391 research outputs found

    Implications of land use change for the sustainability of urban areas: A case study of Stellenbosch, South Africa

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    Abstract: Sustainable development, an objective of urban planning, is difficult to put into practice. Data to monitor sustainable land use management is often lacking, particularly in developing countries. This paper investigates the use of earth observation data for supporting sustainable land use planning. It proposes the use of decision consequence analysis (DCA) as a simple and structured way to put sustainable development into practice. The study demonstrates how land use change (LUC) which also includes land cover, the local land use mix index (LLUM) and land use frequency (LUF) can be used as indicators of objective land use sustainability..

    Fermentative attributes of wilted vs. unwilted Digitaria eriantha silage

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    Silages made from directly cut or wilted Digitaria eriantha treated with or without molasses were evaluated to determine fermentative characteristics. The grass was harvested at the boot stage of growth and the material was ensiled in 1 kg mini-silos. Treatments were arranged in a factorial design of two moisture levels (directly cut or wilted) and two molasses addition (with or without molasses). Each treatment was ensiled in 12 separate bottles. The pH of molasses added silage declined faster than the pH of silage without molasses. The pH of unwilted silages continued to decline up to day 120 post ensiling compared to wilted treatments. Lactic acid concentration was higher for molasses added silage than those made without molasses at all ensiling times, and also higher for directly cut silage than those wilted prior to ensiling. In direct cut silages, acetic acid concentration was lower for molasses added silage than those made without molasses at all ensiling times. In both silages, with or without molasses, the acetic acid concentrations were significantly higher for unwilted silage than silage wilted prior to ensiling. The ammonia nitrogen (NH3-N) as percentage of total nitrogen (N) was higher in unwilted silage than prior wilted silage without molasses, while in the presence of molasses the effect of wilting on NH3-N as percentage of total N was not significant. Keywords: Silage, fermentation process, moisture level, Digitaria eriantha, Smutsfinger grassSouth African Journal of Animal Science Vol. 37 (4) 2007: pp. 261-26

    The impact of succession planning on the sustainability of cane production by small-scale cane growers in the north coast of Kwazulu-Natal, South Africa

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    This paper forms part of a research study for a PhD, which has been conducted in the North Coast of KwaZulu-Natal and focuses on the sustainability of emerging cane growers. The research problem of the study was that cane growers cannot be sustained beyond the current generation of existing farmers because young people are not interested. Agriculture takes place in rural areas which are characterised by high levels of poverty. Cane farming, like other agricultural production activities, is the major economic driver in these areas. However, the current cane growers are ageing and the economy will be negatively impacted unless the youth succeed their parents as farmers. Sustainability of cane production depends on the preparedness of the offspring of the cane growers to succeed them as farmers.The results of the study revealed two responses. The first response suggested that young people whose parents are cane growers are willing to succeed their parents and become cane growers. The second response suggested that where discussions on succession planning have taken place there was an increase in the number of young people indicating an interest in succeeding their parents. The paper concludes with a recommendation that there is a need for developing succession planning in the North Coast farming area.KEY WORDS: Cane grower, cane farmer, sustainability, succession planning, youth, extension implications

    TarO : a target optimisation system for structural biology

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    This work was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC) Structural Proteomics of Rational Targets (SPoRT) initiative, (Grant BBS/B/14434). Funding to pay the Open Access publication charges for this article was provided by BBSRC.TarO (http://www.compbio.dundee.ac.uk/taro) offers a single point of reference for key bioinformatics analyses relevant to selecting proteins or domains for study by structural biology techniques. The protein sequence is analysed by 17 algorithms and compared to 8 databases. TarO gathers putative homologues, including orthologues, and then obtains predictions of properties for these sequences including crystallisation propensity, protein disorder and post-translational modifications. Analyses are run on a high-performance computing cluster, the results integrated, stored in a database and accessed through a web-based user interface. Output is in tabulated format and in the form of an annotated multiple sequence alignment (MSA) that may be edited interactively in the program Jalview. TarO also simplifies the gathering of additional annotations via the Distributed Annotation System, both from the MSA in Jalview and through links to Dasty2. Routes to other information gateways are included, for example to relevant pages from UniProt, COG and the Conserved Domains Database. Open access to TarO is available from a guest account with private accounts for academic use available on request. Future development of TarO will include further analysis steps and integration with the Protein Information Management System (PIMS), a sister project in the BBSRC Structural Proteomics of Rational Targets initiative.Publisher PDFPeer reviewe

    Influence of species/cultivar and season on the quality of Atriplex grown at different sites in South Africa

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    Abstract Atriplex species/cultivars [Atriplex nummularia, A. canescens (Santa Rita) and A. canescens (Field Reserve 1)] were compared in terms of chemical composition and in vitro digestibility. The plant material was sampled at different seasons (autumn and winter) and from different sites (Hatfield in the Gauteng Province and Mier and Lovedale, both in the Northern Cape Province) and were analysed for crude protein (CP), neutral detergent fibre (NDF) and in vitro digestibility (IVOMD). The CP and IVOMD of the leaves were higher than the stem for the Atriplex species. Leaf percentage for the autumn samples was not affected by species at Hatfield and Mier, but A. canescens (Field Reserve 1) had lower leaf percentage at Lovedale as well as for winter samples at Hatfield. At Lovedale, however, A. nummularia had the highest leaf : stem ratio compared to A. canescens (Santa Rita) and A. canescens (Field Reserve 1). Atriplex nummularia had a higher CP concentration than A. canescens (Field Reserve 1) and A. canescens (Santa Rita) at both Mier and Lovedale, but species/cultivar had no effect on CP concentration at Hatfield. Autumn samples had a higher CP concentration than winter samples at both Mier and Lovedale, but season had no effect on the N concentration at Hatfield. Atriplex nummularia had a lower NDF and higher IVOMD concentration compared to A. canescens (Santa Rita) and A. canescens (Field Reserve 1). Autumn samples were less fibrous and more digestible than winter samples. Atriplex nummularia seems to be better in terms of its nutritive value compared to A. canescens (Santa Rita) and A. canescens (Field Reserve 1), with better quality forage in autumn than winter. _______________________________________________________________________________

