WorldWideScience

Sample records for delta 14c values

  1. Rarotonga Radiocarbon (delta 14C) for 1950 to 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rarotonga coral radiocarbon (14C) timeseries. Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per mil as documented by an...

  2. Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Urvina Bay coral radiocarbon (14C) timeseries. (90 deg W, 0.5 deg S) Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per...

  3. Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

  4. Seasonally Resolved Surface Water (delta)14C Variability in the Lombok Strait: A Coralline Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T P; Fallon, S J; Moore, M D; Schrag, D P; Charles, C D

    2008-04-23

    We have explored surface water mixing in the Lombok Strait through a {approx}bimonthly resolved surface water {Delta}{sup 14}C time-series reconstructed from a coral in the Lombok Strait that spans 1937 through 1990. The prebomb surface water {Delta}{sup 14}C average is -60.5{per_thousand} and individual samples range from -72{per_thousand} to 134{per_thousand}. The annual average post-bomb maximum occurs in 1973 and is 122{per_thousand}. The timing of the post-bomb maximum is consistent with a primary subtropical source for the surface waters in the Indonesian Seas. During the post-bomb period the coral records regular seasonal cycles of 5-20{per_thousand}. Seasonal high {Delta}{sup 14}C occur during March-May (warm, low salinity), and low {Delta}{sup 14}C occur in September (cool, higher salinity). The {Delta}{sup 14}C seasonality is coherent and in phase with the seasonal {Delta}{sup 14}C cycle observed in Makassar Strait. We estimate the influence of high {Delta}{sup 14}C Makassar Strait (North Pacific) water flowing through the Lombok Strait using a two endmember mixing model and the seasonal extremes observed at the two sites. The percentage of Makassar Strait water varies between 16 and 70%, and between 1955 and 1990 it averages 40%. During La Nina events there is a higher percentage of Makassar Strait (high {Delta}{sup 14}C) water in the Lombok Strait.

  5. Investigations of (Delta)14C, (delta)13C, and (delta)15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L A; Andrews, A H; Cailliet, G M; Brown, T A; Coale, K H

    2006-06-08

    The white shark (Carcharodon carcharias) has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon ({sup 14}C) age validation uses the discrete {sup 14}C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for {Delta}{sup 14}C and stable carbon and nitrogen isotopes ({delta}{sup 13}C and {delta}{sup 15}N). The aim of this study was to evaluate the utility of {sup 14}C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the {sup 14}C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep {sup 14}C gradients with depth in the eastern North Pacific Ocean.

  6. Human urinary excretion profile after smoking and oral administration of ( sup 14 C)delta 1-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E.; Gillespie, H.K.; Halldin, M.M. (BMC, Uppsala (Sweden))

    1990-05-01

    The urinary excretion profiles of delta 1-tetrahydrocannabinol (delta 1-THC) metabolites have been evaluated in two chronic and two naive marijuana users after smoking and oral administration of ({sup 14}C)delta 1-THC. Urine was collected for five days after each administration route and analyzed for total delta 1-THC metabolites by radioactivity determination, for delta 1-THC-7-oic acid by high-performance liquid chromatography, and for cross-reacting cannabinoids by the EMIT d.a.u. cannabinoid assay. The average urinary excretion half-life of {sup 14}C-labeled delta 1-THC metabolites was calculated to be 18.2 +/- 4.9 h (+/- SD). The excretion profiles of delta 1-THC-7-oic acid and EMIT readings were similar to the excretion profile of {sup 14}C-labeled metabolites in the naive users. However, in the chronic users the excretion profiles of delta 1-THC-7-oic acid and EMIT readings did not resemble the radioactive excretion due to the heavy influence from previous Cannabis use. Between 8-14% of the radioactive dose was recovered in the urine in both user groups after oral administration. Lower urinary recovery was obtained both in the chronic and naive users after smoking--5 and 2%, respectively.

  7. Delta sup(14)C, sigma CO sub(2) salinity of the western Indian Ocean deep waters: Spatial and temporal variations

    Digital Repository Service at National Institute of Oceanography (India)

    Somayajulu, B.L.K.; Bhushan, R.; Narvekar, P.V.

    ppt, as revealed by the GEOSECS data (1977-78). The delta sup(14)C-sigma CO sub(2)-salinity relationships show better correlation in the western sector. High biological productivity induced changes and corrosive deepwaters could account for sigma CO...

  8. Solar modulation of cosmic ray intensity and solar flare events inferred from (14)C contents in dated tree rings

    Science.gov (United States)

    Fan, C. Y.; Chen, T. M.; Yun, S. X.; Dai, K. M.

    1985-01-01

    The delta 14C values in 42 rings of a white spruce grown in Mackenzie Delta was measured as a continuing effort of tracing the history of solar modulation of cosmic ray intensity. The delta 14C values in six rings were measured, in search of a 14C increase due to two large solar flares that occurred in 1942. The results are presented.

  9. Surface water processes in the Indonesian Throughflow as documented by a high-resolution coral (Delta)14C record

    Energy Technology Data Exchange (ETDEWEB)

    Fallon, S J; Guilderson, T P

    2008-04-23

    To explore the seasonal to decadal variability in surface water masses that contribute to the Indonesian Throughflow we have generated a 115-year bi-monthly coral-based radiocarbon time-series from a coral in the Makassar Straits. In the pre-bomb (pre-1955) era from 1890 to 1954, the radiocarbon time series occasionally displays a small seasonal signal (10-15{per_thousand}). After 1954 the radiocarbon record increases rapidly, in response to the increased atmospheric {sup 14}C content caused by nuclear weapons testing. From 1957 to 1986 the record displays clear seasonal variability from 15 to 60{per_thousand} and the post-bomb peak (163 per mil) occurred in 1974. The seasonal cycle of radiocarbon can be attributed to variations of surface waters passing through South Makassar Strait. Southern Makassar is under the influence of the Northwest Monsoon, which is responsible for the high Austral summer radiocarbon (North Pacific waters) and the Southeast Monsoon that flushes back a mixture of low (South Pacific and upwelling altered) radiocarbon water from the Banda Sea. The coral record also shows a significant {sup 14}C peak in 1955 due to bomb {sup 14}C water advected into this region in the form of CaCO{sub 3} particles (this implies that the particles were advected intact and then become entrapped in the coral skeleton--is this what we really mean? Wouldn't even fine particles settle out over the inferred transit time from Bikini to MAK?) or water particles with dissolved labeled CO{sub 2} produced during fallout from the Castle tests in 1954.

  10. Creating a multi-gas proxy for Delta 14C and atmospheric fossil fuel-CO2. Kevin Coakley, John Miller , Scott Lehman, Stephen Montzka, Colm Sweeney, Arlyn Andrews , Ben Miller

    Science.gov (United States)

    Coakley, K. J.; Miller, J. B.; Lehman, S.; Montzka, S. A.; Andrews, A. E.; Miller, B. R.

    2013-12-01

    The C14:C12 ratio of atmospheric CO2 (expressed as Delta 14C) is the gold standard measurement to derive the portion of observed atmospheric CO2 gradients resulting from combustion of fossil fuels (CO2-ff). This is because fossil fuels are devoid of 14C, unlike all other sources and sinks that impact atmospheric Delta14C. With enough 14C measurements, independent, 'top-down', estimation of US fossil fuel-CO2 emissions should be possible. However, our ability to make carbon-14 measurements is severely constrained by cost, accessibility to accelerator mass spectrometers (AMS) and the volume of air required to make high precision (~0.2 %) measurements of 14CO2 (mixing ratio is ~ 4e-16 mol/mol). Thus, Delta 14C is currently measured in only a small subset of NOAA/ESRL Global Monitoring Division (GMD) tall-tower and aircraft air samples. Here, we present a Projection Pursuit Regression (PPR) model to predict CO2-ff measured at different times and altitudes in terms of surrogate gases that are more widespread and relatively inexpensive to measure. This method would, in effect, allow expansion of Delta 14C measurements by factor of ~3 or 4 throughout North America. To create a proxy for CO2-ff, we take advantage of the observed correlations between (Delta 14C-derrived) CO2-ff and regional-scale enhancements of a wide array of anthropogenic gases, like CO, SF6, and halo- and hydro-carbons. We select the complexity and form of the PPR model by cross validation where validation data prediction error is minimized. In cross validation, the prediction model is based on the training data and not the validation data. We quantify prediction model performance with test data excluded from the model development process. According to cross validation, the PPR model is superior to a simpler linear model. Comparison with test CO2-ff data shows that CO2-ff can be predicted with a root mean square error of 1.1 ppm, only slightly higher than the Delta 14C-precision limit for CO2-ff of 1

  11. Distributions of fossil fuel originated CO{sub 2} in five metropolitan areas of Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju) according to the {Delta}{sup 14}C in ginkgo leaves

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H.; Hong, W. [Korea Institute of Geoscience and Mineral Resources, 124 Gwahang-no Yuseong, Daejeon 305-350 (Korea, Republic of); Park, G., E-mail: junghun@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources, 124 Gwahang-no Yuseong, Daejeon 305-350 (Korea, Republic of); Sung, K.S.; Lee, K.H.; Kim, Y.E.; Kim, J.K.; Choi, H.W.; Kim, G.D.; Woo, H.J. [Korea Institute of Geoscience and Mineral Resources, 124 Gwahang-no Yuseong, Daejeon 305-350 (Korea, Republic of)

    2013-01-15

    We collected a batch of ginkgo (Ginkgo biloba Linnaeus) leaf samples at five metropolitan areas of Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju) in 2009 to obtain the regional distribution of fossil fuel originated CO{sub 2} (fossil fuel CO{sub 2}) in the atmosphere. Regions assumed to be free of fossil fuel CO{sub 2} were also selected, namely Mt. Chiak, Mt. Kyeryong, Mt. Jiri, Anmyeon Island, and Jeju Island and ginkgo leaf samples were collected in those areas during the same period. The {Delta}{sup 14}C values of the samples were measured using Accelerator Mass Spectrometry (AMS) and the fossil fuel CO{sub 2} ratios in the atmosphere were obtained in the five metropolitan areas. The average ratio of fossil fuel CO{sub 2} in Seoul was higher than that in the other four cities. The leaves from the Sajik Tunnel in Seoul recorded the highest FFCTC (fossil fuel CO{sub 2} over total CO{sub 2} in atmosphere), 13.9 {+-} 0.5%, as the air flow of the surrounding neighborhood of the Sajik Tunnel was blocked.

  12. Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

    Science.gov (United States)

    Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

    2010-03-24

    To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

  13. A critical review of atmospheric 14 C activities

    Energy Technology Data Exchange (ETDEWEB)

    Krajcar Bronic, I.; Horvatincic, N.; Baresic, J.; Obelic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Vreca, P. [Jozef Stefan Institute, Ljubljana, (Slovenia)

    2006-07-01

    14 C activity of atmospheric CO{sub 2} has been measured at the Rudjer Boskovi Institute as a part of environmental monitoring in order to determine possible differences between clean-air sites, industrialized city and sites in the vicinity of nuclear power plant. Samples of Cfrom the atmosphere have been collected by absorption of CO{sub 2} on the saturated carbonate-free NaOH solution for a period of 1 month under stationary conditions. The obtained Na{sub 2} CO{sub 3} has been dissolved in HCl and the produced CO{sub 2} used for CH{sub 4} preparation by catalytic reaction with H{sub 2} at 450 degrees Celsius. A gas proportional counter filled with CH{sub 4} has been used for 14 C activity measurement. The method of collection of CO{sub 2} does not require any power source and can be therefore used for sampling at the remote sites, such as mountains or forests. However,due to the lack of mixing of the Na OH solution, the absorption process is limited on the surface of the solution, and there exists the possibility of fractionation of carbon isotopes due to different reaction rate constants of 12 C and 13 C. A continuous record of atmospheric 14 CO{sub 2} activity exists for the city of Zagreb (1986 to 2005), while shorter records (1-2 years) exist for several other sites of various characteristics: two clean-air sites (Mt. Medvednica, altitude about 1000 m a.s.l., for period 1995 to 1996, and the Plitvice National Park for period 2003 to 2005), and a site close to the Nuclear Power Plant Krsko (1984 to 1986).Within the bilateral Croatian-Slovene project we have recently measured also the stable isotope composition ({delta}13 C) of Na{sub 2}CO{sub 3} collected at two different sampling sites in order to determine seasonal fluctuations in both 14 C and 13 C isotope composition. Unexpectedly low {delta}13 C values have been obtained about (-25{+-}2)0/00 instead of expected (-7{+-}1)0/00. Such low values have been attributed to the carbon isotope fractionation during

  14. Atmospheric 14 C CO 2 variations in Japan during 1982--1999 based on 14 C measurements of rice grains.

    Science.gov (United States)

    Shibata, Setsuko; Kawano, Eiko; Nakabayashi, Takeshige

    2005-08-01

    (14)C in rice grains is a useful tracer of atmospheric (14)C(CO(2)). (14)C measurement in rice grains for 17 years during 1982--1999 reveals the following. There is negative correlation between Delta(14)C and the population densities of localities in Japan. Under-populated areas in the northern area of Japan and Okinawa remained clean in the 1990s. The (14)C(CO(2)) decline rates at those areas are near to that of Shauinsland. A latitudinal effect due to Chinese nuclear tests is observed in 1982. Small Seuss effects is observed at the middle latitudes in East Asia after 1995.

  15. Determination of microbial carbon sources and cycling during remediation of petroleum hydrocarbon impacted soil using natural abundance (14)C analysis of PLFA.

    Science.gov (United States)

    Cowie, Benjamin R; Greenberg, Bruce M; Slater, Gregory F

    2010-04-01

    In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study

  16. Individual protein balance strongly influences delta15N and delta13C values in Nile tilapia, Oreochromis niloticus.

    Science.gov (United States)

    Gaye-Siessegger, Julia; Focken, Ulfert; Abel, Hansjörg; Becker, Klaus

    2004-02-01

    Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing delta(15)N and delta(13)C values. An experiment using Nile tilapia [ Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on delta(15)N and delta(13)C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. delta(15)N and delta(13)C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5 per thousand to 4 per thousand and for C in the lipid-free body from 4 per thousand to 2.5 per thousand. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results.

  17. Analysis of historical delta values for IAEA/LANL NDA training courses

    Energy Technology Data Exchange (ETDEWEB)

    Geist, William [Los Alamos National Laboratory; Santi, Peter [Los Alamos National Laboratory; Swinhoe, Martyn [Los Alamos National Laboratory; Bonner, Elisa [FORMER N-4 STUDENT

    2009-01-01

    The Los Alamos National Laboratory (LANL) supports the International Atomic Energy Agency (IAEA) by providing training for IAEA inspectors in neutron and gamma-ray Nondestructive Assay (NDA) of nuclear material. Since 1980, all new IAEA inspectors attend this two week course at LANL gaining hands-on experience in the application of NDA techniques, procedures and analysis to measure plutonium and uranium nuclear material standards with well known pedigrees. As part of the course the inspectors conduct an inventory verification exercise. This exercise provides inspectors the opportunity to test their abilities in performing verification measurements using the various NDA techniques. For an inspector, the verification of an item is nominally based on whether the measured assay value agrees with the declared value to within three times the historical delta value. The historical delta value represents the average difference between measured and declared values from previous measurements taken on similar material with the same measurement technology. If the measurement falls outside a limit of three times the historical delta value, the declaration is not verified. This paper uses measurement data from five years of IAEA courses to calculate a historical delta for five non-destructive assay methods: Gamma-ray Enrichment, Gamma-ray Plutonium Isotopics, Passive Neutron Coincidence Counting, Active Neutron Coincidence Counting and the Neutron Coincidence Collar. These historical deltas provide information as to the precision and accuracy of these measurement techniques under realistic conditions.

  18. High and low value fish chains in the Mekong Delta: challenges for livelihoods and governance

    NARCIS (Netherlands)

    Vo Thi Thanh Loc,; Bush, S.R.; Xuan Sinh, Le; Nguyen Tri Khiem,

    2010-01-01

    This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function of value chains, their contributi

  19. The fate of river organic carbon in coastal areas: A study in the Rhône River delta using multiple isotopic (δ13C, Δ14C) and organic tracers

    Science.gov (United States)

    Cathalot, C.; Rabouille, C.; Tisnérat-Laborde, N.; Toussaint, F.; Kerhervé, P.; Buscail, R.; Loftis, K.; Sun, M.-Y.; Tronczynski, J.; Azoury, S.; Lansard, B.; Treignier, C.; Pastor, L.; Tesi, T.

    2013-10-01

    A significant fraction of the global carbon flux to the ocean occurs in River-dominated Ocean Margins (RiOMar) although large uncertainties remain in the cycle of organic matter (OM) in these systems. In particular, the OM sources and residence time have not been well clarified. Surface (0-1 cm) and sub-surface (3-4 cm) sediments and water column particles (bottom and intermediate depth) from the Rhône River delta system were collected in June 2005 and in April 2007 for a multi-proxy study. Lignin phenols, black carbon (BC), proto-kerogen/BC mixture, polycyclic aromatic hydrocarbons (PAHs), carbon stable isotope (δ13COC), and radiocarbon measurements (Δ14COC) were carried out to characterize the source of sedimentary organic material and to address degradation and transport processes. The bulk OM in the prodelta sediment appears to have a predominantly modern terrigenous origin with a significant contribution of modern vascular C3 plant detritus (Δ14COC = 27.9‰, δ13COC = -27.4‰). In contrast, the adjacent continental shelf, below the river plume, seems to be dominated by aged OM (Δ14COC = -400‰, δ13COC = -24.2‰), and shows no evidence of dilution and/or replacement by freshly produced marine carbon. Our data suggest an important contribution of black carbon (50% of OC) in the continental shelf sediments. Selective degradation processes occur along the main dispersal sediment system, promoting the loss of a modern terrestrial OM but also proto-kerogen-like OM. In addition, we hypothesize that during the transport across the shelf, a long term resuspension/deposition loop induces efficient long term degradation processes able to rework such refractory-like material until the OC is protected by the mineral matrix of particles.

  20. Reconstructing Ocean Circulation using Coral (triangle)14C Time Series

    Energy Technology Data Exchange (ETDEWEB)

    Kashgarian, M; Guilderson, T P

    2001-02-23

    We utilize monthly {sup 14}C data derived from coral archives in conjunction with ocean circulation models to address two questions: (1) how does the shallow circulation of the tropical Pacific vary on seasonal to decadal time scales and (2) which dynamic processes determine the mean vertical structure of the equatorial Pacific thermocline. Our results directly impact the understanding of global climate events such as the El Nino-Southern Oscillation (ENSO). To study changes in ocean circulation and water mass distribution involved in the genesis and evolution of ENSO and decadal climate variability, it is necessary to have records of climate variables several decades in length. Continuous instrumental records are limited because technology for continuous monitoring of ocean currents (e.g. satellites and moored arrays) has only recently been available, and ships of opportunity archives such as COADS contain large spatial and temporal biases. In addition, temperature and salinity in surface waters are not conservative and thus can not be independently relied upon to trace water masses, reducing the utility of historical observations. Radiocarbon in sea water is a quasi-conservative water mass tracer and is incorporated into coral skeletal material, thus coral {sup 14}C records can be used to reconstruct changes in shallow circulation that would be difficult to characterize using instrumental data. High resolution {Delta}{sup 14}C timeseries such as ours, provide a powerful constraint on the rate of surface ocean mixing and hold great promise to augment one time oceanographic surveys. {Delta}{sup 14}C timeseries such as these, not only provide fundamental information about the shallow circulation of the Pacific, but can also be directly used as a benchmark for the next generation of high resolution ocean models used in prognosticating climate. The measurement of {Delta}{sup 14}C in biological archives such as tree rings and coral growth bands is a direct record of

  1. Measurement of {sup 14}C/{sup 12}C ratios in plant samples that were affected by the Fukushima nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Risa; Inoue, Aki; Muramatsu, Yasuyuki [Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 (Japan); Matsuzaki, Hiroyuki [The University of Tokyo, Micro Analysis Laboratory, Tandem Accelerator, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan)

    2014-07-01

    In nature, {sup 14}C is produced by cosmic ray reactions in the upper atmosphere, and its production is influenced by the flux of cosmic rays. This nuclide is also released into the atmosphere by anthropogenic sources such as nuclear weapons testing and a nuclear accident. The produced {sup 14}C immediately becomes {sup 14}CO{sub 2} and it is absorbed by plants through photosynthesis. Therefore, plants are reflected by atmospheric {sup 14}C levels at that time. Although there are many papers reporting the release of several nuclides by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident occurred in March, 2011, it is not clear whether appreciable amounts of {sup 14}C were released into the environment due to the accident. In this study, we focus on {sup 14}C levels in plant samples collected from several locations in Fukushima Prefecture (Okuma, Namie, Iitate, and Fukushima-city) and examine the possible influence on the {sup 14}C revels in plants. Since cedars and pines are evergreen, the leaves should have been contaminated at the time of the accident. We analyzed old leaves, which were grown before the accident, and new leaves, which were grown after the accident. Both old and new leaves were collected in the same branch. In order to compare delta {sup 14}C values in leaves collected from Fukushima Prefecture with background values, we have used plant samples collected from remote areas such as Chiba and Niigata Prefectures. The samples were dried, pulverized in a blender and homogenized. Then samples were placed between copper oxide wires in a quarts tube, burned and oxidized. The produced CO{sub 2} mixed gases were purified in a vacuum line. To prepare a graphite target for AMS, the purified CO{sub 2} was reduced. {sup 14}C/{sup 12}C ratio in the graphite was measured by AMS at the University of Tokyo or Japan Atomic Energy Agency. Analytical results showed that delta {sup 14}C values in plant samples collected from the highly contaminated areas such as

  2. Carbon isotope ratio (delta13C) values of urinary steroids for doping control in sport.

    Science.gov (United States)

    Cawley, Adam T; Trout, Graham J; Kazlauskas, Rymantas; Howe, Christopher J; George, Adrian V

    2009-03-01

    The detection of steroids originating from synthetic precursors in relation to their chemically identical natural analogues has proven to be a significant challenge for doping control laboratories accredited by the World Anti-Doping Agency (WADA). Endogenous steroid abuse may be confirmed by utilising the atomic specificity of gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) that enables the precise measurement of differences in stable isotope ratios that arise as a result of fractionation patterns inherent in the source of steroids. A comprehensive carbon isotope ratio (delta(13)C) profiling study (n=1262) of urinary ketosteroids is reported that demonstrates the inter-individual variation that can be expected from factors such as diet, ethnicity, gender and age within and between different populations (13 countries). This delta(13)C distribution is shown by principal component analysis (PCA) to provide a statistical comparison to delta(13)C values observed following administration of testosterone enanthate. A limited collection of steroid diol data (n=100; consisting of three countries) is also presented with comparison to delta(13)C values of excreted testosterone to validate criteria for WADA accredited laboratories to prove doping offences.

  3. 14C Analysis of protein extracts from Bacillus spores.

    Science.gov (United States)

    Cappuccio, Jenny A; Falso, Miranda J Sarachine; Kashgarian, Michaele; Buchholz, Bruce A

    2014-07-01

    Investigators of bioagent incidents or interdicted materials need validated, independent analytical methods that will allow them to distinguish between recently made bioagent samples versus material drawn from the archives of a historical program. Heterotrophic bacteria convert the carbon in their food sources, growth substrate or culture media, into the biomolecules they need. The F(14)C (fraction modern radiocarbon) of a variety of media, Bacillus spores, and separated proteins from Bacillus spores was measured by accelerator mass spectrometry (AMS). AMS precisely measures F(14)C values of biological materials and has been used to date the synthesis of biomaterials over the bomb pulse era (1955 to present). The F(14)C of Bacillus spores reflects the radiocarbon content of the media in which they were grown. In a survey of commercial media we found that the F(14)C value indicated that carbon sources for the media were alive within about a year of the date of manufacture and generally of terrestrial origin. Hence, bacteria and their products can be dated using their (14)C signature. Bacillus spore samples were generated onsite with defined media and carbon free purification and also obtained from archived material. Using mechanical lysis and a variety of washes with carbon free acids and bases, contaminant carbon was removed from soluble proteins to enable accurate (14)C bomb-pulse dating. Since media is contemporary, (14)C bomb-pulse dating of isolated soluble proteins can be used to distinguish between historical archives of bioagents and those produced from recent media.

  4. Organosolv extraction of lignin from hydrolyzed almond shells and application of the delta-value theory.

    Science.gov (United States)

    Quesada-Medina, Joaquín; López-Cremades, Francisco Javier; Olivares-Carrillo, Pilar

    2010-11-01

    The solubility of lignin from hydrolyzed almond (Prunus amygdalus) shells in different acetone, ethanol and dioxane-water mixtures and conditions (extraction time and temperature) was studied. The concept of the solubility parameter (delta-value) was applied to explain the effect of organic solvent concentration on lignin solubility. The organic solvent-water mixture that led to the highest lignin extraction was composed of a 75% vol. of organic solvent for all the solvent series investigated (acetone, ethanol and dioxane). Moreover, the best lignin extraction conditions were a temperature of 210 degrees C and an extraction time of 40 min for the acetone and ethanol series, and 25 min for the dioxane series. The delta-value of the hydrolyzed almond shell lignin [14.60 (cal/cm(3))(1/2)] and that of the organic solvent-water mixtures was calculated. The experimental delignification capacity of the aqueous organic solvents clearly reflected the proximity of their delta-value to that of lignin. The hydrogen-bonding capacity of the solvent-water mixtures was also taken into account. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Intraspecific variation in hair delta(13)C and delta(15)N values of ring-tailed lemurs (Lemur catta) with known individual histories, behavior, and feeding ecology.

    Science.gov (United States)

    Loudon, James E; Sponheimer, Matt; Sauther, Michelle L; Cuozzo, Frank P

    2007-07-01

    Stable carbon and nitrogen isotope compositions were analyzed from hair samples of 30 sympatric ring-tailed lemurs (Lemur catta) inhabiting the Beza Mahafaly Special Reserve, Madagascar. All lemurs were known individuals involved in a longitudinal study, which allowed us to explore the degree to which group membership, sex, health status, and migration influenced their stable isotope compositions. The differences in delta(13)C and delta(15)N values between groups were small (lemur conservation. There were few sex differences, but significant differences did occur between individuals of normal and suboptimal health, with those in poor health (especially those in the worst condition) being enriched in (15)N and to a lesser degree (13)C compared with healthy individuals. Moreover, lemurs that had emigrated between 2003 and 2004 had different delta(13)C and delta(15)N compositions than their original groups. (c) 2007 Wiley-Liss, Inc.

  6. A study of the carbon dynamics of Japanese grassland and forest using {sup 14}C and {sup 13}C

    Energy Technology Data Exchange (ETDEWEB)

    Katsuno, Kazumi, E-mail: katsuno@nenv.k.u-tokyo.ac.j [University of Tokyo, Department of Natural Environmental Studies, Graduate School of Frontier Sciences, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8561 (Japan); Miyairi, Yosuke [University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Tamura, Kenji [University of Tsukuba, Graduate School of Life and Environmental Sciences, 1-1-1 Tennnodai, Tsukuba-shi, Ibaraki 305-8577 (Japan); Matsuzaki, Hiroyuki [University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Fukuda, Kenji [University of Tokyo, Department of Natural Environmental Studies, Graduate School of Frontier Sciences, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8561 (Japan)

    2010-04-15

    We quantified the carbon contents of grassland and forest soil using conventional methods and studied the changes in their dynamics by measuring delta{sup 13}C and DELTA{sup 14}C. Soil samples were taken from a neighboring Miscanthus sinensis grassland and Pinus densiflora forest in central Japan. Both had been maintained as grassland until the 1960s, when the latter was abandoned and became a pine forest by natural succession. The soil carbon content of the forest was much lower than that of the grassland, implying that the soil carbon decreased as the grassland became forest. The delta{sup 13}C values were very similar in the grassland and forest, at approximately -20 per mille , suggesting that M. sinensis (a C4 plant) contributed to carbon storage, whereas there was little carbon accumulation from P. densiflora (a C3 plant) in forest soil. The DELTA{sup 14}C values and calculated soil carbon mean residence time (MRT) showed that the soil carbon in the upper A horizon was older, and that in the lower A horizon was younger in forest than in grassland. From these results, we conclude that young, fast-MRT soil carbon is decomposed in the upper A horizon, and old, stable soil carbon was decomposed in the lower A horizon after the pine invasion.

  7. [sup 14]C concentrations in tree stems, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kikata, Yoji; Yonenobu, Hitoshi; Morishita, Fumio (Nagoya Univ. (Japan). Faculty of Agriculture); Hattori, Yoshiaki; Marsoen, S.N.

    1993-03-01

    The [sup 14]C concentrations in trees sampled at various latitudes were measured with a Tandetron Accelerator Mass Spectrometer at Nagoya University. The growing periods of the parts for [sup 14]C measurements were estimated by the relationship between meteorological conditions and the appearance of anatomical features of annual rings such as false rings, latewood formation, and so on. The following results were obtained: 1. The latitude dependence of the [sup 14]C variation is found in tree stems as well as in the atmosphere. 2. The [sup 14]C concentrations in tree stems are almost equal to those in the atmosphere at the latitude where the tree had grown and at the time when the sampled section is formed. Therefore the [sup 14]C concentrations in the atmosphere are estimated by those of the tree stems. 3. The time when the [sup 14]C concentration in the tree showed its maximum value has difference of 1 - 2 years with that of the latitude where the tree had grown. 4. This phenomena seemed to be related closely with the mechanism of global mixing of [sup 14]CO[sub 2] produced by atmospheric nuclear weapon tests. This mechanism causes a time lag of [sup 14]C variation between northern and southern hemisphere. (author).

  8. CCQM-K140: carbon stable isotope ratio delta values in honey

    Science.gov (United States)

    Dunn, P. J. H.; Goenaga-Infante, H.; Goren, A. C.; Şimşek, A.; Bilsel, M.; Ogrinc, N.; Armishaw, P.; Hai, L.

    2017-01-01

    As there can be small but measureable differences in isotope ratios between different sources of the same element/compound/material, isotope ratio measurements are applied in a number of different fields including archaeology, environmental science, geochemistry, forensic science and ecology. Isotope ratios for the light elements (H, C, N, O and S) are typically reported as δ-values which are isotope ratios expressed relative to an internationally agreed standard (this standard is the zero-point on the scale), although absolute isotope ratios which are traceable to the SI have also been reported. The IAWG has been granted a traceability exception for the use of arbitrary delta scales until SI traceability can be established at the required level of uncertainty but this goal is some years away. While the CCQM IAWG has previously organised several pilot studies on isotope ratio determination (CCQM-P75: Stable isotope delta values in methionine, 2006; CCQM-P105: Sr isotope ratios in wine, 2008; CCQM-K98: Pb isotope ratios in bronze with additional delta values in CCQM-P134, 2011), it has been a number of years since delta values of light elements have been considered and there has been no key comparison (KC). Therefore, the IAWG has included the need for a KC (CCQM-K140) based on an arbitrary delta scale in its program to support ongoing requirements to demonstrate core capabilities as well as specific claims of measurement capability (CMCs) in this area. The performance of all five of the CCQM-K140 participants was very good, illustrating their ability to obtain accurate results for carbon isotope ratios, within the calibration range afforded by internationally agreed reference materials (δ13CVPDB-LSVEC between ‑47.32 % and +535.3 %) with measurement uncertainties of between 0.08 and 0.28 %. This was despite the fact that no two participants used exactly the same approach in terms of instrumentation or data treatment. Main text To reach the main text of this

  9. Ecosystem Service Value for the Common Reed Wetlands in the Liaohe Delta, Northeast China

    DEFF Research Database (Denmark)

    Ye, Siyuan; Laws, Edward A.; Costanza, Robert;

    2016-01-01

    and societal developments. Although the direct and indirect services provided by such wetlands make valuable contributions to human welfare, wetlands are often given little weight in policy decisions, because ecosystem services are not fully “captured” in commercial markets or adequately quantified in terms...... comparable with the values of economic services and manufactured capital. In this study the value of 10 of 17 ecosystem services provided by the reed wetlands in the Liaohe Delta was estimated by using market pricing, shadow projects, and benefit transfer methods. The value of the 10 services provided...... by the 800 km2 of reed wetland totaled approximately US $2.68 billion. Remarkably, aquaculture and the production of pulp from reeds accounted for only 19% of the total value of the reed wetland services. About 32% of the value of the ecosystem services was attributed to non-consumptive recreation, an easily...

  10. Kinetics of metabolism of organic and inorganic 14C compounds.

    Science.gov (United States)

    Vasilenko IYa; Bugryshev, P F; Istomina, A G; Turova, V I

    1982-01-01

    Results of experimental studies on the dynamics of metabolism of various inorganic (NA2CO3, K2CO3, CaCO3) and organic (glucose, glycine, palmitic and succinic acids, ethanol and methanol) compounds of 14C after its single and long-term administration into the organism of rats are presented. The values of the corresponding rates of accumulation of 14C and the onset of the state of equilibrium after long-term administration of the radionuclide were elucidated for a number of compounds. Results of the studies can find practical application in norm-setting. The corresponding rate of accumulation in man of 14C taken in the diet was determined by extrapolation of the experimental data. It was found to be approximately 30. The state of practical 14C equilibrium in man occurs approximately 11/2 years after the beginning of the intake.

  11. Synthesis of [17-{sup 14}C] nicergoline

    Energy Technology Data Exchange (ETDEWEB)

    Angiuli, P.; Fontana, E.; Dostert, P. [Pharmacia and Upjohn, Milan (Italy)

    1997-04-01

    The synthesis of 1,6-dimethyl-8{beta}-(5-bromonicotinoyl-[{sup 14}C] oxymethyl)-10{alpha}-methoxy-ergoline ([17-{sup 14}C] nicergoline) is reported. A five-step route starting from the addition of potassium [{sup 14}C] cyanide to 1,6-dimethyl-8{beta}-chloro-10{alpha}-methoxy-ergoline yielded the expected [17- {sup 14}C] nicergoline, 97% radiochemically pure, with a specific activity of 2,23 GBq/mmol. The overall radiochemical yield was about 10%. (Author).

  12. Delta15N values of tropical savanna and monsoon forest species reflect root specialisations and soil nitrogen status.

    Science.gov (United States)

    Schmidt, S; Stewart, G R

    2003-03-01

    A large number of herbaceous and woody plants from tropical woodland, savanna, and monsoon forest were analysed to determine the impact of environmental factors (nutrient and water availability, fire) and biological factors (microbial associations, systematics) on plant delta(15)N values. Foliar delta(15)N values of herbaceous and woody species were not related to growth form or phenology, but a strong relationship existed between mycorrhizal status and plant delta(15)N. In woodland and savanna, woody species with ectomycorrhizal (ECM) associations and putative N(2)-fixing species with ECM/arbuscular (AM) associations had lowest foliar delta(15)N values (1.0-0.6 per thousand ), AM species had mostly intermediate delta(15)N values (average +0.6 per thousand ), while non-mycorrhizal Proteaceae had highest delta(15)N values (+2.9 to +4.1 per thousand ). Similar differences in foliar delta(15)N were observed between AM (average 0.1 and 0.2 per thousand ) and non-mycorrhizal (average +0.8 and +0.3 per thousand ) herbaceous species in woodland and savanna. Leguminous savanna species had significantly higher leaf N contents (1.8-2.5% N) than non-fixing species (0.9-1.2% N) indicating substantial N acquisition via N(2) fixation. Monsoon forest species had similar leaf N contents (average 2.4% N) and positive delta(15)N values (+0.9 to +2.4 per thousand ). Soil nitrification and plant NO(3)(-) use was substantially higher in monsoon forest than in woodland or savanna. In the studied communities, higher soil N content and nitrification rates were associated with more positive soil delta(15)N and plant delta(15)N. In support of this notion, Ficus, a high NO(3)(-) using taxa associated with NO(3)(-) rich sites in the savanna, had the highest delta(15)N values of all AM species in the savanna. delta(15)N of xylem sap was examined as a tool for studying plant delta(15)N relations. delta(15)N of xylem sap varied seasonally and between differently aged Acacia and other savanna

  13. Atmospheric [{sup 14}C]CO{sub 2} variations in Japan during 1982-1999 based on {sup 14}C measurements of rice grains

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Setsuko [Research Center for Radiation and Radioisotopes, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 5998570 (Japan)]. E-mail: sshibata60@yahoo.co.jp; Kawano, Eiko [Research Center for Radiation and Radioisotopes, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 5998570 (Japan); Nakabayashi, Takeshige [Research Center for Radiation and Radioisotopes, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 5998570 (Japan)

    2005-08-01

    {sup 14}C in rice grains is a useful tracer of atmospheric {sup 14}C(CO{sub 2}). {sup 14}C measurement in rice grains for 17 years during 1982-1999 reveals the following. There is negative correlation between {delta}{sup 14}C and the population densities of localities in Japan. Under-populated areas in the northern area of Japan and Okinawa remained clean in the 1990s. The {sup 14}C(CO{sub 2}) decline rates at those areas are near to that of Shauinsland. A latitudinal effect due to Chinese nuclear tests is observed in 1982. Small Seuss effects is observed at the middle latitudes in East Asia after 1995.

  14. A Brief Review of the Application of 14C in Terrestrial Carbon Cycle Studies

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T; Mcfarlane, K

    2009-10-22

    An over-arching goal of the DOE TCP program is to understand the mechanistic controls over the fate, transport, and residence time of carbon in the terrestrial biosphere. Many of the modern process and modeling studies focus on seasonal to interannual variability. However, much of the carbon on the landscape and in soils is in separate reservoirs with turnover times that are multi-decadal to millennial. It is the controls on these longer term pools or reservoirs that is a critical unknown in the face of rising GHGs and climate change and uncertainties of the terrestrial biosphere as a future global sink or source of atmospheric CO{sub 2} [eg., Friedlingstein et al., 2006; Govindasamy et al., 2005; Thompson et al., 2004]. Radiocarbon measurements, in combination with other data, can provide insight into, and constraints on, terrestrial carbon cycling. Radiocarbon (t{sub 1/2} 5730yrs) is produced naturally in the stratosphere when secondary neutrons generated by cosmic rays collide with {sup 14}N atoms [Libby 1946; Arnold and Libby, 1949]. Upon formation, {sup 14}C is rapidly oxidized to CO and then to CO{sub 2}, and is incorporated into the carbon cycle. Due to anthropogenic activities, the amount of {sup 14}C in the atmosphere doubled in the mid/late 1950s and early 1960s from its preindustrial value of {sup 14}C/{sup 12}C ratio of 1.18 x 10{sup -12} [eg., Nydal and Lovseth, 1983]. Following the atmospheric weapons test ban in 1963, the {sup 14}C/{sup 12}C ratio, has decreased due to the net isotopic exchange between the ocean and terrestrial biosphere [eg., Levin and Hessheimer, 2000] and a dilution effect due to the burning of {sup 14}C-free fossil fuel carbon, the 'Suess Effect' [Suess, 1955]. In the carbon cycle literature, radiocarbon measurements are generally reported as {Delta}{sup 14}C, which includes a correction for mass dependent fractionation [Stuiver and Polach, 1977]. In the context of carbon cycle studies radiocarbon measurements can be

  15. 14C Analysis of Protein Extracts from Bacillus Spores

    Science.gov (United States)

    Cappucio, Jenny A.; Sarachine Falso, Miranda J.; Kashgarian, Michaele; Buchholz, Bruce A.

    2014-01-01

    Investigators of bioagent incidents or interdicted materials need validated, independent analytical methods that will allow them to distinguish between recently made bioagent samples versus material drawn from the archives of a historical program. Heterotrophic bacteria convert the carbon in their food sources, growth substrate or culture media, into the biomolecules they need. The F14C (fraction modern radiocarbon) of a variety of media, Bacillus spores, and separated proteins from Bacillus spores was measured by accelerator mass spectrometry (AMS). AMS precisely measures F14C values of biological materials and has been used to date the synthesis of biomaterials over the bomb pulse era (1955 to present). The F14C of Bacillus spores reflects the radiocarbon content of the media in which they were grown. In a survey of commercial media we found that the F14C value indicated that carbon sources for the media were alive within about a year of the date of manufacture and generally of terrestrial origin. Hence, bacteria and their products can be dated using their 14C signature. Bacillus spore samples were generated onsite with defined media and carbon free purification and also obtained from archived material. Using mechanical lysis and a variety of washes with carbon free acids and bases, contaminant carbon was removed from soluble proteins to enable accurate 14C bomb-pulse dating. Since media is contemporary, 14C bomb-pulse dating of isolated soluble proteins can be used to distinguish between historical archives of bioagents and those produced from recent media. PMID:24814329

  16. Stable carbon isotope analysis ({delta}{sup 13}C values) of polybrominated diphenyl ethers and their UV-transformation products

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfelder, Natalie; Bendig, Paul [University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart (Germany); Vetter, Walter, E-mail: walter.vetter@uni-hohenheim.de [University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart (Germany)

    2011-10-15

    Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the {delta}{sup 13}C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in {sup 13}C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in {sup 13}C because of more stable bonds between {sup 13}C and bromine. As a result, the {delta}{sup 13}C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the {delta}{sup 13}C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios <1 are typical for native congeners (e.g. in DE-71) while the reversed ratio (>1) is typical of transformation products. - Highlights: > {delta}{sup 13}C values of PBDEs were determined by means of compound specific isotope analysis. > PBDEs in technical mixtures were the more depleted in {sup 13}C the higher they were brominated. > Solutions of individual PBDEs and technical PBDE mixtures were irradiated by UV light. > {delta}{sup 13}C values of irradiated PBDEs and technical PBDEs progressed diametrically. > Ratios of the {delta}{sup 13}C values were used to distinguish native from transformed PBDEs. - Diametrically progressing {delta}{sup 13}C values in technical mixtures and UV-transformation products of DE-79 may be useful for source appointment of PBDEs in environmental samples

  17. Simulation of 14C in IAP/LASG L30T63 Ocean Model

    Institute of Scientific and Technical Information of China (English)

    LI Qingquan; SHI Guangyu

    2005-01-01

    14C plays an important role in the study of ocean circulation and anthropogenic CO2. Radioactive 14C is usually used in ocean carbon circulation model to test the physical performance of model. In the present paper, a 14C model is established and coupled with the IAP/LASG L30T63 global ocean circulation model to simulate the distribution of natural 14C in oceans and the penetration and uptake of 14C in oceans after industrial revolution and nuclear bomb test. The simulation of natural 14C reveals the basic characteristics of oceanic ventilation. However, simulation value is "younger" than observation in the Pacific and Indian Oceans, and "older" than observation in the Atlantic deep ocean. The simulation of bomb 14C agrees well with GEOSECS observation, but the volume inventory and averaged penetration depth of bomb 14C in oceans are smaller than observation. The probable reasons for these discrepancies are analyzed.

  18. Characterization of 14C in Swedish light water reactors.

    Science.gov (United States)

    Magnusson, Asa; Aronsson, Per-Olof; Lundgren, Klas; Stenström, Kristina

    2008-08-01

    This paper presents the results of a 4-y investigation of 14C in different waste streams of both boiling water reactors (BWRs) and pressurized water reactors (PWRs). Due to the potential impact of 14C on human health, minimizing waste and releases from the nuclear power industry is of considerable interest. The experimental data and conclusions may be implemented to select appropriate waste management strategies and practices at reactor units and disposal facilities. Organic and inorganic 14C in spent ion exchange resins, process water systems, ejector off-gas and replaced steam generator tubes were analyzed using a recently developed extraction method. Separate analysis of the chemical species is of importance in order to model and predict the fate of 14C within process systems as well as in dose calculations for disposal facilities. By combining the results of this investigation with newly calculated production rates, mass balance assessments were made of the 14C originating from production in the coolant. Of the 14C formed in the coolant of BWRs, 0.6-0.8% was found to be accumulated in the ion exchange resins (core-specific production rate in the coolant of a 2,500 MWth BWR calculated to be 580 GBq GW(e)(-1) y(-1)). The corresponding value for PWRs was 6-10% (production rate in a 2,775 MWth PWR calculated to be 350 GBq GW(e)(-1) y(-1)). The 14C released with liquid discharges was found to be insignificant, constituting less than 0.5% of the production in the coolant. The stack releases, routinely measured at the power plants, were found to correspond to 60-155% of the calculated coolant production, with large variations between the BWR units.

  19. Direct use values of selected vegetation resources in the Okavango delta wetland

    Directory of Open Access Journals (Sweden)

    G Mmopelwa

    2011-08-01

    Full Text Available The economic benefits generated by wetlands and the costs associated with their degradation or loss are frequently overlooked. This often leads to decisions that stimulate wetland conversion and degradation.  An important step towards correcting this situation and countering this neglect is to establish the true values of a wetland’s ecosystem goods and services.  This study attempts to estimate the direct use values of native plants, such as palm leaves for basketry, grass for thatching, fuelwood, edible fruits and plant parts used by three villages adjacent to the Okavango Delta during the 2003 calendar year.  Other sources of ecosystem goods and services, such as fishing, floodplain farming and tourism, were not considered in this study.  The average annual value per household of these harvested resources is generally higher than that of similar resources found in other southern African wetlands, owing to higher consumption rates. The overall total direct use value of plant resources, including household income contributions “in kind”, was estimated at US$1 434 per household for 2003 (or US$43.41/ha. This value is almost equal to the average household financial income of US$1 416/year. The net present value of the overall benefit from the direct use of the vegetative resources is estimated at US$101.9 million. This clearly indicates the value of the use of natural resources and their contribution to livelihoods and quality of life.  This value is so significant that economic development planners ought to incorporate it into development planning. They should not conceive infrastructure development that would jeopardise the communities’ access to these natural resources without any well-developed mitigation strategy.

  20. Pyrolysis-combustion 14C dating of soil organic matter

    Science.gov (United States)

    Wang, Hong; Hackley, Keith C.; Panno, Samuel V.; Coleman, Dennis D.; Liu, Jack Chao-li; Brown, Johnie

    2003-11-01

    Radiocarbon ( 14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (δ 13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and δ 13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and δ 13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent.

  1. Carbon-14 activity of fallout in Araucaria angustifolia annual growth rings, from Arapoti, Parana State, Brazil; Atividade de {sup 14} C do 'fallout' em aneis anuais de crescimento de Araucaria angustifolia, de Arapoti - PR

    Energy Technology Data Exchange (ETDEWEB)

    Lisi, Claudio Sergio; Pessenda, Luiz Carlos Ruiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de 14 C; Tomazello Filho, Mario [Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP (Brazil). Dept. de Ciencias Florestais. Lab. de Dendrocronologia

    2000-07-01

    During the period of nuclear tests between 1950 and 1960, an input of artificial {sup 14} C (fallout effect) occurred in the natural reservoirs. {sup 14} C determinations in the Northern Hemisphere showed values of {delta}{sup 14} C up to 960 in the year of 1964. To determine the fallout {sup 14} C activity in Brazil, wood samples from Araucaria angustifolia (Bert.) O. Kuntze, Araucariaceae, were collected in Arapoti-PR (24 deg 11{sup S}, 49 deg 58{sup O}). The annual tree rings were selected by dendrochronology. The cellulose was extracted and its {sup 14} C activity determined by liquid scintillation method. The results showed a significant increase of the {delta} {sup 14} C up to 590 in 1965, about 60% higher than the natural activity, gradually decreasing after the end of nuclear tests. These results were correlated with those obtained in the Northen Hemisphere and will be used in the studies of CO{sub 2} mechanisms distribuition to the atmosphere and other natural reservoirs. (author)

  2. Was Mono Lake a 14C dump?

    Science.gov (United States)

    Maggs, William Ward

    This is a scientific story without an explanation, called a “mystery” and an “enigma” in articles by the people who discovered it. Confounded by evidence they cannot explain by natural processes, these scientists implicate human beings.One month ago in Eos, (June 7, 1988, p. 633), Wallace Broecker and Scott Stine reported abnormally high levels of radiogenic 14C in California's Mono Lake, now a National Historic Site. The only logical explanation, they proposed, is that someone secretly dumped a total of about 20 curies of 14C into the lake in two doses, sometime between 1952 and 1958 and again between 1966 and 1977. Broecker and Stine, geologists at Lamont-Doherty Geological Observatory in Palisades, N.Y., called on readers for information on the source of the 14C.

  3. Anthropogenic nitrogen input traced by means of delta15N values in macroalgae: results from in-situ incubation experiments.

    Science.gov (United States)

    Deutsch, Barbara; Voss, Maren

    2006-08-01

    The macroalgae species Fucus vesiculosus (Phaeophyta), Polysiphonia sp., and Ceramium rubrum (Rhodophyta) originally grown at an unpolluted brackish site of the southern Baltic Sea were incubated for 10 and 14 days at 12 stations along a salinity gradient in a highly polluted estuary. We have expected an adaptation of the initially low delta15N values to the higher ones within the incubation period. In addition to the macroalgae the delta15N values of NO3(-) were measured to evaluate fractionation processes of the source nitrate. Inside the estuary, delta15N-NO3(-) values were 6.2-9.7 per thousand, indicating anthropogenic nitrogen sources. The red macroalgae adequately reflected the nitrate isotope values in the surrounding waters, whereas for F. vesiculosus the results were not that clear. The reasons were assumed to be higher initial delta15N values of F. vesiculosus and presumably a too slow nitrogen uptake and growth rate. The method of macroalgae incubations seems suitable as a simple monitoring to study the influence of anthropogenic nitrogen loading in an estuarine environment.

  4. delta 15N and non-carbonate delta 13C values for two petroleum source rock reference materials and a marine sediment reference material

    Science.gov (United States)

    Dennen, Kristin O.; Johnson, Craig A.; Otter, Marshall L.; Silva, Steven R.; Wandless, Gregory A.

    2006-01-01

    Samples of United States Geological Survey (USGS) Certified Reference Materials USGS Devonian Ohio Shale (SDO-1), and USGS Eocene Green River Shale (SGR-1), and National Research Council Canada (NRCC) Certified Marine Sediment Reference Material (PACS-2), were sent for analysis to four separate analytical laboratories as blind controls for organic rich sedimentary rock samples being analyzed from the Red Dog mine area in Alaska. The samples were analyzed for stable isotopes of carbon (delta13Cncc) and nitrogen (delta15N), percent non-carbonate carbon (Wt % Cncc) and percent nitrogen (Wt % N). SDO-1, collected from the Huron Member of the Ohio Shale, near Morehead, Kentucky, and SGR-1, collected from the Mahogany zone of the Green River Formation are petroleum source rocks used as reference materials for chemical analyses of sedimentary rocks. PACS-2 is modern marine sediment collected from the Esquimalt, British Columbia harbor. The results presented in this study are, with the exceptions noted below, the first published for these reference materials. There are published information values for the elemental concentrations of 'organic' carbon (Wt % Corg measured range is 8.98 - 10.4) and nitrogen (Wt % Ntot 0.347 with SD 0.043) only for SDO-1. The suggested values presented here should be considered 'information values' as defined by the NRCC Institute for National Measurement Reference Materials and should be useful for the analysis of 13C, 15N, C and N in organic material in sedimentary rocks.

  5. The value of delta neutrophil index in young infants with febrile urinary tract infection

    Science.gov (United States)

    Lee, Jung Won; Kim, Seong Heon; Park, Se Jin; Lee, Keum Hwa; Park, Jae Hyon; Kronbichler, Andreas; Eisenhut, Michael; Kim, Ji Hong; Lee, Jong Wook; Shin, Jae Il

    2017-01-01

    Delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflects severe bacterial infections and septic condition but has not been studied in urinary tract infection (UTI). Here, we evaluated the value of DNI in predicting acute pyelonephritis (APN) or vesicoureteral reflux (VUR) using the data of 288 patients. Conventional inflammatory markers (white blood cell [WBC] count, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), and DNI were measured. WBC, CRP, ESR and DNI were higher in APN than in lower UTI (p < 0.01). Multiple logistic-regression analyses showed that DNI was a predictive factor for areas of lack of uptake on dimercaptosuccinic acid (DMSA) scans (P < 0.01). The area under the receiver operating characteristic (AUC) was also high for DNI (0.622, 95% CI 0.558–0.687, P < 0.01) as well as for CRP (0.731, 95% CI 0.673–0.789, P < 0.01) for the prediction of DMSA defects. DNI demonstrated the highest area under the ROC curve for diagnosis of VUR (0.620, 95% CI 0.542–0.698, P < 0.01). To the best of our knowledge, this is a first study demonstrating that DNI can be used as a diagnostic marker to distinguish APN from lower UTI and function as a diagnostic marker indicative of VUR compared to other conventional markers. PMID:28169298

  6. Maternal attitudes and values to youth sexuality-related activities in Delta State, Nigeria.

    Science.gov (United States)

    Okonkwo, I P; Ilika, A I

    2003-09-01

    This descriptive study assessed maternal attitudes to youth-related activities in Delta State. Using an adapted questionnaire, 300 women with adolescent children were chosen through a multistage sampling technique and relevant data obtained regarding their socio-economic status, perceptions and values as well as their knowledge of basic reproductive health concerns. Most of the women interviewed (95%), believed it was very important that young people completed secondary education and another 72% said they would normally set rules in their homes regarding what young people should read or watch. Sixty-seven percent of those studied, discussed sexuality issues regularly with their adolescent children, though only 46.4% of them were comfortable discussing these issue and about 50% admitted having enough information in such discussions. Another 76% of the women would approve of their children receiving reproductive health information and service including contraceptive condoms. The mothers studied believed that guided reproductive health information and services should be routinely provided for young people. The findings strongly suggest that the mothers who are important stakeholders in Adolescent Health would most likely be supportive of youth programmes. Most of the findings differ from those of other studies, and a qualitative study would be carried out to identify the reasons for these interesting findings.

  7. Excretion of radioactivity following the intraperitoneal administration of /sup 14/C-DDT, /sup 14/C-DDD, /sup 14/C-DDE and /sup 14/C-DDMU to the rat and Japanese Quail

    Energy Technology Data Exchange (ETDEWEB)

    Fawcett, S.C. (Univ. of Surrey, Guildford, England); Bunyan, P.J.; Huson, L.W.; King, L.J.; Stanley, P.I.

    1981-09-01

    A study in progress to examine the metabolic fate of DDT in birds and mammals is discussed. The first phase of the study, which is reported in this article, has been to establish the rate of excretion of ratioactivity following the intraperitoneal administrations of /sup 14/C-DDT, /sup 14/C-DDE, /sup 14/C-DDD, and /sup 14/C-DDMU to male rats and male Japanese quail. The mean values from the three animals in each experimental group for the amount of radioactivity excreted daily are given, and it was found that the rats excreted the radioactivity administered as DDT, DDD, and DDE substantially faster than did the quail. DDMU was excreted relatively rapidly and at similar rates. This finding suggests that apparent differences in the rates of excretion of DDT by birds and mammals probably arise from differences in the conversion of DDT to DDD or DDE or in the degradation of these metabolites to DDMU. The Japanese quail differ from the rats in excreting substantial amounts of unchanged DDT, DDE, and DDD, which probably reflects the inability of the Japanese quail to readily metabolise these compounds.

  8. Reviewing the Mid-First Millennium BC {sup 14}C 'warp' using {sup 14}C/bristlecone pine data

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.E., E-mail: retaylor@ucr.edu [Department of Anthropology, University of California, Riverside, Riverside, CA (United States); Cotsen Institute of Archaeology, University of California, Los Angeles, CA (United States); Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, University of California, Irvine, CA (United States); Southon, John [Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, University of California, Irvine, CA (United States)

    2013-01-15

    AMS-based {sup 14}C measurements have been obtained on 53 dendrochronologically-dated Bristlecone pine (Pinus longaeva) wood samples in decadal increments spanning 2300-2750 cal BP with particular interest focused on the decades centered on 2405 cal BP and 2625 cal BP. In general, there is overall agreement with the current IntCal04/09 consensus calibration curve for this period. For the 2400-2410 cal BP interval, our Bristlecone-based {sup 14}C value is consistent with the {sup 14}C value obtained by Belfast on Irish oak for that decade but not on German oak values obtained by Seattle. Our {sup 14}C value for the 2620-2630 cal BP interval is consistent with the German oak (Heidelberg)-based {sup 14}C decadal value. The {sup 10}Be-based reconstruction of {sup 14}C variations over the 2620-2630 cal BP interval also supports the Heidelberg data although clearly additional clarifications are required before the current tree ring-based {sup 14}C and ice core-based {sup 10}Be data for this interval can be accurately interpreted and valid inferences obtained.

  9. High precision {sup 14}C AMS at CIRCE

    Energy Technology Data Exchange (ETDEWEB)

    Terrasi, Filippo [Dipartimento di Scienze Ambientali, II Universita di Napoli, Via Vivaldi 43, Caserta 81100 (Italy); CIRCE, INNOVA, Via Campi Flegrei 34, Pozzuoli 80078 (Italy)], E-mail: filippo.terrasi@unina2.it; De Cesare, Nicola [Dipartimento di Scienze della Vita, II Universita di Napoli, Via Vivaldi 43, Caserta 81100 (Italy); CIRCE, INNOVA, Via Campi Flegrei 34, Pozzuoli 80078 (Italy); D' Onofrio, Antonio; Lubritto, Carmine; Marzaioli, Fabio [Dipartimento di Scienze Ambientali, II Universita di Napoli, Via Vivaldi 43, Caserta 81100 (Italy); CIRCE, INNOVA, Via Campi Flegrei 34, Pozzuoli 80078 (Italy); Passariello, Isabella [CIRCE, INNOVA, Via Campi Flegrei 34, Pozzuoli 80078 (Italy); Rogalla, Detlef [Institut fuer Experimentalphysik III, Ruhr-Universitaet Bochum, Bochum D-44780 (Germany); Sabbarese, Carlo [Dipartimento di Scienze Ambientali, II Universita di Napoli, Via Vivaldi 43, Caserta 81100 (Italy); CIRCE, INNOVA, Via Campi Flegrei 34, Pozzuoli 80078 (Italy); Borriello, Gianluca; Casa, Giovanni; Palmieri, Antonio [Dipartimento di Scienze Ambientali, II Universita di Napoli, Via Vivaldi 43, Caserta 81100 (Italy)

    2008-05-15

    The CIRCE AMS system started operation in March 2005. The measurement of isotopic ratios {sup 14}C/{sup 12}C in samples of archaeological and environmental interest has rapidly attained high precision and accuracy levels in routine operation. The results of the intercomparison campaign in the framework of the VIRI program, as well as the outcome of a statistical analysis of the about 200 control measurements performed with standard samples, have shown the capability of the whole system for high precision measurements ({delta}R/R < 0.3%), allowing systematic investigations in both archaeological and environmental sciences. {sup 26}Al AMS has been implemented for the measurement of the astrophysically relevant {sup 25}Mg(p,{gamma}){sup 26}Al reaction cross section, while a beam line is under construction for the measurement of actinides isotopic ratios.

  10. Delta Procalcitonin Is a Better Indicator of Infection Than Absolute Procalcitonin Values in Critically Ill Patients: A Prospective Observational Study

    Directory of Open Access Journals (Sweden)

    Domonkos Trásy

    2016-01-01

    Full Text Available Purpose. To investigate whether absolute value of procalcitonin (PCT or the change (delta-PCT is better indicator of infection in intensive care patients. Materials and Methods. Post hoc analysis of a prospective observational study. Patients with suspected new-onset infection were included in whom PCT, C-reactive protein (CRP, temperature, and leukocyte (WBC values were measured on inclusion (t0 and data were also available from the previous day (t-1. Based on clinical and microbiological data, patients were grouped post hoc into infection- (I- and noninfection- (NI- groups. Results. Of the 114 patients, 85 (75% had proven infection. PCT levels were similar at t-1: I-group (median [interquartile range]: 1.04 [0.40–3.57] versus NI-group: 0.53 [0.16–1.68], p=0.444. By t0 PCT levels were significantly higher in the I-group: 4.62 [1.91–12.62] versus 1.12 [0.30–1.66], p=0.018. The area under the curve to predict infection for absolute values of PCT was 0.64 [95% CI = 0.52–0.76], p=0.022; for percentage change: 0.77 [0.66–0.87], p<0.001; and for delta-PCT: 0.85 [0.78–0.92], p<0.001. The optimal cut-off value for delta-PCT to indicate infection was 0.76 ng/mL (sensitivity 80 [70–88]%, specificity 86 [68-96]%. Neither absolute values nor changes in CRP, temperature, or WBC could predict infection. Conclusions. Our results suggest that delta-PCT values are superior to absolute values in indicating infection in intensive care patients. This trial is registered with ClinicalTrials.gov identifier: NCT02311816.

  11. Extraction of in situ cosmogenic 14C from olivine

    Science.gov (United States)

    Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

    2010-01-01

    Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona

  12. {sup 14}C content in aerosols in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, V.; Solís, C.; Chávez, E.; Andrade, E.; Ortiz, M.E.; Huerta, A.; Aragón, J.; Rodríguez-Ceja, M. [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México, D.F. 01000 (Mexico); Martínez, M.A. [Facultad de Ciencias, Universidad Nacional Autónoma de México (Mexico); Ortiz, E. [Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, C. P. 02200 México, D.F. (Mexico)

    2016-03-15

    {sup 14}C-AMS of total carbon was determined in aerosols (PM{sub 10} fraction), collected in Mexico City during two weeks from 21 November to 3 December 2012. Other tracers such as total carbon (TC), organic carbon (OC), elemental carbon (EC) and trace element contents were also determined. F{sup 14}C values varied from 0.39 to 0.48 with an average of 0.43. These values are slightly lower than those previously obtained for PM{sub 2.5} in 2003 and 2006 and reflect a high contribution of fossil CO{sub 2} to the carbonaceous matter in aerosols from Mexico City. In contrast, from 2006 to 2012 PM{sub 10} increased; EC, Ca, Ti and Fe concentrations remained constant, while OC, TC and K concentrations decreased. The use of potassium as an indicator of biomass burning showed that this source was negligible during this campaign. Combined analytical approaches allowed us to distinguish temporal variations of anthropogenic and natural inputs to the F{sup 14}C.

  13. Possible cluster preformation in the 14C decay of 223Ra

    Science.gov (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Ardisson, G.

    1990-08-01

    A recent experiment on the 14C fine structure has shown that the branching ratio to 209Pb ground state is quite different from the one predicted by the various models of cluster emission. Assuming that the 14C is preformed in the 223Ra nucleus, we have calculated the hindrance factor F14C of the three 14C branches to 209Pb states with a barrier penetrability approximated by a square-well Coulomb potential. The F14C=3.9 and 4.6 values found for the 14C transitions to the two excited states at 779 keV (Iπ=11/2+) and 1423 keV (Iπ=15/2-), respectively, reveal that the cluster formation amplitudes in both transitions are close to those of the 222Ra and 224Ra 14C decays. Such values could be the result of ||nlj> shell-model components common to both the wave functions of the octupole deformed 223Ra nucleus and of the two first excited states of 209Pb spherical nucleus. The high hindrance factor F14C=583 of the 14C branch to the 209Pb ground state (Iπ=9/2+) could reveal the absence of ||1g9/2> shell-model component in the 223Ra wave function.

  14. May {sup 14}C be used to date contemporary art?

    Energy Technology Data Exchange (ETDEWEB)

    Fedi, M.E., E-mail: fedi@fi.infn.it [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Caforio, L. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Mando, P.A. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica e Astronomia, Universita di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy); Petrucci, F. [Dipartimento di Fisica, Universita di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); INFN Sezione di Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Taccetti, F. [INFN Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (Italy)

    2013-01-15

    The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, {sup 14}C concentration in the atmosphere had strongly increased due to nuclear explosions, reaching its maximum value in 1963-1965. After the Nuclear Test Ban Treaty, {sup 14}C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to 'precisely' date works of contemporary art, with the aim at identifying possible fakes. We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured {sup 14}C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the {sup 14}C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured. In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.

  15. May 14C be used to date contemporary art?

    Science.gov (United States)

    Fedi, M. E.; Caforio, L.; Mandò, P. A.; Petrucci, F.; Taccetti, F.

    2013-01-01

    The use of radiocarbon in forensics is by now widespread, thanks to the so-called bomb peak, which makes it possible to perform high-precision dating. Since 1955, 14C concentration in the atmosphere had strongly increased due to nuclear explosions, reaching its maximum value in 1963-1965. After the Nuclear Test Ban Treaty, 14C started to decrease as a consequence of the exchanges between atmosphere and the other natural carbon reservoirs. Nowadays, it is still slightly above the pre-bomb value. The work presented in this paper is based on the idea of exploiting the bomb peak to “precisely” date works of contemporary art, with the aim at identifying possible fakes. We analysed two kinds of materials from the 20th century: newspapers and painting canvases. Newspaper samples were taken because they might in principle be considered to represent dated samples (considering the date on the issues). Our data (28 samples) show a trend similar to atmospheric data in the literature, although with some differences; the paper peak is flatter and shifted towards more recent years (about five years) with respect to the atmospheric data. This can be explained by taking paper manufacturing processes into account. As to the canvas samples, the measured 14C concentrations were generally reasonably consistent with the expected concentrations (based on the year on the paintings). However, this does not indicate that the interpretation of the results is simpler and more straightforward. Obviously, we only measure the 14C concentration of the fibre used for the canvas, which does not necessarily measure the date the painting was manufactured. In this paper, sample preparation and experimental results will be discussed, in order to show the potential as well as the limitations of radiocarbon to date contemporary art.

  16. Atomic diffusion in metal poor stars. The influence on the Main Sequence fitting distance scale, subdwarfs ages and the value of Delta Y/ Delta Z

    Science.gov (United States)

    Salaris, M.; Groenewegen, M. A. T.; Weiss, A.

    2000-03-01

    , the age dispersion, the age-metallicity relation for Halo subdwarfs, as well as the value of the helium enrichment ratio Delta Y/Delta Z obtained from the width of the empirical Halo subdwarfs MS, are all significantly modified when the properly calibrated isochrones with diffusion are used.

  17. Ecosystem Service Value for the Common Reed Wetlands in the Liaohe Delta, Northeast China

    DEFF Research Database (Denmark)

    Ye, Siyuan; Laws, Edward A.; Costanza, Robert

    2016-01-01

    The largest reed field in the world, with an area of 1000 km2 in 1953, is located in the Liaohe Delta, which lies in the five-point-in-a-line economic strategic zone of northeastern China. However, the area of reeds has declined dramatically in recent years to accommodate oil field infrastructure...

  18. Forensic applications of 14C at CIRCE

    Science.gov (United States)

    Marzaioli, F.; Fiumano, V.; Capano, M.; Passariello, I.; Cesare, N. De.; Terrasi, F.

    2011-12-01

    The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon ( 14C) AMS measurements (Δ R/ R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS 14C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the "Acerenza portrait" is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci. Bomb- 14C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2σ) of 1459-1524 AD (57% relative probability), 1571-1631 AD interval (42

  19. Applications of 14C-AMS in biomedical sciences (Bio-14C-AMS)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Accelerator mass spectrometry (AMS) is an ultrasensitive measure for tracing 14C labeled molecules in vivo or detecting the biomarker for assessment of carcinogenesis. In this review, basic principles, wide applications and new progresses of 14C-bio-AMS are presented. It has been a new advanced tool for measuring the adduction of biologcial molecules with xenobiotics, including carcinogens, drugs, agrochemicals, nicotine, etc. The successful applications have proven the effectiveness of AMS to assessing cancer risk, screening drug toxicity and studying nutrients uptake. In particular, AMS is characterized by measuring xenobiotics at very low dose levels relevant to human environmental exposure. It is sensitive and precise to an attomole (10-18 mole) or less of 14C per mg carbon. Although it has some shortcomings, undoubtedly, AMS possesses an evident merit of high sensitivity and will have widespread applications in the biomedical sciences.

  20. Extreme value analysis of annual maximum water levels in the Pearl River Delta, China

    Institute of Scientific and Technical Information of China (English)

    Qiang ZHANG; Chong-Yu XU; Yongqin David CHEN; Chun-ling LIU

    2009-01-01

    We analyzed the statistical properties of water level extremes in the Pearl River Delta using five probability distribution functions. Estimation of para-meters was performed using the L-moment technique.Goodness-of-fit was done based on Kolmogorov-Smirnov's statistic D (K-S D). The research results indicate that Wakeby distribution is the best statistical model for description of statistical behaviors of water level extremes in the study region. Statistical analysis indicates that water levels corresponding to different return periods and associated variability tend to be larger in the landward side of the Pearl River Delta and vice versa. A ridge characterized by higher water level can be identified expanding along the West River and the Modaomen channel, showing the impacts of the hydrologic process of the West River basin. Trough and higher grades of water level changes can be detected in the region drained by Xi'nanyong channel, Dongping channel, and mainstream of Pearl River. The Pearl River Delta region is character-ized by low-lying topography and a highly-advanced socio-economy, and is heavily populated, being prone to flood hazards and flood inundation due to rising sea level and typhoons. Therefore, sound and effective counter-measures should be made for human mitigation to natural hazards such as floods and typhoons.

