1,650 research outputs found

    Log-Poisson Hierarchical Clustering of Cosmic Neutral Hydrogen and Ly-alpha Transmitted Flux of QSO Absorption Spectrum

    Full text link
    we study, in this paper, the non-Gaussian features of the mass density field of neutral hydrogen fluid and the Ly-alpha transmitted flux of QSO absorption spectrum from the point-of-view of self-similar log-Poisson hierarchy. It has been shown recently that, in the scale range from the onset of nonlinear evolution to dissipation, the velocity and mass density fields of cosmic baryon fluid are extremely well described by the She-Leveque's scaling formula, which is due to the log-Poisson hierarchical cascade. Since the mass density ratio between ionized hydrogen to total hydrogen is not uniform in space, the mass density field of neutral hydrogen component is not given by a similar mapping of total baryon fluid. Nevertheless, we show, with hydrodynamic simulation samples of the concordance Λ\LambdaCDM universe, that the mass density field of neutral hydrogen, is also well described by the log-Poisson hierarchy. We then investigate the field of Lyα\alpha transmitted flux of QSO absorption spectrum. Due to redshift distortion, Lyα\alpha transmitted flux fluctuations are no longer to show all features of the log-Poisson hierarchy. However, some non-Gaussian features predicted by the log-Poisson hierarchy are not affected by the redshift distortion. We test these predictions with the high resolution and high S/N data of quasars Lyα\alpha absorption spectra. All results given by real data, including β\beta-hierarchy, high order moments and scale-scale correlation, are found to be well consistent with the log-Poisson hierarchy. We compare the log-Poisson hierarchy with the popular log-normal model of the Lyα\alpha transmitted flux. The later is found to yield too strong non-Gaussianity at high orders, while the log-Poisson hierarchy is in agreement with observed data.Comment: 24 pages, 9 figures, accepted by Ap

    Mapping quantitative trait loci for T lymphocyte subpopulations in peripheral blood in swine

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Increased disease resistance through improved general immune capacity would be beneficial for the welfare and productivity of farm animals. T lymphocyte subpopulations in peripheral blood play an important role in immune capacity and disease resistance in animals. However, very little research to date has focused on quantitative trait loci (QTL) for T lymphocyte subpopulations in peripheral blood in swine.</p> <p>Results</p> <p>In the study, experimental animals consist of 446 piglets from three different breed populations. To identify QTL for T lymphocyte subpopulations in peripheral blood in swine, the proportions of CD4+, CD8+, CD4+CD8+, CD4+CD8-, CD4-CD8+, and CD4-CD8- T cells and the ratio of CD4+:CD8+ T cells were measured for all individuals before and after challenge with modified live CSF (classical swine fever) vaccine. Based on the combined data of individuals from three breed populations, genome-wide scanning of QTL for these traits was performed based on a variance component model, and the genome wide significance level for declaring QTL was determined via permutation tests as well as FDR (false discovery rate) correction. A total of 27 QTL (two for CD4+CD8+, one for CD4+CD8-, three for CD4-CD8+, two for CD4-CD8-, nine for CD4+, two for CD8+, and eight for CD4+:CD8+ ratio) were identified with significance level of <it>FDR </it>< 0.10, of which 11 were significant at the level of <it>FDR </it>< 0.05, including the five significant at <it>FDR </it>< 0.01.</p> <p>Conclusions</p> <p>Within these QTL regions, a number of known genes having potential relationships with the studied traits may serve as candidate genes for these traits. Our findings herein are helpful for identification of the causal genes underlying these immune-related trait and selection for immune capacity of individuals in swine breeding in the future.</p

    (3E,5E)-3,5-Bis(4-hy­droxy-3,5-di­methoxy­benzyl­idene)oxan-4-one monohydrate

    Get PDF
    In the title compound, C23H24O8·H2O, the six-membered ring of the oxan-4-one (tetra­hydro­pyran-4-one) ring displays an envelope conformation with the heterocyclic O atom at the flap position. The dihedral angles between the terminal benzene rings is 37.23 (10)°. Classical intermolecular O—H⋯O and weak C—H⋯O hydrogen bonds are present in the crystal structure

