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Sample records for acre island formation

  1. Minimum age of the Neoproterozoic Seven Hundred Acre Island Formation and the tectonic setting of the Islesboro Formation, Islesboro block, Maine

    USGS Publications Warehouse

    Stewart, D.B.; Tucker, R.D.; Ayuso, R.A.; Lux, D.R.

    2001-01-01

    Two platformal stratigraphic sequences occur on Islesboro, Penobscot Bay, Maine. The older Seven Hundred Acre Island Formation is at least 200 m thick, its base is not exposed, and it makes up fault-bounded blocks of siliceous colour-banded dolomitic marble, muscovite-rich quartzite, coarse-grained splendent muscovite-garnet-staurolite-andalusite schist, and calcareous metapelite, with minor garnet amphibolite and amphibolite. It was initially metamorphosed to lower amphibolite facies and was later to lower greenschist facies. The lower amphibolite facies metamorphism is Neoproterozoic (670 to 650 Ma) as inferred from the 40Ar/39Ar high temperature release spectra of hornblende separates. A U-Pb zircon age of 646.7 ?? 2.7 Ma obtained for a pegmatite that intruded deformed rocks is taken to be the minimum age of the Formation. The platformal Islesboro Formation probably unconformably overlies the Seven Hundred Acre Island Formation. It is primarily turbiditic pelite with many beds of quartzite, impure dolomitic marble, some conglomerate, and a few feldsparrich volcaniclastic beds and is thought to be either Neoproterozoic or Cambrian. It was metamorphosed only to lower greenschist facies, possibly in the same event that retrograded the Seven Hundred Acre Island Formation. Geochemical interpretations of minor and trace element analyses of six amphibolite and four schist samples from the Seven Hundred Acre Island Formation show that the protoliths of the amphibolite samples were intermediate between tholeiitic and within-plate type basaltic flows or dikes that intruded attenuated continental crust, or were eroded from these basalts. Four amphibolite and three schist samples analyzed for Pb isotopes were found to be enriched in radiogenic Pb. The Pb isotopic compositions are similar to those in peri-Gondwanan basement rocks from Atlantic Canada. The peri-Gondwanan Islesboro block was placed against the peri-Gondwanan Middle and Late Cambrian Ellsworth terrane on the

  2. Island Formation: Constructing a Coral Island

    ERIC Educational Resources Information Center

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  3. Receptor-like kinase ACR4 restricts formative cell divisions in the Arabidopsis root.

    PubMed

    De Smet, Ive; Vassileva, Valya; De Rybel, Bert; Levesque, Mitchell P; Grunewald, Wim; Van Damme, Daniël; Van Noorden, Giel; Naudts, Mirande; Van Isterdael, Gert; De Clercq, Rebecca; Wang, Jean Y; Meuli, Nicholas; Vanneste, Steffen; Friml, Jirí; Hilson, Pierre; Jürgens, Gerd; Ingram, Gwyneth C; Inzé, Dirk; Benfey, Philip N; Beeckman, Tom

    2008-10-24

    During the development of multicellular organisms, organogenesis and pattern formation depend on formative divisions to specify and maintain pools of stem cells. In higher plants, these activities are essential to shape the final root architecture because the functioning of root apical meristems and the de novo formation of lateral roots entirely rely on it. We used transcript profiling on sorted pericycle cells undergoing lateral root initiation to identify the receptor-like kinase ACR4 of Arabidopsis as a key factor both in promoting formative cell divisions in the pericycle and in constraining the number of these divisions once organogenesis has been started. In the root tip meristem, ACR4 shows a similar action by controlling cell proliferation activity in the columella cell lineage. Thus, ACR4 function reveals a common mechanism of formative cell division control in the main root tip meristem and during lateral root initiation.

  4. Biofilm formation ability of Salmonella enterica serovar Typhimurium acrAB mutants.

    PubMed

    Schlisselberg, Dov B; Kler, Edna; Kisluk, Guy; Shachar, Dina; Yaron, Sima

    2015-10-01

    Recent studies offer contradictory findings about the role of multidrug efflux pumps in bacterial biofilm development. Thus, the aim of this study was to investigate the involvement of the AcrAB efflux pump in biofilm formation by investigating the ability of AcrB and AcrAB null mutants of Salmonella enterica serovar Typhimurium to produce biofilms. Three models were used to compare the ability of S. Typhimurium wild-type and its mutants to form biofilms: formation of biofilm on polystyrene surfaces; production of biofilm (mat model) on the air/liquid interface; and expression of curli and cellulose on Congo red-supplemented agar plates. All three investigated genotypes formed biofilms with similar characteristics. However, upon exposure to chloramphenicol, formation of biofilms on solid surfaces as well as the production of curli were either reduced or were delayed more significantly in both mutants, whilst there was no visible effect on pellicle formation. It can be concluded that when no selective pressure is applied, S. Typhimurium is able to produce biofilms even when the AcrAB efflux pumps are inactivated, implying that the use of efflux pump inhibitors to prevent biofilm formation is not a general solution and that combined treatments might be more efficient. Other factors that affect the ability to produce biofilms depending on efflux pump activity are yet to be identified.

  5. Magnetic-island formation

    SciTech Connect

    Boozer, A.H.

    1983-08-01

    The response of a finite conductivity plasma to resonant magnetic perturbations is studied. The equations, which are derived for the time development of magnetic islands, help one interpret the singular currents which occur under the assumption of perfect plasma conductivity. The relation to the Rutherford regime of resistive instabilities is given.

  6. PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root.

    PubMed

    Yue, Kun; Sandal, Priyanka; Williams, Elisabeth L; Murphy, Evan; Stes, Elisabeth; Nikonorova, Natalia; Ramakrishna, Priya; Czyzewicz, Nathan; Montero-Morales, Laura; Kumpf, Robert; Lin, Zhefeng; van de Cotte, Brigitte; Iqbal, Mudassar; Van Bel, Michiel; Van De Slijke, Eveline; Meyer, Matthew R; Gadeyne, Astrid; Zipfel, Cyril; De Jaeger, Geert; Van Montagu, Marc; Van Damme, Daniël; Gevaert, Kris; Rao, A Gururaj; Beeckman, Tom; De Smet, Ive

    2016-02-02

    In plants, the generation of new cell types and tissues depends on coordinated and oriented formative cell divisions. The plasma membrane-localized receptor kinase ARABIDOPSIS CRINKLY 4 (ACR4) is part of a mechanism controlling formative cell divisions in the Arabidopsis root. Despite its important role in plant development, very little is known about the molecular mechanism with which ACR4 is affiliated and its network of interactions. Here, we used various complementary proteomic approaches to identify ACR4-interacting protein candidates that are likely regulators of formative cell divisions and that could pave the way to unraveling the molecular basis behind ACR4-mediated signaling. We identified PROTEIN PHOSPHATASE 2A-3 (PP2A-3), a catalytic subunit of PP2A holoenzymes, as a previously unidentified regulator of formative cell divisions and as one of the first described substrates of ACR4. Our in vitro data argue for the existence of a tight posttranslational regulation in the associated biochemical network through reciprocal regulation between ACR4 and PP2A-3 at the phosphorylation level.

  7. Magnetic island formation in tokamaks

    SciTech Connect

    Yoshikawa, S.

    1989-04-01

    The size of a magnetic island created by a perturbing helical field in a tokamak is estimated. A helical equilibrium of a current- carrying plasma is found in a helical coordinate and the helically flowing current in the cylinder that borders the plasma is calculated. From that solution, it is concluded that the helical perturbation of /approximately/10/sup /minus/4/ of the total plasma current is sufficient to cause an island width of approximately 5% of the plasma radius. 6 refs.

  8. Peat Formation on Minjerribah (North Stradbroke Island), subtropical eastern Australia

    NASA Astrophysics Data System (ADS)

    Moss, Patrick; Tibby, John; Barr, Cameron; Weerensena, Chagi; Gontz, Allen; Petherick, Lynda

    2016-04-01

    Minjerribah (North Stradbroke Island) is the second largest sand island in the world and contains extensive peat dominated wetlands, comprising ~20% of the total area of the island. These wetland systems include large areas of estuarine swamps [mainly mangrove forest (~16% of the island's wetland area)], freshwater swamps [both herb (~58% of the island's wetland area) and tree dominated (~20% of the island's wetland area)] and numerous lake systems [both perched and window lakes (~2% of the island's wetland area)]. This presentation will examine peat formation processes at four wetland sites: a late Holocene prograding beach system (Flinders Beach); a 150,000 year lacustrine system (Welsby Lagoon 1), as well as a late Holocene lacustrine/palustrine system (Welsby Lagoon 2); and a late Quaternary lacustrine/palustrine system (Tortoise Lagoon), as well as discussing broader environmental characteristics of Minjerribah's nationally and internationally important wetland systems.

  9. Tree island pattern formation in the Florida Everglades

    USGS Publications Warehouse

    Carr, Joel; D'Odorico, P.; Engel, Victor C.; Redwine, Jed

    2016-01-01

    The Florida Everglades freshwater landscape exhibits a distribution of islands covered by woody vegetation and bordered by marshes and wet prairies. Known as “tree islands”, these ecogeomorphic features can be found in few other low gradient, nutrient limited freshwater wetlands. In the last few decades, however, a large percentage of tree islands have either shrank or disappeared in apparent response to altered water depths and other stressors associated with human impacts on the Everglades. Because the processes determining the formation and spatial organization of tree islands remain poorly understood, it is still unclear what controls the sensitivity of these landscapes to altered conditions. We hypothesize that positive feedbacks between woody plants and soil accretion are crucial to emergence and decline of tree islands. Likewise, positive feedbacks between phosphorus (P) accumulation and trees explain the P enrichment commonly observed in tree island soils. Here, we develop a spatially-explicit model of tree island formation and evolution, which accounts for these positive feedbacks (facilitation) as well as for long range competition and fire dynamics. It is found that tree island patterns form within a range of parameter values consistent with field data. Simulated impacts of reduced water levels, increased intensity of drought, and increased frequency of dry season/soil consuming fires on these feedback mechanisms result in the decline and disappearance of tree islands on the landscape.

  10. Thermodynamic model of coherent island formation on vicinal substrate

    SciTech Connect

    Zhang, Xu Sun, Xiao-Hong; Yu, Yanguang; Ren, Xiaomin

    2014-04-28

    A thermodynamic model has been proposed to address the formation of coherent island on the vicinal substrate. The morphological transition from square based island to elongated based one with various substrate misorientations is described. The initial stage of nucleation and growth process of islands in Stranski–Krastanow system is studied by taking into account the elastic deformations and the change of energy in the case of two-dimensional growth mode. The theoretical analysis shows the minimum nucleation barrier of island is on the decrease with increment of substrate misorientation, which means the nucleation of island on vicinal substrate is more favorable than that on flat substrate. By using the fitting data of experimental results done by Persichetti et al., [Phys. Rev. Lett. 104, 036104 (2010) and Phys. Rev. B 82, 121309(R) (2010)], we provide a meaningful explanation of the experimental observations.

  11. Increase of island density via formation of secondary ordered islands on pit-patterned Si (001) substrates

    SciTech Connect

    Zhong, Z.; Schmidt, O.G.; Bauer, G.

    2005-09-26

    Site-controlled groups of Ge islands are grown on pit-patterned Si (001) substrates. By varying the deposited amount of Ge, we find that the growth starts with the formation of a single island at the pit bottom and then proceeds to the formation of a highly symmetric Ge island group around the pit top. A bimodal size distribution of dome-shaped islands at the bottom and at the top corners of the pits is observed. A growth mechanism is proposed to qualitatively explain these phenomena. Our experiments help to promote a further understanding of Ge island growth on patterned substrates.

  12. Soil formation in Seymour Island, Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Souza, Katia Karoline Delpupo; Schaefer, Carlos Ernesto G. R.; Simas, Felipe Nogueira Bello; Spinola, Diogo Noses; de Paula, Mayara Daher

    2014-11-01

    The Antarctic Peninsula marks the climatic transition between Maritime and Continental Antarctica. Ice-free areas at the western side of the Peninsula (Maritime Antarctica) have been increasingly studied in the last 10 years whereas soils on the eastern coast have been relatively less studied. The objective of the present study is to analyze the properties of soils developed on Seymour Island, in the Weddell sea sector, eastern coast of the Antarctic Peninsula, in order to identify the main factors and processes involved in soil formation under semi-polar desert conditions in this part of Antarctica. Twenty-one pedons were described, sampled and analyzed for their physical, chemical and mineralogical attributes. Most of the soils were classified as Gelisols and Cryosols by the Soil Taxonomy and WRB/FAO, respectively. Three soil groups were found: immature alkaline soils on sandstones and siltstones, acid sulfate and ornithogenic soils. Soils have little cryoturbation and are all affected by salinization with natric and salic characters. Acid sulfate soils are the most weathered soils in Seymour Island. Due to the dry climate, phosphatization is still incipient with P-rich ornithogenic layers with little interaction with the mineral substrate. The Soil Taxonomy and WRB/FAO systems lack adequate classification criteria to classify all soils developed in transitional areas that are affected by a combination of salinization, sulfurization and phosphatization.

  13. Praise Acres Project

    ERIC Educational Resources Information Center

    Hayes, Carolyn

    2004-01-01

    In this article, the author presents the "Praise Acres Project," which was initiated from a letter written by a local resident. The resident wrote about an idea to develop a wetlands and outdoor lab facility on his property for students. Thus, a plan was conceived that would not only benefit the owner, but also enhance high school science…

  14. Biogenicity of an Early Quaternary iron formation, Milos Island, Greece.

    PubMed

    Chi Fru, E; Ivarsson, M; Kilias, S P; Frings, P J; Hemmingsson, C; Broman, C; Bengtson, S; Chatzitheodoridis, E

    2015-05-01

    A ~2.0-million-year-old shallow-submarine sedimentary deposit on Milos Island, Greece, harbours an unmetamorphosed fossiliferous iron formation (IF) comparable to Precambrian banded iron formations (BIFs). This Milos IF holds the potential to provide clues to the origin of Precambrian BIFs, relative to biotic and abiotic processes. Here, we combine field stratigraphic observations, stable isotopes of C, S and Si, rock petrography and microfossil evidence from a ~5-m-thick outcrop to track potential biogeochemical processes that may have contributed to the formation of the BIF-type rocks and the abrupt transition to an overlying conglomerate-hosted IF (CIF). Bulk δ(13) C isotopic compositions lower than -25‰ provide evidence for biological contribution by the Calvin and reductive acetyl-CoA carbon fixation cycles to the origin of both the BIF-type and CIF strata. Low S levels of ~0.04 wt.% combined with δ(34) S estimates of up to ~18‰ point to a non-sulphidic depository. Positive δ(30) Si records of up to +0.53‰ in the finely laminated BIF-type rocks indicate chemical deposition on the seafloor during weak periods of arc magmatism. Negative δ(30) Si data are consistent with geological observations suggesting a sudden change to intense arc volcanism potentially terminated the deposition of the BIF-type layer. The typical Precambrian rhythmic rocks of alternating Fe- and Si-rich bands are associated with abundant and spatially distinct microbial fossil assemblages. Together with previously proposed anoxygenic photoferrotrophic iron cycling and low sedimentary N and C potentially connected to diagenetic denitrification, the Milos IF is a biogenic submarine volcano-sedimentary IF showing depositional conditions analogous to Archaean Algoma-type BIFs.

  15. The ISLAndS Project. II. The Lifetime Star Formation Histories of Six Andomeda dSphS

    NASA Astrophysics Data System (ADS)

    Skillman, Evan D.; Monelli, Matteo; Weisz, Daniel R.; Hidalgo, Sebastian L.; Aparicio, Antonio; Bernard, Edouard J.; Boylan-Kolchin, Michael; Cassisi, Santi; Cole, Andrew A.; Dolphin, Andrew E.; Ferguson, Henry C.; Gallart, Carme; Irwin, Mike J.; Martin, Nicolas F.; Martínez-Vázquez, Clara E.; Mayer, Lucio; McConnachie, Alan W.; McQuinn, Kristen B. W.; Navarro, Julio F.; Stetson, Peter B.

    2017-03-01

    The Initial Star formation and Lifetimes of Andromeda Satellites (ISLAndS) project employs Hubble Space Telescope imaging to study a representative sample of six Andromeda dSph satellite companion galaxies. Our main goal is to determine whether the star formation histories (SFHs) of the Andromeda dSph satellites demonstrate significant statistical differences from those of the Milky Way (MW). Our deep observations yield a time resolution at the oldest ages of ∼1 Gyr, allowing meaningful comparisons to the MW satellites. The six dSphs present a variety of SFHs (e.g., a significant range in quenching times, {τ }q, from 9 to 6 Gyr ago) that are not strictly correlated with luminosity or present distance from M31. In agreement with observations of MW companions of similar mass, there is no evidence of complete quenching of star formation by the cosmic UV background responsible for reionization, but the possibility of a degree of quenching at reionization cannot be ruled out. We do not find significant differences between the SFHs of the members and non-members of the vast, thin plane of satellites. The SFHs of the ISLAndS M31 dSphs appear to be more uniform than those of the MW dSphs. Specifically, the primary difference between the SFHs of the ISLAndS dSphs and MW dSph companions of similar luminosities and host distances is the absence of late-quenching ({τ }q≤slant 5 {Gyr}) dSphs in the ISLAndS sample. Thus, models that can produce satellite populations with and without late-quenching satellites are of extreme interest. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13028, 13739.

  16. Molecular cloning and characterization of acrA and acrE genes of Escherichia coli.

    PubMed Central

    Ma, D; Cook, D N; Alberti, M; Pon, N G; Nikaido, H; Hearst, J E

    1993-01-01

    The DNA fragment containing the acrA locus of the Escherichia coli chromosome has been cloned by using a complementation test. The nucleotide sequence indicates the presence of two open reading frames (ORFs). Sequence analysis suggests that the first ORF encodes a 397-residue lipoprotein with a 24-amino-acid signal peptide at its N terminus. One inactive allele of acrA from strain N43 was shown to contain an IS2 element inserted into this ORF. Therefore, this ORF was designated acrA. The second downstream ORF is predicted to encode a transmembrane protein of 1,049 amino acids and is named acrE. Genes acrA and acrE are probably located on the same operon, and both of their products are likely to affect drug susceptibilities observed in wild-type cells. The cellular localizations of these polypeptides have been analyzed by making acrA::TnphoA and acrE::TnphoA fusion proteins. Interestingly, AcrA and AcrE share 65 and 77% amino acid identity with two other E. coli polypeptides, EnvC and EnvD, respectively. Drug susceptibilities in one acrA mutant (N43) and one envCD mutant (PM61) have been determined and compared. Finally, the possible functions of these proteins are discussed. Images PMID:8407802

  17. How Big Is an Acre?

    ERIC Educational Resources Information Center

    Augustin, Byron D.; Brandes, Donald

    1984-01-01

    Many students do not have the slightest idea of how much land is in an acre. A diagram of the official playing field for American football is used to illustrate the approximate size of an acre of land. (RM)

  18. Continental Island Formation and the Archaeology of Defaunation on Zanzibar, Eastern Africa.

    PubMed

    Prendergast, Mary E; Rouby, Hélène; Punnwong, Paramita; Marchant, Robert; Crowther, Alison; Kourampas, Nikos; Shipton, Ceri; Walsh, Martin; Lambeck, Kurt; Boivin, Nicole L

    2016-01-01

    With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal

  19. Continental Island Formation and the Archaeology of Defaunation on Zanzibar, Eastern Africa

    PubMed Central

    Prendergast, Mary E.; Rouby, Hélène; Punnwong, Paramita; Marchant, Robert; Crowther, Alison; Kourampas, Nikos; Shipton, Ceri; Walsh, Martin; Lambeck, Kurt; Boivin, Nicole L.

    2016-01-01

    With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal

  20. Secondary island formation in collisional and collisionless kinetic simulations of magnetic reconnection

    SciTech Connect

    Dayton, William S; Roytershteyn, Vadim; Gary, Peter; Yin, L; Albright, B J; Bowers, K J; Karimabadi, H

    2009-01-01

    The evolution of magnetic reconnection in large-scale systems often gives rise to extended current layers that are unstable to the formation of secondary magnetic islands. The role of these islands in the reconnection process and the conditions under which they form remains a subject of debate. In this work, we benchmark two different kinetic particle-in-cell codes to address the formation of secondary islands for several types of global boundary conditions. The influence on reconnection is examined for a range of conditions and collisionality limits. Although secondary islands are observed in all cases, their influence on reconnection may be different depending on the regime. In the collisional limit, the secondary islands playa key role in breaking away from the Sweet-Parker scaling and enabling faster reconnection. In the collisionless limit, their formation is one mechanism for controlling the length of the diffusion region. In both limits, the onset of secondary islands leads to a time dependent behavior in the reconnection rate. In all cases considered, the number of secondary islands increases for larger systems.

  1. Mesoarchean Banded Iron Formation sequences in Dixon Island-Cleaverville Formation, Pilbara Australia: Oxygenic signal from DXCL project

    NASA Astrophysics Data System (ADS)

    Kiyokawa, S.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Naraoka, H.; Onoue, T.; Horie, K.; Sakamoto, R.; Aihara, Y.; Miki, T.

    2013-12-01

    The 3.2-3.1 Ga Dixon island-Cleaverville formations are well-preserved Banded Iron Formation (BIF) within hydrothermal oceanic sequence at oceanic island arc setting (Kiyokawa et al., 2002, 2006, 2012). The stratigraphy of the Dixon Island (3195+15Ma) -Cleaverville (3108+13Ma) formations shows the well preserved environmental condition at the Mesoarchean ocean floor. The stratigraphy of these formations are formed about volcano-sedimentary sequences with hydrothermal chert, black shale and banded iron formation to the top. Based on the scientific drilling of DXCL project at 2007 and 2011, detail lithology between BIF sequence was clearly understood. Four drilling holes had been done at coastal sites; the Dixon Island Formation is DX site (100m) and the Cleaverville Formation is CL2 (40m), CL1 (60m) and CL3 (200m) sites and from stratigraphic bottom to top. Coarsening and thickening upward black shale-BIF sequences are well preserved of the stratigraphy form the core samples. The Dixon Island Formation consists komatiite-rhyolite sequences with many hydrothermal veins and very fine laminated cherty rocks above them. The Cleaverville Formation contains black shale, fragments-bearing pyroclastic beds, white chert, greenish shale and BIF. The CL3 core, which drilled through BIF, shows siderite-chert beds above black shale identified before magnetite lamination bed. U-Pb SHRIMP data of the tuff in lower Dixon Island Formation is 3195+15 Ma and the pyroclastic sequence below the Cleaverville BIF is 3108+13 Ma. Sedimentation rate of these sequence is 2-8 cm/ 1000year. The hole section of the organic carbon rich black shales below BIF are similar amount of organic content and 13C isotope (around -30per mill). There are very weak sulfur MIF signal (less 0.2%) in these black shale sequence. Our result show that thick organic rich sediments may be triggered to form iron rich siderite and magnetite iron beds. The stratigraphy in this sequence quite resemble to other Iron

  2. Formation of islands of substitutional Li defects on the MgO (001) surface

    NASA Astrophysics Data System (ADS)

    Levchenko, Sergey V.; Scheffler, Matthias

    2010-03-01

    We use density functional theory (DFT) calculations to evaluate electronic structure and formation energies of the substitutional Li defects in the (001) surface, subsurface, and bulk MgO. We analyze the sensitivity of the results to the approximations in the exchange-correlation functional by comparing semi-local (GGA PBE) and non-local (PBE0 and B3LYP) approximations. Calculated formation energies indicate that the Li defects prefer to form islands with molar concentration 50% at the top layer, but not in the deeper layers. The formation energy of an isolated substitutional Li defect increases with the depth of the layer in which the defect is formed. We perform an ab initio atomistic thermodynamics [1] analysis to determine the average island size under realistic conditions. The analysis shows that, despite the loss in the configurational entropy due to the island formation, the islands containing 10-20 Li defects are present on the surface at relevant temperatures (900- 1000 K). Within the islands, the oxygen vacancy formation energy is greatly decreased due to an electron transfer from the O vacancy state to the lower energy states near the top of the valence band, associated with the Li defects.---[1] K. Reuter and M. Scheffler, Phys. Rev. B 65, 035406 (2001); C. M. Weinert and M. Scheffler, Mat. Sci. Forum 10-12, 25 (1986); M. Scheffler and J. Dabrowski, Phil. Mag. A 58, 107 (1988)

  3. Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation

    SciTech Connect

    Lee, Gloria; Lo, Annie; Short, Sarah A.; Mankelow, Tosti J.; Spring, Frances; Parsons, Stephen F.; Mohandas, Narla; Anstee, David J.; Chasis, Joel Anne

    2006-02-15

    Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule-4 (ICAM-4), animmunoglobulin superfamily member, participates in island formation. Earlier, we identified alpha V integrins as ICAM-4 counter receptors. Since macrophages express alpha V, ICAM-4 potentially mediates island attachments. To test this, we generated ICAM-4 knockout mice and developed quantitative, live cell techniques for harvesting intact islands and for reforming islands in vitro. We observed a 47 percent decrease in islands reconstituted from ICAM-4 null marrow compared to wild type. We also found a striking decrease in islands formed in vivo in knockout mice. Further, peptides that block ICAM-4 alpha V adhesion produced a 53-57 percent decrease in reconstituted islands, strongly suggesting that ICAM-4 binding to macrophage alpha V functions in island integrity. Importantly, we documented that alpha V integrin is expressed in macrophages isolated from erythro blastic islands. Collectively, these data provide convincing evidence that ICAM-4 is critical in erythroblastic island formation via ICAM-4/alpha V adhesion and also demonstrate that the novel experimental strategies we developed will be valuable in exploring molecular mechanisms of erythroblastic island formation and their functional role in regulating erythropoiesis.

  4. ACR Appropriateness Criteria Myelopathy.

    PubMed

    Roth, Christopher J; Angevine, Peter D; Aulino, Joseph M; Berger, Kevin L; Choudhri, Asim F; Fries, Ian Blair; Holly, Langston T; Kendi, Ayse Tuba Karaqulle; Kessler, Marcus M; Kirsch, Claudia F; Luttrull, Michael D; Mechtler, Laszlo L; O'Toole, John E; Sharma, Aseem; Shetty, Vilaas S; West, O Clark; Cornelius, Rebecca S; Bykowski, Julie

    2016-01-01

    Patients presenting with myelopathic symptoms may have a number of causative intradural and extradural etiologies, including disc degenerative diseases, spinal masses, infectious or inflammatory processes, vascular compromise, and vertebral fracture. Patients may present acutely or insidiously and may progress toward long-term paralysis if not treated promptly and effectively. Noncontrast CT is the most appropriate first examination in acute trauma cases to diagnose vertebral fracture as the cause of acute myelopathy. In most nontraumatic cases, MRI is the modality of choice to evaluate the location, severity, and causative etiology of spinal cord myelopathy, and predicts which patients may benefit from surgery. Myelopathy from spinal stenosis and spinal osteoarthritis is best confirmed without MRI intravenous contrast. Many other myelopathic conditions are more easily visualized after contrast administration. Imaging performed should be limited to the appropriate spinal levels, based on history, physical examination, and clinical judgment. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals, and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  5. ACR appropriateness criteria jaundice.

    PubMed

    Lalani, Tasneem; Couto, Corey A; Rosen, Max P; Baker, Mark E; Blake, Michael A; Cash, Brooks D; Fidler, Jeff L; Greene, Frederick L; Hindman, Nicole M; Katz, Douglas S; Kaur, Harmeet; Miller, Frank H; Qayyum, Aliya; Small, William C; Sudakoff, Gary S; Yaghmai, Vahid; Yarmish, Gail M; Yee, Judy

    2013-06-01

    A fundamental consideration in the workup of a jaundiced patient is the pretest probability of mechanical obstruction. Ultrasound is the first-line modality to exclude biliary tract obstruction. When mechanical obstruction is present, additional imaging with CT or MRI can clarify etiology, define level of obstruction, stage disease, and guide intervention. When mechanical obstruction is absent, additional imaging can evaluate liver parenchyma for fat and iron deposition and help direct biopsy in cases where underlying parenchymal disease or mass is found. Imaging techniques are reviewed for the following clinical scenarios: (1) the patient with painful jaundice, (2) the patient with painless jaundice, and (3) the patient with a nonmechanical cause for jaundice. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  6. 78 FR 2694 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Fukushima; Cancellation of the January 18, 2013, ACRS Subcommittee Meeting The ACRS Subcommittee meeting on...

  7. Characteristics of magnetic island formation due to resistive interchange instability in helical plasma

    SciTech Connect

    Ueda, R.; Matsumoto, Y.; Itagaki, M.; Oikawa, S.; Watanabe, K. Y.; Sato, M.

    2014-05-15

    Focusing attention on the magnetic island formation, we investigate the characteristics of the resistive interchange magnetohydrodynamics instabilities, which would limit a high beta operational regime in helical type fusion reactors. An introduction of a new index, i.e., the ratio of the magnetic fluctuation level to the radial displacement, enables us to make a systematic analysis on the magnetic island formation in the large helical device-like plasmas during the linear growth phase; (i) the interchange instability with the second largest growth rate makes the magnetic island larger than that with the largest growth rate when the amplitude of the radial displacement in both cases is almost the same as each other; (ii) applied to a typical tearing instability, the index is smaller than that for the interchange instability with the second largest growth rate.

  8. The upper Bow Island (Blackleaf) Formation of southwestern Alberta: Geological aspects and exploration approaches

    SciTech Connect

    Putnam, P.E.; Christensen, S.L. )

    1991-06-01

    The upper parts of the Bow Island Formation (Albian) of southwestern Alberta are significant gas reservoirs. The main westernmost reservoir zone is part of a complex package of interbedded lenticular sandstones, mudstones, and localized chert pebble conglomerates. The depositional setting for these sediments comprised a wave-dominated shoreline with conglomerates found proximal to drowned river mouths. The coarse nature of the upper Bow Island is related to tectonic movements associated with Crowsnest (Vaughn) volcanism. Conglomerates form the most impressive Bow Island reservoirs because of their thickness (up to 25 m) and petrophysical properties (17% porosity, 24 d permeability). Diagenesis dominantly comprises compaction features within grain-supported conglomerates. Increasing quartz content is related to decreasing grain size and is associated with porosity occlusion by quartz overgrowths. Bow Island reservoirs in southwestern Alberta are cool (under 50C) and significantly underpressured (0.2 psi). The high permeabilities and low pressures at depths of 1,000 to 1,500 m suggest the potential for formation damage is high, and many wells in the region were targeted for deeper, high-pressure zones. In spite of the low pressures, however, many Bow Island wells are capable of excellent gas deliveries with individual well recoveries of up to 10 bcf. All significant Bow Island porosity in the deepest, undisturbed parts of southwestern Alberta is gas saturated with updip aquifers flanking the gas. Seismic definition of the thickest Bow Island targets is feasible but has been hampered, in part, by difficult surface conditions and a prior emphasis on deeper targets.

  9. Land use planning and surface heat island formation: A parcel-based radiation flux approach

    NASA Astrophysics Data System (ADS)

    Stone, Brian; Norman, John M.

    This article presents a study of residential parcel design and surface heat island formation in a major metropolitan region of the southeastern United States. Through the integration of high-resolution multispectral data (10 m) with property tax records for over 100,000 single-family residential parcels in the Atlanta, Georgia, metropolitan region, the influence of the size and material composition of residential land use on an indicator of surface heat island formation is reported. In contrast to previous work on the urban heat island, this study derives a parcel-based indicator of surface warming to permit the impact of land use planning regulations governing the density and design of development on the excess surface flux of heat energy to be measured. The results of this study suggest that the contribution of individual land parcels to regional surface heat island formation could be reduced by approximately 40% through the adoption of specific land use planning policies, such as zoning and subdivision regulations, and with no modifications to the size or albedo of the residential structure.

  10. Kinetic Monte Carlo Simulation of Epitaxial Thin Film Growth: Formation of Submonolayer Islands and Multilayer Mounds

    SciTech Connect

    Evans, J. W.; Thiel, P. A.; Li, Maozhi

    2007-06-14

    We consider homoepitaxy (or low-misfit heteroepitaxy) via vapor deposition or MBE under UHV conditions. Thin film growth is initiated by nucleation and growth of 2D islands in the submonolayer regime. For atoms subsequently deposited on top of islands, a step edge barrier often inhibits downward transport and produces kinetic roughening during multilayer growth. Such unstable growth is characterized by the formation of 3D mounds (multilayer stacks of 2D islands). Kinetic Monte Carlo (KMC) simulation of suitable atomistic lattice-gas models can address fundamental or general issues related to both submonolayer and multilayer film evolution, and can also provide a predictive tool for morphological evolution in specific systems. Examples of the successes of KMC modeling are provided for metal homoepitaxial film growth, specifically for contrasting behavior in the classic Ag/Ag(100) and Ag/Ag(111) systems.

  11. Utilization Management and ACR Select.

    PubMed

    Cooke, Robert

    2015-01-01

    The ACR, published as ACR Select, provides an industry standard for imaging and through its experience with Appropriateness Criteria, is positioned to respond quickly to changing market demands. It has added hundreds of clinically relevant indications to ensure that even common scenarios have coverage. ACR Select is inclusive of numerous other credible content sources and actively receives vetted criteria from other medical specialty societies. ACR Select is well established in the market and available for integration into multiple physician access points. It also has support for the provisions and requirements of PL113-93. Healthcare providers have adopted ACR Select within their physician access points to deliver higher quality imaging services and understand the impact that imaging has on the overall care cycle. This better positions these providers to participate in risk-based contracts based on the value that appropriate imaging delivers. With the passage of PAMA, Congress has set a powerful precedent that has created the opportunity for every healthcare payer to transform the way imaging utilization is managed. Physicians will be required to consult Appropriateness Criteria delivered through CDS when placing orders for HTDI exams for Medicaid patients, and this can easily extend across the entire payer mix. PAMA has passed into public law (PLI113-93) and represents an opportunity for healthcare providers to develop risk based payment models across all imaging services, regardless of the payer of the claim or care setting.

  12. 77 FR 47680 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittees on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittees on Reliability and PRA and Fukushima; Revision to Notice of Meetings The (ACRS) Subcommittee on Fukushima...

  13. 77 FR 24745 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Thermal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Thermal Hydraulic Phenomena; Notice of Meeting The ACRS Subcommittee on Thermal Hydraulic Phenomena will hold...

  14. 76 FR 18585 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR); Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water...

  15. 78 FR 66968 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor...

  16. 76 FR 11524 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactors (ABWR); Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water...

  17. 78 FR 79019 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor...

  18. 77 FR 74698 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor...

  19. 78 FR 56756 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor...

  20. 76 FR 24540 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... From the Federal Register Online via the Government Publishing Office Nuclear Regulatory Commission Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor...

  1. 75 FR 55365 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Joint Subcommittee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-10

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Joint Subcommittee The ACRS Subcommittees on Thermal Hydraulics Phenomena; Advanced Boiling Water Reactor (ABWR); and Materials,...

  2. 76 FR 55717 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Reliability and Probabilistic Risk Assessment The ACRS Subcommittee on Reliability and PRA will hold a...

  3. 78 FR 34677 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the Acrs Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the Acrs Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels... pellet-cladding interaction during anticipated operational occurrences for Pressurized Water...

  4. 77 FR 76089 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR... Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  5. 78 FR 3474 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels... Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  6. 78 FR 29159 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-17

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels.... Cayetano Santos, Chief, Technical Support Branch, Advisory Committee on Reactor Safeguards. BILLING...

  7. 78 FR 79020 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  8. 75 FR 16874 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  9. 76 FR 61119 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  10. 75 FR 58447 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials The ACRS Subcommittee on Radiation Protection and Nuclear Materials...

  11. 78 FR 66967 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommitte on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommitte on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  12. 76 FR 27101 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  13. 76 FR 55717 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  14. 76 FR 55716 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of The ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of The ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  15. 77 FR 56240 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  16. 78 FR 17944 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  17. 76 FR 36160 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  18. 77 FR 68161 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  19. 76 FR 34779 - Advisory Committee On Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  20. 77 FR 38099 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  1. 75 FR 4881 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and...

  2. Campanian-Maastrichtian radiolarians from the Malokuril'skaya Formation, the Shikotan Island

    NASA Astrophysics Data System (ADS)

    Palechek, T. N.; Terekhov, E. P.; Mozherovskii, A. V.

    2008-12-01

    The results of radiolarian analysis confirm the Campanian-Maastrichtian age of the Malokuril’skaya Formation in the Shikotan Island. The Campanian-Maastrichtian age of the formation is implied simultaneously by radiolarians and inoceramids. The studied Campanian and Campanian-Maastrichtian radiolarian assemblages include abundant specimens representing genus Prunobrachium, characteristic of which was bipolar distribution in cold-water to temperate basins. The new occurrence site of prunobrachids is established at the latitude of 43°N, the Far East of Russia.

  3. Striated boulder pavements within glaciomarine diamicts of the Yakataga Formation, Middleton Island, Alaska

    SciTech Connect

    Eyles, C.H.

    1985-01-01

    The presence of striated boulder pavements in glacial sequences is often cited as evidence of transport and deposition by grounded glacier ice. However, recent reports show that striated pavements also form in non-glacial environments by the abrasion of boulder lag surfaces by floating glacier and seasonal ice. Several striated boulder pavements are identified within Early Pleistocene upper Yakataga Formation sediments exposed on Middleton Island close to the southern edge of the Gulf of Alaska continental shelf. The sequence is dominated by thick stratiform units of massive and stratified diamict formed by the settling of fine-grained sands and muds from suspension together with ice-rafted debris. Boulder pavements outcrop as extensive planar horizons within the diamicts, can be traced for several kilometers along strike and consist of single lines of clasts with faceted upper surfaces showing consistently oriented striation directions. Clasts are not preferentially aligned, however, and do not have the characteristic bullet shape of boulders transported at a glacier base and deposited by lodgement processes. Striated boulder pavements on Middleton Island appear to have formed as boulder lag surfaces generated by wave and tidal current reworking of diamict on relatively shallow banks. Lags were then overridden and abraded by a grounding ice shelf. The glacially-abraded boulder pavements on Middleton Island record the repeated expansion of a continuous ice shelf to the edge of the Gulf of Alaska continental shelf during the Early Pleistocene.

  4. Detailed forest formation mapping in the land cover map series for the Caribbean islands

    NASA Astrophysics Data System (ADS)

    Helmer, E. H.; Schill, S.; Pedreros, D. H.; Tieszen, L. L.; Kennaway, T.; Cushing, M.; Ruzycki, T.

    2006-12-01

    Forest formation and land cover maps for several Caribbean islands were developed from Landsat ETM+ imagery as part of a multi-organizational project. The spatially explicit data on forest formation types will permit more refined estimates of some forest attributes. The woody vegetation classification scheme relates closely to that of Areces-Malea et al. (1), who classify Caribbean vegetation according to standards of the US Federal Geographic Data Committee (FGDC, 1997), with modifications similar to those in Helmer et al. (2). For several of the islands, we developed image mosaics that filled cloudy parts of scenes with data from other scene dates after using regression tree normalization (3). The regression tree procedure permitted us to develop mosaics for wet and drought seasons for a few of the islands. The resulting multiseason imagery facilitated separation between classes such as seasonal evergreen forest, semi-deciduous forest (including semi-evergreen forest), and drought deciduous forest or woodland formations. We used decision tree classification methods to classify the Landsat image mosaics to detailed forest formations and land cover for Puerto Rico (4), St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines and Grenada. The decision trees classified a stack of raster layers for each mapping area that included the Landsat image bands and various ancillary raster data layers. For Puerto Rico, for example, the ancillary data included climate parameters (5). For some islands, the ancillary data included topographic derivatives such as aspect, slope and slope position, SRTM (6) or other topographic data. Mapping forest formations with decision tree classifiers, ancillary geospatial data, and cloud-free image mosaics, accurately distinguished spectrally similar forest formations, without the aid of ecological zone maps, on the islands where the approach was used. The approach resulted in maps of forest formations with comparable or better detail

  5. Pumice in the interglacial Whidbey Formation at Blowers Bluff, central Whidbey Island, WA, USA

    USGS Publications Warehouse

    Dethier, D.P.; Dragovich, J.D.; Sarna-Wojcicki, A. M.; Fleck, R.J.

    2008-01-01

    A new 40Ar/39Ar age of 128??9 ka and chemical analyses of pumice layers from interglacial alluvium at Blowers Bluff, Whidbey Island, WA, show that the deposits are part of the Whidbey Formation, a widespread, mainly subsurface unit. Glass chemistry of the dated dacitic pumice does not match any analyzed northern Cascade source, but upper Pleistocene dacites from Glacier Peak and early Pleistocene silicic rocks from the Kulshan caldera are chemically similar. The chemistry of pumiceous dacite in younger units, including the latest Pleistocene Partridge Gravel, is similar to that of the dated material. The deep troughs of the modern northern Puget lowland must have been filled during deposition of the Whidbey Formation, allowing volcanic-rich sediment to reach what is now Whidbey Island. Topographic analysis of LIDAR images demonstrates that extensive erosion occurred during latest Pleistocene ice retreat. The Partridge Gravel likely records subglacial fluvial erosion along an ice tunnel and ice-marginal deposition into adjacent marine waters. Pumice in the Partridge Gravel probably was reworked from stratigraphically and topographically lower deposits, including those at Blowers Bluff. ?? 2007 Elsevier Ltd and INQUA.

  6. Revisiting the Paleomagnetism of the Ghost Rocks Formation of the Kodiak Islands, Alaska

    NASA Astrophysics Data System (ADS)

    Gallen, S. F.; Housen, B. A.; Sarah, R. M.; O'Connell, K.

    2007-12-01

    The Paleocene Ghost Rocks Formation is the second youngest unit in the accretionary complex that comprise the Kodiak Islands, AK, part of the Chugach terrane, and consist of a sequence of turbidites interbedded with pillow lavas. Most workers agree that the anomalous near trench magmatism is a result of the passage of a trench- ridge-trench (TRT) along the margin of North America. However, it remains controversial as to the location where this interaction took place relative to the ancient North American margin. Plumley et al. (1983) conducted a paleomagnetic study on the pillow lavas of the Ghost Rocks Formation and concluded that they had formed at a latitude of 40° N. Discordant locality mean directions at the two localities of the study, Alitak and Kiliuda Bays and a complex two-stage structural correction used at Alitak Bay have cast doubt on the strength of this conclusion. This collaborative structural and paleomagnetic study seeks to resolve the location where the Ghost Rocks Formation formed using more detailed sampling and structural analysis. A total of 176 sites were sampled in 2006 and 2007, from four localities in the Kodiak Islands. This abstract will focus on samples collected from the Jap Bay locality, where sedimentary rocks were sampled. Preliminary results of sites taken at Jap Bay have two components of magnetization. The second-removed component has dual polarity and an improvement in clustering is observed upon tilt correction. These results are consistent with preliminary result of samples collected at two other sites of this study, Alitak and Kiliuda bays, suggesting the magnetic character recorded in the Ghost Rocks Formation is primary in origin. The inclinations are shallow relative to those expected for North America and at this time support models that place the Chugach terrane >1000km south of their present location.

  7. Structural Complexities Influencing Biostratigraphic Interpretations of the Permian Nansen Formation type-section, Ellesmere Island, Canada

    NASA Astrophysics Data System (ADS)

    Hill, M.; Guest, B.

    2011-12-01

    The Carboniferous to Permian aged Nansen Formation is a cyclic carbonate shelf deposit and potential hydrocarbon reservoir. This formation is the thickest, most widespread carbonate sequence in the Sverdrup Basin. Deformed during the Eurekan Orogeny, the Nansen Fm. is topographically prominent and responsible for the rugged topography on Axel Heiburg and Ellesmere Island. The type-section for the Nansen Fm. is located on the north side of Hare Fiord, along Girty Creek. At this location there is an estimated stratigraphic thickness of 2 km. Due to easier access most of the stratigraphic work has been completed on nearby glacially exposed sections that traverse parallel to Girty Creek along glacial margins. Extensive biostratigraphy was completed on a glacier section to the west, however, in a glacier section to the east of Girty Creek, structural complexities appear to be repeating sections of the formation. Here, the Nansen formation is bounded by two regional reverse faults. This has produced duplex structures, with clearly exposed stacked horses, footwall synclines, and truncations. By projecting the structures observed along the eastern glacier section to the western glacier section that was used for biostratigraphic studies, it is clear that these structures would affect biostratigraphic interpretations. It was previously noted by biostratigraphers that thrust faults appear to be repeating sections of the Nansen formation. However by correlating all observed faults with the biostratigraphy, we can determine the extent to which the faulting has affected the interpretations, and whether all faults or stratigraphic repetitions are accounted for.

  8. Refining the model of barrier island formation along a paraglacial coast in the Gulf of Maine

    USGS Publications Warehouse

    Hein, Christopher J.; FitzGerald, Duncan M.; Carruthers, Emily A.; Stone, Byron D.; Barnhardt, Walter A.; Gontz, Allen M.

    2012-01-01

    Details of the internal architecture and local geochronology of Plum Island, the longest barrier in the Gulf of Maine, have refined our understanding of barrier island formation in paraglacial settings. Ground-penetrating radar and shallow-seismic profiles coupled with sediment cores and radiocarbon dates provide an 8000-year evolutionary history of this barrier system in response to changes in sediment sources and supply rates as well as variability in the rate of sea-level change. The barrier sequence overlies tills of Wisconsinan and Illinoian glaciations as well as late Pleistocene glaciomarine clay deposited during the post-glacial sea-level highstand at approximately 17 ka. Holocene sediment began accumulating at the site of Plum Island at 7–8 ka, in the form of coarse fluvial channel-lag deposits related to the 50-m wide erosional channel of the Parker River that carved into underlying glaciomarine deposits during a lower stand of sea level. Plum Island had first developed in its modern location by ca. 3.6 ka through onshore migration and vertical accretion of reworked regressive and lowstand deposits. The prevalence of southerly, seaward-dipping layers indicates that greater than 60% of the barrier lithosome developed in its modern location through southerly spit progradation, consistent with a dominantly longshore transport system driven by northeast storms. Thinner sequences of northerly, landward-dipping clinoforms represent the northern recurve of the prograding spit. A 5–6-m-thick inlet-fill sequence was identified overlying the lower stand fluvial deposit; its stratigraphy captures events of channel migration, ebb-delta breaching, onshore bar migration, channel shoaling and inlet infilling associated with the migration and eventual closure of the inlet. This inlet had a maximum cross-sectional area of 2800 m2 and was active around 3.5–3.6 ka. Discovery of this inlet suggests that the tidal prism was once larger than at present. Bay infilling

  9. Canary Islands

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This easterly looking view shows the seven major volcanic islands of the Canary Island chain (28.0N, 16.5W) and offers a unique view of the islands that have become a frequent vacation spot for Europeans. The northwest coastline of Africa, (Morocco and Western Sahara), is visible in the background. Frequently, these islands create an impact on local weather (cloud formations) and ocean currents (island wakes) as seen in this photo.

  10. Cryosols Formation and classification in the semiarid Antarctica: the Weddel Sea sector of northern Seymour Island

    NASA Astrophysics Data System (ADS)

    Gjorup, Davi; Schaefer, Carlos; Francelino, Marcio

    2015-04-01

    The Seymour Island is located in the northern sector of the Weddell Sea zone, at the Antarctic Peninsular area, representing a transitional zone between Maritime and Continental Antarctica, with a subpolar, semiarid climate. The Seymour Island is predominantly composed by marine sedimentary rocks of Cretaceus to Eocene age. The aims of this work were to study the chemical, physical, mineralogical and morphological attributes of a selected, representative toposequence of soils at the northern sector of Seymour Island. Soil formation processes and taxonomical implications were discussed. Nine soil profiles were described, collected and analysed, following a toposequence according to different parent materials and landforms. Samples were subjected to textural analysis, routine chemical analysis, chemical extractions by ammonium oxalate and CBD, as well as X ray diffraction. Permafrost is continuous and widespread, generally at depths of less than 100 cm, so the Gelisols order (Soil Taxonomy), or Cryosols (WRB), are the dominant soils. Cryoturbation and organic matter accumulation were not observed. Soils were separated into two groups: acid-sulphate soils and alkaline soils, unaffected by sulphates. The first are the best developed in the study area, meaning a significant physico-chemical and mineralogical alteration. Low pH and high Al saturation and potential acidity are typical. This accounts for primary mineral dissolution, and its absence in the clay fraction. Secondary minerals are those related to sulphide oxidation: soluble and insoluble sulphates, low crystalline Fe-hydroxides and little crystalline Fe phases. The peculiar yellowish colour of these soils are attributed to the presence of Fe-oxides and Jarosite. The presence of 2:1 clays (smectite and illite) in the Clay fraction despite the acidity is due to low leaching. The alkaline soils, non affected by sulphates do not showed any marked weathering or transformation, with high pH, low potential acidity

  11. 77 FR 45700 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ...); Meeting of the ACRS Subcommittee On Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will... addressing the Fukushima Near Term Task Force (NTTF) Recommendation 1: Enhanced Regulatory Framework....

