Book Review: Global Governance and the New Wars
- Authors: Magadla, Siphokazi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298640 , vital:57723 , xlink:href="https://doi.org/10.1080/02589346.2015.1008676"
- Description: Mark Duffield's second edition of ‘Global Governance and the New Wars’ offers an important and biting critique of how different actors within the security and development discourse have adapted to the various transformations of war in the post-cold war era. In this picture drawn by Duffield, the power of states in the South continues to be eroded by an exclusionary market that is driven by the global political economy wherein state's development and security responsibilities are increasingly assumed by non-state actors (predominately constituted by Western aid agencies). Those who fall outside the bounds of the state, development and humanitarian aid agencies can be found operating in an expanding shadow economy that is also shaped by a global dynamics which make the conditions for ‘network war' possible. In this context, the lines between ‘war' and peace” are difficult to distinguish. Overall, the book paints a depressing picture on the lack of substantive changes in the livelihoods of the poor as attention has been directed to discussions about ‘new wars' or altered forms of violence that have characterized the post-cold war era. The book unforgivingly exposes the failures of the discursive changes post-cold war to reconceptualize development and security in terms that move beyond description and into substantive change especially regarding shifting the development discourse from its historic modernizing impulses.
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- Date Issued: 2015
Characterization of porphyrin nanorods on fluorine doped tin oxide glass sheet
- Authors: George, Reama C , Falgenhauer, Jane , Geis, Clemens , Nyokong, Tebello , Schlettwein, Derck
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193542 , vital:45344 , xlink:href="https://doi.org/10.1142/S1088424615500923"
- Description: Porphyrin nanorods (PNR) have been fabricated by electrostatic self-assembly of two oppositely charged porphyrin molecules. The free base meso-tetra-(4-phenylsulphonate) porphyrin (TPPS4)4) served as negatively charged counterpart for the positively charged metallo meso-tetra(4-NN-methylpyridyl) porphyrins (MTM’PyP) with either Sn, Co, Mn or In as central metal M. Films of PNR were prepared on fluorine doped tin oxide glass sheets (FTO) by using a drop-dry method. The electronic spectra revealed J-aggregation of the charged molecules for the colloid PNR as well as for the films. Transmission electron microscopy confirmed the formation of porphyrin nanorods. The laser microscope and scanning electron microscope (SEM) images of the PNR/FTO films showed the formation of three kinds of structures in the films which consist of differently branched or linear needles with their main axis grown in the direction of the solvent flow during preparation. During cyclic voltammetry either applying negative potentials from 0.0 V to -1.0 V or positive potentials from 0.0 V to ++2.2 V irreversible reduction or oxidation reactions were detected for the films. Consistently, SEM images taken following cyclic voltammetry showed the disintegration of the PNR on the films into smaller subunits. Spectroelectrochemical measurements showed the formation of porphyrin anionic radicals during oxidation by a decrease in the absorption intensities and broadening of spectra with an additional band appearing around 900 nm. A similar trend was observed when negative potentials were applied but in this case the cationic radical was produced. In both cases the decrease of the intensity of the J-aggregate confirms a loss of intermolecular coupling, again consistent with the smaller subunits observed in SEM analysis.
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- Date Issued: 2015
Characterization of some amino acid derivatives of benzoyl isothiocyanate: Crystal structures and theoretical prediction of their reactivity
- Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Lobb, Kevin A , Tshentu, Zenixole R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447952 , vital:74686 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.05.053"
- Description: The reaction of benzoyl isothiocyanate with L-serine, L-proline, D-methionine and L-alanine gave 2-[(benzoylcarbamothioyl)amino]-3-hydroxypropanoic acid (I), 1-(benzoylcarbamothioyl)pyrrolidine-2-carboxylic acid (II), 2-[(benzoylcarbamothioyl)amino]-4-(methylsulfanyl)butanoic acid (III) and 2-[(benzoylcarbamothioyl)amino]propanoic acid (IV), respectively. The compounds have been characterized by IR, NMR, microanalyses and mass spectrometry. The crystal structures of all the compounds have also been discussed. Compound II showed rotamers in solution. DFT calculations of the frontier orbitals of the compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity of these compounds. The calculations indicated that the carboxylic acid group in these compounds is unreactive hence making the conversion to benzimidazoles via cyclization on the carboxylic acids impractical. This has been further confirmed by the reaction of compounds I–IV, respectively, with o-phenylene diamine which was unsuccessful but gave compound V.
