Quantification and molecular characterization of dissolved organic sulfur in water samples obtained during POLARSTERN cruise ANT-XXV (PS73) to the East Atlantic and the Southern Ocean

Although sulfur is an essential element for marine primary production and critical for climate processes, little is known about the oceanic pool of non-volatile dissolved organic sulfur (DOS). We present a basin-scale distribution of solid phase extractable DOS in the East Atlantic Ocean and the Atlantic sector of the Southern Ocean. While molar DOS versus dissolved organic nitrogen (DON) ratios of 0.11 ± 0.024 in Atlantic surface water resembled phytoplankton stoichiometry (S/N ~ 0.08), increasing dissolved organic carbon (DOC) versus DOS ratios and decreasing methionine-S yield demonstrated selective DOS removal and active involvement in marine biogeochemical cycles. Based on stoichiometric estimates, the minimum global inventory of marine DOS is 6.7 Pg S, exceeding all other marine organic sulfur reservoirs by an order of magnitude.

The gap between recognition and the 'compensation business' : the claim against Britain for compensation by Kenya's former Mau Mau fighters

During the first Kibaki administration (2002-2007), a movement by the former Mau Mau fighters demanded recognition for the role that they had played in the achievement of independence. They began to demand, also, monetary compensation for past injustices. Why had it taken over 40 years (from independence in 1963) for the former Mau Mau fighters to initiate this movement? What can be observed as the outcome of their movement? To answer these questions, three different historical currents need to be taken into account. These were, respectively, changing trends in the government of Kenya, progress in historical research into the actual circumstances of colonial control, and a realization, based on mounting experience, that launching a legal action against Britain could turn out to be a lucrative initiative. This paper concludes that, regardless of the actual purpose of the legal case, neither of their objectives was certain to be achieved. Two inescapable realities remain: the doubts cast on the reputation of the government by its decision to lift the Mau Mau‟s outlaw status – a decision that was widely seen as a latter-day example of the „Kikuyu favouritism‟ policy followed by the first Kibaki administration – and the popular interpretation of the involvement of Leigh Day, well known in Kenya ever since the unexploded bombs case for its success in obtaining substantial compensation payments, as a vehicle for squeezing large amounts of money from the British government for the benefit of the Kikuyu people.

O EVANGELHO SEGUNDO DOSTOIÉVSKI UMA ABORDAGEM INTERTEXTUAL DA IMAGEM DE CRISTO NO ROMANCE O IDIOTA

No romance O Idiota, Dostoiévski cria, por meio do príncipe Míchkin, uma personagem com as características do Cristo. Sabe-se que a Bíblia, principalmente o Novo Testamento, acompanhou o escritor desde sua infância até o momento de sua morte. O primeiro capítulo, dedicado ao referencial teórico da pesquisa, lida com o universo da linguagem. Tanto o texto literário quanto a literatura bíblica procedem do mito. Neste sen-tido, religião e literatura se tocam e se aproximam. O segundo capítulo foi escrito na intenção de mostrar como o Cristo e os Evangelhos são temas, motivos e imagens recorrentes na obra de Dostoiévski. A literatura bíblica está presente, com mais ou menos intensidade, em diversas das principais obras do escritor russo e não somente em O Idiota. A hipótese de que Dostoiévski cria um Cristo e um Evangelho por meio de O Idiota é demonstrada na análise do romance, no terceiro capítulo. A tese proposta é: Dostoiévski desenvolve um evangelho literário, por meio de Míchkin, misto de um Cristo russo, ao mesmo tempo divino e humano, mas também idiota e quixotesco. Na dinâmica intertextual entre os Evangelhos bíblicos e O Idiota, entre Cristo e Míchkin, a literatura e o sagrado se revelam, como uma presença divina. Nas cenas e na estruturação do enredo que compõe o romance, Cristo se manifesta nas ações de Míchkin, na luz, na beleza, mas também na tragicidade de uma trajetória deslocada e antinômica. O amor e a compaixão ganham forma e vida na presen-ça do príncipe, vazio de si, servo de todos.

Quantifying pursuit-diving seabirds’ associations with fine-scale physical features in tidal streamenvironments

Acknowledgements James J. Waggitt was funded by a NERC Case studentship supported by OpenHydro Ltd and Marine Scotland Science (NE/J500148/1). Vessel-based transects were funded by a NERC (NE/J004340/1) and a Scottish National Heritage (SNH) grant. FVCOM modelling was funded by a NERC grant (NE/J004316/1). Marine Scotland Science provided time on the FRV Alba-na-Mara as part as the Marine Collaboration Research Forum (MarCRF). The bathymetry data used in hydrodynamic models (HI 1122 Sanday Sound to Westray Firth) was collected by the Maritime & Coastguard Agency (MCA) as part of the UK Civil Hydrography Programme. We wish to thank Christina Bristow, Matthew Finn and Jennifer Norris at the European Marine Energy Centre (EMEC); Marianna Chimienti, Ciaran Cronin, Tim Sykes and Stuart Thomas for performing vessel-based transects; Marine Scotland Science staff Eric Armstrong, Ian Davies, Mike Robertson, Robert Watret and Michael Stewart for their assistance; Shaun Fraser, Pauline Goulet, Alex Robbins, Helen Wade and Jared Wilson for invaluable discussions; Thomas Cornulier, Alex Douglas, James Grecian and Samantha Patrick for their help with statistical analysis; and Gavin Siriwardena, Leigh Torres, Mark Whittingham and Russell Wynn for their constructive comments on earlier versions of this manuscript.

