The photophysicochemical properties and photodynamic therapy activity of Schiff base substituted phthalocyanines doped into silica nanoparticles and conjugated to folic acid
- Authors: Magadla, Aviwe , Babu, Balaji , Sen, Pinar , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185407 , vital:44384 , xlink:href="https://doi.org/10.1016/j.poly.2021.115227"
- Description: This work explores the synthesis, photophysicochemical properties and photodynamic activity (PDT) of tetrakis [N,N’–bis (4-(diethylamino)benzylidene) amino)propan-2-yl)oxy) phthalocyaninato] Zn (II) (3) and tetra-phenoxy N,N-dimethyl-4-((methylimino) Zn (II) (4) when the encapsulated into silica nanoparticles (SiNPs) followed by conjugation of folic acid (FA). The synthesised complexes and their doped analogues are examined for their PDT activity using MCF-7 cells. All the complexes showed dark toxicity that is >80%. The folic acid conjugates, MPc@SiNPs-FA showed greater photocytoxicity against MCF-7 cells upon irradiation with laser light.
- Full Text:
The politics of postgraduate education: supervising in a troubled world
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434502 , vital:73069 , ISBN 9781991201225 , https://www.google.co.za/books/edition/The_Global_Scholar/KvQ3EAAAQBAJ?hl=enandgbpv=0
- Description: In our rapidly globalising world, "the global scholar" is a key concept for reimagining the roles of academics at the nexus of the global and the local. This book critically explores the implications of the concept for understanding postgraduate studies and supervision. It uses three conceptual lenses - "horizon", "currency" and "trajec-tory" - to organise the thirteen chapters, concluding with a reflection on the implica-tions of Covid-19 for postgraduate studies and supervision. Authors bring their perspectives on the global scholar from a variety of contexts, including South Afri-ca, Australia, the United States, the United Kingdom, Chile, Germany, Cyprus, Kenya and Israel. They explore issues around policy, research and practice, sharing a con-cern with the relation between the local and the global, and a passion for advancing postgraduate studies and supervision.
- Full Text:
The potential influence of commercial plant nurseries in shaping the urban forest in South Africa
- Authors: Arnoldi, Marco , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398408 , vital:69409 , xlink:href="https://doi.org/10.1016/j.ufug.2021.127254"
- Description: A substantial portion of urban green infrastructure is under private tenure in residents’ and business/corporate gardens. Therefore, the ways that urban residents manage their gardens can influence the type, quantity and quality of ecosystem services and disservices in urban areas. Plant nurseries are a major source of trees for urban residents, and so the types of trees and species that nurseries stock influence the composition of private gardens. Consequently, this study aimed to examine the roles that plant nurseries play in shaping the urban forest in South Africa. To do so, an online and direct questionnaire was used to gather data from 30 nurseries across 19 urban centres in South Africa. The main questions included species selection criteria, customer tree inquiries, best-selling tree species, attitudes towards increasing urban tree cover and diversity and whether they think climate change will affect the selection of species to stock. The results show that there is a strong preference for indigenous trees, which were also most commonly listed as best-sellers. Non-native species that were commonly sold were ones that provided provisioning services, particularly edible fruits. Drought tolerance influenced selection criteria and customer demand. Vachellia spp. and Olea europaea were commonly inquired about and most commonly listed amongst the best-sellers. Nursery owners valued the importance of increasing tree cover and diversity in urban areas, listing many perceived benefits for doing so. We conclude that there is a clear preference for indigenous tree species by customers and nursery owners, which in time could increase the proportion and cover of native species.
- Full Text:
The practice and design of social-ecological systems research
- Authors: de Vos, Alta , Maciejewski, Kristine , Bodin, Orjan , Norstrom, Albert , Schluter, Maja , Tengo, Maria
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433826 , vital:73003 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Studying social-ecological systems (SES) can be a challenging task, as explained in Chapter 2. Phenomena of interest and characteristics of SES research result from both social and ecological processes, and complicated feedback dynamics blur the distinction between cause and effect (Young et al. 2006). Furthermore, multiple causal processes may be operating simultaneously, outcomes are strongly influenced by the system’s context and it is difficult to determine system boundaries (Bodin and Prell 2011).
