A preliminary survey of the estuaries on the south coast of South Africa, Robberg Peninsula - Cape St Francis, with particular reference to the fish fauna : ecological overview article
- James, Nicola Caroline, Harrison, T D
- Authors: James, Nicola Caroline , Harrison, T D
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7144 , http://hdl.handle.net/10962/d1011842
- Description: A basic ichthyofaunal and physico-chemical survey of the coastal outlets on the south coast of South Africa (Robberg Peninsula to Cape St Francis) was undertaken during November 1994 and September 1995. Some 27 systems were identified along this stretch of coast and of these, 48% (Brak, Helpmekaars, Klip, Witels, Geelhoutbos, Kleinbos, Bruglaagte, Langbos, Sanddrif, Eerste, Boskloof, Kaapsedrif and Klipdrif [Wes]) comprised the inlets of coastal streams that offer little habitat for fishes, 26% (Sout, Bloukrans, Lottering, Elandsbos, Storms, Elands and Groot [Oos]) are located within deeply incised valleys within the Tsitsikamma region and provide limited littoral habitat for estuary-associated fishes; 26% of the systems (Piesang, Keurbooms, Matjies, Groot [Wes], Tsitsikamma, Klipdrif [Oos], Slang) appear to serve some estuarine function for both marine migrant and resident species although some of these may also be limited due to their small size and infrequent connection with the sea. This study serves to emphasize the ecological importance of these latter estuaries within this coastal sector.
- Full Text:
- Date Issued: 2009
- Authors: James, Nicola Caroline , Harrison, T D
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7144 , http://hdl.handle.net/10962/d1011842
- Description: A basic ichthyofaunal and physico-chemical survey of the coastal outlets on the south coast of South Africa (Robberg Peninsula to Cape St Francis) was undertaken during November 1994 and September 1995. Some 27 systems were identified along this stretch of coast and of these, 48% (Brak, Helpmekaars, Klip, Witels, Geelhoutbos, Kleinbos, Bruglaagte, Langbos, Sanddrif, Eerste, Boskloof, Kaapsedrif and Klipdrif [Wes]) comprised the inlets of coastal streams that offer little habitat for fishes, 26% (Sout, Bloukrans, Lottering, Elandsbos, Storms, Elands and Groot [Oos]) are located within deeply incised valleys within the Tsitsikamma region and provide limited littoral habitat for estuary-associated fishes; 26% of the systems (Piesang, Keurbooms, Matjies, Groot [Wes], Tsitsikamma, Klipdrif [Oos], Slang) appear to serve some estuarine function for both marine migrant and resident species although some of these may also be limited due to their small size and infrequent connection with the sea. This study serves to emphasize the ecological importance of these latter estuaries within this coastal sector.
- Full Text:
- Date Issued: 2009
Disjunctions in the Diptera (Insecta) fauna of the Mediterranean Province and southern Africa and a discussion of biogeographical considerations : ecological overview article
- Kirk-Spriggs, A H, McGregor, Gillian K
- Authors: Kirk-Spriggs, A H , McGregor, Gillian K
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6880 , http://hdl.handle.net/10962/d1011636
- Description: This paper explores disjunctions in the Diptera fauna of the Mediterranean Province and southern Africa, drawing from eight families of Diptera, the more ancient Psychodidae and Vermileonidae, and the more recent Acroceridae, Asilidae, Bombyliidae, Dolichopodidae, Pipunculidae and Sciomyzidae. Information from recent published revisions is geo-referenced and plotted onto maps using GIS software. These distribution patterns are interpreted and probable means and routes of dispersal between the two regions are discussed. The concept of an Afrotropical sub-Saharan boundary is outlined and it is argued that although the vast, arid and virtually abiotic Sahara acts as a barrier to dispersal today, relict floral and faunal populations of Mediterranean provincial origin still occur on the Hoggar and Tibesti Mountains of the central Sahara, indicating that the aridification of the Sahara is a very recent event. The presence of extensive palaeolakes formerly covering ca 10% of the present-day Sahara is regarded as evidence in support of this hypothesis. These lakes and their associated catchments, situated in basins between the central Saharan mountains, could clearly have acted as a humid route of dispersal as recently as 4000 BP, when these lakes began to recede, and this route is here regarded as a "central high Africa corridor"; a filter-bridge between the Mediterranean Province and southern Africa. Examples of Mediterranean provincial species of Ephydridae and the muscid genus Lispe Latreille, 1796, occurring as far south as the AÏr Massif in northern Niger are cited as examples of relict montane Diptera of Mediterranean provincial origin in the southern Hoggar Mountains; these groups being associated with the margins of standing water. Balinsky's (1962) concept of an "arid corridor" is also re-examined, using examples from the larger, less mobile Diptera, and it is concluded that such a pattern may not be the result of aridity, but represent an "eastern high Africa corridor", broadly corresponding to the "African Supers well". Other perceived distribution pathways between the Holarctic and Afrotropical Regions are mapped. Anemochore dispersal is considered, and the extent of the Afrotropical Region is discussed. Mediterranean tectonic evolution on both a globe of constant size and on a smaller Jurassic globe is also considered. It is concluded that if all the transitional zones between the zoogeographical regions are to be given more-or-less equivalent treatment, we must avoid setting boundaries based on earlier faunal distributions. For this reason the current boundary between the Palaearctic and Afrotropical Regions, arbitrary as it is, should be retained, despite evidence suggesting recent continuity between sub-Saharan Africa, North Africa and the Arabian Peninsula, corresponding broadly to the African and Arabian lithospheric plates.
