Phylogeny of the family Trogidae (Coleoptera: Scarabaeoidea) inferred from mitochondrial and nuclear ribosomal DNA sequence data
- Strümpher, Werner P, Sole, Catherine L, Villet, Martin H, Scholtz, Clarke H
- Authors: Strümpher, Werner P , Sole, Catherine L , Villet, Martin H , Scholtz, Clarke H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442253 , vital:73970 , https://doi.org/10.1111/syen.12074
- Description: Trogidae constitute a monophyletic and biologically unique family within Scarabaeoidea, being the only keratinophagous group in the superfamily. Traditionally, the family has been divided into three distinctive genera, Polynoncus Burmeister, Omorgus Erichson and Trox Fabricius. Although the taxonomy of the group is relatively well studied, changes to the existing classification have recently been proposed and the family as currently constituted has not been subjected to phylogenetic analyses. Here we present a molecular phylogeny for this cosmopolitan family based on three partially sequenced gene regions: 16S rRNA, 18S rRNA and 28S rRNA (domain 2). Included in the analyses are representatives belonging to four of the five extant genera (and three of the four subgenera) from all major zoogeographic regions, representing about 20% of the known trogid species diversity in the family. Phylogenetic analyses performed included parsimony and Bayesian inference. We deduce their historical biogeography by using trogid fossils as calibration points for divergence estimates. Our analyses resolved relationships between and within genera and subgenera that are largely congruent with existing phylogeny hypotheses based on morphological data. We recovered four well‐supported radiations: Polynoncus, Omorgus, Holarctic Trox and African Phoberus MacLeay. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. The subgenera Trox and Phoberus should be elevated to genera to include the Holarctic and all the Afrotropical species, respectively, and Afromorgus returned to subgeneric rank. Estimates of divergence time are consistent with a Pangaean origin of the family in the Early Jurassic. The subsequent diversification of the major lineages is largely attributed to the break‐up of Pangaea and Gondwana in the Middle Jurassic and early Late Cretaceous, respectively.
- Full Text:
- Date Issued: 2014
- Authors: Strümpher, Werner P , Sole, Catherine L , Villet, Martin H , Scholtz, Clarke H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442253 , vital:73970 , https://doi.org/10.1111/syen.12074
- Description: Trogidae constitute a monophyletic and biologically unique family within Scarabaeoidea, being the only keratinophagous group in the superfamily. Traditionally, the family has been divided into three distinctive genera, Polynoncus Burmeister, Omorgus Erichson and Trox Fabricius. Although the taxonomy of the group is relatively well studied, changes to the existing classification have recently been proposed and the family as currently constituted has not been subjected to phylogenetic analyses. Here we present a molecular phylogeny for this cosmopolitan family based on three partially sequenced gene regions: 16S rRNA, 18S rRNA and 28S rRNA (domain 2). Included in the analyses are representatives belonging to four of the five extant genera (and three of the four subgenera) from all major zoogeographic regions, representing about 20% of the known trogid species diversity in the family. Phylogenetic analyses performed included parsimony and Bayesian inference. We deduce their historical biogeography by using trogid fossils as calibration points for divergence estimates. Our analyses resolved relationships between and within genera and subgenera that are largely congruent with existing phylogeny hypotheses based on morphological data. We recovered four well‐supported radiations: Polynoncus, Omorgus, Holarctic Trox and African Phoberus MacLeay. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. The subgenera Trox and Phoberus should be elevated to genera to include the Holarctic and all the Afrotropical species, respectively, and Afromorgus returned to subgeneric rank. Estimates of divergence time are consistent with a Pangaean origin of the family in the Early Jurassic. The subsequent diversification of the major lineages is largely attributed to the break‐up of Pangaea and Gondwana in the Middle Jurassic and early Late Cretaceous, respectively.
- Full Text:
- Date Issued: 2014
Phytoplankton community diversity along a river-estuary continuum
- Dalu, Tatenda, Froneman, P William, Richoux, Nicole B
- Authors: Dalu, Tatenda , Froneman, P William , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457284 , vital:75622 , xlink:href="https://hdl.handle.net/10520/EJC156752"
- Description: In this paper we examine the aspects of phytoplankton communities along a riverine-estuarine continuum in the Kowie system, Eastern Cape (South Africa). This study aims to relate the phytoplankton population community structure to physicochemical parameters and estimate the different chlorophyll-a concentrations for the Kowie system. Eight sampling sites along a 70 km reach of the Kowie system were sampled over a one-year period. One hundred and seventy-eight species belonging to 78 genera were recorded within the riverine-estuarine continuum. Diatoms were predominant, accounting for 81.9% of the total abundance. The estuary had 98 species (55 genera) recorded whereas the river had 141 species (67 genera). Using a two-way analysis of variance (ANOVA), species richness was found to differ significantly amongst seasons. The chl-a concentration along the estuarine-riverine continuum increased from spring to a high in summer (river mean = 7.9 mg m -3 and estuary mean = 3.3 mg m -3 ) before decreasing to a low in winter. Kruskal Wallis ANOVA showed significant differences among chl-a concentration with seasons and sites. Redundancy analysis identified five factors salinity, water depth, aerial cover, nitrates and ammonia that were significant (p is less than 0.05) in affecting phytoplankton variation. The relatively small study indicates the need for further monitoring to gain a better understanding of Kowie system phytoplankton.
