Evaluation of Bacillus thuringiensis Berliner as an alternative control of small hive beetles, Aethina tumida Murray (Coleoptera: Nitidulidae)
- Buchholz, S, Neumann, Peter, Neumann, K, Hepburn, H Randall
- Authors: Buchholz, S , Neumann, Peter , Neumann, K , Hepburn, H Randall
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6929 , http://hdl.handle.net/10962/d1011945
- Description: Small hive beetles, Aethina tumida Murray, are parasites and scavengers of honeybee colonies, Apis mellifera L., and have become an invasive species that can cause considerable damage in its new distribution areas. An effective subspecies of Bacillus thuringiensis Berliner (=Bt) would provide an alternative to chemical control of this pest. Therefore, we tested three different Bt strains [B. thuringiensis, var. aizawai (B401®), B. thuringiensis var. kurstaki (Novodor®) and B. thuringiensis var. San Diego tenebrionis (Jackpot®)] and Perizin® (3.2% coumaphos), each applied on combs with a pollen diet fed to pairs of adult beetles. This evaluates the products for the suppression of successful small hive beetle reproduction. While none of the tested Bt strains showed a significant effect on the number of produced wandering larvae, we could confirm the efficacy of coumaphos for the control of small hive beetles. We further show that it is also efficient when applied with a lower concentration as a liquid on the combs. We suggest the continued search for efficient Bt strains naturally infesting small hive beetles in its endemic and new ranges, which may become a part of the integrated management of this pest.
- Full Text:
- Date Issued: 2006
- Authors: Buchholz, S , Neumann, Peter , Neumann, K , Hepburn, H Randall
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6929 , http://hdl.handle.net/10962/d1011945
- Description: Small hive beetles, Aethina tumida Murray, are parasites and scavengers of honeybee colonies, Apis mellifera L., and have become an invasive species that can cause considerable damage in its new distribution areas. An effective subspecies of Bacillus thuringiensis Berliner (=Bt) would provide an alternative to chemical control of this pest. Therefore, we tested three different Bt strains [B. thuringiensis, var. aizawai (B401®), B. thuringiensis var. kurstaki (Novodor®) and B. thuringiensis var. San Diego tenebrionis (Jackpot®)] and Perizin® (3.2% coumaphos), each applied on combs with a pollen diet fed to pairs of adult beetles. This evaluates the products for the suppression of successful small hive beetle reproduction. While none of the tested Bt strains showed a significant effect on the number of produced wandering larvae, we could confirm the efficacy of coumaphos for the control of small hive beetles. We further show that it is also efficient when applied with a lower concentration as a liquid on the combs. We suggest the continued search for efficient Bt strains naturally infesting small hive beetles in its endemic and new ranges, which may become a part of the integrated management of this pest.
- Full Text:
- Date Issued: 2006
Hydrolytic enzymes in sewage sludge treatment: a mini-review
- Burgess, Jo E, Pletschke, Brett I
- Authors: Burgess, Jo E , Pletschke, Brett I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6478 , http://hdl.handle.net/10962/d1006166 , http://hdl.handle.net/10520/EJC116535
- Description: Biological wastewater treatment processes can be classified as either aerobic or anaerobic. These two biological treatment processes are each characterised by groups of micro-organisms and their associated enzymes. Hydrolytic enzymes secreted by these micro-organisms are vital for the rate-limiting step of hydrolysis in the treatment of highly polymeric substrates present in sewage sludge. In this mini-review, the effects of mass transfer limitation, metabolic intermediates, extracellular polymeric substances (EPS), electron acceptor conditions and pH and temperature on the activity of these enzymes are summarised. The most salient and current perspectives of the significance and the role that hydrolytic enzymes play in sewage sludge treatment are highlighted.
- Full Text:
- Date Issued: 2008
- Authors: Burgess, Jo E , Pletschke, Brett I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6478 , http://hdl.handle.net/10962/d1006166 , http://hdl.handle.net/10520/EJC116535
- Description: Biological wastewater treatment processes can be classified as either aerobic or anaerobic. These two biological treatment processes are each characterised by groups of micro-organisms and their associated enzymes. Hydrolytic enzymes secreted by these micro-organisms are vital for the rate-limiting step of hydrolysis in the treatment of highly polymeric substrates present in sewage sludge. In this mini-review, the effects of mass transfer limitation, metabolic intermediates, extracellular polymeric substances (EPS), electron acceptor conditions and pH and temperature on the activity of these enzymes are summarised. The most salient and current perspectives of the significance and the role that hydrolytic enzymes play in sewage sludge treatment are highlighted.
