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The determination of CHARMM force field parameters for the Mg2+ containing HIV-1 integrase:

- Musyoka, Thommas M, Tastan Bishop, Özlem, Lobb, Kevin A, Moses, Vuyani

  • Authors: Musyoka, Thommas M , Tastan Bishop, Özlem , Lobb, Kevin A , Moses, Vuyani
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/148139 , vital:38713 , DOI: 10.1016/j.cplett.2018.09.019
  • Description: The HIV integrase enzyme is a validated drug target. However, its potential has remained largely unexploited until recently due to lack of structural and mechanistic information. Its catalytic core domain (CCD) is crucial for the viral-human DNA integration making integrase an ideal target for inhibitor design. However, in order to do so, force field parameters for the integrase magnesium ion need to be established. Quantum mechanical calculations were used to derive force field parameters which were validated through molecular dynamics studies. Our results show that the parameters determined accurately maintain the integrity of the metal pocket of the integrase CCD.
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Three new pentacyclic triterpenoids from twigs of Manniophyton fulvum (Euphorbiaceae)

- Mbeunkeu, Ahri B D, Noundou, Xavier S, Krause, Rui W M, Teinkela, Jean E M, Laatsch, Hartmut, Azebaze, Anatole G B, Vardamides, Juliette C, Tala, Michel F

  • Authors: Mbeunkeu, Ahri B D , Noundou, Xavier S , Krause, Rui W M , Teinkela, Jean E M , Laatsch, Hartmut , Azebaze, Anatole G B , Vardamides, Juliette C , Tala, Michel F
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/126782 , vital:35922 , https://doi.org/10.1016/j.phytol.2018.06.019
  • Description: Phytochemical investigation of the methanol extracts of the twigs of Manniophyton fulvum has led to the isolation and characterization of three new pentacyclic triterpenoids, designated as 3α,28-dihydroxyfriedelan-1-one (1), manniotaraxerol A (3) and manniotaraxerol B (4), along with fourteen known compounds, 3α-hydroxy-1-oxofriedelane (2), betulinic acid (5), friedelin (S1), taraxerol (S2), a mixture of stigmasterol (S3) and β-sitosterol (S4), herranone (S5), docosanoic acid (S6), ursolic acid (S7), nasutin B (S8), bergenin (S9), stigmasterol-3-O-β-Dglucopyranoside (S10), 1,2-di-O-palmitoyl-3-O-(6-sulfo-α-D-quinovopyranosyl)glycerol (S11), and aridanin (S12). The structures of all compounds were determined by comprehensive spectroscopic analyses (1D and 2D NMR, EI and ESI-MS). 3α,28-Dihydroxyfriedelan-1-one (1), 3α-hydroxy-1-oxofriedelane (2), manniotaraxerol A (3), manniotaraxerol B (4), and betulinic acid (5) were evaluated against HeLa (human cervix adenocarcinoma) cancer cells. Manniotaraxerol A (3) showed weak in vitro cytotoxicity with a cell viability value of 49.3%. Betulinic acid (5) also showed significant cytotoxicity against HeLa cell with a cell viability value of 4.0%; the other compounds were inactive in this test.
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A contemporary phenomenology of menstruation: Understanding the body in situation and as situation in public health interventions to address menstruation-related challenges

- Kelland, Lindsay, Paphitis, Sharli A, Macleod, Catriona I

  • Authors: Kelland, Lindsay , Paphitis, Sharli A , Macleod, Catriona I
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/434293 , vital:73045 , ISBN 1879-243X , https://doi.org/10.1016/j.wsif.2017.09.004
  • Description: Social science and public health research has pointed to, firstly, the challenges women face in terms of the management of menstruation and, secondly, to the negative symbolic associations made with the menstruating body. This research, however, seldom engages with philosophical issues relating to embodied subjectivity in order to explain and understand the trends noted. In this paper, we attempt to bridge the divide between feminist theory and current research on the menstruation-related challenges facing women today. We provide a feminist phenomenological account of menstruation in which women's shared bodily lived experiences of menstruation—the body as situation—are set within contexts that enable and/or restrain freedom—the body in situation. This account allows us to understand the universal and differentiated aspects of menstruation and menstrual management, thereby providing a nuanced picture of the interplay between the physical occurrence of menstruation, the symbolic associations made with menstruation, and the socio-material, historical and political conditions within which women live. Such an account, we suggest, should inform advocacy around public policy and institutional civic society that promotes the freedom of women to engage in important life projects, and ground public health interventions around menstruation related challenges.
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Anti-malarial synergy of secondary metabolites from Morinda lucida Benth.

