Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa
- Authors: Adjei, Anane Yaw , Apalata, Teke , Vasaikar, Sandeep , Okuthe, Grace Emily , Songca, Sandile
- Date: 2019
- Subjects: Acinetobacter baumannii , Carbapenemase-encoding genes , Multidrug-resistance , ISAba1 , intI1
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/11260/2409 , vital:41457 , https://doi.org/10.1016/j.bjid.2019.09.004
- Description: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagarTM Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.
- Full Text:
- Date Issued: 2019
Privately protected areas provide key opportunities for the regional persistence of large- and medium-sized mammals
- Authors: Clements, Hayley S , Kerley, Graham I H , Cumming, Graeme S , de Vos, Alta , Cook, Carly N
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416383 , vital:71344 , xlink:href="https://doi.org/10.1111/1365-2664.13300"
- Description: Biodiversity conservation relies heavily on protected areas (PAs). However, in locations that are desirable for agriculture, industry, or human habitation (e.g., low -land habitats on fertile soils, coastal zones), land is often privately owned and state-owned PAs tend to be under-represented. Despite the potentially disproportionate contribution that privately protected areas (PPAs) could make to representing biodiversity and supporting its persistence across regional PA estates, this contribution is poorly understood.
- Full Text:
- Date Issued: 2019
Risk assessment to interpret the physiological host range of Hydrellia egeriae, a biocontrol agent for Egeria densa
- Authors: Smith, Rosali , Mangan, Rosie , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418053 , vital:71504 , xlink:href="https://doi.org/10.1007/s10526-019-09942-4"
- Description: Egeria densa Planchon (Hydrocharitaceae) is a submerged macrophyte native to South America. It forms part of a new suite of invasive aquatic plants that has benefited from open nutrient-rich freshwater systems following the successful biological control of floating aquatic plants in South Africa. The specificity of the leaf-mining fly, Hydrellia egeriae Rodrigues (Diptera: Ephydridae) was tested, using traditional laboratory host-specificity testing (i.e., no-choice and paired choice). Only one non-target species, Lagarosiphon major Deeming (Hydrocharitaceae) supported larval development during pair-choice tests. In order to avoid the rejection of a safe and potentially effective agent, continuation (i.e., multiple generations) tests were conducted to measure the ability of the non-target species to nutritionally support a population indefinitely. None of these species could sustain a viable agent population for more than three generations. Laboratory host-specificity tests are limited as they exempt certain insect-host behaviours. To enhance the interpretation of host-specificity results, a risk assessment was conducted using agent preference (i.e., choice tests) and performance (i.e., choice and continuation tests) results. The feeding and reproductive risk that H. egeriae poses to non-target species is below 2%. Based on these findings, permission for its release in South Africa has been obtained.
- Full Text:
- Date Issued: 2019
The dynamics of proclaimed privately protected areas in South Africa over 83 years
- Authors: de Vos, Alta , Clements, Hayley S , Biggs, Duan , Cumming, Graeme S
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433223 , vital:72952 , xlink:href="https://doi.org/10.1111/conl.12644"
- Description: Views that protected area (PA) expansion relies predominantly on land purchased by government are increasingly being challenged. The inclusion of privately owned PAs (PPAs) in national conservation strategies is now commonplace, but little is known about their long-term persistence and how it compares to that of state-owned PAs. We undertook the first long-term assessment of the dynamics of a national system of terrestrial PPAs, assessing its growth, as well as its resilience to downgrading, downsizing, and degazettement (PADDD). Between 1926 and 2018, 6.2% of all private nature reserves established in South Africa were degazetted, compared to 2.2% of state-owned nature reserves. Privately owned PA growth exceeded that of state-owned PAs. Trends in PA establishment differed between privately owned and state-owned PAs, reflecting different legislative, political, and economic events. Our findings highlight the value of enabling legislative environments to facilitate PPA establishment, and demonstrate the potential of PPAs as a long-term conservation strategy.
