bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative stress and changes in adenosine deaminase activity of cattle experimentally infected byFasciola hepatica
Authors: DA SILVA ALEKSANDRO S. , BALDISSERA MATHEUS D. , BOTTARI NATHIELI B. , GABRIEL MATHEUS E. , RHODEN LEANDRO A. , PIVA MANOELA M. , CHRIST RICARDO , STEDILLE FERNANDA A. , GRIS ANDERSON , MORSCH VERA M. , SCHETINGER MARIA ROSA , MENDES RICARDO E.
Published: January 2017

The aim of this study was to evaluate the oxidative stress in serum and liver and adenosine deaminase (ADA) activity of cattle experimentally infected byFasciola hepatica. The group A consisted of five healthy animals (uninfected), and the group B was composed of five animals orally infected with 200 metacercariae ofF. hepatica.On days 20, 40, 60 and 80 post-infection (PI) serum was collected to measure oxidative stress variables. On day 100 PI, animals were humanely euthanized and liver samples were collected. Infected animals showed lower (P< 0·05) seric ADA activities on days 40 and 60 PI but higher (P< 0·05) in the liver tissue compared with uninfected animals. Seric and hepatic reactive oxygen species (ROS) were higher (P< 0·05) in infected compared with uninfected animals. Hepatic thiobarbituric acid reactive substances were higher (P< 0·05) in infected animals. Catalase and glutathioneS-transferase activities were lower in liver tissue of infected animals, while glutathione peroxidase was higher compared with uninfected (P< 0·05). In summary, we conclude that oxidative stress occurs in cattle experimentally infected byF. hepatica, mainly due to excessive ROS production in the course of fasciolosis, contributing to hepatic damage, and that increased in hepatic ADA activity may contribute to the inflammatory process.
Freshwater Reservoir Effect Variability in Northern Germany
Authors: Philippsen Bente , Heinemeier Jan
Published: January 2017

The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating of freshwater-based samples requires knowing the order of magnitude of the reservoir effect and its degree of variability. Measurements on modern riverine materials may not give a single reservoir age correction that can be applied to archaeological samples, but they show the order of magnitude and variability that can also be expected for the past. This knowledge will be applied to the dating of food crusts on pottery from the Mesolithic sites Kayhude at the Alster River and Schlamersdorf at the Trave River, both in Schleswig-Holstein, northern Germany.
A Freshwater Lake Saga: Carbon Routing Within the Aquatic Food Web of Lake Schwerin
Authors: Fernandes Ricardo , Dreves Alexander , Nadeau Marie-Josée , Grootes Pieter M
Published: January 2017

Recently, several case studies have demonstrated the presence of human radiocarbon dietary reservoir effects in inland contexts. Freshwater reservoir effects present a high degree of variability, making it difficult to define local reservoir effect reference values necessary for correcting chronologies based on14C dating of human bone material. Here, we investigate the hypothesis that14C ages of edible freshwater species are delimited by the14C ages of the main water carbon pools (DIC, POC, and DOC).

Water, plant, algae, bivalve, and fish samples were collected from lakes Schwerin and Ostorf (Germany).14C and isotopic measurements were performed on the floral and faunal species and on water DIC, POC, and DOC. The results demonstrate the potential of the study area for large and variable freshwater reservoir effects. In the case of Lake Schwerin, the working hypothesis was verified as the14C ages of faunal and floral species were delimited by the14C ages of water DIC and POC, probably associated with 2 extreme categories of food chains (grazing and detritus). While the results obtained confirm the working hypothesis and suggest a relatively straightforward interpretation, further research is necessary to investigate possible spatial and seasonal variations.
Marine Radiocarbon Reservoir Effect in Southern Atlantic Iberian Coast
Authors: Martins José M Matos , Soares António M Monge
Published: January 2017

Research concerning the variability of the marine radiocarbon reservoir effect (ΔR) in the southern Iberian Atlantic coast confirms the existence of different ΔR values for regions that correspond to different oceanographic conditions. Due to these oceanographic conditions, the southern Iberian Atlantic coast can be divided into 3 zones: the Barlavento (windward), where the coastal waters are influenced by an intense upwelling of the northeastern Atlantic circulation (positive ΔR values); the Sotavento (leeward), where an upwelling area of minor intensity occurs; and the Andalusian coast, where because of its configuration does not present any wind-driven coastal upwelling (negative ΔR values). For the first time, ΔR values were determined for the Sotavento coastal region and, at the same time, new ΔR values were calculated for the Barlavento and the Andalusian coast for the last 3000 yr taking into account the data already obtained but now using a new methodology for calculation. In this way, ΔR weighted mean values were determined for the 3 regions of the southern Iberian Atlantic coast: ΔR = +69 ± 17 14C yr (Barlavento), ΔR = −26 ± 14 14C yr (Sotavento), and ΔR = −108 ± 31 14C yr (Andalusian coast). These values are in accordance with the different oceanographic conditions prevailing in these coastal regions. The data also allow identification of a Bond event at 0.8 ka cal BP and a drastic change in the oceanographic conditions in the Barlavento and Andalusian coastal areas during the 5th millennium cal BP.
14C Dating of Organic Residue and Carbonate from Stromatolites in Etosha Pan, Namibia: 14C Reservoir Effect, Correction of Published Ages, and Evidence of >8-m-Deep Lake During the Late Pleistocene
Authors: Brook George A , Cherkinsky A , Railsback L Bruce , Marais Eugene , Hipondoka Martin H T
Published: January 2017

