A public interface for the infrastructure of Hartbeespoort Dam Water sustains all living things on this earth and has a huge impact on the natural environment. Water is the most valuable natural resource on this earth. It is vital to humans' existence. It is why we have evolved to the point that we are now and if we do not appreciate it, it will be our demise. Water has the ability to adapt and change as different natural systems interact with it, it allows a constant balance to remain. Humans have broken the delicate balance of water supply and demand, detrimentally affecting the natural systems that support us. Since the start of the industrial era our cities have grown at an exponential rate. The development of cities has impacted negatively on natural systems. This has led to a concomitant disconnection between man and nature and has divorced humans from an understanding of the role and importance of natural water systems. . We have forgotten the positive effects that we experience when directly engaging with water as we live in environments often far from nature; rarely experiencing it fully. Our physical control of natural resources has led to a physical disconnection and under appreciation of these precious resources. This project aims to reconnect man and nature to create a new paradigm where humans value our natural resources and, in particular, water. A re-appropriation of water infrastructure through an architectural interface that fulfils cultural, social and economic functions to create a positive recreational space that celebrates water and its importance in our h eritage. T he intention is to c reate a p roductive infrastructure that facilitates exchanges between site, existing infrastructure and the user. / n Publieke skeidingsvlak vir die infrastruktuur van die Hartebeespoort Dam omgewing. Water onderhou alle lewe op aarde en het 'n groot impak op die natuurlike omgewing. Water is die belangrikste natuurlike hulpbron op die aarde en is van die uiterste belang vir die mens se voortbestaan. Dit is hoekom ons die punt bereik het waar ons nou is. Dit sal ons ondergang beteken as ons dit nie bewaar en waardeer nie. Die mens het die delikate balans van aanvraag en watervoorsiening versteur tot nadeel van die natuurlike sisteme wat ons onderhou. Sedert die begin van die industriele tydperk het ons stede eksponensie?l vergroot. Die ontwikkeling van stede het 'n negatiewe impak gehad op ons natuurlike omgewing. Dit het gelei na 'n gepaardgaande diskonneksie tussen mens en natuur en het die mens se begrip van die rol en belang van natuurlike waterbronne negatief be?nvloed. Omdat ons in omgewings woon v?r verwyder van water en dikwels van die natuur kom ons nie direk met water as lewensmiddel in ons omgewing in kontak nie. Ons fisiese beheer van natuurlike bronne het gelei tot die skeiding en onderwaardeering van hierdie kosbare bronne. Die doel van die projek is om mens en die natuur bymekaar te bring en 'n nuwe paradigma te skep waar die mens sy natuurlike bronne, en in die besonder water, waardeer. 'n Nuwe benadering tot waterinfrastruktuur deur 'n argitektonise wisselwerking wat kulturele, sosiale en ekonomiese funksies bymekaar bring om 'n positiewe onspanne ruimte te skep waar die belang van water as 'n erfenis vier, is nodig. Die doel is om 'n produktiewe infrastruktuur te skep wat uitruiling tussen die terrein, die huidige infrastruktuur en die gebruiker bymekaar bring. / Mini Dissertation (MArch (Prof))--University of Pretoria, 2016. / Architecture / MArch (Prof) / Unrestricted

