Browsing by Author "De Villiers, A."

Now showing 1 - 9 of 9
  • No Thumbnail Available
    Item
    Analytical techniques for wine analysis : an African perspective; a review
    (2012-02-22) De Villiers, A.; Alberts, P.; Tredoux, A. G. J.; Nieuwoudt, Helene
    Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry. © 2011 Elsevier B.V. All rights reserved.
  • Thumbnail Image
    Item
    The deer hunter : a portrait of Aeneas
    (Stellenbosch University, Department of Ancient Studies, 2013) De Villiers, A.
    The theme of hunting occurs throughout the Aeneid at strategic points to link specific events and foreshadow certain outcomes. Many scholars have noted the increasingly ominous nature of hunting in the epic: from Aeneas’s first hunt in book one to provide food for his people, through Ascanius’s trophy hunt that sparks the war in Italy, to Aeneas’s final vengeful hunting of Turnus. But as far as the protagonist Aeneas is concerned it is specifically through acts of deer hunting that an increasing lack of feeling in his character comes to light. In this paper I will argue that, through recurring instances of deer hunting, both literal and symbolic, a gradual desensitization of Aeneas is revealed. This prepares the reader for his final act in the epic: his killing of Turnus in book twelve, an unnecessary act that strips him of the qualities of pietas so abundantly attributed to him throughout the work.
  • Thumbnail Image
    Item
    The development, implementation and evaluation of a short course in objective structured clinical examination (OSCE) skills
    (Medical & Pharmaceutical Publications (Pty) Ltd -- MedPharm Publications, 2012-02) De Villiers, A.; Archer, E.
    Background: Objective structured clinical examination (OSCE) examiner training is widely employed to address some of the reliability and validity issues that accompany the use of this assessment tool. An OSCE skills course was developed and implemented at the Stellenbosch Faculty of Health Sciences and its influence on participants (clinicians) evaluated. Method: Participants attended the OSCE skills course, which included theoretical sessions concerning topics such as standard setting, examiner influence and assessment instruments, as well as two staged OSCEs, one at the beginning and the other at the end of the course. During the latter, each participant examined a student role-player performing a technical skill while being video recorded. Participants’ behaviour and assessment results from the two OSCEs were evaluated, as well as the feedback from participants regarding the course and group interviews with student role players. Results: There was a significant improvement in inter-rater reliability as well as a slight decrease in inappropriate examiner behaviour, such as teaching and prompting during assessment of students. Furthermore, overall feedback from participants and perceptions of student role players was positive. Conclusions: In this study, examiner conduct and inter-rater reliability was positively influenced by the following interventions: examiner briefing, involvement of examiners in constructing assessment instruments, as well as examiners viewing (on DVD) and reflecting on their assessment behaviour. This study proposes that the development and implementation of an OSCE skills course is a worthwhile endeavour in improving validity and reliability of the OSCE as an assessment tool.
  • Thumbnail Image
    Item
    The impact of different tannin to anthocyanin ratios and of oxygen on the phenolic polymerisation over time in a wine-like solution
    (South African Society for Enology and Viticulture, 2019) Garrido-Banuelos, G.; Buica, A. S.; Sharp, E.; De Villiers, A.; Du Toit, W. J.
    Colour and phenolic stability during ageing are influenced by the levels of distinct classes of phenolics in young red wines. The ratios between different classes of phenolic compounds also determine the colour and phenolic development of red wines. The present study evaluated the impact of forced oxidation on different anthocyanin/tannin (A/T) extracts and its consequent effect on the colour and phenolic evolution over time. The results showed that higher contents of seed tannins could enhance phenolic polymer formation, especially in the presence of oxygen. The addition of oxygen seemed to favour certain polymerisation reactions between tannins, leading to higher concentrations of monomeric anthocyanins in solution. A slower oxygen consumption was also observed as the phenolic composition of the wine-like extract evolved over time.
  • Thumbnail Image
    Item
    Impact of time, oxygen and different anthocyanin to tannin ratios on the precipitate and extract composition using liquid chromatography-high resolution mass spectrometry
    (South African Society for Enology and Viticulture, 2019) Garrido-Banuelos, G.; Buica, A.; De Villiers, A.; Du Toit, W. J.
