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Sample records for 5-0 kyr bp

  1. High temporal Resolution Fire History in Eastern Africa: the Last 16 kyr cal. BP

    NASA Astrophysics Data System (ADS)

    Vanniere, B.; Carcaillet, C.; Garcin, Y.; Vullien, A.; Williamson, D.

    2004-12-01

    Charcoal series, based on a high temporal resolution analysis, at Lake Massoko (9°20' S, 33° 45' E, 770 a.s.l., SW Tanzania) reveals numerous changes of fire regime over the last 16 kyr cal BP. Data are based on the tallying of charcoal from 700 continuous 1 cm thick samples along a 7m long sequence. The structure of charcoal particles is well preserved with an length:width ratio superior to 5; this appears to testify to the local provenance of the material studied and to the rapid transport of particles to the lake. The majority of particles belongs to herbaceous cuticles produced by savanna or bush fires. Time control is supported by 14 radiocarbon dates. Mean time resolution per sample of 17 yr provides the first long detailed biomass burning record in Africa. This record evidences frequent fires events during the last 16 kyr, indicating that fire is a key component of east African ecosystems since, at least, the last glacial stage up to present. From 16 to 12 kyr cal BP, the charcoal influx into the lake is low except during two specific sequences, between 13.5-12.5 kyr cal BP and 14.5-14 kyr cal BP. These may correspond to more arid or more biomass-available phases. Around 10 kyr cal BP, at the early Holocene a greater influx of charcoal is recorded in the lake, probably as a result of a high fire regime likely triggered by severe droughts. Between 8.3 and 1.7 kyr cal BP, the charcoal influx displays a cyclic fire history of ca. 500 yr. Low fire regime, between 3.5-2.5, 5.5-5 and 7.5-7 kyr cal BP, correspond to wetter periods. About 12 sequences of fire increase and decrease are highlighted, which appears to support a high climatic variability during the middle-Holocene. After 1.7 kyr BP, there is a long lasting increase of charcoal influx into the lake, as observed by black carbon analysis (Thevenon et al., 2003). This particular period, without analog since 16 kyr cal BP, is consistent with the development of Iron Age settlements in the region, slash

  2. δ13Catm and [CO2] measurements in Antarctic ice cores, 160 kyrBP - present

    NASA Astrophysics Data System (ADS)

    Eggleston, Sarah; Schmitt, Jochen; Schneider, Robert; Joos, Fortunat; Fischer, Hubertus

    2014-05-01

    Measurements from Antarctic ice cores allow us to reconstruct atmospheric concentrations of climatically important gases including CO2 over the past 800 kyr. Such measurements show that [CO2] has varied in parallel with Antarctic temperatures on glacial-interglacial timescales. Knowledge of the variations of the stable carbon isotope of CO2, δ13Catm, can help us better understand the processes involved in these fluctuations. Here, we present a first complete δ13Catmrecord extending from 160 kyrBP to the present accompanied by δ15N2 measurements during Marine Isotope Stage 3 (MIS 3, 57 - 29 kyrBP). The present record, measured primarily on ice from the EPICA Dome C and Talos Dome ice cores, has an average resolution of 500 yr, focused mainly on the Last Glacial Maximum and termination (180 yr; Schmitt et al., 2012), MIS 3 (660 yr), and Termination II through MIS 5.4 (590 yr; Schneider et al., 2013). Throughout the record, δ13Catm varies between approximately -6.8 and -6.4‰Following a period of relatively constant δ13Catm at the end of MIS 6 (around -6.8), the boundaries of MIS 5 correspond roughly with the beginning and end of a gradual enrichment in this isotope. In comparison, the more recent record depicts three more abrupt excursions to lighter values around 63 - 59, 46, and 17 kyrBP, in each case followed by a slower return (0.4o over the course of 5 - 15 kyr) to more enriched isotopic values. These coincide with Heinrich events 6, 5, and 1, respectively. No direct correlation is observed between the concentration and carbon isotope of CO2 over the last 160 kyr. The data indicate rather that numerous processes, such as uptake and release of atmospheric CO2 by the ocean and land biosphere, perhaps influenced by regions of growing permafrost during MIS 3 and 4, acting on a variety of timescales must be considered in explaining the evolution of δ13Catm on glacial-interglacial timescales. References: Schmitt, J. et al. Science 336, 711-714 (2012) Schneider

  3. Constraint on the penultimate glacial maximum Northern Hemisphere ice topography (≈140 kyrs BP)

    NASA Astrophysics Data System (ADS)

    Colleoni, Florence; Wekerle, Claudia; Näslund, Jens-Ove; Brandefelt, Jenny; Masina, Simona

    2016-04-01

    The penultimate glacial maximum (PGM, ≈140 kyrs BP), is known to be the most extensive glaciation on record that occurred during the last 400 kyrs over Eurasia. We used a coupled Atmosphere-Ocean-Sea-Ice-Land model to simulate the climate of the PGM accounting for a reconstruction of the large PGM Eurasian ice sheet. Due to uncertainties in the PGM Laurentide ice-sheet topography, two simulations with different ice-sheet topographies over North America (large as for the Last Glacial Maximum, LGM and small as for 13 kyrs BP) are performed. Results show that the simulated PGM glacial maximum climates are of comparable magnitude with previous simulations of the LGM in both cases. Assuming a small Laurentide ice-sheet instead of the LGM one in our PGM simulations results in a shift in the planetary waves. This causes an increase in storm track activity over the North Atlantic as well as higher temperatures and precipitation rates over North America, North Atlantic and over the Eurasian ice sheet. In addition, it induces a negative temperature anomaly over East Siberia yielding a thick snow cover, which seems to be in agreement with data from recent Arctic campaigns suggesting that an ice cap developed over Beringia during the PGM. All together, the changes in large-scale circulation and regional climate simulated using a small Laurentide ice sheet match the proxies well. Based on our findings, we suggest that the Laurentide ice sheet might have been smaller during the PGM than during the LGM, in turn also implying a larger Eurasian ice sheet than during the LGM, which is supported by various geological evidence of the PGM.

  4. Intercomparison of Simulated Global Vegetation Distributions in Response to 6 kyr BP Orbital Forcing.

    NASA Astrophysics Data System (ADS)

    Harrison, S. P.; Jolly, D.; Laarif, F.; Abe-Ouchi, A.; Dong, B.; Herterich, K.; Hewitt, C.; Joussaume, S.; Kutzbach, J. E.; Mitchell, J.; de Noblet, N.; Valdes, P.

    1998-11-01

    The response of ten atmospheric general circulation models to orbital forcing at 6 kyr BP has been investigated using the BIOME model, which predicts equilibrium vegetation distribution, as a diagnostic. Several common features emerge: (a) reduced tropical rain forest as a consequence of increased aridity in the equatorial zone, (b) expansion of moisture-demanding vegetation in the Old World subtropics as a consequence of the expansion of the Afro-Asian monsoon, (c) an increase in warm grass/shrub in the Northern Hemisphere continental interiors in response to warming and enhanced aridity, and (d) a northward shift in the tundra-forest boundary in response to a warmer growing season at high northern latitudes. These broadscale features are consistent from model to model, but there are differences in their expression at a regional scale. Vegetation changes associated with monsoon enhancement and high-latitude summer warming are consistent with palaeoenvironmental observations, but the simulated shifts in vegetation belts are too small in both cases. Vegetation changes due to warmer and more arid conditions in the midcontinents of the Northern Hemisphere are consistent with palaeoenvironmental data from North America, but data from Eurasia suggests conditions were wetter at 6 kyr BP than today. The models show quantitatively similar vegetation changes in the intertropical zone, and in the northern and southern extratropics. The small differences among models in the magnitude of the global vegetation response are not related to differences in global or zonal climate averages, but reflect differences in simulated regional features. Regional-scale analyses will therefore be necessary to identify the underlying causes of such differences among models.

  5. Response of the ocean, climate and terrestrial carbon cycle to Holocene freshwater discharge after 8 kyr BP

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Mysak, Lawrence A.

    2005-08-01

    The ``green'' McGill Paleoclimate Model is run from 8 to 0 kyr BP under variable insolation (Milankovitch forcing), Taylor Dome CO2 (radiative forcing) and four prescribed meltwater scenarios (freshwater forcing) due to the retreat of the Laurentide Ice Sheet (LIS). For each scenario, we constrain the total volume of meltwater to be 1.62 × 1015 m3 (sea level-equivalent of 4.62 m), which is obtained from the work of Paterson (1972) and the reconstructed sea level increase between 8 and 6 kyr BP. During each freshwater perturbation, the simulated maximum Atlantic meridional overturning circulation (MOC) intensity is reduced, by amounts of up to 8 Sv. During the time of a weakened MOC, the sea surface temperature is reduced in the high-latitude North Atlantic and increased in the Southern Ocean. Our model results indicate that the freshwater impact on the Holocene climate and terrestrial carbon cycle is likely negligible after the 8.2-kyr cold event. Only a large freshwater perturbation (>0.1 Sv) has a significant impact on the Holocene climate and terrestrial carbon cycle; it results in an enhanced cooling of about 1°C in the Northern Hemisphere (NH) and notable drops in the global net primary productivity (2 PgC/yr) and total land carbon storage (40 PgC).

  6. Climate controls on savanna C3 and C4 expansion in Southern Africa during the last 36 kyr BP

    NASA Astrophysics Data System (ADS)

    Wang, Y. V.; Larsen, T.; Andersen, N.; Blanz, T.; Schneider, R. R.

    2010-12-01

    Savannahs contain a mixture of C3 and C4 vegetation, accounting for more than a quarter of global primary production and are the second most important biome on the continents. However, our understanding on how savannahs will respond to rising CO2 concentration and temperatures or the IPCC estimated decrease in rainfall is not yet clear in spite of potential far reaching socio-economic consequences. In this study, we used the δD and δ13C of sedimentary long-chain n-alkanes (n-C27,29,31,33 ) in concert with reconstructions for sea surface temperatures and fluvial discharge from a marine sediment core (GIK16160-3, 18°14.47’S, 37°52.27’W, 1334m water depth), collected near the Zambezi river mouth to examine savannah responses under different hydrological and climate conditions in Southern Africa during the last 36 kyr BP. Our data show large variability in both δD and δ13C records of the four n-alkanes, with isotopic differences between individual n-alkanes being far more pronounced during the Glacial than during the Deglacial and Holocene. These large differences may be explained by proportionally higher contributions of C4 grasses over C3 trees to the n-C33,31, which seems to be opposite for n-C29. A strong anticorrelation between δD and δ13C from 36 to 16 kyr BP for n-C31 (R2=0.55) and n-C33 (R2=0.70) suggests that δD of these n-alkanes is strongly influenced by changes in vegetation types as well as physiological effects, rather than being directly related to evaporation/ precipitation balance. In contrast, no apparent relationship (R2=0.32) exists between δD and δ13C of n-C29, suggesting that n-C29 is the most promising hydrological proxy due to less variable vegetation type contributions to n-C29 throughout the core. The C4 plant contribution, which was estimated by taking into account the four n-alkanes δ13C signals and their abundance, implies dominance of C4 grass between 36 and 20 kyr BP, and more evenly distributed C3 and C4 vegetation from

  7. Cosmic airburst debris, climate anomalies and societal reactions at 4.2kyr BP: from North Syria to Adelie Land

    NASA Astrophysics Data System (ADS)

    Coqueugniot, E.; Courty, M. M.

    2012-12-01

    The linkages established between dust spikes, unprecedented drought and societal disruption at 4.2 kyr BP have yet failed elucidating the marked increase in aerosol. The volcanic dust component or the erratic spatial pattern are among other puzzling anomalies for a global climate event. We examine here the 4.2 kyr BP debris records from high quality sedimentary archives across the two hemispheres: (1) at Tell Dja'de (Syria), a carbonaceous surface sealed by a EB III/IV Bronze age cemetery; (2) at Tell Ahmar (Syria), the nearly intact collapsed wood frame of the Akkad palace sandwiched between the last 3rd millennium BC plastered floors and massive destruction layers of the monumental buildings; (3) debris accumulation from human processed slags in late Akkaddian contexts at Tell Leilan, Tell Chuera, Tell Beydar, Tell Brak (North Syria) and in an EB III/IV one at Umbaschi (South Syria); (4) a tsunami layer at Banda Aceh (Sumatra); (5) deep sea cores from the Mediterranean and Caspian seas, the Indian and Austral oceans. Using an in situ multi-analytical protocol, we focus on the carbonaceous polymorphs and the composite elements that we formerly defined to tracing hypervelocity cosmic airbursts. A meticulous control of their spatial pattern and structural characteristics at meso to nano-scales has helped to distinguishing the intact debris fall of airburst origin from their human processed-byproducts. The later trace the occurrence in the debris airbursts of highly valuable resources, i.e. fossil combustible with singular properties, that have been exploited since the prehistoric time. Evidence for an oceanic impact at 4.2 kyr BP in the Austral ocean are provided by the 3 m record in the Adelie land high resolution marine core (MD03-2601) showing sudden discharge of ice rafted fine debris with impact features. Their fresh fingerprints in the high to low latitude records from the southern hemisphere indicate massive dispersion of impact debris by air and surface

  8. Impact of climate variability on terrestrial environment in Western Europe between 45 and 9 kyr cal. BP: vegetation dynamics recorded by the Bergsee Lake (Black Forest, Germany).

    NASA Astrophysics Data System (ADS)

    Duprat-Oualid, Fanny; Begeot, Carole; Rius, Damien; Millet, Laurent; Magny, Michel

    2016-04-01

    Between 9 and 45 kyr cal. BP, two great transitions lead the global climate system to evolve from the Last-Glacial period (115-14.7 kyr cal. BP), to two successive warmer periods, the Late-Glacial Interstadial (14.7-11.7 kyr cal. BP) and the Holocene (11.7-0 kyr cal. BP). δ18O variations recorded in Greenland ice cores (GRIP & NGRIP) revealed high frequency climate variability within the Last Glacial. These reference isotopic records highlighted a succession of centennial-to-millennial warm/cold events, the so-called Greenland Interstadials (GI) and Greenland Stadials (GS). The number continental records about the period 14.7-0 kyr cal. BP is substantial. This allowed to understand the vegetation dynamics in response to climate changes this period at the North-Atlantic scale. However, sequences covering the glacial period (beyond 20 kyr cal.BP) remain rare, because of hiatuses mostly due to local glaciers. Therefore, sedimentary continuous records of vegetation dynamics are still needed to better understand climate changes during the Last Glacial in Western Europe (Heiri et al. 2014). Here we present a new high-resolution pollen record from Lake Bergsee (47°34'20''N, 7°56'11''E, 382 m a.s.l). This lake is located south of Black Forest and north of the Alps, beyond the zone of glaciers maximal extension. Therefore it could have recorded the whole last climatic cycle, i.e. 120-0 kyr cal. BP. In 2013, a 29 m long core was extracted from the Bergsee. According to the depth-age model based on 14C AMS dating and the Laacher See Tephra (LST), the record spans continuously at least the last 45 kyrs. The first series of pollen analysis, focused on the 45-9 kyr cal. BP time window, allows us to reconstruct a precise, faithful and continuous vegetation history at the centennial scale. This high temporal resolution enabled to assess the response of vegetation to secular climate events (e.g. GI-4 = 200 yrs). First, our results show that vegetation responded to climate

  9. Multiproxy Records of Indo-Pacific Climate and Environmental Change from Lake Towuti, Indonesia, Since 60 Kyr BP

    NASA Astrophysics Data System (ADS)

    Russell, J. M.; Vogel, H.; Bijaksana, S.; Konecky, B. L.; Wicaksono, S. A.; Costa, K.; Wattrus, N. J.; Melles, M.

    2014-12-01

    Lake Towuti is a large tectonic lake in central Sulawesi, Indonesia that provides a unique opportunity to reconstruct climate and terrestrial environments in the heart of the Indo-Pacific warm pool. Long-term climate variations in this region are governed by a complex interplay between the Australasian monsoons and the ENSO system forced by changing insolation, sea level, ice sheets, and greenhouse gas concentrations. Existing reconstructions suggest heterogeneous responses of Indonesian climate to these forcings, highlighting the need for new long records of regional hydrology. We have developed multiproxy datasets from Lake Towuti and nearby lakes that provide continuous, detailed, and reproducible paleoenvironmental records spanning the past 60 kyr BP. Elemental tracers of terrestrial runoff and compound-specific stable isotope records of vegetation show that wet conditions and rainforest ecosystems persisted during Marine Isotope Stage 3 and the Holocene, and were interrupted by severe drying between 33 and 15 kyr BP when high-latitude ice sheets expanded and global temperatures cooled. This chronology of change implies that central Indonesian hydroclimate varies strongly in response to high-latitude climate forcing. New vegetation records from nearby lakes confirm these findings, but suggest the amplitude of glacial-interglacial changes in vegetation were weaker at high altitude, with important implications for the heterogeneity among Indonesian climate reconstructions. New lithologic and trace element records from Lake Towuti further document the significance of climate changes at the MIS3, 2, and 1 boundaries to Lake Towuti's paleolimnology, heat budget, and seasonal mixing. High-resolution seismic reflection data from Lake Towuti constrain the maximum depth of lake level lowstands during MIS2. Hydrological modeling suggests that precipitation was reduced by at least 50% at that time, an amplitude at or above the upper limits of precipitation changes

  10. Plant wax δD values record changing Eastern Mediterranean atmospheric circulation patterns during the 8.2 kyr B.P. climatic event

    NASA Astrophysics Data System (ADS)

    Schemmel, Fabian; Niedermeyer, Eva M.; Schwab, Valérie F.; Gleixner, Gerd; Pross, Jörg; Mulch, Andreas

    2016-02-01

    Throughout the Holocene, the climate of the Mediterranean region has been strongly influenced by variability in the atmospheric circulation of the high and low latitudes. A prominent example for such Holocene climate perturbations is the '8.2 kyr B.P. climatic event'. Reorganization of Northern Hemisphere atmospheric circulation patterns resulted in variations of temperature and precipitation distribution across the Mediterranean. The effects of changing high- and low-latitude atmospheric circulation on Mediterranean climate in relation to the 8.2 kyr B.P. climatic event are, however, not well understood. Here we present a high-resolution record of stable hydrogen isotope composition of plant-wax n-alkanes (δDwax) across the 8.2 kyr B.P. climatic event from the Tenaghi Philippon peat deposit (NE Greece) in order to characterize patterns of precipitation and changes in atmospheric circulation in the Eastern Mediterranean region. Our record reveals pronounced changes in δDwax that correlate closely with previously published palynological data. A long-term decline in δDwax values characterizes the lower part of the section. The 8.2 kyr B.P. climatic event itself is connected to two distinct positive δDwax excursions: a minor shift in δDwax around 8.2 kyr B.P. and a major shift in δDwax between ca. 8.1 and 8.0 kyr B.P.. The upper part of the section shows a progressive trend towards higher δDwax values. We link shifts in δDwax to changes in Mediterranean air mass trajectories supplying precipitation to NE Greece caused by variations in the relative contributions of northerly-derived, D-depleted moisture and southerly-derived, D-enriched moisture. Possible control mechanisms for alternating air mass trajectories include changes in the influence of the Siberian High and differences in the influence of the African and Asian monsoon circulation on anticyclonic conditions in the Mediterranean region as well as regional inflow of moist air masses from the Aegean Sea.

  11. Freshwater input into the Gulf of Mexico Prior to the 8.2 cal kyr BP Cool Event in Greenland Ice Core Records

    NASA Astrophysics Data System (ADS)

    Lodico, J. M.; Flower, B. P.; Quinn, T. M.

    2004-12-01

    The most prominent event recorded in Greenland ice core records over the past 10 calendar kiloyears before present (cal kyr BP) is an abrupt cooling at 8.2 cal kyr BP, which lasted for 300-400 yrs. It has been proposed that this climatic event was caused by a weakening of the thermohaline circulation in the North Atlantic forced by a vast outflow of freshwater through the Hudson Strait from glacial lakes Agassiz and Ojibway. Sediment core MD02-2550 from Orca Basin located in the northern Gulf of Mexico (GOM) provides an early Holocene record (10 to 7 cal kyr BP) of GOM climate changes, input from the Mississippi River system and adjacent continental areas. Paired analysis of Mg/Ca, a proxy of sea surface temperatures (SSTs), and \\delta18O on the planktonic foraminifera { \\it Globigerinoides ruber } (white variety; 250 -350 μ m) sampled at 0.5 cm (providing ˜20 year resolution), indicate a large isotopic excursion of ˜ -1 ‰ \\delta18O seawater from 8.5 to 8.4 cal kyr BP, coincident with the drainage of glacial lakes Agassiz and Ojibway at 8.47 cal kyr BP. We consider three possible sources for this freshwater pulse: freshwater input from glacial lakes, meltwater input from the drainage of the Laurentide Ice Sheet's final dome, and/or increased precipitation in North American drainage basins. Mg/Ca-SSTs show minimal mean change across the freshwater interval and an average of ˜28 ° C from 7 to 10 cal kyr BP, which is within the current mean SSTs for GOM ( ˜28 ° C). Mg/Ca-SST and \\delta18O seawater time series contain concentrations of variance near 500, 220, 146, and 60 years, significant at the 90 % confidence level, indicating possible sensitivity to solar variations. Ongoing faunal assemblage work will provide additional assessment for SST, sea surface salinity (SSS) and nutrient changes during the early Holocene in the GOM.

  12. A Coral Based Reconstruction of Atmospheric Δ14C through the Mystery Interval (17.5 to 14.5 kyr BP)

    NASA Astrophysics Data System (ADS)

    Mortlock, R. A.; Abdul, N. A.; Wright, J. D.; Fairbanks, R. G.; Cao, L.

    2011-12-01

    Reconstructions of atmospheric Δ14C from various archives (speleothems, planktic foraminifera, surface corals) record a ~ 190 per mil (%) decrease in Δ14C during the Mystery Interval (17.5 to 14.5 kyr BP). It has been suggested that the decrease results from the injection of 14C depleted waters during the deglacial. Supporting evidence comes from benthic forams in sediment cores off Baja, CA that record a 300% decrease in the 14C content of intermediate waters at the same time ice core records display an increase in atmospheric CO2. Records of opal burial in Southern Ocean sediments suggest increased upwelling (and release of 14C depleted CO2 to the atmosphere) during the Mystery Interval. We have updated our previously published record of atmospheric Δ14C with an additional 60-paired radiocarbon and U-series dated surface corals. A unique advantage to using the fossil coral archive is that both radiocarbon and calendar ages can be obtained from the same sample, whereas atmospheric 14C reconstructions generated from deep sea core microfossils require assigned calendar ages which are based on proxies correlated to ice cores and are subject to proxy interpretations, correlation errors, and uncertainties in ice core chronologies. Unfortunately small inaccuracies in the estimated calendar ages lead to large Δ14C errors. The updated coral record adds considerable coverage to both the Mystery Interval (previously constrained by coral data only at the boundaries in INTCAL04 and 09), and for the time period 26 to 18 kyr BP. Our record permits a better estimate as to the timing, duration, and magnitude of the decrease in Δ14C during the Mystery Interval. We observe a break in the declining 27 to 21 kyr BP trend of Δ14C at about 20 kyr BP. From 20 to 18.5 kyr BP Δ14C increases by about 100% to a maximum value of about 430%. Δ14C decreases to 300% by about 17 kyr BP at which time the long term declining trend in Δ14C is re-established and continues throughout the

  13. Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Kubota, Y.; Kimoto, K.; Itaki, T.; Yokoyama, Y.; Miyairi, Y.; Matsuzaki, H.

    2015-06-01

    To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow) at a water depth of 1166 m were reconstructed from 26 kyr BP to present. A new regional Mg / Ca calibration for the benthic foraminifera Cibicidoides wuellerstorfi (type B) was established to convert the benthic Mg / Ca value to BWT, based on 26 surface sediment samples and two core-top samples retrieved around Okinawa Island. During the Last Glacial Maximum (LGM), the δ18Ow in the intermediate water in the northwestern South Pacific was ~0.4‰ lower than in the deep South Pacific, indicating a greater vertical salinity gradient than at present. This salinity (and probably density) structure would have led to stratification in the intermediate and deep Pacific, which would, in turn, have greatly influenced carbon storage during the glacial time. The benthic Mg / Ca and δ18Ow records suggest changes that seem to follow Heinrich event 1 (H1) and the Bølling-Alleød (B/A) and Younger Dryas (YD) intervals, with BWT higher during H1 (~17 kyr BP) and YD (~12 kyr BP) and lower during B/A (~14 kyr BP). The warming in the bottom water during H1 suggests increased contribution of North Pacific Intermediate Water (NPIW) to the subtropical northwestern Pacific and decreased upwelling of cooler waters from the abyssal North Pacific. During the interval from 17 to 14.5 kyr BP, the BWT tended to decrease successively in association with a decrease in δ13C values, presumably as a result of increased upwelling of the abyssal waters to the intermediate depths of the North Pacific caused by shoaling and enhancement of the southward return flow of Pacific Deep Water (PDW). During the Holocene, the millennial- to sub-millennial-scale variations in the BWT generally correlate with the sea surface temperatures in the Okhotsk Sea, the source region of the NPIW, suggesting that changes in the BWT are linked

  14. Distal deltaic deposits document hydrological variability during the past 30 kyrBP in Lake Towuti, Indonesia

    NASA Astrophysics Data System (ADS)

    Vogel, Hendrik; Russell, James M.; Yudawati Cahyarini, Sri; Bijaksana, Satria; Wattrus, Nigel; Rethemeyer, Janet; Melles, Martin

    2014-05-01

    Lake Towuti (2.75°S, 121.5°E; 318 m a.s.l.) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. The Mahalona River constitutes the largest tributary and connects Lake Towuti with the two upstream lakes Matano and Mahalona. The Mahalona River Delta is prograding into the >200m deep northern basin of Lake Towuti. Tracing past variability of Mahalona River discharge is therefore an important puzzle piece for the understanding of depositional dynamics in Lake Towuti as well as catchment hydrology and hydrological connectivity between the Malili Lakes. Distal deltaic deposits can help identifying past variability in river discharge and delta dynamics. Using highly resolved seismic reflection data collected between 2007-2013 we identified a stack of acoustically laminated reflections in Towuti's extensive and morphologically flat deep northern basin. For detailed characterization of these acoustic features we collected a c. 20m long piston core from the basin centre at 200 m water depth reaching back to c. 30 kyrBP. Sediments in this piston core consist to 75% of mass wasting deposits (MWD) of variable thickness that are intercalated with pelagic muds (25%). MWD appear mostly homogenous (silt- to finesand-sized siliciclastics with high amounts of terrestrial plant macrofossils) with only thin (1-3 cm) basal sand layers and clay caps (<1 cm). Pelagic muds appear as thin to medium bedded slightly silty clays that are clearly distinguishable from MWD. The position of MWD identified in our piston core nicely correlates with acoustically laminated reflections identified in seismic profiles crossing the coring site. Based on these combined sedimentological and acoustic datasets we interpret MWD in Towuti's northern basin as distal deltaic deposits originating from the Mahalona River Delta. Frequencies and percentages (in terms of lithofacies contribution) of

  15. Climate dynamics from 17 to 7 kyr BP deduced from a new pollen record from Tenaghi Philippon in comparison with marine palynological data from the northern Aegean Sea

    NASA Astrophysics Data System (ADS)

    Kotthoff, U.; Pross, J.; Müller, U. C.; Dormoy, I.; Peyron, O.; Bordon, A.; Schmiedl, G.

    2009-04-01

    The time interval from 17 to 7 kyr BP is characterized by pronounced climate variability. Among the climatic setbacks during that time, the most prominent are the Younger Dryas (YD) and the 8.2 ka event. The impact of these setbacks on vegetation development is relatively well understood for higher-latitude settings particularly in Central and SW Europe. However, there is still a lack of high-resolution vegetation and climate data for the eastern Mediterranean region, although this region is an ideal natural laboratory for analyzing the effects of short-term climatic change on terrestrial environments due to its intermediate position between the higher-latitude and lower-latitude climate systems. In light of the above, we used a terrestrial core from Tenaghi Philippon, NE Greece, to carry out pollen-based vegetation and climate reconstructions. These indicate that both temperature and precipitation controlled vegetation dynamics until ~15 kyr BP. Between ~15 and ~12.7 kyr BP, temperatures were already comparable to early Holocene circumstances, thus changes in moisture availability appear to have been of major importance. During the interstadials of the Bølling/Allerød interstadial complex (BAC), moisture availability appears higher at Tenaghi Phillipon than during the preceding interval. The following Younger Dryas, although drier and colder than the preceding interstadials of the BAC, appears more humid/warmer than the preceding cold intervals, i.e. the Older and Oldest Dryas and the Pleniglacial. These results are in opposite to findings from a neighbouring marine palynomorph record, where the YD appears to be the coldest/driest interval between 17 and 7 kyr BP, implied by both pollen- and dinocyst-based reconstructions. The early Holocene was punctuated by several short-term climate events. Among these, the North-Atlantic-related 8.2 ka event is most strongly pronounced at Tenaghi Philippon, with winter temperatures declining by almost 4° C, in opposite to

  16. Revision of Ernst Antevs' New England Varve Chronology: A Record of Meltwater Production and Southeastern LIS Recession: 18.2-12.5 kyr BP (Invited)

    NASA Astrophysics Data System (ADS)

    Ridge, J. C.

    2013-12-01

    New varve cores and 54 radiocarbon ages, have allowed the correction, closure of a gap, calibration, and expansion of Ernst Antevs' (1922) New England Varve Chronology from sediments of glacial Lake Hitchcock and it's successors in the Connecticut Valley of western New England (northeastern U.S.A.). The continuous 5659-yr chronology (18.2-12.5 kyr BP) has been renumbered as the North American Varve Chronology. Glacial varve thickness (18.2-13.7 kyr BP) documents abrupt changes in meltwater production related to varying ablation rate (summer climate) that is linked to ice sheet recession rates and advances, i.e. cold intervals are times of thin varves and slower ice recession or glacial readvances. To take advantage of the varve-climate relationship it is necessary to identify non-climatic events that can cause varve thickness to change. This includes sudden changes in lake level and flood events triggered by the abrupt drainage of tributary glacial lakes. A chronology of ice recession for intervals terminated by four stillstands and readvances of 1-2 century durations have been determined for the Connecticut Valley (from S to N): 50-100 m/yr in northern Connecticut to southern Massachusetts; Chicopee Readvance; 30-40 m/yr in central Mass.; Hatfield event; 80-90 m/yr from northern Mass. to central New Hampshire; North Charlestown end moraines; 300 m/yr to northern N.H.; Littleton Readvance; >300 m/yr to Quebec. Meltwater produced by ice recession of 300 m/yr modeled as a receding 1-bar ice sheet profile (from 100 km up ice near ELA to margin, valley width of 80 km, glacier flow rate of 200 m/yr at ELA) would be a minimum glacial meltwater discharge in the Connecticut Valley of ~90 x 109 m3/yr. This is ~10X the modern Conn. River discharge at Walpole, NH compressed almost entirely to the melt season. Non-glacial varves deposited after ice receded from the basin (13.7-12.5 kyr BP) also document climate change as a result of varve thickness varying with changes in

  17. Source to sink element geochemistry and clay mineralogy in Lake Towuti, Indonesia: understanding climate-induced controls on sediment composition during the past 60 kyr BP

    NASA Astrophysics Data System (ADS)

    Morlock, Marina; Vogel, Hendrik; Nigg, Valentin; Hasberg, Ascelina; Melles, Martin; Russell, James M.; Bijaksana, Satria

    2016-04-01

    Lake Towuti is a large (560 km2 surface area; 198 m max. water depth) ultraoligotrophic lake hosted in the East Sulawesi ophiolite, characterised by high iron and very low sulphur contents. The lake is surrounded by several 10s of metres thick deeply weathered laterite soils and closed-canopy rainforest. In May-July 2015, we recovered more than 1000 m of sediment core capturing the entire sediment infill to bedrock in the course of the ICDP Towuti Drilling Project. In the tropics very little is known about the influence of climatic changes on weathering and erosion on glacial-interglacial time-scales. It is expected that varying hydroclimatic conditions will lead to changes in the weathering and erosion rates and greatly influence terrestrial elemental cycling. The direction of change and more quantitative estimates of the rates of changes are, however, unknown. In order to characterise modern erosional processes and element cycling in the lake and its catchment, we collected catchment-characteristic bedrock samples and profiles of their overlying laterites, riverine sediments, and 85 samples of surface sediments from the lake. All samples were analysed for their geochemical and clay-mineralogical (<2 μm) composition in order to define the composition of erodible substrates, trace source-to-sink changes in sediment composition, and assess the spatial variability in Lake Towuti. The relationships found in the modern system were then applied to two sediment cores, dating back 30,000 and 60,000 years BP, respectively. The laterite soils in the catchment show a characteristic zonation with high concentrations of Al, Ti, Fe, and Cr in the uppermost horizon, while Mg is enriched in the saprolite zone directly above bedrock. Weathering intensity increases from bedrock (least weathered) across river bedload of the 15 inlets to the sediments in the deepest basin of the lake (most weathered). The largest inlet to Lake Towuti, the Mahalona River, supplies sediments with low

  18. Which 100-kyr Cycle?

    NASA Astrophysics Data System (ADS)

    Berger, A.; Loutre, M. F.; Mélice, J. L.

    The origin of all the fundamental frequencies characterising the long term variations of the astronomical parameters has been identified. This allows to discuss their inter- relationship and possible changes in times. Different sources for the so-called 100-kyr cycle have been found in the astronomical parameters and in the insolation itself. The most popular 100-kyr cycle is certainly the eccentricity one. Actually, the periods of the most important spectral components of e used in Berger (1978) are 412 885, 14 945, 123 297, 99 590 and 131 248 yr. Instability of the resulting average 100-kyr cy- cle has been shown related to the ~ 400-kyr cycle. The derivative of eccentricity is definitely showing a spectrum dominated by the 100-kyr cycle with the same spectral components as e itself. The inclination of the Earth orbital plane on the ecliptic does not display any 100-kyr cycle, but it is not the case for its inclination on the reference plane for which cycles of 98 046 and 107 478 years appear. Finally the frequency modulation of obliquity is characterised by cycles 171 kyr and 97 kyr long. For inso- lation, it is known that there is only a very weak signal around 100-kyr coming from e itself. However, if we consider the seasonal cycle at the equator, its amplitude varies with cycles of 400 kyr, 100 kyr, 41 kyr, 10 kyr and 5 kyr, all related to e. Although all these cycles are close to the 100 kyr cycle found in geological data, the origin of this kind of cycle can be best identified by comparing the proxy record to the re- sponse of the climate system to the astronomical forcing. This forcing signal which contains, in one way or another, the astronomical characteristics mentioned above is, at least, partly distorted and transformed, a modification which can only be estimated through climate models. Such a climate model has been developed in the early 80Ss in Louvain-la-Neuve and used since to simulate the last and next glacial-interglacial cycles.

  19. Late Holocene subalpine lake sediments record a multi-proxy shift to increased aridity at 3.65 kyr BP, following a millennial-scale neopluvial interval in the Lake Tahoe watershed and western Great Basin, USA

    NASA Astrophysics Data System (ADS)

    Noble, Paula; Zimmerman, Susan; Ball, Ian; Adams, Kenneth; Maloney, Jillian; Smith, Shane

    2016-04-01

    A mid Holocene dry period has been reported from lake records in the Great Basin and Sierra Nevada, yet the spatial and temporal extent of this interval is not well understood. We present evidence for a millennial-scale interval of high winter precipitation (neopluvial) at the end of the mid Holocene in the Lake Tahoe-Pyramid Lake watershed in the northern Sierra Nevada that reached its peak ˜3.7 kcal yr BP. A transect of 4 cores recovered from Fallen Leaf Lake in the Tahoe Basin were dated using AMS14C on plant macrofossils, and analyzed using scanning XRF, C and N elemental and stable isotope measurements, and diatoms as paleoclimate proxies. Fallen Leaf Lake is a deep glacially-derived lake situated in the Glen Alpine Valley at an elevation of 1942m, ˜45 m above the level of Lake Tahoe. In Fallen Leaf Lake, the end of the neopluvial is dated at 3.65 ± 0.09 kcal yr BP, and is the largest post-glacial signal in the cores. The neopluvial interval is interpreted to be a period of increased snowpack in the upper watershed, supported by depleted g δ13Corg (-27.5) values, negative baseline shifts in TOC and TN, lower C:N, and high abundances of Aulacoseira subarctica, a winter-early spring diatom. Collectively, these proxies indicate cooler temperatures, enhanced mixing, and/or shortened summer stratification resulting in increased algal productivity relative to terrestrial inputs. The neopluvial interval ends abruptly at 3.65 ka, with a change from mottled darker opaline clay to a homogeneous olive clay with decreased A. subarctica and opal, and followed by a 50% reduction in accumulation rates. After this transition δ13Corg becomes enriched by 2‰ and TOC, TN, and C:N all show the start of positive trends that continue through the Holocene. Pyramid Lake is an endorheic basin situated at the terminal end of the watershed, and inflow arrives from the Lake Tahoe basin via the Truckee River. At Pyramid Lake, existing ages on paleo-shorelines indicate a significant

  20. Bottom-Water Oxygenation in the Central Gulf of California for the Last 16 kyrs

    NASA Astrophysics Data System (ADS)

    Karlin, R. E.; Harris, A.

    2006-12-01

    Laminated sediment records from the central Gulf of California reveal changes in oxygen-related microfabric, which can be directly related to variations in the intensity and location of the oxygen-minimum zone (OMZ) for the last 16,000 years. The intensity and location of the OMZ depends on the interaction of primary productivity and bottom water oxygen availability created by compositional variations and replenishment speed of Pacific Intermediate Water (PIW). Seven cores recovered from water depths ranging from 525 to 820 meters directly sample changes in the extent of the OMZ and PIW. Chronologies for six Atlantis II cores are based on independent radiocarbon ages, stratigraphic correlation, oxygen-isotope stratigraphy, and lamina counts from x-radiograph images. At DSDP Site 480, the varve chronology, when compared to an independent age model based on radiocarbon ages and secular variation curves, indicates that the Site 480 record is continuous and has an age error comparable to that of ice core and tree ring records. Bottom-water oxygenation was relatively higher from 17 to ~15.5 cal kyrs BP and ~12.3 to ~11.9 cal kyrs BP, was lower from ~15.5 to ~12.3 cal kyrs BP and ~11.6 to 7 cal kyrs and began increasing again after 7 cal kyrs. Changes in microfabric and, hence, bottom water oxygenation were not synchronous in the central Gulf. The change from oxic to more anoxic conditions near the end of the last glacial and the Younger Dryas began at depth and progressively shallowed with time. The transition to more oxic conditions in the Younger Dryas also began at depth and shallowed with time. The relationships between proxies for PIW oxygenation, primary productivity, and sediment flux suggest that productivity controlled bottom-water oxygenation from 17 to 11.6 cal kyrs BP. Lower oxygen availability due to less PIW input appears to have controlled bottom-water oxygenation from 11.6 to ~10 cal kyrs BP. No clear basin-wide relationship is found between productivity

  1. Modelling The Magnitude of Climatic Changes In East Africa During The Last 150 Kyr

    NASA Astrophysics Data System (ADS)

    Bergner, A. G. N.; Duehnforth, M.; Strecker, M. R.; Trauth, M. H.

    In order to assess the links between hydrology and climate in continental basins, water- balance modelling of lakes is a useful tool, because lakes are sensitive recorders of hydrologic fluctuations due to regional climate change. In the Central Kenya Rift, 40Ar/39Ar- dated lake sediments from the Naivasha and Nakuru-Elmenteita basins provide detailed information on extent and chronology of environmental changes and their effect on paleo-lakes. Mapping of lake deposits in surface outcrops and boreholes suggests that the extent of the lakes was comparable during highstands at 9 and 138 kyr BP, respectively, but significantly different compared to present conditions. Whereas the present Lake Naivasha (180 km2), Nakuru (40 km2) and Elmenteita (26 km2) have a water volume < 1 km3, paleo-lake areas were larger by factor of 3 to 4, and lake volumes increased by factor of 50 to 60. Simultaneously, these lakes were subject to considerable hydrochemical changes. For example, diatom and authigenic mineral assemblages indicate pH fluctuations between 7 and 11 for Lake Naivasha during the last 150 kyr, in contrast to a pH of 8.2. Hydroclimatic lake-balance modelling of the most prominent lake phases of Lake Naivasha and Lake Nakuru-Elmenteita were performed in order to compare past and present-day climate conditions. Our results show that a +15% increase in precipitation compared to modern values may have been responsible for a lake-level highstand at 9 kyr BP. In addition, the increase in precipitation may reach as much as +30% if a change in vegetation due to increased humidity in the catchment is taken into account. Preliminary modelling results for an earlier highstand of Lake Naivasha at 138 kyr BP suggests hydroclimatic conditions comparable to the Holocene highstand. From the analysis of lake sediments we infer that Lake Nakuru-Elmenteita also experienced significant lake highstands at 138 kyr BP most probably caused by the same wetter cli- mate conditions. Our

  2. Abrupt Climatic Events Observed in Organic-Rich Sediments From Lake Tanganyika, Tropical East Africa, Over the Past 50 kyr

    NASA Astrophysics Data System (ADS)

    Burnett, A. P.; Weyhenmeyer, C. E.; Scholz, C. A.; Swart, P. K.

    2006-12-01

    Abrupt climate changes such as Dansgaard-Oeschger Cycles and Heinrich Events were first detected in high- latitude records, but an increasing number of studies suggest that these rapid changes are actually global events. The degree to which the tropics drive, control and/or respond to such rapid changes is still poorly understood due to a scarcity of data from low-latitude regions. A recently acquired sediment core from Lake Tanganyika, East Africa, provides a unique archive to study abrupt climate events in the tropics throughout the last glaciation. The core provides a continuous, undisturbed and high resolution climate record over the past 100 kyr. An age-depth model based on 25 new radiocarbon dates provides a solid, high-resolution chronology for the past 50 kyr. Throughout this time, several rapid changes in paleoclimate proxy data are observed along the core. Sedimentation rates remained fairly constant from the Holocene until the Last Glacial Maximum (LGM) but increased abruptly from ~80 mm/1000 yr to ~150 mm/1000 yr around 18 kyr BP. At the same time, the sediment record reveals a sudden increase in total organic carbon (TOC) from 4% to 12% indicating a rapid increase in organic matter contributions at the end of the LGM. Abrupt changes in TOC and δ13C values are also found at ~38 kyr, ~30 kyr and ~16 kyr BP, suggesting a possible link to Heinrich events 4, 3 and 1, respectively. Forthcoming very high-resolution analyses, to augment existing low-resolution data, include δ13C, δ15N, C/N ratios and TOC values. Furthermore, TEX86 measurements will be carried out to determine whether the observed changes in organic matter contributions are associated with changes in water temperatures. In combination with the solid 14C chronology, the new data will allow us to precisely determine the onset, timing and nature of abrupt changes and evaluate them in the global context.

  3. Terrestrial biosphere changes over the last 120 kyr

    NASA Astrophysics Data System (ADS)

    Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

    2016-01-01

    A new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.

  4. Sediment provenance and paleoenvironmental change in the Ulleung Basin of the East (Japan) Sea during the last 21 kyr

    NASA Astrophysics Data System (ADS)

    Xu, Zhaokai; Lim, Dhongil; Choi, Jinyong; Li, Tiegang; Wan, Shiming; Rho, Kyoungchan

    2014-10-01

    Despite the well-reconstructed paleoceanography of the late Quaternary deposits in the East (Japan) Sea (ES), provenances of terrigenous sediments and a comprehensive interpretation of their variations since the Last Glacial Maximum remain unclear, especially in regard to the mainland China- and Taiwan-derived matter. Grain size, conservative trace elements, rare earth elements (REEs), Nd isotope, and clay mineralogy of core sediments from the Ulleung Basin of the ES were investigated for better understanding of detrital sediment provenance and transport process and then their forcing mechanisms over the last 21 kyr. Geochemical-mineralogical multi-indices in this study showed notable three-phase changes in sediment provenance, which can be closely related to sea-level fluctuation, development of the Tsushima Warm Current as well as intermittent influence from the East Asian summer monsoon climate evolution. During Unit 1 (21.1-8.4 kyr BP) when the Tsushima Warm Current was absent in the ES, the paleo-Changjiang and the paleo-Huanghe mouth might be situated close to the study area and thus mainland China could have played major role in the southwestern Ulleung Basin sedimentation. In particular, the formation of rhythmic dark-colored alternation in Unit 1 is possibly attributable to the pulse of paleo-Huanghe discharge associated with centurial- to millennial-scale variability in the East Asian summer monsoon. In Unit 2 (8.4-7.2 kyr BP), these river mouths gradually retreated to their present positions with global sea-level rise, leading to decreasing terrigenous sediment supply from mainland China to the study area. Since 7.2 kyr BP (Unit 3), sedimentation in the Ulleung Basin should still be mainly derived from mainland China. Meanwhile, increasing chlorite/kaolinite ratio but decreasing εNd value revealed that terrigenous matter from Taiwan might have been limitedly transported northward to the study area by the fully evolved Tsushima Warm Current. A prominent

  5. Observation of 23 supernovae that exploded <300 pc from Earth during the past 300 kyr

    SciTech Connect

    Firestone, R. B.

    2014-07-01

    Four supernovae (SNe), exploding ≤300 pc from Earth, were recorded 44, 37, 32, and 22 kyr ago in the radiocarbon ({sup 14}C) record during the past 50 kyr. Each SN left a nearly identical signature in the record, beginning with an initial sudden increase in atmospheric radiocarbon, when the SN exploded, followed by a hiatus of 1500 yr, and concluding with a sustained 2000 yr increase in global radiocarbon due to γ-rays produced by diffusive shock in the SN remnant (SNR). For the past 18 kyr excess radiocarbon has decayed with the {sup 14}C half-life. SN22kyrBP, is identified as the Vela SN that exploded 250 ± 30 pc from Earth. These SN are confirmed in the {sup 10}Be, {sup 26}Al, {sup 36}Cl, and NO{sub 3}{sup −} geologic records. The rate of near-Earth SNe is consistent with the observed rate of historical SNe giving a galactic rate of 14 ± 3 kyr{sup –1} assuming the Chandra Galactic Catalog SNR distribution. The Earth has been used as a calorimeter to determine that ≈2 × 10{sup 49} erg were released as γ-rays at the time of each SN explosion and ≈10{sup 50} erg in γ-rays following each SN. The background rate of {sup 14}C production by cosmic rays has been determined as 1.61 atoms cm{sup –2} s{sup –1}. Approximately 1/3 of the cosmic ray energy produced by diffusive shock in the SNR was observed to be emitted as high-energy γ-rays. Analysis of the {sup 10}Be/{sup 9}Be ratio in marine sediment identified 19 additional near-Earth SNe that exploded 50-300 kyr ago. Comparison of the radiocarbon record with global temperature variations indicated that each SN explosion is correlated with a concurrent global warming of ≈3°C-4°C.

  6. AutoGen Version 5.0

    NASA Technical Reports Server (NTRS)

    Gladden, Roy E.; Khanampornpan, Teerapat; Fisher, Forest W.

    2010-01-01

    Version 5.0 of the AutoGen software has been released. Previous versions, variously denoted Autogen and autogen, were reported in two articles: Automated Sequence Generation Process and Software (NPO-30746), Software Tech Briefs (Special Supplement to NASA Tech Briefs), September 2007, page 30, and Autogen Version 2.0 (NPO- 41501), NASA Tech Briefs, Vol. 31, No. 10 (October 2007), page 58. To recapitulate: AutoGen (now signifying automatic sequence generation ) automates the generation of sequences of commands in a standard format for uplink to spacecraft. AutoGen requires fewer workers than are needed for older manual sequence-generation processes, and greatly reduces sequence-generation times. The sequences are embodied in spacecraft activity sequence files (SASFs). AutoGen automates generation of SASFs by use of another previously reported program called APGEN. AutoGen encodes knowledge of different mission phases and of how the resultant commands must differ among the phases. AutoGen also provides means for customizing sequences through use of configuration files. The approach followed in developing AutoGen has involved encoding the behaviors of a system into a model and encoding algorithms for context-sensitive customizations of the modeled behaviors. This version of AutoGen addressed the MRO (Mars Reconnaissance Orbiter) primary science phase (PSP) mission phase. On previous Mars missions this phase has more commonly been referred to as mapping phase. This version addressed the unique aspects of sequencing orbital operations and specifically the mission specific adaptation of orbital operations for MRO. This version also includes capabilities for MRO s role in Mars relay support for UHF relay communications with the MER rovers and the Phoenix lander.

  7. The seismic-stratigraphic record of lake-level fluctuations in Lake Challa: Hydrological stability and change in equatorial East Africa over the last 140 kyr

    NASA Astrophysics Data System (ADS)

    Moernaut, J.; Verschuren, D.; Charlet, F.; Kristen, I.; Fagot, M.; De Batist, M.

    2010-02-01

    Seismic-reflection data from crater lake Challa (Mt. Kilimanjaro, equatorial East Africa) reveal a ˜ 210-m thick sedimentary infill containing distinct seismic-stratigraphic signatures of late-Quaternary lake-level fluctuations. Extrapolation of a well-constrained age model on the cored upper part of the sequence suggests that these lake-level fluctuations represent a detailed and continuous record of moisture-balance variation in equatorial East Africa over the last 140 kyr. This record indicates that the most severe aridity occurred during peak Penultimate glaciation immediately before ˜ 128 kyr BP (coeval with Heinrich event 11) and during a Last Interglacial 'megadrought' period between ˜ 114 and ˜ 97 kyr BP; in comparison, Last Glacial Maximum (LGM) aridity was modest. It was preceded by ˜ 75 000 years of relatively stable and moist climate conditions interrupted by eleven short-lived dry spells, five of which match the timing of Heinrich events 2 to 6. Climate history near the East African equator reflects variation in the precessional forcing of monsoon rainfall modulated by orbital eccentricity, but precession-driven moisture fluctuations were less extreme than those observed in northern and southern tropical Africa. The near-continuous moist climate from ˜ 97 to 20.5 kyr BP recorded in the Lake Challa record contrasts with the trend towards greater aridity after ˜ 70 kyr BP documented in equatorial West Africa. This long period of moist glacial climate and a short, relatively modest LGM drought can be attributed to greater independence of western Indian Ocean monsoon dynamics from northern high-latitude glaciation than those in the tropical Atlantic Ocean. This rather persistent moist glacial climate regime may have helped maintain high biodiversity in the tropical forest ecosystems of the Eastern Arc mountains in Tanzania.

  8. Observation of 23 Supernovae that Exploded <300 pc from Earth During the Past 300 kyr in the Radiocarbon and 10Be Cosmogenic Isotope Record

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.

    2014-12-01

    The global excess radiocarbon abundance record for the past 50 kyr can be entirely explained by the explosion of four supernovae 44, 37, 32, and 22 kyr ago less than 250 pc from Earth. Each supernova left a nearly identical signature beginning with a sudden increase at the time of the explosion, followed by a hiatus of 1500 years, and continuing with a sustained, 2000 year increase in radiocarbon from gamma rays produced by diffusive shock in the supernova remnant. For the past 18 kyr excess radiocarbon from SN22kyrBP, identified as the Vela supernova, has decayed with the 5700 year half-life of 14C. The absolute scale for radiocarbon abundance has been determined from the decay curve as Δ14C=5±2% in 1950. Small oscillations in the decay curve are shown to coincide with variations in Earth's Virtual Axial Dipole Moment (VADM). SN44kyrBP exploded approximately 110 pc from Earth doubling the radiocarbon abundance. These supernovae are confirmed in the 10Be, 26Al, 36Cl and nitrate geological records. An additional 19 supernovae are observed 50-300 kyr ago in the 10Be record. Using the Earth as a calorimeter I have determined that approximated 2×1049 ergs were released at the time of each supernova explosion and 1049-50 ergs afterwards, consistent with theoretical predictions. The background rate of radiocarbon productions from more distant sources was determined as 1.61 atoms/cm2s at the top of the atmosphere. Although little danger to life on Earth is expected from these supernovae, each of the recent events were shown to correlate with concurrent global warming of 3-4°C.

  9. High Sedimentation Rate Paleomagnetic Records for the Last 70 kyrs From the Chilean Margin (ODP Sites 1233, 1234, 1235)

    NASA Astrophysics Data System (ADS)

    Stoner, J. S.; Lund, S.; Channell, J. E.; Mix, A. C.; Davies, M. H.; Lamy, F.

    2008-12-01

    Sediments that accumulate at around 1-m/kyr or greater preserve a paleomagnetic record that, under favorable conditions, may record the original geomagnetic input with little smoothing. However, such great rates of accumulation come with a price as features of interest are often deeply buried and may only be adequately recovered using drilling technologies. Here we present a full-vector geomagnetic reconstruction for the last 70,000 yrs from ultrahigh resolution records obtained through ODP drilling (Leg 202) on the Chilean Margin. ODP Site 1233 (41.0 S, 74.26 W, water depth 838 m) provides a 135-mcd u-channel derived directional paleomagnetic secular variation (PSV) and relative paleointensity (RPI) records. The chronology is constrained by AMS radiocarbon dates and tuning of alkenone sea surface temperature to Antarctic ice core temperature records back to 70,000 years BP. To the north, ODP Sites 1234 (36.13 S, 73.40W, water depth 1015 m) and 1235 (36.9 S, 73.33 W, water depth 489 m) provide independently dated shipboard and developing u-channel paleomagnetic records that reproduce many of the geomagnetic features observed at Site 1233 including excursions and high amplitude PSV intervals, while providing additional radiocarbon and isotopic constraints for development of a regional master chronology. All three Sites have exceptionally high glacial sedimentation rates that average 2-m/kyr for 1233, 80-cm/kyr for 1234 and 1-m/kyr for 1235. Fortuitously, the Laschamp magnetic excursion at Site 1233 occurs during an interval where sedimentation rates exceed 3-m/kyr. The Site 1233 chronology indicates that the Laschamp event, centered at 41,000 yrs BP, has a duration in reverse polarity of only 600 yrs, with polarity transitions occurring in less than 200 yrs within a 1500 yr long interval of low RPI. The path of virtual geomagnetic pole (VGP) positions for the Laschamp excursion at Site 1233 is generally consistent with the hypothesis of a simple field geometry

  10. Late Quaternary vegetation and environments in the Verkhoyansk Mountains region (NE Asia) reconstructed from a 50-kyr fossil pollen record from Lake Billyakh

    NASA Astrophysics Data System (ADS)

    Müller, Stefanie; Tarasov, Pavel E.; Andreev, Andrei A.; Tütken, Thomas; Gartz, Steffi; Diekmann, Bernhard

    2010-08-01

    Here we present a detailed radiocarbon-dated 936 cm long pollen record from Lake Billyakh (65°17'N, 126°47'E; 340 m a.s.l.) situated in the western part of the Verkhoyansk Mountains, about 140 km south of the Arctic Circle. A set of 53 surface pollen samples representing tundra, cold deciduous forest and taiga was collected in northern and central Yakutia communities to verify the accuracy of the quantitative biome reconstruction method and to obtain a more precise attribution of the identified pollen taxa to the main regional biomes. The adjusted method is then applied to the pollen record from Lake Billyakh to gain a reconstruction of vegetation and environments since about 50.7 kyr BP. The results of the pollen analysis and pollen-based biome reconstruction suggest that herbaceous tundra and steppe communities dominated the area from 50.7 to 13.5 kyr BP. Relatively low pollen concentrations and high percentages of herbaceous pollen taxa (mainly Cyperaceae, Poaceae and Artemisia) likely indicate a reduced vegetation cover and/or lower pollen production. On the other hand, extremely low percentages of drought-tolerant taxa, such as Chenopodiaceae and Ephedra, and the constant presence of various mesophyllous herbaceous ( Thalictrum, Rosaceae, Asteraceae) and shrubby taxa ( Betula sect. Nanae/Fruticosae, Duschekia fruticosa, Salix) in the pollen assemblages prevent an interpretation of the last glacial environments around Lake Billyakh as extremely arid. The lowest pollen percentages of woody taxa and the highest values of Artemisia pollen attest that the 31-15 kyr BP period as the driest and coldest interval of the entire record. A relative high content of taxa representing shrub tundra communities and the presence of larch pollen recorded prior to 31 kyr and after 13.5 kyr BP likely indicate interstadial climate amelioration associated with the middle and latest parts of the last glacial. An increase in pollen percentages of herbaceous taxa around 12 kyr BP

  11. Scenario Of The 4 kyr Extraterrestrial Impact : Crater Location, Ejecta-Dispersion and Consequences.

    NASA Astrophysics Data System (ADS)

    Courty, M.; Abbott, D. H.; Cortese, G.; Crisci, A.; Crosta, X.; de Wever, P.; Fedoroff, M.; Greenwood, P.; Grice, K.; Mermoux, M.; Scharer, U.; Smith, D. C.; Thiemens, M. H.

    2006-12-01

    The 4 kyr BP impact event has been identified from deep-sea, soil and archaeological records as the worldwide pulverisation of a volatile-rich debris jet(1). High resolution sequences show two stages of ejecta fallout linked to the impact-triggered doublet gaseous regime(2): scattered solid debris at the ground surface and spray of the vaporized hot fireball with thermal blast and local ignition. Ejecta debris consist of flow- textured impact glass, impact breccia and incompletely melted marine clasts: volcano-clastic sandy mudstone, calcareous mud, granite-gneiss, schists, volcanic breccia, kerogen and algal mud. Marine microfossils, organo-mineral markers, and the debris-fallout spatial pattern indicate two potential impact craters: an Antarctic source with an admixture of volcanic glass and ice rafted debris, from the vicinity of Heard Island and the Kerguelen plateau; a low latitude, shallow water one with hydrocarbons possibly from the Gulf of Mexico. Fine mixing of target materials from far distant source craters emphasizes a unique impact-ejecta. This matches the theoretical view of a debris jet channelled along the corridor cut through the atmosphere by the incoming projectile, raised upward, and dispersed widely(3). The isotopic anomaly of the sulphur phase in the kerogen volatile-component, indicating mass independent fractionation due to photolytic transformation, suggests launching at great heights, beyond the O2-O3 UV shield, responsible for climate disturbances. The incomplete melting of target rocks and global dispersion of impact breccia out of the craters would result from splash of small-sized projectile at rather great water depth and a low angle impact (10-15 degrees) into porous, highly compressible marine sediments. The spatially variable distribution of the organo-mineral and melt components, and the wide range of phase transformation reflect nonequilibrium shock-melting and micro-scale thermal processes in the heterogeneous vapor plume

  12. Does ice accretion temperature and geothernmal heating pace the change from ~40 kyr to ~100 kyr glacial cycles?

    NASA Astrophysics Data System (ADS)

    Buck, W. R.

    2008-12-01

    The growth and decay of ice sheets are clearly linked to cycles of the Earth's orbit, particularly the ~41 kyr obliquity cycle. Early Pleistocene ice ages appear to have grown and decayed on a timescale close to the obliquity period, while the period for late Pleistocene ice ages averages closer to 100 kyr. The thermal state of an ice sheet may control whether the climatic changes produced by orbital changes are can lead to the termination of an ice age. Numerous model studies indicate that the termination of ice ages requires glacial flow that is faster than expected for cold-based ice sheets. Fast flow likely requires that the base of the ice sheet be partially melted. Large ice sheets probably accrete cold, but geothermal heating can melt the base of an ice sheet if the surface of the ice is not too cold (as it may be in Antarctica) or if the accretion rate is not too high (as it may be in Greenland). The timescale for basal melting depends on the initial temperature structure of the ice sheet and on the rate of geothermal heating. For example the melting timescale depends on the square of the initial temperature of the ice sheet base. Although some workers assume parameters that give a melting timescale of less than 10 kyrs, reasonable values of ice temperature and terrestrial heatflow could give a timescale several times longer. One-dimensional numerical ice sheet flow models with a rate of ice accretion/ablation paced at 41 kyrs show a periodicity of the glacial cycles that depends on the period of basal melting. If the melting period is short (say <~30 kyrs) then the base of the ice sheet will be partially melted in time for the obliquity maximum that could produce a termination. The ice sheet then disappears at this first obliquity maximum after ice sheet initiation because it can flow fast enough to melt at lower latitudes and elevations. For longer basal melting periods the entire ice sheet may not be warm enough to flow fast enough to lead to termination

  13. Human Exploration of Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.

    2010-01-01

    This paper provides a summary of the Mars Design Reference Architecture 5.0 (DRA 5.0), which is the latest in a series of NASA Mars reference missions. It provides a vision of one potential approach to human Mars exploration. The reference architecture provides a common framework for future planning of systems concepts, technology development, and operational testing as well as Mars robotic missions, research that is conducted on the International Space Station, and future lunar exploration missions. This summary the Mars DRA 5.0 provides an overview of the overall mission approach, surface strategy and exploration goals, as well as the key systems and challenges for the first three human missions to Mars.

  14. Human Exploration of Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.; Hoffman, Stephen J.; Beaty, David W.

    2009-01-01

    This paper provides a summary of the 2007 Mars Design Reference Architecture 5.0 (DRA 5.0), which is the latest in a series of NASA Mars reference missions. It provides a vision of one potential approach to human Mars exploration including how Constellation systems can be used. The reference architecture provides a common framework for future planning of systems concepts, technology development, and operational testing as well as Mars robotic missions, research that is conducted on the International Space Station, and future lunar exploration missions. This summary the Mars DRA 5.0 provides an overview of the overall mission approach, surface strategy and exploration goals, as well as the key systems and challenges for the first three human missions to Mars.

  15. Multi-proxy sedimentary record from Lake Ghirla (N-Italy) reveals hydro-climatic variations and periods of anthropogenic activities during the past 13 kyrs

    NASA Astrophysics Data System (ADS)

    Wirth, Stefanie B.; Gilli, Adrian; Sessions, Alex L.

    2016-04-01

    Lake Ghirla is a small lake that lies in the southern foothills of the Central Alps near the Swiss-Italian border. Climatically, the region is influenced by North Atlantic and Mediterranean weather systems and is frequently affected by severe storm tracks causing heavy precipitation. The catchment with Permian granites and gneisses contains Pb in amounts significant for mining as well as less important concentrations of Cu, As and U. This sensitive setting makes Lake Ghirla a promising site to reconstruct hydro-climatic variations and to track human activity by means of elevated heavy metal concentrations in the lake sediments. The recovered sediment core comprises the entire Younger Dryas-Holocene time period and was analyzed for (i) sedimentological changes to identify flood deposits, for (ii) the hydrogen isotopic composition of terrestrial plant waxes (plant-wax D/H) to constrain hydro-climatic changes, and for (iii) variations of the elemental composition (XRF core scanning, ICP-MS) to understand anthropogenic impacts. During the past 13 kyrs, we observe a high variability of floods with peak periods appearing at ~11, 10.6-8.2, 6-4.9, 2.8-2.7, 2.6-2.4, 1.2-1 and 0.4-0.1 (LIA) cal kyr BP. From a hydro-climatic perspective, the most remarkable result from the plant-wax D/H data is that the Younger Dryas is characterized by no significant change and that the 2.8-2.7 kyr BP and LIA intervals show an increase of plant-wax D/H values. Hence, during these three cool climatic periods temperature effects cannot be solely responsible for plant-wax D/H variation. The southward migration of the westerly storm tracks above the North Atlantic due to climate cooling must have led to a more southern and thus isotopically enriched moisture source for the southern Alps. This moisture-source change likely counter-balanced or even over-rode the temperature-driven isotope effect. Increased sedimentary Cu concentrations at 3.8-3.3 kyr BP are the first evidence for the presence of

  16. The Sima de los Huesos hominids date to beyond U/Th equilibrium (>350 kyr) and perhaps to 400-500 kyr: New radiometric dates

    USGS Publications Warehouse

    Bischoff, J.L.; Shamp, D.D.; Aramburu, Arantza; Arsuaga, J.L.; Carbonell, E.; Bermudez de Castro, Jose Maria

    2003-01-01

    The Sima de los Huesos site of the Atapuerca complex near Burgos, Spain contains the skeletal remains of at least 28 individuals in a mud breccia underlying an accumulation of the Middle Pleistocene cave bear (U. deningeri). Earlier dating estimates of 200 to 320 kyr were based on U-series and ESR methods applied to bones, made inaccurate by unquantifiable uranium cycling. We report here on a new discovery within the Sima de los Huesos of human bones stratigraphically underlying an in situ speleothem. U-series analyses of the speleothem shows the lower part to be at isotopic U/Th equilibrium, translating to a firm lower limit of 350 kyr for the SH hominids. Finite dates on the upper part suggest a speleothem growth rate of c. 1 cm/32 kyr. This rate, along with paleontological constraints, place the likely age of the hominids in the interval of 400 to 600 kyr. ?? 2002 Elsevier Science Ltd. All rights reserved.

  17. Late Neogene East Asian monsoon: from winter to summer dominated sub-regime and periodicity transition from 100 kyr to 41 kyr

    NASA Astrophysics Data System (ADS)

    Li, F.; Rousseau, D.-D.; Wu, N.; Hao, Q.; Pei, Y.

    2009-04-01

    More and more evidence indicates that the onset of the East Asian (EA) monsoon can be traced back to the Oligocene-Miocene boundary (at about 23 Ma). However, the process of its evolution is still less well known until now. Here we investigate its late Neogene evolution by analyzing a terrestrial mollusk sequence, from the Chinese Loess Plateau (CLP), covering the period between 7.1 and 3.5 Ma. Considering the modern ecological requirements of these organisms, we were able to define two groups of cold-aridiphilous (CA) and thermo-humidiphilous (TH) species, representing the EA winter and summer monsoon variations, respectively, as previously defined in the Quaternary glacial-interglacial cycles. Variations in these two groups indicate two different monsoon dominated periods during 7.1-3.5 Ma. First, between 7.1 and 5.5 Ma, the EA winter monsoon, with a 100 kyr periodicity, was dominant. Second, between 5.1 and 4 Ma, the EA summer monsoon dominated, with a 41 kyr periodicity. Furthermore, our mollusk record yields valuable evidence for a late Miocene-Pliocene transition of about 400 kyr from winter monsoon dominated towards summer monsoon dominated, associated with a periodicity transition from weak 100 kyr to 41 kyr. The strengthened winter monsoon interval, with a 100 kyr periodicity, is coeval with orbital-scale global ice volume changes, in conjunction with the uplift of the Tibetan Plateau which probably reinforced the winter monsoon sub-regime. Conversely, closures of the Panama and Indonesian seaways, associated with changes in obliquity between 5.1 and 4 Ma, are probably major forcing factors for the observed dominant summer monsoon with 41 kyr frequency, favoring heat and moisture transports between low and high latitudes to allow TH mollusks to grow and develop in the CLP. The transition from a 100 kyr dominated interval towards a 41 kyr dominated one is contrary to the mid-Pleistocene transition (MPT), which corresponds to ice volume expansion at high

  18. Latitudinal Hydrologic Variability Along the East African Rift, Over the Past 200 Kyr

    NASA Astrophysics Data System (ADS)

    Scholz, C. A.

    2014-12-01

    Within the deep sediments of the large lakes of Africa's Great Rift Valley are continuous environmental records of remarkable antiquity and fidelity. Not only do stratigraphic sections from these basins extend back millions of years, many of the intervals represented contain high-resolution material of decadal resolution or better. East African lake basins remain sparsely sampled however, with only a few long and continuous records available. Our ability to image the lakes using seismic reflection methods greatly exceeds our opportunities for coring and drilling however; assessing stratal relationships observed in the geophysical data permits powerful inferences about past hydrologic changes. With intensive hydrocarbon exploration work underway in East Africa, industry well data can also help constrain and ground truth basin histories. Substantial spatio-temporal hydrologic variability is observed in East African basins over the past 200 kyr. Paleohydrological changes in the late Pleistocene and early Holocene are now well constrained in the northern hemisphere East African topics, with widespread aridity and in some cases lake desiccation observed during Heinrich Event 1. A climate recovery followed in the northern hemisphere East African tropics, with the early Holocene African Humid Period a time of positive water balance across most of the rift valley. The paleohydrology of southern hemisphere tropical East Africa is more equivocal, for instance with negligible draw-down of Lake Malawi at HE1. Whereas these late Pleistocene events represent substantial climate reorganizations, severe droughts during the middle-late Pleistocene (150-65 kyr BP) were far more intense, and produced much more severe drawdowns of Lakes Malawi and Tanganyika. Scientific drill cores, kullenberg cores, and extensive seismic reflection data sets from Lakes Malawi and Tanganyika provide indisputable evidence for lowstands of -500m and -600 m respectively. Climate changes that lowered the

  19. Quantitative woody cover reconstructions from eastern continental Asia of the last 22 kyr reveal strong regional peculiarities

    NASA Astrophysics Data System (ADS)

    Tian, Fang; Cao, Xianyong; Dallmeyer, Anne; Ni, Jian; Zhao, Yan; Wang, Yongbo; Herzschuh, Ulrike

    2016-04-01

    We present a calibration-set based on modern pollen and satellite-based Advanced Very High Resolution Radiometer (AVHRR) observations of woody cover (including needleleaved, broadleaved and total tree cover) in eastern continental Asia, which shows good performance under cross-validation with the modern analogue technique (all the coefficients of determination between observed and predicted values are greater than 0.65). The calibration-set is used to reconstruct woody cover from a taxonomically harmonized and temporally standardized fossil pollen dataset (including 274 cores) with 500-year resolution over the last 22 kyr. The spatial range of forest has not noticeably changed in eastern continental Asia during the last 22 kyr, although woody cover has, especially at the margin of the eastern Tibetan Plateau and in the forest-steppe transition area of north-central China. Vegetation was sparse during the LGM in the present forested regions, but woody cover increased markedly at the beginning of the Bølling/Allerød period (B/A; ca. 14.5 ka BP) and again at the beginning of the Holocene (ca. 11.5 ka BP), and is related to the enhanced strength of the East Asian Summer Monsoon. Forest flourished in the mid-Holocene (ca. 8 ka BP) possibly due to favourable climatic conditions. In contrast, cover was stable in southern China (high cover) and arid central Asia (very low cover) throughout the investigated period. Forest cover increased in the north-eastern part of China during the Holocene. Comparisons of these regional pollen-based results with simulated forest cover from runs of a global climate model (for 9, 6 and 0 ka BP (ECHAM5/JSBACH ∼1.125° spatial resolution)) reveal many similarities in temporal change. The Holocene woody cover history of eastern continental Asia is different from that of other regions, likely controlled by different climatic variables, i.e. moisture in eastern continental Asia; temperature in northern Eurasia and North America.

  20. Mars Design Reference Architecture 5.0 Study: Executive Summary

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.

    2008-01-01

    The NASA Mars Design Reference Architecture 5.0 Study seeks to update its long term goals and objective for human exploration missions; flight and surface systems for human missions and supporting infrastructure; operational concept for human and robotic exploration of Mars; key challenges including risk and cost drivers; and, its development schedule options. It additionally seeks to assess strategic linkages between lunar and Mars strategies and develop and understanding of methods for reducing the cost/risk of human Mars missions through investment in research, technology development, and synergy with other exploration plans. Recommendations are made regarding conjunction class (long-stay) missions which are seen as providing the best balance of cost, risk, and performance. Additionally, this study reviews entry, descent, and landing challenges; in-space transportation systems; launch vehicle and Orion assessments; risk and risk mitigation; key driving requirements and challenges; and, lunar linkages.

  1. The U5. 0 Undulator for the ALS

    SciTech Connect

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1991-05-01

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed and is in fabrication. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) and is scheduled for completion in 1992. A modular hybrid configuration utilizing Nd-Fe-B permanent magnet material and vanadium permendur is used that achieves 0.837 Tesla effective peak field. Correction of the vertical field integral is with permanent magnet rotors at the ends. Gap adjustment is with an arrangement of roller screws, chains drives, a gear reduction unit and a stepper motor driven by a closed loop control system. The vacuum chamber design is a two-piece, machined and welded 5083-H321 aluminum construction of 5.1 m length. Magnetic design, subsystem design and fabrication progress are presented. 12 refs., 4 figs., 2 tabs.

  2. Nuclear waste glass product consistency test (PCT), Version 5. 0

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

  3. Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

    NASA Astrophysics Data System (ADS)

    Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

    2010-05-01

    Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

  4. Dome collapse eruption in Tatun Volcanic Group near metropolitan Taipei, Taiwan at ~6 kyrs

    NASA Astrophysics Data System (ADS)

    Chen, C.; Lee, T.

    2010-12-01

    The Tatun Volcanic Group (TVG) is located in the north of metropolitan Taipei, Taiwan. Over 6 million inhabitants are living in Taipei City and suburban area. Another critical issue is an international airport and two nuclear power plants are lying at the foot of the TVG. If the TGV will be re-active, the serious hazard for human lives and economies in this area will definitely occur. Understanding the youngest eruption history of the TVG will be much important for prediction the future activity of eruption. The core was collected from the Dream Lake at the eastern slop of Cising Mt.. Total 21 samples from depth 190 cm to 231.5 cm have been tested. Comparison of chemical compositions of glass and minerals in the volcanic clasts with those of lava around TVG, they clearly showed that the volcanic clasts can be correlated with the eruption of the closest Cising Mt. According to the radiocarbon (C-14) age of core sample at the depth 225 cm, the age was extrapolated around 6150 yrs ca. C-14 B.P.. Moreover, the respiratory cristobalite in the volcanic clasts were firstly identified by the identical morphology, chemical composition and Laser Raman Spectrometry (LRS). The crystalline silica was produced by vapor-phase crystallization and devitrification in the andesite lava dome and volcanic ash generated by pyroclastic flows formed by lava dome collapse in Soufriere Hills volcano, Montserrat (Baxter et al.,1999). These new evidence demonstrated that there would probably have the lava dome collapse eruptions in the TVG in the last 6 kyrs. The result in this paper also sustained that the landslide caused by the weak phreatic eruption within the last 6000 yrs in the TVG (Belousov et al., 2010). It must further be noted that an efficient program of the volcanic hazard reduction should be practiced for the metropolitan Taipei and suburban area.

  5. Frequency variations of the earth's obliquity and the 100-kyr ice-age cycles

    NASA Technical Reports Server (NTRS)

    Liu, Han-Shou

    1992-01-01

    Changes in the earth's climate are induced by variations in the earth's orbital parameters which modulate the seasonal distribution of solar radiation. Periodicities in the geological climate record with cycles of 100, 41, and 23 kyr have been linked with changes in obliquity, eccentricity, and precession of the equinoxes. The effect of variations of eccentricity during a 100 kyr period is weak relative to the signals from obliquity and precession variations and it may therefore be expected that the 100 kyr signal in the climate record would be of low intensity. However, this signal dominates the climate record and internal nonlinear processes within the climate system have previously been proposed to account for this fact. The author shows that variations in the frequency of the obliquity cycle can give rise to strong 100-kyr forcing of climate.

  6. Multi Platform Trusted Copy (MPTC) V 5.0

    2005-03-01

    MPTC 5.0 reviews text files; Microsoft (MS) Word, PowerPoint, and Excel in the MS Office 2000, XP, and 2003 formats; MS Access in the XP and 2003 formats; and dxf CAD files for keywords supplied by the reviewer. Keywords are specified in a keyword file or entered via the GUI at review time so that each document review can be customized. In addition, MPTC detects embedded objects and removes Microsoft-documented metadata from the supported MSmore » Office file formats. After each review, a user can examine the review log for MPTC's findings. A file can be opened with its creating application from within MPTC for visual review and resolution of review failures. If MPTC pases the file file or the reviewer has resolved review failures, the reviewer can transfer the file to an unclassified, removable medium with the following caveats: MPTC prohibits the transfer of any file containing a hidden data stream. Compressed files and file archives cannot be transferred without first uncompressing or extracting the files. MPTC provides a detection mechanism for Java-based intelligent agents and rudimentary steganography detection capability. MPTC ensures that only the designated files are copied, moved, or deleted and confirms each operation after completion. MPTC records all transactions and user logon identities in encrypted review, transfer, and session log files. MPTC compiles with the DOE/NNSA two-person rule by requiring that the names of two reviewers be enetered prior to file transfer. The MPTC code is designed to accommodate additional review tools to enhance the effectiveness of the Authorized Derivative Classifier (ADC) or other authorized user and reduce the security risks associated with file transfers. Cross-plaform: Runs on Windows 2000, Windows XP, Red Hat Enterprise Linux Workstation, Fedora Core 2 and 3, Red Hat Linux 9, Solaris 8, and Solaris 9.« less

  7. Multi Platform Trusted Copy (MPTC) V 5.0

    SciTech Connect

    Bintz, Karen; Michelsen, Rebecca; Lyon, Stephanie; Schear, Nabil

    2005-03-01

    MPTC 5.0 reviews text files; Microsoft (MS) Word, PowerPoint, and Excel in the MS Office 2000, XP, and 2003 formats; MS Access in the XP and 2003 formats; and dxf CAD files for keywords supplied by the reviewer. Keywords are specified in a keyword file or entered via the GUI at review time so that each document review can be customized. In addition, MPTC detects embedded objects and removes Microsoft-documented metadata from the supported MS Office file formats. After each review, a user can examine the review log for MPTC's findings. A file can be opened with its creating application from within MPTC for visual review and resolution of review failures. If MPTC pases the file file or the reviewer has resolved review failures, the reviewer can transfer the file to an unclassified, removable medium with the following caveats: MPTC prohibits the transfer of any file containing a hidden data stream. Compressed files and file archives cannot be transferred without first uncompressing or extracting the files. MPTC provides a detection mechanism for Java-based intelligent agents and rudimentary steganography detection capability. MPTC ensures that only the designated files are copied, moved, or deleted and confirms each operation after completion. MPTC records all transactions and user logon identities in encrypted review, transfer, and session log files. MPTC compiles with the DOE/NNSA two-person rule by requiring that the names of two reviewers be enetered prior to file transfer. The MPTC code is designed to accommodate additional review tools to enhance the effectiveness of the Authorized Derivative Classifier (ADC) or other authorized user and reduce the security risks associated with file transfers. Cross-plaform: Runs on Windows 2000, Windows XP, Red Hat Enterprise Linux Workstation, Fedora Core 2 and 3, Red Hat Linux 9, Solaris 8, and Solaris 9.

  8. The U5. 0 Undulator for the Advanced Light Source

    SciTech Connect

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D. )

    1992-01-01

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated, and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1,500 eV range, for the Advanced Light Source at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd--Fe--B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of five assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 T effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni--Fe hinges. The magnetic structure is connected through four rollernuts to the drive system that provides gap adjustment with an arrangement of roller screws, chain drives, a gear reduction unit, and a stepper motor driven by a closed loop control system. Magnetic structure and drive system support are from a 2.4 m high structure which includes a support base with four vertical supports. The vacuum chamber design is a two-piece machined and welded 5083-H321 aluminum construction of 5.1 m length. Pumping is with a combination of ion, titanium sublimation pump and nonevaporable getter pumps. Magnetic design, subsystem design, and fabrication progress are presented.

  9. The U5. 0 Undulator for the ALS

    SciTech Connect

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1991-07-15

    the U5.0 Undulator, and 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd-Fe-B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of 5 assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 Tesla effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni-Fe hinges. The magnetic structure is connected through four roller-nuts to the drive system that provides gap adjustment with an arrangement of roller screws, chain drives, a gear reduction unit and a stepper motor driven by a closed loop control system. Magnetic structure and drive system support are from a 2.4 m high structure which includes a support base with four vertical supports. The vacuum chamber design is a two-piece machined and welded 5083-H321 aluminum construction of 5.1 m length. Pumping is with a combination of ion, TSP and NEG pumps. Magnetic design, subsystem design and fabrication progress are presented.

