34 research outputs found

    The Integrability of Pauli System in Lorentz Violating Background

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    We systematically analyze the integrability of a Pauli system in Lorentz violating background at the non-relativistic level both in two- and three-dimensions. We consider the non-relativistic limit of the Dirac equation from the QED sector of the so-called Standard Model Extension by keeping only two types of background couplings, the vector a_mu and the axial vector b_mu. We show that the spin-orbit interaction comes as a higher order correction in the non-relativistic limit of the Dirac equation. Such an interaction allows the inclusion of spin degree non-trivially, and if Lorentz violating terms are allowed, they might be comparable under special circumstances. By including all possible first-order derivative terms and considering the cases a\ne 0, b\ne 0, and b_0\ne 0 one at a time, we determine the possible forms of constants of motion operator, and discuss the existence or continuity of integrability due to Lorentz violating background.Comment: 19 page

    Bottom trawl fishing footprints on the world’s continental shelves

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    Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from 50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing

    Triple therapy in the eradication of Helicobacter pylori in patients with duodenal ulcer disease: Results of a multicentre study in South-East Asia

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    10.1046/j.1365-2036.2000.00691.xAlimentary Pharmacology and Therapeutics142225-231APTH

    Autoimmune hepatitis in Singapore: A rare syndrome affecting middle-aged women

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    10.1046/j.1440-1746.2001.02646.xJournal of Gastroenterology and Hepatology16121384-1389JGHE

    Endoscopic ultrasound-guided fine needle aspiration in the evaluation of suspected lung cancer

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    SummaryBackground and aimThe role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the diagnosis and staging of lung cancer is still not fully explored. This prospective study aimed to define the effectiveness of EUS-FNA as an adjunct to computer tomography (CT) and bronchoscopy in the evaluation of suspected lung cancer in routine clinical practice.MethodsOver a period of 20 weeks, the data of 16 consecutive patients suspected of lung cancer on account of respiratory symptoms, and/or the findings of either a mass or mediastinal lymph nodes on helical CT, who were referred for evaluation by EUS, were prospectively collected. Fourteen of these patients underwent sequential bronchoscopy followed by EUS-FNA in the same setting.ResultsBronchoscopy was performed in 15 patients, while EUS was performed in all 16 patients. Bronchoscopy diagnosed 9 cases of non-small-cell lung cancer (NSCLC) but was falsely negative in 3 cases of malignancies, which were all established by EUS-FNA of mediastinal lymph nodes (2 cases of NSCLC and 1 case of esophageal squamous cell cancer). EUS-FNA also diagnosed advanced NSCLC in another patient who did not undergo bronchoscopy, such that eventually 13 patients were diagnosed to have malignancies. Distant metastases were diagnosed by EUS-FNA in 4 cases of NSCLC (2 cases of left adrenal gland and 2 cases of pancreatic metastases). Two patients were diagnosed to have sarcoidosis and 1 patient was diagnosed to have pneumoconiosis eventually.ConclusionsEUS-FNA is useful as an adjunct to CT and bronchoscopy in the evaluation of suspected lung cancer

    Gastro-oesophageal reflux disease in Asia

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    Gastro-oesophageal reflux disease (GORD) occurs more frequently in Europe and North America than in Asia but its prevalence is now increasing in many Asian countries. Many reasons have been given for the lower prevalence of GORD in Asia. Low dietary fat and genetically determined factors, such as body mass index and maximal acid output, may be important. Other dietary factors appear to be less relevant. Increased intake of carbonated drinks or aggravating medicines may influence the increasing rates of GORD in some Asian countries but no strong evidence links other factors, such as the age of the population, smoking or alcohol consumption, to GORD. The management of GORD in Asia is similar to that in Europe and North America but the lower incidence of severe oesophagitis in Asia may alter the approach slightly. Also, because Asians tend to develop stomach cancer at an earlier age, endoscopy is used routinely at an earlier stage of investigation. Gastro-oesophageal reflux disease is essentially a motility disorder, so short-term management of the disease can usually be achieved using prokinetic agents (or histamine (H2)-receptor antagonists). More severe and recurrent GORD may require proton pump inhibitors (PPI) or a combination of prokinetic agents and PPI. The choice of long-term treatment may be influenced by the relative costs of prokinetic agents and PPI

    Renal transplantation and hepatitis B viral (HBV) replication

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    K.M. Fock, C.J. Burrell, T. Mathew, G. Russ, A. Disney and M.J. Lawso
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