113 research outputs found

    Operational Semantics of Process Monitors

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    CSPe is a specification language for runtime monitors that can directly express concurrency in a bottom-up manner that composes the system from simpler, interacting components. It includes constructs to explicitly flag failures to the monitor, which unlike deadlocks and livelocks in conventional process algebras, propagate globally and aborts the whole system's execution. Although CSPe has a trace semantics along with an implementation demonstrating acceptable performance, it lacks an operational semantics. An operational semantics is not only more accessible than trace semantics but also indispensable for ensuring the correctness of the implementation. Furthermore, a process algebra like CSPe admits multiple denotational semantics appropriate for different purposes, and an operational semantics is the basis for justifying such semantics' integrity and relevance. In this paper, we develop an SOS-style operational semantics for CSPe, which properly accounts for explicit failures and will serve as a basis for further study of its properties, its optimization, and its use in runtime verification

    Reduced expression of monocyte CD200R is associated with enhanced proinflammatory cytokine production in sarcoidosis

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    In sarcoidosis, the proinflammatory cytokines interferon gamma, tumour necrosis factor and interleukin-6 are released by monocyte-derived macrophages and lymphocytes in the lungs and other affected tissues. Regulatory receptors expressed on monocytes and macrophages act to suppress cytokine production, and reduced expression of regulatory receptors may thus promote tissue inflammation. The aim of this study was to characterise the role of regulatory receptors on blood monocytes in patients with sarcoidosis. Cytokine release in response to stimulation of whole blood was measured in healthy controls and Caucasian non-smoking patients with sarcoidosis who were not taking disease modifying therapy. Expression of the regulatory molecules IL-10R, SIRP-α/β, CD47, CD200R, and CD200L was measured by flow cytometry, and functional activity was assessed using blocking antibodies. Stimulated whole blood and monocytes from patients with sarcoidosis produced more TNF and IL-6 compared with healthy controls. 52.9% of sarcoidosis patients had monocytes characterised by low expression of CD200R, compared with 11.7% of controls (p < 0.0001). Patients with low monocyte CD200R expression produced higher levels of proinflammatory cytokines. In functional studies, blocking the CD200 axis increased production of TNF and IL-6. Reduced expression of CD200R on monocytes may be a mechanism contributing to monocyte and macrophage hyper-activation in sarcoidosis

    Inactivation of [Fe-S] Metalloproteins Mediates Nitric Oxide-Dependent Killing of Burkholderia mallei

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    BACKGROUND: Much remains to be known about the mechanisms by which O(2)-dependent host defenses mediate broad antimicrobial activity. METHODOLOGY/PRINCIPAL FINDINGS: We show herein that reactive nitrogen species (RNS) generated by inducible nitric oxide (NO) synthase (iNOS) account for the anti-Burkholderia mallei activity of IFNgamma-primed macrophages. Inducible NOS-mediated intracellular killing may represent direct bactericidal activity, because B. mallei showed an exquisite sensitivity to NO generated chemically. Exposure of B. mallei to sublethal concentrations of NO upregulated transcription of [Fe-S] cluster repair genes, while damaging the enzymatic activity of the [Fe-S] protein aconitase. To test whether [Fe-S] clusters are critical targets for RNS-dependent killing of B. mallei, a mutation was constructed in the NO-induced, [Fe-S] cluster repair regulator iscR. Not only was the iscR mutant hypersusceptible to iNOS-mediated killing, but its aconitase pool was readily oxidized by NO donors as compared to wild-type controls. Although killed by authentic H(2)O(2), which also oxidizes [Fe-S] clusters, B. mallei appear to be resilient to NADPH oxidase-mediated cytotoxicity. The poor respiratory burst elicited by this bacterium likely explains why the NADPH oxidase is nonessential to the killing of B. mallei while it is still confined within phagosomes. CONCLUSIONS/SIGNIFICANCE: Collectively, these findings have revealed a disparate role for NADPH oxidase and iNOS in the innate macrophage response against the strict aerobe B. mallei. To the best of our knowledge, this is the first instance in which disruption of [Fe-S] clusters is demonstrated as cause of the bactericidal activity of NO congeners

    Access to Early Generation Seed: Obstacles for Delivery of Climate-Smart Varieties