Substitution of a mutant α2a-adrenergic receptor via “hit and run” gene targeting reveals the role of this subtype in sedative, analgesic, and anesthetic-sparing responses in vivo

Norepinephrine contributes to antinociceptive, sedative, and sympatholytic responses in vivo, and α2 adrenergic receptor (α2AR) agonists are used clinically to mimic these effects. Lack of subtype-specific agonists has prevented elucidation of the role that each α2AR subtype (α2A, α2B, and α2C) plays in these central effects. Here we demonstrate that α2AR agonist-elicited sedative, anesthetic-sparing, and analgesic responses are lost in a mouse line expressing a subtly mutated α2AAR, D79N α2AAR, created by two-step homologous recombination. These functional changes are accompanied by failure of the D79N α2AAR to inhibit voltage-gated Ca2+ currents and spontaneous neuronal firing, a measure of K+ current activation. These results provide definitive evidence that the α2AAR subtype is the primary mediator of clinically important central actions of α2AR agonists and suggest that the D79N α2AAR mouse may serve as a model for exploring other possible α2AAR functions in vivo.

Phosphorylated Human Keratinocyte Ornithine Decarboxylase Is Preferentially Associated with Insoluble Cellular Proteins

Ornithine decarboxylase (ODC), the first enzyme in polyamine biosynthesis, is highly regulated by many trophic stimuli, and changes in its levels and organization correlate with cytoskeletal changes in normal human epidermal keratinocytes (NHEK). NHEK ODC exhibits a filamentous perinuclear/nuclear localization that becomes more diffuse under conditions that alter actin architecture. We have thus asked whether ODC colocalizes with a component of the NHEK cytoskeleton. Confocal immunofluorescence showed that ODC distribution in NHEK was primarily perinuclear; upon disruption of the actin cytoskeleton with cytochalasin D, ODC distribution was diffuse. The ODC distribution in untreated NHEK overlapped with that of keratin in the perinuclear but not cytoplasmic area; after treatment with cytochalasin D, overlap between staining for ODC and for keratin was extensive. No significant overlap with actin and minimal overlap with tubulin filament systems were observed. Subcellular fractionation by sequential homogenizations and centrifugations of NHEK lysates or detergent and salt extractions of NHEK in situ revealed that ODC protein and activity were detectable in both soluble and insoluble fractions, with mechanical disruption causing additional solubilization of ODC activity (three- to sevenfold above controls). Fractionation and ODC immunoprecipitation from [32P]orthophosphate-labeled NHEK lysates showed that a phosphorylated form of ODC was present in the insoluble fractions. Taken together, these data suggest that two pools of ODC exist in NHEK. The first is the previously described soluble pool, and the second is enriched in phospho-ODC and associated with insoluble cellular material that by immunohistochemistry appears to be organized in conjunction with the keratin cytoskeleton.

Nicotianamine Chelates Both FeIII and FeII. Implications for Metal Transport in Plants1

Nicotianamine (NA) occurs in all plants and chelates metal cations, including FeII, but reportedly not FeIII. However, a comparison of the FeII and ZnII affinity constants of NA and various FeIII-chelating aminocarboxylates suggested that NA should chelate FeIII. High-voltage electrophoresis of the FeNA complex formed in the presence of FeIII showed that the complex had a net charge of 0, consistent with the hexadentate chelation of FeIII. Measurement of the affinity constant for FeIII yielded a value of 1020.6, which is greater than that for the association of NA with FeII (1012.8). However, capillary electrophoresis showed that in the presence of FeII and FeIII, NA preferentially chelates FeII, indicating that the FeIINA complex is kinetically stable under aerobic conditions. Furthermore, Fe complexes of NA are relatively poor Fenton reagents, as measured by their ability to mediate H2O2-dependent oxidation of deoxyribose. This suggests that NA will have an important role in scavenging Fe and protecting the cell from oxidative damage. The pH dependence of metal ion chelation by NA and a typical phytosiderophore, 2′-deoxymugineic acid, indicated that although both have the ability to chelate Fe, when both are present, 2′-deoxymugineic acid dominates the chelation process at acidic pH values, whereas NA dominates at alkaline pH values. The consequences for the role of NA in the long-distance transport of metals in the xylem and phloem are discussed.