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The effects of habitat, season, and ungulate carcass sites on the chiropteran assemblage of Telperion Nature Reserve, South Africa
Get PDFGlobally, insectivorous bats provide ecosystem services including pest suppression and nutrient cycling that are vital for maintaining ecosystem function and agricultural health and productivity. Sixty-two of the 67 documented South African bat species are insectivorous. Insectivorous bats form an essential component of most, if not all southern African ecosystems. Grasslands cover approximately 28.6 % of South Africa’s land area, yet the associated bat biodiversity is understudied relative to other habitats; it is reported that bat diversity may be greatest in the wetter eastern parts of the country, particularly in savanna, woodland and natural forested habitat. Telperion Nature Reserve Telperion Nature Reserve is a grassland-dominated reserve straddling the border between the Mpumalanga and Gauteng provinces of South Africa, and the grassland and savanna biomes. Using data collected by physical capture and acoustic monitoring, an insectivorous bat species inventory for Telperion Nature Reserve was compiled and a regional echolocation call library was developed. The singular and combined effects of habitat, season and bioclimatic variables on species richness, diversity, abundance, functional diversity, and relative activity of the Telperion Nature Reserve bat assemblage was assessed. Additionally, the effect of the presence of blue wildebeest (Connochaetes taurinus) carcasses on bat activity was also investigated, using passive (acoustic) sampling. Bats identified on Telperion Nature Reserve were allocated to five functional groups based on morphological, ecological and behavioural traits. In total, 22 species from seven families were identified. This study developed a call library for insectivorous bats in this grassland system and provides a comprehensive baseline for future studies. A cryptic Rhinolophus cf. simulator species was recorded with characteristic frequency (Fc) of 79 kHz, significantly different to that of Rhinolophus simulator s.s. (~83 kHz Fc). It corroborated previous findings of sex-related echolocation call parameter variances in vespertilionid species. Habitat and season are important determinants of bat occupancy, relative abundance and activity. Bat activity varied significantly between habitat types. Watercourses were associated with the highest bat species diversity. Anthropogenic sites were associated with the highest levels of bat activity. This study demonstrates the value of watercourses and anthropogenic sites, for bats, within the relative homogeneity of grassland systems. The maintenance and conservation of watercourses in this area will enhance the conservation value of Telperion Nature Reserve for bats. Insectivorous bat activity on Telperion Nature Reserve varied significantly on a seasonal basis, with the lowest diversity and activity recorded in winter. Both bat passes and feeding buzzes were recorded over carcass sites suggesting that bats forage over such sites. Caged carcass sites exhibited elevated bat activity levels, however this result was not significant. This study should be repeated with greater sampling effort and more constrained site selection parameters to avoid potential sampling biases that may skew the data (i.e. a high intra-treatment variation). This study illustrates the importance of grasslands, even those that fall within a modified matrix, for bat ecology and conservation.M. Sc. (Nature Conservation)Agriculture, Animal Health and Human Ecolog
Fake news and the political economy of the media in Ghana : the era of the Fourth Industrial Revolution
Get PDFThis study investigates fake news and the political economy of the media in Ghana in the interplay of convergence of technology in the era of the fourth industrial revolution. It adopts the exploratory sequential mixed-method approach that is anchored on the critical realism philosophical foundations. This ensured that triangulated data were collected using in-depth interviews and questionnaire in obtaining empirical data. With a qualitative sample of five news editors and a sample of 230 journalists for the quantitative, the mixed study had a total sample size of 235 journalists, all based in the Greater Accra region, the capital city of Ghana. The study which makes significant contributions to existing literature on fake news and political economy of the media, exposes a number of intriguing issues on the subject and could contribute in curbing the phenomenon of fake news in the mainstream and social media sphere. Findings confirm the hypothesis that economic and political reasons are responsible for the production and dissemination of fake news in the country. This is aided by the fourth industrial revolution technologies making fabricated content to easily disseminate. The study discovered that fake news spread exponentially during the 2020 elections and at the peak of Covid-19 in Ghana. This is done in blatant disregard to laid down ethical procedures in journalism and existing laws that frown on fake news in the country. The study acknowledges the critical role ethical journalism plays as a self-regulatory mechanism in checking excessive dissemination of fake news amidst policy constraints in fighting the technological weaponisation, with its concomitant effects on the country’s fragile democracy. Respondents expressed frustration as journalists who want to remain relevant as they battle untrustworthy information spread in social and mainstream media. The study suggests the need for Government to balance the need of legislating fake news and the rights of people to freely express themselves. It also calls on the government to take rightful decisions at mitigating the increasing threats of fake news camouflaged in propaganda spins.D. Phil.Communication Scienc
Kurrikulumstudies in konteks 2
No full textSlegs bibliografiese inligting oor die boek is beskikbaar in die UnisaIR.Curriculum and Instructional Studie
Metabolomic analysis of GM and non-GM maize and its preference by cattle
No full textGM organisms have started to infiltrate South Africa's agricultural landscape, altering how
farmers deal with weeds and insects. Adopted from the United States of America, it is a
technology that the commercial farming sector cannot do without anymore and the uptake
was enormous in the last 10 years. The technology involves altering the DNA of an
organism to provide a specific benefit using genetic engineering techniques.