Lacustrine stromatolites are layered accretionary structures formed in shallow water by cyanobacteria. They are a precise indicator of high lake limits and their morphology and structure provide an insight into paleoenvironments of the time. Previous research on lacustrine stromatolites from Etosha Pan in Namibia based on radiocarbon ages of carbonates were close to the limit of the method and did not account for any possible 14C reservoir effect. The ages were used to suggest that the basin was not extensively flooded during the last 40,000 yr. To assess the reservoir effect, the age characteristics of a stromatolite from Poacher's Point were investigated by 14C dating both carbonate and organic residue from samples at different depths in the deposit. The ∼15-cm-diameter stromatolite was separated into 12 zones from the center to the edge and block samples were cut from each zone; the carbonate and residual organic residue were dated separately. The carbonate ages ranged from 34,700 to 24,700 14C yr BP and the organic ages from 15,700 to 2500 14C yr BP. Ages generally increased with increasing distance from the surface of the deposit. We believe that the organic ages are an accurate estimate of the stromatolite's age, while the much older carbonate ages reflect incorporation of old carbon from limestone bedrock and ancient calcrete introduced by stream and spring flow. Excluding the 2 oldest organic ages (15,700 and 13,600 14C yr BP), which may reflect contamination by older organic material washed into the lake during flooding, a linear regression relationship between carbonate and organic ages indicates that the reservoir effect on carbonate ranges up to ∼24,000 14C yr BP but decreases slightly as the true age of the deposit increases. This regression relationship was used to correct 2 finite carbonate ages for stromatolites from Pelican Island obtained in the early 1980s, which together with our new organic age for a stromatolite from Andoni Bay, document a >8-m-deep lake in Etosha Pan during the Late Pleistocene, at and prior to ∼34,000–26,000 cal yr BP. The organic carbon ages from the Poacher's Point stromatolite suggest prolonged lacustrine conditions during the early to middle Holocene (8000–6600 cal yr BP) but not to the extent seen during the Late Pleistocene.
Small Sambaquis and Big Chronologies: Shellmound Building and Hunter-Gatherers in Neotropical Highlands
Authors: Figuti Levy , Plens Cláudia R , DeBlasis Paulo
Published: January 2017

Sambaquis, famous Brazilian coastal shellmounds, represent a successful and long archaeological cultural tradition, with hundreds of sites spread over 2000 km of the Brazilian south-southeast coastline. These sites have many burials within a sequence of layers comprising a mix of faunal remains, charcoal, ashes, and sand, thus resulting in very complex stratigraphic structures. Several radiocarbon samples exhibit ages between 8000 and 1000 cal yr BP. In the Brazilian southeastern coastal hinterland, at the Ribeira de Iguape basin, 36 small mounds similar to the sambaquis were found, composed mostly of landsnail shells, bone remains of terrestrial fauna, lithic and osteodontological artifacts, and quite a few burials. Through the last decade an archaeological research project has accomplished extensive surveys and systematic 14C sampling, together with excavations in selected sites. A sequence of ages has been obtained from different samples (16 on shell, 10 on human bone, and 6 on charcoal) representing 19 sites. These dates range from 10,000 to 1000 cal yr BP, highlighting around 9000 yr of cultural continuity, contemporary to both the Paleoindian record over the hinterland plateau, and older than their coastal counterparts, the sambaquis. By presenting the 14C distribution and an overview of the archaeological features of these sites, we discuss briefly the dispersion and settlement processes of early peopling in this area of Brazil.
14C Dating of “Brandgrubengräber” from the Bronze Age to the Roman Period in Western Flanders (Belgium)
Authors: De Mulder Guy , van Strydonck Mark , De Clercq Wim
Published: January 2017

A Brandgrubengrab entails a specific way of depositing human remains whereby the cremated remains of the deceased and other remnants of the funeral pyre, such as charcoal and burnt objects, are jointly deposited onto the bottom of a pit. This type of burial became increasingly popular during the Late Iron Age and the Roman period, when it was the main basic funerary structure used in western Flanders. In recent years, more attention has been paid to establishing a more precise chronology for these funerary structures by applying radiocarbon dating. A set of 40 14C dates obtained from samples originating from small cemeteries and isolated cremations now offers new insights in the development of this specific cremation burial ritual.
Stones, Bones, and Hillfort: Radiocarbon Dating of ķivutkalns Bronze-Working Center
Authors: Oinonen M , Vasks A , Zarina G , Lavento M
Published: January 2017

The Bronze Age site of ķivutkalns with its massive amount of archaeological artifacts and human remains is considered the largest bronze-working center in Latvia. The site is a unique combination of cemetery and hillfort believed to be built on top of each other. This work presents new radiocarbon dates on human and animal bone collagen that somewhat challenge this interpretation. Based on analyses using a Bayesian modeling framework, the present data suggest overlapping calendar year distributions for the contexts within the 1st millennium BC. The carbon and nitrogen isotopic ratios indicate mainly terrestrial dietary habits of studied individuals and nuclear family remains buried in one of the graves. The older charcoal data may be subject to the old-wood effect and the results are partly limited by the limited amount of data and the 14C calibration curve plateau of the 1st millennium BC. Therefore, the ultimate conclusions on contemporaneity of the cemetery and hillfort need to wait for further analyses on the massive amounts of bone material.
14C AMS Dating of Wooden Cores from Historic Buildings for Archaeological and Dendrochronological Research in High Asia
Authors: Scharf A , Bräuning A , Kretschmer W , Wegner B , Darragon F
Published: January 2017