  10. Sea surface and subsurface circulation dynamics off equatorial Peru during the last ~17 kyr

    NASA Astrophysics Data System (ADS)

    Nürnberg, Dirk; Böschen, Tebke; Doering, Kristin; Mollier-Vogel, Elfi; Raddatz, Jacek; Schneider, Ralph

    2015-07-01

    The complex deglacial to Holocene oceanographic development in the Gulf of Guayaquil (Eastern Equatorial Pacific) is reconstructed for sea surface and subsurface ocean levels from (isotope) geochemical proxies based on marine sediment cores. At sea surface, southern sourced Cold Coastal Water and tropical Equatorial Surface Water/Tropical Surface Water are intimately related. In particular since ~10 ka, independent sea surface temperature proxies capturing different seasons emphasize the growing seasonal contrast in the Gulf of Guayaquil, which is in contrast to ocean areas further offshore. Cold Coastal Water became rapidly present in the Gulf of Guayaquil during the austral winter season in line with the strengthening of the Southeast Trades, while coastal upwelling off Peru gradually intensified and expanded northward in response to a seasonally changing atmospheric circulation pattern affecting the core locations intensively since 4 ka BP. Equatorial Surface Water, instead, was displaced and Tropical Surface Water moved northward together with the Equatorial Front. At subsurface, the presence of Equatorial Under Current-sourced Equatorial Subsurface Water was continuously growing, prominently since ~10-8 ka B.P. During Heinrich Stadial 1 and large parts of the Bølling/Allerød, and similarly during short Holocene time intervals at ~5.1-4 ka B.P. and ~1.5-0.5 ka B.P., the admixture of Equatorial Subsurface Water was reduced in response to both short-term weakening of Equatorial Under Current strength from the northwest and emplacement by tropical Equatorial Surface Water, considerably warming the uppermost ocean layers.

  11. Nd isotopic composition from seawater and sediments of the South China Sea and the Philippine Sea : implications for hydrology of the Pacific Ocean during the last 25 kyr

    NASA Astrophysics Data System (ADS)

    Wu, Qiong; Colin, Christophe; Liu, Zhifei; Thil, Francois; Douville, Eric; Frank, Norbert

    2014-05-01

    Nd isotopic compositions (ɛNd) of foraminifera from one gravity core (MD05-2904; 19°27.32' 116°15.15', 2066 m water depth) and 10 seawater profiles from the northern South China Sea (SCS) and the Philippine Sea (western Pacific Ocean) were measured to (1) constrain the Nd isotopic composition of water masses along the western Pacific and the SCS that are still poorly documented ; (2) track hydrological exchange between the SCS and western Pacific trough the Luzon strait ; (3) to test the ability of foraminifera to establish seawater ɛNd ; (4) to establish past hydrological changes of deep-water circulation in the western Pacific Ocean during the last 25 kyr. Distribution of ɛNd seawater of the Northern SCS and west Pacific indicate that the SCS is dominated by three water masses, the South China Sea Tropical Water (SCSTW) (~-7.7), South China Sea Intermediate Water (SCSIW) (~-3.6) and the Pacific Deep Water (PDW) (~-4). Our results indicate that at present time ɛNd of deep and intermediate waters of the SCS is representative of the PDW. Different analytical procedures to extract seawater ɛNd from foraminiferas (benthic and planktonic) and Fe-Mn coatings precipitated on the sediments have been tested and permit to determine that only ɛNd obtained from foraminiferas are reliable to seawater ɛNd in the South China Sea. A first record of past seawater ɛNd obtained from foraminifera of the core MD05-2904 (northern part of the SCS) indicate major change of the hydrology of the West Pacific during the last 25 kyr. ɛNd values variations indicate two negative excursion during at Heinrich Stadial 1(~16 kyr BP) and ~10 kyr BP implying a reorganization of the deep circulation in the Pacific. Such results are compared with other proxies of deep-water circulation to propose new insight in the role of the southern deep-water pacific circulation on climate during the last deglaciation.

  12. Elevated BP after AKI.

    PubMed

    Hsu, Chi-Yuan; Hsu, Raymond K; Yang, Jingrong; Ordonez, Juan D; Zheng, Sijie; Go, Alan S

    2016-03-01

    The connection between AKI and BP elevation is unclear. We conducted a retrospective cohort study to evaluate whether AKI in the hospital is independently associated with BP elevation during the first 2 years after discharge among previously normotensive adults. We studied adult members of Kaiser Permanente Northern California, a large integrated health care delivery system, who were hospitalized between 2008 and 2011, had available preadmission serum creatinine and BP measures, and were not known to be hypertensive or have BP>140/90 mmHg. Among 43,611 eligible patients, 2451 experienced AKI defined using observed changes in serum creatinine concentration measured during hospitalization. Survivors of AKI were more likely than those without AKI to have elevated BP-defined as documented BP>140/90 mmHg measured during an ambulatory, nonemergency department visit-during follow-up (46.1% versus 41.2% at 730 days; P<0.001). This difference was evident within the first 180 days (30.6% versus 23.1%; P<0.001). In multivariable models, AKI was independently associated with a 22% (95% confidence interval, 12% to 33%) increase in the odds of developing elevated BP during follow-up, with higher adjusted odds with more severe AKI. Results were similar in sensitivity analyses when elevated BP was defined as having at least two BP readings of >140/90 mmHg or those with evidence of CKD were excluded. We conclude that AKI is an independent risk factor for subsequent development of elevated BP. Preventing AKI during a hospitalization may have clinical and public health benefits beyond the immediate hospitalization. PMID:26134154

  13. Reconstruction of the Surface Temperature Change in Central Greenland During D/O 12, 45 Kyr B.P.

    NASA Astrophysics Data System (ADS)

    Caillon, N.; Jouzel, J.; Chappellaz, J.

    2001-12-01

    Air bubbles preserved in polar ice cores are unique archives of past atmospheric composition. Recently, it has been shown that air bubbles isotopic composition (N-15, Ar-40) enables to quantify past abrupt changes in polar regions. In this study, a high resolution measurement of nitrogen and argon isotopes in an ice core from Greenland allows to determine past surface temperature variations and the ice age-gas age difference during the Dansgaard-Oeschger event 12 recorded around 45,000 years before present. These results imply a mean surface temperature change of 8.2 +/- 0.8 ° C and permit to determine a δ 18Oice-temperature coefficient of 0.54 +/- 0.05 ‰ /° C and therefore bring a new constraint to calibrate the isotopic paleothermometer during glacial period. Moreover, a direct comparison with methane concentration will be presented to discuss the phase relationship between the warming and the methane increase.

  14. Stalagmite Survival: 500kyr of Cyclical Growth and Natural Attrition of Stalagmites in Sulawesi

    NASA Astrophysics Data System (ADS)

    Scroxton, N.; Gagan, M. K.; Dunbar, G. B.; Ayliffe, L. K.; Hantoro, W. S.; Shen, C. C.; Hellstrom, J. C.; Zhao, J. X.; Cheng, H.; Edwards, R. L.; Sun, H.; Rifai, H.

    2014-12-01

    Numerous speleothem studies have analysed the age distribution of stalagmites harvested from multiple caves and inferred important changes in paleoclimates to explain stalagmite growth phases. However, stalagmites take tens to hundreds of thousands of years to grow, and thus the twin desires to preserve the cave condition for future generations and advance palaeoclimate science are often in conflict. In this study we use U/Th ages from low impact mini-cores extracted in situ from the bases of stalagmites, thus keeping the intrinsic value of the cave intact. Our case study is based on 77 individual stalagmites drilled in situ in thirteen caves located in and around Bantimurung-Bulusaraung National Park, South Sulawesi, Indonesia. The stalagmites grew during discrete time intervals within the last ~530,000 years, and analysis of their age distribution shows an exponential decrease in the number of older stalagmites surviving to the present day. The age distribution indicates that the rate of natural attrition of stalagmites is approximately constant through time, probably in response to a number of natural processes, including downward erosion of the karst terrain, cave collapse, in-cave erosional processes and in-cave sedimentation covering stalagmites. Natural attrition of stalagmites is likely to be a general cave phenomenon, and has important implications for cave conservation because it highlights that random removal of stalagmites without prior knowledge of their ages will result in unnecessary replication and a failure to sample the full length of the available paleoclimate record. Departure from this "normal" exponential profile can be used to infer palaeoclimate information: significant deviations are produced by periods of more frequent stalagmite growth, inferred here to reflect increases in monsoon rainfall over Sulawesi (345-340, 75-70 and 10-5 kyr BP). By adjusting the record to account for stalagmite attrition, more statistically robust paleoclimate

  15. Teasing Apart Regional Climate and Meltwater Influences on Florida Straits Sea Surface Temperature and Salinity over the past 40 kyr

    NASA Astrophysics Data System (ADS)

    Schmidt, M. W.; Lynch-Stieglitz, J.

    2008-12-01

    when elevated meltwater discharge was the dominant influence on surface water conditions in the Florida Straits. It is likely that SSS in the Florida Straits was significantly fresher than today during this interval. In contrast, periods of minimal meltwater influence (such as the Younger Dryas and across D-O cycles of MIS 3) are characterized by abrupt SST and SSS shifts that covary with the NGRIP δ18Oice record. SSTs in the Florida Straits cool by 1.5-2.0 °C and regional salinity increases (IVF-δ18OSW increase of 0.5-0.7‰) at the initiation of cold stadial events as the ITCZ shifts south. The most likely explanation for these rapid shifts in IVF-δ18OSW values is that moisture transport out of the North Atlantic increases when the North Atlantic cools and the ITCZ shifts southward.

  16. An 84-kyr paleomagnetic record from the sediments of Lake Baikal, Siberia

    USGS Publications Warehouse

    Peck, J.A.; King, J.W.; Colman, Steven M.; Kravchinsky, V.A.

    1996-01-01

    We have conducted a paleomagnetic study of sediment cores obtained from the Selenga prodelta region of Lake Baikal, Russia. This record, which spans approximately the last 84 kyr, contributes to a better understanding of the nature of geomagnetic field behavior in Siberia and is a useful correlation and dating tool. We demonstrate that the Lake Baikal sediments are recording variations in the geomagnetic field. The directional record displays secular variation behavior with a geomagnetic excursion at 20 ka and additional excursions appearing as large-amplitude secular variation at 41, 61, and 67 ka. Smoothing of the geomagnetic excursion behavior occurs in Lake Baikal sediments owing to the intermediate sedimentation rate (13 cm kyr-1). The Lake Baikal relative paleointensity record correlates to absolute paleointensity data for the last 10 kyr and to relative paleointensity records from the Mediterranean Sea and Indian Ocean for the last 84 kyr. This correlation suggests a strong global (i.e., dipole) component to these records and further supports the reliability of sediments as recorders of relative geomagnetic paleointensity. We show that a relative geomagnetic intensity stratigraphy has a potential resolution of 7 kyr by correlating continental and marine records. The geomagnetic intensity stratigraphy helps constrain the age of the difficult to date Lake Baikal sediments.

  17. The bioavailable iron in NEEM ice core related to Asian dust records over the past 110 kyr

    NASA Astrophysics Data System (ADS)

    Xiao, Cunde

    2016-04-01

    The mineral dust can indirectly affect climate by supplying iron and other essential bioavailable elements into ocean. In this study, we present dissolved iron (DFe) and total dissolved iron (TDFe) concentrations in NEEM ice core over the past 110 kyr B.P. The concentrations of bioavailable reactive element Fe have good positive correlation with the concentrations of dust and Ca2+ in NEEM ice core, while show significantly negative relationship with δ18O and CO2 concentration. The ratios of DFe/TDFe are higher in warm periods (Holocene and last interglacial) than in cold period (LGM), indicating the iron-biological pump effect is more significant in warm periods than that in cold periods, this result may provide a new insight for reevaluating the iron hypothesis over glacial/interglacial periods. Our study also shows that the iron flux changes between NEEM ice core and Asian loess records are good consistent with the northern Hemisphere summer insolation. These results emphasize that the variability of Fe flux is most likely driven by solar radiation and dust in northern hemisphere.

  18. 78 FR 60270 - BP America Inc., BP Corporation North America Inc., BP America Production Company, and BP Energy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission BP America Inc., BP Corporation North America Inc., BP America Production Company, and BP Energy Company; Notice of Designation of Commission Staff as Non-Decisional With...

  19. Late Quaternary evolution of Lago Castor (Chile, 45.6°S): Timing of the deglaciation in northern Patagonia and evolution of the southern westerlies during the last 17 kyr

    NASA Astrophysics Data System (ADS)

    Van Daele, Maarten; Bertrand, Sébastien; Meyer, Inka; Moernaut, Jasper; Vandoorne, Willem; Siani, Giuseppe; Tanghe, Niels; Ghazoui, Zakaria; Pino, Mario; Urrutia, Roberto; De Batist, Marc

    2016-02-01

    Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ˜28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained - possibly through an outburst flood - when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ˜20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ˜17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase in

  20. Late Quaternary evolution of Lago Castor (Chile, 45.6°S): Timing of the deglaciation in northern Patagonia and evolution of the southern westerlies during the last 17 kyr

    NASA Astrophysics Data System (ADS)

    Van Daele, Maarten; Bertrand, Sébastien; Meyer, Inka; Moernaut, Jasper; Vandoorne, Willem; Siani, Giuseppe; Tanghe, Niels; Ghazoui, Zakaria; Pino, Mario; Urrutia, Roberto; De Batist, Marc

    2016-02-01

    Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ∼28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained - possibly through an outburst flood - when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ∼20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ∼17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase

  1. Blood pressure (BP) assessment-from BP level to BP variability.

    PubMed

    Feber, Janusz; Litwin, Mieczyslaw

    2016-07-01

    The assessment of blood pressure (BP) can be challenging in children, especially in very young individuals, due to their variable body size and lack of cooperation. In the absence of data relating BP with cardiovascular outcomes in children, there is a need to convert absolute BP values (in mmHg) into age-, gender- and height appropriate BP percentiles or Z-scores in order to compare a patient's BP with the BP of healthy children of the same age, but also of children of different ages. Traditionally, the interpretation of BP has been based mainly on the assessment of the BP level obtained by office, home or 24-h BP monitoring. Recent studies suggest that it is not only BP level (i.e. average BP) but also BP variability that is clinically important for the development of target organ damage, including the progression of chronic kidney disease. In this review we describe current methods to evaluate of BP level, outline available methods for BP variability assessment and discuss the clinical consequences of BP variability, including its potential role in the management of hypertension. PMID:26201477

  2. Investigating the Impacts of Climate, Hydrology, and Asian Monsoon Intensity on a 13 kyr Speleothem Record from Laos

    NASA Astrophysics Data System (ADS)

    Yang, Hongying

    I present a high- resolution record of Southeast Asian Monsoon (SEAM) evolution compiled from delta18O measurements conducted on five U-Th dated speleothems from Tham Mai Cave in northern Laos (20.75N, 102.65E), a key site at the interface between the Indian and East Asian monsoon systems. The speleothem oxygen isotope records are tied to robust uranium-series dates and indicate the records span from 0.79 to 13 kyr BP with sub-decadal resolution. During the Holocene, the Tham Mai speleothem delta18O records are characterized by lower values during the early to mid-Holocene with increasing values towards the late Holocene. This is similar to trends seen throughout the Asian monsoon region, reflecting the strong insolation control on monsoon strength and ITCZ position. The Younger Dryas is characterized by an abrupt delta 18O increase and is synchronous with the even observed in Chinese speleothem records and Greenland ice cores within age uncertainties. This suggests that the SEAM weakened in sync with high-latitude abrupt cooling events. Four speleothems from Tham Mai cave grew contemporaneously from 4,300 years BP to 9,000 years BP. These four samples show a similar delta 18O pattern, despite a 1.2‰ between sample delta18 O variability is observed. A lumped parameter forward model method (KarstFor model) is used to assess to which extent this 1.2‰ discrepancy can be attributed to hydrological variability. Results suggested that this 1.2‰ discrepancy can be generated due to hydrological variability within one cave. To better interpret interannual delta18O variability in high-resolution oxygen isotope records in the Asian Monsoon region, I utilize existing simulations from a spectrally nudged isotope-enabled general circulation model (IsoGSM) to investigate the climatic controls on delta18 Op at four cave locations along the Asian monsoon region. Results show that delta18Op at the four cave sites reflects large-scale ocean-atmosphere processes, instead of

  3. Mesozoic cyclostratigraphy, the 405-kyr orbital eccentricity metronome, and the Astronomical Time Scale (Invited)

    NASA Astrophysics Data System (ADS)

    Hinnov, L.; Ogg, J. G.

    2009-12-01

    Mesozoic cyclostratigraphy from around the world is being assessed to construct a continuous Astronomical Time Scale (ATS) based on Earth’s cyclic orbital parameters. The recognition of a prevalent sedimentary cycling with a ~400-kyr period associated with forcing by the stable 405-kyr orbital eccentricity variation is an important development. Numerous formations spanning 10 to 20 myr (and longer) intervals in the Cretaceous, Jurassic and Triassic clearly express this dominant cycle and provide a robust basis for 405-kyr-scale calibration of the ATS. This 405-kyr metronome will enable extension of the well-defined Cenozoic ATS for scaling of the past quarter-billion years of Earth history. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS have already provided new insights into long-standing geologic problems of seafloor spreading, tectonics, eustasy, and paleoclimate change. Ongoing work is focused on closing gaps in coverage and on collecting duplicate cyclostratigraphic records for the entire Mesozoic Era.

  4. The stability and electronic structure of lithium adsorbed in triplet form of (5.0) carbon nanotubes and (5.0) boron nitrogen nanotubes: Density functional theory studies

    NASA Astrophysics Data System (ADS)

    Li, Ke Jing; Shao, Qing Yi; Zhang, Juan; Yao, Xin Hua

    2016-07-01

    Using density functional theory (DFT), we have investigated the stability and electronic structure of lithium (Li) adsorbed in triplet form of (5.0) carbon nanotubes (CNTs) and (5.0) boron nitrogen nanotubes (BNNTs). We have mainly found that three (5.0) tubes are covalently connected. The triplet form is an energetically stable semiconductor. Li atom can be chemically adsorbed in the triplet form of nanotubes (NTs). Meanwhile, upon the adsorption of Li, the triplet form convert into metal. Hence, the triplet form can improve reactivity and sensitivity of NTs to Li significantly.

  5. A distal 140 kyr sediment record of Nile discharge and East African monsoon variability

    NASA Astrophysics Data System (ADS)

    Ehrmann, Werner; Schmiedl, Gerhard; Seidel, Martin; Krüger, Stefan; Schulz, Hartmut

    2016-03-01

    Clay mineral assemblages in a sediment core from the distal Nile discharge plume off Israel have been used to reconstruct the late Quaternary Nile sediment discharge into the eastern Mediterranean Sea (EMS). The record spans the last ca. 140 kyr. Smectite abundances indicate the influence of the Blue Nile and the Atbara River that have their headwaters in the volcanic rocks of the Ethiopian Highlands. Kaolinite abundances indicate the influence of wadis, which contribute periodically to the suspension load of the Nile. Due to the geographical position, the climate and the sedimentary framework of the EMS is controlled by two climate systems. The long-term climate regime was governed by the African monsoon that caused major African humid periods (AHPs) with enhanced sediment discharge at 132 to < 126 (AHP 5), 116 to 99 (AHP4), and 89 to 77 ka (AHP3). They lasted much longer than the formation of the related sapropel layers S5 (> 2 kyr), S4 (3.5 kyr), and S3 (5 kyr). During the last glacial period (Marine Isotope Stages (MISs) 4-2), the long-term changes in the monsoonal system were superimposed by millennial-scale changes in an intensified midlatitude glacial system. This climate regime caused short but pronounced drought periods in the Nile catchment, which are linked to Heinrich events and alternate with more humid interstadials. The clay mineral record further implies that feedback mechanisms between vegetation cover and sediment discharge of the Nile are detectable but of minor importance for the sedimentary record in the southeastern Mediterranean Sea during the investigated African humid periods.

  6. Causal links between Nile floods and eastern Mediterranean sapropel formation during the past 125 kyr confirmed by OSL and radiocarbon dating of Blue and White Nile sediments

    NASA Astrophysics Data System (ADS)

    Williams, M. A. J.; Duller, G. A. T.; Williams, F. M.; Woodward, J. C.; Macklin, M. G.; El Tom, O. A. M.; Munro, R. N.; El Hajaz, Y.; Barrows, T. T.

    2015-12-01

    It has long been hypothesised that beds of highly organic mud or sapropels seen in marine sediment cores retrieved from the floor of the eastern Mediterranean accumulated during times of high Nile fluvial discharge. Our recent fieldwork in the valleys of the Blue Nile, the White Nile and the main Nile has for the first time revealed a sequence of extreme flood episodes synchronous with sapropel units S5 (124 kyr), S4 (102 kyr), S3 (81 kyr), S2 (55 kyr) and S1 (13.5-6.5 kyr). There are more weakly defined links with Nile floods and sapropel units S9 (240 kyr), S8 (217 kyr), S7 (195 kyr), S6 (172 kyr), but the dating error terms are too large to allow us to be too definite. During times of extreme floods over the past 125 kyr, wide distributary channels of the Blue Nile flowed across the Gezira alluvial fan in central Sudan and transported a bed load of sand and gravel into the lower White Nile valley. The sands were reworked by wind to form source-bordering dunes, all of which contain heavy minerals of Ethiopian provenance. These source-bordering dunes were active at 115-105 kyr, 60 kyr and 12-7 kyr, all times of extreme Blue Nile floods. The flood and dune sediments were dated using a combination of optically stimulated luminescence (OSL) and radiocarbon analyses. The Quaternary record of Nile floods discussed here shows a precessional signal and reflects episodes of stronger summer monsoon and more northerly seasonal movement of the ITCZ, linked to times of higher insolation in northern tropical latitudes. Progressive aggradation of Holocene Nile channels in northern Sudan has had a profound influence upon human settlement in the last 8 kyr.

  7. Insolation-driven 100 kyr glacial cycles and millennial climate change

    NASA Astrophysics Data System (ADS)

    Abe-Ouchi, A.; Saito, F.; Kawamura, K.; Raymo, M. E.; Okuno, J.; Takahashi, K.; Blatter, H.

    2013-12-01

    The waxing and waning of Northern Hemisphere ice sheets over the past one million years is dominated by an approximately 100-kyr periodicity and a sawtooth pattern (gradual growth and fast termination). Milankovitch theory proposes that summer insolation at high northern latitudes drives the glacial cycles, and statistical tests demonstrated that the glacial cycles are indeed linked to eccentricity, obliquity and precession cycles. However, insolation alone cannot explain the strong 100 kyr cycle which presumably arises through internal climatic feedbacks. Prior work with conceptual models, for example, showed that glacial terminations are associated with the build-up of Northern Hemisphere 'excess ice', but the physical mechanisms of 100-kyr cycle at work remain unclear. Here, using comprehensive climate and ice sheet models, we show that the ~100-kyr periodicity is explained by insolation and internal feedback amongst the climate, ice sheet and lithosphere/asthenosphere system (reference). We found that equilibrium states of ice sheets exhibit hysteresis responses to summer insolation, and that the shape and position of the hysteresis loop play a key role in determining the periodicities of glacial cycles. The hysteresis loop of the North American ice sheet is such that, after its inception, the ice sheet mass balance remains mostly positive or neutral through several precession cycles whose amplitude decreases towards an eccentricity minimum. The larger the ice sheet grows and extends towards lower latitudes, the smaller is the insolation required to turn the mass balance to negative. Therefore, once the large ice sheet is established, only a moderate increase in insolation can trigger a negative mass balance, leading to a complete retreat within several thousand years, due to the delayed isostatic rebound. The effect of ocean circulation and millennial scale climate change are not playing the dominant role for determing the 100kyr cycle, but are effective for

  8. Hydrographic changes of the Southern Ocean (southeast Indian Sector) Over the last 230 kyr

    NASA Astrophysics Data System (ADS)

    Labeyrie, Laurent; Labracherie, Monique; Gorfti, Nabila; Pichon, Jean Jacques; Vautravers, Maryline; Arnold, Maurice; Duplessy, Jean-Claude; Paterne, Martine; Michel, Elizabeth; Duprat, Josette; Caralp, Michelle; Turon, Jean-Louis

    1996-02-01

    Hydrographical changes of the southern Indian Ocean over the last 230 kyr, is reconstructed using a 17-m-long sediment core (MD 88 770; 46°01'S 96°28'E, 3290m). The oxygen and carbon isotopic composition of planktonic (N. pachyderma sinistra and G. bulloides) and benthic (Cibicidoides wuellerstorfi, Epistominella exigua, and Melonis barleeanum) foraminifera have been analysed. Changes in sea surface temperatures (SST) are calculated using diatom and foraminiferal transfer functions. A new core top calibration for the Southern Ocean allows an extension of the method developed in the North Atlantic to estimate paleosalinities (Duplessy et al., 1991). The age scale is built using accelerator mass spectrometry (AMS) 14C dating of N. pachyderma s. for the last 35 kyr, and an astronomical age scale beyond. Changes in surface temperature and salinity clearly lead (by 3 to 7 kyr) deep water variations. Thus changes in deep water circulation are not the cause of the early response of the surface Southern Ocean to climatic changes. We suggest that the early warming and cooling of the Southern Ocean result from at least two processes acting in different orbital bands and latitudes: (1) seasonality modulated by obliquity affects the high-latitude ocean surface albedo (sea ice coverage) and heat transfer to and from the atmosphere; (2) low-latitude insolation modulated by precession influences directly the atmosphere dynamic and related precipitation/ evaporation changes, which may significantly change heat transfer to the high southern latitudes, through their control on latitudinal distribution of the major frontal zones and on the conditions of intermediate and deep water formation.

  9. The Liang Bua faunal remains: a 95k.yr. sequence from Flores, East Indonesia.

    PubMed

    van den Bergh, G D; Meijer, H J M; Due Awe, Rokhus; Morwood, M J; Szabó, K; van den Hoek Ostende, L W; Sutikna, T; Saptomo, E W; Piper, P J; Dobney, K M

    2009-11-01

    Excavations at Liang Bua, a limestone cave on the island of Flores, East Indonesia, have yielded a well-dated archaeological and faunal sequence spanning the last 95k.yr., major climatic fluctuations, and two human species -H. floresiensis from 95 to 17k.yr.(1), and modern humans from 11k.yr. to the present. The faunal assemblage comprises well-preserved mammal, bird, reptile and mollusc remains, including examples of island gigantism in small mammals and the dwarfing of large taxa. Together with evidence from Early-Middle Pleistocene sites in the Soa Basin, it confirms the long-term isolation, impoverishment, and phylogenetic continuity of the Flores faunal community. The accumulation of Stegodon and Komodo dragon remains at the site in the Pleistocene is attributed to Homo floresiensis, while predatory birds, including an extinct species of owl, were largely responsible for the accumulation of the small vertebrates. The disappearance from the sequence of the two large-bodied, endemic mammals, Stegodon florensis insularis and Homo floresiensis, was associated with a volcanic eruption at 17 ka and precedes the earliest evidence for modern humans, who initiated use of mollusc and shell working, and began to introduce a range of exotic animals to the island. Faunal introductions during the Holocene included the Sulawesi warty pig (Sus celebensis) at about 7ka, followed by the Eurasian pig (Sus scrofa), Long-tailed macaque, Javanese porcupine, and Masked palm civet at about 4ka, and cattle, deer, and horse - possibly by the Portuguese within historic times. The Holocene sequence at the site also documents local faunal extinctions - a result of accelerating human population growth, habitat loss, and over-exploitation. PMID:19058833

  10. Geomagnetic field intensity, North Atlantic Deep Water circulation and atmospheric Δ 14C during the last 50 kyr

    NASA Astrophysics Data System (ADS)

    Laj, Carlo; Kissel, Catherine; Mazaud, Alain; Michel, Elisabeth; Muscheler, Raimund; Beer, Juerg

    2002-06-01

    We present simulated records of past changes in the atmospheric Δ 14C for the last 50 kyr due to changes in geomagnetic field intensity and in the strength of the North Atlantic Deep Water (NADW). A new geomagnetic record was used, largely based on the NAPIS-75 record [Laj et al., Phil. Trans. R. Soc. London A 358 (2000) 1009-1025] which has been extended for the 0-20 kyr interval using archeomagnetic and volcanic data. Past changes of the NADW were derived from a mineral magnetic study of the cores used in the construction of NAPIS-75. Two box models of different complexity (4 and 17 boxes) were used to simulate the carbon cycle. Calculated records of Δ 14C are consistent with experimental determinations for the last 24 kyr. For older ages, the records calculated with variable oceanic circulation conditions reach values as high as 600‰ (with an average of 500‰) between 20 and 40 kyr with maxima around 21, 30 and 38 kyr (GISP2 age model), while low values are observed prior to 42 kyr. Although large inconsistencies in experimental data preclude precise comparison, the average record simulated with the 17-box model is overall consistent with the Icelandic Sea record [Voelker et al., Radiocarbon 40 (1998) 517-534; 42 (2000) 437-452], except for the extremely high peak observed in this record at 40.5 kyr. On the other hand, the results recently reported from a stalagmite recovered from a submerged cave in the Bahamas [Beck et al., Science 292 (2001) 2453-2458] are inconsistent with all our model simulations. In the 20-45 kyr interval, the improved geomagnetic record combined with the new NADW profile allows us to give a modeled evaluation of the relative contribution of these factors to changes in atmospheric Δ 14C. The average simulation provides a first order modeled correction for conventional radiocarbon ages older than 25 kyr for which no calibration curve is available as yet.

  11. A high-resolution mid-Pleistocene temperature record from Arctic Lake El'gygytgyn: a 50 kyr super interglacial from MIS 33 to MIS 31?

    NASA Astrophysics Data System (ADS)

    de Wet, Gregory A.; Castañeda, Isla S.; DeConto, Robert M.; Brigham-Grette, Julie

    2016-02-01

    Previous periods of extreme warmth in Earth's history are of great interest in light of current and predicted anthropogenic warming. Numerous so called "super interglacial" intervals, with summer temperatures significantly warmer than today, have been identified in the 3.6 million year (Ma) sediment record from Lake El'gygytgyn, northeast Russia. To date, however, a high-resolution paleotemperature reconstruction from any of these super interglacials is lacking. Here we present a paleotemperature reconstruction based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) from Marine Isotope Stages (MIS) 35 to MIS 29, including super interglacial MIS 31. To investigate this period in detail, samples were analyzed with an unprecedented average sample resolution of 500 yrs from MIS 33 to MIS 30. Our results suggest the entire period currently defined as MIS 33-31 (∼1114-1062 kyr BP) was characterized by generally warm and highly variable conditions at the lake, at times out of phase with Northern Hemisphere summer insolation, and that cold "glacial" conditions during MIS 32 lasted only a few thousand years. Close similarities are seen with coeval records from high southern latitudes, supporting the suggestion that the interval from MIS 33 to MIS 31 was an exceptionally long interglacial (Teitler et al., 2015). Based on brGDGT temperatures from Lake El'gygytgyn (this study and unpublished results), warming in the western Arctic during MIS 31 was matched only by MIS 11 during the Pleistocene.

  12. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Glasser, Neil F.; Jansson, Krister N.; Duller, Geoffrey A. T.; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-02-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate.

  13. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean

    PubMed Central

    Glasser, Neil F.; Jansson, Krister N.; Duller, Geoffrey A. T.; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-01-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate. PMID:26869235

  14. Toward a continuous 405-kyr-calibrated Astronomical Time Scale for the Mesozoic Era

    NASA Astrophysics Data System (ADS)

    Hinnov, Linda; Ogg, James; Huang, Chunju

    2010-05-01

    Mesozoic cyclostratigraphy is being assembled into a continuous Astronomical Time Scale (ATS) tied to the Earth's cyclic orbital parameters. Recognition of a nearly ubiquitous, dominant ~400-kyr cycling in formations throughout the era has been particularly striking. Composite formations spanning contiguous intervals up to 50 myr clearly express these long-eccentricity cycles, and in some cases, this cycling is defined by third- or fourth-order sea-level sequences. This frequency is associated with the 405-kyr orbital eccentricity cycle, which provides a basic metronome and enables the extension of the well-defined Cenozoic ATS to scale the majority of the Mesozoic Era. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, but with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS provide solutions to long-standing geologic problems of tectonics, eustasy, paleoclimate change, and rates of seafloor spreading.

  15. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.

    PubMed

    Glasser, Neil F; Jansson, Krister N; Duller, Geoffrey A T; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-01-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface "hosing" to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate. PMID:26869235

  16. NGRIP temperature reconstruction from 10 to 120 kyr b2k

    NASA Astrophysics Data System (ADS)

    Kindler, P.; Guillevic, M.; Baumgartner, M.; Schwander, J.; Landais, A.; Leuenberger, M.

    2013-07-01

    In order to reconstruct Greenland NGRIP temperature, measurements of δ15N from the beginning of the Holocene to Dansgaard-Oeschger (DO) event 8 have been performed. Together with previously measured and mostly published δ15N data, we are now able to present for the first time a NGRIP temperature reconstruction for the whole last glacial period (beginning of the Holocene back to 120 kyr) including every DO event based on δ15N isotope measurements using a firn densification and heat diffusion model. The detected temperature rises at DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11), ± 3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the ss09sea06bm time scale in some periods significantly, especially during the last glacial maximum (LGM). A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We continuously calculated α (δ18Oice to temperature sensitivity) on a 10 kyr running time window. α variations show an anticorrelation with obliquity, in agreement with a simple Rayleigh distillation model, and moreover seem to be influenced by Northern Hemisphere ice sheet volume.

  17. Variations in the geomagnetic dipole moment during the Holocene and the past 50 kyr

    NASA Astrophysics Data System (ADS)

    Knudsen, Mads Faurschou; Riisager, Peter; Donadini, Fabio; Snowball, Ian; Muscheler, Raimund; Korhonen, Kimmo; Pesonen, Lauri J.

    2008-07-01

    All absolute paleointensity data published in peer-reviewed journals were recently compiled in the GEOMAGIA50 database. Based on the information in GEOMAGIA50, we reconstruct variations in the geomagnetic dipole moment over the past 50 kyr, with a focus on the Holocene period. A running-window approach is used to determine the axial dipole moment that provides the optimal least-squares fit to the paleointensity data, whereas associated error estimates are constrained using a bootstrap procedure. We subsequently compare the reconstruction from this study with previous reconstructions of the geomagnetic dipole moment, including those based on cosmogenic radionuclides ( 10Be and 14C). This comparison generally lends support to the axial dipole moments obtained in this study. Our reconstruction shows that the evolution of the dipole moment was highly dynamic, and the recently observed rates of change (5% per century) do not appear unique. We observe no apparent link between the occurrence of archeomagnetic jerks and changes in the geomagnetic dipole moment, suggesting that archeomagnetic jerks most likely represent drastic changes in the orientation of the geomagnetic dipole axis or periods characterized by large secular variation of the non-dipole field. This study also shows that the Holocene geomagnetic dipole moment was high compared to that of the preceding ˜ 40 kyr, and that ˜ 4 · 10 22 Am 2 appears to represent a critical threshold below which geomagnetic excursions and reversals occur.

  18. 100 Kyr Old Desert of Western India: Morhodynamics and Environmental Significance

    NASA Astrophysics Data System (ADS)

    Bhatt, N.

    2012-04-01

    The Late Quaternary oscillations in sea levels and resultant changes in the coastal environment have remained a popular aspect of study amongst the earthscientists and archaeologists. The Saurashtra peninsula of the western India that lies on the southwestern side of the Thar Desert, has archived a fascinating record of such environmental changes since last interglacial (~120kyr) in the form of a fossil desert exhibiting various aeolian land forms constituted by the sand largely derived from the coastal areas due to an oscillatory sea level change. A variety of dunes viz., coastal transverse, parabolic, longitudinal, barchans, climbing and falling dunes along with valley fills and sand sheets have been mapped. Being biogenic calcium carbonate rich, the sands have been lithified under the influence of an increase in moisture and thus the dune and bed forms are preserved in its best shape. The intense aeolian activities are also evident in the form of desert varnish on rocky outcrops. The sequence comprises smaller climate perturbations in the form of stabilization, erosion and karstification of older dunes and deposition of fluvial sediments in between. The paper deals with the mode of occurrence, response of sediments to wind dynamics and palaeo topography, internal structures, later modifications of sediments and significance of the geochronologically constrained aeolianites in understanding of environmental changes since 100kyr in the region.

  19. Infrastructure Upgrades to Support Model Longevity and New Applications: The Variable Infiltration Capacity Model Version 5.0 (VIC 5.0)

    NASA Astrophysics Data System (ADS)

    Nijssen, B.; Hamman, J.; Bohn, T. J.

    2015-12-01

    The Variable Infiltration Capacity (VIC) model is a macro-scale semi-distributed hydrologic model. VIC development began in the early 1990s and it has been used extensively, applied from basin to global scales. VIC has been applied in a many use cases, including the construction of hydrologic data sets, trend analysis, data evaluation and assimilation, forecasting, coupled climate modeling, and climate change impact analysis. Ongoing applications of the VIC model include the University of Washington's drought monitor and forecast systems, and NASA's land data assimilation systems. The development of VIC version 5.0 focused on reconfiguring the legacy VIC source code to support a wider range of modern modeling applications. The VIC source code has been moved to a public Github repository to encourage participation by the model development community-at-large. The reconfiguration has separated the physical core of the model from the driver, which is responsible for memory allocation, pre- and post-processing and I/O. VIC 5.0 includes four drivers that use the same physical model core: classic, image, CESM, and Python. The classic driver supports legacy VIC configurations and runs in the traditional time-before-space configuration. The image driver includes a space-before-time configuration, netCDF I/O, and uses MPI for parallel processing. This configuration facilitates the direct coupling of streamflow routing, reservoir, and irrigation processes within VIC. The image driver is the foundation of the CESM driver; which couples VIC to CESM's CPL7 and a prognostic atmosphere. Finally, we have added a Python driver that provides access to the functions and datatypes of VIC's physical core from a Python interface. This presentation demonstrates how reconfiguring legacy source code extends the life and applicability of a research model.

  20. Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

    NASA Astrophysics Data System (ADS)

    Yi, Liang; Chen, Yanping

    2013-04-01

    marine surface and core samples, and to quantitatively reconstruct sea-level variation since the late Pleistocene in the south Bohai Sea, China. New insights into regional relative sea-level changes since the late Pleistocene are obtained (Yi et al., 2012): (1) The grain size of surface and core samples can be mathematically partitioned using the Weibull distribution into four components. These four components with differing modal sizes and percentages could be interpreted as a long-term suspension component, which only settles under low turbulence conditions, sortable silt and very fine sand components transported by suspension during greater turbulence and bedload transport component, respectively. (2) Through regression and rigorous verification techniques, the reference water level could be reconstructed from sediment grain size. The reconstruction quantitatively extends the regional relative sea-level history to the late Pleistocene, providing a comparatively long dataset to evaluate regional sea-level variability. (3) We find no evidence of a sea-level high stand during MIS3 but rather a substantial regression during 70-30 cal kyr BP and potentially exposed land during 38-20 cal kyr BP. These results for the south Bohai Sea are in good agreement with published global sea-level records for the late Pleistocene, implying similarities between local and global sea-level patterns. Therefore, it is concluded that grain-size based sea-level reconstruction provide results that are comparable to other reconstruction methods and demonstrates great potential application for future works. (The data was shared on http://hurricane.ncdc.noaa.gov/) References Chappell, J., Omura, A., Esat, T., McCulloch, M., Pandolfi, J., Ota, Y., Pillans, B., 1996. Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records. Earth and Planetary Science Letters 141, 227-236. Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes

  1. Changes in chemical weathering intensity in the Himalayas over the past 30 kyr

    NASA Astrophysics Data System (ADS)

    Dosseto, A.; Vigier, N.

    2010-12-01

    Chemical weathering and climate are tightly coupled and in an era of rapid climate change, it is critical to be able to understand how erosion processes respond to climate variability. A possible approach is to investigate sedimentary records and study how in the past, sediments have recorded the response of catchment erosion to climate variability. In this study, we have measured lithium (Li) isotopes in sediments deposited on river terraces in the upper Ganges (Alaknanda) and Yamuna basins (India) with deposition ages ranging from 0 to 26 kyr. Li isotopes fractionate during chemical weathering and could potentially give us some insights on past variations of weathering intensity. We find that Li isotope composition vary between -1.5 and 2 ‰. Before 14 kyr ago, sediments exhibit negative values followed a sharp increase to positive values between 11 and 14 kyr ago. This increase in could be explained by (i) an increase in average temperature, where a higher temperature of equilibration between water and precipitating clays results in higher Li isotope ratios; (ii) a change in mineralogy, as the type and crystallinity of clays will fact the isotopic composition; or (iii) a decrease in chemical weathering intensity, as Li isotope ratios are believed to decrease in sediments/soils with increasing weathering intensity (Rudnick et al., 2004). Interestingly, this period of shift in Li isotope composition also corresponds to an intensification of monsoon rainfall. If the change in Li isotope compositions is the result of a decrease of chemical weathering intensity, this would imply that despite of more intense rainfall, weathering has been less intense during the Holocene. This could be explained as greater rainfall will generate more erosion and sediments are likely to spend less time in the basin, thus the amount of time available for weathering is reduced. This would imply that chemical weathering is mostly controlled by the erosive power of greater rainfall over

  2. USDA Food and Nutrient Database for Dietary Studies (FNDDS), 5.0

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Food and Nutrient Database for Dietary Studies (FNDDS) is used to code and analyze dietary intakes for the What We Eat In America, National Health and Nutrition Examination Survey (WWEIA, NHANES). To create FNDDS 5.0 for WWEIA, NHANES 2009-2010, data for over 7,200 foods were updated to incorpo...

  3. The USDA Food and Nutrient Database for Dietary Studies, 5.0

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA Food and Nutrient Database for Dietary Studies (FNDDS) 5.0 is used to code foods and portion sizes and to calculate nutrients for national food surveys. This version of the FNDDS was used to process food intakes from What We Eat In America (WWEIA), the dietary intake component of the Natio...

  4. Geomagnetic intensity variations for the past 6 kyr: New archeointensity results from China

    NASA Astrophysics Data System (ADS)

    Cai, S.; Tauxe, L.; Deng, C.; Zhu, R.

    2013-05-01

    The geomagnetic field is a window to the motion of the fluid outer core of Earth, which has varied over a broad range of timescales. To understand this variation over periods of thousands of years we rely entirely on measurements of remanent magnetization from geological and archeological materials. Archeomagnetic data from Eastern Asia, however, are sparse, particularly those that would be widely regarded as reliable. The longevity of Chinese civilization and the abundant nature of archeological artifacts make archeomagnetic studies within China an important tool for filling in many gaps in our current data sets. In this study, have we carried out paleointensity experiments on 969 specimens, which includes pottery fragments, burnt earth and slags, collected from Shandong, Zhejiang and Hebei Province in China and span the last 6 kyr. Approximately half of the samples yielded results that passed strict data selection and give high-fidelity paleointensities. The virtual axial dipoles moments (VADMs) of our sites range from 4 to 12e22Am2. Our data from the last 2.5 kyr are in good agreement with the ARCH3k.1 model, but deviate at times from the CALS10k.1b model, which is likely due to differences in the data used for these models. At ages older than 3ka, where only the CALS10k.1b model is available for comparison, our data deviate significantly from the model. At ca. 1350 BCE our results suggest a paleointensity high of 12E22Am2, which drops to a low of 4E22Am2 by 2250 BCE. This rapid (less than 1000 year) three-fold change in the paleointensity may have important implications for the dynamics of core flow at this time.

  5. Geomagnetic intensity variations for the past 8 kyr: New archaeointensity results from Eastern China

    NASA Astrophysics Data System (ADS)

    Cai, Shuhui; Tauxe, Lisa; Deng, Chenglong; Pan, Yongxin; Jin, Guiyun; Zheng, Jianming; Xie, Fei; Qin, Huafeng; Zhu, Rixiang

    2014-04-01

    In this study, we have carried out paleointensity experiments on 918 specimens spanning the last ∼7 kyr, including pottery fragments, baked clay and slag, collected from Shandong, Liaoning, Zhejiang and Hebei Provinces in China. Approximately half of the specimens yielded results that passed strict data selection criteria and give high-fidelity paleointensities. The virtual axial dipole moments (VADMs) of our sites range from ∼2×1022 to ∼13×1022 Am. At ∼2250 BCE our results suggest a paleointensity low of ∼2×1022 Am, which increases to a high of ∼13×1022 Am by ∼1300 BCE. This rapid (less than 1000 yrs) six-fold change in the paleointensity may have important implications for the dynamics of core flow at this time. Our data from the last ∼3 kyr are generally in good agreement with the ARCH3k.1 model, but deviate significantly at certain time periods from the CALS3k.4 and CALS10k.1b model, which is likely due to differences in the data used to constrain these models. At ages older than ∼3 ka, where only the CALS10k.1b model is available for comparison, our data deviate significantly from the model. Combining our new results with the published data from China and Japan, we provide greatly improved constraints for the regional model of Eastern Asia. When comparing the variations of geomagnetic field in three global representative areas of Eastern Asia, the Middle East and Southern Europe, a common general trend of sinusoidal variations since ∼8 ka is shown, likely dominated by the dipole component. However, significant disparities are revealed as well, which we attribute to non-dipolar components caused by movement of magnetic flux patches at the core-mantle boundary.

  6. BP details new recycling process

    SciTech Connect

    Chynoweth, E.

    1992-04-22

    BP Chemicals (London) is developing a preprocessing thermal cracker for recycling mixed plastics waste as an add-on to existing petrochemicals or refinery complexes. The company is currently discussing the technology with other plastic producers to {open_quotes}move forward together,{close_quotes} say Serge Huybrechts, branch R&D manager at BP Chemicals at Grangemouth. He says the unit would be able to deliver an intermediate feed of similar composition to chemical naphtha for chemical or refinery processes including steam cracking, catalytic cracking, coking, gasification, and hydrocracking. In comparison, pyrolysis gives a range of products, from light gas to heavy aromatics, that are difficult to integrate into existing equipment.

  7. Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity-inclination correlation revisited

    NASA Astrophysics Data System (ADS)

    Yamazaki, Toshitsugu; Kanamatsu, Toshiya; Mizuno, Sakiko; Hokanishi, Natsumi; Gaffar, Eddy Z.

    2008-10-01

    A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination-intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen-isotope ratios for one core and inter-core correlation using relative paleointensity for other cores. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that variations on the order of 104 to 105 years occur in inclination as well as paleointensity. A cross-correlation analysis showed that significant in-phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ~100 kyr periods. The regional paleointensity stack with higher resolution than the Sint-800 stack (Guyodo and Valet, 1999) should be useful for paleointensity-assisted chronostratigraphy.

  8. NuSTAR analysis of the PWN and SNR in G21.5-0.9

    NASA Astrophysics Data System (ADS)

    Nynka, Melania; Hailey, C. J.; Reynolds, S. P.; Madsen, K.; Grefenstette, B.; NuSTAR Team

    2014-01-01

    Beginning in July 2012, NuSTAR observed G21.5-0.9, a Crab-like Pulsar Wind Nebula (PWN) with centrally-peaked synchrotron emission located in the Galactic Plane. Though the object is well-studied in the radio, soft X-ray, and TeV energy bands, NuSTAR is the first focusing telescope to observe G21.5-0.9 above 10 keV. We present our analysis of the PWN itself, specifically the detection of a spectral break at 9.7 keV and the energy-dependant size of the PWN. Spatially-resolved hard X-ray images reveal the non-thermal emission along the eastern and Northern rim of the supernova (SN) shell. The implications for SN and PWN physics are discussed.

  9. Computer-Aided System Engineering and Analysis (CASE/A) Programmer's Manual, Version 5.0

    NASA Technical Reports Server (NTRS)

    Knox, J. C.

    1996-01-01

    The Computer Aided System Engineering and Analysis (CASE/A) Version 5.0 Programmer's Manual provides the programmer and user with information regarding the internal structure of the CASE/A 5.0 software system. CASE/A 5.0 is a trade study tool that provides modeling/simulation capabilities for analyzing environmental control and life support systems and active thermal control systems. CASE/A has been successfully used in studies such as the evaluation of carbon dioxide removal in the space station. CASE/A modeling provides a graphical and command-driven interface for the user. This interface allows the user to construct a model by placing equipment components in a graphical layout of the system hardware, then connect the components via flow streams and define their operating parameters. Once the equipment is placed, the simulation time and other control parameters can be set to run the simulation based on the model constructed. After completion of the simulation, graphical plots or text files can be obtained for evaluation of the simulation results over time. Additionally, users have the capability to control the simulation and extract information at various times in the simulation (e.g., control equipment operating parameters over the simulation time or extract plot data) by using "User Operations (OPS) Code." This OPS code is written in FORTRAN with a canned set of utility subroutines for performing common tasks. CASE/A version 5.0 software runs under the VAX VMS(Trademark) environment. It utilizes the Tektronics 4014(Trademark) graphics display system and the VTIOO(Trademark) text manipulation/display system.

  10. Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity-inclination correlation revisited

    NASA Astrophysics Data System (ADS)

    Yamazaki, T.; Kanamatsu, T.; Mizuno, S.; Hokanishi, N.; Gaffar, E. Z.

    2008-12-01

    A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination-intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen-isotope ratios for one core and inter-core correlation using relative paleointensity for other cores. The mean inclinations of the four cores show negative inclination anomalies ranging from -5.2 to -11.2 degree. The western equatorial Pacific is documented as a region of a large negative inclination anomalies, and the observed values are comparable to those expected from the time-averaged field (TAF) models [Johnson and Constable, 1997; Hatakeyama and Kono, 2002]. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that geomagnetic variations on the order of 10 to 100 kyrs occur in inclination as well as paleointensity. A cross-correlation analysis showed that significant in-phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ~100 kyr periods. The regional paleointensity stack with higher resolution than the Sint-800 stack [Guyodo and Valet, 1999] should be useful for paleointensity-assisted chronostratigraphy.

  11. Development and Production of a 201 MHz, 5.0 MW Peak Power Klystron

    SciTech Connect

    Aymar, Galen; Eisen, Edward; Stockwell, Brad; Begum, rasheda; Lenci, Steve; Eisner, Rick; Cesca, Eugene

    2016-01-01

    Communications & Power Industries LLC has designed and manufactured the VKP-8201A, a high peak power, high gain, VHF band klystron. The klystron operates at 201.25 MHz, with 5.0 MW peak output power, 34 kW average output power, and a gain of 36 dB. The klystron is designed to operate between 1.0 MW and 4.5 MW in the linear range of the transfer curve. The klystron utilizes a unique magnetic field which enables the use of a proven electron gun design with a larger electron beam requirement. Experimental and predicted performance data are compared.

  12. Human Exploration of Mars Design Reference Architecture 5.0, Addendum #2

    NASA Technical Reports Server (NTRS)

    Drake, Bret G. (Editor); Watts Kevin D. (Editor)

    2014-01-01

    This report serves as the second Addendum to NASA-SP-2009-566, "Human Exploration of Mars Design Reference Architecture 5.0." The data and descriptions contained within this Addendum capture some of the key assessments and studies produced since publication of the original document, predominately covering those conducted from 2009 through 2012. The assessments and studies described herein are for the most part independent stand-alone contributions. Effort has not been made to assimilate the findings to provide an updated integrated strategy. That is a recognized future effort. This report should not be viewed as constituting a formal plan for the human exploration of Mars.

  13. Biogenic sedimentation beneath the California Current system for the past 30 kyr and its paleoceanographic significance

    USGS Publications Warehouse

    Gardner, J.V.; Dean, W.E.; Dartnell, P.

    1997-01-01

    A north-south transect of 17 cores was constructed along the eastern boundary of the California Current system from 33?? to 42?? N to investigate the changes in biogenic sedimentation over the past 30 kyr. Percentages and mass accumulation rates of CaCO3, Corg, and biogenic opal were assembled at 500 to 1000 years/sample to provide relatively high resolution. Time-space maps reveal a complex pattern of changes that do not follow a simple glacial-interglacial two-mode model. Biogenic sedimentation shows responses that are sometimes time-transgressive and sometimes coeval, and most of the responses show more consistency within a limited geographic area than any temporal consistency. Reconstructed conditions during late oxygen isotope stage 3 were more like early Holocene conditions than any other time during the last 30 kyr. Coastal upwelling and productivity during oxygen isotope stage 3 were relatively strong along the central California margin but were weak along the northern California margin. Precipitation increased during the last glacial interval in the central California region, and the waters of the southern California margin had relatively low productivity. Productivity on the southern Oregon margin was relatively low at the beginning of the last glacial interval, but by about 20 ka, productivity in this area significantly increased. This change suggests that the center of the divergence of the West Wind Drift shifted south at this time. The end of the last glacial interval was characterized by increased productivity in the southern California margin and increased upwelling along the central California margin but upwelling remained weak along the northern California margin. A sudden (<300 years) decrease in CaCO3, Corg, and biogenic opal occurred at 13 ka. The changes suggest a major reorientation of the atmospheric circulation in the North Pacific and western North America and the establishment of a strong seasonality in the central California region. A

  14. Circum-Antarctic Nd isotope variability during the last 30 kyrs

    NASA Astrophysics Data System (ADS)

    Struve, T.; van de Flierdt, T.; Hines, S. K.; Burke, A.; Adkins, J. F.; Robinson, L. F.; Crocket, K. C.; Auro, M. E.

    2014-12-01

    The modern Southern Ocean is a key area for the global ocean circulation as wind-driven mixing, upwelling and redistribution of water masses in the Antarctic Circumpolar Current (ACC) all have a significant impact on the properties and flow patterns of global water masses. It has been suggested that the Southern Ocean plays a critical role in oceanographic and climatic changes observed on glacial-interglacial timescales, in particular with respect to carbon sequestration between the deep ocean and the atmosphere. For the purpose of unravelling Southern Ocean water mass composition at intermediate depth during the past 30 kyrs, we here utilise the Nd isotopic composition of the aragonitic skeletons of solitary deep-sea corals. These corals were collected from two locations, the Drake Passage and the area south of Tasmania, and from water depths between 300 and 1750 m. Modern coral specimen were calibrated against nearby seawater. Neodymium was collected from the wash fraction of the anion-exchange column, which represents the first step in preparing samples for precise U-series dating. Subsequent Nd separation utilised a two-stage ion chromatography (RE-spec/cation exchange and Ln-spec resins). Isotopic analyses were performed as NdO+ on a Triton TIMS using a TaF5 activator on W filaments yielding 2σ external reproducibilities of ~20 ppm. (Sub-) millenial scale deep-sea coral neodymium isotope results from the Drake Passage suggest that the modern homogenous ACC neodymium isotopic composition of ɛNd≈ -8 is a very recent feature. During the past 30 kyrs Nd isotope variability on the order of two epsilon units are observed at intermediate water depths as well as repeated changes in water column stratification. We will discuss our new results in the context of other Southern Ocean records, as well as preliminary Nd isotope data from glacial to deglacial deep-sea corals from south of Tasmania in order to constrain the last glacial to deglacial circum-Antarctic Nd

  15. Environmental changes, climate and anthropogenic impact in south-east Tunisia during the last 8 kyr

    NASA Astrophysics Data System (ADS)

    Jaouadi, Sahbi; Lebreton, Vincent; Bout-Roumazeilles, Viviane; Siani, Giuseppe; Lakhdar, Rached; Boussoffara, Ridha; Dezileau, Laurent; Kallel, Nejib; Mannai-Tayech, Beya; Combourieu-Nebout, Nathalie

    2016-06-01

    Pollen and clay mineralogical analyses of a Holocene sequence from Sebkha Boujmel (southern Tunisia) trace the climatic and environmental dynamics in the lower arid bioclimatic zone over the last 8000 years. During the mid- to late Holocene transition, between ca. 8 and 3 ka BP, a succession of five wet-dry oscillations is recorded. An intense arid event occurs between ca. 5.7 and 4.6 ka BP. This episode marks the onset of a long-term aridification trend with a progressive retreat of Mediterranean woody xerophytic vegetation and of grass steppes. It ends with the establishment of pre-desert ecosystems around 3 ka BP. The millennial-scale climate change recorded in the data from Sebkha Boujmel is consistent with records from the south and east Mediterranean, as well as with climatic records from the desert region for the end of the African Humid Period (AHP). Eight centennial climatic events are recorded at Sebkha Boujmel and these are contemporary with those recorded in the Mediterranean and in the Sahara. They indicate a clear coupling between the southern Mediterranean and the Sahara before 3 ka BP. The event at 4.2 ka BP is not evidenced and the link between events recorded in Sebkha Boujmel and the North Atlantic cooling events is clearer from ca. 3 ka BP onwards. These variations indicate the importance of climatic determinism in the structuring of landscapes, with the establishment of the arid climatic conditions of the late Holocene. It is only from ca. 3 ka BP onwards that the dynamic of plant associations is modified by both human activity and climatic variability. The climatic episodes identified during the historic period indicate strong regionalisation related to the differential impact of the North Atlantic Oscillation (NAO) and the Mediterranean Oscillation (MO) on the Mediterranean Basin. The local human impact on regional ecosystems is recorded in the form of episodes of intensification of pastoral and/or agricultural activities. The development of

  16. Visualization of Metabolic Interaction Networks in Microbial Communities Using VisANT 5.0

    PubMed Central

    Wang, Yan; DeLisi, Charles; Segrè, Daniel; Hu, Zhenjun

    2016-01-01

    The complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT’s unique metagraph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction network between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the “symbiotic layout” of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues. VisANT is freely available at: http://visant.bu.edu and COMETS at http://comets.bu.edu. PMID:27081850

  17. Estimating the Numerical Diapycnal Mixing in the GO5.0 Ocean Model

    NASA Astrophysics Data System (ADS)

    Megann, A.; Nurser, G.

    2014-12-01

    Constant-depth (or "z-coordinate") ocean models such as MOM4 and NEMO have become the de facto workhorse in climate applications, and have attained a mature stage in their development and are well understood. A generic shortcoming of this model type, however, is a tendency for the advection scheme to produce unphysical numerical diapycnal mixing, which in some cases may exceed the explicitly parameterised mixing based on observed physical processes, and this is likely to have effects on the long-timescale evolution of the simulated climate system. Despite this, few quantitative estimations have been made of the magnitude of the effective diapycnal diffusivity due to numerical mixing in these models. GO5.0 is the latest ocean model configuration developed jointly by the UK Met Office and the National Oceanography Centre (Megann et al, 2014), and forms part of the GC1 and GC2 climate models. It uses version 3.4 of the NEMO model, on the ORCA025 ¼° global tripolar grid. We describe various approaches to quantifying the numerical diapycnal mixing in this model, and present results from analysis of the GO5.0 model based on the isopycnal watermass analysis of Lee et al (2002) that indicate that numerical mixing does indeed form a significant component of the watermass transformation in the ocean interior.

  18. Visualization of metabolic interaction networks in microbial communities using VisANT 5.0

    DOE PAGESBeta

    Granger, Brian R.; Chang, Yi -Chien; Wang, Yan; DeLisi, Charles; Segre, Daniel; Hu, Zhenjun

    2016-04-15

    Here, the complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT's unique meta-graph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction networkmore » between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the "symbiotic layout" of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues.« less

  19. Visualization of Metabolic Interaction Networks in Microbial Communities Using VisANT 5.0.

    PubMed

    Granger, Brian R; Chang, Yi-Chien; Wang, Yan; DeLisi, Charles; Segrè, Daniel; Hu, Zhenjun

    2016-04-01

    The complexity of metabolic networks in microbial communities poses an unresolved visualization and interpretation challenge. We address this challenge in the newly expanded version of a software tool for the analysis of biological networks, VisANT 5.0. We focus in particular on facilitating the visual exploration of metabolic interaction between microbes in a community, e.g. as predicted by COMETS (Computation of Microbial Ecosystems in Time and Space), a dynamic stoichiometric modeling framework. Using VisANT's unique metagraph implementation, we show how one can use VisANT 5.0 to explore different time-dependent ecosystem-level metabolic networks. In particular, we analyze the metabolic interaction network between two bacteria previously shown to display an obligate cross-feeding interdependency. In addition, we illustrate how a putative minimal gut microbiome community could be represented in our framework, making it possible to highlight interactions across multiple coexisting species. We envisage that the "symbiotic layout" of VisANT can be employed as a general tool for the analysis of metabolism in complex microbial communities as well as heterogeneous human tissues. VisANT is freely available at: http://visant.bu.edu and COMETS at http://comets.bu.edu. PMID:27081850

  20. The U5.0 undulator design for the advanced light source at LBL

    NASA Astrophysics Data System (ADS)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.; Savoy, R.

    1990-05-01

    The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5-cm period and a 5-m length with an 0.837-T maximum field at a 14-mm gap. A hybrid configuration utilizing NdFeB permanent magnet material and vanadium permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is accomplished with permanent magnet rotators. The support structure features a four-post configuration, a rigid base with three kinematic floor supports, and two rigid 5-m long backing beams that fit within the 2.4-m-high accelerator enclosure. The drive system is computer-controlled using a stepper motor and shaft encoder coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps.

  1. The U5. 0 undulator design for the advanced light source at LBL

    SciTech Connect

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.; Savoy, R.

    1989-08-01

    The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5 cm period, 5 m length with a 0.837 T maximum field at a 14 mm gap. A hybrid configuration utilizing Nd-Fe-B permanent magnet material and Vanadium Permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is with permanent magnet rotators. The supports structure features a 4-post configuration, a rigid base with 3 kinematic floor supports and 2 rigid 5 m long backing beams that fit within the 2.4 m high accelerator enclosure. The drive system is computer controlled utilizing a stepper motor and shaft encode coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps. 5 figs., 1 tab.

  2. Power Requirements for The NASA Mars Design Reference Architecture (DRA) 5.0

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    2009-01-01

    This paper summarizes the power systems analysis results from NASA s recent Mars DRA 5.0 study which examined three architecture options and resulting mission requirements for a human Mars landing mission in the post-2030 timeframe. DRA 5.0 features a long approximately 500 day surface stay split mission using separate cargo and crewed Mars transfer vehicles. Two cargo flights, utilizing minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crew during the next mission opportunity approximately 26 months later. The pre-deployment of cargo poses unique challenges for set-up and emplacement of surface assets that results in the need for self or robotically deployed designs. Three surface architecture options were evaluated for breadth of science content, extent of exploration range/capability and variations in system concepts and technology. This paper describes the power requirements for the surface operations of the three mission options, power system analyses including discussion of the nuclear fission, solar photovoltaic and radioisotope concepts for main base power and long range mobility.

  3. Palaeoecology of a 3-kyr biosedimentary record of a coral reef-supporting carbonate shelf

    NASA Astrophysics Data System (ADS)

    Almeida, Carine M.; Barbosa, Catia Fernandes; Cordeiro, Renato C.; Seoane, José Carlos S.; Fermino, Gerson M.; Silva, Patricia O.; Turcq, Bruno J.

    2013-11-01

    This study assesses the 3-kyr paleoecology and sedimentary evolution of the Abrolhos carbonate shelf, Bahia, Brazil, using a two-meter-long core collected in a carbonate muddy sediment. The paleoecology was based on the distribution of benthic foraminifer functional groups associated with grain size, total organic carbon (TOC), total nitrogen (TN), C/N and δ13C. The results identified three biosedimentary units showing that symbiont-bearing foraminifers (Peneroplis and Archaias) decrease in abundance. However, other small taxa (Miliolinella and Cornuspira) and stress-tolerant genera (Bolivina, Elphidium and Ammonia) increase in abundance toward the core top. Grain size decreases toward the top of the core, suggesting a weakening of hydrodynamic winnowing toward recent time. The TOC and TN concentrations increase, and the C/N ratios decrease, suggesting an increase of marine productivity from nearby goblet-shaped structures called "chapeirões". Changes in the benthic foraminifer community can be linked to the sedimentological and organic matter input, which are the result of climatic and oceanographic variations at different spatial and time scales, thus illustrating reduced potential to support symbiont-bearing foraminifer communities to the end of the Holocene.

  4. Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core

    NASA Astrophysics Data System (ADS)

    Kindler, P.; Guillevic, M.; Baumgartner, M.; Schwander, J.; Landais, A.; Leuenberger, M.; Spahni, R.; Capron, E.; Chappellaz, J.

    2014-04-01

    In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ15N have been performed covering the time period from the beginning of the Holocene to Dansgaard-Oeschger (DO) event 8. Together with previously measured and mostly published δ15N data, we present for the first time a NGRIP temperature reconstruction for the whole last glacial period from 10 to 120 kyr b2k (thousand years before 2000 AD) including every DO event based on δ15N isotope measurements combined with a firn densification and heat diffusion model. The detected temperature rises at the onset of DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11) with an uncertainty of ±3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the NGRIP ss09sea06bm timescale in some periods by 30 to 35%, especially during the last glacial maximum. A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ18Oice sensitivity to temperature (referred to as α) and obliquity in agreement with a simple Rayleigh distillation model. Finally, we suggest that α might be influenced by the Northern Hemisphere ice sheet volume.

  5. Progress in the reconstruction of Quaternary climate dynamics in the Northwest Pacific: A new modern analogue reference dataset and its application to the 430-kyr pollen record from Lake Biwa

    NASA Astrophysics Data System (ADS)

    Tarasov, Pavel E.; Nakagawa, Takeshi; Demske, Dieter; Österle, Hermann; Igarashi, Yaeko; Kitagawa, Junko; Mokhova, Lyudmila; Bazarova, Valentina; Okuda, Masaaki; Gotanda, Katsuya; Miyoshi, Norio; Fujiki, Toshiyuki; Takemura, Keiji; Yonenobu, Hitoshi; Fleck, Andreas

    2011-09-01

    This study presents a newly compiled dataset of modern pollen and climate data from 798 sites across Japan and the Russian Far East. This comprehensive reference dataset combined with the modern analogue technique (MAT) provides a powerful tool for pollen-based reconstruction of the Quaternary Northwest Pacific climate. Pollen-derived reconstruction of the modern climate at the reference pollen-sampling sites matches well with the estimated modern climate values ( R2 values vary between 0.79 and 0.95, and RMSEP values vary between 5.8 and 9.7% of the modern climatic range for all nine tested variables). The successful testing of the method encourages its application to the fossil pollen records. We used a coarse-resolution pollen record from Lake Biwa to reconstruct glacial-interglacial climate dynamics in central Japan since ~ 438 kyr and compared it to the earlier reconstruction based on a less representative reference dataset. The current and earlier results consistently demonstrate that the coldest glacial intervals experienced pronounced cooling in winter and moderate cooling in summer, supporting the growth of cool mixed forest (COMX) where warm mixed forest (WAMX) predominates today. During the last glacial, maximum (~ 24 kyr BP) mean temperatures of the coldest (MTCO) and warmest (MTWA) month were about - 13 °C (RMSEP = 2.34 °C) and 21 °C (RMSEP = 1.66 °C) respectively, and annual precipitation (PANN) was about 800 mm (RMSEP = 158.06 mm). During the thermal optimums of the interglacial intervals, the temperatures of the coldest and warmest month were above 0 °C and 25 °C respectively, leading to the reconstruction of WAMX and temperate conifer forest (TECO). Although both these vegetation types grow in the southern part of Japan today, WAMX requires warmer space. The presence of WAMX during marine isotope stages (MIS) 11 and 1, and its absence during MIS 9 and MIS 5 contradict the marine isotope and Antarctic ice records, suggesting that the latter

  6. Nuclear waste glass product consistency test (PCT), Version 5.0. Revision 2

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

  7. Modeling of the Dust and Gas Outflows from OH 26.5+0.6: The Superwind

    NASA Technical Reports Server (NTRS)

    Justtanont, K.; Skinner, C. J.; Tielens, A. G. G. M.; Meixner, M.; Baas, F.

    1996-01-01

    We have observed the extreme OH/IR star, OH 26.5+0.6, in the infrared dust continuum and in the sub- millimeter rotational lines of CO. Mid-infrared images reveal the compact nature of the circumstellar shell (less than 0.5 sec). A deep 9.7 microns absorption feature and an absorption at 18 microns show that the dust mass-loss rate is very high. However, the low antenna temperatures of CO J = 1-0 and 2-1 lines suggest that the outer part of the circumstellar shell is much more tenuous. In order to resolve this discrepancy, we have observed the J = 3-2 and 4-3 CO rotational transitions. We have developed a model for the circumstellar shell for OH 26.5 + 0.6 which is consistent with the infrared and submillimeter observations. The dust and gas data are well fitted by a two-shell model, consisting of a dense shell surrounded by a more tenuous shell. The former we identify with the superwind (M = 5.5 x 10(exp -4) solar mass/ yr), and the latter we identify with mass loss on the asymptotic giant branch (AGB) (M = 10(exp -6) solar mass/ yr). The transition between the two mass-loss phases is shown to be rather abrupt ((Delta)t less than 150 yr). Depending on the mass of the progenitor, this superwind phase may be the last thermal pulse (for M(sub *) less than 1.5 solar mass), or the first of a series of the superwind phases (for up to 8 solar mass), punctuated by a period of low mass-loss rates, before the star evolves off the AGB.

  8. Estimating the numerical diapycnal mixing in the GO5.0 ocean model

    NASA Astrophysics Data System (ADS)

    Megann, Alex; Nurser, George

    2014-05-01

    Constant-depth (or "z-coordinate") ocean models such as MOM and NEMO have become the de facto workhorse in climate applications, and have attained a mature stage in their development and are well understood. A generic shortcoming of this model type, however, is a tendency for the advection scheme to produce unphysical numerical diapycnal mixing, which in some cases may exceed the explicitly parameterised mixing based on observed physical processes (e.g. Hofmann and Maqueda, 2006), and this is likely to have effects on the long-timescale evolution of the simulated climate system. Despite this, few quantitative estimations have been made of the typical magnitude of the effective diapycnal diffusivity due to numerical mixing in these models. GO5.0 is the latest ocean model configuration developed jointly by the UK Met Office and the National Oceanography Centre (Megann et al, 2013). It uses version 3.4 of the NEMO model, on the ORCA025 global tripolar grid. Two approaches to quantifying the numerical diapycnal mixing in this model are described: the first is based on the isopycnal watermass analysis of Lee et al (2002), while the second uses a passive tracer to diagnose mixing across density surfaces. Results from these two methods will be compared and contrasted. Hofmann, M. and Maqueda, M. A. M., 2006. Performance of a second-order moments advection scheme in an ocean general circulation model. JGR-Oceans, 111(C5). Lee, M.-M., Coward, A.C., Nurser, A.G., 2002. Spurious diapycnal mixing of deep waters in an eddy-permitting global ocean model. JPO 32, 1522-1535 Megann, A., Storkey, D., Aksenov, Y., Alderson, S., Calvert, D., Graham, T., Hyder, P., Siddorn, J., and Sinha, B., 2013: GO5.0: The joint NERC-Met Office NEMO global ocean model for use in coupled and forced applications, Geosci. Model Dev. Discuss., 6, 5747-5799,.

  9. Time evolution of the mineralogical composition of Mississippi Valley loess over the last 10 kyr: Climate and geochemical modeling

    NASA Astrophysics Data System (ADS)

    Goddéris, Yves; Williams, Jennifer Z.; Schott, Jacques; Pollard, Dave; Brantley, Susan L.

    2010-11-01

    Anthropogenic and natural climate change affect processes in the atmosphere, biosphere, hydrosphere, and pedosphere. The impact of climate on soil evolution has not been well-explored, largely due to slow rates and the complexity of coupled processes that must be observed and simulated. The rates of mineral weathering in loess deposited 23 kyr ago and experiencing soil formation for 13 kyr are explored here using the WITCH model for weathering and the GENESIS model for climate simulation. The WITCH model, which uses rigorous kinetic parameters and laws with provision for the effect on rates of deviation from equilibrium, can successfully simulate the depletion profiles in the soil for dolomite and albite if soil CO 2 is assumed to rise over the last 10 kyr up to about 30-40× the present atmospheric pressure, and if the solubility product of the Ca-smectite is assumed equal to that of an Fe(III)-rich Ca-montmorillonite. Such simulations document that dissolution behavior for silicates and carbonates are strongly coupled through pH, and for Ca-smectite and feldspars through dissolved silica. Such coupling is not incorporated in simple geometric and analytical models describing mineral dissolution, and therefore probably contributes to the long-standing observation of discrepancies among laboratory and field mineral dissolution rates.

  10. Indian Ocean sea surface temperatures and vegetation change in SE African tropics during the past 800 Kyr

    NASA Astrophysics Data System (ADS)

    Castaneda, I. S.; Caley, T.; Dupont, L. M.; Kim, J.; Sinninghe Damsté, J. S.; Malaize, B.; Caillon, N.; Giraudeau, J.; Schouten, S.

    2011-12-01

    Presently, few vegetation records exist for the region of SE Africa that span multiple glacial-interglacial cycles yet such records can provide important insights into past continental climatic variability. Here, we examine vegetation and SST change in SE Africa from a ~800 Kyr sediment core (MD96-2048) collected from the continental shelf near the Limpopo River, which drains Botswana, southern Mozambique and northern South Africa. The coring site is located at 26°S and is likely situated outside of the influence of the Intertropical Convergence Zone (ITCZ). We find that plant leaf wax (n-alkane) carbon isotope (δ13C) and pollen records are in good agreement and exhibit pronounced glacial-interglacial variability. Relatively enriched n-alkane δ13C values are noted during glacial periods and reflect increased inputs of C4 vegetation, coincident with higher percentages of Poaceae (grass) pollen and cooler SST. Conversely, during interglacials, relatively depleted n-alkane δ13C values are noted and coincide with higher percentages of woodland and forest pollen and warmer SST. Previous studies of this core demonstrated that SST and salinity records based on both inorganic (δ18O and Mg/Ca) and organic (Uk'37 and TEX86) geochemical proxies display strong obliquity-driven 41-Kyr cycles, that are nearly in phase with annual mean insolation and air temperature at the high southern latitudes (Caley et al., 2011). Likewise, the n-alkane δ13C record was found to contain a strong 41-Kyr obliquity cycle. Interestingly, a strong 23-Kyr precession cycle is also present in the n-alkane δ13C record, that is nearly in phase with precession minima. Our results therefore suggest that vegetation change in this region reflects the dual influence of both southern and northern high-latitude climate forcings. In contrast to the Lake Malawi (East Africa) pollen record, which indicates a treeless landscape and extreme aridity from 105-90-Kyr (Beuning et al., 2011), the pollen record of

  11. Sea surface temperature reconstructions over the last 70 kyr off Portugal: Biomarker data and regional modeling

    NASA Astrophysics Data System (ADS)

    Darfeuil, Sophie; Ménot, Guillemette; Giraud, Xavier; Rostek, Frauke; Tachikawa, Kazuyo; Garcia, Marta; Bard, Édouard

    2016-01-01

    This study aims at providing robust temperature reconstructions for a key oceanographic setting in the North Atlantic and at understanding the nature of the temperature signal recorded by the two biomarkers Uk'37 and TEX86, considering season and depth of production. To do so, high-resolution signals of Uk'37 and TEX86 are determined for the last 70 kyr for core MD95-2042, located off Portugal. Signals of Uk'37 and TEX86 present a tight correlation, demonstrating a dominant temperature effect. Uk'37 signals correspond well to the annual mean sea surface temperature (SST), whereas TEXH86-derived temperatures are 5.6°C higher, which is unrealistically warm for this area. Unsuitable TEX86 global linear calibrations on the Iberian Margin may suggest a possible occurrence of archaeal communities with specific temperature response. To assess the impact of different season or depth of production of the biomarkers on the recorded temperature in the sediment, modeled temperature proxies (Tproxies) are introduced in a Regional Oceanic Modeling System and tested for different seasons (annual/summer/winter) and depths (surface and 0-200 m) of production for three climate modes (Present Day (PD), Last Glacial Maximum (LGM), and Heinrich Stadials (HS)). Similar temperature amplitudes between climate modes are found at MD95-2042 core site for observations, for both biomarkers, and for modeled annual surface production Tproxy: 5.5-7°C for ΔT(PD-LGM) and 3-4°C for ΔT(LGM-HS). Therefore, we propose a new TEXH86 regional calibration to reconstruct present and past annual mean SSTs on the Iberian Margin.

  12. Wide Field Camera 3 Instrument Handbook for Cycle 21 v. 5.0

    NASA Astrophysics Data System (ADS)

    Dressel, L.

    2012-12-01

    The Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument. It was installed in the Hubble Space Telescope (HST) during Servicing Mission 4 (SM4) in May 2009. WFC3 saw first light on June 24, 2009, following the cooling of its detectors. Servicing Mission 4 Observatory Verification (SMOV) activities were completed in late August 2009, and were followed by the Cycle 17 calibration and science programs. This WFC3 Instrument Handbook has been prepared by the WFC3 team at STScI. It is the basic technical reference manual for WFC3 observers. The information in this Handbook is intended to be useful for Cycle 21 Phase I proposers, for the subsequently selected General Observers (GOs) as they prepare their Phase II specifications, and for those analyzing WFC3 data. The HST Primer and the HST Call for Proposals also contain valuable information for proposers, and the Call for Proposals is the final authority on HST policy. This edition of the WFC3 Instrument Handbook (Version 5.0) was written near the end of the execution of the Cycle 19 calibration plan. It supersedes Version 4.0, and includes results from analysis of the first three cycles of on-orbit performance.

  13. INTERLINE 5. 0 -- An expanded railroad routing model: Program description, methodology, and revised user's manual

    SciTech Connect

    Johnson, P.E.; Joy, D.S. ); Clarke, D.B.; Jacobi, J.M. . Transportation Center)

    1993-03-01

    A rail routine model, INTERLINE, has been developed at the Oak Ridge National Laboratory to investigate potential routes for transporting radioactive materials. In Version 5.0, the INTERLINE routing algorithms have been enhanced to include the ability to predict alternative routes, barge routes, and population statistics for any route. The INTERLINE railroad network is essentially a computerized rail atlas describing the US railroad system. All rail lines, with the exception of industrial spurs, are included in the network. Inland waterways and deep water routes along with their interchange points with the US railroadsystem are also included. The network contains over 15,000 rail and barge segments (links) and over 13,000 stations, interchange points, ports, and other locations (nodes). The INTERLINE model has been converted to operate on an IBM-compatible personal computer. At least a 286 computer with a hard disk containing approximately 6 MB of free space is recommended. Enhanced program performance will be obtained by using arandom-access memory drive on a 386 or 486 computer.

  14. Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE), Version 5.0

    SciTech Connect

    Russell, K.D.; Kvarfordt, K.J.; Hoffman, C.L.

    1995-10-01

    The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Graphical Evaluation Module (GEM) is a special application tool designed for evaluation of operational occurrences using the Accident Sequence Precursor (ASP) program methods. GEM provides the capability for an analyst to quickly and easily perform conditional core damage probability (CCDP) calculations. The analyst can then use the CCDP calculations to determine if the occurrence of an initiating event or a condition adversely impacts safety. It uses models and data developed in the SAPHIRE specially for the ASP program. GEM requires more data than that normally provided in SAPHIRE and will not perform properly with other models or data bases. This is the first release of GEM and the developers of GEM welcome user comments and feedback that will generate ideas for improvements to future versions. GEM is designated as version 5.0 to track GEM codes along with the other SAPHIRE codes as the GEM relies on the same, shared database structure.

