Forced degradation studies of clobetasol 17‐propionate in methanol, propylene glycol, as bulk drug and cream formulations by RP‐HPLC
- Fauzee, Ayesha F, Walker, Roderick B
- Authors: Fauzee, Ayesha F , Walker, Roderick B
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184005 , vital:44154 , xlink:href="https://doi.org/10.1002/jssc.201200969"
- Description: A rapid, simple, stability-indicating forced degradation study of clobetasol 17-propionate was conducted using RP-HPLC. The method was used to analyze clobetasol 17-propionate in methanol, propylene glycol, and a cream formulation. Isocratic elution of clobetasol and its degradation products was achieved using a Nova-Pak® 4 μm C18 150 mm × 3.9 mm id cartridge column and a mobile phase of methanol: water (68:32 v/v) at a flow rate of 0.9 mL min−1. Quantitation was achieved with UV detection at 239 nm. Nondegraded clobetasol was eluted at a retention time of 6.0 min. Clobetasol 17-propionate was subjected to different stress conditions viz., acidic, basic, heat, oxidation, light, and neutral hydrolysis. The greatest degradation occurred under strong base and oxidative conditions. Strong base-degraded clobetasol produced additional peaks at retention times of 1.8, 4.0, 5.0, and 8.0 min and clobetasol oxidation degradation peaks eluted at 2.2 and 24 min. Complete validation was performed for linearity, accuracy, and precision over the concentration range 0.15–15 μg mL−1. All data were analyzed statistically and this RP-HPLC method proved to be accurate, precise, linear, and stability indicating for the quantitation of clobetasol 17-propionate in methanol, propylene glycol, and cream formulations.
- Full Text:
- Authors: Fauzee, Ayesha F , Walker, Roderick B
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184005 , vital:44154 , xlink:href="https://doi.org/10.1002/jssc.201200969"
- Description: A rapid, simple, stability-indicating forced degradation study of clobetasol 17-propionate was conducted using RP-HPLC. The method was used to analyze clobetasol 17-propionate in methanol, propylene glycol, and a cream formulation. Isocratic elution of clobetasol and its degradation products was achieved using a Nova-Pak® 4 μm C18 150 mm × 3.9 mm id cartridge column and a mobile phase of methanol: water (68:32 v/v) at a flow rate of 0.9 mL min−1. Quantitation was achieved with UV detection at 239 nm. Nondegraded clobetasol was eluted at a retention time of 6.0 min. Clobetasol 17-propionate was subjected to different stress conditions viz., acidic, basic, heat, oxidation, light, and neutral hydrolysis. The greatest degradation occurred under strong base and oxidative conditions. Strong base-degraded clobetasol produced additional peaks at retention times of 1.8, 4.0, 5.0, and 8.0 min and clobetasol oxidation degradation peaks eluted at 2.2 and 24 min. Complete validation was performed for linearity, accuracy, and precision over the concentration range 0.15–15 μg mL−1. All data were analyzed statistically and this RP-HPLC method proved to be accurate, precise, linear, and stability indicating for the quantitation of clobetasol 17-propionate in methanol, propylene glycol, and cream formulations.
- Full Text:
Gazing at Exhibit A
- Authors: Krueger, Anton
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229643 , vital:49696 , xlink:href="http://liminalities.net/9-1/exhibit.pdf"
- Description: Brett Bailey recently toured a new work in Europe and South Africa, called The Exhibit Series (2010-2013). In different countries the work has appeared under different titles—Exhibit A and Exhibit B, while Exhibit C will be produced in 2014. These productions replicate and parody ethnographic spectacles of the nineteenth century, interrogating European colonial atrocities in Africa, as well as contemporary xenophobia. They consist of a series of installations housed in individual rooms that audience members enter one by one. Inside these rooms one is confronted by beautifully arranged spectacles referencing historical atrocities committed in Namibia by German speaking peoples, as well as atrocities under the Belgian and French colonial regimes in the two Congos. The “exhibits” also include references to more recent incidents of European racism against migrants from Africa. The work has been both applauded and derided. In Berlin, for example, activists called it “a human zoo” and protested that this was “the wrong way to discuss a violent colonial history,”1 while others have called the work “haunting”, praising the production for its “dignity” and “beauty.”2
- Full Text:
- Authors: Krueger, Anton
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229643 , vital:49696 , xlink:href="http://liminalities.net/9-1/exhibit.pdf"
- Description: Brett Bailey recently toured a new work in Europe and South Africa, called The Exhibit Series (2010-2013). In different countries the work has appeared under different titles—Exhibit A and Exhibit B, while Exhibit C will be produced in 2014. These productions replicate and parody ethnographic spectacles of the nineteenth century, interrogating European colonial atrocities in Africa, as well as contemporary xenophobia. They consist of a series of installations housed in individual rooms that audience members enter one by one. Inside these rooms one is confronted by beautifully arranged spectacles referencing historical atrocities committed in Namibia by German speaking peoples, as well as atrocities under the Belgian and French colonial regimes in the two Congos. The “exhibits” also include references to more recent incidents of European racism against migrants from Africa. The work has been both applauded and derided. In Berlin, for example, activists called it “a human zoo” and protested that this was “the wrong way to discuss a violent colonial history,”1 while others have called the work “haunting”, praising the production for its “dignity” and “beauty.”2
- Full Text:
Glutathione capped CdTe@ ZnS quantum dots–zinc tetracarboxy phthalocyanine conjugates
- Sekhosana, Kutloana E, Antunes, Edith M, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193780 , vital:45395 , xlink:href="https://doi.org/10.1016/j.poly.2013.02.060"
- Description: Conjugates of zinc tetracarboxy phthalocyanine (ZnPc(COOH)4) with CdTe@ZnS–GSH quantum dots (QDs) were synthesized and characterized by several techniques including X-ray powder diffraction and infrared spectroscopy. There was an observed decrease in both the fluorescence quantum yields and lifetimes of the quantum dots when they were linked or mixed with ZnPc(COOH)4 due to Förster resonance energy transfer (FRET). The FRET behavior of CdTe@ZnS–GSH–ZnPc(COOH)4 conjugates was compared to that of CdTe@ZnS–GSH–ZnPc(COOH)8. Higher FRET efficiencies were observed for CdTe@ZnS–GSH–ZnPc(COOH)4-mixed or CdTe@ZnS–GSH–ZnPc(COOH)4-linked compared to the corresponding CdTe@ZnS–GSH–ZnPc(COOH)8-mixed or CdTe@ZnS–GSH–ZnPc(COOH)8-linked. Also CdTe@ZnS–GSH–ZnPc(COOH)4-mixed (containing coreshell QDs) showed higher FRET efficiency than CdTE–TGA–ZnPc(COOH)4-mixed containing core QDs. The FRET efficiencies were found to be 63% and 59% for the CdTe@ZnS–GSH–ZnPc(COOH)4-linked and CdTe@ZnS–GSH–ZnPc(COOH)4-mixed samples, respectively.
