Biological responses to a resumption in river flow in a freshwater-deprived, permanently open Southern African estuary
- Vorwerk, Paul D, Froneman, P William, Paterson, Angus W, Strydom, Nadine A, Whitfield, A K
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W , Strydom, Nadine A , Whitfield, A K
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6886 , http://hdl.handle.net/10962/d1011645
- Description: The Kariega Estuary is a freshwater-deprived system due to numerous impoundments in the catchment. This system has had little or no horizontal salinity gradient over the last 15 years, with hypersaline conditions sometimes predominating in the upper reaches. Following high rainfall events in the catchment during the spring of 2006, including a flood event (approximate 1:10 year) in August 2006, a series of riverine pulses entered the estuary and a horizontal salinity gradient was established. This study examined the influence of this freshwater pulse on four components of the biota within the estuary, namely the zooplankton, and larval, littoral and demersal fishes. The study demonstrated that in three of these components elevated densities were recorded following the riverine input, with only the littoral fishes retaining an almost constant density. In addition, changes in the relative contributions of the estuarine utilisation classes for all three fish groups examined indicated that freshwater input into these systems positively influences the abundances. This has significant implications for water managers as it demonstrates the importance of an Ecological Reserve (defined as ‘the water required to protect the aquatic ecosystems of the water resource’) for this system.
- Full Text:
- Date Issued: 2008
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W , Strydom, Nadine A , Whitfield, A K
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6886 , http://hdl.handle.net/10962/d1011645
- Description: The Kariega Estuary is a freshwater-deprived system due to numerous impoundments in the catchment. This system has had little or no horizontal salinity gradient over the last 15 years, with hypersaline conditions sometimes predominating in the upper reaches. Following high rainfall events in the catchment during the spring of 2006, including a flood event (approximate 1:10 year) in August 2006, a series of riverine pulses entered the estuary and a horizontal salinity gradient was established. This study examined the influence of this freshwater pulse on four components of the biota within the estuary, namely the zooplankton, and larval, littoral and demersal fishes. The study demonstrated that in three of these components elevated densities were recorded following the riverine input, with only the littoral fishes retaining an almost constant density. In addition, changes in the relative contributions of the estuarine utilisation classes for all three fish groups examined indicated that freshwater input into these systems positively influences the abundances. This has significant implications for water managers as it demonstrates the importance of an Ecological Reserve (defined as ‘the water required to protect the aquatic ecosystems of the water resource’) for this system.
- Full Text:
- Date Issued: 2008
Recovery of the critically endangered river pipefish, Syngnathus watermeyeri, in the Kariega Estuary, Eastern Cape province
- Vorwerk, Paul D, Froneman, P William, Paterson, Angus W
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6965 , http://hdl.handle.net/10962/d1012028
- Description: An intensive ichthyofaunal survey in the permanently open Kariega Estuary along the Eastern Cape coast has identified a breeding population of the critically endangered river pipefish, Syngnathus watermeyeri, within the middle and upper reaches of the system. This is the first recorded capture of this species in the estuary for over four decades. We suggest that the presence of S. watermeyeri is the result of the heavy rainfall within the region, which contributed to the establishment of optimum habitat requirements (mesohaline conditions and increased food availability) of the pipefish.
- Full Text:
- Date Issued: 2007
- Authors: Vorwerk, Paul D , Froneman, P William , Paterson, Angus W
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6965 , http://hdl.handle.net/10962/d1012028
- Description: An intensive ichthyofaunal survey in the permanently open Kariega Estuary along the Eastern Cape coast has identified a breeding population of the critically endangered river pipefish, Syngnathus watermeyeri, within the middle and upper reaches of the system. This is the first recorded capture of this species in the estuary for over four decades. We suggest that the presence of S. watermeyeri is the result of the heavy rainfall within the region, which contributed to the establishment of optimum habitat requirements (mesohaline conditions and increased food availability) of the pipefish.
- Full Text:
- Date Issued: 2007
The reintroduction of large carnivores to the Eastern Cape, South Africa: an assessment
- Hayward, M W, Kerley, Graham I H, Adendorff, John, Moolman, Lucius C, O'Brien, John, Sholto-Douglas, Angus, Bissett, Charlene, Bean, Peter, Fogarty, Alan, Howarth, Dale, Slater, Richard
- Authors: Hayward, M W , Kerley, Graham I H , Adendorff, John , Moolman, Lucius C , O'Brien, John , Sholto-Douglas, Angus , Bissett, Charlene , Bean, Peter , Fogarty, Alan , Howarth, Dale , Slater, Richard
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6900 , http://hdl.handle.net/10962/d1011662 , http://dx.doi.org/10.1017/S0030605307001767
- Description: Recently, conservation estate in South Africa's Eastern Cape Province has increased 10-fold resulting in large predators being increasingly reintroduced to restore ecological integrity and maximize tourism. We describe the reintroductions of large carnivores (>10 kg) that have occurred in the Eastern Cape and use various criteria to assess their success. Lion Panthera leo reintroduction has been highly successful with a population of 56 currently extant in the region and problems of overpopulation arising. The African wild dog Lycaon pictus population has increased to 24 from a founder population of 11. Preliminary results for spotted hyaenas Crocuta crocuta also indicate success. Wild populations of leopards Panthera pardus exist on several reserves and have been supplemented by translocated individuals, although deaths of known individuals have occurred and no estimate of reproduction is available. Cheetah Acinonyx jubatus reintroduction has also been less successful with 36 individuals reintroduced and 23 cubs being born but only 41 individuals surviving in 2005. Criteria for assessing the success of reintroductions of species that naturally occur in low densities, such as top predators, generally have limited value. Carrying capacity for large predators is unknown and continued monitoring and intensive management will be necessary in enclosed, and possibly all, conservation areas in the Eastern Cape to ensure conservation success.
