416 research outputs found

    Phylogenetic diversity of insecticolous fusaria inferred from multilocus DNA sequence data and their molecular identification via FUSARIUM-ID and Fusarium MLST

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    We constructed several multilocus DNA sequence datasets to assess the phylogenetic diversity of insecticolous fusaria, especially focusing on those housed at the Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF), and to aid molecular identifications of unknowns via the FUSARIUM-ID and Fusarium MLST online databases and analysis packages. Analyses of a 190-taxon, two-locus dataset, which included 159 isolates from insects, indicated that: (i) insect-associated fusaria were nested within 10 species complexes spanning the phylogenetic breadth of Fusarium, (ii) novel, putatively unnamed insecticolous species were nested within 8/10 species complexes and (iii) Latin binomials could be applied with confidence to only 18/58 phylogenetically distinct fusaria associated with pest insects. Phylogenetic analyses of an 82-taxon, three-locus dataset nearly fully resolved evolutionary relationships among the 10 clades containing insecticolous fusaria. Multilocus typing of isolates within four species complexes identified surprisingly high genetic diversity in that 63/65 of the fusaria typed represented newly discovered haplotypes. The DNA sequence data, together with corrected ABI sequence chromatograms and alignments, have been uploaded to the following websites dedicated to identifying fusaria: FUSARIUM-ID (http://isolate.fusariumdb.org) a

    Herd-level risk factors of bovine tuberculosis in England and Wales after the 2001 foot-and-mouth disease epidemic

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    We present the results of a 2005 case–control study of bovine tuberculosis (bTB) breakdowns in English and Welsh herds. The herd management, farming practices, and environmental factors of 401matched pairs of case and control herds were investigated to provide a picture of herd-level risk factors in areas of varying bTB incidence. A global conditional logistic regression model, with region-specific variants, was used to compare case herds that had experienced a confirmed bTB breakdown to contemporaneous control herds matched on region, herd type, herd size, and parish testing interval. Contacts with cattle from contiguous herds and sourcing cattle from herds with a recent history of bTB were associated with an increased risk in both the global and regional analyses. Operating a farm over several premises, providing cattle feed inside the housing, and the presence of badgers were also identified as significantly associated with an increased bTB risk. Steps taken to minimize cattle contacts with neighboring herds and altering trading practices could have the potential to reduce the size of the bTB epidemic. In principle, limiting the interactions between cattle and wildlife may also be useful; however this study did not highlight any specific measures to implement

    Dynamical Properties of Two Coupled Hubbard Chains at Half-filling

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    Using grand canonical Quantum Monte Carlo (QMC) simulations combined with Maximum Entropy analytic continuation, as well as analytical methods, we examine the one- and two-particle dynamical properties of the Hubbard model on two coupled chains at half-filling. The one-particle spectral weight function, A(k,ω)A({\bf k},\omega), undergoes a qualitative change with interchain hopping t⊄t_\perp associated with a transition from a four-band insulator to a two-band insulator. A simple analytical model based on the propagation of exact rung singlet states gives a good description of the features at large t⊄t_\perp. For smaller t⊄t_\perp, A(k,ω)A({\bf k}, \omega) is similar to that of the one-dimensional model, with a coherent band of width the effective antiferromagnetic exchange JJ reasonably well-described by renormalized spin-wave theory. The coherent band rides on a broad background of width several times the parallel hopping integral tt, an incoherent structure similar to that found in calculations on both the one- and two-dimensional models. We also present QMC results for the two-particle spin and charge excitation spectra, and relate their behavior to the rung singlet picture for large t⊄t_\perp and to the results of spin-wave theory for small t⊄t_\perp.Comment: 9 pages + 10 postscript figures, submitted to Phys.Rev.B, revised version with isotropic t_perp=t data include

    Exercise conditioning in old mice improves skeletal muscle regeneration

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    Skeletal muscle possesses the ability to regenerate after injury, but this ability is impaired or delayed with aging. Regardless of age, muscle retains the ability to positively respond to stimuli, such as exercise. We examined whether exercise is able to improve regenerative response in skeletal muscle of aged mice. Twenty‐two‐month‐old male C57Bl/6J mice (n = 20) underwent an 8‐wk progressive exercise training protocol [old exercised (O‐Ex) group]. An old sedentary (O‐Sed) and a sedentary young control (Y‐Ctl) group were included. Animals were subjected to injections of cardiotoxin into the tibialis anterior muscle. The tibialis anterior were harvested before [O‐Ex/O‐Sed/ Y‐Ctl control (CTL); n = 6], 10 d (O‐Ex/O‐Sed/Y‐Ctl d 10; n = 8), and 28 d (O‐Ex/O‐Sed/Y‐Ctl d 28; n = 6) postinjection. Average fiber cross‐sectional area was reduced in all groups at d 10 (CTL: O‐Ex: 2499 ± 140; O‐Sed: 2320 ± 165; Y‐Ctl: 2474 ± 269; d 10: O‐Ex: 1191 ± 100; O‐Sed: 1125 ± 99; Y‐Ctl: 1481 ± 167 ÎŒm2; P 0.05). Satellite cell content was greater at CTL in O‐Ex (2.6 ± 0.4 satellite cells/100 fibers) compared with O‐Sed (1.0 ± 0.1% satellite cells/100 fibers; P < 0.05). Exercise conditioning appears to improve ability of skeletal muscle to regenerate after injury in aged mice.—Joanisse, S., Nederveen, J. P., Baker, J. M., Snijders, T., Iacono, C., Parise, G. Exercise conditioning in old mice improves skeletal muscle regeneration. FASEB J. 30, 3256–3268 (2016)

