Isomerization of the 2-Norbornyl Carbocation
- Authors: Lobb, Kevin A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447992 , vital:74689 , xlink:href="https://doi.org/10.1002/ejoc.201500518"
- Description: In order to elucidate the mechanism for the isomerization of the 2-norbornyl carbocation into its most stable isomer, the 1,3-dimethylcyclopentenyl carbocation, an extensive set of the possible isomers of C7H11+ has been generated. Each one of these may undergo a number of transformations, and location of these transition states provides a searchable graph, from which pathways may be identified. This reveals that the preferred route for isomerization of the 2-norbornyl carbocation is not by ring opening of the non-classical center as has been reported in the literature (with an activation energy of 33.2 kcal/mol), but is initiated by cleavage of the C3–C4 bond (23.5 kcal/mol). Further, no single mechanism is sufficient to describe the full sequence of isomerizations of the 2-norbornyl carbocation to its most stable isomer, the 1,3-dimethylcylcopentenyl carbocation, but rather a collection (> 109) of pathways.
- Full Text:
- Date Issued: 2015
- Authors: Lobb, Kevin A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447992 , vital:74689 , xlink:href="https://doi.org/10.1002/ejoc.201500518"
- Description: In order to elucidate the mechanism for the isomerization of the 2-norbornyl carbocation into its most stable isomer, the 1,3-dimethylcyclopentenyl carbocation, an extensive set of the possible isomers of C7H11+ has been generated. Each one of these may undergo a number of transformations, and location of these transition states provides a searchable graph, from which pathways may be identified. This reveals that the preferred route for isomerization of the 2-norbornyl carbocation is not by ring opening of the non-classical center as has been reported in the literature (with an activation energy of 33.2 kcal/mol), but is initiated by cleavage of the C3–C4 bond (23.5 kcal/mol). Further, no single mechanism is sufficient to describe the full sequence of isomerizations of the 2-norbornyl carbocation to its most stable isomer, the 1,3-dimethylcylcopentenyl carbocation, but rather a collection (> 109) of pathways.
- Full Text:
- Date Issued: 2015
Issues and concerns in developing regulated markets for endangered species products: the case of rhinoceros horns
- Collins, Alan, Fraser, Gavin C G, Snowball, Jeanette D
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124877 , vital:35706 , https://doi.org/10.1093/cje/bev076
- Description: A proposal for addressing rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach, overturning the current trade ban. This orthodox economic prescription aims to reduce incentives to poach endangered wildlife by driving down the market price of their products via auctioned stockpile releases. Biologists are clear, however, that securing a stockpile for some species needs biological success in captive breeding programmes (CBPs), which varies markedly across species and habitats. Rhinoceros herds in a CBP would need spatially extensive terrain and costly permanent security measures; this only appears feasible for the less aggressive ‘white’ rhino. We argue that the market price would actually need to be sustained at a high level to cover protection costs over the longer reproduction cycles in CBPs and that, without extensive monitoring and the correct institutional structures being in place, legalising trade may encourage, rather than prevent, poaching. Supplementary policy measures that differentiate among consumer groups would also likely prove necessary.
- Full Text:
- Date Issued: 2015
- Authors: Collins, Alan , Fraser, Gavin C G , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124877 , vital:35706 , https://doi.org/10.1093/cje/bev076
- Description: A proposal for addressing rhinoceros poaching is to legalise the trade in rhino horn and adopt a regulated market approach, overturning the current trade ban. This orthodox economic prescription aims to reduce incentives to poach endangered wildlife by driving down the market price of their products via auctioned stockpile releases. Biologists are clear, however, that securing a stockpile for some species needs biological success in captive breeding programmes (CBPs), which varies markedly across species and habitats. Rhinoceros herds in a CBP would need spatially extensive terrain and costly permanent security measures; this only appears feasible for the less aggressive ‘white’ rhino. We argue that the market price would actually need to be sustained at a high level to cover protection costs over the longer reproduction cycles in CBPs and that, without extensive monitoring and the correct institutional structures being in place, legalising trade may encourage, rather than prevent, poaching. Supplementary policy measures that differentiate among consumer groups would also likely prove necessary.
- Full Text:
- Date Issued: 2015
JMS: a workflow management system and web-based cluster front-end for the Torque resource manager
- Brown, David K, Musyoka, Thommas M, Penkler, David L, Tastan Bishop, Özlem
- Authors: Brown, David K , Musyoka, Thommas M , Penkler, David L , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148049 , vital:38705 , https://arxiv.org/abs/1501.06907
- Description: Complex computational pipelines are becoming a staple of modern scientific research. Often these pipelines are resource intensive and require days of computing time. In such cases, it makes sense to run them over distributed computer clusters where they can take advantage of the aggregated resources of many powerful computers. In addition to this, researchers often want to integrate their workflows into their own web servers. In these cases, software is needed to manage the submission of jobs from the web interface to the cluster and then return the results once the job has finished executing.
- Full Text:
- Date Issued: 2015
- Authors: Brown, David K , Musyoka, Thommas M , Penkler, David L , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148049 , vital:38705 , https://arxiv.org/abs/1501.06907
- Description: Complex computational pipelines are becoming a staple of modern scientific research. Often these pipelines are resource intensive and require days of computing time. In such cases, it makes sense to run them over distributed computer clusters where they can take advantage of the aggregated resources of many powerful computers. In addition to this, researchers often want to integrate their workflows into their own web servers. In these cases, software is needed to manage the submission of jobs from the web interface to the cluster and then return the results once the job has finished executing.