Economic benefits obtained from Flagellaria guineensis, a climbing bamboo, by local people received attention in previous studies but little is known about its regeneration ecology in three different forest stand conditions, i.e. forest edges, forest gaps and mature closed-canopy stands. In the Eastern Cape of South Africa the species grows in the Transkei Coastal Forests. The main aim of this study was to assess the regeneration ecology of F. guineensis in those forests. The specific objectives were to describe the phenological state that would influence the flowering, fruiting and growth of the species, and to compare the culm (stem) development from the rhizome between the different forest stand conditions. Phenological comparison was done in forest edge and forest interior conditions two forests. Rating scales were applied to determine the phenological states of the presence and amount of flower buds, open flowers, fruits, shoots and seedlings. Development of F. guineensis was assessed by sampling clusters in the three different forest stand conditions in three forests. The observation made in two Transkei Coastal Forests indicate that F. guineensis regenerates by producing seed, new vegetative shoots from rootstocks and also shoots at the growing tips. The flowering and fruiting period occurred only in the rainy season in Mtambalala forest but both rainy and dry seasons in Bulolo forest. More flowers and fruits of F. guineensis were found in Bulolo forest and in the forest edge (where F. guineensis is able to form tangles on the canopy of its host tree) respectively. This climbing bamboo clings on any plant around it for support and forms tangles on the canopy of its host in forest edges with no direct damage caused to host trees. The production of seedlings, shoots from the rhizome and shoots at the growing tips was constant during the study period in both study sites. The growth pattern of F. guineensis was different when comparing the three Transkei Coastal Forests studied. Manubi forest was found to have clusters and culms with the highest diameters and length compared to Mtambalala and Mnenga forests. There was a significant difference in culm diameter and length of F. guineensis between all three forests, whereas cluster diameter and number of culms per cluster were not influenced by forest stand conditions. F. guineensis clusters were common in the forest edges or gaps, and formed tangles in the canopy of their host trees. The described pattern of growth of F. guineensis contributes to recovery of the forest edges or gaps by restricting easy movement in and out of the forests. Several recommendations were made for harvesting of culms for basketmaking, such as: it should be done with care to reduce tangles in the forest and tree canopies; it must take place during the dry season, when the culms in a cluster are not flowering or fruiting; and studies are needed on the growth rate of seedlings and their growth into the forest canopy and how the bamboo can be cultivated outside the forest for better production of culms. / Dissertation (MSc)--University of Pretoria, 2017. / SAFCOL / Microbiology and Plant Pathology / MSc / Unrestricted

The olfactory system is a great model to ask questions related to neuronal regeneration, axon guidance and synapse formation. Processing of smell begins in the olfactory epithelium where sensory neurons are present and the olfactory bulb is the first stop in processing odor information in the central nervous system. While the olfactory bulb has neurons that regenerate as well, we are interested in the regeneration that occurs in the olfactory epithelium after being injured because it possesses a source of neural stem cells – something unique to the rest of the body. Earlier studies have proven that the introduction of methimazole will effectively damage the olfactory sensory neurons while keeping the neural stem cells intact. By using a fate mapping technique involving Cre-ERT2 mice, we are able to track the regeneration of these sensory neurons after a methimazole induced injury. Using immunohistochemistry in combination with ImageJ software analysis, we are able to pinpoint the colocalization of markers of new olfactory sensory neurons (green fluorescent protein (GFP)) with markers of neuron maturation (olfactory marker protein (OMP)) and synapse formation (tyrosine hydroxylase (TH) and synaptophysin). Analysis of maturation was done in the olfactory epithelium by studying the colocalization of the protein OMP and GFP. Data shows that after regeneration, neurons coexpress both markers 11 days after lesion. In the olfactory bulb, we characterized the recovery of synaptic markers TH and synaptophysin after axons reached the olfactory bulb, where olfactory sensory neuron axons make synaptic contacts with dendrites of projection neurons. Overall, these data are the first one to establish a timeline for axonal regeneration and synapse formation after injury in the olfactory system.

Les sécheresses des années 1970 et 1980 ont occasionné des changements remarquables dans les paysages et écosystèmes sahéliens. Au Niger, les milieux dunaires sont les plus affectés par la dégradation des paysages aux conséquences parfois irréversibles. Cette étude tente de montrer que, malgré les modifications climatiques et les pressions anthropiques, une régénération des sols dunaires serait possible, dans cette dynamique complexe. Cela a été démontré à travers l’analyse micromorphologique des matériaux des parties superficielles des sols (0-20 cm). L’étude des caractéristiques particulières des croûtes (organisations pelliculaires de surface des sols) offre des pistes de recherches pouvant proposer des moyens et méthodes de fixation des dunes dégradées. Elle propose également des alternatives de lutte contre l’érosion éolienne et hydrique dans les écosystèmes sahéliens. Ceci cadre parfaitement avec la situation au Niger, où les phénomènes de désertification et d’ensablement des cuvettes interdunaires constituent une préoccupation majeure en matière de protection de l’environnement. / Die Dürrephasen der 1970er und 1980er Jahre haben in den Landschaften und Ökosystemen des Sahel deutliche Veränderungen verursacht. In Niger waren die Dünenlandschaften am stärksten von Degradation betroffen, teils in irreversiblem Ausmaß. Die vorliegende Studie zeigt, dass in dieser komplexen Dynamik trotz Klimaschwankungen und Nutzungsdruck die Regeneration von Böden dennoch möglich ist. Dies wurde anhand mikromorphologischer Analysen von oberflächigem Bodenmaterial (0-20 cm Tiefe) nachgewiesen. Die Untersuchung insbesondere der Eigenschaften von Oberflächenkrusten (i.S. von filmartiger Organisation der Bodenoberfläche) eröffnet Forschungsperspektiven zu Möglichkeiten und Methoden der Stabilisierung degradierter Dünen. Ebenso zeigt sie Alternativen auf im Kampf gegen äolische und durch Spülprozesse hervorgerufene Abtragung in sahelischen Ökosystemen. Damit lässt sie sich perfekt auf die Situation in Niger anwenden, wo die Phänomene der Desertifikation und der Sandeinwehung in interdunäre Wannen im Rahmen des Umweltschutzes eine wesentliche Herausforderung darstellen.

