Cyanobacteria are the predominant phototrophs in freshwater ecosystems of the polar regions where they commonly form extensive benthic mats. Despite their major biological role in these ecosystems, little attention has been paid to their physiology and biochemistry. An important feature of cyanobacteria from the temperate and tropical regions is the production of a large variety of toxic second...

The resistance profile and its correlation with mobile genetic elements were investigated in 11 Vibrio cholerae O1 and 2 Vibrio parahaemolyticus clinical isolates, as well as in 1 V. cholerae O1 and 1 V. cholerae non-O1 environmental isolate, isolated between 1991 and 1996 in different provinces of Angola. All clinical isolates of V. cholerae O1 were resistant to ampicillin, chloramphenicol, tr...

We show how to estimate the size of spatially unresolved solar and stellar coronal flaring regions from the X-ray light curve and time-resolved temperature and emission measure values during the flare decay. Bymeans of extensive hydrodynamic modeling of decaying flaring loops, we propose and test a relationship between the decay time of the light curve in the band of a specific instrument and t...

The use of trimethoprim in treatment of Streptococcus pyogenes infections has long been discouraged because it has been widely believed that this pathogen is resistant to this antibiotic. To gain more insight into the extent and molecular basis of trimethoprim resistance in S. pyogenes, we tested isolates from India and Germany and sought the factors that conferred the resistance. Resistant iso...

We study the structure of 107 bright sigmoids using full-resolution (2.5 pixels) images from the Yohkoh Soft X-Ray Telescope (SXT) obtained between 1991 December and 2001 December. We find that none of these sigmoids are made of single loops of S or inverse-S shape; all comprise a pattern of multiple loops. We also find that all S-shaped sigmoids are made of right-bearing loops and all inverse-...

Saxitoxin (STX) and its analogues cause the paralytic shellfish poisoning (PSP) syndrome, which afflicts human health and impacts coastal shellfish economies worldwide. PSP toxins are unique alkaloids, being produced by both prokaryotes and eukaryotes. Here we describe a candidate PSP toxin biosynthesis gene cluster (sxt) from Cylindrospermopsis raciborskii T3. The saxitoxin biosynthetic pathwa...

This study was conducted to find the etiology of acute diarrhea in Iranian children and determine the antimicrobial resistance patterns. The pathogenic bacteria were recovered from 110/269 (40.9%) diarrheal fecal samples with the following profiles: the most predominant pathogen was diarrheagenic Escherichia coli (DEC) (43.6%), comprising enteroaggregative E. coli (23.6%), enteropathogenic E. c...

BACKGROUND Vibrio cholerae is a human intestinal pathogen and V. cholerae of the O139 serogroups are responsible for the current epidemic cholera in China. In this work, we reported the whole genome sequencing of a V. cholerae O139 strain E306 isolated from a cholera patient in the 306th Hospital of PLA, Beijing, China. RESULTS We obtained the draft genome of V. cholerae O139 strain E306 with...

A group of proteic toxin-antitoxin (TA) cassettes whose representatives are widely distributed among bacterial genomes has been identified. These cassettes occur in chromosomes, plasmids, bacteriophages, and noncomposite transposons, as well as in the SXT conjugative element of Vibrio cholerae. The following four homologous loci were subjected to detailed comparative studies: (i) tad-ata from p...

Yohkoh has been dedicated to study the structure and evolution of the solar corona, especially during dynamic events. During such events, however, the collisional equilibrium ionization – which is invariably assumed when deriving the plasma parameters from the observations – may not apply. We explore the influence of the non–equilibrium ionization effects (NEI) on the values of temperature and ...