Synthesis and biological activity of ajoenes with increased aqueous solubility

The synthesis of four new ajoene analogues is presented in this thesis. The key to the synthesis was gaining access to a phenol derivative containing the ajoene core structure (sulfoxide / vinyl disulfide) that could be functionalised with various substituents. Evaluation of biological activity returned excellent in vitro activity against a WHCO1 oesophageal cell-line, in which a derivative with a methoxycarbonylmethylene substituent (PMB-ester) was shown to be the most active analogue that was fifteen times more active than Z-ajoene with an IC50 of 1.7 M. An aqueous solubility assay reveals that aqueous solubility increased with subsituition and the analogues with amido or acetate substituents were the most soluble ones. The analogues were also shown to enhance the apoptotic effects of two chemotherapeutic drugs Doxorubicin and Vincristine via chemosensitization. This effect was attributed to the presence of at least one p-methoxybenzyl substituent in the structure

The Anti-bacterial effect of Colloidal silver on Streptococcus pyogenes and Staphylococcus aureus in vitro

Abstract: The treatment of bacterial infections has been successfully achieved when antibiotics were first introduced. A short while after the introduction of antibiotics, bacterial strains became resistant to antibiotic treatment, and bacterial infections were potentially fatal once again. This challenge has led to various pursuits of antibiotic alternative treatment. The antibacterial effect of colloidal silver (18 and 20 ppm) was investigated on Staphylococcus aureus and Streptococcus pyogenes in vitro using the microdilution method. Agar disc diffusion method was used as trial run. Zones of inhibition were measured and recorded in the agar disc diffusion method to indicate bacterial inhibition. The Iodonitrotetrazolium chloride dye was added to the 96 well microplate in the microdilution method and colour changes were visually observed. An unchanged clear colour indicated bacterial inhibition. Noticeable colour changes (from a clear colour to purple) indicated bacterial growth. The results from both experimental methods showed that both 18 and 20 ppm colloidal silver had an inhibitory effect against Streptococcus pyogenes, but not against Staphylococcus aureus. This warrants further extensive research on the effect of colloidal silver as an antimicrobial

Fiscal Illusion at the Local Sphere: An Empirical Test of the Flypaper Effect using South African Municipal Data

Despite South Africa’s relatively decentralized governance and administrative structure, an important feature of the country’s intergovernmental fiscal relations system is the gap that exists between the expenditure responsibilities of sub-national authorities and their assigned revenue bases. The resulting vertical fiscal imbalance is mainly addressed via significant intergovernmental transfers to provinces and local governments. This factor presents strong a priori grounds in assuming that in the South African context, the heavy dependence of many local governments on intergovernmental transfers may generate fiscal illusion. Despite this, no significant effort has been geared towards an empirical investigation of the issue of fiscal illusion. This paper extends existing literature on the empirical analysis of fiscal illusion by using the fiscal year 2005/06 financial and expenditure data from 237 local government authorities in South Africa to evaluate the flypaper variant of the fiscal illusion hypothesis. Empirical results indicate that the marginal effects of municipal own-source revenues on local expenditure exceed those of intergovernmental transfers. This outcome yields no statistical evidence in support of the flypaper hypothesis within the context of municipal expenditures in South Africa.Intergovernmental Transfers; Fiscal Illusion; Flypaper E¤ect; South Africa

Contribuição para a sustentabilidade no fornecimento e uso da água em Massingir (Moçambique)

