125 research outputs found

    Reite plants: an ethnobotanical study in Tok Pisin and English

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    This book is the product of an extended collaboration between Porer Nombo and James Leach which took place during 1995, 1999 and 2004. It contains information provided by Porer on the uses of certain plants from the hinterland of the Rai Coast in Papua New Guinea (PNG), particularly the area between the Seng and Yakai rivers in the Mot 1 District where speakers of the Nekgini language reside (Figure 1). Nekgini people and their ancestors gathered this knowledge and have used plants in the way we describe here. Porer explained that this knowledge has been handed down through the generations and is still used today. Porer chose the plants to be included in the book based on his thoughts about which plants are most significant for Nekgini ‘customary’ uses. ‘Customary’ in this context (as translated from the Tok Pisin ‘kastom’) indicates processes and procedures which are deemed to be both specifically local in origin and application, and which harness powers and forces to the end of achieving viable and valuable forms of social life and person, as understood by Nekgini speakers. Many of these uses may seem esoteric or magical to English readers. It will be as well for readers to keep in mind that Nekgini distinctions between humans and environment,and between the practical and the decorative, for example, are different to those which underpin western scientific investigation and the technologies which emerge from it. This issue is discussed at some length, albeit in relation to the narrower issue of intellectual property, in Appendices 1 and 2. Many plants which Nekgini speakers use for quotidian purposes such as house construction and basketry have been omitted. We decided that as the use of such plants and materials is widely known and practiced in contemporary PNG, they could be left out of this record. There are two reasons we decided to publish this book. Firstly, for many years, Porer and others in Reite have been concerned that new lifestyles based on business and the cash economy have resulted in a loss of interest in practices and knowledge from the past. Porer asked James to write a book which would preserve ancestral knowledge of plants for future generations. Secondly, the work demonstrates the deep and complex knowledge of just one language group in PNG in relation to plants. This knowledge is part of a wider whole known as ‘kastom’. Papua New Guineans can and should be proud of their kastom. We hope to strengthen the use of such knowledge, and show that such understandings and practices should be treasured and utilised. There is a rich diversity of customs and knowledge in PNG, and we intend with this publication to generate interest in that diversity by documenting the practices of a particular place in some detail. A clear antecedent and inspiration are the two books published by Ian Saem Majnepand Ralph Bulmer: Birds of my Kalam country/Mnmon Yad Kalam Yakt (1977) and Animals the Ancestors Hunted: An Account of the Wild Animals of the Kalam Area, Papua New Guinea (2007). The photos were taken and the text co-authored by James Leach. James has lived for more than two years in Reite village and has written anthropological texts about Nekgini speakers’ kinship, social organisation,ownership practices, arts and ritual. A full list of his writing on Reite to date is presented in the ‘Select bibliography of writings on Reite by James Leach’,at the end of the book. The chapter divisions emerged from Porer’s discovery of plants as we walked in the forest together, and his way of introducing the use of the particular plant by saying things such as: “this is for hunting birds” or “this is to make sickness cold”. James suggested the collation of information on material culture, gardening, and spirits and love magic, into single chapters. Although the text is presented in both Tok Pisin and English, there are places where direct, word for word, translation has been eschewed in favour of a more readable text in one or the other language.2 The Tok Pisin spelling and orthography is based on F. Mihailic’s 1971, Dictionary and Grammar of Melanesian Pidgin, to give a standardised form for the ritten language. The authors are aware that at times this preference makes for a slightly outdated rendition of the language. There are also places where current Rai Coast convention has deliberately been used in the text. As for the scientific identification of the plants, we have received excellent assistance from a number of experts who are gratefully acknowledged. It is important to make clear here that James is not trained in botany. As an anthropologist, ethnobotany has never been his primary interest, and botanical experts have had to work mainly from photographs when suggesting identifications. A full collection of botanical specimens has not been made as part of this study. Even what we have achieved in the way of identification has been very time-consuming and has had to suffice for the present purpose. James was funded by the Economic and Social Research Council, United Kingdom (UK) during 1995 and 1999 and by King’s College Cambridge in 2004. He also gratefully acknowledges the support of the Leverhulme Trust through both a Special Research Fellowship in 1999, and The Philip Leverhulme Prize in 2004. Support also came from the Department of Social Anthropology at the University of Cambridge during 1999 and 2000 when parts of the book were prepared. Thanks are also due to Alan MacFarlane for financial support, and to Marilyn Strathern. In addition, we received invaluable assistance from the following people. On the Rai Coast, Yamui and Sangumae Nombo, Katak Pulumamie, Pupiyana De’anae, Palota Konga, Takarok Yamui and Pinbin Sisau. In Port Moresby, Justin Tkachenko assisted with the initial identification of some plants. Wayne Takeuchi from the Forest Research Institute in Lae was generous with his time providing scientific identification for many of the plants. In the UK, Paul Sillitoe and Christin Kocher Schmid looked at some of the photographs; Stephen Hugh-Jones, Francoise Barbira-Freedman and Tim Bayliss-Smith advised James on what an economic botany of this kind might look like, and Tim Whitmore provided many scientific identifications. Robin Hide made many useful suggestions and encouraged the publication when it was likely to fall by the wayside. Bruce Godfrey in the University Printing Service at Cambridge has been very helpful, both with advice and time. Katharina Schneider and Katie Segal organised, designed, and edited the text at various stages. From the Resource Management in Asia- Pacific Program at The Australian National University, John Burton has assisted with Tok Pisin spelling and usage, and Mary Walta has edited the manuscript and organised its final production. Fleur Rodgers and Rikrikiang supported and encouraged us throughout the work. We would like to thank all these people very much

    Domain size effects on the dynamics of a charge density wave in 1T-TaS2

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    Recent experiments have shown that the high temperature incommensurate (I) charge density wave (CDW) phase of 1T-TaS2 can be photoinduced from the lower temperature, nearly commensurate (NC) CDW state. Here we report a time-resolved x-ray diffraction study of the growth process of the photoinduced I-CDW domains. The layered nature of the material results in a marked anisotropy in the size of the photoinduced domains of the I-phase. These are found to grow self-similarly, their shape remaining unchanged throughout the growth process. The photoinduced dynamics of the newly formed I-CDW phase was probed at various stages of the growth process using a double pump scheme, where a first pump creates I-CDW domains and a second pump excites the newly formed I-CDW state. We observe larger magnitudes of the coherently excited I-CDW amplitude mode in smaller domains, which suggests that the incommensurate lattice distortion is less stable for smaller domain sizes.Comment: 8 pages, 8 figure

    Dynamic pathway of the photoinduced phase transition of TbMnO3_3

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    We investigate the demagnetization dynamics of the cycloidal and sinusoidal phases of multiferroic TbMnO3_3 by means of time-resolved resonant soft x-ray diffraction following excitation by an optical pump. Using orthogonal linear x-ray polarizations, we suceeded in disentangling the response of the multiferroic cycloidal spin order from the sinusoidal antiferromagnetic order in the time domain. This enables us to identify the transient magnetic phase created by intense photoexcitation of the electrons and subsequent heating of the spin system on a picosecond timescale. The transient phase is shown to be a spin density wave, as in the adiabatic case, which nevertheless retains the wave vector of the cycloidal long range order. Two different pump photon energies, 1.55 eV and 3.1 eV, lead to population of the conduction band predominantly via intersite dd-dd transitions or intrasite pp-dd transitions, respectively. We find that the nature of the optical excitation does not play an important role in determining the dynamics of magnetic order melting. Further, we observe that the orbital reconstruction, which is induced by the spin ordering, disappears on a timescale comparable to that of the cycloidal order, attesting to a direct coupling between magnetic and orbital orders. Our observations are discussed in the context of recent theoretical models of demagnetization dynamics in strongly correlated systems, revealing the potential of this type of measurement as a benchmark for such complex theoretical studies

    Ultrafast relaxation dynamics of the antiferrodistortive phase in Ca doped SrTiO3

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    The ultrafast dynamics of the octahedral rotation in Ca:SrTiO3 is studied by time resolved x-ray diffraction after photo excitation over the band gap. By monitoring the diffraction intensity of a superlattice reflection that is directly related to the structural order parameter of the soft-mode driven antiferrodistortive phase in Ca:SrTiO3, we observe a ultrafast relaxation on a 0.2 ps timescale of the rotation of the oxygen octahedron, which is found to be independent of the initial temperaure despite large changes in the corresponding soft-mode frequency. A further, much smaller reduction on a slower picosecond timescale is attributed to thermal effects. Time-dependent density-functional-theory calculations show that the fast response can be ascribed to an ultrafast displacive modification of the soft-mode potential towards the normal state, induced by holes created in the oxygen 2p states

    Review on Superconducting Materials

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    Short review of the topical comprehension of the superconductor materials classes Cuprate High-Temperature Superconductors, other oxide superconductors, Iron-based Superconductors, Heavy-Fermion Superconductors, Nitride Superconductors, Organic and other Carbon-based Superconductors and Boride and Borocarbide Superconductors, featuring their present theoretical understanding and their aspects with respect to technical applications.Comment: A previous version of this article has been published in \" Applied Superconductivity: Handbook on Devices and Applications \", Wiley-VCH ISBN: 978-3-527-41209-9. The new extended and updated version will be published in \" Encyclopedia of Applied Physics \", Wiley-VC
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