- Full Text:
- Date Issued: 2008
Life-giving light
- Authors: Burnett, Mary
- Language: English
- Type: Article
- Identifier: vital:7204 , http://hdl.handle.net/10962/d1006403
- Description: Professor Tebello Nyokong of the Department of Chemistry, at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the Atlantic Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
- Authors: Burnett, Mary
- Language: English
- Type: Article
- Identifier: vital:7204 , http://hdl.handle.net/10962/d1006403
- Description: Professor Tebello Nyokong of the Department of Chemistry, at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the Atlantic Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
Research for health and life: life giving light
- Authors: Burnett, Mary
- Date: 2001
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7179 , http://hdl.handle.net/10962/d1006185 , Nyokong, Tebello
- Description: The elimination of certain cancers with light, known as photodynamic therapy, is a relatively new technique that has mainly been used in Russia, the USA and some parts of Europe, but with remarkable effectiveness. Professor Tebello Nyokong of the Department of Chemistry , at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the AtlantIC Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
- Date Issued: 2001
- Authors: Burnett, Mary
- Date: 2001
- Subjects: Nyokong, Tebello
- Language: English
- Type: Article , text
- Identifier: vital:7179 , http://hdl.handle.net/10962/d1006185 , Nyokong, Tebello
- Description: The elimination of certain cancers with light, known as photodynamic therapy, is a relatively new technique that has mainly been used in Russia, the USA and some parts of Europe, but with remarkable effectiveness. Professor Tebello Nyokong of the Department of Chemistry , at Rhodes University, Grahamstown, is collaborating with Professor David Phillips of the Imperial College, London, as part of the AtlantIC Alliance which also involves Emory University, Atlanta and the Georgia Institute of Technology, both in Atlanta, SA.
- Full Text:
- Date Issued: 2001
Diet and daily ration of two nototheniid fish on the shelf of the sub-Antarctic Prince Edward Islands
- Bushula, T, Pakhomov, E A, Kaehler, Sven, Davis, S, Kalin, R M
- Authors: Bushula, T , Pakhomov, E A , Kaehler, Sven , Davis, S , Kalin, R M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6948 , http://hdl.handle.net/10962/d1011977
- Description: The seasonal dietary composition and estimates of daily consumption rate of Lepidonotothen larseni and Gobionotothen marionensis juveniles were obtained for the first time using fish collected near sub-Antarctic Prince Edward Islands during April 1999–2003. The diet of L. larseni consisted mainly of pelagic prey, with copepods and arrow worms making up the most significant prey groups and accounting for 46% and 40% of prey mass, respectively. The diet of G. marionensis was more diverse than that of L. larseni and was composed mainly of benthic prey, including bottom-dwelling decapods (Nauticaris marionis) and sedentary polychaetes, which accounted for 54% and 30% of prey mass, respectively. During the present study, dietary overlap between juveniles of L. larseni and G. marionensis was very low (<5%) indicating that competition for food resources between them was negligible. They not only relied on different prey species, both also exhibited different diel feeding regimes. Daily consumption rate of L. larseni and G. marionensis juveniles was estimated to be 4.5% and 5.2% of body dry mass, respectively. Stomach contents and stable isotope analyses suggested, that both L. larseni and G. marionensis occupy the forth-trophic level of the sub-Antarctic food web but depend mainly on allochthonous and autochthonous (kelp derived) organic matter, respectively.