- Full Text:
The role of causal knowledge in stigma considerations in African genomics research
- Authors: Matshabane, Olivia P , Campbell, Megan , Appelbaum, Paul S , Marshall, Patricia A , Stein, Dan J , de Vries, Jantina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/302578 , vital:58209 , xlink:href="https://doi.org/10.1016/j.socscimed.2021.113902"
- Description: Introduction: Advances in genomics research have raised several ethical concerns. One concern is the potential impact of genomics research on stigma experienced by people affected by a disease. Studies have found that the type of illness as well as disease causal beliefs impact on the relation between genetic attribution and stigma. This study explored the potential impact of genetic attribution of disease on stigma among Xhosa people with Rheumatic Heart Disease (RHD). Methods: Study participants were 46 Xhosa people with RHD living in the Western Cape Province of South Africa. Using video vignettes in 7 focus group discussions we explored whether and how genetic attribution may impact on disease-stigma. Vignettes introduced participants to non-genetic and genetic causal explanations and were followed-up with a series of open-ended questions eliciting their perceptions of non-genetic disease causes as well as genetic causation and its impact on internalised stigma. Results: This study found that Xhosa people with RHD have a general understanding of genetics and genetic attribution for disease. Additionally, and not withstanding their genetic knowledge, these participants hold multiple disease causal beliefs including genetic, infectious disease, psychosocial, behavioural and cultural explanations. While there was evidence of internalised stigma experiences among participants, these appeared not to be related to a genetic attribution to the disease. Discussion: The findings of this study provide clues as to why it is unlikely that a genetic conceptualisation of disease impacts internalised stigma experiences of Xhosa people. The causal explanations provided by participants reflect their cultural understandings and their context, namely, living in low-income and poverty-stricken environments. Divergence in these findings from much of the evidence from high-income countries emphasises that context matters when considering the impact of genetic attribution on stigma and caution against generalising findings from one part of the globe to another.
- Full Text:
The Role of Ecological Infrastructure (EI) in Mitigating the Impacts of Droughts
- Authors: Mantel, Sukhmani K , Xoxo, Sinetemba , Mahlaba, Bawinile , Tanner, Jane L , Le Maître, David
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438209 , vital:73443 , ISBN 978-0-6392-0304-1 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2928_web.pdf
- Description: To explain how well-managed ecological infrastructure can help to miti-gate the impacts of droughts on human livelihoods and well-being and to propose strategic responses that will maintain and enhance the value of this service that people will embrace and implement.
- Full Text:
The role of mass-rearing in weed biological control projects in South Africa
- Authors: Hill, Martin P , Conlong, Desmond , Zachariades, Costas , Coetzee, Julie A , Paterson, Iain D , Miller, Benjamin E , Foxcroft, Llewellyn , van der Westhuizen, L
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407094 , vital:70335 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a22"
- Description: It has been documented that the continual release of high numbers of biological control (biocontrol) agents for weeds increases the likelihood of agent establishment and has been shown to reduce the time between the first release and subsequent control of the target weed. Here we review the mass-rearing activities for weed biocontrol agents in South Africa between 2011 and 2020. Some 4.7 million individual insects from 40 species of biocontrol agent have been released on 31 weed species at over 2000 sites throughout South Africa during the last decade. These insects were produced at mass-rearing facilities at eight research institutions, five schools and 10 Non-Governmental Organizations. These mass-rearing activities have created employment for 41 fulltime, fixed contract staff, of which 11 are people living with physical disabilities. To improve the uptake of mass-rearing through community engagement, appropriate protocols are required to ensure that agents are produced in high numbers to suppress invasive alien plant populations in South Africa.
- Full Text:
Theorising Active Learning–A Historical Analysis
- Authors: Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435072 , vital:73128 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: There is no definitive or consensual Education for Sustainable Development (ESD) pedagogy but there is a suite of techniques which, if examined, will reveal similar features and principles. For example, in its ESD sourcebook, Unesco (2012) highlights pedagogies featuring question-orientated, analytical, critical and decisive skills, as well as relational pedagogies with features such as learner-centredness and participation. In its later Roadmap for Implementing the Global Action Programme for Education for Sustainable Development, Unesco calls for pedagogies that support the designing of ‘teaching and learning in an interactive, learner-centred way that enables exploratory, action-oriented and transformative learning’ (Unesco 2014: 12). An international collaborative group–ESD Expert-Net–highlighted the ‘active’ element of ESD arguing that ‘action’ or ‘doing’ elements of learning have traditionally been neglected, and that if ESD practice is to address local and global challenges ‘a strong action component’ is needed (Hoffmann and Rajeswari nd: 9). The notion of ‘active learning’has been of central interest in the Fundisa for Change project. This chapter describes its trajectory of development and use in South African ESD by outlining core features and principles for active learning. This is with a view to positioning the further chapters in this section of the book in relation to national and international research that has influenced the approach of Fundisa for Change. The chapter also serves to inform international interests in active learning.
