Author: Elizabeth B. Kujawinski
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 734
Book Description
(Cont.) surface-active material in ciliate cultures was significantly higher than in flagellate cultures, and all protozoan cultures were higher than the bacterial control. Common headspace vessels were then used to compare and contrast the affinity of protozoan and bacterial culture filtrates (
The Effect of Protozoan Grazers on the Cycling of Polychlorinated Biphenyls (PCBs) in Marine Systems
Author: Elizabeth B. Kujawinski
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 734
Book Description
(Cont.) surface-active material in ciliate cultures was significantly higher than in flagellate cultures, and all protozoan cultures were higher than the bacterial control. Common headspace vessels were then used to compare and contrast the affinity of protozoan and bacterial culture filtrates (
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 734
Book Description
(Cont.) surface-active material in ciliate cultures was significantly higher than in flagellate cultures, and all protozoan cultures were higher than the bacterial control. Common headspace vessels were then used to compare and contrast the affinity of protozoan and bacterial culture filtrates (
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 426
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 426
Book Description
The Biogeochemistry of Iron in Seawater
Author: David R. Turner
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 426
Book Description
Intensive research carried out during the 1990's (known as the "Iron Age of Oceanography") provided a wealth of new information and this title, written by acknowledged experts and reviewed by international specialists, provides the authoritative and comprehensive review of the subject area. A joint venture between SCOR and IUPAC, it expertly addresses the current state of knowledge of the biogeochemistry of iron in seawater and covers: * Chemical speciation * Analytical techniques * Transformation of iron * It includes evidence for iron limitation of primary production of High Nutrient Low Chlorophyll (HNLC) areas in the ocean * Structured into a series of chapters it has been reviewed by international specialists- SCOR (Scientific Committee for Ocean Research) and IUPAC (International Union for Pure and Applied Chemistry) * The final chapter summarises the conclusions of the book and discusses the priorities for future research * Ideal for scientists studying the environmental impact of metals and their role in marine ecosystems; Marine Scientists and Oceanographers; Environmental Analytical Chemists
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 426
Book Description
Intensive research carried out during the 1990's (known as the "Iron Age of Oceanography") provided a wealth of new information and this title, written by acknowledged experts and reviewed by international specialists, provides the authoritative and comprehensive review of the subject area. A joint venture between SCOR and IUPAC, it expertly addresses the current state of knowledge of the biogeochemistry of iron in seawater and covers: * Chemical speciation * Analytical techniques * Transformation of iron * It includes evidence for iron limitation of primary production of High Nutrient Low Chlorophyll (HNLC) areas in the ocean * Structured into a series of chapters it has been reviewed by international specialists- SCOR (Scientific Committee for Ocean Research) and IUPAC (International Union for Pure and Applied Chemistry) * The final chapter summarises the conclusions of the book and discusses the priorities for future research * Ideal for scientists studying the environmental impact of metals and their role in marine ecosystems; Marine Scientists and Oceanographers; Environmental Analytical Chemists
Cell Cycle Dynamics and the Physiology of Saxitoxin Biosynthesis in Alexandrium Fundyense (Dinophyceae)
Author: Gaspar Taroncher Oldenburg
Publisher:
ISBN:
Category : Biology
Languages : en
Pages : 738
Book Description
Marine dinoflagellates in the genus Alexandrium synthesize Saxitoxin (STX) and several of its derivatives. The aim of this thesis was to analyze novel aspects of toxigenesis and the cell cycle in Alexandrium and to apply molecular techniques to gain new insights on the regulation of STX biosynthesis. Synchronized cultures of A. fundyense were studied to determine the dynamics of toxin production throughout the cell cycle. STX biosynthesis was shown to be discontinuous and constrained to approximately 10 hours at the beginning of G1. Two cell cycle transition points were identified: a light-dependent one and a size-dependent one. Semi-continuous cultures of A. fundyense were used to determine the effects of temperature and phosphate limitation on the coupling of STX biosynthesis to O%. Inferred toxin production rates were constant and correlated to G1 over a range of growth rates. The effects of phosphate on STX biosynthesis were analyzed and a scheme of interconversions among STX derivatives is proposed. Differential Display (DD) analysis was applied to the identification of up- or downregulated genes during toxigenesis in A. fundyense. The expression patterns of S-adenosylhomocysteine hydrolase, methionine aminopeptidase and a histone-like protein were related to periods of STX biosynthesis.
Publisher:
ISBN:
Category : Biology
Languages : en
Pages : 738
Book Description
Marine dinoflagellates in the genus Alexandrium synthesize Saxitoxin (STX) and several of its derivatives. The aim of this thesis was to analyze novel aspects of toxigenesis and the cell cycle in Alexandrium and to apply molecular techniques to gain new insights on the regulation of STX biosynthesis. Synchronized cultures of A. fundyense were studied to determine the dynamics of toxin production throughout the cell cycle. STX biosynthesis was shown to be discontinuous and constrained to approximately 10 hours at the beginning of G1. Two cell cycle transition points were identified: a light-dependent one and a size-dependent one. Semi-continuous cultures of A. fundyense were used to determine the effects of temperature and phosphate limitation on the coupling of STX biosynthesis to O%. Inferred toxin production rates were constant and correlated to G1 over a range of growth rates. The effects of phosphate on STX biosynthesis were analyzed and a scheme of interconversions among STX derivatives is proposed. Differential Display (DD) analysis was applied to the identification of up- or downregulated genes during toxigenesis in A. fundyense. The expression patterns of S-adenosylhomocysteine hydrolase, methionine aminopeptidase and a histone-like protein were related to periods of STX biosynthesis.
Annual Report
Author: Woods Hole Oceanographic Institution
Publisher:
ISBN:
Category : Marine biology
Languages : en
Pages : 322
Book Description
Publisher:
ISBN:
Category : Marine biology
Languages : en
Pages : 322
Book Description
Biological/Chemical Oceanography Program Abstract Book
Direct and Indirect Photoreactions of Chromophoric Dissolved Organic Matter
Author: Jared Verrill Goldstone
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 278
Book Description
Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02- ) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 278
Book Description
Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02- ) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.
American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 848
Book Description
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 848
Book Description
Applied and Environmental Microbiology
Organic Ligands in Marine Trace Metal Biogeochemistry
Author: Kristen N. Buck
Publisher: Frontiers Media SA
ISBN: 2889453766
Category :
Languages : en
Pages : 305
Book Description
This research topic highlights the most recent accomplishments of a Scientific Committee on Oceanic Research (SCOR) Working Group, SCOR WG 139: Organic Ligands - A Key Control on Trace Metal Biogeochemistry in the Ocean.
Publisher: Frontiers Media SA
ISBN: 2889453766
Category :
Languages : en
Pages : 305
Book Description
This research topic highlights the most recent accomplishments of a Scientific Committee on Oceanic Research (SCOR) Working Group, SCOR WG 139: Organic Ligands - A Key Control on Trace Metal Biogeochemistry in the Ocean.