Associations in ephemeral systems: the lack of trophic relationships between sandhoppers and beach wrack
- Authors: Porri, Francesca , Hill, Jaclyn M , McQuaid, Christopher D
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444552 , vital:74250 , https://doi.org/10.3354/meps08951
- Description: In ephemeral systems, material subsidies can play a key role in the persistence and connectivity of populations, especially if the organisms living within them are trophically dependent on imported resources. Sandy beaches are heavily subsidized by organic material of both terrestrial and marine origin. For highly mobile supratidal fringe species, such as amphipods, which are marine but with a high tolerance of aerial conditions, such material potentially provides both food and shelter. We investigated the relationship between beach wrack and amphipods by examining the trophic contribution of allochthonous food sources to sandhopper diets using stable isotope analysis. Replicate samples of the sandhopper Talorchestia capensis and several types of beach wrack (including seagrass, wood and different macrophytes) colonized by these amphipods were collected from 11 sites within one biogeographical region along the south coast of South Africa.
- Full Text:
- Date Issued: 2011
Regulation and risk assessment for importations and releases of biological control agents against invasive alien plants in South Africa
- Authors: Klein, Hildegard , Hill, Martin P , Zachariades, Costas , Zimmermann, Helmuth G
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451481 , vital:75052 , https://hdl.handle.net/10520/EJC32898
- Description: The importation and release of biological control agents against invasive alien plants in South Africa are subject to regulation by the Department of Agriculture, Forestry and Fisheries (DAFF), under its Agricultural Pests Act, and by the Department of Environmental Affairs (DEA), initially under its Environment Conservation Act, subsequently under the National Environmental Management Act and eventually, as soon as the relevant regulations have been developed, under the National Environmental Management: Biodiversity Act. Peer review, both within South Africa, and with colleagues in other countries, has helped to ensure the integrity of the science and practice of weed biological control in South Africa. This paper traces the development of the regulatory system from the first weed biological control project in 1913, through a dispensation when importations and releases were authorized by DAFF only to a dual regulatory system involving two government departments. Inappropriate legislation, lack of knowledge about biological control amongst the relevant authorities and the costs of employing compulsory private consultants are some of the reasons for significant delays that have become a feature in the authorization of biological control agent releases. These delays have set back several control programmes. Holding agents in quarantine while awaiting decisions ties up expensive space and staff time and increases the risk of losing colonies through accidents or decreased genetic vigour. It seems likely that changes in legislation within DEA will streamline the regulatory process in the near future.
- Full Text:
- Date Issued: 2011
Rhodes University Library Annual Report 2010: Library Director’s Review
- Authors: Thomas, G M E
- Date: 2011
- Language: English
- Type: Text
- Identifier: vital:7943 , http://hdl.handle.net/10962/d1011890
- Description: [From the Introduction] 2010 was a momentous year for the Library, and for the University, with the new section of the Library being opened to users on 29 January and culminating in the official opening of the building on 4 November. This brought to conclusion the Library Building Project, an extension and refurbishment of the existing building, with building work beginning on 8 September 2008.
- Full Text:
- Date Issued: 2011
Study of protein complexes via homology modeling, applied to cysteine proteases and their protein inhibitors:
- Authors: Tastan Bishop, Özlem , Kroon, Matthys
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148070 , vital:38707 , DOI: 10.1007/s00894-011-0990-y
- Description: This paper develops and evaluates large-scale calculation of 3D structures of protein complexes by homology modeling as a promising new approach for protein docking. The complexes investigated were papain-like cysteine proteases and their protein inhibitors, which play numerous roles in human and parasitic metabolisms. The structural modeling was performed in two parts. For the first part (evaluation set), nine crystal structure complexes were selected, 1325 homology models of known complexes were rebuilt by various templates including hybrids, allowing an analysis of the factors influencing the accuracy of the models. The important considerations for modeling the interface were protease coverage and inhibitor sequence identity. In the second part (study set), the findings of the evaluation set were used to select appropriate templates to model novel cysteine protease-inhibitor complexes from human and malaria parasites Plasmodium falciparum and Plasmodium vivax. The energy scores, considering the evaluation set, indicate that the models are of high accuracy.
- Full Text:
- Date Issued: 2011
The future of e-Service provision in Marginalised Areas: Online Negotiation.
- Authors: Jere, Norbert R , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431332 , vital:72765 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=5d49a8014f769a529d821556ad204f1b25a97dcb#page=245
- Description: As the amount of commercial transactions carried out on t he Internet in-creases, the interest to partially or totally automate the negotiation of the terms of these transactions has rapidly become an interesting research topic. Several e-marketing strategies through various online websites have been developed. In rural communities e-services applications such as e-commerce, ehealth, e-judiciary and e-government have been devel-oped. However, most of these applications are failing to fully benefit the people in the societies because they are no modifications which are done to the applications as technology changes. This paper discusses the de-velopment of an intelligent negotiation module to enhance an e-commerce platform. The paper explains a negotiation application that has been developed and plugged to any existing e-Commerce shopping por-tal for the Dwesa Community in the Eastern cape province of South Africa and proposes an architecture for all other e-Services. This project ex-plained is undertaken within the Siyakhula Living Lab.
