329 research outputs found

    Do black‐backed jackals exhibit spatial partitioning with African wild dogs and lions?

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    Publisher's version (útgefin grein)We thank Global Vision International, J. Power, W. Collinson and K. Potgieter-Forssman for help with tracking the radio-collared animals. This project was an initiative of the Carnivore Conservation Programme of the Endangered Wildlife Trust, South Africa, and the Wildlife Conservation Research Unit, Oxford University, U.K. Funding for J.F.K. was provided by a Research Fellowship from the Wildlife Conservation Society, New York, and a Marie Curie Fellowship from the European Commission, Brussels, Belgium. Sponsorship was provided by Jaguar Land Rover South Africa and De Beers Consolidated Mines.Peer Reviewe

    In situ epitaxial MgB2 thin films for superconducting electronics

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    A thin film technology compatible with multilayer device fabrication is critical for exploring the potential of the 39-K superconductor magnesium diboride for superconducting electronics. Using a Hybrid Physical-Chemical Vapor Deposition (HPCVD) process, it is shown that the high Mg vapor pressure necessary to keep the MgB2_2 phase thermodynamically stable can be achieved for the {\it in situ} growth of MgB2_2 thin films. The films grow epitaxially on (0001) sapphire and (0001) 4H-SiC substrates and show a bulk-like TcT_c of 39 K, a JcJ_c(4.2K) of 1.2×1071.2 \times 10^7 A/cm2^2 in zero field, and a Hc2(0)H_{c2}(0) of 29.2 T in parallel magnetic field. The surface is smooth with a root-mean-square roughness of 2.5 nm for MgB2_2 films on SiC. This deposition method opens tremendous opportunities for superconducting electronics using MgB2_2

    Schools, teachers and community: cultivating the conditions for engaged student learning

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    This paper reveals the nature of the actions, discussions and relationships which characterised teachers' and associated school personnel's efforts to engage poor and refugee students through a community garden located in a school in a low socio-economic urban area in south-east Queensland, Australia. These actions, discussions and relationships are described as both revealing and producing particular 'practice architectures' which help constitute conditions for practice-in this case, conditions for beneficial student learning. The paper draws upon interview data with teachers, other school staff and community members working in the school to reveal the interrelating actions, discussions and relationships involved in developing and using the garden for academic and non-academic purposes. By better understanding such interrelationships as practice architectures, the paper reveals how teachers and those in schooling settings learn to facilitate student learning practices that likely to assist some of the most marginalised students in schooling settings

    The influence of temperature on the development of Baltic Sea sprat (Sprattus sprattus) eggs and yolk sac larvae

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    In spring 2004 and 2005 we performed two sets of experiments with Baltic sprat (Sprattus sprattus balticus Schneider) eggs and larvae from the Bornholm Basin simulating ten different temperature scenarios. The goal of the present study was to analyse and parameterise temperature effects on the duration of developmental stages, on the timing of important ontogenetic transitions, growth during the yolk sac phase as well as on the survival success of eggs and early larval stages. Egg development and hatching showed exponential temperature dependence. No hatching was observed above 14.7°C and hatching success was significantly reduced below 3.4°C. Time to eye pigmentation, as a proxy for mouth gape opening, decreased with increasing temperatures from 17 days post hatch at 3.4°C to 7 days at 13°C whereas the larval yolk sac phase was shortened from 20 to 10 days at 3.8 and 10°C respectively. Maximum survival duration of non-fed larvae was 25 days at 6.8°C. Comparing the experimental results of Baltic sprat with existing information on sprat from the English Channel and North Sea differences were detected in egg development rate, thermal adaptation and in yolk sac depletion rate (YSDR). Sprat eggs from the English Channel showed significantly faster development and the potential to develop at temperatures higher than 14.7°C. North Sea sprat larvae were found to have a lower YSDR compared to larvae from the Baltic Sea. In light of the predictions for global warming, Baltic sprat stocks could experience improved conditions for egg development and surviva

    The Nature of Knowledge in Composition and Literary Understanding: The Question of Specificity

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    ↵PETER SMAGORINSKY is Assistant Professor, College of Education, University of Oklahoma, 820 Van Vleet Oval, Norman, OK 73019-0. He specializes in classroom literacy.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Blogging as community of practice: lessons for academic development?

