Isolation and identification of possible analgesics and antihypertensive agents from antidesma venosum
- Authors: Mashimbye, Mahlori Jeffrey
- Date: 1986
- Subjects: Antidesma , Analgesics , Hypotensive agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3882 , http://hdl.handle.net/10962/d1001616
- Description: This investigation originated from a suggestion by Noristan Laboratories, Pretoria, that because Black people were using the roots of A. venosum E. MEY. ex. TUL for treating headache, the plant might contain analgesics. No previous chemical investigation has been carried out on this plant but from previous work done on other species antihypertensive agents were expected to be present
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- Date Issued: 1986
The Springfontein prospect : a case study of a tertiary age epithermal hot spring deposit in the Eastern Cape
- Authors: Nichols, Richard Lionel
- Date: 1991
- Subjects: Hot springs -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5058 , http://hdl.handle.net/10962/d1012963
- Description: The Springfontein Prospect is a Tertiary aged epithermal Hot Spring deposit that was investigated for precious metal mineralisation. It is located some 14 kilometres due west of East London (Cape Province), within Beaufort Group sediments and Karoo dolerite. Prior to the work described in this case study, the location was known for it's abundant plant fossils and barite mineralisation. A gossan sample collected near the main barite vein returned 1,07 g/t Au and 26,6 g/t Ag. Remote sensing studies of the site revealed a set of north-south lineaments paralleling the barite vein system. Geophysical surveys confirmed this orientation and revealed an extensive alteration system underlying the prominent sinter terrace. A detailed soil geochemical survey returned elevated values in the classical epithermal gold mineralisation element suite (Rg, Tl, As, Bi, Sb, Te, Mo, Ba and Pb - Bonham, 1986). Trenching of geochemical anomalies revealed zones of intense argillic alteration and vein stockworks). Four percussion and three diamond drill holes intersected a 'feeder-fissure' system of veins, alteration and brecciation, but failed to repeat gold levels seen at surface. Mineralogical and petrographic studies of the cores determined temperatures of formation of important indicator minerals (e.g. adularia and zeolites). Litho-geochemical work revealed mercury (and thallium) to be most elevated in the feeder systems. Stratigraphic and paleontological observations determined that the Springfontein Tertiary deposit was clearly different to the other siliceous (silcrete) units that crop out in the Eastern Cape region. A number of distinguished visitors to the prospect, with epithermal deposit experience, confirmed that the characteristics and dimensions of the system is within those of mineralised deposits elsewhere. A brief review of current epithermal models are presented. The conceptual geological model for the Springfontein prospect evolved through the exploration programme. The final consensus is that it best fits Bonham's (1986) alkalic model and the Tertiary epithermal event was sustained by rifting associated with the break-up of Gondwanaland.
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- Date Issued: 1991
Symplasmic pathway in phloem loading and unloading in source and sink leaves of Zea mays L. as evidenced under normal and elevated CO₂ conditions
- Authors: Nogemane, Noluyolo
- Date: 2003
- Subjects: Phloem , Plant translocation , Plant cells and tissues , Corn -- Metabolsim
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4254 , http://hdl.handle.net/10962/d1007813
- Description: Zea mays plants kept at ambient (ca 375ppm) and elevated CO₂ (ca 650 to 700ppm) were used to examine the possibility of a symplasmic loading, unloading and transport pathway in dark-adapted and illuminated (200μmolm⁻²sec⁻¹ ) sink and source leaves. 5,6-carboxyfluorescein diacetate was introduced into the mesophyll cells and symplasmic transfer observed 3h after application. In sink and source leaves exposed to ambient CO₂ and illuminated at 200 molm-2sec-1, the fluorescence front was observed approximately 3cm from the point of application, while in dark-adapted plants, the fluorescence front was observed approximately 1cm from the point of application. Under elevated CO₂ conditions the fluorescence front in illuminated plants appeared to transport faster moving approximately 5cm from the point of application, and in dark-adapted plants, only 3cm from the point of application. Based on the increase in 5,6-CF accumulation under elevated CO₂ conditions, the present study suggests that there was an increase in capacity for assimilate loading and transport under elevated CO₂ conditions. In source leaves, 5,6-CFDA was taken up into the mesophyll cells, loaded symplasmically and transported basipetally. In sink leaves 5,6- CFDA was taken up from basal mesophyll and after symplasmic loading, was transported acropetally where it was offloaded into the younger immature sink region. Transport in the sieve tubes was confirmed by using aniline blue, which was applied 3h after 5,6-CF transport. Aniline blue coupled with 5,6-CF transport studies showed that the sieve tubes of both cross and longitudinal veins are involved in symplasmic unloading, loading and transport processes in sink and source leaves. Apoplasmic uptake of 5,6-CFDA by cut leaves showed that after apoplasmic transport via the transpiration stream, 5,6-CFDA was offioaded to the xylem parenchyma where it was metabolically cleaved , releasing fluorescent 5,6-CF into the xylem parenchyma. Transverse sections cut after 3h of uptake were observed after 120 and 180 min suggesting that a retrieval of solutes occurs from the xylem to the xylem parenchyma, bundle sheath, phloem parenchyma and to the th in-walled sieve tubes. It was not possible to determine if the thick-walled sieve tubes were involved or if they took up 5,6-CF. Given the available data on loading and offioading of assimilates in sink and source leaves respectively, this study demonstrated that a slow symplasmic pathway exists from the mesophyll to the phloem, and that offloading from the phloem in sink leaves can occur via a symplasmic route.