  12. Stratigraphic setting of transgressive barrier-island reservoirs with an example from the Triassic Halfway Formation, Wembley field, Alberta, Canada

    SciTech Connect

    Willis, A.J.; Moslow, T.F. )

    1994-05-01

    Established models for landward barrier-island migration focus primarily on the preservation pattern of transgressive facies in the shoreface which are typically thin and buried beneath finer grained marine lower shoreface-to-offshore sediments. In contrast, transgressive barrier-island sandstones in the Triassic Halfway Formation of Wembley field in Alberta are preserved interbedded with, and overlain by, backbarrier and nonmarine sediments. These transgressive barrier sandstones formed from coalescing washover fans during shoreface retreat and were subsequently [open quotes]abandoned[close quotes] as the shoreline stabilized and resumed progradation. The abandoned transgressive barrier sandstones were subsequently blanketed by backbarrier and nonmarine sediments as the coastline continued to prograde. Abandoned transgressive barrier island sandstones in the Halfway Formation are 2-6 m thick, up to 2 km wide, and form paleocoastline-parallel trends tens of kilometers in length. The trends define the paleolandward limit of transgressive events. The updip pinch-out of these sandstones in backbarrier mudstones forms a stratigraphic trap for hydrocarbons in Wembley field. Top seal is provided by nonmarine mudstones and evaporites which buried and abandoned transgressive barrier island. The sandstone has porosities and permeabilities averaging 11% and 63 md, respectively. By using well logs and cores to correlate individual parasequences in the Halfway Formation to their updip termination, it is possible to define the extent of associated marine flooding events and therefore identify hydrocarbon exploration targets for abandoned transgressive barrier-island sandstones. 58 refs., 13 figs., 2 tabs.

  13. Paleomagnetism of Harutagawa formation in the Hohi Volcanic Zone in northeastern part of Kyushu Island, Japan

    NASA Astrophysics Data System (ADS)

    Kudou, T.; Shibuya, H.

    2008-12-01

    The Beppu-Shimabara graben in the Hohi Volcanic Zone (HVZ) in northeastern part of Kyushu Island, Japan is thought to be a volcano-tectonic depression. Volcanic stratigraphy and age studies of the area have unraveled the late Pliocene structural formation history of HVZ (e.g. Kamata, 1994, Kido, 2007). The age and sedimentation rate of lacustrine deposits in HVZ is one of the keys for interpreting the temporal relation between the formation of Beppu-Shimabara graben and the huge pyroclastic flows appeared in the area. We study the magnetostratigraphy of the Harutagawa formation, which is one of those lacustrine deposits. The formation is dominated by conglomerates and mad stones to siltstones, in the lower and upper parts, respectively, but bares many tuff layers all over the formation. Fission track ages of two tuff layers, one is from lower part and the other is from upper part of Harutagawa formation, are determined as 3.86 ± 0.77Ma and 3.6 ± 0.2Ma, respectively (Kido, 2007). Samples for paleomagnetic analyses have been collected at 28 sites in several continuous outcrop of the Harutagawa formation. The sites are set to be spaced equally in the stratigraphy. Samples were collected by a portable electric motor drill. A few pilot specimens from each site are subjected to progressive thermal and alternating field (AF) demagnetization. However, AF demagnetization is not effective. All remaining specimens are, therefore, submitted to the progressive thermal demagnetization. The samples have mean magnetic intensity of 1.7 × 10- 4A/m and 7.7 × 10-5A/m before and after demagnetization, respectively. Samples from 6 sites have no stable component or are thought to be completely remagnetized by the present magnetic field. As the result, 22 sites are determined their polarities; 8 were reversed and 14 were normal. The normal polarity sites were correlative to Sidufjall, Nunivak and Cochiti subchrons in the Gilbert reversed polarity chron. This correlation indicates that

  14. Formation of Garnet Granulite in the Lower Crust of a paleo-Island Arc

    NASA Astrophysics Data System (ADS)

    Garrido, Carlos J.; Padrón-Navarta, José Alberto; López Sánchez-Vizcaíno, Vicente; Bodinier, Jean-Louis; Bosch, Delphine; Marchesi, Claudio; Hidas, Károly

    2016-04-01

    The Jijal complex (Kohistan paleo-island arc complex, NW Pakistan) is a unique occurrence of high-pressure (HP), mafic, opx-free, garnet granulite formed in the lower crust of an island arc. The upper part of the Jijal Granulitic Gabbro Unit (GGU) records the arrested transformation of hornblende gabbronorite to garnet granulite, involving the coeval breakdown of amphibole and orthopyroxene, and the formation of garnet and quartz. Close to the transformation front (2-3 cm), clinopyroxene from the granulite displays a strong Ca-tschermak zoning with lower Al-contents at rims. REE zoning of clinopyroxene and pseudosection diagrams indicate that only clinopyroxene rims reflect chemical equilibrium with garnet in the reaction front (P = 1.1 ± 0.1 GPa, T = 800 ± 50 °C), whereas the cores retained high-Al contents inherited from precursor gabbronorite clinopyroxene and remained in chemical disequilibrium within a few centimeters of the garnet granulite assemblage. Clinopyroxene of garnet granulites from the Jijal lower GGU are completely re-equilibrated with garnet (P = 1.5 ± 0.1 GPa, T = 800 ± 50 °C). If ferric iron corrections are disregarded, equilibration pressure and temperature are highly overestimated yielding exceedingly high pressures for an island arc setting. The pressure difference between the upper and lower Jijal GGU granulites (~0.4 GPa) and its current thickness (<5 km) implies delamination of the denser parts of Jijal crust. Thermodynamically computed phase diagram sections for upper GGU bulk compositions show that, at the equilibration conditions of Jijal garnet granulite, the equilibrium assemblage is orthopyroxene-free and amphibole-free garnet granulite coexisting with melt or a fluid phase, depending on the water activity at the onset of amphibole breakdown. Pseudosections indicate that hornblende gabbronorite assemblages are highly metastable at lower arc crust depths. The transformation to garnet granulite was therefore substantially

  15. 77 FR 64147 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on October 31, 2012, Room...

  16. 77 FR 68161 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

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    2012-11-15

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on December 5, 2012, Room T-2B3... requested in the March 2012 10 CFR 50.54(f) letters to address Fukushima Near-Term Task Force Report, Task...

  17. 77 FR 74697 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

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    2012-12-17

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on January 18, 2013, Room...

  18. 77 FR 68161 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

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    2012-11-15

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on December 4, 2012, Room...

  19. 78 FR 27442 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

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    2013-05-10

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on May 23, Room T-2B1,...

  20. 77 FR 59676 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on October 3, 2012, Room...

  1. 77 FR 28637 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on May 22- 23, 2012, Room...

  2. 78 FR 17945 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on April 10, 2013, Room T-2B1... requested in the March 2012 10 CFR 50.54(f) letters to address Fukushima Near-Term Task Force Report Task...

  3. 77 FR 45699 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... [Federal Register Volume 77, Number 148 (Wednesday, August 1, 2012)] [Notices] [Page 45699] [FR Doc No: 2012-18757] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima...

  4. 76 FR 27103 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on May 26, 2011, Room T-2B1... Subcommittee will review recent events at the Fukushima site in Japan. The Subcommittee will hear...

  5. 78 FR 65008 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-30

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on November 5, 2013, Room...

  6. 78 FR 50457 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on September 4, 2013, Room...

  7. 78 FR 51752 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on September 18, 2013, Room...

  8. 77 FR 52371 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on September 5, 2012, Room...

  9. 77 FR 31676 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on June 20, 2012, Room...

  10. 76 FR 44377 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on August 16, 2011, Room T-2B1... events at the Fukushima Dai-Ichi reactor site in Japan. The Subcommittee will hear presentations by...

  11. 76 FR 34778 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on June 23, 2011, Room T-2B1... Subcommittee will review recent events at the Fukushima site in Japan. The Subcommittee will hear...

  12. 77 FR 28903 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Fukushima; Notice of Meeting The ACRS Subcommittee on Fukushima will hold a meeting on May 22, 2012, Room...

  13. 75 FR 30077 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ESBWR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ESBWR The ACRS Subcommittee on Economic Simplified Boiling Water Reactor (ESBWR) will hold a meeting on June...

  14. 75 FR 32229 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ABWR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ABWR The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR) will hold a meeting on June 23-24, 2010, Room...

  15. 75 FR 57536 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ABWR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on ABWR The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR) will hold a meeting on October 20, 2010, Room...

  16. 75 FR 66803 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR); Notice of Meeting The ACRS Subcommittee on ABWR will hold a meeting...

  17. 76 FR 68793 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... No: 2011-28737] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic Simplified Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Economic Simplified Boiling Water Reactor (ESBWR) will hold a meeting on November 30,...

  18. 76 FR 34778 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels... room. Dated: June 7, 2011 Cayetano Santos, Chief, Reactor Safety Branch A, Advisory Committee...

  19. 78 FR 31987 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ... COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels..., Technical Support Branch, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  20. 78 FR 37595 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR.... Kathy Weaver, Acting Chief, Technical Support Branch, Advisory Committee on Reactor Safeguards....

  1. 76 FR 27102 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic Simplified Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Economic Simplified Boiling Water Reactor (ESBWR) will hold a meeting on May 26, 2011, Room T-2B1, 11545 Rockville Pike,...

  2. 76 FR 5218 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR); Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor... inconvenience. Dated: January 24, 2011. Antonio Dias, Chief, Reactor Safety Branch B, Advisory Committee...

  3. 76 FR 34276 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-13

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR..., Chief, Reactor Safety Branch A, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  4. 77 FR 59678 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR... Branch, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  5. 76 FR 55718 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels will hold a meeting... (RES) initiative on quantitatively ensuring ``extremely low (XLPR) probability of rupture'' for...

  6. 76 FR 62866 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Economic Simplified Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Economic Simplified Boiling Water Reactor (ESBWR) will hold a meeting on October 21, 2011, Room T-2B1, 11545 Rockville...

  7. 76 FR 72451 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ...-72452] [FR Doc No: 2011-30238] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels will hold a meeting on December 15,...

  8. 76 FR 16016 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of The ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of The ACRS Subcommittee on Materials, Metallurgy And Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy and Reactor...: March 15, 2011. Cayetano Santos, Chief, Reactor Safety Branch A, Advisory Committee on...

  9. 75 FR 58449 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels will hold a meeting... inconvenience. Dated: September 17, 2010. Antonio Dias, Chief, Reactor Safety Branch B, Advisory Committee...

  10. 78 FR 20959 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor The ACRS Subcommittee on Advanced Boiling Water Reactor (ABWR) will hold a meeting.... Antonio Dias, Technical Advisor, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  11. 75 FR 27841 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... Doc No: 2010-11820] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on May 18, 2010, Room T-2B1, 11545...

  12. 78 FR 70597 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Doc No: 2013-28328] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on December 3, 2013, Room...

  13. 77 FR 31044 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-24

    ...] [FR Doc No: 2012-12611] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on June 5, 2012, Room...

  14. 75 FR 82093 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... Doc No: 2010-32822] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on January 11, 2011, Room...

  15. 75 FR 82092 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... Doc No: 2010-32810] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on January 12, 2011, Room...

  16. 75 FR 27840 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... Doc No: 2010-11823] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on May 18, 2010, Room T-2B1, 11545...

  17. 76 FR 44964 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ...] [FR Doc No: 2011-18954] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on August 17, 2011, Room...

  18. Addimer chain structures: Metastable precursors to island formation on Ge Si(0 0 1)-(2 × n) alloyed surface

    NASA Astrophysics Data System (ADS)

    Solis, Kyle J.; Williams, Lance R.; Swartzentruber, B. S.; Han, Sang M.

    2007-01-01

    We have identified addimer chain structures as metastable precursors to compact epitaxial islands on the (2 × n) reconstructed SiGe wetting layer, using polarity-switching scanning tunneling microscopy (STM). These chain structures are comprised of 2-12 addimers residing in the troughs of neighboring substrate dimer rows. The chain structures extend along equivalent <1 3 0> directions across the substrate dimer rows in a zigzag fashion, giving rise to kinked and straight segments. We measure a kink-to-straight ratio of nearly 2:1. This ratio corresponds to a free energy difference of 17 ± 4 meV, favoring the formation of kinked segments. The chain structures convert to compact epitaxial islands at elevated temperatures (⩾90 °C). This conversion suggests that the chain structures are a precursor for compact island formation on the SiGe wetting layer. We digitally process filled- and empty-state STM images to distinguish chain structures from compact islands. By monitoring the populations of both species over time, the chain-to-island conversion rates are measured at substrate temperatures ranging from 90 to 150 °C. The activation energy for the conversion process is measured to be 0.7 ± 0.2 eV with a corresponding pre-exponential factor of 5 × 10 4±2 s -1.

  19. ACR Appropriateness Criteria Crohn Disease.

    PubMed

    Kim, David H; Carucci, Laura R; Baker, Mark E; Cash, Brooks D; Dillman, Jonathan R; Feig, Barry W; Fowler, Kathryn J; Gage, Kenneth L; Noto, Richard B; Smith, Martin P; Yaghmai, Vahid; Yee, Judy; Lalani, Tasneem

    2015-10-01

    Crohn disease is a chronic inflammatory disorder involving the gastrointestinal tract, characterized by episodic flares and times of remission. Underlying structural damage occurs progressively, with recurrent bouts of inflammation. The diagnosis and management of this disease process is dependent on several clinical, laboratory, imaging, endoscopic, and histologic factors. In recent years, with the maturation of CT enterography, and MR enterography, imaging has played an increasingly important role in relation to Crohn Disease. In addition to these specialized examination modalities, ultrasound and routine CT have potential uses. Fluoroscopy, radiography, and nuclear medicine may be less beneficial depending on the clinical scenario. The imaging modality best suited to evaluating this disease may change, depending on the target population, severity of presentation, and specific clinical situation. This document presents seven clinical scenarios (variants) in both the adult and pediatric populations and rates the appropriateness of the available imaging options. They are summarized in a consolidated table, and the underlying rationale and supporting literature are presented in the accompanying narrative. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  20. Degradation of mangrove tissues and implications for peat formation in Belizean island forests

    USGS Publications Warehouse

    Middleton, B.A.; McKee, K.L.

    2001-01-01

    1. Macrofaunal leaf consumption and degradation of leaves, woody twigs and roots were studied in mangrove island forests on a Belizean island. Factors influencing accumulation of organic matter deposited both above and below ground in this oligotrophic, autochothonous system were assessed. 2. Leaf degradation rates of Rhizophora mangle (red mangrove), Avicennia germinans (black mangrove) and Laguncularia racemosa (white mangrove) measured in mesh bags, were much faster in the lower than the upper intertidal zone. Mass loss was most rapid in A. germinans but zonal effects were much larger than species differences. 3. Exposure to invertebrates such as crabs and amphipods tripled overall rates of leaf litter breakdown. In the lower intertidal, crabs completely consumed some unbagged leaves within 23 days. Crabs also had an effect on some upper intertidal sites, where degradation of leaves placed in artificial burrows was 2.4 times faster than when placed on the soil surface. 4. In contrast to leaves (27??5% remaining after 230 days), roots and woody twigs were highly refractory (40??2% and 51??6% remaining after 584 and 540 days, respectively). Root degradation did not vary by soil depth, zone or species. Twigs of R. mangle and A. germinans degraded faster on the ground than in the canopy, whereas those of L. racemosa were highly resistant to decay regardless of position. 5. Peat formation at Twin Cays has occurred primarily through deposition and slow turnover of mangrove roots, rather than above-ground tissues that are either less abundant (woody twigs) or more readily removed (leaves).

  1. Sedimentology of an early Cambrian tide-dominated embayment: Quyuk formation, Victoria Island, Arctic Canada

    NASA Astrophysics Data System (ADS)

    Durbano, Andrew M.; Pratt, Brian R.; Hadlari, Thomas; Dewing, Keith

    2015-05-01

    The early Cambrian (series 2, stage 4) Quyuk formation is exposed in the Minto Inlier of western Victoria Island, Canadian Arctic Islands, and forms the base of the Phanerozoic succession. Coeval with other sandstones of this age in Laurentia, it was deposited in a shallow-marine embayment on a passive margin during the initial phase of the early Paleozoic transgression. Four facies associations are recognized: (1) offshore muds consisting dominantly of dark gray laminated mudstone with discontinuous laminae of medium- to coarse sand; (2) offshore sand dune fields characterized by laterally continuous, planar cross-stratified beds up to 1.4 m thick of medium- to coarse-grained sandstone; (3) distal nearshore consisting dominantly of fine- to medium-grained bioturbated sandstone and fine- to medium-grained sandstone interbedded with laminated mudstone; and (4) proximal nearshore characterized by laterally continuous fine- to medium-grained bioturbated sandstone and medium-grained oolitic ironstone. Large scale dunes of facies association 2 record areas where tidal currents were amplified and had available sediment supply in contrast to facies association 1, which was sediment starved. Dunes are, for the most part, non-bioturbated or contain just a few individual burrows belonging to Skolithos. In nearshore settings, bioturbation in the form of a typical early Cambrian suite of shallow-subtidal ichnofossils predominated, representing a low-diversity Cruziana ichnofacies. Oolitic ironstone horizons in the proximal nearshore mark periods of low sedimentation rates when iron became concentrated and calcite was the primary cementing agent. The coastline is envisaged as a complex of bays and lagoons.

  2. Archean hydrothermal oceanic floor sedimentary environments: DXCL drilling project of the 3.2 Ga Dixon Island Formation, Pilbara, Australia

    NASA Astrophysics Data System (ADS)

    Kiyokawa, S.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Naraoka, H.; Sakamoto, R.; Suganuma, Y.

    2009-12-01

    Many place in Archean greenstone belts have been reported of the black chert to Iron rich sediments above volcanic sequence. The chemical sedimentary sequence has been recognized to form by as hydrothermal siliceous sequence. These sediments contain the hint to understand the Archean ocean and earth surface environments. Here, we will focus the Dixon Island and Cleaverville formations, which are one of the best preserved Archean hydrothermal sedimentary sequence in the world, to recognized detail stratigraphy and restored deep ocean environment. We did scientific drilling, which is called ‘DXCL drilling project’, at 2007 summer. This drilling project had been selected two coastal sites; CL site at lower part of the Cleaverville Formation, and another is DX site at the upper Dixon Island Formation. A systematic combinations of geological, sedimentological, geochemical, and geobiological approaches will be applied to the fresh samples. Here we will show the recent result of this sequence, which will be key evidence to understand the nature of the middle Archean (3.2 Ga) marine environment influenced by hydrothermal activity. The 3.2 Ga Dixon Island -Cleaverville formations composed of volcanic rock units and chemical-volcanosedimentary sequence which are identified by accreted immature island arc setting. The ~350m-thick Dixon Island Formation which is overlie by pillow basalt consists mainly of highly silicified volcanic-siliceous sequences that contain apparent microbial mats and bacterial fossil-like structure within black chert and also includes a komatiite-rhyolite sequences bearing hydrothermal veins. The >300m-thick Cleaverville Formation, which conformably overlay pillow basalt, contains a thick unit of reddish shale, bedded red-white chert and banded iron formation. It partly contains chert fragments-bearing pyroclastic beds. In detail lithology from the drill cores, the CL and DX contain different type of organic rocks. The CL 1 and CL2 core samples

  3. Formation of gas discharging from Taketomi submarine hot spring off Ishigaki Island in the southern Ryukyu Islands, Japan

    NASA Astrophysics Data System (ADS)

    Toki, Tomohiro; Iwata, Daigo; Tsunogai, Urumu; Komatsu, Daisuke D.; Sano, Yuji; Takahata, Naoto; Hamasaki, Hiroshi; Ishibashi, Jun-ichiro

    2017-01-01

    Taketomi submarine hot spring lies off Ishigaki Island in the southern Ryukyu Islands and vents hot spring waters at temperatures up to 50 °C from the seafloor at a depth of 20 m. We investigated the chemical and isotopic composition of gases discharging from Taketomi hot spring. The gases were composed mainly of methane, with secondary nitrogen at higher than atmospheric concentration. Carbon and hydrogen isotope data suggest that the methane in the discharging gases was derived mainly from thermal decomposition of organic matter. Helium isotopes were enriched in 3He relative to the atmosphere, suggesting a supply of mantle-derived helium to the discharging gases. The mantle-derived gases transfer the deep-originated thermal energy to the hot spring and thermogenesis of organic matter. The hydrocarbons in the venting gas could be sourced from sedimentary rocks of the Yaeyama or Shimajiri Groups, or Yaeyama metamorphic rocks, and added to the ascending gases as they pass through those source rocks on their way to the surface. Because the Pleistocene rocks of the Ryukyu Group beneath the hot spring have been altered by the spring activity, the Taketomi hot spring began venting after the Pleistocene.

  4. Petrology and tectonics of Phanerozoic continent formation: From island arcs to accretion and continental arc magmatism

    USGS Publications Warehouse

    Lee, C.-T.A.; Morton, D.M.; Kistler, R.W.; Baird, A.K.

    2007-01-01

    Mesozoic continental arcs in the North American Cordillera were examined here to establish a baseline model for Phanerozoic continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created fringing island arcs just off the Paleozoic continental margin. However, as the age of the Farallon plate at the time of subduction decreased, the extensional environment waned, allowing the fringing island arc to accrete onto the continental margin. With continued subduction, a continental arc was born and a progressively more compressional environment developed as the age of subducting slab continued to young. Refinement into a felsic crust occurred after accretion, that is, during the continental arc stage, wherein a thickened crustal and lithospheric column permitted a longer differentiation column. New basaltic arc magmas underplate and intrude the accreted terrane, suture, and former continental margin. Interaction of these basaltic magmas with pre-existing crust and lithospheric mantle created garnet pyroxenitic mafic cumulates by fractional crystallization at depth as well as gabbroic and garnet pyroxenitic restites at shallower levels by melting of pre-existing lower crust. The complementary felsic plutons formed by these deep-seated differentiation processes rose into the upper crust, stitching together the accreted terrane, suture and former

  5. Formation of 'Beach Rock' at Siesta Key, Florida and its influence on barrier island development

    USGS Publications Warehouse

    Spurgeon, D.; Davis, R.A.; Shinnu, E.A.

    2003-01-01

    Seaward-dipping strata of carbonate-cemented shell debris located along the coast of Siesta Key on the Gulf Coast of the Florida peninsula have long been interpreted to be beachrock equivalent in age to the Pleistocene Anastasia Formation (Stage 5e) of the east coast of Florida. Detailed examination of thin sections along with radiometric dating and isotopic analyses demonstrates clearly that this is a Holocene deposit that is not beachrock but was lithified in a meteoric environment. Whole rock dates, dates from shells only, and from cement only demonstrate that these beach deposits were in place by at least 1800 yr BP and might have been there as long ago as 4300 yr BP. This means that some type of barrier island was in place at that time. Previous investigations have depicted Siesta Key as having a maximum age of 3000 yr with these deposits being located about 2 km landward of the beach deposits. This suggests that the beach deposits might have been the site of the original position of Siesta Key. These data also indicate that sea level must have been near its present position at the time that these foreshore beach deposits were deposited; sometime between 1800 and 4300 yr ago. This scenario indicates that sea level along this coastal reach probably reached its present level at least about 2000 yr ago. ?? 2003 Elsevier B.V. All rights reserved.

  6. Glassy fragmental rocks of Macquarie Island (Southern Ocean): Mechanism of formation and deposition

    NASA Astrophysics Data System (ADS)

    Dickinson, J. A.; Harb, N.; Portner, R. A.; Daczko, N. R.

    2009-04-01

    Glassy fragmental rocks are interlayered with pillow basalt and tabular basalt on Macquarie Island (54°30' S, 158°54' E). These facies formed along the Proto-Macquarie Spreading Ridge between 6 and 12 Ma and have since been uplifted and exposed on the apex of the Macquarie Ridge Complex. Through a combination of field and microscopic analyses, we investigate the submarine production, transportation, deposition and lithification of basalt and sideromelane clasts within a spreading-ridge environment. The findings of this study indicate that these glassy grains form predominantly by cooling-contraction granulation of pillow lava rinds while crystalline basalt clasts are derived from the fragmentation of pillows along concentric and radial cooling joints. Hyaloclastite breccias consist of crystalline volcanic clasts in a matrix of glassy fragments, and are termed pillow-fragment breccias when clasts identifiable as pillows account for > 25% of the cobble-sized fraction. This glassy fragmental sediment was transported predominantly by short-lived grain flows and deposited as a result of syn-eruptive talus accumulation. The above interpretations culminate in the production of a depositional model: these glassy fragmental rocks formed on the slopes of pillow cones following gravitational collapse of a destabilised cone flank along the Proto-Macquarie Spreading Ridge. Scanning electron microscopy reveals that palagonite alteration rims on glassy grains lithify the sediment. The findings may be used as an analogue for the formation of glassy fragmental rocks along past and present mid-oceanic ridges.

  7. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    SciTech Connect

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  8. ACR Appropriateness Criteria on Resectable Rectal Cancer

    SciTech Connect

    Suh, W. Warren; Konski, Andre A.; Mohiuddin, Mohammed; Poggi, Matthew M.; Regine, William F.; Cosman, Bard C.; Saltz, Leonard; Johnstone, Peter A.S.

    2008-04-01

    The American College of Radiology (ACR) Appropriateness Criteria on Resectable Rectal Cancer was updated by the Expert Panel on Radiation Oncology-Rectal/Anal Cancer, based on a literature review completed in 2007.

  9. 7 CFR 760.632 - Payment acres.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... acreage of a crop produced on land that is not eligible for crop insurance or NAP. (h) For any crop acreage for which crop insurance or NAP coverage is canceled, those acres will no longer be considered...

  10. 7 CFR 760.632 - Payment acres.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... acreage of a crop produced on land that is not eligible for crop insurance or NAP. (h) For any crop acreage for which crop insurance or NAP coverage is canceled, those acres will no longer be considered...

  11. 7 CFR 760.632 - Payment acres.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... acreage of a crop produced on land that is not eligible for crop insurance or NAP. (h) For any crop acreage for which crop insurance or NAP coverage is canceled, those acres will no longer be considered...

  12. 7 CFR 760.632 - Payment acres.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... acreage of a crop produced on land that is not eligible for crop insurance or NAP. (h) For any crop acreage for which crop insurance or NAP coverage is canceled, those acres will no longer be considered...

  13. 7 CFR 760.632 - Payment acres.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... acreage of a crop produced on land that is not eligible for crop insurance or NAP. (h) For any crop acreage for which crop insurance or NAP coverage is canceled, those acres will no longer be considered...

  14. A sedimentary model for early Palaeozoic fluvial fans, Alderney Sandstone Formation (Channel Islands, UK)

    NASA Astrophysics Data System (ADS)

    Ielpi, Alessandro; Ghinassi, Massimiliano

    2016-08-01

    Fluvial fans in the rock record are inferred based on critical criteria such as: downstream grain-size fining; evidence for drainage fractionation along bifurcating channels; increasing fluvial-aeolian interaction in the basinward direction; and radial palaeoflow dispersion. Since pre-vegetation fluvial rocks often lack heterolithic alluvium and channelisation at the outcrop scale, the recognition of pre-Silurian fluvial fans has, so far, not been straightforward. This research proposes a sedimentary model for the Alderney Sandstone Formation of Channel Islands (UK), so far considered as a fine record of early Palaeozoic axial-fluvial sedimentation. Here, outcrop-based and remote-sensing analysis of the formation's type-section reveal the interaction of fluvial and aeolian processes, expressed by the alternation of: compound fluvial bars enclosing macroform surfaces, related to phases of perennial discharge; fluvial sandsheets containing antidunal forms and soft-sediment deformations, related to seasonal (i.e. flashy) discharge; and aeolian bedforms overlying thin stream-flow deposits. An up-section increase in aeolian deposits is accompanied by the shrinking of fluvial bars and minor-channel cuts, suggesting that drainage was fractioned along smaller channels terminating into marginal aeolian environments. Together with a propensity towards more dispersed values of fluvial cross-set thickness up-section (again due to discharge fractionation along intermittently active channels), these features depict an aeolian-influenced fluvial fan. This work discusses a set of criteria for the identification of fluvial fans in pre-vegetation environments. In doing so, it also explores possible parallels to modern environments, and underscores the potential of integrated outcrop and remotely sensed observations on ancient fluvial rocks and modern sedimentary realms.

  15. The Automated Conflict Resolution System (ACRS)

    NASA Technical Reports Server (NTRS)

    Kaplan, Ted; Musliner, Andrew; Wampler, David

    1993-01-01

    The Automated Conflict Resolution System (ACRS) is a mission-current scheduling aid that predicts periods of mutual interference when two or more orbiting spacecraft are scheduled to communicate with the same Tracking and Data Relay Satellite (TDRS) at the same time. The mutual interference predicted has the potential to degrade or prevent communications. Thus the ACRS system is a useful tool for aiding in the scheduling of Space Network (SN) communications.

  16. 30,000 Degrees: Steps toward the Formation of a Staten Island Higher Education Partnership

    ERIC Educational Resources Information Center

    Fanuzzi, Robert; Gold, Kenneth; Seigel, Samantha; Cuccia, Christopher; Kress, Michael; Sanchez, Sandy

    2015-01-01

    In order to confront lower than average completion rates in New York City and to provide a strong economic and civic foundation for Staten Island, the borough's three institutions of higher education, College of Staten Island/City University of New York, St. John's University, and Wagner College, have brought together their high school and…

  17. Geodetic implications on block formation and geodynamic domains in the South Shetland Islands, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Berrocoso, M.; Fernández-Ros, A.; Prates, G.; García, A.; Kraus, S.

    2016-01-01

    The South Shetland Islands archipelago is dynamically complex due to its tectonic surroundings. Most islands are part of a formerly active volcanic arc, although Deception, Penguin and Bridgeman Islands, as well as several submarine volcanoes, are characterized by active back-arc volcanism. Geodetic benchmarks were deployed and the movement of the lithosphere to which they were fixed measured to provide geodynamic insight for the South Shetland Islands, Bransfield Basin and Antarctic Peninsula area based on surface deformation. These benchmarks' data add spatial and temporal coverage to previous results. The results reveal two different geodynamic patterns, each confined to a distinct part of the South Shetland Islands archipelago. The inferred absolute horizontal velocity vectors for the benchmarks in the northeastern part of the archipelago are consistent with the opening of the Bransfield Basin, while benchmark vectors in the southwestern part of the archipelago are similar to those of the benchmarks on the Antarctic Peninsula. In between, Snow, Deception and Livingston Islands represent a transition zone. In this area, the horizontal velocity vectors relative to the Antarctic plate shift northeastwards from N to NW. Furthermore, the South Shetland Islands benchmarks, except for that at Gibbs (Elephant) Islands, indicate subsidence, which might be a consequence of the slab roll-back at the South Shetland Trench. In contrast, the uplift revealed by the Antarctic Peninsula benchmarks suggests glacial isostatic adjustment after the Larson B ice-shelf breakup.

  18. 78 FR 79019 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ..., Metallurgy & Reactor Fuels; Notice of Meeting The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels... materials and metallurgy. The Subcommittee will hear presentations by and hold discussions with the...

  19. Processes of fluvial island formation, with examples from plum creek, Colorado and Snake River, Idaho

    USGS Publications Warehouse

    Osterkamp, W.R.

    1998-01-01

    A fluvial island is a landform, elevated above and surrounded by stream-channel branches or waterways, that persists sufficiently long to establish permanent vegetation. Natural fluvial islands occur in any part of a drainage network but most commonly in montane, piedmont-valley, and coastal flood-plain environments. Processes, often interactive, by which islands form include avulsion (the sudden separation of land by a flood or by an abrupt change in the course of a stream), rapid and gradual channel incision, channel migration, dissection of both rapidly and slowly deposited bed sediment, and deposition of bed sediment on a vegetated surface or behind a channel obstruction. Products of high-energy conditions, fluvial islands typically lack stability over decades to millennia. Fluvial islands in Plum Creek, Colorado, USA, results of sorting processes following a recent high-magnitude flood, and in the Snake River, Idaho, USA, partly results of the Pleistocene Bonneville Flood, illustrate how islands form, develop, and disappear. The examples consider differing conditions of island shape, size, height, sediment, and vegetation.

  20. Assessing the origin of unusual organic formations in lava caves from Canary Islands (Spain)

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; de la Rosa, Jose M.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Jurado, Valme; Fernández, Octavio; Knicker, Heike; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes, like other caves, contain a variety of speleothems formed in the initial stage of a lava tube formation or due to leaching and subsequent precipitation of secondary minerals. Primary and secondary mineral formations in lava caves are mainly composed of silicate minerals, although secondary minerals common in limestone caves have been also reported in this type of caves. In addition, unusual colored deposits have been found on the walls and ceilings of lava tubes, some of them of unknown origin and composition. A brown to black-colored mud-like deposits was observed in "Llano de los Caños" Cave, La Palma Island, Canary Islands, Spain. These black deposits coat the wall and ceiling of the lava tube where sub-horizontal fractures occur. FESEM-EDS, X-ray micro-computed tomography and mineralogical analyses were conducted for morphological, 3D microstructural and compositional characterization of these unusual speleothem samples. These techniques revealed that they are mainly composed of amorphous materials, suggesting an organic carbon composition. Hence, analytical pyrolysis (Py-GC/MS), solid-state 13C Nuclear Magnetic Resonance (NMR) and stable isotope analysis were applied to assess the nature and origin of the black deposits. The combination of these analytical tools permits the identification of specific biomarkers (di- and triterpenoids) for tracing the potential sources of the organic compounds in the speleothems. For comparison purposes, samples from the topsoil and overlaying vegetation were also analyzed. Chromatograms resulting from the Py-GC/MS showed an abundance of polysaccharides, lipids and terpenoids typically derived from the vegetation of the area (Erica arborea). In addition, levoglucosan, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected. They probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. The lack of the typical pattern of odd

  1. Shelf sedimentation across Precambrian-Cambrian boundary: Chapel Island Formation, southeastern Newfoundland

    SciTech Connect

    Myrow, P.

    1985-02-01

    The upper Precambrian-Lower Cambrian Chapel Island Formation consists of medium- and fine-grained siliciclastics and minor limestones that record the early evolution of shelly fossils and complex trace fossils. Deposition of these Avalonian sediments occurred in a variety of shelf environments. Temporal and spatial changes in the conditions of sedimentation during the deposition of this sequence resulted in a wide spectrum of sedimentary and biogenic structures. Facies transitional with underlying terrestrial and shallow-marine red beds were deposited in foreshore and upper-shoreface settings under tidal influence and display tidal channels, shrinkage cracks (desiccation and synaersis), abundant current ripples (bimodal-bipolar current distribution), and phosphatic nodules. Sandstones and siltstones deposited in shoreface to outer-shelf settings contain evidence of storm and wave reworking. Features present include: gutter casts, thin granule lag zones, phosphate nodules, slump-fold zones, hummocky cross-stratified beds,and thin to medium-grained sandstones with sharp bases and gradational tops, wave-rippled upper surfaces, climbing wave ripple laminations, and draping laminations. These features indicate deposition on a storm- and wave-dominated shelf with locally variable topography. Thick massive siltstone beds and pebbly mudstones are interpreted as debris flows formed on a gentle slope. Red and green mudstones, nodular limestones, and medium to thick (up to 60 cm) limestones were deposited during periods of low siliciclastic input. The limestone beds - micrites to packed biomicrites - contain oncolitic and planar stromatolites, sheet-crack cavities (containing the oldest known coelobiontic fauna), iron-manganese encrusted surfaces, authigenic barite, mudcracks, intraformational and extraformational conglomerate layers, and small channels. These are interpreted as intertidal and supratidal deposits.

  2. Mechanisms of ring and island formation in lattice mismatched droplet epitaxy

    NASA Astrophysics Data System (ADS)

    DeJarld, M.; Reyes, Kris; Smereka, P.; Millunchick, J. M.

    2013-04-01

    Lattice mismatched GaSb nanostructures were grown using droplet epitaxy. In this method, liquid Ga droplets are deposited on GaAs substrates and then exposed to a Sb flux at various temperatures. At increasing temperature and droplet volumes, the morphologies changed from two-dimensional islands to nanoholes, three-dimensional islands, rings, and clusters of islands. A theoretical model describes the relationship between the volume of the droplet and the final nanostructure, and is validated by kinetic Monte Carlo simulations. The combined experimental and simulation results demonstrate another process to obtain complex nanostructures, widening the design window for devices.

  3. 77 FR 45699 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Economic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... [Federal Register Volume 77, Number 148 (Wednesday, August 1, 2012)] [Notices] [Pages 45699-45700] [FR Doc No: 2012-18759] NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Economic Simplified Boiling Water Reactors (ESBWR); Notice of...

  4. Origin of "island dolostones": A case study from the Cayman Formation (Miocene), Cayman Brac, British West Indies

    NASA Astrophysics Data System (ADS)

    Zhao, Hongwen; Jones, Brian

    2012-01-01

    Cayman Brac, the easternmost of the Cayman Islands, is 19 km long, 1.5 to 3 km wide, and rises ~ 40 m above sea level at its eastern end. Geographically isolated by the deep oceanic waters of the Caribbean Sea, this island, with its thick succession of pervasively dolomitized Tertiary rocks, is a natural laboratory for assessing the origin of "island dolostones". Dolostones in the Miocene Cayman Formation (~ 100 m thick), with most crystals < 20 μm long, are formed of low-Ca calcian dolomite (LCD — < 55 mol% CaCO 3) and lesser amounts of high-Ca Calcian dolomite (HCD — > 55 mol% CaCO 3). Geochemically, they are characterised by δ 13C values of 1.6 to 3.5‰, δ 18O values of 2.3-4.0‰, 80-279 ppm Sr, 52-340 ppm Fe, and 9-82 ppm Mn. The inverse correlation between δ 18O and mol% CaCO 3 and positive correlation between Sr and mol% CaCO 3 largely reflect kinetic effects on oxygen isotope fractionation and the Sr partition behaviour between dolomite and water. Dolomite stoichiometry indicates formation from waters with a high Mg/Ca ratio and δ 18O values, corrected for biases associated with dolomite stoichiometry and phosphoric acid fractionation, indicate formation from normal seawater-like fluids under near surface conditions. The 87Sr/ 86Sr ratios point to two phases of dolomitization. Phase I, in the Late Miocene (6-8 Ma), caused partial dolomitization of the basal part of the Cayman Formation. Phase II, during the Pliocene to Early Pleistocene (1-5 Ma), completed dolomitization of the Cayman Formation. Both phases of dolomitization were mediated by similar fluids. Although available information suggests that dolomitization was probably linked to sea level fluctuations, the timing of dolomitization relative to the transgressive-regressive cycle remains open to debate.

  5. Topographic and geomorphologic controls on the distribution of vegetation formations in Elephant Point (Livingston Island, Maritime Antarctica).

    PubMed

    Ruiz-Fernández, Jesús; Oliva, Marc; García-Hernández, Cristina

    2017-06-01

    This article focuses on the spatial distribution of vegetation formations in Elephant Point, an ice-free area of 1.16km(2) located in Livingston Island (South Shetland Islands, Antarctica). Fieldwork carried out in January 2014 consisted of floristic surveys and designation of a vegetation map. We have examined these data in a GIS environment together with topographical and geomorphological features existing in the peninsula in order to infer the factors controlling vegetation distribution. This has allowed quantifying the total area covered by the four different vegetation formations distributed across the peninsula, proliferating mainly on bedrock plateaus and Holocene raised beaches. Grass formation is essentially composed of Deschampsia antarctica, distributed almost exclusively on raised beaches, and covering 4.1% of the ice-free surface. The remaining three formations are fundamentally composed of cryptogam species. The first of which is fruticose lichen and moss formation, present on high bedrock plateaus and principally formed by lichens such as Usnea aurantiaco-atra. The next is the crustose lichen formation, spreading on bedrock plateaus near the coast populated by bird colonies. In this case, ornitocoprophilous lichens such as Caloplaca regalis, Xanthoria elegans and Haematomma erythromma are predominant. Together, both formations have colonised 5.1% of the peninsula. The last variety, moss carpet and moss cushion formation, occupies 1.4% of the deglaciated surface, spreading primarily in flooded areas, stabilised talus slopes, and bedrock plateaus as well. Therefore, the total surface colonised by vegetation is 12.2ha, which comprises 10.5% of the peninsula. Due to the retreat of the Rotch Dome glacier, 20.1ha remain ice-free since 1956 (17.3% of the deglaciated area). Ever since, even though the Antarctic Peninsula has registered one of the most significant temperature rises on Earth, vegetation has only colonised 0.04ha of this new space, which merely

  6. Arc magmatism at the incipient stage of formation of subduction zone: geochemistry of Eocene volcanic rocks from the Bonin Islands

    NASA Astrophysics Data System (ADS)

    Kanayama, K.; Umino, S.; Ishizuka, O.

    2009-12-01

    Bonin Islands are known for the occurrence of boninite series and high-Mg arc tholeiite and calk-alkaline rock series generated at the incipient stage of formation of subduction zone. We present new analysis of major and trace elements and petrogenetic processes of volcanic rocks of the Bonin Islands. Boninite series rocks in Chichijima and Mukojima Island Group represent the primitive arc magmatism in middle Eocene time, which gave way to arc tholeiite and calk-alkaline rocks are in Hahajima Island Groups. Boninite series of the Maruberiwan and Asahiyama Formations indicates a differentiation trend that sharply increases in FeO*/MgO (0.47-32) with increasing SiO2 contents (53.8-78.2 wt %). FeO*/MgO ratios (0.74-4.19) of arc tholeiite and calk-alkaline rocks of the Hahajima Island Group are slightly lower than those of the Izu-Bonin Quaternary volcanic front lavas. Boninite series samples of the Mikazukiyama Formation show a similar trend to the Maruberiwan-Asahiyama boninite series samples. However, the former has lower SiO2 contents (55.7-58.2 wt %), and higher FeO*/MgO ratios (1.05-1.98) than the latter. Most of the Maruberiwan and Mikazukiyama boninites belong to low-Ca type, while only a small number of Maruberiwan boninite samples belong to high-Ca type. Maruberiwan boninites (MgO>8 wt%) are the most depleted in REEs (Yb=0.36-1.01 ppm), which is only about 1/10 of N-MORBs, and the most enriched in LILEs (Rb=6-23, Ba=6-58 ppm) in the Bonin Islands. Low-Ca boninites indicate a distinct positive anomaly of Zr and negative anomalies of Sm and Ti ((Sm/Zr)n=0.45-0.78, (Ti/Zr)n=0.25-0.64), while high-Ca boninites indicate moderate anomalies of these elements ((Sm/Zr)n=0.79-1.29, (Ti/Zr)n=0.57-1.02). Basalts of the Hahajima Island Group are the most enriched in REEs (Yb=1.2-2.4 ppm) and HFSEs (Nb=0.47-1.75 ppm) in the Bonin Islands. Compared to the Hahajima basalts, the present Izu-Bonin front lavas are more depleted in LREEs and HFSE, and enriched in LILEs

  7. Evidence for coral island formation during rising sea level in the central Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Kench, Paul S.; Owen, Susan D.; Ford, Murray R.

    2014-02-01

    The timing and evolution of Jabat Island, Marshall Islands, was investigated using morphostratigraphic analysis and radiometric dating. Results show the first evidence of island building in the Pacific during latter stages of Holocene sea level rise. A three-phase model of development of Jabat is presented. Initially, rapid accumulation of coarse sediments on Jabat occurred 4800-4000 years B.P. across a reef flat higher than present level, as sea level continued to rise. During the highstand, island margins and particularly the western margin accreted vertically to 2.5-3.0 m above contemporary ridge elevations. This accumulation phase was dominated by sand-size sediments. Phase three involved deposition of gravel ridges on the northern reef, as sea level fell to present position. Jabat has remained geomorphically stable for the past 2000 years. Findings suggest reef platforms may accommodate the oldest reef islands in atoll systems, which may have profound implications for questions of prehistoric migration through Pacific archipelagos.

  8. Tracing formation and durability of calcite in a Punic-Roman cistern mortar (Pantelleria Island, Italy).

    PubMed

    Dietzel, Martin; Schön, Frerich; Heinrichs, Jens; Deditius, Artur P; Leis, Albrecht

    2016-01-01

    Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the

  9. The Expanding Significance of One Acre.

    ERIC Educational Resources Information Center

    Gilbert, Daniel R., Jr.

    2003-01-01

    A management class assignment requires students to study the history and complexity of one acre of land. The intent is to develop connections between the natural environment and human acts of management, focusing on the concept of privilege. (Contains 15 references.) (SK)

  10. 75 FR 57536 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Thermal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... Hydraulic Phenomena The ACRS Subcommittee on Thermal Hydraulic Phenomena will hold a meeting on October 18... 5 p.m. The Subcommittee will review the thermal-hydraulic research activities in the Office...

  11. 76 FR 11525 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... and Probabilistic Risk Assessment (PRA); Notice of Meeting The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA), Room T-2B1, 11545 Rockville Pike, Rockville, Maryland. The entire...

  12. 76 FR 22934 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... and Probabilistic Risk Assessment; Notice of Meeting The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA) will hold a meeting on May 11, 2011, Room T-2B3, 11545 Rockville...

  13. 76 FR 18586 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... and Probabilistic Risk Assessment (PRA); Notice of Meeting The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA) will hold a meeting on April 20, 2011, Room T-2B1, 11545 Rockville...

  14. 76 FR 71609 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... and Probabilistic Risk Assessment; Notice of Meeting The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA) will hold a meeting on December 14, 2011, Room T-2B3, 11545 Rockville...

  15. 76 FR 32240 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on June 7, 2011, Room T-2B1, 11545 Rockville Pike,...

  16. Breccia Formation at a Complex Impact Crater: Slate Islands, Lake Superior, Ontario, Canada

    NASA Technical Reports Server (NTRS)

    Dressler, B. O.; Sharpton, V. L.

    1997-01-01

    The Slate Islands impact structure is the eroded remnant of a approximately 30-32 km-diameter complex impact structure located in northern Lake Superior, Ontario, Canada. Target rocks are Archean supracrustal and igneous rocks and Proterozoic metavolcanics, metasediments, and diabase. A wide variety of breccias occurs on the islands, many of which contain fragments exhibiting shock metamorphic features. Aphanitic, narrow and inclusion-poor pseudotachylite veins, commonly with more or less parallel boundaries and apophyses branching off them, represent the earliest breccias formed during the compression stage of the impact process. Coarse-grained, polymictic elastic matrix breccias form small to very large, inclusion-rich dikes and irregularly shaped bodies that may contain altered glass fragments. These breccias have sharp contacts with their host rocks and include a wide range of fragment types some of which were transported over minimum distances of approximately 2 km away from the center of the structure. They cut across pseudotachylite veins and contain inclusions of them. Field and petrographic evidence indicate that these polymictic breccias formed predominantly during the excavation and central uplift stages of the impact process. Monomictic breccias, characterized by angular fragments and transitional contacts with their host rocks, occur in parautochthonous target rocks, mainly on the outlying islands of the Slate Islands archipelago. A few contain fragmented and disrupted, coarse-grained, polymictic clastic matrix breccia dikes. This is an indication that at least some of these monomictic breccias formed late in the impact process and that they are probably related to a late crater modification stage. A small number of relatively large occurrences of glass-poor, suevitic breccias occur at the flanks of the central uplift and along the inner flank of the outer ring of the Slate Islands complex crater. A coarse, glass-free, allogenic breccia, containing

  17. Fast Formation of Magnetic Islands in a Plasma in the Presence of Counterstreaming Electrons

    SciTech Connect

    Califano, F.; Attico, N.; Pegoraro, F.; Bertin, G.; Bulanov, S. V.

    2001-06-04

    With the help of 2D-3V (two dimensional in space and three dimensional in velocity) Vlasov simulations we show that the magnetic field generated by the electromagnetic current filamentation instability develops magnetic islands due to the onset of a fast reconnection process that occurs on the electron dynamical time scale. This process is relevant to magnetic channel coalescence in relativistic laser plasma interactions.

  18. Multiple secondary islands formation in nonlinear evolution of double tearing mode simulations

    NASA Astrophysics Data System (ADS)

    Guo, W.; Ma, J.; Yu, Z.

    2017-03-01

    A new numerical code solving the conservative perturbed resistive magnetohydrodynamic (MHD) model is developed. Numerical tests of the ideal Kelvin-Helmholtz instability and the resistive double tearing mode (DTM) show its capability in solving linear and nonlinear MHD instabilities. The nonlinear DTM evolution in 2D geometry is numerically investigated with low guiding field B z 0 , short half-distance y 0 between the equilibrium current sheets, and small resistivity η. The interaction of islands on the two initial current sheets may generate an unstable flow driven current sheet with a high length-to-thickness aspect ratio (α), and multiple secondary islands can form. In general, the length-to-thickness aspect ratio α and the number of secondary islands increase with decreasing guide field B z 0 , decreasing half-distance y 0 , and increasing Lundquist number of the flow driven current sheet S L although the dependence may be non-monotonic. The reconnection rate dependence on S L , B z 0 , and y 0 is also investigated.