- Full Text:
- Date Issued: 2009
- Authors: Kirk-Spriggs, A H , McGregor, Gillian K
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6880 , http://hdl.handle.net/10962/d1011636
- Description: This paper explores disjunctions in the Diptera fauna of the Mediterranean Province and southern Africa, drawing from eight families of Diptera, the more ancient Psychodidae and Vermileonidae, and the more recent Acroceridae, Asilidae, Bombyliidae, Dolichopodidae, Pipunculidae and Sciomyzidae. Information from recent published revisions is geo-referenced and plotted onto maps using GIS software. These distribution patterns are interpreted and probable means and routes of dispersal between the two regions are discussed. The concept of an Afrotropical sub-Saharan boundary is outlined and it is argued that although the vast, arid and virtually abiotic Sahara acts as a barrier to dispersal today, relict floral and faunal populations of Mediterranean provincial origin still occur on the Hoggar and Tibesti Mountains of the central Sahara, indicating that the aridification of the Sahara is a very recent event. The presence of extensive palaeolakes formerly covering ca 10% of the present-day Sahara is regarded as evidence in support of this hypothesis. These lakes and their associated catchments, situated in basins between the central Saharan mountains, could clearly have acted as a humid route of dispersal as recently as 4000 BP, when these lakes began to recede, and this route is here regarded as a "central high Africa corridor"; a filter-bridge between the Mediterranean Province and southern Africa. Examples of Mediterranean provincial species of Ephydridae and the muscid genus Lispe Latreille, 1796, occurring as far south as the AÏr Massif in northern Niger are cited as examples of relict montane Diptera of Mediterranean provincial origin in the southern Hoggar Mountains; these groups being associated with the margins of standing water. Balinsky's (1962) concept of an "arid corridor" is also re-examined, using examples from the larger, less mobile Diptera, and it is concluded that such a pattern may not be the result of aridity, but represent an "eastern high Africa corridor", broadly corresponding to the "African Supers well". Other perceived distribution pathways between the Holarctic and Afrotropical Regions are mapped. Anemochore dispersal is considered, and the extent of the Afrotropical Region is discussed. Mediterranean tectonic evolution on both a globe of constant size and on a smaller Jurassic globe is also considered. It is concluded that if all the transitional zones between the zoogeographical regions are to be given more-or-less equivalent treatment, we must avoid setting boundaries based on earlier faunal distributions. For this reason the current boundary between the Palaearctic and Afrotropical Regions, arbitrary as it is, should be retained, despite evidence suggesting recent continuity between sub-Saharan Africa, North Africa and the Arabian Peninsula, corresponding broadly to the African and Arabian lithospheric plates.
- Full Text:
- Date Issued: 2009
A common framework for lattice-valued uniform spaces and probabilistic uniform limit spaces
- Craig, Andrew, Jäger, Gunter
- Authors: Craig, Andrew , Jäger, Gunter
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6784 , http://hdl.handle.net/10962/d1006927
- Description: We study a category of lattice-valued uniform convergence spaces where the lattice is enriched by two algebraic operations. This general setting allows us to view the category of lattice-valued uniform spaces as a reflective subcategory of our category, and the category of probabilistic uniform limit spaces as a coreflective subcategory.
- Full Text:
- Date Issued: 2009
- Authors: Craig, Andrew , Jäger, Gunter
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6784 , http://hdl.handle.net/10962/d1006927
- Description: We study a category of lattice-valued uniform convergence spaces where the lattice is enriched by two algebraic operations. This general setting allows us to view the category of lattice-valued uniform spaces as a reflective subcategory of our category, and the category of probabilistic uniform limit spaces as a coreflective subcategory.
- Full Text:
- Date Issued: 2009
The TPR2B domain of the Hsp70/Hsp90 organizing protein (Hop) may contribute towards its dimerization
- Longshaw, Victoria M, Stephens, Linda L, Daniel, Sheril, Blatch, Gregory L
- Authors: Longshaw, Victoria M , Stephens, Linda L , Daniel, Sheril , Blatch, Gregory L
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6481 , http://hdl.handle.net/10962/d1006253 , http://dx.doi.org/10.2174/092986609787848162
- Description: The role of the TPR2B domain of Hop is as yet unknown. We have shown here by site directed mutagenesis and size exclusion chromatography for the first time that the TPR1 and TPR2B domains of Hop independently dimerized, and that the dimerization of TPR2B was not dependent on its predicted two-carboxylate clamp residues. Furthermore, our data indicated that the dimerization of Hop and its domains was not disrupted in the presence of Hsp70 and Hsp90 peptides.
- Full Text:
- Date Issued: 2009
The TPR2B domain of the Hsp70/Hsp90 organizing protein (Hop) may contribute towards its dimerization
- Authors: Longshaw, Victoria M , Stephens, Linda L , Daniel, Sheril , Blatch, Gregory L
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6481 , http://hdl.handle.net/10962/d1006253 , http://dx.doi.org/10.2174/092986609787848162
- Description: The role of the TPR2B domain of Hop is as yet unknown. We have shown here by site directed mutagenesis and size exclusion chromatography for the first time that the TPR1 and TPR2B domains of Hop independently dimerized, and that the dimerization of TPR2B was not dependent on its predicted two-carboxylate clamp residues. Furthermore, our data indicated that the dimerization of Hop and its domains was not disrupted in the presence of Hsp70 and Hsp90 peptides.
- Full Text:
- Date Issued: 2009
Municipal commonage policy and livestock owners : findings from the Eastern Cape, South Africa
- Davenport, Nicholas A, Gambiza, James
- Authors: Davenport, Nicholas A , Gambiza, James
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6628 , http://hdl.handle.net/10962/d1006820
- Description: The new African National Congress government announced after 1994 that municipal commonage would be a pillar of their land reform programme. The Department of Land Affairs spearheaded this by acquiring new land to complement the existing ‘old’ commonages. The aim of old commonage was to supplement the income of poor urban residents through the subsistence user system whereas new commonage was intended as a ‘stepping stone’ for emergent farmers. We investigated the differences between old and new commonage farmers as well as how they perceived the Makana local municipality's capacity to manage the commonage. The results showed that local institutions were weak. Only 46% of the old commonage farmers were members of a local livestock association whereas 74% of the new commonage farmers were members. Most old commonage farmers (59%) were dissatisfied with local government's management of the commonage. In contrast, only 37% of the new commonage farmers were dissatisfied with the management of the commonage. There were no differences between old and new commonage farmers in terms of livestock owners’ characteristics and mean annual net direct-use value of livestock. There were also no differences in the age of the two types of commonage farmers. Furthermore, there was no association between the type of commonage and level of education. The mean annual net direct-use value of livestock on old commonage was R6308 compared with R9707 on new commonage. Although the income from livestock for new commonage farmers varied slightly from that of old commonage farmers, the annual productive output per farmer on old commonage was R473 ha−1, three times higher than that of new commonage farmers which was R134 ha−1. We suggest that new land policy legislation is needed in which poverty as well as the legal arrangements between all stakeholders is clearly defined. Furthermore, national departments need to be more involved with local municipalities to increase local management capacity.