  1. Incorporation of Socio-Cultural Values in Damage Assessment Valuations of Contaminated Lands in the Niger Delta

    Directory of Open Access Journals (Sweden)

    Victor A. Akujuru

    2014-07-01

    Full Text Available Damages on contaminated land have been mostly assessed for developments subsisting on the land, neglecting the goods and services derived from the land which possess only socio-cultural values. This paper aims to ascertain the importance of socio-cultural values in the total economic value of contaminated land, drawing from the experience of a coastal community oil spillage in the Niger Delta. The paper examines what constitutes a valuable interest on contaminated land and how socio-cultural factors are valued in the damage assessment process. After reviewing the literature and decided cases, a questionnaire survey was conducted and a sample valuation report was analysed. It is concluded that there exists a socio-cultural interest on contaminated land which professional valuers do not reflect in damage assessment claims. It is recommended that any comprehensive damage assessment requires the incorporation of socio-cultural values in the valuations.

  2. Bioconversion of. cap alpha. -(/sup 14/C)Zearalenol and. beta. -(/sup 14/C)Zearalenol into (/sup 14/C)Zearalenone by Fusarium roseum Gibbosum

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, K.E.; Hagler, W.M. Jr.; Hamilton, P.B.

    1984-06-01

    Cultures of Fusarium roseum Gibbosum on rice were treated with (/sup 14/C)zearalenone, ..cap alpha..-(/sup 14/C)zearalenol, or ..beta..-(/sup 14/C)zearalenol to determine whether a precursor-product relationship exists among these closely related fungal metabolites. Culture extracts were purified by silica gel column chromatography and fractionated by high-pressure liquid chromatography, and the level of radioactivity was determined. Within 7 days, the ..beta..-(/sup 14/C)zearalenol was converted to zearalenone, and no residual ..beta..-(/sup 14/C)zearalenol was detectable. Most of the ..cap alpha..-(/sup 14/C)zearalenol added was also converted into zearalenone within 14 days. In cultures treated with (/sup 14/C)zearalenone, no radioactivity was noted in any other components.

  3. Forensic applications of {sup 14}C at CIRCE

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, F., E-mail: fabio.marzaioli@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Fiumano, V., E-mail: vittoriofiumano85@libero.it [CIRCE, Dipartimento di Scienze della Vita, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Capano, M., E-mail: manuela.capano@unina2.it [CIRCE, Dipartimento di Studio delle Componenti Culturali del Territorio, Seconda Universita degli Studi di Napoli and INNOVA, Piazza S. Francesco, 81055 Santa Maria Capua Vetere, Caserta (Italy); Passariello, I., E-mail: isabella.passariello@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Cesare, N.De., E-mail: nicola.decesare@unina2.it [CIRCE, Dipartimento di Scienze della Vita, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy); Terrasi, F., E-mail: filippo.terrasi@unina2.it [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli and INNOVA, Via Vivaldi 43, 81100 Caserta (Italy)

    2011-12-15

    The decreasing trend of the radiocarbon pulse produced during the atmospheric tests of nuclear weapons (bomb-carbon) coupled with high sensitivity accelerator mass spectrometry (AMS) measurements, drastically increased the precision of radiocarbon age determinations since the second part of the sixties, allowing the application of radiocarbon AMS to a wide range of studies previously not directly involving conventional radiocarbon dating (i.e. food authenticity, forensic, biochemistry). In the framework of authenticity evaluation of artworks, high precision radiocarbon ({sup 14}C) AMS measurements ({Delta}R/R < 0.3%) reduce the conventional uncertainty of the dating to few decades, allowing precise age estimation of materials containing carbon (C). The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) during its activity on AMS {sup 14}C dating achieved high precision measurements opening the opportunity to these kinds of applications. This paper presents the main results obtained from radiocarbon measurements on a set of bone samples analyzed for the determination of the post-mortem interval in the framework of an unsolved case investigated by the Rome prosecutor office. The chronological characterization of the wooden support of the 'Acerenza portrait' is also presented with the aim to evaluate its age and to further investigate the possibility to attribute this artwork to Leonardo da Vinci. Bomb-{sup 14}C dating on the lipid and collagen fractions of bones allows the evaluation of the year of the death of the individuals by means of ad hoc calibration data sheet with the typical few years precision and difference between collagen apparent age and the year of death appeared in agreement with the age of one individual estimated by dating of tooth collagen. Conventional radiocarbon dating on both wood and wood extracted cellulose leads to an estimation of the portrait wood board age (2{sigma}) of 1459-1524 AD (57% relative

  4. The distribution of Δ{sup 14}C in Korea from 2010 to 2013

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H., E-mail: junghun@kigam.re.kr [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of); Hong, W. [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of); Xu, X. [Keck/CCAMS Lab, 3327 Croul Hall, University of California, Irvine, CA 92697 (United States); Park, G.; Sung, K.S.; Sung, Kilho; Lee, Jong-geol; Nakanishi, T.; Park, Hyo-Seok [Korea Institute of Geoscience and Mineral Resources (KIGAM), 124 Gwahang-no. Yuseong, Daejeon 305-350 (Korea, Republic of)

    2015-10-15

    Δ{sup 14}C values of leaves of a deciduous tree record to those of atmospheric CO{sub 2} within error and were used to map out Δ{sup 14}C distribution in Korea. We collected ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples in mid-June to early July from 2009 to 2013 in Korea to obtain the regional distribution of Δ{sup 14}C. Commonly CO{sub 2} emitted from fossil fuel consumption dilutes atmospheric {sup 14}C, while operations and accidents at nuclear power plants can increase it. The distribution maps of Δ{sup 14}C from 2010 to 2013 in Korea shows that Δ{sup 14}C values in the northwestern and southeastern parts of Korea are lower than those of the other parts of Korea, which is consistent with the population and industry patterns. Decrease rates of annually averaged Δ{sup 14}C values in Korea over the study period are larger than those of Pt. Barrow, Alaska, USA (71.3°N, 156.5°W), so the difference between them and those of Pt. Barrow, Alaska, USA became larger annually. This may be due to the increase in fossil fuel consumption in Korea and China. The decrease rate between 2010 and 2011 was smaller than in other years. This could be the effect of the Fukushima power plant accident which occurred in March 11, 2011, but further study is needed to clarify it.

  5. Pharmacokinetics of 14C CDP-choline.

    Science.gov (United States)

    Dinsdale, J R; Griffiths, G K; Rowlands, C; Castelló, J; Ortiz, J A; Maddock, J; Aylward, M

    1983-01-01

    The absorption, metabolism and excretion of cytidine diphosphate choline (CDP-choline, citicoline, Somazina) were investigated in six adult healthy subjects after a single oral dose of 300 mg of the 14C-labelled compound. The compound was well tolerated by the subjects. Absorption was virtually complete with less than 1% of the dose being found in the faeces during the 5-day collection period. Two peaks were found in the plasma radioactivity time profile: the first at 1 h, and a second larger peak at 24 h post-dose. Elimination of the ingested dose occurred via respiratory CO2 and through urinary excretion; the former predominating, and both routes exhibited biphasic patterns characterized by an early phase followed by slower decline. It is postulated that in the healthy human subject CDP-choline is metabolized in the gut wall and in the liver; the products arising from the compound's extensive hepatic metabolism being subsequently available for diverse biosynthetic pathways, tissue metabolism, and excretion.

  6. Development of Evaluation Models for Estimation of Economic Values of Natural Gas Fractionation in the Niger Delta

    Directory of Open Access Journals (Sweden)

    Udie, A. C.

    2016-06-01

    Full Text Available Natural gas fractionation components and economic values models have been developed in the Niger Delta. The importance is to enhance diversifying utilization, reduce gas flaring, creates fast development, impacts on building the Nation’s economy, industrialization and jobs creation in the country. This was possible calculated average Natural gas values, weight, heating value, specific gravity and ratio of the gas components (LNG, LPG and condensate. The resulted fractionation ratio is 85.76% of LNG, 11.61% of LPG and 2.28% of condensate (liquid with a revenue generation of LNG USD1.85/SCF, LPG N 0.41/SCF and N 0.38/SCF. The revenue per give time depends on demand and supply.

  7. Synthesis of /sup 14/C-Bucromarone succinate and hydrochloride

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, C.; Verny, M.; Maurizis, J.-C.; Payard, M.; Faurie, M.

    1986-08-01

    /sup 14/C-Bucromarone, 2-(4-(3-N,N dibutylamino propoxy) 3,5-dimethyl benzoyl) chromone, was synthesized from (U-/sup 14/C) oxalic acid. The labelling takes place at the first step of the synthesis, giving /sup 14/C-Bucromarone succinate (specific activity 7.45 mCi/mmol) and /sup 14/C-Bucromarone hydrochloride (specific activity 7.5 mCi/mmol).

  8. Preparation of 14C Radiolabelled Sodium Carboxymethyl Cellulose

    Institute of Scientific and Technical Information of China (English)

    CHEN; Bao-jun; YANG; Hong-wei; LI; Shuai

    2013-01-01

    Carboxymethyl cellulose(CMC)is a kind of cellulose derivative.CMC has wide applications,including food,daily chemicals,pharmaceutical industry and chemical industry,etc.In order to study the metabolism of CMC,the sodium carboxymethyl cellulose was labelled with 14C.The carboxymethyl cellulose was labelled with 14C by treatment with alkalized cellulose and 14C-

  9. {sup 14}C AMS dating Yongcheon cave

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H., E-mail: jefflee@snu.ac.kr [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Choe, K. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, J.C. [Dept. of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Choi, S.H.; Kang, J.; Song, S.; Song, Y.M. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Jang, J.G. [Jeju National Museum, Jeju 690-782 (Korea, Republic of)

    2013-01-15

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340-880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The {sup 14}C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  10. {sup 14}C. The future of the past; {sup 14}C. De toekomst van het verleden

    Energy Technology Data Exchange (ETDEWEB)

    Mook, W.G.; Van der Plicht, J.; Leijenaar, D. [comps.

    1994-12-31

    In this catalogue an overview is given of the impact that {sup 14}C surveys had and still have on a broad spectrum of disciplines, e.g. archaeology, geology, paleobotany, hydrology and oceanography, in particular on the basis of results from the authors` laboratory. Next to the uses of carbon 14 attention is paid to the advantages of the new Accelerator Mass Spectrometer (AMS). 28 figs.

  11. 14C-丁草胺、14C-毒死蜱和14C-DDT在日本林蛙中的生物学行为%BEHAVIORS OF 14C-BUTACHLOR,14C-CHLORPYRIFOS AND 14C-DDT IN Rana japonica japonica Guenther

    Institute of Scientific and Technical Information of China (English)

    张奕强; 张海清; 钟创光; 赵小奎; 陈舜华

    2002-01-01

    用同位素示踪技术研究了14C-丁草胺、14C-毒死蜱和14C-DDT在日本林蛙(Rana japonica japonica Guenther)中的生物学行为.结果发现,14C-丁草胺、14C-毒死蜱和14C-DDT在24h后分布到青蛙的各个器官组织,并分别以胆囊、小肠、小肠为它们的特异性浓集器官.与胆囊或小肠的14C放射性活度比较,其它器官组织中的要小得多.14C-DDT在日本林蛙中较难降解,24h后DDT母体在肝和脂肪组织中占DDT代谢物的54.6%和88.4%.青蛙中的14C-丁草胺、14C-毒死蜱和14C-DDT可被丙酮提取,但三者之间以及在青蛙的器官之间有差异.%The research on the behaviors of 14C-butachlor, 14C-chlorpyrifos and 14C-DDT in the frog Rana japonica japonica Guenther was carried out. After administrated per os to the frogs in doses of 380,347,363 Bq/g, 14C-butachlor, 14C-chlorpyrifos and 14C-DDT, were distributed respectively to various organs within 24 h with specific accumulating organs as gallbladder, intestine and intestine, relevantly to the pesticides described. Compared to that in gallbladder and intestine, the radioactivity of many organs was extremely low, and this might due to the characters of the pesticides. Analysis of the metabolites of 14C-DDT in frog at 24th hr demonstrated that DDT was difficult to be degraded. Most 14C-butachlor, 14C-chlorpyrifos 14C-DDT in liver and fat or ovary of frog was extractable with acetone. However, there were some differences between the pesticides, and the organs as well. And 14C-butachlor, 14C-chlorpyrifos or 14C-DDT were better bound in liver than in fat.

  12. Search for a fine structure in the 14C decay of 222Ra

    Science.gov (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Dalmasso, J.; Ardisson, G.

    1991-06-01

    The 14C decay of 222Ra has been reinvestigated, using an 85 MBq activity 230U source radiochemically separated, a Si barrier detector, and a superconducting magnetic spectrometer. In a 16 days counting run, 210 14C events were recorded. The 14C particles energy value 30.930+/-0.090 MeV was found and an upper limit b<=2×10-12 was estimated for the 14C branching ratio to the 208Pb first excited state; the branching-ratio value to the 208Pb ground state, thus equal to the total branching ratio, was found to be b=λc/λα=(2.31+/-0.31)×10-10.

  13. New measurement of exotic decay of 225Ac by 14C emission

    Science.gov (United States)

    Guglielmetti, A.; Bonetti, R.; Ardisson, G.; Barci, V.; Giles, T.; Hussonnois, M.; Le Du, J. F.; Le Naour, C.; Mikheev, V. L.; Pasinetti, A. L.; Ravn, H. L.; Tretyakova, S. P.; Trubert, D.

    The branching ratio of 225Ac decay by emission of 14C was remeasured under improved experimental conditions by using a radioactive source produced at the ISOLDE mass-separator at CERN and a nuclear track detector technique. The result, B = λ14C/λα = (4.5+/-1.4)10-12, is consistent with the anomalously high value obtained in the 1993 experiment, thus confirming the importance of nuclear-structure effects in this exotic decay.

  14. Macroalgae delta N-15 values in well-mixed estuaries: Indicator of anthropogenic nitrogen input or macroalgae metabolism?

    OpenAIRE

    Raimonet, Melanie; Guillou, Gael; Mornet, Francoise; Richard, Pierre

    2013-01-01

    Although nitrogen stable isotope ratio (delta N-15) in macroalgae is widely used as a bioindicator of anthropogenic nitrogen inputs to the coastal zone, recent studies suggest the possible role of macroalgae metabolism in delta N-15 variability. Simultaneous determinations of delta N-15 of dissolved inorganic nitrogen (DIN) along the land sea continuum, inter-species variability of delta N-15 and its sensitivity to environmental factors are necessary to confirm the efficiency of macroalgae de...

  15. Kinetic study of benzyl [1-14C]acetate as a potential probe for astrocytic energy metabolism in the rat brain: Comparison with benzyl [2-14C]acetate.

    Science.gov (United States)

    Okada, Maki; Yanamoto, Kazuhiko; Kagawa, Tomohiko; Yoshino, Keiko; Hosoi, Rie; Abe, Kohji; Zhang, Ming-Rong; Inoue, Osamu

    2016-02-01

    Brain uptake of [(14)C]acetate has been reported to be a useful marker of astrocytic energy metabolism. In addition to uptake values, the rate of radiolabeled acetate washout from the brain appears to reflect CO2 exhaustion and oxygen consumption in astrocytes. We measured the time-radioactivity curves of benzyl [1-(14)C]acetate ([1-(14)C]BA), a lipophilic probe of [1-(14)C]acetate, and compared it with that of benzyl [2-(14)C]acetate ([2-(14)C]BA) in rat brains. The highest brain uptake was observed immediately after injecting either [1-(14)C]BA or [2-(14)C]BA, and both subsequently disappeared from the brain in a single-exponential manner. Estimated [1-(14)C]BA washout rates in the cerebral cortex and cerebellum were higher than those of [2-(14)C]BA. These results suggested that [1-(14)C]BA could be a useful probe for estimating the astrocytic oxidative metabolism. The [1-(14)C]BA washout rate in the cerebral cortex of immature rats was lower than that of mature rats. An autoradiographic study showed that the washout rates of [1-(14)C]BA from the rat brains of a lithium-pilocarpine-induced status epilepticus model were not significantly different from the values in control rat brains except for the medial septal nucleus. These results implied that the enhancement of amino acid turnover rate rather than astrocytic oxidative metabolism was increased in status epilepticus. © The Author(s) 2015.

  16. Fish age validation study with bomb-produced radiocarbon (14C) conducted on yellowfin sole (Limanda aspera) and northern rockfish (Sebastes polyspinis) by Alaska Fisheries Science Center, Fisheries Monitoring and Analysis division from 1987-01-01 to 2004-01-01 (NCEI Accession 0134853)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish age validation with bomb-produced radiocarbon (14C) requires a known-age Delta14C reference chronology spanning the era of a marine increase in bomb-produced...

  17. 14C levels in the vicinity of the Fukushima Dai-ichi Nuclear Power Plant prior to the 2011 accident

    DEFF Research Database (Denmark)

    Xu, Sheng; Cook, Gordon T.; Cresswell, Alan J.

    2016-01-01

    A 50-year-old Japanese cedar (Cryptomeria japonica) from Okuma, ∼1 km southwest of the Fukushima Dai-ichi Nuclear Power Plant, was cored and each annual ring was analysed for 14C. The 14C specific activity values varied from 330.4 Bq kg−1 C in the tree ring formed in 1971 to 231.2 Bq kg−1 C...... discharges from the reactors during their normal operations. In addition, the specific activities are positively correlated with the annual electricity generation values. The excess 14C specific activities were ... and consequently no significant radiological impact of atmospheric 14C discharges from the FDNPP during the entire period of normal operations. Additionally, no 14C pulse in activity can be observed in the year 2011 ring. This might be caused by a limited 14C release from the damaged reactors during the accident...

  18. ( sup 14 C)urea breath test for diagnosis of Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Ormand, J.E.; Talley, N.J.; Carpenter, H.A.; Shorter, R.G.; Conley, C.R.; Wilson, W.R.; DiMagno, E.P.; Zinsmeister, A.R.; Phillips, S.F. (Mayo Clinic, Rochester, MN (USA))

    1990-07-01

    H. pylori is a potent urease producer, a characteristic that has been exploited in the development of the (14C)- and (13C)urea breath tests. The prevalence of H. pylori infection also is known to increase with advancing age; however, the individual patient's age has not routinely been considered when interpreting urea breath test results. The aim of this study was to validate a short, age-adjusted (14C)urea breath test for use in diagnosing H. pylori infections. Forty-one subjects (28 volunteers, 13 patients) underwent esophagogastroduodenoscopy with biopsies. Subjects were defined as being H. pylori-positive if histology or culture was positive. In addition, all subjects completed a 120-min (14C)urea breath test. A logistic regression analysis adjusting for age was used to estimate the probability of H. pylori positivity as a function of the 14C values generated. Sixteen subjects were H. pylori-positive, and 25 were H. pylori-negative. The 14C values generated between 15 and 80 min were found to be equally predictive in identifying H. pylori-positive subjects. Advancing age was associated with a higher probability of H. pylori-positivity. By taking advantage of the statistical probabilities, older patients could be accurately diagnosed with H. pylori at lower 14C values. We found that (14C)urea breath test to be both a sensitive and specific test that can be abbreviated to a 30-min examination (total test time). Moreover, our mathematical model indicates that a patient's age should be considered in order to optimize interpretation of the (14C)urea breath test, although further observations are needed to confirm this model.

  19. A Critical Analysis of Climate Change Factors and its Projected Future Values in Delta State, Nigeria

    Directory of Open Access Journals (Sweden)

    Emaziye, P. O., R. N. Okoh

    2012-06-01

    Full Text Available The study focused on the critical analysis of climate change factors (temperature and rainfall and its projected future values in the state. The main objective was to determine the trends of climate change factors (temperature and rainfall. And the specific objective was to determine the projected future trends of climate change factors in the state. Multistage sampling procedure was used in the random selection of states, local government, communities and rural households for the research study. Annual mean time series data of temperature and rainfall were collected from Nigerian Meteorological Agency (NIMET. Data were also obtained from structure questionnaire survey. The collected data were analyzed using descriptive statistics, trend analysis and growth model. The study reveals that there were increasing trends of temperature values and decreasing rainfall values in the state. But their projected future values witnessed an increasing trend. The increasing trends in temperature values may lead to a situation were crops will be smothered by excessive heat thereby reducing food production in the state. The study therefore recommends that meteorological station units should be established in the rural farming households in the state where accessibility is extremely difficult. This will make available meteorological data (information to the reach of the poor rural farming household for the attainment of food production.

  20. Synthesis and radiochemical stability of /sup 14/C-Cefotaxime

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, M.D.; Hitzel, V.

    1984-01-01

    /sup 14/C-Cefotaxime (/sup 14/C-HR 756) has been synthesised with the radiolabel in the sidechain aminothiazole ring by a multistep sequence starting from /sup 14/C-thiourea. A high specific activity batch (10400 ..mu..Ci g/sup -1/), and a low specific activity batch (57.1 ..mu..Ci g/sup -1/) suitable for intravenous human use were prepared: Their purity, and solid-state and aqueous solution stability, are described.

  1. Appearance of circulating and tissue /sup 14/C-lipids after oral /sup 14/C-tripalmitate administration in the late pregnant rat

    Energy Technology Data Exchange (ETDEWEB)

    Argiles, J.; Herrera, E.

    1989-02-01

    Studies were performed to determine whether and/or how dietary lipids participate in maternal hypertriglyceridemia during late gestation in the rat. After oral administration of glycerol-tri(1-14C)-palmitate, total radioactivity in plasma increased more rapidly in 20-day pregnant rats than in either 19-day pregnant rats or virgin controls. At the peak of plasma radioactivity, four hours after the tracer was administered, most of the plasma label corresponded to 14C-lipids in triglyceride-rich lipoproteins (d less than 1.006), and when expressed per micromol of triglyceride, values were higher in pregnant than in virgin rats. The difference was less after 24 hours, although at this time the level of 14C-lipids in d less than 1.006 lipoproteins was still higher in 20-day pregnant rats than in virgins. Tissue 14C-lipids, as expressed per gram of fresh weight, were similar in pregnant and virgin rats, but the values in mammary glands were much higher in the former group. Estimated recovery of administered radioactivity four hours after tracer in total white adipose tissue, mammary glands, and plasma lipids was higher in pregnant than in virgin rats. No difference was found between 20-day pregnant and virgin rats either in the label retained in the gastrointestinal tract or in that exhaled as 14C-CO2 during the first four hours following oral administration of 14C-tripalmitate. These findings plus the known maternal hyperphagia, indicate that in the rat at late pregnancy triglyceride intestinal absorption is unchanged or even enhanced and that dietary lipids actively contribute to both maternal hypertriglyceridemia and lipid uptake by the mammary gland.

  2. Synthesis of /sup 14/C-propoxur (o-isopropoxyphenyl N-methylcarbamate-/sup 14/C) insecticide

    Energy Technology Data Exchange (ETDEWEB)

    Hossaini, M.A.; Zareh, Z. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

    1984-08-01

    /sup 14/C-propoxur (Baygonsub(circled R)) is an insecticide with a broad spectrum of activity and a very low order of mammalian toxicity. Radiosynthesis of propoxur was performed by the reaction of acetyl-1-/sup 14/C chloride and sodium azide to produce methyl isocyanate which then reacted with o-isopropoxyphenol at 100 degC. A two-compartment reaction tube with a break seal was utilized. Chromatograhic procedures for isolating the N-methylcarbamates from their reaction mixtures are reported. Acetyl-1-/sup 14/C chloride was prepared from thionyl chloride and sodium acetate-1-/sup 14/C. Grignard reaction between methyl iodide and carbon-14 dioxide yielded acetic acid-/sup 14/C which was neutralized by sodium hydroxide solution to give sodium acetate-1-/sup 14/C. 9 refs.

  3. Effect of anthropogenic activities on atmospheric 14C content and radiocarbon chronologies of the future.

    Science.gov (United States)

    Hajdas, Irka

    2017-04-01

    Radiocarbon (14C) is a naturally produced radioactive isotope of carbon (T1/2=5700 yrs), which is continuously produced in the atmosphere. This occur in a reaction of thermal neutrons, which are secondary particles, products of cosmic rays reactions with the atmosphere, with nitrogen that is commonly present in the atmosphere. Until the mid 19th century the natural concentration showed temporal variability around the mean value (14C / 12C ratio =1.8 x 10-12). However anthropogenic activity created 2 types effects that are changing the 14C concentration of the atmosphere. Industrial revolution triggered adding 14C free (old) carbon that originates from the burning of fossil fuels (Suess effect). This in the late 19th century and early 20th century atmosphere was becoming older. The nuclear tests in the 1950ties caused additional production of radiocarbon atoms (artificial). The effect has been almost double of the natural production and created an excess 14C activity in the atmosphere and in terrestrial carbon bearing materials. The bomb produced 14C has been identified soon after the tests started but the peak (ca. 100% above the normal levels) reached its maximum in 1963 in the northern Hemisphere where most of the tests took place. In the southern Hemisphere the bomb peak reached lower values (ca. 80 % of normal level) and was delayed by ca. 2 years. After the ban on nuclear tests the atmospheric 14C content began to decrease mainly due to the uptake by the ocean but also due to the above mentioned addition old carbon. Continuous monitoring of the atmospheric 14C ratio during the years that followed the nuclear tests, provide basis for environmental studies. Applications range from studies of ocean circulation, CO2 uptake, carbon storage in soils and peat, root turn over time to the medical, forensic and detection of forgeries. However, the so called ' 14C bomb peak' nearly disappeared due to the combined effect of ocean uptake of CO2 and an input to the

  4. Root-uptake of {sup 14}C derived from acetic acid and {sup 14}C transfer to rice edible parts

    Energy Technology Data Exchange (ETDEWEB)

    Ogiyama, Shinichi [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)], E-mail: ogiyama@nirs.go.jp; Suzuki, Hiroyuki [Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi 263-5522 (Japan); Inubushi, Kazuyuki [Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi 271-8510 (Japan); Takeda, Hiroshi; Uchida, Shigeo [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)

    2010-02-15

    Three types of culture experiments using paddy rice (Oryza sativa L.) were performed to examine root-uptake of {sup 14}C in the form of acetic acid: double pot experiment (hydroponics), wet culture experiment (submerged sand medium), and chamber experiment (hydroponics and submerged sand medium). The {sup 14}C radioactivity in the plant, mediums, and atmospheric carbon dioxide ({sup 14}CO{sub 2}) in the chamber were determined, and the distribution of {sup 14}C in the plant was visualized using autoradiography. In the double pot experiment, the shoot of the plant and the lower root which was soaked in the culture solution had {sup 14}C radioactivity, but the upper root which did not have contact with the solution had none. There were also {sup 14}C radioactivity in the grains and roots in the wet culture experiment. Results of the chamber experiment showed that {sup 14}CO{sub 2} gas was released from the culture solution in both types of cultures. Results indicated that the {sup 14}C-acetic acid absorbed by rice plant through its root would be very small. Most of the {sup 14}C-acetic acid was transformed into gaseous forms either in the culture solution or rhizosphere. A relatively longer time would be needed to assimilate {sup 14}C derived from acetic acid to grain parts after it was once absorbed by the shoot through the root. Availability of {sup 14}C for the plant in sand culture was considered to be decreased compared with that for the plant in the hydroponics experiment. It was suggested that rice plant absorbed and assimilated {sup 14}C through the plant roots not because of uptake of {sup 14}C-acetic acid but because of uptake of {sup 14}C in gaseous forms such as {sup 14}CO{sub 2}.

  5. Irradiation Scheme Design of 14C Production on CARR

    Institute of Scientific and Technical Information of China (English)

    SUN; Zheng; LIU; Xing-min; XU; Zhi-long; DING; Li

    2012-01-01

    <正>14C is a radioisotope of carbon. It is widely used in pharmacy, medical treatment, agriculture, reconnoiter and archaeology. China Advanced Research Reactor (CARR) is a research reactor of high capability, the applications of which includes the radio nuclides production. Therefore, the technical scheme on 14C irradiation in CARR should be prepared elaborately.

  6. On the 14C(alpha,gamma) reaction rate

    CERN Document Server

    Johnson, E D; Mitchell, J; Miller, L; Kemper, K W

    2009-01-01

    The 14C(alpha,gamma) reaction rate at temperatures below 0.3 GK depends on the properties of two near threshold resonances in 18O, the 1- at 6.198 MeV and the 3- at 6.404 MeV. The alpha+14C Asymptotic Normalization Coefficients (ANCs) for these resonances were determined using the alpha-transfer reactions 14C(7Li,t) and 14C(6Li,d) at sub-Coulomb energies. The 14C(alpha,gamma) reaction rate at low temperatures has been evaluated. Implications of the new reaction rate on the evolution of accreting helium white dwarfs and on the nucleosynthesis of low mass stars during the asymptotic giant branch (AGB) phase are discussed.

  7. Anthropogenic nitrogen input traced by means of {delta} {sup 15}N values in macroalgae: Results from in-situ incubation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, Barbara [Baltic Sea Research Institute, Seestr. 15, 18119 Rostock (Germany)]. E-mail: barbara.deutsch@io-warnemuende.de; Voss, Maren [Baltic Sea Research Institute, Seestr. 15, 18119 Rostock (Germany)

    2006-08-01

    The macroalgae species Fucus vesiculosus (Phaeophyta), Polysiphonia sp., and Ceramium rubrum (Rhodophyta) originally grown at an unpolluted brackish site of the southern Baltic Sea were incubated for 10 and 14 days at 12 stations along a salinity gradient in a highly polluted estuary. We have expected an adaptation of the initially low {delta} {sup 15}N values to the higher ones within the incubation period. In addition to the macroalgae the {delta} {sup 15}N values of NO{sub 3} {sup -} were measured to evaluate fractionation processes of the source nitrate. Inside the estuary, {delta} {sup 15}N-NO{sub 3} {sup -} values were 6.2-9.7 per mille , indicating anthropogenic nitrogen sources. The red macroalgae adequately reflected the nitrate isotope values in the surrounding waters, whereas for F. vesiculosus the results were not that clear. The reasons were assumed to be higher initial {delta} {sup 15}N values of F. vesiculosus and presumably a too slow nitrogen uptake and growth rate. The method of macroalgae incubations seems suitable as a simple monitoring to study the influence of anthropogenic nitrogen loading in an estuarine environment.

  8. Synthesis of {delta}-aminolevulic acid. Application to the introduction of carbon-14 and of tritium; Syntheses de l'acide {delta} aminolevulique. Application a l'introduction de carbone 14 et de tritium

    Energy Technology Data Exchange (ETDEWEB)

    Loheac, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    Several new syntheses of {delta} aminolevulic acid ({delta} A.L.A.) have been studied. {sup 14}C-4 {delta} - aminolevulic acid has been obtained from {sup 14}C allylacetic carboxylic acid with a yield of 30 per cent with respect to barium carbonate and with a specific activity of 32 mCi/mM. The {sup 14}C-1 or {sup 14}C-2 {delta}-A.L.A. has been prepared from the {sup 14}C-1 or {sup 14}C-2 acetate with a yield of 55 per cent with respect to the acetate. Finally the tritiated {delta}-A.L.A. has been obtained for the first time by tritiation of ethyl phthalimidodehydrolevulate. (author) [French] Plusieurs syntheses nouvelles de l'acide {delta}-aminolevulique ont ete etudiees. L'acide {delta}-aminolevulique {sup 14}C-4 a ete obtenu a partir d'acide allylacetique carboxylique {sup 14}C, avec un rendement global de 30 pour cent par rapport au carbonate de baryum a une activite specifique de 32 mCi/M. Le {delta}-A.A.L. {sup 14}C-1 ou {sup 14}C-2 a ete obtenu a partir d'acetate {sup 14}C-1 ou {sup 14}C-2 avec un rendement de 55 pour cent par rapport a l'acetate. Enfin le {delta}-A.A.L. tritie a ete obtenu pour la premiere fois par tritiation du phtalimidodehydrolevulate d'ethyle. (auteur)

  9. Delta13C values of grasses as a novel indicator of pollution by fossil-fuel-derived greenhouse gas CO2 in urban areas.

    Science.gov (United States)

    Lichtfouse, Eric; Lichtfouse, Michel; Jaffrézic, Anne

    2003-01-01

    A novel fossil fuel pollution indicator based on the 13C/12C isotopic composition of plants has been designed. This bioindicator is a promising tool for future mapping of the sequestration of fossil fuel CO2 into urban vegetation. Theoretically, plants growing in fossil-fuel-CO2-contaminated areas, such as major cities, industrial centers, and highway borders, should assimilate a mixture of global atmospheric CO2 of delta13C value of -8.02 per thousand and of fossil fuel CO2 of average delta13C value of -27.28 per thousand. This isotopic difference should, thus, be recorded in plant carbon. Indeed, this study reveals that grasses growing near a major highway in Paris, France, have strikingly depleted delta13C values, averaging at -35.08 per thousand, versus rural grasses that show an average delta13C value of -30.59 per thousand. A simple mixing model was used to calculate the contributions of fossil-fuel-derived CO2 to the plant tissue. Calculation based on contaminated and noncontaminated isotopic end members shows that urban grasses assimilate up to 29.1% of fossil-fuel-CO2-derived carbon in their tissues. The 13C isotopic composition of grasses thus represents a promising new tool for the study of the impact of fossil fuel CO2 in major cities.

  10. TMEM14C is required for erythroid mitochondrial heme metabolism.

    Science.gov (United States)

    Yien, Yvette Y; Robledo, Raymond F; Schultz, Iman J; Takahashi-Makise, Naoko; Gwynn, Babette; Bauer, Daniel E; Dass, Abhishek; Yi, Gloria; Li, Liangtao; Hildick-Smith, Gordon J; Cooney, Jeffrey D; Pierce, Eric L; Mohler, Kyla; Dailey, Tamara A; Miyata, Non; Kingsley, Paul D; Garone, Caterina; Hattangadi, Shilpa M; Huang, Hui; Chen, Wen; Keenan, Ellen M; Shah, Dhvanit I; Schlaeger, Thorsten M; DiMauro, Salvatore; Orkin, Stuart H; Cantor, Alan B; Palis, James; Koehler, Carla M; Lodish, Harvey F; Kaplan, Jerry; Ward, Diane M; Dailey, Harry A; Phillips, John D; Peters, Luanne L; Paw, Barry H

    2014-10-01

    The transport and intracellular trafficking of heme biosynthesis intermediates are crucial for hemoglobin production, which is a critical process in developing red cells. Here, we profiled gene expression in terminally differentiating murine fetal liver-derived erythroid cells to identify regulators of heme metabolism. We determined that TMEM14C, an inner mitochondrial membrane protein that is enriched in vertebrate hematopoietic tissues, is essential for erythropoiesis and heme synthesis in vivo and in cultured erythroid cells. In mice, TMEM14C deficiency resulted in porphyrin accumulation in the fetal liver, erythroid maturation arrest, and embryonic lethality due to profound anemia. Protoporphyrin IX synthesis in TMEM14C-deficient erythroid cells was blocked, leading to an accumulation of porphyrin precursors. The heme synthesis defect in TMEM14C-deficient cells was ameliorated with a protoporphyrin IX analog, indicating that TMEM14C primarily functions in the terminal steps of the heme synthesis pathway. Together, our data demonstrate that TMEM14C facilitates the import of protoporphyrinogen IX into the mitochondrial matrix for heme synthesis and subsequent hemoglobin production. Furthermore, the identification of TMEM14C as a protoporphyrinogen IX importer provides a genetic tool for further exploring erythropoiesis and congenital anemias.

  11. TMEM14C is required for erythroid mitochondrial heme metabolism

    Science.gov (United States)

    Yien, Yvette Y.; Robledo, Raymond F.; Schultz, Iman J.; Takahashi-Makise, Naoko; Gwynn, Babette; Bauer, Daniel E.; Dass, Abhishek; Yi, Gloria; Li, Liangtao; Hildick-Smith, Gordon J.; Cooney, Jeffrey D.; Pierce, Eric L.; Mohler, Kyla; Dailey, Tamara A.; Miyata, Non; Kingsley, Paul D.; Garone, Caterina; Hattangadi, Shilpa M.; Huang, Hui; Chen, Wen; Keenan, Ellen M.; Shah, Dhvanit I.; Schlaeger, Thorsten M.; DiMauro, Salvatore; Orkin, Stuart H.; Cantor, Alan B.; Palis, James; Koehler, Carla M.; Lodish, Harvey F.; Kaplan, Jerry; Ward, Diane M.; Dailey, Harry A.; Phillips, John D.; Peters, Luanne L.; Paw, Barry H.

    2014-01-01

    The transport and intracellular trafficking of heme biosynthesis intermediates are crucial for hemoglobin production, which is a critical process in developing red cells. Here, we profiled gene expression in terminally differentiating murine fetal liver-derived erythroid cells to identify regulators of heme metabolism. We determined that TMEM14C, an inner mitochondrial membrane protein that is enriched in vertebrate hematopoietic tissues, is essential for erythropoiesis and heme synthesis in vivo and in cultured erythroid cells. In mice, TMEM14C deficiency resulted in porphyrin accumulation in the fetal liver, erythroid maturation arrest, and embryonic lethality due to profound anemia. Protoporphyrin IX synthesis in TMEM14C-deficient erythroid cells was blocked, leading to an accumulation of porphyrin precursors. The heme synthesis defect in TMEM14C-deficient cells was ameliorated with a protoporphyrin IX analog, indicating that TMEM14C primarily functions in the terminal steps of the heme synthesis pathway. Together, our data demonstrate that TMEM14C facilitates the import of protoporphyrinogen IX into the mitochondrial matrix for heme synthesis and subsequent hemoglobin production. Furthermore, the identification of TMEM14C as a protoporphyrinogen IX importer provides a genetic tool for further exploring erythropoiesis and congenital anemias. PMID:25157825

  12. Bound 14C-metsulfuron-methyl residue in soils

    Institute of Scientific and Technical Information of China (English)

    YE Qing-fu; DING Wei; WANG Hai-yan; HAN Ai-liang; SUN Jin-he

    2005-01-01

    Bound residue(BR) of 14 C-metsulfuron-methyl (14 C-BR) in seven kinds of soil was significantly negative-related to soil pH and positive-related to the clay content during the initial 20 d of incubation, but only was significantly negative-related to soil pH after 30 d incubation. Again, the soil pH was found to be the dominant factor affecting BR formation from 14 C-metsulfuron-methyl among the basic properties(soil pH, clay, OM and CEC etc.) of soil. The maximum content of 14C-BR in the 7 soils accounted for 19.3% -52.6% of applied amount. In addition, the composition of the 14 C-BR in fluvio marine yellow loamy(S7 ) at the 90 d of incubation was identified using the coupling technique of LC-MS and isotope tracing method. The results showed that the 14 C-[2-amino-4-hydroxyl-6-methyl-1, 3, 5]-triazine, 14 C-[2-amino-4-methoxy-6-methyl-1, 3, 5]-triazine and 14 C-metsulfuron-methyl parent compound constituted the main components of the BR derived from 14 C-metsulfuron-methyl in the S7. The relative percentage of the three compounds accounted for 41.4 %, 35.8 % and 19.3 % of total recovery radioactivity, respectively. The results also indicated that a non- radioactive component, 2-methylformate-benzenesulfonyl-isocyanate, one of the degraded products of metsulfuron-methyl in soil, was also found to be one of the components of the BR. The parent compound in BR can well explain the phytotoxic effect on substitution crops caused by the BR derived from metsulfuron-methyl in soil.

  13. Understanding the Value of Satellite Altimetry for Monitoring Water Level Dynamics of Large Rivers in Bangladesh Delta

    Science.gov (United States)

    Hossain, F.; Akbor, S.; Sustainability, Satellites, Water; Environment (Saswe) Research Group

    2010-12-01

    Although transboundary river flow accounts for more than 40% of global surface flow across 145 nations (many of them water-stressed and conflict-prone), most of this flow is difficult to monitor in developing nations at operational timescales. For Bangladesh, this situation is particularly acute because it comprises only 7% of the entire Ganges-Brahmaputra-Meghna basin and is located at the downstream end of the basin. Thus more than 90% of the water is generated in upstream nations and yet this information is hard to obtain in Bangladesh due to lack of transboundary instrumentation or international treaties. This work therefore investigates the value of satellite radar altimetry in detecting the water level changes for large rivers in the Bangladesh Delta. It is founded on the hypothesis that a satellite altimeter can detect water level to the same accuracy for both inside and outside of Bangladesh. First, the river hydraulic model called HEC-RAS (Hydrologic Engineering Center, River Analysis System) is set up and calibrated over Bangladesh using a comprehensive database on in-situ river bathymetry and observed water level records. Next, the calibrated HEC-RAS model is provided boundary flow conditions upstream and downstream of the model domain. At the upstream end where the Ganges, Brahmaputra and Meghan enter Bangladesh, high resolution flow data modeled from a well calibrated hydrologic model called MIKE BASIN is provided as input. The observed tidal flow records of the Meghna estuary near the Bay of Bengal are used as the downstream boundary conditions. HEC-RAS is then used to simulate daily water level data for the period of 2003-2005 for major rivers of Bangladesh. These water level simulations are directly compared with altimeter estimates of water level from the ENVISAT mission. Accuracy of ENVISAT data is characterized as a function of season, flow regime and river type. The important question that this study aims to answer is, “To what extent can

  14. Synthesis of barbituric acid-2 {sup 14}C and alloxan-2 {sup 14}C from urea {sup 14}C; Synthese de l'acide barbiturique {sup 14}C-2 et de l'alloxane {sup 14}C-2 a partir d'uree {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, M.; Pichat, L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Pochon, F. [Faculte des Sciences, Lab. de Chimie Biologique, 75 - Paris (France)

    1961-07-01

    Urea {sup 14}C and ethyl malonate have given rise to barbituric acid with a 93 per cent yield. The latter has been converted into its benzylidene derivative with a 81 per cent yield. Oxidation of the latter, by chromic oxide in anhydrous acetic acid provided alloxan-2 {sup 14}C with 60 per cent yield. Purity of the compounds has been checked by paper chromatography. (author) [French] L'uree {sup 14}C condensee sur le malonate d'ethyle a conduit a l'acide barbiturique {sup 14}C-2 avec un rendement de 93 pour cent. Ce dernier a ete transforme en acide benzylidenebarbiturique avec un rendement de 81 pour cent. L'oxydation de ce compose par l'acide chromique en milieu acetique a fourni l'alloxane monohydrate {sup 14}C-2 avec un rendement de 70 pour cent. La purete des produits a ete controlee par chromatographie sur papier. (auteur)

  15. Release of [sup 14]C from the gap and grain-boundary regions of used CANDU fuels to aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Stroes-Gascoyne, S.; Tait, J.C.; Porth, R.J.; McConnell, J.L.; Lincoln, W.J. (Whiteshell Lab., Pinawa, Manitoba (Canada). AECL Research)

    1994-01-01

    This study was undertaken as part of the Canadian Nuclear Fuel Waste Management Program (CNFWMP), to measure [sup 14]C inventories of used CANDU fuel. Other objectives were to measure the fraction of the total [sup 14]C inventory that would be instantly released to solution from used CANDU fuels upon sheath failure and to determine if the assumptions made in safety assessment calculations of used fuel waste disposal regarding instant release of [sup 14]C were correct. Results showed that the measured [sup 14]C inventories were a factor of 11.5 [+-] 3.9 lower than the estimated [sup 14]C inventory values used in safety assessment calculations. Measured instant release values for [sup 14]C ranged from 0.06 to 5.04% (of total [sup 14]C inventories) with an average of 2.7 [+-] 1.6%, indicating that instant release fractions for [sup 14]C used in safety assessment calculations (1.2--25%) were overestimated.

  16. Forensic applications of {sup 14}C bomb-pulse dating

    Energy Technology Data Exchange (ETDEWEB)

    Zoppi, U. E-mail: ugo@ansto.gov.au; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A

    2004-08-01

    After a brief review of the basics of {sup 14}C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the {sup 14}C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of {sup 14}C concentrations in milligram samples taken from seized drugs are presented. {sup 14}C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

  17. ( sup 14 C)Virginiamycin residues in eggs

    Energy Technology Data Exchange (ETDEWEB)

    Corpet, D.E.; Baradat, M.; Bories, G.F. (Xenobiotiques Lab., Toulouse (France))

    Laying hens were fed ab libitum a diet supplemented at 40, 10, and 0 mg/kg with ({sup 14}C)virginiamycin, to determine whether or not virginamycin or its metabolites were transferred to the eggs. About 0.05% of the ingested {sup 14}C dose was recovered in the eggs. Radiolabeled residues expressed in terms of virginiamycin equivalents were found to be 5.1 ng/g in the albumen and 31.8 ng/g in the yolk from hens fed a 10 mg/kg diet. No antibiotic activity could be detected in the eggs. Tentative identifications showed that in the albumen about 17% of the {sup 14}C behaved chromatographically like virginiamycin and 18% was associated to the ovalbumin. In the yolk 31% of the {sup 14}C was associated to proteins, 58% to fatty acids, and 4% to unsaponifiable matter.

  18. Effect of HF leaching on 14C dates of pottery

    Science.gov (United States)

    Goslar, Tomasz; Kozłowski, Janusz; Szmyt, Marzena; Czernik, Justyna

    2013-01-01

    This paper presents the experiments with 14C dating of two potsherds, which contained carbon dispersed rather homogeneously in their clay fabric. After AAA treatment, the potsherds still appeared to be contaminated with young carbon, presumably connected with humic acids. To make removal of humic acids more effective, we treated the sherds with HF acid of different concentration. The 14C results obtained demonstrate that HF treatment indeed helps to remove humic contaminants, but it also mobilizes carbon bound to raw clay, which may make 14C dates too old. We conclude therefore, that using a simple combination of HF and AAA treatment seems insufficient in reliable 14C dating of carbon homogeneously dispersed in the volume of potsherds.

  19. Tracing terrestrial carbon: a novel application of ∆14C in a humic lake

    Science.gov (United States)

    Keaveney, Evelyn; Reimer, Paula J.; Foy, Robert H.

    2016-04-01

    Lakes play an important yet underrated role in global carbon cycles. Terrestrial carbon (C) is buried and/or remineralised in significant quantities, and lake function may also be affected by catchment inputs with potential feedbacks for regional and global C cycling. Changing deposition chemistry, land use and climate induced impacts on hydrology will affect soil biogeochemistry, terrestrial C export, and hence lake ecology. Autochthonous production in lakes is based on dissolved inorganic C (DIC). DIC in alkaline lakes is partially derived from weathering of carbonaceous bedrock, a proportion of which is 14C-free. The low 14C activity yields an artificial age offset leading samples to appear hundreds to thousands of years older than their actual age. Dissolved organic carbon (DOC) and particulate organic carbon (POC) can contain terrestrial inputs. The terrestrial inputs can be labile or detrital and their age depends to a first order on their depth in catchment soil/peat stocks. We present a pilot study that uses the radiocarbon (∆14C) method to determine the source of carbon buried in the surface sediment of Lower Lough Erne, a humic, alkaline lake in northwest Ireland. ∆14C, δ13C and δ15N values were measured from phytoplankton and other biota, dissolved inorganic, dissolved organic and particulate organic carbon. A novel radiocarbon method, Stepped Combustion1 was used to estimate the degree of the burial of terrestrial carbon in surface sediment, collected in 2011. The ∆14C values of the low temperature fractions were comparable to algal ∆14C, while the high temperature fractions were 14C-depleted (older than bulk sediment). The ∆14C end-member model indicated that ~64% of carbon in surface sediment was derived from detrital terrestrial carbon. The same proportion of detrital/labile carbon was found in surface sediment of Upper Lough Erne in 2014, despite the differences in lake type and collection date. The use of ∆14C in conjunction with

  20. New measurement of exotic decay of {sup 225}Ac by {sup 14}C emission

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmetti, A.; Bonetti, R. [Istituto di Fisica Generale Applicata dell' Universita di Milano (Italy); Istituto Nazionale di Fisica Nucleare, Milan (Italy); Ardisson, G.; Barci, V. [Lab. de Radiochimie, Universite de Nice Sophia-Antipolis, Nice (France); Giles, T.; Ravn, H.L. [CERN, EP Division, Geneva (Switzerland); Hussonnois, M.; Le Du, J.F.; Le Naour, C.; Trubert, D. [Institut de Physique Nucleaire, Orsay (France); Mikheev, V.L.; Tretyakova, S.P. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Pasinetti, A.L. [Istituto di Fisica Generale Applicata dell' Universita di Milano (Italy)

    2001-12-01

    The branching ratio of {sup 225}Ac decay by emission of {sup 14}C was remeasured under improved experimental conditions by using a radioactive source produced at the ISOLDE mass-separator at CERN and a nuclear track detector technique. The result, B={lambda}{sup 14C}/{lambda}{sub {alpha}}=(4.5{+-}1.4)10{sup -12}, is consistent with the anomalously high value obtained in the 1993 experiment, thus confirming the importance of nuclear-structure effects in this exotic decay. (orig.)

  1. Pollen-based biomes for Beringia 18,000, 6000 and 0 14C yr BP

    Science.gov (United States)

    Edwards, M.E.; Anderson, P.M.; Brubaker, L.B.; Ager, T.A.; Andreev, A.A.; Bigelow, N.H.; Cwynar, L.C.; Eisner, Wendy R.; Harrison, S.P.; Hu, F.-S.; Jolly, D.; Lozhkin, A.V.; MacDonald, G.M.; Mock, C.J.; Ritchie, J.C.; Sher, A.V.; Spear, R.W.; Williams, J.W.; Yu, G.

    2000-01-01

    The objective biomization method developed by Prentice et al. (1996) for Europe was extended using modern pollen samples from Beringia and then applied to fossil pollen data to reconstruct palaeovegetation patterns at 6000 and 18,000 14C yr BP. The predicted modern distribution of tundra, taiga and cool conifer forests in Alaska and north-western Canada generally corresponds well to actual vegetation patterns, although sites in regions characterized today by a mosaic of forest and tundra vegetation tend to be preferentially assigned to tundra. Siberian larch forests are delimited less well, probably due to the extreme under-representation of Larix in pollen spectra. The biome distribution across Beringia at 6000 14C yr BP was broadly similar to today, with little change in the northern forest limit, except for a possible northward-advance in the Mackenzie delta region. The western forest limit in Alaska was probably east of its modern position. At 18,000 14C yr BP the whole of Beringia was covered by tundra. However, the importance of the various plant functional types varied from site to site, supporting the idea that the vegetation cover was a mosaic of different tundra types.

  2. Comment on ``Interpretation of the fine structure in the 14C radioactive decay of 223'

    Science.gov (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Ardisson, G.

    1991-12-01

    Priority of our interpretation of the fine structure in the 14C radioactive decay of 223Ra is asserted. It seems that the deformation parameter values, used in the framework of ARM to interpret properties of both 223Ra ground and excited states, partly allow for the qualitative interpretation of the experimental hindrance factors to the 209Pb states.

  3. 14C dating of bone using (gamma) Carboxyglutamic Acid and Carboxyglycine (Aminomalonate)

    Energy Technology Data Exchange (ETDEWEB)

    Southon, J R; Burky, R T; Kirner, D L; Taylor, R E; Hare, P E

    1999-04-27

    Radiocarbon determinations have been obtained on {gamma}-carboxyglutamic acid [Gla] and {alpha}-carboxyglycine (aminomalonate) [Am] as well as acid- and base-hydrolyzed total amino acids isolated from a series of fossil bones. As far as they are aware, Am has not been reported previously in fossil bone and neither Gla nor Am {sup 14}C values have been measured previously. Interest in Gla, an amino acid found in the non-collagen proteins osteocalcin and matrix Gla-protein (MGP), proceeds from the suggestion that it may be preferentially retained and more resistant to diagenetic contamination affecting {sup 14}C values in bones exhibiting low and trace amounts of collagen. The data do not support these suggestions. The suite of bones examined showed a general tendency for total amino acid and Gla concentrations to decrease in concert. Even for bones retaining significant amounts of collagen, Gla (and Am extracts) can yield {sup 14}C values discordant with their expected age and with {sup 14}C values obtained on total amino-acid fractions isolated from the same bone sample.

  4. Progress report on a novel in situ14C extraction scheme at the University of Cologne

    Science.gov (United States)

    Fülöp, R.-H.; Wacker, L.; Dunai, T. J.

    2015-10-01

    We present initial results of in situ14C system blank and calibration sample measurements obtained using the in situ14C extraction scheme developed at the University of Cologne. The 14C extraction scheme specifically exploits the phase transformation of quartz to cristobalite in order to quantitatively extract the carbon as CO2 and follows a scheme that is different to that of existing extraction systems. Features are offline furnace extraction, single pass catalytic oxidation using mixed copper (I,II) oxide as catalyst, the use of UHV-compatible components and of vacuum annealed copper tubing. The design allows a relatively rapid sample throughput - two samples per day as opposed to the current 2 days per sample that can be done on other lines - and can accommodate samples ranging between 0.5 and 4 g of clean quartz. Following extraction and cleaning, the CO2 gas is measured using the gas ion source of the MICADAS AMS facility at ETH Zurich. The extraction system yields low systems blanks (10 +16/-10 × 103 atoms 14C, ±1 σ) and the initial results indicate that further improvements are achievable. Measurements of the CRONUS-A standard sample show a good reproducibility and results are consistent with published values. We also present the first in situ14C results for the CRONUS-R standard material.

  5. {sup 14}C in human diet in three Spanish locations; {sup 14}C en dieta humana en tres localizaciones espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Martinez, I.; Santos Arevalo, F. J.; Manjon, G.; Garcia-Tenorio, R.

    2011-07-01

    {sup 14}C reach humans via the diet. In this study we present the results of diet samples from three locations type Spanish, Seville, Caceres and Tenerife. These diets are collected quarterly and historical dates back to early 2008.

  6. Synthesis of (21- sup 14 C)-fusarin C by enzymic demethylation and remethylation with ( sup 14 C)-diazomethane

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S.-J.; Li, M.H. (Chinese Academy of Medical Sciences, Beijing (China). Dept. of Chinese Etiology and Carcinogenesis); Jeffrey, A.M. (Columbia Univ., New York, NY (USA))

    1989-08-01

    Fusarin C, a potent mutagen isolated from Fusarium moniliforme culture extracts, has been prepared radiolabeled in two steps by enzymic hydrolysis of the 21-methyl ester group, using phenobarbital induced microsomal preparations, followed by remethylation using ({sup 14}F)-diazomethane. Yields, based upon fusarin C, were essentially quantitative and approximately 10% of the ({sup 14}C)-methyl-nitrosourea, converted to diazomethane, reacted to yield ({sup 14}C)-fusarin C. (author).

  7. Possibilities of climate reconstruction in the Holocene using {delta}{sup 13}C and {delta}{sup 2}H values from annual tree rings on the basis of climate chamber experiments and studies on present-day organisms; Moeglichkeiten der Klimarekonstruktion im Holozaen mit {delta}{sup 13}C- und {delta}{sup 2}H-Werten von Baum-Jahrringen auf der Basis von Klimakammerversuchen und Rezentstudien

    Energy Technology Data Exchange (ETDEWEB)

    Mayr, C.

    2002-07-01

    This study deals with the climatic information content of {sup 2}H and {sup 13}C levels in annual tree rings and plant material. The influence of variations in air temperature, relative humidity and water availability on stable isotope ratios in three different C{sub 3} plant species (Brassica oleracea, Eucalyptus globulus, Vicia faba) was studied in climate chamber experiments. Furthermore, calibration studies using {delta}{sup 13}C and {delta}{sup 2}H time series from Southern German spruce (Picea abies) from two stands (Schussbach, Klosterreichenbach) were performed. Correlations with meteorological data from a nearby meteorological station prove stable isotope ratios to be dependent on weather conditions in the summer months (June through August). Using the {delta}{sup 13}C ''response surfaces'' obtained from these experiments as well as correlations from long gridbox precipitation series it was shown that for the climate mode under study the {delta}{sup 13}C values largely reflect water availability to trees, which is greatly influenced by summer precipitation, especially at the more arid of the two sites. The results of the climate chamber experiments also suggest that the spruce {delta}{sup 2}H values largely reflect the isotope variation in soil water and hence the {delta}{sup 2}H fluctuations in summer precipitation. The study closes with a discussion of methodological approaches to creating long isotope series from annual tree rings of subfossil oak trees.

  8. Intra-annual variability of anatomical structure and delta(13)C values within tree rings of spruce and pine in alpine, temperate and boreal Europe.

    Science.gov (United States)

    Vaganov, Eugene A; Schulze, Ernst-Detlef; Skomarkova, Marina V; Knohl, Alexander; Brand, Willi A; Roscher, Christiane

    2009-10-01

    Tree-ring width, wood density, anatomical structure and (13)C/(12)C ratios expressed as delta(13)C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, delta(13)C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained tree-ring width and wood density over consecutive years, while 29-58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and delta(13)C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The delta(13)C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between delta(13)C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the delta(13)C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its

  9. Measuring the 14C content in liquid scintillators

    Science.gov (United States)

    Enqvist, T.; Barabanov, I. R.; Bezrukov, L. B.; Gangapshev, A. M.; Gavrilyuk, Y. M.; Grishina, V. Yu; Gurentsov, V. I.; Hissa, J.; Joutsenvaara, J.; Kazalov, V. V.; Krokhaleva, S.; Kutuniva, J.; Kuusiniemi, P.; Kuzminov, V. V.; Kurlovich, A. S.; Loo, K.; Lubsandorzhiev, B. K.; Lubsandorzhiev, S.; Morgalyuk, V. P.; Novikova, G. Y.; Pshukov, A. M.; Sinev, V. V.; Słupecki, M.; Trzaska, W. H.; Umerov, Sh I.; Veresnikova, A. V.; Virkajärvi, A.; Yanovich, Y. A.; Zavarzina, V. P.

    2016-05-01

    We are going to perform a series of measurements where the 14C/12 C ratio will be measured from several liquid scintillator samples with a dedicated setup. The setup is designed with the aim of measuring ratios smaller than 10-18. Measurements take place in two underground laboratories: in the Baksan Neutrino Observatory, Russia and in the Pyhäsalmi mine, Finland. In Baksan the measurements started in 2015 and in Pyhäsalmi they start in the beginning of 2015. In order to fully understand the operation of the setup and its background contributions a development of simulation packages has also been started. Low-energy neutrino detection with a liquid scintillator requires that the intrinsic 14C content in the liquid is extremely low. In the Borexino CTF detector at Gran Sasso, Italy the 14C/12C ratio of 2 × 10-18 has been achieved being the lowest 14C concentration ever measured. In principle, the older the oil or gas source that the liquid scintillator is derived of and the deeper it situates, the smaller the 14C/12C ratio is supposed to be. This, however, is not generally the case, and the ratio is probably determined by the U and Th content of the local environment.

  10. Application and detection of (14)c-hd in two mouse models.

    Science.gov (United States)

    Logan, Thomas P; Shutz, Michael; Schulz, Susan M; Railer, Roy; Ricketts, Karen M; Casillas, Robert P

    2002-01-01

    The CD1-haired mouse and the SKH-hairless mouse are two animal models that have been used to evaluate sulfur mustard (HD) exposure and protection in our laboratory. In a recent study we observed that a substance P inhibitor protected the haired mouse ear against an HD solution, but the same drug was not successful in protecting the hairless mouse against HD vapor. This experiment prompted us to compare HD exposures between these models. We determined the (14)C content in the skin after exposures to HD containing (14)C-HD. Rate curves were generated for applications of (1) HD in methylene chloride to the haired mouse ear; (2) HD in methylene chloride to the hairless mouse dorsal skin; and (3) saturated HD vapor to the hairless mouse dorsal skin for 6 min. The curves showed a reduction in (14)C disintegrations per min in animals euthanized 0 to 2 h postexposure. The largest percentage of decrease of (14)C content in skin occurred within 30 min of HD challenge for all exposures. An 8-mm skin-punch biopsy and a 14-mm annular skin section surrounding the region of the 8-mm skin punch were taken from the hairless mouse dorsal skin exposed to HD in methylene chloride. The ratio of the (14)C content in the 8-mm skin punch to that in the surrounding 14-mm annular skin section was 7.3, demonstrating that the HD application spreads beyond the initially biopsied site. A concentration/time value of 6.3 mug/cm(2)/min was determined by counting skin (14)C disintegrations per minute in animals euthanized immediately after exposure to saturated HD vapor. Determinations of the amount of HD showed that similar quantities of HD, 0.4 mg, were detected on each model. These results contribute to a better quantitative understanding of HD application in the haired and hairless mouse models.

  11. (14)C levels in the vicinity of the Fukushima Dai-ichi Nuclear Power Plant prior to the 2011 accident.

    Science.gov (United States)

    Xu, Sheng; Cook, Gordon T; Cresswell, Alan J; Dunbar, Elaine; Freeman, Stewart P H T; Hastie, Helen; Hou, Xiaolin; Jacobsson, Piotr; Naysmith, Philip; Sanderson, David C W; Tripney, Brian G; Yamaguchi, Katsuhiko

    2016-06-01

    A 50-year-old Japanese cedar (Cryptomeria japonica) from Okuma, ∼1 km southwest of the Fukushima Dai-ichi Nuclear Power Plant, was cored and each annual ring was analysed for (14)C. The (14)C specific activity values varied from 330.4 Bq kg(-1) C in the tree ring formed in 1971 to 231.2 Bq kg(-1) C in the 2014 ring. During the periods 1971-1976 and 2011-2014, the (14)C specific activities are indistinguishable from the ambient background values. However, compared with the ambient atmospheric levels, the (14)C specific activities between 1977 and 2010 are significantly elevated, clearly indicating (14)C discharges from the reactors during their normal operations. In addition, the specific activities are positively correlated with the annual electricity generation values. The excess (14)C specific activities were wind direction is east-southeast/southeast with a frequency of ∼30%, in comparison to ∼20% frequency for the direction of the site under study (north-northeast/northeast). This would tend to indicate a similar magnitude of additional effective dose and consequently no significant radiological impact of atmospheric (14)C discharges from the FDNPP during the entire period of normal operations. Additionally, no (14)C pulse in activity can be observed in the year 2011 ring. This might be caused by a limited (14)C release from the damaged reactors during the accident or that the prevailing wind during the short period of release (11th-25th March 2011) was not in the direction of Okuma.

  12. Transformation of Straw 14C in Ultisol and Vertisol

    Institute of Scientific and Technical Information of China (English)

    WANGZHIMING; HUANGDONGMAI; 等

    1998-01-01

    Laboratory incubation was conducted to investigate transformation of straw 14C in Ultisol and Vertisol under aerobic conditiol for 112 d at 30℃,Dried and ground 14C-labeled rice and majze straws sere mixed with the soils at the rate of 2.5g kg-1 ,Decomposition of the straw C and native soil C both revealed two stages,being faster during the intial day,and slower thereafter,About 37.33%-48.80% of the straw C and 4.22%-6.83% of the native soil C decomposed by the end of the incubation.The kinds of the straws only slightly influenced the rates of their decomposition in soils,however,some retardation was found in Ultisol at the intial decomposition stage due to its lowr pH.Positvie priming effects were observed in the soils spplied with straw ,and the rate of priming effect ranged from 7.23% to 13.80%.Net losses of native soil C were found under such incubation conditions ,except Ultisol with rice straw.Soil biomass of and 14C decreased gradually with incubation time,and seemed to be consistent with the decomposition patterns of straw C and native soil C.The ratio of biomass 12C to biomass 14C ranged from 1.35 to 3.37 .soil biomass C occupied 1.17%-2.32% of the total soil organic C,and the proportion of biomass 14C to the residual 14C varied from 7.3% to 14.3%.

  13. Microdose 14C urea breath test for the diagnosis of Helicobacter pylori: a survey in Iranian population

    Directory of Open Access Journals (Sweden)

    Reza Dowlatabadi Bazaz

    2005-01-01

    Full Text Available The carbon -14 urea breath test (UBTis a non-invasive and simple method for the diagnosis of Helicobacter pylori infection. Attempts have been made to use lower doses of 14C-urea in the UBT in order to reduce the radiation risk of the test. The aim of this study was to assess the accuracy of a microdose (1 µCi [37 KBq] 14C-UBT in Iranian population for validation of its diagnostic accuracy against gold standard methods. Eighty and two patients were subjected to upper gastrointestinal endoscopy as well as 14C-UBT in one week. Rapid urease test and histological examinations were used as gold standard. Breath samples were collected 10, 20 and 30 minute after ingestion of 1 µCi of 14C- urea solution and their activities were measured using a scintillation counter and expressed as counts per minute (cpm and disintegration per minute (dpm. Good agreement was observed between the 14C-UBT and gold standard for samples which were collected 20 minutes after 14C-urea administration. The 14CUBT showed 100% sensitivity, 95% specificity, 95.45% positive predictive value, 100% negative predictive value and 97.50% accuracy. The results of this study showed good concordance between the 14C-UBT and invasive methods.

  14. A comparison of U/Th and rapid-screen 14C dates from Line Island fossil corals

    Science.gov (United States)

    Grothe, Pamela R.; Cobb, Kim M.; Bush, Shari L.; Cheng, Hai; Santos, Guaciara M.; Southon, John R.; Lawrence Edwards, R.; Deocampo, Daniel M.; Sayani, Hussein R.

    2016-03-01

    Time-consuming and expensive radiometric dating techniques limit the number of dates available to construct absolute chronologies for high-resolution paleoclimate reconstructions. A recently developed rapid-screen 14C dating technique reduces sample preparation time and per sample costs by 90%, but its accuracy has not yet been tested on shallow-water corals. In this study, we test the rapid-screen 14C dating technique on shallow-water corals by comparing 44 rapid-screen 14C dates to both high-precision 14C dates and U/Th dates from mid- to late-Holocene fossil corals collected from the central tropical Pacific (2-4°N, 157-160°W). Our results show that 42 rapid-screen 14C and U/Th dates agree within uncertainties, confirming closed-system behavior and ensuring chronological accuracy. However, two samples that grew ˜6500 years ago have calibrated 14C ages ˜1000 years younger than the corresponding U/Th ages, consistent with diagenetic alteration as indicated by the presence of 15-23% calcite. Mass balance calculations confirm that the observed dating discrepancies are consistent with 14C addition and U removal, both of which occur during diagenetic calcite recrystallization. Under the assumption that aragonite-to-calcite replacement is linear through time, we estimate the samples' true ages using the measured 14C and U/Th dates and percent calcite values. Results illustrate that the rapid-screen 14C dates of Holocene-aged fossil corals are accurate for samples with less than 2% calcite. Application of this rapid-screen 14C method to the fossil coral rubble fields from Kiritimati Island reveal significant chronological clustering of fossil coral across the landscape, with older ages farther from the water's edge.

  15. Causes of an AD 774-775 14C increase

    CERN Document Server

    Melott, Adrian L; 10.1038/nature11695

    2012-01-01

    Atmospheric 14C production is a potential window into the energy of solar proton and other cosmic ray events. It was previously concluded that results from AD 774-775 are orders of magnitude greater than known solar events. We find that the coronal mass ejection energy based on 14C production is much smaller than claimed, but still substantially larger than the maximum historical Carrington Event of 1859. Such an event would cause great damage to modern technology, and in view of recent confirmation of superflares on solar-type stars, this issue merits attention.

  16. AMS of {sup 14}C at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Suter, M.; Huber, R.; Jacob, S. [ETHZ, Zurich (Switzerland); Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    At the ETH/PSI AMS facility {sup 14}C test measurements have been performed at low terminal voltages of 0.5 and 1 MV in order to study the feasibility of AMS with very small accelerators. These experiments have demonstrated that interfering molecules ({sup 13}CH and {sup 12}CH{sub 2}) in charge states 1{sup +} and 2{sup +} can be destroyed in an adequate Ar gas stripper. These new results imply the feasibility of a new generation of very small accelerator systems for {sup 14}C. (author) 1 fig., 3 refs.

  17. Employee Training Needs and Perceived Value of Training in the Pearl River Delta of China: A Human Capital Development Approach

    Science.gov (United States)

    Au, Alan Kai Ming; Altman, Yochanan; Roussel, Josse

    2008-01-01

    Purpose: This paper aims to explore Hong Kong firms' training needs in the Pearl River Delta, a booming region in the fast growing People Republic of China economy, by resorting to a human capital approach. Also, to identify the training policies selected by those firms in order to cater for those needs. Design/methodology/approach: A survey based…

  18. How closely do the delta(13)C values of Crassulacean Acid metabolism plants reflect the proportion of CO(2) fixed during day and night?