Dissertação de Mestrado, Gestão e Conservação da Natureza, 20 de dezembro de 2018, Universidade dos Açores.Moçambique não é considerado um país com escassez de água. É, porém, altamente vulnerável com respeito à água e inseguro por causa da incerteza crescente na base dos recursos hídricos nacionais. Além da partilha de bacias hidrográficas, a variabilidade anual e inter-anuais de precipitação, a competição na procura de água por sectores económicos em algumas bacias de rios e infraestruturas hídricas subdesenvolvidas, e em grande parte degradada, são alguns dos fatores que justificam essa vulnerabilidade hídrica. Neste contexto é necessário promover a utilização racional da água, sem conflitos e desperdícios, de forma a maximizar o bem-estar social e económico de todos os utilizadores. A falta de cobertura no fornecimento de água e o conflito entre grupos de agricultores e criadores de gado pelo uso da água em Massingir, têm conduzido a situações de tensão social nas comunidades. O trabalho teve como objetivo definir estratégias para o uso sustentável de água em Massingir (Moçambique) onde se recorreu a reuniões, entrevistas, visitas de campo, inquéritos, software Netlogo e através de debates participativos houve como resultados para resolução de conflitos entre agricultores e criadores de gado: 1) Abertura de caminhos próprios que levem o gado até ao local de abeberamento; 2) O gado deve ser sempre acompanhado pelo dono; 3) Os agricultores devem vedar os seus campos; 4) Em caso de devastação de campos agrícolas pelo gado, o proprietário do gado deve ser responsabilizado e deve pagar ao agricultor pelos danos causados. Em relação ao consumo de água, 48 % das famílias obtém água a partir de furos, 16 % tem acesso ao serviço de abastecimento de água do pequeno privado, 30 % compra água nos camiões e 6 % buscam água diretamente da barragem/rio. Esta situação torna essas pessoas vulneráveis as doenças de natureza hídrica, uma vez que água dessas fontes não esta protegida. O sistema de abastecimento de água de pequeno privado só abastece um bairro. O abastecimento de água em Massingir não satisfaz as necessidades básicas do consumo de população e as famílias continuam ainda com problemas de água e algumas consomem água imprópria. As pessoas tiram água na barragem e não pagam nenhuma taxa pela exploração de recurso e aliado a isso, deve-se estabelecer uma taxa pela exploração de água para as pessoas que tiram diretamente da barragem. O pequeno sistema de abastecimento de água deve aumentar a sua capacidade técnica e de cobertura para que água chegue a todos bairros e para que todas famílias tenham acesso a água potável. Devem continuar os esforços de educação da população relativamente à prevenção de doenças de origem hídrica, nomeadamente as visitas porta-a-porta assim como palestras em diversas instituições com vista a disseminar mensagens educativas sobre a prevenção da Malária e Diarreia.ABSTRACT: Mozambique is not considered a water scarce country. It is, however, highly vulnerable to water and insecure because of the growing uncertainty in the national water resources base. In addition to river basin sharing, annual and interannual precipitation variability, competition in the search for water by economic sectors in some river basins and underdeveloped water infrastructure are some of the factors that justify this vulnerability of water resources. In this context is necessary to promote the rational use of water, without conflicts and waste, in order to maximize the social and economic well-being of all users. Lack of coverage in the water supply and conflict between groups of farmers and cattle farmers for the use of water in Massingir have led to situations of social tension in communities. The objective of the work was to define strategies for sustainable water use in Massingir (Mozambique) where meetings, interviews, field visits, surveys and Netlogo software were used and through participatory debates there were results to resolve conflicts between farmers and cattle ranchers: 1) Opening of own roads that lead the cattle to the place of watering; 2) The cattle must always be accompanied by the owner; 3) Farmers must seal off their fields; 4) In case of devastation of agricultural fields by livestock, the owner of the cattle must be held liable and must pay the farmer for the damages caused. Regarding water consumption, 48% of households obtain water from boreholes, 16% have access to small private water supply, 30% buy water from trucks, and 6% seek water directly from the dam / river. This makes these people vulnerable to water-borne diseases, since water from these sources is not protected. The small private water supply system only caters to a neighborhood. The water supply in Massingir does not meet the basic needs of the population consumption and the families still continue with water problems and some consume improper water. People take water from the dam and pay no fee for the exploitation of resources and in addition to this, a fee must be established for the exploitation of water for people who take it directly from the dam. The small water supply system should increase its technical capacity and coverage so that water reaches all neighbourhoods and that all families have access to drinking water; Efforts to educate the population on the prevention of waterborne diseases should continue, including door-to-door visits as well as lectures at various institutions to disseminate educational messages on Malaria and Diarrhea prevention

An evaluation of the role of an Intermediate Care facility in the continuum of care in Western Cape, South Africa