- Full Text:
Thien-2-yl substituted chlorins as photosensitizers for photodynamic therapy and photodynamic antimicrobial chemotherapy
- Authors: Babu, Balaji , Sindelo, Azole , Mack, John , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190578 , vital:45007 , xlink:href="https://doi.org/10.1016/j.dyepig.2020.108886"
- Description: The synthesis and characterization of meso-tetra(thien-2-yl)chlorin (1) and meso-tetra(5-bromothien-2-yl)chlorin (2) is reported. These dyes have red-shifted absorption maxima compared to those of the analogous meso-tetraphenylchlorin (3). 1 and 2 have Q bands at 660 and 664 nm, respectively, singlet oxygen quantum yields of 0.60 and 0.64 and exhibit good photostability. The triplet states were found to have lifetimes of 8.6 μs in N2 purged DMF. Time-dependent cellular uptake of chlorins reached a maximum in MCF-7 cancer cells after 12 h. Upon irradiation with a Thorlabs M660L3 LED (280 mW cm−2), 2 exhibited better photocytotoxicity with an IC50 value of 2.7 μM against MCF-7 cells. The 2ʹ,7ʹ-dichlorodihydrofluorescein diacetate (DCFDA) assay provided evidence for intracellular generation of reactive oxygen species. Photodynamic inactivation of bacteria by the chlorins was also studied. 2 exhibits better activity with log reduction values of 7.42 and 8.34 towards Staphylococcus aureus and Escherichia coli, respectively, under illumination for 60 min at 660 nm with a Thorlabs M660L3 LED (280 mW cm−2). These results demonstrate that 2 is a promising candidate for future in vivo experiments and merits further in-depth investigation.
- Full Text:
Thirty years of Male Daughters, Female Husbands
- Authors: Magadla, Siphokazi , Magoqwana, Babalwa , Motsemme, Nthabiseng
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298685 , vital:57727 , xlink:href="https://doi.org/10.1080/02589001.2021.1926442"
- Description: This paper examines the legacy of Ifi Amadiume's Male Daughters, Female Husbands: Gender and Sex in an African Society (1987) to African gender theorisation three decades after its publication. We argue that Amadiume's detailed ethnography of the Nnobi society provides an example of what can be achieved when African scholars centre local histories, languages, and kinship ties to provide contextualised understandings of sex and gender. In southern African societies, we assess the ways in which gender fluidity, drawing from local languages, age, seniority and lineage do not strictly fix sex to gender, thus providing possibilities for flexible gender structures that allow women to access institutions of power through the lineage as first daughters (umafungwashe) and wives, among others. We further examine the ways conservative patriarchal discourses continue distorting African cultures and traditions, thus undermining women's rights and access to social, cultural, economic and political power. We argue that current Eurocentric attempts that aim to delink sex and gender do not move us beyond the universalised binaries of gender and sex. Through revisiting local social and linguistic histories that practised gender fluidity and tolerance, we can also begin to challenge the conservative attitudes towards the LGBTQIA+ communities. Given the continued sexual and gender diversities that are being challenged daily in the African continent, it is timely that we revisit the historical meanings along with their contemporary implications for sexual citizenship and gendered power relations today.
- Full Text:
Three new biological control programmes for South Africa: Brazilian pepper, Tamarix and Tradescantia
- Authors: Byrne, Marcus J , Mayonde, Samalesu , Venter, Nic , Chidawanyika, Frank , Zachariades, Coates , Martin, Grant D
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414490 , vital:71152 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Three weed biological control (biocontrol) programmes are described, all of which are considered to be ‘transfer projects’ that were initiated elsewhere, and on which South Africa has piggybacked its biocontrol efforts. Using knowledge and expertise from international collaborators, South African weed researchers are following a long tradition of transfer projects, which has been a largely successful and practical approach to biocontrol. Two Brazilian weeds, the Brazilian pepper tree Schinus terebinthifolia and the spiderwort Tradescantia fluminensis are being targeted, along with the Old-World trees Tamarix ramosissima and T. chinensis. The potential biocontrol agents are described and ranked for the two trees according to what has been discovered elsewhere, while the agent already released against T. fluminensis is rated (as poor), and other potential agents are considered. The addition of molecular techniques, climate matching and remote sensing in transfer projects can increase the chance of successful biocontrol and the inclusion of these techniques in the three new programmes is discussed. Transfer projects are a cost-effective and pragmatic way to pick winning biocontrol programmes.