- Full Text:
- Date Issued: 2009
- Authors: Davenport, Nicholas A , Gambiza, James
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6628 , http://hdl.handle.net/10962/d1006820
- Description: The new African National Congress government announced after 1994 that municipal commonage would be a pillar of their land reform programme. The Department of Land Affairs spearheaded this by acquiring new land to complement the existing ‘old’ commonages. The aim of old commonage was to supplement the income of poor urban residents through the subsistence user system whereas new commonage was intended as a ‘stepping stone’ for emergent farmers. We investigated the differences between old and new commonage farmers as well as how they perceived the Makana local municipality's capacity to manage the commonage. The results showed that local institutions were weak. Only 46% of the old commonage farmers were members of a local livestock association whereas 74% of the new commonage farmers were members. Most old commonage farmers (59%) were dissatisfied with local government's management of the commonage. In contrast, only 37% of the new commonage farmers were dissatisfied with the management of the commonage. There were no differences between old and new commonage farmers in terms of livestock owners’ characteristics and mean annual net direct-use value of livestock. There were also no differences in the age of the two types of commonage farmers. Furthermore, there was no association between the type of commonage and level of education. The mean annual net direct-use value of livestock on old commonage was R6308 compared with R9707 on new commonage. Although the income from livestock for new commonage farmers varied slightly from that of old commonage farmers, the annual productive output per farmer on old commonage was R473 ha−1, three times higher than that of new commonage farmers which was R134 ha−1. We suggest that new land policy legislation is needed in which poverty as well as the legal arrangements between all stakeholders is clearly defined. Furthermore, national departments need to be more involved with local municipalities to increase local management capacity.
- Full Text:
- Date Issued: 2009
'Here's to you, Mrs Robinson' : peculiarities and paragraph 29 in determining the treatment of domestic partnerships
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: vital:26388 , http://hdl.handle.net/10962/54083
- Description: There is always need of persons not only to discover new truths, and point out when what were once truths are true no longer, but also to commence new practices, and set the example of more enlightened conduct. The law is one of the important architects of social norms. At times, it can be a tool to solve problems, eradicate inequalities, and advance the rights of the disadvantaged. At other times, the law is an anchor and a constraint upon social and ideological advances. With regards to equality and non-traditional partnerships, it seems that law falls into this latter category.
- Full Text:
- Date Issued: 2009
- Authors: Kruuse, Helen
- Date: 2009
- Language: English
- Type: Article , text
- Identifier: vital:26388 , http://hdl.handle.net/10962/54083
- Description: There is always need of persons not only to discover new truths, and point out when what were once truths are true no longer, but also to commence new practices, and set the example of more enlightened conduct. The law is one of the important architects of social norms. At times, it can be a tool to solve problems, eradicate inequalities, and advance the rights of the disadvantaged. At other times, the law is an anchor and a constraint upon social and ideological advances. With regards to equality and non-traditional partnerships, it seems that law falls into this latter category.
- Full Text:
- Date Issued: 2009
We are all the public
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6198 , http://hdl.handle.net/10962/d1008562
- Description: [from introduction]: Across the country the most vulnerable people in our society are being subject to brazenly unlawful and often violent action at the hands of the state. Homeless people, refugees, sex workers, street traders and shack dwellers are all being taught, in the most literal sense of the term, to know their place. But state illegality is not only aimed at the segregation of physical space. It is also about ensuring that the people on the margins of society know their political place.
- Full Text:
- Date Issued: 2009
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6198 , http://hdl.handle.net/10962/d1008562
- Description: [from introduction]: Across the country the most vulnerable people in our society are being subject to brazenly unlawful and often violent action at the hands of the state. Homeless people, refugees, sex workers, street traders and shack dwellers are all being taught, in the most literal sense of the term, to know their place. But state illegality is not only aimed at the segregation of physical space. It is also about ensuring that the people on the margins of society know their political place.
- Full Text:
- Date Issued: 2009
Rapid UPLC - MS/MS method for the determination of ketoprofen in human dermal microdialysis samples
- Tettey-Amlalo, Ralph N O, Kanfer, Isadore
- Authors: Tettey-Amlalo, Ralph N O , Kanfer, Isadore
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6444 , http://hdl.handle.net/10962/d1006631
- Description: Dermal microdialysis (DMD) is a technique capable of determining the percutaneous penetration of drugs from topical formulations intended for local and/or regional activity. Typically, the concentrations of drug collected in dialysates are very low, generally in the ng/ml or even pg/ml range. An additional challenge is the very low volume of sample collected at each collection time and which can range from 1 to 30 μl only. Hence the objective was to develop and validate a rapid, accurate, precise, reproducible and highly sensitive LC–MS/MS method for the quantitative analysis of ketoprofen (KET) in dialystes following application of a topical gel product to the skin of human subjects. UPLC–MS/MS was used and KET was separated on an Acquity™ UPLC BEH C18 column (100 mm × 2.1 mm i.d., 1.7 μm) and analysed in negative-ion (NI) electrospray ionisation (ESI) mode. The mobile phase (MP) consisted of acetonitrile:methanol:water (60:20:20, v/v/v) under isocratic conditions at a flow rate of 0.3 ml/min. Samples were extracted using ethyl acetate with ibuprofen (IBU) as internal standard (IS) and the organic solvent was then evaporated to dryness and the residue re-constituted in methanol. 5 μl samples were injected and analysis was performed at ambient temperature 22 ± 0.5 °C. KET and IBU eluted at 1.07 and 1.49 min, respectively. KET and IBU responses were optimised at the transitions 253.00 > 209.00 and 205.00 > 161.00, respectively. Calibration curves were linear over the range 0.5–500 ng/ml with correlation coefficients > 0.999. The accuracy and precision of the method were found to be between 99.97% and 104.67% (R.S.D. < 2%) and the mean recovery of KET from normal saline was 88.03 ± 0.3% (R.S.D. < 2.20%). The LLOQ and LOD values were found to be 0.5 and 0.1 ng/ml respectively whereas the ULOD was set at 500 ng/ml. The method was successfully applied to determine the bioavailability of KET following application of topical KET gel, Fastum® gel, to the skin of human volunteers.
