bluuebunny/crossref_metadata_2025 huggingface dataset:
The differing impacts of operational and financial slack on occupational safety in varying market conditions
Authors: Wiengarten Frank , Fan Di , Lo Chris K.Y. , Pagell Mark
Published: January 2017

Operations management scholars have long debated the right level of slack resources required to optimize a production system. Recent research suggests that the right level of operational slack, typically in the form of inventory, is very little but not none. However, this conclusion was reached without considering the role of slack resources in occupational safety, which is a critical oversight since the safety literature predicts that the reduction of operational slack harms workers. To address this gap, secondary data from 3945 publically listed U.S. firms is used to explore the role of operational and financial slack as well as market factors in occupational safety. The results show that decreasing operational slack harms workers and that this effect is mitigated when firms hold higher levels of financial slack. Furthermore, the external market environment also plays a crucial role in the operational slack – safety relationship.
Androgens and Psychosocial Factors Related to Sexual Dysfunctions in Premenopausal Women∗
Authors: Wåhlin-Jacobsen Sarah , Kristensen Ellids , Pedersen Anette Tønnes , Laessøe Nanna Cassandra , Cohen Arieh S. , Hougaard David M. , Lundqvist Marika , Giraldi Annamaria
Published: January 2017

Introduction

The female sexual response is complex and influenced by several biological, psychological, and social factors. Testosterone is believed to modulate a woman's sexual response and desire, because low levels are considered a risk factor for impaired sexual function, but previous studies have been inconclusive.

Aim

To investigate how androgen levels and psychosocial factors are associated with female sexual dysfunction (FSD), including hypoactive sexual desire disorder (HSDD).

Methods

The cross-sectional study included 428 premenopausal women 19 to 58 years old who completed a questionnaire on psychosocial factors and had blood sampled at days 6 to 10 in their menstrual cycle. Logistic regression models were built to test the association among hormone levels, psychosocial factors, and sexual end points.

Main Outcome Measures

Five different sexual end points were measured using the Female Sexual Function Index and the Female Sexual Distress Scale: impaired sexual function, sexual distress, FSD, low sexual desire, and HSDD. Serum levels of total and free testosterone, androstenedione, dehydroepiandrosterone sulfate, and androsterone glucuronide were analyzed using mass spectrometry.

Results

After adjusting for psychosocial factors, women with low sexual desire had significantly lower mean levels of free testosterone and androstenedione compared with women without low sexual desire. None of the androgens were associated with FSD in general or with HSDD in particular. Relationship duration longer than 2 years and mild depressive symptoms increased the risk of having all the sexual end points, including FSD in general and HSDD in particular in multivariate analyses.

Conclusion

In this large cross-sectional study, low sexual desire was significantly associated with levels of free testosterone and androstenedione, but FSD in general and HSDD in particular were not associated with androgen levels. Length of relationship and depression were associated with FSD including HSDD.
Spherical convective dynamos in the rapidly rotating asymptotic regime
Authors: Aubert Julien , Gastine Thomas , Fournier Alexandre
Published: January 2017

Self-sustained convective dynamos in planetary systems operate in an asymptotic regime of rapid rotation, where a balance is thought to hold between the Coriolis, pressure, buoyancy and Lorentz forces (the MAC balance). Classical numerical solutions have previously been obtained in a regime of moderate rotation where viscous and inertial forces are still significant. We define a uni-dimensional path in parameter space between classical models and asymptotic conditions from the requirements to enforce a MAC balance and to preserve the ratio between the magnetic diffusion and convective overturn times (the magnetic Reynolds number). Direct numerical simulations performed along this path show that the spatial structure of the solution at scales larger than the magnetic dissipation length is largely invariant. This enables the definition of large-eddy simulations resting on the assumption that small-scale details of the hydrodynamic turbulence are irrelevant to the determination of the large-scale asymptotic state. These simulations are shown to be in good agreement with direct simulations in the range where both are feasible, and can be computed for control parameter values far beyond the current state of the art, such as an Ekman number $E=10^{-8}$. We obtain strong-field convective dynamos approaching the MAC balance and a Taylor state to an unprecedented degree of accuracy. The physical connection between classical models and asymptotic conditions is shown to be devoid of abrupt transitions, demonstrating the asymptotic relevance of classical numerical dynamo mechanisms. The fields of the system are confirmed to follow diffusivity-free, power-based scaling laws along the path.
Optimal undulatory swimming for a single fish-like body and for a pair of interacting swimmers
Authors: Maertens Audrey P. , Gao Amy , Triantafyllou Michael S.
Published: January 2017

We establish through numerical simulation conditions for optimal undulatory propulsion for a single fish, and for a pair of hydrodynamically interacting fish, accounting for linear and angular recoil. We first employ systematic two-dimensional (2-D) simulations to identify conditions for minimal propulsive power of a self-propelled fish, and continue with targeted 3-D simulations for a danio-like fish; all at Reynolds number 5000. We find that the Strouhal number, phase angle between heave and pitch at the trailing edge, and angle of attack are principal parameters. For 2-D simulations, imposing a deformation based on measured displacement for carangiform swimming provides, at best, efficiency of 35 %, which increases to 50 % for an optimized motion; for a 3-D fish, the efficiency increases from 22 % to 34 %. Indeed, angular recoil has significant impact on efficiency, and optimized body bending requires maximum bending amplitude upstream of the trailing edge. Next, we turn to 2-D simulation of two hydrodynamically interacting fish. We find that the upstream fish benefits energetically only for small distances. In contrast, the downstream fish can benefit at any position that allows interaction with the upstream wake, provided its body motion is timed appropriately with respect to the oncoming vortices. For an in-line configuration, one body length apart, the efficiency of the downstream fish can increase from 50 % to 60 %; for an offset arrangement it can reach 80 %. This proves that in groups of fish, energy savings can be achieved for downstream fish through interaction with oncoming vortices, even when the downstream fish lies directly inside the jet-like flow of an upstream fish.
EGYPTIAN COMICS AND THE CHALLENGE TO PATRIARCHAL AUTHORITARIANISM
Authors: Høigilt Jacob
Published: January 2017

