Now showing items 433-452 of 803

  • A manganese-rich environment supports superoxide dismutase activity in a lyme disease pathogen, Borrelia burgdorferi 

    Aguirre, J. Dafhne; Clark, Hillary M.; McIlvin, Matthew R.; Vazquez, Christine; Palmere, Shaina L.; Grab, Dennis J.; Seshu, J.; Hart, P. John; Saito, Mak A.; Culotta, Valeria C. (2013-01-28)
    The Lyme disease pathogen Borrelia burgdorferi represents a novel organism in which to study metalloprotein biology in that this spirochete has uniquely evolved with no requirement for iron. Not only is iron low, but we ...
  • Mantle 3He distribution and deep circulation in the Indian Ocean 

    Srinivasan, Ashwanth; Top, Zafer; Schlosser, Peter; Hohmann, Roland; Iskandarani, Mohamed; Olson, Donald B.; Lupton, John E.; Jenkins, William J. (American Geophysical Union, 2004-06-10)
    The World Ocean Circulation Experiment Indian Ocean helium isotope data are mapped and features of intermediate and deep circulation are inferred and discussed. The 3He added to the deep Indian Ocean originates from (1) a ...
  • The marine biogeochemistry of dissolved and colloidal Iron 

    Fitzsimmons, Jessica N. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-09)
    Iron is a redox active trace metal micronutrient essential for primary production and nitrogen acquisition in the open ocean. Dissolved iron (dFe) has extremely low concentrations in marine waters that can drive phytoplankton ...
  • The marine biogeochemistry of zinc isotopes 

    John, Seth G. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-06)
    Zinc (Zn) stable isotopes can record information about important oceanographic processes. This thesis presents data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, ...
  • Marine ecosystem dynamics and biogeochemical cycling in the Community Earth System Model [CESM1(BGC)] : comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 scenarios 

    Moore, J. Keith; Lindsay, Keith; Doney, Scott C.; Long, Matthew C.; Misumi, Kazuhiro (American Meteorological Society, 2013-12-01)
    The authors compare Community Earth System Model results to marine observations for the 1990s and examine climate change impacts on biogeochemistry at the end of the twenty-first century under two future scenarios ...
  • The marine geochemistry of iron and iron isotopes 

    Bergquist, Bridget A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2004-09)
    This thesis addressed questions about the Fe cycle by measuring detailed profiles and transects of Fe species in the ocean and also by exploring the use of a new tracer of Fe, Fe isotopic fractionation. In the subtropical ...
  • The marine geochemistry of methane 

    Scranton, Mary Isabelle (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1977-08)
    In the highly productive coastal surface waters near Walvis Bay, methane is present in concentrations considerably above those which would be predicted from solubility equilibrium with the atmosphere. A one dimensional ...
  • The marine geochemistry of the rare earth elements 

    Baar, Hein J. W. de (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983-09)
    Novel methods were developed for the determination of 12 of the 14 Rare Earth Elements (REE) in seawater. Initial extractions of the REE by chelating ion exchange chromatography is followed by cation exchange for removal ...
  • The marine geochemistry of thorium and protactinium 

    Anderson, Robert F. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-11)
    Suspended particulate matter was collected by sediment traps deployed in the Sargasso Sea (Site S2), the north equatorial Atlantic (Site E), the north equatorial Pacific (Site P), and the Panama Basin (STIE Site). Additional ...
  • The marine geochemistry of trace metals 

    Boyle, Edward A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1976-04)
    The marine geochemical cycles of iron, copper, nickel, and cadmium were studied in order to provide a basis for oceanographic models for trace metals. Copper, nickel, and cadmium can be determined in a 100 ml seawater ...
  • The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States : insights from a transregional coastal carbon study 

    Wang, Zhaohui Aleck; Wanninkhof, Rik; Cai, Wei-Jun; Byrne, Robert H.; Hu, Xinping; Peng, Tsung-Hung; Huang, Wei-Jen (Association for the Sciences of Limnology and Oceanography, 2013-01)
    Distributions of total alkalinity (TA), dissolved inorganic carbon (DIC), and other parameters relevant to the marine inorganic carbon system were investigated in shelf and adjacent ocean waters during a U.S. Gulf of Mexico ...
  • Marine microbial intact polar diacylglycerolipids and their application in the study of nutrient stress and bacterial production 