- Full Text:
- Date Issued: 2015
JMS: an open source workflow management system and web-based cluster front-end for high performance computing
- Brown, David K, Penkler, David L, Musyoka, Thommas M, Tastan Bishop, Özlem
- Authors: Brown, David K , Penkler, David L , Musyoka, Thommas M , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162880 , vital:40993 , doi:10.1371/journal.pone.0134273
- Description: Complex computational pipelines are becoming a staple of modern scientific research. Often these pipelines are resource intensive and require days of computing time. In such cases, it makes sense to run them over high performance computing (HPC) clusters where they can take advantage of the aggregated resources of many powerful computers. In addition to this, researchers often want to integrate their workflows into their own web servers. In these cases, software is needed to manage the submission of jobs from the web interface to the cluster and then return the results once the job has finished executing. We have developed the Job Management System (JMS), a workflow management system and web interface for high performance computing (HPC). JMS provides users with a user-friendly web interface for creating complex workflows with multiple stages. It integrates this workflow functionality with the resource manager, a tool that is used to control and manage batch jobs on HPC clusters. As such, JMS combines workflow management functionality with cluster administration functionality.
- Full Text:
- Date Issued: 2015
- Authors: Brown, David K , Penkler, David L , Musyoka, Thommas M , Tastan Bishop, Özlem
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162880 , vital:40993 , doi:10.1371/journal.pone.0134273
- Description: Complex computational pipelines are becoming a staple of modern scientific research. Often these pipelines are resource intensive and require days of computing time. In such cases, it makes sense to run them over high performance computing (HPC) clusters where they can take advantage of the aggregated resources of many powerful computers. In addition to this, researchers often want to integrate their workflows into their own web servers. In these cases, software is needed to manage the submission of jobs from the web interface to the cluster and then return the results once the job has finished executing. We have developed the Job Management System (JMS), a workflow management system and web interface for high performance computing (HPC). JMS provides users with a user-friendly web interface for creating complex workflows with multiple stages. It integrates this workflow functionality with the resource manager, a tool that is used to control and manage batch jobs on HPC clusters. As such, JMS combines workflow management functionality with cluster administration functionality.
- Full Text:
- Date Issued: 2015
Journalism students’ motivations and expectations of their work in comparative perspective:
- Hanusch, Folker, Mellado, Claudia, Boshoff, Priscilla A, Humanes, María Luisa, De León, Salvador, Pereira, Fabio, Márquez Ramírez, Mireya, Roses, Sergio, Subervi, Federico, Wyss, Vinzenz, Yez, Lyuba
- Authors: Hanusch, Folker , Mellado, Claudia , Boshoff, Priscilla A , Humanes, María Luisa , De León, Salvador , Pereira, Fabio , Márquez Ramírez, Mireya , Roses, Sergio , Subervi, Federico , Wyss, Vinzenz , Yez, Lyuba
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143425 , vital:38245 , DOI: 10.1177/1077695814554295
- Description: Based on a survey of 4,393 journalism students in Australia, Brazil, Chile, Mexico, South Africa, Spain, Switzerland, and the United States, this study provides much-needed comparative evidence about students’ motivations for becoming journalists, their future job plans, and expectations. Findings show not only an almost universal decline in students’ desire to work in journalism by the end of their program but also important national differences in terms of the journalistic fields in which they want to work, as well as their job expectations. The results reinforce the need to take into account national contexts when examining journalism education across the globe.
- Full Text:
- Date Issued: 2015
- Authors: Hanusch, Folker , Mellado, Claudia , Boshoff, Priscilla A , Humanes, María Luisa , De León, Salvador , Pereira, Fabio , Márquez Ramírez, Mireya , Roses, Sergio , Subervi, Federico , Wyss, Vinzenz , Yez, Lyuba
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143425 , vital:38245 , DOI: 10.1177/1077695814554295
- Description: Based on a survey of 4,393 journalism students in Australia, Brazil, Chile, Mexico, South Africa, Spain, Switzerland, and the United States, this study provides much-needed comparative evidence about students’ motivations for becoming journalists, their future job plans, and expectations. Findings show not only an almost universal decline in students’ desire to work in journalism by the end of their program but also important national differences in terms of the journalistic fields in which they want to work, as well as their job expectations. The results reinforce the need to take into account national contexts when examining journalism education across the globe.
- Full Text:
- Date Issued: 2015
Just saying “No” is not enough: a Foucauldian Discourse Analysis of anti-rape poster campaigns
- Böhmke, Werner, Bennie, Rachel, Minnie, Chantel, Moore, Sarah-Ann, Pilusa, Mikaylah, Pollock, James
- Authors: Böhmke, Werner , Bennie, Rachel , Minnie, Chantel , Moore, Sarah-Ann , Pilusa, Mikaylah , Pollock, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143727 , vital:38277 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Sexual violence is a serious social concern, especially in South Africa. Explanations for high levels of sexual violence often point to normative cultural expectations regarding gendered behaviour. Consequently, attempts to address sexual violence frequently take the form of public health initiatives aimed at increasing awareness of the problem, encouraging reporting and, much more recently, addressing the social attitudes believed to be held by perpetrators of this violence. A common format for such initiatives is anti-rape poster campaigns. This paper argues, through applying Foucauldian discourse analysis to a series of posters, that very often the messages conveyed by these initiatives are addressed at the prohibition of behaviours associated with sexual violence. The analysis shows that this strategy may not be sufficient, and instead argues that alternative strategies - aimed at inviting audiences to take up an ethical position - may be more effective at producing change.