- Full Text:
- Date Issued: 2009
- Authors: Tettey-Amlalo, Ralph N O , Kanfer, Isadore
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6444 , http://hdl.handle.net/10962/d1006631
- Description: Dermal microdialysis (DMD) is a technique capable of determining the percutaneous penetration of drugs from topical formulations intended for local and/or regional activity. Typically, the concentrations of drug collected in dialysates are very low, generally in the ng/ml or even pg/ml range. An additional challenge is the very low volume of sample collected at each collection time and which can range from 1 to 30 μl only. Hence the objective was to develop and validate a rapid, accurate, precise, reproducible and highly sensitive LC–MS/MS method for the quantitative analysis of ketoprofen (KET) in dialystes following application of a topical gel product to the skin of human subjects. UPLC–MS/MS was used and KET was separated on an Acquity™ UPLC BEH C18 column (100 mm × 2.1 mm i.d., 1.7 μm) and analysed in negative-ion (NI) electrospray ionisation (ESI) mode. The mobile phase (MP) consisted of acetonitrile:methanol:water (60:20:20, v/v/v) under isocratic conditions at a flow rate of 0.3 ml/min. Samples were extracted using ethyl acetate with ibuprofen (IBU) as internal standard (IS) and the organic solvent was then evaporated to dryness and the residue re-constituted in methanol. 5 μl samples were injected and analysis was performed at ambient temperature 22 ± 0.5 °C. KET and IBU eluted at 1.07 and 1.49 min, respectively. KET and IBU responses were optimised at the transitions 253.00 > 209.00 and 205.00 > 161.00, respectively. Calibration curves were linear over the range 0.5–500 ng/ml with correlation coefficients > 0.999. The accuracy and precision of the method were found to be between 99.97% and 104.67% (R.S.D. < 2%) and the mean recovery of KET from normal saline was 88.03 ± 0.3% (R.S.D. < 2.20%). The LLOQ and LOD values were found to be 0.5 and 0.1 ng/ml respectively whereas the ULOD was set at 500 ng/ml. The method was successfully applied to determine the bioavailability of KET following application of topical KET gel, Fastum® gel, to the skin of human volunteers.
- Full Text:
- Date Issued: 2009
Synthesis, spectroscopic and electrochemical properties of manganese, nickel and iron octakis-(2-diethylaminoethanethiol)-phthalocyanine
- Adebayo, A I, Nyokong, Tebello
- Authors: Adebayo, A I , Nyokong, Tebello
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6563 , http://hdl.handle.net/10962/d1004122
- Description: The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported. Complex 3 showed two reversible reduction couples attributed to the MnIIIPc−2/MnIIPc−2 (E½ = −0.12 V versus Ag|AgCl) and MnIIPc−2/MnIIPc−3 (E½ = −0.82 V versus Ag|AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the FeIIPc−2/FeIPc−2 (E½ = −0.35 V versus Ag|AgCl) and FeIPc−2/FeIPc−3 (E½ = −0.96 V versus Ag|AgCl) species, and an oxidation couple, attributed to FeIIIPc−2/FeIIPc−2 (E½ = 0.26 V versus Ag|AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to −1.8 V versus Ag|AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes.
- Full Text:
- Date Issued: 2009
- Authors: Adebayo, A I , Nyokong, Tebello
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6563 , http://hdl.handle.net/10962/d1004122
- Description: The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported. Complex 3 showed two reversible reduction couples attributed to the MnIIIPc−2/MnIIPc−2 (E½ = −0.12 V versus Ag|AgCl) and MnIIPc−2/MnIIPc−3 (E½ = −0.82 V versus Ag|AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the FeIIPc−2/FeIPc−2 (E½ = −0.35 V versus Ag|AgCl) and FeIPc−2/FeIPc−3 (E½ = −0.96 V versus Ag|AgCl) species, and an oxidation couple, attributed to FeIIIPc−2/FeIIPc−2 (E½ = 0.26 V versus Ag|AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to −1.8 V versus Ag|AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes.
- Full Text:
- Date Issued: 2009
Professor Emeritus Denis William Ewer MBE FRSSAf 1913 - 2009: biographical memoir
- Authors: Hodgson, Alan N
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6884 , http://hdl.handle.net/10962/d1011643
- Description: Denis Ewer went to University College School in London. In 1931 he entered Trinity College, Cambridge (his father had studied mathematics at Trinity) where he read for the Natural Science Tripos, obtaining a B.A. in 1934. In his second year at Cambridge he gained the nickname of 'Jakes' via a literary route (his father's nickname also had literary origins). The word 'ewer' can mean a jug, chamber pot, or jerry, and hence the progress to 'jakes', Elizabethan English for an outside lavatory. It was at Cambridge that he also met the future communist spy, Kim Philby. After graduating, Jakes Ewer moved to the University of Birmingham where he undertook his doctoral studies (graduating PhD in 1940) under H. Munro Fox. World War II, however, temporarily halted any further academic career, and during the war years he was an Experimental Officer for the Army Operational Research Group (Ministry of Supply) achieving the rank of Major. For his work, which included being a Scientific Advisor to the Chief, Air Defence Division, Supreme Headquarters Allied Expeditionary Force, he was awarded the M.B.E. (Member of the British Empire).