Adult comics are a new medium in the Arab world. This article is the first in-depth study of their emergence and role within Arab societies. Focused on Egypt, it shows how adult comics have boldly addressed political and social questions. Seeing them as part of a broader cultural efflorescence in Egypt, I argue that, against patriarchal authoritarianism, adult comics have expressed an alternative ideology of tolerance, civic rights and duties, individualism, creativity, and criticism of power. Specifically, they present a damning critique of Egypt's authoritarian order, as well as of the marginalization of women and broader gender dynamics in Egyptian society. Through frank humor, a playful style, and explicit graphics, they give voice to the concerns of young Egyptians. Connecting comics to other art forms such as music, graffiti, and political cartoons, I situate them within a critical cultural movement that came to the fore with the Egyptian uprising of 2011.
Historicizing Slavery in the Medieval Islamic World
Authors: Perry Craig
Published: January 2017

As Nadia Maria El Cheikh has said of the harem in western scholarship on the premodern Islamic world, slavery and the slave trade have yet to be fully historicized. While scholars of Abbasid-era slavery have made tremendous contributions in this regard over the last two decades, there remain ample opportunities to expand the chronological and geographic scope of their work. What does it mean to historicize slavery in the medieval Islamic Middle East and why is it worth doing?
Slavery and the Historiography of Non-Muslims in the Medieval Middle East
Authors: Weitz Lev
Published: January 2017

The study of non-Muslims in Islamic societies has long been a robust subfield in the historiography of the medieval Middle East. But its literature has blind spots, a significant example of which concerns slavery as a constitutive institution of non-Muslim communities. Much recent scholarship on medieval non-Muslims has tended to privilege religious affiliation as an explanatory category of social experience, leaving other legal statuses and modes of identification—especially slavery—underanalyzed. This piece will survey this historiographical hole. It will then offer a brief analysis of some Abbasid-era Syriac Christian material in which slavery figures prominently, concubines and concubinage in particular. My goal is to provide an example of how attending to the place of slavery in non-Muslim communities facilitates a much-needed historiographical shift of focus from reified religious identities to the social practices, institutions, and hierarchies upon which those communities were built.
Diagnosing collisionless energy transfer using field–particle correlations: Vlasov–Poisson plasmas
Authors: Howes Gregory G. , Klein Kristopher G. , Li Tak Chu
Published: January 2017

Turbulence plays a key role in the conversion of the energy of large-scale fields and flows to plasma heat, impacting the macroscopic evolution of the heliosphere and other astrophysical plasma systems. Although we have long been able to make direct spacecraft measurements of all aspects of the electromagnetic field and plasma fluctuations in near-Earth space, our understanding of the physical mechanisms responsible for the damping of the turbulent fluctuations in heliospheric plasmas remains incomplete. Here we propose an innovative field–particle correlation technique that can be used to measure directly the secular energy transfer from fields to particles associated with collisionless damping of the turbulent fluctuations. Furthermore, this novel procedure yields information about the collisionless energy transfer as a function of particle velocity, providing vital new information that can help to identify the dominant collisionless mechanism governing the damping of the turbulent fluctuations. Kinetic plasma theory is used to devise the appropriate correlation to diagnose Landau damping, and the field–particle correlation technique is thoroughly illustrated using the simplified case of the Landau damping of Langmuir waves in a 1D-1V (one dimension in physical space and one dimension in velocity space) Vlasov–Poisson plasma. Generalizations necessary to apply the field–particle correlation technique to diagnose the collisionless damping of turbulent fluctuations in the solar wind are discussed, highlighting several caveats. This novel field–particle correlation technique is intended to be used as a primary analysis tool for measurements from current, upcoming and proposed spacecraft missions that are focused on the kinetic microphysics of weakly collisional heliospheric plasmas, including the Magnetospheric Multiscale (MMS), Solar Probe Plus, Solar Orbiter and Turbulence Heating ObserveR (THOR) missions.
Motivating and engaging volunteer hunters to control the invasive alien American mink Neovison vison in Norway
Authors: Stien J. , Hausner V. H.
Published: January 2017