    Surgical treatment of multivalvular endocarditis: Twenty-one–year single center experience

    Get PDF
    ObjectiveLittle information is available about surgical outcomes in patients with multivalvular endocarditis. The aim of this article is to review the 21-year experience with surgical treatment of patients with multivalvular endocarditis at our institution and, in particular, to determine the incidence, pathologic status, diagnosis, surgical strategies, and outcomes of patients with this disease.MethodsFrom January 1986 to December 2006, a total of 48 patients (40 men, 8 women), with a mean age of 42 ± 12 years, underwent surgery for multivalvular endocarditis. Endocarditis was active in 32 patients and healed in 16. Preoperative transthoracic echocardiographic evaluation was performed in all 48 patients with addition of transesophageal echocardiography in 22 (45.8%). Intraoperative findings showed that the endocarditis involved mostly the mitral and aortic valves (40/48 patients). Triple or quadruple valve involvement was found in 1 and 2 patients, respectively. Preoperative, perioperative, and postoperative data were retrospectively analyzed and risk factors for early and late survival were determined.ResultsIn only 24 (50.0%) patients was multivalvular endocarditis diagnosed by preoperative transthoracic echocardiography; 17 (77.3%) patients had multivalvular endocarditis confirmed by preoperative transesophageal echocardiography. The 30-day hospital mortality was 12.5% (n = 6). Preoperative renal failure, New York Heart Association class IV, and emergency surgery were identified as independent risk factors for hospital mortality. Overall long-term survival was 74% ± 6% at 5 years and 62% ± 3% at 10 years. Multivariate analysis revealed that renal failure and recurrent endocarditis were associated with increased late mortality. Ten-year freedom from recurrent endocarditis was 74% ± 5% and 10-year freedom from reoperation was 73% ± 6%.ConclusionsIn our institution, multivalvular endocarditis was diagnosed by transthoracic echocardiography in only half of the patients. Intraoperative transesophageal echocardiography provided a more effective means to identify this disease. Radical resection of all infected tissues for patients with multivalvular endocarditis and additional intraoperative interventions, depending on the intraoperative pathologic condition, produced satisfactory in-hospital and long-term results, similar to those in patients with a single infected heart valve

    A tetra­nuclear cobalt(III) cluster with 2-(hydroxy­meth­yl)pyridine ligands

    Get PDF
    In the title compound, tetra­kis[μ3-(2-pyrid­yl)methano­lato]tetra­kis[bromido(methanol)cobalt(III)] tetra­bromide 2-(hydroxy­meth­yl)pyridine tetra­solvate dihydrate, [Co4Br4(C6H6NO)4(CH3OH)4]Br4·4C6H7NO4·2H2O, the cation comprises a [Co4O4] cubane-type core ( symmetry). The four CoIII ions and bridging O atoms from four (2-pyrid­yl)methano­late anions are located at alternating vertices of the cube, with bromide ions and methanol ligands on the exterior of the core, completing a distorted octa­hedral geometry. The structure is stablized by inter­molecular O—H⋯Br and O—H⋯O inter­actions

    MMP7 expression regulated by endocrine therapy in ERβ-positive colon cancer cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Many studies have shown that colon cancer is an estrogen-dependent carcinoma. This study explored the efficacy of endocrine therapy in colon cancer cells with high metastatic potential (HT29). We investigated the proliferation of HT29 cells after exposure to endocrine therapy (tamoxifen) and 5-FU.</p> <p>Methods</p> <p>Apoptosis was evaluated using flow cytometry. The expression of matrix metalloproteinases 7 (MMP-7) and estrogen receptor beta (ERβ) was measured by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. The migration capability of treated cells was determined with wound scratch assay.</p> <p>Results</p> <p>Tamoxifen alone, 5-FU alone, and the combination of the two drugs can significantly inhibit HT29 cell proliferation and migration, block the cells in G<sub>2</sub>/M phase and induce cell apoptosis. These drugs also can down-regulate MMP7 and ERβ expression.</p> <p>Conclusion</p> <p>Our findings suggest that endocrine therapy is an efficient therapy for inhibiting ERβ-positive colon cancer cell proliferation and migration via down-regulation of MMP7.</p
    corecore