  15. Tests of a model pole assembly for the ALS U5. 0 undulator

    SciTech Connect

    Hassenzahl, W.V.; Hoyer, E. ); Savoy, R. )

    1991-06-01

    The ALS insertion devices must meet very tight requirements in terms of field quality and field strength. Even though the ability to calculate the performance of a hybrid insertion device has improved considerably over the past few years, a model pole was assembled to test the ALS U5.0 undulator geometry and to verify the calculations. The model pole consists of a half period of the periodic structure of the insertion device with mirror plates at the midplane and at the zero-field, half-period planes. A Hall probe was used to measure the vertical component of the field near the midplane of the model as a function of gap and transverse position. Because of the tight field quality requirements the ALS insertion devices are designed to permit several types of correction, including the capability of adding magnetic material or iron at several locations to boost or buck the field. This correction capability was evaluated during our tests. The model is described and details of the test results are discussed, including the fact that the measured peak field is several percent higher than the calculated value, which is based on the measured magnetization of the blocks used in the model. 8 refs., 20 figs., 5 tabs.

  16. Design and test of a model pole for the ALS U5. 0 undulator

    SciTech Connect

    Hassennzahl, W.V.; Hoyer, E. ); Savoy, R. )

    1991-05-01

    The ALS insertion devices must meet very tight requirements in terms of field quality and field strength. Even though the ability to calculate the performance of a hybrid insertion device has improved considerably over the past years, a model pole was assembled to test the ALS U5.0 undulator geometry and to verify the calculations. The model pole consists of a half period of the periodic structure of the insertion device, with mirror plates at the midplane and at the zero-field, half-period planes. A Hall probe was used to measure the vertical component of the field near the midplane of the model as a function of gap and transverse position. Field quality requirements demand that the ALS insertion devices be designed to permit several types of correction, including the capability of adding magnetic material or iron at several locations to boost or buck the field. This correction capability was evaluated during our tests. The model is described and the test results are discussed, including the fact that the measured peak field field is several percent higher than the calculated value, which is based on the measured magnetization of the blocks used in the model. 4 refs., 7 figs.

  17. Lightning activities associated with 308 M≥ 5.0 earthquakes in Taiwan during 1994-2003

    NASA Astrophysics Data System (ADS)

    Liu, J. Y. G.; Chen, Y. I.; Ho, Y. Y.

    2014-12-01

    Earthquake lights and luminous phenomena are spectacular features, which have been often observed and reported. It has been known that the crust deformation activates and releases gases/charges which generate the atmospheric electric field and currents possibly resulting in luminous phenomena before and during large earthquakes. The lightning activity has been known to be one of key parameters understanding the atmospheric electric field near the Earth's surface. However, lightning activities during large earthquakes have not yet been studied and reported. It is found that lightning activities significantly increase 3-8 and 20-30 days before the 21 September 1999 Mw7.6 earthquake. A statistical analysis has been conducted to study lightning activities over the epicenter 30 days before and after 78 land and 230 sea M≥5.0 earthquakes in Taiwan during 1994-2003. We find that lightning activities over the epicenter occur more frequently few days before the land earthquakes which is termed pre-earthquake lightning anomaly (PELA). For earthquakes with larger magnitudes, the PELA appears more frequent and expands a larger area from the epicenter. Our results confirm that the PELA associated with the M≥6.5 land earthquakes with the depth less than 20 km and 18 cumulative days meet the significant level 0.05. These suggest that for the PELA, the Earth's surface deformation plays an important role during the earthquake preparation period. We anticipate our study to be a starting point for developing lithosphere-atmosphere coupling model of earth system sciences.

  18. The plerionic supernova remnant G21.5-0.9: In and out

    NASA Astrophysics Data System (ADS)

    Matheson, Heather; Safi-Harb, Samar

    The absence of a supernova remnant (SNR) shell surrounding the Crab and other plerions (pulsar wind nebulae) has been a mystery for three decades. G21.5-0.9 is a particularly intriguing plerionic SNR in which the central powering engine is not yet detected. Early CHANDRA observations revealed a faint extended X-ray halo which was suggested to be associated with the SNR shell; however its spectrum was non-thermal, unlike what is expected from an SNR shell. On the other hand, a plerionic origin to the halo is problematic since the X-ray plerion would be larger than the radio plerion. We present here our analysis of an integrated 245 ks of archival CHANDRA data acquired with the High-Resolution Camera (HRC) and 520 ks acquired with the Advanced CCD Imaging Spectrometer (ACIS). This study provides the deepest and highest resolution images obtained to date. The resulting images reveal for the first time: (1) a limb-brightened morphology in the eastern section of the halo, and (2) a rich structure in the inner (40″-radius) bright plerion including wisps and a double-lobed morphology with an axis of symmetry running in the northwest-southeast direction. Our spatially resolved spectroscopic study of the ACIS-I data indicates that the photon index steepens with increasing distance from the central point source out to a radius of 40″ then becomes constant at ˜2.4 in the X-ray halo (for a column density NH = 2.2 × 10 22 cm -2). No line emission was found from the eastern limb; however marginal evidence for line emission in the halo's northern knots was found. This study illustrates the need for deep CHANDRA observations to reveal the missing SNR material in Crab-like plerions.

  19. The U5.0 Undulator for the Advanced Light Source

    NASA Astrophysics Data System (ADS)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W. V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1992-01-01

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed, is being fabricated, and is scheduled for completion in early 1992. This undulator will be the first high brightness source, in the 50 to 1,500 eV range, for the Advanced Light Source at the Lawrence Berkeley Laboratory. A hybrid magnetic configuration using Nd-Fe-B permanent magnet material and vanadium permendur poles has been selected to achieve the field quality needed to meet performance requirements. The magnetic structure is modular with each half consisting of five assembly sections, which provide the periodic structure, and end structures, for entrance and exit correction, mounted on a steel backing beam. Each assembly section consists of 35 half-period pole assemblies bolted to a mount. The required 0.837 T effective peak field at a 1.4 cm gap has been verified with model measurements. Vertical field integral correction is accomplished with the end structures, each having an arrangement of permanent magnet rotors which will be adjusted to minimize electron beam missteering over the undulator operating field range. To reduce the effect of environmental fields, the steel backing beams are connected through parallel, low-reluctance, Ni-Fe hinges. The magnetic structure is connected through four rollernuts to the drive system that provides gap adjustment with an arrangement of roller screws, chain drives, a gear reduction unit, and a stepper motor driven by a closed loop control system. Magnetic structure and drive system support are from a 2.4 m high structure which includes a support base with four vertical supports. The vacuum chamber design is a two-piece machined and welded 5083-H321 aluminum construction of 5.1 m length. Pumping is with a combination of ion, titanium sublimation pump and nonevaporable getter pumps. Magnetic design, subsystem design, and fabrication progress are presented.

  20. FERMI/GLAST Integrated Trending and Plotting System Release 5.0

    NASA Technical Reports Server (NTRS)

    Ritter, Sheila; Brumer, Haim; Reitan, Denise

    2012-01-01

    An Integrated Trending and Plotting System (ITPS) is a trending, analysis, and plotting system used by space missions to determine performance and status of spacecraft and its instruments. ITPS supports several NASA mission operational control centers providing engineers, ground controllers, and scientists with access to the entire spacecraft telemetry data archive for the life of the mission, and includes a secure Web component for remote access. FERMI/GLAST ITPS Release 5.0 features include the option to display dates (yyyy/ddd) instead of orbit numbers along orbital Long-Term Trend (LTT) plot axis, the ability to save statistics from daily production plots as image files, and removal of redundant edit/create Input Definition File (IDF) screens. Other features are a fix to address invalid packet lengths, a change in naming convention of image files in order to use in script, the ability to save all ITPS plot images (from Windows or the Web) as GIF or PNG format, the ability to specify ymin and ymax on plots where previously only the desired range could be specified, Web interface capability to plot IDFs that contain out-oforder page and plot numbers, and a fix to change all default file names to show yyyydddhhmmss time stamps instead of hhmmssdddyyyy. A Web interface capability sorts files based on modification date (with newest one at top), and the statistics block can be displayed via a Web interface. Via the Web, users can graphically view the volume of telemetry data from each day contained in the ITPS archive in the Web digest. The ITPS could be also used in nonspace fields that need to plot data or trend data, including financial and banking systems, aviation and transportation systems, healthcare and educational systems, sales and marketing, and housing and construction.

  1. Development and comparison of layer-counted chronologies from the WAIS Divide and EDML ice cores, Antarctica, over the last glacial transition (10-15 ka BP)

    NASA Astrophysics Data System (ADS)

    Winstrup, Mai; Vinther, Bo M.; Sigl, Michael; McConnell, Joe; Svensson, Anders M.; Wegner, Anna

    2014-05-01

    Some ice cores can be very precisely dated far back in time by counting the annual layering in various impurity records, and the most robust chronologies rely on the parallel analysis of annual features expressed in multiple data sets. Layer-counted Antarctic ice-core chronologies are now emerging: Multi-parameter layer counting has been carried out for the Holocene and late glacial section of the EDML ice core, Dronning Maud Land (Vinther et al., in prep.), and a layer-counted timescale for the WAIS Divide core, West Antarctica, reaching back to 30 kyr BP, was recently completed (WDC06A-7; WAIS Divide Members, 2013). Beyond 24 kyr b2k, the main part of this timescale relies solely on electrical measurements on the core. We here use a novel statistical framework for automated annual layer counting (Winstrup et al., 2012) to extend and improve the two chronologies from EDML and WAIS Divide. Using this method, we have 1) revised the multi-parameter layer counts for the EDML ice core back to 15 kyr BP, and 2) employed high-resolution chemistry measurements from WAIS Divide to obtain a layer-counted multi-parameter timescale for WAIS Divide over the same period (10-15 ka b2k). The EDML and WAIS Divide ice cores have been tightly synchronized using volcanic marker horizons, thus allowing a detailed comparison of annual layer counts between tie points using the various approaches. The corresponding timescales are compared also to the EDML timescale from the flow-model based AICC2012 chronology (Veres, 2012). For the Holocene section of the period (10-11.7 ka BP), all timescales show very good agreement. The peculiar accumulation anomaly observed in the WAIS Divide layer thicknesses in the beginning of the Holocene is confirmed by the multi-parameter layer counts from both WAIS Divide and EDML. The transition into the Holocene has generally proven a difficult period to date by annual layer counting, since the appearance of an annual layer in the various records can change

  2. Dust fertilization of biological productivity in the Subarctic North Pacific during the last 150 kyr

    NASA Astrophysics Data System (ADS)

    Serno, S.; Winckler, G.; Anderson, R. F.; Ren, H. A.; Hayes, C.; Machalett, B.; Gersonde, R.; Haug, G. H.

    2012-12-01

    The Subarctic North Pacific (SNP) is one of three principal High Nutrient Low Chlorophyll regions of the modern ocean characterized by an excess pool of macronutrients not completely consumed during the annual biogeochemical cycle. In the last 25 years, a number of studies from the SNP have proposed that eolian dust input of iron from East Asian arid regions is the major limiting factor for primary and export production. In recent years, additional iron sources have been suggested for regulating phytoplankton growth in the SNP, including mobilized continental margin material, ice-rafted debris, volcanic material, turbulent mixing and upwelling. We will present results of a multi-proxy approach from INOPEX core SO202-7-6 and ODP site 882 from the Detroit Seamount in the northwest SNP covering the last 30 and 150 kyr, respectively. We will compare 230Th-normalized dust flux records based on 4He, 232Th and REE, grain size distributions and 230Th-normalized fluxes of opal, total organic carbon, carbonate and biogenic barium and Pa/Th ratios as productivity proxies for INOPEX core SO202-7-6. A new high resolution record of dust fluxes based on 4He will be compared with published productivity proxy records from ODP site 882. A spatial survey of core-top sediments covering the whole SNP indicates that the efficiency of diatom export out of the euphotic zone, as defined by the ratio of opal flux in the core-top sediments to the maximum annual surface water silicate concentration during the winter months, is positively correlated with dust fluxes, possibly as a result of either dust fertilization of primary production or a diatom ballasting effect by dust particles. Preliminary results from INOPEX core SO202-7-6, on the other hand, indicate no correlation between dust flux and biological productivity during the last deglaciation. We will discuss possible explanations for these observations to answer the question if the dust fertilization hypothesis proposed by John Martin

  3. Volcanic synchronization of Dome Fuji and Dome C Antarctic deep ice cores over the past 216 kyr

    NASA Astrophysics Data System (ADS)

    Fujita, S.; Parrenin, F.; Severi, M.; Motoyama, H.; Wolff, E.

    2015-02-01

    Two deep ice cores, Dome Fuji (DF) and EPICA Dome C (EDC), drilled at remote dome summits in Antarctica, were synchronized to better understand their chronology. A total of 1401 volcanic tie points were identified covering the past 216 kyr. DFO2006, the chronology for the DF core characterized by strong constraining by the O2/N2 age markers, was compared with AICC2012, the chronology for 5 cores including the EDC core, and characterized by glaciological approaches combining ice flow modelling with various age markers. The age gaps between the two chronologies are within 2 kyr, except at Marine Isotope Stage (MIS) 5. DFO2006 gives ages older than AICC2012, with peak values of the gap of 4.5 and 3.1 kyr at MIS 5d and MIS 5b, respectively. Accordingly, ratios of duration DFO2006/AICC2012 are 85% at a period from the late stage of MIS 6 to MIS 5d and 114% at a period from MIS 5d to 5b. We then compared the DFO2006 with another chronology of the DF core, DFGT2006, characterized by glaciological approaches with weaker constraining by age markers. Features of the DFO2006/DFGT2006 age gaps are very similar to those of the DFO2006/AICC2012 age gaps. This fact lead us to hypothesize that a cause of the systematic DFO2006/AICC2012 age gaps at MIS 5 are associated with differences in the dating approaches. Besides, ages of speleothem records from China agreed well with DFO2006 at MIS 5c and 5d but not at MIS 5b. Thus, we hypothesize at least at MIS 5c and 5d, major sources of the gaps are systematic errors in surface mass balance estimation in the glaciological approach. Compatibility of the age markers should be carefully assessed in future.

  4. Calcium isotopes in caves as a proxy for aridity: Modern calibration and application to the 8.2 kyr event

    NASA Astrophysics Data System (ADS)

    Owen, R. A.; Day, C. C.; Hu, C.-Y.; Liu, Y.-H.; Pointing, M. D.; Blättler, C. L.; Henderson, G. M.

    2016-06-01

    We present the first study of Ca isotope cycling in a natural cave system, with measurements of bedrock, dripwater and recently formed carbonate, coupled to a first stalagmite time-series spanning the 8.2 kyr event. Dripwaters at Heshang Cave (Central China; 30°27‧N, 110°25‧E) are isotopically heavy relative to the dolomite bedrock, the result of prior calcite precipitation (PCP) occurring earlier in the drip flow path. A simple Rayleigh fractionation model quantifies the extent of PCP in the modern environment at 36% Ca removal. The observed in situ calcium isotope fractionation factor between dripwater and carbonate is Δ 44 / 42 Ca = - 0.63 ± 0.03 ‰ and does not vary during the annual cycle. Measurements of speleothem carbonate spanning the 8.2 kyr event show the response of Ca isotopes to changing climate. δ44/42Ca increases by 0.35‰ at the onset of the event, coeval with changes in δ18O and Mg/Ca, and remains high for 80 yr. This change is explained by decreased rainfall leading to increased PCP; an interpretation supported by established PCP proxies (Mg/Ca, Sr/Ca and Ba/Ca). Ca isotopes indicate that PCP increased to 60% Ca removal during the event, which, from application of a simple box model, suggests mean annual rainfall decreased by approximately a third in Central China during the 8.2 kyr event. The response of Ca isotopes across this event demonstrates their potential for the assessment of past conditions, including past dripwater flow rates and rainfall.

  5. Volcanic synchronization of Dome Fuji and Dome C Antarctic deep ice cores over the past 216 kyr

    NASA Astrophysics Data System (ADS)

    Fujita, S.; Parrenin, F.; Severi, M.; Motoyama, H.; Wolff, E. W.

    2015-10-01

    Two deep ice cores, Dome Fuji (DF) and EPICA Dome C (EDC), drilled at remote dome summits in Antarctica, were volcanically synchronized to improve our understanding of their chronologies. Within the past 216 kyr, 1401 volcanic tie points have been identified. DFO2006 is the chronology for the DF core that strictly follows O2 / N2 age constraints with interpolation using an ice flow model. AICC2012 is the chronology for five cores, including the EDC core, and is characterized by glaciological approaches combining ice flow modelling with various age markers. A precise comparison between the two chronologies was performed. The age differences between them are within 2 kyr, except at Marine Isotope Stage (MIS) 5. DFO2006 gives ages older than AICC2012, with peak values of 4.5 and 3.1 kyr at MIS 5d and MIS 5b, respectively. Accordingly, the ratios of duration (AICC2012 / DFO2006) range between 1.4 at MIS 5e and 0.7 at MIS 5a. When making a comparison with accurately dated speleothem records, the age of DFO2006 agrees well at MIS 5d, while the age of AICC2012 agrees well at MIS 5b, supporting their accuracy at these stages. In addition, we found that glaciological approaches tend to give chronologies with younger ages and with longer durations than age markers suggest at MIS 5d-6. Therefore, we hypothesize that the causes of the DFO2006-AICC2012 age differences at MIS 5 are (i) overestimation in surface mass balance at around MIS 5d-6 in the glaciological approach and (ii) an error in one of the O2 / N2 age constraints by ~ 3 kyr at MIS 5b. Overall, we improved our knowledge of the timing and duration of climatic stages at MIS 5. This new understanding will be incorporated into the production of the next common age scale. Additionally, we found that the deuterium signals of ice, δDice, at DF tends to lead the one at EDC, with the DF lead being more pronounced during cold periods. The lead of DF is by +710 years (maximum) at MIS 5d, -230 years (minimum) at MIS 7a and +60

  6. A 400 kyr record of combustion oxygen demand in the western equatorial Pacific: Evidence for a precessionally forced climate response

    NASA Astrophysics Data System (ADS)

    Perks, Helen M.; Keeling, Ralph F.

    1998-02-01

    We have developed a combustion analysis technique for sediments which measures the amount of O2 consumed by the reduced species. We have measured this quantity, which we call "combustion oxygen demand (COD)," on a carbonate-rich sediment core from the Ontong-Java Plateau in the western equatorial Pacific back to marine oxygen isotope stage 11. The precision of the COD technique is ±6.3 µmol O2 g-1, which corresponds to ˜±0.0076% wt Corg, assuming oxidation of organic carbon dominates the signal. The COD time series is characterized by values which are about twice as high during glacials as during interglacials, the largest shift occurring from 401 µmol O2 g-1 in midstage 6 to 144 µmol O2 g-1 at 5e, and is coherent with the oxygen isotope curve of Globigerinoides sacculifer in the same core at the Milankovitch frequencies of 100 and 41 kyr. Pronounced variations in the 19-23 kyr band suggest that the climate of the western equatorial Pacific is sensitive to precessional forcing, a response not apparent from other records obtained in this region.

  7. Silicic Eruptions of the Past 50 kyr at the Three Sisters Volcanic Cluster

    NASA Astrophysics Data System (ADS)

    Calvert, A. T.; Hildreth, W.; Fierstein, J.

    2003-12-01

    The Three Sisters volcanic cluster in the central Oregon Cascades consists of mafic to intermediate stratovolcanoes surrounded by mafic and silicic flows and domes. The bulk of South and Middle Sister are late Pleistocene while North Sister is middle Pleistocene (Schmidt and Grunder, 2003 GSA abs.). Thick rhyolite and dacite lava flows and domes are rich in potassium, and young glaciation exposes holocrystalline groundmass textures ideal for argon geochronology. Several of these silicic flows bracket stratovolcano growth, and precise geochronology illuminates a rich basalt to rhyolite history in the cluster over the past 50 kyr. Careful step-heating 40Ar/39Ar experiments yield excellent plateau ages with radiogenic yields often above 5% on rocks as young as 20 ka. Most samples have well-determined isochrons with atmospheric (40/36 = 295.5) intercepts, although several have intercepts as low as 286. South Sister is a composite cone with an andesite/dacite base (Hodge Crest) and a young andesite summit sequence. The basal flow of the 300m-thick, youngest conformable stack of andesite lavas at the summit is 27+/-3 ka. Unconformably underlying portions date back to at least 50 ka based on ages of overlapping silicic flows. The base of Middle Sister is andesite overlain by ˜300m of olivine basalt. Some Middle Sister andesites and all basalts overlie a distinctive dacite agglutinate (20+/-2 ka) in the South/Middle Sister saddle. All Middle Sister lavas underlie a thick dacite flow (14+/-3 ka) that vented at 8500 ft (2600m) on its S flank. Dacite lava flows erupted from the Middle/North Sister saddle at 27+/-2 and 18+/-2 ka. Additionally, several >100m-thick rhyolite and dacite lavas vented low on the flanks of the cluster. Obsidian Cliff rhyolite (37.8+/-1.8 ka) and Lane Plateau dacite (21.4+/-1.9 ka) erupted W of Middle Sister, the Dew Lake dacite (32.3+/-1.8 ka) located near the locus of the INSAR anomaly W of South Sister flowed around a 148+/-4 ka (knob 6482) basalt

  8. Electronic states of BP, BP +, BP -, B 2P 2, B2P2- and B2P2+

    NASA Astrophysics Data System (ADS)

    Linguerri, Roberto; Komiha, Najia; Oswald, Rainer; Mitrushchenkov, Alexander; Rosmus, Pavel

    2008-05-01

    Using augmented sextuple zeta basis sets and internally contracted multireference configuration interaction (MRCI) wavefunctions, potential energy, electric dipole and transition moments have been computed for the X 3Π, a 1Σ +, b 1Π and A 3Σ - states of BP, X 2Σ + and A 2Π states of BP - and X 4Σ - and A 4Π states of BP +. From these data spectroscopic constants, radiative transition probabilities and photoelectron spectra of BP - and BP have been evaluated. The non-vanishing spin-orbit coupling elements between the four low lying triplet and singlet states of the neutral BP have also been calculated from MRCI wavefunctions. The treatment of the corresponding perturbations in the manifold of dense rovibrational states in the three lowest states would require a precise knowledge of the electronic excitation energies. Our best singlet-triplet separations (X-a) are calculated to be 2412 cm -1 (MRCI) and 2482 cm -1 (restricted coupled cluster with perturbative triples (RCCSD(T))) with an estimated error bound of about ±200 cm -1. All three states have long radiative lifetimes with cascading among the rovibrational levels of different states. The ionization energy IE e of BP is calculated to be 9.22 eV (MRCI) and 9.48 eV (RCCSD(T)), the electron affinity EA e 2.51 eV (MRCI) and 2.74 eV (RCCSD(T)). The photoelectron spectra of BP and BP - have been obtained from the Franck-Condon factors of the MRCI potentials. For the UV spectroscopy the dipole allowed radiative transition probabilities are given for A 3Σ - ↔ X 3Π, b 1Π ↔ a 1Σ + of BP, A 2Π ↔ X 2Σ + of BP - and A 4Π ↔ X 4Σ - of BP +. The ionization energy IE e of B 2P 2 of 8.71 eV and the electron affinity EA e of 2.34 eV have been calculated by the RCCSD(T)/aVQZ approach. Also the harmonic vibrational wavenumbers for the electronic ground states of the ions B2P2+ and B2P2- are given.

  9. The Environmental impact of the 8.2 and 9.2 kyr events in the UK.

    NASA Astrophysics Data System (ADS)

    Jones, Richard; Reinhardt, Liam; Halloran, Paul; Hatton, Jackie; Marshall, Jim

    2015-04-01

    The instability of the Early Holocene climate in NW Europe is due in part to the impact of freshwater pulses in the North Atlantic disrupting thermohaline circulation and reducing the northward transport of heat. Two of the most significant climatic episodes are the 8.2 and 9.2 kyr events, characterised by significant oxygen isotopic excursions in NW European lacustrine and speleothem records, the Greenland Ice-core record and changing SSTs in the North Atlantic sector. Assessing the impact of these two events on terrestrial systems is problematic due to the difficulty in identifying their signature in terrestrial archives. A sub-decadal oxygen isotope record from a Holocene micrite core from Hawes Water NW England provides unambiguous evidence for two significant isotopic excursions equivalent to the 9.2 and 8.2 kyr events. Lasting 50 and 150 yr respectively they are characterised by a slight cooling of around 1.6oC in mean July air temperatures (chironomid inferred). The environmental impact of each event was minimal, with no evidence for any significant changes in the range or abundance of plant taxa and no evidence for catchment instability. These results support the idea that the 8.2 and 9.2 kyr events are primarily a reflection of the changing isotopic composition of meteoric precipitation (δ18Op) and in the UK at least were of limited environmental significance. Analysis of subpolar gyre behaviour and atmospheric circulation across preindustrial control simulations from CMIP5, suggest that the negative isotopic excursions recorded at Hawes Water most likely reflect the influx of isotopically lighter moisture from the Arctic. An influx of freshwater down the Hudson River and into the North Atlantic Current could result in the development of low pressure anomalies over Scandinavia, bringing arctic air and moisture to the UK. This could be expected to produce the relatively minor decline in summer temperatures but would result in the significant negative shift

  10. Radiolarians, foraminifers, and biostratigraphy of the Coniacian-Campanian deposits of the Alan-Kyr Section, Crimean Mountains

    NASA Astrophysics Data System (ADS)

    Bragina, L. G.; Beniamovsky, V. N.; Kopaevich, L. F.

    2016-01-01

    Data on the distribution of radiolarians and planktonic and benthic foraminifers are obtained for the first time from the Alan-Kyr Section (Coniacian-Campanian), in the central regions of the Crimean Mountains. Radiolarian biostrata, previously established from Ak-Kaya Mountain (central regions of the Crimean Mountains) were traced: Alievium praegallowayi-Crucella plana (upper Coniacian-lower Santonian), Alievium gallowayi-Crucella espartoensis (upper Santonian without the topmost part), and Dictyocephalus (Dictyocryphalus) (?) legumen-Spongosaturninus parvulus (upper part of the upper Santonian). Radiolarians from the Santonian-Campanian boundary beds of the Crimean Mountains are studied for the first time, and Prunobrachium sp. ex gr. crassum-Diacanthocapsa acanthica Beds (uppermost Santonian-lower Campanian) are recognized. Bolivinoides strigillatus Beds (upper Santonian) and Stensioeina pommerana-Anomalinoides (?) insignis Beds (upper part of the upper Santonian-lower part of the lower Campanian) are recognized. Eouvigerina aspera denticulocarinata Beds (middle and upper parts of the lower Campanian) and Angulogavelinella gracilis Beds (upper part of the upper Campanian are recognized on the basis of benthic foraminifers. These beds correspond to the synchronous biostrata of the East European Platform and Mangyshlak. Marginotruncana coronata- Concavatotruncana concavata Beds (Coniacian-upper Santonian), Globotruncanita elevata Beds (terminal Santonian), and Globotruncana arca Beds (lower Campanian) are recognized on the basis of planktonic foraminifers. Radiolarian and planktonic and benthic foraminiferal data agree with one another. The position of the Santonian-Campanian boundary in the Alan-Kyr Section, which is located stratigraphically above the levels of the latest occurrence of Concavatotruncana concavata and representatives of the genus Marginotruncana, is refined, i.e., at the level of the first appearance of Globotruncana arca. A gap in the Middle

  11. BP: synthesis and properties of boron phosphide

    NASA Astrophysics Data System (ADS)

    Woo, Katherine; Lee, Kathleen; Kovnir, Kirill

    2016-07-01

    Cubic boron phosphide, BP, is notorious for its difficult synthesis, thus preventing it from being a widely used material in spite of having numerous favorable technological properties. In the current work, three different methods of synthesis are developed and compared: from the high temperature reaction of elements, Sn flux assisted synthesis, and a solid state metathesis reaction. Structural and optical properties of the products synthesized from the three methods were thoroughly characterized. Solid state metathesis is shown to be the cleanest and most efficient method in terms of reaction temperature and time. Synthesis by Sn flux resulted in a novel Sn-doped BP compound. Undoped BP samples exhibit an optical bandgap of ∼2.2 eV while Sn-doped BP exhibits a significantly smaller bandgap of 1.74 eV. All synthesized samples show high stability in concentrated hydrochloric acid, saturated sodium hydroxide solutions, and fresh aqua regia.

  12. Stratigraphic Correlation of an Excursion at 22 kyr in the U.S. Great Basin - the Hilina Pali Excursion?

    NASA Astrophysics Data System (ADS)

    Liddicoat, J. C.; Coe, R. S.

    2013-12-01

    An unusually large secular variation of the geomagnetic field recorded in outcrops of pluvial Lake Russell sediment about 22 kyr old in the Mono Basin, CA, can be used for precise correlation to other lacustrine sections in the western U.S., and perhaps beyond. We present new AF and thermal demagnetization results for paired samples at 2-cm intervals between ash layers 7 and 8 of Lajoie (1968) in the bank of Wilson Creek that document an excursion having an inclination as low as 16 degrees and as high as 73 degrees, while the declination swings from 15 degrees west during the low inclination to 30 east when the inclination is high, and back to average northerly declination and expected inclination. The corresponding VGPs form a narrow clockwise-trending loop centered at about 50 N, 30 E. The Mono Lake Excursion (MLE; Liddicoat and Coe, 1979) occurs 1.7 m lower in the same section. The best estimates for the ages of the two excursions are about 22 and 32 kyr, based on 14-C dates (Cassata et al., 2010). About 150 km to the north, sediments of about the same age exposed along the Truckee River that were deposited in pluvial Lake Lahontan record a similar geomagnetic signature. Moreover, both the MLE and this excursion are exhibited at the appropriate levels in a sediment core taken from Pyramid Lake, the remnant of Lake Lahontan (Benson et al., 2008). Thus, this excursion is a valuable marker for high-resolution correlation of Quaternary sediments in the western U.S., especially when paired with the MLE. It is tempting to try to identify this geomagnetic feature with others of about the same age further away. On the island of Hawaii, Coe et al. (1978) discovered a lava flow on the Hilina Pali with a calibrated 14-C age of 21 +/-1 kyr that has an inclination about 30 degrees shallower and a paleointensity 60 percent lower than today. Later Teanby et al. (2002) documented an excursion with inclinations as low as -35 degrees, recorded by around 40 successive flows with

  13. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present

    NASA Astrophysics Data System (ADS)

    Hoff, Ulrike; Rasmussen, Tine L.; Stein, Ruediger; Ezat, Mohamed M.; Fahl, Kirsten

    2016-07-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean.

  14. Changes in dominant moisture sources and the consequences for hydroclimate on the northeastern Tibetan Plateau during the past 32 kyr

    NASA Astrophysics Data System (ADS)

    Thomas, Elizabeth K.; Huang, Yongsong; Clemens, Steven C.; Colman, Steven M.; Morrill, Carrie; Wegener, Pamela; Zhao, Jiangtao

    2016-01-01

    Lake Qinghai, located on the northeastern Tibetan Plateau north of the modern maximum summer monsoon extent, is well situated to record northward advances of the summer monsoon. Existing paleoclimate records contain conflicting evidence for the timing of summer monsoon advance into this region: an early arrival pre-Younger Dryas or a late arrival at the beginning of the Holocene. A 30-kyr-long leaf wax hydrogen isotope (n-alkanoic acid, δ2Hwax) record from Lake Qinghai helps to address this discrepancy by elucidating changes in the three main moisture sources in this region: southerly (summer monsoon), northwesterly, and local precipitation. Lake Qinghai δ2Hwax indicates that the arid glacial period was dominated by northwesterly moisture. Extremely arid conditions prevailed from 15 to 14 ka, likely because westerly winds were weakening and the summer monsoon had not yet reached this region. This arid period ended by 13.6 ka when small amounts of summer monsoon precipitation reached Lake Qinghai. Summer monsoon moisture subsequently retreated off of the northeastern Tibetan Plateau during the Younger Dryas and re-advanced in the early Holocene. Summer monsoon precipitation decreased progressively throughout the Holocene in response to decreasing summer insolation, and the modern northwesterly- and local-dominated moisture regime was attained ca. 2.6 ka. Lake Qinghai δ2Hwax demonstrates that the summer monsoon extent was dynamic during the past 30 kyr, responding dramatically to insolation and North Atlantic circulation changes. Moreover, Lake Qinghai δ2Hwax demonstrates that local and northwesterly air masses are important moisture sources to the northeastern Tibetan Plateau, and should be considered when reconstructing past hydroclimate in this region.

  15. Improving medical diagnosis reliability using Boosted C5.0 decision tree empowered by Particle Swarm Optimization.

    PubMed

    Pashaei, Elnaz; Ozen, Mustafa; Aydin, Nizamettin

    2015-08-01

    Improving accuracy of supervised classification algorithms in biomedical applications is one of active area of research. In this study, we improve the performance of Particle Swarm Optimization (PSO) combined with C4.5 decision tree (PSO+C4.5) classifier by applying Boosted C5.0 decision tree as the fitness function. To evaluate the effectiveness of our proposed method, it is implemented on 1 microarray dataset and 5 different medical data sets obtained from UCI machine learning databases. Moreover, the results of PSO + Boosted C5.0 implementation are compared to eight well-known benchmark classification methods (PSO+C4.5, support vector machine under the kernel of Radial Basis Function, Classification And Regression Tree (CART), C4.5 decision tree, C5.0 decision tree, Boosted C5.0 decision tree, Naive Bayes and Weighted K-Nearest neighbor). Repeated five-fold cross-validation method was used to justify the performance of classifiers. Experimental results show that our proposed method not only improve the performance of PSO+C4.5 but also obtains higher classification accuracy compared to the other classification methods. PMID:26737960

  16. Variations in flow and transport in thick desert vadose zones in response to paleoclimatic forcing (0-90 kyr): Field measurements, modeling, and uncertainties

    USGS Publications Warehouse

    Scanlon, B.R.; Keese, K.; Reedy, R.C.; Simunek, J.; Andraski, B.J.

    2003-01-01

    An understanding of unsaturated flow and potential recharge in interdrainage semiarid and arid regions is critical for quantification of water resources and contaminant transport. We evaluated system response to paleoclimatic forcing using water potential and Cl profiles and modeling of nonisothermal liquid and vapor flow and Cl transport at semiarid (High Plains, Texas) and arid (Chihuahuan Desert, Texas; Amargosa Desert, Nevada) sites. Infiltration in response to current climatic forcing is restricted to the shallow (???0.3-3 m) subsurface. Subsurface Cl accumulations correspond to time periods of 9-90 kyr. Bulge-shaped Cl profiles generally represent accumulation during the Holocene (9-16 kyr). Lower Cl concentrations at depth reflect higher water fluxes (0.04-8.4 mm/yr) during the Pleistocene and earlier times. Low water potentials and upward gradients indicate current drying conditions. Nonisothermal liquid and vapor flow simulations indicate that upward flow for at least 1-2 kyr in the High Plains and for 1.2-16 kyr at the Chihuahuan and Amargosa desert sites is required to reproduce measured upward water potential gradients and that recharge is negligible (<0.1 mm/yr) in these interdrainage areas.

  17. G141.2+5.0, A NEW PULSAR WIND NEBULA DISCOVERED IN THE CYGNUS ARM OF THE MILKY WAY

    SciTech Connect

    Kothes, R.; Foster, T. J.; Sun, X. H.; Reich, W.

    2014-04-01

    We report the discovery of the new pulsar wind nebula (PWN) G141.2+5.0 in data observed with the Dominion Radio Astrophysical Observatory's Synthesis Telescope at 1420 MHz. The new PWN has a diameter of about 3.'5, which translates to a spatial extent of about 4 pc at a distance of 4.0 kpc. It displays a radio spectral index of α ≈ –0.7, similar to the PWN G76.9+1.1. G141.2+5.0 is highly polarized up to 40% with an average of 15% in the 1420 MHz data. It is located in the center of a small spherical H I bubble, which is expanding at a velocity of 6 km s{sup –1} at a systemic velocity of v {sub LSR} = –53 km s{sup –1}. The bubble could be the result of the progenitor star's mass loss or the shell-type supernova remnant (SNR) created by the same supernova explosion in a highly advanced stage. The systemic LSR velocity of the bubble shares the velocity of H I associated with the Cygnus spiral arm, which is seen across the second and third quadrants and an active star-forming arm immediately beyond the Perseus arm. A kinematical distance of 4 ± 0.5 kpc is found for G141.2+5.0, similar to the optical distance of the Cygnus arm (3.8 ± 1.1 kpc). G141.2+5.0 represents the first radio PWN discovered in 17 years and the first SNR discovered in the Cygnus spiral arm, which is in stark contrast with the Perseus arm's overwhelming population of shell-type remnants.

  18. Screening for Bacillus subtilis group isolates that degrade cyanogens at pH 4.5-5.0.

    PubMed

    Abban, Stephen; Brimer, Leon; Abdelgadir, Warda S; Jakobsen, Mogens; Thorsen, Line

    2013-01-15

    Cyanogenic food crops abound in nature with important crops like cassava forming the staple food for over half a billion people. Detoxification by hydrolysis of cassava cyanogenic glycosides often involves acid fermentation, and in some of these processes Bacillus species are encountered. Forty Bacillus spp. (20 Bacillus subtilis, 11 Bacillus licheniformis, 7 Bacillus sonorensis, 2 Bacillus cereus) isolated from acid fermented primary starters to produce Gergoush, a Sudanese fermented snack, were screened for their ability to grow and to hydrolyze linamarin, the major cyanogen found in cassava at pH levels below 5.0; also the cyanogen amygdalin was assessed. The B. subtilis isolates grew in both HCl and lactic acid environments from pH 4.5-6.0 while being able to break down the cyanogenic glycosides. The B. licheniformis and B. sonorensis isolates grew and degraded cyanogens at pH 5.0 in a HCl environment, while two B. cereus isolates used in the study showed no breakdown reaction under all conditions tested. One B. subtilis isolate was observed to have substrate specificity between the breakdown of linamarin and amygdalin. We conclude that some Bacillus spp. isolates are important in the microbiological breakdown of cyanogens in cassava fermentations even at pH 4.5-5.0 though further investigations are required. PMID:23261810

  19. Catastrophic flank collapses and slumping in Pico Island during the last 130 kyr (Pico-Faial ridge, Azores Triple Junction)

    NASA Astrophysics Data System (ADS)

    Costa, A. C. G.; Hildenbrand, A.; Marques, F. O.; Sibrant, A. L. R.; Santos de Campos, A.

    2015-09-01

    The Pico Island constitutes the easternmost sub-aerial domain of a steep WNW-ESE volcanic ridge, which has developed within the Nubia-Eurasia diffuse plate boundary (Azores Triple Junction). The island comprises three volcanic systems, from older to younger: the Topo Volcano, the Fissural System, and the Pico Stratovolcano. From a high-resolution Digital Elevation Model (10 m), and new bathymetric, stratigraphic, structural, and high-precision K-Ar data, we reconstruct the main successive stages of growth and partial destruction of the island over the last 200 kyr. We especially concentrate on the central sector of the island, which has recorded gradual movements through slumping and catastrophic flank collapses since ca. 130 kyr. The remmants of the Topo Volcano are partly exposed on Pico's SE flank, and are here dated between 186 ± 5 and 115 ± 4 ka. Topo was significantly destroyed by N- and S-directed large-scale flank collapses between ca. 125 and 70 ka. On Pico's N flank, collapse seems to have removed all the unstable material, but in the S the collapse structure is composite, including a major flank collapse and a remnant slump complex that is still active. A first episode of deformation occurred between ca. 125 and 115 ka along the master fault of the slump. Between ca. 115 and 69 ka, most of the unstable material was removed by a major flank collapse, leaving behind a still considerable volume of unstable material that comprises the active slump. This first collapse was catastrophic and generated a large debris deposit recognized on the high-resolution bathymetry, with a minimum run-out of ca. 17 km. The scar was partially filled by volcanic products erupted from volcanic cones developed within the slump depression, and possibly also from the early WNW-ESE Fissural System. Subsequent deformation in the slump area affected in part the filling units, leading to the individualization of secondary curved faults. Younger volcanic products have gradually

  20. Benthic foraminiferal δ18O-Mg/Ca from the SE Nordic seas during the last 65 kyr

    NASA Astrophysics Data System (ADS)

    Ezat, M.; Rasmussen, T. L.; Groeneveld, J.

    2013-12-01

    Benthic foraminiferal δ18O-Mg/Ca from the SE Nordic seas during the last 65 kyr Mohamed M. Ezat1,2*, Tine L. Rasmussen1, Jeroen Groeneveld3 1 CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, and Department of Geology, University of Tromsø, NO-9037 Tromsø, Norway. 2 Department of Geology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt. 3 Department of Geosciences, University of Bremen, Klagenfurter Strasse, 28359, Bremen, Germany. * e-mail: mohamed.ezat@uit.no The climate during the last glacial period underwent rapid millennial-scale variability known as Dansgaard-Oeschger (DO) events of warm interstadials and cold stadials. DO events are manifested in marine and continental records in the circum-North Atlantic region and throughout the globe. Several studies suggest a crucial role of the Nordic seas in regulating the climate during the last glacial period. Previous studies from the Nordic seas revealed low benthic δ18O values during stadials and high values during interstadials. The causes of the depletions in benthic 18O during stadials are highly debated. Sinking of isotope depleted-brines formed due to sea ice production has previously been proposed. Another explanation has indicated warming of the intermediate water in the Nordic seas based on the finding of warm water benthic foraminiferal species during stadials. Here we present the first benthic foraminiferal Mg/Ca-based bottom water temperature (BWT) record from the Nordic seas that, along with other proxies, aims to resolve the hydrographic changes at intermediate water depth on DO timescale during the last 65 kyr. The results show pronounced and gradual BWT increases during all cold stadials followed by an abrupt drop to modern-like BWT at interstadials onsets. The increase in BWT, caused by the subsurface inflow of warm Atlantic intermediate water, substantially contributed to the halocline collapse and onset of interstadial conditions throughout complex ocean-sea ice

  1. Refractive index of SiO{sub 2} glass at hydrostatic pressures up to 5.0 GPa

    SciTech Connect

    Kuryaeva, R.G.; Kirkinskii, V.A.

    1995-07-01

    The refractometric technique is elaborated for the room-temperature high-pressure measurements up to 5.0 GPa using a diamond anvil cell in conjunction with a polarizing interference microscope. The refractive index of silica glass is measured with an error of no higher than {delta}{eta}={+-}0.005 at the maximum pressure. The refractive index of glass is found to anomalously behave under pressure, with the maximum baric coefficient in the range 2.6-3.0 GPa. The obtained results are analyzed in terms of the Mueller photoelasticity theory and using the previously suggested models of behavior of the fused quartz under pressure.

  2. Functionalized single-walled carbon nanotube (5, 0) as a carrier for isoniazid — A tuberculosis drug

    NASA Astrophysics Data System (ADS)

    Rajarajeswari, M.; Iyakutti, K.; Lakshmi, I.; Rajeswarapalanichamy, R.; Kawazoe, Y.

    2015-06-01

    Nanostructures functionalized with amino acid are able to penetrate the cell wall. In this first principle study, we have demonstrated that the amino acid alanine functionalized carbon nanotubes (CNTs) (5, 0) can be a drug carrier for the tuberculosis drug isoniazid. Isoniazid is binding with both the non-covalently and covalently functionalized CNTs through the π-π stacking and NH⋯π interactions. The planar structure of isoniazid and hydrophobic nature of CNT promote the π-π stacking interactions. The amine group present in the isoniazid enables the NH⋯π interaction with the delocalized π electron cloud of CNT.

  3. The 8.2 kyr event recorded at high resolution by a speleothem from the Northern French Alps

    NASA Astrophysics Data System (ADS)

    Couchoud, Isabelle; Drysdale, Russell; Hellstrom, John; Perrette, Yves

    2016-04-01

    Continental records of Holocene climate variability in the Alps are scarce and they rarely document the "8.2 kyr event". Several reasons have been proposed: records do not have sufficient resolution, are not precisely dated or the proxies are not sufficiently sensitive to climate variations associated with this event. The European records of adequate resolution generally allow the identification of an anomaly but its characterisation is unclear: it seems that the event has triggered significant impacts only for a few decades and mainly expressed in winter (whereas most archives are more sensitive to summer conditions). Thus, the detailed characterisation of the impacts of this event requires records with sub-annual resolution and preferably sensitive to winter conditions. Here we present a multi-proxy, high-resolution analysis of this event, as recorded by a stalagmite of the Bauges massif (Northern French Alps), at ~1400 m altitude. Comparison of these results with other regional and distant data allows for a discussion about climatic impacts and teleconnections at this time.

  4. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present

    PubMed Central

    Hoff, Ulrike; Rasmussen, Tine L.; Stein, Ruediger; Ezat, Mohamed M.; Fahl, Kirsten

    2016-01-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland–Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean. PMID:27456826

  5. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present.

    PubMed

    Hoff, Ulrike; Rasmussen, Tine L; Stein, Ruediger; Ezat, Mohamed M; Fahl, Kirsten

    2016-01-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean. PMID:27456826

  6. Thermal isolation of Campbell Plateau, New Zealand, by the Antarctic Circumpolar Current over the past 130 kyr

    NASA Astrophysics Data System (ADS)

    Neil, Helen L.; Carter, Lionel; Morris, Michele Y.

    2004-12-01

    Campbell Plateau occupies a key position in the southwest Pacific sector of the Southern Ocean. The plateau confines and steers the Antarctic Circumpolar Current (ACC) along its flanks, isolating the Subantarctic plateau from cold polar waters. Oxygen and carbon isotope records from Campbell Plateau cores provide new records of water mass stratification for the past 130 kyr. During glacial climes, strengthening of the Subantarctic Front (SAF) caused waters over the plateau flanks to be deeply mixed and ˜3°C cooler. Waters of the plateau interior remained stratified and isolated from the cold southern waters. In the west, waters cooled markedly (˜4°C) owing to reduced entrainment of Tasman Sea water. Marked cooling also occurred north of Campbell Plateau under increased entrainment of polar water by a branch of the SAF. The ACC remained along the flanks of Campbell Plateau during the last interglacial, when interior waters were stratified and warmer by ˜1°C than now.

  7. Variability of Indian summer monsoon over the past 252 kyr revealed by stalagmite record in Southwest China

    NASA Astrophysics Data System (ADS)

    Cai, Y.; Fung, I. Y.; Edwards, R.; An, Z.; Cheng, H.; Lee, J.

    2013-12-01

    Multiple proxies obtained from Arabian Sea sediments have revealed the variability of Indian summer Monsoon (ISM) on time scale of 100-105 years. These proxies mainly capture summertime winds over the Arabian Sea and our understanding of Indian summer monsoon precipitation variability; and the relationship between paleo-ISM and paleo East Asia summer monsoon (EASM) lacks precise articulation, however, due to the scarcity of high-resolution precipitation records spanning a glacial-interglacial cycle. Here, we present an absolutely-dated oxygen isotope record from stalagmites in Xiaobailong (XBL) cave, southwestern China, that documents the variability in local precipitation and the ISM for the past 252,000 years. This record is dominated by 23-kyr precessional cycles punctuated by prominent millennial-scale oscillations that are synchronous with Heinrich events in the North Atlantic. It also shows clear glacial-interglacial variations that are consistent with marine and other terrestrial proxies. The distinct glacial-interglacial range in XBL δ18O is larger than that of speleothem records from eastern China. Corroborated with results from an isotope-enabled global climate model, we hypothesize that these dissimilarities may reflect the different responses of ISM and EASM to changes in global circulation and moisture source, in particular those caused by glacial-interglacial sea-land configuration changes as manifested by notable coastline shifts in the Western Pacific and Maritime Continent.

  8. Palaeomagnetic intensities from 14C-dated lava flows on the Big Island, Hawaii: 0-21 kyr

    USGS Publications Warehouse

    Pressling, Nicola; Laj, Carlo; Kissel, Catherie; Champion, Duane E.; Gubbins, David

    2006-01-01

    Thellier–Thellier experiments were carried out on 216 lava samples collected by the USGS on the Big Island. 35 individual flows from the Kilauea, Mauna Loa and Hualalai volcanoes are represented and independent radiocarbon dating of the flows yields absolute ages ranging from 290 to 20,240 yrs old. The palaeomagnetic analysis was carried out at the Laboratoire des Sciences du Climat et de l'Environnement in Gif-sur-Yvette, France, in two custom built, large capacity furnaces that have been specifically designed to minimise oxidation. The temperature steps were adapted to accommodate the characteristic loss of magnetisation at low temperatures seen in the Curie balance results and the use of half-size samples allowed secondary experiments to be carried out where necessary. The strict PICRIT-03 selection criteria were rigorously applied to the data and a high success rate of 53% has been achieved on a sample level. The flow averaged results almost double the existing 14C-dated palaeointensity dataset for this time window and confirm a period of high intensity over the past 4 kyr preceded by a period in which the dipole moment was weaker. However, the values attained in this study are on average higher than previously published data; reliability of these values is discussed.

  9. Export production in the subarctic North Pacific over the last 800 kyrs: No evidence for iron fertilization?

    USGS Publications Warehouse

    Kienast, S.S.; Hendy, I.L.; Crusius, J.; Pedersen, Thomas F.; Calvert, S.E.

    2004-01-01

    The subarctic North Pacific is a high nitrate-low chlorophyll (HNLC) region, where phytoplankton growth rates, especially those of diatoms, are enhanced when micro-nutrient Fe is added. Accordingly, it has been suggested that glacial Fe-laden dust might have increased primary production in this region. This paper reviews published palaeoceanographic records of export production over the last 800 kyrs from the open North Pacific (north of ???35??N). We find different patterns of export production change over time in the various domains of the North Pacific (NW and NE subarctic gyres, the marginal seas and the transition zone). However, there is no compelling evidence for an overall increase in productivity during glacials in the subarctic region, challenging the paradigm that dust-born Fe fertilization of this region has contributed to the glacial draw down of atmospheric CO2. Potential reasons for the lack of increased glacial export production include the possibility that Fe-fertilization rapidly drives the ecosystem towards limitation by another nutrient. This effect would have been exacerbated by an even more stable mixed layer compared to today. ?? The Oceanographic Society of Japan.

  10. A paleomagnetic and relative paleointensity record from the Argentine Basin (western South Atlantic Ocean) for the last ~125 kyrs

    NASA Astrophysics Data System (ADS)

    Heil, C. W., Jr.; Stoner, J. S.; St-Onge, G.; King, J. W.

    2015-12-01

    The paucity of paleomagnetic records from the western South Atlantic Ocean presents a significant gap in our understanding of the spatial variations in geomagnetic field dynamics as they relate to the occurrence of geomagnetic excursions and changes in field strength. As such, high quality records from this region can help build upon Holocene observations and extend the geographic and temporal data coverage for spherical harmonic models. To that end, we present paleomagnetic directional (inclination) and strength (relative paleointensity) records from two cores from the Argentine Basin (RC11-49 and RC16-88). Although the cores were collected more than 40 years ago, the sediments appear to hold a stable remanence and reliable magnetic directions, as evidenced by their reproducibility between the two cores that are separated by ~25 km. The records show evidence of 4 excursional features in the uppermost 16-m of the sediments from the basin. A comparison of the relative paleointensity records from these cores to the South Atlantic Paleointensity Stack (SAPIS) (Stoner et al., 2002) and the relative paleointensity record from ODP Site 1089 (Stoner et al., 2003) indicate that the sediments reliably record relative changes in geomagnetic field intensity and suggests that the longest record (RC11-49) spans the last ~125 kyrs. Our results indicate that the sediments of the Argentine Basin are an important sedimentary archive of geomagnetic field behavior and strength at least through the Holocene and Late Pleistocene and highlight the need for further studies of cores within the basin.

  11. A pervasive link between Antarctic ice core and subarctic Pacific sediment records over the past 800 kyrs

    NASA Astrophysics Data System (ADS)

    Jaccard, S. L.; Galbraith, E. D.; Sigman, D. M.; Haug, G. H.

    2010-01-01

    Recently developed XRF core-scanning methods permit paleoceanographic reconstructions on timescales similar to those of ice-core records. We have investigated the distribution of biogenic barium (Ba/Al), opal and carbonate (Ca/Al) in a sediment core retrieved from the abyssal subarctic Pacific (ODP 882, 50°N, 167°E, 3244 m) over an interval that spans the full length of the EPICA Dome C (EDC) ice-core record. Ba/Al and biogenic opal show a strong resemblance to the EDC δD and CO 2, with generally high concentrations during interglacials and lower values during ice ages of the past 800 kyrs. The sedimentary Ba/Al and biogenic opal are most easily interpreted as indicating a reduced sinking flux of organic matter from the surface ocean during cold periods. The Ba/Al maxima during peak interglacials are accompanied by transient Ca/Al peaks in these otherwise carbonate-devoid sediments, which are best explained by a deepening of the calcite lysocline, presumably due to reduced storage of respired CO 2 in the deep North Pacific. For most of the "luke-warm" interglacials noted between 420 and 750 ka in EDC, the Ba/Al peaks in ODP 882 are also lower, further strengthening the evidence for a simple physical link between global climate and the biogeochemistry of the subarctic Pacific.

  12. Statistical analysis of seismo-ionospheric anomalies related to Ms > 5.0 earthquakes in China by GPS TEC

    NASA Astrophysics Data System (ADS)

    Ke, Fuyang; Wang, Yueliang; Wang, Xinzhi; Qian, Hui; Shi, Chuang

    2016-01-01

    To quantitatively study the relationship between earthquakes and ionospheric total electron content (TEC) anomalies, 24 5.0 < Ms < 8.0 earthquakes in China from 2003 to 2013 were selected and the global ionosphere maps from the International GNSS Service 20 days before and after each earthquake were analyzed. Significant negative and positive total electron content anomalies were observed; the averages of the absolute anomalies before the earthquakes were higher than after the earthquakes. The anomalies were not all negative or positive 5 days before the earthquakes and were not continuous. Anomalous areas were found close to the epicenters in all the earthquakes at the time of the earthquake, showing vortex distributions. The absolute Dst and Kp indexes of the 7.0 < Ms < 8.0 earthquakes were more than 50 nT and 4, respectively, in the 20 days period before most of the earthquakes. Our study confirms the premise that extreme solar and geomagnetic activities may lead to earthquakes. This study also showed that the negative and positive TEC anomalies during Ms > 5.0 earthquakes are not continuous and regular. The TEC anomalies were not proportional to the earthquake magnitudes and all the anomalies on the day of the earthquake at the epicenters were not significantly higher or lower than on other days.

  13. Sediment Cd and Mo accumulation in the oxygen-minimum zone off western Baja California linked to global climate over the past 52 kyr

    USGS Publications Warehouse

    Dean, W.E.; Zheng, Yen; Ortiz, J.D.; VanGeen, A.

    2006-01-01

    Concentrations of organic carbon (orgC), cadmium (Cd), and molybdenum (Mo) were measured in two sediment cores raised from depths of 430 and 700 m within the oxygen-minimum zone (OMZ) off southern Baja California at a temporal resolution of e10.5 kyr over the past 52 kyr. These records are supplemented with diffuse spectral reflectance (DSR) measurements obtained on board ship soon after collection at a resolution of e10.05 kyr. In the core from 700 m depth, a component extracted from the DSR data and the three geochemical proxies generally vary in concert with each other and over a wide range (4-22% orgC; 1-40 mg/kg Cd; 5-120 mg/kg Mo). Intervals of increased orgC, Cd, and Mo accumulation generally correspond to warm periods recorded in the oxygen-isotopic composition of Greenland ice, with the exception of the Bolling/Allerod which is only weakly expressed off Baja California. Concentrations of the biogenic proxies are higher in the core from 430 m depth, but erratic sediment accumulation before 15 ka precludes dating of the older intervals that are laminated and contain elevated orgC, Cd, and Mo concentrations. The new data provide further evidence of an intimate teleconnection between global climate and the intensity of the OMZ and/or productivity along the western margin of North America. On the basis of a comparison with Cd and Mo records collected elsewhere in the region, we conclude that productivity may actually have varied off southern Baja California by no more than a factor of 2 over the past 52 kyr. Copyright 2006 by the American Geophysical Union.

  14. Age-depth model of the past 630 kyr for Lake Ohrid (FYROM/Albania) based on cyclostratigraphic analysis of downhole gamma ray data

    NASA Astrophysics Data System (ADS)

    Baumgarten, H.; Wonik, T.; Tanner, D. C.; Francke, A.; Wagner, B.; Zanchetta, G.; Sulpizio, R.; Giaccio, B.; Nomade, S.

    2015-12-01

    Gamma ray (GR) fluctuations and potassium (K) values from downhole logging data obtained in the sediments of Lake Ohrid from 0 to 240 m below lake floor (b.l.f). correlate with fluctuations in δ18O values from the global benthic isotope stack LR04 (Lisiecki and Raymo, 2005). GR and K values are considered a reliable proxy to depict glacial-interglacial cycles, with high clastic input during cold and/or drier periods and high carbonate precipitation during warm and/or humid periods at Lake Ohrid. Spectral analysis was applied to investigate the climate signal and evolution over the length of the borehole. Linking downhole logging data with orbital cycles was used to estimate sedimentation rates and the effect of compaction was compensated for. Sedimentation rates increase on average by 14 % after decompaction of the sediment layers and the mean sedimentation rates shift from 45 cm kyr-1 between 0 and 110 m to 30 cm kyr-1 from 110 to 240 m b.l.f. Tuning of minima and maxima of gamma ray and potassium values versus LR04 extrema, in combination with eight independent tephrostratigraphical tie points, allows establishing of a robust age model for the downhole logging data over the past 630 kyr.

  15. The 15q11.2 BP1–BP2 Microdeletion Syndrome: A Review

    PubMed Central

    Cox, Devin M.; Butler, Merlin G.

    2015-01-01

    Patients with the 15q11.2 BP1–BP2 microdeletion can present with developmental and language delay, neurobehavioral disturbances and psychiatric problems. Autism, seizures, schizophrenia and mild dysmorphic features are less commonly seen. The 15q11.2 BP1–BP2 microdeletion involving four genes (i.e., TUBGCP5, CYFIP1, NIPA1, NIPA2) is emerging as a recognized syndrome with a prevalence ranging from 0.57%–1.27% of patients presenting for microarray analysis which is a two to four fold increase compared with controls. Review of clinical features from about 200 individuals were grouped into five categories and included developmental (73%) and speech (67%) delays; dysmorphic ears (46%) and palatal anomalies (46%); writing (60%) and reading (57%) difficulties, memory problems (60%) and verbal IQ scores ≤75 (50%); general behavioral problems, unspecified (55%) and abnormal brain imaging (43%). Other clinical features noted but not considered as common were seizures/epilepsy (26%), autism spectrum disorder (27%), attention deficit disorder (ADD)/attention deficit hyperactivity disorder (ADHD) (35%), schizophrenia/paranoid psychosis (20%) and motor delay (42%). Not all individuals with the deletion are clinically affected, yet the collection of findings appear to share biological pathways and presumed genetic mechanisms. Neuropsychiatric and behavior disturbances and mild dysmorphic features are associated with genomic imbalances of the 15q11.2 BP1–BP2 region, including microdeletions, but with an apparent incomplete penetrance and variable expressivity. PMID:25689425

  16. A SCALE 5.0 Reactor Physics Assessment using the Module TRITON against Mixed Oxide (MOX) OECD/NEA Benchmarks

    SciTech Connect

    Saccheri, J.G.B.; Diamond, D.J.

    2006-07-01

    Reactor physics numerical benchmarks have been performed at the Brookhaven National Laboratory (BNL) with the software package SCALE 5.0 and its TRITON module to assess their capability to predict neutronics parameters for mixed oxide (MOX) fuels. The results of such calculations are herein presented. Specifically, BNL results for neutron multiplication factors (kINF), neutron fluxes and fuel burnup have been added to published OECD/NEA benchmarks for MOX fuels and particular emphasis has been given to the impact of cross-section libraries and their energy structure on the results. Among the OECD/NEA published benchmarks two have been considered here: the first one models a fuel pin surrounded by moderator, in which two different MOX fuels can be introduced, and for each one of them kINF and neutron fluxes as a function of burnup are calculated. The second one includes both a fuel pin case and a macro-cell case (a heterogeneous 30 by 30 configuration of fuel pins), for which the void coefficient is determined by calculating kINF at zero burnup as a function of moderation. The calculations are repeated for several combinations of MOX and uranium oxide fuels using several different cross-section libraries. The final results have been compared with each other. This study shows that SCALE 5.0 (with TRITON) overall performs in line with the other codes in the benchmark, but the results are dependent on the energy group structure of the cross section libraries used. For instance, when fissile plutonium is increased in the fuel, TRITON results become slightly divergent with burnup (with respect to the other codes in the benchmark) and if the standard 44-group library provided with SCALE 5.0 is used void coefficient calculations become inadequate for very low void (below 10% of the operating value of moderator density). Moreover, the prediction capabilities of the code are shown to be dependent on the MOX fuel enrichment and the MOX isotopic composition. (authors)

  17. Asiago spectroscopic classification of ASASSN-16bp

    NASA Astrophysics Data System (ADS)

    Tomasella, L.; Pastorello, A.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Ochner, P.; Tartaglia, L.; Terreran, G.; Turatto, M.

    2016-02-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of ASASSN-16bp ( = AT 2016adq), discovered by All Sky Automated Survey for SuperNovae ASAS-SN (see Shappee et al. 2014, ApJ, 788, 48 and http://www.astronomy.ohio-state.edu/~assassin/index.shtml ), in CGCG 336-041 (Atel #8666) The observation was performed with the Asiago 1.82 m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.4 nm). Name | Discovery UT | Obs. Date UT |z | Type | Phase |Notes ASASSN-16bp | 20160209.61 | 20160211.11 |0.034194 | Ia | ~10d | (1) (1) Also known as SN2016adq in CGCG 336-041 (z=0.034194, d=145 Mpc, via NED).

  18. A statistical study on ELF-whistlers/emissions and M ≥ 5.0 earthquakes in Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, J. Y.; Wang, K.; Chen, C. H.; Yang, W. H.; Yen, Y. H.; Chen, Y. I.; Hatorri, K.; Su, H. T.; Hsu, R. R.; Chang, C. H.

    2013-06-01

    In this paper, we conduct statistical approaches to study the potential relation between ELF-whistlers/emissions below 100 Hz and 20 M ≥ 5.0 earthquakes occurred in Taiwan in the period from 26 August 2003 to 13 July 2004. Occurrence ratios of the ELF-whistler and ELF-emission of the entire study period are computed as the reference backgrounds. Our study shows that the ELF-whistlers and ELF-emissions during the earthquake period appear less and more frequently than their associated backgrounds, respectively. For the ELF-emission, the larger earthquakes generally yield the higher occurrence ratios. The statistical analyses confirm that the occurrence ratios of the ELF-emission significantly enhance 5-7 days before the earthquakes and are proportional to the earthquake magnitude but inversely to the distance from the observatory to the epicenter.

  19. NCG 5.0: updates of a manually curated repository of cancer genes and associated properties from cancer mutational screenings

    PubMed Central

    An, Omer; Dall'Olio, Giovanni M.; Mourikis, Thanos P.; Ciccarelli, Francesca D.

    2016-01-01

    The Network of Cancer Genes (NCG, http://ncg.kcl.ac.uk/) is a manually curated repository of cancer genes derived from the scientific literature. Due to the increasing amount of cancer genomic data, we have introduced a more robust procedure to extract cancer genes from published cancer mutational screenings and two curators independently reviewed each publication. NCG release 5.0 (August 2015) collects 1571 cancer genes from 175 published studies that describe 188 mutational screenings of 13 315 cancer samples from 49 cancer types and 24 primary sites. In addition to collecting cancer genes, NCG also provides information on the experimental validation that supports the role of these genes in cancer and annotates their properties (duplicability, evolutionary origin, expression profile, function and interactions with proteins and miRNAs). PMID:26516186

  20. [5-0xoproline (pyroglutamic acid) acidosis and acetaminophen- a differential diagnosis in high anion gap metabolic acidosis].

    PubMed

    Weiler, Stefan; Bellmann, Romuald; Kullak-Ublick, Gerd A

    2015-12-01

    Rare cases of high anion gap metabolic acidosis during long-term paracetamol administration in therapeutic doses with causative 5-oxoproline (pyroglutamic acid} accumulation have been reported. Other concomitant risk factors such as malnutrition, alcohol abuse, renal or hepatic dysfunction, comedication with flue/oxacillin, vigabatrin, netilmicin or sepsis have been described. The etiology seems to be a drug-induced reversible inhibition of glutathione synthetase or 5-oxoprolinase leading to elevated serum and urine levels of 5-oxoproline. Other more frequent differential diagnoses, such as intoxications, ketoacidosis or lactic acidosis should be excluded. Causative substances should be stopped. 5-oxoproline concentrations in urine can be quantified to establish the diagnosis. Adverse drug reactions, which are not listed or insufficiently described in the respective Swiss product information, should be reported to the regional pharmacovigilance centres for early signal detection. 5-0 xoproline acidosis will be integrated as a potential adverse drug reaction in the Swiss product information for paracetamol. PMID:26654818

  1. A Statistical Study of Lightning Activities and M ≥ 5.0 Earthquakes in Taiwan During 1993-2004

    NASA Astrophysics Data System (ADS)

    Liu, J. Y.; Chen, Y. I.; Huang, C. H.; Ho, Y. Y.; Chen, C. H.

    2015-11-01

    In this study, to see whether or not lightning activities are related to earthquakes, we statistically examine lightning activities 30 days before and after 78 land and 230 sea M ≥ 5.0 earthquakes in Taiwan during the 12-year period of 1993-2004. Lightning activities versus the location, depth, and magnitude of earthquakes are investigated. Results show that lightning activities tend to appear around the forthcoming epicenter and are significantly enhanced a few, especially 17-19, days before the M ≥ 6.0 shallow (depth D ≤ 20 km) land earthquakes. Moreover, the size of the area around the epicenter with the statistical significance of lightning activity enhancement is proportional to the earthquake magnitude.

  2. Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Version 5.0: Data loading manual. Volume 10

    SciTech Connect

    VanHorn, R.L.; Wolfram, L.M.; Fowler, R.D.; Beck, S.T.; Smith, C.L.

    1995-04-01

    The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) suite of programs can be used to organize and standardize in an electronic format information from probabilistic risk assessments or individual plant examinations. The Models and Results Database (MAR-D) program of the SAPHIRE suite serves as the repository for probabilistic risk assessment and individual plant examination data and information. This report demonstrates by examples the common electronic and manual methods used to load these types of data. It is not a stand alone document but references documents that contribute information relative to the data loading process. This document provides a more detailed discussion and instructions for using SAPHIRE 5.0 only when enough information on a specific topic is not provided by another available source.

  3. AMDTreat 5.0+ with PHREEQC titration module to compute caustic chemical quantity, effluent quality, and sludge volume

    USGS Publications Warehouse

    Cravotta, Charles A., III; Means, Brent P; Arthur, Willam; McKenzie, Robert M; Parkhurst, David L.

    2015-01-01

    Alkaline chemicals are commonly added to discharges from coal mines to increase pH and decrease concentrations of acidity and dissolved aluminum, iron, manganese, and associated metals. The annual cost of chemical treatment depends on the type and quantities of chemicals added and sludge produced. The AMDTreat computer program, initially developed in 2003, is widely used to compute such costs on the basis of the user-specified flow rate and water quality data for the untreated AMD. Although AMDTreat can use results of empirical titration of net-acidic or net-alkaline effluent with caustic chemicals to accurately estimate costs for treatment, such empirical data are rarely available. A titration simulation module using the geochemical program PHREEQC has been incorporated with AMDTreat 5.0+ to improve the capability of AMDTreat to estimate: (1) the quantity and cost of caustic chemicals to attain a target pH, (2) the chemical composition of the treated effluent, and (3) the volume of sludge produced by the treatment. The simulated titration results for selected caustic chemicals (NaOH, CaO, Ca(OH)2, Na2CO3, or NH3) without aeration or with pre-aeration can be compared with or used in place of empirical titration data to estimate chemical quantities, treated effluent composition, sludge volume (precipitated metals plus unreacted chemical), and associated treatment costs. This paper describes the development, evaluation, and potential utilization of the PHREEQC titration module with the new AMDTreat 5.0+ computer program available at http://www.amd.osmre.gov/.

  4. Precessional changes in the western equatorial Pacific Hydroclimate: A 240 kyr marine record from the Halmahera Sea, East Indonesia

    NASA Astrophysics Data System (ADS)

    Dang, Haowen; Jian, Zhimin; Kissel, Catherine; Bassinot, Franck

    2015-01-01

    the precession band, an interhemispheric antiphase pattern in the tropical hydroclimate is supported by many paleorecords, and optimally explained by the forcing of precessional insolation change. However, scenarios within the western equatorial Pacific (WEP), which plays the role of the ascending center of atmospheric convection, remain poorly determined. In this study, a marine sediment core from the Halmahera Sea, East Indonesia, was analyzed with high-resolution XRF scanning, quantitative discrete XRF, and ICP-AES/MS measurements. The terrigenous fractions in this core are constrained by their trace elemental characteristics to be locally sourced from Halmahera Island, and hence reflect variations in the local riverine runoff and precipitation. On this basis, a continuous record of precipitation changes of the western equatorial Pacific was reconstructed with multidecadal resolution over the last ˜240 ka, using an age model established by the correlation between an adjusted ice volume model and benthic δ18O constrained by 14C dating. The records of terrigenous input show a dominant ˜23 kyr periodicity with a 90°˜100° phase lag to the boreal summer (i.e., in-phase with the boreal autumn) insolation change. This pattern can be explained by the variability in the convective activity over the WEP, which might be primarily controlled by precessional changes in the El Niño and Southern Oscillation (ENSO) system. A dynamic linkage is implied between the precessional variations in the convective activity in the WEP and the East Asian and Australia-Indonesian summer monsoons (EASM and AISM), in the sense of their distinct stable phase relationship to precession.

  5. Links between carbonate productivity and ENSO variability in the southern California Current System for the past 2 Kyrs

    NASA Astrophysics Data System (ADS)

    Abella-Gutiérrez, J. L.; Herguera, J. C.

    2014-12-01

    San Lázaro Basin (SLB) is a suboxic basin characteristic for its very high sedimentation rates (1mm/yr) and is located in the dynamic southern boundary of the California Current System (CCS). This southern boundary of the CCS generally extends further south during spring into early summer and retracts towards the north during fall and winter, and this pattern is further amplified or reduced on different time scales, (e.i. interannual timescales by El Niño and La Niña events, or multidecadal ones by the Pacific Decadal Oscillation (PDO)). These oceanographic conditions are related with important differences in the base of the food chain; when the boundary migrates to northern latitudes, the presence of relatively warmer tropical and subtropical waters further stratify the water column, a period when coccolithophorids dominate the microplankton web structure. On the other side, diatoms flourish when the wind-driven circulation expand the subarctic water masses of the CCS to the south and upwelling cells are generated. We find in our cores XRF Ca counts (1 mm resolution) highly correlate with CaCO3 measurements (R=0.56), this last one showing a general decreasing trend over the past 2 Kyrs. The Ca spectrum analysis shows significant peaks for periods centered at 28, 40, 60, 120 yr. The centennial mode of variability of the Ca record shows correlations with Drought area Index from North America. When the variance of this mode is considered, similarities arises with intensity and number of ENSO events from Equatorial archives. Decadal variations of the record are highly correlated (R>0.8) with instrumental measurements of Kaplan sea surface temperature, and the PDO. We will discuss the implications of these periods in the carbonate record and the links between them and other paleoceanographic records in the Pacific.

  6. Heavy mineral variation in the deep sea sediment of southeastern Arabian Sea during the past 32 kyr

    NASA Astrophysics Data System (ADS)

    Akaram, Vaseem; Das, S. S.; Rai, A. K.; Mishra, Gaurav

    2015-03-01

    The present study is based on heavy mineral assemblages (HM) of top 104-cm thick section of gravity core SK 221 (Lat. 8∘7.12'N; Long. 73∘16.38'E and water depth - 2188 m) located near the Chagos-Laccadive Ridge in the southeastern Arabian Sea to evaluate the provenance and paleoenvironmental changes during the last 32 kyr. The biogenic carbonate, acid insoluble residue, magnetic susceptibility, total organic carbon (TOC) and clay based humidity index, i.e., kaolinite/illite ratio are also utilized to correlate with the above paleoenvironmental changes. Ilmenite, garnet, staurolite, pyroxenes, andalusite and zircon are the dominant HM with moderate to low ZTR (zircon-tourmaline-rutile) index indicating instability of the sediments and rapid erosion in the source region. The characteristic HM suggest their mixed sources from the basic igneous, gneisses/granites, high grade metamorphic rocks and sandstones occurring mainly in the western and southwestern India. The temporal variations of HM, AIR (acid insoluble residue), MS (magnetic susceptibility), biogenic carbonate and Corg (TOC) during preglacial and early Holocene suggest intensive weathering, erosion, and transportation of terrigenous detritus from continental region by fluvial processes and summer monsoon led high biogenic productivity, respectively. The convective mixing of waters due to intense winter monsoon resulted in very high biogenic carbonate content during the early stages of glacial period. The HM and associated proxies indicated that the winter monsoons of Heinrich (H3, H2, and H1) and Younger Dryas (YD) events and summer monsoons of Bølling/Allerød (BA) event were not strong enough to bring drastic changes in the above parameters.

  7. Hypoxia-driven variations in iron and manganese shuttling in the Baltic Sea over the past 8 kyr

    NASA Astrophysics Data System (ADS)

    Lenz, Conny; Jilbert, Tom; Conley, Daniel J.; Slomp, Caroline P.

    2015-10-01

    The Baltic Sea has experienced three major intervals of bottom water hypoxia following the intrusion of seawater circa 8 kyr ago. These intervals occurred during the Holocene Thermal Maximum (HTM), Medieval Climate Anomaly (MCA), and during recent decades. Here we show that sequestration of both Fe and Mn in Baltic Sea sediments generally increases with water depth, and we attribute this to shelf-to-basin transfer ("shuttling") of Fe and Mn. Burial of Mn in slope and basin sediments was enhanced following the lake-brackish/marine transition at the beginning of the hypoxic interval during the HTM. During hypoxic intervals, shelf-to-basin transfer of Fe was generally enhanced but that of Mn was reduced. However, intensification of hypoxia within hypoxic intervals led to decreased burial of both Mn and Fe in deep basin sediments. This implies a nonlinearity in shelf Fe release upon expanding hypoxia with initial enhanced Fe release relative to oxic conditions followed by increased retention in shelf sediments, likely in the form of iron sulfide minerals. For Mn, extended hypoxia leads to more limited sequestration as Mn carbonate in deep basin sediments, presumably because of more rapid reduction of Mn oxides formed after inflows and subsequent escape of dissolved Mn to the overlying water. Our Fe records suggest that modern Baltic Sea hypoxia is more widespread than in the past. Furthermore, hypoxia-driven variations in shelf-to-basin transfer of Fe may have impacted the dynamics of P and sulfide in the Baltic Sea thus providing potential feedbacks on the further development of hypoxia.

  8. Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool

    NASA Astrophysics Data System (ADS)

    Bolliet, Timothé; Holbourn, Ann; Kuhnt, Wolfgang; Laj, Carlo; Kissel, Catherine; Beaufort, Luc; Kienast, Markus; Andersen, Nils; Garbe-Schönberg, Dieter

    2011-02-01

    We present sea surface, upper thermocline, and benthic δ18O data, as well as temperature and paleoproductivity proxy data, from the International Marine Global Change Study Program (IMAGES) Core MD06-3067 (6°31‧N, 126°30‧E, 1575 m water depth), located in the western equatorial Pacific Ocean within the flow path of the Mindanao Current. Our records reveal considerable glacial-interglacial and suborbital variability in the Mindanao Dome upwelling over the last 160 kyr. Dome activity generally intensified during glacial intervals resulting in cooler thermocline waters, whereas it substantially declined during interglacials, in particular in the early Holocene and early marine oxygen isotope stage (MIS) 5e, when upwelling waters did not reach the thermocline. During MIS 3 and MIS 2, enhanced surface productivity together with remarkably low SST and low upper ocean thermal contrast provide evidence for episodic glacial upwelling to the surface, whereas transient surface warming marks periodic collapses of the Mindanao Dome upwelling during Heinrich events. We attribute the high variability during MIS 3 and MIS 2 to changes in the El Niño Southern Oscillation state that affected boreal winter monsoonal winds and upper ocean circulation. Glacial upwelling intensified when a strong cyclonic gyre became established, whereas El Niño-like conditions during Heinrich events tended to suppress the cyclonic circulation, reducing Ekman transport. Thus, our findings demonstrate that variations in the Mindanao Dome upwelling are closely linked to the position and intensity of the tropical convection and also reflect far-field influences from the high latitudes.

  9. High-latitude forcing of diatom productivity in the southern Agulhas Plateau during the past 350 kyr

    NASA Astrophysics Data System (ADS)

    Romero, O. E.; Kim, J.-H.; Bárcena, M. A.; Hall, I. R.; Zahn, R.; Schneider, R.

    2015-02-01

    The hydrography of the Indian-Atlantic Ocean gateway has been connected to high-latitude climate dynamics by oceanic and atmospheric teleconnections on orbital and suborbital timescales. A wealth of sedimentary records aiming at reconstructing the late Pleistocene paleoceanography around the southern African continent has been devoted to understanding these linkages. Most of the records are, however, clustered close to the southern South African tip, with comparatively less attention devoted to areas under the direct influence of frontal zones of the Southern Ocean/South Atlantic. Here we present data of the composition and concentration of the diatom assemblage together with bulk biogenic content and the alkenone-based sea surface temperature (SST) variations for the past 350 kyr in the marine sediment core MD02-2588 (approximately 41°S, 26°E) recovered from the southern Agulhas Plateau. Variations in biosiliceous productivity show a varying degree of coupling with Southern Hemisphere paleoclimate records following a glacial-interglacial cyclicity. Ecologically well-constrained groups of diatoms record the glacial-interglacial changes in water masses dynamics, nutrient availability, and stratification of the upper ocean. The good match between the glacial maxima of total diatoms concentration, Chaetoceros spores abundance, and opal content with the maximum seasonal cover of Antarctic ice and the atmospheric dust records points to a dominant Southern Hemisphere forcing of diatom production. Suborbital variability of SST suggests rapid latitudinal migrations of the Subtropical Front and associated water masses over the southern Agulhas Plateau, following millennial contractions and expansions of the subtropical gyres. Warmings of the upper ocean over site MD02-2588 during terminations IV to I occurred earlier than that in the Antarctic Vostok, which is indicative of a Northern Hemisphere lead. Our multiparameter reconstruction highlights how high

  10. Temperature variations in Greenland from 10 to 110 kyr b2k derived from the NGRIP ice core

    NASA Astrophysics Data System (ADS)

    Kindler, Philippe; Leuenberger, Markus; Landais, Amaelle; Guillevic, Myriam

    2013-04-01

    During the last ice age dramatic temperature variations of up to 16 °C took place in Greenland which are now known as Dansgaard-Oeschger-events (DO-events). They most probably originate from the North Atlantic oceanic and atmospheric circulation system and are characterised by an abrupt warming within decades followed by a gradual cooling over hundreds to thousands of years. We have determined local temperature variations for DO-event 1 to 25 in Greenland based on δ15N measurements from the NorthGRIP ice core, corresponding to the period from 10 to 110 kyr b2k. The record is a composite of measurements from two laboratories, Laboratoire des Sciences du Climat et de l'Environnement, Paris (DO 18 to 25) and the Climate and Environmental Physics Division of the Physics Institute of the University of Bern (DO 1 to 17) with new measurements from the beginning of the Holocene to DO 8. Temperature variations were reconstructed by reproducing the measured 15N/14N ratio of air enclosed in ice bubbles by the firn densification and heat diffusion model from Schwander. The reconstruction show temperature amplitudes for the DO-events ranging from 5 to 16 °C, thereby the corresponding rates of change can exceed 0.5 °C/decade. In order get an agreement between measured δ15N, Δdepth and Δage values with their modelled analogues, a lower accumulation rate than the one associated with the used ss09sea06bm1 time scale had to be assumed. We had to reduce the accumulation rate time dependently by 0 to nearly 40% with a mean reduction over the whole time period of 16%. With these adjustments both the Δdepth and the Δage values agree between model and measurements.

