Characterising the shared genetic influences between schizophrenia and subcortical brain regions
- Wooton, Olivia, Campbell, Megan M, Jahanshad, Neda, Thompson, Paul, Stein, Dan J, Dalvie, Shareefa
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Circular handmade thatch basket
- Date: 2022 , 2022-09-22
- Subjects: Bam, Brigalia , Basketwork -- Mozambique
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56555 , vital:56855
- Description: Circular handmade thatch basket that was specially made for Dr. Brigalia Bam in Mozambique. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-09-22
- Subjects: Bam, Brigalia , Basketwork -- Mozambique
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56555 , vital:56855
- Description: Circular handmade thatch basket that was specially made for Dr. Brigalia Bam in Mozambique. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Climatic suitability and compatibility of the invasive Iris pseudacorus L.(Iridaceae) in the Southern Hemisphere: Considerations for biocontrol
- Minuti, Gianmarco, Stiers, Iris, Coetzee, Julie A
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Coastal fishes of the western Indian Ocean
- Heemstra, Phillip C. 1941-, Heemstra, Elaine, Ebert, Dave, Holleman, Wouter, Randall, John E
- Authors: Heemstra, Phillip C. 1941- , Heemstra, Elaine , Ebert, Dave , Holleman, Wouter , Randall, John E
- Date: 2022
- Subjects: Marine fishes Indian Ocean , Marine fishes Indian Ocean Identification
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/310495 , vital:59157 , ISBN 978-1-990951-23-7 , ISBN 978-1-998950-35-5 , ISBN 978-1-990951-28-2
- Description: The primary purpose of this book is to provide a means of identifying the more than 3 200 species of coastal fishes known to occur in the Western Indian Ocean (WIO). Coastal fishes are those that inhabit waters generally less than ~200 m deep, the waters over continental and insular shelves, and upper continental slopes. The book also includes some oceanic species and species that live in deeper water, but are sometimes caught in trawls in less than 200 m, or that migrate into shallower waters at night to feed. The Western Indian Ocean (WIO), as treated in these volumes, is the area between Cape Point, South Africa, and 77°34' E, at Kanyakumari (formerly Cape Cormorin), the southernmost point of India, and to 40° S, just south of St Paul Island. Although considered as separate water bodies, the Red Sea and Persian/Arabian Gulf have been included. Some contributors have also chosen to include species from Sri Lanka. The region thus encompasses the entire east and southern coasts of Africa, Madagascar and the various island clusters of the Comoros, the Seychelles, the Maldive and Lakshadweep islands, the Chagos Archipelago and the islands and sea mounts of the Mascarene Plateau, to as far as 40° S, and thus some fishes from St Paul and Amsterdam Islands have been included. This large expanse, stretching from tropical waters of the northwestern Indian Ocean to the warm temperate waters of False Bay, South Africa, includes a number of poorly known biogeographic areas. A map of the entire Indian Ocean is placed on the inside front cover of each printed volume, with some areas in greater detail on the inside back cover. The book does not include distribution maps for species, but gives localities from which species are known, with emphasis on WIO localities; our understanding of distributions of many species is often incomplete. Fishes are the most abundant and diverse group of vertebrates and have colonised every aquatic habitat on Earth: the oceans, lakes, rivers and caves, from polar seas at –2 °C to hot, freshwater springs at 44 °C, and from tropical reefs and mangrove forests to the deepest ocean depths. Fishes are also the most poorly known group of vertebrates. In the 2006 edition of Joseph Nelson’s Fishes of the World the estimate of the number of species of extant fishes worldwide stood at about 23 000. This number is growing annually, and was thought to be about 33 460 species at the end of 2016 (www.fishwisepro.com). Between the years 2000 and 2015 an average of 150 new species of marine fishes were described each year – of which 10% of the total (156 species) were from the WIO. The WIO is home to about 15% of all the marine fish species in the world’s oceans. Another measure of the diversity of fishes of this area is its relatively high level of endemicity, particularly around southern Africa and in the Red Sea. About 13% of southern African marine fishes are endemic, most of these in only five families: Clinidae with about 44 endemic species, Gobiidae with 28, Sparidae with 28, Pentanchidae with 6, and Batrachoididae with 7 endemic species. In the Red Sea at least 170 of the more than 1100 species are endemic. The WIO region is also home to a large human population, representing a wide range of ethnic and cultural backgrounds. The area includes the countries of South Africa, Mozambique, Tanzania, Kenya, Somalia, Eritrea, Sudan, Egypt, Israel, Jordan, Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, Iran, Pakistan, India and Sri Lanka, as well as the many island nations and territories. Many of the people living in coastal areas are dependent on fish catches and other marine resources for both sustenance and often a livelihood, as highly diversified artisanal fisheries make up the bulk of the fishing effort in the region. And, as elsewhere in the world, many of the fish resources have been compromised by commercial interests (including those of other countries), often leaving fish stocks in a poor state. This book has a number of purposes, all of which coalesce around providing