- Full Text:
- Date Issued: 2015
- Authors: Böhmke, Werner , Bennie, Rachel , Minnie, Chantel , Moore, Sarah-Ann , Pilusa, Mikaylah , Pollock, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143727 , vital:38277 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Sexual violence is a serious social concern, especially in South Africa. Explanations for high levels of sexual violence often point to normative cultural expectations regarding gendered behaviour. Consequently, attempts to address sexual violence frequently take the form of public health initiatives aimed at increasing awareness of the problem, encouraging reporting and, much more recently, addressing the social attitudes believed to be held by perpetrators of this violence. A common format for such initiatives is anti-rape poster campaigns. This paper argues, through applying Foucauldian discourse analysis to a series of posters, that very often the messages conveyed by these initiatives are addressed at the prohibition of behaviours associated with sexual violence. The analysis shows that this strategy may not be sufficient, and instead argues that alternative strategies - aimed at inviting audiences to take up an ethical position - may be more effective at producing change.
- Full Text:
- Date Issued: 2015
Keeping food on the table: responses and changing coastal fisheries in Solomon Islands
- Albert, Simon, Aswani, Shankar, Fisher, Paul L, Albert, Joelle
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70593 , vital:29678 , https://doi.org/10.1371/journal.pone.0130800
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/ or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70593 , vital:29678 , https://doi.org/10.1371/journal.pone.0130800
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/ or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
Knowledge production about voluntary childlessness as a family form: a systematic review of trends
- Authors: Lynch, Ingrid
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143604 , vital:38266 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: There has been a steady increase in research concerned with non-traditional reproductive decision-making, including research investigating voluntarily childlessness. Existing reviews of this body of scholarship focus on dominant themes over time including: the demographic incidence of voluntary childlessness, different pathways to voluntary childlessness, motivations for being childfree, physical and mental health consequences of being childfree and stigmatisation of childfree individuals and responses to stigma. We extend previous systematic literature reviews to attend to sociohistorical and geopolitical aspects of knowledge production about voluntary childlessness. Our dataset comprised 195 peer-reviewed articles that were coded and analysed to explore inter alia the main topic under investigation, country context, sample characteristics and methodology. We discuss the findings in relation to the socio-historical contexts of knowledge production, highlighting implications for current understandings of families, reproductive decision-making and reproductive justice.
- Full Text:
- Date Issued: 2015
- Authors: Lynch, Ingrid
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143604 , vital:38266 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: There has been a steady increase in research concerned with non-traditional reproductive decision-making, including research investigating voluntarily childlessness. Existing reviews of this body of scholarship focus on dominant themes over time including: the demographic incidence of voluntary childlessness, different pathways to voluntary childlessness, motivations for being childfree, physical and mental health consequences of being childfree and stigmatisation of childfree individuals and responses to stigma. We extend previous systematic literature reviews to attend to sociohistorical and geopolitical aspects of knowledge production about voluntary childlessness. Our dataset comprised 195 peer-reviewed articles that were coded and analysed to explore inter alia the main topic under investigation, country context, sample characteristics and methodology. We discuss the findings in relation to the socio-historical contexts of knowledge production, highlighting implications for current understandings of families, reproductive decision-making and reproductive justice.
- Full Text:
- Date Issued: 2015
Local institutions, actors, and natural resource governance in Kgalagadi Transfrontier Park and surrounds, South Africa
- Thondhlana, Gladman, Shackleton, Sheona E, Blignaut, James
- Authors: Thondhlana, Gladman , Shackleton, Sheona E , Blignaut, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67689 , vital:29130 , https://doi.org/10.1016/j.landusepol.2015.03.013
- Description: Publisher version , Crafting local institutions to allow more effective decision-making in the management of and access to natural resources in and beyond parks has long been considered key to collaborative governance. South Africa, in particular, has vigorously pursued collaborative governance as a desired approach to managing natural resources as evident in the new arrangements for previously restricted parks. However, though the discourse of collaborative governance has occupied conservation thinking and practice globally, few studies have looked at the interplay between local institutions, actors and collaborative governance involving indigenous hunter–gatherer communities in Southern Africa. In response, we assess the local actors and institutions that were put in place to facilitate collaborative governance of natural resources in the Kgalagadi Transfrontier Park and its surrounds in South Africa. Our findings show that though collaborative governance has a practical appeal, it is hampered by lack of participation in decision-making, information dissemination, transparency, trust and accountability, power relations, divergent interests and unequal access to natural resources. The findings also draw our attention to issues of heterogeneity, even within indigenous communities assumed to be homogenous by local conservation authorities as reflected in land settlement agreements in co-managed parks. We argue that collaborative governance arrangements need to reflect and be understood within the broader background of complex local realities.