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- Date Issued: 2015
Comparative electrocatalytic studies of nanocomposites of mixed and covalently linked multiwalled carbon nanotubes and 4-(4, 6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt (II)
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189285 , vital:44834 , xlink:href="https://doi.org/10.1016/j.poly.2015.05.038"
- Description: Electrocatalytic behavior of 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II) (CoPyPc) when mixed or covalently mixed to multiwalled carbon nanotubes (MWCNTs) is reported. Infra-red spectroscopy was used to confirm amide linkage of the covalently linked nanocomposite. Rotating disk electrode (RDE) and cyclic (CV) voltammetry studies were used for the electrochemical characterization of the prepared phthalocyanine and MWCNT nanocomposite. The electrocatalytic effects of the nanocomposites of the cobalt phthalocyanine derivative were then investigated towards L-cysteine oxidation using both RDE and CV experiments, and the electrocatalytic performance of the covalently linked cobalt phthalocyanine-MWCNT was found to be superior over the mixed nanocomposite.
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- Date Issued: 2015
Comparisons of isotopic niche widths of some invasive and indigenous fauna in a South African river
- Authors: Hill, Jaclyn M , Jones, Roy W , Hill, Martin P , Weyl, Olaf L F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423711 , vital:72088 , xlink:href="https://doi.org/10.1111/fwb.12542"
- Description: Biological invasions threaten ecosystem integrity and bio-diversity, with numerous adverse implications for native flora and fauna. Established populations of two notorious freshwater invaders, the snail Tarebia granifera and the fish Pterygoplichthys disjunctivus, have been reported on three continents and are frequently predicted to be in di-rect competition with native species for dietary resources.
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- Date Issued: 2015
Connectivity through allochthony: Reciprocal links between adjacent aquatic and terrestrial ecosystems in South Africa
- Authors: Richoux, Nicole B , Moyo, Sydney , Chari, Lenin D , Bergamino, Leandro , Carassou, Laure , Dalu, Tatenda , Hean, Jeff W , Sikutshwa, Likho , Gininda, Simphiwe , Magoro, Mandla , Perhar, Gurbir , Ni, Felicity , Villet, Martin H , Whitfield, Alan K , Parker, Daniel M , Froneman, P William , Arhonditsis, George , Craig, Adrian J F K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438363 , vital:73454 , ISBN 978-1-4312-0679-7 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2186-1-15.pdf
- Description: An important aspect of the dynamics of nutrients and pollutants in natural systems is captured in the concept of allochthony, founded on the observation that nutrients and energy in a variety of forms are transferred between adjacent habitats, com-munities and ecosystems that are not routinely considered as connected. Different forms of nutrients and energy move across the conceptual boundaries of habitats via organisms’ activities or physical processes such as wind or water currents, and these transfers can represent important food subsidies. Such cross-partition ecolog-ical subsidies can augment the nutritional condition, biomass and biodiversity of communities, particularly where local production (or autochthony) alone may be inadequate to support local food webs. Furthermore, organic subsidies can influ-ence population dynamics, community interactions and ecosystem processes, and can represent dominant flux inputs in ecosystem budgets. Our intention was to ex-plore organic nutrient fluxes in relation to a primarily lotic (i.e. flowing) aquatic sys-tem at the scale of a hydrological catchment.
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- Date Issued: 2015
Contrasting signals of genetic diversity and historical demography between two recently diverged marine and estuarine fish species
- Authors: von Der Heyden, Sophie , Toms, Jessica A , Teske, Peter R , Lamberth, Stephen J , Holleman, Wouter
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445611 , vital:74407 , https://doi.org/10.3354/meps11191
- Description: Estuaries, at the confluence of marine and freshwater systems, are mostly of geologically recent origin and as such make excellent models for understanding recent speciation events. Using molecular approaches, we compared genetic diversity and demographic histories in 2 closely related southern African klipfish species, the marine Clinus superciliosus and the estuarine C. spatulatus. Strong genetic differentiation was identified using both mtDNA control region and nDNA S7 sequencing, despite some haplotype sharing. Coalescent-based modelling suggests that species divergence occurred during the Late Pleistocene or, more likely, during the Early Holocene, when present-day estuaries formed. Analyses of population demography suggest that C. superciliosus has undergone historical population expansion, whereas C. spatulatus is characterized by a population decline, potentially driven by repeated cycles of population crashes linked to the opening and closing of estuarine systems. This is also reflected in values of genetic diversity, which are almost an order of magnitude lower in the estuarine than in the marine species. Given the unique evolutionary history of C. spatulatus, a species that is restricted to only 2 South African estuaries, we highlight the need for a better understanding of the processes that have shaped the evolution of estuarine populations. The identification of unique genetic lineages in estuaries can help to better guide conservation and management efforts for some of South Africa’s most fragile habitats.
