594 research outputs found

    The community work programme : potentials and problems

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    Abstract: This article provides a detailed and critically reflective ‘insider’ account of the origins and development of a Community Work Programme as a public employment programme intervention. The article explores the significant potential of such a Community Work Programme to reduce unemployment and improve socio-economic livelihoods for programme participants, and its potential to model public/private alignment across sectors that complements what can be accomplished within the budgetary constraints of the central government alone. It also describes the challenges of programme implementation as a social policy intervention, arising in part from the difficulties of scaling up successful pilots to create a nationwide programme. The article demonstrates real achievements but also the difficulties of engagement with the state by non-profit organisations, and the difficulties of forging sustainable partnerships between communities and government around shared

    Effects of wild and farm-grown macroalgae on the growth of juvenile South African abalone Haliotis midae Linnaeus

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    The effect of various macroalgal diets on the growth of grow-out (> 20 mm shell length) South African abalone Haliotis midae was investigated on a commercial abalone farm. The experiment consisted of four treatments: fresh kelp blades (Ecklonia maxima [Osbeck] Papenfuss) (~ 10 % protein); farmed, protein-enriched Ulva lactuca Linnaeus (~26 % protein) grown in aquaculture effluent; wild U. lactuca (~ 20 % protein); and a combination (mixed) diet of kelp blades + farmed U. lactuca. Abalone grew best on the combination diet (0.423 ± 0.02% weight dayˉ¹ SGR [specific growth rate]; 59.593 ± 0.02 µm dayˉ¹ DISL [daily increment in shell length]; 1.093 final CF [condition factor]) followed by the kelp only diet (0.367 ± 0.02 % weight dayˉ¹ SGR; 53.148 ± 0.02 µm dayˉ¹ DISL; 1.047 final CF), then the farmed, protein-enriched U. lactuca only diet (0.290 ± 0.02% weight dayˉ¹ SGR; 42.988 ± 0.03 µm dayˉ¹ DISL; 1.013 final CF) that in turn outperformed the wild U. lactuca only diet (-0.079 ± 0.01 % weight dayˉ¹ SGR; 3.745 ± 0.02 µm dayˉ¹ DISL; 0.812 final CF). The results suggest that protein alone could not have accounted for the differences produced by the varieties of U. lactuca and that the gross energy content is probably important.Web of Scienc

    BFKL and CCFM final states

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    I give a brief presentation of recent results on the equivalence of BFKL and CCFM small-x final states, and discuss their implications for phenomenology.Comment: 4 pages. Talk presented at 7th International Workshop on Deep Inelastic Scattering, Zeuthen, Germany, April 199

    Rapid assessment of tissue nitrogen in cultivated Gracilaria gracilis (Rhodophyta) and Ulva lactuca (Chlorophyta)

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    Tissue nitrogen content and thallus colour were quantified using a rapid assessment method based on the Pantone® matt uncoated formula guide for raft-cultivated Gracilaria gracilis Steentoft Irvine et Farnham at Saldanha Bay and tank-cultivated Ulva lactuca Linnaeus at Jacobsbaai in 2001 – 2002. A relationship between thallus colour and tissue nitrogen, as well as a transition between green-yellows and yellow-browns that occurs between 0.8 – 1.3 mg N per g tissue (Pantone® colours 460U – 455U) for Gracilaria were found, with the green-yellow colour indicating nitrogen-starved material and the yellow-browns indicating nitrogen-replete material. For Ulva a transition between green and yellow-green occurred at a tissue nitrogen content of between 1.5 – 1.7 mg N per g tissue (Pantone® colours 585U and 583U). This relationship can be used by seaweed farmers for cultivation management as a quick guide to determine nutritional status of the seaweeds, and as an indication of protein content when the seaweeds are used as feeds.Web of Scienc

    Comparing community structure on shells of the abalone Haliotis midae and adjacent rock: implications for biodiversity

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    This paper concerns the effects on biodiversity of depletion 24 of the South African abalone Haliotis midae, which is a long-lived species with a large corrugated shell that provides a habitat for diverse benthic organisms. We compared community structure on H. midae shells with that on adjacent rock at three sites (Cape Point and Danger Point sites A and B), and at two different times of the year at one of these sites. Shells of H. midae consistently supported communities that were distinctly different from those on rock. In particular, three species of non-geniculate (encrusting) corallines, Titanoderma polycephalum, Mesophyllum engelhartii and Spongites discoideus were all found either exclusively or predominantly on shells, whereas another non-geniculate coralline, Heydrichia woelkerlingii, occurred almost exclusively on adjacent rock. The primary rocky substratum, however, supported a higher number of species than abalone shells. Possible reasons for the differences between the two substrata include the relative age, microtopography and hardness of the substrata; the abundance of grazers on them; and the relative age of different zones of the abalone shell, which support communities at different stages of succession. Diversity on shells was lowest in zones that were either very young or very old, in keeping with the intermediate disturbance hypothesis. The distinctiveness of shell epibiota will increase diversity despite having a lower diversity than that of adjacent rock. Decimation of H. midae by overfishing therefore has implications biodiversity conservation.Web of Scienc

