Cytotoxic activity of marine sponge extracts from the sub-Antarctic Islands and the Southern Ocean
- Authors: Olsen, Elisabeth , De Cerf, Christopher , Dziwornu, Godwin A , Puccinelli, Eleonora , Parker-Nance, Shirley , Ansorge, Isabelle J , Samaai, Toufiek , Dingle, Laura M K , Edkins, Adrienne L , Sunassee, Suthananda N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66300 , vital:28931 , https://doi.org/10.17159/sajs.2016/20160202
- Description: publisher version , Over the past 50 years, marine invertebrates, especially sponges, have proven to be a valuable source of new and/or bioactive natural products that have the potential to be further developed as lead compounds for pharmaceutical applications. Although marine benthic invertebrate communities occurring off the coast of South Africa have been explored for their biomedicinal potential, the natural product investigation of marine sponges from the sub-Antarctic Islands in the Southern Ocean for the presence of bioactive secondary metabolites has been relatively unexplored thus far. We report here the results for the biological screening of both aqueous and organic extracts prepared from nine specimens of eight species of marine sponges, collected from around Marion Island and the Prince Edward Islands in the Southern Ocean, for their cytotoxic activity against three cancer cell lines. The results obtained through this multidisciplinary collaborative research effort by exclusively South African institutions has provided an exciting opportunity to discover cytotoxic compounds from sub-Antarctic sponges, whilst contributing to our understanding of the biodiversity and geographic distributions of these cold-water invertebrates. Therefore, we acknowledge here the various contributions of the diverse scientific disciplines that played a pivotal role in providing the necessary platform for the future natural products chemistry investigation of these marine sponges from the sub- Antarctic Islands and the Southern Ocean. Significance: This study will contribute to understanding the biodiversity and geographic distributions of sponges in the Southern Ocean. This multidisciplinary project has enabled the investigation of marine sponges for the presence of cytotoxic compounds. Further investigation will lead to the isolation and identification of cytotoxic compounds present in the active sponge extracts. , University of Cape Town; South African Medical Research Council; National Research Foundation (South Africa); CANSA; Rhodes University; Department of Science and Technology; Department of Environmental Affairs; SANAP
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- Date Issued: 2016
Decolonising education: visual arts, cohesion, transformation
- Authors: Nsele, Z
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146456 , vital:38527 , https://savah.org.za/2016/01/18/call-for-papers-savah-conference-2016/#more-174
- Description: Rethinking Art History and Visual Culture in a Contemporary Context. The Rhodes Must Fall” and “Fees Must Fall” campaigns which arose in South Africa in the course of 2015, while focused on transformative agendas in a broad sense, also emphasised how various inheritances from the West have played a fundamental role in shaping universities – not only in terms of their curricula but also their institutional cultures more generally. Occurring in a context where the humanities are under threat and where neoliberal forces may upset what we understand as fundamental to the academic project, these recent calls for critical engagement with institutional histories and practices suggest that reconsideration of disciplinary knowledges and understandings have become increasingly urgent.
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- Date Issued: 2016
Design of a Configurable Embedded Network Tap Flow Generation using NetFlow v9 and IPFIX Formats
- Authors: Pennefather, Sean , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427756 , vital:72460 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622779_Design_of_a_Configurable_Embedded_Network_Tap_Flow_Generation_using_NetFlow_v9_and_IPFIX_Formats/links/5b9a19f2299bf14ad4d6a591/Design-of-a-Configurable-Embedded-Network-Tap-Flow-Generation-using-NetFlow-v9-and-IPFIX-Formats.pdf
- Description: This paper describes the design of a $200 hardware apparatus capable of passively monitoring network transmission at wire speeds of 100Mbit/s and generating NetFlow v9 or IPFIX compliant network flows for a downstream monitoring infrastructure. Testing of the apparatus hardware confirmed no network disruptions regardless of operational or power state while still being capable of correctly monitoring network traffic when configured. System testing under situations of heavy load confirmed apparatus capability at monitoring network traffic and correct generation of network flows compliant with either NetFlow v9 or IPFIX standards.