BACKGROUND: A comprehensive Primary Health Care approach includes clear referral and continuity of care pathways. South Africa lacks data that describe Intermediate Care (IC) services and its role in the health system. This study aimed to describe the model of service provision at an IC facility and the role it plays in the continuity of care in Cape Town. METHODS: Sixty-eight patients (65% Response Rate) were recruited in a prospective cohort design over a one-month period in mid-2011. Patient data were collected from a clinical record review and an interviewer-administered questionnaire, administered at a median interval between admission and interview of 11 days to assess primary and second ary diagnosis, knowledge of and previous use of Home Based Care (HBC) services, reason for admission, demographics and information on referring institution. A telephonic interviewer-administered questionnaire to patients or their family members post-discharge recorded their vital status, use of HBC post-discharge and their level of satisfaction with care received at the IC facility. A Cox regression model was run to identify predictors of survival and the effect of a Care-plan on survival. Seventy staff members (82%) were recruited in a cross-sectional study using a self-administered questionnaire to describe demographics, level of education and skills in relation to what they did for patients and what they thought patients needed. RESULTS: Of the 68 participants, 38 % and 24% were referred from a secondary and tertiary hospital, respectively, and 78% were resident of a higher income community. Stroke (35%) was the most common single reason for admission at acute hospital. The three most common reasons reported by patients why care was better at the IC facility than the referring institution was the caring and friendly staff, the presence of physiotherapy and the wound care. Even though a large proportion of the IC inpatients had been admitted in a health facility on the year preceding the study, only 13 patients (21%) had used a Community Health Worker (CHW) ever before and only 25% (n=15) of the discharged patients had a confirmed CHW visit post-discharge. The presence of a Care-plan was significantly associated with a 62% lower risk of death (Hazard Ratio: 0.380; CI 0.149-0.972). Notably, 46% of staff members reported performing roles that were outside their scope of practice and there was a mismatch between what staff reported doing and their actual tasks. In addition, of the 57 patients that could be traced on follow-up 21(37%) had died. CONCLUSION: Patients and family understood this service as a caring environment that is primarily responsible for rehabilitation services. Furthermore, a Care-plan which extends beyond admission could have a significant impact on reducing mortality. IC services should therefore be recognised as an integral part of the health system and it should be accessed by all who need it

An evaluation of the role of an Intermediate Care facility in the continuum of care in Western Cape, South Africa

BACKGROUND: A comprehensive Primary Health Care approach includes clear referral and continuity of care pathways. South Africa lacks data that describe Intermediate Care (IC) services and its role in the health system. This study aimed to describe the model of service provision at an IC facility and the role it plays in the continuity of care in Cape Town. METHODS: Sixty-eight patients (65% Response Rate) were recruited in a prospective cohort design over a one-month period in mid-2011. Patient data were collected from a clinical record review and an interviewer-administered questionnaire, administered at a median interval between admission and interview of 11 days to assess primary and second ary diagnosis, knowledge of and previous use of Home Based Care (HBC) services, reason for admission, demographics and information on referring institution. A telephonic interviewer-administered questionnaire to patients or their family members post-discharge recorded their vital status, use of HBC post-discharge and their level of satisfaction with care received at the IC facility. A Cox regression model was run to identify predictors of survival and the effect of a Care-plan on survival. Seventy staff members (82%) were recruited in a cross-sectional study using a self-administered questionnaire to describe demographics, level of education and skills in relation to what they did for patients and what they thought patients needed. RESULTS: Of the 68 participants, 38 % and 24% were referred from a secondary and tertiary hospital, respectively, and 78% were resident of a higher income community. Stroke (35%) was the most common single reason for admission at acute hospital. The three most common reasons reported by patients why care was better at the IC facility than the referring institution was the caring and friendly staff, the presence of physiotherapy and the wound care. Even though a large proportion of the IC inpatients had been admitted in a health facility on the year preceding the study, only 13 patients (21%) had used a Community Health Worker (CHW) ever before and only 25% (n=15) of the discharged patients had a confirmed CHW visit post-discharge. The presence of a Care-plan was significantly associated with a 62% lower risk of death (Hazard Ratio: 0.380; CI 0.149-0.972). Notably, 46% of staff members reported performing roles that were outside their scope of practice and there was a mismatch between what staff reported doing and their actual tasks. In addition, of the 57 patients that could be traced on follow-up 21(37%) had died. CONCLUSION: Patients and family understood this service as a caring environment that is primarily responsible for rehabilitation services. Furthermore, a Care-plan which extends beyond admission could have a significant impact on reducing mortality. IC services should therefore be recognised as an integral part of the health system and it should be accessed by all who need it

Comparison of conventional DAQ systems and embedded DAQ systems

M. Tech. (Electrical & Electronic Engineering)In this research we compare conventional data acquisition system (DAS) with the embedded data acquisition systems. The performance specifications of 4 different types of DAQ cards are drawn up with special emphasis made on the following parameters: Slew rate, settling time, relative accuracy and system noise. These parameters are taken from 2 conventional DAS and then compared to those taken from 2 embedded data acquisition systems under the same electrical conditions. The embedded DAQ system’s hardware was built using the PIC Microcontroller interfaced to the Digital to Analog Convertors (DAC). MPLAB C18 is used to create a program which communicates with the embedded DAQ system, to transmit generated signals. National Instrument's LabView is used to create a program which communicates with the conventional DAQ system, to acquire external generated signals and retransmit the signals. In most cases the performance of conventional and embedded are close, but one of the embedded DAS seem to be unstable at high frequencies

