List of Titles

Morphological identification of fungi associated with Eichhornia crassipes (Mart.-Solms) Laubach in the Wouri River Basin, Douala, Cameroon

- Voukeng, Kenfack S N, Coombes, Candice A, Weyl, Philip S R, Djeugoue, F, Hill, Martin P

Authors: Voukeng, Kenfack S N , Coombes, Candice A , Weyl, Philip S R , Djeugoue, F , Hill, Martin P
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/423785 , vital:72093 , xlink:href="https://doi.org/10.2989/16085914.2019.1636760"
Description: In many parts of the world, excess growth of Eichhornia crassipes (Pontederiaceae) poses a serious threat to aquatic environments. In Cameroon, where manual clearing is still undertaken, little is known about fungal diversity associated with the plant, or its potential for biological control. Surveys of the Wouri River Basin in the Littoral Region of Cameroon were conducted during a rainy season (May–October 2014) and a dry season (November 2015–April 2016) at various sites, to identify fungi associated with water hyacinth. Fungi were isolated and identified from symptomatic plant parts collected. In the rainy season, 130 fungal isolates belonging to 12 genera were identified morphologically, whereas 299 isolates belonging to 23 genera were identified during the dry season. With the exception of Fusarium oxysporum and Phytophthora sp., the genera represented new records for Cameroon, and Chaetomium strumarium, Colletotrichum gloesporioides, C. acutatum, C. dematium, Curvularia pallescens and Pytomyces chartarum were considered new host records for E. crassipes in Africa. Isolates of Acremonium zonatum, Chaetomium strumarium, Alternaria eichhorniae, Phytophthora sp. and Rhizoctonia sp. showed the highest frequency of occurrence on E. crassipes in the Wouri River Basin and, given their record as plant pathogens, could be potentially useful in the development of mycoherbicides for this weed in Cameroon.
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Date Issued: 2019

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Morphological influence of deposition routes on lead sulfide thin films

- Mlowe, Sixberth, Shombe, Ginena B, Akerman, Matthew P, Mubofu, Egid B, O'Brien, Paul, Mashazi, Philani N, Nyokong, Tebello, Revaprasadu, Neerish

Authors: Mlowe, Sixberth , Shombe, Ginena B , Akerman, Matthew P , Mubofu, Egid B , O'Brien, Paul , Mashazi, Philani N , Nyokong, Tebello , Revaprasadu, Neerish
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/186780 , vital:44533 , xlink:href="https://doi.org/10.1016/j.ica.2019.119116"
Description: A distorted single crystal structure of bis(piperidinedithiocarbamato)lead(II) complex and its subsequent use to deposit thin films is reported. Two deposition routes namely, aerosol-assisted chemical vapour deposition (AACVD) and spin coating deposition have been employed to obtain anisotropic lead sulfide (PbS) nanostructures. The thin films displayed rod to cubic shaped crystals for AACVD, and a range of cubes, star and dendritic morphologies with variation of temperatures were displayed for spin coated films. Optical band gaps between 1.32 and 1.55 eV as controlled by the change in temperature were observed for thin films deposited by AACVD. Powder X-ray diffraction (P-XRD) studies show that the films formed are composed of cubic crystalline PbS. The X-ray photoelectron spectroscopy (XPS) was used to investigate the effect of activation temperatures (350, 400 and 450 °C) on the chemical composition and oxidation states of PbS samples.
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Date Issued: 2019

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Movement and predation: a catch-and-release study on the acoustic tracking of bonefish in the Indian Ocean

