernández, J; Florins, Benoit; Flossdorf, Alexander; Flucke, Gero; Flügge, Günter; Fontaine, Jean-Charles; Freudenreich, Klaus; Frey, Martin; Friedl, Markus; Furgeri, Alexander; Giraud, Noël; Goerlach, Ulrich; Goorens, Robert; Graehling, Philippe; Grégoire, Ghislain; Gregoriev, E; Gross, Laurent; Hansel, S; Haroutunian, Roger; Hartmann, Frank; Heier, Stefan; Hermanns, Thomas; Heydhausen, Dirk; Heyninck, Jan; Hosselet, J; Hrubec, Josef; Jahn, Dieter; Juillot, Pierre; Kaminski, Jochen; Karpinski, Waclaw; Kaussen, Gordon; Keutgen, Thomas; Klanner, Robert; König, Stefan; Kosbow, M; Krammer, Manfred; Ledermann, Bernhard; Lemaître, Vincent; De Lentdecker, Gilles; Linn, Alexander; Lounis, Abdenour; Lübelsmeyer, Klaus; Lumb, Nicholas; Maazouzi, Chaker; Mahmoud, Tariq; Michotte, Daniel; Militaru, Otilia; Mirabito, Laurent; Müller, Thomas; Neukermans, Lionel; Ollivetto, C; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pein, Uwe; Pernicka, Manfred; Perriès, Stephane; Piaseki, C; Pierschel, Gerhard; Piotrzkowski, Krzysztof; Poettgens, Michael; Pooth, Oliver; Rouby, Xavier; Sabellek, Andreas; Schael, Stefan; Schirm, Norbert; Schleper, Peter; Schultz von Dratzig, Arndt; Siedling, Rolf; Simonis, Hans-Jürgen; Stahl, Achim; Steck, Pia; Steinbruck, G; Stoye, Markus; Strub, Roger; Tavernier, Stefaan; Teyssier, Daniel; Theel, Andreas; Trocmé, Benjamin; Udo, Fred; Van der Donckt, M; Van der Velde, C; Van Hove, Pierre; Vanlaer, Pascal; Van Lancker, Luc; Van Staa, Rolf; Vanzetto, Sylvain; Weber, Markus; Weiler, Thomas; Weseler, Siegfried; Wickens, John; Wittmer, Bruno; Wlochal, Michael; De Wolf, Eddi A; Zhukov, Valery; Zoeller, Marc Henning

    2009-01-01

    The silicon strip tracker of the CMS experiment has been completed and was inserted into the CMS detector in late 2007. The largest sub system of the tracker are its end caps, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted onto the TEC support structures. Each end cap consists of 144 such petals, which were built and fully qualified by several institutes across Europe. From

  8. Polar cap hot patches: Enhanced density structures different from the classical patches in the ionosphere

    Science.gov (United States)

    Zhang, Q.-H.; Ma, Y.-Z.; Jayachandran, P. T.; Moen, J.; Lockwood, M.; Zhang, Y.-L.; Foster, J. C.; Zhang, S.-R.; Wang, Y.; Themens, D. R.; Zhang, B.-C.; Xing, Z. Y.

    2017-08-01

    Based on in situ and ground-based observations, a new type of "polar cap hot patch" has been identified that is different from the classical polar cap enhanced density structure (cold patches). Comparing with the classical polar cap patches, which are transported from the dayside sunlit region with dense and cold plasma, the polar cap hot patches are associated with particle precipitations (therefore field-aligned currents), ion upflows, and flow shears. The hot patches may have the same order of density enhancement as classical patches in the topside ionosphere, suggesting that the hot patches may be produced by transported photoionization plasma into flow channels. Within the flow channels, the hot patches have low-energy particle precipitation and/or ion upflows associated with field-aligned currents and flow shears. Corresponding Global Navigation Satellite System (GNSS) signal scintillation measurements indicate that hot patches may produce slightly stronger radio signal scintillation in the polar cap region than classical patches. A new type of polar cap patches, "polar cap hot patches," is identified to differentiate enhanced density structures from classical patches. Hot patches are associated with particle precipitations, ion upflows, field-aligned currents, and shear flows in the polar cap. Hot patches may lead to slightly stronger ionospheric scintillations of GNSS signals in the polar cap region than classical patches.

  9. Adenovirus DNA binding protein inhibits SrCap-activated CBP and CREB-mediated transcription

    International Nuclear Information System (INIS)

    Xu Xiequn; Tarakanova, Vera; Chrivia, John; Yaciuk, Peter

    2003-01-01

    The SNF2-related CBP activator protein (SrCap) is a potent activator of transcription mediated by CBP and CREB. We have previously demonstrated that the Adenovirus 2 DNA Binding Protein (DBP) binds to SrCap and inhibits the transcription mediated by the carboxyl-terminal region of SrCap (amino acids 1275-2971). We report here that DBP inhibits the ability of full-length SrCap (1-2971) to activate transcription mediated by Gal-CREB and Gal-CBP. In addition, DBP also inhibits the ability of SrCap to enhance Protein Kinase A (PKA) activated transcription of the enkaphalin promoter. DBP was found to dramatically inhibit transcription of a mammalian two-hybrid system that was dependent on the interaction of SrCap and CBP binding domains. We also found that DBP has no effect on transcription mediated by a transcriptional activator that is not related to SrCap, indicating that our reported transcriptional inhibition is specific for SrCap and not due to nonspecific effects of DBP's DNA binding activity on the CAT reporter plasmid. Taken together, these results suggest a model in which DBP inhibits cellular transcription mediated by the interaction between SrCap and CBP

  10. A concept study of a carbon spar cap design for a 80m wind turbine blade

    Science.gov (United States)

    Rosemeier, M.; Bätge, M.

    2014-06-01

    The buckling resistance is a key design driver for large wind turbine blades with a significant influence on the material costs. During the structural design process the choice was made for carbon spar caps and two shear webs, which were set relatively far apart in order to stabilize the panels. This design presented a major challenge for the stability of the spar caps. The topology of these spar caps has been modified with regard to stability, comparing a continuous spar cap with split spar cap concepts and considering both lay-ups with hybrid carbon glass spar caps or sandwich concepts. Within those concepts, parametric studies were conducted varying different geometrical parameters of the spar caps and its layups. In order to determine the buckling resistance of the spar cap, an analytical model considering a 2D cross section discretized blade model was utilized to select the basic concept, after which a 3D numerical finite element model taking the whole blade into account was used to evaluate the chosen design concepts. The stability limit state analysis was conducted according to the certification scheme of GL guideline 2012. The various concepts were evaluated based on the blade's mass, tip deflection and modal properties. The results of this design process of the spar caps and the evaluation of the used analysis tools are presented within the paper.

  11. The ATLAS semiconductor tracker end-cap module

    Science.gov (United States)

    Abdesselam, A.; Adkin, P. J.; Allport, P. P.; Alonso, J.; Andricek, L.; Anghinolfi, F.; Antonov, A. A.; Apsimon, R. J.; Atkinson, T.; Batchelor, L. E.; Bates, R. L.; Beck, G.; Becker, H.; Bell, P.; Bell, W.; Beneš, P.; Bernabeu, J.; Bethke, S.; Bizzell, J. P.; Blocki, J.; Broklová, Z.; Brož, J.; Bohm, J.; Booker, P.; Bright, G.; Brodbeck, T. J.; Bruckman, P.; Buttar, C. M.; Butterworth, J. M.; Campabadal, F.; Campbell, D.; Carpentieri, C.; Carroll, J. L.; Carter, A. A.; Carter, J. R.; Casse, G. L.; Čermák, P.; Chamizo, M.; Charlton, D. G.; Cheplakov, A.; Chesi, E.; Chilingarov, A.; Chouridou, S.; Chren, D.; Christinet, A.; Chu, M. L.; Cindro, V.; Ciocio, A.; Civera, J. V.; Clark, A.; Colijn, A. P.; Cooke, P. A.; Costa, M. J.; Costanzo, D.; Dabrowski, W.; Danielsen, K. M.; Davies, V. R.; Dawson, I.; de Jong, P.; Dervan, P.; Doherty, F.; Doležal, Z.; Donega, M.; D'Onofrio, M.; Dorholt, O.; Drásal, Z.; Dowell, J. D.; Duerdoth, I. P.; Duxfield, R.; Dwuznik, M.; Easton, J. M.; Eckert, S.; Eklund, L.; Escobar, C.; Fadeyev, V.; Fasching, D.; Feld, L.; Ferguson, D. P. S.; Ferrari, P.; Ferrere, D.; Fleta, C.; Fortin, R.; Foster, J. M.; Fowler, C.; Fox, H.; Freestone, J.; French, R. S.; Fuster, J.; Gadomski, S.; Gallop, B. J.; García, C.; García-Navarro, J. E.; Gibson, S.; Gilchriese, M. G. D.; Gonzalez, F.; Gonzalez-Sevilla, S.; Goodrick, M. J.; Gorisek, A.; Gornicki, E.; Greenall, A.; Greenfield, D.; Gregory, S.; Grigorieva, I. G.; Grillo, A. A.; Grosse-Knetter, J.; Gryska, C.; Guipet, A.; Haber, C.; Hara, K.; Hartjes, F. G.; Hauff, D.; Haywood, S. J.; Hegeman, S. J.; Heinzinger, K.; Hessey, N. P.; Heusch, C.; Hicheur, A.; Hill, J. C.; Hodgkinson, M.; Hodgson, P.; Horažďovský, T.; Hollins, T. I.; Hou, L. S.; Hou, S.; Hughes, G.; Huse, T.; Ibbotson, M.; Iglesias, M.; Ikegami, Y.; Ilyashenko, I.; Issever, C.; Jackson, J. N.; Jakobs, K.; Jared, R. C.; Jarron, P.; Johansson, P.; Jones, R. W. L.; Jones, T. J.; Joos, D.; Joseph, J.; Jovanovic, P.; Jusko, O.; Jusko, V.; Kaplon, J.; Kazi, S.; Ketterer, Ch.; Kholodenko, A. G.; King, B. T.; Kodyš, P.; Koffeman, E.; Kohout, Z.; Kohriki, T.; Kondo, T.; Koperny, S.; Koukol, H.; Král, V.; Kramberger, G.; Kubík, P.; Kudlaty, J.; Lacasta, C.; Lagouri, T.; Lee, S. C.; Leney, K.; Lenz, S.; Lester, C. G.; Liebicher, K.; Limper, M.; Lindsay, S.; Linhart, V.; LLosá, G.; Loebinger, F. K.; Lozano, M.; Ludwig, I.; Ludwig, J.; Lutz, G.; Lys, J.; Maassen, M.; Macina, D.; Macpherson, A.; MacWaters, C.; Magrath, C. A.; Malecki, P.; Mandić, I.; Mangin-Brinet, M.; Martí-García, S.; Matheson, J. P.; Matson, R. M.; McMahon, S. J.; McMahon, T. J.; Meinhardt, J.; Mellado, B.; Melone, J. J.; Mercer, I. J.; Messmer, I.; Mikulec, B.; Mikuž, M.; Miñano, M.; Mitsou, V. A.; Modesto, P.; Moed, S.; Mohn, B.; Moncrieff, S.; Moorhead, G.; Morris, F. S.; Morris, J.; Morrissey, M.; Moser, H. G.; Moszczynski, A.; Muijs, A. J. M.; Murray, W. J.; Muskett, D.; Nacher, J.; Nagai, K.; Nakano, I.; Nickerson, R. B.; Nisius, R.; Oye, O. K.; O'Shea, V.; Paganis, E.; Parker, M. A.; Parzefall, U.; Pater, J. R.; Peeters, S. J. M.; Pellegrini, G.; Pelleriti, G.; Pernegger, H.; Perrin, E.; Phillips, P. W.; Pilavova, L. V.; Poltorak, K.; Pospíšil, S.; Postranecky, M.; Pritchard, T.; Prokofiev, K.; Rafí, J. M.; Raine, C.; Ratoff, P. N.; Řezníček, P.; Riadovikov, V. N.; Richter, R. H.; Robichaud-Véronneau, A.; Robinson, D.; Rodriguez-Oliete, R.; Roe, S.; Rudge, A.; Runge, K.; Saavedra, A.; Sadrozinski, H. F. W.; Sanchez, F. J.; Sandaker, H.; Saxon, D. H.; Scheirich, D.; Schieck, J.; Seiden, A.; Sfyrla, A.; Slavíček, T.; Smith, K. M.; Smith, N. A.; Snow, S. W.; Solar, M.; Sopko, B.; Sopko, V.; Sospedra, L.; Spencer, E.; Stanecka, E.; Stapnes, S.; Stastny, J.; Strachko, V.; Stradling, A.; Stugu, B.; Su, D. S.; Sutcliffe, P.; Szczygiel, R.; Tanaka, R.; Taylor, G.; Teng, P. K.; Terada, S.; Thompson, R. J.; Titov, M.; Toczek, B.; Tovey, D. R.; Tratzl, G.; Troitsky, V. L.; Tseng, J.; Turala, M.; Turner, P. R.; Tyndel, M.; Ullán, M.; Unno, Y.; Vickey, T.; Van der Kraaij, E.; Viehhauser, G.; Villani, E. G.; Vitek, T.; Vu Anh, T.; Vorobiev, A. P.; Vossebeld, J. H.; Wachler, M.; Wallny, R.; Ward, C. P.; Warren, M. R. M.; Webel, M.; Weber, M.; Weber, M.; Weidberg, A. R.; Weilhammer, P.; Wells, P. S.; Wetzel, P.; Whitley, M.; Wiesmann, M.; Wilhelm, I.; Willenbrock, M.; Wilmut, I.; Wilson, J. A.; Winton, J.; Wolter, M.; Wormald, M. P.; Wu, S. L.; Wu, X.; Zhu, H.; Bingefors, N.; Brenner, R.; Ekelof, T.

