Absorbed Mn2+ and Mn redox cycling in Iberian continental margin sediments (northeast Atlantic Ocean)

Although Mn2+ sorption has been investigated extensively in the laboratory, the role of Mn2+ sorption in natural marine sediments remains speculative. Our objectives were to study (1) the role of Mn2+ sorption in the redox cycling of Mn, (2) to quantify Mn cycling and (3) to identify its rate-determining factors at the Iberian margin. Profiles of pore water Mn2+, adsorbed Mn2+ and solid phase Mn were measured together with benthic oxygen fluxes along three transects across the margin from the shelf to the deep sea as well as in the Nazeré Canyon. In the profiles, peaks of adsorbed Mn2+ were observed in-between those of solid phase Mn and pore water Mn2+. We propose that upon Mn reduction, the produced Mn2+ is adsorbed onto adjacent Mn oxide or oxyhydroxide surfaces. Available adsorption-sites diminish and/or saturate as Mn reduction continues, upon which Mn2+ is released into the pore water. Mn redox chemistry is controlled by the organic carbon flux to the sediment. A simple steady state model was formulated that includes Mn2+ sorption as a combination of an instantaneous reversible equilibrium process and a first-order kinetic reaction. Model derived, depth integrated rates of Mn reduction as well as Mn2+ desorption and oxidation rates range between 1 and 35 µmoles m-2 d-1. Mn cycling is most intense at moderate carbon fluxes. Moreover, Mn cycling is enhanced at higher deposition fluxes of Mn oxide in the canyon. Budgets based on the model indicate that adsorbed Mn2+ is an important redox intermediate between Mn oxide and pore water Mn2+ in the reduced sediment layer. Adsorption of Mn2+ restrains the efflux of dissolved Mn2+ into the water column, by lowering the pore water gradient at stations with a thin oxidation zone. There, adsorbed Mn2+ enhances the retention of Mn2+ in the sediment column

Coccolithophorid calcium carbonate dissolution in surface waters

The role of calcifying organisms in the ocean biogeochemistry has been receiving increasing attention since CO2-related global change issues such as ocean acidification were pointed out by the scientific community. The implications of changing oceanic pH in modifying ecosystems dominated by planktonic calcifiers have been shown by mesocosm and laboratory experiments based on CO2 manipulations. The major concern of such experiments focussed on variations in the rates of ecosystem primary production and calcification due to changes in algal physiology or specific composition. Our results, from an interdisciplinary survey of coccolithophore-dominated blooms in the northern Bay of Biscay (NE Atlantic), suggest that biogenic calcite dissolution is occurring in the photic zone where surface waters are oversaturated with respect to calcite. The dissolution of CaCO3 in surface waters, evidenced by scanning electron microscopy observations, has an impact on the preservation and export of carbon in coccolithophore-dominated ecosystems and on the exchange of CO2 across the ocean-atmosphere interface. Both aspects of suspended calcite concentration reduction in natural environments (lower rates of production or dissolution) could be considered as a perturbation of the oceanic carbon cycle. We aim at presenting here a biogeochemical description of processes, including integrated primary production, calcification, and parameters such as transparent exopolymer particles concentration and particulate inorganic carbon profiles, during field studies. A mechanism for calcite dissolution, based on biological activity in microenvironments (including grazing, bacterial respiration and DMS production) is presented as a conceptual model in coccolithophore blooms

Ethical decision-making in biopharmaceutical research and development: applying values using the TRIP & TIPP model

“Values-based decision-making” frameworks and models are widely described in the literature in various disciplines, including healthcare settings. However, there is a paucity of literature on the application of systematic methods or models in the biopharmaceutical research and development (R&D) field of drugs, vaccines, and immunotherapeutics. In this report, we describe our model that uses company values along with framing questions in a five-step process to guide ethical decisions in the vaccines R&D context. The model uniquely supports practical prospective decision-making: employees are engaged as moral agents applying values and principles to guide their decision in a specific situation. We illustrate, by way of case studies, how the model is being used in practice. The consistent application of company values during decision-making calls upon employees to use their judgment, therefore reducing the need for the organization to systematically generate written instructions. Finally, we report on preliminary results of model adoption by teams within our organization, discuss its limitations and likely future contribution. We applied our model within a vaccines R&D context and believe its use can be extended to other areas where business-related decisions impact patients

Recommendations for the ethical conduct of vaccination awareness campaigns by biopharmaceutical companies

Health awareness campaigns educate and inform the public about particular health conditions with the aim of either changing behavior or enhancing uptake of appropriate healthcare, such as vaccination or screening. The campaigns may be run by governments and public health bodies but are also deployed by biopharmaceutical companies. Industry-sponsored disease awareness (DA) campaigns intend to provide information about diseases and their prevention or treatment, without mentioning specific products. In most countries, DA campaigns fall outside of the laws and regulations that apply to promotion of medicines. Currently, guidance for industry is limited and only exists at national level. This article provides an overview of existing guidance on DA campaigns, discusses benefits and risks, and proposes recommendations for industry-sponsored vaccination awareness campaigns

