The extent of urban densification in Stellenbosch

Thesis (MA)--Stellenbosch University, 2017.ENGLISH ABSTRACT: There is a perpetual burden to supply accommodation to increasing population numbers in Stellenbosch. The most ideal way in which the property market is able to cater for this demand is through the development of high-density accommodation (Donaldson & Morkel 2012). Densification is a national spatial strategy aimed at integrating cities socially and spatially (Stellenbosch Municipality 2012a). However, there is a notion that densification in Stellenbosch is implemented in an ad hoc manner due to the lack of adequate policies regulating development in the town (Donaldson & Morkel 2012). What the impact may be on urban space is not known yet. Thus, it was regarded as valuable to determine the extent of urban densification in order to minimise undesired spatial consequences for future generations. Through quantitative data, the study aimed to determine where, to what extent and why densification took place in a selected area of Stellenbosch from 2000 to 2016. The study objectives were to identify properties on which densification had taken place, to identify the most prominent methods implemented towards densification, to map the changes in residential density, to identify existing policy documents and to make recommendations for the densification and future growth of the town. The study primarily focused on changes in residential densities, e.g. where there was a single dwelling unit in the past there now are multiple dwelling units on the same plot. Commercial and industrial units were excluded from the study. Sites that were under construction were included based on the planned number of units. The study entails a literature review and the compilation of quantitative data from Stellenbosch Municipality. The extent of densification was calculated by dividing the number of dwelling units by the hectares of land (du/ha = density). Based on the findings, the study concludes that densification has been a prominent feature in all the zones under study since 2000, excluding Zones 16 and 30. Due to several factors, the zones in the study area provide an obvious choice for densification in Stellenbosch. These factors relate to proximity and need for convenience, the existing infrastructure, housing demand and supply, as well as the availability of land and subsequent development opportunities. The results indicate that, although there are areas where no consolidation occurred, the consolidation of properties remains the most prominent method of densification since 2000. This is followed by the construction of additional dwelling units and the construction of multiple attached dwelling units. The study suggests that, although spatial planning policies exist in Stellenbosch, they may not be adequate and/or sufficiently enforced. The study recommends that the Municipality should identify suitable locations for densification and identify Council-owned land that is available for the development or redevelopment of new and existing buildings. Available land should be re-zoned, where necessary, in line with specifically drafted planning strategies for a given area. Incentives should be used as a tool to encourage developers to develop land if it meets the developmental guidelines determined by the context-specific planning strategies. Guidelines should ideally incorporate the holistic principles of densification, such as socio-economic integration, mixed use, sustainable transport, appropriate densities, sense of community, environmental consciousness and functional viability.AFRIKAANSE OPSOMMING: Stellenbosch staar ’n voortdurende uitdaging in die gesig om verblyf aan die groeiende aantal inwoners te verskaf (Donaldson & Morkel 2012). Die beste manier om hierdie vraag na verblyf aan te spreek is deur die oprig van hoëdigtheid verblyf. Verdigting is ’n nasionale ruimtelike strategie wat beoog om stede ruimtelik en sosiaal te integreer (Stellenbosch Municipality 2012a). Daar word egter beweer dat verdigting in Stellenbosch op ’n ad hoc manier geïmplementeer word as gevolg van ’n tekort aan toepaslike riglyne om ontwikkeling in die dorp te reguleer (Donaldson & Morkel 2012). Wat die impak op die stedelike ruimte sal wees, is tans onbekend. Dit is dus waardevol om die mate van stedelike verdigting te bepaal om ongewensde ruimtelike gevolge vir die nageslag te minimaliseer. Deur kwantitatiewe data beoog die studie om te ontleed waar, tot watter mate en hoekom verdigting plaasgevind het in die area wat afgebaken word deur Merrimanlaan, die R44, die R310 en Simonsbergweg vanaf die jaar 2000 tot 2016. Die doel van die studie was om erwe te identifiseer waar verdigting plaasgevind het, om te identifiseer watter metodes geïmplementeer is om verdigting te bereik, om die verandering in verdigting te karteer, om bestaande beleidsdokumente met betrekking tot verdigting te identifiseer en terselfdertyd voorstelle te maak vir die verdigting en toekomstige groei van die dorp. Die studie fokus primêr op die verandering van residensiële verdigting, bv. waar daar ’n enkele woonhuis in die verlede was, is daar nou veelvuldige wooneenhede op dieselfde erf. Industriële en kommersiële eenhede word dus nie in berekening geneem nie. Die studie behels ’n literatuuroorsig, sowel as ’n samestelling van kwantitatiewe data wat deur die Munisipaliteit van Stellenbosch beskikbaar gestel is. Die mate van verdigting is bereken deur die hoeveelheid wooneenhede te deel deur die hektaar land waarop die eenhede gebou is (du/ha = verdigting). Die bevindinge van die studie bewys dat verdigting ’n prominente rol gespeel het met betrekking tot al die sones in die studiegebied sedert die jaar 2000, met die uitsondering van Sones 16 en 30. As gevolg van verskeie faktore is die sones in die studiegebied ’n logiese keuse vir verdigting in Stellenbosch. Hierdie faktore sluit in nabyheid en die behoefte aan gemak, die bestaande infrastruktuur, die vraag en aanbod van behuising, asook die beskikbaarheid van grond en gevolglike ontwikkelingsgeleenthede. Die resultate dui voorts aan dat, alhoewel konsolidasie nie in al die gebiede plaasgevind het nie, konsolidasie steeds die prominentste metode van verdigting sedert 2000 was. Die tweede prominentste metode was die konstruksie van addisionele wooneenhede, gevolg deur die konstruksie van veelvuldige gekoppelde wooneenhede. Die studie stel voor dat, alhoewel ruimtelike beplanningsbeleide vir Stellenbosch bestaan, dit nie altyd volledig is of ten volle afgedwing word nie. Die studie beveel aan dat die Munisipaliteit toepaslike grond vir verdigting identifiseer en dat enige Raadsgrond vir ontwikkeling en herontwikkeling van nuwe en bestaande geboue geïdentifiseer en beskikbaar gestel word. Waar moontlik moet beskikbare grond in lyn met die opgestelde beplanningstrategieë van toepassing op ‘n spesifieke area hersoneer word. Aansporings kan gebruik word as ’n instrument om ontwikkelaars aan te moedig om grond binne die ontwikkelingsriglyne te ontwikkel, soos voorgeskryf deur konteks-spesifieke beplanningstrategieë. Riglyne moet die holistiese beginsels van verdigting soos sosio-ekonomiese integrasie, gemengde gebruik, omgewingsbewustheid, volhoubare vervoer, toepaslike digtheid, gemeenskapsgevoel en funksionele uitvoerbaarheid in aanmerking neem

