Development and in vitro biological studies of polymer-based wound dressings with a high haemostatic ability for the management of wounds
- Authors: Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- Date: 2022
- Subjects: Wound healing , Surgical wound infections , Wound treatment equipment industry
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27970 , vital:71404
- Description: Wounds are usually accompanied by complications such as excessive bleeding and bacteria invasion. The design of wound dressings that rapidly stop excessive bleeding and inhibit bacterial invasion is crucial to promoting accelerated wound healing. To meet the abovementioned requirements in wound dressings, topical gels were prepared from sodium alginate SA and carboxymethylcellulose CMC. The wound dressings were loaded with an antifibrinolytic agent, tranexamic acid TA, essential oils, and a variety of metal-based nanoparticles, and carbon-based biomaterials. The scanning electron microscopy SEM and X-ray diffraction XRD confirmed the successful formation of the nanoparticles. The prepared formulations exhibited in vitro drug release kinetics that best fitted with the Korsmeyer-Peppas model. These gels exhibited good spreadability and viscosity, showing a shear-thinning behaviour with pH between 6.7 and 7.3, signifying suitability for skin application and ease of application. The prepared topical gels exhibited significant antibacterial effects against gram-negative and gram-positive strains of bacteria. SA EO-based formulations showed high antibacterial activity across all bacterial strains, followed by SA-based formulations compared to CMC-based formulations, which exhibited moderate antibacterial activity. Moreover, the prepared gels showed good cytocompatibility, promoted cell proliferation, and exhibited 80 percent wound closure on day 3 compared to the untreated group, which showed a 38 percent wound reduction in vitro. Excellent blood clotting properties were observed with CMC-based gels compared to other formulations. However, all the prepared formulations exhibited outstanding blood clotting ability compared to the control, showing that they can promote rapid blood coagulation. The features presented by the prepared gels reveal that they are suitable for rapid wound healing , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
Development and validation of DNA barcoding for biodiversity assessment and conservation of red algae in the Algoa Bay region
- Authors: Mshiywa, Faith Masilive
- Date: 2017
- Subjects: Red algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9011 , vital:34182
- Description: DNA barcoding is a molecular technique that uses a short DNA sequence for species identification. It harnesses global community efforts to establish large-scale public reference libraries to allow species identification. Red algae are a complex group of species and are difficult to identify on morphological grounds only. Red algae have the highest production of halogenated compounds, and are used in the medical and pharmaceutical industries. This study therefore aimed at developing DNA barcodes, universal primers and a Kenton-on-Sea red algae species list, which will aid as a baseline for red algae biodiversity and conservation research. A potential DNA barcode region was designed from the rbcL gene, because rbcL is easy to amplify, easy to sequence and it can differentiate organisms to species level. Primers were designed from multiple red algae rbcL sequences and they were evaluated using bioinformatics tools. Red algae from the Algoa Bay region were screened with these primers and a 77% PCR amplification success was obtained. The PCR products were sequenced and 96% of the amplicons were successfully sequenced and resulted in a barcode sequence length above 700bp, which could be used to identify red algae species. Twenty-six (26) red algae species from Kenton-on-Sea, near Algoa Bay, were successfully identified using the Barcode sequence amplified from a primer set developed from the rbcL gene and were uploaded on the BOLD database for public access. This barcode is, therefore, suitable for use by the South African National Biodiversity Institute or other marine researchers, to identify South African red algae species and ensure the maintenance of their biodiversity and conservation.
- Full Text:
- Date Issued: 2017
Development of a Mobile-Based Livestock Breeding Management System for Communal Farmers in Eastern Cape, South Africa
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Development of an automatic news summarizer for isiXhosa language
- Authors: Ndyalivana, Zukile
- Date: 2017
- Subjects: Text processing (Computer science) Automatic abstracting Computational linguistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7875 , vital:30783
- Description: From practice perspective, given the abundance of digital content nowadays, coming up with a technological solution that summarizes written text without losing its message, coherence and cohesion of ideas is highly essential. The technology saves time for readers as well as gives them a chance to focus on the contents that matter most. This is one of the research areas in natural language processing/ information retrieval, which the dissertation tries to contribute to. It tries to contextualize tools and technologies that are developed for other languages to automatically summarize textual Xhosa news articles. Specifically, the dissertation aims at developing a text summarizer for textual Xhosa news articles based on the extraction methods. In doing so, it examines the literature and understand the techniques and technologies used to analyse contents of a written text, transform and synthesize it, the phonology and morphology of the Xhosa language, and finally, designs, implements and test an extraction-based automatic news article for the Xhosa language. Given comprehension and relevance of the literature review, the research design, the methods and tools and technologies used to design, implement and test the pilot system. Two approaches were used to extract relevant sentences, which are, term frequency and sentence position. The Xhosa summarizer is evaluated using a test set. This study has employed both subjective and objective evaluation methods. The results of both methods are satisfactory. Keywords: Xhosa, Automatic Text Summarization, Term Frequency and Sentence Position.