- Lakkakula, Jaya R, Matshaya, Thabo, Krause, Rui W M

  • Authors: Lakkakula, Jaya R , Matshaya, Thabo , Krause, Rui W M
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/125609 , vital:35800 , https://doi.org/10.1016/j.msec.2016.08.073
  • Description: Ethnopharmacological relevance The roots, stem and leaves of Morinda lucida are used in some African countries as treatment against different types of fevers including yellow fever, malaria, trypanosomiasis and feverish conditions during child birth. Aim of the study To determine the in vitro cell toxicity and anti-malarial activity of the extracts of stem bark of M. lucida and to identify the secondary metabolites in the extract that may be responsible for this activity. Materials and methods The cell toxicity studies of crude extract [dichloromethane (DCM): Methanol (MeOH) in a ratio of1:1 (v/v)] as well as compounds isolated from the same extract were carried out using human cervix adenocarcinoma cells (HeLa cells); while the anti-malarial activities of the same samples were performed against Plasmodium falciparum strain 3D7 using the parasite lactate dehydrogenase (pLDH) assay. The isolation of the active compounds was carried out using chromatographic techniques (column and thin layer chromatography) where as mass spectrometry (MS), Fourier transform infrared spectroscopy (FTIR) as well as 1D- and 2D- nuclear magnetic resonance (NMR) analyses were employed in the characterisation and identification of the isolated secondary metabolites. Results The pLDH and cell toxicity assays for the crude extract and the fractions of M. lucida indicated that some fractions reduced the malaria parasite viability by approximately 50% at 100 μg/mL and they were not significantly cytotoxic. An IC50 done on the crude extract gave a value of 25 μg/mL. The % cell viability for the crude extract in cell toxicity assay remained at 100%. Seven chemical constituents i.e. asperuloside (1), asperulosidic acid (2), stigmasterol (3a), β-sitosterol (3b), cycloartenol (3c), campesterol (3d) and 5,15-O-dimethylmorindol (4) were isolated from the DCM-MeOH extract of stem bark. The isolated compounds tested were not that active by themselves individually at 20 μM but their activities were increased when the isolated compounds were combined. As seen when compounds 2, 3 and 4 (% viability: 93, 123 and 101 respectively) were combined yielding an IC50 value of 17 μM. Furthermore, this is the first report of compounds 1, 2, 3c, 3d and 4 isolated from M. lucida. Conclusion The crude extract completely suppressed the growth of P. falciparum. This indicates that the crude extract contains many compounds that might be acting in synergy. The observed activity of the crude extract and the samples containing a mixture of different compounds support the traditional use of M. lucida for the treatment of malaria.
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Biology and rearing of Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae) carob moth, a pest of multiple crops in South Africa

- Thackeray, Sean R, Moore, Sean D, Strathie, Lorraine W, Kirkman, Wayne, Hill, Martin P

  • Authors: Thackeray, Sean R , Moore, Sean D , Strathie, Lorraine W , Kirkman, Wayne , Hill, Martin P
  • Date: 2017
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/59799 , vital:27652 , https://doi.org/10.4001/003.025.0474
  • Description: Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae), carob moth, is a pest of several crops in South Africa. A laboratory culture was established from field-collected larvae infesting mummified pecan nuts. Biological parameters of larvae reared on an artificial diet were measured. The insect goes through five larval instars, and the head capsule sizes of the five instars were determined to be <0.34 mm, 0.35-0.64 mm, 0.65-0.94 mm, 0.95-1.14 mm and >0.15 mm for the five instars, respectively. The insect was reared individually and communally in glass vials, the latter to develop a mass-rearing technique. Developmental time from neonate to pupa was significantly slower when larvae were individually reared (38.18 ±1.2 days) compared to when they were communally reared (24.6 ± 0.65 days). A microsporidian infection (Nosema sp.) was recorded in the culture, causing significantly (fy6 = 14.99, P = 0.0082) higher mortality of communally reared larvae (76.25 % ± 11.87) than individually reared larvae (24.9 % ± 9.6).
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Birds as major predators of fishes in the East Kleinemonde Estuary