We had the opportunity to collect valuable wooden core samples from historic monasteries, temples, and secular buildings in 4 regions of High Asia, namely Dolpo (Nepal), ancient Nyangpo, Gyalrong/Minyag, and Lhasa and surroundings (all on the Tibetan Plateau, China). Tree species collected for dating include Pinus wallichiana (Dolpo), Juniperus tibetica, Pinus densata and several species of the genera Picea (spruce), Larix (larch), and Abies (fir) on the Tibetan Plateau, which could not always be determined to the species level due to the parallel occurrence of species of the same genus in these regions. Some of the wood samples were successfully dendro-dated with local tree-ring chronologies, but many could not, indicating a potentially higher age than the existing local chronologies. By accelerator mass spectrometry (AMS) dating and wiggle-matching 199 14C samples from 73 collected timbers, it was possible to date these wood samples with high precision, and important information about the possible time of construction of these important historic buildings was obtained for the first time. Floating chronologies of 14C-dated wood span the periods AD 650 to 900 in Dolpo and ∼200 BC to AD 420 on the Tibetan Plateau. Besides dating of the wood samples from these historic monuments, 14C AMS dating with wiggle-matching gives the opportunity to extend the range of the currently existing regional tree-ring chronologies for future environmental reconstructions on the Tibetan Plateau and the Himalayas.
Radiocarbon Dating of Ancient Canoes from Guangxi, China
Authors: Guan Yongjing , Ruan Xiangdong , Xiong Zhaoming , Wang Huijuan , Terrasi Filippo
Published: January 2017

Several canoes were excavated from coastal rivers in the Guangxi Zhuang Autonomous Region, southwest China. In order to confirm the age of the canoes, 6 samples were selected for radiocarbon dating from 3 canoes. The mean value of canoe NLJ was 365 ± 35 BP, and 2 samples from canoes MLJ and DFJ were 520 ± 21 and 499 ± 33 BP, respectively. The calendar ages cover a period from AD 1328 to 1641 at the 95% confidence level. These results disagree with previous studies that suggested canoes were only used over 1000 yr ago in China. We discuss the possible reasons for the results being younger than expected.
The Ocean Bomb Radiocarbon Inventory Revisited
Authors: Mouchet Anne
Published: January 2017

Large discrepancies exist among data-based estimates and model reconstructions of the ocean bomb radiocarbon inventory. In order to resolve this gap, it has been proposed that the CO2 piston velocity should be revised downward (Sweeney et al. 2007; Müller et al. 2008). This article compares the transient 14C distributions in the ocean obtained with different formulations of the isotopic ratio commonly used in modeling studies. It is found that both the CO2 increase and the air-sea CO2 flux significantly contribute to the 1990 ocean bomb 14C inventory, by around 10% each. Moreover, these 2 processes explain more than 25% of the inventory difference between 1974 and 1990. These results imply that, as already argued by Naegler (2009), inventories based on observations that lack information about CO2 invasion are underestimated. Further, this work provides insight into the reasons for discrepancies among model results. It suggests that while a comprehensive isotopic formulation is needed when addressing the global 14C cycle, a simplified form is more relevant for model calibration and piston velocity assessment based on currently available bomb 14C inventories.
Extraneous Carbon Assessments in Radiocarbon Measurements of Black Carbon in Environmental Matrices
Authors: Coppola Alysha I , Ziolkowski Lori A , Druffel Ellen R M
Published: January 2017

Extraneous carbon (Cex) added during chemical processing and isolation of black carbon (BC) in environmental matrices was quantified to assess its impact on compound specific radiocarbon analysis (CSRA). Extraneous carbon is added during the multiple steps of BC extraction, such as incomplete removal of solvents, and carbon bleed from the gas chromatographic and cation columns. We use 2 methods to evaluate the size and Δ14C values of Cex in BC in ocean sediments that require additional pretreatment using a cation column with the benzene polycarboxylic acid (BPCA) method. First, the direct method evaluates the size and Δ14C value of Cex directly from the process blank, generated by processing initially empty vials through the entire method identically to the treatment of a sample. Second, the indirect method quantifies Cex as the difference between processed and unprocessed (bulk) Δ14C values in a variety of modern and 14C-free or “dead” BC standards. Considering a suite of hypothetical marine sedimentary samples of various sizes and Δ14C values and BC Ring Trial standards, we compare both methods of corrections and find agreement between samples that are >50 μg C. Because Cex can profoundly influence the measured Δ14C value of compound specific samples, we strongly advocate the use of multiple types of process standards that match the sample size to assess Cex and investigate corrections throughout extensive sample processing.
Late Pleistocene and Holocene Vegetation, Climate Dynamics, and Amazonian Taxa in the Atlantic Forest, Linhares, SE Brazil
Authors: Buso Junior Antonio Alvaro , Ruiz Pessenda Luiz Carlos , de Oliveira Paulo Eduardo , Fonseca Giannini Paulo César , Lisboa Cohen Marcelo Cancela , Volkmer-Ribeiro Cecília , de Oliveira Sonia Maria Barros , De Fátima Rossetti Dilce , Lorente Flávio Lima , Borotti Filho Marcos Antonio , Schiavo Jolimar Antonio , Bendassolli José Albertino , França Marlon Carlos , Felix Guimarães José Tasso , Siqueira Geovane Souza
Published: January 2017

