The effects of human interferon-alpha upon in vitro canine immune responses

The effects of varying amounts (100.0-0.01 units/ml) of human interferon (IFN) alpha upon in vitro canine immune responses were studied. Exogenous heterologous species IFN-alpha suppressed B-cell differentiation in a dose-dependent fashion and enhanced interleukin-2 production (P less than 0.05) by activated T-lymphocytes. Interferon enhanced natural killer (NK) cytotoxicity when tested against NK-resistant target cells (less than 0.05). One hundred units IFN/ml increased interleukin-1 production by canine monocytes, but this effect was not statistically significant. Exogenous IFN had no discernible effect upon lectin-induced lymphocyte blastogenesis. The results of this study demonstrate that human IFN-alpha does affect various canine lymphocyte functions and these effects depend upon the in vitro assay system employed.     

Use of an avidin-biotin enhanced dot-immunobinding assay to detect antibodies for avian mycoplasma in sera from Iowa market turkeys

A dot-immunobinding assay, amplified with avidin and biotin (DAB assay), was used to detect serum antibodies to Mycoplasma iowae in immunized turkeys. The DAB assay was used to test serum samples from 122 commercial market turkey flocks obtained from four Iowa processing plants. The samples were pooled and tested for the presence of antibodies to four species of Mycoplasma spp. considered to be important pathogens for turkeys: M. gallisepticum (MG), M. iowae (MI), M. meleagridis (MM), and M. synoviae (MS). The occurrence of antibodies against these mycoplasmas, as determined by the DAB assay, were 5.7% for MG, 18.0% for MI, 77.9% for MM, and 9.8% for MS.     

Farm management factors associated with bulk tank total bacterial count in Irish dairy herds during 2006/07

Research has shown that total bacterial count (TBC), which is the bacterial growth per ml of milk over a fixed period of time, can be decreased by good hygiene and farm management practices. The objective of the current study was to quantify the associations between herd management factors and bulk tank TBC in Irish spring calving, grass-based dairy herds. The relationship between bulk tank TBC and farm management and infrastructure was examined using data from 400 randomly selected Irish dairy farms where the basal diet was grazed grass. Herd management factors associated with bulk tank TBC were identified using linear models with herd annual total bacterial score (i.e., arithmetic mean of the natural logarithm of bulk tank TBC) included as the dependent variable. All herd management factors were individually analysed in a separate regression model, that included an adjustment for geographical location of the farm. A multiple stepwise regression model was subsequently developed. Median bulk tank TBC for the sample herds was 18,483 cells/ml ranging from 10,441 to 130,458 cells/ml. Results from the multivariate analysis indicated that the following management practices were associated with low TBC; use of heated water in the milking parlour; participation in a milk recording scheme; and tail clipping of cows at a frequency greater than once per year. Increased level of hygiene of the parlour and cubicles were also associated with lower TBC. Herd management factors associated with bulk tank TBC in Irish grazing herds were generally in agreement with most previous studies from confinement systems of milk production.     

Sum rules and interlayer conductivity of high-Tc cuprates

Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition.     

The Current State of Solar Modeling

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.     

THE EFFECT OF LICE INFESTATION ON THE GROWTH OF HEREFORD CALVES

SUMMARY Two experiments were carried out to examine the effects of cattle lice on the productivity of young calves. In both experiments the main species present was Linognathus vituli. In the first experiment, treatment of grazing heifers and their suckled calves did not improve the overall bodyweight gain of either the heifers or the calves. The calves experienced a rapid build-up in lice populations during autumn and early winter which was associated with mild transient pathogenic effects, but this was followed by an apparent ‘self-cure’ reaction and compensatory gain during late winter. In the second experiment young calves were placed in feedlots and fed high and low planes of nutrition. Treatment to remove lice did not result in any improvements in growth rate on either plane of nutrition; however it was clear that untreated, undernourished calves had heavier lice infestation.     

Climate Change During the Last Deglaciation in Antarctica

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.