- Full Text: false
- Date Issued: 2015
- Authors: Thondhlana, Gladman , Shackleton, Sheona E , Blignaut, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67689 , vital:29130 , https://doi.org/10.1016/j.landusepol.2015.03.013
- Description: Publisher version , Crafting local institutions to allow more effective decision-making in the management of and access to natural resources in and beyond parks has long been considered key to collaborative governance. South Africa, in particular, has vigorously pursued collaborative governance as a desired approach to managing natural resources as evident in the new arrangements for previously restricted parks. However, though the discourse of collaborative governance has occupied conservation thinking and practice globally, few studies have looked at the interplay between local institutions, actors and collaborative governance involving indigenous hunter–gatherer communities in Southern Africa. In response, we assess the local actors and institutions that were put in place to facilitate collaborative governance of natural resources in the Kgalagadi Transfrontier Park and its surrounds in South Africa. Our findings show that though collaborative governance has a practical appeal, it is hampered by lack of participation in decision-making, information dissemination, transparency, trust and accountability, power relations, divergent interests and unequal access to natural resources. The findings also draw our attention to issues of heterogeneity, even within indigenous communities assumed to be homogenous by local conservation authorities as reflected in land settlement agreements in co-managed parks. We argue that collaborative governance arrangements need to reflect and be understood within the broader background of complex local realities.
- Full Text: false
- Date Issued: 2015
Local wood demand, land cover change and the state of Albany thicket on an urban commonage in the Eastern Cape, South Africa
- Stickler, M M, Shackleton, Charlie M
- Authors: Stickler, M M , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398343 , vital:69402 , xlink:href="https://doi.org/10.1007/s00267-014-0396-6"
- Description: Understanding the rates and causes of land-use change is crucial in identifying solutions, especially in sensitive landscapes and ecosystems, as well as in places undergoing rapid political, socioeconomic or ecological change. Despite considerable concern at the rate of transformation and degradation of the biodiversity-rich Albany Thicket biome in South Africa, most knowledge is gleaned from private commercial lands and state conservation areas. In comparison, there is limited work in communal areas where land uses include biomass extraction, especially for firewood and construction timber. We used aerial photographs to analyze land use and cover change in the high- and low-use zones of an urban commonage and an adjacent protected area over almost six decades, which included a major political transition. Field sampling was undertaken to characterize the current state of the vegetation and soils of the commonage and protected area and to determine the supply and demand for firewood and construction timber. Between the 1950s and 1980s, there was a clear increase in woody vegetation cover, which was reversed after the political transition in the mid-1990s. However, current woody plant standing stocks and sustainable annual production rates are well above current firewood demand, suggesting other probable causes for the decline in woody plant cover. The fragmentation of woody plant cover is paralleled by increases in grassy areas and bare ground, an increase in soil compaction, and decreases in soil moisture, carbon, and nutrients.
- Full Text:
- Date Issued: 2015
- Authors: Stickler, M M , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/398343 , vital:69402 , xlink:href="https://doi.org/10.1007/s00267-014-0396-6"
- Description: Understanding the rates and causes of land-use change is crucial in identifying solutions, especially in sensitive landscapes and ecosystems, as well as in places undergoing rapid political, socioeconomic or ecological change. Despite considerable concern at the rate of transformation and degradation of the biodiversity-rich Albany Thicket biome in South Africa, most knowledge is gleaned from private commercial lands and state conservation areas. In comparison, there is limited work in communal areas where land uses include biomass extraction, especially for firewood and construction timber. We used aerial photographs to analyze land use and cover change in the high- and low-use zones of an urban commonage and an adjacent protected area over almost six decades, which included a major political transition. Field sampling was undertaken to characterize the current state of the vegetation and soils of the commonage and protected area and to determine the supply and demand for firewood and construction timber. Between the 1950s and 1980s, there was a clear increase in woody vegetation cover, which was reversed after the political transition in the mid-1990s. However, current woody plant standing stocks and sustainable annual production rates are well above current firewood demand, suggesting other probable causes for the decline in woody plant cover. The fragmentation of woody plant cover is paralleled by increases in grassy areas and bare ground, an increase in soil compaction, and decreases in soil moisture, carbon, and nutrients.
- Full Text:
- Date Issued: 2015
Making media theory from the South:
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158873 , vital:40236 , https://doi.org/10.1080/23743670.2015.1008186
- Description: Like many other academics who have joined the digital age I have pages and uploads on Academia.edu, Researchgate, LinkedIn and a Google Scholar-aggregated thing (that seemed to trawl the net for my papers, do it for me and then invite me to view my own collection!). So, I get lots of email alerts telling me when someone has looked at my work and downloaded my papers. I appreciate this virtual community and enjoy participating in it, but the aspect of this that perplexes me is the need to ‘endorse’’ someone for their skills – a practice that seems to stem from LinkedIn’s businessmindedness aimed at youngsters trying to find a foothold on the career ladder. I don’t do endorsements unless the programme forces me to go through this step in order to do what I want to do on the site.
- Full Text:
- Date Issued: 2015
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158873 , vital:40236 , https://doi.org/10.1080/23743670.2015.1008186
- Description: Like many other academics who have joined the digital age I have pages and uploads on Academia.edu, Researchgate, LinkedIn and a Google Scholar-aggregated thing (that seemed to trawl the net for my papers, do it for me and then invite me to view my own collection!). So, I get lots of email alerts telling me when someone has looked at my work and downloaded my papers. I appreciate this virtual community and enjoy participating in it, but the aspect of this that perplexes me is the need to ‘endorse’’ someone for their skills – a practice that seems to stem from LinkedIn’s businessmindedness aimed at youngsters trying to find a foothold on the career ladder. I don’t do endorsements unless the programme forces me to go through this step in order to do what I want to do on the site.