  11. Nephrotoxicity of selectively deuterated and methylated analogues of Tris-BP and Bis-BP in the rat.

    PubMed

    Søderlund, E J; Omichinski, J G; Dahl, J E; Nelson, S D; Dybing, E

    1988-03-01

    Selectively deuterated and methylated analogues of the flame retardant tris(2,3-dibromopropyl)phosphate (Tris-BP) and its nephrotoxic metabolite bis(2,3-dibromopropyl)phosphate (Bis-BP) were compared to Tris-BP and Bis-BP in inducing acute renal damage in rats. None of the deuterated Tris-BP or Bis-BP analogues significantly altered morphological evidence of nephrotoxicity compared to the protio compounds. On the other hand, some of the selectively methylated analogues were much less nephrotoxic. Although the C1-methyl analogues of both Tris-BP and Bis-BP were as potent nephrotoxicants as Tris-BP and Bis-BP, respectively, neither the C2-methyl nor the C3-methyl analogues were significantly nephrotoxic. Interestingly, whereas the 3,4-dibromobutyl homologue of Tris-BP was not nephrotoxic, the corresponding 3,4-dibromobutyl-Bis homologue was as nephrotoxic as Bis-BP. Additional investigations with treatments that are known to decrease nephrotoxicity caused by several halogenated alkenes, showed that L-(alpha S,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (AT-125) and aminooxyacetic acid were without effects on Tris-BP induced renal damage. Probenecid pretreatment led to a reduction in Tris-BP and Bis-BP tubular necrosis, these effects may be related to inhibition of Bis-BP uptake in the kidney. It appears that the cysteine conjugate beta-lyase pathway is not involved in the generation of nephrotoxic metabolites of Tris-BP. PMID:3375186

  12. Nuclear Thermal Rocket/Vehicle Characteristics And Sensitivity Trades For NASA's Mars Design Reference Architecture (DRA) 5.0 Study

    NASA Technical Reports Server (NTRS)

    Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

    2009-01-01

    This paper summarizes Phase I and II analysis results from NASA's recent Mars DRA 5.0 study which re-examined mission, payload and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal rocket (NTR) propulsion was again identified as the preferred in-space transportation system over chemical/aerobrake because of its higher specific impulse (I(sub sp)) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit (IMLEO) which is important for reducing the number of Ares-V heavy lift launches and overall mission cost. DRA 5.0 features a long surface stay (approximately 500 days) split mission using separate cargo and crewed Mars transfer vehicles (MTVs). All vehicles utilize a common core propulsion stage with three 25 klbf composite fuel NERVA-derived NTR engines (T(sub ex) approximately 2650 - 2700 K, p(sub ch) approximately 1000 psia, epsilon approximately 300:1, I(sub sp) approximately 900 - 910 s, engine thrust-toweight ratio approximately 3.43) to perform all primary mission maneuvers. Two cargo flights, utilizing 1-way minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crewed MTV during the next mission opportunity (approximately 26 months later). The cargo payload elements aerocapture (AC) into Mars orbit and are enclosed within a large triconicshaped aeroshell which functions as payload shroud during launch, then as an aerobrake and thermal protection system during Mars orbit capture and subsequent entry, descent and landing (EDL) on Mars. The all propulsive crewed MTV is a 0-gE vehicle design that utilizes a fast conjunction trajectory that allows approximately 6-7 month 1-way transit times to and from Mars. Four 12.5 kW(sub e) per 125 square meter rectangular photovoltaic arrays provide the crewed MTV with

  13. ITS version 5.0 : the integrated TIGER series of coupled electron/photon Monte Carlo transport codes.

    SciTech Connect

    Franke, Brian Claude; Kensek, Ronald Patrick; Laub, Thomas William

    2004-06-01

    ITS is a powerful and user-friendly software package permitting state of the art Monte Carlo solution of linear time-independent couple electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2)multigroup codes with adjoint transport capabilities, and (3) parallel implementations of all ITS codes. Moreover the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

  14. INTERLINE 5.0 -- An expanded railroad routing model: Program description, methodology, and revised user`s manual

    SciTech Connect

    Johnson, P.E.; Joy, D.S.; Clarke, D.B.; Jacobi, J.M.

    1993-03-01

    A rail routine model, INTERLINE, has been developed at the Oak Ridge National Laboratory to investigate potential routes for transporting radioactive materials. In Version 5.0, the INTERLINE routing algorithms have been enhanced to include the ability to predict alternative routes, barge routes, and population statistics for any route. The INTERLINE railroad network is essentially a computerized rail atlas describing the US railroad system. All rail lines, with the exception of industrial spurs, are included in the network. Inland waterways and deep water routes along with their interchange points with the US railroadsystem are also included. The network contains over 15,000 rail and barge segments (links) and over 13,000 stations, interchange points, ports, and other locations (nodes). The INTERLINE model has been converted to operate on an IBM-compatible personal computer. At least a 286 computer with a hard disk containing approximately 6 MB of free space is recommended. Enhanced program performance will be obtained by using arandom-access memory drive on a 386 or 486 computer.

  15. Fuel-rich catalytic combustion of Jet-A fuel-equivalence ratios 5.0 to 8.0

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Gracia-Salcedo, Carmen M.

    1989-01-01

    Fuel-rich catalytic combustion (E.R. greater than 5.0) is a unique technique for preheating a hydrocarbon fuel to temperatures much higher than those obtained by conventional heat exchangers. In addition to producing very reactive molecules, the process upgrades the structure of the fuel by the formation of hydrogen and smaller hydrocarbons and produces a cleaner burning fuel by removing some of the fuel carbon from the soot formation chain. With fuel-rich catalytic combustion as the first stage of a two stage combustion system, enhanced fuel properties can be utilized by both high speed engines, where time for ignition and complete combustion is limited, and engines where emission of thermal NO sub x is critical. Two-stage combustion (rich-lean) has been shown to be effective for NO sub x reduction in stationary burners where residence times are long enough to burn-up the soot formed in the first stage. Such residence times are not available in aircraft engines. Thus, the soot-free nature of the present process is critical for high speed engines. The successful application of fuel-rich catalytic combustion to Jet-A, a multicomponent fuel used in gas turbine combustors, is discusssed.

  16. Description of the Mountain Cloud Chemistry Program version of the PLUVIUS MOD 5. 0 reactive storm simulation model

    SciTech Connect

    Luecken, D.J.; Whiteman, C.D.; Chapman, E.G.; Andrews, G.L.; Bader, D.C.

    1987-07-01

    Damage to forest ecosystems on mountains in the eastern United States has prompted a study conducted for the US Environmental Protection Agency's Mountain Cloud Chemistry Program (MCCP). This study has led to the development of a numerical model called MCCP PLUVIUS, which has been used to investigate the chemical transformations and cloud droplet deposition in shallow, nonprecipitating orographic clouds. The MCCP PLUVIUS model was developed as a specialized version of the existing PLUVIUS MOD 5.0 reactive storm model. It is capable of simulating aerosol scavenging, nonreactive gas scavenging, aqueous phase SO/sub 2/ reactions, and cloud water deposition. A description of the new model is provided along with information on model inputs and outputs, as well as suggestions for its further development. The MCCP PLUVIUS incorporates a new method to determine the depth of the layer of air which flows over a mountaintop to produce an orographic cloud event. It provides a new method for calculating hydrogen ion concentrations, and provides updated expressions and values for solubility, dissociation and reaction rate constants.

  17. T4-like phage Bp7, a potential antimicrobial agent for controlling drug-resistant Escherichia coli in chickens.

    PubMed

    Zhang, Can; Li, Wenli; Liu, Wenhua; Zou, Ling; Yan, Chen; Lu, Kai; Ren, Huiying

    2013-09-01

    Chicken-pathogenic Escherichia coli is severely endangering the poultry industry in China and worldwide, and antibiotic therapy is facing an increasing problem of antibiotic resistance. Bacteriophages can kill bacteria with no known activity in human or animal cells, making them an attractive alternative to antibiotics. In this study, we present the characteristics of a novel virulent bacteriophage, Bp7, specifically infecting pathogenic multidrug-resistant E. coli. Phage Bp7 was isolated from chicken feces. Bp7 belongs to the family Myoviridae, possessing an elongated icosahedral head and contractile sheathed tail. It has a 168-kb double-stranded DNA genome. For larger yields, its optimal multiplicity of infection (MOI) to infect E. coli was about 0.001. The latent period was 10 to 15 min, and the burst size was 90 PFU/infected cell. It was stable both at pH 5.0 to 10.0 and at 40°C or 50°C for at least 1 h. Bp7 could infect 46% of pathogenic clinical E. coli strains. Bp7 harbored 791 open reading frames (ORFs) and 263 possible genes. Among the 263 genes, 199 possessed amino acid sequence identities with ORFs of phage T4, 62 had identities with other T4-like phages, and only one lacked any database match. The genome of Bp7 manifested obvious division and rearrangement compared to phages T4, JS98, and IME08. Bp7 is a new member of the "T4-like" genus, family Myoviridae. Its wide host range, strong cell-killing activity, and high stability to pH make it an alternative to antimicrobials for controlling drug-resistant E. coli in chickens. PMID:23835183

  18. South Asian summer monsoon variability during the last ˜54 kyrs inferred from surface water salinity and river runoff proxies

    NASA Astrophysics Data System (ADS)

    Gebregiorgis, D.; Hathorne, E. C.; Sijinkumar, A. V.; Nath, B. Nagender; Nürnberg, D.; Frank, M.

    2016-04-01

    The past variability of the South Asian Monsoon is mostly known from records of wind strength over the Arabian Sea while high-resolution paleorecords from regions of strong monsoon precipitation are still lacking. Here, we present records of past monsoon variability obtained from sediment core SK 168/GC-1, which was collected at the Alcock Seamount complex in the Andaman Sea. We utilize the ecological habitats of different planktic foraminiferal species to reconstruct freshwater-induced stratification based on paired Mg/Ca and δ18O analyses and to estimate seawater δ18O (δ18Osw). The difference between surface and thermocline temperatures (ΔT) and δ18Osw (Δδ18Osw) is used to investigate changes in upper ocean stratification. Additionally, Ba/Ca in G. sacculifer tests is used as a direct proxy for riverine runoff and sea surface salinity (SSS) changes related to monsoon precipitation on land. Our Δδ18Osw time series reveals that upper ocean salinity stratification did not change significantly throughout the last glacial suggesting little influence of NH insolation changes. The strongest increase in temperature gradients between the mixed layer and the thermocline is recorded for the mid-Holocene and indicate the presence of a significantly shallower thermocline. In line with previous work, the δ18Osw and Ba/Ca records demonstrate that monsoon climate during the LGM was characterized by a significantly weaker southwest monsoon circulation and strongly reduced runoff. Based on our data the South Asian Summer Monsoon (SAM) over the Irrawaddyy strengthened gradually after the LGM beginning at ∼18 ka. This is some 3 kyrs before an increase of the Ba/Ca record from the Arabian Sea and indicates that South Asian Monsoon climate dynamics are more complex than the simple N-S displacement of the ITCZ as generally described for other regions. Minimum δ18Osw values recorded during the mid-Holocene are in phase with Ba/Ca marking a stronger monsoon precipitation

  19. South Asian summer monsoon variability during the last ˜54 kyrs inferred from surface water salinity and river runoff proxies

    NASA Astrophysics Data System (ADS)

    Gebregiorgis, D.; Hathorne, E. C.; Sijinkumar, A. V.; Nath, B. Nagender; Nürnberg, D.; Frank, M.

    2016-04-01

    The past variability of the South Asian Monsoon is mostly known from records of wind strength over the Arabian Sea while high-resolution paleorecords from regions of strong monsoon precipitation are still lacking. Here, we present records of past monsoon variability obtained from sediment core SK 168/GC-1, which was collected at the Alcock Seamount complex in the Andaman Sea. We utilize the ecological habitats of different planktic foraminiferal species to reconstruct freshwater-induced stratification based on paired Mg/Ca and δ18O analyses and to estimate seawater δ18O (δ18Osw). The difference between surface and thermocline temperatures (ΔT) and δ18Osw (Δδ18Osw) is used to investigate changes in upper ocean stratification. Additionally, Ba/Ca in G. sacculifer tests is used as a direct proxy for riverine runoff and sea surface salinity (SSS) changes related to monsoon precipitation on land. Our Δδ18Osw time series reveals that upper ocean salinity stratification did not change significantly throughout the last glacial suggesting little influence of NH insolation changes. The strongest increase in temperature gradients between the mixed layer and the thermocline is recorded for the mid-Holocene and indicate the presence of a significantly shallower thermocline. In line with previous work, the δ18Osw and Ba/Ca records demonstrate that monsoon climate during the LGM was characterized by a significantly weaker southwest monsoon circulation and strongly reduced runoff. Based on our data the South Asian Summer Monsoon (SAM) over the Irrawaddyy strengthened gradually after the LGM beginning at ˜18 ka. This is some 3 kyrs before an increase of the Ba/Ca record from the Arabian Sea and indicates that South Asian Monsoon climate dynamics are more complex than the simple N-S displacement of the ITCZ as generally described for other regions. Minimum δ18Osw values recorded during the mid-Holocene are in phase with Ba/Ca marking a stronger monsoon precipitation

  20. Northern Component Water Variability Over the Past 21 kyr: High-resolution Records From Eirik and Gardar Drifts

    NASA Astrophysics Data System (ADS)

    Elmore, A. C.; Wright, J. D.; Neitzke, L. C.; Henderson, S.

    2007-12-01

    Northern Component Water (NCW; analogous to modern NADW) circulation has been described as bi-modal with shallow flow associated with the last glacial maximum (LGM) and a deeper current associated with the Holocene. We have generated foraminiferal stable isotope records as well as grain size records from cores collected on the Eirik and southern Gardar Drifts. Our records show that the shallow mode of NCW circulation persisted through the deglacial and into the early Holocene. Beginning around 9 ka (calendar age), the core of NCW began to descend, reaching its present position by 8 ka. This is consistent with Fagel et al. (2002) who argued that Denmark Strait overflow, which is the densest contributor to NCW, began around 8.5 ka. We note also that benthic foraminiferal oxygen isotope data from Gardar diverged from the Eirik data during the late deglacial and early Holocene, and may indicate the resumption of flow over the Iceland-Faroe Ridge and/or through the Faroe Bank Channel. Higher frequency changes in the benthic foraminiferal carbon isotopes during the late glacial through deglacial record interruptions in NCW flow. A 1 per mil decrease occurred from 18 to 16 ka. This decrease was associated with a 4-fold decrease in sedimentation rates and is interpreted as a further shoaling of NCW and influx of AABW. The start of this decrease predates the H1 event but the carbon isotope decrease continued through the H1 event, reaching minimum values at 16.3 ka. Between 16.3 and 14.0 ka, carbon isotope values fluctuated between 0 and 0.75 per mil. Sedimentation rates increased sharply to rates >25 cm/kyr, indicating that the current was actively supplying sediments with minimal winnowing. At 14 ka, carbon isotope values increased to ~1 per mil, associated with the Bolling-Allerod warming, and fluctuated about a mean of 1 per mil until the beginning of the Younger Dryas at 12.5ka. During the Younger Dryas, benthic carbon isotope values decreased by 0.5 per mil, signaling

  1. A Compact X-Ray Source in the Radio Pulsar-wind Nebula G141.2+5.0

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.; Borkowski, Kazimierz J.

    2016-01-01

    We report the results of a 50 ks Chandra observation of the recently discovered radio object G141.2+5.0, presumed to be a pulsar-wind nebula. We find a moderately bright unresolved X-ray source that we designate CXOU J033712.8 615302 coincident with the central peak radio emission. An absorbed power-law fit to the 241 counts describes the data well, with absorbing column {N}H=6.7(4.0,9.7)× {10}21 cm-2 and photon index {{Γ }}=1.8(1.4,2.2). For a distance of 4 kpc, the unabsorbed luminosity between 0.5 and 8 keV is {1.7}-0.3+0.4× {10}32 erg s-1 (90% confidence intervals). Both LX and Γ are quite typical of pulsars in PWNe. No extended emission is seen; we estimate a conservative 3σ upper limit to the surface brightness of any X-ray PWN near the point source to be 3× {10}-17 erg cm-2 s-1 arcsec-2 between 0.5 and 8 keV, assuming the same spectrum as the point source; for a nebula of diameter 13\\prime\\prime , the flux limit is 6% of the flux of the point source. The steep radio spectrum of the PWN (α ˜ -0.7), if continued to the X-ray without a break, predicts {L}{{X}} {{(nebula)}}˜ 1× {10}33 erg s-1, so additional spectral steepening between radio and X-rays is required, as is true of all known PWNe. The high Galactic latitude gives a z-distance of 350 pc above the Galactic plane, quite unusual for a Population I object.

  2. NuSTAR Study of Hard X-Ray Morphology and Spectroscopy of PWN G21.5-0.9

    NASA Astrophysics Data System (ADS)

    Nynka, Melania; Hailey, Charles J.; Reynolds, Stephen P.; An, Hongjun; Baganoff, Frederick K.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Gotthelf, Eric V.; Grefenstette, Brian W.; Harrison, Fiona A.; Krivonos, Roman; Madsen, Kristin K.; Mori, Kaya; Perez, Kerstin; Stern, Daniel; Wik, Daniel R.; Zhang, William W.; Zoglauer, Andreas

    2014-07-01

    We present NuSTAR high-energy X-ray observations of the pulsar wind nebula (PWN)/supernova remnant G21.5-0.9. We detect integrated emission from the nebula up to ~40 keV, and resolve individual spatial features over a broad X-ray band for the first time. The morphology seen by NuSTAR agrees well with that seen by XMM-Newton and Chandra below 10 keV. At high energies, NuSTAR clearly detects non-thermal emission up to ~20 keV that extends along the eastern and northern rim of the supernova shell. The broadband images clearly demonstrate that X-ray emission from the North Spur and Eastern Limb results predominantly from non-thermal processes. We detect a break in the spatially integrated X-ray spectrum at ~9 keV that cannot be reproduced by current spectral energy distribution models, implying either a more complex electron injection spectrum or an additional process such as diffusion compared to what has been considered in previous work. We use spatially resolved maps to derive an energy-dependent cooling length scale, L(E)vpropEm with m = -0.21 ± 0.01. We find this to be inconsistent with the model for the morphological evolution with energy described by Kennel & Coroniti. This value, along with the observed steepening in power-law index between radio and X-ray, can be quantitatively explained as an energy-loss spectral break in the simple scaling model of Reynolds, assuming particle advection dominates over diffusion. This interpretation requires a substantial departure from spherical magnetohydrodynamic, magnetic-flux-conserving outflow, most plausibly in the form of turbulent magnetic-field amplification.

  3. Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2

    NASA Astrophysics Data System (ADS)

    Gantt, B.; Kelly, J. T.; Bash, J. O.

    2015-11-01

    Sea spray aerosols (SSAs) impact the particle mass concentration and gas-particle partitioning in coastal environments, with implications for human and ecosystem health. Model evaluations of SSA emissions have mainly focused on the global scale, but regional-scale evaluations are also important due to the localized impact of SSAs on atmospheric chemistry near the coast. In this study, SSA emissions in the Community Multiscale Air Quality (CMAQ) model were updated to enhance the fine-mode size distribution, include sea surface temperature (SST) dependency, and reduce surf-enhanced emissions. Predictions from the updated CMAQ model and those of the previous release version, CMAQv5.0.2, were evaluated using several coastal and national observational data sets in the continental US. The updated emissions generally reduced model underestimates of sodium, chloride, and nitrate surface concentrations for coastal sites in the Bay Regional Atmospheric Chemistry Experiment (BRACE) near Tampa, Florida. Including SST dependency to the SSA emission parameterization led to increased sodium concentrations in the southeastern US and decreased concentrations along parts of the Pacific coast and northeastern US. The influence of sodium on the gas-particle partitioning of nitrate resulted in higher nitrate particle concentrations in many coastal urban areas due to increased condensation of nitric acid in the updated simulations, potentially affecting the predicted nitrogen deposition in sensitive ecosystems. Application of the updated SSA emissions to the California Research at the Nexus of Air Quality and Climate Change (CalNex) study period resulted in a modest improvement in the predicted surface concentration of sodium and nitrate at several central and southern California coastal sites. This update of SSA emissions enabled a more realistic simulation of the atmospheric chemistry in coastal environments where marine air mixes with urban pollution.

  4. Precision alignment of the Advanced Light Source U5.0 and U8.0 undulators

    SciTech Connect

    Humphries, D.; Chin, J.; Connors, R.; Cummings, J.; Keffler, T.; Gath, W.; Hoyer, E.; Kincaid, B.M.; Pipersky, P.

    1993-07-01

    The U5.0 and U8.0 undulators for the Advanced Light Source (ALS) incorporate 4.6-m-long, hybrid-configuration magnetic structures. The structures consist of modules with half-period pole assemblies mounted on 0.8-m-long aluminum mounts, which are in turn attached to continuous steel backing beams. The vertical and longitudinal alignment tolerances for the poles of these structures are 25 microns and 50 microns, respectively, over the entire 4.6-m length of the devices. To meet these tolerances, the modules were first aligned individually using an automated coordinate measurement machine and shimming techniques. Several adjustment iterations were required for each module. Averaging and three-dimensional linear least-squares fitting techniques were employed to establish statistically based error reference planes. Graphical spread sheets were used to create representations of vertical and longitudinal pole position errors for alignment. The adjusted modules were installed on the backing beams and aligned relative to each other using laser interferometer techniques. The longitudinal positions of all poles of each module were measured using a simple linear interferometer and associated optics. Because of the differential expansion coefficient between the aluminum modules and steel backing beam, a bilinear temperature-compensation function was applied to the position data to predict periodicity errors at a predetermined operating temperature, which is generally higher than temperatures in assembly and measurement areas. Vertical alignment of the periodic modules was performed by generating vertical pole position error profiles of the full 4.6-m structures. Least-squares-fit planes for each module were calculated and used in making differential vertical and angular adjustments. Repeatability error for these measurements was typically less than 3 microns. In addition, by using difference techniques, systematic profile variations of 1 micron have been resolved.

  5. NuSTAR Study of Hard X-ray Morphology and Spectroscopy G21.5-0.9

    NASA Technical Reports Server (NTRS)

    Nynka, Melania; Hailey, Charles J.; Reynolds, Stephen P.; An, Hongjun; Baganoff, Frederick K.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Gotthelf, Eric V.; Grefenstette, Brian W.; Harrison, Fiona A.; Krivonos, Roman; Madsen, Kristin K.; Mori, Kaya; Perez, Kerstin; Stern, Daniel; Wik, Daniel R.; Zhang, William W.; Zoglauer, Andreas

    2014-01-01

    We present NuSTAR high-energy X-ray observations of the pulsar wind nebula (PWN)/supernova remnant G21.5-0.9. We detect integrated emission from the nebula up to approx. 40 keV, and resolve individual spatial features over a broad X-ray band for the first time. The morphology seen by NuSTAR agrees well with that seen by XMM-Newton and Chandra below 10 keV. At high energies, NuSTAR clearly detects non-thermal emission up to approx. 20 keV that extends along the eastern and northern rim of the supernova shell. The broadband images clearly demonstrate that X-ray emission from the North Spur and Eastern Limb results predominantly from non-thermal processes. We detect a break in the spatially integrated X-ray spectrum at approx. 9 keV that cannot be reproduced by current spectral energy distribution models, implying either a more complex electron injection spectrum or an additional process such as diffusion compared to what has been considered in previous work. We use spatially resolved maps to derive an energy-dependent cooling length scale, E(sup m) is directly proportional to L(E) with m = -0.21 plus or minus 0.01. We find this to be inconsistent with the model for the morphological evolution with energy described by Kennel & Coroniti. This value, along with the observed steepening in power-law index between radio and X-ray, can be quantitatively explained as an energy-loss spectral break in the simple scaling model of Reynolds, assuming particle advection dominates over diffusion. This interpretation requires a substantial departure from spherical magnetohydrodynamic, magnetic-flux-conserving outflow, most plausibly in the form of turbulent magnetic-field amplification.

  6. Orbital-scale stratigraphy and paleoenvironmental changes in the Japan Sea during the last 230 kyr based on oxygen and carbon isotopes of benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Nakahashi, K.; Kimoto, K.; Tada, R.; Tamaki, K.

    2009-12-01

    Paleoceanographic conditions in the Japan Sea changed drastically during the late Quaternary in association with orbital and suborbital cycles and glacio-eustatic sea level changes. However, few studies had been examined long-term sediment records older than last intergracial period because of the lack of long cores which contains continuous paleoclimatic records and difficulties reconstructing high-resolution age models. Especially disappearance of benthic foraminifers by euxinic bottom water conditions during glacial maxima makes it difficult to understand specific bottom water environments. In this study, we reconstructed benthic foraminiferal stable isotopic stratigraphy of the Japan Sea core with the resolution in 2 kyr. and compared the global stack of benthic foraminfieral δ18O curve (LR04, Lisiecki & Raymo, 2005). The investigated core MD01-2408, was recovered from 806 m water depth, off Akita Prefecture during IMAGES VII cruise. It had recorded continuous paleoenvironmental histories during the last 230 kyr through the core. This core was mainly consisted of alternating layers of homogeneous light colored silty clay and laminated or bioturbated dark colored silty clay, occasionally intercalating volcanic ash layers. The most abundant benthic foraminiferal species are Uvigerina akitaensis, Angulogerina kokozuraensis and Islandiella norcrossi. Abundance of these species fluctuated drastically through the core. No benthic foraminifera is found in two dark layer intervals 4 ~ 5 mbsf and 25 ~ 25.5 mbsf, corresponding 15 ~ 25 kyr and 149 ~ 152 kyr, respectively, probably representing super anoxic bottom water conditions(Oba et al 1984 1991;Tada et al., 1999). δ18O of U. akitaensis and A. kokozuraensis showed a similar values with a precision of ± 0.27‰ and it was inferred that both species had similar habitat. δ18O of both species in core MD01-2408 fluctuated with the range of 2‰ over 230 kyr. Although benthic δ18O stack of LR04 reached to 5 ‰ during

  7. Evidence for a late Holocene warm and humid climate period and environmental characteristics in the arid zones of northwest China during 2.2 ˜ 1.8 kyr B.P.

    NASA Astrophysics Data System (ADS)

    Bao, Yang; Braeuning, Achim; Yafeng, Shi; Fahu, Chen

    2004-01-01

    Natural archives like ice cores, tree rings, river and lake sediments, lake terraces, and paleosols and also historical documents witness aspects of climate change in northwestern China during the Western and Eastern Han Dynasties (206 B.C.-220 A.D.). Reconstructions of decadal averages of annual mean temperature and precipitation fluctuations were derived from variations of δ18O and net accumulation rates in the Guliya ice core. They revealed a period of higher temperatures and higher precipitation than today, which affected vast areas of northwestern China during the period of interest until the fifth century A.D. These conditions resulted in a marked increase in the discharge of big endorheic river systems, such as the Tarim, the Keriya and the Manas rivers. As a consequence, water levels in appendant terminal lakes rose, e.g., at Lop Nor, Manas Lake, and Baijian Hu. Lake surface areas expanded, and lake desalting occurred also at lakes in intermontane basins, such as Balikun Hu and Qinghai Lake. The warm and moist conditions during the Western and Eastern Han Dynasties might have been responsible for the large-scale agricultural production and the local socioeconomic boom that is documented by the occurrence of the famous ruin groups of Loulan, Niya, and Keriya. The following desiccation phase led to a deterioration of water resources, and most oases tended to dry out and were finally abandoned. The appearance, development, flourishing, and final abandonment of each great ruin group are closely associated with regional climate change at that time.

  8. Evidence for Mid-latitude Lake-level Response to Millennial and Milankovitch Forcing: The Past 65 kyr at Mono Lake, CA

    NASA Astrophysics Data System (ADS)

    Zimmerman, S. H.; Hemming, S. R.; Hemming, N. G.; Pearl, C.; Hartin, C.

    2007-12-01

    Mono Lake, California (38°N, 119°W) lies in the western Great Basin in the rain shadow of the Sierra Nevada, and preserves high-elevation strandlines indicating that lake level was much higher in the past. Comparison of stratigraphy-based relative lake level with geochemical records from three sites around the lake (overlapping between 40-32 ka), reveals high carbonate fluxes at times of high lake level on precessional (20-kyr) time-scales. Although absolute values are different in different locations representing slightly different paleoenvironmental settings, the timing and relative amplitude of changes are similar on orbital as well as millennial time-scales. Within the established regional 100-kyr pattern of wet glacials-dry interglacials, we find that during the last glaciation (Marine Isotope Stages (MIS) 4-3-2) times of high spring insolation were generally wetter, represented by lacustrine silts rather than sand facies and greater carbonate flux to the deep-lake sediments. This interval is also characterized by high-amplitude variability. Age model errors of ~1 kyr or less during MIS 3 allow correlation of sharp increases in carbonate deposition with Dansgaard-Oeschger warmings in Greenland. If the high carbonate-high lake relationship holds at millennial time-scales, this would indicate increases in lake level coeval with warming, opposite to the 100-kyr regional pattern. Alternatively, carbonate precipitation may be triggered by lake level peaking and beginning to drop, suggesting that lake level began to fall about the time of Greenland warming. Regardless, the correspondence in phasing between Mono Lake and Greenland, also demonstrated in the nearby Santa Barbara Basin, suggests that Mono Lake responded rapidly to the atmosphere-ocean changes invoked to explain the global nature of the D-O events. The suppression of this variability during times of low spring insolation may be due to a reduced sensitivity of the recorder, and we are looking for

  9. Holocene sedimentary evolution of a mid-ocean atoll lagoon, Maldives, Indian Ocean

    NASA Astrophysics Data System (ADS)

    Klostermann, Lars; Gischler, Eberhard

    2015-01-01

    Based on detailed analyses of cores covering the lagoon of Rasdhoo Atoll, Maldives, six carbonate facies, one soil, and one peat facies have been identified. The abundance of carbonate and rare opaque grains was quantified with a point counter. X-ray diffractometry was used to measure mineralogical composition of samples. The statistical delineation of facies using cluster analysis was based on point count, mineralogical, and textural analyses. In decreasing abundance, the six carbonate facies are classified as mollusk-coral-algal floatstone to rudstone (30 %), mollusk-coral-red algae rudstone (23 %), mollusk-coral-algal wackestone to floatstone (23 %), mollusk-coral wackestone (13 %), mollusk-coral mudstone to wackestone (9 %), and mollusk mudstone (2 %). The carbonate facies represent lagoonal background sedimentation, mostly consisting of fine sediments, and event sedimentation depositing transported coarse-grained reefal components. Fifty-seven carbonate samples and one peat sample were dated radiometrically, covering the Holocene transgression from 10 kyrs BP until today. Comparing the sediment accumulation data of the lagoon with two local sea-level curves, three systems tracts can be identified: (1) a lowstand systems tract characterized by karst and soil deposition >10 kyrs BP, (2) a transgressive systems tract with peat and carbonate separated by hiatus 10-6.5 kyrs BP, and (3) a highstand systems tract dominated by carbonate sedimentation 6.5-0 kyrs BP and further divided into three stages (6.5-3, 3-1, and 1-0 kyrs BP). During the Holocene transgression, sedimentation rates increased continuously to a maximum of 1.4 m/kyr during 3-1 kyrs BP. Modern (1-0 kyrs BP) mean sedimentation rates average 0.6 m/kyr. A simple calculation suggests that two processes (background sedimentation and sand apron progradation) will probably fill up the accommodation space of the lagoon during the Holocene highstand, but these processes will not suffice to fill the larger

  10. H II Region G46.5-0.2: The Interplay between Ionizing Radiation, Molecular Gas, and Star Formation

    NASA Astrophysics Data System (ADS)

    Paron, S.; Ortega, M. E.; Dubner, G.; Yuan, Jing-Hua; Petriella, A.; Giacani, E.; Li, Jin Zeng; Wu, Yuefang; Liu, Hongli; Huang, Ya Fang; Zhang, Si-Ju

    2015-06-01

    H ii regions are particularly interesting because they can generate dense layers of gas and dust, elongated columns or pillars of gas pointing toward the ionizing sources, and cometary globules of dense gas where triggered star formation can occur. Understanding the interplay between the ionizing radiation and the dense surrounding gas is very important to explain the origin of these peculiar structures, and hence to characterize triggered star formation. G46.5-0.2 (G46), a poorly studied galactic H ii region located at about 4 kpc, is an excellent target for performing this kind of study. Using public molecular data extracted from the Galactic Ring Survey (13CO J = 1-0) and from the James Clerk Maxwell Telescope data archive (12CO, 13CO, C18O J = 3-2, HCO+, and HCN J = 4-3), and infrared data from the GLIMPSE and MIPSGAL surveys, we perform a complete study of G46, its molecular environment, and the young stellar objects (YSOs) placed around it. We found that G46, probably excited by an O7V star, is located close to the edge of the GRSMC G046.34-00.21 molecular cloud. It presents a horse-shoe morphology opening in the direction of the cloud. We observed a filamentary structure in the molecular gas likely related to G46 and not considerable molecular emission toward its open border. We found that about 10‧ to the southwest of G46 there are some pillar-like features, shining at 8 μm and pointing toward the H ii region open border. We propose that the pillar-like features were carved and sculpted by the ionizing flux from G46. We found several YSOs likely embedded in the molecular cloud grouped in two main concentrations: one, closer to the G46 open border consisting of Class II type sources, and another mostly composed of Class I type YSOs located just ahead of the pillar-like features, strongly suggesting an age gradient in the YSO distribution.

  11. A 300 kyr Record of Geomagnetic Excursions and Paleointensity From the Irminger Basin: Candidates for Mono Lake, Laschamp, Iceland Basin, Jamaica and Pringle Falls?

    NASA Astrophysics Data System (ADS)

    Channell, J. E.

    2004-12-01

    Sediments recovered at ODP Site 919, off east Greenland, record geomagnetic directional excursions at 33 ka and 40 ka (Mono Lake and Laschamp), and at 187 ka (Iceland Basin), 208 ka (Jamaica?) and at 220 ka (Pringle Falls). U-channel records are augmented by 1-cm discrete samples collected back-to-back alongside the u-channel troughs. Deconvolution of the u-channel records yields records that can be closely matched to the discrete sample data. The age-model based on planktic oxygen isotope data (St. John et al., Marine Geology, in press) is consistent with the relative paleointensity record and the recognition of Ash Layer 2 (55 ka). The results indicate that the Mono Lake and Laschamp excursions, and the Iceland Basin and Pringle Falls (and perhaps also Jamaica), are distinct excursions, rarely recorded together in individual stratigraphic sections. Why are they recorded at ODP Site 919? Mean sedimentation rates are 22 cm/kyr in MIS 3 where Mono Lake/Laschamp are recorded, but sedimentation rates do not appear to be especially high in MIS 7 (13 cm/kyr) where candidates for Iceland Basin/Jamaica/Pringle Falls are recorded.

  12. An 80 kyr-long continuous speleothem record from Dim Cave, SW Turkey with paleoclimatic implications for the Eastern Mediterranean.

    PubMed

    Ünal-İmer, Ezgi; Shulmeister, James; Zhao, Jian-Xin; Uysal, I Tonguç; Feng, Yue-Xing; Nguyen, Ai Duc; Yüce, Galip

    2015-01-01

    Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ(18)O) and carbon (δ(13)C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ(18)O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ(13)C are interpreted as reflecting soil organic matter composition and/or thickness. δ(13)C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM. PMID:26337921

  13. Bulk and Compound-Specific Isotope Analysis of Long-Chain, n-alkanes From a 85-kyr Core From Lake Peten Itza, Guatemala

    NASA Astrophysics Data System (ADS)

    Mays, J. L.; Brenner, M.; Bush, M. B.; Correa, A.; Curtis, J. H.; Hodell, D. A.

    2007-12-01

    Drill cores obtained from Lake Petén Itzá, Guatemala, contain a ~85-kyr record of terrestrial climate from lowland Central America. Variations in sediment lithology suggest rapid changes in precipitation during the last glacial and deglacial periods. Previous work in nearby Lake Quexil demonstrated the utility of using the carbon isotopic compositions of leaf wax n-alkanes to infer changes in terrestrial vegetation (Huang et al., 2001). Here we report carbon isotopes of bulk organic and long-chain n-alkanes in 60 samples to reconstruct changes in the relative proportion of C3 and C4 biomass in the watershed under changing climate and atmospheric CO2 conditions during the past 85 kyrs. Compound-specific carbon isotope results are compared directly with pollen analysis from the same samples. Huang, Y., F.A. Street-Perrott, S.E. Metcalfe, M. Brenner, M. Moreland, and K.H. Freeman. 2001. Climate change as the dominant control on glacial-interglacial variations in C3 and C4 plant abundance. Science 293:1647-1651.

  14. Man the Fat Hunter: The Demise of Homo erectus and the Emergence of a New Hominin Lineage in the Middle Pleistocene (ca. 400 kyr) Levant

    PubMed Central

    Ben-Dor, Miki; Gopher, Avi; Hershkovitz, Israel; Barkai, Ran

    2011-01-01

    The worldwide association of H. erectus with elephants is well documented and so is the preference of humans for fat as a source of energy. We show that rather than a matter of preference, H. erectus in the Levant was dependent on both elephants and fat for his survival. The disappearance of elephants from the Levant some 400 kyr ago coincides with the appearance of a new and innovative local cultural complex – the Levantine Acheulo-Yabrudian and, as is evident from teeth recently found in the Acheulo-Yabrudian 400-200 kyr site of Qesem Cave, the replacement of H. erectus by a new hominin. We employ a bio-energetic model to present a hypothesis that the disappearance of the elephants, which created a need to hunt an increased number of smaller and faster animals while maintaining an adequate fat content in the diet, was the evolutionary drive behind the emergence of the lighter, more agile, and cognitively capable hominins. Qesem Cave thus provides a rare opportunity to study the mechanisms that underlie the emergence of our post-erectus ancestors, the fat hunters. PMID:22174868

  15. An 80 kyr-long continuous speleothem record from Dim Cave, SW Turkey with paleoclimatic implications for the Eastern Mediterranean

    PubMed Central

    Ünal-İmer, Ezgi; Shulmeister, James; Zhao, Jian-Xin; Tonguç Uysal, I.; Feng, Yue-Xing; Duc Nguyen, Ai; Yüce, Galip

    2015-01-01

    Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ18O) and carbon (δ13C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ18O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ13C are interpreted as reflecting soil organic matter composition and/or thickness. δ13C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM. PMID:26337921

  16. Centennial- to millennial-scale ice-ocean interactions in the subpolar northeast Atlantic 18-41 kyr ago

    NASA Astrophysics Data System (ADS)

    Hall, I. R.; Colmenero-Hidalgo, E.; Zahn, R.; Peck, V. L.; Hemming, S. R.

    2011-06-01

    In order to monitor the evolution of the British-Irish Ice Sheet (BIIS) and its influence in surface ocean structure during marine isotopic stages (MIS) 2 and 3, we have analyzed the sediments recovered in core MD04-2829CQ (Rosemary Bank, north Rockall Trough, northeast Atlantic) dated between ˜41 and ˜18 ka B.P. Ice-rafted debris flux and composition, 40Ar/39Ar ages of individual hornblende grains, multispecies planktonic stable isotope records, planktonic foraminifera assemblage data and faunal-based sea surface temperatures (SSTs) demonstrate a close interaction between BIIS dynamics and surface ocean structure and water properties in this region. The core location lies beneath the North Atlantic Current (NAC) and is ideal for monitoring the shifts in the position of its associated oceanic fronts, as recorded by faunal changes. These data reveal a succession of BIIS-sourced iceberg calving events related to low SST, usually synchronous with dramatic changes in the composition of the planktonic foraminifera assemblage and with variations in the stable isotope records of the taxa Neogloboquadrina pachyderma (sinistral coiling) and Globigerina bulloides. The pacing of the calving events, from typically Dansgaard-Oeschger millennial timescales during late MIS 3 to multicentennial cyclicity from ˜28 ka B.P., represents the build-up of the BIIS and its growing instability toward Heinrich Event (HE) 2 and the Last Glacial Maximum. Our data confirm the strong coupling between BIIS instabilities and the temperature and salinity of surface waters in the adjacent northeast Atlantic and demonstrate the BIIS's ability to modify the NAC on its flow toward the Nordic Seas. In contrast, subsurface water masses were less affected except during the Greenland stadials that contain HEs, when most intense water column reorganizations occurred simultaneously with the deposition of cream-colored carbonate sourced from the Laurentide Ice Sheet.

  17. Biogeochemistry of mineral-organic associations across a long-term mineralogical soil gradient (0.3-4100 kyr), Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Mikutta, Robert; Schaumann, Gabriele E.; Gildemeister, Daniela; Bonneville, Steeve; Kramer, Marc G.; Chorover, Jon; Chadwick, Oliver A.; Guggenberger, Georg

    2009-04-01

    Organic matter (OM) in mineral-organic associations (MOAs) represents a large fraction of carbon in terrestrial ecosystems which is considered stable against biodegradation. To assess the role of MOAs in carbon cycling, there is a need to better understand (i) the time-dependent biogeochemical evolution of MOAs in soil, (ii) the effect of the mineral composition on the physico-chemical properties of attached OM, and (iii) the resulting consequences for the stabilization of OM. We studied the development of MOAs across a mineralogical soil gradient (0.3-4100 kyr) at the Hawaiian Islands that derived from basaltic tephra under comparable climatic and hydrological regimes. Mineral-organic associations were characterized using biomarker analyses of OM with chemolytic methods (lignin phenols, non-cellulosic carbohydrates) and wet chemical extractions, surface area/porosity measurements (N 2 at 77 K and CO 2 at 273 K), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results show that in the initial weathering stage (0.3 kyr), MOAs are mainly composed of primary, low-surface area minerals (olivine, pyroxene, feldspar) with small amounts of attached OM and lignin phenols but a large contribution of microbial-derived carbohydrates. As high-surface area, poorly crystalline (PC) minerals increase in abundance during the second weathering stage (20-400 kyr), the content of mineral-associated OM increased sharply, up to 290 mg C/g MOA, with lignin phenols being favored over carbohydrates in the association with minerals. In the third and final weathering stage (1400-4100 kyr), metastable PC phases transformed into well crystalline secondary Fe and Al (hydr)oxides and kaolin minerals that were associated with less OM overall, and depleted in both lignin and carbohydrate as a fraction of total OM. XPS, the N 2 pore volume data and OM-mineral volumetric ratios suggest that, in contrast to the

  18. The determination of potential energy curve and dipole moment of the (5)0(+) electronic state of (85)Rb(133)Cs molecule by high resolution photoassociation spectroscopy.

    PubMed

    Yuan, Jinpeng; Zhao, Yanting; Ji, Zhonghua; Li, Zhonghao; Kim, Jin-Tae; Xiao, Liantuan; Jia, Suotang

    2015-12-14

    We present the formation of ultracold (85)Rb(133)Cs molecules in the (5)0(+) electronic state by photoassociation and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 vibrational and lowest J = 0 levels are identified with rotationally resolved high resolution photoassociation spectra. Precise Dunham coefficients are determined for the (5)0(+) state with high accuracy, then the Rydberg-Klein-Rees potential energy curve is derived. The electric dipole moments with respect to the vibrational numbers of the (5)0(+) electronic state of (85)Rb(133)Cs molecule are also measured in the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5)0(+) state are helpful to understand the molecular structure and discover suitable transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state. PMID:26671380

  19. The determination of potential energy curve and dipole moment of the (5)0+ electronic state of 85Rb133Cs molecule by high resolution photoassociation spectroscopy

    NASA Astrophysics Data System (ADS)

    Yuan, Jinpeng; Zhao, Yanting; Ji, Zhonghua; Li, Zhonghao; Kim, Jin-Tae; Xiao, Liantuan; Jia, Suotang

    2015-12-01

    We present the formation of ultracold 85Rb133Cs molecules in the (5)0+ electronic state by photoassociation and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 vibrational and lowest J = 0 levels are identified with rotationally resolved high resolution photoassociation spectra. Precise Dunham coefficients are determined for the (5)0+ state with high accuracy, then the Rydberg-Klein-Rees potential energy curve is derived. The electric dipole moments with respect to the vibrational numbers of the (5)0+ electronic state of 85Rb133Cs molecule are also measured in the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5)0+ state are helpful to understand the molecular structure and discover suitable transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state.

  20. Statistical Safety Evaluation of BWR Turbine Trip Scenario Using Coupled Neutron Kinetics and Thermal Hydraulics Analysis Code SKETCH-INS/TRACE5.0

    NASA Astrophysics Data System (ADS)

    Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

    The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal- hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method.

  1. Trailer siting issues: BP Texas City.

    PubMed

    Kaszniak, Mark; Holmstrom, Donald

    2008-11-15

    On 23 March, 2005, a series of explosions and fires occurred at the BP Texas City refinery during the startup of an isomerization (ISOM) process unit. Fifteen workers were killed and about 180 others were injured. All of the fatalities were contract workers; the deaths and most of the serious injuries occurred in and around temporary office trailers that had been sited near a blowdown drum and stack open to the atmosphere as part of ongoing turnaround activities in an adjacent unit. Due to problems that developed during the ISOM startup, flammable hydrocarbon liquid overfilled the blowdown drum and stack which resulted in a geyser-like release out the top into the atmosphere. The flammable hydrocarbons fell to the ground releasing vapors that were likely ignited from a nearby idling diesel pickup truck. A total of 44 trailers were damaged by the blast pressure wave that propagated through the refinery when the vapor cloud exploded. Thirteen trailers were totally destroyed and workers were injured in trailers as far as 479ft away from the release. The focus of this paper will be on trailer siting issues, including: need for work/office trailers within process units, adequacy of risk analysis methods in API RP 752, and minimum safe distance requirements PMID:18294765

  2. Transcriptional Regulation of CRD-BP by c-myc

    PubMed Central

    Noubissi, Felicite K.; Nikiforov, Mikhail A.; Colburn, Nancy; Spiegelman, Vladimir S.

    2010-01-01

    The coding region determinant binding protein, CRD-BP, is a multifunctional RNA binding protein involved in different processes such as mRNA turnover, translation control, and localization. It is mostly expressed in fetal and neonatal tissues, where it regulates many transcripts essential for normal embryonic development. CRD-BP is scarce or absent in normal adult tissues but reactivated and/or overexpressed in various neoplastic and preneoplastic tumors and in most cell lines. Its expression has been associated with the most aggressive form of some cancers. CRD-BP is an important regulator of different genes including a variety of oncogenes or proto-oncogenes (c-myc, β-TrCP1, GLI1, etc.). Regulation of CRD-BP expression is critical for proper control of its targets as its overexpression may play an important role in abnormal cell proliferation, suppression of apoptosis, invasion, and metastasis. Molecular bases of the regulatory mechanisms governing CRD-BP expression are still not completely elucidated. In this article, we have identified c-myc as a novel transcriptional regulator of CRD-BP. We show that c-myc binds to CRD-BP promoter and induces its transcription. This induction of CRD-BP expression contributes to the role of c-myc in the regulation of translation, increase in cell size, and acceleration of cell cycle progression via a mechanism involving upregulation of β-TrCP1 levels and activities and accelerated degradation of PDCD4. PMID:21779431

  3. Yarn Quality Prediction Based on Improved BP Neural Network

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Guo; Xiong, Jing-Wei; Xun, Lan

    Aiming at the key quality indexes xbt in spinning processing is caused by many complex and interactions factors. A xbt prediction model is put forward based on the PSO-BP neural network, which adjusts weights of BP neural network using particle swarm optimization (PSO) rather than the traditional gradient descent method, is used to improve the convergence speed of neural network and the ability of getting the global optimal solution. As the object of a large number of field detection data in a spinning workshop, the results show that, compared with the traditional BP algorithm and GA-BP algorithm, the PSO-BP neural network can obvious improve yarn quality prediction model precision and stability.

  4. The determination of potential energy curve and dipole moment of the (5) 0+ electronic state of 85 Rb133 Cs molecule by high resolution photoassociation spectroscopy

    NASA Astrophysics Data System (ADS)

    Yuan, Jinpeng; Zhao, Yanting; Ji, Zhonghua; Li, Zhonghao; Kim, Jin-Tae; Xiao, Liantuan; Jia, Suotang

    2016-05-01

    The creation and manipulation of ultracold polar molecules have attracted intensive attentions due to their permanent electric dipole moments interacting strongly with an external electric field and with long-range dipole-dipole force, which facilitate applications such as precision measurement, quantum control of cold chemical reactions, and quantum computation. The (5) 0+ state is a good candidate to produce ultracold ground state RbCs molecule through a short-range photoassociation (PA). We present the formation of ultracold 85 Rb133 Cs molecules in the (5) 0+ electronic state by PA and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 and lowest J = 0 levels are identified with high resolution. Precise Dunham coefficients and the Rydberg-Klein-Rees potential energy curve of the (5) 0+ state are determined The electric dipole moments with respect to the vibrational numbers of the (5) 0+ electronic state are also measured in the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5) 0+ state are helpful to understand the molecular structure and discover suitable transition pathways for transferring to the lowest rovibrational level of the ground state.

  5. Terrestrial environmental changes around the Gulf of Aden over the last 210 kyr deduced from the sediment n-alkane record: Implications for the dispersal of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Isaji, Yuta; Kawahata, Hodaka; Ohkouchi, Naohiko; Murayama, Masafumi; Tamaki, Kensaku

    2015-03-01

    We analyzed long-chain (C25-C36) n-alkanes and pollen grains in sediments from the Gulf of Aden covering the last 212 kyr to reconstruct the surrounding terrestrial environment, a critical region for the dispersal of Homo sapiens. Substantial increases in the flux of n-alkanes during 200-185, 120-95, and 70-50 ka were interpreted to indicate enhanced vegetation biomass in the Arabian Peninsula and the northern part of the Horn of Africa or increase in lithogenic material inputs. Periods of enhanced n-alkane flux occurred during or immediately after pluvial episodes, indicating that the increased precipitation may have induced substantially enhanced vegetation biomass, creating favorable conditions for Homo sapiens. Additionally, vegetation may have increased due to moderate precipitation unrecorded by speleothems or in accordance with the lowering of sea level, indicating that the dispersal might have been possible even after the shift to an arid environment indicated by the speleothems.

  6. Anti-BP180-type mucous membrane pemphigoid immunoglobulin G shows heterogeneity of internalization of BP180/collagen XVII into keratinocyte cytoplasm.

    PubMed

    Imanishi, Akiko; Imanishi, Hisayoshi; Hiroyasu, Sho; Ozawa, Toshiyuki; Koga, Hiroshi; Ishii, Norito; Kitajima, Yasuo; Hashimoto, Takashi; Tsuruta, Daisuke

    2016-06-01

    Anti-BP180-type mucous membrane pemphigoid (BP180-MMP) is a rare autoimmune subepidermal blistering disease that targets the C terminus of BP180/collagen XVII. Currently, the pathomechanism of BP180-MMP is not well understood. We reported previously that immunoglobulin G (IgG) from patients with bullous pemphigoid (BP) can induce internalization of BP180 via a macropinocytic pathway, which depletes BP180 and weakens epidermal cell-matrix integrity. The purpose of the present study was to elucidate the pathomechanism of BP180-MMP. Immunohistochemistry of biopsy specimens from two patients with BP180-MMP revealed that one patient had BP180 internalization, but the other did not. In live-cell imaging using IgG from patients with BP180-MMP on several keratinocyte cell lines, IgG from only three out of the seven patients was associated with BP180 internalization into the cytoplasm. Our results suggest that IgG from patients with BP180-MMP shows heterogeneity of internalization of BP180. This variability in BP180 internalization in patients with BP or BP180-MMP may lead to differences in clinical presentation. PMID:26658728

  7. Successful Use of Surgically Placed Impella 5.0 and Central Extracorporeal Membrane Oxygenation Circuit in a Patient with Postcardiotomy Shock

    PubMed Central

    Mason, Phillip; Jabbari, Odeaa Al; Samir, Hany; Bruckner, Brian A.

    2015-01-01

    The Impella 5.0, a percutaneously inserted left ventricular assist device, has been used to support patients who have severe heart failure or who are undergoing high-risk percutaneous coronary intervention. We report our surgical placement of the Impella 5.0, through a graft sewn to the aorta, to unload the left ventricle of a 59-year-old man who was undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy shock. The patient underwent successful placement of a long-term left ventricular assist device before his discharge from the hospital. The versatility of the Impella 5.0 is exemplified in this patient who was successfully bridged to long-term support. PMID:26664314

  8. Development of coccolithophore-based transfer functions in the western Mediterranean sea: a sea surface salinity reconstruction for the last 15.5 kyr

    NASA Astrophysics Data System (ADS)

    Ausín, B.; Hernández-Almeida, I.; Flores, J.-A.; Sierro, F.-J.; Grosjean, M.; Francés, G.; Alonso, B.

    2015-12-01

    A new data set of 88 marine surface sediment samples and related oceanic environmental variables (temperature, salinity, chlorophyll a, oxygen, etc.) was studied to quantify the relationship between assemblages of coccolithophore species and modern environmental conditions in the western Mediterranean Sea and the Atlantic Ocean, west of the Strait of Gibraltar. Multivariate statistical analyses revealed that coccolithophore species were primarily related to sea surface salinity (SSS), explaining an independent and significant proportion of variance in the coccolithophore data. A quantitative coccolithophore-based transfer function to estimate SSS was developed using the modern analog technique (MAT) and weighted-averaging partial least square regression (WA-PLS). The bootstrapped regression coefficient (R2boot) was 0.85MAT and 0.80WA-PLS, with a root-mean-square error of prediction (RMSEP) of 0.29MAT and 0.30WA-PLS (psu). The resulting transfer function was applied to fossil coccolithophore assemblages in the highly resolved (~ 65 years) sediment core CEUTA10PC08 from the Alboran Sea (western Mediterranean) in order to reconstruct SSS for the last 25 kyr. The reliability of the reconstruction was evaluated by assessing the degree of similarity between fossil and modern coccolithophore assemblages and by a comparison of reconstructions with fossil ordination scores. Analogs were poor for the stadials associated with Heinrich events 2 and 1 and part of the Last Glacial Maximum. Good analogs indicate a more reliable reconstruction of the SSS for the last 15.5 kyr. During this period, several millennial and centennial SSS changes were observed and associated with sea-level oscillations and variations in the Atlantic Water entering the Alboran.

  9. 200 kyrs of sediment deposition in the coastal lowlands of Bol'shoy Lyakhovsky - a record of deglaciation of the New Siberian Islands?

    NASA Astrophysics Data System (ADS)

    Schwamborn, Georg; Schirrmeister, Lutz; Wetterich, Sebastian; Fuchs, Margret; Meyer, Hanno; Siegert, Christine

    2016-04-01

    Bol'shoy Lyakhovsky, the southernmost island of the New Siberian Archipelago, holds the longest record of palaeoenvironmental history in the North Siberian Arctic. It stretches back to ~200 kyr before present. Next to palaeosols and floodplain deposits it includes prominent thermokarst deposits from the Last Interglacial and Yedoma (Ice Complex) sections from the Last Glacial. Yet, it is unknown, whether or not the depositional history of the area is affected by the deglaciation of the northern part of the New Siberian Archipelago. Potentially, it could give insights into the break-up of the proposed MIS 6 ice sheet located on the East Siberian Sea shelf. Polymodal particle size distributions in the sediment record suggest that more than one transport mechanism drove sediment accumulation from more than one source. From a cryo-sedimentological data set we focus on the mineral composition (63-125 μm fraction) to determine the provenance of the deposits and to identify possible changes of transport pathways. Complementary, we use pore ice hydrochemical data to track changes of the weathering solution preserved in permafrost. Presumably, the both complement each other, since the weathering products largely depend on the mineral composition. We conclude that the observed trends in the heavy mineral and pore ice chemical data of the frozen ground record reflect short-distance material transport from weathered bedrock to the depositional area. In this sense no portion of the 200 kyr record seems to be affected by the presumed MIS 6 ice sheet break-up, which at that time happened about 250 km north of the study site.

  10. A 0.5 Msec Glance at the Supernova Remnant G21.5-0.9 with the Chandra X-ray Observatory

    NASA Astrophysics Data System (ADS)

    Matheson, Heather; Safi-Harb, Samar

    2005-08-01

    G21.5-0.9 is one of approximately 15 currently known Galactic filledcentre supernova remnants (plerions), the most well-known being the Crab Nebula. These filled-centre remnants lack a supernova remnant shell and typically have a larger size in radio than in X-ray. Early Chandra observations of G21.5-0.9 showed that the 40. radius plerion surrounded a 2. compact centre, and revealed a faint 150. radius X-ray halo around G21.5-0.9, making its size in X-ray larger than its radio size. The origin of the X-ray halo remains uncertain. It has been suggested that the halo could be partially due to dust scattering since G21.5-0.9 is a bright and heavily absorbed source (Safi-Harb et al. 2001). We will present an analysis of the brightest regions in the halo of G21.5-0.9 and show the results of a search for line emission using 0.5 Msec of data acquired with the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory over the last six years. We will also show the deepest and highest resolution image of G21.5-0.9 to date. This deep image reveals for the first time 1) a limb-brightened morphology in the eastern section of the halo, and 2) a rich structure in the inner (40_-radius) bright plerion including wisps and a double-lobed morphology with an axis of symmetry running in the northwest-southeast direction.

  11. Possible enhancement of BP180 autoantibody production by herpes zoster.

    PubMed

    Kamiya, Koji; Aoyama, Yumi; Suzuki, Takahiro; Niwa, Haruo; Horio, Ai; Nishio, Eiichi; Tokura, Yoshiki

    2016-02-01

    Bullous pemphigoid (BP) is an autoimmune blistering disease caused by autoantibodies against type XVII collagen/BP180 (BP180). Although the mechanisms of autoantibody production remain to be elucidated, herpes virus infections have been identified as a possible triggering factor for pemphigus. We report a case of herpes zoster (HZ) having anti-BP180 serum antibodies. The patient developed sudden-onset, tense blisters and edematous erythema on the right anterior chest, shoulder and upper back. Histopathology showed remarkable degeneration of keratinocytes, acantholysis and blister formation with ballooning cells, indicating herpes virus infection. A polymerase chain reaction analysis of varicella zoster virus (VZV) was positive in crusts and effusions from the skin lesions, confirming the definitive diagnosis of HZ. Notably, we found that the patient had anti-BP180 serum antibodies in association with the occurrence of HZ. After successful treatment with valacyclovir hydrochloride for 7 days, the serum levels of anti-BP180 antibodies decreased in accordance with the improvement of skin lesions. These findings suggest that the production of anti-BP180 antibodies could be triggered by the reactivation of VZV. PMID:26212492

  12. Pelagic-benthic coupling within an upwelling system of the subtropical northeast Atlantic over the last 35 ka BP

    NASA Astrophysics Data System (ADS)

    McKay, C. L.; Filipsson, H. L.; Romero, O. E.; Stuut, J.-B. W.; Donner, B.

    2014-12-01

    We present a high resolution, multiproxy study of the relationship between pelagic and benthic environments of a coastal upwelling system in the subtropical NE Atlantic Ocean. Marine sediments corresponding to late MIS3 to the Holocene in the radiocarbon dated core GeoB7926, retrieved off Mauritania (21°N) were analysed to reconstruct productivity in surface waters and its linkage to deep waters during the last 35 ka BP. High latitude cold events and changes in atmospheric and oceanographic dynamics influenced upwelling intensity over this time period. Subsequently, this caused changes in primary productivity off this low-latitude coastal upwelling locality. The benthic foraminiferal fauna displays four main community shifts corresponding to fundamental climatic events, first of all during late MIS3 (35-28 ka BP), secondly from 28 to 19 ka BP (including Heinrich event 2 and the LGM), thirdly within Heinrich event 1, the Bølling Allerød and the Younger Dryas (18-11.5 ka BP) and finally during the Holocene (11.5-0 ka BP). In particular, strong pelagic-benthic coupling is apparent in MIS 3, as demonstrated by increased primary productivity, indicated by moderate DAR and the dominance of benthic foraminiferal species which prefer fresh phytodetritus. A decline in upwelling intensity and nutrient availability follows, which resulted in a proportionately larger amount of older, degraded matter, provoking a shift in the benthic foraminifera fauna composition. This rapid response of the benthic environment continues with a progressive increase in upwelling intensity due to sea level and oceanographic changes and according high surface production during the LGM. During Heinrich event 1 and the Younger Dryas, extreme levels of primary production actually hindered benthic environment through the development of low oxygen conditions. After this period, a final change in benthic foraminiferal community composition occurs which indicates a return to more oxygenated conditions

  13. Reaching 5.0×10-13 τ -1/2 short term frequency stability of the integrating sphere cold atom clock

    NASA Astrophysics Data System (ADS)

    Liu, P.; Meng, Y. L.; Wan, J. Y.; Wang, X. M.; Wang, Y. N.; Xiao, L.; Cheng, H. D.; Liu, L.

    2016-06-01

    We present an improvement of short term frequency stability of the integrating sphere cold atom clock after increasing the intensities of clock signals and optimizing the feedback loop of the clock. A short term frequency stability of 5.0×10-13 τ -1/2 has been achieved and the limiting factors have been analyzed.

  14. “Dynamic evaluation of the CMAQv5.0 modeling system: Assessing the model’s ability to simulate ozone changes due to NOx emission reductions”

    EPA Science Inventory

    Dynamic evaluation of the CMAQv5.0 modeling system during the NOx SIP Call time period indicates that the model underestimates the observed ozone decrease in eastern U.S. Utilizing novel cross simulations we are able to separately quantify the impact on ozone predictions stemmin...

  15. SAS2H input for computing core activities of 4.5, 5.0, and 5.5 weight % {sup 235}U fuel for Sequoyah Nuclear Plant

    SciTech Connect

    Hermann, O.W.

    1994-08-01

    Sequoyah Nuclear Plant core activities at initial fuel enrichments of 4.5, 5.0, and 5.5 wt% {sup 235}U, required in nuclear safety evaluations, were computed by the SAS2H analysis sequence and the ORIGEN-S code within the SCALE-4.2 code system.

  16. Systems analysis programs for Hands-on integrated reliability evaluations (SAPHIRE) Version 5.0: Verification and validation (V&V) manual. Volume 9

    SciTech Connect

    Jones, J.L.; Calley, M.B.; Capps, E.L.; Zeigler, S.L.; Galyean, W.J.; Novack, S.D.; Smith, C.L.; Wolfram, L.M.

    1995-03-01

    A verification and validation (V&V) process has been performed for the System Analysis Programs for Hands-on Integrated Reliability Evaluation (SAPHIRE) Version 5.0. SAPHIRE is a set of four computer programs that NRC developed for performing probabilistic risk assessments. They allow an analyst to perform many of the functions necessary to create, quantify, and evaluate the risk associated with a facility or process being analyzed. The programs are Integrated Reliability and Risk Analysis System (IRRAS) System Analysis and Risk Assessment (SARA), Models And Results Database (MAR-D), and Fault tree, Event tree, and Piping and instrumentation diagram (FEP) graphical editor. Intent of this program is to perform a V&V of successive versions of SAPHIRE. Previous efforts have been the V&V of SAPHIRE Version 4.0. The SAPHIRE 5.0 V&V plan is based on the SAPHIRE 4.0 V&V plan with revisions to incorporate lessons learned from the previous effort. Also, the SAPHIRE 5.0 vital and nonvital test procedures are based on the test procedures from SAPHIRE 4.0 with revisions to include the new SAPHIRE 5.0 features as well as to incorporate lessons learned from the previous effort. Most results from the testing were acceptable; however, some discrepancies between expected code operation and actual code operation were identified. Modifications made to SAPHIRE are identified.

  17. Methanococcus vannielii selenium-binding protein (SeBP): Chemical reactivity of recombinant SeBP produced in Escherichia coli

    PubMed Central

    Patteson, Kemberly G.; Trivedi, Neel; Stadtman, Thressa C.

    2005-01-01

    A selenium-binding protein (SeBP) from Methanococcus vannielii was recently identified, and its gene was isolated and overexpressed in Escherichia coli [Self, W. T., Pierce, R. & Stadtman, T. C. (2004) IUBMB Life 56, 501–507]. SeBP and recombinant SeBP (rSeBP) migrated as ≈42-kDa species on native gels and as ≈33-kDa species on SDS gels. rSeBP consists of identical 8.8-kDa subunits, each containing a single cysteine residue. rSeBP isolated in the absence of reducing agents contained oxidized cysteine (89%) and very little bound selenium (0.05 eq or less per subunit). Complete reduction of the oxidized cysteine residues in rSeBP with Tris(2-carboxyethyl)phosphine required addition of a denaturant, such as 1 M guanidine-hydrochloride. With selenite as the selenium source and the isolated reduced protein as sole reductant, binding of one selenium per tetramer under anaerobic conditions required four cysteine thiol groups, one on each subunit. In the corresponding reaction, with reduced glutathione (GSH), equimolar amounts of selenodiglutathione (GSSeSG) and glutathione disulfide are formed from selenite and 4 GSH. At GSH-to-selenite ratios >4:1, conversion of GSSeSG to a perselenide derivative, GSSe–, occurs. However, with the reduced rSeBP as sole electron donor in the reaction with selenite, further conversion of the R-SSeS-R product apparently did not occur. Prior alkylation of the cysteine thiol groups in reduced rSeBP prevented selenite reduction and selenium binding under comparable conditions. PMID:16103372

  18. Evaluation of the Specificity of BP3385 for Bordetella pertussis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BP3385 has been proposed as a diagnostic PCR target for discriminating between Bordetella pertussis and other Bordetella species that also infect humans. Our results demonstrate this gene is also present in some strains of Bordetella hinzii and Bordetella bronchiseptica....

  19. Surface nitrate utilization in the Bering sea since 180 kA BP: Insight from sedimentary nitrogen isotopes

    NASA Astrophysics Data System (ADS)

    Riethdorf, Jan-Rainer; Thibodeau, Benoit; Ikehara, Minoru; Nürnberg, Dirk; Max, Lars; Tiedemann, Ralf; Yokoyama, Yusuke

    2016-03-01

    We present high-resolution records of sedimentary nitrogen (δ15Nbulk) and carbon isotope ratios (δ13Cbulk) from piston core SO201-2-85KL located in the western Bering Sea. The records reflect changes in surface nitrate utilization and terrestrial organic matter contribution in submillennial resolution that span the last 180 kyr. The δ15Nbulk record is characterized by a minimum during the penultimate interglacial indicating low nitrate utilization (~62-80%) despite the relatively high export production inferred from opal concentrations along with a significant reduction in the terrestrial organic matter fraction (mterr). This suggests that the consumption of the nitrate pool at our site was incomplete and even more reduced than today (~84%). δ15Nbulk increases from Marine Isotope Stage (MIS) 5.4 and culminates during the Last Glacial Maximum, which indicates that nitrate utilization in the Bering Sea was raised during cold intervals (MIS 5.4, 5.2, 4) and almost complete during MIS 3 and 2 (~93-100%). This is in agreement with previous hypotheses suggesting that stronger glacial stratification reduced the nutrient supply from the subeuphotic zone, thereby increasing the iron-to-nutrient ratio and therefore the nitrate utilization in the mixed surface layer. Large variations in δ15Nbulk were also recorded from 180 to 130 ka BP (MIS 6), indicating a potential link to insolation and sea-level forcing and its related feedbacks. Millennial-scale oscillations were observed in δ15Nbulk and δ13Cbulk that might be related to Greenland interstadials.

  20. Bp'S Baku-Tbilisi-Ceyhan pipeline: the new corporate colonialism.

    PubMed

    Marriott, James; Muttitt, Greg

    2006-01-01

    An international campaign was waged questioning the benefits of BP's Baku-Tbilisi-Ceyhan pipeline in an effort to avoid a "zone of sacrifice" there. This article is an offshoot of that effort and explains the contemporary struggle over the pipeline project. The authors describe the project's background and evaluate the actual and potential impacts of the project in which they consider eight areas. They also assess BP's capacity to confront resistance to the pipeline. PMID:16867890

  1. Black Phosphorus (BP) Nanodots for Potential Biomedical Applications.

    PubMed

    Lee, Hyun Uk; Park, So Young; Lee, Soon Chang; Choi, Saehae; Seo, Soonjoo; Kim, Hyeran; Won, Jonghan; Choi, Kyuseok; Kang, Kyoung Suk; Park, Hyun Gyu; Kim, Hee-Sik; An, Ha Rim; Jeong, Kwang-Hun; Lee, Young-Chul; Lee, Jouhahn

    2016-01-13

    Recently, the appeal of 2D black phosphorus (BP) has been rising due to its unique optical and electronic properties with a tunable band gap (≈0.3-1.5 eV). While numerous research efforts have recently been devoted to nano- and optoelectronic applications of BP, no attention has been paid to promising medical applications. In this article, the preparation of BP-nanodots of a few nm to <20 nm with an average diameter of ≈10 nm and height of ≈8.7 nm is reported by a modified ultrasonication-assisted solution method. Stable formation of nontoxic phosphates and phosphonates from BP crystals with exposure in water or air is observed. As for the BP-nanodot crystals' stability (ionization and persistence of fluorescent intensity) in aqueous solution, after 10 d, ≈80% at 1.5 mg mL(-1) are degraded (i.e., ionized) in phosphate buffered saline. They showed no or little cytotoxic cell-viability effects in vitro involving blue- and green-fluorescence cell imaging. Thus, BP-nanodots can be considered a promising agent for drug delivery or cellular tracking systems. PMID:26584654

  2. The Tista Megafan, a ~50 kyr Record of Drainage Development, Erosion and Weathering in the Sikkim Himalayas (Eastern India)

    NASA Astrophysics Data System (ADS)

    Abrahami, R.; Huyghe, P.; Van Der Beek, P.; Lowick, S.; Garzanti, E.; Revillon, S.; Carcaillet, J.; Chakraborty, T.

    2015-12-01

    The Tista River, a major tributary of the Brahmaputra drainage system (Eastern Himalaya) has built a fluvial deposit which extents over 16500 km2. The Tista megafan stands out because of (1) its disproportionate size compared to that of the upstream Tista River catchment (8000 km2), and (2) it has been incised about 50m by the river at the topographic front of the mountain range. Neither the timing of deposition/incision of the megafan sediments, and their potential tectonic or climatic controls have yet been investigated. We use both IRSL and 10Be cosmogenic data to respectively constrain the date of deposition and abandonment of the different lobes of the megafan. We suggest that two distal lobes developed successively downstream from a common proximal lobe. Deposition took place since ~50 ka and incision began at 4.0 +0.6/-0.4 ka at an average rate of 10.5 +0.6/-1.8 mm yr-1. In addition, petrology, isotope geochemistry (ɛNd, 87Sr/86Sr) and chemical composition performed on modern river sands and late-Quaternary megafan sediments allows characterizing (1) provenance variations through time of megafan deposits and their implication for drainage development (2) the weathering history of Sikkim recorded by the megafan deposits. Results show that the Tista fan deposits are mainly sourced from the High Himalayan Crystalline domain and the Tethyan Sedimentary Series, (consistent with high erosion rates identified in north Sikkim at millennial timescale). Variations in provenance and weathering through time recorded by the Tista megafan deposits can be linked to climatic variations with strong monsoonal precipitations penetrating further northward into the southern Tibetan plateau. Tectonic processes seem to play a minor role. Otherwise, we propose as a first hypothesis that the Kosi River has recently (at ~4 ka) captured the upper part of the Tista catchment. That could explain the particular isotopic signature of the Tista megafan deposits, its recent incision, its

  3. Peptide binding to HLA-DP proteins at pH 5.0 and pH 7.0: a quantitative molecular docking study

    PubMed Central

    2012-01-01

    Background HLA-DPs are class II MHC proteins mediating immune responses to many diseases. Peptides bind MHC class II proteins in the acidic environment within endosomes. Acidic pH markedly elevates association rate constants but dissociation rates are almost unchanged in the pH range 5.0 – 7.0. This pH-driven effect can be explained by the protonation/deprotonation states of Histidine, whose imidazole has a pKa of 6.0. At pH 5.0, imidazole ring is protonated, making Histidine positively charged and very hydrophilic, while at pH 7.0 imidazole is unprotonated, making Histidine less hydrophilic. We develop here a method to predict peptide binding to the four most frequent HLA-DP proteins: DP1, DP41, DP42 and DP5, using a molecular docking protocol. Dockings to virtual combinatorial peptide libraries were performed at pH 5.0 and pH 7.0. Results The X-ray structure of the peptide – HLA-DP2 protein complex was used as a starting template to model by homology the structure of the four DP proteins. The resulting models were used to produce virtual combinatorial peptide libraries constructed using the single amino acid substitution (SAAS) principle. Peptides were docked into the DP binding site using AutoDock at pH 5.0 and pH 7.0. The resulting scores were normalized and used to generate Docking Score-based Quantitative Matrices (DS-QMs). The predictive ability of these QMs was tested using an external test set of 484 known DP binders. They were also compared to existing servers for DP binding prediction. The models derived at pH 5.0 predict better than those derived at pH 7.0 and showed significantly improved predictions for three of the four DP proteins, when compared to the existing servers. They are able to recognize 50% of the known binders in the top 5% of predicted peptides. Conclusions The higher predictive ability of DS-QMs derived at pH 5.0 may be rationalised by the additional hydrogen bond formed between the backbone carbonyl oxygen belonging to the peptide

  4. Prevalence of the 4977-bp and 4408-bp mitochondrial DNA deletions in mesenteric arteries from patients with colorectal cancer.

    PubMed

    Li, Tao; Chen, Gui-Lan; Lan, Huan; Mao, Liang; Zeng, Bo

    2016-09-01

    Mitochondrial DNA (mtDNA) deletions are found in many diseased tissues and lead to impairment of mitochondrial functions. In this study, we found wide presence of the common 4977-bp and a novel 4408-bp deletion in the mtDNA of mesenteric arteries from patients with colorectal cancer. These two deletions were also detected in samples from healthy individuals. The content of mtDNA with the 4977-bp deletion was significantly lower in healthy controls than cancer-associated samples, and there was no significant difference for the 4408-bp deletion between the two groups. These results suggest that mtDNA in blood vessels around cancer cells may be strongly affected by oxidative stress and tend to accumulate more large-scale variations. PMID:26332461

  5. Cross-section measurement for the 10B(n, alpha)7Li reaction at 4.0 and 5.0 MeV.

    PubMed

    Zhang, Guohui; Guo, Li'an; Cao, Rongtai; Zhang, Jiaguo; Chen, Jinxiang

    2008-10-01

    Cross-sections of the (10)B(n, alpha)(7)Li reaction were measured at En=4.0 and 5.0 MeV. A gridded ionization chamber (GIC) was used as charged particle detector. Neutrons were produced through the D(d, n)(3)He reaction with a deuterium gas target. Experiments were performed at the 4.5 MV Van de Graaff accelerator of Peking University. Cross-section data of the (238)U(n, f) reaction were employed as standard. The measured cross-sections of the (10)B(n, alpha)(7)Li reaction at 4.0 and 5.0 MeV are 211+/-17 and 169+/-14 mb, respectively, and they are compared with existing results of measurements and evaluations. PMID:18387305

  6. Ab-Initio Study of Cobalt Impurity Effects on Phonon Spectra, Mechanical and Thermal Properties of Single Wall Carbon Nanotube (5,0)

    NASA Astrophysics Data System (ADS)

    Tashakori, H.; Khoshnevisan, B.; Kanjouri, F.

    2014-04-01

    We use density functional perturbation theory based on the pseudo-potential to calculate the phonon spectrum, phonon density of states, specific heat capacity and mechanical properties of pristine and cobalt doped (5,0) single wall carbon nanotube (CNT). In the calculations, we consider one Co atom in the center of the unit cell of the tube and it is shown that the pristine (5,0) CNT is nonmagnetic while the Co-doped tube becomes magnetic. Young's modulus for both systems is about 1TPa (after Co-doping it goes slightly higher) and the Poisson ratio for the pristine tube becomes quite a bit larger than the doped one. On the other hand, the calculated value of radial breath mode for the pristine CNT is in good agreement with the experimental reports while after Co-doping it is increased. In addition, heat capacity of the doped CNT is reduced, which leads to some important empirical applications.

  7. Effectiveness and Safety of the Impella 5.0 as a Bridge to Cardiac Transplantation or Durable Left Ventricular Assist Device.

    PubMed

    Lima, Brian; Kale, Parag; Gonzalez-Stawinski, Gonzalo V; Kuiper, Johannes J; Carey, Sandra; Hall, Shelley A

    2016-05-15

    Many patients with end-stage heart failure require mechanical circulatory support as a temporizing measure to enable multidisciplinary assessment for the most suitable therapeutic strategy. Impella 5.0 can be used as a bridge to decision to evaluate patients for potential recovery or bridge to next therapy (bridge to heart transplantation [BTHT] or bridge to durable left ventricular assist device or VAD [BLVAD]. Our goal was to examine single-center outcomes with the Impella 5.0 device as a bridge to next therapy (BTHT or BTLVAD). Forty patients underwent Impella 5.0 support from December 2009 to December 2015 with the intent of BTHT (n = 20) or BTLVAD (n = 20). The primary end point was survival to next therapy. Secondary end points included hemodynamic assessments and in-hospital/30-day complications. All patients were inotrope-dependent, with severely depressed left ventricular ejection fraction (12%) and renal insufficiency (creatinine 2.0 mg/dl). Most were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 2 (66%) with biventricular failure (65%). Thirty patients (75%) survived to next therapy, including transplant (n = 13), durable LVAD (n = 15), and recovery of native heart function (n = 2). No strokes or major bleeding events requiring surgery were observed. Acute renal dysfunction, bleeding requiring transfusion, hemolysis, device malfunction, limb ischemia occurred in 13 (33%), 11 (28%), 3 (8%), 4 (10%), and 1 (3%) patients, respectively. Survival rate to discharge and/or 30 days was 68% (27 of 40). Temporary support with the Impella 5.0 allows for an effective bridge to decision strategy for hemodynamic stabilization and multidisciplinary heart team assessment of critically ill patients with heart failure. In conclusion, many of these patients can be subsequently bridged to the next therapy with favorable outcomes. PMID:27061705

  8. Safety of Lifitegrast Ophthalmic Solution 5.0% in Patients With Dry Eye Disease: A 1-Year, Multicenter, Randomized, Placebo-Controlled Study

    PubMed Central

    Karpecki, Paul M.; Majmudar, Parag A.; Nichols, Kelly K.; Raychaudhuri, Aparna; Roy, Monica; Semba, Charles P.

