2,575 research outputs found

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

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    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

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    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

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    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

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    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

    TransformasĂ­e soos deur vuur

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    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

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    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

    Wetenskaplike beoefening van die teologie aan die teologiese skool.

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    Hierdie artikel kan, weens verskillende oorsake wat hier nie genoem hoef te word nie, slegs ’n vlugtige terugblik in die verlede wees, om dan na te speur wat die moontlikhede vir die toekoms is

    * ’n Toekomsblik.

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    ’n Gebrek aan bekwame bestuurders word werklik in Suid-Afrika ondervind. Nuwe fabrieke en besigheidsinrigtings het geen ander uitweg as om bestuurders van gevestigde sake te lok nie, om hulle dienste dan weer te verloor aan ander wat beter vooruitsigte aanbied. Dieselfde geld natuurlik vir deskundiges op tegniese gebied en in die ingenieurswese
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