    Popendorf, Kimberly J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-02)
    Intact polar diacylglycerolipids (IP-DAGs) were used to study microbial dynamics in the surface ocean. IP-DAGs from surface ocean seawater were quantified using high performance liquid chromatography-mass spectrometry ...
  • Marine microbial production of dimethylsulfide from dissolved dimethylsulfoniopropionate 

    Ledyard, Kathleen Mei (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-02)
    Dimethylsulfide (DMS) plays a central role in the transfer of sulfur from the ocean to the atmosphere, and ultimately to land. The most abundant volatile organosulfur compound in seawater, DMS is believed to account for ...
  • Marine particle dynamics : sinking velocities, size distributions, fluxes, and microbial degradation rates 

    McDonnell, Andrew M. P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-02)
    The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements ...
  • Marine sedimentary organic matter : delineation of marine and terrestrial sources through radiocarbon dating; and the role of organic sulfur in early petroleum generation 

    Benitez-Nelson, Bryan C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-05)
    This thesis details two years of research conducted with the guidance and support of three advisors: Dr. J. K. Whelan, Dr. J. S. Seewald and Dr. T. I. Eglinton. Each of the three chapters represents a different, ...
  • Marine-derived C-14 calibration and activity record for the past 50,000 years updated from the Cariaco Basin 

    Hughen, Konrad A.; Southon, John R.; Lehman, Scott J.; Bertrand, Chanda J. H.; Turnbull, J. (2006-03-01)
    An expanded Cariaco Basin 14C chronology is tied to 230Th-dated Hulu Cave speleothem records in order to provide detailed marine-based 14C calibration for the past 50,000 years. The revised, high resolution Cariaco 14C ...
  • Marine04 marine radiocarbon age calibration, 0-26 cal kyr BP 

    Hughen, Konrad A.; Baillie, Mike G. L.; Bard, Edouard; Beck, J. Warren; Bertrand, Chanda J. H.; Blackwell, Paul G.; Buck, Caitlin E.; Burr, George S.; Cutler, Kirsten B.; Damon, Paul E.; Edwards, R. Lawrence; Fairbanks, Richard G.; Friedrich, Michael; Guilderson, Thomas P.; Kromer, Bernd; McCormac, Gerry; Manning, Sturt; Ramsey, C. Bronk; Reimer, Paula J.; Reimer, Ron W.; Remmele, Sabine; Southon, John R.; Stuiver, Minze; Talamo, Sahra; Taylor, F. W.; van der Plicht, Johannes; Weyhenmeyer, Constanze E. (Dept. of Geosciences, University of Arizona, 2004)
    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional ...
  • Mariprofundus ferrooxydans PV-1 the First Genome of a Marine Fe(II) Oxidizing Zetaproteobacterium 

    Singer, Esther; Emerson, David; Webb, Eric A.; Barco, Roman A.; Kuenen, J. Gijs; Nelson, William C.; Chan, Clara S.; Comolli, Luis R.; Ferriera, Steve; Johnson, Justin; Heidelberg, John F.; Edwards, Katrina J. (Public Library of Science, 2011-09-23)
    Mariprofundus ferrooxydans PV-1 has provided the first genome of the recently discovered Zetaproteobacteria subdivision. Genome analysis reveals a complete TCA cycle, the ability to fix CO2, carbon-storage proteins and a ...
  • Measuring xCO₂ using the CAT/NDIR method system set up, calibration, maintenance and shutdown 

    Tracy, Maren E.; Peltzer, Edward T.; Goyet, Catherine (Woods Hole Oceanographic Institution, 1994-02)
    Accurate measurement of partial pressure of CO2 in seawater is currently performed by measuring pC02 in an aliquot of a small volume of gas equilibrated with a large volume of the seawater to be measured. PC02 in the gas ...