- Cowley, Paul D, Whitfield, Alan K, Terörde, Anja I

  • Authors: Cowley, Paul D , Whitfield, Alan K , Terörde, Anja I
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/443271 , vital:74104 , https://hdl.handle.net/10520/EJC-c2893c53c
  • Description: This study provides a quantitative account of fish predation by piscivorous birds in the temporarily open/closed East Kleinemonde Estuary and represents the first global attempt to simultaneously relate such consumption to production by a fish community in the same estuary. Cormorants and herons were the dominant predators and seasonal variations in the avifaunal community composition were noted. Based on comprehensive counts over three years, the piscivorous bird population was estimated to have consumed a maximum of 4 414 kg of fish in 1994, 2 400 kg in 1995/96 and 2 960 kg in 2004/05. In 1995/96 fish production in the East Kleinemonde Estuary (55.89 g m−2 a−1) was estimated at 9 780 kg and maximum bird predation amounted to 25% of annual fish production within the system over the same period, assuming that all birds counted on the estuary foraged there and that the diet of these birds comprised only fish. The above 1995/96 figures, together with an estimate of fish predation by the dominant piscivorous fish Lichia amia of 696 kg suggests that birds are probably the single most important natural predator of fishes within this estuary. An unusual mass invasion by marine Cape Cormorants Phalacrocorax capensis during July 1994 was responsible for large-scale predation of fish (2 155 kg) and resulted in the population of estuary-associated marine fishes declining from approximately 63 300 to about 18 600 individuals during the 1994 closed phase. Given that little or no marine fish recruitment was possible while the estuary mouth was closed, piscivorous birds are likely to have a higher predatory impact on populations of juvenile marine fishes in small temporarily closed estuaries than in larger permanently open systems.
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Cationic cyclodextrin/alginate chitosan nanoflowers as 5-fluorouracil drug delivery system

- Lakkakula, Jaya R, Matshaya, Thabo, Krause, Rui W M

  • Authors: Lakkakula, Jaya R , Matshaya, Thabo , Krause, Rui W M
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/125587 , vital:35798 , https://doi.org/10.1016/j.msec.2016.08.073
  • Description: Cyclodextrins (CDs) have widely been used as component of drug delivery systems. However unmodified cyclodextrins are associated with cytotoxicity and poor water solubility thus limiting their use in pharmaceutical industry. The cationic-β-cyclodextrin (Cat-β-CD) polymer cores were synthesized using β-CD, epichlorohydrin and choline chloride via a one-step polycondensation process. The main aim of this study was to synthesize hierarchical nanoflowers composed of cationic-β-CD as polymeric core along with alginate and chitosan “petals” (Cat-β-CD/Alg-Chi nanoflowers) as carriers for oral delivery of 5-Fluorouracil (5-FU) via an ionic-gelation technique. The drug loading capacity, particle size, zeta potential and surface morphology of the synthesized nanoflowers were determined. The prepared nanoflowers were formed with an average size of 300 nm and a zeta potential of + 9.90 mV with good encapsulation efficiency of up to 77.3%. In vitro release of 5-FU from the loaded nanoflowers showed controlled and sustained release compared to the inclusion complex alone. Cat-β-CD/Alg-Chi nanoflowers were assessed against L929 cells and found to be effectively inhibiting the growth of L929 cells in a concentration dependent manner.
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Composition portfolio