- Full Text:
- Date Issued: 2007
- Authors: Hayward, M W , Kerley, Graham I H , Adendorff, John , Moolman, Lucius C , O'Brien, John , Sholto-Douglas, Angus , Bissett, Charlene , Bean, Peter , Fogarty, Alan , Howarth, Dale , Slater, Richard
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6900 , http://hdl.handle.net/10962/d1011662 , http://dx.doi.org/10.1017/S0030605307001767
- Description: Recently, conservation estate in South Africa's Eastern Cape Province has increased 10-fold resulting in large predators being increasingly reintroduced to restore ecological integrity and maximize tourism. We describe the reintroductions of large carnivores (>10 kg) that have occurred in the Eastern Cape and use various criteria to assess their success. Lion Panthera leo reintroduction has been highly successful with a population of 56 currently extant in the region and problems of overpopulation arising. The African wild dog Lycaon pictus population has increased to 24 from a founder population of 11. Preliminary results for spotted hyaenas Crocuta crocuta also indicate success. Wild populations of leopards Panthera pardus exist on several reserves and have been supplemented by translocated individuals, although deaths of known individuals have occurred and no estimate of reproduction is available. Cheetah Acinonyx jubatus reintroduction has also been less successful with 36 individuals reintroduced and 23 cubs being born but only 41 individuals surviving in 2005. Criteria for assessing the success of reintroductions of species that naturally occur in low densities, such as top predators, generally have limited value. Carrying capacity for large predators is unknown and continued monitoring and intensive management will be necessary in enclosed, and possibly all, conservation areas in the Eastern Cape to ensure conservation success.
- Full Text:
- Date Issued: 2007
New possibilities for research on reef fish across the continental shelf of South Africa
- Bernard, Anthony T F, Gotz, A, Parker, Daniel M, Heyns, Elodie R, Halse, S J, Riddin, N A, Smith, M K S, Paterson, Angus W, Winker, A Henning, Fullwood, L, Langlois, T J, Harvey, E S
- Authors: Bernard, Anthony T F , Gotz, A , Parker, Daniel M , Heyns, Elodie R , Halse, S J , Riddin, N A , Smith, M K S , Paterson, Angus W , Winker, A Henning , Fullwood, L , Langlois, T J , Harvey, E S
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6971 , http://hdl.handle.net/10962/d1014566
- Description: [From introduction] Subtidal research presents numerous challenges that restrict the ability to answer fundamental ecological questions related to reef systems. These challenges are closely associated with traditional monitoring methods and include depth restrictions (e.g. safe diving depths for underwater visual census), habitat destruction (e.g. trawling), mortality of target species (e.g. controlled angling and fish traps), and high operating costs (e.g. remotely operated vehicles and large research vessels. Whereas many of these challenges do not apply or are avoidable in the shallow subtidal environment, the difficulties grow as one attempts to sample deeper benthic habitats. This situation has resulted in a paucity of knowledge on the structure and ecology of deep water reef habitats around the coast of South Africa and in most marine areas around the world. Furthermore, the inability to effectively survey deep water benthic environments has limited the capacity of researchers to investigate connectivity between shallow and deep water habitats in a standardised and comparable fashion.
- Full Text:
- Date Issued: 2014
- Authors: Bernard, Anthony T F , Gotz, A , Parker, Daniel M , Heyns, Elodie R , Halse, S J , Riddin, N A , Smith, M K S , Paterson, Angus W , Winker, A Henning , Fullwood, L , Langlois, T J , Harvey, E S
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6971 , http://hdl.handle.net/10962/d1014566
- Description: [From introduction] Subtidal research presents numerous challenges that restrict the ability to answer fundamental ecological questions related to reef systems. These challenges are closely associated with traditional monitoring methods and include depth restrictions (e.g. safe diving depths for underwater visual census), habitat destruction (e.g. trawling), mortality of target species (e.g. controlled angling and fish traps), and high operating costs (e.g. remotely operated vehicles and large research vessels. Whereas many of these challenges do not apply or are avoidable in the shallow subtidal environment, the difficulties grow as one attempts to sample deeper benthic habitats. This situation has resulted in a paucity of knowledge on the structure and ecology of deep water reef habitats around the coast of South Africa and in most marine areas around the world. Furthermore, the inability to effectively survey deep water benthic environments has limited the capacity of researchers to investigate connectivity between shallow and deep water habitats in a standardised and comparable fashion.
- Full Text:
- Date Issued: 2014
Predicting geographic distribution of seven blowfly species (Diptera: Calliphoridae) in South Africa
- Richards, C S, Williams, K A, Villet, Martin H
- Authors: Richards, C S , Williams, K A , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6854 , http://hdl.handle.net/10962/d1011135
- Description: The predicted geographic distributions of seven forensically important blowfly species are modelled using the computer program Maxent, based on selected climatic variables for South Africa, a country with large climatic and environmental gradients. It is shown that although temperature was hypothesized to most influence the distributions of these ectotherms, moisture, and particularly humidity, was in fact usually paramount. Chrysomya albiceps (Wiedemann) and C. marginalis (Robineau-Desvoidy) had the most widespread geographic and climatic distribution, while the forest-associated C. inclinata(Walker) was the least widespread. Chrysomya putoria (Wiedemann) and C. megacephala (Fabricius) had very similar predicted distributions that were restricted mainly to Limpopo, Mpumalanga, KwaZulu-Natal and the coast of the Eastern Cape. Chrysomya chloropyga (Wiedemann) and Calliphora croceipalpis (Jaennicke) were the only species predicted to occur at high altitudes. Blowfly distributions restricted to part of the map area were predicted better than those that were more widespread in the region, presumably because species with extremely widespread distributions in a study area occupy nearly the whole range of variation of most predictor variables, leaving little variation with which themaximumentropy modelling method can discriminate between presence and absence of the organism.