- Full Text:
- Date Issued: 2017
Development of an Extensible Framework for Easy Implementation of Image Processing Applications on Android Operating System
- Authors: Gunu, Bulelani
- Date: 2019
- Subjects: Operating systems (Computers)
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/17201 , vital:40865
- Description: Image processing is a field that has been in existence for many years and it continues to grow with many other research areas adopting its use. One such research area is the area of mobile devices. Mobile devices have been equipped with image processing software and hardware so as to apply image processing features. While there are many applications of image processing and new applications have been developed, there are still many functionalities that these image processing software perform the same. The development of these software from scratch requires a lot of effort and can be time consuming. This becomes even worse for mobile device application developers, specifically Android developers, who have no knowledge of implementing image processing functionalities. This project offers a software framework which allows Android application developers to focus on their unique requirements while incorporating image processing features into their applications. The framework provides the common image processing functionalities and Android developers do not need to know the internal working of the framework in order to use it. This helps reduce application development time and effort. The framework also offers an extensibility feature which takes into consideration the future growth. This means that third party developers can keep the framework up to date with the technological advancements. The presented framework is shown to be requiring less technical expertise. Also, the way in which the system is design makes it easy to understand. This design can be adopted for other related projects that require extensible frameworks for the Android operating system.
- Full Text:
- Date Issued: 2019
Development of conservation strategies for Alepidea Amatymbica ECKL. & ZEYH. : a rare medicinal plant in the Eastern Cape, South Africa
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
Development of part-of-speech tagger for Xhosa
- Authors: Delman, Xolani
- Date: 2016
- Subjects: Computational linguistics -- Methodology Natural language processing (Computer science) Linguistic models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11872 , vital:39114
- Description: Part-of-Speech (POS) tagging is a process of assigning an appropriate part of speech or lexical category to each word in a given sentence of a particular natural language. Natural languages are languages that human beings use to communicate with one another be it Xhosa, Zulu, English etc. POS tagging plays a huge and important role in natural language processing applications. The main applications of POS tagging include machine translation, parsing, text chunking, spell checkiXhosa (sometimes referred to as isiXhosa) is one of the eleven official languages of South Africa and is spoken by over 8 million South Africans. The language is mainly spoken in the Eastern Cape and Western Cape provinces of the country. It is the second most widely spoken native language in South Africa after Zulu (sometimes called isiZulu). Although the number of speakers might seem to be high, Xhosa is considerably under-resourced. There are very few publications in Xhosa, very few books have been published in the language and also the domains that use the language as a medium of instruction are very limited. However, the language is finding momentum nowadays. An Oxford approved Xhosa dictionary has been developed recently, and Xhosa newspapers that did not exist in the recent past are now published. Text from previously mentioned sources can then be combined to formulate a larger text that can be used to train the tagger. This work aims to develop an effective POS tagger for Xhosa. g and grammar. This thesis presents/describes the work that needed to be done to produce an automatic POS tagger for Xhosa. A tagset consisting of 36 POS tags/labels for the language were used for this purpose. These are listed. A total of 5000 words were manually tagged/labelled for the purpose of training the tagger. Another 3000 words were used for testing the tagger and these were disjoint from the manually tagged training data. The open source Stanford CoreNLP toolkit was used to create the tagger. The toolkit implements a Maximum Entropy machine learning model which was applied in the development of the tagger presented in this thesis. The thesis describes the implementation and testing processes of the model in detail. The results show that the development of the Xhosa POS tagging model was successful. This model managed to obtain a tagging accuracy of 87.71 percent.
- Full Text:
- Date Issued: 2016
Differential regulation of wheat (Triticum aestivum) callose synthases during Russian wheat aphid (diuraphis noxia)infestation
- Authors: Ngwenya, Nompilo
- Date: 2017
- Subjects: Russian wheat aphid Wheat -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8100 , vital:31522
- Description: Plant production serves as the primary food source for all living beings and is continuously being affected by many biotic and abiotic factors. Wheat, one of the most consumed cereal crops in the world and the second most cultivated crop after maize in South Africa, is continuously being affected by Russian wheat aphid (RWA) since 1978. To counteract the effect of this aphid, the first resistant wheat cultivar was developed in 1984 in South Africa containing the Dn1 resistance gene. However, the mechanism of action of the resistance is still not fully understood to date. The feeding of the RWA on the wheat induces callose deposition especially in susceptible wheat cultivars, linking the β-1.3-polysaccharide (callose) to the resistance mechanism. Callose is synthesized by callose synthases, also known as glucan synthase-like genes (GSL). Not much is known about the mechanism of action of callose synthases or how they are regulated in response to the RWA. Bioinformatics tools, such as those available at NCBI, were used to identify the wheat callose synthases genes. The proteins encoded by the identified wheat callose synthases genes, were then analyzed for conserved domain motifs using the MEME suite and InterproScan, sequence similarities using ClustaL Omega and transmembrane domains using HMMTOP and ProtCamp. These were then compared with those of the already characterized Arabidopsis callose synthase proteins in an attempt to identify the wheat callose synthase(s) that responds to aphid feeding. Further bioinformatics studies were carried out to identify the presence of biotic stress associated cis-acting regulatory elements found in the 1.5 kbp upstream region of the start codon of the Arabidopsis callose synthase genes. Eight partial wheat callose synthase sequences were identified and two of these (TaGSL2 and TaGSL22) showed high similarities to the AtGSL5, which is up-regulated in response to aphid feeding in Arabidopsis. Six of the wheat callose synthase genes were mediated to code for the functional callose synthases proteins: TaGSL3, 8, 12, 19, 22 and 23, and analyzed for conserved protein motifs. Based on the sequence similarities and conserved protein domains, TaGSL2 and TaGSL22 were found to be the most similar to AtGSL5 and most likely to respond to RWA infestation. Cis-acting regulatory element analyses confirmed the possibility of TaGSL22 being responsible for callose deposition in wheat as biotic stress associated cis-acting regulatory elements, Box W1, TC- rich element and W- box were all found in the 1.5 kbp upstream of the TaGSL22 coding region. Callose was quantified in both susceptible and resistant wheat cultivars using the aniline blue fluorescence method. When infested with RWA-SA1, the susceptible wheat cultivar (Tugela) deposited significantly higher amounts of callose, compared to the resistant wheat cultivar (Tugela DN), which deposited little, to no callose with respect to the control samples. Transcription analysis, of the TaGSL2 and TaGSL22 in RWA-SA2 infested Tugela and Tugela DN wheat cultivars, was performed using real time polymerase chain reaction (qPCR). Both TaGSL2 and TaGSL22 genes were up-regulated in Tugela and Tugela DN wheat cultivars in response to RWA-SA2 infestation, with TaGSL22 being more expressed than TaGSL2 in both cultivars, indicating that RWA-SA2 is able to overcome the resistance of Tugela DN and cause callose deposition. However, significantly higher expression of both genes was still observed in the susceptible, Tugela wheat cultivar. This study therefore confirms that callose deposition is associated with RWA-SA1 feeding, only in the susceptible wheat cultivar, Tugela and not the resistant cultivar, Tugela DN. However, during RWA-SA2 feeding, two of the eight identified callose synthases in wheat, are up-regulated in response to RWA-SA2 feeding, in both the resistant and susceptible wheat cultivars with higher levels observed in the susceptible wheat cultivar when compared to the resistant wheat cultivar. TaGSL2 and TaGSL22 are therefore implicated in the callose deposition observed in the susceptible and resistant wheat cultivars, after RWA-SA2 infestation. Further studies are required to confirm the differential regulation of the two wheat callose synthases proteins during RWA infestation and their possible role in the resistance mechanism of the resistant wheat cultivar, Tugela DN.