    2007-06-01

    The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip 3.3 μs buffer. The highest anticipated dose after 10 years operation is 1.4×1014 cm-2 in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area ˜70 cm2, each having 2×768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e- equivalent noise charge (ENC) rising to only 1800e- ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide flex read-out circuit and the ABCD3TA read-out ASICs. Finally, the accuracy of module assembly must not compromise the 16 μm (rφ) resolution perpendicular to the strip directions or 580 μm radial resolution coming from the 40 mrad front-back stereo angle. A total of 2210 modules were built to the tight tolerances and specifications required for the SCT. This was 234 more than the 1976 required and represents a yield of 93%. The component flow was at times tight, but the module production rate of 40-50 per week was maintained despite this. The distributed production was not found to be a major logistical problem and it allowed additional flexibility to take advantage of where the effort was available, including any spare capacity, for building the end-cap modules. The collaboration that produced the ATLAS SCT end-cap modules kept in close contact at all times so that the effects of shortages or stoppages at different sites could be

  12. Alternate Reductant Cold Cap Evaluation Furnace Phase II Testing

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Stone, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-09-03

    Savannah River Remediation (SRR) conducted a Systems Engineering Evaluation (SEE) to determine the optimum alternate reductant flowsheet for the Defense Waste Processing Facility (DWPF). Specifically, two proposed flowsheets (nitric–formic–glycolic and nitric–formic–sugar) were evaluated based upon results from preliminary testing. Comparison of the two flowsheets among evaluation criteria indicated a preference towards the nitric–formic–glycolic flowsheet. Further research and development of this flowsheet eliminated the formic acid, and as a result, the nitric–glycolic flowsheet was recommended for further testing. Based on the development of a roadmap for the nitric–glycolic acid flowsheet, Waste Solidification Engineering (WS-E) issued a Technical Task Request (TTR) to address flammability issues that may impact the implementation of this flowsheet. Melter testing was requested in order to define the DWPF flammability envelope for the nitric-glycolic acid flowsheet. The Savannah River National Laboratory (SRNL) Cold Cap Evaluation Furnace (CEF), a 1/12th scale DWPF melter, was selected by the SRR Alternate Reductant project team as the melter platform for this testing. The overall scope was divided into the following sub-tasks as discussed in the Task Technical and Quality Assurance Plan (TTQAP): Phase I - A nitric–formic acid flowsheet melter test (unbubbled) to baseline the CEF cold cap and vapor space data to the benchmark melter flammability models; Phase II - A nitric–glycolic acid flowsheet melter test (unbubbled and bubbled) to: Define new cold cap reactions and global kinetic parameters in support of the melter flammability model development; Quantify off-gas surging potential of the feed; Characterize off-gas condensate for complete organic and inorganic carbon species. After charging the CEF with cullet from Phase I CEF testing, the melter was slurry-fed with glycolic flowsheet based SB6-Frit 418 melter feed at 36% waste

  13. Terrace styles and timing of terrace formation in the Weser and Leine valleys, northern Germany: Response of a fluvial system to climate change and glaciation

    Science.gov (United States)

    Winsemann, Jutta; Lang, Jörg; Roskosch, Julia; Polom, Ulrich; Böhner, Utz; Brandes, Christian; Glotzbach, Christoph; Frechen, Manfred

    2015-09-01

    In glaciated continental basins accommodation space is not only controlled by tectonics and sea-level but also by the position of ice-sheets, which may act as a regional base-level for fluvial systems. Although the Pleistocene terrace record of major river systems in northwestern Europe has been investigated by many authors, relatively little attention has been paid to base-level changes related to glacier advance-retreat cycles and how these regional changes in base-level interacted with river catchment processes. This study provides a synthesis of the stratigraphic architecture of Middle Pleistocene to Holocene fluvial terraces in the upper Weser and middle Leine valley in northern Germany and links it to glaciation, climate and base-level change. The depositional architecture of the fluvial terrace deposits has been reconstructed from outcrops and high-resolution shear wave seismic profiles. The chronology is based on luminescence ages, 230Th/U ages, 14C ages and Middle Palaeolithic archaeological assemblages. The drainage system of the study area developed during the Early Miocene. During the Pleistocene up to 170 m of fluvial incision took place. A major change in terrace style from strath terraces to cut-and-fill terraces occurred during the early Middle Pleistocene before Marine Isotope Stage MIS 12, which may correlate with climate deterioration and the onset of glaciation in northern central Europe. During this time a stable buffer zone was established within which channels avulsed and cut and filled freely without leaving these vertical confines. Climate was the dominant driver for river incision and aggradation, whereas the terrace style was controlled by base-level changes during ice-sheet growth and decay. A major effect of glacio-isostatic processes was the post-Elsterian re-direction of the River Weser and River Leine. The Middle Pleistocene fluvial terraces are vertically stacked, indicating a high aggradation to degradation ratio, corresponding

  14. Finite single wall capped carbon nanotubes under hydrostatic pressure

    International Nuclear Information System (INIS)

    Baltazar, S E; Romero, A H; RodrIguez-Lopez, J L; Martonak, R

    2006-01-01

    We report a classical molecular dynamics isothermal-isobaric ensemble (NPT) implementation for the simulation of pressure effects on finite systems. The method is based on calculating the enclosed surface area by means of the Delauney triangulation method, which results in a fairly accurate description of the surface and the system volume. The external pressure is applied to the system by external forces acting on the triangulated surface covering the nanostructure. Pressure is exerted perpendicularly to every one of the Delauney triangles, by equally distributing the force to every corner of a triangle. We applied the method to finite single wall capped carbon nanotubes (SWCNTs) with different chiralities and different tube lengths ranging from 4 nm up to 30 nm. Pressure effects are studied as a function of the radii and the nanotube length, as well as as a function of temperature. Our results are in very good agreement when compared with both experimental and other theoretical results

  15. Synthesis and characterization of myristic acid capped silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, P. K., E-mail: pkkhanna@cmet.gov.in; Kulkarni, Deepti; Beri, Rupinder K. [Nanoscience Group, Centre for Materials for Electronics Technology (C-MET) (India)

    2008-08-15

    Reduction of silver myristate (AgMy) under mild thermal reaction conditions in a dipolar aprotic solvent i.e. N, N-dimethylformamide (DMF) has been carried out. UV-visible absorption measurements of dried and re-dispersible brown flocculants showed broad features of surface plasmon resonance (SPR) due to silver nanoparticles. The freshly isolated particles showed absorption bands at 414 and 485 nm, respectively, due to inter-particle coupling or clustering of silver ions and silver atoms. X-ray diffraction (XRD) pattern of fcc zero-valent silver resulted in crystallite size of about 10 nm. Scanning electron microscopy (SEM) revealed formation of rod shaped silver with increasing reaction temperature. Thermal analysis (TGA) showed about 10% weight loss due to organic capping.

  16. Synthesis of Stabilized Myrrh-Capped Hydrocolloidal Magnetite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2014-07-01

    Full Text Available Herein we report a new method for synthesizing stabilized magnetic nanoparticle (MNP colloids. A new class of monodisperse water-soluble magnetite nano-particles was prepared by a simple and inexpensive co-precipitation method. Iron ions and iodine were prepared by the reaction between ferric chloride and potassium iodide. The ferrous and ferric ions were hydrolyzed at low temperature at pH 9 in the presence of iodine to produce iron oxide nanoparticles. The natural product myrrh gum was used as capping agent to produce highly dispersed coated magnetite nanoparticles. The structure and morphology of the magnetic nanogel was characterized by Fourier transform infrared spectroscopy (FTIR and transmission electron microscopy (TEM, and X-ray diffraction (XRD was used to examine the crystal structure of the produced magnetite nanoparticles.

  17. ALTERNATE REDUCTANT COLD CAP EVALUATION FURNACE PHASE I TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Miller, D.; Zamecnik, J.; Lambert, D.

    2014-04-22

    Savannah River Remediation (SRR) conducted a Systems Engineering Evaluation (SEE) to determine the optimum alternate reductant flowsheet for the Defense Waste Processing Facility (DWPF). Specifically, two proposed flowsheets (nitric–formic–glycolic and nitric–formic–sugar) were evaluated based upon results from preliminary testing. Comparison of the two flowsheets among evaluation criteria indicated a preference towards the nitric–formic–glycolic flowsheet. Further evaluation of this flowsheet eliminated the formic acid1, and as a result, the nitric–glycolic flowsheet was recommended for further testing. Based on the development of a roadmap for the nitric–glycolic acid flowsheet, Waste Solidification Engineering (WS-E) issued a Technical Task Request (TTR) to address flammability issues that may impact the implementation of this flowsheet. Melter testing was requested in order to define the DWPF flammability envelope for the nitric glycolic acid flowsheet. The Savannah River National Laboratory (SRNL) Cold Cap Evaluation Furnace (CEF), a 1/12th scale DWPF melter, was selected by the SRR Alternate Reductant project team as the melter platform for this testing. The overall scope was divided into the following sub-tasks as discussed in the Task Technical and Quality Assurance Plan (TTQAP): Phase I - A nitric–formic acid flowsheet melter test (unbubbled) to baseline the Cold Cap Evaluation Furnace (CEF) cold cap and vapor space data to the benchmark melter flammability models Phase II - A nitric–glycolic acid flowsheet melter test (unbubbled and bubbled) to: o Define new cold cap reactions and global kinetic parameters for the melter flammability models o Quantify off-gas surging potential of the feed o Characterize off-gas condensate for complete organic and inorganic carbon species Prior to startup, a number of improvements and modifications were made to the CEF, including addition of cameras, vessel support temperature measurement, and a heating

  18. Petal Integration for the CMS Tracker End Caps

    CERN Document Server

    Bergauer, Thomas; Friedl, Markus; Hansel, S; Hrubec, Josef; Krammer, Manfred; Pernicka, Manfred; Beaumont, Willem; De Wolf, Eddi A; Bouhali, Othmane; Clerbaux, Barbara; Dewulf, Jean-Paul; De Lentdecker, Gilles; Mahmoud, Tariq; Neukermans, Lionel; Van der Velde, C; Vanlaer, Pascal; Wickens, John; D'Hondt, Jorgen; Goorens, Robert; Heyninck, Jan; Tavernier, Stefaan; Udo, Fred; Van Lancker, Luc; Bonnet, Jean-Luc; De Callatay, Bernard; Delaere, Christophe; Florins, Benoit; Grégoire, Ghislain; Keutgen, Thomas; Lemaître, Vincent; Michotte, Daniel; Militaru, Otilia; Piotrzkowski, Krzysztof; Rouby, Xavier; Teyssier, Daniel; Van der Donckt, M; Ageron, Michel; Baulieu, Guillaume; Bonnevaux, Alain; Boudoul, Gaelle; Chabanat, Eric; Chabert, Eric Christian; Contardo, Didier; Della Negra, Rodolphe; Estre, Nicolas; Giraud, Noël; Haroutunian, Roger; Lumb, Nicholas; Mirabito, Laurent; Perriès, Stephane; Trocmé, Benjamin; Vanzetto, Sylvain; Agram, Jean-Laurent; Drouhin, Frédéric; Ernenwein, Jean-Pierre; Fontaine, Jean-Charles; Berst, Jean-Daniel; Brom, Jean-Marie; Didierjean, Francois; Hosselet, J; Goerlach, Ulrich; Graehling, Philippe; Gross, Laurent; Juillot, Pierre; Lounis, Abdenour; Maazouzi, Chaker; Ollivetto, C; Strub, Roger; Van Hove, Pierre; Adolphi, Roman; Brauer, Richard; Braunschweig, Wolfgang; Esser, Hans; Feld, Lutz; Karpinski, Waclaw; Klein, Katja; König, Stefan; Kosbow, M; Lübelsmeyer, Klaus; Olzem, Jan; Ostapchuk, Andrey; Pandoulas, Demetrios; Pierschel, Gerhard; Schael, Stefan; Schmitz, Stefan Antonius; Schultz von Dratzig, Arndt; Siedling, Rolf; Weber, Markus; Wittmer, Bruno; Wlochal, Michael; Beissel, Franz; Bock, E; Flossdorf, E; Flügge, Günter; Hermanns, Thomas; Heydhausen, Dirk; Jahn, Dieter; Kaussen, Gordon; Linn, Alexander; Poettgens, Michael; Pooth, Oliver; Stahl, Achim; Zoeller, Marc Henning; Butz, Erik; Flucke, Gero; Klanner, Robert; Pein, Uwe; Schirm, Norbert; Schleper, Peter; Steinbruck, G; Stoye, Markus; Van Staa, Rolf; Atz, Bernd; Blüm, Peter; de Boer, Wim; Bogelsbacher, F; Barvich, Tobias; Dehm, Philip; Dierlamm, Alexander; Dirkes, Guido; Fahrer, Manuel; Fernández, J; Frey, Martin; Furgeri, Alexander; Gregoriev, E; Hartmann, Frank; Heier, Stefan; Kaminski, Jochen; Ledermann, Bernhard; Muller, Th; Piaseki, C; Sabellek, Andreas; Simonis, Hans-Jürgen; Steck, Pia; Theel, Andreas; Weiler, Thomas; Weseler, Siegfried; Zhukov, Valery; Freudenreich, Klaus

    2008-01-01

    This note describes the assembly and testing of the 292 petals built for the CMS Tracker End Caps from the beginning of 2005 until the summer of 2006. Due to the large number of petals to be assembled and the need to reach a throughput of 10 to 15 petals per week, a distributed integration approach was chosen. This integration was carried out by the following institutes: I. and III. Physikalisches Institut - RWTH Aachen University; IIHE, ULB \\& VUB Universities, Brussels; Hamburg University; IEKP, Karlsruhe University; FYNU, Louvain University; IPN, Lyon University; and IPHC, Strasbourg University. Despite the large number of petals which needed to be reworked to cope with a late-discovered module issue, the quality of the petals is excellent with less than 0.2\\% bad channels.

  19. Cap assembly for a bundled tube fuel injector

    Energy Technology Data Exchange (ETDEWEB)

    LeBegue, Jeffrey Scott; Melton, Patrick Benedict; Westmoreland, III, James Harold; Flanagan, James Scott

    2016-04-26

    A cap assembly for a bundled tube fuel injector includes an impingement plate and an aft plate that is disposed downstream from the impingement plate. The aft plate includes a forward side that is axially separated from an aft side. A tube passage extends through the impingement plate and the aft plate. A tube sleeve extends through the impingement plate within the tube passage towards the aft plate. The tube sleeve includes a flange at a forward end and an aft end that is axially separated from the forward end. A retention plate is positioned upstream from the impingement plate. A spring is disposed between the retention plate and the flange. The spring provides a force so as to maintain contact between at least a portion of the aft end of the tube sleeve and the forward side of the aft plate.

  20. Geomorphological evidence of warm-humid and cold-dry glaciations in the dry western Cordillera of the tropical Peruvian Andes

    Science.gov (United States)

    Mächtle, B.; Hein, A. S.; Dunai, T.; Eitel, B.