- Full Text:
- Date Issued: 2009
Predicting geographic distribution of seven blowfly species (Diptera: Calliphoridae) in South Africa
- Authors: Richards, C S , Williams, K A , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6854 , http://hdl.handle.net/10962/d1011135
- Description: The predicted geographic distributions of seven forensically important blowfly species are modelled using the computer program Maxent, based on selected climatic variables for South Africa, a country with large climatic and environmental gradients. It is shown that although temperature was hypothesized to most influence the distributions of these ectotherms, moisture, and particularly humidity, was in fact usually paramount. Chrysomya albiceps (Wiedemann) and C. marginalis (Robineau-Desvoidy) had the most widespread geographic and climatic distribution, while the forest-associated C. inclinata(Walker) was the least widespread. Chrysomya putoria (Wiedemann) and C. megacephala (Fabricius) had very similar predicted distributions that were restricted mainly to Limpopo, Mpumalanga, KwaZulu-Natal and the coast of the Eastern Cape. Chrysomya chloropyga (Wiedemann) and Calliphora croceipalpis (Jaennicke) were the only species predicted to occur at high altitudes. Blowfly distributions restricted to part of the map area were predicted better than those that were more widespread in the region, presumably because species with extremely widespread distributions in a study area occupy nearly the whole range of variation of most predictor variables, leaving little variation with which themaximumentropy modelling method can discriminate between presence and absence of the organism.
- Full Text:
- Date Issued: 2009
Recent African derivation of Chrysomya putoria from C. chloropyga and mitochondrial DNA paraphyly of cytochrome oxidase subunit one in blowflies of forensic importance
- Wells, J D, Lunt, N, Villet, Martin H
- Authors: Wells, J D , Lunt, N , Villet, Martin H
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6888 , http://hdl.handle.net/10962/d1011648
- Description: Chrysomya chloropyga (Wiedemann) and C. putoria (Wiedemann) (Diptera: Calliphoridae) are closely related Afrotropical blowflies that breed in carrion and latrines, reaching high density in association with humans and spreading to other continents. In some cases of human death, Chyrsomya specimens provide forensic clues. Because the immature stages of such flies are often difficult to identify taxonomically, it is useful to develop DNA-based tests for specimen identification. Therefore we attempted to distinguish between C. chloropyga and C. putoria using mitochondrial DNA (mtDNA) sequence data from a 593-bp region of the gene for cytochrome oxidase subunit one (COI). Twelve specimens from each species yielded a total of five haplotypes, none being unique to C. putoria. Therefore it was not possible to distinguish between the two species using this locus. Maximum parsimony analysis indicated paraphyletic C. chloropyga mtDNA with C. putoria nested therein. Based on these and previously published data, we infer that C. putoria diverged very recently from C. chloropyga.
- Full Text:
- Date Issued: 2004
- Authors: Wells, J D , Lunt, N , Villet, Martin H
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6888 , http://hdl.handle.net/10962/d1011648
- Description: Chrysomya chloropyga (Wiedemann) and C. putoria (Wiedemann) (Diptera: Calliphoridae) are closely related Afrotropical blowflies that breed in carrion and latrines, reaching high density in association with humans and spreading to other continents. In some cases of human death, Chyrsomya specimens provide forensic clues. Because the immature stages of such flies are often difficult to identify taxonomically, it is useful to develop DNA-based tests for specimen identification. Therefore we attempted to distinguish between C. chloropyga and C. putoria using mitochondrial DNA (mtDNA) sequence data from a 593-bp region of the gene for cytochrome oxidase subunit one (COI). Twelve specimens from each species yielded a total of five haplotypes, none being unique to C. putoria. Therefore it was not possible to distinguish between the two species using this locus. Maximum parsimony analysis indicated paraphyletic C. chloropyga mtDNA with C. putoria nested therein. Based on these and previously published data, we infer that C. putoria diverged very recently from C. chloropyga.
- Full Text:
- Date Issued: 2004
A history of southern African research relevant to forensic entomology
- Williams, K A, Villet, Martin H
- Authors: Williams, K A , Villet, Martin H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6909 , http://hdl.handle.net/10962/d1011862
- Description: Entomological forensic evidence has been used in southern Africa for decades but explicitly forensic research began in southern Africa only 26 years ago. Although applicable local research has accumulated since 1921, it is scattered in a diverse literature or unpublished. Some overseas research has also touched on local species. This review uses a historical approach to synthesize the southern African literature and to illustrate the cross-disciplinary, opportunistic nature of forensic entomology. Distinct phases of research focused on agriculture (1921-1950), medicine (1952- 1965), ecology (1968-1990) and forensics (1980-2005), but systematics spanned the entire period and tended to be ad hoc. Few scientists were involved, situated at geographically distant locations and with widely disparate research interests. The review concludes with an overview of southern African entomologists who have been involved in medico-legal investigations, and a critical evaluation of the past and future of the discipline locally.