Physiological demands of rugby union matches and practice sessions

Research studies indicate that, by determining the physiological load placed on athletes during competitions, it can aid in the development of strength and conditioning programmes, according to the specific demands placed on athletes. Physiological data, specifically on rugby union players, are limited, thus stressing the need for more information in this area. The aim of the study was to investigate the physiological demands of South African male U/21 club rugby players and to establish the relationship between physiological demands experienced during rugby games and practice sessions. Scientific methods to describe physiological demands in sport that are used are heart-rate and blood-lactate measurements. A group of U/21 rugby players (n=15) of the University of Pretoria (Tuks) rugby club participated in this study. Variables that were tested included blood-lactate concentrations and mean heart-rates during a rugby match and practice sessions. The Tuks U/21 team’s data were analysed by means of descriptive statistics (means and standard deviations). Significant differences between rugby match and practice sessions were determined by a dependent t-test (p<0.05). An independent t-test was used to determine significant differences between the forwards and backs group. The results showed statistically significant differences between mean heart-rate in the rugby match (154.40 ±13.53) and practice sessions (138.33±4.81). No significant differences were found between peak lactate measurements in the match (5.39 ±2.44) and practice sessions (4.93±1.83). Between the forwards and backs group no statistical significance could be found for average heart-rate and blood-lactate levels in practice sessions and during the match. The findings of the present study indicate that rugby union matches for club level U/21 players are an intermittent type of activity, which utilise both aerobic and anaerobic energy systems.http://www.ajol.info/journal_index.php?jid=153&ab=ajpher

Birth weight and body composition as determined isotopic dilution with deuterium oxide in 6- to 8-year-old South African children

Low and high birth weight (BW) are associated with obesity later in life; however, this association has not been extensively studied in African countries. This study determines the association between BW and body composition derived from deuterium oxide (D2O) dilution in 6- to 8-year-old South African children (n = 91; 40 boys, 51 girls). BW was recorded retrospectively from the children’s Road-to-Health cards. Weight and height were measured using standard procedures, and D2O dilution was used to determine total body water and, subsequently, to determine body fat. Fatness was classified using the McCarthy centiles, set at 2nd, 85th, and 95th (underfat, overfat and obese). BW correlated with body composition measures, such as body weight (r = 0.23, p = 0.03), height (r = 0.33, p < 0.001), and fat free mass (FFM; r = 0.27, p = 0.01). When multiple regression analysis was employed, BW significantly and positively associated with FFM (β = 0.24, p = 0.013; 95% CI: 0.032; 0.441) and fat mass (β = 0.21, p = 0.02, 95%CI: 0.001; 0.412) in girls and boys combined. A total of 13% of the children had a low BW, with 21% being overweight and 17% obese. More girls than boys were overweight and obese. Intervention strategies that promote healthy uterine growth for optimal BW are needed in order to curb the global obesity pandemic