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- Date Issued: 2015
Critical realism, environmental learning and social-ecological change
- Authors: Price, Leigh , Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/436952 , vital:73319 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: The contemporary social-ecological condition is characterized by power-ful changes in the way that we relate to each other and to the environ-ment. This has led to increased ecological vulnerability, which is also ac-companied by ongoing, and increased societal vulnerability. Nevertheless there remain opportunities for developing new social-ecological rela-tions, and for social-ecological learning and change. This would seem to require a strong project of recovering ontology, and a challenging and broadening of dominant ways of knowing (Mignolo, 2000) that also tend to commit what Bhaskar describes as the ‘epistemic fallacy’, or the ‘the analysis or reduction of being to knowledge of being’ (Bhaskar, 2010, p. 1). In response, Bhaskar (ibid.) suggests critical realism as an alternative that embodies a ‘compatibility of ontological realism, epistemological relativism and judgmental rationality’. This includes a ‘re-vindication of ontology’ and the possibility of recognizing and accounting for structure, difference and change in the world in ways that escape ontological actu-alism and ontological monovalence or ‘the generation of a purely positive account of reality’ (ibid., p. 15).
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- Date Issued: 2015
Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation a biotechnological perspective
- Authors: Kumar, Ashwani , Dames, Joanna F , Gupta, Aditi , Sharma, Satyawati , Gilbert, Jack A , Ahmad, Parvaiz
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443998 , vital:74177 , https://doi.org/10.3109/07388551.2014.899964
- Description: Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, “omics” technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.
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- Date Issued: 2015
DDoS Attack Mitigation Through Control of Inherent Charge Decay of Memory Implementations
- Authors: Herbert, Alan , Irwin, Barry V W , van Heerden, Renier P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430339 , vital:72684 , https://www.academic-bookshop.com/ourshop/prod_3774091-ICCWS-2015-10th-International-Conference-on-Cyber-Warfare-and-Security-Kruger-National-Park-South-Africa-PRINT-ver-ISBN-978191030996.html
- Description: DDoS (Distributed Denial of Service) attacks over recent years have shown to be devastating on the target systems and services made publicly available over the Internet. Furthermore, the backscatter1 caused by DDoS attacks also affects the available bandwidth and responsiveness of many other hosts within the Internet. The unfortunate reality of these attacks is that the targeted party cannot fight back due to the presence of botnets and malware-driven hosts. These hosts that carry out the attack on a target are usually controlled remotely and the owner of the device is unaware of it; for this reason one cannot attack back directly as this will serve little more than to disable an innocent party. A proposed solution to these DDoS attacks is to identify a potential attacking address and ignore communication from that address for a set period of time through time stamping.
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- Date Issued: 2015
Deep genetic divergence between geographically isolated populations of the goldie barb (Barbus pallidus) in South Africa: potential taxonomic and conservation implications
- Authors: Chakona, Albert , Malherbe, Willem S , Gouws, Gavin , Swartz, Ernst R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443284 , vital:74105 , https://hdl.handle.net/10520/EJC177698
- Description: Barbus pallidus as it is presently defined has a disjunct distribution that is divided between northern and southern populations in South Africa. Sequence data from the cytochrome b gene region showed two distinct lineages that correspond to these geographically distant areas. Divergence between these two lineages was relatively high (5.5-6.5%) and comparable to typical interspecific divergences found between closely related southern African cyprinid fishes. Based on this deep genetic divergence, we conclude that the northern lineage may represent a previously unrecognised species or may belong to a different, but known species or species complex not associated with 'true' B. pallidus. These findings add to a growing body of evidence that freshwater fish diversity in southern Africa requires major revision.