- Full Text:
- Date Issued: 2006
- Authors: Williams, K A , Villet, Martin H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6909 , http://hdl.handle.net/10962/d1011862
- Description: Entomological forensic evidence has been used in southern Africa for decades but explicitly forensic research began in southern Africa only 26 years ago. Although applicable local research has accumulated since 1921, it is scattered in a diverse literature or unpublished. Some overseas research has also touched on local species. This review uses a historical approach to synthesize the southern African literature and to illustrate the cross-disciplinary, opportunistic nature of forensic entomology. Distinct phases of research focused on agriculture (1921-1950), medicine (1952- 1965), ecology (1968-1990) and forensics (1980-2005), but systematics spanned the entire period and tended to be ad hoc. Few scientists were involved, situated at geographically distant locations and with widely disparate research interests. The review concludes with an overview of southern African entomologists who have been involved in medico-legal investigations, and a critical evaluation of the past and future of the discipline locally.
- Full Text:
- Date Issued: 2006
The crystal and molecular structure of the bis(4-N, N1-dimethylaminopyridine) solvate of disalicylicacidatobis(nitrotodioxouranium)(VI)
- Nassimbeni, L R, Rodgers, Allen L, Haigh, John M
- Authors: Nassimbeni, L R , Rodgers, Allen L , Haigh, John M
- Date: 1976
- Language: English
- Type: text , Article
- Identifier: vital:6415 , http://hdl.handle.net/10962/d1006526
- Description: The structure of the title compound [(C7H4NO8U)(C7H11N2)]2 has been determined by Patterson and Fourier methods from single crystal X-ray diffraction data collected on a four-circle diffractometer. Full-matrix least-squares refinement yielded a final conventional R of 0.041 for 2189 reflections. The complex crystallizes in the space group P with a = 11.004(5), b = 9.981(5), c = 9.928(5) Å, α = 119.6(3), β = 107.7(3), γ = 81.9(3)°, Dm = 2.17, Dc = 2.173g cm−3. The structure is dimeric. The uranium atoms are eight-coordinate and are bridged via centrosymmetrically related carboxylic oxygen atoms. The nitrate group is bidentate and the average U---O (ligand) distance is 2.463 Å. Hydrogen bonding of the type N---HO links two dimethyl-aminopyridine molecules to the dimer.
- Full Text:
- Date Issued: 1976
- Authors: Nassimbeni, L R , Rodgers, Allen L , Haigh, John M
- Date: 1976
- Language: English
- Type: text , Article
- Identifier: vital:6415 , http://hdl.handle.net/10962/d1006526
- Description: The structure of the title compound [(C7H4NO8U)(C7H11N2)]2 has been determined by Patterson and Fourier methods from single crystal X-ray diffraction data collected on a four-circle diffractometer. Full-matrix least-squares refinement yielded a final conventional R of 0.041 for 2189 reflections. The complex crystallizes in the space group P with a = 11.004(5), b = 9.981(5), c = 9.928(5) Å, α = 119.6(3), β = 107.7(3), γ = 81.9(3)°, Dm = 2.17, Dc = 2.173g cm−3. The structure is dimeric. The uranium atoms are eight-coordinate and are bridged via centrosymmetrically related carboxylic oxygen atoms. The nitrate group is bidentate and the average U---O (ligand) distance is 2.463 Å. Hydrogen bonding of the type N---HO links two dimethyl-aminopyridine molecules to the dimer.
- Full Text:
- Date Issued: 1976
Threatened plants of the Albany Centre of Floristic Endemism, South Africa
- Victor, A E, Dold, Anthony P
- Authors: Victor, A E , Dold, Anthony P
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6555 , http://hdl.handle.net/10962/d1006013
- Description: We present Red List assessments of threatened plants of the Albany Centre of Floristic Endemism in the Eastern Cape province of South Africa. We evaluated the status of taxa using categories and criteria adopted by the World Conservation Union (IUCN) in 1994 and updated in 2001. In total, 126 taxa are threatened with extinction in the Albany Centre, and six are now extinct. A further 22 are listed as Data Deficient. In the past, agriculture has been a severe threat to the survival of rare species in this part of the Eastern Cape; the main threats to the continuing existence of threatened plants in this area are illegal collecting, residential development and urban growth.
- Full Text:
- Date Issued: 2003
- Authors: Victor, A E , Dold, Anthony P
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6555 , http://hdl.handle.net/10962/d1006013
- Description: We present Red List assessments of threatened plants of the Albany Centre of Floristic Endemism in the Eastern Cape province of South Africa. We evaluated the status of taxa using categories and criteria adopted by the World Conservation Union (IUCN) in 1994 and updated in 2001. In total, 126 taxa are threatened with extinction in the Albany Centre, and six are now extinct. A further 22 are listed as Data Deficient. In the past, agriculture has been a severe threat to the survival of rare species in this part of the Eastern Cape; the main threats to the continuing existence of threatened plants in this area are illegal collecting, residential development and urban growth.
- Full Text:
- Date Issued: 2003
The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in biological fluids by high pressure liquid chromatography
- Gochin, Rosa, Kanfer, Isadore, Haigh, John M
- Authors: Gochin, Rosa , Kanfer, Isadore , Haigh, John M
- Date: 1981
- Language: English
- Type: text , Article
- Identifier: vital:6364 , http://hdl.handle.net/10962/d1006064
- Description: The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in serum and urine by high-performance liquid chromatography using sulphafurazole as internal standard is described. The separation was achieved on a reversed-phase column employing acetic acid-methanol as the mobile phase with spectrophotometric detection at 230 nm. Precise simultaneous quantitative analysis of the relative components has been achieved at levels of 0.1 μg/ml for both sulphamethoxazole and its N4-acetyl metabolite using 1 ml of serum or urine.