- Full Text:
- Date Issued: 2014
- Authors: Dalu, Tatenda , Froneman, P William , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457284 , vital:75622 , xlink:href="https://hdl.handle.net/10520/EJC156752"
- Description: In this paper we examine the aspects of phytoplankton communities along a riverine-estuarine continuum in the Kowie system, Eastern Cape (South Africa). This study aims to relate the phytoplankton population community structure to physicochemical parameters and estimate the different chlorophyll-a concentrations for the Kowie system. Eight sampling sites along a 70 km reach of the Kowie system were sampled over a one-year period. One hundred and seventy-eight species belonging to 78 genera were recorded within the riverine-estuarine continuum. Diatoms were predominant, accounting for 81.9% of the total abundance. The estuary had 98 species (55 genera) recorded whereas the river had 141 species (67 genera). Using a two-way analysis of variance (ANOVA), species richness was found to differ significantly amongst seasons. The chl-a concentration along the estuarine-riverine continuum increased from spring to a high in summer (river mean = 7.9 mg m -3 and estuary mean = 3.3 mg m -3 ) before decreasing to a low in winter. Kruskal Wallis ANOVA showed significant differences among chl-a concentration with seasons and sites. Redundancy analysis identified five factors salinity, water depth, aerial cover, nitrates and ammonia that were significant (p is less than 0.05) in affecting phytoplankton variation. The relatively small study indicates the need for further monitoring to gain a better understanding of Kowie system phytoplankton.
- Full Text:
- Date Issued: 2014
Polyamide nanofiber membranes functionalized with zinc phthalocyanines
- Goethals, Annelies, Mugadza, Tawanda, Arslanoglu, Yasin, Zugle, Ruphino, Antunes, Edith M, Van Hulle, Stijn W, Nyokong, Tebello, De Clerck, Karen
- Authors: Goethals, Annelies , Mugadza, Tawanda , Arslanoglu, Yasin , Zugle, Ruphino , Antunes, Edith M , Van Hulle, Stijn W , Nyokong, Tebello , De Clerck, Karen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241505 , vital:50945 , xlink:href="https://doi.org/10.1002/app.40486"
- Description: Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post-functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2-diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol−1Zn min−1. During short term leaching tests, phthalocyanines could not be detected.
- Full Text:
- Date Issued: 2014
- Authors: Goethals, Annelies , Mugadza, Tawanda , Arslanoglu, Yasin , Zugle, Ruphino , Antunes, Edith M , Van Hulle, Stijn W , Nyokong, Tebello , De Clerck, Karen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241505 , vital:50945 , xlink:href="https://doi.org/10.1002/app.40486"
- Description: Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post-functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2-diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol−1Zn min−1. During short term leaching tests, phthalocyanines could not be detected.
- Full Text:
- Date Issued: 2014
Positioning non-timber forest products on the development agenda
- Shackleton, Charlie M, Pandey, Ashok K
- Authors: Shackleton, Charlie M , Pandey, Ashok K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180992 , vital:43679 , xlink:href="https://doi.org/10.1016/j.forpol.2013.07.004"
- Description: Non-timber forests products (NTFPs) provide multiple livelihood benefits to local communities and regional and national economies. And yet this knowledge is rarely drawn upon in debates around and design of poverty alleviation or land use policies, strategies and projects. Unless the accumulating wealth of empirical evidence can be translated into policies and approaches at higher levels, and integrated into poverty alleviation programmes, it will have little impact on local and national poverty profiles. In this paper we propose and briefly discuss eight steps to facilitate integration of NTFPs into the development agenda, for the benefit of local communities. These include: (1) proper inventory of NTFP stocks, (2) research on NTFP ecology and sustainable harvest levels, (3) introduction of extension services for NTFPs, (4) inclusion of NTFPs in land management and trade-off decisions, (5) integration of NTFPs into sectoral policies, (6) ensuring NTFP commercialisation is not at the expense of local livelihood needs, (7) promoting security of access and use, and (8) examination of local contextual drivers of unsustainable use. Each is presented along with examples or proposals towards implementation.
- Full Text:
- Date Issued: 2014
- Authors: Shackleton, Charlie M , Pandey, Ashok K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180992 , vital:43679 , xlink:href="https://doi.org/10.1016/j.forpol.2013.07.004"
- Description: Non-timber forests products (NTFPs) provide multiple livelihood benefits to local communities and regional and national economies. And yet this knowledge is rarely drawn upon in debates around and design of poverty alleviation or land use policies, strategies and projects. Unless the accumulating wealth of empirical evidence can be translated into policies and approaches at higher levels, and integrated into poverty alleviation programmes, it will have little impact on local and national poverty profiles. In this paper we propose and briefly discuss eight steps to facilitate integration of NTFPs into the development agenda, for the benefit of local communities. These include: (1) proper inventory of NTFP stocks, (2) research on NTFP ecology and sustainable harvest levels, (3) introduction of extension services for NTFPs, (4) inclusion of NTFPs in land management and trade-off decisions, (5) integration of NTFPs into sectoral policies, (6) ensuring NTFP commercialisation is not at the expense of local livelihood needs, (7) promoting security of access and use, and (8) examination of local contextual drivers of unsustainable use. Each is presented along with examples or proposals towards implementation.
- Full Text:
- Date Issued: 2014
Predicting the geographic distribution of Lucilia sericata and Lucilia cuprina (Diptera Calliphoridae) in South Africa
- Williams, Kirstin A, Richards, Cameron S, Villet, Martin H
- Authors: Williams, Kirstin A , Richards, Cameron S , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440681 , vital:73803 , https://hdl.handle.net/10520/EJC158017
- Description: Lucilia sericata (Meigen, 1826) and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae: Luciliinae) have medical, veterinary and forensic importance. Knowing their distribution in South Africa would allow more effective management and utilisation of these flies. Their predicted geographic distributions in South Africa were modelled using maximum entropy analysis of selected climatic variables. The most important environmental variables in modelling the distributions were the magnitude of monthly rainfall and the magnitude of the monthly maximum temperature for L. sericata and the seasonal variation in monthly mean humidity and magnitude of monthly rainfall for L. cuprina. A clear geographical bias was shown in museum records and supports the need for focused surveys. There was no correlation between the predicted distribution of L. cuprina and sheep farming in South Africa, nor between the predicted distribution of L. sericata and human population density. Although their patterns of occurrence differed, both species are widely distributed in South Africa and therefore one cannot identify these flies by locality alone - morphological or molecular identification is necessary.