Invasive alien species can have widespread negative effects on native biodiversity. We investigated the prospects of engaging hunters in large-scale collaborative efforts to control non-native mink Neovison vison populations in Norway. We invited members of the Norwegian Association of Hunters and Anglers to complete an online questionnaire to ascertain their support for conservation and their level of effort to remove mink, in the context of hunting motivations and bounty payments. The general interest in mink control programmes was low but participants perceived the mink to be of conservation concern. Bounty payments influenced mink catches, with hunters who received payments catching a mean of 4.70 more individuals per hunter than those who did not receive payments (P < 0.001). Mink hunters who preferred to hunt alone and had no preference for hunting locally reportedly caught on average 1.87 more mink per hunter than those who preferred to hunt in company (P < 0.001). The majority of hunters preferred government-led programmes (47%), and investment in bounty programmes (52%) was their main recommendation to improve mink hunting. Hunters can be a valuable component of a mink removal task force and could decrease the likelihood of recolonization of mink in the buffer areas of core conservation target areas.
Chemotherapy of leishmaniasis: present challenges
Authors: ULIANA SILVIA R. B. , TRINCONI CRISTIANA T. , COELHO ADRIANO C.
Published: January 2017

Cutaneous and visceral leishmaniasis are amongst the most devastating infectious diseases of our time, affecting millions of people worldwide. The treatment of these serious diseases rely on a few chemotherapeutic agents, most of which are of parenteral use and induce severe side-effects. Furthermore, rates of treatment failure are high and have been linked to drug resistance in some areas. Here, we reviewed data on current chemotherapy practice in leishmaniasis. Drug resistance and mechanisms of resistance are described as well as the prospects for applying drug combinations for leishmaniasis chemotherapy. It is clear that efforts for discovering new drugs applicable to leishmaniasis chemotherapy are essential. The main aspects on the various steps of drug discovery in the field are discussed.
On the Eve of Urbanization: Bayesian Model Dating for Medieval Turku
Authors: Oinonen M , Hilasvuori E , Mehtonen H , Uotila K , Zetterberg P
Published: January 2017

The era of early urbanization in Finland coincides with large variations in the atmospheric radiocarbon concentration around the 13th–14th centuries AD. Therefore, the uncertainties of an individual 14C date are too large to support studies of this time period effectively. In this work, we have employ tree-ring wiggle-matching methodology and used Bayesian modeling of dates to account for stratigraphical a priori information within Aboa Vetus Museum, Turku, Finland. The wiggle-match method helps significantly to overcome the calibration-curve-induced challenges within 14C dating. The results of the dating model agree with the typological dates of the archaeological finds and illustrate a gradual evolution of urbanization in one of the oldest cities in Finland.
Radiocarbon and Tree-Ring Dates of the Bes-Shatyr #3 Saka Kurgan in the Semirechiye, Kazakhstan
Authors: Panyushkina Irina , Grigoriev Fedor , Lange Todd , Alimbay Nursan
Published: January 2017

This study employs tree-ring crossdating and radiocarbon measurements to determine the precise calendar age of the Bes-Shatyr Saka necropolis (43°47′N, 81°21′E) built for wealthy tribe leaders in the Ili River Valley (Semirechiye), southern Kazakhstan. We developed a 218-yr tree-ring chronology and a highly resolved sequence of14C from timbers of Bes-Shatyr kurgan #3. A 4-decadal-point14C wiggle dates the Bes-Shatyr necropolis to 600 cal BC. A 47-yr range of cutting dates adjusted the kurgan date to ∼550 BC. This is the first result of high-resolution14C dating produced for the Saka burials in the Semirechiye. The collective dating of Bes-Shatyr indicates the early appearance of the Saka necropolis in the Semirechiye eastern margins of the Saka dispersal. However, the date is a couple of centuries younger than previously suggested by single14C dates. It is likely that the Shilbiyr sanctuary (location of the Bes-Shatyr) became a strategic and sacral place for the Saka leadership in the Semirechiye long before 550 BC. Another prominent feature of the Semirechiye burial landscape, the Issyk necropolis enclosing the Golden Warrior tomb, appeared a few centuries later according to14C dating reported by other investigators. This study contributes to the Iron Age chronology of Inner Asia, demonstrating successful results of14C calibration within the Hallstatt Plateau of the14C calibration curve. It appears that the wide range of calibrated dates for the Saka occurrences in Kazakhstan (from 800 BC to AD 350) is the result of the calibration curve constraints around the middle of the 1st millennium BC.
Dating Charred Remains on Pottery and Analyzing Food Habits in the Early Neolithic Period in Northeast Asia
Authors: Kunikita Dai , Shevkomud Igor , Yoshida Kunio , Onuki Shizuo , Yamahara Toshiro , Matsuzaki Hiroyuki
Published: January 2017

This study reconstructs food habits through carbon and nitrogen isotope analysis, and C/N analysis of charred residues inside pottery from Amur River sites in Russia (Goncharka 1 site, Novotroitskoe 10 site, Kondon 1 site) and in Hokkaido, Japan (Taisho 3 site, Yachiyo A site). We obtained dates from 12,330 to 7920 BP for these sites. There are major differences in the carbon and nitrogen isotope ratios between the Taisho 3 site (δ13C: -21.7 to -24.1; δ15N: 11.9–14.7%) and the other sites (δ13C:-22.0 to -27.1%; δ15N: 7.1–13.1%), suggesting that the people of the Taisho 3 site made use of anadromous fish such as salmonids and some species of trout, as well as marine resources. The dates from the other sites except Taisho 3 were assumed to be from a mixture of marine foods, C3 plants and terrestrial animals, and freshwater fish. The food boiled in the pots also indicated a high dependence on marine resources during the initial stages of the emergence of pottery.
Dating Anomalies in the Archaeology of the 7th Century BC
Authors: Porter Robert M , Dee Michael W
Published: January 2017