    Science.gov (United States)

    Winter, Klaus; Holtum, Joseph A M

    2002-08-01

    The extent to which Crassulacean acid metabolism (CAM) plant delta(13)C values provide an index of the proportions of CO(2) fixed during daytime and nighttime was assessed. Shoots of seven CAM species (Aloe vera, Hylocereus monocanthus, Kalanchoe beharensis, Kalanchoe daigremontiana, Kalanchoe pinnata, Vanilla pauciflora, and Xerosicyos danguyi) and two C(3) species (teak [Tectona grandis] and Clusia sp.) were grown in a cuvette, and net CO(2) exchange was monitored for up to 51 d. In species exhibiting net dark CO(2) fixation, between 14% and 73.3% of the carbon gain occurred in the dark. delta(13)C values of tissues formed inside the cuvette ranged between -28.7 per thousand and -11.6 per thousand, and correlated linearly with the percentages of carbon gained in the light and in the dark. The delta(13)C values for new biomass obtained solely during the dark and light were estimated as -8.7 per thousand and -26.9 per thousand, respectively. For each 10% contribution of dark CO(2) fixation integrated over the entire experiment, the delta(13)C content of the tissue was, thus, approximately 1.8 per thousand less negative. Extrapolation of the observations to plants previously surveyed under natural conditions suggests that the most commonly expressed version of CAM in the field, "the typical CAM plant," involves plants that gain about 71% to 77% of their carbon by dark fixation, and that the isotopic signals of plants that obtain one-third or less of their carbon in the dark may be confused with C(3) plants when identified on the basis of carbon isotope content alone.

  19. 14C and 13C characteristics of higher plant biomarkers in Washington margin surface sediments

    Science.gov (United States)

    Feng, Xiaojuan; Benitez-Nelson, Bryan C.; Montluçon, Daniel B.; Prahl, Fredrick G.; McNichol, Ann P.; Xu, Li; Repeta, Daniel J.; Eglinton, Timothy I.

    2013-03-01

    Plant wax lipids and lignin phenols are the two most common classes of molecular markers that are used to trace vascular plant-derived OM in the marine environment. However, their 13C and 14C compositions have not been directly compared, which can be used to constrain the flux and attenuation of terrestrial carbon in marine environment. In this study, we describe a revised method of isolating individual lignin phenols from complex sedimentary matrices for 14C analysis using high pressure liquid chromatography (HPLC) and compare this approach to a method utilizing preparative capillary gas chromatography (PCGC). We then examine in detail the 13C and 14C compositions of plant wax lipids and lignin phenols in sediments from the inner and mid shelf of the Washington margin that are influenced by discharge of the Columbia River. Plant wax lipids (including n-alkanes, n-alkanoic (fatty) acids, n-alkanols, and n-aldehydes) displayed significant variability in both δ13C (-28.3‰ to -37.5‰) and Δ14C values (-204‰ to +2‰), suggesting varied inputs and/or continental storage and transport histories. In contrast, lignin phenols exhibited similar δ13C values (between -30‰ and -34‰) and a relatively narrow range of Δ14C values (-45‰ to -150‰; HPLC-based measurement) that were similar to, or younger than, bulk OM (-195‰ to -137‰). Moreover, lignin phenol 14C age correlated with the degradation characteristics of this terrestrial biopolymer in that vanillyl phenols were on average ˜500 years older than syringyl and cinnamyl phenols that degrade faster in soils and sediments. The isotopic characteristics, abundance, and distribution of lignin phenols in sediments suggest that they serve as promising tracers of recently biosynthesized terrestrial OM during supply to, and dispersal within the marine environment. Lignin phenol 14C measurements may also provide useful constraints on the vascular plant end member in isotopic mixing models for carbon source

  20. Effect of cytochalasin B on 3-O-[(14)C]-methyl-D-glucose or D-[U-(14)C]glucose handling by BRIN-BD11 cells.

    Science.gov (United States)

    Cetik, Sibel; Rzajeva, Aigun; Malaisse, Willy J; Sener, Abdullah

    2014-07-01

    The present study aimed to investigate the effects of cytochalasin B (20 μM) on the uptake of 3-O-[(14)C]-methyl-D-glucose or D-[U-(14)C]glucose (8.3 mM each) by BRIN-BD11 cells. Taking into account the distribution space of tritiated water ((3)HOH), which was unexpectedly increased shortly after exposure of the cells to cytochalasin B and then progressively returned to its control values, and that of L-[1-(14)C]glucose, used as an extracellular marker, it was demonstrated that cytochalasin B caused a modest, but significant inhibition of the uptake of D-glucose and its non-metabolized analog by the BRIN-BD11 cells. These findings resemble those observed in acinar or ductal cells of the rat submaxillary gland and displayed a relative magnitude comparable to that found for the inhibition of D-glucose metabolism by cytochalasin B in purified pancreatic islet B cells. These findings reinforce the view that the primary site of action of cytochalasin B is located at the level of the plasma membrane.

  1. Estimating 14C groundwater ages in a methanogenic aquifer

    Science.gov (United States)

    Aravena, Ramon; Wassenaar, Leonard I; Plummer, L. Niel

    1995-01-01

    This paper addresses the problem of 14C age dating of groundwaters in a confined regional aquifer affected by methanogenesis. Increasing CH4 concentrations along the groundwater flow system and 13C and 14C isotopic data for dissolved inorganic carbon, dissolved organic carbon, and CH4 clearly show the effect of methanogenesis on groundwater chemistry. Inverse reaction path modeling using NETPATH indicates the predominant geochemical reactions controlling the chemical evolution of groundwater in the aquifer are incongruent dissolution of dolomite, ion exchange, methanogenesis, and oxidation of sedimentary organic matter. Modeling of groundwater 14C ages using NETPATH indicates that a significant part of groundwater in the Alliston aquifer is less than 13,000 years old; however, older groundwater in the range of 15,000–23,000 years is also present in the aquifer. This paper demonstrates that 14C ages calculated using NETPATH, incorporating the effects of methanogenesis on the carbon pools, provide reasonable groundwater ages that were not possible by other isotopic methods.

  2. Urate-2-14C transport in the rat nephron

    Science.gov (United States)

    Kramp, Ronald A.; Lassiter, William E.; Gottschalk, Carl W.

    1971-01-01

    Intrarenal transport of urate-2-14C was studied in anesthetized rats using the microinjection technic. During saline diuresis, small volumes of urate-2-14C (0.24-0.48 mM) and inulin-3H were injected into surface proximal and distal convoluted tubules, and ureteral urine was collected serially. Total (74-96%) and direct (57-84%) urate recovery increased significantly the more distal the puncture site. Delayed recovery (±20%) remained approximately the same regardless of localization of the microinjection. After proximal injections, total and direct recoveries of urate-2-14C were significantly higher in rats treated with probenecid, pyrazinoate, or PAH than during saline diuresis alone, while the excretion rates were comparable after distal injection. Delayed recovery was not altered by drug administration. The decreased proximal reabsorption of urate is presumably due to an effect of the drugs on the luminal membrane of the nephron. For perfusion at high urate concentrations, nonradioactive urate was added to the injectate (0.89-1.78 mM). Urate-2-14C recovery was almost complete and there was no delayed excretion, demonstrating saturation kinetics. These findings are compatible with a carrier-mediated mechanism for urate transport probably located at the luminal border of the proximal tubular epithelium. No definitive evidence for urate secretion was found in these studies. PMID:5543881

  3. A STUDY ON ADSORPTION AND DESORPTION BEHAVIORS OF 14C FROM A MIXED BED RESIN

    Directory of Open Access Journals (Sweden)

    SEUNG-CHUL PARK

    2014-12-01

    Full Text Available Spent resin waste containing a high concentration of 14C radionuclide cannot be disposed of directly. A fundamental study on selective 14C stripping, especially from the IRN-150 mixed bed resin, was carried out. In single ion-exchange equilibrium isotherm experiments, the ion adsorption capacity of the fresh resin for non-radioactive HCO3− ion, as the chemical form of 14C, was evaluated as 11mg-C/g-resin. Adsorption affinity of anions to the resin was derived in order of NO3− > HCO3− ≥ H2PO4−. Thus the competitive adsorption affinity of NO3− ion in binary systems appeared far higher than that of HCO3− or H2PO4−, and the selective desorption of HCO3− from the resin was very effective. On one hand, the affinity of Co2+ and Cs+ for the resin remained relatively higher than that of other cations in the same stripping solution. Desorption of Cs+ was minimized when the summation of the metal ions in the spent resin and the other cations in solution was near saturation and the pH value was maintained above 4.5. Among the various solutions tested, from the view-point of the simple second waste process, NH4H2PO4 solution was preferable for the stripping of 14C from the spent resin.

  4. Cluster decay of the high-lying excited states in 14C

    Science.gov (United States)

    Tian, Z. Y.; Ye, Y. L.; Li, Z. H.; Lin, C. J.; Li, Q. T.; Ge, Y. C.; Lou, J. L.; Jiang, W.; Li, J.; Yang, Z. H.; Feng, J.; Li, P. J.; Chen, J.; Liu, Q.; Zang, H. L.; Yang, B.; Zhang, Y.; Chen, Z. Q.; Liu, Y.; Sun, X. H.; Ma, J.; Jia, H. M.; Xu, X. X.; Yang, L.; Ma, N. R.; Sun, L. J.

    2016-11-01

    A cluster-transfer experiment of 9Be(9Be,14C → α+10Be)α at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in 14C. This reaction is of extremely large Q-value, making it an excellent case to select the reaction mechanism and the final states in outgoing nuclei. The high-lying resonances in 14C are reconstructed for three sets of well discriminated final states in 10Be. The results confirm the previous decay measurements with clearly improved decay-channel selections and also show a new state at 23.5(1) MeV. The resonant states at 22.4(3) and 24.0(3) MeV decay primarily into the typical molecular states at about 6 MeV in 10Be, indicating a well developed cluster structure in these high-lying states in 14C. Further measurements of more states of this kind are suggested. Supported by the 973 Program of China (2013 CB834402) and National Natural Science Foundation of China (11275011, 11535004)

  5. Cartilage quality in rheumatoid arthritis: comparison of T2* mapping, native T1 mapping, dGEMRIC, {delta}R1 and value of pre-contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian; Scherer, Axel; Kroepil, Patric; Quentin, Michael; Reichelt, Dorothea C.; Lanzman, Rotem S.; Mathys, Christian; Blondin, Dirk; Wittsack, Hans-Joerg; Antoch, Gerald; Miese, Falk [University Duesseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany); Koerbl, Birthe [Heinrich-Heine-University, Department of Endocrinology, Diabetology and Rheumatology, Medical Faculty, Duesseldorf (Germany); Heinrich-Heine-University, Leibniz Centre for Diabetes Research, Institute of Biometrics and Epidemiology, German Diabetes Centre, Duesseldorf (Germany); Bittersohl, Bernd; Zilkens, Christoph [Heinrich-Heine-University, Department of Orthopaedics, Medical Faculty, Duesseldorf (Germany); Hofer, Matthias [Heinrich-Heine-University, Medical Education Group, Medical School, Duesseldorf (Germany); Schneider, Matthias; Ostendorf, Benedikt [Heinrich-Heine-University, Department of Endocrinology, Diabetology and Rheumatology, Medical Faculty, Duesseldorf (Germany)

    2012-06-15

    To prospectively evaluate four non-invasive markers of cartilage quality - T2* mapping, native T1 mapping, dGEMRIC and {delta}R1 - in healthy volunteers and rheumatoid arthritis (RA) patients. Cartilage of metacarpophalangeal (MCP) joints II were imaged in 28 consecutive subjects: 12 healthy volunteers [9 women, mean (SD) age 52.67 (9.75) years, range 30-66] and 16 RA patients with MCP II involvement [12 women, mean (SD) age 58.06 (12.88) years, range 35-76]. Sagittal T2* mapping was performed with a multi-echo gradient-echo on a 3 T MRI scanner. For T1 mapping the dual flip angle method was applied prior to native T1 mapping and 40 min after gadolinium application (delayed gadolinium-enhanced MRI of cartilage, dGEMRIC, T1{sub Gd}). The difference in the longitudinal relaxation rate induced by gadolinium ({delta}R1) was calculated. The area under the receiver operating characteristic curve (AROC) was used to test for differentiation of RA patients from healthy volunteers. dGEMRIC (AUC 0.81) and {delta}R1 (AUC 0.75) significantly differentiated RA patients from controls. T2* mapping (AUC 0.66) and native T1 mapping (AUC 0.66) were not significantly different in RA patients compared to controls. The data support the use of dGEMRIC for the assessment of MCP joint cartilage quality in RA. T2* and native T1 mapping are of low diagnostic value. Pre-contrast T1 mapping for the calculation of {delta}R1 does not increase the diagnostic value of dGEMRIC. (orig.)

  6. Degradation of /sup 14/C-labeled lignins and /sup 14/C-labeled aromatic acids by fusarium solani

    Energy Technology Data Exchange (ETDEWEB)

    Norris, D.M.

    1980-08-01

    Abilities of isolate AF-W1 of Fusarium solani to degrade the side chain and the ring structure of synthetic dehydrogenative polymerizates, aromatic acids, or lignin in sound wood were investigated under several conditions of growth substrate or basal medium and pH. Significant transformations of lignins occurred in 50 days in both unextracted and extracted sound wood substrances with 3% malt as the growth substrate and the pH buffered initially at 4.0 with 2,2-dimethylsuccinate. Degradation of lignin in such woods also occurred under unbuffered pH conditions when a basal medium of either 3% malt or powdered cellulose in deionized water was present. Decomposition of the lignin in these woods did not occur in cultures where D-glucose was present as a growth substrate. F. solani significantly transformed, as measured as evolved /sup 14/CO/sub 2/, both synthetic side chain (beta, gamma)-/sup 14/C- and U-ring-/sup 14/C-labeled lignins in 30 days under liquid culture conditions of only distilled deionized water and no pH adjustment. Degradation of dehydrogenative polymerizates by F. solani was reduced drastically when D2 was the liquid medium. AF-W1 also cleaved the alpha-/sup 14/C from p- hydroxybenzoic acid and evolved /sup 14/CO/sub 2/ from the substrace, (3-/sup 14/C) cinnamic acid. Thus, the fungus cleaved side chain carbon from substrate that originally lacked hydroxyl substitution on the aromatic nucleus. Surprisingly, small amounts of /sup 14/C cleaved from aromatic acids by F. solani were incorporated into cell mass. Initial buffering of the culture medium to pH 4.0 or 5.0 with 0.1 M2,2-dimethylsuccinate significantly increased F. solani degradation of all lignins or aromatic acids. Results indicated that AF-W1 used lignin as a sole carbon source.

  7. Method of 14C Sample Preparation for AMS Measurement

    Directory of Open Access Journals (Sweden)

    YANG Xu-ran

    2015-02-01

    Full Text Available In order to carry out the application research of 14C by accelerator mass spectrometry (AMS, the principle of sample preparation were systematically studied and more attention was paid to improve the preparation process efficiently. The set of integrated system of sample preparation was built up on the research. The experimental results showed that the sample preparation scheme was able to meet the demand of AMS measurement.

  8. Residues of {sup 14}C-paclobutrazol in mangoes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Maria A.; Tornisielo, Valdemar L.; Castanho, Giuliane M., E-mail: macosta@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Ecotoxicologia

    2009-07-01

    Paclobutrazol (PBZ) is a growth regulator used in agricultural systems whose purpose is the control of vegetative growth, stimulating the reproductive capacity of plants. This growth regulator remains active in soil for a long time and its half-life varies with the type of soil and climatic conditions, can severely affect the development of crops. This work aimed to study the residues / metabolites of {sup 14}C-PBZ in mango pulp Tommy Atkins. The tests were performed with mangoes grown in pots stainless steel and application of {sup 14}C-PBZ was performed by the soil projection of the crown, and the mangoes tested in two periods, one year and two years after application. To evaluate the levels of residues of {sup 14}C-PBZ was realize the burning of 200 mg of pulp on biological oxidized and detached {sup 14}CO{sub 2} was detected by liquid scintillation spectrophotometer. The results were 1.65 % of residue of PBZ on fruit collected after two years of application and 4.30 % of residue of PBZ collected on fruit after a year of application and also can see that the product remained in the soil for more than one year, is translocated to the plant and reach the edible part, the pulp fruit. The identification of residual {sup 14}C- PBZ/metabolites by thin-layer chromatography did not reveal any pattern of PBZ / metabolites due to the low activity detected in the samples. Therefore, another procedure was performed for extraction and then analyzed by high performance liquid chromatography (HPLC) for detection of metabolites in the PBZ of mango pulp. (author)

  9. Atmospheric CO{sub 2} concentrations and {delta}{sup 13}C values across the Antarctic Circumpolar Current between New Zealand and Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Longinelli, Antonio; Selmo, Enricomaria [Univ. of Parma, (Italy). Dept. of Earth Sciences; Giglio, Federico; Langone, Leonardo; Lenaz, Renzo; Ori, Carlo [Consiglio Nazionale delle Ricerche, Bologna (Italy). Inst. of Marine Sciences, Marine Geology Section

    2007-02-15

    Measurements of atmospheric CO{sub 2} concentrations were repeatedly carried out on the vessel 'Italica' of the Italian National Research Program in Antarctica, during cruises from Italy to Antarctica. Discrete air samples were also collected in 4-L Pyrex flasks during these cruises in order to carry out {delta}{sup 13}C analyses on atmospheric CO{sub 2}. The results acquired between New Zealand and Antarctica are reported here. The mean growth rate of the CO{sub 2} concentration from 1996 to 2003 in this area of the Southern Oceans is of about 1.8 ppmv/yr, in good agreement with NOAA/CMDL measurements. The rates of increase from cruise to cruise are rather variable. From 1996-1997 to 1998-1999 cruise the yearly growth rate is 2.75 ppmv/yr, close to the large growth rates measured in several areas and mainly related to the most severe El Nino event of the last years. The other yearly growth rates are of about 1.3 and 2 ppmv for the periods 1998-1999 to 2001-2002 and 2001-2002 to 2003-2004, respectively. The large difference between these two values is probably related to the uncertainty on the only two 2001-2002 discrete measurements of CO{sub 2} concentration in this area. The measured {delta}{sup 13}C values show two completely different distributions and a large interannual variability. The 1998-1999, 2002-2003, and 2003-2004 results obtained between about 55 deg S and 65 deg S across the Antarctic Polar Front show a marked negativization of up to more than 0.2% when compared to the background values. The results are related to local source regions of CO{sub 2}, as frequently found in the Southern Ocean by several authors; the negative {delta}{sup 13}C values are tentatively related to the possible contribution of different causes. Among them, the southward negative gradient of {delta}{sup 13}C of the dissolved inorganic carbon, the contribution from upwelling deep waters and from subsurface processes between the Northern SubAntarctic Front and the

  10. Atmospheric CO{sub 2} concentrations and (delta){sup 13}C values across the Antarctic Circumpolar Current between New Zealand and Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Longinelli, Antonio; Selmo, Enricomaria [Univ. of Parma, (Italy). Dept. of Earth Sciences; Giglio, Federico; Langone, Leonardo; Lenaz, Renzo; Ori, Carlo [Consiglio Nazionale delle Ricerche, Bologna (Italy). Inst. of Marine Sciences, Marine Geology Section

    2007-02-15

    Measurements of atmospheric CO{sub 2} concentrations were repeatedly carried out on the vessel 'Italica' of the Italian National Research Program in Antarctica, during cruises from Italy to Antarctica. Discrete air samples were also collected in 4-L Pyrex flasks during these cruises in order to carry out (delta){sup 13}C analyses on atmospheric CO{sub 2}. The results acquired between New Zealand and Antarctica are reported here. The mean growth rate of the CO{sub 2} concentration from 1996 to 2003 in this area of the Southern Oceans is of about 1.8 ppmv/yr, in good agreement with NOAA/CMDL measurements. The rates of increase from cruise to cruise are rather variable. From 1996-1997 to 1998-1999 cruise the yearly growth rate is 2.75 ppmv/yr, close to the large growth rates measured in several areas and mainly related to the most severe El Nino event of the last years. The other yearly growth rates are of about 1.3 and 2 ppmv for the periods 1998-1999 to 2001-2002 and 2001-2002 to 2003-2004, respectively. The large difference between these two values is probably related to the uncertainty on the only two 2001-2002 discrete measurements of CO{sub 2} concentration in this area. The measured (delta){sup 13}C values show two completely different distributions and a large interannual variability. The 1998-1999, 2002-2003, and 2003-2004 results obtained between about 55 deg S and 65 deg S across the Antarctic Polar Front show a marked negativization of up to more than 0.2% when compared to the background values. The results are related to local source regions of CO{sub 2}, as frequently found in the Southern Ocean by several authors; the negative (delta){sup 13}C values are tentatively related to the possible contribution of different causes. Among them, the southward negative gradient of (delta){sup 13}C of the dissolved inorganic carbon, the contribution from upwelling deep waters and from subsurface processes between the Northern SubAntarctic Front and the

  11. Bioenergetics of three aquatic insects determined by radioisotopic analyses. [/sup 51/Cr and /sup 14/C tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    McCullough, D.A.

    1975-08-01

    The bioenergetics of Simulium spp. and Cheumatopsyche analis from Rattlesnake Springs and Snively Creek, respectively, Benton County, Washington and Tricorthodes minutus from Deep Creek, Oneida County, Idaho were studied using a variety of techniques. Ingestion rates were measured using food sources (diatoms, finely ground watercress, bacteria, and blue-green algae) labelled with /sup 51/Cr and /sup 14/C. Theoretical ingestion rates were calculated from analyses of gut weights and digestion times. Assimilation efficiencies (AE) were determined using the /sup 14/C and dual-label (/sup 51/Cr, /sup 14/C) methods and the ash-ratio technique. The dual-label method provided reliable results when leaching of isotopes from food and feces were not significant. Provided the /sup 51/Cr activity density of food is sufficient, the time required for digestion can also be more accurately determined with /sup 51/Cr than with /sup 14/C. The ash-ratio method provided a wide range of AE values and is not as reliable as the dual-label method because mineral assimilationis unpredictable. Assimilation rates were derived for these animals using the ingestion rate and AE, by several methods employing /sup 14/C uptake curves, and by differences in /sup 51/Cr- and /sup 14/C-derived accumulation values. Methods used to measure other energy budget components are also given. A system was developed for combusting biological samples containing /sup 14/C and determining cpm /sup 14/C and total carbon from a single sample. This method employs Van Slyke wet oxidation, forced circulation and scrubbing of the gases of combustion, and collection of CO/sub 2/ in ethanolamine. Radioactivity in this system was determined by scintillation counting and total carbon by a gravimetric precipitation method. (auth)

  12. Seasonal inter-relationships in atmospheric methane and companion delta13C values: effects of sinks and sources

    Energy Technology Data Exchange (ETDEWEB)

    Lassey, K. R.; Mikaloff Fletcher, S. E. (NIWA, Wellington (New Zealand)), e-mail: k.lassey@niwa.co.nz; Allan, W. (Allan Planning and Research Ltd., Petone (New Zealand))

    2011-07-15

    Recent developments in applying carbon-isotope information to better understand regional and global methane budgets infer a strong role by a highly fractionating seasonal sink such as atomic chlorine. Specifically, OH as the predominant seasonal sink cannot account for the 'phase ellipses' based on observed seasonal cycles of methane mixing ratio and isotope ratio, delta13C. Although a strong role by atomic chlorine is inferred empirically, open questions remain about the interplay between sources and sinks in determining the properties of phase ellipses. This paper employs a simple didactic model of the seasonal cycling of atmospheric methane to understand such interplay. We demonstrate that a single seasonal sink and seasonal source act together to imprint anti-phase seasonalities on atmospheric methane and delta13C, which lead to phase ellipses that collapse onto a straight line with slope characteristic of that sink. This explains empirical findings of these anti-phase relationships in three-dimensional modelling studies. We also demonstrate that multiple seasonal sinks acting with a seasonal source can yield surprising properties for the phase ellipse that not only explain some features of phase ellipses reported in modelling studies but also have the potential to explain marked inter-annual variation in phase ellipses based on observation

  13. Determination of {sup 14}C concentrations in vegetation collected near a nuclear power plant with boiling water reactors and estimation of an amount of {sup 14}C released from the plant

    Energy Technology Data Exchange (ETDEWEB)

    Momoshima, Noriyuki [Kyushu Univ., Fukuoka (Japan). Faculty of Science; Kawamura, Hidehisa; Takashima, Yoshimasa; Ezumi, Shuichi

    1995-06-01

    Concentrations of {sup 14}C in vegetation collected near a nuclear power plant with two boiling water reactors were measured by a liquid scintillation counting technique to estimate the effects of {sup 14}C released from the nuclear power plant on the environment. The average {sup 14}C concentration in the vegetation collected near the nuclear plant was about 20 mBq/g carbon higher than that collected from the environment where there was no effect of nuclear power plants. The increase in the {sup 14}C concentration in the vegetation was attributed to photosynthetic uptake of {sup 14}CO{sub 2} discharged from the nuclear power plant under normal operation. The elevated level of {sup 14}C content in the vegetation enables us to evaluate the discharged rate of {sup 14}C from the nuclear power plant and has led to an estimation of 0.36 TBq/(GW{center_dot}a) which is comparable to values reported on other BWRs. (author).

  14. Validation of {sup 14} C-urea breath test for diagnosis of Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Mattar, Rejane; Silva, Fernando Marcuz; Alexandrino, Ana Maria; Laudanna, Antonio Atilio [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Dept. de Gastroenterologia]. E-mail: shiroineko@uol.com.br

    1999-02-01

    The aim of this study was to validate the {sup 14} C-urea breath test for use in diagnosis of Helicobacter pylori infection. Thirty H. pylori positive patients, based on histologic test and thirty H. pylori negative patients by histology and anti-H pylori IgG entered the study. Fasting patients drank 5 uCi of {sup 14} C-urea in 20 ml of water. Breath samples were collected at O, 5, 10, 15, 20 and 30 min. The difference of cpm values between the two groups was significant at all the time intervals, besides time 0 (p < 0.0001). At 20 min, the test gave 100% sensitivity and specificity with a cut-off value of 562 cpm. Females were higher expirers than males (p=0.005). {sup 14} C-urea breath test is highly accurate for Helicobacter pylori diagnosis. It is fast, simple and should be the non-invasive test used after treating Helicobacter pylori infection. (author)

  15. sup 14 C-urea breath test for the detection of Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuyzen van Zanten, S.J.; Tytgat, K.M.; Hollingsworth, J.; Jalali, S.; Rshid, F.A.; Bowen, B.M.; Goldie, J.; Goodacre, R.L.; Riddell, R.H.; Hunt, R.H. (McMaster Univ., Hamilton, Ontario (Canada))

    1990-04-01

    The high urease activity of Helicobacter pylori can be used to detect this bacterium by noninvasive breath tests. We have developed a {sup 14}C-urea breath test which uses 5 microCi {sup 14}C with 50 mg nonradioactive urea. Breath samples are collected at baseline and every 30 min for 2 h. Our study compared the outcome of the breath test to the results of histology and culture of endoscopically obtained gastric biopsies in 84 patients. The breath test discriminated well between the 50 positive patients and the 34 patients negative for Helicobacter pylori: the calculated sensitivity was 100%, specificity 88%, positive predictive value 93%, and negative predictive value 100%. Treatment with bismuth subsalicylate and/or ampicillin resulted in lower counts of exhaled {sup 14}CO{sub 2} which correlated with histological improvement in gastritis. The {sup 14}C-urea breath test is a better gold standard for the detection of Helicobacter pylori than histology and/or culture.

  16. Results of {sup 14}C analysis on low-level reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.J.; Kotzer, T.G

    2000-04-01

    An invitation from the University of Glasgow to participate in an international intercomparison of {sup 14}C analysis and the increased need for quality assurance for measurements performed at the Low-Level Laboratory by AECL's Environmental Technologies Branch (ETB), Chalk River Laboratories, prompted the initiation of this work. Standard {sup 14}C samples from the IAEA and from the ETB were analyzed and compared to their reference values. All analyses agreed well with reported values and confirmed that the ETB can reliably measure {sup 14}C between 50 and 500 Bq/kg C. Samples from the University of Glasgow, Scotland, were also analyzed and reported. The results of counting various CO{sub 2} blank materials (dry ice from a CO{sub 2}-siphon and limestone) showed that the source of CO{sub 2} does not have an effect on background count rate or counter efficiency. The ETB's lower limit of detection (LLD) has been calculated to be 10 -20 Bq/kg C and the determination limit (L{sub Q}) for samples during the ETB's routine operations has been documented to be 44 Bq/kg C. (author)

  17. Measurement of local cerebral blood flow with (/sup 14/C)iodoantipyrine in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Jay, T.M.; Lucignani, G.; Crane, A.M.; Jehle, J.; Sokoloff, L.

    1988-02-01

    Local cerebral blood flow was measured in the mouse by means of the (/sup 14/C)iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the (/sup 14/C)iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the (/sup 14/C)iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

  18. Soil microarthropods and their bioindicator value regarding the bio-edaphic conditions in forest ecosystems of Danube Delta

    Directory of Open Access Journals (Sweden)

    Călugăr A.,

    2016-05-01

    Full Text Available The main objective of this study was to compare soil mesofauna communities in natural and anthropogenic forests from Danube Delta Biosphere Reserve and establish a baseline data in monitoring the disturbed sites. The abundance and diversity of edaphic microarthropods were analyzed in five plots, three of them being natural forests and two plantations (Canada poplar, and respectively willow. The mites from Trombidiformes and Oribatida were closely investigated being identified at family level. Qualitative analysis of edaphic microarthropods evidences numerical dominance of mites, excepting only one stand (Canada poplar plantation. Among mites Oribatida owns the biggest weight (76.6 - 94.1% of the total mites, followed by Trombidiformes or Mesostigmata. Among insects the collembolans hold higher density in the poplar plantation, and the lowest one in the willow plantation. Structure of mites communities differs between the investigated ecosystems both in quantitative and qualitative aspects depending on particular conditions of each plot.

  19. Reconstruction of Monsoon Driven South China Sea Surface Ocean Circulation using Coral Δ14C

    Science.gov (United States)

    Goodkin, N.; Bolton, A.; Karnauskas, K. B.; Hughen, K. A.; Griffin, S.; Druffel, E. R. M.

    2016-12-01

    The need to improve our understanding of annual and decadal climate behavior in the South China Sea is increasingly important, as this region includes the largest population density globally but encompasses few climate records. Here we present a record of annually resolved Δ14C from a coral collected off the coast of Nha Trang, Vietnam (12°12'49.90″N, 109°18'17.51″E), that reveals a significant correlation to regional winter sea level pressure (SLP) and sea surface temperature (SST), and extends back more than 400 years. Coral Δ14C during thermonuclear bomb testing indicates the presence of wet-season (summer) upwelling, demonstrated by low Δ14C values for both baseline and peak values relative to other records in the region (Bolton et al., 2016, Radiocarbon). However, annually resolved pre-bomb ∆14C correlates significantly to regional dry-season (winter) SLP and SST, indicating that annual variability is driven by changes to the East Asian Winter Monsoon (EAWM) and subsequent down-welling at this site. Spectral density is focused at 25, 11.8, 7, 4, and 3.2 years per cycle reflecting a range of influences on surface advection variability including the EAWM (D'Arrigo et al., 2005, GRL) and the El Nino Southern Oscillation (ENSO). Spectral power at all of these frequencies decreases following the Little Ice Age ( 1600-1850?) to today, indicating that wind driven surface advection was more variable when hemispheric temperatures were cooler. Decadal variance in the past 100 years is significantly correlated to variance records of the Arctic Oscillation (AO, Thompson and Wallace, 1989, GRL), suggesting that increasing variance in the EAWM may be tied to increasing variance of the AO during the Little Ice Age and vice versa.

  20. Concentrations and {delta}{sup 13}C values of atmospheric CO{sub 2} from oceanic atmosphere through time: polluted and non-polluted areas

    Energy Technology Data Exchange (ETDEWEB)

    Longinelli, Antonio; Selmo, Enrico [Univ. of Parma (Italy). Dept. of Earth Sciences; Lenaz, Renzo; Ori, Carlo [C.N.R., ISMAR, Bologna (Italy). Dept. of Marine Geology

    2005-11-01

    CO{sub 2} is one of the primary agents of global climate changes. The increase of atmospheric CO{sub 2} concentration is essentially related to human-induced emissions and, particularly, to the burning of fossil fuel whose {delta}{sup 13}C values are quite negative. Consequently, an increase of the CO{sub 2} concentration in the atmosphere should be paralleled by a decrease of its {delta}{sup 13}C. Continuous and/or spot measurements of CO{sub 2} concentrations were repeatedly carried out during the last decade and in the same period of the year along hemispheric courses from Italy to Antarctica on a vessel of the Italian National Research Program in Antarctica. During these expeditions, discrete air samples were also collected in 4-l Pyrex flasks in order to carry out precise carbon isotope analyses on atmospheric CO{sub 2} from different areas, including theoretically 'clean' open ocean areas, with the main purpose of comparing these open ocean results with the results obtained by the National Oceanic and Atmospheric Administration/World Meteorological Organization (NOAA/WMO) at land-based stations. According to the data obtained for these two variables, a relatively large atmospheric pollution is apparent in the Mediterranean area where the CO{sub 2} concentration has reached the value of 384 ppmv while quite negative {delta}{sup 13}C values have been measured only occasionally. In this area, southerly winds probably help to reduce the effect of atmospheric pollution even though, despite a large variability of CO{sub 2} concentrations, these values are consistently higher than those measured in open ocean areas by a few ppmv to about 10 ppmv. A marked, though non-continuous, pollution is apparent in the area of the Bab-el-Mandeb strait where {delta}{sup 13}C values considerably more negative than in the Central and Southern Red Sea were measured. The concentration of atmospheric CO{sub 2} over the Central Indian Ocean increased from about 361 ppmv at

  1. Concentrations and (delta){sup 13}C values of atmospheric CO{sub 2} from oceanic atmosphere through time: polluted and non-polluted areas

    Energy Technology Data Exchange (ETDEWEB)

    Longinelli, Antonio; Selmo, Enrico [Univ. of Parma (Italy). Dept. of Earth Sciences; Lenaz, Renzo; Ori, Carlo [C.N.R., ISMAR, Bologna (Italy). Dept. of Marine Geology

    2005-11-15

    CO{sub 2} is one of the primary agents of global climate changes. The increase of atmospheric CO{sub 2} concentration is essentially related to human-induced emissions and, particularly, to the burning of fossil fuel whose (delta){sup 13}C values are quite negative. Consequently, an increase of the CO{sub 2} concentration in the atmosphere should be paralleled by a decrease of its (delta){sup 13}C. Continuous and/or spot measurements of CO{sub 2} concentrations were repeatedly carried out during the last decade and in the same period of the year along hemispheric courses from Italy to Antarctica on a vessel of the Italian National Research Program in Antarctica. During these expeditions, discrete air samples were also collected in 4-l Pyrex flasks in order to carry out precise carbon isotope analyses on atmospheric CO{sub 2} from different areas, including theoretically 'clean' open ocean areas, with the main purpose of comparing these open ocean results with the results obtained by the National Oceanic and Atmospheric Administration/World Meteorological Organization (NOAA/WMO) at land-based stations. According to the data obtained for these two variables, a relatively large atmospheric pollution is apparent in the Mediterranean area where the CO{sub 2} concentration has reached the value of 384 ppmv while quite negative (delta){sup 13}C values have been measured only occasionally. In this area, southerly winds probably help to reduce the effect of atmospheric pollution even though, despite a large variability of CO{sub 2} concentrations, these values are consistently higher than those measured in open ocean areas by a few ppmv to about 10 ppmv. A marked, though non-continuous, pollution is apparent in the area of the Bab-el-Mandeb strait where (delta){sup 13}C values considerably more negative than in the Central and Southern Red Sea were measured. The concentration of atmospheric CO{sub 2} over the Central Indian Ocean increased from about 361 ppmv at

  2. Human folate metabolism using 14C-accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Arjomand, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Duecker, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, P. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zulim, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bucholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vogel, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-03-25

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkin's disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer.

  3. Tree-ring 14C and CO2 emissions at Mammoth Mountain and Yellowstone, USA

    Science.gov (United States)

    Bergfeld, D.; McGeehin, J. P.; King, J.; Heasler, H.; Evans, W. C.

    2010-12-01

    A large pulse of magmatic CO2 began venting through soils on the flanks of Mammoth Mountain CA within months of a local seismic swarm in 1989. Previous workers have shown that the CO2 efflux rate was large enough to kill ~0.5 km2 of forest and cause substantial depletion of 14C in the wood of surviving trees at the edges of the kill zones. CO2 efflux at Mammoth Mountain continues to be well-studied, in part because of the obvious link between the seismic swarm and the onset of outgassing. A somewhat similar event apparently occurred a decade previously in the Yellowstone caldera, where we see a record of 14C depletion of 10-25% in a tree at Cooking Hillside in the Mud Volcano area. The 14C levels in tree core data show that CO2 emissions began to increase during a local seismic swarm in 1978. A huge drop in 14C in the 1979 growth ring suggests that CO2 emissions increased about 5-fold over values earlier in the decade. The emissions spike persisted into 1980 but at greatly reduced levels. This event at Mud Volcano occurred in a thermal area long known to emit CO2 gas and was associated with a substantial increase in surface heating and steam emission, in contrast to the case of Mammoth Mountain. However, the two events share some important similarities: increased CO2 emissions began within months of the onset of shallow (emissions peaked within 1-2 years later, and peak emissions are estimated at ~1000 tonnes of CO2 per day. Seismicity in both cases was likely driven by CO2-rich hydrous fluids; intrusion of magma into the shallow crust seems unlikely, particularly at Yellowstone where the youngest intra-caldera lavas are 70 ka. These similarities imply that, while each event has unique attributes, both are more likely variants on a process that may be fairly common in areas of magmatism. Additional tree coring at Mammoth Mountain will allow a direct comparison between 14C depletion and annual CO2 flux surveys. Ongoing tree-core 14C studies at Yellowstone focus on

  4. Tritium and 14C background levels in pristine aquatic systems and their potential sources of variability.

    Science.gov (United States)

    Eyrolle-Boyer, Frédérique; Claval, David; Cossonnet, Catherine; Zebracki, Mathilde; Gairoard, Stéphanie; Radakovitch, Olivier; Calmon, Philippe; Leclerc, Elisabeth

    2015-01-01

    Tritium and (14)C are currently the two main radionuclides discharged by nuclear industry. Tritium integrates into and closely follows the water cycle and, as shown recently the carbon cycle, as does (14)C (Eyrolle-Boyer et al., 2014a, b). As a result, these two elements persist in both terrestrial and aquatic environments according to the recycling rates of organic matter. Although on average the organically bound tritium (OBT) activity of sediments in pristine rivers does not significantly differ today (2007-2012) from the mean tritiated water (HTO) content on record for rainwater (2.4 ± 0.6 Bq/L and 1.6 ± 0.4 Bq/L, respectively), regional differences are expected depending on the biomass inventories affected by atmospheric global fallout from nuclear testing and the recycling rate of organic matter within watersheds. The results obtained between 2007 and 2012 for (14)C show that the levels varied between 94.5 ± 1.5 and 234 ± 2.7 Bq/kg of C for the sediments in French rivers and across a slightly higher range of 199 ± 1.3 to 238 ± 3.1 Bq/kg of C for fish. This variation is most probably due to preferential uptake of some organic carbon compounds by fish restraining (14)C dilution with refractory organic carbon and/or with old carbonates both depleted in (14)C. Overall, most of these ranges of values are below the mean baseline value for the terrestrial environment (232.0 ± 1.8 Bq/kg of C in 2012, Roussel-Debet, 2014a) in relation to dilution by the carbonates and/or fossil organic carbon present in aquatic systems. This emphasises yet again the value of establishing regional baseline value ranges for these two radionuclides in order to account for palaeoclimatic and lithological variations. Besides, our results obtained from sedimentary archive investigation have confirmed the delayed contamination of aquatic sediments by tritium from the past nuclear tests atmospheric fallout, as recently demonstrated from data chronicles (Eyrolle

  5. Strategy of valid 14C dates choice in syngenetic permafrost

    Directory of Open Access Journals (Sweden)

    Y. K. Vasil'chuk

    2014-11-01

    Full Text Available The main problem of radiocarbon dating within permafrost is the uncertain reliability of the 14C dates. Syngenetic sediments contain allochthonous organic deposit that originated at a distance from its present position. Due to the very good preservation of organic materials in permafrost conditions and numerous re-burials of the fossils from ancient deposits into younger ones the dates could be both younger and older than the true age of dated material. The strategy for the most authentic radiocarbon date selection for dating of syncryogenic sediments is considered taking into account the fluvial origin of the syngenetic sediments. The re-deposition of organic material is discussed in terms of cyclic syncryogenic sedimentation and also the possible re-deposition of organic material in subaerial-subaqueous conditions. The advantages and the complications of dating organic micro-inclusions from ice wedges by the accelerator mass spectrometry (AMS method are discussed applying to true age of dated material search. Radiocarbon dates of different organic materials from the same samples are compared. The younger age of the yedoma from cross-sections of Duvanny Yar in Kolyma River and Mamontova Khayata in the mouth of Lena River is substantiated due to the principle of the choice of the youngest 14C date from the set.

  6. {sup 1}4C Accelerator mass spectrometry in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Carvalho, C.R.A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica

    2011-07-01

    Radiocarbon Accelerator Mass Spectrometry is an ultra-sensitive technique that enables the direct measurement of carbon isotopes in samples as small as a few milligrams. The possibility of dating or tracing rare or even compound specific carbon samples has application in many fields of science such as Archaeology, Geosciences and Biomedicine. Several kinds of material such as wood, charcoal, carbonate and bone can be chemically treated and converted to graphite to be measured in the accelerator system. The Physics Institute of Universidade Federal Fluminense (UFF), in Brazil will soon be able to perform the complete {sup 14}C-AMS measurement of samples. At the Nuclear Chronology Laboratory (LACRON) samples are prepared and converted to carbon dioxide. A stainless steel vacuum system was constructed for carbon dioxide purification and graphitization is performed in sealed tubes in a muffle oven. Graphite samples will be analyzed in a 250 kV Single Stage Accelerator produced by National Electrostatic Corporation which will be installed in the beginning of 2012. With the sample preparation laboratory at LACRON and the SSAMS system, the Physics Institute of UFF will be the first {sup 14}C-AMS facility in Latin America. (author)

  7. Airy structure in $^{16}$O+$^{14}$C nuclear rainbow scattering

    CERN Document Server

    Ohkubo, S

    2015-01-01

    The Airy structure in $^{16}$O+$^{14}$C rainbow scattering is studied with an extended double folding (EDF) model that describes all the diagonal and off-diagonal coupling potentials derived from the microscopic realistic wave functions for $^{16}$O using a density-dependent nucleon-nucleon force. The experimental angular distributions at $E_L$=132, 281 and 382.2 MeV are well reproduced by the calculations. By studying the energy evolution of the Airy structure, the Airy minimum at around $\\theta$=76$^\\circ$ in the angular distribution at $E_L$=132 MeV is assigned as the second order Airy minimum $A2$ in contrast to the recent literature which assigns it as the third order $A3$. The Airy minima in the 90$^\\circ$ excitation function is investigated in comparison with well-known $^{16}$O+$^{16}$O and $^{12}$C+$^{12}$C systems. Evolution of the Airy structure into the molecular resonances with the $^{16}$O+$^{14}$C cluster structure in the low energy region around $E_{c.m.}$=30 MeV is discussed. It is predicted ...

  8. Synthesis of /sup 14/C-labelled crotamiton

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, N.K.; Potdar, S.V.; Ball, T.J. (CIBA-GEIGY Corp., Ardsley, NY (USA). Pharmaceuticals Div.)

    1982-01-01

    The synthesis of /sup 14/C-labelled crotamiton, which is a fungicide, an insecticide as well as a scabicide is described. Starting from 2-bromonitrobenzene and Cu/sup 14/CN, o-toluidine, labelled with /sup 14/C at the methyl group was prepared by the following sequence of reactions: NO/sub 2/-C/sub 6/H/sub 4/-Br ..-->.. NO/sub 2/-C/sub 6/H/sub 4/-/sup 14/CN ..-->.. NO/sub 2/-C/sub 6/H/sub 4/-/sup 14/COOH ..-->.. NO/sub 2/-C/sub 6/H/sub 4/-/sup 14/CH/sub 2/OH ..-->.. NO/sub 2/-C/sub 6/H/sub 4/-/sup 14/CH/sub 2/Br ..-->.. NH/sub 2/-C/sub 6/H/sub 4/-/sup 14/CH/sub 3/. Labelled o-toluidine was then heated with crotonic anhydride to give crotonic acid o-toluidide which was then ethylated by treatment with sodium hydride and ethyl iodide to obtain labelled crotamiton.

  9. Cluster Decay of the High-lying excited states in $^{14}$C

    CERN Document Server

    Tian, Z Y; Li, Z H; Lin, C J; Li, Q T; Ge, Y C; Lou, J L; Jiang, W; Li, J; Yang, Z H; Feng, J; Li, P J; Chen, J; Liu, Q; Zang, H L; Yang, B; Zhang, Y; Chen, Z Q; Liu, Y; Sun, X H; Ma, J; Jia, H M; Xu, X X; Yang, L; Ma, N R; Sun, L J

    2016-01-01

    A cluster-transfer experiment of $^9\\rm{Be}(^9\\rm{Be},^{14}\\rm{C}\\rightarrow\\alpha+^{10}\\rm{Be})\\alpha$ at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in $^{14}$C. This reaction is of extremely large $Q$-value, making it an excellent case to select the reaction mechanism and the final states in outgoing nuclei. The high-lying resonances in $^{14}$C are reconstructed for three sets of well discriminated final states in $^{10}$Be. The results confirm the previous decay measurements with clearly improved decay-channel selections and show also a new state at 23.5(1) MeV. The resonant states at 22.4(3) and 24.0(3) MeV decay primarily into the typical molecular states at about 6 MeV in $^{10}$Be, indicating a well developed cluster structure in these high-lying states in $^{14}$C. Further measurements of more states of this kind are suggested.

  10. Cutaneous uptake of 14C-HD vapor by the hairless guinea pig. Technical report, December 1992-June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Logan, T.P.; Bongiovanni, R.; Millard, C.B.; Shutz, M.B.; Schultz, S.M.

    1996-10-01

    The hairless guinea pig (HGP) is used by our laboratory to model the human cutaneous response to sulfur mustard (HD) exposure. We have determined the HD content in the skin of HOP after 7-minute exposures to vapors saturated with a mixture of HD and 14C-HD. Concentration/time (C1) values in the range of 2 mg/sq cm/min were determined by counting skin 14C disintegrations per minute (dpm) in animals euthanized immediately after exposure. These values are similar to human penetration rates obtained by other investigators. A direct relationship between C1 and relative humidity was demonstrated in 5 of 6 studies. A rate curve monitoring the reduction in skin 14C dpm was developed for animals euthanized between 0 and 24 hours post exposure. This curve showed the greatest change after 1 hour. Epidermal and dermal distribution of 14C at 24 hours was measured for two animals. Site preference for HD penetration, multiple use of a vapor cap containing HD, and 14C content of adhesive tape were also investigated with radiolabeled HD to evaluate other aspects of the experimental model. These results contribute to a better understanding of the cutaneous response to HD in the HGP model.

  11. The anomalous $^{14}$C-dating $\\beta$ decay problem revisited

    CERN Document Server

    Qi, Chong

    2010-01-01

    The anomalous inhibition of $^{14}$C-dating $\\beta$ decay rate is restudied in terms of shell-model calculations in the $jj$ coupling scheme with both realistic and empirical Hamiltonians. It is seen that the accidental cancellation of the decay strength is dominated by the mixing effect of two configurations of the final state wave function, $|0p^{-2}_{1/2}>$ and $|0p_{3/2}^{-1}0p_{1/2}^{-1}>$. By decomposing the effective interactions into different tensor components, it is clearly seen that the mixing is largely induced by the tensor force. The failure of realistic calculations in reproducing the inhibition may be related to its ill description of the monopole component rather than the tensor force.

  12. Metabolism and excretion of [14C] verruculogen in a sheep.

    Science.gov (United States)

    Perera, K P; Mantle, P G; Penny, R H

    1982-05-01

    [14C] Verruculogen (75 micrograms/kg) was given intravenously to a sheep under barbiturate anaesthesia to prevent the severe tremor and convulsions which would otherwise have occurred. Two hours later 28 per cent of the tremorgenic mycotoxin was detected in the liver, bile and small intestine. Approximately 0.5 per cent was excreted in the urine. Trace amounts of radiolabel were detected in the cortex and corpus striatum of the brain. Verruculogen was metabolised by the liver and converted completely to four more polar products, including two isomeric forms of desoxy-verruculogen and the weakly tremorgenic mycotoxin TR-2. The principal and most polar metabolite excreted is probably an isomer of TR-2.

  13. Redistribution of paclobutrazol-14C in soil and plant

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Maria Aparecida; Tornisielo, Valdemar Luiz; Regitano, Jussara Borges [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Ecotoxicologia]. E-mail: macosta@cena.usp.br; vltorrnis@cena.usp.br; regitano@cena.usp.br

    2007-07-01

    Paclobutrazol (PBZ) is important to the mango culture since it works as a growth regulator that inhibits gibberellins synthesis controlling the growth of the trees and thus reducing pruning and manipulation during cultivation. Although PBZ has been used for years in mango in Brazil, there are no studies evaluating its environmental fate under Brazilian conditions. Therefore, the objective of the present work is to evaluate the redistribution of PBZ and its metabolites in soil and plant. For this experiment, radiolabeled ({sup 14}C-PBZ) was used once this technique allows detention of minimum amounts of residues in both soil and plant. In addition, plants were cultivated in vessels (100 L and 1 plant /vessel) and the PBZ were applied to the soils at the recommended rate of 1,0 kg ha{sup -1}, having radioactive concentration of 2,0 MBq/vessel. In order to evaluate PBZ redistribution, the volumes of water percolated with rainfall and senescent leaves were collected to monitor their {sup 14}C-residue concentration by liquid scintillation spectrometry (LSS). In parallel, the sorption and leaching potential of PBZ was determined in order to support the previous study. The results showed that PBZ presented relatively low mobility (0.12 % of the applied amount) and high sorption (91.9 % of the applied amount) in the studied soil, being minimal its leached amount; and that majority of the soil applied radioactivity were redistributed in the plant leaves (1.08% of the applied amount). Needing more inquiries in relation to the contamination of the soil and rain water percolated in period of September, 2nd, 2006 to January, 8th, 2007 was of the 0.06% in relation applied radioactivity being very next the radioactivity to deep, indicating that the product still is not being leached during rains. (author)

  14. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    Science.gov (United States)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  15. Accelerator mass spectrometry analysis of {sup 14}C-oxaliplatin concentrations in biological samples and {sup 14}C contents in biological samples and antineoplastic agents

    Energy Technology Data Exchange (ETDEWEB)

    Toyoguchi, Teiko, E-mail: tteiko@med.id.yamagata-u.ac.jp [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kato, Kazuhiro; Tokanai, Fuyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the {sup 14}C concentration in {sup 14}C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of {sup 14}C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a {sup 14}C content of water in three vacuum blood collection tubes and a syringe were measured. {sup 14}C was not detected from water in these devices. The mean {sup 14}C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of {sup 14}C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, {sup 14}C contents of the antineoplastic agents were quantitated. {sup 14}C contents were different among 10 antineoplastic agents; {sup 14}C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  16. Estimation of radiation dosage and transmutation effect of 14-C involved in measuring rate of albumin synthesis with 14-C-carbonate.

    Science.gov (United States)

    Yap, S H; Hafkenscheid, J C; Goossens, C M; Buys, W C; Binkhorst, R A; van Tongeren, J H

    1975-07-01

    For direct measurement of the rate of albumin synthesis Na2 14CO3 was used intravenously. The assessment of the radiation hazard involved in the study was based on the knowledge of the minimum dose of Na214CO3 necessary for a sufficient incorporation of 14C in the guanidine-C of arginine in albumin to obtain measurable radioactivity. By measurement of expired 14CO2 and excreted 14C-urea in the urine during a 5-hr period following intravenous administration of Na214CO3 in five subjects, some quantitative data on 14C retention and radiation dosage were obtained. In comparison with animal studies, the rate of expiration of 14CO2 in man is slower. About 50% of the total radioactivity injected was lost through the respiratory route in the first hour. The total amount of expired 14C during the 5 hr of investigation was about 75% of the injected dose for the five subjects. The amount of 14C excreted as urinary 14C-urea during the 5 hr of investigation is very small in comparison with the expired 14C; it was only about 0.5% of the dose injected. The total absorbed radiation dose after complete elimination of 14C from the body was calculated with various assumptions. The extra risk of genetic damage due to disintegration of retained 14C in comparison with that of natural 14C in the body during 30 living years is about 50%.

  17. Radiocarbon content of pre-bomb marine mollusks and variations in the 14C Reservoir age for coastal areas of the Barents and Kara Seas, Russia

    Science.gov (United States)

    Forman, Steven L.; Polyak, Leonid

    Fourteen mollusks, collected alive between 1900 and 1945 from the Russian Barents and Kara seas, were analyzed by AMS 14C dating to evaluate variations in the 14C marine reservoir for arctic coastal sites, which is important for correcting ages in paleoenvironmental time-series and advancing understanding of the exchange of carbon. The 14C ages on the mollusks reveal a range of marine reservoir values (R(t)) from 159 14C yr to 764 14C yr. The oldest R(t) values of 764 to 620 14C yr are for the bivalve Portlandia arctica, which often inhabit cold and low salinity waters and muddy substrates. The depleted 14C content for this bivalve reflects possibly the incorporation of old carbon from freshwater inputs and/or the consumption of old organic matter from the underlying sediments and pore waters. Other mollusks with sessile habitats and pelagic food sources gave significantly lower R(t) values between 159 and 344 14C yr. The youngest R(t) values indicate enrichment in 14C and may partially reflect enhanced transfer of 14C-enriched CO2 from the atmosphere to the ocean surface with wind-generated wave agitation. This study underscores that a variety of processes can lead to variable 14C depletion and enrichment of surface waters yielding a ca. 600 year age span for contemporaneous arctic mollusks. There may be added uncertainty in the 14C reservoir correction for deposit-feeder species such as Portlandia sp. and perhaps for certain benthic foraminifera (e.g. Nonion labradoricum) because these taxa often incorporate old organic matter from the substrate. A reservoir correction of ≥700 years may be more appropriate for infaunal, deposit-eater species, particularly in glacier-dominated environments. Mollusks and foraminifera with sessile habits and pelagic food sources should be selected preferentially for 14C dating, because their shells may more closely reflect the 14C content of the global-ocean mixed layer.

  18. Metabolic fate of the (14)C-labeled herbicide clodinafop-propargyl in a sediment-water system.

    Science.gov (United States)

    Yuan, Ye; Weitzel, Pascal; Schäffer, Andreas; Schmidt, Burkhard

    2015-01-01

    The metabolic fate of (14)C-phenyl-labeled herbicide clodinafop-propargyl ((14)C-CfP) was studied for 28 days in lab assays using a sediment-water system derived from a German location. Mineralization was 5.21% of applied (14)C after 28 days exhibiting a distinct lag phase until day 14 of incubation. Portions of radioactivity remaining in water phases decreased at moderate rate to 18.48% after 28 days; 62.46% were still detected in water after 14 days. Soxhlet extraction of the sediment using acetonitrile released 35.56% of applied (14)C with day 28, while 33.99% remained as non-extractable residues. A remarkable increase of bound (14)C was observed between 14 and 28 days correlating with the distinct increase of mineralization. No correlation was found throughout incubation with microbial activity of the sediment as determined by dimethyl sulfoxide reduction. Dissolved oxygen and pH value of water phases remained almost constant for 28 days. Analyses of Soxhlet extracts of the sediment and ethyl acetate extracts of water phases by radio-TLC and radio-HPLC revealed that CfP was rapidly cleaved to free acid clodinafop (Cf), which was further (bio-) transformed. DT50 values (based on radio-HPLC) were below 1 day (CfP) and slightly above 28 days (Cf). Further metabolites were not detected. Fractionation of humic and non-humic components of the sediment demonstrated that CfP's non-extractable residues were predominantly associated with fulvic acids up to 14 days of incubation (3.36%), whereas after 28 days, the majority of radioactivity was found in the humin/mineral fraction (13.30% of applied (14)C). Due to high-performance size-exclusion chromatography of the fulvic acids fraction derived from assays incubated for 28 days, this portion of (14)C was firmly, possibly covalently bound to fulvic acids and did not consist of CfP or Cf. Using an isolation strategy comprising preincubation of sediment with CfP and mineralization of (14)C-CfP as criterion, a microorganism

  19. New measurement of exotic decay of $^{225}$Ac by $^{14}$C emission

    CERN Document Server

    Guglielmetti, A; Ardisson, G; Barci, V; Giles, T; Hussonnois, M; Le Dû, J F; Le Naour, C; Mikheev, V L; Pasinetti, A L; Ravn, H L; Tretyakova, S P; Trubert, D

    2001-01-01

    The branching ratio of $^{225}$Ac decay by emission of $^{14}$C was remeasured under improved experimental conditions by using a radioactive source produced at the ISOLDE mass-separator at CERN and a nuclear track detector technique. The result, B=$\\lambda_{^{14}\\textrm{C}} / \\lambda_{\\alpha} = (4.5 \\pm 1.4) 10^{-12}$, is consistent with the anomalously high value obtained in the 1993 experiment thus confirming the importance of nuclear structure effects in this exotic decay.

  20. Metabolic fate of the (14)C-labeled herbicide clodinafop-propargyl in soil.

    Science.gov (United States)

    Jaquet, Jasmin; Weitzel, Pascal; Junge, Thorsten; Schmidt, Burkhard

    2014-01-01

    The metabolic fate of (14)C-phenyl-labeled herbicide clodinafop-propargyl (CfP) was studied for 28 days in lab assays using a soil from Germany (Ap horizon, silt loam, and cambisol). Mineralization amounted to 12.40% of applied (14)C after 28 days showing a distinct lag phase until day 7 of incubation. Portions of radioactivity extractable by means of 0.01 M CaCl2 solution (bioavailable fraction) decreased rapidly and were 4.41% after 28 days. Even immediately after application, only 57.31% were extracted with the aqueous solvent. Subsequent extraction using accelerated solvent extraction (ASE; acetonitrile/water 4:1, v/v) released 39.91% of applied (14)C with day 0 and 26.16% with day 28 of incubation from the samples. Non-extractable portions of radioactivity thus, increased with time amounting to 11.99% (day 0) and 65.00% (day 28). A remarkable increase was observed between 14 and 28 days correlating with the distinct increase of mineralization. No correlation was found throughout incubation with general microbial activity as determined by DMSO reduction. Analysis of the CaCl2 and ASE extracts by radio-TLC, radio-HPLC and GC/MS revealed that CfP was rapidly cleaved to free acid clodinafop (Cf), which was further (bio-) transformed; DT50 values (based on radio-TLC detection of the parent compound) were far below 1 day (CfP) and about 7 days (Cf). TLC analysis pointed to 2-(4-hydroxyphenoxy)-propionic acid as further metabolite. Due to fractionation of non-extractable residues, most of the (14)C was associated with fulvic and humic acids, portions in humin fractions and non-humics were moderate and low, respectively. Using a special strategy, which included pre-incubation of the soil with CfP and then mineralization of (14)C-CfP as criterion, a microorganism was isolated from the soil examined. The microorganism grew using CfP as sole carbon source with concomitant evolution of (14)CO2. The bacterium was characterized by growth on commonly used carbon

  1. Progress report on a novel in situ{sup 14}C extraction scheme at the University of Cologne

    Energy Technology Data Exchange (ETDEWEB)

    Fülöp, R.-H. [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany); School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522 (Australia); Wacker, L. [Ion Beam Physics, ETH Zürich, 8093 Zürich (Switzerland); Dunai, T.J., E-mail: tdunai@uni-koeln.de [Institute of Geology and Mineralogy, University of Cologne, 50674 Cologne (Germany)

    2015-10-15

    We present initial results of in situ{sup 14}C system blank and calibration sample measurements obtained using the in situ{sup 14}C extraction scheme developed at the University of Cologne. The {sup 14}C extraction scheme specifically exploits the phase transformation of quartz to cristobalite in order to quantitatively extract the carbon as CO{sub 2} and follows a scheme that is different to that of existing extraction systems. Features are offline furnace extraction, single pass catalytic oxidation using mixed copper (I,II) oxide as catalyst, the use of UHV-compatible components and of vacuum annealed copper tubing. The design allows a relatively rapid sample throughput – two samples per day as opposed to the current 2 days per sample that can be done on other lines – and can accommodate samples ranging between 0.5 and 4 g of clean quartz. Following extraction and cleaning, the CO{sub 2} gas is measured using the gas ion source of the MICADAS AMS facility at ETH Zurich. The extraction system yields low systems blanks (10 {sup +16}/{sub −10} × 10{sup 3} atoms {sup 14}C, ±1 σ) and the initial results indicate that further improvements are achievable. Measurements of the CRONUS-A standard sample show a good reproducibility and results are consistent with published values. We also present the first in situ{sup 14}C results for the CRONUS-R standard material.

  2. Stable isotope deltas: Tiny, yet robust signatures in nature

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.

    2012-01-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg

  3. Stable isotope deltas: tiny, yet robust signatures in nature.

    Science.gov (United States)

    Brand, Willi A; Coplen, Tyler B

    2012-09-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including (14)C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. (13)C, (2)H, and (18)O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as-25 per mil can be written as-25 mUr (or-2.5 cUr or-0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg 'units' are easily included (e.g. either+0.015 ‰ or+15 per meg

  4. {sup 14}C determination in different bio-based products

    Energy Technology Data Exchange (ETDEWEB)

    Santos Arévalo, Francisco-Javier, E-mail: fj.santos@csic.es [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); Gómez Martínez, Isabel; Agulló García, Lidia; Reina Maldonado, María-Teresa [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); García León, Manuel [Centro Nacional de Aceleradores (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Junta de Andalucía), Thomas Alva Edison 7, 41092 Seville (Spain); Dpto. de Física Atómica Molecular y Nuclear, Universidad de Sevilla, Reina Mercedes s/n, 41012 Seville (Spain)

    2015-10-15

    Radiocarbon determination can be used as a tool to investigate the presence of biological elements in different bio-based products, such as biodiesel blends. These products may also be produced from fossil materials obtaining the same final molecules, so that composition is chemically indistinguishable. The amount of radiocarbon in these products can reveal how much of these biological elements have been used, usually mixed with petrol derived components, free of {sup 14}C. Some of these products are liquid and thus the handling at the laboratory is not as straightforward as with solid samples. At Centro Nacional de Aceleradores (CNA) we have tested the viability of these samples using a graphitization system coupled to an elemental analyzer used for combustion of the samples, thus avoiding any vacuum process. Samples do not follow any chemical pre-treatment procedure and are directly graphitized. Specific equipment for liquid samples related to the elemental analyzer was tested. Measurement of samples was performed by low-energy AMS at the 1 MV HVEE facility at CNA, paying special attention to background limits and reproducibility during sample preparation.

  5. The 14C-AMS Laboratory at IF-UFF

    Energy Technology Data Exchange (ETDEWEB)

    Macario, K.D.; Gomes, P.R.S.; Anjos, R.M.; Linares, R.; Carvalho, C.R.A.; Castro, M.D.; Oliveira, F.M.; Alves, E.Q.; Chanca, I.S. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-07-01

    Full text: In 2009 a radiocarbon sample preparation laboratory dedicated to Accelerator Mass Spectrometry was installed at the Physics Institute of the Fluminense Federal University. At the Radiocarbon Laboratory samples of several kinds of materials such as charcoal, sediments, wood and shells go through specific chemical treatment and conversion to carbon dioxide. Graphite reduction is performed in sealed Pyrex tubes, using Zinc, Titanium Hydrate, and iron catalyst within an inner tube. Samples have been successfully produced yielding fluffy homogeneous graphite leading to high and stable currents in the ion source. For sample measurement an accelerator system produced by the National Electrostatics Corporation (NEC), was installed in the Physics Institute. The machine, specially developed to carbon analysis, is the State of the Art in 14C - AMS studies and its acquisition represent a very important step for Brazil towards the development of science and technology regarding radiocarbon studies. The system includes an open air deck 250 kV single stage electrostatic accelerator with magnetic and electrostatic analyzers that enable isotope separation and detection. Radiocarbon concentrations are measured to 1 part in 10{sup 15} with precision of 0.3 The Nuclear Applied Physics group on Chronological Studies is now performing multidisciplinary research in collaboration with Brazilian and foreign groups from several fields of science such as Archaeology, Geophysics, Oceanography and Biology, in studies on the evolution of marine, terrestrial and Antarctic ecosystems. (author)

  6. A high resolution method for {sup 14}C analysis of a coral from South China Sea: Implication for “AD 775” {sup 14}C event

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Ping [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Shen, Chengde, E-mail: cdshen@gig.ac.cn [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing (China); Yi, Weixi; Wang, Ning [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Ding, Xingfang; Liu, Kexin; Fu, Dongpo [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 Beijing (China); Liu, Weiguo [State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, 710075 Xi’an (China); Liu, Yi [CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, 230026 Hefei (China)

    2015-10-15

    A pre-heating method that improves the background and precision of {sup 14}C dating significantly was applied for fossil coral dating with high resolution in our lab in Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS). The reaction tube is heated under 300 °C in a vacuum line before it is used for graphitization. The method can reduce the contamination absorbed in TiH{sub 2}, Zn and Fe power placed in the graphitization tube. With the pre-heating and average drilling method, bi-weekly resolution {sup 14}C dating in a fossil coral is carried out to investigate the “AD 775 {sup 14}C spike event”. Different from the tree ring {sup 14}C archives with the {sup 14}C spike of ∼15‰ (Δ{sup 14}C), the {sup 14}C spike in the coral shows an abrupt peak of 45‰ and two smaller spikes of Δ{sup 14}C > 20‰ in half a year in AD 776. And then, the {sup 14}C content in coral decreases gradually in AD 777. The peak time of the {sup 14}C spike event likely occurs in the summer of AD 776 according to the δ{sup 18}O variation in coral. High-resolution dating of {sup 14}C in coral provides not only a more detail process of the event than that from tree rings, but also the first report of the event from sea ecosystem. Both of them suggest an extraterrestrial origin of the event cause.

  7. Disposition of 14C-α-cyclodextrin in germ-free and conventional rats

    NARCIS (Netherlands)

    Ommen, B. van; Bie, A.T.H.J. de; Bär, A.

    2004-01-01

    The absorption, disposition, metabolism, and excretion of uniformly 14C-labeled α-cyclodextrin (14C-α-CD) was examined in four separate experiments with Wistar rats. In Experiment 1, 14C-α-CD (25μCi, 50mg/kg bw) was administered intravenously to four male and four female conventional rats. In Experi

  8. Technical Research on 14C Production by Irradiation of High Purity Alumium Nitride in CARR

    Institute of Scientific and Technical Information of China (English)

    DING; Li; DAI; Long-wen; LUO; Bei-bei; FU; Xin-hua; DOU; Qin-ming; ZHOU; Chang-bao

    2013-01-01

    14C is a pureβradioisotope,compounds labeled with 14C are utilized in radioactive tracer detection field.As tracer nuclear,14C is widely used in agriculture,industry,medicine,biological sciences etc.At present,the international market demand shows an obvious upward trendency,but our domestic market supply entirely14

  9. Synthesis of two sup 14 C-labeled catechol-o-methyltransferase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Carita; Honkanen, Erkki (Orion Corporation Ltd., Espoo (Finland). Research Center)

    1991-02-01

    {sup 14}C-labelled 3-(3,4-dihydroxy-5-nitrophenylmethylidene)-2,4-pentanedione and {sup 14}C-labelled E-N,N-diethyl-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)acrylamide have been synthesized from (carbonyl-{sup 14}C)vanillin. (author).

  10. {sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

    1999-03-01

    The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  11. Identification of Biodegradation Pathways in a Multi-Process Phytoremediation System (MPPS) Using Natural Abundance 14C Analysis of PLFA

    Science.gov (United States)

    Cowie, B. R.; Greenberg, B. M.; Slater, G. F.

    2008-12-01

    Optimizing remediation of petroleum-contaminated soils requires thorough understanding of the mechanisms and pathways involved in a proposed remediation system. In many engineered and natural attenuation systems, multiple degradation pathways may contribute to observed contaminant mass losses. In this study, biodegradation in the soil microbial community was identified as a major pathway for petroleum hydrocarbon removal in a Multi-Process Phytoremediation System (MPPS) using natural abundance 14C analysis of Phospholipid Fatty Acids (PLFA). In contaminated soils, PLFA were depleted in Δ14C to less than -800‰, directly demonstrating microbial uptake and utilization of petroleum derived carbon (Δ14C = -992‰) during bioremediation. Mass balance indicated that more than 80% of microbial carbon was derived from petroleum hydrocarbons and a maximum of 20% was produced from metabolism of modern carbon sources. In contrast, in a nearby uncontaminated control soil, the microbial community maintained a nearly modern 14C signature, suggesting preferential degradation of more labile, recent carbon. Mass balance using δ13C and Δ14C of soil CO2 demonstrated that mineralization of petroleum carbon contributed 60-65% of soil CO2 at the contaminated site. The remainder was derived from atmospheric (27-30%) and decomposition of non- petroleum natural organic carbon (5-10%). The clean control exhibited substantially lower CO2 concentrations that were derived from atmospheric (55%) and natural organic carbon (45%) sources. This study highlights the value of using multiple carbon isotopes to identify degradation pathways in petroleum- contaminated soils undergoing phytoremediation and the power of natural abundance 14C to detect petroleum metabolism in natural microbial communities.