    A profile of hospital-admitted paediatric burns patients in South Africa

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    <p>Abstract</p> <p>Background</p> <p>Injuries and deaths from burns are a serious, yet preventable health problem globally. This paper describes burns in a cohort of children admitted to the Red Cross Children's Hospital, in Cape Town, South Africa.</p> <p>This six month retrospective case note review looked at a sample of consecutively admitted patients from the 1 <sup>st </sup>April 2007 to the 30 <sup>th </sup>September 2007. Information was collected using a project-specific data capture sheet. Descriptive statistics (percentages, medians, means and standard deviations) were calculated, and data was compared between age groups. Spearman's correlation co-efficient was employed to look at the association between the total body surface area and the length of stay in hospital.</p> <p>Findings</p> <p>During the study period, 294 children were admitted (f= 115 (39.1%), m= 179 (60.9%)). Hot liquids caused 83.0% of the burns and 36.0% of these occurred in children aged two years or younger. Children over the age of five were equally susceptible to hot liquid burns, but the mechanism differed from that which caused burns in the younger child.</p> <p>Conclusion</p> <p>In South Africa, most hospitalised burnt children came from informal settlements where home safety is a low priority. Black babies and toddlers are most at risk for sustaining severe burns when their environment is disorganized with respect to safety. Burns injuries can be prevented by improving the home environment and socio-economic living conditions through the health, social welfare, education and housing departments.</p

    Adapt or die : the views of Unisa student teachers on teaching practice at schools

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    This study focuses on the views of Unisa distance education (DE) students enrolled for the Postgraduate Certificate in Education (PGCE) who had completed their teaching practice. The research questions were: What are student teachers’ experiences of the way in which Unisa prepared them for teaching practice, the school context in which they practised teaching, the mentoring they received or did not receive and the way they were assessed? Socio-constructivist learning and situated learning theory were used as the theoretical framework. A maximum variation sampling technique was used to select 16 participants who had completed 10 weeks of teaching practice to participate in the study. Data were collected by means of semi-structured interviews. The findings indicate that, in preparing students for teaching practice, all role players need greater clarity on what is expected of students with regard to learning outcomes, assessment criteria and lesson plans. Students need to be placed at schools that will provide constructive learning environments, mentoring teachers should receive training and there should be greater clarity on the who, what and how of the assessment of students during teaching practice.Curriculum and Instructional Studie

    A multidisciplinary study of a small, temporarily open/closed South African estuary, with particular emphasis on the influence of mouth state on the ecology of the system

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    In 2005/2006 a multidisciplinary research programme that included studies on the hydrodynamics, sediment dynamics, macronutrients, microalgae, macrophytes, zoobenthos, hyperbenthos, zooplankton, ichthyoplankton, fish and birds of the temporarily open/closed East Kleinemonde Estuary was conducted. Particular attention was given to the responses of the different ecosystem components to the opening and closing of the estuary mouth and how this is driven by both riverine and marine events. Using a complementary dataset of daily estuary mouth conditions spanning a 14-year period, five distinct phases of the estuary were identified, including closed (average = 90% of the days), outflow (<1%), tidal (9%) and semi-closed (<1%). The open-mouth phase is critical for the movements of a number of estuary-associated fish (e.g. Rhabdosargus holubi) and invertebrates (e.g. Scylla serrata) between the estuary and sea. The timing of this open phase has a direct influence on the ability of certain estuaryassociated fish (e.g. Lithognathus lithognathus) and invertebrates (e.g. Palaemon peringueyi) to successfully recruit into the system, with a spring opening (October/November) being regarded as optimal for most species. The type of mouth-breaching event and outflow phase is also important in terms of the subsequent salinity regime once the berm barrier forms. A deep mouth breaching following a large river flood tends to result in major tidal inputs of marine water prior to mouth closure and therefore higher salinities (15–25). Conversely, a shallow mouth breaching with reduced tidal exchange during the open phase often leads to a much lower salinity regime at the time of mouth closure (5–15). The biota, especially the submerged macrophytes, respond very differently to the above two scenarios, with Ruppia cirrhosa benefiting from the former and Potamogeton pectinatus from the latter. River flooding and the associated outflow of large volumes of water through the estuary can result in major declines in zooplankton, zoobenthos, hyperbenthos and fish populations during this phase. However, this resetting of the estuary is necessary because certain marine invertebrate and fish species are dependent on the opening of the estuary mouth in order to facilitate recruitment of larvae and post-larvae into the system from the sea. Slight increases in the numbers of certain piscivorous and resident wading bird species were recorded when the estuary mouth opened, possibly linked to increased feeding opportunities during that phase

    Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

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    New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure
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