Two recently published sets of radiocarbon dates, one from Mesopotamia and one from Anatolia, gave anomalous results. On the basis of historical analysis, both sets were expected to date to the 7th century BC. However, the 14C results were more than a century older than this. We tested samples from an Egyptian mummy, also historically dated to the 7th century BC, to see if such discrepancies were more widespread at this time. We did not find evidence of such a problem, but the results do provide insights into the reuse of old wood in ancient Egyptian coffins. We include publication of an earlier set of dates from the same mummy and coffin set.
West Central African Peoples: Survey of Radiocarbon Dates over the Past 5000 Years
Authors: Oslisly Richard , Bentaleb Ilham , Favier Charly , Fontugne Michel , Gillet Jean François , Morin-Rivat Julie
Published: January 2017

Tracing human history in west central Africa suffers from a scarcity of historical data and archaeological remains. In order to provide new insight into this problem, we reviewed 733 radiocarbon dates of archaeological sites from the end of the Late Stone Age, Neolithic Stage, and Early and Late Iron Age in Cameroon, Gabon, Central African Republic, Equatorial Guinea, Republic of Congo, and the western Democratic Republic of Congo. This review provides a spatiotemporal framework of human settlement in the forest biome. Beyond the well-known initial spread of Iron Age populations through central African forests from 2500 cal BP, it depicts the geographical patterns and links with the cultural evolution of the successive phases of human expansion from 5000 to 3000 cal BP and then from 3000 to 1600 cal BP, of the hinterland depopulation from 1350 to 860 cal BP, and of recolonization up to 500 cal BP.
Direct14C Dating of Early and Mid-Holocene Saharan Pottery
Authors: Messili Lamia , Saliège Jean-François , Broutin Jean , Messager Erwan , Hatté Christine , Zazzo Antoine
Published: January 2017

The aim of this study is to directly radiocarbon date pottery from prehistoric rock-art shelters in the Tassili n'Ajjer (central Sahara). We used a combined geochemical and microscopic approach to determine plant material in the pottery prior to direct14C dating. The ages obtained range from 5270 ± 35 BP (6276–5948 cal BP) to 8160 ± 45 BP (9190–9015 cal BP), and correlate with the chronology derived from pottery typology. Our results document the transition from pre-Pastoral to Pastoral contexts, dated to the early-mid Holocene transition, and confirm that vegetal temper in pottery can provide reliable14C ages within Saharan contexts.
Can we Use Calcined Bones for 14C Dating the Paleolithic?
Authors: Zazzo Antoine , Lebon Matthieu , Chiotti Laurent , Comby Clothilde , Delqué-Količ Emmanuelle , Nespoulet Roland , Reiche Ina
Published: January 2017

This work aims to test the reliability of calcined bones for radiocarbon dating of the Paleolithic. Fifty-five calcined bone samples coming from Aurignacian and Gravettian layers at Abri Pataud (Dordogne, France) were selected based on their macroscopic features. For each sample, the heating state was estimated on the basis of bone crystallinity (splitting factor [SF] using FTIR) and δ13C value. Twenty-seven bone samples (3 unburnt and 24 calcined) from 5 different levels were prepared for 14C dating. The majority (15/24) of the calcined samples had to undergo a sulfix treatment prior to graphitization, probably due to the presence of cyanamide ion in these samples. The comparison between our results and recently published dates on bone collagen for the same levels shows that unburned bone apatite is systematically too young, while a third of the calcined bones fall within or very near the range of expected age. No clear correlation was found between 14C age offset and δ13C value or SF. Most of the sulfixed samples (14/16) yielded ages that were too young, while almost all of the non-sulfixed samples (8/9) gave ages similar or <0.2 pMC from the expected minimum age. Although preliminary, these results suggest that sulfix should be avoided if possible and that clean CO2 gas from well-calcined Paleolithic bones can provide reliable 14C ages.
Intercomparison of 14C Analysis of Carbonaceous Aerosols: Exercise 2009
Authors: Szidat S , Bench G , Bernardoni V , Calzolai G , Czimczik C I , Derendorp L , Dusek U , Elder K , Fedi M E , Genberg J , Gustafsson Ö , Kirillova E , Kondo M , McNichol A P , Perron N , Santos G M , Stenström K , Swietlicki E , Uchida M , Vecchi R , Wacker L , Zhang Y L , Prévôt A S H
Published: January 2017

Radiocarbon analysis of the carbonaceous aerosol allows an apportionment of fossil and non-fossil sources of airborne particulate matter (PM). A chemical separation of total carbon (TC) into its subtractions organic carbon (OC) and elemental carbon (EC) refines this powerful technique, as OC and EC originate from different sources and undergo different processes in the atmosphere. Although 14C analysis of TC, EC, and OC has recently gained increasing attention, interlaboratory quality assurance measures have largely been missing, especially for the isolation of EC and OC. In this work, we present results from an intercomparison of 9 laboratories for 14C analysis of carbonaceous aerosol samples on quartz fiber filters. Two ambient PM samples and 1 reference material (RM 8785) were provided with representative filter blanks. All laboratories performed 14C determinations of TC and a subset of isolated EC and OC for isotopic measurement. In general, 14C measurements of TC and OC agreed acceptably well between the laboratories, i.e. for TC within 0.015–0.025 F14C for the ambient filters and within 0.041 F14C for RM 8785. Due to inhomogeneous filter loading, RM 8785 demonstrated only limited applicability as a reference material for 14C analysis of carbonaceous aerosols. 14C analysis of EC revealed a large deviation between the laboratories of 28–79% as a consequence of different separation techniques. This result indicates a need for further discussion on optimal methods of EC isolation for 14C analysis and a second stage of this intercomparison.
Latest 14C Concentrations of Plant Leaves at High Altitudes in the Northern and Southern Hemispheres: Vertical Stability of Local Suess Effect
Authors: Sakurai Hirohisa , Tokanai Fuyuki , Kato Kazuhiro , Takahashi Yui , Sato Taichi , Kikuchi Satoshi , Inui Emiko , Arai Yumi , Masuda Kimiaki , Miyahara Hiroko , Mundia Charles , Tavera Wilfredo
Published: January 2017

