222 research outputs found

    Oceanic distribution of inorganic germanium relative to silicon: Germanium discrimination by diatoms

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    Seventeen inorganic germanium and silicon concentration profiles collected from the Atlantic, southwest Pacific, and Southern oceans are presented. A plot of germanium concentration versus silicon concentration produced a near-linear line with a slope of 0.760 × 10−6 (±0.004) and an intercept of 1.27 (±0.24) pmol L−1 (r2 = 0.993, p < 0.001). When the germanium-to-silicon ratios (Ge/Si) were plotted versus depth and/or silicon concentrations, higher values are observed in surface waters (low in silicon) and decreased with depth (high in silicon). Germanium-to-silicon ratios in diatoms (0.608–1.03 × 10−6) and coupled seawater samples (0.471–7.46 × 10−6) collected from the Southern Ocean are also presented and show clear evidence for Ge/Si fractionation between the water and opal phases. Using a 10 box model (based on PANDORA), Ge/Si fractionation was modeled using three assumptions: (1) no fractionation, (2) fractionation using a constant distribution coefficient (KD) between the water and solid phase, and (3) fractionation simulated using Michaelis-Menten uptake kinetics for germanium and silicon via the silicon uptake system. Model runs indicated that only Ge/Si fractionation based on differences in the Michaelis-Menten uptake kinetics for germanium and silicon can adequately describe the data. The model output using this fractionation process produced a near linear line with a slope of 0.76 × 10−6 and an intercept of 0.92 (±0.28) pmol L−1, thus reflecting the oceanic data set. This result indicates that Ge/Si fractionation in the global ocean occurs as a result of subtle differences in the uptake of germanium and silicon via diatoms in surface waters

    The effects of different arsenic species in relation to straighthead disease in rice

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    The effects of inorganic arsenic on plants, the mechanisms involved in the uptake and transport of arsenic and how inorganic arsenic enters food chains are well documented. Regulatory limits have been established to control the inorganic arsenic concentrations in certain foods including rice. There is, however, a knowledge gap with respect to dimethylarsenic concentrations. In this study rice was grown hydroponically and exposed to varying DMA concentrations. High levels of DMA were detrimental to rice plants whereby plants showed symptoms consistent with Straighthead disease, a disease that results in dramatic yield losses.Australian Government ResearchTraining Program ANU OCG Travel Scholarshi

    The Ursinus Weekly, October 12, 1964

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    Thespians choose Blore & Rodimer, Fall cast leads: Write me a murder heads into first stage of production • Pledging begins as sororities end last week of rushing: 61 women sign bids • Queen Jeanne Dawson, grid triumph, flavor weekend fun: Returning alumni enjoy cold day\u27s festivities • Lancaster theologian speaking tonight on Vatican Council II • Pre-meds hear members, list season speakers • Peace Corps worker to speak here • Y adds new concept to traditional retreat format: Fernbrook site of weekend\u27s activities • Editorial: Apathy or futility • Green poncho raincoats become UC fetish • UC students see touring Goldwater • Democrats meet the candidates • Young Republicans hold first caucus • Kaffee Klatch drafts variety • Human Relations Club begins work • Bears eat-up Blue Jays 38-22, exciting second half: Degenhardt wins Walker Memorial • Beta Sig, Seals lead leagues • Soccer team ties East Baptist, 2-2 • UC soccer team outplays alumni • J.V. hockey team victorious in first two season games: Crush Gwynedd 6-1, line scores at will; Defense stalwart defeat tough Penn • Answers and questions • Dear Ursala: advice column • Greek gleaningshttps://digitalcommons.ursinus.edu/weekly/1229/thumbnail.jp

    Transparency at the parish pump: a field experiment to measure the effectiveness of freedom of information requests in England