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- Date Issued: 2016
Detecting derivative malware samples using deobfuscation-assisted similarity analysis
- Authors: Wrench, Peter , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429494 , vital:72617 , 10.23919/SAIEE.2016.8531543
- Description: The abundance of PHP-based Remote Access Trojans (or web shells) found in the wild has led malware researchers to develop systems capable of tracking and analysing these shells. In the past, such shells were ably classified using signature matching, a process that is currently unable to cope with the sheer volume and variety of web-based malware in circulation. Although a large percentage of newly-created webshell software incorporates portions of code derived from seminal shells such as c99 and r57, they are able to disguise this by making extensive use of obfuscation techniques intended to frustrate any attempts to dissect or reverse engineer the code. This paper presents an approach to shell classification and analysis (based on similarity to a body of known malware) in an attempt to create a comprehensive taxonomy of PHP-based web shells. Several different measures of similarity were used in conjunction with clustering algorithms and visualisation techniques in order to achieve this. Furthermore, an auxiliary component capable of syntactically deobfuscating PHP code is described. This was employed to reverse idiomatic obfuscation constructs used by software authors. It was found that this deobfuscation dramatically increased the observed levels of similarity by exposing additional code for analysis.
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- Date Issued: 2016
Detection of plant growth enhancing features in psychrotolerant yeasts from Patagonia (Argentina)
- Authors: Mestre, María C , Fontenla, Sonia , Bruzone, Marie C , Fernández, Natalia V , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448581 , vital:74744 , https://doi.org/10.1002/jobm.201500728
- Description: This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest‐Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin‐like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin‐like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern‐Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold‐temperate regions.
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- Date Issued: 2016
Developing a Multi Platform Countermeasure to Ensure a Secure Home
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427772 , vital:72461 , https://www.researchgate.net/profile/Ibraheem-Fries-laar/publication/312219190_Developing_a_Multi_Platform_Countermeasure_to_Ensure_a_Secure_Home/links/587747d508ae8fce492fb5e2/Developing-a-Multi-Platform-Countermeasure-to-Ensure-a-Secure-Home.pdf
- Description: This research proposes an investigation into the side channel analysis attacks against the AES algorithm on high powered devices. Currently the research field into this aspect is fairly new and there is room for more information to be discovered. This research proposes using a Raspberry Pi in conjunction with a Software Defined Radio to capture electromagnetic emanations in the low and high frequency domains. Two well-known side channel attacks will be used to recover the secret information based on the electromagnetic emanations. Furthermore, this research proposes investigating into a possible software countermeasure by using the high-powered devices features such as multi-threading.
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- Date Issued: 2016
Developing biosensors in developing countries: South Africa as a case study
- Authors: Fogel, Ronen , Limson, Janice L
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431661 , vital:72794 , xlink:href="https://doi.org/10.3390/bios6010005"
- Description: A mini-review of the reported biosensor research occurring in South Africa evidences a strong emphasis on electrochemical sensor research, guided by the opportunities this transduction platform holds for low-cost and robust sensing of numerous targets. Many of the reported publications centre on fundamental research into the signal transduction method, using model biorecognition elements, in line with international trends. Other research in this field is spread across several areas including: the application of nanotechnology; the identification and validation of biomarkers; development and testing of biorecognition agents (antibodies and aptamers) and design of electro-catalysts, most notably metallophthalocyanine. Biosensor targets commonly featured were pesticides and metals. Areas of regional import to sub-Saharan Africa, such as HIV/AIDs and tuberculosis diagnosis, are also apparent in a review of the available literature. Irrespective of the targets, the challenge to the effective deployment of such sensors remains shaped by social and economic realities such that the requirements thereof are for low-cost and universally easy to operate devices for field settings. While it is difficult to disentangle the intertwined roles of national policy, grant funding availability and, certainly, of global trends in shaping areas of emphasis in research, most notable is the strong role that nanotechnology, and to a certain extent biotechnology, plays in research regarding biosensor construction. Stronger emphasis on collaboration between scientists in theoretical modelling, nanomaterials application and or relevant stakeholders in the specific field (e.g., food or health monitoring) and researchers in biosensor design may help evolve focused research efforts towards development and deployment of low-cost biosensors.
