Sulfide enrichment at an oceanic crust-mantle transition zone : Kane Megamullion (23°N, MAR)

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 230 (2018): 155-189, doi:10.1016/j.gca.2018.03.027.The Kane Megamullion oceanic core complex located along the Mid-Atlantic Ridge (23°30′N, 45°20′W) exposes lower crust and upper mantle directly on the ocean floor. We studied chalcophile elements and sulfides in the ultramafic and mafic rocks of the crust-mantle transition and the mantle underneath. We determined mineralogical and elemental composition and the Cu isotope composition of the respective sulfides along with the mineralogical and elemental composition of the respective serpentines. The rocks of the crust-mantle transition zone (i.e., plagioclase harzburgite, peridotite-gabbro contacts, and dunite) overlaid by troctolites are by one order of magnitude enriched in several chalcophile elements with respect to the spinel harzburgites of the mantle beneath. Whereas the range of Cu concentrations in spinel harzburgites is 7–69 ppm, the Cu concentrations are highly elevated in plagioclase harzburgites with a range of 90–209 ppm. The zones of the peridotite-gabbro contacts are even more enriched, exhibiting up to 305 ppm Cu and highly elevated concentrations of As, Zn, Ga, Sb and Tl. High Cu concentrations show pronounced correlation with bulk S concentrations at the crust-mantle transition zone implying an enrichment process in this horizon of the oceanic lithosphere. We interpret this enrichment as related to melt-mantle reaction, which is extensive in crust-mantle transition zones. In spite of the ubiquitous serpentinization of primary rocks, we found magmatic chalcopyrites [CuFeS2] as inclusions in plagioclase as well as associated with pentlandite [(Fe,Ni)9S8] and pyrrhotite [Fe1−xS] in polysulfide grains. These chalcopyrites show a primary magmatic δ65Cu signature ranging from −0.04 to +0.29 ‰. Other chalcopyrites have been dissolved during serpentinization. Due to the low temperature (<300 °C) of circulating fluids chalcophile metals from primary sulfides have not been mobilized and transported away but have been trapped in smaller secondary sulfides and hydroxides. Combined with the Cu deposits documented in the crust-mantle transition zones of various ophiolite complexes, our results indicate that the metal enrichment, increased sulfide modes, and potentially formation of small sulfide deposits could be expected globally along the petrological Moho.This research was funded by a Diamond Grant of the Polish Ministry of Science and Higher Education (DI2012 2057 42 to J. Ciazela), and partly supported by grants of the U.S. National Science Foundation (OCE1434452 and OCE1637130 to H.J.B. Dick), and the German Science Foundation (Bo2941/4-1 to R. Botcharnikov)

An integer programming approach to support the US Air Force’s air mobility network

The United States Air Force’s air mobility command is responsible for creating a schedule and executing that schedule for a large-scale air mobility network that encompasses aircraft with prioritized missions. Aerial ports (airports) can process or park a maximum number of aircraft, called the maximum on ground (MOG). As the schedule changes due to disruptions, such as equipment failure or weather, the MOG constraint can cause the new schedule to be infeasible. Traditionally, re-planning the channel route schedule to adhere to MOG constraints has been a manual process that usually stops after the first feasible set of changes is found, due to the challenges of large amounts of data and urgency for a re-plan. We extend Bertsimas and Stock’s integer program formulation for the commercial airline Multi-Airport Ground-Holding Problem to the air mobility network. Our integer programming formulation recommends delays to certain aircraft on the ground to minimize the effects of system-wide disruptions while taking account mission priorities of the aircraft

Elimination of Organic Micropollutants in a Municipal Wastewater Treatment Plant Upgraded with a Full-Scale Post-Ozonation Followed by Sand Filtration

The removal efficiency for 220 micropollutants was studied at the scale of a municipal wastewater treatment plant (WWTP) upgraded with post-ozonation followed by sand filtration. During post-ozonation, compounds with activated aromatic moieties, amino functions, or double bonds such as sulfamethoxazole, diclofenac, or carbamazepine with second-order rate constants for the reaction with ozone >10(4) M-1 s(-1) at pH 7 (fastreacting) were eliminated to concentrations below the detection limit for an ozone dose of 0.47 g O-3 g(-1) dissolved organic carbon (DOC). Compounds more resistant to oxidation by ozone such as atenolol and benzotriazole were increasingly eliminated with increasing ozone doses, resulting in >85% removal for a medium ozone dose (similar to 0.6 g O-3 g(-1) DOC). Only a few micropollutants such as some X-ray contrast media and triazine herbicides with second-order rate constants 100 ng L-1. The combination of reaction kinetics and reactor hydraulics, based on laboratory and full-scale date, enabled a quantification of the results by model calculations. This conceptual approach allows a direct upscaling from laboratory- to full-scale systems and can be applied to other similar systems. The carcinogenic by-products N-nitrosodimethylamine (NOMA),(<= 14 ng L-1) and bromate (<10 mu g L-1) were produced during ozonation, however their concentrations were below or in the range of the drinking water standards. Furthermore, it could be demonstrated that biological sand filtration is an efficient additional barrier for the elimination of biodegradable compounds formed during ozonation such as NOMA. The energy requirement for the additional post-ozonation step is about 0.035 kWh m(-3), which corresponds to 12% of a typical medium-sized nutrient removal plant (5 g DOC m(-3))