- Full Text:
- Date Issued: 2005
- Authors: Bushula, T , Pakhomov, E A , Kaehler, Sven , Davis, S , Kalin, R M
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6948 , http://hdl.handle.net/10962/d1011977
- Description: The seasonal dietary composition and estimates of daily consumption rate of Lepidonotothen larseni and Gobionotothen marionensis juveniles were obtained for the first time using fish collected near sub-Antarctic Prince Edward Islands during April 1999–2003. The diet of L. larseni consisted mainly of pelagic prey, with copepods and arrow worms making up the most significant prey groups and accounting for 46% and 40% of prey mass, respectively. The diet of G. marionensis was more diverse than that of L. larseni and was composed mainly of benthic prey, including bottom-dwelling decapods (Nauticaris marionis) and sedentary polychaetes, which accounted for 54% and 30% of prey mass, respectively. During the present study, dietary overlap between juveniles of L. larseni and G. marionensis was very low (<5%) indicating that competition for food resources between them was negligible. They not only relied on different prey species, both also exhibited different diel feeding regimes. Daily consumption rate of L. larseni and G. marionensis juveniles was estimated to be 4.5% and 5.2% of body dry mass, respectively. Stomach contents and stable isotope analyses suggested, that both L. larseni and G. marionensis occupy the forth-trophic level of the sub-Antarctic food web but depend mainly on allochthonous and autochthonous (kelp derived) organic matter, respectively.
- Full Text:
- Date Issued: 2005
Deconstructing developmental psychology twenty years on : reflections, implications and empirical work
- Callaghan, Jane, Andenæs, Agnes, Macleod, Catriona I
- Authors: Callaghan, Jane , Andenæs, Agnes , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6315 , http://hdl.handle.net/10962/d1020934 , http://journals.sagepub.com/doi/abs/10.1177/0959353515583702
- Description: Editorial
- Full Text:
- Date Issued: 2015
- Authors: Callaghan, Jane , Andenæs, Agnes , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6315 , http://hdl.handle.net/10962/d1020934 , http://journals.sagepub.com/doi/abs/10.1177/0959353515583702
- Description: Editorial
- Full Text:
- Date Issued: 2015
In search of optimal stocking regimes in semi-arid grazing lands : one size does not fit all
- Campbell, Bruce M, Gordon, Iain J, Luckert, Martin K, Petheram, Lisa, Vetter, Susan M
- Authors: Campbell, Bruce M , Gordon, Iain J , Luckert, Martin K , Petheram, Lisa , Vetter, Susan M
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6507 , http://hdl.handle.net/10962/d1005934
- Description: We discuss the search for optimal stocking regimes in semi-arid grazing lands. We argue that ‘one size does not fit all’ and that different stocking regimes are appropriate under different conditions. This paper is an attempt to move beyond polarization of the current debate towards a more integrative and flexible approach to grazing management. We propose five different conditions as major influences on grazing regimes: environmental variability and predictability; degradation and thresholds; property right regimes; discount rates; and market stability and prices. We suggest a lack of connection between the micro-economics literature and natural science and social-anthropological literature. It is timely to achieve greater integration around some key questions and hypotheses, and recognize that policy prescriptions at national or even regional levels are likely to have limited value due to context specificity.
- Full Text:
- Date Issued: 2006
- Authors: Campbell, Bruce M , Gordon, Iain J , Luckert, Martin K , Petheram, Lisa , Vetter, Susan M
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6507 , http://hdl.handle.net/10962/d1005934
- Description: We discuss the search for optimal stocking regimes in semi-arid grazing lands. We argue that ‘one size does not fit all’ and that different stocking regimes are appropriate under different conditions. This paper is an attempt to move beyond polarization of the current debate towards a more integrative and flexible approach to grazing management. We propose five different conditions as major influences on grazing regimes: environmental variability and predictability; degradation and thresholds; property right regimes; discount rates; and market stability and prices. We suggest a lack of connection between the micro-economics literature and natural science and social-anthropological literature. It is timely to achieve greater integration around some key questions and hypotheses, and recognize that policy prescriptions at national or even regional levels are likely to have limited value due to context specificity.