Analysis of biological proxies in lake sediment and geochemical analysis of soil profiles reveal natural vegetation dynamics, with climate inferences, since the late Pleistocene in a fragment of the pristine lowland Atlantic Forest of southeastern Brazil. Carbon isotopes from soil organic matter and 14C ages from the humin fraction indicate the dominance of C3 plants since ∼17,000 cal BP. Palynological analysis of a sediment core indicates the presence of Atlantic Forest vegetation since 7700 cal BP. Changes in the relative abundance of tree ferns and palms suggest the predominance of a humid period from ∼7000–4000 cal BP and establishment of the modern seasonal climate at ∼4000 cal BP. Data indicate maintenance of the regional forest coverage since the late Pleistocene, corroborating previous suggestions that this region was a forest refuge during less humid periods of the late Pleistocene and Holocene. Some plant taxa with currently divided distributions between Amazonia and the Atlantic Forest colonized the region since at least 7500 cal BP, indicating an earlier connection between Amazonia and Atlantic Forest.
Dating Recent Peat Accumulation in European Ombrotrophic Bogs
Authors: van der Plicht Johannes , Yeloff Dan , van der Linden Marjolein , van Geel Bas , Brain Sally , Chambers Frank M , Webb Julia , Toms Phillip
Published: January 2017

This study compares age estimates of recent peat deposits in 10 European ombrotrophic (precipitation-fed) bogs produced using the 14C bomb peak, 210Pb, 137Cs, spheroidal carbonaceous particles (SCPs), and pollen. At 3 sites, the results of the different dating methods agree well. In 5 cores, there is a clear discrepancy between the 14C bomb peak and 210Pb age estimates. In the upper layers of the profiles, the age estimates of 14C and 210Pb are in agreement. However, with increasing depth, the difference between the age estimates appears to become progressively greater. The evidence from the sites featured in the study suggests that, provided aboveground plant material (seeds, leaves) is selected for dating, the 14C bomb peak is a reliable dating method, and is not significantly affected by the incorporation of old carbon with low 14C content originating from sources including air pollution deposition or methane produced by peat decomposition. 210Pb age estimates that are too old may be explained by the enrichment of 210Pb activity in the surface layers of peat resulting from a hypothesized mechanism where rapidly infilling hollows, rich in binding sites, may scavenge 210Pb associated with dissolved organic matter passing through the hollow, as part of the surface drainage network. Until further research identifies and resolves the cause of the inaccuracy in 210Pb dating, age estimates of peat samples based only on 210Pb should be used with caution.
14C and 10Be in Dust Deposited During the Storm of 16–17 April 2006 in Beijing
Authors: Shen C D , Yi W X , Ding P , Liu K X , Xu X M
Published: January 2017

The concentrations of 10Be and 14C and values of δ13C in samples collected during a major dust storm in Beijing on 16–17 April 2006 were studied. The 10Be concentrations ranged from 1.69 × 108 to 2.07 × 108 atom/g, 14C ages for black carbon (BC) ranged from 3001 to 5181 yr BP and for total inorganic carbon (TIC) from 8464 to 9119 yr BP, and δ13C values for BC ranged from -23.15% to -23.80% and for TIC from -5.39% to -5.98%. A comparison of BC content and δ13C value between the dust, surface soil in the dust source region, and aerosols in Beijing indicated that BC in the dust deposited in Beijing is significantly incorporated by aerosol BC during the dust transportation. Based on the 14C ages of BC, the proportion of fossil-fuel-derived BC was 0.35–0.49 of the total. In contrast to BC, the TIC deposited in Beijing can be firmly related to the source area and δ13C was not significantly modified during its transportation. According to the 14C ages of TIC, the proportion of the secondary carbonate in the dust was from 0.63 to 0.70. The results confirm that 14C of TIC is another useful tracer to indicate the source region of dust besides the content and δ13C value of TIC from the arid and semi-arid regions of China.
A Study of KF3− Attenuation in an RFQ Gas Cell for 41Ca AMS
Authors: Zhao X-L , Litherland A E , Eliades J , Fu Y-C , Kieser W E
Published: January 2017

Guided by simulations using SIMION 8.1, a series of modifications were made to an experimental version of an Isobar Separator for Anions (ISA). The resulting improved version of the ISA provides a means of re-energizing the ions after they are cooled by gas collisions as they pass through the gas-filled radiofrequency quadrupoles (RFQ), and also provides higher transmission efficiencies. Reinvestigation of the separation of CaF3− and KF3− with this refined apparatus resulted in a better balance between isobar suppression and analyte transmission. KF3− was attenuated at eV energies by 4 orders of magnitude while 40% transmission of CaF3− was retained, for a 20keV CaF3− beam of Φ2mm and ±12mr. These results advance the possibility of an efficient small ISA-AMS system for both cosmogenic and medical applications of 41Ca.
Microgram-Level Radiocarbon Determination of Carbonaceous Particles in Firn and Ice Samples: Pretreatment and OC/EC Separation
Authors: Cao Fang , Zhang Yan-Lin , Szidat Sönke , Zapf Alexander , Wacker Lukas , Schwikowski Margit
Published: January 2017