- Full Text:
Top-Down Synthesis of a Lamivudine-Zidovudine Nano Co-Crystal
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183172 , vital:43918 , xlink:href="https://doi.org/10.3390/cryst11010033"
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiretroviral agents used to manage HIV/AIDS infection. A wet media milling top-down approach was used to develop and produce nano co-crystals of 3TC and AZT. Micro co-crystals were prepared by solvent evaporation and subsequently milled in the presence of two surfactants, viz., sodium lauryl sulfate (SLS) and α-tocopheryl polyethylene glycol succinate 1000 (TPGS 1000). Optimisation was undertaken using design of experiments (DoE) and response surface methodology (RSM) to establish and identify parameters that may affect the manufacturing of nano co-crystals. The impact of SLS and TPGS 1000 concentration, milling time, and number of units of milling medium on the manufacturing of nano co-crystals, was investigated. The critical quality attributes (CQA) monitored were particle size (PS), Zeta potential (ZP), and polydispersity index (PDI). Powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, transmission electron microscopy, energy dispersive X-ray spectroscopy scanning electron microscopy, and cytotoxicity assays were used for additional characterization of the optimised nano co-crystal. The mean PS, PDI, and ZP of the optimised top-down nanocrystal were 271.0 ± 92.0 nm, 0.467 ± 0.073, and −41.9 ± 3.94 mV, respectively. In conclusion, a simple, inexpensive, rapid, and precise method of nano co-crystal manufacturing was developed, validated, and optimised using DoE and RSM, and the final product exhibited the target CQA.
- Full Text:
Towards The Quantification Of The Historical And Future Water Resources Of The Limpopo River
- Authors: Kapangaziwiri, Evison , Kahinda, Jean-Marc M , Oosthuizen, Nadia , Mvandaba, Vuyelwa , Hobbs, Philip , Hughes, Denis A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438349 , vital:73453 , ISBN 978-0-6392-0303-4 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2439_final.pdf
- Description: The complexity of current water resource management poses many challenges. Wa-ter managers must solve a range of interrelated dilemmas – such as balancing quan-tity and quality, mitigating the effects of flooding and drought, and maintaining bio-diversity, ecological functions, and services. Sustainable water resource manage-ment, planning, and development requires reliable quantification of the amount, distribution, and quality of water within river basins. With the demand for water resources rapidly growing across the globe, there is also an urgent need for accu-rate monitoring, forecasting and simulation of hydrologic variables – especially in major (often transboundary) river basins such as the Limpopo – not only for optimal water resources management but more compellingly, also for water security, food security, power generation, and economic development. However, the available data are frequently far from sufficient – in terms of availability, accuracy, and spa-tial/temporal resolution – for the understanding of both natural and anthropogenic processes (and their complex linkages) in a river basin. Such challenges also make it very difficult to use the data for the practical application of estimation of water resources availability.
- Full Text:
Turn-on detection of cysteine by a donor-acceptor type quinoline fluorophore: Exploring the sensing strategy and performance in bioimaging
- Authors: Muthusamy, Selvaraj , Zhao, Long , Rajalakshmi, Kanagaraj , Zhu, Dongwei , Soy, Rodah , Mack, John , Nyokong, Tebello , Wang, Shengjun , Lee, Kang-Bong , Zhu, Weihua
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185644 , vital:44406 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109556"
- Description: Tracking the biothiol cysteine (Cys) in living systems is a significant responsibility to balance the redox environment and oxidative stress. A quinoline-7-nitro-1,2,3-benzoxadiazole (Q-NBD) fluorophore has been synthesized and characterized towards examination of Cys. The probe forms a quinoline-substituted phenol (Q-Ph-OH) after thiolysis of the NBD ether bond, leading to an increase of fluorescence at green channel. The turn-on sensing mechanism originates from the change in intramolecular charge transfer (ICT-OFF) along with an aggregation-induced emission (AIE) as suggested by spectroscopy measurements in solutions, time-dependent density-functional theory (TD-DFT) calculations and 1H NMR titration examination. Importantly, Q-NBD exhibited great sensitivity with a low limit of detection value of 89.5 nM and remarkable selectivity in various biothiols towards Cys. The sensor probe was successfully used for detecting both endogenous and exogenous Cys in PC3 living cells and spiked Cys in human urine samples.