- Full Text:
- Date Issued: 2006
Palynology and palaeo-environment of Pleistocene hyaena coprolites from an open-air site at Oyster Bay, Eastern Cape coast, South Africa
- Carrion, J S, Brink, J S, Scott, Lucy E P, Binneman, J N F
- Authors: Carrion, J S , Brink, J S , Scott, Lucy E P , Binneman, J N F
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:7000 , http://hdl.handle.net/10962/d1008357
- Description: Hyaena coprolites in a soil horizon at Oyster Bay, Eastern Cape coast, South Africa, were found associated with abundant, early Last Glacial vertebrate faunal remains that were apparently accumulated by brown hyaenas and prehistoric humans. Artefacts of the Howieson's Poort sub-stage of the Middle Stone Age occur in the same soil. Although direct association between the different finds cannot be demonstrated, there is evidence to suggest that they are broadly contemporaneous. Pollen assemblages in the coprolites were dominated by Myrica and, to a lesser extent, Stoebe-Elytropappus type and Poaceae. Comparison with the modern pollen spectrum suggests that the past environment differed markedly from the current. The presence of Stoebe-Elytropappus, in particular, is considered to indicate a displacement of vegetation zones to lower altitudes. Both fossil pollen and fauna suggest a landscape with a complex mosaic of vegetation indicative of overall cooler, more inland conditions than today.
- Full Text: false
- Date Issued: 2000
- Authors: Carrion, J S , Brink, J S , Scott, Lucy E P , Binneman, J N F
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:7000 , http://hdl.handle.net/10962/d1008357
- Description: Hyaena coprolites in a soil horizon at Oyster Bay, Eastern Cape coast, South Africa, were found associated with abundant, early Last Glacial vertebrate faunal remains that were apparently accumulated by brown hyaenas and prehistoric humans. Artefacts of the Howieson's Poort sub-stage of the Middle Stone Age occur in the same soil. Although direct association between the different finds cannot be demonstrated, there is evidence to suggest that they are broadly contemporaneous. Pollen assemblages in the coprolites were dominated by Myrica and, to a lesser extent, Stoebe-Elytropappus type and Poaceae. Comparison with the modern pollen spectrum suggests that the past environment differed markedly from the current. The presence of Stoebe-Elytropappus, in particular, is considered to indicate a displacement of vegetation zones to lower altitudes. Both fossil pollen and fauna suggest a landscape with a complex mosaic of vegetation indicative of overall cooler, more inland conditions than today.
- Full Text: false
- Date Issued: 2000
Analytical methods for the quantitative determination of oxytocin
- Chaibva, Faith A, Walker, Roderick B
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6353 , http://hdl.handle.net/10962/d1006037
- Description: Oxytocin is a clinically important nonapeptide that is used for the induction and/or augmentation of labor and is normally administered as a slow intravenous infusion diluted with normal saline or Ringer’s lactate solution. Oxytocin is also indicated for use in the prevention and treatment of post partum hemorrhage and may be administered via either the intramuscular or intravenous routes in order to increase uterine tone and/or reduce bleeding. The analysis of oxytocin in different media has evolved over the past 30 years with the result that more sophisticated, selective and sensitive techniques are used for the determination of the compound. A variety of techniques have been applied to the determination of oxytocin in different matrices ranging from simple paper chromatography to hyphenated liquid chromatographic such as liquid chromatography coupled with mass-spectrometry. Additionally enzyme linked immuno-sorbent assays (ELISA) and radio immuno-assays (RIA) are used for the determination of low concentrations of oxytocin in biological matrices. This manuscript provides a systematic survey of the analytical methods that have been reported for isolation and quantitation of oxytocin in different matrices.
- Full Text:
- Date Issued: 2010
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:6353 , http://hdl.handle.net/10962/d1006037
- Description: Oxytocin is a clinically important nonapeptide that is used for the induction and/or augmentation of labor and is normally administered as a slow intravenous infusion diluted with normal saline or Ringer’s lactate solution. Oxytocin is also indicated for use in the prevention and treatment of post partum hemorrhage and may be administered via either the intramuscular or intravenous routes in order to increase uterine tone and/or reduce bleeding. The analysis of oxytocin in different media has evolved over the past 30 years with the result that more sophisticated, selective and sensitive techniques are used for the determination of the compound. A variety of techniques have been applied to the determination of oxytocin in different matrices ranging from simple paper chromatography to hyphenated liquid chromatographic such as liquid chromatography coupled with mass-spectrometry. Additionally enzyme linked immuno-sorbent assays (ELISA) and radio immuno-assays (RIA) are used for the determination of low concentrations of oxytocin in biological matrices. This manuscript provides a systematic survey of the analytical methods that have been reported for isolation and quantitation of oxytocin in different matrices.
