Periodate oxidation and degradation studies on the major water-soluble arabinoxylan in rye grain

The major water-soluble arabinoxylan from rye grain has previously been shown to contain a main chain of 4-linked β- -xylopyranosyl residues in which, on average, every second is substituted at position 3 with terminal - -arabinofuranosyl residues. Periodate oxidation, reduction and fragmentation by mild acid hydrolysis produced a series of glycerol xylosides containing 4-linked xylopyranosyl residues linked at the reducing end to position 2 of glycerol. It was shown that a one-step periodate oxidation was incomplete due to the formation of relatively stable hemiacetal linkages. A sequential oxidation and reduction procedure was used to bring about complete oxidation of arabinose and unbranched xylose residues in the intact polysaccharide. Quantitative analysis of the products liberated by mild acid hydrolysis revealed the presence of glycerol xylosides with one, two or three xylose residues in the molar ratio of 1·00:0·86:0·02. The xylose residues must have originated from branched residues in the main chain of the arabinoxylan. The units or small blocks of two residues are therefore distributed mainly as isolated branched residues and not randomly as previously reported.     

Environmental contamination by vancomycin resistant enterococci (VRE) in Swedish broiler production

Background  

Vancomycin resistant enterococci are a frequent cause of nosocomial infections and their presence among farm animals is unwanted. Using media supplemented with vancomycin an increase in the proportion of samples from Swedish broilers positive for vancomycin resistant enterococci has been detected. The situation at farm level is largely unknown. The aims of this study were to obtain baseline knowledge about environmental contamination with vancomycin resistant enterococci in Swedish broiler production and the association between environmental contamination and colonisation of birds.     

Taxonomic and biological notes on a species of Iphitime (Polychaeta, Eunicida) associated with Pagurus prideaux from western Norway

On the basis of 658 specimens collected over an 11 year period, the symbiotic eunicid polychaete, Iphitime paguri Fage & Legendre, 1934, is redescribed, and its biology in its presumed preferred host, Pagurus prideaux Leach, 1815, is outlined. The main ecological part is based on sampling of Pagurus on five occasions throughout a year in Raunefjorden, southwest of Bergen. Iphitime paguri turned out to have a strong sexual dimorphism, both in outer appearance and in the morphology of the jaws. Both juveniles and mature individuals of both genders are described. The infestation rate of Pagurus prideaux was very high (as opposed to the low reported infestation rate in Pagurus bernhardus, generally regarded as the host of this species) and the symbiotic polychaetes turned out to have a distinct pattern of host utilization in different life stages. Ripe males and females were, at certain times of the year, generally found more or less intertwined in the apex of the gastropod shell inhabited by its host. Small larval stages were found in the same place. Intermediate size groups were found in the gill chamber and in a sulcus on the carapax of the pagurid host.     

Labeling with fluorescent carbocyanine dyes of cultured endothelial and smooth muscle cells by growth in dye-containing medium.

We describe a method for labeling cultured endothelial cells (ECs) and smooth muscle cells (SMCs) by letting the cells grow for three days in culture medium containing a low concentration of the fluorescent carbocyanine dyes DiI and DiO. We show that good labeling can be obtained with considerably lower concentrations (2.5 micrograms/ml) than has previously been described. With optimal concentration the labeling is very strong and seems to label all membranous structures in the cells. It was possible to clearly distinguish differentially pre-labeled cells both in coculture and seeded on denaturated vascular grafts. The cells remain fluorescent for more than seven days and may be passaged with retained proliferative capability. We suggest that DiI/DiO-labeling using dye-containing medium may be used for several cell types and is applicable in tissue culture and in the detection of implanted cells in vivo.     

Clinical mastitis in ewes; bacteriology,epidemiology and clinical features

Background  

Clinical mastitis is an important disease in sheep. The objective of this work was to identify causal bacteria and study certain epidemiological and clinical features of clinical mastitis in ewes kept for meat and wool production.     

Growth and sex ratio of nestlings in two species of crows: how important is hatching asynchrony?

Summary In experimental studies of avian hatching paterns offspring sex has been neglected. This may be a problem if nestling growth and mortality is sex biased, and if this bias is influenced by hatching spread. In a field study of two crow species, the magpie Pica pica and the hooded crow Corvus corone cornix, we manipulated hatching spread. Both species have asynchronous hatching, and adult males are larger than females by 12–14%. The sex ratios obtained from the different experimental groups on day 24 post-hatch (total sample n = 403) did not deviate significantly from unity, nor did the sex ratios obtained among young newly hatched in an incubator (total sample n = 305). Male and female offspring were of similar size at hatching but males were larger on day 24 post-hatch. Males seemed to be more costly to rear than females, judging by the 20% difference in the mean amounts of food found in the gizzards of the young on day 24 post-hatch. Dimorphism in body size did not seem to be influenced by degree of hatching spread. Asynchronous hatching did not seem to be needed to produce high quality offspring of the larger sex (i.e. males), nor did asynchronous hatching help to ensure equal parental investment in male and female progeny. One reason for the latter negative results may be that the size dimorphism of the two crow species studied were relatively small.