BCO-DMO ERDDAP
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Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL access_formats String .htmlTable,.csv,.json,.mat,.nc,.tsv
attribute NC_GLOBAL acquisition_description String Radiolabeled Diatom Cultures  \n Natural seawater with a salinity of 35, collected from the Gulf of Mexico,\nwas sequentially filtered through a  \n 0.2 \\u03bcm polycarbonate cartridge and ultrafiltered with a 1000 amu cutoff\nmembrane to remove particulate  \n and colloidal organic matter [Guo et al., 1995; Roberts et al., 2009]. The\n<1000 amu ultrafiltrate fraction was  \n then used for later experiments. The 234Th tracer was milked and purified\nfrom a 238U solution [Alvarado  \n Quiroz et al., 2006; Quigley et al., 2002]; 233Pa, in equilibrium with\n237Np, was obtained from Pacific Northwest  \n National Laboratory; 210Pb, in 1 mol L-1 nitric acid (HNO3), was purchased\nfrom Eckert & Ziegler Isotope  \n Products, and the 7Be tracer solution (in 0.1 mol L-1 hydrochloric acid,\nHCl) was manufactured at the Paul  \n Scherrer Institute, Switzerland [Schumann et al., 2013].  \n Autoclaved f/2 media (50 ml) were added to preconditioned clear polyethylene\ncontainers, and then ~10 to  \n 15 Bq of each radionuclide tracer (234Th, 233Pa, 210Pb, and 7Be) was added.\nIn each radiolabeled medium, 1ml  \n of laboratory axenic culture, Phaeodactylum tricornutum (UTEX 646), was then\nadded and incubated at a temperature of 19 \\u00b1 1\\u00b0C with a light:dark\ncycle of 14 h:10 h under an irradiance of 100 \\u03bcmol quanta m-2 s-1.  \n Incubation experiments were carried out in duplicate. The growth status of\nP. tricornutum was monitored  \n by changes in optical density at 750nm (OD750) in a parallel nonlabeled\nculture. When P. tricornutum reached the stationary phase observed by its\nOD750, cells were harvested for further extraction and analyses. The total\nincubation  \n time was 35 days.  \n Exopolymeric Substance (AEPS and NAEPS) Extraction  \n AEPS and NAEPS extractions were performed following the procedures described\nin Chuang et al. [2014, 2015]. Briefly, for NAEPS, laboratory cultures were\ncentrifuged (2694 g, 30 min) and filtered (0.2 \\u03bcm). The filtrate was\ndesalted via diafiltration with a 1000 amu cutoff cross-flow ultrafiltration\nmembrane, followed by freeze drying  \n for later use. For the AEPS extraction, diatom cells were collected after\ncentrifugation from the previous step. Then,  \n the pellet was soaked with 0.5mol L -1\\u00a0 sodium chloride (NaCl) solution\nfor 10 min, followed by centrifugation at  \n 2000 g for 15 min to remove the medium and weakly bound organic material on\nthe cells. The pellet was  \n then resuspended in a fresh 100 ml, 0.5mol L-1 NaCl solution and stirred\ngently overnight at 4\\u00b0C. The resuspended  \n particle solution was ultracentrifuged at 12,000 g (30 min, 4\\u00b0C), and\nthe supernatant was then filtered through a 0.2 \\u03bcm polycarbonate\nmembrane. The filtrate was further desalted via diafiltration with a 1000 amu\ncutoff ultrafiltration membrane and subsequently freeze dried for later\nuse.\\u00a0\n \nIntracellular and Frustule BF Extraction  \n Procedures for frustule biopolymers extraction adapted from Scheffel et al.\n[2011]. Briefly, the  \n clean diatom cells from the previous AEPS extraction step were resuspended\nin 10 ml, 100mmol L-1 EDTA  \n (pH 8.0) at 4\\u00b0C overnight. EDTA solution was used to extract the\nintracellular material after cell lysis. The supernatant  \n was collected after centrifuging at 3000 g for 10 min, defined as EDTA\nextractable BF. Subsequently,  \n the pellet was placed in 10 ml, 1% SDS in 10mmol L-1 Tris (pH 6.8) solution\nand heated at 95\\u00b0C for 1 h.  \n The resulting frustules were collected by centrifugation (2500 g, 10 min),\nwashed with 10 ml milli-Q water 3  \n times, and then were freeze dried for later use. The supernatant from this\nstep was collected and defined  \n as SDS extractable BF, mostly composed of soluble cell-membrane-associated\nmaterials. These two fractions  \n represent intracellular biopolymers lysed after cell breakage.