- Full Text:
- Date Issued: 2017
Distribution of culturable vibrio species in freshwater resources of Cacadu, or Tambo and Chris Hani district municipalities
- Authors: Gaqavu, Sisipho
- Date: 2017
- Subjects: Vibrio--South Africa--Eastern Cape Vibrio infections--South Africa--Eastern Cape Foodborne diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11571 , vital:39085
- Description: Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29percent) followed by V. vulnificus (4percent), V. fluvialis (4percent) and the least was V. parahaemolyticus (3percent). The remaining unidentified 60percent were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83percent of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use.
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- Date Issued: 2017
Distribution of Escherichia coli O157:H7 in irrigation water, drinking water troughs, dairy wastewater and rectal swabs from three dairy farms in Amathole district municipality, Eastern Cape, South Africa
- Authors: Myataza, Asive https://orcid.org/0000-0001-5483-122X
- Date: 2016
- Subjects: Escherichia coli O157:H7 , Irrigation water
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10353/24150 , vital:62397
- Description: Escherichia coli belongs to the genus Escherichia which has five species, including E. hermanii, E. fergusonii, E. vulneris, E. blattae and E. coli (Willshaw et al., 2001). Some E. coli strains are pathogenic, and such strains are differentiated into different pathotypes based on the virulence factors they possess, mechanisms of pathogenesis, clinical manifestation and serotyping of their somatic, flagella and capsule (O, H and K) antigens; while some are nonpathogenic (Dikobe et al., 2011). These strains have been grouped into major pathotypes namely: enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), diffusely adherent E. coli (DAEC), enterohaemorrhagic E. coli (EHEC), uropathogenic E. coli (UPEC) and neonatal meningitis E.coli (NMEC) (Willshaw et al., 2001; Villegas-sepulveda et al., 2003; Kaper et al., 2004; Bugarel et al., 2011). Members of EPEC pathotype are Shiga-toxin producing (STEC) organisms, with E. coli O157:H7 serotype being recognized as the most frequent STEC serotype linked to diseases in human (Barkocy-Gallagher et al., 2001; Coombes et al., 2011; Dikobe et al., 2011; Jacob et al., 2013). E. coli O157:H7 is the major cause of haemorrhagic diarrhoea and haemolytic uremic syndrome (UHS) in humans, due to the production of Shiga-toxins that are similar to Shigella toxins (Villegas-sepulveda et al., 2003; Ngwa et al., 2013). These toxins are coded by genes which allow them to penetrate small intestines of human and animals (Chern et al., 2011). Dairy products and cattle are the major reservoirs of haemorrhagic E. coli O157: H7 (Elder et al., 2000; Elmali et al., 2005; Ayaz et al., 2014). Haemorrhagic E. coli O157:H7 is carried mostly in the gastrointestinal tracts of cows and other ruminants (Gun et al., 2003)and it is transmitted through ingestion of contaminated food and water, or through direct and indirect contact with infected cows and other ruminants and/or via a person to person transmission (Lahti et al., 2003). Almost 70percent of countries in the world use poorly treated water for irrigation; this is inclusive of developing countries, which lack well developed means of adequate water treatment due to unavailable financial resources (Gerba et al., 2011). Most communities in the Eastern Cape Province of South Africa are rural with poor water supply with majority of them relying on ground and surface waters that are impacted by insufficiently treated municipal water (which may harbour many pathogens) for domestic purposes (Ateba et al., 2008). Cows may contaminate drinking, recreational and irrigation waters with faecal matters or through direct contact with water (Solomon et al., 2002; Chern et al., 2011). A number of countries with water shortage tend to use insufficiently treated water for irrigation, leading to further contamination of irrigated crops (Fatoki et al., 2001). This has all resulted to elevated levels of E. coli O157:H7 related disease outbreaks and deaths of humans (Olsen et al., 2002). , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016
Distribution of virulence determinants in Plesiomonas shigelloides and Vibrio species isolated from selected hospital wastewater effluents in the Eastern Cape Province, South Africa
- Authors: Mashudu, Mavhungu
- Date: 2018
- Subjects: Vibrio
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14505 , vital:39996
- Description: Plesiomonas shigelloides and some Vibrio species are amongst the bacteria species classified into the emerging pathogenic bacteria grouping, and they portend increasing virulence and high resistance to some of the most potent antimicrobial agents used as most important and critical lines of defence against pathogenic infectious agents. Hospital wastewater has attracted significant attention as a pool for the regurgitation of pathogens into the environment which eventually becomes a problem to public health. It has been variously reported that hospital wastewater critically serves also as a puddle for microbial genetic interaction with outcomes including the development of resistance to antimicrobial agents among other pathogenic traits. And, in the same vein, exchanges and gene recombination may have been leading to the emergence of virulence determinants not previously known owing to the capacity of hospital wastewater to encompass a vast diversity of pathogenic bacteria and antimicrobial agents at the same material time. Hence, this research aimed at the evaluation of the prevalence of virulence and antibiotic resistance in Plesiomonas shigelloides and some human pathogenic Vibrio species isolated from selected hospital wastewater in the Eastern Cape Province of South Africa. Wastewater