- Full Text:
- Date Issued: 2010
Optimization of salbutamol sulfate dissolution from sustained release matrix formulations using an artificial neural network
- Chaibva, Faith A, Burton, Michael, Walker, Roderick B
- Authors: Chaibva, Faith A , Burton, Michael , Walker, Roderick B
- Date: 2010
- Subjects: Neural networks (Computer science)
- Language: English
- Type: Article
- Identifier: vital:6352 , http://hdl.handle.net/10962/d1006034
- Description: An artificial neural network was used to optimize the release of salbutamol sulfate from hydrophilic matrix formulations. Model formulations to be used for training, testing and validating the neural network were manufactured with the aid of a central composite design with varying the levels of Methocel® K100M, xanthan gum, Carbopol® 974P and Surelease® as the input factors. In vitro dissolution time profiles at six different sampling times were used as target data in training the neural network for formulation optimization. A multi layer perceptron with one hidden layer was constructed using Matlab®, and the number of nodes in the hidden layer was optimized by trial and error to develop a model with the best predictive ability. The results revealed that a neural network with nine nodes was optimal for developing and optimizing formulations. Simulations undertaken with the training data revealed that the constructed model was useable. The optimized neural network was used for optimization of formulation with desirable release characteristics and the results indicated that there was agreement between the predicted formulation and the manufactured formulation. This work illustrates the possible utility of artificial neural networks for the optimization of pharmaceutical formulations with desirable performance characteristics.
- Full Text:
- Date Issued: 2010
- Authors: Chaibva, Faith A , Burton, Michael , Walker, Roderick B
- Date: 2010
- Subjects: Neural networks (Computer science)
- Language: English
- Type: Article
- Identifier: vital:6352 , http://hdl.handle.net/10962/d1006034
- Description: An artificial neural network was used to optimize the release of salbutamol sulfate from hydrophilic matrix formulations. Model formulations to be used for training, testing and validating the neural network were manufactured with the aid of a central composite design with varying the levels of Methocel® K100M, xanthan gum, Carbopol® 974P and Surelease® as the input factors. In vitro dissolution time profiles at six different sampling times were used as target data in training the neural network for formulation optimization. A multi layer perceptron with one hidden layer was constructed using Matlab®, and the number of nodes in the hidden layer was optimized by trial and error to develop a model with the best predictive ability. The results revealed that a neural network with nine nodes was optimal for developing and optimizing formulations. Simulations undertaken with the training data revealed that the constructed model was useable. The optimized neural network was used for optimization of formulation with desirable release characteristics and the results indicated that there was agreement between the predicted formulation and the manufactured formulation. This work illustrates the possible utility of artificial neural networks for the optimization of pharmaceutical formulations with desirable performance characteristics.
- Full Text:
- Date Issued: 2010
The comparison of in vitro release methods for the evaluation of oxytocin release from Pluronic® F127 parenteral formulations
- Chaibva, Faith A, Walker, Roderick B
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6351 , http://hdl.handle.net/10962/d1006033
- Description: The objective of these studies was to develop a discriminatory in vitro release test for assessing formulation factors that may affect oxytocin (OT) release during formulation development studies of a Pluronic® F127 OT in situ gel-forming parenteral dosage form. An appropriate release assessment method should be able to discriminate between the performance of different formulation compositions (1, 2), and this was the primary criterion used for selection of an appropriate test procedure during the test method development process. ANOVA and the difference (f1) and similarity (f2)factors were used to evaluate the discriminatory behavior of different test methods that were investigated in these studies. The in vitro release tests that were investigated included the use of USP Apparatus 1, 2, and 3; a dialysis bag in USP Apparatus 2; and a membrane-less diffusion method. It was concluded that the use of USP Apparatus 3 was best able to discriminate between OT release for the different formulations tested. USP Apparatus 3 was thus considered the most suitable in vitro release test apparatus for studying formulation factors affecting OT release during the development of a parenteral dosage form prepared using Pluronic® F127.