    South African seaweed aquaculture: A sustainable development example for other African coastal countries

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    The green seaweed Ulva is one of South Africa's most important aquaculture products, constituting an important feed source particularly for abalone (Haliotis midae L.), and utilized as a bioremediation tool and other benefits such as biomass for biofuel production and for integrated aquaculture. Besides Ulva spp, Gracilaria spp. are also cultivated. Wild seaweed harvest in South Africa totals 7,602 mt, compared to 2,015 mt of cultivated Ulva. To mitigate for the reliance on wild harvesting, the South African seaweed aquaculture industry has grown rapidly over the past few decades. On-land integrated culture units, with paddle-wheel raceways, are now widely viewed as the preferred method of production for the industry. The success of seaweed aquaculture in South Africa is due to a number of natural and human (industrial) factors. The development of the seaweed aquaculture industry has paralleled the growth of the abalone industry, and has been successful largely because of bilateral technology transfer and innovation between commercial abalone farms and research institutions. In South Africa seaweeds have been used commercially as feedstock for phycocolloid production, for the production of abalone feed, and the production of Kelpak and Afrikelp, which are plant-growth stimulants used in the agricultural sector. Additionally, Ulva is being investigated for large-scale biogas production. The South African seaweed industry provides a template that could be used by other coastal African nations to further their undeveloped aquaculture potential

    Predicting formative feedback practices: improving learning and minimising a tendency to ignore feedback

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    IntroductionTeacher conceptions of feedback ideally predict their feedback practices, but little robust evidence identifies which beliefs matter to practices. It is logical to presume that teacher conceptions of feedback would align with the policy framework of an educational jurisdiction. The Teacher Conceptions of Feedback (TCoF) inventory was developed in New Zealand which has a relatively low-stakes, formative policy framework.MethodsThis study surveyed 451 Swedish teachers working in Years 1-9, a policy context that prioritises teachers using multiple data sources to help students learn. The study used a translated version of the TCoF inventory, but isolated six items related to formative feedback practices from various factors.ResultsA six-factor TCoF was recovered (Praise, Improvement, Ignore, Required, PASA, and Timely), giving partial replication to the previous study. A well-fitting structural equation model showed formative practices were predicted by just two conceptions of feedback (i.e., feedback improves learning and students may ignore feedback).DiscussionThis study demonstrates that the TCoF inventory can be used to identify plausible relations from feedback beliefs to formative feedback practices

    J/\psi-dissociation by a color electric flux tube

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    We adress the question of how a c−cˉc-\bar{c}-state (a J/ψJ/\psi ) can be dissociated by the strong color electric fields when moving through a color electric flux tube. The color electric flux tube and the dissociation of the heavy quarkonia state are both described within the Friedberg-Lee color dielectric model. We speculate on the importance of such an effect with respect to the observed J/ψJ/\psi -suppression in ultrarelativistic heavy ion collisions.Comment: 19 pages, 6 PostScript figures included, LaTe

    Abalone farming in South Africa: an overview with perspectives on kelp resources, abalone feed, potential for on-farm seaweed production and socio-economic importance

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    The South African abalone cultivation industry has developed rapidly and is now the largest producer outside Asia. With a rapid decline in wild abalone fisheries, farming now dominates the abalone export market in South Africa. Kelp (Ecklonia maxima) constitutes the major feed for farmed abalone in South Africa, but this resource is now approaching limits of sustainable harvesting in kelp Concession Areas where abalone farms are concentrated. This paper gives an overview of the development of the South African abalone industry and analyses how abalone farming, natural kelp beds and seaweed harvesting are interlinked. It discusses options and constraints for expanding the abalone industry, focussing especially on abalone feed development to meet this growing demand. Kelp will continue to play an important role as feed and kelp areas previously not utilised may become cost-effective to harvest. There are many benefits from on-farm seaweed production and it will probably be a part of future expansion of the abalone industry. Abalone waste discharges are not at present regarded as a major concern and farming brings important employment opportunities to lower income groups in remote coastal communities and has positive spill-over effects on the seaweed industry and abalone processing industry.Web of Scienc

    Baryon Number Fluctuation and the Quark-Gluon Plasma

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    We show that ωB\omega_B or ωBˉ\omega_{\bar B}, the squared baryon or antibaryon number fluctuation per baryon or antibaryon, is a possible signature for the quark-gluon plasma that is expected to be created in relativistic heavy ion collisions, as it is a factor of three smaller than in an equilibrated hadronic matter due to the fractional baryon number of quarks. Using kinetic equations with exact baryon number conservation, we find that their values in an equilibrated matter are half of those expected from a Poisson distribution. Effects due to finite acceptance and non-zero net baryon number are also studied.Comment: discussion and references added, version to appear in PR
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