samples were collected at two weeks intervals throughout three months sampling duration from hospital wastewater facility in the Eastern Cape Province. The wastewater samples were from the secondary hospital and, tertiary hospital along with Limbede community wastewater facilities based in the Eastern Cape Province of South Africa. The wastewater samples were aseptically screened for the presence of presumptive Plesiomonas shigelloides and selected Vibrio species using the culture-based method. The identity of the presumptive Plesiomonas shigelloides and Vibrio species (Vibrio cholerae, V. fluvialis, V. parahaemolyticus, and V. vulnificus) isolates were confirmed using species specific primers. After that, the presence 14 of virulence determinants and the antimicrobial susceptibility profiles of the positive strains as well as the antimicrobial resistance factors were all determined. The distribution of the presumptive isolates was as follows; 322 Plesiomans shigelloides and 378 Vibrio species respectively. However, upon molecular confirmation studies, 85 out of 322; 26% of the total presumptive isolates, were confirmed as positive for Plesiomans shigelloides and, on the other hand, from the 378 presumptive Vibrio species, 71% (270) was as positive to Vibrio genus, and upon speciation of the positive isolates; 27% (73) was confirmed as Vibrio cholerae, 9% (24) as Vibrio parahaemolyticus, 4% (12) as Vibrio vulnificus and 3% (8) as Vibrio fluvialis. The remaining 57% (153) which was unaccounted for may belong to other Vibrio species not included in this studies. Various virulence determinants were shown to be present in the Vibrio species identified and the degree varied in line with the species. P. shigelloides showed high levels of resistance to impregnated antibiotics (18 different types). The antibiogram characteristics showed P. shigelloides to possess 100% resistance to Ciprofloxacin, Nalidixic acid, Trimethoprim, Ampicillin, Penicillin, Tetracycline, Doxycycline, Erythromycin, and Cephalothin. These findings are of crucial importance to public health and the science of infectology as it gives insight into the role of the hospital wastewater as a puddle for the recombination of antibiotic resistance determinants and virulence emergence in bacteria. On the strength of the finding of this research, it is essential to indicate that there is a need for an immediate review of hospital wastewater disposal process. Some form of treatment or pretreatment of the hospital wastewater is required before discharge into municipal wastewater treatment facilities. And, perhaps, continuous monitoring of hospital wastewater to reduce the risk posed to public health.
- Full Text:
- Date Issued: 2018
Distribution of virulence determinants in some members of the ESKAPE pathogens isolated from selected hospital wastewater effluents in the Eastern Cape, South Africa
- Authors: Mapipa, Qaqamba
- Date: 2019
- Subjects: Effluent quality Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14704 , vital:40061
- Description: Members of ESKAPE pathogens are grouped under the acronymn made up of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens, isolated from hospitals and communities, have just been characterized for new pathogenesis and transmission patterns and overcoming the usefulness of available drugs, this leads to infections that tend to increase the rate of disease in a population and death rate and cost our society massively. The distribution of virulence determinants and the antibiotic susceptibility patterns in some members of the ESKAPE pathogens isolated from hospital wastewater facilities that were selected within the Eastern Cape Province, South Africa was evaluated. Water samples from the hospital wastewater facilities were collected fortnightly over a period of three (3) months (February to April). Spread plate technique was employed for the enumeration and isolation of the members of ESKAPE pathogens. A total of 725 presumptive ESKAPE isolates were collected, screened and Polymerase Chain Reaction (PCR) amplification of target determinants was performed. Results showed that Klebsiella pneumoniae tested positive for ninety two (92=35.9%) samples, Enterobacter cloacae fifty seven (57=22.2%) samples tested positive, Pseudomonas aeruginosa fifty four (54=21.09%) isolates tested positive and fifty three (53=20.7%) isolates tested positive for Acinetobacter baumannii making a total of 256 isolates which tested positive for some members of ESKAPE pathogens. The detection of some members of the ESKAPE pathogens in these Hospitals is a cause of concern to public health. A total of 256 ESKAPE isolates that were obtained from the hospital wastewater facilities; were subjected to antibiotic susceptibility test in order to determine their antibiotic-resistant profiles. ESKAPE isolates recovered from the three hospital effluents showing resistance to antimicrobial agents in this study were further evaluated for resistance determinants namely, sulfonamides resistance determinants (sulI and sulII), β-lactams (ampC, blaTEM and blaZ), tetracyclines (tetA, tetB, tetC and tetM), 10 chloramphenicol’s (catI and catII) and aminoglycoside resistance determinants (aacC2, apHAI and apHAII). The resistant determinants targeted have been evaluated through their prevalence and the following distributions were obtained: [β-Lactams; ampC (80%), blaTEM (77%)]; [Tetracyclines; tetA (87%)]; [Sulfonamides; sulI (79%)]; [Aminoglycosides; aacC2 (12%), aphA2 (52%) and aadA (18%)]. With the worldwide increase in these resistant occurrences, the execution of strict infection control policies and treatment with different antimicrobials needs hasty detection. Comprehensive data are therefore needed so that the history of infection, identification of genes present in organisms and monitoring of changes in infection patterns can be traced correctly.