- Full Text:
Ultrasound-Triggered Release of 5-Fluorouracil from Soy Lecithin Echogenic Liposomes
- Authors: Ezekiel, Charles I , Bapolisi, Alain M , Walker, Roderick B , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183115 , vital:43913 , xlink:href="https://doi.org/10.3390/pharmaceutics13060821"
- Description: Colorectal cancer is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) has been the major chemotherapeutic treatment for colorectal cancer patients. However, the efficacy of 5-FU is limited by drug resistance, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying the need for improvement of the therapeutic index. In this study, the effects of ultrasound on echogenic 5-FU encapsulated crude soy liposomes were investigated for their potential to address these challenges. Liposomes were prepared by thin-film hydration using crude soy lecithin and cholesterol. Argon gas was entrapped in the liposomes for sonosensitivity (that is, responsiveness to ultrasound). The nanoparticles were characterized for particle size and morphology. The physicochemical properties were also evaluated using differential scanning calorimetry, Fourier transform infrared and X-ray diffraction. The release profile of 5-FU was assessed with and without 20 kHz low-frequency ultrasound waves at various amplitudes and exposure times. The result reveal that 5-FU-loaded liposomes were spherical with an encapsulation efficiency of approximately 60%. Approximately 65% of 5-FU was released at the highest amplitude and exposure time was investigated. The results are encouraging for the stimulated and controlled release of 5-FU for the management of colorectal cancer.
- Full Text:
Understanding the food crises in southern Africa and the ways of transitioning the food systems to combat hunger
- Authors: Chakona, Gamuchirai , Mushangai, Dandira
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , working paper
- Identifier: http://hdl.handle.net/10962/433956 , vital:73014 , ISBN working paper
- Description: Globally, almost one billion people are estimated to face hunger on a regular basis (Poppy et al., 2014) and more than two billion people suffer from micronutrient deficiencies (Barrett, 2010; FAO et al. 2020). The number of food-insecure people has been on the rise with subSaharan Africa having the greatest number of individuals who are both hungry (about 237 million people) and malnourished (almost 23% of the population) (FAO, 2018). Beyond hunger, FAO et al. (2020) noted that a growing number of people have had to reduce the quantity and quality of the food they consume. This makes it almost impossible to have a world with zero hunger by 2030 and achieve SDG 2 target 2.1 of ensuring access to safe, nutritious and sufficient food for all people and target 2.2 of eradicating all forms of malnutrition (UN 2015). Most governments globally have pledged to eradicate hunger in their nations by 2030, and one of their solutions is to increase agricultural productivity to meet the needs of all their people. However, Poppy et al. (2014) argued that increased yields and food supplies do not assure food security for all as some poorer societies and communities may not have access to sufficient quantity or quality food (Iram and Butt, 2004), which is a challenge in many African communities, especially in South Africa. This highlights the complexity of the food system within many countries.
- Full Text:
Unlocking the Diversity of Pyrroloiminoquinones Produced by Latrunculid Sponge Species
- Authors: Kalinski, Jarmo-Charles J , Krause, Rui W M , Parker-Nance, Shirley , Waterworth, Samantha C , Dorrington, Rosemary A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191802 , vital:45165 , xlink:href="https://doi.org/10.3390/md19020068"
- Description: Sponges of the Latrunculiidae family produce bioactive pyrroloiminoquinone alkaloids including makaluvamines, discorhabdins, and tsitsikammamines. The aim of this study was to use LC-ESI-MS/MS-driven molecular networking to characterize the pyrroloiminoquinone secondary metabolites produced by six latrunculid species. These are Tsitsikamma favus, Tsitsikamma pedunculata, Cyclacanthia bellae, and Latrunculia apicalis as well as the recently discovered species, Tsitsikamma nguni and Tsitsikamma michaeli. Organic extracts of 43 sponges were analyzed, revealing distinct species-specific chemical profiles. More than 200 known and unknown putative pyrroloiminoquinones and related compounds were detected, including unprecedented makaluvamine-discorhabdin adducts and hydroxylated discorhabdin I derivatives. The chemical profiles of the new species T. nguni closely resembled those of the known T. favus (chemotype I), but with a higher abundance of tsitsikammamines vs. discorhabdins. T. michaeli sponges displayed two distinct chemical profiles, either producing mostly the same discorhabdins as T. favus (chemotype I) or non- or monobrominated, hydroxylated discorhabdins. C. bellae and L. apicalis produced similar pyrroloiminoquinone chemistry to one another, characterized by sulfur-containing discorhabdins and related adducts and oligomers. This study highlights the variability of pyrroloiminoquinone production by latrunculid species, identifies novel isolation targets, and offers fundamental insights into the collision-induced dissociation of pyrroloiminoquinones.