    2016-01-01

    Purpose: To evaluate the 1-year safety of lifitegrast ophthalmic solution 5.0% in patients with dry eye disease compared with placebo. Methods: SONATA (Safety Of a 5.0% coNcentrATion of lifitegrAst ophthalmic solution) was a multicenter, randomized, prospective, double-masked, placebo-controlled phase 3 study (NCT01636206). Adults (≥18 years) with dry eye disease (Schirmer test score ≥1 and ≤10 mm; corneal staining score ≥2.0) were randomized 2:1 to lifitegrast ophthalmic solution 5.0% or placebo twice daily for 360 days. The primary objective was percentage and severity of treatment-emergent adverse events (TEAEs). Secondary objectives were ocular safety measures: corneal fluorescein staining, drop comfort, best-corrected visual acuity, slit-lamp biomicroscopy, and intraocular pressure over 7 visits. Exploratory objectives included concentration of lifitegrast in plasma. Results: The safety population comprised 331 participants (220 lifitegrast; 111 placebo). There were no serious ocular TEAEs. Overall, 53.6% of participants receiving lifitegrast experienced ≥1 ocular TEAE versus 34.2% in the placebo group; most TEAEs were mild to moderate in severity. Rates of discontinuation because of TEAEs were 12.3% (lifitegrast) versus 9.0% (placebo). The most common (>5%) TEAEs occurring in either treatment group were instillation site irritation (burning), instillation site reaction, visual acuity reduced, dry eye, and dysgeusia (change in taste). Ocular safety parameters for lifitegrast were similar to placebo. The mean plasma lifitegrast concentration at 360 days (n = 43) was below the limit of detection. There was no indication of systemic toxicity or localized infectious complications secondary to chronic immunosuppression. Conclusions: Lifitegrast ophthalmic solution 5.0% seemed safe and well tolerated in this study, with no unexpected adverse events. PMID:27055211

  9. Differential cross sections for scattering of 0.5-, 1.5-, and 5.0 keV oxygen atoms by He, N2, and O2

    NASA Technical Reports Server (NTRS)

    Schafer, D. A.; Newman, J. H.; Smith, K. A.; Stebbings, R. F.

    1987-01-01

    This paper reports measurements of absolute scattering cross sections, differential in angle, for collisions of ground-state oxygen atoms with He, N2, and O2. Data are presented for scattering of 0.5-, 1.5-, and 5.0-keV oxygen-atom projectiles in the range of laboratory frame angles between 0.06 and 5 deg. These measurements provide information relevant to calculations of the aeronomic consequences of O(+) precipitation in the earth's upper atmosphere.

  10. New Archaeointensity Result from Middle-Eastern China and Its Constraints on the Variation of the Geomagnetic Field during the last 6 kyr

    NASA Astrophysics Data System (ADS)

    Cai, S.; Jin, G.; Deng, C.; Tauxe, L.; Qin, H.; Pan, Y.; Zhu, R.

    2015-12-01

    Archaeomagnetic study is an effective way to understand the variation of the geomagnetic field over periods of hundreds to thousands of years. We have carried out archaeointensity studies on archaeological artifacts, including pottery fragments, bricks and baked clay, collected from several sites covering the middle to eastern part of China spanning the past ~6 kyr. We designed detailed rock magnetic and archaeointensity experiments in this study. Rock magnetic results indicate that the main magnetic carriers of these samples are stable magnetite or titanomagnetite with mainly fine particles of SD and SP. About 40% of the specimens in the paleointensity experiment pass the strict selection criteria and are considered to record robust intensity values. The virtual axial dipole moments (VADMs) of our sites range from ~2.5×1022 to ~15.8×1022 Am2. We record three low intensity values with VADMs of less than 3×1022 Am2, two of them comparable to the one reported by Cai et al. (2015) at ~3000 BCE while the other one comparable to those reported by Cai et al. (2014) at ~2200 BCE, which supply further evidence for the existence of 'DIPs' (decreases in paleoinetnsity) in China during the period of ~3000-2000 BCE. A high intensity value of ~16×1022 Am2 is recorded by our new data at ~1300 BCE, which may represent a new spike at this time period. The low and high values recorded by our new data update the six-fold variation between ~2200 BCE and ~1300 BCE discussed in Cai et al. (2014) to eight-fold, which may indicate a stronger geodynamic process during this period. Our new data are generally in good agreement with the published data in China, Japan and Korea at similar time periods, except the extreme low and high values discussed above, which will improve the Eastern Asian model greatly. The new data together with the published data suggest severe fluctuation of the geomagnetic field in Eastern Asia during the last 6 kyr. Vast quantities of reliable data are needed to

  11. Changes in seasonality of organic matter supply to the sea floor in the Eastern Equatorial Pacific over the last 260 kyr based on benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Ovsepyan, Ekaterina; Ivanova, Elena; Vidal, Laurence

    2015-04-01

    At present, short- and long-term variations of sea-surface biological productivity in the Eastern Equatorial Pacific have been extensively studied in order to evaluate changes in efficiency of biological carbon dioxide pump in the past. Benthic foraminiferal assemblages are investigated from the IMAGES giant Core MD02-2529 (8°12.5' N, 84° 07.5'W, w.d. 1619 m) off Costa Rica recovered the last 262 kyr according to oxygen isotope stratigraphy confirmed by 15 AMS14C dates in the upper part of the core. A predominance of high productivity species (e.g. hispid Uvigerina, U. peregrina, M. barleeanus, B. mexicana, C. carinata, T. delicata, C. wuellerstorfi, P. bulloides, Chilostomella spp., Globobulimina spp.) in benthic foraminiferal assemblages indicates intensive organic matter supply to the sea floor throughout the interval studied. CABFAC factor analysis applied for the species percentages matrix reveals that changes in taxonomic composition are described by three factors. Factor 1 is loaded mainly to U. hispida and in a less degree to U. peregrina. According to the modern ecological notion (e.g. Loubere, Fariduddin, 1999), U. hispida is associated with high and fairly constant organic matter flux to the seabed. Hence, high values of factor 1 reflect high productivity and low seasonality conditions. Factor 2 is loaded positively to U. peregrina and negatively to U. hispida. U. peregrina prefers slightly degraded organic matter, whereas U. hispida is abundant within the regions where organic matter is fresh and dominated by diatoms. Thus, we suppose that maxima of factor 2 mirror high productivity conditions with non-regular flux of organic matter to the sea floor with several events of phytoplankton blooms over the year (moderate seasonality). We believe that fresh organic matter derived from the photic layer underwent bacterial decomposition between multiple flux pulses and thereby contributed to thrift U. peregrina assemblages. Factor 3 is loaded positively to M

  12. Hydrological and thermal changes along the last 2.7 kyr in the central-western Mediterranean based on a multi-archive approach: speleothem and marine sediments

    NASA Astrophysics Data System (ADS)

    Cisneros, Mercè; Cacho, Isabel; Fornós, Joan J.; Moreno, Ana; Stoll, Heather; Edwards, Larry; Cheng, Hai; Frigola, Jaime

    2016-04-01

    Climatic conditions over the last 2.7 kyr are reconstructed in base to six speleothems from a cave in Mallorca and a group of sediment cores from the Menorca Rise. Speleothem records provide a solid chronology in base to high resolution U/Th dating. Both δ 13C and particularly δ 18O records show pronounced oscillations related to pre-roman times as the Dark Middle Ages, the Medieval Climate Anomaly and the Little Ice Age. The geochemical proxies from the six studied speleothems have been stacked in a unique record, which provides decadal-multidecadal resolution. In parallel, Sea Surface Temperature (SST) conditions have been reconstructed in base to Globigerina bulloides-Mg/Ca ratios from a group of multicore records, and they have been combined with δ18O data to reconstruct changes in the evaporation-precipitation ratio of the basin. These records have also been stacked in a single anomaly curve after the accurate construction of robust multi-proxy chronologies (Cisneros et al., under evaluation). The comparison of the marine and speleothem records reveal the occurrence of synchronous changes in both SST and humidity conditions over land along the last 2.7 kyr, although the relationship of these two climatic variables changed along the different climatic events. These results support that the driest conditions occurred during part of the Roma Classic Period and also during the Medieval Climate Anomaly when climate conditions were mostly warm, but also during the second part of the Little Ice Age when cold conditions dominated. This combined land-sea proxy approach offers a powerful tool to reconstruct past climate variability with highly precise chronologies. REFERENCES: M. Cisneros, I. Cacho, J. Frigola, M. Canals, P. Masqué, B. Martrat, F. Lirer, and G. Margaritelli. Sea surface temperature variability in the central-western Mediterranean Sea during the last 2700 years: a multi-proxy and multi-record approach. Submitted on 28 Sep 2015 for open discussion on

  13. An early Pleistocene Mg/Ca-δ18O record from the Gulf of Mexico: Evaluating ice sheet size and pacing in the 40-kyr world

    NASA Astrophysics Data System (ADS)

    Shakun, J. D.; Raymo, M. E.; Lea, D. W.; Klinkhammer, G. P.

    2011-12-01

    Two decades ago, Joyce (1993) presented a planktonic δ18O record from ODP site 625 in the Gulf of Mexico and interpreted numerous light isotope excursions beginning at 2.5 Ma as reflecting Laurentide Ice Sheet meltwater pulses down the Mississippi River. This finding implied an extensive early Pleistocene (EP) ice sheet, seemingly at odds with the smaller global ice volume inferred from benthic δ18O at this time. The till record on land confirms that ice extended into the central U.S at least twice during the EP. We are developing a high-resolution paired Mg/Ca-δ18O record from site 625 to reconstruct sea surface temperatures and salinity over the EP and evaluate Joyce's meltwater interpretation. Initial results of our temperature-corrected δ18O record confirm his inference of large meltwater spikes at the onset of the Quaternary. Our approach could weigh in on several hypotheses concerning the size and pacing of Quaternary ice sheets. The Integrated Insolation hypothesis explains the puzzling lack of precession variability in marine δ18O during the 40-kyr world by arguing that ice sheets are sensitive to insolation integrated over the summer, which is largely controlled by obliquity. The Antiphase Hypothesis, on the other hand, suggests that EP precession variability was antiphased between northern and southern ice sheets, canceling out and leaving the in-phase obliquity component to dominate the marine δ18O record. This view implies that marine δ18O may underestimate Northern Hemisphere ice volume during the EP. The Regolith Hypothesis takes the small ice volume implied by marine δ18O at face value and, together with the large ice area suggested from Joyce's meltwater spikes and the mid-continent till record, argues that EP ice sheets had a flat-like-a-pancake geometry, which it attributes to fast ice flow over a deformable bed. Erosion of this bed in the mid-Pleistocene may then have led to larger, more sluggish ice sheets and the transition from 40 to

  14. Erosional History of the Himalayan Range Since the Last 180 kyr: Clay Mineralogical and Geochemical Investigations From the Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Joussain, R.; Liu, Z.; Christophe, C.

    2014-12-01

    Himalayan range and Indo-Gangetic plain are drained by one of the world's largest river system of the world: the Ganges-Brahmaputra Rivers. This river system is the first in term of sediment transport and thus constitute an interesting region to establish a relation between erosion and climate. Sediments from the Bay of Bengal indicate that the strength of summer monsoon rainfall is an important factor driving weathering and erosion of the Himalaya. Results of a high-resolution clay mineralogy study combined with major elements geochemistry and oxygen isotopes stratigraphy are reported for a deep-sea piston core collected 300 km off the Ganges-Brahmaputra Rivers estuary in the northern part of the Bay in Bengal. In this study, the top part (first 13.5 m) of Core MD12-3412 covers the last climatic cycle (last 180 kyr). This core reveals a monsoon-controlled chemical weathering and physical erosion history during the last 180 kyr in the Himalayan range and the Ganges-Brahmaputra Basin. Data show the contribution of Ganges-Brahmaputra Rivers, which drain the Himalayan range and the Indo-Gangetic plain. Clay mineral assemblages are dominated by illite and smectite, with lesser abundance of chlorite and kaolinite. Smectite/(illite + chlorite) and illite chemistry index are used as indices of chemical weathering rates. Thirty five new samples for ɛNd(0) analyses were selected (in turbidite and hemipelagic layers) during glacial and interglacial periods. Himalayan range is characterized by ɛNd(0) ≈ -16, whereas ɛNd(0) values along the Arakan coast are around -8. In this work we compared with ɛNd(0) values obtained previously on the free-carbonated fraction on Core MD77-180 which show that sediment from the eastern Bay of Bengal results from the mixing of material from the Himalayan and Indo-Burman ranges (with an average value of ɛNd(0) ≈ -13 for the last climatic cycle). These analyses give us information about the material coming from Ganges-Brahmaputra Rivers

  15. Oxygen isotopes of Pacific seawater, 0-40 kyr, based on d18O and Mg/Ca of benthic and planktic foraminifera: relation to deglacial sealevel rise.

    NASA Astrophysics Data System (ADS)

    Mix, A. C.; Klinkhammer, G. P.

    2007-12-01

    Combining high resolution (~200 year sample resolution) oxygen and carbon isotope measurements and Mg/Ca analyses in planktic (G. ruber and N. dutertrei) and benthic foraminifera (Uvigerina sp.; use of infaunal benthics minimizes likely CO3= effects) from the mid-depth eastern Pacific provides for detailed estimates of changing d18O of seawater over the past 40 kyr at ODP Site 1242. The key to this analysis is improved precision of the Mg/Ca analyses based on a new generation of high precision flow-through time-resolved analysis (FT-TRA) (e.g., average internal precision for Mg/Ca is now +/-0.005 benthic, and +/-0.015 planktic). This method is relatively insensitive to mild dissolution of heterogeneous shells, and thus requires no corrections for preservation. The change in seawater d18O (at 1364 m depth) between the Holocene and Last Glacial Maximum is 1.2 +/- 0.04 permil when averaged over the stages, consistent with pore-water diffusion estimates; however, millennial scale events (which the pore-water data cannot detect) bring the total range up to about 1.6 permil. Are such short-term events related to sealevel change, or do they reflect changing watermasses? Measurements of d13C data (C. wuellerstorfi), sensitive to modern subsurface watermass gradients, are not highly correlated to short- term changes in d18Oseawater suggesting a transient response to ice volume changes. Glacial weakening of AAIW (salty, high d18O, high d13C) relative to north Pacific watermasses (fresher, lower d18O, low d13C) suggest that the benthic d18Oseawater may underestimate total local changes related to ice volume (with a caveat regarding proper scaling of benthic Mg/Ca to temperature). Benthic d18Oseawater falls through the deglaciation in steps, starting at 18 cal ka, with maximum rates of change at 14-15 ka, and with secondary rapid steps at 16-17 ka and 10-11 kar. Planktic foraminifera yield smaller glacial-interglacial d18Oseawater values, with Holocene-to-LGM stage- average

  16. Suzaku observations of two diffuse hard X-ray source regions, G22.0+0.0 and G23.5+0.1

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shigeo; Sumita, Mayu; Bamba, Aya

    2016-06-01

    G22.0+0.0 and G23.5+0.1 are diffuse hard X-ray sources discovered in the ASCA Galactic Plane Survey. We present Suzaku results of spectral analysis for these sources. G22.0+0.0 is confirmed to be a largely extended emission. Its spectra were represented by a highly absorbed power-law model with a photon index of 1.7 ± 0.3 and a moderately absorbed thermal emission with a temperature of 0.34^{+0.11}_{-0.08}keV. The difference in the NH values between the two components suggests that the thermal component is unrelated to the power-law component and is a foreground emission located in the same line of sight. G23.5+0.1 is an extended source with a size of ˜3{^'.}5. Its spectra were fitted with an absorbed power-law model with a photon index of 2.4^{+0.5}_{-0.4}. The spatial and spectral properties show that both sources are candidates for old pulsar wind nebulae (PWNe). In addition to the extended sources, we analyzed spectra of three point sources found in the observed fields. Based on the spectral features, we discuss the origin of the sources.

  17. Mechanisms Directing the Nuclear Localization of the CtBP Family Proteins

    PubMed Central

    Verger, Alexis; Quinlan, Kate G. R.; Crofts, Linda A.; Spanò, Stefania; Corda, Daniela; Kable, Eleanor P. W.; Braet, Filip; Crossley, Merlin

    2006-01-01

    The C-terminal binding protein (CtBP) family includes four proteins (CtBP1 [CtBP1-L], CtBP3/BARS [CtBP1-S], CtBP2, and RIBEYE) which are implicated both in transcriptional repression and in intracellular trafficking. However, the precise mechanisms by which different CtBP proteins are targeted to different subcellular regions remains unknown. Here, we report that the nuclear import of the various CtBP proteins and splice isoforms is differentially regulated. We show that CtBP2 contains a unique nuclear localization signal (NLS) located within its N-terminal region, which contributes to its nuclear accumulation. Using heterokaryon assays, we show that CtBP2 is capable of shuttling between the nucleus and cytoplasm of the cell. Moreover, CtBP2 can heterodimerize with CtBP1-L and CtBP1-S and direct them to the nucleus. This effect strongly depends on the CtBP2 NLS. PXDLS motif-containing transcription factors, such as BKLF, that bind CtBP proteins can also direct them to the nucleus. We also report the identification of a splice isoform of CtBP2, CtBP2-S, that lacks the N-terminal NLS and localizes to the cytoplasm. Finally, we show that mutation of the CtBP NADH binding site impairs the ability of the proteins to dimerize and to associate with BKLF. This reduces the nuclear accumulation of CtBP1. Our results suggest a model in which the nuclear localization of CtBP proteins is influenced by the CtBP2 NLS, by binding to PXDLS motif partner proteins, and through the effect of NADH on CtBP dimerization. PMID:16782877

  18. Marine04 Marine radiocarbon age calibration, 26 ? 0 ka BP

    SciTech Connect

    Hughen, K; Baille, M; Bard, E; Beck, J; Bertrand, C; Blackwell, P; Buck, C; Burr, G; Cutler, K; Damon, P; Edwards, R; Fairbanks, R; Friedrich, M; Guilderson, T; Kromer, B; McCormac, F; Manning, S; Bronk-Ramsey, C; Reimer, P; Reimer, R; Remmele, S; Southon, J; Stuiver, M; Talamo, S; Taylor, F; der Plicht, J v; Weyhenmeyer, C

    2004-11-01

    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration datasets extend an additional 2000 years, from 0-26 ka cal BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically dated tree-ring samples, converted with a box-diffusion model to marine mixed-layer ages, cover the period from 0-10.5 ka cal BP. Beyond 10.5 ka cal BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific {sup 14}C reservoir age information to provide a single global marine mixed-layer calibration from 10.5-26.0 ka cal BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the radiocarbon age to calculate the underlying calibration curve. The marine datasets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring datasets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al.

  19. Linkages between rapid climate variability and deep-sea benthic foraminifera in the deep Subantarctic South Atlantic during the last 95 kyr

    NASA Astrophysics Data System (ADS)

    Diz, Paula; Barker, Stephen

    2015-06-01

    We present a high-resolution record of benthic foraminifera fauna from a sediment core retrieved from the South Cape Basin (Subantarctic South Atlantic) spanning the last glacial cycle (95 kyr). Information provided by benthic foraminiferal assemblages together with paleoclimate proxies from the same core allow us to interpret changes in the style of primary production (episodic versus sustained) in relation to abrupt climate oscillations. Our results indicate that fluctuations in the abundance of the phytodetritus-related species, Epistominella exigua, are concomitant with millennial-scale high-latitude climate perturbations. Episodic phytoplankton blooms increased during a negative mode of the bipolar seesaw, irrespective of the magnitude of the perturbation (i.e., Heinrich stadial versus non-Heinrich stadial events). We provide a hypothesis linking the frequency and intensity of these events to atmospheric perturbations, interhemispheric climate variability, and millennial-scale changes in atmospheric CO2. A notable exception to the overall pattern is the generally high abundance of E. exigua across the globally synchronous onset of glacial marine oxygen isotope stage (MIS) 4, a period generally characterized by increased dustiness and low-quality organic carbon as inferred by the percentage of the nonphytodetritus species. This highlights the special characteristics governing the onset of MIS 4 in the Subantarctic.

  20. A 100 Myr history of the carbon cycle based on the 400 kyr cycle in marine δ13C benthic records

    NASA Astrophysics Data System (ADS)

    Paillard, Didier; Donnadieu, Yannick

    2014-12-01

    Documenting the past coevolution of Earth temperatures and of the carbon cycle is of paramount importance for our understanding of climate dynamics. Atmospheric CO2 is well constrained over the last million years through direct measurements in air bubbles from Antarctic ice cores. For older times, many different and sometimes conflicting proxies have been suggested. Here we provide a new methodology to constrain the carbon cycle in the past, based on marine benthic δ13C records. Marine δ13C data are recording a persistent 400 kyr cycle, with an amplitude primarily linked to the total amount of carbon in the ocean, or dissolved inorganic carbon (DIC). By extracting this amplitude from published records, we obtain a new strong constraint on the 100 Myr history of Earth's carbon cycle. The obtained Cenozoic evolution of DIC is in surprisingly in a good agreement with existing reconstructions of pCO2, suggesting that pCO2 is mostly driven by DIC changes over this period. In contrast, we find no strong decreasing trend in DIC between the Cretaceous and the Cenozoic, suggesting that Cretaceous atmospheric pCO2 levels were limited, and high temperatures at this time should be explained by other mechanisms. Alternatively, high Cretaceous atmospheric pCO2 could occur as a consequence of changes in oceanic chemistry but not carbon content.

  1. Preliminary Geological Findings on the BP-1 Simulant

    NASA Technical Reports Server (NTRS)

    Rickman, D. L.

    2010-01-01

    The following is a summation of information and discussion between Doug Stoeser of the USGS and Doug Rickman of NASA in February and March, 2010 pertaining to the BP-1 simulant. The analytical results and the bulk of the text are from communications from Dr. Stoeser. The BP-1 simulant is made from Black Point Basalt Flow, San Francisco Volcanic Field, northern Arizona. There is an aggregate (road metal) quarry on the northern margin of the flow towards the west end that was used as a Desert Research and Technology Studies (Desert RATS) analog test site. Silty material from this site was also used in laboratory tests and found to have geotechnical properties similar to the LHT-2M and Chenobi regolith simulants and is being proposed as a possible simulant for geotechnical use. It currently has the designation of BP-1 (Black Point 1). Figure

  2. Endothelin-1 and the kidney – beyond BP

    PubMed Central

    Dhaun, Neeraj; Webb, David J; Kluth, David C

    2012-01-01

    Since its discovery over 20 years ago endothelin-1 (ET-1) has been implicated in a number of physiological and pathophysiological processes. Its role in the development and progression of chronic kidney disease (CKD) is well established and is an area of ongoing intense research. There are now available a number of ET receptor antagonists many of which have been used in trials with CKD patients and shown to reduce BP and proteinuria. However, ET-1 has a number of BP-independent effects. Importantly, and in relation to the kidney, ET-1 has clear roles to play in cell proliferation, podocyte dysfunction, inflammation and fibrosis, and arguably, these actions of ET-1 may be more significant in the progression of CKD than its prohypertensive actions. This review will focus on the potential role of ET-1 in renal disease with an emphasis on its BP-independent actions. PMID:22670597

  3. Preliminary Geological Findings on the BP-1 Simulant

    NASA Technical Reports Server (NTRS)

    Stoeser, D. B.; Rickman, D. L.; Wilson, S.

    2010-01-01

    A waste material from an aggregate producing quarry has been used to make an inexpensive lunar simulant called BP-1. The feedstock is the Black Point lava flow in northern Arizona. Although this is part of the San Francisco volcanic field, which is also the source of the JSC-1 series feedstock, BP-1 and JSC-1 are distinct. Chemically, the Black Point flow is an amygdaloidal nepheline-bearing basalt. The amygdules are filled with secondary minerals containing opaline silica, calcium carbonate, and ferric iron minerals. X-ray diffraction (XRD) detected approximately 3% quartz, which is in line with tests done by the Kennedy Space Center Industrial Hygiene Office. Users of this material should use appropriate protective equipment. XRD also showed the presence of significant halite and some bassanite. Both are interpreted to be evaporative residues due to recycling of wash water at the quarry. The size distribution of BP-1 may be superior to some other simulants for some applications.

  4. High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones

    PubMed Central

    Lee, Jung Won; Nam, Ryoung Hee; Kim, Jung Mogg; Park, Jong Youn; Lee, Sun Min; Kim, Joo Sung; Lee, Dong Ho; Jung, Hyun Chae

    2015-01-01

    Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma. PMID:26416863

  5. MetaCluster 5.0: a two-round binning approach for metagenomic data for low-abundance species in a noisy sample

    PubMed Central

    Wang, Yi; Leung, Henry C.M.; Yiu, S.M.; Chin, Francis Y.L.

    2012-01-01

    Motivation: Metagenomic binning remains an important topic in metagenomic analysis. Existing unsupervised binning methods for next-generation sequencing (NGS) reads do not perform well on (i) samples with low-abundance species or (ii) samples (even with high abundance) when there are many extremely low-abundance species. These two problems are common for real metagenomic datasets. Binning methods that can solve these problems are desirable. Results: We proposed a two-round binning method (MetaCluster 5.0) that aims at identifying both low-abundance and high-abundance species in the presence of a large amount of noise due to many extremely low-abundance species. In summary, MetaCluster 5.0 uses a filtering strategy to remove noise from the extremely low-abundance species. It separate reads of high-abundance species from those of low-abundance species in two different rounds. To overcome the issue of low coverage for low-abundance species, multiple w values are used to group reads with overlapping w-mers, whereas reads from high-abundance species are grouped with high confidence based on a large w and then binning expands to low-abundance species using a relaxed (shorter) w. Compared to the recent tools, TOSS and MetaCluster 4.0, MetaCluster 5.0 can find more species (especially those with low abundance of say 6× to 10×) and can achieve better sensitivity and specificity using less memory and running time. Availability: http://i.cs.hku.hk/~alse/MetaCluster/ Contact: chin@cs.hku.hk PMID:22962452

  6. SD 1313-0019: Another Second-generation Star with [Fe/H] = -5.0, Observed with the Magellan Telescope

    NASA Astrophysics Data System (ADS)

    Frebel, Anna; Chiti, Anirudh; Ji, Alexander P.; Jacobson, Heather R.; Placco, Vinicius M.

    2015-09-01

    We present a Magellan/MIKE high-resolution (R ˜ 35,000) spectrum of the ancient star SD 1313-0019, which has an iron abundance of {{[Fe/H]}}=-5.0, paired with a carbon enhancement of {{[C/Fe]}}˜ 3.0. The star was initially identified by Allende Prieto et al. in the BOSS survey. Its medium-resolution spectrum suggested a higher metallicity of {{[Fe/H]}}=-4.3 due to the Ca ii K line blending with a CH feature, which is a common issue related to the search for the most iron-poor stars. This star joins several other similar stars with {{[Fe/H]}}≲ -5.0 that all display a combination of low-iron and high-carbon abundances. Other elemental abundances of SD 1313-0019 follow that of more metal-rich halo stars. Fitting the abundance pattern with yields of Population III supernovae suggests that SD 1313-0019 had only one massive progenitor star with 20-30 {M}⊙ that must have undergone a mixing and fallback episode. Overall, there are now five stars known with {{[Fe/H]}}≲ -5.0 (1D local thermodynamic equilibrium abundances). This ever-increasing population of carbon-rich, iron-deficient stars can potentially constrain nucleosynthesis in Population III stars and their supernova explosions, the formation mechanisms of the first low-mass stars, and the nature of the first galaxies. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  7. Synthesis and structural studies of Sr 2Co 2- xAl xO 5, 0.3⩽ x⩽0.5

    NASA Astrophysics Data System (ADS)

    Lindberg, F.; Svensson, G.; Istomin, S. Ya.; Aleshinskaya, S. V.; Antipov, E. V.

    2004-04-01

    Sr 2Co 2- xAl xO 5, 0.3⩽ x⩽0.5, with a perovskite related structure has been synthesized. The XRD powder patterns showed reflections from the basic cubic perovskite structure along with some additional weak superstructure reflections. Electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM) studies show that crystallites of Sr 2Co 2- xAl xO 5 consist of small intergrown differently oriented domains, about 40 Å in diameter, with brownmillerite structure.

  8. Cross section measurement for the (95)Mo(n, alpha)(92)Zr reaction at 4.0, 5.0 and 6.0MeV.

    PubMed

    Zhang, Guohui; Wu, Hao; Zhang, Jiaguo; Liu, Jiaming; Yin, Yuxiang; Chen, Jinxiang; Gledenov, Yu M; Sedysheva, M V; Khuukhenkhuu, G; Koehler, P E; Szalanski, P J

    2010-01-01

    Measurements of cross sections of the (95)Mo(n, alpha)(92)Zr reaction at E(n)=4.0, 5.0 and 6.0MeV were carried out at the 4.5MV Van de Graaff of Peking University, China. A twin gridded ionization chamber and two large-area (95)Mo samples were adopted. Fast neutrons were produced through the D(d, n)(3)He reaction by using a deuterium gas target. A small (238)U fission chamber was employed for absolute neutron flux determination. Present data are compared with existing evaluations and measurement. PMID:19811925

  9. Melting of carbonated pelites at 2.5-5.0 GPa, silicate-carbonatite liquid immiscibility, and potassium-carbon metasomatism of the mantle

    NASA Astrophysics Data System (ADS)

    Thomsen, Tonny B.; Schmidt, Max W.

    2008-03-01

    Melting experiments on a Fe-rich carbonate-saturated pelite were performed at 850-1300 °C and 2.5-5.0 GPa to define melting relations, melt compositions, and the conditions under which carbonates remain residual. In the selected fertile bulk composition, 30 wt.% potassic granite (2.5 GPa) or phonolite (5.0 GPa) melt is generated at the fluid-absent solidus. The temperature of the latter increases from 900 °C at 2.4 GPa to 1070 °C at 5.0 GPa. Phengite + quartz/coesite control initial silicate melting and melt productivity through the reaction phengite + quartz/coesite +clinopyroxene + calcite = silicate melt + kyanite + garnet, which leaves most of the Fe-Mg-calcite in the residue. Na remains compatible in clinopyroxene (DNacpx/melt = 3.1 to 7.3 at the fluid-absent solidus), resulting in silicate melts with K2O/Na2O wt-ratios of 5.8-8.6. Such highly potassic carbonated silicate melts represent ideal metasomatic agents for the source mantle of group II kimberlites. From 3.7 to 5.0 GPa, Fe-Mg-calcite disappears only through the formation of Ca-carbonatite at 1100 °C. The experiments provide a possible source for Ca-carbonatites in combination with alkaline granitic to phonolitic melts at temperatures unlikely to be achieved during ongoing subduction. Large scale carbonate transfer to the subarc mantle can thus only be achieved when burying rates slow considerably down or subducted crust becomes incorporated into the mantle. Consequently, it is likely that carbonates will not be extensively mobilized in a typical subarc region, thus extending and confirming earlier results from subsolidus studies (Connolly, J.A.D., 2005. Computation of phase equilibria by linear programming: a tool for geodynamic modelling and its application to subduction zone decarbonation. Earth Planet. Sci. Lett. 236, 524-541.), that > 70-80% of the subducted carbonate will bypass the volcanic arc region and get buried to larger depths.

  10. 200-BP-5 operable unit treatability test report

    SciTech Connect

    1996-04-01

    The 200-BP-5 Operable Unit was established in response to recommendations presented in the 200 East Groundwater Aggregate Area Management Study Report (AAMSR) (DOE-RL 1993a). Recognizing different approaches to remediation, the groundwater AAMSR recommended separating groundwater from source and vadose zone operable units and subdividing 200 East Area groundwater into two operable units. The division between the 200-BP-5 and 200-PO-1 Operable Units was based principally on source operable unit boundaries and distribution of groundwater plumes derived from either B Plant or Plutonium/Uranium Extraction (PUREX) Plant liquid waste disposal sites.

  11. Cloud point extraction of vanadium in parenteral solutions using a nonionic surfactant (PONPE 5.0) and determination by flow injection-inductively coupled plasma optical emission spectrometry.

    PubMed

    Wuilloud, Gustavo M; de Wuilloud, Jorgelina C A; Wuilloud, Rodolfo G; Silva, Maria F; Olsina, Roberto A; Martinez, Luis D

    2002-10-16

    A preconcentration and determination methodology for vanadium at trace levels in parenteral solutions was developed. Cloud point extraction was successfully employed for the preconcentration of vanadium prior to inductively coupled plasma atomic optical emission spectrometry (ICP-OES) coupled to a flow injection (FI) system. The vanadium was extracted as vanadium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol [V-(5-Br-PADAP)] complex, at pH 3.7 mediated by micelles of the nonionic surfactant polyoxyethylene (5.0) nonylphenol (PONPE 5.0). The extracted surfactant-rich phase (100 mul) was mixed with 100 mul of ethanol and this final volume injected into ICP-OES for the vanadium determination. Under these conditions, the 50 ml sample solution preconcentration allowed raising an enrichment factor of 250-fold; however, it was possible to obtain a theoretical enrichment factor of 500-fold. The lower limit of detection (LOD) obtained under the optimal conditions was 16 ng l(-1). The precision for 10 replicate determinations at the 2.0 mug l(-1) V level was 2.3% relative standard deviation (RSD), calculated with the peak heights. The calibration graph using the preconcentration system for vanadium was linear with a correlation coefficient of 0.9996 at levels near the detection limits up to at least 50 mug l(-1). The method was successfully applied to the determination of vanadium in parenteral solution samples. PMID:18968790

  12. Statistical characteristics of seismo-ionospheric GPS TEC disturbances prior to global Mw ≥ 5.0 earthquakes (1998-2014)

    NASA Astrophysics Data System (ADS)

    Shah, Munawar; Jin, Shuanggen

    2015-12-01

    Pre-earthquake ionospheric anomalies are still challenging and unclear to obtain and understand, particularly for different earthquake magnitudes and focal depths as well as types of fault. In this paper, the seismo-ionospheric disturbances (SID) related to global earthquakes with 1492 Mw ≥ 5.0 from 1998 to 2014 are investigated using the total electron content (TEC) of GPS global ionosphere maps (GIM). Statistical analysis of 10-day TEC data before global Mw ≥ 5.0 earthquakes shows significant enhancement 5 days before an earthquake of Mw ≥ 6.0 at a 95% confidence level. Earthquakes with a focal depth of less than 60 km and Mw ≥ 6.0 are presumably the root of deviation in the ionospheric TEC because earthquake breeding zones have gigantic quantities of energy at shallower focal depths. Increased anomalous TEC is recorded in cumulative percentages beyond Mw = 5.5. Sharpness in cumulative percentages is evident in seismo-ionospheric disturbance prior to Mw ≥ 6.0 earthquakes. Seismo-ionospheric disturbances related to strike slip and thrust earthquakes are noticeable for magnitude Mw6.0-7.0 earthquakes. The relative values reveal high ratios (up to 2) and low ratios (up to -0.5) within 5 days prior to global earthquakes for positive and negative anomalies. The anomalous patterns in TEC related to earthquakes are possibly due to the coupling of high amounts of energy from earthquake breeding zones of higher magnitude and shallower focal depth.

  13. Size effects on the structural, electronic, and optical properties of (5,0) finite-length carbon nanotube: An ab-initio electronic structure study

    NASA Astrophysics Data System (ADS)

    Tarighi Ahmadpour, Mahdi; Hashemifar, S. Javad; Rostamnejadi, Ali

    2016-07-01

    We use density functional computations to study the zero temperature structural, electronic, magnetic, and optical properties of (5,0) finite carbon nanotubes (FCNT), with length in the range of 4-44 Å. It is found that the structural and electronic properties of (5,0) FCNTs, in the ground state, converge at a length of about 30 Å, while the excited state properties exhibit long-range edge effects. We discuss that curvature effects enhance energy gap of FCNTs, in contrast to the known trend in the periodic limit. It is seen that compensation of curvature effects in two special small sizes may give rise to spontaneous magnetization. The obtained cohesive energies provide some insights into the effects of environment on the growth of FCNTs. The second-order difference of the total energies reveals an important magic size of about 15 Å. The optical and dynamical magnetic responses of the FCNTs to polarized electromagnetic pulses are studied by time dependent density functional theory. The results show that the static and dynamic magnetic properties mainly come from the edge carbon atoms. The optical absorption properties are described in terms of local field effects and characterized by Casida linear response method.

  14. The AKARI 2.5-5.0 μm Spectral Atlas of Type-1 Active Galactic Nuclei: Black Hole Mass Estimator, Line Ratio, and Hot Dust Temperature

    NASA Astrophysics Data System (ADS)

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon; Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Oyabu, Shinki; Takagi, Toshinobu; Ohyama, Youichi; Lee, Seong-Kook

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ~1100 K and ~220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  15. BP chief scientist nominated for senior energy role

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2014-01-01

    The Obama administration has nominated BP's chief scientist Ellen Williams to be director of the Advanced Research Projects Agency-Energy (ARPA-E), which was created in 2007 to fund "high-risk, high-reward" research into novel energy technologies that are too early for investment by the private sector.

  16. Volcanic evolution of an active magmatic rift segment on a 100 Kyr timescale: exposure dating of lavas from the Manda Hararo/Dabbahu segment of the Afar Rift

    NASA Astrophysics Data System (ADS)

    Medynski, S.; Williams, A.; Pik, R.; Burnard, P.; Vye, C.; France, L.; Ayalew, D.; Yirgu, G.

    2012-12-01

    In the Afar depression (Ethiopia), extension is already organised along rift segments which morphologically resemble oceanic rifts. Segmentation here results from interactions between dyke injection and volcanism, as observed during the well documented 2005 event on the Dabbahu rift segment. During this tectono-volcanic crisis, a megadyke was injected, followed by 12 subsequent dike intrusions, sometimes associated with fissure flow eruptions. Despite the accurate surveying of the magmatic and tectonic interplay during this event via remote sensing techniques, there is a lack of data on timescales of 1 to 100 kyr, the period over which the main morphology of a rift is acquired. The Dabbahu rift segment represents an ideal natural laboratory to study the evolution of rift morphology as a response to volcanic and tectonic influences. It is possible to constrain the timing of fault growth relative to the infilling of the rift axial depression by lava flows, and to assess the influence of the different magma bodies involved in lava production along the rift-segment. We use cosmogenic nuclides (3He) to determine the ages of young (<100 kyr) lava flows and to date the initiation and movement of fault scarps which cut the lavas. Combined with major & trace element compositions, field mapping and digital cartography (Landsat, ASTER and SPOT imagery), the rift geomorphology can be linked to the magmatic and tectonic history defined by surface exposure dating. The results show that over the last 100 ka the Northern part of the Dabbahu segment was supplied by two different magma reservoirs which can be identified based on their distinctive chemistries. The main reservoir is located beneath Dabbahu volcano, and has been supplied with magma for at least 72 ka. This magmatic centre supplies magma to most of the northern third of the rift segment. The second reservoir is located further south, on the axis, close to the current mid-segment magma chamber, which was responsible for

  17. Sediment transport process and East Asian monsoon evolution during the last 410 kyr in the northern South China Sea: a multi-proxy approach

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Kissel, Catherine

    2015-04-01

    Terrigenous detrital materials buried at sea is a book documenting their whole life, including the continental environment where they originated from and the transport process they experienced. In order to reconstruct the East Asian monsoon evolution in late Quaternary, we need to read this book correctly. The key problem is to well understand the proxies and pick the right ones, because most of them are affected by several factors. In this study, clay and magnetic mineralogical measurements and geochemical XRF analyses were conducted on Core MD12-3432 taken from the northern South China Sea at 2125 m water depth during the CIRCEA cruise organized within Franco-Chinese LIA-MONOCL framework on board the R.V. Marion Dufresne. The age model is derived from both carbonate and magnetic stratigraphy. The clearly identified Laschamp and Iceland Basin geomagnetic excursions are used as tie points. Coupled earth magnetic field paleointensity and carbonate content record calibrated from XRF core scanned calcium intensity, we established a robust age model, indicating that Core MD12-3432 covers the last 410 kyr with an average sedimentation rate of 12.4 cm/kyr. The calibrated XRF-scan data provide high-resolution Ti/Ca, Al/Si and K/Al ratios. Ti/Ca and Al/Si ratios vary in phase, indicating strong clastic flux and short transport distances during glacials. Variations in K/Al ratio show an independent pattern, suggesting that temperature-driven chemical weathering is not the main control factor. Special attention needs therefore to be paid to the transport process. For that purpose, anisotropy of magnetic susceptibility was measured on discrete samples at 50 cm intervals. Orientations of the principal anisotropy axes could be reconstructed, using the NRM declination to orient the core in the horizontal plane. The maximum axis is relatively well oriented in the stratigraphic plane of the sedimentary magnetic fabric. A 90° shift is observed at the MIS 5-6 boundary, suggesting a

  18. Phase structure and piezoelectric properties of (1-x)K0.48Na0.52Nb0.95Sb0.05O3-x(Bi0.5Na0.5)0.9(Li0.5Ce0.5)0.1ZrO3 lead-free piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Xing, Jie; Tan, Zhi; Jiang, Laiming; Chen, Qiang; Wu, Jiagang; Zhang, Wen; Xiao, Dingquan; Zhu, Jianguo

    2016-01-01

    (1-x)K0.48Na0.52Nb0.95Sb0.05O3-x(Bi0.5Na0.5)0.9(Li0.5Ce0.5)0.1ZrO3 [(1-x)KNNS-xBNLCZ] lead-free piezoceramics were prepared by the conventional solid state sintering method. The effects of BNLCZ contents on their phase structure, microstructure, and piezoelectric properties were investigated. All the samples show a pure perovskite structure, and no secondary phases were formed in the detected range. The rhombohedral and tetragonal phases of (1-x)KNNS-xBNLCZ coexist in the composition range of 0.0325 ≤ x ≤ 0.0425 at room temperature. A remarkably strong piezoelectricity was obtained by the addition of appropriate BNLCZ contents. The excellent piezoelectric properties of the ceramics with x = 0.04 were obtained: d33 ˜ 485 pC/N, kp ˜ 48%, and TC ˜ 227 °C. All the results show that the introduction of (Bi0.5Na0.5)0.9(Li0.5Ce0.5)0.1ZrO3 is a very effective way to form the rhombohedral and tetragonal phase coexistence of potassium-sodium niobate-based ceramics, which can improve its piezoelectric properties.

  19. Chronological constraints on Cordilleran Ice Sheet glaciomarine sedimentation from core MD02-2496 off Vancouver Island (western Canada)

    NASA Astrophysics Data System (ADS)

    Cosma, T. N.; Hendy, I. L.; Chang, A. S.

    2008-05-01

    Chronology based on 46 radiocarbon dates has been generated for MD02-2496, western Vancouver Island, Canada. Subsequent correlation between glaciomarine sedimentary sequences within the core and the terrestrial stratigraphy of the Cordilleran Ice Sheet for the last 50 ka provide new insight into Cordilleran Ice Sheet processes. Glaciomarine sedimentation associated with the most recent advance (Fraser Glaciation) of the Cordilleran Ice Sheet began at 30.5 cal kyr BP (˜25 14C kyr BP). Extremely high sedimentation rates indicate the ice sheet became proximal to the site at ˜19.5 cal kyr BP (16 14C kyr BP). Deposition of ice rafted detritus (IRD) began at ˜17 cal kyr BP (14 14C kyr BP), and abruptly terminated at ˜16.2 cal kyr BP (13.5 14C kyr BP) indicating rapid regional ice sheet retreat. A minor IRD event followed at ˜14.7 cal kyr BP (12.5 14C kyr BP). Glaciomarine sediment deposition abruptly ended at 10.2 cal kyr BP (˜8.8 14C kyr BP) with the resumption of biogenic sedimentation. The Olympia Interstade is represented by an interval of hemipelagic sedimentation between ˜43 and 31.5 ka. Prior to ˜45 ka sediment deposition is controlled by glaciomarine processes with evidence for a significant IRD event at ˜47 cal kyr BP (>41±1.06 14C kyr BP).

  20. Varying responses to Indian monsoons during the past 220 kyr recorded in deep-sea sediments in inner and outer regions of the Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Isaji, Yuta; Kawahata, Hodaka; Ohkouchi, Naohiko; Ogawa, Nanako O.; Murayama, Masafumi; Inoue, Kazuki; Tamaki, Kensaku

    2015-11-01

    Although the climate in the Arabian Sea is controlled primarily by the southwest monsoon, the southwest monsoon has little influence in the Gulf of Aden. To examine the different responses to monsoons between the Gulf of Aden and areas outside the gulf, a comprehensive data set of bulk organic and inorganic geochemistry, sea surface temperature, and δ15N of pheopigments was obtained from deep-sea sediment cores recovered from inner and outer regions of the gulf. The results indicated that during the past 220 kyr, the influence of the southwest monsoon was stronger in the outer region of the gulf than in the inner region, which implies that the southwest monsoon trajectory has not changed substantially during that time period. Furthermore, influxes of O2-depleted water from the Southern Ocean and the lateral advection of upwelled seawater also had limited influence in the inner region. In contrast, concentrations of lithogenic materials transported by the southwest monsoon were similar in the two regions. δ15N of pheopigments indicated that during the last glacial maximum, the southwest monsoon was weaker and the northeast monsoon was stronger than at present. A stronger southwest monsoon during interglacials enhanced primary productivity and may have caused anoxic conditions to develop in the Arabian Sea, as indicated by redox proxies in the outer region. Anoxic conditions also formed during MIS 3, but no increase in the primary productivity is indicated; therefore, another mechanism, such as an influx of O2-depleted water from the Southern Ocean, may have been the cause.

  1. Roosevelt Island Climate Evolution Project (RICE): A 65 Kyr ice core record of black carbon aerosol deposition to the Ross Ice Shelf, West Antarctica.

    NASA Astrophysics Data System (ADS)

    Edwards, Ross; Bertler, Nancy; Tuohy, Andrea; Neff, Peter; Proemse, Bernedette; Feiteng, Wang; Goodwin, Ian; Hogan, Chad

    2015-04-01

    Emitted by fires, black carbon aerosols (rBC) perturb the atmosphere's physical and chemical properties and are climatically active. Sedimentary charcoal and other paleo-fire records suggest that rBC emissions have varied significantly in the past due to human activity and climate variability. However, few paleo rBC records exist to constrain reconstructions of the past rBC atmospheric distribution and its climate interaction. As part of the international Roosevelt Island Climate Evolution (RICE) project, we have developed an Antarctic rBC ice core record spanning the past ~65 Kyr. The RICE deep ice core was drilled from the Roosevelt Island ice dome in West Antarctica from 2011 to 2013. The high depth resolution (~ 1 cm) record was developed using a single particle intracavity laser-induced incandescence soot photometer (SP2) coupled to an ice core melter system. The rBC record displays sub-annual variability consistent with both austral dry-season and summer biomass burning. The record exhibits significant decadal to millennial-scale variability consistent with known changes in climate. Glacial rBC concentrations were much lower than Holocene concentrations with the exception of several periods of abrupt increases in rBC. The transition from glacial to interglacial rBC concentrations occurred over a much longer time relative to other ice core climate proxies such as water isotopes and suggests . The protracted increase in rBC during the transition may reflected Southern hemisphere ecosystem / fire regime changes in response to hydroclimate and human activity.

  2. Phytoliths Used to Investigate the Effects of the Indonesian Mount Toba Super-Eruption (~75 kyr) in East Africa: A Subdecadal Record from Lake Malawi

    NASA Astrophysics Data System (ADS)

    Yost, C. L.; Cohen, A. S.

    2014-12-01

    The recent discovery of cryptotephra visually and chemically matched to the Youngest Toba Tuff (YTT, 75.0 ± 0.9 kyr) in Lake Malawi drill core sediments has spurred renewed interest in this period of time in East Africa. The YTT is the most recent and largest of the four Mount Toba eruptions, and is the only super-eruption to have taken place during the Quaternary. The timing of the YTT approximately coincides with a hypothesized human genetic bottleneck. Several climate models have proposed an episode of global cooling following the YTT; however, the magnitude and duration of the cooling is much debated, ranging from just a few degrees of cooling to a state of volcanic winter. Cored sediments from Lake Malawi provide an excellent record of local variability in the lake's watershed that may be linked to specific climatic events. To investigate the possible effects of the YTT in East Africa, we continuously sampled Lake Malawi drill core 2A-10H-2 at 2-4 mm (~6 yr) intervals above and below the first occurrence of the YTT. Poaceae phytoliths were grouped into plant functional types (C3, C4, xerophytic, mesophytic, arboreal, etc.), revealing mostly subtle changes in terrestrial vegetation over the ~400 yr time period examined. Abrupt increases in concentration values for phytoliths derived from riverine Podostemaceae plants appear to signal increased discharge from rivers draining the surrounding uplands. Perhaps most significant is the increasing trend in burned phytoliths and decreasing trend in tree phytoliths post-YTT. Although there appears to be a very weak cooling signal synchronous with the YTT, the most abrupt terrestrial vegetation changes appear to be better correlated with the deposition of a slightly older cryptotephra horizon derived from the local Rungwe Volcanic Province. A potential complication with this record is the existence of a turbidite pre-YTT that encompasses the Rungwe horizon.

  3. Short-term fluctuations in vegetation and phytoplankton during the Middle Eocene greenhouse climate: a 640-kyr record from the Messel oil shale (Germany)

    NASA Astrophysics Data System (ADS)

    Lenz, Olaf K.; Wilde, Volker; Riegel, Walter

    2011-11-01

    The Palaeogene was the most recent greenhouse period on Earth. Especially for the Late Palaeocene and Early Eocene, several superimposed short-term hyperthermal events have been described, including extremes such as the Palaeocene-Eocene Thermal Maximum. Major faunal and floral turnovers in the marine and terrestrial realms were recorded in association with these events. High-resolution palynological analysis of the early Middle Eocene maar lake sediments at Messel, near Darmstadt, Germany, provides an insight into the dynamics of a climax vegetation during the Middle Eocene greenhouse climate in a time span without significant climatic excursions. Numerical techniques like detrended correspondence analysis and wavelet analysis have been applied to recognize cyclic fluctuations and long-term trends in the vegetation through a time interval of approximately 640 kyr. Based on the numerical zoning of the pollen diagram, three phases in the development of the vegetation may be distinguished. Throughout these phases, the climax vegetation did not change substantially in qualitative composition, but a trend towards noticeably less humid conditions probably in combination with a drop of the water level in the lake may be recognized. A shift in algal population from the freshwater dinoflagellate cyst Messelodinium thielepfeifferae to a dominance of Botryococcus in the uppermost part of the core is interpreted as a response to changes in acidity and nutrient availability within the lake. Time series analyses of pollen assemblages show that variations in the Milankovitch range of eccentricity, obliquity and precession can be distinguished. In addition, fluctuations in the sub-Milankovitch range are indicated. This demonstrates that floral changes during steady depositional conditions in the Middle Eocene of Messel were controlled by orbital forcing.

  4. A ~600 kyr duration Early Pleistocene record from the West Turkana (Kenya) HSPDP drill site: elemental XRF variability to reconstruct climate change in Turkana Boy's backyard

    NASA Astrophysics Data System (ADS)

    Stockhecke, M.; Beck, C. C.; Brown, E. T.; Cohen, A.; Deino, A. L.; Feibel, C. S.; Sier, M.

    2015-12-01

    . In addition, the XRF record of the changing hydroclimate of the West Turkana Basin from 1.3 to 1.9 kyrs will be explored in relation to regional reconstructions and marine stratigraphies.

  5. Decade to centennial resolution hydrogen isotopic record of climate change from southern New England for the past 16 kyr: proxy validation and multi-proxy comparisons

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Gao, L.; Hou, J.; Shuman, B. N.; Oswald, W.; Foster, D.

    2009-12-01

    Open system lakes in New England offer excellent archives of precipitation isotopic ratios that yield quantitative paleoclimate information. We have demonstrated previously from a lake sediment transect that hydrogen isotopic ratios of a middle-chain length fatty acid, behenic acid (BA), faithfully record precipitation isotopic ratios. We hypothesized that mid-chain n-alkyl lipids in these small lakes were primarily derived from aquatic plants that record lake water isotopic ratios. To test this hypothesis, we conducted systematic and extensive sampling of both terrestrial and aquatic plants over the past two years at two typical kettle hole lakes, Blood Pond and Rocky Pond, MA, and used a linear algebra approach to delineate percentage inputs of aquatic and terrestrial plant contributions to mid-chain n-alkyl lipids. Our results demonstrate that >92 % of the mid-chain n-alkyl lipids is derived from submerged and floating aquatic macrophytes. Our new data provide a solid basis for the application of behenic hydrogen isotopic ratios as a paleoclimate proxy from small lakes. We will present a decadal to centennial scale 16 kyr record of BA hydrogen isotopic ratios from Blood Pond, and will discuss the results in light of published pollen and lake level data. Overall, our hydrogen isotopic record is fully consistent with regional climate scenarios, including the distinctive warming at B-A events, abrupt cooling at YD event, and transition from glacial to Holcoene climate conditions. However, our high-solution isotopic data provides important new insights concerning abrupt regional climate variability. We demonstrate that the New England climate is exceptionally senstive to AMOC changes and solar forcing and that many of the abrupt climate fluctuations exert major impacts on terrestrial ecosystems, hydrology and lake levels.

  6. Planktic foraminiferal responses to orbital scale oceanographic changes off the western Iberian margin over the last 900 kyr: Results from IODP site U1391

    NASA Astrophysics Data System (ADS)

    Singh, A. D.; Verma, K.; Jaiswal, S.; Alonso-Garcia, M.; Li, B.; Abrantes, F.

    2015-12-01

    This paper presents planktic foraminiferal assemblage records of the last 900 kyr from the SW Iberian margin (IODP Site U1391). The faunal records show the history of surface oceanographic changes on glacial/interglacial scales before and after the Mid-Brunhes Event (MBE), a period when a major shift in the climate pattern was recorded in other regions. Temporal variations in relative abundances of characteristic species/groups are used to infer changes in the latitudinal position of the polar/Arctic water (% Neogloboquadrina pachyderma sinistral and Turborotalita quinqueloba), influence of the transitional subpolar water mass (% N. pachyderma dextral), and subtropical water (% tropical/subtropical species/group). Past changes in the upwelling intensity and productivity pattern associated with seasonal trade wind strength are inferred from the abundance variations of Globigerina bulloides and G. bulloides + Globigerinita glutinata, respectively. Faunal data reveal the influence of cold water masses (polar/subpolar) at the examined site was more pronounced during glacial stages except for marine isotope stage (MIS) 14 and 16. The magnitude of the polar/subpolar water mass invading the study area was at maximum before the MBE during MIS 18, 20 and 22, resulting in a situation like the present day Arctic Front. Interglacial periods prior to the MBE were also relatively colder than those of the post-MBE. Our faunal based inferences are in agreement with the ice-rafted debris (IRD) concentration and N. pachyderma sinistral records of the subpolar North Atlantic sites. Based on faunal proxies, we recorded major and rapid changes in upwelling intensity and related productivity during glacial Terminations. Both the upwelling intensity and productivity significantly increased after the MBE, particularly during the interglacials MIS 7, 9 and 11. Our productivity record parallels the EPICA CH4 record suggesting teleconnections between trade winds induced productivity and the

  7. South Asian monsoon history over the past 60 kyr recorded by radiogenic isotopes and clay mineral assemblages in the Andaman Sea

    NASA Astrophysics Data System (ADS)

    Ali, Sajid; Hathorne, Ed C.; Frank, Martin; Gebregiorgis, Daniel; Stattegger, Karl; Stumpf, Roland; Kutterolf, Steffen; Johnson, Joel E.; Giosan, Liviu

    2015-02-01

    The Late Quaternary variability of the South Asian (or Indian) monsoon has been linked with glacial-interglacial and millennial scale climatic changes but past rainfall intensity in the river catchments draining into the Andaman Sea remains poorly constrained. Here we use radiogenic Sr, Nd, and Pb isotope compositions of the detrital clay-size fraction and clay mineral assemblages obtained from sediment core NGHP Site 17 in the Andaman Sea to reconstruct the variability of the South Asian monsoon during the past 60 kyr. Over this time interval ɛNd values changed little, generally oscillating between -7.3 and -5.3 and the Pb isotope signatures are essentially invariable, which is in contrast to a record located further northeast in the Andaman Sea. This indicates that the source of the detrital clays did not change significantly during the last glacial and deglaciation suggesting the monsoon was spatially stable. The most likely source region is the Irrawaddy river catchment including the Indo-Burman Ranges with a possible minor contribution from the Andaman Islands. High smectite/(illite + chlorite) ratios (up to 14), as well as low 87Sr/86Sr ratios (0.711) for the Holocene period indicate enhanced chemical weathering and a stronger South Asian monsoon compared to marine oxygen isotope stages 2 and 3. Short, smectite-poor intervals exhibit markedly radiogenic Sr isotope compositions and document weakening of the South Asian monsoon, which may have been linked to short-term northern Atlantic climate variability on millennial time scales. This article was corrected on 18 MAR 2015. See the end of the full text for details.

  8. Rapid directional changes associated with a 6.5 kyr-long Blake geomagnetic excursion at the Blake-Bahama Outer Ridge

    NASA Astrophysics Data System (ADS)

    Bourne, Mark; Mac Niocaill, Conall; Thomas, Alex L.; Knudsen, Mads Faurschou; Henderson, Gideon M.

    2012-06-01

    Geomagnetic excursions are recognized as intrinsic features of the Earth's magnetic field. High-resolution records of field behaviour, captured in marine sedimentary cores, present an opportunity to determine the temporal and geometric character of the field during geomagnetic excursions and provide constraints on the mechanisms producing field variability. We present here the highest resolution record yet published of the Blake geomagnetic excursion (∼125 ka) measured in three cores from Ocean Drilling Program (ODP) Site 1062 on the Blake-Bahama Outer Ridge. The Blake excursion has a controversial structure and timing but these cores have a sufficiently high sedimentation rate (∼10 cm ka-1) to allow detailed reconstruction of the field behaviour at this site during the excursion. Palaeomagnetic measurements of the cores reveal rapid transitions (<500 yr) between the contemporary stable normal polarity and a completely reversed state of long duration which spans a stratigraphic interval of 0.7 m. We determine the duration of the reversed state during the Blake excursion using oxygen isotope stratigraphy, combined with 230Th excess measurements to assess variations in the sedimentation rates through the sections of interest. This provides an age and duration for the Blake excursion with greater accuracy and with constrained uncertainty. We date the directional excursion as falling between 129 and 122 ka with a duration for the deviation of 6.5±1.3 kyr. The long duration of this interval and the fully reversed field suggest the existence of a pseudo-stable, reversed dipole field component during the excursion and challenge the idea that excursions are always of short duration.

  9. HEC-RAS 5.0 Vs. TELEMAC-2D: a model comparison for flood-hazard and flood-risk estimation

    NASA Astrophysics Data System (ADS)

    Ezzahra Maatar, Fatma; Domeneghetti, Alessio; Brath, Armando

    2015-04-01

    River flooding is considered among the most frequent catastrophic events causing dramatic consequences in terms of loss of human life and economic damages. Therefore, the flood-hazard and flood-risk management appear nowadays the fundamental activities that public bodies and authorities in charge have to implement in order to reduce human and socio-economic losses. In this context, our study specifically refers to a flood event occurred on January 19, 2014, along the Secchia River (a tributary of the Po River; North Italy), with the aim of evaluating the suitability of different numerical tools for the reproduction of the flood dynamics. During this specific event a failure on the main embankment caused the overflowing of an overall volume of about 40•106 m3 within 48 hours inundating nearly 200 km² of the floodplain area. Thus, our study aims at reproducing the inundation dynamics using two different fully bi-dimensional (2D) hydrodynamic models, both based on Saint-Venant equations: Telemac-2D and HEC-RAS 5.0 (Beta version). The former (Telemac-2D) is a widely employed and well known 2D model adopting a finite-element scheme based on triangular elements, while the latter, HEC-RAS 5.0, is the first, recently released, version of a coupled 1D-2D model that enables one to simulate river and floodplains interactions through a finite-volume scheme. Taking advantage of the historical observations, we investigate the suitability of the new 1D-2D model in reproducing the flood patterns testing its performance in case of different mesh resolutions (i.e. cell dimension ranging from 50 m to 200 m) and Digital Elevation Model accuracy (i.e. DEM resolution varying from 1 m to 50 m). Models' performances are thus compared with real observations in terms of flood patterns (i.e. overall flood extent and flood dynamics) and flood-hazard indexes (such as water depth, flow velocity, impulse, etc.). Finally, we compare the accuracy of both models on the reconstruction of recorded

  10. Initial oxidation kinetics and energetics of Cu 0.5Au 0.5 (0 0 1) film investigated by in situ ultrahigh vacuum transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Zhou, Guang-Wen; Eastman, Jeffrey A.; Yang, Judith C.

    2006-06-01

    The initial oxidation behavior of Cu 0.5Au 0.5 (0 0 1) thin film was investigated by in situ ultrahigh vacuum transmission electron microscopy to model nano-oxidation of alloys with one active component and one noble component. The formation of irregular-shaped octahedron Cu 2O islands with cube-on-cube crystallographic orientation to the substrate film was observed at all temperature studied. The energetics of Cu 2O nucleation for Cu and Cu 0.5Au 0.5 oxidation was compared. Cu 0.5Au 0.5 oxidation has lower nucleation activation energy due to the reduced mismatch strain between Cu 2O and Cu 0.5Au 0.5 films. On the other hand, the reaction kinetics for Cu 0.5Au 0.5 alloy oxidation is slower due to the higher diffusion activation energy of Cu.

  11. Measurement of cross sections for the 147Sm(n, alpha)144Nd reaction at 5.0 and 6.0 MeV.

    PubMed

    Zhang, Guohui; Zhang, Jiaguo; Guo, Li'an; Wu, Hao; Chen, Jinxiang; Tang, Guoyou; Gledenov, Yu M; Sedysheva, M V; Khuukhenkhuu, G; Szalanski, P J

    2009-01-01

    Cross sections of the (147)Sm(n, alpha)(144)Nd reaction were measured at En=5.0 and 6.0MeV. A twin gridded ionization chamber was used as a charged particle detector and two large area (147)Sm(2)O(3) samples placed back to back were employed. Experiments were performed at the 4.5MV Van de Graaff accelerator of Peking University. Neutrons were produced through the D(d, n)(3)He reaction with a deuterium gas target. Absolute neutron flux was determined by a small (238)U fission chamber. Present cross-section data are compared with existing results of evaluations and measurements. PMID:18707895

  12. Fracture Test Results for 0.5, 0.7 and 0.9 Inch Thick 2324-T39 Aluminum Alloy Material

    NASA Technical Reports Server (NTRS)

    Johnston, William M.; Newman, James C., Jr. (Technical Monitor)

    2001-01-01

    A summary of experimental data is presented for a series of fracture tests and tensile tests that were conducted on a 2324-T39 aluminum alloy material. Static tensile tests were performed to determine the stress-strain response for the material. For the fracture tests three thicknesses (B = 0.5, 0.7, and 0.9-inches) and two specimen types (middle crack tension and compact tension specimens) were used. The middle crack tension specimens were 12-inches wide, and the compact tension specimens were 2, 4, and 6-inches wide. The fracture tests were conducted in the L-T orientation (crack perpendicular to the rolling direction and load parallel to the rolling direction).

  13. Radioisotope yields from 1.85-GeV protons on Mo and 1.85- and 5.0-GeV protons on Te

    SciTech Connect

    Bardayan, D.W.; Hindi, M.M.; Barghouty, A.F.

    1995-05-01

    Radioisotope yields from 1.85-GeV proton interactions in a natural isotopic composition Mo target and those from 1.85- and 5.0-GeV protons in natural Te targets were measured at Lawrence Berkeley Laboratory`s Bevatron. The radioisotope yields were determined by {gamma}-counting the targets using a 100-cm{sup 3} coaxial Ge detector following the irradiations. Cross sections were determined for the production of 31 radioactive nuclides, ranging from Z = 35, A = 74, to Z = 43, A = 97, from the Mo target and for 47 radioactive nuclides, ranging from Z = 35, A = 75, to Z = 53, A = 130 from the Te targets.

  14. Investigation of interaction hydrogen sulfide with (5,0) and (5,5) single-wall carbon nanotubes by density functional theory method

    NASA Astrophysics Data System (ADS)

    Oftadeh, Mohsen; Gholamian, Marzieh; Abdallah, Hassan Hadi

    2013-02-01

    Herein, the interaction of hydrogen sulfide with inside and outside single-wall carbon nanotube of (5,0) and (5,5) is investigated using density functional theory at B3LYP/6-31G* level of theory in the gaseous phase by Gaussian 09. The adsorption energies, thermodynamic properties, highest occupied molecular orbital, lowest unoccupied molecular orbital, energy gaps, and partial charges of the interacting atoms are also studied during two kinds of rotation of hydrogen sulfide (H2S) molecules as vertical and horizontal to the main axes of the nanotube. For these systems, the binding energy of H2S-single-wall carbon nanotubes is low and the process is thermodynamically near-simultaneous.

  15. 4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane Synthesis

    NASA Astrophysics Data System (ADS)

    Maksimowski, Paweł; Gołofit, Tomasz

    2013-07-01

    4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane (TEX) was obtained by nitrolysis of 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine reaction using a mixture of fuming nitric acid and concentrated sulfuric acid. The optimal process temperature was 54-56°C. The yield of the synthesis depends inter alia on the rate the reactants are introduced into the reaction medium and on the time of conditioning of the reaction mixture. A maximal yield of ca. 40% was achieved at the reactant addition time of 2 h and conditioning time of 2 h. None of the other nitrating mixtures examined proved superior to the conventional nitrating mixture. The product was examined by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) techniques and the results are reported.

  16. THE AKARI 2.5-5.0 μm SPECTRAL ATLAS OF TYPE-1 ACTIVE GALACTIC NUCLEI: BLACK HOLE MASS ESTIMATOR, LINE RATIO, AND HOT DUST TEMPERATURE

    SciTech Connect

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Lee, Seong-Kook; Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon; Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Takagi, Toshinobu; Oyabu, Shinki; Ohyama, Youichi E-mail: mim@astro.snu.ac.kr

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ∼1100 K and ∼220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  17. Small Molecule, NSC95397, Inhibits the CtBP1-Protein Partner Interaction and CtBP1-Mediated Transcriptional Repression.

    PubMed

    Blevins, Melanie A; Kouznetsova, Jennifer; Krueger, Aaron B; King, Rebecca; Griner, Lesley Mathews; Hu, Xin; Southall, Noel; Marugan, Juan J; Zhang, Qinghong; Ferrer, Marc; Zhao, Rui

    2015-06-01

    Carboxyl-terminal binding protein (CtBP) is a transcriptional corepressor that suppresses multiple proapoptotic and epithelial genes. CtBP is overexpressed in many human cancers, and its overexpression increases stem cell-like features, epithelial-mesenchymal transition, and cancer cell survival. Knockdown of CtBP also increases apoptosis independent of p53 in cell culture. Therefore, targeting CtBP with small molecules that disrupt its interaction with transcription factor partners may be an effective cancer therapy. To elicit its corepressing effect, CtBP binds to a conserved peptide motif in each transcription factor partner. We developed an AlphaScreen high-throughput screening assay to monitor the interaction between CtBP and E1A (which mimics the interaction between CtBP and its transcriptional partners). We screened the LOPAC library of 1280 bioactive compounds and identified NSC95397, which inhibits the CtBP-E1A interaction (IC50 = 2.9 µM). The inhibitory activity of NSC95397 was confirmed using two secondary assays and a counterscreen. NSC95397 also behaved as a weak substrate of CtBP dehydrogenase activity and did not inhibit another dehydrogenase, lactase dehydrogenase. Finally, NSC95397 was able to disrupt CtBP-mediated transcriptional repression of a target gene. These studies present a new possibility for the development of a therapeutic agent targeting tumors through disrupting the CtBP transcriptional complex. PMID:25477201

  18. Evaluation of ELISA testing for BP180 and BP230 as a diagnostic modality for bullous pemphigoid: a clinical experience.

    PubMed

    Keller, Jesse J; Kittridge, Ashley L; Debanne, Sara M; Korman, Neil J

    2016-05-01

    Bullous pemphigoid (BP) is a common autoimmune blistering disorder of the elderly. Several diagnostic modalities are available, including clinical impression, histopathology, direct and indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) detection of pathogenic antibodies. In this study, we aim to examine the utility of the newest test, ELISA, in comparison to the constellation of other tests. We describe our clinical experience in which 170 patients diagnosed with bullous pemphigoid had multiple tests performed. BP180 alone showed a sensitivity of 54 % and specificity of 94 %. The positive predictive value (PPV) is 95 % while the negative predictive value (NPV) is 52 %. BP230 alone yielded a sensitivity of 48 % and specificity of 94 %. The PPV is 94 % and the NPV is 49 %. Using both tests in combination yielded a sensitivity of 66 % and specificity of 89 %. The PPV of at least one of two tests returning positive is 92 % while the NPV of dual negative tests is 58 %. Use of ELISAs for suspected cases of BP are an inadequate standalone test, and are only helpful in making the diagnosis should they return positive. However, they would appear to miss about one-third of cases. PMID:26895534

  19. Gate tunable WSe2-BP van der Waals heterojunction devices

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Zhang, Ting Ting; Zhang, Jing; Xiang, Jianyong; Yu, Hua; Wu, Shuang; Lu, Xiaobo; Wang, Guole; Wen, Fusheng; Liu, Zhongyuan; Yang, Rong; Shi, Dongxia; Zhang, Guangyu

    2016-02-01

    Due to the weak screening effect, the concentration and type of charge carriers in 2D semiconductor heterostructures can be effectively tuned by electrostatic gating, enabling us to realize different types of heterojunctions in a single device. Such `type tunable' properties are useful for designing novel electrical or optoelectrical devices. Here, we demonstrate a `type tunable' heterojunction device construct with two pieces of ambipolar 2D semiconductors: WSe2 and black phosphorus (BP). This heterojunction could be tuned to either the p-p junction or n-n junction by gate modulation. The p-p junction shows a large current rectification ratio while the n-n junction shows a negligible current rectification ratio, indicating a large valence band offset and a small conduction band offset at the WSe2/BP interface. In the optoelectrical measurements, we found the amplitude and even the polarity of photocurrent could be modulated by electrostatic gating. Our study could further enhance the understanding of designing devices based on these `type tunable' van der Waals heterojunctions. Moreover, the properties of the WSe2/BP interface were also experimentally identified through the electrical and optoelectrical measurements in our study.Due to the weak screening effect, the concentration and type of charge carriers in 2D semiconductor heterostructures can be effectively tuned by electrostatic gating, enabling us to realize different types of heterojunctions in a single device. Such `type tunable' properties are useful for designing novel electrical or optoelectrical devices. Here, we demonstrate a `type tunable' heterojunction device construct with two pieces of ambipolar 2D semiconductors: WSe2 and black phosphorus (BP). This heterojunction could be tuned to either the p-p junction or n-n junction by gate modulation. The p-p junction shows a large current rectification ratio while the n-n junction shows a negligible current rectification ratio, indicating a large valence

  20. Calibration of the radiocarbon time scale at 37ka BP

    SciTech Connect

    Southon, J.R.; Deino, A.L.; Orsi, G.

    1995-12-01

    Results from radiocarbon and U-Th measurements on corals have provided a radiocarbon calibration beyond the range covered by tree ring series, but the uncertainties in the measurements beyond 20ka BP are very large. We have obtained new calibration data from radiocarbon dates on material associated with the catastrophic Campanian Ignimbrite eruption from the Phlegrean Fields near Naples. The eruption has been well dated by {sup 40}Ar/{sup 39}Ar to 37ka BP. Radiocarbon measurements were carried out on charcoal from a carbonized branch exposed within the ignimbrite tuff on the wall of an active quarry. The sample was split and analyzed at both the Naples and Lawrence Livermore AMS facilities. The offset between the Ar-Ar data and the radiocarbon results (recalculated using the true 5730-year half life for {sup 14}C) is consistent with predictions from paleomagnetic data and carbon cycle modeling.

  1. Spectropolarimetry of the classical T Tauri star BP Tauri

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Johns-Krull, Christopher

    2012-05-01

    We implement a least-squares deconvolution (LSD) code to study magnetic fields on cool stars. We first apply our code to high resolution (R ~ 60,000) optical echelle spectra of several solar-like stars as tests of the code and to measure the mean longitudinal magnetic field on the surface of these stars. Null results or weak fields are detected on the solar-like stars as is expected, demonstrating the functionality of the LSD code. We then apply our LSD code to 6 nights of data on the Classical T Tauri Star BP Tau. A maximum field of 330 +/- 80 G is detected from the photospheric lines on BP Tau. Measurements of several emission lines (He I 5876 A˚, Ca II 8498 A˚ and 8542 A˚) show the presence of strong magnetic fields in the line formation regions, which are believed to be the base of the accretion footpoints.

  2. Variability of Balmer Profiles in Magnetic Ap/Bp Stars

    NASA Astrophysics Data System (ADS)

    Valyavin, G.; Lee, B.-C.; Shulyak, D.; Han, I.; Kochukhov, O.; Khang, D.-I.; Kim, K.-M.

    2007-06-01

    A set of high precision measurements of weak variations of hydrogen lines in spectra of seven magnetic Ap/Bp stars was carried out using the BOES echelle spectrograph of the Bohuynsan Optical Astronomy Observatory (South Korea). A weak (1-2 %) periodic variability of the Balmer line wings has been detected in the spectra of 2 program stars. Upper limits of possible variations are presented for the remaining 5 objects. We discuss the discovered variability in the framework of model atmospheres with magnetic force terms included. The periodic changes in the Balmer profiles are caused by perturbations in atmospheres of Ap/Bp stars due to their rotationally modulated non-force-free magnetic fields.

  3. Magnetospheric accretion on the T Tauri star BP Tauri

    NASA Astrophysics Data System (ADS)

    Donati, J.-F.; Jardine, M. M.; Gregory, S. G.; Petit, P.; Paletou, F.; Bouvier, J.; Dougados, C.; Ménard, F.; Collier Cameron, A.; Harries, T. J.; Hussain, G. A. J.; Unruh, Y.; Morin, J.; Marsden, S. C.; Manset, N.; Aurière, M.; Catala, C.; Alecian, E.

    2008-05-01

    From observations collected with the ESPaDOnS and NARVAL spectropolarimeters, we report the detection of Zeeman signatures on the classical T Tauri star (cTTS) BP Tau. Circular polarization signatures in photospheric lines and in narrow emission lines tracing magnetospheric accretion are monitored throughout most of the rotation cycle of BP Tau at two different epochs in 2006. We observe that rotational modulation dominates the temporal variations of both unpolarized and circularly polarized spectral proxies tracing the photosphere and the footpoints of accretion funnels. From the complete data sets at each epoch, we reconstruct the large-scale magnetic topology and the location of accretion spots at the surface of BP Tau using tomographic imaging. We find that the field of BP Tau involves a 1.2 kG dipole and 1.6 kG octupole, both slightly tilted with respect to the rotation axis. Accretion spots coincide with the two main magnetic poles at high latitudes and overlap with dark photospheric spots; they cover about 2 per cent of the stellar surface. The strong mainly axisymmetric poloidal field of BP Tau is very reminiscent of magnetic topologies of fully convective dwarfs. It suggests that magnetic fields of fully convective cTTSs such as BP Tau are likely not fossil remants, but rather result from vigorous dynamo action operating within the bulk of their convective zones. Preliminary modelling suggests that the magnetosphere of BP Tau extends to distances of at least 4R* to ensure that accretion spots are located at high latitudes, and is not blown open close to the surface by a putative stellar wind. It apparently succeeds in coupling to the accretion disc as far out as the corotation radius, and could possibly explain the slow rotation of BP Tau. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) and at the Télescope Bernard Lyot (TBL). CFHT is operated by the National Research Council of Canada, the Institut National des Sciences de l

  4. Diffusion and Settling in Ap/Bp Stars

    SciTech Connect

    Turcotte, S

    2003-04-09

    Ap/Bp stars are magnetic chemically peculiar early A and late B type stars of the main sequence. They exhibit peculiar surface abundance anomalies that are thought to be the result of gravitational settling and radiative levitation. The physics of diffusion in these stars are reviewed briefly and some model predictions are discussed. While models reproduce some observations reasonably well, more work is needed before the behavior of diffusing elements in a complex magnetic field is fully understood.

  5. Gate tunable WSe2-BP van der Waals heterojunction devices.

    PubMed

    Chen, Peng; Zhang, Ting Ting; zhang, Jing; Xiang, Jianyong; Yu, Hua; Wu, Shuang; Lu, Xiaobo; Wang, Guole; Wen, Fusheng; Liu, Zhongyuan; Yang, Rong; Shi, Dongxia; Zhang, Guangyu

    2016-02-14

    Due to the weak screening effect, the concentration and type of charge carriers in 2D semiconductor heterostructures can be effectively tuned by electrostatic gating, enabling us to realize different types of heterojunctions in a single device. Such 'type tunable' properties are useful for designing novel electrical or optoelectrical devices. Here, we demonstrate a 'type tunable' heterojunction device construct with two pieces of ambipolar 2D semiconductors: WSe2 and black phosphorus (BP). This heterojunction could be tuned to either the p-p junction or n-n junction by gate modulation. The p-p junction shows a large current rectification ratio while the n-n junction shows a negligible current rectification ratio, indicating a large valence band offset and a small conduction band offset at the WSe2/BP interface. In the optoelectrical measurements, we found the amplitude and even the polarity of photocurrent could be modulated by electrostatic gating. Our study could further enhance the understanding of designing devices based on these 'type tunable' van der Waals heterojunctions. Moreover, the properties of the WSe2/BP interface were also experimentally identified through the electrical and optoelectrical measurements in our study. PMID:26810387

  6. The Arctic Ocean in response to millennial time scale paleoceanographic changes during the last glaciation, 70-25 years BP

    NASA Astrophysics Data System (ADS)

    Rasmussen, Tine L.; Thomsen, Erik; Nielsen, Tove

    2014-05-01

    The climate and paleoceanography of the last Glaciation were deeply affected by up to 25 abrupt temperature fluctuations generally known as Dansgaard-Oeschgwer events. The events have been documented worldwide, but the strongest and most abrupt fluctuations have been recorded from the Nord Atlantic and Nordic Seas indicating that their origin should be sought in this region. The events are generally linked to changes in deep water formation in the Nordic Seas and North Atlantic, disrupting the thermohaline circulation. Nevertheless, Dansgaard-Oeschger events have so far not been recorded north of the convection areas in the central Nordic Seas, and it is not known if they influenced the water exchange through the Fram Strait and thus affected the Arctic Ocean. We have studied gravity core JM05-31GC from the eastern Fram Strait at 80°N (785 m water depth) to reconstruct paleoceanographic changes in relation to the rapid climate changes of the Dansgaard-Oeschger (DO) events during marine isotope stages 4-2 (70-20 kyr BP). The core site is located within the path of the north flowing Atlantic Water at the very entrance to the Arctic Ocean. The results show millennial time scale changes in subsurface and bottom water temperatures, in the distribution of planktonic and benthic foraminifera in sediment grain size, in the content of ice rafted debris (IRD), and in the stable isotope values. In JM05-31GC, the interstadials are characterized by relatively high surface and low bottom water temperatures, low content of IRD and well-ventilated bottom water. Stadials are characterized by presence of icebergs, decreasing surface water and increasing bottom water temperatures. Ventilation decreased during Heinrich events and most stadials. The results show that the Dansgaard-Oeschger events strongly affected the water exchange between the Nordic Seas and the Arctic Ocean. The exchange of subsurface and intermediate water was similar to today during interstadials with strong flow

  7. High resolution multi-proxy records of the last 60 kyr in the Southeastern Carpathian basin: towards a palaeoclimatic reconstruction from NW to SE Europe

    NASA Astrophysics Data System (ADS)

    Marković, Slobodan; Stevens, Thomas; Hambach, Ulrich; Machalett, Björn; Bokhorst, Mark; Vandenberghe, Jef; Svirčev, Zorica; Zöller, Ludwig

    2010-05-01

    preliminary tephrochronological results indicate possibilities independent correlation with the other continental and marine records. At an interface between Mediterranean, Atlantic and Continental climate, the results presented in this study emphasise the importance of understanding the mechanisms behind last glacial climate change recorded in the Vojvodina loess-palaeosol sequences, as a contribution toward a more detailed spatial and temporal reconstruction of environmental dynamics across the European continent during the last 60 kyr.