  12. Water-solvent partition coefficients and Delta Log P values as predictors for blood-brain distribution; application of the Akaike information criterion.

    Science.gov (United States)

    Abraham, Michael H; Acree, William E; Leo, Albert J; Hoekman, David; Cavanaugh, Joseph E

    2010-05-01

    It is shown that log P values for water-alkane or water-cyclohexane partitions, and the corresponding Delta log P values when used as descriptors for blood-brain distribution, as log BB, yield equations with very poor correlation coefficients but very good standard deviations, S from 0.25 to 0.33 log units. Using quite large data sets, we have verified that similar S-values apply to predictions of log BB. A suggested model, based on log P for water-dodecane and water-hexadecane partition coefficients, has 109 data points and a fitted S = 0.254 log units. It is essential to include in the model an indicator variable for volatile compounds, and an indicator variable for drugs that contain the carboxylic group. A similar equation based on water-chloroform partition coefficients has 83 data points and a fitted S = 0.287 log units. We can find no causal connection between these log P values and log BB in terms of correlation or in terms of chemical similarity, but conclude that the log P descriptor will yield excellent predictions of log BB provided that predictions are within the chemical space of the compounds used to set up the model. We also show that model based on log P(octanol) and an Abraham descriptor provides a simple and easy method of predicting log BB with an error of no more than 0.31 log units. We have used the Akaike information criterion to investigate the most economic models for log BB.

  13. Source apportionment of carbonaceous aerosol in Sao Paulo using 13C and 14C measurements

    Science.gov (United States)

    Oyama, Beatriz; Andrade, Maria de Fatima; Holzinger, Rupert; Röckmann, Thomas; Meijer, Harro A. J.; Dusek, Ulrike

    2016-04-01

    The Metropolitan Area of Sao Paulo is affected by high aerosol concentrations, which contain a large fraction of organic material. Up to date, not much is known about the composition and origin of the organic aerosol in this city. We present the first source apportionment of the carbonaceous aerosol fraction in Sao Paulo, using stable (13C) and radioactive carbon isotopes (14C). 14C provides a clear-cut distinction between fossil sources, which contain no 14C, and contemporary sources such as biofuels, biomass burning, or biogenic sources, which contain a typical contemporary 14C/12C ratio. 13C can be used to distinguish C3 plants, such as maize and sugarcane, from C4 plants. This can help to identify a possible impact of sugarcane field burning in the rural areas of Sao Paulo State on the aerosol carbon in the city. In the first part of the study, we compare two tunnel studies: Tunnel 1 is frequented only by light duty vehicles, which run mainly on mixtures of gasoline with ethanol (gasohol, 25% ethanol and 85% gasoline) or hydrated ethanol (5% water and 95% ethanol). Tunnel 2 contains a significant fraction of heavy-duty diesel vehicles, and therefore the fraction of biofuels in the average fleet is lower. Comparison of 14C in organic and elemental carbon (OC and EC) shows that in both tunnels there is no significant contribution of biofuels to EC. Combusting ethanol-gasoline fuels in a vehicle engine does apparently not result in significant EC formation from ethanol. Biofuels contribute around 45% to OC in Tunnel 1 an only 20% in Tunnel 2, reflecting a strong impact of diesel vehicles in Tunnel 2. In the second part of the study we conduct a source apportionment of ambient aerosol carbon collected in a field study during winter (July-August) 2012. Ambient EC has two main sources, vehicular emissions and biomass burning. We estimate a contribution of vehicular sources to EC of roughly 90% during weekdays and 80% during weekends, using the 14C values measured in

  14. Preparation, Characterization, and Microbial Degradation of Specifically Radiolabeled [14C]Lignocelluloses from Marine and Freshwater Macrophytes †

    OpenAIRE

    1984-01-01

    Specifically radiolabeled [14C-lignin]lignocelluloses were prepared from the aquatic macrophytes Spartina alterniflora, Juncus roemerianus, Rhizophora mangle, and Carex walteriana by using [14C]phenylalanine, [14C]tyrosine, and [14C]cinnamic acid as precursors. Specifically radiolabeled [14C-polysaccharide]lignocelluloses were prepared by using [14C]glucose as precursor. The rates of microbial degradation varied among [14C-lignin]lignocelluloses labeled with different lignin precursors within...

  15. Analysis of 14C and 13C in teeth provides precise birth dating and clues to geographical origin

    Science.gov (United States)

    K, Alkass; BA, Buchholz; H, Druid; KL, Spalding

    2011-01-01

    The identification of human bodies in situations when there are no clues as to the person’s identity from circumstantial data, poses a difficult problem to investigators. The determination of age and sex of the body can be crucial in order to limit the search to individuals that are a possible match. We analyzed the proportion of bomb pulse derived carbon-14 (14C) incorporated in the enamel of teeth from individuals from different geographical locations. The ‘bomb pulse’ refers to a significant increase in 14C levels in the atmosphere caused by above ground test detonations of nuclear weapons during the cold war (1955-1963). By comparing 14C levels in enamel with 14C atmospheric levels systematically recorded over time, high precision birth dating of modern biological material is possible. Above ground nuclear bomb testing was largely restricted to a couple of locations in the northern hemisphere, producing differences in atmospheric 14C levels at various geographical regions, particularly in the early phase. Therefore, we examined the precision of 14C birth dating of enamel as a function of time of formation and geographical location. We also investigated the use of the stable isotope 13C as an indicator of geographical origin of an individual. Dental enamel was isolated from 95 teeth extracted from 84 individuals to study the precision of the 14C method along the bomb spike. For teeth formed before 1955 (N = 17), all but one tooth showed negative Δ14C values. Analysis of enamel from teeth formed during the rising part of the bomb-spike (1955-1963, N = 12) and after the peak (>1963, N = 66) resulted in an average absolute date of birth estimation error of 1.9 ±1.4 and 1.3 ± 1.0 years, respectively. Geographical location of an individual had no adverse effect on the precision of year of birth estimation using radiocarbon dating. In 46 teeth, measurement of 13C was also performed. Scandinavian teeth showed a substantially greater depression in average δ13C

  16. Authentication of Chinese vintage liquors using bomb-pulse 14C

    Science.gov (United States)

    Cheng, Peng; Zhou, Weijian; Burr, G. S.; Fu, Yunchong; Fan, Yukun; Wu, Shugang

    2016-12-01

    The older a bottle of Chinese vintage liquor is, the higher the price it commands. Driven by the potential for higher profits, some newly-founded distilleries openly sell liquor whose storage ages are exaggerated. In China, the market for vintage liquor has become fraught with uncertainty and a pressing need has arisen to establish an effective method to authenticate the age of vintage liquors. A radiocarbon (14C) dating method is described here that can verify cellar-stored years of Chinese liquors distilled within the last fifty years. Two different flavored Chinese liquors produced in “the golden triangular region” in the Upper Yangtze River region in southwest China, with known cellar-stored years, were analyzed to benchmark the technique. Strong flavored liquors are found to be consistent with local atmospheric Δ14C values. A small offset of 2-3 years between predicted vintage years of soy-sauce flavored liquors and strong flavored liquors is found to be associated with the fermentation cycle of certain varieties. The technique can measure cellar-stored years of a wide range of liquors including those with fundamentally different aromas. This demonstrates the strength of our method in identifying suspect Chinese vintage liquors.

  17. Impact of carbon nanomaterials on the behaviour of {sup 14}C-phenanthrene and {sup 14}C-benzo-[a] pyrene in soil

    Energy Technology Data Exchange (ETDEWEB)

    Towell, Marcie G.; Browne, Lesley A. [Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ (United Kingdom); Paton, Graeme I. [Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Semple, Kirk T., E-mail: k.semple@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ (United Kingdom)

    2011-03-15

    The impact of fullerene soot (FS), single-walled (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes on the behaviour of two {sup 14}C-PAHs in sterile soil was investigated. Different concentrations of carbon nanomaterials (0, 0.05, 0.1 and 0.5%) were added to soil, and {sup 14}C-phenanthrene and {sup 14}C-benzo[a]pyrene extractability assessed over 80 d through dichloromethane (DCM) and hydroxypropyl-{beta}-cyclodextrin (HPCD) shake extractions. Total {sup 14}C-PAH activity in soils was determined by combustion, and mineralisation of {sup 14}C-phenanthrene was monitored over 14 d, using a catabolically active pseudomonad inoculum. No significant loss of {sup 14}C-PAH-associated activity from CNM-amended soils was observed over the 'aging' period. CNMs had a significant impact on HPCD-extractability of {sup 14}C-PAHS; extractability decreased with increasing CNM concentration. Additionally, {sup 14}C-phenanthrene mineralisation was inhibited by the presence of CNMs at concentrations of {>=}0.05%. Differences in overall extents of {sup 14}C-mineralisation were also apparent between CNM types. It is suggested the addition of CNMs to soil can reduce PAH extractability and bioaccessibility, with PAH sorption to CNMs influenced by CNM type and concentration. - Research highlights: > Carbon nanoparticles reduce the extractability of PAHs in soil. > Carbon nanoparticles reduce the bioaccessibility of PAHs in soil. > Nanoparticle type is important in controlling the behaviour of PAHs in soil. > Nanoparticle concentration is important in controlling the behaviour of PAHs in soil - Carbon nanomaterials (CNMs) can alter the extractability, bioaccessibility and microbial mineralisation of PAHs in soil.

  18. Observational $\\Delta\

    CERN Document Server

    Hernández, Antonio García; Monteiro, Mário J P F G; Suárez, Juan Carlos; Reese, Daniel R; Pascual-Granado, Javier; Garrido, Rafael

    2015-01-01

    Delta Scuti ($\\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\\delta$ Sct stars.

  19. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Science.gov (United States)

    Foufoula-Georgiou, E.

    2013-12-01

    Deltas are economic and environmental hotspots, food baskets for many nations, home to a large part of the world population, and hosts of exceptional biodiversity and rich ecosystems. Deltas, being at the land-water interface, are international, regional, and local transport hubs, thus providing the basis for intense economic activities. Yet, deltas are deteriorating at an alarming rate as 'victims' of human actions (e.g. water and sediment reduction due to upstream basin development), climatic impacts (e.g. sea level rise and flooding from rivers and intense tropical storms), and local exploration (e.g. sand or aggregates, groundwater and hydrocarbon extraction). Although many efforts exist on individual deltas around the world, a comprehensive global delta sustainability initiative that promotes awareness, science integration, data and knowledge sharing, and development of decision support tools for an effective dialogue between scientists, managers and policy makers is lacking. Recently, the international scientific community proposed to establish the International Year of Deltas (IYD) to serve as the beginning of such a Global Delta Sustainability Initiative. The IYD was proposed as a year to: (1) increase awareness and attention to the value and vulnerability of deltas worldwide; (2) promote and enhance international and regional cooperation at the scientific, policy, and stakeholder level; and (3) serve as a launching pad for a 10-year committed effort to understand deltas as complex socio-ecological systems and ensure preparedness in protecting and restoring them in a rapidly changing environment. In this talk, the vision for such an international coordinated effort on delta sustainability will be presented as developed by a large number of international experts and recently funded through the Belmont Forum International Opportunities Fund. Participating countries include: U.S., France, Germany, U.K., India, Japan, Netherlands, Norway, Brazil, Bangladesh

  20. A new 14C calibration data set for the last deglaciation based on marine varves

    Energy Technology Data Exchange (ETDEWEB)

    Hughen, K A; Kashgarian, M; Lehman, S J; Overpeck, J T; Peterson, L C; Southon, J R

    1999-02-22

    Varved sediments of the tropical Cariaco basin provide a new {sup 14}C calibration data set for the period of deglaciation (10,000 to 14,500 years before present: 10-14.5 cal ka BP). Independent evaluations of the Cariasco Basin calendar and {sup 14}C chronologies were based on the agreement of varve ages with the GISP2 ice core layer chronology for similar high-resolution paleoclimate records, in addition to {sup 14}C age agreement with terrestrial {sup 14}C dates, even during large climatic changes. These assessments indicate that the Cariaco Basin {sup 14}C reservoir age remained stable throughout the Younger Dryas and late Alleroed climatic events and that the varve and {sup 14}C chronologies provide an accurate alternative to existing calibrations based on coral U/Th dates. The Cariaco Basin calibration generally agrees with coral-derived calibrations but is more continuous and resolves century-scale details of {sup 14}C change not seen in the coral records. {sup 14}C plateaus can be identified at 9.6, 11.4, and 11.7 {sup 14}C ka BP, in addition to a large, sloping plateau during the Younger Dryas ({approximately}10 to 11 {sup 14}C ka BP). Accounting for features such as these is crucial to determining the relative timing and rates of change during abrupt global climate changes of the last deglaciation.

  1. A new 14C calibration data set for the last deglaciation based on marine varves

    Energy Technology Data Exchange (ETDEWEB)

    Hughen, K A; Kashgarian, M; Lehman, S J; Overpeck, J T; Peterson, L C; Southon, J R

    1999-02-22

    Varved sediments of the tropical Cariaco basin provide a new {sup 14}C calibration data set for the period of deglaciation (10,000 to 14,500 years before present: 10-14.5 cal ka BP). Independent evaluations of the Cariasco Basin calendar and {sup 14}C chronologies were based on the agreement of varve ages with the GISP2 ice core layer chronology for similar high-resolution paleoclimate records, in addition to {sup 14}C age agreement with terrestrial {sup 14}C dates, even during large climatic changes. These assessments indicate that the Cariaco Basin {sup 14}C reservoir age remained stable throughout the Younger Dryas and late Alleroed climatic events and that the varve and {sup 14}C chronologies provide an accurate alternative to existing calibrations based on coral U/Th dates. The Cariaco Basin calibration generally agrees with coral-derived calibrations but is more continuous and resolves century-scale details of {sup 14}C change not seen in the coral records. {sup 14}C plateaus can be identified at 9.6, 11.4, and 11.7 {sup 14}C ka BP, in addition to a large, sloping plateau during the Younger Dryas ({approximately}10 to 11 {sup 14}C ka BP). Accounting for features such as these is crucial to determining the relative timing and rates of change during abrupt global climate changes of the last deglaciation.

  2. VALIDATION OF 14C-UREA BREATH TEST FOR DIAGNOSIS OF Helicobacter pylori Validação do teste expiratório com 14C-uréia para o diagnóstico do Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Rejane MATTAR

    1999-01-01

    Full Text Available The aim of this study was to validate the 14C-urea breath test for use in diagnosis of Helicobacter pylori infection. Thirty H. pylori positive patients, based on histologic test and thirty H. pylori negative patients by histology and anti-H. pylori IgG entered the study. Fasting patients drank 5 uCi of 14C-urea in 20 ml of water. Breath samples were collected at 0, 5, 10, 15, 20 and 30 min. The difference of cpm values between the two groups was significant at all the time intervals, besides time 0 (pO teste expiratório com 14C-uréia diagnostica infecção pelo Helicobacter pylori no estômago. A urease, produzida por esta bactéria, quebra a 14C-uréia, resultando em HCO3- e NH4+, sendo expirado 14CO2 pelos pulmões e quantificado, então, por contador Beta. O objetivo do nosso estudo foi validar o teste expiratório com 14C-uréia, determinando o tempo ideal de coleta da amostra e o valor de corte. Foi definido o tempo de 20 min para coleta do exame após a ingestão de 5 uCi de 14C-uréia com valor de corte de 562 cpm. A sensibilidade e a especificidade do teste foram de 100% aos 20 min. As diferenças de contagens entre os grupos Helicobacter pylori negativos e Helicobacter pylori positivos foram estatisticamente significativas (p<0,0001. As pacientes do sexo feminino, aos 20 min apresentaram contagens superiores às dos pacientes do sexo masculino (p=0,005. É preciso verificar se as mulheres têm maior densidade bacteriana, ou se é pelo fato dos homens expirarem mais CO2, diluindo a amostra. O teste expiratório com 14C-uréia é método diagnóstico não invasivo, muito sensível, específico e barato.

  3. {sup 14}C emission from Swedish nuclear power plants and its effect on the {sup 14}C levels in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Stenstroem, K.; Erlandsson, Bengt; Hellborg, R.; Kiisk, M.; Persson, Per [Lund Univ. (Sweden). Dept. of Nuclear Physics; Mattsson, Soeren; Thornberg, C. [Lund Univ., Malmoe (Sweden). Dept. of Radiation Physics; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

    2000-02-15

    The radionuclide {sup 14}C is produced in all types of nuclear reactors mainly by neutron induced reactions in oxygen ({sup 17}O), nitrogen ({sup 14}N) and carbon ({sup 13}C). Part of the {sup 14}C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO{sub 2}, CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of {sup 14}C, it is of interest to measure the releases and their incorporation into living material. The {sup 14}C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebaeck and Forsmark) as well as the background {sup 14}C activity levels from two reference sites in southern Sweden during 1973-1996 are presented in this report. In order to verify the reliability of the method some investigations have been conducted at two foreign nuclear sites, Sellafield fuel reprocessing plant in England, and Pickering nuclear generating station in Canada, where the releases of {sup 14}C are known to be substantial. Furthermore, results from some measurements in the vicinity of Paldiski submarine training centre in Estonia are presented. The results of the {sup 14}C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of {sup 14}C, if at all above the uncertainty of the measurements. Even if the accuracy of the measurements of the annual tree rings is rather good (1-2%) the contribution of {sup 14}C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of {sup 14}C . This is the case for all sampling procedures: in air and vegetation as well as in annual tree rings. Only on a few occasions an actual increase is observed. However, although the calculations suffer from rather large uncertainties, the calculated release rate from Barsebaeck is in fair agreement

  4. {sup 14}C emission from Swedish nuclear power plants and its effect on the {sup 14}C levels in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Stenstroem, K.; Erlandsson, Bengt; Hellborg, R.; Kiisk, M.; Persson, Per [Lund Univ. (Sweden). Dept. of Nuclear Physics; Mattsson, Soeren; Thornberg, C. [Lund Univ., Malmoe (Sweden). Dept. of Radiation Physics; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

    2000-02-15

    The radionuclide {sup 14}C is produced in all types of nuclear reactors mainly by neutron induced reactions in oxygen ({sup 17}O), nitrogen ({sup 14}N) and carbon ({sup 13}C). Part of the {sup 14}C created is continuously released during normal operation as airborne effluents in various chemical forms (such as CO{sub 2}, CO and hydrocarbons) to the surroundings. Because of the biological importance of carbon and the long physical half-life of {sup 14}C, it is of interest to measure the releases and their incorporation into living material. The {sup 14}C activity concentrations in annual tree rings and air around two Swedish nuclear power plants (Barsebaeck and Forsmark) as well as the background {sup 14}C activity levels from two reference sites in southern Sweden during 1973-1996 are presented in this report. In order to verify the reliability of the method some investigations have been conducted at two foreign nuclear sites, Sellafield fuel reprocessing plant in England, and Pickering nuclear generating station in Canada, where the releases of {sup 14}C are known to be substantial. Furthermore, results from some measurements in the vicinity of Paldiski submarine training centre in Estonia are presented. The results of the {sup 14}C measurements of air, vegetation and annual tree rings around the two Swedish nuclear power plants show very low enhancements of {sup 14}C, if at all above the uncertainty of the measurements. Even if the accuracy of the measurements of the annual tree rings is rather good (1-2%) the contribution of {sup 14}C from the reactors to the environment is so small that it is difficult to separate it from the prevailing background levels of {sup 14}C . This is the case for all sampling procedures: in air and vegetation as well as in annual tree rings. Only on a few occasions an actual increase is observed. However, although the calculations suffer from rather large uncertainties, the calculated release rate from Barsebaeck is in fair agreement

  5. Effect of dead carbon on the 14C dating of the speleothem

    Institute of Scientific and Technical Information of China (English)

    CAI Yanjun; Warren Beck; PENG Zicheng; ZHANG Zhaofeng

    2005-01-01

    Based on the comparison of dating results among high-precision TIMS U-series and AMS 14C as well as the published 14C dating results and their band counting ages (i.e. calendar ages), this paper discusses the effect of dead carbon on the speleothem 14C dating. The result shows that the fraction of incorporated dead carbon during the formation of speleothem varies. The change in the fraction of dead carbon would result in big deviation in the 14C age of the speleothem. It is indispensable to take the dead carbon into consideration when dating the speleothem using the 14C method or studying the atmospheric 14C concentration during the past with the speleothem.

  6. Synthesis of Dl-methionine carboxyl {sup 14}C and its enzymatic optical resolution into L-methionine carboxyl {sup 14}C; Synthese de la DL-methionine carboxyle {sup 14}C et sa resolution enzymatique en L-methionine carboxyle {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Guermont, J.P.; Sharefkin, D.; Pichat, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-03-01

    DL-methionine carboxyl {sup 14}C has been prepared by Strecker reaction from {sup 14}C N K and {beta}-methylmercapto-propionaldehyde with 61 per cent yield. The enzymatic resolution of N-acetyl DL-methionine gives rise to L-methionine carboxyl {sup 14}C with 78 per cent yield. (authors) [French] La DL-methionine carboxyle {sup 14}C a ete preparee par reaction de Strecker a partir de {sup 14}C N K et du {beta}-methylmercapto propionaldehyde avec un rendement de 61 pour cent. Par resolution enzymatique de l'acetyl-DL-methionine, la L-methonine carboxyde {sup 14}C a ete obtenue avec un rendement de 78 pour cent.

  7. [Oxidation of [1-14C]palmitoyl-CoA, [1-14C]acetyl-CoA and [2-14C]pyruvate in rabbit adrenal, liver and heart mitochondria under normal conditions and in acute stress].

    Science.gov (United States)

    Mandrik, K A; Doroshkevich, N A; Vinogradov, V V

    1986-01-01

    The acute immobilized stress was studied for its effect on oxidation rate of [1-14C]palmitoyl-CoA, [1-14C]acetyl-CoA and [2-14C]pyruvate in mitochondria of the adrenals, liver and heart of rabbits. The stress effect on the energy metabolism of adrenals is associated with an increase of the rate of CO2 formation from pyruvate and with a decrease of the rate of CO2 formation from palmitoyl-CoA. Intensified oxidation of all substrates is observed in the heart mitochondria. The processes of beta-oxidation are more active in the liver. The data obtained evidence for differences in the mechanisms of energy metabolism reconstruction under acute stress in tissues with different functional specialization.

  8. Seasonal variations of {sup 14}C and δ{sup 13}C for cave drip waters in Ryugashi Cave, Shizuoka Prefecture, central Japan

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo, E-mail: minami@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Kato, Tomomi [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 (Japan); Horikawa, Keiji [Department of Environmental Biology and Chemistry, Toyama University, Toyama 930-8555 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2015-11-01

    Speleothem {sup 14}C has recently emerged as a potentially powerful proxy for hydrology changes in comparison with atmospheric {sup 14}C calibration curve, rather than as a direct dating tool, apart from a time marker using bomb peak of {sup 14}C. Some possible causes for the relationship between speleothem {sup 14}C content (or dead carbon fraction: DCF) and karst hydrology have been proposed, such as changes in temperature, precipitation, drip water flow dynamics, cave air ventilation, soil air pCO{sub 2}. In this study, we investigated seasonal variation in {sup 14}C and δ{sup 13}C of drip water in Ryugashi Cave, Shizuoka Prefecture, central Japan, to examine the causes of the {sup 14}C and δ{sup 13}C variations in a speleothem. The results show that different {sup 14}C concentrations and δ{sup 13}C values of drip water from the Ryugashi Cave, were exhibited at different sites of the Caves No. 1, No. 3, and No. 4, which have different temperature, air pCO{sub 2}, and flow paths. Further, the {sup 14}C and δ{sup 13}C of drip waters showed seasonal variations at all sites, which were lower in fall and winter, and higher in spring and summer, though the extent of the variations was different among the sites. The {sup 14}C in drip waters tended to be correlated with the drip rates: {sup 14}C tended to be higher in drip waters with higher drip rates, and also correlated with rainfall amount around the Ryugashi Cave, especially for the drip waters in Cave No. 3, which are considered to have simpler flow paths. The increase in rainfall amount could bring the increase in drip rate of drip water, and then the decrease in interaction between solution and karst, resulting in {sup 14}C increase (DCF decrease) in drip water. Accordingly, the reconstruction of precipitation could be performed using {sup 14}C variation in a speleothem formed by drip water with simple flow dynamics.

  9. Synthesis of the muscle relaxant ( sup 14 C)L-637,510

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, S.P.; Ellsworth, R.L.; Gatto, G. (Merck Sharp and Dohme Research Labs., Rahway, NJ (United States))

    1991-07-01

    The synthesis of (E)-3-(9-chloro-5,6-dihydro-11H-pyrolo(2,1-b)(3)-benzazepin-11-ylidene)-N,N-dimethyl-1- (3-{sup 14}C)-propanamine (Z)-2-butenedioate(1:1) (({sup 14}C)L-637,510), a potential muscle relaxant product for which {sup 14}C-labeling was required for metabolism studies, is described. Introduction of the label in the 3-position of the propanamine side chain was accomplished in eight steps from sodium ({sup 14}C)cyanide with an overall radiochemical yield of 4.8%. (author).

  10. Straw 14C Decomposition and Distribution in Humus Fractions as Influenced by Soil Moisture Regimes

    Institute of Scientific and Technical Information of China (English)

    WANGZHIMING; ZHUPEILI; 等

    1999-01-01

    14C-tracer technique and closed incubation method were used to study straw 14C decomposition and distribution in different fractions of newly fromed humus under different moisture regimes.Decomposition of straw 14C was faster during the initial days,and slower thereafter,Decay rate constants of straw 14C varied from 3.29×10-3d-1 to 7.06×10-3 d-1,After 112d incubation,the amount of straw 14C mineralized was 1.17-1.46 times greater in submerged soils than in upland soils.Of the soil residual 14C,9.08%-15.75% was present in humic acid(HA) and 31.01%-37.62% in fulvic acid(FA).Submerged condition favored the formation of HA,and HA/FA ratio of newly formed humus(labelled)was greater in submerged soils than in upland soils.Clay minerals affected the distribution of straw 14C in different humus fractions.Proportion of 14C present in HA to 14C remaining in soil was greater in Vertisol than in Ultisol.

  11. Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

    Energy Technology Data Exchange (ETDEWEB)

    Porwoll, J.P.; Leete, E. (Minnesota Univ., Minneapolis (USA). Dept. of Chemistry)

    1985-03-01

    Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

  12. Surrogate gas prediction model as a proxy for Δ14C-based measurements of fossil fuel CO2

    Science.gov (United States)

    Coakley, Kevin J.; Miller, John B.; Montzka, Stephen A.; Sweeney, Colm; Miller, Ben R.

    2016-06-01

    The measured 14C:12C isotopic ratio of atmospheric CO2 (and its associated derived Δ14C value) is an ideal tracer for determination of the fossil fuel derived CO2 enhancement contributing to any atmospheric CO2 measurement (Cff). Given enough such measurements, independent top-down estimation of U.S. fossil fuel CO2 emissions should be possible. However, the number of Δ14C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ14C is therefore measured in just a small fraction of samples obtained by flask air sampling networks around the world. Here we develop a projection pursuit regression (PPR) model to predict Cff as a function of multiple surrogate gases acquired within the NOAA/Earth System Research Laboratory (ESRL) Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halocarbon and hydrocarbon acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 to 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ14C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of

  13. Surrogate gas prediction model as a proxy for Δ(14)C-based measurements of fossil fuel-CO2.

    Science.gov (United States)

    Coakley, Kevin J; Miller, John B; Montzka, Stephen A; Sweeney, Colm; Miller, Ben R

    2016-06-27

    The measured (14)C:(12)C isotopic ratio of atmospheric CO2 (and its associated derived Δ(14)C value) is an ideal tracer for determination of the fossil fuel derived CO2 enhancement contributing to any atmospheric CO2 measurement (Cff ). Given enough such measurements, independent top-down estimation of US fossil fuel-CO2 emissions should be possible. However, the number of Δ(14)C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ(14)C is therefore measured in just a small fraction of samples obtained by ask air sampling networks around the world. Here, we develop a Projection Pursuit Regression (PPR) model to predict Cff as a function of multiple surrogate gases acquired within the NOAA/ESRL Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halo- and hydrocarbons acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 through 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi-square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ(14)C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of uncertainties and

  14. Seasonal mercury concentrations and {delta}{sup 15}N and {delta}{sup 13}C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Jaramillo, Mauricio, E-mail: mdiazjaramillo@conicet.gov.ar [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Munoz, Claudia; Rudolph, Ignacio [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Servos, Mark [Department of Biology, University of Waterloo, ON (Canada); Barra, Ricardo [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile)

    2013-01-01

    The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes ({delta}{sup 15}N and {delta}{sup 13}C). Mercury concentrations in Lenga sediments ranged from 0.4 {+-} 0.1 to 13 {+-} 3 mg/kg, while those in Tubul sediments ranged from 0.02 {+-} 0.01 to 0.07 {+-} 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p < 0.05), but not by species or season for each estuary (p > 0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of {delta}{sup 13}C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources. -- Highlights: Black-Right-Pointing-Pointer Hg in sediments and biota from Lenga Estuary were elevated compared to nearby estuary. Black-Right-Pointing-Pointer Invertebrates showed interspecific and seasonal differences in terms of organic Hg %. Black-Right-Pointing-Pointer Total Hg levels in the ragworm best reflect Hg sediment gradient in Lenga Estuary. Black-Right-Pointing-Pointer Interspecific variation in {delta}{sup 13}C signatures indicated different feeding modes. Black

  15. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  16. Delta robot

    NARCIS (Netherlands)

    Herder, J.L.; Van der Wijk, V.

    2010-01-01

    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  17. Synthesis and distribution of N-benzyloxycarbonyl-[{sup 14}C]-glycine, a lipophilic derivative of glycine

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D.M.; Gallez, Bernard; Poupaert, J.H. [Universite Catholique de Louvain, Brussels (Belgium). Dept. des Sciences Pharmaceutiques

    1995-12-31

    N-benzyloxycarbonyl[{sup 14}C]-glycine, a lipophilic derivative of glycine exhibiting anticonvulsant properties, was prepared in one step from [U-{sup 14}C] glycine and benzyl chloroformate in alkali medium. a comparative study of biodistribution was carried on mice between this compound and the parent amino-acid after intravenous administration. Dimethylsulfoxide was used as injection vehicle for N-benzyloxycarbonylglycine. The influence of this injection vehicle was studied comparing glycine injected in a saline solution and glycine co-administered with dimethylsulfoxide. No significant difference was found between these two treatments. Compared to glycine, N-benzyloxycarbonylglycine reached quickly the central nervous system and exhibited an enhanced brain penetration index, 13-fold superior to the parent aminoacid value. (Author).

  18. Accelerator mass spectrometry with 14C and 10Be in utrecht

    NARCIS (Netherlands)

    Borg, K. van der; Alderliesten, C.; Houston, C.M.; Jong, A.F.M. de; Zwol, N.A. van

    1987-01-01

    The Utrecht facility for accelerator mass spectrometry is now in operation for routine measurements of 14C and 10Be in natural samples. Sample preparation techniques have been introduced. A 1% precision for 14C/12C ratios is routinely achieved. In the last year, more than 500 samples have been prepa

  19. 17 CFR 240.14c-4 - Presentation of information in information statement.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Presentation of information in... Section 14(c) § 240.14c-4 Presentation of information in information statement. (a) The information... type except that to the extent necessary for convenient presentation, financial statements and...

  20. Comparison of 14C and U-Th ages of two Holocene phreatic overgrowths on speleothems from Mallorca (Western Mediterranean: Environmental implications

    Directory of Open Access Journals (Sweden)

    Tuccimei Paola

    2011-01-01

    Full Text Available This investigation reports on the comparison between ICP-MS U-Th and AMS 14C ages of Phreatic Overgrowths on Speleothems (POS from two different caves on the island of Mallorca (Spain. These speleothem encrustations form at the water table of coastal caves in a low-amplitude tide-controlled microenvironment and are used to reconstruct past sea level changes. The aim of this study is to evaluate if this particular type of speleothem is datable using 14C method and to investigate possible problems connected with the incorporation of dead carbon inherited from the dissolution of 14C-free limestone. The results show that 14C ages are strongly site dependent and appear related to local residence time of water infiltration through the soil and epikarst. When short transit time and limited interaction with soil and bedrock, as in Cova de Cala Varques A, the so-called “reservoir” effect is negligible and 14C and U-Th ages corresponds within the error range. When the residence time is longer, as in Cova des Pas de Vallgornera, 14C ages are steadily 2,300-2,400 years older than the U-Th data, as shown by the mean value (25% of estimated percent dead carbon proportions and by higher and better correlated contents of major and trace elements in the vadose support of this speleothem encrustation. The potential use of this multi-method approach to paleoenvironmental studies is also suggested.

  1. Influence of increasing combustion temperature on the AMS 14C dating of modern crop phytoliths

    Science.gov (United States)

    Yin, Jinhui; Yang, Xue; Zheng, Yonggang

    2014-10-01

    Several attempts have been made to directly date phytoliths, but most 14C results are not consistent with other independent chronologies. Due to the limited dataset, there is not a clear explanation for these discrepancies. Herein, we report the 14C ages of phytolith-occluded carbon (PhytOC) from contemporary rice and millet crops that were combusted at different temperatures to investigate the relationship between the combustion temperature and resulting 14C age. Our results show that the 14C age of PhytOC increases directly with combustion temperature (up to 1100°C) and results in age overestimations of hundreds of years. Considerably older ages are observed at higher temperatures, suggesting that it may be possible to distinguish between two fractions of organic carbon in phytoliths: labile and recalcitrant carbon. These findings challenge the assumption that PhytOC is homogeneous, an assumption made by those who have previously attempted to directly date phytoliths using 14C.

  2. The release of 14C-chlorsulfuron bound residue by autoclavingmethod and its identification

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    When individual microorganisms were used torelease bound pesticide residues, it was ussually not take into fullaccountwhether the autoclaving method could lead to the releaseof bound residues. The soil containing bound14C-chlorsulfuron residues was treated with an autoclavein this study. The results reveal that the bound14C-chlorsulfuron residue can be released from the soilwhen treated with the autoclave and the release rate canbe remarkably enhanced by adding water into the soil whensubjected to such treatment. A TLC analysis showed that thereleased 14C-residue was one of the degraded products of14C-chlorsulfuron. After derivatization and analysis using theGC-MS, the released 14C-residue was tentatively identifiedas 2-amino-4-hydroxyl-6-methyl-1,3,5-triazine.

  3. Internal dosimetry for [4-{sup 14}C]-cholesterol in humans; Dosimetria interna para o [4-{sup 14}C]-colesterol em humanos

    Energy Technology Data Exchange (ETDEWEB)

    Marcato, Larissa Andreto

    2012-07-01

    The main objective of this work is to provide a biokinetic model in order to estimate the radiometric dose due to intake of [4-{sup 14}C]-cholesterol. The model was validated comparing the values of fecal excretion and absorption described in literature with that predicted by the model. The proposed model achieved good concordance between the results (p = 0.416 for excretion and p = 0.423 for absorption). The coefficients of effective dose (SvBq{sup -1}), equivalent dose (SvBq{sup -1}) and absorbed dose (GyBq{sup -1}) in human organs and tissues were calculated using the MIRD methodology and the compartmental analysis software ANACOMP. The coefficients were estimated for four phantoms: adult with a body mass of 73.3 kg, 15 years old adolescent (56.9 kg), 10 years old child (33.2 kg) and five years old child (19.8 kg). The organ that received the highest absorbed dose for all phantoms was the lower large intestine (LLI). The allometry theory was used to interpolate the coefficient of absorbed dose in the lower large intestine (DLLI) for unknown body mass (m): DLLI (GyBq{sup -1})=161.26 m (kg){sup -1.025}. For the same administered activity, the effective dose coefficient (E) decreases as the body mass increases. On other words, for the same intake activity, individuals with low body mass are exposed to higher doses. The allometry theory was used to interpolate the coefficient effective dose (E) for unknown body mass (m): E(SvB{sup -1})= 171.1 m(kg){sup -1,021}. (author)

  4. Oxidation of D-[U-(14)C] glucose and [1,12-(14)C] dodecanedioic acid by pancreatic islets from Goto-Kakizaki rats.

    Science.gov (United States)

    Malaisse, W J; Doherty, M; Ladrière, L; Greco, A V; Mingrone, G

    2001-08-01

    In pancreatic islets from hereditarily diabetic GK rats, [1,12 -(14)C] dodecanedioic acid (5.0 mM) was oxidized at a rate representing about 5 % of that of D-[U - (14)C] glucose (8.3 mM). Dioic acid and hexose failed to exert any significant reciprocal effects on their respective oxidation. The production of (14)CO(2) from [1,12 -(14)C] dodecanedioic acid was proportional to its concentration in the 0.2 - 5.0 mM range. These results were essentially comparable to those obtained in islets from control rats. They extend, therefore, to GK rats the knowledge that dodecanedioic acid acts as a nutrient in pancreatic islet cells.

  5. An approximate calculation of advective gas-phase transport of 14C at Yucca Mountain, Nevada

    Science.gov (United States)

    Knapp, R. B.

    1990-01-01

    A quasilinear partial differential equation, which describes gas-phase transport of a 14C kinematic wave through a porous medium, is derived, its sensitivity to system variables is analyzed and it is applied to one possible release scenarion at the porposed Yucca Mountain, Nevada high-level radioactive waste repository. Advection, isotope exchange between CO 2 in a flowing gas phase and HCO 3- in a static aqueous phase, and radioactive decay are incorporated. The governing equation is solved analytically by the method of characteristics. The mass fraction of 14C in the gas phase,X 14g, is controlled by radioactive decay. The relatively long half-line of 14C, about 5720 years, and the relatively shallow proposed burial depth of the radioactive waste, about 350m, requires significant retardation of the 14C wave velocity for significant reduction in X 14g. 14C wave velocity is most sensitive to temperature and pH which control the distribution of total carbon between gas and liquid phase; the greater the partitioning of carbon into the liquid phase, the greater the retardation of the 14C wave velocity and the greater the ultimate reduction in X 14g from initial conditions. Partitioning of total carbon into the liquid phase is greatest at low temperatures, 8. Increasing water saturation also tends to retard 14C wave velocity but to a lesser extent. The governing equation has been applied using conditions that may possibly occur at the proposed Yucca Mountain repository. Calculations indicate that the 14C wave takes about 5900 years to reach the surface with a X 14g equal to 25 ppm. Diffusion and dispersion are not of major importance for these conditions. These calculations are approximate due to the number of assumptions involved. Discharge of 14C into the gas before the selected time would accelerate wave arrival and increase the amount of 14C reaching the surface.

  6. {Delta}I = 3/2 and {Delta}S = 2 Hyperon decays in chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    He, X.G. [University of Melbourne, Parkville, VIC (Australia). School of Physics; Valencia, G. [Iowa State University, Ames, Iowa (United States). Department of Physics and Astronomy

    1997-05-01

    We study the| {Delta}I| = 3/2 and |{Delta}S| = 2 amplitudes for hyperon decays of the form B {yields} B`{pi} at lowest order in chiral perturbation theory. At this order, the {Delta}I = 3/2 amplitudes depend on only one constant. We extract the value of this constant from experiment and find a reasonable description of these processes within experimental errors. The same constant determines the {Delta}S = 2 transitions which, in the standard model, are too small to be observed. We find that new physics with parity odd {Delta}S = 2 interactions can produce observable rates in hyperon decays while evading the bounds from K{sup 0} - K-bar{sup 0} mixing. (authors) 10 refs., 3 tabs.

  7. Discussion: Reporting and calibration of post-bomb 14C data

    Energy Technology Data Exchange (ETDEWEB)

    Reimer, P J; Brown, T A; Reimer, R W

    2004-10-11

    The definitive paper by Stuiver and Polach (1977) established the conventions for reporting of {sup 14}C data for chronological and geophysical studies based on the radioactive decay of {sup 14}C in the sample since the year of sample death or formation. Several ways of reporting {sup 14}C activity levels relative to a standard were also established, but no specific instructions were given for reporting nuclear weapons testing (post-bomb) {sup 14}C levels in samples. Because the use of post-bomb {sup 14}C is becoming more prevalent in forensics, biology, and geosciences, a convention needs to be adopted. We advocate the use of fraction modern with a new symbol F{sup 14}C to prevent confusion with the previously used Fm, which may or may not have been fractionation corrected. We also discuss the calibration of post-bomb {sup 14}C samples and the available datasets and compilations, but do not give a recommendation for a particular dataset.

  8. Effect of clipping, benomyl, and genet on [sup 14]C transfer between mycorrhiz plants

    Energy Technology Data Exchange (ETDEWEB)

    Waters, J.R.; Borowicz, V.A. (Dept. of Biological Sciences, Ecology Group, Illinois State Univ., Normal, IL (United States))

    1994-11-01

    We examined how simulated herbivore, fungicide, and genet affect the magnitude and direction of net carbon transfer between paired mycrrhizal Lotus corniculatus. One plant in each pair was labeled with [sup 14]C, and [sup 14]C levels in the unlabeled plant were quantified. Without fungicide, the roots of unlabeled plants received significantly more [sup 14]C when the labeled partner was clipped than when the unlabeled plant was clipped, indicating that net carbon flow was away from clipped plants and toward unclipped plants. Because the specific activity of donor roots was unaffected by simulated herbivore, fungicide, and genet, significant differences in net carbon flow were not affect carbon transfer between plants in trays treated with the fungicide benomyl, which probably reduced but did not eliminate VAM colonization. The three genets did not differ. The median [sup 14]C levels of unlabeled root samples were only 1.2% the [sup 14]C levels of labeled plants' roots and thus constituted a very small portion of their carbon budget. [sup 14]C levels in stems of unlabeled plants were never above background, suggesting that the fungal symbiont retained most of the transferred carbon. Although clipping can affect net carbon flow, we failed to detect significant differences in the amount of [sup 14]C leaking from the roots of clipped vs unclipped plants. This study suggests that grazed mycorrhizal plants are unlikely to gain significant amounts of carbohydrates from neighbors and may actually experience a net loss. (au).

  9. Large 14C excursion in 5480 BC indicates an abnormal sun in the mid-Holocene

    Science.gov (United States)

    Miyake, Fusa; Jull, A. J. Timothy; Panyushkina, Irina P.; Wacker, Lukas; Salzer, Matthew; Baisan, Christopher H.; Lange, Todd; Cruz, Richard; Masuda, Kimiaki; Nakamura, Toshio

    2017-01-01

    Radiocarbon content in tree rings can be an excellent proxy of the past incoming cosmic ray intensities to Earth. Although such past cosmic ray variations have been studied by measurements of 14C contents in tree rings with ≥10-y time resolution for the Holocene, there are few annual 14C data. There is a little understanding about annual 14C variations in the past, with the exception of a few periods including the AD 774‑775 14C excursion where annual measurements have been performed. Here, we report the result of 14C measurements using the bristlecone pine tree rings for the period from 5490 BC to 5411 BC with 1- to 2-y resolution, and a finding of an extraordinarily large 14C increase (20‰) from 5481 BC to 5471 BC (the 5480 BC event). The 14C increase rate of this event is much larger than that of the normal grand solar minima. We propose the possible causes of this event are an unknown phase of grand solar minimum, or a combination of successive solar proton events and a normal grand solar minimum.

  10. Autoradiographic studies on distribution of L-3,4-dihydroxyphenylalanine (L-DOPA)-14C and L-5-hydroxytryptophan (L-5-HTP)-14C in the cat brain.

    Science.gov (United States)

    Miyakoshi, N; Tanaka, M; Shindo, H

    1980-12-01

    The distribution and metabolism of L-DOPA-14C and L-5-HTP-14C in the cat brain were examined by means of autoradiography and chromatography. The results revealed that an appreciable amount of radioactivity in the gray matter, but not the white, and that the localization of radioactivity of L-DOPA and L-5-HTP significantly differed. After L-DOPA-14C administration, a high accumulation was found in the caudate nucleus, putamen and pallidum. With L-5-HTP-14C administration, high radioactivity was observed in the hypothalamus, raphe nucleus, substantia nigra, inferior olivalis and caudate nucleus. An analysis of the main metabolites of both amino acids in various regions of the brain was also made. When L-DOPA was given, a high concentration of dopamine was detected in the caudate nucleus, followed by the hypothalamus. In the case of L-5-HTP, a high concentration of serotonin was detected in the hypothalamus and the medulla oblongata. These results suggest that amines derived from exogenously administered L-DOPA and L-5-HTP accumulate in the brain regions known as the corresponding amine rich regions, under physiological conditions.

  11. Synthesis of 7. cap alpha. -chloro-16. cap alpha. -methylprednisolone 17. cap alpha. ,21-dipropionate-4-/sup 14/C (alclometasone dipropionate-4-/sup 14/C). [Antiinflammatory Agent

    Energy Technology Data Exchange (ETDEWEB)

    Terasawa, Tadao; Atsumi, Kazunori; Yokoshima, Tetsuyoshi; Ohyabu, Shintaro; Fukasaku, Noboru

    1986-09-01

    In order to study the bioavailability, metabolism and protein-binding effects of the new antiinflammatory corticoid, alclometasone dipropionate, it was required to obtain the biochemically stable /sup 14/C-labelled substrate. In the present publication we describe an efficient synthesis of the title compound.

  12. Timing is Everything:The Boon and Bane of 14C Geochronology

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T; Guilderson, T; Reimer, P J; Brown, T

    2004-10-29

    There are underappreciated limitations of the conversion of {sup 14}C-ages to the fixed, calendrical time-scale that bear directly upon our understanding of the dynamic climate system, or the relationship between the collapse of one civilization and it's neighbor's. In this paper we present a quantitative assessment of the limits of {sup 14}C-geochronology and calibration onto the absolute calendrical time-scale over the Holocene. We take into account not only the inherent limitations of the {sup 14}C-calendar calibration curve, but also analytical uncertainties.

  13. /sup 14/C-triolein breath test in the diagnosis of steatorrhea

    Energy Technology Data Exchange (ETDEWEB)

    Hoeeg, V.; Schjoensby, H.

    1988-08-01

    The /sup 14/C-triolein breath test was evaluated as a screening test for steatorrhea in 66 consecutive patients. Steatorrhea was found in 20 patients. Following an oral dose of /sup 14/C-triolein, /sup 14/CO2-activity in the expiratory air was measured after zero, three, four, five and six hours. Maximum /sup 14/CO 2-expiration was calculated. The ability of the test to discriminate between patients with steatorrhea and patients without steatorrhea showed a specificity of 98%, and a sensitivity of 85%. Thus the /sup 14/C-triolein test seems to be sufficiently accurate as a screening test for steatorrhea.

  14. Mineralisation of (14)C-labelled polystyrene plastics by Penicillium variabile after ozonation pre-treatment.

    Science.gov (United States)

    Tian, Lili; Kolvenbach, Boris; Corvini, Nora; Wang, Songfeng; Tavanaie, Nasrin; Wang, Lianhong; Ma, Yini; Scheu, Stefan; Corvini, Philippe François-Xavier; Ji, Rong

    2016-07-19

    Large amounts of polystyrene (PS), one of the most widely used plastics in the world, end up in the environment through industrial discharge and littering, becoming one of the major components of plastic debris. Such plastics, especially the small-sized microplastics and nanoplastics, have received increasing concerns in terms of their potential environmental risks. Feasible approaches for the degradation of PS in waste materials and in the environment are highly desirable. Physicochemical pretreatments of PS may be applied to enhance biological degradation. In the present study, we synthesized (14)C-labelled PS polymers, either uniformly labelled on the ring ([U-ring-(14)C]-PS) or labelled at the β-carbon position of the alkyl chain ([β-(14)C]-PS), and investigated the mineralisation of the (14)C-PS polymers by the fungus Penicillium variabile CCF3219 as well as the effect of ozonation as a physico-chemical pre-treatment on the mineralisation by the fungi. Biodegradation of the (14)C-PS polymers was studied in liquid medium (pH 7.5, without additional carbon substrate) with P. variabile for 16 weeks. During the incubation time, (14)CO2 was captured to calculate the mineralisation of (14)C-PS and the remaining polymers were analysed by means of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrometry and gel-permeation chromatography (GPC). The results showed that the fungi mineralised both labelled polymers, and that the [U-ring-(14)C]-PS with a lower molecular weight led to a higher mineralisation rate. Ozonation pre-treatment strongly enhanced mineralisation of [β-(14)C]-PS. SEM analysis showed that the surface of the ozonated [β-(14)C]-PS became uneven and rough after the incubation, indicating an attack on the polymer by P. variabile. FT-IR analysis showed that ozonation generated carbonyl groups on the [β-(14)C]-PS and the amount of the carbonyl groups decreased after incubation of the [β-(14)C]-PS with P. variabile. GPC

  15. Synthesis of {sup 14}C-labeled levamisole and {sup 13}C-labeled tetramisole

    Energy Technology Data Exchange (ETDEWEB)

    Feil, V.J. [US Department of Agriculture, Agricultural Research Service, Biosciences Research Lab., Fargo, ND (United States)

    1996-12-01

    The syntheses of {sup 14}C-ring labeled levamisole ([-]-2,3,5,6-tetrahydro-6-phenyl [{sup 14}C]-UL imidazo[2,1-b]thiazole) from acetophenone-ring-UL-{sup 14}C in 5 steps plus resolution with a 7.5% overall yield, and {sup 13}C{sub 6}-ring labeled tetramisole ([{+-}]-2,3,5,6-tetrahydro-6-phenyl [{sup 13}C{sub 6}]imidazo[2,1-b]thiazole) from benzene-{sup 13}C{sub 6} in 6 steps with a 9.0% overall yield are described. (author).

  16. Natural Abundance 14C Content of Dibutyl Phthalate (DBP from Three Marine Algae

    Directory of Open Access Journals (Sweden)

    Kazuyo Ukai

    2006-11-01

    Full Text Available Abstract: Analysis of the natural abundance 14C content of dibutyl phthalate (DBP from two edible brown algae, Undaria pinnatifida and Laminaria japonica, and a green alga, Ulva sp., revealed that the DBP was naturally produced. The natural abundance 14C content of di-(2-ethylhexyl phthalate (DEHP obtained from the same algae was about 50-80% of the standard sample and the 14C content of the petrochemical (industrial products of DBP and DEHP were below the detection limit.

  17. Tracing the intrusion of fossil carbon into coastal Louisiana macrofauna using natural 14C and 13C abundances

    Science.gov (United States)

    Wilson, Rachel M.; Cherrier, Jennifer; Sarkodee-Adoo, Judith; Bosman, Samantha; Mickle, Alejandra; Chanton, Jeffrey P.

    2016-07-01

    The Deepwater Horizon oil spill released a large volume of 13C and radiocarbon depleted organic matter to the northern Gulf of Mexico. Evidence of petroleum-derived carbon entering the offshore planktonic foodweb, as well as widespread oiling of coastal areas documented in previous studies suggests that hydrocarbons could have entered the near shore foodweb. To test this hypothesis, we measured radiocarbon (Δ14C%) and stable carbon isotopes (δ13C) in an assortment of fish tissue, invertebrate tissue and shell samples collected within a year of the spill at seven sites from Louisiana to Florida USA across the northern Gulf of Mexico. We observed a west-east gradient with the most depleted radiocarbon values found in Terrebonne Bay, Louisana and increasingly enriched radiocarbon values in organisms collected at sites to the east. Depleted radiocarbon values as low as -10% in invertebrate soft tissue from Terrebonne suggest assimilation of fossil carbon (2.8±1.2%), consistent with the hypothesis that organic matter from petrochemical reservoirs released during the Deepwater Horizon spill entered the coastal food web to a limited extent. Further there was a significant correlation between radiocarbon and δ13C values in invertebrate tissue consistent with this hypothesis. Both oyster tissue and hard head catfish tissue collected in impacted areas of coastal Louisiana were significantly depleted in 14C and 13C relative to organisms collected in the unaffected Apalachicola Bay, Florida (pgulf coast or that the organisms ingest carbon derived from 14C depleted organic matter mobilized during the erosion of coastal marshes in southern Louisiana.

  18. Dermal penetration of [14C]captan in young and adult rats.

    Science.gov (United States)

    Fisher, H L; Hall, L L; Sumler, M R; Shah, P V

    1992-07-01

    Age dependence in dermal absorption has been a major concern in risk assessment. Captan, a chloroalkyl thio heterocyclic fungicide, was selected for study of age dependence as representative of this class of pesticides. Dermal penetration of [14C]captan applied at 0.286 mumol/cm2 was determined in young (33-d-old) and adult (82-d-old) female Fischer 344 rats in vivo and by two in vitro methods. Dermal penetration in vivo at 72 h was about 9% of the recovered dose in both young and adult rats. The percentage penetration was found to increase as dosage (0.1, 0.5, 2.7 mumol/cm2) decreased. Two in vitro methods gave variable dermal penetration values compared with in vivo results. A static system yielded twofold higher dermal penetration values compared with in vivo results for both young and adult rats. A flow system yielded higher dermal penetration values in young rats and lower penetration values in adults compared with in vivo results. Concentration in body, kidney, and liver was less in young than in adult rats given the same absorbed dosage. A physiological pharmacokinetic model was developed having a dual compartment for the treated skin and appeared to describe dermal absorption and disposition well. From this model, tissue/blood ratios of captan-derived radioactivity for organs were found to range from 0.35 to 3.4, indicating no large uptake or binding preferences by any organ. This preliminary pharmacokinetic model summarizes the experimental findings and could provide impetus for more complex and realistic models.

  19. Organic matter composition and stabilization in a polygonal tundra soil of the Lena Delta

    Directory of Open Access Journals (Sweden)

    S. Höfle

    2013-05-01

    Full Text Available This study investigated soil organic matter (OM composition of differently stabilized soil OM fractions in the active layer of a polygonal tundra soil in the Lena Delta, Russia, by applying density and particle size fractionation combined with qualitative OM analysis using solid state 13C nuclear magnetic resonance spectroscopy, and lipid analysis combined with 14C analysis. Bulk soil OM was mainly composed of plant-derived, little-decomposed material with surprisingly high and strongly increasing apparent 14C ages with active layer depth suggesting slow microbial OM transformation in cold climate. Most soil organic carbon was stored in clay and fine-silt fractions (n-alkane and n-fatty acid compounds and low alkyl/O-alkyl C ratios. Organo-mineral associations, which are suggested to be a key mechanism of OM stabilization in temperate soils, seem to be less important in the active layer as the mainly plant-derived clay- and fine-silt-sized OM was surprisingly "young", with 14C contents similar to the bulk soil values. Furthermore, these fractions contained less organic carbon compared to density fractionated OM occluded in soil aggregates – a further important OM stabilization mechanism in temperate soils restricting accessibility of microorganisms. This process seems to be important at greater active layer depth where particulate OM, occluded in soil aggregates, was "older" than free particulate OM.

  20. Establishing constraints on groundwater ages with {sup 36}Cl, {sup 14}C, {sup 3}H, and noble gases: A case study in the eastern Paris basin, France

    Energy Technology Data Exchange (ETDEWEB)

    Lavastre, Veronique, E-mail: veronique.lavastre@univ-st-etienne.fr [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France)] [CNAB, CNRS - UMR 5084, BP120, 33175 Gradignan (France)] [Laboratoire de Geochimie des Isotopes Stables, Institut de Physique du Globe de Paris, Universite Paris 7, UMR CNRS 7154, 2, Place Jussieu, 75251 Paris Cedex 05 (France); Salle, Corinne Le Gal La [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France)] [GIS, Universite de Nimes, 150 Rue Georges Besse, 30035 Nimes (France); Michelot, Jean-Luc [IDES, UMR 8148 CNRS - Universite Paris-Sud, Bat. 504, 91405 Orsay (France); Giannesini, Sophie [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France)] [GIS, Universite de Nimes, 150 Rue Georges Besse, 30035 Nimes (France); Benedetti, Lucilla [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France); Lancelot, Joel [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France)] [GIS, Universite de Nimes, 150 Rue Georges Besse, 30035 Nimes (France); Lavielle, Bernard [CNAB, CNRS - UMR 5084, BP120, 33175 Gradignan (France); Massault, Marc [IDES, UMR 8148 CNRS - Universite Paris-Sud, Bat. 504, 91405 Orsay (France); Thomas, Bertrand; Gilabert, Eric [CNAB, CNRS - UMR 5084, BP120, 33175 Gradignan (France); Bourles, Didier [CEREGE, CNRS - UMR 6635, Europole Mediterraneen de l' Arbois, 13545 Aix-en-Provence (France); Clauer, Norbert [Centre de Geochimie de la Surface (CNRS/ULP), Universite Louis Pasteur, 1 rue Blessig, 67084 Strasbourg (France); Agrinier, Pierre [Laboratoire de Geochimie des Isotopes Stables, Institut de Physique du Globe de Paris, Universite Paris 7, UMR CNRS 7154, 2, Place Jussieu, 75251 Paris Cedex 05 (France)

    2010-01-15

    Groundwaters from the Tithonian/Kimmeridgian, Oxfordian and Upper Dogger aquifers, within the eastern part of the Paris basin (France), were characterised using {sup 3}H, {sup 14}C and {sup 36}Cl, and noble gases tracers, to evaluate their residence times and determine their recharge period. This information is an important prerequisite to evaluating the confinement properties of the Callovo-Oxfordian clay formation sandwiched between the Oxfordian aquifer and the Dogger aquifer, currently being investigated by the French nuclear waste management agency (Andra) for radioactive waste disposal. Data presented in this paper are used to test 4 hypotheses. (1)The Oxfordian limestone is isolated from the overlying Tithonian/Kimmeridgian surface aquifer. This first hypothesis is supported by the presence of measurable {sup 3}H activities in groundwaters from the surface aquifer (6-11 TU), and by its absence in groundwaters derived from deeper aquifers (<3 TU), as well as by geochemical data from earlier studies. (2)The Callovo-Oxfordian clay sequence in the vicinity of the URL serves as an effective barrier to advective flow and transport between the underlying Upper Dogger aquifer and the overlying Oxfordian limestone aquifer. This second hypothesis is supported by relatively low concentrations of Cl (3.5-78 mg L{sup -1}), Na (15-145 mg L{sup -1}), Br (0.08-0.4 mg L{sup -1}) and {sup 4}He{sub rad} (0.2-2.3 ccSTP g{sup -1}) and slightly higher {sup 36}Cl/Cl ratios (2.7-59 x 10{sup -15} at at{sup -1}) in groundwaters from the Oxfordian aquifer, compared to those from the Upper Dogger aquifer (345-4027 mgCl L{sup -1}; 402-2390 mgNa L{sup -1}, 1.8-22.2 mgBr L{sup -1}, 1.6-37.2 ccSTP He g{sup -1}, 1-5 x 10{sup -15} at {sup 36}Cl at{sup -1} Cl). (3)Groundwaters from the Oxfordian aquifer, in the vicinity of URL are pre-Holocene, with residence times exceeding 10 ka. Geochemical and isotopic lines of evidence for this hypothesis include: (a){delta}{sup 13}C values measured on

  1. Intracavity optogalvanic spectroscopy. An analytical technique for 14C analysis with subattomole sensitivity.

    Science.gov (United States)

    Murnick, Daniel E; Dogru, Ozgur; Ilkmen, Erhan

    2008-07-01

    We show a new ultrasensitive laser-based analytical technique, intracavity optogalvanic spectroscopy, allowing extremely high sensitivity for detection of (14)C-labeled carbon dioxide. Capable of replacing large accelerator mass spectrometers, the technique quantifies attomoles of (14)C in submicrogram samples. Based on the specificity of narrow laser resonances coupled with the sensitivity provided by standing waves in an optical cavity and detection via impedance variations, limits of detection near 10(-15) (14)C/(12)C ratios are obtained. Using a 15-W (14)CO2 laser, a linear calibration with samples from 10(-15) to >1.5 x 10(-12) in (14)C/(12)C ratios, as determined by accelerator mass spectrometry, is demonstrated. Possible applications include microdosing studies in drug development, individualized subtherapeutic tests of drug metabolism, carbon dating and real time monitoring of atmospheric radiocarbon. The method can also be applied to detection of other trace entities.

  2. Synthesis of [sup 14]C-labeled copolymers for drug delivery studies

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, S.W.; Reist, E.J. (SRI International, Menlo Park, CA (United States)); Rock, M.T.

    1994-02-01

    [sup 14]C-labeled polyanhydride copolymers [(20:80)/1,3-bis(p-carboxyphenoxy)-propane (CPP):sebacic acid (SA)] were synthesized according to schemes I and II: [sup 14]C-labeled sebacic acid (2,9-[sup 14]C[sub 2]) and [sup 14]C-labeled CPP 1,3-bis(p-carboxyphenoxy)-propane (labeled at C-1, C-3 of the propyl group) were transformed to the corresponding mixed anhydrides as prepolymers respectively by reaction with acetic anhydride. The labeled mixed anhydride prepolymers were condensed with unlabeled counter-prepolymers to give the labeled polyanhydride copolymers. The labeled copolymers were identified and characterized by gel permeation chromatography (GPC). (author).

  3. Preparative-scale enzymic synthesis of D-[14C]ribulose 1,5-bisphosphate.

    Science.gov (United States)

    Kuehn, G D; Hsu, T C

    1978-01-01

    A procedure is described to prepare uniformly labelled D-[14C]ribulose 1,5-bisphosphate enzymically from uniformly labelled D-[14C]glucose through the coupled reactions catalysed by hexokinase (EC 2.7.1.1), glucose 6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1.1.1.44) and 5-phosphoribulokinase (EC 2.7.1.19). All reagents utilized in the method are commercially available. The procedure is a reliable preparative-scale method for synthesizing the dibarium salt of D-[14C]ribulose 1,5-biphosphate with a specific radioactivity up to 7 mCi/mmol and a purity near 90%. The final product was free of other 14C-labelled sugars, sugar phosphate esters, Pi and nucleotides. PMID:217356

  4. Systemic distribution of sup 14 C-labeled formaldehyde applied in the root canal following pulpectomy

    Energy Technology Data Exchange (ETDEWEB)

    Hata, G.I.; Nishikawa, I.; Kawazoe, S.; Toda, T.

    1989-11-01

    The systemic distribution of {sup 14}C-labeled formaldehyde which had been placed in the root canals of the canines of cats following pulpectomies was studied using liquid scintillation counting and whole-body autoradiographic technique. Radioactive {sup 14}C which had been placed in the canals was found in the plasma 30 min after the root canal procedure. The recovery of systemic {sup 14}C radioactivity increased with time. In addition, it seemed that approximately 3% of the dose placed in the teeth was excreted in the urine within 36 h. Whole-body autoradiograms indicated extensive concentration of {sup 14}C radioactivity in tissues other than those analyzed with the liquid scintillation technique.

  5. The 14C(n,γ) cross section between 10 keV and 1 M

    CERN Document Server

    Reifarth, R; Forssén, C; Besserer, U; Couture, A; Dababneh, S; Dörr, L; Görres, J; Haight, R C; Käppeler, F; Mengoni, A; O'Brien, S; Patronis, N; Plag, R; Rundberg, R S; Wiescher, M; Wilhelmy, J B

    2008-01-01

    The neutron capture cross section of 14C is of relevance for several nucleosynthesis scenarios such as inhomogeneous Big Bang models, neutron induced CNO cycles, and neutrino driven wind models for the r process. The 14C(n,γ) reaction is also important for the validation of the Coulomb dissociation method, where the (n,γ) cross section can be indirectly obtained via the time-reversed process. So far, the example of 14C is the only case with neutrons where both, direct measurement and indirect Coulomb dissociation, have been applied. Unfortunately, the interpretation is obscured by discrepancies between several experiments and theory. Therefore, we report on new direct measurements of the 14C(n,γ) reaction with neutron energies ranging from 20 to 800 keV.

  6. (AJST) EU/Th AND 14C ISOTOPE DATING OF LAKE SEDIMENTS ...

    African Journals Online (AJOL)

    opiyo

    sampling resolution has been coarse, entailing extrapolations over time periods where there may have been .... is the assumption that atmospheric 14C levels have remained constant ... reservoirs; variations in the amount of carbon dioxide in.

  7. Synthesis and analysis of the opioid analgesic [[sup 14]C]-fentanyl

    Energy Technology Data Exchange (ETDEWEB)

    Bagley, J.R.; Wilhelm, J.A. (Anaquest Inc., Murray Hill, NJ (United States))

    1992-11-01

    The synthesis of [[sup 14]C]-fentanyl, the radiolabelled congener of the potent opioid analgesic chosen for utilization in drug disposition studies, is described. [[sup 14]C]-Labelling was achieved in the first of two steps, a room temperature reduction of the in situ generated Schiff base from 1-phenylethyl-4-piperidone and [UL-[sup 14]C]-aniline hydrochloride with sodium triacetoxyborohydride. A nearly instantaneous production of fentanyl was accomplished at room temperature with the addition of propionyl chloride. The overall radiochemical yield was 18%. The method described is efficiently adaptable for submicromolar scale while yielding a product of sufficient specific activity for in vivo studies. Our solvent system for thin layer chromatography was superior to the USP system reported for chromatographic analysis of fentanyl. This is the first reported preparation of [[sup 14]C]-fentanyl with the radiolabel in the aniline benzene ring. (author).

  8. Effect of HF leaching on {sup 14}C dates of pottery

    Energy Technology Data Exchange (ETDEWEB)

    Goslar, Tomasz, E-mail: goslar@radiocarbon.pl [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznan (Poland); Poznan Radiocarbon Laboratory, ul. Rubiez 46, 61-612 Poznan (Poland); Kozlowski, Janusz [Institute of Archaeology, Jagiellonian University, ul. Golebia 11, 30-007 Krakow (Poland); Szmyt, Marzena [Institute for Eastern Studies, Adam Mickiewicz University, ul. 28 Czerwca 1956 nr 198, 61-486 Poznan (Poland); Czernik, Justyna [Poznan Radiocarbon Laboratory, ul. Rubiez 46, 61-612 Poznan (Poland)

    2013-01-15

    This paper presents the experiments with {sup 14}C dating of two potsherds, which contained carbon dispersed rather homogeneously in their clay fabric. After AAA treatment, the potsherds still appeared to be contaminated with young carbon, presumably connected with humic acids. To make removal of humic acids more effective, we treated the sherds with HF acid of different concentration. The {sup 14}C results obtained demonstrate that HF treatment indeed helps to remove humic contaminants, but it also mobilizes carbon bound to raw clay, which may make {sup 14}C dates too old. We conclude therefore, that using a simple combination of HF and AAA treatment seems insufficient in reliable {sup 14}C dating of carbon homogeneously dispersed in the volume of potsherds.

  9. Diffusion of /sup 14/C-labeled formocresol and glutaraldehyde in tooth structures

    Energy Technology Data Exchange (ETDEWEB)

    Wemes, J.C.; Purdell-Lewis, D.; Jongebloed, W.; Vaalburg, W.

    1982-09-01

    /sup 14/C-Formocresol and /sup 14/C-glutaraldehyde were placed in the root canals of freshly extracted human teeth. The outward diffusion of labeled aldehydes was then measured and autoradiograms of cross-sections taken. No diffusion of glutaraldehyde was detectable within 72 hours, whereas there was a rapidly increasing outflow of formocresol during the same period. In a separate group normal root canal treatment was completed until 2 mm. short of the roentgenologic apex with glutaraldehyde as an irrigant. The walls of the root canals of some of the specimens were examined with electron microscopy and the outflow of /sup 14/C-formocresol which was later placed in some specimens was counted. The use of glutaraldehyde as an irrigant resulted in closure of the apical third of the root canal as indicated by the absence of /sup 14/C-formocresol diffusion.

  10. Irradiation Scheme Design of 14C Production on 49-2 Reactor

    Institute of Scientific and Technical Information of China (English)

    SUN; Zheng; LIU; Xing-min; XU; Zhi-long; ZHANG; Ya-dong

    2012-01-01

    <正>14C is a radioisotope of carbon, it is widely used in pharmacy, medical treatment, agriculture, reconnoiter and archaeology. 49-2 research reactor is a swimming pool style reactor which has operated for more than 40 years. The application of 49-2 reactor includes the radio nuclides production. Therefore, the technical scheme on 14C irradiation in 49-2 reactor should be prepared elaborately.