    Wine colour and phenolic stability over time are influenced by the amount and nature of phenolics in young wines. The ratio between different phenolic compounds can also be determinant in the colour and phenolic development of red wines. Three different anthocyanin to tannin ratios extracted in a wine-like system were saturated with oxygen several times during sample storage. A LC-HRMS method was used to evaluate the impact of a forced oxidation and of the different extracts on the wine-like composition and on the precipitate formed over time. The extract composition was found to be the most determinant factor for the precipitate formed. Time was also found to be a relevant factor according to the precipitate composition.
  • No Thumbnail Available
    Item
  • Thumbnail Image
    Item
    The Laodamia simile in Catullus 68 : reflections on love and loss
    (Stellenbosch University, Department of Ancient Studies, 2008) De Villiers, A.
    In Catullus’ poem 68 he compares his beloved, generally identified as Lesbia, to the mythological figure of Laodamia in a long simile covering 57 lines. Laodamia epitomises the ideal wife, both passionate and loyal and so much in love with her new husband Protesilaus, that she cannot bear to live without him. Therefore she appears to be the perfect comparison for a beloved woman as seen through the eyes of her infatuated lover. But at a closer reading of the poem the interpretation of the simile turns out to be much more complex than that. Lesbia is not loyal and she is not Catullus’ wife. He admits both these facts near the end of the poem. Furthermore, Laodamia turns out to have two referents: Lesbia and the poet himself. In this paper I will be looking at various interpretations of the Laodamia simile as well as adding my own thoughts on this complex and beautiful poem.
  • Thumbnail Image
    Item
    Results of phase I of the in vitro fertilization and embryo transfer programme at Tygerberg Hospital
    (Health and Medical Publishing Group (HMPG), 1985-05) Kruger, T. F.; Van Schouwenburg, J. A. M. H.; Stander, F. S. H.; Van den Heever, A. D.; Van Zyl, J. A.; Menkveld, R.; Kopper, K.; De Villiers, A.; Conradie, E.; Odendaal, H. J.; De Villiers, J. N.
    Phase I (3 June - 31 October 1983) of the in vitro fertilization (IVF) programme at Tygerberg Hospital is outlined in this article. This programme led to the birth of the first IVF baby in South Africa after fertilization and embryo transfer (ET) took place at this institution. The baby was born on 29 April 1984; a second baby was born on 20 June 1984. During phase I 24 laparoscopies were performed; 32 oocytes were obtained from 56 follicles, of which 62.5% were fertilized. Eleven ETs were performed, which led to 3 pregnancies. An ongoing pregnancy rate of 18% per ET and a pregnancy rate of 12,5% per laparoscopy were achieved.
  • Thumbnail Image
    Item
    Teaching first aid in high schools : the impact on students in the health sciences extended degree programme
    (UNISA Press, 2015) Louw, A.; De Villiers, A.
    Previously, first-year medical and physiotherapy students participating in the extended degree programme (EDP) at Stellenbosch University, South Africa, spent eight weeks shadowing interns at a tertiary hospital during a clinical module. In 2011, student numbers had doubled from the previous year making it impossible to accommodate the entire group in the clinical setting. Consequently, the group was divided into two, allowing one group to participate in a service-learning project (SLP), while the other group spent four weeks in the clinical setting as before. The two groups switched after four weeks. A qualitative approach was used to determine students' perceptions of the SLP. Data was obtained from structured reflective reports about students' experiences of the one-week period during which they taught First Aid to high school learners. Open-ended, written response questionnaires completed by students at the end of the four-week SLP generated further useful data regarding the logistics and administration of the project as a whole. Similar to findings reported in international studies, analysis of qualitative data indicated an increase in student motivation in terms of their studies and vocation; an enhanced sense of civic responsibility and social justice; improved group interaction and personal communication skills; as well as increased compassion and decreased racism. Besides gaining First Aid knowledge and skills, students became increasingly aware of the population they would be serving once they graduated and of their role as professionals within this community. Thus, a service-learning teaching strategy may contribute towards producing service-driven and culturally competent physicians and community leaders.