Urinary peptidomics and pulse wave velocity: The African-PREDICT study

Increased arterial stiffness is related to early vascular aging and is an independent predictor for cardiovascular disease and mortality. Molecular mechanisms underlying increased arterial stiffness are largely unexplored, especially at the proteome level. We aimed to explore the relationship between pulse wave velocity and urinary proteomics. We included 919 apparently healthy (no chronic illnesses) Black and White men and women (equally distributed) between 20 and 30 years from the African-PREDICT study. Capillary electrophoresis time-of-flight mass spectrometry was used to analyze the urinary proteome. We measured the carotid-femoral pulse wave velocity to estimate arterial stiffness. In the total group, pulse wave velocity correlated positively with collagen-derived peptides including collagen types I, II, III, IV, V, and IX and inversely with collagen type XI (adjusted for mean arterial pressure). Regarding noncollagen-derived peptides, pulse wave velocity positively correlated with polymeric immunoglobulin receptor peptides (n = 2) (all q-value ≤0.05). In multivariable adjusted analyses, pulse wave velocity associated positively and independently with seven urinary peptides (collagen type I, n = 5) (all p-value ≤0.05). We found significant positive and independent associations between pulse wave velocity and the collagen type I-derived peptides, suggesting that dysregulation of collagen type I in the extracellular matrix scaffold could lead to early onset of increased arterial stiffness

A urinary peptidomics approach for early stages of cardiovascular disease risk: the African-PREDICT study

Cardiovascular disease (CVD) affects individuals across the lifespan, with multiple cardiovascular (CV) risk factors increasingly present in young populations. The underlying mechanisms in early cardiovascular disease development are complex and still poorly understood. We therefore employed urinary proteomics as a novel approach to gain better insight into early CVD-related molecular pathways based on a CVD risk stratification approach. This study included 964 apparently healthy (no self-reported chronic illnesses, free from clinical symptoms of CVD) black and white men and women (aged 20–30 years old) from the African Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension (African-PREDICT) study. Cardiovascular risk factors used for stratification included obesity, physical inactivity, tobacco use, high alcohol intake, hyperglycemia, dyslipidemia and hypertension. Participants were divided into low (0 risk factors), medium (1–2 risk factors) and high (≥3 risk factors) CV risk groups. We analyzed urinary peptidomics by capillary electrophoresis time-of-flight mass spectrometry. After adjusting for ethnicity, sex and age, 65 sequenced urinary peptides were differentially expressed between the CV risk groups (all q-values ≤ 0.01). These peptides included a lower abundance of collagen type I- and III-derived peptides in the high compared to the low CV risk group. With regard to noncollagen peptides, we found a lower abundance of alpha-1-antitrypsin fragments in the high compared to the low CV risk group (all q-values ≤ 0.01). Our findings indicate lower abundances of collagen types I and III in the high compared to the low CV risk group, suggesting potential early alterations in the CV extracellular matrix

Identifying a urinary peptidomics profile for hypertension in young adults: the African-PREDICT study

Hypertension is one of the most important and complex risk factors for cardiovascular diseases (CVDs). By using urinary peptidomics analyses, we aimed to identify peptides associated with hypertension, building a framework for future research towards improved prediction and prevention of premature development of CVD. We included 78 hypertensive and 79 normotensive participants from the African-PREDICT study (aged 20–30 years), matched for sex (51% male) and ethnicity (49% black and 51% white). Urinary peptidomics data were acquired using capillary-electrophoresis-time-of-flight-mass-spectrometry. Hypertension-associated peptides were identified and combined into a support vector machine-based multidimensional classifier. When comparing the peptide data between the normotensive and hypertensive groups, 129 peptides were nominally differentially abundant (Wilcoxon p &lt; 0.05). Nonetheless, only three peptides, all derived from collagen alpha-1(III), remained significantly different after rigorous adjustments for multiple comparisons. The 37 most significant peptides (all p ≤ 0.001) served as basis for the development of a classifier, with 20 peptides being combined into a unifying score, resulting in an AUC of 0.85 in the ROC analysis (p &lt; 0.001), with 83% sensitivity at 80% specificity. Our study suggests potential value of urinary peptides in the classification of hypertension, which could enable earlier diagnosis and better understanding of the pathophysiology of hypertension and premature cardiovascular disease development

ESNOQ, Proteomic Quantification of Endogenous S-Nitrosation

S-nitrosation is a post-translational protein modification and is one of the most important mechanisms of NO signaling. Endogenous S-nitrosothiol (SNO) quantification is a challenge for detailed functional studies. Here we developed an ESNOQ (Endogenous SNO Quantification) method which combines the stable isotope labeling by amino acids in cell culture (SILAC) technique with the detergent-free biotin-switch assay and LC-MS/MS. After confirming the accuracy of quantification in this method, we obtained an endogenous S-nitrosation proteome for LPS/IFN-γ induced RAW264.7 cells. 27 S-nitrosated protein targets were confirmed and using our method we were able to obtain quantitative information on the level of S-nitrosation on each modified Cys. With this quantitative information, over 15 more S-nitrosated targets were identified than in previous studies. Based on the quantification results, we found that the S-nitrosation levels of different cysteines varied within one protein, providing direct evidence for differences in the sensitivity of cysteine residues to reactive nitrosative stress and that S-nitrosation is a site-specific modification. Gene ontology clustering shows that S-nitrosation targets in the LPS/IFN-γ induced RAW264.7 cell model were functionally enriched in protein translation and glycolysis, suggesting that S-nitrosation may function by regulating multiple pathways. The ESNOQ method described here thus provides a solution for quantification of multiple endogenous S-nitrosation events, and makes it possible to elucidate the network of relationships between endogenous S-nitrosation targets involved in different cellular processes