  11. Synthesis of mutagenic 2,4-dinitro-[7-[sup 14]C]benzaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, Miki; Kozuka, Hiroshi; Honda, Takashi (Toyama Medical and Pharmaceutical Univ. (Japan)); Mori, Masaaki (Kyushu Univ., Fukuoka (Japan). School of Health Sciences); Sayama, Michio (Toyama Univ. (Japan))

    1994-07-01

    2,4-Dinitro-[7-[sup 14]C]benzaldehyde (4), a mutagenic substance which may have unique metabolic activating pathways, was synthesized as a tracer for the detection of adducts of 4 with macromolecules. The preparation was performed in four steps from [7-[sup 14]C]toluene to give an overall radiochemical yield of 20% after purifying by TLC. The radiochemical purity was over 98%. (Author).

  12. 14C release from a Soviet-designed pressurized water reactor nuclear power plant.

    Science.gov (United States)

    Uchrin, G; Csaba, E; Hertelendi, E; Ormai, P; Barnabas, I

    1992-12-01

    The Paks Nuclear Power Plant in Hungary runs with four pressurized water reactors, each of 440-MWe capacity. Sampling systems have been developed and used to determine the 14C of various chemical forms (14CO2, 14CO, 14CnHm) in the airborne releases. The average normalized yearly discharge rates for the time period 1988-1991 are equal to 0.77 TBq GWe-1 y-1 for hydrocarbons and 0.05 TBq GWe-1 y-1 for CO2. The contribution of 14CO was less than 0.5% of the total emission. The 14C discharge rate is estimated to be four times higher than the corresponding mean data of Western European pressurized water reactors. The calculated effective dose equivalent to individuals living in the vicinity of the power plant, due to 14C release, was 0.64 microSv in 1991 while the effective dose equivalent due to the natural 14C level was 15 microSv y-1. The long-term global impact of the 14C release in the operational period of the plant (1982-1991) was 1,270 man-Sv. The 14C excess in the environmental air has been measured since 1989 by taking biweekly samples at a distance of 1.7 km from the nuclear power plant. The long-term average of radiocarbon excess coming from the power plant was 2 mBq m-3. The local 14C deposition was followed by tree ring analysis, too. No 14C increase higher than the uncertainty of the measurement (four per thousand = 0.17 mBq m-3) was observed.

  13. Assessing open-system behavior of 14C in terrestrial gastropod shells

    Science.gov (United States)

    Rech, Jason A.; Pigati, Jeffrey S.; Lehmann, Sophie B.; McGimpsey, Chelsea N.; Grimley, David A.; Nekola, Jeffrey C.

    2011-01-01

    In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190-130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to apparent 14C ages between 48.2 and 42.1 ka. This small level of open-system behavior is common in many materials that are used for 14C dating (e.g. charcoal), and typically sets the upper practical limit of the technique. Two aliquots of gastropod shells from the Illinoian-aged Petersburg Silt (Petersburg Section) in central Illinois, USA, however, yielded elevated 14C activities of 1.26 and 1.71 pMC, which correspond to apparent 14C ages of 35.1 and 32.7 ka. Together, these results suggest that while many fossil gastropods shells may not suffer from major (>1%) open-system problems, this is not always the case. We then examined the mineralogy, trace element chemistry, and physical characteristics of a suite of fossil and modern gastropod shells to identify the source of contamination in the Petersburg shells and assess the effectiveness of these screening techniques at identifying samples suitable for 14C dating. Mineralogical (XRD) and trace element analyses were inconclusive, which suggests that these techniques are not suitable for assessing open-system behavior in terrestrial gastropod shells. Analysis with scanning electron microscopy (SEM), however, identified secondary mineralization (calcium carbonate) primarily within the inner whorls of the Petersburg shells. This indicates that SEM examination, or possibly standard microscope examination, of the interior of gastropod shells should be used when selecting fossil gastropod shells for 14C dating.

  14. [14C]deoxyglucose labelling of functional activity in the cephalopod central nervous system.

    Science.gov (United States)

    Novicki, A; Messenger, J B; Budelmann, B U; Terrell, M L; Kadekaro, M

    1992-07-22

    For the first time, the [14C]deoxyglucose radioautographic technique has been successfully used to map physiological activity in cephalopod brains. In unilaterally blinded octopus and cuttlefish, the optic lobe of the deprived side showed a decreased uptake of the labelled tracer. This suggests that the uptake is related to functional activity. The potential of the [14C]deoxyglucose technique as a powerful tool in studying the functional organization of cephalopod brains is discussed.

  15. Biological and biomedical (14)C-accelerator mass spectrometry and graphitization of carbonaceous samples.

    Science.gov (United States)

    Chung, Ill-Min; Kim, Seung-Hyun

    2013-06-21

    Accelerator mass spectrometry (AMS) is the ultimate technique for measuring rare isotopes in small samples. Biological and biomedical applications of (14)C-AMS (bio-(14)C-AMS) commenced in the early 1990s and are now widely used in many research fields including pharmacology, toxicology, food, and nutrition. For accurate, precise, and reproducible bio-(14)C-AMS analysis, the graphitization step in sample preparation is the most critical step. So, various sample preparation methods for a process called graphitization have been reported for specific applications. Catalytic graphitization using either a flame-sealed borosilicate tube or a septa-sealed vial is a popular sample preparation method for bio-(14)C-AMS. In this review, we introduce the AMS system, especially for bio-(14)C-AMS. In addition, we also review the graphitization method for bio-(14)C-AMS to promote further understanding and improvement of sample preparation for this technique. Examples of catalytic graphitization methods over the past two decades are described.

  16. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb (14)C.

    Science.gov (United States)

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan; Magnusson, Stig Peter; Kjaer, Michael

    2013-05-01

    Tendons are often injured and heal poorly. Whether this is caused by a slow tissue turnover is unknown, since existing data provide diverging estimates of tendon protein half-life that range from 2 mo to 200 yr. With the purpose of determining life-long turnover of human tendon tissue, we used the (14)C bomb-pulse method. This method takes advantage of the dramatic increase in atmospheric levels of (14)C, produced by nuclear bomb tests in 1955-1963, which is reflected in all living organisms. Levels of (14)C were measured in 28 forensic samples of Achilles tendon core and 4 skeletal muscle samples (donor birth years 1945-1983) with accelerator mass spectrometry (AMS) and compared to known atmospheric levels to estimate tissue turnover. We found that Achilles tendon tissue retained levels of (14)C corresponding to atmospheric levels several decades before tissue sampling, demonstrating a very limited tissue turnover. The tendon concentrations of (14)C approximately reflected the atmospheric levels present during the first 17 yr of life, indicating that the tendon core is formed during height growth and is essentially not renewed thereafter. In contrast, (14)C levels in muscle indicated continuous turnover. Our observation provides a fundamental premise for understanding tendon function and pathology, and likely explains the poor regenerative capacity of tendon tissue.

  17. Future needs and requirements for AMS {sup 14}C standards and reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Scott, E. Marian E-mail: marian@stats.gla.ac.uk; Boaretto, Elisabetta; Bryant, Charlotte; Cook, Gordon T.; Gulliksen, Steinar; Harkness, Doug D.; Heinemeier, Jan; McGee, Edward; Naysmith, Philip; Possnert, Goran; Plicht, Hans van der; Strydonck, Mark van

    2004-08-01

    {sup 14}C measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of {sup 14}C measurement was tied to 1890 wood, through the 'primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST - National Institute of Standards and technology) subsequently replaced by NBS-OxII. These are both internationally calibrated and certified materials, whose {sup 14}C activities are known absolutely. A second tier of materials, often called secondary standards or reference materials, and including internationally recognised materials such as ANU-sucrose (now also IAEA-C6), Chinese - sucrose and the IAEA C1-C6 series, augmented by additional oxalic acid samples are also used routinely. The activity of these materials has been estimated from large numbers of measurements made by many laboratories. Recently, further natural materials from the Third and Fourth International Radiocarbon Inter-comparisons (TIRI and FIRI) have been added to this list. The activities of these standards and reference materials span both the applied {sup 14}C age range and the chemical composition range of typical samples, but this is not achieved uniformly and there is a continuing need for reference materials for laboratory quality control and measurement-traceability purposes. In this paper, we review the development of {sup 14}C standards and reference materials and consider the future requirements for such materials within the {sup 14}C AMS community.

  18. 基于遥感的辽河三角洲湿地生态系统服务价值评估%Value evaluation on ecosystem function of wetland in Liaohe River Delta

    Institute of Scientific and Technical Information of China (English)

    索安宁; 赵冬至; 卫宝泉; 陈艳拢

    2009-01-01

    利用中巴资源卫星对辽河三角洲盘锦湿地类型进行调查的基础上,综合应用环境经济学、资源经济学等方法对辽河三角洲湿地生态系统的服务功能价值进行了评估,得出该区域湿地生态系统的服务功能总价值为90.243×108元RMB.休闲娱乐、大气组分调节、物质生产和水文调节是该区域湿地生态系统服务功能价值的主要贡献者,分别占到系统总服务功能价值的25.93%、25.03%、22.35%和20.44%.%The main Liaohe River Delta is a wetland ecosystem, including the reef swamp, paddy field, mud flat, river, crab and shrimp field, barren mud and met meadow act surveyed by the remote sensing images of China-Brazil resource satellite. The evaluation on the main services in the wetland ecosystem of Liaohe River Delta was done by methods of environmental economics, resource economics, engineer building value and tour value. The total value in the wetland ecosystem services of Liaohe River Delta is about 90.243×108RMB. Among these services, the order of service value is: material output > air ingredients control > leisure service > flood control > habituating protection > culture service > pollution purification, with contribution of 25.93, 25.03, 22.35, 20.44, 3.17, 1.71 and 1.37%, respectively.

  19. AixMICADAS, the accelerator mass spectrometer dedicated to {sup 14}C recently installed in Aix-en-Provence, France

    Energy Technology Data Exchange (ETDEWEB)

    Bard, Edouard, E-mail: bard@cerege.fr [CEREGE, Aix-Marseille University, CNRS, IRD, Collège de France, Technopôle de l’Arbois, BP 80, F-13545 Aix-en-Provence (France); Tuna, Thibaut; Fagault, Yoann; Bonvalot, Lise [CEREGE, Aix-Marseille University, CNRS, IRD, Collège de France, Technopôle de l’Arbois, BP 80, F-13545 Aix-en-Provence (France); Wacker, Lukas; Fahrni, Simon; Synal, Hans-Arno [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland)

    2015-10-15

    A compact AMS system dedicated to measuring {sup 14}C in ultra-small samples was installed at the CEREGE in Aix-en-Provence at the end of March 2014, together with an automated graphitization system. AixMICADAS operates at around 200 kV with carbon ion stripping in helium leading to a transmission of about 47%. The hybrid ion source works with graphite targets and CO{sub 2} gas. It is coupled to a versatile gas interface system that ensures stable gas measurements from different sources: a cracker for CO{sub 2} in glass ampoules, an elemental analyzer for combusting organic matter and an automated system to handle carbonate by wet chemistry. The analyses performed during the first half-year of operation show that a precision of about 2‰ is reached on modern samples of about 1 mg of carbon. Measurements of IAEA reference materials of various {sup 14}C ages show a good agreement with consensus values. Direct measurements of geological graphites indicate a machine background equivalent to an age of 68,000 years BP. AixMICADAS is thus limited solely by the {sup 14}C contamination of samples in the field and in the laboratory. The performances of the gas ion source and its gas interface system were tested with two CO{sub 2} production units: the elemental analyzer and the automated carbonate hydrolysis unit. These tests show that samples ranging between 10 and 100 μg C can produce a {sup 12}C{sup −} ion beam of the order of 10–15 μA during time spans ranging from 3 to 30 min depending on the sample mass. Coupling the automated hydrolysis system to the gas ion source of AixMICADAS, enables us to develop a method involving sequential leaching of carbonate samples with direct {sup 14}C measurements of the leached fractions and the residual sample. The main advantage is that all of steps leaching and hydrolysis are performed in the same vial for a particular sample. A sequential leaching was applied to a young carbonate sample (ca. 6600 years BP) whose {sup 14}C age

  20. Displacement of nortriptyline and uptake of 14C-lidocaine in the lung after administration of 14C-lidocaine to nortriptyline intoxicated pigs.

    Science.gov (United States)

    Post, C; Lewis, D H

    1979-09-01

    Six anaesthetized Swedish land-race pigs were intoxicated by an intravenous infusion of nortriptyline-HCl (NT) up to a concentration of 4.58 +/- 0.58 (mean +/- S.E.M.) microM in arterial whole blood. A rapid injection of 2 mg/kg b.wt. lidocaine-HCl in the right atrium was followed by a rise in arterial whole blood concentration of NT up to a maximum of 7.32 +/- 0.28 microM NT. Amount displaced NT from the cardio-pulmonary circulation after the 14C-lidocaine bolus, was calculated to be 0.66 +/- 0.03 mumol. Lung uptake of 14C-lidocaine during first-pass through the lung was not influenced to any statistically signficant degree compared to a control group. Thus, first pass uptake (FPU) was 30 +/- 8 (mean +/- S.E.M.)% and 39 +/- 5% respectively. The duration of the QRS-complex of the ECG was increased (P less than 0.01) during the infusion of NT from 0.07 +/- 0.01 (mean +/- S.E.M.) sec. to 0.14 +/- 0.02 sec. when 250 mg NT-HCl had been administered. The QRS-duration was decreased (P less than 0.01) after the injection of the 14C-lidocaine bolus to 0.09 +/- 0.01 sec. Mean arterial blood pressure and heartrate decreased slightly during the infusion of NT, but did not change immediately after the 14C-lidocaine bolus.

  1. Progress in automated extraction and purification of in situ {sup 14}C from quartz: Results from the Purdue in situ {sup 14}C laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lifton, Nathaniel, E-mail: nlifton@purdue.edu [Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907 (United States); Department of Physics and Astronomy and Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Goehring, Brent, E-mail: bgoehrin@tulane.edu [Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907 (United States); Wilson, Jim, E-mail: jim.wilson@aeonlaboratories.com [Aeon Laboratories, LLC, 5835 North Genematas Drive, Tucson, AZ 85704 (United States); Kubley, Thomas [Department of Physics and Astronomy and Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Caffee, Marc [Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907 (United States); Department of Physics and Astronomy and Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States)

    2015-10-15

    Current extraction methods for in situ {sup 14}C from quartz [e.g., Lifton et al., (2001), Pigati et al., (2010), Hippe et al., (2013)] are time-consuming and repetitive, making them an attractive target for automation. We report on the status of in situ {sup 14}C extraction and purification systems originally automated at the University of Arizona that have now been reconstructed and upgraded at the Purdue Rare Isotope Measurement Laboratory (PRIME Lab). The Purdue in situ {sup 14}C laboratory builds on the flow-through extraction system design of Pigati et al. (2010), automating most of the procedure by retrofitting existing valves with external servo-controlled actuators, regulating the pressure of research purity O{sub 2} inside the furnace tube via a PID-based pressure controller in concert with an inlet mass flow controller, and installing an automated liquid N{sub 2} distribution system, all driven by LabView® software. A separate system for cryogenic CO{sub 2} purification, dilution, and splitting is also fully automated, ensuring a highly repeatable process regardless of the operator. We present results from procedural blanks and an intercomparison material (CRONUS-A), as well as results of experiments to increase the amount of material used in extraction, from the standard 5 g to 10 g or above. Results thus far are quite promising with procedural blanks comparable to previous work and significant improvements in reproducibility for CRONUS-A measurements. The latter analyses also demonstrate the feasibility of quantitative extraction of in situ {sup 14}C from sample masses up to 10 g. Our lab is now analyzing unknowns routinely, but lowering overall blank levels is the focus of ongoing research.

  2. Accelerator mass spectrometry measurements of the 13C (n ,γ )14C and 14N(n ,p )14C cross sections

    Science.gov (United States)

    Wallner, A.; Bichler, M.; Buczak, K.; Dillmann, I.; Käppeler, F.; Karakas, A.; Lederer, C.; Lugaro, M.; Mair, K.; Mengoni, A.; Schätzel, G.; Steier, P.; Trautvetter, H. P.

    2016-04-01

    The technique of accelerator mass spectrometry (AMS), offering a complementary tool for sensitive studies of key reactions in nuclear astrophysics, was applied for measurements of the 13C (n ,γ )14C and the 14N(n ,p )14C cross sections, which act as a neutron poison in s -process nucleosynthesis. Solid samples were irradiated at Karlsruhe Institute of Technology with neutrons closely resembling a Maxwell-Boltzmann distribution for k T =25 keV, and also at higher energies between En=123 and 182 keV. After neutron irradiation the produced amount of 14C in the samples was measured by AMS at the Vienna Environmental Research Accelerator (VERA) facility. For both reactions the present results provide important improvements compared to previous experimental data, which were strongly discordant in the astrophysically relevant energy range and missing for the comparably strong resonances above 100 keV. For 13C (n ,γ ) we find a four times smaller cross section around k T =25 keV than a previous measurement. For 14N(n ,p ), the present data suggest two times lower cross sections between 100 and 200 keV than had been obtained in previous experiments and data evaluations. The effect of the new stellar cross sections on the s process in low-mass asymptotic giant branch stars was studied for stellar models of 2 M⊙ initial mass, and solar and 1 /10th solar metallicity.

  3. Biodegradation of {sup 14} C-atrazine under outdoor conditions; Biodegradacao de {sup 14} C-atrazina em condicoes semi controladas

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Brigida Pimentel Villar de

    1997-10-01

    Uniformly {sup 14} C-ring labeled atrazine (5 L/ha) was applied to a Typical Hapludox Brazilian Soil sample which was incubated under outdoor conditions. Sample of 200 g (dry weight base) of fresh soil were distributed in Erlenmeyer flasks and the moisture was adjusted for 2/3 rds of the soil field capacity. The flasks were then buried in the Lysimeter Station when they were incubated. The experiment started jointly with a corn planting. The {sup 14} C O{sub 2} was analyzed every 15 day, during a period of 150 days. The desorbed, extracted and bound residues were analyzed. The extracted soil was fractionated and the residues in the humin, fulvic and humic acids were determined. At the end of the incubation period (150 days), the {sup 14} CO{sub 2} evolved reached up to 36% of the total applied activity, the bound residues were detected in about the same (34%) during the inoculation period, and were distributed in the fractions of fulvic acids (29,91%), humic acids (6,83%) and humin (63,26%). The metabolites formed in the desorbed residues and in the extracted residues were determined using thin layer chromatography with {sup 14} C-detector. After 150 days incubation, desorbed soil residues were identified as atrazine (52,72%), hydroxiatrazine (44%) and desisopropilatrazine (3,28%). The extractable residues contained atrazine (79,29%), hydroxiatrazine (16,22%), desisopropilatrazine (2,25%) and desetylatrazine (2,24%). (author)

  4. Influence of hydroxypropyl-beta-cyclodextrin on the biodegradation of {sup 14}C-phenanthrene and {sup 14}C-hexadecane in soil

    Energy Technology Data Exchange (ETDEWEB)

    Stroud, Jacqueline L.; Tzima, Marina [Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom); Paton, Graeme I. [School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU (United Kingdom); Remedios Ltd, Aberdeen Science and Technology Park, Aberdeen AB22 8GW (United Kingdom); Semple, Kirk T., E-mail: k.semple@lancaster.ac.u [Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom)

    2009-10-15

    Soil was spiked with [9-{sup 14}C]phenanthrene and [1-{sup 14}C]hexadecane at 50 mg kg{sup -1} and aged for 1, 25, 50, 100 and 250 d. At each time point, the microcosms were amended with aqueous solutions of cyclodextrin (HP-beta-CD) at a range of concentrations (0-40 mM). Mineralisation assays and aqueous HP-beta-CD extractions were performed to assess the effect of the amendments on microbial degradation. The results showed that amendments had no significant impact on the microbial degradation of either of the {sup 14}C-contaminants. Further, HP-beta-CD extractions were correlated with the mineralisation of the target chemicals in each of the soil conditions. It was found that the HP-beta-CD extraction was able to predict mineralisation in soils which had not been amended with cyclodextrin; however, in the soils containing the HP-beta-CD, there was no predictive relationship. Under the conditions of this study, the introduction of HP-beta-CD into soils did not enhance the biodegradation of the organic contaminants. - The amendment of HP-beta-CD to phenanthrene and hexadecane amended soils does not enhance microbial biodegradation.

  5. Hydrocarbons in the millipede Graphidostreptus tumuliporus (Karsch) (Myriapoda: Diplopoda)—I. In vivo incorporation of 14C-labelled precursors into the hydrocarbon fraction

    NARCIS (Netherlands)

    Oudejans, R.C.H.M.

    1972-01-01

    1. 1. Biosynthesis of hydrocarbons in male and female specimens of the millipede Graphidostreptus tumuliporus was investigated after injection of the following precursors: 1-14C-acetate, 16-14C- and 1-14C-palmitic acid, isoleucine-14C(U), valine-14C(U) and mevalonic-2-14C acid. 2. 2. Both sexes are

  6. Hydrocarbons in the millipede Graphidostreptus tumuliporus (Karsch) (Myriapoda: Diplopoda)—I. In vivo incorporation of 14C-labelled precursors into the hydrocarbon fraction

    NARCIS (Netherlands)

    Oudejans, R.C.H.M.

    1972-01-01

    1. 1. Biosynthesis of hydrocarbons in male and female specimens of the millipede Graphidostreptus tumuliporus was investigated after injection of the following precursors: 1-14C-acetate, 16-14C- and 1-14C-palmitic acid, isoleucine-14C(U), valine-14C(U) and mevalonic-2-14C acid. 2. 2. Both sexes

  7. Constraining processes of landscape change with combined in situ cosmogenic 14C-10Be analysis

    Science.gov (United States)

    Hippe, Kristina

    2017-10-01

    Reconstructing Quaternary landscape evolution today frequently builds upon cosmogenic-nuclide surface exposure dating. However, the study of complex surface exposure chronologies on the 102-104 years' timescale remains challenging with the commonly used long-lived radionuclides (10Be, 26Al, 36Cl). In glacial settings, key points are the inheritance of nuclides accumulated in a rock surface during a previous exposure episode and (partial) shielding of a rock surface after the main deglaciation event, e.g. during phases of glacier readvance. Combining the short-lived in situ cosmogenic 14C isotope with 10Be dating provides a valuable approach to resolve and quantify complex exposure histories and burial episodes within Lateglacial and Holocene timescales. The first studies applying the in situ14C-10Be pair have demonstrated the great benefit from in situ14C analysis for unravelling complex glacier chronologies in various glacial environments worldwide. Moreover, emerging research on in situ14C in sedimentary systems highlights the capacity of combined in situ14C-10Be analysis to quantify sediment transfer times in fluvial catchments or to constrain changes in surface erosion rates. Nevertheless, further methodological advances are needed to obtain truly routine and widely available in situ14C analysis. Future development in analytical techniques has to focus on improving the analytical reproducibility, reducing the background level and determining more accurate muonic production rates. These improvements should allow extending the field of applications for combined in situ14C-10Be analysis in Earth surface sciences and open up a number of promising applications for dating young sedimentary deposits and the quantification of recent changes in surface erosion dynamics.

  8. HUMAN MASS BALANCE STUDY OF TAS-102 USING 14C ANALYZED BY ACCELERATOR MASS SPECTROMETRY

    Science.gov (United States)

    Lee, James J.; Seraj, Jabed; Yoshida, Kenichiro; Mizuguchi, Hirokazu; Strychor, Sandra; Fiejdasz, Jillian; Faulkner, Tyeler; Parise, Robert A.; Fawcett, Patrick; Pollice, Laura; Mason, Scott; Hague, Jeremy; Croft, Marie; Nugteren, James; Tedder, Charles; Sun, Weijing; Chu, Edward; Beumer, Jan Hendrik

    2016-01-01

    Background TAS-102 is an oral fluoropyrimidine prodrug composed of trifluridine (FTD) and tipiracil hydrochloride (TPI) in a 1:0.5 ratio. FTD is a thymidine analog, and it is degraded by thymidine phosphorylase (TP) to the inactive trifluoromethyluracil (FTY) metabolite. TPI inhibits degradation of FTD by TP, increasing systemic exposure to FTD. Methods Patients with advanced solid tumors (6 M/2 F; median age 58 years; PS 0–1) were enrolled on this study. Patients in group A (N = 4) received 60 mg TAS-102 with 200 nCi [14C]-FTD, while patients in group B (N = 4) received 60 mg TAS-102 with 1000 nCi [14C]-TPI orally. Plasma, blood, urine, feces, and expired air (group A only) were collected up to 168 h, and were analyzed for 14C by accelerator mass spectrometry and analytes by LC-MS/MS. Results FTD: 59.8% of the 14C dose was recovered; 54.8% in urine mostly as FTY and FTD glucuronide isomers. The extractable radioactivity in the pooled plasma consisted of 52.7% FTD and 33.2% FTY. TPI: 76.8% of the 14C dose was recovered; 27.0% in urine mostly as TPI, and 49.7% in feces. The extractable radioactivity in the pooled plasma consisted of 53.1% TPI and 30.9% 6-HMU, the major metabolite of TPI. Conclusion Absorbed 14C-FTD was metabolized and mostly excreted in urine. The majority of 14C-TPI was recovered in feces, and the majority of absorbed TPI was excreted in urine. The current data with the ongoing hepatic and renal dysfunction studies will provide an enhanced understanding of the TAS-102 elimination profile. PMID:26787503

  9. Human mass balance study of TAS-102 using (14)C analyzed by accelerator mass spectrometry.

    Science.gov (United States)

    Lee, James J; Seraj, Jabed; Yoshida, Kenichiro; Mizuguchi, Hirokazu; Strychor, Sandra; Fiejdasz, Jillian; Faulkner, Tyeler; Parise, Robert A; Fawcett, Patrick; Pollice, Laura; Mason, Scott; Hague, Jeremy; Croft, Marie; Nugteren, James; Tedder, Charles; Sun, Weijing; Chu, Edward; Beumer, Jan Hendrik

    2016-03-01

    TAS-102 is an oral fluoropyrimidine prodrug composed of trifluridine (FTD) and tipiracil hydrochloride (TPI) in a 1:0.5 ratio. FTD is a thymidine analog, and it is degraded by thymidine phosphorylase (TP) to the inactive trifluoromethyluracil (FTY) metabolite. TPI inhibits degradation of FTD by TP, increasing systemic exposure to FTD. Patients with advanced solid tumors (6 M/2 F; median age 58 years; PS 0-1) were enrolled on this study. Patients in group A (N = 4) received 60 mg TAS-102 with 200 nCi [(14)C]-FTD, while patients in group B (N = 4) received 60 mg TAS-102 with 1000 nCi [(14)C]-TPI orally. Plasma, blood, urine, feces, and expired air (group A only) were collected up to 168 h and were analyzed for (14)C by accelerator mass spectrometry and analytes by LC-MS/MS. FTD: 59.8% of the (14)C dose was recovered: 54.8% in urine mostly as FTY and FTD glucuronide isomers. The extractable radioactivity in the pooled plasma consisted of 52.7% FTD and 33.2% FTY. TPI: 76.8% of the (14)C dose was recovered: 27.0% in urine mostly as TPI and 49.7% in feces. The extractable radioactivity in the pooled plasma consisted of 53.1% TPI and 30.9% 6-HMU, the major metabolite of TPI. Absorbed (14)C-FTD was metabolized and mostly excreted in urine. The majority of (14)C-TPI was recovered in feces, and the majority of absorbed TPI was excreted in urine. The current data with the ongoing hepatic and renal dysfunction studies will provide an enhanced understanding of the TAS-102 elimination profile.

  10. Periodicity in Delta-modulated feedback control

    Institute of Scientific and Technical Information of China (English)

    Xiaohua XIA; Guanrong CHEN; Rudong GAI; Alan S. I. ZINOBER

    2008-01-01

    The Delta-modulated feedback control of a linear system introduces nonlinearity into the system through switchings between two input values. It has been found that Delta-modulation gives rise to periodic orbits. The existence of periodic points of all orders of Sigma-Delta modulation with "leaky" integration is completely characterized by some interesting groups of polynomials with "sign" coefficients. The results are naturally generalized to Sigma-Delta modulations with multiple delays, Delta-modulations in the "downlink", unbalanced Delta-modulations and systems with two-level quantized feedback. Further extensions relate to the existence of periodic points arising from Delta-modulated feedback control of a stable linear system in an arbitrary direction, for which some necessary and sufficient conditions are given.

  11. /sup 14/C isotope effects in /sup 1/H and /sup 13/C N. M. R. spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Funke, C.W.; Kaspersen, F.M.; Sperling, E.M.G.; Wagenaars, G.N.

    1986-03-15

    Replacement of /sup 12/C by /sup 14/C induces small upfield shifts of the directly bonded /sup 1/H and /sup 13/C nuclei; these shift differences can be used to measure the extent of /sup 14/C labelling.

  12. Low-level 14C methane oxidation rate measurements modified for remote field settings

    Science.gov (United States)

    Pack, M. A.; Pohlman, J.; Ruppel, C. D.; Xu, X.

    2012-12-01

    Aerobic methane oxidation limits atmospheric methane emissions from degraded subsea permafrost and dissociated methane hydrates in high latitude oceans. Methane oxidation rate measurements are a crucial tool for investigating the efficacy of this process, but are logistically challenging when working on small research vessels in remote settings. We modified a low-level 14C-CH4 oxidation rate measurement for use in the Beaufort Sea above hydrate bearing sediments during August 2012. Application of the more common 3H-CH4 rate measurement that uses 106 times more radioactivity was not practical because the R/V Ukpik cannot accommodate a radiation van. The low-level 14C measurement does not require a radiation van, but careful isolation of the 14C-label is essential to avoid contaminating natural abundance 14C measurements. We used 14C-CH4 with a total activity of 1.1 μCi, which is far below the 100 μCi permitting level. In addition, we modified field procedures to simplify and shorten sample processing. The original low-level 14C-CH4 method requires 6 steps in the field: (1) collect water samples in glass serum bottles, (2) inject 14C-CH4 into bottles, (3) incubate for 24 hours, (4) filter to separate the methanotrophic bacterial cells from the aqueous sample, (5) kill the filtrate with sodium hydroxide (NaOH), and (6) purge with nitrogen to remove unused 14C-CH4. Onshore, the 14C-CH4 respired to carbon dioxide or incorporated into cell material by methanotrophic bacteria during incubation is quantified by accelerator mass spectrometry (AMS). We conducted an experiment to test the possibility of storing samples for purging and filtering back onshore (steps 4 and 6). We subjected a series of water samples to steps 1-3 & 5, and preserved with mercuric chloride (HgCl2) instead of NaOH because HgCl2 is less likely to break down cell material during storage. The 14C-content of the carbon dioxide in samples preserved with HgCl2 and stored for up to 2 weeks was stable

  13. Release of aged 14C-atrazine residues from soil facilitated by dry-wet cycles

    Science.gov (United States)

    Jablonowski, N. D.; Yu, K.; Koeppchen, S.; Burauel, P.

    2012-04-01

    Intermittent dry-wet cycles may have an important effect on soil structure and aged pesticide residues release (1). A laboratory study was conducted to assess the maximum potential of water extractable aged atrazine residues influenced by soil drying and wetting. The used soil was obtained from an outdoor lysimeter (gleyic cambisol; Corg: 1.45%), containing environmentally aged (22 years) 14C-atrazine residues. For the experiment, soil from 0-10 cm depth was used since most residual 14C activity was previously found in this layer (2,3). Triplicate soil samples with a residual water content of approx. 8% were either dried (45° C) prior water addition or directly mixed with distilled water (soil+water: 1+2, w:w). The samples were shaken (150 rmp, 60 min, at 21° C), centrifuged (approx. 2000 g), and the supernatants were filtered. Water-extracted residual 14C activity was detected via liquid scintillation counter. The total water-extracted 14C activity (the amount of residual 14C activity in a sample equals 100%) was significantly higher (p

  14. Autophagic sequestration of [14C]sucrose, introduced into rat hepatocytes by reversible electro-permeabilization.

    Science.gov (United States)

    Gordon, P B; Seglen, P O

    1982-11-01

    Isolated rat hepatocytes could be made permeable to small molecules such as [14C]sucrose (but not to proteins) by subjecting the cells to repeated electric discharges in a high-voltage field. During subsequent incubation at 37 degrees C, the permeability changes were reversed within 15 min, the electro-injected [14C]sucrose remaining trapped inside the re-sealed plasma membrane. Autophagic sequestration of [14C]sucrose, i.e., the transfer of radioactivity from cytosol to sedimentable vesicles (autophagosomes and lysosomes), could be followed by incubating the [14C]sucrose-loaded hepatocytes for up to 2 h at 37 degrees C. After incubation, the cells were disrupted by a single high-voltage discharge in electrolyte-free medium (sucrose), and sedimentable cell components were separated from the cytosol by centrifugation through metrizamide. By the use of these methods, which are particularly suitable for the analysis of many small cell samples, it could be shown that [14C]sucrose was autophagically sequestered in the hepatocytes at a rate of 4-5%/h. The sequestration was nearly completely inhibited by the specific autophagy inhibitor 3-methyladenine.

  15. Modulation of (14) C-labeled glucose metabolism by zinc during aluminium induced neurodegeneration.

    Science.gov (United States)

    Singla, Neha; Dhawan, D K

    2015-09-01

    Aluminium (Al) is one of the most prominent metals in the environment and is responsible for causing several neurological disorders, including Alzheimer's disease. On the other hand, zinc (Zn) is an essential micronutrient that is involved in regulating brain development and function. The present study investigates the protective potential of Zn in the uptake of (14) C-labeled amino acids and glucose and their turnover in rat brain slices during Al intoxication. Male Sprague Dawley rats (140-160 g) were divided into four different groups: normal control, Al treated (100 mg/kg body weight/day via oral gavage), Zn treated (227 mg/liter in drinking water), and Al + Zn treated. Radiorespirometric assay revealed an increase in glucose turnover after Al exposure that was attenuated after Zn treatment. Furthermore, the uptake of (14) C-labeled glucose was increased after Al treatment but was appreciably decreased upon Zn supplementation. In addition, the uptakes of (14) C-lysine, (14) C-leucine, and (14) C-aspartic acid were also found to be elevated following Al exposure but were decreased after Zn treatment. Al treatment also caused alterations in the neurohistoarchitecture of the brain, which were improved after Zn coadministration. Therefore, the present study suggests that Zn provides protection against Al-induced neurotoxicity by regulating glucose and amino acid uptake in rats, indicating that Zn could be a potential candidate for the treatment of various neurodegenerative disorders.

  16. Probable alpha and $14$^C cluster emission from hyper Ac nuclei

    CERN Document Server

    Santhosh, K P

    2013-01-01

    A systematic study on the probability for the emission of 4^He and 14^C cluster from hyper ${207-234}^$Ac and non-strange normal ${207-234}^$Ac nuclei are performed for the first time using our fission model, the Coulomb and proximity potential model (CPPM). The predicted half lives show that hyper ${207-234}^$Ac nuclei are unstable against 4^He emission and 14^C emission from hyper ${217-228}^$Ac are favorable for measurement. Our study also show that hyper ${207-234}^$Ac are stable against hyper 4^He and 14^C emission. The role of neutron shell closure (N=126) in hyper 214^Fr daughter and role of proton/ neutron shell closure (Z =82, N =126) in hyper 210^Bi daughter are also revealed. As hyper-nuclei decays to normal nuclei by mesonic/non-mesonic decay and since most of the predicted half lives for 4^He and 14^C emission from normal Ac nuclei are favourable for measurement, we presume that alpha and 14^C cluster emission from hyper Ac nuclei can be detected in laboratory in a cascade (two-step) process.

  17. Probable alpha and {sup 14}C cluster emission from hyper Ac nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P. [Kannur University, Swami Anandatheertha Campus, School of Pure and Applied Physics, Payyanur (India)

    2013-10-15

    A systematic study on the probability for the emission of {sup 4}He and {sup 14}C cluster from hyper {sub {Lambda}}{sup 207-234}Ac and non-strange normal {sup 207-234}Ac nuclei are performed for the first time using our fission model, the Coulomb and proximity potential model (CPPM). The predicted half lives show that hyper {sub {Lambda}}{sup 207-234}Ac nuclei are unstable against {sup 4}He emission and {sup 14}C emission from hyper {sub {Lambda}}{sup 217-228}Ac are favorable for measurement. Our study also show that hyper {sub {Lambda}}{sup 207-234}Ac are stable against hyper {sub {Lambda}}{sup 4}He and {sub {Lambda}}{sup 14}C emission. The role of neutron shell closure (N = 126) in hyper {sub {Lambda}}{sup 214}Fr daughter and role of proton/neutron shell closure (Z {approx} 82, N = 126) in hyper {sub {Lambda}}{sup 210}Bi daughter are also revealed. As hyper-nuclei decays to normal nuclei by mesonic/non-mesonic decay and since most of the predicted half lives for {sup 4}He and {sup 14}C emission from normal Ac nuclei are favourable for measurement, we presume that alpha and {sup 14}C cluster emission from hyper Ac nuclei can be detected in laboratory in a cascade (two-step) process. (orig.)

  18. Decomposition of /sup 14/C-labelled lignin, holocellulose and lignocellulose by mycorrhizal fungi

    Energy Technology Data Exchange (ETDEWEB)

    Trojanowski, J.; Huettermann, A.; Haider, K.

    1984-01-01

    Five different species of known ecto-mycorrhizal fungi: Cenococcum geophilum, Amanita muscaria, Tricholoma aurantium, Rhizopogon luteolus and Rhizopogon roseolus were studied for their ability to metabolize the major components of plant cell walls. All strains were able to decompose /sup 14/C-labelled plant lignin, /sup 14/C-lignocellulose and /sup 14/C-DHP-lignin at a rate which was lower than the one observed for the known white rot fungi Heterobasidion annosum and Sporotrichum pulverulentum. Also /sup 14/C-(U)-holocellulose was relatively less degradable for the mycorrhizal fungi than for the white rotters. On the other hand, aromatic monomers like /sup 14/C-vanillic acid were decomposed to a much higher extent by two species of mycorrhizal fungi compared to the activity observed for Heterobasidion annosum. The results of the experiments reveal that these stains of mycorrhizal fungi are well able to utilize the major components of plant material and thus can contribute to litter decomposition in the forest floor.

  19. Variations of 14-C around AD 775 and AD 1795 - due to solar activity

    CERN Document Server

    Neuhaeuser, Ralph

    2015-01-01

    The motivation for our study is the disputed cause for the strong variation of 14-C around AD 775. Our method is to compare the 14-C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14-C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14-C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14-C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects...

  20. A study of the carbon dynamics of Japanese grassland and forest using 14C and 13C

    Science.gov (United States)

    Katsuno, Kazumi; Miyairi, Yosuke; Tamura, Kenji; Matsuzaki, Hiroyuki; Fukuda, Kenji

    2010-04-01

    We quantified the carbon contents of grassland and forest soil using conventional methods and studied the changes in their dynamics by measuring δ 13C and Δ 14C. Soil samples were taken from a neighboring Miscanthus sinensis grassland and Pinus densiflora forest in central Japan. Both had been maintained as grassland until the 1960s, when the latter was abandoned and became a pine forest by natural succession. The soil carbon content of the forest was much lower than that of the grassland, implying that the soil carbon decreased as the grassland became forest. The δ 13C values were very similar in the grassland and forest, at approximately -20‰, suggesting that M. sinensis (a C4 plant) contributed to carbon storage, whereas there was little carbon accumulation from P. densiflora (a C3 plant) in forest soil. The Δ 14C values and calculated soil carbon mean residence time (MRT) showed that the soil carbon in the upper A horizon was older, and that in the lower A horizon was younger in forest than in grassland. From these results, we conclude that young, fast-MRT soil carbon is decomposed in the upper A horizon, and old, stable soil carbon was decomposed in the lower A horizon after the pine invasion.

  1. Atmospheric Fossil Fuel CO2 Tracing By 14C In Some Chinese Cities

    Science.gov (United States)

    Zhou, W.; Niu, Z.; Zhu, Y., Sr.

    2016-12-01

    CO2 plays an important role in global climate as a primary greenhouse gas in the atmosphere. Moreover, it has been shown that more than 70% of global fossil fuel CO2 (CO2ff) emissions are concentrated in urban areas (Duren and Miller, 2012). Our study focuses on atmospheric CO2ff concentrations in 15 Chinese cities using accelerator mass spectrometer (AMS) to measure 14C. Our objectives are: (1) to document atmospheric CO2ff concentrations in a variety of urban environments, (2) to differentiate the spatial-temporal variations in CO2ff among these cities, and (3) to ascertain the factors that control the observed variations. For about two years (winter 2014 to winter 2016), the CO2ff concentrations we observed from all sites varied from 5.1±4.5 ppm to 65.8±39.0 ppm. We observed that inland cities display much higher CO2ff concentrations and overall temporal variations than coastal cities in winter, and that northern cities have higher CO2ff concentrations than those of southern cities in winter. For inland cities relatively high CO2ff values are observed in winter and low values in summer; while seasonal variations are not distinct in the coastal cities. No significant (p > 0.05) differences in CO2ff values are found between weekdays and weekends as was shown previously in Xi'an (Zhou et al., 2014). Diurnal CO2ff variations are plainly evident, with high values between midnight and 4:00 am, and during morning and afternoon rush hours (Niu et al., 2016). The high CO2ff concentrations in northern inland cities in winter results mainly from the substantial consumption of fossil fuels for heating. The high CO2ff concentrations seen in diurnal measurements result mainly from variations in atmospheric dispersion, and from vehicle emissions related to traffic flows. The inter-annual variations in CO2ff in cities could provide a useful reference for local governments to develop policy around the effect of energy conservation and emission reduction strategies.

  2. A Minute Dose of 14C-b-Carotene is Absorbed and Converted to Retinoids in Humans

    Science.gov (United States)

    We dosed 8 adults with 14C-all-trans [10,10',11,11'-14C]-B-carotene (1.01 nmol) to quantify its absorption and metabolism. We used accelerator mass spectrometry (AMS) to measure 14C eliminated in feces over 14 days, in urine over 30 days, and that was retained in plasma over 166 days since dose. We...

  3. Seasonal variations and sources of ambient fossil and biogenic-derived carbonaceous aerosols based on 14C measurements in Lhasa, Tibet

    Science.gov (United States)

    Huang, Jie; Kang, Shichang; Shen, Chengde; Cong, Zhiyuan; Liu, Kexin; Wang, Wei; Liu, Lichao

    2010-06-01

    A total of 30 samples of total suspended particles were collected at an urban site in Lhasa, Tibet from August 2006 to July 2007 for investigating carbonaceous aerosol features. The fractions of contemporary carbon ( fc) in total carbon (TC) of ambient aerosols are presented using radiocarbon ( 14C) measurements. The value of fc represents the biogenic contribution to TC, as the biosphere releases organic compounds with the present 14C/ 12C level ( fc = 1), whereas 14C has become extinct in anthropogenic emissions of fossil carbon ( fc = 0). The fc values in Lhasa ranging from 0.357 to 0.702, are higher than Beijing and Tokyo, but clearly lower than the rural region of Launceston, which indicates a major biogenic influence in Lhasa. Seasonal variations of fc values corresponded well with variations of pollutants concentrations (e.g. NO 2). Higher fc values appeared in winter indicating carbonaceous aerosol is more dominated by wood burning and incineration of agricultural wastes within this season. The lower fc values in summer and autumn may be caused by increased diesel and petroleum emissions related to tourism in Lhasa. δ13C values ranged from - 26.40‰ to - 25.10‰, with relative higher values in spring and summer, reflecting the increment of fossil carbon emissions.

  4. Degradation of Triazine-2-(14C Metsulfuron-Methyl in Soil from an Oil Palm Plantation.

    Directory of Open Access Journals (Sweden)

    B S Ismail

    Full Text Available Triazine-2-(14C metsulfuron-methyl is a selective, systemic sulfonylurea herbicide. Degradation studies in soils are essential for the evaluation of the persistence of pesticides and their breakdown products. The purpose of the present study was to investigate the degradation of triazine-2-(14C metsulfuron-methyl in soil under laboratory conditions. A High Performance Liquid Chromatograph (HPLC equipped with an UV detector and an on-line radio-chemical detector, plus a Supelco Discovery column (250 x 4.6 mm, 5 μm, and PRP-1 column (305 x 7.0 mm, 10 μm was used for the HPLC analysis. The radioactivity was determined by a Liquid Scintillation Counter (LSC in scintillation fluid. The soil used was both sterilized and non-sterilized in order to observe the involvement of soil microbes. The estimated DT50 and DT90 values of metsulfuron-methyl in a non-sterile system were observed to be 13 and 44 days, whereas in sterilized soil, the DT50 and DT90 were 31 and 70 days, respectively. The principal degradation product after 60 days was CO2. The higher cumulative amount of (14CO2 in (14C-triazine in the non-sterilized soil compared to that in the sterile system suggests that biological degradation by soil micro-organisms significantly contributes to the dissipation of the compound. The major routes of degradation were O-demethylation, sulfonylurea bridge cleavage and the triazine "ring-opened."

  5. Degradation of Triazine-2-14C Metsulfuron–Methyl in Soil from an Oil Palm Plantation

    Science.gov (United States)

    B. S., Ismail

    2015-01-01

    Triazine-2-14C metsulfuron–methyl is a selective, systemic sulfonylurea herbicide. Degradation studies in soils are essential for the evaluation of the persistence of pesticides and their breakdown products. The purpose of the present study was to investigate the degradation of triazine-2-14C metsulfuron–methyl in soil under laboratory conditions. A High Performance Liquid Chromatograph (HPLC) equipped with an UV detector and an on-line radio-chemical detector, plus a Supelco Discovery column (250 x 4.6 mm, 5 μm), and PRP–1 column (305 x 7.0 mm, 10 μm) was used for the HPLC analysis. The radioactivity was determined by a Liquid Scintillation Counter (LSC) in scintillation fluid. The soil used was both sterilized and non-sterilized in order to observe the involvement of soil microbes. The estimated DT50 and DT90 values of metsulfuron-methyl in a non-sterile system were observed to be 13 and 44 days, whereas in sterilized soil, the DT50 and DT90 were 31 and 70 days, respectively. The principal degradation product after 60 days was CO2. The higher cumulative amount of 14CO2 in 14C- triazine in the non-sterilized soil compared to that in the sterile system suggests that biological degradation by soil micro-organisms significantly contributes to the dissipation of the compound. The major routes of degradation were O-demethylation, sulfonylurea bridge cleavage and the triazine “ring-opened.” PMID:26437264

  6. Comparison of Varve and 14C Chronologies from Steel Lake, Minnesota, USA

    Energy Technology Data Exchange (ETDEWEB)

    Tian, J; Brown, T A; Hu, F S

    2004-12-29

    Annually laminated sediments (varves) offer an effective means of acquiring high-quality paleoenvironmental records. However, the strength of a varve chronology can be compromised by a number of factors, such as missing varves, ambiguous laminations, and human counting error. We assess the quality of a varve chronology for the last three millennia from Steel Lake, Minnesota, through comparisons with nine AMS {sup 14}C dates on terrestrial plant macrofossils from the same core. These comparisons revealed an overall 8.4% discrepancy, primarily because of missing/uncountable varves within two stratigraphic intervals characterized by low carbonate concentrations and obscure laminations. Application of appropriate correction factors to these two intervals results in excellent agreement between the varve and {sup 14}C chronologies. These results, together with other varve studies, demonstrate that an independent age-determination method, such as {sup 14}C dating, is usually necessary to verify, and potentially correct, varve chronologies.

  7. In vitro covalent binding of /sup 14/C-mibolerone to rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Jaglan, P.S.

    1986-01-01

    Mibolerone (17-Hydroxy-7,17-dimethylestr-4-en-3-one; 7 alpha-17 alpha dimethyl-19-nortestosterone) is being marketed by The Upjohn Company for the inhibition of estrus in bitches. The aim of this study was to determine the extent of covalent binding of mibolerone to rat liver microsomes. Liver microsomes were obtained from Control and phenobarbitol-treated female Fisher rats, and were incubated with /sup 14/C-mibolerone at 37/sup 0/C for 10 minutes. No covalent binding to macromolecules was observed when /sup 14/C-mibolerone was incubated with rat liver microsomes. Under identical conditions, /sup 14/C-estradiol was covalently bound to macromolecules. Slightly higher covalent binding of estradiol was observed with microsomes from phenobarbitol-treated rats. Ascorbic acid and glutathione inhibited covalent binding of estradiol to macromolecules in the in vitro microsomal system.

  8. {sup 36}Cl and {sup 14}C behaviour in UNGG graphite during leaching experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, C.; Guy, C.; Comte, J. [Commissariat a l' Energie Atomique - C.E.A., Laboratoire d' Analyses Radiochimiques et Chimiques (L.A.R.C.) 13108 Saint Paul lez Durance (France)

    2008-07-01

    Graphite has been used as a moderator in Natural Uranium Graphite Gas reactors. Among the radionuclides, the long-lived activation product {sup 36}Cl and {sup 14}C, which are abundant in graphite after irradiation can be the main contributors to the dose during disposal. This paper deals with the first results obtained on irradiated graphite from French G2 reactor. Both leaching and diffusion experiments have been performed in order to understand and quantify the radionuclides behaviour. Chlorine leaching seems to be controlled by diffusion transport through graphite matrix. On the contrary {sup 14}C leaching is very low, probably because after irradiation, the remaining {sup 14}C was produced from {sup 13}C activation in the crystalline structure of graphite. (authors)

  9. Differences in ( sup 14 C)glycerol utilization in normal and familial hypercholesterolemic fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Shireman, R.B.; Durieux, J. (Univ. of Florida Gainesville (USA))

    1991-01-01

    It is known that cultured fibroblasts from familial hypercholesterolemia (FH) patients lack the normal cell receptor for low density lipoprotein (LDL) and that the absence of receptor-mediated transport of LDL cholesterol into these cells results in increased cellular synthesis of cholesterol. After 20 h perincubation in lipid-free medium, cultured FH fibroblasts incorporated significantly greater amounts of ({sup 14}C)glycerol into cellular lipids than did normal fibroblasts. Relative to the control medium which contained only bovine serum albumin (BSA), preincubation with 5% fetal bovine serum or 50 micrograms LDL/ml decreased ({sup 14}C)glycerol incorporation by both cell types. FH cells utilized more ({sup 14}C)glycerol for phospholipid synthesis and less for triglyceride synthesis than normal cells. This study indicates that LDL may be important in the transport of glycerides, as well as cholesterol, to cells.

  10. XCAMS: The compact {sup 14}C accelerator mass spectrometer extended for {sup 10}Be and {sup 26}Al at GNS Science, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Zondervan, A., E-mail: a.zondervan@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); Hauser, T.M. [National Electrostatics Corporation, Middleton, WI (United States); Kaiser, J. [GNS Science, Lower Hutt (New Zealand); Kitchen, R.L. [National Electrostatics Corporation, Middleton, WI (United States); Turnbull, J.C.; West, J.G. [GNS Science, Lower Hutt (New Zealand)

    2015-10-15

    Highlights: • We review the performance of a 0.5 MV AMS system for {sup 10}Be, {sup 14}C, and {sup 26}Al. • We identify the limiting factors to {sup 10}Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for {sup 10}Be, {sup 14}C, {sup 26}Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact {sup 14}C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for {sup 10}Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, {sup 14}C Poisson and non-Poisson errors, and {sup 10}Be detection limit and sensitivity. Operational details and hardware improvements, such as {sup 10}Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised {sup 14}C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of {sup 14}C measurement. For {sup 10}Be, the limit of detection in terms of the isotopic abundance ratio {sup 10}Be/{sup 9}Be is 6 × 10{sup −15} at at{sup −1} and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  11. Disposition and metabolic profiling of [(14)C]cerlapirdine using accelerator mass spectrometry.

    Science.gov (United States)

    Tse, Susanna; Leung, Louis; Raje, Sangeeta; Seymour, Mark; Shishikura, Yoko; Obach, R Scott

    2014-12-01

    Cerlapirdine (SAM-531, PF-05212365) is a selective, potent, full antagonist of the 5-hydroxytryptamine 6 (5-HT6) receptor. Cerlapirdine and other 5-HT6 receptor antagonists have been in clinical development for the symptomatic treatment of Alzheimer's disease. A human absorption, distribution, metabolism, and excretion study was conducted to gain further understanding of the metabolism and disposition of cerlapirdine. Because of the low amount of radioactivity administered, total (14)C content and metabolic profiles in plasma, urine, and feces were determined using accelerator mass spectrometry (AMS). After a single, oral 5-mg dose of [(14)C]cerlapirdine (177 nCi), recovery of total (14)C was almost complete, with feces being the major route of elimination of the administered dose, whereas urinary excretion played a lesser role. The extent of absorption was estimated to be at least 70%. Metabolite profiling in pooled plasma samples showed that unchanged cerlapirdine was the major drug-related component in circulation, representing 51% of total (14)C exposure in plasma. One metabolite (M1, desmethylcerlapirdine) was detected in plasma, and represented 9% of the total (14)C exposure. In vitro cytochrome P450 reaction phenotyping studies showed that M1 was formed primarily by CYP2C8 and CYP3A4. In pooled urine samples, three major drug-related peaks were detected, corresponding to cerlapirdine-N-oxide (M3), cerlapirdine, and desmethylcerlapirdine. In feces, cerlapirdine was the major (14)C component excreted, followed by desmethylcerlapirdine. The results of this study demonstrate that the use of the AMS technique enables comprehensive quantitative elucidation of the disposition and metabolic profiles of compounds administered at a low radioactive dose.

  12. An analytical method for 14C in environmental water based on a wet-oxidation process.

    Science.gov (United States)

    Huang, Yan-Jun; Guo, Gui-Yin; Wu, Lian-Sheng; Zhang, Bing; Chen, Chao-Feng; Zhang, Hai-Ying; Qin, Hong-Juan; Shang-Guan, Zhi-Hong

    2015-04-01

    An analytical method for (14)C in environmental water based on a wet-oxidation process was developed. The method can be used to determine the activity concentrations of organic and inorganic (14)C in environmental water, or total (14)C, including in drinking water, surface water, rainwater and seawater. The wet-oxidation of the organic component allows the conversion of organic carbon to an inorganic form, and the extraction of the inorganic (14)C can be achieved by acidification and nitrogen purging. Environmental water with a volume of 20 L can be used for the wet-oxidation and extraction, and a detection limit of about 0.02 Bq/g(C) can be achieved for water with carbon content above 15 mg(C)/L, obviously lower than the natural level of (14)C in the environment. The collected carbon is sufficient for measurement with a low level liquid scintillation counter (LSC) for typical samples. Extraction or recovery experiments for inorganic carbon and organic carbon from typical materials, including analytical reagents of organic benzoquinone, sucrose, glutamic acid, nicotinic acid, humic acid, ethane diol, et cetera., were conducted with excellent results based on measurement on a total organic carbon analyzer and LSC. The recovery rate for inorganic carbon ranged tween 98.7%-99.0% with a mean of 98.9(± 0.1)%, for organic carbon recovery ranged between 93.8% and 100.0% with a mean of 97.1(± 2.6)%. Verification and an uncertainty budget of the method are also presented for a representative environmental water. The method is appropriate for (14)C analysis in environmental water, and can be applied also to the analysis of liquid effluent from nuclear facilities.

  13. Carbon isotopic composition (δ(13)C and (14)C activity) of plant samples in the vicinity of the Slovene nuclear power plant.

    Science.gov (United States)

    Sturm, Martina; Vreča, Polona; Krajcar Bronić, Ines

    2012-08-01

    δ(13)C values of various plants (apples, wheat, and maize) collected in the vicinity of the Krško Nuclear Power Plant (Slovenia) during 2008 and 2009 were determined. By measuring dried samples and their carbonized counterparts we showed that no significant isotopic fractionation occurs during the carbonization phase of the sample preparation process in the laboratory. The measured δ(13)C values of the plants were used for δ(13)C correction of their measured (14)C activities.

  14. Possible influence of climate factors on the reconstruction of the cosmogenic isotope 14C production rate in the earth's atmosphere and solar activity in past epochs

    Science.gov (United States)

    Kuleshova, A. I.; Dergachev, V. A.; Kudryavtsev, I. V.; Nagovitsyn, Yu. A.; Ogurtsov, M. G.

    2015-12-01

    The paper considers the probable influence of variations of the global temperature and carbon dioxide concentration in the Earth's atmosphere on the results of reconstruction of the production rate of the cosmogenic isotope 14C in the terrestrial atmosphere for the period from the early 15th to the mid 19th century. This time interval covers the Spörer, Maunder, and Dalton minima of solar activity, as well as the Little Ice Age. It was shown that the climate changes that occurred during the Little Ice Age should be taken into account. In the Maunder and Spörer minima of solar activity, the 14C generation rate may be comparable to the values for the Dalton minimum, while exclusion of the climate effect yields extremely large values of the 14C production rate for these grand minima. In the solar activity reconstruction for past epochs, this circumstance should be taken into consideration via measurements of the 14C concentration on a long time scale.

  15. Modelling of dead carbon fraction in speleothems: a step towards reliable speleothem 14C-chronologies

    Science.gov (United States)

    Lechleitner, Franziska A.; Jamieson, Robert A.; McIntyre, Cameron; Baldini, Lisa M.; Baldini, James U. L.; Eglinton, Timothy I.

    2015-04-01

    Over the past two decades, speleothems have become one of the most versatile and promising archives for the study of past continental climate. Very precise absolute dating is often possible using the U-Th method, resulting in paleoclimate records of exceptional resolution and accuracy. However, not all speleothems are amenable to this dating method for a variety of reasons (e.g. low U concentrations, high detrital Th etc). This has lead researchers to exclude many otherwise suitable speleothems and cave sites from further investigation. 14C-dating of speleothems has so far not been applicable, due to the 'dead carbon' problem. As drip water percolates through the karst, dissolving CaCO3, a variable amount of 14C-dead carbon is added to the solution. This results in a temporally variable and site-specific reservoir effect, ultimately undermining the development of speleothem 14C -chronologies. However, a number of recent studies have shown a clear link between karst hydrology and associated proxies (e.g., Mg/Ca and δ13C) and this 'dead carbon fraction' (DCF). We take advantage of this relationship to model DCF and its changes using Mg/Ca, δ13C and 14C data from published speleothem records. Using one record for calibration purposes, we build a transfer function for the DCF in relation to δ13C and Mg/Ca, which we then apply to other 14C records. Initial model results are promising; we are able to reconstruct general long-term average DCF within uncertainties of the calculated DCF from the U-Th chronology. Large shifts in DCF related to hydrology are also often detected. In a second step, we apply the model to a speleothem from southern Poland, which so far could not be dated, due to very low U-concentrations. To construct a 14C chronology, the stalagmite was sampled at 5 mm intervals. CaCO3 powders were graphitized and measured by Accelerator Mass Spectrometry (MICADAS) at ETH Zurich. Additional high-resolution (0.1 mm/sample) 14C measurements were performed on

  16. Carbon and 14C distribution in tropical and subtropical agricultural soils

    Science.gov (United States)

    Prastowo, Erwin; Grootes, Pieter; Nadeau, Marie

    2016-04-01

    Paddy soil management affects, through the alternating anoxic and oxic conditions it creates, the transport and stabilisation of soil organic matter (SOM). Irrigation water may percolate more organic materials - dissolved (DOM) and colloidal - into the subsoil during anoxic conditions. Yet a developed ploughpan tends to prevent C from going deeper in the subsoil and partly decouple C distribution in top and sub soil. We investigate the influence of different soil type and environment. We observed the C and 14C distribution in paddy and non-paddy soil profiles in three different soil types from four different climatic regions of tropical Indonesia, and subtropical China. Locations were Sukabumi (Andosol, ca. 850 m a.s.l), Bogor (clayey Alisol, ca. 240 m a.s.l), and Ngawi (Vertisol, ca. 70 m a.s.l) in Jawa, Indonesia, and Cixi (Alisol(sandy), ca. 4 - 6 m a.s.l) in Zhejiang Province, China. We compared rice paddies with selected neighbouring non-paddy fields and employed AMS 14C as a tool to study C dynamics from bulk, alkali soluble-humic, and insoluble humin samples, and macrofossils (plant remains, charcoal). Our data suggest that vegetation type determines the quantity and quality of biomass introduced as litter and root material in top and subsoil, and thus contributes to the soil C content and profile, which fits the 14C signal distribution, as well as 13C in Ngawi with C4 sugar cane as upland crop. 14C concentrations for the mobile humic acid fraction were generally higher than for bulk samples from the same depth, except when recent plant and root debris led to high 14C levels in near-surface samples. The difference in sampling, - averaged layer for bulk sample and 1-cm layer thickness for point sample - shows gradients in C and 14C across the layers, which could be a reason for discrepancies between the two. High 14C concentrations - in Andosol Sukabumi up to 111 pMC - exceed the atmospheric 14CO2concentration in the sampling year in 2012 (˜ 103 pMC) and

  17. Synthesis of 14C-labeled perfluorooctanoic and perfluorodecanoic acids; Purification of perfluorodecanoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Reich, I.L.; Reich, H.J.; Menahan, L.A.; Peterson, R.E.

    1987-01-01

    Perfluorooctanoic and -decanoic acids are representative of a series of perfluorinated acids that have been used for a variety of industrial purposes primarily due to their surfactant properties. The toxicity of these compounds is being investigated in a number of laboratories. 14C-labeled materials would be useful in these studies but are not commercially available. Johncock prepared unlabeled PFOA in low yield by carbonation of the unstable perfluoroheptyllithium at -90 degrees Centigrade. We anticipated several problems in applying this procedure to the synthesis of the 14C-labeled material. Johncock's procedure was run on a fairly large scale (10 mmol) with excess CO2.

  18. A rapid phospholipase A2 bioassay using 14C-oleate-labelled E. coli bacterias.

    Science.gov (United States)

    Meyer, T; von Wichert, P; Weins, D

    1989-02-01

    Two methods of phospholipase A2 determination using 14C-labelled E. coli bacterias as substrate were compared. One method works with a filter membrane for separation of cleaved 14C-oleate from remaining phospholipids, the other uses the well-known thin-layer chromatography for lipid analysis. Some features of human serum phospholipase A2 regarding pH and Ca2+ dependency were investigated. Possible sources of errors were discussed. It was shown that either method can differentiate between normal and pathologically elevated phospholipase A2 levels, but that the filter method is superior in terms of sensitivity and workload.

  19. Distribution of /sup 14/C-labelled ochratoxin A in pregnant mice

    Energy Technology Data Exchange (ETDEWEB)

    Appelgren, L.E.; Arora, R.G.

    1983-10-01

    Autoradiography was used to study the distribution of /sup 14/C-labelled ochratoxin A for up to 4 hr after its iv administration to mice at various stages of pregnancy. The highest /sup 14/C concentration was consistently found in the bile throughout the experimental period. The concentration of radioactivity in the tissues was found, in decreasing order, in the liver, kidney, blood, salivary glands, large vessels, brown fat, myocardium, uterus and lymphatic tissues. The toxin was shown to cross the placental barrier on day 9 of pregnancy, at which time it is most effective in producing fetal malformations.

  20. {sup 14}C dating of the Niya site in the Tarim Basin

    Energy Technology Data Exchange (ETDEWEB)

    Yonenobu, H. E-mail: yn@dendro.naruto-u.ac.jp; Itoh, T

    2000-10-01

    The {sup 14}C ages were determined for wood samples collected from the Niya site in the Tarim Basin, China. The calendar {sup 14}C ages are the oldest in the northern part (800-100 cal BC) and the youngest (140-620 cal AD) in the southern part. The results suggest that ancient Niya had moved southward during the period of ca. 2300-1600 BP. The ages in the middle and the southern parts are consistent with the previous studies of old documents.

  1. 14C dating of the Niya site in the Tarim Basin

    Science.gov (United States)

    Yonenobu, H.; Itoh, T.

    2000-10-01

    The 14C ages were determined for wood samples collected from the Niya site in the Tarim Basin, China. The calendar 14C ages are the oldest in the northern part (800-100 cal BC) and the youngest (140-620 cal AD) in the southern part. The results suggest that ancient Niya had moved southward during the period of ca. 2300-1600 BP. The ages in the middle and the southern parts are consistent with the previous studies of old documents.

  2. Delta III—an evolutionary delta growth

    Science.gov (United States)

    Arvesen, R. J.; Simpson, J. S.

    1996-03-01

    In order to remain competitive in the future and expand the McDonnell Douglas Aerospace market share, MDA has developed an expendable launch system strategy that devices cost-effective launch systems from the Delta II with a growth vehicle configuration called Delta III. The Delta III evolves from the Delta II launch system through development of a larger payload fairing (4-meter diameter), new cryogenically propelled upper stage, new first stage fuel tank, and larger strap-on solid rocket motors. We are developing the Delta III using Integrated Product Development Teams that capitalize on the experience base that has led us to a world record breaking mission success of 49 consecutive Delta II missions. The Delta III first-launch capability is currently planned for the spring of 1998 in support of our first spacecraft customer, Hughes Space and Communications International.

  3. delta(13)C and delta(2)H isotope ratios in amphetamine synthesized from benzaldehyde and nitroethane.

    Science.gov (United States)

    Collins, Michael; Salouros, Helen; Cawley, Adam T; Robertson, James; Heagney, Aaron C; Arenas-Queralt, Andrea

    2010-06-15

    Previous work in these laboratories and by Butzenlechner et al. and Culp et al. has demonstrated that the delta(2)H isotope value of industrial benzaldehyde produced by the catalytic oxidation of toluene is profoundly positive, usually in the range +300 per thousand to +500 per thousand. Synthetic routes leading to amphetamine, methylamphetamine or their precursors and commencing with such benzaldehyde may be expected to exhibit unusually positive delta(2)H values. Results are presented for delta(13)C and delta(2)H isotope values of 1-phenyl-2-nitropropene synthesized from an industrial source of benzaldehyde, having a positive delta(2)H isotope value, by a Knoevenagel condensation with nitroethane. Results are also presented for delta(13)C and delta(2)H isotope values for amphetamine prepared from the resulting 1-phenyl-2-nitropropene. The values obtained were compared with delta(13)C and delta(2)H isotope values obtained for an amphetamine sample prepared using a synthetic route that did not involve benzaldehyde. Finally, results are presented for samples of benzaldehyde, 1-phenyl-2-nitropropene and amphetamine that had been seized at a clandestine amphetamine laboratory.

  4. Distribution of root exudates and mucilage in the rhizosphere: combining 14C imaging with neutron radiography

    Science.gov (United States)

    Holz, Maire; Carminati, Andrea; Kuzyakov, Yakov

    2015-04-01

    Water and nutrients will be the major factors limiting food production in future. Plant roots employ various mechanisms to increase the access to limited soil resources. Low molecular weight organic substances released by roots into the rhizosphere increase nutrient availability by interactions with microorganisms, while mucilage improves water availability under low moisture conditions. Though composition and quality of these substances have intensively been investigated, studies on the spatial distribution and quantification of exudates in soil are scarce. Our aim was to quantify and visualize root exudates and mucilage distribution around growing roots using neutron radiography and 14C imaging depending on drought stress. Plants were grown in rhizotrons well suited for neutron radiography and 14C imaging. Plants were exposed to various soil water contents experiencing different levels of drought stress. The water content in the rhizosphere was imaged during several drying/wetting cycles by neutron radiography. The radiographs taken a few hours after irrigation showed a wet region around the root tips showing the allocation and distribution of mucilage. The increased water content in the rhizosphere of the young root segments was related to mucilage concentrations by parameterization described in Kroener et al. (2014). In parallel 14C imaging of root after 14CO2 labeling of shoots (Pausch and Kuzyakov 2011) showed distribution of rhizodeposits including mucilage. Three days after setting the water content, plants were labeled in 14CO2 atmosphere. Two days later 14C distribution in soil was imaged by placing a phosphor-imaging plate on the rhizobox. To quantify rhizodeposition, 14C activity on the image was related to the absolute 14C activity in the soil and root after destructive sampling. By comparing the amounts of mucilage (neutron radiography) with the amount of total root derived C (14C imaging), we were able to differentiate between mucilage and root

  5. Radiocarbon analysis of the EPICA Dome C ice core: no in situ {sup 14}C from the firn observed

    Energy Technology Data Exchange (ETDEWEB)

    Jong, A.F.M. de; Alderliesten, C.; Borg, K. van der E-mail: k.vanderborg@phys.uu.nl; Veen, C. van der; Wal, R.S.W. van de

    2004-08-01

    CO{sub 2} and CO obtained by dry-extraction from ice samples of the EPICA Dome C core were {sup 14}C analysed by AMS. For some of the ice samples there is no evidence for in situ {sup 14}C, indicating the firn did not retain {sup 14}C. The {sup 14}C ages of these samples are too old in comparison with a calibrated ice-flow model, and the concentrations of {sup 14}CO are near zero. For other ice samples, however, in situ {sup 14}C is clearly present, and is likely from post-coring exposure at the Dome C surface. These samples show too young {sup 14}C ages, and distinct concentrations of {sup 14}CO. The accuracy of ages obtained from {sup 14}C analysis of ice samples is discussed.