The radiocarbon concentrations in plant leaves from different altitudes at 3 sampling locations were measured with the new compact accelerator mass spectrometer (AMS) at Yamagata University to investigate air mixing on a global scale. The sampling locations are Yamagata in the mid-latitudes of the Northern Hemisphere (NH), Kenya in the equatorial region (EQ), and Chacaltaya in the Southern Hemisphere (SH). The 14C concentrations of the plant leaves ranged from 102 to 105 pMC. The 14C concentrations at high altitudes and mountain summits showed similar values of 104.2 ± 0.28, 104.3 ± 0.36, and 104.4 ± 0.23 pMC at the Yamagata, Kenya, and Chacaltaya sites, respectively. These results indicate that air from the free troposphere is well mixed on a global scale. The local Suess effect was calculated using the 14C concentrations of leaves at the land surface and mountain summits. The fractions were estimated as 1.25 ± 0.3% and 0.87 ± 0.44% at Yamagata and Nairobi, respectively. This estimation method is more advantageous than the conventional calculation. The life cycle of the leaves sampled is 1 or 2 yr, and hence the leaves allow us to study the 14C concentrations in the ambient atmosphere during a narrow and specific time period.
AMS Radiocarbon Dating and Pollen Analysis of Core Ks0412-3 from Kashibaru Marsh in Northern Kyushu, Southwest Japan
Authors: Fujiki Toshiyuki , Okuno Mitsuru , Nakamura Toshio , Nagaoka Shinji , Mori Yuichi , Ueda Kyoko , Konomatsu Masahiko , Aizawa Jun
Published: January 2017

We performed pollen analysis and accelerator mass spectrometry (AMS) radiocarbon dating on cored sediments (KS0412-3) from Kashibaru Marsh, located in the western part of the Sefuri Mountains in northern Kyushu, southwestern Japan, to investigate environmental change around the marsh. Sediment accumulation began in this marsh around cal AD 1200 and continued with an estimated average sedimentation rate of about 4 mm/yr. Human rice cultivation at this location began around cal AD 1300 and was abandoned due to the deposition of a thick sand layer at around cal AD 1400. Since this event, the area has been maintained as a “natural” marsh.
Hydrological Changes After the Last Ice Retreat in Northern Poland Using Radiocarbon Dating
Authors: Michczyńska Danuta J , Starkel Leszek , Nalepka Dorota , Pazdur Anna
Published: January 2017

A simplified model of hydrological changes during the Late Glacial and Holocene is presented for the northern Polish regions that were ice covered during the Last Glacial. This reconstruction is based on a group of 197 radiocarbon dates from about 120 localities reflecting the sequence of alternating lake transgressions and regressions. The earliest transgressions were related to dead-ice melting (sometimes in 2–3 phases), while the later ones started during more humid phases. However, these were usually followed by regressions, which may have been connected with the formation of new drainage systems and with the overgrowing of shallow lakes by peat bogs.
From an Estuary to a Freshwater Lake: A Paleo-Estuary Evolution in the Context of Holocene Sea-Level Fluctuations, 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 Cecilia , de Oliveira Sonia Maria Barros , Teixeira Favaro Deborah Ines , De Fátima Rossetti Dilce , Lorente Flávio Lima , Borotti Filho Marcos Antonio , Schiavo Jolimar Antonio , Bendassolli José Albertino , França Marlon Carlos , Guimarães José Tasso Felix , Siqueira Geovane Souza
Published: January 2017

A sediment core was studied to characterize the influences of Holocene sea-level variations in the Barra Seca River valley, in the Atlantic rainforest, Linhares, Espírito Santo, southeastern Brazil. Biological proxies (pollen, spores, and sponge spicules), 14C dating, granulometry, δ13C, δ15N, C/N and major chemical elements revealed the establishment and the evolution of a paleo-estuary during the interval from ∼7700–585 cal BP. During the interval ∼7700–7000 cal BP, the study site was occupied by a bay-head delta, the inner portion of the paleo-estuary, presenting the most dense mangrove coverage of the entire record. In the interval ∼7000–3200 cal BP, the site was occupied by the central basin, possibly a consequence of the landward migration of the paleo-estuary. This interval presents reduced mangrove coverage, probably due to the permanent flooding of the valley. From ∼3200 cal BP, the marine influence at the site decreased probably as result of the seaward migration of the coast line. From ∼600 cal BP, the modern floodplain and freshwater lake were established. This interpretation is in agreement with the sea-level curves for the southeastern Brazilian coast, except for the fact that evidence of sea levels lower than the present at ∼4000 and ∼2500 cal BP as suggested by some authors were not found.
Radionuclide Studies of Stony Meteorites from Hot Deserts
Authors: Jull A J Timothy , Giscard Marlène D , Hutzler Aurore , Schnitzer Caitlin J , Zahn David , Burr George S , McHargue Lanny R , Hill Dolores
Published: January 2017

