Characterisation of the first Australian isolate of Neospora caninum from cattle

OBJECTIVE: To isolate Neospora caninum from a congenitally infected calf. PROCEDURE: A calf was obtained from a N. caninum infected dam maintained in a dairy herd of Holstein-Friesian cattle located on the south coast of NSW near Nowra. The calf was euthanased and samples collected for serology and pathology. Samples of brain and spinal cord of the calf were homogenised and injected into immunocompromised mice in an attempt to recover protozoa by in vivo culture. Sequential passage of brain homogenate through IFNgammaPKO mice was performed and tissue culture flasks were inoculated with brain homogenate. Parasites were identified by electron microscopy and DNA sequencing. The antigen profile of the isolate was analysed using Western blotting. Pathogenicity was examined in BALB/c mice and transmission of the parasite during pregnancy was examined in Qs mice. RESULTS: The calf was seropositive for N. caninum and histopathological examination of sections of cerebrum identified lesions consistent with a very mild infection with N. caninum. The parasites isolated using tissue culture were identified as N. caninum, based on the sequence of the ribosomal DNA and electron microscopy. The antigen profile of the new isolate was similar to that of the NC-Liverpool isolate, but quite different from that of Toxoplasma gondii. In BALB/c mice inoculated with the new isolate, severe clinical signs developed in only three of ten infected mice, compared with six of ten mice infected with NC-Liverpool. Mild to moderate nonsuppurative encephalitis was observed in BALB/c mice infected with the new isolate, compared with mice infected with NC-Liverpool, that developed severe nonsuppurative encephalitis. Transplacental transmission of the isolate arising from an acute infection during pregnancy occurred in about 87% of pups. CONCLUSION: This is the first isolation of bovine Neospora caninum in Australia. This isolate, called NC-Nowra, appears to be a less virulent form and may prove to be a suitable candidate for vaccine development.     

Meconium impaction in newborn foals

Meconium impactions are one of the most common causes of colic in neonatal foals. It is recommended that foals be administered a sodium phosphate or warm soapy water enema within the first 3 hours after birth either routinely or if they have not yet passed meconium. Administration of an acetylcysteine retention enema is recommended for foals with refractory cases of meconium impaction.     

Protocol: An improved high-throughput method for generating tissue samples in 96-well format for plant genotyping (Ice-Cap 2.0)

Background  

We previously developed a high-throughput system called 'Ice-Cap' for growing Arabidopsis seedlings in a 96-well format and rapidly collecting tissue for subsequent DNA extraction and genotyping. While the originally described Ice-Cap method is an effective tool for high-throughput genotyping, one shortcoming of the first version of Ice-Cap is that optimal seedling growth is highly dependent on specific environmental conditions. Here we describe several technical improvements to the Ice-Cap method that make it much more robust and provide a detailed protocol for implementing the method.     

Experimental investigation of the mechanical properties and natural frequencies of simply supported Sitka spruce plates

Wood Science and Technology - Wood remains the material of choice for stringed musical instruments. However, as supplies of suitable wood decrease, a need to maximize the use of available timber...     

Production of dinitrogen and nitrous oxide in soil suspensions as affected by redox potential

The effect of soil redox potential on N₂O and N₂ emission from soil suspensions was studied under laboratory conditions. Crowley silt loam soil suspensions were equilibrated under controlled (?200, ?100, 0, +100, +200, +300, and +400 mV) redox levels, and the amounts of N₂ and N₂O evolved quantified. At higher redox levels (+300, and +400 mV) nitrification was the dominant soil biological process controlling N chemistry. A small amount of N₂O evolved during nitrification. A redox value between +300 and +200 mV was found critical for denitrification to occur. Both N₂ and N₂O were produced during denitrification. The maximum amount of N₂O evolved at a redox value of 0 mV. Dinitrogen emission increased at lower redox levels. The highest N₂/N₂O evolution ratio was observed at ?200 mV and the ratio decreased with increasing redox. A lack of N-balance during denitrification at redox levels of +100, and +200 mV is also reported.     

Perennial growth and salinity tolerance in wheat × wheatgrass amphiploids varying in the ratio of wheat to wheatgrass genomes

Since wheat and other annual cereal crops are often harvested for forage instead of grain in California, replacing them with perennial crops could save energy and reduce the release of heat-trapping gases. To assess the potential for perennial crops based on wheat, biomass yield and stand persistence were studied for nine wheat×wheatgrass amphiploids (8x to 14x) and five wheatgrass species (2x to 10x) over three seasons in the Central Valley, California. The 8x and 10x amphiploids died after one biomass harvest and a single summer period. In contrast, the 14x amphiploids, which were sterile, continued producing biomass over the entire period of the trial. They were also highly salt-stress tolerant with little decline in biomass production in response to an increase in salinity from 100 and 250 mM NaCl in a solution-culture study. The development of a salt-stress-tolerant perennial crop based on wheat for the California-type climate will require either a substantial improvement in perennial growth of low-ploidy (8x) amphiploids or the development of technology for efficient vegetative propagation of the sterile high-ploidy (14x) amphiploids.     

Should all degraded landscapes be restored? a look at the appalachian copper basin

Rehabilitation of degraded landscapes is generally regarded as the most appropriate objective. Occasionally, however, other aspects of the situation need to be considered and may lead to a different decision. This paper presents the case of the Appalachian Copper Basin, located mainly in south-eastern Tennessee, USA, which was degraded years ago as a result of copper mining and smelting. A brief history of the site is given, along with a review of some rehabilitative efforts. Discussion then turns to the way visitors and residents perceive this landscape, the impact these two viewpoints have had over the years, and how they have (or have not) changed. Landscape values are also examined, the interpretation of which largely determines a person's opinion toward rehabilitation. The point is made that some degraded landscapes can have value as degraded landscapes, in this instance now primarily historical and cultural. The current situation in the Copper Basin is summarized and an alternative course of action suggested. It is concluded that rehabilitation is not always the only, or even the most important, goal and that degraded landscapes of long standing sometimes require special consideration.     

Noncovalent cross-linking of casein by epigallocatechin gallate characterized by single molecule force microscopy

Interaction of the tea polyphenol epigallocatechin gallate (EGCG) with beta-casein in milk affects the taste of tea and also affects the stability of the tea and the antioxidant ability of the EGCG. In addition, interaction of polyphenols with the chemically similar salivary proline-rich proteins is largely responsible for the astringency of tea and red wine. With the use of single molecule force microscopy, we demonstrate that the interaction of EGCG with a single casein molecule is multivalent and leads to reduction in the persistence length of casein as calculated using the wormlike chain model and a reduction in its radius of gyration. The extra force required to stretch casein in the presence of EGCG is largely entropic, suggesting that multivalent hydrophobic interactions cause a compaction of the casein micelle.