African birds as army ant followers
- Authors: Craig, Adrian J F K
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448772 , vital:74759 , https://doi.org/10.1007/s10336-022-01987-0
- Description: Ant-following birds have been studied extensively in the Neotropics, but much less information is currently available for the Afrotropics. There are published records of 168 African bird species from 37 families foraging in association with driver ants (Dorylus, sub-family Dorylinae). However, of 52 bird species assessed as regular ant-followers, 38 belong to three families, which are disproportionately represented compared to other large Afrotropical bird families: Muscicapidae (18 spp.), Pycnonotidae (13 spp.) and Turdidae (7 spp.). The extent to which these birds are dependent on ants through their annual cycle is not known. African driver ants forage primarily under shaded, humid conditions by day, and may spend a month or longer underground. Conservation assessments of African forest habitats suggest that both driver ants and ant-following birds may be especially sensitive to the loss of forest cover.
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Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost
- Authors: Foster, Ryan M , Childs, Amber-Robyn , Mann, Bruce Q , Potts, Warren M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443128 , vital:74080 , https://doi.org/10.1080/15627020.2022.2035254
- Description: The South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern and eastern coasts of South Africa. Monthly biological samples were collected through research spearfishing (n = 170) and augmented by recreational spearfishers’ catches (n = 135). The results indicated that the O. conwayi population sex ratio was skewed towards males (1M:0.6F). The length- and age-frequency distributions were similar between sexes. Oplegnathus conwayi is a relatively slow-growing species, with a maximum-recorded age of 27 years. No significant differences were observed between male and female growth, with the overall population growth curve being best described as L(t) = 697.15(1 − e−0.06(t−6.30)). The slow growth observed in this species is characteristic of a species that is vulnerable to overexploitation, and accordingly a precautionary approach to future management is recommended.
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AMADAR: a python-based package for large scale prediction of Diels–Alder transition state geometries and IRC path analysis
- Authors: Isamura, Bienfait K , Lobb, Kevin A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453143 , vital:75226 , xlink:href="https://link.springer.com/article/10.1186/s13321-022-00618-3"
- Description: Predicting transition state geometries is one of the most challenging tasks in computational chemistry, which often requires expert-based knowledge and permanent human intervention. This short communication reports technical details and preliminary results of a python-based tool (AMADAR) designed to generate any Diels–Alder (DA) transition state geometry (TS) and analyze determined IRC paths in a (quasi-)automated fashion, given the product SMILES. Two modules of the package are devoted to performing, from IRC paths, reaction force analyses (RFA) and atomic (fragment) decompositions of the reaction force F and reaction force constant κ. The performance of the protocol has been assessed using a dataset of 2000 DA cycloadducts retrieved from the ZINC database. The sequential location of the corresponding TSs was achieved with a success rate of 95%. RFA plots confrmed the reaction force constant κ to be a good indicator of the (non)synchronicity of the associated DA reactions. Moreover, the atomic decomposition of κ allows for the rationalization of the (a)synchronicity of each DA reaction in terms of contributions stemming from pairs of interacting atoms. The source code of the AMADAR tool is available on GitHub [CMCDD/AMADAR(github. com)] and can be used directly with minor customizations, mostly regarding the local working environment of the user.
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Application of gold and palladium nanoparticles supported on polymelamine microspheres in the oxidation of 1-phenylethanol and some other phenyl substituted alcohols
- Authors: Storm, Ené , Maggott, Emile D , Mashazi, Philani N , Nyokong, Tebello , Malgas-Enus, Rehana , Mapolie, Selwyn F
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/299824 , vital:57858 , xlink:href="https://doi.org/10.1016/j.mcat.2022.112456"
- Description: Melamine formaldehyde and melamine resorcinol formaldehyde microspheres were decorated with Au and Pd nanoparticles and applied as heterogeneous catalysts in the oxidation of 1-phenylethanol. The catalysts showed similar activities irrespective of the support employed. Moderate conversion activities of 48–50% were achieved when using acetonitrile as solvent; however, when employing water as solvent, the supported catalysts formed a three-phase, emulsion system which facilitated the catalytic conversion of 1-phenylethanol to acetophenone at much higher conversions of around 83%. The oxidant, TBHP, decomposed rapidly in acetonitrile, whilst it remained stable in aqueous solution, leading to the enhanced activities observed when using water as solvent. These systems also proved to be recyclable for up to five cycles, with only slight loss of activity observed; this can be attributed to the physical loss of catalyst during the workup procedure conducted between each cycle.