    2012-04-01

    The western Cordillera of the Andes (14°30'S, 74°W) is characterized by high altitudes, strong radiation and semi-arid conditions. Therefore, glacial processes and resulting landforms differ markedly from these of the outer-tropics. However, under sub-arctic conditions similar glacial landforms occur. This congruence can be explained by comparable environmental conditions, which determine the dynamics of ice flow, glacial erosion, debris production as well as moraine deposition. Outside the higher latitudes, typical sub-arctic glacial landforms as controlled moraines and trimline moraines (Evans 2009, Ó Cofaigh et al. 2005) remained undescribed until now. These landforms result from polythermal or cold-basal ice flow, respectively, which is typical for polar conditions. Beside this, we also found steep lateral moraines, which give evidence of increased ice thickness, debris production and deposition and warm-basal ice flow, which is conceivable only for alpine-type valley glaciers. Striations of the bedrock give evidence of accompanied basal erosion. Coexisting trimline moraines and steep lateral moraines rule out the influence of topography on ice thickness and the resulting thermal regime. Therefore, we match the different moraine types to changes in ice thickness, which was controlled by considerable precipitation changes during the last glaciation. An erroneous classification of the observed boulder associations as trimline moraine due to selective erosion after deposition can be excluded due to general arid conditions, slow weathering and the chronological proximity of only a few millennia between both landforms, determined from cosmogenic nuclides. Therefore, the occurrence of different thermal regimes gives evidence of considerable changes in precipitation during the last glaciation - but furthermore requires an associated change in the thermal conditions to explain the very close spatial position of both ice margins. Changes in ice volume must have

  1. Estimation of different flow components in a high-altitude glaciated catchment (Dudh Koshi, Nepalese Himalaya) using a distributed glacio-hydrological model

    Science.gov (United States)

    Mimeau, Louise; Esteves, Michel; Wagnon, Patrick; Brun, Fanny; Condom, Thomas; Jacobi, Hans-Werner; Zin, Isabella

    2017-04-01

    In a context of climate change and of water demand growth, understanding the origin of water flows in the Upper Himalayas is a key issue to estimate the future water resource availability and to plan the future uses of water in downstream regions. One of the main issues in high elevated and glaciated catchments hydrology is the insufficient representation of the cryospheric processes that control the dynamics of ice and snow covered surfaces in distributed hydrological models. Model shortcomings and the lack of meteorological data associated to extreme topography can lead to large uncertainties that need to be quantified. Here we focus on an Upper Dudh Koshi sub-catchment in Nepal with an area of 150 km2 of which 26% was glaciated in 2015. The hydrological regime of this catchment is essentially driven by precipitation and glacier melt during the monsoon season from June to September. This study aims at estimating the contribution of rainfall, glacial and snow melt to the Khumbu River runoff, as well as their seasonal variability during the period [2012-2015]. The physically based glacio-hydrological model DHSVM-GDM (Distributed Hydrology Soil Vegetation Model - Glacier Dynamics Model) was forced with in-situ meteorological data to run simulations for a period of three years. To simulate snow and glacier processes, DHSVM-GDM uses an energy balance model with one ice and two snow layers. For the needs of the study, some parametrizations were adapted in order to take into account cryospheric processes that are not or only partially described in the standard version of DHSVM-GDM, such as snow aging and liquid water transfer through glaciers. The snow albedo representation has been modified to have a more accurate description of the snow pack dynamics. Daily MODIS satellite images were used to validate the simulation of snow albedo and snow cover area. Mass balances from local measurement on the Pokhalde and Changri Nup glaciers, as well as regional geodetic mass

  2. Demineralized bone matrix used for direct pulp capping in rats.

    Directory of Open Access Journals (Sweden)

    Qian Liu

    Full Text Available To evaluate the wound healing process following direct pulp capping with demineralized bone matrix (DBM and calcium hydroxide (Ca(OH2.Fifty 8-weeks-old SPF Wistar male rats were divided into two groups: one was the DBM treated group, and the other was the Ca(OH2 treated group. Pulpotomy was performed on the maxillary first molar of one side of each rat, and the another side was left as the blank control. Rats were sacrificed after each observation period (1, 3, 7, 14 and 28 days and specimen slices were made. Hematoxylin-Eosin (HE staining was used for observing the changes of pulp tissue, and immunohistochemical staining was used for observing the expression of reparative dentinogenesis-related factors runt transcription factor 2 (Runx2, type I collagen (COL I, osteocalcin (OCN and dentin sialoprotein (DSP.Inflammatory cell infiltration (ICI and pulp tissue disorganization (PTD could be observed in both the DBM and Ca(OH2 groups at all observation periods. The DBM group showed slighter ICI on 1 and 28 days and milder PTD on 28 days, with a significant difference (P<0.05. Reparative dentin formation (RDF could initially be observed on 14 days postoperatively, and the DBM group showed more regular and thinner RDF with significant differences on 14 and 28 days compared with the Ca(OH2 group (P<0.05. In both groups, the expression of Runx2, COL I, DSP and OCN were positive. Generally, the expression of these four factors in the DBM group was stronger than the Ca(OH2 group on the same observation periods.DBM had the ability of inducing odontoblast differentiation and promoting dentinogenesis. DBM could initiate physiologic wound healing in pulp and had the ability to promote reparative dentin formation. Consequently, DBM may be an acceptable alternative for direct pulp capping.

  3. Microbial diversity on Icelandic glaciers and ice caps

    Directory of Open Access Journals (Sweden)

    Stefanie eLutz

    2015-04-01

    Full Text Available Algae are important primary colonizers of snow and glacial ice, but hitherto little is known about their ecology on Iceland’s glaciers and ice caps. Due do the close proximity of active volcanoes delivering large amounts of ash and dust, they are special ecosystems. This study provides the first investigation of the presence and diversity of microbial communities on all major Icelandic glaciers and ice caps over a three year period. Using high-throughput sequencing of the small subunit ribosomal RNA genes (16S and 18S, we assessed the snow community structure and complemented these analyses with a comprehensive suite of physical-, geo- and biochemical characterizations of the aqueous and solid components contained in snow and ice samples. Our data reveal that a limited number of snow algal taxa (Chloromonas polyptera, Raphidonema sempervirens and two uncultured Chlamydomonadaceae support a rich community comprising of other micro-eukaryotes, bacteria and archaea. Proteobacteria and Bacteroidetes were the dominant bacterial phyla. Archaea were also detected in sites where snow algae dominated and they mainly belong to the Nitrososphaerales, which are known as important ammonia oxidizers. Multivariate analyses indicated no relationships between nutrient data and microbial community structure. However, the aqueous geochemical simulations suggest that the microbial communities were not nutrient limited because of the equilibrium of snow with the nutrient-rich and fast dissolving volcanic ash. Increasing algal secondary carotenoid contents in the last stages of the melt seasons have previously been associated with a decrease in surface albedo, which in turn could potentially have an impact on the melt rates of Icelandic glaciers.

  4. The Influence of Company Size on Accounting Information: Evidence in Large Caps and Small Caps Companies Listed on BM&FBovespa

    OpenAIRE

    Karen Yukari Yokoyama; Vitor Gomes Baioco; William Brasil Rodrigues Sobrinho; Alfredo Sarlo Neto

    2015-01-01

    In this study, the relation between accounting information aspects and the capitalization level o companies listed on the São Paulo Stock Exchange was investigated, classified as Large Caps or Small Caps, companies with larger and smaller capitalization, respectively, between 2010 and 2012. Three accounting information measures were addressed: informativeness, conservatism and relevance, through the application of Easton and Harris’ (1991) models of earnings informativeness, Basu’s (1997) mod...

  5. 75 FR 70654 - Approval and Promulgation of Air Quality Implementation Plans; Texas; System Cap Trading Program

    Science.gov (United States)

    2010-11-18

    ..., 2001, and August 16, 2007, that create and amend the System Cap Trading (SCT) Program at Title 30 of... of the SCT program because the program lacks several necessary components for emissions trading... submitted by the State of Texas on May 1, 2001, and August 16, 2007, specific to the System Cap Trading (SCT...

  6. MODIS tasselled cap: land cover characteristics expressed through transformed MODIS data

    Science.gov (United States)

    S. E. Lobser; W. B. Cohen

    2007-01-01

    The tasselled cap concept is extended to Moderate Resolution Imaging Spectroradiometer (MODIS) Nadir BRDF-Adjusted Reflectance (NBAR, MOD43) data. The transformation is based on a rigid rotation of principal component axes (PCAs) derived from a global sample spanning one full year of NBAR 16-day composites. To provide a standard for MODIS tasselled cap axes, we...

  7. The role of proximity caps during the annealing of UV-ozone oxidized GaAs

    Science.gov (United States)

    Ghosh, S. C.; Biesinger, M. C.; LaPierre, R. R.; Kruse, P.

    2007-06-01

    This study provides a deeper insight into the chemistry and physics of the common engineering practice of using a proximity cap, while annealing compound semiconductors such as GaAs. We have studied the cases of a GaAs proximity cap, a Si proximity cap, and no proximity cap. Using x-ray photoelectron spectroscopy, it has been found that annealing increases the gallium to arsenic ratio in the oxide layer in all cases. During the annealing of UV-ozone oxidized GaAs, it has been observed that GaAs proximity caps also serve as a sacrificial layer to accelerate the desorption of oxide species. In all cases surface deterioration due to pit formation has been observed, and the depth of pits is found to depend on the effective role played by the capping material. Energy dispersive x-ray analysis provides additional evidence that pits mainly consist of elemental As and gallium oxide, with most of the elemental As situated at the pit-substrate interface. Deposition of a thin layer of gold and subsequent annealing to 500°C for 300s under different capping conditions shows the use of a proximate cap to be practically insignificant in annealing Au deposited films.

  8. One-pot size and shape controlled synthesis of DMSO capped iron ...

    Indian Academy of Sciences (India)

    Abstract. We report here the capping of iron oxide nanoparticles with dimethyl sulfoxide (DMSO) to make chloroform soluble iron oxide nanoparticles. Size and shape of the capped iron oxide nanoparticles are well controlled by simply varying the reaction parameters. The synthesized nanocrystallites were characterized by.

  9. Diurnal Albedo Variations of the Martian North Polar Water Ice Cap

    Science.gov (United States)

    Troy, R. F.; Bass, D.

    2002-01-01

    Presentation of findings regarding diurnal variations in the north polar water ice cap of Mars as part of a larger study of the interannual and seasonal variations of the Martian north polar water ice cap. Additional information is contained in the original extended abstract.

  10. 30 CFR 75.1719-4 - Mining machines, cap lamps; requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mining machines, cap lamps; requirements. 75... Mining machines, cap lamps; requirements. (a) Paint used on exterior surfaces of mining machines shall... frames or reflecting tape shall be installed on each end of mining machines, except that continuous...

  11. Using Airborne SAR Interferometry to Measure the Elevation of a Greenland Ice Cap

    DEFF Research Database (Denmark)

    Dall, Jørgen; Keller, K.; Madsen, S.N.

    2000-01-01

    A digital elevation model (DEM) of an ice cap in Greenland has been generated from airborne SAR interferometry data, calibrated with a new algorithm, and compared with airborne laser altimetry profiles and carrier-phase differential GPS measurements of radar reflectors deployed on the ice cap...

  12. 77 FR 57197 - Proposed Collection; Comment Request for Form 1099-CAP

    Science.gov (United States)

    2012-09-17

    ... information collections, as required by the Paperwork Reduction Act of 1995, Public Law 104-13 (44 U.S.C. 3506(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form 1099-CAP, Changes in Corporate...: Changes in Corporate Control and Capital Structure. OMB Number: 1545-1814. Form Number: 1099-CAP. Abstract...

  13. One-pot size and shape controlled synthesis of DMSO capped iron

    Indian Academy of Sciences (India)

    https://www.ias.ac.in/article/fulltext/boms/029/06/0617-0621. Keywords. Iron oxide; thermal decomposition; TEM; VSM. Abstract. We report here the capping of iron oxide nanoparticles with dimethyl sulfoxide (DMSO) to make chloroform soluble iron oxide nanoparticles. Size and shape of the capped iron oxide nanoparticles ...

  14. Numerical evaluation of the capping tendency of microcrystalline cellulose tablets during a diametrical compression test.

    Science.gov (United States)

    Furukawa, Ryoichi; Chen, Yuan; Horiguchi, Akio; Takagaki, Keisuke; Nishi, Junichi; Konishi, Akira; Shirakawa, Yoshiyuki; Sugimoto, Masaaki; Narisawa, Shinji

    2015-09-30

    Capping is one of the major problems that occur during the tabletting process in the pharmaceutical industry. This study provided an effective method for evaluating the capping tendency during diametrical compression test using the finite element method (FEM). In experiments, tablets of microcrystalline cellulose (MCC) were compacted with a single tabletting machine, and the capping tendency was determined by visual inspection of the tablet after a diametrical compression test. By comparing the effects of double-radius and single-radius concave punch shapes on the capping tendency, it was observed that the capping tendency of double-radius tablets occurred at a lower compaction force compared with single-radius tablets. Using FEM, we investigated the variation in plastic strain within tablets during the diametrical compression test and visualised it using the output variable actively yielding (AC YIELD) of ABAQUS. For both single-radius and double-radius tablets, a capping tendency is indicated if the variation in plastic strain was initiated from the centre of tablets, while capping does not occur if the variation began from the periphery of tablets. The compaction force estimated by the FEM analysis at which the capping tendency was observed was in reasonable agreement with the experimental results. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. An Investigation of Student Response to a Potential Tuition Cap Increase at Casper College

    Science.gov (United States)

    Davis, Elizabeth; Aitchison, Thomas; Allen, Eric; Gomez, Carrie; Laird, Sheree; Raczynska, Kaja

    2015-01-01

    Wyoming Community College Commission policy currently states any student enrolled for more than 12 credit hours will be charged tuition for only 12 credit hours. This policy is referred to as the tuition cap. In November 2010, the commission discussed increasing the tuition cap to 15 credits. An increase from 12 to 15 credits would have…

  16. Short Note Egg-capping in the Southern Ground-Hornbill Bucorvus ...

    African Journals Online (AJOL)

    Egg-capping' describes occurrences of the empty shell from a hatched egg slipping over an unhatched egg from the same clutch. It is a rare phenomenon, occurring typically in <2% of nests monitored. Here I report the first two observed cases of egg-capping in the endangered Southern Ground-Hornbill Bucorvus ...

  17. Mixed Waste Management Facility (MWMF) closure, Savannah River Plant: Clay cap test section construction report

    Energy Technology Data Exchange (ETDEWEB)

    1988-02-26

    This report contains appendices 3 through 6 for the Clay Cap Test Section Construction Report for the Mixed Waste Management Facility (MWMF) closure at the Savannah River Plant. The Clay Cap Test Program was conducted to evaluate the source, lab. permeability, in-situ permeability, and compaction characteristics, representative of kaolin clays from the Aiken, South Carolina vicinity. (KJD)

  18. Medical Malpractice Reform: Noneconomic Damages Caps Reduced Payments 15 Percent, With Varied Effects By Specialty

    Science.gov (United States)

    Seabury, Seth A.; Helland, Eric; Jena, Anupam B.

    2014-01-01

    The impact of medical malpractice reforms on the average size of malpractice payments in specific physician specialties is unknown and subject to debate. We analyzed a national sample of 220,653 malpractice claims from 1985–2010 merged with information on state liability reforms. We estimated the impact of state noneconomic damage caps on average malpractice payment size for physicians overall and for 10 different specialties, and compared how the effects differed according to the restrictiveness of the cap ($250,000 vs. $500,000 cap). We found noneconomic damage caps reduced payments by $42,980 (15%; p<0.001), with a $250,000 cap reducuing average payments by $59,331 (20%; p<0.001), while a $500,000 cap had no significant effect. Effects varied according to specialty and were largest in specialties with high average payments, such as pediatrics. This suggests that the effect of noneconomic damage caps differs by specialty, and only more restrictive caps result in lower average payments. PMID:25339633

  19. The CAP Approach to Modifying Vocational Programs for Handicapped Students. Vol. 3: Health Occupations.

    Science.gov (United States)

    Gugerty, John J.; Morehouse, Nancy

    This teaching guide, the third in a five-volume series (see note), concentrates on the CAP (Cognitive, Affective, and Psychomotor domains) approach for teachers to accomodate handicapped students in vocational classes with focus on health occupations education. Main emphasis is on (1) discussion of CAP functioning as these may affect an…

  20. An Index (PC) Aimed at Monitoring the (P)olar (C)ap for Magnetic Activity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — PC is an index for magnetic activity in the (P)olar (C)ap. It is based on data from a single nearpole station, and aimed to monitor the polar cap magnetic activity...