- Full Text:
- Date Issued: 2015
Making rules to live by: Was the proposed regulatory regime for invasive species reasonable? Perceptions of the South African trout industry
- Marire, Juniours, Snowball, Jeanette D, Fraser, Gavin C G
- Authors: Marire, Juniours , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68566 , vital:29285 , http://2015.essa.org.za/fullpaper/essa_2938.pdf
- Description: Publisher version , Despite considerable economic impact of trout-based aquaculture and recreational fishing, the Department of Environmental Affairs has been focusing almost entirely on ecological criteria in deciding the regulatory regime for trout. We examined whether the proposed regulatory regime for alien and invasive species that was published by the Department of Environmental Affairs in 2014 for public comment was reasonable. The analysis produced factors that might matter in the design of reasonable institutional arrangements that impose a reasonable regulatory burden on economic sectors utilising invasive species. We conducted factor analysis using an online survey that we conducted between May and July 2014. We obtained four clusters of factors: participatory policymaking, people-centeredness, credible scientific evidence for listing species as invasive and contextualisation of international evidence. We then utilised the factors in a logistic regression framework to assess their influence on the probability of perceiving the regulations to be reasonable. The likelihood of a trout sector player perceiving the regulations to be reasonable was 1.2%. We found that a one standard deviation increase in the “credibility of scientific evidence” increased the odds of perceiving the regulations to be reasonable by 1645%. A one standard deviation increase in “participation” increased the odds of perceiving the regulations to be reasonable by 410%. A one standard deviation increase in “people-centeredness” increased the odds of perceiving the regulations to be reasonable by 600%. Lastly, a one standard deviation increase in the variable “contextualising international evidence” increased the odds of perceiving the regulations to be reasonable by 415%. This research demonstrates that properly addressing the socioeconomic aspects of new policies in addition to ecological criteria makes it far more likely that stakeholders will regard them as reasonable, even if the new policies impose increased regulatory transaction cost burden on users or reduced access to a resource.
- Full Text:
- Date Issued: 2015
- Authors: Marire, Juniours , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68566 , vital:29285 , http://2015.essa.org.za/fullpaper/essa_2938.pdf
- Description: Publisher version , Despite considerable economic impact of trout-based aquaculture and recreational fishing, the Department of Environmental Affairs has been focusing almost entirely on ecological criteria in deciding the regulatory regime for trout. We examined whether the proposed regulatory regime for alien and invasive species that was published by the Department of Environmental Affairs in 2014 for public comment was reasonable. The analysis produced factors that might matter in the design of reasonable institutional arrangements that impose a reasonable regulatory burden on economic sectors utilising invasive species. We conducted factor analysis using an online survey that we conducted between May and July 2014. We obtained four clusters of factors: participatory policymaking, people-centeredness, credible scientific evidence for listing species as invasive and contextualisation of international evidence. We then utilised the factors in a logistic regression framework to assess their influence on the probability of perceiving the regulations to be reasonable. The likelihood of a trout sector player perceiving the regulations to be reasonable was 1.2%. We found that a one standard deviation increase in the “credibility of scientific evidence” increased the odds of perceiving the regulations to be reasonable by 1645%. A one standard deviation increase in “participation” increased the odds of perceiving the regulations to be reasonable by 410%. A one standard deviation increase in “people-centeredness” increased the odds of perceiving the regulations to be reasonable by 600%. Lastly, a one standard deviation increase in the variable “contextualising international evidence” increased the odds of perceiving the regulations to be reasonable by 415%. This research demonstrates that properly addressing the socioeconomic aspects of new policies in addition to ecological criteria makes it far more likely that stakeholders will regard them as reasonable, even if the new policies impose increased regulatory transaction cost burden on users or reduced access to a resource.
- Full Text:
- Date Issued: 2015
Media framing of recent LGBT rights debates: the contrasting cases of South Africa, Uganda and the USA
- Authors: Dugmore, Harry
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143849 , vital:38288 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This paper compares key moments in the debates about LGBT rights, and the media coverage related to these key moments, in South Africa, Uganda and the USA. No country permitted same-sex marriage by the turn of millennium in 2000. Today, 15 countries do, as do two-thirds of states in the USA. By contrast, in some African countries, legislative regimes and social attitudes are shifting retrogressively, with the introduction of punitive laws against both ‘homosexual acts’ and the ‘promotion’ of same-sex relationships. While the drivers of progressive shifts in liberal democracies - such as LGBT activism, the impact of AIDS, and changes in the stances of professional health organisations - have also been at least partially present in many African countries, it is puzzling why these factors have not prevented an increase in repression in many African countries. As this paper outlines, the new laws have had immediate and dire impacts on the health of LGBT communities in the affected countries.
- Full Text:
- Date Issued: 2015
- Authors: Dugmore, Harry
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143849 , vital:38288 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This paper compares key moments in the debates about LGBT rights, and the media coverage related to these key moments, in South Africa, Uganda and the USA. No country permitted same-sex marriage by the turn of millennium in 2000. Today, 15 countries do, as do two-thirds of states in the USA. By contrast, in some African countries, legislative regimes and social attitudes are shifting retrogressively, with the introduction of punitive laws against both ‘homosexual acts’ and the ‘promotion’ of same-sex relationships. While the drivers of progressive shifts in liberal democracies - such as LGBT activism, the impact of AIDS, and changes in the stances of professional health organisations - have also been at least partially present in many African countries, it is puzzling why these factors have not prevented an increase in repression in many African countries. As this paper outlines, the new laws have had immediate and dire impacts on the health of LGBT communities in the affected countries.