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Aptamer versus antibody as probes for the impedimetric biosensor for human epidermal growth factor receptor
- Authors: Centane, Sixolile , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229884 , vital:49720 , xlink:href="https://doi.org/10.1016/j.jinorgbio.2022.111764"
- Description: In the present work, the performance of aptamer and antibody bioreceptors for the detection of the human epidermal growth factor receptor (HER2) cancer biomarker on a glassy carbon electrode is reported. The carboxylic acid group rich graphene quantum dots (GQDs) modified with gold nanoparticles and a porphyrin binuclear framework (CoP-BNF) were used to modify the glassy carbon electrode. The aptamer and antibody were both amine functionalized and attached to GQDs and CoP-BNF through an amide bond. The designed immunosensors and aptasensors in this work were characterized using electrochemical impedance spectroscopy. The aptasensors, compared to the immunosensors gave better limit of detection values. The aptasensor outperforms the immunosensor in terms of its reusability and storability, while the immunosensor could not be regenerated for subsequent experiments. The potential applicability of all sensors in this work was also investigated, by detection of HER2 in spiked human serum with acceptable results.
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Assessing climate risk to support urban forests in a changing climate
- Authors: Esperon-Rodriguez, Manuel , Rymer, Paul D , Power, Sally A , Barton, David N , Cariñanos, Paloma , Dobbs, Cynnamon , Eleuterio, Ana A , Escobedo, Francisco J , Hauer, Richard , Hermy, Martin , Jahani, Ali , Onyekwelu, Jonathan C , Östberg, Johan , Pataki, Diane , Randrup, Thomas B , Rasmussen, Tørres , Roman, Lara A , Russo, Alessio , Shackleton, Charlie M , Solfjeld, Ingjerd , van Doorn, Natalie S , Wells, Matthew J , Wiström, Björn , Yan, Pengbo , Yang, Jun , Tjoelker, Mark G
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/402191 , vital:69829 , xlink:href="https://doi.org/10.1002/ppp3.10240"
- Description: Globally, cities are planning for resilience through urban greening initiatives as governments understand the importance of urban forests in improving quality of life and mitigating climate change. However, the persistence of urban forests and the ecosystem benefits they provide are threatened by climate change, and systematic assessments of causes of tree dieback and mortality in urban environments are rare. Long-term monitoring studies and adaptive management are needed to identify and prevent climate change-driven failures and mortality. Research and monitoring when coupled with systematic forecasting will enable governments to incorporate climate change resilience into urban forestry planning. Future scenarios in which urban forests are resilient or in decline will depend on the management and planning actions we make today.
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Assessing the electrocatalytic activity of a localized push-pull system in cobalt phthalocyanine/graphene quantum dot hybrids
- Authors: Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229909 , vital:49722 , xlink:href="https://doi.org/10.1016/j.matchemphys.2022.125842"
- Description: In this study, two cobalt phthalocyanines (asymmetric complex 1) and symmetric (complex 2) were synthesized and conjugated to nitrogen-doped graphene quantum dots (NGQDs) through covalent and non-covalent means to create Co phthalocyanine (CoPc)-NGQDs hybrid systems. The CoPcs and conjugates were applied as electrode modifiers on a glassy carbon electrode in the electrochemical sensing of nitrite. Of the CoPcs alone, complex 1 performed better than complex 2 regarding the limits of detection (LoD) recorded (5.74 μM for 1 and 15.1 μM for 2). Regarding the conjugates/nanocomposites, the π-π stacked conjugate derived from complex 2 (2πNGQDs) demonstrated highly favourable electrochemical potential with an LoD value of 0.70 μM. The nanocomposites fashioned from complex 1 were marred by a reduced loading which rendered the conjugates poor electrochemical sensors. These observations however do not disqualify GQDs as complementary nanomaterials to phthalocyanines but rather shed light on seeking alternative routes to increasing the Pc loading in conjugates (more so in π-π stacked conjugates).
