M.Com. (Transport Economics) / The relative importance of road transportation cannot be over-emphasised. As at 30 June 1981 the number of licenced commercial vehicles registered in South Africa was 855 450. Freight transport for reward during 1975 was conducted by 5 588 differen t op era tors throughout South Africa. During 1981 a total mass of 239 576 000 metric tons was transported by professional freight carriers. The total revenue kilometres travelled amounted to 646 332 000 kilometres. Control over road transportation in South Africa is carried out in accordance to the regulations as stipulated in the Road Transportation Act (Act 74 of 1977) and the Road Traffic Ordinance and Regulations (Number 21 of 1966). The aim of the Road Transportation Act is to regulate, in an orderly manner, the economic aspects related to road transport and to ensure that the misallocation of resources are restricted to a minimum. An analysis of the nature and magnitude of regulation in South Africa indicates that during 1983/84 permits were issued to approximately 12 percent of all registered commercial vehicles. The statistics clearly indicate that economic regulation has a meaningful affect on the road transportation industry. The aim of this study is to research the practical implications of economic regulation practices in South Africa. A further aim of the study is to determine to what extent decisions are based on meaningful information and whether it is in line with acceptable theoretical principles. The reason for a research and analysis of this nature is related to the fact that economic regulation leads to high administrative costs for the responsible authorities.

Ovarian cancer, primarily diagnosed at advanced stages of the disease, is the most lethal of all gynaecological malignancies, with a 5-year survival of only 45%. Increasing age and number of ovulations are the primary non-hereditary risk factors, with the median age of onset being 63 years. Considering that risk peaks upon onset of menopause and that 50% of all cases of ovarian cancer have non-ovarian origins, it is believed that the physiological aging of the ovary renders it an appealing pre-metastatic niche. Mutations in the tumor suppressor genes BRCA1 and BRCA2 are the primary hereditary risk factors, accounting for 20-25% of all cases. We have preliminary data showing that BRCA1 mutation carriers tend to develop ovarian fibrosis, a phenomenon that naturally accompanies ovarian aging, at premenopausal ages, whereas age-associated fibrosis becomes evident after menopause in non-carriers. Consistently, BRCA1/2 mutation carriers are at elevated risk for premature cessation of ovarian function. With the median age of cancer onset decreasing from 63 to 50 years of age in BRCA1 mutation carriers, these data collectively suggest accelerated ovarian aging in these women and highlights an association between ovarian aging and increased risk for cancer. As such, we hypothesized that loss of Brca1 in murine ovarian fibroblasts (MOFs) may accelerate the onset of ovarian fibrosis through fibroblast hyperactivation, contributing to ovarian aging. Using primary MOFs isolated from Brca1 LoxP/LoxP mice and adenoviral cre mediated recombination, we generated Brca1 deficient MOFs. RNA sequencing was used to characterize the transcriptomic changes associated with the loss of Brca1. Our findings suggest that Brca1 deficiency in MOFs induces cellular senescence and enhances their myofibroblastic function, likely yielding increased stiffness of the ovarian extracellular matrix due to the dysregulated synthesis and degradation of its constitutive components, contributing to accelerated ovarian aging.

The Southwest Airlines created the low-cost airline business model in 1970s, after aviation liberalization and opening up policies in the U.S. and European, the booming of low-cost airlines. This makes the people who didn¡¦t use aircraft in the past began to take air travel. Many secondary airports in the area caused the travelers a lot of growth by low-cost airlines flight, and promote the region¡¦s tourism, economy and employment opportunities. In view of this, started the study idea of the influence of low-cost carriers on air travel related industry in Taiwan. The Asia¡¦s largest low-cost airline ¡V AirAsia is the subject of this study. Historical data on the low-cost carriers business were collected. Questions for conducting in-depth interviews with experts in air travel industries were devised from the study of these historical data. In addition, a survey of government¡¦s air, tourism data, the influence of low-cost carriers on air travel related industry was developed finally. The results show, the AirAsia to open Taipei route, on the Taoyuan International Airport, retail, hotels and other travel related industries have brought real benefits. The home base of AirAsia is Malaysia, which people came to Taiwan to engage in substantial growth in tourist numbers and to create a substantial growth in tourism foreign exchange earnings. Finally, the results of this study were compared with historical data. It is hope that the results would be able to provide any other countries planning to develop low-cost carriers, some practical reference in planning their air and tourism industries strategies.