- Full Text:
- Date Issued: 2014
- Authors: Williams, Kirstin A , Richards, Cameron S , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440681 , vital:73803 , https://hdl.handle.net/10520/EJC158017
- Description: Lucilia sericata (Meigen, 1826) and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae: Luciliinae) have medical, veterinary and forensic importance. Knowing their distribution in South Africa would allow more effective management and utilisation of these flies. Their predicted geographic distributions in South Africa were modelled using maximum entropy analysis of selected climatic variables. The most important environmental variables in modelling the distributions were the magnitude of monthly rainfall and the magnitude of the monthly maximum temperature for L. sericata and the seasonal variation in monthly mean humidity and magnitude of monthly rainfall for L. cuprina. A clear geographical bias was shown in museum records and supports the need for focused surveys. There was no correlation between the predicted distribution of L. cuprina and sheep farming in South Africa, nor between the predicted distribution of L. sericata and human population density. Although their patterns of occurrence differed, both species are widely distributed in South Africa and therefore one cannot identify these flies by locality alone - morphological or molecular identification is necessary.
- Full Text:
- Date Issued: 2014
Pregnancy among young women in South Africa
- Macleod, Catriona I, Tracey, Tiffany
- Authors: Macleod, Catriona I , Tracey, Tiffany
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434371 , vital:73052 , ISBN 978-1-4899-8025-0 , https://doi.org/10.1007/978-1-4899-8026-7
- Description: In 1994, South Africa witnessed its first democratic elections after centuries of colonial and then apartheid rule. As time passes since that euphoric moment in 1994, the difficulties of transformation have become evident. In terms of sexual and reproductive health, HIV/AIDS is acknowledged as one of the most significant challenges, with South Africa having one of the highest infection rates globally. Pregnancy among teenage women is receiving increasing attention as well. For example, public concern has been expressed that the recently introduced Child Support Grant (CSG) acts as a ‘perverse incentive’ for young women to bear children. This emotional claim was refuted by separately commissioned reviews of research on girls who received the grant. National statistics paint an interesting picture that negates the popular opinion in South Africa that rates of teenage pregnancy and childbearing are escalating. The 1998, the South African Demographic and Health Survey (SADHS) indicated that 35 % of women had had a child by the age of 19 years, while in the 2003 SADHS survey, this had decreased to 27 %. The rights-based approach adopted by the South African government to sexual and reproductive health enshrines a young woman’s right to prevent an unwanted pregnancy, to plan a pregnancy with her partner should they wish, to make an independent decision concerning the outcome of a pregnancy, to terminate that pregnancy safely should she wish, and to access non-discriminatory prenatal and postnatal care should she take the pregnancy to term. While there are still many obstacles and challenges associated with the issues of ‘adolescent pregnancy,’ it is important to remember the success represented by, and that arises from, this rights-based legislation.
- Full Text:
- Date Issued: 2014
- Authors: Macleod, Catriona I , Tracey, Tiffany
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434371 , vital:73052 , ISBN 978-1-4899-8025-0 , https://doi.org/10.1007/978-1-4899-8026-7
- Description: In 1994, South Africa witnessed its first democratic elections after centuries of colonial and then apartheid rule. As time passes since that euphoric moment in 1994, the difficulties of transformation have become evident. In terms of sexual and reproductive health, HIV/AIDS is acknowledged as one of the most significant challenges, with South Africa having one of the highest infection rates globally. Pregnancy among teenage women is receiving increasing attention as well. For example, public concern has been expressed that the recently introduced Child Support Grant (CSG) acts as a ‘perverse incentive’ for young women to bear children. This emotional claim was refuted by separately commissioned reviews of research on girls who received the grant. National statistics paint an interesting picture that negates the popular opinion in South Africa that rates of teenage pregnancy and childbearing are escalating. The 1998, the South African Demographic and Health Survey (SADHS) indicated that 35 % of women had had a child by the age of 19 years, while in the 2003 SADHS survey, this had decreased to 27 %. The rights-based approach adopted by the South African government to sexual and reproductive health enshrines a young woman’s right to prevent an unwanted pregnancy, to plan a pregnancy with her partner should they wish, to make an independent decision concerning the outcome of a pregnancy, to terminate that pregnancy safely should she wish, and to access non-discriminatory prenatal and postnatal care should she take the pregnancy to term. While there are still many obstacles and challenges associated with the issues of ‘adolescent pregnancy,’ it is important to remember the success represented by, and that arises from, this rights-based legislation.
- Full Text:
- Date Issued: 2014
Primary wing-moult and site fidelity in South African mousebirds (Coliidae)
- Craig, Adrian J F K, Bonnevie, Bo T, Hulley, Patrick E, Underhill, George D
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hulley, Patrick E , Underhill, George D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449474 , vital:74824 , https://doi.org/10.2989/00306525.2014.931310
- Description: Based on large samples of birds mist-netted in the Eastern Cape and the Western Cape, moult of the primary remiges in both Speckled Mousebirds Colius striatus and Red-faced Mousebirds Urocolius indicus occurred throughout the year with no regional or seasonal patterns evident. The same picture emerged for the White-backed Mousebird Colius colius in the Western Cape. This aseasonality of wing-moult for all three species in South Africa was further supported by the full data set of moult records available in the Safring database. We were thus unable to use the Underhill–Zucchini model to estimate the moult parameters for these species, but an extended moult period seems likely. Recapture data for the Eastern Cape strongly suggest that Speckled Mousebirds are resident or revisit sites frequently, whereas this is not the case for Red-faced Mousebirds.