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Assessing the Impact of DNS Configuration on Low Bandwidth Networks
- Authors: Okuthe, J A , Terzoli, Alfredo
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430903 , vital:72726 , https://doi.org/10.1007/978-3-031-34896-9_6
- Description: Domain name system (DNS) is an essential enabler for connecting us-ers and services on the Internet. DNS translates human readable do-main names into IP addresses and precedes client connection to a server via a domain name. DNS service is therefore expected to con-sume network bandwidth even though it offers no direct benefit to the user. Having observed the large component of DNS traffic on the com-munity network local loop in our previous study, we migrated the DNS service from a server on the LAN to the gateway router and reconfig-ured the cache time-to-live. Results from the analysis of network traffic captured from the gateway router interface show a 26% decrease in the downlink bandwidth utilization and 46% decline in the uplink bandwidth utilization. The DNS component of the local loop traffic reduces from 45.28% to 4.11%. On the other hand, the Web component of the local loop traffic increases from 49.42% to 95.49%. Data collected from a mirroring port on the LAN switch indicate a decrease in the DNS portion of the internal traffic from 0.38% to 0.18%. Although the DNS reconfigu-ration helps alleviate network bandwidth constraints and reduces DNS component of the traffic, the Web portion increases. The implementa-tion of effective, efficient and sustainable Web traffic management is therefore required.
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Asymmetrical zinc (II) phthalocyanines conjugated to metal tungstate nanoparticles for photoinactivation of Staphylococcus aureus
- Authors: Mgidlana, Sithi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295718 , vital:57372 , xlink:href="https://doi.org/10.1080/00958972.2022.2090837"
- Description: In this study, we report for the first time on the photodynamic antimicrobial chemotherapy (PACT) of asymmetrical zinc(II) phthalocyanines and their conjugates with nickel tungstate (NiWO4), cobalt tungstate (CoWO4) and bismuth tungstate (Bi2WO6) nanoparticles. CoWO4, NiWO4 and Bi2WO6 were capped with glutathione and covalently linked to three asymmetrical zinc(II) phthalocyanines for PACT. The plate count method was used to investigate the effect of covalently linking asymmetrical zinc(II) phthalocyanines to nanoparticles under light (for PACT against Staphylococcus aureus) and in the dark. Both Pc complexes and the conjugates indicated minimum dark-toxicity. The conjugates showed greater antimicrobial activity against a gram-positive and drug resistant bacteria, Staphylococcus aureus, than Pc complexes alone.
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Austral birds offer insightful complementary models in ecology and evolution
- Authors: Theuerkauf, Jörn , Villavicencio, Camilla P , Adreani, Nicholas M , Attisano, Alfredo , Craig, Adrian J F K , D’Amelio, Pietro B , Gula, Roman , Lee, Alan T K , Mentesana, Lucia , Quillfeldt, Petra , Quirici, Veronica , Quispe, René , Vásquez, Rodrigo A , Wingfield, John C , Masello, Juan F
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449097 , vital:74788 , https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(22)00114-8
- Description: The Southern Hemisphere differs from the Northern Hemisphere in many aspects. However, most ecological and evolutionary research is conducted in the Northern Hemisphere and its conclusions are extrapolated to the entire globe. Therefore, unique organismal and evolutionary characteristics of the south are overlooked. We use ornithology to show the importance of including a southern perspective. We present examples of plumage pigmentation, brood-parasitic nestling ejection, flightlessness, female song, and female aggression modulated by progesterone as complementary models for investigating fundamental biological questions. More research in the Southern Hemisphere, together with increased cooperation among researchers across the hemispheres and within the Southern Hemisphere, will provide a greater global outlook into ecology and evolution.
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Best of both worlds: The thermal physiology of Hydrellia egeriae, a biological control agent for the submerged aquatic weed, Egeria densa in South Africa
- Authors: Smith, Rosali , Coetzee, Julie A , Hill, Martin P
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417913 , vital:71494 , xlink:href="https://doi.org/10.1007/s10526-022-10142-w"
- Description: The submerged aquatic weed, Egeria densa Planch. (Hydrocharitaceae) or Brazilian waterweed, is a secondary invader of eutrophic freshwater systems in South Africa, following the successful management of floating aquatic weeds. In 2018, the leaf and stem-mining fly, Hydrellia egeriae Rodrigues-Júnior, Mathis and Hauser (Diptera: Ephydridae), was released against E. densa, the first agent released against a submerged aquatic weed in South Africa. During its life stages, the biological control agent is exposed to two environments, air and water. The thermal physiology of both life stages was investigated to optimize agent establishment through fine-tuned release strategies. The thermal physiological limits of H. egeriae encompassed its host plant’s optimal temperature range of 10 to 35 °C, with lower and upper critical temperatures of 2.6 to 47.0 °C, lower and upper lethal temperatures of − 5.6 and 40.6 °C for adults, and − 6.3 to 41.3 °C for larvae. Results from development time experiments and degree-day accumulation showed that the agent is capable of establishing at all E. densa sites in South Africa, with between 6.9 and 8.3 generations per year. However, cold temperatures (14 °C) prolonged the agent’s development time to three months, allowing it to only develop through one generation in winter. Predictions obtained from laboratory thermal physiology experiments corroborates field data, where the agent has established at all the sites it was released.