- Moxham, Emily Jeanne, Cowley, Paul D, Bennett, Rhett H, von Brandis, Rainer G

Authors: Moxham, Emily Jeanne , Cowley, Paul D , Bennett, Rhett H , von Brandis, Rainer G
Date: 2019
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/103946 , vital:32325 , https://doi.org/10.1007/s10641-019-00850-1
Description: Tourism generated through bonefish (Albula spp.) fishing contributes to the economies of many isolated tropical islands and atolls. However, little research has been conducted on bonefish in the Indian Ocean. This study aimed to contribute to the understanding of bonefish ecology in the Indian Ocean by quantifying the spatial and temporal movements of Albula glossodonta at a near-pristine and predator-rich atoll in the Seychelles; however, to achieve this, an analysis to identify the occurrence of possible post-release predation bias was first necessary. An acoustic telemetry study was initiated at the remote St. Joseph Atoll, within an array of 88 automated data-logging acoustic receivers. Thirty bonefish were surgically implanted with Vemco V13 acoustic transmitters and tracked for one year. Only 10% of the tagged bonefish were detected for longer than two weeks. A comparison of the final 100 h of movement data from fish detected for less than two weeks to the movement data of the fish detected for longer periods revealed distinct differences in area use and significant differences in the average daily distance moved, speed of movement and frequency of detections. This suggested that mortality in the form of post-release predation was at least 43% of tagged fish. The three surviving bonefish were tracked for 210 to 367 days. These individuals remained in the atoll and showed high use of the marginal habitats between the shallow sand flats and the lagoon. A generalised linear mixed model identified that water temperature, diel cycle and tide were significant predictors of bonefish presence in the lagoon. The high post-release mortality highlights that catch-and-release is likely not as benign as previously believed and management and policy should be adjusted accordingly.
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Date Issued: 2019

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Mulling over Art with Andrew Mulenga: Vincentio solo yields mixed reviews from ZAOU students

- Mulenga, Andrew

Authors: Mulenga, Andrew
Date: 2019
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/146804 , vital:38559 , https://www.themastonline.com/2019/05/28/mulling-over-art-vincentio-solo-yields-mixed-reviews-from-zaou-students/
Description: Every semester, the Zambian Open University’s Bachelor of Arts in Fine Art residential programme and examination periods include several field trips that involve visits to museums, art galleries, private collections, public discussions as well as theatre and film production houses within Lusaka. Among the many tours this semester was a visit by a combined group of over thirty 2nd, 3rd and 4th year students from across the country to Zambian abstract maestro Vincentio Phiri’s solo exhibition entitled “Omission” that ran at the Zambia Ultra Gallery at Garden City Mall on Great East Road in Lusaka from 14th to 30th April.
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Date Issued: 2019

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Multi-angled face segmentation and identification using limited data

- Brown, Dane L

Authors: Brown, Dane L
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/465711 , vital:76634 , xlink:href="https://ieeexplore.ieee.org/abstract/document/9067899"
Description: This paper introduces a different approach to face segmentation that aims to improve face recognition when given large pose angles and limited training data. Face segmentation is achieved by extracting landmarks which are manipulated in such a way as to normalize unseen data with a classification model. The approach is compared with related systems, followed by further tests that show consistent results across other datasets. Experiments include frontal and non-frontal training images for classification of various face pose angles. The proposed system is a promising contribution, and especially shows the importance of face segmentation. The results are achieved using minimal training data, such that both accurate and practical face recognition systems can be constructed.
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Date Issued: 2019

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Multi-directional effects of warming temperatures on the reproductive success of a threatened alpine-endemic bird, and implications for conservation management

- Oswald, Krista N, Lee, Alan T K, Diener, John P, Diener, Elizabeth F, Cunningham, Susan J, Smit, Ben

Authors: Oswald, Krista N , Lee, Alan T K , Diener, John P , Diener, Elizabeth F , Cunningham, Susan J , Smit, Ben
Date: 2019
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/441624 , vital:73902 , https://eco.confex.com/eco/2019/meetingapp.cgi/Paper/78223
Description: Mitigating the current biodiversity crisis requires a better understanding of how species will respond to future climate change and human impacts on habi-tat. Decreased reproductive capability, due to changes in phenology, output, and success, is one of the main indicators of species’ vulnerability. For terres-trial ground-nesting birds, overall reproductive success is often related to nest-site selection (e.g. increased nest concealment), and weather changes (e.g. higher air temperatures alter nest success). We investigated the reproductive success of Cape Rockjumpers (Chaetops frenatus; “Rockjumpers”), a ground-nesting alpine bird, endemic to the Fynbos biome of South Africa, whose popu-lation decline correlates to warmer temperatures. We predicted that breeding success would be positively correlated with increased nest concealment, and negatively correlated with increasing temperature. We collected data over three years, including two full breeding seasons, from 2016 to 2018 (n=5, n=20 and n=43 respectively), which included nest-site selection variables (i.e. vege-tative cover, rock cover, time since fire in years), success or failure (whether nest resulted in ≥ fledgling), and cause if nest failed (i.e. predation events, weather). We tested the overall success in relation to nest-site selection varia-bles, and then examined how nest failure (specifically snake predation) was correlated with air temperature.
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Date Issued: 2019