  19. Formation of U-depleted rhyolite from a basanite at El Hierro, Canary Islands

    NASA Astrophysics Data System (ADS)

    Sigmarsson, Olgeir; Laporte, Didier; Carpentier, Marion; Devouard, Bertrand; Devidal, Jean-Luc; Marti, Joan

    2013-03-01

    Phonolite and trachyte are the felsic magmas of the alkaline magma suites, which characterize the Canary Islands. The October 2011 submarine eruption off El Hierro, the westernmost island, nevertheless, produced a small volume of rhyolitic magma. The rhyolite occurred as highly vesicular, white coloured pumices enveloped in and mingled with darker coloured basanitic pumice. The basanitic pumice is relatively crystal poor with a few euhedral olivines (mostly Fo77-79), clinopyroxenes and Fe-rich spinels, whereas very rare olivine of same composition is found together with equally rare Fe-sulphide and FeTi-rich oxides in the rhyolite. The Fe-Mg exchange equilibrium in the oxides permits to calculate an equilibrium temperature of 970-890 °C for the rhyolite, in agreement with quartz-melt equilibrium at ca. 930 °C. A striking mineralogical feature of the rhyolite is the presence of rounded to contorted grains of milky quartz, which are xenocrysts incorporated and partly dissolved into the magma. Analyses of residual volatile concentrations in the glasses show that the rhyolite melt was highly degassed, whereas the basanitic glass still has important halogen concentrations. Trace element patterns of the mafic glasses and their elevated incompatible element concentrations are typical of the western Canary Island basanites. In contrast, the trace element composition of the rhyolite shows surprisingly low concentrations for all elements except the most incompatible ones (e.g. Rb, Ba, K and Th). All other measured LILE, HFSE and REE have significantly lower concentration than the basanitic counterpart that can be explained by fractionation of accessory phases (1 % apatite, 1 % sphene and 0.1 % zircon). Surprisingly, low U concentration is presumably related to elevated oxygen fugacity in the rhyolite, causing U to be in a hexavalent state, and fluxing of F-rich gas leading to volatilization of UF6, known to emanate at low temperature. The results suggest that a gas

  20. Sedimentation and diagenesis along open and island-protected windward carbonate platform margins of the Cretaceous El Abra Formation, Mexico

    NASA Astrophysics Data System (ADS)

    Minero, Charles J.

    1991-05-01

    The windward margin of the mid-Cretaceous Valles-San Luis Potosi carbonate platform in northeastern Mexico included open and island-protected segments. Depositional environments and diagenesis vary markedly with margin type. Sand shoals near the windward open margin are composed of oncoid-bioclastic and cross-laminated carbonates. Increasingly restricted and finer lagoonal and tidal-flat environments occurred bankwards, recording gradually decreasing wave and current energy. Lithofacies include peloid-miliolid, cryptalgal laminite, lime mudstone, and molluscan carbonates. Islands along the windward margin are composed of rudistid-skeletal debris from adjacent reefs. Lagoonal to tidal-flat sediments were deposited bankwards. Similar lithofacies occur as in these environments along the open margin but they are muddier and contain less diverse fauna. The different energy regimes along the margin influenced the distribution and packaging of banktop sediments. The bankward transition to low-energy, restricted environments was gradual across the open margin. In contrast, muddy sediments with restricted fauna accumulated in close proximity to the island-protected margin. Non-cyclic vertical lithofacies successions characterized the open platform margin, whereas asymmetric shoaling-upward sequences characterized the island-protected margin. Early diagenesis along the open margin was minor; burial diagenesis was of major importance. Thin rinds of marine cement are widespread but meteoric diagenesis was minor. Burial promoted extensive compaction. Mg-rich connate brines expressed from Guaxcama gypsum resulted in dolomitization and lithification, thereby precluding further compaction. Pore fluids resulting from dehydration of Guaxcama gypsum to anhydrite yielded pore-filling and replacement anhydrite in the El Abra Formation. Burial and Laramide deformation (Maastrichtian-Paleocene) resulted in stylolitization and extensive fracturing. Uplift produced widespread meteoric

  1. 7 CFR 1412.44 - Notification of base acres.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Notification of base acres. 1412.44 Section 1412.44... through 2012 § 1412.44 Notification of base acres. The operator and owners of record of a farm will be notified in writing of the number of base acres eligible for enrollment in a contract, unless such...

  2. 7 CFR 1412.44 - Notification of base acres.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Notification of base acres. 1412.44 Section 1412.44... through 2012 § 1412.44 Notification of base acres. The operator and owners of record of a farm will be notified in writing of the number of base acres eligible for enrollment in a contract, unless such...

  3. 7 CFR 1412.21 - Election of base acres.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Election of base acres. 1412.21 Section 1412.21... CROP REVENUE ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Base Acres for a Farm for Covered Commodities § 1412.21 Election of base acres. (a) Subject to adjustments in...

  4. 7 CFR 1412.44 - Notification of base acres.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Notification of base acres. 1412.44 Section 1412.44... Through 2012 § 1412.44 Notification of base acres. The operator and owners of record of a farm will be notified in writing of the number of base acres eligible for enrollment in a contract, unless such...

  5. 7 CFR 1412.21 - Election of base acres.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Election of base acres. 1412.21 Section 1412.21... CROP REVENUE ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Base Acres for a Farm for Covered Commodities § 1412.21 Election of base acres. (a) Subject to adjustments in...

  6. 7 CFR 1412.21 - Election of base acres.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Election of base acres. 1412.21 Section 1412.21... CROP REVENUE ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Base Acres for a Farm for Covered Commodities § 1412.21 Election of base acres. (a) Subject to adjustments in...

  7. 7 CFR 1412.44 - Notification of base acres.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Notification of base acres. 1412.44 Section 1412.44... through 2012 § 1412.44 Notification of base acres. The operator and owners of record of a farm will be notified in writing of the number of base acres eligible for enrollment in a contract, unless such...

  8. 7 CFR 1412.44 - Notification of base acres.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Notification of base acres. 1412.44 Section 1412.44... Through 2012 § 1412.44 Notification of base acres. The operator and owners of record of a farm will be notified in writing of the number of base acres eligible for enrollment in a contract, unless such...

  9. 7 CFR 1412.21 - Election of base acres.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Election of base acres. 1412.21 Section 1412.21... CROP REVENUE ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Base Acres for a Farm for Covered Commodities § 1412.21 Election of base acres. (a) Subject to adjustments in...

  10. 7 CFR 1412.21 - Election of base acres.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Election of base acres. 1412.21 Section 1412.21... CROP REVENUE ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Base Acres for a Farm for Covered Commodities § 1412.21 Election of base acres. (a) Subject to adjustments in...

  11. 75 FR 51501 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Planning and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Planning and Procedures The ACRS Subcommittee on Planning and Procedures will hold a meeting on September 8, 2010, at... conduct of the meeting, persons planning to attend should check with these references if such...

  12. 75 FR 67783 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Planning and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-03

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Planning and Procedures The ACRS Subcommittee on Planning and Procedures will hold a meeting on December 1, 2010, in Room... conduct of the meeting, persons planning to attend should check with these references if such...

  13. 77 FR 4838 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-31

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S. Evolutionary Power Reactor (U.S. EPR); Notice of Meeting The ACRS Subcommittee on U.S. Evolutionary Power Reactor (U.S. EPR) will hold a meeting on...

  14. 77 FR 74696 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on AP-1000...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on AP-1000; Notice of Meeting The ACRS Subcommittee on AP-1000 will hold a meeting on January 18, 2013, Room...

  15. 76 FR 44964 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... No: 2011-18952] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S. Evolutionary Power Reactor; Notice of Meeting The ACRS Subcommittee on U.S. Evolutionary Power Reactor (U.S. EPR) will hold a meeting on August 18, 2011, Room...

  16. 77 FR 61791 - Advisory Committee On Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee On US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ... COMMISSION Advisory Committee On Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee On US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on October 18- 19, 2012, Room T... review Chapter 4, ``Reactor,'' of the Safety Evaluation Reports associated with the US-APWR...

  17. 77 FR 73497 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on January 15, 2013, Room T-2B3... Reports are associated with the design certification of the US-APWR. The Subcommittee will...

  18. 77 FR 56240 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on September 20, 2012, Room...

  19. 78 FR 47802 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on September 17-18, 2013, Room T... Chapter 6, ``Engineered Safety Features,'' of the Safety Evaluation Report (SER) associated with the...

  20. 78 FR 59076 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on October 1, 2013, Room T-2B1... the US-APWR design. The Subcommittee will hear presentations by and hold discussions...

  1. 78 FR 20959 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on US-APWR The ACRS Subcommittee on US-APWR will hold a meeting on April 25- 26, 2013, Room T-2B1, 11545 Rockville..., ``Instrumentation and Control,'' of the Safety Evaluation Report (SER) associated with the US-APWR...

  2. 78 FR 68867 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on US-APWR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on US-APWR; Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on November 20-21, 2013, Room T... the Safety Evaluation Report (SER) associated with the US-APWR design certification and the...

  3. 78 FR 17945 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant Designs; Notice of Meeting The ACRS Subcommittee on Future Plant Designs will hold a meeting on April 9... based licensing framework for the Next Generation Nuclear Plant (NGNP). The Subcommittee will...

  4. 75 FR 58448 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Future Plant Designs The ACRS Subcommittee on Future Plant Designs will hold a meeting on October 21, 2010, at 11545... Subcommittee will review current Design Acceptance Criteria associated with Digital Instrumentation and...

  5. 76 FR 5220 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant Designs The ACRS Subcommittee on Future Plant Designs will hold a meeting on February 9, 2011, at...

  6. 76 FR 64123 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-17

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant Designs; Notice of Meeting The ACRS Subcommittee on Future Plant Designs will hold a meeting on November...

  7. 77 FR 74698 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant Designs; Notice of Meeting The ACRS Subcommittee on Future Plant Designs will hold a meeting on January 17... Generation Nuclear Plant (NGNP) fuel and source term research and development of risk-informed...

  8. 76 FR 16016 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Future Plant Designs The ACRS Subcommittee on Future Plant Designs will hold a meeting on April 5, 2011, at...

  9. 78 FR 50457 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Digital I&C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Digital I&C; Notice of Meeting The ACRS Subcommittee on Digital I&C will hold a briefing on September 19, 2013, Room T... identification of digital system failure modes and use of hazard analysis methods for digital safety systems....

  10. 75 FR 30077 - Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Digital I&C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... COMMISSION Advisory Committee On Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee On Digital I&C Systems The ACRS Subcommittee on Digital Instrumentation and Control (DI&C) Systems will hold a meeting on... Digital Instrumentation and Control (DI&C) Probabilistic Risk Assessment (PRA). Topics will include...

  11. 77 FR 67688 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C; Notice of Meeting The ACRS Subcommittee on Digital I&C will hold a meeting on November 16, 2012, Room...

  12. 76 FR 7882 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C Systems The ACRS Subcommittee on Digital Instrumentation & Control (DI&C) Systems will hold a meeting...

  13. 75 FR 51499 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C Systems The ACRS Subcommittee on Digital Instrumentation and Controls (I&C) Systems will hold a meeting on...--8:30 a.m. until 12 p.m. The Subcommittee will review Digital I&C Interim Staff Guidance on...

  14. Sea level rise and inundation of island interiors: Assessing impacts of lake formation and evaporation on water resources in arid climates

    NASA Astrophysics Data System (ADS)

    Gulley, J. D.; Mayer, A. S.; Martin, J. B.; Bedekar, V.

    2016-09-01

    Coasts of many low-lying islands will be inundated should sea level rise by 1 m by 2100 as projected, thereby decreasing water resources through aquifer salinization. A lesser known impact occurs if rising sea level elevates water tables above interior topographic lows to form lakes. Impacts of lake formation on water resources, however, remain unquantified. Here we use hydrological models, based on islands in the Bahamian archipelago, to demonstrate that on islands with negative water budgets, evaporation following lake inundation can cause more than twice the loss of fresh groundwater resources relative to an equivalent amount of coastal inundation. This result implies that in dry climates, low-lying islands with inland depressions could face substantially greater threats to their water resources from sea level rise than previously considered.

  15. Mechanism for persistent hexagonal island formation in AlN buffer layer during growth on Si (111) by plasma-assisted molecular beam epitaxy

    SciTech Connect

    Hsu, K.-Y.; Chung, H.-C.; Liu, C.-P.; Tu, L.-W.

    2007-05-21

    The characteristics of structure and morphology of AlN grown by a growth interruption method on Si (111) with plasma-assisted molecular beam epitaxy are investigated. It is found that the growth interruption method would improve the surface flatness of the AlN layer without the formation of Al droplets. However, AlN hexagonal islands were present and persistent throughout the entire growth owing to effective strain relaxation and Eherlich-Schowebel barrier effect of preexistent surface islands grown on higher terraces of the Si substrate. The density of threading dislocations underneath the hexagonal islands is much less than elsewhere in the film, which is presumably due to dislocation annihilation during the island growth process.

  16. Constructability -- from Qinshan to the ACR

    SciTech Connect

    Elgohary, Medhat; Fairclough, Neville; Ricciuti, Rick

    2003-09-01

    Atomic Energy of Canada Limited (AECL) has recognized the importance of constructability for many years, and it is applying its principals to CANDU projects with increasing success. The CANDU 6 Nuclear Power Plant has been constructed eleven times in the last 25 years. However, the last two units completed on the Qinshan project in China have employed some very innovative construction methods that have not been used on the previous units. In order to make nuclear power generation more competitive, shorter construction schedules and reduced project cost and risks are essential objectives. The application of constructability principles is a major contributor to achieving these objectives. The success of Qinshan has increased the confidence in the new construction methods, which are being implemented on the ACR (Advanced CANDU Reactor) successfully. An ACR construction strategy that utilizes advanced construction techniques has been developed by AECL. The strategy includes paralleling of activities by using extensive modularization and the vertical installation of equipment and modules into the reactor building using a VHL (Very Heavy Lift) crane. This strategy allows short schedules to be met with a minimum risk to the project.

  17. 76 FR 34276 - Advisory Committee on Reactor Safeguards (ACRS), Meeting of the ACRS Subcommittee on Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-13

    ... with Inventory and Certification of digital systems, operating experience for digital systems, and... Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on June 22, 2011, Room T-2B3, 11545 Rockville Pike,...

  18. 76 FR 55717 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... and Probabilistic Risk Assessment The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA) will hold a meeting on September 20, 2011, Room T-2B1, 11545 Rockville Pike, Rockville... Modifying the Risk-Informed Regulatory Guidance for New Reactors. The Subcommittee will hear...

  19. 77 FR 60480 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on October 30, 2012, Room T-2B1, 11545 Rockville Pike... and discuss the Design Specific Review Standard (DSRS) for Instrumentation and Control of the...

  20. 76 FR 52715 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Instrumentation and Control Systems; Notice of Meeting The ACRS Subcommittee on Digital Instrumentation and Control Systems (DI&C) will hold a meeting on September 7, 2011, Room T-2B1, 11545 Rockville Pike... Diversity on Defense-In-Depth in Digital Computer-Based I&C Systems,'' and other related activities...

  1. 75 FR 61781 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Reliability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... and PRA The ACRS Subcommittee on Reliability and Probabilistic Risk Assessment (PRA) will hold a... statement on Safety Culture. The Subcommittee will hear presentations by and hold discussions with...: September 30, 2010. Antonio Dias, Chief, Reactor Safety Branch B, Advisory Committee on Reactor...

  2. Processes controlling the remobilization of surficial sediment and formation of sedimentary furrows in north-central Long Island Sound

    USGS Publications Warehouse

    Poppe, L.J.; Knebel, H. J.; Lewis, R.S.; DiGiacomo-Cohen, M. L.

    2002-01-01

    Sidescan sonar, bathymetric, subbottom, and bottom-photographic surveys and sediment sampling have improved our understanding of the processes that control the complex distribution of bottom sediments and benthic habitats in Long Island Sound. Although the deeper (>20 m) waters of the central Sound are long-term depositional areas characterized by relatively weak bottom-current regimes, our data reveal the localized presence of sedimentary furrows. These erosional bedforms occur in fine-grained cohesive sediments (silts and clayey silts), trend east-northeast, are irregularly spaced, and have indistinct troughs with gently sloping walls. The average width and relief of the furrows is 9.2 m and 0.4 m, respectively. The furrows average about 206 m long, but range in length from 30 m to over 1,300 m. Longitudinal ripples, bioturbation, and nutclam shell debris are common within the furrows. Although many of the furrows appear to end by gradually narrowing, some furrows show a "tuning fork" joining pattern. Most of these junctions open toward the east, indicating net westward sediment transport. However, a few junctions open toward the west suggesting that oscillating tidal currents are the dominant mechanism controlling furrow formation. Sedimentary furrows and longitudinal ripples typically form in environments which have recurring, directionally stable, and occasionally strong currents. The elongate geometry and regional bathymetry of Long Island Sound combine to constrain the dominant tidal and storm currents to east-west flow directions and permit the development of these bedforms. Through resuspension due to biological activity and the subsequent development of erosional bedforms, fine-grained cohesive sediment can be remobilized and made available for transport farther westward into the estuary.

  3. Processes controlling the remobilization of surficial sediment and formation of sedimentary furrows in North-Central Long Island Sound

    USGS Publications Warehouse

    Poppe, L.J.; Knebel, H. J.; Lewis, R.S.; DiGiacomo-Cohen, M. L.

    2002-01-01

    Sidescan sonar, bathymetric, subbottom, and bottom-photographic surveys and sediment sampling have improved our understanding of the processes that control the complex distribution of bottom sediments and benthic habitats in Long Island Sound. Although the deeper (>20 m) waters of the central Sound are long-term depositional areas characterized by relatively weak bottom-current regimes, our data reveal the localized presence of sedimentary furrows. These erosional bedforms occur in fine-grained cohesive sediments (silts and clayey silts), trend east-northeast, are irregularly spaced, and have indistinct troughs with gently sloping walls. The average width and relief of the furrows is 9.2 m and 0.4 m, respectively. The furrows average about 206 m long, but range in length from 30 m to over 1,300 m. Longitudinal ripples, bioturbation, and nutclam shell debris are common within the furrows. Although many of the furrows appear to end by gradually narrowing, some furrows show a "tuning fork" joining pattern. Most of these junctions open toward the east, indicating net westward sediment transport. However, a few junctions open toward the west suggesting that oscillating tidal currents are the dominant mechanism controlling furrow formation. Sedimentary furrows and longitudinal ripples typically form in environments which have recurring, directionally stable, and occasionally strong currents. The elongate geometry and regional bathymetry of Long Island Sound combine to constrain the dominant tidal and storm currents to east-west flow directions and permit the development of these bedforms. Through resuspension due to biological activity and the subsequent development of erosional bedforms, fine-grained cohesive sediment can be remobilized and made available for transport farther westward into the estuary.

  4. Geodynamic settings of microcontinents, non-volcanic islands and submerged continental marginal plateau formation

    NASA Astrophysics Data System (ADS)

    Dubinin, Evgeny; Grokholsky, Andrey; Makushkina, Anna

    2016-04-01

    Complex process of continental lithosphere breakup is often accompanied by full or semi isolation of small continental blocks from the parent continent such as microcontinents or submerged marginal plateaus. We present different types of continental blocks formed in various geodynamic settings. The process depends on thermo-mechanical properties of rifting. 1) The continental blocks fully isolated from the parent continent. This kind of blocks exist in submerged form (Elan Bank, the Jan-Mayen Ridge, Zenith Plateau, Gulden Draak Knoll, Batavia Knoll) and in non-submerged form in case of large block size. Most of listed submerged blocks are formed in proximity of hot-spot or plume. 2) The continental blocks semi-isolated from the parent continent. Exmouth Plateau, Vøring, Agulhas, Naturaliste are submerged continental plateaus of the indicated category; Sri Lanka, Tasmania, Socotra are islands adjacent to continent here. Nowadays illustration of this setting is the Sinai block located between the two continental rifts. 3) The submerged linear continental blocks formed by the continental rifting along margin (the Lomonosov Ridge). Suggested evolution of this paragraph is the rift propagation along existing transtensional (or another type) transform fault. Future example of this type might be the California Peninsula block, detached from the North American plate by the rifting within San-Andreas fault. 4) The submerged continental blocks formed by extensional processes as the result of asthenosphere flow and shear deformations. Examples are submerged blocks in the central and southern Scotia Sea (Terror Bank, Protector Basin, Discovery Bank, Bruce Bank etc.). 5) The continental blocks formed in the transform fault systems originated in setting of contradict rifts propagation in presence of structure barriers, rifts are shifted by several hundreds kilometers from each other. Examples of this geodynamic setting are Equatorial Atlantic at the initial development stage

  5. MO-AB-207-04: ACR Update in Mammography

    SciTech Connect

    Berns, E.

    2015-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, computed tomography, nuclear medicine, and mammography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR Accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process. To understand the requirements of the ACR nuclear medicine accreditation program, and the role of the physicist in annual equipment surveys and the set up and supervision of the routine QC program. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program.

  6. MO-AB-207-01: ACR Update in CT

    SciTech Connect

    McNitt-Gray, M.

    2015-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, computed tomography, nuclear medicine, and mammography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR Accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process. To understand the requirements of the ACR nuclear medicine accreditation program, and the role of the physicist in annual equipment surveys and the set up and supervision of the routine QC program. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program.

  7. MO-AB-207-02: ACR Update in MR

    SciTech Connect

    Price, R.

    2015-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, computed tomography, nuclear medicine, and mammography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR Accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process. To understand the requirements of the ACR nuclear medicine accreditation program, and the role of the physicist in annual equipment surveys and the set up and supervision of the routine QC program. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program.

  8. ACR Appropriateness Criteria colorectal cancer screening.

    PubMed

    Yee, Judy; Kim, David H; Rosen, Max P; Lalani, Tasneem; Carucci, Laura R; Cash, Brooks D; Feig, Barry W; Fowler, Kathryn J; Katz, Douglas S; Smith, Martin P; Yaghmai, Vahid

    2014-06-01

    Colorectal cancer is the third leading cause of cancer deaths in the United States. Most colorectal cancers can be prevented by detecting and removing the precursor adenomatous polyp. Individual risk factors for the development of colorectal cancer will influence the particular choice of screening tool. CT colonography (CTC) is the primary imaging test for colorectal cancer screening in average-risk individuals, whereas the double-contrast barium enema (DCBE) is now considered to be a test that may be appropriate, particularly in settings where CTC is unavailable. Single-contrast barium enema has a lower performance profile and is indicated for screening only when CTC and DCBE are not available. CTC is also the preferred test for colon evaluation following an incomplete colonoscopy. Imaging tests including CTC and DCBE are not indicated for colorectal cancer screening in high-risk patients with polyposis syndromes or inflammatory bowel disease. This paper presents the updated colorectal cancer imaging test ratings and is the result of evidence-based consensus by the ACR Appropriateness Criteria Expert Panel on Gastrointestinal Imaging. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  9. Effects of island-edge exchange barrier on 2D pattern formation in surfactant-mediated epitaxy

    NASA Astrophysics Data System (ADS)

    Wang, Dai-mu; Sun, Xia; Wu, Zi-qin

    2001-11-01

    The nucleation and growth of two-dimensional islands in a surfactant-mediated epitaxy system have been studied by computer simulation. To improve the recent results published in the literature, we use a configuration-dependent energy barrier for the exchange process at the island edge in our model. The simulations produce fractal islands at high temperatures or low deposition fluxes and a transition to regular compact islands occurs at lower temperatures or higher fluxes, in good agreement with the recent experimental results. The barrier for the island-edge exchange has quite a strong effect on the island density as a function of temperature and flux. A small change of the island-edge exchange barrier induces a large variation of the island density in the low-temperature or high-flux region. The flux-dependent island density shows a clear scaling-law behaviour in the intermediate-flux region. The scaling exponent increases evidently as the island-edge exchange barrier increases.

  10. Geoarchaeology of a 'drowning' island: geomorphologic formation and prehistoric human habitation of Funafuti Atoll, Tuvalu

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Kobayashi, R.

    2012-12-01

    There seem to be a variety to vulnerability of atolls. In fact our archaeological investigations of Majuro in Marshall and Funafuti in Tuvalu revealed diverse duration of human settlement histories. The most reliable charcoal ages for earliest human habitation on Oceanic atolls were obtained from Majuro Atoll, which date back to 1800 - 2000 yr. BP, but radiocarbon ages of charcoal samples retrieved from Funafuti and Vaitupu suggest that Tuvalu were inhabited around ca. 500 yr. BP. It should be helpful to examine geomorphic formation of each atoll islet in considering this temporal difference of human settlement histories. During the mid-Holocene period, the paleoreef had grown up to reach the highstand sea level over the bedrock of Pleistocene limestone. The emergence of the Holocene reef is estimated around 2000 yr. BP in the central Pacific, which is viewed as a trigger of depositional process of atoll islets. There is, however, the possibility that the process was not uniform and sedimentation of foraminiferal sand and coral shingle was affected with more local conditions. Several results of our geoarchaeological excavations in Fongafale, Funafuti Atoll, would be related with this topic. Synthesizing them with the late 18th century's topographic information reported by the Royal Society of London, I then discuss a tentative scenario of geomorphologic formation and prehistoric human settlement of Fongafale. The diversity of human settlement histories could be an indicator of the relative vulnerability of atoll islets.

  11. Deposition of rheomorphic ignimbrite D (Mogán Formation), Gran Canaria, Canary Islands, Spain

    NASA Astrophysics Data System (ADS)

    Kobberger, Gustav; Schmincke, Hans-Ulrich

    Rheomorphic ignimbrite D (13.4Ma, Upper Mogán Formation on Gran Canaria), a multiple flow-single cooling unit, is divided into four major structural zones that differ in fabric and finite strain of deformed pyroclasts. Their structural characteristics indicate contrasting deformation mechanisms during rheomorphic flow. The zones are: (a) a basal zone (vitrophyre) with pure uniaxial flattening perpendicular to the foliation; (b) an overlying shear zone characterized by asymmetric fabrics and a significantly higher finite strain, with an ellipsoid geometry similar to stretched oblate bodies; (c) a central zone with a finite strain geometry similar to that of the underlying shear zone but without evidence of a rotational strain component; and (d) a slightly deformed to non-deformed top zone where the almost random orientation of subspherical pyroclasts suggests preservation of original, syn-depositional clast shapes. Rheomorphic flow in D is the result of syn- to post-depositional remobilization of a hot pyroclastic flow as shown by kinematic modeling based on: (a) the overall vertical structural zonation suggested by finite strain and fabric analysis; (b) the relation of shear sense to topography; (c) the interrelationship of the calculated vertical cooling progression at the base of the flow (formation of vitrophyre) and the related vertical changes in strain geometry; (d) the complex lithification history; and (e) the consequent mechanisms of deformational flow. Rheomorphic flow was caused by load pressure due to an increase in the vertical accumulation of pyroclastic material on a slope of generally 6-8°. We suggest that every level of newly deposited pyroclastic flow material of D first passed through a welding process that was dominated by compaction (pure flattening) before rheomorphic deformation started.

  12. Heme oxygenase-1 deficiency alters erythroblastic island formation, steady-state erythropoiesis and red blood cell lifespan in mice.

    PubMed

    Fraser, Stuart T; Midwinter, Robyn G; Coupland, Lucy A; Kong, Stephanie; Berger, Birgit S; Yeo, Jia Hao; Andrade, Osvaldo Cooley; Cromer, Deborah; Suarna, Cacang; Lam, Magda; Maghzal, Ghassan J; Chong, Beng H; Parish, Christopher R; Stocker, Roland

    2015-05-01

    Heme oxygenase-1 is critical for iron recycling during red blood cell turnover, whereas its impact on steady-state erythropoiesis and red blood cell lifespan is not known. We show here that in 8- to 14-week old mice, heme oxygenase-1 deficiency adversely affects steady-state erythropoiesis in the bone marrow. This is manifested by a decrease in Ter-119(+)-erythroid cells, abnormal adhesion molecule expression on macrophages and erythroid cells, and a greatly diminished ability to form erythroblastic islands. Compared with wild-type animals, red blood cell size and hemoglobin content are decreased, while the number of circulating red blood cells is increased in heme oxygenase-1 deficient mice, overall leading to microcytic anemia. Heme oxygenase-1 deficiency increases oxidative stress in circulating red blood cells and greatly decreases the frequency of macrophages expressing the phosphatidylserine receptor Tim4 in bone marrow, spleen and liver. Heme oxygenase-1 deficiency increases spleen weight and Ter119(+)-erythroid cells in the spleen, although α4β1-integrin expression by these cells and splenic macrophages positive for vascular cell adhesion molecule 1 are both decreased. Red blood cell lifespan is prolonged in heme oxygenase-1 deficient mice compared with wild-type mice. Our findings suggest that while macrophages and relevant receptors required for red blood cell formation and removal are substantially depleted in heme oxygenase-1 deficient mice, the extent of anemia in these mice may be ameliorated by the prolonged lifespan of their oxidatively stressed erythrocytes.

  13. Initiation and early evolution of the Franklin magmatic event preserved in the 720 Ma Natkusiak Formation, Victoria Island, Canadian Arctic

    NASA Astrophysics Data System (ADS)

    Williamson, Nicole M. B.; Ootes, Luke; Rainbird, Robert H.; Bédard, Jean H.; Cousens, Brian

    2016-03-01

    Our understanding of the onset and evolution of flood basalt volcanism is rooted in the study of the character and internal architecture of its eruptive products. Neoproterozoic continental flood basalts of the ca. 720 Ma Franklin magmatic event are preserved as the Natkusiak Formation and are exposed within the Minto Inlier on Victoria Island, Northwest Territories, Canada. The 200 m volcanic succession evaluated in this study has features similar to those of other continental flood basalt provinces and consists of four volcanic units: a basal unit of laterally discontinuous flows with evidence for lava-sediment interactions, a mafic volcaniclastic deposit emplaced as a mass flow, a quartz-rich volcanic sandstone that records the re-establishment of small river channels, and a unit of thick, high-titanium tholeiitic sheet flows that mark the onset of the main phase of flood volcanism. The basal units show marked lateral thickness variations that imply the existence of paleotopography during their eruption and/or deposition. In addition, two newly discovered volcanic vent complexes within the Natkusiak succession preserve the products of explosive, vent-forming basaltic pyroclastic fall eruptions. Differences in major element geochemistry between the basal and upper basaltic flow units, in conjunction with the lithological characteristics of each volcanic unit, are used to correlate the units on a scale of over 100 km from the south of the Minto Inlier to the north.

  14. Tectonic significance of large-scale chaotic deposits in a Cretaceous fore-arc basin: Valle Formation, Cedros Island (Mexico)

    SciTech Connect

    Smith, D.P.; Busby-Spera, C.J. )

    1990-05-01

    A mappable, deep-marine slide deposit (olistostrome) within medial-Cretaceous fore-arc basin strata (Valle Formation), located on Cedros Island, Baja California Norte, records the initiation of intrabasinal faulting. Studies of both modern and ancient olistostromes show that olistostromes can form in all physiographic provinces (including shelf and abyssal plain) and tectonic settings of the marine environment. A variety of triggering mechanisms have been suggested for olistostromes, including tectonism, sea level changes, diapirism, rapid sedimentation that overloads steep slopes, migration of gas hydrates, or combinations of the above. The olistostrome in the Valle Formation ranges in thickness from 0 to at least 180 m, and extends areally for at least 34 km{sup 2}. It can be divided into two parts. The basal 30-40 m contains large (up to 8 m) angular blocks (allolistoliths) derived from the Jurassic substrate. The allolistoliths decrease in abundance upsection, whereas internally coherent intraformational slide blocks (endolistoliths), which reach tens of meters in width, increase. Beds composing the endolistoliths are alternating mudstone and sandstone turbidites that were deposited on a tectonically stable basin plain or rise setting before catastrophic failure of the sedimentary pile produced the olistostrome. Intrabasinal faulting is invoked as a cause of the sediment failure because of the presence of allolistoliths, which must have been shed into the basin from uplifted( ) basin floor scarps. Allolistoliths occur sporadically throughout at least 400 m of coarse-clastic sediment gravity-flow deposits that cap the olistostrome, suggesting that intrabasinal faulting continued to affect the basin long after the olistrostrome formed.

  15. Recent coastal evolution in a carbonate sandy environments and relation to beach ridge formation: the case of Anegada, British Virgin Islands

    NASA Astrophysics Data System (ADS)

    Cescon, Anna Lisa; Cooper, J. Andrew G.; Jackson, Derek W. T.

    2014-05-01

    In a changing climate context coastal areas will be affected by more frequent extreme events. Understanding the relationship between extreme events and coastal geomorphic response is critical to future adaptation plans. Beach ridge landforms commonly identified as hurricane deposits along tropical coasts in Australia and in the Caribbean Sea. However their formative processes in such environments are still not well understood. In particular, the role of different extreme wave events (storm waves, tsunami waves and extreme swell), in generating beach ridges is critical to their use as palaeotempestology archives. Anegada Island is a carbonate platform situated in the British Virgin Island between the Atlantic Ocean and the Caribbean Sea. Pleistocene in age, Anegada is surrounded by the Horseshoe fringing coral reef. Two Holocene sandy beach ridge plains are present on the western part of the island. The north beach ridge plain is Atlantic facing and has at least 30 ridges; the south beach ridge plain is Caribbean Sea facing and contains 10 ridges. Historical aerial photos enabled the shoreline evolution from 1953 to 2012 to be studied. Three different coastal domains are associate with the beach ridge plains: strong east-west longshore transport affects the north coastline, the south-west coastline from West End to Pomato Point represents an export corridor for these sediments and finally, along the southern coastline, from Pomato Point to Settling Point the area presents a depositional zone with little to no change in the last 70 years. The link between the extreme wave events that have affected Anegada Island in the last 70 years and beach ridge creation is discussed. Hurricane Donna crossed over Anegada Island in 1960: its geomorphological signature is tracked in the shoreline change analysis and its implication in beach ridge formation is discussed. Anegada Island has also been impacted by tsunami waves (Atwater et al., 2012) and a comparative discussion of the

  16. ACR Appropriateness Criteria Right Upper Quadrant Pain

    PubMed Central

    Yarmish, Gail M.; Smith, Martin P.; Rosen, Max P.; Baker, Mark E.; Blake, Michael A.; Cash, Brooks D.; Hindman, Nicole M.; Kamel, Ihab R.; Kaur, Harmeet; Nelson, Rendon C.; Piorkowski, Robert J.; Qayyum, Aliya; Tulchinsky, Mark

    2015-01-01

    Acute right upper quadrant pain is a common presenting symptom in patients with acute cholecystitis. When acute cholecystitis is suspected in patients with right upper quadrant pain, in most clinical scenarios, the initial imaging modality of choice is ultrasound. Although cholescintigraphy has been shown to have slightly higher sensitivity and specificity for diagnosis, ultrasound is preferred as the initial study for a variety of reasons, including greater availability, shorter examination time, lack of ionizing radiation, morphologic evaluation, confirmation of the presence or absence of gallstones, evaluation of bile ducts, and identification or exclusion of alternative diagnoses. CT or MRI may be helpful in equivocal cases and may identify complications of acute cholecystitis. When ultrasound findings are inconclusive, MRI is the preferred imaging test in pregnant patients who present with right upper quadrant pain. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. PMID:24485592

  17. ACR appropriateness criteria right upper quadrant pain.

    PubMed

    Yarmish, Gail M; Smith, Martin P; Rosen, Max P; Baker, Mark E; Blake, Michael A; Cash, Brooks D; Hindman, Nicole M; Kamel, Ihab R; Kaur, Harmeet; Nelson, Rendon C; Piorkowski, Robert J; Qayyum, Aliya; Tulchinsky, Mark

    2014-03-01

    Acute right upper quadrant pain is a common presenting symptom in patients with acute cholecystitis. When acute cholecystitis is suspected in patients with right upper quadrant pain, in most clinical scenarios, the initial imaging modality of choice is ultrasound. Although cholescintigraphy has been shown to have slightly higher sensitivity and specificity for diagnosis, ultrasound is preferred as the initial study for a variety of reasons, including greater availability, shorter examination time, lack of ionizing radiation, morphologic evaluation, confirmation of the presence or absence of gallstones, evaluation of bile ducts, and identification or exclusion of alternative diagnoses. CT or MRI may be helpful in equivocal cases and may identify complications of acute cholecystitis. When ultrasound findings are inconclusive, MRI is the preferred imaging test in pregnant patients who present with right upper quadrant pain. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  18. Complex Explosive Phonolitic Volcanism From Tenerife, Canary Islands: the Diego Hernandez Formation

    NASA Astrophysics Data System (ADS)

    Olin, P. H.; Edgar, C. J.; Wolff, J. A.; Nichols, H. J.; Cas, R.; Marti, J.

    2001-12-01

    The Diego Hernandez Formation (DHF) consists of several phonolitic pyroclastic packages erupted between 0.53 and 0.196 Ma. Here we focus on the most intense period of DHF explosive phonolitic activity, from 0.32 - 0.28 Ma, during which three major plinian sequences with intraplinian ignimbrites, respectively the Aldea (0.320 +/- 0.008 Ma), Fasnia (0.309 +/- 0.012 Ma) and Poris Members (0.276 +/- 0.016 Ma) were emplaced. A minor disconformity, representing a pause of perhaps a few weeks' duration, separates lower and upper parts of the Fasnia Member. Volumes are difficult to estimate due to substantial offshore deposition, but each of the three has a minimum volume of a few cubic kilometers DRE. The dominant phonolite component in all three units shows broad chemical variations that suggest a similar magmatic lineage. However, details of trace element covariations do not support evolution of phonolite from a common parent, while the order of extraction of different compositions within a single eruption is complex. The Aldea and the lower Fasnia contain highly evolved phonolitic pumice (Zr up to 2,000 ppm), variably mixed with mafic and intermediate magmatic components. Plinian fall units in the upper Fasnia have little admixed mafic material yet are significantly less evolved than preceeding units (Zr = 850 - 1500 ppm), and show overall normal compositional zoning. However, highly evolved phonolite reappears towards the end of the Fasnia eruption sequence, and is more abundant in interbedded ignimbrites than in plinian fall units. The Poris Member contains phonolite similar to the least evolved compositions in the upper Fasnia, with a minor population of a much less differentiated phonolite (Zr = 600 - 650 ppm) that has little affinity with the the rest of the sequence, but resembles magmas erupted during a later DHF cycle. Both Poris phonolite types mingled with basaltic liquid. The repeated eruption of multiple felsic magmas with distinct trace element signatures

  19. Photochemical Formation of Fe(II) and Peroxides in Coastal Seawater Collected around Okinawa Island, Japan - Impact of Red Soil Pollution

    NASA Astrophysics Data System (ADS)

    Okada, K.; Nakajima, H.; Higuchi, T.; Fujimura, H.; Arakaki, T.; Taira, H.

    2003-12-01

    In a study to elucidate the impacts of red soil pollution on the oxidizing power of seawater, photochemical formation of Fe(II) and peroxides was studied in seawaters collected around Okinawa Island, Japan. The northern part of Okinawa Island suffers from red soil pollution which is caused mainly by land development such as pineapple farming and the construction of recreational facilities. We studied photochemical formation of peroxides and Fe(II) in the same seawater samples because the reaction between HOOH and Fe(II) forms hydroxyl radical (OH radical), the most potent environmental oxidant. Photochemical formation of Fe(II) was fast and reached steady-state in 30 minutes of simulated sunlight illumination and the steady-state Fe(II) concentrations were about 80% of total iron concentrations. Photochemical formation of peroxides was relatively slow and formation kinetics varied, depending on the initial peroxide concentrations. Because photochemical formation of peroxides was faster and total iron concentrations in the red soil polluted seawater were higher, red soil polluted seawater is expected to have greater oxidizing power than seawater that is not polluted with red soil.

  20. 7 CFR 1412.23 - Base acres and Conservation Reserve Program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Base acres and Conservation Reserve Program. 1412.23... Base Acres for a Farm for Covered Commodities § 1412.23 Base acres and Conservation Reserve Program. (a... of production flexibility contract acres or base acres protected by a Conservation Reserve...

  1. 7 CFR 1412.23 - Base acres and Conservation Reserve Program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Base acres and Conservation Reserve Program. 1412.23... Base Acres for a Farm for Covered Commodities § 1412.23 Base acres and Conservation Reserve Program. (a... of production flexibility contract acres or base acres protected by a Conservation Reserve...

  2. 7 CFR 1412.23 - Base acres and Conservation Reserve Program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Base acres and Conservation Reserve Program. 1412.23... Base Acres for a Farm for Covered Commodities § 1412.23 Base acres and Conservation Reserve Program. (a... of production flexibility contract acres or base acres protected by a Conservation Reserve...

  3. 7 CFR 1412.23 - Base acres and Conservation Reserve Program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Base acres and Conservation Reserve Program. 1412.23... Base Acres for a Farm for Covered Commodities § 1412.23 Base acres and Conservation Reserve Program. (a... of production flexibility contract acres or base acres protected by a Conservation Reserve...

  4. 76 FR 61118 - Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor...

  5. 76 FR 22140 - Parker River and Thacher Island National Wildlife Refuges, Essex County, MA; Comprehensive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... River NWR, 6 Plum Island Turnpike, Newburyport, MA 01950. In-Person Drop-off: You may drop off comments during regular business hours or call for an appointment (978-465-5753) at Parker River NWR, 6 Plum.... The refuge occupies 4,653 acres on Plum Island, a 9-mile-long barrier island off the...

  6. 43 CFR 19.3 - Reviews of roadless areas and roadless islands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... islands. 19.3 Section 19.3 Public Lands: Interior Office of the Secretary of the Interior WILDERNESS PRESERVATION National Wilderness Preservation System § 19.3 Reviews of roadless areas and roadless islands. (a... acres or more and every roadless island in the national wildlife refuges and game ranges of the...

  7. 43 CFR 19.3 - Reviews of roadless areas and roadless islands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... islands. 19.3 Section 19.3 Public Lands: Interior Office of the Secretary of the Interior WILDERNESS PRESERVATION National Wilderness Preservation System § 19.3 Reviews of roadless areas and roadless islands. (a... acres or more and every roadless island in the national wildlife refuges and game ranges of the...

  8. 43 CFR 19.3 - Reviews of roadless areas and roadless islands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... islands. 19.3 Section 19.3 Public Lands: Interior Office of the Secretary of the Interior WILDERNESS PRESERVATION National Wilderness Preservation System § 19.3 Reviews of roadless areas and roadless islands. (a... acres or more and every roadless island in the national wildlife refuges and game ranges of the...

  9. 43 CFR 19.3 - Reviews of roadless areas and roadless islands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... islands. 19.3 Section 19.3 Public Lands: Interior Office of the Secretary of the Interior WILDERNESS PRESERVATION National Wilderness Preservation System § 19.3 Reviews of roadless areas and roadless islands. (a... acres or more and every roadless island in the national wildlife refuges and game ranges of the...

  10. 43 CFR 19.3 - Reviews of roadless areas and roadless islands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... islands. 19.3 Section 19.3 Public Lands: Interior Office of the Secretary of the Interior WILDERNESS PRESERVATION National Wilderness Preservation System § 19.3 Reviews of roadless areas and roadless islands. (a... acres or more and every roadless island in the national wildlife refuges and game ranges of the...

  11. 130. Julian Price Memorial Park. Fortyseven acre Julian Price Lake ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    130. Julian Price Memorial Park. Forty-seven acre Julian Price Lake created by an impoundment. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  12. Gap-fill type HSQ/ZEP520A bilayer resist process-(II): HSQ island and spacer formation

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Su; Gu, Pei-Yi; Kao, Ming-Jer; Tsai, Ming-Jinn

    2008-03-01

    Hydrogen silsesquioxane (HSQ) bilayer resist (BLR) processes are attractive to obtain nano-sized features with high aspect ratio by dry-transferring thin e-beam pattern to thick underlayer to strengthen the etch resistance. However, there are drawbacks of high e-beam dosage for HSQ patterning and difficulty in controlling the underlayer resist profile by O2 plasma with anisotropic etching. In this study gap-fill type HSQ/ZEP520A BLR processes were studied to overcome these problems. The advantage of gap-fill type BLR processes is that the dosage for patterning on thick ZEP520A e-beam positive resist is not as high as that for HSQ and the resist profile can be tuned by exposure and development processes without depending on O2 plasma. By gap-filling of HSQ in ZEP520A trench patterns and then stripping ZEP520A by O2 plasma the tone is conversed from trench to line. The gap filling quality attributes include (1) the void size and number of HSQ lines and (2) spacer adhesion on HSQ line edge. Only the non-diluted HSQ solution could completely fill the trench and the HSQ line formed after stripping of ZEP520A. The spacer formed by diluted HSQ is found to be composed of oxide without any ZEP520A-related elements by FTIR analysis. The ZEP520A trench CD monotonically increases with decrease of W/L ratio. The HSQ line CD also follows the same trend. The extension of HSQ in ZEP520A, i.e. HSQ line CD minus ZEP520A trench CD, basically follows the reverse trend. It is therefore concluded that extension of HSQ lines in ZEP520A and HSQ spacers are formed from the diffused HSQ in trench sidewall without any reaction with ZEP520A. Voids were generally observed at the bottom of the HSQ line. Size and quantity of voids are larger for lower W/L ratios, indicating that the voids were formed due to insufficient HSQ volume for gap-filling. Increasing e-beam dose, baking or reflow temperature, and reflow of ZEP520A before HSQ coating could reduce the void formation. Multiple gap

  13. Formation of Island Arc-Trench System due to Plate Subduction on the Basis of Elastic Dislocation Theory

    NASA Astrophysics Data System (ADS)

    Fukahata, Y.; Matsu'ura, M.

    2015-12-01

    The most conspicuous cumulative deformation in subduction zones is the formation of island arc-trench system. A pair of anomalies in topography and free-air gravity, high in the arc and low around the trench, is observed without exceptions all over the world. Since the 1960s, elastic dislocation theory has been widely used to interpret coseismic crustal deformation. For the modeling of longer-term crustal deformation, it is necessary to consider viscoelastic properties of the asthenosphere. By simply applying elastic-viscoelastic dislocation theory to plate subduction, Matsu'ura and Sato (1989, GJI) have shown that some crustal deformation remains after the completion of one earthquake cycle, which means that crustal deformation accumulates with time in a long term due to plate subduction. In fact, by constructing a plate interface model in and around Japan, Hashimoto, Fukui and Matsu'ura (2004, PAGEOPH) have demonstrated that the computed vertical displacements due to steady plate subduction well explain the observed free-air gravity anomaly pattern. Recently, we got a lucid explanation of crustal deformation due to plate subduction. In subduction zones, oceanic plates bend and descend into the mantle. Because the bending of oceanic plates is usually not spontaneous, there exists kinematic interaction between the oceanic and overriding plates, which causes cumulative deformation of the overriding plate. This may be understood based on the law of action and reaction: one is bending of an oceanic plate and the other is deformation of the overriding plate. As a special case, it is useful to consider plate subduction along a part of true circle. In this case, crustal deformation due to steady subduction is solely caused by the effect of gravity, because dislocation along a circle does not cause any intrinsic internal deformation. When an oceanic plate is descending along an arcuate plate interface from the right-hand side, according to dislocation theory, the oceanic

  14. 75 FR 66401 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... Pressurized-Water Reactor (US-APWR); Notice of Meeting The ACRS Subcommittee on US-APWR will hold a meeting on... Evaluation report (SER) associated with the US-APWR design certification. The Subcommittee will...

  15. Investigation of island formation due to RMPs in DIII-D plasmas with the SIESTA resistive MHD equilibrium code

    SciTech Connect

    Hirshman, S. P.; Shafer, M. W.; Seal, S. K.; Canik, J. M.

    2016-03-03

    The SIESTA magnetohydrodynamic (MHD) equilibrium code has been used to compute a sequence of ideally stable equilibria resulting from numerical variation of the helical resonant magnetic perturbation (RMP) applied to an axisymmetric DIII-D plasma equilibrium. Increasing the perturbation strength at the dominant m=2, n=-1 , resonant surface leads to lower MHD energies and increases in the equilibrium island widths at the m=2 (and sidebands) surfaces, in agreement with theoretical expectations. Island overlap at large perturbation strengths leads to stochastic magnetic fields which correlate well with the experimentally inferred field structure. The magnitude and spatial phase (around the dominant rational surfaces) of the resonant (shielding) component of the parallel current are shown to change qualitatively with the magnetic island topology.

  16. Investigation of island formation due to RMPs in DIII-D plasmas with the SIESTA resistive MHD equilibrium code

    DOE PAGES

    Hirshman, S. P.; Shafer, M. W.; Seal, S. K.; ...

    2016-03-03

    The SIESTA magnetohydrodynamic (MHD) equilibrium code has been used to compute a sequence of ideally stable equilibria resulting from numerical variation of the helical resonant magnetic perturbation (RMP) applied to an axisymmetric DIII-D plasma equilibrium. Increasing the perturbation strength at the dominant m=2, n=-1 , resonant surface leads to lower MHD energies and increases in the equilibrium island widths at the m=2 (and sidebands) surfaces, in agreement with theoretical expectations. Island overlap at large perturbation strengths leads to stochastic magnetic fields which correlate well with the experimentally inferred field structure. The magnitude and spatial phase (around the dominant rational surfaces)more » of the resonant (shielding) component of the parallel current are shown to change qualitatively with the magnetic island topology.« less

  17. Heat Islands

    EPA Pesticide Factsheets

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  18. Gullies on Mars: Clues to Their Formation Timescale from Possible Analogs from Devon Island, Nunavut, Arctic Canada

    NASA Technical Reports Server (NTRS)

    McKay, C. P.; Lee, P.; Matthews, J.