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Beyond epistemology: the challenge of reconceptualising knowledge in higher education
- Authors: Luckett, Kathy , Blackie, Margaret A L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426598 , vital:72371 , xlink:href="https://doi.org/10.1080/13562517.2022.2111206"
- Description: In this Point of Departure, we build on the scholarship of Suellen Shay. Shay explored the nature of higher education, examining assessment and the relation between curriculum and knowledge structures across several disciplines. She drew on the work of Bernstein and in her later work responded to the calls for decolonisation. We first contextualise the work of Basil Bernstein and explain its attraction for scholars of education development in the South African HE context. We then provide a brief summary of recent decolonial scholarship. On this basis, we speculate what a critique and caricature of the Bernsteinian tradition by the decolonial school might look like. In turn we offer a caricatured rebuttal by the Bernsteinian school to the decolonial critique. Finally, we pull our argument together and, by drawing on Bhaskar’s critical realism, assert the importance of an adequate theorisation of ontology.
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Caves, crevices and cooling capacity roost microclimate predicts heat tolerance in bats
- Authors: Czenze, Zenon J , Smit, Ben , van Jaarsveld, Barry , Freeman, Marc T , McKechnie, Andrew
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441571 , vital:73899 , https://doi.org/10.1111/1365-2435.13918
- Description: The microsites that animals occupy during the rest phase of their circa-dian activity cycle influence their physiology and behaviour, but relative-ly few studies have examined correlations between interspecific varia-tion in thermal physiology and roost microclimate. Among bats, there is some evidence that species exposed to high roost temperatures (Troost) possess greater heat tolerance and evaporative cooling capacity, but the small number of species for which both thermal physiology and roost microclimate data exist mean that the generality of this pattern remains unclear.
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Challenges of implementing management accounting innovations
- Authors: Oyewo, Babajide , Hussain, Syed T , Simbi, Chipo
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426264 , vital:72336 , xlink:href="https://www.jstor.org/stable/48717780"
- Description: This study investigates the challenges of implementing innovative management accounting techniques, referred to as strategic management accounting (SMA), the interrelationship among the challenges and the impact of the challenges on SMA usage intensity. From the analysis of survey data obtained from listed manufacturing companies in Nigeria, the result supports the conclusion that SMA implementation challenges are interrelated. However, lack of top management support and low awareness/lack of knowledge are contributory to most of the implementation challenges. The challenges discouraging the intensive use of SMA are the perception that SMA implementation is unnecessary as strategy issues are already integrated in other functions within the organization, high implementation cost and problems relating to information flow between departments within the organization. The current study contributes to knowledge in the sense that it is the first (to the researchers’ knowledge) to examine specifically the interrelationship among SMA implementation challenges in the Nigerian context, thereby drawing attention to the need to consider the challenges to embracing management accounting innovations holistically. Knowledge of SMA implementation challenges could help explain the low adoption rate of SMA in developing countries. Such knowledge might be helpful in providing a robust response to the challenges of implementing management accounting innovations.