Dissolved Inorganic Carbon dynamics in the northern Bay of Biscay during a Coccolithophore bloom

In the framework of the Belgian global change programme, we have developed a project devoted to the study of the inorganic carbon cycle in the Bay of Biscay where coccolithophore blooms occur frequently. The study focuses on processes associated with the oceanic production and dissolution of calcium carbonate and related CO2 fluxes. Real time remote sensing allowed to localize the coccolithophore bloom that the R.V. Belgica visited in June 2004 during a multidisciplinary scientific cruise. We will present vertical profiles of pH, Talk, along with other parameters (salinity, temperature, chlorophyll a and phaeopigments) and 14C incorporation experiments. Inorganic carbon fluxes will be discussed in the photic zone, in correlation with the biological activity of phytoplankton (biological and carbonate pumps)

Biogeochemical Cycling Of Carbon, Nitrogen And Phosphorus In The North Sea - CANOPY- Final report

Biogeochemical Cycling Of Carbon, Nitrogen And Phosphorus In The North Sea - CANOPY- Final report The CANOPY project aimed to determine the importance of the internal cycling processes of uptake and regeneration of carbon, nitrogen and phosphorus in the Southern Bight of the North Sea (SBNS), a marine area receiving riverine inputs from the Scheldt and Rhine rivers and influenced by inflowing English channel waters. The SBNS area was characterized by the presence of 2 large coastal river plumes with high levels of nutrients, and a central part with lower nutrient levels. Dissolved inorganic N (DIN and P (DIP) levels varied seasonally and were minimal for highest phytoplankton biomass, in spring and late summer. Additionally, organic N and P represented important fractions of the total N and P. In the central waters, dissolved organic N (DON), P (DOP) and particulate organic P (POP) dominated the N and P pools in summer, but their relative importance was more limited in the river plumes. For the pelagic system, DIC, DIN and DIP varied seasonally and were highest during the spring phytoplankton bloom, and for some stations, at the end of the summer phytoplankton bloom. Additionally, the uptake of DIN and primary production (PP) were well correlated with a C:N ratio of 6.5 very close to the Redfield ratio. In general, the regeneration of DIN largely exceeded the uptake except in spring, where a more balanced situation was observed. The regeneration of DIP also represented a large fraction of the DIP uptake. Heterotrophic processes are thus very active in the SBNS. They clearly dominate the pelagic N cycling, and are in balance with uptake processes for DIP. At ecosystem scale, it was demonstrated that the Scheldt plume was net heterotrophic during most years and acted as an important source of CO2 for the atmosphere. In contrast, the Scheldt plume also acted as an active sink for both DIN and DIP probably due to active denitrification and physical adsorption processes in this organic matter and SPM rich environment. In contrast, the central waters were on the yearly average autotrophic and acted as a sink for CO2. Again in contrast, there was a net production of DIN and DIP. The comparison of DIN and DIP budgets with DIC budgets showed that correlations exist but were not straightforward. In general, correlations showed a C:N ratio of 3.5 (<Redfield) and a C:P ratio of 109 (=Redfield). This suggests that whatever the season there is a DIC production sustained by OM with a high C:N ratio, either of terrestrial (estuarine) origin or from the sediment. This is agreement with the fact that consumption of DIC by PP exceeds the net ecosystem DIC production. The other possible cause is a large removal of DIN by denitrification in agreement with the fact that net pelagic DIN production largely exceeds net ecosystem DIN production. However, the correlation lines did not pass through 0 showing that primary production and respiration are not the only players in the DIC-DIN-DIP dynamics with the presence of unrelated DIC, DIN and DIP sources our sinks.CANOP

Time series of the partial pressure of carbon dioxide (2001-2004) and preliminary inorganic carbon budget in the Scheldt plume (Belgian coastal waters)

A 4-year time series (2001–2004) of the partial pressure of CO2 (pCO2) and air-sea CO2 fluxes is reported in the Scheldt estuarine plume. This system is oversaturated in CO2 with respect to the atmosphere, except during the spring phytoplanktonic bloom, and acts as a net source of CO2 to the atmosphere of 0.7 mol C m-2 yr-1 that represents 7 to 27% of the inner Scheldt estuary CO2 emission. Results also highlight that a high spatial and temporal coverage of the surface pCO2 in coastal ecosystems is crucial for reliable estimations of air-sea CO2 fluxes. The seasonal variations of pCO2 seem to be more dominated by biological activities (photosynthesis/respiration) than by temperature change. A stochiometrically linked C/P mass balance budget failed to provide net ecosystem production estimates consistent with the pCO2 dynamics in this area. It is hypothesized that this discrepancy is related to physiological characteristics of the dominant phytoplanktonic species (Phaeocystis sp.) within the studied area. On the basis of a preliminary dissolved inorganic carbon input/output budget, the annual emission of CO2 toward the atmosphere seems to be largely due to the outgassing of the inputs of CO2 from the inner Scheldt estuary, rather than due to organic carbon degradation. [KEYWORDS: CO2 air-sea fluxes ; Belgian coastal water; Scheldt estuary.]