27 research outputs found

    Antarctic climate, Southern Ocean circulation patterns, and deep water formation during the Eocene

    Get PDF
    We assess early-to-middle Eocene seawater neodymium (Nd) isotope records from seven Southern Ocean deep-sea drill sites to evaluate the role of Southern Ocean circulation in long-term Cenozoic climate change. Our study sites are strategically located on either side of the Tasman Gateway and are positioned at a range of shallow (Nd(t) = −9.3 ± 1.5). IODP Site U1356 off the coast of Adélie Land, a locus of modern-day Antarctic Bottom Water production, is identified as a site of persistent deep water formation from the early Eocene to the Oligocene. East of the Tasman Gateway an additional local source of intermediate/deep water formation is inferred at ODP Site 277 in the SW Pacific Ocean (εNd(t) = −8.7 ± 1.5). Antarctic-proximal shelf sites (ODP Site 1171 and Site U1356) reveal a pronounced erosional event between 49 and 48 Ma, manifested by ~2 εNd unit negative excursions in seawater chemistry toward the composition of bulk sediments at these sites. This erosional event coincides with the termination of peak global warmth following the Early Eocene Climatic Optimum and is associated with documented cooling across the study region and increased export of Antarctic deep waters, highlighting the complexity and importance of Southern Ocean circulation in the greenhouse climate of the Eocene

    Cost-Based Filtering Techniques for Stochastic Inventory Control Under Service Level Constraints

    Get PDF
    This paper(1) considers a single product and a single stocking location production/inventory control problem given a non-stationary stochastic demand. Under a widely-used control policy for this type of inventory system, the objective is to find the optimal number of replenishments, their timings and their respective order-up-to-levels that meet customer demands to a required service level. We extend a known CP approach for this problem using three cost-based filtering methods. Our approach can solve to optimality instances of realistic size much more efficiently than previous approaches, often with no search effort at all

    Prevalence and Mechanisms of Mucus Accumulation in COVID-19 Lung Disease

    Get PDF
    Rationale: The incidence and sites of mucus accumulation, and molecular regulation of mucin gene expression, in COVID-19 lung disease have not been reported. Objectives: Characterize incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. Methods: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by AB-PAS and immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. SARS-CoV-2-infected human bronchial epithelial (HBE) cultures were utilized to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. Measurements and Main Results: MUC5B and variably MUC5AC RNA levels were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the sub-acute/chronic disease phase following SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of COVID-19 subjects in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days post inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days post inoculation. SARS-CoV-2 infection of HBE cultures induced expression of EGFR ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways, or dexamethasone administration, reduced SARS-CoV-2-induced mucin expression. Conclusions: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation post SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org.libproxy.lib.unc.edu/licenses/by-nc-nd/4.0/)

    Analysis of the common genetic component of large-vessel vasculitides through a meta- Immunochip strategy

    Get PDF
    Giant cell arteritis (GCA) and Takayasu's arteritis (TAK) are major forms of large-vessel vasculitis (LVV) that share clinical features. To evaluate their genetic similarities, we analysed Immunochip genotyping data from 1,434 LVV patients and 3,814 unaffected controls. Genetic pleiotropy was also estimated. The HLA region harboured the main disease-specific associations. GCA was mostly associated with class II genes (HLA-DRB1/HLA-DQA1) whereas TAK was mostly associated with class I genes (HLA-B/MICA). Both the statistical significance and effect size of the HLA signals were considerably reduced in the cross-disease meta-analysis in comparison with the analysis of GCA and TAK separately. Consequently, no significant genetic correlation between these two diseases was observed when HLA variants were tested. Outside the HLA region, only one polymorphism located nearby the IL12B gene surpassed the study-wide significance threshold in the meta-analysis of the discovery datasets (rs755374, P?=?7.54E-07; ORGCA?=?1.19, ORTAK?=?1.50). This marker was confirmed as novel GCA risk factor using four additional cohorts (PGCA?=?5.52E-04, ORGCA?=?1.16). Taken together, our results provide evidence of strong genetic differences between GCA and TAK in the HLA. Outside this region, common susceptibility factors were suggested, especially within the IL12B locus

    Nonpalpable breast cancer: Percutaneous diagnosis with 11- and 8-gauge stereotactic vacuum-assisted biopsy devices

    No full text
    PURPOSE: To compare the accuracy of diagnosis of invasive breast cancer with 11- and 8-gauge stereotactic vacuum-assisted biopsy (SVAB) devices and to correlate lesion diameter and accuracy of breast cancer diagnosis at SVAB. MATERIALS AND METHODS; During a 22-month period, 489 SVAB procedures were performed with an 11-gauge probe and 305 with an 8-gauge probe. SVAB and surgical pathologic results of 104 breast carcinomas were reviewed and correlated with lesion size, number of specimens obtained, and type of SVAB probe used. RESULTS: Four of 38 ductal carcinoma in situ (DCIS) lesions diagnosed with 11-gauge SVAB demonstrated invasion at surgery, whereas one of 23 DCIS lesions diagnosed with 8-gauge SVAB demonstrated invasion at surgery (P = .6). A mean of 12 specimens per lesion were obtained in each group. In lesions 30 mm or larger, the underestimation rate for DCIS was 43% (three of seven) with 11-gauge SVAB and 17% (one of six) with 8-gauge SVAB (P = .6). Overall, the rate of underestimation for DCIS was significantly higher in lesions 30 mm or larger (four of 13) than in smaller lesions (one of 48, P = .006). CONCLUSION: This study demonstrated no difference in breast cancer diagnosis with the 8- and 11 -gauge SVAB systems, but the accuracy of breast cancer diagnosis was greater in lesions smaller than 30 mm than in larger lesions

    A phase 1/2 trial of arginine butyrate and ganciclovir in patients with Epstein-Barr virus–associated lymphoid malignancies

    No full text
    Malignancies associated with latent Epstein-Barr virus (EBV) are resistant to nucleoside-type antiviral agents because the viral enzyme target of these antiviral drugs, thymidine kinase (TK), is not expressed. Short-chain fatty acids, such as butyrate, induce EBV-TK expression in latently infected B cells. As butyrate has been shown to sensitize EBV(+) lymphoma cells in vitro to apoptosis induced by ganciclovir, arginine butyrate in combination with ganciclovir was administered in 15 patients with refractory EBV(+) lymphoid malignancies to evaluate the drug combination for toxicity, pharmacokinetics, and clinical responses. Ganciclovir was administered twice daily at standard doses, and arginine butyrate was administered by continuous infusion in an intrapatient dose escalation, from 500 mg/(kg/day) escalating to 2000 mg/(kg/day), as tolerated, for a 21-day cycle. The MTD for arginine butyrate in combination with ganciclovir was established as 1000 mg/(kg/day). Ten of 15 patients showed significant antitumor responses, with 4 CRs and 6 PRs within one treatment cycle. Complications from rapid tumor lysis occurred in 3 patients. Reversible somnolence or stupor occurred in 3 patients at arginine butyrate doses of greater than 1000 mg/(kg/day). The combination of arginine butyrate and ganciclovir was reasonably well-tolerated and appears to have significant biologic activity in vivo in EBV(+) lymphoid malignancies which are refractory to other regimens
    corecore