- Full Text:
- Date Issued: 2011
Accounting 1B: ACC 121E / 121
- Authors: Mnconywa, N , Bomba, M , Mtshwelo, L , Lockyear, M
- Date: 2010-11
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17423 , http://hdl.handle.net/10353/d1009792
- Description: Accounting 1B: ACC 121E / 121, examination November 2010.
- Full Text: false
- Date Issued: 2010-11
English Literate: ECL 320
- Authors: Formson, C , Nyika, N , Morkel, N , Blatchford, M , Scott, R
- Date: 2010-11
- Language: English
- Type: Examination paper
- Identifier: vital:18328 , http://hdl.handle.net/10353/d1011454
- Description: English Literate: ECL 320, degree examination November 2010.
- Full Text: false
- Date Issued: 2010-11
General Accounting 1B: AGC 121E & AAC 121
- Authors: Mnconywa, N , Mtshwelo, L , Bomba, M , Lockyear, M
- Date: 2010-11
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17424 , http://hdl.handle.net/10353/d1009793
- Description: General Accounting 1B: AGC 121E & AAC 121, examination November 2010.
- Full Text: false
- Date Issued: 2010-11
Taxation 3: ATA321E / ATV321E
- Authors: Stevens, N , Olivier, J
- Date: 2010-11
- Subjects: Taxation
- Language: English
- Type: Examination paper
- Identifier: vital:17405 , http://hdl.handle.net/10353/d1009766
- Description: Taxation 3: ATA321E / ATV321E, final assessment November 2010.
- Full Text:
- Date Issued: 2010-11
Accounting 1A: ACC 111 & 111E
- Authors: Mnconywa, N , Mtshwelo, L , Bomba, M , Lockyear, M
- Date: 2010-07
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17413 , http://hdl.handle.net/10353/d1009779
- Description: Accounting 1A: ACC 111 & 111E, supplementary examination July 2010.
- Full Text: false
- Date Issued: 2010-07
Business Mathematics: AMB 111
- Date: 2010-07
- Subjects: Business mathematics
- Language: English
- Type: Examination paper
- Identifier: vital:17469 , http://hdl.handle.net/10353/d1010284
- Description: Business Mathematics: AMB 111, examination July 2010.
- Full Text: false
- Date Issued: 2010-07
Business Management: BEC 111
- Authors: Masocha, Reginald , Rungani, Ellen , Puchert, Juliet , Rich, Guy
- Date: 2010-06
- Subjects: Business management
- Language: English
- Type: Examination paper
- Identifier: vital:17445 , http://hdl.handle.net/10353/d1010257
- Description: Business Management: BEC 111, examination June 2010.
- Full Text: false
- Date Issued: 2010-06
Academic Practices and Reasoning: APR 111
- Authors: Scott, R , Blatchford, M
- Date: 2010-05
- Language: English
- Type: Examination paper
- Identifier: vital:18268 , http://hdl.handle.net/10353/d1011264
- Description: Academic Practices and Reasoning: APR 111, examination May/June 2010.
- Full Text: false
- Date Issued: 2010-05
Introduction to Industrial Psychology: IPS 121
- Authors: Chipunza, C , Boqo, Z
- Date: 2010-02
- Subjects: Psychology, Industrial
- Language: English
- Type: Examination paper
- Identifier: vital:17484 , http://hdl.handle.net/10353/d1010458
- Description: Introduction to Industrial Psychology: IPS 121, supplementary examination February 2010.
- Full Text: false
- Date Issued: 2010-02
A watershed study on genetic diversity phylogenetic analysis of the Platypleura plumosa (Hemiptera Cicadidae) complex reveals catchment-specific lineages
- Authors: Price, Benjamin W , Barker, Nigel P , Villet, Martin H
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441711 , vital:73909 , https://doi.org/10.1016/j.ympev.2009.10.011
- Description: Historical biogeography studies have at their disposal a small suite of vicariance models to explain genetic differentiation within and between species. One of these processes involves the role of river catchments and their associated watersheds, in driving diversification and is applicable to both aquatic and terrestrial organisms. Although the idea of catchments structuring the genetic history of aquatic organisms is reasonably well understood, their effect on terrestrial organisms has largely been overlooked, with relevant studies being limited in scope. South Africa presents a perfect test-bed for elucidating this mechanism of diversification due to its rich biodiversity, range of climatic environments and many large river catchments. Here we use the cicadas of the Platypleura plumosa complex to highlight the importance of catchments and their associated watersheds in driving diversification of terrestrial invertebrates that lack an aquatic life-stage. Population structure was found to correspond to primary and in some cases secondary catchments; highlighting the need to include information on catchment structure when formulating hypotheses of population diversification. Recognizing that climate change in the near future is likely to alter the environment, and particularly precipitation patterns, insight into recent patterns of population change related to catchments may be useful in a conservation context.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 1: Drivers of change–water quantity and quality
- Authors: Mantel, Sukhmani K , Hughes, Denis A , Muller, Nikite W J
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438099 , vital:73435 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2398.pdf
- Description: Impacts of large dams are well-known and quantifiable, while small dams have generally been perceived as benign, both socially and envi-ronmentally. The present study quantifies the cumulative impacts of small dams on the water quality (physico-chemistry and invertebrate biotic indices) and quantity (discharge) of downstream rivers in 2 South African regions. The information from 2 South African national data-bases was used for evaluating the cumulative impacts on water quality and quantity. Physico-chemistry and biological data were obtained from the River Health Programme, and discharge data at stream flow gauges was obtained from the Hydrological Information System. Multivariate analyses were conducted to establish broad patterns for cumulative impacts of small dams across the 2 regions–Western Cape (winter rain-fall, temperate, south-western coast) and Mpumalanga (summer rain-fall, tropical, eastern coast). Multivariate analyses found that the chang-es in macroinvertebrate indices and the stream’s physico-chemistry were more strongly correlated with the density of small dams in the catchment (as a measure of cumulative impact potential) relative to the storage capacity of large dams. T-tests on the data, not including sam-ples with upstream large dams, indicated that the high density of small dams significantly reduced low flows and increased certain physico-chemistry variables (particularly total dissolved salts) in both the re-gions, along with associated significant reductions in a macroinverte-brate index (SASS4 average score per taxon). Regional differences were apparent in the results for discharge reductions and the macroin-vertebrate index. The results suggest that the cumulative effect of a high number of small dams is impacting the quality and quantity of wa-ters in South African rivers and that these impacts need to be systemat-ically incorporated into the monitoring protocol of the environmental wa-ter requirements.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 2: Biotic response – abundance and composition of macroinvertebrate communities
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:7095 , http://hdl.handle.net/10962/d1012437
- Description: This paper investigates the cumulative impacts of small dams on invertebrate communities in 2 regions of South Africa – the Western Cape and Mpumalanga. Previous research found reduced discharge, increased total dissolved salts, and a decrease in average score per taxon (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigated using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catchment in foothill-gravel streams (in both Western Cape and Mpumalanga) and in foothill-cobble streams (in Western Cape only). Opportunistic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and seasons) and detailed (at species level) collection of data to verify the results of cumulative effects of small dams. This can further the development of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
Ecological impacts of small dams on South African rivers Part 2: Biotic response–abundance and composition of macroinvertebrate communities
- Authors: Mantel, Sukhmani K , Muller, Nikite W J , Hughes, Denis A
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438087 , vital:73434 , ISBN 1816-7950 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2354.pdf
- Description: This paper investigates the cumulative impacts of small dams on inver-tebrate communities in 2 regions of South Africa–the Western Cape and Mpumalanga. Previous research found reduced discharge, in-creased total dissolved salts, and a decrease in average score per tax-on (ASPT; collected using SASS4 methods) at sites with high density of small dams in their catchment. These changes in ASPT are investigat-ed using the invertebrate abundance data available in the River Health Programme. Multivariate analyses found differences in invertebrate communities in rivers with high densities of small dams in their catch-ment in foothill-gravel streams (in both Western Cape and Mpuma-langa) and in foothill-cobble streams (in Western Cape only). Opportun-istic taxa that are tolerant of pollution, and capable of exploiting various habitats, and those that prefer slower currents increased in numbers, while other taxa that are sensitive to pollution and disturbance declined in numbers. Some regional differences were noted possibly reflecting climatic differences between the regions. Since the results of this study are correlative, it highlights the need for a systematic (by sites and sea-sons) and detailed (at species level) collection of data to verify the re-sults of cumulative effects of small dams. This can further the devel-opment of a framework for small-dam construction and management that will limit their impact on river catchments.
- Full Text:
- Date Issued: 2010
Histological validation of gonadal macroscopic staging criteria for Labeo cylindricus (Pisces: Cyprinidae)
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124593 , vital:35634 , https://doi.org/10.1080/15627020.2000.11657094
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Date Issued: 2010
Institutionalising service-learning
- Authors: Hlengwa, Amanda I
- Date: 2010
- Language: English
- Type: text , article
- Identifier: vital:29685 , http://hdl.handle.net/10520/EJC131578
- Description: Higher education has three core pillars: teaching, research and community engagement. Teaching and research endeavours have dominated university agendas. However, momentum in prioritising community engagement is growing. The developing emphasis placed on the third pillar raises an opportunity to investigate how community engagement is conceptualised and therefore prioritised within the higher education landscape. Community engagement is expressed as a continuum in higher education inclusive of five overlapping activities of which service-learning is just one. This paper outlines what service-learning is and its potential role in the transformation of higher education, as well as to signal the importance of institutional commitment to service-learning. Lastly, the paper offers a synthesis of the available literature on how to implement successfully service-learning modules.
- Full Text:
- Date Issued: 2010