users with a better understanding of the area’s fishes and their environment. Accordingly, it includes a number of background chapters covering subjects as diverse as the oceanography of the region, and the history and evolution of the bony fishes. In recent years genetic analysis has proved to be a powerful tool for taxonomists. In many instances molecular results have caused taxonomists to rethink both the definitions of certain taxa and the interrelationships of taxa. In some instances, what were long considered cohesive (monophyletic) taxa were found to include groups of fishes that are in fact not closely related (paraphyletic), while in other instances taxa thought to be distinct were found not to be, meriting their merging with other existing taxa. At times, long-accepted family groups have been divided into two or more distinct families, or separate families have been combined into a single one. Where possible such changes in our understanding of the relationships of fishes are reflected in these volumes. Where some contributors have taken a more conservative approach by awaiting more research and not adopting these changes, alternative taxonomies are noted (see also the introductory chapter on Naming organisms and determining their relationships). For each species in the book, the literature pertinent to that species in the WIO is given: the original species description reference, synonyms for the region and other important taxonomic and biological references. For many commercially important species or fishes of interest to anglers there is additional information on life history, size and capture, and for some but not all species, their IUCN conservation status if Near Threatened, Vulnerable, Endangered or Critically Endangered (in the first instance, valid at the time of writing. See www.iucnredlist.org for current information. Note: we have not included the IUCN conservation status where species are of Least Concern or Data Deficient). Most species are illustrated with photographs, drawings or paintings. Colour photographs and paintings are provided on plates for each volume. , 1st Edition
- Full Text:
- Date Issued: 2022
- Authors: Heemstra, Phillip C. 1941- , Heemstra, Elaine , Ebert, Dave , Holleman, Wouter , Randall, John E
- Date: 2022
- Subjects: Marine fishes Indian Ocean , Marine fishes Indian Ocean Identification
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/310495 , vital:59157 , ISBN 978-1-990951-23-7 , ISBN 978-1-998950-35-5 , ISBN 978-1-990951-28-2
- Description: The primary purpose of this book is to provide a means of identifying the more than 3 200 species of coastal fishes known to occur in the Western Indian Ocean (WIO). Coastal fishes are those that inhabit waters generally less than ~200 m deep, the waters over continental and insular shelves, and upper continental slopes. The book also includes some oceanic species and species that live in deeper water, but are sometimes caught in trawls in less than 200 m, or that migrate into shallower waters at night to feed. The Western Indian Ocean (WIO), as treated in these volumes, is the area between Cape Point, South Africa, and 77°34' E, at Kanyakumari (formerly Cape Cormorin), the southernmost point of India, and to 40° S, just south of St Paul Island. Although considered as separate water bodies, the Red Sea and Persian/Arabian Gulf have been included. Some contributors have also chosen to include species from Sri Lanka. The region thus encompasses the entire east and southern coasts of Africa, Madagascar and the various island clusters of the Comoros, the Seychelles, the Maldive and Lakshadweep islands, the Chagos Archipelago and the islands and sea mounts of the Mascarene Plateau, to as far as 40° S, and thus some fishes from St Paul and Amsterdam Islands have been included. This large expanse, stretching from tropical waters of the northwestern Indian Ocean to the warm temperate waters of False Bay, South Africa, includes a number of poorly known biogeographic areas. A map of the entire Indian Ocean is placed on the inside front cover of each printed volume, with some areas in greater detail on the inside back cover. The book does not include distribution maps for species, but gives localities from which species are known, with emphasis on WIO localities; our understanding of distributions of many species is often incomplete. Fishes are the most abundant and diverse group of vertebrates and have colonised every aquatic habitat on Earth: the oceans, lakes, rivers and caves, from polar seas at –2 °C to hot, freshwater springs at 44 °C, and from tropical reefs and mangrove forests to the deepest ocean depths. Fishes are also the most poorly known group of vertebrates. In the 2006 edition of Joseph Nelson’s Fishes of the World the estimate of the number of species of extant fishes worldwide stood at about 23 000. This number is growing annually, and was thought to be about 33 460 species at the end of 2016 (www.fishwisepro.com). Between the years 2000 and 2015 an average of 150 new species of marine fishes were described each year – of which 10% of the total (156 species) were from the WIO. The WIO is home to about 15% of all the marine fish species in the world’s oceans. Another measure of the diversity of fishes of this area is its relatively high level of endemicity, particularly around southern Africa and in the Red Sea. About 13% of southern African marine fishes are endemic, most of these in only five families: Clinidae with about 44 endemic species, Gobiidae with 28, Sparidae with 28, Pentanchidae with 6, and Batrachoididae with 7 endemic species. In the Red Sea at least 170 of the more than 1100 species