528 research outputs found

    Disrupted Resolution Mechanisms Favor Altered Phagocyte Responses in Covid-19.

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    Rationale: Resolution mechanisms are central in both the maintenance of homeostasis and the return to catabasis following tissue injury and/or infections. Amongst the pro-resolving mediators, the essential fatty acid-derived specialized pro-resolving lipid mediators (SPM) govern immune responses to limit disease severity. Notably, little is known about the relationship between the expression and activity of SPM pathways, circulating phagocyte function and disease severity in patients infected with novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leading to coronavirus disease 2019 (COVID-19). Objective: Herein, we investigated the link between circulating SPM concentrations and phagocyte activation status and function in COVID-19 patients (n=39) compared to healthy (n=12) and post-COVID-19 (n=8) volunteers. Methods and Results: Lipid mediator profiling demonstrated that plasma SPM concentrations were upregulated in patients with mild COVID-19 and are downregulated in those with severe disease. SPM concentrations were correlated with both circulating phagocyte activation status and function. Perturbations in plasma SPM concentrations and phagocyte activation were retained after the resolution of COVID-19 clinical symptoms. Treatment of patients with dexamethasone upregulated both the expression of SPM biosynthetic enzymes in circulating phagocytes and plasma concentration of these mediators. Furthermore, incubation of phagocytes from COVID-19 patients with SPM rectified their phenotype and function. This included a downregulation in the expression of activation markers, a decrease in the Tissue Factor and inflammatory cytokine expression, and an upregulation of bacterial phagocytosis. Conclusions: The present findings suggest that downregulation of systemic SPM concentrations is linked with both increased disease severity and dysregulated phagocyte function. They also identify the upregulation of these mediators by dexamethasone as a potential mechanism in host protective activities elicited by this drug in COVID-19 patients. Taken together, our findings elucidate a role for altered resolution mechanisms in the disruption of phagocyte responses and the propagation of systemic inflammation in COVID-19

    Infrared Spectroscopy of Symbiotic Stars. IV. V2116 Ophiuchi/GX 1+4, The Neutron Star Symbiotic

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    We have computed, based on 17 infrared radial velocities, the first set of orbital elements for the M giant in the symbiotic binary V2116 Ophiuchi. The giant's companion is a neutron star, the bright X-ray source GX 1+4. We find an orbital period of 1161 days by far the longest of any known X-ray binary. The orbit has a modest eccentricity of 0.10 with an orbital circularization time of less than 10^6 years. The large mass function of the orbit significantly restricts the mass of the M giant. Adopting a neutron-star mass of 1.35M(Sun), the maximum mass of the M giant is 1.22M(Sun), making it the less massive star. Derived abundances indicate a slightly subsolar metallicity. Carbon and nitrogen are in the expected ratio resulting from the red-giant first dredge-up phase. The lack of O-17 suggests that the M-giant has a mass less than 1.3M(Sun), consistent with our maximum mass. The red giant radius is 103R(Sun), much smaller than the estimated Roche lobe radius. Thus, the mass loss of the red giant is via a stellar wind. Although the M giant companion to the neutron star has a mass similar to the late-type star in low-mass X-ray binaries, its near-solar abundances and apparent runaway velocity are not fully consistent with the properties of this class of stars.Comment: In press to The Astrophysical Journal (10 April 2006 issue). 23 page

    The Erotic and the Vulgar: Visual Culture and Organized Labor's Critique of U.S. Hegemony in Occupied Japan

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    This essay engages the colonial legacy of postwar Japan by arguing that the political cartoons produced as part of the postwar Japanese labor movement’s critique of U.S. cultural hegemony illustrate how gendered discourses underpinned, and sometimes undermined, the ideologies formally represented by visual artists and the organizations that funded them. A significant component of organized labor’s propaganda rested on a corpus of visual media that depicted women as icons of Japanese national culture. Japan’s most militant labor unions were propagating anti-imperialist discourses that invoked an engendered/endangered nation that accentuated the importance of union roles for men by subordinating, then eliminating, union roles for women

    Detailed Investigation of the Role of Common and Low-Frequency WFS1 Variants in Type 2 Diabetes Risk

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    OBJECTIVE: Wolfram syndrome 1 (WFS1) single nucleotide polymorphisms (SNPs) are associated with risk of type 2 diabetes. In this study we aimed to refine this association and investigate the role of low-frequency WFS1 variants in type 2 diabetes risk. RESEARCH DESIGN AND METHODS: For fine-mapping, we sequenced WFS1 exons, splice junctions, and conserved noncoding sequences in samples from 24 type 2 diabetic case and 68 control subjects, selected tagging SNPs, and genotyped these in 959 U.K. type 2 diabetic case and 1,386 control subjects. The same genomic regions were sequenced in samples from 1,235 type 2 diabetic case and 1,668 control subjects to compare the frequency of rarer variants between case and control subjects. RESULTS: Of 31 tagging SNPs, the strongest associated was the previously untested 3' untranslated region rs1046320 (P = 0.008); odds ratio 0.84 and P = 6.59 x 10(-7) on further replication in 3,753 case and 4,198 control subjects. High correlation between rs1046320 and the original strongest SNP (rs10010131) (r2 = 0.92) meant that we could not differentiate between their effects in our samples. There was no difference in the cumulative frequency of 82 rare (minor allele frequency [MAF] 100,000) or studies in ethnically diverse populations. Low frequency variants in WFS1 are unlikely to have a large impact on type 2 diabetes risk in white U.K. populations, highlighting the complexities of undertaking association studies with low-frequency variants identified by resequencing

    Observed microphysical changes in Arctic mixed-phase clouds when transitioning from sea ice to open ocean

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    In situ airborne observations of cloud microphysics, aerosol properties, and thermodynamic structure over the transition from sea ice to ocean are presented from the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) campaign. A case study from 23 March 2013 provides a unique view of the cloud microphysical changes over this transition under cold-air outbreak conditions. Cloud base lifted and cloud depth increased over the transition from sea ice to ocean. Mean droplet number concentrations, Ndrop, also increased from 110±36cm−3 over the sea ice to 145±54cm−3 over the marginal ice zone (MIZ). Downstream over the ocean, Ndrop decreased to 63±30cm−3. This reduction was attributed to enhanced collision-coalescence of droplets within the deep ocean cloud layer. The liquid water content increased almost four fold over the transition and this, in conjunction with the deeper cloud layer, allowed rimed snowflakes to develop and precipitate out of cloud base downstream over the ocean. The ice properties of the cloud remained approximately constant over the transition. Observed ice crystal number concentrations averaged approximately 0.5–1.5L−1, suggesting only primary ice nucleation was active; however, there was evidence of crystal fragmentation at cloud base over the ocean. Little variation in aerosol particle number concentrations was observed between the different surface conditions; however, some variability with altitude was observed, with notably greater concentrations measured at higher altitudes ( > 800m) over the sea ice. Near-surface boundary layer temperatures increased by 13°C from sea ice to ocean, with corresponding increases in surface heat fluxes and turbulent kinetic energy. These significant thermodynamic changes were concluded to be the primary driver of the microphysical evolution of the cloud. This study represents the first investigation, using in situ airborne observations, of cloud microphysical changes with changing sea ice cover and addresses the question of how the microphysics of Arctic stratiform clouds may change as the region warms and sea ice extent reduces
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