  6. Validation of low activity {sup 14}C-urea breath test in diagnosis of ``Helicobacter pylori``in humans

    Energy Technology Data Exchange (ETDEWEB)

    Bielanski, W.; Konturek, S.J.; Dobrzanka, M.J.; Plonka, M.; Sito, E.; Stachura, J. [Uniwersytet Jagiellonski, Cracow (Poland); Hoffman, S.R.; Marshall, B.J. [Tri-Med Specialtis, Charlottenville, VA (United States)

    1996-12-31

    Etiologic role for ``Helicobacter pylori`` (HP) seems to be well established in gastric pathology. The high urease activity of HP can be used to detect this bacterium by non-invasive urea breath tests (UBT). We validated the low activity version of the test in which 37 kBq {sup 14}C-urea is given orally in capsule. With the cut off value {>=} 1.66 Bq (100 DPM) as positive, UBT results correlated highly significant with combined results for invasive methods, i.e. CLO-test + Histology score. The reproducibility of the test was 100%. The results obtained for the breath test performed locally were almost identical with that read at remote laboratory. The data found for fasting and fed states of subjects agreed in 87%. When {sup 14}C-urea was confined in the mouth of both HP positive and HP negative patients UBT showed the presence of urease activity in the mouth cavity. (author). 21 refs, 2 figs, 1 tab.

  7. CO2 concentrations and delta13C (CO2) values in monthly sets of air samples from downtown Parma and the Parma and Taro river valleys, Emilia-Romagna, Italy.

    Science.gov (United States)

    Longinelli, Antonio; Selmo, Enricomaria

    2006-09-01

    Monthly sets of discrete air samples were collected from September 2004 to June 2005 in the town of Parma, along North-South and East-West runs (8 plus 8 samples), using four-litre Pyrex flasks. The CO2 concentrations and delta13C values were determined on these samples with the aim of evaluating quantitatively the contribution of domestic heating to the winter atmospheric CO2 pollution in downtown Parma by comparing autumn and spring atmospheric values with winter values. After separation of CO2 from the other air gases in the laboratory, the CO2 concentrations were calculated from the intensity of the 12C16O2+ ion beam in the mass spectrometer, after calibration with artificial air samples whose CO2 concentration was very carefully determined by the Monte Cimone Observatory (Sestola, Modena, Italy). The reproducibility of these measurements was of approximately +/-0.4 % and, consequently, the most probable error is not higher than+/-2-3 ppmv and does not affect the magnitude of the gradients between different samples. The standard deviation of delta13C measurements ranges from+/-0.02 to +/-0.04 per thousand (1sigma). The results suggest that the contribution of domestic heating to atmospheric CO2 pollution is almost negligible in the case of ground level atmosphere, where the main CO2 pollution is essentially related to the heavy car traffic. This is probably because of the fact that the gases from the domestic heating systems are discharged tens of metres above ground level at a relatively high temperature so that they rise quickly to the upper atmospheric layers and are then displaced by air masses dynamics. Monthly sets of discrete air samples were also collected from October 2004 to June 2005 along North-South runs from the town of Parma to the Apennine ridge following the Parma and the Taro river valleys (8 samples and 7 samples per set, respectively) and measured using the same technique. The aim of this study was the comparison between the town samples

  8. Pharmacokinetics of (14) C-ortho-phenylphenol following intravenous administration in pigs.

    Science.gov (United States)

    Nixon, Emma; Brooks, James D; Routh, Patricia A; Chittenden, Jason T; Baynes, Ronald E

    2017-04-01

    Workers in the USA are exposed to industrial formulations, which may be toxic. These formulations often contain preservatives or biocides such as ortho-phenylphenol (OPP). There are limited data describing OPP following intravenous administration to assess truly the clearance of this chemical in humans and other species. In vivo experiments were conducted in pigs to determine related pharmacokinetic parameters. (14) C-OPP was administered as an intravenous bolus dose. Blood, feces, urine and tissue samples were collected for analysis by liquid scintillation. Data were analyzed using non-compartmental and compartmental pharmacokinetic model approaches. These data fitted a three-compartment model and showed that the half-life of (14) C-OPP following the intravenous bolus in pigs was 46.26 ± 10.01 h. The kidneys play a crucial role in clearance of (14) C-OPP with a large percentage of the dose being found in the urine (70.3 ± 6.9% dose). Comparisons with other species suggest that (14) C-OPP clearance in pigs (2.48 ml h(-1)  kg(-1) ) is less than that in humans (18.87 ml h(-1)  kg(-1) ) and rats (35.51 ml h(-1)  kg(-1) ). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Pharmacokinetic analysis of 14C-ursodiol in newborn infants using accelerator mass spectrometry.

    Science.gov (United States)

    Gordi, Toufigh; Baillie, Rebecca; Vuong, Le T; Abidi, Saira; Dueker, Stephen; Vasquez, Herbert; Pegis, Priscilla; Hopper, Andrew O; Power, Gordon G; Blood, Arlin B

    2014-09-01

    Pharmacokinetic studies in the neonatal population are often limited by the small volume of blood that can be collected. The high sensitivity of (14) C-accelerator mass spectrometry (AMS) enables pharmacokinetic studies to be conducted with greatly reduced sample volumes. We demonstrated the utility of AMS in infants by studying the plasma pharmacokinetic behavior of nanogram doses of (14) C-ursodiol administered as a non-perturbing microdose or as a microtracer with therapeutic doses of non-labeled ursodiol in infants. Five non-cholestatic infants were administered 3 consecutive oral microdoses of (14) C-ursodiol: 8 ng (1.0 nCi), 26 ng (3.3 nCi), and 80 ng (10 nCi) 48 hours apart. Three additional infants with cholestasis were administered a single 80 ng (10.0 nCi) oral dose of (14) C-ursodiol together with a therapeutic dose of 40 mg/kg of non-labeled ursodiol. A pharmacokinetic model describing ursodiol concentrations was developed using nonlinear mixed-effects modeling. The pharmacokinetics of ursodiol in this pilot study were best described by a two-compartment model with first-order elimination. This study demonstrates the feasibility and utility of microdose and microtrace methodology in pediatric research.

  10. Mass Balance Model, A study of contamination effects in AMS 14C sample analysis

    NARCIS (Netherlands)

    Prokopiou, Markella

    2010-01-01

    In this training thesis a background correction analysis, also known as mass balance model, was implemented to study the contamination effects in AMS 14C sample processing. A variety of backgrounds and standards with sizes ranging from 50 μg C to 1500 μg

  11. Disposition of 14C-erythritol in germfree and conventional rats

    NARCIS (Netherlands)

    Ommen, B. van; Bie, B. de; Bar, A.

    1996-01-01

    The metabolism and disposition of U-14C-erythritol was examined in four groups of three male and three female, nonfasted rats each. The rats of groups A and D were germfree; the rats of groups B and C were kept under conventional conditions. The rats of group B received an erythritol-supplemented

  12. 3$\\alpha$-cluster structure and monopole transition in $^{12}$C and $^{14}$C

    CERN Document Server

    Yoshida, Yuta

    2016-01-01

    3$\\alpha$-cluster structures and monopole transitions of $0^+$ states in $^{12}$C and $^{14}$C were investigated with $3\\alpha$- and $^{10}$Be+$\\alpha$-cluster models. A gas-like $3\\alpha$ state and a bending-chain $3\\alpha$ state were obtained in the $0^+_2$ and $0^+_3$ states of $^{12}$C, respectively. In $^{14}$C, a linear-chain 3$\\alpha$ structure is found in the $0^+_4$ state near the $^{10}$Be+$\\alpha$ threshold, but a cluster gas-like state does not appear because valence neutrons attract $\\alpha$ clusters and suppress spatial development of 3$\\alpha$ clustering. It was found that the linear-chain state in $^{14}$C is stabilized against the bending and $\\alpha$ escaping modes by valence neutrons. The monopole transition strengths in $^{12}$C are enhanced by $3\\alpha$-cluster developing, whereas, those in $^{14}$C are not enhanced so much because of the tight binding of $\\alpha$ clusters by valence neutrons.

  13. AMS-14C analysis of modern teeth: A comparison between two sample preparation techniques

    Science.gov (United States)

    Solis, C.; Solis-Meza, E.; Morales, M. E.; Rodriguez-Ceja, M.; Martínez-Carrillo, M. A.; Garcia-Calderon, D.; Huerta, A.; Chávez, E.

    2017-09-01

    AMS-14C analysis of modern teeth has become important for forensic studies. 14C content in human teeth reflects the 14C atmospheric concentration during its formation and allows the calculation of the actual year of birth. Through AMS, it is possible to measure the 14C concentrations in a tissue with high precision. However, there is a debate about which should be the best fraction for teeth carbon dating: collagen or enamel. This work focuses on the results obtained from enamel and collagen extracted from Mexican people in order to compare them. Collagen from dental pieces donated from people older than 60-years-old have been included to understand the turnover process and usefulness of collagen to determine the date of birth. Our results indicate that when a single dental piece is available, enamel method allows the determination of the tooth formation date. Dating collagen of the same tooth helps to discriminate if the formation date belongs to the left or the right side of the peak bomb, but also corroborates, the ages obtained through enamel analysis.

  14. Comparison of 14C and luminescence chronologies at puritjarra rock shelter, central Australia

    Science.gov (United States)

    Smith, M. A.; Prescott, J. R.; Head, M. J.

    At Puritjarra rock shelter a long comparative sequence permits detailed comparisons of luminescence and radiocarbon chronologies over 35,000 years. Both techniques produce self-consistent chronologies for the Puritjarra deposit, but observed discrepancies between luminescence dates on unburnt sediments and 14C, assays on charcoal are greater than reported elsewhere. TL ages are generally older than 14C ages but dates converge at depths below 70 cm, dating first significant human occupation of the rock shelter ˜35,000 years ago. The discrepancies are not removed by calibrating 14C dates or adjusting TL ages for lower water content of sediments. The 14C chronology is broadly supported by sedimentary or palaeobotanical evidence, stone artefact typology and other archaeological data. Radiocarbon dates on intact hearths agree with those on detrital charcoal. TL ages were arrived at using both 'total bleach' and 'selective bleach' methods and the latter agree with optical ages for the same samples. Incomplete bleaching of sediments during deposition can be ruled out. Incorporation of old material into the luminescence samples via in-situ disintegration of local sandstone remains a possibility and will be an important issue to resolve as luminescence techniques are increasingly deployed to date archaeological deposits in rock shelters.

  15. Successful Use of [14C]Paracetamol Microdosing to Elucidate Developmental Changes in Drug Metabolism

    NARCIS (Netherlands)

    M.G. Mooij (Miriam); E. van Duijn (Esther); C.A.J. Knibbe (Catherijne); K. Allegaert (Karel); J. Windhorst (Judith); J.M. van Rosmalen (Joost); N.H. Hendrikse (N. Harry); D. Tibboel (Dick); W.H.J. Vaes (Wouter H. J.); S.N. de Wildt (Saskia)

    2017-01-01

    textabstractBackground: We previously showed the practical and ethical feasibility of using [14C]-microdosing for pharmacokinetic studies in children. We now aimed to show that this approach can be used to elucidate developmental changes in drug metabolism, more specifically, glucuronidation and sul

  16. Holocene Intermediate Water Variability in the Northeast Pacific: A Santa Barbara Basin 14C Record

    Science.gov (United States)

    Friddell, J. E.; Thunell, B.; Guilderson, T.; Roark, B.

    2009-05-01

    Pairs of benthic and planktonic foraminiferal 14C dates from the Santa Barbara Basin, offshore southern California, are used to assess millennial-scale hydrographic changes in the northeast Pacific during the Holocene. Current models of North Pacific Intermediate Water formation during the last glacial and the Holocene vary widely in their predicted relationships between thermal conditions in the north Pacific, 14C age and oxygen content of the Santa Barbara Basin's sub-sill bottom waters, and productivity in the basin's surface waters. Using benthic-planktonic 14C age differences as a proxy for North Pacific Intermediate Water influence on the basin's bottom waters and biogenic silica and sedimentary bioturbation as records of past productivity and bottom-water oxygenation, we test our data against these various models. It appears that the different models can be reconciled by invoking bifurcation of eastward-moving intermediate water along the North American coast: Changes in the benthic-planktonic 14C age difference and other proxies in Santa Barbara Basin can be explained by movement of the bifurcation point to the north or south during warm and cool intervals of the Holocene. Inferred behavior of water at intermediate depths on the northeast Pacific margin is compared with surface conditions and with records of deep circulation from the North Atlantic, with the Santa Barbara Basin records supporting surface and intermediate connection between the two ocean basins at millennial time scales during the Holocene.

  17. Pharmacokinetics and excretion of 14C-omacetaxine in patients with advanced solid tumors

    NARCIS (Netherlands)

    Nijenhuis, Cynthia M.; Hellriegel, Edward; Beijnen, Jos H.; Hershock, Diane; Huitema, Alwin D R; Lucas, Luc; Mergui-Roelvink, Marja; Munteanu, Mihaela; Rabinovich-Guilatt, Laura; Robertson, Philmore; Rosing, Hilde; Spiegelstein, Ofer; Schellens, Jan H M

    2016-01-01

    Background Omacetaxine mepesuccinate is indicated in adults with chronic myeloid leukemia resistant and/or intolerant to ≥ 2 tyrosine kinase inhibitor treatments. This phase I study assessed the disposition, elimination, and safety of 14C-omacetaxine in patients with solid tumors. Methods The study

  18. Nuclear Structure Effects in the Exotic Decay of $^{225}$Ac via $^{14}$C Emission

    CERN Multimedia

    2002-01-01

    % IS323 \\\\ \\\\ We propose to build at Isolde a high intensity $^{225}$Ac source by $\\beta$-decay of $^{225}$(Ra+Fr) beam, to be used at the superconducting spectrometer SOLENO of IPN-Orsay in order to study a possible fine structure in the spectrum of $^{14}$C ions spontaneously emitted by $^{225}$Ac.

  19. Fate of organochlorine 14C-dicofol in a lab-scale wastewater treatment

    Science.gov (United States)

    Oliveira, Jaime L. M.; Langenbach, Tomaz; Dezotti, Márcia

    2008-01-01

    The fate of organochlorine 14C-dicofol in activated sludge process was investigated. Results showed that the major part of radioactivity remained adsorbed on biological sludge. Consequently, its final disposal deserves special attention. The small amounts of dicofol, biotransformed or not, which remained in the treated effluent could contaminate receiving bodies. PMID:24031222

  20. 14C as a tracer of labile organic matter in Antarctic benthic food webs

    Science.gov (United States)

    Purinton, Brett L.; DeMaster, David J.; Thomas, Carrie J.; Smith, Craig R.

    2008-11-01

    14C measurements were made on surface plankton, particle-trap material, surface sediment, benthic invertebrate gut contents, and body tissue samples to assess the effectiveness of this radioisotope as a tracer of labile organic carbon in Antarctic benthic food webs. Samples were collected on five cruises to the West Antarctic Peninsula (WAP) shelf between November 1999 and March 2001 as part of the Food for Benthos on the ANtarctic Continental-Shelf (FOODBANCS) Project. The 14C contents of the body tissues from a variety of deposit feeders (-126±13 per mil) were substantially enriched relative to the surface sediment (-234±13 per mil) and statistically similar to the organic matter collected in plankton tows (-135±10 per mil), indicating that recently produced marine plankton are the primary source of nutrition for these deposit feeders on the West Antarctic shelf. Selective ingestion was the primary feeding strategy used by echiuran worms and certain holothurians (i.e. Peniagone vignoni) for incorporating labile organic carbon into their tissues as demonstrated by the large differences (105±13 per mil) between surface sediment and gut content 14C activities. In contrast, digestive and/or assimilatory selection was the predominant strategy used by an irregular urchin ( Amphipneustes lorioli) and several other holothurians ( Protelpidia murrayi, Bathyplotes fuscivinculum and the head-down conveyor belt feeder, Molpadia musculus), as demonstrated by large differences (42±7 per mil) between the 14C activities of their foregut or whole-gut organic contents and their body tissues. Despite large fluctuations in carbon export from the euphotic zone, benthic feeding strategies remained essentially constant over the 15-month sampling period. No seasonal variation was evident in either the 14C abundance of the deposit-feeder body tissues, or in the 14C abundance of their gut contents. The mean 14C abundance in the body tissues of the two sub-surface deposit feeders ( A

  1. The Delta 2 launcher

    Science.gov (United States)

    Ousley, Gilbert W., Sr.

    1991-12-01

    The utilization of the Delta 2 as the vehicle for launching Aristoteles into its near Sun synchronous orbit is addressed. Delta is NASA's most reliable launch vehicle and is well suited for placing the present Aristoteles spacecraft into a 400 m circular orbit. A summary of some of the Delta 2 flight parameters is presented. Diagrams of a typical Delta 2 two stage separation are included along with statistics on delta reliability and launch plans.

  2. Characteristics of 14C and 13C of carbonate aerosols in dust storm events in China

    Science.gov (United States)

    Chen, Bing; Jie, Dongmei; Shi, Meinan; Gao, Pan; Shen, Zhenxing; Uchida, Masao; Zhou, Liping; Liu, Kexin; Hu, Ke; Kitagawa, Hiroyuki

    2015-10-01

    In contrast with its decrease in western China deserts, the dust storm event in eastern China, Korea, and Japan shows an increase in frequency. Although the drylands in northeastern China have been recognized as an important dust source, the relative contributions of dust transport from the drylands and deserts are inconclusive, thus the quantification of dust storm sources in downwind area remains a challenge. We measured the 14C and 13C contents in carbonates of dust samples from six sites in China, which were collected for the duration of dust storm events in drylands, deserts, and urban areas. The δ13C of the dryland dust samples considerably varied in a range of - 9.7 to - 5.0‰, which partly overlapped the desert dust carbonate δ13C ranges. The 14C content of the dryland dust carbonates showed a narrow range of 60.9 ± 4.0 (as an average and 1 SD of five samples) percent modern carbon (pMC), indicating the enrichment of modern carbonate. Dust samples in desert regions contained relatively aged carbonates with the depleting 14C showing of 28.8 ± 3.3 pMC. After the long-range transport of the western China desert dust plume, the carbonates collected at the southern China remained the depletion of 14C (33.5 ± 5.3 pMC) as in the desert regions. On the other hand, the samples of dust storm events at the urban areas of eastern China showed an enrichment of 14C contents (46.2 ± 5.0 pMC, n = 7), which might be explained by the stronger contribution of modern-carbonate-rich dryland dust.

  3. Reconciling Change in Oi-Horizon 14C With Mass Loss for an Oak Forest

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P J; Swanston, C W; Garten, Jr., C T; Todd, D E; Trumbore, S E

    2005-06-27

    First-year litter decomposition was estimated for an upland-oak forest ecosystem using enrichment or dilution of the {sup 14}C-signature of the Oi-horizon. These isotopically-based mass-loss estimates were contrasted with measured mass-loss rates from past litterbag studies. Mass-loss derived from changes in the {sup 14}C-signature of the Oi-horizon suggested mean mass loss over 9 months of 45% which was higher than the corresponding 9-month rate extrapolated from litterbag studies ({approx}35%). Greater mass loss was expected from the isotopic approach because litterbags are known to limit mass loss processes driven by soil macrofauna (e.g., fragmentation and comminution). Although the {sup 14}C-isotope approach offers the advantage of being a non-invasive method, it exhibited high variability that undermined its utility as an alternative to routine litterbag mass loss methods. However, the {sup 14}C approach measures the residence time of C in the leaf litter, rather than the time it takes for leaves to disappear; hence radiocarbon measures are subject to C immobilization and recycling in the microbial pool, and do not necessarily reflect results from litterbag mass loss. The commonly applied two-compartment isotopic mixing model was appropriate for estimating decomposition from isotopic enrichment of near-background soils, but it produced divergent results for isotopic dilution of a multi-layered system with litter cohorts having independent {sup 14}C-signatures. This discrepancy suggests that cohort-based models are needed to adequately capture the complex processes involved in carbon transport associated with litter mass-loss. Such models will be crucial for predicting intra- and interannual differences in organic horizon decomposition driven by scenarios of climatic change.

  4. Pharmacokinetics and excretion of (14)C-omacetaxine in patients with advanced solid tumors.

    Science.gov (United States)

    Nijenhuis, Cynthia M; Hellriegel, Edward; Beijnen, Jos H; Hershock, Diane; Huitema, Alwin D R; Lucas, Luc; Mergui-Roelvink, Marja; Munteanu, Mihaela; Rabinovich-Guilatt, Laura; Robertson, Philmore; Rosing, Hilde; Spiegelstein, Ofer; Schellens, Jan H M

    2016-10-01

    Background Omacetaxine mepesuccinate is indicated in adults with chronic myeloid leukemia resistant and/or intolerant to ≥ 2 tyrosine kinase inhibitor treatments. This phase I study assessed the disposition, elimination, and safety of (14)C-omacetaxine in patients with solid tumors. Methods The study comprised a 7-days pharmacokinetic assessment followed by a treatment period of ≤ six 28-days cycles. A single subcutaneous dose of 1.25 mg/m(2) (14)C-omacetaxine was administered to six patients. Blood, urine, and feces were collected through 168 h or until radioactivity excreted within 24 h was <1 % of the dose. Total radioactivity (TRA) was measured in all matrices and concentrations of omacetaxine, 4'-desmethylhomoharringtonine (4'-DMHHT), and cephalotaxine were measured in plasma and urine. For each treatment cycle, patients received 1.25 mg/m(2) omacetaxine twice daily for 7 days. Results Mean TRA recovered was approximately 81 % of the dose, with approximately half of the radioactivity recovered in feces and half in urine. Approximately 20 % of the dose was excreted unchanged in urine; cephalotaxine (0.4 % of dose) and 4' DMHHT (9 %) were also present. Plasma concentrations of TRA were higher than the sum of omacetaxine and known metabolites, suggesting the presence of other (14)C-omacetaxine-derived compounds. Fatigue and anemia were common, consistent with the known toxicity profile of omacetaxine. Conclusion Renal and hepatic processes contribute to the elimination of (14)C-omacetaxine-derived radioactivity in cancer patients. In addition to omacetaxine and its known metabolites, other (14)C-omacetaxine-derived materials appear to be present in plasma and urine. Omacetaxine was adequately tolerated, with no new safety signals.

  5. Mineralization and Transfer Processes of {sup 14}C-labeled Pesticides in Outdoor Lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, Sabine; Doerfler, Ulrike, E-mail: doerfler@gsf.de; Ruth, Bernhard; Loos, Christine [GSF - National Research Center for Environment and Health, Institute of Soil Ecology (Germany); Wagner, Tobias [GSF - National Research Center for Environment and Health, Institute of Biochemical Plant Pathology (Germany); Karl, Heidrun; Munch, Jean Charles; Schroll, Reiner [GSF - National Research Center for Environment and Health, Institute of Soil Ecology (Germany)

    2008-04-15

    A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of {sup 14}C-labeled substances in soil-plant-atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between {sup 14}C-emissions from soil surfaces and {sup 14}C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate - using the two-chamber-lysimeter-test-system - are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil-plant-systems. Mineralization of {sup 14}C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide {sup 14}C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules.

  6. Use of an intravenous microdose of 14C-labeled drug and accelerator mass spectrometry to measure absolute oral bioavailability in dogs; cross-comparison of assay methods by accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Miyaji, Yoshihiro; Ishizuka, Tomoko; Kawai, Kenji; Hamabe, Yoshimi; Miyaoka, Teiji; Oh-hara, Toshinari; Ikeda, Toshihiko; Kurihara, Atsushi

    2009-01-01

    A technique utilizing simultaneous intravenous microdosing of (14)C-labeled drug with oral dosing of non-labeled drug for measurement of absolute bioavailability was evaluated using R-142086 in male dogs. Plasma concentrations of R-142086 were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and those of (14)C-R-142086 were measured by accelerator mass spectrometry (AMS). The absence of metabolites in the plasma and urine was confirmed by a single radioactive peak of the parent compound in the chromatogram after intravenous microdosing of (14)C-R-142086 (1.5 microg/kg). Although plasma concentrations of R-142086 determined by LC-MS/MS were approximately 20% higher than those of (14)C-R-142086 as determined by AMS, there was excellent correlation (r=0.994) between both concentrations after intravenous dosing of (14)C-R-142086 (0.3 mg/kg). The oral bioavailability of R-142086 at 1 mg/kg obtained by simultaneous intravenous microdosing of (14)C-R-142086 was 16.1%, this being slightly higher than the value (12.5%) obtained by separate intravenous dosing of R-142086 (0.3 mg/kg). In conclusion, on utilizing simultaneous intravenous microdosing of (14)C-labeled drug in conjunction with AMS analysis, absolute bioavailability could be approximately measured in dogs, but without total accuracy. Bioavailability in humans may possibly be approximately measured at an earlier stage and at a lower cost.

  7. Spatial variations in geochemical characteristics of the modern Mackenzie Delta sedimentary system

    Science.gov (United States)

    Vonk, Jorien E.; Giosan, Liviu; Blusztajn, Jerzy; Montlucon, Daniel; Graf Pannatier, Elisabeth; McIntyre, Cameron; Wacker, Lukas; Macdonald, Robie W.; Yunker, Mark B.; Eglinton, Timothy I.

    2015-12-01

    The Mackenzie River in Canada is by far the largest riverine source of sediment and organic carbon (OC) to the Arctic Ocean. Therefore the transport, degradation and burial of OC along the land-to-ocean continuum for this riverine system is important to study both regionally and as a dominant representative of Arctic rivers. Here, we apply sedimentological (grain size, mineral surface area), and organic and inorganic geochemical techniques (%OC, δ13C-OC and Δ14C-OC, 143Nd/144Nd, δ2H and δ18O, major and trace elements) on particulate, bank, channel and lake surface sediments from the Mackenzie Delta, as well as on surface sediments from the Mackenzie shelf in the Beaufort Sea. Our data show a hydrodynamic sorting effect resulting in the accumulation of finer-grained sediments in lake and shelf deposits. A general decrease in organic carbon (OC) to mineral surface area ratios from river-to-sea furthermore suggests a loss of mineral-bound terrestrial OC during transport through the delta and deposition on the shelf. The net isotopic value of the terrestrial OC that is lost en route, derived from relationships between δ13C, OC and surface area, is -28.5‰ for δ13C and -417‰ for Δ14C. We calculated that OC burial efficiencies are around 55%, which are higher (∼20%) than other large river systems such as the Amazon. Old sedimentary OC ages, up to 12 14C-ky, suggest the delivery of both a petrogenic OC source (with an estimated contribution of 19 ± 9%) as well as a pre-aged terrestrial OC source. We calculated the 14C-age of this pre-aged, biogenic, component to be about 6100 yrs, or -501‰, which illustrates that terrestrial OC in the watershed can reside for millennia in soils before being released into the river. Surface sediments in lakes across the delta (n = 20) showed large variability in %OC (0.92-5.7%) and δ13C (-30.7‰ to -23.5‰). High-closure lakes, flooding only at exceptionally high water levels, hold high sedimentary OC contents (>2.5%) and

  8. Method for evaluating the potential of {sup 14}C labeled plant polyphenols to cross the blood-brain barrier using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Janle, Elsa M., E-mail: janle@purdue.ed [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States); Lila, Mary Ann [University of Illinois, Department of Natural Resources and Environmental Sciences Urbana IL (United States); Grannan, Michael; Wood, Lauren; Higgins, Aine [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States); Yousef, Gad G.; Rogers, Randy B. [University of Illinois, Department of Natural Resources and Environmental Sciences Urbana IL (United States); Kim, Helen [University of Alabama at Birmingham, Department of Pharmacology, Birmingham AB (United States); Jackson, George S. [Purdue University, Department of Physics, West Lafayette, IN (United States); Weaver, Connie M. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-0259 (United States)

    2010-04-15

    Bioactive compounds in botanicals may be beneficial in preventing age-related neurodegenerative diseases, but for many compounds conventional methods may be inadequate to detect if these compounds cross the blood-brain barrier or to track the pharmacokinetics in the brain. By combining a number of unique technologies it has been possible to utilize the power of AMS to study the pharmacokinetics of bioactive compounds in the brain at very low concentrations. {sup 14}C labeled compounds can be biosynthesized by plant cell suspension cultures co-incubated with radioisotopically-labeled sucrose and isolated and separated into a series of bioactive fractions. To study the pharmacokinetics and tissue distribution of {sup 14}C labeled plant polyphenols, rats were implanted with jugular catheters, subcutaneous ultrafiltration probes and brain microdialysis probes. Labeled fractions were dosed orally. Interstitial fluid (ISF) and brain microdialysate samples were taken in tandem with blood samples. It was often possible to determine {sup 14}C in blood and ISF with a beta-counter. However, brain microdialysate samples {sup 14}C levels on the order of 10{sup 7} atoms/sample required AMS technology. The Brain Microdialysate{sub AUC}/Serum{sub AUC} ranged from .021- to .029, with the higher values for the glycoside fractions. By using AMS in combination with traditional methods, it is possible to study uptake by blood, distribution to ISF and determine the amount of a dose which can reach the brain and follow the pharmacokinetics in the brain.

  9. Rapid radiosynthesis of [11C] and [14C]azelaic, suberic, and sebacic acids for in vivo mechanistic studies of systemic acquired resistance in plants

    Energy Technology Data Exchange (ETDEWEB)

    Best M.; Fowler J.; Best, M.; Gifford, A.N.; Kim, S.W.; Babst, B.; Piel, M.; Roesch, F.; Fowler, J.S.

    2011-11-25

    A recent report that the aliphatic dicarboxylic acid, azelaic acid (1,9-nonanedioic acid) but not related acids, suberic acid (1,8-octanedioic acid) or sebacic (1,10-decanedioic acid) acid induces systemic acquired resistance to invading pathogens in plants stimulated the development of a rapid method for labeling these dicarboxylic acids with {sup 11}C and {sup 14}C for in vivo mechanistic studies in whole plants. {sup 11}C-labeling was performed by reaction of ammonium [{sup 11}C]cyanide with the corresponding bromonitrile precursor followed by hydrolysis with aqueous sodium hydroxide solution. Total synthesis time was 60 min. Median decay-corrected radiochemical yield for [{sup 11}C]azelaic acid was 40% relative to trapped [{sup 11}C]cyanide, and specific activity was 15 GBq/{micro}mol. Yields for [{sup 11}C]suberic and sebacic acids were similar. The {sup 14}C-labeled version of azelaic acid was prepared from potassium [{sup 14}C]cyanide in 45% overall radiochemical yield. Radiolabeling procedures were verified using {sup 13}C-labeling coupled with {sup 13}C-NMR and liquid chromatography-mass spectrometry analysis. The {sup 11}C and {sup 14}C-labeled azelaic acid and related dicarboxylic acids are expected to be of value in understanding the mode-of-action, transport, and fate of this putative signaling molecule in plants.

  10. Fat malabsorption assessed by 14C-triolein breath test in HIV-positive patients in different stages of infection: is it an early event?

    Science.gov (United States)

    Ribeiro Machado, F; Gonzaga Vaz Coelho, L; Chausson, Y; Greco, D B

    2000-06-01

    The aim of this study was to evaluate fat absorption in HIV-positive (HIV+) patients in different phases of HIV infection using a 14C-triolein breath test. We distributed 47 HIV+ patients according to the 1993 Centers for Disease Control Revised Classification: 20 in Group 2 (A1 or A2) and 27 in Group 3 (B1, B2, A3, B3, or C). Ten HIV-negative healthy subjects comprised the control group (Group 1). All individuals underwent a 14C-triolein breath test. Parasitic infection was evaluated through three stool exams, including Cryptosporidium and Isospora investigation. The median value of cumulative 6 hours' 14C excretion expressed as percentage of the 14C given as triolein was significantly higher in Group 1 (8.4%) than Group 2 (5.5%) or Group 3 (3.4%), p = 0.04 and p < 0.01, respectively. Fat malabsorption was found in 25% of Group 2 individuals, 52.6% of those without diarrhea in Group 3, and was correlated with CD4+ lymphocyte counts (p < 0.01). Fat malabsorption is a common feature in advanced stages of HIV infection, even in the absence of diarrhea and is also present in asymptomatic HIV+ patients. These findings suggest that malabsorption is an early event in HIV-infected individuals and is correlated with the degree of immunosuppression.

  11. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba.

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    Full Text Available The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC, nitrogen (TN, phosphorus (TP, elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g(-1. Sites near the island's lower slope had lower TOC average concentrations (158-333 µmol g(-1 than those closer to the channel axis (averaging 341-516 µmol g(-1; p <0.05. The TN concentrations near the lower slope attained 0.11% (80 µmol g(-1, whereas, towards the channel axis, they decreased to 0.07% (55 µmol g(-1; p<0.05. The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4 indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol gv; 0.12% to 0.16% than those near the channel axis (50.0 to 66 µmol g(-1; 0.15 to 0.21%. C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic δ13Corg and δ15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP. We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed.

  12. Sources and transport of Δ14C in CO2 within the Mexico City Basin and vicinity

    Directory of Open Access Journals (Sweden)

    H. B. Singh

    2009-07-01

    Full Text Available Radiocarbon samples taken over Mexico City and the surrounding region during the MILAGRO field campaign in March 2006 exhibited an unexpected distribution: (1 relatively few samples (23% were below the North American free tropospheric background value (57±2‰ despite the fossil fuel emissions from one of the world's most highly polluted environments; and (2 frequent enrichment well above the background value was observed. Correlate source tracer species and air transport characteristics were examined to elucidate influences on the radiocarbon distribution. Our analysis suggests that a combination of radiocarbon sources biased the "regional radiocarbon background" above the North American value thereby decreasing the apparent fossil fuel signature. Likely sources include the release of 14C-enhanced carbon from bomb 14C sequestered in plant carbon pools via the ubiquitous biomass burning in the region as well as the direct release of radiocarbon as CO2 from other "hot" sources. Plausible perturbations from local point "hot" sources include the burning of hazardous waste in cement kilns; medical waste incineration; and emissions from the Laguna Verde Nuclear Power Plant. These observations provide insight into the use of Δ14CO2 to constrain fossil fuel emissions in the megacity environment, indicating that underestimation of the fossil fuel contribution to the CO2 flux is likely wherever biomass burning coexists with urban emissions and is unaccounted for as a source of the elevated CO2 observed above local background. Our findings increase the complexity required to quantify fossil fuel-derived CO2 in source-rich environments characteristic of megacities, and have implications for the use of Δ14CO2 observations in evaluating bottom-up emission inventories and their reliability as a tool for validating national emission claims of CO2 within the framework of the Kyoto Protocol.

  13. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba.

    Science.gov (United States)

    de la Lanza Espino, Guadalupe; Soto, Luis A

    2015-01-01

    The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC), nitrogen (TN), phosphorus (TP), elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm) displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g(-1)). Sites near the island's lower slope had lower TOC average concentrations (158-333 µmol g(-1)) than those closer to the channel axis (averaging 341-516 µmol g(-1); p <0.05). The TN concentrations near the lower slope attained 0.11% (80 µmol g(-1)), whereas, towards the channel axis, they decreased to 0.07% (55 µmol g(-1); p<0.05). The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4) indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol gv; 0.12% to 0.16%) than those near the channel axis (50.0 to 66 µmol g(-1); 0.15 to 0.21%). C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic δ13Corg and δ15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP). We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed.

  14. Emission of {sup 14}C by the Almirante Alvaro Alberto Nuclear Power Plant 1 and 2 and their local effects on the environmental levels; Emissao de {sup 14}C pelas unidades 1 e 2 da Central Nuclear Almirante Alvaro Alberto (CNAAA) e seu efeito local nos niveis ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Cintia Melazo

    2006-07-01

    radiocarbon through measurements of air samples taken with 3 km from power plants, in five different wind directions. The sampling system consisted of a pump connected to a trapping column filled with 3 M NaOH solution. The trapped CO{sub 2} was, then, precipitated as BaCO{sub 3} using a BaCl{sub 2} solution. For the measurements, the single stage accelerator mass spectrometry system (SSAMS) was used. This system belongs to the Radiocarbon Laboratory located in Geology Department of Lund University, in Sweden. The third paper is the investigation of {sup 14}C content in vegetation samples. Since food chain starts with plants, these measurements are useful to estimate radiation exposure to local population. Grass samples were taken up to five km from power plants, in seven different wind directions. The SSAMS was employed for the analyses. The last paper involves the study of soils taken just close to power plants (within 1 km) and at 50 km far from them, in a reference area. Not only {sup 14}C content was determined but analyzes of {delta}{sup 13}C, total C and {sup 137}Cs were also made. SSAMS was used for the {sup 14}C measurements. (author)

  15. Distribution and biomarkers of Carbon-14 labeled fullerene C60 ([14C(U)]C60) in female rats and mice for up to 30 days after intravenous exposure

    Science.gov (United States)

    Sumner, Susan C. J.; Snyder, Rodney W.; Wingard, Christopher; Mortensen, Ninell P.; Holland, Nathan A.; Shannahan, Jonathan H.; Dhungana, Suraj; Pathmasiri, Wimal; Han, Li; Lewin, Anita H.; Fennell, Timothy R.

    2016-01-01

    A comprehensive distribution study was conducted in female rats and mice exposed to a suspension of uniformly carbon-14 labeled C60 ([14C(U)]C60). Rodents were administered [14C(U)]C60 (~0.9 mg /kg body weight) or 5% PVP-saline vehicle alone via a single tail vein injection. Tissues were collected at 1 hour, 1, 7, 14 and 30 days after administration. A separate group of rodents received 5 daily injections of suspensions of either [14C(U)]C60 or vehicle with tissue collection 14 days post exposure. Radioactivity was detected in over 20 tissues at all time period. The highest concentration of radioactivity in rodents at each time point was in liver, lungs and spleen. Elimination of [14C(U)]C60 was <2% in urine and feces at any 24 hour time points. [14C(U)]C60 and [14C(U)]C60-retinol were detected in liver of rats and together accounted for ~99% and ~56% of the total recovered at 1 and 30 days post exposure, respectively. The blood radioactivity at 1 hour after [14C(U)]C60 exposure was four-fold higher in rats than in mice; blood radioactivity was still in circulation at 30 days post [14C(U)]C60 exposure in both species (<1%). Levels of oxidative stress markers increased by 5 days after exposure and remained elevated, while levels of inflammation markers initially increased and then returned to control values. The level of cardiovascular marker vWF, increased in rats, but remained at control levels in mice. This study demonstrates that [14C(U)]C60 is retained in female rodents with little elimination by 30 days after i.v. exposure, and leads to systemic oxidative stress. PMID:25727383

  16. Tissue uptake, distribution and elimination of {sup 14}C-PFOA in zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Ulhaq, Mazhar [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Sundström, Maria [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Larsson, Pia; Gabrielsson, Johan [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Bergman, Åke [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Norrgren, Leif [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Örn, Stefan, E-mail: Stefan.Orn@slu.se [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden)

    2015-06-15

    Highlights: • Bioconcentration of PFOA at steady-state was approximately 20–30 times. • High concentrations were observed in bile and intestines implying enterohepatic circulation. • PFOA accumulated in oocytes indicating maternal transfer. - Abstract: Perfluorooctanoic acid (PFOA) is a long-chain perfluorinated chemical that has been shown to be non-degradable and persistent in the environment. Laboratory studies on bioconcentration and compound-specific tissue distribution in fish can be valuable for prediction of the persistence and environmental effects of the chemicals. In the present study male and female zebrafish (Danio rerio) were continuously exposed to 10 μg/L of radiolabeled perfluorooctanoic acid ({sup 14}C-PFOA) for 40 days, after which the exposed fish were transferred to fresh clean water for another 80 days wash-out period. At defined periodic intervals during the uptake and wash-out, fish were sampled for liquid scintillation counting and whole body autoradiography to profile the bioconcentration and tissue distribution of PFOA. The steady-state concentration of {sup 14}C-PFOA in the zebrafish was reached within 20–30 days of exposure. The concentration-time course of {sup 14}C-PFOA displayed a bi-exponential decline during washout, with a terminal half-life of approximately 13–14 days. At steady-state the bioconcentration of {sup 14}C-PFOA into whole-body fish was approximately 20–30 times greater than that of the exposure concentration, with no differences between females and males. The bioconcentration factors for liver and intestine were approximately 100-fold of the exposure medium, while in brain, ovary and gall bladder the accumulation factors were in the range 15–20. Whole-body autoradiograms confirmed the highest labeling of PFOA in bile and intestines, which implies enterohepatic circulation of PFOA. The {sup 14}C-PFOA was also observed in maturing vitellogenic oocytes, suggesting chemical accumulation via yolk proteins

  17. Synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 (dimethyl-1-1 biguanide) hydrochloride; Synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 (dimethyl-1-1 biguanide)

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, M.; Pichat, L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    A description of the synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 hydrochloride passing through the {sup 14}C{sub 2} dicyandiamide. The overall yield with respect to Ba{sup 14}CO{sub 3} is 38 per cent. (author) [French] Description de la synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 par l'intermediaire de la dicyandiamide {sup 14}C{sub 2}. Le rendement global par rapport a {sup 14}CO{sub 3}Ba est de 38 pour cent. (auteur)

  18. Changes in the level of ( sup 14 C)indole-3-acetic acid and ( sup 14 C)indoleacetylaspartic acid during root formation in mung bean cuttings. [Vigna radiata

    Energy Technology Data Exchange (ETDEWEB)

    Norcini, J.G.; Heuser, C.W. (Pennsylvania State Univ., University Park (USA))

    1988-04-01

    Changes in the levels of ({sup 14}C)indole-3-acetic acid (IAA) and ({sup 14}C)indoleacetylaspartic acid (IAAsp) were examined during adventitious root formation in mung bean (Vigna radiata (L.) R. Wilcz. Berken) stem cuttings. IAAsp was identified by GC-MS as the primary conjugate in IAA-treated cuttings. During root formation in IAA-treated cuttings, the level of ({sup 14}C)IAAsp increased rapidly the first day and then declined; ({sup 14}C)IAA was rapidly metabolized and not detected after 12 hours.

  19. Determination of chemical forms of (14)C in liquid discharges from nuclear power plants.

    Science.gov (United States)

    Svetlik, I; Fejgl, M; Povinec, P P; Kořínková, T; Tomášková, L; Pospíchal, J; Kurfiřt, M; Striegler, R; Kaufmanová, M

    2017-10-01

    Developments of radioanalytical methods for determination of radiocarbon in wastewaters from nuclear power plants (NPP) with pressurized light water reactors, which would distinguish between the dissolved organic and inorganic forms have been carried out. After preliminary tests, the method was used to process pilot samples from wastewater outlets from the Temelín and Dukovany NPPs (Czech Republic). The results of analysis of pilot water samples collected in 2015 indicate that the instantaneous (14)C releases into the water streams would be about 7.10(-5) (Temelín) and 4.10(-6) (Dukovany) of the total quantity of the (14)C liberated into the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

    Directory of Open Access Journals (Sweden)

    A. P. Atkinson

    2014-06-01

    14C ages are between 100 and 10 000 years. 3H activities are negligible in most of the groundwater and groundwater electrical conductivity in individual areas remains constant over the period of study. Although diffuse local recharge is evident, the depth to which it penetrates is limited to the upper 10 m of the aquifer. Rather, groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High, and acts as a regional discharge zone where upward head gradients are maintained annually, limiting local recharge. Additionally, the Gellibrand River does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

  1. {sup 14}C-labeling of a novel atypical {beta}-adrenoceptor agonist, SM-11044

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Motohiro; Kanamaru, Hiroshi; Nishioka, Kazuhiko [Sumitomo Chemical Co. Ltd., Hyogo (Japan). Environmental Health Science Lab.

    1996-03-01

    (2S,3R)-2-[3-(4-Fluorophenyl)]propylamino-3-(3,4-dihydroxyphen yl)-3-hydroxypropionic acid pyrrolidine amide hydrobromide (SM-11044) was labeled with carbon-14 for use in mammalian metabolic studies. Grignard reaction of 3,4-methylenedioxyphenylmagnesium bromide with [{sup 14}C]carbon dioxide liberated from barium [{sup 14}C]carbonate (6) gave the acid (5). Reduction of 5 with lithium aluminium hydride followed by oxidation of the resulting benzyl alcohol (11) with chromium oxide-pyridine complex afforded the aldehyde (3). Condensation of 3 with the optically active (R)-oxazolidinone (10) yielded the alcohol (12). Catalytic hydrogenation of 12 and subsequent hydrolysis produced the optically active {beta}-hydroxy-{alpha}-amino acid (2), which was treated with N-carbomethoxyphthalimide to give the hydroxy acid (13). (author).

  2. Hydrogen bond disruption in DNA base pairs from (14)C transmutation.

    Science.gov (United States)

    Sassi, Michel; Carter, Damien J; Uberuaga, Blas P; Stanek, Christopher R; Mancera, Ricardo L; Marks, Nigel A

    2014-09-04

    Recent ab initio molecular dynamics simulations have shown that radioactive carbon does not normally fragment DNA bases when it decays. Motivated by this finding, density functional theory and Bader analysis have been used to quantify the effect of C → N transmutation on hydrogen bonding in DNA base pairs. We find that (14)C decay has the potential to significantly alter hydrogen bonds in a variety of ways including direct proton shuttling (thymine and cytosine), thermally activated proton shuttling (guanine), and hydrogen bond breaking (cytosine). Transmutation substantially modifies both the absolute and relative strengths of the hydrogen bonding pattern, and in two instances (adenine and cytosine), the density at the critical point indicates development of mild covalent character. Since hydrogen bonding is an important component of Watson-Crick pairing, these (14)C-induced modifications, while infrequent, may trigger errors in DNA transcription and replication.

  3. Production of 14C-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea.

    Science.gov (United States)

    Boyce, J M; Mitchell, E B; Knapp, J S; Buttke, T M

    1985-09-01

    Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. 14C-labeled gas was produced significantly faster (P less than 0.02) by N. gonorrhoeae than by N. cinerea. Additional studies suggested that the 14C-labeled gas produced by N. cinerea was carbon dioxide. N. cinerea strains were similar to Branhamella catarrhalis strains because both species failed to produce detectable acid from glucose, maltose, sucrose, fructose, and lactose in cysteine-tryptic agar media. However, in contrast to N. cinerea strains, B. catarrhalis strains did not metabolize glucose in BACTEC Neisseria Differentiation kits.

  4. Cluster structure of neutron-rich 10Be and 14C via resonant alpha scattering

    Science.gov (United States)

    Suzuki, D.; Ahn, T.; Bazin, D.; Becchetti, F. D.; Beceiro-Novo, S.; Fritsch, A.; Kolata, J. J.; Mittig, W.; AT-TPC Collaboration

    2017-09-01

    Neutron-rich ^{10} Be and ^{14} C nuclei were studied via resonant α scattering of radioactive 6 He and ^{10} Be beams, respectively, produced by the TwinSol facility at the University of Notre Dame. The Prototype Active-Target Time-Projection Chamber (pAT-TPC) was used as a thick gaseous α target to induce resonant scattering and as a device to track reacted particles inside the target, providing continuous excitation functions and angular distributions over a wide range of energies and angles. The experimental results indicate a melting phenomenon of α clusters in the 4+ rotational member of the ^{10} Be ground state and a linear chain alignment of three α clusters in ^{14} C excited states, as recently predicted by an anti-symmetrized molecular dynamics calculation.

  5. Two-nucleon excitation from $p$ to $sd$ shell in $^{12,14}$C

    CERN Document Server

    Yuan, Cenxi; Lan, Nianwu; Fang, Youjun

    2016-01-01

    The effect of the two-nucleon excitation from $p$ to $sd$ shell is discussed in $^{12}$C and $^{14}$C in the frame work of shell model. The recently suggested shell-model Hamiltonian YSOX provides an suitable tool to investigate the $2~\\hbar\\omega$ excitation in $psd$ region. Because the strength of the $$ interaction, which represents the interaction between the $0~\\hbar\\omega$ and $2~\\hbar\\omega$ configurations, is considered in the construction of the YSOX. The level of $^{12}$C is almost independent on the $$ interaction, but excitation energies of certain states in $^{14}$C are strongly affected by it. Further investigation shows that the percentage of $2~\\hbar\\omega$ configuration in these states is quite different from that of the ground state.

  6. Fate of 15N and 14C from labelled plant material

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Gjettermann, Birgitte; Eriksen, Jørgen;

    2008-01-01

    strength of labelled plant residues in dissolved inorganic N (DIN) and dissolved organic N (DON) in pore water from the plough layer, and (ii) the plant uptake of organically bound N. Litterbags containing 14C- and 15N-labelled ryegrass or clover roots or leaves were inserted into the sward of a ryegrass......–clover mixture in early spring. The fate of the released 14C and 15N was monitored in harvested biomass, roots, soil, and pore water percolating from the plough layer. No evidence of plant uptake of dual-labelled organic compounds from the dual-labelled residues could be observed. N in pore water from the plough...... water originating from plant residues only constituted 1.5% of the total dissolved N from the plough layer....

  7. Ochratoxin A labelled with /sup 14/C or /sup 3/H in the phenylalanine moiety

    Energy Technology Data Exchange (ETDEWEB)

    Hult, K.

    1986-08-01

    Ochratoxin A is a mycotoxin produced by Aspergillus and Penicillium moulds. The toxin is an amide formed between phenylalanine and the isocoumarin acid ochratoxin ..cap alpha... Ochratoxin A with high specific radioactivity can be obtained, by substitution of the natural phenylalanine for /sup 14/C of /sup 3/H-labelled phenylalanine. Labelled ochratoxin A was formed by condensation of labelled phenylalanine ethylester with an anhydride derivative of ochratoxin ..cap alpha... The intermediate O-acetyl ochratoxin C was hydrolysed with pig liver esterase and chymotrypsin to afford ochratoxin A. The overall yield of radioactivity was 50%. Specific activities up to 500 Ci/mol and 100 ci/mmol for /sup 14/C and /sup 3/H respectively were obtained.

  8. From 14C/12C measurements towards radiocarbon dating of ice

    NARCIS (Netherlands)

    Oerlemans, J.; Wal, R.S.W. van de; Roijen, J.J. van; Raynaud, D.; Borg, K. van der; Jong, A.F.M. de; Lipenkov, V.; Huybrechts, P.

    1994-01-01

    A dry extraction method of CO2 included in glacier ice adds a contamination equivalent to 1.8 μg modern carbon for a 35 μg C sample. This enables radiocarbon dating by accelerator mass spectrometry of 35 μg C samples to about 25 000 BP. Measured 14C/12C ratios are presented for a part of the Vostok

  9. Production of 14C-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea.

    OpenAIRE

    Boyce, J M; Mitchell, E B; Knapp, J S; Buttke, T M

    1985-01-01

    Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. 14C-labeled gas was produced significantly faster (P less tha...

  10. Dynamics of {sup 14}C-labeled glucose and ammonium in saline arable soils

    Energy Technology Data Exchange (ETDEWEB)

    Vuelvas-Solorzano, Alma; Hernandez-Matehuala, Rosalina [Instituto Tecnologico de Celaya, Celaya Gto. (Mexico). Dept. de Ing. Bioquimica. Lab. de Bioingenieria; Conde-Barajas, Eloy; Cardenas-Manriquez, Marcela [Instituto Tecnologico de Celaya, Celaya Gto. (Mexico). Dept. de Ing. Ambiental. Lab. de Bioingenieria], e-mail: marcela@itc.mx; Luna-Guido, Marco L.; Dendooven, Luc [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (Cinvestav), D.F. (Mexico). Dept. de Biotecnologia y Bioingenieria. Lab. de Ecologia de Suelos], e-mail: dendoove@cinvestav.mx

    2009-07-15

    Organic matter dynamics and nutrient availability in saline agricultural soils of the State of Guanajuato might provide information for remediation strategies. {sup 14}C labeled glucose with or without 200 mg kg{sup -}1 of NH{sub 4} {sup +}-N soil was added to two clayey agricultural soils with different electrolytic conductivity (EC), i.e. 0.94 dS m{sup -}1 (low EC; LEC) and 6.72 dS m{sup -}1 (high EC; HEC), to investigate the effect of N availability and salt content on organic material decomposition. Inorganic N dynamics and production of CO{sub 2} and {sup 14}CO{sub 2} were monitored. Approximately 60 % of the glucose-{sup 14}C added to LEC soil evolved as {sup 14}CO{sub 2}, but only 20 % in HEC soil after the incubation period of 21 days. After one day, < 200 mg {sup 14}C was extractable from LEC soil, but > 500 mg {sup 14}C from HEC soil. No N mineralization occurred in the LEC and HEC soils and glucose addition reduced the concentrations of inorganic N in unamended soil and soil amended with NH{sub 4}{sup +}-N. The NO{sub 2}{sup -} and NO{sub 3}{sup -} concentrations were on average higher in LEC than in HEC soil, with exception of NO{sub 2}{sup -} in HEC amended with NH{sub 4}{sup +}-N. It was concluded that increases in soil EC reduced mineralization of the easily decomposable C substrate and resulted in N-depleted soil. (author)

  11. Biocomponent determination in vinegars with the help of 14C measured by liquid scintillation counting.

    Science.gov (United States)

    Tudyka, Konrad; Pawlyta, Jacek

    2014-02-15

    This article presents a method of carbon extraction from vinegar used in preparation of liquid scintillation counting cocktails for measurements of low (14)C radioactivity. The presented method is relatively fast and can be used to produce liquid scintillation cocktails e.g., via benzene synthesis. In this work we present specific radiocarbon radioactivity determinations and based on them estimation of bio product content for five commercially available vinegars. All investigated vinegars are likely produced from plants in fermentation process.

  12. Release of ( sup 14 C)5-hydroxytryptamine from human platelets by red wine

    Energy Technology Data Exchange (ETDEWEB)

    Jarman, J.; Glover, V.; Sandler, M. (Queen Charlotte' s and Chelsea Hospital, London (England))

    1991-01-01

    Red wine, at a final dilution of 1/50, caused released of ({sup 14}C)5-hydroxytryptamine (5-HT) from preloaded platelets, an effect which was not observed with any white wines or beers tested. Since 5-HT, is probably released from body stores during migraine attacks and red wine is known to provoke migraine episodes in susceptible individuals, release of 5-HT, possibly from central stores, could represent a plausible mechanism for its mode of action.

  13. In vitro uptake of /sup 14/C-praziquantel by cestodes, trematodes, and a nematode

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, P.; Thomas, H.; Weber, H.

    1980-12-01

    /sup 14/C-praziquantel was rapidly taken up by Schistosoma mansoni, Fasciola hepatica, Hymenolepis nana, and isolated strobilocerci of Taenia taeniaeformis. Schistosoma mansoni lost praziquantel rapidly to drug-free medium. Chromatography of extracts prepared after incubation of S. mansoni and H. nana yielded no indication that praziquantel was metabolized. Autoradiography revealed a uniform distribution of praziquantel throughout the tissues of S. mansoni and H. nana. Uptake was considerably slower in the nematode Heterakis spumosa and apparently via the oral route.

  14. Daily production and consumption in an eelgrass (Zostera marina) community in saline Lake Grevelingen: discrepancies between the O/sub 2/ and /sup 14/C method

    Energy Technology Data Exchange (ETDEWEB)

    Lindeboom, H.J.; de Bree, B.H.H. (Delta Institute for Hydrobiological Research, Yerseke (Netherlands))

    1982-12-01

    During seven 28-hour measurement periods in 1980 and 1981 the oxygen production and consumption in an eelgrass community in Lake Grevelingen (Netherlands) were determined using light and dark plexiglass enclosures. Applying an oxygen to carbon conversion factor of 0.29 the amount of carbon fixed and the amount of organic carbon consumed were estimated. During the daylight period a net production was found, whereas over 24 hours a net production in spring and a net consumption later in the year were found. On an annual basis, production and consumption were approximately equal, with a net production occurring in the over-ground eelgrass community and a net consumption in the sediment. Close to the plexiglass enclosures samples were taken in order to measure primary production with the /sup 14/C method. Comparison of the results of the O/sub 2/ and /sup 14/C methods showed that the first yielded considerably higher C fixation values (1.2 to 2.0 times for the production of Zostera marina and 2.7 to 5.4 times for that of the microphytobenthos). Production values assessed with the /sup 14/C method in comparison with the consumption values assessed with the O/sub 2/ method were always much too low, and a carbon mass balance based on the two methods fails.

  15. Accelerator mass spectrometry best practices for accuracy and precision in bioanalytical (14)C measurements.

    Science.gov (United States)

    Vogel, John S; Giacomo, Jason A; Schulze-König, Tim; Keck, Bradly D; Lohstroh, Peter; Dueker, Stephen

    2010-03-01

    Accelerator mass spectrometers have an energy acceleration and charge exchange between mass definition stages to destroy molecular isobars and allow single ion counting of long-lived isotopes such as (14)C (t½=5370 years.). 'Low' voltage accelerations to 200 kV allow laboratory-sized accelerator mass spectrometers instruments for bioanalytical quantitation of (14)C to 2-3% precision and accuracy in isolated biochemical fractions. After demonstrating this accuracy and precision for our new accelerator mass spectrometer, we discuss the critical aspects of maintaining quantitative accuracy from the defined biological fraction to the accelerator mass spectrometry quantitation. These aspects include sufficient sample mass for routine rapid sample preparation, isotope dilution to assure this mass, isolation of the carbon from other sample combustion gasses and use of high-efficiency biochemical separations. This review seeks to address a bioanalytical audience, who should know that high accuracy data of physiochemical processes within living human subjects are available, as long as a (14)C quantitation can be made indicative of the physiochemistry of interest.

  16. Accelerated degradation of (14)C-atrazine in brazilian soils from different regions.

    Science.gov (United States)

    Martinazzo, Rosane; Jablonowski, Nicolai D; Hamacher, Georg; Dick, Deborah P; Burauel, Peter

    2010-07-14

    The repeated use of a given pesticide may induce a selection of the soil microbial population, resulting in a rapid degradation of the respective xenobiotic. Patterns of atrazine degradation (mineralization, formation of metabolites and nonextractable residues (NER)) were evaluated in two Brazilian soils with a history of atrazine application. Results were compared with those obtained from soils that had no agricultural use or herbicide application history. (14)C-Atrazine mineralization in unsaturated treated soils was high. By the 85th day of incubation, 82% of the applied (14)C-atrazine was mineralized in the Rhodic Hapludox and 74% in the Xanthic Haplustox. Mineralization remained low in nontreated soils (atrazine mineralization in the treated Xantic Haplustox and surprisingly also in the nontreated Rhodic Hapludox (98 and 83% on the 85th day, respectively), whereas in the other samples the evolved (14)CO(2) did not differ (p atrazine directly after (14)C-atrazine application was higher in both Xanthic Haplustox samples (around 80% of applied atrazine) in comparison to the Rhodic Hapludox samples (around 60%). Extractable activity and the formation of metabolites and NER varied among the studied soils according to the atrazine application history rather than the soil characteristics.

  17. Transfer of 14C-photosynthate to the sporocarp of an ectomycorrhizal fungus Laccaria amethystina.

    Science.gov (United States)

    Teramoto, Munemasa; Wu, Bingyun; Hogetsu, Taizo

    2012-04-01

    Sporocarps of ectomycorrhizal fungi are strong carbon sinks for the source in host trees, but the details of carbon transfer from the host to the sporocarp are unknown. In this study, single seedlings of Japanese red pine (Pinus densiflora) colonised by Laccaria amethystina were grown on floral foam plates fitted in rhizoboxes, resulting in fruiting on the substrate. The seedlings were photosynthetically labelled with (14)CO(2); (14)C-labelled photosynthate transfer from leaves to sporocarps was then chased using a time-course autoradiography technique. (14)C was transferred to healthy, fresh sporocarps in a purple colour ranging from primordial to elongate sporocarps, but hardly to senesced ones that had faded to white or grey, or browned. This suggested that C is transferred only to physiologically active sporocarps. Two seedlings associated with a growing sporocarp were labelled again 7 and 16 days after the first labelling, respectively. (14)C accumulation in the sporocarps rose in a stepwise manner after the second labelling, indicating that sporocarps mainly used recently rather than previously photosynthesised C.

  18. 14C-urea breath test in patients undergoing anti-tuberculosis therapy

    Institute of Scientific and Technical Information of China (English)

    Sayed Amir Mirbagheri; Amir Ali Sohrabpour; Mehrdad Hasibi; Babak Moghimi; Mehdi Mohamadnejad

    2005-01-01

    AIM: Urea breath test (UBT) is a non-invasive diagnostic test for detecting the presence of Helicobacter pylori(H pylori).In this study we evaluated the effect of anti-tuberculosis therapy on the results of 14C-UBT.METHODS: Patients, with the diagnosis of tuberculosis (TB) who had a positive UBT at the point of starting antiTB therapy, were included. None had a history of peptic ulcer disease or had taken antibiotics, bismuth compounds and/or PPI in the previous month, 14C-UBT was repeated at the end of the second month and the end of treatment period and one month after completion of treatment course.RESULTS: Thirty-five patients (23 males) were enrolled.14C-UBT was negative in all 35 patients (100%) at the end of the second month and remained negative in 30cases (85.7%) at the end of the treatment course. One month after completion of treatment course, UBT remained negative in 13 patients (37.1%).CONCLUSION: Our report underscores the need for caution while interpreting urea breath test results in patients undergoing anti-TB therapy. Furthermore, the combination of drugs used in this study resulted in H pylori eradication in a minority of patients.

  19. Comparison of different soil organic matter fractionation methodologies: Evidences from ultrasensitive {sup 14}C measurements

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.i [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Lubritto, Carmine; Galdo, Ilaria Del; D' Onofrio, Antonio [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Cotrufo, M. Francesca [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy); Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado (United States); Terrasi, Filippo [CIRCE, Dipartimento di Scienze Ambientali, Seconda Universita degli studi di Napoli and INNOVA, Via Vivaldi, 43, Caserta 81100 (Italy)

    2010-04-15

    Soils are studied with the aim to predict future climatic scenarios and find the best guidelines to manage terrestrial ecosystems for the mitigation of the atmospheric CO{sub 2} rising. Carbon constituting soil organic matter (SOM) behaves as a cohort of different pools, characterized by a specific C turnover time. Both natural and anthropogenic occurring {sup 14}C reach the soil through plant littering, becoming a valid tool to trace SOM dynamics. In this study we present a series of Accelerator Mass Spectrometry (AMS) {sup 14}C measurements on SOM samples obtained by means of different laboratory protocols used for the isolation of soil pools from bulk soil (fractionation protocols). Radiocarbon signature of SOM fractions is used as a keyhole to look at the more effective fractionation procedure and comparison among measured {sup 14}C on SOM fractions revealed important indications for the proposal of a novel fractionation protocol. Our data put in evidence how particle size controls the recalcitrance of ancient SOM carbon pools.

  20. Trojan horse method with neutrons induced reactions: The 17O(n,α)14C reaction

    Science.gov (United States)

    Guardo, G. L.; Spitaleri, C.; Lamia, L.; Gulino, M.; Tang, X.; Bucher, B.; Burjan, V.; Couder, M.; Davies, P.; deBoer, R.; Fang, X.; Kroha, V.; La Cognata, M.; Ma, C.; Mrazek, J.; Mukhamedzhanov, A.; Notani, M.; O'Brien, S.; Pizzone, R. G.; Rapisarda, G. G.; Roberson, D.; Sergi, M. L.; Tan, W.; Wiescher, M.

    2017-06-01

    The experimental study of the 17O(n,α)14C reaction has been performed in the energy range 0-350 keV. This reaction could play an important role in explaining heavy elements (s-process) nucleosynthesis in various astrophysical scenario. To over-come the practical problems arising from the neutrons production, a new application of the Trojan Horse Method has been recently suggested. In more details, the 17O(n,α)14C reaction has been studied using the quasi-free 2H(17O,α14C)1H reaction, induced at an energy of 43.5 MeV. The measurement allows one to investigate the ℓ=3, 75 keV resonance (E*=8.125 MeV, Jπ=5-), absent in the available direct measurements because of centrifugal suppression effects. Moreover, the results show that the contribution of the 166 keV and 236 keV resonances is in energy agreement with the available direct data. A clear contribution of the -7 keV subthreshold level is also present.

  1. Oxidation of [1,12-14C]dodecanedioic acid by rat pancreatic islets.

    Science.gov (United States)

    Malaisse, W J; Greco, A V; Mingrone, G

    2000-10-01

    Several aliphatic dioic acids were recently reported to stimulate insulin release in isolated rat pancreatic islets incubated at close-to-physiological D-glucose concentrations. In order to gain insight into the mode of action of these acids in pancreatic islet B-cells, the oxidation of [1,12-14C]dodecanedioic acid (5.0 mM) was now measured in rat islets. Expressed as pmol of [1, 12-14C]dodecanedioic acid equivalent, the production of 14CO2 was close to 1.0 pmol/islet per 120 min, representing about 8% of that attributable to the oxidation of D-[U-14C]-glucose (8.3 mM). The dioic acid and the hexose failed to exert any significant reciprocal effect upon their respective oxidation rate. These findings support the view that the insulinotropic action of dodecanedioic acid, and presumably other aliphatic dioic acids, is causally linked to their capacity to act as nutrients in pancreatic islet cells.

  2. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  3. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  4. Modeling of irradiated graphite (14)C transfer through engineered barriers of a generic geological repository in crystalline rocks.

    Science.gov (United States)

    Poskas, Povilas; Grigaliuniene, Dalia; Narkuniene, Asta; Kilda, Raimondas; Justinavicius, Darius

    2016-11-01

    There are two RBMK-1500 type graphite moderated reactors at the Ignalina nuclear power plant in Lithuania, and they are under decommissioning now. The graphite cannot be disposed of in a near surface repository, because of large amounts of (14)C. Therefore, disposal of the graphite in a geological repository is a reasonable solution. This study presents evaluation of the (14)C transfer by the groundwater pathway into the geosphere from the irradiated graphite in a generic geological repository in crystalline rocks and demonstration of the role of the different components of the engineered barrier system by performing local sensitivity analysis. The speciation of the released (14)C into organic and inorganic compounds as well as the most recent information on (14)C source term was taken into account. Two alternatives were considered in the analysis: disposal of graphite in containers with encapsulant and without it. It was evaluated that the maximal fractional flux of inorganic (14)C into the geosphere can vary from 10(-11)y(-1) (for non-encapsulated graphite) to 10(-12)y(-1) (for encapsulated graphite) while of organic (14)C it was about 10(-3)y(-1) of its inventory. Such difference demonstrates that investigations on the (14)C inventory and chemical form in which it is released are especially important. The parameter with the highest influence on the maximal flux into the geosphere for inorganic (14)C transfer was the sorption coefficient in the backfill and for organic (14)C transfer - the backfill hydraulic conductivity.

  5. Remarkable increase in 14C-acetate uptake in an epilepsy model rat brain induced by lithium-pilocarpine.

    Science.gov (United States)

    Hosoi, Rie; Kitano, Daisuke; Momosaki, Sotaro; Kuse, Kenji; Gee, Antony; Inoue, Osamu

    2010-01-22

    The present study demonstrates changes in rat brain glial metabolism during the acute phase of epilepsy. Status epilepticus (SE) was induced using the lithium-pilocarpine model. Glial metabolism was measured with (14)C-acetate. Local cerebral blood flow and glucose metabolism were also measured using (14)C-N-isopropyl-p-iodoamphetamine (IMP) and (14)C-2-deoxyglucose (2DG), respectively. At the initiation of the seizure, (14)C-acetate uptake did not change significantly. However, a marked increase was observed 2 h after the pilocarpine injection in all brain regions studied. The increase of brain uptake was transient, and the maximum enhancement was seen at 2 h after the pilocarpine injection. The increase of (14)C-acetate uptake was almost to the same degree in all regions, whereas (14)C-IMP and (14)C-2DG uptakes showed a heterogeneous increase. In the case of (14)C-IMP, the highest increase was observed in the thalamus (280%), and a moderate increase (120 to 150%) was seen in the orbital cortex, cingulate cortex and pyriform cortex. (14)C-2DG uptake increased by 130 to 240% in most regions of the brain, however, an increase of only 40 and 20% was observed in the cerebellum and pons-medulla, respectively. These results demonstrated that glial energy metabolism was markedly enhanced during a prolonged seizure. To our knowledge, this study is the first observation showing large and widespread glial metabolic increases in the rat brain during status epilepticus.

  6. Utilization of [14C]phenylalanine derived from arylphorin or free amino acid in Manduca sexta pharate adults

    Science.gov (United States)

    Wu, M.; Tischler, M. E.