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- Date Issued: 2016
Development and assessment of a USP Apparatus 3 dissolution test method for sustained-release Nevirapine matrix tablets
- Authors: Mwila, Chiluba , Khamanga, Sandile M M , Walker, Roderick B
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184779 , vital:44271 , xlink:href="https://doi.org/10.14227/dt230316p22"
- Description: Dissolution testing is a quality control tool used to assess batch-to-batch performance of dosage forms, thereby providing continued assurance of product quality. Analytical methods for the assessment of pharmaceutical product quality must be validated according to regulatory guidelines to ensure that tests are reliable and valid. Agitation rate, mesh pore size, surfactant concentration, and dissolution medium molarity are experimental parameters that may affect nevirapine (NVP) release and were investigated and optimized to ensure that consistent, reliable, and valid results using Apparatus 3 were produced. Agitation rate was investigated to establish an equivalent response to that observed for NVP release using Apparatus 2 at 50 rpm. A reciprocation rate of 5–10 dpm produced dissolution profiles that were similar to those observed using Apparatus 2. An increase in the molarity of the dissolution medium slightly increased the release rate of NVP, and a 50 mM buffer maintained at pH values mimicking gastrointestinal tract (GIT) conditions was selected for all experiments. With the addition of 2% sodium lauryl sulfate (SLS) to the dissolution medium, >80% NVP was released from the tablets over the test period. The NVP release rate increased with an increase in the mesh pore size; however, the extent of release was not affected by this parameter. Dissolution test samples were analyzed using HPLC, and dissolution methods were validated for NVP stability in the dissolution medium, specificity, linearity and range, repeatability, intermediate precision, and accuracy as defined by ICH. The dissolution method used for testing NVP tablets can be regarded as an appropriate tool for the evaluation of sustained-release (SR) NVP formulations and the impact of formulation composition and product quality attributes on drug release.
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- Date Issued: 2016
Development Discourse and Global History: From Colonialism to the Sustainable Development Goals. A book review
- Authors: Matthews, Sally
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142257 , vital:38063 , DOI: 10.1080/00220388.2016.1153185
- Description: Development Discourse and Global History: From Colonialism to the Sustainable Development Goals. A book review.
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- Date Issued: 2016
Development of a high-throughput bioassay to determine the rate of antimalarial drug action using fluorescent vitality probes
- Authors: Laming, Dustin
- Date: 2016
- Subjects: Malaria -- Africa , Plasmodium falciparum , Drug development , Fluorescence
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64434 , vital:28542
- Description: Malaria is one of the most prevalent diseases in Africa and the Plasmodium falciparum species is widely accepted as the most virulent, with a fatality rate of 15 – 20 % of reported cases of infection. While various treatments have been accepted into early stage clinical trials there has been little progress towards a proven vaccine. Pending a long term solution, endemic countries rely heavily on the development of innovative drugs with acute efficacy coupled with rapids mode of action. Until recently the rate of drug action has been measured by light microscopic examination of parasite morphology using blood slides of drug treated parasite cultures at regular time intervals. This technique is tedious and, most importantly, subject to interpretation with regards to distinguishing between viable and comprised parasite cells, thus making it impossible to objectively quantitate the rate of drug action. This study aimed to develop a series of bioassays using the calcein-acetoxymethyl and propidium iodide vitality probes which would allow the rate of drug action on Plasmodium falciparum malaria parasites to be assessed and ranked in relation to each other. A novel bioassay using these fluorescent vitality probes coupled with fluorescence microscopy was developed and optimized and allowed the rate of drug action on malaria parasites to be assessed i) rapidly (in relation to current assay techniques) and ii) in a semi-quantitative manner. Extrapolation to flow cytometry for improved quantification provided favourable rankings of drug killing rates in the pilot study, however, requires further development to increase throughput and approach the ultimate goal of producing a medium-throughput assay for rapidly assessing the rate of action of antimalarial drugs. Attempts to adapt the assay for use in a multiwell plate reader, as well as using ATP measurements as an indication of parasite vitality after drug treatment, was met with erratic results. The viability probes assay as it stands represents an improvement on other assay formats in terms of rapidity and quantification of live/compromised parasites in cultures.
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- Date Issued: 2016
Development of nanocomposites of phosphorus-nitrogen co-doped graphene oxide nanosheets and nanosized cobalt phthalocyanines for electrocatalysis
- Authors: Shumba, Munyaradzai , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188574 , vital:44766 , xlink:href="https://doi.org/10.1016/j.electacta.2016.07.079"
- Description: Conjugates of reduced phosphorus-nitrogen co-doped graphene oxide nanosheets (rPNDGONS), reduced phosphorus doped graphene oxide nanosheets (rPDGONS), reduced nitrogen doped graphene oxide nanosheets (rNDGONS), reduced pyrolised graphene oxide nanosheets (rpyGONS) with nanosized cobalt (II) phthalocyanine (CoPcNP) or cobalt tetra amino phenoxy phthalocyanine (CoTAPhPcNP) were characterised and tested for their electrocatalytic behaviour towards the detection of hydrogen peroxide. Cyclic and linear scan voltammetries, and chronoamperometry were used to evaluate the electrocatalytic nature of the designed probes. For hydrogen peroxide detection, CoPcNP-rPNDGONS-GCE oxidation gave sensitivity of 12.00 mA/M, limit of detection of 4.48 nM, a rate constant of 2.66 × 105 M−1 s−1, adsorption equilibrium constant of 3.7 × 102 M−1 and Gibbs free energy −14.84 kJmol−1. The lowest detection limit was obtained for CoTAPhPcNP-rPNDGONS-GCE at 1.21 nM.
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- Date Issued: 2016
Diatom-based water quality monitoring in southern Africa: challenges and future prospects
- Authors: Dalu, Tatenda , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124297 , vital:35590 , http://dx.doi.org/10.4314/wsa.v42i4.05
- Description: Diatoms are of significant ecological importance in aquatic ecosystems, which stems from their dynamic position at the base of the trophic web as primary producers. Because diatom communities have specific environmental requirements and respond rapidly to changes in environmental conditions they are often employed as a cost-effective method to assess anthropogenic impacts and health statuses of aquatic ecosystems, particularly in Europe and North America. The purpose of this review is to summarise the challenges and future prospects associated with biological water quality monitoring using diatoms with special focus on southern Africa. Much work still needs to be carried out on diatom tolerances, ecological preferences and ecophysiology. It is recommended that past research pertaining to African diatom taxonomy should be made readily accessible to all through electronic media for use as a reference point. Moreover, following the same approach as for macroinvertebrate biomonitoring, African and other developing countries can resort to intermediate diatom taxonomy (i.e. genus), which is easier, less time-consuming and requires less-skilled personnel. While the lack of capacity and baseline information on diatom community composition and ecological requirements represent significant hurdles, diatom biomonitoring potentially holds much promise for understanding the ecological functioning and management of aquatic ecosystems in southern Africa. The application of diatom-based water quality assessment protocols has direct and immediate value for use as an ‘added-value’ assessment tool in addition to the use of macroinvertebrates and fish indices as these can indicate anthropogenically impacted and pristine sites.
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- Date Issued: 2016
Disentangling the identities and distribution patterns of the introduced beachfleas Orchestia gammarellus and Platorchestia platensis (Crustacea: Amphipoda Talitridae) in South Africa
- Authors: Diemer, Natalie , Griffiths, Charles L , Hodgson, Alan N
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443163 , vital:74084 , https://doi.org/10.1080/15627020.2016.1268930
- Description: Two introduced beachfleas, Orchestia gammarellus and Platorchestia platensis, have been recorded from South Africa, but have been misidentified by some earlier researchers and, prior to this study, each was also known from just a few, scattered observations, such that their true distributions remained obscure. We illustrate both species to clarify the features that identify and distinguish them and determine their true distributions by re-examining historical samples and by collecting new material from estuaries and lagoons along the west and south coasts of South Africa. Adult males of O. gammarellus have slender antennae and characteristic expanded, flattened, oar-like distal segments on pereopod 7. Adult males of P. platensis have the peduncle of antenna 2 strongly swollen and have bulbous, but not flattened, distal segments on pereopod 7. Both species occur under wrack and other debris along the banks of estuaries and sheltered lagoons. Orchestia gammarellus is found only along the south-west coast, in the Berg River Estuary, Langebaan Lagoon and the Diep River Estuary. Previous records from Knysna were misidentifications of P. platensis. Platorchestia platensis is found at one west coast site, Langebaan Lagoon, but is widely distributed from Cape Point eastwards to at least Algoa Bay. Both species share the same habitats as several other native beachfleas and competitive interactions between native and introduced species merit investigation.
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- Date Issued: 2016
Distribution and use of cash income from basket and mat crafting: Implications for rural livelihoods in the Eastern Cape, South Africa
- Authors: Adam, Y O , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180434 , vital:43388 , xlink:href="https://doi.org/10.1080/14728028.2016.1186576"
- Description: The objective of this paper was to investigate the extent to which baskets and mats local trade contributes to rural livelihoods of the crafters’ household and community downstream income. Primary data were collected through structured interviews with 83 crafters from Noqhekwana village in Port St. Johns municipality using snowball sampling in May, 2015. The survey was supplemented by secondary data and direct observations. The findings show that crafting contributed 35% of crafter’s household total income. The received income is spent on expenses in the household and downstream actors depending on the crafter’s priorities. Lack of organization between crafters, access to sufficient raw material, and low prices were identified as major challenges involved in the production and trade of the products.
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- Date Issued: 2016
Diversity of bacteria isolated from the flies Musca domestica (Muscidae) and Chrysomya megacephala (Calliphoridae) with emphasis on vectored pathogens.
- Authors: Brits, Devon , Brooks, Margot , Villet, Martin H
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441935 , vital:73936 , https://hdl.handle.net/10520/EJC195091
- Description: We evaluated the bacteria occurring externally on Musca domestica and Chrysomya megacephala, the two most common synanthropic flies which may be found at many refusesites throughout the world. Bacteria cultured from 10 specimens of each species were isolated, Gram-stained and examined microscopically, and divided into morphologically distinct 'pseudospecies', to avoid excessive duplication of genetic identification. About 350 bp of the 16S ribosomalRNAgene was amplified from genomic DNA extracted from each 'pseudospecies', sequenced, and bacteria identified using BLASTn. Nineteen different types of colony were identified from M. domestica, with Pseudomonas sp. and Swine Manure Bacterium SP14 being most abundant. Chrysomya megacephala yielded 15 distinct pseudospecies with total colony counts approximating to 10 000 from 10 plates, where 80% of colonies were non-pathogenic Bacillus pumilus. A total of 18 species were identified genetically: three shared by the fly species; four unique to C. megacephala,, and 13 unique to M. domestica. Half of these 18 species were pathogenic, two or three others were food spoilers and the rest were environmental or commensal bacteria from soil or plant matter. This study added three new pathogenic strains of bacteria and one new environmental strain to the list of bacteria reported to be vectored by these flies.
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- Date Issued: 2016
Do indigenous street trees promote more biodiversity than alien ones? evidence using mistletoes and birds in South Africa
- Authors: Shackleton, Charlie M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64663 , vital:28587 , http://www.doi:10.3390/f7070134
- Description: Trees in urban landscapes provide a range of ecosystem services, including habitat, refugia,food, and corridors for other fauna and flora. However, there is some debate whether the richness and abundance of other biodiversity supported is influenced by the provenance of trees, i.e., native or non-native. This study assessed the presence of mistletoes and birds (and nests) in 1261 street trees. There were marked differences between native and non-native street trees, with the former having a significantly higher prevalence of birds (and nests) and supporting more species and in greater densities, whilst the latter supported a higher prevalence of mistletoes. Additionally, for birds, the proximity to green space, tree size and species were also important, whilst for mistletoes, the proximity to green space, slope aspect, and tree species were significant. Preference ratios indicated that some tree species had a higher than random occurrence of birds or mistletoes, whilst others had a low abundance. The indigenous tree species, Acacia karroo Hayne was the only reasonably abundant street tree species that was important for birds, nests, and mistletoes. At the street scale, there was a positive relationship between street tree species richness and bird species richness. These results emphasise the importance of selecting appropriate tree species if biodiversity conservation is a core outcome.
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- Date Issued: 2016
Dridex: Analysis of the traffic and automatic generation of IOCs
- Authors: Rudman, Lauren , Irwin, Barry V W
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429525 , vital:72619 , https://ieeexplore.ieee.org/abstract/document/7802932
- Description: In this paper we present a framework that generates network Indicators of Compromise (IOC) automatically from a malware sample after dynamic runtime analysis. The framework addresses the limitations of manual Indicator of Compromise generation and utilises sandbox environment to perform the malware analysis in. We focus on the generation of network based IOCs from captured traffic files (PCAPs) generated by the dynamic malware analysis. The Cuckoo Sandbox environment is used for the analysis and the setup is described in detail. Accordingly, we discuss the concept of IOCs and the popular formats used as there is currently no standard. As an example of how the proof-of-concept framework can be used, we chose 100 Dridex malware samples and evaluated the traffic and showed what can be used for the generation of network-based IOCs. Results of our system confirm that we can create IOCs from dynamic malware analysis and avoid the legitimate background traffic originating from the sandbox system. We also briefly discuss the sharing of, and application of the generated IOCs and the number of systems that can be used to share them. Lastly we discuss how they can be useful in combating cyber threats.
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- Date Issued: 2016
Dung beetle (Coleoptera Scarabaeoidea) assemblages in the western Italian Alps: benchmark data for land use monitoring
- Authors: Tocco, Claudia , Villet, Martin H
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441361 , vital:73879 , 10.3897/BDJ.4.e10059
- Description: Traditional agro-pastoral practices are in decline over much of the Alps (MacDonald et al. 2000), leading to shrub and tree encroachment, and this represents one of the main threats for the conservation of alpine biodiversity, as many plant and animal species are dependent on the presence of semi-natural open habitats. However, quantifying this environmental change and assessing its impact on biodiversity may be difficult, especially in the context of sparse historical survey data. The accessibility of contemporary data about local biodiversity surveys in general, and indicator taxa in particular, is an essential consideration for planning future evaluations of conservation status in the Alps and for conservation plans that use ecological indicators to monitor temporal changes in biodiversity. Dung beetles are important ecosystem service providers (Nichols et al. 2008) that have been assessed as a good ecological indicator taxon in several studies (reviewed by Nichols and Gardner 2011), and although the Alps is perhaps one of the best-studied regions in respect of dung beetles, there are still only eight readily-accessible publications. We have augmented and comprehensively reviewed the data from these publications.
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- Date Issued: 2016
Dynamic changes of soil surface organic carbon under different mulching practices in citrus orchards on sloping land
- Authors: Gu, Chiming , Liu, Yi , Mohamed, Ibrahim , Zhang, Runhua , Wang, Xiao , Nie, Xinxin , Jiang, Min , Brooks, Margot , Chen, Fang , Li, Zhiguo
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:28997 , ISSN 0168384 , https://doi.org/10.1371/journal.pone.0168384
- Description: Publisher version , Mulching management has been used in many places all over the world to improve agricultural sustainability. However, the cycling of carbon in the soil under applications of mulch on sloping arable land is not yet fully understood. A four-year field experiment was carried out in Xiaofuling watershed of Danjiangkou reservoir in China. The object was to evaluate the effects of the application of straw mulch (ST) and grass mulch (GT) on dynamic changes in soil organic carbon and its fractions. Results showed that mulch applied on the soil surface increased the contents of SOC and its active fractions in the soil. Compared to the control without cover (CK), ST and GT treatments increased the contents of SOC, LOC, DOC, POC and EOC by 14.73%, 16.5%, 22.5%, 41.5% and 21%, respectively, in the 0–40 cm soil layer, and by 17%, 14%, 19%, and 30%, respectively, in the 0–100 cm soil layer. The contents of organic carbon and its active fractions decreased with increasing soil depth in all of the treatments. SOC was accumulated in the period of December to the following March. The contents of soil DOC and LOC were high in January to March, while the contents of soil POC and EOC were high in June to September. The relative contents of soil organic carbon fractions were POC > EOC > LOC > DOC over the four years. Straw mulching had no significant effect on the changes in soil organic carbon active fractions during the different periods. Based on this long-term field experiment in Danjiangkou reservoir, we found that straw mulching had a significant effect on soil, increasing SOC content and stock in slopping arable land, and that live grass mulching was more effective than rice straw mulching. We discuss possible optimal periods for the implementation of mulching practices on sloping land.
- Full Text:
- Date Issued: 2016
E-Government as a Means to Support Communal, Large ICT Infrastructure in Poor Areas
- Authors: Gumbo, Sibukelo , Terzoli, Alfredo , Tsietsi, Mosiuoa
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431287 , vital:72761 , https://www.academic-bookshop.com/ourshop/prod_5067238-ECEG-2016-Proceedings-of-the-16th-European-Conference-on-eGovernment.html
- Description: Citizen-facing e-Government appears inevitable given current technol-ogy trends, and certainly has many advantages. One overlooked bene-fit, in our opinion, is its potential to make financially viable communal “large ICT” installations, which would diffuse ICT in poor communities where ICT is currently absent.(By “large ICT” we refer to end-user equipment such as desktops or laptops, on which would be possible to produce content, including software. The presence of “large ICT” in a community is critical in our opinion for the empowerment of the commu-nity, especially its younger component.) This paper explores this poten-tial in e-Government, describing a model conceptualized in the Siyakhu-la Living Lab in South Africa and partially implemented, through an inte-gration platform named “TeleWeaver”. The model behind TeleWeaver is an adaptation of the classic Internet business model-whereby users of services do not directly pay for the services they use. This model is especially relevant currently in South Africa, because of the an-nouncement by the government to pilot connecting to the internet gov-ernment facilities, including schools, in eight poor district municipalities.
- Full Text:
- Date Issued: 2016