  1. 3D spherical-cap fitting procedure for (truncated) sessile nano- and micro-droplets & -bubbles

    NARCIS (Netherlands)

    Tan, Huanshu; Peng, S.; Sun, Chao; Zhang, Xuehua; Lohse, Detlef

    2016-01-01

    In the study of nanobubbles, nanodroplets or nanolenses immobilised on a substrate, a cross-section of a spherical cap is widely applied to extract geometrical information from atomic force microscopy (AFM) topographic images. In this paper, we have developed a comprehensive 3D spherical-cap fitting

  2. Redox Control and Hydrogen Production in Sediment Caps Using Carbon Cloth Electrodes

    Science.gov (United States)

    Sun, Mei; Yan, Fei; Zhang, Ruiling; Reible, Danny D.; Lowry, Gregory V.; Gregory, Kelvin B.

    2010-01-01

    Sediment caps that degrade contaminants can improve their ability to contain contaminants relative to sand and sorbent-amended caps, but few methods to enhance contaminant degradation in sediment caps are available. The objective of this study was to determine if, carbon electrodes emplaced within a sediment cap at poised potential could create a redox gradient and provide electron donor for the potential degradation of contaminants. In a simulated sediment cap overlying sediment from the Anacostia River (Washington, DC), electrochemically induced redox gradients were developed within 3 days and maintained over the period of the test (~100 days). Hydrogen and oxygen were produced by water electrolysis at the electrode surfaces and may serve as electron donor and acceptor for contaminant degradation. Electrochemical and geochemical factors that may influence hydrogen production were studied. Hydrogen production displayed zero order kinetics with ~75% coulombic efficiency and rates were proportional to the applied potential between 2.5V to 5V and not greatly affected by pH. Hydrogen production was promoted by increasing ionic strength and in the presence of natural organic matter. Graphite electrode-stimulated degradation of tetrachlorobenzene in a batch reactor was dependent on applied voltage and production of hydrogen to a concentration above the threshold for biological dechlorination. These findings suggest that electrochemical reactive capping can potentially be used to create “reactive” sediments caps capable of promoting chemical or biological transformations of contaminants within the cap. PMID:20879761

  3. Cap morphology after small-incision lenticule extraction and its effects on intraocular scattering

    Directory of Open Access Journals (Sweden)

    Dan Fu

    2018-03-01

    Full Text Available AIM: To investigate cap morphology after small-incision lenticule extraction (SMILE and its effects on intraocular scattering. METHODS: Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at 1d, 1wk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System (OQAS values, and objective scattering index (OSI, were evaluated using OQASTM. RESULTS: Cap thickness decreased from 1d to 1wk (P<0.001, but remained higher than intended thickness of 120 μm after 3mo (P<0.001. Cap thickness in central area was thinner than that of in the paracentral and peripheral areas (P<0.0001. Total number of microdistortions decreased from 1d to 3mo (P<0.0001. Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at 1d and 1mo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at 1d and 1moafter surgery. CONCLUSION: The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.

  4. The Mars water cycle at other epochs: Recent history of the polar caps and layered terrain

    Science.gov (United States)

    Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

    1992-01-01

    The Martian polar caps and layered terrain presumably evolves by the deposition and removal of small amounts of water and dust each year, the current cap attributes therefore represent the incremental transport during a single year as integrated over long periods of time. The role was studied of condensation and sublimation of water ice in this process by examining the seasonal water cycle during the last 10(exp 7) yr. In the model, axial obliquity, eccentricity, and L sub s of perihelion vary according to dynamical models. At each epoch, the seasonal variations in temperature are calculated at the two poles, keeping track of the seasonal CO2 cap and the summertime sublimation of water vapor into the atmosphere; net exchange of water between the two caps is calculated based on the difference in the summertime sublimation between the two caps (or on the sublimation from one cap if the other is covered with CO2 frost all year). Results from the model can help to explain (1) the apparent inconsistency between the timescales inferred for layer formation and the much older crater retention age of the cap and (2) the difference in sizes of the two residual caps, with the south being smaller than the north.

  5. Can sleep microstructure improve diagnosis of OSAS? Integrative information from CAP parameters.

    Science.gov (United States)

    Milioli, Giulia; Bosi, Marcello; Grassi, Andrea; Riccardi, Silvia; Terzano, Mario Giovanni; Cortelli, Pietro; Poletti, Venerino; Parrino, Liborio

    2015-01-01

    The scoring of American Academy of Sleep Medicine (AASM) arousal is mandatory for the definition of respiratory event-related arousal (RERA). However there are other EEG activation phenomena, such as A phases of cyclic alternating pattern (CAP) which are associated with respiratory events in non rapid eye movements (NREM) sleep. This study aims at quantifying the additional value of CAP for the definition of respiratory events and sleep alterations in OSAS. Analysis of polysomnographic recordings from nineteen OSAS patients was carried out. Scoring was focused on investigation of the cerebral response to flow limitation (FL) events. For this purpose we used both CAP rules and AASM arousal criteria. While no difference was demonstrated in the arousal index between mild and moderate-severe OSAS patients, CAP time showed a progressive enhancement from normal subjects (152.5±20.76) to mild (180.64±34.76) and moderate-severe (282.27±58.02) OSAS patients. In NREM sleep, only 41.1% of FL events met the criteria for the definition of RERA, while, 75.5% of FL events ended with a CAP A phase and most FL CAP (69.1%) terminated with a CAP phase A3 subtype. Our data indicate that the RERA scoring has a limited accuracy in the detection of FL events. In NREM sleep, CAP rules provided more information than AASM arousal for the definition of respiratory events and sleep alterations in OSAS.

  6. The Effect of a Homework Grade Cap in an Introductory Finance Class

    Science.gov (United States)

    Cannonier, Colin; Chen, Dennis; Smolira, Joe

    2016-01-01

    The authors used data collected from various sections of principles of finance classes at a private university to examine the effect of utilizing a homework grade cap policy. The results indicate that the homework grade cap policy increased the homework scores and that an increase in homework scores improved performance of the students on exams.…

  7. High-resolution sub-bottom seismic and sediment core records from the Chukchi Abyssal Plain reveal Quaternary glaciation impacts on the western Arctic Ocean

    Science.gov (United States)

    Joe, Y. J.; Seokhoon, Y.; Nam, S. I.; Polyak, L.; Niessen, F.

    2017-12-01

    For regional context of the Quaternary history of Arctic marine glaciations, such as glacial events in northern North America and on the Siberian and Chukchi margins, we used CHIRP sub-bottom profiles (SBP) along with sediment cores, including a 14-m long piston core ARA06-04JPC taken from the Chukchi abyssal plain during the RV Araon expedition in 2015. Based on core correlation with earlier developed Arctic Ocean stratigraphies using distribution of various sedimentary proxies, core 04JPC is estimated to extend to at least Marine Isotope Stage 13 (>0.5 Ma). The stratigraphy developed for SBP lines from the Chukchi abyssal plain to surrounding slopes can be divided into four major seismostratigraphic units (SSU 1-4). SBP records from the abyssal plain show well preserved stratification, whereas on the surrounding slopes this pattern is disrupted by lens-shaped, acoustically transparent sedimentary bodies interpreted as glaciogenic debris flow deposits. Based on the integration of sediment physical property and SBP data, we conclude that these debris flows were generated during several ice-sheet grounding events on the Chukchi and East Siberian margins, including adjacent ridges and plateaus, during the middle to late Quaternary.

  8. Abrupt climatic events recorded by the Ili loess during the last glaciation in Central Asia: Evidence from grain-size and minerals

    Science.gov (United States)

    Song, Yougui; Zeng, Mengxiu; Chen, Xiuling; Li, Yue; Chang, Hong; An, Zhisheng; Guo, Xiaohua

    2018-04-01

    The loess record of Central Asia provides an important archive of regional climate and environmental changes. In contrast to the widely investigated loess deposits in the Chinese Loess Plateau, Central Asian loess-paleosol sequences remain poorly understood. Here, we present an aeolian loess section in the southern Ili Basin. Based on granularity and mineralogical analyses, we reconstruct climatic changes during the last glaciation. The results indicated that most of the abrupt climatic events (such as Dansgaard-Oeschger events and Heinrich events) were imprinted in this loess section, although their amplitudes and ages showed some differences. Compared with the millennial oscillations recoded in loess and stalagmites in East Asia, the arid Central Asia responded more sensitively to the warming events than to the cooling events. The shifting trajectory of westerlies across Central Asia played an important role in dust deposition during the stadials. The North Atlantic climatic signals may have been transmitted from Central Asia to the East Asian monsoon regions via the westerlies.

  9. The Precision of eCAP Thresholds Derived From Amplitude Growth Functions.

    Science.gov (United States)

    Biesheuvel, Jan Dirk; Briaire, Jeroen J; Frijns, Johan H M

    2017-12-06

    An amplitude growth function (AGF) shows the amplitude of an electrically evoked compound action potential (eCAP) as a function of the stimulation current. AGFs can be used to derive the eCAP threshold, which represents the minimum amount of current needed to elicit a measurable eCAP. eCAP thresholds have been widely used clinically to, for example, assist with sound processor programming. However, no eCAP precision has been included to date. The aim of this study was to investigate the precision of eCAP thresholds and determine whether they are precise enough for clinical use. The study is retrospective, and the data comprised 826 AGFs, intraoperatively measured in 111 patients implanted with a HiRes90K cochlear implant (Advanced Bionics). For each AGF, the eCAP threshold was determined using two commonly used methods: linear extrapolation (LE) toward the x axis and detection of the last visible (LV) eCAP. Subsequently, the threshold confidence interval (TCI) of each eCAP threshold was calculated to serve as a metric for precision, whereby a larger TCI means a lower precision or reliability. Additionally, the eCAP thresholds results were compared with most recent behavioral fitting thresholds (T profile) to put the eCAP threshold analysis in clinical context. Thereby, the association between eCAP and behavioral thresholds was calculated, both for all subjects together (group analysis) and, in contrast to previous studies, within individual subjects. Our data show that the TCIs were larger with the LE method than with the LV method. The eCAP thresholds estimated by the LE method were systematically smaller than those estimated by the LV method, while the LE thresholds with the smallest TCIs correlated best with the LV thresholds. Correlation analysis between eCAP and behavioral thresholds revealed correlation coefficients of r = 0.44 and r = 0.54 for the group analysis of LE and LV thresholds, respectively. Within individual subjects, however, the correlation

  10. CARBON EMISSIONS CAPS AND THE IMPACT OF A RADICAL CHANGE IN NUCLEAR ELECTRICITY COSTS

    Directory of Open Access Journals (Sweden)

    Benjamin D. Leibowicz

    2013-01-01

    Full Text Available In this study we analyze the impact of a radical change in nuclear electricity costs on the optimal electricity generation technology mix (EGTM and constrain the value of information (VOI on future nuclear costs. We consider three nuclear cost events and four carbon emissions caps. We develop a two-stage framework for energy-economic model MARKAL to eliminate foresight of future nuclear cost movements. We examine how the EGTM responds to these movements under alternative caps and analyze how these movements affect the cost of each cap. We define the expected savings from perfect foresight (ESPF, an upper bound on the VOI. We found that with current technologies, carbon mitigation that does not rely heavily on nuclear electricity is economically insensible. The Strong Cap is extremely costly because it restricts flexibility to respond to cost signals in choosing among technologies. The ESPF is highest under the Medium Cap by a substantial margin.

  11. Simulation studies on structural and thermal properties of alkane thiol capped gold nanoparticles.

    Science.gov (United States)

    Devi, J Meena

    2017-06-01

    The structural and thermal properties of the passivated gold nanoparticles were explored employing molecular dynamics simulation for the different surface coverage densities of the self-assembled monolayer (SAM) of alkane thiol. The structural properties of the monolayer protected gold nanoparticles such us overall shape, organization and conformation of the capping alkane thiol chains were found to be influenced by the capping density. The structural order of the thiol capped gold nanoparticles enhances with the increase in the surface coverage density. The specific heat capacity of the alkane thiol capped gold nanoparticles was found to increase linearly with the thiol coverage density. This may be attributed to the enhancement in the lattice vibrational energy. The present simulation results suggest, that the structural and thermal properties of the alkane thiol capped gold nanoparticles may be modified by the suitable selection of the SAM coverage density. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Tribological Behaviour of OA-Capped WO3 Nanoparticles as an Additive to Base Oils

    International Nuclear Information System (INIS)

    Siti Fazlili Abdullah

    2008-01-01

    Oleic acid (OA) capped wolfram (VI) oxide, WO 3 nanoparticles were chemically synthesized and characterized by means of Fourier Transform-Infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The tribological properties of the capped WO 3 nanoparticles as an additive in base oils were investigated using a four-ball machine. Results show that OA-capped WO 3 nanoparticles are able to prevent water adsorption and capable of being dispersed stable in organic solvents which is base oils. The as-prepared capped WO 3 nanoparticles have an average size of 15 nm. In addition, OA-capped WO 3 nanoparticles as an additive in base oils perform good anti-wear (AW) and anti-friction (AF) properties owing to the formation of a boundary film. (author)

  13. Effects of contact cap dimension on dry adhesion of bioinspired mushroom-shaped surfaces

    Science.gov (United States)

    Wang, Yue; Shao, Jinyou; Ding, Yucheng; Li, Xiangming; Tian, Hongmiao; Hu, Hong

    2015-03-01

    Dry adhesion observed in small creatures, such as spiders, insects, and geckos, has many great advantages such as repeatability and strong adhesiveness. In order to mimic these unique performances, fibrillar surface with a mushroom shaped end has drawn lots of attentions because of its advantage in efficiently enhancing adhesion compared with other sphere or simple flat ends. Here, in order to study the effects of contact cap dimension on adhesion strength, patterned surfaces of mushroom-shaped micropillars with differing cap diameters are fabricated based on the conventional photolithography and molding. The normal adhesion strength of these dry adhesives with varying cap diameters is measured with home-built equipment. The strength increases with the rise of cap diameter, and interestingly it becomes strongest when the mushroom caps join together.

  14. Chemostratigraphy of Neoproterozoic Banded Iron Formation (BIF)

    DEFF Research Database (Denmark)

    Gaucher, Claudio; Sial, Alcides N.; Frei, Robert

    2015-01-01

    Neoproterozoic banded iron formations (BIFs) are not restricted to the middle Cryogenian, c. 715 Ma glaciation, occurring in Tonian, Cryogenian, and Ediacaran successions. Many Neoproterozoic BIFs were deposited in glacially influenced settings, such as the Rapitan Group (Canada), Jacadigo Group (W...... for the study of BIFs include rare earth element distribution, especially Eu and Ce normalized concentrations, iron speciation, and Nd and Cr isotopes (δ53Cr). Whereas Rapitan type BIFs exhibit no Eu or Ce anomalies, the Algoma-type Neoproterozoic BIFs show both. Positive δ53Cr values characterize glacially...