- Full Text:
- Date Issued: 2014
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hulley, Patrick E , Underhill, George D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449474 , vital:74824 , https://doi.org/10.2989/00306525.2014.931310
- Description: Based on large samples of birds mist-netted in the Eastern Cape and the Western Cape, moult of the primary remiges in both Speckled Mousebirds Colius striatus and Red-faced Mousebirds Urocolius indicus occurred throughout the year with no regional or seasonal patterns evident. The same picture emerged for the White-backed Mousebird Colius colius in the Western Cape. This aseasonality of wing-moult for all three species in South Africa was further supported by the full data set of moult records available in the Safring database. We were thus unable to use the Underhill–Zucchini model to estimate the moult parameters for these species, but an extended moult period seems likely. Recapture data for the Eastern Cape strongly suggest that Speckled Mousebirds are resident or revisit sites frequently, whereas this is not the case for Red-faced Mousebirds.
- Full Text:
- Date Issued: 2014
Rape and the Foundation of Nations in JM Coetzee's Disgrace
- Authors: Van Wyk Smith, Malvern
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458298 , vital:75730 , https://hdl.handle.net/10520/EJC156478
- Description: When J. M. Coetzee's last South African novel, Disgrace, was published in 1999 (he emigrated to Australia two years later), it drew some very sharp responses. Max du Preez wrote in the Star (21 Jan. 2000): "[The] message of Disgrace, crudely put, is that black South Africans are revengeful of whites; that whites are not welcome in Africa unless they pay for it every day; that black and white attitudes and lifestyles are incompatible" (cited in Kannemeyer 528). Athol Fugard was notoriously quoted in the London Sunday Times as believing that the novel was about "the rape of a white woman as a gesture to all of the evil we did in the past," an idea that he dismissed as "a load of bullshit" (cited in Attridge 164). One could go on, but what quickly became evident in the critical feeding frenzy that soon followed was that Coetzee's utilization of a stark realism - a new mode for him, tried out in his major fiction only once before, in parts of Age of Iron (1990) - as well as his invocation of a trope as sensationally shocking and topical as farm rape, and his evident concern with racial retribution, had made it very difficult for most readers to see beyond the features of politics and plot in the novel.
- Full Text:
- Date Issued: 2014
- Authors: Van Wyk Smith, Malvern
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458298 , vital:75730 , https://hdl.handle.net/10520/EJC156478
- Description: When J. M. Coetzee's last South African novel, Disgrace, was published in 1999 (he emigrated to Australia two years later), it drew some very sharp responses. Max du Preez wrote in the Star (21 Jan. 2000): "[The] message of Disgrace, crudely put, is that black South Africans are revengeful of whites; that whites are not welcome in Africa unless they pay for it every day; that black and white attitudes and lifestyles are incompatible" (cited in Kannemeyer 528). Athol Fugard was notoriously quoted in the London Sunday Times as believing that the novel was about "the rape of a white woman as a gesture to all of the evil we did in the past," an idea that he dismissed as "a load of bullshit" (cited in Attridge 164). One could go on, but what quickly became evident in the critical feeding frenzy that soon followed was that Coetzee's utilization of a stark realism - a new mode for him, tried out in his major fiction only once before, in parts of Age of Iron (1990) - as well as his invocation of a trope as sensationally shocking and topical as farm rape, and his evident concern with racial retribution, had made it very difficult for most readers to see beyond the features of politics and plot in the novel.
- Full Text:
- Date Issued: 2014
Real-time monitoring of 3T3-L1 preadipocyte differentiation using a commercially available electric cell-substrate impedance sensor system
- Kramer, Adam H, Joos-Vandewalle, Julia, Edkins, Adrienne L, Frost, Carminita L, Prinsloo, Earl
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431171 , vital:72751 , xlink:href="https://doi.org/10.1016/j.bbrc.2013.12.123"
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431171 , vital:72751 , xlink:href="https://doi.org/10.1016/j.bbrc.2013.12.123"
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
Relationship between soil alteration index three (AI3), soil organic matter and tree performance in a 'Cripps Pink/'M7 apple orchard
- Meyer, André H, Wooldridge, John, Dames, Joanna F
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444038 , vital:74180 , https://hdl.handle.net/10520/EJC157392
- Description: Alteration index three (AI3), which calculates the balances between three microbially-secreted enzymes, potentially enables differences between soils due to contrasting management practices to be quantified in relative terms. The ability of AI3 to distinguish between apple orchard soils under conventional and organic production protocols, and to reflect tree performance, were tested in a maturing 'Cripps Pink'/M7 apple orchard. Activities of β-glucosidase, phosphatase and urease were determined colourimetrically in extracts of tree-row top-soils (0-15 cm) taken during September and January over five consecutive seasons. Soil organic matter content was determined by dichromate oxidation. Stem circumference and yield were measured manually. AI3 correlated significantly (p = 0.05) with soil organic matter, yield and yield efficiency. AI3 may thus be a useful indicator of relative apple tree performance under organic and conventional soil surface management practices.
- Full Text:
- Date Issued: 2014
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444038 , vital:74180 , https://hdl.handle.net/10520/EJC157392
- Description: Alteration index three (AI3), which calculates the balances between three microbially-secreted enzymes, potentially enables differences between soils due to contrasting management practices to be quantified in relative terms. The ability of AI3 to distinguish between apple orchard soils under conventional and organic production protocols, and to reflect tree performance, were tested in a maturing 'Cripps Pink'/M7 apple orchard. Activities of β-glucosidase, phosphatase and urease were determined colourimetrically in extracts of tree-row top-soils (0-15 cm) taken during September and January over five consecutive seasons. Soil organic matter content was determined by dichromate oxidation. Stem circumference and yield were measured manually. AI3 correlated significantly (p = 0.05) with soil organic matter, yield and yield efficiency. AI3 may thus be a useful indicator of relative apple tree performance under organic and conventional soil surface management practices.