Investigation of material wear on centrifugal fan impellers

M.Tech. (Mechanical Engineering)Abstract: Material wear formation on centrifugal fan impeller has been a major problem to many process plants in the whole world and this has been regarded as a grey area to many of OEM of extraction fans. TLT ACTOM has designed and manufactured an ID centrifugal fan for Sugar plant situated in Swaziland. The ID fan after a few months of operation the impeller was found to be subjected to wear. Wear initially took place such that the impeller could not last a season which is made of 9 months. The research was conducted to study the behaviour of wear taking place on the impeller material used in sugar mill plant. Establish the uncertainty of what type of wear is taking place and what cause this wear. The study focused on the formation particle flow pattern and minimization of wear to give a solution to fan manufacturers and end-user of the extraction fans. A visit to the plant in Swaziland was organized and during that site visit, bagasse and coal ash samples together with water samples were collected from inside of the venturi wet scrubber after the scrubber has been switched off for over a month for maintenance purposes. These samples were sent to a laboratory to analyse chemical compositions. The test aimed to determine particles sizes, a composition of mass in percentage, elements and mass of a chemical or contaminate per unit volume of water. A physical inspection has been performed on the wet scrubber to inspect if there were any trace that can lead to wear resulting from wet scrubber failing to perform what is expected from it. A correlation on how wear might have taken place on the impeller was conducted by using a CFD simulation. CFD simulation was conducted by using SolidWorks CAD software. Before conducting the simulation, calculations were made to determine parameters to be used as boundary conditions in the simulation software. Calculations were based on the actual centrifugal fan duties provided by the consultant company that was responsible for designing the entire plant system..

The role of Employee Assistant Programme in managing workplace violence : the experience of South African Police Service members in the greater Tzaneen municipality

The purpose of this study was mainly, to explore the role of Employee Assistance Programme (EAP) in managing workplace violence, through looking at the experiences of SAPS members in the Greater Tzaneen Municipality. Workplace violence is both an academic and scientific concept which is receiving increased attention. Even though every employee should experience the workplace as a violence-free and safe environment, where he or she is able to perform his/her duties without fear of harm, this is unfortunately not the reality in most cases. Workplace violence is a reality in the present world and requires the attention of all stakeholders in the work organisation, employees, the employer as well as EAP professionals. The literature has highlighted that workplace violence can take different forms such as physical and psychological, with experiences ranging from bullying, verbal insults, physical assaults, harassment, and intimidation, to abuse and murder (Schiff, 2010:20). Police officers are not exempted from these experiences of workplace violence. Most of the police officers’ experiences of workplace violence which have been reported in the media platforms suggest that these experiences emanate from the general public, or people who are not members of the South African Police Services (SAPS). The qualitative research approach was utilized in this study, to conceptualise and describe the experiences of workplace violence by SAPS members; exploring the effects of workplace violence in the psycho social functioning and work performance and ; exploring the role of EAP in the managing workplace violence. The researcher used semi structured interview Schedule whereby, 15 interviews were conducted with 15 police officers. A collective case study design which focuses on different experiences of workplace violence by police officers was utilised. The findings indicated that workplace violence is well conceptualized and understood by police officers in Greater Tzaneen Municipality. The study also found that police officers experience workplace violence while conducting their daily duties such as attending complaints, doing cell inspections and apprehending alleged perpetrators of crime. Furthermore the respondent indicated that although EAP is available in the Tzaneen cluster office, it is not effective in managing workplace violence. Various recommendations were made from the above findings. The recommendations can assist in managing workplace violence through EAP.Mini Dissertation (MSW)--University of Pretoria, 2019.Social Work and CriminologyMSWUnrestricte

The impact of INSET in the implementation of OBE

M.Ed.The aim of conducting my research is to establish the impact of INSET on the implementation of OBE in the Foundation Phase. I believe that OBE was implemented before the Foundation Phase teachers were thoroughly serviced through INSET programmes conducted by the Curriculum Advisory Section. In my research exercise I conducted interviews with the Foundation Phase teachers and I am also going to request them to completed by classroom observations. The main reason of my research is the fact that the Foundation Phase is the base on which future learning activities are to be built on. If the foundation or base is not well laid out, a lot is going to be affected in the educational process. I discussed my research problem and claim in detail. This is followed by an explanation about how I collected and analysed data. Finally I gave my findings and concluded by some recommendations. I would like to use my findings to guide me on the future arrangement and conduction of INSET programmes with the Senior Phase teachers in order to make it to be more effective