  15. Zn and C isotopic evidence of climatic change during the Marinoan

    Science.gov (United States)

    Thiemens, M. M.; Moynier, F.; Koeberl, C.; Thiemens, M. H.; Shaheen, R.; Gyollai, I.; Popp, F.; Chong, K.

    2011-12-01

    The "Snowball Earth" events of the Cryogenian period are renowned for their remarkable chemical and isotopic signatures left in the geological record. Through analysis of post Marinoan glaciation cap carbonates from Namibia, specifically from Fransfontein, the Khowarib Valley, and Naraachamspos, a multi isotopic study was undertaken. We analyzed the δ 13C of chemically isolated calcite and dolomite. A moderate depletion of 13C in calcite (δ 13C<0% V-PDB) associated with global glaciations was observed, confirming the event. Associated dolomites also show a 13C depletion, but at a much lower magnitude. Zinc is a trace element that is necessary for all forms of life. Zn does not undergo redox cycling under normal environmental conditions, and biological uptake is one of the few processes that produces isotopic fractionation. This fractionation is in the range of 0.1 permil for the 66Zn/64Zn ratio (δ 66Zn in permil deviation), however with the advent of multi-collection inductively-coupled plasma mass spectrometry (MC-ICP-MS) such variations have become resolvable. We also have measured the Zinc composition of multiple species of lab cultured archaea, and found that the cells are enriched in the light isotopes of Zn compared to the culture medium. By measuring Zn levels in the Cap Carbonates, we seek corroboration for the carbon depletion we find during the glaciation. Zinc should undergo a similarly significant alteration at the mass extinction from climatic shifts inherent to a worldwide glaciation. We find the samples to be relatively consistent, with a δ 66Zn of approximately 0.30 to 0.40 in most places, with a δ 68Zn of double that, values typical of terrestrial rocks. Several sites have a much larger fractionation, with δ 66Zn of up to 0.90 in the Khowarib Valley, and up to 1.06 in the clays at the entrance to the South Valley. These isotopic compositions may be indicative of the massive climatic event leading to the formation of the cap carbonates.

  16. Characterization of the PB2 Cap Binding Domain Accelerates Inhibitor Design

    Directory of Open Access Journals (Sweden)

    Amanda E. Constantinides

    2018-01-01

    Full Text Available X-ray crystallographic structural determinations of the PB2 cap binding domain (PB2cap have improved the conformational characterization of the RNA-dependent RNA polymerase machinery (PA, PB2, and PB1 of the influenza virus. Geometrically, the catalytic PB1 subunit resembles the palm of a human hand. PA lies near the thumb region, and PB2 lies near the finger region. PB2 binds the cap moiety in the pre-mRNA of the host cell, while the endonuclease of PA cleaves the pre-mRNA 10–13 nucleotides downstream. The truncated RNA piece performs as a primer for PB1 to synthesize the viral mRNA. Precisely targeting PB2cap with a small molecule inhibitor will halt viral proliferation via interference of the cap-snatching activity. Wild-type and mutant PB2cap from A/California/07/2009 H1N1 were expressed in Escherichia coli, purified by nickel affinity and size exclusion chromatography, crystallized, and subjected to X-ray diffraction experiments. The crystal of mutant PB2cap liganded with m7GTP was prepared by co-crystallization. Structures were solved by the molecular replacement method, refined, and deposited in the Protein Data Bank (PDB. Structural determination and comparative analyses of these structures revealed the functions of Glu361, Lys376, His357, Phe404, Phe323, Lys339, His432, Asn429, Gln406, and Met401 in PB2cap, and the dissociation of the influenza A PB2cap C-terminal subdomain (residues 446–479 upon ligand binding. Understanding the role of these residues will aid in the ultimate development of a small-molecule inhibitor that binds both Influenza A and B virus PB2cap.

  17. Feasibility of 3D printed air slab diode caps for small field dosimetry.

    Science.gov (United States)

    Perrett, Benjamin; Charles, Paul; Markwell, Tim; Kairn, Tanya; Crowe, Scott

    2017-09-01

    Commercial diode detectors used for small field dosimetry introduce a field-size-dependent over-response relative to an ideal, water-equivalent dosimeter due to high density components in the body of the detector. An air gap above the detector introduces a field-size-dependent under-response, and can be used to offset the field-size-dependent detector over-response. Other groups have reported experimental validation of caps containing air gaps for use with several types of diodes in small fields. This paper examines two designs for 3D printed diode air caps for the stereotactic field diode (SFD)-a cap containing a sealed air cavity, and a cap with an air cavity at the face of the SFD. Monte Carlo simulations of both designs were performed to determine dimensions for an air cavity to introduce the desired dosimetric correction. Various parameter changes were also simulated to estimate the dosimetric uncertainties introduced by 3D printing. Cap layer dimensions, cap density changes due to 3D printing, and unwanted air gaps were considered. For the sealed design the optimal air gap size for water-equivalent cap material was 0.6 mm, which increased to 1.0 mm when acrylonitrile butadiene styrene in the cap was simulated. The unsealed design had less variation, a 0.4 mm air gap is optimal in both situations. Unwanted air pockets in the bore of the cap and density changes introduced by the 3D printing process can potentially introduce significant dosimetric effects. These effects may be limited by using fine print resolutions and minimising the volume of cap material.

  18. A front-end wafer-level microsystem packaging technique with micro-cap array

    Science.gov (United States)

    Chiang, Yuh-Min

    2002-09-01

    The back-end packaging process is the remaining challenge for the micromachining industry to commercialize microsystem technology (MST) devices at low cost. This dissertation presents a novel wafer level protection technique as a final step of the front-end fabrication process for MSTs. It facilitates improved manufacturing throughput and automation in package assembly, wafer level testing of devices, and enhanced device performance. The method involves the use of a wafer-sized micro-cap array, which consists of an assortment of small caps micro-molded onto a material with adjustable shapes and sizes to serve as protective structures against the hostile environments during packaging. The micro-cap array is first constructed by a micromachining process with micro-molding technique, then sealed to the device wafer at wafer level. Epoxy-based wafer-level micro cap array has been successfully fabricated and showed good compatibility with conventional back-end packaging processes. An adhesive transfer technique was demonstrated to seal the micro cap array with a MEMS device wafer. No damage or gross leak was observed while wafer dicing or later during a gross leak test. Applications of the micro cap array are demonstrated on MEMS, microactuators fabricated using CRONOS MUMPS process. Depending on the application needs, the micro-molded cap can be designed and modified to facilitate additional component functions, such as optical, electrical, mechanical, and chemical functions, which are not easily achieved in the device by traditional means. Successful fabrication of a micro cap array comprised with microlenses can provide active functions as well as passive protection. An optical tweezer array could be one possibility for applications of a micro cap with microlenses. The micro cap itself could serve as micro well for DNA or bacteria amplification as well.

  19. Extending permanent volcano monitoring networks into Iceland's ice caps

    Science.gov (United States)

    Vogfjörd, Kristín S.; Bergsson, Bergur H.; Kjartansson, Vilhjálmur; Jónsson, Thorsteinn; Ófeigsson, Benedikt G.; Roberts, Matthew J.; Jóhannesson, Tómas; Pálsson, Finnur; Magnússon, Eyjólfur; Erlendsson, Pálmi; Ingvarsson, Thorgils; Pálssson, Sighvatur K.

    2015-04-01

    The goals of the FUTUREVOLC project are the establishment of a volcano Supersite in Iceland to enable access to volcanological data from the country's many volcanoes and the development of a multiparametric volcano monitoring and early warning system. However, the location of some of Iceland's most active volcanoes inside the country's largest ice cap, Vatnajökull, makes these goals difficult to achieve as it hinders access and proper monitoring of seismic and deformation signals from the volcanoes. To overcome these obstacles, one of the developments in the project involves experimenting with extending the permanent real-time networks into the ice cap, including installation of stations in the glacier ice. At the onset of the project, only one permanent seismic and GPS site existed within Vatnajökull, on the caldera rim of the Grímsvötn volcano. Two years into the project both seismic and GPS stations have been successfully installed and operated inside the glacier; on rock outcrops as well as on the glacier surface. The specific problems to overcome are (i) harsh weather conditions requiring sturdy and resilient equipment and site installations, (ii) darkness during winter months shutting down power generation for several weeks, (iii) high snow accumulation burying the instruments, solar panels and communication and GPS antennae, and in some locations (iv) extreme icing conditions blocking transmission signals and connection to GPS satellites, as well as excluding the possibility of power generation by wind generators. In 2013, two permanent seismic stations and one GPS station were installed on rock outcrops within the ice cap in locations with 3G connections and powered by solar panels and enough battery storage to sustain operation during the darkest winter months. These sites have successfully operated for over a year with mostly regular maintenance requirements, transmitting data in real-time to IMO for analysis. Preparations for two permanent seismic

  20. The impact of a retirement savings account cap.

    Science.gov (United States)

    VanDerhei, Jack

    2013-08-01

    This Issue Brief provides an initial analysis of the potential financial impact on private-sector retirement benefits of the retirement savings account cap included in the Obama administration's FY 2014 budget proposal. It finds that although a very small percentage of current 401(k) participants with IRA accounts have combined balances sufficient to be immediately affected by the proposed limit, over time (and depending on the applicable discount rates, whether a defined benefit pension is involved, and the size of the 401(k) plan) the impact could be much greater. Simulation results for 401(k) participants assuming no defined benefit accruals and no job turnover show that more than 1 in 10 current 401(k) participants are likely to hit the proposed limit sometime prior to age 65, even at the current historically low discount rate of 4 percent. When the simulation is rerun with discount rate assumptions closer to historical averages, the percentage of 401(k) participants likely to be affected by these proposed limits increases substantially: For example, with an 8 percent discount rate, more than 20 percent of the 401(k) participants are simulated to reach the limit prior to retirement. When the impact of stylized, defined benefit account assumptions are added to the analysis, the percentage of 401(k) participants simulated to reach the proposed limits increases even more: In fact, for 401(k) participants assumed to be covered by a 2 percent, three-year, final-average plan with a subsidized early retirement at 62, nearly a third are assumed to be affected by the proposed limit at an 8 percent discount rate. Additional analysis is performed for small plans (those with less than 100 participants) to assess the potential impact of eventual plan terminations if an when the owners and/or key decision makers of the firms reach the cap threshold. Depending on plan size, this may involve as few as 18 percent of the firms (at a 4 percent discount rate) to as many as 75

  1. NOAA's Coastal Change Analysis Program (C-CAP) 1985 to 2001 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  2. NOAA's Coastal Change Analysis Program (C-CAP) 1996 to 2006 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  3. NOAA's Coastal Change Analysis Program (C-CAP) 1996 to 2016 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  4. NOAA's Coastal Change Analysis Program (C-CAP) 2001 to 2010 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  5. Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons

    NARCIS (Netherlands)

    Atashgahi, S.; Maphosa, F.; Vrieze, de J.; Haest, P.J.; Boon, N.; Smidt, H.; Springael, D.; Dejonghe, W.

    2014-01-01

    In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that

  6. NOAA's Coastal Change Analysis Program (C-CAP) 1992 to 2001 Regional Land Cover Change Data - Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  7. NOAA's Coastal Change Analysis Program (C-CAP) 1975 to 2010 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  8. NOAA's Coastal Change Analysis Program (C-CAP) 2006 to 2016 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  9. NOAA's Coastal Change Analysis Program (C-CAP) 1985 to 1996 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  10. NOAA's Coastal Change Analysis Program (C-CAP) 2001 to 2016 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  11. NOAA's Coastal Change Analysis Program (C-CAP) 1996 to 2010 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  12. NOAA's Coastal Change Analysis Program (C-CAP) 2001 to 2006 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  13. NOAA's Coastal Change Analysis Program (C-CAP) 1985 to 2006 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  14. NOAA's Coastal Change Analysis Program (C-CAP) 2001 to 2005 Regional Land Cover Change Data - Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  15. NOAA's Coastal Change Analysis Program (C-CAP) 1992 to 2006 Regional Land Cover Change Data - Coastal United States

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

  16. 488-4D ASH LANDFILL CLOSURE CAP HELP MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, M.

    2014-11-17

    At the request of Area Completion Projects (ACP) in support of the 488-4D Landfill closure, the Savannah River National Laboratory (SRNL) has performed Hydrologic Evaluation of Landfill Performance (HELP) modeling of the planned 488-4D Ash Landfill closure cap to ensure that the South Carolina Department of Health and Environmental Control (SCDHEC) limit of no more than 12 inches of head on top of the barrier layer (saturated hydraulic conductivity of no more than 1.0E-05 cm/s) in association with a 25-year, 24-hour storm event is not projected to be exceeded. Based upon Weber 1998 a 25-year, 24-hour storm event at the Savannah River Site (SRS) is 6.1 inches. The results of the HELP modeling indicate that the greatest peak daily head on top of the barrier layer (i.e. geosynthetic clay liner (GCL) or high density polyethylene (HDPE) geomembrane) for any of the runs made was 0.079 inches associated with a peak daily precipitation of 6.16 inches. This is well below the SCDHEC limit of 12 inches.

  17. Magnetospheric convection and current system in the dayside polar cap

    International Nuclear Information System (INIS)

    Nishida, A.; Mukai, T.; Tsuruda, K.; Hayakawa, H.

    1992-01-01

    Field and particle observations on EXOS-D (Akebono) have yielded new information on convection and current system in the dayside polar cap. Convection patterns are distinctly different depending upon whether IMF B z is northward or southward. The number of convection cells is two when B z is southward but four when B z is northward. Lobe cells in which plasma flows sunward in the region of open field lines are observed as a pair (of which one is in the dawn and the other in the dusk sector) for any polarity of IMF B y and B z . Ions in the keV range precipitate not only in the dayside cusp region but also along the sunward directed streamlines of the dawn and dusk lobe cells. These observations require reconsideration on the position and the extent of the reconnection region on the magnetopause. They also suggest that the magnetotail plays a vital role in some phenomena which have been ascribed to dayside magnetopause processes. We have not been able to find evidence to prove the presence of the viscous cell under southward IMF

  18. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

    International Nuclear Information System (INIS)

    Saba, Luca; Potters, Fons; Lugt, Aad van der; Mallarini, Giorgio

    2010-01-01

    In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.

  19. Linking European Environmental Policies with the new CAP after 2020.

    Science.gov (United States)

    Bouma, Johan

    2017-04-01

    Linking European Environmental Policies with the new CAP after 2020. J.Bouma Em.prof soil science, Wageningen University, the Netherlands EU policy guidelines have been quite successful during the last decades to improve environmental quality of air, water and soil. This deserves credit. For example, the nitrate guideline of 1992 was introduced to deal with an emergency condition of groundwater in many areas of Europa and its quality has greatly improved. Comparable conclusions can be reached for other environmental components. As much new information and technologies have emerged and stakeholders become much more knowlegeable in the modern internet society, it is necessary and possible at this point in time to shift to more local approaches that are fine-tuned to local conditions and that approach land users as partners rather than as adversaries. A unique opportunity arises as the Common Agricultural Policy is being revised and a new policy will be introduced after 2020. Some suggestions will be made, based on the subsidiarity principle where the detail of measures should be in balance with the spatiale level at which they will be enforced: very general at EU level and more specific as one moves down to the level of individual enterprises. The UN Sustainable Development Goals would be an excellent guiding principle at EU level.