- Full Text:
- Date Issued: 2015
Medical practitioners and conscientious objection to the provision of termination of pregnancy services:
- Chiwandire, Desire, Vincent, Louise
- Authors: Chiwandire, Desire , Vincent, Louise
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143838 , vital:38287 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: The 1996 Choice on Termination of Pregnancy Act decriminalized abortion in South Africa and the South African Medicines Control Council in 2000 approved the dispensing of emergency contraceptive methods by pharmacists to women without a doctor’s prescription. This legislation has been hailed as among the most progressive in the world with respect to women’s reproductive justice. However, the realization of these rights in practice has not always met expectations, in part due to medical practitioners’ ethical objections to termination of pregnancy and the provision of related services. The aim of this study was to interpret the varying ways in which medical practitioners frame termination of pregnancy services, their own professional identities and that of their patients/clients. A Sample of 58 doctors and 59 pharmacists were drawn from all nine provinces of South Africa. Data were collected using an anonymous confidential internet-based self-administered questionnaire. Participants were randomly recruited from online listings of South African doctors and pharmacists practicing in both private and public sectors. Data were analysed using theoretically derived qualitative content analysis.
- Full Text:
- Date Issued: 2015
- Authors: Chiwandire, Desire , Vincent, Louise
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143838 , vital:38287 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: The 1996 Choice on Termination of Pregnancy Act decriminalized abortion in South Africa and the South African Medicines Control Council in 2000 approved the dispensing of emergency contraceptive methods by pharmacists to women without a doctor’s prescription. This legislation has been hailed as among the most progressive in the world with respect to women’s reproductive justice. However, the realization of these rights in practice has not always met expectations, in part due to medical practitioners’ ethical objections to termination of pregnancy and the provision of related services. The aim of this study was to interpret the varying ways in which medical practitioners frame termination of pregnancy services, their own professional identities and that of their patients/clients. A Sample of 58 doctors and 59 pharmacists were drawn from all nine provinces of South Africa. Data were collected using an anonymous confidential internet-based self-administered questionnaire. Participants were randomly recruited from online listings of South African doctors and pharmacists practicing in both private and public sectors. Data were analysed using theoretically derived qualitative content analysis.
- Full Text:
- Date Issued: 2015
Meso-and axially-modified IrIIItriarylcorroles with tunable electrocatalytic properties
- Zhang, Xifeng, Wang, Yu, Zhu, Weihua, Mack, John, Soy, Rodah C, Nyokong, Tebello, Liang, Xu
- Authors: Zhang, Xifeng , Wang, Yu , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190851 , vital:45034 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: The synthesis of three A2B type Ir(III)triarylcorroles with meso-aryl substituents that provide electron donating (push) and withdrawing (pull) properties and three A3 type IrIIItriphenylcorroles with differing pyridine axial ligands is reported, along with their structural characterization. An analysis of the structure-property relationships in the optical and redox properties has been carried out by comparing their optical spectroscopy and electrochemistry to trends predicted in DFT and TD-DFT calculations. The results demonstrate that A2B type IrIIItriarylcorroles are highly efficient electrocatalyzed oxygen reduction reactions (ORRs) and that their reactivity can be modulated by modulating the electronic structure by changing the nature of the meso-substituent at the B-positions, and even axial pyridine ligands.
- Full Text:
- Date Issued: 2015
- Authors: Zhang, Xifeng , Wang, Yu , Zhu, Weihua , Mack, John , Soy, Rodah C , Nyokong, Tebello , Liang, Xu
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190851 , vital:45034 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: The synthesis of three A2B type Ir(III)triarylcorroles with meso-aryl substituents that provide electron donating (push) and withdrawing (pull) properties and three A3 type IrIIItriphenylcorroles with differing pyridine axial ligands is reported, along with their structural characterization. An analysis of the structure-property relationships in the optical and redox properties has been carried out by comparing their optical spectroscopy and electrochemistry to trends predicted in DFT and TD-DFT calculations. The results demonstrate that A2B type IrIIItriarylcorroles are highly efficient electrocatalyzed oxygen reduction reactions (ORRs) and that their reactivity can be modulated by modulating the electronic structure by changing the nature of the meso-substituent at the B-positions, and even axial pyridine ligands.
- Full Text:
- Date Issued: 2015
Microbial water quality of treated water and raw water sources in the Harare area, Zimbabwe
- Chirenda, Tatenda G, Srinivas, Sunitha C, Tandlich, Roman
- Authors: Chirenda, Tatenda G , Srinivas, Sunitha C , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76206 , vital:30520 , http://dx.doi.org/10.4314/wsa.v41i5.12
- Description: Microbial water quality is an essential aspect in the provision of potable water for domestic use. The provision of adequate amounts of safe water for domestic purposes has become difficult for most municipalities mandated to do so in Zimbabwe. Morton-Jaffray Treatment Plant supplies potable water to Harare City and areas surrounding Harare. This study investigated microbial water quality and the impact of microbial water quality related disasters in the area supplied by the Morton Jaffray Treatment Plant. Questionnaires were distributed to household owners in Harare who receive their water from the Municipality and those who use alternate water supplies. Candidates were randomly selected from their workplace. The raw water quality of Manyame River and its tributaries was assessed. Treated water in households was assessed for microbial quality using hydrogen sulphide test and heterotrophic bacteria plate count. Raw water sources were found to be contaminated by faecal matter. Household water sources tested negative for faecal contamination but positive for heterotrophic bacteria. CFU quantities ranged from 1 to 452 CFU/m. for all samples. The WHO guidelines for domestic water sources state that water used for domestic purposes should not be contain than 100 CFU/m.. Public perceptions of water quality ranged from eunsafef to ehighly contaminatedf. A decrease in the level of aesthetic appeal resulted in residents resorting to alternative sources such as wells and rivers for their domestic water. The current state of treated water was suitable for domestic use. Pathogen monitoring of domestic water is recommended using the hydrogen sulphide test and R2A agar test.