Aggregation of Human Recombinant Monoclonal Antibodies Influences the Capacity of Dendritic Cells to Stimulate Adaptive T-cell Responses In Vitro

Subvisible proteinaceous particles which are present in all therapeutic protein formulations are in the focus of intense discussions between health authorities, academics and biopharmaceutical companies in the context of concerns that such particles could promote unwanted immunogenicity via anti-drug antibody formation. In order to provide further understanding of the subject, this study closely examines the specific biological effects proteinaceous particles may exert on dendritic cells (DCs) as the most efficient antigen-presenting cell population crucial for the initiation of the adaptive immune response. Two different model IgG antibodies were subjected to three different types of exaggerated physical stress to generate subvisible particles in far greater concentrations than the ones typical for the currently marketed biotherapeutical antibodies. The aggregated samples were used in in vitro biological assays in order to interrogate the early DC-driven events that initiate CD4 T-cell dependent humoral adaptive immune responses – peptide presentation capacity and co-stimulatory activity of DCs. Most importantly, antigen presentation was addressed with a unique approach called MHC-associated peptide proteomics (MAPPs), which allows for identifying the sequences of HLA-DR associated peptides directly from human dendritic cells [1]. The experiments demonstrated that highly aggregated solutions of two model mAbs generated under controlled conditions can induce activation of human monocyte-derived DCs as indicated by upregulation of typical maturation markers including co-stimulatory molecules necessary for CD4 T-cell activation. Additional data suggest that highly aggregated proteins could induce in vitro T-cell responses. Intriguingly, strong aggregation-mediated changes in the pattern and quantity of antigen-derived HLA-DR associated peptides presented on DCs were observed, indicating a change in protein processing and presentation. Increasing the amounts of subvisible proteinaceous particles correlated very well with the pronounced increase in the peptide number and clusters presented in the context of class II HLA-DR molecules, suggesting a major involvement of a mass-action mechanism of altering the presentation

Correlation of HLA-DR associated peptides and peptide clusters measured by MAPPs to the amount of protein present in subvisible particles.

<p>Linear regression analyses of the increase of the HLA-DR associated peptides and clusters as functions of the calculated amount of protein present in the subvisible particles. Left up: HLA-DR associated peptides of mAb1 vs protein amount in subvisible particles (r² = 0.994), left down: HLA-DR associated peptide clusters of mAb1 vs protein amount in subvisible particles (r² = 0.993), right up: HLA-DR associated peptides of mAb2 vs protein amount in subvisible particles (r² = 0.86), right down: HLA-DR associated peptide clusters of mAb2 vs protein amount in subvisible particles (r² = 0.943). HS: aggregates generated by heat and shake stress; FT: aggregates generated by freeze and thaw stress, S: aggregates generated by shear stress mAb1: monoclonal antibody 1, mAb2: monoclonal antibody 2, 1: stress level 1, 2: stress level 2. For further details, please, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086322#s4" target="_blank">Materials and Methods</a>.</p

MAPPs heat map of identified HLA-DR associated peptides in the HS study.

<p>Heat map visualization of mAb-derived HLA-DR associated peptides for both model antibodies in the HS study. Each sequence position is colored according to the presence and number of different mAb-derived peptides identified. In black colored sequence regions, no peptides were identified, in colored regions, peptides were identified, with the color coding for the number of different peptides identified per position. HS: aggregates generated by heat and shake stress; mAb1: monoclonal antibody 1, mAb2: monoclonal antibody 2, un: unstressed, sl1: stress level 1, sl2: stress level 2.</p

Physicochemical characterization of stressed mAb materials.

<p>Representative MFI screenshots after freeze/thaw (FT) stress of mAb1 (A) unstressed, un; (B) stress level 1, sl1; (C) stress level 2, sl2 and mAb2 un, (E) sl1 and (F) sl2. (G) Particle Size distribution obtained by MFI of mAb1 (left) and mAb2 (right). For visualization the size binning 2–2.5, 2.5–5, 5–10 10–25, 25–50 and 50–400 µm was used. Representative images of individual particles formed by (H) heat/shake, HS; (I) freeze/thaw, FT and (J) shear stress, S. Polydispersity in % (PD%) revealed by DLS for (K) mAb1 and (L) mAb2.</p

Induction of DC maturation by stressed mAb materials.

<p>(A) Percentage of responding donors determined as an at least 1.5-fold upregulation of the response index above unstressed mAb of the maturation markers CD83, CD80 and CD86. (B) Scatter plots of the response indices of individual donors for the measured maturation markers. The dotted line indicates the reference to unstressed mAb at 1.0. The horizontal line represents the average of the individual response indices. HS: aggregates generated by heat and shake stress, FT: aggregates generated by freeze and thaw stress, S: aggregates generated by shear stress, mAb1: monoclonal antibody 1, mAb2: monoclonal antibody 2, RI: Response index, sl1: stress level 1, sl2: stress level 2.</p