  8. Co-located monogenetic eruptions ~200 kyr apart driven by tapping vertically separated mantle source regions, Chagwido, Jeju Island, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Brenna, Marco; Németh, Károly; Cronin, Shane J.; Sohn, Young Kwan; Smith, Ian E. M.; Wijbrans, Jan

    2015-05-01

    -developed paleosol represents at least 200 kyr between the two co-located eruptions. The distinctive magma compositions show that each eruption tapped an independent region within the same underlying mantle source. These observations show that contrary to most assumptions of monogenetic volcanism, an already "tapped" source region may become fertile again through mantle convection/migration and eruptions can thus be expected from old vent sites in long-lived volcanic fields.

  9. The Emsian - Eifelian (Lower - Middle Devonian) boundary occurs in a 100-kyr eccentricity maximum: A potentially useful secondary marker for the GSSP section (Wetteldorf Richtschnitt, Germany).

    NASA Astrophysics Data System (ADS)

    De Vleeschouwer, D.; Makarona, C.; Linnemann, U.; Königshof, P.; Claeys, P. F.

    2015-12-01

    . We observe a mixed forcing of obliquity and eccentricity-modulated precession. Moreover, the Emsian - Eifelian boundary clearly occurs shortly after a 100-kyr eccentricity maximum. This cyclostratigraphic observation can be used as an additional mean in future long-distance correlations between Emsian - Eifelian boundary sections.

  10. Stability of rift axis magma reservoirs: Spatial and temporal evolution of magma supply in the Dabbahu rift segment (Afar, Ethiopia) over the past 30 kyr

    NASA Astrophysics Data System (ADS)

    Medynski, S.; Pik, R.; Burnard, P.; Vye-Brown, C.; France, L.; Schimmelpfennig, I.; Whaler, K.; Johnson, N.; Benedetti, L.; Ayelew, D.; Yirgu, G.

    2015-01-01

    Unravelling the volcanic history of the Dabbahu/Manda Hararo rift segment in the Afar depression (Ethiopia) using a combination of cosmogenic (36Cl and 3He) surface exposure dating of basaltic lava-flows, field observations, geological mapping and geochemistry, we show in this paper that magmatic activity in this rift segment alternates between two distinct magma chambers. Recent activity in the Dabbahu rift (notably the 2005-2010 dyking crises) has been fed by a seismically well-identified magma reservoir within the rift axis, and we show here that this magma body has been active over the last 30 kyr. However, in addition to this axial magma reservoir, we highlight in this paper the importance of a second, distinct magma reservoir, located 15 km west of the current axis, which has been the principal focus of magma accumulation from 15 ka to the subrecent. Magma supply to the axial reservoir substantially decreased between 20 ka and the present day, while the flank reservoir appears to have been regularly supplied with magma since 15 ka ago, resulting in less variably differentiated lavas. The trace element characteristics of magmas from both reservoirs were generated by variable degrees of partial melting of a single homogeneous mantle source, but their respective magmas evolved separately in distinct crustal plumbing systems. Magmatism in the Dabbahu/Manda Hararo rift segment is not focussed within the current axial depression but instead is spread out over at least 15 km on the western flank. This is consistent with magneto-telluric observations which show that two magma bodies are present below the segment, with the main accumulation of magma currently located below the western flank, precisely where the most voluminous recent (<15 ka) flank volcanism is observed at the surface. Applying these observations to slow spreading mid-ocean ridges indicates that magma bodies likely have a lifetime of a least 20 ka, and that the continuity of magmatic activity is

  11. Clay mineral contribution from various provenances in the northern South China Sea over the past 400 kyr: implications for the East Asian monsoon evolution

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Xie, Xin; Kissel, Catherine

    2014-05-01

    Clay mineralogy of Core MD12-3432 taken at 2125 m water depth (CIRCEA cruise on board the R.V. Marion Dufresne, IPEV) in the northern South China Sea was investigated in order to understand the time series contribution of terrigenous sediments from various provenances. With calibration of a low-resolution analysis on carbonate concentration and major elements, we converted the XRF core scanned calcium data into a high-resolution carbonate content records. Through referring to the well-dated carbonate record of nearby Core MD05-2904, we established a reliable age model, indicating about 400 kyr ago at the bottom of Core MD12-3432. The clay mineral assemblage is dominated by smectite (23-59%) and illite (22-43%), with minor chlorite (13-27%) and kaolinite (4-13%). The time series variation of clay mineral assemblages indicates strong glacial-interglacial cyclicity. In general, the variation in smectite content is similar to that of carbonate concentration, with higher values during interglacials than during glacials, while illite and chlorite contents showing opposite patterns. The change in kaolinite content shows an independent pattern with high values during glacials, corresponding well with the illite crystallinity variation. The provenance analysis of these clay minerals suggests three end-member sources: all smectites derive from Luzon, all kaolinites originate from the Pearl River, and illite and chlorite are coming from both the Pearl River and Taiwan. Using the linear separation method of illite crystallinity, a time series of the clay mineral contribution from the three major provenances to the northern South China Sea was reconstructed. Combined with spectral analyses, we suggest the clay mineral contribution from Pearl River was mainly influenced by sea level change, while the East Asian summer monsoon controlled the contribution from Luzon. The strong precipitation rate related to intensive East Asian summer monsoon would have enhanced the denudation and

  12. A 400-kyr record of millennial-scale carbonate preservation events in the Southern Ocean: Implications for Atlantic Meridional Overturning Circulation and atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Hodell, D. A.; Vautravers, M. J.; Barker, S.; Charles, C.; Crowhurst, S.

    2014-12-01

    Hodell et al. (2001) suggested that carbonate preservation in the deep Cape Basin represented a qualitative, high-resolution record of the temporal evolution of the carbonate saturation state of the deep sea. The carbonate signal reflects both transient events in the redistribution of alkalinity and DIC in the deep ocean and steady-state mass balance processes. Here we re-analyzed the carbonate records of Sites 1089/TN057-21 using an Avaatech XRF core scanner and measured elemental variations at 2.5-mm resolution for the past 400 kyrs. Log Ca/Ti is highly correlated to weight percent carbonate content and other dissolution proxies and resolves millennial-scale events in carbonate preservation. A high-pass filter removes the low-frequency (orbital) variability in carbonate preservation, which is attributed mainly to steady-state mass balance processes. The high-frequency (suborbital) component reflects transient responses to the redistribution of carbonate ion that is related mainly to changing deep-water circulation. During the last glacial period, distinct millennial-scale increases in carbonate preservation in piston core TN057-21 occurred during times of enhanced Atlantic Meridional Overtunring Circulation (AMOC) (Barker et al., 2010; Barker and Diz, 2014), as supported by increases in benthic δ13C and less radiogenic ɛNd values. Carbonate preservation peaked particularly during long, warm interstadials in Greenland when a deep water mass with high carbonate ion concentration was formed in the North Atlantic. Export of NADW may have been greater than the Holocene during some of these events ("overshoots") and/or preformed carbonate ion concentrations in North Atlantic source areas may have been higher owing to lower atmospheric CO2 and less carbonate production in surface water. Each South Atlantic carbonate peak is associated with the start of Antarctic cooling and declining or leveling of atmospheric CO2, reflecting the signature of a thermal bipolar seesaw

  13. Gum arabic and Fe²⁺ synergistically improve the heat and acid stability of norbixin at pH 3.0-5.0.

    PubMed

    Guan, Yongguang; Zhong, Qixin

    2014-12-31

    Thermal and acid stabilities of norbixin are challenges for its application as a food colorant. In this work, gum arabic and Fe(2+) were studied for the possibility to improve the thermal and acid stabilities of norbixin. Norbixin was dissolved at 0.004% w/v in deionized water with and without 0.2% w/v gum arabic and/or 0.15 mM ferrous chloride, adjusted to pH 3.0-5.0, and heated at 90 or 126 °C for 30 min. Before heating, norbixin precipitated at pH 3.0-4.0, which was prevented by gum arabic. The thermal stability of norbixin was improved by the combination of gum arabic and Fe(2+). Fluorescence analyses indicated the complex formation between norbixin and gum arabic with and without Fe(2+). Particle size and atomic force microscopy results suggested Fe(2+) and gum arabic synergistically prevented the aggregation of norbixin at acidic pH and during heating. It was hypothesized that the core of gum arabic-norbixin complexes was strengthened by Fe(2+) to enable the synergy. PMID:25479179

  14. Cross sections of the {sup 67}Zn(n,{alpha}){sup 64}Ni reaction at 4.0, 5.0, and 6.0 MeV

    SciTech Connect

    Zhang Guohui; Liu Jiaming; Wu Hao; Liu Xiang; Chen Jinxiang; Gledenov, Yu. M.; Sedysheva, M. V.; Stolupin, V. A.; Khuukhenkhuu, G.; Szalanski, P. J.

    2010-11-15

    Experimental cross section data of the {sup 67}Zn(n,{alpha}){sup 64}Ni reaction are very scanty because the residual nucleus {sup 64}Ni is stable and the commonly used activation method is not feasible. As a result, very large deviations (about 10 times) exist among different nuclear data libraries. In the present work, cross sections of the partial {sup 67}Zn(n,{alpha}{sub 0}){sup 64}Ni and total {sup 67}Zn(n,{alpha}){sup 64}Ni reactions are measured at neutron energies of 4.0 and 5.0 MeV for the first time, and those of 6.0 MeV are remeasured for consistency checking. A twin-gridded ionization chamber was used as the charged-particle detector and two enriched back-to-back-set {sup 67}Zn samples were adopted. Experiments were performed at the 4.5 MV Van de Graaff Accelerator of Peking University. Neutrons were produced through the {sup 2}H(d,n){sup 3}He reaction using a deuterium gas target. Absolute neutron flux was determined by counting the fission fragments from a {sup 238}U sample placed inside the gridded ionization chamber while a BF{sub 3} long counter was employed as neutron flux monitor. Present data are compared with results of previous measurements, evaluations, and talys code calculations.

  15. The GEOS-5 Data Assimilation System-Documentation of Versions 5.0.1, 5.1.0, and 5.2.0

    NASA Technical Reports Server (NTRS)

    Suarez, Max J.; Rienecker, M. M.; Todling, R.; Bacmeister, J.; Takacs, L.; Liu, H. C.; Gu, W.; Sienkiewicz, M.; Koster, R. D.; Gelaro, R.; Stajner, I.; Nielsen, J. E.

    2008-01-01

    This report documents the GEOS-5 global atmospheric model and data assimilation system (DAS), including the versions 5.0.1, 5.1.0, and 5.2.0, which have been implemented in products distributed for use by various NASA instrument team algorithms and ultimately for the Modem Era Retrospective analysis for Research and Applications (MERRA). The DAS is the integration of the GEOS-5 atmospheric model with the Gridpoint Statistical Interpolation (GSI) Analysis, a joint analysis system developed by the NOAA/National Centers for Environmental Prediction and the NASA/Global Modeling and Assimilation Office. The primary performance drivers for the GEOS DAS are temperature and moisture fields suitable for the EOS instrument teams, wind fields for the transport studies of the stratospheric and tropospheric chemistry communities, and climate-quality analyses to support studies of the hydrological cycle through MERRA. The GEOS-5 atmospheric model has been approved for open source release and is available from: http://opensource.gsfc.nasa.gov/projects/GEOS-5/GEOS-5.php.

  16. Thermodynamic properties of underdoped YBa2Cu3O6+x cuprates for doping values x ∈ (0 . 5 , 0 . 9)

    NASA Astrophysics Data System (ADS)

    Salas, P.; Solis, M. A.; Fortes, M.

    We extend the Boson-Fermion superconductivity model to include layered systems, such as underdoped cuprate superconductors YBa2Cu3O6+x, with x ∈ (0 . 5 , 0 . 9) ranging from underdoped to optimally doped. We model cuprates as a boson-fermion quantum gas mixture immersed in a layered structure, generated via a Dirac comb potential applied in one direction while the particles move freely in the other two directions. The optimum parameters of the system, which are the impenetrability of the planes and the paired fermion fraction, are obtained by minimizing the Helmholtz free energy and setting the experimental critical temperature Tc. Using this optimized scheme, we are able to predict the following thermodynamic properties of cuprates as a function of temperature: the entropy; the Helmholtz free energy; the electronic specific heat and the total specific heat for different doping values. Furthermore, we determinate the behavior of the jump height in the electronic specific heat, the normal electronic specific heat coefficient γ (Tc) , the quadratic α and cubic β terms of the specific heat for low temperatures, the ground state energy and the mass anisotropy as a function of doping. Comparison to experimental values reported is analyzed. We aknowledge the support from Grants UNAM-DGAPA-PAPIIT IN-111613 and CONACYT 221030, Mexico.

  17. Cross Section Measurement for the 95Mo(n, {alpha})92Zr Reaction at 4.0, 5.0 and 6.0 MeV

    SciTech Connect

    Zhang, Guohui; Wu, Hao; Zhang, Jiaguo; Liu, Jiaming; Yin, Yuxiang; Chen, Jinxiang; Gledenov, Youri Mikhailovich; Sedysheva, M. V.; Khuukhenkhuu, G; Koehler, Paul Edward; Szalanski, P.

    2011-01-01

    For the {sup 95}Mo(n, {alpha}){sup 92}Zr reaction cross section, there is only one experimental datum in the MeV neutron energy region with large uncertainty. As a result, very large deviations exist in different evaluated nuclear data libraries. This paper report the measurement of cross sections of the {sup 95}Mo(n, {alpha}){sup 92}Zr reaction at En = 4.0, 5.0 and 6.0 MeV. Experiments were performed at the 4.5 MV Van de Graaff of Peking University, China. A twin gridded ionization chamber was used as alpha particle detector and two large area {sup 95}Mo samples placed back to back were adopted. Fast neutrons were produced through the D(d, n){sup 3}He reaction by using a deuterium gas target. A small {sup 238}U fission chamber was adopted for absolute neutron flux determination and a BF{sub 3} long counter was used for neutron flux monitor. Present experimental data are compared with existing evaluations and measurement.

  18. A 70,000 year multiproxy record of climatic and environmental change from Rano Aroi peatland (Easter Island)

    NASA Astrophysics Data System (ADS)

    Margalef, Olga; Cañellas-Boltà, Núria; Pla-Rabes, Sergi; Giralt, Santiago; Pueyo, Juan Jose; Joosten, Hans; Rull, Valentí; Buchaca, Teresa; Hernández, Armand; Valero-Garcés, Blas L.; Moreno, Ana; Sáez, Alberto

    2013-09-01

    The Rano Aroi mire on Easter Island (also known as Rapa Nui; 27°09‧S, 109°27‧W, 430 m above sea level) provides a unique non-marine record in the central South Pacific Ocean for reconstructing Late Pleistocene environmental changes. The results of a multiproxy study on two cores from the center and margin of the Rano Aroi mire, including peat stratigraphy, facies analysis, elemental and isotope geochemistry on bulk organic matter, X-ray fluorescence (XRF) core scanning and macrofossil analysis, were used to infer past water levels and vegetation changes. The chronology was based on 18 14C AMS dates for the upper 8.7 m. The extrapolated age for the base of the sequence is 70 kyr, which implies that this record is the oldest paleolimnological record on Easter Island. The recovered Rano Aroi sequence consists of a radicel peat formed primarily from the remains of sedges, grasses and Polygonaceae that have accumulated since Marine Isotopic Stage (MIS) 4 (70 kyr BP) to the present. From 60 to 40 kyr BP (MIS 3), high precipitation/runoff events were recorded as organic mud facies with lighter δ13C, low C/N values and high Ti content, indicating higher detritic input to the mire. A gradual shift in δ13C bulk organic matter from - 14% to - 26%, recorded between 50 and 45 cal kyr BP, suggests a progressive change in local peat-forming vegetation from C4 to C3 plant types. Post-depositional Ca and Fe enrichment during sub-aerial peat exposure and very low sedimentation rates indicate lower water tables during Late MIS 3 (39-31 cal kyr BP). During MIS 2 (27.8-19 cal kyr BP), peat production rates were very low, most likely due to cold temperatures, as reconstructed from other Easter Island records during the Last Glacial Maximum (LGM). Geochemical and macrofossil evidence shows that peat accumulation reactivates at approximately 17.5 cal kyr BP, reaching the highest accumulation rates at 14 cal kyr BP. Peat accretion decreased from 5.0 to 2.5 cal kyr BP, coinciding

  19. Reproduction of influence of autumn snow cover anomalies on the following winter atmospheric dynamics in INMCM4.0 and INMCM5.0 data

    NASA Astrophysics Data System (ADS)

    Martynova, Yuliya

    2015-04-01

    There are different studies of the influence of autumn snow cover anomalies on atmospheric dynamics in the following winter (e.g. Allen R.J. and Zender C.S., 2011; Martynova Yu.V. and Krupchatnikov V.N., 2010). The mechanism of this effect is complex and largely affects stratospheric processes (Cohen J. et al., 2007). The snow cover rapidly increases exceeding normal values. Emerged diabatic cooling results in pressure increase over and temperature decrease under the normal value. Thus, in troposphere upward energy flux increases, and then it is absorbed in stratosphere. Strong convergence of wave activity flux causes geopotential heights increase, polar vortex slowdown and stratospheric temperature increase. Emerged geopotential and wind anomalies extend from stratosphere to troposphere up to surface. As a result, strong negative AO mode appears near the surface as surface air temperature increase. Siberia plays important role in this mechanism. Firstly, the most extensive snow cover is formed there. Secondly, according to NOAA satellite observations this cover is generally formed in October (Gong G. Et al., 2003). As a result, Siberia is very interesting for investigations of the autumn snow cover anomalies influence on the atmospheric dynamics in the following winter. This study is devoted to detection and estimation of described mechanism in INMCM4.0 and INMCM5.0 data. INMCM5.0 model represents further development of INMCM4.0 model (Volodin E.M. et al., 2010; Volodin E.M., 2014). They are different both from physical (various physical processes) and numerical (spatial resolution) points of view, thus giving different results representing various physical processes. An analysis of some parameters of atmospheric dynamics shows that top of atmosphere and vertical resolution set in INMCM models play important role in reproduction of influence of the Siberian autumn snow cover anomalies on the Northern Hemisphere atmospheric dynamics in the following winter

  20. The Role of Multiple Foreshock Structures in Facilitating the Rupture of the Mw 5.0 Earthquake Swarm Mainshock near Urban Reno, Nevada in 2008

    NASA Astrophysics Data System (ADS)

    Ruhl, C. J.; Smith, K. D.; Abercrombie, R. E.

    2014-12-01

    We resolve complex spatial and temporal evolution of a long-duration earthquake sequence on multiple fault planes by combining high-precision relative relocations with over 350 first-motion focal mechanisms and applying physics-based, open-source software supported by both the USGS and CIG (Computational Infrastructure in Geodynamics) to investigate static and quasi-static stress changes during an 8 week foreshock period. Low-magnitude earthquake activity began on February 28, 2008 in the Mogul neighborhood west of urban Reno, NV and continued to build in intensity leading to the MW 5.0 mainshock on April 26, 2008. Initial locations are obtained by applying station and datum corrections to analyst-picked travel times using HYPOINVERSE then relocating the sequence via the HypoDD double-difference algorithm of Waldhauser and Ellsworth (2000) using both cross-correlated and catalog phase data on P and S arrivals. The final relocation set reveals a mechanism-supported temporal and spatial migration of seismicity on several distinct structures prior to the mainshock rupture. First-motion focal mechanisms are computed using the HASH code of Hardebeck and Shearer (2002). We apply the spatial and temporal stress inversion (SATSI) software (Hardebeck and Michael, 2006) to investigate variations in the stress field throughout the sequence. We integrate preliminary analysis of stress drops (ML ≥ 3.0) using an EGF-derived spectral ratio technique. Finally, we determine significant fault planes identified in the foreshock sequence and build a local 3D fault model. We systematically test various slip scenarios on these structures using both CIG's finite-element crustal deformation code PyLith and the USGS-supported Coulomb 3 program to explore how the foreshocks promote or inhibit failure on subsequent structures that may facilitate mainshock rupture.

  1. Optical study of narrow band gap InAsxSb1 -x (x =0 , 0.25, 0.5, 0.75, 1) alloys

    NASA Astrophysics Data System (ADS)

    Namjoo, Shirin; Rozatian, Amir S. H.; Jabbari, Iraj; Puschnig, Peter

    2015-05-01

    The structural, electronic, and optical properties of InAs, InSb, and their ternary alloys InAsxSb1 -x (x =0.25 , 0.5, 0.75) are investigated within density functional theory utilizing the wien2k package. We find that the lattice constants and bulk moduli as a function of x are in best agreement with Vegard's linear rule. When computing the electronic band structures with the modified Becke-Johnson exchange-correlation functional (mBJLDA), our results for the band gaps of InAs, InSb, and their ternary alloys are in good agreement with the available experimental results while the conventional Wu-Cohen generalized gradient approximation (GGA) functional leads to zero or close to zero band gaps. In particular, our mBJLDA results confirm experimental evidence that the minimum band gap occurs for As concentrations around x ≈0.3 . Furthermore, we investigate the dielectric function of these compounds within the random phase approximation using both the Wu-Cohen GGA and the mBJLDA functionals. While the mBJLDA results of our fully first-principles calculations show good agreement of the peak positions in ɛ2(ω ) with experiments, the peaks in the optical spectra based on the Wu-Cohen GGA band structure appear redshifted compared to experiment. We further identify the interband transitions responsible for the structures in the spectra. Looking at the optical matrix element, we note that the major peaks are dominated by transition from the Sb 5 p (As 4 p ) states to In s states for InSb and InAs0.25Sb0.75 (InAs, InAs0.75Sb0.25 , and InAs0.5Sb0.5 ).

  2. AKARI observations of brown dwarfs. IV. Effect of elemental abundances on near-infrared spectra between 1.0 and 5.0 μm

    SciTech Connect

    Sorahana, S.; Yamamura, I.

    2014-09-20

    The detection of the CO{sub 2} absorption band at 4.2 μm in brown dwarf spectra by AKARI has made it possible to discuss CO{sub 2} molecular abundance in brown dwarf atmospheres. In our previous studies, we found an excess in the 4.2 μm CO{sub 2} absorption band of three brown dwarf spectra, and suggested that these deviations were caused by high C and O elemental abundances in their atmospheres. To validate this hypothesis, we have constructed a set of models of brown dwarf atmospheres with various elemental abundance patterns, and we investigate the variations of the molecular composition and the thermal structure, and how they affect the near-infrared spectra between 1.0 and 5.0 μm. The 4.2 μm CO{sub 2} absorption band in some late-L and T dwarfs taken by AKARI is stronger or weaker than predicted by corresponding models with solar abundance. By comparing the CO{sub 2} band in the model spectra to the observed near-infrared spectra, we confirm possible elemental abundance variations among brown dwarfs. We find that the band strength is especially sensitive to O abundance, but C is also needed to reproduce the entire near-infrared spectra. This result indicates that both the C and O abundances should increase and decrease simultaneously for brown dwarfs. We find that a weaker CO{sub 2} absorption band in a spectrum can also be explained by a model with lower 'C and O' abundances.

  3. ITS version 5.0 :the integrated TIGER series of coupled electron/Photon monte carlo transport codes with CAD geometry.

    SciTech Connect

    Franke, Brian Claude; Kensek, Ronald Patrick; Laub, Thomas William

    2005-09-01

    ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of linear time-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2) multigroup codes with adjoint transport capabilities, (3) parallel implementations of all ITS codes, (4) a general purpose geometry engine for linking with CAD or other geometry formats, and (5) the Cholla facet geometry library. Moreover, the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

  4. Heritability of HR and BP Response To Exercise Training in the HERITAGE Family Study.

    ERIC Educational Resources Information Center

    Rice, Treva; Gagnon, Jacques; Leon, Arthur S.; Skinner, James S.; Wilmore, Jack H.; Bouchard, Claude; Rao, D. C.

    2002-01-01

    Assessed the heritability of response to exercise training in resting blood pressure (BP) and heart rate (HR) among sedentary Caucasians comprising 98 families who completed an exercise training program. Results indicated that the trainability of systolic BP and HR in families with elevated BP was partially determined by genetic factors. Diastolic…

  5. Levels of the E2 interacting protein TopBP1 modulate papillomavirus maintenance stage replication

    SciTech Connect

    Kanginakudru, Sriramana; DeSmet, Marsha; Thomas, Yanique; Morgan, Iain M.; Androphy, Elliot J.

    2015-04-15

    The evolutionarily conserved DNA topoisomerase II beta-binding protein 1 (TopBP1) functions in DNA replication, DNA damage response, and cell survival. We analyzed the role of TopBP1 in human and bovine papillomavirus genome replication. Consistent with prior reports, TopBP1 co-localized in discrete nuclear foci and was in complex with papillomavirus E2 protein. Similar to E2, TopBP1 is recruited to the region of the viral origin of replication during G1/S and early S phase. TopBP1 knockdown increased, while over-expression decreased transient virus replication, without affecting cell cycle. Similarly, using cell lines harboring HPV-16 or HPV-31 genome, TopBP1 knockdown increased while over-expression reduced viral copy number relative to genomic DNA. We propose a model in which TopBP1 serves dual roles in viral replication: it is essential for initiation of replication yet it restricts viral copy number. - Highlights: • Protein interaction study confirmed In-situ interaction between TopBP1 and E2. • TopBP1 present at papillomavirus ori in G1/S and early S phase of cell cycle. • TopBP1 knockdown increased, over-expression reduced virus replication. • TopBP1 protein level change did not influence cell survival or cell cycle. • TopBP1 displaced from papillomavirus ori after initiation of replication.

  6. RanBP2 Modulates Cox11 and Hexokinase I Activities and Haploinsufficiency of RanBP2 Causes Deficits in Glucose Metabolism

    PubMed Central

    Guruju, Mallikarjuna; Oswald, John; Raz, Dorit; Bush, Ronald A; Sieving, Paul A; Lu, Xinrong; Bock, Cheryl B; Ferreira, Paulo A

    2006-01-01

    The Ran-binding protein 2 (RanBP2) is a large multimodular and pleiotropic protein. Several molecular partners with distinct functions interacting specifically with selective modules of RanBP2 have been identified. Yet, the significance of these interactions with RanBP2 and the genetic and physiological role(s) of RanBP2 in a whole-animal model remain elusive. Here, we report the identification of two novel partners of RanBP2 and a novel physiological role of RanBP2 in a mouse model. RanBP2 associates in vitro and in vivo and colocalizes with the mitochondrial metallochaperone, Cox11, and the pacemaker of glycolysis, hexokinase type I (HKI) via its leucine-rich domain. The leucine-rich domain of RanBP2 also exhibits strong chaperone activity toward intermediate and mature folding species of Cox11 supporting a chaperone role of RanBP2 in the cytosol during Cox11 biogenesis. Cox11 partially colocalizes with HKI, thus supporting additional and distinct roles in cell function. Cox11 is a strong inhibitor of HKI, and RanBP2 suppresses the inhibitory activity of Cox11 over HKI. To probe the physiological role of RanBP2 and its role in HKI function, a mouse model harboring a genetically disrupted RanBP2 locus was generated. RanBP2−/− are embryonically lethal, and haploinsufficiency of RanBP2 in an inbred strain causes a pronounced decrease of HKI and ATP levels selectively in the central nervous system. Inbred RanBP2+/− mice also exhibit deficits in growth rates and glucose catabolism without impairment of glucose uptake and gluconeogenesis. These phenotypes are accompanied by a decrease in the electrophysiological responses of photosensory and postreceptoral neurons. Hence, RanBP2 and its partners emerge as critical modulators of neuronal HKI, glucose catabolism, energy homeostasis, and targets for metabolic, aging disorders and allied neuropathies. PMID:17069463

  7. Feasibility study report for the 200-BP-1 operable unit

    SciTech Connect

    Not Available

    1993-06-01

    This feasibility study examines a range of alternatives and provides recommendations for selecting a preferred alternative for remediating contamination at the 200-BP-1 operable unit. The 200-BP-1 operable unit is located in the center of the Hanford Site along the northern boundary of the 200 East Area. The 241-BY Tank Farm is located immediately to the south of the operable unit. 200-BP-1 is a source operable unit with contaminated soils associated primarily with nine inactive cribs (known as the 216-B cribs). These cribs were used for disposal of low-level radioactive liquid waste from U Plant uranium recovery operations, and waste storage tank condensate from the adjacent 241-BY Tank Farm. The cribs used for disposal of U Plant waste were in operation from 1955--1965, and the cribs used for disposal of tank condensate were in operation from 1965--1975. In addition to the cribs, four unplanned releases of radioactive materials have occurred within the operable unit. Contaminated surface soils associated with the unplanned releases have been consolidated over the cribs and covered with clean soil to reduce contaminant migration and exposure. Discharge of wastes to the cribs has resulted in soil and groundwater contamination. The groundwater is being addressed as part of the 200 East Aggregate Area, groundwater operable unit. Contaminated soils at the site can be categorized by the types of contaminants, their distribution in the soil column, and the risk posed by the various potential exposure pathways. Below the clean soil cover, the near surface soils contain low-levels of contamination with cesium-137, radium-226, strontium-90, thorium-228, and uranium. The lifetime incremental cancer risk associated with these soils if they were exposed at the surface is 9{times}10{sup {minus}5}.

  8. Estimating smoothness term for BP stereo matching with sparse disparities

    NASA Astrophysics Data System (ADS)

    He, Junxue; Li, Zhanming

    2011-06-01

    The belief propagation stereo matching algorithm has high computational cost and varied parameters. To address these problems and perform stereo matching in practical applications, we implement BP algorithm on cuda and propose an approach to estimate parameters of smoothness term in the energy function automatically. We use Harris corner detector and Pyramidal KLT feature tracker algorithm to extract a sparse disparity map. The rate of increase in the discontinuity cost can be compute out approximately. Experiments demonstrate that our approach is feasible and the approximate parameters of discontinuity cost can be computed out quickly.

  9. A study of the Crab-like supernova remnant G21.5-0.9 with the Chandra X-ray Observatory

    NASA Astrophysics Data System (ADS)

    Matheson, Heather Colleen

    2006-12-01

    The absence of a supernova remnant (SNR) shell surrounding the Crab and other plerions (pulsar wind nebulae) has been a mystery for three decades. G21.5-0.9 is a particularly intriguing SNR in which the central powering engine (PSR J1833-1034) has been recently detected. Early Chandra observations revealed a faint extended X-ray halo which was associated with the SNR shell; however its spectrum was non-thermal, unlike that expected from an SNR shell. On the other hand, a plerionic origin to the halo was problematic since the X-ray plerion would be larger than the radio plerion. This thesis presents the analysis of an integrated 278 ks of archival Chandra data acquired with the High-Resolution Camera (HRC) and 579 ks aquired with the Advanced CCD Imaging Spectrometer (ACIS). This study presents the deepest and highest resolution images of any plerionic SNR to date. The resulting images reveal for the first time: (1) a limb-brightened morphology in the eastern section of the halo, (2) a rich structure in the inner (40" radius) bright plerion including wisps and a double-lobed morphology with an axis of symmetry running in the northwest- southeast direction, and (3) the dynamic nature of the plerion with knots appearing, moving, and disappearing with time. The spatially resolved spectroscopic study indicates that the photon index steepens with increasing distance from the central point source out to a radius of 40" then becomes constant at ~2.6 in the X-ray halo (for a column density of N H = 2.33 × 10 22 atoms cm -2 ). Evidence of line emission due to Mg, Si, and S was found in the halo's northern knots, indicating that these features are shock-heated ejecta from the SN explosion. The limb lacked the evidence for heavy elements, indicating that it is the SNR, shell (shock-heated ISM). This study illustrates the need for deep Chandra observations to reveal the missing SNR material in Crab-like plerions.

  10. A surface complexation model of YREE sorption on Ulva lactuca in 0.05-5.0 M NaCl solutions

    NASA Astrophysics Data System (ADS)

    Zoll, Alison M.; Schijf, Johan

    2012-11-01

    We present distribution coefficients, log iKS, for the sorption of yttrium and the rare earth elements (YREEs) on BCR-279, a dehydrated tissue homogenate of a marine macroalga, Ulva lactuca, resembling materials featured in chemical engineering studies aimed at designing renewable biosorbents. Sorption experiments were conducted in NaCl solutions of different ionic strength (0.05, 0.5, and 5.0 M) at T = 25 °C over the pH range 2.7-8.5. Distribution coefficients based on separation of the dissolved and particulate phase by conventional filtration (<0.22 μm) were corrected for the effect of colloid-bound YREEs (>3 kDa) using an existing pH-dependent model. Colloid-corrected values were renormalized to free-cation concentrations by accounting for YREE hydrolysis and chloride complexation. At each ionic strength, the pH dependence of the renormalized values is accurately described with a non-electrostatic surface complexation model (SCM) that incorporates YREE binding to three monoprotic functional groups, previously characterized by alkalimetric titration, as well as binding of YREE-hydroxide complexes (MOH2+) to the least acidic one (pKa ∼ 9.5). In non-linear regressions of the distribution coefficients as a function of pH, each pKa was fixed at its reported value, while stability constants of the four YREE surface complexes were used as adjustable parameters. Data for a single fresh U. lactuca specimen in 0.5 M NaCl show generally the same pH-dependent behavior but a lower degree of sorption and were excluded from the regressions. Good linear free-energy relations (LFERs) between stability constants of the YREE-acetate and YREE-hydroxide solution complex and surface complexes with the first and third functional group, respectively, support their prior tentative identifications as carboxyl and phenol. A similar confirmation for the second group is precluded by insufficient knowledge of the stability of YREE-phosphate complexes and a perceived lack of YREE binding

  11. Seismotectonics of the Antalya Basin and surrounding regions in eastern Mediterranean from 8 to 28 December 2013 Mw 5.0-5.8 earthquake sequence

    NASA Astrophysics Data System (ADS)

    Görgün, Ethem; Kalafat, Doğan; Kekovalı, Kıvanç

    2016-05-01

    The 8-28 December 2013 Mw 5.0-5.8 Antalya Basin earthquake sequence in eastern Mediterranean is examined. Centroid moment tensors for 16 earthquakes with moment magnitudes (Mw) between 3.6 and 5.8 are determined by applying a waveform inversion method. All earthquakes are shallow focus thrust events at a depth of 40-45 km. The seismic moments (Mo) of the earthquakes are estimated as 4.10 × 1016-5.54 × 1017 N m and rupture durations of the mainshocks are 20-22 s. The focal mechanisms of the aftershocks are mainly thrust faulting with a strike-slip component and reveal NW-SE trending direction of T-axis in the entire activated region. According to high-resolution hypocenter relocation of the Antalya earthquake sequence, seven main clusters are revealed. The aftershock activity in the observation period between 1 December 2013 and 23 January 2015 extends in an N to S direction. A seismic cross-section indicates that a complex pattern of the hypocenter distribution with the activation of seven segments. The westernmost cluster (cluster 1) is associated with a fault plane trending mainly WNW-ESE and dipping vertical, while the cluster 5 is related to a fault plane trending NNE-SSW and dipping towards SSE. The best constrained focal depths indicate that the aftershock sequence is mainly confined in the crust (depth < 40 km) and are operating in the approximate depth range from 3 to 110 km. A stress tensor inversion of focal mechanism data is performed to obtain a more precise picture of the Antalya Basin stress field. The stress tensor inversion results indicate a predominant thrust stress regime with a NE-SW oriented maximum horizontal compressive stress (SH). According to variance of the stress tensor inversion, to first order, the Antalya Basin is characterized by a homogeneous interplate stress field. The Coulomb stress change associated with two mainshocks are also investigated to evaluate any significant enhancement of stresses along the Antalya Basin and

  12. Expression and Localization of CaBP Ca2+ Binding Proteins in the Mouse Cochlea.

    PubMed

    Yang, Tian; Scholl, Elizabeth S; Pan, Ning; Fritzsch, Bernd; Haeseleer, Françoise; Lee, Amy

    2016-01-01

    CaBPs are a family of EF-hand Ca2+ binding proteins that are structurally similar to calmodulin. CaBPs can interact with, and yet differentially modulate, effectors that are regulated by calmodulin, such as Cav1 voltage-gated Ca2+ channels. Immunolabeling studies suggest that multiple CaBP family members (CaBP1, 2, 4, and 5) are expressed in the cochlea. To gain insights into the respective auditory functions of these CaBPs, we characterized the expression and cellular localization of CaBPs in the mouse cochlea. By quantitative reverse transcription PCR, we show that CaBP1 and CaBP2 are the major CaBPs expressed in mouse cochlea both before and after hearing onset. Of the three alternatively spliced variants of CaBP1 (caldendrin, CaBP1-L, and CaBP1-S) and CaBP2 (CaBP2-alt, CaBP2-L, CaBP2-S), caldendrin and CaBP2-alt are the most abundant. By in situ hybridization, probes recognizing caldendrin strongly label the spiral ganglion, while probes designed to recognize all three isoforms of CaBP1 weakly label both the inner and outer hair cells as well as the spiral ganglion. Within the spiral ganglion, caldendrin/CaBP1 labeling is associated with cells resembling satellite glial cells. CaBP2-alt is strongly expressed in inner hair cells both before and after hearing onset. Probes designed to recognize all three variants of CaBP2 strongly label inner hair cells before hearing onset and outer hair cells after the onset of hearing. Thus, CaBP1 and CaBP2 may have overlapping roles in regulating Ca2+ signaling in the hair cells, and CaBP1 may have an additional function in the spiral ganglion. Our findings provide a framework for understanding the role of CaBP family members in the auditory periphery. PMID:26809054

  13. Expression and Localization of CaBP Ca2+ Binding Proteins in the Mouse Cochlea

    PubMed Central

    Pan, Ning; Fritzsch, Bernd; Haeseleer, Françoise; Lee, Amy

    2016-01-01

    CaBPs are a family of EF-hand Ca2+ binding proteins that are structurally similar to calmodulin. CaBPs can interact with, and yet differentially modulate, effectors that are regulated by calmodulin, such as Cav1 voltage-gated Ca2+ channels. Immunolabeling studies suggest that multiple CaBP family members (CaBP1, 2, 4, and 5) are expressed in the cochlea. To gain insights into the respective auditory functions of these CaBPs, we characterized the expression and cellular localization of CaBPs in the mouse cochlea. By quantitative reverse transcription PCR, we show that CaBP1 and CaBP2 are the major CaBPs expressed in mouse cochlea both before and after hearing onset. Of the three alternatively spliced variants of CaBP1 (caldendrin, CaBP1-L, and CaBP1-S) and CaBP2 (CaBP2-alt, CaBP2-L, CaBP2-S), caldendrin and CaBP2-alt are the most abundant. By in situ hybridization, probes recognizing caldendrin strongly label the spiral ganglion, while probes designed to recognize all three isoforms of CaBP1 weakly label both the inner and outer hair cells as well as the spiral ganglion. Within the spiral ganglion, caldendrin/CaBP1 labeling is associated with cells resembling satellite glial cells. CaBP2-alt is strongly expressed in inner hair cells both before and after hearing onset. Probes designed to recognize all three variants of CaBP2 strongly label inner hair cells before hearing onset and outer hair cells after the onset of hearing. Thus, CaBP1 and CaBP2 may have overlapping roles in regulating Ca2+ signaling in the hair cells, and CaBP1 may have an additional function in the spiral ganglion. Our findings provide a framework for understanding the role of CaBP family members in the auditory periphery. PMID:26809054

  14. Geochemical multielement signatures of glacial and interglacial facies of the Okhotsk Sea deepwater sediments during the past 350 kyr: A response to global climate changes at the orbital and millennial scales

    NASA Astrophysics Data System (ADS)

    Chebykin, Eugene P.; Gorbarenko, Sergey A.; Stepanova, Ol'ga G.; Panov, Vsevolod S.; Goldberg, Evgeny L.

    2015-03-01

    The previously dated deepwater sediment core MR06-04 PC-7R (length 1723 cm; 350 kyr) recovered from the central Okhotsk Sea (OS) was analyzed for biogenic compounds and for 63 chemical elements (using the inductively coupled plasma-mass spectrometry method) with a high resolution (1 cm; ~200 years). A one box model with two main members" and mathematical methods (based on multielemental composition of sediments) for the calculation of weight fractions (at each time slice) of two main types of geochemical facies that dominate during considerably diverse climatic periods (glacial maxima and interglacial optima) were proposed and tested. This model can be applied to other analogous natural systems whose sedimentation is driven by two main types of geochemical facies. The application of the developed model to the studied core revealed that variations of weight fractions of the typical interglacial and glacial geochemical facies in the sediments along the core depth (named as warm and cold "covariators," respectively) change synchronously with global and regional climate variability. Profiles of warm and inversed cold covariators coincide tightly, and their values increase during warm marine isotope stages and substages and decrease during cold ones over the last 350 kyr. Millennial scale changes in covariators had occurred simultaneously with abrupt variability in the OS productivity and sediment lithology and with millennial global climate variability. Some discrepancies in the warm and inversed cold covariators calculated using specific mathematical treatments revealed the episodic influence of volcanogenic matter presented in the core by visible tephra layers and cryptotephras.

  15. AMP-activated protein kinase phosphorylates CtBP1 and down-regulates its activity

    SciTech Connect

    Kim, Jae-Hwan; Choi, Soo-Youn; Kang, Byung-Hee; Lee, Soon-Min; Cho, Eun-Jung; Youn, Hong-Duk

    2013-02-01

    Highlights: ► AMPK phosphorylates CtBP1 on serine 158. ► AMPK-mediated phosphorylation of CtBP1 causes the ubiquitination and nuclear export of CtBP1. ► AMPK downregulates the CtBP1-mediated repression of Bax transcription. -- Abstract: CtBP is a transcriptional repressor which plays a significant role in the regulation of cell proliferation and tumor progression. It was reported that glucose withdrawal causes induction of Bax due to the dissociation of CtBP from the Bax promoter. However, the precise mechanism involved in the regulation of CtBP still remains unclear. In this study, we found that an activated AMP-activated protein kinase (AMPK) phosphorylates CtBP1 on Ser-158 upon metabolic stresses. Moreover, AMPK-mediated phosphorylation of CtBP1 (S158) attenuates the repressive function of CtBP1. We also confirmed that triggering activation of AMPK by various factors resulted in an increase of Bax gene expression. These findings provide connections of AMPK with CtBP1-mediated regulation of Bax expression for cell death under metabolic stresses.

  16. Phosphorylation and Rapid Relocalization of 53BP1 to Nuclear Foci upon DNA Damage

    PubMed Central

    Anderson, Lindsay; Henderson, Catherine; Adachi, Yasuhisa

    2001-01-01

    53BP1 is a human BRCT protein that was originally identified as a p53-interacting protein by the Saccharomyces cerevisiae two-hybrid screen. Although the carboxyl-terminal BRCT domain shows similarity to Crb2, a DNA damage checkpoint protein in fission yeast, there is no evidence so far that implicates 53BP1 in the checkpoint. We have identified a Xenopus homologue of 53BP1 (XL53BP1). XL53BP1 is associated with chromatin and, in some cells, localized to a few large foci under normal conditions. Gamma-ray irradiation induces increased numbers of the nuclear foci in a dose-dependent manner. The damage-induced 53BP1 foci appear rapidly (in 30 min) after irradiation, and de novo protein synthesis is not required for this response. In human cells, 53BP1 foci colocalize with Mrel1 foci at later stages of the postirradiation period. XL53BP1 is hyperphosphorylated after X-ray irradiation, and inhibitors of ATM-related kinases delay the relocalization and reduce the phosphorylation of XL53BP1 in response to X-irradiation. In AT cells, which lack ATM kinase, the irradiation-induced responses of 53BP1 are similarly affected. These results suggest a role for 53BP1 in the DNA damage response and/or checkpoint control which may involve signaling of damage to p53. PMID:11238909

  17. IGF2BP3 modulates the interaction of invasion-associated transcripts with RISC

    PubMed Central

    Ennajdaoui, Hanane; Howard, Jonathan M.; Sterne-Weiler, Timothy; Jahanbani, Fereshteh; Coyne, Doyle J.; Uren, Philip J.; Dargyte, Marija; Katzman, Sol; Draper, Jolene M.; Wallace, Andrew; Cazarez, Oscar; Burns, Suzanne C.; Qiao, Mei; Hinck, Lindsay; Smith, Andrew D.; Toloue, Masoud M.; Blencowe, Benjamin J.; Penalva, Luiz O.F.; Sanford, Jeremy R.

    2016-01-01

    Summary Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) expression correlates with malignancy. But its role(s) in pathogenesis remain enigmatic. Here, we interrogated the IGF2BP3-RNA interaction network in pancreatic ductal adenocarcinoma (PDAC) cells. Using a combination of genome-wide approaches we identify 164 direct mRNA targets of IGF2BP3. These transcripts encode proteins enriched for functions such as cell migration, proliferation and adhesion. Loss of IGF2BP3 reduced PDAC cell invasiveness and remodeled focal adhesion junctions. Individual-nucleotide resolution crosslinking immunoprecipitation (iCLIP) revealed significant overlap of IGF2BP3 and miRNA binding sites. IGF2BP3 promotes association of the RNA induced silencing complex (RISC) with specific transcripts. Our results show that IGF2BP3 influences a malignancy-associated RNA regulon by modulating miRNA-mRNA interactions. PMID:27210763

  18. IGF2BP3 Modulates the Interaction of Invasion-Associated Transcripts with RISC.

    PubMed

    Ennajdaoui, Hanane; Howard, Jonathan M; Sterne-Weiler, Timothy; Jahanbani, Fereshteh; Coyne, Doyle J; Uren, Philip J; Dargyte, Marija; Katzman, Sol; Draper, Jolene M; Wallace, Andrew; Cazarez, Oscar; Burns, Suzanne C; Qiao, Mei; Hinck, Lindsay; Smith, Andrew D; Toloue, Masoud M; Blencowe, Benjamin J; Penalva, Luiz O F; Sanford, Jeremy R

    2016-05-31

    Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) expression correlates with malignancy, but its role(s) in pathogenesis remains enigmatic. We interrogated the IGF2BP3-RNA interaction network in pancreatic ductal adenocarcinoma (PDAC) cells. Using a combination of genome-wide approaches, we have identified 164 direct mRNA targets of IGF2BP3. These transcripts encode proteins enriched for functions such as cell migration, proliferation, and adhesion. Loss of IGF2BP3 reduced PDAC cell invasiveness and remodeled focal adhesion junctions. Individual nucleotide resolution crosslinking immunoprecipitation (iCLIP) revealed significant overlap of IGF2BP3 and microRNA (miRNA) binding sites. IGF2BP3 promotes association of the RNA-induced silencing complex (RISC) with specific transcripts. Our results show that IGF2BP3 influences a malignancy-associated RNA regulon by modulating miRNA-mRNA interactions. PMID:27210763

  19. Phosphorylated 4E-BP1 is Associated with Poor Survival in Melanoma

    PubMed Central

    O’Reilly, Kathryn E.; Warycha, Melanie; Davies, Michael A.; Rodrik, Vanessa; Zhou, Xi K.; Yee, Herman; Polsky, David; Pavlick, Anna C.; Rosen, Neal; Bhardwaj, Nina; Mills, Gordon; Osman, Iman

    2009-01-01

    Purpose Both the PI3K/AKT and RAS/MAPK signal transduction pathways mediate 4E-BP1 phosphorylation, releasing 4E-BP1 from the mRNA cap and permitting translation initiation. Given the prevalence of PTEN and B-RAF mutations in melanoma, we first examined translation initiation, as measured by phosphorylated 4E-BP1, in metastatic melanoma tissues and cell lines. We then tested the association between amounts of total and phosphorylated 4E-BP1 and patient survival. Experimental Design Seven human metastatic melanoma cells lines and 72 metastatic melanoma patients with accessible metastatic tumor tissues and extended follow up information were studied. Expression of 4E-BP1 transcript, total 4E-BP1 protein, and phosphorylated 4E-BP1 were examined. The relationship between 4E-BP1 transcript and protein expression was assessed in a subset of patient tumors (n=41). The association between total and phospho-4E-BP1 levels and survival was examined in the larger cohort of patients (n=72). Results 4E-BP1 was hyperphosphorylated in 4/7 melanoma cell lines harboring BRAF and PTEN mutations as compared to untransformed melanocytes or RAS/RAF/PTEN wild type melanoma cells. 4E-BP1 transcript correlated with 4E-BP1 total protein levels as measured by the semi-quantitative reverse phase protein array (p=0.012). High levels of phosphorylated 4E-BP1 were associated with worse overall and post-recurrence survival (p=0.02, 0.0003 respectively). Conclusion Our data demonstrate that translation initiation is a common event in human metastatic melanoma and correlates with worse prognosis. Therefore, effective inhibition of the pathways responsible for 4E-BP1 phosphorylation should be considered to improve the treatment outcome of metastatic melanoma patients. PMID:19336517

  20. SPECTROPOLARIMETRY OF THE CLASSICAL T TAURI STAR BP TAU

    SciTech Connect

    Chen, Wei; Johns-Krull, Christopher M. E-mail: cmj@rice.edu

    2013-10-20

    We implement a least-squares deconvolution (LSD) code to study magnetic fields on cool stars. We first apply our code to high-resolution optical echelle spectra of 53 Cam (a magnetic Ap star) and three well-studied cool stars (Arcturus, 61 Cyg A, and ξ Boo A) as well as the Sun (by observing the asteroid Vesta) as tests of the code and the instrumentation. Our analysis is based on several hundred photospheric lines spanning the wavelength range 5000 Å to 9000 Å. We then apply our LSD code to six nights of data on the Classical T Tauri Star BP Tau. A maximum longitudinal field of 370 ± 80 G is detected from the photospheric lines on BP Tau. A 1.8 kG dipole tilted at 129° with respect to the rotation axis and a 1.4 kG octupole tilted at 104° with respect to the rotation axis, both with a filling factor of 0.25, best fit our LSD Stokes V profiles. Measurements of several emission lines (He I 5876 Å, Ca II 8498 Å, and 8542 Å) show the presence of strong magnetic fields in the line formation regions of these lines, which are believed to be the base of the accretion footpoints. The field strength measured from these lines shows night-to-night variability consistent with rotation of the star.

  1. Spectropolarimetry of the Classical T Tauri Star BP Tau

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Johns-Krull, Christopher M.

    2013-10-01

    We implement a least-squares deconvolution (LSD) code to study magnetic fields on cool stars. We first apply our code to high-resolution optical echelle spectra of 53 Cam (a magnetic Ap star) and three well-studied cool stars (Arcturus, 61 Cyg A, and ξ Boo A) as well as the Sun (by observing the asteroid Vesta) as tests of the code and the instrumentation. Our analysis is based on several hundred photospheric lines spanning the wavelength range 5000 Å to 9000 Å. We then apply our LSD code to six nights of data on the Classical T Tauri Star BP Tau. A maximum longitudinal field of 370 ± 80 G is detected from the photospheric lines on BP Tau. A 1.8 kG dipole tilted at 129° with respect to the rotation axis and a 1.4 kG octupole tilted at 104° with respect to the rotation axis, both with a filling factor of 0.25, best fit our LSD Stokes V profiles. Measurements of several emission lines (He I 5876 Å, Ca II 8498 Å, and 8542 Å) show the presence of strong magnetic fields in the line formation regions of these lines, which are believed to be the base of the accretion footpoints. The field strength measured from these lines shows night-to-night variability consistent with rotation of the star.

  2. Characterization of the influence of a favorable pressure gradient on the basic structure of a mach 5.0 high reynolds number supersonic turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Tichenor, Nathan Ryan

    decomposition of the Reynolds stress for each pressure gradient case. It was shown that the effect of curvature-driven favorable pressure gradients on the turbulent structure of a supersonic boundary layer was significant. For the strong pressure gradient model, the turbulent shear stress changed sign throughout the entire boundary layer; a phenomena was not observed to this magnitude in previous studies. Additionally, significant changes were seen in the turbulent structure of the boundary layer. It is believed that hairpin vortices organized within the boundary layer are stretched and then broken up over the favorable pressure gradient. Energy from these hairpin structures is transferred to smaller turbulent eddies as well as back into the mean flow creating a fuller mean velocity profile. It was determined that the effects of favorable pressure gradients on the basic structure of a turbulent Mach 5.0 boundary layer were significant, therefore increasing the complexity of computational modeling.

  3. Silencing of CtBP1 suppresses the migration in human glioma cells.

    PubMed

    Zhao, Chengjin; Shen, Yifen; Tao, Xuelei; Xu, Jian; Lu, Junjie; Liu, Chao; Xu, Zhiwei; Tang, Qing; Tao, Tao; Zhang, Xiubing

    2016-06-01

    Carboxyl-terminal binding protein 1 (CtBP1), up-regulated in various types of human cancers, has been functionally associated with proliferation, anti-apoptosis, and EMT in vitro studies. However, the functional significance of CtBP1 in the pathophysiology of glioma remains unknown. In the present study, we showed the expression of CtBP1 was markedly higher in glioma tissues compared with normal brain tissues by Western blot analysis. Immunohistochemical analysis revealed that CtBP1 mainly localized in the nucleus of glioma cells. Statistical analysis suggested the upregulation of CtBP1 was considerably correlated with the WHO grade (P < 0.05) and those patients with high CtBP1 levels exhibited shorter survival time (P < 0.01). Silencing CtBP1 by short hairpin RNAi caused an inhibition of cell migration. Moreover, knockdown of CtBP1 increases E-cadherin expression and decreases vimentin expression. These data uncovered that CtBP1 protein is a valuable marker of glioma pathogenic process and that CtBP1 can serve as a novel prognostic marker for glioma therapy. PMID:27160109

  4. E4BP4 is a cardiac survival factor and essential for embryonic heart development.

    PubMed

    Weng, Yi-Jiun; Hsieh, Dennis Jine-Yuan; Kuo, Wei-Wen; Lai, Tung-Yuan; Hsu, Hsi-Hsien; Tsai, Chang-Hai; Tsai, Fuu-Jen; Lin, Ding-Yu; Lin, James A; Huang, Chih-Yang; Tung, Kwong-Chung

    2010-07-01

    The bZIP transcription factor E4BP4, has been demonstrated to be a survival factor in pro-B lymphocytes. GATA factors play important roles in transducing the IL-3 survival signal and transactivating the downstream survival gene, E4BP4. In heart, GATA sites are essential for proper transcription of several cardiac genes, and GATA-4 is a mediator of cardiomyocyte survival. However, the role E4BP4 plays in heart is still poorly understood. In this study, Dot-blot hybridization assays using Dig-labeled RNA probes revealed that the E4BP4 gene was expressed in cardiac tissue from several species including, monkey, dog, rabbit, and human. Western blot analysis showed that the E4BP4 protein was consistently present in all of these four species. Furthermore, immunohistochemistry revealed that the E4BP4 protein was overexpressed in diseased heart tissue in comparison with normal heart tissue. In addition, the overexpression of E4BP4 in vitro activated cell survival signaling pathway of cardiomyocytes. At last, siRNA-mediated knock down of E4BP4 in zebrafish resulted in malformed looping of the embryonic heart tube and decreased heart beating. Based on these results, we conclude that E4BP4 plays as a survival factor in heart and E4BP4 is essential for proper embryonic heart development. PMID:20186462

  5. An Analysis of the Rapidly Rotating Bp star HD 133880

    NASA Technical Reports Server (NTRS)

    Bailey, J. D.; Grunhut, J.; Shultz, M.; Wade, G.; Landstreet, J. D.; Bohlender, D.; Lim, J.; Wong, K.; Drake, S.; Linsky, J.

    2012-01-01

    HD 133880 is a rapidly rotating chemically peculiar B-type (Bp) star (nu sin i approx = 103km/s) and is host to one of the strongest magnetic fields of any Ap/Bp star. A member of the Upper Centaurus Lupus association, it is a star with a well-determined age of 16 Myr. 12 new spectra, four of which are polarimetric, obtained from the FEROS, ESPaDOnS and HARPS instruments, provide sufficient material from which to re-evaluate the magnetic field and obtain a first approximation to the atmospheric abundance distributions of He, O, Mg, Si, Ti. Cr, Fe, Ni, Pr and Nd. An abundance analysis was carried out using ZEEMAN, a program which synthesizes spectral line profiles for stars with permeating magnetic fields. The magnetic field structure was characterized by a colinear multipole expansion from the observed variations of the longitudinal and surface fields with rotational phase. Both magnetic hemispheres are clearly visible during the stellar rotation, and thus a three-ring abundance distribution model encompassing both magnetic poles and magnetic equator with equal spans in colatitude was adopted. Using the new magnetic field measurements and optical photometry together with previously published data, we refine the period of HD 133880 to P = 0.877 476 +/- 0.000009 d. Our simple axisymmetric magnetic field model is based on a predominantly quadrupolar component that roughly describes the field variations. Using spectrum synthesis, we derived mean abundances for O, Mg, Si, Ti, Cr, Fe and Pr. All elements; except Mg, are overabundant compared to the Son. Mg appears to be approximately uniform over the stellar surface, while all other elements are more abundant in the negative magnetic hemisphere than in the positive magnetic hemisphere. In contrast to most Ap/Bp stars which show an underabundance in 0, in HD 133880 this element is clearly overabundant compared to the solar abundance ratio. In studying the Ha and Paschen lines in the optical spectra, we could not

  6. Identify Melatonin as a Novel Therapeutic Reagent in the Treatment of 1-Bromopropane(1-BP) Intoxication

    PubMed Central

    Xu, Yongpeng; Wang, Shuo; Jiang, Lulu; Wang, Hui; Yang, Yilin; Li, Ming; Wang, Xujing; Zhao, Xiulan; Xie, Keqin

    2016-01-01

    Abstract 1-Bromopropane (1-BP) has been used as an alternative for fluoride compounds and 1-BP intoxication may involve lung, liver, and central neural system (CNS). Our previous studies showed that 1-BP impaired memory ability by compromising antioxidant cellular defenses. Melatonin is a powerful endogenous antioxidant, and the objective of this study was to explore the therapeutic role of melatonin in the treatment of 1-BP intoxication. Rats were intragastrically treated with 1-BP with or without melatonin, and then sacrificed on 27th day after 1-BP administration. The Morris water maze (MWM) test was used to evaluate the spatial learning and memory ability of the experimental animals, and NeuN staining was performed to assess neuron loss in hippocampus. We found that rats treated with 1-BP spent more time and swam longer distance before landing on the hidden platform with a comparable swimming speed, which was markedly mitigated by the pretreatment with melatonin in a concentration-dependent manner. In addition, 1-BP-induced notable decrease in neuron population in hippocampus by promoting apoptosis, and melatonin pretreatment attenuated those changes in brain. The GSH/GSSG ratio was proportionately decreased and heme oxygenase 1 was increased in the rats exposed to 1-BP (Figure 6), and administration of melatonin restored them. Meanwhile, MDA, the level of lipid peroxidation product, was significantly increased upon exposed to 1-BP, which was significantly attenuated by melatonin pretreatment, indicating that administration of 1-BP could interfere with redox homeostasis of brain in rat, and such 1-BP-induced biomedical changes were reversed by treatment with melatonin. We conclude that treatment with melatonin attenuates 1-BP-induced CNS toxicity through its ROS scavenging effect. PMID:26817862

  7. Identify Melatonin as a Novel Therapeutic Reagent in the Treatment of 1-Bromopropane(1-BP) Intoxication.

    PubMed

    Xu, Yongpeng; Wang, Shuo; Jiang, Lulu; Wang, Hui; Yang, Yilin; Li, Ming; Wang, Xujing; Zhao, Xiulan; Xie, Keqin

    2016-01-01

    1-Bromopropane (1-BP) has been used as an alternative for fluoride compounds and 1-BP intoxication may involve lung, liver, and central neural system (CNS). Our previous studies showed that 1-BP impaired memory ability by compromising antioxidant cellular defenses. Melatonin is a powerful endogenousantioxidant, and the objective of this study was to explore the therapeutic role of melatonin in the treatment of 1-BP intoxication. Rats were intragastrically treated with 1-BP with or without melatonin, and then sacrificed on 27th day after 1-BP administration. The Morris water maze (MWM) test was used to evaluate the spatial learning and memory ability of the experimental animals, and NeuN staining was performed to assess neuron loss in hippocampus. We found that rats treated with 1-BP spent more time and swam longer distance before landing on the hidden platform with a comparable swimming speed, which was markedly mitigated by the pretreatment with melatonin in a concentration-dependent manner. In addition, 1-BP-induced notable decrease in neuron population in hippocampus by promoting apoptosis, and melatonin pretreatment attenuated those changes in brain. The GSH/GSSG ratio was proportionately decreased and heme oxygenase 1 was increased in the rats exposed to 1-BP (Figure 6), and administration of melatonin restored them. Meanwhile, MDA, the level of lipid peroxidation product, was significantly increased upon exposed to 1-BP, which was significantly attenuated by melatonin pretreatment, indicating that administration of 1-BP could interfere with redox homeostasis of brain in rat, and such 1-BP-induced biomedical changes were reversed by treatment with melatonin.We conclude that treatment with melatonin attenuates 1-BP-induced CNS toxicity through its ROS scavenging effect. PMID:26817862

  8. A photometric and spectrographic study of BP Pegasi

    SciTech Connect

    Kim, C.; Mcnamara, D.H.; Joner, M.D. Brigham Young Univ., Provo, UT )

    1989-11-01

    Photometric (uvby beta) and spectrographic observations of the dwarf Cepheid BP Peg are discussed. The observations are used to derive a reddening value of E(b-y) = 0.067 m. An effective temperature of 7470 K, a mean surface gravity, log g = 3.85, and a Fe/H abundance ratio of - 0.08 are obtained. Pulsation theory and stellar model sequences yield M(bol) = 1.4 m, mass = 1.85 solar masses, and age = 1.3 X 10 to the 9th yrs. Also, the radial-velocity data show a mean radial velocity of - 30 km/s and a total velocity range of 36 km/s. 14 refs.

  9. BP Cherry Point Cogeneration Project, Draft Environmental Impact Statement

    SciTech Connect

    N /A

    2003-09-19

    BP West Coast Products, LLC (BP or the Applicant) proposes to construct and operate a nominal 720-megawatt (MW), natural-gas-fired, combined-cycle cogeneration facility next to the existing BP Cherry Point Refinery in Whatcom County, Washington. The Applicant also owns and operates the refinery, but the cogeneration facility and the refinery would be operated as separate business units. The cogeneration facility and its ancillary infrastructure would provide steam and 85 MW of electricity to meet the operating needs of the refinery and 635 MW of electrical power for local and regional consumption. The proposed cogeneration facility would be located between Ferndale and Blaine in northwestern Whatcom County, Washington. The Canadian border is approximately 8 miles north of the proposed project site. The Washington State Energy Facility Site Evaluation Council (EFSEC) has jurisdiction over the evaluation of major energy facilities including the proposed project. As such, EFSEC will recommend approval or denial of the proposed cogeneration facility to the governor of Washington after an environmental review. On June 3, 2002, the Applicant filed an Application for Site Certification (ASC No. 2002-01) with EFSEC in accordance with Washington Administrative Code (WAC) 463-42. On April 22, 2003, the Applicant submitted an amended ASC that included, among other things, a change from air to water cooling. With the submission of the ASC and in accordance with the State Environmental Policy Act (SEPA) (WAC 463-47), EFSEC is evaluating the siting of the proposed project and conducting an environmental review with this Environmental Impact Statement (EIS). Because the proposed project requires federal agency approvals and permits, this EIS is intended to meet the requirements under both SEPA and the National Environmental Policy Act (NEPA). The Bonneville Power Administration (Bonneville) and U.S. Army Corps of Engineers (Corps) also will use this EIS as part of their

  10. Morphologic and Geochronological constraints on the long (> Ma) and short (10-100 Kyr) term vertical rates on south Tibetan normal faults.

    NASA Astrophysics Data System (ADS)

    Kali, E.; van der Woerd, J.; Arnaud, N.; Leloup, P. H.; Mahéo, G.; Liu-Zeng, J.; Chevalier, M. L.; Lacassin, R.; Tapponnier, P.; Thuizat, R.

    2009-04-01

    Quantification of slip and exhumation rates along the long recognized north-south trending active normal faults of the Tibetan plateau are key data in order to constrain mechanical models of the geodynamic evolution of the India-Asia convergence zone. In this study, we combine morphologic, structural, petrological analysis and low to medium thermo-chronology of Quaternary and basement rocks in order to compare short-term and long-term fault rates along two of the main Tibetan rifts systems: Yadong-Gulu and Xainza-Dinggye. At the southern end of the Xainza-Dingyye rift system the Ama Drime range (Everest region) is a horst flanked on each side by N-S trending ductile normal shear zones and active normal faults. Petrological studies combined with U/Pb and Ar/Ar geochronology reveal that the horst formation induced an exhumation on the order of 2 to 4 kbar (7 to 15 km), starting at ~12 Ma. This corresponds to exhumation rates of 0.6 to 1.3 mm/year. Low temperature geochronology (apatite (U-Th)/He dating) indicate Pliocene apparent exhumation rates of about 1 mm/yr since ~5 Ma for the whole massif (this study, Jessup et al., 2008). Short term fault rates can be obtained using cosmogenic nuclide exposure ages of offset geomorphic features such as terraces or moraines. Such features are abundant along the western flank of the Ama Drime range, where the Kharta active fault separates the range from the Kharta basin where the Arun river has abandoned fluvial terraces. The river crosses the fault three times carving deep gorges into the footwall before finally crossing the Himalayas. In the southern part of the Kharta basin, river terraces ~100 m above the present riverbed are offset between 10 and 15 m by one branch of the normal fault. 10Be cosmogenic nuclide exposure ages of these terraces range between 9 and 11 kyr, consistent with aggradation after the Last Glacial Maximum (LGM ~20 ka), followed by rapid incision of the Arun. Together, offsets and ages imply a vertical

  11. Trypanosoma cruzi: specific detection of parasites by PCR in infected humans and vectors using a set of primers (BP1/BP2) targeted to a nuclear DNA sequence.

    PubMed

    Silber, A M; Búa, J; Porcel, B M; Segura, E L; Ruiz, A M

    1997-03-01

    In the present work we evaluate Trypanosoma cruzi DNA detection by PCR using the nuclear oligonucleotides BP1/BP2 as primers. These primers are targeted to the 5' and 3' ends of the coding region for the flagellar protein F29. An amplification product of BP1/BP2 is a DNA band 692 bp long. Titration assays were performed to evaluate the minimum amount of parasite DNA that can be detected by this assay, resulting in 10 fg (equivalent to about 1/20 of the genome). The assay was also performed using T. cruzi DNA from different strains, clones, and human-derived isolates obtaining, in all cases, amplification products. No DNA amplification was observed when the PCR was performed using DNA from Leishmania braziliensis, but when T. rangeli DNA was used, a 615-bp-long fragment was amplified. Under appropriate gel conditions T. cruzi and T. rangeli DNA amplicons could be differentiated. When both conventional xenodiagnosis and PCR detection of parasite DNA in the feces of insect vectors fed with blood from infected patients were compared, 10 of 20 samples were positive by both techniques. However, 2 other samples with positive serology were also positive by PCR. When PCR was performed on blood samples from infected and uninfected individuals, 62 of 65 serologically positive human samples amplified the BP1/BP2 692-bp T. cruzi DNA fragment (sensitivity >95%). The 3 negative samples were positive when Southern blot hybridization was performed using the radiolabeled PCR amplification product as probe (sensitivity 100%). PMID:9085919

  12. Lamin A/C-dependent interaction with 53BP1 promotes cellular responses to DNA damage

    PubMed Central

    Gibbs-Seymour, Ian; Markiewicz, Ewa; Bekker-Jensen, Simon; Mailand, Niels; Hutchison, Christopher J

    2015-01-01

    Lamins A/C have been implicated in DNA damage response pathways. We show that the DNA repair protein 53BP1 is a lamin A/C binding protein. In undamaged human dermal fibroblasts (HDF), 53BP1 is a nucleoskeleton protein. 53BP1 binds to lamins A/C via its Tudor domain, and this is abrogated by DNA damage. Lamins A/C regulate 53BP1 levels and consequently lamin A/C-null HDF display a 53BP1 null-like phenotype. Our data favour a model in which lamins A/C maintain a nucleoplasmic pool of 53BP1 in order to facilitate its rapid recruitment to sites of DNA damage and could explain why an absence of lamin A/C accelerates aging. PMID:25645366

  13. About the {open_quotes}Asian{close_quotes}-specific 9-bp deletion of mtDNA...

    SciTech Connect

    Torroni, A.; Petrozzi, M.; Santolamazza, P.

    1995-08-01

    The 9-bp deletion between the COII and tRNA{sup Lys} genes is due to the lack of one of two adjacent copies of a 9-bp sequence usually present in human mtDNA. This mutation is very common in Asians and populations of Asian ancestry (e.g., Polynesians and Amerinds) and often has been considered and ethnic-specific polymorphism for these populations. We now report the detection of the COII-tRNA{sup Lys} 9-bp deletion in an individual of Italian descent. To our knowledge, this is the first time that the 9-bp deletion has been observed in Europeans. 19 refs.

  14. The relationship between prenatal exposure to BP-3 and Hirschsprung's disease.

    PubMed

    Huo, Weiwei; Cai, Peng; Chen, Minjian; Li, Hongxing; Tang, Junwei; Xu, Chao; Zhu, Dongmei; Tang, Weibing; Xia, Yankai

    2016-02-01

    Hirschsprung's disease (HSCR) is neonatal intestinal abnormality which derived from the faliure of enteric neural crest cells migration to hindgut during embryogenesis from 5 to 12 weeks. Currenly, the knowledge of environmental factors contributing to HSCR is still scarce. Benzophenone-3 (BP-3) is one of the most widely used UV filters, and has weak estrogen and strong anti-androgenic effects. In order to examine the effect of maternal BP-3 exposure on development of offspring and explore the potential mechanism, we conducted case and control study and in vitro study. In this work, BP-3 concertrations in maternal urine was detected by ultra-high performance liquid chromatography. Besides, we investigated the cytotoxicity and receptor tyrosine kinase (RET) expression in cells exposed to BP-3. The results showed that maternal BP-3 exposure was associated with offspring's HSCR in the population as well as inhibited migration of 293T and SH-SY5Y cells. What's more, we discovered dose-response relationship between RET expression and BP-3 exposure dose, and miR-218 and some other genes involved in SLIT2/ROBO1-miR-218-RET/PLAG1 pathway were also related to BP-3 exposure. Therefore, we deduced that BP-3 influenced cell migration via SLIT2/ROBO1-miR-218-RET/PLAG1 pathway. Our study firstly revealed the relationship between maternal BP-3 exposure and HSCR as well as its potential mechanism. PMID:26454118

  15. An analysis of the rapidly rotating Bp star HD 133880

    NASA Astrophysics Data System (ADS)

    Bailey, J. D.; Grunhut, J.; Shultz, M.; Wade, G.; Landstreet, J. D.; Bohlender, D.; Lim, J.; Wong, K.; Drake, S.; Linsky, J.

    2012-06-01

    HD 133880 is a rapidly rotating chemically peculiar B-type (Bp) star (v sin i≃ 103 km s-1) and is host to one of the strongest magnetic fields of any Ap/Bp star. A member of the Upper Centaurus Lupus association, it is a star with a well-determined age of 16 Myr. 12 new spectra, four of which are polarimetric, obtained from the FEROS, ESPaDOnS and HARPS instruments, provide sufficient material from which to re-evaluate the magnetic field and obtain a first approximation to the atmospheric abundance distributions of He, O, Mg, Si, Ti, Cr, Fe, Ni, Pr and Nd. An abundance analysis was carried out using ZEEMAN, a program which synthesizes spectral line profiles for stars with permeating magnetic fields. The magnetic field structure was characterized by a colinear multipole expansion from the observed variations of the longitudinal and surface fields with rotational phase. Both magnetic hemispheres are clearly visible during the stellar rotation, and thus a three-ring abundance distribution model encompassing both magnetic poles and magnetic equator with equal spans in colatitude was adopted. Using the new magnetic field measurements and optical photometry together with previously published data, we refine the period of HD 133880 to P= 0.877 476 ± 0.000 009 d. Our simple axisymmetric magnetic field model is based on a predominantly quadrupolar component that roughly describes the field variations. Using spectrum synthesis, we derived mean abundances for O, Mg, Si, Ti, Cr, Fe and Pr. All elements, except Mg, are overabundant compared to the Sun. Mg appears to be approximately uniform over the stellar surface, while all other elements are more abundant in the negative magnetic hemisphere than in the positive magnetic hemisphere. In contrast to most Ap/Bp stars which show an underabundance in O, in HD 133880 this element is clearly overabundant compared to the solar abundance ratio. In studying the Hα and Paschen lines in the optical spectra, we could not unambiguously

  16. Design and characterization of novel antimicrobial peptides, R-BP100 and RW-BP100, with activity against Gram-negative and Gram-positive bacteria.

    PubMed

    Torcato, Inês M; Huang, Yen-Hua; Franquelim, Henri G; Gaspar, Diana; Craik, David J; Castanho, Miguel A R B; Troeira Henriques, Sónia

    2013-03-01

    BP100 is a short cationic antimicrobial peptide with a mechanism of action dependent on peptide-lipid interactions and microbial surface charge neutralization. Although active against Gram-negative bacteria, BP100 is inactive against Gram-positive bacteria. In this study we report two newly designed BP100 analogues, RW-BP100 and R-BP100 that have the Tyr residue replaced with a Trp and/or the Lys residues replaced with an Arg. The new analogues in addition to being active against Gram-negative bacteria, possess activity against all tested Gram-positive bacteria. Mechanistic studies using atomic force microscopy, surface plasmon resonance and fluorescence methodologies reveal that the antibacterial efficiency follows the affinity for bacterial membrane. The studies suggest that the activity of BP100 and its analogues against Gram-negative bacteria is mainly driven by electrostatic interactions with the lipopolysaccharide layer and is followed by binding to and disruption of the inner membrane, whereas activity against Gram-positive bacteria, in addition to electrostatic attraction to the exposed lipoteichoic acids, requires an ability to more deeply insert in the membrane environment, which is favoured with Arg residues and is facilitated in the presence of a Trp residue. Knowledge on the mechanism of action of these antimicrobial peptides provides information that assists in the design of antimicrobials with higher efficacy and broader spectra of action, but also on the design of peptides with higher specificity if required. PMID:23246973

  17. Lyapunov Exponent Criterion in the CR3BP

    NASA Astrophysics Data System (ADS)

    Quarles, Billy; Eberle, Jason; Cuntz, Manfred; Musielak, Zdzislaw

    2010-10-01

    Our specific focus is to describe the motion of an extra solar planet in a binary star system. We aim to accomplish this by using the methods of chaos theory as an alternate method to our previously established Hodograph method in the circular restricted 3-body problem (CR3BP). Previously Eberle et al. (2010) has shown that a parameter space exists depending only on the mass ratio μ and distance ratio ρo which allowed them to identify regions of stability. Our method will validate the previous results while also providing more information relating to the presence of resonances and their effects on orbital stability. We extend the previous studies by increasing the simulation time, applying the method of Lyapunov exponents, calculating the time series spectrum of the orbit, and determining the Lyapunov dimension. The obtained results demonstrate when a system becomes unstable by orbital energy criterion and the method of Lyapunov exponents provides a quantitative classification scale to characterize the instability. By applying the maximum Lyapunov exponent (MLE) to the parameter space, we determine a region of stability with MLE values larger than the surrounding region. The time series spectra and the Lyapunov Dimension methods are used to illustrate the reasons behind the stability plateau which eludes to the resonance phenomena.

  18. The BP oil spill and the bounty of Plaquemines Parish.

    PubMed

    Fertel, Randy

    2011-01-01

    The source of 25 to 30 percent of America's seafood, the Mississippi River Delta's cornucopian world is now uncertain. And yet, even if shrimp, oysters, and finfish are unaffected by the BP Oil Spill - a big if - one can already reflect on the passing of the culture once built upon gathering them. For almost three centuries, levees made life possible along the riverbanks and in the wetlands beyond. Those same levees also ensured the wetlands would eventually melt away into the Gulf. Cutting off the silt left behind during annual river inundations subjected the fragile land to erosion. Sulfur, natural gas, and oil production companies dug twenty thousand miles of canals to gain more direct routes to their fields and to pump out their mineral wealth. This caused salt-water intrusion that killed off plant life and caused more erosion. The world that sustained my Plaquemines ancestors was less subject to collapse following disasters not only because the ecosystem before the wetlands' ongoing loss was then more vibrant, complex, and robust; but also because their lives, especially their culinary lives, were more vibrant, complex, and robust. Life was hard, but when it came to putting food on the table, life followed the seasons. PMID:21591308

  19. Role of Transcriptional Corepressor CtBP1 in Prostate Cancer Progression12

    PubMed Central

    Wang, Rui; Asangani, Irfan A; Chakravarthi, Balabhadrapatruni VSK; Ateeq, Bushra; Lonigro, Robert J; Cao, Qi; Mani, Ram-Shankar; Camacho, Daniel F; McGregor, Natalie; Schumann, Taibriana EW; Jing, Xiaojun; Menawat, Radhika; Tomlins, Scott A; Zheng, Heng; Otte, Arie P; Mehra, Rohit; Siddiqui, Javed; Dhanasekaran, Saravana M; Nyati, Mukesh K; Pienta, Kenneth J; Palanisamy, Nallasivam; Kunju, Lakshmi P; Rubin, Mark A; Chinnaiyan, Arul M; Varambally, Sooryanarayana

    2012-01-01

    Transcriptional repressors and corepressors play a critical role in cellular homeostasis and are frequently altered in cancer. C-terminal binding protein 1 (CtBP1), a transcriptional corepressor that regulates the expression of tumor suppressors and genes involved in cell death, is known to play a role in multiple cancers. In this study, we observed the overexpression and mislocalization of CtBP1 in metastatic prostate cancer and demonstrated the functional significance of CtBP1 in prostate cancer progression. Transient and stable knockdown of CtBP1 in prostate cancer cells inhibited their proliferation and invasion. Expression profiling studies of prostate cancer cell lines revealed that multiple tumor suppressor genes are repressed by CtBP1. Furthermore, our studies indicate a role for CtBP1 in conferring radiation resistance to prostate cancer cell lines. In vivo studies using chicken chorioallantoic membrane assay, xenograft studies, and murine metastasis models suggested a role for CtBP1 in prostate tumor growth and metastasis. Taken together, our studies demonstrated that dysregulated expression of CtBP1 plays an important role in prostate cancer progression and may serve as a viable therapeutic target. PMID:23097625

  20. 76 FR 69712 - Application To Export Electric Energy; BP Energy Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... Application To Export Electric Energy; BP Energy Company AGENCY: Office of Electricity Delivery and Energy... its authority to transmit electric energy from the United States to Canada pursuant to section 202(e... (DOE) issued Order No. EA-315, which authorized BP Energy to transmit electric energy from the...