\n \nHF digestion was applied to help extract the diatom frustule biopolymers. HF\nis a nonoxidizing acid commonly  \n used to convert SiO2 to volatile SiF4 during wet digestion [Scheffel et al.,\n2011; \\u0160ulcek and Povondra,  \n 1989]. Hence, frustule biopolymers could be separated from the digested\nsolution by a 3 kDa cutoff membrane. However, high-concentration HF would also\nliberate A type metal radionuclides (Th, Pa, and Be in  \n this study) from any complex by frustule biopolymers [e.g., Burnett et al.,\n1997]. Furthermore, deglycosylation  \n might also have occurred during a HF digestion [Mort and Lamport, 1977].\nTherefore, the <3000 amu fraction  \n represents the sum of silica frustules and broken down frustule biopolymer\nresidues.\n \nSubsequently, 5 ml, 52% HF was added to the frustules in a 15ml plastic\ncentrifugation tube, and the mixture  \n solution was incubated on ice for 1 h. Hydrogen fluoride was then evaporated\nunder an N2 stream to reduce  \n the volume to dryness. The remaining material was neutralized with 3ml\nTris\\u2013HCl (250mmol L-1, pH 8.0) and  \n followed by centrifugation at 11,000 g for 15 min with 3000 amu Microsep\ncentrifugal filter tubes (Milipore).  \n The filtrate was collected and defined as the fraction of digested silica\nwith <3000 amu frustule BF residues.  \n The supernatant (defined as>3000amu HF soluble BF, e.g., silaffin) was\nconcentrated to 250 \\u03bcL and rinsed with  \n milli-Q water. The pellet from this step was then washed by a 3 ml, 200mmol\nL-1 ammonium acetate solution  \n twice with centrifugation at 3000 g for 20 min. The pellet was then\nresuspended in a 2 ml, 100mmol L-1  \n ammonium acetate solution and was sonicated for 20 s until the mixture\nsolution appeared homogenized.  \n After ultracentrifuging the mixture solution at 12,000 g for 5 min, the\npellet (>3000 amu HF insoluble BF,  \n e.g., cingulin) was collected and freeze dried for later use. Combined BF\nfrom all three HF fractions represented  \n frustule-embedded biopolymers.\n \nActivity concentrations of 234Th, 233Pa, 210Pb, and 7Be were measured by\ncounting the gamma decay energies at 63.5 keV, 312 keV, 46.5 keV, and 477.6\nkeV, respectively, on a Canberra ultrahigh purity germanium well detector. The\n210Po activity was analyzed by liquid scintillation counting (Beckman Model\n8100 Liquid Scintillation Counter).  \n Concentrations of total carbohydrate (TCHO) were determined by the TPTZ (2,\n4, 6-tripyridyl-s-triazine) method using glucose as the standard and [Hung and\nSantschi, 2001]. Protein content was determined using a modified Lowry protein\nassay, using bovine serum albumin as the standard (Pierce, Thermo Scientific).\nuronic acids (URA) were measured by the metahydroxyphenyl method using\nglucuronic acid as the standard [Hung and Santschi, 2001].\n \nElemental contents of carbon (C) and nitrogen (N), were determined by a Perkin\nElmer CHN 2400 analyzer, using cysteine (29.99% C, 11.67% N) as a standard.
attribute NC_GLOBAL awards_0_award_nid String 735995
attribute NC_GLOBAL awards_0_award_number String OCE-1356453
attribute NC_GLOBAL awards_0_data_url String http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1356453 (external link)
attribute NC_GLOBAL awards_0_funder_name String NSF Division of Ocean Sciences
attribute NC_GLOBAL awards_0_funding_acronym String NSF OCE
attribute NC_GLOBAL awards_0_funding_source_nid String 355
attribute NC_GLOBAL awards_0_program_manager String Henrietta N Edmonds
attribute NC_GLOBAL awards_0_program_manager_nid String 51517
attribute NC_GLOBAL cdm_data_type String Other
attribute NC_GLOBAL comment String Percent activity of organic fractions from diatoms that bind with radionuclide \n  PI: Peter H. Santschi \n  Version: 2019-04-11
attribute NC_GLOBAL Conventions String COARDS, CF-1.6, ACDD-1.3
attribute NC_GLOBAL creator_email String info at bco-dmo.org
attribute NC_GLOBAL creator_name String BCO-DMO
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.bco-dmo.org/ (external link)
attribute NC_GLOBAL data_source String extract_data_as_tsv version 2.3  19 Dec 2019
attribute NC_GLOBAL date_created String 2019-04-11T19:14:56Z
attribute NC_GLOBAL date_modified String 2019-04-11T19:52:12Z
attribute NC_GLOBAL defaultDataQuery String &amp;time&lt;now
attribute NC_GLOBAL doi String 10.1575/1912/bco-dmo.764885.1
attribute NC_GLOBAL infoUrl String https://www.bco-dmo.org/dataset/764885 (external link)
attribute NC_GLOBAL institution String BCO-DMO
attribute NC_GLOBAL instruments_0_acronym String LSC
attribute NC_GLOBAL instruments_0_dataset_instrument_description String The 210Po activity was analyzed by liquid scintillation counting (Beckman Model 8100 Liquid Scintillation Counter).
