A MeerKAT view on galaxy clusters: a radio-optical study of Abell 1300 and MACS J1931.8--2634

In this paper we present results from a radio-optical study of the galaxy populations of the galaxy clusters Abell 1300 and MACS J1931.8$-$2634, a merger and a relaxed system respectively both located at $z \sim 0.3$, aimed at finding evidence of merger-induced radio emission. Radio observations are taken at 1.28 GHz with the MeerKAT interferometer during its early-stage commissioning phase, and combined with archive optical data. We generated catalogues containing 107 and 162 radio sources in the A$~$1300 and MACS J1931.8--2634 cluster fields respectively, above a 0.2 mJy threshold and within a 30~arcmin radius from the cluster centre (corresponding to 8.1 and 8.8 Mpc respectively). By cross-correlating the radio and optical catalogues, and including spectroscopic information, 9 and 6 sources were found to be cluster members and used to construct the radio luminosity functions respectively for both clusters. The comparison of the radio source catalogues between the two cluster fields leads to a marginal difference, with a $2\sigma$ statistical significance. We derived the radio luminosity function at 1.28 GHz in both clusters, in the power range $22.81 < \rm {log~P_{1.28~GHz}~(W/Hz)} < 25.95$, and obtained that in A 1300 the radio luminosity function averaged over the full radio power interval is only $3.3 \pm 1.9$ times higher than the MACS J1931.8--2634 one, suggesting no statistical difference in their probability to host nuclear radio emission. We conclude that, at least for the two clusters studied here, the role of cluster mergers in affecting the statistical properties of the radio galaxy population is negligible.Comment: 18 pages, 8 figures, MNRAS accepte

Crystal structure of the catalytic domain of human matrix metalloproteinase 10

The catalytic domain of matrix metalloproteinase-10 (MMP-10) has been expressed in Escherichia coli and its crystal structure solved at 2.1 A resolution. The availability of this structure allowed us to critically examine the small differences existing between the catalytic domains of MMP-3 and MMP-10, which show the highest sequence identity among all MMPs. Furthermore, the binding mode of N-isobutyl-N-[4-methoxyphenylsulfonyl] glycyl hydroxamic acid (NNGH), which is one of the most known commercial inhibitors of MMPs, is described for the first time

Variability in the structural polypeptides of herpes simplex virus 1 strains: potential application in molecular epidemiology

This paper reports on the variability of structural polypeptides of 53 strains of herpes simplex virus 1 isolated from Italy, Uganda, South Africa, and various locations in the United States. Most strains were passaged a limited number of times at low multiplicity outside the human host; a few strains were characterized by numberous passages at variable multiplicities in cell culture and experimental animals. The acrylamide gel electrophoresis of polypeptides from purified virions revealed seven variable polypeptides. Virion polypeptides (VP) 7, 11, 13, 14, 15.2 and 23 were present in at least two isotypic forms characterized by fast and slow electrophoretic mobilities. VP8 could not be detected in three strains. In addition, VP13, 15.2, and 23 in some strains were either absent or comigrated with other polypeptides. A variety of tests showed that the variability in electrophoretic mobility of polypeptides was reproducible and could not be attributed to artifacts of purification, solubilization, or electrophoresis. Attempts to classify the strains on the basis of electrophoretic mobility of five or all seven variable polypeptides yielded 14 and 19 groups, respectively. The bulk of the strains (41 to 53) fell into six groups. Not all possible permutations of variable polypeptides were observed. Comparison of early and late passages of laboratory strains showed that in the few instances tested the variability could not be attributed to the propagation of the virus outside the human host. Clustering of strains on the basis of country of origin was not observed. Some clustering of isolates on the basis of site of isolation was observed, and the data do suggest that further analyses of isolates for evidence of a correlation between the site of localization on the human body and the structural polypeptides might be useful. Electrophoretic characterization of structural polypeptides has the potential of becoming a powerful tool for epidemiological studies of herpes simplex virus infections.</jats:p