Carbonaceous particles that comprise organic carbon (OC) and elemental carbon (EC) are of increasing interest in climate research because of their influence on the radiation balance of the Earth. The radiocarbon determination of particulate OC and EC extracted from ice cores provides a powerful tool to reconstruct the long-term natural and anthropogenic emissions of carbonaceous particles. However, this 14C-based source apportionment method has not been applied for the firn section, which is the uppermost part of Alpine glaciers with a typical thickness of up to 50 m. In contrast to glacier ice, firn samples are more easily contaminated through drilling and handling operations. In this study, an alternative decontamination method for firn samples consisting of chiselling off the outer parts instead of rinsing them was developed and verified. The obtained procedural blank of 2.8 ± 0.8 μg C for OC is a factor of 2 higher compared to the rinsing method used for ice, but still relatively low compared to the typical OC concentration in firn samples from Alpine glaciers. The EC blank of 0.3 ± 0.1 μg C is similar for both methods. For separation of OC and EC for subsequent 14C analysis, a thermal-optical method instead of the purely thermal method was applied for the first time to firn and ice samples, resulting in a reduced uncertainty of both the mass and 14C determination. OC and EC concentrations as well as their corresponding fraction of modern for firn and ice samples from Fiescherhorn and Jungfraujoch agree well with published results, validating the new method.
Processing of CO2 Samples Collected Using Zeolite Molecular Sieve for 14C Analysis at the NERC Radiocarbon Facility (East Kilbride, UK)
Authors: Garnett M H , Murray C
Published: January 2017

Cartridges containing a zeolite molecular sieve are used for the field collection of CO2 from a variety of environments (e.g. atmosphere, soil respiration, evasion from surface waters) for accelerator mass spectrometry (AMS) radiocarbon analysis by the NERC Radiocarbon Facility. Previously, sample CO2 was recovered from the sieves by heating under vacuum prior to cryogenic purification and graphitization. An additional heating and evacuation stage was used to prepare the cartridge for the next sample. We have recently developed an alternative method using heating and purging with nitrogen gas to remove sample CO2 from the molecular sieve. An infrared gas analyzer (IRGA) is used to continuously monitor CO2 content in the purge gas. The preparation of the molecular sieve cartridge for the next use is performed simultaneously and the IRGA reading is used to verify that all sample CO2 has been removed from the sieve, ensuring insignificant carryover of CO2 into the next sample. We present the results of a suite of standards of distinctly different 14C and stable-carbon isotope composition, which we used to confirm the reliability of the new procedure. The new method has considerably reduced the time required to process a single sample from at least 2 hr to less than 40 min, and reduced the minimum sample size by 50%.
Bioapatite 14C Age of Giant Mammals from Brazil
Authors: Cherkinsky Alexander , Dantas Mário André Trindade , Cozzuol Mario Alberto
Published: January 2017

We investigated the radiocarbon age and stable isotope composition of bioapatite from bone, enamel, and dentine material from 3 different species of extinct mammals in South America. Most samples of Eremotherium laurillardi, Toxodon platensis, and Notiomastodon platensis were collected in natural depressions located in the northeastern Brazilian provinces of Sergipe, Bahia, and Rio Grande do Norte. All samples studied were devoid of collagen, which had decomposed as a result of high microbiological activity in this tropical region. We have instead analyzed the bioapatite fraction of the samples, which was relatively well preserved even in these harsh tropical conditions. The mineral fraction of bone and tooth material does not usually undergo microbiological decomposition but may be exposed to isotopic exchange with environmental carbonates. The problem thus becomes one of separating the diagenetic carbonates without destroying the bioapatite. We offer a technique for removing the secondary diagenetic carbonates by treatment with diluted acetic acid in a vacuum. We also demonstrate that proper pretreatment of bone and tooth samples allows the separation of diagenetic carbonates from bioapatite, as long as the carbon in these samples has not degraded completely. Bone, enamel, and dentine samples from individuals of the 3 mammalian species were dated using this technique and were compared to results by other researchers from the literature. Date ranges for the species presented were in good agreement with prior research. A comparison with other dating techniques such as U/Th and ESR shows the reliability of the treatment described and the feasibility of 14C dating the bioapatite fraction given certain conditions. In 2 cases, we dated bone enamel and dentine samples from the same individuals of N. platensis, with results between 14 and 21 ka. Results from dating samples of T. platensis are between 11.5 and 13 ka. The oldest tissue in both cases was dentine. The dating of enamel and dentine from the same species did not show regular differences; however, more often the dentine material was older. The oldest date, ≃22.5 ka for E. laurillardi, was obtained on the bioapatite fraction of dentine.
Collagen Quality Indicators for Radiocarbon Dating of Bones: New Data on Bronze Age Cyprus
Authors: Calabrisotto C Scirè , Fedi M E , Caforio L , Bombardieri L , Mandò P A
Published: January 2017