We summarize the use of radiocarbon produced by spallation in meteorites in space to determine their terrestrial age or residence time. This “age” gives us important information as it can be compared to the rates of weathering and infall of meteorites. The processes that affect the collection of meteorites in a given area can be related to the rates of infall of new meteorites, and the rate of removal by chemical weathering and physical erosion.
Determination of the Biobased Content in Plastics by Radiocarbon
Authors: Quarta Gianluca , Calcagnile Lucio , Giffoni Massimo , Braione Eugenia , D'Elia Marisa
Published: January 2017

Accelerator mass spectrometry (AMS) radiocarbon analyses were performed on biobased unsaturated polyester resins in order to assess the potential of the method for the determination of the bio-fraction. Different resins were synthesized in the laboratory with different proportions of raw materials of biogenic origin, and analyzed both in the liquid and in the solid form. As a preliminary step of the study, both the biobased and the fossil-derived raw materials were analyzed in order to determine their 14C content. A comparison of the obtained results with the expected ones allowed us to investigate the potential of the 14C method in this field as well as to address some still open issues such as the levels of uncertainty and accuracy as related to the calculation procedures, the correction for isotopic fractionation, and the effect of the presence of volatile components in the analyzed materials.
A Simple Way to Upgrade a Compact Radiocarbon AMS Facility for 10Be
Authors: Müller Arnold Milenko , Suter Martin , Fu Dongpo , Ding Xingfang , Liu Kexin , Synal Hans-Arno , Zhou Liping
Published: January 2017

A simple way to upgrade the Peking University 500kV NEC radiocarbon facility (CAMS) for 10Be measurements is presented. In a first phase, a silicon nitride foil as passive boron degrader was mounted in front of the electrostatic deflector near the focal plane of 10Be. The Si detector at the end of the beam line was replaced with a high-resolution ΔE-Eres gas ionization chamber. In addition, a Faraday cup for the measurement of 9Be1+ was installed. Tests with this arrangement showed promising results: a 10Be/9Be background level of 3.4 × 10–14 and an overall transmission for 10Be of 2.2% were obtained. Measurements of standards showed very good stability and reproducibility. In the next step, it is planned to add a second magnet to reduce the background and to partly compensate losses due to energy and angular straggling in the degrader foil by the energy and angular refocusing effect of a magnetic sector field. With this final arrangement, a performance with 10Be/9Be background levels at 10−15 and 10Be overall transmission of 6–7% can be expected. The design proposed in this paper has the advantage that the modifications can be realized in a rather inexpensive way and that the measurement performance for 14C will not be affected.
Data Analysis at the Jena 14C Laboratory
Authors: Steinhof Axel
Published: January 2017

The Jena Analysis Code (JAC) was developed at the Jena radiocarbon laboratory for the analysis of all 14C accelerator mass spectrometry (AMS) data measured there. The fundamental principles and algorithms of JAC are presented here, along with the equally important checking procedures. JAC places emphasis on the uncertainty due to background subtraction and other contributions to the statistical uncertainty of 14C events.
Radiocarbon Dating of Historical Parchments
Authors: Brock Fiona
Published: January 2017

A range of pretreatment methods was applied to 6 known-age historical parchments to investigate the most suitable methods for effectively removing contamination and ensuring accurate radiocarbon dates while minimizing unnecessary destruction of potentially valuable historical documents. The methods tested included an acid wash, different concentrations of acid-base-acid (ABA) pretreatments, the current routine ABA method applied at the Oxford Radiocarbon Accelerator Unit (ORAU) that includes an additional bleach treatment, and extraction of collagen. The C:N atomic weight ratio of the untreated and pretreated parchment fractions was observed to be a useful indicator of the presence or successful removal of contaminants. The pretreatment methods that produced the most accurate 14C dates and acceptable C:N ratios were found to be ABA protocols (without bleach) and collagen extraction; solvent washes and acid pretreatments alone were not sufficient to remove all contaminants and produce reliable 14C dates. The inclusion of a base wash did not affect the 14C dates of the samples, but did favorably influence the C:N ratio of the final product.
Storage and Hydrolysis of Seawater Samples for Inorganic Carbon Isotope Analysis
Authors: Bryant Charlotte L , Henley Sian F , Murray Callum , Ganeshram Raja S , Shanks Richard
Published: January 2017