- Full Text:
- Date Issued: 2006
- Authors: Hodgson, Alan N
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6884 , http://hdl.handle.net/10962/d1011643
- Description: Denis Ewer went to University College School in London. In 1931 he entered Trinity College, Cambridge (his father had studied mathematics at Trinity) where he read for the Natural Science Tripos, obtaining a B.A. in 1934. In his second year at Cambridge he gained the nickname of 'Jakes' via a literary route (his father's nickname also had literary origins). The word 'ewer' can mean a jug, chamber pot, or jerry, and hence the progress to 'jakes', Elizabethan English for an outside lavatory. It was at Cambridge that he also met the future communist spy, Kim Philby. After graduating, Jakes Ewer moved to the University of Birmingham where he undertook his doctoral studies (graduating PhD in 1940) under H. Munro Fox. World War II, however, temporarily halted any further academic career, and during the war years he was an Experimental Officer for the Army Operational Research Group (Ministry of Supply) achieving the rank of Major. For his work, which included being a Scientific Advisor to the Chief, Air Defence Division, Supreme Headquarters Allied Expeditionary Force, he was awarded the M.B.E. (Member of the British Empire).
- Full Text:
- Date Issued: 2006
Seeing is natural, but viewing is not: teaching visual literacy in a rural classroom
- Mbelani, Madeyandile, Murray, Sarah R
- Authors: Mbelani, Madeyandile , Murray, Sarah R
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7022 , http://hdl.handle.net/10962/d1007203
- Description: This paper reports on a collaborative action research case study into Grade 10 teaching and learning of visual literacy in a rural high school into the Eastern Cape, South Africa. Visual literacy is a new aspect that has been incorporated in English First Additional Language National Curriculum Statement (Grade 10-12), which has been implemented in Grade 10 from 2006. With the aim of gaining knowledge and improving performance in visual literacy, I designed a unit of lessons, which exposed learners to visual grammar and visual texts and I collected data around the implementation of the lesson unit as evidenced by journal writing, interviews and non-participant observation. The data revealed that visual literacy could be taught meaningfully in a rural high school as the learners could identify, cut, paste and critically discuss elements of visual language and they finally designed their own advertisements in groups. However, the following factors emerged as hindrances to the successful teaching of visual literacy in this case: lack of resources; learners' lack of a foundation in visual literacy from Grades 7-9; and problems revolving around time management and pacing.
- Full Text:
- Date Issued: 2009
- Authors: Mbelani, Madeyandile , Murray, Sarah R
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:7022 , http://hdl.handle.net/10962/d1007203
- Description: This paper reports on a collaborative action research case study into Grade 10 teaching and learning of visual literacy in a rural high school into the Eastern Cape, South Africa. Visual literacy is a new aspect that has been incorporated in English First Additional Language National Curriculum Statement (Grade 10-12), which has been implemented in Grade 10 from 2006. With the aim of gaining knowledge and improving performance in visual literacy, I designed a unit of lessons, which exposed learners to visual grammar and visual texts and I collected data around the implementation of the lesson unit as evidenced by journal writing, interviews and non-participant observation. The data revealed that visual literacy could be taught meaningfully in a rural high school as the learners could identify, cut, paste and critically discuss elements of visual language and they finally designed their own advertisements in groups. However, the following factors emerged as hindrances to the successful teaching of visual literacy in this case: lack of resources; learners' lack of a foundation in visual literacy from Grades 7-9; and problems revolving around time management and pacing.
- Full Text:
- Date Issued: 2009
Possible trace fossils of putative termite origin in the Lower Jurassic (Karoo Supergroup) of South Africa and Lesotho
- Bordy, Emese M, Bumby, A J, Catuneanu, O, Eriksson, P G
- Authors: Bordy, Emese M , Bumby, A J , Catuneanu, O , Eriksson, P G
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6732 , http://hdl.handle.net/10962/d1007541
- Description: Complex structures in the sandstones of the Lower Jurassic aeolian Clarens Formation (Karoo Supergroup) are found at numerous localities throughout southern Africa, and can be assigned to five distinct architectural groups: (1) up to 3.3-m high, free-standing, slab-shaped forms of bioturbated sandstones with elliptical bases, orientated buttresses and an interconnecting large burrow system; (2) up to 1.2-m high, free-standing, irregular forms of bioturbated sandstones with 2-cm to 4-cm thick, massive walls, empty chambers and vertical shafts; (3) about 0.15-m to 0.25-m high, mainly bulbous, multiple forms with thin walls (<2 cm), hollow chambers with internal pillars and bridges; (4) about 0.15-m to 0.2-m (maximum 1-m) high, free-standing forms of aggregated solitary spheres associated with massive horizontal, orientated capsules or tubes, and meniscate tubes; and (5) about 5 cmin diameter, ovoid forms with weak internal shelving in a close-fitting cavity. Based on size, wall thickness, orientation and the presence of internal chambers, these complex structures are tentatively interpreted as ichnofossils of an Early Jurassic social organism; the different architectures are reflective of the different behaviours of more than one species, the history of structural change in architectural forms (ontogenetic series) or an architectural adaptation to local palaeoclimatic variability. While exact modern equivalents are unknown, some of these ichnofossils are comparable to nests (or parts of nests) constructed by extant termites, and thus these Jurassic structures are very tentatively interpreted here as having been made by a soil-dwelling social organism, probably of termite origin. This southern African discovery, along with reported Triassic and Jurassic termite ichnofossils from North America, supports previous hypotheses that sociality in insects, particularity in termites, likely evolved prior to the Pangea breakup in the Early Mesozoic.