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Characterising the shared genetic influences between schizophrenia and subcortical brain regions
- Authors: Wooton, Olivia , Campbell, Megan M , Jahanshad, Neda , Thompson, Paul , Stein, Dan J , Dalvie, Shareefa
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302450 , vital:58197 , xlink:href="https://doi.org/10.1016/j.euroneuro.2022.07.533"
- Description: Background: Abnormalities in brain structural volumes are well established in schizophrenia (SZ) and have been proposed as an endophenotype for the disorder. Despite increasing interest in the genetic relationship between brain structural volumes and SZ, our knowledge of the genetic overlap between the phenotypes is limited. This study aims to extend our current understanding of the shared genetic influences between SZ and subcortical brain volumes using data from the latest genome-wide association studies for the respective phenotypes (GWAS) and novel statistical approaches. Additionally, we will explore whether the association between schizophrenia and abnormal regional brain volumes is causal in nature. Methods: Summary statistics were obtained from the largest Psychiatric Genomic Consortium (PGC)-SZ GWAS (Ncase = 69,369, Ncontrol = 236,642) and the CHARGEENIGMA-UKBB GWAS of volumetric measures for eight subcortical brain regions (the nucleus accumbens, amygdala, brainstem, caudate nucleus, hippocampus, globus pallidus, putamen, and thalamus), and total intracranial volume (N = 30,983 - 40,380). Single nucleotide polymorphism (SNP) effect concordance analysis (SECA) was used to assess pleiotropy and concordance. Genetic correlation was assessed using linkage disequilibrium score regression (LDSR) and the pleiotropy informed conditional FDR approach was applied to identify SNPs associated with SZ conditional on their association with subcortical brain volumes. Mendelian randomization (MR) was used to test for causal association between SZ and each brain region. Results: There was evidence of global pleiotropy between SZ, and all examined subcortical brain regions. Inverse concordance between the genetic determinants of SZ and volumes of the nucleus accumbens, amygdala, brainstem, hippocampus, and thalamus was observed. Increased statistical power to detect SZ risk loci was shown when conditioning on subcortical brain volumes. There was no significant evidence for a causal effect of any of the examined brain regions on schizophrenia risk. Discussion: These data confirm the shared genetic basis of SZ and specific intracranial and subcortical brain volumes and provide evidence for negative concordance between SZ and volumes of the nucleus accumbens, amygdala, brainstem, hippocampus, and thalamus. Leveraging the genetic overlap between SZ and subcortical brain volumes has the potential to provide novel insights into the biological basis of the disorder.
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Climatic suitability and compatibility of the invasive Iris pseudacorus L.(Iridaceae) in the Southern Hemisphere: Considerations for biocontrol
- Authors: Minuti, Gianmarco , Stiers, Iris , Coetzee, Julie A
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423293 , vital:72045 , xlink:href="https://doi.org/10.1016/j.biocontrol.2022.104886"
- Description: Iris pseudacorus L. (Iridaceae) is an emergent macrophyte native to Europe, North Africa and western Asia. Considered invasive in wetland habitats around the world, this species is now the target of a biocontrol programme in the Southern Hemisphere. Native range surveys of the weed led to the selection of the flea beetle, Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae), as a candidate biocontrol agent. An important aspect to consider in weed biocontrol is the ability of an agent to establish and thrive in the environment where it is released. Climatic incompatibility between source and intended release sites can in fact limit the success of a biocontrol programme. In the current study, the potential climatic niche of I. pseudacorus and A. nonstriata in the Southern Hemisphere was analysed. The ecological niche modelling software MaxEnt was used to map the climatic suitability of both organisms across invaded regions in South America, southern Africa and Australasia. Furthermore, occurrence records from each invaded range were used independently to model the climatic compatibility of I. pseudacorus in Europe, in order to prioritize areas of the native range to explore during future surveys for potential biocontrol agents. The models identified areas at high risk of invasion by I. pseudacorus in northern Argentina, Uruguay, southern Brazil and central Chile, as well as numerous provinces of eastern South Africa, Lesotho, southern Australia and New Zealand. Accordingly, the highest climatic suitability for A. nonstriata was predicted across the humid temperate climates of north-east Argentina, Uruguay, southern Brazil, southern South Africa, south-east Australia and New Zealand. These results can eventually be used in future release plans to prioritize areas where establishment and survival of the agent is expected to be highest. At the same time, it may be useful to search the native range of the weed for biological control agents showing high climatic adaptation towards the intended release sites of each invaded range. In this regards, our climatic compatibility models identified high-priority areas across the Mediterranean regions of Italy and southern France, as well as the temperate regions of central and western Europe. Altogether, the current study provides useful new information to tackle the invasion and advance the biocontrol programme of I. pseudacorus in the Southern Hemisphere.