are endemic. The WIO region is also home to a large human population, representing a wide range of ethnic and cultural backgrounds. The area includes the countries of South Africa, Mozambique, Tanzania, Kenya, Somalia, Eritrea, Sudan, Egypt, Israel, Jordan, Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, Iran, Pakistan, India and Sri Lanka, as well as the many island nations and territories. Many of the people living in coastal areas are dependent on fish catches and other marine resources for both sustenance and often a livelihood, as highly diversified artisanal fisheries make up the bulk of the fishing effort in the region. And, as elsewhere in the world, many of the fish resources have been compromised by commercial interests (including those of other countries), often leaving fish stocks in a poor state. This book has a number of purposes, all of which coalesce around providing users with a better understanding of the area’s fishes and their environment. Accordingly, it includes a number of background chapters covering subjects as diverse as the oceanography of the region, and the history and evolution of the bony fishes. In recent years genetic analysis has proved to be a powerful tool for taxonomists. In many instances molecular results have caused taxonomists to rethink both the definitions of certain taxa and the interrelationships of taxa. In some instances, what were long considered cohesive (monophyletic) taxa were found to include groups of fishes that are in fact not closely related (paraphyletic), while in other instances taxa thought to be distinct were found not to be, meriting their merging with other existing taxa. At times, long-accepted family groups have been divided into two or more distinct families, or separate families have been combined into a single one. Where possible such changes in our understanding of the relationships of fishes are reflected in these volumes. Where some contributors have taken a more conservative approach by awaiting more research and not adopting these changes, alternative taxonomies are noted (see also the introductory chapter on Naming organisms and determining their relationships). For each species in the book, the literature pertinent to that species in the WIO is given: the original species description reference, synonyms for the region and other important taxonomic and biological references. For many commercially important species or fishes of interest to anglers there is additional information on life history, size and capture, and for some but not all species, their IUCN conservation status if Near Threatened, Vulnerable, Endangered or Critically Endangered (in the first instance, valid at the time of writing. See www.iucnredlist.org for current information. Note: we have not included the IUCN conservation status where species are of Least Concern or Data Deficient). Most species are illustrated with photographs, drawings or paintings. Colour photographs and paintings are provided on plates for each volume. , 1st Edition
- Full Text:
- Date Issued: 2022
Comparative avifaunal richness and diversity in invasive Acacia dealbata patches and adjacent montane grasslands
- Seath, Jessica, Shackleton, Charlie M
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Comparison of Task Scheduling Algorithms for Traffic Surveillance Application Using Fog Computing
- Sinqadu, Mluleki, Shibeshi, Zelalem S, Khalid, Khuram
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Conceptualising public-private partnerships for social innovation through community engagement in higher education institutions
- Sibhensana, Bertha, Maistry, Savathrie M
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Constellations, technicality, iconisation and Eskom: A case from South Africa’s Business Day
- Siebörger, Ian, Adendorff, Ralph D
- 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.
- Full Text:
- Date Issued: 2022
- 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.
- Full Text:
- Date Issued: 2022
Cross boundary fluxes: Basal resource use by aquatic invertebrates matches fatty acid transfers from river to land
- Moyo, Sydney, Richoux, Nicole B
- Authors: Moyo, Sydney , Richoux, Nicole B
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454304 , vital:75334 , xlink:href="https://doi.org/10.1016/j.limno.2022.126035"
- Description: Emerging insects transfer valuable lipids originating in aquatic food sources to terrestrial consumers. The objective of this study was to determine how the export of physiologically important fatty acids from a river to adjacent land via insect emergence relates to the type and quality of the aquatic food consumed, and which emerging insects were primarily responsible for these fluxes. We ran mixing models and hypervolumes incorporating stable carbon isotope ratios of basal resources and emergent invertebrates to determine the major contributors to insect larvae diets. Our data revealed that aquatic food sources (epiphyton, epilithon and suspended particulate matter) were the major organic matter sources (more than 50 %) supporting consumers (Diptera, Ephemeroptera, Odonata and Trichoptera), with allochthonous food sources (C3 plants) being of importance at upstream sites. We calculated fluxes of highly unsaturated fatty acids (HUFAs) via emerging insects and found that these corresponded with the spatial and temporal patterns in the nutritional quality of these same basal resources in the river (quality measured as concentrations of HUFAs). These patterns provide evidence of a direct coupling between food quality and trophic subsidy fluxes from water to land, particularly by emergent dipterans and ephemeropterans.