  20. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    Science.gov (United States)

    Sharma, Anshu; Baral, Dinesh; Rawat, Kamla; Solanki, Pratima R.; Bohidar, H. B.

    2015-05-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3O4)) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe3O4 and CA-Fe3O4/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, CA-Fe3O4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe3O4) and 189.51 nm (CA-Fe3O4) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2O3/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL-1 with a low detection limit of 0.32 ng mL-1, sensitivity 0.03 Ω/ng ml-1 cm-2, and reproducibility more than 11 times.

  1. The ATLAS semiconductor tracker end-cap module

    CERN Document Server

    Abdesselam, A

    2007-01-01

    The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip buffer. The highest anticipated dose after 10 years operation is in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area , each having 2×768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e- equivalent noise charge (ENC) rising to only 1800e- ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide fle...

  2. SEQUESTERING AGENTS FOR ACTIVE CAPS - REMEDIATION OF METALS AND ORGANICS

    Energy Technology Data Exchange (ETDEWEB)

    Knox, A; Michael Paller, M; Danny D. Reible, D; Xingmao Ma, X; Ioana G. Petrisor, I

    2007-05-10

    This research evaluated organoclays, zeolites, phosphates, and a biopolymer as sequestering agents for inorganic and organic contaminants. Batch experiments were conducted to identify amendments and mixtures of amendments for metal and organic contaminants removal and retention. Contaminant removal was evaluated by calculating partitioning coefficients. Metal retention was evaluated by desorption studies in which residue from the removal studies was extracted with 1 M MgCl{sub 2} solution. The results indicated that phosphate amendments, some organoclays, and the biopolymer, chitosan, were very effective sequestering agents for metals in fresh and salt water. Organoclays were very effective sorbents for phenanthrene, pyrene, and benzo(a)pyrene. Partitioning coefficients for the organoclays were 3000-3500 ml g{sup -1} for benzo(a)pyrene, 400-450 ml g{sup -1} for pyrene, and 50-70 ml g{sup -1} for phenanthrene. Remediation of sites with a mixture of contaminants is more difficult than sites with a single contaminant because metals and organic contaminants have different fate and transport mechanisms in sediment and water. Mixtures of amendments (e.g., organoclay and rock phosphate) have high potential for remediating both organic and inorganic contaminants under a broad range of environmental conditions, and have promise as components in active caps for sediment remediation.

  3. The pulp capping procedure in primary teeth "revisited".

    Science.gov (United States)

    Kopel, H M

    1997-01-01

    The purpose of this review is to "revisit" an earlier paper (1992) on the subject of direct pulp capping in primary teeth and bring some new considerations for the procedure by the use of dentin bonding adhesives. It has come to be recognized that the customary employment of calcium hydroxide for this therapy has some shortcomings that reduce the prognosis for a favorable outcome. For at least a decade, many investigations have found that postoperative sensitivity, thermal stimuli, pulp inflammation and pathosis can be attributed not to the composition of various dental materials and their insertion techniques, but to microleakage with subsequent bacterial invasion at the enamel/restoration and the dentin/pulp interfaces. It is imperative, as pointed out, that there be an impervious resinous bond between the dentin and the dentinopulpal complex which can be achieved by the use of dentinal adhesive agents to eliminate microleakage outward movement of pulpal fluids. Various steps in the bonding technique for the treatment of deep dentin caries and/or a pulp exposure has raised some concerns for their effect on the pulp. This review discusses these concerns, which can lead to the conclusion that the use of dentinal bonding adhesives is a safe and biologically feasible procedure, whether it be in permanent or primary teeth.

  4. Bacterial flagellar capping proteins adopt diverse oligomeric states

    Energy Technology Data Exchange (ETDEWEB)

    Postel, Sandra; Deredge, Daniel; Bonsor, Daniel A.; Yu, Xiong; Diederichs, Kay; Helmsing, Saskia; Vromen, Aviv; Friedler, Assaf; Hust, Michael; Egelman, Edward H.; Beckett, Dorothy; Wintrode, Patrick L.; Sundberg, Eric J. (UV); (Braunschweig); (Maryland-MED); (Konstanz); (Maryland); (Hebrew)

    2016-09-24

    Flagella are crucial for bacterial motility and pathogenesis. The flagellar capping protein (FliD) regulates filament assembly by chaperoning and sorting flagellin (FliC) proteins after they traverse the hollow filament and exit the growing flagellum tip. In the absence of FliD, flagella are not formed, resulting in impaired motility and infectivity. Here, we report the 2.2 Å resolution X-ray crystal structure of FliD fromPseudomonas aeruginosa, the first high-resolution structure of any FliD protein from any bacterium. Using this evidence in combination with a multitude of biophysical and functional analyses, we find thatPseudomonasFliD exhibits unexpected structural similarity to other flagellar proteins at the domain level, adopts a unique hexameric oligomeric state, and depends on flexible determinants for oligomerization. Considering that the flagellin filaments on which FliD oligomers are affixed vary in protofilament number between bacteria, our results suggest that FliD oligomer stoichiometries vary across bacteria to complement their filament assemblies.

  5. Automating CapCom Using Mobile Agents and Robotic Assistants

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Alena, Richard L.; Graham, Jeffrey S.; Tyree, Kim S.; Hirsh, Robert L.; Garry, W. Brent; Semple, Abigail; Shum, Simon J. Buckingham; Shadbolt, Nigel; hide

    2007-01-01

    Mobile Agents (MA) is an advanced Extra-Vehicular Activity (EVA) communications and computing system to increase astronaut self-reliance and safety, reducing dependence on continuous monitoring and advising from mission control on Earth. MA is voice controlled and provides information verbally to the astronauts through programs called "personal agents." The system partly automates the role of CapCom in Apollo-including monitoring and managing navigation, scheduling, equipment deployment, telemetry, health tracking, and scientific data collection. Data are stored automatically in a shared database in the habitat/vehicle and mirrored to a site accessible by a remote science team. The program has been developed iteratively in authentic work contexts, including six years of ethnographic observation of field geology. Analog field experiments in Utah enabled empirically discovering requirements and testing alternative technologies and protocols. We report on the 2004 system configuration, experiments, and results, in which an EVA robotic assistant (ERA) followed geologists approximately 150 m through a winding, narrow canyon. On voice command, the ERA took photographs and panoramas and was directed to serve as a relay on the wireless network.

  6. Size control synthesis of starch capped-gold nanoparticles

    International Nuclear Information System (INIS)

    Tajammul Hussain, S.; Iqbal, M.; Mazhar, M.

    2009-01-01

    Metallic gold nanoparticles have been synthesized by the reduction of chloroaurate anions [AuCl 4 ] - solution with hydrazine in the aqueous starch and ethylene glycol solution at room temperature and at atmospheric pressure. The characterization of synthesized gold nanoparticles by UV-vis spectroscopy, high resolution transmission electron microscopy (HRTEM), electron diffraction analysis, X-ray diffraction (XRD), and X-rays photoelectron spectroscopy (XPS) indicate that average size of pure gold nanoparticles is 3.5 nm, they are spherical in shape and are pure metallic gold. The concentration effects of [AuCl 4 ] - anions, starch, ethylene glycol, and hydrazine, on particle size, were investigated, and the stabilization mechanism of Au nanoparticles by starch polymer molecules was also studied by FT-IR and thermogravimetric analysis (TGA). FT-IR and TGA analysis shows that hydroxyl groups of starch are responsible of capping and stabilizing gold nanoparticles. The UV-vis spectrum of these samples shows that there is blue shift in surface plasmon resonance peak with decrease in particle size due to the quantum confinement effect, a supporting evidence of formation of gold nanoparticles and this shift remains stable even after 3 months.

  7. Conservation and divergence between cytoplasmic and muscle-specific actin capping proteins: insights from the crystal structure of cytoplasmic Cap32/34 from Dictyostelium discoideum

    Directory of Open Access Journals (Sweden)

    Eckert Christian

    2012-06-01

    Full Text Available Abstract Background Capping protein (CP, also known as CapZ in muscle cells and Cap32/34 in Dictyostelium discoideum, plays a major role in regulating actin filament dynamics. CP is a ubiquitously expressed heterodimer comprising an α- and β-subunit. It tightly binds to the fast growing end of actin filaments, thereby functioning as a “cap” by blocking the addition and loss of actin subunits. Vertebrates contain two somatic variants of CP, one being primarily found at the cell periphery of non-muscle tissues while the other is mainly localized at the Z-discs of skeletal muscles. Results To elucidate structural and functional differences between cytoplasmic and sarcomercic CP variants, we have solved the atomic structure of Cap32/34 (32 = β- and 34 = α-subunit from the cellular slime mold Dictyostelium at 2.2 Å resolution and compared it to that of chicken muscle CapZ. The two homologs display a similar overall arrangement including the attached α-subunit C-terminus (α-tentacle and the flexible β-tentacle. Nevertheless, the structures exhibit marked differences suggesting considerable structural flexibility within the α-subunit. In the α-subunit we observed a bending motion of the β-sheet region located opposite to the position of the C-terminal β-tentacle towards the antiparallel helices that interconnect the heterodimer. Recently, a two domain twisting attributed mainly to the β-subunit has been reported. At the hinge of these two domains Cap32/34 contains an elongated and highly flexible loop, which has been reported to be important for the interaction of cytoplasmic CP with actin and might contribute to the more dynamic actin-binding of cytoplasmic compared to sarcomeric CP (CapZ. Conclusions The structure of Cap32/34 from Dictyostelium discoideum allowed a detailed analysis and comparison between the cytoplasmic and sarcomeric variants of CP. Significant structural flexibility could particularly be found within the

  8. Mars seasonal polar caps as a test of the equivalence principle

    International Nuclear Information System (INIS)

    Rubincam, David Parry

    2011-01-01

    The seasonal polar caps of Mars can be used to test the equivalence principle in general relativity. The north and south caps, which are composed of carbon dioxide, wax and wane with the seasons. If the ratio of the inertial (passive) to gravitational (active) masses of the caps differs from the same ratio for the rest of Mars, then the equivalence principle fails, Newton's third law fails, and the caps will pull Mars one way and then the other with a force aligned with the planet's spin axis. This leads to a secular change in Mars's along-track position in its orbit about the Sun, and to a secular change in the orbit's semimajor axis. The caps are a poor Eoetvoes test of the equivalence principle, being 4 orders-of-magnitude weaker than laboratory tests and 7 orders-of-magnitude weaker than that found by lunar laser ranging; the reason is the small mass of the caps compared to Mars as a whole. The principal virtue of using Mars is that the caps contain carbon, an element not normally considered in such experiments. The Earth with its seasonal snow cover can also be used for a similar test.

  9. Mars Seasonal Polar Caps as a Test of the Equivalence Principle

    Science.gov (United States)

    Rubincam, Daivd Parry

    2011-01-01

    The seasonal polar caps of Mars can be used to test the equivalence principle in general relativity. The north and south caps, which are composed of carbon dioxide, wax and wane with the seasons. If the ratio of the inertial to gravitational masses of the caps differs from the same ratio for the rest of Mars, then the equivalence principle fails, Newton's third law fails, and the caps will pull Mars one way and then the other with a force aligned with the planet's spin axis. This leads to a secular change in Mars's along-track position in its orbit about the Sun, and to a secular change in the orbit's semimajor axis. The caps are a poor E6tv6s test of the equivalence principle, being 4 orders-of-magnitude weaker than laboratory tests and 7 orders-of-magnitude weaker than that found by lunar laser ranging; the reason is the small mass of the caps compared to Mars as a whole. The principal virtue of using Mars is that the caps contain carbon, an element not normally considered in such experiments. The Earth with its seasonal snow cover can also be used for a similar test.

  10. Characteristics of helmet or knit cap use in head injury of snowboarders.

    Science.gov (United States)

    Fukuda, Osamu; Hirashima, Yutaka; Origasa, Hideki; Endo, Shunro

    2007-11-01

    The rate of head injury is 1.86-6 times higher for snowboarding than for skiing. Detailed data about the usefulness of a helmet or knit cap for protecting against serious head injuries have not been reported. The present study evaluated the use of a helmet or knit cap for preventing head injuries. Questionnaire data were collected from 1,190 consecutive patients in a hospital during the 1999/2000-2002/2003 winter seasons at Uonuma ski resort, Niigata, Japan. Patients were divided into the helmet, knit cap, and no cap groups. Upper technical level was highest and jumping as the cause of injury was most frequent in the helmet group. After adjustment for other confounders, there was a significant negative association between the occurrence of serious head injury during snowboarding and female sex (adjusted odds ratio 0.55, 95% confidence interval 0.421-0.718, p jumping (adjusted odds ratio 2.25, 95% confidence interval 1.48-3.43, p = 0.0001). Among snowboarding maneuvers, only jumping showed a significant negative association between wearing of a helmet or knit cap and the occurrence of serious head injury (p = 0.036). Snowboarders who wear helmets might attempt dangerous maneuvers causing injuries. Wearing of a helmet or knit cap protected against serious head injuries on jumping. Every snowboarder should wear a helmet or knit cap on jumping to prevent head injury.

  11. Gingival crevicular fluid and serum hCAP18/LL-37 levels in generalized aggressive periodontitis.

    Science.gov (United States)

    Turkoglu, Oya; Emingil, Gulnur; Eren, Gülnihal; Atmaca, Harika; Kutukculer, Necil; Atilla, Gül

    2017-04-01

    hCAP18/LL-37 is an endogenous antibiotic having a role in innate immunity. The aim of the present study was to evaluate serum and gingival crevicular fluid (GCF) hCAP18/LL-37 levels in patients with generalized aggressive periodontitis (G-AgP). Twenty-six G-AgP patients, 24 gingivitis patients, and 25 healthy subjects were included in this study. Periodontal parameters including probing depth, clinical attachment level, plaque index, and papilla bleeding index were recorded. GCF and serum hCAP18/LL-37 levels were analyzed by enzyme-linked immunosorbent assay. GCF hCAP18/LL-37 level was significantly higher in G-AgP compared to others (p = 0.038, p periodontal parameters of sampling sites (p periodontal parameters (p > 0.05). Increased levels of GCF hCAP18/LL-37 in G-AgP might show that it is abundantly expressed in the presence of periodontal tissue destruction. Serum hCAP18/LL-37 levels do not seem to be related with the presence of G-AgP. hCAP18/LL-37 antimicrobial peptide might be associated with periodontal tissue destruction in the presence of aggressive periodontitis.

  12. Combined effect of kinetin and radiation treatment on the cap opening of Agaricus bisporus

    International Nuclear Information System (INIS)

    Kovacs, E.