Radiocarbon dating of bones can be very useful in archaeological contexts, especially when dealing with funerary deposits lacking material culture, e.g. pottery vessels. 14C measurements of bone samples are usually performed on the extracted collagen residue. The content and the quality of collagen can vary significantly, mainly depending on bone preservation and diagenesis. Generally speaking, environmental conditions such as low pH level of soils, high temperatures, and percolating groundwaters, typical of arid and tropical zones, can affect the preservation of collagen; at the same time, bones recovered in such environments are more likely to be contaminated with carbon from the surrounding environment. Possible contamination of samples can also occur in temperate zones. While low collagen content is a condition we cannot overcome, we can use several chemical and elemental indicators in order to assess collagen quality. Among these, the C/N atomic ratio is considered a good parameter for detecting low-quality collagen and possibly contaminated samples. In a combustion and graphitization setup like that installed at INFN-LABEC, Florence, measurement can be easily performed using an elemental analyzer when combusting the sample prior to graphitization, thus requiring no extra effort (or extra amount of sample) during the preparation procedure. Bone samples recently 14C dated at INFN-LABEC have confirmed that the measurement of C/N atomic ratios can give some indications of the collagen quality. The bone material was collected from 3 necropoles of the Bronze Age period in Cyprus (Erimi-Laonin tou Porakou, Lophou-Kolaouzou, and Erimi-Kafkalla&Pitharka, along the Kouris Valley), an area characterized by environmental conditions that do not favor bone preservation. Samples were treated to extract collagen and measured by accelerator mass spectrometry (AMS). 14C results have been compared with the archaeological evidence, showing some relationship between measured C/N atomic ratios and collagen quality. In particular, when grouping the measured samples according to their C/N ratio, the agreement between 14C dates and archaeological evidence is good or inconsistent when the C/N ratio clearly falls inside or outside the “recommended” range, respectively, with a still reasonable agreement also when it is slightly above the upper limit of that range.
Behavioral Variability in ABA Chemical Pretreatment Close to the 14C Age Limit
Authors: Santos Guaciara M , Ormsby Kaelyn
Published: January 2017

The acid-base-acid (ABA) procedure is a common chemical pretreatment used on most organic matter samples. Although this pretreatment is straightforward, there is no consensus among labs about the optimum strength of the chemicals, or even the temperature, to be used for digestions. Comparisons between 14C results obtained by samples undergoing ABA against other wet oxidations, such as acid-base oxidation followed by stepped-combustion (ABOX-SC) or α-cellulose on wood, have sometimes suggested that ABA does not always remove all contaminating carbon. In addition, if not all ABA protocols are the same, could it be said that one procedure is better than others or comparable to wet-oxidation pretreatments, if rigorously applied? To determine whether 14C-free samples showed any fraction modern carbon (FmC) deviations due to pretreatment strategies, 3 experiments were carried out. The first compared 14C results for wood samples at or near the limit of 14C dating, pretreated with a standard ABA protocol used at UC Irvine's Keck Carbon Cycle Accelerator Mass Spectrometry (KCCAMS) facility, with those obtained from ABA- and ABOX-SC-prepared aliquots of the same samples performed at Australian National University (ANU) in 2001. The second experiment subjected wood samples, ranging from ∼12 ka BP to 14C-free, to 5 selected published ABA pretreatments. Third, we evaluated whether the ABA protocol needs a higher-strength final acid step (particularly important for removing CO2 absorption when samples are submerged in alkaline solutions). We are able to show that rigorous ABA treatments exist that can provide robust, reproducible results for many wood samples that are known to be >>50 ka BP, implying that a lack of control over the procedure's outcome might be sample-related, rather than due simply to inadequacies in the chemical pretreatment.
A Wet Oxidation Method for AMS Radiocarbon Analysis of Dissolved Organic Carbon in Water
Authors: Leonard Alex , Castle Stephanie , Burr G S , Lange Todd , Thomas Jim
Published: January 2017

We present a method for the extraction of dissolved organic carbon (DOC) from water. The method is adapted from Burr et al. (2001) using the basic steps: 1) sample filtration; 2) acidification to liberate and remove dissolved inorganic carbon (DIC); 3) evaporation of the sample to isolate salts that include trace quantities of carbon; 4) combustion of the salts; and 5) purification of the CO2. Two significant improvements have been made to the earlier method. The first is to use wet oxidation with potassium permanganate to oxidize organics in place of the combustion step and the second is the development of a reduction/oxidation purification procedure to remove sulfur and nitrogen oxides that may form during the oxidation step. Wet oxidation has a practical advantage over the previous method because it proceeds at low temperature (70 °C). The original method required quartz vessels to oxidize the salts at 900 °C. At this temperature, salts in the samples formed gases that interfered with the isolation of CO2 and the quartz vessels degraded with each combustion, affecting their structural integrity. The expensive quartz vessels could only be used for a limited number of samples, whereas Pyrex vessels used for wet oxidation are inexpensive and can be used indefinitely.

The blank fraction modern carbon (f) and its mass dependence for the refined technique was determined from repeat analyses of salicylic acid produced from petrochemicals. For samples with a mass m above 0.5 mg, F = 0.0083 ± 0.0011. For samples below 0.5 mg, the blank follows a 1/m dependence as observed for other accelerator mass spectrometry (AMS) 14C measurements (Donahue et al. 1990). The reproducibility of the method is demonstrated using repeat measurements from a variety of samples, including a sample measured with the former high-temperature 900 °C combustion technique. The virtues of the wet oxidation method are that it is economical, produces a low blank, and provides good reproducibility.
Sealed Glass Tube Combustion of μg-Sized Aerosol Samples
Authors: Genberg J , Perron N , Olsson M , Stenström K
Published: January 2017

