255 research outputs found
Extracts from a dispensable life
No full textShort story by Kobus Moolman, in The swimming lesson and other short stories by author Kobus Moolman
Extracts from a dispensable life
No full textShort story by Kobus Moolman, in The swimming lesson and other short stories by author Kobus Moolman
PROTECTING ECOSYSTEMS BY WAY OF BIOLOGICAL CONTROL: CURSORY REFLECTIONS ON THE MAIN REGULATORY INSTRUMENTS FOR BIOLOGICAL CONTROL AGENTS, PRESENT AND FUTURE
No full textAlthough there are numerous threats to ecosystems and the resultant ecosystem services, alien and invasive plants (AIP) have been identified as being one of the major causes of ecosystem destruction. In addressing the threat of alien and invasive plants through the use of various mechanisms, the regulatory framework imposed by legislation is key in ensuring that that controlling AIPs does in fact not do more harm than good. One such control mechanism, which has the potential to do wonders or wreak havoc if not adroitly implemented, is that of using biological control agents. This contribution provides a brief overview on the three main regulatory instruments used to control biological control agents in South Africa, namely the Conservation of Agricultural Resources Act 43 of 1983, the Agricultural Pests Act 36 of 1983 and the National Environmental Management: Biodiversity Act 10 of 2004. It also considers possible future developments on the regulation of biological control agents
Kaart van bevolkingsverspreiding van die Unie van Suid-Afrika 1951 = Population distribution map of the Union of South Africa 1951 /
No full textSponsored and organized by Natural Resources Development Council.; Financed by National Council for Social Research.; Project proposed and directed by J.H. Moolman.; "The 1946 Census dates were used but the map was later revised to include the Census date of 1951."; Prepared for reproduction by the Trigonometrical Survey Office, 1954.; Booklet title: Verklaring van die kaart van bevolkingsverspreiding van die Unie van Suid-Afrika 1951 = Explanation of the population distribution map of the Union of South Africa, 1951 / prepared by J.H. Moolman.; Also available online http://nla.gov.au/nla.map-vn6813382.Population distribution map of the Union of South Africa, 195
A Singular Perspective on Chromosomal Replication: Studying Life Cells by Employing a Multi-disciplinary Approach
No full textInvestigating DNA replication in live E. coli cells using fluorescence microscopy and microfluidics.BionanoscienceApplied Science
Studying genomic processes at the single-molecule level: introducing the tools and applications
No full textTo understand genomic processes such as transcription, translation or splicing, we need to be able to study their spatial and temporal organization at the molecular level. Single-molecule approaches provide this opportunity, allowing researchers to monitor molecular conformations, interactions or diffusion quantitatively and in real time in purified systems and in the context of the living cell. This Review introduces the types of application of single-molecule approaches that can enhance our understanding of genome function.Accepted Author ManuscriptBN/Nynke Dekker La
Diversity of stem borer parasitoids and their associated wild host plants in South Africa and Mozambique
No full textThe diversity of lepidopterous stem borers, their parasitoids and their associated wild host plants was studied in South Africa between 2006 and 2009 and in Mozambique between 2005 and 2010. In South Africa, 20 species of parasitoids were recovered from 17 stem borer species collected on 16 wild host plant species. From Mozambique, 14 parasitoid species were recorded from 16 stem borer species collected on 14 wild host plant species. The highest diversity of parasitoids was recorded on stem borers that attacked the host plants Phragmites australis (7 spp.) and Panicum maximum (6 spp.), in South Africa and Mozambique, respectively. Bracon sp. (Hymenoptera: Braconidae) and Procerochasmias nigromaculatus (Hymenoptera: Ichneumonidae) were the most recorded parasitoid species in South Africa while Cotesia sesamiae (Hymenoptera: Braconidae) parasitized most stem borer species in Mozambique. The most common tachinid parasitoid recorded in this study was Sturmiopsis parasitica (Diptera: Tachinidae). Parasitism of stem borers during the off season was previously thought to occur mainly in natural habitats but this study shows that although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants, irrespective of whether collections were done during the cropping or off-season. Parasitoid beta diversity did not depend on habitat or host plant species, but was determined by stem borer diversity
Species diversity and distribution of lepidopteran stem borers in South Africa and Mozambique
No full textCountry-wide surveys of lepidopteran stem borers in wild host plants were undertaken between 2006 and 2009 in South Africa and 2005 and 2010 in Mozambique. A total of 4438 larvae were collected from 65 wild host plants in South Africa and 1920 larvae from 30 wild host plants in Mozambique. In South Africa and Mozambique, 50 and 39 stem borer species were recovered, respectively, with four new species and two new genera among noctuids. Less than 5% of the total number of species collected are considered to be economically important in Africa. These species were Busseola fusca (Fuller) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae) and Sesamia calamistis Hampson (Noctuidae). Data from this study and others in East Africa on the very low abundance of stem borers in wild host plants question the putative role of wild host plants as reservoir for stem borer pests. One new host plant family (Prioniaceae), as well as 24 and 13 wild hosts from South Africa and Mozambique respectively, was added to the list of known hosts in Africa
Winston Leonard Spencer Churchill -- a psychobiographical study
No full textPsychobiography is a qualitative approach to exploring and understanding the life story of an individual through the lens of psychological theory. The application of theory is typically conducted on the finished lives of well-known or enigmatic people. This study explores and describes the psychological development across the lifespan of Winston Leonard Spencer Churchill, by applying the Individual Psychology of Alfred Adler. Winston Churchill voted the greatest Briton of the twentieth century, was an author, painter, adventure, soldier, politician and Prime Minister that led the United Kingdom during World War Two. Extensive data has been examined in this work to ensure an accurate description of Winston Churchill‘s life. Alexander‘s model of identifying salient themes was used to analyse the data within a conceptual framework derived from the theory. Churchill‘s difficult childhood motivated him to succeed, his passion for the nation of Britain and his dislike of the Nazi regime meant that Churchill was always abreast with current affairs, anticipating every possible scenario of attack. When the time came to fight the Nazi‘s Churchill was ready to die for his country. The research findings highlight Churchill‘s ability to rise above his childhood stigmas and surpass all expectations and so cementing his name into the history of a country he loved and a democratic world he hoped for. Alfred Adler‘s Individual Psychology proposes that an individual‘s potential weaknesses can be used as a means to strive and achieve greatness within their sphere of influence
Modelling the marginal revenue of water in selected agricultural commodities: A panel data approach
No full textSouth Africa is a water-stressed country where water availability is an important constraint to economic and social development, and will become even more so in the future if this scarce resource is not managed effectively. In order to manage this scarce supply of water, we need to value it. This study focuses on the value of water in the agricultural sector, in particular the marginal revenue of water for six irrigation commodities namely avocados, bananas, grapefruit, mangoes, oranges and sugarcane. A quadratic production function was fitted with an SUR model specification in a panel data study from 1975 to 2002 to obtain marginal revenue functions for each of the six commodities. We found that mangoes are the most efficient commodity in its water use relative to revenue generated (marginal revenue of water equals R25.43/m³ in 2002) and sugarcane the least efficient (marginal revenue of water equals R1.67/m³ in 2002). The marginal revenue of water is not an indication of the true “market” price. Neither is it an indication what the administered price should be. The marginal revenue of water is rather a guideline for policy makers to determine which industries or commodities within an industry can generate the largest revenue per unit water appliedResource /Energy Economics and Policy,
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