- Full Text:
- Date Issued: 2022
- Authors: Moyo, Sydney , Richoux, Nicole B
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454304 , vital:75334 , xlink:href="https://doi.org/10.1016/j.limno.2022.126035"
- Description: Emerging insects transfer valuable lipids originating in aquatic food sources to terrestrial consumers. The objective of this study was to determine how the export of physiologically important fatty acids from a river to adjacent land via insect emergence relates to the type and quality of the aquatic food consumed, and which emerging insects were primarily responsible for these fluxes. We ran mixing models and hypervolumes incorporating stable carbon isotope ratios of basal resources and emergent invertebrates to determine the major contributors to insect larvae diets. Our data revealed that aquatic food sources (epiphyton, epilithon and suspended particulate matter) were the major organic matter sources (more than 50 %) supporting consumers (Diptera, Ephemeroptera, Odonata and Trichoptera), with allochthonous food sources (C3 plants) being of importance at upstream sites. We calculated fluxes of highly unsaturated fatty acids (HUFAs) via emerging insects and found that these corresponded with the spatial and temporal patterns in the nutritional quality of these same basal resources in the river (quality measured as concentrations of HUFAs). These patterns provide evidence of a direct coupling between food quality and trophic subsidy fluxes from water to land, particularly by emergent dipterans and ephemeropterans.
- Full Text:
- Date Issued: 2022
Cultural Seascapes in the ‘Sea of Calms’ and La Restinga Coast
- De la Cruz-Modino, Raquel, Piñeiro-Corbeira, Cristina, Aswani, Shankar, González-Cruz, Carla, Domínguez, David, Ordóñez García, Paula, Santana-Talavera, Agustín, Pascual-Fernández, José
- Authors: De la Cruz-Modino, Raquel , Piñeiro-Corbeira, Cristina , Aswani, Shankar , González-Cruz, Carla , Domínguez, David , Ordóñez García, Paula , Santana-Talavera, Agustín , Pascual-Fernández, José
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/391319 , vital:68641 , ISBN 978-3-031-07289-5 , https://doi.org/10.1007/978-3-031-07289-5
- Description: El Hierro has been characterized by the balance between human development and environmental sustainability. The island was historically far from the mass tourism developments dominant on the other Canary Islands. Tourism accommodations in El Hierro are few compared to more developed coastal areas in the Archipelago, and recreational activities are mainly linked to cultural and natural sites and resources. This chapter focuses on La Restinga fishing village and its coasts, where the ‘Sea of Calms’ and one multiple-use Marine Reserve (MR) are located, both of which became popular over the last decade. The tourist development experience has promoted a new way of looking at the sea and conceptualizing its habitats and populations. In 2014, after the submarine volcano eruption occurred in 2011, we estimated that at least 25,391 dives had been carried out in the diving spots established by the MR and other diving sites close to La Restinga. Despite the difficulties experienced after the volcano eruption, a unique imaginaire has been consolidated, thanks to the image of the island's exclusive nature and iconic elements. In addition, the rapid recovery of the destination is an excellent example of how the tourism system can adapt and incorporate unexpected events such as volcanic eruptions.
- Full Text:
- Date Issued: 2022
- Authors: De la Cruz-Modino, Raquel , Piñeiro-Corbeira, Cristina , Aswani, Shankar , González-Cruz, Carla , Domínguez, David , Ordóñez García, Paula , Santana-Talavera, Agustín , Pascual-Fernández, José
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/391319 , vital:68641 , ISBN 978-3-031-07289-5 , https://doi.org/10.1007/978-3-031-07289-5
- Description: El Hierro has been characterized by the balance between human development and environmental sustainability. The island was historically far from the mass tourism developments dominant on the other Canary Islands. Tourism accommodations in El Hierro are few compared to more developed coastal areas in the Archipelago, and recreational activities are mainly linked to cultural and natural sites and resources. This chapter focuses on La Restinga fishing village and its coasts, where the ‘Sea of Calms’ and one multiple-use Marine Reserve (MR) are located, both of which became popular over the last decade. The tourist development experience has promoted a new way of looking at the sea and conceptualizing its habitats and populations. In 2014, after the submarine volcano eruption occurred in 2011, we estimated that at least 25,391 dives had been carried out in the diving spots established by the MR and other diving sites close to La Restinga. Despite the difficulties experienced after the volcano eruption, a unique imaginaire has been consolidated, thanks to the image of the island's exclusive nature and iconic elements. In addition, the rapid recovery of the destination is an excellent example of how the tourism system can adapt and incorporate unexpected events such as volcanic eruptions.