- Full Text:
- Date Issued: 2014
Review: Recent theorisations of trauma fiction, postcolonialism, and the south African novel
- Authors: Njovane, Thando
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458635 , vital:75757 , https://hdl.handle.net/10520/EJC156467
- Description: Drawing on both psychological and sociological definitions of trauma, the essay collection The Splintered Glass engages with the intersection between individual and cultural trauma, while simultaneously warning against the blurring of the distinction between the two. In line with this, trauma is defined not only as a "wound of the mind" of an individual, but also as a "link between cultures" (x). While bearing a remarkable resemblance to the Freudian haunting inherent in most definitions of historical trauma (see also Erikson, Tal and Caruth), the concept of cultural trauma, as utilised in this collection, is situated in the present and seeks to transcend this haunting by gesturing towards a "safe post-traumatic space" (6). A traumatic history "established and sustained by power structures, social agents and contending groups" in a "constant, recurrent struggle that stirs up a troubling memory" (xii) is shared by many, if not all, postcolonial societies.
- Full Text:
- Date Issued: 2014
- Authors: Njovane, Thando
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458635 , vital:75757 , https://hdl.handle.net/10520/EJC156467
- Description: Drawing on both psychological and sociological definitions of trauma, the essay collection The Splintered Glass engages with the intersection between individual and cultural trauma, while simultaneously warning against the blurring of the distinction between the two. In line with this, trauma is defined not only as a "wound of the mind" of an individual, but also as a "link between cultures" (x). While bearing a remarkable resemblance to the Freudian haunting inherent in most definitions of historical trauma (see also Erikson, Tal and Caruth), the concept of cultural trauma, as utilised in this collection, is situated in the present and seeks to transcend this haunting by gesturing towards a "safe post-traumatic space" (6). A traumatic history "established and sustained by power structures, social agents and contending groups" in a "constant, recurrent struggle that stirs up a troubling memory" (xii) is shared by many, if not all, postcolonial societies.
- Full Text:
- Date Issued: 2014
Seamus Heaney in Grahamstown tribute
- Authors: Van Wyk Smith, Malvern
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458311 , vital:75731 , https://hdl.handle.net/10520/EJC156479
- Description: Seamus Heaney, internationally celebrated poet of Ireland and winner of the Nobel Prize in 1995, died in Dublin on Friday 30 August 2013, aged 74. He and his wife Marie paid a memorable visit to South Africa in 2002 and what follows is a short account of the occasion.
- Full Text:
- Date Issued: 2014
- Authors: Van Wyk Smith, Malvern
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458311 , vital:75731 , https://hdl.handle.net/10520/EJC156479
- Description: Seamus Heaney, internationally celebrated poet of Ireland and winner of the Nobel Prize in 1995, died in Dublin on Friday 30 August 2013, aged 74. He and his wife Marie paid a memorable visit to South Africa in 2002 and what follows is a short account of the occasion.
- Full Text:
- Date Issued: 2014
Selective modulation of plasmodial Hsp70s by small molecules with antimalarial activity
- Cockburn, Ingrid L, Boshoff, Aileen, Pesce, Eva-Rachele, Blatch, Gregory L
- Authors: Cockburn, Ingrid L , Boshoff, Aileen , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431192 , vital:72752 , xlink:href="https://doi.org/10.1515/hsz-2014-0138"
- Description: Plasmodial heat shock protein 70 (Hsp70) chaperones represent a promising new class of antimalarial drug targets because of the important roles they play in the survival and pathogenesis of the malaria parasite Plasmodium falciparum. This study assessed a set of small molecules (lapachol, bromo-β-lapachona and malonganenones A, B and C) as potential modulators of two biologically important plasmodial Hsp70s, the parasite-resident PfHsp70-1 and the exported PfHsp70-x. Compounds of interest were assessed for modulatory effects on the steady-state basal and heat shock protein 40 (Hsp40)-stimulated ATPase activities of PfHsp70-1, PfHsp70-x and human Hsp70, as well as on the protein aggregation suppression activity of PfHsp70-x. The antimalarial marine alkaloid malonganenone A was of particular interest, as it was found to have limited cytotoxicity to mammalian cell lines and exhibited the desired properties of an effective plasmodial Hsp70 modulator. This compound was found to inhibit plasmodial and not human Hsp70 ATPase activity (Hsp40-stimulated), and hindered the aggregation suppression activity of PfHsp70-x. Furthermore, malonganenone A was shown to disrupt the interaction between PfHsp70-x and Hsp40. This is the first report to show that PfHsp70-x has chaperone activity, is stimulated by Hsp40 and can be specifically modulated by small molecule compounds.
- Full Text:
- Date Issued: 2014
- Authors: Cockburn, Ingrid L , Boshoff, Aileen , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431192 , vital:72752 , xlink:href="https://doi.org/10.1515/hsz-2014-0138"
- Description: Plasmodial heat shock protein 70 (Hsp70) chaperones represent a promising new class of antimalarial drug targets because of the important roles they play in the survival and pathogenesis of the malaria parasite Plasmodium falciparum. This study assessed a set of small molecules (lapachol, bromo-β-lapachona and malonganenones A, B and C) as potential modulators of two biologically important plasmodial Hsp70s, the parasite-resident PfHsp70-1 and the exported PfHsp70-x. Compounds of interest were assessed for modulatory effects on the steady-state basal and heat shock protein 40 (Hsp40)-stimulated ATPase activities of PfHsp70-1, PfHsp70-x and human Hsp70, as well as on the protein aggregation suppression activity of PfHsp70-x. The antimalarial marine alkaloid malonganenone A was of particular interest, as it was found to have limited cytotoxicity to mammalian cell lines and exhibited the desired properties of an effective plasmodial Hsp70 modulator. This compound was found to inhibit plasmodial and not human Hsp70 ATPase activity (Hsp40-stimulated), and hindered the aggregation suppression activity of PfHsp70-x. Furthermore, malonganenone A was shown to disrupt the interaction between PfHsp70-x and Hsp40. This is the first report to show that PfHsp70-x has chaperone activity, is stimulated by Hsp40 and can be specifically modulated by small molecule compounds.
