3,024 research outputs found

    Continuous-Time Monte Carlo study of the pseudogap Bose-Fermi Kondo model

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    We study the pseudogap Bose-Fermi Anderson model with a continuous-time quantum Monte Carlo (CT-QMC) method. We discuss some delicate aspects of the transformation from this model to the Bose-Fermi Kondo model. We show that the CT-QMC method can be used at sufficiently low temperatures to access the quantum critical properties of these models.Comment: SCES 2010 Proceeding

    Antimicrobial resistance characteristics and fitness of Gram-negative fecal bacteria from volunteers treated with minocycline or amoxicillin.

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    A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year

    Uncertainty Estimates for Theoretical Atomic and Molecular Data

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    Sources of uncertainty are reviewed for calculated atomic and molecular data that are important for plasma modeling: atomic and molecular structure and cross sections for electron-atom, electron-molecule, and heavy particle collisions. We concentrate on model uncertainties due to approximations to the fundamental many-body quantum mechanical equations and we aim to provide guidelines to estimate uncertainties as a routine part of computations of data for structure and scattering.Comment: 65 pages, 18 Figures, 3 Tables. J. Phys. D: Appl. Phys. Final accepted versio

    3,3′-(2,2′-Bi-1H-imidazole-1,1′-di­yl)dipropanamide

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    In the title compound, C12H16N6O2, the two imidazole rings are coplanar as a center of inversion exists midway along the C—C bond joining the two rings. In the crystal, inter­molecular N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds link adjacent mol­ecules into a two-dimensional layer structure parallel to (001)

    Companion plants and straw mulch reduce cabbage stem flea beetle (Psylliodes chrysocephala) damage on oilseed rape

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    Plant diversification, especially sowing crops with the addition of companion plants has been demonstrated as a suitable practice to increase insect pest control in multiple cropping systems. Since the ban on use of neonicotinoid seed treatments in oilseed rape (OSR), the harvested area has reduced significantly in Europe, mainly because of the damage caused by cabbage stem flea beetle (Psylliodes chrysocephala). Several companion plants such as legumes and other species of Brassicaceae have been reported as potential companions for OSR but robust evaluation of their efficiency to reduce cabbage stem flea beetle damage in replicated trials is lacking. Four field trials were conducted in the UK and Germany to test the effect of different companion plants, or the addition of straw mulch, on cabbage stem flea beetle adult feeding and larval infestation in OSR. We found significant differences in the level of feeding damage between treatments in all experiments. Combinations of OSR with cereal companion plants or with straw mulch showed the strongest reduction in adult feeding damage. A protective effect of legumes was also observed in one trial. Differences in larval infestation were also observed between treatments but were not consistent and might be more related to the OSR plant biomass than to treatments. This study shows that companion planting can protect OSR crops from cabbage stem flea beetle adult feeding damage. We show for the first time that not only legumes, but also cereals and the application of straw mulch can have a strong protective effect on the crop

    The Formal Dynamism of Categories: Stops vs. Fricatives, Primitivity vs. Simplicity

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    Minimalist Phonology (MP; Pöchtrager 2006) constructs its theory based on the phonological epistemological principle (Kaye 2001) and exposes the arbitrary nature of standard Government Phonology (sGP) and strict-CV (sCV), particularly with reference to their confusion of melody and structure. For Pöchtrager, these are crucially different, concluding that place of articulation is melodic (expressed with elements), while manner of articulation is structural. In this model, the heads (xN and xO) can license and incorporate the length of the other into their own interpretation, that is xN influences xO projections as well as its own and vice versa. This dynamism is an aspect of the whole framework and this paper in particular will show that stops and fricatives evidence a plasticity of category and that, although fricatives are simpler in structure, stops are the more primitive of the two. This will be achieved phonologically through simply unifying the environment of application of the licensing forces within Pöchtrager's otherwise sound onset structure. In doing so, we automatically make several predictions about language acquisition and typology and show how lenition in Qiang (Sino-Tibetan) can be more elegantly explained

    Capecitabine in the treatment of metastatic renal cell carcinoma

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    To evaluate the therapeutic effects and systemic toxicities of a capecitabine-based home therapy regimen in patients with metastatic renal cell carcinoma, 30 patients were enrolled in a phase II clinical trial. Treatment consisted of oral capecitabine combined with subcutaneous recombinant human interferon-α 2a, recombinant human interleukin-2 and oral 13-cis-retinoic acid. There were two (7%) complete responses (CRs) and eight (27%) partial remissions (PRs), for an overall objective response rate of 34% (95% CI 17–53%). Except one, all responses are ongoing, with a median duration of 9+ and 8+ months for CRs and PRs, respectively. Additionally, 12 patients (40%) reached stable disease. Eight patients (27%) showed continued disease progression despite treatment. Therapy was well tolerated and was given in the outpatient setting. Capecitabine-related World Health Organization (WHO) grade 2 and 3 toxicities were observed in five and two patients respectively, and were limited to fatigue, nausea/vomiting, diarrhoea, stomatitis, dermatitis and hand-and-foot syndrome. The substitution of capecitabine for 5-FU in the pre-existing biochemotherapy regimen did not result in a reduced therapeutic efficacy and showed significant anti-tumour activity in patients with advanced renal cell carcinoma. © 2000 Cancer Research Campaig

    Role of Elastic Projectile-Electron Scattering in Double Ionization of Helium by Fast Proton Impact

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    We present a systematic study of atomic four-body fragmentation dynamics. To this end we have measured a variety of multiple differential double ionization cross sections for 6 MeV p+He collisions. The data are compared to a first-order calculation with correlated electrons and to a simulation representing a second-order process, with some experimental results seemingly in favor of the first, others in agreement with the second approach. This apparent conflict can be resolved by accounting for elastic scattering between the projectile and one electron already promoted to the continuum through electron-electron correlation in the first-order process
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