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Comparative avifaunal richness and diversity in invasive Acacia dealbata patches and adjacent montane grasslands
- Authors: Seath, Jessica , Shackleton, Charlie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406585 , vital:70287 , xlink:href="https://hdl.handle.net/10520/ejc-afzoo_v57_i1_a12"
- Description: Abstract Invasive alien species are regarded as the second greatest threat to biodiversity globally. Yet, at a local scale their effects may vary, underlying the requirement for more local-scale studies across taxa and settings. Here we consider the effects of an alien invasive tree (Acacia dealbata, 5–8 m tall) on avifaunal numbers, richness and diversity in A. dealbata patches of three sizes relative to adjacent montane grasslands. Analysis of historical aerial photographs showed that A. dealbata first occurred in the area in the late 1930s/early 1940s and has continued to spread, despite some efforts by the landowner to keep it in check. It now covers approximately 11% of the site. This has provided habitat for a number of bird species more characteristic of wooded vegetation types. The number, richness and diversity of birds were greater in A. dealbata patches than the adjacent grasslands of equivalent size. These measures increased with increasing patch size, but more rapidly for A. dealbata patches than grassland ones. Only six of the 48 species of birds recorded were common between the two vegetation types. The most common feeding guild in the A. dealbata patches was insectivores, whereas in the grasslands it was omnivores. Although the invasion of A. dealbata has added to the habitat diversity of the area, thereby facilitating increased avifaunal diversity, if it continues to spread, then the populations and perhaps richness of grassland birds are likely to be negatively affected.
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Comparison of Task Scheduling Algorithms for Traffic Surveillance Application Using Fog Computing
- Authors: Sinqadu, Mluleki , Shibeshi, Zelalem S , Khalid, Khuram
- Date: 2022
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429150 , vital:72563 , https://doi.org/10.1007/978-3-030-89776-5_3
- Description: One of the issues that service consumers face when using cloud-based solutions is the delay in processing large and real-time data. Fog computing has been introduced as a solution to this issue since it allows the data to be processed at the edge of a network while enabling different tasks to be scheduled for processing in fog devices at the edge network. These devices still require cloud resources to give them the capacity of processing real-time applications. However, scheduling these tasks must be made in such a way that they do not consume all the available resources on a fog device. When a task consumes all available resources, it can lead to network breakdown or high latency which is not acceptable for real-time applications. Therefore, to address this problem, this chapter proposes a task scheduling technique for traffic surveillance vehicular network application through smart cameras. We used the iFogSim simulator, where the scenario of vehicle tracking is considered. Simulations are conducted to find an efficient scheduling algorithm among a pool of available ones that can optimize the energy consumption and average delay of our proposed real-time application model. The results show that the First Come First Serve (FCFS) scheduling algorithm outperforms the Short Job First (SJF), Generalized Priority (GP) and Round Robin (RR) counterparts in terms of average latency, energy usage, execution time and network usage.
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Conceptualising public-private partnerships for social innovation through community engagement in higher education institutions
- Authors: Sibhensana, Bertha , Maistry, Savathrie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426269 , vital:72337 , xlink:href="https://hdl.handle.net/10520/ejc-high_v37_n1_a11"
- Description: The achievement of human social and economic development has been equated to social innovation. Innovation that focuses on the marginalised communities in South Africa becomes necessary to redress the inequalities created pre-democracy. As social institutions, higher education institutions are well positioned to deal with the challenges of the 21st century, which include poverty, unemployment and inequality, through promoting social innovation. In democratic South Africa the relationship between an institution of higher learning and the community can be viewed as a social innovation. This submission implies that one of the objectives of community engagement as a core function of universities, is to drive the social innovation agenda. The university’s contributions to community development can be viewed in terms of its ability to commit to social innovation. It is a better vehicle for understanding and creating social value in all its forms.
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Constellations, technicality, iconisation and Eskom: A case from South Africa’s Business Day
- Authors: Siebörger, Ian , Adendorff, Ralph D
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385350 , vital:68010 , xlink:href="https://doi.org/10.2989/16073614.2022.2040369"
- Description: This article uses Legitimation Code Theory (LCT) and systemic functional linguistics (SFL) to explore interactions between various resources for building economic and political knowledge in a 2015 article from Business Day, a South African newspaper, concerning the country’s energy crisis. We use LCT to observe how three constellations are built in the article: a ‘developmental state’ constellation; a ‘neo-liberal’ constellation; and another underarticulated constellation that selectively draws ideas from both the preceding constellations. These constellations are built through the unfolding of the text using various linguistic resources, which we describe using SFL, including technicality and iconisation. We identify instances where words are charged with both ideational and axiological meaning concurrently, challenging existing understandings of the process of iconisation.
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