- Boesack, Lenrick Jonathan Angus

  • Authors: Boesack, Lenrick Jonathan Angus
  • Date: 2017
  • Subjects: Piano music , Prepared piano music , Saxophone music
  • Language: English
  • Type: text , Thesis , Masters , MMus
  • Identifier: http://hdl.handle.net/10962/56233 , vital:26786
  • Description: This short composition portfolio comprises 40% of the requirements for the Master of Music Degree in performance and composition at Rhodes University. In addition to the music presented here, I played two public exam recitals of 70 minutes each. While I played piano as a child, my main instrument during my BMUS studies at the University of Cape Town (2004-2007) was the saxophone. In 2010 I was diagnosed with Polymyositis(an auto-immune desease) which particularly affected my breathing and therefore my ability to play the saxophone. For this reason I opted to play my recitals on the piano. The first recital focused on interpretations of Swing Era, Bebop and post-Bebop standards such as: Someday my prince will come, What is this thing called love, In your own sweet way, Eternal Triangle, Recordame, Peace, Dolphin Dance, Caravan and Some other blues. The second recital comprised of seven original compositions that were presented in trio, quartet and quintet settings.
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Development of Bioinformatics Infrastructure for Genomics Research:

- Mulder, Nicola J, Adebiyi, Ezekiel, Adebiyi, Marion, Adeyemi, Seun, Ahmed, Azza, Ahmed, Rehab, Akanle, Bola, Alibi, Mohamed, Armstrong, Don L, Aron, Shaun, Ashano, Efejiro, Baichoo, Shakuntala, Benkahla, Alia, Brown, David K, Chimusa, Emile Rugamika, Fadlelmola, Faisal M, Falola, Dare, Fatumo, Segun, Ghedira, Kais, Ghouila, Amel, Hazelhurst, Scott, Itunuoluwa Isewon, Segun Jung, Kassim, Samar Kamal, Kayondo, Jonathan K, Mbiyavanga, Mamana, Meintjes, Ayton, Mohammed, Somia, Mosaku, Abayomi, Moussa, Ahmed, Muhammd, Mustafa, Mungloo-Dilmohamud, Zahra, Nashiru, Oyekanmi, Odia, Trust, Okafor, Adaobi, Oladipo, Olaleye, Osamor, Victor, Oyelade, Jellili, Sadki, Khalid, Salifu, Samson Pandam, Soyemi, Jumoke, Panji, Sumir, Radouani, Fouzia, Souiai, Oussama, Tastan Bishop, Özlem

From Baudelaire to Beardsley: some thoughts on Poe's beast as an indicator of the tastes and fears of nineteenth-century Europe

- Beard, Margot

  • Authors: Beard, Margot
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/147781 , vital:38672 , https://doi.org/10.1080/00043389.2001.11876980
  • Description: Charles Baudelaire (1821 1867) was one of the major influences on the French Decadent poets of the late nineteenth century whose aesthetic principles were shared, to a large extent, by a group of English poets and artists, among whom was Aubrey Beardsley (1872 1898). One of the major influences on Baude laire had been the American, Edgar Allan Poe (1809 1849), in whose short stories and poems Baudelaire had recognised a kindred spirit. Some intriguing aspects of changing nine teenth century attitudes emerge from a study of Baudelaire's 1856 translation of Poe's `The Murders in the Rue Morgue' and Beardsley's 1893 illustration to this story.
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Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective

- Edkins, Adrienne L, Price, John T, Pockley, A Graham, Blatch, Gregory L

  • Authors: Edkins, Adrienne L , Price, John T , Pockley, A Graham , Blatch, Gregory L
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164332 , vital:41109 , DOI: 10.1098/rstb.2016.0521
  • Description: Many heat shock proteins (HSPs) are essential to survival as a consequence of their role as molecular chaperones, and play a critical role in maintaining cellular proteostasis by integrating the fundamental processes of protein folding and degradation. HSPs are arguably among the most prominent classes of proteins that have been broadly linked to many human disorders, with changes in their expression profile and/or intracellular/extracellular location now being described as contributing to the pathogenesis of a number of different diseases. Although the concept was initially controversial, it is now widely accepted that HSPs have additional biological functions over and above their role in proteostasis (so-called ‘protein moonlighting’).
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Improved endoglucanase production and mycelial biomass of some ericoid fungi

- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2017
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
  • Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
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Improved endoglucanase production and mycelial biomass of some ericoid fungi

- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
  • Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
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Improvement of the pharmacological activity of menthol via enzymatic β-anomer-selective glycosylation

- Choi, Ha-Young, Kim, Bo-Min, Morgan, Abubaker M A, Kim, Joong Su, Kim, Won-Gon

  • Authors: Choi, Ha-Young , Kim, Bo-Min , Morgan, Abubaker M A , Kim, Joong Su , Kim, Won-Gon
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/67515 , vital:29106 , http://dx.doi.org/10.1186/s13568-017-0468-0
  • Description: Publisher version , Menthol has a considerable cooling effect, but the use range of menthol is limited because of its extremely low solubility in water and inherent flavor. (−)-Menthol β-glucoside was determined to be more soluble in water (>27 times) than (−)-menthol α-glucoside; hence, β-anomer-selective glucosylation of menthol is necessary. The in vitro glycosylation of (−)-menthol by uridine diphosphate glycosyltransferase (BLC) from Bacillus licheniformis generated (−)-menthol β-glucoside and new (−)-menthol β-galactoside and (−)-menthol N-acetylglucosamine. The maximum conversion rate of menthol to (−)-menthol β-D-glucoside by BLC was found to be 58.9%. Importantly, (−)-menthol β-D-glucoside had a higher cooling effect and no flavor compared with menthol. In addition, (−)-menthol β-D-glucoside was determined to be a non-sensitizer in a skin allergy test in the human cell line activation test, whereas menthol was a sensitizer.
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Improving fold resistance prediction of HIV-1 against protease and reverse transcriptase inhibitors using artificial neural networks:

- Amamuddy, Olivier S, Bishop, Nigel T, Tastan Bishop, Özlem

  • Authors: Amamuddy, Olivier S , Bishop, Nigel T , Tastan Bishop, Özlem
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/148261 , vital:38724 , https://0-doi.org.wam.seals.ac.za/10.1186/s12859-017-1782-x
  • Description: Drug resistance in HIV treatment is still a worldwide problem. Predicting resistance to antiretrovirals (ARVs) before starting any treatment is important. Prediction accuracy is essential, as low-accuracy predictions increase the risk of prescribing sub-optimal drug regimens leading to patients developing resistance sooner. Artificial Neural Networks (ANNs) are a powerful tool that would be able to assist in drug resistance prediction. In this study, we constrained the dataset to subtype B, sacrificing generalizability for a higher predictive performance, and demonstrated that the predictive quality of the ANN regression models have definite improvement for most ARVs.
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Kinetic analysis and general features of thermoluminescence of B2O3-Li2O-ZnF2 glass

- Thomas, Sunil, Chithambo, Makaiko L

  • Authors: Thomas, Sunil , Chithambo, Makaiko L
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/116154 , vital:34324 , https://doi.org/10.1016/j.radmeas.2017.03.038
  • Description: The intention of this study is to explore the thermoluminescence of beta irradiated B2O3-Li2O-ZnF2 glass. The glow-curve corresponding to 200 Gy shows three peaks; two weak-intensity peaks at 60 and 243 °C and a more prominent one at 118 °C, when measured at 1 °C/s. The dose response of the main peak at 118 °C was found to be sublinear in the range 200–1000 Gy. Regarding the kinetic analysis of the main peak, the activation energy of the corresponding electron trap was evaluated as 0.96 eV and the frequency factor as ∼1011 s−1. It is proposed that the thermoluminescence in B2O3-Li2O-ZnF2 glass is due to recombination of electrons, thermally released from Zn+ ionic defect sites, with the holes at boron-oxygen hole centres.
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Oldest known naiaditid bivalve from the high-latitude Late Devonian (Famennian) of South Africa offers clues to survival strategies following the Hangenberg mass extinction