- Full Text:
- Authors: Sekhosana, Kutloana E , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193780 , vital:45395 , xlink:href="https://doi.org/10.1016/j.poly.2013.02.060"
- Description: Conjugates of zinc tetracarboxy phthalocyanine (ZnPc(COOH)4) with CdTe@ZnS–GSH quantum dots (QDs) were synthesized and characterized by several techniques including X-ray powder diffraction and infrared spectroscopy. There was an observed decrease in both the fluorescence quantum yields and lifetimes of the quantum dots when they were linked or mixed with ZnPc(COOH)4 due to Förster resonance energy transfer (FRET). The FRET behavior of CdTe@ZnS–GSH–ZnPc(COOH)4 conjugates was compared to that of CdTe@ZnS–GSH–ZnPc(COOH)8. Higher FRET efficiencies were observed for CdTe@ZnS–GSH–ZnPc(COOH)4-mixed or CdTe@ZnS–GSH–ZnPc(COOH)4-linked compared to the corresponding CdTe@ZnS–GSH–ZnPc(COOH)8-mixed or CdTe@ZnS–GSH–ZnPc(COOH)8-linked. Also CdTe@ZnS–GSH–ZnPc(COOH)4-mixed (containing coreshell QDs) showed higher FRET efficiency than CdTE–TGA–ZnPc(COOH)4-mixed containing core QDs. The FRET efficiencies were found to be 63% and 59% for the CdTe@ZnS–GSH–ZnPc(COOH)4-linked and CdTe@ZnS–GSH–ZnPc(COOH)4-mixed samples, respectively.
- Full Text:
Identity and origins of introduced and native Azolla species in Florida
- Madeira, Paul T, Center, Ted D, Coetzee, Julie A, Pemberton, Robert W, Purcell, Matthew F, Hill, Martin P
- Authors: Madeira, Paul T , Center, Ted D , Coetzee, Julie A , Pemberton, Robert W , Purcell, Matthew F , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419313 , vital:71634 , xlink:href="https://doi.org/10.1016/j.aquabot.2013.07.009"
- Description: Azolla pinnata, an introduced aquatic fern, is spreading rapidly causing concern that it may displace native Azolla. It is now present in the Arthur R. Marshall Loxahatchee National Wildlife Refuge, the northernmost portion of the Florida Everglades. Because A. pinnata subspecies are native to Africa, Southeast Asia, and Australia, determining the actual geographic origin of the Florida exotic is important to the discovery of efficacious biological control agents. Both the exotic and native Azollas were examined using morphological and molecular criteria. Both criteria distinguished three A. pinnata subspecies with the Florida exotic matching the Australian A. pinnata subsp. pinnata. Molecular divergence between the A. pinnata subspecies indicates the three types should be considered separate species. The Florida native was characterized by both molecular and morphological methods as Azolla caroliniana. The discovery of a previously uncharacterized Ecuadorian Azolla, which appears to be a paternal ancestor of A. caroliniana, indicates that A. caroliniana is a hybrid species.
- Full Text:
- Authors: Madeira, Paul T , Center, Ted D , Coetzee, Julie A , Pemberton, Robert W , Purcell, Matthew F , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419313 , vital:71634 , xlink:href="https://doi.org/10.1016/j.aquabot.2013.07.009"
- Description: Azolla pinnata, an introduced aquatic fern, is spreading rapidly causing concern that it may displace native Azolla. It is now present in the Arthur R. Marshall Loxahatchee National Wildlife Refuge, the northernmost portion of the Florida Everglades. Because A. pinnata subspecies are native to Africa, Southeast Asia, and Australia, determining the actual geographic origin of the Florida exotic is important to the discovery of efficacious biological control agents. Both the exotic and native Azollas were examined using morphological and molecular criteria. Both criteria distinguished three A. pinnata subspecies with the Florida exotic matching the Australian A. pinnata subsp. pinnata. Molecular divergence between the A. pinnata subspecies indicates the three types should be considered separate species. The Florida native was characterized by both molecular and morphological methods as Azolla caroliniana. The discovery of a previously uncharacterized Ecuadorian Azolla, which appears to be a paternal ancestor of A. caroliniana, indicates that A. caroliniana is a hybrid species.
- Full Text:
Impact of insecticides on the reproductive potential of false codling moth, Thaumatotibia leucotreta (Meyrick, 1913)(Lepidoptera: Tortricidae)
- Authors: Fullard, T , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406092 , vital:70238 , xlink:href="https://hdl.handle.net/10520/EJC141302"
- Description: False codling moth, Thaumatotibia leucotreta(Meyrick, 1913) (Lepidoptera: Tortricidae), is animportant pest on citrus in South Africa. Several new insecticides were screened for theirpotential negative impacts onT. leucotreta’s reproduction through topical insecticide applica-tions and detached fruit bioassays. Detached fruit bioassays showed that the registeredstandard concentration of Delegate®20 g/100 l and DPX-HGW86 35 ml/100 l caused femalesto oviposit significantly fewer eggs (P= 0.0016) than the controls. The same was found forthe registered concentration of Coragen® (P is less than 0.0001). Topical insecticide trials showed thatonly concentrations of Coragen®, at the registered field rate and above had an effect on themoths’ reproductive output (P is less than 0.0001). Alsystin®and Meothrin™, which were used asindustry standards, did not negatively affect the reproductive output of the moths duringtopical or detached fruit bioassay trials. This study helps to better understand the impor-tance of the application mode,i.e.directly on moths or fruit and implies secondary benefits tosome insecticide applications.
