Functional additive effect of H blood group alleles on carcass length in Danish landrace pigs.

Previous investigations have revealed statistically significant associations between H blood group genotypes and carcass length in Danish Landrace pigs. The same data were subjected to an analysis aimed at a genetic interpretation of the associations. The regression of the average carcass length (in cm) on the average number of H- alleles for individuals within three genetically characterized classes was 0.725 and the correlation coefficient was 0.995. The results indicate that the associations can be interpreted as being due to an additive effect of the H blood group alleles on carcass length. The additive effect is designated as being functional. A similar effect is expected with respect to any allelic pair exhibiting linkage disequilibrium with alleles at the H locus.     

Astronomy and Solar Physics: X-ray Gas Scintillation Spectrometer Experiment

The payload complement on Spacelab 1 included a spectrometer for observations of the brighter cosmic x-ray sources. The primary scientific objective was to study the detailed spectral features of cosmic x-ray sources and their associated temporal variations over a wide energy range from about 2 to 80 kiloelectron volts. The instrument, based on the gas scintillation proportional counter, had a geometrical area of some 180 square centimeters with an energy resolution of about 9 percent at 7 kiloelectron volts. The results presented here show new results from two galactic binary x-ray sources, Cygnus X-3 and Centaurus X-3, and from the Perseus cluster of galaxies. The excellent energy resolution of the instrument permits line features to be identified in these sources with unprecedented quality.     

Campylobacter jejuni strains of human and chicken origin are invasive in chickens after oral challenge

The aim of the study was to evaluate the colonizing ability and the invasive capacity of selected Campylobacter jejuni strains of importance for the epidemiology of C jejuni in Danish broiler chickens. Four C. jejuni strains were selected for experimental colonization studies in day-old and 14-day-old chickens hatched from specific pathogen free (SPF) eggs. Of the four C. jejuni strains tested, three were Penner heat-stable serotype 2, flaA type 1/1, the most common type found among broilers and human cases in Denmark. The fourth strain was Penner heat-stable serotype 19, which has been shown to be associated with the Guillain Barré Syndrome (GBS) in humans. The minimum dose for establishing colonization in the day-old chickens was approximately 2 cfu, whereas two- to threefold higher doses were required for establishing colonization in the 14-day-old chickens. Two of the C. jejuni strains were shown to be invasive in orally challenged chickens as well as in three different human epithelial cell lines.     

Possibilities of contraception, artificial abortion and premature labor in cattle

Means of contraception and abortion in cattle are discussed. Estrog en injections (diethylstilbestrol or estradiol benzoate) may be given within a few days of conception, as may oxytocin and prostaglandins. Infusion of a sterile solution into the uterus is another means of inducing abortion. Intrarectal applications of estrogens can also be used to suppress the corpus luteum. Later in pregnancy, injury to the fetus or the membranes, or surgical removal of the fetus are possible. Estrogen or corticosteroid treatment may also be used to induce labor. Because the sperm must be immobilized before they reach the tubes, contraception is difficult to carry out in practice.