- Full Text:
- Date Issued: 2022
Dark brown three-legged round African clay pot
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Pottery, African
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56874 , vital:57197
- Description: Dark brown round African clay pot, with three legs and a shield pattern. Interior of pot is cream coloured. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
- Date: 2022 , 2022-10-05
- Subjects: Bam, Brigalia , Pottery, African
- Language: English
- Type: realia
- Identifier: http://hdl.handle.net/10948/56874 , vital:57197
- Description: Dark brown round African clay pot, with three legs and a shield pattern. Interior of pot is cream coloured. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 2022
Decoration of glass wool with zinc (II) phthalocyanine for the photocatalytic transformation of methyl orange
- Sindelo, Azole, Britton, Jonathan, Lanterna, Anabel E, Scaiano, Juan C, Nyokong, Tebello
- Authors: Sindelo, Azole , Britton, Jonathan , Lanterna, Anabel E , Scaiano, Juan C , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295742 , vital:57374 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114127"
- Description: Zinc phthalocyanines containing one (mono carboxy phenoxy, ZnMCPPc), four (tetra carboxy phenoxy, ZnTCPPc), and eight (tetra isophthalic acid, ZnTIPAPc) carboxyl groups were covalently conjugated to amine-functionalized glass wool (GW). The GW-Pcs were characterized and evaluated for singlet oxygen generation. The photocatalytic efficiencies of the GW-Pcs were assessed using methyl orange. Glass wool alone and the modified conjugates exhibited low to no degradation of methyl orange in the dark. The improved catalytic rate was observed for GW-ZnMCPPc and GW-ZnTCPPc compared to GW-ZnTIPAPc due to the latter's lower singlet oxygen quantum yield generation. In addition, the modified glass wool was recyclable, making it suitable candidates for future environmental applications.
- Full Text:
- Date Issued: 2022
- Authors: Sindelo, Azole , Britton, Jonathan , Lanterna, Anabel E , Scaiano, Juan C , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295742 , vital:57374 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114127"
- Description: Zinc phthalocyanines containing one (mono carboxy phenoxy, ZnMCPPc), four (tetra carboxy phenoxy, ZnTCPPc), and eight (tetra isophthalic acid, ZnTIPAPc) carboxyl groups were covalently conjugated to amine-functionalized glass wool (GW). The GW-Pcs were characterized and evaluated for singlet oxygen generation. The photocatalytic efficiencies of the GW-Pcs were assessed using methyl orange. Glass wool alone and the modified conjugates exhibited low to no degradation of methyl orange in the dark. The improved catalytic rate was observed for GW-ZnMCPPc and GW-ZnTCPPc compared to GW-ZnTIPAPc due to the latter's lower singlet oxygen quantum yield generation. In addition, the modified glass wool was recyclable, making it suitable candidates for future environmental applications.
- Full Text:
- Date Issued: 2022
Deep Palmprint Recognition with Alignment and Augmentation of Limited Training Samples
- Brown, Dane, Bradshaw, Karen L
- Authors: Brown, Dane , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440249 , vital:73760 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
- Authors: Brown, Dane , Bradshaw, Karen L
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440249 , vital:73760 , xlink:href="https://doi.org/10.1007/s42979-021-00859-3"
- Description: This paper builds upon a previously proposed automatic palmprint alignment and classification system. The proposed system was geared towards palmprints acquired from either contact or contactless sensors. It was robust to finger location and fist shape changes—accurately extracting the palmprints in images without fingers. An extension to this previous work includes comparisons of traditional and deep learning models, both with hyperparameter tuning. The proposed methods are compared with related verification systems and a detailed evaluation of open-set identification. The best results were yielded by a proposed Convolutional Neural Network, based on VGG-16, and outperforming tuned VGG-16 and Xception architectures. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling significant accuracy gains. Highlights include near-zero and zero EER on IITD-Palmprint verification using one training sample and leave-one-out strategy, respectively. Therefore, the proposed palmprint system is practical as it is effective on data containing many and few training examples.
- Full Text:
- Date Issued: 2022
Design and fabrication of electrochemical sensor based on molecularly imprinted polymer loaded onto silver nanoparticles for the detection of 17-β-Estradiol
- Regasa, Melkamu Biyana, Nyokong, Tebello
- Authors: Regasa, Melkamu Biyana , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300287 , vital:57913 , xlink:href="https://doi.org/10.1002/jmr.2978"
- Description: In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-β-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.