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A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy / Alzheimer’s disease (AD) is the most prevalent and progressive neurodegenerative disorder (ND). It is characterized by a progressive decline of cognitive function, complete loss of memory, deterioration of visual capacity and the inability to function independently. According to the World Health Organization (WHO) it is estimated that about 26 million people suffer with AD worldwide. Although the etiology of AD is not fully understood, the aggregation of β-amyloidal (A) peptides that are associated with the formation of extracellular neurotoxin senile plaques and neurofibrillary tangles comprising hyperphosphorylated tau proteins have been recognized as the primary constituents that play a crucial role in AD. Several potential neurotherapeutic agents that can improve the management of AD such as metal chelators and alkaloid drugs have been approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA). Metal chelators [e.g. histidine, Ethylenediaminetetraacetic acid (EDTA) and zinc acetate (ZnAc)] are the main therapy used for modulating Aβ peptide aggregation with biological metals (such as zinc and copper ions) which is associated with promoting neurotoxicity in AD. While alkaloid drugs, such as donepezil, galantamine and rivastigmine, are used to inhibit the enzyme acetylcholinesterase (AChE); memantine is used to block the N-methyl-D-aspartate (NMDA) receptors associated with pathological activation. Despite the availability of these indispensable drugs, the clinical utility of these drugs is hampered by their poor retention and difficulty in bypassing the highly restrictive Blood Brain Barrier (BBB). Therefore this study aimed at developing novel nanoliposomes (NLPs) surface-engineered with chelating and synthetic peptides that are capable of crossing the BBB thus improving delivery efficacy and modulating the extracellular neurotoxicity associated with β-Amyloid aggregates of AD. Furthermore, since this system was designed for a chronic condition, a temporary depot-based polymeric system was integrated for further enhancement of the liposomal half-life, storage and prolonged drug delivery over a period of 50 days. The surface-engineered NLPs produced were spherical in shape, 100-149±28nm ~ size, with a zeta potential range of -9.59 to -37.3mV and a polydispersity index (PdI) of 0.02-0.2. A Box-Behnken experimental design was employed for maximizing the ligand coupling efficiency (40-78%) and drug entrapment efficiency (DEE) that ranged from 42-79%. The optimized peptide-based ligand NLP formulation showed sustained drug release (30% of drug released within 48 hours). Chelating ligands on the surface of NLPs showed 50-68% modulation of neurotoxicity on PC12 neuronal cells induced by ZnAβ (1-42) or CuAβ (1-42) aggregates. When drug-loaded functionalized NLPs were embedded within the temporal hydrophilic hydrogel network/scaffold as an implantable nano-enabled bio-robotic intracranial device (BICD), the physicomechanical and physicochemical dynamics showed improvement of liposomal structure such as the stability, and homogeneity in distribution of the liposomes within the internal core of the hydrogel networks and post-lyophilized scaffold. In vitro studies in simulated cerebrospinal fluid (CSF) showed prolonged release behavior of the drug-loaded functionalized NLPs from the BICD with 50-70% released over 50 days. Scanning Electron Microscopy (SEM) and confocal microscopy confirmed intact liposomal structures within the temporal polymeric scaffold/depot post-fixation and post-lyophilization. Ex vivo studies confirmed cell proliferation and a low level of lactate dehydrogenase (LDH), which is associated with cell membrane damage/injury, after PC12 neuronal cells were exposed to the BICD. In addition, when PC12 neuronal cells were exposed to the BICD high accumulation of galantamine (GAL) into these PC12 neuronal cells was observed post-cultivation. This outcome indicated that the released drug-loaded functionalized NLPs from the BICD were still in their intact form and capable of serving as bio-robotic markers for the delivery of GAL into the neuronal cells in response to AD. Furthermore, intracellular activity validated that the synthetic peptide has the potency for targeted delivery of the drug-loaded NLPs post-release of the BICD in ex vivo studies. Overall, results from this study revealed that the BICD device had superior cytocompatibility and may be suitable for application as a prolonged and targeted delivery system for GAL into neuronal cells to treat AD.

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111 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Pathology, 1975?