- Full Text:
- Date Issued: 2015
- Authors: Chirenda, Tatenda G , Srinivas, Sunitha C , Tandlich, Roman
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76206 , vital:30520 , http://dx.doi.org/10.4314/wsa.v41i5.12
- Description: Microbial water quality is an essential aspect in the provision of potable water for domestic use. The provision of adequate amounts of safe water for domestic purposes has become difficult for most municipalities mandated to do so in Zimbabwe. Morton-Jaffray Treatment Plant supplies potable water to Harare City and areas surrounding Harare. This study investigated microbial water quality and the impact of microbial water quality related disasters in the area supplied by the Morton Jaffray Treatment Plant. Questionnaires were distributed to household owners in Harare who receive their water from the Municipality and those who use alternate water supplies. Candidates were randomly selected from their workplace. The raw water quality of Manyame River and its tributaries was assessed. Treated water in households was assessed for microbial quality using hydrogen sulphide test and heterotrophic bacteria plate count. Raw water sources were found to be contaminated by faecal matter. Household water sources tested negative for faecal contamination but positive for heterotrophic bacteria. CFU quantities ranged from 1 to 452 CFU/m. for all samples. The WHO guidelines for domestic water sources state that water used for domestic purposes should not be contain than 100 CFU/m.. Public perceptions of water quality ranged from eunsafef to ehighly contaminatedf. A decrease in the level of aesthetic appeal resulted in residents resorting to alternative sources such as wells and rivers for their domestic water. The current state of treated water was suitable for domestic use. Pathogen monitoring of domestic water is recommended using the hydrogen sulphide test and R2A agar test.
- Full Text:
- Date Issued: 2015
Mips2C: programming from the machine up
- Authors: Machanick, Philip
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439226 , vital:73557 , https://homes.cs.ru.ac.za/philip/Courses/CS2-arch-C/Cs2MIPS2C.pdf
- Description: WHY THIS BOOK? Some years ago I took part in a panel discussion titled “Programming Early Considered Harmful” at the SIGCSE 2001 conference [Hitchner et al. 2001]. Once of those present was Yale Patt, whom I had met briefly on a sabbatical at University of Michigan, where he was at the time a professor working in computer architecture. His role on the panel was to proselytise his book, Introduction to Computing Systems: From bits and gates to C and beyond [Patt and Patel 2013], which introduced programming from the low level up. I found the idea intriguing particularly as I also was concerned with the problem that students tend to stick with the first thing they learn. If my concern was correct, it should be better to start with the programming model you want them to internalize, rather than start with machine level programming. Nonenetheless, I am always open to new ideas, and when the opportunity presented itself to run a computer organization course followed by a C course, I decided to try the idea for myself.
- Full Text:
- Date Issued: 2015
- Authors: Machanick, Philip
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439226 , vital:73557 , https://homes.cs.ru.ac.za/philip/Courses/CS2-arch-C/Cs2MIPS2C.pdf
- Description: WHY THIS BOOK? Some years ago I took part in a panel discussion titled “Programming Early Considered Harmful” at the SIGCSE 2001 conference [Hitchner et al. 2001]. Once of those present was Yale Patt, whom I had met briefly on a sabbatical at University of Michigan, where he was at the time a professor working in computer architecture. His role on the panel was to proselytise his book, Introduction to Computing Systems: From bits and gates to C and beyond [Patt and Patel 2013], which introduced programming from the low level up. I found the idea intriguing particularly as I also was concerned with the problem that students tend to stick with the first thing they learn. If my concern was correct, it should be better to start with the programming model you want them to internalize, rather than start with machine level programming. Nonenetheless, I am always open to new ideas, and when the opportunity presented itself to run a computer organization course followed by a C course, I decided to try the idea for myself.
- Full Text:
- Date Issued: 2015
Mitochondrial STAT3 and reactive oxygen species: a fulcrum of adipogenesis?
- Kramer, Adam H, Kadye, Rose, Houseman, Pascalene S, Prinsloo, Earl
- Authors: Kramer, Adam H , Kadye, Rose , Houseman, Pascalene S , Prinsloo, Earl
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431674 , vital:72795 , xlink:href="https://doi.org/10.1080/21623996.2015.1084084"
- Description: The balance between cellular lineages can be controlled by reactive oxygen species (ROS). Cellular differentiation into adipocytes is highly dependent on the production of ROS to initiate the process through activation of multiple interlinked factors that stimulate mitotic clonal expansion and cellular maturation. The signal transducer and activator of transcription family of signaling proteins have accepted roles in adipogenesis and associated lipogenesis. Non-canonical mitochondrial localization of STAT3 and other members of the STAT family however opens up new avenues for investigation of its role in the aforementioned processes. Following recent observations of differences in mitochondrially localized serine 727 phosphorylated STAT3 (mtSTAT3-pS727) in preadipocytes and adipocytes, here, we hypothesize and speculate further on the role of mitochondrial STAT3 in adipogenesis.