- Full Text:
- Date Issued: 2014
Spectral properties and photophysical behaviour of water soluble cationic Mg (II) and Al (III) phthalocyanines
- Idowu, Mopelola A, Arslanoğlu, Yasin, Nyokong, Tebello
- Authors: Idowu, Mopelola A , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241549 , vital:50949 , xlink:href="https://doi.org/10.2478/s11532-013-0388-z"
- Description: Peripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA).
- Full Text:
- Date Issued: 2014
- Authors: Idowu, Mopelola A , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241549 , vital:50949 , xlink:href="https://doi.org/10.2478/s11532-013-0388-z"
- Description: Peripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA).
- Full Text:
- Date Issued: 2014
Stable isotope evidence of food web connectivity by a top predatory fish (Argyrosomus japonicus: Sciaenidae: Teleostei) in the Kowie Estuary, South Africa
- Bergamino, Leandro, Dalu, Tatenda, Whitfield, Alan K, Carassou, Laure, Richoux, Nicole B
- Authors: Bergamino, Leandro , Dalu, Tatenda , Whitfield, Alan K , Carassou, Laure , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457322 , vital:75625 , xlink:href="https://doi.org/10.2989/1814232X.2014.923782"
- Description: In this study, food web connectivity within the Kowie Estuary on the south-east coast of South Africa was evidenced by the trophic behaviour of the predominantly piscivorous Argyrosomus japonicus. We examined stable isotopes of carbon (δ13C) and nitrogen (δ15N) in the dominant consumers (zooplankton, invertebrates and fishes) and food sources (particulate organic matter, epibionts and benthic microalgae) in the system. An SIAR (Stable Isotope Analysis in R) mixing model was used to interpret the possible food sources for this dominant top predatory fish. Small fishes and large epibenthic invertebrates dominated the diet of A. japonicus. Based on the contrasting diet of these prey fish and invertebrates, we propose that organic matter enters the predatory fish community via two major pathways: (1) a littoral pathway dominated by benthic microalgae production and epibionts, and (2) a channel pathway dominated by suspended particulate organic matter (including phytoplankton). We conclude that the highly mobile A. japonicus consumes both pelagic and benthic fauna from the littoral and channel zones of the estuary, thereby playing a key functional role in linking food webs. This dietary diversity may help explain the success of A. japonicus as a dominant top predator in the system, primarily by increasing the energy available to this species.
- Full Text:
- Date Issued: 2014
- Authors: Bergamino, Leandro , Dalu, Tatenda , Whitfield, Alan K , Carassou, Laure , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457322 , vital:75625 , xlink:href="https://doi.org/10.2989/1814232X.2014.923782"
- Description: In this study, food web connectivity within the Kowie Estuary on the south-east coast of South Africa was evidenced by the trophic behaviour of the predominantly piscivorous Argyrosomus japonicus. We examined stable isotopes of carbon (δ13C) and nitrogen (δ15N) in the dominant consumers (zooplankton, invertebrates and fishes) and food sources (particulate organic matter, epibionts and benthic microalgae) in the system. An SIAR (Stable Isotope Analysis in R) mixing model was used to interpret the possible food sources for this dominant top predatory fish. Small fishes and large epibenthic invertebrates dominated the diet of A. japonicus. Based on the contrasting diet of these prey fish and invertebrates, we propose that organic matter enters the predatory fish community via two major pathways: (1) a littoral pathway dominated by benthic microalgae production and epibionts, and (2) a channel pathway dominated by suspended particulate organic matter (including phytoplankton). We conclude that the highly mobile A. japonicus consumes both pelagic and benthic fauna from the littoral and channel zones of the estuary, thereby playing a key functional role in linking food webs. This dietary diversity may help explain the success of A. japonicus as a dominant top predator in the system, primarily by increasing the energy available to this species.
- Full Text:
- Date Issued: 2014
Successful identification of the final instar nymph of Quintilia carinata (Thunberg)(Hemiptera: Cicadidae) by DNA extraction from the exuvium
- Bouwer, Nicolette, Midgley, John M, Timm, Alicia E, Villet, Martin H
- Authors: Bouwer, Nicolette , Midgley, John M , Timm, Alicia E , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442347 , vital:73977 , https://doi.org/10.1080/00222933.2013.836759
- Description: Despite being taxonomically and phylogenetically informative, the morphology of the immature stages of cicadas has received comparatively superficial attention. One reason for this is the difficulty of positively identifying immature stages, particularly as these stages are fossorial. We present a method for identifying cicada exuviae using DNA sequence data and describe a set of characters and character states for the final instar nymph of Quintilia carinata (Thunberg). The identification of immature stages using molecular methods will increase our knowledge of African cicadas, allowing for the initiation of future phylogenetic and ecological comparisons.