The way in which a city is spatially laid out effects the natural environment of the planet (for example: pollution and the depletion of natural resources) as well as the social environment (the community and daily life) of its residents. Through the exploration of various modern urban planning theories, I will begin to look at some different approaches to urban planning. This document favours the compact city approach which advocates higher densities, mixed use development, public transport and community living. This approach relates to initiatives currently underway in the inner city of Johannesburg. This document is about the exploration of how people live in the city and the issues surrounding housing in the urban context. The proposed architectural project is a housing scheme located in Newtown, Johannesburg. Central concepts include: urban regeneration, inner city living, visual variety in the urban realm, street edge conditions and public to private hierarchies

BACKGROUND: Cells, growth factors and scaffold are the 3 fundamental factors currently proposed necessary for tissue regeneration. The use of these components has to be orchestrated precisely for ideal functional tissue formation. Growth factors enhance cellular activities that may lead to angiogenesis, cell proliferation and extracellular matrix biosynthesis. Due to the complexity of biochemical reactions a single growth factor may have limited effect. In order to explore a mixed profile of growth factors, a new biomaterial containing multiple growth factors derived from human Amniotic Membrane was chosen to compare with a known single growth factor (rhPDGF-BB). AIM: To compare the potential for enhanced bone formation by a morselized amniotic membrane suspension (AmnioSpark) with a known single cytokine PDGF-BB (GEM21,Lynch) under ex-vivo calvaria culture conditions. MATERIALS AND METHODS: 45 Calvaria from 7-9 day neonatal CD-1 mice were surgically harvested under sterile conditions. The calvaria were split through the mid sagittal suture to create 90 test specimens. A 2mm diameter critical size defect was created by biopsy punch thru the center of each calvarial specimen. This defect was bridged with a non-crosslinked type I collagen membrane of the same diameter to act as a scaffold. To compare AmnioSpark (AGF) potential for tissue regeneration against a known single cytokine PDGF-BB, the calvarial specimen were divided into six experimental groups: 1) Defect only, 2) Defect + scaffold, 3) Defect + scaffold + a single dose of (rhPDGF-BB ) a known bone stimulant, 4) Defect + Scaffold + 4 doses (day 0,3,5,7) of ( rhPDGF-BB), 5) Defect + scaffold + a single dose of (AGF) and 6) Defect + scaffold + 4 doses (day 0,3,5,7) of (AGF). Each test group had (N=5). A unique static tissue culture method was used with DMEM medium supplemented with ascorbic acid (150 ug/ml) and bovine serum albumin (5 mg/ml) without fetal calf serum to enhance bone formation for up to 7 weeks. Culture medium was changed every 2 days after day 3 and the harvested media was used for the following analyses: A) Alkaline phosphatase (ALP) as an osteoblastic activity indicator, and B) Tartrate Resistant Acid phosphatase (TRAP) as an osteoclastic bone remodeling activity indicator1. Macro photography and Scanning electron microscope (SEM) image analysis at different magnifications was performed to evaluate surface conditions. Histological analysis was performed with light microscope images on standard 4 um sections using H&E, Tri chrome, Picrosirius red and a fluorescence stain for RUNX2 as an osteoblast marker. RESULTS: With a single dose of test material ALP activity in the AGF group was significantly higher at 5 and 7 days. In addition ALP activity was significantly higher compared to all groups for up to 3 weeks post-application in the multiple dose AGF group (P<0.05). In contrast there was a dramatic decline in ALP in all other groups within the first week. TRAP activity was not detectable in any group. SEM images showed that osteoblast like cells accumulated and new tissue formation occurred over the surface of the scaffold obliterating the defect/membrane interface at 21 days with the AGF stimulus while in the PDGF-BB group the scaffold was still distinguishable from surrounding bone with no new tissue formation or cell migration . Histologic images confirmed an organized distribution of cells along the surface of the scaffold and new bone formation around the periphery of the defect in the AGF group (FIG42), while no bone formation or cell migration occurred in PDGF-BB group (FIG 35-38). Further diagnostic stains confirmed the presence of active osteoblasts (RUNX2)and the production of collagens I and II ( Masson Tri Chrome and PSR). CONCLUSION: Our results indicate that growth factors from amniotic extract (AGF) have the potential to enhance calvarial bone regeneration under an ex-vivo culture condition. These findings suggest that AGF could be a candidate for use as a new type of therapeutic material for regenerative medicine.

