Haemolytic anaemia in cattle in NSW associated with Theileria infections

Several outbreaks of anaemia, jaundice, abortion and mortality in cattle in New South Wales were attributed to the intracellular parasite, Theileria buffeli . Disease occurred predominantly in periparturient animals that had been moved from inland to coastal areas. Diagnosis was made via exclusion of other causes of haemolytic anaemia and observation of the parasite in blood smears. Treatments included both registered and non-registered products. There is a possibility of a new strain of Theileria sp. in Australia and the possible vectors encountered in NSW are discussed.     

The elbow

Computed tomography (CT) and magnetic resonance imaging (MRI) are noninvasive methods of imaging the canine cubital joint. CT images are typically acquired using contiguous 1-mm slices, a bone reconstruction algorithm, and a field of view large enough to scan both elbows simultaneously. CT provides a detailed assessment of the medial coronoid process (MCP), radial incisure, anconeal process, and trochlear notch of the ulna; the humeral condyle; joint congruity; and osteoarthrosis. With MRI, use of a surface coil and 3D Fourier transformation gradient echo fast imaging sequences allow contiguous thin slices to be obtained. Both imaging techniques appear to be highly effective in the evaluation of elbow dysplasia, particularly for the detection of MCP fragmentation, although MRI is superior to CT for identifying nonmineralized cartilaginous fragments.     

Rotation of a single molecule within a supramolecular bearing

Experimental visualization and verification of a single-molecule rotor operating within a supramolecular bearing is reported. Using a scanning tunneling microscope, single molecules were observed to exist in one of two spatially defined states laterally separated by 0.26 nanometers. One was identified as a rotating state and the other as an immobilized state. Calculations of the energy barrier for rotation of these two states show that it is below the thermal energy at room temperature for the rotating state and above it for the immobilized state.     

Design of a surface alloy catalyst for steam reforming

Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. Insight into the structure of surface alloys combined with an understanding of the relation between the surface composition and reactivity is shown to lead directly to new ideas for catalyst design. The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming.     

Pulmonary ultrasonographic abnormalities associated with naturally occurring equine influenza virus infection in standardbred racehorses

The purpose of this investigation was to determine if naturally occurring acute infectious upper respiratory disease (IRD) caused by equine influenza virus is associated with ultrasonographically detectable pleural and pulmonary abnormalities in horses. Standardbred racehorses were evaluated for signs of IRD, defined as acute coughing or mucopurulent nasal discharge. For every horse with IRD (n = 16), 1 or 2 horses with no signs of IRD and the same owner or trainer (n = 30) were included. Thoracic ultrasonography was performed within 5-10 days of the onset of clinical disease in horses with IRD. Horses without IRD were examined at the same time as the horses with IRD with which they were enrolled. The rank of the ultrasound scores of horses with IRD was compared to that of horses without IRD. Equine influenza virus was identified as the primary etiologic agent associated with IRD in this study. Mild lung consolidation and peripheral pulmonary irregularities were found in 11 (69%) of 16 of the horses with IRD and 11 (37%) of 30 of control horses. Lung consolidation (median score = 1) and peripheral irregularities scores (median score = 1) were greater in horses with IRD compared to horses without IRD (median score = 0; P < .05). Pleural effusion was not observed. Equine influenza virus infection can result in abnormalities of the equine lower respiratory tract. Despite the mild nature of IRD observed in this study, lung consolidation and peripheral pulmonary irregularities were more commonly observed in horses with clinical signs of IRD. Further work is needed to determine the clinical significance of these ultrasonographic abnormalities.     

Chemical manipulation of soil biota in a fescue meadow

Formalin, phorate, and sodium chlorate were used in field enclosures to create artificial habitats in a fescue meadow containing (1) reduced number of earthworms, (2) reduced numbers of earthworms and soil arthropods, and (3) reduction of total soil fauna and rate of microbial decomposition. Under these conditions, confined fescue litter initially decomposed more rapidly where arthropods or earthworms were suppressed than in controls with full complements of soil animals. After one year, reduction in numbers of soil animals had no net effect on litter decomposition, with faunal activity apparently having been compensated for by increased microbial activity. Where animals and microbial activity were reduced, rate of litter loss was depressed initially but recovered after 10 months as the effects of chemical suppression of microbial populations subsided. Contrary to the effects on annual loss of litter, elimination of all or portions of the soil fauna depressed rates of loss of confined and buried roots, reflecting the role of animals in fragmenting roots before their decomposition by microorganisms.Habitat manipulations had pronounced effects on the mobility of ¹³⁴Cs, and loss of the radionuclide from labelled litter was retarded despite an accelerated rate of decomposition. This effect apparently was associated with proliferation of microorganisms on litter and microbial immobilization of the radionuclide. Immobilization of ¹³⁴Cs occurred following chemical perturbations, but only after an initial period of rapid loss resulting from increased microbial activity. Distribution of ¹³⁴Cs in soil beneath tagged litter bags reflected the role of animals in element redistribution within soil. Restricted vertical mobility of the nuclide occurred except where chemical application killed vegetation within the experimental enclosures.