    1982-01-01

    Cultivated mushrooms (Agaricus bisporus) with a cap diameter of 3-5 cm were incubated at 20 deg C during the experimental period (30-72 h). The degree of cap opening was determined and the data were evaluated. It was found that kinetin solutions in the 0 to 32 mg kg -1 range stimulated the opening of the mushroom cap. The shorter the time elapsed between picking and treating the mushrooms, the greater was the effect. A kinetin solution with a concentration of 100 mg kg -1 inhibited the opening of the cap. Cap opening in irradiated mushrooms cannot be induced even with kinetin concentrations that stimulate cap opening. Treatment with 0, 2.5 and 10 kGy doses of radiation the stimulating effect on cap opening decreased as a function of the rising dose. The radiation effects in kinetin solutions and various natural cytokinins (zeatin, 2iP and 2iPA) were studied and it was found that cytokinin solutions lost 50-60% of their activity after a radiation dose of only 1 kGy. (author)

  13. Differences in cap formation between invasive Entamoeba histolytica and non-invasive Entamoeba dispar.

    Science.gov (United States)

    Chávez-Munguía, Bibiana; Talamás-Rohana, Patricia; Castañón, Guadalupe; Salazar-Villatoro, Lizbeth; Hernández-Ramírez, Verónica; Martínez-Palomo, Adolfo

    2012-07-01

    The rapid redistribution of surface antigen-antibody complexes in trophozoites of the human protozoan parasite Entamoeba histolytica, in a process known as capping, has been considered as a means of the parasite to evade the host immune response. So far, capping has been documented in the invasive E. histolytica, whereas the mobility of surface components in the non-invasive Entamoeba dispar is not known. E. dispar does not induce liver lesions in rodent experimental models, in contrast to the liver abscesses produced by E. histolytica in the same animal model. We have therefore analyzed the mobility of surface receptors to the lectin concanavalin A and of Rab11, a membrane-associated protein, in both species of Entamoebae by confocal fluorescence microscopy and transmission and scanning electron microscopy. The great majority of E. histolytica trophozoites became morphologically polarized through the formation of well-defined caps at the posterior pole of the parasite. Actin colocalized with the lectin caps. Antibodies against the membrane protein Rab 11 also produced capping. In striking contrast, in E. dispar, the mobility of concanavalin A surface receptors was restricted to the formation of irregular surface patches that did no progress to constitute well-defined caps. Also, anti-Rab 11 antibodies did not result in capping in E. dispar. Whether the failure of E. dispar to efficiently mobilize surface molecules in response to lectin or antibodies as shown in the present results is related to its non-invasive character represents an interesting hypothesis requiring further analysis.

  14. Ocular injuries caused by metal caps of carbonated mineral water bottles.

    Science.gov (United States)

    Erdurman, Fazıl Cüneyt; Ceylan, Osman Melih; Hürmeriç, Volkan; Pellumbi, Alfrida; Durukan, Ali Hakan; Sobacı, Güngör

    2013-05-01

    Bottles containing carbonated drinks are potentially hazardous to the eye. In this study, we aimed to document the clinical characteristics and visual outcomes in a series of patients with ocular injury from flying metal caps of carbonated mineral water bottles. Retrospective review of ocular injuries due to metal caps of carbonated mineral water bottles. Sixteen eyes of sixteen patients were included in the study. All of the patients were male, with a mean age of 24 years. Ten of the patients had a history of using improper tools for bottle cap removal. The left eye was involved in twelve cases and the right eye in four cases. All patients had contusion-type closed-globe injury. Varying degrees of hyphema were observed in all patients, and vitreous hemorrhage was present in four. The visual acuity at the last follow-up was 20/20 in 15 of the patients. The use of a bottle cap opener is essential for preventing ocular damage from pressed metal caps of carbonated drinks. In addition to popularising the use of screw cap bottles, warning labels that alert consumers about the possibility of eye injury should be placed on carbonated drinks with pressed metal caps.

  15. Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine Cervix

    DEFF Research Database (Denmark)

    Leonhard, Anne Katrine; Sandager, Puk; Rasmussen, Christina Kjærgaard

    CONTROL ID: 2522419 ABSTRACT FINAL ID: EP22.04 TITLE: Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine Cervix AUTHORS (FIRST NAME, LAST NAME): Anne Katrine Leonhard1, Puk Sandager1, Christina K. Rasmussen1, Hee Lene1, Niels Uldbjerg1 INSTITUTIONS (ALL): 1. De...... cap of PVA constitutes a promising tool for quantitative elastography of the anterior cervical lip, with an ultrasonic image of good quality and ability to significantly distinguish between cervical mechanical properties.......CONTROL ID: 2522419 ABSTRACT FINAL ID: EP22.04 TITLE: Reference Cap of Poly Vinyl Alcohol for Quantitative Elastography of the Human Uterine Cervix AUTHORS (FIRST NAME, LAST NAME): Anne Katrine Leonhard1, Puk Sandager1, Christina K. Rasmussen1, Hee Lene1, Niels Uldbjerg1 INSTITUTIONS (ALL): 1...... inter-intra observer evaluations. Methods: Two types of reference caps were developed. Cap 1 made of Poly Vinyl Alcohol [PVA] with the Young’s modulus [E] of 0.09 N/mm2. Cap 2 made of silicone and oil with the Young’s modulus of 0.4 N/mm2. Elastography was conducted with the caps applied to a 2D...

  16. The Influence of Company Size on Accounting Information: Evidence in Large Caps and Small Caps Companies Listed on BM&FBovespa

    Directory of Open Access Journals (Sweden)

    Karen Yukari Yokoyama

    2015-09-01

    Full Text Available In this study, the relation between accounting information aspects and the capitalization level o companies listed on the São Paulo Stock Exchange was investigated, classified as Large Caps or Small Caps, companies with larger and smaller capitalization, respectively, between 2010 and 2012. Three accounting information measures were addressed: informativeness, conservatism and relevance, through the application of Easton and Harris’ (1991 models of earnings informativeness, Basu’s (1997 model of conditional conservatism and the value relevance model, based on Ohlson (1995. The results appointed that, although the Large Caps present a higher level of conservatism, their accounting figures were less informative and more relevant when compared to the Large Caps companies. Due to the greater production of private information (predisclosure surrounding larger companies, the market would tend to respond less strongly or surprised to the publication of these companies’ accounting information, while the lack of anticipated information would make the effect of disclosing these figures more preponderant for the Small Caps companies.

  17. 76 FR 3142 - Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial...

    Science.gov (United States)

    2011-01-19

    ... AGENCY Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial... agencies, FHFA bases the annual adjustment to the CFI asset cap on the percentage increase in the CPI-U... Agency (FHFA) has adjusted the cap on average total assets that defines a ``Community Financial...

  18. 75 FR 9601 - Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial...

    Science.gov (United States)

    2010-03-03

    ... AGENCY Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial... inflation by applying the CPI-U adjustment resulting in a 1.1 percent increase to the CFI asset cap..., 2009). This Notice announces the annual CPI-U adjustment for the CFI asset cap, effective January 1...

  19. 77 FR 14366 - Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial...

    Science.gov (United States)

    2012-03-09

    ... AGENCY Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial... error, the agency's Federal Register notice announcing the CFI asset cap adjustment for 2011 mistakenly.... Consistent with the practice of other federal agencies, FHFA bases the annual adjustment to the CFI asset cap...

  20. 78 FR 19262 - Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial...

    Science.gov (United States)

    2013-03-29

    ... AGENCY Notice of Annual Adjustment of the Cap on Average Total Assets That Defines Community Financial... agencies, FHFA bases the annual adjustment to the CFI asset cap on the percentage increase in the CPI-U... Agency (FHFA) has adjusted the cap on average total assets that defines a ``Community Financial...

  1. Dependence of the intermixing in InGaAs/InGaAsP quantum well on capping layers

    International Nuclear Information System (INIS)

    Choi, W. J.; Yi, H. T.; Lee, J. I.; Woo, D. H.

    2004-01-01

    The dependence of impurity-free vacancy disordering (IFVD) of InGaAs/InGaAsP quantum well (QW) structure with various semiconductor capping layers over the QW structure on the characteristics of the dielectric capping layer was studied by using SiO 2 and SiN x film as capping layers. Thermal treatment of samples has shown that the amount of blue-shift depends not only on the dielectric capping material but also on the semiconductor capping material over the QW structure. It has been shown that a SiN x dielectric capping layer induces larger blue-shift of bandgap than a SiO 2 capping layer for any semiconductor capping layer. For the semiconductor capping layer, it has been shown that an InP capping layer induced the largest blue-shift of bandgap and an InGaAs capping layer induced the smallest blue-shift of bandgap. The combination of dielectric-semiconductor capping condition has been proposed in order to obtain the largest differential bandgap shift spatially.

  2. Analysis of RNA binding by the dengue virus NS5 RNA capping enzyme.

    Directory of Open Access Journals (Sweden)

    Brittney R Henderson

    Full Text Available Flaviviruses are small, capped positive sense RNA viruses that replicate in the cytoplasm of infected cells. Dengue virus and other related flaviviruses have evolved RNA capping enzymes to form the viral RNA cap structure that protects the viral genome and directs efficient viral polyprotein translation. The N-terminal domain of NS5 possesses the methyltransferase and guanylyltransferase activities necessary for forming mature RNA cap structures. The mechanism for flavivirus guanylyltransferase activity is currently unknown, and how the capping enzyme binds its diphosphorylated RNA substrate is important for deciphering how the flavivirus guanylyltransferase functions. In this report we examine how flavivirus NS5 N-terminal capping enzymes bind to the 5' end of the viral RNA using a fluorescence polarization-based RNA binding assay. We observed that the K(D for RNA binding is approximately 200 nM Dengue, Yellow Fever, and West Nile virus capping enzymes. Removal of one or both of the 5' phosphates reduces binding affinity, indicating that the terminal phosphates contribute significantly to binding. RNA binding affinity is negatively affected by the presence of GTP or ATP and positively affected by S-adensyl methoninine (SAM. Structural superpositioning of the dengue virus capping enzyme with the Vaccinia virus VP39 protein bound to RNA suggests how the flavivirus capping enzyme may bind RNA, and mutagenesis analysis of residues in the putative RNA binding site demonstrate that several basic residues are critical for RNA binding. Several mutants show differential binding to 5' di-, mono-, and un-phosphorylated RNAs. The mode of RNA binding appears similar to that found with other methyltransferase enzymes, and a discussion of diphosphorylated RNA binding is presented.

  3. Increased concentration of. cap alpha. - and. gamma. -endorphin in post mortem hypothalamic tissue of schizophrenic patients

    Energy Technology Data Exchange (ETDEWEB)

    Wiegant, V.M.; Verhoef, C.J.; Burbach, J.P.H.; de Wied, D.

    1988-01-01

    The concentrations of ..cap alpha..-, ..beta..- and ..gamma..-endorphin were determined by radioimmunoassay in HPLC fractionated extracts of post mortem hypothalamic tissue obtained from schizophrenic patients and controls. The hypothalamic concentration of ..cap alpha..- and ..gamma..-endorphin was significantly higher in patients than in controls. No difference was found in the concentration of ..beta..-endorphin, the putative precursor of ..cap alpha..- and ..gamma..-endorphins. These results suggest a deviant metabolism of ..beta..-endorphin in the brain of schizophrenic patients. Whether this phenomenon is related to the psychopathology, or is a consequence of ante mortem farmacotherapy, remains to be established.

  4. FibreBags vs. FibreCaps for acid and neutral detergent fibre analysis

    OpenAIRE

    Koivisto , Jason

    2003-01-01

    International audience; A new procedure for determining acid detergent fibre and neutral detergent fibre (ADF and NDF) was developed to reduce the need for filtration and to allow for batch processing of forage samples. The FibreBag system is an economically necessary evolution of the earlier FibreCap system. The purpose of this enquiry was to determine if the FibreBag is a suitable replacement for the FibreCap. The FibreBag method produced very similar results to the FibreCap system of analy...

  5. Unsteady-Flow Modeling for Emergency Shutdown of the CAP Canal

    OpenAIRE

    Clemmens, Bert; Wahlin, Brian; Shapiro, Marcus; Dent, Patrick

    2016-01-01

    The Central Arizona Project (CAP) is designed to bring about 1.9 ML of Colorado River water per year to Maricopa, Pima, and Pinal counties in Arizona. CAP carries water from the Colorado River at Lake Havasu toTucson. The CAP canal system is a 540 km long system of conveyance system aqueducts, tunnels, pumping plants,pipelines and a large reservoir (just north of Phoenix, AZ). Water is pumped uphill from the Colorado River. This study was conducted for the Hayden-Rhodes Aqueduct of the Centra...

  6. Method for removing strongly adsorbed surfactants and capping agents from metal to facilitate their catalytic applications

    Science.gov (United States)

    Adzic, Radoslav R.; Gong, Kuanping; Cai, Yun; Wong, Stanislaus; Koenigsmann, Christopher

    2016-11-08

    A method of synthesizing activated electrocatalyst, preferably having a morphology of a nanostructure, is disclosed. The method includes safely and efficiently removing surfactants and capping agents from the surface of the metal structures. With regard to metal nanoparticles, the method includes synthesis of nanoparticle(s) in polar or non-polar solution with surfactants or capping agents and subsequent activation by CO-adsorption-induced surfactant/capping agent desorption and electrochemical oxidation. The method produces activated macroparticle or nanoparticle electrocatalysts without damaging the surface of the electrocatalyst that includes breaking, increasing particle thickness or increasing the number of low coordination sites.

  7. Comparison of MRA source image and IVUS for evaluating fibrous cap of carotid plaque

    International Nuclear Information System (INIS)

    Sakamoto, Masahiko; Taoka, Toshiaki; Nakagawa, Hiroyuki; Myochin, Kaoru; Yoshikawa, Kimihiko; Takayama, Katsutoshi; Wada, Takeshi; Iwasaki, Satoru; Fukuzumi, Akio

    2007-01-01

    The purpose is evaluating the usefulness of three-dimensional (3D) time of flight (TOF) MR angiography (MRA) source image for investigating fibrous cap of carotid plaque. The percentage of fibrous cap defect of 17 carotid stenotic lesions was calculated on both MRA source images and intravascular ultrasound (IVUS) images. Five lesions were correlated, but 9 had slight gap (10-20%) and 3 had moderate gap (30-40%). There was significant correlation (P<;0.01, r=0.721) by the Pearson's correlation coefficient. MRA source image can evaluate fibrous cap of carotid plaque. (author)

  8. Contrasting Response of Forest Watersheds in Glaciated and Unglaciated Regions of the Eastern U.S. to Reductions in Acid Deposition

    Science.gov (United States)

    Fakhraei, H.; Driscoll, C. T.