- Full Text:
- Authors: Fullard, T , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406092 , vital:70238 , xlink:href="https://hdl.handle.net/10520/EJC141302"
- Description: False codling moth, Thaumatotibia leucotreta(Meyrick, 1913) (Lepidoptera: Tortricidae), is animportant pest on citrus in South Africa. Several new insecticides were screened for theirpotential negative impacts onT. leucotreta’s reproduction through topical insecticide applica-tions and detached fruit bioassays. Detached fruit bioassays showed that the registeredstandard concentration of Delegate®20 g/100 l and DPX-HGW86 35 ml/100 l caused femalesto oviposit significantly fewer eggs (P= 0.0016) than the controls. The same was found forthe registered concentration of Coragen® (P is less than 0.0001). Topical insecticide trials showed thatonly concentrations of Coragen®, at the registered field rate and above had an effect on themoths’ reproductive output (P is less than 0.0001). Alsystin®and Meothrin™, which were used asindustry standards, did not negatively affect the reproductive output of the moths duringtopical or detached fruit bioassay trials. This study helps to better understand the impor-tance of the application mode,i.e.directly on moths or fruit and implies secondary benefits tosome insecticide applications.
- Full Text:
Impacts of a sub-lethal dose of glyphosate on water hyacinth nutrients and its indirect effects on Neochetina weevils
- Katembo, Naweji, Hill, Martin P, Byrne, Marcus J
- Authors: Katembo, Naweji , Hill, Martin P , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417726 , vital:71481 , xlink:href="https://doi.org/10.1080/09583157.2013.839982"
- Description: A sub-lethal dose of a herbicide under field conditions was applied to determine if it stimulates an increase in water hyacinth nutrients, thereby increasing feeding intensity by Neochetina spp. weevils used as biocontrol agents of the weed. Nitrogen (N) and carbon (C) were measured and compared between sprayed plants and control plants. At one site (Delta Park), N levels were lower in the sprayed plants compared to the control plants both in the leaves and the crown. At the second site (Farm Dam), leaf N was also lower in the sprayed plants than in the control plants, while no difference was found in crown N. Mean number of feeding scars per cm2 at Delta Park was significantly higher on the sprayed plants compared to the control plants, while no significant difference was found at Farm Dam. At Delta Park, there was no correlation, however, between the number of weevil feeding scars and leaf N or C:N ratio in sprayed plants. In conclusion, the sub-lethal dose of glyphosate did not directly result in an increase in weevil feeding intensity but it can be recommended in an integrated control system to retard water hyacinth growth while conserving the weevil population.
- Full Text:
- Authors: Katembo, Naweji , Hill, Martin P , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417726 , vital:71481 , xlink:href="https://doi.org/10.1080/09583157.2013.839982"
- Description: A sub-lethal dose of a herbicide under field conditions was applied to determine if it stimulates an increase in water hyacinth nutrients, thereby increasing feeding intensity by Neochetina spp. weevils used as biocontrol agents of the weed. Nitrogen (N) and carbon (C) were measured and compared between sprayed plants and control plants. At one site (Delta Park), N levels were lower in the sprayed plants compared to the control plants both in the leaves and the crown. At the second site (Farm Dam), leaf N was also lower in the sprayed plants than in the control plants, while no difference was found in crown N. Mean number of feeding scars per cm2 at Delta Park was significantly higher on the sprayed plants compared to the control plants, while no significant difference was found at Farm Dam. At Delta Park, there was no correlation, however, between the number of weevil feeding scars and leaf N or C:N ratio in sprayed plants. In conclusion, the sub-lethal dose of glyphosate did not directly result in an increase in weevil feeding intensity but it can be recommended in an integrated control system to retard water hyacinth growth while conserving the weevil population.
- Full Text:
Influence of nanoparticle materials on the photophysical behavior of phthalocyanines
- Nyokong, Tebello, Antunes, Edith M
- Authors: Nyokong, Tebello , Antunes, Edith M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190450 , vital:44995 , xlink:href="https://doi.org/10.1016/j.ccr.2013.03.016"
- Description: This review presents recent data on the photophysical behavior of phthalocyanines when conjugated to quantum dots, gold and magnetic nanoparticles. In some cases such conjugates offer the possibility of being used in “combination therapy”, where two or more substances may be used for treating one disease. The review focuses on the effect that the presence of nanoparticles has on the excited and triplet state parameters of the phthalocyanines. Five tables listing these parameters are presented.
- Full Text:
- Authors: Nyokong, Tebello , Antunes, Edith M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190450 , vital:44995 , xlink:href="https://doi.org/10.1016/j.ccr.2013.03.016"
- Description: This review presents recent data on the photophysical behavior of phthalocyanines when conjugated to quantum dots, gold and magnetic nanoparticles. In some cases such conjugates offer the possibility of being used in “combination therapy”, where two or more substances may be used for treating one disease. The review focuses on the effect that the presence of nanoparticles has on the excited and triplet state parameters of the phthalocyanines. Five tables listing these parameters are presented.
- Full Text:
Introducing a Critical Pedagogy of Sexual and Reproductive Citizenship: Extending the ‘Framework of Thick Desire'
- Macleod, Catriona I, Vincent, Louise
- Authors: Macleod, Catriona I , Vincent, Louise
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434411 , vital:73056 , ISBN 978-1-4899-8025-0 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780203069141-7/introducing-critical-pedagogy-sexual-reproductive-citizenship-catriona-macleod-louise-vincent
- Description: In Michelle Fine’s influential 1988 paper,‘Sexuality, Schooling, and Adolescent Females: The Missing Discourse of Desire’, she examined the “desires, fears, and fantasies”(p. 30) shaping responses to sex education in the United States in the 1980s. Fine’s work encouraged a ‘turn to pleasure’in sexuality education research. This work focused on and critiqued Fine’s idea, elaborated below, of a ‘missing discourse of desire’in the education of young people and of young women in particular (see for instance Allen, 2004, 2005; Connell, 2005; Rasmussen, 2004, 2012; Tolman, 1994; Vance, 1993). Less taken up, however, was a second major thread in Fine’s 1988 paper, namely the ‘absence of entitlement’in which she argued that not only the absence of a discourse of desire but also the absence of “viable life options” for young women combined to produce their vulnerability (Fine, 1988, p. 49). Almost twenty years later, in a 2006 article, Fine, with Sara McClelland, revisited the missing discourse of desire, this time in the context of an educational crusade in the United States advocating Abstinence Only Until Marriage (AOUM) approaches to sexuality education.