- Full Text:
- Date Issued: 2019
Diversity and distribution of lepidopteran stem borers and their wild host plants in Western Cape and KwaZulu-Natal provinces, South Africa
- Authors: Kokwana, Bongiwe
- Date: 2016
- Subjects: Stem borers--South Africa Pests--South Africa Grain--Diseases--South Africa
- Language: English
- Type: Thesis , Masters , Entomology
- Identifier: http://hdl.handle.net/10353/11729 , vital:39101
- Description: Lepidopteran stem borers are infamous among cereal crops and sugarcane growers because of their pests status in these crops. Lepidopteran stem borers often infest cereal crops such as maize (Zea mays L.), sorghum (Sorghum bicolor L.), pearl millet (Pennisetum glaucum L.), sugarcane (Saccharum spp.). However, in natural habitats, the stem borers feed on a wide variety of wild host plants species in the Poaceae, Cyperaceae and Typhaceae families. Some wild host plants in close approximation of cultivated fields act as reservoirs for stem borers during the absence of cultivated crops. Understanding of the diversity of the stem borers, their host plants and their interactions was very important in development of management strategies for the stem borer populations. For an example, grasses such as Napier grass (Pennisetum purpureum Schumach.) and Sudan grass(Sorghum vulgare var. Sudanense (Piper) Hitchc.) act as trap plants whereas other grasses such as Molasses grass (Melinis minutiflora P. Beauv.) and legume silverleaf (Desmodium uncinatum (Jacq.) DC.) act as repellents to stem borer moths. In South Africa, studies on the diversity and distribution of lepidopteran stem borers in wild habitats are limited. Previous studies concentrated on diversity, abundance, and distribution of stem borers and their natural enemies on cultivated crops because of the economic importance of cultivated crops. In view of the foregoing, this study was conducted to investigate the diversity and distribution of lepidopteran stem borers and their host plants in wild habitats in the Western Cape and KwaZulu-Natal Provinces of South Africa and to generate mtDNA COI sequences of the stem borer species in natural habitats. These sequences can be accessed in databases and assist in identification of previously unknown stem borers in cultivated crops. Therefore this study contributes to development of monitoring and early identification tool of the stem borer movements between host plants assemblages. Surveys were conducted in Western Cape and KwaZulu-Natal provinces, South Africa during the rainy season of 2014 and 2015 in 38 localities to catalogue the diversity of lepidopteran stem borers in wild host plants. The sites visited belonged to five vegetation types: grassland, the Indian Ocean coastal belt, savanna, forest, and wetlands. A total of 237 lepidopteran stem borers was collected during study yielding 21 species that belonged to Noctuidae (Acrapex sp. 89, Acrapex sp. 90, Acrapex sp. 92, Acrapex sp., Acrapex minima, New genus NG11), Sesamia calamistis Hampson, Sesamia sp., Sesamia natalensis Le rü sp. nov., Sesamia nov sp. 4, Sesamia nov sp.36, Conicofrontia bipartita Hampson, Conicofrontia sesamoides Hampson, Conicofrontia diamensa Hampson, Pirateolea piscator Fletcher , Sciomesa mesophaea Aurivillius), Crambidae(Chilo partellus Swinhoe and Calamotropha paludella Hibner) Pyralidae (Phycitiinae sp. 1 and Phycitiinae sp. 2) and Tortricidae were recorded from 20 wild host plant species. Stem borer wild host plants species were Cymbopogon dieterlenii Stapf ex Schweick.,Cymbopogon nardus (L.) Rendle, Cymbopogon pospischilii (K. Schum.) C.E. Hubb., Digitaria macroglossa Henrad, Eriochloa meyeriana (Nees) Pilg.,Eriochloa fatmensis (Hochst. &Steud.) Clayton, Imperata cylindrica (L.) Raeusch., Miscanthus capensis (Nees) Andersson, Paspalum urvillei Steud., Panicum maximumJacq., Pennisetum purpureum Schumach., Phragmites australis (Cav.) Trin. Ex Steud.,Rottboellia cochinchinensis (Lour.) Clayton, Setaria homonyma (Steud.) Chiov.,Sorghum arundinaceum (Desv.) Stapf.,Cyperus divesDelile, Cyperu sdistans Pursh, Cyperus fastigiatus Rottb., Cyperus sexangularis Nees and Typha latifolia (L.).The diversity of stem borer species varied among vegetation types, host plants, and altitude. Morphological identification of specimens from these surveys indicated a high diversity of stem borer species in the Noctuidae family, followed by Pyralidae, Crambidae, and Tortricidae respectively. Of all the stem borers collected in the two provinces, noctuid species were most abundant in all vegetation types from low to high altitudes representing 62.45percent, whereas pyralids, crambids, and tortricids made up 26.58percent, 9.28percent, and 1.69percent respectively. The diversity and distribution of stem borers were affected by latitude. KwaZulu-Natal had higher latitudes ranging between -28.37717˚ and -31.07800˚ and had higher diversity, distribution and the of stem borers host plants, while Western Cape Province had lower diversity and distribution at latitudes ranging between -34.00280˚ and -34.05343˚. Morphological identification of stem borers was complemented with the mtDNA cytochrome oxidase I gene (COI) to investigate evolutionary relationships between the stem borer species collected in this study. Of the 12 sequences searched from the databases and the Genebank only five sequences were identified to species level; UFH024 was identified as Sciomesa mesophaea, the other four were identified as Conicofrontia sesamoides, Conicofrontia bipartita; and the first ever record of Calamotropha paludella in South Africa and Pirateolea piscator. Five sequences; UFH026, UFH028, UFH029, UFH030, UFH032 were only identified to order.