- Full Text:
- Date Issued: 2007
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6351 , http://hdl.handle.net/10962/d1006033
- Description: The objective of these studies was to develop a discriminatory in vitro release test for assessing formulation factors that may affect oxytocin (OT) release during formulation development studies of a Pluronic® F127 OT in situ gel-forming parenteral dosage form. An appropriate release assessment method should be able to discriminate between the performance of different formulation compositions (1, 2), and this was the primary criterion used for selection of an appropriate test procedure during the test method development process. ANOVA and the difference (f1) and similarity (f2)factors were used to evaluate the discriminatory behavior of different test methods that were investigated in these studies. The in vitro release tests that were investigated included the use of USP Apparatus 1, 2, and 3; a dialysis bag in USP Apparatus 2; and a membrane-less diffusion method. It was concluded that the use of USP Apparatus 3 was best able to discriminate between OT release for the different formulations tested. USP Apparatus 3 was thus considered the most suitable in vitro release test apparatus for studying formulation factors affecting OT release during the development of a parenteral dosage form prepared using Pluronic® F127.
- Full Text:
- Date Issued: 2007
Development and validation of a stability-indicating analytical method for the quantitation of oxytocin in pharmaceutical dosage forms
- Chaibva, Faith A, Walker, Roderick B
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6349 , http://hdl.handle.net/10962/d1006030
- Description: A single stability-indicating assay for oxytocin (OT) in pharmaceutical dosage forms using gradient elution over 21 min has been reported in the literature. Furthermore, published and compendial methods for the analysis of OT containing dosage forms also involve using HPLC with gradient elution and complicated mobile phases that include hydrophobic ion pairing agents. A simple isocratic and stability-indicating assay was developed and validated. The conditions are as follows, column: Phenomenex® C18 Hypersil, 5 μm packing, 4.6 mm × 150 mm with acetonitrile–phosphate buffer (pH 5; 0.08 M) (20:80) as the mobile phase with UV detection at 220 nm The method was found to be specific for OT in the presence of degradation products and chlorbutol (preservative) with an overall analytical run time of 16 min. Accuracy was determined to be 0.77–1.18% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22–1.04%R.S.D. while the inter-day precision (intermediate precision) was found to be 1.27–1.68%R.S.D. for the samples studied. The calibration curve was found to be linear with the equation y = 1.81x + 0.02 and a linear regression coefficient of 0.9991 over the range 0.4–12.0 IU/ml. The LOD and the LOQ were determined to be 0.1 and 0.4 IU/ml, respectively. Syntocinon®, a commercially available dosage form of OT was assayed resulting in 100.5–106.6% recovery of the label claim and an average of 10.04 IU/ml.
- Full Text:
- Date Issued: 2006
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6349 , http://hdl.handle.net/10962/d1006030
- Description: A single stability-indicating assay for oxytocin (OT) in pharmaceutical dosage forms using gradient elution over 21 min has been reported in the literature. Furthermore, published and compendial methods for the analysis of OT containing dosage forms also involve using HPLC with gradient elution and complicated mobile phases that include hydrophobic ion pairing agents. A simple isocratic and stability-indicating assay was developed and validated. The conditions are as follows, column: Phenomenex® C18 Hypersil, 5 μm packing, 4.6 mm × 150 mm with acetonitrile–phosphate buffer (pH 5; 0.08 M) (20:80) as the mobile phase with UV detection at 220 nm The method was found to be specific for OT in the presence of degradation products and chlorbutol (preservative) with an overall analytical run time of 16 min. Accuracy was determined to be 0.77–1.18% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22–1.04%R.S.D. while the inter-day precision (intermediate precision) was found to be 1.27–1.68%R.S.D. for the samples studied. The calibration curve was found to be linear with the equation y = 1.81x + 0.02 and a linear regression coefficient of 0.9991 over the range 0.4–12.0 IU/ml. The LOD and the LOQ were determined to be 0.1 and 0.4 IU/ml, respectively. Syntocinon®, a commercially available dosage form of OT was assayed resulting in 100.5–106.6% recovery of the label claim and an average of 10.04 IU/ml.
- Full Text:
- Date Issued: 2006
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Chakona, Albert, Swartz, E R
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Date Issued: 2012
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Date Issued: 2012
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Chakona, Albert, Swartz, E R
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6777 , http://hdl.handle.net/10962/d1008087
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Date Issued: 2012
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6777 , http://hdl.handle.net/10962/d1008087
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Date Issued: 2012
The veldt sound
- Authors: Chapman, Rod , Weaser, Garry
- Subjects: McGregor, Chris--1936-1990 , Jazz , Jazz musicians , Brotherhood of Breath (Musical group)
- Language: English
- Type: Article
- Identifier: vital:13512 , http://hdl.handle.net/10962/d1006089 , McGregor, Chris--1936-1990 , Jazz , Jazz musicians , Brotherhood of Breath (Musical group)
- Description: Photocopied article from the English newspaper The Guardian about a European tour by Chris McGregor's Brotherhood of Breath. The tour starts with a concert at the Camden Jazz Festival. There is a photo of Chris McGregor playing the piano with this article.
- Full Text:
- Authors: Chapman, Rod , Weaser, Garry
- Subjects: McGregor, Chris--1936-1990 , Jazz , Jazz musicians , Brotherhood of Breath (Musical group)
- Language: English
- Type: Article
- Identifier: vital:13512 , http://hdl.handle.net/10962/d1006089 , McGregor, Chris--1936-1990 , Jazz , Jazz musicians , Brotherhood of Breath (Musical group)
- Description: Photocopied article from the English newspaper The Guardian about a European tour by Chris McGregor's Brotherhood of Breath. The tour starts with a concert at the Camden Jazz Festival. There is a photo of Chris McGregor playing the piano with this article.
- Full Text:
Replication of maximal work output levels in able-bodied workers and candidates for disability assessments: benchmark data and guidelines
- Charteris, J, James, Jonathan P
- Authors: Charteris, J , James, Jonathan P
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6752 , http://hdl.handle.net/10962/d1009332
- Description: [From the introduction]: Injured-at-work employees, when the impairments are musculo-skeletal, and the injury beyond dispute, may be faced with formal rehabilitation or informal recuperation, sometimes preceded by surgical intervention, or they may be exposed to a process of application for compensation, part of which may involve medico-legal assessments. Questions that need to be addressed somewhere in this process will determine whether the impairment is of short duration, chronic or irreparable, and will involve determination also of the severity of the impairment and the issue of the workers’ capacity to return to the former occupation versus the need to find a new employment niche commensurate with the disabled workers’ capabilities. Inevitably in this process, if it is formal, someone will need to assess the musculoskeletal strength of the injured employee and make pronouncements as to physical capacity and work-readiness. In the absence of clinical ergonomists in South Africa this task falls to a variety of professionals, some well and others poorly trained to make these determinations. Most often the assessments of work-readiness are crude, amounting to little more than unsubstantiable value judgements of supervisors or health professionals not well versed in human performance capabilities. Increasingly however, better qualified professionals are making themselves available to meet the growing demands of a more employee-centred working ethos in this country. This paper is targeted at those medical, paramedical and ergonomics professionals who already have the facilities and the expertise to make use of the technique outlined herein, to further enhance their already sound means of job-related disability assessment.
- Full Text:
- Date Issued: 2000
- Authors: Charteris, J , James, Jonathan P
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6752 , http://hdl.handle.net/10962/d1009332
- Description: [From the introduction]: Injured-at-work employees, when the impairments are musculo-skeletal, and the injury beyond dispute, may be faced with formal rehabilitation or informal recuperation, sometimes preceded by surgical intervention, or they may be exposed to a process of application for compensation, part of which may involve medico-legal assessments. Questions that need to be addressed somewhere in this process will determine whether the impairment is of short duration, chronic or irreparable, and will involve determination also of the severity of the impairment and the issue of the workers’ capacity to return to the former occupation versus the need to find a new employment niche commensurate with the disabled workers’ capabilities. Inevitably in this process, if it is formal, someone will need to assess the musculoskeletal strength of the injured employee and make pronouncements as to physical capacity and work-readiness. In the absence of clinical ergonomists in South Africa this task falls to a variety of professionals, some well and others poorly trained to make these determinations. Most often the assessments of work-readiness are crude, amounting to little more than unsubstantiable value judgements of supervisors or health professionals not well versed in human performance capabilities. Increasingly however, better qualified professionals are making themselves available to meet the growing demands of a more employee-centred working ethos in this country. This paper is targeted at those medical, paramedical and ergonomics professionals who already have the facilities and the expertise to make use of the technique outlined herein, to further enhance their already sound means of job-related disability assessment.
