Ultra-small graphitization reactors for ultra-microscale 14C analysis at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility

© The Arizona Board of Regents on behalf of the University of Arizona, 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Radiocarbon 57, no. 1 (2015): 109–122, doi:10.2458/azu_rc.57.18118.In response to the increasing demand for 14C analysis of samples containing less than 25 µg C, ultra-small graphitization reactors with an internal volume of ~0.8 mL were developed at NOSAMS. For samples containing 6 to 25 µg C, these reactors convert CO2 to graphitic carbon in approximately 30 min. Although we continue to refine reaction conditions to improve yield, the reactors produce graphite targets that are successfully measured by AMS. Graphite targets produced with the ultra-small reactors are measured by using the Cs sputter source on the CFAMS instrument at NOSAMS where beam current was proportional to sample mass. We investigated the contribution of blank carbon from the ultra-small reactors and estimate it to be 0.3 ± 0.1 µg C with an Fm value of 0.43 ± 0.3. We also describe equations for blank correction and propagation of error associated with this correction. With a few exceptions for samples in the range of 6 to 7 µg C, we show that corrected Fm values agree with expected Fm values within uncertainty for samples containing 6–100 µg C.This work was funded by the NSF Cooperative Agreement for the Operation of a National Ocean Sciences Accelerator Mass Spectrometry Facility (OCE-0753487). S R Shah Walter was also partially supported by the WHOI Postdoctoral Scholar Program

The U.S. Arctic Observing Viewer: A Web-Mapping Application for Enhancing Environmental Observation of the Changing Arctic

Although much progress has been made with various Arctic Observing efforts, assessing that progress can be difficult. What data collection efforts are established or underway? Where? By whom? To help meet the strategic needs of programs such as the U.S. Study of Environmental Arctic Change (SEARCH), the Arctic Observing Network (AON), Sustaining Arctic Observing Networks (SAON) and related initiatives, an update has been released for the Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org). This web mapping application and information system has begun to compile the who, what, where, and when for thousands of data collection sites (such as boreholes, ship tracks, buoys, towers, sampling stations, sensor networks, vegetation sites, stream gauges, and observatories) wherever marine, terrestrial, or atmospheric data are collected. Contributing partners for this collaborative resource include the U.S. NSF, ACADIS, ADIwg, AOOS, a2dc, AON, ARMAP, BAID, CAFF, IASOA, INTERACT, and others. While focusing on U.S. activities, the AOV welcomes information exchange with international groups for mutual benefit. Users can visualize, navigate, select, search, draw, print, and more. AOV is founded on principles of interoperability, with open metadata and web service standards, so that agencies and organizations can use AOV tools and services for their own purposes. In this way, AOV will reinforce and complement other distributed yet interoperable cyber-resources and will help science planners, funding agencies, researchers, data specialists, and others to assess status, identify overlap, fill gaps, optimize sampling design, refine network performance, clarify directions, access data, coordinate logistics, collaborate, and more in order to meet Arctic Observing goals.Malgré les progrès réalisés dans le cadre de nombreux efforts d’observation de l’Arctique, les progrès peuvent être difficiles à évaluer. Quelles initiatives de collecte de données sont en cours ou sont établies? À quel endroit? Et qui gère ces initiatives? Pour aider à répondre aux besoins stratégiques de programmes comme ceux de l’organisme américain Study of Environmental Arctic Change (SEARCH), du réseau Arctic Observing Network (AON), des réseaux Sustaining Arctic Observing Networks (SAON) et d’autres programmes connexes, on a procédé à la mise à jour de l’Arctic Observing Viewer (AOV; http://ArcticObservingViewer.org). Ce système d’information jumelé à une application de mappage sur le Web a amorcé la compilation des coordonnées et des renseignements se rapportant à des milliers de sites de collecte de données (comme les trous de forage, les trajets de navires, les bouées, les tours, les stations d’échantillonnage, les réseaux de capteurs, les sites de végétation, les fluviomètres et les observatoires) où des données marines, terrestres ou atmosphériques sont prélevées. Parmi les partenaires qui collaborent à cette ressource, notons U.S. NSF, ACADIS, ADIwg, AOOS, a2dc, AON, ARMAP, BAID, CAFF, IASOA, INTERACT et d’autres encore. Bien que l’AOV se concentre sur les activités américaines, il accepte l’échange d’information avec des groupes internationaux lorsqu’il existe des avantages mutuels. Les utilisateurs peuvent visualiser les données, naviguer dans le système, faire des sélections et des recherches, dessiner, imprimer et ainsi de suite. L’AOV fonctionne moyennant des principes d’interopérabilité, avec des métadonnées ouvertes et des normes de service sur le Web afin que les organismes et les organisations puissent utiliser les outils et les services de l’AOV pour leurs propres fins. De cette façon, l’AOV sera en mesure de consolider et de compléter d’autres cyberressources à la fois réparties et interopérables, en plus d’aider les planificateurs de la science, les bailleurs de fonds, les chercheurs, les spécialistes des données et d’autres encore à évaluer les statuts, à repérer les dédoublements, à combler les écarts, à optimiser les plans d’échantillonnage, à raffiner le rendement des réseaux, à clarifier les consignes, à accéder aux données, à coordonner la logistique, à collaborer et ainsi de suite afin de répondre aux objectifs d’observation de l’Arctique

