Thermographic selection of effective catalysts from an encoded polymer-bound library

A general method is introduced for the rapid and simultaneous evaluation of each member of large encoded catalyst libraries for the ability to catalyze a reaction in solution. The procedure was used to select active catalysts from a library of potential polymer-bound multifunctional catalysts. From approximately 7000 beads screened (3150 distinct catalysts), 23 beads were selected for catalysis of an acylation reaction. Kinetic experiments indicate that the most strongly selected beads are also the most efficient catalysts.     

Photonic channels for quantum communication

A general photonic channel for quantum communication is defined. By means of local quantum computing with a few auxiliary atoms, this channel can be reduced to one with effectively less noise. A scheme based on quantum interference is proposed that iteratively improves the fidelity of distant entangled particles.     

Prediction of the fractional rate of outflow of water from the rumen of sheep

The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day^?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance.     

A study of the effect of acute systemic anaphylaxis on blood coagulation and TAME esterase activity in calves.

Sensitized and control calves were challenged with an intravenous dose of 0.2 mL/kg horse serum. Changes in the blood pressure, blood cellular components, plasma kaolin activated p-tosyl-1-arginine methyl ester esterase activity, plasma antithrombin III levels and activated partial thromboplastin time were monitored. Anaphylaxis induced a severe drop in carotid arterial pressure and respiratory distress. There was a decrease in the total white blood cell count from a mean of 10,000 to a low of 1,900 per microL, a decrease in the percentage neutrophils and an increase in the percentage of lymphocytes from 57.4% to 94.8%. A drop was observed in the mean platelet count from 463 x 10(3)/microL. The time required for kaolin to produce maximum p-tosyl-1-arginine methyl ester esterase activation increased from two minutes in the controls to three minutes in calves undergoing anaphylaxis and was observed three to 90 minutes after the administration of horse serum. Antithrombin III levels in the plasma appeared to drop during anaphylaxis but were not significantly depressed (p greater than or equal to 0.5). A statistically significant (p < 0.5) drop in the rate of blood coagulation was observed by the activated partial thromboplastin time assay at 15 to 30 minutes after horse serum injection.     

Antibody response in bovine pharyngeal fluid following foot-and-mouth disease vaccination and, or, exposure to live virus

Samples of pharyngeal fluid and serum were collected from cattle after exposure to live foot-and-mouth disease (FMD) virus (with or without prior vaccination) or after subcutaneous vaccination with inactivated virus. The pharyngeal fluid samples were examined for FMD neutralising activity and specific anti-FMD IgG, IgM and IgA antibodies. The neutralising activity of the serum was also monitored. A peak of neutralising activity which occurred in the pharyngeal fluid of unvaccinated cattle seven days after virus exposure corresponded to a rise in specific IgM and IgA antibodies. This peak appeared to be due to serum and tissue fluid escaping from the damaged mucosa during the acute inflammatory phase of infection. At later stages (20 to 60 days after virus exposure) the pharyngeal fluid neutralising activity corresponded to a rise in specific IgA antibodies, suggesting that active local antibody production was taking place. The pharyngeal fluid neutralising activity detected after revaccination with oil emulsion or aqueous vaccines, without exposure to live virus, corresponded to a rise in specific IgG and IgM antibody levels and this may have been due to serum transudation.     

Prevalence of antibodies of Leptospira serovars in beef cattle in central Queensland.

OBJECTIVE: To obtain up-to-date data on the prevalence of antibodies to Leptospira serovars in central Queensland beef herds preliminary to assessing their role in bovine subfertility and the role of cattle as a zoonotic reservoir. DESIGN: Sera from 2857 female cattle in 68 central Queensland beef herds were tested for antibodies to 14 Leptospira serovars using the microscopic agglutination test. Vaccination use and age of cattle were collected to enable the calculation of crude and age-stratified seroprevalences. RESULTS: The most commonly detected antibodies were to serovars hardjo (15.8% crude seroprevalence), tarassovi (13.9%), pomona (4.0%) and szwajizak (2.2%). Vaccinates were omitted from the hardjo and pomona seroprevalence data. The seroprevalence for hardjo and pomona tended to increase with age of the animals. CONCLUSION: These results are broadly similar to those of previous serological surveys. The data suggest that serovars other than hardjo, pomona and tarassovi, are unlikely to have a significant role in bovine subfertility and that cattle are unlikely to be a source of human infection with them in central Queensland.