- Full Text:
- Date Issued: 2014
- Authors: Bouwer, Nicolette , Midgley, John M , Timm, Alicia E , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442347 , vital:73977 , https://doi.org/10.1080/00222933.2013.836759
- Description: Despite being taxonomically and phylogenetically informative, the morphology of the immature stages of cicadas has received comparatively superficial attention. One reason for this is the difficulty of positively identifying immature stages, particularly as these stages are fossorial. We present a method for identifying cicada exuviae using DNA sequence data and describe a set of characters and character states for the final instar nymph of Quintilia carinata (Thunberg). The identification of immature stages using molecular methods will increase our knowledge of African cicadas, allowing for the initiation of future phylogenetic and ecological comparisons.
- Full Text:
- Date Issued: 2014
Sustainability Assessment of University of Gondar, Gondar, North-west Ethiopia
- Moges, Haimanot G, Kifle, Desalegn W, Lotz-Sisitka, Heila, Woldyohhanes, Solomon M
- Authors: Moges, Haimanot G , Kifle, Desalegn W , Lotz-Sisitka, Heila , Woldyohhanes, Solomon M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182845 , vital:43885 , xlink:href="https://doi.org/10.1177/0973408214529990"
- Description: The purpose of this article is to provide an overview of the cross-institutional assessment of sustainable development practices in the University of Gondar (UoG). The focus of the assessment was the level of UoG academic departments’ integration of sustainability concerns in teaching, research and community service. Management contributions to sustainable development, student initiatives on sustainability issues and policy statements about sustainable development of UoG were also considered in the assessment. The data collection was based on the Unit-based Sustainability Assessment Tool (USAT); in addition, supplementary information was collected through observations across the four campuses of UoG from January to February 2012.The result of the assessment showed that only a few academic departments have incorporated sustainability concerns in their curricula and teaching approach. The initiation and commitment of academic departments in mainstreaming sustainability concerns in the research and community service delivered were relatively poor. The operation and management of UoG showed inadequate sustainable development practices on waste management, energy utilization and purchasing from environment-friendly companies. In addition, the written policy and statements of UoG did not reflect sustainability in an explicit manner. The university is expected to respond to the key themes defined through sustainability declarations on higher education; there is also a need to establish the relevance of these in relation to the systemic environment. From the study undertaken, we have learnt that sustainability assessment of universities using USAT will be more valuable, if universities have already initiated the embedding of sustainability so that USAT can be used to benchmark the continual improvement.
- Full Text:
- Date Issued: 2014
- Authors: Moges, Haimanot G , Kifle, Desalegn W , Lotz-Sisitka, Heila , Woldyohhanes, Solomon M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182845 , vital:43885 , xlink:href="https://doi.org/10.1177/0973408214529990"
- Description: The purpose of this article is to provide an overview of the cross-institutional assessment of sustainable development practices in the University of Gondar (UoG). The focus of the assessment was the level of UoG academic departments’ integration of sustainability concerns in teaching, research and community service. Management contributions to sustainable development, student initiatives on sustainability issues and policy statements about sustainable development of UoG were also considered in the assessment. The data collection was based on the Unit-based Sustainability Assessment Tool (USAT); in addition, supplementary information was collected through observations across the four campuses of UoG from January to February 2012.The result of the assessment showed that only a few academic departments have incorporated sustainability concerns in their curricula and teaching approach. The initiation and commitment of academic departments in mainstreaming sustainability concerns in the research and community service delivered were relatively poor. The operation and management of UoG showed inadequate sustainable development practices on waste management, energy utilization and purchasing from environment-friendly companies. In addition, the written policy and statements of UoG did not reflect sustainability in an explicit manner. The university is expected to respond to the key themes defined through sustainability declarations on higher education; there is also a need to establish the relevance of these in relation to the systemic environment. From the study undertaken, we have learnt that sustainability assessment of universities using USAT will be more valuable, if universities have already initiated the embedding of sustainability so that USAT can be used to benchmark the continual improvement.
- Full Text:
- Date Issued: 2014
Synthesis and characterization of quantum dots designed for biomedical use
- Kuzyniak, Weronika, Adegoke, Oluwasesan, Sekhosana, Kutloana E, D'Souza, Sarah, Tshangana, Sesethu Charmaine, Hoffmann, Björn, Ermilov, Eugeny A, Nyokong, Tebello, Höpfner, Michael
- Authors: Kuzyniak, Weronika , Adegoke, Oluwasesan , Sekhosana, Kutloana E , D'Souza, Sarah , Tshangana, Sesethu Charmaine , Hoffmann, Björn , Ermilov, Eugeny A , Nyokong, Tebello , Höpfner, Michael
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241516 , vital:50946 , xlink:href="https://doi.org/10.1016/j.ijpharm.2014.03.037"
- Description: Semiconductor quantum dots (QDs) have become promising nanoparticles for a wide variety of biomedical applications. However, the major drawback of QDs is their potential toxicity. Here, we determined possible cytotoxic effects of a set of QDs by systematic photophysical evaluation in vitro as well as in vivo. QDs were synthesized by the hydrothermal aqueous route with sizes in the range of 2.0–3.5 nm. Cytotoxic effects of QDs were studied in the human pancreatic carcinoid cell line BON. Cadmium telluride QDs with or without zinc sulfide shell and coated with 3-mercaptopropionic acid (MPA) were highly cytotoxic even at nanomolar concentrations. Capping with L-glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of cadmium telluride QDs and cadmium selenide QDs. Determination of the toxicity of QDs revealed IC50 values in the micromolar range. In vivo studies showed good tolerability of CdSe QDs with ZnS shell and GSH capping. We could demonstrate that QDs with ZnS shell and GSH capping exhibit low toxicity and good tolerability in cell models and living organisms. These QDs appear to be promising candidates for biomedical applications such as drug delivery for enhanced chemotherapy or targeted delivery of light sensitive substances for photodynamic therapy.