- Full Text:
- Authors: Macleod, Catriona I , Vincent, Louise
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434411 , vital:73056 , ISBN 978-1-4899-8025-0 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780203069141-7/introducing-critical-pedagogy-sexual-reproductive-citizenship-catriona-macleod-louise-vincent
- Description: In Michelle Fine’s influential 1988 paper,‘Sexuality, Schooling, and Adolescent Females: The Missing Discourse of Desire’, she examined the “desires, fears, and fantasies”(p. 30) shaping responses to sex education in the United States in the 1980s. Fine’s work encouraged a ‘turn to pleasure’in sexuality education research. This work focused on and critiqued Fine’s idea, elaborated below, of a ‘missing discourse of desire’in the education of young people and of young women in particular (see for instance Allen, 2004, 2005; Connell, 2005; Rasmussen, 2004, 2012; Tolman, 1994; Vance, 1993). Less taken up, however, was a second major thread in Fine’s 1988 paper, namely the ‘absence of entitlement’in which she argued that not only the absence of a discourse of desire but also the absence of “viable life options” for young women combined to produce their vulnerability (Fine, 1988, p. 49). Almost twenty years later, in a 2006 article, Fine, with Sara McClelland, revisited the missing discourse of desire, this time in the context of an educational crusade in the United States advocating Abstinence Only Until Marriage (AOUM) approaches to sexuality education.
- Full Text:
Is classical biological control a 20th century" old science" paradigm that is losing its way?
- Sheppard, Andy, Werner, K, Hill, Martin P, McEvoy, Peter, Fowler, Simon, Hill, Richard
- Authors: Sheppard, Andy , Werner, K , Hill, Martin P , McEvoy, Peter , Fowler, Simon , Hill, Richard
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425434 , vital:72239 , xlink:href="https://www.fs.usda.gov/research/treesearch/44754"
- Description: For years most countries accepted the benefits of biological control as given, leading to facilitated inside lanes through the regulatory maze. "Successes" led to many passionate disciples over science rationalists. Biocontrol targets continue to be selected on assumptions of good value with little direct evidence. Even when successful, biocontrol has rarely delivered environmental benefits that have been measured. Money flow is still healthy, but is arguably being directed against less impactful targets. Lack of science rigour exposes the field to attacks from an increasing number of critics as values change. A global change driven counter-revolution is underway on the dichotomy of hate between natives and aliens. Will climate change undermine even currently successful biocontrol outcomes? Meanwhile negative direct and indirect impacts of biological continue to fuel dissent. Nowhere is this issue hotter than in Hawaii where "invaders" have massively increased biodiversity, make up nearly all the biomass and create whole new ecosystems. This workshop will entertain a panel discussion around the future for classical biological control of weeds. Does it need to change its paradigm in response to changing societal values, if so can it reinvent itself?
- Full Text:
- Authors: Sheppard, Andy , Werner, K , Hill, Martin P , McEvoy, Peter , Fowler, Simon , Hill, Richard
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425434 , vital:72239 , xlink:href="https://www.fs.usda.gov/research/treesearch/44754"
- Description: For years most countries accepted the benefits of biological control as given, leading to facilitated inside lanes through the regulatory maze. "Successes" led to many passionate disciples over science rationalists. Biocontrol targets continue to be selected on assumptions of good value with little direct evidence. Even when successful, biocontrol has rarely delivered environmental benefits that have been measured. Money flow is still healthy, but is arguably being directed against less impactful targets. Lack of science rigour exposes the field to attacks from an increasing number of critics as values change. A global change driven counter-revolution is underway on the dichotomy of hate between natives and aliens. Will climate change undermine even currently successful biocontrol outcomes? Meanwhile negative direct and indirect impacts of biological continue to fuel dissent. Nowhere is this issue hotter than in Hawaii where "invaders" have massively increased biodiversity, make up nearly all the biomass and create whole new ecosystems. This workshop will entertain a panel discussion around the future for classical biological control of weeds. Does it need to change its paradigm in response to changing societal values, if so can it reinvent itself?
- Full Text:
Land claims and the pursuit of co-management on four protected areas in South Africa
- Cundill, Georgina, Thondhlana, Gladman, Sisitka, Lawrence, Shackleton, Sheona, Blorea, M
- Authors: Cundill, Georgina , Thondhlana, Gladman , Sisitka, Lawrence , Shackleton, Sheona , Blorea, M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391223 , vital:68632 , xlink:href="https://doi.org/10.1016/j.landusepol.2013.05.016"
- Description: Successful land claims on protected areas by previously disenfranchised communities often result in co-management agreements between claimant communities and state conservation agencies. South Africa, in particular, has pursued co-management as the desired outcome of land claims on its protected areas. We review four cases of co-management on protected areas in South Africa, and reflect on the appropriateness of the pursuit of co-management as the preferred outcome of land claims. Despite promises of pro-poor, democratically informed management, the practical experience of co-management has seen the continuation of the status quo in terms of conservation, with very few material benefits for claimant communities and limited sharing of responsibilities and decision-making functions. The findings underscore two deep challenges facing co-management in cases of land claims worldwide. First, during land claims negotiations in cases involving protected areas, the state cannot be expected to represent the best interests of its citizens (the land claimants), while simultaneously seeking to meet national and international obligations for protected area coverage. Second, the concept of democratic co-management may sit uncomfortably beside the realities of managing loss-making protected areas with ever-shrinking conservation budgets. Where co-management agreements have already been signed, ensuring that new landowners do indeed have a say in management should form the driving focus for co-management practice going forward.