- Full Text:
- Date Issued: 2022
- Authors: Regasa, Melkamu Biyana , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300287 , vital:57913 , xlink:href="https://doi.org/10.1002/jmr.2978"
- Description: In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p-aminophenol) supported by silver nanoparticles capped with 2-mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17-β-estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite-based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.
- Full Text:
- Date Issued: 2022
Detecting and removing sample contamination in phylogenomic data: an example and its implications for Cicadidae phylogeny (Insecta Hemiptera).
- Owen, Christopher L, Marshall, David C, Wade, Elizabeth J, Meister, Russ, Goemans, Geert, Kunte, Krushnamegh, Moulds, Max, Hill, Kathy, Villet, Martin H, Pham, Thai-Hong, Kortyna, Michelle, Lemmon, Emily M, Lemmon, Alan R, Simon, Chris
- Authors: Owen, Christopher L , Marshall, David C , Wade, Elizabeth J , Meister, Russ , Goemans, Geert , Kunte, Krushnamegh , Moulds, Max , Hill, Kathy , Villet, Martin H , Pham, Thai-Hong , Kortyna, Michelle , Lemmon, Emily M , Lemmon, Alan R , Simon, Chris
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440749 , vital:73809 , https://doi.org/10.1093/sysbio/syac043
- Description: Contamination of a genetic sample with DNA from one or more nontarget species is a continuing concern of molecular phylogenetic studies, both Sanger sequencing studies and next-generation sequencing studies. We developed an automated pipeline for identifying and excluding likely cross-contaminated loci based on the detection of bimodal distributions of patristic distances across gene trees. When contamination occurs between samples within a data set, a comparison between a contaminated sample and its contaminant taxon will yield bimodal distributions with one peak close to zero patristic distance. This new method does not rely on a priori knowledge of taxon relatedness nor does it determine the causes(s) of the contamination. Exclusion of putatively contaminated loci from a data set generated for the insect family Cicadidae showed that these sequences were affecting some topological patterns and branch supports, although the effects were sometimes subtle, with some contamination-influenced relationships exhibiting strong bootstrap support. Long tip branches and outlier values for one anchored phylogenomic pipeline statistic (AvgNHomologs) were correlated with the presence of contamination.
- Full Text:
- Date Issued: 2022
- Authors: Owen, Christopher L , Marshall, David C , Wade, Elizabeth J , Meister, Russ , Goemans, Geert , Kunte, Krushnamegh , Moulds, Max , Hill, Kathy , Villet, Martin H , Pham, Thai-Hong , Kortyna, Michelle , Lemmon, Emily M , Lemmon, Alan R , Simon, Chris
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440749 , vital:73809 , https://doi.org/10.1093/sysbio/syac043
- Description: Contamination of a genetic sample with DNA from one or more nontarget species is a continuing concern of molecular phylogenetic studies, both Sanger sequencing studies and next-generation sequencing studies. We developed an automated pipeline for identifying and excluding likely cross-contaminated loci based on the detection of bimodal distributions of patristic distances across gene trees. When contamination occurs between samples within a data set, a comparison between a contaminated sample and its contaminant taxon will yield bimodal distributions with one peak close to zero patristic distance. This new method does not rely on a priori knowledge of taxon relatedness nor does it determine the causes(s) of the contamination. Exclusion of putatively contaminated loci from a data set generated for the insect family Cicadidae showed that these sequences were affecting some topological patterns and branch supports, although the effects were sometimes subtle, with some contamination-influenced relationships exhibiting strong bootstrap support. Long tip branches and outlier values for one anchored phylogenomic pipeline statistic (AvgNHomologs) were correlated with the presence of contamination.
- Full Text:
- Date Issued: 2022
Developing Relationships for Community-Based Research at Rhodes University: Values, Principles and Challenges
- Rouillard, Tessa, Deponselle, Keagan, Bezerra, Joana C
- Authors: Rouillard, Tessa , Deponselle, Keagan , Bezerra, Joana C
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426430 , vital:72352 , xlink:href="https://doi.org/10.3390/su142315525"
- Description: In addition to providing benefits to people, protected areas are valued in ways that go beyond the tangible. A sense of place, and the collection of values, feelings, and meanings associated with a place, can illuminate people-place relationships. Understanding how people relate to a place is essential in acquiring support for protected areas. This research investigates tourists’ and residents’ sense of place in Knysna, an open-access section of the Garden Route National Park, South Africa. Data was collected through questionnaires and semi-structured interviews. The sense of place was characterised using five variables: physical, cultural, social, dependent, and ideological. Although ‘physical’ was the dominant variable for both tourists and residents, the ‘ideological’ for residents and the ‘cultural’ for tourists came second, highlighting the importance of safe places and recreational activities, respectively. The physical environment influences sense of place, and the importance of protected areas to stakeholders offers an opportunity for management to engage with the public.