- Full Text:
- Date Issued: 2014
- Authors: Kuzyniak, Weronika , Adegoke, Oluwasesan , Sekhosana, Kutloana E , D'Souza, Sarah , Tshangana, Sesethu Charmaine , Hoffmann, Björn , Ermilov, Eugeny A , Nyokong, Tebello , Höpfner, Michael
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241516 , vital:50946 , xlink:href="https://doi.org/10.1016/j.ijpharm.2014.03.037"
- Description: Semiconductor quantum dots (QDs) have become promising nanoparticles for a wide variety of biomedical applications. However, the major drawback of QDs is their potential toxicity. Here, we determined possible cytotoxic effects of a set of QDs by systematic photophysical evaluation in vitro as well as in vivo. QDs were synthesized by the hydrothermal aqueous route with sizes in the range of 2.0–3.5 nm. Cytotoxic effects of QDs were studied in the human pancreatic carcinoid cell line BON. Cadmium telluride QDs with or without zinc sulfide shell and coated with 3-mercaptopropionic acid (MPA) were highly cytotoxic even at nanomolar concentrations. Capping with L-glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of cadmium telluride QDs and cadmium selenide QDs. Determination of the toxicity of QDs revealed IC50 values in the micromolar range. In vivo studies showed good tolerability of CdSe QDs with ZnS shell and GSH capping. We could demonstrate that QDs with ZnS shell and GSH capping exhibit low toxicity and good tolerability in cell models and living organisms. These QDs appear to be promising candidates for biomedical applications such as drug delivery for enhanced chemotherapy or targeted delivery of light sensitive substances for photodynamic therapy.
- Full Text:
- Date Issued: 2014
Synthesis and MRSA PK inhibitory activity of thiazole containing deoxytopsentin analogues
- Veale, Clinton G L, Lobb, Kevin A, Zoraghi, Roya, Morrison, James P, Reiner, Neil E, Andersen, Raymond J, Davies-Coleman, Michael T
- Authors: Veale, Clinton G L , Lobb, Kevin A , Zoraghi, Roya , Morrison, James P , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448028 , vital:74692 , xlink:href="https://doi.org/10.1016/j.tet.2014.09.007"
- Description: The public health care crisis caused by the emergence of drug resistant bacterial strains, e.g., methicillin resistant Staphylococcus aureus (MRSA) has underlined the urgent need to accelerate the discovery of new chemical entities active against antibiotic resistant bacteria. We report here the synthesis of a series thiazole containing deoxytopsentin analogues, which show moderate activity against a target MRSA pyruvate kinase enzyme: an evolutionary conserved hub protein critical for bacterial survival. A Hantzsch thiazole coupling between a-oxo-1H-indole-3-thioacetamides and 2-bromo-1-(1H-indol-3-yl)-ethanones provided facile access to the thiazole containing deoxytopsentin compounds.
- Full Text:
- Date Issued: 2014
- Authors: Veale, Clinton G L , Lobb, Kevin A , Zoraghi, Roya , Morrison, James P , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448028 , vital:74692 , xlink:href="https://doi.org/10.1016/j.tet.2014.09.007"
- Description: The public health care crisis caused by the emergence of drug resistant bacterial strains, e.g., methicillin resistant Staphylococcus aureus (MRSA) has underlined the urgent need to accelerate the discovery of new chemical entities active against antibiotic resistant bacteria. We report here the synthesis of a series thiazole containing deoxytopsentin analogues, which show moderate activity against a target MRSA pyruvate kinase enzyme: an evolutionary conserved hub protein critical for bacterial survival. A Hantzsch thiazole coupling between a-oxo-1H-indole-3-thioacetamides and 2-bromo-1-(1H-indol-3-yl)-ethanones provided facile access to the thiazole containing deoxytopsentin compounds.
- Full Text:
- Date Issued: 2014
Synthesis of ytterbium bisphthalocyanines
- Sekhosana, Kutloana E, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189887 , vital:44943 , xlink:href="https://doi.org/10.1016/j.optmat.2014.05.013"
- Description: Herein we report on the syntheses, photophysico-chemical properties and nonlinear absorption parameters of bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-2-yloxy phthalocyaninato)} ytterbium (III) (3) and bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). The fluorescence and singlet oxygen quantum yields obtained for complexes 3 and 4 are low. The triplet quantum yield obtained for complex 3 is high at ΦT = 0.89 whereas for complex 4 ΦT = 0.48. The third order optical susceptibility values are of the order: 10−11 esu (for complex 3), and 10−13 esu (for complex 4) while the hyperpolarizability values are of the order: 10−28 esu (for complex 3) and 10−31 esu (for complex 4). Complexes 3 and 4 show two-photon absorption coefficients of the order of 10−46 cm4 s/photon and 10−48 cm4 s/photon, and threshold intensities as low as 0.3 J cm−2 and 0.0045 J cm−2, respectively.
- Full Text:
- Date Issued: 2014
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189887 , vital:44943 , xlink:href="https://doi.org/10.1016/j.optmat.2014.05.013"
- Description: Herein we report on the syntheses, photophysico-chemical properties and nonlinear absorption parameters of bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-2-yloxy phthalocyaninato)} ytterbium (III) (3) and bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). The fluorescence and singlet oxygen quantum yields obtained for complexes 3 and 4 are low. The triplet quantum yield obtained for complex 3 is high at ΦT = 0.89 whereas for complex 4 ΦT = 0.48. The third order optical susceptibility values are of the order: 10−11 esu (for complex 3), and 10−13 esu (for complex 4) while the hyperpolarizability values are of the order: 10−28 esu (for complex 3) and 10−31 esu (for complex 4). Complexes 3 and 4 show two-photon absorption coefficients of the order of 10−46 cm4 s/photon and 10−48 cm4 s/photon, and threshold intensities as low as 0.3 J cm−2 and 0.0045 J cm−2, respectively.
- Full Text:
- Date Issued: 2014