    2002-01-01

    The origin and evolution of the youthful gully features on Mars remain enigmatic. Field investigations of possible analogs from Devon Island, Arctic, suggest that the terrestrial features are <104 years old and result from melting of surface ice. Additional information is contained in the original extended abstract.

  19. 7 CFR 1412.23 - Base acres and Conservation Reserve Program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Base acres and Conservation Reserve Program. 1412.23... Base Acres for a Farm for Covered Commodities § 1412.23 Base acres and Conservation Reserve Program. (a... year, adjust the base acres for covered commodities and peanuts with respect to the farm by the...

  20. Using the ACR/NEMA standard with TCP/IP and Ethernet

    NASA Astrophysics Data System (ADS)

    Chimiak, William J.; Williams, Rodney C.

    1991-07-01

    There is a need for a consolidated picture archival and communications system (PACS) in hospitals. At the Bowman Gray School of Medicine of Wake Forest University (BGSM), the authors are enhancing the ACR/NEMA Version 2 protocol using UNIX sockets and TCP/IP to greatly improve connectivity. Initially, nuclear medicine studies using gamma cameras are to be sent to PACS. The ACR/NEMA Version 2 protocol provides the functionality of the upper three layers of the open system interconnection (OSI) model in this implementation. The images, imaging equipment information, and patient information are then sent in ACR/NEMA format to a software socket. From there it is handed to the TCP/IP protocol, which provides the transport and network service. TCP/IP, in turn, uses the services of IEEE 802.3 (Ethernet) to complete the connectivity. The advantage of this implementation is threefold: (1) Only one I/O port is consumed by numerous nuclear medicine cameras, instead of a physical port for each camera. (2) Standard protocols are used which maximize interoperability with ACR/NEMA compliant PACSs. (3) The use of sockets allows a migration path to the transport and networking services of OSIs TP4 and connectionless network service as well as the high-performance protocol being considered by the American National Standards Institute (ANSI) and the International Standards Organization (ISO) -- the Xpress Transfer Protocol (XTP). The use of sockets also gives access to ANSI's Fiber Distributed Data Interface (FDDI) as well as other high-speed network standards.

  1. Island Natural Science School.

    ERIC Educational Resources Information Center

    Toronto Board of Education (Ontario).

    Prepared for students in grade six attending the Island Natural Science School, Toronto, Ontario, Canada, this booklet offers information and suggests activities in the areas of ecology, conservation, natural resources, and outdoor recreation. Introductory material describes island lore, its formation and significant features, followed by units of…

  2. Investigation of island formation due to RMPs in DIII-D plasmas with the SIESTA resistive MHD equilibrium code

    SciTech Connect

    Hirshman, S. P.; Shafer, M. W.; Seal, S. K.; Canik, J. M.

    2016-03-03

    The SIESTA magnetohydrodynamic (MHD) equilibrium code has been used to compute a sequence of ideally stable equilibria resulting from numerical variation of the helical resonant magnetic perturbation (RMP) applied to an axisymmetric DIII-D plasma equilibrium. Increasing the perturbation strength at the dominant $m=2$,$n=-1$ resonant surface leads to lower MHD energies and increases in the equilibrium island widths at the $m=2$ (and sidebands) surfaces, in agreement with theoretical expectations. Island overlap at large perturbation strengths leads to stochastic magnetic fields which correlate well with the experimentally inferred field structure. The magnitude and spatial phase (around the dominant rational surfaces) of the resonant (shielding) component of the parallel current are shown to change qualitatively with the magnetic island topology.

  3. Non-twist map bifurcation of drift-lines and drift-island formation in saturated 3D MHD equilibria

    NASA Astrophysics Data System (ADS)

    Pfefferle, David; Cooper, Wilfred A.; Graves, Jonathan P.

    2015-11-01

    Based on non-canonical perturbation theory, guiding-centre drift equations are identified as perturbed magnetic field-line equations. The topology of passing-particle orbits, called drift-lines, is completely determined by the magnetic configuration. In axisymmetric tokamak fields, drift-lines lie on shifted flux-surfaces, called drift-surfaces. Field-lines and drift-lines are subject to island structures at rational surfaces only when a non-axisymmetric component is added. The picture is different in the case of 3D saturated MHD equilibrium like the helical core associated with a non-resonant internal kink mode. In assuming nested flux-surfaces, these bifurcated states, expected for a reversed q-profile with qmin close yet above unity and conveniently obtained in VMEC, feature integrable field-lines. The helical drift-lines however become resonant with the axisymmetric component in the region of qmin and spontaneously generate drift-islands. Due to the locally reversed sheared q-profile, the drift-island structure follows the bifurcation/reconnection mechanism of non-twist maps. This result provides a theoretical interpretation of NBI fast ion helical hot-spots in Long-Lived Modes as well as snake-like impurity density accumulation in internal MHD activity.

  4. Comparison of Urine Albumin-to-Creatinine Ratio (ACR) Between ACR Strip Test and Quantitative Test in Prediabetes and Diabetes

    PubMed Central

    Cho, Seon; Kim, Suyoung; Cho, Han-Ik

    2017-01-01

    Background Albuminuria is generally known as a sensitive marker of renal and cardiovascular dysfunction. It can be used to help predict the occurrence of nephropathy and cardiovascular disorders in diabetes. Individuals with prediabetes have a tendency to develop macrovascular and microvascular pathology, resulting in an increased risk of retinopathy, cardiovascular diseases, and chronic renal diseases. We evaluated the clinical value of a strip test for measuring the urinary albumin-to-creatinine ratio (ACR) in prediabetes and diabetes. Methods Spot urine samples were obtained from 226 prediabetic and 275 diabetic subjects during regular health checkups. Urinary ACR was measured by using strip and laboratory quantitative tests. Results The positive rates of albuminuria measured by using the ACR strip test were 15.5% (microalbuminuria, 14.6%; macroalbuminuria, 0.9%) and 30.5% (microalbuminuria, 25.1%; macroalbuminuria, 5.5%) in prediabetes and diabetes, respectively. In the prediabetic population, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the ACR strip method were 92.0%, 94.0%, 65.7%, 99.0%, and 93.8%, respectively; the corresponding values in the diabetic population were 80.0%, 91.6%, 81.0%, 91.1%, and 88.0%, respectively. The median [interquartile range] ACR values in the strip tests for measurement ranges of <30, 30-300, and >300 mg/g were 9.4 [6.3-15.4], 46.9 [26.5-87.7], and 368.8 [296.2-575.2] mg/g, respectively, using the laboratory method. Conclusions The ACR strip test showed high sensitivity, specificity, and negative predictive value, suggesting that the test can be used to screen for albuminuria in cases of prediabetes and diabetes. PMID:27834062

  5. 24 CFR 1710.9 - Twenty acre lots.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Twenty acre lots. 1710.9 Section 1710.9 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND...

  6. ACR testing of a dedicated head SPECT unit.

    PubMed

    Sensakovic, William F; Hough, Matthew C; Kimbley, Elizabeth A

    2014-07-08

    Physics testing necessary for program accreditation is rigorously defined by the ACR. This testing is easily applied to most conventional SPECT systems based on gamma camera technology. The inSPira HD is a dedicated head SPECT system based on a rotating dual clamshell design that acquires data in a dual-spiral geometry. The unique geometry and configuration force alterations of the standard ACR physics testing protocol. Various tests, such as intrinsic planar uniformity and/or resolution, do not apply. The Data Spectrum Deluxe Phantom used for conventional SPECT testing cannot fit in the inSPira HD scanner bore, making (currently) unapproved use of the Small Deluxe SPECT Phantom necessary. Matrix size, collimator type, scanning time, reconstruction method, and attenuation correction were all varied from the typically prescribed ACR instructions. Visible spheres, sphere contrast, visible rod groups, uniformity, and root mean square (RMS) noise were measured. The acquired SPECT images surpassed the minimum ACR requirements for both spatial resolution (9.5 mm spheres resolved) and contrast (6.4 mm rod groups resolved). Sphere contrast was generally high. Integral uniformity was 4% and RMS noise was 1.7%. Noise appeared more correlated than in images from a conventional SPECT scanner. Attenuation-corrected images produced from direct CT scanning of the phantom and a manufacturer supplied model of the phantom demonstrated negligible differences.

  7. "Forty Acres and a Mule" as a Pedagogical Motif

    ERIC Educational Resources Information Center

    Burch, Kerry

    2008-01-01

    This essay revisits an iconic yet now languishing phrase in United States political culture--"Forty Acres and a Mule"--to clarify the meaning of freedom and to assess the contemporary meaning of its betrayal by the U.S. government immediately after the Civil War. Among the few citizens for whom the phrase still retains a semblance of…

  8. ACR Electrical Systems. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Clemons, Mark

    This document contains a teacher's guide and student guide for a high school-level competency-based course in air conditioning and refrigeration (ACR) equipment electrical systems. Presented in the teacher's guide are the following: explanation of the instructional units' use; competency profile for recording students' performance of the tasks in…

  9. AcrB, AcrD, and MdtABC multidrug efflux systems are involved in enterobactin export in Escherichia coli.

    PubMed

    Horiyama, Tsukasa; Nishino, Kunihiko

    2014-01-01

    Escherichia coli produces the iron-chelating compound enterobactin to enable growth under iron-limiting conditions. After biosynthesis, enterobactin is released from the cell. However, the enterobactin export system is not fully understood. Previous studies have suggested that the outer membrane channel TolC is involved in enterobactin export. There are several multidrug efflux transporters belonging to resistance-nodulation-cell division (RND) family that require interaction with TolC to function. Therefore, several RND transporters may be responsible for enterobactin export. In this study, we investigated whether RND transporters are involved in enterobactin export using deletion mutants of multidrug transporters in E. coli. Single deletions of acrB, acrD, mdtABC, acrEF, or mdtEF did not affect the ability of E. coli to excrete enterobactin, whereas deletion of tolC did affect enterobactin export. We found that multiple deletion of acrB, acrD, and mdtABC resulted in a significant decrease in enterobactin export and that plasmids carrying the acrAB, acrD, or mdtABC genes restored the decrease in enterobactin export exhibited by the ΔacrB acrD mdtABC mutant. These results indicate that AcrB, AcrD, and MdtABC are required for the secretion of enterobactin.

  10. Impacts of Dust on Tropical Volcanic Soil Formation: Insights from Strontium and Uranium-Series Isotopes in Soils from Basse-Terre Island, French Guadeloupe

    NASA Astrophysics Data System (ADS)

    Pereyra, Y.; Ma, L.; Sak, P. B.; Gaillardet, J.; Buss, H. L.; Brantley, S. L.

    2015-12-01

    Dust inputs play an important role in soil formation, especially for thick soils developed on tropical volcanic islands. In these regions, soils are highly depleted due to intensive chemical weathering, and mineral nutrients from dusts have been known to be important in sustaining soil fertility and productivity. Tropical volcanic soils are an ideal system to study the impacts of dust inputs on the ecosystem. Sr and U-series isotopes are excellent tracers to identify sources of materials in an open system if the end-members have distinctive isotope signatures. These two isotope systems are particularly useful to trace the origin of atmospheric inputs into soils and to determine rates and timescales of soil formation. This study analyzes major elemental concentrations, Sr and U-series isotope ratios in highly depleted soils in the tropical volcanic island of Basse-Terre in French Guadeloupe to determine atmospheric input sources and identify key soil formation processes. We focus on three soil profiles (8 to 12 m thick) from the Bras-David, Moustique Petit-Bourg, and Deshaies watersheds; and on the adjacent rivers to these sites. Results have shown a significant depletion of U, Sr, and major elements in the deep profile (12 to 4 m) attributed to rapid chemical weathering. The top soil profiles (4 m to the surface) all show addition of elements such as Ca, Mg, U, and Sr due to atmospheric dust. More importantly, the topsoil profiles have distinct Sr and U-series isotope compositions from the deep soils. Sr and U-series isotope ratios of the top soils and sequential extraction fractions confirm that the sources of the dust are from the Saharan dessert, through long distance transport from Africa to the Caribbean region across the Atlantic Ocean. During the transport, some dust isotope signatures may also have been modified by local volcanic ashes and marine aerosols. Our study highlights that dusts and marine aerosols play important roles in element cycles and

  11. ACR white paper: New practice models--hospital employment of radiologists: a report from the ACR Future Trends Committee.

    PubMed

    Medverd, Jonathan R; Muroff, Lawrence R; Brant-Zawadzki, Michael N; Lexa, Frank J; Levin, David C

    2012-11-01

    In response to the current era of rapid evolution of health care delivery and financing, radiologists are increasingly considering, as well as confronting, new practice models. Hospital employment is one such opportunity. Within this report to the ACR membership, the potential advantages and risks for radiologists considering hospital employment are examined.

  12. 78 FR 70597 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Planning and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ..., Rockville, Maryland. The meeting will be open to public attendance with the exception of a portion that may... that are open to the public. Detailed procedures for the conduct of and participation in ACRS meetings...-25-13; 8:45 am] BILLING CODE 7590-01-P...

  13. 76 FR 68793 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Planning and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... [Federal Register Volume 76, Number 215 (Monday, November 7, 2011)] [Notices] [Page 68793] [FR Doc... participation in ACRS meetings were published in the Federal Register on October 17, 2011 (76 FR 64127-64128... Assistant, Reactor Safety Branch, Advisory Committee on Reactor Safeguards. [FR Doc. 2011-28738 Filed...

  14. 78 FR 2694 - Meeting of the ACRS Subcommittee on Planning and Procedures; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Planning and... Reactor Safeguards. BILLING CODE 7590-01-P...

  15. A novel packing arrangement of AcrB in the lipid bilayer membrane.

    PubMed

    Ly, K; Bartho, J D; Eicher, T; Pos, K M; Mitra, A K

    2014-12-20

    The central component AcrB of the Escherichia coli drug efflux complex AcrA-AcrB-TolC has been extensively investigated by X-ray crystallography of detergent-protein 3-D crystals. In these crystals, AcrB packs as trimers - the functional unit. We visualized the AcrB-AcrB interaction in its native environment by examining E. coli lipid reconstituted 2-D crystals, which were overwhelmingly formed by asymmetric trimers stabilized by strongly-interacting monomers from adjacent trimers. Most interestingly, we observed lattices formed by an arrangement of AcrB monomers distinct from that in traditional trimers. This hitherto unobserved packing, might play a role in the biogenesis of trimeric AcrB.

  16. Identifying source and formation altitudes of nitrates in drinking water from Réunion Island, France, using a multi-isotopic approach.

    PubMed

    Rogers, Karyne M; Nicolini, Eric; Gauthier, Virginie

    2012-09-01

    Nitrate concentrations, water isotopes (δ(2)H and δ(18)O(water)) and associated nitrate isotopes (δ(15)N(nitrate) and δ(18)O(nitrate)) from 10 drinking water wells, 5 fresh water springs and the discharge from 3 wastewater treatment stations in Réunion Island, located in the Indian Ocean, were analysed. We used a multi isotopic approach to investigate the extent of nitrate contamination, nitrate formation altitude and source of nitrates in Réunion Island's principal aquifer. Water from these study sites contained between 0.1 and 85.3 mg/L nitrate. δ(15)N(nitrate) values between +6 and +14‰ suggested the main sources of contamination were animal and/or human waste, rather than inorganic (synthetic) fertilisers, infiltrating through the subsurface into the saturated zone, due to rainfall leaching of the unsaturated zone at various altitudes of precipitation. Based on δ(15)N(nitrate) values alone, it was not possible to distinguish between animal and human activities responsible for the contamination of each specific catchment. However, using a multi isotope approach (δ(18)O(water) and δ(15)N(nitrate)), it was possible to relate the average altitude of rainfall infiltration (δ(18)O(water)) associated with the nitrate contamination (δ(18)O(nitrate)). This relationship between land use, rainfall recharge altitude and isotopic composition (δ(15)N(nitrate) and δ(18)O(water)) discriminated between the influences of human waste at lower (below 600 m elevation) or animal derived contamination (at elevations between 600 and 1300 m). By further comparing the theoretical altitude of nitrate formation calculated by the δ(18)O(nitrate), it was possible to determine that only 5 out of 15 fresh water wells and springs followed the conservative nitrate formation mechanism of 2/3δ(18)O(water)+1/3δ(18)O(air), to give nitrate formation altitudes which corresponded to land use activities.

  17. The Acre vertebrate fauna: Age, diversity, and geography

    NASA Astrophysics Data System (ADS)

    Cozzuol, Mario Alberto

    2006-07-01

    The vertebrate faunal assemblage associated with the Neogene deposits in the Acre region (southwestern Amazonia) is secured as Late Miocene on the basis of a correlation with the 'Mesopotamian' faunal assemblage from the Paraná region of Argentina and Uruguay. Both assemblages occur in the time span of the Huayquerian South American Land Mammal Age (SALMA). The Acre, 'Mesopotamian' (Argentina and Uruguay), and Urumaco (Venezuela) assemblages are considered faunistically correlated and contemporaneous on the basis of their shared amniote taxa. The Laventan assemblage from Colombia has important faunistic affinities with the previous three but is older. A paleogeographic scenario is proposed to explain the long-distance correlation among those assemblages. On the basis of data from geology, field observations, fauna, and palynology, the validity of the Ucayali unconformity as a time marker along all of western Amazonia is rejected.

  18. ACR appropriateness criteria radiologic management of infected fluid collections.

    PubMed

    Lorenz, Jonathan M; Al-Refaie, Waddah B; Cash, Brooks D; Gaba, Ron C; Gervais, Debra A; Gipson, Matthew G; Kolbeck, Kenneth J; Kouri, Brian E; Marshalleck, Francis E; Nair, Ajit V; Ray, Charles E; Hohenwalter, Eric J

    2015-08-01

    The best management of infected fluid collections depends on a careful assessment of clinical and anatomic factors as well as an up-to-date review of the published literature, to be able to select from a host of multidisciplinary treatment options. This article reviews conservative, radiologic, endoscopic, and surgical options and their best application to infected fluid collections as determined by the ACR Appropriateness Criteria Expert Panel on Interventional Radiology. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals, and the application, by the panel, of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  19. Formation and Evolution of the San Cristobal Trough Transform Fault Linking the Southern Solomon Islands and Northern New Hebrides Trenches

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Hayes, G. P.; Herman, M. W.; Benz, H.

    2014-12-01

    The San Cristobal Trough, which occupies the southern segment of the South Solomon Trench, hosts a dominantly left-lateral transform plate boundary (SCTF) linking the southern end of the Solomon Islands subduction zone (SISZ) to the northern end of the New Hebrides (Vanuatu) subduction zone (NHSZ). At its western end (SISZ), the Australia plate is torn as a result of the transition from subduction to transform motion. The southern side of the tear translates approximately 375 km along the SCTF before subducting beneath the Santa Cruz Islands at the NHSZ. Earthquakes occurring along this transform reflect the processes of plate tearing, fault zone evolution, and subsequent underthrusting and subduction of the Australia-plate-side of the transform. A knot of earthquake activity at the western end of the SCTF juxtaposes high-angle thrust faulting events with left-lateral strike slip events. These record the tearing of Australian lithosphere, as shown by a recent pair of large earthquakes in that region - a Mw 7.6 strike-slip event (12 April 2014) followed 22 hours later by a Mw 7.4 high-angle reverse faulting event (13 April 2014). Associated displacements reflect oblique tearing (northern-side down and west), allowing the Australia Plate to follow two disparate paths - subduction at the SISZ to the north and translation along the SCTF to the south. Moving eastward along the transform, the plate boundary shows three styles of earthquake activity. The main transform is dominated by shallow, E-W striking, left-lateral faulting and E-W striking thrust faults (with a north-dipping shallow fault plane) - these reflect partitioning of oblique motion along the transform between the Australia and Pacific plates. Outboard (+/- 100 km) of the plate boundary, a group of E-W striking shallow normal faulting events reflect upward bending driven by the convergent component of plate motions. Approaching the NHSZ, normal faulting earthquakes in the Australia Plate rotate clockwise

  20. 7 CFR 1412.79 - Executed ACRE contract not in conformity with regulations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Executed ACRE contract not in conformity with... Average Crop Revenue Election (ACRE) Program § 1412.79 Executed ACRE contract not in conformity with... conformity with the provisions of this part, the provisions of this part will prevail....

  1. 75 FR 4882 - Meeting of the ACRS Subcommittee on EPR; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... COMMISSION Advisory Committee On Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on EPR; Notice of Meeting The ACRS U.S. Evolutionary Power Reactor (EPR) Subcommittee will hold a meeting on February 18-19... inconvenience. Dated: January 25, 2010. Antonio F. Dias, Chief, Reactor Safety Branch B, Advisory Committee...

  2. 10 CFR 52.87 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.87 Section 52.87 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the ACRS. The...

  3. 78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels will hold a meeting...

  4. 10 CFR 52.87 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.87 Section 52.87 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the ACRS. The...

  5. 76 FR 57082 - Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ... COMMISSION Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels Revision to September 21, 2011, ACRS Meeting; Federal Register Notice The Federal Register Notice for the ACRS Subcommittee Meeting on Materials, Metallurgy and Reactor Fuels is...

  6. 76 FR 76442 - Advisory Committee On Reactor Safeguards Meeting of The ACRS Subcommittee on Materials...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... COMMISSION Advisory Committee On Reactor Safeguards Meeting of The ACRS Subcommittee on Materials, Metallurgy & Reactor Fuels Revision to December 15, 2011, ACRS Meeting Federal Register Notice The Federal Register Notice for the ACRS Subcommittee Meeting on Materials, Metallurgy & Reactor Fuels scheduled to be held...

  7. 7 CFR 1412.79 - Executed ACRE contract not in conformity with regulations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Executed ACRE contract not in conformity with... Average Crop Revenue Election (ACRE) Program § 1412.79 Executed ACRE contract not in conformity with... conformity with the provisions of this part, the provisions of this part will prevail....

  8. 76 FR 9835 - Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... COMMISSION Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Digital Instrumentation & Control (DI&C); Revision to February 23, 2011, ACRS Meeting Federal Register Notice The Federal Register Notice for the ACRS Subcommittee Meeting on Digital Instrumentation & Control (DI&C) scheduled...

  9. Formation of composite pyroclasts by welding inside a lithic-rich mafic eruption column (Los Marteles Caldera, Canary Islands)

    NASA Astrophysics Data System (ADS)

    Sarrionandia, F.; Carracedo Sánchez, M.; Arostegui, J.; Gil Ibarguchi, J. I.

    2015-12-01

    The tuff ring of the Los Marteles phreatomagmatic maar (Gran Canaria, Canary Islands) includes a particular unit that comprises abundant composite spheroidal clasts. However, these clasts differ from cored clasts elsewhere that consist of erupted lithic pyroclasts with an adhering rim of coherent chilled magma. The composite clasts here studied range from lapilli to bombs, and are cored or concentrically banded. Among the welded components, several types of primary clasts are discerned that include: (i) juvenile clasts, resultant of the magma inertial fragmentation, and (ii) cognate or accessory lithic clasts. Juvenile clasts include glass spheres (nano- and microachneliths) and crystals. Lithic clasts include lava fragments, scoriae and olivine xenocrysts. Primary clasts are interpreted to have been produced by the explosion of a partially crystallized mafic (SiO2 ≈ 50-55%) magma that erupted into a maar, filled-up with scoriae plus lava fragments. The explosion would have originated as a dense and turbulent gas thrust into which the repeated collisions of melt droplets with solid clasts generated droplet-coated crystals, lithic clasts and single glass spheres. We interpret the cored and concentrically banded pyroclasts to be made of coalesced and/or agglutinated particles coated with a melt rim to the rest of the components. These composite clasts developed spheroidal shapes during transport within a violent Strombolian eruption column due to spin effect and, finally, landed in solid state.

  10. Trace fossils and sedimentology of a Late Cretaceous Progradational Barrier Island sequence: Bearpaw and Horseshoe Canyon Formations, Dorothy, Alberta

    SciTech Connect

    Saunders, T.D.; Pemberton, A.G.; Ranger, M.J. )

    1990-05-01

    A well-exposed example of a regressive barrier island succession crops out in the Alberta badlands along the Red Deer River Valley. In the most landward (northwestern) corner of the study area, only shallow-water and subaerial deposits are represented and are dominated by tidal inlet related facies. Seaward (southeast), water depth increases and the succession is typified by open-marine beach to offshore-related facies arranged in coarsening-upward progradational sequence. Detailed sedimentologic and ichnologic analyses of this sequence have allowed for its division into three distinct environmental zones (lower, middle, and upper). The lower zone comprises a laterally diverse assemblage of storm-influenced, lower shoreface through offshore deposits. Outcrop in the northeast is dominated by thick beds of hummocky and/or swaley cross-stratified storm sand. In the southeast, storm events have only minor influence. This lower zone contains a wide diversity of well-preserved trace fossils whose distribution appears to have been influenced by gradients in wave energy, bottom stagnation, and the interplay of storm and fair-weather processes. The middle zone records deposition across an upper shoreface environment. Here, horizontal to low-angle bedding predominates, with interspersed sets of small- and large-scale cross-bedding increasing toward the top. A characteristic feature of the upper part of this zone is the lack of biogenic structures suggesting deposition in an exposed high-energy surf zone. The upper zone records intertidal to supratidal progradation of the shoreline complex. Planar-laminated sandstone forms a distinct foreshore interval above which rhizoliths and organic material become increasingly abundant, marking transition to the backshore. A significant feature of this zone is the occurrence of an intensely bioturbated interval toward the top of the foreshore.

  11. High resolution carbon isotope stratigraphy and glendonite occurrences of the Christopher Formation, Sverdrup Basin (Axel Heiberg Island, Canada): implications for mid Cretaceous high latitude climate change

    NASA Astrophysics Data System (ADS)

    Herrle, Jens O.; Schröder-Adams, Claudia J.; Galloway, Jennifer M.; Pugh, Adam T.

    2013-04-01

    Understanding the evolution of Canada's Arctic region, as a crucial component of Earth's climate system, is fundamental to assess short and long-term climate, environmental, and paleogeographic change. However, the stratigraphy and paleoenvironmental evolution of the Cretaceous Arctic is poorly constrained and a detailed bio- and chemostratigraphic correlation of major mid-Cretaceous paleoceanographic turning points such as Oceanic Anoxic Events, cold snaps, and biotic turnovers with key locations of the high- and low latitudes is missing. Here we present for the first time a high resolution bio- and carbon isotope stratigraphy of the Arctic Albian Christopher Formation of the Sverdrup Basin at Glacier Fiord in the southern part of Axel Heiberg Island, Canadian High Arctic. By using these techniques we developed a high temporal framework to record major environmental changes as it is indicated by the occurrence of glendonites and sandstone intervals of our studied Albian succession. The Albian Christopher Formation is a shale dominated marine unit with a thickness of approximately 1200 m. Several transgressive/ regressive cycles can be recognized by prograding shoreface units that break up mudrock deposition. In addition, glendonites are mainly found in the lower part of the Christopher Formation. Glendonites are pseudomorphs of calcite, after the metastable mineral ikaite, and have been often described from high latitude Permian, Jurassic and Cretaceous marine environments from the Canadian Arctic, Spitsbergen and Australia. The formation of glendonites takes place in the uppermost layer of the sediment and requires near-freezing temperatures, high salinity, and orthophosphate-rich bottom water. Although the presence of glendonites implies a range of paleoenvironmental conditions there is a consensus in the scientific literature that they reflect cooler paleoenvironmental conditions. Preliminary bio- and carbon isotope stratigraphic results suggest that the

  12. Overexpression and purification of the three components of the Enterobacter aerogenes AcrA-AcrB-TolC multidrug efflux pump.

    PubMed

    Masi, Muriel; Pagès, Jean-Marie; Pradel, Elizabeth

    2003-03-25

    The tripartite AcrA-AcrB-TolC system is the major efflux pump of the nosocomial pathogen Enterobacter aerogenes. AcrA is a trimeric periplasmic lipoprotein anchored in the inner membrane, AcrB is an inner membrane transporter and TolC is a trimeric outer membrane channel. In order to reconstitute the AcrA-AcrB-TolC system of E. aerogenes in artificial membranes, we overexpressed and purified the three proteins. The E. aerogenes acrA, acrB and tolC open reading frames were individually inserted in the expression vector pET24a(+), in frame with a sequence coding a C-terminal hexahistidine tag to allow purification by INAC (Immobilized Nickel Affinity Chromatography). The mature AcrA-6His was overproduced in a soluble form in the cytoplasm of Escherichia coli BL21(DE3). AcrA-6His was purified under native conditions in two steps using INAC and gel permeation chromatography. We obtained about 25 mg of 97% pure AcrA-6His per liter of culture. AcrB-6His was solubilized from the membrane fraction of E. coli C43(DE3) in 300 mM NaCl, 5% Triton X-100 and purified in one step by INAC. The AcrB-6His enriched fraction was eluted with 100 mM imidazole. The final yield was 1-2 mg of 95% pure AcrB-6His per liter of culture. The membrane fraction of E. coli BL21(DE3)pLysS containing TolC-6His was first treated with 2% Triton X-100, 30 mM MgCl(2) to solubilize the inner membrane proteins. After ultracentrifugation, the pellet was treated with 5% Triton X-100, 5 mM EDTA to solubilize the outer membrane proteins. Approximately 5 mg of 95% pure TolC-6His trimers per liter of culture was purified by INAC.

  13. Pyroclastic flows and lavas of the Mogan and Fataga formations, Tejeda Volcano, Gran Canaria, Canary Islands: mineral chemistry, intensive parameters, and magma chamber evolution

    NASA Astrophysics Data System (ADS)

    Crisp, Joy A.; Spera, Frank J.

    1987-12-01

    The Mogan and Fataga formations on the island of Gran Canaria, Canary Islands, represent a sequence of approximately 30 intercalated pyroclastic and lava flows (total volume about 500 km3 dense-rock equivalent) including subalkaline rhyolitic, peralkaline rhyolitic and trachytic pyroclastic flows, nepheline trachyte lavas and a small volume of alkali basaltic lavas and tephra deposits. The eruption of the intermediate to silicic rocks of the Mogan and Fataga formations follows the roughly 4 Ma duration of basaltic shield volcanism. The most common assemblage in the evolved (Mogan and Fataga) rocks is anorthoclase+ edenitic amphibole+ilmenite+magnetite±augite±hypersthene +apatite+pyrrhotite. A few flows also contain plagioclase, biotite, or sphene. Coexisting Fe-Ti oxides yield equilibrium temperatures between 835 and 930° C and logf_{O_2 } between -11.2 and -12.6. The lowermost pyroclastic flow of the Mogan formation is zoned from a rhyolitic base (848° C) to a basaltic top (931° C). Unit P1 has an oxygen isotope feldspar-magnetite temperature (850° C) very close to its Fe-Ti oxide temperature. One of the youngest Mogan flows is zoned from a comendite (836° C) at the base to a comenditic trachyte (899° C) at the top. The Fataga formation pyroclastic flows show only slight compositional zonation, and one flow has the same Fe-Ti oxide compositions at top and base. Calculations using the reaction 1/3 magnetite+SiO2 (melt)=ferrosilite+1/6 O2 indicate total pressures of 1 4 (±3) kb for six of the Mogan flows and one of the Fataga flows. For four of the pyroclastic flows, equilibria involving tremolite-SiO2-diopside-enstatite-H2O and phlogopite-SiO2-sanidine-enstatite-H2O imply water contents of 0.9 to 2.6 (±0.5) wt% andf_{H_2 O} between 80 and 610 bars, which indicates that magma within the Tejeda reservoir was H2O-undersaturated throughout the entire history of Mogan to Fataga volcanism. The fluorine contents of amphibole, biotite, and apatite, and chlorine

  14. ACR Appropriateness Criteria Clinically Suspected Pulmonary Arteriovenous Malformation.

    PubMed

    Hanley, Michael; Ahmed, Osmanuddin; Chandra, Ankur; Gage, Kenneth L; Gerhard-Herman, Marie D; Ginsburg, Michael; Gornik, Heather L; Johnson, Pamela T; Oliva, Isabel B; Ptak, Thomas; Steigner, Michael L; Strax, Richard; Rybicki, Frank J; Dill, Karin E

    2016-07-01

    Pulmonary arteriovenous malformations are often included in the differential diagnosis of common clinical presentations, including hypoxemia, hemoptysis, brain abscesses, and paradoxical stroke, as well as affecting 30% to 50% of patients with hereditary hemorrhagic telangiectasia (HHT). Various imaging studies are used in the diagnostic and screening settings, which have been reviewed by the ACR Appropriateness Criteria Vascular Imaging Panel. Pulmonary arteriovenous malformation screening in patients with HHT is commonly performed with transthoracic echocardiographic bubble study, followed by CT for positive cases. Although transthoracic echocardiographic bubble studies and radionuclide perfusion detect right-to-left shunts, they do not provide all of the information needed for treatment planning and may remain positive after embolization. Pulmonary angiography is appropriate for preintervention planning but not as an initial test. MR angiography has a potential role in younger patients with HHT who may require lifelong surveillance, despite lower spatial resolution compared with CT. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  15. Substrate-dependent dynamics of the multidrug efflux transporter AcrB of Escherichia coli.

    PubMed

    Yamamoto, Kentaro; Tamai, Rei; Yamazaki, Megumi; Inaba, Takehiko; Sowa, Yoshiyuki; Kawagishi, Ikuro

    2016-02-26

    The resistance-nodulation-cell division (RND)-type xenobiotic efflux system plays a major role in the multidrug resistance of gram-negative bacteria. The only constitutively expressed RND system of Escherichia coli consists of the inner membrane transporter AcrB, the membrane fusion protein AcrA, and the outer membrane channel TolC. The latter two components are shared with another RND-type transporter AcrD, whose expression is induced by environmental stimuli. Here, we demonstrate how RND-type ternary complexes, which span two membranes and the cell wall, form in vivo. Total internal reflection fluorescence (TIRF) microscopy revealed that most fluorescent foci formed by AcrB fused to green fluorescent protein (GFP) were stationary in the presence of TolC but showed lateral displacements when tolC was deleted. The fraction of stationary AcrB-GFP foci decreased with increasing levels of AcrD. We propose that the AcrB-containing complex becomes unstable upon the induction of AcrD, which presumably replaces AcrB, a process we call "transporter exchange." This instability is suppressed by AcrB-specific substrates, suggesting that the ternary complex is stabilised when it is in action. These results suggest that the assembly of the RND-type efflux system is dynamically regulated in response to external stimuli, shedding new light on the adaptive antibiotic resistance of bacteria.

  16. Formation of cordierite-bearing lavas during anatexis in the lower crust beneath Lipari Island (Aeolian arc, Italy)

    USGS Publications Warehouse

    Di, Martino C.; Forni, F.; Frezzotti, M.L.; Palmeri, R.; Webster, J.D.; Ayuso, R.A.; Lucchi, F.; Tranne, C.A.

    2011-01-01

    Cordierite-bearing lavas (CBL;~105 ka) erupted from the Mt. S. Angelo volcano at Lipari (Aeolian arc, Italy) are high-K andesites, displaying a range in the geochemical and isotopic compositions that reflect heterogeneity in the source and/or processes. CBL consist of megacrysts of Ca-plagioclase and clinopyroxene, euhedral crystals of cordierite and garnet, microphenocrysts of orthopyroxene and plagioclase, set in a heterogeneous rhyodacitic-rhyolitic groundmass containing abundant metamorphic and gabbroic xenoliths. New petrographic, chemical and isotopic data indicate formation of CBL by mixing of basaltic-andesitic magmas and high-K peraluminous rhyolitic magmas of anatectic origin and characterize partial melting processes in the lower continental crust of Lipari. Crustal anatectic melts generated through two main dehydration-melting peritectic reactions of metasedimentary rocks: (1) Biotite + Aluminosilicate + Quartz + Albite = Garnet + Cordierite + K-feldspar + Melt; (2) Biotite + Garnet + Quartz = Orthopyroxene + Cordierite + K-feldspar + Melt. Their position into the petrogenetic grid suggests that heating and consequent melting of metasedimentary rocks occurred at temperatures of 725 < T < 900??C and pressures of 0.4-0.45 GPa. Anatexis in the lower crust of Lipari was induced by protracted emplacement of basic magmas in the lower crust (~130 Ky). Crustal melting of the lower crust at 105 ka affected the volcano evolution, impeding frequent maficmagma eruptions, and promoting magma stagnation and fractional crystallization processes. ?? 2011 Springer-Verlag.

  17. Crystallization and preliminary crystallographic characterization of LmACR2, an arsenate/antimonate reductase from Leishmania major

    SciTech Connect

    Bisacchi, Davide; Zhou, Yao; Rosen, Barry P.; Mukhopadhyay, Rita; Bordo, Domenico

    2006-10-01

    LmACR2 from L. major is the first rhodanese-like enzyme directly involved in the reduction of arsenate and antimonate to be crystallized. Diffraction data have been collected to 1.99 Å resolution using synchrotron X-rays. Arsenic is present in the biosphere owing either to the presence of pesticides and herbicides used in agricultural and industrial activities or to leaching from geological formations. The health effects of prolonged exposure to arsenic can be devastating and may lead to various forms of cancer. Antimony(V), which is chemically very similar to arsenic, is used instead in the treatment of leishmaniasis, an infection caused by the protozoan parasite Leishmania sp.; the reduction of pentavalent antimony contained in the drug Pentostam to the active trivalent form arises from the presence in the Leishmania genome of a gene, LmACR2, coding for the protein LmACR2 (14.5 kDa, 127 amino acids) that displays weak but significant sequence similarity to the catalytic domain of Cdc25 phosphatase and to rhodanese enzymes. For structural characterization, LmACR2 was overexpressed, purified to homogeneity and crystallized in a trigonal space group (P321 or P3{sub 1}21/P3{sub 2}21). The protein crystallized in two distinct trigonal crystal forms, with unit-cell parameters a = b = 111.0, c = 86.1 Å and a = b = 111.0, c = 175.6 Å, respectively. At a synchrotron beamline, the diffraction pattern extended to a resolution limit of 1.99 Å.

  18. A model of tephra dispersal from an early Palaeogene shallow submarine Surtseyan-style eruption(s), the Red Bluff Tuff Formation, Chatham Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Sorrentino, Leonor; Stilwell, Jeffrey D.; Mays, Chris

    2014-03-01

    The Red Bluff Tuff Formation, an early Palaeogene volcano-sedimentary shallow marine succession from the Chatham Islands (New Zealand), provides a unique framework, in eastern 'Zealandia', to explore tephra dispersal processes associated with ancient small phreatomagmatic explosions (i.e. Surtseyan-style eruptions). Detailed sedimentological mapping, logging and sampling integrated with the results of extensive laboratory analyses (i.e. grain-size, componentry and applied palaeontological methods) elucidated the complex mechanisms of transport and deposition of nine identified resedimented fossiliferous volcaniclastic facies. These facies record the subaqueous reworking and deposition of tephra from the erosion and degradation of a proximal, entirely submerged ancient Surtseyan volcanic edifice (Cone II). South of this volcanic cone, the lowermost distal facies provides significant evidence of deposition as water-supported volcanic- or storm-driven mass flows (e.g. turbidity currents and mud/debris flows) of volcaniclastic and bioclastic debris, whereas the uppermost distal facies exhibit features of tractional sedimentary processes caused by shallow subaqueous currents. Further north, within the proximity of the volcanic edifice, the uppermost facies are represented by an abundant, diverse, large, and well preserved in situ fauna of shallow marine sessile invertebrates (e.g. corals and sponges) that reflect the protracted biotic stabiliszation and rebound following pulsed volcanic events. Over a period of time, these stable and wave-eroded volcanic platforms were inhabited by a flourishing and diversifying marine community of benthic and sessile pioneers (corals, bryozoans, molluscs, brachiopods, barnacles, sponges, foraminifera, etc.). This succession exhibits a vertical progression of sedimentary structures (i.e. density, cohesive and mass flows, and cross-bedding) and our interpretations indicate a shallowing upwards succession. This study reports for the first

  19. MO-AB-207-00: ACR Update in MR, CT, Nuclear Medicine, and Mammography

    SciTech Connect

    2015-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, computed tomography, nuclear medicine, and mammography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR Accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process. To understand the requirements of the ACR nuclear medicine accreditation program, and the role of the physicist in annual equipment surveys and the set up and supervision of the routine QC program. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program.

  20. TU-A-18C-01: ACR Accreditation Updates in CT, Ultrasound, Mammography and MRI

    SciTech Connect

    Price, R; Berns, E; Hangiandreou, N; McNitt-Gray, M

    2014-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, the ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, mammography, ultrasound, and computed tomography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program. To understand the new requirements of the ACR ultrasound accreditation program, and roles the physicist can play in annual equipment surveys and setting up and supervising the routine QC program. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process.

  1. MO-AB-207-03: ACR Update in Nuclear Medicine

    SciTech Connect

    Harkness, B.

    2015-06-15

    A goal of an imaging accreditation program is to ensure adequate image quality, verify appropriate staff qualifications, and to assure patient and personnel safety. Currently, more than 35,000 facilities in 10 modalities have been accredited by the American College of Radiology (ACR), making the ACR program one of the most prolific accreditation options in the U.S. In addition, ACR is one of the accepted accreditations required by some state laws, CMS/MIPPA insurance and others. Familiarity with the ACR accreditation process is therefore essential to clinical diagnostic medical physicists. Maintaining sufficient knowledge of the ACR program must include keeping up-to-date as the various modality requirements are refined to better serve the goals of the program and to accommodate newer technologies and practices. This session consists of presentations from authorities in four ACR accreditation modality programs, including magnetic resonance imaging, computed tomography, nuclear medicine, and mammography. Each speaker will discuss the general components of the modality program and address any recent changes to the requirements. Learning Objectives: To understand the requirements of the ACR MR Accreditation program. The discussion will include accreditation of whole-body general purpose magnets, dedicated extremity systems well as breast MRI accreditation. Anticipated updates to the ACR MRI Quality Control Manual will also be reviewed. To understand the requirements of the ACR CT accreditation program, including updates to the QC manual as well as updates through the FAQ process. To understand the requirements of the ACR nuclear medicine accreditation program, and the role of the physicist in annual equipment surveys and the set up and supervision of the routine QC program. To understand the current ACR MAP Accreditation requirement and present the concepts and structure of the forthcoming ACR Digital Mammography QC Manual and Program.

  2. A reconnaissance of hydrogeologic conditions in Lehigh Acres and adjacent areas of Lee County, Florida

    USGS Publications Warehouse

    Boggess, Durward Hoye; Missimer, T.M.

    1975-01-01

    Lehigh Acres, a residential community with a population of about 13,500 and comprising an area of about 94 square miles (243 square kilometres) in the eastern part of Lee County, has been under development since 1954. Prior to development the area was poorly drained. By 1974, more than 150 miles (241 kilometres) of drainageways had been constructed to drain the area. The water-bearing formations underlying Lehigh Acres include the water-table, sandstone, lower Hawthorn, and Suwannee aquifers. The water-table aquifer is usually not more than 30 feet (9 metres) thick; it contains water of relatively good quality, except for iron and color. Water levels in this aquifer probably have been affected by construction of drainage canals. The sandstone aquifer, used extensively throughout the area as a source of water supply usually contains water of good quality although the water is hard and in places may contain concentrations of dissolved solids and iron which exceed the recommended limits of the U.S. Public Health Service and the State of Florida for drinking water. The lower Hawthorn and Suwannee aquifers, usually encountered at depths between 440 and 850 feet (135 and 262 metres), contains water with relatively high concentrations of sodium, sulfate, chloride, and dissolved solids. Three streams, the Orange River, Hickey Creek, and Bedman Creek and the canals connected to them, provide drainage of the area. Except for the Orange River, where the water is of good chemical quality, little is known of the water quality. Similarly, little information is available on stream discharge except for the Orange River where the average annual discharge was 41.1 cubic feet per second (11.6 cubic metres per second) between 1935-46. Most lakes and ponds in Lehigh Acres are hydraulically connected to the water-table aquifer such that factors which affect one also affect the other. Theoretical drawdown curves indicate that the drainage canals may affect ground-water levels to a

  3. Galapagos Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  4. [Difference and its formation cause in soil organic carbon accumulation capability of two typical tidal wetlands at Dongtan of Chongming Island in Shanghai].

    PubMed

    Li, Yan-Li; Xiao, Chun-Ling; Wang, Lei; Zhang, Wen-Quan; Zhang, Shi-Ping; Wang, Hong-Li; Fu, Xiao-Hua; Le, Yi-Quan

    2009-06-01

    Through the analyses of soil organic carbon content and vegetation input, this paper studied the difference in soil organic carbon accumulation capability of two typical tidal wetlands, one (A) was on the erosion bank with Phragmites communis and sandy loam soil at southeast Dongtan in Shanghai, and the other (B) was on the alluvial bank with P. communis, Spartina alterniflora, and clay soil at northeast Dongtan of Chongming Island. The main formation causes of the difference were analyzed based on the determinations of soil microbial activities and physical-chemical properties. In A, the average soil total organic carbon content was 46.10% (P < 0.05) of that in B, while the annual aboveground vegetation dry mass was only 9.16% lower than that in B, illustrating that the soil organic carbon output was higher in A than in B. The total count of soil bacteria and the activities of soil catalase and invertase in A were 3.82 times (P < 0.05), 46.81% (P < 0.05), and 34.33% (P < 0.05) higher than those in B, respectively, and the soil microbial respiration in A was also higher than that in B, which indicated that the stronger soil microbial C-metabolic activity in A was the main cause inducing the lower soil organic carbon accumulation capability. The sandy loam soil in A had higher porosity and lower salinity and moisture, being favorable to the growth of soil microbes and the decomposition of soil organic carbon, while the clay soil in B had higher salinity and moisture but lower microbial activity, leading to the weaker soil organic carbon decomposition and higher organic carbon accumulation.

  5. Akpatok Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

  6. Drainage-return, surface-water withdrawal, and land-use data for the Sacramento-San Joaquin Delta, with emphasis on Twitchell Island, California

    USGS Publications Warehouse

    Templin, William E.; Cherry, Daniel E.

    1997-01-01

    Partial data on drainage returns and surface-water withdrawals are presented for areas of the Sacramento-San Joaquin Delta, California, for March 1994 through February 1996. These areas cover most of the delta. Data are also presented for all drainage returns and some surface-water withdrawals for Twitchell Island, which is in the western part of the delta. Changes in land use between 1968 and 1991 are also presented for the delta. Measurements of monthly drainage returns and surface-water withdrawals were made using flowmeters installed in siphons and drain pipes on Twitchell Island. Estimates of monthly returns throughout the delta were made using electric power-consumption data with pump-efficiency-test data. For Twitchell Island, monthly measured drainage returns for the 1995 calendar year totaled about 11,200 acre-feet, whereas drainage returns estimated from power-consumption data totaled 5 percent less at about 10,600 acre-feet. Monthly surface-water withdrawals onto Twitchell Island through 12 of the 21 siphons totaled about 2,400 acre-feet for 1995. For most of the delta, the monthly estimated drainage returns for 1995 totaled about 430,000 acre-feet. The area consisting of Bouldin, Brannan, Staten, Tyler, and Venice Islands had the largest estimated drainage returns for calendar year 1995. Between 1968 and 1991, native vegetation in the delta decreased by 25 percent (about 40,000 acres), and grain and hay crops increased by 340 percent (about 71,000 acres). For Twitchell Island, native vegetation decreased about 77 percent (about 850 acres), while field crop acreage increased by about 44 percent (about 780 acres).

  7. 10 CFR 52.53 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.53 Section 52.53 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  8. 10 CFR 52.165 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.165 Section 52.165 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  9. 10 CFR 52.165 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.165 Section 52.165 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  10. 75 FR 10840 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Advanced Boiling...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Advanced Boiling Water Reactor (ABWR); Notice of Meeting The ACRS Subcommittee on ABWR will hold a meeting on March 18... 3, 2010. Antonio F. Dias, Chief, Reactor Safety Branch B, Advisory Committee on Reactor...

  11. 75 FR 7632 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Advanced Boiling...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-22

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Advanced Boiling Water Reactor (ABWR) The ACRS Subcommittee on ABWR will hold a meeting on March 2, 2010, at 11545...: February 12, 2010. Antonio F. Dias, Chief Reactor Safety Branch B, Advisory Committee on Reactor...

  12. 10 CFR 52.23 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.23 Section 52.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application for an early...

  13. 10 CFR 52.23 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.23 Section 52.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application for an early...

  14. 10 CFR 52.141 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.141 Section 52.141 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  15. 10 CFR 52.141 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.141 Section 52.141 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  16. 75 FR 13611 - Meeting of the ACRS Subcommittee on Reliability and PRA; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-22

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Reliability... would result in major inconvenience. Dated: March 15, 2010. Antonio F. Dias, Chief, Reactor Safety Branch B, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  17. 10 CFR 52.53 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.53 Section 52.53 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS... Committee on Reactor Safeguards (ACRS). The Commission shall refer a copy of the application to the...

  18. 75 FR 47621 - Final Environmental Impact Statement for the North Fork Rancheria's Proposed 305-Acre Trust...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ...-Acre Trust Acquisition and Hotel/Casino Project, Madera County, CA AGENCY: Bureau of Indian Affairs... develop a hotel, casino, parking facilities, and supporting infrastructure. The proposed 305-acre site... Proposed Project includes the development of an approximately 472,000 square foot hotel and casino...