But all new technologies and inventions bring the responsibility of stewardship and
accountability with it, and it is impossible to predict all possible outcomes of such an
invention to every possible scenario in terms of environmental stewardship. The question
and occurrence of cattle and wild animals seemingly choosing non-GM containing maize
plants have raised the question whether this is really the case of the presence of the GM or
maybe it is just due to the differences in plant genetic makeup. Quicker deterioration of
short, seasoned cultivars opposed to the longer seasoned cultivar that is known to be more
resistant to diseases and plant pathogens, might therefore not be as easily affected by mainly
pathogens and stay much tastier for longer.
This study used beef cattle of the Drakensberger indigenous breed to determine the taste
preference with the use of a trial that is planted with the different types of maize cultivars
that includes GM and non-GM maize and short and longer seasoned cultivars. The trial was
performed on a commercial farm near Standerton, Mpumalanga in the high rainfall area of
South Africa. The results clearly indicated that cattle could not differentiate the GM maize
from the non-GM maize, but that they preferred the longer season cultivar.
The chemical profiles of different materials, including those made from GM and non-GM,
were analyzed using NMR spectroscopy and OPLS-DA and pre-processing techniques. The
results of the metabolomic study revealed that the former had slightly different
metabolomics profiles than the latter. The differences were mainly concentrated in the
aliphatic and sugar regions. On the other hand, the long and short-season GM had similar
metabolomic profiles.
The study therefore clearly indicates that cattle could not differentiate GM from non-GM
material on taste and that any material can be provided to cattle. The slight difference in the
metabolomics profiles however raise a concern for differential metabolomic pathways and
should be investigated further.M. Sc. (Agriculture)Agriculture and Animal Healt
Next generation sequencing as a genomic used tool to detect species substitution and mislabelling in meat products sold in South Africa
Get PDFMeat species adulteration is a subject that has brought a lot of controversy to the meat industry and has led to meat adulteration studies being conducted worldwide. Correct labelling of meat products promotes fair trade and ensure that consumers make well informed decisions when choosing the meat they want to consume. Unfortunately, the unabated increase in the cost of resources has resulted in an increase in meat species substitution and/or mislabeling in the global meat industry. Deoxyribonucleic acid-based methods have previously been used in the past for species identification, however, they are limited to a few targeted species. Next Generation Sequencing is a universal technology that can be used to identify meat species. The main objective of this study was to evaluate genomics and bioinformatics pipelines that will facilitate utilization of genetic markers and Next Generation Sequencing (NGS) technology to identify and discriminate meat species in the South African meat industry.
The first study investigated the discriminatory potential of 16S rRNA, 12S rRNA, COX3 and ATP6 mitochondrial genes in mammalian species identification and differentiation. To achieve this, a phylogenetic analysis was conducted using the entire database of 262 mammalian species for each of the above genes downloaded from Genbank (http://www.ncbi.nlm.nih.gov/nuccore). All four genes managed to separate distantly related species and group closely related species with a common ancestry, however, the ATP6 and COX3 genes grouped some species that were not closely related together. Overall, the 16S rRNA gene performed the best with bootstrap values of 97 – 100% in all clades observed whilst the ATP6 gene performed the least. There was no improvement in performance when the 12S rRNA, COX3 and ATP6 genes were individually combined with the 16S rRNA gene. There were high bootstrap values of 100% observed in most clade groupings when all four genes were combined. Consequently, the study recommends the use of the 16S rRNA gene on its own for species identification, as it performed well in comparison to the 12S rRNA, COX3 and ATP6 genes. The use of four different genes in a species identification experiment will be more expensive and time consuming albeit yielding relatively higher bootstrap values.