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    How effective are systems of transparency, such as Freedom of Information (FOI) requests? The ambitious aims of FOI laws hinge on whether requests produce the desired information for the citizens or groups that use them. The question is whether such legally mandated requests work better than more informal mechanisms. Despite the high hopes of advocates, organizational routines, lack of awareness or resistance may limit legal access and public bodies may seek to comply minimally rather than behave in concordance with the spirit of the law. This article reports a field experiment that compared FOI requests and informal nonlegal asks to assess which is more effective in accessing information from English parish councils. The basic premise of statutory access is borne out. FOI requests are more effective than simple asks and the size or preexisting level of openness of a body appears to make little difference to their responsiveness. FOI requests are more effective in encouraging bodies to do more than the law asks (concordance) than encouraging more minimal levels of legal cooperation, when a body simply fulfills its obligations to varying degrees (compliance).This finding indicates high levels of support for FOI once it is within the system

    De quelques catéchismes créoles anciens: oublis, pertes, disparitions, réapparitions, découvertes

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    Il existe, dans le très vaste domaine des études postcoloniales, des territoires contigus ou semblables qui connaissent des phénomènes communs mais aux histoires très différentes, sinon radicalement opposées : tels les catéchismes - en langues romanes - fruit de la colonisation. Plus précisément, à l’histoire des catéchismes issus de la colonisation hispano-américaine, s’oppose l’histoire des catéchismes issus de la colonisation française, de l’Amérique et d’ailleurs. Ces derniers arrivent un siècle et demi environ après les espagnols et se manifestent de tout autre manière ; différents en sont l’époque, la scène et les acteurs : les destinateurs mais surtout les destinataires. Ce travail se propose de retracer l’histoire souvent aventureuse des plus anciens catéchismes des colonies ou ex-colonies françaises de la Caraïbe et de l’Océan Indien ; écrits en créole ou, parfois, en d’autres langues autochtones, ils constituent aussi des témoignages linguistiques absolument précieux. Rédigés généralement sur place, mais non toujours publiés, leur histoire est faite d’oublis, pertes, disparitions, réapparitions et découvertes. - - - In the wide field of postcolonial studies, there exist related or similar areas whose stories are nevertheless very different, if not indeed opposed. This is the case of catechisms in Romance languages (or of Romance origin), outcomes of European colonization. In particular, contradictions between the history of catechisms from Hispanic-American colonization and the catechisms produced by French colonization, in America and elsewhere. The latter appear a century and a half after the Spanish texts, and exhibit completely distinct characteristics: different periods, settings, actors, and especially recipients. I set out to recount the often adventurous history of the oldest catechisms in the French colonies, or ex-colonies, of the Caribbean and the Indian Ocean. Written in Creole or sometimes other indigenous languages, they are precious linguistic records. Compiled in the colonies, but not always published, these texts are often forgotten, lost, misplaced, resurfaced, discovered

    Membrane Sigma-Models and Quantization of Non-Geometric Flux Backgrounds

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    We develop quantization techniques for describing the nonassociative geometry probed by closed strings in flat non-geometric R-flux backgrounds M. Starting from a suitable Courant sigma-model on an open membrane with target space M, regarded as a topological sector of closed string dynamics in R-space, we derive a twisted Poisson sigma-model on the boundary of the membrane whose target space is the cotangent bundle T^*M and whose quasi-Poisson structure coincides with those previously proposed. We argue that from the membrane perspective the path integral over multivalued closed string fields in Q-space is equivalent to integrating over open strings in R-space. The corresponding boundary correlation functions reproduce Kontsevich's deformation quantization formula for the twisted Poisson manifolds. For constant R-flux, we derive closed formulas for the corresponding nonassociative star product and its associator, and compare them with previous proposals for a 3-product of fields on R-space. We develop various versions of the Seiberg-Witten map which relate our nonassociative star products to associative ones and add fluctuations to the R-flux background. We show that the Kontsevich formula coincides with the star product obtained by quantizing the dual of a Lie 2-algebra via convolution in an integrating Lie 2-group associated to the T-dual doubled geometry, and hence clarify the relation to the twisted convolution products for topological nonassociative torus bundles. We further demonstrate how our approach leads to a consistent quantization of Nambu-Poisson 3-brackets.Comment: 52 pages; v2: references adde
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