  19. 75 FR 38564 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Plant Operations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Plant Operations and Fire Protection The ACRS Subcommittee on Plant Operations and Fire Protection will hold a...

  20. 76 FR 80410 - Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Radiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... Doc No: 2011-32907] NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Radiation Protection and Nuclear Materials; Notice of Meeting The ACRS Subcommittee on Radiation Protection and Nuclear Materials will hold a meeting on January 18, 2012, Room...

  1. Effectiveness of urban stormwater control measures in a 100-acre test site

    EPA Science Inventory

    Kansas City, Missouri chose a test area (100 acres) and a control area (80 acres) to test the effectiveness of urban stormwater control (SCM) deployment in conjunction with the USEPA, University of Alabama, University of Missouri-Kansas City and TetraTech. Both the test and cont...

  2. Proliferation Resistance Evaluation of ACR-1000 Fuel with Minor Actinides

    SciTech Connect

    Gray S. Chang

    2008-09-01

    The Global Nuclear Energy Partnership (GNEP) program is to significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs can play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In this work, an Advanced CANDU Reactor (ACR) fuel unit lattice cell model with 43 UO2 fuel rods will be used to investigate the effectiveness of a Minor Actinide Reduction Approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance. The main MARA objective is to increase the 238Pu / Pu isotope ratio by using the transuranic nuclides (237Np and 241Am) in the high burnup fuel and thereby increase the proliferation resistance even for a very low fuel burnup. As a result, MARA is a very effective approach to enhance the proliferation resistance for the on power refueling ACR system nuclear fuel. The MA transmutation characteristics at different MA loadings were compared and their impact on neutronics

  3. ACR11 is an Activator of Plastid-Type Glutamine Synthetase GS2 in Arabidopsis thaliana.

    PubMed

    Osanai, Takashi; Kuwahara, Ayuko; Otsuki, Hitomi; Saito, Kazuki; Yokota Hirai, Masami

    2017-03-06

    Glutamine synthetase (GS) is an important enzyme for nitrogen assimilation, and GS2, encoded by GLN2, is the only plastid-type GS in Arabidopsis thaliana. A co-expression analysis suggested that the expression level of the gene encoding a uridylyltransferase-like protein, ACR11, is strongly correlated with GLN2 expression levels. Here we showed that the recombinant ACR11 protein increased GS2 activity in vitro by reducing the Km values of its substrate glutamine. A T-DNA insertion mutant of ACR11 exhibited a reduced GS activity under low nitrate conditions and reduced glutamine levels. Biochemical analyses revealed that ACR11 and GS2 interacted both in vitro and in vivo. These data demonstrate that ACR11 is an activator of GS2, giving it a mechanistic role in the nitrogen assimilation of A. thaliana.

  4. Crystal structure of AcrB in complex with a single transmembrane subunit reveals another twist.

    PubMed

    Törnroth-Horsefield, Susanna; Gourdon, Pontus; Horsefield, Rob; Brive, Lars; Yamamoto, Natsuko; Mori, Hirotada; Snijder, Arjan; Neutze, Richard

    2007-12-01

    Bacterial drug resistance is a serious concern for human health. Multidrug efflux pumps export a broad variety of substrates out of the cell and thereby convey resistance to the host. In Escherichia coli, the AcrB:AcrA:TolC efflux complex forms a principal transporter for which structures of the individual component proteins have been determined in isolation. Here, we present the X-ray structure of AcrB in complex with a single transmembrane protein, assigned by mass spectrometry as YajC. A specific rotation of the periplasmic porter domain of AcrB is also revealed, consistent with the hypothesized "twist-to-open" mechanism for TolC activation. Growth experiments with yajc-deleted E. coli reveal a modest increase in the organism's susceptibility to beta-lactam antibiotics, but this effect could not conclusively be attributed to the loss of interactions between YajC and AcrB.

  5. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  6. Size Distributions and Formation Pathways of Organic and Inorganic Constituents in Spring Aerosols from Okinawa Island in the Western North Pacific Rim: An Outflow Region of Asian Dusts

    NASA Astrophysics Data System (ADS)

    Deshmukh, D. K.; Lazaar, M.; Kawamura, K.; Kunwar, B.; Tachibana, E.; Boreddy, S. K. R.

    2015-12-01

    Size-segregated aerosols (9-stages) were collected at Okinawa Island in the western North Pacific Rim in spring 2008. The samples were analyzed for diacids (C2-C12), ω-oxoacids (ωC2-ωC9), a-dicarbonyls (C2-C3), organic carbon (OC), water-soluble OC (WSOC) and major ions to understand the sources and atmospheric processes in the outflow region of Asian pollutants. The molecular distribution of diacids showed the predominance of oxalic acid (C2) followed by malonic and succinic acids in all the size-segregated aerosols. ω-Oxoacids showed the predominance of glyoxylic acid (ωC2) whereas glyoxal (Gly) was more abundant than methylglyoxal in all the sizes. The abundant presence of sulfate as well as phthalic and adipic acids in Okinawa aerosols suggested a significant contribution of anthropogenic sources in East Asia via long-range atmospheric transport. Diacids (C2-C5), ωC2 and Gly as well as WSOC and OC peaked at 0.65-1.1 µm in fine mode whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at 3.3-4.7 µm in coarse mode. Sulfate and ammonium are enriched in fine mode whereas sodium and chloride are in coarse mode. An important mechanism for the formation of these organic species in Okinawa aerosols is probably gas phase oxidation of VOCs and subsequent in-cloud processing during long-range transport. Their characteristics size distribution implies that fine particles enriched with these organic and inorganic species could act as CCN to develop the cloud cover over the western North Pacific. The major peak of C9 and ωC9 on coarse mode suggest that they are produced by photooxidation of unsaturated fatty acids mainly derived from phytoplankton via heterogeneous reactions on sea spray particles. This study demonstrates that anthropogenic aerosols emitted from East Asia have significant influence on the compositions of organic and inorganic aerosols in the western North Pacific Rim.

  7. Bimodal magmatism during the Diego Hernández Formation, Tenerife, Canary Islands: genesis and eruption-triggering of phonolitic magmas during ongoing mafic volcanism

    NASA Astrophysics Data System (ADS)

    Olin, P. H.; Wolff, J. A.; Edgar, C. J.; Cas, R.; Martí, J.

    2008-12-01

    The Diego Hernández Formation (DHF) represents the explosive eruption of nearly 70 cubic km of phonolite over approximately 200 k.y. from the Las Cañadas caldera on Tenerife. Four chemostratigraphic units are distinguished on the basis of trace element contents: DHF bs (represented by the 370 ka Fortaleza and 347 ka Roque Members), DHF I (319 ka Aldea, 309 ka Fasnia, and 268 ka Poris Members), DHF II (Arafo and 223 ka Caleta Members), and DHF III (Cruz Sequence and the 196 ka Abrigo Member); all named units involve plinian and/or ignimbrite components that devastated a significant fraction of the island [1]. These chemostratigraphic units demarcate two dominant compositional trends distinct in incompatible element contents, and in Nb/Ta and REE ratios. DHF bs and DHF III plot along a high-Nb trend, and DHF I and DHF II plot along a low-Nb trend, a feature consistent with divergent fractionation histories involving titanite. Mafic magma was an important component of the DHF magmatic system and flanking mafic volcanism was ongoing during DHF time. Major phonolitic eruptions are conformably bounded by basanitic lavas and scoria deposits. Mafic magmatic components are identifiable in many of the phonolitic pyroclastic deposits as mafic, mingled and banded pumices, or as quenched mafic enclaves. Mafic components in the Abrigo, Caleta, and Poris Members are nearly geochemically identical to the underlying scoria or lava, suggesting that flanking mafic volcanism may in some cases be associated with subcaldera intrusive events that remobilize phonolitic magma to trigger major explosive eruptions. We envisage that the DHF represents a time when the intrusion of mantle-derived mafic magma in the lower crust supplied heat sufficient for the generation of intermediate tephriphonolite and phonotephrite magmas via melting of gabbroic/basaltic crust. Some of these intermediate magmas evolved to phonolite by crystal fractionation, a scenario consistent with DHF III

  8. An integrative geologic, geochronologic and geochemical study of Gorgona Island, Colombia: Implications for the formation of the Caribbean Large Igneous Province

    NASA Astrophysics Data System (ADS)

    Serrano, Lina; Ferrari, Luca; Martínez, Margarita López; Petrone, Chiara Maria; Jaramillo, Carlos

    2011-09-01

    The genesis of the Caribbean Large Igneous Province (CLIP) has been associated to the melting of the Galapagos plume head at ~ 90 Ma or to the interaction between the plume and the Caribbean slab window. Gorgona Island, offshore western Colombia, is an accreted fragment of the CLIP and its highly heterogeneous igneous suite, ranging from enriched basalts to depleted komatiites and picrites, was assumed to have formed at ~ 89 Ma from different part of the plume. Here we present new geologic, geochronologic and geochemical data of Gorgona with significant implications for the formation of the CLIP. A new set of 40Ar- 39Ar ages documents a magmatic activity spanning the whole Late Cretaceous (98.7 ± 7.7 to 64.4 ± 5 Ma) followed by a shallower, picritic pyroclastic eruption in the Paleocene. Trace element and isotope geochemistry confirm the existence of an enriched (EDMM: La/Sm N ≥ 1 and ɛNd i of 5.7 to 7.8) and a depleted (DMM: La/Sm N < 1 and ɛNd i of 9.5 to 11.3) mantle sources. A progressive increase in the degree of melting and melt extraction with time occurred in both groups. Petrologic modeling indicates that low but variable degrees of wet melting (< 5%) of an EDMM can produce the LREE-enriched rocks. Higher degree of melting (> 10%) of a mixed DMM + EDMM (40 to 60%) may reproduce the more depleted rocks with temperatures in the range of ambient mantle in absence of plumes. Our results contradict the notion that the CLIP formed by melting of a plume head at ~ 90 Ma. Multiple magmatic pulses over several tens of Ma in small areas like Gorgona, also recognized in other CLIP areas, suggest a long period of diffuse magmatism without a clear pattern of migration. The age span of this magmatism is broadly concurrent with the Caribbean slab window. During this time span the Farallon oceanic lithosphere (later becoming the Caribbean plate) advanced eastward ~ 1500 km, overriding the astenosphere feeding the proto-Caribbean spreading ridge. This hotter mantle

  9. Rapid thermal rejuvenation of high-crystallinity magma linked to porphyry copper deposit formation; evidence from the Koloula Porphyry Prospect, Solomon Islands

    NASA Astrophysics Data System (ADS)

    Tapster, S.; Condon, D. J.; Naden, J.; Noble, S. R.; Petterson, M. G.; Roberts, N. M. W.; Saunders, A. D.; Smith, D. J.

    2016-05-01

    Magmas containing the components needed to form porphyry copper deposits are relatively common within arcs, yet mineralising events are uncommon within the long-lived magmatic systems that host them. Understanding what causes the transition from barren to productive intrusions is critical to the development of conceptual deposit models. We have constrained the tempo of pre- and syn-mineralisation magmatic events in relationship to the thermal evolution of the plutonic body that underlies one of the world's youngest exposed plutonic-porphyry systems, the Inamumu Zoned Pluton, Koloula Porphyry Prospect, Solomon Islands. High precision ID-TIMS U-Pb dates of texturally and chemically characterised zircons indicate pluton emplacement over <150 kyr was superseded after ca. 50 kyr by two discrete episodes of mineralising porphyritic melt emplacement. Their associated hydrothermal systems initiated within ca. 30 kyrs of each other. Zircon populations within evolved intrusions contain resorbed cores that were recycled from the deeper magmatic system, yet their youngest dates are statistically indistinguishable from those yielded by crystals lacking resorption. Comparisons of Ti-in-zircon proxy temperatures, modelled zircon saturation temperatures and temperature-crystallinity relationships suggest that prior to being heated and emplaced within the shallow level pluton, magmas were stored at depth in a high-crystallinity (>50% crystals) state, past the point of rheological lock-up. We estimate that thermal rejuvenation of the deeper high-crystallinity magma and generation of a mobile melt fraction may have occurred ≤10 kyr before its transport and emplacement within the porphyry environment. The underlying pluton likely cooled and returned to high-crystallinity states prior to subsequent remobilisation-emplacement events. Titanium-in-zircon geothermometry and whole-rock geochemistry suggest pre-mineralisation intrusions were remobilised by mixing of a silicic magma with a

  10. ACR appropriateness criteria acute hip pain-suspected fracture.

    PubMed

    Ward, Robert J; Weissman, Barbara N; Kransdorf, Mark J; Adler, Ronald; Appel, Marc; Bancroft, Laura W; Bernard, Stephanie A; Bruno, Michael A; Fries, Ian Blair; Morrison, William B; Mosher, Timothy J; Roberts, Catherine C; Scharf, Stephen C; Tuite, Michael J; Zoga, Adam C

    2014-02-01

    Substantial cost, morbidity, and mortality are associated with acute proximal femoral fracture and may be reduced through an optimized diagnostic imaging workup. Radiography represents the primary diagnostic test of choice for the evaluation of acute hip pain. In middle aged and elderly patients with negative radiographs, the evidence indicates MRI to be the next diagnostic imaging study to exclude a proximal femoral fracture. CT, because of its relative decreased sensitivity, is only indicated in patients with MRI contraindications. Bone densitometry (DXA) should be obtained in patients with fragility fractures. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  11. [The prevalence of tuberculosis in the state of Acre].

    PubMed

    Moreira, Analdemyra da Costa; Sanchez, Myllianne da Silva; Moreira, Suzianny da Silva; Lopes, Creso Machado

    2004-01-01

    It is a descriptive study with the aim of studying the prevalence of tuberculosis in the State of Acre from 1995 to 2001. The data were collected from the forms of the Program for Tuberculosis Control of the Health and Sanitation Office. The data show that the incidence has been maintaining an average of 343.7 new cases a year. The pulmonary type was the most prevalent one, accounting for 90.0%. Among the age groups, the 20-49 age range, with 1347 (56.0%) and the 60 and over-60 age range, with 412 (17.0%), stand out. From 1998 to 2001 the male sex was the most attacked one by the disease, when the year 2000 accounted for 58.2% of the cases. The average of the cure rate was 71.0% and abandonment of treatment was 14.8% in 2001 and 32.3% in 1995. The smallest percentage of death occurred in 1995 (1.0%) and the largest one in 1997 (7.0%). Five cases were notified for the occurrence of coinfection between TB/AIDS and HIV/TB. The program's population coverage was within 90% every year. From the 22 cities, 6 (27.3%) still do not have any action for controlling the disease.

  12. ACR Appropriateness Criteria Assessment of Fetal Well-Being.

    PubMed

    Simpson, Lynn; Khati, Nadia J; Deshmukh, Sandeep P; Dudiak, Kika M; Harisinghani, Mukesh G; Henrichsen, Tara L; Meyer, Benjamin J; Nyberg, David A; Poder, Liina; Shipp, Thomas D; Zelop, Carolyn M; Glanc, Phyllis

    2016-12-01

    Although there is limited evidence that antepartum testing decreases the risk for fetal death in low-risk pregnancies, women with high-risk factors for stillbirth should undergo antenatal fetal surveillance. The strongest evidence supporting antepartum testing pertains to pregnancies complicated by intrauterine fetal growth restriction secondary to uteroplacental insufficiency. The main ultrasound-based modalities to determine fetal health are the biophysical profile, modified biophysical profile, and duplex Doppler velocimetry. In patients at risk for cardiovascular compromise, fetal echocardiography may also be indicated to ensure fetal well-being. Although no single antenatal test has been shown to be superior, all have high negative predictive values. Weekly or twice-weekly fetal testing has become the standard practice in high-risk pregnancies. The timing for the initiation of assessments of fetal well-being should be tailored on the basis of the risk for stillbirth and the likelihood of survival with intervention. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

  13. The ophiolite of the Eohellenic nappe in the island of Skyros, Greece: Geotectonic environment of formation and metamorphic conditions inferred by mineralogical and geochemical data

    NASA Astrophysics Data System (ADS)

    Karkalis, Christos; Magganas, Andreas; Koutsovitis, Petros

    2014-05-01

    The island of Skyros is located in the Sporades-Aegean region. It includes an ophiolitic mélange sequence consisting of serpentinites, gabbroic and doleritic rocks, and also lavas which mostly appear in massive form, but in rare cases as deformed pillows. The ophiolitic mélange sequence also includes rodingites, ophicalcites, as well as radiolarites. This formation belongs to the Eohellenic tectonic nappe, which encompasses marbles, sandstones and schists and was emplaced onto the Pelagonian Zone during Early Cretaceous [1, 2]. Serpentinites were most likely formed after serpentinization of harzburgitic protoliths and consist of serpentine, bastite, spinel and magnetite. The chemistry of spinels (TiO2=0.14-0.25 wt.%, Al2O3=35.1-35.21 wt.%, Cr#=37.38-38.87), shows that the harzburgitic protoliths plausibly resemble back-arc basin peridotites [3]. Gabbros and dolerites present mostly subophitic textures, between the hornblende/clinopyroxene and plagioclase grains. Based upon their petrography and on their mineral chemistry hornblendes have been distinguished into magmatic and metamorphic hornblendes, with the first occurring mostly in gabbroic rocks. Magmatic hornblendes exhibit relatively high TiO2 (1.42-1.62 wt.%), Al2O3 (5.11-5.86 wt.%) and Na2O (1.01-1.09 wt.%) contents, with their presence implying that the magma was at least to some degree hydrous. Lavas are tholeiitic basalts with relatively high FeOt≡12 wt.% and low K2O and Th contents, consisting mostly albite, altered clinopyroxene and devitrified glass. Tectonomagmatic discrimination diagrams [4, 5] illustrate that the studied gabbros and lavas of Skyros are most likely associated with SSZ processes. Gabbroic rocks, subvolcanic dolerites and lavas have been subjected to greenschist/subgreenschist metamorphic processes, as confirmed by the presence of secondary amphiboles (metamorphic hornblende, actinolite/tremolite), epidote, pumpellyite and chlorite in all of the studied samples. On the other hand

  14. Pseudoatomic Structure of the Tripartite Multidrug Efflux Pump AcrAB-TolC Reveals the Intermeshing Cogwheel-like Interaction between AcrA and TolC.

    PubMed

    Jeong, Hyeongseop; Kim, Jin-Sik; Song, Saemee; Shigematsu, Hideki; Yokoyama, Takeshi; Hyun, Jaekyung; Ha, Nam-Chul

    2016-02-02

    The resistance-nodulation-division type tripartite pump AcrAB-TolC and its homologs are responsible for multidrug resistance in Gram-negative bacteria by expelling a wide variety of toxic substrates. The three essential components, AcrA, AcrB, and TolC, must function in concert with each respective binding partner within the complex. In this study, we report an 8.2-Å resolution cryo-electron microscopy (cryo-EM) 3D reconstruction of the complex that consists of an AcrAB fusion protein and a chimeric TolC protein. The pseudoatomic structure derived from the cryo-EM reconstruction clearly demonstrates a model only compatible with the adaptor bridging mechanism, wherein the funnel-like AcrA hexamer forms an intermeshing cogwheel-like interaction with the α-barrel tip region of TolC. These observations provide a structural milestone for understanding multidrug resistance in pathogenic Gram-negative bacteria, and may also lead to the design of new antibacterial drugs.

  15. A fluorescent microplate assay quantifies bacterial efflux and demonstrates two distinct compound binding sites in AcrB.

    PubMed

    Iyer, Ramkumar; Ferrari, Annette; Rijnbrand, R; Erwin, Alice L

    2015-04-01

    A direct assay of efflux by Escherichia coli AcrAB-TolC and related multidrug pumps would have great value in discovery of new Gram-negative antibiotics. The current understanding of how efflux is affected by the chemical structure and physical properties of molecules is extremely limited, derived from antibacterial data for compounds that inhibit growth of wild-type E. coli. We adapted a previously described fluorescent efflux assay to a 96-well microplate format that measured the ability of test compounds to compete for efflux with Nile Red (an environment-sensitive fluor), independent of antibacterial activity. We show that Nile Red and the lipid-sensitive probe DiBAC4-(3) [bis-(1,3-dibutylbarbituric acid)-trimethine oxonol] can quantify efflux competition in E. coli. We extend the previous findings that the tetracyclines compete with Nile Red and show that DiBAC4-(3) competes with macrolides. The extent of the competition shows a modest correlation with the effect of the acrB deletion on MICs within the compound sets for both dyes. Crystallographic studies identified at least two substrate binding sites in AcrB, the proximal and distal pockets. High-molecular-mass substrates bound the proximal pocket, while low-mass substrates occupied the distal pocket. As DiBAC4-(3) competes with macrolides but not with Nile Red, we propose that DiBAC4-(3) binds the proximal pocket and Nile Red likely binds the distal site. In conclusion, competition with fluorescent probes can be used to study the efflux process for diverse chemical structures and may provide information as to the site of binding and, in some cases, enable rank-ordering a series of related compounds by efflux.

  16. A Fluorescent Microplate Assay Quantifies Bacterial Efflux and Demonstrates Two Distinct Compound Binding Sites in AcrB

    PubMed Central

    Ferrari, Annette; Rijnbrand, R.; Erwin, Alice L.

    2015-01-01

    A direct assay of efflux by Escherichia coli AcrAB-TolC and related multidrug pumps would have great value in discovery of new Gram-negative antibiotics. The current understanding of how efflux is affected by the chemical structure and physical properties of molecules is extremely limited, derived from antibacterial data for compounds that inhibit growth of wild-type E. coli. We adapted a previously described fluorescent efflux assay to a 96-well microplate format that measured the ability of test compounds to compete for efflux with Nile Red (an environment-sensitive fluor), independent of antibacterial activity. We show that Nile Red and the lipid-sensitive probe DiBAC4-(3) [bis-(1,3-dibutylbarbituric acid)-trimethine oxonol] can quantify efflux competition in E. coli. We extend the previous findings that the tetracyclines compete with Nile Red and show that DiBAC4-(3) competes with macrolides. The extent of the competition shows a modest correlation with the effect of the acrB deletion on MICs within the compound sets for both dyes. Crystallographic studies identified at least two substrate binding sites in AcrB, the proximal and distal pockets. High-molecular-mass substrates bound the proximal pocket, while low-mass substrates occupied the distal pocket. As DiBAC4-(3) competes with macrolides but not with Nile Red, we propose that DiBAC4-(3) binds the proximal pocket and Nile Red likely binds the distal site. In conclusion, competition with fluorescent probes can be used to study the efflux process for diverse chemical structures and may provide information as to the site of binding and, in some cases, enable rank-ordering a series of related compounds by efflux. PMID:25645845

  17. ACR Appropriateness Criteria Low Back Pain.

    PubMed

    Patel, Nandini D; Broderick, Daniel F; Burns, Judah; Deshmukh, Tejaswini K; Fries, Ian Blair; Harvey, H Benjamin; Holly, Langston; Hunt, Christopher H; Jagadeesan, Bharathi D; Kennedy, Tabassum A; O'Toole, John E; Perlmutter, Joel S; Policeni, Bruno; Rosenow, Joshua M; Schroeder, Jason W; Whitehead, Matthew T; Cornelius, Rebecca S; Corey, Amanda S

    2016-09-01

    Most patients presenting with uncomplicated acute low back pain (LBP) and/or radiculopathy do not require imaging. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags raising suspicion for serious underlying conditions, such as cauda equina syndrome, malignancy, fracture, and infection. Many imaging modalities are available to clinicians and radiologists for evaluating LBP. Application of these modalities depends largely on the working diagnosis, the urgency of the clinical problem, and comorbidities of the patient. When there is concern for fracture of the lumbar spine, multidetector CT is recommended. Those deemed to be interventional candidates, with LBP lasting for > 6 weeks having completed conservative management with persistent radiculopathic symptoms, may seek MRI. Patients with severe or progressive neurologic deficit on presentation and red flags should be evaluated with MRI. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

  18. ACR Appropriateness Criteria pretreatment staging of colorectal cancer.

    PubMed

    Dewhurst, Catherine; Rosen, Max P; Blake, Michael A; Baker, Mark E; Cash, Brooks D; Fidler, Jeff L; Greene, Frederick L; Hindman, Nicole M; Jones, Bronwyn; Katz, Douglas S; Lalani, Tasneem; Miller, Frank H; Small, William C; Sudakoff, Gary S; Tulchinsky, Mark; Yaghmai, Vahid; Yee, Judy

    2012-11-01

    Because virtually all patients with colonic cancer will undergo some form of surgical therapy, the role of preoperative imaging is directed at determining the presence or absence of synchronous carcinomas or adenomas and local or distant metastases. In contrast, preoperative staging for rectal carcinoma has significant therapeutic implications and will direct the use of radiation therapy, surgical excision, or chemotherapy. CT of the chest, abdomen, and pelvis is recommended for the initial evaluation for the preoperative assessment of patients with colorectal carcinoma. Although the overall accuracy of CT varies directly with the stage of colorectal carcinoma, CT can accurately assess the presence of metastatic disease. MRI using endorectal coils can accurately assess the depth of bowel wall penetration of rectal carcinomas. Phased-array coils provide additional information about lymph node involvement. Adding diffusion-weighted imaging to conventional MRI yields better diagnostic accuracy than conventional MRI alone. Transrectal ultrasound can distinguish layers within the rectal wall and provides accurate assessment of the depth of tumor penetration and perirectal spread, and PET and PET/CT have been shown to alter therapy in almost one-third of patients with advanced primary rectal cancer. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

  19. Late Quaternary climate change shapes island biodiversity.

    PubMed

    Weigelt, Patrick; Steinbauer, Manuel Jonas; Cabral, Juliano Sarmento; Kreft, Holger

    2016-04-07

    Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.

  20. Overexpression of the Multidrug Efflux Operon acrEF by Insertional Activation with IS1 or IS10 Elements in Salmonella enterica Serovar Typhimurium DT204 acrB Mutants Selected with Fluoroquinolones

    PubMed Central

    Olliver, Anne; Vallé, Michel; Chaslus-Dancla, Elisabeth; Cloeckaert, Axel

    2005-01-01

    High-level fluoroquinolone (FQ) resistance in Salmonella enterica serovar Typhimurium phage type DT204 has been previously shown to be essentially due to both multiple target gene mutations and active efflux by the AcrAB-TolC efflux system. In this study we show that in intermediatly resistant acrB-inactivated serovar Typhimurium DT204 mutants, high-level resistance to FQs can be restored on in vitro selection with FQs. In each FQ- resistant mutant selected from serovar Typhimurium DT204 acrB mutant strains, an insertion sequence (IS1 or IS10) was found integrated upstream of the acrEF operon, coding for AcrEF, an efflux pump highly homologous to AcrAB. In one of the strains, transposition of IS1 caused partial deletion of acrS, the putative local repressor gene of the acrEF operon. Sequence analysis showed that both IS1 and IS10 elements contain putative promoter sequences that might alter the expression of adjacent acrEF genes. Indeed, reverse transcription-PCR experiments showed an 8- to 10-fold increase in expression of acrF in these insertional mutants, relative to their respective parental strain, which correlated well with the resistance levels observed to FQs and other unrelated drugs. It is noteworthy that AcrEF did not contribute to the intrinsic drug resistance of serovar Typhimurium, since acrF deletion in wild-type strains did not result in any increase in drug susceptibility. Moreover, deletion of acrS did not cause any acrF overexpression or any decrease in drug susceptibility, suggesting that acrEF overexpression is mediated solely by the IS1 and IS10 promoter sequences and not by inactivity of AcrS. Southern blot experiments showed that the number of chromosomal IS1 and IS10 elements in the serovar Typhimurium DT204 genome was about 5 and 15 respectively. None were detected in epidemic serovar Typhimurium DT104 strains or in the serovar Typhimurium reference strain LT2. Carrying IS1 and/or IS10 elements in their chromosome may thus be a selective

  1. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... each summer since 1999, researchers from NASA's Haughton-Mars Project and the Mars Society reside at this "polar desert" location to study the geologic and ...

  2. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... deepest ocean trench. Anatahan had no known historical eruptions until May 2003. The evacuation of the island's residents in 1990 was ... earthquake swarm that suggested the possibility of impending volcanic activity. The Micronesian Megapode is an endangered species of ...

  3. Superfund Record of Decision (EPA Region 1): Salem Acres Site, Salem, MA, March 1993

    SciTech Connect

    Not Available

    1993-03-01

    This decision document represents the selected remedial action for the Salem Acres Site in Salem, Massachusetts. The remedial action for the Salem Acres Site, as described in this ROD, addresses the principal threats to the human health and the environment posed by exposure of humans to contaminated soils from the Salem Acres Site. This remedy addresses all principal threats to human health and the environment posed by the sources of contamination at the Site resulting from dermal absorption and incidental ingestion of contaminants in surficial soils.

  4. 77 FR 74697 - Meeting of the ACRS, Subcommittee on U.S. Evolutionary Power Reactor; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS, Subcommittee on U.S. Evolutionary Power Reactor; Notice of Meeting The ACRS Subcommittee on U.S. Evolutionary Power Reactor (U.S..., 2012. Antonio Dias, Technical Advisor, Advisory Committee on Reactor Safeguards. BILLING CODE 7590-01-P...

  5. ACR 2016 Open-Microphone Session: ACR Membership 3.0-Moving From Member Volume to Value.

    PubMed

    Stern, Eric; Metter, Darlene; Everett, Catherine; Flug, Jonathan; Friedberg, Eric; Kotsenas, Amy; Nathan, Jennifer; Herrington, William

    2017-04-02

    This report of the 2016 ACR Council Open Microphone session reviews the discussion around interests and concerns of council members and state chapter leaders as to the perceived and real value of their ACR membership, and how the ACR might further enhance membership value and meaningful engagement with members.

  6. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  7. 75 FR 69154 - Land Release for Long Island MacArthur Airport

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-10

    ... proposed release from aeronautical use of approximately 17.69 acres of airport property, to allow for non-aeronautical development. The parcel is located on the northeast corner of the Long Island MacArthur Airport... sponsor's Federal obligation to use certain airport land for aeronautical use. Issued in Garden City,...

  8. PHYTOREMEDIATION OF DREDGED SEDIMENTS: A CASE STUDY AT THE JONES ISLAND CDF

    EPA Science Inventory

    The Jones Island Confined Disposal Facility (CDF) is a 44 acre in-lake area that receives dredged material from Milwaukee Harbor and the surrounding waterways. Some of those materials are contaminated with industrial waste and urban run-off. The CDF is nearing the end of its desi...

  9. Authigenic pyrite formation and re-oxidation as an indicator of an unsteady-state redox sedimentary environment: Evidence from the intertidal mangrove sediments of Hainan Island, China

    NASA Astrophysics Data System (ADS)

    Ding, Hai; Yao, Suping; Chen, Jun

    2014-04-01

    Two cores of intertidal mangrove sediments from the Tanmen and Qinglan Harbors on Hainan Island, China, were investigated for their geochemical characteristics of carbon, nitrogen, iron and sulfur and the pyrite morphology and framboidal pyrite size distribution. A modified sequential iron extraction procedure revealed extremely high FeHR/FeT ratios (0.81±0.07, n=28). The pyrite results determined by the nitric acid digestion and chromium reduction method show a strong correlation (r=0.91, n=28), indicating that most of the chromium-reducible sulfur is pyrite, whereas the proportion of elemental sulfur is minor. The organic carbon concentrations and the atomic C/N ratios demonstrate that the organic carbon in the mangrove sediments is derived predominantly from higher plants. The chromium-reducible sulfur (CRS) values show a good linear logarithmic correlation with the total organic carbon (TOC), indicating that the process of sulfate reduction increases rapidly with the concentration of TOC at Qinglan Harbor (QL), which has low TOC contents (<5 wt%). In contrast, sulfate reduction increases slowly with high TOC (>5 wt%) at Tanmen Harbor (TM). These data suggest that pyrite formation at the QL site is controlled by the TOC contents, whereas at the TM site, the primary factor controlling the pyritization process is the supply rate of sulfate. Both sites have significantly high sulfate contents (average 1.67±0.45 wt% and 0.80±0.32 wt% at Tanmen and Qinglan, respectively), which are isotopically depleted in 34S (average -6.15±7.17‰ and -6.72±7.33‰ at Tanmen and Qinglan, respectively) suggesting that the sulfate is mainly from the reoxidation of reduced sulfides (mainly pyrite) instead of seawater sulfate during burial. The distributions of pyrite textures suggest that the pyrite in the mangrove swamps is formed mainly as framboids and only a few pyrite crystals are formed directly as euhedral crystals. The high mean diameters and standard deviations (7.0±4

  10. Mantle heterogeneity during the formation of the North Atlantic Igneous Province: Constraints from trace element and Sr-Nd-Os-O isotope systematics of Baffin Island picrites

    NASA Astrophysics Data System (ADS)

    Kent, A. J. R.; Stolper, E. M.; Francis, D.; Woodhead, J.; Frei, R.; Eiler, J.

    2004-11-01

    Sr-Nd-Os-O isotope and major and trace element data from ˜62 Ma picrites from Baffin Island constrain the composition of mantle sources sampled at the inception of North Atlantic Igneous Province (NAIP) magmatism. We recognize two compositional types. Depleted (N-type) lavas have low 87Sr/86Sri (0.702990-0.703060) and 187Os/188Osi (0.1220-0.1247) and high 143Nd/144Ndi (0.512989-0.512999) and are depleted in incompatible elements relative to primitive mantle. Enriched (E-type) lavas have higher 87Sr/86Sri (0.703306-0.703851) and 187Os/188Osi (0.1261-0.1303), lower 143Nd/144Ndi (0.512825-0.512906), and incompatible element concentrations similar to, or more enriched than, primitive mantle. There is also a subtle difference in oxygen isotope composition; E-type lavas are marginally lower in δ18Oolivine value (5.16-4.84‰) than N-type lavas (5.15-5.22‰). Chemical and isotopic variations between E- and N-type lavas are inconsistent with assimilation of crust and/or subcontinental lithospheric mantle and appear to instead reflect mixing between melts derived from two distinct mantle sources. Strontium-Nd-O isotope compositions and incompatible trace element abundances of N-type lavas suggest these are largely derived from the depleted upper mantle. The 187Os/188Osi ratios of N-type lavas can also be explained by such a model but require that the depleted upper mantle had γOs of approximately -5 to -7 at 62 Ma. This range overlaps the lowest γOs values measured in abyssal peridotites. Baffin Island lava compositions are also permissive of a model involving recharging of depleted upper mantle with 3He-rich material from the lower mantle (Stuart et al., Nature, 424, 57-59, 2003), with the proviso that recharge had no recognizable effect on the lithophile trace element and Sr-Nd-Os-O isotope composition. The origin of the enriched mantle component sampled by Baffin Island lavas is less clear but may be metasomatized and high-temperature-altered recycled oceanic

  11. 43 CFR 2524.7 - Disposal of lands in excess of 160 acres.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.7 Disposal of lands in excess of 160 acres....

  12. 43 CFR 2524.7 - Disposal of lands in excess of 160 acres.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.7 Disposal of lands in excess of 160 acres....

  13. 43 CFR 2524.7 - Disposal of lands in excess of 160 acres.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.7 Disposal of lands in excess of 160 acres....

  14. 43 CFR 2524.7 - Disposal of lands in excess of 160 acres.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.7 Disposal of lands in excess of 160 acres....

  15. Dunbar Asphalt to Clean up 29-Acre Portion of Sharon Steel Superfund Site, Hermitage, Pa.

    EPA Pesticide Factsheets

    PHILADELPHIA (Sept. 14, 2015) The U.S. Environmental Protection Agency today announced a proposed settlement the government has reached with Dunbar Asphalt Products, Inc., to clean up a 29-acre portion of the Sharon Steel Corporation Superfund Site

  16. The Cambrian of Bennett Island (New Siberian Islands)

    NASA Astrophysics Data System (ADS)

    Danukalova, M. K.; Kuzmichev, A. B.; Korovnikov, I. V.

    2014-07-01

    The paper presents new data on the Cambrian stratigraphy of Bennett Island, one of the least explored East Arctic islands. The section, about 500 m of total thickness, comprises four lithological units that store a record of the deposition history: (1) clastic sediments including storm sandstones; (2) shallow-marine mudstone; (3) lagoonal variegated mudstone and limestone; (4) black shale. It is suggested to classify the units as formations with their proper names. The section spans all epoches of the Cambrian stratigraphy constrained by trilobite fossils. In the Cambrian, territory of the island belonged to Siberia rather than to some exotic terrane, judging by abundant endemic Siberian trilobite species in the Bennett section. This inference is supported by synchronicity in recorded deposition events of Bennett Island and northeastern Siberia (Kharaulakh Mountains). The Cambrian sediments of the two areas were deposited in different parts of a single shallow sea which extended as far as Taimyr.

  17. BVOCs concentration in the Reunion Island tropical forests and the impact on photooxidants formation during the BIO-MAIDO 2015 campaign.

    NASA Astrophysics Data System (ADS)

    Colomb, Aurelie; Duflot, Valentin; Tulet, Pierre; Flores, Olivier; Fournel, Jacques; Strasberg, Dominique; Deguillaume, Laurent; Vaitilingom, Mickael; Burnet, Frederic; Bourrianne, Thierry

    2016-04-01

    In March-April 2015 took place an intensive field campaign in the Reunion Island : BIO-MAÏDO 2015 campaign. The main objective of the campaign was to study the interactions between forests, gases, aerosols and clouds in this unique tropical natural science lab (Duflot at al, in prep). During this campaign volatile organic compounds (VOCs) including biogenic volatile organic compounds (BVOCs) were sampled at different part of the Reunion island. BVOCs (including isoprene, terpenes, and some oxygenated compounds) have different temporal and spatial variations depending on vegetation, on plant species and on environmental factors (ambient temperature, light intensity, air pollution..) (Seinfeld and Pandis, 1998, Kesselmeier and Staudt, 1999). BVOCs are important atmospheric constituent of the troposphere. Due to high reactivity they have an important impact on the tropospheric hydroxyl radical (OH) and ozone (Granier et al., 2000; Poisson et al., 2000; Pfister et al., 2008), thus thave a significantey influence on the oxidative capacity of the atmosphere (Houweling et al., 1998; Taraborrelli et al., 2012) on regional and global scales. BVOCs were studied at different locations: Maido Observatory (2160m) with semi-continous measurement (12 March - 9 April 2015); Tamarins forest; Cryptomeria forest; Primary forest (Belouve) and Mare Longue forest . BVOCs were sampled on adsorbents cartridges containing 250 mg Tenax TA and analysed later with a gas-chromatography-mass spectrometer. Formaldehyde concentrations were determined at the Maido observatory using an AEROLASER 4021 instrument, based on the so called "Hantzsch"-reaction, and with a 30s resolution. Isoprene was the most important BVOCs concentration found in the Reunion Island forest, especially from the endemic Tamarins trees, followed by limonene and alpha-pinene. Formaldehyde at the Maido facility show a strong diurnal variation and a maximum concentration during day-time from 1 to 4 ppbv. The local emission of

  18. Formation and evolution of a metasomatized lithospheric root at the motionless Antarctic plate: the case of East Island, Crozet Archipelago (Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Meyzen, Christine; Marzoli, Andrea; Bellieni, Giuliano; Levresse, Gilles

    2016-04-01

    Sitting atop the nearly stagnant Antarctic plate (ca. 6.46 mm/yr), the Crozet archipelago midway between Madagascar and Antarctica constitutes a region of unusually shallow (1543-1756 m below sea level) and thickened oceanic crust (10-16.5 km), high geoid height, and deep low-velocity zone, which may reflect the surface expression of a mantle plume. Here, we present new major and trace element data for Quaternary sub-aerial alkali basalts from East Island, the easterly and oldest island (ca. 9 Ma) of the Crozet archipelago. Crystallization at uppermost mantle depth and phenocryst accumulation have strongly affected their parental magma compositions. Their trace element patterns show a large negative K anomaly relative to Ta-La, moderate depletions in Rb and Ba with respect to Th-U, and heavy rare earth element (HREE) depletions relative to light REE. These characteristics allow limits to be placed upon the composition and mineralogy of their mantle source. The average trace element spectrum of East Island basalts can be matched by melting of about 2 % of a garnet-phlogopite-bearing peridotite source. The stability field of phlogopite restricts melting depth to lithospheric levels. The modelled source composition requires a multistage evolution, where the mantle has been depleted by melt extraction before having been metasomatized by alkali-rich plume melts. The depleted mantle component may be sourced by residual mantle plume remnants stagnated at the melting locus due to a weak lateral flow velocity inside the melting regime, whose accumulation progressively edifies a depleted lithospheric root above the plume core. Low-degree alkali-rich melts are likely derived from the plume source. Such a mantle source evolution may be general to both terrestrial and extraterrestrial environments where the lateral component velocity of the mantle flow field is extremely slow.

  19. Constraints on formation processes of two coarse-grained calcium- aluminum-rich inclusions: a study of mantles, islands and cores

    USGS Publications Warehouse

    Meeker, G.P.

    1995-01-01

    Many coarse-grained calcium- aluminum-rich inclusions (CAIs) contain features that are inconsistent with equilibrium liquid crystallization models of origin. Spinel-free islands (SFIs) in spinel-rich cores of Type B CAIs are examples of such features. One model previously proposed for the origin of Allende 5241, a Type B1 CAI containing SFIs, involves the capture and assimilation of xenoliths by a liquid droplet in the solar nebula (El Goresy et al, 1985; MacPherson et al 1989). This study reports new textural and chemical zoning data from 5241 and identifies previously unrecognized chemical zoning patterns in the melilite mantle and in a SFI. -from Author

  20. Hydrogeologic reconnaissance of Poro Point and vicinity, Luzon Island, Philippines

    USGS Publications Warehouse

    Worts, George Frank

    1964-01-01

    In 1961 a reconnaissance of the geology and ground-water hydrology of Poro Point, on the west coast of Luzon Island, Philippines, was made on behalf of the U.S. Department of the Navy. Poro Point, which marks the northern end of Lingayen Gulf, is about half a mile wide and projects northwestward about 2 miles into the China Sea. The point is underlain by coralline limestone of probable Pleistocene age. The aquifer system consists of a fresh-water lens floating on salt water within the coralline limestone. Several tube wells obtain fresh water from the lens, but in May, at the end of the 6-month dry season during which rainfall totals only 40 inches, the water becomes brackish. 'Skimming wells' are considered the best method of obtaining fresh water from the lens, whose annual range in average thickness is probably 25 to 40 feet. Recharge is about 2,000-3,000 acre-feet per year and is derived wholly from precipitation during the 6-month wet season in which rainfall totals about 92 inches. The approximate amount of ground water stored in the fresh-water lens ranges from about 3,000 acre-feet at the end of the dry season to about 5,000 acre-feet at the end of the wet season. Most of the ground water is discharged through seeps and submarine springs around Poro Point; pumpage in 1961 was only about 100 acre-feet.

  1. Dendrochronology of Strain-Relaxed Islands

    SciTech Connect

    Merdzhanova, T.; Kiravittaya, S.; Rastelli, A.; Stoffel, M.; Denker, U.; Schmidt, O.G.

    2006-06-09

    We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes.

  2. Dendrochronology of strain-relaxed islands.

    PubMed

    Merdzhanova, T; Kiravittaya, S; Rastelli, A; Stoffel, M; Denker, U; Schmidt, O G

    2006-06-09

    We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes.

  3. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  4. Radiation release and health effects lessons from the Three Mile Island incident: assessment of objective risks for emergency preparedness planning

    SciTech Connect

    Berger, C.D.; Mynatt, F.R.

    1980-01-01

    The accepted theories of radiation health effects are briefly discussed so that the Three Mile Island health effects estimations can be better understood. The author recommends that emergency response planners weigh the objective risks rather than the perceived risks of low-level radiation against those associated with evacuation of large population zones before a final plan is put into effect. (ACR)

  5. Geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska

    SciTech Connect

    Motyka, R.J.; Wescott, E.M.; Turner, D.L.; Swanson, S.E.; Romick, J.D.; Moorman, M.A.; Poreda, R.J.; Witte, W.; Petzinger, B.; Allely, R.D.

    1985-01-01

    An extensive survey was conducted of the geothermal resource potential of Hot Springs Bay Valley on Akutan Island. A topographic base map was constructed, geologic mapping, geophysical and geochemical surveys were conducted, and the thermal waters and fumarolic gases were analyzed for major and minor element species and stable isotope composition. (ACR)

  6. Distributed Wind Case Study: Cross Island Farms, Wellesley Island, New York

    SciTech Connect

    2012-04-30

    Installing a small wind turbine can sometimes be challenging due to economics, zoning issues, public perception, and other barriers. Persistence and innovation, however, can result in a successful installation. Dani Baker and David Belding own Cross Island Farms, a 102-acre certified organic farm on Wellesley Island in northern New York. In 2009, they took their interest in renewable energy to the next level by researching the logistics of a small wind installation on their land to make their farm even more sustainable. Their renewable energy system consists of one 10-kilowatt Bergey Excel wind turbine, a solar array, and a propane-powered generator. This case study describes funding for the project and the installation process.

  7. Distributed Wind Case Study: Cross Island Farms, Wellesley Island, New York (Fact Sheet)

    SciTech Connect

    Not Available

    2012-04-01

    Installing a small wind turbine can sometimes be difficult due to economics, zoning issues, public perception, and other barriers. Persistence and innovation, however, can result in a successful installation. Dani Baker and David Belding own Cross Island Farms, a 102-acre certified organic farm on Wellesley Island in northern New York. In 2009, they took their interest in renewable energy to the next level by researching the logistics of a small wind installation on their land to make their farm even more sustainable. Their renewable energy system consists of one 10-kilowatt Bergey Excel wind turbine, a solar array, and a propane-powered generator. This case study describes funding for the project and the installation process.

  8. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  9. Seasonal variations of diacids, ketoacids, and α-dicarbonyls in aerosols at Gosan, Jeju Island, South Korea: Implications for sources, formation, and degradation during long-range transport

    NASA Astrophysics Data System (ADS)

    Kundu, Shuvashish; Kawamura, Kimitaka; Lee, Meehye

    2010-10-01

    Aerosol samples (n = 84) were collected continuously from April 2003 to April 2004 at Gosan site in Jeju Island, South Korea. The samples were analyzed for diacids, ketoacids, and α-dicarbonyls, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and water-soluble inorganic ions. Oxalic acid (C2) was the most abundant followed by malonic acid (C3) in all the seasons. The mean concentration (784 ng m-3) of total diacids (C2-C12) and their relative abundances in total organic species detected, OC and WSOC were found to be the highest in summer, whereas those of ketoacids and dicarbonyls were the highest in winter. The annual mean contributions of diacids, ketoacids, and dicarbonyls to WSOC are 12, 1, and 0.4%, respectively. They are several times higher than those reported in East Asia from which air masses are transported to Gosan, indicating an importance of photochemical processing of aerosols during a long-range transport. Diacids and related compounds show different seasonal variations, suggesting their season-specific sources and photochemical processing. This study demonstrates an enhanced photochemical production and degradation of water-soluble organics in summer. In contrast, higher positive correlations between combustion tracers (non-sea-salt K+ and EC) and diacids and related compounds were observed in the winter, pointing out higher emission of diacids and related compounds or their precursors from fossil fuel/biomass burning.

  10. 10 CFR 52.87 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.87 Section 52.87 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.87 Referral to the Advisory Committee...

  11. 10 CFR 52.165 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.165 Section 52.165 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Manufacturing Licenses § 52.165 Referral to the...

  12. 10 CFR 52.165 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.165 Section 52.165 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Manufacturing Licenses § 52.165 Referral to the...

  13. 10 CFR 52.23 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.23 Section 52.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Early Site Permits § 52.23 Referral to the Advisory...

  14. 10 CFR 52.87 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.87 Section 52.87 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.87 Referral to the Advisory Committee...

  15. 10 CFR 52.165 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.165 Section 52.165 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Manufacturing Licenses § 52.165 Referral to the...

  16. 10 CFR 52.87 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.87 Section 52.87 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.87 Referral to the Advisory Committee...

  17. 10 CFR 52.23 - Referral to the Advisory Committee on Reactor Safeguards (ACRS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Referral to the Advisory Committee on Reactor Safeguards (ACRS). 52.23 Section 52.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Early Site Permits § 52.23 Referral to the Advisory...

  18. 42 CFR 417.594 - Computation of adjusted community rate (ACR).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Computation of adjusted community rate (ACR). 417.594 Section 417.594 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM (CONTINUED) HEALTH MAINTENANCE ORGANIZATIONS,...

  19. Transport of lipophilic carboxylates is mediated by transmembrane helix 2 in multidrug transporter AcrB

    PubMed Central

    Oswald, Christine; Tam, Heng-Keat; Pos, Klaas M.

    2016-01-01

    The deployment of multidrug efflux pumps is a powerful defence mechanism for Gram-negative bacterial cells when exposed to antimicrobial agents. The major multidrug efflux transport system in Escherichia coli, AcrAB–TolC, is a tripartite system using the proton-motive force as an energy source. The polyspecific substrate-binding module AcrB uses various pathways to sequester drugs from the periplasm and outer leaflet of the inner membrane. Here we report the asymmetric AcrB structure in complex with fusidic acid at a resolution of 2.5 Å and mutational analysis of the putative fusidic acid binding site at the transmembrane domain. A groove shaped by the interface between transmembrane helix 1 (TM1) and TM2 specifically binds fusidic acid and other lipophilic carboxylated drugs. We propose that these bound drugs are actively displaced by an upward movement of TM2 towards the AcrB periplasmic porter domain in response to protonation events in the transmembrane domain. PMID:27982032

  20. Escherichia coli mar and acrAB mutants display no tolerance to simple alcohols.

    PubMed

    Ankarloo, Jonas; Wikman, Susanne; Nicholls, Ian A

    2010-03-31

    The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g., phage display screening, are discussed.