- Full Text:
- Date Issued: 2016
Diversity, host plant range and ecology of Lepidoptera stem borers in South Africa
- Authors: Stemele, Mxolisi Arnold
- Date: 2019
- Subjects: Lepidoptera Host plants Stem borers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15409 , vital:40405
- Description: The biology and ecology of Lepidopteran pests stem borers has been extensively studied because of the economic importance of pest species such as Busseola fusca (Fuller) (Noctuidae), Sesamia calamistis (Hampson) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae), and Eldana saccharina (Walker) (Pyralidae). Knowledge relating to diversity, infestation dynamics, and host plant range is readily available. In natural vegetation, the variety of stem borers is higher than that found in agroecosystems. However, there is a paucity of South African studies that explain the observed differences in diversity between the two systems. Stem borers are also known to exhibit species-specific ecological requirements, which influence their distribution between African countries. South African biomes are classified based on vegetation structure and climate, which happens to be the most critical factors that affect the distribution of phytophagous insects. This makes biomes an excellent model to investigate diversity and distribution of stem borer species. In this study, we investigated diversity, distribution and species composition in four biomes. The results showed that diversity and distribution of the stem borers in natural vegetation was determined by host plant distribution. Stem borer diversity correlated with high diversity of host plants. Thirty-two stem borer species were collected from 27 host plants and another three from light traps. Widely distributed host plants supported a higher diversity of stem borers, which is consistent with the resource availability hypotheses. Non-metric dimensional scale unfolding revealed disparity in host plant preference and plant species composition between the various stem borer families (Kruskal’s Stress = 0.16). Tortricidae species and Sesamia typhae (Le rü) (Noctuidae) feed exclusively on hydrophytic Cyperaceae species. The majority of Noctuidae, Crambidae and Phycitidae species collected were oligophagous on terrestrial Poaceae, with a few polyphagous exceptions feeding on hydrophytic Cyperaceae and Typhaceae. Additionally, species composition of Poaceae host plants differed between 8 Crambidae and the Phycitidae species. Stem borer species composition between biomes revealed the presence of distinct host plants (2D stress = 0.09) and stem borer (2D stress = 0.13) communities. The stem borer abundance and diversity were strongly correlated (R2 = 0.64), but species diversity (R2 = - 0.95) and host plant diversity (R2 = - 0.85) were inversely correlated to altitude. Based on these results it was concluded that stem borer diversity and distribution in natural vegetation was influenced by host plant diversity and distribution as well as climate associated with altitudinal gradients. In the last two decades, four stem borer species previously known on wild host plants; Busseola segeta (Bowden), Busseola phaia (Bowden), Pirateolea piscator (Fletcher) and Conicofrontia sesamoides (Hampson) have invaded cultivated crops. These invasions remained undetected because of a shortage of surveys, habitat transformation and misidentifications. Misidentifications are common among stem borers due to the considerable resemblance between morphospecies. In this study, we assessed the capacity of the mitochondrial gene Cytochrome c oxidase (COI) to delineate closely related species to develop monitoring and early detection of invasive species and to assess migration patterns and gene flow between the populations. The results demonstrated that COI is an effective DNA marker for species delineation and assessment of intra- and interspecific genetic relationship. The K2P distances and phylogenetic tree defined boundaries between Noctuidae species with high resolution. No divergence distance was detected between intraspecific species, but for the congener species, divergence distance was 0.044%-0.111% with an average of 0.076%. The average interspecies K2P distance (0.57%) was 5-15 times higher than the congener species distances. Phylogenetic analysis revealed the presence of two clades. Busseola and Sesamia species were connected in a monophyletic clade with a strong (93%) bootstrap. The second monophyletic clade comprised of a cluster of Pirateolea, Acrapex and Conicofrontia species, and this was also supported with 9 a strong bootstrap (100%). The gene flow study revealed low levels of genetic differentiation between the populations of B. fusca collected from different maize producing areas in South Africa. This low genetic differentiation was consistent with high gene flow. The number of effective migrants between the populations was between 8 and 99 individuals per generation. These results indicate high connectivity between the populations.
- Full Text:
- Date Issued: 2019
Dynamic Mathematical Modeling in Chemical Reaction Networks
- Authors: Gurajena, Simba
- Date: 2018
- Subjects: Chemical reaction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11961 , vital:39122
- Description: Many students are familiar with the idea of ecological, financial modeling and modeling in other fields, but modeling in engineering fields is still an area to be looked at. In this discussion the researcher will deal with chemical reaction networks. This will cover areas in chemical reaction, interaction diagrams and the associated models. The discussion will also cover dynamic behaviour of reaction networks. The law of mass action and examples of simple networks will be dealt with. Differential equation models of biochemical and genetic systems are invariantly nonlinear, and as such numerical simulation is used to solve such models. The use of numerical simulation packages will be discussed and separation of timescale and model reduction will form part of the discussion.