- Full Text:
- Date Issued: 1981
- Authors: Gochin, Rosa , Kanfer, Isadore , Haigh, John M
- Date: 1981
- Language: English
- Type: text , Article
- Identifier: vital:6364 , http://hdl.handle.net/10962/d1006064
- Description: The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in serum and urine by high-performance liquid chromatography using sulphafurazole as internal standard is described. The separation was achieved on a reversed-phase column employing acetic acid-methanol as the mobile phase with spectrophotometric detection at 230 nm. Precise simultaneous quantitative analysis of the relative components has been achieved at levels of 0.1 μg/ml for both sulphamethoxazole and its N4-acetyl metabolite using 1 ml of serum or urine.
- Full Text:
- Date Issued: 1981
The evaluation of pharmaceutical pictograms in a low-literate South African population
- Dowse, Roslind, Ehlers, Martina S
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
- Full Text:
- Date Issued: 2001
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
- Full Text:
- Date Issued: 2001
The identity of Albuca caudata Jacq. (Hyacinthaceae) and a description of a new related species : A. bakeri
- Martinez-Azorin, Mario, Cresbo, Manuel B, Dold, Anthony P, Barker, Nigel P
- Authors: Martinez-Azorin, Mario , Cresbo, Manuel B , Dold, Anthony P , Barker, Nigel P
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6528 , http://hdl.handle.net/10962/d1005969
- Description: The name Albuca caudata Jacq. has been widely misunderstood or even ignored since its description in 1791. After studying herbarium specimens and living populations in South Africa, plants fitting Jacquin´s concept of that species are found to be widely distributed in the Eastern Cape, mainly in the Albany centre of Endemism. Furthermore, some divergent specimens matching Baker´s concept of Albuca caudata are described as a new related species: Albuca bakeri. Data on typification, morphology, ecology, and distribution are reported for both taxa. Affinities and divergences with other close allies are also discussed.
- Full Text:
- Date Issued: 2011
- Authors: Martinez-Azorin, Mario , Cresbo, Manuel B , Dold, Anthony P , Barker, Nigel P
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6528 , http://hdl.handle.net/10962/d1005969
- Description: The name Albuca caudata Jacq. has been widely misunderstood or even ignored since its description in 1791. After studying herbarium specimens and living populations in South Africa, plants fitting Jacquin´s concept of that species are found to be widely distributed in the Eastern Cape, mainly in the Albany centre of Endemism. Furthermore, some divergent specimens matching Baker´s concept of Albuca caudata are described as a new related species: Albuca bakeri. Data on typification, morphology, ecology, and distribution are reported for both taxa. Affinities and divergences with other close allies are also discussed.
- Full Text:
- Date Issued: 2011
Infrared evidence for the transmission of electronic effects through a metal atom in a series of new cadmium complexes
- Haigh, John M, Van Dam, M A, Thornton, D A
- Authors: Haigh, John M , Van Dam, M A , Thornton, D A
- Date: 1967
- Language: English
- Type: text , Article
- Identifier: vital:6371 , http://hdl.handle.net/10962/d1006073
- Description: A series of novel cadmium complexes has been synthesized from the reaction of cadmium chloride, bromide and iodide with primary aromatic amines. The complexes are either mononuclear or polynuclear according to the nature of the halide and amine employed. A possible mechanism for their formation is proposed. The N - H stretching and bending frequencies are linearly related to the electronegativity of the co-ordinated halogen, indicating that the electron withdrawing capacity of the halogen is transmitted through the cadmium atom.
- Full Text:
- Date Issued: 1967
- Authors: Haigh, John M , Van Dam, M A , Thornton, D A
- Date: 1967
- Language: English
- Type: text , Article
- Identifier: vital:6371 , http://hdl.handle.net/10962/d1006073
- Description: A series of novel cadmium complexes has been synthesized from the reaction of cadmium chloride, bromide and iodide with primary aromatic amines. The complexes are either mononuclear or polynuclear according to the nature of the halide and amine employed. A possible mechanism for their formation is proposed. The N - H stretching and bending frequencies are linearly related to the electronegativity of the co-ordinated halogen, indicating that the electron withdrawing capacity of the halogen is transmitted through the cadmium atom.
- Full Text:
- Date Issued: 1967
The importance of phytoplankton size in mediating trophic interactions within the plankton of a southern African estuary
- Authors: Froneman, P William
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6928 , http://hdl.handle.net/10962/d1011944
- Description: The influence of the phytoplankton size composition in mediating the trophic interactions between the bacteria, phytoplankton, microheterotrophs (<200 μm) and mesozooplankton (>200 μm) was investigated on three occasions in a warm temperate, temporarily open/closed estuary situated along the southern African coastline. Results of the investigation indicated that the microheterotrophs represented the most important consumers of bacteria and chlorophyll (chl)-a <5.0 μm. The low impact of the mesozooplankton on the bacteria and chl-a <5.0 μm during the study appeared to be related to the inability of the larger zooplankton to feed efficiently on small particles. During those periods when total chl-a concentration was dominated by picophytoplankton (<2.0 μm) and microphytoplankton (>20 μm), mesozooplankton were unable to feed efficiently on the chl-a due to feeding constraints. In response to the unfavorable size structure of the phytoplankton assemblages, mesozooplankton appeared to consume the microheterotrophs. The negative impact of the mesozooplankton on the microheterotrophs resulted in a decrease in the impact of these organisms on the bacteria and the chl-a <5.0 μm. This result is consistent with the predator-prey cascades. On the other hand, when the total chl-a was dominated by nanophytoplankton (2–20 μm), mesozooplankton were able to feed directly on the phytoplankton. Results of the study indicate that size structure of the phytoplankton assemblages within estuaries plays an important role in mediating the trophic interactions between the various components of the plankton food web.
