Age validation, growth, mortality, and demographic modeling of spotted gully shark (Triakis megalopterus) from the southeast coast of South Africa
- Booth, Anthony J, Foulis, Alan J, Smale, Malcolm J
- Authors: Booth, Anthony J , Foulis, Alan J , Smale, Malcolm J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123630 , vital:35466 , https://spo.nmfs.noaa.gov/sites/default/files/pdf-content/2011/1091/booth.pdf
- Description: This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and f luoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0= –2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate.
- Full Text:
- Date Issued: 2011
- Authors: Booth, Anthony J , Foulis, Alan J , Smale, Malcolm J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123630 , vital:35466 , https://spo.nmfs.noaa.gov/sites/default/files/pdf-content/2011/1091/booth.pdf
- Description: This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and f luoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0= –2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate.
- Full Text:
- Date Issued: 2011
In service to the law: Alastair James Kerr SC
- Authors: Glover, Graham B
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70658 , vital:29686 , https://hdl.handle.net/10520/EJC53959
- Description: Professor Alastair James Kerr SC passed away at Settlers Hospital in Grahamstown on the 29th of September 2010. He was eighty-eight years of age. Ironically, his death occurred at the time that the third part of the 2010 SALJ appeared in print, containing a tribute to one of the other great writers on South African contract law, Professor Richard (Dick) Christie, who had passed away earlier in the year (see A J G Lang 'Professor Richard Hunter Christie: A memorial tribute' (2010) 127 SALJ 414). 2010 may have been a momentous year in South Africa for many reasons, but the deaths of these two men in the same year has left the landscape of our contract law irrevocably changed, even though their ideas will live on through their published works.
- Full Text: false
- Date Issued: 2011
- Authors: Glover, Graham B
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70658 , vital:29686 , https://hdl.handle.net/10520/EJC53959
- Description: Professor Alastair James Kerr SC passed away at Settlers Hospital in Grahamstown on the 29th of September 2010. He was eighty-eight years of age. Ironically, his death occurred at the time that the third part of the 2010 SALJ appeared in print, containing a tribute to one of the other great writers on South African contract law, Professor Richard (Dick) Christie, who had passed away earlier in the year (see A J G Lang 'Professor Richard Hunter Christie: A memorial tribute' (2010) 127 SALJ 414). 2010 may have been a momentous year in South Africa for many reasons, but the deaths of these two men in the same year has left the landscape of our contract law irrevocably changed, even though their ideas will live on through their published works.
- Full Text: false
- Date Issued: 2011
Cultural importance of non-timber forest products: opportunities they pose for bio-cultural diversity in dynamic societies
- Cocks, Michelle L, López, Citlalli, Dold, Anthony P
- Authors: Cocks, Michelle L , López, Citlalli , Dold, Anthony P
- Date: 2011
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/141453 , vital:37973 , ISBN 9783642179822 , DOI: 10.1007/978-3-642-17983-9_5
- Description: There is an increasing awareness that monetary value does not fully represent the complete value and significance of NTFPs. Consequently, there is growing interest in the cultural dimensions of biodiversity and the role that it plays in human well-being. This chapter presents two case studies, one on traditional brooms in South Africa, and the other on amate paper in Mexico, to demonstrate the importance of cultural values on driving demand for NTFPs. Because cultural values are so deeply embedded, the demand for culturally valued NTFPs continue across the rural-urban divide, and are maintained even by modernising urban communities. This poses particular challenges, not only for conservation of the NTFPs, but also to sustain cultural diversity in a rapidly changing world.
- Full Text:
- Date Issued: 2011
- Authors: Cocks, Michelle L , López, Citlalli , Dold, Anthony P
- Date: 2011
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/141453 , vital:37973 , ISBN 9783642179822 , DOI: 10.1007/978-3-642-17983-9_5
- Description: There is an increasing awareness that monetary value does not fully represent the complete value and significance of NTFPs. Consequently, there is growing interest in the cultural dimensions of biodiversity and the role that it plays in human well-being. This chapter presents two case studies, one on traditional brooms in South Africa, and the other on amate paper in Mexico, to demonstrate the importance of cultural values on driving demand for NTFPs. Because cultural values are so deeply embedded, the demand for culturally valued NTFPs continue across the rural-urban divide, and are maintained even by modernising urban communities. This poses particular challenges, not only for conservation of the NTFPs, but also to sustain cultural diversity in a rapidly changing world.
- Full Text:
- Date Issued: 2011
Comparative structural bioinformatics analysis of Bacillus amyloliquefaciens chemotaxis proteins within Bacillus subtilis group
- Yssel, Anna, Reva, Oleg, Tastan Bishop, Özlem
- Authors: Yssel, Anna , Reva, Oleg , Tastan Bishop, Özlem
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123966 , vital:35521 , https://doi.10.1007/s00253-011-3582-y
- Description: Chemotaxis is a process in which bacteria sense their chemical environment and move towards more favorable conditions. Since plant colonization by bacteria is a multifaceted process which requires a response to the complex chemical environment, a finely tuned and sensitive chemotaxis system is needed. Members of the Bacillus subtilis group including Bacillus amyloliquefaciens are industrially important, for example, as bio-pesticides. The group exhibits plant growth-promoting characteristics, with different specificity towards certain host plants. Therefore, we hypothesize that while the principal molecular mechanisms of bacterial chemotaxis may be conserved, the bacterial chemotaxis system may need an evolutionary tweaking to adapt it to specific requirements, particularly in the process of evolution of free-living soil organisms, towards plant colonization behaviour. To date, almost nothing is known about what parts of the chemotaxis proteins are subjected to positive amino acid substitutions, involved in adjusting the chemotaxis system of bacteria during speciation. In this novel study, positively selected and purified sites of chemotaxis proteins were calculated, and these residues were mapped onto homology models that were built for the chemotaxis proteins, in an attempt to understand the spatial evolution of the chemotaxis proteins. Various positively selected amino acids were identified in semi-conserved regions of the proteins away from the known active sites.