Osteoporosis and low bone mass are devastating and costly diseases affecting over half the US population over 50-years old. Peak bone mass is reached around age 30 and begins to decline in the following years, leading to a multi-decade disease. While there are several treatment options, including both ant-resorptive agents -- preventing bone loss -- and anabolic agents -- promoting bone formation -- they are inadequate due to either the limited scope of approval or decreased patient compliance from the perceived high risk of complications. Fracture risk increases significantly in osteopenic individuals with vertebral, hip, wrist, and pelvic fractures being among the most common. While there is a significant annual cost of osteoporotic fractures – on the order of $25 billion annually – the increased rate of mortality after osteoporotic fracture is halting. Risk of mortality one year after hip fracture ranges from 20% to 40%. Therefore, there is a clinical and economic need to develop the next-generation of bone saving therapeutics. Bone has the innate ability to respond to mechanical loading -- forming new bone to accommodate increased mechanical loads, and resorbing bone when there is a period of low mechanical loading or disuse. If we can determine how mechanical loads are detected on the cellular level, we can open up a new avenue for drug development. The osteocyte, a terminally differentiated cell embedded in the bone mineral matrix, is accepted as a key bone mechanotransducer -- detecting mechanical loading and translating it into biochemical signals promoting bone formation. There are several hypothesized models of how the osteocyte detects mechanically loading – fluid flow through the canalicular environment stimulates the osteocyte's dendritic processes; fluid flow results in deformation of the primary cilium within the lacunar cavity; or matrix deformation is directly transduced through integrin attachments at the lacunar wall. The primary cilium is a solitary antenna-like organelle that forms a distinct signaling domain with a unique protein pool, which makes it an attractive therapeutic target. In this thesis, we seek to unravel the role of the primary cilium in bone mechanotransduction in order to open new avenues for drug development. We examine if the osteocyte primary cilium contributes to load-induced bone formation, determine if adenylyl cyclase 3 (AC3) -- a cAMP catalyzing enzyme that localizes to the primary cilium -- contributes to osteocyte mechanotransduction, and investigate if the primary cilium coordinates actin adaptation in response to mechanical loading. Using a Cre-lox system to knockout Ift88, a gene encoding a critical protein for cilia formation, we find that load-induced bone formation is dependent on whether one or two alleles of Ift88 are present globally, but not if they are only deleted in the osteocyte cell population. We also find that knocking down AC3 mRNA expression leads to an increased response to mechanical stimulation and altered primary cilia length, likely through decreased cAMP production. Finally, we determine that inhibiting primary cilia formation dysregulates actin adaptation to mechanical loading and prevents the actin-dependent mechanoresponse of Taz, a transcriptional co-regulator. This action is likely through alterations in the expression of actomyosin components and in the activation of focal adhesion kinases. Together, this work demonstrates that the primary cilium plays a role in load-induced bone formation, but this effect is not localized to the osteocyte cell population. We also show that adenylyl cyclases play a role in osteocyte mechanobiology, and that whole cell mechanosensitivity may be determined through the primary cilium in its function regulating the actin cytoskeleton.