The second experiment developed a molecular and bioinformatics diagnostic pipeline that utilizes the mitochondrial 16S ribosomal RNA (rRNA) barcoding gene, to determine processed meat product mislabelling through Next Generation Sequencing. Pure meat samples were artificially mixed at different ratios, to verify the sensitivity and specificity of the pipeline. Processed meat samples (n = 155) namely, minced meat (n = 49), biltong (n = 28), burger patties (n = 35), and sausages (n = 43) were collected from across South Africa and sequenced using the Illumina MiSeq sequencing platform. All the species used in the artificially mixed pure samples were identified, confirming the specificity and sensitivity of the pipeline. Processed meat samples had reads that mostly mapped to the Bos (90% and above) genus, with traces of the Ovis and Sus (2 – 5%) genus. This confirmed that the majority of the processed meat samples were from beef. Amongst all processed meat samples, sausages had the highest level of contamination, with 46% of the samples having mixtures of beef, pork or mutton in one sample, which was in contrast to the labelling, as the only labelling provided was of samples labelled as beef sausages. The pipeline further demonstrated its specificity by identifying species with percentages as low as 0,1% in both the artificially mixed pure samples and processed meat samples. Overall, the developed pipeline can be used with confidence to authenticate meat products and furthermore, investigate and manage any form of mislabelling in the meat industry.
The third and last experiment investigated the presence of breed-specific Single Nucleotide Polymorphisms (SNPs) using the entire mitochondrial genome of 13 European and Indigenous cattle breeds reared in South Africa for use in breed assignment and traceability. Whole genome sequencing was performed on 13 European and Indigenous cattle breeds reared in South Africa. A total of 42 animals were used from Afrikaner (n = 4), Beefmaster (n = 4), Boran (n = 4) Charolais (n = 2), Hereford (n = 2), Nguni (n = 2), Simbra (n = 3), Bonsmara (n = 4), Brahman (n = 4), Drakensberger (n = 4), Limousin (n = 2), Santa (n = 3) and Simmentaler (n = 4) breeds. Whole genome sequencing was performed using the Illumina HiSeq 2500 (Illumina, San Diego, CA, United States) at 10X coverage. A total of 12 996 variants were identified and of these 12 633 were SNPs and 363 were Indels. The highest number of variants were identified in the European Brahman breed (n = 2 066) and the lowest in the Indigenous Nguni breed (n = 340). The SNPs were also divided into homozygous and heterozygous SNPs. The highest number of homozygous
SNPs were found in the Limousin breed (n = 534) and the highest number of heterozygous SNPs were found in the Brahman breed (n = 1 872). To identify breed-specific SNPs we used all homozygous SNPs identified that have the same alleles. A total of 125 breed-specific SNPs were identified in all breeds except for the Charolais breed that did not contain any breed-specific SNPs. The Limousin breed had the highest number of breed specific SNPs (n = 59) and the lowest were found in the Nguni breed (n = 1). The COX3 mitochondrial gene had the highest number of breed specific SNPs (n = 22), followed by the 16S mitochondrial gene (n = 19). Nineteen of the breed-specific SNPs were shared amongst breeds and the ND5 gene contained the highest number of shared SNPs. This study provides an insight on the presence of SNPs within the mitochondrial genome of cattle breeds reared in South Africa. The breed specific SNPs identified provided an understanding of the regions within mitochondrial genes that are unique in each breed and can be used in the authentication of beef meat in the meat industry.
