198 research outputs found

    Electrification of minibus taxis in the shadow of load shedding and energy scarcity

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    Significance:Electrification is expected to decarbonise transportation and forms part of the agenda to delay climate change. Electric vehicle sales have ballooned and production of combustion engines will stop soon. In sub-Saharan Africa the transition is slow. Minibus taxis carry more than 70% of commuters and little is known about their electrification requirements. Electrical demand planning is better with vehicle-based data than with passenger-based data. Stationary times provide ample time for taxis to recharge from the grid and solar, but the latter requires substantial stationary battery capacity to negate grid-impacting fast charging. Taxi energy requirements are approximately 200 kWh/day on average

    Can deliberate efforts to realise aspirations increase capabilities? A South African case study

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    This paper takes up Appadurai's suggestion that aspirations could be used as a key to unlock development for people who are economically marginalised, and that their capabilities could be increased by this approach. The notion of “aspirations” is theoretically and conceptually framed, and then Amartya Sen's use of the term capabilities as the space within which development should be assessed is explored. I subsequently describe a five-year programme in which economically marginalised women in Khayelitsha near Cape Town were assisted in voicing and attempting to realise their aspirations, while being assisted with access to some resources. Capability outcomes and constraints are described and analysed, and the question of adaptive preferences is addressed. I conclude that deliberate efforts to realise aspirations, accompanied by some facilitation, can increase capabilities, but that there are also structural constraints to capability expansion for these women that frustrate their aspiration of class mobility.International Bibliography of Social Science

    Guiding Classical Biological Control of an Invasive Mealybug Using Integrative Taxonomy

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    The analysed sequences were deposited in Genbank under accession numbers KP771926-KP771972. Mealybug slides are available at the Polytechnic University of Valencia (Valencia, Spain). Parasitoid slides are deposited at Università degli Studi di Napoli Federico II (Portici, Italy).[EN] Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a mealybug of Southern African origin that has recently been introduced into Eastern Spain. It causes severe distortions on young citrus fruits and represents a growing threat to Mediterranean citrus production. So far, biological control has proven unsatisfactory due to the absence of efficient natural enemies in Spain. Hence, the management of this pest currently relies only on chemical control. The introduction of natural enemies of D. aberiae from the native area of the pest represents a sustainable and economically viable alternative to reduce the risks linked to pesticide applications. Since biological control of mealybugs has been traditionally challenged by taxonomic misidentification, an intensive survey of Delottococcus spp. and their associated parasitoids in South Africa was required as a first step towards a classical biological control programme. Combining morphological and molecular characterization (integrative taxonomy) a total of nine mealybug species were identified in this study, including three species of Delottococcus. Different populations of D. aberiae were found on wild olive trees, in citrus orchards and on plants of Chrysanthemoides monilifera, showing intra-specific divergences according to their host plants. Interestingly, the invasive mealybug populations from Spanish orchards clustered together with the population on citrus from Limpopo Province (South Africa), sharing COI haplotypes. This result pointed to an optimum location to collect natural enemies against the invasive mealybug. A total of 14 parasitoid species were recovered from Delottococcus spp. and identified to genus and species level, by integrating morphological and molecular data. A parasitoid belonging to the genus Anagyrus, collected from D. aberiae in citrus orchards in Limpopo, is proposed here as a good biological control agent to be introduced into Spain.This work was supported by the European Union Seventh Framework Programme FP7-IRSES #269196 "IPRABIO" and FP7-IAPP #324475 "COLBICS" and FP7-IRSES #612566 "BIOMODICS". The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.Beltrà Ivars, A.; Addison, P.; Ávalos Masó, JA.; Crochard, D.; García Mari, F.; Guerrieri, E.; Giliomee, JH.... (2015). Guiding Classical Biological Control of an Invasive Mealybug Using Integrative Taxonomy. PLoS ONE. 10(6):1-14. https://doi.org/10.1371/journal.pone.0128685S11410

    Reconstruction of major maternal and paternal lineages of the Cape Muslim population

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    The earliest Cape Muslims were brought to the Cape (Cape Town - South Africa) from Africa and Asia from 1652 to 1834. They were part of an involuntary migration of slaves, political prisoners and convicts, and they contributed to the ethnic diversity of the present Cape Muslim population of South Africa. The history of the Cape Muslims has been well documented and researched however no in-depth genetic studies have been undertaken. The aim of the present study was to determine the respective African, Asian and European contributions to the mtDNA (maternal) and Y-chromosomal (paternal) gene pool of the Cape Muslim population, by analyzing DNA samples of 100 unrelated Muslim males born in the Cape Metropolitan area. A panel of six mtDNA and eight Y-chromosome SNP markers were screened using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Overall admixture estimates for the maternal line indicated Asian (0.4168) and African mtDNA (0.4005) as the main contributors. The admixture estimates for the paternal line, however, showed a predominance of the Asian contribution (0.7852). The findings are in accordance with historical data on the origins of the early Cape Muslims.Web of Scienc

    Is government contestability an integral part of the definition of democracy?

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    Is government contestability an integral part of the definition of democracy? The answer to this question affects the way we classify political systems in which, despite a formally open political structure, a dominant political group faces weak opposition from other political parties and civil society organizations – an indication of a low degree of government contestability. In Robert Dahl’s polyarchy, contestability is an essential dimension of democracy and, consequently, one-party dominance is classified as an ‘inclusive hegemony’ outside his conception of democracy. For procedural definitions of democracy, however, dominant party systems are legitimate outcomes of electoral competition provided that there have been no formal restrictions to the exercise of civil and political rights. The article examines the boundaries between democracy and authoritarianism, broadens the notion of authoritarian controls to include soft manipulative practices and explains why government contestability should be regarded as a constitutive property of democracy

    MicroRNA-151 and its hosting gene FAK (focal adhesion kinase) regulate tumor cell migration and spreading of hepatocellular carcinoma

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    CITATION: Giliomee, J. H. 2013. Entomology in South Africa: where do we come from, where are we now and where are we going? South African Journal of Science, 109(1/2), Art. #a004, doi: 10.1590/sajs.2013/a004.The original publication is available at http://sajs.co.zaEntomology in South Africa can be traced back to the mid-18th century when Ryk Tulbagh was governor at the Cape from 1751 to 1771. Tulbagh was interested in nature and instructed his gardener, J.A. Auge, to collect plants, insects and other animals for scientists at European universities. He also sent specimens to Linnaeus in Sweden, with whom he as a Dutchman corresponded in Latin, their only common language. To thank and honour him, Linnaeus named for him the plant genus Tulbaghia as well as the beautiful Mountain Pride butterfly Aeropetes tulbaghia L. (Lepidoptera: Satyridae) that occurs along the slopes of Table Mountain.http://sajs.co.za/entomology-south-africa-where-do-we-come-where-are-we-now-and-where-are-we-going/jan-h-giliomeePublisher's versio
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