Zebrafish are part of the teleost infraclass (bony fish) of the ray-finned fish. Like other teleosts, zebrafish possess the ability to regenerate most tissues, including their fins. Zebrafish fins contain segmented bony fin rays that longitudinally span the fin. The segments of fin ray are separated by fibrous joints at regularly spaced intervals providing segmentation and flexibility for the fin. Based on gene expression and changes in cell morphology, joint cell differentiation during development and regeneration proceeds through three stages: presumptive joint, joint-forming, and mature joint cells. Our lab has shown that new joint formation correlates with the upregulation of 5’ hoxa gene, hoxa13a. The hox genes encode transcription factors important for patterning in development. In mice, phenotypes resulting from loss- and gain-of-function mutations in Hox genes have revealed that the spatiotemporal expression of these genes is critical for the correct morphogenesis of the limb, a homologous structure to the fin. The first experiments in this thesis use the NTR/MTZ mechanism to partially ablate hoxa13a-expressing cells in the joints and blastema of the regenerating caudal fin. Partial ablation of the hoxa13a-expressing cells results in shorter bone segments following regeneration of the fin. This experiment draws the conclusion that hoxa13a-expressing cells are involved in the regulation of segment length. To examine the function of the 5’ hoxa/d genes in zebrafish, our lab created CRISPR/Cas9 mutations that inactivate hoxa13a, hoxa13b, and hoxd13a. The triple mutants created through serial breeding, show fin-specific defects in the formation and patterning of joints, as well as general defects in the morphology of the ray and in the actinotrichia, collagenous fibres found at the distal edge of the fin. Overall, our data suggest that hox13 genes are necessary for joint formation and proper fin ray growth. With further phenotypic and genotypic analyses our lab proposes that the dosage of hox13 alleles is responsible for anomalies in fin ray formation found in hox13 mutants.

Current therapies for the treatment of myocardial infarction and heart failure include medical, surgical, mechanical assist, and transplantation. These therapies have been based on the dogma that ventricular myocytes themselves are terminally differentiated and, therefore, cannot regenerate. This concept has been recently challenged with stem cell therapy. A potential problem is the ability of cardiac tissue to mobilize, recruit, and transdifferentiate adult stem cells from other tissues. We believe that there is a unique failure of the damaged myocardium to provide the appropriate molecular signals for stem cells engraftment related to age. Our hypothesis is that the overexpression of IL-10 in the aged population reduces cardiac cellular proliferation subsequent to myocardial injury. This hypothesis is supported by aging models, where elevated levels of IL-10 are associated with reduced healing response to noncardiac tissue injury. We demonstrated an increased cardiac gene expression of IL-10 that may be associated with a reduced proliferative response in the border regions of the infarcted myocardium that are proportional with age. In conclusion, myocardial infarction and heart failure has presented a significant challenge for the clinician to provide reparative therapies. The use of therapeutics to modulate IL-10 and, thereby, optimizing regenerative processes in the injured myocardium may provide a unique means for the cardiac patient.

There has been recent concern regarding the regeneration and recruitment of aspen (Populus tremuloides) in the western United States. Forest management techniques have been employed in order to promote the regeneration and recruitment of aspen. We quantified aspen regeneration treatments in southern Utah, USA to better understand the factors driving aspen recruitment. Driving factors were identified by addressing two major research themes: (1) identify the primary ecological controls on aspen regeneration success; (2) assess the relative importance and influence of these controls on successful regeneration. Our definition of successful aspen regeneration requires the satisfaction of two criteria relating to height and density, respectively: (1) regeneration that has attained heights above the ungulate browsing threshold (e.g. >2m); and (2) regeneration that is occurring at a density that represents desired conditions for future stocking (e.g. ≥10,000 stems ha⁻¹). The primary ecological controls on regeneration success were identified using nonmetric multidimensional scaling, and Random Forests analysis was used to assess the relative importance and influence of regeneration controls. These analyses identified three primary factors that are responsible for regeneration success. These factors were (1) contemporary herbivory pressure, (2) site preparation technique, and (3) advance reproduction. Herbivory is the leading predictor of regeneration success, and has integral impacts on other primary regeneration drivers. We suggest considerations that can be made regarding regeneration drivers in order to enhance the effectiveness of aspen management in the future.