In conclusion the study illustrated that NGS can be used as a genomic tool to detect meat species mislabelling in meat products in South Africa and worldwide. Mitochondrial sequences were used to determine the discriminatory potential of four genes (16S rRNA, 12S rRNA, COX3 and ATP6) in mammalian species. The 16S rRNA gene demonstrated the highest discriminatory potential amongst the four genes. Using the 16S rRNA gene, NGS technology was further used to identify meat species in both artificially mixed pure and processed meat samples. The NGS technology proved that it can be used as a universal tool in meat species identification. Finally, using NGS cattle breeds reared in South Africa were sequenced and the sequences were used to identify breed specific SNPs in the mitochondrial genome of the cattle breeds. The mitochondrial genes that contained the most breed-specific SNPs were within the ND5, COX3 and 16S rRNA genes.Ph.D. (Life Sciences)Life and Consumer Science
A geo-informatics approach to sustainability assessments of floatovoltaic technology in South African agricultural applications
Get PDFSouth African project engineers recently pioneered the first agricultural floating solar photovoltaic tech nology systems in the Western Cape wine region. This effort prepared our country for an imminent large scale diffusion of this exciting new climate solver technology. However, hydro-embedded photovoltaic sys tems interact with environmentally sensitive underlying aquatic ecosystems, causing multiple project as sessment uncertainties (energy, land, air, water) compared to ground-mounted photovoltaics. The dissimi lar behaviour of floatovoltaic technologies delivers a broader and more diversified range of technical advan tages, environmental offset benefits, and economic co-benefits, causing analytical modelling imperfections
and tooling mismatches in conventional analytical project assessment techniques. As a universal interna tional real-world problem of significance, the literature review identified critical knowledge and methodology
gaps as the primary causes of modelling deficiencies and assessment uncertainties. By following a design thinking methodology, the thesis views the sustainability assessment and modelling problem through a geo graphical information systems lens, thus seeing an academic research opportunity to fill critical knowledge
gaps through new theory formulation and geographical knowledge creation. To this end, this philosophi cal investigation proposes a novel object-oriented systems-thinking and climate modelling methodology to
study the real-world geospatial behaviour of functioning floatovoltaic systems from a dynamical system thinking perspective. As an empirical feedback-driven object-process methodology, it inspired the thesis to
create new knowledge by postulating a new multi-disciplinary sustainability theory to holistically characterise
agricultural floatovoltaic projects through ecosystems-based quantitative sustainability profiling criteria. The
study breaks new ground at the frontiers of energy geo-informatics by conceptualising a holistic theoretical
framework designed for the theoretical characterisation of floatovoltaic technology ecosystem operations
in terms of the technical energy, environmental and economic (3E) domain responses. It campaigns for a
fully coupled model in ensemble analysis that advances the state-of-the-art by appropriating the 3E theo retical framework as underpinning computer program logic blueprint to synthesise the posited theory in a
digital twin simulation. Driven by real-world geo-sensor data, this geospatial digital twin can mimic the geo dynamical behaviour of floatovoltaics through discrete-time computer simulations in real-time and lifetime
digital project enactment exercises. The results show that the theoretical 3E framing enables project due
diligence and environmental impact assessment reporting as it uniquely incorporates balanced scorecard
performance metrics, such as the water-energy-land-food resource impacts, environmental offset benefits
and financial feasibility of floatovoltaics. Embedded in a geoinformatics decision-support platform, the 3E
theory, framework and model enable numerical project decision-supporting through an analytical hierarchy
process. The experimental results obtained with the digital twin model and decision support system show
that the desktop-based parametric floatovoltaic synthesis toolset can uniquely characterise the broad and
diverse spectrum of performance benefits of floatovoltaics in a 3E sustainability profile. The model uniquely
predicts important impact aspects of the technology’s land, air and water preservation qualities, quantifying
these impacts in terms of the water, energy, land and food nexus parameters. The proposed GIS model
can quantitatively predict most FPV technology unknowns, thus solving a contemporary real-world prob lem that currently jeopardises floating PV project licensing and approvals. Overall, the posited theoretical
framework, methodology model, and reported results provide an improved understanding of floating PV renewable energy systems and their real-world behaviour. Amidst a rapidly growing international interest in
floatovoltaic solutions, the research advances fresh philosophical ideas with novel theoretical principles that
may have far-reaching implications for developing electronic, photovoltaic performance models worldwide.Ph. D. (Geography)Geograph
Optimization of Cr (VI) removal from aqueous solution with activated carbon derived from Eichhornia crassipes under response surface methodology