  1. 76 FR 69713 - Application To Export Electric Energy; BP Energy Company

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... Application To Export Electric Energy; BP Energy Company AGENCY: Office of Electricity Delivery and Energy... its authority to transmit electric energy from the United States to Mexico pursuant to section 202(e... Order No. EA-314, which authorized BP Energy to transmit electric energy from the United States...

  2. TopBP1 deficiency impairs V(D)J recombination during lymphocyte development

    PubMed Central

    Kim, Jieun; Kyu Lee, Sung; Jeon, Yoon; Kim, Yehyun; Lee, Changjin; Ho Jeon, Sung; Shim, Jaegal; Kim, In-Hoo; Hong, Seokmann; Kim, Nayoung; Lee, Ho; Seong, Rho Hyun

    2014-01-01

    TopBP1 was initially identified as a topoisomerase II-β-binding protein and it plays roles in DNA replication and repair. We found that TopBP1 is expressed at high levels in lymphoid tissues and is essential for early lymphocyte development. Specific abrogation of TopBP1 expression resulted in transitional blocks during early lymphocyte development. These defects were, in major part, due to aberrant V(D)J rearrangements in pro-B cells, double-negative and double-positive thymocytes. We also show that TopBP1 was located at sites of V(D)J rearrangement. In TopBP1-deficient cells, γ-H2AX foci were found to be increased. In addition, greater amount of γ-H2AX product was precipitated from the regions where TopBP1 was localized than from controls, indicating that TopBP1 deficiency results in inefficient DNA double-strand break repair. The developmental defects were rescued by introducing functional TCR αβ transgenes. Our data demonstrate a novel role for TopBP1 as a crucial factor in V(D)J rearrangement during the development of B, T and iNKT cells. PMID:24442639

  3. 78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... formal complaint against BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., and... Energy Regulatory Commission Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., ExxonMobil Pipeline Company; Notice of Complaint Take notice that...

  4. 53BP1 foci as a marker of tumor cell radiosensitivity.

    PubMed

    Markova, E; Vasilyev, S; Belyaev, I

    2015-01-01

    Predicting tumor radiosensitivity has yet to be routinely integrated into radiotherapy. We analyzed the possibility to assess radiosensitivity of tumor cells based on endogenous and radiation-induced 53BP1 foci which are molecular markers of DNA double strand breaks (DSB). In eleven tumor cell lines of different origin, radiosensitivity was assessed by surviving cell fraction following irradiation with 2 Gy (SF2). 53BP1 foci were measured at 4 and 12 h post-irradiation by confocal laser microscopy and dedicated software. The correlation of 53BP1 foci and their post-irradiation kinetics with SF2 was assessed using Spearman rank test. The SF2 correlated with both excess of radiation-induced 53BP1 foci per cell at 4 h after irradiation and decay in number of 53BP1 foci from 4 to 12 h post-irradiation. The fraction of cells with multiple endogenous 53BP1 foci also correlated with SF2 of tumor cells. We conclude that the radiosensitivity of tumor cells can be predicted by kinetics of formation and decay of 53BP1 foci after irradiation. For the first time we report that the fraction of cells with multiple endogenous 53BP1 foci can be used as a marker of tumor cell radiosensitivity. PMID:26278144

  5. Overexpressed CacyBP/SIP leads to the suppression of growth in renal cell carcinoma

    SciTech Connect

    Sun, Shiren; Ning, Xiaoxuan; Liu, Jie; Liu, Lili; Chen, Yu; Han, Shuang; Zhang, Yanqi; Liang, Jie; Wu, Kaichun; Fan, Daiming . E-mail: fandaim@fmmu.edu.cn

    2007-05-18

    Calcyclin-binding protein/Siah-1-interacting protein (CacyBP/SIP), a target protein of S100, has been identified as a component of a novel ubiquitinylation complex leading to {beta}-catenin degradation, which was found to be related to the malignant phenotypes of gastric cancer. However, the roles of CacyBP/SIP in renal cell carcinoma still remain unclear. In the present study, we had analyzed the expression of the CacyBP/SIP protein in human renal cancer cells and clinical tissue samples. The possible roles of CacyBP/SIP in regulating the malignant phenotype of renal cancer cells were also investigated. The results demonstrated that the expression of CacyBP/SIP was markedly down-regulated in renal cell carcinoma tissues and cell lines. Ectopic overexpression of CacyBP/SIP in A498 cells inhibited the proliferation of this cell and delayed cell cycle progression significantly, which might be related to the down-regulation of Cyclin D1 through reducing {beta}-catenin protein. CacyBP/SIP also suppressed colony formation in soft agar and its tumorigenicity in nude mice. Taken together, our work showed that CacyBP/SIP, as a novel down-regulated gene in renal cell carcinoma, suppressed proliferation and tumorigenesis of renal cancer cells.

  6. 75 FR 65309 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ..., and mitigate the impact of, any oil spills associated with offshore drilling in the future. The... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling AGENCY: Department of... meeting of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling...

  7. 75 FR 37783 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... spill and develop options to guard against, and mitigate the impact of, any oil spills associated with... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling AGENCY: Department of... meeting of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling...

  8. 75 FR 47584 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ..., and mitigate the impact of, any oil spills associated with offshore drilling in the future. The... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling AGENCY: Department of... meeting for the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling...

  9. 75 FR 39518 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ..., 2010, of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, (75 FR... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling; Correction AGENCY: Office...: Christopher A. Smith, (202) 586-0716. Corrections In the Federal Register of June 30, 2010, in FR Doc....

  10. 75 FR 68607 - BP Canada Energy Marketing Corp. Apache Corporation; Notice for Temporary Waivers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission BP Canada Energy Marketing Corp. Apache Corporation; Notice for Temporary Waivers November 1, 2010. Take notice that on October 29, 2010, BP Canada Energy Marketing Corp....

  11. E4BP4: an unexpected player in the immune response.

    PubMed

    Male, Victoria; Nisoli, Ilaria; Gascoyne, Duncan M; Brady, Hugh J M

    2012-02-01

    Until recently, the basic leucine zipper transcription factor E4BP4 (also known as NFIL3) was of little interest to immunologists, being best known for its role in regulating circadian rhythm in chick pineal gland. However, characterisation of E4bp4(-/-) mice, independently generated in four different laboratories, has revealed roles for E4BP4 in diverse haematopoietic lineages. E4BP4 is essential for the development of NK cells and CD8α(+) conventional dendritic cells, and is also involved in macrophage activation, polarisation of CD4(+) T cell responses and B cell class switching to IgE. Here, we discuss the role of E4BP4 as a regulator of the immune response and highlight future questions for the field. PMID:22075207

  12. The adaptor 3BP2 is required for KIT receptor expression and human mast cell survival

    PubMed Central

    Ainsua-Enrich, Erola; Serrano-Candelas, Eva; Álvarez-Errico, Damiana; Picado, César; Sayós, Joan; Rivera, Juan; Martín, Margarita

    2015-01-01

    3BP2 is a cytoplasmic adaptor protein that acts as a positive regulator in mast cell FcεRI-dependent signaling. The KIT receptor whose ligand is the stem cell factor (SCF) is necessary for mast cell development, proliferation and survival as well as for optimal IgE-dependent signal. Activating mutations in KIT have been associated with several diseases including mastocytosis. In the present work, we found that 3BP2 silencing impairs KIT signaling pathways, thus affecting PI3K and MAP kinase pathways in human mast cells from HMC-1, LAD2 (human mast cell lines) and CD34+-derived mast cells. Unexpectedly, silencing of 3BP2 reduces KIT expression in normal human mast cells as well as in HMC-1 cells where KIT is mutated, thus increasing cellular apoptosis and caspase 3/7 activity. 3BP2 silencing reduces KIT transcription expression levels. Interestingly, 3BP2 silencing decreased MITF expression, a transcription factor involved in KIT expression. Reconstitution of 3BP2 in knockdown cells leads to reversal of KIT expression as well as survival phenotype. Accordingly MITF reconstitution enhances KIT expression levels in 3BP2 silenced cells. Moreover, downregulation of KIT expression by miRNA221 overexpression or the proteasome inhibitor bortezomib also reduced 3BP2 and MITF expression. Furthermore, KIT tyrosine activity inhibition reduced 3BP2 and MITF expression, demonstrating again a tight and reciprocal relationship between these molecules. Taken together, our results show that 3BP2 regulates human mast cell survival and participates in KIT-mediated signal transduction by directly controlling KIT receptor expression, suggesting its potential as a therapeutic target in mast cell-mediated inflammatory diseases and deregulated KIT disorders. PMID:25810396

  13. RanBP9 at the intersection between cofilin and Aβ pathologies: rescue of neurodegenerative changes by RanBP9 reduction

    PubMed Central

    Woo, J A; Boggess, T; Uhlar, C; Wang, X; Khan, H; Cappos, G; Joly-Amado, A; De Narvaez, E; Majid, S; Minamide, L S; Bamburg, J R; Morgan, D; Weeber, E; Kang, D E

    2015-01-01

    Molecular pathways underlying the neurotoxicity and production of amyloid β protein (Aβ) represent potentially promising therapeutic targets for Alzheimer's disease (AD). We recently found that overexpression of the scaffolding protein RanBP9 increases Aβ production in cell lines and in transgenic mice while promoting cofilin activation and mitochondrial dysfunction. Translocation of cofilin to mitochondria and induction of cofilin–actin pathology require the activation/dephosphorylation of cofilin by Slingshot homolog 1 (SSH1) and cysteine oxidation of cofilin. In this study, we found that endogenous RanBP9 positively regulates SSH1 levels and mediates Aβ-induced translocation of cofilin to mitochondria and induction of cofilin–actin pathology in cultured cells, primary neurons, and in vivo. Endogenous level of RanBP9 was also required for Aβ-induced collapse of growth cones in immature neurons (days in vitro 9 (DIV9)) and depletion of synaptic proteins in mature neurons (DIV21). In vivo, amyloid precursor protein (APP)/presenilin-1 (PS1) mice exhibited 3.5-fold increased RanBP9 levels, and RanBP9 reduction protected against cofilin–actin pathology, synaptic damage, gliosis, and Aβ accumulation associated with APP/PS1 mice. Brains slices derived from APP/PS1 mice showed significantly impaired long-term potentiation (LTP), and RanBP9 reduction significantly enhanced paired pulse facilitation and LTP, as well as partially rescued contextual memory deficits associated with APP/PS1 mice. Therefore, these results underscore the critical importance of endogenous RanBP9 not only in Aβ accumulation but also in mediating the neurotoxic actions of Aβ at the level of synaptic plasticity, mitochondria, and cofilin–actin pathology via control of the SSH1-cofilin pathway in vivo. PMID:25741591

  14. Oncofetal protein IGF2BP3 facilitates the activity of proto-oncogene protein eIF4E through the destabilization of EIF4E-BP2 mRNA.

    PubMed

    Mizutani, R; Imamachi, N; Suzuki, Y; Yoshida, H; Tochigi, N; Oonishi, T; Suzuki, Y; Akimitsu, N

    2016-07-01

    RNA-binding proteins (RBPs) have important roles in tumorigenesis. Although IGF2BP3, an evolutionally conserved RBP, has been reported as a useful diagnostic marker for various cancers and has been considered a regulator of tumorigenesis, little is known of the function of IGF2BP3 because of lack of information regarding IGF2BP3 target mRNAs. Here, we report the identification of IGF2BP3 target mRNAs and IGF2BP3 function in cancer proliferation. We identified mRNAs with altered expression in IGF2BP3-depleted cells by massive sequencing analysis and IGF2BP3-binding RNAs by immunoprecipitation of IGF2BP3 followed by massive sequencing analysis, resulting in the identification of 110 candidates that are negatively regulated by IGF2BP3. We found that IGF2BP3 destabilized EIF4E-BP2 and MEIS3 mRNAs. Co-immunoprecipitation analysis revealed the interaction between IGF2BP3 and ribonucleases such as XRN2 and exosome component. The retarded proliferation of IGF2BP3-depleted cells was partially rescued by the depletion of EIF4E-BP2, which negatively regulates eukaryotic translation initiation factor 4E (eIF4E), an activator of translation and a well-known proto-oncogene. Consistent with this observation, IGF2BP3 depletion reduced phosphorylated eIF4E, the active form, and translational efficiency of eIF4E target transcripts. Reduction of phosphorylated eIF4E by IGF2BP3 depletion was rescued by EIF4E-BP2 depletion. At last, we found an inverse correlation between the expression level of IGF2BP3 and EIF4E-BP2 in human lung adenocarcinoma tissues. Together, these results suggest that IGF2BP3 promotes eIF4E-mediated translational activation through the reduction of EIF4E-BP2 via mRNA degradation, leading to enhanced cell proliferation. This is the first report demonstrating that IGF2BP3 is an RNA-destabilizing factor. Notably, here we provide the first evidence for the functional linkage between two previously well-known cancer biomarkers, IGF2BP3 and eIF4E. PMID:26522719

  15. The determination of potential energy curve and dipole moment of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule by high resolution photoassociation spectroscopy

    SciTech Connect

    Yuan, Jinpeng; Zhao, Yanting Ji, Zhonghua; Li, Zhonghao; Xiao, Liantuan; Jia, Suotang; Kim, Jin-Tae

    2015-12-14

    We present the formation of ultracold {sup 85}Rb{sup 133}Cs molecules in the (5)0{sup +} electronic state by photoassociation and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 vibrational and lowest J = 0 levels are identified with rotationally resolved high resolution photoassociation spectra. Precise Dunham coefficients are determined for the (5)0{sup +} state with high accuracy, then the Rydberg-Klein-Rees potential energy curve is derived. The electric dipole moments with respect to the vibrational numbers of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule are also measured in the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5)0{sup +} state are helpful to understand the molecular structure and discover suitable transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state.

  16. SimTracker, Version 5.0

    SciTech Connect

    2004-08-27

    SimTracker is a product of the Metadata Tools subproject under the ASC Scientific Data Management effort. SimTracker is an extensible web-based application that provides the capability to view and organize large volumes of simulation data. SimTracker automatically generates metadata summaries that provide a quick overview and index to the archived results of simulations. The summaries provide access to the data sets and associated data analysis tools. They include graphical snapshots, pointers to associated simulation input and output files, and assorted annotations. The ability to add personal annotations to simulation data sets is supported. All metadata is stored in XML files suitable for searching by the generator of the data or other scientists.

  17. Asteroid Polarimetric Database V5.0

    NASA Astrophysics Data System (ADS)

    Lupishko, D.

    2006-07-01

    The Asteroid Polarimetric Database (APD) is a collection of asteroid polarimetry results compiled by D.F. Lupishko of Karazin Kharkiv National University, Ukraine. It is intended to include most asteroid polarimetry available through March 21, 2006.

  18. Binary Minor Planets V5.0

    NASA Astrophysics Data System (ADS)

    Johnston, W. R.

    2012-06-01

    The data set lists orbital and physical properties for well-observed or suspected binary/multiple minor planets including the Pluto system, as inspired by Richardson and Walsh (2006) and similar reviews (Merline et al., 2003; Noll, 2006; Pravec et al., 2006; Pravec and Harris, 2007; Descamps and Marchis, 2008; Noll et al., 2008; Walsh, 2009). In total 218 companions in 206 systems are included. Data are presented in two tables, one for orbital and physical properties and one for companion designations, discovery information, and reference codes for data values. Data are ordered by permanent number, then provisional designation. This data set is complete for binary/multiple components reported through 31 March 2012.

  19. SimTracker, Version 5.0

    2004-08-27

    SimTracker is a product of the Metadata Tools subproject under the ASC Scientific Data Management effort. SimTracker is an extensible web-based application that provides the capability to view and organize large volumes of simulation data. SimTracker automatically generates metadata summaries that provide a quick overview and index to the archived results of simulations. The summaries provide access to the data sets and associated data analysis tools. They include graphical snapshots, pointers to associated simulation inputmore » and output files, and assorted annotations. The ability to add personal annotations to simulation data sets is supported. All metadata is stored in XML files suitable for searching by the generator of the data or other scientists.« less

  20. RREL TREATABILITY DATABASE - VERSION 5.0

    EPA Science Inventory

    There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. This database can be obtained by contacting Tom Holdsworth, U.S. EPA, 26 West Martin Luther King D...

  1. CacyBP/SIP nuclear translocation regulates p27Kip1 stability in gastric cancer cells

    PubMed Central

    Niu, Ying-Lin; Li, Ya-Jun; Wang, Jing-Bo; Lu, Yuan-Yuan; Liu, Zhen-Xiong; Feng, Shan-Shan; Hu, Jian-Guo; Zhai, Hui-Hong

    2016-01-01

    AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein (CacyBP/SIP) nuclear translocation in promoting the proliferation of gastric cancer (GC) cells. METHODS: The effect of CacyBP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Co-immunoprecipitation (co-IP) analysis was performed to examine the binding of CacyBP/SIP with Skp1. A CacyBP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1 protein expression assessed by Western blot analysis. RESULTS: CacyBP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while CacyBP/SIP nuclear translocation was inhibited using siRNA to suppress CacyBP/SIP expression, cell cycle was clearly inhibited. CacyBP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of CacyBP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, CacyBP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant CacyBP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus. CONCLUSION: CacyBP/SIP nuclear translocation contributes to the proliferation of GC cells, and CacyBP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27

  2. In vitro short-term exposure to air pollution PM2.5-0.3 induced cell cycle alterations and genetic instability in a human lung cell coculture model.

    PubMed

    Abbas, Imane; Verdin, Anthony; Escande, Fabienne; Saint-Georges, Françoise; Cazier, Fabrice; Mulliez, Philippe; Courcot, Dominique; Shirali, Pirouz; Gosset, Pierre; Garçon, Guillaume

    2016-05-01

    Although its adverse health effects of air pollution particulate matter (PM2.5) are well-documented and often related to oxidative stress and pro-inflammatory response, recent evidence support the role of the remodeling of the airway epithelium involving the regulation of cell death processes. Hence, the overarching goals of the present study were to use an in vitro coculture model, based on human AM and L132 cells to study the possible alteration of TP53-RB gene signaling pathways (i.e. cell cycle phases, gene expression of TP53, BCL2, BAX, P21, CCND1, and RB, and protein concentrations of their active forms), and genetic instability (i.e. LOH and/or MSI) in the PM2.5-0.3-exposed coculture model. PM2.5-0.3 exposure of human AM from the coculture model induced marked cell cycle alterations after 24h, as shown by increased numbers of L132 cells in subG1 and S+G2 cell cycle phases, indicating apoptosis and proliferation. Accordingly, activation of the TP53-RB gene signaling pathways after the coculture model exposure to PM2.5-0.3 was reported in the L132 cells. Exposure of human AM from the coculture model to PM2.5-0.3 resulted in MS alterations in 3p chromosome multiple critical regions in L132 cell population. Hence, in vitro short-term exposure of the coculture model to PM2.5-0.3 induced cell cycle alterations relying on the sequential occurrence of molecular abnormalities from TP53-RB gene signaling pathway activation and genetic instability. PMID:26874047

  3. Characterization of a cancer cell line that expresses a splicing variant form of 53BP1: Separation of checkpoint and repair functions in 53BP1

    SciTech Connect

    Iwabuchi, Kuniyoshi Matsui, Tadashi; Hashimoto, Mitsumasa; Matsumoto, Yoshihisa; Kurihara, Takayuki; Date, Takayasu

    2008-11-21

    53BP1 plays important roles in checkpoint signaling and repair for DNA double-strand breaks. We found that a colon cancer cell line, SW48, expressed a splicing variant form of 53BP1, which lacks the residues corresponding to exons 10 and 11. Activation of ATM and phosphorylation of ATM and ATR targets occurred in SW48 cells in response to X-irradiation, and these X-ray-induced responses were not enhanced by expression of full-length 53BP1 in SW48 cells, indicating that this splicing variant fully activates the major checkpoint signaling in SW48 cells. In contrast, the expression of full-length 53BP1 in SW48 cells promoted the repair of X-ray-induced DNA damage, evidenced by faster disappearance of X-ray-induced {gamma}-H2AX foci, a marker for DNA damage, and less residual chromosomal aberrations after X-irradiation. We conclude that the two major roles of 53BP1, the checkpoint signaling and repair for DNA damage, can be functionally separated.

  4. Subepidermal Blistering Induced by Human Autoantibodies to BP180 Requires Innate Immune Players in a Humanized Bullous Pemphigoid Mouse Model

    PubMed Central

    Liu, Zhi; Sui, Wen; Zhao, Minglang; Li, Zhuowei; Li, Ning; Thresher, Randy; Giudice, George J.; Fairley, Janet A.; Sitaru, Cassian; Zillikens, Detlef; Ning, Gang; Marinkovich, Peter; Diaz, Luis A.

    2008-01-01

    Bullous pemphigoid (BP) is a cutaneous autoimmune inflammatory disease associated with subepidermal blistering and autoantibodies against BP180, a transmembrane collagen and major component of the hemidesmosome. Numerous inflammatory cells infiltrate the upper dermis in BP. IgG autoantibodies in BP fix complement and target multiple BP180 epitopes that are highly clustered within a non-collagen linker domain, termed NC16A. Anti-BP180 antibodies induce BP in mice. In this study, we generated a humanized mouse strain, in which the murine BP180NC14A is replaced with the homologous human BP180NC16A epitope cluster region. We show that the humanized NC16A (NC16A+/+) mice injected with anti-BP180NC16A autoantibodies develop BP-like subepidermal blisters. The F(ab′)2 fragments of pathogenic IgG fail to activate complement cascade and are no longer pathogenic. The NC16A+/+ mice pretreated with mast cell activation blocker or depleting of complement or neutrophils become resistant to BP. These findings suggest that the humoral response in BP critically depends on innate immune system players. PMID:18922680

  5. Speed and Magnitude of Abrupt Climate Change at 8,200 yrs B.P. from the Greenland Ice Core (GISP2)

    NASA Astrophysics Data System (ADS)

    Kobashi, T.; Severinghaus, J. P.; Brook, E. J.; Grachev, A.

    2003-12-01

    At ˜8,200 years before present, an abrupt climate change occurred, which is believed to be the largest in the past 10,000 years. The scale of the event was probably global, as seen in reduced atmospheric methane concentration and paleoclimatic evidence around the globe indicating drying and cooling trends. The timing of the climate change also coincides with widespread abandonment of villages in southwestern Asia, which marks the end of the Pre-Pottery Neolithic B (PPNB) interval. Owing to the similarity between the warm early-Holocene and the projected warmer future climate, the 8.2 k event provides us an invaluable test case for a future potential abrupt climate change. We reconstructed the speed and magnitude of temperature change at the event, using argon and nitrogen isotopes in trapped air from the Greenland ice core coupled with the oxygen isotope record of ice. This method makes use of two isotopic fractionations, gravitational and thermal, which occur within the firn layer (snow layer above the air bubble close-off depth). The analyses of argon and nitrogen isotopes can separate the two effects, and allows us to directly retrieve temperature information (Severinghaus et al., Nature, v. 391, 141, 1998). The magnitude of temperature change in central Greenland at 8.2kyr B.P. is preliminarily estimated to be 5 +/- 2 ° C for the decadal average with the experimentally determined thermal diffusion constants (Grachev and Severinghaus, Geochim. et Cosmochim. Acta, v.67, 345, 2003; J. Phys. Chem., v.107, 4636, 2003), implying an oxygen isotope-temperature coefficient, α , of ˜0.4 permil/° C. Using oxygen isotope record of ice and α , we estimate that the abrupt cooling took place within ˜5 years with an 'instantaneous' magnitude of ˜8° C, and climate was locked in the cold phase for ˜60 years. In addition, we plan to measure methane concentration in trapped air, which will constrain the mechanisms of the abrupt climate change.

  6. Establishing a Dynamic Self-Adaptation Learning Algorithm of the BP Neural Network and Its Applications

    NASA Astrophysics Data System (ADS)

    Li, Xiaofeng; Xiang, Suying; Zhu, Pengfei; Wu, Min

    2015-12-01

    In order to avoid the inherent deficiencies of the traditional BP neural network, such as slow convergence speed, that easily leading to local minima, poor generalization ability and difficulty in determining the network structure, the dynamic self-adaptive learning algorithm of the BP neural network is put forward to improve the function of the BP neural network. The new algorithm combines the merit of principal component analysis, particle swarm optimization, correlation analysis and self-adaptive model, hence can effectively solve the problems of selecting structural parameters, initial connection weights and thresholds and learning rates of the BP neural network. This new algorithm not only reduces the human intervention, optimizes the topological structures of BP neural networks and improves the network generalization ability, but also accelerates the convergence speed of a network, avoids trapping into local minima, and enhances network adaptation ability and prediction ability. The dynamic self-adaptive learning algorithm of the BP neural network is used to forecast the total retail sale of consumer goods of Sichuan Province, China. Empirical results indicate that the new algorithm is superior to the traditional BP network algorithm in predicting accuracy and time consumption, which shows the feasibility and effectiveness of the new algorithm.

  7. YB-1 regulates stress granule formation and tumor progression by translationally activating G3BP1

    PubMed Central

    Somasekharan, Syam Prakash; El-Naggar, Amal; Leprivier, Gabriel; Cheng, Hongwei; Hajee, Shamil; Grunewald, Thomas G.P.; Zhang, Fan; Ng, Tony; Delattre, Olivier; Evdokimova, Valentina; Wang, Yuzhuo; Gleave, Martin

    2015-01-01

    Under cell stress, global protein synthesis is inhibited to preserve energy. One mechanism is to sequester and silence mRNAs in ribonucleoprotein complexes known as stress granules (SGs), which contain translationally silent mRNAs, preinitiation factors, and RNA-binding proteins. Y-box binding protein 1 (YB-1) localizes to SGs, but its role in SG biology is unknown. We now report that YB-1 directly binds to and translationally activates the 5′ untranslated region (UTR) of G3BP1 mRNAs, thereby controlling the availability of the G3BP1 SG nucleator for SG assembly. YB-1 inactivation in human sarcoma cells dramatically reduces G3BP1 and SG formation in vitro. YB-1 and G3BP1 expression are highly correlated in human sarcomas, and elevated G3BP1 expression correlates with poor survival. Finally, G3BP1 down-regulation in sarcoma xenografts prevents in vivo SG formation and tumor invasion, and completely blocks lung metastasis in mouse models. Together, these findings demonstrate a critical role for YB-1 in SG formation through translational activation of G3BP1, and highlight novel functions for SGs in tumor progression. PMID:25800057

  8. Cell cycle-dependent inhibition of 53BP1 signaling by BRCA1

    PubMed Central

    Feng, Lin; Li, Nan; Li, Yujing; Wang, Jiadong; Gao, Min; Wang, Wenqi; Chen, Junjie

    2015-01-01

    DNA damage response mediator protein 53BP1 is a key regulator of non-homologous end-joining (NHEJ) repair. 53BP1 protects DNA broken ends from resection by recruiting two downstream factors, RIF1 (RAP1-interacting factor 1) and PTIP (Pax transactivation domain-interacting protein), to double-stranded breaks (DSBs) via ATM (ataxia telangiectasia mutated)-mediated 53BP1 phosphorylation, and competes with BRCA1-mediated homologous recombination (HR) repair in G1 phase. In contrast, BRCA1 antagonizes 53BP1-direct NHEJ repair in S/G2 phases. We and others have found that BRCA1 prevents the translocation of RIF1 to DSBs in S/G2 phases; however, the underlying mechanism remains unclear. Here we show that efficient ATM-dependent 53BP1 phosphorylation is restricted to the G1 phase of the cell cycle, as a consequence RIF1 and PTIP accumulation at DSB sites only occur in G1 phase. Mechanistically, both BRCT and RING domains of BRCA1 are required for the inhibition of 53BP1 phosphorylation in S and G2 phases. Thus, our findings reveal how BRCA1 antagonizes 53BP1 signaling to ensure that HR repair is the dominant repair pathway in S/G2 phases.

  9. CENP-C facilitates the recruitment of M18BP1 to centromeric chromatin.

    PubMed

    Dambacher, Silvia; Deng, Wen; Hahn, Matthias; Sadic, Dennis; Fröhlich, Jonathan; Nuber, Alexander; Hoischen, Christian; Diekmann, Stephan; Leonhardt, Heinrich; Schotta, Gunnar

    2012-01-01

    Centromeres are important structural constituents of chromosomes that ensure proper chromosome segregation during mitosis by providing defined sites for kinetochore attachment. In higher eukaryotes, centromeres have no specific DNA sequence and thus, they are rather determined through epigenetic mechanisms. A fundamental process in centromere establishment is the incorporation of the histone variant CENP-A into centromeric chromatin, which provides a binding platform for the other centromeric proteins. The Mis18 complex, and, in particular, its member M18BP1 was shown to be essential for both incorporation and maintenance of CENP-A. Here we show that M18BP1 displays a cell cycle-regulated association with centromeric chromatin in mouse embryonic stem cells. M18BP1 is highly enriched at centromeric regions from late anaphase through to G1 phase. An interaction screen against 16 core centromeric proteins revealed a novel interaction of M18BP1 with CENP-C. We mapped the interaction domain in M18BP1 to a central region containing a conserved SANT domain and in CENP-C to the C-terminus. Knock-down of CENP-C leads to reduced M18BP1 association and lower CENP-A levels at centromeres, suggesting that CENP-C works as an important factor for centromeric M18BP1 recruitment and thus for maintaining centromeric CENP-A. PMID:22540025

  10. CENP-C facilitates the recruitment of M18BP1 to centromeric chromatin

    PubMed Central

    Dambacher, Silvia; Deng, Wen; Hahn, Matthias; Sadic, Dennis; Fröhlich, Jonathan; Nuber, Alexander; Hoischen, Christian; Diekmann, Stephan; Leonhardt, Heinrich; Schotta, Gunnar

    2012-01-01

    Centromeres are important structural constituents of chromosomes that ensure proper chromosome segregation during mitosis by providing defined sites for kinetochore attachment. In higher eukaryotes, centromeres have no specific DNA sequence and thus, they are rather determined through epigenetic mechanisms. A fundamental process in centromere establishment is the incorporation of the histone variant CENP-A into centromeric chromatin, which provides a binding platform for the other centromeric proteins. The Mis18 complex, and, in particular, its member M18BP1 was shown to be essential for both incorporation and maintenance of CENP-A.   Here we show that M18BP1 displays a cell cycle-regulated association with centromeric chromatin in mouse embryonic stem cells. M18BP1 is highly enriched at centromeric regions from late anaphase through to G1 phase. An interaction screen against 16 core centromeric proteins revealed a novel interaction of M18BP1 with CENP-C. We mapped the interaction domain in M18BP1 to a central region containing a conserved SANT domain and in CENP-C to the C-terminus. Knock-down of CENP-C leads to reduced M18BP1 association and lower CENP-A levels at centromeres, suggesting that CENP-C works as an important factor for centromeric M18BP1 recruitment and thus for maintaining centromeric CENP-A. PMID:22540025

  11. Divergent homologs of the predicted small RNA BpCand697 in Burkholderia spp.

    NASA Astrophysics Data System (ADS)

    Damiri, Nadzirah; Mohd-Padil, Hirzahida; Firdaus-Raih, Mohd

    2015-09-01

    The small RNA (sRNA) gene candidate, BpCand697 was previously reported to be unique to Burkholderia spp. and is encoded at 3' non-coding region of a putative AraC family transcription regulator gene. This study demonstrates the conservation of BpCand697 sequence across 32 Burkholderia spp. including B. pseudomallei, B. mallei, B. thailandensis and Burkholderia sp. by integrating both sequence homology and secondary structural analyses of BpCand697 within the dataset. The divergent sequence of BpCand697 was also used as a discriminatory power in clustering the dataset according to the potential virulence of Burkholderia spp., showing that B. thailandensis was clearly secluded from the virulent cluster of B. pseudomallei and B. mallei. Finally, the differential co-transcript expression of BpCand697 and its flanking gene, bpsl2391 was detected in Burkholderia pseudomallei D286 after grown under two different culture conditions using nutrient-rich and minimal media. It is hypothesized that the differential expression of BpCand697-bpsl2391 co-transcript between the two standard prepared media might correlate with nutrient availability in the culture media, suggesting that the physical co-localization of BpCand697 in B. pseudomallei D286 might be directly or indirectly involved with the transcript regulation of bpsl2391 under the selected in vitro culture conditions.

  12. Levels of the E2 interacting protein TopBP1 modulate papillomavirus maintenance stage replication.

    PubMed

    Kanginakudru, Sriramana; DeSmet, Marsha; Thomas, Yanique; Morgan, Iain M; Androphy, Elliot J

    2015-04-01

    The evolutionarily conserved DNA topoisomerase II beta-binding protein 1 (TopBP1) functions in DNA replication, DNA damage response, and cell survival. We analyzed the role of TopBP1 in human and bovine papillomavirus genome replication. Consistent with prior reports, TopBP1 co-localized in discrete nuclear foci and was in complex with papillomavirus E2 protein. Similar to E2, TopBP1 is recruited to the region of the viral origin of replication during G1/S and early S phase. TopBP1 knockdown increased, while over-expression decreased transient virus replication, without affecting cell cycle. Similarly, using cell lines harboring HPV-16 or HPV-31 genome, TopBP1 knockdown increased while over-expression reduced viral copy number relative to genomic DNA. We propose a model in which TopBP1 serves dual roles in viral replication: it is essential for initiation of replication yet it restricts viral copy number. PMID:25666521

  13. M2BP inhibits HIV-1 virion production in a vimentin filaments-dependent manner

    PubMed Central

    Wang, Qin; Zhang, Xiaolin; Han, Yuling; Wang, Xinlu; Gao, Guangxia

    2016-01-01

    M2BP (also called 90K) is an interferon-stimulated gene product that is upregulated in HIV-1 infection. A recent study revealed that M2BP reduces the infectivity of HIV-1 by inhibiting the processing of the viral envelope protein. Here we report that in addition to reducing viral infectivity, M2BP inhibits HIV-1 virion production. We provide evidence showing that M2BP inhibits HIV-1 Gag trafficking to the plasma membrane in a vimentin-dependent manner. When vimentin filaments were collapsed by treating cells with acrylamide or by overexpression of a dominant-negative mutant of vimentin, M2BP inhibition of HIV-1 virion production was significantly relieved. We further show that M2BP interacts with both HIV-1 Gag and vimentin and thereby mediates their interactions. We propose that M2BP traps HIV-1 Gag to vimentin filaments to inhibit the transportation of HIV-1 Gag to the plasma membrane. These findings uncover a novel mechanism by which a host antiviral factor inhibits HIV-1 virion production. PMID:27604950

  14. M2BP inhibits HIV-1 virion production in a vimentin filaments-dependent manner.

    PubMed

    Wang, Qin; Zhang, Xiaolin; Han, Yuling; Wang, Xinlu; Gao, Guangxia

    2016-01-01

    M2BP (also called 90K) is an interferon-stimulated gene product that is upregulated in HIV-1 infection. A recent study revealed that M2BP reduces the infectivity of HIV-1 by inhibiting the processing of the viral envelope protein. Here we report that in addition to reducing viral infectivity, M2BP inhibits HIV-1 virion production. We provide evidence showing that M2BP inhibits HIV-1 Gag trafficking to the plasma membrane in a vimentin-dependent manner. When vimentin filaments were collapsed by treating cells with acrylamide or by overexpression of a dominant-negative mutant of vimentin, M2BP inhibition of HIV-1 virion production was significantly relieved. We further show that M2BP interacts with both HIV-1 Gag and vimentin and thereby mediates their interactions. We propose that M2BP traps HIV-1 Gag to vimentin filaments to inhibit the transportation of HIV-1 Gag to the plasma membrane. These findings uncover a novel mechanism by which a host antiviral factor inhibits HIV-1 virion production. PMID:27604950

  15. E4BP4 overexpression: a protective mechanism in CD4+ T cells from SLE patients.

    PubMed

    Zhao, Ming; Liu, Qian; Liang, Gongping; Wang, Litao; Luo, Shuangyan; Tang, Qian; Zhao, Hongjun; Su, Yuwen; Yung, Susan; Chan, Tak Mao; Lu, Qianjin

    2013-03-01

    Systemic lupus erythematosus (SLE) is a prototype autoimmune disease characterized by various immunological abnormalities, including dysregulated activation of T and B lymphocytes, which trigger autoantibody production and immune-complex deposition. E4BP4, also known as NFIL3, has emerged as a major transcription factor that regulates the development and function of immune cells in a number of lineages. E4BP4 has been shown to regulate cytokines expression, and its synthesis is in turn controlled by various cytokines. To date, the roles of E4BP4 in immune dysregulation and autoimmune disorders are unclear. In this study, we demonstrated that E4BP4 expression is increased in CD4(+) T cells isolated from patients with active systemic lupus erythematosus (SLE), especially in patients treated with glucocorticoid (GC). Increased expression of E4BP4 inhibited the activation and self-reactivity of T cells stimulated by anti-CD3/CD28 antibodies. In contrast, the self-reactivity was enhanced in CD4(+) T cells from SLE patients following E4BP4 gene silencing and the production of autoantibody was increased in autologous B cells. We further demonstrated that E4BP4 directly regulated CD40L expression by binding to the promoter region and altering histone acetylation and methylation of the CD40L loci. Taken together, our data provide evidence that E4BP4 can inhibit CD40L expression through epigenetic modifications in the promoter region of CD40L, thus negatively regulating self-reactivity of SLE CD4(+) T cells. Furthermore, our data demonstrate that overexpression of E4BP4 initiates a protective mechanism in SLE CD4(+) T cells, which may be a promising target in the therapy for SLE. PMID:23340290

  16. Mutation particle swarm optimization of the BP-PID controller for piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Zheng, Huaqing; Jiang, Minlan

    2016-01-01

    PID control is the most common used method in industrial control because its structure is simple and it is easy to implement. PID controller has good control effect, now it has been widely used. However, PID method has a few limitations. The overshoot of the PID controller is very big. The adjustment time is long. When the parameters of controlled plant are changing over time, the parameters of controller could hardly change automatically to adjust to changing environment. Thus, it can't meet the demand of control quality in the process of controlling piezoelectric ceramic. In order to effectively control the piezoelectric ceramic and improve the control accuracy, this paper replaced the learning algorithm of the BP with the mutation particle swarm optimization algorithm(MPSO) on the process of the parameters setting of BP-PID. That designed a better self-adaptive controller which is combing the BP neural network based on mutation particle swarm optimization with the conventional PID control theory. This combination is called the MPSO-BP-PID. In the mechanism of the MPSO, the mutation operation is carried out with the fitness variance and the global best fitness value as the standard. That can overcome the precocious of the PSO and strengthen its global search ability. As a result, the MPSO-BP-PID can complete controlling the controlled plant with higher speed and accuracy. Therefore, the MPSO-BP-PID is applied to the piezoelectric ceramic. It can effectively overcome the hysteresis, nonlinearity of the piezoelectric ceramic. In the experiment, compared with BP-PID and PSO-BP-PID, it proved that MPSO is effective and the MPSO-BP-PID has stronger adaptability and robustness.

  17. Change in the Nd isotopic composition of the bottom water and detrital sediments on the Bering Slope over the last 500 kyrs with implications for the formation of the North Pacific Intermediate Water

    NASA Astrophysics Data System (ADS)

    Jang, K.; Huh, Y.; Han, Y.

    2015-12-01

    The Bering Sea is a potential location for the formation of the North Pacific Intermediate/Deep Water (NPIW/NPDW) and may play an important role in the global heat distribution. We reconstructed the neodymium isotopic ratio (ɛNd) of authigenic Fe-Mn oxide coatings and detrital sediments on the Bering Slope (IODP Expedition 323 site U1345; water depth 1008 m) over the last 500 kyrs. The ɛNd is a quasi-conservative water mass tracer. We compared three different leaching techniques to assure that authigenic signals are captured without contamination from terrigenous sources: (1) leaching (3 hours) with 0.02 M hydroxylamine hydrochloride (HH) in 25% buffered acetic acid after decarbonation; sediment/solution (v/v) > 10, (2) leaching (1 hour) with 0.02 M HH in 25% buffered acetic acid without decarbonation; sediment/solution ~ 1, and (3) leaching (1 hour) with 0.005 M HH in 1.5% buffered acetic acid-0.003 M Na-EDTA without decarbonation; sediment/solution > 40. The low Al concentrations and less radiogenic ɛNdvalues indicated that method (2) is the most appropriate leaching process. The average ɛNd of the authigenic fraction over the last 500 kyrs is -3.3 ± 0.9 (1σ, n=38), with large temporal fluctuations. The ɛNd of authigenic and detrital fractions are well correlated (r2 ~ 0.66), suggesting that the bottom water composition in the Bering Sea was governed by terrigenous inflow from surrounding areas. Radiogenic ɛNd peaks (up to -1.9) seem to be influenced by radiogenic water inflow from the the Kamchatka or Aluetian arcs. The high bulk density and low b* values imply higher terrigenous versus biological contribution and enhanced sea ice formation. Subsequent brine formation would have triggered sinking of radiogenic surface water, forming the NPIW. On the other hand, non-radiogenic ɛNd troughs (down to -5.3) are observed at times of low bulk density and high b* values. We presume higher biological productivity which is supported by the high opal content at

  18. Two Isoforms of the RNA Binding Protein, Coding Region Determinant-binding Protein (CRD-BP/IGF2BP1), Are Expressed in Breast Epithelium and Support Clonogenic Growth of Breast Tumor Cells*

    PubMed Central

    Fakhraldeen, Saja A.; Clark, Rod J.; Roopra, Avtar; Chin, Emily N.; Huang, Wei; Castorino, John; Wisinski, Kari B.; Kim, TaeWon; Spiegelman, Vladimir S.; Alexander, Caroline M.

    2015-01-01

    CRD-BP/IGF2BP1 has been characterized as an “oncofetal” RNA binding protein typically highly expressed in embryonic tissues, suppressed in normal adult tissues, but induced in many tumor types. In this study, we show that adult breast tissues express ubiquitous but low levels of CRD-BP protein and mRNA. Although CRD-BP mRNA expression is induced in breast tumor cells, levels remain ∼1000-fold lower than in embryonic tissues. Despite low expression levels, CRD-BP is required for clonogenic growth of breast cancer cells. We reveal that because the most common protein isoform in normal adult breast and breast tumors has an N-terminal deletion (lacking two RNA recognition motif (RRM) domains) and is therefore missing antibody epitopes, CRD-BP expression has been under-reported by previous studies. We show that a CRD-BP mutant mouse strain retains expression of the shorter transcript (ΔN-CRD-BP), which originates in intron 2, suggesting that the impact of complete ablation of this gene in mice is not yet known. Either the full-length CRD-BP or the N-terminally truncated version can rescue the clonogenicity of CRD-BP knockdown breast cancer cells, suggesting that clonogenic function is served by either CRD-BP isoform. In summary, although CRD-BP expression levels are low in breast cancer cells, this protein is necessary for clonogenic activity. PMID:25861986

  19. Clinical and Immunological Studies of 332 Japanese Patients Tentatively Diagnosed as Anti-BP180-type Mucous Membrane Pemphigoid: A Novel BP180 C-terminal Domain Enzyme-linked Immunosorbent Assay.

    PubMed

    Yasukochi, Atsushi; Teye, Kwesi; Ishii, Norito; Hashimoto, Takashi

    2016-08-23

    Diagnosis of anti-BP180-type mucous membrane pemphigoid (BP180-MMP) is frustrated by the difficulty of detecting BP180 reactivity. A total of 721 patients with suspected MMP, selected from a cohort of 4,698 patients with autoimmune bullous disease (AIBD), were included in this study. Of these, 332 patients were tentatively diagnosed as BP180-MMP if they showed IgG/IgA reactivity with the epidermal side of 1M NaCl-split-skin and/or positive reactivity with BP180 in at least one of our antigen detection methods. Clinically, a predominance of female patients was found. Oral mucosal and cutaneous lesions were found in 85.5% and 41.0% of patients, respectively, and frequent treatments were systemic steroids, tetracycline/minocycline and diaminodiphenyl sulfone. Various immunological methods, including a newly developed BP180 C-terminal domain enzyme-linked immunosorbent assay (ELISA), revealed frequent reactivity with BP180 C-terminal and NC16a domains. Some patients reacted with BP180 and other antigens, indicating that BP180-MMP tends to concur with other AIBDs. This large study of patients with suspected BP180-MMP indicates the difficulty of diagnosis of BP180-MMP and the diagnostic usefulness of BP180 C-terminal domain ELISA. PMID:26984589

  20. Geoarchaeological evidence from Peru for a 5000 years B.P. onset of El Nino

    SciTech Connect

    Sandweiss, D.H.; Richardson, J.B. III; Rollins, H.B.

    1996-09-13

    For the tropical west coast of South America, where El Nino/Southern Oscillation (ENSO) is most pronounced, archaeological and associated paleontological deposits in northern Peru revealed a major climate change at about 5000 years before the present (yr B.P.). The data implied the presence of stable, warm tropical water as far south as 10{degrees}S during the early mid-Holocene (about 8000 to 5000 yr B.P.). These data suggest that ENSO did not occur for some millennia preceding 5000 yr B.P., when global and regional climate was warmer than today. 36 refs., 1 fig., 3 tabs.

  1. Genetic and morphological features of human iPSC-derived neurons with chromosome 15q11.2 (BP1-BP2) deletions

    PubMed Central

    Das, DK; Tapias, V; D’Aiuto, L; Chowdari, KV; Francis, L; Zhi, Y; Ghosh, Bhattacharjee A; Surti, U; Tischfield, J; Sheldon, M; Moore, JC; Fish, K; Nimgaonkar, V

    2015-01-01

    Background Copy number variation on chromosome 15q11.2 (BP1-BP2) causes deletion of CYFIP1, NIPA1, NIPA2 and TUBGCP5; it also affects brain structure and elevates risk for several neurodevelopmental disorders that are associated with dendritic spine abnormalities. In rodents, altered cyfip1 expression changes dendritic spine morphology, motivating analyses of human neuronal cells derived from iPSCs (iPSC-neurons). Methods iPSCs were generated from a mother and her offspring, both carrying the 15q11.2 (BP1-BP2) deletion, and a non-deletion control. Gene expression in the deletion region was estimated using quantitative real-time PCR assays. Neural progenitor cells (NPCs) and iPSC-neurons were characterized using immunocytochemistry. Results CYFIP1, NIPA1, NIPA2 and TUBGCP5 gene expression was lower in iPSCs, NPCs and iPSC-neurons from the mother and her offspring in relation to control cells. CYFIP1 and PSD95 protein levels were lower in iPSC-neurons derived from the CNV bearing individuals using Western blot analysis. At 10 weeks post-differentiation, iPSC-neurons appeared to show dendritic spines and qualitative analysis suggested that dendritic morphology was altered in 15q11.2 deletion subjects compared with control cells. Conclusions The 15q11.2 (BP1-BP2) deletion is associated with reduced expression of four genes in iPSC-derived neuronal cells; it may also be associated altered iPSC-neuron dendritic morphology. PMID:26528485

  2. TARGET FRAGMENT ENERGIES AND MOMENTA IN THE REACTION OF 4.8 GeV {sup 12}C AND 5.0 GeV {sup 20}Ne WITH {sup 238}U

    SciTech Connect

    Loveland, W.; Luo, Cheng; McGaughey, P. L.; Morrissey, D. J.; Seaborg, G. T.

    1980-10-01

    Target fragment recoil properties were measured using the thick target-thick catcher technique for the interaction of 4.8 GeV {sup 12}C and 5.0 GeV {sup 20}Ne with {sup 238}U. The target fragment energies and momenta are very similar for the reaction of 4.8 GeV (400 MeV/A) {sup 12}C and 5.0 GeV (250 MeV/A) {sup 20}Ne with {sup 238}U. In the complex variation of fragment momenta with their N/Z ratio, one finds evidence suggesting the existence of several mechanisms leading to the formation of the target fragments. Comparison of these results with the predictions of the intranuclear cascade model of Yariv and Fraenkel and the firestreak model shows that both model predictions grossly overestimate the target fragment momenta.

  3. Spatial climate dynamics in the Iberian Peninsula since 15 000 yr BP

    NASA Astrophysics Data System (ADS)

    Tarroso, Pedro; Carrión, José; Dorado-Valiño, Miriam; Queiroz, Paula; Santos, Luisa; Valdeolmillos-Rodríguez, Ana; Célio Alves, Paulo; Brito, José Carlos; Cheddadi, Rachid

    2016-05-01

    Climate changes in the Iberian Peninsula since the Last Glacial Maximum are associated with distributional shifts of major Mediterranean and European temperate species. The dynamic relationship between climate and species in the past may be retrieved from the fossil records available in the Iberian Peninsula. We have used an extensive set of pollen records to reconstruct spatial layers (1 kyr interval) of January minimum temperature, July maximum temperature, and annual precipitation over the time period between 15 and 3 ka. A functional principal component analysis was used to summarise the spatial evolution of climate in areas that share similar climate trends. When compared between them, the identified four areas show different climate trends over the studied period and are coherent with the existence of multiple refugial areas within the Iberian Peninsula.

  4. [Luminescence properties of rare earth ions in 2SrO.0.84 P2O5.0.16 B2O3: RE3+ (RE=Ce, Tb)].

    PubMed

    Liu, Chun-tang; He, Da-wei; Li, Shao-xia; Liu, Duan-yang; Lu, Cheng-zhu

    2005-08-01

    The phosphors of 2SrO.0.84 P2O5.0.16 B2O3: RE3+ (RE=Ce, Tb) were synthesized by high temperature solid state reaction. The luminescence properties of Ce3+, Tb3+ and the sensitization of Ce3+ to Tb3+ were studied. In the excitation spectrum of Ce3+, there are two broad bands at 232 and 296 nm respectively. Because of the large overlap between the emission bands, the authors could not separate them from each other. The authors could get two bands at 325 and 344 nm with the Gaussian fitting method. The possible reason is that these two peaks are from two light centers. In the phosphor of 2SrO.0.84 P2O5.0.16 B2O3: Tb3+, the excitation spectrum of Tb3+ exhibits high absorption at 370 nm and emission spectrum shows the strongest emission peak at 548 nm. The emission from the levels of (5)D3 and (5)D4 of Tb3+ appear at the same time, indicating that non-radiative process between them is inefficient. In the phosphor of Ce3+ and Tb3+ co-doped 2SrO.0.84 P2.O5.0.16 B2O3, efficient energy transfer exists. PMID:16329480

  5. WS-BP: An efficient wolf search based back-propagation algorithm

    NASA Astrophysics Data System (ADS)

    Nawi, Nazri Mohd; Rehman, M. Z.; Khan, Abdullah

    2015-05-01

    Wolf Search (WS) is a heuristic based optimization algorithm. Inspired by the preying and survival capabilities of the wolves, this algorithm is highly capable to search large spaces in the candidate solutions. This paper investigates the use of WS algorithm in combination with back-propagation neural network (BPNN) algorithm to overcome the local minima problem and to improve convergence in gradient descent. The performance of the proposed Wolf Search based Back-Propagation (WS-BP) algorithm is compared with Artificial Bee Colony Back-Propagation (ABC-BP), Bat Based Back-Propagation (Bat-BP), and conventional BPNN algorithms. Specifically, OR and XOR datasets are used for training the network. The simulation results show that the WS-BP algorithm effectively avoids the local minima and converge to global minima.

  6. Identification and molecular characterization of BP75, a novel bromodomain-containing protein.

    PubMed

    Cuppen, E; van Ham, M; Pepers, B; Wieringa, B; Hendriks, W

    1999-10-15

    We here describe the identification and characterization of a novel bromodomain-containing protein, the bromodomain protein of 75 kDa (BP75). Initially, we identified BP75 in a two-hybrid screening for proteins that interact with the first PDZ (acronym for post-synaptic density protein PSD-95, Drosophila discs large tumor suppressor DlgA and the tight junction protein ZO-1) domain in protein tyrosine phosphatase-BAS-like (PTP-BL). We found that BP75 is expressed ubiquitously and show that both BP75 and a PTP-BL deletion mutant consisting of the first PDZ domain are located mainly in the nucleus, although cytoplasmic localization is also evident. Full-length PTP-BL, on the contrary, is predominantly localized in the cytoplasm, although some basal nuclear staining is observed. The described molecular interaction may reflect a mechanism of coupling submembraneous signalling events and nuclear events. PMID:10526152

  7. Prediction of BP reactivity to talking using hybrid soft computing approaches.

    PubMed

    Kaur, Gurmanik; Arora, Ajat Shatru; Jain, Vijender Kumar

    2014-01-01

    High blood pressure (BP) is associated with an increased risk of cardiovascular diseases. Therefore, optimal precision in measurement of BP is appropriate in clinical and research studies. In this work, anthropometric characteristics including age, height, weight, body mass index (BMI), and arm circumference (AC) were used as independent predictor variables for the prediction of BP reactivity to talking. Principal component analysis (PCA) was fused with artificial neural network (ANN), adaptive neurofuzzy inference system (ANFIS), and least square-support vector machine (LS-SVM) model to remove the multicollinearity effect among anthropometric predictor variables. The statistical tests in terms of coefficient of determination (R (2)), root mean square error (RMSE), and mean absolute percentage error (MAPE) revealed that PCA based LS-SVM (PCA-LS-SVM) model produced a more efficient prediction of BP reactivity as compared to other models. This assessment presents the importance and advantages posed by PCA fused prediction models for prediction of biological variables. PMID:25328536

  8. 1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER SUBSTATIONS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  9. Prediction of BP Reactivity to Talking Using Hybrid Soft Computing Approaches

    PubMed Central

    Arora, Ajat Shatru; Jain, Vijender Kumar

    2014-01-01

    High blood pressure (BP) is associated with an increased risk of cardiovascular diseases. Therefore, optimal precision in measurement of BP is appropriate in clinical and research studies. In this work, anthropometric characteristics including age, height, weight, body mass index (BMI), and arm circumference (AC) were used as independent predictor variables for the prediction of BP reactivity to talking. Principal component analysis (PCA) was fused with artificial neural network (ANN), adaptive neurofuzzy inference system (ANFIS), and least square-support vector machine (LS-SVM) model to remove the multicollinearity effect among anthropometric predictor variables. The statistical tests in terms of coefficient of determination (R 2), root mean square error (RMSE), and mean absolute percentage error (MAPE) revealed that PCA based LS-SVM (PCA-LS-SVM) model produced a more efficient prediction of BP reactivity as compared to other models. This assessment presents the importance and advantages posed by PCA fused prediction models for prediction of biological variables. PMID:25328536

  10. Sodium nitroprusside: low price and safe drug to control BP during thrombolysis in AIS.

    PubMed

    Koslyk, Jessyca L; Ducci, Renata D; Nóvak, Edison M; Zétola, Viviane F; Lange, Marcos C

    2015-09-01

    This study analyzes the use of sodium nitroprusside (SN) as an option to reduce blood pressure (BP) below 180/105 mmHg during the management of acute ischemic stroke (AIS) in patients submitted to intravenous thrombolysis.Method The sample was composed by 60 patients who had AIS and were submitted to intravenous rtPA, split in two groups: half in the control group (CG) with BP < 180/105 mmHg and half in SN group with BP > 180/105 mmHg. Outcome variables were any hemorrhagic transformation (HT); the presence of symptomatic HT, National Institute of Health Stroke Scale (NIHSS) after 24 hours of treatment; the independence on discharge and death until three months after stroke onset.Results There were no statistical differences between both groups to any of the outcome variables analyzed.Conclusion The SN might be safe for BP control during thrombolysis to AIS. PMID:26352493

  11. Environmental Conditions in northern Gulf of Mexico Estuaries: before and after the BP Oil Spill

    EPA Science Inventory

    This presentation provides a summary of ecological condition and sediment chemistry data for northern Gulf of Mexico estuaries that were exposed to oil and oil-related contaminants from the BP Oil Spill.

  12. Role of the CacyBP/SIP protein in gastric cancer

    PubMed Central

    ZHAI, HUIHONG; MENG, JUAN; JIN, HAIFENG; LI, YUANFEI; WANG, JINBO

    2015-01-01

    Various reports indicate that calcyclin binding protein/Siah-1-interacting protein (CacyBP/SIP) is an important protein in tumorigenesis, but whether CacyBP/SIP promotes or suppresses cancer may depend on the cell type. In order to investigate whether CacyBP/SIP is significant in gastric cancerous tumorigenesis, the present study used immunohistochemistry to analyze 181 gastric cancer tissue samples, as well as 181 healthy tissue samples from the same gastric cancer patients. The immunohistochemical results were compared against patient data and pathological analysis of the tissue slices, including gender, age, degree of tumor differentiation and tumor, node, metastasis (TNM) stage. In addition, the level of CacyBP/SIP expression was detected in three frozen tissue samples of gastric adenocarcinoma using western blot analysis. Of the 181 cases analyzed in the present study, 80 cases were identified as non-metastatic gastric cancer and 101 cases were identified as gastric cancer that had metastasized to the lymph nodes. Tissue biopsies from the two sets of patients were examined using immunohistochemistry to identify the level of CacyBP/SIP expression in metastatic and primary gastric cancer tissues. Statistical analyses were performed on all data. The immunohistochemical analysis revealed that CacyBP/SIP was expressed in 31% (56/181) of gastric adenocarcinoma tissue samples and 7% (12/181) of adjacent non-cancerous gastric tissues (P<0.05). Furthermore, the expression levels of CacyBP/SIP were higher in cancerous tissue compared with the adjacent non-cancerous gastric tissue using western blotting. No association was identified between CacyBP/SIP expression and patient age (P=0.975), gender (P=0.185), degree of tumor differentiation (P=0.076) or TNM stage (P=0.979). Among the 101 patients with metastatic gastric cancer, CacyBP/SIP was expressed at primary sites in 31% (31/101) of cases and at metastatic sites in 26% (26/101) of cases (P=0.434). However, among the

  13. A Role for Anti-BP180 Autoantibodies in Chronic Rhinosinusitis

    PubMed Central

    Jeffe, Jill S.; Seshadri, Sudarshan; Hamill, Kevin J.; Huang, Julia He; Carter, Roderick; Suh, Lydia; Hulse, Kathryn; Norton, James; Conley, David B.; Chandra, Rakesh K.; Kern, Robert C.; Jones, Jonathan C.R.; Schleimer, Robert P.; Tan, Bruce K.

    2013-01-01

    Objectives CRS is accompanied by evidence of a vigorous adaptive immune response, and emerging studies demonstrate that some nasal polyps manifest a polyclonal autoantibody response. We previously found that antibodies against BP180, a component of the hemidesmosome complex and the dominant epitope in autoimmune bullous pemphigoid, were found at elevated levels in nasal polyp tissue. Given the critical role of hemidesmosomes in maintaining epithelial integrity, we sought to investigate the distribution of BP180 in nasal tissue and evaluate for evidence of systemic autoimmunity against this antigen in CRS. Study Design Case-control experimental study Methods The expression and distribution of BP180 in cultured nasal epithelial cells and normal nasal tissue were confirmed using real-time PCR, Western immunoblotting, immunofluorescence and immunohistochemistry. Sera were collected from three groups: control, CRSsNP, and CRSwNP. A commercially available ELISA was utilized to compare anti-BP180 autoantibody levels in sera. Results BP180 is expressed in nasal epithelium, but is not confined to the basement membrane as it is in human skin. In cultured nasal epithelial cells, confocal immunofluoresence showed a punctate distribution of BP180 along the basal surface, consistent with its distribution in epithelial keratinocytes. There are significantly higher levels of circulating nonpathologic anti-BP180 autoantibodies in CRS patients compared with normal controls (p<0.05). Conclusions BP180 is more widely expressed in nasal epithelium versus skin, although it appears to play a similar role in formation of hemidesmosomes along the basement membrane. Further investigations are ongoing to characterize the pathogenicity of the anti-epithelial antibody response in CRS. PMID:24167818

  14. RNA-binding protein IGF2BP3 targeting of oncogenic transcripts promotes hematopoietic progenitor proliferation

    PubMed Central

    Palanichamy, Jayanth Kumar; Tran, Tiffany M.; Howard, Jonathan M.; Contreras, Jorge R.; Fernando, Thilini R.; Sterne-Weiler, Timothy; Katzman, Sol; Toloue, Masoud; Yan, Weihong; Sanford, Jeremy R.; Rao, Dinesh S.

    2016-01-01

    Posttranscriptional control of gene expression is important for defining both normal and pathological cellular phenotypes. In vitro, RNA-binding proteins (RBPs) have recently been shown to play important roles in posttranscriptional regulation; however, the contribution of RBPs to cell specification is not well understood. Here, we determined that the RBP insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is specifically overexpressed in mixed lineage leukemia–rearranged (MLL-rearranged) B-acute lymphoblastic leukemia (B-ALL), which constitutes a subtype of this malignancy associated with poor prognosis and high risk of relapse. IGF2BP3 was required for the survival of B-ALL cell lines, as knockdown led to decreased proliferation and increased apoptosis. Enforced expression of IGF2BP3 provided murine BM cells with a strong survival advantage, led to proliferation of hematopoietic stem and progenitor cells, and skewed hematopoietic development to the B cell/myeloid lineage. Cross-link immunoprecipitation and high throughput sequencing uncovered the IGF2BP3-regulated transcriptome, which includes oncogenes MYC and CDK6 as direct targets. IGF2BP3 regulated transcripts via targeting elements within 3′ untranslated regions (3′UTR), and enforced IGF2BP3 expression in mice resulted in enhanced expression of Myc and Cdk6 in BM. Together, our data suggest that IGF2BP3-mediated targeting of oncogenic transcripts may represent a critical pathogenetic mechanism in MLL-rearranged B-ALL and support IGF2BP3 and its cognate RNA-binding partners as potential therapeutic targets in this disease. PMID:26974154

  15. A novel E4BP4 element drives circadian expression of mPeriod2.

    PubMed

    Ohno, Tomoya; Onishi, Yoshiaki; Ishida, Norio

    2007-01-01

    Period2 (Per2) is an essential component of the mammalian clock mechanism and robust circadian expression of Per2 is essential for the maintenance of circadian rhythms. Although recent studies have shown that the circadian E2 enhancer (a non-canonical E-box) accounts for most of the circadian transcriptional drive of mPer2, little is known about the other cis-elements of mPer2 oscillatory transcription. Here, we examined the contribution of E4BP4 to Per2 mRNA oscillation in the cell-autonomous clock. Knockdown experiments of E4BP4 in both Northern blots and real-time luciferase assays suggested that endogenous E4BP4 negatively regulates Per2 mRNA oscillation. Sequence analysis revealed two putative E4BP4-binding sites (termed A-site and B-site) on mammalian Per2 promoter regions. Luciferase assays with mutant constructs showed that a novel E4BP4-binding site (B-site) is responsible for E4BP4-mediated transcriptional repression of Per2. Furthermore, chromatin immunoprecipitation assays in vivo showed that the peak of E4BP4 binding to the B-site on the Per2 promoter almost matched the trough of Per2 mRNA expression. Importantly, real-time luciferase assays showed that the B-site in addition to the E2 enhancer is required for robust circadian expression of Per2 in the cell-autonomous clock. These findings indicated that E4BP4 is required for the negative regulation of mammalian circadian clocks. PMID:17182630

  16. Discrete Sampling Test Plan for the 200-BP-5 Operable Unit

    SciTech Connect

    Sweeney, Mark D.

    2010-02-04

    The Discrete Groundwater Sampling Project is conducted by the Pacific Northwest National Laboratory (PNNL) on behalf of CH2M HILL Plateau Remediation Company. The project is focused on delivering groundwater samples from proscribed horizons within select groundwater wells residing in the 200-BP-5 Operable Unit (200-BP-5 OU) on the Hanford Site. This document provides the scope, schedule, methodology, and other details of the PNNL discrete sampling effort.

  17. Occurrence of 4-tert-butylphenol (4-t-BP) biodegradation in an aquatic sample caused by the presence of Spirodela polyrrhiza and isolation of a 4-t-BP-utilizing bacterium.

    PubMed

    Ogata, Yuka; Toyama, Tadashi; Yu, Ning; Wang, Xuan; Sei, Kazunari; Ike, Michihiko

    2013-04-01

    Although 4-tert-butylphenol (4-t-BP) is a serious aquatic pollutant, its biodegradation in aquatic environments has not been well documented. In this study, 4-t-BP was obviously and repeatedly removed from water from four different environments in the presence of Spirodela polyrrhiza, giant duckweed, but 4-t-BP persisted in the environmental waters in the absence of S. polyrrhiza. Also, 4-t-BP was not removed from autoclaved pond water with sterilized S. polyrrhiza. These results suggest that the 4-t-BP removal from the environmental waters was caused by biodegradation stimulated by the presence of S. polyrrhiza rather than by uptake by the plant. Moreover, Sphingobium fuliginis OMI capable of utilizing 4-t-BP as a sole carbon and energy source was isolated from the S. polyrrhiza rhizosphere. Strain OMI degraded 4-t-BP via a meta-cleavage pathway, and also degraded a broad range of alkylphenols with linear or branched alkyl side chains containing two to nine carbon atoms. Root exudates of S. polyrrhiza stimulated 4-t-BP degradation and cell growth of strain OMI. Thus, the stimulating effects of S. polyrrhiza root exudates on 4-t-BP-degrading bacteria might have contributed to 4-t-BP removal in the environmental waters with S. polyrrhiza. These results demonstrate that the S. polyrrhiza-bacteria association may be applicable to the removal of highly persistent 4-t-BP from wastewaters or polluted aquatic environments. PMID:22777343

  18. Effects of BP-14, a novel cyclin-dependent kinase inhibitor, on anaplastic thyroid cancer cells.

    PubMed

    Allegri, Lorenzo; Baldan, Federica; Mio, Catia; Puppin, Cinzia; Russo, Diego; Kryštof, Vladimir; Damante, Giuseppe

    2016-04-01

    Anaplastic thyroid carcinoma (ATC) is an extremely aggressive human malignancy characterized by a marked degree of invasiveness, absense of features of thyroid differentiation and resistance to current medical treatment. It is well known that ATCs are characterized by deregulation of genes related to cell cycle regulation, i.e., cyclin-dependent kinases (CDKs) and endogenous cyclin-dependent kinase inhibitors (CDKIs). Therefore, in the present study, the effect of a novel exogenous cyclin-dependent kinase inhibitor, BP-14, was investigated in three human ATC cell lines. The ATC-derived cell lines FRO, SW1736 and 8505C were treated with BP-14 alone or in combination with the mTOR inhibitor everolimus. In all ATC cell lines, treatment with BP-14 decreased cell viability and, in two of them, BP-14 modified expression of genes involved in epithelial-mesenchymal transition. Thus, our data indicate that BP-14 is a potential new compound effective against ATC. Combined treatment with BP-14 and the mTOR inhibitor everolimus had a strong synergistic effect on cell viability in all three cell lines, suggesting that the combined used of CDK and mTOR inhibitors may be a useful strategy for ATC treatment. PMID:26884249

  19. Translation control during prolonged mTORC1 inhibition mediated by 4E-BP3.

    PubMed

    Tsukumo, Yoshinori; Alain, Tommy; Fonseca, Bruno D; Nadon, Robert; Sonenberg, Nahum

    2016-01-01

    Targeting mTORC1 is a highly promising strategy in cancer therapy. Suppression of mTORC1 activity leads to rapid dephosphorylation of eIF4E-binding proteins (4E-BP1-3) and subsequent inhibition of mRNA translation. However, how the different 4E-BPs affect translation during prolonged use of mTOR inhibitors is not known. Here we show that the expression of 4E-BP3, but not that of 4E-BP1 or 4E-BP2, is transcriptionally induced during prolonged mTORC1 inhibition in vitro and in vivo. Mechanistically, our data reveal that 4E-BP3 expression is controlled by the transcription factor TFE3 through a cis-regulatory element in the EIF4EBP3 gene promoter. CRISPR/Cas9-mediated EIF4EBP3 gene disruption in human cancer cells mitigated the inhibition of translation and proliferation caused by prolonged treatment with mTOR inhibitors. Our findings show that 4E-BP3 is an important effector of mTORC1 and a robust predictive biomarker of therapeutic response to prolonged treatment with mTOR-targeting drugs in cancer. PMID:27319316

  20. Translation control during prolonged mTORC1 inhibition mediated by 4E-BP3

    PubMed Central

    Tsukumo, Yoshinori; Alain, Tommy; Fonseca, Bruno D.; Nadon, Robert; Sonenberg, Nahum

    2016-01-01

    Targeting mTORC1 is a highly promising strategy in cancer therapy. Suppression of mTORC1 activity leads to rapid dephosphorylation of eIF4E-binding proteins (4E-BP1–3) and subsequent inhibition of mRNA translation. However, how the different 4E-BPs affect translation during prolonged use of mTOR inhibitors is not known. Here we show that the expression of 4E-BP3, but not that of 4E-BP1 or 4E-BP2, is transcriptionally induced during prolonged mTORC1 inhibition in vitro and in vivo. Mechanistically, our data reveal that 4E-BP3 expression is controlled by the transcription factor TFE3 through a cis-regulatory element in the EIF4EBP3 gene promoter. CRISPR/Cas9-mediated EIF4EBP3 gene disruption in human cancer cells mitigated the inhibition of translation and proliferation caused by prolonged treatment with mTOR inhibitors. Our findings show that 4E-BP3 is an important effector of mTORC1 and a robust predictive biomarker of therapeutic response to prolonged treatment with mTOR-targeting drugs in cancer. PMID:27319316

  1. CtBP1 associates metabolic syndrome and breast carcinogenesis targeting multiple miRNAs

    PubMed Central

    De Luca, Paola; Dalton, Guillermo N.; Scalise, Georgina D.; Moiola, Cristian P.; Porretti, Juliana; Massillo, Cintia; Kordon, Edith; Gardner, Kevin; Zalazar, Florencia; Flumian, Carolina; Todaro, Laura; Vazquez, Elba S.; Meiss, Roberto; De Siervi, Adriana

    2016-01-01

    Metabolic syndrome (MeS) has been identified as a risk factor for breast cancer. C-terminal binding protein 1 (CtBP1) is a co-repressor of tumor suppressor genes that is activated by low NAD+/NADH ratio. High fat diet (HFD) increases intracellular NADH. We investigated the effect of CtBP1 hyperactivation by HFD intake on mouse breast carcinogenesis. We generated a MeS-like disease in female mice by chronically feeding animals with HFD. MeS increased postnatal mammary gland development and generated prominent duct patterns with markedly increased CtBP1 and Cyclin D1 expression. CtBP1 induced breast cancer cells proliferation. Serum from animals with MeS enriched the stem-like/progenitor cell population from breast cancer cells. CtBP1 increased breast tumor growth in MeS mice modulating multiple genes and miRNA expression implicated in cell proliferation, progenitor cells phenotype, epithelial to mesenchymal transition, mammary development and cell communication in the xenografts. These results define a novel function for CtBP1 in breast carcinogenesis. PMID:26933806

  2. CtBP1 associates metabolic syndrome and breast carcinogenesis targeting multiple miRNAs.

    PubMed

    De Luca, Paola; Dalton, Guillermo N; Scalise, Georgina D; Moiola, Cristian P; Porretti, Juliana; Massillo, Cintia; Kordon, Edith; Gardner, Kevin; Zalazar, Florencia; Flumian, Carolina; Todaro, Laura; Vazquez, Elba S; Meiss, Roberto; De Siervi, Adriana

    2016-04-01

    Metabolic syndrome (MeS) has been identified as a risk factor for breast cancer. C-terminal binding protein 1 (CtBP1) is a co-repressor of tumor suppressor genes that is activated by low NAD+/NADH ratio. High fat diet (HFD) increases intracellular NADH. We investigated the effect of CtBP1 hyperactivation by HFD intake on mouse breast carcinogenesis. We generated a MeS-like disease in female mice by chronically feeding animals with HFD. MeS increased postnatal mammary gland development and generated prominent duct patterns with markedly increased CtBP1 and Cyclin D1 expression. CtBP1 induced breast cancer cells proliferation. Serum from animals with MeS enriched the stem-like/progenitor cell population from breast cancer cells. CtBP1 increased breast tumor growth in MeS mice modulating multiple genes and miRNA expression implicated in cell proliferation, progenitor cells phenotype, epithelial to mesenchymal transition, mammary development and cell communication in the xenografts. These results define a novel function for CtBP1 in breast carcinogenesis. PMID:26933806

  3. Asian-specific mitochondrial genome polymorphism (9-bp deletion) in Hungarian patients with mitochondrial disease.

    PubMed

    Pentelenyi, Klara; Remenyi, Viktoria; Gal, Aniko; Milley, Gyorgy Mate; Csosz, Aranka; Mende, Balazs Gusztav; Molnar, Maria Judit

    2016-05-01

    A 9-bp deletion of the mtDNA is known as an anthropological marker of people with East-Asian origin. This 9-bp mtDNA deletion was analyzed in 1073 Hungarians with suspected mitochondrial disease and in 468 healthy control individuals. Fourteen cases with the 9-bp deletion were found in the cohort of mitochondrial patients, and one individual from 468 controls. In six cases the 9-bp deletion was present together with pathogenic major deletions in the mitochondrial genome. In one patient we found a frame shift mutation in the D-loop region, and in another family a pathogenic m.8322 A > G mutation in the tRNA(Lys) gene. Although the 9-bp deletion is common in the populations of the Pacific region and Asia, it is present in the Hungarian population as well. This 9-bp deletion may induce instability of the mtDNA and may provoke the introduction of other pathogenic mutations. PMID:25242187

  4. 53BP1 fosters fidelity of homology-directed DNA repair.

    PubMed

    Ochs, Fena; Somyajit, Kumar; Altmeyer, Matthias; Rask, Maj-Britt; Lukas, Jiri; Lukas, Claudia

    2016-08-01

    Repair of DNA double-strand breaks (DSBs) in mammals is coordinated by the ubiquitin-dependent accumulation of 53BP1 at DSB-flanking chromatin. Owing to its ability to limit DNA-end processing, 53BP1 is thought to promote nonhomologous end-joining (NHEJ) and to suppress homology-directed repair (HDR). Here, we show that silencing 53BP1 or exhausting its capacity to bind damaged chromatin changes limited DSB resection to hyper-resection and results in a switch from error-free gene conversion by RAD51 to mutagenic single-strand annealing by RAD52. Thus, rather than suppressing HDR, 53BP1 fosters its fidelity. These findings illuminate causes and consequences of synthetic viability acquired through 53BP1 silencing in cells lacking the BRCA1 tumor suppressor. We show that such cells survive DSB assaults at the cost of increasing reliance on RAD52-mediated HDR, which may fuel genome instability. However, our findings suggest that when challenged by DSBs, BRCA1- and 53BP1-deficient cells may become hypersensitive to, and be eliminated by, RAD52 inhibition. PMID:27348077

  5. Structural plasticity of methyllysine recognition by the tandem Tudor domain of 53BP1

    PubMed Central

    Tong, Qiong; Cui, Gaofeng; Botuyan, Maria Victoria; Rothbart, Scott B.; Hayashi, Ryo; Musselman, Catherine A.; Singh, Namit; Appella, Ettore; Strahl, Brian D.; Mer, Georges; Kutateladze, Tatiana G.

    2014-01-01

    SUMMARY p53 is dynamically regulated through various posttranslational modifications (PTMs), which differentially modulate its function and stability. The dimethylated marks p53K370me2 and p53K382me2 are associated with p53 activation or stabilization and both are recognized by the tandem Tudor domain (TTD) of 53BP1, a p53 co-factor. Here we detail the molecular mechanisms for the recognition of p53K370me2 and p53K382me2 by 53BP1. The solution structures of TTD in complex with the p53K370me2 and p53K382me2 peptides show a remarkable plasticity of 53BP1 in accommodating these diverse dimethyllysine-containing sequences. We demonstrate that dimeric TTDs are capable of interacting with the two PTMs on a single p53K370me2K382me2 peptide, greatly strengthening the 53BP1-p53 interaction. Analysis of binding affinities of TTD toward methylated p53 and histones reveals strong preference of 53BP1 for p53K382me2, H4K20me2, and H3K36me2 and suggests a possible role of multivalent contacts of 53BP1 in p53 targeting to and accumulation at the sites of DNA damage. PMID:25579814

  6. The negative transcription factor E4BP4 is associated with circadian clock protein PERIOD2.

    PubMed

    Ohno, Tomoya; Onishi, Yoshiaki; Ishida, Norio

    2007-03-23

    The bZIP transcription factor E4BP4, is a mammalian homologue of vrille that functions as a key negative component of the circadian clock. We have shown that the E4BP4-binding site (B-site) is required in addition to a non-canonical E-box (E2 enhancer) for robust circadian Period2 (Per2) expression in the cell-autonomous clock. While the E2 enhancer and the B-site are closely situated, correlations between each component bound to the E2 enhancer and the B-site remain obscure. Here, we show that E4BP4 interacts with PER2, which represses transcriptional activity via the E-box enhancer. Interaction with PER2 required the carboxyl-terminal region that contains the repression domain of E4BP4. We also found that E4BP4 interacts with CRYPTOCHROME2 (CRY2), a key negative regulator in the mammalian circadian clock. These results suggest that E4BP4 is a component of the negative regulator complex of mammalian circadian clocks. PMID:17274955

  7. The preparation of BP single crystals by high pressure flux method

    NASA Technical Reports Server (NTRS)

    Kumashiro, Y.; Misawa, S.; Gonda, S.

    1984-01-01

    Single crystals of BP, a III-V compound semiconductor, were obtained by the high pressure flux method. Cu3P and Ni12P5 powders were used as the flux, and mixed with BP powder. Two kinds of mixtures were prepared: (1) 1.8g (BP) + 35 G (Cu3P) and (2) 1.7 g (BP) + 25 g (Ni12P5). They were compressed into pellets, heated at 1300 C for 24 h in an induction furnace under a pressure of 1 MPa using Ar-P2 gas, and slowly cooled to room temperature. In case (1), BP single crystals grew along the (III) plane, and in case (2) they grew as an aggregate of crystallites. The cathodoluminescence spectra of the synthetic BP crystals showed peaks near 680 nm (1.82 eV) for case (1), and 500 nm (2.47 eV) for case (2). By using the high pressure flux method conventional sized crystals were obtained in a relatively short time.