Preservation of seawater samples was tested for total inorganic carbon (∑CO2), stable carbon isotope (δ13C), and radiocarbon (14C) applications using foil bags and storage by refrigeration and freezing. The aim was to preserve representative samples with minimal storage effects but without using toxic methods such as mercuric chloride poisoning. Hydrolysis of samples to CO2 was based on existing methods. Results of IAEA-C2 standard used with deionized water stored in the foil bags showed complete reaction yields, 14C results within 2σ of the consensus value, and δ13C that were internally consistent, indicating that there were no procedural effects associated with the foil bags. 14C results were statistically indistinguishable across the storage times, for frozen and refrigerated seawater samples from a coastal site, Elie Ness, Fife, UK. The scatter of ∑CO2 concentrations and δ13C was within scatter observed in other studies for lake- and seawater samples preserved by acidification or using mercuric chloride. However, both ∑CO2 and δ13C were less variable for frozen samples compared with refrigerated samples. The foil bags are lighter, safer to transport, and similar in cost to glass bottles and allow sample collection in the field and transfer to the hydrolysis vessel without exposure of the sample to atmosphere. Storage of seawater samples in the foil bags was considered a reliable, alternative method to poisoning for ∑CO2, δ13C, and 14C, and freezing the samples is recommended for storage time beyond a week.
Non-Destructive Portable Analytical Techniques for Carbon In Situ Screening Before Sampling for Dating Prehistoric Rock Paintings
Authors: Beck Lucile , Genty Dominique , Lahlil Sophia , Lebon Matthieu , Tereygeol Florian , Vignaud Colette , Reiche Ina , Lambert Elsa , Valladas Hélène , Kaltnecker Evelyne , Plassard Frédéric , Menu Michel , Paillet Patrick
Published: January 2017

Direct dating of prehistoric paintings is playing a major role in Paleolithic art studies. Very few figures can be directly dated since the necessary condition is that they contain organic carbon-based material. Thus, it is very important to check the presence of organic carbon-based material in situ before sampling in order to protect the visual integrity of the paintings or drawings. We have tested and compared 3 different portable analytical systems that can be used in cave environments for detecting carbon in prehistoric paintings: (1) a very compact X-ray fluorescence (XRF) system in Villars Cave (Dordogne, France); (2) a portable micro-Raman spectrometer in Rouffignac Cave (Dordogne, France); and (3) an infrared reflectography camera in both caves. These techniques have been chosen for their non-destructiveness: no sample has to be taken from the rock surface and no contact is made between the probes and the paintings or drawings. The analyses have shown that all the animal figures have been drawn with manganese oxides and cannot be directly dated by radiocarbon. However, carbon has been detected in several spots such as black dots and lines and torch marks. 14C results were obtained from 5 torch marks selected in Villars Cave, with ages between 17.1–18.0 ka cal BP. Three methods were used to identify carbon in black pigments or to confirm the presence of torch marks by carbon detection. Thanks to these new analytical developments, it will be now possible to select more accurately the samples to be taken for 14C dating prehistoric paintings and drawings.
Analysis of Bone “Collagen” Extraction Products for Radiocarbon Dating
Authors: Brock F , Geoghegan V , Thomas B , Jurkschat K , Higham T F G
Published: January 2017

Archaeological bones are now routinely dated in many radiocarbon laboratories through the extraction of “collagen.” Methods for “collagen” extraction vary, and several laboratories now apply an ultrafiltration step after gelatinization to extract the higher molecular weight (usually >10 or 30kDa) fraction for dating, thereby removing low molecular weight contaminants. Ultrafiltration has been demonstrated to result in products that are easier to handle and have more acceptable C:N ratios, and in some instances can result in significantly improved (generally older) 14C dates when compared to non-ultrafiltered products from the same bone. Although it has been suggested that ultrafiltration removes potential contaminants such as short-chain degraded collagen and other peptides and amino acids, fulvic acids, and salts, there remains little published evidence to support this. This paper presents data from a pilot study investigating the most suitable techniques with which to study the products of the routine “collagen” extraction procedures employed at the Oxford Radiocarbon Accelerator Unit (ORAU) (modified Longin followed by ultrafiltration). The preliminary data demonstrates that the final product of “collagen” extraction at ORAU appears to be an aggregate consisting of a range of proteins of different molecular weights, including collagen, as well as some other organic matter and inorganic species. Ultrafiltration is removing some, but not all, of the <30kDa fraction from the samples. Further work to investigate the nature of this aggregate and how best to improve the efficiency of “collagen” extraction procedures is discussed.
Ultrafiltration Pretreatment for 14C Dating of Fossil Bones from Archaeological Sites in Japan
Authors: Minami M , Sakata K , Takigami M , Nagaoka T , Nakamura T
Published: January 2017

To study the effect of ultrafiltration on the radiocarbon ages of relatively poorly preserved bones in Japan, we analyzed the 14C dates of high-molecular-weight (HMW) gelatin samples and compared them with those of other extracted organic fractions, unfiltered gelatin samples extracted from NaOH-treated or NaOH-untreated collagen, and XAD-purified hydrolysates of animal fossil bones (∼4600 BP; gelatin yield of 2–4%) from the Awazu underwater archaeological site, Shiga, Japan. NaOH-treated, unfiltered gelatins and XAD-purified hydrolysates showed statistically similar 14C ages to those of HMW gelatins. The 14C ages of the HMW gelatins were the oldest and similar to those of wood collected from the same layer as the bones, and the NaOH-treated, unfiltered gelatins gave 14C ages within the acceptable margins of error; therefore, ultrafiltration was effective for accurate 14C dating, while NaOH-treated gelatin without ultrafiltration was also sufficient to obtain accurate 14C dates on the animal bones. The 14C ages of human skeletons (∼750 BP; gelatin yield of 2–11%) from 5 individuals excavated from an archaeological site in Yuigahama, Kamakura, Japan, showed statistically the same 14C ages as NaOH-treated, unfiltered gelatins and HMW gelatins within the margins of error, although HMW gelatins were likely to give slightly older ages than unfiltered gelatin with a yield of less than ∼3%. These results indicate that unfiltered gelatins extracted from fossil bones of gelatin yield more than ∼3% can produce accurate 14C ages without the need for ultrafiltration. Ten bone fragments from 3 humans showed the same 14C ages for each individual, suggesting that any bone part from an individual can be used to obtain a representative age. The 14C ages of tooth enamels of 2 individuals were 35 and 70 yr older than their bone ages. Death dates obtained from these age gaps agreed with those determined by morphology.
Dating Gods: Radiocarbon Dates from the Sanctuary of Zeus on Mt. Lykaion (Arcadia, Greece)
Authors: Starkovich Britt M , Hodgins Gregory W L , Voyatzis Mary E , Romano David Gilman
Published: January 2017