No full textTannery industries’ effluent contains a high concentration of Cr (VI) which has the potential to affect the environment and public health. Therefore, this study aimed to investigate the optimization of Cr (VI) adsorption by activated carbon (AC) derived from Eichhornia crassipes from an aqueous solution. The adsorbent was activated with dilute sulfuric acid followed by thermal activation. AC was characterized using proximate analysis, SEM, FTIR, X-ray diffraction, and the BET method. The Cr (VI) removal optimization process was performed using a central composite design under the response surface methodology. The proximate analysis showed that the moisture content, volatile matter, ash content, and fixed carbon of the activated carbon were 5.6%, 18.2%, 14.4%, and 61.8% respectively. The surface areas of the Eichhornia crassipes before activation, after activation, and after adsorption were 60.6 g/m2, 794.2 g/m2, and 412.6 g/m2 respectively. A highly porous structure with heterogeneous and irregular shapes was observed in the SEM micrograph. In the FTIR analysis, different peaks are indicated with various functional groups. The intensity of XRD peaks decreased as 2 theta values increased, which indicates the presence of an amorphous carbon arrangement. The point of zero charge (pHpzc) of the activated carbon was found to be 5.20. A maximum Cr (VI) removal of 98.4% was achieved at pH 5, contact time 90 min, adsorbent dose 2 g, and initial Cr (VI) concentration of 2.25 mg/L. Statistically significant interactions (P < 0.05) were observed between the initial Cr (VI) concentration and adsorbent dose as well as the initial Cr (VI) concentration and contact time. Langmuir adsorption isotherm fitted the experimental data best, with an R2 value of 0.99. The separation constant (RL) indicates that the adsorption process is favorable. The kinetic experimental data were best fitted with the pseudo-second-order model with an R2 value of 0.99 whereas the adsorption rate is controlled by intraparticle and extragranular diffusion processes. Generally, the AC has the potential to be a strong adsorbent candidate for wastewater treatment at the industrial level
A macroeconomic viewpoint using a structural VAR analysis of silver price behaviour
No full textThis article investigates silver price as a fluctuating commodity price since the financial crisis of 2007-2009. In this regard, a structural vector autoregression (VAR) was applied to observe the sensitivity of the silver price and future pricing due to changes in macroeconomic variables and to review changes in macroeconomic variables due to changes in the silver price. The main results show that the silver price is susceptible to changes in the gold price, increasing sideways. A shock to OECD GDP caused the silver price to increase which makes logical sense, thus showing a positive correlation between output and the silver price. A shock to the oil price caused the silver price to spike over the short term, then move sideways over the long term. A shock to the US Federal funds rate caused the silver price to dip over the short term, then increase slightly over the medium and move sideways over the long term, while a shock to the real effective exchange rate of the United States caused the silver price to increase sideways. The article sheds some light on the reactive status of the silver price to macroeconomic variables and its influence as a safe haven commodity.Economic
Strategies to prevent HIV infections among women in the Ditsobotla Municipality of the North West Province, South Africa
No full textThe status of the Human Immunodeficiency Virus (HIV) among women in South Africa is
worrisome. Imbalances in power relations between men and women subject women to
perpetual vulnerability to HIV infection whilst effective preventative interventions are
lacking. Whilst antiretrovirals (ARVs) are successful in treating HIV, they are not vaccines.
This study sought to identify new strategies that can be employed to prevent HIV
infections among women in the Ditsobotla Municipality, North West (NW) Province, South
Africa. This study applied the narrative research design. The study population comprised
Health officials, Social Development officials, councillors, CBO representatives and
Police officials residing in Ditsobotla Local Municipality. The researcher used a purposive
sampling method to identify key informants from the population sample. A sample of 22
participants contributed to the study. Semi-structured interviews were employed to collect
primary data from key informants using the ZOoom virtual platform. The study employed
content analysis, which involved coding and arranging the data into chunks of information
and categories. Setswana and English languages were used in this study. The results
showed five main factors fuelling the spread of HIV: violence against women, inconsistent
use of condoms and other prevention methods, abuse of alcohol and drug substances,
multiple sex partners, and misconceptions about HIV/AIDS. Whilst there are existing HIV
prevention interventions in Ditsobotla, such as condom distribution, small group
counselling known as "You Only Live Once" (YOLO), and post-exposure prophylaxis
(PrEP), their coverage remains sub-optimal, putting women at risk of HIV infection. The
study recommends creating an enabling environment for comprehensive HIV services for
women: enhancing the implementation of combination prevention interventions and an
integrated HIV services approach, including PrEP, condom promotion and male
involvement; optimising education for young girls; harnessing empowerment of women
as the cornerstone to changing the HIV epidemic; leveraging telehealth as the digital
information and communication technological solutions; leveraging the availability of an
integrated M&E framework.M. A. (Social and Behavioural Studies)Social Wor
Acting Strategically During Change: A Process and Dwelling World-view Approach
No full textambiguity and uncertainty. Responding to these changes requires
a dynamic approach with a wider set of skills and coping
mechanisms. In this article, we argue for a broad focus on change
that considers the tacit elements of strategising. We adopted a
dwelling worldview as well as a strong process ontology combined
with a practice perspective to capture the complexity and richness
of a strategic change process with a focus on identity and
legitimacy dynamics. This article reports on an emerging process
model of how individuals in non-managerial positions respond to
and make sense of planned strategic change. The study followed a
longitudinal, processual approach using a South African business
school as the research setting. The findings of the study contribute
towards a deepened understanding of the dynamics that occur
within strategic change processes, showing that strategising is a
dynamic process involving instinct, adjustment and phronetic
action. Understanding how individuals respond, adapt and cope
during strategic change processes provides potentially helpful
insight into how strategic change is enabled or constrained, which
could have future implications on how change processes are
designed or implemented.Business Managemen