  1. Implementation of the ACR dose index registry at a large academic institution: early experience.

    PubMed

    Robinson, Tracy J; Robinson, Jeffrey D; Kanal, Kalpana M

    2013-04-01

    A rising conciousness within both the medical community and in the public has been created by the current levels of radiation exposure from increased use of computed tomography. The concern has prompted the need for more data collection and analysis of hospital and imaging center exam doses. This has spurred the American College of Radiology (ACR) to develop the Dose Index Registry (DIR), which will allow participating insitutions to compare the radiation dose from their CT exams to aggregate national CT dose data based on exam type and body part. We outline the steps involved in the process of enrolling in the DIR, the technical requirements, the challenges we encountered, and our solutions to those challenges. A sample of the quaterly report released by the ACR is presented and discussed. Enrolling in the ACR dose registry is a team effort with participation from IT, a site physicist, and a site radiologist. Participation in this registry is a great starting point to initiate a QA process for monitoring CT dose if none has been established at an institution. The ACR has developed an excellent platform for gathering, analyzing, and reporting CT dose data. Even so, each insititutions will have its own unique issues in joining the project.

  2. Forest Fires in Southwestern Amazonia During 2005: Extent and Distribution in Eastern Acre State, Brazil

    NASA Astrophysics Data System (ADS)

    Brown, I.; Moulard, E. M.; Nakamura, J.; Schroeder, W.; Maldonado, M.; Vasconcelos, S. S.; Selhorst, D.

    2007-05-01

    The extended drought in western Amazonia during 2005 provided the conditions for wild fires that spread in old- growth rain forests and cleared areas of the contiguous areas of Madre de Dios, Peru, Acre, Brazil, and Pando, Bolivia, collectively known as the MAP Region. The greatest extent of the wild fires occurred in eastern Acre State with 60,000 km2 of diverse land uses that range from intensely occupied colonization areas, large cattle ranches, extractive and biological reserves and indigenous areas. At the request of the Public Ministry of Acre and other government agencies we analyzed Landsat 5 and CBERS 2 imagery for forests with canopies affected by fires, using visual interpretation and manual digitalization of polygons. Accuracy assessment was done with 180 aerial photos. The total area of forest with canopies affected by fires was 267,000 ha, roughly five times recent annual deforestation rates for Acre State. Omission and commission errors were 28% and 2%, respectively. Burn scars in non-forest areas were determined using ASTER and CBERS 2 imagery via supervised classification. Total open area with burn scars was 203,000 ha. The total of open area and forests affected by fires exceeded 470,000 ha due to three factors: (1) some images used did not include the last weeks of burning; (2) ground fires in forests that did not affect the canopy and therefore were not detected; and (3) concern of the interpreters to avoid commission errors. Of the twelve municipalities of eastern Acre, most affected were Acrelandia, Placido de Castro, Epitaciolandia with >31%, >19% and >17% of the municipality affected, respectively). The largest impact, >114,000 ha, occurred in the Rio Branco Municipality. Similar patterns of burning occurred in Pando and in Madre de Dios. The environmental, social and economic disaster that these fires produced may be a harbinger of future impacts in southwestern Amazonia if current climate predictions prove to be correct.

  3. VizieR Online Data Catalog: Astrographic Catalog Reference Stars (ACRS) (Corbin+ 1991)

    NASA Astrophysics Data System (ADS)

    Corbin, T. E.; Urban, S. E.; Warren, W. H., Jr.

    1995-11-01

    The ACRS is an all-sky catalog of positions and proper motions that is based on the AGK3 in the north and on the newly completed second Cape Photographic Catalogue (CPC2, de Vegt et al. 1989) in the south. The astrometric data are on the system of the International Reference Stars (IRS, catalog ), compiled on B1950.0 FK4 and then transformed to J2000.0 FK5. The ACRS contains 320,111 stars, the mean positions for which were derived from a total of 1,643,783 individual input positions. The catalog is divided into two parts. Part 1 contains stars having better observational histories and, therefore, more reliable positions and proper motions, while the stars in Part 2 have poor histories and consist mostly of objects for which only two catalog positions in one or both coordinates were available for computing proper motions. For Part 1, which consists of 78 percent of the catalog, the mean errors of the proper motions in right ascension and declination are 0.47 and 0.46 seconds of arc/century (4.7 and 4.6 mas/yr), respectively. It is intended that, as more observations are accumulated for stars in Part 2, they will be migrated to Part 1. The catalog was compiled at the U.S. Naval Observatory, Washington, D.C., for purposes of performing new reductions of the Astrographic Catalogue plates. Additional details about the construction of the ACRS may be found in Corbin and Urban (1989). The data included are catalog part, ACRS number, equatorial coordinates (equinox, equator, epoch B1950.0 and J2000.0), proper motions (B1950.0 and J2000.0), original epochs, weights for right ascension and declination, and reference data such as DM numbers (BD, CD, CPD), AGK3 and CPC2 designations, and an IAU recommended ACRS identifier (based on coordinates). (2 data files).

  4. Comparison of Irrigation Water Use Estimates Calculated from Remotely Sensed Irrigated Acres and State Reported Irrigated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

    USGS Publications Warehouse

    Masoner, J.R.; Mladinich, C.S.; Konduris, A.M.; Smith, S. Jerrod

    2003-01-01

    Increased demand for water in the Lake Altus drainage basin requires more accurate estimates of water use for irrigation. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation, is investigating new techniques to improve water-use estimates for irrigation purposes in the Lake Altus drainage basin. Empirical estimates of reference evapotranspiration, crop evapotranspiration, and crop irrigation water requirements for nine major crops were calculated from September 1999 to October 2000 using a solar radiation-based evapotranspiration model. Estimates of irrigation water use were calculated using remotely sensed irrigated crop acres derived from Landsat 7 Enhanced Thematic Mapper Plus imagery and were compared with irrigation water-use estimates calculated from irrigated crop acres reported by the Oklahoma Water Resources Board and the Texas Water Development Board for the 2000 growing season. The techniques presented will help manage water resources in the Lake Altus drainage basin and may be transferable to other areas with similar water management needs. Irrigation water use calculated from the remotely sensed irrigated acres was estimated at 154,920 acre-feet; whereas, irrigation water use calculated from state reported irrigated crop acres was 196,026 acre-feet, a 23 percent difference. The greatest difference in irrigation water use was in Carson County, Texas. Irrigation water use for Carson County, Texas, calculated from the remotely sensed irrigated acres was 58,555 acrefeet; whereas, irrigation water use calculated from state reported irrigated acres was 138,180 acre-feet, an 81 percent difference. The second greatest difference in irrigation water use occurred in Beckham County, Oklahoma. Differences between the two irrigation water use estimates are due to the differences of irrigated crop acres derived from the mapping process and those reported by the Oklahoma Water Resources Board and Texas Water Development Board.

  5. 76 FR 13437 - Advisory Committee on Reactor Safeguards; Meeting of the ACRS Subcommittee on Reliability and PRA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-11

    ...; Revision to March 24, 2010, ACRS Meeting Federal Register Notice The Federal Register Notice for the ACRS Subcommittee Meeting on Reliability and Probabilistic Risk Assessment scheduled to be held on March 24, 2011... Wednesday, March 2, 2011, . Further information regarding this meeting can be obtained by contacting...

  6. ZipperCream-CG and WhiteAcre-DG: Two Newly-released, Cream-type Southernpea Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efforts to incorporate genes conditioning a persistent green seed phenotype into Zipper Cream and White Acre type backgrounds were completed with the official release of the new southernpea cultivars ZipperCream-CG and WhiteAcre-DG on 29 January 2008. ZipperCream-CG is a high yielding, large-seeded...

  7. Impact of generational differences on the future of radiology: proceedings of the 11th annual ACR Forum.

    PubMed

    Krishnaraj, Arun; Weinreb, Jeffrey C; Ellenbogen, Paul H; Patti, John A; Hillman, Bruce J

    2012-02-01

    The 2011 ACR Forum focused on the impact of generational differences on the future of radiology, seeking to inform ACR leadership and members on how best to address the influence of the new integrated workforce on the specialty of radiology and on individual practices.

  8. Climate change: Effects on reef island resources

    SciTech Connect

    Oberdorfer, J.A.; Buddemeier, R.W.

    1988-06-27

    The salinity, depth, quantity, and reliability of fresh groundwater resources on coral reef islands and coastlines are environmentally important parameters. Groundwater influences or controls the terrestrial flora, salinity, and nutrient levels in the near-shore benthic environment, the rate and nature of sediment diagenesis, and the density of human habitation. Data from a number of Indo-Pacific reef islands suggest that freshwater inventory is a function of rainfall and island dimensions. A numerical model (SUTRA) has been used to simulate the responses of atoll island groundwater to changes in recharge (precipitation), sea level, and loss of island area due to flooding. The model has been calibrated for Enjebi Island, Enewetak Atoll, where a moderately permeable, water-table aquifer overlies a high-permeability formation. Total freshwater inventory is a monotonic but nonlinear function of recharge. If recharge and island area are constant, rising sea level increases the inventory of fresh water by increasing the useful volume of the aquifer above the high-permeability zone. Flooding of land area reduces the total freshwater inventory approximately in proportion to the loss of recharge area. The most significant results of the model simulation, however, are the findings that the inventory of low-salinity water (and by extrapolation, potable water) is disproportionately sensitive to changes in recharge, island dimensions, or recharge. Island freshwater resources may therefore be unexpectedly vulnerable to climate change.

  9. Recharge Data for Hawaii Island

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Recharge data for Hawaii Island in shapefile format. The data are from the following sources: Whittier, R.B and A.I. El-Kadi. 2014. Human Health and Environmental Risk Ranking of On-Site Sewage Disposal systems for the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final, Prepared for Hawaii Dept. of Health, Safe Drinking Water Branch by the University of Hawaii, Dept. of Geology and Geophysics. Oki, D. S. 1999. Geohydrology and Numerical Simulation of the Ground-Water Flow System of Kona, Island of Hawaii. U.S. Water-Resources Investigation Report: 99-4073. Oki, D. S. 2002. Reassessment of Ground-water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii. U.S. Geological Survey Water-Resources Investigation report 02-4006.

  10. Relationship between Overpressure and the Formation of Hydrocarbon-Rich Solitary Waves during Sedimentary Basin Diagenesis: A Case Study of the Eugene Island 330 Field in the Gulf of Mexico Basin

    NASA Astrophysics Data System (ADS)

    Joshi, A.; Appold, M. S.; Nunn, J. A.

    2011-12-01

    Hydrocarbons in shallow (< 1 km depth) Pleistocene sand reservoirs of the Eugene Island 330 field in the northern Gulf of Mexico basin are thought to have originated from Early Tertiary source sediments at depths of about 4.5 km. Despite the low permeability of the intervening sediments, hydrocarbons appear to have moved rapidly through these sediments, most likely as discrete pressure pulses (solitary waves) along the Red growth fault system. The purpose of the present research was to evaluate the mechanics of solitary wave formation and movement during sedimentation, diagenesis, and source rock maturation in the Eugene Island hydrocarbon field. A detailed two-dimensional model coupling sedimentation, compaction, hydrocarbon generation, heat transport, and multi-phase fluid flow predicted overpressures of 50 MPa by 0.5 Ma in the hydrocarbon source sediments, with about 93% of the overpressure caused by compaction disequilibrium and the remainder by hydrocarbon generation. Movement along the Red growth fault was rapid enough to cause a pressure decrease of several MPa from the upthrown block to the downthrown block, consistent with field observations. The average pressure generation rate at the base of the Red fault during the period of hydrocarbon formation was predicted to be 9.6x10-7 Pa/s. However, for the most likely values of fault permeability, basal heat flow, and organic carbon content of the source rocks, too little hydrocarbon was able to migrate along the Red fault by conventional Darcian flow and accumulate in the Pleistocene reservoirs relative to field observations. Only when the permeability of the shale-bounded portions of the Red fault was increased by an order of magnitude, the basal heat flow was increased from 60 to 70 mW/m2, and the organic carbon content of the source rocks was increased from 5% to 10% was hydrocarbon transport by conventional Darcian flow through the Red fault great enough to accumulate in the reservoirs in amounts

  11. Reviving Antibiotics: Efflux Pump Inhibitors That Interact with AcrA, a Membrane Fusion Protein of the AcrAB-TolC Multidrug Efflux Pump

    SciTech Connect

    Abdali, Narges; Parks, Jerry M.; Haynes, Keith M.; Chaney, Julie L.; Green, Adam T.; Wolloscheck, David; Walker, John K.; Rybenkov, Valentin V.; Baudry, Jerome; Smith, Jeremy C.; Zgurskaya, Helen I.

    2016-10-21

    Antibiotic resistance is a major threat to human welfare. Inhibitors of multidrug efflux pumps (EPIs) are promising alternative therapeutics that could revive activities of antibiotics and reduce bacterial virulence. Identification of new druggable sites for inhibition is critical for developing effective EPIs, especially in light of constantly emerging resistance. We describe new EPIs that interact with and possibly inhibit the function of periplasmic membrane fusion proteins, critical components of efflux pumps that are responsible for the activation of the transporter and the recruitment of the outer-membrane channel. The discovered EPIs bind to AcrA, a component of the prototypical AcrAB-TolC pump, change its structure in vivo, inhibit efflux of fluorescent probes and potentiate the activities of antibiotics in Escherichia coli cells. These findings expand the chemical and mechanistic diversity of EPIs, suggest the mechanism for regulation of the efflux pump assembly and activity, and provide a promising path for reviving the activities of antibiotics in resistant bacteria.

  12. Reviving Antibiotics: Efflux Pump Inhibitors That Interact with AcrA, a Membrane Fusion Protein of the AcrAB-TolC Multidrug Efflux Pump

    DOE PAGES

    Abdali, Narges; Parks, Jerry M.; Haynes, Keith M.; ...

    2016-10-21

    Antibiotic resistance is a major threat to human welfare. Inhibitors of multidrug efflux pumps (EPIs) are promising alternative therapeutics that could revive activities of antibiotics and reduce bacterial virulence. Identification of new druggable sites for inhibition is critical for developing effective EPIs, especially in light of constantly emerging resistance. We describe new EPIs that interact with and possibly inhibit the function of periplasmic membrane fusion proteins, critical components of efflux pumps that are responsible for the activation of the transporter and the recruitment of the outer-membrane channel. The discovered EPIs bind to AcrA, a component of the prototypical AcrAB-TolC pump,more » change its structure in vivo, inhibit efflux of fluorescent probes and potentiate the activities of antibiotics in Escherichia coli cells. These findings expand the chemical and mechanistic diversity of EPIs, suggest the mechanism for regulation of the efflux pump assembly and activity, and provide a promising path for reviving the activities of antibiotics in resistant bacteria.« less

  13. Expression of the AcrAB Components of the AcrAB-TolC Multidrug Efflux Pump of Yersinia enterocolitica Is Subject to Dual Regulation by OmpR.

    PubMed

    Raczkowska, Adrianna; Trzos, Joanna; Lewandowska, Olga; Nieckarz, Marta; Brzostek, Katarzyna

    2015-01-01

    OmpR is a transcriptional regulator implicated in the control of various cellular processes and functions in Enterobacteriaceae. This study was undertaken to identify genes comprising the OmpR regulon in the human gastrointestinal pathogen Yersinia enterocolitica. Derivatives of an ompR-negative strain with random transposon insertions creating transcriptional fusions with the reporter gene lacZ were isolated. These were supplied with the wild-type ompR allele in trans and then screened for OmpR-dependent changes in β-galactosidase activity. Using this strategy, five insertions in genes/operons positively regulated by OmpR and two insertions in genes negatively regulated by this protein were identified. Genetic analysis of one of these fusion strains revealed that the gene acrR, encoding transcriptional repressor AcrR is negatively regulated by OmpR. Differential analysis of membrane proteins by SDS-PAGE followed by mass spectrometry identified the protein AcrB, a component of the AcrAB-TolC multidrug efflux pump, as being positively regulated by OmpR. Analysis of the activity of the acrR and acrAB promoters using gfp fusions confirmed their OmpR-dependent repression and activation, respectively. The identification of putative OmpR-binding sites and electrophoretic mobility shift assays confirmed that this regulator binds specifically to both promoter regions with different affinity. Examination of the activity of the acrR and acrAB promoters after the exposure of cells to different chemicals showed that bile salts can act as an OmpR-independent inducer. Taken together, our findings suggest that OmpR positively controls the expression of the AcrAB-TolC efflux pump involved in the adaptive response of Y. enterocolitica O:9 to different chemical stressors, thus conferring an advantage in particular ecological niches.

  14. Geothermal resources of Sao Miguel Island, Azores, Portugal

    SciTech Connect

    Duffield, W.A.; Muffler, L.J.P.

    1984-01-01

    Geothermal studies were carried out on the island of Sao Miguel, Azores to characterize the nature of the resource, to estimate its magnitude, and to identify target areas toward which exploration and developmental drilling might be directed. The main geothermal resource areas are Furnas, Agua de Pau, and Sete Cidades, three Quaternary silicic volcanic centers characterized by summit calderas beneath which magmatic heat sources provide thermal energy to overlying hydrothermal convection systems. For each of the systems, the studies have defined the size of the system, the subsurface temperature, the thermodynamic state of fluid in the system, the chemical composition of the fluid, and permeable parts of the system. 8 figs. (ACR)

  15. Geochemical and Sr-Nd isotope variations within Cretaceous continental flood-basalt suites of the Canadian High Arctic, with a focus on the Hassel Formation basalts of northeast Ellesmere Island

    NASA Astrophysics Data System (ADS)

    Estrada, Solveig

    2015-11-01

    Early- to mid-Cretaceous flood-basalt suites of the northeast Canadian High Arctic assigned to a High Arctic Large Igneous Province (HALIP) were studied for their whole-rock geochemistry and Sr-Nd isotopes. Data from basalt flows within the upper Albian to lower Cenomanian Hassel Formation of northeast Ellesmere Island are compared with former published data and new inductively coupled plasma mass spectrometry data of the stratigraphic equivalent Strand Fiord basalts and the older, late Hauterivian to Aptian Isachsen basalts from Axel Heiberg Island. The transitional to mildly alkaline aphyric Hassel basalts, with ocean island basalt (OIB)-like geochemical signatures in parts, have an Ar-Ar whole-rock age of on average 96.4 ± 1.6 Ma. They represent two geochemically different flow units without a fractional crystallization relationship: the high-phosphorous (HP) and low-phosphorous (LP) basalts. The Hassel HP basalts differ from the LP basalts by additionally higher Ba, K, Rb, Th and LREE contents, a pronounced positive Eu anomaly (Eu/Eu* = 1.74-1.76), as well as lower Ta, Nb, Zr and Hf concentrations. The Nd and Sr isotope ratios of the Hassel HP basalts [ ɛ Nd( t) of -1.3 to -1.4, 87Sr/86Sr( t) of 0.70706-0.70707] and the LP basalts [ ɛ Nd( t) of 4.5-4.9, 87Sr/86Sr( t) of 0.7038-0.7040] indicate an origin from different mantle sources. The geochemically similar tholeiitic Isachsen (ca. 130-113 Ma) and Strand Fiord basalts (ca. 105-95 Ma) are also incompatible element enriched relative to the primitive mantle, however, with negative Sr-P anomalies as well as partially negative K, Ta and Nb anomalies. In terms of incompatible element ratios (Zr/Nb, Nb/Th), several mantle components are involved in the formation of the flood-basalt suites: a component with primitive mantle composition, an OIB-like component (probably subducted and recycled oceanic crust) and an enriched lithospheric component. The latter component, probably metasomatized subcontinental

  16. An osprey at home in the Merritt Island National Wildlife Refuge

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A Rough-legged Hawk fans its wings as it gently lands in a tree in the Merritt Island National Wildlife Refuge. This type of hawk is rarely seen in Florida, ranging from northern Alaska through Manitoba and Newfoundland and wintering from California east to Virginia. The 92,000-acre refuge, which shares a boundary with the Kennedy Space Center, is habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

  17. An osprey at home in the Merritt Island National Wildlife Refuge

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A Rough-legged hawk stares at the landscape from a perch in a tree in the Merritt Island National Wildlife Refuge. This type of hawk is rarely seen in Florida, ranging from northern Alaska through Manitoba and Newfoundland and wintering from California east to Virginia. The 92,000-acre refuge, which shares a boundary with the Kennedy Space Center, is habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

  18. The Challenges from Extreme Climate Events for Sustainable Development in Amazonia: the Acre State Experience

    NASA Astrophysics Data System (ADS)

    Araújo, M. D. N. M.

    2015-12-01

    In the past ten years Acre State, located in Brazil´s southwestern Amazonia, has confronted sequential and severe extreme events in the form of droughts and floods. In particular, the droughts and forest fires of 2005 and 2010, the 2012 flood within Acre, the 2014 flood of the Madeira River which isolated Acre for two months from southern Brazil, and the most severe flooding throughout the state in 2015 shook the resilience of Acrean society. The accumulated costs of these events since 2005 have exceeded 300 million dollars. For the last 17 years, successive state administrations have been implementing a socio-environmental model of development that strives to link sustainable economic production with environmental conservation, particularly for small communities. In this context, extreme climate events have interfered significantly with this model, increasing the risks of failure. The impacts caused by these events on development in the state have been exacerbated by: a) limitations in monitoring; b) extreme events outside of Acre territory (Madeira River Flood) affecting transportation systems; c) absence of reliable information for decision-making; and d) bureaucratic and judicial impediments. Our experience in these events have led to the following needs for scientific input to reduce the risk of disasters: 1) better monitoring and forecasting of deforestation, fires, and hydro-meteorological variables; 2) ways to increase risk perception in communities; 3) approaches to involve more effectively local and regional populations in the response to disasters; 4) more accurate measurements of the economic and social damages caused by these disasters. We must improve adaptation to and mitigation of current and future extreme climate events and implement a robust civil defense, adequate to these new challenges.

  19. Improving olefin tolerance and production in E. coli using native and evolved AcrB.

    PubMed

    Mingardon, Florence; Clement, Camille; Hirano, Kathleen; Nhan, Melissa; Luning, Eric G; Chanal, Angelique; Mukhopadhyay, Aindrila

    2015-05-01

    Microorganisms can be engineered for the production of chemicals utilized in the polymer industry. However many such target compounds inhibit microbial growth and might correspondingly limit production levels. Here, we focus on compounds that are precursors to bioplastics, specifically styrene and representative alpha-olefins; 1-hexene, 1-octene, and 1-nonene. We evaluated the role of the Escherichia coli efflux pump, AcrAB-TolC, in enhancing tolerance towards these olefin compounds. AcrAB-TolC is involved in the tolerance towards all four compounds in E. coli. Both styrene and 1-hexene are highly toxic to E. coli. Styrene is a model plastics precursor with an established route for production in E. coli (McKenna and Nielsen, 2011). Though our data indicates that AcrAB-TolC is important for its optimal production, we observed a strong negative selection against the production of styrene in E. coli. Thus we used 1-hexene as a model compound to implement a directed evolution strategy to further improve the tolerance phenotype towards this alpha-olefin. We focused on optimization of AcrB, the inner membrane domain known to be responsible for substrate binding, and found several mutations (A279T, Q584R, F617L, L822P, F927S, and F1033Y) that resulted in improved tolerance. Several of these mutations could also be combined in a synergistic manner. Our study shows efflux pumps to be an important mechanism in host engineering for olefins, and one that can be further improved using strategies such as directed evolution, to increase tolerance and potentially production.

  20. Improving olefin tolerance and production in E. coli using native and evolved AcrB

    DOE PAGES

    Mingardon, Florence; Clement, Camille; Hirano, Kathleen; ...

    2015-01-20

    Microorganisms can be engineered for the production of chemicals utilized in the polymer industry. However many such target compounds inhibit microbial growth and might correspondingly limit production levels. Here, we focus on compounds that are precursors to bioplastics, specifically styrene and representative alpha-olefins; 1-hexene, 1-octene, and 1-nonene. We evaluated the role of the Escherichia coli efflux pump, AcrAB-TolC, in enhancing tolerance towards these olefin compounds. AcrAB-TolC is involved in the tolerance towards all four compounds in E. coli. Both styrene and 1-hexene are highly toxic to E. coli. Styrene is a model plastics precursor with an established route for productionmore » in E. coli (McKenna and Nielsen, 2011). Though our data indicates that AcrAB-TolC is important for its optimal production, we observed a strong negative selection against the production of styrene in E. coli. Thus we used 1-hexene as a model compound to implement a directed evolution strategy to further improve the tolerance phenotype towards this alpha-olefin. We focused on optimization of AcrB, the inner membrane domain known to be responsible for substrate binding, and found several mutations (A279T, Q584R, F617L, L822P, F927S, and F1033Y) that resulted in improved tolerance. Several of these mutations could also be combined in a synergistic manner. Our study shows efflux pumps to be an important mechanism in host engineering for olefins, and one that can be further improved using strategies such as directed evolution, to increase tolerance and potentially production.« less

  1. Regulation of the AcrAB multidrug efflux pump in Salmonella enterica serovar Typhimurium in response to indole and paraquat.

    PubMed

    Nikaido, Eiji; Shirosaka, Ikue; Yamaguchi, Akihito; Nishino, Kunihiko

    2011-03-01

    Salmonella enterica serovar Typhimurium has at least nine multidrug efflux pumps. Among these, AcrAB is constitutively expressed and is the most efficient, playing a role in both drug resistance and virulence. The acrAB locus is induced by indole, Escherichia coli-conditioned medium, and bile salts. This induction is dependent on RamA through the binding sequence in the upstream region of acrA that binds RamA. In the present study, we made a detailed investigation of the ramA and acrAB induction mechanisms in Salmonella in response to indole, a biological oxidant for bacteria. We found that acrAB and ramA induction in response to indole is dependent on RamR. However, the cysteine residues of RamR do not play a role in the induction of ramA in response to indole, and the oxidative effect of indole is therefore not related to ramA induction via RamR. Furthermore, we showed that paraquat, a superoxide generator, induces acrAB but not ramA. We further discovered that the mechanism of acrAB induction in response to paraquat is dependent on SoxS. The data indicate that there are at least two independent induction pathways for acrAB in response to extracellular signals such as indole and paraquat. We propose that Salmonella utilizes these regulators for acrAB induction in response to extracellular signals in order to adapt itself to environmental conditions.

  2. The subtype I-F CRISPR-Cas system influences pathogenicity island retention in Pectobacterium atrosepticum via crRNA generation and Csy complex formation.

    PubMed

    Richter, Corinna; Fineran, Peter C

    2013-12-01

    CRISPR (clustered regularly interspaced short palindromic repeats) arrays and Cas (CRISPR-associated) proteins confer acquired resistance against mobile genetic elements in a wide range of bacteria and archaea. The phytopathogen Pectobacterium atrosepticum SCRI1043 encodes a single subtype I-F CRISPR system, which is composed of three CRISPR arrays and the cas operon encoding Cas1, Cas3 (a Cas2-Cas3 fusion), Csy1, Csy2, Csy3 and Cas6f (Csy4). The CRISPR arrays are transcribed into pre-crRNA (CRISPR RNA) and then processed by Cas6f to generate crRNAs. Furthermore, the formation of Cas protein complexes has been implicated in both the interference and acquisition stages of defence. In the present paper, we discuss the development of tightly controlled 'programmable' CRISPR arrays as tools to investigate CRISPR-Cas function and the effects of chromosomal targeting. Finally, we address how chromosomal targeting by CRISPR-Cas can cause large-scale genome deletions, which can ultimately influence bacterial evolution and pathogenicity.

  3. Multidrug binding properties of the AcrB efflux pump characterized by molecular dynamics simulations

    PubMed Central

    Vargiu, Attilio V.; Nikaido, Hiroshi

    2012-01-01

    Multidrug resistance in Gram-negative bacteria, to which multidrug efflux pumps such as the AcrB transporter makes a major contribution, is becoming a major public health problem. Unfortunately only a few compounds have been cocrystallized with AcrB, and thus computational approaches are essential in elucidating the interaction between diverse ligands and the pump protein. We used molecular dynamics simulation to examine the binding of nine substrates, two inhibitors, and two nonsubstrates to the distal binding pocket of AcrB, identified earlier by X-ray crystallography. This approach gave us more realistic views of the binding than the previously used docking approach, as the explicit water molecules contributed to the process and the flexible binding site was often seen to undergo large structural changes. We analyzed the interaction in detail in terms of the binding energy, hydrophobic surface-matching, and the residues involved in the process. We found that all substrates tested bound to the pocket, whereas the binding to this site was not preferred for the nonsubstrates. Interestingly, both inhibitors [Phe-Arg-β-naphthylamide and 1-(1-naphtylmethyl)-piperazine] tended to move out of the pocket at least partially, getting into contact with a glycine-rich loop that separates the distal pocket from the more proximal region of the protein and is thought to control the access of substrates to the distal pocket. PMID:23175790

  4. Discos de acresção em sistemas Be-X

    NASA Astrophysics Data System (ADS)

    Lopes de Oliveira, R.; Janot-Pacheco, E.

    2003-08-01

    Alguns fenômenos de outbursts em Be-X sugerem a existência, mesmo que temporária, de um disco de acresção quando da passagem do objeto compacto pelo periastro orbital. Neste trabalho avaliamos a possibilidade de formação do disco de acresção em sistemas Be+estrela de neutrons e Be+anã branca, e a influência da excentricidade orbital na ocorrência deste fenômeno. Utilizamos a expressão analítica para o momento angular específico da matéria constituinte de um meio em expansão lenta, como é o caso do disco circunstelar das estrelas Be, proposta por Wang(1981), sob a condição básica de que o raio de circularização deva ser maior do que o raio de Alfvén. Concluímos que existe um limite para o período orbital do sistema acima do qual não é possível a formação do disco de acresção, e que este valor aumenta para sistemas com excentricidade orbital maior.

  5. Statistical thermodynamics for functionally rotating mechanism of the multidrug efflux transporter AcrB.

    PubMed

    Mishima, Hirokazu; Oshima, Hiraku; Yasuda, Satoshi; Kinoshita, Masahiro

    2015-02-26

    AcrB, a homotrimer, is the pivotal part of a multidrug efflux pump. A "functionally rotating" picture has been proposed for the drug transport by AcrB, but its mechanism remains unresolved. Here, we investigate the energetics of the whole functional rotation cycle using our theoretical methods. We find that the packing efficiency of AcrB is ununiform, and this ununiformity plays imperative roles primarily through the solvent-entropy effect. When a proton binds to or dissociates from a protomer, the packing properties of this protomer and its two interfaces are perturbed overall in the direction that the solvent translational entropy is lowered. The packing properties of the other two protomers are then reorganized with the recovery or maintenance of closely packed interfaces, so that the solvent-entropy loss can be compensated. The functional structural change by an isolated protomer would cause a seriously large free-energy increase. By forming a trimer, any free-energy increase caused by a protomer is always canceled out by the free-energy decrease brought by the other two protomers via the mechanism mentioned above. The functional structural rotation is thus accomplished using the free-energy decrease arising from the transfer of only a single proton per cycle. The similarities to F1-ATPase are also discussed.

  6. Involvement of the AcrAB-TolC Efflux Pump in the Resistance, Fitness, and Virulence of Enterobacter cloacae

    PubMed Central

    Pérez, Astrid; Poza, Margarita; Fernández, Ana; del Carmen Fernández, Maria; Mallo, Susana; Merino, María; Rumbo-Feal, Soraya; Cabral, María P.

    2012-01-01

    Multidrug efflux pumps have emerged as important mechanisms of antimicrobial resistance in bacterial pathogens. In order to cause infection, pathogenic bacteria require mechanisms to avoid the effects of host-produced compounds, and express efflux pumps may accomplish this task. In this study, we evaluated the effect of the inactivation of AcrAB-TolC on antimicrobial resistance, fitness, and virulence in Enterobacter cloacae, an opportunistic pathogen usually involved in nosocomial infections. Two different clinical isolates of E. cloacae were used, EcDC64 (multidrug resistance overexpressing the AcrAB-TolC efflux pump) and Jc194 (basal AcrAB-TolC expression). The acrA and tolC genes were deleted in strains EcDC64 and Jc194 to produce, respectively, EcΔacrA and EcΔtolC and JcΔacrA and JcΔtolC knockout (KO) derivatives. Antibiotic susceptibility testing was performed with all isolates, and we discovered that these mechanisms are involved in the resistance of E. cloacae to several antibiotics. Competition experiments were also performed with wild-type and isogenic KO strains. The competition index (CI), defined as the mutant/wild-type ratio, revealed that the acrA and tolC genes both affect the fitness of E. cloacae, as fitness was clearly reduced in the acrA and tolC KO strains. The median CI values obtained in vitro and in vivo were, respectively, 0.42 and 0.3 for EcDC64/EcΔacrA, 0.24 and 0.38 for EcDC64/EcΔtolC, 0.15 and 0.11 for Jc194/JcΔacrA, and 0.38 and 0.39 for Jc194/JcΔtolC. Use of an intraperitoneal mouse model of systemic infection revealed reduced virulence in both E. cloacae clinical strains when either the acrA or tolC gene was inactivated. In conclusion, the structural components of the AcrAB-TolC efflux pump appear to play a role in antibiotic resistance as well as environmental adaptation and host virulence in clinical isolates of E. cloacae. PMID:22290971

  7. Involvement of the AcrAB-TolC efflux pump in the resistance, fitness, and virulence of Enterobacter cloacae.

    PubMed

    Pérez, Astrid; Poza, Margarita; Fernández, Ana; Fernández, Maria del Carmen; Mallo, Susana; Merino, María; Rumbo-Feal, Soraya; Cabral, María P; Bou, Germán

    2012-04-01

    Multidrug efflux pumps have emerged as important mechanisms of antimicrobial resistance in bacterial pathogens. In order to cause infection, pathogenic bacteria require mechanisms to avoid the effects of host-produced compounds, and express efflux pumps may accomplish this task. In this study, we evaluated the effect of the inactivation of AcrAB-TolC on antimicrobial resistance, fitness, and virulence in Enterobacter cloacae, an opportunistic pathogen usually involved in nosocomial infections. Two different clinical isolates of E. cloacae were used, EcDC64 (multidrug resistance overexpressing the AcrAB-TolC efflux pump) and Jc194 (basal AcrAB-TolC expression). The acrA and tolC genes were deleted in strains EcDC64 and Jc194 to produce, respectively, EcΔacrA and EcΔtolC and JcΔacrA and JcΔtolC knockout (KO) derivatives. Antibiotic susceptibility testing was performed with all isolates, and we discovered that these mechanisms are involved in the resistance of E. cloacae to several antibiotics. Competition experiments were also performed with wild-type and isogenic KO strains. The competition index (CI), defined as the mutant/wild-type ratio, revealed that the acrA and tolC genes both affect the fitness of E. cloacae, as fitness was clearly reduced in the acrA and tolC KO strains. The median CI values obtained in vitro and in vivo were, respectively, 0.42 and 0.3 for EcDC64/EcΔacrA, 0.24 and 0.38 for EcDC64/EcΔtolC, 0.15 and 0.11 for Jc194/JcΔacrA, and 0.38 and 0.39 for Jc194/JcΔtolC. Use of an intraperitoneal mouse model of systemic infection revealed reduced virulence in both E. cloacae clinical strains when either the acrA or tolC gene was inactivated. In conclusion, the structural components of the AcrAB-TolC efflux pump appear to play a role in antibiotic resistance as well as environmental adaptation and host virulence in clinical isolates of E. cloacae.

  8. 75 FR 20398 - The ACRS Subcommittee on Planning and Procedures will hold a meeting on May 5, 2010, in Room T...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Planning and Procedures The ACRS Subcommittee on Planning and Procedures will hold a meeting on May 5, 2010, in Room...

  9. Bikeability and methodological issues using the active commuting route environment scale (ACRES) in a metropolitan setting

    PubMed Central

    2011-01-01

    Background Route environments can positively influence people's active commuting and thereby contribute to public health. The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters' perceptions of their route environments. However, bicycle commuters represent a small portion of the population in many cities and thus are difficult to study using population-based material. Therefore, the aim of this study is to expand the state of knowledge concerning the criterion-related validity of the ACRES and the representativity using an advertisement-recruited sample. Furthermore, by comparing commuting route environment profiles of inner urban and suburban areas, we provide a novel basis for understanding the relationship between environment and bikeability. Methods Bicycle commuters from Greater Stockholm, Sweden, advertisement- (n = 1379) and street-recruited (n = 93), responded to the ACRES. Traffic planning and environmental experts from the Municipality of Stockholm (n = 24) responded to a modified version of the ACRES. The criterion-related validity assessments were based on whether or not differences between the inner urban and the suburban route environments, as indicated by the experts and by four existing objective measurements, were reflected by differences in perceptions of these environments. Comparisons of ratings between advertisement- and street-recruited participants were used for the assessments of representativity. Finally, ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Results Differences in ratings of the inner urban and suburban route environments by the advertisement-recruited participants were in accord with the existing objective measurements and corresponded reasonably well with those of the experts. Overall, there was a reasonably good correspondence between the advertisement- and street-recruited participants' ratings. Distinct differences in

  10. Evapotranspiration Cover for the 92-Acre Area Retired Mixed Waste Pits:Interim CQA Report

    SciTech Connect

    The Delphi Groupe, Inc., and J. A. Cesare and Associates, Inc.

    2011-06-20

    This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. This Interim Construction Quality Assurance (CQA) Report is for the 92-Acre Evapotranspiration Cover, Area 5 Waste Management Division (WMD) Retired Mixed Waste Pits, Nevada National Security Site, Nevada for the period of January 20, 2011 to May 12, 2011. Construction was approved by the Nevada Division of Environmental Protection (NDEP) under the Approval of Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for Corrective Action Unit (CAU) 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada, on January 6, 2011, pursuant to Subpart XII.8a of the Federal Facility Agreement and Consent Order. The project is located in Area 5 of the Radioactive Waste Management Complex (RWMC) at the Nevada National Security Site (NNSS), formerly known as the Nevada Test Site, located in southern Nevada, approximately 65 miles northwest of Las Vegas, Nevada, in Nye County. The project site, in Area 5, is located in a topographically closed basin approximately 14 additional miles north of Mercury Nevada, in the north-central part of Frenchman Flat. The Area 5 RWMS uses engineered shallow-land burial cells to dispose of packaged waste. The 92-Acre Area encompasses the southern portion of the Area 5 RWMS, which has been designated for the first final closure operations. This area contains 13 Greater Confinement Disposal (GCD) boreholes, 16 narrow trenches, and 9 broader pits. With the exception of two active pits (P03 and P06), all trenches and pits in the 92-Acre Area had operational covers approximately 2.4 meters thick, at a minimum, in most areas when this project began. The units within the 92-Acre Area are grouped into the following six informal categories based on physical location

  11. Oxygen Isotope Variation Within a Quaternary, Caldera-forming, Phonolitic Eruptive Sequence; the Diego Hernández Formation, Tenerife, Canary Islands (Spain)

    NASA Astrophysics Data System (ADS)

    Hickes, H. J.; Larson, P. B.; Wolff, J. A.; Olin, P.

    2003-12-01

    Much of the work done on oxygen isotopes in volcanic rocks has been based on analyses of whole rock or multiple crystal aliquots, inherently discounting the importance of heterogeneity. Recently, due to advances in technology and the recognition of small-scale chemical disequilibria in magmatic systems, it has proven valuable to measure variations among individual grains to examine the evolution of these systems. Here, we present the results of both single and multi-crystal feldspar oxygen isotope analyses (1σ < 0.1 ‰ ) from phonolitic eruptive units of the Diego Hernández Formation (DHF) as part of an on-going study of the evolution of the Las Cañadas caldera complex on Tenerife. δ 18O (VSMOW) values of feldspar range from 4.7 to 6.7 ‰ (slightly lower than previously reported) and show a positive correlation with average crystal size (mg) in units that display a range of oxygen isotope values. For example, one unit shows a linear variation of feldspar δ 18O values that range from 4.7 to 6.4 ‰ , and these ratios are positively correlated with average phenocryst size over a range of 0.7 to 3.6 mg. Overall, intra-unit feldspar δ 18O values vary by as much as ˜2 ‰ and are lower than those predicted by fractionation of a basanitic parental magma. Additionally, δ 18O values show no coherent relationship with incompatible trace element abundances, an indication that the oxygen isotopic ratios are being controlled by neither fractionation nor recharge of the system by basaltic injections. However, the largest variation in oxygen isotope ratios is found in the most differentiated units, consistent with earlier suggestions that the most highly evolved phonolites may contain a component of hydrothermally-altered wall rock. We propose that oxygen isotope variation in Tenerife phonolites is being controlled by variable amounts of assimilation of hydrothermally-altered syenite country rock (δ 18O 0.1 - 5.8 ‰ ) and that timescales between assimilation and

  12. Hydrodynamic Modeling Analysis for Leque Island and zis a ba Restoration Feasibility Study

    SciTech Connect

    Whiting, Jonathan M.; Khangaonkar, Tarang

    2015-01-31

    Ducks Unlimited, Inc. in collaboration with Washington State Department of Fish and Wildlife (WDFW), and Stillaguamish Tribe of Indians have proposed the restoration of Leque Island and zis a ba (formerly Matterand) sites near the mouth of Old Stillaguamish River Channel in Port Susan Bay, Washington. The Leque Island site, which is owned by WDFW, consists of nearly 253 acres of land south of Highway 532 that is currently behind a perimeter dike. The 90-acres zis a ba site, also shielded by dikes along the shoreline, is located just upstream of Leque Island and is owned by Stillaguamish Tribes. The proposed actions consider the removal or modification of perimeter dikes at both locations to allow estuarine functions to be restored. The overall objective of the proposed projects is to remove the dike barriers to 1) provide connectivity and access between the tidal river channel and the restoration site for use by juvenile migrating salmon and 2) create a self-sustaining tidal marsh habitat. Ducks Unlimited engaged Pacific Northwest National Laboratory (PNNL) to develop a three-dimensional hydrodynamic model of the Port Susan Bay, Skagit Bay, and the interconnecting Leque Island region for use in support of the feasibility assessment for the Leque Island and zis a ba restoration projects. The objective of this modeling-based feasibility assessment is to evaluate the performance of proposed restoration actions in terms of achieving habitat goals while assessing the potential hydraulic and sediment transport impacts to the site and surrounding parcels of land.

  13. Interaction of bootstrap-current-driven magnetic islands

    SciTech Connect

    Hegna, C.C.; Callen, J.D.

    1991-10-01

    The formation and interaction of fluctuating neoclassical pressure gradient driven magnetic islands is examined. The interaction of magnetic islands produces a stochastic region around the separatrices of the islands. This interaction causes the island pressure profile to be broadened, reducing the island bootstrap current and drive for the magnetic island. A model is presented that describes the magnetic topology as a bath of interacting magnetic islands with low to medium poloidal mode number (m {congruent} 3{minus}30). The islands grow by the bootstrap current effect and damp due to the flattening of the pressure profile near the island separatrix caused by the interaction of the magnetic islands. The effect of this sporadic growth and decay of the islands ( magnetic bubbling'') is not normally addressed in theories of plasma transport due to magnetic fluctuations. The nature of the transport differs from statistical approaches to magnetic turbulence since the radial step size of the plasma transport is now given by the characteristic island width. This model suggests that tokamak experiments have relatively short-lived, coherent, long wavelength magnetic oscillations present in the steep pressure-gradient regions of the plasma. 42 refs.

  14. Radiology in 2022: challenges and opportunities in the coming decade-proceedings of the 12th Annual ACR Forum.

    PubMed

    Krishnaraj, Arun; Weinreb, Jeffrey C; Ellenbogen, Paul H; Patti, John A; Hillman, Bruce J

    2013-01-01

    The 2012 ACR Forum focused on the anticipated challenges and opportunities facing radiology in the next 10 years, centered on the themes of health care reform, future payment models, research and innovation, patient-centered radiology, and information management. The recommendations generated from the forum seek to inform ACR leadership on the best strategies to pursue to ensure the continued success of the profession in the coming decade.

  15. Molecular Mechanism of MBX2319 Inhibition of Escherichia coli AcrB Multidrug Efflux Pump and Comparison with Other Inhibitors

    PubMed Central

    Vargiu, Attilio V.; Ruggerone, Paolo; Opperman, Timothy J.; Nguyen, Son T.

    2014-01-01

    Efflux pumps of the resistance nodulation division (RND) superfamily, such as AcrB, make a major contribution to multidrug resistance in Gram-negative bacteria. The development of inhibitors of the RND pumps would improve the efficacy of current and next-generation antibiotics. To date, however, only one inhibitor has been cocrystallized with AcrB. Thus, in silico structure-based analysis is essential for elucidating the interaction between other inhibitors and the efflux pumps. In this work, we used computer docking and molecular dynamics simulations to study the interaction between AcrB and the compound MBX2319, a novel pyranopyridine efflux pump inhibitor with potent activity against RND efflux pumps of Enterobacteriaceae species, as well as other known inhibitors (D13-9001, 1-[1-naphthylmethyl]-piperazine, and phenylalanylarginine-β-naphthylamide) and the binding of doxorubicin to the efflux-defective F610A variant of AcrB. We also analyzed the binding of a substrate, minocycline, for comparison. Our results show that MBX2319 binds very tightly to the lower part of the distal pocket in the B protomer of AcrB, strongly interacting with the phenylalanines lining the hydrophobic trap, where the hydrophobic portion of D13-9001 was found to bind by X-ray crystallography. Additionally, MBX2319 binds to AcrB in a manner that is similar to the way in which doxorubicin binds to the F610A variant of AcrB. In contrast, 1-(1-naphthylmethyl)-piperazine and phenylalanylarginine-β-naphthylamide appear to bind to somewhat different areas of the distal pocket in the B protomer of AcrB than does MBX2319. However, all inhibitors (except D13-9001) appear to distort the structure of the distal pocket, impairing the proper binding of substrates. PMID:25114133

  16. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  17. Canary Island Archipelago

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This nearly vertical view of the Canary Archipelago (28.5N, 16.5W) shows five of the seven islands: Grand Canary, Tenerife, Gomera, Hierro and La Palma. The largest island in view is Tenerife. Island cloud wakes evident in this photo are the result of southerly winds giving rise to cloud banks on the lee side especially on Tenerife which has the highest volcanic peaks. Island water wakes and internal waves are also evident but not as apparent.

  18. Falkland Islands, UK

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view of the Falkland Islands (52.0S, 58.5W) was taken with a dual camera mount. Compare this scene with STS048-109-043 to analyze the unique properties of each film type. Seldom seen cloud free, the Falkland Islands lie off the southern coast of Argentina. The cold Falklands Ocean Current keeps the islands chilly, ideal for sheep herding and fishing, the two main industries. Colonies of seals and penguins also thrive on the islands.

  19. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  20. Avifauna: Turnover on Islands.

    PubMed

    Mayr, E

    1965-12-17

    The percentage of endemic species of birds on islands increases with island area at a double logarithmic rate. This relation is apparently due to extinction, which is more rapid the smaller the island. The turnover resulting from extinction and replacement appears to be far more rapid than hitherto suspected.

  1. Diomede Islands, Bering Straight

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations.

    The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. Wind resource assessment: San Nicolas Island, California

    SciTech Connect

    McKenna, E.; Olsen, T.L.

    1996-01-01

    San Nicolas Island (SNI) is the site of the Navy Range Instrumentation Test Site which relies on an isolated diesel-powered grid for its energy needs. The island is located in the Pacific Ocean 85 miles southwest of Los Angeles, California and 65 miles south of the Naval Air Weapons Station (NAWS), Point Mugu, California. SNI is situated on the continental shelf at latitude N33{degree}14` and longitude W119{degree}27`. It is approximately 9 miles long and 3.6 miles wide and encompasses an area of 13,370 acres of land owned by the Navy in fee title. Winds on San Nicolas are prevailingly northwest and are strong most of the year. The average wind speed is 7.2 m/s (14 knots) and seasonal variation is small. The windiest months, March through July, have wind speeds averaging 8.2 m/s (16 knots). The least windy months, August through February, have wind speeds averaging 6.2 m/s (12 knots).

