The Effect of Micro-oxygenation on the Phenolic Composition, Quality and Aerobic Wine-Spoilage Microorganisms of Different South African Red Wines

The effect of micro-oxygenation treatments on the composition of different South African red wines was evaluated.  In some wines, micro-oxygenation led to an increase in colour density, with a corresponding change in colour, due to the formation of polymeric pigments. This increase also led to the red colour becoming more resistant to the bleaching effect of SO2. Micro-oxygenation also seemed to be more effective in increasing the colour densities of younger red wines than the older ones, although total red pigments were found to be highest in an older red wine that had received micro-oxygenation. Differences in the gelatine index were also observed over time. The micro-oxygenated and barrel-matured wines also had lower concentrations of catechin and the procyanidin B1, and showed a corresponding increase in polymeric pigment and polymeric phenols. Micro-oxygenation led to higher acetic acid bacteria counts, although no increase in volatile acidity was observed in these wines. A tasting panel preferredyounger red wines that had undergone micro-oxygenation. In an older red wine prolonged micro-oxygenation led to the wine becoming over-aged, with an increase in the barnyard/medicinal character, which corresponded with an increase in Brettanomyces counts. Micro-oxygenation can be used to increase the quality of young red wines, but further research is needed in this area

Oxygen in Must and Wine: A review

Oxygen can play an important role during the winemaking process. It can influence the composition and quality of the must and wine. Phenolic compounds are the main substrates for oxidation in must and wine. Oxygen addition leads to colour changes and the polymerisation of phenolic molecules in wine. Oxygen can, however, also influence the flavour and microbial composition of wine drastically, with certain off-flavours being formed and spoilage micro-organisms able to grow at too high oxygen additions to wine. A state-of-the-art, up-to-date review on the effects of oxygen in must and wine has, however, not been published recently. This review focuses on the effects of oxygen in must, during alcoholic fermentation, extended lees contact and during ageing of white and red wines. The effects it has on acetic acid bacteria and Brettanomyces are also discussed, as well as micro-oxygenation, a relative new technique used in wine production

The incomplete cone in carcinoma in situ of the cervix : a prospective study in a developing country

The original publication is available at http://www.samj.org.zaThe diagnostic procedures and treatment of carcinoma in situ and severe dysplasia of the cervix are becoming more conservative. In a developing country special problems make such an approach more hazardous. During a 15-months period the diagnosis in 25 of 206 patients (12,1%) with a smear positive for carcinoma in situ could not be confirmed histologically at Tygerberg Hospital. A prospective study of 147 cases (71,4%) in which the diagnosis was confirmed revealed that they were mostly young patients of relatively high gravidity. The difficulty of assessing the completeness of a cervical cone and of evaluating a postconization smear is confirmed. The danger of a too conservative approach in our patients is confirmed by the fact that only 8,2% of patients came for regular follow-up examinations and that 34,7% did not return for follow-up smears. The high incidence of total hysterectomy (51,7%) as the definitive form of treatment is defended, and a more conservative future approach of confirming the diagnosis and reducing the incidence of cervical conization is suggested.Publishers' versio

Working Within Constraints: Managing African Savannas for Animal Production and Biodiversity

The mean density of livestock biomass on African rangelands now greatly exceeds that of indigenous large herbivores, although livestock cannot fully substitute for wildlife with respect to co-evolved ecosystem processes involving herbivory. The dominance of livestock in semi-arid rangelands is largely due to water provision, which uncouples livestock population dynamics from the rainfall-driven trajectories followed by indigenous ungulate species in wildlife areas. Ecological sustainability cannot be achieved with a few exotic species maintained at unprecedented biomass densities in savanna ecosystems, which are evolutionarily adapted for species-rich communities of ungulates of a wise range of sizes. Integrating wildlife and livestock in multi-species animal production systems offers a partial solution. Community-based ecotourism can effectively augment pastoralism in semi-arid rangelands but, as rainfall increases, the opportunity costs become too high. Direct payment approaches show promise for offsetting opportunity costs, although major obstacles remain in the form of political corruption and obstructive practices by national governments

Transformasíe soos deur vuur

In sy boek Sons of Adam stel dr. S. M. Zwemer in hoofstuk 5 Moses en Simson naas en teenoor mekaar

Ontwikkelingsvooruitsigte in die Oos-Transvaalse Laeveld

Hierdie landstreek is ongetwyfeld die deel van ons land waar in die naaste toekoms die grootste ontwikkeling gaan plaasvind, nie alleen op landbougebied nie, maar ook op minerale-en nywerheidsgebied

Los gedagtes oor die plek van landbou in ons volkshuishouding.

Die bepaling van die plek van landbou in enige volkshuishouding kan van meer as een aspek benader word

„In die jaar 2000.”

Die mens is gewoonlik bevrees vir wat die more te voorskyn mag bring.Die geskiedenis laat hom nie toe om van sy erfenis weg te vlug nie. Terselfdertyd is dit die geskiedenis wat die mens in staat stel om met ’n enigsinsvoorbedagte beplanning op te tree. Alle lewe is ’n proses en alle prosesseis van nature iets dinamies. Dit is tevergeefs om daarna te strewe, metenige hoop van sukses, om ’n oomblik van die verlede te herwin. Suksesis nooit finaal nie. As die mens ’n beter muisval bou, sal die natuur mettertyd’n skelmer muis baar

Neutronefisika as navorsingsgebied*

Alhoewel die Kernfisika in die populêre opvatting beskou word as ’n moderne ontwikkeling, gaan die geskiedenis daarvan reeds relatief ver terug in die verlede van die Fisika. Rutherford het reeds in 1911 die atoomkern ontdek, en in 1913 het J. J. Thompson die massas van kerne begin bepaal