- Full Text:
- Date Issued: 2019
Thermal plasticity and microevolution enhance establishment success and persistence of a water hyacinth biological control agent
- Authors: Griffith, Tamzin C , Paterson, Iain D , Owen, Candice A , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424866 , vital:72190 , xlink:href="https://doi.org/10.1111/eea.12814"
- Description: Aspects of the thermal physiology of the water hyacinth biological control agent Eccritotarsus catarinensis Carvalho (Hemiptera: Miridae) have been extensively investigated over the past 20 years to understand and improve post-release establishment in the field. Thermal physiology studies predicted that the agent would not establish at a number of cold sites in South Africa, where it has nonetheless subsequently established and thrived. Recently, studies have begun to incorporate the plastic nature of insect thermal physiology into models of agent establishment. This study determined whether season and locality influenced the thermal physiology of two field populations of E. catarinensis, one collected from the hottest site where the agent has established in South Africa, and one from the coldest site. The thermal physiology of E. catarinensis was significantly influenced by season and site, demonstrating a degree of phenotypic plasticity, and that some post-release local adaptation to climatic conditions has occurred through microevolution. We then determined whether cold acclimation under laboratory conditions was possible. Successfully cold-acclimated E. catarinensis had a significantly lower critical thermal minimum (CTmin) compared to the field cold-acclimated population. This suggests that cold acclimation of agents could be conducted in the laboratory before future releases to improve their cold tolerance, thereby increasing their chance of establishment at cold sites and allowing further adaptation to colder climates to occur in the field. Although the thermal tolerance of E. catarinensis is limited by local adaptations to climatic conditions in the native range, the plastic nature of the insect's thermal physiology has allowed it to survive in the very different climatic conditions of the introduced range, and there has been some adaptive change to the insect's thermal tolerance since establishment. This study highlights the importance of plasticity and microevolutionary processes in the success of biological control agents under the novel climatic conditions in the introduced range.
- Full Text:
- Date Issued: 2019
Un-functionalized gold nanoparticles as a simple colorimetric probe for sensitive and selective detection of dopamine
- Authors: Khanyile, Nokuthula , Krause, Rui W M , Vilakazi, Sibulelo , Torto, Nelson
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195048 , vital:45522 , xlink:href="http://dx.doi.org/10.17159/0379-4350/2019/v72a27"
- Description: A dopamine (DA) colorimetric probe based on the growth and aggregation of un-functionalized gold nanoparticles (AuNPs) is reported. Upon addition of AuNPs to dopamine at various concentrations, the shape, size and colour change of the nanoparticles results in spectral shifts to higher wavelengths and hence colour change is the mode of detection. The colour change can be easily observed by the naked eye from as low as 5.0 nM DA, even under sub-optimal conditions. Under optimal pH conditions the calculated limit of detection was 2.5 nM (3σ). The probe was successfully applied to whole blood sample and showed good selectivity and sensitivity towards DA. The simple, sensitive and selective probe could be an excellent alternative for on-site and immediate detection of DA without the use of instrumentation and would thus be useful for rapid diagnostic applications.
- Full Text:
- Date Issued: 2019
Cloud computing adoption: Strategies for Sub-Saharan Africa SMEs for enhancing competitiveness
- Authors: Adane, Martin
- Date: 2018
- Subjects: business intelligence small businesses business planning Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6862 , vital:51101 , xlink:href="https://doi.org/10.1080/20421338.2018.1439288"
- Description: Small and medium-sized enterprises (SMEs) need to design and implement strategies for adopting new technologies as a competitive tool for maintaining their competitive advantage and cloud computing is at its peak. Since its emergence, there has been a surge in the adoption of cloud computing with research into its adoption primarily concentrated on bigger firms. However, a major characteristic of cloud computing is the anticipated possibilities it holds for SMEs. This paper primarily explores cloud computing adoption strategies for SMEs operating in Sub-Saharan Africa. Using a mixed method approach, a sample of 261 respondents and 11 SMEs was respectively used for the quantitative and qualitative stages of the research. The results reveal that, even though SMEs have their unique expectations for adopting cloud computing, they were of the consensus that elements of an adoption strategy should include adoption goals, a roadmap, and considerations. The paper makes specific recommendations to SMEs to develop adoption strategies that meet their specific needs if they expect cloud computing to play a stronger role to support more strategic initiatives to grow their businesses and improve customer experience.