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    Changing climates in eastern and southern Africa will require farmers to adjust which crop varieties they grow in order to adapt to changing patterns of weather, pests and diseases. Delivering more suitable, climate-smart crop varieties requires well-functioning seed systems in which actors work in harmony across the supply chain. Although a great deal of previous development funding has been used to breed new varieties and to encourage farmers to adopt them, the availability of early-generation seed (EGS) continues to be limited by bottlenecks in the supply chain. These problems are particularly significant for non-hybrid varieties and less-commercialized food crops developed by public-sector institutions. This study uses two contrasting case studies from Kenya to illustrate the importance of making improved bean seed varieties available to farmers. The first case study documents a successful instance of EGS transfer, whereas the second highlights the types of barriers that can prevent successful variety adoption. Improved coordination among system actors is necessary to reduce the barriers surrounding EGS provision and production, and thereby strengthen climate-adaptive and adaptable seed systems

    AMPD1 gene mutations are associated with obesity and diabetes in Polish patients with cardiovascular diseases

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    Previous studies showed an association of the common functional polymorphism (C34T, Gln12Stop) in the adenosine monophosphate deaminase-1 (AMPD1) gene with survival in heart failure (HF) and/or coronary artery disease (CAD). The aim of the study was to search for other mutations in selected regions of the AMPD1 gene in Polish CAD and HF patients, and to analyze their associations with obesity and diabetes. Exons 2, 3, 5, and 7 of AMPD1 were scanned for mutations in 97 patients with CAD without HF (CAD+ HF−), 104 patients with HF (HF+), and 200 newborns from North-Western Poland using denaturing high-performance liquid chromatography (DHPLC), polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), and direct sequencing. Frequencies of AMPD1 C34T mutation, as well as novel A99G, G512A, IVS4-6delT, and C784T sequence alterations, were similar in the three groups, but 860T mutated allele was less frequent in the combined CAD+ HF− and HF+ groups than in the controls (1.7% vs. 4.3%, p = 0.040). Heterozygous 34CT genotype was associated with lower (odds ratio [OR] = 0.32, 95% confidence interval [CI] = 0.13–0.81) and 860AT with higher (OR = 13.7, 95%CI = 1.6–118) prevalence of diabetes or hyperglycemia in relation to wild-type homozygotes. Abdominal obesity was more frequent in 860AT patients than in wild-type homozygotes and 34CT heterozygotes (86% vs. 40% vs. 29%, p < 0.05). Nine genes containing polymorphisms linked with AMPD1 C34T mutation were found in the HapMap database. AMPD1 C34T nonsense mutation is associated with reduced prevalence of diabetes and obesity in patients with CAD or HF, but A860T substitution seems to exert opposite metabolic effects and should always be accounted for in the studies of the AMPD1 genotype

    Rewriting DNA Methylation Signatures at Will:The Curable Genome Within Reach?

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    DNA methyltransferases are important enzymes in a broad range of organisms. Dysfunction of DNA methyltransferases in humans leads to many severe diseases, including cancer. This book focuses on the biochemical properties of these enzymes, describing their structures and mechanisms in bacteria, humans and other species, including plants, and also explains the biological processes of reading of DNA methylation and DNA demethylation. It covers many emerging aspects of the biological roles of DNA methylation functioning as an essential epigenetic mark and describes the role of DNA methylation in diseases. Moreover, the book explains modern technologies, like targeted rewriting of DNA methylation by designed DNA methyltransferases, as well as technological applications of DNA methyltransferases in DNA labelling. Finally, the book summarizes recent methods for the analysis of DNA methylation in human DNA. Overall, this book represents a comprehensive state-of-the-art- work and is a must-have for advanced researchers in the field of DNA methylation and epigenetics

    Cardiopulmonary assessment of patients with systemic sclerosis for hematopoietic stem cell transplantation: recommendations from the European Society for Blood and Marrow Transplantation Autoimmune Diseases Working Party and collaborating partners.

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    Systemic sclerosis (SSc) is a rare disabling autoimmune disease with a similar mortality to many cancers. Two randomized controlled trials of autologous hematopoietic stem cell transplantation (AHSCT) for SSc have shown significant improvement in organ function, quality of life and long-term survival compared to standard therapy. However, transplant-related mortality (TRM) ranged from 3-10% in patients undergoing HSCT. In SSc, the main cause of non-transplant and TRM is cardiac related. We therefore updated the previously published guidelines for cardiac evaluation, which should be performed in dedicated centers with expertize in HSCT for SSc. The current recommendations are based on pre-transplant cardiopulmonary evaluations combining pulmonary function tests, echocardiography, cardiac magnetic resonance imaging and invasive hemodynamic testing, initiated at Northwestern University (Chicago) and subsequently discussed and endorsed within the EBMT ADWP in 2016

    The effects of nitric oxide on the immune system during Trypanosoma cruzi infection

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