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    As practices and expectations around doctoral writing continue to change, so too do the demands on academic developers and learning advisors. Social media is increasingly playing a role in doctoral education, just as it is in higher education more generally. This paper explores a blog initiated in 2012 to inform and support doctoral writing; since its inception, it has grown to include diverse and overlapping communities of academic developers, language and literacy specialists, supervisors, and students with shared interests in doctoral writing. This case study reflects on our experiences of entering the online environment through the lens of connectivist learning, noting the practices and communities that have been established, and the blog’s positioning in relation to our formal roles within universities. We consider how blogging relates to our work as academic developers. Details of our experiences, with our analysis and reflection of them, can inform other academic developers seeking to engage in social media networks as part of their working lives

    Diversity in collaborative research communities: a multicultural, multidisciplinary thesis writing group in public health

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    Writing groups for doctoral students are generally agreed to provide valuable learning spaces for Ph.D. candidates. Here an academic developer and the eight members of a writing group formed in a Discipline of Public Health provide an account of their experiences of collaborating in a multicultural, multidisciplinary thesis writing group. We consider the benefits of belonging to such a group for Ph.D. students who are operating in a research climate in which disciplinary boundaries are blurring and where an increasing number of doctoral projects are interdisciplinary in nature; in which both academic staff and students come from enormously diverse cultural and language backgrounds; and in which teamwork, networking and collaboration are prized but not always proactively facilitated. We argue that doctoral writing groups comprising students from diverse cultural and disciplinary backgrounds can be of significant value for postgraduates who wish to collaborate on their own academic development to improve their research writing and communication skills; at the same time, such collaborative work effectively builds an inclusive, dynamic research community.Cally Guerin, Vicki Xafis, Diana V. Doda, Marianne H. Gillam, Allison J. Larg, Helene Luckner, Nasreen Jahan, Aris Widayati and Chuangzhou X

    The Role of the Proteinase Inhibitor Ovorubin in Apple Snail Eggs Resembles Plant Embryo Defense against Predation

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    BACKGROUND: Fieldwork has thoroughly established that most eggs are intensely predated. Among the few exceptions are the aerial egg clutches from the aquatic snail Pomacea canaliculata which have virtually no predators. Its defenses are advertised by the pigmented ovorubin perivitellin providing a conspicuous reddish coloration. The nature of the defense however, was not clear, except for a screening for defenses that identified a neurotoxic perivitellin with lethal effect on rodents. Ovorubin is a proteinase inhibitor (PI) whose role to protect against pathogens was taken for granted, according to the prevailing assumption. Through biochemical, biophysical and feeding experiments we studied the proteinase inhibitor function of ovorubin in egg defenses. METHODOLOGY/PRINCIPAL FINDINGS: Mass spectrometry sequencing indicated ovorubin belongs to the Kunitz-type serine proteinase inhibitor family. It specifically binds trypsin as determined by small angle X-ray scattering (SAXS) and cross-linking studies but, in contrast to the classical assumption, it does not prevent bacterial growth. Ovorubin was found extremely resistant to in vitro gastrointestinal proteolysis. Moreover feeding studies showed that ovorubin ingestion diminishes growth rate in rats indicating that this highly stable PI is capable of surviving passage through the gastrointestinal tract in a biologically active form. CONCLUSIONS: To our knowledge, this is the first direct evidence of the interaction of an egg PI with a digestive protease of potential predators, limiting predator's ability to digest egg nutrients. This role has not been reported in the animal kingdom but it is similar to plant defenses against herbivory. Further, this would be the only defense model with no trade-offs between conspicuousness and noxiousness by encoding into the same molecule both the aposematic warning signal and an antinutritive/antidigestive defense. These defenses, combined with a neurotoxin and probably unpalatable factors would explain the near absence of predators, opening new perspectives in the study of the evolution and ecology of egg defensive strategies
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