  8. Regulation of B cell differentiation by the ubiquitin-binding protein TAX1BP1

    PubMed Central

    Matsushita, Nobuko; Suzuki, Midori; Ikebe, Emi; Nagashima, Shun; Inatome, Ryoko; Asano, Kenichi; Tanaka, Masato; Matsushita, Masayuki; Kondo, Eisaku; Iha, Hidekatsu; Yanagi, Shigeru

    2016-01-01

    Tax1-binding protein 1 (TAX1BP1) is a ubiquitin-binding protein that restricts nuclear factor-κB (NF-κB) activation and facilitates the termination of aberrant inflammation. However, its roles in B-cell activation and differentiation are poorly understood. To evaluate the function of TAX1BP1 in B cells, we established TAX1BP1-deficient DT40 B cells that are hyper-responsive to CD40-induced extracellular signal-regulated kinase (ERK) activation signaling, exhibit prolonged and exaggerated ERK phosphorylation and show enhanced B lymphocyte-induced maturation protein 1 (Blimp-1; a transcription factor inducing plasma cell differentiation) expression that is ERK-dependent. Furthermore, TAX1BP1-deficient cells exhibit significantly decreased surface IgM expression and increased IgM secretion. Moreover, TAX1BP1-deficient mice display reduced germinal center formation and antigen-specific antibody production. These findings show that TAX1BP1 restricts ERK activation and Blimp-1 expression and regulates germinal center formation. PMID:27515252

  9. The effects of PEP-1-FK506BP on dry eye disease in a rat model

    PubMed Central

    Kim, Dae Won; Lee, Sung Ho; Ku, Sae Kwang; Lee, Ji Eun; Cha, Hyun Ju; Youn, Jong Kyu; Kwon, Hyeok Yil; Park, Jong Hoon; Park, Eun Young; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    As FK506 binding proteins (FK506BPs) are known to play an important role in the regulation of a variety of biological processes related to cell survival, this study was designed to examined the protective effects of FK506 binding protein 12 (FK506BP) on low humidity air flow induced dry eye in a rat model using transduced PEP-1-FK506BP. After the topical application of PEP-1-FK506BP, tear volumes were markedly increased and significant prevention of cornea damage was observed compared with dry eye rats. Further, immunohistochemical analysis demonstrated that PEP-1-FK506BP markedly prevented damage to the cornea, the bulbar conjunctiva, and the palpebral conjunctiva epithelial lining compared with dry eye rats. In addition, caspase-3 and PARP expression levels were found to be decreased. These results demonstrated that topical application of PEP-1-FK506BP significantly ameliorates dry eye injury in an animal model. Thus, we suggest that PEP-1-FK506BP can be developed as a new ophthalmic drop to treat dry eye diseases. [BMB Reports 2015; 48(3): 153-158] PMID:24998262

  10. 15q11.2 microdeletion (BP1-BP2) and developmental delay, behaviour issues, epilepsy and congenital heart disease: a series of 52 patients.

    PubMed

    Vanlerberghe, Clémence; Petit, Florence; Malan, Valérie; Vincent-Delorme, Catherine; Bouquillon, Sonia; Boute, Odile; Holder-Espinasse, Muriel; Delobel, Bruno; Duban, Bénédicte; Vallee, Louis; Cuisset, Jean-Marie; Lemaitre, Marie-Pierre; Vantyghem, Marie-Christine; Pigeyre, Marie; Lanco-Dosen, Sandrine; Plessis, Ghislaine; Gerard, Marion; Decamp, Matthieu; Mathieu, Michèle; Morin, Gilles; Jedraszak, Guillaume; Bilan, Frédéric; Gilbert-Dussardier, Brigitte; Fauvert, Delphine; Roume, Joëlle; Cormier-Daire, Valérie; Caumes, Roseline; Puechberty, Jacques; Genevieve, David; Sarda, Pierre; Pinson, Lucie; Blanchet, Patricia; Lemeur, Nathalie; Sheth, Frenny; Manouvrier-Hanu, Sylvie; Andrieux, Joris

    2015-03-01

    Proximal region of chromosome 15 long arm is rich in duplicons that, define five breakpoints (BP) for 15q rearrangements. 15q11.2 microdeletion between BP1 and BP2 has been previously associated with developmental delay and atypical psychological patterns. This region contains four highly-conserved and non-imprinted genes: NIPA1, NIPA2, CYFIP1, TUBGCP5. Our goal was to investigate the phenotypes associated with this microdeletion in a cohort of 52 patients. This copy number variation (CNV) was prevalent in 0.8% patients presenting with developmental delay, psychological pattern issues and/or multiple congenital malformations. This was studied by array-CGH at six different French Genetic laboratories. We collected data from 52 unrelated patients (including 3 foetuses) after excluding patients with an associated genetic alteration (known CNV, aneuploidy or known monogenic disease). Out of 52 patients, mild or moderate developmental delay was observed in 68.3%, 85.4% had speech impairment and 63.4% had psychological issues such as Attention Deficit and Hyperactivity Disorder, Autistic Spectrum Disorder or Obsessive-Compulsive Disorder. Seizures were noted in 18.7% patients and associated congenital heart disease in 17.3%. Parents were analysed for abnormalities in the region in 65.4% families. Amongst these families, 'de novo' microdeletions were observed in 18.8% and 81.2% were inherited from one of the parents. Incomplete penetrance and variable expressivity were observed amongst the patients. Our results support the hypothesis that 15q11.2 (BP1-BP2) microdeletion is associated with developmental delay, abnormal behaviour, generalized epilepsy and congenital heart disease. The later feature has been rarely described. Incomplete penetrance and variability of expression demands further assessment and studies. PMID:25596525

  11. G3BP-Caprin1-USP10 complexes mediate stress granule condensation and associate with 40S subunits.

    PubMed

    Kedersha, Nancy; Panas, Marc D; Achorn, Christopher A; Lyons, Shawn; Tisdale, Sarah; Hickman, Tyler; Thomas, Marshall; Lieberman, Judy; McInerney, Gerald M; Ivanov, Pavel; Anderson, Paul

    2016-03-28

    Mammalian stress granules (SGs) contain stalled translation preinitiation complexes that are assembled into discrete granules by specific RNA-binding proteins such as G3BP. We now show that cells lacking both G3BP1 and G3BP2 cannot form SGs in response to eukaryotic initiation factor 2α phosphorylation or eIF4A inhibition, but are still SG-competent when challenged with severe heat or osmotic stress. Rescue experiments using G3BP1 mutants show that phosphomimetic G3BP1-S149E fails to rescue SG formation, whereas G3BP1-F33W, a mutant unable to bind G3BP partner proteins Caprin1 or USP10, rescues SG formation. Caprin1/USP10 binding to G3BP is mutually exclusive: Caprin binding promotes, but USP10 binding inhibits, SG formation. G3BP interacts with 40S ribosomal subunits through its RGG motif, which is also required for G3BP-mediated SG formation. We propose that G3BP mediates the condensation of SGs by shifting between two different states that are controlled by the phosphorylation of S149 and by binding to Caprin1 or USP10. PMID:27022092

  12. Identification and characterization of a novel calcyclin binding protein (CacyBP) gene from Apis cerana cerana.

    PubMed

    Yu, Xiaoli; Lu, Wenjing; Sun, Rujiang; Guo, Xingqi; Xu, Baohua

    2012-08-01

    Calcyclin binding protein (CacyBP), a homolog of Sgt1, was shown to interact with some S100 proteins, Skp1, tubulin, actin and ERK1/2 kinases. Studies have also shown that CacyBP is a neuronal protein in mammals. Limited information is available regarding the properties and functions of CacyBP in insects. Here, we cloned and characterized a novel CacyBP gene, named AccCacyBP, from honeybee (Apis cerana cerana). Bioinformatic analysis indicated that AccCacyBP was highly conserved and closely related to the CacyBP of other insects. Promoter analysis revealed a number of putative tissue, development and stress-related transcription factor-binding sites. RT-qPCR demonstrated that AccCacyBP was expressed at all of the stages of development, especially in the brains of honeybees. Moreover, immunohistochemistry analysis showed the presence of AccCacyBP in the brain. The transcript levels of AccCacyBP in the brains of honeybees were developmentally induced and upregulated by exposure to oxidative stresses, including UV-light, acetamiprid and HgCl(2). This study demonstrates that the CacyBP gene in honeybees may be a neuronal protein involved in the developmental regulation and the stress-response of the brain of honeybees. PMID:22539186

  13. Non-monotonic mobility vs. length dependence observed in electrophoretic separation of 25 bp DNA ladder in Pluronic gels.

    NASA Astrophysics Data System (ADS)

    You, Seungyong; van Winkle, David

    2009-03-01

    We electrophoresed a double-stranded DNA ladder first in an agarose gel, then in gels of Pluronic F-127 at room temperature. The DNA ladder consisted of 19 discrete fragments ranging in length from 25 to 450 bp at 25 bp increments plus 500 bp. The DNA fragments were first separated in agarose gel and stacked normally with 25 bp having the highest mobility. A single lane of the separated DNA ladder in the agarose gel was inserted at the edge of a Pluronic gel slab. The DNA was electrophoresed from the agarose into the Pluronic gels perpendicular to the original separation axis. Mobilities of DNA fragments increased from 25 bp to 175 bp and then decreased from 175 bp to 500 bp. The 25 bp and 500 bp bands of the ladder had approximately the same mobility in several different Pluronic gel concentrations. Both were slower than most bands in between. The highest mobility fragments with length of 175 bp have 59.5 nm contour length which is about 3.5 times the diameter of a micelle (17 nm). This result suggests a crossover from chromatographic separation to electrophoretic separation for these short DNAs. This research is supported by the state of Florida (Martech) and Research Corporation.

  14. BpMADS4 has a central role in inflorescence initiation in silver birch (Betula pendula).

    PubMed

    Elo, Annakaisa; Lemmetyinen, Juha; Novak, Anu; Keinonen, Kaija; Porali, Ilkka; Hassinen, Minna; Sopanen, Tuomas

    2007-09-01

    Acceleration of flowering would be beneficial for breeding trees with a long juvenile phase; conversely, inhibition of flowering would prevent the spread of transgenes from the genetically modified trees. We have previously isolated and characterized several MADS genes from silver birch (Betula pendula Roth). In this study, we investigated the more detailed function of one of them, BpMADS4, a member of the APETALA1/FRUITFULL group of MADS genes. The expression of BpMADS4 starts at very early stage of the male and female inflorescence development and the activity is high in the apex of the developing inflorescence. Later, some expression is detected in the bracts and in the flower initials. Ectopic expression of BpMADS4 accelerates flowering dramatically in normally flowering clones and also in the early-flowering birch clone, in which the earliest line flowered about 11 days after rooting, when the saplings were only 3 cm high. The birches transformed with the BpMADS4 antisense construct showed remarkable delay in flowering and the number of flowering individuals was reduced. Two of the transformed lines did not show any signs of flower development during our 2-year study, whereas all the control plants formed inflorescences within 107 days. Our results show that BpMADS4 has a critical role in the initiation of birch inflorescence development and that BpMADS4 seems to be involved in the transition from vegetative to reproductive development. Therefore, BpMADS4 provides a promising tool for the genetic enhancement of forest trees. PMID:18251933

  15. Differential cross sections for scattering of 0.5-, 1.5-, and 5.0-keV hydrogen atoms by He, H2, N2, and O2

    NASA Technical Reports Server (NTRS)

    Newman, J. H.; Chen, Y. S.; Smith, K. A.; Stebbings, R. F.

    1986-01-01

    This paper reports measurements of absolute cross sections, differential in angle, for scattering of 0.5-, 1.5-, and 5.0-keV hydrogen atoms by He, H2, N2, and O2 at laboratory scattering angles between 0.1 and 5 deg. The measured cross sections are the sums of those for elastic and inelastic collisions having a fast H atom product and are needed for calculating energy transfer to the upper atmosphere from precipitating ring current particles.

  16. Determination of the cross section of the proton, pion and neutron inelastic interaction with lead and carbon nuclei at 0.5 - 5.0 TeV energies (PION experiment)

    NASA Technical Reports Server (NTRS)

    Keropian, M. I.; Martirosov, R. M.; Avakian, V. V.; Karagjozian, G. V.; Mamidjanian, E. A.; Ovsepian, G. G.; Sokhoyan, S. O.

    1985-01-01

    Experimental results on the cross section of the single pion, proton and neutron inelastic interaction with carbon and lead nuclei in the 0.5 to 5.0 TeV energy interval obtained on the PION installation (Mount Aragats, Armenia, 3250 m) are presented. For this purpose the (N pi)/(N p) and inelastic (p Fe)/(pi Fe) ratios measured directly on the installation as well as the calculated inelastic (p A)/(pi A) dependence on the target nucleus atomic numbers were used.

  17. Stable semiconductor black phosphorus (BP)@titanium dioxide (TiO2) hybrid photocatalysts.

    PubMed

    Lee, Hyun Uk; Lee, Soon Chang; Won, Jonghan; Son, Byung-Chul; Choi, Saehae; Kim, Yooseok; Park, So Young; Kim, Hee-Sik; Lee, Young-Chul; Lee, Jouhahn

    2015-01-01

    Over the past few decades, two-dimensional (2D) and layered materials have emerged as new fields. Due to the zero-band-gap nature of graphene and the low photocatalytic performance of MoS2, more advanced semiconducting 2D materials have been prompted. As a result, semiconductor black phosphorus (BP) is a derived cutting-edge post-graphene contender for nanoelectrical application, because of its direct-band-gap nature. For the first time, we report on robust BP@TiO2 hybrid photocatalysts offering enhanced photocatalytic performance under light irradiation in environmental and biomedical fields, with negligible affected on temperature and pH conditions, as compared with MoS2@TiO2 prepared by the identical synthesis method. Remarkably, in contrast to pure few layered BP, which, due to its intrinsic sensitivity to oxygen and humidity was readily dissolved after just several uses, the BP@TiO2 hybrid photocatalysts showed a ~92% photocatalytic activity after 15 runs. Thus, metal-oxide-stabilized BP photocatalysts can be practically applied as a promising alternative to graphene and MoS2. PMID:25732720

  18. A BP neural network model for sea state recognition using laser altimeter

    NASA Astrophysics Data System (ADS)

    Shi, Chun-bo; Jia, Xiao-dong; Li, Sheng; Wang, Zhen

    2009-07-01

    A BP neural network method for the recognition of sea state in laser altimeter is presented in this paper. Sea wave is the typical stochastic disturbance factor of laser altimeter effecting on low-altitude defense penetration of the intelligent antiship missiles, the recognition of sea state is studied in order to satisfy the practical needs of flying over the ocean. The BP neural network fed with the feature vector of laser range-measurement presents the analysis of features and outputs the estimation result of sea state. The two most distinguishing features are the mean and the variance of the sea echo, which are extracted from the distance characteristics of sea echo using general theory of statistics. The use of a feedforward network trained with the back-propagation algorithm is also investigated. The BP neural network is trained using sample data set to the neural network, and then the BP neural network trained is tested to recognize the sea state waiting for the classification. The network output shows the recognition accuracy of the model can up to 88%, and the results of tests show that the BP neural network model for the recognition of sea state is feasible and effective.

  19. Targeting TopBP1 at a convergent point of multiple oncogenic pathways for cancer therapy

    PubMed Central

    Chowdhury, Pinki; Lin, Gregory E.; Liu, Kang; Song, Yongcheng; Lin, Fang-Tsyr; Lin, Weei-Chin

    2014-01-01

    The progression of many solid tumors is driven by de-regulation of multiple common pathways, particularly Rb, PI (3) K/Akt and p53. Prior studies identified TopBP1as a key mediator for the oncogenic gain-of-function activities of mutant p53 (mutp53) in cancer. In Akt-hyperactive cancer, TopBP1 forms oligomers and represses E2F1-dependent apoptosis. Here we perform a molecular docking screening and identify a lead compound, calcein, capable of blocking TopBP1 oligomerization and p53 binding, resulting in re-activation of E2F1-dependent apoptosis and blockade of mutp53 gain-of-function. Calcein AM, the cell permeable derivative of calcein, shows significant anti-tumor activity in a wide-spectrum of cultured cancer cells harboring high TopBP1 levels. These biochemical findings are recapitulated in breast cancer xenograft models. Thus, our study provides proof-of-concept evidence for targeting TopBP1, a convergent point of multiple pathways, as a cancer therapy. PMID:25400145

  20. Northern East Pacific Rise: Evolution from 25 m.y. B.P. to the present

    NASA Astrophysics Data System (ADS)

    Mammerickx, Jacqueline; Klitgord, Kim D.

    1982-08-01

    The northeast Pacific topography and magnetic lineations (25 m.y. B.P. to the Present) record the traces of three major spreading reorganizations. Only one spreading center is observed today, but there is evidence for several ephemeral episodes of twin spreading accompanying the evolution from an extensive Pacific-Guadalupe plate boundary to a much shortened Pacific-Cocos and Pacific-Rivera plate boundary. The 25 m.y. B.P. plate reorganization culminated with the formation of the Guadalupe plate, bound by the Murray fracture zone to the north and the Cocos-Nazca spreading ridge to the south. Between 25 and 12.5 m.y. B.P. spreading continued while the plate retained the same general outline. The 12.5-11 m.y. B.P. reorganization resulted in the creation of a much shortened Pacific-Cocos plate boundary located in its early stages over the Mathematician seamounts and a much reduced Cocos-plate. The last reorganizaton (6.5-3.5 m.y. B.P.) resulted in the abandonment of the Mathematician spreading ridge as a Pacific-Cocos plate boundary in favor of the East Pacific Rise.

  1. Stable semiconductor black phosphorus (BP)@titanium dioxide (TiO2) hybrid photocatalysts

    PubMed Central

    Uk Lee, Hyun; Lee, Soon Chang; Won, Jonghan; Son, Byung-Chul; Choi, Saehae; Kim, Yooseok; Park, So Young; Kim, Hee-Sik; Lee, Young-Chul; Lee, Jouhahn

    2015-01-01

    Over the past few decades, two-dimensional (2D) and layered materials have emerged as new fields. Due to the zero-band-gap nature of graphene and the low photocatalytic performance of MoS2, more advanced semiconducting 2D materials have been prompted. As a result, semiconductor black phosphorus (BP) is a derived cutting-edge post-graphene contender for nanoelectrical application, because of its direct-band-gap nature. For the first time, we report on robust BP@TiO2 hybrid photocatalysts offering enhanced photocatalytic performance under light irradiation in environmental and biomedical fields, with negligible affected on temperature and pH conditions, as compared with MoS2@TiO2 prepared by the identical synthesis method. Remarkably, in contrast to pure few layered BP, which, due to its intrinsic sensitivity to oxygen and humidity was readily dissolved after just several uses, the BP@TiO2 hybrid photocatalysts showed a ~92% photocatalytic activity after 15 runs. Thus, metal-oxide-stabilized BP photocatalysts can be practically applied as a promising alternative to graphene and MoS2. PMID:25732720

  2. HIV-1 Vpr increases HCV replication through VprBP in cell culture.

    PubMed

    Yan, Yanling; Huang, Fang; Yuan, Ting; Sun, Binlian; Yang, Rongge

    2016-09-01

    Coinfection of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) occurs at a high frequency, in which HIV shows a promotion of HCV-derived liver diseases. However, the mechanism of how this occurs is not well understood. Our previous work has demonstrated that the HIV-1 accessory protein Vpr enhances HCV RNA replication in cell culture. Because Vpr performs most of its functions through host protein VprBP (DCAF1), the role of VprBP in the regulation of HCV by Vpr was investigated in this study. We found that the Vpr mutant Q65R, which is deficient in VprBP binding, could not enhance HCV replication. Furthermore, Vpr-mediated enhancement of HCV replication was severely diminished in VprBP knockdown cells. In addition, an inhibitor of Cullin RING E3 ligases, MLN4924, impaired the function of Vpr during HCV replication. Together, these results suggest that Vpr promotes HCV replication in a VprBP-dependent manner, and that the activity of Cullin RING E3 ligases is essential to this process. In conclusion, our findings demonstrate that HIV-1 Vpr makes the cellular environment more suitable for HCV replication, which might relate with the host ubiquitination system. PMID:27460548

  3. A DNA target of 30 bp is sufficient for RNA-directed DNA methylation.

    PubMed

    Pélissier, T; Wassenegger, M

    2000-01-01

    In higher plants, RNA-DNA interactions can trigger de novo methylation of genomic sequences via a process that is termed RNA-directed DNA methylation (RdDM). In potato spindle tuber viroid (PSTVd)-infected tobacco plants, this process can potentially lead to methylation of all C residues at symmetrical and nonsymmetrical sites within chromosomal inserts that consist of multimers of the 359-bp-long PSTVd cDNA. Using PSTVd cDNA subfragments, we found that genomic targets with as few as 30 nt of sequence complementarity to the viroid RNA are detected and methylated. Genomic sequencing analyses of genome-integrated 30- and 60-bp-long PSTVd subfragments demonstrated that de novo cytosine methylation is not limited to the canonical CpG, CpNpG sites. Sixty-base-pair-long PSTVd cDNA constructs appeared to be densely methylated in nearly all tobacco leaf cells. With the 30-bp-long PSTVd-specific construct, the proportion of cells displaying dense transgene methylation was significantly reduced, suggesting that a minimal target size of about 30 bp is necessary for RdDM. The methylation patterns observed for two different 60-bp constructs further suggested that the sequence identity of the target may influence the methylation mechanism. Finally, a link between viroid pathogenicity and PSTVd RNA-directed methylation of host sequences is proposed. PMID:10668798

  4. 53BP1 deficiency combined with telomere dysfunction activates ATR-dependent DNA damage response.

    PubMed

    Martínez, Paula; Flores, Juana M; Blasco, Maria A

    2012-04-16

    TRF1 protects mammalian telomeres from fusion and fragility. Depletion of TRF1 leads to telomere fusions as well as accumulation of γ-H2AX foci and activation of both the ataxia telangiectasia mutated (ATM)- and the ataxia telangiectasia and Rad3 related (ATR)-mediated deoxyribonucleic acid (DNA) damage response (DDR) pathways. 53BP1, which is also present at dysfunctional telomeres, is a target of ATM that accumulates at DNA double-strand breaks and favors nonhomologous end-joining (NHEJ) repair over ATM-dependent resection and homology-directed repair (homologous recombination [HR]). To address the role of 53BP1 at dysfunctional telomeres, we generated mice lacking TRF1 and 53BP1. 53BP1 deficiency significantly rescued telomere fusions in mouse embryonic fibroblasts (MEFs) lacking TRF1, but they showed evidence of a switch from the NHEJ- to HR-mediated repair of uncapped telomeres. Concomitantly, double-mutant MEFs showed evidence of hyperactivation of the ATR-dependent DDR. In intact mice, combined 53BP1/TRF1 deficiency in stratified epithelia resulted in earlier onset of DNA damage and increased CHK1 phosphorylation during embryonic development, leading to aggravation of skin phenotypes. PMID:22508511

  5. HP1BP3 expression determines maternal behavior and offspring survival.

    PubMed

    Garfinkel, B P; Arad, S; Neuner, S M; Netser, S; Wagner, S; Kaczorowski, C C; Rosen, C J; Gal, M; Soreq, H; Orly, J

    2016-09-01

    Maternal care is an indispensable behavioral component necessary for survival and reproductive success in mammals, and postpartum maternal behavior is mediated by an incompletely understood complex interplay of signals including effects of epigenetic regulation. We approached this issue using our recently established mice with targeted deletion of heterochromatin protein 1 binding protein 3 (HP1BP3), which we found to be a novel epigenetic repressor with critical roles in postnatal growth. Here, we report a dramatic reduction in the survival of pups born to Hp1bp3(-/-) deficient mouse dams, which could be rescued by co-fostering with wild-type dams. Hp1bp3(-/-) females failed to retrieve both their own pups and foster pups in a pup retrieval test, and showed reduced anxiety-like behavior in the open-field and elevated-plus-maze tests. In contrast, Hp1bp3(-/-) females showed no deficits in behaviors often associated with impaired maternal care, including social behavior, depression, motor coordination and olfactory capability; and maintained unchanged anxiety-associated hallmarks such as cholinergic status and brain miRNA profiles. Collectively, our results suggest a novel role for HP1BP3 in regulating maternal and anxiety-related behavior in mice and call for exploring ways to manipulate this epigenetic process. PMID:27470444

  6. Regulation of PMP22 mRNA by G3BP1 affects cell proliferation in breast cancer cells

    PubMed Central

    2013-01-01

    Background Regulation of mRNAs is one way to control protein levels and thereby important cellular processes such as growth, invasion and apoptosis. G3BPs constitute a family of mRNA-binding proteins, shown to be overexpressed in several cancer types, including breast, colon and pancreas cancer. G3BP has been reported to both stabilize and induce degradation of specific mRNAs. Results Here, we show that G3BP1, but not G3BP2, supports proliferation of several breast cancer cell lines. Global gene expression analyses of G3BP1- and G3BP2-depleted cells indicate that primarily G3BP1, and much less G3BP2, influences mRNA expression levels. Peripheral myelin protein 22 (PMP22) was one gene that was significantly influenced by G3BP1 depletion which led to a 2–3 fold increased expression. Depletion of PMP22 resulted in increased proliferation and the G3BP1-mediated effect on proliferation was not seen upon PMP22-depletion. Conclusions This indicates a novel role for G3BP1 in the regulation of cell proliferation in breast cancer cells, perhaps via a regulatory effect on PMP22 expression. PMID:24321297

  7. CacyBP/SIP inhibits Doxourbicin-induced apoptosis of glioma cells due to activation of ERK1/2.

    PubMed

    Tang, Yuan; Zhan, Wenjian; Cao, Tong; Tang, Tianjin; Gao, Yong; Qiu, Zhichao; Fu, Chunling; Qian, Fengyuan; Yu, Rutong; Shi, Hengliang

    2016-03-01

    Calcyclin-binding protein or Siah-1-interacting protein (CacyBP/SIP) was previously reported to promote the proliferation of glioma cells. However, the effect of CacyBP/SIP on apoptosis of glioma is poorly understood. Here, our study shows that CacyBP/SIP plays a role in inhibiting doxorubicin (DOX) induced apoptosis of glioma cells U251 and U87. Overexpression of CacyBP/SIP obviously suppressed the DOX-induced cell apoptosis. On the contrary, silencing of CacyBP/SIP significantly promoted it. Further investigation indicated that inhibition of apoptosis by CacyBP/SIP was relevant to its nuclear translocation in response to the DOX treatment. Importantly, we found that the level of p-ERK1/2 in nuclei was related to the nuclear accumulation of CacyBP/SIP. Finally, the role of CacyBP/SIP was confirmed in vivo in a mouse model with the cell line stably silencing CacyBP/SIP. Taken together, our results suggest that CacyBP/SIP plays an important role in inhibiting apoptosis of glioma cells which might be mediated by ERK1/2 signaling pathway, which will provide some guidance for the treatment of glioma. PMID:26825673

  8. An Ethylene-responsive Factor BpERF11 Negatively Modulates Salt and Osmotic Tolerance in Betula platyphylla.

    PubMed

    Zhang, Wenhui; Yang, Guiyan; Mu, Dan; Li, Hongyan; Zang, Dandan; Xu, Hongyun; Zou, Xuezhong; Wang, Yucheng

    2016-01-01

    Ethylene responsive factors (ERFs) play important roles in the abiotic stress; however, only a few ERF genes from woody plants have been functionally characterized. In the present study, an ERF gene from Betula platyphylla (birch), BpERF11, was functionally characterized in response to abiotic stress. BpERF11 is a nuclear protein, which could specifically bind to GCC boxes and DRE motifs. BpERF11-overexpressing and BpERF11 RNA interference (RNAi) knockdown plants were generated for gain- and loss-of-function analysis. BpERF11 negatively regulates resistance to salt and severe osmotic stress, and the transgenic birch plants overexpressing BpERF11 shows increased electrolyte leakage and malondialdehyde (MDA) contents. BpERF11 inhibits the expression of an AtMYB61 homologous gene, resulting in increased stomatal aperture, which elevated the transpiration rate. Furthermore, BpERF11 downregulates the expression of P5CS, SOD and POD genes, but upregulates the expression of PRODH and P5CDH, which results in reduced proline levels and increased reactive oxygen species (ROS) accumulation. BpERF11 also significantly inhibits the expression of LEA and dehydrin genes that involve in abiotic stress tolerance. Therefore, BpERF11 serves as a transcription factor that negatively regulates salt and severe osmotic tolerance by modulating various physiological processes. PMID:26980058

  9. An Ethylene-responsive Factor BpERF11 Negatively Modulates Salt and Osmotic Tolerance in Betula platyphylla

    PubMed Central

    Zhang, Wenhui; Yang, Guiyan; Mu, Dan; Li, Hongyan; Zang, Dandan; Xu, Hongyun; Zou, Xuezhong; Wang, Yucheng

    2016-01-01

    Ethylene responsive factors (ERFs) play important roles in the abiotic stress; however, only a few ERF genes from woody plants have been functionally characterized. In the present study, an ERF gene from Betula platyphylla (birch), BpERF11, was functionally characterized in response to abiotic stress. BpERF11 is a nuclear protein, which could specifically bind to GCC boxes and DRE motifs. BpERF11-overexpressing and BpERF11 RNA interference (RNAi) knockdown plants were generated for gain- and loss-of-function analysis. BpERF11 negatively regulates resistance to salt and severe osmotic stress, and the transgenic birch plants overexpressing BpERF11 shows increased electrolyte leakage and malondialdehyde (MDA) contents. BpERF11 inhibits the expression of an AtMYB61 homologous gene, resulting in increased stomatal aperture, which elevated the transpiration rate. Furthermore, BpERF11 downregulates the expression of P5CS, SOD and POD genes, but upregulates the expression of PRODH and P5CDH, which results in reduced proline levels and increased reactive oxygen species (ROS) accumulation. BpERF11 also significantly inhibits the expression of LEA and dehydrin genes that involve in abiotic stress tolerance. Therefore, BpERF11 serves as a transcription factor that negatively regulates salt and severe osmotic tolerance by modulating various physiological processes. PMID:26980058

  10. Survey of the bp/tee genes from clinical group A streptococcus isolates in New Zealand - implications for vaccine development.

    PubMed

    Steemson, John D; Moreland, Nicole J; Williamson, Deborah; Morgan, Julie; Carter, Philip E; Proft, Thomas

    2014-12-01

    Group A streptococcus (GAS) is responsible for a wide range of diseases ranging from superficial infections, such as pharyngitis and impetigo, to life-threatening diseases, such as toxic shock syndrome and acute rheumatic fever (ARF). GAS pili are hair-like extensions protruding from the cell surface and consist of highly immunogenic structural proteins: the backbone pilin (BP) and one or two accessory pilins (AP1 and AP2). The protease-resistant BP builds the pilus shaft and has been recognized as the T-antigen, which forms the basis of a major serological typing scheme that is often used as a supplement to M typing. A previous sequence analysis of the bp gene (tee gene) in 39 GAS isolates revealed 15 different bp/tee types. In this study, we sequenced the bp/tee gene from 100 GAS isolates obtained from patients with pharyngitis, ARF or invasive disease in New Zealand. We found 20 new bp/tee alleles and four new bp/tee types/subtypes. No association between bp/tee type and clinical outcome was observed. We confirmed earlier reports that the emm type and tee type are associated strongly, but we also found exceptions, where multiple tee types could be found in certain M/emm type strains, such as M/emm89. We also reported, for the first time, the existence of a chimeric bp/tee allele, which was assigned into a new subclade (bp/tee3.1). A strong sequence conservation of the bp/tee gene was observed within the individual bp/tee types/subtypes (>97 % sequence identity), as well as between historical and contemporary New Zealand and international GAS strains. This temporal and geographical sequence stability provided further evidence for the potential use of the BP/T-antigen as a vaccine target. PMID:25190737

  11. Bone Marrow Transplantation Improves Autoinflammation and Inflammatory Bone Loss in SH3BP2 Knock-In Cherubism Mice

    PubMed Central

    Yoshitaka, Teruhito; Kittaka, Mizuho; Ishida, Shu; Mizuno, Noriyoshi; Mukai, Tomoyuki; Ueki, Yasuyoshi

    2014-01-01

    Cherubism (OMIM#118400) is a genetic disorder in children characterized by excessive jawbone destruction with proliferation of fibro-osseous lesions containing a large number of osteoclasts. Mutations in the SH3-domain binding protein 2 (SH3BP2) are responsible for cherubism. Analysis of the knock-in (KI) mouse model of cherubism showed that homozygous cherubism mice (Sh3bp2KI/KI) spontaneously develop systemic autoinflammation and inflammatory bone loss and that cherubism is a TNF-α-dependent hematopoietic disorder. In this study, we investigated whether bone marrow transplantation (BMT) is effective for the treatment of inflammation and bone loss in Sh3bp2KI/KI mice. Bone marrow (BM) cells from wild-type (Sh3bp2+/+) mice were transplanted to 6-week-old Sh3bp2KI/KI mice with developing inflammation and to 10-week-old Sh3bp2KI/KI mice with established inflammation. Six-week-old Sh3bp2KI/KI mice transplanted with Sh3bp2+/+ BM cells exhibited improved body weight loss, facial swelling, and survival rate. Inflammatory lesions in the liver and lung as well as bone loss in calvaria and mandibula were ameliorated at 10 weeks after BMT compared to Sh3bp2KI/KI mice transplanted with Sh3bp2KI/KI BM cells. Elevation of serum TNF-α levels was not detected after BMT. BMT was effective for up to 20 weeks in 6-week-old Sh3bp2KI/KI mice transplanted with Sh3bp2+/+ BM cells. BMT also ameliorated the inflammation and bone loss in 10-week-old Sh3bp2KI/KI mice. Thus our study demonstrates that BMT improves the inflammation and bone loss in cherubism mice. BMT may be effective for the treatment of cherubism patients. PMID:25445458

  12. Lake level changes in Hala Lake(NW China) based on ostracodassemblages during the LGM and Post-LGM

    NASA Astrophysics Data System (ADS)

    Yan, D.; Wuennemann, B.

    2012-12-01

    The Hala Lake, located in the Qilian Mountains, Qinghai Province, China, at 4078 m a.s.l. may archive in its sediments hydrological and climate changes during the Late Quaternary time, as it is close to the area impacted by the East-Asian Summer monsoon and westerly-driven air masses. Based on the sediment core H7, which was taken in the center of the lake at 65m water depth,ostracod assemblages and stable isotopes from ostracode shells were investigated in details. Three main species were found, which are common species in high altitude saline lakes of the Tibetan Plateau: Leucocythere sp.,Limnocythereinopinata and Eucypris sp.They started to occur in deeper part of H7,indicating an early onset of favorable living conditions during the LGM and post-LGM periods. Besides, algae occurred between 25 and 32m water depth. According to the unevenly distributed amount of ostracods and oxygen isotope data, our results indicate important lake level changes during the global LGM and Lateglacial. The lake experienced lowest levels of 25-50 m below the present water line. Ostracods disappeared with the onset of the early Holocene.A stepwise refilling started already at ca. 16 kyr BP and reached -25 m level during the Bølling/Allerød warm phase at ca. 13.5 kyr BP.Latest at ca.7.6 kyr BP, the lake reached a stable highstand similar to the present level until ca.6 kyr BPas . The subsequent lake development remains unclear due to strong mismatches of the data but may indicate a general trend to deteriorating conditions and lake level lowstands at ca. 5.0-4.2, 2.0 and at around 0.5 kyr BP.; Ostracods Distribution in H2 ; Ostracods plate in Hala lake

  13. A Study of the Mechanisms of Attachment of Allergised Lymphocytes to BP8 Ascites Tumour Cells

    PubMed Central

    Lee, P. J.; Cater, D. B.

    1969-01-01

    The attachment of allergised and non-allergised lymph-node cells from C57B1 mice to BP8 ascites tumour cells were compared in vitro in the presence of vaso-active agents and mediators of the inflammatory reaction. It was found that Priscol, noradrenaline, adrenaline, 5-HT and histamine caused some cell adherence, while bradykinin and lysolecithin caused a marked increase of adherence of the allergised lymph-node cells to the BP8 cells. Electrophoretic studies of BP8 cells in the presence of polyornithine showed an abolition of the anodic mobility. Theories of action of the various agents are discussed. ImagesFigs. 5-8Figs. 1-4 PMID:5364386

  14. Crystal and molecular structure of the coordination compounds of Er3+ with 1-(methoxydiphenylphosphoryl)-2-diphenylphosphorylbenzene [Er L {2/1}(NO3)2]2[Er(NO3)2(H2O)5]0.333(NO3)2.333 · 2.833H2O and its ethyl substituted derivative [Er L {2/2}(NO3)2][Er(NO3)5]0.5 · 0.5H2O

    NASA Astrophysics Data System (ADS)

    Polyakova, I. N.; Baulin, V. E.; Ivanova, I. S.; Pyatova, E. N.; Sergienko, V. S.; Tsivadze, A. Yu.

    2015-01-01

    The coordination compounds of Er3+ with 1-(methoxydiphenylphosphoryl)-2-diphenylphosphorylbenzene [Er L {2/1}(NO3)2]2[Er(NO3)2(H2O)5]0.333(NO3)2.333 · 2.833H2O ( I) and its ethyl substituted derivative [Er L {2/2}(NO3)2][Er(NO3)5]0.5 · 0.5H2O ( II) are synthesized and their crystal structures are studied. I and II contain [Er L 2(NO3)2]+ complex cations of identical composition and close structure. The eight-vertex polyhedron of the Er atom in the shape of a distorted octahedron with two split trans vertices is formed by the O atoms of the phosphoryl groups of L ligands and nitrate anions. L ligands close nine-membered metallocycles. The structures contain spacious channels which are populated differently, namely, by disordered [Er(NO3)2(H2O)5]+ complex cations, NO{3/-} anions, and crystallization water molecules in I and disordered [Er(NO3)5]2- complex anions and crystallization water molecules in II. The IR spectra of I and II are studied.

  15. Optical and mechanical behavior of GeC and BP antireflection coatings under rain erosion tests

    NASA Astrophysics Data System (ADS)

    Mackowski, Jean-Marie; Cimma, B.; Lacuve, J.; Laprat, Patrice

    1994-09-01

    Thick germanium carbide (GeC) and boron phosphide (BP) films are successfully grown on various zinc sulfide and germanium substrates at temperatures up to 450 degree(s)C by reactive radio-frequency sputtering (RRFS). The sputtering conditions are respectively a germanium target within a medium of methane-argon for GeC films and a high density boron target in a sputtering medium of phosphine-argon for BP films. The rain erosion resistance of GeC and BP films protected or not by diamond-like carbon (DLC) coating on top are measured for water drop diameter of 1.2 mm or 2 mm with an impact velocity ranging from 210 m/s to 265 m/s on the Saab-Scania whirling-arm rig facilities (Linkoping, Sweden). Rain erosion resistance of BP films for a wavelength band in the 8 micrometers to 10 micrometers range shows no damage for a speed up to 250 m/s with an exposure time up to 10 min, whereas the GeC rain erosion resistance shows no damage up to 235 m/s for the same exposure time. The transmission of each film is well correlated to its optical absorption at 10.6 micrometers . The GeC absorption can be reduced down to 40 cm-1 whereas the BP absorption stays around 220 cm-1 for sputtered films. So the compromise between the optical performance and the rain erosion resistance can be achieved by the use of GeC or BP films.

  16. Environmental change in the Limfjord, Denmark (ca 7500-1500 cal yrs BP): a multiproxy study

    NASA Astrophysics Data System (ADS)

    Lewis, Jonathan P.; Ryves, David B.; Rasmussen, Peter; Knudsen, Karen L.; Petersen, Kaj S.; Olsen, Jesper; Leng, Melanie J.; Kristensen, Peter; McGowan, Suzanne; Philippsen, Bente

    2013-10-01

    The Limfjord region of northern Jutland, Denmark, supports a rich archaeological record dating back to the Mesolithic, which documents long-term change in human practices and utilisation of marine resources since approximately 7500 BP. The presence and availability of marine resources in the Limfjord is sensitively regulated by environmental parameters such as salinity, sedimentary regime, nutrient status and primary productivity, but long-term changes in these parameters are currently poorly understood. In this study a multiproxy approach (including sedimentary parameters, diatoms, molluscs, foraminifera, sedimentary pigments, C and O stable isotopes and plant macrofossils) has been adopted to assess environmental change over the period ca 7500-1500 cal yrs BP at Kilen, a coastal fjord (before AD 1856) situated in the Western Limfjord. A diatom-based salinity transfer function based on a pan-Baltic training set has been applied to the fossil diatom dataset for quantitative assessment of salinity change over the study period. This study demonstrates that large-scale shifts in salinity are a common feature of the Limfjord's long-term history and are driven by the level of connection with the North Sea and the Skagerrak respectively, which in turn is likely driven by the complex interplay between climate, sea-level change, current velocity and rates of erosion/sedimentary accretion. Three shifts in state at Kilen are identified over the study period: a deep, periodically stratified fjord with medium-high salinity (and high productivity) between ca 7500-5000 BP, followed by a gradual transition to a shallow benthic system with more oceanic conditions (i.e. higher salinity, lower productivity, slower sedimentary accumulation rate and poorer fossil preservation) after ca 5000 BP and no stratification after ca 4400 BP, and lastly, within this shallow phase, an abrupt shift to brackish conditions around 2000 BP. Environmental-societal interactions are discussed on the

  17. The structural basis of modified nucleosome recognition by 53BP1.

    PubMed

    Wilson, Marcus D; Benlekbir, Samir; Fradet-Turcotte, Amélie; Sherker, Alana; Julien, Jean-Philippe; McEwan, Andrea; Noordermeer, Sylvie M; Sicheri, Frank; Rubinstein, John L; Durocher, Daniel

    2016-08-01

    DNA double-strand breaks (DSBs) elicit a histone modification cascade that controls DNA repair. This pathway involves the sequential ubiquitination of histones H1 and H2A by the E3 ubiquitin ligases RNF8 and RNF168, respectively. RNF168 ubiquitinates H2A on lysine 13 and lysine 15 (refs 7, 8) (yielding H2AK13ub and H2AK15ub, respectively), an event that triggers the recruitment of 53BP1 (also known as TP53BP1) to chromatin flanking DSBs. 53BP1 binds specifically to H2AK15ub-containing nucleosomes through a peptide segment termed the ubiquitination-dependent recruitment motif (UDR), which requires the simultaneous engagement of histone H4 lysine 20 dimethylation (H4K20me2) by its tandem Tudor domain. How 53BP1 interacts with these two histone marks in the nucleosomal context, how it recognizes ubiquitin, and how it discriminates between H2AK13ub and H2AK15ub is unknown. Here we present the electron cryomicroscopy (cryo-EM) structure of a dimerized human 53BP1 fragment bound to a H4K20me2-containing and H2AK15ub-containing nucleosome core particle (NCP-ubme) at 4.5 Å resolution. The structure reveals that H4K20me2 and H2AK15ub recognition involves intimate contacts with multiple nucleosomal elements including the acidic patch. Ubiquitin recognition by 53BP1 is unusual and involves the sandwiching of the UDR segment between ubiquitin and the NCP surface. The selectivity for H2AK15ub is imparted by two arginine fingers in the H2A amino-terminal tail, which straddle the nucleosomal DNA and serve to position ubiquitin over the NCP-bound UDR segment. The structure of the complex between NCP-ubme and 53BP1 reveals the basis of 53BP1 recruitment to DSB sites and illuminates how combinations of histone marks and nucleosomal elements cooperate to produce highly specific chromatin responses, such as those elicited following chromosome breaks. PMID:27462807

  18. NotCal04 - Comparison / Calibration 14C records 26-50 cal kBP

    SciTech Connect

    der Plicht, J v; Beck, J; Bard, E; Baille, M

    2004-11-11

    The radiocarbon calibration curve, IntCal04, extends back to 26 cal kBP. While several high resolution records exist beyond this limit, these data sets exhibit discrepancies one to another of up to several millennia. As a result, no calibration curve for the time range 26-50 cal kBP can be recommended as yet, but in this paper the IntCal04 working group compares the available data sets and offers a discussion of the information that they hold.

  19. Mitochondrial intergenic COII/tRNA(Lys) 9-bp deletion, a biomarker for hepatocellular carcinoma?

    PubMed

    Ren, Weihua; Li, Yawei; Li, Rui; Feng, Hongbo; Wu, Shuangting; Mao, Yuhui; Huang, Lei

    2016-07-01

    The COII/tRNA(Lys) intergenic 9-bp deletion is one of the most commonly studied human mitochondrial DNA (mtDNA) polymorphisms. It consists of the loss of one of two tandemly repeated copies of the sequence CCCCCTCTA from a non-coding region located between cytochrome oxidase II (COII) and tRNA(Lys) gene. Most recently, case-control studies have shown a positive association between this deletion with hepatocellular cancer. In this study, we first performed a detailed analysis between this deletion and clinical diseases; moreover, we took the phylogenetic approach to examine the pathogenicity status of 9-bp deletion. PMID:26017042

  20. Placement of the GaBP ring system in the banded gastric bypass operation.

    PubMed

    Fobi, Mathias A L

    2005-09-01

    Currently, bariatric surgeons fashion the band or ring reinforcement prosthesis, to control the stoma in the vertical banded gastroplasty and gastric bypass operations for morbid obesity. To meet this need, the GaBP Ring system has been developed in various sizes, and consists of 4 main parts to provide a means for inserting a ring around the gastric pouch in the banded gastric bypass or the vertical banded gastroplasty. The pre-manufactured and sterilized device provides for better standardization and quality control than individually surgeon-fashioned devices. The GaBP Ring system is described, and the technique of placement and the pertinent initial clinical results are presented. PMID:16197796

  1. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.

    PubMed

    Chen, F H; Dong, G H; Zhang, D J; Liu, X Y; Jia, X; An, C B; Ma, M M; Xie, Y W; Barton, L; Ren, X Y; Zhao, Z J; Wu, X H; Jones, M K

    2015-01-16

    Our understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene. PMID:25593179

  2. Solution NMR Structure of the Ca2+-bound N-terminal Domain of CaBP7

    PubMed Central

    McCue, Hannah V.; Patel, Pryank; Herbert, Andrew P.; Lian, Lu-Yun; Burgoyne, Robert D.; Haynes, Lee P.

    2012-01-01

    Calcium-binding protein 7 (CaBP7) is a member of the calmodulin (CaM) superfamily that harbors two high affinity EF-hand motifs and a C-terminal transmembrane domain. CaBP7 has been previously shown to interact with and modulate phosphatidylinositol 4-kinase III-β (PI4KIIIβ) activity in in vitro assays and affects vesicle transport in neurons when overexpressed. Here we show that the N-terminal domain (NTD) of CaBP7 is sufficient to mediate the interaction of CaBP7 with PI4KIIIβ. CaBP7 NTD encompasses the two high affinity Ca2+ binding sites, and structural characterization through multiangle light scattering, circular dichroism, and NMR reveals unique properties for this domain. CaBP7 NTD binds specifically to Ca2+ but not Mg2+ and undergoes significant conformational changes in both secondary and tertiary structure upon Ca2+ binding. The Ca2+-bound form of CaBP7 NTD is monomeric and exhibits an open conformation similar to that of CaM. Ca2+-bound CaBP7 NTD has a solvent-exposed hydrophobic surface that is more expansive than observed in CaM or CaBP1. Within this hydrophobic pocket, there is a significant reduction in the number of methionine residues that are conserved in CaM and CaBP1 and shown to be important for target recognition. In CaBP7 NTD, these residues are replaced with isoleucine and leucine residues with branched side chains that are intrinsically more rigid than the flexible methionine side chain. We propose that these differences in surface hydrophobicity, charge, and methionine content may be important in determining highly specific interactions of CaBP7 with target proteins, such as PI4KIIIβ. PMID:22989873

  3. Synthesis of n-type boron phosphide films and formation of Schottky diode: Al/n-BP/Sb

    NASA Astrophysics Data System (ADS)

    Dalui, S.; Pal, A. K.

    2008-03-01

    Phosphorous rich BP in thin film form was deposited onto fused silica substrates by co-evaporating boron (99.99%) and phosphorous (99.995%) from a tantalum boat and indirectly heated alumina crucible, respectively. Schottky diode structures for n-type BP (Al/n-BP/Sb) were fabricated out of these films. Corresponding current-voltage and capacitance-voltage characteristics of the Schottky diodes were recorded and analyzed in the light of the existing theories.

  4. Enhancement of spin polarization via Fermi level tuning in Co{sub 2}MnSn{sub 1−x}Sb{sub x} (x = 0, 0.25. 0.5, 0.75, 1) Heusler alloys

    SciTech Connect

    Singh, Mukhtiyar Thakur, Jyoti; Kashyap, Manish K.; Saini, Hardev S.

    2014-04-24

    Full potential approach has been employed to tune Fermi level in Co{sub 2}MnSn{sub 1−x}Sb{sub x} (x = 0, 0.25, 0.5, 0.75, 1) Heulser alloys for enhancement of spin polarization and finding signature of half metallicity. Present density functional theory (DFT) based calculation indicates that stoichoimetric Heusler alloy, Co{sub 2}MnSn is not a half-metallic ferromagnet but the doping of Sb in it results in the shifting of E{sup F} in well-defined energy gap which leads the 100% spin polarization in the resultant alloys. The magnetism in present alloys is governed by localized moment on Mn atom mainly. The tuning of half-metallicity using doping can be proved as an ideal technique to search the new materials which can accomplish the need of spintronics.

  5. Fragment-mass, kinetic energy, and angular distributions for 234U(n ,f ) at incident neutron energies from En=0.2 MeV to 5.0 MeV

    NASA Astrophysics Data System (ADS)

    Al-Adili, A.; Hambsch, F.-J.; Pomp, S.; Oberstedt, S.; Vidali, M.

    2016-03-01

    This work investigates the neutron-induced fission of 234U and the fission-fragment properties for neutron energies between En=0.2 and 5.0 MeV with a special highlight on the prominent vibrational resonance at En=0.77 MeV. Angular, energy, and mass distributions were determined based on the double-energy technique by means of a twin Frisch-grid ionization chamber. The experimental data are parametrized in terms of fission modes based on the multimodal random neck-rupture model. The main results are a verified strong angular anisotropy and fluctuations in the energy release as a function of incident-neutron energy.

  6. Influence of 2mol% Na/Bi excess on multiferroic properties of (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 lead free system

    NASA Astrophysics Data System (ADS)

    Parmar, Kusum; Sharma, Hakikat; Kotnala, R. K.; Negi, N. S.

    2016-05-01

    Lead free (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 (NBLTF) system has been synthesized by sol gel method without and with 2 mol% excess of Na and Bi. X-ray diffraction patterns of NBLTF samples confirm perovskite structure having rhombohedral R3c phase symmetry. Metal oxide band observed at ~ 629 cm-1 wavnumber in FTIR spectra also confirm formation of perovskite phase in samples. Microstructural analysis exhibits dense crystal growth having better grains connectivity for NBLTF sample with 2 mol% excess Na/Bi which is supported by room temperature DC resistivity measurements. Dense crystal growth and low leakage current with 2 mol% excess Na/Bi is reported to improve multiferroic properties of NBLTF sample and provides new insight to explore single phase lead free multiferroic system.

  7. Relaxation of magnetoresistance of single-crystalline (La0.5Eu0.5)0.7Pb0.3MnO3 in a pulsed magnetic field

    NASA Astrophysics Data System (ADS)

    Bykov, A. A.; Popkov, S. I.; Shaykhutdinov, K. A.; Sablina, K. A.

    2012-12-01

    The magnetoresistance (MR) of substituted lanthanum manganite (La0.5Eu0.5)0.7Pb0.3MnO3 has been measured in a pulsed magnetic field with amplitude H = 250 kOe at various temperatures. It is established that temperature dependence of the MR relaxation parameter τ( T) is correlated with temperature dependence of the electric resistance R( T). A mechanism of relaxation is proposed that is related to the relaxation of conducting and dielectric phases in the volume of a sample under the conditions of phase separation. It is shown that the behavior of τ is related to the number of phase boundaries in the volume.

  8. Magnetization reversal properties of Pr{sub 1-x}(Gd/Nd){sub x}MnO{sub 3} (x=0.3, 0.5, 0.7)

    SciTech Connect

    Biswas, Sanjay; Pal, Sudipta; Bose, Esa

    2015-06-24

    We report measurements of the temperature dependent magnetic properties of single phase orthorhombic perovskites system associated with space group Pbnm compounds Pr{sub 1-x}(Gd/Nd){sub x}MnO{sub 3} (x=0.3, 0.5, 0.7). Magnetic properties radically changes with the doping of Gd or Nd. A magnetization reversal is observed below the Neel temperature (T{sub N}), in DC magnetization measurements (at 50 Oe) in the doped compounds. The reversal of magnetization may be due to the antiparallel coupling between the two magnetic sublattices (|Pr+ Gd/ Nd | and Mn). The hysteresis plot taken at 50K indicates a ferrimagnetic characteristic and existence of spin canting of ions in the magnetic sublattices.

  9. Dielectric and piezoelectric properties of CeO2-added nonstoichiometric (Na0.5K0.5)0.97(Nb0.96Sb0.04)O3 ceramics for piezoelectric energy harvesting device applications.

    PubMed

    Oh, Youngkwang; Noh, Jungrae; Yoo, Juhyun; Kang, Jinhee; Hwang, Larkhoon; Hong, Jaeil

    2011-09-01

    In this study, nonstoichiometric (Na(0.5)K(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics were fabricated and their dielectric and piezoelectric properties were investigated according to the CeO(2) addition. In this ceramic composition, CeO(2) addition improved sinterability, electromechanical coupling factor k(p), mechanical quality factor Q(m), piezoelectric constant d(33), and g(33). At the sintering temperature of 1100°C, for the 0.2wt% CeO(2) added specimen, the optimum values of density = 4.359 g/cm(3), k(p) = 0.443, Q(m) = 588, ε(r) = 444, d(33) = 159 pC/N, and g(33) = 35 × 10(-3) V·m/N, were obtained. A piezoelectric energy harvesting device using 0.2 wt% CeO(2)- added lead-free (K(0.5)Na(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics and a rectifying circuit for energy harvesting were fabricated and their electrical characteristics were investigated. Under an external vibration acceleration of 0.7 g, when the mass, the frequency of vibration generator, and matching load resistance were 2.4 g, 70 Hz, and 721 Ω, respectively, output voltage and power of piezoelectric harvesting device indicated the optimum values of 24.6 mV(rms) and 0.839 μW, respectively-suitable for application as the electric power source of a ubiquitous sensor network (USN) sensor node. PMID:21937318

  10. Removal of 2-ClBP from soil-water system using activated carbon supported nanoscale zerovalent iron.

    PubMed

    Zhang, Wei; Yu, Tian; Han, Xiaolin; Ying, Weichi

    2016-09-01

    We explored the feasibility and removal mechanism of removing 2-chlorobiphenyl (2-ClBP) from soil-water system using granular activated carbon (GAC) impregnated with nanoscale zerovalent iron (reactive activated carbon or RAC). The RAC samples were successfully synthesized by the liquid precipitation method. The mesoporous GAC based RAC with low iron content (1.32%) exhibited higher 2-ClBP removal efficiency (54.6%) in the water phase. The result of Langmuir-Hinshelwood kinetic model implied that the different molecular structures between 2-ClBP and trichloroethylene (TCE) resulted in more difference in dechlorination reaction rates on RAC than adsorption capacities. Compared to removing 2-ClBP in the water phase, RAC removed the 2-ClBP more slowly in the soil phase due to the significant external mass transfer resistance. However, in the soil phase, a better removal capacity of RAC was observed than its base GAC because the chemical dechlorination played a more important role in total removal process for 2-ClBP. This important result verified the effectiveness of RAC for removing 2-ClBP in the soil phase. Although reducing the total RAC removal rate of 2-ClBP, soil organic matter (SOM), especially the soft carbon, also served as an electron transfer medium to promote the dechlorination of 2-ClBP in the long term. PMID:27593281

  11. TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells

    PubMed Central

    Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob

    2015-01-01

    Genome integrity is critically dependent on timely DNA replication and accurate chromosome segregation. Replication stress delays replication into G2/M, which in turn impairs proper chromosome segregation and inflicts DNA damage on the daughter cells. Here we show that TopBP1 forms foci upon mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin recruitment of SLX4 and by facilitating unscheduled DNA synthesis. PMID:26283799

  12. SCYL1BP1 modulates neurite outgrowth and regeneration by regulating the Mdm2/p53 pathway

    PubMed Central

    Liu, Yonghua; Chen, Ying; Lu, Xiang; Wang, Youhua; Duan, Yinong; Cheng, Chun; Shen, Aiguo

    2012-01-01

    SCY1-like 1–binding protein 1 (SCYL1BP1) is a newly identified transcriptional activator domain containing a protein with many unknown biological functions. Recently emerging evidence has revealed that it is a novel regulator of the p53 pathway, which is required for neurite outgrowth and regeneration. Here we present evidence that SCYL1BP1 inhibits nerve growth factor–mediated neurite outgrowth in PC12 cells and affects morphogenesis of primary cortical neurons by strongly decreasing the p53 protein level in vitro, all of which depends on SCYL1BP1's transcriptional activator domain. Exogenous p53 rescues neurite outgrowth and neuronal morphogenesis defects caused by SCYL1BP1. Furthermore, SCYL1BP1 can directly induce Mdm2 transcription, whereas inhibiting the function of Mdm2 by specific small interfering RNAs results in partial rescue of neurite outgrowth and neuronal morphogenesis defects induced by SCYL1BP1. In vivo experiments show that SCYL1BP1 can also depress axonal regeneration, whereas inhibiting the function of SCYL1BP1 by specific short hairpin RNA enhances it. Taken together, these data strongly suggested that SCYL1BP1 is a novel transcriptional activator in neurite outgrowth by directly modulating the Mdm2/p53-dependent pathway, which might play an important role in CNS development and axonal regeneration after injury. PMID:23051735

  13. Genome-wide profiles of CtBP link metabolism with genome stability and epithelial reprogramming in breast cancer

    PubMed Central

    Di, Li-Jun; Byun, Jung S.; Wong, Madeline M.; Wakano, Clay; Taylor, Tara; Bilke, Sven; Baek, Songjoon; Hunter, Kent; Yang, Howard; Lee, Maxwell; Zvosec, Celia; Khramtsova, Galina; Cheng, Fan; Perou, Charles M.; Miller, C. Ryan; Raab, Rachel; Olopade, Olufunmilayo I.; Gardner, Kevin

    2013-01-01

    The C-terminal binding protein (CtBP) is a NADH-dependent transcriptional repressor that links carbohydrate metabolism to epigenetic regulation by recruiting diverse histone modifying complexes to chromatin. Here, global profiling of CtBP in breast cancer cells reveals that it drives epithelial to mesenchymal transition, stem cell pathways, and genome instability. CtBP expression induces mesenchymal and stem cell-like features while CtBP depletion or caloric restriction reverses gene repression and increases DNA repair. Multiple members of the CtBP-targeted gene network are selectively down-regulated in aggressive breast cancer subtypes. Differential expression of CtBP-targeted genes predicts poor clinical outcome in breast cancer patients, and elevated levels of CtBP in patient tumors predict shorter median survival. Finally, both CtBP promoter targeting and gene repression can be reversed by small molecule inhibition. These findings define broad roles for CtBP in breast cancer biology and suggest novel chromatin-based strategies for pharmacologic and metabolic intervention in cancer. PMID:23385593

  14. Investigation of crystal structure and associated electronic structure of Sr 6BP 5O 20

    NASA Astrophysics Data System (ADS)

    Ehrenberg, Helmut; Laubach, Sonja; Schmidt, P. C.; McSweeney, R.; Knapp, M.; Mishra, K. C.

    2006-04-01

    Strontium borophosphate phosphate (Sr 6BP 5O 20, SrBP), activated by divalent europium ions is a bluish-green phosphor emitting in a broad band with the emission peak near 480 nm. In this paper, we report the crystal structure of SrBP determined from an analysis of the X-ray diffraction pattern of a prismatic single crystal (size 60 μm×50 μm×40 μm). This crystal was chosen from undoped phosphor powder samples prepared for this purpose by solid-state reaction. SrBP is observed to crystallize in a body-centered tetragonal lattice with the lattice parameters a=9.7895(7) Å and c=19.032(3) Å, the associated space group being I4¯c2 (space group 120). Using the structural data from this study, we have also calculated its electronic structure using the augmented spherical wave method and the local density approximation (LDA). We show the ordering of the electronic states by the density of states (DOS) and the partial DOS plots. The LDA gives a direct optical band gap at the Γ point of about 5 eV. The significance of the crystal structure and associated electronic structure is discussed with respect to maintenance of this phosphor in Hg-discharge lamps.

  15. 78 FR 76851 - Agency Information Collection Activities: BP Regulations Pertaining to Customs Brokers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: BP Regulations Pertaining to Customs Brokers AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland... requirement concerning the CBP Regulations Pertaining to Customs Brokers (19 CFR Part 111). This request...

  16. Characterization of the Particulate Emissions from the BP Deepwater Horizon Surface Oil Burns

    EPA Science Inventory

    Opportunistic particle samples were gathered from the sail of a tethered aerostat during at-sea plume sampling of the purposely-burned surface oil during the BP Deepwater Horizon disaster in the Gulf of Mexico. Particles were analyzed for polycyclic aromatic hydrocarbons (PAHs),...

  17. [Estimation of Winter Wheat Biomass Using Visible Spectral and BP Based Artificial Neural Networks].

    PubMed

    Cui, Ri-xian; Liu, Ya-dong; Fu, Jin-dong

    2015-09-01

    The objective of this study was to evaluate the feasibility of using color digital image analysis and back propagation (BP) based artificial neural networks (ANN) method to estimate above ground biomass at the canopy level of winter wheat field. Digital color images of winter wheat canopies grown under six levels of nitrogen treatments were taken with a digital camera for four times during the elongation stage and at the same time wheat plants were sampled to measure above ground biomass. Canopy cover (CC) and 10 color indices were calculated from winter wheat canopy images by using image analysis program (developed in Microsoft Visual Basic). Correlation analysis was carried out to identify the relationship between CC, 10 color indices and winter wheat above ground biomass. Stepwise multiple linear regression and BP based ANN methods were used to establish the models to estimate winter wheat above ground biomass. The results showed that CC, and two color indices had a significant cor- relation with above ground biomass. CC revealed the highest correlation with winter wheat above ground biomass. Stepwise multiple linear regression model constituting CC and color indices of NDI and b, and BP based ANN model with four variables (CC, g, b and NDI) for input was constructed to estimate winter wheat above ground biomass. The validation results indicate that the model using BP based ANN method has a better performance with higher R2 (0.903) and lower RMSE (61.706) and RRMSE (18.876) in comparation with the stepwise regression model. PMID:26669174

  18. SH3BP2 is an activator of NFAT activity and osteoclastogenesis

    SciTech Connect

    Lietman, Steven A. Yin Lihong; Levine, Michael A.

    2008-07-11

    Heterozygous activating mutations in exon 9 of SH3BP2 have been found in most patients with cherubism, an unusual genetic syndrome characterized by excessive remodeling of the mandible and maxilla due to spontaneous and excessive osteoclastic bone resorption. Osteoclasts differentiate after binding of sRANKL to RANK induces a number of downstream signaling effects, including activation of the calcineurin/NFAT (nuclear factor of activated T cells) pathway. Here, we have investigated the functional significance of SH3BP2 protein on osteoclastogenesis in the presence of sRANKL. Our results indicate that SH3BP2 both increases nuclear NFATc1 in sRANKL treated RAW 264.7 preosteoclast cells and enhances expression of tartrate resistant acid phosphatase (TRAP), a specific marker of osteoclast differentiation. Moreover, overexpression of SH3BP2 in RAW 264.7 cells potentiates sRANKL-stimulated phosphorylation of PLC{gamma}1 and 2, thus providing a mechanistic pathway for the rapid translocation of NFATc1 into the nucleus and increased osteoclastogenesis in cherubism.

  19. Finished Annotated Genome Sequence of Burkholderia pseudomallei Strain Bp1651, a Multidrug-Resistant Clinical Isolate

    PubMed Central

    Sue, David; Hakovirta, Janetta; Loparev, Vladimir N.; Knipe, Kristen; Sammons, Scott A.; Ranganathan-Ganakammal, Satishkumar; Changayil, Shankar; Srinivasamoorthy, Ganesh; Weil, Michael R.; Tatusov, Roman L.; Gee, Jay E.; Elrod, Mindy G.; Hoffmaster, Alex R.; Weigel, Linda M.

    2015-01-01

    Burkholderia pseudomallei strain Bp1651, a human isolate, is resistant to all clinically relevant antibiotics. We report here on the finished genome sequence assembly and annotation of the two chromosomes of this strain. This genome sequence may assist in understanding the mechanisms of antimicrobial resistance for this pathogenic species. PMID:26634765

  20. 2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING BUILDING, AND POWER SUBSTATION - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  1. Inhibition of HIF-1{alpha} activity by BP-1 ameliorates adjuvant induced arthritis in rats

    SciTech Connect

    Shankar, J.; Thippegowda, P.B.; Kanum, S.A.

    2009-09-18

    Rheumatoid arthritis (RA) is a chronic inflammatory, angiogenic disease. Inflamed synovitis is a hallmark of RA which is hypoxic in nature. Vascular endothelial growth factor (VEGF), one of the key regulators of angiogenesis, is overexpressed in the pathogenesis of RA. VEGF expression is regulated by hypoxia-inducible factor-1{alpha} (HIF-1{alpha}), a master regulator of homeostasis which plays a pivotal role in hypoxia-induced angiogenesis. In this study we show that synthetic benzophenone analogue, 2-benzoyl-phenoxy acetamide (BP-1) can act as a novel anti-arthritic agent in an experimental adjuvant induced arthritis (AIA) rat model by targeting VEGF and HIF-1{alpha}. BP-1 administered hypoxic endothelial cells and arthritic animals clearly showed down regulation of VEGF expression. Further, BP-1 inhibits nuclear translocation of HIF-1{alpha}, which in turn suppresses transcription of the VEGF gene. These results suggest a further possible clinical application of the BP-1 derivative as an anti-arthritic agent in association with conventional chemotherapeutic agents.

  2. FOXO/4E-BP Signaling in Drosophila Muscles Regulates Organism-wide Proteostasis During Aging

    PubMed Central

    Demontis, Fabio; Perrimon, Norbert

    2011-01-01

    SUMMARY The progressive loss of muscle strength during aging is a common degenerative event of unclear pathogenesis. Although muscle functional decline precedes age-related changes in other tissues, its contribution to systemic aging is unknown. Here, we show that muscle aging is characterized in Drosophila by the progressive accumulation of protein aggregates that associate with impaired muscle function. The transcription factor FOXO and its target 4E-BP remove damaged proteins at least in part via the autophagy/lysosome system, while foxo mutants have dysfunctional proteostasis. Both FOXO and 4E-BP delay muscle functional decay and extend lifespan. Moreover, FOXO/4E-BP signaling in muscles decreases feeding behavior and the release of Insulin from producing cells, which in turn delays the age-related accumulation of protein aggregates in other tissues. These findings reveal an organism-wide regulation of proteostasis in response to muscle aging, and a key role of FOXO/4E-BP signaling in the coordination of organismal and tissue aging. PMID:21111239

  3. Tests of simulated Gaia BP/RP spectra with LDS (Low Dispersion Spectroscopy) photographic sky surveys

    NASA Astrophysics Data System (ADS)

    Hudec, René; Hudec, Lukáš

    2011-12-01

    The LDS (Low Dispersion Spectroscopy) performed in various extended sky surveys with optical telescopes using objective prism and photographic plates offers an interesting opportunity to test simulated low-dispersion spectra for the Gaia BP/RP photometers and to compare them with real data, especially for objects with strong emission lines. We present a review of astrophysics with LDS performed in the past, as well as an overview of existing extended sky surveys (with photographic plates) providing LDS data. Some of them provide almost complete coverage of the northern or southern hemisphere (e.g. the Northern and Southern Mt Wilson - Michigan Hα surveys or the German La Paz Bolivia Southern Spectral Sky Survey). We show examples of these data and discuss a comparison of existing LDS plate data with expected/simulated Gaia BP/RP data. We show examples of real data for objects with very strong and wide emission features confirming that such features will be detectable with Gaia BP/RP. We also discuss the importance of Gaia RP/BP low-dispersion spectroscopy for astrophysical studies.

  4. 75 FR 60097 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... oil spill and to develop options to guard against, and mitigate the impact of, any oil spills... mitigate the impact of, any oil spills associated with offshore drilling in the future. Tentative Agenda... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling AGENCY: Department...

  5. 75 FR 69652 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... oil spill and to develop options to guard against, and mitigate the impact of, any oil spills... mitigate the impact of, any oil spills associated with offshore drilling in the future. Tentative Agenda... National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling AGENCY: Department...

  6. 75 FR 29397 - National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... options for guarding against, and mitigating the impact of, oil spills associated with offshore drilling... established the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling (the... with their ongoing activities in response to the oil spill, shall provide the Commission...

  7. The C-terminal domain of the transcriptional corepressor CtBP is intrinsically unstructured.

    PubMed

    Nardini, Marco; Svergun, Dmitri; Konarev, Peter V; Spanò, Stefania; Fasano, Mauro; Bracco, Chiara; Pesce, Alessandra; Donadini, Alessandra; Cericola, Claudia; Secundo, Francesco; Luini, Alberto; Corda, Daniela; Bolognesi, Martino

    2006-05-01

    C-terminal binding proteins (CtBPs) are moonlighting proteins involved in nuclear transcriptional corepression and in Golgi membrane tubule fission. Structural information on CtBPs is available for their substrate-binding domain, responsible for transcriptional repressor recognition/binding, and for the nucleotide-binding domain, involved in NAD(H)-binding and dimerization. On the contrary, little is known about the structure of CtBP C-terminal region ( approximately 90 residues), hosting sites for post-translational modifications. In the present communication we apply a combined approach based on bioinformatics, nuclear magnetic resonance, circular dichroism spectroscopy, and small-angle X-ray scattering, and we show that the CtBP C-terminal region is intrinsically unstructured in the full-length CtBP and in constructs lacking the substrate- and/or the nucleotide-binding domains. The flexible nature of this protein region, and its structural transitions, may be instrumental for CtBP recognition and binding to diverse molecular partners. PMID:16597837

  8. The discovery and taxonomic implications of a novel 41bp chloroplast DNA deletion in wild potatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 241-bp chloroplast deletion in the intergenic region flanking the 3'end of the trnV-UAC gene has been shown to have major phylogenetic importance in determining the origin of the cultivated potato, as it characterizes most landrace populations from lowland Chile and putative wild species in Bolivi...

  9. BEARDSLEY AND PIPER (B&P) CORE BLOWING MACHINE. VIRGINIA BLAKELY MANUALLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BEARDSLEY AND PIPER (B&P) CORE BLOWING MACHINE. VIRGINIA BLAKELY MANUALLY FILLING SAND MAGAZINE THAT WILL ROTATE WITH THE CORE BOX, FILLING IT UNDER PRESSURE SIMILAR TO THE CORE MACHINE IN THE BACKGROUND. - Southern Ductile Casting Company, Core Making, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  10. Characterization of the Particulate Emissions from the BP Deepwell Horizon Spill Surface Oil Burns

    EPA Science Inventory

    A particle sample gathered from the plume of the purposely-burned surface oil during the BP Deepwater Horizon disaster in the Gulf of Mexico was analyzed for polycyclic aromatic hydrocarbons (PAHs), organic acids, organic carbon (OC), elemental carbon (EC), metals, and chloro-org...

  11. RanBP9 Overexpression Accelerates Loss of Dendritic Spines in a Mouse Model of Alzheimer's Disease

    PubMed Central

    Wang, Ruizhi; Palavicini, Juan Pablo; Wang, Hongjie; Maiti, Panchanan; Bianchi, Elisabetta; Xu, Shaohua; Lloyd, BN; Dawson-Scully, Ken; Kang, David E; Lakshmana, Madepalli K.

    2014-01-01

    We previously demonstrated that RanBP9 overexpression increased Aβ generation and amyloid plaque burden, subsequently leading to robust reductions in the levels of several synaptic proteins as well as deficits in the learning and memory skills in a mouse model of Alzheimer's disease (AD). In the present study, we found striking reduction of spinophilin-immunoreactive puncta (52%, p<0.001) and spinophilin area (62.5%, p<0.001) in the primary cortical neurons derived from RanBP9 transgenic mice (RanBP9-Tg) compared to wild-type (WT) neurons. Similar results were confirmed in WT cortical neurons transfected with EGFP-RanBP9. At 6-months of age, the total spine density in the cortex of RanBP9 single transgenic, APΔE9 double transgenic and APΔE9/RanBP9 triple transgenic mice were similar to WT mice. However, in the hippocampus the spine density was significantly reduced (27%, p<0.05) in the triple transgenic mice compared to WT mice due to reduced number of thin spines (33%, p<0.05) and mushroom spines (22%, p<0.05). This suggests that RanBP9 overexpression in the APΔE9 mice accelerates loss of spines and that hippocampus is more vulnerable. At 12-months of age, cortex showed significant reductions in total spine density in the RanBP9 (22%, p<0.05), APΔE9 (19%, p<0.05) and APΔE9/RanBP9 (33%, p<0.01) mice compared to WT controls due to reductions in mushroom and thin spines. Similarly, in the hippocampus the total spine density was reduced in the RanBP9 (23%, p<0.05), APΔE9 (26%, p<0.05) and APΔE9/RanBP9 (39%, p<0.01) mice due to reductions in thin and mushroom spines. Most importantly, RanBP9 overexpression in the APΔE9 mice further exacerbated the reductions in spine density in both the cortex (14%, p<0.05) and the hippocampus (16%, p<0.05). Because dendritic spines are considered physical traces of memory, loss of spines due to RanBP9 provided the physical basis for the learning and memory deficits. Since RanBP9 protein levels are increased in AD brains, RanBP

  12. RanBP9 overexpression accelerates loss of dendritic spines in a mouse model of Alzheimer's disease.

    PubMed

    Wang, Ruizhi; Palavicini, Juan Pablo; Wang, Hongjie; Maiti, Panchanan; Bianchi, Elisabetta; Xu, Shaohua; Lloyd, B N; Dawson-Scully, Ken; Kang, David E; Lakshmana, Madepalli K

    2014-09-01

    We previously demonstrated that RanBP9 overexpression increased Aβ generation and amyloid plaque burden, subsequently leading to robust reductions in the levels of several synaptic proteins as well as deficits in the learning and memory skills in a mouse model of Alzheimer's disease (AD). In the present study, we found striking reduction of spinophilin-immunoreactive puncta (52%, p<0.001) and spinophilin area (62.5%, p<0.001) in the primary cortical neurons derived from RanBP9 transgenic mice (RanBP9-Tg) compared to wild-type (WT) neurons. Similar results were confirmed in WT cortical neurons transfected with EGFP-RanBP9. At 6-months of age, the total spine density in the cortex of RanBP9 single transgenic, APΔE9 double transgenic and APΔE9/RanBP9 triple transgenic mice was similar to WT mice. However, in the hippocampus the spine density was significantly reduced (27%, p<0.05) in the triple transgenic mice compared to WT mice due to reduced number of thin spines (33%, p<0.05) and mushroom spines (22%, p<0.05). This suggests that RanBP9 overexpression in the APΔE9 mice accelerates loss of spines and that the hippocampus is more vulnerable. At 12-months of age, the cortex showed significant reductions in total spine density in the RanBP9 (22%, p<0.05), APΔE9 (19%, p<0.05) and APΔE9/RanBP9 (33%, p<0.01) mice compared to WT controls due to reductions in mushroom and thin spines. Similarly, in the hippocampus the total spine density was reduced in the RanBP9 (23%, p<0.05), APΔE9 (26%, p<0.05) and APΔE9/RanBP9 (39%, p<0.01) mice due to reductions in thin and mushroom spines. Most importantly, RanBP9 overexpression in the APΔE9 mice further exacerbated the reductions in spine density in both the cortex (14%, p<0.05) and the hippocampus (16%, p<0.05). Because dendritic spines are considered physical traces of memory, loss of spines due to RanBP9 provided the physical basis for the learning and memory deficits. Since RanBP9 protein levels are increased in AD

  13. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    PubMed Central

    2012-01-01

    Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER), analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der) was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII) transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM) plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP), had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM plants expressing, for

  14. Drosophila Longevity Assurance Conferred by Reduced Insulin Receptor Substrate Chico Partially Requires d4eBP

    PubMed Central

    Bai, Hua; Post, Stephanie; Kang, Ping; Tatar, Marc

    2015-01-01

    Mutations of the insulin/IGF signaling (IIS) pathway extend Drosophila lifespan. Based on genetic epistasis analyses, this longevity assurance is attributed to downstream effects of the FOXO transcription factor. However, as reported FOXO accounts for only a portion of the observed longevity benefit, suggesting there are additional outputs of IIS to mediate aging. One candidate is target of rapamycin complex 1 (TORC1). Reduced TORC1 activity is reported to slow aging, whereas reduced IIS is reported to repress TORC1 activity. The eukaryotic translation initiation factor 4E binding protein (4E-BP) is repressed by TORC1, and activated 4E-BP is reported to increase Drosophila lifespan. Here we use genetic epistasis analyses to test whether longevity assurance mutants of chico, the Drosophila insulin receptor substrate homolog, require Drosophila d4eBP to slow aging. In chico heterozygotes, which are robustly long-lived, d4eBP is required but not sufficient to slow aging. Remarkably, d4eBP is not required or sufficient for chico homozygotes to extend longevity. Likewise, chico heterozygote females partially require d4eBP to preserve age-dependent locomotion, and both chico genotypes require d4eBP to improve stress-resistance. Reproduction and most measures of growth affected by either chico genotype are always independent of d4eBP. In females, chico heterozygotes paradoxically produce more rather than less phosphorylated 4E-BP (p4E-BP). Altered IRS function within the IIS pathway of Drosophila appears to have partial, conditional capacity to regulate aging through an unconventional interaction with 4E-BP. PMID:26252766

  15. Negative control of circadian clock regulator E4BP4 by casein kinase Iepsilon-mediated phosphorylation.

    PubMed

    Doi, Masao; Okano, Toshiyuki; Yujnovsky, Irene; Sassone-Corsi, Paolo; Fukada, Yoshitaka

    2004-06-01

    Light-dependent transcriptional regulation of clock genes is a crucial step in the entrainment of the circadian clock. E4bp4 is a light-inducible gene in the chick pineal gland, and it encodes a bZIP protein that represses transcription of cPer2, a chick pineal clock gene. Here, we demonstrate that prolonged light period-dependent accumulation of E4BP4 protein is temporally coordinated with a delay of the rising phase of cPer2 in the morning. E4BP4 was phosphorylated progressively and then disappeared in parallel with induced cPer2 expression. Characterization of E4BP4 revealed Ser182, a phosphoacceptor site located at the amino-terminal border of the Ser/Thr cluster, which forms the phosphorylation motifs for casein kinase 1epsilon (CK1epsilon). CK1epsilon physically associated with E4BP4 and phosphorylated it. CK1epsilon-catalyzed phosphorylation of E4BP4 resulted in proteasomal proteolysis-dependent decrease of E4BP4 levels, while E4BP4 nuclear accumulation was attenuated by CK1epsilon in a kinase activity-independent manner. CK1epsilon-mediated posttranslational regulation was accompanied by reduction of the transcriptional repression executed by E4BP4. These results not only demonstrate a phosphorylation-d