- Full Text:
- Date Issued: 2015
- Authors: Kramer, Adam H , Kadye, Rose , Houseman, Pascalene S , Prinsloo, Earl
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431674 , vital:72795 , xlink:href="https://doi.org/10.1080/21623996.2015.1084084"
- Description: The balance between cellular lineages can be controlled by reactive oxygen species (ROS). Cellular differentiation into adipocytes is highly dependent on the production of ROS to initiate the process through activation of multiple interlinked factors that stimulate mitotic clonal expansion and cellular maturation. The signal transducer and activator of transcription family of signaling proteins have accepted roles in adipogenesis and associated lipogenesis. Non-canonical mitochondrial localization of STAT3 and other members of the STAT family however opens up new avenues for investigation of its role in the aforementioned processes. Following recent observations of differences in mitochondrially localized serine 727 phosphorylated STAT3 (mtSTAT3-pS727) in preadipocytes and adipocytes, here, we hypothesize and speculate further on the role of mitochondrial STAT3 in adipogenesis.
- Full Text:
- Date Issued: 2015
Modelling stock return volatility dynamics in selected African markets
- Authors: King, Daniel , Botha, Ferdi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396104 , vital:69150 , xlink:href=" https://doi.org/10.1016/j.econmod.2014.11.008"
- Description: This paper examines whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002–2012. In the univariate portion of the paper, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. Accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important in capturing heteroscedasticity. However, those univariate models including a GARCH term perform comparatively poorly when used for forecasting purposes. In the multivariate study, the use of Markov-switching variance–covariance estimates improves risk-adjusted portfolio returns relative to portfolios constructed using the more conventional single-state models. While there is evidence that some Markov-switching models can provide better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture heteroscedasticity in the data remains problematic.
- Full Text:
- Date Issued: 2015
- Authors: King, Daniel , Botha, Ferdi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396104 , vital:69150 , xlink:href=" https://doi.org/10.1016/j.econmod.2014.11.008"
- Description: This paper examines whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002–2012. In the univariate portion of the paper, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. Accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important in capturing heteroscedasticity. However, those univariate models including a GARCH term perform comparatively poorly when used for forecasting purposes. In the multivariate study, the use of Markov-switching variance–covariance estimates improves risk-adjusted portfolio returns relative to portfolios constructed using the more conventional single-state models. While there is evidence that some Markov-switching models can provide better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture heteroscedasticity in the data remains problematic.
- Full Text:
- Date Issued: 2015
Morphologically similar, coexisting hard corals (Porites lobata and P. solida) display similar trophic isotopic ratios across reefs and depths
- Plass-Johnson, Jeremiah G, McQuaid, Christopher D, Hill, Jaclyn M
- Authors: Plass-Johnson, Jeremiah G , McQuaid, Christopher D , Hill, Jaclyn M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444598 , vital:74253 , https://doi.org/10.1071/MF14248
- Description: Recent studies using stable isotope analysis in scleractinian corals have highlighted strong inter- and intra-specific variability in isotopic ratios, but few have excluded the effects of morphology, which affects resource acquisition, potentially confounding this with metabolic differences among species. Differences in the stable isotopic (δ13C and δ15N) ratios of the coral host tissue and photosymbionts of two co-existing, morphologically similar Porites corals (P. lobata and P. solida) were examined across nested spatial scales (inter-reefs and intra-reef) and across depths in Zanzibar, Tanzania. There were few differences between species in either coral host or photosymbiont isotopic ratios, but the two tissues showed different spatial patterns. Photosymbionts showed variation only in their δ13C ratios, which differed among reefs, but not by depth. In contrast, the coral hosts differed in δ13C and δ15N values among reefs and also by depth. Within-reef differences among sites occurred only for photosymbionts at one reef. The absence of differences in isotopic ratios between the two Porites species across reefs and depths, confirms that highly related and morphologically similar scleractinian corals may occupy similar ecosystem niches, metabolising resources in a similar fashion. This suggests that resource partitioning among corals, and subsequent isotopic variability, is most likely driven by resource acquisition, rather than being inherently species-specific.
- Full Text:
- Date Issued: 2015
- Authors: Plass-Johnson, Jeremiah G , McQuaid, Christopher D , Hill, Jaclyn M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444598 , vital:74253 , https://doi.org/10.1071/MF14248
- Description: Recent studies using stable isotope analysis in scleractinian corals have highlighted strong inter- and intra-specific variability in isotopic ratios, but few have excluded the effects of morphology, which affects resource acquisition, potentially confounding this with metabolic differences among species. Differences in the stable isotopic (δ13C and δ15N) ratios of the coral host tissue and photosymbionts of two co-existing, morphologically similar Porites corals (P. lobata and P. solida) were examined across nested spatial scales (inter-reefs and intra-reef) and across depths in Zanzibar, Tanzania. There were few differences between species in either coral host or photosymbiont isotopic ratios, but the two tissues showed different spatial patterns. Photosymbionts showed variation only in their δ13C ratios, which differed among reefs, but not by depth. In contrast, the coral hosts differed in δ13C and δ15N values among reefs and also by depth. Within-reef differences among sites occurred only for photosymbionts at one reef. The absence of differences in isotopic ratios between the two Porites species across reefs and depths, confirms that highly related and morphologically similar scleractinian corals may occupy similar ecosystem niches, metabolising resources in a similar fashion. This suggests that resource partitioning among corals, and subsequent isotopic variability, is most likely driven by resource acquisition, rather than being inherently species-specific.
- Full Text:
- Date Issued: 2015