- Full Text:
- Authors: Cundill, Georgina , Thondhlana, Gladman , Sisitka, Lawrence , Shackleton, Sheona , Blorea, M
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391223 , vital:68632 , xlink:href="https://doi.org/10.1016/j.landusepol.2013.05.016"
- Description: Successful land claims on protected areas by previously disenfranchised communities often result in co-management agreements between claimant communities and state conservation agencies. South Africa, in particular, has pursued co-management as the desired outcome of land claims on its protected areas. We review four cases of co-management on protected areas in South Africa, and reflect on the appropriateness of the pursuit of co-management as the preferred outcome of land claims. Despite promises of pro-poor, democratically informed management, the practical experience of co-management has seen the continuation of the status quo in terms of conservation, with very few material benefits for claimant communities and limited sharing of responsibilities and decision-making functions. The findings underscore two deep challenges facing co-management in cases of land claims worldwide. First, during land claims negotiations in cases involving protected areas, the state cannot be expected to represent the best interests of its citizens (the land claimants), while simultaneously seeking to meet national and international obligations for protected area coverage. Second, the concept of democratic co-management may sit uncomfortably beside the realities of managing loss-making protected areas with ever-shrinking conservation budgets. Where co-management agreements have already been signed, ensuring that new landowners do indeed have a say in management should form the driving focus for co-management practice going forward.
- Full Text:
MCD spectroscopy and TD-DFT calculations of a naphthalene-ring-bridged coplanar binuclear phthalocyanine dimer
- Mack, John, Liang, Xu, Dubinina, Tatiana V, Tomilova, Larisa G, Nyokong, Tebello, Kobayashi, Nagao
- Authors: Mack, John , Liang, Xu , Dubinina, Tatiana V , Tomilova, Larisa G , Nyokong, Tebello , Kobayashi, Nagao
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232511 , vital:49998 , xlink:href="https://doi.org/10.1142/S1088424613500259"
- Description: Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations are used to analyze the electronic structure and optical properties of an alkyl-substituted naphthalene-ring-bridged coplanar binuclear phthalocyanine dimer. An analysis of the MCD spectrum of the naphthalene-ring-bridged dimer relative to those of benzene-bridged compounds reported previously, demonstrates that there is a significantly weaker interaction between the two phthalocyanine rings. TD-DFT results obtained using the B3LYP functional with 6–31G basis sets were found to be problematic. Closer agreement with the experimental data is obtained when the CAM-B3LYP functional is used instead. The naphthalene-ring-bridged compound is found to be unsuitable for use as a photosensitizer for the formation of singlet oxygen, because the ΦT values are negligible.
- Full Text:
- Authors: Mack, John , Liang, Xu , Dubinina, Tatiana V , Tomilova, Larisa G , Nyokong, Tebello , Kobayashi, Nagao
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232511 , vital:49998 , xlink:href="https://doi.org/10.1142/S1088424613500259"
- Description: Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations are used to analyze the electronic structure and optical properties of an alkyl-substituted naphthalene-ring-bridged coplanar binuclear phthalocyanine dimer. An analysis of the MCD spectrum of the naphthalene-ring-bridged dimer relative to those of benzene-bridged compounds reported previously, demonstrates that there is a significantly weaker interaction between the two phthalocyanine rings. TD-DFT results obtained using the B3LYP functional with 6–31G basis sets were found to be problematic. Closer agreement with the experimental data is obtained when the CAM-B3LYP functional is used instead. The naphthalene-ring-bridged compound is found to be unsuitable for use as a photosensitizer for the formation of singlet oxygen, because the ΦT values are negligible.
- Full Text:
Microbial agents for control of aquatic weeds and their role in integrated management
- Authors: Ray, P , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423550 , vital:72071 , xlink:href="https://www.cabidigitallibrary.org/doi/abs/10.1079/PAVSNNR20128014"
- Description: Aquatic ecosystems throughout the world are threatened by the presence of invasive aquatic plants, both floating and submerged. Some of the aquatic species, such as water hyacinth (Eichhornia crassipes [Mart.] Solms), alligator weed, Alternanthera philoxeroides (Mart.), giant salvinia, Salvinia molesta D.S. Mitchell and water lettuce (Pistia stratiotes L.), Griseb. despite being relatively minor problems in their native range, have become major invaders of aquatic habitats in other parts of the world after having escaped from their natural enemies. Unchecked growth of aquatic vegetation is generally undesirable and reduces the value of the water resource. Despite adopting all control options including manual, mechanical, chemical and classical biological, the problem persists. The current weed management is oriented towards finding approaches that are effective in controlling the weed and reducing environmental contamination from herbicides. Plant pathogens have been gaining increasing attention and interest among those concerned with developing environmentally friendly, effective and compatible approaches for integrated management of the noxious weeds. This paper discusses some of the major microbial agents associated with aquatic weeds and their increasing role in integrated weed management.
- Full Text:
- Authors: Ray, P , Hill, Martin P
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423550 , vital:72071 , xlink:href="https://www.cabidigitallibrary.org/doi/abs/10.1079/PAVSNNR20128014"
- Description: Aquatic ecosystems throughout the world are threatened by the presence of invasive aquatic plants, both floating and submerged. Some of the aquatic species, such as water hyacinth (Eichhornia crassipes [Mart.] Solms), alligator weed, Alternanthera philoxeroides (Mart.), giant salvinia, Salvinia molesta D.S. Mitchell and water lettuce (Pistia stratiotes L.), Griseb. despite being relatively minor problems in their native range, have become major invaders of aquatic habitats in other parts of the world after having escaped from their natural enemies. Unchecked growth of aquatic vegetation is generally undesirable and reduces the value of the water resource. Despite adopting all control options including manual, mechanical, chemical and classical biological, the problem persists. The current weed management is oriented towards finding approaches that are effective in controlling the weed and reducing environmental contamination from herbicides. Plant pathogens have been gaining increasing attention and interest among those concerned with developing environmentally friendly, effective and compatible approaches for integrated management of the noxious weeds. This paper discusses some of the major microbial agents associated with aquatic weeds and their increasing role in integrated weed management.
- Full Text:
Morphological and genetic characterization of a South African Plutella xylostella granulovirus (plxy GV) isolate
- Abdulkadir, Fatima, Marsberg, Tamryn, Knox, Caroline M, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
Nanoconjugates of CdTe@ ZnS quantum dots with cobalt tetraamino-phthalocyanine
- Adegoke, Oluwasesan, Antunes, Edith M, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242049 , vital:50996 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.02.010"
- Description: The covalent linking of thiol-capped CdTe@ZnS QDs with cobalt tetraamino-phthalocyanine (CoTAPc) has been successfully carried out. Several techniques such as time-resolved fluorescence measurements, thermal gravimetric analysis,transmissionelectronmicroscopy andspectrophotometric techniques were employed to characterize the nanoconjugates. Covalent binding of the QDs with CoTAPc resulted in the fluorescence quenching of the former. In the presence of varying concentrations of superoxide anion (O2 •−), the fluorescence of the QDs in the conjugate was gradually enhanced and the detection limits obtained were 2.1 and 2.4 nM for the smaller and larger QDs, respectively. Based on the excellent selectivity displayed by the nanoconjugates towards O2 •− over other biologically active species, a potential nanosensor was developed.