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- Date Issued: 2015
Density and regrowth of a forest restio (Ischyrolepis eleocharis) under harvest and non-harvest treatments in dune forests of Eastern Cape Province, South Africa
- Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180828 , vital:43649 , xlink:href="https://doi.org/10.1007/s12231-015-9306-y"
- Description: Ischyrolepis eleocharis (Mast.) H.P.Linder is a perennial rush or sedge-like herb in the Restionaceae family and has been harvested for various uses from coastal forest dunes of South Africa. Around 2005, a ban on I. eleocharis harvesting in Bathurst coastal forest was instituted by provincial conservation authorities based on their unsubstantiated impression that the species population was decreasing. Here we report on the population density pre and post the harvest ban, as well as further explore the autecology of the species by assessing plant density relative to environmental factors (slope and aspect) and a controlled experiment on regrowth after harvesting at different intensities. The results show that the shoot density of both living and dead I. eleocharis increased significantly over the past eight years. This concurs with results from the harvesting experiment which showed that I. eleocharis recovered rapidly within a year of harvesting. Both aspect and slope play a key role in the distribution of I. eleocharis, with most plants found in open patches in the forest located on the summit and upper slopes of dunes facing the landward side. These results indicate that I. eleocharis is highly abundant and resilient to harvesting.
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- Date Issued: 2015
Dialectical critical realism and cultural historical activity theory (CHAT): Exploring and expanding learning processes in sustainable agriculture workplace contexts
- Authors: Mukute, Mutizwa
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436996 , vital:73322 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: Sustainable agriculture (its learning, practice and development) is becoming increasingly important in Africa and globally be-cause of its potential to reduce social ecological risks while simultaneously enhancing related sustainability and resilience. Against this background, the objectives of the study forming the basis of this chapter were to explore and expand the learn-ing and practice of sustainable agriculture in three research sites in southern Africa. This paper focuses on how the author worked with critical realism to underlabour Cultural Historical Activity Theory (CHAT) to address the research objectives. Us-ing a multiple case study approach, the author worked with 80 farmers, extension workers, sustainable agriculture facilitators and researchers and organic marketers to explore and expand their learning and practice of three kinds of sustainable agricul-ture: permaculture, organic farming and the Machobane Farm-ing System (MFS). In particular the author made use of critical realism’s dialectics, multiple layers of reality and causal expla-nation, double hermeneutics, and modes of inference to deep-en data generation, analysis and use. Working with critical real-ism enabled the study to: (a) pay attention to causal mecha-nisms and power relations; (b) provide explanatory critique; (c) achieve in-depth ‘exploration’ through inductive, abductive and retroductive analysis; and (d) overcome the constructivist limi-tations of CHAT. Critical realism also enabled the mobilization of research participants’ agency and reflexivity to respond to the socio-ecological issues and risks that they were facing. The author concluded that critical realism can be effectively used to underlabour constructivist and epistemological theo-ries for ontological depth; and to help understand and tackle contemporary social ecological issues.
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- Date Issued: 2015
Diversity in Human Sexuality: Implications for Policy in Africa
- Authors: Dugmore, Harry
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/453379 , vital:75249 , ISBN , https://doi.org/10.17159/assaf/0022
- Description: Although two-thirds of countries in the world no longer outlaw lesbian, gay, bisexual, transgender and intersex (LGBTI) relationships, same-sex relationships are still illegal in 76 countries. In the recent past, new laws have been passed in Russia, India, Nigeria, Burundi, Cameroon and Uganda and are being contemplated in other countries to further prohibit same-sex relationships or the so-called ‘promotion of homosexuality’. There is evidence that such new laws precipitate negative consequences not just for LGBTI persons and communities, but also for societies as a whole, including the rapid reversal of key public health gains, particularly in terms of HIV and AIDS and other sexual health programmes, increases in levels of social violence, some evidence of reduced economic growth, and the diversion of attention from sexual and other violence against women and children.