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Multi-drug resistant tuberculosis related adverse drug reactions: implementation of a documentation tool

- Cheng, Amber

Authors: Cheng, Amber
Date: 2019
Subjects: Multi-drug resistant tuberculosis
Language: English
Type: Thesis , Masters , MPharm
Identifier: http://hdl.handle.net/10948/44662 , vital:38151
Description: Multi-drug resistant tuberculosis (MDR-TB) is an ever-growing problem in South Africa (SA). According to the literature, minimal documentation is done on adverse drug reactions (ADRs), specifically in the MDR-TB population. Co-administration of medications is typical for the treatment of drug resistant forms of TB, which leads to high incidences of ADRs during the treatment period, especially in patients with comorbid disease states. This before-and-after study investigated the impact of an intervention (education training presentation and implementation of a purpose-designed documentation tool) on the current documentation pattern in a public sector hospital in the Nelson Mandela Metropole. In order to measure the sustainability of the intervention, the study compared data from the pre-intervention phase to data collected from the post-intervention immediate phase and post-intervention delayed phase. Study results indicated that the intervention appeared to have had a positive effect on the frequency and variety of ADR documentation (2.1 and 1.3 fold increase, respectively) related to MDR-TB by the hospital staff of a public sector hospital, however, the positive change was not sustainable for longer than a three month period post intervention. It is recommended that factors such as: proper adoption; management; and additional resources are required to implement positive changes to documentation practices. Further studies need to be conducted in South Africa regarding the treatment of drug resistant tuberculosis, in order to establish safer treatment guidelines and more promising ADR reporting practices, which will ultimately improve patient care.
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Date Issued: 2019

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Multi-temporal assessment of chlorophyll-a concentration in estuarine waters: a case study of sundays and swartkops estuaries, Eastern Cape Province

- Gwazani, Nothando

Authors: Gwazani, Nothando
Date: 2019
Subjects: Chlorophyll -- South Africa Estuaries -- South Africa
Language: English
Type: Thesis , Masters , MSc (Applied Remote Sensing & GIS)
Identifier: http://hdl.handle.net/10353/11972 , vital:39123
Description: Estuaries are productive and delicate marine systems, which are of commercial, recreational and aesthetic value as they reflect the land use of a catchment by creating “nutrient traps”, these nutrients are absorbed by water and later released into the coastal oceans. Disturbances in an estuary influence a wide variety of habitats and organisms in a marine ecosystem, for example, high chlorophyll-a affects marine species that utilize calm waters, food and turbid water found in estuaries. The degradation of South African estuaries is an on-going accelerating process; therefore, there is a need for preservation measures for estuarine ecosystems by means of monitoring nutrient flow. This research was aimed at assessing the use of OLCI ocean color products in monitoring chl-a concentration and impacts of the estuaries in Algoa Bay. OLCI on the Sentinel platforms, coupled with OCNN and OC4ME algorithms were employed to assess the distribution of chlorophyll-a in Swartkops and Sunday’s estuaries. OC4Me and OCNN are the default models designed for OLCI data. However, the OLCI resolution was not able to measure the chl-a concentration within these estuaries. Therefore, satellite product assessment was primarily focused on the Algoa bay scale due to the resolution of the available data. SNAP and Matlab were applied for the production of the final products. Accuracy assessment was used to check the agreement between the in situ datasets of chl-a and the final processed satellite products. Results of this investigation point that OCNN did not perform well in the study as compared to OC4Me and it did not produce accurate results in areas with very high biomass concentration. The research concludes by recommending the use of higher resolution data such as Sentinel 2 MSI (10m, 20m, and 60m resolution) for resolving chlorophyll-a within these estuaries.
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Date Issued: 2019

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Muscle nanostructure and physicochemical characteristics of South African A and AB mutton classes