- Full Text:
- Date Issued: 2022
- Authors: Rouillard, Tessa , Deponselle, Keagan , Bezerra, Joana C
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426430 , vital:72352 , xlink:href="https://doi.org/10.3390/su142315525"
- Description: In addition to providing benefits to people, protected areas are valued in ways that go beyond the tangible. A sense of place, and the collection of values, feelings, and meanings associated with a place, can illuminate people-place relationships. Understanding how people relate to a place is essential in acquiring support for protected areas. This research investigates tourists’ and residents’ sense of place in Knysna, an open-access section of the Garden Route National Park, South Africa. Data was collected through questionnaires and semi-structured interviews. The sense of place was characterised using five variables: physical, cultural, social, dependent, and ideological. Although ‘physical’ was the dominant variable for both tourists and residents, the ‘ideological’ for residents and the ‘cultural’ for tourists came second, highlighting the importance of safe places and recreational activities, respectively. The physical environment influences sense of place, and the importance of protected areas to stakeholders offers an opportunity for management to engage with the public.
- Full Text:
- Date Issued: 2022
Developing Relationships for Community-Based Research at Rhodes University: Values, Principles and Challenges
- Hornby, Diana, Maistry, Savathrie M
- Authors: Hornby, Diana , Maistry, Savathrie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433524 , vital:72981 , ISBN 978-3-030-86401-9 , https://doi.org/10.1007/978-3-030-86402-6_6
- Description: Post-apartheid education policy in South Africa mandates that universities should become more responsive to the socio-economic development of the country, positioning community engagement as a core function of higher education. Community engagement in all its forms, and particularly in the form of community-based research, should develop the social responsibility of both students and the institution by providing opportunities for partnering in community-based projects to promote the social good, thus narrowing the gap between universities and communities. The Community Engagement Division at Rhodes University in the Eastern Cape province of South Africa, supported by the highest level of management of the institution, was fully aware that removal of the ‘ivory tower’ image was a herculean task. Thus, they developed a set of values and principles to guide the establishment of community partnerships with the community the university serves. This chapter explains these values and principles, using the Reviving Schools community engagement initiative as an example. It discusses some of the challenges experienced and how they were overcome to build research relationships and a sense of ‘community’ between Rhodes University and its external partners in Makhanda.
- Full Text:
- Date Issued: 2022
- Authors: Hornby, Diana , Maistry, Savathrie M
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433524 , vital:72981 , ISBN 978-3-030-86401-9 , https://doi.org/10.1007/978-3-030-86402-6_6
- Description: Post-apartheid education policy in South Africa mandates that universities should become more responsive to the socio-economic development of the country, positioning community engagement as a core function of higher education. Community engagement in all its forms, and particularly in the form of community-based research, should develop the social responsibility of both students and the institution by providing opportunities for partnering in community-based projects to promote the social good, thus narrowing the gap between universities and communities. The Community Engagement Division at Rhodes University in the Eastern Cape province of South Africa, supported by the highest level of management of the institution, was fully aware that removal of the ‘ivory tower’ image was a herculean task. Thus, they developed a set of values and principles to guide the establishment of community partnerships with the community the university serves. This chapter explains these values and principles, using the Reviving Schools community engagement initiative as an example. It discusses some of the challenges experienced and how they were overcome to build research relationships and a sense of ‘community’ between Rhodes University and its external partners in Makhanda.