It is important to evaluate each step in radiocarbon analysis to ensure that the whole process is as efficient and accurate as possible. Aerosol filter samples contain a myriad of carbonaceous compounds with varying resistance to oxidation. Complete combustion of the sample is thus of great importance to ensure that the graphitized sample is representative of the original filter sample. We have evaluated sealed tube combustion of μg-sized aerosol samples using different types and amounts of reagents. Successful analysis of aerosol samples as small as 20 μg C was possible following small changes to our standard on-line method. The sealed tube combustion method performs well for standard samples containing 11 μg C.
Status of Sample Combustion and Graphitization Lines at INFN-LABEC, Florence
Authors: Fedi M E , Bernardoni V , Caforio L , Calzolai G , Carraresi L , Manetti M , Taccetti F , Mandò P A
Published: January 2017

Since installation of the new accelerator at INFN-LABEC in Florence in 2004, the workload has progressively increased in the radiocarbon dating laboratory, requiring a faster sample preparation throughput and greater versatility to allow for a larger variety of treated materials. The “standard” sample preparation line is based on an elemental analyzer (EA) for the combustion of the pretreated samples, and a vacuum line where the CO2 is collected and then converted to graphite. This line has been recently redesigned while maintaining the EA, since this instrument provides us reliable and fast sample combustion and separation of gases. The volumes were optimized and all the mechanical parts (e.g. the fittings) were changed in order to improve the vacuum level, thus decreasing the possibility of contamination; finally, the number of graphitization reactors was doubled (from 4 to 8). In those rare cases involving samples characterized by a complex nearly graphitic structure (e.g. burnt residues), the EA might not guarantee a complete combustion. For these samples, we successfully tested the new sample preparation line that has been recently installed at LABEC and especially dedicated to aerosol samples. This line is equipped with a custom-made combustion oven able to heat to 1000 °C. The subsequent gas separation is accomplished by chemical and thermal traps. As an example, the dating of organic matter collected from an Etruscan bronze statue will be presented and discussed.
Age Determination of the Kawagodaira Volcanic Eruption in Japan by 14C Wiggle-Matching
Authors: Tani Sayaka , Kitagawa Hiroyuki , Hong Wan , Park Jung Hun , Sung Ki Suk , Park Gyujun
Published: January 2017

The Kawagodaira Volcano is located on the northwest slope of Amagi Volcano on the Izu Peninsula of central Japan. The fine pumice that erupted from Kawagodaira Volcano is widely distributed in the central and western parts of the Japanese mainland. Here, we report an accurate eruption age determined by radiocarbon wiggle-matching of a Japanese cedar timber excavated from the pyroclastic deposit at the pumice flow terminal of Kawagodaira Volcano. The 14C wiggle-match estimate for the Kawagodaira Volcano eruption is 1210–1187 cal BC (95.4% confidence level).
Regional Offset of Radiocarbon Concentration and Its Variation in the Korean Atmosphere from AD 1650–1850
Authors: Hong Wan , Park Jung Hun , Park Gyujun , Sung Ki Suk , Park Won Kyu , Lee Jong-Geol
Published: January 2017

A series of annual tree-ring measurements has been performed in order to reconstruct the radiocarbon concentration variation in the Korean atmosphere from AD 1650 to 1850. The absolute ages of the samples were determined using dendrochronology. Alpha-cellulose extraction was applied to prepare the tree-ring samples for precise 14C measurement. The 14C concentrations of the tree rings were then plotted with the dendrochronological ages and showed that during the period AD 1650–1850, the discrepancy in 14C concentration in the Korean atmosphere from IntCal data is small enough to use IntCal data without any further correction. This is nearly one third of the average offset of the 400 yr from AD 1250 to 1650. One of the probable causes for the regional offset around Korea is the contribution of 14C-depleted CO2 released from the northern Pacific Ocean, where old deep water upwells to the surface. It is likely that the release rate of 14C-depleted CO2 decreased due to the temperature change during the Little Ice Age.
Bayesian Approach to 14C Dates for Estimation of Long-Term Archaeological Sequences in Arid Environments: The Holocene Site of Takarkori Rockshelter, Southwest Libya
Authors: Cherkinsky Alexander , di Lernia Savino
Published: January 2017

Caves and rockshelters are critical loci for the analysis and understanding of human trajectories in the past. Use and re-uses of the same context, however, might have had serious impacts on depositional aspects. This is particularly true for the archaeological history of desert environments, such as the central Sahara, where most of the deposits are made of loose sand, rich in organic matter. Besides traditional stratigraphic reconstructions and a detailed study of the material culture, radiocarbon measurements from different contexts analyzing several types of material (bone, dried and charred coprolite, uncharred and charred plant remains, etc.) can highlight intrinsic critical aspects of 14C determinations. These measurements must be carefully evaluated to provide a correct chronological assessment of the life history of the site. We present the statistics derived from the set of about 50 14C measurements from the site of Takarkori, southwest Libya, where early Holocene foragers and then groups of cattle herders inhabited the area from ∼10,200 to 4600 cal yr BP. We have used the BCal Bayesian 14C calibration program designed for statistical presentation of the calibrated data and the estimation of their probability for different phases. Results indicate that the Takarkori rockshelter was occupied during 4 phases of the following cultures: Late Acacus from 10,170 to 8180 cal yr BP; Early Pastoral, 8180–6890 cal yr BP; Middle Pastoral, 7160–5610 cal yr BP; and Late Pastoral, 5700–4650 cal yr BP.
Fossil-Fuel-Derived CO2 Contribution to the Urban Atmosphere in Guangzhou, South China, Estimated by 14CO2 Observation, 2010–2011
Authors: Ding P , Shen C D , Yi W X , Wang N , Ding X F , Fu D P , Liu K X
Published: January 2017