    1995-01-01

    The role of arylphorin as a storage protein was studied using 14C-arylphorin. 14C-arylphorin was produced optimally by incubating one-half fat body from Manduca sexta fifth instar larvae at 22 degrees C for 24 h, in 1 ml of medium containing amino acids at 25% of their physiological concentration with [U-14C]-phenylalanine (phe) provided initially without nonlabeled phenylalanine. Nonlabeled phe was provided after 1 h at 16% of its physiological concentration. The specific activity of 14C-arylphorin produced in vitro was 30 times greater than that generated in vivo. Injection of 14C-arylphorin into pharate adults was used to study the distribution of 14C-phe derived from this protein into 14CO2 and tissues for comparison with injection of free 14C-phe during the middle (days 6 to 12 pharate adult) and late (days 12 to 17 pharate adult) stages of adult development. Appearance of 14CO2 from 14C-arylphorin as compared to 14C-phenylalanine showed a slower time course during both the middle and late stages of development, in keeping with the time needed for degradation of the protein. In accord with faster phe turnover near the end of adult development, total 14CO2 production was greater and the retention of 14C in hemolymph and fat body was less compared to the middle stage of development regardless of whether 14C-arylphorin or 14C-phe was injected. In the middle stage of development, the appearance of 14C in the cuticle and head parts was greater, whereas incorporation into abdomen and thorax was less than during the late stage of development. Since the pattern of 14C distribution from 14C-arylphorin and 14C-phe was similar, one major function of arylphorin must be as a storage protein replenishing the supply of free amino acids used for synthesis of adult tissues. These results also suggest a limited contribution of M. sexta arylphorin to formation of the cuticle subsequent to day-6 pharate adult.

  7. Analysis of {sup 14}CO{sub 2} trapped {sup 14}C Sorbent, and {sup 14}C and {sup 3}H Radioactivity Determination in Resins and Oils from Nuclear Power Plants Using a Combustion Method

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Young Gun; Kim, Chang Jong; Choi, Geun Sik; Chung, Kun Ho; Kang, Mun Ja [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Tritium ({sup 3}H, T) generated in the heavy water and C fourteen ({sup 14}C) originated from the graphite moderator or structural materials of the nuclear power plant can cause acute and/or chronic harmful effects by inhalation and ingestion of these radionuclides owing to their binding affinity toward biomolecules and gas phase. {sup 3}H and {sup 14}C radioactivity in ion exchange resins and oils from nuclear power plants were determined by an oxidation (combustion) method. The 0.1 M HNO{sub 3} solution and the {sup 14}C sorbent trapped the {sub 3}H and {sup 14}C respectively in the gas from the combustion of samples. All samples were burned without ash in the combustion system. The reaction of CO{sub 2} and {sup 14}C sorbent was investigated by FT-IR analysis. The study demonstrated the different reaction mechanism according to the CO{sub 2} concentration. In the FT-IR study, it is clearly confirmed that CO{sub 2} from the burned 1 g of sample can be trapped in the {sup 14}C sorbent completely. During the reaction of CO{sub 2} and {sup 14}C sorbent, the temperature and the viscosity of {sup 14}C sorbent increased due to the decrease of enthalpy change and the bonding between each molecules of the sorbent. We expect that our FT-IR study could motivate the development of {sup 14}C sorbent and confirm the {sup 14}C trapping performance of the {sup 14}C sorbent.

  8. Metabolism of 35S- and 14C-labeled 1-methyl-2-mercaptoimidazole in vitro and in vivo.

    Science.gov (United States)

    Taurog, A; Dorris, M L; Guziec, F S

    1989-01-01

    We previously described an in vitro incubation system for studying the mechanism of inhibition of thyroid peroxidase (TPO)-catalyzed iodination by the antithyroid drug 1-methyl-2-mercaptoimidazole (MMI). Inhibition of iodination in this system may be reversible or irreversible, depending on the relative concentrations of iodide and MMI and on the TPO concentration. Metabolism of the drug occurs under both conditions, and in the present investigation we used 35S- and 14C-labeled MMI together with reverse phase HPLC to examine the metabolic products associated with reversible and irreversible inhibition of iodination by MMI. Under conditions of reversible inhibition, MMI was rapidly metabolized and disappeared completely from the incubation mixture. With [35S]MMI, the earliest detectable 35S-labeled product was MMI disulfide, which reached a peak after a few minutes and then declined to undetectable levels. Coincident with the decrease in disulfide was the appearance of two 35S peaks, the major one corresponding to sulfate/sulfite, and the other to a component eluting at 7.5 min. Similar results were obtained for the disulfide and for the 7.5 min metabolite with [14C]MMI. The major 14C-labeled metabolite containing no S appeared to be 1-methylimidazole. Under conditions of irreversible inhibition, MMI disulfide was also the earliest detectable 35S-labeled metabolite. However, MMI decreased more slowly, and after reaching a nadir at about 6 min returned gradually to a level about halfway between the initial and the minimum value. The reformation of MMI appeared to involve the nonenzymatic disproportionation of MMI disulfide. Formation of the 7.5 min peak was also observed, but there was no formation of sulfate/sulfite. The difference in metabolic pattern between the reversible and irreversible conditions is primarily related to the rapid inactivation of TPO that occurs under irreversible conditions. The metabolism of [35S]MMI in thyroids of rats injected with the

  9. Large spatial variations in coastal 14C reservoir age – a case study from the Baltic Sea

    Directory of Open Access Journals (Sweden)

    B. C. Lougheed

    2013-05-01

    Full Text Available Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R (t, associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R (t was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R (t values, indicative of hard-water effects. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R (t and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R (t for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R (t, although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is found between δ18Oaragonite and Macoma R (t, suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R (t, due to the δ18Oaragonite signal being dominated by the salinity gradient of the Baltic Sea. A slightly increased correlation can be expected when δ18Oaragonite is corrected for temperature fractionation effects. The results of this Baltic Sea case study, which show that R (t is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R (t is also likely to

  10. Does the 14C method estimate net photosynthesis? II. Implications from cyclostat studies of marine phytoplankton

    Science.gov (United States)

    Pei, Shaofeng; Laws, Edward A.

    2014-09-01

    Two species of marine phytoplankton, Isochrysis galbana and Chlorella kessleri, were grown in a continuous culture system on a 12-h:12-h light:dark cycle of illumination under nitrate-limited growth conditions. At growth rates of ~1 d-1, production rates estimated from 14C uptake were not significantly different from production rates estimated from changes in particulate organic carbon (POC) and total organic carbon (TOC). At growth rates of ~0.35 d-1, however, production rates based on uptake of 14C significantly (p<0.05) overestimated production rates based on changes in POC and TOC in all cases for C. kessleri and after 24 h for I. galbana. The ratio of production based on 14C uptake to production based on changes in POC and TOC concentrations was in all cases higher after 24 h than after 12 h. The extent of overestimation after a 24-h incubation at ~0.35 d-1 was about 23 and 40% in the cases of I. galbana and C. kessleri, respectively. Dark respiration rates estimated from changes in 14C activity during the dark period were lower than the rates estimated from changes of POC and TOC concentrations during the 12 h of darkness because only about 73% of the carbon respired during the dark period had been fixed during the previous 12-h photoperiod. The fact that the 14C method tends to overestimate net carbon assimilation by a greater percentage at low growth rates than at high growth rates probably reflects the greater efficiency of intracellular recycling of respired CO2 at high growth rates. The fact that the extent of overestimation is greater when cells are grown on a light:dark cycle probably reflects the fact that not all carbon respired in the dark was fixed during the previous photoperiod and that intracellular recycling of respired CO2 during the photoperiod is inefficient during some phases of the synchronized growth that tends to be entrained by light:dark cycles.

  11. Source and age of carbon in peatland surface waters: new insights from 14C analysis

    Science.gov (United States)

    Billett, Michael; Garnett, Mark; Dinsmore, Kerry; Leith, Fraser

    2013-04-01

    Peatlands are a significant source of carbon to the aquatic environment which is increasingly being recognised as an important flux pathway (both lateral and vertical) in total landscape carbon budgets. Determining the source and age of the carbon (in its various forms) is a key step to understanding the stability of peatland systems as well as the connectivity between the soil carbon pool and the freshwater environment. Novel analytical and sampling methods using molecular sieves have been developed for (1) within-stream, in situ sampling of CO2 in the field and (2) for the removal/separation of CO2 in the laboratory prior to 14C analysis of CH4. Here we present dual isotope (δ13C and 14C) data from freshwater systems in UK and Finnish peatlands to show that significant differences exist in the source and age of CO2, DOC (dissolved organic carbon) and POC (particulate organic carbon). Individual peatlands clearly differ in terms of their isotopic freshwater signature, suggesting that carbon cycling may be "tighter" in some systems compared to others. We have also measured the isotopic signature of different C species in peatland pipes, which appear to be able to tap carbon from different peat depths. This suggests that carbon cycling and transport within "piped-peatlands" may be more complex than previously thought. Some of our most recent work has focussed on the development of a method to measure the 14C component of CH4 in freshwaters. Initial results suggest that CH4 in peatland streams is significantly older than CO2 and derived from a much deeper source. We have also shown that the age (but not the source) of dissolved CO2 changes over the hydrological year in response to seasonal changes in discharge and temperature. Radiocarbon measurements in the peat-riparian-stream system suggest that a significant degree of connectivity exists in terms of C transport and cycling, although the degree of connectivity differs for individual C species. In summary, 14C

  12. Biodistribution and planar gamma camera imaging of {sup 123}I- and {sup 131}I-labeled F(ab'){sub 2} and Fab fragments of monoclonal antibody 14C5 in nude mice bearing an A549 lung tumor

    Energy Technology Data Exchange (ETDEWEB)

    Burvenich, Ingrid J.G. [Laboratory of Radiopharmacy, University of Ghent, B-9000 Ghent (Belgium)]. E-mail: ingrid.burvenich@ugent.be; Schoonooghe, Steve [Department of Biomedical Research, Flanders Institute of Biotechnology (VIB), University of Ghent, B-9000 Ghent (Belgium); Blanckaert, Peter [Laboratory of Radiopharmacy, University of Ghent, B-9000 Ghent (Belgium); Bacher, Klaus [Department of Medical Physics and Radiation Protection, Ghent University, B-9000 Ghent (Belgium); Vervoort, Liesbet [Laboratory of Radiopharmacy, University of Ghent, B-9000 Ghent (Belgium); Coene, Elisabeth [N. Goormaghtigh Institute of Pathology, Ghent University, B-9000 Ghent (Belgium); Mertens, Nico [Department of Biomedical Research, Flanders Institute of Biotechnology (VIB), University of Ghent, B-9000 Ghent (Belgium); Vos, Filip de [Laboratory of Radiopharmacy, University of Ghent, B-9000 Ghent (Belgium); Slegers, Guido [Laboratory of Radiopharmacy, University of Ghent, B-9000 Ghent (Belgium)

    2007-04-15

    Detection of antigen 14C5, involved in substrate adhesion and highly expressed on the membrane of many carcinomas, including lung cancer, provides important diagnostic information that can influence patient management. The aim of this study was to evaluate the biodistribution and planar gamma camera imaging characteristics of radioiodinated F(ab'){sub 2} and Fab fragments of monoclonal antibody (mAb) 14C5 in tumor-bearing mice. Methods: F(ab'){sub 2} and Fab 14C5 fragments were radioiodinated using the Iodo-Gen method. In vitro stability, binding specificity and affinity of {sup 125}I-labeled 14C5 fragments were studied in A549 lung carcinoma cells. Biodistribution, blood clearance and tumor-targeting characteristics of {sup 131}I-labeled 14C5 fragments and intact mAb 14C5 were studied in Swiss nu/nu mice bearing A549 lung carcinoma tumors. Planar gamma imaging illustrated the potential use of these {sup 123}I-labeled 14C5 fragments for radioimmunodetection (RID). Results: Saturation binding experiments showed highest affinity for {sup 125}I-labeled F(ab'){sub 2} fragments (K {sub d}=0.37{+-}0.10 nmol/L) and lowest affinity for {sup 125}I-labeled Fab fragments (K {sub d}=2.25{+-}0.44 nmol/L). Blood clearance studies showed that the alpha half-life (t1/2{alpha}) value for Fab, F(ab'){sub 2} and mAb 14C5 was 14.9, 21 and 118 min, respectively. The beta half-life t1/2{beta} value for Fab, F(ab'){sub 2} and mAb 14C5 was 439, 627 and 4067 min, respectively. {sup 131}I-Fab fragments showed highest tumor uptake 3 h after injection (2.4{+-}0.8 %ID/g), {sup 131}I-labeled F(ab'){sub 2} showed highest tumor uptake 6 h after injection (4.7{+-}0.7 %ID/g) and for {sup 131}I-labeled mAb highest tumor uptake was observed at 24 h (10.7{+-}2.3 %ID/g). In planar gamma imaging, both labeled fragments gave better tumor-to-background contrast than {sup 123}I-mAb 14C5. Conclusion: Fab and F(ab'){sub 2} fragments derived from intact mAb 14C5 have

  13. [Quantifying soil autotrophic microbes-assimilated carbon input into soil organic carbon pools following continuous 14C labeling].

    Science.gov (United States)

    Shi, Ran; Chen, Xiao-Juan; Wu, Xiao-Hong; Jian, Yan; Yuan, Hong-Zhao; Ge, Ti-Da; Sui, Fang-Gong; Tong, Cheng-Li; Wu, Jin-Shui

    2013-07-01

    Soil autotrophic microbe has been found numerous and widespread. However, roles of microbial autotrophic processes and the mechanisms of that in the soil carbon sequestration remain poorly understood. Here, we used soils incubated for 110 days in a closed, continuously labeled 14C-CO2 atmosphere to measure the amount of labeled C incorporated into the microbial biomass. The allocation of 14C-labeled assimilated carbon in variable soil C pools such as dissolved organic C (DOC) and microbial biomass C (MBC) were also examined over the 14C labeling span. The results showed that significant amounts of 14C-SOC were measured in paddy soils, which ranged from 69.06-133.81 mg x kg(-1), accounting for 0.58% to 0.92% of the total soil organic carbon (SOC). The amounts of 14C in the dissolved organic C (14C-DOC) and in the microbial biomass C (14C-MBC) were dependent on the soils, ranged from 2.54 to 8.10 mg x kg(-1), 19.50 to 49.16 mg x kg(-1), respectively. There was a significantly positive linear relationship between concentrations of 14C-SOC and 14C-MBC (R2 = 0.957**, P < 0.01). The 14C-DOC and 14C-MBC as proportions of total DOC, MBC, were 5.65%-24.91% and 4.23%-20.02%, respectively. Moreover, the distribution and transformation of microbes-assimilated-derived C had a greater influence on the dynamics of DOC and MBC than that on the dynamics of SOC. These data provide new insights into the importance of microorganisms in the fixation of atmospheric CO2 and of the potentially significant contributions made by microbial autotrophy to terrestrial C cycling.

  14. Syntheses of [sup 14]C-ochratoxin A and [sup 14]C-ochratoxin B and a comparative study of their distribution in rats using whole body autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Breitholtz-Emanuelsson, A.; Hult, K. (Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm (Sweden)); Fuchs, R. (Department of Toxicology, Institute for Medical Research and Occupational Health, University of Zagreb, Zagreb (Yugoslavia)); Appelgren, L.-E. (Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    1992-01-01

    Methods for preparation of labelled ochratoxin A and B are described. The method for preparation of labelled ochratoxin B involves the synthesis of the azide of ochratoxin [beta] via the mixed anhydride and subsequent conjugation to labelled phenylalanine to yield [sup 14]C-ochratoxin B. The labelled ochratoxins were injected into male Wistar rats and after different survival times they were sacrificed and subjected to whole body autoradiography. The distribution pattern of ochratoxin A in the rat did not differ from that earlier registered for mouse. The previously known, high susceptibility of rats (and not mice) to ochratoxin A-induced cancer could thus not be explained by an accumulation of the toxin in specific cells or organs. The distribution patterns of ochratoxin A and B were almost congruent - the only apparent difference being a much longer retention of the labelled ochratoxin A in the blood compared to ochratoxin B, which was much faster excreted. When analyzing tissue extract for labelled metabolites only the extracts from the rats injected with ochratoxin B were found to contain easily detectable concentrations, while no metabolites of ochratoxin A were seen. (au).

  15. Towards a global understanding of vertical soil carbon dynamics: meta-analysis of soil 14C data

    Science.gov (United States)

    hatte, C.; Balesdent, J.; Guiot, J.

    2012-12-01

    Soil represents the largest terrestrial storage mechanism for atmospheric carbon from photosynthesis, with estimates ranging from 1600 Pg C within the top 1 meter to 2350 Pg C for the top 3 meters. These values are at least 2.5 times greater than atmospheric C pools. Small changes in soil organic carbon storage could result in feedback to atmospheric CO2 and the sensitivity of soil organic matter to changes in temperature, and precipitation remains a critical area of research with respect to the global carbon cycle. As an intermediate storage mechanism for organic material through time, the vertical profile of carbon generally shows an age continuum with depth. Radiocarbon provides critical information for understanding carbon exchanges between soils and atmosphere, and within soil layers. Natural and "bomb" radiocarbon has been used to demonstrate the importance and nature of the soil carbon response to climatic and human impacts on decadal to millennial timescales. Radiocarbon signatures of bulk, or chemically or physically fractionated soil, or even of specific organic compounds, offer one of the only ways to infer terrestrial carbon turnover times or test ecosystem carbon models. We compiled data from the literature on radiocarbon distribution on soil profiles and characterized each study according to the following categories: soil type, analyzed organic fraction, location (latitude, longitude, elevation), climate (temperature, precipitation), land use and sampling year. Based on the compiled data, soil carbon 14C profiles were reconstructed for each of the 226 sites. We report here partial results obtained by statistical analyses of portion of this database, i.e. bulk and bulk-like organic matter and sampling year posterior to 1980. We highlight here 14C vertical pattern in relationship with external parameters (climate, location and land use).

  16. Continuous lake-sediment records of glaciation in the Sierra Nevada between 52,600 and 12,500 14C yr B.P.

    Science.gov (United States)

    Benson, L.V.; May, Howard M.; Antweiler, R.C.; Brinton, T.I.; Kashgarian, Michaele; Smoot, J.P.; Lund, S.P.

    1998-01-01

    The chemistry of the carbonate-free clay-size fraction of Owens Lake sediments supports the use of total organic carbon and magnetic susceptibility as indicators of stadial-interstadial oscillations. Owens Lake records of total organic carbon, magnetic susceptibility, and chemical composition of the carbonate-free, clay-size fraction indicate that Tioga glaciation began ~24,500 and ended by ~13,600 14C yr B.P. Many of the components of glacial rock flour (e.g., TiO2, MnO, BaO) found in Owens Lake sediments achieved maximum values during the Tioga glaciation when valley glaciers reached their greatest extent. Total organic carbon and SiO2 (amorphous) concentrations reached minimum values during Tioga glaciation, resulting from decreases in productivity that accompanied the introduction of rock flour into the surface waters of Owens Lake. At least 20 stadial-interstadial oscillations occurred in the Sierra Nevada between 52,600 and 14,000 14C yr B.P. Total organic carbon data from a Pyramid Lake sediment core also indicate oscillations in glacier activity between >39,500 and ~13,600 14C yr B.P. Alpine glacier oscillations occurred on a frequency of ???1900 yr in both basins, suggesting that millennial-scale oscillations occurred in California and Nevada during most of the past 52,600 yr.

  17. Pediatric Microdose Study of [14C]Paracetamol to Study Drug Metabolism Using Accelerated Mass Spectrometry: Proof of Concept

    NARCIS (Netherlands)

    M.G. Mooij (Miriam); E. van Duijn (Esther); C.A.J. Knibbe (Catherijne); A.D. Windhorst (Albert); N.H. Hendrikse (N. Harry); W.H.J. Vaes (Wouter H. J.); E. Spaans (Edwin); B.O. Fabriek (Babs); H. Sandman (Hugo); D. Grossouw (Dimitri); L.M. Hanff (Lidwien); P.J.J.M. Janssen (Paul); B.C.P. Koch (Birgit C. P.); D. Tibboel (Dick); S.N. de Wildt (Saskia)

    2014-01-01

    textabstractResults: Ten infants (aged 0.1–83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [14C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (Cmax) [14C]AAP 1.68

  18. Pediatric Microdose Study of [14C]Paracetamol to Study Drug Metabolism Using Accelerated Mass Spectrometry: Proof of Concept

    NARCIS (Netherlands)

    Mooij, M.G.; Duijn, E. van; Knibbe, C.A.J.; Windhorst, A.D.; Hendrikse, N.H.; Vaes, W.H.J.; Spaans, E.; Fabriek, B.O.; Sandman, H.; Grossouw, D.; Hanff, L.M.; Janssen, P.J.J.M.; Koch, B.C.P.; Tibboel, D.; de Wildt, S.N.

    2014-01-01

    Results: Ten infants (aged 0.1–83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [14C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (Cmax) [14C]AAP 1.68 (0.75–4.76) ng/L,

  19. Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

    NARCIS (Netherlands)

    Garner, C.R.; Park, K.B.; French, N.S.; Earnshaw, C.; Schipani, A.; Selby, A.M.; Byrne, L.; Siner, S.; Crawley, F.P.; Vaes, W.H.J.; Duijn, E. van; ligt, R. de; Varendi, H.; Lass, J.; Grynkiewicz, G.; Maruszak, W.; Turner, M.A.

    2015-01-01

    Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group. Meth

  20. Measurement of depth distributions of (3)H and (14)C induced in concrete shielding of an electron accelerator facility.

    Science.gov (United States)

    Endo, Akira; Harada, Yasunori; Kawasaki, Katsuya; Kikuchi, Masamitsu

    2004-06-01

    The estimation of radioactivity induced in concrete shielding is important for the decommissioning of accelerator facilities. Concentrations of (3)H and (14)C in the concrete shielding of an electron linear accelerator were measured, and the depth distributions of (3)H and (14)C and gamma-ray emitters were discussed in relation to their formation reactions.

  1. Pediatric Microdose Study of [14C]Paracetamol to Study Drug Metabolism Using Accelerated Mass Spectrometry: Proof of Concept

    NARCIS (Netherlands)

    Mooij, M.G.; Duijn, E. van; Knibbe, C.A.J.; Windhorst, A.D.; Hendrikse, N.H.; Vaes, W.H.J.; Spaans, E.; Fabriek, B.O.; Sandman, H.; Grossouw, D.; Hanff, L.M.; Janssen, P.J.J.M.; Koch, B.C.P.; Tibboel, D.; de Wildt, S.N.

    2014-01-01

    Results: Ten infants (aged 0.1–83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [14C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (Cmax) [14C]AAP 1.68 (0.75–4.76) ng/L,

  2. Pediatric Microdose Study of [14C]Paracetamol to Study Drug Metabolism Using Accelerated Mass Spectrometry: Proof of Concept

    NARCIS (Netherlands)

    M.G. Mooij (Miriam); E. van Duijn (Esther); C.A.J. Knibbe (Catherijne); A.D. Windhorst (Albert); N.H. Hendrikse (N. Harry); W.H.J. Vaes (Wouter H. J.); E. Spaans (Edwin); B.O. Fabriek (Babs); H. Sandman (Hugo); D. Grossouw (Dimitri); L.M. Hanff (Lidwien); P.J.J.M. Janssen (Paul); B.C.P. Koch (Birgit C. P.); D. Tibboel (Dick); S.N. de Wildt (Saskia)

    2014-01-01

    textabstractResults: Ten infants (aged 0.1–83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [14C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (Cmax) [14C]AAP 1.68 (0.75–

  3. Operation of the Harwell UK 14C Data Base and its Expansion through Data Exchange with Other Laboratories

    NARCIS (Netherlands)

    Walker, A.J.; Otlet, R.L.; Housley, R.A.; Plicht, Johannes van der

    1990-01-01

    The use of computer data bases for storage and retrieval of 14C data is a logical application for the rapidly expanding numbers of 14C determinations. Harwell has established a data base for all samples originating from sites in the United Kingdom and Eire. The core of the data is the Council for

  4. Human systemic exposure to [14C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment

    NARCIS (Netherlands)

    Nohynek, G.J.; Skare, J.A.; Meuling, W.J.A.; Wehmeyer, K.R.; Bie, A.T.H.J. de; Vaes, W.H.J.; Dufour, E.K.; Fautz, R.; Steiling, W.; Bramante, M.; Toutain, H.

    2015-01-01

    Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [14C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [14C] was measured in all

  5. Proton production cross sections of {sup 14}C from silicon and oxygen: Implications for cosmic-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, J.M. [Harvard Univ., Cambridge, MA (United States). Cyclotron Lab.; Jull, A.J.T. [Arizona Univ., Tucson, AZ (United States). NSF Arizona Accelerator Mass Spectrometer Facility; Beverding, A. [San Jose State Univ., CA (United States). Dept. of Chemistry] [and others

    1993-12-31

    The production rates of {sup 14}C from proton spallation of silicon, and oxygen have been measured over a wide range of energies from 31 to 450 MeV. {sup 14}C was measured by accelerator mass spectrometry (AMS) after extraction of carbon from the samples by melting in a flow of oxygen.

  6. Uncertainty in 14C model ages of groundwater: The influence of soil gas in terranes dominated by C3 plants

    Science.gov (United States)

    Nelson, S.; Hart, R.; Eggett, D.

    2009-12-01

    Groundwater is the largest source of fresh water readily available to humanity and aquifers with long residence times are particularly susceptible to overuse. Thus, it is important to have quantitative estimates of the residence time of water in such aquifers. Many models used to calculate 14C ages of groundwater depend on an estimate of the δ13C value of carbon dioxide in soil at the time of recharge, a value that must be estimated. Other work has suggested that for terranes dominated by C3 plants, -23‰ is an appropriate value, and sensitivity calculations show that the apparent age of a groundwater is strongly dependent on the choice of this parameter. This is especially true where the measured values of δ13C of dissolved inorganic carbon (DIC) are used to estimate the contribution of “dead” carbon to the DIC load via the dissolution of calcite in the aquifer and soil zones. To better understand the temporal and spatial isotopic and abundance variability of soil carbon dioxide, we established soil gas sampling sites that encompassed a wide variety of settings in terms of season, elevation, climate, and plant community that were sampled monthly throughout regions of the state of Utah where C3 flora dominate. Direct measurements of soil gas suggest a value of -21.8 ± 1.4‰ (1σ) is a good input variable as long as: a) C3 vegetation dominates, and b) extreme aridity does not prevail such that plant densities and soil microbial activities are minimized. If recharge is envisaged to occur during spring and early summer in highly vegetated uplands, a value of -24.0 ± 0.6‰ may be more appropriate as statistical analysis reveals that seasonality and plant density are most clearly correlated to the carbon isotope composition of carbon dioxide in soil gas. Although the two values and ranges cited above values do not diverge strongly from other published estimates, they place fairly narrow limits on the uncertainty of ±500 and ±200 yr., respectively, in

  7. Investigation of the association between glaucoma and Helicobacter pylori infection using the {sup 14}C-urea breath test

    Energy Technology Data Exchange (ETDEWEB)

    Tuzcu, Esra Ayhan; Aydogan, Fusun; Motor, Vicdan Koksaldi; Ilhan, Ozgur; Daglioglu, Mutlu Cihan; Coskun, Mesut; Parlakfikirer, Nihan; Keskin, Ugurcan, E-mail: drayhant@hotmail.com [Medical Faculty, Mustafa Kemal University, Hatay (Turkey)

    2015-07-01

    Purpose: to investigate the association between glaucoma and Helicobacter pylori infection by evaluating for the presence of H. pylori infection in patients with glaucoma using the 14C-urea breath test (14C-UBT). Methods: Using 14C-UBT, H. pylori infection positivity was compared between a group of patients with primary open-angle glaucoma and a control group with normal intraocular pressure and a normal optic disc or normal perimetry. Results: the 14C-UBT was positive in 18 (51.42%) out of 35 patients in the glaucoma group and in 15 (42.85%) out of 35 patients in the control group. H. pylori infection positivity rates were similar between the glaucoma and control groups (p>0.05). Conclusion: according to the 14C-UBT, there is no association between primary open-angle glaucoma and H. pylori infection. (author)

  8. Distribution and elimination of 4-/sup 14/C-mofebutazone in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Graul, E.H.; Loew, D.; Schuster, O.

    1986-08-01

    Orally administered /sup 14/C mofebutazone is absorbed quickly and within 24 hours almost completely excreated - 80.5% in urine and 1.2% in the feces. Similar results have also been reported by BASS et al. Distribution results mainly over the organs of metabolisation and elimination. Apart from the gastrointestinal tract very high concentrations were found in the liver and kidneys after 45 minutes, but these concentrations diminished very distinctly after 6 hours and after 24 hours radioactivity was only detectable in the feces of the large intestine. /sup 14/C mofebutazone cannot be detected in lipophilic tissues such as fatty tissues, brain and spinal marrow at any of the points of time investigated. The bone marrow is also free of radioactivity to a great extent. However, under the skin and in the muscular tissue there is distinct radioactivity of /sup 14/C mofebutazone. On the other hand BRUNE was able to show that phenylbutazone was detectable in the bone marrow as well as in the organs of metabolisation and elimination. Further differences between mofebutazone and phenylbutazone should be shown by means of these investigations. Therefore, global statements and conclusions on the effect, mechanisms of effect and side effects of substances from a category of chemical substances are not justified in the case of non-steroidal antirheumatics. Slight chemical modifications often lead to other effects and side effects. With mofebutazone as an example it is shown that in spite of chemical similarity to phenylbutazone both substances are distinctly different with regard to toxicological, pharmacological, pharmacokinetic and chemical-physical aspects.

  9. Longevity and growth of Acacia tortilis; insights from 14C content and anatomy of wood

    Directory of Open Access Journals (Sweden)

    Krzywinski Knut

    2007-06-01

    Full Text Available Abstract Background Acacia tortilis is a keystone species across arid ecosystems in Africa and the Middle East. Yet, its life-history, longevity and growth are poorly known, and consequently ongoing changes in tree populations cannot be managed in an appropriate manner. In other arid areas parenchymatic bands marking growth zones in the wood have made dendrochronological studies possible. The possibilities for using pre- and post-bomb 14C content in wood samples along with the presence of narrow marginal parenchymatic bands in the wood is therefore tested to gain further insight into the age, growth and growth conditions of A. tortilis in the hyper-arid Eastern Desert of Egypt. Results Based on age scenarios and the Gompertz growth equation, the age of trees studied seems to be from 200 up to 650 years. Annual radial growth estimated from calibrated dates based on the post-bomb 14C content of samples is up to 2.4 mm, but varies both spatially and temporally. Parenchymatic bands are not formed regularly. The correlation in band pattern among trees is poor, both among and within sites. Conclusion The post-bomb 14C content of A. tortilis wood gives valuable information on tree growth and is required to assess the age scenario approach applied here. This approach indicates high longevities and slow growth of trees. Special management measures should therefore be taken at sites where the trend in tree population size is negative. The possibilities for dendrochronological studies based on A. tortilis from the Eastern Desert are poor. However, marginal parenchymatic bands can give insight into fine scale variation in growth conditions and the past management of trees.

  10. Accelerated degradation of 14C-atrazine in an atrazine adapted field soil from Belgium

    Science.gov (United States)

    Hamacher, Georg; Jablonowski, Nicolai David; Martinazzo, Rosane; Accinelli, Cesare; Köppchen, Stephan; Langen, Ulrike; Linden, Andreas; Krause, Martina; Burauel, Peter

    2010-05-01

    Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is one of the most widely used herbicides in the world. Atrazine is considered to be mobile in soil and has often been characterized as a rather recalcitrant compound in the environment. In the present study the accelerated atrazine degradation in an agriculturally used soil was examined. Soil samples were collected from a Belgian field which was used for corn-plantations and was regularly treated with atrazine during the last 30 years. The experiment was conducted under controlled laboratory conditions (GLP) using 14C-labelled and unlabelled atrazine in accordance to the reported field application dose of 1 mg kg-1. Triplicates of treated subsamples were incubated at 50% WHCmax and under slurry conditions (1:4 soil:solution ratio, using distilled water) in the dark at 20° C. Control samples were collected at an adjacent pear orchard where no atrazine or other triazine pesticides application was reported. After 92 days of incubation, the mineralized amount of atrazine reached 83% of the initially applied 14C-activity in the atrazine treated soil for the slurry setup. A maximum of atrazine mineralization was observed in the treated field soil between 6 and 7 days of incubation for both, 50% WHCmax and slurry setups. The total 14C-atrazine mineralization was equally high for 50% WHCmax in the atrazine treated soil. After an extended lag-phase in comparison to the treated soil the overall mineralization of 14C-atrazine of 81% was observed in the atrazine untreated soil under slurry conditions. This observation might be due to a possible cross adaption of the microflora. These results could be attributed to an atrazine drift during application since the control samples were taken in an adjacent pear orchard with no atrazine application history. These results demonstrate an adaption of the microflora to mineralize atrazine rapidly. The formation of desorbable metabolites as well as the formation of

  11. Synthesis of /sup 14/C-labeled perfluorooctanoic and perfluorodecanoic acids: purification of perfluorodecanoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Reich, I.L.; Reich, H.J.; Menahan, L.A.; Peterson, R.E.

    1987-10-01

    Perfluoro-n-octanoic acid (PFOA) and perfluoro-n-decanoic acid (PFDA), two widely used industrial products, have been synthesized with /sup 14/C-labeling in the C-1 position. The carboxyl labeled materials were prepared in 48% and 53% yield by carbonation of perfluoroheptyllithium and perfluorononyllithium at -100/sup 0/C. An efficient chemical method for purification of PFDA was also developed. Treatment of commercial PFDA with refluxing potassium hydroxide solution resulted in removal of the mono and diprotio impurities to give 99% pure PFDA.

  12. Binding of mescaline with subcellular fractions upon incubation of brain cortex slices with [14C] mescaline.

    Science.gov (United States)

    Datta, R K; Antopol, W; Ghosh, J J

    1977-01-01

    Incubation of brain cortex slices in the presence of glucose resulted in the permeation of about 65% of [14C] mescaline into slices. Of this, about one-third radioactivity was bound with nuclei, mitochondria, microsomes, and ribosomes. Dialysis of subcellular fractions did not markedly reduce the amounts of radioactivity bound to the fractions. The permeation into slices and the binding of mescaline to subcellular fractions were fairly time-dependent, but were inhibited by the presence of potassium cyanide, or by the absence of glucose and by heating to 80 degrees C for 1 min.

  13. Mikrobieller Abbau von 14 C-markiertem Benzo[a]pyren durch PAK-adaptierte Bakterienmischkulturen

    OpenAIRE

    Schwiening, Susanne

    2000-01-01

    In the last years the biodegradation of polycylic aromatic hydrocarbons (PAH) for the bioremediation of polluted soils was studied. Important for a successfull remediation is the degradation of the high molecular weight PAH, a major class of carcinogenic and persistent organic compounds. So the aim of this work was to study the biodegradation of the 5-ring benzo[a]pyrene (BaP) as a priority pollutant of the high molecular weight PAH. With the use of 14C labeled BaP the degradation could be qu...

  14. Process behavior and environmental assessment of /sup 14/C releases from an HTGR fuel reprocessing facility

    Energy Technology Data Exchange (ETDEWEB)

    Snider, J.W.; Kaye, S.V.

    1976-01-01

    Large quantities of /sup 14/CO/sub 2/ will be evolved when graphite fuel blocks are burned during reprocessing of spent fuel from HTGR reactors. The possible release of some or all of this /sup 14/C to the environment is a matter of concern which is investigated in this paper. Various alternatives are considered in this study for decontaminating and releasing the process off-gas to the environment. Concomitant radiological analyses have been done for the waste process scenarios to supply the necessary feedbacks for process design.

  15. Magmatic CO2 emissions at Mammoth Mountain, California, tracked by 14C in tree core

    Science.gov (United States)

    Evans, B.; Mangan, M.; McGeehin, J. P.; King, J.; Lewicki, J. L.; Hilley, G. E.

    2011-12-01

    Magmatic CO2 efflux to the atmosphere causes persistent depletion of 14C in the wood of trees that grow in areas of strong emissions. The record of 14C depletion in core from a surviving tree at the Horseshoe Lake tree-kill area, on the S flank of Mammoth Mountain volcano, has been updated to cover the time period 1984 to 2010. The amount of depletion was reasonably stable in annual growth rings for years 1995-2009 and indicates that the magmatic CO2 component in air at canopy height was 31±7 ppmv. Depletion increased sharply in the 2010 ring, yielding a magmatic CO2 concentration of 56 ppmv. This observation is consistent with accumulation chamber and eddy covariance measurements from the area, which indicate that magmatic CO2 effluxes and near-surface atmospheric concentrations increased during 2010. The agreement between tree-core and direct gas measurements suggests that the selected tree may be suitable for constraining the long-term record of CO2 emission strength at Horseshoe Lake, but the ability of a single tree to constrain total CO2 discharge from a broad region of diffuse emissions needs investigation. New concentration source-area modeling based on local atmospheric data measured by a 3-m tall eddy covariance tower suggests that the 13-m tall tree cored may provide a weighted integration of CO2 emission strength over an area at least as large as the Horseshoe Lake gas anomaly (0.3 km2). If the tree-core record accurately reflects total CO2 discharge, then emission strength in 2010 approached that in 1990, when anomalous gas efflux began in the aftermath of a 6-month seismic swarm linked to upflow of magmatic fluids. The apparent increase in emission strength in 2010 may correlate with a recent resurgence in seismicity beneath Mammoth Mountain and an increase in the 3He/4He ratio in fumarolic emissions near the summit, both of which began in 2009. If so, a correlative increase in 14C depletion is likely to exist in trees at other areas around the

  16. Absorption, Distribution, Metabolism, and Excretion of 14C-RDX Following Oral Administration to Minipigs

    Science.gov (United States)

    2010-08-02

    RDX. On the day of dosing, 30.086 mg of 14C-RDX and 4,218.6 mg of RDX were combined with 450 mL of 0.5% carboxymethylcellulose in water. The dose...switching valve. Negative Ion LC/MS/MS Analyses Selective multiple reaction monitoring (MRM) was used as survey scan to activate product ion scans...MS2) through preset information dependent acquisition (IDA) criteria. Q1 full scan, precursor scan (prec) of specific product ions at m/z 61 and 46

  17. Impact of bacterial and fungal processes on {sup 14}C-hexadecane mineralisation in weathered hydrocarbon contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Adetutu, Eric M.; Ball, Andy S. [School of Biological Sciences, Flinders University, Adelaide, South Australia, 5001 (Australia); Weber, John; Aleer, Samuel; Dandie, Catherine E. [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Adelaide, South Australia, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, Adelaide, South Australia, 5095 (Australia); Juhasz, Albert L., E-mail: Albert.Juhasz@unisa.edu.au [Centre for Environmental Risk Assessment and Remediation (CERAR), University of South Australia, Mawson Lakes Campus, Adelaide, South Australia, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Mawson Lakes, Adelaide, South Australia, 5095 (Australia)

    2012-01-01

    In this study, the impact of bacterial and fungal processes on {sup 14}C-hexadecane mineralisation was investigated in weathered hydrocarbon contaminated soil. The extent of {sup 14}C-hexadecane mineralisation varied depending on the bioremediation strategy employed. Under enhanced natural attenuation conditions, {sup 14}C-hexadecane mineralisation after 98 days was 8.5 {+-} 3.7% compared to < 1.2% without nitrogen and phosphorus additions. {sup 14}C-hexadecane mineralisation was further enhanced through Tween 80 amendments (28.9 {+-} 2.4%) which also promoted the growth of a Phanerochaete chyrsosporium fungal mat. Although fungal growth in weathered hydrocarbon contaminated soil could be promoted through supplementing additional carbon sources (Tween 80, sawdust, compost, pea straw), fungal {sup 14}C-hexadecane mineralisation was negligible when sodium azide was added to soil microcosms to inhibit bacterial activity. In contrast, when fungal activity was inhibited through nystatin additions, {sup 14}C-hexadecane mineralisation ranged from 6.5 {+-} 0.2 to 35.8 {+-} 3.8% after 98 days depending on the supplied amendment. Bacteria inhibition with sodium azide resulted in a reduction in bacterial diversity (33-37%) compared to microcosms supplemented with nystatin or microcosms without inhibitory supplements. However, alkB bacterial groups were undetected in sodium azide supplemented microcosms, highlighting the important role of this bacterial group in {sup 14}C-hexadecane mineralisation. - Highlights: Black-Right-Pointing-Pointer The roles of different microbial groups in hydrocarbon mineralisation was assessed. Black-Right-Pointing-Pointer Inhibiting fungal growth did not affect {sup 14}C-hexadecane mineralisation. Black-Right-Pointing-Pointer Inhibiting bacterial growth resulted in negligible {sup 14}C-hexadecane mineralisation. Black-Right-Pointing-Pointer alkB bacterial groups were undetected in sodium azide supplemented microcosms. Black

  18. Syntheses of {gamma}-aminobutyric-1-{sup 14}C and of {alpha}-aminoadipic-6-{sup 14}C acid from methoxy-3 chloropropyl-magnesium and marked carbon dioxide; Syntheses de l'acide {gamma}-aminobutyrique{sup 14}C-1 et de l'acide {alpha}-aminoadipique {sup 14}C-6 a partir de methoxy-3 chloropropylmagnesium et d'anhydride carbonique marque

    Energy Technology Data Exchange (ETDEWEB)

    Phung Nhu Liem [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement des radioelements, Service des molecules marquees

    1967-04-01

    Carbonation of {gamma}-methoxypropyl-magnesium chloride by CO{sub 2} gives {gamma}-methoxy-butyric carboxylic-{sup 14}C acid with a yield of about 95 per cent. When the latter is treated successively with anhydrous HBr and with diazomethane, methyl carboxylic {gamma}-bromobutyrate-{sup 14}C is formed. This in turn gives {gamma}-amino-butyric carboxylic-{sup 14}C acid with an overall yield of 66 per cent with respect to Ba{sup 14}CO{sub 3}, when it is condensed with potassium phthalimide and hydrolyzed by acid. By reacting methyl-{gamma}-bromobutyrate-{sup 14}C with the sodium derivative of ethyl cyanacetamido-acetate in ethanol, followed by an acid hydrolysis, {alpha}-aminoadipic-6-{sup 14}C acid is obtained with an overall yield of 46 per cent with respect to Ba{sup 14}CO{sub 3}. (author) [French] La carbonatation du chlorure de {gamma}-methoxypropylmagnesium par {sup 14}CO{sub 2} donne l'acide {gamma}-methoxybutyrique carboxyle {sup 14}C avec un rendement d'environ 95 pour cent. Ce dernier traite successivement par HBr anhydre et par le diazomethane conduit au {gamma}-bromobutyrate de methyle carboxyle {sup 14}C. Celui-ci condense avec le phtalimide de potassium suivi d'une hydrolyse acide fournit l'acide {gamma}-aminobutyrique carboxyle {sup 14}C avec un rendement global de 66 pour cent par rapport a Ba{sup 14}CO{sub 3}. L'action du {gamma}-bromobutyrate de methyle {sup 14}C sur le derive sode du cyanacetamidoacetate d'ethyle dans l'ethanol suivie d'hydrolyse acide donne l'acide {alpha}-aminoadipique {sup 14}C-6 avec un rendement global de 46 pour cent par rapport a Ba{sup 14}CO{sub 3}. (auteur)

  19. Estimation of enthalpy data for reactions involving gas phase ions utilizing lattice potential energies: fluoride ion affinities (FIA) and pF- values of mSbF5(l) and mSbF5(g) (m = 1, 2, 3), AsF5(g), AsF5.SO2(c). Standard enthalpies of formation: Delta(f)H degrees (SbmF5m+1)(-),g) (m = 1, 2, 3), Delta(f)H degrees (AsF6(-),g), and Delta(f)H degrees (NF4+,g).

    Science.gov (United States)

    Jenkins, H Donald Brooke; Roobottom, H K; Passmore, Jack

    2003-05-01

    Fluoride ion affinity (FIA) values (and the associated pF(-) values) are difficult to establish experimentally for pentafluorides of arsenic and antimony. Our approach, utilizing estimated lattice potential energies, provides a further opportunity to establish this data for liquid (and gaseous) SbF(5) and gaseous AsF(5) which compliments values obtained using ab initio routes for monomeric gas phase molecules and adds to results based on rigorous methods. A strategy is developed whereby construction of (multiple) Born-Fajans-Haber cycles centered around the (target) FIA reaction of interest yield a plethora of estimates for the enthalpy change of interest. This general approach is illustrated here by specific estimation of some experimentally based FIA values of SbF(5) and AsF(5). FIA values/kJ mol(-1) and pF- values estimated in this paper are FIA(SbF(5),l) approximately equal to -475 (+/-63), pF-(SbF(5),l) = 11.4 (+/-1.5); FIA(SbF(5),g) approximately equal to -506 (+/-63), pF-(SbF(5),g) = 12.4 (+/-1.5); FIA(2SbF(5),l) approximately equal to -609 (+/-63), pF- (2SbF(5),l) = 14.6 (+/-1.5); FIA (2SbF(5),g) approximately equal to -671 (+/-63), pF- (2SbF(5),g) = 16.0 (+/-1.5); FIA (3SbF(5),l) approximately -635 (+/-39), pF(-) (3SbF(5),l) = 15.2 (+/-0.9); FIA(3SbF(5),g) approximately -728 (+/-39), pF(-) (3SbF(5),g) = 17.4 (+/-0.9); FIA(AsF(5),g) approximately equal to -421 (+/-22), pF(-) (AsF(5),g) = 10.1 (+/- 0.5); and FIA (AsF(5).SO(2),s) approximately equal to -390 (+/-22), pF(-) (AsF(5).SO(2),s) = 9.3 (+/-0.5). Related standard enthalpies of formation (in kJ mol(-1)) are also assigned: Delta(f)H degrees (SbF(6)(-),g) approximately equal to -2075 (+/-52); Delta(f)H degrees (Sb(2)F(11)(-),g) approximately equal to -3520 (+/-63); Delta(f)H degrees (Sb(3)F(16)(-),g) approximately equal to -4874 (+/-39); Delta(f)H degrees (NF(4)(+),g) approximately equal to 903 (+/-32); Delta(f)H degrees (AsF(6)(-),g) approximately equal to -1907 (+/-22).

  20. Gas chromatograph-combustion system for 14C-accelerator mass spectrometry.

    Science.gov (United States)

    McIntyre, Cameron P; Sylva, Sean P; Roberts, Mark L

    2009-08-01

    A gas chromatograph-combustion (GC-C) system is described for the introduction of samples as CO(2) gas into a (14)C accelerator mass spectrometry (AMS) system with a microwave-plasma gas ion source. Samples are injected into a gas chromatograph fitted with a megabore capillary column that uses H(2) as the carrier gas. The gas stream from the outlet of the column is mixed with O(2) and Ar gas and passed through a combustion furnace where the H(2) carrier gas and separated components are quantitatively oxidized to CO(2) and H(2)O. Water vapor is removed using a heated nafion dryer. The Ar carries the CO(2) to the ion source. The system is able to separate and oxidize up to 10 microg of compound and transfer the products from 7.6 mL/min of H(2) carrier gas into 0.2-1.0 mL/min of Ar carrier gas. Chromatographic performance and isotopic fidelity satisfy the requirements of the (14)C-AMS system for natural abundance measurements. The system is a significant technical advance for GC-AMS and may be capable of providing an increase in sensitivity for other analytical systems such as an isotope-ratio-monitoring GC/MS.

  1. {sup 14}C dating of early Neolithic settlement Galovo near Slavonski Brod in Northern Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Krajcar Bronic, I. [Rudjer Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia)], E-mail: krajcar@irb.hr; Minichreiter, K. [Institute of Archaeology, Ul. grada Vukovara 68, 10000 Zagreb (Croatia)

    2007-09-21

    In Northern Croatia, more than hundred settlements are known from the period of the Starcevo culture, the first Neolithic period in south-east (SE) Europe. Here we present the {sup 14}C dating of nine charcoal samples from the Neolithic settlement Galovo in Slavonski Brod. According to archaeological findings, it belongs to the early phase (Linear A) of the Starcevo culture and has a special ritual-burial area separated by two wooden fences from its residential part. The vertical stratigraphy revealed two phases of the settlement construction in period 6070-5630 cal BC. In the younger phase (5380-4960 cal BC) the settlement expanded and the burial area became smaller. Combination of archaeological findings and {sup 14}C dates thus allowed a reconstruction of the 1000-year-long existence of this settlement that existed simultaneously with the nearby settlement Zadubravlje-Duzine, dated earlier to 6000-5000 cal BC. These are the first absolute dates of the beginning of neolithization in Northern Croatia.

  2. The disposition of /sup 14/C-trimethyltin in the pregnant rat and fetus

    Energy Technology Data Exchange (ETDEWEB)

    Lipscomb, J.C.; Paule, M.G.; Slikker, W. Jr.

    1989-03-01

    Trimethyltin (TMT) is a potent neurotoxicant. For unknown reasons, age at exposure to TMT may dramatically influence the severity of TMT-induced neuropathology. We have demonstrated previously that radiolabel derived from (/sup 14/C)-TMT given to pregnant dams on gestational day (GD) 17 is found in fetal brain and blood. The present study was designed to determine the distribution of radiolabel derived from (14C)-TMT to brain and other tissue in fetuses from dams dosed on either GD 12 or 17 with 7.0 mg/kg TMT chloride. Radioactivity in GD 12 and GD 17 maternal whole blood peaked 1 hour after IP treatment. Whole blood elimination half-lives were 12-15 days. Peak radiolabel concentrations in GD 12 maternal and fetal brain were only 11-30% of those from GD 17 animals, however, peak fetal brain concentrations of radiolabel were not different from their respective maternal brain concentrations. Radiolabel concentrations in liver, kidney, and adrenal of GD 17 dams were higher than those in corresponding GD 12 tissues. Combined urinary and fecal elimination of radiolabel for two weeks after dosing accounted for 31 and 22% of the GD 12 and 17 doses, respectively. It appears that gestational age influences the distribution and elimination of TMT in the rat.

  3. Liming effect in the degradation of 14C-glyphosate in soils

    Energy Technology Data Exchange (ETDEWEB)

    Arantes, Sayonara A.C.M.; Lavorenti, Arquimedes [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mails: samoreno@esalq.usp.br; alavoren@esalq.usp.br; Tornisielo, Valdemar L. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: vltornis@cena.usp.br

    2007-07-01

    Liming is soil fertility management practice essential in tropical soils, in general extremely acidic. This practice, by influencing physical, chemical and biological features of soils may influence the behavior of organic molecules in soils. The glyphosate is one the most widely used pesticides in Brazil in several cultures to pest management control. Studies on its fate in soil are still incipient, mainly under the effect of liming practice The objective of the present study was to verify the effect of liming practice in the degradation of glyphosate in Red Latosol (LE) and Quartzarenic Neosol (RQ) soils and also in the microbial activity of the same soils. The experiment was conducted in a completely randomized design in a 2 x 2 factorial scheme, corresponding to two soils and two management conditions (with liming and without liming), with four replicates. The Radiometric technique was utilized to evaluate the evolution the {sup 14}CO{sub 2} at intervals of 7 days, during 70 days. The study of microbial activity was conducted parallel to the degradation experiment, using the methodology of radiolabelled glucose ({sup 14}C-glucose), which was measured at intervals of fourteen days, during 70 days. The results showed that in the studied soils, the liming increased the {sup 14}C-glyphosate mineralization and the microbial activity. (author)

  4. RELATIVE EXPRESSION OF GENES CHIA1, SGF14C AND CHS8* IN SOYBEAN SEED COATS

    Directory of Open Access Journals (Sweden)

    CARLOS ANDRÉ BAHRY

    2014-01-01

    Full Text Available The aim of this study was to evaluate the relative expression of three candidate genes, CHIA1, SGF14c and CHS8 * possibly involved in seed quality, in contrasting seed coats from four soybean genotypes. Two genotypes with yellow seed coats, BMX Potência RR and CD 202, and two genotypes with black seed coats, TP and IAC were studied to determine the relative gene expression through the qPCR technique, in sev- en stages of seed coat development for all four genotypes, at 25, 30, 35, 40, 45, 50 and 55 days after anthesis. The CHIA1 and SGF14c genes showed higher expression in cultivar CD 202; the former in the final stages of seed coat development, at 55 days after anthesis, the latter gene at earlier stages, specifically at 25 days after anthesis. The CHS8* gene showed higher expression in CD 202 seed coats at 50 days after anthesis. All three genes expressed at higher levels on genotypes of yellow seed coats, and are considered relevant to new areas of research based on the expression of genes related to seed quality.

  5. Highly Sensitive 14C and 3H Quantification of Biochemical Samples Using Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, T J; Vogel, J S

    2003-10-23

    Accelerator Mass Spectrometry (AMS) is an isotope ratio mass spectrometer that quantifies low levels of rare isotopes with half-lives between 10 and 10{sup 8} years. Typical sensitivities are 10{sup 6} atoms in a milligram-sized sample. AMS was originally developed for use in the geosciences as a tool to carbon date archaeological artifacts, but has applications in many fields. In the biosciences, the extreme sensitivity of AMS is used to trace nutrients, toxins and therapeutics in humans and animals using less than {micro}g/kg doses containing between 1-100 nCi of {sup 14}C. This sensitivity is used to reduce sample size, reduce chemical exposures to environmental or physiological levels, reduce radiation exposures to subjects, and/or reduce radioactive (and ''mixed'') waste. Compared to decay counting, AMS provides for a much higher measurement throughput for low activity samples. For example, a milligram-sized sample containing 1 dpm of {sup 14}C can be measured to 3% precision in several seconds. That same sample would require approximately 1 week of decay counting to obtain similar precision.

  6. Synthesis of organic substances labelled with {sup 14}C and {sup 35}S; Syntheses de molecules organiques marquees par le carbone-14 et le soufre-35

    Energy Technology Data Exchange (ETDEWEB)

    Pichat, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    After a brief history of the development of the Section des Molecules marquees of the Frenchmic Energy Commission, the author gives an outline of the synthesis of the following labelled compounds: benzene {sup 14}C-6; phenyl-p-fluorophenyl, thienyl-2 {beta} alanines {beta} {sup 14}C; noradrenaline {beta} {sup 14}C (arterenol {beta} {sup 14}C), dotriacontane {sup 14}C-16-17, aminoethane sulfinic acid (hypotaurine {sup 35}S). (author)Fren. [French] Apres un bref historique du developpement de la Section des Molecules marquees du Commissariat a l'Energie Atomique fran is, l'auteur donne un resume des syntheses des composes marques suivants: benzene {sup 14}C-6; phenyl-p-fluorophenyl, thienyl-2 {beta} alamines {beta} {sup 14}C; noradrenaline {beta} {sup 14}C (arterenol {beta} {sup 14}C), dotriacontane {sup 14}C-16-17, acide aminoethane sulfinique (hypotaurine {sup 35}S). (auteur)

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

    Science.gov (United States)

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

    2006-01-01

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

  8. Threshold groundwater ages and young water fractions estimated from 3H, 3He, and 14C

    Science.gov (United States)

    Kirchner, James; Jasechko, Scott

    2016-04-01

    It is widely recognized that a water sample taken from a running stream is not described by a single age, but rather by a distribution of ages. It is less widely recognized that the same principle holds true for groundwaters, as indicated by the commonly observed discordances between model ages obtained from different tracers (e.g., 3H vs 14C) in the same sample. Water age distributions are often characterized by their mean residence times (MRT's). However, MRT estimates are highly uncertain because they depend on the shape of the assumed residence time distribution (in particular on the thickness of the long-time tail), which is difficult or impossible to constrain with data. Furthermore, because MRT's are typically nonlinear functions of age tracer concentrations, they are subject to aggregation bias. That is, MRT estimates derived from a mixture of waters with different ages (and thus different tracer concentrations) will systematically underestimate the mixture's true mean age. Here, building on recent work with stable isotope tracers in surface waters [1-3], we present a new framework for using 3H, 3He and 14C to characterize groundwater age distributions. Rather than describing groundwater age distributions by their MRT, we characterize them by the fraction of the distribution that is younger or older than a threshold age. The threshold age that separates "young" from "old" water depends on the characteristics of the specific tracer, including its history of atmospheric inputs. Our approach depends only on whether a given slice of the age distribution is younger or older than the threshold age, but not on how much younger or older it is. Thus our approach is insensitive to the tails of the age distribution, and is therefore relatively unaffected by uncertainty in the distribution's shape. Here we show that concentrations of 3H, 3He, and 14C are almost linearly related to the fractions of water that are younger or older than specified threshold ages. These

  9. Effects of competitive red blood cell binding and reduced hematocrit on the blood and plasma levels of (/sup 14/C)Indapamide in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Lettieri, J.T.; Portelli, S.T.

    1983-02-01

    The effects of chlorthalidone and acetazolamide on the red blood cell binding of indapamide were investigated. Both drugs caused a substantial decrease in the amount of indapamide bound to the erythrocytes in vitro. This effect was demonstrated by a change in the indapamide blood/plasma ratio from approximately 6 in control samples, to a value of 1 when either of the displacing agents was added. Coadministration of acetazolamide with /sup 14/C-labeled indapamide to rats, resulted in a 5-fold drop in the blood levels of total radioactivity, relative to rats dosed with (/sup 14/C)indapamide alone. Concomitantly, there was a 2-fold increase in the plasma levels of total radioactivity after acetazolamide coadministration. In rats whose hematocrits had been reduced by extensive bleeding, there were only minor alterations in the blood/plasma partitioning of (/sup 14/C)indapamide. Thus, chlorthalidone and acetazolamide were able to displace indapamide from erythrocytes in vitro and in vivo, possibly by competition at a carbonic anhydrase binding site. The pharmacokinetics of drugs which are extensively bound to erythrocytes may be significantly altered by the presence of other agents capable of competitive binding.

  10. Performance of Helicobacter pylori acid extract and urease enzyme-linked immunosorbent assays in relation to 14C-urea breath test.

    Science.gov (United States)

    von Wulffen, H; Gatermann, S; Windler, E; Gabbe, E; Heinrich, H C

    1993-09-01

    The 14C-urea breath test has been shown to be a reliable non-invasive method to detect the presence or absence of H. pylori infection. Alternatively, a number of techniques have been devised to detect circulating antibodies against H. pylori in serum, the most commonly used being enzyme-linked immunosorbent assays (ELISA). In the present study we compared the value of two ELISA antigen preparations, an acid glycine extract and a urease preparation, in relation to the results achieved in a 14C-urea breath test. Seventy-five gastroenterology outpatients were screened for the presence of H. pylori infection using the urea breath test. At the same time serum specimens were obtained. Thirty-seven patients had a positive breath test, i.e. they expired more than 2% of the oral 14C test dose within 60 min. Using the breath test as reference, sensitivity and specificity for the acid extract were 89.2% and 84.2% respectively, and for the urease ELISA 81.1% and 89.5%. Agreement between the two ELISAs was found in 82.7%, overall agreement between all three tests was observed in 77.3%. All three tests were found to be useful for monitoring therapy directed against H. pylori.

  11. Direct measurement of stellar neutron capture rates of 14C and comparison with the Coulomb breakup method

    Science.gov (United States)

    Reifarth, Rene; Heil, M.; Plag, R.; Besserer, U.; Couture, A.; Dababneh, S.; Dörr, L.; Forssén, C.; Görres, J.; Haight, R. C.; Mengoni, A.; O'Brien, S.; Patronis, N.; Rundberg, R. S.; Uberseder, E.; Wiescher, M.; Wilhelmy, J. B.

    The neutron capture cross section of 14 C has been shown to be important for several neutron driven nucleosynthesis scenarios. Due to the high neutron abundance it is expected that the 14 C(n,γ) reaction competes strongly with other neutron-induced reactions on 14 C. The 14 C(n,γ) reaction is also important to validate (n,γ) cross sections obtained via the inverse reaction by the Coulomb breakup method. In principle, 14 C belongs to the few cases where this correspondence can be validated in a convincingly clean way. So far, the example of 14 C is obscured, however, by discrepancies between several experiments and theory. In this contribution we report on a re- analysis of the direct measurements of the 14 C(n,γ) reaction presented on the last NIC conference (Vancouver, 2004). The neutron energies used during the experiment ranged from 30 to 800 keV. The earlier presented disagreement between the direct measurements and the Coulomb breakup method has been resolved.

  12. Measuring transfer of {sup 14}C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Janle, E. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States)]. E-mail: janle@purdue.edu; Sojka, J. [Veterinary Clinical Sciences, Purdue University, West Lafayette, IN (United States); Jackson, G.S. [Department of Physics, Purdue University, West Lafayette, IN (United States); Lachcik, P. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States); Einstien, J.A. [Department of Physics, Purdue University, West Lafayette, IN (United States); Santerre, C.R. [Purdue University, Department of Foods and Nutrition, 700 West State Street, West Lafayette, IN 47907-2059 (United States)

    2007-06-15

    Environmental pollutants pose a substantial risk to nursing infants. Many of these toxicants (i.e. PCBs, PBDEs, mercury) are passed from the maternal diet to the nursing infant in breast milk. Determining the toxicokinetics has been difficult to measure due to ethical limitations. Since extremely small amounts of {sup 14}C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of {sup 14}C-labeled PCB (2,2',4,4',5,5'-hexachlorobiphenyl-UL-{sup 14}C) that could be given to a lactating animal and traced into the milk. An oral dose of 66 nCi/kg body weight (1.84 {mu}g PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of {sup 14}C label reached a peak value of 1.71 ng/ml PCB equivalents in the milk on day 2 and then declined to about 135 pg/ml PCB equivalents in the milk at 3 weeks. A second goat was administered a smaller dose (22 nCi/kg bw; 616 ng PCB/kg bw). A peak concentration of 485 pg PCB equivalents/ml milk occurred at 3 days and declined to 77.6 pg PCB equivalents/ml milk by 3 weeks. Our results indicated that an even lower dosage of labeled-PCB could be used due to the extreme sensitivity of AMS measurement. Extrapolating from current data it is estimated that the dose could be reduced by a factor of 20 (31 ng PCB/kg bw; 1.1 nCi/kg bw) and still be detectable after 2 months. Thus, the potential exists for developing protocols for studying toxicokinetics in humans using radiologically- and toxicologically-benign doses of labeled environmental toxicants.

  13. Insights from 14C into C loss pathways in degraded peatlands

    Science.gov (United States)

    Evans, Martin; Evans, Chris; Allott, Tim; Stimson, Andrew; Goulsbra, Claire

    2016-04-01

    Peatlands are important global stores of terrestrial carbon. Lowered water tables due to changing climate and direct or indirect human intervention produce a deeper aerobic zone and have the potential to enhance loss of stored carbon from the peat profile. The quasi continuous accumulation of organic matter in active peatlands means that the age of fluvial dissolved organic carbon exported from peatland systems is related to the source depth in the peat profile. Consequently 14C analysis of DOC in waters draining peatlands has the potential not only to tell us about the source of fluvial carbon and the stability of the peatland but also about the dominant hydrological pathways in the peatland system. This paper will present new radiocarbon determinations from peatland streams draining the heavily eroded peatlands of the southern Pennine uplands in the UK. These blanket peatland systems are highly degraded, with extensive bare peat and gully erosion resulting from air pollution during the industrial revolution, overgrazing, wildfire and climatic changes. Deep and extensive gullying has significantly modified the hydrology of these systems leading to local and more widespread drawdown of water table. 14C data from DOC in drainage waters are presented from two catchments; one with extensive gully erosion and the other with a combination of gully erosion and sheet erosion of the peat. At the gully eroded site DOC in drainage waters is as old as 160 BP but at the site with extensive sheet erosion dates of up to 1069 BP are amongst the oldest recorded from blanket peatland globally These data indicate significant degradation of stored carbon from the eroding peatlands. Initial comparisons of the 14C data with modelled water table for the catchments and depth-age curves for catchment peats suggests that erosion of the peat surface, allowing decomposition of exposed older organic material is a potential mechanism producing aged carbon from the eroded catchment. This

  14. Stellar delta matter with delta-meson coupling constants constrained by QCD sum rule

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Antonio Ferreira da [Secretaria de Educacao, Cultura e Desportos do Estado de Roraima (SECD/RR), Boa Vista, RR (Brazil); Oliveira, Jose Carlos Teixeira de [Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil); Rodrigues, Hilario [Centro Federal de Educacao Tecnologica (CEFET-RJ), Rio de Janeiro, RJ (Brazil); Duarte, Sergio Barbosa [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Chiapparini, Marcelo [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2010-07-01

    The considerable presence of delta-resonances (30% of baryonic population) in the dense phase of relativistic heavy ion collisions leads to a great interest in the study of the delta matter formation in the deep interior of compact stars. In the present work we determine the equation of state and the population of baryons and leptons and discuss the effects of the baryon-meson coupling constants to the formation of delta matter in the stellar medium. We use the non-linear Walecka model consisting of the octet of baryons of spin 1=2 (n, p, {Lambda}{sup 0}, {Sigma}{sup -}, {Sigma}{sup 0}, {Sigma}{sup +}, {Xi}{sup -}, {Xi}{sup 0}) and baryonic resonances of spin 3=2, represented by the delta resonances ({Delta}{sup -}, ({Delta}{sup 0}, ({Delta}{sup +}, ({Delta}{sup ++}) and {Omega}{sup -}, in the baryonic sector. In the leptonic sector we consider the electrons and muons. The coupling constants between the hyperons {Lambda}, {Sigma}, and {Xi} and the mesons {omega} and {rho} are fixed by using SU(6) symmetry, while the hyperons-{sigma} coupling constants are constrained by the consistence of the hypernuclear potential in the nuclear matter with hypernuclear data. In addition, we use the finite density QCD sum rule to determine the possible values of delta-meson coupling constants. (author)

  15. Effects of dietary supplementation of coriander oil, in canola oil diets, on the metabolism of [1-(14)C] 18:3n-3 and [1-(14)C] 18:2n-6 in rainbow trout hepatocytes.

    Science.gov (United States)

    Randall, K M; Drew, M D; Øverland, M; Østbye, T-K; Bjerke, M; Vogt, G; Ruyter, B

    2013-09-01

    The aim of this study was to investigate the effects of petroselinic acid, found in coriander oil, on the ability of rainbow trout hepatocytes to increase the production of eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA) from [1-(14)C] α-linolenic acid (18:3n-3; ALA) and to reduce the production of arachidonic acid (20:4n-6; ARA) from [1-(14)C] 18:2n-6. Addition of coriander oil increased the production of 22:6n-3, from [1-(14)C] 18:3n-3, at the 0.5 and 1.0% inclusion levels and reduced the conversion of [1-(14)C] 18:2n-6 to 20:4n-6. β-Oxidation was significantly increased at the 1.5% inclusion level for [1-(14)C] 18:2n-6, however β-oxidation for [1-(14)C] 18:3n-3 only showed an increasing trend. Acetate, a main breakdown product of fatty acids (FA) via peroxisomal β-oxidation, decreased three-fold for [1-(14)C] 18:2n-6 and nearly doubled for [1-(14)C] 18:3n-3 when coriander was added at a 1.5% inclusion level. Acyl coenzyme A oxidase (ACO) enzyme activity showed no significant differences between treatments. Relative gene expression of ∆6 desaturase decreased with addition of coriander oil compared to the control. The addition of petroselinic acid via coriander oil to vegetable oil (VO) based diets containing no fishmeal (FM) or fish oil (FO), significantly increased the production of anti-inflammatory precursor 22:6n-3 (P=0.011) and decreased pro-inflammatory precursor 20:4n-6 (P=0.023) in radiolabelled hepatocytes of rainbow trout.

  16. Efektivitas Suplementasi Giberelin (GA3) Untuk Meningkatkan Pertumbuhan dan Produktivitas Ulat Sutera (Bombyx mori L.) Serta Inkorporasi 14C-gIisin dan 14C-serin dalam kokon

    OpenAIRE

    2008-01-01

    Giberelin merupakan zat tumbuh tanaman yang dapat merangsang pertumbuhan dan perkembangan sel-sel tanaman. Penelitian ini bertujuan untuk mempelajari efektivitas giberelin (GA3) dalam merangsang pertumbuhan dan produktivitas ulat sutera (Bombyx mori L.) serta inkorporasi 14C-glisin dan 14C-serin dalam kokon. Metode yang digunakan adalah rancangan acak lengkap (RAL) dengan lima dosis perlakuan ( 0, 50, 100, 150, dan 200 ppm GA3) dan 30 ulangan. Hasil penelitian menunjukkan bahwa suplementasi g...

