19 research outputs found

    EUREC <sup>4</sup>A

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    The science guiding the EUREC4A campaign and its measurements is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic –eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4Amarked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso-(200km) and larger (500km) scales, roughly 400h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced groundbased cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC4A explored –from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation–are presented along with an overview of EUREC4A’s outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement

    Role of Acid Sphingomyelinase in Shifting the Balance Between Proinflammatory and Reparative Bone Marrow Cells in Diabetic Retinopathy

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    The metabolic insults associated with diabetes lead to low-grade chronic inflammation, retinal endothelial cell damage, and inadequate vascular repair. This is partly due to the increased activation of bone marrow (BM)-derived proinflammatory monocytes infiltrating the retina, and the compromised function of BM-derived reparative circulating angiogenic cells (CACs), which home to sites of endothelial injury and foster vascular repair. We now propose that a metabolic link leading to activated monocytes and dysfunctional CACs in diabetes involves upregulation of a central enzyme of sphingolipid signaling, acid sphingomyelinase (ASM). Selective inhibition of ASM in the BM prevented diabetes-induced activation of BM-derived microglia-like cells and normalized proinflammatory cytokine levels in the retina. ASM upregulation in diabetic CACs caused accumulation of ceramide on their cell membrane, thereby reducing membrane fluidity and impairing CAC migration. Replacing sphingomyelin with ceramide in synthetic membrane vesicles caused a similar decrease in membrane fluidity. Inhibition of ASM in diabetic CACs improved membrane fluidity and homing of these cells to damaged retinal vessels. Collectively, these findings indicate that selective modulation of sphingolipid metabolism in BM-derived cell populations in diabetes normalizes the reparative/proinflammatory cell balance and can be explored as a novel therapeutic strategy for treating diabetic retinopathy

    26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

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    This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

    The evolution of warm rain in trade-wind cumulus during EUREC4A

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    In this paper measurements are presented of the observed properties of aerosols and microphysics of clouds associated with the characteristics of precipitation in convective clouds that formed off the east coast of Barbados during EUREC4A. Most data were gathered by the instrumented British Antarctic Survey Twin Otter aircraft supported by detailed in-situ aerosol measurements at the Ragged Point observatory on Barbados as well as HALO and PoldiRad radars, dropsonde and satellite data. The development of precipitation was studied in the three aerosol regimes previously reported, i.e. one low aerosol regime and two containing desert dust that had been advected across the Atlantic Ocean. The later dust event also contained evidence of biomass burning aerosol. Results showed that the maximum intensity of rain was similar for all the aerosol regimes. Clouds that developed in an environment with high aerosol loading tended to be deeper than those that developed in the clean environment. It was also found that the greatest intensities occurred in clouds that had aggregated, in agreement with previous work

    Isolation and characterization of pharmaceutical grade human pentraxins, serum amyloid P component and C‐reactive protein, for clinical use

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    AbstractThe human pentraxin proteins, serum amyloid P component (SAP) and C‐reactive protein (CRP) are important in routine clinical diagnosis, SAP for systemic amyloidosis and CRP for monitoring the non‐specific acute phase response. They are also targets for novel therapies currently in development but their roles in health and disease are controversial. Thus, both for clinical use and to rigorously elucidate their functions, structurally and functionally intact, pharmaceutical grade preparations of the natural, authentic proteins are required. We report here the production from normal human donor plasma and the characterization of the first such preparations. Importantly, we demonstrate that, contrary to reports using recombinant proteins and less well characterized preparations, neither CRP nor SAP stimulate the release by human peripheral blood mononuclear cells in vitro of any TNFα, IL‐6 or IL‐8, nor does SAP cause release of IL‐1β or IL‐10. Furthermore neither of our preparations was pro‐inflammatory in mice in vivo
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