From October 2010 to November 2011, the urban atmospheric CO2 concentration in Guangzhou ranged from 550 to 460 ppm, with mean monthly concentration fluctuating between 530 and 470 ppm. A lower concentration was observed in summer and autumn, while a higher concentration occurred in spring and winter. The urban atmospheric CO2 δ13C value varied between −9.00 and −13.10%, with mean monthly value fluctuating between −9.60 and −11.80%. There was no significant relationship between the CO2 concentration and δ13C value, reflecting the influence from the fossil-fuel-derived CO2 on the urban atmospheric CO2. The urban atmospheric CO2 Δ14C value fluctuated dramatically from 29.1 ± 2.5% to −85.2 ± 3. 1%, with a mean annual value of −16.4 ± 3.0%. A similar seasonal variation of Δ14C value with the concentrations was observed: the higher Δ14C values mainly appeared in summer and autumn (July to September), with a mean value of about −5.2 ± 2.9%, while lower Δ14C values occurred in spring and winter (December to April), about −27.1 ± 3.2% average. Based on the atmospheric Δ14C values, the calculated fossil-fuel-derived CO2 concentrations range between 1 and 58 ppm, with the mean annual concentration around 24 ppm. Similarly, a lower fossil-fuel-derived CO2 concentration appeared in summer and autumn (July to September) with a mean value of ∼17 ppm, while the higher fossil-fuel-derived CO2 concentration occurred in spring and winter (December to April) with an average value of ∼29 ppm. A comparison of the CO2 concentrations before and after the Guangzhou Asian Games (in November 2010) and the Spring Festival of 2011 confirmed that human activities can greatly decrease the fossil-fuel-derived CO2 emissions to the urban atmosphere in Guangzhou.
Carbon Isotope Composition of Atmospheric Carbon Dioxide in Southern Poland: Imprint of Anthropogenic CO2 Emissions in Regional Biosphere
Authors: Pazdur Anna , Kuc Tadeusz , Pawełczyk Sławomira , Piotrowska Natalia , Sensuła Barbara , Rozanski Kazimierz
Published: January 2017

Southern Poland is home to numerous large mining and energy industry facilities, which consume relatively great amounts of fossil fuels. Temporal and spatial distribution of CO2 emissions to the atmosphere were estimated on the basis of 13C and 14C isotope measurements in atmospheric CO2 and in α-cellulose from pine tree rings. The Suess effect was evaluated in the atmospheric CO2 from the High Tatra Mountains (Kasprowy Wierch) and the urban area (Kraków), as well as in tree rings from Niepołomice Forest near Kraków. Two different models were used to estimate the emission component recorded in tree ring δ13C on the background of climatic changes.
Radiocarbon Dating of Groundwater in Granite Fractures in Abukuma Province, Northeast Japan
Authors: Takahashi H A , Nakamura T , Tsukamoto H , Kazahaya K , Handa H , Hirota A
Published: January 2017

Knowledge of the groundwater age is indispensable for understanding groundwater flow in crystalline rocks. The present study is the first to discuss the radiocarbon ages of groundwater in Abukuma granite, Fukushima Prefecture, northeast Japan. The vertical profiles of 14C dates and δ13C are obtained from 3 boreholes (depths of 140, 230, and 306 m). Chemical and carbon isotopic compositions suggest that dead-carbon contamination of groundwater occurred during groundwater storage in the fractures. 14C concentration was corrected by using isotopic mass balance in which dead-carbon contamination of the groundwater was considered. The 14C dates ranged from modern to ≃16 ka. The relationship between tritium and 14C data in 1 borehole suggests the simultaneous inflow of shallow groundwater to deeper levels occur for the depths between 60 and 100 m. The vertical profiles of 14C dates indicate a relatively constant age of 10–16 ka for groundwater deeper than 100 m, which may have been influenced by rapid sea-level changes after the glacial period.
Information and choice of residential care provider for older people: a comparative study in England, the Netherlands and Spain
Authors: TRIGG LISA , KUMPUNEN STEPHANIE , HOLDER JACQUETTA , MAARSE HANS , SOLÉ JUVÉS MERITXELL , GIL JOAN
Published: January 2017

This study compared how older people use quality information to choose residential care providers in England, the Netherlands and Spain (Catalonia). The availability of information varies between each country, from detailed inspection and survey information in the Netherlands, through to a lack of publicly available information in Catalonia. We used semi-structured interviews and group workshops with older people, families and professionals to compare experiences of the decision-making process and quality information, and also to explore what quality information might be used in the future. We found that most aspects of the decision-making experience and preferences for future indicators were similar across the three countries. The use of quality information was minimal across all three, even in England and the Netherlands where information was widely available. Differences arose mainly from factors with the supply of care. Older people were most interested in the subjective experiences of other residents and relatives, rather than ‘hard’ objective indicators of aspects such as clinical care. We find that the amount of publicly available quality information does not in itself influence the decisions or the decision-making processes of older people and their carers. To improve the quality of decisions, more effort needs to be taken to increase awareness and to communicate quality in more accessible ways, including significant support from professionals and better design of quality information.