- Full Text:
- Date Issued: 2000
Load stress; carrier strain: implications for military and receational backpacking
- Authors: Charteris, J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6754 , http://hdl.handle.net/10962/d1009456
- Description: This paper reviews a growing literature on the stress of backpacking, particularly in military situations. Conceptual issues are raised and the implications for recreational backpackers are addressed. Under moderate to fairly heavy loading the energy cost, per kg total load carried, per hour, relates almost linearly to walking speed. Empirical data from studies in this unit are presented as benchmark indicators for use by recreational backpackers.
- Full Text:
- Date Issued: 2007
- Authors: Charteris, J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6754 , http://hdl.handle.net/10962/d1009456
- Description: This paper reviews a growing literature on the stress of backpacking, particularly in military situations. Conceptual issues are raised and the implications for recreational backpackers are addressed. Under moderate to fairly heavy loading the energy cost, per kg total load carried, per hour, relates almost linearly to walking speed. Empirical data from studies in this unit are presented as benchmark indicators for use by recreational backpackers.
- Full Text:
- Date Issued: 2007
Chris McGregor Notes
- Chauvat, Alain, Renaud, Philippe
- Authors: Chauvat, Alain , Renaud, Philippe
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Country Cooking , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Language: French
- Type: Article
- Identifier: vital:13513 , http://hdl.handle.net/10962/d1006090 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Country Cooking , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Description: Original copy of the French revue Notes. It's a long interview of Chris McGregor. On the front page there is a picture of Chris McGregor, on page 3 there is a picture of Chris McGregor playing piano, on a page 4 there is a picture of Chris McGregor bowing on stage and on page 5 there is a photo of Chris McGregor standing next to the organizer of the Nantes music festival.
- Full Text:
- Authors: Chauvat, Alain , Renaud, Philippe
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Country Cooking , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Language: French
- Type: Article
- Identifier: vital:13513 , http://hdl.handle.net/10962/d1006090 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Country Cooking , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Description: Original copy of the French revue Notes. It's a long interview of Chris McGregor. On the front page there is a picture of Chris McGregor, on page 3 there is a picture of Chris McGregor playing piano, on a page 4 there is a picture of Chris McGregor bowing on stage and on page 5 there is a photo of Chris McGregor standing next to the organizer of the Nantes music festival.
- Full Text:
Interview Chris McGregor
- Chauvat, Alain, Renaud, Philippe, Gignoux, Dany
- Authors: Chauvat, Alain , Renaud, Philippe , Gignoux, Dany
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Language: French
- Type: Article
- Identifier: vital:13514 , http://hdl.handle.net/10962/d1006091 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Description: Photocopied interview of Chris McGregor. There are 2 pictures with this article. On the first page there is a photo of the Brotherhood of Breath rehearsing and on the second page a picture of Chris McGregor playing the piano.
- Full Text:
- Authors: Chauvat, Alain , Renaud, Philippe , Gignoux, Dany
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Language: French
- Type: Article
- Identifier: vital:13514 , http://hdl.handle.net/10962/d1006091 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Jazz , Jazz musicians
- Description: Photocopied interview of Chris McGregor. There are 2 pictures with this article. On the first page there is a photo of the Brotherhood of Breath rehearsing and on the second page a picture of Chris McGregor playing the piano.
- Full Text:
Sperm morphology in four species of African platypleurine cicadas (Hemiptera: Cicadomorpha: Cicadidae)
- Chawanji, A S, Hodgson, Alan N, Villet, Martin H
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6917 , http://hdl.handle.net/10962/d1011880
- Description: Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.
- Full Text:
- Date Issued: 2005
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6917 , http://hdl.handle.net/10962/d1011880
- Description: Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.
- Full Text:
- Date Issued: 2005