attribute NC_GLOBAL instruments_0_dataset_instrument_nid String 764895
attribute NC_GLOBAL instruments_0_description String Liquid scintillation counting is an analytical technique which is defined by the incorporation of the radiolabeled analyte into uniform distribution with a liquid chemical medium capable of converting the kinetic energy of nuclear emissions into light energy. Although the liquid scintillation counter is a sophisticated laboratory counting system used the quantify the activity of particulate emitting (ß and a) radioactive samples, it can also detect the auger electrons emitted from 51Cr and 125I samples.
attribute NC_GLOBAL instruments_0_instrument_external_identifier String https://vocab.nerc.ac.uk/collection/L05/current/LAB21/ (external link)
attribute NC_GLOBAL instruments_0_instrument_name String Liquid Scintillation Counter
attribute NC_GLOBAL instruments_0_instrument_nid String 624
attribute NC_GLOBAL instruments_0_supplied_name String Beckman Model 8100 Liquid Scintillation Counter
attribute NC_GLOBAL instruments_1_acronym String CHN_EA
attribute NC_GLOBAL instruments_1_dataset_instrument_description String Elemental contents of carbon (C) and nitrogen (N), were determined by a Perkin Elmer CHN 2400 analyzer, using cysteine (29.99% C, 11.67% N) as a standard.
attribute NC_GLOBAL instruments_1_dataset_instrument_nid String 764893
attribute NC_GLOBAL instruments_1_description String A CHN Elemental Analyzer is used for the determination of carbon, hydrogen, and  nitrogen content in organic and other types of materials, including  solids, liquids, volatile, and viscous samples.
attribute NC_GLOBAL instruments_1_instrument_name String CHN Elemental Analyzer
attribute NC_GLOBAL instruments_1_instrument_nid String 625
attribute NC_GLOBAL instruments_1_supplied_name String Perkin Elmer CHN 2400 analyzer
attribute NC_GLOBAL instruments_2_dataset_instrument_description String Activity concentrations of 234Th, 233Pa, 210Pb, and 7Be were measured by counting the gamma decay energies at 63.5 keV, 312 keV, 46.5 keV, and 477.6 keV, respectively, on a Canberra ultrahigh purity germanium well detector.
attribute NC_GLOBAL instruments_2_dataset_instrument_nid String 764894
attribute NC_GLOBAL instruments_2_description String Instruments measuring the relative levels of electromagnetic radiation of different wavelengths in the gamma-ray waveband.
attribute NC_GLOBAL instruments_2_instrument_name String Gamma Ray Spectrometer
attribute NC_GLOBAL instruments_2_instrument_nid String 670659
attribute NC_GLOBAL instruments_2_supplied_name String Canberra ultrahigh purity germanium well detector
attribute NC_GLOBAL keywords String aeps, amu, bco, bco-dmo, biological, chemical, data, dataset, dmo, edta, erddap, frequency, HF, HF_insoluble, HF_soluble, high, insoluble, lt_3000_amu, management, naeps, oceanography, office, preliminary, radionuclide, sds, soluble
attribute NC_GLOBAL license String https://www.bco-dmo.org/dataset/764885/license (external link)
attribute NC_GLOBAL metadata_source String https://www.bco-dmo.org/api/dataset/764885 (external link)
attribute NC_GLOBAL param_mapping String {'764885': {}}
attribute NC_GLOBAL parameter_source String https://www.bco-dmo.org/mapserver/dataset/764885/parameters (external link)
attribute NC_GLOBAL people_0_affiliation String Texas A&M, Galveston
attribute NC_GLOBAL people_0_affiliation_acronym String TAMUG
attribute NC_GLOBAL people_0_person_name String Peter Santschi
attribute NC_GLOBAL people_0_person_nid String 735998
attribute NC_GLOBAL people_0_role String Principal Investigator
attribute NC_GLOBAL people_0_role_type String originator
attribute NC_GLOBAL people_1_affiliation String Texas A&M, Galveston
attribute NC_GLOBAL people_1_affiliation_acronym String TAMUG
attribute NC_GLOBAL people_1_person_name String Antonietta Quigg
attribute NC_GLOBAL people_1_person_nid String 736000
attribute NC_GLOBAL people_1_role String Co-Principal Investigator
attribute NC_GLOBAL people_1_role_type String originator
attribute NC_GLOBAL people_2_affiliation String Texas A&M, Galveston
attribute NC_GLOBAL people_2_affiliation_acronym String TAMUG
attribute NC_GLOBAL people_2_person_name String Kathleen Schwehr
attribute NC_GLOBAL people_2_person_nid String 736002
attribute NC_GLOBAL people_2_role String Co-Principal Investigator
attribute NC_GLOBAL people_2_role_type String originator
attribute NC_GLOBAL people_3_affiliation String Texas A&M, Galveston
attribute NC_GLOBAL people_3_affiliation_acronym String TAMUG
attribute NC_GLOBAL people_3_person_name String Chen Xu
attribute NC_GLOBAL people_3_person_nid String 736004
attribute NC_GLOBAL people_3_role String Co-Principal Investigator
attribute NC_GLOBAL people_3_role_type String originator
attribute NC_GLOBAL people_4_affiliation String Woods Hole Oceanographic Institution
attribute NC_GLOBAL people_4_affiliation_acronym String WHOI BCO-DMO
attribute NC_GLOBAL people_4_person_name String Mathew Biddle
attribute NC_GLOBAL people_4_person_nid String 708682
attribute NC_GLOBAL people_4_role String BCO-DMO Data Manager
attribute NC_GLOBAL people_4_role_type String related
attribute NC_GLOBAL project String Biopolymers for radionuclides
attribute NC_GLOBAL projects_0_acronym String Biopolymers for radionuclides
attribute NC_GLOBAL projects_0_description String NSF Award Abstract:\nParticle-associated natural radioisotopes are transported to the ocean floor mostly via silica and carbonate ballasted particles, allowing their use as tracers for particle transport. Th(IV), Pa (IV,V), Po(IV), Pb(II) and Be(II) radionuclides are important proxies in oceanographic investigations, used for tracing particle and colloid cycling, estimating export fluxes of particulate organic carbon, tracing air-sea exchange, paleoproductivity, and/or ocean circulation in paleoceanographic studies. Even though tracer approaches are considered routine, there are cases where data interpretation or validity has become controversial, largely due to uncertainties about inorganic proxies and organic carrier molecules. Recent studies showed that cleaned diatom frustules and pure silica particles, sorb natural radionuclides to a much lower extent (by 1-2 orders of magnitude) than whole diatom cells (with or without shells). Phytoplankton that build siliceous or calcareous shells, such as the diatoms and coccolithophores, are assembled via bio-mineralization processes using biopolymers as nanoscale templates. These templates could serve as possible carriers for radionuclides and stable metals.\nIn this project, a research team at the Texas A & M University at Galveston hypothesize that radionuclide sorption is controlled by selective biopolymers that are associated with biogenic opal (diatoms), CaCO3 (coccolithophores) and the attached exopolymeric substances (EPS), rather than to pure mineral phase. To pursue this idea, the major objectives of their research will include separation, identification and molecular-level characterization of the individual biopolymers (e.g., polysaccharides, uronic acids, proteins, hydroquinones, hydroxamate siderophores, etc.) that are responsible for binding different radionuclides (Th, Pa, Pb, Po and Be) attached to cells or in the matrix of biogenic opal or CaCO3 as well as attached EPS mixture, in laboratory grown diatom and coccolithophore cultures. Laboratory-scale radiolabeling experiments will be conducted, and different separation techniques and characterization techniques will be applied.\nIntellectual Merit : It is expected that this study will help elucidate the molecular basis of the templated growth of diatoms and coccoliths, EPS and their role in scavenging natural radionuclides in the ocean, and help resolve debates on the oceanographic tracer applications of different natural radioisotopes (230,234Th, 231Pa, 210Po, 210Pb and 7,10Be). The proposed interdisciplinary research project will require instrumental approaches for molecular-level characterization of these radionuclides associated carrier molecules.\nBroader Impacts: The results of this study will be relevant for understanding biologically mediated ocean scavenging of radionuclides by diatoms and coccoliths which is important for carbon cycling in the ocean, and will contribute to improved interpretation of data obtained by field studies especially through the GEOTRACES program. This new program will enhance training programs at TAMUG for postdocs, graduate and undergraduate students. Lastly, results will be integrated in college courses and out-reach activities at Texas A&M University, including NSF-REU, Sea Camp, Elder Hostel and exhibits at the local science fair and interaction with its after-school program engaging Grade 9-12 students from groups traditionally underrepresented.