- Full Text:
- Date Issued: 2009
- Authors: Bordy, Emese M , Bumby, A J , Catuneanu, O , Eriksson, P G
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6732 , http://hdl.handle.net/10962/d1007541
- Description: Complex structures in the sandstones of the Lower Jurassic aeolian Clarens Formation (Karoo Supergroup) are found at numerous localities throughout southern Africa, and can be assigned to five distinct architectural groups: (1) up to 3.3-m high, free-standing, slab-shaped forms of bioturbated sandstones with elliptical bases, orientated buttresses and an interconnecting large burrow system; (2) up to 1.2-m high, free-standing, irregular forms of bioturbated sandstones with 2-cm to 4-cm thick, massive walls, empty chambers and vertical shafts; (3) about 0.15-m to 0.25-m high, mainly bulbous, multiple forms with thin walls (<2 cm), hollow chambers with internal pillars and bridges; (4) about 0.15-m to 0.2-m (maximum 1-m) high, free-standing forms of aggregated solitary spheres associated with massive horizontal, orientated capsules or tubes, and meniscate tubes; and (5) about 5 cmin diameter, ovoid forms with weak internal shelving in a close-fitting cavity. Based on size, wall thickness, orientation and the presence of internal chambers, these complex structures are tentatively interpreted as ichnofossils of an Early Jurassic social organism; the different architectures are reflective of the different behaviours of more than one species, the history of structural change in architectural forms (ontogenetic series) or an architectural adaptation to local palaeoclimatic variability. While exact modern equivalents are unknown, some of these ichnofossils are comparable to nests (or parts of nests) constructed by extant termites, and thus these Jurassic structures are very tentatively interpreted here as having been made by a soil-dwelling social organism, probably of termite origin. This southern African discovery, along with reported Triassic and Jurassic termite ichnofossils from North America, supports previous hypotheses that sociality in insects, particularity in termites, likely evolved prior to the Pangea breakup in the Early Mesozoic.
- Full Text:
- Date Issued: 2009
Recent progress in electrochemical oxidation of saccharides at gold and copper electrodes in alkaline solutions
- Torto, N
- Authors: Torto, N
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6599 , http://hdl.handle.net/10962/d1004348
- Description: This article reviews the progress made in the past 10 years, on electrochemical oxidation of saccharides in alkaline media for gold and copper electrodes. The mechanism and processes associated with the electrochemical oxidation of saccharides at native and surface coated electrodes continues to be of great interest. Despite the effort and various mechanisms proposed, still the need for an electrochemically active material that understands the complexity associated with saccharides continues to increase as their detection poses a challenge for bioanalytical chemistry and liquid chromatography.
- Full Text:
- Date Issued: 2009
- Authors: Torto, N
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6599 , http://hdl.handle.net/10962/d1004348
- Description: This article reviews the progress made in the past 10 years, on electrochemical oxidation of saccharides in alkaline media for gold and copper electrodes. The mechanism and processes associated with the electrochemical oxidation of saccharides at native and surface coated electrodes continues to be of great interest. Despite the effort and various mechanisms proposed, still the need for an electrochemically active material that understands the complexity associated with saccharides continues to increase as their detection poses a challenge for bioanalytical chemistry and liquid chromatography.
- Full Text:
- Date Issued: 2009
We need a conversation about development
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6199 , http://hdl.handle.net/10962/d1008563
- Description: [From the introduction] From the Communist Party across to the corporate spin-doctors and down to the Development Committees in the shack settlements, more or less everybody in South Africa speaks the language of development. In some ways this is a good thing. It indicates a hard won agreement that the realities of inequality in our society are so cruel and perverse that any social project can only be credible if it will ameliorate these divisions and the suffering they cause.
- Full Text:
- Date Issued: 2009
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6199 , http://hdl.handle.net/10962/d1008563
- Description: [From the introduction] From the Communist Party across to the corporate spin-doctors and down to the Development Committees in the shack settlements, more or less everybody in South Africa speaks the language of development. In some ways this is a good thing. It indicates a hard won agreement that the realities of inequality in our society are so cruel and perverse that any social project can only be credible if it will ameliorate these divisions and the suffering they cause.
- Full Text:
- Date Issued: 2009
Promoting indigenous vegetables in urban agriculture & livelihoods : policy lessons from Sub-Saharan Africa
- Shackleton, Charlie M, Pasquini, Margaret W, Ambrose-Oji, Bianca, Drescher, Axel W
- Authors: Shackleton, Charlie M , Pasquini, Margaret W , Ambrose-Oji, Bianca , Drescher, Axel W
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6619 , http://hdl.handle.net/10962/d1016227
- Description: [From Introduction] Globally, the growth of urbanised areas continues at an exponential rate, and most spectacularly in the developing world. The global urban population will increase from 2.9 billion in 2000 to 5.0 billion by 2030. The mean rate of urban growth in non-OECD countries between 2000 and 2005 was just under 3% per annum, compared to 0.5 % for rural regions of the same countries (UN-Habitat 2006). Although the proportion of Africans currently living in urban areas is the lowest in the world (+ 40%), because of this low base it is not unsurprising that the rates of urbanisation are among the highest at approximately 4.3% per annum. Projections vary, but sometime in the mid- 2020s over 50% of Africa's population will be living in urban areas, as compared to just 15% in 1950 and 34% in 1994. As urbanisation takes place another important trend is revealed, namely the locus of poverty in Africa is slowly shifting from rural to urban areas. For example, it is estimated that more than 56% of the world's absolute or chronic poor will be concentrated in urban areas (WRI 1996). Since as much as 60-80% of the income of the urban poor is spent on the purchase of food (Maxwell et al. 2000), the issue of food supply, both its quantity and quality, is increasingly a central issue in poverty reduction debates and strategies. In rural areas, a common strategy to alleviate poverty is to call for measures to boost small-holder food production. Surprisingly, this is less common in urban poverty alleviation programmes, despite the widespread promise of urban and household agriculture in contributing to improved food security.