- Full Text:
- Date Issued: 2018
Dynamic service orchestration in heterogeneous internet of things environments
- Authors: Chindenga, Edmore
- Date: 2016
- Subjects: Internet of things
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8001 , vital:31457
- Description: Internet of Things (IoT) presents a dynamic global revolution in the Internet where physical and virtual “things” will communicate and share information. As the number of devices increases, there is a need for a plug-and–interoperate approach of deploying “things” to the existing network with less or no human need for configuration. The plug-and-interoperate approach allows heterogeneous “things” to seamlessly interoperate, interact and exchange information and subsequently share services. Services are represented as functionalities that are offered by the “things”. Service orchestration provides an approach to integration and interoperability that decouples applications from each other, enhancing capabilities to centrally manage and monitor components. This work investigated requirements for semantic interoperability and exposed current challenges in IoT interoperability as a means of facilitating services orchestration in IoT. The research proposes a platform that allows heterogeneous devices to collaborate thereby enabling dynamic service orchestration. The platform provides a common framework for representing semantics allowing for a consistent information exchange format. The information is stored and presented in an ontology thereby preserving semantics and making the information comprehensible to machines allowing for automated addressing, tracking and discovery as well as information representation, storage, and exchange. Process mining techniques were used to discover service orchestrations. Process mining techniques enabled the analysis of runtime behavior of service orchestrations and the semantic breakdown of the service request and creation in real time. This enabled the research to draw observations that led to conclusions presented in this work. The research noted that the use of semantic technologies facilitates interoperability in heterogeneous devices and can be implemented as a means to bypass challenges presented by differences in IoT “things”.
- Full Text:
- Date Issued: 2016
Economic change in town and countryside in the former Transkei : land use, livelihoods and market linkages in Ngcobo, Eastern Cape, South Africa
- Authors: Nikelo, Nqaba Benedictor
- Date: 2018
- Subjects: Homelands (South Africa) Homelands (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/10768 , vital:35757
- Description: In 1913 in South Africa the natives of land act during apartheid resulted to the separation of South Africa. South Africa was divided into two areas where they were black and white areas. This act had a rule that said the black people can only move out of their lands only if employed as labourers by the whites. The white population was one-fifth of the population and was given 92.5 percent of the land while the rest of the population were blacks and they were restricted to stay on the 7.5 percent of land. In the Eastern Cape, two homelands were created: the Transkei (in 1951) and the Ciskei (in 1961). In 1963 the Transkei became the first homeland to be granted the status of 'self-governing territory within the Republic of South Africa’, with the Ciskei following suit in 1972. The apartheid policies caused economic failure and corruption because very little economic and infrastructural development took place in the homelands. According to the ‘legacy perspective’: the former homelands are historically-determined structural poverty traps. The objective of the study is to describe the extent and change of economic function/role of Ngcobo town and linkages with its surrounding villages. Availability or convenient sampling and random sampling techniques were used to collect primary data from farmers and surrounding villages. Descriptive statistics was used to profile farmers as well as the participants in the surrounding villages. Descriptive statistics was used to describe the change in the economy of Ngcobo town and the change in the economy of the surrounding rural areas. Households in the former homelands devote a large share of their total expenditure to food and beverages, and yet it would appear that a relatively small share of this food originates from these same rural areas. The point of departure of this report is the observation that rural areas are diverse, whereby some areas within the former homeland areas in particular exhibit signs of dynamism which are not understandable in terms of the ‘legacy perspective’.
- Full Text:
- Date Issued: 2018
Effect of dietary Mucuna pruriens seed meal on the serum lipid profile and bone quality traits of broiler chickens
- Authors: Hempe, Chumani
- Date: 2019
- Subjects: Legumes Lipoproteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17213 , vital:40866
- Description: This study aimed at evaluating the effects of heated Mucuna pruriens seed meal on the blood serum lipid profile and bone quality parameters of broiler chickens. A total of 120 day-old unsexed Cobb 500 broiler chicks were randomly allocated for the 4 treatment diets (T1, T2, T3 and T4) containing 0, 10, 15, and 20% heated Mucuna pruriens seed meal. The birds were reared on wood shaving floor pens for 35 days. Birds were humanely slaughtered by severing the jugular vein using a sharp knife. Blood was collected into a tube, centrifuge and analyzed for a lipid profile analysis (total cholesterol (TC), high density lipoproteins (HDL), low density lipoproteins (LDL), triglycerides (TCD) as well as aspartate transaminase (AST) and alanine transaminase (ALT)) by enzymatic diagnostic kits (Diasys diagnostic kits). Both drumsticks severed using a sharp knife. After boiling in the water at 100°C for 10 mins the tibia bones were taken, air-dried for 96 hrs at room temperature and measured for weights. Bone length, strength, moisture and ash content as well as morphology were measured. The blood lipid profile of birds fed T1 was high (P < 0.05) for all the parameters measured, while T3 had the lowest (P < 0.05) profile. T2 and T4 had the same profile. ALT was found to be highest (P < 0.05) for T4 (5.27 ± 0.207/L) and lowest (P < 0.05) for T2 (4.67 ± 0.333/L) while AST was highest (P < 0.05) for T2 (320.13 ± 28.851/L) and lowest (P < 0.05) for T3 (208.47 ± 10.059/L). Treatment diet 3 (T3) was observed decreased bone quality among all diets; with the lowest (P < 0.05) bone strength (188.55 ± 12.039N), bone length (8.59 ± 0.131cm) and morphology (1.69 ± 0.058). Mucuna pruriens seed meal inclusion in broiler diets reduces blood serum lipids and 20% inclusion levels have no adverse effects on the bone quality attributes