- Scholze, Frank, Gess, Robert W

  • Authors: Scholze, Frank , Gess, Robert W
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/73921 , vital:30241 , https://doi.org/10.1016/j.palaeo.2017.01.018
  • Description: A phased mass extinction event (which culminated in the Hangenberg event) marked the end of the Devonian period and had a significant impact on the palaeoecology and faunal diversity of vertebrate and invertebrate communities. In the present study the taxonomy of bivalves from the Waterloo Farm lagerstätte of the Upper Devonian, Famennian, Witpoort Formation (Witteberg Group, Cape Supergroup) was studied and compared with known Carboniferous examples. For the first time, Devonian bivalves of the Naiaditidae are described from a high-latitude palaeogeographic setting of Gondwana. The presented data suggests a high-latitude origin for post-Hangenberg event Naiaditidae, found at lower latitudes during the Early Carboniferous. This may have resulted from migration to lower latitudes in response to reduced global temperatures, which were associated with climatic perturbation at the time of the Hangenberg event, and which persisted into the Early Carboniferous. Taxa that were adapted to temperature ranges existing at high latitudes during the Late Devonian are likely to have followed these temperature ranges towards lower latitudes with decreasing global temperatures. Here they may have occupied free ecospace available in the aftermath of the Late Devonian extinction event.
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Phylogeny of the Sepia officinalis species complex in the eastern Atlantic extends the known distribution of Sepia vermiculata across the Benguela upwelling region

- Healey, Amy J E, McKeown, Niall J, Potts, Warren M, de Beer, Chénelle L, Sauer, Warwick H H, Shaw, Paul W

  • Authors: Healey, Amy J E , McKeown, Niall J , Potts, Warren M , de Beer, Chénelle L , Sauer, Warwick H H , Shaw, Paul W
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/125631 , vital:35802 , https://doi.10.2989/1814232X.2017.1371076
  • Description: Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks.
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Secondary metabolites from Tetracera potatoria stem bark with anti-mycobacterial activity.

- Fomogne-Fodjo, M C Y, Ndinteh, Derek T, Olivier, Denise K, Krause, Rui W M, Kempgens, Pierre, Van Vuuren, S

  • Authors: Fomogne-Fodjo, M C Y , Ndinteh, Derek T , Olivier, Denise K , Krause, Rui W M , Kempgens, Pierre , Van Vuuren, S
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/125556 , vital:35795 , https://doi.org/10.1016/j.jep.2016.11.027
  • Description: Ethnopharmacological relevance Tetracera potatoria Afzel. Exg. Don (Dilleniaceae) is a medicinal plant used traditionally in Africa for the treatment of tuberculosis related ailments and respiratory infections. The antibacterial activity of the medium polar extracts of T. potatoria leaves and stem bark was recently reported against Mycobacterium smegmatis (MIC 25 µg/mL) and M. aurum (65 µg/mL), two fast-growing Mycobacterium strains used as model micro-organisms for the more pathogenic strain Mycobacterium tuberculosis (Fomogne-Fodjo et al., 2014). The aim of this study was consequently to isolate the compounds possibly contributing to this activity, and which may therefore be promising precursors to be used for the development of novel anti-TB drugs.
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The influence of dose on the kinetic parameters and dosimetric features of the main thermoluminescence glow peak in α-Al2O3: C, Mg

- Kalita, Jitumani M, Chithambo, Makaiko L

  • Authors: Kalita, Jitumani M , Chithambo, Makaiko L
  • Date: 2017
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/119834 , vital:34787 , https://doi.org/10.1016/j.nimb.2016.12.027
  • Description: The influence of dose (0.1–100 Gy) on the kinetic parameters and the dosimetric features of the main glow peak of α-Al2O3:C,Mg have been investigated. Thermoluminescence (TL) measured at 1 °C/s shows a very high intensity glow peak at 161 °C and six secondary peaks at 42, 72, 193, 279, 330, 370 °C respectively. Analysis shows that the main peak follows first order kinetics irrespective of the irradiation dose. The activation energy is found to be consistent at 1.37 eV and the frequency factor is of the order of 1014 s−1 for any dose between 0.1 and 100 Gy. Further, the analysis for thermal quenching of the main peak of 0.1 Gy irradiated sample shows that the activation energy for thermal quenching is (0.94 ± 0.04) eV.
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