    Optical and transport properties in doped two-leg ladder antiferromagnet

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    Within the t-J model, the optical and transport properties of the doped two-leg ladder antiferromagnet are studied based on the fermion-spin theory. It is shown that the optical and transport properties of the doped two-leg ladder antiferromagnet are mainly governed by the holon scattering. The low energy peak in the optical conductivity is located at a finite energy, while the resistivity exhibits a crossover from the high temperature metallic-like behavior to the low temperature insulating-like behavior, which are consistent with the experiments.Comment: 13 pages, 5 figures, accepted for publication in Phys. Rev. B65 (2002) (April 15 issue

    Equivalence of 2 effective graft-versus-host disease prophylaxis regimens: Results of a prospective double-blind randomized trial

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    AbstractWe have previously demonstrated a decrease in the incidence of acute graft-versus-host disease (GVHD) with the addition of methotrexate (MTX) to cyclosporine (CSP) and prednisone (PSE) chemotherapy in patients with leukemia. We have now completed a prospective randomized trial comparing the 3-drug regimen (CSP/MTX/PSE, including 3 doses of MTX) to the standard 2-drug regimen (CSP/MTX, including 4 doses of MTX) to investigate the benefit of PSE used up front for the prevention of acute and chronic GVHD. In the trial, 193 patients were randomized and 186 were included in the final analysis. All patients received a bone marrow graft from a fully histocompatible sibling donor. The preparatory regimen consisted of fractionated total-body irradiation (fTBI) and etoposide in all but 13 patients, who received fTBI and cyclophosphamide. The patients were randomized to receive either CSP/MTX/PSE or CSP/MTX. The 2 groups were well balanced with respect to diagnosis, disease stage, age, donor-recipient sex, and parity. In an intent-to-treat analysis, the incidence of acute GVHD was 18% (95% confidence interval [CI] 12-28) for the CSP/MTX/PSE group compared with 20% (CI 10-26) for the CSP/,MTX group (P = .60), with a median follow up of 2.2 years. Overall survival was 65% for those receiving CSP/MTX/PSE and 72% for those receiving CSP/MTX (P = .10); the relapse rate was 15% for the CSP/MTX/PSE group and 12% for the CSP/MTX group (P = .83). The incidence of chronic GVHD was similar (46% versus 52%; P = .38), with a follow-up of 0.7 to 6.0 years. Of interest, 21 patients went off study due to GVHD (5 in the CSP/MTX/PSE group and 16 in the CSP/MITX group [P = .02]), and 11 patients went off study because of alveolar hemorrhage (3 in the CSP/MTX/PSE group and 8 in the CSP/MTX group [P = .22]). The addition of PSE did not result in a higher incidence of infectious complications, bacterial (66% versus 58%), viral (77% versus 66%), or fungal (20% versus 20%), in those receiving CSP/MTX/PSE versus CSP/MTX, respectively. These data suggest that the addition of PSE was associated with a somewhat lower incidence of early posttransplantation complications but did not have a positive impact on the incidence of acute or chronic GVHD or event-free or overall survival.Biol Blood Marrow Transplant 2000;6(3):254-61

    Weak lensing, dark matter and dark energy

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    Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the expansion rate of the universe, and distinguish between modified gravity and dark energy explanations for the acceleration of the universe. We also discuss requirements on the control of systematic errors so that the systematics do not appreciably degrade the power of weak lensing as a cosmological probe.Comment: Invited review article for the GRG special issue on gravitational lensing (P. Jetzer, Y. Mellier and V. Perlick Eds.). V3: subsection on three-point function and some references added. Matches the published versio

    Summary for Policymakers - Marine Ecosystem Assessment for the Southern Ocean

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    i. The Antarctic Treaty System (beginning in 1959 with the Antarctic Treaty) and its emphasis on conservation and protection, exemplified in the Convention on the Conservation of Antarctic Marine Living Resources (1980) and its Protocol on Environmental Protection to the Antarctic Treaty (1991), provide the most recent articulation of the global interest in Antarctica and the Southern Ocean and the need for their protection. ii. The Southern Ocean and its ecosystems play critical roles in the climate system. Ecosystem functions are at risk because of anthropogenic climate change. iii. Global policies and actions are urgently required to safeguard Southern Ocean ecosystems from the effects of climate change, ocean warming and acidification caused by greenhouse gas emissions. iv. Regional human pressures on Southern Ocean species and ecosystems have been dominated by fisheries, with human presence (science and tourism) and pollution having localised, but increasing, impacts. v. The Marine Ecosystem Assessment for the Southern Ocean (MEASO) has demonstrated the array of existing knowledge, data, tools and approaches available for informing decisions on conserving and sustaining the marine ecosystems in the region and the services they provide, and how implementation of those processes could be improved

    Search for Higgs bosons decaying to tautau pairs in ppbar collisions at sqrt(s) = 1.96 TeV

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    We present a search for the production of neutral Higgs bosons decaying into tautau pairs in ppbar collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of 5.4 fb-1, were collected by the D0 experiment at the Fermilab Tevatron Collider. We set upper limits at the 95% C.L. on the product of production cross section and branching ratio for a scalar resonance decaying into tautau pairs, and we then interpret these limits as limits on the production of Higgs bosons in the minimal supersymmetric standard model (MSSM) and as constraints in the MSSM parameter space.Comment: 7 pages, 5 figures, submitted to PL
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