  17. New and revised 14C dates for Hawaiian surface lava flows: Paleomagnetic and geomagnetic implications

    Science.gov (United States)

    Pressline, N.; Trusdell, F.A.; Gubbins, David

    2009-01-01

    Radiocarbon dates have been obtained for 30 charcoal samples corresponding to 27 surface lava flows from the Mauna Loa and Kilauea volcanoes on the Island of Hawaii. The submitted charcoal was a mixture of fresh and archived material. Preparation and analysis was undertaken at the NERC Radiocarbon Laboratory in Glasgow, Scotland, and the associated SUERC Accelerator Mass Spectrometry facility. The resulting dates range from 390 years B.P. to 12,910 years B.P. with corresponding error bars an order of magnitude smaller than previously obtained using the gas-counting method. The new and revised 14C data set can aid hazard and risk assessment on the island. The data presented here also have implications for geomagnetic modelling, which at present is limited by large dating errors. Copyright 2009 by the American Geophysical Union.

  18. Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb (14)C

    DEFF Research Database (Denmark)

    Heinemeier, Katja Maria; Schjerling, Peter; Heinemeier, Jan

    2013-01-01

    Tendons are often injured and heal poorly. Whether this is caused by a slow tissue turnover is unknown, since existing data provide diverging estimates of tendon protein half-life that range from 2 mo to 200 yr. With the purpose of determining life-long turnover of human tendon tissue, we used...... turnover. Our observation provides a fundamental premise for understanding tendon function and pathology, and likely explains the poor regenerative capacity of tendon tissue.-Heinemeier, K. M., Schjerling, P., Heinemeier, J., Magnusson, S. P., Kjaer, M. Lack of tissue renewal in human adult Achilles tendon...... (donor birth years 1945-1983) with accelerator mass spectrometry (AMS) and compared to known atmospheric levels to estimate tissue turnover. We found that Achilles tendon tissue retained levels of 14C corresponding to atmospheric levels several decades before tissue sampling, demonstrating a very limited...

  19. Correlating the ancient Maya and modern European calendars with high-precision AMS 14C dating.

    Science.gov (United States)

    Kennett, Douglas J; Hajdas, Irka; Culleton, Brendan J; Belmecheri, Soumaya; Martin, Simon; Neff, Hector; Awe, Jaime; Graham, Heather V; Freeman, Katherine H; Newsom, Lee; Lentz, David L; Anselmetti, Flavio S; Robinson, Mark; Marwan, Norbert; Southon, John; Hodell, David A; Haug, Gerald H

    2013-01-01

    The reasons for the development and collapse of Maya civilization remain controversial and historical events carved on stone monuments throughout this region provide a remarkable source of data about the rise and fall of these complex polities. Use of these records depends on correlating the Maya and European calendars so that they can be compared with climate and environmental datasets. Correlation constants can vary up to 1000 years and remain controversial. We report a series of high-resolution AMS (14)C dates on a wooden lintel collected from the Classic Period city of Tikal bearing Maya calendar dates. The radiocarbon dates were calibrated using a Bayesian statistical model and indicate that the dates were carved on the lintel between AD 658-696. This strongly supports the Goodman-Martínez-Thompson (GMT) correlation and the hypothesis that climate change played an important role in the development and demise of this complex civilization.

  20. Persistence, fate, and metabolism of [(14)C]metalaxyl in typical Indian soils.

    Science.gov (United States)

    Sukul, P; Spiteller, M

    2001-05-01

    The biodegradation of ring-labeled [(14)C]metalaxyl in six Indian soils was examined. The total recovery of radioactivity from soil was 100 +/- 6% of the applied radioactivity. Volatile organics and (14)CO(2) were detected at lower levels. This suggests that neither mineralization nor volatilization is a major route of metalaxyl dissipation. The most rapid degradation of metalaxyl was observed in Bannimantap soil, in which the half-life of metalaxyl was 36 days. An inverse relationship was found when half-lives were plotted against microbial biomass and soil clay content. However, soil total organic carbon did not correlate with metalaxyl persistence. Five metabolites detected by thin-layer chromatography were more polar than metalaxyl.

  1. Distribution of /sup 14/C-ochratoxin A in the rainbow trout (Salmo gairdneri)

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, R.; Appelgren, L.-E.; Hult, K.

    1986-01-01

    The nephrotoxic mycotoxin ochratoxin A was studied in rainbow trout by whole-body autoradiography and scintillation counting using /sup 14/C-labelled toxin. After one single intravenous injection of 10 ..mu..Ci fish, corresponding to 160 ng toxin/g body weight, the tissue affinity was studied during an eight day period. As soon as 5 min. after injection the concentration of the radioactivity in the blood had dropped to one tenth of that in the kidney and the urinary bladder. The autoradiograms showed two patterns of blackening in the kidney, one diffuse in the pronephros and one very strong blackening in the opistonephros. In addition to the kidney very high concentrations of radioactivity were also noticed in the bile and the pseudobranch. The muscular tissue of treated trouts contained almost no radioactivity during the whole experiment. Chemical analysis revealed that the radioactivity that could be extracted from the organs was mainly ochratoxin A.

  2. Structure of $^{14}$C and $^{14}$O nuclei within a five-cluster model

    CERN Document Server

    Grinyuk, B E

    2016-01-01

    Within a five-particle model (three $\\alpha$-particles plus two nucleons), the structure functions of mirror nuclei $^{14}$C and $^{14}$O are studied. Using the variational approach with Gaussian bases, the energies and wave functions are calculated for these five-particle systems. Two spatial configurations in the ground-state wave function are revealed. The r.m.s. charge radius of $^{14}$O nucleus is found to be $2.415\\pm0.005$ fm. The charge density distributions and the form factors of both nuclei are predicted. The pair correlation functions are analyzed, and the r.m.s. relative distances are calculated. The momentum distributions of particles are found.

  3. Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA

    Science.gov (United States)

    Evans, William C.; Bergfeld, D.; McGeehin, J.P.; King, J.C.; Heasler, H.

    2010-01-01

    Mechanisms to explain swarms of shallow seismicity and inflation-deflation cycles at Yellowstone caldera (western United States) commonly invoke episodic escape of magma-derived brines or gases from the ductile zone, but no correlative changes in the surface efflux of magmatic constituents have ever been documented. Our analysis of individual growth rings in a tree core from the Mud Volcano thermal area within the caldera links a sharp ~25% drop in 14C to a local seismic swarm in 1978. The implied fivefold increase in CO2 emissions clearly associates swarm seismicity with upflow of magma-derived fluid and shows that pulses of magmatic CO2 can rapidly traverse the 5-kmthick brittle zone, even through Yellowstone's enormous hydrothermal reservoir. The 1978 event predates annual deformation surveys, but recognized connections between subsequent seismic swarms and changes in deformation suggest that CO2 might drive both processes. ?? 2010 Geological Society of America.

  4. Blood pH and brain uptake of /sup 14/C-morphine

    Energy Technology Data Exchange (ETDEWEB)

    Schulman, D.S.; Kaufman, J.J.; Eisenstein, M.M.; Rapoport, S.I.

    1984-11-01

    /sup 14/C-Morphine was injected iv in control awake rats or in rats subjected to metabolic alkalosis or acidosis. Ten minutes later, radioactivity was determined within each of seven brain regions, after correction was made for intravascular tracer. In each region, parenchymal radioactivity was correlated positively and significantly (P less than 0.05) with arterial blood pH. Brain radioactivity was twofold to threefold greater in alkalotic rats (mean pH . 7.62) than in acidotic rats (mean pH . 7.16). The results are consistent with the pH-partition hypothesis for drug entry into the brain and indicate that morphine uptake can be increased by elevating the fraction of lipid-soluble uncharged morphine base in blood, by means of alkalosis. The observations may account for an exaggerated morphine-induced analgesia in alkalotic patients.

  5. Bioaccumulation of 51Cr, 63Ni and 14C in Baltic Sea benthos.

    Science.gov (United States)

    Kumblad, L; Bradshaw, C; Gilek, M

    2005-03-01

    The Baltic Sea is a species-poor, semi-enclosed, brackish sea, whose sediments contain a wide range of contaminants, including sediment-associated metals and radionuclides. In this study, we have examined and compared bioaccumulation kinetics and assimilation efficiencies of sediment-associated (51)Cr, (63)Ni and (14)C in three key benthic invertebrates (the deposit-feeding Monoporeia affinis, the facultative deposit-feeding Macoma baltica, and the omnivorous Halicryptus spinulosus). Our results demonstrate that (i) all radionuclides were accumulated, (ii) the different radionuclides were accumulated to various extents, (iii) small changes in organic carbon concentration can influence the accumulation, and (iv) the degree of accumulation differed only slightly between species. These processes, together with sediment resuspension and bioturbation, may remobilise trace metals from the sediment to the water and to higher trophic levels, and therefore should be taken into account in exposure models and ERAs.

  6. Precise Study of Fine Structure in $^{14}$C Emission from $^{223}$Ra

    CERN Multimedia

    2002-01-01

    We request 10 shifts in two sessions of beam time at ISOLDE for the production of a $^{223}$Ra source. This source will be used with the superconducting spectrometer SOLENO at Orsay for a precise measurement (good statistics and energy resolution) of the fine stucture in the energy spectrum of $^{14}$C nuclei emitted by $^{223}$Ra, discovered at Orsay in July 1989. The measurement will be devoted to carry out the hindrance factors of the transitions to 15$\\!^-\\!$/2$\\,$ (1.423 MeV) and 5$\\!^+\\!$/2$\\,$ (1.567 MeV) excited states of $^{209}$Pb, which present a particular interest for obtaining spectroscopic information and testing nuclear models.

  7. \\Delta Y/ \\Delta Z from the analysis of local K dwarfs

    CERN Document Server

    Gennaro, Mario; Degl'Innocenti, Scilla

    2010-01-01

    The stellar helium-to-metal enrichment ratio, \\Delta Y/\\Delta Z, is a widely studied astrophysical quantity. However, its value is still not precisely constrained. This paper is focused on the study of the main sources of uncertainty which affect the \\Delta Y/\\Delta Z derived from the analysis of the low-main sequence (MS) stars in the solar neighborhood. The possibility to infer the value of \\Delta Y/\\Delta Z from the study of low-MS stars relies on the dependence of the stellar luminosity and effective temperature on the initial Y and Z. The \\Delta Y/\\Delta Z ratio is obtained by comparing the magnitude difference between the observed stars and a reference theoretical zero age main sequence (ZAMS) with the related theoretical magnitude differences computed from a new set of stellar models with up-to-date input physics and a fine grid of chemical compositions. A Monte Carlo approach has been used to evaluate the impact on the result of different sources of uncertainty, i.e. observational errors, evolutionary...

  8. Metabolite profiling of bendamustine in urine of cancer patients after administration of [14C]bendamustine.

    Science.gov (United States)

    Dubbelman, Anne-Charlotte; Jansen, Robert S; Rosing, Hilde; Darwish, Mona; Hellriegel, Edward; Robertson, Philmore; Schellens, Jan H M; Beijnen, Jos H

    2012-07-01

    Bendamustine is an alkylating agent consisting of a mechlorethamine derivative, a benzimidazole group, and a butyric acid substituent. A human mass balance study showed that bendamustine is extensively metabolized and subsequently excreted in urine. However, limited information is available on the metabolite profile of bendamustine in human urine. The objective of this study was to elucidate the metabolic pathways of bendamustine in humans by identification of its metabolites excreted in urine. Human urine samples were collected up to 168 h after an intravenous infusion of 120 mg/m(2) (80-95 μCi) [(14)C]bendamustine. Metabolites of [(14)C]bendamustine were identified using liquid chromatography (high-resolution)-tandem mass spectrometry with off-line radioactivity detection. Bendamustine and a total of 25 bendamustine-related compounds were detected. Observed metabolic conversions at the benzimidazole and butyric acid moiety were N-demethylation and γ-hydroxylation. In addition, various other combinations of these conversions with modifications at the mechlorethamine moiety were observed, including hydrolysis (the primary metabolic pathway), cysteine conjugation, and subsequent biotransformation to mercapturic acid and thiol derivatives, N-dealkylation, oxidation, and conjugation with phosphate, creatinine, and uric acid. Bendamustine-derived products containing phosphate, creatinine, and uric acid conjugates were also detected in control urine incubated with bendamustine. Metabolites that were excreted up to 168 h after the infusion included products of dihydrolysis and cysteine conjugation of bendamustine and γ-hydroxybendamustine. The range of metabolic reactions is generally consistent with those reported for rat urine and bile, suggesting that the overall processes involved in metabolic elimination are qualitatively the same in rats and humans.

  9. Development of a nanofiltration method for bone collagen {sup 14}C AMS dating

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu, E-mail: mathieu.boudin@ugent.be [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Boeckx, Pascal [Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Buekenhoudt, Anita [Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, B-2400 Mol (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Van Strydonck, Mark [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium)

    2013-01-15

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased {sup 14}C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) {approx}100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. {sup 14}C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant

  10. Metabolism of /sup 14/C-labeled doxylamine succinate (Bendectin) in the rhesus monkey (Macaca mulatta)

    Energy Technology Data Exchange (ETDEWEB)

    Slikker, W. Jr.; Holder, C.L.; Lipe, G.W.; Korfmacher, W.A.; Thompson, H.C. Jr.; Bailey, J.R.

    1986-05-01

    The time-course of the metabolic fate of (/sup 14/C)doxylamine was determined after the p.o. administration of 13 mg/kg doxylamine succinate as Bendectin plus (/sup 14/C)doxylamine succinate to the rhesus monkey. Urine and plasma samples were analyzed by reversed-phase high performance liquid chromatography (HPLC), chemical derivatization, and mass spectrometry. The cumulative 48-hr urinary metabolic profile contained 81% of the administered radiolabeled dose and consisted of at least six radiolabeled peaks. They were peak 1: unknown polar metabolites (8% of dose); peak 2: 2-(1-phenyl-1-(2-pyridinyl)ethoxy) acetic acid, 1-(1-phenyl-1(2-pyridinyl)ethoxy) methanol, and another minor metabolite(s) (31%); peak 3: doxylamine-N-oxide (1%); peak 4a: N,N-didesmethyldoxylamine (17%); peak 4b: doxylamine (4%); and peak 5: N-desmethyldoxylamine (20%). The plasma metabolic profile was the same as the urinary profile except for the absence of doxylamine-N-oxide. The maximum plasma concentrations and elapsed time to attain these concentrations were as follows. Peak 1: 540 ng/mL, 4 hr; peak 2: 1700 ng/mL, 1 hr; peak 4a: 430 ng/mL, 4 hr; peak 4b: 930 ng/mL, 2 hr; and peak 5: 790 ng/mL, 2 hr. These data suggest that in the monkey, doxylamine metabolism follows at least four pathways: a minor pathway to the N-oxide; a minor pathway to unknown polar metabolites; a major pathway to mono- and didesmethyldoxylamine via successive N-demethylation; and a major pathway to side-chain cleavage products (peak 2) via direct side-chain oxidation and/or deamination.

  11. Development of a nanofiltration method for bone collagen 14C AMS dating

    Science.gov (United States)

    Boudin, Mathieu; Boeckx, Pascal; Buekenhoudt, Anita; Vandenabeele, Peter; Van Strydonck, Mark

    2013-01-01

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

  12. Antifungal Activity of Cumin Oil Against Candida parapsilosis SS25, C. orthopsilosis NN14, C. metapsilosis MP27, and C. etchellsii MP18.

    Directory of Open Access Journals (Sweden)

    Wellyzar Sjamsuridzal4

    2011-04-01

    Full Text Available Antifungal Activity of Cumin Oil Against Candida parapsilosis SS25, C. orthopsilosis NN14, C. metapsilosisMP27, and C. etchellsii MP18. Many kinds of spices are used in Indonesia, one of them is white cumin seed. Thisspice is used not only for cooking, but also for traditional medicine. This study reported of antifungal activity fromwhite cumin’s essential oil. Extraction and identification of Cumin oil were carried out. We obtained 2.5-3.0% of whiteessential oil which was colorless or light yellow color. GCMS analysis revealed that there were 12 peaks. Based onpeak’s intensity the oil were dominated by 4 compound i.e. cuminaldehide (35.44%, ρ-cymene (34.77%, β-pynene(15.08 % and γ-terpinene (8.15%. Growth inhibition zone determination has been carried out by diffusion disc anddirect method against yeast i.e. C. parapsilosis SS25, C. orthopsilosis NN14, C. metapsilosis MP27, and C. etchellsiiMP18. The results showed that all of the yeasts were sensitive to cumin oil. The inhibition zone radius were 13.4-16.5mm. The cumin oil showed the inhibition of yeast growth with MIC values of 0.028%-0.042% and MFC values 0.09%-0.14%, while nystatin had MIC values 0.40%-0.50% and MFC values 3.0%-4.0%. The activity of cumin oil was verystrong as antifungal.

  13. Uptake and expulsion of sup 14 C-xylitol by xylitol-cultured Streptococcus mutans ATCC 25175 in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Soederling, E.; Pihlanto-Leppaelae, A. (Department of Biochemistry, Institute of Dentistry, University of Turku, Turku (Finland))

    1989-01-01

    The effect of successive cultivations in the presence of 6% xylitol on the uptake and expulsion of {sup 14}C-xylitol was studied using the cells of Streptococcus mutans 25175. Three sequential cultivations did not alter the growth inhibition percentage (approximately 50%) observed in the presence of 6% xylitol. The {sup 14}C-xylitol uptake experiments performed with growing and resting cells showed that both the uptake and the expulsion of xylitol were enhanced by xylitolculturing. Both xylitol-cultured and resting control cells contained only one major labeled compound which was identified as {sup 14}C-xylitol 5-phosphate. The label subsequently was expelled from the cells as {sup 14}C-xylitol. These results indicate that S. mutans possesses an intracellular xylitol cycle and this cycle is regulated by adding xylitol to the growth medium. (author).

  14. In vivo inhibition of incorporation of (U-/sup 14/C)glucose into proteins in experimental focal epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Coutinho-Netto, J.; Boyar, M.M.; Abdul-Ghani, A.S.; Bradford, H.F.

    1982-08-01

    The in vivo incorporation of (/sup 14/C) from (U-/sup 14/C)-glucose into rat brain proteins from different cortical areas was examined in three different experimental focal epilepsies: cobalt, freeze-lesions, and tityustoxin. When (U-/sup 14/C)-glucose was injected intraperitoneally into awake and unrestrained animals with marked signs of epileptic hyperactivity, the inhibition of incorporation of (/sup 14/C)-amino acids into trichloracetic acid (TCA)-insoluble proteins was highest in the focal (sensorimotor) area when compared with distant regions (approx. 60%), but less when compared with the contralateral (sensorimotor) region (approx. 23%). Greatly decreased incorporation caused by both cobalt and freeze-lesion-induced epilepsies was also observed in the contralateral area when a comparison was made with distant regions (approx. 50%), but there were no significant differences in protein-specific radioactivity between the different distant areas.

  15. Elastic and inelastic scattering of {sup 14}C + {sup 11}B versus {sup 12,13}C + {sup 11}B

    Energy Technology Data Exchange (ETDEWEB)

    Mezhevych, S.Yu.; Rudchik, A.T.; Rudchik, A.A. [Institute for Nuclear Research, Kyiv (Ukraine); Rusek, K. [National Institute for Nuclear Research, Warsaw (Poland); Heavy Ion Laboratory of Warsaw University, Warsaw (Poland); Kemper, K.W. [Florida State University, Physics Department, Tallahassee, Florida (United States); Kliczewski, S.; Czech, B.; Siudak, R.; Szczurek, A. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland); Koshchy, E.I. [Kharkiv National University, Kharkiv (Ukraine); Sakuta, S.B. [Russian Research Center ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Choinski, J. [Heavy Ion Laboratory of Warsaw University, Warsaw (Poland)

    2014-01-15

    Complete angular distributions of the {sup 14}C + {sup 11}B elastic and inelastic scattering at the energy E{sub lab}({sup 11}B) = 45 MeV were measured for the ground and excited states of {sup 11}B. The data were analyzed within the optical model and the coupled-reaction-channels method. The parameters of the {sup 14}C + {sup 11}B optical potential and {sup 11}B deformation were deduced. The contributions of one- and two-step transfers of nucleons and clusters into the {sup 14}C + {sup 11}B elastic and inelastic scattering were calculated. The isotopic differences between the {sup 14}C + {sup 11}B and {sup 12,13}C + {sup 11}B scatterings are presented and clearly show the importance of the large angle scattering data for understanding the interaction between light heavy ions. (orig.)

  16. New historical records and relationships among 14C production rates, abundance and color of low latitude auroras and sunspot abundance

    Science.gov (United States)

    Abbott, Dallas; Juhl, Robert

    2016-12-01

    Incursions of high-energy particles from space, specifically solar energetic particles and galactic cosmic rays, have significant effects on the Earth, including disruption of the Earth's magnetic field, generation of electric fields strong enough to damage electronic devices as well as the production of auroras at low-latitudes, within 45° of the magnetic equator. We examine the relationships among 14C production, auroral abundance, auroral color and sunspot abundance using existing data supplemented by a new dataset. The new dataset, based on Chinese and Korean records from A.D. 1100-1700, includes 46 new or revised records of sunspots and 279 records of low-latitude auroras. Low-latitude auroras are predominantly red (66%, 835 events) with lesser proportions of white (20%, 253 events) and black auroras (6%, 67 events). All other auroral colors (green, yellow, multicolored, blue and purple) aggregate to a total of 100 events (8%). Overall, white auroras are more frequent during times of higher 14C production. We use two empirical methods of evaluating the flux of high-energy particles: modeled peaks and lows in 14C production and peaks and lows in the 14C calibration curve. We find that comparison to modeled 14C production gives significant results. White auroras are significantly more abundant (98% probability) at times of high production of 14C. Red auroras are somewhat more abundant (88% probability) at times of low production of 14C. The abundances of black, multicolored, green, yellow, and blue auroras between times of low and high 14C production are not significantly different. Violet/purple auroras are significantly more abundant (98% probability) at times of low 14C production. The positive correlation of violet/purple auroras with times of low14C production rate and the lack of correlation of blue auroras with times of high14C production is surprising, for this portion of the visible spectrum contains strong emission lines and some lines with high

  17. Transplacental and mammary passage of radioactivity in rats treated vaginally and orally with (/sup 14/C)propranolol

    Energy Technology Data Exchange (ETDEWEB)

    Buttar, H.S.; Moffatt, J.H.; Bura, C.

    1988-01-01

    Single doses (10 mg/kg) of an aqueous solution of (14C)propranolol were administered either orally (po) or intravaginally (ivg) on gestational d 15, or on postpartum d 7-10. Upon ivg administration, (14C)propranolol was quickly transferred to systemic circulation and the mean blood (14C) concentrations were significantly greater during the first 0.25-2 h than in po dosed counterparts. About 98% of the ivg applied dose was absorbed after 6 h in gravid rats, and the combined 6-h excretions of radioactivity in the urine (ivg = 24.6%; po = 22.9%) and feces (ivg = 16.8%; po = 14.6%) were equivalent in both groups. At the end of 6 h, the levels of (14C) in the urinary bladder, adrenal, uterus, ovary, spleen, skeletal muscle, brain, heart, lung and fat were significantly higher in ivg treated rats than po dosed animals. Compared with the maternal plasma (ivg = 0.76; po = 0.88 microgram/ml), the mean concentrations of (14C) in the placentas were similar in both groups, while the amounts of (14C) were three to five times lower in the amniotic fluids and the fetuses of both po and ivg treated dams. In lactating rats, over 99% of the administered radioactivity was absorbed from the vagina within 6 h. The blood concentrations of (14C) were significantly elevated at 0.5 and 1 h in the per vaginam treated animals, and afterward the disappearance rate of (14C) followed a similar course in both groups. Following ivg application, the milk radioactivity peaked at 0.5 h and declined rapidly. However, the appearance of (14C) in milk was rather slow after oral dosing: the milk (14C) peaked between 2 and 3 h posttreatment and remained steady thereafter. The milk to blood (M/B) (14C) concentration ratios were markedly greater during 0.5 to 1 h in the ivg group than in their po dosed counterparts.

  18. Laboratory degradation studies of 14C-atrazine and -isoproturon in soil from sugarcane cultivated fields under Kenyan tropical conditions.

    Science.gov (United States)

    Getenga, Z M; Dörfler, U; Schroll, R

    2009-06-01

    A study to compare the degradation rates of atrazine (6-chloro-N(2)-ethyl-N(4)-isopropyl-1,3,5-triazine-2,4-diammine) and isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] in soils from sugarcane fields with different practices of herbicides application was carried out. (14)C-atrazine was poorly mineralized to (14)CO(2) (1.10% +/- 0.22%) after 139 days of incubation in soil without previous exposure to atrazine. In the same soil also with no previous isoproturon exposure isoproturon was mineralized to (14)CO(2) by 7.70% +/- 0.94%. Atrazine mineralization after 98 days was 13.4% +/- 0.30% in soil which discontinued the use of atrazine in 1997 while it was 89.9% +/- 1.23% in soil in which atrazine is currently being used. The isoproturon mineralization values were 7.24% +/- 0.85% and 22.97% +/- 0.96% in soil which discontinued atrazine and soil currently using atrazine, respectively.

  19. A new procedure for extraction of collagen from modern and archaeological bones for {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Maspero, F. [CUDaM, University of Milano Bicocca, Milano (Italy); Sala, S.; Papagni, A. [University of Milano Bicocca, Materials Science Department, Milano (Italy); Fedi, M.E. [INFN sezione di Firenze, Sesto Fiorentino (Firenze) (Italy); Martini, M. [CUDaM, University of Milano Bicocca, Milano (Italy); University of Milano Bicocca, Materials Science Department, Milano (Italy); INFN sezione di Milano Bicocca, Milano (Italy)

    2011-10-15

    Bones are potentially the best age indicators in a stratigraphic study, because they are closely related to the layer in which they are found. Collagen is the most suitable fraction and is the material normally used in radiocarbon dating. Bone contaminants can strongly alter the carbon isotopic fraction values of the samples, so chemical pretreatment for {sup 14} C dating by accelerator mass spectrometry (AMS) is essential. The most widespread method for collagen extraction is based on the Longin procedure, which consists in HCl demineralization to dissolve the inorganic phase of the samples, followed by dissolution of collagen in a weak acid solution. In this work the possible side effects of this procedure on a modern bone are presented; the extracted collagen was analyzed by ATR-IR spectroscopy. An alternative procedure, based on use of HF instead of HCl, to minimize unwanted degradation of the organic fraction, is also given. A study by ATR-IR spectroscopic analysis of collagen collected after different demineralization times and with different acid volumes, and a study of an archaeological sample, are also presented. (orig.)

  20. Synthesis of disodium-3-amino-1-hydroxypropane-1, 1-diphosphonate-1-/sup 14/C. (APD. 2Na)

    Energy Technology Data Exchange (ETDEWEB)

    Magnien, E.; Shaikh, M.; Suh, J.T.; Jones, H. (Revlon Health Care Group, Tuckahoe, New York (USA))

    1982-10-01

    Disodium-3-amino-1-hydroxy-1, 1-diphosphonate-1-/sup 14/C (APD 2Na), a powerful calcium binding agent and potential drug for the treatment of Paget's Disease was synthesized. The reaction was carried out by reacting ..beta..-alanine (1-/sup 14/C) with phosphorus acid and phosphorus trichloride in chlorobenzene. Treatment of the resultant APD with two equivalents of sodium hydroxide gave the title compound.

  1. Synthesis of carbon-14 analogue of 1,5 diaryl-5-[{sup 14}C]-1,2,3-triazoles

    Energy Technology Data Exchange (ETDEWEB)

    Matloubi, Hojatollah E-mail: hmatloubi@aeoi.org.ir; Shafiee, Abbas; Saemian, Nader; Shirvani, Gholamhossein; Daha, Fariba Johari

    2004-05-01

    Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-methyl-phenyl)-1,2,3-triazole and 1-(4-methylsulfone-phenyl)-5-phenyl-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-tolunitrile-[cyano-{sup 14}C] and benzonitrile-[cyano-{sup 14}C], respectively.

  2. The radioactivity estimation of 14C and 3H in graphite waste samples of the KRR-2.

    Science.gov (United States)

    Reyoung Kim, Hee

    2013-09-01

    The radioactivity of (14)C and (3)H in graphite samples from the dismantled Korea Research Reactor-2 (the KRR-2) site was analyzed by high-temperature oxidation and liquid scintillation counting, and the graphite waste was suggested to be disposed of as a low-level radioactive waste. The graphite samples were oxidized at a high temperature of 800 °C, and their counting rates were measured by using a liquid scintillation counter (LSC). The combustion ratio of the graphite was about 99% on the sample with a maximum weight of 1g. The recoveries from the combustion furnace were around 100% and 90% in (14)C and (3)H, respectively. The minimum detectable activity was 0.04-0.05 Bq/g for the (14)C and 0.13-0.15 Bq/g for the (3)H at the same background counting time. The activity of (14)C was higher than that of (3)H over all samples with the activity ratios of the (14)C to (3)H, (14)C/(3)H, being between 2.8 and 25. The dose calculation was carried out from its radioactivity analysis results. The dose estimation gave a higher annual dose than the domestic legal limit for a clearance. It was thought that the sampled graphite waste from the dismantled research reactor was not available for reuse or recycling and should be monitored as low-level radioactive waste. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. /sup 14/C-labelled propoxur metabolic studies on Anopheles Stephensi from the south coast of Iran

    Energy Technology Data Exchange (ETDEWEB)

    Hossaini, M.A.; Manouchehri, A.V.; Zareh, Z. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

    1984-08-01

    /sup 14/C-propoxur (Baygonsub(circled R)) was synthesized through the reaction of o-isopropoxyphenol with methyl isocyanate-/sup 14/C. The product was isolated chromatographically on Florisil and crystallized from carbon tetrachloride. The purity and structure were confirmed using infrared spectra, melting point, co-chromatography of Florisil column, and silica-gel G thin-layer chromatography. The purity was found to be at least 99%. The rate of absorption and other characteristics of /sup 14/C-propoxur resistance in Anopheles Stephensi from the south coast of Iran was investigated. The mortality of strain adults was 100% after a one hour exposure when 1 ppm /sup 14/C-propoxur was used. Moreover, the mortality was not changed when a lower concentration (5 ppm) was used. On the other hand, the absorbance of /sup 14/C-propoxur in several strains of A. Stephensi has been determined. The identity and TLC characteristics of products formed after 1 and 2 hours exposure, resp., to /sup 14/C-propoxur have also been investigated. 5 refs.

  4. Increased root exudation of /sup 14/C-compounds by sorghum seedlings inoculated with nitrogen-fixing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.J. (Institute of Forest Genetics, Suweon (Republic of Korea)); Gaskins, M.H. (Florida Univ., Gainesville (USA). Dept. of Agriculture)

    1982-01-01

    Organic components leaked from Sorghum bicolor seedlings ('root exudates') were examined by recovering /sup 14/C labelled compounds from root solutions of seedlings inoculated with Azospirillum brasilense, Azotobacter vinelandii or Klebsiella pneumoniae nif-. Up to 3.5% of the total /sup 14/C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and Azotobacter increased the amounts of /sup 14/C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria, the increase of /sup 14/C in the solutions did not occur. Quantities of /sup 14/C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with /sup 14/CO/sub 2/, about 15% of the total /sup 14/C recovered within 48 hours exposure was found in soil leachates.

  5. Delta hedging strategies comparison

    DEFF Research Database (Denmark)

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

    2008-01-01

    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model ...

  6. MODIFICATION OF DELTA FOR CHOOSER OPTIONS

    Directory of Open Access Journals (Sweden)

    Marek Ďurica

    2015-09-01

    Full Text Available Correctly used financial derivatives can help investors increase their expected returns and minimize their exposure to risk. To ensure the specific needs of investors, a large number of different types of non-standard exotic options is used. Chooser option is one of them. It is an option that gives its holder the right to choose at some predetermined future time whether the option will be a standard call or put with predetermined strike price and maturity time. Although the chooser options are more expensive than standard European-style options, in many cases they are a more suitable instrument for investors in hedging their portfolio value. For an effective use of the chooser option as a hedging instrument, it is necessary to check the values of the Greek parameters delta and gamma for the options. Especially, if the value of the parameter gamma is too large, hedging of the portfolio value using only parameter delta is insufficient and brings high transaction costs because the portfolio has to be reviewed relatively often. Therefore, in this article, a modification of delta-hedging as well as using the value of parameter gamma is suggested. Error of the delta modification is analyzed and compared with the error of widely used parameter delta. Typical patterns for the modified hedging parameter variation with various time to choose time for chooser options are also presented in this article.

  7. Erythromycin and azithromycin transport into Haemophilus influenzae ATCC 19418 under conditions of depressed proton motive force (delta mu H)

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco, J.O.; Goldman, R.C. (Abbott Laboratories, IL (USA))

    1990-09-01

    The effect of collapsing the electrochemical proton gradient (delta mu H) on ({sup 3}H)erythromycin and ({sup 14}C)azithromycin transport in Haemophilus influenzae ATCC 19418 was studied. The proton gradient and membrane potential were determined from the distribution of (2-{sup 14}C)dimethadione and rubidium-86, respectively. delta mu H was reduced from 124 to 3 mV in EDTA-valinomycin-treated cells at 22{degrees}C with 150 mM KCl and 0.1 mM carbonyl cyanide m-chlorophenylhydrazone. During the collapse of delta mu H, macrolide uptake increased. Erythromycin efflux studies strongly suggested that this increase was not due to an energy-dependent efflux pump but was likely due to increased outer membrane permeability. These data indicated that macrolide entry was not a delta mu H-driven active transport process but rather a passive diffusion process.

  8. Horizontal Symmetries $\\Delta(150)$ and $\\Delta(600)$

    CERN Document Server

    Lam, C S

    2013-01-01

    Using group theory of mixing to examine all finite subgroups of SU(3) with an order less than 512, we found recently that only the group $\\Delta(150)$ can give rise to a correct reactor angle $\\th_{13}$ of neutrino mixing without any free parameter. It predicts $\\sin^22\\th_{13}=0.11$ and a sub-maximal atmospheric angle with $\\sin^22\\th_{23}=0.94$, in good agreement with experiment. The solar angle $\\th_{12}$, the CP phase $\\d$, and the neutrino masses $m_i$ are left as free parameters. In this article we provide more details of this case, discuss possible gain and loss by introducing right-handed symmetries, and/or valons to construct dynamical models. A simple model is discussed where the solar angle agrees with experiment, and all its mixing parameters can be obtained from the group $\\Delta(600)$ by symmetry alone. The promotion of $\\Delta(150)$ to $\\Delta(600)$ is on the one hand analogous to the promotion of $S_3$ to $S_4$ in the presence of tribimaximal mixing, and on the other hand similar to the extens...

  9. Fate of 14C-labeled dissolved organic matter in paddy and upland soils in responding to moisture.

    Science.gov (United States)

    Chen, Xiangbi; Wang, Aihua; Li, Yang; Hu, Lening; Zheng, Hua; He, Xunyang; Ge, Tida; Wu, Jinshui; Kuzyakov, Yakov; Su, Yirong

    2014-08-01

    Soil organic matter (SOM) content in paddy soils is higher than that in upland soils in tropical and subtropical China. The dissolved organic matter (DOM) concentration, however, is lower in paddy soils. We hypothesize that soil moisture strongly controls the fate of DOM, and thereby leads to differences between the two agricultural soils under contrasting management regimens. A 100-day incubation experiment was conducted to trace the fate and biodegradability of DOM in paddy and upland soils under three moisture levels: 45%, 75%, and 105% of the water holding capacity (WHC). (14)C labeled DOM, extracted from the (14)C labeled rice plant material, was incubated in paddy and upland soils, and the mineralization to (14)CO2 and incorporation into microbial biomass were analyzed. Labile and refractory components of the initial (14)C labeled DOM and their respective half-lives were calculated by a double exponential model. During incubation, the mineralization of the initial (14)C labeled DOM in the paddy soils was more affected by moisture than in the upland soils. The amount of (14)C incorporated into the microbial biomass (2.4-11.0% of the initial DOM-(14)C activity) was less affected by moisture in the paddy soils than in the upland soils. At any of the moisture levels, 1) the mineralization of DOM to (14)CO2 within 100 days was 1.2-2.1-fold higher in the paddy soils (41.9-60.0% of the initial DOM-(14)C activity) than in the upland soils (28.7-35.7%), 2) (14)C activity remaining in solution was significantly lower in the paddy soils than in the upland soils, and 3) (14)C activity remaining in the same agricultural soil solution was not significantly different among the three moisture levels after 20 days. Therefore, moisture strongly controls DOM fate, but moisture was not the key factor in determining the lower DOM in the paddy soils than in the upland soils. The UV absorbance of DOM at 280 nm indicates less aromaticity of DOM from the paddy soils than from the

  10. Factors influencing 14C concentrations of algal and archaeal lipids and their associated sea surface temperature proxies in the Black Sea

    Science.gov (United States)

    Kusch, Stephanie; Rethemeyer, Janet; Hopmans, Ellen C.; Wacker, Lukas; Mollenhauer, Gesine

    2016-09-01

    Understanding the preservation and deposition history of organic molecules is crucial for the understanding of paleoenvironmental information contained in their abundance ratios such as Uk‧37 and TEX86 used as proxies for sea surface temperature (SST). Based on their relatively high refractivity, alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) can survive postdepositional processes like lateral transport, potentially causing inferred SSTs to be misleading. Likewise, selective preservation of alkenones and GDGTs may cause biases of the SST proxies themselves and can lead to decoupling of both proxy records. Here we report compound-specific radiocarbon data of marine biomarkers including alkenones, GDGTs, and low molecular weight (LMW) n-fatty acids from Black Sea sediments deposited under different redox regimes to evaluate the potentially differential preservation of both biomarker classes and its effect on the SST indices Uk‧37 and TEX86. The decadal Δ14C values of alkenones, GDGTs, and LMW n-fatty acids indicate similar preservation under oxic, suboxic, and anoxic redox regimes and no contribution of pre-aged compounds, e.g., by lateral supply. Moreover, similar 14C concentrations of crenarchaeol, alkenones, and LMW n-fatty acids imply that the thaumarchaeotal GDGTs preserved in these sediments are produced in the euphotic zone rather than in subsurface/thermocline waters. However, we observe biomarker-based SSTs that strongly deviate (ΔSST up to 8.4 °C) from in situ measured mean annual SSTs in the Black Sea. This is not due to redox-dependent differential biomarker preservation as implied by their Δ14C values and spatial SST pattern. Since contributions from different sources can largely be excluded, the deviation of the Uk‧37 and TEX86 proxy-derived SSTs from in situ SSTs requires further study of phylogenetic and other yet unknown environmental controls on alkenone and GDGT lipid distributions in the Black Sea.

  11. Optimizing Industrial Value Chain in Yangtze River Delta based on B2B Platform%基于B2B平台的长三角产业价值链升级研究

    Institute of Scientific and Technical Information of China (English)

    刘辉

    2013-01-01

    根据价值链和电子商务理论与实践可以发现, B2B电子商务平台正在改变产业价值链模式,为提升产业价值链带来新的战略途径。长三角内外产业价值链的正在经历跨边界重组,较为发达的B2B平台环境则提供了重要的技术条件。以阿里巴巴为例分析来看, B2B平台中存在着国内和国外两类产业价值链的复杂嵌套,而国内企业在全球价值链中还基本处在低端位置。 B2B电子商务平台支持的产业价值链租金是长三角价值链高级化的基本动力之一;长三角未来应有意识地引导充分利用中心城市的比较聚集优势,政府通过宏观协调,形成发挥B2B平台优势的产业环境,通过B2B电子商务平台激活高级要素,采取全球产业价值链与国内产业价值链并建的策略。%According to value chain and e-commerce theories and practice, it is found that the B2B platform is changing the industrial value chain model, and innovating the strategy to enhance the value chain of the industry. While the boom of B2B plat-form in Yangtze River Delta is creating new industrial environment, the industrial value chain is witnessing an unprecedented cross boundary recombination. Take the well-known Alibaba B2B as example, which enjoys more than 60% market share in Chi-na, it is found that both domestic and global industrial value chain exists and even nested on the platform. Further observations re-vealed that domestic enterprises in the global value chain are still in the low-end position. In order to solve this problem , B2B platforms could make play a unique role to upgrade the two value chain. Local government should make full use of regional center cities through the macroeconomic coordination, enjoying as much spillover effects as possible from the B2B platform.

  12. CO2 increases 14C primary production in an Arctic plankton community

    Directory of Open Access Journals (Sweden)

    A. Engel

    2013-03-01

    Full Text Available Responses to ocean acidification in plankton communities were studied during a CO2-enrichment experiment in the Arctic Ocean, accomplished from June to July 2010 in Kongsfjorden, Svalbard (78°56′ 2′′ N, 11°53′ 6′′ E. Enclosed in 9 mesocosms (volume: 43.9–47.6 m3, plankton was exposed to CO2 concentrations, ranging from glacial to projected mid-next-century levels. Fertilization with inorganic nutrients at day 13 of the experiment supported the accumulation of phytoplankton biomass, as indicated by two periods of high chl a concentration. This study tested for CO2 sensitivities in primary production (PP of particulate organic carbon (PPPOC and of dissolved organic carbon (PPDOC. Therefore, 14C-bottle incubations (24 h of mesocosm samples were performed at 1 m depth receiving about 60% of incoming radiation. PP for all mesocosms averaged 8.06 ± 3.64 μmol C L−1 d−1 and was slightly higher than in the outside fjord system. Comparison between mesocosms revealed significantly higher PPPOC at elevated compared to low pCO2 after nutrient addition. PPDOC was significantly higher in CO2-enriched mesocosms before as well as after nutrient addition, suggesting that CO2 had a direct influence on DOC production. DOC concentrations inside the mesocosms increased before nutrient addition and more in high CO2 mesocosms. After addition of nutrients, however, further DOC accumulation was negligible and not significantly different between treatments, indicating rapid utilization of freshly produced DOC. Bacterial biomass production (BP was coupled to PP in all treatments, indicating that 3.5 ± 1.9% of PP or 21.6 ± 12.5% of PPDOC provided on average sufficient carbon for synthesis of bacterial biomass. During the later course of the bloom, the response of 14C-based PP rates to CO2 enrichment differed from net community production (NCP rates that were also determined during this mesocosm campaign. We conclude that the enhanced release of

  13. CO2 increases 14C-primary production in an Arctic plankton community

    Directory of Open Access Journals (Sweden)

    R. Bellerby

    2012-08-01

    Full Text Available Responses to ocean acidification in plankton communities were studied during a CO2-enrichment experiment in the Arctic Ocean, accomplished from June to July 2010 in Kongsfjorden, Svalbard (78°56, 2' N, 11°53, 6' E. Enclosed in 9 mesocosms (volume: 43.9–47.6 m3, plankton was exposed to CO2 concentrations, ranging from glacial to projected mid-next-century levels. Fertilization with inorganic nutrients at day 13 of the experiment supported the accumulation of phytoplankton biomass, as indicated by two periods of high Chl a concentration. This study tested for CO2 sensitivities in primary production (PP of particulate organic carbon (PPPOC and of dissolved organic carbon (PPDOC. Therefore, 14C-bottle incubations (24 h of mesocosm samples were performed at 1 m depth receiving about 60% of incoming radiation. PP for all mesocosms averaged 8.06 ± 3.64 μmol C l−1 d−1 and was slightly higher than in the outside fjord system. Comparison between mesocosms revealed significantly higher PPPOC at elevated compared to low pCO2 after nutrient addition. PPDOC was significantly higher in CO2 enriched mesocosms before as well as after nutrient addition, suggesting that CO2 had a direct influence on DOC production. DOC concentrations inside the mesocosms increased before nutrient addition and more in high CO2 mesocosms. After addition of nutrients, however, further DOC accumulation was negligible and not significantly different between treatments, indicating rapid utilization of freshly produced DOC. Bacterial biomass production (BP was coupled to PP in all treatments, indicating that 3.5 ± 1.9% of PP, or 21.6 ± 12.5% of PPDOC provided sufficient carbon for synthesis of bacterial biomass. The response of 14C-based PP rates to CO2 enrichment was at odds with O2-based net community production (NCP rates that were also determined during this study, albeit at lower light level. We conclude that the enhanced release of labile DOC during autotrophic

  14. A sedimentologic and 14C dating study of five eastern Australian upper continental slope submarine landslides

    Science.gov (United States)

    Clarke, S. L.; Hubble, T.; Webster, J.; Airey, D.; De Carli, E.; Ferraz, C.; Reimer, P. J.; Boyd, R.; Keene, J.

    2013-12-01

    Sedimentologic and AMS 14C age data are reported for calcareous hemipelagic mud samples taken from gravity cores collected at sites within, or adjacent to five submarine landslides identified with multibeam bathymetry data on the Nerrang Plateau segment and surrounding canyons of eastern Australia's continental slope (Bribie Bowl, Coolangatta-2, Coolangatta-1, Cudgen and Byron). Sediments are comprised of mixtures of calcareous and terrigenous clay (10-20%), silt (50-65%) and sand (15-40%) and are generally uniform in appearance. Their carbonate contents vary between and 17% and 22% by weight while organic carbon contents are less than 10% by weight. Dating of conformably deposited material identified in ten of the twelve cores indicates a range of sediment accumulation rates between 0.017mka-1 and 0.2 mka-1 which are consistent with previous estimates reported for this area. One slide-adjacent core, and four within-landslide cores present depositional hiatus surfaces located at depths of 0.8 to 2.2 meters below the present-day seafloor and identified by a sharp, colour-change boundary; discernable but small increases in sediment stiffness; and a slight increase in sediment bulk density of 0.1 gcm-3. Distinct gaps in AMS 14C age of at least 20ka are recorded across these boundary surfaces. Examination of sub-bottom profiler records of transects through three of the within-slide core-sites and their nearby landslide scarps available for the Coolangatta-1 and Cudgen slides indicate that: 1) the youngest identifiable sediment layer reflectors upslope of these slides, terminate on and are truncated by slide rupture surfaces; and 2) there is no obvious evidence in the sub-bottom profiles for a post-slide sediment layer draped over or otherwise burying slide ruptures or exposed slide detachment surfaces. This suggests that both these submarine landslides are geologically recent and suggests that the hiatus surfaces identified in Coolangatta-1's and Cudgen's within

  15. Pharmacokinetics and excretion of 14C-bendamustine in patients with relapsed or refractory malignancy.

    Science.gov (United States)

    Dubbelman, Anne-Charlotte; Rosing, Hilde; Darwish, Mona; D'Andrea, Denise; Bond, Mary; Hellriegel, Edward; Robertson, Philmore; Beijnen, Jos H; Schellens, Jan H M

    2013-03-01

    Bendamustine is an alkylating agent with clinical activity against a variety of hematologic malignancies and solid tumors. To assess the roles of renal and hepatic drug elimination pathways in the excretion and metabolism of bendamustine, a mass balance study was performed in patients with relapsed or refractory malignancies. A single 60-minute intravenous dose of 120 mg/m(2), 80-95 μCi (14)C-bendamustine hydrochloride was administered to six patients, followed by collection of blood, urine, and fecal samples at specified time points up to day 8 or until the radioactivity of the 24-hour urine and fecal collections was below 1% of the administered dose (whichever was longer). Total radioactivity (TRA) was measured in all samples, and concentrations of unchanged bendamustine and its metabolites γ-hydroxy-bendamustine (M3), N-desmethyl-bendamustine (M4), and dihydroxy bendamustine (HP2) were determined in plasma and urine, using validated liquid chromatography-tandem mass spectrometry methods. The mean recovery of TRA in excreta was 76% of the radiochemical dose. Approximately half of the administered dose was recovered in urine and a quarter in feces. Less than 5% of the administered dose was recovered in urine as unchanged bendamustine. Bendamustine clearance from plasma was rapid, with a half-life of ~40 minutes. Plasma concentrations of M3, M4, and HP2 were very low relative to bendamustine concentrations. Plasma levels of TRA were higher and more sustained as compared with plasma concentrations of bendamustine, M3, M4, and HP2, suggesting the presence of one or more longer-lived (14)C-bendamustine-derived compounds. Fatigue (50%) and vomiting (50%) were the most frequent treatment-related adverse events. A grade 3/4 absolute lymphocyte count decrease occurred in all patients at some point during the study. Bendamustine is extensively metabolized, with subsequent excretion in both urine and feces. Accumulation of bendamustine is not anticipated in cancer

  16. MIN {sup 14}C UBT: A combination of gastric basal transit and {sup 14}C-urea breath test for the detection of helicobacter pylori infection in human beings

    Energy Technology Data Exchange (ETDEWEB)

    Zubillaga, M.; Oliveri, P.; Calcagno, M.L.; Goldman, C.; Caro, R.; Mitta, A.; Degrossi, O.; Boccio, J

    1997-08-01

    The purpose of this work is to demonstrate that the {sup 14}C-urea breath test (UBT) performed at different times combined with the study of the gastric basal transit, which evaluates the intragastric displacement of a labeled solution under fasting conditions, has the advantage of being representative of the whole stomach surface and constitutes a non-aggressive test for the detection of H. pylori. This test, which has been called MIN {sup 14}C UBT, is a modification of the conventional {sup 14}C UBT in which low volumes of a solution of {sup 14}C-urea together with {sup 99m}Tc-sulfur colloid are administered. The {sup 99m}Tc-sulfur colloid is not absorbed in the gastrointestinal tract and has the great advantage of allowing the 'visualization' of the transit of the {sup 14}C-urea within the gastrointestinal tract. This modification allows the simultaneous determination of the production of the {sup 14}CO{sub 2} and the place where this process occurs. The results show that there is a good correlation between the images obtained and the breath samples collected. We found that this test has a sensitivity of 98% and a specificity of 96% for H. pylori detection.

  17. Coprecipitation of {sup 14}C and Sr with carbonate precipitates: The importance of reaction kinetics and recrystallization pathways

    Energy Technology Data Exchange (ETDEWEB)

    Hodkin, David J. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Stewart, Douglas I. [School of Civil Engineering, University of Leeds (United Kingdom); Graham, James T. [National Nuclear Laboratory, Sellafield, Cumbria (United Kingdom); Burke, Ian T., E-mail: I.T.Burke@leeds.ac.uk [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2016-08-15

    This study investigated the simultaneous removal of Sr{sup 2+} and {sup 14}CO{sub 3}{sup 2−} from pH > 12 Ca(OH){sub 2} solution by the precipitation of calcium carbonate. Initial Ca{sup 2+}:CO{sub 3}{sup 2−} ratios ranged from 10:1 to 10:100 (mM:mM). Maximum removal of {sup 14}C and Sr{sup 2+} both occurred in the system containing 10 mM Ca{sup 2+} and 1 mM CO{sub 3}{sup 2−} (99.7% and 98.6% removal respectively). A kinetic model is provided that describes {sup 14}C and Sr removal in terms of mineral dissolution and precipitation reactions. The removal of {sup 14}C was achieved during the depletion of the initial TIC in solution, and was subsequently significantly affected by recrystallization of the calcite precipitate from an elongate to isotropic morphology. This liberated > 46% of the {sup 14}C back to solution. Sr{sup 2+} removal occurred as Ca{sup 2+} became depleted in solution and was not significantly affected by the recrystallization process. The proposed reaction could form the basis for low cost remediation scheme for {sup 90}Sr and {sup 14}C in radioactively contaminated waters (<$0.25 reagent cost per m{sup 3} treated). - Highlights: • 99.7% of {sup 14}C and 98.6% of Sr removed from aqueous solution by CaCO{sub 3} precipitation. • Remobilization of {sup 14}C observed during calcium carbonate recrystallization. • Sr displayed variable distribution coefficient (possibly affected by Ca:Sr ratio). • Reagent cost of $0.22/m{sup 3} of treated groundwater.

  18. The disposition and metabolism of /sup 14/C-tiaramide. HCl in man

    Energy Technology Data Exchange (ETDEWEB)

    Klunk, L.J.; Riska, P.S.; Maynard, D.E.

    The disposition and metabolism of /sup 14/C-tiaramide HCl was examined in four healthy male volunteers, after administration of a 200-mg dose in solution. The mean cumulative recovery of administered radioactivity was 91.3 +/- 2.9% (mean +/- SD) in urine an 6.0 +/- 1.5% in feces. The elimination was rapid, with 83.9% of the radioactivity extracted in urine in the first 12 hr. The unchanged tiaramide serum concentration curve showed monoexponential elimination with a half-life of 1.3 hr. Peak serum levels, of 1.6-2.2 micrograms/ml were attained between 0.5 and 1.5 hr after dosing. Tiaramide was extensively metabolized, with less than 1% excreted unchanged. Urinary metabolites (80-95% of the dose) were identified by mass-spectral comparison to authentic standards. Biotransformation resulted in production of the N-acetic acid N-oxide, N-acetic acid, O-glucuronide, N-oxide, and desethanol metabolites of tiaramide.

  19. Fate of {sup 14}C-triclocarban in biosolids-amended soils

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Elizabeth Hodges, E-mail: lizah@ufl.edu [Soil and Water Science Department, University of Florida, 408 Newell Hall, Gainesville, Florida, 32611 (United States); Department of Health Sciences, University of Alaska Anchorage, DPL 404, 3211 Providence Drive, Anchorage, AK 99508-4614 (United States); O' Connor, George A., E-mail: gao@ufl.edu [Soil and Water Science Department, P.O. Box 110510, University of Florida, Gainesville, FL 32611-01519 (United States); McAvoy, Drew C., E-mail: mcavoy.dc@pg.com [Environmental Safety Department, P.O. Box 538707, The Procter and Gamble Company, Cincinnati, OH, 45253-8707 (United States)

    2010-06-01

    Triclocarban (TCC) is an antibacterial compound commonly detected in biosolids at parts-per-million concentrations. Approximately half of the biosolids produced in the United States are land-applied, resulting in a systematic release of TCC into the soil environment. The extent of biosolids-borne TCC environmental transport and potential human/ecological exposures will be greatly affected by its bioavailability and the rate of degradation in amended soils. To investigate these factors, radiolabeled TCC ({sup 14}C-TCC) was incorporated into anaerobically digested biosolids, amended to two soils, and incubated under aerobic conditions. The evolution of {sup 14}CO2 (biodegradation) and changes in chemical extractability (bioavailability) was measured over time. Water extractable TCC over the study period was low and significantly decreased over the first 3 weeks of the study (from 14% to 4% in a fine sand soil and from 3 to < 1% in a silty clay loam soil). Mineralization (i.e. ultimate degradation), as measured by evolution of {sup 14}CO{sub 2}, was < 4% over 7.5 months. Methanol extracts of the amended soils were analyzed by radiolabel thin-layer chromatography (RAD-TLC), but no intermediate degradation products were detected. Approximately 20% and 50% of the radioactivity in the amended fine sand and silty clay loam soils, respectively, was converted to bound residue as measured by solids combustion. These results indicate that biosolids-borne TCC becomes less bioavailable over time and biodegrades at a very slow rate.

  20. Current perspectives of {sup 14}C-isotope measurement in biomedical accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lappin, Graham; Garner, R.Colin [Xceleron Ltd, York Biocentre, Innovation Way, YO10 5NY, York (United Kingdom)

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched {sup 14}C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided. (orig.)

  1. Degradation of [(14)C]carfentrazone-ethyl under aerobic aquatic conditions.

    Science.gov (United States)

    Elmarakby, S A; Supplee, D; Cook, R

    2001-11-01

    Carfentrazone-ethyl (CF-E) is an aryl triazolinone reduced-risk herbicide for use on corn, wheat, and soybean. As part of the assessment of its metabolic fate, the aerobic aquatic metabolism of [(14)C]CF-E at a concentration of 0.22 microg/g was investigated. Two separate aquatic sediments (silty clay loam and clay loam soils, flooded with water) were used in the study. At each of eight samplings throughout the 30-day study, the distribution of radioactivity between surface water, sediment, and volatile fractions was assessed. At zero time, the majority of the applied radioactivity was contained in the water layer (83-90%), declining to 70-80% after 30 days. This was coupled with an increase in the percent radioactivity in the soil layer from 4-6% at day 0 to 13-19% after 30 days. Nonextractable soil residues and volatile degradation products were formed in negligible amounts. Analysis of the incubation extracts from either aquatic sediment indicated a rapid conversion (90% of the applied radioactivity were formed. Identification of these degradation products was initially achieved through chromatographic comparison with reference synthetic standards and subsequently confirmed using LC-MS analysis. A degradation pathway for CF-E under aerobic aquatic conditions is proposed.

  2. Flunixin residues in milk after intravenous treatment of dairy cattle with (14)C-flunixin.

    Science.gov (United States)

    Feely, William F; Chester-Yansen, Cheryl; Thompson, Kenneth; Campbell, John W; Boner, Pamela L; Liu, David D W; Crouch, Louis S

    2002-12-04

    Flunixin meglumine is used in veterinary medicine as an alternative to narcotic analgesics and as an antiinflammatory agent. Eight Holstein dairy cows were dosed intravenously once daily on three consecutive days with (14)C-flunixin meglumine at approximately 2.2 mg of flunixin free acid/kg of body weight. Milk was collected twice daily to determine the decline of the total radioactive residues (TRR) in milk and to identify or characterize residue components. TRR in milk declined rapidly and averaged 66, 20, and 14 ppb, respectively, for the first, second, and third milkings after administration of the last dose. Milk was extracted, and the extracts were examined for radioactive residues. Mean extractability of milk TRR was always greater than 80%. Flunixin and 5-hydroxyflunixin were identified by coelution with analytical standards using reverse phase HPLC. These two residues were the main radioactive residues found in milk and together accounted for 64, 37, and 44% of the extractable residues, for the first, second, and third milkings, respectively, after administration of the last dose. The presence of 5-OH flunixin in milk was confirmed by HPLC/MS/MS.

  3. Accumulation of {sup 14}C-trinitrotoluene and related nonextractable (bound) residues in Eisenia fetida

    Energy Technology Data Exchange (ETDEWEB)

    Belden, Jason B., E-mail: jbelden@okstate.edu [Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (United States); Lotufo, Guillerme R. [US Army Engineer Research and Development Center, Vicksburg, MS 39180 (United States); Chambliss, C. Kevin [Department of Chemistry, Baylor University, Waco, TX 76798 (United States); Fisher, Jonathan C. [Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (United States); Johnson, Dave R.; Boyd, Robert E.; Sims, Jerre G. [US Army Engineer Research and Development Center, Vicksburg, MS 39180 (United States)

    2011-05-15

    To determine if trinitrotoluene (TNT) forms nonextractable residues in earthworms and to measure the relative degree of accumulation as compared to TNT and its deaminated metabolites, Eisenia fetida was exposed to {sup 14}C-TNT using dermal contact to filter paper or exposure to soil. Nonextractable residues made up 32-68% of total body burden depending on exposure media and depuration time. Parent TNT accounted for less than 3% of radioactivity, while ADNTs accounted for 7-38%. Elimination half-lives were 61-120 h for TNT, ADNTs, and DANTs, which was significantly lower than the half-lives found for nonextractable residues, 201-240 h. However, over 80% of the nonextractable residue was solubilized using weak acid (pH 2). Based on our findings that TNT accumulation occurs primarily as nonextractable residues, which have a longer half-life, and that nonextractable residues can be solubilized, we propose that nonextractable residues could be used as a selective biomarker for assessing TNT contamination. - Highlights: > Trinitrotoluene accumulation in earthworms primarily occurs as nonextractable residues. > Nonextractable residues have a significantly longer half life in the worm as compared to TNT and its solvent-extractable deaminated metabolites. > Nonextractable residue may be useful as a biomarker for exposure to TNT. - The majority of trinitrotoluene accumulation in earthworms occurs as nonextractable residues that have a significantly longer half life in the worm as compared to TNT and its solvent-extractable deaminated metabolites.

  4. A New Look at 29Al and 27Mg from the 18O + 14C Reaction

    Science.gov (United States)

    Tabor, Samuel; Dungan, Rutger; Volya, Alexander; Tripathi, Vandana; Abromeit, Brittany; Caussyn, David; Kravvaris, Konstantinos; Lubna, Rebeka; Tai, Pei-Luan

    2016-09-01

    It was possible to compare moderately high-spin states in a nearby pair of odd proton and odd neutron s-d shell nuclei by observing proton-gamma-gamma or alpha-gamma-gamma coincidences, respectively, following the fusion of long-lived radioactive 14C with neutron-rich 18O at a beam energy of 40 MeV using the FSU gamma detector array with digital data acquisition. Eight new states were seen in 29Al, all of which decay directly or indirectly to the 9/2 + level, the highest previously known spin in 29Al. Some of the new states form a very likely yrast M1 decay sequence from (15/2 +) down to the 5/2 + ground state. The new states are relatively well described by pure s-d shell model calculations using the USDA interaction. By contrast the 4 new states found in 27Mg are divided between positive and negative parities reaching up to (13/2 +) and (11/2-). Radiative decays of neutron unbound states in 27Mg will be discussed. Supported in part by NSF Grant No. 1401574.

  5. The uptake and distribution of 14-C-mescaline in different organs of developing rat.

    Science.gov (United States)

    Shah, N S; Shah, K R; Lawrence, R S; Neely, A E

    1975-01-01

    Rats of 1,4,8,12,20, and 60 days postnatal age were injected ip with 14-C-mescaline (50 nCi/g). The levels of mescaline and its deaminated metabolite, 3,4,5-trimethoxyphenylacetic acid, were examined in the brain, liver, heart, spleen, lung, and kidney at 30, 60, 90, and 120 min. Mescaline was rapidly taken up by all the organs examined. In general, the organs of younger rats accumulated much larger amounts than those of adult animals. Brain concentrated the lowest amounts in comparison with other tissues. In the brain, the uptake was the highest in 1-day-old rats and decreased with age. The disappearance of mescaline in various organs was comparatively slower in younger animals than in 20-day or older rats. Rats immediately after birth and uptake was the highest in 1-day-old rats and decreased with age. The disappearance of mescaline in various organs was comparatively slower in younger animals than in 20-day or older rats. Rats immediately after birth and up to 20 days of age metabolized mescaline less efficiently than adults. From the data, it appears that the blood-brain barrier for mescaline develops gradually with age but is not completely impermeable in adults.

  6. Pharmacokinetics, distribution, metabolism, and excretion of the dual reuptake inhibitor [(14)C]-nefopam in rats.

    Science.gov (United States)

    Yu, Jian; Solon, Eric; Shen, Helen; Modi, Nishit B; Mittur, Aravind

    2016-11-01

    1. This study examined the pharmacokinetics, distribution, metabolism, and excretion of [(14)C] nefopam in rats after a single oral administration. Blood, plasma, and excreta were analyzed for total radioactivity, nefopam, and metabolites. Metabolites were profiled and identified. Radioactivity distribution was determined by quantitative whole-body autoradiography. 2. The pharmacokinetic profiles of total radioactivity and nefopam were similar in male and female rats. Radioactivity partitioned approximately equally between plasma and red blood cells. A majority of the radioactivity was excreted in urine within 24 hours and mass balance was achieved within 7 days. 3. Intact nefopam was a minor component in plasma and excreta. Numerous metabolites were identified in plasma and urine generated by multiple pathways including: hydroxylation/oxidation metabolites (M11, M22a and M22b, M16, M20), some of which were further glucuronidated (M6a to M6c, M7a to M7c, M8a and M8b, M3a to M3d); N-demethylation of nefopam to metabolite M21, which additionally undergoes single or multiple hydroxylations or sulfation (M9, M14, M23), with some of the hydroxylated metabolites further glucuronidated (M2a to M2d). 4. Total radioactivity rapidly distributed with highest concentrations found in the urinary bladder, stomach, liver, kidney medulla, small intestine, uveal tract, and kidney cortex without significant accumulation or persistence. Radioactivity reversibly associated with melanin-containing tissues.

  7. Measurement of activity for S-adenosylmethionine decarboxylase using radioisotope {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kyong Cheol; Park, Sang Hyun [Radiation Research Center for Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kamio, Yoshiyuku [Division of Bioscience and Biotechnology for Future Bioindustries, Graduate School of Agricultural Science, Tohoku University (Japan)

    2007-05-15

    Polyamines are essential for normal cell growth and have important physiological function. They are polycationic compounds that are present in all biological materials. Also, they have been implicated in a wide variety of biological reactions. Generally, putrescine and spermidine are contained high amount in prokaryote, but spermidine and spermine are in eukaryote, respectively. However, S. ruminantium cells contain the polyamins such as spermidine and spermine. Addition of an aminopropyl group to putrescine conducts to the synthesis of spermidine. Aminopropyl group is derived from the dcSAM, a decarboxylation of S-adenosylmethionine, through action of S-adenosylmethionine decarboxylase (SAMDC). We suggested that S. ruminantium has a different pathway compare with prokaryote for polyamine synthesis. Assay for SAMDC activity was used {sup 14}C labeled substrate. Key enzyme in the biosynthesis of polyamines, SAMDC, was purified from S. ruminantium and characterized. The enzyme was purified about 1,259-fold to electrophoretic homogeneity with a specific activity of 1.89×10{sup -5} kat kg'-{sup 1} of protein.

  8. AMS {sup 14}C dating of early Anasazi petroglyphs from the North American southwest desert region

    Energy Technology Data Exchange (ETDEWEB)

    Beck, W.; Donahue, D.; Burr, G.; Jull, A.J.T. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics

    1997-12-31

    Full text: Since it was first developed in the early 1980`s, direct dating of rock surfaces by AMS radiocarbon analysis has become an integral tool in the fields of geomorphology and archaeology. Recently, the AMS Laboratory at the University of Arizona has become directly involved in a series of measurements in an attempt to determine the age of the petroglyphs found in the Petrified Forest region of NE Arizona, in the American Southwest. There are several generations of these petroglyphs, the most recent of these have been ascribed to the so-called Pueblo Indians which lived in this region between 700-1450 AD. Three earlier epochs of petroglyph makers also inhabited this region which have been grouped into the Basketmaker, Archaic, and Paleo-Indian periods. This original focus of this study was an attempt to identify the timing of development of the Paleo-Indian and Archaic Indian styles of petroglyphs from this region using AMS {sup 14}C measurements. Microscopic examination of samples from these petroglyphs, showed that the samples contained two types of black, carbon-rich materials with distinctly different visual properties. Detailed examination of these particles reveal that one type strongly resembles finely ground bituminous coal, whereas the other strongly resembles ground pyrolized wood. Subsequent measurements of the radiocarbon contents of separated fractions of the two types of materials have shown that they have widely differing radiocarbon ages. In such cases, the radiocarbon age of the entire sample would yield results which are, at best, ambiguous.

  9. Introducing the global carbon cycle to middle school students with a 14C research project

    Science.gov (United States)

    Brodman Larson, L.; Phillips, C. L.; LaFranchi, B. W.

    2012-12-01

    Global Climate Change (GCC) is currently not part of the California Science Standards for 7th grade. Required course elements, however, such as the carbon cycle, photosynthesis, and cellular respiration could be linked to global climate change. Here we present a lesson plan developed in collaboration with scientists from Lawrence Livermore National Laboratory, to involve 7th grade students in monitoring of fossil fuel emissions in the Richmond/San Pablo area of California. -The lesson plan is a Greenhouse Gas/Global Climate Change Unit, with an embedded research project in which students will collect plant samples from various locals for analysis of 14C, to determine if there is a correlation between location and how much CO2 is coming from fossil fuel combustion. Main learning objectives are for students to: 1) understand how fossil fuel emissions impact the global carbon cycle, 2) understand how scientists estimate fossil CO2 emissions, and 3) engage in hypothesis development and testing. This project also engages students in active science learning and helps to develop responsibility, two key factors for adolescentsWe expect to see a correlation between proximity to freeways and levels of fossil fuel emissions. This unit will introduce important GCC concepts to students at a younger age, and increase their knowledge about fossil fuel emissions in their local environment, as well as the regional and global impacts of fossil emissions.

  10. Cerebral correlates of depressed behavior in rats, visualized using /sup 14/C-2-deoxyglucose autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Caldecott-Hazard, S.; Mazziotta, J.; Phelps, M.

    1988-06-01

    /sup 14/C-2-Deoxyglucose (2DG) was used to investigate changes in the rate of cerebral metabolism in 3 rat models of depressed behavior. The models had already been established in the literature and were induced by injections of alpha-methyl-para-tyrosine, withdrawal from chronic amphetamine, or stress. We verified that exploratory behaviors were depressed in each model and that an antidepressant drug, tranylcypromine, prevented the depressed behavior in each model. 2DG studies revealed that the rate of regional glucose metabolism was elevated bilaterally in the lateral habenula of each of the 3 models. Regional metabolic rates were reduced in each model in the dorsal medial prefrontal cortex, anterior ventral nucleus of the thalamus, and inferior colliculus. Forebrain global metabolic rates were also reduced in each of the models. Tranylcypromine prevented the elevated rate of lateral habenula metabolism seen in each of the models alone but did not significantly affect the rates of global metabolism. Our findings of identical metabolic changes in each of the models indicate that these changes are not idiosyncratic to a particular model; rather, they correlate with a generalizable state of depressed exploratory behavior in rats.

  11. Accuracy of the {sup 14} C-urea breath test for the diagnosis of Helicobacter pylori