- Full Text:
- Authors: Adegoke, Oluwasesan , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242049 , vital:50996 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.02.010"
- Description: The covalent linking of thiol-capped CdTe@ZnS QDs with cobalt tetraamino-phthalocyanine (CoTAPc) has been successfully carried out. Several techniques such as time-resolved fluorescence measurements, thermal gravimetric analysis,transmissionelectronmicroscopy andspectrophotometric techniques were employed to characterize the nanoconjugates. Covalent binding of the QDs with CoTAPc resulted in the fluorescence quenching of the former. In the presence of varying concentrations of superoxide anion (O2 •−), the fluorescence of the QDs in the conjugate was gradually enhanced and the detection limits obtained were 2.1 and 2.4 nM for the smaller and larger QDs, respectively. Based on the excellent selectivity displayed by the nanoconjugates towards O2 •− over other biologically active species, a potential nanosensor was developed.
- Full Text:
Nonlinear optical behavior of metal octaphenoxy phthalocyanines
- Sanusi, Sikiru O, Antunes, Edith M, Nyokong, Tebello
- Authors: Sanusi, Sikiru O , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241717 , vital:50963 , xlink:href="https://doi.org/10.1142/S1088424613500715"
- Description: In this work, we investigated the nonlinear optical absorption properties of chloroaluminum, chlorogallium, chloroindium, zinc and lead octaphenoxy phthalocyanines in a dimethyl sulphoxide solution using 5 ns pulses at 532 nm. Using the Z-scan technique, the nonlinear optical properties and the excited state absorption cross-sections were determined by fitting the Z-scan data. The k value was the highest for Pb derivative at 211, making it the best nonlinear optical material. In terms of hyperpolarizability, Pb derivative (containing a larger central metal) also gave the largest value followed by aluminum derivative (containing a small central metal). The distortion of the ring caused by the central metal is used to explain the hyperpolarizability values. Large nonlinear absorption coefficient values, βeff, in the range of 3.558–4.763 × 10-9 cm.W-1 and low saturation fluence values, Fsat between 21.5–38.5 mJ.cm-2, were obtained for these samples.
- Full Text:
- Authors: Sanusi, Sikiru O , Antunes, Edith M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241717 , vital:50963 , xlink:href="https://doi.org/10.1142/S1088424613500715"
- Description: In this work, we investigated the nonlinear optical absorption properties of chloroaluminum, chlorogallium, chloroindium, zinc and lead octaphenoxy phthalocyanines in a dimethyl sulphoxide solution using 5 ns pulses at 532 nm. Using the Z-scan technique, the nonlinear optical properties and the excited state absorption cross-sections were determined by fitting the Z-scan data. The k value was the highest for Pb derivative at 211, making it the best nonlinear optical material. In terms of hyperpolarizability, Pb derivative (containing a larger central metal) also gave the largest value followed by aluminum derivative (containing a small central metal). The distortion of the ring caused by the central metal is used to explain the hyperpolarizability values. Large nonlinear absorption coefficient values, βeff, in the range of 3.558–4.763 × 10-9 cm.W-1 and low saturation fluence values, Fsat between 21.5–38.5 mJ.cm-2, were obtained for these samples.
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Nutrient-mediated effects on Cornops aquaticum Brüner (Orthoptera: Acrididae), a potential biological control agent of water hyacinth, Eichhornia crassipes (Mart.) Solms (Pontederiaceae)
- Bownes, Angela, Hill, Martin P, Byrne, Marcus J
- Authors: Bownes, Angela , Hill, Martin P , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406131 , vital:70241 , xlink:href="https://doi.org/10.1016/j.biocontrol.2013.07.023"
- Description: Environmental nutrient availability can drive and modify both plant responses to herbivory by phytophagous insects and insect feeding patterns which, in insect-weed systems, may ultimately determine whether biological control succeeds or fails. The impacts of insect biological control agents on the invasive aquatic weed, water hyacinth (Eichhornia crassipes) vary with nutrient levels in the environment. It was therefore considered important to evaluate nutrient-specific responses of E. crassipes to a grasshopper herbivore, Cornops aquaticum, prior to its release in South Africa. Both plant productivity and the response of E. crassipes to herbivory by C. aquaticum were nutrient dependent. Increases in plant biomass and leaf and ramet production were correlated with increases in nutrients in the water and plant biomass accumulation was reduced by herbivory at all three nutrient levels tested (high = 67%; medium = 100%; low = 400%). C. aquaticum nymphs fed E. crassipes leaves with the lowest nitrogen levels produced the highest biomass of frass during their development, indicating compensatory consumption. The results suggest that environmental nutrient availability will influence efficacy of C. aquaticum. They also provide further evidence that E. crassipes problems are exacerbated by an over-abundance of nutrients in aquatic environments, and that biological control would be a highly effective management tool if aquatic systems in South Africa were less polluted. Additionally, the results also show how an understanding of the fundamental responses of E. crassipes and its insect biocontrol agents to their environment can assist in determining specific management strategies or interventions according to prevailing site-specific conditions.
- Full Text:
- Authors: Bownes, Angela , Hill, Martin P , Byrne, Marcus J
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406131 , vital:70241 , xlink:href="https://doi.org/10.1016/j.biocontrol.2013.07.023"
- Description: Environmental nutrient availability can drive and modify both plant responses to herbivory by phytophagous insects and insect feeding patterns which, in insect-weed systems, may ultimately determine whether biological control succeeds or fails. The impacts of insect biological control agents on the invasive aquatic weed, water hyacinth (Eichhornia crassipes) vary with nutrient levels in the environment. It was therefore considered important to evaluate nutrient-specific responses of E. crassipes to a grasshopper herbivore, Cornops aquaticum, prior to its release in South Africa. Both plant productivity and the response of E. crassipes to herbivory by C. aquaticum were nutrient dependent. Increases in plant biomass and leaf and ramet production were correlated with increases in nutrients in the water and plant biomass accumulation was reduced by herbivory at all three nutrient levels tested (high = 67%; medium = 100%; low = 400%). C. aquaticum nymphs fed E. crassipes leaves with the lowest nitrogen levels produced the highest biomass of frass during their development, indicating compensatory consumption. The results suggest that environmental nutrient availability will influence efficacy of C. aquaticum. They also provide further evidence that E. crassipes problems are exacerbated by an over-abundance of nutrients in aquatic environments, and that biological control would be a highly effective management tool if aquatic systems in South Africa were less polluted. Additionally, the results also show how an understanding of the fundamental responses of E. crassipes and its insect biocontrol agents to their environment can assist in determining specific management strategies or interventions according to prevailing site-specific conditions.
