104 research outputs found

    Alpha- and Gammaproteobacterial Methanotrophs Codominate the Active Methane-Oxidizing Communities in an Acidic Boreal Peat Bog

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    The objective of this study was to characterize metabolically active, aerobic methanotrophs in an ombrotrophic peatland in the Marcell Experimental Forest, Minnesota, USA. Methanotrophs were investigated in the field and in laboratory incubations using DNA-stable isotope probing, expression studies on particulate methane monooxygenase (pmoA) genes, and amplicon sequencing of 16S rRNA genes. Potential rates of oxidation ranged from 14-17 ÎŒmol CH4 g dry wt soil-1 d-1. Within DNA-SIP incubations, the relative abundance of methanotrophs increased from 4% in situ to 25-36% after 8 -14 days. Phylogenetic analysis of the 13C-enriched DNA fractions revealed the active methanotrophs were dominated by the genera Methylocystis (Type II; Alphaproteobacteria), Methylomonas, and Methylovulum (Type I; Gammaproteobacteria). In field samples, a transcript-to-gene ratio of 1 to 2 was observed for pmoA in surface peat layers which attenuated rapidly with depth, indicating the highest methane consumption was associated with the 0-10 cm depth interval. Metagenomes and sequencing of cDNA pmoA amplicons from field samples confirmed the dominant active methanotrophs were Methylocystis and Methylomonas. Although Type II methanotrophs have long been shown to mediate methane consumption in peatlands, our results indicate members of the genera Methylomonas and Methylovulum (Type I) can significantly contribute to aerobic methane oxidation in these ecosystems

    Africa: SDP and Sports Academies

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    Within mainstream migration studies, there is a voluminous literature on migration development interactions and outcomes (cf. De Haas, 2010). As this Handbook reveals, there is also a significant and growing body of research on the relationships between sport and development. Falling between these two canons of academic work is a smaller literature which has explored the intersections between sports migration and development in the global South (Bale, 2004; Darby, 2000; Esson, 2015a; Klein, 2014). Much of this work has focused on football migration from the African continent, particularly West Africa, and has acknowledged that football academies, defined as facilities or coaching programs designed to produce talent predominantly for export, are pivotal in this process (Darby, Akindes and Kirwin, 2007). Recent scholarship has shown how aspirations to migrate and the academies that seek to facilitate this articulate with varying forms of social and economic development in complex ways, and produce more heterogeneous outcomes than were previously observed (Darby, 2013a; Dubinsky and Schler, 2017). This chapter explores these articulations in relation to football in Africa, predominantly Ghana where academies have become increasingly visible. While African football is the focus of this chapter, this discussion speaks to wider debates on the migration development nexus in the context of sport, namely the tension between sport development, the commodification of sporting talent, and aspirations to develop an individual through sport and thereby enact

    Public transport transformation : an incremental approach to delivering public transport systems in South Africa

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    Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.The rollout of Integrated Rapid Public Transport Networks (IRPTNs) in 13 cities across South Africa has been a significant step forward in the provision of safe, affordable and reliable public transport services to the communities of our cities and towns. The incorporation of the existing minibus taxi operators into these systems has fundamentally changed the role of local government and the existing operators in the provision of public transport services and these changes have not come without their risks. This paper explores some of the risks experienced by the current approach to the design of our IRPTNs and suggests an alternative approach to the transformation of public transport services in South Africa. This alternative approach attempts to build on the capacity that already exists within the public transport sector whilst still being able to deliver regular, reliable and affordable transport services without some of the institutional and financial strains currently being experienced.This paper was transferred from the original CD ROM created for this conference. The material was published using Adobe Acrobat 10.1.0 Technology. The original CD ROM was produced by CE Projects cc. Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: [email protected]

    Myocardial Fibrosis and Cardiac Decompensation in Aortic Stenosis

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    OBJECTIVES: Cardiac magnetic resonance (CMR) was used to investigate the extracellular compartment and myocardial fibrosis in patients with aortic stenosis, as well as their association with other measures of left ventricular decompensation and mortality. BACKGROUND: Progressive myocardial fibrosis drives the transition from hypertrophy to heart failure in aortic stenosis. Diffuse fibrosis is associated with extracellular volume expansion that is detectable by T1 mapping, whereas late gadolinium enhancement (LGE) detects replacement fibrosis. METHODS: In a prospective observational cohort study, 203 subjects (166 with aortic stenosis [69 years; 69% male]; 37 healthy volunteers [68 years; 65% male]) underwent comprehensive phenotypic characterization with clinical imaging and biomarker evaluation. On CMR, we quantified the total extracellular volume of the myocardium indexed to body surface area (iECV). The iECV upper limit of normal from the control group (22.5 ml/m(2)) was used to define extracellular compartment expansion. Areas of replacement mid-wall LGE were also identified. All-cause mortality was determined during 2.9 ± 0.8 years of follow up. RESULTS: iECV demonstrated a good correlation with diffuse histological fibrosis on myocardial biopsies (r = 0.87; p < 0.001; n = 11) and was increased in patients with aortic stenosis (23.6 ± 7.2 ml/m(2) vs. 16.1 ± 3.2 ml/m(2) in control subjects; p < 0.001). iECV was used together with LGE to categorize patients with normal myocardium (iECV <22.5 ml/m(2); 51% of patients), extracellular expansion (iECV ≄22.5 ml/m(2); 22%), and replacement fibrosis (presence of mid-wall LGE, 27%). There was evidence of increasing hypertrophy, myocardial injury, diastolic dysfunction, and longitudinal systolic dysfunction consistent with progressive left ventricular decompensation (all p < 0.05) across these groups. Moreover, this categorization was of prognostic value with stepwise increases in unadjusted all-cause mortality (8 deaths/1,000 patient-years vs. 36 deaths/1,000 patient-years vs. 71 deaths/1,000 patient-years, respectively; p = 0.009). CONCLUSIONS: CMR detects ventricular decompensation in aortic stenosis through the identification of myocardial extracellular expansion and replacement fibrosis. This holds major promise in tracking myocardial health in valve disease and for optimizing the timing of valve replacement. (The Role of Myocardial Fibrosis in Patients With Aortic Stenosis; NCT01755936)

    Access, participation and capabilities: Theorising the contribution of university bursaries to students’ well-being, flourishing and success

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    For the last 10 years, universities in England have been expected to offer financial support to low-income students alongside that provided by government. These bursaries were initially conceived in terms of improving access for under-represented groups, but attention has turned to their role in supporting student retention and success. This paper reports on two qualitative studies undertaken by contrasting universities that have been brought together due to their complementary findings. Semi-structured interviews were undertaken with a total of 98 students. Students’ views on bursaries and how they impact on their lives are reported and used to develop a descriptive model of the web of choices that students have in balancing finances and time. This is contextualised within Sen’s ‘capabilities approach’, to argue that providing access to higher education is insufficient if disadvantaged students are not able to flourish by participating fully in the university experience

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Decolonial education and geography: Beyond the 2017 Royal Geographical Society with the Institute of British Geographers annual conference

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    This review is inspired by the recent resurgence of grassroots movements aimed at the decolonisation of education. The departure point of the paper are the numerous, recent academic responses to campaigns such as Rhodes Must Fall, Why is My Curriculum White?, Why Isn't My Professor Black?, and #LiberateMyDegree. Following from there, the narrative is divided into two sections. The first part reviews theoretical approaches to decolonial education, especially those rooted in the modernity/coloniality/decoloniality paradigm. The second part analyses the ways in which geographers have applied these ideas to our discipline. The review pays particular attention to the 2017 Royal Geographical Society with the Institute of British Geographers annual conference, curated under the “Decolonising geographical knowledges” theme. I argue that as geographers, we have to continue reflecting on the meaning of decolonial praxis, especially in relation to geographical education, beyond the recent conference. To these ends, the review concludes with seven specific questions for geographers to consider in the near future
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