1,797 research outputs found

    Solid weak BCC-algebras

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    We characterize weak BCC-algebras in which the identity (xy)z=(xz)y(xy)z=(xz)y is satisfied only in the case when elements x,yx,y belong to the same branch

    Scotland as an optimal currency area

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    The June 2016 UK referendum on continued EU membership where the people of Scotland voted to remain, while the rest of the United Kingdom voted to leave, once again makes the issue of whether Scotland is an optimal currency area very topical. England voted strongly to leave Europe while Scotland backed remain by 62% to 38%. The Scottish government published its draft bill on a second independence referendum in October 2016. The move does not mean another referendum will definitely be held, but this does raise the possibility that Scotland might choose independence and staying in the EU without the rest of the United Kingdom. If Scotland charts a course of independence from the rest of the United Kingdom, then they would likely either issue their own currency or join or form another currency area. In this paper, we test the microeconomic foundations of a common currency area for Scotland, United Kingdom, and the rest of the United Kingdom without Scotland. We find that the United Kingdom, Scotland, and the United Kingdom without Scotland all meet the microeconomic criteria for a common currency area. In contrast, banking data suggest that lending in Scotland is different from lending in the rest of the United Kingdom, adding some doubt to the issue of whether or not Scotland is a common currency area with the United Kingdom.</p

    Frequency domain analysis for detecting pipeline leaks

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    The original publication can be found at http://scitation.aip.org/hyoThis paper introduces leak detection methods that involve the injection of a fluid transient into the pipeline, with the resultant transient trace analyzed in the frequency domain. Two methods of leak detection using the frequency response of the pipeline are proposed. The inverse resonance method involves matching the modeled frequency responses to those observed to determine the leak parameters. The peak-sequencing method determines the region in which the leak is located by comparing the relative sizes between peaks in the frequency response diagram. It was found that a unique pattern was induced on the peaks of the frequency response for each specific location of the leak within the pipeline. The leak location can be determined by matching the observed pattern to patterns generated numerically within a lookup table. The procedure for extracting the linear frequency response diagram, including the optimum measurement position, the effect of unsteady friction, and the way in which the technique can be extended into pipeline networks, are also discussed within the paper.Pedro J. Lee, John P. Vítkovský, Martin F. Lambert, Angus R. Simpson and James A. Ligget

    Polymer Light‐Emitting Transistors With Charge‐Carrier Mobilities Exceeding 1 cm2 V−1 s−1

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    The vast majority of conjugated polymer-based light emitting field-effect transistors (LEFETs) are characterized by low charge carrier mobilities typically in the range 10-5 to 10-3 cm2 V-1 s-1 range. Fast carrier transport is a highly desirable characteristic for high frequency LEFET operation and, potentially, for use in electrically-pumped lasers. Unfortunately, high mobility organic semiconductors are often characterised by strong intermolecular π-π interactions that reduce luminescence. Development of new materials and/or device concepts that overcome this hurdle are therefore required. We report single organic semiconductor layer, light-emitting transistors that combine the highest hole mobilities reported to date for any polymer-based LEFET, with encouraging light emission characteristics. We achieve this in a single polymer layer LEFET, which was further enhanced through the use of a small-molecule/conjugated polymer blend system that possesses a film microstructure which supports enhanced charge carrier mobility (3.2 cm2 V-1 s-1) and promising light emission characteristics (1600 cd m-2) as compared to polymer-only based LEFETs. This simple approach represents an attractive strategy to further advance the performance of solution-processed LEFETs

    Seasonal correlation of aerosols with soil moisture, evapotranspiration, and vegetation over Pakistan using remote sensing

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    Aerosols have a severe impact on the Earth's climate, human health, and ecosystem. To understand the impacts of aerosols on climate, human health, and the ecosystem we must need to understand the variability of aerosols and their optical properties. Therefore, we used Aqua-MODIS retrieved aerosol optical depth (AOD) (550 nm) and Angstrom exponent (AE) (440/870) data to analyze the Spatio-temporal seasonal variability of aerosols and their relationship with different meteorological parameters over Pakistan from 2002 to 2021. High (>0.5) AOD values were observed during the summer season and low (1) in the northern regions of Pakistan indicating the dominance of fine mode particles during the winter season. Moreover, AOD showed a positive correlation with Relative Humidity (RH), Evapotranspiration, Wind speed (WS), and Temperature. On the other hand, it showed a negative correlation with Soil moisture (SM), Normalized difference vegetation index (NDVI), and precipitation over Pakistan. Therefore, considering the outcomes of this study will help policymakers to understand the spatiotemporal variability of aerosols and their seasonal correlation with different meteorological parameters. © 2023 The AuthorsNational Aeronautics and Space Administration, NASAWe acknowledged NASA for providing us with MODIS and AIRS datasets

