720 research outputs found

    Textile technology in Nepal in the 5th-7th centuries CE: the case of Samdzong

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    The first results of textile and dye analyses of cloth remains recovered in Samdzong, Upper Mustang, Nepal, are presented. The site consists of ten shaft tombs, dated between the 400-650 CE, cut into a high cliff face at an elevation of 4000 m asl. The dry climate and high altitude favoured the exceptional preservation of organic materials. One of the objects recovered from the elite Samdzong 5 tomb complex is composed of wool fabrics to which copper, glass and cloth beads are attached and probably constitutes the remains of a complex decorative headwear, which may have been attached to a gold/silver mask. SEM was used to identify the fibre sources of the textiles, which are all of animal nature. Two of the textiles are made of degummed silk. There is no evidence for local silk production suggesting that Samdzong was inserted into the long-distance trade network of the Silk Road. HPLC-DAD analysis permitted identification of a variety of organic dyes, including Indian lac, munjeet, turmeric and knotweed/indigo, while cinnabar was identified through micro Raman spectrometry. The results indicate that locally produced materials were used in combination with those likely imported from afar, including China and India.The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013-312603). Excavations at Samdzong have been supported by grants to Aldenderfer from the National Geographic Society and the Henry Luce Foundation. Many thanks to Alexia Coudray and Marie-Christine Maquoi for their dedicated work in the KIK/IRPA laboratory.This is the final version of the article. It first appeared from Taylor & Francis via http://dx.doi.org/10.1080/20548923.2015.111042

    Biodiversity's big wet secret: the global distribution of marine biological records reveals chronic under-exploration of the deep pelagic ocean

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    Background: Understanding the distribution of marine biodiversity is a crucial first step towards the effective and sustainable management of marine ecosystems. Recent efforts to collate location records from marine surveys enable us to assemble a global picture of recorded marine biodiversity. They also effectively highlight gaps in our knowledge of particular marine regions. In particular, the deep pelagic ocean - the largest biome on Earth - is chronically under-represented in global databases of marine biodiversity. Methodology/Principal Findings: We use data from the Ocean Biogeographic Information System to plot the position in the water column of ca 7 million records of marine species occurrences. Records from relatively shallow waters dominate this global picture of recorded marine biodiversity. In addition, standardising the number of records from regions of the ocean differing in depth reveals that regardless of ocean depth, most records come either from surface waters or the sea bed. Midwater biodiversity is drastically under-represented. Conclusions/Significance: The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in global databases of marine biological records. Given both its value in the provision of a range of ecosystem services, and its vulnerability to threats including overfishing and climate change, there is a pressing need to increase our knowledge of Earth's largest ecosystem

    IndOBIS, an Ocean Biogeographic Information System for assessment and conservation of Indian Ocean biodiversity

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    Compilation of inventories of components of coastal and marine biodiversity of Indian Ocean is hampered by several factors: low effort by some countries, preference to certain taxon, dwindling taxonomic expertise, low infrastructure of Information Technology, databases that are scattered and often non-interoperable, inconsistent reporting and a marked reluctance to share data and information. The creation of the Indian Ocean node of the Ocean Biogeographic Information System is meant to overcome some of these constraints. Benefiting from progress in Information Technology and building on the global efforts on understanding what lives in our seas, the IndOBIS aims to grow into a self-sustaining and collectively supported process of information collation, analysis and dissemination, serving the countries of the region and the international scientific community

    Differential food preferences in three co-occurring species of <i>Tisbe</i> (Copepoda, Harpacticoida)

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    Killed samples of a monoclonal bacterial strain and an axenic alga were offered in different proportions to Tisbe holothuriae, T. battagliai and T. furcata. Incorporation of carbon ranged from 0.05 and 0.39 ”g C (adult male)-1 d-1. Using a radiolabelling technique, the ratio in which the two food types were assimilated was compared to the ratio in which they were offered. Neither T. holothuriae nor its sibling species fed selectively under our conditions, but T. furcata showed a clear preference for bacteria. These findings constitute the first evidence for intrageneric dietary differentiation in harpacticoids. The results of the feeding experiments parallel observed differences in mandible structure. They render all the more acute the problem of resource partitioning between T. holothuriae and T. battagliai

    Efficient computation of high index Sturm-Liouville eigenvalues for problems in physics

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    Finding the eigenvalues of a Sturm-Liouville problem can be a computationally challenging task, especially when a large set of eigenvalues is computed, or just when particularly large eigenvalues are sought. This is a consequence of the highly oscillatory behaviour of the solutions corresponding to high eigenvalues, which forces a naive integrator to take increasingly smaller steps. We will discuss some techniques that yield uniform approximation over the whole eigenvalue spectrum and can take large steps even for high eigenvalues. In particular, we will focus on methods based on coefficient approximation which replace the coefficient functions of the Sturm-Liouville problem by simpler approximations and then solve the approximating problem. The use of (modified) Magnus or Neumann integrators allows to extend the coefficient approximation idea to higher order methods

    Risks of Tailings Dams Failure

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    Risk and Reliability in Geotechnical Engineerin

    Comment on: a two-stage fourth-order “almost” P-stable method for oscillatory problems

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    AbstractIn Chawla and Al-Zanaidi (J. Comput. Appl. Math. 89 (1997) 115–118) a fourth-order “almost” P-stable method for y″=f(x,y) is proposed. We claim that it is possible to retrieve this combination of multistep methods by means of the theory of parameterized Runge-Kutta-Nyström (RKN) methods and moreover to generalize the method discussed by Chawla and Al-Zanaidi (J. Comput. Appl. Math. 89 (1997) 115–118)

    The Colour of Ocean Data: International Symposium on oceanographic data and information management, with special attention to biological data. Brussels, Belgium, 25-27 November 2002: book of abstracts

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    Ocean data management plays a crucial role in global as well as local matters. The Intergovernmental Oceanographic Commission -with its network of National Oceanographic Data Centres- and the International Council of Scientific Unions- with its World Data Centres- have played a major catalysing role in establishing the existing ocean data management practices. No one can think of data management without thinking of information technology. New developments in computer hard- and software force us to continually rethink the way we manage ocean data. One of the major challenges in this is to try and close the gap between the haves and the have-nots, and to assist scientists in less fortunate countries to manage oceanographic data flows in a suitable and timely fashion. So far major emphasis has been on the standardisation and exchange of physical oceanographic data in open ocean conditions. But the colour of the ocean data is changing. The ‘blue’ ocean sciences get increasingly interested in including geological, chemical and biological data. Moreover the shallow sea areas get more and more attention as highly productive biological areas that need to be seen in close association with the deep seas. How to fill in the gap of widely accepted standards for data structures that can serve the deep ‘blue’ and the shallow ‘green’ biological data management is a major issue that has to be addressed. And there is more: data has to be turned into information. In the context of ocean data management, scientists, data managers and decision makers are all very much dependent on each other. Decision makers will stimulate research topics with policy priority and hence guide researchers. Scientists need to provide data managers with reliable and first quality controlled data in such a way that the latter can translate and make them available for the decision makers. But do they speak the same ‘language’? Are they happy with the access they have to the data? And if not, can they learn from each other’s expectations and experience? The objective of this symposium is to harmonize ocean colours and languages and create a forum for data managers, scientists and decision makers with a major interest in oceanography, and open to everyone interested in ocean data management
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