An investigation of the veld problems of the Molopo area: I. early findings

Factors mainly responsible for limiting animal production in the Molopo ranching area are the poor grass species composition of the veld, bush encroachment, droughts and the poor fertility status of the soil. Data illustrating the extent to which grass species composition and grass production are affected by these factors are presented and discussed. Data from earlier attempts to .solve these problems reveal that several different directions of pasture research have possibilities in such semi‐arid areas.     

Evaluation of Carolina Rinse solution as a treatment for ischaemia reperfusion of the equine jejunum

REASONS FOR PERFORMING STUDY: Ileus and peritoneal adhesions are the most common complications following surgery for small intestinal obstruction. Carolina Rinse (CR) has been shown to decrease reperfusion injury in intestine and other organs. HYPOTHESIS: CR decreases intestinal inflammation and subsequent scarring associated with reperfusion injury. METHODS: CR was infused intra-arterially and applied topically just prior to reperfusion in jejunum exposed to experimental ischemia. Vascular permeability, neutrophil accumulation and serosal scarring were compared in treated and untreated intestine. RESULTS: CR maintained a normal osmotic reflection coefficient and decreased migration of neutrophils into the serosa during reperfusion. After 10 days, treated intestine was normal in appearance with a trend toward less serosal scarring and fibroblast proliferation. There was a significant decrease in fibroplasia at biopsy sites in treated intestine. CONCLUSIONS: Arterial perfusion combined with topical application of CR during jejunal ischaemia decreases immediate reperfusion injury and limits post operative scarring. POTENTIAL RELEVANCE: CR should be used as a local perfusate rather than a systemic treatment; it may best be applied topically and intraluminally to avoid damaging mesenteric arteries. CR should be considered an adjunct treatment as part of overall surgical management and post operative care.     

Seasonal changes in lignin distribution during tracheid development in Pinus radiata D. Don

Summary Lignin distribution in developing tracheids of Pinus radiata was studied throughout the growth' season using quantitative interference microscopy. The pattern of lignification remained constant although the number of lignifying cells varied reaching a maximum in summer. Lignification of the secondary wall of latewood tracheids was incomplete at the onset of winter. Each stage of lignification was preceded by deposition of carbohydrates with lignification of the middle lamella starting after S1 formation and lignification of the secondary wall starting after S3 formation. Lignification of the middle lamella was completed before the start of lignin deposition in the secondary wall. In one of the trees examined, the secondary wall lignified concurrently with the middle lamella and this was associated with a low lignin concentration in the middle lamella of mature cells. The secondary wall reached a mature lignin concentration of 21–22% v/v except in one specimen containing severe compression wood which reached 28% v/v. The cell corner middle lamella reached a mature lignin concentration of 74–87% v/v.