- Full Text:
- Date Issued: 2018
Contesting sexual violence policies in higher education: the case of Rhodes University
- Authors: Macleod, Catriona I , Böhmke, Werner , Barker, Kim , Mavuso, Jabulile M-J J , Chiweshe, Malvern T
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444275 , vital:74212 , xlink:href="https://www.emerald.com/insight/content/doi/10.1108/JACPR-05-2017-0295/full/html"
- Description: – In April 2016, students at Rhodes University brought the institution to a standstill as they protested the University’s sexual violence policies and procedures, as well as the “rape culture” that pervades social structures. In response, a Sexual Violence Task Team (SVTT) was formed in an open, participatory, and transparent process. Members of the University community were invited to comment on drafts of the SVTT document. The purpose of this paper is to outline the contestations – arising from both the establishment of the task team and the inputs from University members to drafts of the document – that surfaced concerning managing sexual violence on campuses and sexual offences policies.
- Full Text:
- Date Issued: 2018
Influence of land cover, proximity to streams and household topographical location on flooding impact in informal settlements in the Eastern Cape, South Africa
- Authors: Dalu, Mwazvita T B , Shackleton, Charlie M , Dalu, Tatenda
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182089 , vital:43799 , xlink:href="https://doi.org/10.1016/j.ijdrr.2017.12.009"
- Description: Patterns of land use, household topographical location and state of natural vegetation influence the spatial distribution of flooding impact. Using field observations and GIS mapping techniques, we investigated how landscape factors influenced structural flooding impact in informal settlements. This study was carried out in the informal settlements of the Eastern Cape Province of South Africa, after the October 2012 floods. Increasing slope significantly raised the probability and level of damage by at least 30% in five of the seven sites, whereas proximity to river and wetlands (more than 100 m) was significant in only two of the sites and at lower levels. Multi-regression analysis highlighted that land cover, proximity to streams and household topographical location influenced the impact of flooding on housing structures. We found that the impact on housing structures in informal settlements during the floods were significantly influenced by their proximity to water bodies, slope factor and patterns of land cover.
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- Date Issued: 2018
Investigation of molecular mechanism of recognition between citral and MARK4: A newer therapeutic approach to attenuate cancer cell progression
- Authors: Naz, Farha , Khan, Faez I , Mohammad, Taj , Khan, Parvez , Manzoor, Saaliqa , Hasan, Gulam M , Lobb, Kevin A , Luqman, Suaib , Ahmad, Faizan , Hassan, M Imtaiyaz
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447967 , vital:74687 , xlink:href="https://doi.org/10.1016/j.ijbiomac.2017.10.143"
- Description: Microtubule affinity regulating kinase 4 (MARK4) is a member of AMP-activated protein kinase, found to be involved in apoptosis, inflammation and many other regulatory pathways. Since, its aberrant expression is directly associated with the cell cycle and thus cancer. Therefore, MARK4 is being considered as a potential drug target for cancer therapy. Here, we investigated the mechanism of inhibition of MARK4 activity by citral. Docking studies suggested that citral effectively binds to the active site cavity, and complex is stabilized by several interactions. We further performed molecular dynamics simulation of MARK4-citral complex under explicit water condition for 100 ns and observed that binding of citral to MARK4 was quite stable. Fluorescence binding studies suggested that citral strongly binds to MARK4 and thereby inhibits its enzyme activity which was measured by the kinase inhibition assay. We further performed MTT assay and observed that citral inhibits proliferation of breast cancer cell line MCF-7. This work provides a newer insight into the use of citral as novel cancer therapeutics through the MARK4 inhibition. Results may be employed to design novel therapeutic molecule using citral as a scaffold for MARK4 inhibition to fight related diseases.
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- Date Issued: 2018
Lesbian, gay, and bisexual (LGB) people's experiences of nursing health care: An emancipatory nursing practice integrative review
- Authors: Nhamo-Murire, Mercy , Macleod, Catriona I
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444357 , vital:74222 , xlink:href="https://doi.org/10.1111/ijn.12606"
- Description: To review current research on lesbian, gay, and bisexual (LGB) individuals' experience of nursing services from an emancipatory nursing practice framework.
- Full Text:
- Date Issued: 2018
Morphological, genetic and biological characterisation of a novel alphabaculovirus isolated from Cryptophlebia peltastica (Lepidoptera: Tortricidae)
- Authors: Marsberg, Tamryn , Jukes, Michael , Krejmer-Rabalska, Martyna , Rabalski, Lukasz , Knox, Caroline M , Moore, Sean D , Hill, Martin P , Szewczyk, Boguslaw
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419330 , vital:71635 , xlink:href="https://doi.org/10.1016/j.jip.2018.08.006"
- Description: Cryptophlebia peltastica is an agricultural pest of litchis and macadamias in South Africa with phytosanitary status for certain markets. Current control methods rely on chemical, cultural and classical biological control. However, a microbial control option has not been developed. An Alphabaculovirus from C. peltastica was recovered from a laboratory reared colony and morphologically characterised by transmission electron microscopy (TEM). Analysis of occlusion bodies indicated a single NPV (SNPV) varying in size from 421 to 1263 nm. PCR amplification and sequencing of the polh gene region using universal primers followed by BLAST analysis revealed a 93% similarity to a partial polh gene sequence from Epinotia granitalis NPV. Further genetic characterisation involving single restriction endonuclease (REN) digestion of genomic DNA was carried out to generate profiles for comparison against other baculovirus species and potential new isolates of the same virus. The complete genome of the virus was sequenced, assembled and analysed for a more comprehensive genetic analysis. The genome was 115 728 base pairs (bp) in length with a GC content of 37.2%. A total of 126 open reading frames (ORFs) were identified with minimal overlap and no preference in orientation. Bioassays were used to determine the virulence of the NPV against C. peltastica. The NPV was virulent against C. peltastica with an LC50 value of 6.46 × 103 OBs/ml and an LC90 value of 2.46 × 105 OBs/ml, and time mortality ranging between 76.32 h and 93.49 h. This is the first study to describe the isolation and genetic characterisation of a novel SNPV from C. peltastica, which has potential for development into a biopesticide for the control of this pest in South Africa.
- Full Text:
- Date Issued: 2018
Novel nano-dyad of homoleptic sandwich-type phthalocyanines with nitrogen doped graphene quantum dots for nonlinear optics
- Authors: Oluwole, David O , Nwaji, Njemuwa , Nene, Lindokuhle C , Mokone, Lesedi , Dube, Edith , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233386 , vital:50086 , xlink:href="https://doi.org/10.1039/C8NJ01707G"
- Description: The syntheses of neodymium(III) 2,9,16,23-tetrakis-(2,6-di-tert-butyl-4-methylphenoxy)phthalocyanine (2), bis europium(III) 2,9,16,23-tetrakis-(2,6-di-tert-butyl-4-methylphenoxy)phthalocyanine (3), bis dysprosium(III) 2,9,16,23-tetrakis-(2,6-di-tert-butyl-4-methylphenoxy)phthalocyanine (4) and their conjugated analogues with nitrogen doped quantum dots (NGQDs) are reported herein. The optical nonlinearity of the sandwich-type phthalocyanine complexes and their conjugates with NGQDs were studied in dimethyl sulfoxide using the open aperture Z-scan technique at an excitation wavelength of 532 nm with a 10 ns pulse. The nonlinear absorption coefficient (βeff) value of the samples ranges from 15 cm GW−1 to 89.6 cm GW−1. Complex 4 and its conjugates afforded a strong optical limiting behaviour compared to the other samples. These fabricated complexes and their conjugates with NGQDs could serve as a plausible nonlinear optical (NLO) material due to their fascinating NLO properties.
- Full Text:
- Date Issued: 2018
Optimizing phthalocyanine based dye-sensitized solar cells: The role of reduced graphene oxide
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Fomo, Gertrude , Oluwole, David O , Sindelo, Azole , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187770 , vital:44695 , xlink:href="https://doi.org/10.1016/j.synthmet.2018.10.021"
- Description: Dye-sensitized solar cells (DSSC) were fabricated by incorporating graphene materials as catalysts at the counter electrode. Platinum was also used as a catalyst for comparison purposes. Different phthalocyanines: hydroxyl indium tetracarboxyphenoxy phthalocyanine (1), chloro indium octacarboxy phthalocyanine (2) and dibenzoic acid silicon phthalocyanine (3) were used as dyes. Complex 3 gave the highest power conversion efficiency (η) of 3.19% when using nitrogen doped reduced graphene oxide nanosheets (NrGONS) as a catalyst at the counter electrode, and TiO2 containing rGONS at the anode. The value is close to 3.8% obtained when using Pt catalyst instead of NrGONS at the cathode, thus confirming that NrGONS is a promising candidate to replace the more expensive Pt. The study also shows that placing rGONS on both the anode and cathode improves efficiency.
