6,040 research outputs found

    Names of fungal species with the same epithet applied to different morphs: how to treat them

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    The abolition of the separate naming of different morphs of the same fungal species in 2011 will inevitably result in many name changes in some genera. The working practices commended here are intended to minimize one category of these changes, that which can arise as a consequence of an author using the epithet of an asexual morph when describing the sexual morph of the same species. We consider that name proposed for the sexual morph in such cases should be treated as a formal error for a new combination and not as a new species, and so be corrected. This is interpreted as applying even where the author indicated that a new species was being described and designated a type. We argue that those formalities were a result of the requirements of the rules then in force, as the author recognized that a morph of a named species was being described, and not a new hitherto unnamed species was being reported - but was barred from making a new combination so used the same epithet for the new morph name instead. Where a type with the sexual morph was designated for the sexual morph, under this interpretation that no longer has nomenclatural status, the type being that of the basionym. The material for the sexual morph indicated as a type, would be available for designation as an epitype, though a modern sequenced sample with both sexual and asexual morphs would be more informative as an epitype in many cases. A proposal to regularize the working practice commended here, and also the converse situation where the sexual morph typified name is the earlier, will be made to the 2017 Shenzhen Congress

    Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy

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    We studied the interaction between phototrophic and chemolithoautotrophic sulphide-oxidizing microorganisms in natural microbial mats forming in sulphidic streams. The structure of these mats varied between two end-members: one characterized by a layer dominated by large sulphur-oxidizing bacteria (SOB; mostly Beggiatoa-like) on top of a cyanobacterial layer (B/C mats) and the other with an inverted structure (C/B mats). C/B mats formed where the availability of oxygen from the water column was limited (<5 mu M). Aerobic chemolithotrophic activity of the SOB depended entirely on oxygen produced locally by cyanobacteria during high light conditions. In contrast, B/C mats formed at locations where oxygen in the water column was comparatively abundant (445 mu M) and continuously present. Here SOB were independent of the photosynthetic activity of cyanobacteria and outcompeted the cyanobacteria in the uppermost layer of the mat where energy sources for both functional groups were concentrated. Outcompetition of photosynthetic microbes in the presence of light was facilitated by the decoupling of aerobic chemolithotrophy and oxygenic phototrophy. Remarkably, the B/C mats conserved much less energy than the C/B mats, although similar amounts of light and chemical energy were available. Thus ecosystems do not necessarily develop towards optimal energy usage. Our data suggest that, when two independent sources of energy are available, the structure and activity of microbial communities is primarily determined by the continuous rather than the intermittent energy source, even if the time-integrated energy flux of the intermittent energy source is greater

    Die plek van navorsing oor kosmiese strale in die fisika*

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    Reeds sedert die vroeë veertiger jare word navorsing in die departement Fisika op die gebied van kosmiese strale ge­ doen. In hierdie voordrag sal gepoog word om aan te toon wat kosmiese strale is en wat die plek daarvan in ’n fisikadepartement is. Vanselfsprekend sal dit onmoontlik wees om in die bestek van een lesing die terrein volledig te verken. Die orde van behandeling is soos volg: .Die ontdekking van kosmiese strale. Die samestelling en energieverdeling van die primêre strale. Die wisselwerking tussen kosmiese strale en die atmos- feer. Groot buie van kosmiese strale.Die variasie van die intensiteit van kosmiese strale met plek en tyd van waarneming. Herkoms van kosmiese strale

    Expanding access to HIV counselling and testing at schools – the Manguzi experience

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    South Africa&rsquo;s HIV epidemic disproportionately affects the youth.&sup1; The importance of knowing one&rsquo;s status via voluntary counselling and testing (VCT) is recognised as a key strategy in fighting the epidemic and is reflected in the National Strategic Plan (NSP),2 which has set targets of 70% of all adults knowing their status by 2011 and 25% of all adults having been tested in the past 12 months. The Human Sciences Research Council survey in 2008&sup1; showed that 50.8% of all South Africans 15 years and older have had an HIV test, pointing to wider acceptance of VCT. As a further response to reaching the NSP target, the national HIV counselling and testing campaign3 was launched in April 2010 with a focus on mobilising all South Africans to be tested for HIV and ensuring that every South African knows their HIV status. Both the NSP and the national HIV testing campaign recognise the importance of community mobilisation and community-based models of VCT to achieve these targets. The NSP in particular has a goal to expand successful strategies of testing outside health care facilities to cover 70% of all districts by 2011. Young people are reluctant to use health care facilities, and several &lsquo;youth friendly&rsquo; strategies have been tried to target adolescents. This case study serves to document the successes of one such community-based VCT strategy, aimed at young people in northern KwaZulu-Natal, South Africa

    Using stories to assist storytelling in a pastoral setting: Four female pastors in dialogue with Mary Magdalene

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    Sometimes we need a source of encouragement for restoring our own lives, to help us re-create ourselves. Using text as narrative texts opens up a multitude of possibilities in the work with clients in therapy. The story of Mary Magdalene told in John 20:11–18 is considered to be a healing story. This article aims to retell the story of her encounter with the resurrected Jesus, using the Gospel of Mary as an enlightening intertext. Because the story of Mary Magdalene’s encounter with Jesus is used as a healing story, the basic principles of transformative narrative theory are considered tobe useful in the analysis of this text. Mary Magdalene’s story is then discussed with three female pastors of the Netherdutch Reformed Church of Africa. The research opened up a discussion about spirituality. This article would be incomplete without reflecting on the spirituality stories of the group of co-researchers
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