- Full Text:
- Date Issued: 2019
Effect of different fat levels and Moringa oleifera leaf meal (MOLM) inclusion on proximate composition, fatty acid profile, lipid oxidation, and sensory attributes of chicken droëwors
- Authors: Tembela, Nelisiwe
- Date: 2020-11
- Subjects: Moringa oleifera , Meat--Quality , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20893 , vital:46709
- Description: The objective of the study was to determine the effect of different fat levels and Moringa oleifera leaf meal (MLM) inclusion on sensory attributes (aroma, meat flavour, spicy flavour, texture, colour, and saltiness), lipid oxidation, proximate composition, and fatty acid (FA) profile of chicken droëwors. Firstly, sensory attributes of chicken droëwors with different levels of fat and that of Moringa oleifera leaf meal were determined. In the second experiment, the effect of different fat and MLM inclusion levels on lipid oxidation during drying and storage, proximate composition, and fatty acid profile were also determined. A forty randomly selected consumers of different gender and age were used as the sensory panel. 75 percent of lean chicken meat and 25 percent of chicken fat was used during droëwors preparation. Thereafter, 9 treatments of chicken droëwors were produced, with MLM included either at 0 percent, 0.25 percent, 0.5 percent, and fat included at 10 percent and 15 percent. For fatty acid profile, the total lipid from dry sausage of all treatments was quantitatively extracted using chloroform and methanol in a ratio of 2:1. Lipid oxidation was measured by analyzing thiobarbituric acid reactive substances (TBARS) at intervals during drying (0, 0.25, 0.5, 72h) and after 7 days of storage under ambient conditions. The results showed that consumers like the chicken droëwors when 0.5 percent MLM added to the product. The inclusion of MLM in chicken droëwors had a positive effect on consumer sensory. The results of the study demonstrated that chicken droëwors contained a significantly higher percentage (P<0.05) of C18:1c9 (Oleic) (30.95 to 32.65 percent) acid than other fatty acids. Polyunsaturated fatty acids (PUFAs) were all non-significant (P˃0.05) except for Docosahexanoic, which was observed to be significant (P˂ 0.05) in all treatments except T1. There was no significance (P> 0.05) in mono-unsaturated fatty acids (MUFAs), except for Elaidic, vaccenic, linoleic, y-linoleic, erucic, and arachidonic. Lipid oxidation occurred more rapidly (P<0.05) when MLM was not added. During processing and storage, TBARS were higher (P< 0.05) in chicken droewors. TBARS during storage were lower (P>0.05) with MLM added. Results showed a significant difference (P<0.05) in proximate composition of chicken droëwors, containing on average 16.93±1.29 to 10.79± 1.83/ 100 g moisture, 45.80± 1.65 to 67.56± 2.33/ 100 g protein, 14.37± 2.15 to 26.13± 2.15/100 g ash. The current study resultsgave a summary of the composition of chicken droëwors and showed higher susceptibility to lipid oxidation in chicken droewors. Therefore, Moringa oleifera leaf powder showed antioxidant activity in chicken droëwors, reserved lipid oxidation in the product. In conclusion, MLM could be used as a functional antioxidant preservative in chicken droëwors. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
Effect of fire frequency on the recovery of soil invertebrate communities in semi-arid savanna biome of the Eastern Cape, South Africa
- Authors: Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Date: 2021-04
- Subjects: Soil invertebrates , Fire ecology , Arid regions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22831 , vital:52946
- Description: Fires are common in South African savanna habitats, which can disrupt the dynamics of entire invertebrate populations, endangering biodiversity and the environment. The aim of this study was to look at how fire frequency affected invertebrate population dynamics and biodiversity in a 41-year-old fire experiment at the University of Fort Hare research farm in Alice. The experiment had six different levels of burning frequency: no-burn (K), annual burn (B1), biannual burn (B2), triennial burn (B3), quadrennial burn (B4), and sexennial burn (B6). The experimental plots were replicated two times in a randomized complete block design and have been continuously retained since 1980. A ground yellow mustard solution was used to collect earthworms, which were then identified by an earthworm taxonomist. Pitfall traps were used to collect ants and other insects, which were then identified under a microscope. In total, three soil samples were collected from each plot to assess selected soil nutrients, moisture, and pH. The Shannon diversity index, richness, and population of earthworms, ants, and other insects were calculated, and a one-way ANOVA analysis was done to check if the treatments differed significantly. A correlations study was used to look for any influence connected to soil parameters, including the Shannon diversity index, species richness, and density of soil invertebrates. According to our findings, the measured parameters did not show any significant differences in the measured parameters between the different frequency levels. All the plots had two species of earthworm , Proandricus timmianus and Proandricus beddardi except the biennial burn plot, which had all three, the afore mentioned species and one other unidentified species, Proandricus sp. The triennial burn treatment slightly enhanced the insect diversity, richness, and evenness of ant species difference while the diversity, evenness, and richness were lowest in the sexennial burn plot. However, there was no signif difference in population. After B4, the no burn plot had the second largest diversity and species richness, and the third highest species evenness and had a 100 percent species similarity index. The ants were evenly distributed in the no burn plot compared to the other plots, with K having a lower density than the other plots except for B4, K being slightly more diverse than B6, and B1 with a slightly lower diversity than the other plots, and it being the third species rich plot after B2 and B3, followed by the rest of the plots. This study implied that fire frequency has an insignificant impact on invertebrates’ communities in Savanna biomes words.icant , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04