    2016-12-01

    Atmospheric deposition of anthropogenic sulfur and nitrogen compounds (known as acid deposition) primarily originates from emissions from electric utilities, industrial processes, mobile sources and agricultural activities. Marked decline in emissions of acid compounds in recent decades have resulted in a concomitant decrease in the concentrations and fluxes of sulfate and nitrate in wet and dry acid deposition across the eastern U.S. In the Adirondacks, a glaciated region in northeastern U.S., long-term lake chemistry data indicate a correlation between decadal declines in acidic deposition and recovery of acid impaired lakes. However, in Great Smoky Mountains National Park (GRSM), an unglaciated region in southeastern U.S., stream recovery from elevated acid deposition is highly delayed. In this study, a biogeochemical model, PnET-BGC, was used to relate decreases in atmospheric loads of sulfur and nitrogen to acid-base chemistry of water and soil and predict future response of forest watersheds to reductions in acid deposition. The model was calibrated using long-term surface water chemistry data. Our modeling indicates that in the Adirondacks controlling S deposition is much more effective in recovering acidic lakes than N deposition. In contrast to the watersheds in the Adirondacks which are near steady state with respect to S deposition (sulfate input is approximately equal to the sulfate output), watersheds in the GRSM retain a high proportion of sulfate atmospheric deposition due to the high sulfate adsorption capacity of soils, resulting in a delayed response to decreases in acid deposition. Our model calculations suggest that control on S and N deposition is more effective recovering the acid neutralizing capacity of streams in GRSM than equivalent decreases in S deposition. Therefore a national program to aggressively control both S and N emissions will be most effective to mitigate the effects of acid deposition broadly across the eastern U.S.

  9. Linking high-resolution geomorphic mapping, sediment sources, and channel types in a formerly glaciated basin of northeastern Alto-Adige/Sudtirol, Italy

    Science.gov (United States)

    Brardinoni, F.; Perina, E.; Bonfanti, G.; Falsitta, G.; Agliardi, F.

    2012-04-01

    To characterize channel-network morphodynamics and response potential in the Gadria-Strimm basin (14.8 km^2) we conduct a concerted effort entailing: (i) high-resolution mapping of landforms, channel reaches, and sediment sources; and (ii) historical evolution of colluvial channel disturbance through sequential aerial photosets (1945-59-69-82-90-00-06-11). The mapping was carried out via stereographic inspection of aerial photographs, examination of 2.5-m gridded DTM and DSM, and extensive field work. The study area is a formerly glaciated basin characterized by peculiar landform assemblages imposed by a combination of tectonic and glacial first-order structures. The most striking feature in Strimm Creek is a structurally-controlled valley step separating an upper hanging valley, dominated by periglacial and fluvial processes, and a V-notched lower part in which lateral colluvial channels are directly connected to Strimm's main stem. In Gadria Creek, massive kame terraces located in proximity of the headwaters provide virtually unlimited sediment supply to frequent debris-flow activity, making this sub-catchment an ideal site for monitoring, hence studying the mechanics of these processes. Preliminary results point to a high spatial variability of the colluvial channel network, in which sub-sectors have remained consistently active during the study period while others have become progressively dormant with notable forest re-growth. In an attempt to link sediment flux to topography and substrate type, future work will involve photogrammetric analysis across the sequential aerial photosets as well as a morphometric/geomechanical characterization of the surficial materials.

  10. The Clinician-Administered PTSD Scale for DSM-5 (CAPS-5): Development and initial psychometric evaluation in military veterans.

    Science.gov (United States)

    Weathers, Frank W; Bovin, Michelle J; Lee, Daniel J; Sloan, Denise M; Schnurr, Paula P; Kaloupek, Danny G; Keane, Terence M; Marx, Brian P

    2018-03-01

    The Clinician-Administered PTSD Scale (CAPS) is an extensively validated and widely used structured diagnostic interview for posttraumatic stress disorder (PTSD). The CAPS was recently revised to correspond with PTSD criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013). This article describes the development of the CAPS for DSM-5 (CAPS-5) and presents the results of an initial psychometric evaluation of CAPS-5 scores in 2 samples of military veterans (Ns = 165 and 207). CAPS-5 diagnosis demonstrated strong interrater reliability (к = .78 to 1.00, depending on the scoring rule) and test-retest reliability (к = .83), as well as strong correspondence with a diagnosis based on the CAPS for DSM-IV (CAPS-IV; к = .84 when optimally calibrated). CAPS-5 total severity score demonstrated high internal consistency (α = .88) and interrater reliability (ICC = .91) and good test-retest reliability (ICC = .78). It also demonstrated good convergent validity with total severity score on the CAPS-IV (r = .83) and PTSD Checklist for DSM-5 (r = .66) and good discriminant validity with measures of anxiety, depression, somatization, functional impairment, psychopathy, and alcohol abuse (rs = .02 to .54). Overall, these results indicate that the CAPS-5 is a psychometrically sound measure of DSM-5 PTSD diagnosis and symptom severity. Importantly, the CAPS-5 strongly corresponds with the CAPS-IV, which suggests that backward compatibility with the CAPS-IV was maintained and that the CAPS-5 provides continuity in evidence-based assessment of PTSD in the transition from DSM-IV to DSM-5 criteria. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  11. Numerical study of canister filters with alternatives filter cap configurations

    Science.gov (United States)

    Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

    2017-09-01

    Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

  12. Hen's teeth with enamel cap: from dream to impossibility

    Directory of Open Access Journals (Sweden)

    Girondot Marc

    2008-09-01

    Full Text Available Abstract Background The ability to form teeth was lost in an ancestor of all modern birds, approximately 100-80 million years ago. However, experiments in chicken have revealed that the oral epithelium can respond to inductive signals from mouse mesenchyme, leading to reactivation of the odontogenic pathway. Recently, tooth germs similar to crocodile rudimentary teeth were found in a chicken mutant. These "chicken teeth" did not develop further, but the question remains whether functional teeth with enamel cap would have been obtained if the experiments had been carried out over a longer time period or if the chicken mutants had survived. The next odontogenetic step would have been tooth differentiation, involving deposition of dental proteins. Results Using bioinformatics, we assessed the fate of the four dental proteins thought to be specific to enamel (amelogenin, AMEL; ameloblastin, AMBN; enamelin, ENAM and to dentin (dentin sialophosphoprotein, DSPP in the chicken genome. Conservation of gene synteny in amniotes allowed definition of target DNA regions in which we searched for sequence similarity. We found the full-length chicken AMEL and the only N-terminal region of DSPP, and both are invalidated genes. AMBN and ENAM disappeared after chromosomal rearrangements occurred in the candidate region in a bird ancestor. Conclusion These findings not only imply that functional teeth with enamel covering, as present in ancestral Aves, will never be obtained in birds, but they also indicate that these four protein genes were dental specific, at least in the last toothed ancestor of modern birds, a specificity which has been questioned in recent years.

  13. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    International Nuclear Information System (INIS)

    Sharma, Anshu; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B; Baral, Dinesh

    2015-01-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe 3 O 4 )) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe 3 O 4 and CA-Fe 3 O 4 /ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe 3 O 4 , CA-Fe 3 O 4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe 3 O 4 ) and 189.51 nm (CA-Fe 3 O 4 ) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe 2 O 3 /ITO immunosensor exhibits a good detection range of 12.5–500 ng mL −1 with a low detection limit of 0.32 ng mL −1 , sensitivity 0.03 Ω/ng ml −1 cm −2 , and reproducibility more than 11 times. (paper)

  14. Solid state synthesis of starch-capped silver nanoparticles.

    Science.gov (United States)

    Hebeish, A; Shaheen, Th I; El-Naggar, Mehrez E

    2016-06-01

    The present research addresses the establishment of a technique which is solely devoted to environmentally friendly one-pot green synthesis of dry highly stable powdered silver nanoparticles (AgNPs) using starch as both reductant and stabilizing agent in the presence of sodium hydroxide. It is believed that the sodium hydroxide can improve the reduction potential of starch. Thus when the alkali treated starch is submitted to addition of silver nitrate (AgNO3), the alkali treated starch induces the well-established dual role of starch; reduction of silver ions (Ag(+)) to AgNPs and capping the as-formed AgNPs to prevent them from further growth and agglomeration. Beside assessment of AgNPs formation, structural and morphological characteristics of AgNPs are investigated by making use of UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, FT-IR and X-ray diffraction (XRD) analysis. Research outputs signify (a) the absorbance around 410-420nm in the UV-vis spectra of AgNPs appears most, probably owing to the presence of nanosized silver particles and the intensity of this peak increases by increasing AgNO3 concentration; (b) that highly stable AgNPs with well-dispersed particle are successfully prepared using the present research-based innovation; (c) that the size of AgNPs does not exceed 30nm with sphere-like morphology even at the highest Ag(+) concentration employed during synthesis operation; (d) that the XRD and FT-IR confirm the successful preparation of pure AgNPs without noticeable impurities; (d) and that the one-pot synthesis of powdered AgNPs in large scale is clean and easily operated and easily transportation which may be applied as per demands of industries such as textile and painting industry. Copyright © 2016. Published by Elsevier B.V.

  15. Pulsar bi-drifting: implications for polar cap geometry

    Science.gov (United States)

    Wright, Geoff; Weltevrede, Patrick

    2017-01-01

    For many years it has been considered puzzling how pulsar radio emission, supposedly created by a circulating carousel of sub-beams, can produce the drift bands demonstrated by PSR J0815+0939, and more recently PSR B1839-04, which simultaneously drifts in opposing directions. Here, we suggest that the carousels of these pulsars, and hence their beams, are not circular but elliptical with axes tilted with respect to the fiducial plane. We show that certain relatively unusual lines of sight can cause bi-drifting to be observed, and a simulation of the two known exemplars is presented. Although bi-drifting is rare, non-circular beams may be common among pulsars and reveal themselves by having profile centroids displaced from the fiducial plane identified by polarization position angle swings. They may also result in profiles with asymmetric- and frequency-dependent component evolution. It is further suggested that the carousels may change their tilt by specific amounts and later reverse them. This may occur suddenly, accompanying a mode change (e.g. PSR B0943+10), or more gradually and short lived as in `flare' pulsars (e.g. PSR B1859+07). A range of pulsar behaviour (e.g. the shifting drift patterns of PSRs B0818-41 and B0826-34) may also be the result of non-circular carousels with varying orientation. The underlying nature of these carousels - whether they are exclusively generated by polar cap physics or driven by magnetospheric effects - is briefly discussed.

  16. Clinical presentation and diagnostic workup for community-acquired pneumonia: the Gulf Corporation Council CAP Working Group consensus statement.

    Science.gov (United States)

    Memish, Z A; Arabi, Y M; Ahmed, Q A; Al Jahdali, H; Shibl, A M; Niederman, M S

    2007-10-01

    Community-acquired pneumonia (CAP) is diagnosed on the basis of a suggestive history and compatible physical findings and new infiltrates on a chest radiograph. No criteria or combination of criteria based on history and physical examination have been found to be gold standard. With the rise in elderly Gulf Cooperation Council (GCC) residents, CAP is likely to present with non-classical manifestations such as somnolence, new anorexia, and confusion and carries a worse outcome than CAP in their younger counterparts. Tuberculosis should be considered in the differential diagnosis of unresolving CAP in the GCC region. Diagnostic work up depends on severity of CAP, clinical course and underlying risk factors.

  17. Introduction of the human pro. cap alpha. 1(I) collagen gene into pro. cap alpha. 1(I)-deficient Mov-13 mouse cells leads to formation of functional mouse-human hybrid type I collagen

    Energy Technology Data Exchange (ETDEWEB)

    Schnieke, A.; Dziadek, M.; Bateman, J.; Mascara, T.; Harbers, K.; Gelinas, R.; Jaenisch, R.

    1987-02-01

    The Mov-13 mouse strain carries a retroviral insertion in the pro..cap alpha..1(I) collagen gene that prevents transcription of the gene. Cell lines derived from homozygous embryos do not express type I collagen although normal amounts of pro..cap alpha..2 mRNA are synthesized. The authors have introduced genomic clones of either the human or mouse pro..cap alpha..1(I) collagen gene into homozygous cell lines to assess whether the human or mouse pro..cap alpha..1(I) chains can associate with the endogenous mouse pro..cap alpha..2(I) chain to form stable type I collagen. The human gene under control of the simian virus 40 promoter was efficiently transcribed in the transfected cells. Protein analyses revealed that stable heterotrimers consisting of two human ..cap alpha..1 chains and one mouse ..cap alpha..2 chain were formed and that type I collagen was secreted by the transfected cells at normal rates. However, the electrophoretic migration of both ..cap alpha..1(I) and ..cap alpha..2(I) chains in the human-mouse hybrid molecules were retarded, compared to the ..cap alpha..(I) chains in control mouse cells. Inhibition of the posttranslational hydroxylation of lysine and proline resulted in comigration of human and mouse ..cap alpha..1 and ..cap alpha..2 chains, suggesting that increased posttranslational modification caused the altered electrophoretic migration in the human-mouse hybrid molecules. Amino acid sequence differences between the mouse and human ..cap alpha.. chains may interfere with the normal rate of helix formation and increase the degree of posttranslational modifications similar to those observed in patients with lethal perinatal osteogenesis imperfecta. The Mov-13 mouse system should allow the authors to study the effect specific mutations introduced in transfected pro..cap alpha..1(I) genes have on the synthesis, assembly, and function of collagen I.

  18. Developing Extended Strands in Girder-Cap Beam Connections for Positive Moment Resistance

    Science.gov (United States)

    2017-11-01

    In bridges constructed with precast prestressed concrete girders, resistance to seismic effects is achieved by the interaction between the columns, the cap beam and the girders. These components must be connected to provide flexural resistance. Under...

  19. Pseudorotaxane capped mesoporous silica nanoparticles for 3,4-methylenedioxymethamphetamine (MDMA) detection in water

    DEFF Research Database (Denmark)

    Lozano-Torres, Beatriz; Pascual, Lluís; Bernardos, Andrea

    2017-01-01

    Mesoporous silica nanoparticles loaded with fluorescein and capped by a pseudorotaxane, formed between a naphthalene derivative and cyclobis(paraquat-p-phenylene) (CBPQT4+), were used for the selective and sensitive fluorogenic detection of 3,4-methylenedioxymethamphetamine (MDMA)....

  20. Enhancing Photocatalytic Degradation of Methyl Blue Using PVP-Capped and Uncapped CdSe Nanoparticles

    Directory of Open Access Journals (Sweden)

    Kgobudi Frans Chepape

    2017-01-01

    Full Text Available Quantum confinement of semiconductor nanoparticles is a potential feature which can be interesting for photocatalysis, and cadmium selenide is one simple type of quantum dot to use in the following photocatalytic degradation of organic dyes. CdSe nanoparticles capped with polyvinylpyrrolidone (PVP in various concentration ratios were synthesized by the chemical reduction method and characterized. The transmission electron microscopy (TEM analysis of the samples showed that 50% PVP-capped CdSe nanoparticles were uniformly distributed in size with an average of 2.7 nm and shape which was spherical-like. The photocatalytic degradation of methyl blue (MB in water showed efficiencies of 31% and 48% when using uncapped and 50% PVP-capped CdSe nanoparticles as photocatalysts, respectively. The efficiency of PVP-capped CdSe nanoparticles indicated that a complete green process can be utilized for photocatalytic treatment of water and waste water.