Advances in Sample Preparation at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS): Investigation of Carbonate Secondary Standards

The development of robust sample preparation techniques for ocean science research has been a hallmark of NOSAMS since its inception. Improvements to our standard methods include reducing the minimum size of the samples we can analyze, building modular graphite reactors of different sizes that we can swap in and out depending on our sample stream, and modifying our carbonate acidification methods to improve handling of the smaller samples we now receive. A relatively new instrument, the Ramped PyrOx, which allows the separation of organic matter into thermal fractions, has attracted much interest as a research and development tool. We will also discuss our progress on incorporating a Picarro isotope analyzer into our sample preparation options

Connectivity within and among a Network of Temperate Marine Reserves

Networks of marine reserves are increasingly being promoted as a means of conserving marine biodiversity. One consideration in designing systems of marine reserves is the maintenance of connectivity to ensure the long-term persistence and resilience of populations. Knowledge of connectivity, however, is frequently lacking during marine reserve design and establishment. We characterise patterns of genetic connectivity of 3 key species of habitat-forming macroalgae across an established network of temperate marine reserves on the east coast of Australia and the implications for adaptive management and marine reserve design. Connectivity varied greatly among species. Connectivity was high for the subtidal macroalgae Ecklonia radiata and Phyllospora comosa and neither species showed any clear patterns of genetic structuring with geographic distance within or among marine parks. In contrast, connectivity was low for the intertidal, Hormosira banksii, and there was a strong pattern of isolation by distance. Coastal topography and latitude influenced small scale patterns of genetic structure. These results suggest that some species are well served by the current system of marine reserves in place along this temperate coast but it may be warranted to revisit protection of intertidal habitats to ensure the long-term persistence of important habitat-forming macroalgae. Adaptively managing marine reserve design to maintain connectivity may ensure the long-term persistence and resilience of marine habitats and the biodiversity they support

Re-reading William Morris re-writing the Peculiar Ardors of "Sigurd the Volsung"

There are a number of peculiarities about the British poet, William Morris's re-working of the Vølsunga Saga, published as a long poem in 1876. Some of these are wonderful, some are problematic, most of them are wonderful and problematic (I call the latter "ardors" for their capacity to raise emotional and/or critical temperatures, and for being linked to Morris' personal enthusiasms/obsessions and to the tempered command of his poetic craft). In my paper I will discuss three of those mixed categories, or ardors, towards a re-evaluation of the achievement of the poem. Morris's work on this poem closed out an intense period of translating Icelandic sagas with the collaboration of his Icelandic colleague, Eirikr Magnusson; but within his huge narrative anthology, *The Earthly Paradise* (1868), he first turned a prose saga into a Morris poem with "The Lovers of Gudrun" (based on the Laxdaela saga). Between that poem and *Sigurd* lay his two trips to Iceland, in 1871 and 1876, and for a variety of reasons the kind of poem he now wrote was considerably different from his first Norse "treatment." The questions I will deal with: (1) What does Morris's treatment show us about the literary and cultural "translatability" of this saga? (2) Why does Morris choose the language and the prosody that he does in "Sigurd" – and on what terms, if any, can they be defended? (3) Why is "Sigurd" the most special (peculiar) of his translations, and is this quality the result of spiritual and intellectual affinities with the Old Norse language and culture, or of his previously established "medievalism" with a politics and a poetics of its own? I will conclude with a re-evaluation of "Sigurd the Volsung," once well received (in England), and now, I think, largely relegated to the "storage" sections of libraries. I am inclined, partly for the fun of overstating a case, to argue that the *Sigurd* deserves to be described as among the true masterpieces of long English Victorian poems on medieval subjects – perhaps for as much as it does understand as fails to understand about the original saga