- Full Text:
- Date Issued: 2006
- Authors: Froneman, P William
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6928 , http://hdl.handle.net/10962/d1011944
- Description: The influence of the phytoplankton size composition in mediating the trophic interactions between the bacteria, phytoplankton, microheterotrophs (<200 μm) and mesozooplankton (>200 μm) was investigated on three occasions in a warm temperate, temporarily open/closed estuary situated along the southern African coastline. Results of the investigation indicated that the microheterotrophs represented the most important consumers of bacteria and chlorophyll (chl)-a <5.0 μm. The low impact of the mesozooplankton on the bacteria and chl-a <5.0 μm during the study appeared to be related to the inability of the larger zooplankton to feed efficiently on small particles. During those periods when total chl-a concentration was dominated by picophytoplankton (<2.0 μm) and microphytoplankton (>20 μm), mesozooplankton were unable to feed efficiently on the chl-a due to feeding constraints. In response to the unfavorable size structure of the phytoplankton assemblages, mesozooplankton appeared to consume the microheterotrophs. The negative impact of the mesozooplankton on the microheterotrophs resulted in a decrease in the impact of these organisms on the bacteria and the chl-a <5.0 μm. This result is consistent with the predator-prey cascades. On the other hand, when the total chl-a was dominated by nanophytoplankton (2–20 μm), mesozooplankton were able to feed directly on the phytoplankton. Results of the study indicate that size structure of the phytoplankton assemblages within estuaries plays an important role in mediating the trophic interactions between the various components of the plankton food web.
- Full Text:
- Date Issued: 2006
Enlarged arguments in Bantu : evidence from Chichewa
- Authors: Simango, Silvester Ron
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6140 , http://hdl.handle.net/10962/d1011592
- Description: This paper re-examines two types of constructions that have featured in the discussion of possessor ascension in Bantu: one type – an applicative construction – is associated with alienable possession, and the other – non-applicative – is associated with inalienable possession. The study shows that the former expresses affectedness, and that the possessor reading arises only by construal; whereas the latter expresses a part–whole relationship. The paper argues that the two constructions differ in more significant ways than has previously been acknowledged; and that their distinct derivations cannot be captured by traditional possessor ascension (PA) analyses. The putative “alienable” possessor constructions belong to the class of (benefactive) applicative constructions and should be analyzed as such. The paper proposes that the so-called “inalienable” possessor constructions can best be accounted for by positing the existence of “enlarged arguments” wherein the possessum functions as a nominal predicate which more narrowly pinpoints the locus of the action described by the verb.
- Full Text:
- Date Issued: 2007
- Authors: Simango, Silvester Ron
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6140 , http://hdl.handle.net/10962/d1011592
- Description: This paper re-examines two types of constructions that have featured in the discussion of possessor ascension in Bantu: one type – an applicative construction – is associated with alienable possession, and the other – non-applicative – is associated with inalienable possession. The study shows that the former expresses affectedness, and that the possessor reading arises only by construal; whereas the latter expresses a part–whole relationship. The paper argues that the two constructions differ in more significant ways than has previously been acknowledged; and that their distinct derivations cannot be captured by traditional possessor ascension (PA) analyses. The putative “alienable” possessor constructions belong to the class of (benefactive) applicative constructions and should be analyzed as such. The paper proposes that the so-called “inalienable” possessor constructions can best be accounted for by positing the existence of “enlarged arguments” wherein the possessum functions as a nominal predicate which more narrowly pinpoints the locus of the action described by the verb.
- Full Text:
- Date Issued: 2007
Rare earth element geochemistry of the Insizwa lobe of the Mount Ayliff Complex, Eastern Cape, South Africa
- Authors: Marsh, Julian S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6736 , http://hdl.handle.net/10962/d1007548
- Description: New rare earth element (REE) data from all lithologies of the Insizwa lobe, Mount Ayliff Complex, are presented. On the basis of size and type of Eu anomaly, the geochemical subdivision of the complex as previously described is sustained and, additionally, the Top Gabbronorite of the Central Zone is shown to have formed from a magma that was compositionally distinct from other Central Zone magmas. The Basal Zone crystallized from magmas with large negative Eu anomalies probably acquired through crustal contamination. Previously recognized compositional heterogeneity in the contact rocks is also a feature of the REE. Overall, the Insizwa magmas had higher La/Sm ratios and, to a lesser extent, higher Gd/Yb ratios than Karoo basalts and appear to have no representatives in the basalt lava sequence of Lesotho.
- Full Text:
- Date Issued: 2004
- Authors: Marsh, Julian S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6736 , http://hdl.handle.net/10962/d1007548
- Description: New rare earth element (REE) data from all lithologies of the Insizwa lobe, Mount Ayliff Complex, are presented. On the basis of size and type of Eu anomaly, the geochemical subdivision of the complex as previously described is sustained and, additionally, the Top Gabbronorite of the Central Zone is shown to have formed from a magma that was compositionally distinct from other Central Zone magmas. The Basal Zone crystallized from magmas with large negative Eu anomalies probably acquired through crustal contamination. Previously recognized compositional heterogeneity in the contact rocks is also a feature of the REE. Overall, the Insizwa magmas had higher La/Sm ratios and, to a lesser extent, higher Gd/Yb ratios than Karoo basalts and appear to have no representatives in the basalt lava sequence of Lesotho.