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- Date Issued: 2015
DNA-based identification of Lepidoptera associated with citrus in South Africa
- Authors: Marsberg, Tamryn , Hill, Martin P , Moore, Sean D , Timm, Alicia E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405782 , vital:70205 , xlink:href="https://hdl.handle.net/10520/EJC167513"
- Description: A number of insects, primarily Lepidoptera, cause damage to citrus in South Africa. A major limitation to the management and control of these pests is their correct identification. The aim of this study was to develop a database of gene sequences to aid in the identification of these Lepidoptera. Multiple specimens of 12 species were sequenced for the ~650 bp of the cytochrome oxidase I gene. These sequence data were supplemented and validated using sequences available in public databases. Results showed that each species could be unambiguously identified, and neighbour-joining analysis based on K2P distances formed highly supported, distinct clusters for each species, i.e. the maximum intraspecific genetic distance was less than that of the minimum interspecific genetic distances. Thus, this data set provides a molecular means to successfully identify the most important Lepidoptera associated with citrus in South Africa.
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- Date Issued: 2015
Ecological sustainability for non-timber forest products: dynamics and case studies of harvesting
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433656 , vital:72992 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: There is growing knowledge about and appreciation of the im-portance of Non-timber Forest Products (NTFPs) to rural liveli-hoods in developing countries, and to a lesser extent, devel-oped countries. However, there is also an assumption on the part of policy-makers that any harvesting of wild animal or plant products from the forests and other natural and modi-fied ecosystems must be detrimental to the long-term viability of target populations and species. This book challenges this idea and shows that while examples of such negative impacts certainly exist, there are also many examples of sustainable harvesting systems for NTFPs. The chapters review and pre-sent coherent and scientifically sound information and case studies on the ecologically sustainable use of NTFPs. They also outline a general interdisciplinary approach for assessing the sustainability of NTFP harvesting systems at different scales. A wide range of case studies is included from Africa, Asia and South America, using plant and animal products for food, crafts, textiles, medicines and cosmetics.
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- Date Issued: 2015
Ecologically sustainable harvesting of non-timber forest products: Disarming the narrative and the complexity
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433670 , vital:72993 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: As introduced at the outset of this book, the need for ecologically sustainable harvesting systems for tens of thousands of non-timber forest products (NTFPs) around the world is a requirement for the conservation of the species concerned, and the lives, livelihoods and economies that depend on those species. Ecological sustainability is not simply a ‘nice to have’, a marketing ploy or a conservation fad. Unsustainable harvesting leads to the decline, sooner or later, of NTFP gene pools, populations and species and hence the livelihoods, and species and ecosystem services dependent upon them. Often the negative impacts on peoples’ lives and incomes are not immediately apparent because they may substitute the diminishing returns from one species by harvesting another species, such as favoured firewood species for less preferred species (Madubansi and Shackleton 2007). However, the second, third or more substitute yields lower returns in quality or quantity (or both) than the most preferred species and so a trajectory of dwindling returns looms, either of the benefits obtained, or increased costs to access the benefits. On the other hand, the concept of an ecologically sustainable yield is relatively easy to grasp (Ticktin Chapter 3). All biological resources are renewable. If the rate of harvest is less than the rate of renewal, then the NTFP species or population should persist in the long term. This simplistic picture needs to be fine-tuned to ensure that there are no exacerbatory or synergistic impacts associated with the direct effects of harvesting (such as changes in browsing patterns or fire behaviour)(Ticktin and Shackleton 2011, Ticktin Chapter 3). Additionally, the effects at broader scales, ie beyond just the target species, need to be also taken into account, such as on pollinators, decomposers, nutrient cycles and the like (Ticktin 2004). But in principle, the definition and measurement of an ecologically sustainable yield is well within the means of modern science for the majority of plant and animal NTFP species.
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- Date Issued: 2015
Editorial. Perspectives on transformations in learning and education
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387277 , vital:68221 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137656"
- Description: Perspectives on transformations in learning and education
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- Date Issued: 2015
Effect of conventional and organic orchard floor management practices on arbuscular mycorrhizal fungi in a ‘Cripp’s Pink’/M7 apple orchard soil
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
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- Date Issued: 2015
Effect of temperature on development of the blowfly, Lucilia cuprina (Wiedemann)(Diptera: Calliphoridae)
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442116 , vital:73960 , https://doi.org/10.1007/s00414-015-1153-y
- Description: The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.
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- Date Issued: 2015