- Full Text:
Urban ecology of the Global South
- Authors: du Toit, Marie J , Shackleton, Charlie M , Cilliers, Sarel S , Davoren, Elandre
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433728 , vital:72997 , ISBN 978-3-030-67650-6 , https://doi.org/10.1007/978-3-030-67650-6
- Description: Against the background of unprecedented rates of urbanisation in the Global South, leading to massive social, economic and environmental transformations, this book engages with the dire need to understand the ecology of such settings as the foundation for fostering sustainable and resilient human settlements in contexts that are very different to the Global North. It does so by bringing together scholars from around the world, drawing together research and case studies from across the Global South to illustrate, in an interdisciplinary and comprehensive fashion, the ecology of towns and cities in the Global South. Framed using a social-ecological systems lens, it provides the reader with an in-depth analysis and understanding of the ecological dynamics and ecosystem services and disservices within the complex and rapidly changing towns and cities of the Global South, a region with currently scarce representation in most of the urban ecology literature. As such the book makes a call for greater geographical balance in urban ecology research leading towards a more global understanding and frameworks. The book embraces the complexity of these rapid transformations for ecological and environmental management and how the ecosystems and the benefits they provide shape local ecologies, livelihood opportunities and human wellbeing, and how such knowledge can be mobilised towards improved urban design and management and thus urban sustainability.
- Full Text:
Urban ecosystem disservices in the Global South
- Authors: Davoren, Elandre , Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433780 , vital:73000 , ISBN 978-3-030-67650-6 , https://doi.org/10.1007/978-3-030-67650-6_11
- Description: As much as people benefit from the ecosystem services provided by nature, ecosystem disservices also impact daily lives. This is especially true for many urban communities in the Global South due to (1) the often greater diversity of ecosystem disservices and (2) higher vulnerabilities, which together can lead to greater impacts of ecosystem disservices in many Global South settings. This chapter provides an overview of the current understandings of urban ecosystem disservices and their assessment and management with an emphasis on the Global South, albeit with reference to the Global North where useful. This overview reveals a lack of detailed and systematic empirical research on urban ecosystem disservices generally, but even more so in the Global South, despite the greater diversity and vulnerability in Global South settings. This needs to be acknowledged in urban ecology framings of urban dynamics in the Global South and translated into better integration of both ecosystem services and disservices within common research, policy or management frameworks. It is only through such integration that appropriate context-relevant policy directions and management options can be identified, thereby promoting the wellbeing of urban citizens in the Global South.
- Full Text:
Urban green infrastructure for poverty alleviation: evidence synthesis and conceptual considerations
- Authors: Shackleton, Charlie M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/401383 , vital:69730 , xlink:href="https://doi.org/10.3389/frsc.2021.710549"
- Description: The multiple benefits of urban green infrastructure (UGI) that support sustainable cities are increasingly acknowledged, and yet the bulk of research over the past decade or so has focused on only a small subset of the numerous benefits, notably recreation, physical and mental health, and regulating services. In contrast, there is very little information on the contribution of UGI to several of the other Sustainable Development Goals (SDGs), and in particular SDG 1 of reducing poverty, despite the pervasiveness of poverty globally. This paper considers the diverse direct and indirect ways in which UGI can contribute to poverty alleviation, drawing on the limited evidence from various regions of the world. The direct links between UGI and poverty alleviation is via three means, namely provision of (1) consumptive or provisioning goods such as wild foods and firewood, (2) employment in UGI development, maintenance, and restoration, and (3) land for urban agriculture, income generation and dwelling. There are also a number of indirect links such as cash savings, improved physical and mental health, improved social networks, improved educational outcomes, and regulation of potential natural disasters. However, the commonly unequal distribution of UGI within and between cities means that the poverty alleviation potential and benefits are inequitably distributed, often against those who are most in need of them, i.e., the urban poor. This demands greater attention to promoting the equitable distribution and quality of UGI and mainstreaming of UGI into poverty reduction strategies and programmes and vice versa, as well as greater examination of the links between UGI and poverty alleviation in a greater range of contexts.
- Full Text: