Using Facebook user photos to quantify surface water dependency in Southern African arid-zone bird species
- Authors: Dixon, Elizabeth A , Smit, Ben
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441668 , vital:73905 , https://doi.org/10.1080/01584197.2023.2182223
- Description: Birds need to maintain their hydration by either gaining water from their food or by drinking surface water. Many arid-zone birds do not need to consume surface water to maintain body condition. Conservationists need to better understand avian use of surface water sources to inform management plans in a warming world. In this study, we explored the use of Facebook’s image search as a tool to predict interspecific variations in avian surface water use. There was a significant correlation between the proportion of Facebook photographs of each species associated with surface water, and surface water use indices for these species based on published field studies. These findings suggest that Facebook may be a useful source of data for determining the dependence of bird species on surface water. Future research could address the potential for Facebook and other social media platforms for answering a range of ecological questions relating to avian water dependency.
- Full Text:
- Date Issued: 2023
Nature-Based Solutions for Coastal Engineering and Management
- Authors: Slinger, Jill , Stive, Marcel , Luijendijk, Arjen
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177521 , vital:42829 , https://doi.org/10.3390/w13070976
- Description: There is a growing scientific and engineering interest in exploring how natural processes can provide management solutions to resolve the degradation and vulnerability of coastal environments. Climate change and associated sea level rise together with drivers, such as subsidence, reduced sediment supply and coastal squeeze represent major risk factors for coastal systems sustainability. Using natural processes to deal with these risk factors presents a nontrivial challenge. This special issue focuses on nature-based solutions and state-of-the-art interventions in the coastal environment.
- Full Text:
- Date Issued: 2021
Predicting non-target impacts:
- Authors: Paynter, Quentin , Paterson, Iain D , Kwong, Raelene M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149982 , vital:38921 , https://doi.org/10.1016/j.cois.2020.02.002
- Description: Biocontrol of invasive alien weeds has produced great benefits, but concerns over undesirable impacts on non-target plants and/or indirect interactions between biocontrol agents and other biota impede the implementation of biocontrol in some countries. Although great strides have been made, continuing uncertainties predicting the realized host range of candidate agents is probably resulting in some being erroneously rejected due to overestimation of risk. Further refinement of host-range testing protocols is therefore desirable. Indirect interactions are inherently harder to predict, and the risk of both direct and indirect non-target impacts may change over time due to biocontrol agents evolving or expanding their range under climate change. Future research directions to better understand the risk of non-target impacts over time are discussed.
- Full Text:
- Date Issued: 2020
The impact of illustrated side effect information on understanding and sustained retention of antiretroviral side effect knowledge:
- Authors: Scheihing, Konstantin W , Tanner, Jane L , Weaver, Matthew J T , Schöniger, Matthias
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156389 , vital:39985 , https://doi.org/10.1016/j.jup.2020.101043
- Description: About 7.5 million South Africans access gratuitous drinking water via communal taps provided by municipalities under a free basic water policy. Supplying running water for free to low-income communities is essential but can result in water wastage due to a potential indifference of non-paying end-consumers. The consequence is a loss of municipal water and financial resources. We outline a new strategy that rewards low-income communities for reducing water wastage. The incentive strategy promotes water conservation and community development and decreases recurring water-related public expenses. The concept is funded by a percentage of municipal cost savings yielded from the respective water conservation.
- Full Text:
- Date Issued: 2020
The role of the flower-galling mite, Aceria lantanae, in integrated control of the light pink 163LP variety of Lantana camara (L.) in South Africa:
- Authors: Mukwevho, Ludzula , Mphephu, Tshililo E
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149010 , vital:38795 , https://doi.org/10.1016/j.biocontrol.2020.104309
- Description: We evaluated the impact of the gall-forming mite, Aceria lantanae (Cook) (Acari: Trombidiformes: Eriophyidae) on flower and fruit production by coppicing shoots, following pruning, of a widely distributed variety (light pink 163LP) of Lantana camara L. (Verbenaceae) in South Africa. Counts, at three different sites, of developed inflorescences, flowers and fruits and the extent of A. lantanae galling were done for coppicing shoots at four different stages of growth (3, 6, 9- and 12-months post-pruning).
- Full Text:
- Date Issued: 2020
Thermoluminescence properties of potassium fluoride:
- Authors: Ogundare, F O , Folley, Damilola E , Chithambo, Makaiko L , Arise, T O
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160500 , vital:40451 , https://doi.org/10.1016/j.nimb.2020.09.009
- Description: This study is designed to examine the thermoluminescence characteristics of potassium fluoride for possible use as a thermoluminescence dosemeter. Thermoluminescence measurements were carried out at doses up to 20 Gy and heating rates between 0.2 and 4°C/s. The glow curve of the fluoride, readout at 1°Cs−1, exhibited two peaks at 130 and 250 °C. In addition, two shoulder peaks appeared at 70 and 200°C.
- Full Text:
- Date Issued: 2020
UN Decade on Ecosystem Restoration 2021–2030: what chance for success in restoring coastal ecosystems?
- Authors: Waltham, Nathan J , Elliott, Michael , Lee, Shing Yip , Lovelock, Catherine , Duarte, Carlos M , Buelow, Christina , Simenstad, Charles , Nagelkerken, Ivan , Claassens, Louw , Wen, Colin K-C , Barletta, Mario , Connolly, Rod M , Gillies, Chris , Mitsch, William J , Ogburn, Matthew B , Purandare, Jemma , Possingham, Hugh , Sheaves, Marcus
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149836 , vital:38887 , https://doi.org/10.3389/fmars.2020.00071
- Description: On 1 March 2019, the United Nations (UN) General Assembly (New York) declared 2021–2030 the “UN Decade on Ecosystem Restoration.” This call to action has the purpose of recognizing the need to massively accelerate global restoration of degraded ecosystems, to fight the climate heating crisis, enhance food security, provide clean water and protect biodiversity on the planet. The scale of restoration will be key; for example, the Bonn Challenge has the goal to restore 350 million km2 (almost the size of India) of degraded terrestrial ecosystems by 2030. However, international support for restoration of “blue” coastal ecosystems, which provide an impressive array of benefits to people, has lagged. Only the Global Mangrove Alliance (https://mangrovealliance.org/) comes close to the Bonn Challenge, with the aim of increasing the global area of mangroves by 20% by 2030. However, mangrove scientists have reservations about this target, voicing concerns that it is unrealistic and may prompt inappropriate practices in attempting to reach this target (Lee et al., 2019). The decade of ecosystem restoration declaration also coincides with the UN Decade of Ocean Science for Sustainable Development, which aims to reverse deterioration in ocean health. If executed in a holistic and coordinated manner, signatory nations could stand to deliver on both these UN calls to action.
- Full Text:
- Date Issued: 2020
A novel technique for artificial pack formation in African wild dogs using odour familiarity:
- Authors: Marneweck, Courtney J , Marchal, Antoine F J , Marneweck, David G , Beverley, Grant , Davies-Mostert, Harriet T , Parker, Daniel M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150060 , vital:38935 , https://doi.org/10.3957/056.049.0116
- Description: Reintroductions are recognized tools for species recovery. However, operations are costly, difficult to implement, and failures are common and not always understood. Their success for group-living species depends on the mimicry of natural processes that promote social integration. Due to fragmented landscapes, human mediated (i.e. artificial) group formation is often required.
- Full Text:
- Date Issued: 2019
An Evaluation of Text Mining Techniques in Sampling of Network Ports from IBR Traffic
- Authors: Chindipha, Stones D , Irwin, Barry V W , Herbert, Alan
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427630 , vital:72452 , https://www.researchgate.net/profile/Stones-Chindi-pha/publication/335910179_An_Evaluation_of_Text_Mining_Techniques_in_Sampling_of_Network_Ports_from_IBR_Traffic/links/5d833084458515cbd1985a38/An-Evaluation-of-Text-Mining-Techniques-in-Sampling-of-Network-Ports-from-IBR-Traffic.pdf
- Description: Information retrieval (IR) has had techniques that have been used to gauge the extent to which certain keywords can be retrieved from a document. These techniques have been used to measure similarities in duplicated images, native language identification, optimize algorithms, among others. With this notion, this study proposes the use of four of the Information Retrieval Techniques (IRT/IR) to gauge the implications of sampling a/24 IPv4 ports into smaller subnet equivalents. Using IR, this paper shows how the ports found in a/24 IPv4 net-block relate to those found in the smaller subnet equivalents. Using Internet Background Radiation (IBR) data that was collected from Rhodes University, the study found compelling evidence of the viability of using such techniques in sampling datasets. Essentially, being able to identify the variation that comes with sampling the baseline dataset. It shows how the various samples are similar to the baseline dataset. The correlation observed in the scores proves how viable these techniques are to quantifying variations in the sampling of IBR data. In this way, one can identify which subnet equivalent best represents the unique ports found in the baseline dataset (IPv4 net-block dataset).
- Full Text:
- Date Issued: 2019
David Kolaone fought for the right to define himself and his art:
- Authors: Simbao, Ruth K
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146981 , vital:38582 , https://theconversation.com/david-koloane-fought-for-the-right-to-define-himself-and-his-art-120687
- Description: Dr David Nthubu Koloane, who was born in South Africa in 1938, was an extraordinary pioneer in the visual arts who fiercely defied any form of categorisation. As an artist, teacher, mentor, curator, arts administrator and author, he fought for the human right to define oneself and to determine one’s own future.
- Full Text:
- Date Issued: 2019
Mulling over Art with Andrew Mulenga: Artnet “Intelligence Report” magnifies African Art Market
- Authors: Mulenga, Andrew
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146826 , vital:38561 , https://www.themastonline.com/2019/09/24/mulling-over-art-artnet-intelligence-report-magnifies-african-art-market/
- Description: In its latest “Intelligence Report” released on 10th September titled Welcome to the Age of the Art Industry (The Art World Is Over) which coincides with its 30th anniversary, artnet News advances a thesis: that over the past 30 years, the art world has evolved into an art industry.
- Full Text:
- Date Issued: 2019
Mulling over Art with Andrew Mulenga: Lechwe celebrates 2 Zambian art icons
- Authors: Mulenga, Andrew
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146868 , vital:38565 , https://www.themastonline.com/2019/10/29/mulling-over-art-lechwe-celebrates-2-zambian-art-icons/
- Description: LESS than a year after its official opening, the Lechwe Trust Art Gallery on Lagos Road in Lusaka is the venue for Art Lives On – ii, an exhibition of artworks by Lutanda S. Mwamba (1966-2014) and Flinto S. Chandia (1955-2017) which opens next week on Thursday 7th November and runs until the end of February.
- Full Text:
- Date Issued: 2019
The impact of illustrated side effect information on understanding and sustained retention of antiretroviral side effect knowledge:
- Authors: Browne, Sara H , Barford, Kirsty-Lee , Ramela, Thato , Dowse, Roslind
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156341 , vital:39980 , https://doi.org/10.1016/j.sapharm.2018.05.012
- Description: Prompt management of side effects is critical to supporting adherence to antiretroviral (ARV) medication. This study examines the impact of presenting side effect information using simple text combined with pictograms on sustained knowledge of ARV side effects over three months. Previously designed side effect pictograms, combined with simple text, were incorporated into a side effects panel within an ARV information leaflet. In a randomised controlled study, 116 limited literacy HIV patients taking ARVs were randomly allocated to either control (standard care) or intervention groups (standard care plus illustrated information). Side effect knowledge was assessed at baseline, and intervention patients received the illustrated leaflet. Knowledge was re-tested at one and three months. Interpretation of side effect pictograms was evaluated at one month.
- Full Text:
- Date Issued: 2019
The speculative collectivity of the global transnational, or, social practice and the international division of labour:
- Authors: Tello, Verónica
- Date: 2019
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/146378 , vital:38520 , ISBN 9781351399111
- Description: Book abstract. The Routledge Companion to Theatre and Politics is a volume of critical essays, provocations, and interventions on the most important questions faced by today’s writers, critics, audiences, and theatre and performance makers. Featuring texts written by scholars and artists who are diversely situated (geographically, culturally, politically, and institutionally), its multiple perspectives broadly address the question "How can we be political now?".
- Full Text:
- Date Issued: 2019
Capturing the Soweto Uprising: South Africa’s most iconic photograph lives on
- Authors: Simbao, Ruth K
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147036 , vital:38587 , https://theconversation.com/capturing-the-soweto-uprising-south-africas-most-iconic-photograph-lives-on-98318
- Description: Sam Nzima, the photographer who captured the iconic image of the 1976 Soweto Uprising passed awayon May 12, 2018. The photograph was one of six frames showing Mbuyisa Makhubu carrying 12-year-old Hector Pieterson who was shot by police, and Hector’s sister, Antionette Pieterson (now Sithole) running alongside.
- Full Text:
- Date Issued: 2018
Isolation and Characterisation of Stigmasterol and β–Sitosterol from Anthocleista djalonensis A. Chev.
- Authors: Okoro, Ijeoma S , Tor-Anyiin, Terrumun A , Igoli, John O , Noundou, Xavier S , Krause, Rui W M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126191 , vital:35857 , https://doi.org/10.9734/AJOCS/2017/37147
- Description: Aim: Anthocleista djalonensis A. Chev. is a plant with several chemical constituents whichaccounts for its ethno-pharmacological uses. The present study is aimed at identifying and characterizing the active principles from the roots of the plant. Place and Duration of Study: The study was carried out at the Department of Organic Chemistry,Rhodes University, Grahamstown, South Africa between March and July 2016. Methodology: The root powder was subjected to maceration with methanol to obtain the crude extract. The methanol extract was fractionated using hexane, ethyl acetate and acetone successively. The acetone extract was thereafter subjected to column chromatography to isolate any pure components. Results: White needle-like crystals were obtained which on spectral analysis(IR, 1H NMR, 13C NMR, 2D- NMR, and ESI-MS ) were identified as a mixture of stigmasterol and β-sitosterol. Conclusion: The compounds isolated were identified as stigmasterol and β-sitosterol.
- Full Text:
- Date Issued: 2018
NMR structural elucidation of channaine, an unusual alkaloid from Sceletium tortuosum:
- Authors: Veale, Clinton G L , Chen, Weiyang , Chaudhary, Sushil , Kituyi, Sarah N , Isaacs, Michelle , Hoppe, Heinrich C , Edkins, Adrienne L , Combrinck, Sandra , Mehari, Bewketu , Viljoen, Alvaro
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164345 , vital:41110 , DOI: 10.1016/j.phytol.2017.11.018
- Description: Chemical interrogation of the Sceletium genus and Amaryllidaceae family of plants has yielded a diverse array of aryl-hydroindole containing alkaloids. Included in this class is channaine, which was tentatively identified, without comprehensive structural elucidation from Sceletium tortuosum in 1957. Following its isolation from S. strictum, the structure of channaine was eventually resolved by X-ray crystallographic analysis, which revealed an unusual cage-like ring structure at the interface of two aryl-hydroindole subunits. However, since this report in 1978, channaine has not re-appeared in the literature. In this letter, the full NMR characterisation of channaine, isolated from S. tortuosum collected from St Helena in the Western Cape Province of South Africa, is reported for the first time.
- Full Text:
- Date Issued: 2018
Optically stimulated luminescence of ultra-high molecular weight polyethylene: a study of dosimetric features
- Authors: Chithambo, Makaiko L , Kalita, Jitumani M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/110035 , vital:33217 , https://doi.org/10.1016/j.radmeas.2018.06.006
- Description: We report the dosimetric features of ultra-high molecular weight polyethylene (UHMWPE) using luminescence optically stimulated using 470 nm blue light. Samples irradiated to between 1 and 1000 Gy produces luminescence that increases with irradiation dose to produce a linear dose response between 1 and 1000 Gy. The sample was determined not to be affected by pre-dose in tests using a pre-dose of 4000 Gy. This characteristic precludes the need for elaborate background erasing routines typical of dosimetry experiments. The signal has good reproducibility. We used this property to test recovery of ‘unknown’ doses with encouraging results. It was observed that luminescence can also be stimulated using 870 nm infrared light. The dose response, fading, pre-dose effect and the ability to optically stimulate luminescence from the polymer is discussed in terms of curing involving free-radicals.
- Full Text: false
- Date Issued: 2018
pH-Dependent release of isoniazid from isonicotinic acid (4-hydroxy-benzylidene)-hydrazide loaded liposomes
- Authors: Nkanga, Christian I , Tor-Anyiin, Terrumun A , Igoli, John O , Noundou, Xavier S , Krause, Rui W M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126427 , vital:35884 , https://doi.org/10.9734/AJOCS/2017/37147
- Description: Liposomes are considered as potential vehicles for the delivery of anti-tuberculosis drugs (ATBD) due to their rapid uptake by alveolar macrophages, where the mycobacterium often resides. This may provide macrophage-targeting effects that would be key to site specific ATBD delivery using pH-sensitive liposomes, considering the pH-gradient found in the phagocytotic pathway. In this study, isoniazid (INH) was conjugated to 4-hydroxy-benzaldehyde via a hydrazone bond to yield isonicotinic acid (4-hydroxy-benzylidene)-hydrazide (INH-HB). This conjugate was encapsulated in crude soybean lecithin liposomes using film hydration method. INH-HB loaded liposomes (IHL) were characterized by means of dynamic light scattering, transmission electron microscopy, differential scanning calorimetry and X-ray diffraction. The release of INH from IHL was evaluated in media of different pH using a dialysis method. The particle size, Zeta Potential and encapsulation efficiency of IHL were about 945 nm, −62 mV and 89% respectively. In media of pH 7.4, 6.4, 5.4 and 4.4; the IHL exhibited respectively 22, 69, 83 and 100% of release over 12 h. In addition to possible targeted delivery, this pH-dependent release behavior may be suitable for minimizing the loss of INH by leakage from liposomes. The characteristics of IHL are promising for potential site-specific delivery of ATBD.
- Full Text:
- Date Issued: 2018
Thermoluminescence of the persistent-luminescence phosphor, BaAl2O4: a stuffed tridymite
- Authors: Pandey, A , Chithambo, Makaiko L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/113048 , vital:33693 , hhttps://doi.org/10.1016/j.radmeas.2018.01.004
- Description: BaAl2O4 is a stuffed tridymite used as a long-lasting phosphor. The thermoluminescence of BaAl2O4 prepared by solution-combustion is reported. Analysis of the sample using X-ray diffraction shows that it formed as a single phase compound with a hexagonal structure following annealing at 1200 °C. A broad photoluminescence emission band between 300 and 650 nm was detected due to excitation at 248 nm. The phosphor showed a natural TL peak at 102 °C for measurement at 1 oCs−1 and, when beta irradiated to 100 Gy, two broad peaks at 123 and 318 °C also for heating at 1 oCs−1. The analysis of the main glow peak at 123 °C suggests that it is a combination of several collocated peaks, that is, peaks embedded within each other. We resolved four such components labelled peaks 1 to 4. The thermoluminescence decreases with heating rate in a way consistent with thermal quenching whose activation energy was determined as ∼0.65eV using peak 3. Interestingly, this value of the activation energy for thermal quenching for BaAl2O4, a stuffed derivative of silica, is similar to literature values for quartz (a silica), suggesting that the recombination centre in the two cases may be similar.
- Full Text: false
- Date Issued: 2018