283 research outputs found

    Nonlocal Lie primitive subgroups of Lie groups

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    Nonlocal Lie primitive subgroups of Lie groups

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    AbstractBorovik found a Lie primitive subgroup of E8(ℂ) isomorphic to (Alt5 × Sym6) : 2. In this note, we provide a short proof of existence and his result that the conjugacy class of this subgroup is the only one among those of non-local Lie primitive subgroups of finite dimensional simple complex Lie groups having a socle with more than one simple factor.</jats:p

    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei

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    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for Λ\Lambda-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the Λ\Lambda, Λc+\Lambda_c^+ and Λb\Lambda_b in the corresponding hypernuclei multiplet which has the same baryon numbers are quite similar, the wave functions obtained, e.g., for 1s1/21s_{1/2} state, are very different. The Λc+\Lambda^+_c baryon density distribution in Λc+209^{209}_{\Lambda^+_c}Pb is much more pushed away from the center than that for the Λ\Lambda in Λ209^{209}_\LambdaPb due to the Coulomb force. On the contrary, the Λb\Lambda_b baryon density distributions in Λb\Lambda_b-hypernuclei are much larger near the origin than those for the Λ\Lambda in the corresponding Λ\Lambda-hypernuclei due to its heavy mass. It is also found that level spacing for the Λb\Lambda_b single-particle energies is much smaller than that for the Λ\Lambda and Λc+\Lambda^+_c.Comment: Latex, 14 pages, 4 figures, text was extended, version to appear in Phys. Rev.

    Economic outcomes of percutaneous coronary intervention with drug-eluting stents versus bypass surgery for patients with left main or three-vessel coronary artery disease: One-year results from the SYNTAX trial

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    Objectives: To evaluate the cost-effectiveness of alternative approaches to revascularization for patients with three-vessel or left main coronary artery disease (CAD). Background: Previous studies have demonstrated that, despite higher initial costs, long-term costs with bypass surgery (CABG) in multivessel CAD are similar to those for percutaneous coronary intervention (PCI). The impact of drug-eluting stents (DES) on these results is unknown. Methods: The SYNTAX trial randomized 1,800 patients with left main or three-vessel CAD to either CABG (n = 897) or PCI using paclitaxel-eluting stents (n = 903). Resource utilization data were collected prospectively for all patients, and cumulative 1-year costs were assessed from the perspective of the U.S. healthcare system. Results: Total costs for the initial hospitalization were 5,693/patienthigherwithCABG,whereasfollowupcostswere5,693/patient higher with CABG, whereas follow-up costs were 2,282/patient higher with PCI due mainly to more frequent revascularization procedures and higher outpatient medication costs. Total 1-year costs were thus 3,590/patienthigherwithCABG,whilequalityadjustedlifeexpectancywasslightlyhigherwithPCI.AlthoughPCIwasaneconomicallydominantstrategyfortheoverallpopulation,costeffectivenessvariedconsiderablyaccordingtoangiographiccomplexity.Forpatientswithhighangiographiccomplexity(SYNTAXscore>32),total1yearcostsweresimilarforCABGandPCI,andtheincrementalcosteffectivenessratioforCABGwas3,590/patient higher with CABG, while quality-adjusted life expectancy was slightly higher with PCI. Although PCI was an economically dominant strategy for the overall population, cost-effectiveness varied considerably according to angiographic complexity. For patients with high angiographic complexity (SYNTAX score > 32), total 1-year costs were similar for CABG and PCI, and the incremental cost-effectiveness ratio for CABG was 43,486 per quality-adjusted life-year gained. Conclusions: Among patients with three-vessel or left main CAD, PCI is an economically attractive strategy over the first year for patients with low and moderate angiographic complexity, while CABG is favored among patients with high angiographic complexity

    Hermitian K-theory and 2-regularity for totally real number fields

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    We completely determine the 2-primary torsion subgroups of the hermitian K-groups of rings of 2-integers in totally real 2-regular number fields. The result is almost periodic with period 8. We also identify the homotopy fibers of the forgetful and hyperbolic maps relating hermitian and algebraic K-theory. The result is then exactly periodic of period 8. In both the orthogonal and symplectic cases, we prove the 2-primary hermitian Quillen-Lichtenbaum conjecture.Comment: To appear in Mathematische Annale

    Correlations between the peak flux density and the position angle of inner-jet in three blazars

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    We aim to investigate the relation between the long-term flux density and the position angle (PA) evolution of inner-jet in blazars. We have carried out the elliptic Gaussian model-fit to the `core' of 50 blazars from 15 GHz VLBA data, and analyzed the variability properties of three blazars from the model-fit results. Diverse correlations between the long-term peak flux density and the PA evolution of the major axis of the `core' have been found in \sim 20% of the 50 sources. Of them, three typical blazars have been analyzed, which also show quasi-periodic flux variations of a few years (T). The correlation between the peak flux density and the PA of inner-jet is positive for S5~0716+714, and negative for S4~1807+698. The two sources cannot be explained with the ballistic jet models, the non-ballistic models have been analyzed to explain the two sub-luminal blazars. A correlation between the peak flux density and the PA (with a T/4 time lag) of inner-jet is found in [HB89]~1823+568, this correlation can be explained with a ballistic precession jet model. All the explanations are based mainly on the geometric beaming effect; physical flux density variations from the jet base would be considered for more complicated situations in future, which could account for the no or less significance of the correlation between the peak flux density and the PA of inner-jet in the majority blazars of our sample.Comment: 6 pages, 7 figures, accepted for publication in Astrophysics and Space Scienc

    Error sources and data limitations for the prediction ofsurface gravity: a case study using benchmarks

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    Gravity-based heights require gravity values at levelled benchmarks (BMs), whichsometimes have to be predicted from surrounding observations. We use EGM2008 andthe Australian National Gravity Database (ANGD) as examples of model and terrestrialobserved data respectively to predict gravity at Australian national levelling network(ANLN) BMs. The aim is to quantify errors that may propagate into the predicted BMgravity values and then into gravimetric height corrections (HCs). Our results indicatethat an approximate ±1 arc-minute horizontal position error of the BMs causesmaximum errors in EGM2008 BM gravity of ~ 22 mGal (~55 mm in the HC at ~2200 melevation) and ~18 mGal for ANGD BM gravity because the values are not computed atthe true location of the BM. We use RTM (residual terrain modelling) techniques toshow that ~50% of EGM2008 BM gravity error in a moderately mountainous regioncan be accounted for by signal omission. Non-representative sampling of ANGDgravity in this region may cause errors of up to 50 mGals (~120 mm for the Helmertorthometric correction at ~2200 m elevation). For modelled gravity at BMs to beviable, levelling networks need horizontal BM positions accurate to a few metres, whileRTM techniques can be used to reduce signal omission error. Unrepresentative gravitysampling in mountains can be remedied by denser and more representative re-surveys,and/or gravity can be forward modelled into regions of sparser gravity

    Statistical Mechanics of Horizontal Gene Transfer in Evolutionary Ecology

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    The biological world, especially its majority microbial component, is strongly interacting and may be dominated by collective effects. In this review, we provide a brief introduction for statistical physicists of the way in which living cells communicate genetically through transferred genes, as well as the ways in which they can reorganize their genomes in response to environmental pressure. We discuss how genome evolution can be thought of as related to the physical phenomenon of annealing, and describe the sense in which genomes can be said to exhibit an analogue of information entropy. As a direct application of these ideas, we analyze the variation with ocean depth of transposons in marine microbial genomes, predicting trends that are consistent with recent observations using metagenomic surveys.Comment: Accepted by Journal of Statistical Physic
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