Myxozoan pathogens in cultured Malaysian fishes. I. Myxozoan infections of the sutchi catfish Pangasius hypophthalmus in freshwater cage cultures

Cage-cultured sutchi catfish Pangasius hypophthalmus (Sauvage, 1878), a favourite food fish in Southeast Asia, proved to be infected by 6 myxozoan species. Three species belonged to the genus Hennegoides (H. berlandi, H. malayensis, and H. pangasii), 1 to Henneguya (H. shariffi) and 2 to Myxobolus (M. baskai, and M. pangasii). Five myxozoans infected the gills and 1 was found on the spleen. Myxozoans infecting the gills were characterised by a specific site selection. H. shariffi sp. n. and H. berlandi sp. n. formed plasmodia in the multi-layered epithelium of the gill filaments. Of the 2 vascular species H. pangasii sp. n. developed in the gin arteries, while M. baskai sp. n. infected the capillary network of the gill lamellae. Plasmodia of H. malayensis sp. n. were found inside the cartilaginous gill rays of the filaments. Large plasmodia of M. pangasii sp. n. were located in a groove of the spleen but they affected only the serosa layer covering the spleen

Electron acceleration sites in a large-scale coronal structure

Radio observations and interplanetary particle measurements have shown that even in the absence of conspicuous violent processes in the low atmosphere (such as Hα flares) electrons are accelerated in the corona, most likely at higher altitudes than during flares (≥0.5 R above the photosphere). The paper presents direct evidence on the acceleration sites from a case study of radio, visible light and soft X-ray observations: electrons are repeatedly accelerated in a large-scale coronal structure which is identified with a streamer in coronographic observations. Energy is simultaneously released in an active region near the base of the structure and at a height of ∼1 R , over several hours before the large-scale structure erupts. Energy input is observed in at least two emerging active regions underneath the streamer. The coronal configuration is three-dimensional, overlying a whole quadrant of the Sun. It is argued that the observations trace multiple sites of energy release presumably in current sheets embedded within the streamer, in agreement with scenarios developed for the acceleration of electrons seen in the corona and at 1 AU, and for the evolution of large-scale coronal structures towards eruption

Static QˉQ\bar{Q}Q pair free energy and screening masses from correlators of Polyakov loops: continuum extrapolated lattice results at the QCD physical point

We study the correlators of Polyakov loops, and the corresponding gauge invariant free energy of a static quark-antiquark pair in 2+1 flavor QCD at finite temperature. Our simulations were carried out on $N_t$ = 6, 8, 10, 12, 16 lattices using Symanzik improved gauge action and a stout improved staggered action with physical quark masses. The free energies calculated from the Polyakov loop correlators are extrapolated to the continuum limit. For the free energies we use a two step renormalization procedure that only uses data at finite temperature. We also measure correlators with definite Euclidean time reversal and charge conjugation symmetry to extract two different screening masses, one in the magnetic, and one in the electric sector, to distinguish two different correlation lengths in the full Polyakov loop correlator

Curvature of the phase transition line in the mu-T plane

We determined the curvature of the phase transition line in the mu-T plane using a Taylor expansion in mu. The Polyakov loop and the strange quark number susceptibility were measured to locate the pseudocritical line. The analysis was carried out on Nt=4,6,8,10 lattices generated with a Symanzik improved gauge and stout-link improved (2+1) flavour staggered fermion action using physical quark masses.Comment: 7 pages, 5 figures; format adjuste

Leptonic decay-constant ratio fK/fπf_K/f_\pi from lattice QCD using 2+1 clover-improved fermion flavors with 2-HEX smearing

We present a calculation of the leptonic decay-constant ratio $f_K/f_\pi$ in 2+1 flavor QCD. Our data set includes five lattice spacings and pion masses reaching down below the physical one. Special emphasis is placed on a careful study of all systematic uncertainties, especially the continuum extrapolation. Our result is perfectly compatible with the first-row unitarity constraint of the Standard Model.Comment: 19 pages, 6 figures, 3 tables; v2: added supplementary analysis, version published in Phys. Rev.

Systematic errors in partially-quenched QCD plus QED lattice simulations

At the precision reached in current lattice QCD calculations, electromagnetic effects are becoming numerically relevant. Here, electromagnetic effects are included by superimposing $\mathrm{U}(1)$ degrees of freedom on $N_f = 2+1$ QCD configurations from the Budapest-Marseille-Wuppertal Collaboration. We present preliminary results for the electromagnetic corrections to light pseudoscalars mesons masses and discuss some of the associated systematic errors.Comment: 7 pages, 2 figures, The XXIX International Symposium on Lattice Field Theory, July 10-16, 2011, Squaw Valley, Lake Tahoe, California, US

Kinetic Inertness of the Mn Complexes Formed with AAZTA and Some Open-Chain EDTA Derivatives

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Relationships among Members of the Genus Myxobolus (Myxozoa: Bilvalvidae) Based on Small Subunit Ribosomal DNA Sequences

Sequences representing similar to 1,700 base pairs of the 18S rRNA gene from 10 different species in the genus Myxobulus were found to group them into 3 clusters that showed little correlation with spore morphology and size or host specificity, criteria currently used for both higher and lower taxonomic placements in the Myxozoa. Of the phenotypic criteria examined, tissue tropism was most correlated with the rRNA groupings observed. Spores of similar size and shape (Myxobolus cerebralis vs. Myxobolus squamalis) were distantly related in some instances, whereas spores with divergent morphology and size were some times found to be closely related (M. cerebralis and Myxobolus insidiosus). These initial investigations into the phylogenetic relationships of putative members of the genus Myxobolus clearly indicate the potential limitations of groupings based on size and morphological properties of the spores and host species infected. We propose that 18S rRNA gene sequences, combined with information on tissue tropism, host species infected, and developmental cycles in the fish and alternate host (when and if known) be given greater consideration in taxonomic placements of myxosporeans