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- Date Issued: 2003
Search engine poisoning and its prevalence in modern search engines
- Authors: Blaauw, Pieter
- Date: 2013
- Subjects: Web search engines Internet searching World Wide Web Malware (Computer software) Computer viruses Rootkits (Computer software) Spyware (Computer software)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4572 , http://hdl.handle.net/10962/d1002037
- Description: The prevalence of Search Engine Poisoning in trending topics and popular search terms on the web within search engines is investigated. Search Engine Poisoning is the act of manipulating search engines in order to display search results from websites infected with malware. Research done between February and August 2012, using both manual and automated techniques, shows us how easily the criminal element manages to insert malicious content into web pages related to popular search terms within search engines. In order to provide the reader with a clear overview and understanding of the motives and the methods of the operators of Search Engine Poisoning campaigns, an in-depth review of automated and semi-automated web exploit kits is done, as well as looking into the motives for running these campaigns. Three high profile case studies are examined, and the various Search Engine Poisoning campaigns associated with these case studies are discussed in detail to the reader. From February to August 2012, data was collected from the top trending topics on Google’s search engine along with the top listed sites related to these topics, and then passed through various automated tools to discover if these results have been infiltrated by the operators of Search Engine Poisoning campaings, and the results of these automated scans are then discussed in detail. During the research period, manual searching for Search Engine Poisoning campaigns was also done, using high profile news events and popular search terms. These results are analysed in detail to determine the methods of attack, the purpose of the attack and the parties behind it
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- Date Issued: 2013
Effect of phosphorus application on dry matter yield and nutrient content of Mucuna Pruriens (L) in Alice
- Authors: Tshwati, Nolubabalo
- Date: 2016
- Subjects: Legumes Phosphorus Fertilizers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12326 , vital:39253
- Description: The use of herbaceous legumes such as Mucuna (Mucuna pruriens) can assist to recapitalize soil fertility depletion and improve livestock productivity in the small holder farming sector of South Africa. The objective of the study was to investigate the effect of phosphorus fertilizer application (0, 20, 40 and 60 kg P/ha) on the dry matter yield and nutritive value of Mucuna pruriens. The study was conducted at University of Fort Hare Research farm in Alice, South Africa. The research design was a randomized complete block design with three replicates per treatment. Data collection included biomass production and nutrient content of Mucuna pruriens. The forage legume was harvested at flowering stage of growth and analysed for chemical composition. The results showed that with the application of 60 kg P/ha Mucuna had the highest (P < 0.05) fresh and dry matter yield of 19.58 kg/ha and 5.41 kg/ha, respectively compared to other treatments. However, all the other treatments differed from one another. Similarly, the fresh stem and leaf fractions yield and their dry matter yields showed the same trend with application of 60 kg P/ha having the greatest yield compared to the other treatments. Nevertheless, all the treatments differed (P<0.05) from one another with P0 having the least yields. The leaf to stem ratio did not show any significant (P>0.05) difference among all the treatments ranging from 1.44 to 1.62 in fresh forage and ranging from 1.31 to 1.50 in the dry forage. In terms of dry matter content, the control treatment had the highest dry matter content of 37.78percent, however, all the other treatments did not differ significantly (P < 0.05) from each other. There was no significant effect of P application (P > 0.05) in terms of ash, EE, ADF, CP, Ca, Mg, K, Na, P, Zn, Cu, Mn and Fe of the whole plant forage among the treatments. The application of 40 kg P/ha fertilizer significantly (P < 0.05) increased the NDF (51.16percent) of the whole plant of Mucuna compared to the other treatments which did not differ (p>0.05) among themselves. Within the stem fraction there were no significant (P > 0.05) differences among the treatments for the ash, EE, ADF, NDF, and CP, hemicellulose, Ca, Mg, K, P, Zn, Cu, Mn and Fe contents. However, the application of 40 kg P/ha fertilizer significantly (P < 0.05) increased the Na (0.05percent) content of the Mucuna stem fraction. In the leaf fraction of Mucuna there was no significant (P > 0.05) differences in terms of ash, EE, ADF, NDF, CP, hemicellulose, Ca, K, P, Zn, Cu, Mn and Fe among the treatments. However, the application of 20 kg P/ha fertilizer significantly (P < 0.05) increased the Mg (0.52percent) of the Mucuna leaves compared to the other treatments. Therefore the study has shown that increase in P application (60 kg P/ha) has no major effect in the nutrient content of Mucuna. Furthermore, it is recommended that Mucuna can be grown as a protein supplement, based on the CP content values that were recorded in this study and to provide maintenance requirements for ruminants. It was therefore concluded that phosphorus fertilization particularly 60 kg P/ha is necessary and required for optimum growth of Mucuna pruriens in order to increase forage yield. Based on the nutrient content result it was concluded that there was no effect of P fertilizer application levels on the nutrient content of Mucuna pruriens in Alice.