- Mdikili, Zizipho

Authors: Mdikili, Zizipho
Date: 2019
Subjects: Meat -- Quality -- South Africa
Language: English
Type: Thesis , Masters , (MSc) (Animal Science)
Identifier: http://hdl.handle.net/10353/12005 , vital:39126
Description: Significant variations exist in quality of red meat due to the effect of various intrinsic and extrinsic factors. Research has been conducted in early 1990s to prove that carcasses from A and AB classes differ in meat quality due to age variation. This led to a conclusion that the two should be separated in the South African Red meat Classification System (SARCS). However, an interesting debate arose from a carcass classification workshop that A and AB meat classes have the same quality and thus must be integrated into one class in the carcass classification system. In addition, as much as it can be debated that these classes have the same quality, it is also possible that slight differences exist between the two since they are from different age groups. The current study was therefore developed and two trials were conducted to evaluate the impact of age differences on physicochemical attributes and muscle nanostructure of A and AB classes in sheep. In the first trial a total of ninety (n=90) Dorper sheep of the same sex but different age groups slaughtered at a high throughput abattoir in the Eastern Cape province were used to evaluate meat ultimate pH (pH24), colour (L* , a* , b* , H* , C* ), thawing loss (TL%), cooking loss (CL%) and tenderness (Warner Bratzler Shear Force - WBSF) of A and AB classes, whereas, on the second trial forty (n=40) Dorper sheep were used to evaluate muscle nanostructure and its relationship with tenderness. Meat samples were harvested from the Muscularis longissimuss thoracis et lumborum (LTL) for v meat quality and nanostructure measurements. The results showed significant variations (P<0.05) between the two classes for lean a* , H* and CL%. Significant differences (P<0.01) were observed in pH24, TL% and WBSF between A and AB classes. However, there were no significant differences (P>0.05) observed in meat L*, b* and C * . Ultimate pH was negatively correlated with thawing loss and some colorimetric attributes of lamb such as lightness, yellowness and hue angle. Moreover, tenderness was positively correlated with cooking and thawing losses. Significant differences were not (P>0.05) observed in sarcomere length, myofibrilar diameter and shear force between A and AB classes. Both sarcomere length and myofibrilar diameter were not correlated (P>0.05) with meat tenderness. These results suggest that A and AB classes are the same in nanostructure and that muscle nanostructure of these two classes is not related to meat tenderness. It was concluded that meat from sheep carcasses falling under the A and AB classes in the South African classification system vary greatly in physicochemical quality. Moreover, sheep carcasses from A and AB classes have the same sarcomere lengths and hence, they do not differ in meat tenderness (WBSF). However, when these classes were observed under a microscope, slight differences were noted in sarcomere lengths and myofibrilar diameters, which led to a conclusion that the two should remain as separated classes because their combination would result in the expansion of the non-uniformity of red meat tenderness. Therefore, A and AB classes should not be combined in the South African classification system. Further research is, however, recommended to evaluate the influence of other factors that were not examined in the current study.
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Date Issued: 2019

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Muscle nanostructure, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus

- Soji, Zimkhitha

Authors: Soji, Zimkhitha
Date: 2019
Subjects: Meat -- Quality
Language: English
Type: Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10353/15264 , vital:40332
Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
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Date Issued: 2019

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Music listening and its cognitive effect on learning

- Freer, Angela Elizabeth

Authors: Freer, Angela Elizabeth
Date: 2019
Subjects: Music -- Psychological aspects , Music therapy Cognitive learning Music appreciation
Language: English
Type: Thesis , Masters , MMus
Identifier: http://hdl.handle.net/10948/39807 , vital:35462
Description: This experimental study focuses on the activity of music-listening and its effect on students’ learning and memory. This is particularly relevant today given the ‘sound-consuming culture’ which results from advanced multimedia technologies. To determine music-listening’s effect on students, we examined the cognitive effect that music-listening had on their memory and learning. A non-probability convenience sampling technique was employed to recruit a limited population of 227 male and female participants from three Port Elizabeth high schools between the Grades of 8 and 9. A ‘two group design’ was used with 189 students (54 males; 123 females) completing a word-recall test and reading comprehension test. During the first round of testing all participants completed both tests under the first music treatment condition: silence. During the second round of testing, a second set of tests was provided with the experimental group placed under a treatment condition of self-selected background music while the control group remained under the condition of silence. Independent sample t-tests were used to analyse the data of this study. The results showed that listening to self-selected background music had a negative cognitive effect on students’ memory and learning during the completion of the word-recall tests. However, no significant effect was found in students’ ability to complete a reading comprehension. In addition, this study also showed that female students seemed to have significant negative cognitive effect during the word-recall test. The findings of this study therefore showed that, depending on the task, word-recall tests (but not reading comprehension tests) were cognitively affected by music-listening.
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Date Issued: 2019

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