  3. Characterization of AcrD, a Resistance-Nodulation-Cell Division-type multidrug efflux pump from the fire blight pathogen Erwinia amylovora

    PubMed Central

    2014-01-01

    Background Multidrug efflux pumps are membrane translocases that have the ability to extrude a variety of structurally unrelated compounds from the cell. AcrD, a resistance-nodulation-cell division (RND) transporter, was shown to be involved in efflux of highly hydrophilic aminoglycosides and a limited number of amphiphilic compounds in E. coli. Here, a homologue of AcrD in the plant pathogen and causal agent of fire blight disease Erwinia amylovora was identified. Results The substrate specificity of AcrD was studied by overexpression of the corresponding gene from a high-copy plasmid in E. amylovora Ea1189-3, which is hypersensitive to many drugs due to a deficiency of the major multidrug pump AcrB. AcrD mediated resistance to several amphiphilic compounds including clotrimazole and luteolin, two compounds hitherto not described as substrates of AcrD in enterobacteria. However, AcrD was not able to expel aminoglycosides. An acrD mutant exhibited full virulence on apple rootstock and immature pear fruits. RT-PCR analysis revealed an induction of acrD expression in infected apple tissue but not on pear fruits. Moreover, a direct binding of BaeR, the response regulator of the two-component regulatory system BaeSR, to the acrD promoter was observed as has already been shown in other enterobacteria. Conclusions AcrD from E. amylovora is involved in resistance to a limited number of amphiphilic compounds, but in contrast to AcrD of E. coli, it is not involved in resistance to aminoglycosides. The expression of acrD was up-regulated by addition of the substrates deoxycholate, naringenin, tetracycline and zinc. AcrD appears to be regulated by the BaeSR two-component system, an envelope stress signal transduction pathway. PMID:24443882

  4. Description of Trichophoromyia ruifreitasi, a new phlebotomine species (Diptera, Psychodidae) from Acre State, Brazilian Amazon

    PubMed Central

    de Oliveira, Arley Faria José; Teles, Carolina Bioni Garcia; Medeiros, Jansen Fernandes; Camargo, Luís Marcelo Aranha; Pessoa, Felipe Arley Costa

    2015-01-01

    Abstract Trichophoromyia ruifreitasi sp. n. is described as a new species of sand fly from the genus Trichophoromyia Barretto. This description is supported with illustrations and photographs that detail the morphological characteristics of male specimens collected in the municipality of Assis Brasil, Acre State, Brazilian Amazon. This species is similar to Trichophoromyia auraensis (Mangabeira), but the two species can be easily differentiated by the distribution of setae on their parameres, and by the presence of a dorsal lobe in the parameres of the new species. PMID:26487825

  5. Description of Trichophoromyia ruifreitasi, a new phlebotomine species (Diptera, Psychodidae) from Acre State, Brazilian Amazon.

    PubMed

    de Oliveira, Arley Faria José; Teles, Carolina Bioni Garcia; Medeiros, Jansen Fernandes; Camargo, Luís Marcelo Aranha; Pessoa, Felipe Arley Costa

    2015-01-01

    Trichophoromyia ruifreitasi sp. n. is described as a new species of sand fly from the genus Trichophoromyia Barretto. This description is supported with illustrations and photographs that detail the morphological characteristics of male specimens collected in the municipality of Assis Brasil, Acre State, Brazilian Amazon. This species is similar to Trichophoromyia auraensis (Mangabeira), but the two species can be easily differentiated by the distribution of setae on their parameres, and by the presence of a dorsal lobe in the parameres of the new species.

  6. Beyond Antimicrobial Resistance: Evidence for a Distinct Role of the AcrD Efflux Pump in Salmonella Biology

    PubMed Central

    Buckner, Michelle M. C.; La Ragione, Roberto M.; Newcombe, Jane; Dwyer, Daniel J.; Ivens, Alasdair

    2016-01-01

    ABSTRACT For over 20 years, bacterial multidrug resistance (MDR) efflux pumps have been studied because of their impact on resistance to antimicrobials. However, critical questions remain, including why produce efflux pumps under non-antimicrobial treatment conditions, and why have multiple pumps if their only purpose is antimicrobial efflux? Salmonella spp. possess five efflux pump families, including the resistance-nodulation-division (RND) efflux pumps. Notably, the RND efflux pump AcrD has a unique substrate profile, distinct from other Salmonella efflux pumps. Here we show that inactivation of acrD results in a profoundly altered transcriptome and modulation of pathways integral to Salmonella biology. The most significant transcriptome changes were central metabolism related, with additional changes observed in pathogenicity, environmental sensing, and stress response pathway expression. The extent of tricarboxylic acid cycle and fumarate metabolism expression changes led us to hypothesize that acrD inactivation may result in motility defects due to perturbation of metabolite concentrations, such as fumarate, for which a role in motility has been established. Despite minimal detectable changes in flagellar gene expression, we found that an acrD mutant Salmonella enterica serovar Typhimurium isolate was significantly impaired for swarming motility, which was restored by addition of fumarate. The acrD mutant outcompeted the wild type in fitness experiments. The results of these diverse experiments provide strong evidence that the AcrD efflux pump is not simply a redundant system providing response resilience, but also has distinct physiological functions. Together, these data indicate that the AcrD efflux pump has a significant and previously underappreciated impact on bacterial biology, despite only minor perturbations of antibiotic resistance profiles. PMID:27879336

  7. Beyond Antimicrobial Resistance: Evidence for a Distinct Role of the AcrD Efflux Pump in Salmonella Biology.

    PubMed

    Buckner, Michelle M C; Blair, Jessica M A; La Ragione, Roberto M; Newcombe, Jane; Dwyer, Daniel J; Ivens, Alasdair; Piddock, Laura J V

    2016-11-22

    For over 20 years, bacterial multidrug resistance (MDR) efflux pumps have been studied because of their impact on resistance to antimicrobials. However, critical questions remain, including why produce efflux pumps under non-antimicrobial treatment conditions, and why have multiple pumps if their only purpose is antimicrobial efflux? Salmonella spp. possess five efflux pump families, including the resistance-nodulation-division (RND) efflux pumps. Notably, the RND efflux pump AcrD has a unique substrate profile, distinct from other Salmonella efflux pumps. Here we show that inactivation of acrD results in a profoundly altered transcriptome and modulation of pathways integral to Salmonella biology. The most significant transcriptome changes were central metabolism related, with additional changes observed in pathogenicity, environmental sensing, and stress response pathway expression. The extent of tricarboxylic acid cycle and fumarate metabolism expression changes led us to hypothesize that acrD inactivation may result in motility defects due to perturbation of metabolite concentrations, such as fumarate, for which a role in motility has been established. Despite minimal detectable changes in flagellar gene expression, we found that an acrD mutant Salmonella enterica serovar Typhimurium isolate was significantly impaired for swarming motility, which was restored by addition of fumarate. The acrD mutant outcompeted the wild type in fitness experiments. The results of these diverse experiments provide strong evidence that the AcrD efflux pump is not simply a redundant system providing response resilience, but also has distinct physiological functions. Together, these data indicate that the AcrD efflux pump has a significant and previously underappreciated impact on bacterial biology, despite only minor perturbations of antibiotic resistance profiles.

  8. Hydrostratigraphy of Tree Island Cores from Water Conservation Area 3

    USGS Publications Warehouse

    McNeill, Donald F.; Cunningham, Kevin J.

    2003-01-01

    Cores and borehole-geophysical logs collected on and around two tree islands in Water Conservation Area 3 have been examined to develop a stratigraphic framework for these ecosystems. Especially important is the potential for the exchange of ground water and surface water within these features. The hydrostratigraphic results from this study document the lithologic nature of the foundation of the tree islands, the distribution of porous intervals, the potential for paleotopographic influence on their formation, and the importance of low-permeability, subaerial-exposure horizons on the vertical exchange of ground water and surface water. Figure 1. Location of Tree Islands 3AS3 and 3BS1. [larger image] Results from this hydrostratigraphic study indicate that subtle differences occur in lithofacies and topography between the on-island and off-island subsurface geologic records. Specifics are described herein. Firstly, at both tree-island sites, the top of the limestone bedrock is slightly elevated beneath the head of the tree islands relative to the off-island core sites and the tail of the tree islands, which suggests that bedrock 'highs' acted as 'seeds' for the development of the tree islands of this study and possibly many others. Secondly, examination of the recovered core and the caliper logs tentatively suggest that the elevated limestone beneath the tree islands may have a preferentially more porous framework relative to limestone beneath the adjacent areas, possibly providing a ground-water-to-surface-water connection that sustains the tree island system. Finally, because the elevation of the top of the limestone bedrock at the head of Tree Island 3AS3 is slightly higher than the surrounding upper surface of the peat, and because the wetland peats have a lower hydraulic conductivity than the limestone bedrock (Miami Limestone and Fort Thompson Formation), it is possible that there is a head difference between surface water of the wetlands and the ground water

  9. [Motorcycle accidents in the municipality of Rio Branco in the State of Acre: characterization and trends].

    PubMed

    Rocha, Greiciane da Silva; Schor, Néia

    2013-03-01

    The scope of this paper is to assess traffic accidents involving motorcycles, the victims involved and the increase in the fleet compared with other vehicles in Rio Branco, State of Acre. It is an epidemiological, descriptive and transversal study of accidents between 2005 and 2008 recorded by the Acre State Highway Department. There were 3,582 motorcycle accidents and 3,768 victims in the period. The motorcycle fleet increased by 72.8%, with involvement in accidents increasing by 42.2%, while accidents involving other vehicles only increased by 9.2%. As regards victims, there is a predominance of men, with rates of 561.1, with the age groups of between 20 and 29 and 30 and 39 being the highest, with 755.4 and 542.2, respectively. With reference to accident characteristics, the highest number of accidents - 32.4% - occurred in the afternoon, followed by the morning with 29.2% and the evening with 28.9%. 18.3% occurred on Saturdays and 15.7% on Sundays. Collisions were the commonest kind of accident, with 3,036 (84.8%) occurrences. The conclusion drawn is that it is essential to stage ongoing preventive programs and ensure greater integration among the institutions involved, with planning and campaigns to reverse the current situation.

  10. Optimization of nonribosomal peptides production by a psychrotrophic fungus: Trichoderma velutinum ACR-P1.

    PubMed

    Sharma, Richa; Singh, Varun P; Singh, Deepika; Yusuf, Farnaz; Kumar, Anil; Vishwakarma, Ram A; Chaubey, Asha

    2016-11-01

    Trichoderma is an anamorphic filamentous fungal genus with immense potential for production of small valuable secondary metabolites with indispensable biological activities. Microbial dynamics of a psychrotrophic strain Trichoderma velutinum ACR-P1, isolated from unexplored niches of the Shiwalik region, bestowed with rich biodiversity of microflora, was investigated for production of nonribosomal peptides (NRPs) by metabolite profiling by intact-cell mass spectrometry (ICMS) employing matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometer. Being the first report on NRPs production by T. velutinum, studies on optimization of growth conditions by Response Surface Methodology (RSM) for production of NRPs by ACR-P1 was carried out strategically. Multifold enhancement in the yield of NRPs belonging to subfamily SF4 with medium chain of amino acid residues having m/z 1437.9, 1453.9, and 1452.0 at pH 5.9 at 20 °C and of subfamily SF1 with long-chain amino acid residues having m/z 1770.2, 1784.2, 1800.1, 1802.1, and 1815.1 was achieved at pH 7.0 at 25 °C. Complexities of natural mixtures were thus considerably reduced under respective optimized culture conditions accelerating the production of novel microbial natural products by saving time and resources.

  11. Simulated microgravity affects ciprofloxacin susceptibility and expression of acrAB-tolC genes in E. coli ATCC25922

    PubMed Central

    Xu, Bingxin; Li, Chenglin; Zheng, Yanhua; Si, Shaoyan; Shi, Yuhua; Huang, Yuling; Zhang, Jianzhong; Cui, Yan; Cui, Yimin

    2015-01-01

    As a representative fluoroquinolone antibacterial, ciprofloxacin is frequently used to treat infections caused by bacteria such as E. coli. It is much meaningful to explore ciprofloxacin susceptibility and investigate a possible mechanism of drug susceptibility changes in E. coli ATCC25922 exposed to the environmental stress of simulated microgravity. The subculture of E. coli lasted for 7 days under simulated microgravity conditions (SMG) and normal microgravity (NG) conditions. On the 8th day, the cultures were divided into three groups: (1) NG group (continuous NG cultures); (2) SMG group (continuous SMG cultures); (3) SMCNG group (simulated microgravity change into normal gravity cultures). Ciprofloxacin (a final concentration of 0.125 μg/ml) sensitivity and expression of acrAB-tolC genes were detected in E. coli cells. The count and percentage of viable cells in the SMG cultures bacteria exposed to ciprofloxacin were higher than that in NG cultures and reduced to the levels of NG group when they were subcultivated from SMG to NG. The expressions of efflux pump genes (acrA, acrB and tolC) were upregulated in SMG culture and downregulated to the levels of NG group when they were subcultivated from SMG to NG. Susceptibility to ciprofloxacin and expression of acrAB-tolC genes in E. coli could be reversibly affected by SMG conditions. Over expression of efflux pump genes acrAB-tolC perhaps played an important role in decreased CIP susceptibility under SMG. PMID:26339360

  12. Simulated microgravity affects ciprofloxacin susceptibility and expression of acrAB-tolC genes in E. coli ATCC25922.

    PubMed

    Xu, Bingxin; Li, Chenglin; Zheng, Yanhua; Si, Shaoyan; Shi, Yuhua; Huang, Yuling; Zhang, Jianzhong; Cui, Yan; Cui, Yimin

    2015-01-01

    As a representative fluoroquinolone antibacterial, ciprofloxacin is frequently used to treat infections caused by bacteria such as E. coli. It is much meaningful to explore ciprofloxacin susceptibility and investigate a possible mechanism of drug susceptibility changes in E. coli ATCC25922 exposed to the environmental stress of simulated microgravity. The subculture of E. coli lasted for 7 days under simulated microgravity conditions (SMG) and normal microgravity (NG) conditions. On the 8th day, the cultures were divided into three groups: (1) NG group (continuous NG cultures); (2) SMG group (continuous SMG cultures); (3) SMCNG group (simulated microgravity change into normal gravity cultures). Ciprofloxacin (a final concentration of 0.125 μg/ml) sensitivity and expression of acrAB-tolC genes were detected in E. coli cells. The count and percentage of viable cells in the SMG cultures bacteria exposed to ciprofloxacin were higher than that in NG cultures and reduced to the levels of NG group when they were subcultivated from SMG to NG. The expressions of efflux pump genes (acrA, acrB and tolC) were upregulated in SMG culture and downregulated to the levels of NG group when they were subcultivated from SMG to NG. Susceptibility to ciprofloxacin and expression of acrAB-tolC genes in E. coli could be reversibly affected by SMG conditions. Over expression of efflux pump genes acrAB-tolC perhaps played an important role in decreased CIP susceptibility under SMG.

  13. The advantages of PD1 activating chimeric receptor (PD1-ACR) engineered lymphocytes for PDL1(+) cancer therapy.

    PubMed

    Tang, Xiaolong; Li, Qingguo; Zhu, Yongqiang; Zheng, Donghui; Dai, Jingjing; Ni, Wenxuan; Wei, Jia; Xue, Yubao; Chen, Ke; Hou, Wei; Zhang, Chao; Feng, Xiaojun; Liang, Yong

    2015-01-01

    Tumors exploit immunoregulatory checkpoints to attenuate T cell responses as a means of circumventing immunologic rejection. By activating the inhibitory costimulatory pathway of Programmed Death 1 (PD1)/PDL1 which provides tumor cells an escape mechanism from immune surveillance, Programmed Death Ligand1 (PDL1)(+) tumors hamper activated tumor-specific T cell functions and render them functionally exhausted. To overcome the inhibitory costimulatory effects of PDL1 on the adoptively transferred T cells, we sought to convert PD1 to a T cell costimulatory receptor by exchanging its transmembrane and cytoplasmic tail with CD28 and 4-1BB signaling domains (PD1-CD28-4-1BB, PD1-ACR), anticipating the genetically modified effector T lymphocytes expressing PD1-ACR would exhibit enhanced functional attributes. And the results showed that PD1-ACR expressed T cells retained the ability to bind PDL1, resulting in T cell activation as evidenced by the elevated activity of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), the augmentation of cytokine secretion and the increased proliferative capacity. Moreover, when systemically administered in the mouse model of glioblastoma metastases, PD1-ACR T cells localized at the area of U87 invasive tumor, which results in suppressed tumor growth and enhanced survival of mice with established U87 glioblastoma. Together, these data demonstrated that PD1-ACR has a high potential to serve as a novel strategy to overcome PDL1 mediated immunosuppression of T cells for cancer therapy.

  14. Self Organization of Pb Islands on Si(111) Caused by Quantum Size Effects

    NASA Astrophysics Data System (ADS)

    Hong, Hawoong; Basile, Leo; Czoschke, Peter; Gray, Aaron; Chiang, Tai-Chang

    2007-03-01

    Growth of metallic Pb islands on Si(111) by vacuum deposition was studied in real time using synchrotron x-ray diffraction. The islands coarsen and order, maintaining a nearly uniform inter-island distance but without angular correlation. The resulting inter-island structure is akin to a two-dimensional liquid. Over a wide temperature range, the inter-island ordering is well correlated with the development of ``magic'' island heights caused by energy minimization of the Pb electrons. The results demonstrate quantum confinement effects as a driving force for self organization, as opposed to strain effects that generally govern the formation of semiconductor quantum dot arrays.

  15. Poly(ethylene glycol) self-assembled monolayer island growth.

    PubMed

    Rundqvist, Jonas; Hoh, Jan H; Haviland, David B

    2005-03-29

    Here, we report a study of the morphology and growth dynamics of a self-assembled monolayer (SAM) of the amide containing poly(ethylene glycol) (PEG) thiol (CH3O(CH2CH2O)17NHCO(CH2)2SH) on atomically flat Au(111) surfaces. SAM growth from a 20 muM ethanolic solution reveals island growth through three distinct steps: island nucleation, island growth, and coalescence. The coalescence-step, filling voids in the SAM, is by far slowest. The fine structure study reveals dendritic island formation, an observation which can be explained by attractive intermolecular interactions and surface diffusion-limited aggregation. We have also observed a change in the island height, which peaks during the island growth phase. This height change can be associated with a molecular conformational transition.

  16. Laser deposition of bimetallic island films

    NASA Astrophysics Data System (ADS)

    Kucherik, A. O.; Arakelyan, S. M.; Kutrovskaya, S. V.; Osipov, A. V.; Istratov, A. V.; Vartanyan, T. A.; Itina, T. E.

    2016-08-01

    In this work the results of a bimetallic Au-Ag structure deposition from the colloidal system by nanosecond laser radiation are presented. The formation of the extended arrays of gold and silver nanoparticles with controlled morphology is examined. We report the results of formation bimetallic islands films with various electrical and optical properties. The changes in the optical properties of the obtained thin films are found to depend on their morphology.

  17. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    SciTech Connect

    DOE /NV

    2001-04-05

    This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

  18. Organic maturation and thermal history of Queen Charlotte Islands

    SciTech Connect

    Bustin, R.M.; Vellutini, D. )

    1989-09-01

    The level of organic maturation and thermal history of Mesozoic and Tertiary strata of the Queen Charlotte Islands have been determined with vitrinite reflectance (R{sub 0}), numerical modeling (modified Arrhenius model), and Rock-Eval Pyrolysis. The level of organic maturation increases from northern Graham to southern Moresby Island, which primarily reflects high heat flow resulting from Middle to Late Jurassic and Eocene to Oligocene plutonism and cospatial dyking. Upper Triassic-Lower Jurassic and most Cretaceous strata are overmature on Moresby Island, with R{sub 0} values ranging from 2.40 to 5.80%. Jurassic, Cretaceous, and Tertiary strata are immature to overmature on Graham Island, with R{sub 0} values ranging from 0.15% (Skonun Formation) to 2.4% (Haida Formation). Locally, R{sub 0} values up to 3.2% on Graham Island and 8.3% on Moresby Island occur adjacent to igneous intrusives. Modeling measured levels of organic maturation suggests that elevated geothermal gradients ranging from 83{degree} to 150{degree}C/km existed during Yakoun (183-178 Ma) and Masset (35-10 Ma) volcanism on Graham Island. Numerical modeling further suggests that Triassic strata on Fredrick Island and Kennecott Point (Graham Island) entered the oil window during the early Miocene, whereas Jurassic strata at Rennell Junction and Cumshewa Inlet entered the oil window during the Bajocian. Cretaceous strata on north and south Graham Island entered the oil window during the early Miocene and are currently within the oil window. The Tertiary Skonun Formation is generally immature except for strata on west and northeast Graham Island, which entered the oil window in the late Miocene.

  19. Isolation and Characterization of Mayaro Virus from a Human in Acre, Brazil

    PubMed Central

    Terzian, Ana Carolina B.; Auguste, Albert J.; Vedovello, Danila; Ferreira, Marcelo U.; da Silva-Nunes, Mônica; Sperança, Márcia A.; Suzuki, Rodrigo B.; Juncansen, Camila; Araújo, João P.; Weaver, Scott C.; Nogueira, Maurício L.

    2015-01-01

    Mayaro virus (MAYV) is widely distributed throughout South America and is the etiologic agent of Mayaro fever, an acute febrile illness often presenting with arthralgic manifestations. The true incidence of MAYV infection is likely grossly underestimated because the symptomatic presentation is very similar to that of dengue fever and other acute febrile tropical diseases. We report the complete genome sequence of a MAYV isolate detected from an Acrelândia patient presenting with fever, chills, and sweating, but with no arthralgia. Results show that this isolate belongs to genotype D and is closely related to Bolivian strains. Our results suggest that the Acre/Mayaro strain is closely related to the progenitor of these Bolivian strains that were isolated between 2002 and 2006. PMID:25510721

  20. Isolation and characterization of Mayaro virus from a human in Acre, Brazil.

    PubMed

    Terzian, Ana Carolina B; Auguste, Albert J; Vedovello, Danila; Ferreira, Marcelo U; da Silva-Nunes, Mônica; Sperança, Márcia A; Suzuki, Rodrigo B; Juncansen, Camila; Araújo, João P; Weaver, Scott C; Nogueira, Maurício L

    2015-02-01

    Mayaro virus (MAYV) is widely distributed throughout South America and is the etiologic agent of Mayaro fever, an acute febrile illness often presenting with arthralgic manifestations. The true incidence of MAYV infection is likely grossly underestimated because the symptomatic presentation is very similar to that of dengue fever and other acute febrile tropical diseases. We report the complete genome sequence of a MAYV isolate detected from an Acrelândia patient presenting with fever, chills, and sweating, but with no arthralgia. Results show that this isolate belongs to genotype D and is closely related to Bolivian strains. Our results suggest that the Acre/Mayaro strain is closely related to the progenitor of these Bolivian strains that were isolated between 2002 and 2006.

  1. ACR-ASNR Practice Parameter for Brain PET/CT Imaging Dementia.

    PubMed

    Frey, Kirk A; Lodge, Martin A; Meltzer, Carolyn Cidis; Peller, Patrick J; Wong, Terence Z; Hess, Christopher P; Petrella, Jeffrey R; Sair, Haris I; Subramaniam, Rathan M

    2016-02-01

    This practice parameter is for both FDG and amyloid brain PET or PET/computed tomography (CT) for patients with cognitive decline, and has been developed collaboratively by the American College of Radiology (ACR) and the American Society for Neuroradiology (ASNR). It is estimated that the number of people with dementia, 36.5 million worldwide in 2010, will increase to 65.7 million in 2030 and to 115 million in 2050. Four primary neurodegenerative etiologies of dementia have been defined: Alzheimer disease (AD), vascular dementia, frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB). Alzheimer disease is the most common form of dementia, accounting for approximately 60%-80% of all cases. Indications for FDG and amyloid brain PET and qualifications for personnel are discussed in this practice parameter.

  2. Magnetically induced phonon splitting in ACr2O4 spinels from first principles

    DOE PAGES

    Wysocki, Aleksander L.; Birol, Turan

    2016-04-22

    We study the magnetically-induced phonon splitting in cubic ACr2O4 (A=Mg, Zn, Cd) spinels from first principles and demonstrate that the sign of the splitting, which is experimentally observed to be opposite in CdCr2O4 compared to ZnCr2O4 and MgCr2O4, is determined solely by the particular magnetic ordering pattern observed in these compounds. We further show that this interaction between magnetism and phonon frequencies can be fully described by the previously proposed spin-phonon coupling model [C. J. Fennie and K. M. Rabe, Phys. Rev. Lett. 96, 205505 (2006)] that includes only the nearest neighbor exchange. In conclusion, using this model with materialsmore » specific parameters calculated from first principles, we provide additional insights into the physics of spin-phonon coupling in this intriguing family of compounds.« less

  3. Reversal of the Drug Binding Pocket Defects of the AcrB Multidrug Efflux Pump Protein of Escherichia coli

    PubMed Central

    Soparkar, Ketaki; Kinana, Alfred D.; Weeks, Jon W.; Morrison, Keith D.; Nikaido, Hiroshi

    2015-01-01

    ABSTRACT The AcrB protein of Escherichia coli, together with TolC and AcrA, forms a contiguous envelope conduit for the capture and extrusion of diverse antibiotics and cellular metabolites. In this study, we sought to expand our knowledge of AcrB by conducting genetic and functional analyses. We began with an AcrB mutant bearing an F610A substitution in the drug binding pocket and obtained second-site substitutions that overcame the antibiotic hypersusceptibility phenotype conferred by the F610A mutation. Five of the seven unique single amino acid substitutions—Y49S, V127A, V127G, D153E, and G288C—mapped in the periplasmic porter domain of AcrB, with the D153E and G288C mutations mapping near and at the distal drug binding pocket, respectively. The other two substitutions—F453C and L486W—were mapped to transmembrane (TM) helices 5 and 6, respectively. The nitrocefin efflux kinetics data suggested that all periplasmic suppressors significantly restored nitrocefin binding affinity impaired by the F610A mutation. Surprisingly, despite increasing MICs of tested antibiotics and the efflux of N-phenyl-1-naphthylamine, the TM suppressors did not improve the nitrocefin efflux kinetics. These data suggest that the periplasmic substitutions act by influencing drug binding affinities for the distal binding pocket, whereas the TM substitutions may indirectly affect the conformational dynamics of the drug binding domain. IMPORTANCE The AcrB protein and its homologues confer multidrug resistance in many important human bacterial pathogens. A greater understanding of how these efflux pump proteins function will lead to the development of effective inhibitors against them. The research presented in this paper investigates drug binding pocket mutants of AcrB through the isolation and characterization of intragenic suppressor mutations that overcome the drug susceptibility phenotype of mutations affecting the drug binding pocket. The data reveal a remarkable structure

  4. Ober's Island, One of the Review Islands on Rainy Lake, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  5. Classification Criteria for Systemic Sclerosis: An ACR-EULAR Collaborative Initiative

    PubMed Central

    van den Hoogen, Frank; Khanna, Dinesh; Fransen, Jaap; Johnson, Sindhu R.; Baron, Murray; Tyndall, Alan; Matucci-Cerinic, Marco; Naden, Raymond; Riemekasten, Gabriela; Carreira, Patricia; Gabrielli, Armando; Distler, Oliver; van Laar, Jacob M; Valentini, Gabriele; Denton, Christopher P; Kowal-Bielecka, Otylia; Inanc, Murat; Allanore, Yannick; Walker, Ulrich A; Müller-Ladner, Ulf; Vonk, Madelon; Czirjak, Laszlo; Herrick, Ariane; Sierakowski, Stanislav; Veale, Douglas; Chung, Lorinda; Clements, Phillip; Fessler, Barry J; Furst, Dan; Guiducci, Serena; Hsu, Vivian; Mayes, Maureen; Medsger, Thomas A; Merkel, Peter; Silver, Richard; Steen, Virginia; Varga, John; Collier, David; Csuka, Mary Ell; Jimenez, Sergio; Kahaleh, Bashar; Seibold, James R; Simms, Robert; Pope, Janet

    2013-01-01

    Background The 1980 classification criteria for systemic sclerosis (SSc) lack sensitivity in early SSc and limited cutaneous SSc. A joint ACR-EULAR committee was established to develop new classification criteria for SSc. Methods Using consensus methods, 23 candidate items were arranged in a multi-criteria additive point system with a threshold to classify cases as SSc. The classification system was reduced by clustering items, and simplifying weights. The system was tested by: a) determining specificity and sensitivity in SSc cases and controls with scleroderma-like disorders; b) validating against the combined view of a group of experts on a set of cases with or without SSc. Results Skin thickening of the fingers extending proximal to the MCPs is sufficient to be classified as SSc, if that is not present, seven additive items apply with varying weights for each: skin thickening of the fingers, finger tip lesions, telangiectasia, abnormal nailfold capillaries, interstitial lung disease or pulmonary arterial hypertension, Raynaud's phenomenon, and SSc-related autoantibodies. Sensitivity and specificity in the validation sample were 0.91 and 0.92 for the new classification criteria and 0.75 and 0.72 for the 1980 ARA classification criteria. All selected cases were classified in accordance with consensus-based expert opinion. All cases classified as SSc by the 1980 ARA criteria were classified with the new criteria, and several additional cases were now considered to be SSc. Conclusion The ACR-EULAR classification criteria for SSc performed better than the 1980 ARA Criteria for SSc and should allow for more patients to be classified correctly as SSc. PMID:24122180

  6. Native Americans, regional drought and tree Island evolution in the Florida Everglades

    USGS Publications Warehouse

    Bernhardt, C.

    2011-01-01

    This study uses palynologic data to determine the effects of regional climate variability and human activity on the formation and development of tree islands during the last ~4000 years. Although prolonged periods of aridity have been invoked as one mechanism for their formation, Native American land use has also been hypothesized as a driver of tree island development. Using pollen assemblages from head and near tail sediments collected on two tree islands and documented archeological data, the relative roles of Native Americans, climate variability, and recent water-management practices in forming and structuring Everglades tree islands are examined. The timing of changes recorded in the pollen record indicates that tree islands developed from sawgrass marshes ~3800 cal. yr BP, prior to human occupation. Major tree island expansion, recorded near tail sediments, occurred ~1000 years after initial tree island formation. Comparison of the timing of pollen assemblages with other proxy records indicates that tree island expansion is related to regional and global aridity correlated with southward migration of the Intertropical Convergence Zone. Local fire associated with droughts may also have influenced tree island expansion. This work suggests that Native American occupation did not significantly influence tree island formation and that the most important factors governing tree island expansion are extreme hydrologic events due to droughts and intense twentieth century water management.

  7. Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest

    PubMed Central

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2015-01-01

    The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands. PMID:25920672

  8. Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest.

    PubMed

    Duryea, M C; Zamudio, K R; Brasileiro, C A

    2015-09-01

    The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance also contributes to the diversity of island populations. We examined one such case on continental islands in southeastern Brazil, to determine how classic island biogeography predictions and past vicariance explain the population genetic diversity of Thoropa taophora, a frog endemic to the Atlantic Coastal Forest. We used nuclear microsatellite markers to examine the genetic diversity of coastal and island populations of this species. We found that island isolation has a role in shaping the genetic diversity of continental island species, with island populations being significantly less diverse than coastal populations. However, area of the island and distance from coast had no significant effect on genetic diversity. We also found no significant differences between migration among coastal populations and migration to and from islands. We discuss how vicariance and the effects of continued migration between coastal and island populations interact to shape evolutionary patterns on continental islands.

  9. Bouvet Island near Antarctica

    Atmospheric Science Data Center

    2013-04-16

    ... an obstacle to the westerly winds, and wake patterns in the cloud layers are visible downstream of the island's location. In the lower left ... the lower right image, the island is partially obscured by cumulus clouds, and a spiral cloud pattern associated with an atmospheric ...

  10. Back to Treasure Island

    ERIC Educational Resources Information Center

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  11. Marine and Island Ecology.

    ERIC Educational Resources Information Center

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  12. 75 FR 61227 - Advisory Committee on Reactor Safeguards Meeting of the ACRS Subcommittee on Future Plant Designs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ..., General Electric--Hitachi Nuclear Energy (GEH), and their contractors, pursuant to 5 U.S.C. 552b(c)(4... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards Meeting of the ACRS Subcommittee on Future Plant...

  13. From the Lab Bench: Do you manage pastures for maximum gain per animal or gain per acre?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An article was written to discuss managing cattle pastures to maximize either weight gain or milk output per acre or per animal. There is no or little change in output per animal over a certain range of light stocking rates that allows pasture growth to be greater than forage intake, and increasing...

  14. Effects of artificial-recharge experiments at Ship Creek alluvial fan on water levels at Spring Acres Subdivision, Anchorage, Alaska

    USGS Publications Warehouse

    Meyer, William; Patrick, Leslie

    1980-01-01

    The effect of the artificial recharge experiments on water levels at Spring Acres subdivision, Anchorage, Alaska, was evaluated using two digital models constructed to simulate groundwater movement and water-level rises induced by the artificial recharge. The models predicted that the artificial recharge would have caused water levels in the aquifer immediately underlying Spring Acres subdivision to rise 0.2 foot from May 20 to August 7, 1975. The models also predicted a total rise in groundwater levels of 1.1 feet at this location from July 16, 1973 to August 7, 1975, as a result of the artificial-recharge experiments. Water-level data collected from auger holes in March 1975 by a consulting firm for the contractor indicated a depth to water of 6-7 feet below land surface at Spring Acres subdivision at this time. Water levels measured in and near Spring Acres subdivision several years before and after the 1973-75 artificial-recharge experiments showed seasonal rises of 2 to 12.4 feet. A depth to water below land surface of 2.6 feet was measured 600 feet from the subdivision in 1971 and in the subdivision in 1977. Average measured depth to water in the area was 7.0 feet from early 1976 to September 1979. (USGS)

  15. ‘WhiteAcre-DG’, a Small-seeded, Cream-type Southernpea with an Enhanced Persistent Green Seed Phenotype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA has released a high yielding, small-seeded, cream-type southernpea cultivar that has a persistent green seed phenotype conditioned by both the green cotyledon gene (gc) and the green testa gene (gt). The new cultivar, named ‘WhiteAcre-DG’, can be harvested at the dry-pod stage of maturity ...

  16. Design of New Antibacterial Enhancers Based on AcrB’s Structure and the Evaluation of Their Antibacterial Enhancement Activity

    PubMed Central

    Song, Yi; Qin, Rongxin; Pan, Xichun; Ouyang, Qin; Liu, Tianyu; Zhai, Zhaoxia; Chen, Yingchun; Li, Bin; Zhou, Hong

    2016-01-01

    Previously, artesunate (AS) and dihydroartemisinine 7 (DHA7) were found to have antibacterial enhancement activity against Escherichia coli via inhibition of the efflux pump AcrB. However, they were only effective against E. coli standard strains. This study aimed to develop effective antibacterial enhancers based on the previous work. Our results demonstrate that 86 new antibacterial enhancers were designed via 3D-SAR and molecular docking. Among them, DHA27 had the best antibacterial enhancement activity. It could potentiate the antibacterial effects of ampicillin against not only E. coli standard strain but also clinical strains, and of β-lactam antibiotics, not non-β-lactamantibiotics. DHA27 could increase the accumulation of daunomycin and nile red within E. coli ATCC 35218, but did not increase the bacterial membrane permeability. DHA27 reduced acrB’s mRNA expression of E. coli ATCC 35218 in a dose-dependent manner, and its antibacterial enhancement activity is related to the degree of acrB mRNA expression in E. coli clinical strains. The polypeptides from AcrB were obtained via molecular docking assay; the pre-incubated polypeptides could inhibit the activity of DHA27. Importantly, DHA27 had no cytotoxicity on cell proliferation. In conclusion, among newly designed antibacterial enhancers, DHA27 had favorable physical and pharmacological properties with no significant cytotoxicity at effective concentrations, and might serve as a potential efflux pump inhibitor in the future. PMID:27869748

  17. Seasonal Variations in CO2 Fluxes in Fluvial Systems in Southstern of Amazonia (acre, Brazil)

    NASA Astrophysics Data System (ADS)

    Sousa, E.; Krusche, A. V.; Salimon, C. I.; Victoria, R. L.; Sawakuchi, H.

    2012-12-01

    Our main objective was to measure the CO2 fluxes in 5 (five) rivers and 2 (two) streams in the Purus Basin. These rivers and streams have different size, water chemical characteristics and type soil, despite all are classified as white-water rivers. We toke measures of pH, electrical conductivity, pCO2, DOC and DIC concentrations and CO2 fluxes in two seasonal periods: Wet Season (dez2010-abr2011 and dez2011-abr2012) and Dry Season (jul2011-set2011). Water samples were taken to DOC (filtered with quartz filters and preserved with hydrochloric acid), DIC (filtered with cellulose acetate filters and preserved with thymol) and δ13C of DIC. These water samples were sent to CENA/USP to be analyzed. EC and pH measurements were made with portable meters. Partial pressure of CO2 (pCO2) was measure with an equilibrator and CO2 fluxes with a floating chamber. Precipitation, water stage and discharge data was obtained by UFAC climatological station and ANA (National Water Agency). Statistical analysis were made using R Program. DOC and DIC concentrations presented significant differences between the periods. In the wet season were observed the highest values to DOC concentrations in all rivers and streams. In the rivers, these concentrations varied between 7.09±3.10 (Acre River) and 9.32±2.31 mg.L-1 (Rôla River). In the dry season, the values observed were 3.15±1.11 (Acre River) and 7.96±0.11 (Caeté River). In the streams, these concentrations also higher in the wet season, with 1.68±0.32 mg.L-1 in the Floresta stream and 3.22±1.08 mg.L-1 in the Escondido stream. To DIC concentrations, this pattern was inverted, with higher concentrations observed in the dry season. Iaco River presented the higher concentration (50.8±4.7 mg.L-1) and Acre River the lower concentration (11.30±2.77 mg.L-1). Despite the DIC concentrations were higher in the dry season, the pCO2 and CO2 fluxes values were higher in the wet season. In the rivers, the pCO2 values varied between 4,189±1

  18. Bioinjection Performance Review for the Building 100 Area and 4.5 Acre Site at the Pinellas County, Florida, Site

    SciTech Connect

    Survochak, Scott; Daniel, Joe

    2016-05-01

    This document provides a summary of a review of the performance of bioinjection activities at the Building 100 Area and the 4.5 Acre Site at the Pinellas County, Florida, Site since 2010, determines how best to optimize future injection events, and identifies the approach for the bioinjection event in 2016 at (1) the 4.5 Acre Site and (2) the Essentra property at the Building 100 Area. Because this document describes the next bioinjection event at the 4.5 Acre Site, it also serves as an addendum to the Interim Remedial Action Plan for Emulsified Edible Oil Injection at the 4.5 Acre Site (DOE 2013). In addition, this document revises the injection layout and injection intervals for the Essentra property that were originally described in the Interim Corrective Measure Work Plan for Source and Plume Treatment at the Building 100 Area (DOE 2014), and is a de facto update of that document. Bioinjection consists of injection of emulsified vegetable oil (EVO) and the microorganism Dehalococcoides mccartyi (DHM; formerly known as Dehalococcoides ethenogenes) into the subsurface to enhance biodegradation of trichloroethene (TCE), dichloroethene (DCE), and vinyl chloride (VC). VC is the only contaminant that exceeds its maximum contaminant level (10 micrograms per liter onsite and 1 microgram per liter onsite) on the 4.5 Acre Site and the Essentra property. Bioinjection was conducted at the 4.5 Acre Site in 2010 and 2013. Approximately 49,900 gallons of EVO and DHM were injected at 95 injection points in February 2010, and approximately 22,900 gallons of EVO and DHM were injected at 46 injection points in July 2013. The injection locations are shown on Figure 1. The goal of bioinjection at the 4.5 Acre Site is to decrease contaminant concentrations to maximum contaminant levels along the west and southwest property boundaries (to meet risk–based corrective action requirements) and to minimize the extent of the contaminant plume in the interior of the site. Bioinjection was

  19. Conceptual model and numerical simulation of the groundwater-flow system of Bainbridge Island, Washington

    USGS Publications Warehouse

    Frans, Lonna M.; Bachmann, Matthew P.; Sumioka, Steve S.; Olsen, Theresa D.

    2011-01-01

    Groundwater is the sole source of drinking water for the population of Bainbridge Island. Increased use of groundwater supplies on Bainbridge Island as the population has grown over time has created concern about the quantity of water available and whether saltwater intrusion will occur as groundwater usage increases. A groundwater-flow model was developed to aid in the understanding of the groundwater system and the effects of groundwater development alternatives on the water resources of Bainbridge Island. Bainbridge Island is underlain by unconsolidated deposits of glacial and nonglacial origin. The surficial geologic units and the deposits at depth were differentiated into aquifers and confining units on the basis of areal extent and general water-bearing characteristics. Eleven principal hydrogeologic units are recognized in the study area and form the basis of the groundwater-flow model. A transient variable-density groundwater-flow model of Bainbridge Island and the surrounding area was developed to simulate current (2008) groundwater conditions. The model was calibrated to water levels measured during 2007 and 2008 using parameter estimation (PEST) to minimize the weighted differences or residuals between simulated and measured hydraulic head. The calibrated model was used to make some general observations of the groundwater system in 2008. Total flow through the groundwater system was about 31,000 acre-ft/ yr. The recharge to the groundwater system was from precipitation and septic-system returns. Groundwater flow to Bainbridge Island accounted for about 1,000 acre-ft/ yr or slightly more than 5 percent of the recharge amounts. Groundwater discharge was predominately to streams, lakes, springs, and seepage faces (16,000 acre-ft/yr) and directly to marine waters (10,000 acre-ft/yr). Total groundwater withdrawals in 2008 were slightly more than 6 percent (2,000 acre-ft/yr) of the total flow. The calibrated model was used to simulate predevelopment conditions

  20. Worldwide Diversity and Occurrence of Arsenite Transporter acr3(2) Suggests an Important and Overlooked Pathway

    NASA Astrophysics Data System (ADS)

    Mailloux, B. J.; Wagner, P.; Foster, R.; Stolz, J. F.; Scholz, M.; Wovkulich, K.; Freyer, G. A.

    2009-12-01

    Arsenic is a toxic element that occurs naturally in the environment. Microorganisms have detoxification pathways that involve the expulsion of arsenite from the cytoplasm. The genes encoding these processes, including acr3(2), have been well studied in laboratory. However, comparatively less is known of detoxification genes in the environment. Here we report on the environmental diversity of acr3(2), an arsenite transporter gene, in 15 samples from a variety of habitats, including 2 marine samples from near the Amazon River plume, 2 sediment samples from California Soda Lakes (Mono and Searle), 8 groundwater samples from Bangladesh, 1 sediment sample from Union Lake, NJ, and 2 microcosm experiments using sediment from the Vineland Chemical Co Superfund site, NJ amended with acetate and arsenate. These sites were chosen to represent a variety arsenic impacted environments. Aqueous concentrations of arsenic ranged from below 13 nM to 5.6 mM (1 ppb to 422 ppm). Fifteen clone libraries were generated, and the 304 unique sequences clustered with or near Proteobacteria, Cyanobacteria , Euryarchaeota (Archaea),Acidobacteria, Thermatogae (Archaea), Planctomycetes, Bacteroidetes and Firmicutes. Thus, the acr3(2) gene appears to be highly conserved worldwide and across the domains of Archaea and Bacteria. Comparison of clone libraries, however, indicated that individual sites had distinct communities. Rarefraction analysis and CHAO1 estimation of species richness showed that even with 1406 available acr sequences from JGI and this study, the known diversity of the gene is not saturated. These results suggests that the acr3(2) gene and detoxification in general may be more important than previously thought in environmental arsenic cycling and mobilization.

  1. The Ascaris suum nicotinic receptor, ACR-16, as a drug target: Four novel negative allosteric modulators from virtual screening

    PubMed Central

    Zheng, Fudan; Robertson, Alan P.; Abongwa, Melanie; Yu, Edward W.; Martin, Richard J.

    2016-01-01

    Soil-transmitted helminth infections in humans and livestock cause significant debility, reduced productivity and economic losses globally. There are a limited number of effective anthelmintic drugs available for treating helminths infections, and their frequent use has led to the development of resistance in many parasite species. There is an urgent need for novel therapeutic drugs for treating these parasites. We have chosen the ACR-16 nicotinic acetylcholine receptor of Ascaris suum (Asu-ACR-16), as a drug target and have developed three-dimensional models of this transmembrane protein receptor to facilitate the search for new bioactive compounds. Using the human α7 nAChR chimeras and Torpedo marmorata nAChR for homology modeling, we defined orthosteric and allosteric binding sites on the Asu-ACR-16 receptor for virtual screening. We identified four ligands that bind to sites on Asu-ACR-16 and tested their activity using electrophysiological recording from Asu-ACR-16 receptors expressed in Xenopus oocytes. The four ligands were acetylcholine inhibitors (SB-277011-A, IC50, 3.12 ± 1.29 μM; (+)-butaclamol Cl, IC50, 9.85 ± 2.37 μM; fmoc-1, IC50, 10.00 ± 1.38 μM; fmoc-2, IC50, 16.67 ± 1.95 μM) that behaved like negative allosteric modulators. Our work illustrates a structure-based in silico screening method for seeking anthelmintic hits, which can then be tested electrophysiologically for further characterization. PMID:27054065

  2. The Ascaris suum nicotinic receptor, ACR-16, as a drug target: Four novel negative allosteric modulators from virtual screening.

    PubMed

    Zheng, Fudan; Robertson, Alan P; Abongwa, Melanie; Yu, Edward W; Martin, Richard J

    2016-04-01

    Soil-transmitted helminth infections in humans and livestock cause significant debility, reduced productivity and economic losses globally. There are a limited number of effective anthelmintic drugs available for treating helminths infections, and their frequent use has led to the development of resistance in many parasite species. There is an urgent need for novel therapeutic drugs for treating these parasites. We have chosen the ACR-16 nicotinic acetylcholine receptor of Ascaris suum (Asu-ACR-16), as a drug target and have developed three-dimensional models of this transmembrane protein receptor to facilitate the search for new bioactive compounds. Using the human α7 nAChR chimeras and Torpedo marmorata nAChR for homology modeling, we defined orthosteric and allosteric binding sites on the Asu-ACR-16 receptor for virtual screening. We identified four ligands that bind to sites on Asu-ACR-16 and tested their activity using electrophysiological recording from Asu-ACR-16 receptors expressed in Xenopus oocytes. The four ligands were acetylcholine inhibitors (SB-277011-A, IC50, 3.12 ± 1.29 μM; (+)-butaclamol Cl, IC50, 9.85 ± 2.37 μM; fmoc-1, IC50, 10.00 ± 1.38 μM; fmoc-2, IC50, 16.67 ± 1.95 μM) that behaved like negative allosteric modulators. Our work illustrates a structure-based in silico screening method for seeking anthelmintic hits, which can then be tested electrophysiologically for further characterization.

  3. Drug uptake pathways of multidrug transporter AcrB studied by molecular simulations and site-directed mutagenesis experiments.

    PubMed

    Yao, Xin-Qiu; Kimura, Nobuhiro; Murakami, Satoshi; Takada, Shoji

    2013-05-22

    Multidrug resistance has been a critical issue in current chemotherapy. In Escherichia coli , a major efflux pump responsible for the multidrug resistance contains a transporter AcrB. Crystallographic studies and mutational assays of AcrB provided much of structural and overall functional insights, which led to the functionally rotating mechanism. However, the drug uptake pathways are somewhat controversial because at least two possible pathways, the vestibule and the cleft paths, were suggested. Here, combining molecular simulations and site-directed mutagenesis experiments, we addressed the uptake mechanism finding that the drug uptake pathways can be significantly different depending on the properties of drugs. First, in the computational free energy analysis of drug movements along AcrB tunnels, we found a ligand-dependent drug uptake mechanism. With the same molecular sizes, drugs that are both strongly hydrophobic and lipophilic were preferentially taken in via the vestibule path, while other drugs favored the cleft path. Second, direct simulations realized totally about 3500 events of drug uptake by AcrB for a broad range of drug property. These simulations confirmed the ligand-dependent drug uptake and further suggested that a smaller drug favors the vestibule path, while a larger one is taken in via the cleft path. Moreover, the direct simulations identified an alternative uptake path which is not visible in the crystal structure. Third, site-directed mutagenesis of AcrB in E. coli verified that mutations of residues located along the newly identified path significantly reduced the efflux efficiency, supporting its relevance in in vivo function.

  4. 43 CFR 2806.23 - How will the BLM calculate my rent for linear rights-of-way the Per Acre Rent Schedule covers?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... linear rights-of-way the Per Acre Rent Schedule covers? 2806.23 Section 2806.23 Public Lands: Interior... RESOURCE MANAGEMENT (2000) RIGHTS-OF-WAY UNDER THE FEDERAL LAND POLICY MANAGEMENT ACT Rents Linear Rights-Of-Way § 2806.23 How will the BLM calculate my rent for linear rights-of-way the Per Acre...

  5. 43 CFR 2806.23 - How will the BLM calculate my rent for linear rights-of-way the Per Acre Rent Schedule covers?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... linear rights-of-way the Per Acre Rent Schedule covers? 2806.23 Section 2806.23 Public Lands: Interior... RESOURCE MANAGEMENT (2000) RIGHTS-OF-WAY UNDER THE FEDERAL LAND POLICY MANAGEMENT ACT Rents Linear Rights-Of-Way § 2806.23 How will the BLM calculate my rent for linear rights-of-way the Per Acre...

  6. 43 CFR 2806.23 - How will the BLM calculate my rent for linear rights-of-way the Per Acre Rent Schedule covers?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... linear rights-of-way the Per Acre Rent Schedule covers? 2806.23 Section 2806.23 Public Lands: Interior... RESOURCE MANAGEMENT (2000) RIGHTS-OF-WAY UNDER THE FEDERAL LAND POLICY MANAGEMENT ACT Rents Linear Rights-Of-Way § 2806.23 How will the BLM calculate my rent for linear rights-of-way the Per Acre...