- Full Text:
- Date Issued: 2004
Patterns and processes underlying evolutionary significant units in the Platypleura stridula L. species complex (Hemiptera: Cicadidae) in the Cape Floristic Region, South Africa
- Price, Benjamin W, Barker, Nigel P, Villet, Martin H
- Authors: Price, Benjamin W , Barker, Nigel P , Villet, Martin H
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6964 , http://hdl.handle.net/10962/d1012027
- Description: Cicadas have been shown to be useful organisms for examining the effects of distribution, plant association and geographical barriers on gene flow between populations. The cicadas of the Platypleura stridula species complex are restricted to the biologically diverse Cape Floristic Region (CFR) of South Africa. They are thus an excellent study group for elucidating the mechanisms by which hemipteran diversity is generated and maintained in the CFR. Phylogeographical analysis of this species complex using mitochondrial DNA Cytochrome Oxidase I (COI) and ribosomal 16S sequence data, coupled with preliminary morphological and acoustic data, resolves six clades, each of which has specific host-plant associations and distinct geographical ranges. The phylogeographical structure implies simultaneous or near-simultaneous radiation events, coupled with shifts in host-plant associations. When calibrated using published COI and 16S substitution rates typical for related insects, these lineages date back to the late Pliocene - early Pleistocene, coincident with vegetation change, altered drainage patterns and accelerated erosion in response to neotectonic crustal uplift and cyclic Pleistocene climate change, and glaciation-associated changes in climate and sea level.
- Full Text:
- Date Issued: 2007
- Authors: Price, Benjamin W , Barker, Nigel P , Villet, Martin H
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6964 , http://hdl.handle.net/10962/d1012027
- Description: Cicadas have been shown to be useful organisms for examining the effects of distribution, plant association and geographical barriers on gene flow between populations. The cicadas of the Platypleura stridula species complex are restricted to the biologically diverse Cape Floristic Region (CFR) of South Africa. They are thus an excellent study group for elucidating the mechanisms by which hemipteran diversity is generated and maintained in the CFR. Phylogeographical analysis of this species complex using mitochondrial DNA Cytochrome Oxidase I (COI) and ribosomal 16S sequence data, coupled with preliminary morphological and acoustic data, resolves six clades, each of which has specific host-plant associations and distinct geographical ranges. The phylogeographical structure implies simultaneous or near-simultaneous radiation events, coupled with shifts in host-plant associations. When calibrated using published COI and 16S substitution rates typical for related insects, these lineages date back to the late Pliocene - early Pleistocene, coincident with vegetation change, altered drainage patterns and accelerated erosion in response to neotectonic crustal uplift and cyclic Pleistocene climate change, and glaciation-associated changes in climate and sea level.
- Full Text:
- Date Issued: 2007
Karyology of three evolutionarily hexaploid southern African species of yellowfish, Labeobarbus Rüppel, 1836 (Cyprinidae)
- Naran, D, Skelton, Paul H, Villet, Martin H
- Authors: Naran, D , Skelton, Paul H , Villet, Martin H
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6855 , http://hdl.handle.net/10962/d1011138 , http://dx.doi.org/10.3377/1562-7020(2007)42[254:KOTEHS]2.0.CO;2
- Description: The karyotypes of three species of yellowfish, namely Labeobarbus marequensis (A. Smith, 1841), L. capensis (A. Smith, 1841) and L. polylepis (Boulenger, 1907), were examined by Giemsa staining using an approach improved for the description of high chromosome numbers. In each case, 2n = 150; no heteromorphic chromosomes were detected; chromosomes in all morphological categories ranged smoothly from large to small, with no distinctly large submetacentric pairs; and metacentric chromosomes showed little variation in size. Labeobarbus marequensis had 26 metacentric (m), 44 submetacentric (sm), 42 subtelocentric (st) and 38 acrocentric (a) chromosomes and a fundamental number (FN) of 262; L. capensis had 16 m, 58 sm, 42 st and 34 a chromosomes and FN = 266; and L. polylepis had 18 m, 60 sm, 42 st and 30 a chromosomes and FN = 270. These results, combined with published literature, imply that Labeobarbus Rüppel, 1836 is an evolutionarily hexaploid African lineage and support its removal from synonymy with the evolutionarily tetraploid Asian genus Tor Gray, 1834. A review of fundamental numbers for conspecific Labeobarbus species examined in different studies implicated karyological technique as a confounding factor in assessing details of karyotypes, leading to recommendations for future karyological studies of barbine fishes. Potential synapomorphies are pointed out in karyological characters of species within Labeobarbus.