- Full Text:
- Date Issued: 2011
- Authors: Yssel, Anna , Reva, Oleg , Tastan Bishop, Özlem
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123966 , vital:35521 , https://doi.10.1007/s00253-011-3582-y
- Description: Chemotaxis is a process in which bacteria sense their chemical environment and move towards more favorable conditions. Since plant colonization by bacteria is a multifaceted process which requires a response to the complex chemical environment, a finely tuned and sensitive chemotaxis system is needed. Members of the Bacillus subtilis group including Bacillus amyloliquefaciens are industrially important, for example, as bio-pesticides. The group exhibits plant growth-promoting characteristics, with different specificity towards certain host plants. Therefore, we hypothesize that while the principal molecular mechanisms of bacterial chemotaxis may be conserved, the bacterial chemotaxis system may need an evolutionary tweaking to adapt it to specific requirements, particularly in the process of evolution of free-living soil organisms, towards plant colonization behaviour. To date, almost nothing is known about what parts of the chemotaxis proteins are subjected to positive amino acid substitutions, involved in adjusting the chemotaxis system of bacteria during speciation. In this novel study, positively selected and purified sites of chemotaxis proteins were calculated, and these residues were mapped onto homology models that were built for the chemotaxis proteins, in an attempt to understand the spatial evolution of the chemotaxis proteins. Various positively selected amino acids were identified in semi-conserved regions of the proteins away from the known active sites.
- Full Text:
- Date Issued: 2011
Developing visual images for communicating information aboutantiretroviral side effects to a low-literate population:
- Dowse, Roslind, Ramela, Thato, Barford, Kirsty-Lee, Browne, Sara H
- Authors: Dowse, Roslind , Ramela, Thato , Barford, Kirsty-Lee , Browne, Sara H
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156769 , vital:40048 , https://doi.org/10.2989/16085906.2010.530172
- Description: The side effects of antiretroviral (ARV) therapy are linked to altered quality of life and adherence. Poor adherence has also been associated with low health-literacy skills, with an uninformed patient more likely to make ARV-related decisions that compromise the efficacy of the treatment. Low literacy skills disempower patients in interactions with healthcare providers and preclude the use of existing written patient information materials, which are generally written at a high reading level. Visual images or pictograms used as a counselling tool or included in patient information leaflets have been shown to improve patients’ knowledge, particularly in low-literate groups. The objective of this study was to design visuals or pictograms illustrating various ARV side effects and to evaluate them in a low-literate South African Xhosa population. Core images were generated either from a design workshop or from posed photos or images from textbooks. The research team worked closely with a graphic artist. Initial versions of the images were discussed and assessed in group discussions, and then modified and eventually evaluated quantitatively in individual interviews with 40 participants who each had a maximum of 10 years of schooling.
- Full Text:
- Date Issued: 2011
- Authors: Dowse, Roslind , Ramela, Thato , Barford, Kirsty-Lee , Browne, Sara H
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156769 , vital:40048 , https://doi.org/10.2989/16085906.2010.530172
- Description: The side effects of antiretroviral (ARV) therapy are linked to altered quality of life and adherence. Poor adherence has also been associated with low health-literacy skills, with an uninformed patient more likely to make ARV-related decisions that compromise the efficacy of the treatment. Low literacy skills disempower patients in interactions with healthcare providers and preclude the use of existing written patient information materials, which are generally written at a high reading level. Visual images or pictograms used as a counselling tool or included in patient information leaflets have been shown to improve patients’ knowledge, particularly in low-literate groups. The objective of this study was to design visuals or pictograms illustrating various ARV side effects and to evaluate them in a low-literate South African Xhosa population. Core images were generated either from a design workshop or from posed photos or images from textbooks. The research team worked closely with a graphic artist. Initial versions of the images were discussed and assessed in group discussions, and then modified and eventually evaluated quantitatively in individual interviews with 40 participants who each had a maximum of 10 years of schooling.
- Full Text:
- Date Issued: 2011
Report on the Mesozoic volcanic and intrusive rocks on the Namibe Basin, Southwest Angola:
- Authors: Marsh, Julian S
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144846 , vital:38384
- Description: The Bero Volcanic Complex comprises a diverse group of quartz latite and tholeiitic basalt lavas, pyroclastic and volcaniclastic deposits, aeolian sandstones as well as intrusive tholeiitic mafic dykes and gabbros. Only the silicic members of this suite have received prior attention being referred to as “granitic porphyries” by Carvalho (1961) who regarded them as being Precambrian in age. Alberti et al.(1992) informally referred to these silicic rocks as the ‘Giraul Volcanics’ and correlated them with the early Cretaceous Paraná-Etendeka Igneous Province of Brazil and Namibia.
- Full Text:
- Date Issued: 2011
- Authors: Marsh, Julian S
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144846 , vital:38384
- Description: The Bero Volcanic Complex comprises a diverse group of quartz latite and tholeiitic basalt lavas, pyroclastic and volcaniclastic deposits, aeolian sandstones as well as intrusive tholeiitic mafic dykes and gabbros. Only the silicic members of this suite have received prior attention being referred to as “granitic porphyries” by Carvalho (1961) who regarded them as being Precambrian in age. Alberti et al.(1992) informally referred to these silicic rocks as the ‘Giraul Volcanics’ and correlated them with the early Cretaceous Paraná-Etendeka Igneous Province of Brazil and Namibia.
- Full Text:
- Date Issued: 2011
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