- Full Text:
- Date Issued: 2022
Development and in vitro biological studies of polymer-based wound dressings with a high haemostatic ability for the management of wounds
- Nqoro, Xhamla https://orcid.org/0000-0002-2065-3629
- 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
- 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
Digitalisation and Transformative Learning for Sustainable Futures in Rural Africa Leaving No One Behind
- Shetye, Nyanta, Lotz-Sisitka, Heila, Albrecht, Eike, Durr, Sarah, Marx, Dirk, Chirambo, Dumisani, Metelerkamp, Luke, van Zyl-Bulitta, Verena
- Authors: Shetye, Nyanta , Lotz-Sisitka, Heila , Albrecht, Eike , Durr, Sarah , Marx, Dirk , Chirambo, Dumisani , Metelerkamp, Luke , van Zyl-Bulitta, Verena
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435263 , vital:73143 , ISBN 9781928502241 , https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003274322-14/digitalisation-transformative-learning-sustainable-futures-rural-africa-niyanta-shetye-heila-lotz-sisitka-eike-albrecht-sarah-durr-dirk-marx-dumisani-chirambo-luke-metelerkamp-verena-van-zyl-bulitta
- Description: This chapter assesses the use of Information and Telecommunication Technologies (ICTs) for social and community learning to achieve sustainable development in rural communities in Africa. It focuses on new and emerging trends in the cooperation between the African Union and European Union (AU–EU) and links two thematic areas; namely green transitions and digital transformations. The chapter highlights low-cost and effective digital learning solutions. It is based on a literature review and cases that provide insight into potential AU–EU cooperation and the “leave no one behind” agenda. The chapter argues that in addition to digital technology transfer, innovation and investments are needed in building a learning-centred support for green transitioning and digital cooperation. Hence, we focus on transformative learning opportunities and informal Education for Sustainable Development (ESD). In response to ICTs becoming a catalyst for such a transformation, we seek insights into how constructive AU–EU cooperation and co-learning can pave ways for societal transformations, particularly in rural communities.
- Full Text:
- Date Issued: 2022
- Authors: Shetye, Nyanta , Lotz-Sisitka, Heila , Albrecht, Eike , Durr, Sarah , Marx, Dirk , Chirambo, Dumisani , Metelerkamp, Luke , van Zyl-Bulitta, Verena
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435263 , vital:73143 , ISBN 9781928502241 , https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003274322-14/digitalisation-transformative-learning-sustainable-futures-rural-africa-niyanta-shetye-heila-lotz-sisitka-eike-albrecht-sarah-durr-dirk-marx-dumisani-chirambo-luke-metelerkamp-verena-van-zyl-bulitta
- Description: This chapter assesses the use of Information and Telecommunication Technologies (ICTs) for social and community learning to achieve sustainable development in rural communities in Africa. It focuses on new and emerging trends in the cooperation between the African Union and European Union (AU–EU) and links two thematic areas; namely green transitions and digital transformations. The chapter highlights low-cost and effective digital learning solutions. It is based on a literature review and cases that provide insight into potential AU–EU cooperation and the “leave no one behind” agenda. The chapter argues that in addition to digital technology transfer, innovation and investments are needed in building a learning-centred support for green transitioning and digital cooperation. Hence, we focus on transformative learning opportunities and informal Education for Sustainable Development (ESD). In response to ICTs becoming a catalyst for such a transformation, we seek insights into how constructive AU–EU cooperation and co-learning can pave ways for societal transformations, particularly in rural communities.
- Full Text:
- Date Issued: 2022
Double stimulation and transformative agency for leadership development of school learners in Southern Africa
- Authors: Grant, Carolyn
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281035 , vital:55685 , xlink:href="https://doi.org/10.1080/14681366.2020.1805495"
- Description: Learners, because of their minor status, are a virtual absence in everyday school leadership work, particularly on the African continent. School leadership, therefore, continues to be misconceived as an adult phenomenon. Framed by Cultural Historical Activity Theory, this paper reports on a Southern African Higher Education studythat engages with the Vygotskian principle of ‘double stimulation’ and its relationship to transformative agency in the context of a school-based learner leadership development initiative. One school change project was purposively selected as the case, and data were drawn from a postgraduate student research report and self-reflective journal. Drawing on the Sannino model of double stimulation, the paper explores the phases of double stimulation as well as instances of transformative agency evident in the data, and speculates about the relationship between double stimulation and transformative agency in the leadership development of learners.
- Full Text:
- Date Issued: 2022
- Authors: Grant, Carolyn
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281035 , vital:55685 , xlink:href="https://doi.org/10.1080/14681366.2020.1805495"
- Description: Learners, because of their minor status, are a virtual absence in everyday school leadership work, particularly on the African continent. School leadership, therefore, continues to be misconceived as an adult phenomenon. Framed by Cultural Historical Activity Theory, this paper reports on a Southern African Higher Education studythat engages with the Vygotskian principle of ‘double stimulation’ and its relationship to transformative agency in the context of a school-based learner leadership development initiative. One school change project was purposively selected as the case, and data were drawn from a postgraduate student research report and self-reflective journal. Drawing on the Sannino model of double stimulation, the paper explores the phases of double stimulation as well as instances of transformative agency evident in the data, and speculates about the relationship between double stimulation and transformative agency in the leadership development of learners.
- Full Text:
- Date Issued: 2022