- Full Text:
- Date Issued: 2018
Price determination of non-timber forest products in different areas of South Africa
- Authors: Mugido, Worship , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179825 , vital:43192 , xlink:href="https://doi.org/10.1016/j.ecolecon.2017.12.010"
- Description: A wide variety of factors can influence the price determination of non-timber forest products (NTFPs) in individual markets. However, there is little understanding of differences across multiple markets within a uniform macro context, or how they might vary between different types of NTFPs. Therefore, this study sought to determine the factors and rationale behind the setting of prices for selected NTFPs in 15 different areas of South Africa. The results showed that the pricing factors considered by sellers when setting the prices of NTFP varied with the type of NTFP being sold, type of market (home markets or urban markets) and the method used by the seller to procure the stock. Overall, transport costs, stock price, profit margin, time taken to collect or produce the product and market price were the widely used factors to determine prices for NTFPs. The marked variation in both markets and products show that there was no formal or certain price setting mechanism that was used by NTFP sellers establish the market prices of NTFPs, with price discovery being the most widespread.
- Full Text:
- Date Issued: 2018
The distribution and abundance of the stem-galling fly, Cecidochares connexa (Macquart)(Diptera: Tephritidae), a biological control agent of Chromolaena odorata (L.)(Asteraceae), in Ghana
- Authors: Aigbedion-Atalor, Pascal O , Wilson, David D , Eziah, Vincent Y , Day, Michael D , Paterson, Iain D
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407074 , vital:70334 , xlink:href="https://hdl.handle.net/10520/EJC-113112d1da"
- Description: Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae: Eupatorieae) is one of the worst invasive weeds in West Africa, and a serious biotic threat to food security. The stem-galling fly, Cecidochares connexa (Macquart) (Diptera: Tephritidae), a biological control agent for C. odorata, was released in the Ivory Coast in 2003 and first detected in Ghana in 2014. The spatiotemporal distribution and abundance of C. connexa in Ghana was determined by country-wide surveys from 2015 to 2016. Galls were found in varying densities across Ghana but gall densities were consistently low east of Lake Volta. A limited survey conducted in the extreme west of Togo in 2016, found the gall fly also in low numbers. There was a significant correlation between C. connexa gall densities and the distance from the release sites in the Ivory Coast. The distribution and abundance of the gall fly in Ghana could be explained by its spread from the original release sites over time and/or the much drier conditions east of Lake Volta. Cecidochares connexa has dispersed a distance of about 1000 km over a 10-year period and, while there is some evidence that the gall fly is still dispersing towards the east, its range and population size could be limited by the dry climatic conditions in the east of Ghana and in Togo. Actively redistributing the agent over this dry corridor to the more humid and higher rainfall areas of Nigeria, may result in the spread of this agent through the rest of West and Central Africa, thereby aiding the control of C. odorata in the region.
- Full Text:
- Date Issued: 2018
The photophysicochemical behavior of symmetric and asymmetric zinc phthalocyanines, surface assembled onto gold nanotriangles
- Authors: Dube, Edith , Nwaji, Njemuwa , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233310 , vital:50079 , xlink:href="https://doi.org/10.1039/C8NJ02746C"
- Description: The synthesis of a novel asymmetric phthalocyanine, (4-(4-(benzo[d]thiazol-2-yl)phenoxy)-2,10,17-tris(4-(2-carboxyethyl)phenoxy)phthalocyaninatol)zinc(II), complex 3, is reported. Complex 3 together with the previously reported complexes tetrakis[(benzo[d]thiazol-2-yl phenoxy)phthalocyaninato]zinc(II) (4) and 3-(4-((3,17,23-tris(4-(benzo[d]thiazol-2-yl)phenoxy)phthalocyaninatol)oxy)phenyl)propanoic acid zinc(II) (5), were linked to gold nanotriangles (AuNTs) through S–Au/Au–N self-assembly to afford the conjugates (3-AuNTs, 4-AuNTs and 5-AuNTs). The photophysicochemical behaviour of the complexes and their conjugates were studied. The asymmetric complexes 3 and 5, displayed improved triplet and singlet oxygen quantum yields compared to the symmetric complex 4, while all conjugates displayed improved triplet and singlet oxygen quantum yields compared to their respective complexes alone. The complexes and their conjugates could serve as good candidates for photodynamic therapy.