- Full Text:
- Date Issued: 2009
- Authors: Shackleton, Charlie M , Pasquini, Margaret W , Ambrose-Oji, Bianca , Drescher, Axel W
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6619 , http://hdl.handle.net/10962/d1016227
- Description: [From Introduction] Globally, the growth of urbanised areas continues at an exponential rate, and most spectacularly in the developing world. The global urban population will increase from 2.9 billion in 2000 to 5.0 billion by 2030. The mean rate of urban growth in non-OECD countries between 2000 and 2005 was just under 3% per annum, compared to 0.5 % for rural regions of the same countries (UN-Habitat 2006). Although the proportion of Africans currently living in urban areas is the lowest in the world (+ 40%), because of this low base it is not unsurprising that the rates of urbanisation are among the highest at approximately 4.3% per annum. Projections vary, but sometime in the mid- 2020s over 50% of Africa's population will be living in urban areas, as compared to just 15% in 1950 and 34% in 1994. As urbanisation takes place another important trend is revealed, namely the locus of poverty in Africa is slowly shifting from rural to urban areas. For example, it is estimated that more than 56% of the world's absolute or chronic poor will be concentrated in urban areas (WRI 1996). Since as much as 60-80% of the income of the urban poor is spent on the purchase of food (Maxwell et al. 2000), the issue of food supply, both its quantity and quality, is increasingly a central issue in poverty reduction debates and strategies. In rural areas, a common strategy to alleviate poverty is to call for measures to boost small-holder food production. Surprisingly, this is less common in urban poverty alleviation programmes, despite the widespread promise of urban and household agriculture in contributing to improved food security.
- Full Text:
- Date Issued: 2009
Synthesis of molecularly imprinted polymer for selective solid-phase extraction of Salbutamol from urine samples
- Mohammadi, Ali, Alizadeh, Taher, Dinarvand, Rassoul, Ganjali, Mohammed M, Walker, Roderick B
- Authors: Mohammadi, Ali , Alizadeh, Taher , Dinarvand, Rassoul , Ganjali, Mohammed M , Walker, Roderick B
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6410 , http://hdl.handle.net/10962/d1006496
- Description: A highly selective methacrylic based molecularly imprinted polymer (MIP) was synthesized and applied for the separation and the pre-concentration of salbutamol in urine samples. Spectrophotometric determination of salbutamol was achieved using 2,6-dichloroquinone chlorimide as colorimetric reagent. The detection limit of the method was ca. 13 ng/mL in urine after pre-concentration of the samples by MIP-SPE andanalysis with an optimized and sensitive spectrophotometric method. The linear dynamic range for salbutamol determination in urine was 0.04-0.75 μg mL-1. The recovery for the affinity based solid-phase extraction (SPE) with the MIP was more than 96 %.
- Full Text:
- Date Issued: 2009
- Authors: Mohammadi, Ali , Alizadeh, Taher , Dinarvand, Rassoul , Ganjali, Mohammed M , Walker, Roderick B
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6410 , http://hdl.handle.net/10962/d1006496
- Description: A highly selective methacrylic based molecularly imprinted polymer (MIP) was synthesized and applied for the separation and the pre-concentration of salbutamol in urine samples. Spectrophotometric determination of salbutamol was achieved using 2,6-dichloroquinone chlorimide as colorimetric reagent. The detection limit of the method was ca. 13 ng/mL in urine after pre-concentration of the samples by MIP-SPE andanalysis with an optimized and sensitive spectrophotometric method. The linear dynamic range for salbutamol determination in urine was 0.04-0.75 μg mL-1. The recovery for the affinity based solid-phase extraction (SPE) with the MIP was more than 96 %.
- Full Text:
- Date Issued: 2009
The KwaZulu-Natal Slums Act: bloody legislation against the expropriated
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6201 , http://hdl.handle.net/10962/d1008568
- Description: [From introduction]: On 14 May 2009 the Constitutional Court will hear the attempt by the shack dweller’s movement Abahlali baseMjondolo to have the KwaZulu-Natal Slums Act declared unlawful. Other provinces have been mandated to develop similar legislation and the decision of the court may have a significant impact on the future of our cities.
- Full Text:
- Date Issued: 2009
- Authors: Pithouse, Richard, 1970-
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6201 , http://hdl.handle.net/10962/d1008568
- Description: [From introduction]: On 14 May 2009 the Constitutional Court will hear the attempt by the shack dweller’s movement Abahlali baseMjondolo to have the KwaZulu-Natal Slums Act declared unlawful. Other provinces have been mandated to develop similar legislation and the decision of the court may have a significant impact on the future of our cities.
- Full Text:
- Date Issued: 2009
Investigating how the attributes of live theatre productions influence consumption choices using conjoint analysis : the example of the National Arts Festival, South Africa
- Willis, K G, Snowball, Jeanette D
- Authors: Willis, K G , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6075 , http://hdl.handle.net/10962/d1003825 , http://dx.doi.org/10.1007/s10824-009-9097-z
- Description: While there is a fair amount of work on determinants of demand for the live performing arts, results have often been contradictory with little explanatory power. This may be because of the difficulty in describing the attributes of a performance, particularly in terms of its quality, and the heterogeneity of consumer preferences. This article uses conjoint analysis, also called choice experiments, to investigate the impact of the attributes of live theatre performances on demand, using data collected from 483 randomly chosen attenders at live theatre performances at the 2008 South African National Arts Festival. Attributes include the type of cast (professional, semi-professional or amateur), reputation of the producer/director, the context or setting, production type and ticket price of the show. Results largely support the a priori expectations based on the results of other demand studies. For example, it is found that the age of consumers affects the type of show chosen, that utility and willingness to pay increase for shows with professional and semi-professional casts and that 93% of the potential audience prefer shows with a South African context. It is concluded that the method could prove useful to both event organisers and policy makers, especially where the goal is to broaden access to the arts.