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Optical limiting analysis of phthalocyanines in polymer thin films
- Britton, Jonathan, Litwinski, Christian, Antunes, Edith M, Durmus, Mahmut, Chaukea, Vongani, Nyokong, Tebello
- Authors: Britton, Jonathan , Litwinski, Christian , Antunes, Edith M , Durmus, Mahmut , Chaukea, Vongani , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232488 , vital:49996 , xlink:href="https://doi.org/10.1080/10601325.2013.736269"
- Description: This paper reports on the effect of embedding twelve phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films on their optical limiting abilities. This paper also examines the effect of forming a covalent link between zinc tetraamino phthalocyanine (10) and poly (methyl acrylic acid) (PMAA), and Zn (11) or OHAl (12) octacarboxy phthalocyanines with polyethylenimine (PEI). The average film thickness (for phthalocyanines mixed or linked to polymers) of each Pc/Polymer films on glass was 95 μm. The hyperpolarizability of the twelve phthalocyanines was found to be in the range of 10−26 to 10−24 esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution, which ranged from 10−30 to 10−26 esu.L. Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation.
- Full Text:
- Authors: Britton, Jonathan , Litwinski, Christian , Antunes, Edith M , Durmus, Mahmut , Chaukea, Vongani , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232488 , vital:49996 , xlink:href="https://doi.org/10.1080/10601325.2013.736269"
- Description: This paper reports on the effect of embedding twelve phthalocyanines containing In, Ga, Zn and Al as central metals in polymer thin films on their optical limiting abilities. This paper also examines the effect of forming a covalent link between zinc tetraamino phthalocyanine (10) and poly (methyl acrylic acid) (PMAA), and Zn (11) or OHAl (12) octacarboxy phthalocyanines with polyethylenimine (PEI). The average film thickness (for phthalocyanines mixed or linked to polymers) of each Pc/Polymer films on glass was 95 μm. The hyperpolarizability of the twelve phthalocyanines was found to be in the range of 10−26 to 10−24 esu.L. This is significantly higher than the hyperpolarizabilities of these phthalocyanines in solution, which ranged from 10−30 to 10−26 esu.L. Degradation studies seem to indicate that placing a phthalocyanine within a polymer thin film may protect it slightly from photo- and thermal degradation.
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Overcrowding of false codling moth, Thaumatotibia leucotreta (Meyrick) leads to the isolation of five new Cryptophlebia leucotreta granulovirus (CrleGV-SA) isolates
- Opoku-Debrah, John K, Hill, Martin P, Knox, Caroline, Moore, Sean D
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419360 , vital:71637 , xlink:href="https://doi.org/10.1016/j.jip.2012.12.008"
- Description: False codling moth, Thaumatotibia leucotreta (Meyrick) is a serious pest of economic importance to the South African fruit industry. As part of sustainable efforts to control this pest, biological control options that involve the application of baculovirus-based biopesticides such as Cryptogran and Cryptex (both formulated with a South African isolate of Cryptophlebia leucotreta granulovirus, CrleGV-SA) are popularly used by farmers. In order to safeguard the integrity of these biopesticides as well as protect against any future development of resistance in the host, we conducted a study to bioprospect for additional CrleGV isolates as alternatives to existing ones. Using overcrowding as an induction method for latent infection, we recovered five new CrleGV isolates (CrleGV-SA Ado, CrleGV-SA Mbl, CrleGV-SA Cit, CrleGV-SA MixC and CrleGV-SA Nels). Single restriction endonuclease (REN) analysis of viral genomic DNA extracted from purified occlusion bodies showed that isolates differed in their DNA profiles. Partial sequencing of granulin and egt genes from the different isolates and multiple alignments of nucleotide sequences revealed the presence of single nucleotide polymorphisms (SNPs), some of which resulted in amino acid substitutions in the protein sequence. Based on these findings as well as comparisons with other documented CrleGV isolates, we propose two phylogenetic groups for CrleGV-SA isolates recovered in this study.
- Full Text:
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419360 , vital:71637 , xlink:href="https://doi.org/10.1016/j.jip.2012.12.008"
- Description: False codling moth, Thaumatotibia leucotreta (Meyrick) is a serious pest of economic importance to the South African fruit industry. As part of sustainable efforts to control this pest, biological control options that involve the application of baculovirus-based biopesticides such as Cryptogran and Cryptex (both formulated with a South African isolate of Cryptophlebia leucotreta granulovirus, CrleGV-SA) are popularly used by farmers. In order to safeguard the integrity of these biopesticides as well as protect against any future development of resistance in the host, we conducted a study to bioprospect for additional CrleGV isolates as alternatives to existing ones. Using overcrowding as an induction method for latent infection, we recovered five new CrleGV isolates (CrleGV-SA Ado, CrleGV-SA Mbl, CrleGV-SA Cit, CrleGV-SA MixC and CrleGV-SA Nels). Single restriction endonuclease (REN) analysis of viral genomic DNA extracted from purified occlusion bodies showed that isolates differed in their DNA profiles. Partial sequencing of granulin and egt genes from the different isolates and multiple alignments of nucleotide sequences revealed the presence of single nucleotide polymorphisms (SNPs), some of which resulted in amino acid substitutions in the protein sequence. Based on these findings as well as comparisons with other documented CrleGV isolates, we propose two phylogenetic groups for CrleGV-SA isolates recovered in this study.