- Full Text:
- Date Issued: 2018
The potential use of natural resources in urban informal settlements as substitutes for financial capital during flooding emergencies
- Authors: Dalu, Mwazvita T B , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179814 , vital:43191 , xlink:href="https://doi.org/10.1016/j.pce.2018.03.002"
- Description: Rapid and widespread land cover change and the subsequent loss of the buffering capacity provided by healthy ecosystems against natural hazards has resulted in increased vulnerability to natural hazards. There is an insufficient understanding of the natural resources contribution to the resilience of poor urban communities living in informal settlements and the financial implications thereof. Thus, household strategies used to recover from the October 2012 flood shock were investigated within the informal settlements of three small South African towns using questionnaires. Within the vulnerability paradigm and the sustainable livelihood framework, the study also quantified and evaluated the relative contribution of natural resources to recovery strategies and the impacts on household financial capital. We found that natural resources contributed up to 70% to recovery of households from the flood shock, most of this being to reconstruct housing structures after the flood. Factors such as household head education level, household income, kinship level, the extent of property damage and the cost associated with property rehabilitation significantly influenced the uptake of natural resources in recovery from floods, and this was variable among settlements and towns. The main findings showed that natural resources reduced household vulnerability of urban informal settlements by providing an emergency-net function that substitutes financial capital. Their inclusion in disaster management plans and responses has the potential to contribute to the sustainable livelihoods of the urban poor in the Eastern Cape, South Africa.
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- Date Issued: 2018
The production and commercialization of palm wine from Hyphaene coriacea and Phoenix reclinata in Zitundo area, southern Mozambique
- Authors: Martins, Angelina R O , Shackleton, Charlie M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179802 , vital:43190 , xlink:href="https://doi.org/10.1016/j.sajb.2018.02.389"
- Description: In southern Mozambique a traditional wine is produced using the sap from two palm species, Hyphaene coriacea and Phoenix reclinata. Production of palm wine is one of the main livelihood activities in the Zitundo area. We examined the local production and trade of palm wine in the area. Using structured interviews we investigated the tapping activity, local management practices and the palm wine market, and assessed the incomes derived from palm wine sales and the tappers' perceptions on productivity, abundance and sales fluctuation. Tapping palms was practiced year round in five of the sixteen villages in the area and the mean number of palms tapped per day was 102 ± 52 per tapper. Tappers spent an average of 25 ± 18 h per week on tapping activities resulting in an average return to labour of R39 (± US$3) per hour. The mean, annual, net income from palm wine sales was R24,981 ± R12,094 (US$1878 ± 909) per tapper, which accounted for 85% ± 22% of the tappers' annual household income. Palm wine is a highly commercial commodity in Zitundo area, with an average commercialization index of 63% ± 23%, and is likely to help alleviate poverty in the area. Hyphaene coriacea was tapped more than Phoenix reclinata, although most tappers regard the wine from the latter to be of a better quality. The importance of palm tapping in local livelihoods and poverty alleviation needs greater acknowledgement by government and development agencies in the area, towards inclusion in sectoral development policies and conservation programmes.
- Full Text:
- Date Issued: 2018
Think Piece on Amanzi for Food. Working with Critical Realism to Inform a Situated Learning Framework for Climate Change Education
- Authors: O'Donoghue, Rob B
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/388136 , vital:68309 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/172215"
- Description: This study is developed as a think piece which deliberates the problem of transformative human agency in a curriculum setting. Using a critical realism perspective and schematic tools it examines the deliberative framing of an Amanzi for Food teaching garden as an education process for mediating the learning of rainwater harvesting. Working with Bhaskar’s Transformational Model of Social Activity and using expansions of his ‘four-planar social being’ schema and its resolution in his ‘social cube’ model, the study contemplates the framing for a curriculum for the mediation of co-engaged social learning in the contexts of practical work in an agricultural college curriculum setting. In this way the research process is developed as an under-labouring review of the emerging curriculum in search of theory to inform pedagogy for mediating situated processes of transformative social learning.
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- Date Issued: 2018