- Full Text:
- Date Issued: 2009
- Authors: Willis, K G , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6075 , http://hdl.handle.net/10962/d1003825 , http://dx.doi.org/10.1007/s10824-009-9097-z
- Description: While there is a fair amount of work on determinants of demand for the live performing arts, results have often been contradictory with little explanatory power. This may be because of the difficulty in describing the attributes of a performance, particularly in terms of its quality, and the heterogeneity of consumer preferences. This article uses conjoint analysis, also called choice experiments, to investigate the impact of the attributes of live theatre performances on demand, using data collected from 483 randomly chosen attenders at live theatre performances at the 2008 South African National Arts Festival. Attributes include the type of cast (professional, semi-professional or amateur), reputation of the producer/director, the context or setting, production type and ticket price of the show. Results largely support the a priori expectations based on the results of other demand studies. For example, it is found that the age of consumers affects the type of show chosen, that utility and willingness to pay increase for shows with professional and semi-professional casts and that 93% of the potential audience prefer shows with a South African context. It is concluded that the method could prove useful to both event organisers and policy makers, especially where the goal is to broaden access to the arts.
- Full Text:
- Date Issued: 2009
Wealth differentiation in household use and trade in non-timber forest products in South Africa
- Paumgarten, Fiona, Shackleton, Charlie M
- Authors: Paumgarten, Fiona , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6646 , http://hdl.handle.net/10962/d1006892
- Description: Findings from southern Africa and internationally indicate the local use and trade of NTFPs to be significant however most present a composite picture, failing to account for intra-community socio-economic differences. These differences may have implications for policy and practice related to poverty alleviation and sustainable use. This paper reports on a study in South Africa which explored the relationship between household wealth and the use, procurement and sale of NTFPs in two villages. There was no influence of wealth on the proportion of households using or purchasing most of the NTFPs, or the number used. However, wealthier households bought significantly more resources per household, and poor households (at one village) sold significantly more. These results are discussed within the context of local conditions and poverty alleviation debates.
- Full Text:
- Date Issued: 2009
- Authors: Paumgarten, Fiona , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6646 , http://hdl.handle.net/10962/d1006892
- Description: Findings from southern Africa and internationally indicate the local use and trade of NTFPs to be significant however most present a composite picture, failing to account for intra-community socio-economic differences. These differences may have implications for policy and practice related to poverty alleviation and sustainable use. This paper reports on a study in South Africa which explored the relationship between household wealth and the use, procurement and sale of NTFPs in two villages. There was no influence of wealth on the proportion of households using or purchasing most of the NTFPs, or the number used. However, wealthier households bought significantly more resources per household, and poor households (at one village) sold significantly more. These results are discussed within the context of local conditions and poverty alleviation debates.
- Full Text:
- Date Issued: 2009
Rapid method for the quantitative determination of efavirenz in human plasma
- Kanfer, Isadore, Mogatle, Seloi
- Authors: Kanfer, Isadore , Mogatle, Seloi
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6388 , http://hdl.handle.net/10962/d1006309
- Description: A pharmacokinetic interaction study between efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV-1 infection, and an African traditional medicine, African potato in human subjects was undertaken. This necessitated the development and validation of a quantitative method for the analysis of EFV in plasma. A simple mobile phase consisting of 0.1 M formic acid, acetonitrile and methanol (43:52:5) was pumped at a low flow rate of 0.3 ml/min through a reverse phase Phenomenex® Luna C18 (2) (5 μm, 150 mm × 2.0 mm i.d.) column maintained at 40 °C. Diclofenac sodium was used as an internal standard (IS) and EFV and IS were monitored at 247 nm and 275 nm, respectively. A simple and rapid sample preparation involved the addition of mobile phase to 100 μl of plasma to precipitate plasma proteins followed by direct injection of 10 μl of supernatant onto the column. The procedures were validated according to international standards with good reproducibility and linear response (r = 0.9990). The intra- and inter-day accuracies were between 12.3 and 17.7% at the LLOQ and between −5.8 and 9.1% for the QC samples. The intra- and inter-day precision of EFV determinations were 5.1 or less and 7.2% RSD or less, respectively across the entire QC concentration range. Mean recovery based on high, medium and low quality control standards ranged between 92.7 and 94.1% with %RSD values better than 3%. Plasma samples were evaluated for short-term (ambient temperature for 6 h) and long-term (−10 ± 2 °C for 60 days) storage conditions and were found to be stable. The method described is cost-effective and has the necessary accuracy and precision for the rapid quantitative determination of EFV in human plasma.
- Full Text:
- Date Issued: 2009
- Authors: Kanfer, Isadore , Mogatle, Seloi
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6388 , http://hdl.handle.net/10962/d1006309
- Description: A pharmacokinetic interaction study between efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV-1 infection, and an African traditional medicine, African potato in human subjects was undertaken. This necessitated the development and validation of a quantitative method for the analysis of EFV in plasma. A simple mobile phase consisting of 0.1 M formic acid, acetonitrile and methanol (43:52:5) was pumped at a low flow rate of 0.3 ml/min through a reverse phase Phenomenex® Luna C18 (2) (5 μm, 150 mm × 2.0 mm i.d.) column maintained at 40 °C. Diclofenac sodium was used as an internal standard (IS) and EFV and IS were monitored at 247 nm and 275 nm, respectively. A simple and rapid sample preparation involved the addition of mobile phase to 100 μl of plasma to precipitate plasma proteins followed by direct injection of 10 μl of supernatant onto the column. The procedures were validated according to international standards with good reproducibility and linear response (r = 0.9990). The intra- and inter-day accuracies were between 12.3 and 17.7% at the LLOQ and between −5.8 and 9.1% for the QC samples. The intra- and inter-day precision of EFV determinations were 5.1 or less and 7.2% RSD or less, respectively across the entire QC concentration range. Mean recovery based on high, medium and low quality control standards ranged between 92.7 and 94.1% with %RSD values better than 3%. Plasma samples were evaluated for short-term (ambient temperature for 6 h) and long-term (−10 ± 2 °C for 60 days) storage conditions and were found to be stable. The method described is cost-effective and has the necessary accuracy and precision for the rapid quantitative determination of EFV in human plasma.
- Full Text:
- Date Issued: 2009