  7. 43 CFR 2806.23 - How will the BLM calculate my rent for linear rights-of-way the Per Acre Rent Schedule covers?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... linear rights-of-way the Per Acre Rent Schedule covers? 2806.23 Section 2806.23 Public Lands: Interior... RESOURCE MANAGEMENT (2000) RIGHTS-OF-WAY UNDER THE FEDERAL LAND POLICY MANAGEMENT ACT Rents Linear Rights-Of-Way § 2806.23 How will the BLM calculate my rent for linear rights-of-way the Per Acre...

  8. Ober's Island: The Mallard Ober's Island, One of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Ober's Island: The Mallard - Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

  9. Erosion and deterioration of Isles Dernieres Barrier Island arc, Louisiana: 1842-1988

    SciTech Connect

    McBride, R.A.; Westphal, K.; Penland, S. ); Jaffe, B. ) ); Williams, S.J. )

    1989-09-01

    The Isles Dernieres barrier island arc is the most rapidly eroding coastline in the US. Located on the Mississippi River delta plain in Terrebonne Parish, Louisiana, the Isles Dernieres consists of four smaller islands in a 32-km long chain. From west to east, these islands are known as Raccoon Island, Whiskey Island, Trinity Island, and East Island. The barrier island arc is separated from the mainland by Caillou Bay, Boca Caillou, and Lake Pelto lagoonal systems. The abandonment and transgression of the Bayou Petit Caillou delta (part of the larger Lafourche delta complex) over the last 600 years, along with sea level rise, repeated storm impacts, and rapid shoreface erosion, have led to the formation of the Isles Dernieres. Continued transgressive submergence combined with a diminishing sediment supply are driving the extreme coastal erosion found in the Isles Dernieres.

  10. Cognitive Constraints and Island Effects

    ERIC Educational Resources Information Center

    Hofmeister, Philip; Sag, Ivan A.

    2010-01-01

    Competence-based theories of island effects play a central role in generative grammar, yet the graded nature of many syntactic islands has never been properly accounted for. Categorical syntactic accounts of island effects have persisted in spite of a wealth of data suggesting that island effects are not categorical in nature and that…

  11. Willets gather in the Merritt Island National Wildlife Refuge.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Willets gather around a plant in the shallow waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Willets are best identified in flight by their black-and-white wing pattern; on the ground by their thick black bills and gray legs. They breed in southern Canada, the United States and the West Indies, wintering from the southern U.S. to central South America. The 92,000-acre refuge is a habitat for more than 330 species of birds, 31 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  12. Roseate Spoonbills preen in the Merritt Island National Wildlife Refuge.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Merritt Island National Wildlife Refuge, two roseate spoonbills mirror each other as they preen their lipstick-colored feathers. The birds, named for their brilliant pink color and paddle-shaped bill, feed in shallow water by swinging their bill back and forth, scooping up small fish and crustaceans. They typically inhabit mangroves on the coasts of southern Florida, Louisiana and Texas. The 92,000-acre refuge, which shares a boundary with Kennedy Space Center, is a habitat for more than 330 species of birds, 31 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  13. Roseate Spoonbill feeds in the Merritt Island National Wildlife Refuge.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Merritt Island National Wildlife Refuge, a roseate spoonbill searches the water for food. The birds, named for their brilliant pink color and paddle-shaped bill, feed in shallow water by swinging their bill back and forth, scooping up small fish and crustaceans. They typically inhabit mangroves on the coasts of southern Florida, Louisiana and Texas. The 92,000-acre refuge, which shares a boundary with Kennedy Space Center, is a habitat for more than 330 species of birds, 31 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  14. A roseate spoonbill in the Merritt Island National Wildlife Refuge

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A roseate spoonbill balancing on one leg is reflected in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The birds, named for their brilliant pink color and paddle-shaped bill, feed in shallow water by swinging their bill back and forth, scooping up small fish and crustaceans. They typically inhabit mangroves on the coasts of southern Florida, Louisiana and Texas. The 92,000- acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  15. Two roseate spoonbills in the Merritt Island National Wildlife Refuge

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Two roseate spoonbills wade in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The birds, named for their brilliant pink color and paddle-shaped bill, feed in shallow water by swinging their bill back and forth, scooping up small fish and crustaceans. They typically inhabit mangroves on the coasts of southern Florida, Louisiana and Texas. The 92,000-acre wildlife refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  16. A loggerhead shrike in the Merritt Island National Wildlife Refuge

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A loggerhead shrike perches on a branch in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The loggerhead shrike prefers grasslands, orchards and open areas with scattered trees throughout a range extending from southern Canada to southern Florida and the Gulf Coast. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  17. Birth of two volcanic islands in the southern Red Sea.

    PubMed

    Xu, Wenbin; Ruch, Joël; Jónsson, Sigurjón

    2015-05-26

    Submarine eruptions that lead to the formation of new volcanic islands are rare and far from being fully understood; only a few such eruptions have been witnessed since Surtsey Island emerged to the south of Iceland in the 1960s. Here we report on two new volcanic islands that were formed in the Zubair archipelago of the southern Red Sea in 2011-2013. Using high-resolution optical satellite images, we find that the new islands grew rapidly during their initial eruptive phases and that coastal erosion significantly modified their shapes within months. Satellite radar data indicate that two north-south-oriented dykes, much longer than the small islands might suggest, fed the eruptions. These events occurred contemporaneously with several local earthquake swarms of the type that typically accompany magma intrusions. Earthquake activity has been affecting the southern Red Sea for decades, suggesting the presence of a magmatically active zone that has previously escaped notice.

  18. Birth of two volcanic islands in the southern Red Sea

    PubMed Central

    Xu, Wenbin; Ruch, Joël; Jónsson, Sigurjón

    2015-01-01

    Submarine eruptions that lead to the formation of new volcanic islands are rare and far from being fully understood; only a few such eruptions have been witnessed since Surtsey Island emerged to the south of Iceland in the 1960s. Here we report on two new volcanic islands that were formed in the Zubair archipelago of the southern Red Sea in 2011–2013. Using high-resolution optical satellite images, we find that the new islands grew rapidly during their initial eruptive phases and that coastal erosion significantly modified their shapes within months. Satellite radar data indicate that two north–south-oriented dykes, much longer than the small islands might suggest, fed the eruptions. These events occurred contemporaneously with several local earthquake swarms of the type that typically accompany magma intrusions. Earthquake activity has been affecting the southern Red Sea for decades, suggesting the presence of a magmatically active zone that has previously escaped notice. PMID:26010945

  19. Islands in a European mountain river: Linkages with large wood deposition, flood flows and plant diversity

    NASA Astrophysics Data System (ADS)

    Mikuś, Paweł; Wyżga, Bartłomiej; Kaczka, Ryszard J.; Walusiak, Edward; Zawiejska, Joanna

    2013-11-01

    Vegetated islands are characteristic landforms of braided mountain rivers. Long-term observations and recent morphological and botanical surveys conducted in the gravel-bed Czarny Dunajec, Polish Carpathians, were used to determine the processes and patterns governing initiation and development of islands and their floristic complexity. Moreover, dendrochronologically estimated years of island inception were compared with the timing and magnitude of flood flows in the period 1970-2011 to infer about controls on the formation and persistence of islands in the river. In the high-energy, braided river, islands originate as a result of deposition of large vegetative particles, mostly large wood, on gravel bars and the associated vegetative regeneration of living wood or the growth of seedlings and saplings in the shelter of wood accumulations. Tree-ring dating of the largest trees growing in particular zones of building and established islands indicated a predominant upstream island growth in the river. It results from repeated accumulation of living wood on the head of islands and its subsequent regeneration and contrasts with the progressive downstream growth of islands in the rivers supplied with large, stable logs of the tree species without the capability to re-sprout. The lack of islands from the years 1982-1996 most likely reflects the removal of relatively young islands by two major floods in the 1990s which were, however, unable to destroy older and larger islands. After 1997 the occurrence of low to moderate floods facilitated the formation and persistence of islands. The plant inventory demonstrated that species richness increased non-linearly with the increasing age, area and shoreline length of islands. Islands supported more plant species than the riparian forest and attained comparable species richness at an early stage of development. Fast developing, dynamic and supporting rich plant communities, islands contribute highly to the overall floristic

  20. Magnetoelasticity in ACr2O4 spinel oxides (A= Mn, Fe, Co, Ni, and Cu)

    NASA Astrophysics Data System (ADS)

    Kocsis, V.; Bordács, S.; Varjas, D.; Penc, K.; Abouelsayed, A.; Kuntscher, C. A.; Ohgushi, K.; Tokura, Y.; Kézsmárki, I.

    2013-02-01

    Dynamical properties of the lattice structure were studied by optical spectroscopy in ACr2O4 chromium spinel oxide magnetic semiconductors over a broad temperature region of T=10-335 K. The systematic change of the A-site ions (A= Mn, Fe, Co, Ni and Cu) showed that the occupancy of 3d orbitals on the A site has strong impact on the lattice dynamics. For compounds with orbital degeneracy (FeCr2O4, NiCr2O4, and CuCr2O4), clear splitting of infrared-active phonon modes and/or activation of silent vibrational modes have been observed upon the Jahn-Teller transition and at the onset of the subsequent long-range magnetic order. Although MnCr2O4 and CoCr2O4 show multiferroic and magnetoelectric character, no considerable magnetoelasticity was found in spinel compounds without orbital degeneracy as they closely preserve the high-temperature cubic spinel structure even in their magnetic ground state. Aside from lattice vibrations, intra-atomic 3d-3d transitions of the A2+ ions were also investigated to determine the crystal field and Racah parameters and the strength of the spin-orbit coupling.

  1. [Prevalence of sexual dysfunction in primigravidae in Rio Branco, Acre State, Brazil].

    PubMed

    Lima, Adriani Castro de; Dotto, Leila Maria Geromel; Mamede, Marli Villela

    2013-08-01

    This study aimed to estimate the prevalence of sexual dysfunction prior to and during the first pregnancy. This was a cross-sectional study using postpartum interviews with 778 primigravidae who were married or in stable unions and had given birth at the two maternity hospitals in Rio Branco, Acre State, Brazil, from February 1st to July 31st, 2010. Median age was 20 years, 45% were adolescents, 19% had completed elementary school, 30% had paid jobs, and 86.5% had used public healthcare services (SUS) for childbirth. Prevalence of sexual dysfunction was 23.9% prior to pregnancy and 67.7% during pregnancy. Decreased libido was present in 20.2% prior to pregnancy and 51% during pregnancy. Decreased vaginal lubrication occurred in 29.1% during pregnancy. Dyspareunia was present in 1.2% prior to pregnancy and 14.4% during pregnancy. Some 3.3% reported sexual dissatisfaction prior to pregnancy, as compared to 10.8% during pregnancy. Women with more schooling showed higher prevalence of sexual dysfunction during (as compared to before) their first pregnancy.

  2. ACR appropriateness criteria(®) nasal cavity and paranasal sinus cancers.

    PubMed

    Siddiqui, Farzan; Smith, Richard V; Yom, Sue S; Beitler, Jonathan J; Busse, Paul M; Cooper, Jay S; Hanna, Ehab Y; Jones, Christopher U; Koyfman, Shlomo A; Quon, Harry; Ridge, John A; Saba, Nabil F; Worden, Francis; Yao, Min; Salama, Joseph K

    2017-03-01

    The American College of Radiology (ACR) Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. Here, we present the Appropriateness Criteria for cancers arising in the nasal cavity and paranasal sinuses (maxillary, sphenoid, and ethmoid sinuses). This includes clinical presentation, prognostic factors, principles of management, and treatment outcomes. Controversies regarding management of cervical lymph nodes are discussed. Rare and unusual nasal cavity cancers, such as esthesioneuroblastoma and sinonasal undifferentiated carcinomas, are included. © 2016 American College of Radiology. Head Neck, 2016 © 2016 Wiley Periodicals, Inc. Head Neck 39: 407-418, 2017.

  3. Exploring Bikeability in a Suburban Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES)

    PubMed Central

    Wahlgren, Lina; Schantz, Peter

    2014-01-01

    Background and Aim: Commuting by bicycle could contribute to public health, and route environments may influence this behaviour. Therefore, the aim of this study is to assess the potential associations between appraisals of the overall route environment as hindering or stimulating for bicycle commuting, with both perceptions of commuting route environmental factors in a suburban area and background factors. Methods: The Active Commuting Route Environment Scale (ACRES) was used for the assessment of bicycle commuters’ perceptions and appraisals of their route environments in the suburban parts of Greater Stockholm, Sweden. A simultaneous multiple regression analysis was used to assess the relationship between the outcome variable whether the overall route environment hinders or stimulates bicycle commuting and environmental factors (e.g., exhaust fumes, speeds of motor vehicles, greenery), as well as background factors (sex, age, education, income) as predictor variables. Results and Conclusions: The results indicate that in suburban areas, the factors aesthetics, greenery and bicycle paths seem to be, independently of each other, stimulating factors for bicycle commuting. On the other hand, flows of motor vehicles, noise, and low “directness” of the route seem to be hindering factors. A comparison of these results with those obtained from an inner urban area points to the importance of studying different types of built-up areas separately. PMID:25153462

  4. Actionable findings and the role of IT support: report of the ACR Actionable Reporting Work Group.

    PubMed

    Larson, Paul A; Berland, Lincoln L; Griffith, Brent; Kahn, Charles E; Liebscher, Lawrence A

    2014-06-01

    The ACR formed the Actionable Reporting Work Group to address the potential role of IT in the communication of imaging findings, especially in cases that require nonroutine communication because of the urgency of the findings or their unexpected nature. These findings that require special communication with referring clinicians are classified as "actionable findings." The work group defines 3 categories of actionable findings that require, respectively, communication and clinical decision within minutes (category 1), hours (category 2), or days (category 3). Although the work group does not believe that there can be definitive lists of such findings, it developed lists in each category that would apply in most general hospital settings. For each category, the work group discusses ways in which IT can assist interpreting radiologists in successfully communicating to the relevant clinicians to ensure optimal patient care. IT systems can also help document the communication and facilitate auditing of the documentation. The work group recommends that vendors develop platforms that can be customized on the basis of local preferences and needs. Whatever system is used, it should be highly reliable and fit seamlessly into radiologists' workflow.

  5. Stable and Metastable InGaAs/GaAs Island Shapes and Surfactant-like Suppression of the Wetting Transformation

    NASA Technical Reports Server (NTRS)

    Leon, R.; Lobo, C.; Zou, J.; Romeo, T.; Cockayne, D. J. H.

    1998-01-01

    Diverging behaviors are observed in the InGaAs/GaAs Stranski-Krastanow (S-K) island formation during vapor phase epitaxy: varying group V partial pressures gives different critical thicknesses for the onset of the S-K transformation, island surface coverages, ratios between coherent and incoherent islands, and dissimilar morphologies upon annealing.

  6. Response of Everglades tree islands to environmental change

    USGS Publications Warehouse

    Willard, Debra A.; Bernhardt, Christopher E.; Holmes, Charles W.; Landacre, Bryan; Marot, Marci E.

    2006-01-01

    Tree islands are centers of biodiversity within the Florida Everglades, USA, but the factors controlling their distribution, formation, and development are poorly understood. We use pollen assemblages from tree islands throughout the greater Everglades ecosystem to reconstruct the timing of tree island formation, patterns of development, and response to specific climatic and environmental stressors. These data indicate that fixed (teardrop-shaped) and strand tree islands developed well before substantial human alteration of the system, with initial tree island vegetation in place between 3500 and 500 calibrated years before present (cal yr BP), depending on the location in the Everglades wetland. Tree island development appears to have been triggered by regional- to global-scale climatic events at 2800 cal yr BP, 1600–1500 cal yr BP, 1200–1000 cal yr BP (early Medieval Warm Period), and 500–200 cal yr BP (Little Ice Age). These periods correspond to drought intervals documented in Central and South America and periods of southward displacement of the Intertropical Convergence Zone. The records indicate a coherence of climate patterns in both subtropical North America and the Northern Hemisphere Neotropics. Water management practices of the 20th century altered plant communities and size of tree islands throughout the Everglades. Responses range from loss of tree islands due to artificially long hydroperiods and deep water to expansion of tree islands after flow reductions. These data provide evidence for the rapidity of tree island response to specific hydrologic change and facilitate prediction of the response to future changes associated with Everglades restoration plans.

  7. Pine Island Glacier

    Atmospheric Science Data Center

    2013-04-16

    ... the open water in Pine Island Bay. To the left of the "icebergs" label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of ...

  8. Small islands adrift

    NASA Astrophysics Data System (ADS)

    Petherick, Anna

    2015-07-01

    With the charismatic former president of the Maldives, Mohamed Nasheed, behind bars on a widely derided terrorism charge, Anna Petherick asks whether small island states can really make themselves heard in Paris.

  9. "Treasure Island" and Time.

    ERIC Educational Resources Information Center

    Riach, Alan

    1996-01-01

    Examines the sense of rupture or difference inherent in children's literature between the author or adult and the reader or child, as they concern Robert Louis Stevenson's novel "Treasure Island." (TB)

  10. Belcher Islands, Canada

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Belcher Islands are an archipelago in Hudson Bay in Canada, belonging to the territory of Nunavit. The hamlet of Sanikiluaq is on the north coast of Flaherty Island. Over 1500 islands make up the archipelago. The folded sedimentary and volcanic rocks making up the islands are Proterozoic in age between 0.5 and 2.5 billion years old.

    The image mosaic was acquired 18 September 2006, covers an area of 45.7 x 113.3 km, and is located near 56.1 degrees north latitude, 79.4 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  11. Heat Island Compendium

    EPA Pesticide Factsheets

    Heat islands can be mitigated through measures like planting trees and vegetation, installing green roofs and cool roofs, and using cool pavements. The compendium describes all of these strategies and shows how communities around the country are being used

  12. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  13. Contrasting styles of Hurricane Irene washover sedimentation on three east coast barrier islands: Cape Lookout, North Carolina; Assateague Island, Virginia; and Fire Island, New York

    NASA Astrophysics Data System (ADS)

    Williams, H. F. L.

    2015-02-01

    Storm surge and wind-driven waves generated by Hurricane Irene, which made landfall on the U.S. east coast on August 27 2011, resulted in overwash of sandy barrier islands from North Carolina to New York State. Overwash has significant impacts on barrier island geomorphology: it represents a sediment pathway into island interiors, a component of island sediment budgets, and can cause considerable aggradation of backshore surfaces, important for potentially offsetting the effects of rising sea level. This study describes the morphology, texture and microfossil content of Hurricane Irene washover deposits at three contrasting barrier island sites: Cape Lookout, North Carolina, Assateague Island, Virginia and Fire Island, New York. At all three sites, run-up overwash occurred, wherein waves were sufficient to overtop parts of the beach system and transport sediment inland. However, at Fire Island, overwash was restricted by a higher elevational threshold to low spots in the beach system coinciding with pre-existing breaches in foredunes. The result was the formation of isolated, thinner, low-volume washover fans. At Assateague Island and Cape Lookout, lower elevational thresholds allowed waves to overtop longer continuous sections of beach systems, resulting in the formation of laterally-continuous, thicker, larger-volume washover terraces. Overall, the deposits lacked consistent trends in thickness and texture (such as thinning and fining inland, reflecting a progressive reduction in overwash competence). Thickness and texture of the deposits were both spatially variable and probably reflect infilling of low points on the former surface and the influence of beach and foredune sediment sources. All the washover deposits were essentially barren of foraminiferal microfossils, supporting the textural evidence that the adjacent beach and foredunes were the predominant sediment sources.

  14. Environmental Impact Statement/Environmental Impact Report for the Disposal and Reuse of Mare Island Naval Shipyard Vallejo, California. Volume 1.

    DTIC Science & Technology

    1998-04-01

    I \\ - a 11 KUW i \\13C L 4^T .Rewse Area 10. Retail/Residential (94 Acres) This reuse area , adjacent to Mare Island Strait, is bounded by the...inches by 2075 (US EPA 1995). Land subsidence is a process of settlement which lowers the land surface and can expose new areas to flood hazards...authority throughout the San Francisco Bay Area . Permit authority is derived from a combination of state and Federal legislation and can be categorized into

  15. 78 FR 58880 - Safety Zone; Catawba Island Club Wedding Event, Catawba Island Club, Catawba Island, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Catawba Island Club Wedding Event, Catawba Island Club, Catawba Island, OH ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing... Island. DATES: This rule will be effective and enforced from 7:50 p.m. until 8:30 p.m. on October 5,...

  16. Mosquito Survey, Island of Rota (Mariana Islands)

    DTIC Science & Technology

    1976-07-01

    and has also been collected from Tinfan, The adult of Aedes albopictus a severe pest and it is considered to be an important vector of dengue fever . Bionomic...evidence of local The introduction of Aedes albopictus has brought an acknowledged vector of dengue fever to the island. This is potentially...distance away from human habitation. The adults are ready biters. Medical importance: Vector of dengue fever . 2. Aedes (Stegomyia) albopictus (Skuse

  17. Anciet marble quarries in Lesvos island Greece

    NASA Astrophysics Data System (ADS)

    Mataragkas, M.; Mataragkas, D.

    2009-04-01

    ANCIENT MARBLE QUARRIES IN LESBOS ISLAND, GREECE Varti- Matarangas M.1 & Matarangas D. 1 Institute of Geological and Mining Exploration (IGME), Olympic Village, Entrance C, ACHARNAE 13677, GREECE myrsini@igme.gr , myrsini@otenet.g r A B S T R A C T Ten ancient marble quarries of Lesbos Island, most of them previously unknown, have been studied, in the frame of the research study on the ancient marble quarries in the Aegean Sea. In the present paper the geological, petrological and morphological features of the aforementioned quarries are examined. Concerning the six ancient quarries located in the areas of Tarti, Agia Paraskevi (Tsaf), Mageiras, Loutra, Latomi (Plomari) and Thermi, the authochthonous neopaleozoic unit constitutes their geological formation, while their hosting lithological formations are the included crystalline limestone lens like beds. In two ancient quarries in the areas Moria and Alyfanta, the geological formation is the authochthonous upper Triassic series and the hosting lithological formation the upper Triassic carbonate sequence, while in the areas of Akrasi-Abeliko and Karyni, the geological formation is the thrust Triassic unit and the lithological hosting formations are the included strongly deformed or not crystalline limestone lenticular beds. Furthermore, the petrographic features were also determined permitting the identification of the building stones that have been used.

  18. Direct interaction of multidrug efflux transporter AcrB and outer membrane channel TolC detected via site-directed disulfide cross-linking.

    PubMed

    Tamura, Norihisa; Murakami, Satoshi; Oyama, Yoshiaki; Ishiguro, Masaji; Yamaguchi, Akihito

    2005-08-23

    The AcrAB-TolC system exports a wide variety of drugs and toxic compounds, and confers intrinsic drug tolerance on Escherichia coli. The crystal structures suggested that AcrB and TolC directly dock with each other. However, biochemical and biophysical evidence of their interaction has been contradictory until recently. In this study, we examine the interaction sites by means of in vivo disulfide cross-linking between cysteine residues introduced by site-directed mutagenesis at the tops of the vertical hairpins of AcrB and the bottoms of the coiled coils of polyhistidine-tagged TolC molecules, which are structurally predicted docking sites. The AcrB-TolC complex formed through disulfide cross-linking was detected when a specific pair of mutants was coexpressed in E. coli. Our observations suggested that the AcrB-TolC complex may be formed through a two-step mechanism via transient tip-to-tip interaction of AcrB and TolC. The cross-linking was not affected by AcrA, the substrate, or a putative proton coupling site mutation.

  19. Role of the AcrAB-TolC efflux pump in determining susceptibility of Haemophilus influenzae to the novel peptide deformylase inhibitor LBM415.

    PubMed

    Dean, Charles R; Narayan, Shubha; Daigle, Denis M; Dzink-Fox, JoAnn L; Puyang, Xiaoling; Bracken, Kathryn R; Dean, Karl E; Weidmann, Beat; Yuan, Zhengyu; Jain, Rakesh; Ryder, Neil S

    2005-08-01

    Haemophilus influenzae isolates vary widely in their susceptibilities to the peptide deformylase inhibitor LBM415 (MIC range, 0.06 to 32 microg/ml); however, on average, they are less susceptible than gram-positive organisms, such as Staphylococcus aureus and Streptococcus pneumoniae. Insertional inactivation of the H. influenzae acrB or tolC gene in strain NB65044 (Rd strain KW20) increased susceptibility to LBM415, confirming a role for the AcrAB-TolC pump in determining resistance. Consistent with this, sequencing of a PCR fragment generated with primers flanking the acrRA region from an LBM415-hypersusceptible H. influenzae clinical isolate revealed a genetic deletion of acrA. Inactivation of acrB or tolC in several clinical isolates with atypically reduced susceptibility to LBM415 (MIC of 16 microg/ml or greater) significantly increased susceptibility, confirming that the pump is also a determinant of decreased susceptibility in these clinical isolates. Examination of acrR, encoding the putative repressor of pump gene expression, from several of these strains revealed mutations introducing frameshifts, stop codons, and amino acid changes relative to the published sequence, suggesting that loss of pump repression leads to decreased susceptibility. Supporting this, NB65044 acrR mutants selected by exposure to LBM415 at 8 microg/ml had susceptibilities to LBM415 and other pump substrates comparable to the least sensitive clinical isolates and showed increased expression of pump genes.

  20. The Holocene Isolation of Dalma Island

    NASA Astrophysics Data System (ADS)

    Lokier, Stephen

    2010-05-01

    Dalma Island can be broadly defined as an emergent salt diapir formed through the halokinetic emplacement of the Precambrian-Cambrian Hormuz Complex. The outline of the island, as seen today, has been much modified by anthropogenic dredge-and-fill activities. The lithofacies of Dalma Island can be subdivided into three distinct geological and geographical provinces. The core of the island is dominated by the sedimentary, evaporitic and volcanic lithologies of the Hormuz Complex. These chaotically distributed units are unconformably overlain by sediments and evaporites of the Miocene Fars Formation. The island's coastline is dominated by Recent bioclastic sediments, primarily derived from reefs at the island's northern coast. Following exposure of the Arabian Gulf floor during the Last Glacial Maximum, marine waters entered the Strait of Hormuz in the latest Pleistocene and the Gulf once again became a shallow epicontinental seaway. Bathymetric surveys reveal that the sea floor surrounding Dalma Island and separating it from the mainland lies at a depth shallower than 40 m. The Holocene transgression would not have had any effect on this area until after 10.2 Ka. After this time, rising ground water levels, associated with the advancing shoreline, may have resulted in the localised formation of shallow lakes or marshes in depressions. As sea level continued to rise, these lakes coalesced and the Dalma Salt Dome became increasingly isolated from the mainland. Once the transgression had reached the -15 m contour, by 8.5 Ka, Dalma would have been completely isolated from the mainland. By 6 ka sea level had reached present levels with continued rise eventually peaking between 1-2 m higher than today. At this time the area of the island would have been much reduced with wide areas of the island's low-lying coastal plain being either submerged or lying in the intertidal environment. The above figures for the isolation of Dalma make two assumptions. Firstly, it is

  1. Bidirectional ACR-NEMA interface between the VA's DHCP integrated imaging system and the Siemens-Loral PACS

    NASA Astrophysics Data System (ADS)

    Kuzmak, Peter M.; Dayhoff, Ruth E.

    1994-05-01

    At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide- range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner.

  2. Switch-Loop Flexibility Affects Transport of Large Drugs by the Promiscuous AcrB Multidrug Efflux Transporter

    PubMed Central

    Cha, Hi-jea; Müller, Reinke T.

    2014-01-01

    Multidrug efflux transporters recognize a variety of structurally unrelated compounds for which the molecular basis is poorly understood. For the resistance nodulation and cell division (RND) inner membrane component AcrB of the AcrAB-TolC multidrug efflux system from Escherichia coli, drug binding occurs at the access and deep binding pockets. These two binding areas are separated by an 11-amino-acid-residue-containing switch loop whose conformational flexibility is speculated to be essential for drug binding and transport. A G616N substitution in the switch loop has a distinct and local effect on the orientation of the loop and on the ability to transport larger drugs. Here, we report a distinct phenotypical pattern of drug recognition and transport for the G616N variant, indicating that drug substrates with minimal projection areas of >70 Å2 are less well transported than other substrates. PMID:24914123

  3. 3D structure of AcrB: the archetypal multidrug efflux transporter of Escherichia coli likely captures substrates from periplasm.

    PubMed

    Elkins, Christopher A; Nikaido, Hiroshi

    2003-02-01

    Recent advances in structural biology have extended our understanding of the multiple drug efflux complex, AcrAB-TolC, of Escherichia coli. This tripartite complex and its homologs are the major mechanisms that give most Gram-negative bacteria their characteristic intrinsic resistance to a variety of lipophilic drugs, dyes, and detergents. Most recently, the structure of the transporter AcrB was elucidated at high resolution [Nature 419(2002)587]. It is a particularly significant achievement since integral membrane proteins are notoriously elusive structures for crystallography. The striking features of this trimeric pump, such as the presence of potential substrate-binding sites in the periplasmic domain and the possibility of direct interaction with the end of TolC tunnel, refine our understanding of the mode of action of this tripartite efflux transport complex.

  4. The terrestrial and marine observations enabling historical reanalyses: the ACRE Initiative

    NASA Astrophysics Data System (ADS)

    Allan, Rob; Brohan, Philip

    2010-05-01

    Weather observations and reanalysis are perfect partners: the observations make the reanalysis possible, and the reanalysis makes optimal use of the observations in producing the comprehensive picture of the atmosphere required by both climate scientists and a host of other users. The new generation of surface-input-only reanalyses (20th Century Reanalysis Project: 1891-2006, 20th Century Reanalysis Project: 1871-2008, Surface Input Reanalysis for Climate Applications [SIRCA]: 1850-2011 and Chemical and Surface Input Reanalysis for Climate Applications [CSIRCA]: 1800-2016) therefore present both a challenge and an opportunity to observations specialists: they require an unprecedented increase in the available datasets of surface barometric pressure, sea surface temperature and sea-ice; but offer a chance to synthesise terrestrial and marine observations into a much more detailed picture of climate variability and change. The international Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative is supporting this work, both undertaking and facilitating the global recovery, imaging, digitizing, quality control and archiving of daily to sub-daily global historical terrestrial and marine surface weather observations. In this presentation, we provide an overview of the international historical terrestrial and marine data activities required to produce the quality and quantity of weather data needed in order to undertake viable historical surface-input-only historical reanalyses, ultimately extending back over the last 200 or so years. This endeavor has only been made possible because of ACRE's efforts to agglomerate a combination of the results of ongoing international data recovery initiatives, some as existing data rescue projects, and other new initiatives focusing on particular regions or countries around the world. Numerous elements and interactions are involved in such a vast enterprise, with careful consideration required in working with

  5. Improving olefin tolerance and production in E. coli using native and evolved AcrB

    SciTech Connect

    Mingardon, Florence; Clement, Camille; Hirano, Kathleen; Nhan, Melissa; Luning, Eric G.; Chanal, Angelique; Mukhopadhyay, Aindrila

    2015-01-20

    Microorganisms can be engineered for the production of chemicals utilized in the polymer industry. However many such target compounds inhibit microbial growth and might correspondingly limit production levels. Here, we focus on compounds that are precursors to bioplastics, specifically styrene and representative alpha-olefins; 1-hexene, 1-octene, and 1-nonene. We evaluated the role of the Escherichia coli efflux pump, AcrAB-TolC, in enhancing tolerance towards these olefin compounds. AcrAB-TolC is involved in the tolerance towards all four compounds in E. coli. Both styrene and 1-hexene are highly toxic to E. coli. Styrene is a model plastics precursor with an established route for production in E. coli (McKenna and Nielsen, 2011). Though our data indicates that AcrAB-TolC is important for its optimal production, we observed a strong negative selection against the production of styrene in E. coli. Thus we used 1-hexene as a model compound to implement a directed evolution strategy to further improve the tolerance phenotype towards this alpha-olefin. We focused on optimization of AcrB, the inner membrane domain known to be responsible for substrate binding, and found several mutations (A279T, Q584R, F617L, L822P, F927S, and F1033Y) that resulted in improved tolerance. Several of these mutations could also be combined in a synergistic manner. Our study shows efflux pumps to be an important mechanism in host engineering for olefins, and one that can be further improved using strategies such as directed evolution, to increase tolerance and potentially production.

  6. Role of Aspergillus niger acrA in Arsenic Resistance and Its Use as the Basis for an Arsenic Biosensor

    PubMed Central

    Choe, Se-In; Gravelat, Fabrice N.; Al Abdallah, Qusai; Lee, Mark J.; Gibbs, Bernard F.

    2012-01-01

    Arsenic contamination of groundwater sources is a major issue worldwide, since exposure to high levels of arsenic has been linked to a variety of health problems. Effective methods of detection are thus greatly needed as preventive measures. In an effort to develop a fungal biosensor for arsenic, we first identified seven putative arsenic metabolism and transport genes in Aspergillus niger, a widely used industrial organism that is generally regarded as safe (GRAS). Among the genes tested for RNA expression in response to arsenate, acrA, encoding a putative plasma membrane arsenite efflux pump, displayed an over 200-fold increase in gene expression in response to arsenate. We characterized the function of this A. niger protein in arsenic efflux by gene knockout and confirmed that AcrA was located at the cell membrane using an enhanced green fluorescent protein (eGFP) fusion construct. Based on our observations, we developed a putative biosensor strain containing a construct of the native promoter of acrA fused with egfp. We analyzed the fluorescence of this biosensor strain in the presence of arsenic using confocal microscopy and spectrofluorimetry. The biosensor strain reliably detected both arsenite and arsenate in the range of 1.8 to 180 μg/liter, which encompasses the threshold concentrations for drinking water set by the World Health Organization (10 and 50 μg/liter). PMID:22467499

  7. Role of Aspergillus niger acrA in arsenic resistance and its use as the basis for an arsenic biosensor.

    PubMed

    Choe, Se-In; Gravelat, Fabrice N; Al Abdallah, Qusai; Lee, Mark J; Gibbs, Bernard F; Sheppard, Donald C

    2012-06-01

    Arsenic contamination of groundwater sources is a major issue worldwide, since exposure to high levels of arsenic has been linked to a variety of health problems. Effective methods of detection are thus greatly needed as preventive measures. In an effort to develop a fungal biosensor for arsenic, we first identified seven putative arsenic metabolism and transport genes in Aspergillus niger, a widely used industrial organism that is generally regarded as safe (GRAS). Among the genes tested for RNA expression in response to arsenate, acrA, encoding a putative plasma membrane arsenite efflux pump, displayed an over 200-fold increase in gene expression in response to arsenate. We characterized the function of this A. niger protein in arsenic efflux by gene knockout and confirmed that AcrA was located at the cell membrane using an enhanced green fluorescent protein (eGFP) fusion construct. Based on our observations, we developed a putative biosensor strain containing a construct of the native promoter of acrA fused with egfp. We analyzed the fluorescence of this biosensor strain in the presence of arsenic using confocal microscopy and spectrofluorimetry. The biosensor strain reliably detected both arsenite and arsenate in the range of 1.8 to 180 μg/liter, which encompasses the threshold concentrations for drinking water set by the World Health Organization (10 and 50 μg/liter).

  8. Pharmacokinetic-pharmacodynamic modeling of fostamatinib efficacy on ACR20 to support dose selection in patients with rheumatoid arthritis (RA).

    PubMed

    Maringwa, John; Kågedal, Matts; Hamrén, Ulrika Wählby; Martin, Paul; Cox, Eugène; Hamrén, Bengt

    2015-03-01

    R788 (fostamatinib) is an oral prodrug that is rapidly converted into a relatively selective spleen tyrosine kinase (SYK) inhibitor R406, evaluated for the treatment of rheumatoid arthritis (RA). This analysis aimed at developing a pharmacodynamic model for efficacy using pooled ACR20 data from two phase II studies in patients with rheumatoid arthritis (TASKi1 and TASKi2), describing the effect of fostamatinib as a function of fostamatinib exposure (dose, R406 plasma concentration) and other explanatory variables. The exposure-response relationship of fostamatinib was implemented into a continuous time Markov model describing the time course of transition probabilities between the three possible states of ACR20 non-responder, responder, and dropout at each visit. The probability of transition to the ACR20 response state was linearly (at the rate constant level) related to average R406 plasma concentrations and the onset of this drug effect was fast. Further, increases of fostamatinib dose resulted in increased dropout and subsequent loss of efficacy. This analysis provided an increased understanding of the exposure-response relationship, and provided support for fostamatinib 100 mg BID an appropriate dose regimen for further clinical evaluation.

  9. Hydrologic effects of annually diverting 131,000 acre-feet of water from Dillon Reservoir, central Colorado

    USGS Publications Warehouse

    Alley, William M.; Bauer, D.P.; Veenhuis, J.E.; Brennan, Robert

    1979-01-01

    Because of the increased demands for water in eastern Colorado, principally in the urbanizing Denver metropolitan area, increased diversions of water from Dillon Reservoir are planned. Estimates of end-of-month storage in Dillon Reservoir, assuming the reservoir was in place and 131,000 acre-feet of water were diverted from the reservoir each year, were reconstructed by mass balance for the 1931-77 water years. Based on the analysis, the annual maximum end-of-month drawdown below the elevation at full storage would have averaged 54 feet. The maximum end-of-month drawdown below the elevation at full storage would have been 171 feet. The mean-annual discharge-weighted dissolved-solids concentrations in the Colorado River near Glenwood Springs and Cameo, Colo., and Cisco, Utah, for the 1942-77 water years, were computed assuming an annual diversion of 131,000 acre-feet of water from Dillon Reservoir. The average increases in the dissolved-solids concentrations with the 131 ,000-acre-foot diversion were 15 to 16 milligrams per liter at the three sites. (Woodard-USGS)

  10. The ACR20 and defining a threshold for response in rheumatic diseases: too much of a good thing.

    PubMed

    Felson, David T; LaValley, Michael P

    2014-01-03

    In the past 20 years great progress has been made in the development of multidimensional outcome measures (such as the Disease Activity Score and ACR20) to evaluate treatments in rheumatoid arthritis, a process disseminated throughout rheumatic diseases. These outcome measures have standardized the assessment of outcomes in trials, making it possible to evaluate and compare the efficacy of treatments. The methodologic advances have included the selection of pre-existing outcome measures that detected change in a sensitive fashion (in rheumatoid arthritis, this was the Core Set Measures). These measures were then combined into a single multidimensional outcome measure and such outcome measures have been widely adopted in trials and endorsed by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) and regulatory agencies. The secular improvement in treatment for patients with rheumatoid arthritis has been facilitated in part by these major methodologic advancements. The one element of this effort that has not optimized measurement of outcomes nor made it easier to detect the effect of treatments is the dichotomization of continuous measures of response, creating responders and non-responder definitions (for example, ACR20 responders; EULAR good responders). Dichotomizing response sacrifices statistical power and eliminates variability in response. Future methodologic work will need to focus on improving multidimensional outcome measurement without arbitrarily characterizing some patients as responders while labeling others as non-responders.

  11. Modeling Catastrophic Barrier Island Dynamics

    NASA Astrophysics Data System (ADS)

    Whitley, J. W.; McNamara, D.

    2012-12-01

    Barrier islands, thin strips of sand lying parallel to the mainland coastline, along the U.S. Atlantic and Gulf Coasts appear to have maintained their form for thousands of years in the face of rising sea level. The mechanisms that allow barrier islands to remain robust are transport of sediment from the ocean side of barriers to the top and backside during storms, termed island overwash, and the growth and alongshore propagation of tidal deltas near barrier island inlets. Dynamically these processes provide the necessary feedbacks to maintain a barrier island in an attractor that withstands rising sea level within a phase space of barrier island geometrical characteristics. Current barrier island configurations along the Atlantic and Gulf coasts exist among a wide range of storm climate and underlying geologic conditions and therefore the environment that forces overwash and tidal delta dynamics varies considerably. It has been suggested that barrier islands in certain locations such as those between Avon and Buxton (losing 76% of island width since 1852) and Chandeleur islands (losing 85% of its surface area since 2005) along the Atlantic and Gulf coasts, respectively, may be subject to a catastrophic shift in barrier island attractor states - more numerous inlets cutting barriers in some locations and the complete disappearance of barrier islands in other locations. In contrast to common models for barrier islands that neglect storm dynamics and often only consider cross-shore response, we use an alongshore extended model for barrier island dynamics including beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms to explore the response of barrier islands to a wide range of environmental forcing. Results will be presented that show how barrier island attractor states are altered with variations in the rate of sea level rise, storminess, and underlying geology. We will

  12. Hydrogeology of the Galapagos Islands

    NASA Astrophysics Data System (ADS)

    D'Ozouville, N.; Pryet, A.; Violette, S.; de Marsily, G.; Deffontaines, B.; Auken, E.

    2010-12-01

    Due to the heterogeneity of geological formations, volcanic islands present complex and contrasting hydrogeological settings. A young discipline in the Galapagos, hydrogeology requires an understanding of geology, geomorphology, climate and hydrology. Throughout history, navigators, scientists and inhabitants noted the lack of surface freshwater; and water availability limited settlement of the islands. Today, this limitation is overcome through groundwater exploitation and expensive desalination, fed by economic growth. This shift has freed the field of hydrogeology from the existing premise of water being the principal drive for human development. Within this context, our approach is to lead a pluri-disciplinary research to characterize Galapagos hydrogeology. It involves a long-term commitment with international, national and local partners. Field investigations conducted on the inhabited islands of Santa Cruz, San Cristobal, Isabela and Floreana reveal three types of aquifers. A low-lying basal aquifer outcrops on Santa Cruz and Isabela. Due to the high permeability of fractured shield series forming coastal aprons, intruding sea water mixes with discharging freshwater, and confers a high salt content to groundwater. In order to characterize the hydraulic properties of this aquifer, the propagation of the tidal signal into the basal aquifer has been investigated through piezometric monitoring in three open coastal fractures and the deep well on Santa Cruz. Springs are scarce in the Archipelago, but have been identified historically on Santa Cruz and Floreana, located on the flanks of volcanic cones, and fed by small perched aquifers. On San Cristobal, high-level aquifers feed springs on the southern mountainside that contribute to a network of permanent rivers that reach the sea, a unique feature in the whole archipelago. They are independent from El Junco, a unique summital freshwater, and semi-endoreic lake. Internal resistivity structure of Santa Cruz and

  13. Heron Island, Australia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

  14. Habitat and environment of islands: primary and supplemental island sets

    USGS Publications Warehouse

    Matalas, Nicholas C.; Grossling, Bernardo F.

    2002-01-01

    The original intent of the study was to develop a first-order synopsis of island hydrology with an integrated geologic basis on a global scale. As the study progressed, the aim was broadened to provide a framework for subsequent assessments on large regional or global scales of island resources and impacts on those resources that are derived from global changes. Fundamental to the study was the development of a comprehensive framework?a wide range of parameters that describe a set of 'saltwater' islands sufficiently large to Characterize the spatial distribution of the world?s islands; Account for all major archipelagos; Account for almost all oceanically isolated islands, and Account collectively for a very large proportion of the total area of the world?s islands whereby additional islands would only marginally contribute to the representativeness and accountability of the island set. The comprehensive framework, which is referred to as the ?Primary Island Set,? is built on 122 parameters that describe 1,000 islands. To complement the investigations based on the Primary Island Set, two supplemental island sets, Set A?Other Islands (not in the Primary Island Set) and Set B?Lagoonal Atolls, are included in the study. The Primary Island Set, together with the Supplemental Island Sets A and B, provides a framework that can be used in various scientific disciplines for their island-based studies on broad regional or global scales. The study uses an informal, coherent, geophysical organization of the islands that belong to the three island sets. The organization is in the form of a global island chain, which is a particular sequential ordering of the islands referred to as the 'Alisida.' The Alisida was developed through a trial-and-error procedure by seeking to strike a balance between 'minimizing the length of the global chain' and 'maximizing the chain?s geophysical coherence.' The fact that an objective function cannot be minimized and maximized simultaneously

  15. Maintenance of biodiversity on islands.

    PubMed

    Chisholm, Ryan A; Fung, Tak; Chimalakonda, Deepthi; O'Dwyer, James P

    2016-04-27

    MacArthur and Wilson's theory of island biogeography predicts that island species richness should increase with island area. This prediction generally holds among large islands, but among small islands species richness often varies independently of island area, producing the so-called 'small-island effect' and an overall biphasic species-area relationship (SAR). Here, we develop a unified theory that explains the biphasic island SAR. Our theory's key postulate is that as island area increases, the total number of immigrants increases faster than niche diversity. A parsimonious mechanistic model approximating these processes reproduces a biphasic SAR and provides excellent fits to 100 archipelago datasets. In the light of our theory, the biphasic island SAR can be interpreted as arising from a transition from a niche-structured regime on small islands to a colonization-extinction balance regime on large islands. The first regime is characteristic of classic deterministic niche theories; the second regime is characteristic of stochastic theories including the theory of island biogeography and neutral theory. The data furthermore confirm our theory's key prediction that the transition between the two SAR regimes should occur at smaller areas, where immigration is stronger (i.e. for taxa that are better dispersers and for archipelagos that are less isolated).

  16. Archaeoastronomy of Easter Island

    NASA Astrophysics Data System (ADS)

    Edwards, Edmundo

    Astronomer priests or "skywatchers" on Easter Island lived in stone towers that were used as observatories and built stone markers in the periphery that indicated the heliacal rising of certain stars that served to indicate the arrival of marine birds, turtles, the offshore fishing season, and times for planting and harvest. Petroglyphs related to such sites depict outriggers, fishhooks, pelagic fish, and turtles and supposedly represented a star map. In this chapter, we analyze a set of such skywatchers dwellings, and stone markers located upon the North coast of Easter Island that have astronomic orientations, its related petroglyphs, and the relations between these directions with their yearly activities and their ritual calendar.

  17. Long Island Solar Farm

    SciTech Connect

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  18. Sakhalin Island terrain intelligence

    USGS Publications Warehouse

    ,

    1943-01-01

    This folio of maps and explanatory tables outlines the principal terrain features of Sakhalin Island. Each map and table is devoted to a specialized set of problems; together they cover the subjects of terrain appreciation, climate, rivers, water supply, construction materials, suitability for roads, suitability for airfields, fuels and other mineral resources, and geology. In most cases, the map of the island is divided into two parts: N. of latitude 50° N., Russian Sakhalin, and south of latitude 50° N., Japanese Sakhalin or Karafuto. These maps and data were compiled by the United States Geological Survey during the period from March to September, 1943.

  19. Comparison of carcass yields and meat quality between Baicheng-You chickens and Arbor Acres broilers.

    PubMed

    Sarsenbek, A; Wang, T; Zhao, J K; Jiang, W

    2013-10-01

    This study examined carcass yields and meat quality traits between Baicheng-You (BCY) chickens and Arbor Acres (AA) broilers. Thirty birds for each strain were selected and slaughtered at market ages of 49 d for AA broilers and 120 d for BCY. The results showed that BCY chickens had lower dressing (2.99%), semi-evisceration (5.10%), breast muscle (5.80%), and abdominal fat (1.55%) than those for AA broilers (P < 0.05). However, the leg muscle (%) of BCY chickens was greater (3.14%) than that of AA broilers (P < 0.05). The meat pH45min and pH24h value variations of these 2 breeds were within the normal range (5.53-6.70). The meat color density (optical density, OD) of thigh muscle was darker than breast muscles in both strains (P < 0.05). The cooking loss (%) of breast and thigh muscles of BCY chickens (18.81 and 20.20%, respectively) was also significantly lower (P < 0.05) than that of same muscles of AA broilers (26.41 and 27.33%, respectively). The shear force of breast meat in both breeds was lower (P < 0.05) than that of their thigh meat. The moisture of breast muscle of BCY chickens (72.93%) was lower (P < 0.05) than breast muscles of AA broilers (74.43%). The CP content of breast muscles was greater (P < 0.05) than its thigh muscles of same strain, but it had no significant (P > 0.05) difference of CP content in the same muscles of the 2 strains. The intramuscular fat (IMF) content was greater (P < 0.05) in thigh muscles of BCY chickens (6.80%) than those of AA broilers (4.28%), and inosine-5'-monophosphate (IMP) content was greater (P < 0.05) in breast and thigh muscles of BCY chickens (IMP: 3.79 and 1.47 mg/g) than same muscles in AA broilers (1.42 and 0.47 mg/g). In this study, muscle from 120-d-old BCY chickens was judged to have better quality traits with regard to cooking loss, drip loss, contents of IMF, and IMP compared with meat from 42-d-old AA broilers. At the same time, greater carcass yields, greater thigh pH24, and lower IMF content were

  20. Tensile strained island growth at step-edges on GaAs(110)

    SciTech Connect

    Simmonds, P. J.; Lee, M. L.

    2010-10-11

    We report the growth of tensile strained GaP islands on a GaAs(110) surface. Three-dimensional island formation proceeds via a step-edge nucleation process. To explain the dislocation-free nature of these islands, we consider the kinetics of strain relief within the context of a model for dislocation glide as a function of surface orientation and sign of strain.