attribute NC_GLOBAL projects_0_end_date String 2018-02
attribute NC_GLOBAL projects_0_name String Biopolymers as carrier phases for selected natural radionuclides (of Th, Pa, Pb, Po, Be) in diatoms and coccolithophores
attribute NC_GLOBAL projects_0_project_nid String 735996
attribute NC_GLOBAL projects_0_start_date String 2014-03
attribute NC_GLOBAL publisher_name String Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v55
attribute NC_GLOBAL summary String Percent amount of organic fractions from diatoms that bind with radionuclide. In order to investigate the importance of biogenic silica associated biopolymers on the scavenging of radionuclides, the diatom Phaeodactylum tricornutum was incubated together with the radionuclides 234Th, 233Pa, 210Pb, and 7Be during their growth phase. Normalized affinity coefficients were determined for the radionuclides bound with different organic compound classes (i.e., proteins, total carbohydrates, uronic acids) in extracellular (nonattached and attached exopolymeric substances), intracellular (ethylene diamine tetraacetic acid and sodium dodecyl sulfate extractable), and frustule embedded biopolymeric fractions (BF). Results indicated that radionuclides were mostly concentrated in frustule BF. Among three measured organic components, Uronic acids showed the strongest affinities to all tested radionuclides. Confirmed by spectrophotometry and two-dimensional heteronuclear single quantum coherence-nuclear magnetic resonance analyses, the frustule BF were mainly composed of carboxyl-rich, aliphatic-phosphoproteins, which were likely responsible for the strong binding of many of the radionuclides. Results from this study provide evidence for selective absorption of radionuclides with different kinds of diatom-associated biopolymers acting in concert rather than as a single compound. This clearly indicates the importance of these diatom-related biopolymers, especially frustule biopolymers, in the scavenging and fractionation of radionuclides used as particle tracers in the ocean.
attribute NC_GLOBAL title String Percent activity of organic fractions from diatoms that bind with radionuclide
attribute NC_GLOBAL version String 1
attribute NC_GLOBAL xml_source String osprey2erddap.update_xml() v1.3
variable radionuclide String
attribute radionuclide bcodmo_name String unknown
attribute radionuclide description String radionuclide
attribute radionuclide long_name String Radionuclide
attribute radionuclide units String unitless
variable NAEPS float
attribute NAEPS _FillValue float NaN
attribute NAEPS actual_range float 3.13, 36.8
attribute NAEPS bcodmo_name String unknown
attribute NAEPS description String non-attached exopolymeric substance
attribute NAEPS long_name String NAEPS
attribute NAEPS units String unitless (percent)
variable AEPS float
attribute AEPS _FillValue float NaN
attribute AEPS actual_range float 5.06, 18.04
attribute AEPS bcodmo_name String unknown
attribute AEPS description String attached exopolymeric substance
attribute AEPS long_name String AEPS
attribute AEPS units String unitless (percent)
variable HF_soluble float
attribute HF_soluble _FillValue float NaN
attribute HF_soluble actual_range float 0.43, 8.69
attribute HF_soluble bcodmo_name String unknown
attribute HF_soluble description String hydrofluoric acid
attribute HF_soluble long_name String HF Soluble
attribute HF_soluble units String unitless (percent)
variable HF_insoluble float
attribute HF_insoluble _FillValue float NaN
attribute HF_insoluble actual_range float 6.53, 23.9
attribute HF_insoluble bcodmo_name String unknown
attribute HF_insoluble description String hydrofluoric acid insoluble
attribute HF_insoluble long_name String HF Insoluble
attribute HF_insoluble units String unitless (percent)
variable lt_3000_amu float
attribute lt_3000_amu _FillValue float NaN
attribute lt_3000_amu actual_range float 1.35, 19.48
attribute lt_3000_amu bcodmo_name String unknown
attribute lt_3000_amu description String less than 3000 atomic mass units
attribute lt_3000_amu long_name String Lt 3000 Amu
attribute lt_3000_amu units String unitless (percent)
variable EDTA float
attribute EDTA _FillValue float NaN
attribute EDTA actual_range float 21.78, 37.39
attribute EDTA bcodmo_name String unknown
attribute EDTA description String ethylene diamine tetraacetic acid
attribute EDTA long_name String EDTA
attribute EDTA units String unitless (percent)
variable SDS float
attribute SDS _FillValue float NaN
attribute SDS actual_range float 2.54, 25.15
attribute SDS bcodmo_name String unknown
attribute SDS description String sodium dodecyl sulfate
attribute SDS long_name String SDS
attribute SDS units String unitless (percent)

 
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