- Full Text:
- Date Issued: 2007
- Authors: Naran, D , Skelton, Paul H , Villet, Martin H
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6855 , http://hdl.handle.net/10962/d1011138 , http://dx.doi.org/10.3377/1562-7020(2007)42[254:KOTEHS]2.0.CO;2
- Description: The karyotypes of three species of yellowfish, namely Labeobarbus marequensis (A. Smith, 1841), L. capensis (A. Smith, 1841) and L. polylepis (Boulenger, 1907), were examined by Giemsa staining using an approach improved for the description of high chromosome numbers. In each case, 2n = 150; no heteromorphic chromosomes were detected; chromosomes in all morphological categories ranged smoothly from large to small, with no distinctly large submetacentric pairs; and metacentric chromosomes showed little variation in size. Labeobarbus marequensis had 26 metacentric (m), 44 submetacentric (sm), 42 subtelocentric (st) and 38 acrocentric (a) chromosomes and a fundamental number (FN) of 262; L. capensis had 16 m, 58 sm, 42 st and 34 a chromosomes and FN = 266; and L. polylepis had 18 m, 60 sm, 42 st and 30 a chromosomes and FN = 270. These results, combined with published literature, imply that Labeobarbus Rüppel, 1836 is an evolutionarily hexaploid African lineage and support its removal from synonymy with the evolutionarily tetraploid Asian genus Tor Gray, 1834. A review of fundamental numbers for conspecific Labeobarbus species examined in different studies implicated karyological technique as a confounding factor in assessing details of karyotypes, leading to recommendations for future karyological studies of barbine fishes. Potential synapomorphies are pointed out in karyological characters of species within Labeobarbus.
- Full Text:
- Date Issued: 2007
Spectroscopic and photophysicochemical behaviour of novel cadmium phthalocyanine derivatives tetra-substituted at the alpha and beta positions
- Nyokong, Tebello, Chidawanyika, Wadzanai J U
- Authors: Nyokong, Tebello , Chidawanyika, Wadzanai J U
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6582 , http://hdl.handle.net/10962/d1004147
- Description: The syntheses of three cadmium phthalocyanine derivatives tetrakis{1,(4)-(4-benzyloxy)phenoxyphthalocyaninato} (5a), tetrakis{1,(4)-(2-pyridyloxy)phthalocyaninato} (5b) and tetrakis{2,(3)-(4-benzyloxy)phenoxyphthalocyaninato} (6a) are reported here for the first time. Spectroscopic and photophysical properties have also been determined and the results are discussed here paying particular attention to the influence of various organic solvents in relation to the position and type of substitution. Singlet oxygen quantum yields (ΦΔ) and photodegradation quantum yields (ΦPd) have also been discussed. The triplet quantum yields have been determined and ranged from ΦT = 0.36 to 0.85, where the peripherally (β) substituted derivatives generally give higher values than those substituted at the non-peripheral (α) positions. The triplet lifetimes ranged from τT = 5 to 40 μs. In all cases (except toluene, due to the lack of data), the highest singlet oxygen quantum yields obtained were for the pyridyloxy-substituted derivatives 5b (ΦΔ = 0.60 in DMF) and 6b (ΦΔ = 0.74 in DMSO).
- Full Text:
- Date Issued: 2009
- Authors: Nyokong, Tebello , Chidawanyika, Wadzanai J U
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6582 , http://hdl.handle.net/10962/d1004147
- Description: The syntheses of three cadmium phthalocyanine derivatives tetrakis{1,(4)-(4-benzyloxy)phenoxyphthalocyaninato} (5a), tetrakis{1,(4)-(2-pyridyloxy)phthalocyaninato} (5b) and tetrakis{2,(3)-(4-benzyloxy)phenoxyphthalocyaninato} (6a) are reported here for the first time. Spectroscopic and photophysical properties have also been determined and the results are discussed here paying particular attention to the influence of various organic solvents in relation to the position and type of substitution. Singlet oxygen quantum yields (ΦΔ) and photodegradation quantum yields (ΦPd) have also been discussed. The triplet quantum yields have been determined and ranged from ΦT = 0.36 to 0.85, where the peripherally (β) substituted derivatives generally give higher values than those substituted at the non-peripheral (α) positions. The triplet lifetimes ranged from τT = 5 to 40 μs. In all cases (except toluene, due to the lack of data), the highest singlet oxygen quantum yields obtained were for the pyridyloxy-substituted derivatives 5b (ΦΔ = 0.60 in DMF) and 6b (ΦΔ = 0.74 in DMSO).
- Full Text:
- Date Issued: 2009
Complexes of mercury(II) and zinc(II) with primary aromatic amines
- Haigh, John M, Van Dam, M A, Thornton, D A
- Authors: Haigh, John M , Van Dam, M A , Thornton, D A
- Date: 1967
- Language: English
- Type: text , Article
- Identifier: vital:6370 , http://hdl.handle.net/10962/d1006072
- Description: A series of amine complexes has been prepared by reaction of zinc chloride and mercuric chloride with primary aromatic amines. A detailed assignment of the bands in the infra-red spectra of the complexes in the range 4000-625 cm [superscript]-1 is presented. The symmetric and asymmetric N-H stretching frequencies follow the relationship v(sym) = 345.5+ 0.876v(asym). The C-N stretching frequencies exhibit a linear relationship with the Hammett α-functions for the m- and p-substituted amines.
- Full Text:
- Date Issued: 1967
- Authors: Haigh, John M , Van Dam, M A , Thornton, D A
- Date: 1967
- Language: English
- Type: text , Article
- Identifier: vital:6370 , http://hdl.handle.net/10962/d1006072
- Description: A series of amine complexes has been prepared by reaction of zinc chloride and mercuric chloride with primary aromatic amines. A detailed assignment of the bands in the infra-red spectra of the complexes in the range 4000-625 cm [superscript]-1 is presented. The symmetric and asymmetric N-H stretching frequencies follow the relationship v(sym) = 345.5+ 0.876v(asym). The C-N stretching frequencies exhibit a linear relationship with the Hammett α-functions for the m- and p-substituted amines.
- Full Text:
- Date Issued: 1967