    Innate Immune Molecule NLRC5 Protects Mice From Helicobacter-induced Formation of Gastric Lymphoid Tissue

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    BACKGROUND &amp; AIMS: Helicobacter pylori induces strong inflammatory responses that are directed at clearing the infection, but if not controlled, these responses can be harmful to the host. We investigated the immune-regulatory effects of the innate immune molecule, nucleotide-binding oligomerization domain-like receptors (NLR) family CARD domaincontaining 5 (NLRC5), in patients and mice with Helicobacter infection. METHODS: We obtained gastric biopsies from 30 patients in Australia. We performed studies with mice that lack NLRC5 in the myeloid linage (Nlrc5(memptysetKO)) and mice without Nlrc5 gene disruption (controls). Some mice were gavaged with H pylori SS1 or Helicobacter felis; 3 months later, stomachs, spleens, and sera were collected, along with macrophages derived from bone marrow. Human and mouse gastric tissues and mouse macrophages were analyzed by histology, immunohistochemistry, immunoblots, and quantitative polymerase chain reaction. THP-1 cells (human macrophages, controls) and NLRC5(-/-) THP-1 cells (generated by CRISPR-Cas9 gene editing) were incubated with Helicobacter and gene expression and production of cytokines were analyzed. RESULTS: Levels of NLRC5 messenger RNA were significantly increased in gastric tissues from patients with H pylori infection, compared with patients without infection ( P &lt;.01), and correlated with gastritis severity (P&lt;.05). H pylori bacteria induced significantly higher levels of chemokine and cytokine production by NLRC5(-/-) THP-1 macrophages than by control THP- 1 cells (P&lt;.05). After 3 months of infection with H felis, Nlrc5(memptyset-KO) mice developed gastric hyperplasia (P&lt;.0001), splenomegaly (P &lt;.0001), and increased serum antibody titers (P&lt;.01), whereas control mice did not. Nlrc5(memptyset-KO) mice with chronic H felis infection had increased numbers of gastric B-cell follicles expressing CD19 (P&lt;.0001); these follicles had features of mucosa-associated lymphoid tissue lymphoma. We identified B-cell-activating factor as a protein that promoted B-cell hyperproliferation in Nlrc5(memptyset-KO) mice. CONCLUSIONS: NLRC5 is a negative regulator of gastric inflammation and mucosal lymphoid formation in response to Helicobacter infection. Aberrant NLRC5 signaling in macrophages can promote B-cell lymphomagenesis during chronic Helicobacter infection

    Comparative Toxicity of Fumigants and a Phosphine Synergist Using a Novel Containment Chamber for the Safe Generation of Concentrated Phosphine Gas

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    BACKGROUND: With the phasing out of ozone-depleting substances in accordance with the United Nations Montreal Protocol, phosphine remains as the only economically viable fumigant for widespread use. However the development of high-level resistance in several pest insects threatens the future usage of phosphine; yet research into phosphine resistance mechanisms has been limited due to the potential for human poisoning in enclosed laboratory environments. PRINCIPAL FINDINGS: Here we describe a custom-designed chamber for safely containing phosphine gas generated from aluminium phosphide tablets. In an improvement on previous generation systems, this chamber can be completely sealed to control the escape of phosphine. The device has been utilised in a screening program with C. elegans that has identified a phosphine synergist, and quantified the efficacy of a new fumigant against that of phosphine. The phosphine-induced mortality at 20°C has been determined with an LC(50) of 732 ppm. This result was contrasted with the efficacy of a potential new botanical pesticide dimethyl disulphide, which for a 24 hour exposure at 20°C is 600 times more potent than phosphine (LC(50) 1.24 ppm). We also found that co-administration of the glutathione depletor diethyl maleate (DEM) with a sublethal dose of phosphine (70 ppm, <LC(5)), results in a doubling of mortality in C. elegans relative to DEM alone. CONCLUSIONS: The prohibitive danger associated with the generation, containment, and use of phosphine in a laboratory environment has now been substantially reduced by the implementation of our novel gas generation chamber. We have also identified a novel phosphine synergist, the glutathione depletor DEM, suggesting an effective pathway to be targeted in future synergist research; as well as quantifying the efficacy of a potential alternative to phosphine, dimethyl disulphide
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