This paper reports the results of the application of a calcined bone dating protocol to samples collected from the Sanctuary of Zeus on Mt. Lykaion in southern Greece. The site is a mountaintop ash altar rich in anthropogenic sediments, burned bone, and artifacts offered to the god Zeus. Experiments involving time series hydrolysis measurements were conducted on calcined bones from stratified layers throughout the sequence to determine if any of the samples underwent surface contamination from carbonate exchange with the surrounding sedimentary matrix. It was determined that such exchange was unlikely, but samples were acid-etched before pretreatment as a precautionary measure. Paired samples of seeds, charcoal, and calcined animal bone collected from a sediment column in the altar demonstrate the effectiveness of the calcined bone dating technique in this context. The results of dating indicate that the altar was in use from the Mycenaean period through the late Classical period, though samples were not collected from the upper levels of the site due to possible mixing of surface sediments. Fourier transform infrared spectroscopy (FTIR) measurements were taken and crystallinity index values calculated, confirming that the bone samples are indeed calcined. The results presented here correspond with literary accounts of ritual animal sacrifice from historical texts from the 8th century BCE, including the Homeric epics.
Low-Temperature and Temperature Stepped-Combustion of Terrace Sediments from Nanfu, Taiwan
Authors: Wang Shing-Lin , Burr George S , Chen Yue-Gau , Lin Yin , Wu Tzu-Shuan
Published: January 2017

We discuss a radiocarbon study of sediment samples collected from Nanfu terrace in western Taiwan. From these, we extracted humic acids (HA) and humin from the very fine and coarse grain-size fractions using a standard acid-alkali-acid pretreatment. The humin extracts were combusted at 400 and 1100 °C by stepped-combustion, to yield a low-temperature (LT) carbon component and a high-temperature (HT) carbon component. We compare the ages of the LT and HT humin fractions to the HA fractions, in samples collected at 2 depths within the Nanfu terrace. As in previous stepped-combustion studies on sediments, we find that the HA ages are the youngest on average, and overlap the LT ages, and that the carbon contained in the HT fraction is always distinctly older than the LT and HA ages. To better understand the relationship between 14C age and combustion temperature, we conducted an incremental stepped-combustion experiment with one of the samples (1E) using 50 °C steps that ranged from 300 to 1100 °C. The 14C results of the stepped-combustion products show a clear division between 2 isotopically identifiable carbon constituents, from carbon released below 400 °C and carbon released above 550 °C. By comparing the δ13C and 14C results, we find evidence for a third carbon isotopic component in the humin that is released when combusted at ∼500 °C.
A High-Throughput, Low-Cost Method for Analysis of Carbonate Samples for 14C
Authors: Roberts Mark L , Beaupré Steven R , Burton Joshua R
Published: January 2017

The National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at the Woods Hole Oceanographic Institution has developed an automated system for high-throughput, low-cost analysis of radiocarbon in carbonate samples (e.g. corals, carbonaceous sediments, speleothems, etc.). The method bypasses graphitization and pretreatment, and reduces costs to about 1/5th the price of a graphite-based 14C carbonate analysis, with a throughput of 60 unknowns per day and an analytical precision of better than 2%. Additionally, a simple mixing experiment indicated that extensive cleaning of carbonate samples to remove organic material is not necessary.
14C Dating of Humic Acids from Bronze and Iron Age Plant Remains from the Eastern Mediterranean
Authors: Wild E M , Steier P , Fischer P , Höflmayer F
Published: January 2017

Radiocarbon dating of plant remains is often difficult due to the complete dissolution of the samples in the alkaline step of the ABA pretreatment. At the VERA laboratory, this problem was encountered frequently when numerous Bronze and Early Iron Age samples from the eastern Mediterranean were dated in the course of the special research program SCIEM2000 and in other collaborations with archaeologists focused on that area and time period. For these samples, only a 14C age determination of the humic acid fraction was possible. Humic acids from archaeological samples are always assessed as a second-choice material for 14C dating. It is assumed that the 14C ages may be affected by the presence of humic acids originating from other (younger) organic material, e.g. from soil horizons located above a sample. Therefore, when humic acids are dated a verification of the dates is crucial. To address this basic requirement, we started some time ago to date both fractions of charred seeds, wood, and charcoal samples whenever available, i.e. the residue after the ABA treatment and the humic acids extracted from the samples in the alkaline step. The results of this comparison showed that for the investigated eastern Mediterranean archaeological sites, 50 (out of 52) humic acid dates were in agreement with the 14C dates of the respective ABA-treated samples. Statistical analysis of the age differences leads to the conclusion that the extracted humic acids originated from the samples themselves or from contemporaneous material and were not appreciably contaminated by extraneous material of different age.