Four cases of chondrodystrophy in fallow deer.

The gross and microscopic pathology in four cases of chondrodystrophy in a herd of captive fallow deer is described. The gross pathology was similar in all cases with shortening of all the bones, especially of the limbs, but at the microscopic level two distinct types of abnormality were present in the epiphyseal plates. In one type there was failure of proliferation of chondrocytes and in the other proliferation and vascularisation were irregular.     

Nonrandom processes maintain diversity in tropical forests

An ecological community's species diversity tends to erode through time as a result of stochastic extinction, competitive exclusion, and unstable host-enemy dynamics. This erosion of diversity can be prevented over the short term if recruits are highly diverse as a result of preferential recruitment of rare species or, alternatively, if rare species survive preferentially, which increases diversity as the ages of the individuals increase. Here, we present census data from seven New and Old World tropical forest dynamics plots that all show the latter pattern. Within local areas, the trees that survived were as a group more diverse than those that were recruited or those that died. The larger (and therefore on average older) survivors were more diverse within local areas than the smaller survivors. When species were rare in a local area, they had a higher survival rate than when they were common, resulting in enrichment for rare species and increasing diversity with age and size class in these complex ecosystems.     

The effect of microbial activity on soil water diffusivity

In this study, we explored the effects of microbial activity on the evaporation of water from cores of a sandy soil under laboratory conditions. We applied treatments to stimulate microbial activity by adding different amounts of synthetic analogue root exudates. For comparison, we used soil samples without synthetic root exudates as control and samples treated with mercuric chloride to suppress microbial activity. Our results suggest that increasing microbial activity reduces the rate of evaporation from soil. Estimated diffusivities in soil with the largest amounts of added root exudates were one third of those estimated in samples where microbial activity was suppressed by adding mercuric chloride. We discuss the effect of our results with respect to water uptake by roots.

Highlights

• We explored effects of microbial activity on the evaporation of water from cores of a sandy soil.
• We found the effect of microbial activity on water release characteristic was small.
• Increasing microbial activity reduced evaporation from soil, while microbial suppression increased it.
• Effect of microbial activity on root water uptake was estimated to be equivalent to a change in soil structure.

     

Characterization of Transgenic Pigs That Express Human Decay Accelerating Factor and Cell Membrane‐tethered Human Tissue Factor Pathway Inhibitor

The expression of human complement regulatory proteins (hCRP; hDAF, hCD59, and hMCP) in pig tissues has been suggested as one of strategies to overcome the hyperacute rejection (HAR) in pig‐to‐human transplantation. Expression of human tissue factor pathway inhibitor (hTFPI) in porcine endothelial cells has been suggested as a remedy to overcome microvascular thrombosis. To investigate the effects of these combined transgenes, we established transformed pig cells expressing human decay accelerating factor (hDAF) under the control of enhancer promoter (5′LTR‐PCMVIE), and the fusion protein (hTFPI/hCD4) consisting of the functional domains (K1 and K2) of hTFPI and membrane‐tethering domains (D3 and D4) of hCD4 under the control of PCMVIE. Transgenic pigs were generated with the transformed porcine cells through somatic cell nuclear transfer (SCNT) technology. Analysis of quantitative PCR and real‐time quantitative RT‐PCR showed that four copies of hDAF were integrated and 391 copies of hDAF mRNA expressed in the cells of the transgenic pig. The enhancing activity of 5′LTR was approximately 2 fold compared to CMVIE promoter only. The cell viability test showed that more than 80% of ear cells were viable in the presence of 50% human serum. The chromogenic substrate assay and immunocytochemical staining with tail cells showed that the TFPI activity of fusion protein was observed on the cell membrane. The membrane localization of hDAF and hTFPI proteins was observed by immunocytochemical staining, and the expression of transgenes in heart and liver tissues was also confirmed by immunohistochemistry.     

Vertical migratory behavior of the infective third-stage larvae of Oesophagostomum dentatum

The vertical migratory behavior of third-stage infective larvae (L3i) of Oesophagostomum dentatum was investigated using upright truncated agarose cones and equivalent conical depressions in agarose. Geotactic response varied with the age of the infective larvae. Four-day-old L3i showed no preference for the sloping surfaces of either indented or upright cones, while the 8-day-old L3i showed a positive geotactic reaction, migrating down the sloping surface of the depressions.     

Regional Histological Variations of the Nasal Mucosa of Cattle

Aspects of the histology of the nasal mucosa of calves from four to six months of age have been described.

The functional significance of the type of epithelium, its thickness, the degree of neutrophil invasion, and its relationship to the numbers of Pasteurella haemolytica in the nasal cavity have been discussed. In addition, the arrangement and depth of glands in the lamina propria and the presence of lymph follicles have been described.

     

Induction of circulating interferon in calves with three different types of double stranded ribonucleic acid

Three double-stranded ribonucleic acids (dsRNA), given intravenously, were evaluated for interferon induction in calves. Groups of four calves were given an initial injection then, 24 h later, a second injection of each dsRNA material. The synthetic dsRNA, poly I.poly C, at 0.5 mg/kg stimulated serum interferon in two calves after an initial injection and in three calves after a second dose, whereas a natural dsRNA (BRL 5907) at 0.5 mg/kg induced interferon in only one calf after both injections. A polyquaternary ammonium complex (BRL 10739) of natural dsRNA, at 0.1 mg/kg, induced interferon in all four calves after a single injection and circulating interferon persisted longer than with the other two dsRNA materials.