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- Date Issued: 2016
Spatio-temporal analyses of woody vegetation cover using remote sensing techniques: the case of Alice - King Williams Town route, Eastern Cape, South Africa
- Authors: Fundisi, Emmanuel
- Date: 2016
- Subjects: Woody plants -- South Africa -- Eastern Cape Vegetation classification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1830 , vital:27564
- Description: Expansion of woody vegetation results in the transformation of a grass-dominated ecosystem to a tree-dominated ecosystem causing land degradation in most semi-arid areas. The imbalance in the natural ecosystem between herbaceous plants and woody vegetation poses a threat to the natural environment. Such changes alter the flow, availability and quality of nutrient resources in the biogeochemical cycle. Most of the dominating woody plants are often unpalatable to domestic livestock. Therefore, the objective is to assess the spatial extent of woody vegetation over time. Knowledge of the spatial and temporal characteristics of woody vegetation dynamics will enable the development of management plans. These characteristics can be derived using remote sensing techniques which have become efficient in such studies. This study aimed to characterize woody vegetation dynamics along the route between Alice and King Williams’s town in Eastern Cape Province South Africa using Landsat data. This aim was achieved by focussing on three specific objectives. The first objective was to compare the performance of multispectral data and Normalized Difference Vegetation Index (NDVI) data of Landsat imagery in mapping woody vegetation cover. The second objective was to investigate the effect of the spatial resolution of remotely-sensed data on discrimination of woody vegetation from other land cover types. The third objective characterised woody vegetation dynamics between 1986 and 2013/2014 using the results from the first objective. The study used Landsat imagery acquired in November or February of 1986, 1994/1995, 2002/2003 and 2013/2014. Due to lack of data which covered the study area two separate dates (November and February) where used for the study resulting in naming the study area western and eastern parts. Unsupervised classification was performed on the multispectral, NDVI and pan-sharpened images to generate four generic land cover classes, namely water, bare land, grassland and woodland. Accuracy assessments of the classified images was done using error matrix. The results showed that the classification based on NDVI images yielded a better overall accuracy than the classification based on multispectral images for the western (83 percent and 75 percent, respectively) and eastern (82 percent and 76 percent, respectively) parts of the study area. Similarly, pan-sharpening resulted in better overall classification accuracy than multispectral, but comparable to the classification of the NDVI images for both the western (82 percent) and eastern (83 percent) parts of the study area. Remote sensing is an effective tool in assessing changes in the physical environment. Landsat imagery is suitable in assessing land cover dynamics given the long-term and free availability of the image. In addition, the large spatial coverage it provides, enables Landsat data to be used on studies that have wide spatial coverage. Classification for the purpose of time-series analysis was then performed on the NDVI images of each date (1986, 1994/1995, 2002/2003 and 2013/2014). Both woody vegetation and grassland experienced changes from 1986 to 2013/2014 with grassland occupying (75 percent) compared to woodland (17 percent) in 1986. In the year 2013/14 grassland occupied 32 percent and woodland occupied 51 percent of the study area. The increase in woody vegetation in the study area can be attributed to livestock rearing and migration of people from the rural to urban areas post-Apartheid. The study output will aid in the development of a database on land cover distribution of the area between King William’s town and Alice town, providing useful information to decision-making and further studies on woody vegetation.
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- Date Issued: 2016
Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
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- Date Issued: 2017