- Full Text:
Oxovanadium (IV)-containing poly (styrene-co-4′-ethenyl-2-hydroxyphenylimidazole) electrospun nanofibers for the catalytic oxidation of thioanisole
- Walmsley, Ryan S, Litwinski, Christian, Antunes, Edith M, Hlangothi, Percy, Hosten, Eric, McCleland, Cedric, Nyokong, Tebello, Torto, Nelson, Tshentu, Zenixole R
- Authors: Walmsley, Ryan S , Litwinski, Christian , Antunes, Edith M , Hlangothi, Percy , Hosten, Eric , McCleland, Cedric , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241665 , vital:50959 , xlink:href="https://doi.org/10.1016/j.molcata.2013.07.018"
- Description: The catalytic fibers have been fabricated by the electrospinning of a copolymer of styrene and 2-(2′-hydroxy-4′-ethenylphenyl)imidazole {p(ST-co-VPIM)} followed by a reaction with a methanolic vanadyl solution to afford the oxovanadium(IV)-containing poly(styrene-co-4′-ethenyl-2-hydroxyphenylimidazole) fibers {p(ST-co-VPIM)-VO fibers}. The relationship between polymer concentration and fiber diameter was investigated, and at high concentration (20 wt%) the fibers were quite large (average diameter of 3.8 μm) but as the concentration was reduced fibers of much lower diameter were produced (0.6 μm using 8 wt%). The BET surface area for p(ST-co-VPIM) fibers (0.6 μm diameter) was 47.9 m2 g−1 and functionalization of p(ST-co-VPIM) with vanadyl resulted in an increase in surface area to 60.7 m2 g−1 for p(ST-co-VPIM)-VO. The presence of vanadyl was confirmed by XPS and EPR. The EPR spectral analyses depicted complex speciation of vanadium within these polymer supports. These catalytic fibers were applied under batch and continuous flow conditions for the catalytic oxidation of thioanisole using hydrogen peroxide. The continuous flow method gave excellent and constant conversion throughout the 10 h period studied. The leaching of vanadium from the fiber support was 4% over the 10 h period indicating a significant stability of the material.
- Full Text:
- Authors: Walmsley, Ryan S , Litwinski, Christian , Antunes, Edith M , Hlangothi, Percy , Hosten, Eric , McCleland, Cedric , Nyokong, Tebello , Torto, Nelson , Tshentu, Zenixole R
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241665 , vital:50959 , xlink:href="https://doi.org/10.1016/j.molcata.2013.07.018"
- Description: The catalytic fibers have been fabricated by the electrospinning of a copolymer of styrene and 2-(2′-hydroxy-4′-ethenylphenyl)imidazole {p(ST-co-VPIM)} followed by a reaction with a methanolic vanadyl solution to afford the oxovanadium(IV)-containing poly(styrene-co-4′-ethenyl-2-hydroxyphenylimidazole) fibers {p(ST-co-VPIM)-VO fibers}. The relationship between polymer concentration and fiber diameter was investigated, and at high concentration (20 wt%) the fibers were quite large (average diameter of 3.8 μm) but as the concentration was reduced fibers of much lower diameter were produced (0.6 μm using 8 wt%). The BET surface area for p(ST-co-VPIM) fibers (0.6 μm diameter) was 47.9 m2 g−1 and functionalization of p(ST-co-VPIM) with vanadyl resulted in an increase in surface area to 60.7 m2 g−1 for p(ST-co-VPIM)-VO. The presence of vanadyl was confirmed by XPS and EPR. The EPR spectral analyses depicted complex speciation of vanadium within these polymer supports. These catalytic fibers were applied under batch and continuous flow conditions for the catalytic oxidation of thioanisole using hydrogen peroxide. The continuous flow method gave excellent and constant conversion throughout the 10 h period studied. The leaching of vanadium from the fiber support was 4% over the 10 h period indicating a significant stability of the material.
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Perceptions and use of public green space is influenced by its relative abundance in two small towns in South Africa
- Shackleton, Charlie M, Blair, Andrew
- Authors: Shackleton, Charlie M , Blair, Andrew
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181026 , vital:43688 , xlink:href="https://doi.org/10.1016/j.landurbplan.2013.01.011"
- Description: The challenges in planning and maintaining urban public green spaces in poor towns of the developing world differ markedly from those of the developed world. This paper reports on residents’ perceptions, use and willingness to get involved in urban public green space (PGS) issues in two poor towns in South Africa which differed markedly in the amount of PGS. The disparities in PGS between the two towns were also replicated in different suburbs within the two towns. We hypothesised that levels of dissatisfaction would be highest in those suburbs and the town with the least PGS. The results indicated that the distance from residents’ homesteads to the nearest PGS was similar across towns and suburbs. Most residents felt that having accessible PGS was important, and the majority agreed that there was insufficient PGS in their respective town and suburb, and that the local municipality did not do enough in providing PGS or maintaining what there was. The level of dissatisfaction with the amount and condition of PGS was generally highest in the suburbs and town with the least PGS. Many felt that the municipality had insufficient commitment and funds to adequately maintain PGS, and consequently the willingness of residents to get involved through either a commitment of time or funds was high. The more affluent town and suburbs were willing to pay more than the poorer ones, and the poorer ones were willing to provide more time than the more affluent ones.
- Full Text:
- Authors: Shackleton, Charlie M , Blair, Andrew
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181026 , vital:43688 , xlink:href="https://doi.org/10.1016/j.landurbplan.2013.01.011"
- Description: The challenges in planning and maintaining urban public green spaces in poor towns of the developing world differ markedly from those of the developed world. This paper reports on residents’ perceptions, use and willingness to get involved in urban public green space (PGS) issues in two poor towns in South Africa which differed markedly in the amount of PGS. The disparities in PGS between the two towns were also replicated in different suburbs within the two towns. We hypothesised that levels of dissatisfaction would be highest in those suburbs and the town with the least PGS. The results indicated that the distance from residents’ homesteads to the nearest PGS was similar across towns and suburbs. Most residents felt that having accessible PGS was important, and the majority agreed that there was insufficient PGS in their respective town and suburb, and that the local municipality did not do enough in providing PGS or maintaining what there was. The level of dissatisfaction with the amount and condition of PGS was generally highest in the suburbs and town with the least PGS. Many felt that the municipality had insufficient commitment and funds to adequately maintain PGS, and consequently the willingness of residents to get involved through either a commitment of time or funds was high. The more affluent town and suburbs were willing to pay more than the poorer ones, and the poorer ones were willing to provide more time than the more affluent ones.
- Full Text: