1,112 research outputs found

    Isolation, identification and culture of the marine rotifer Colurella adriatica Ehrenberg, 1831 (Family: Lepadellidae) from Andaman & Nicobar Islands: A promising live feed for larval rearing of high value shellfishes and finfishes

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    An extremely small rotifer was isolated from the micro zooplankton samples collected during February, 2014 from Havelock islands of Andaman and Nicobar Islands. The species was identified as Colurella adriatica Ehrenberg, 1831 (Family: Lapadellidae). Its lorica length under culture period ranged from 47.530 to 98.868 μm and width from 34.308 to 56.277 μm. The size of the eggs, neonates and adults are also documented. Comparison of size of C. adriatica with Brachionus plicatilis (L type) and B. rotundiformis (S and SS type) revealed that C. adriatica is smaller in length and width than the SS-type rotifer which is currently used as a first feed in marine tropical fish larval rearing. However, the larvae of many marine food fishes including groupers and high value marine ornamental fishes are unable to consume the SS-type rotifers as a first feed due to their extremely small mouth gape. The culture of C. adriatica was carried out using Nannochloropsis oculata Diet-I), N. oculata and yeast (0.01g/litre) (Diet-II), Yeast (0.01g/litre) alone (Diet-III). Average population density of C. adriatica with these diets reached a maximum of 1000 nos. of individuals /ml on 10th day of culture on feeding with Diet-I; 950 nos. /ml on 14th day (Diet-II) and 650 nos. /ml on 15th day of culture (Diet-III). Diet I &II and Diet II &III did not show any significant difference (P>0.05) whereas, Diet I and III showed significant difference (P<0.01). Preliminary studies of C. adriatica as a feed to the larvae of Stenopus hispidus, Lysmata amboinensis and Pomacentrus caeruleus showed better survival than larvae fed with B. routundiformis during first phase of larval rearing

    Sampling India: examining cultural appropriation, intercultural exchange, and the Othering of Indian music in hip-hop and reggaeton

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    Since Edward Said’s Orientalism (1978), scholars have continued to expound upon Said’s binary analysis of ‘Orient and Occident’. In popular music studies, India is primarily explored through its influence on psychedelic rock (Lavezzoli, 2007; Bakrania, 2013), or the impact of bhangra in shaping diasporic South Asian identities (Sharma, 1996; Dudrah, 2002). However, the role of digital sampling in the Othering of Indian culture is relatively undertheorized. In order to provide a fresh perspective, this thesis examines the sonic Othering of Indian music in hip-hop and reggaeton, with a key focus on cultural appropriation discourse and Orientalism in a globalised age. These genres make for an ideal study not only due to a proclivity for sampling and interpolations (the reuse of portions of existing musical works), but also the increased interest of American producers in Indian sounds through the 2000s. In addition to drawing from academic theory, music industry journalism, copyright law, and original interviews, this thesis comprises case studies examining 2000s hip-hop and reggaeton works through concepts of cultural exchange, exploitation, dominance, and transculturation. My goal in this process is to explore the scope for cultural appropriation whilst acknowledging the possibility for both exploitation and exchange, thereby driving the debate forward. Through these studies, I observe both overt and inferred forms of appropriation. Moreover, certain works exhibit a paradoxical duality, demonstrating elements of appropriation and exchange through hybridised identities. These findings enhance our understanding of not only the scope for intercultural exchange amongst postcolonial cultures, but also the role of sampling and interpolations in lending or denying subordinated cultures agency. Additionally, I identify new mediums of appropriation such as ‘brownfishing’ (the South Asian equivalent of blackfishing) as well as resistance (such as versioning and signifying politics by Indian artists), and examine the role of self-exoticisation in reclaiming sonic agency

    Crystal structure of isobutyl 4-(2-chloro-phenyl)-5-cyano-6-{(E)-[(dimethylamino)-methylidene]amino}-2-methyl-4H-pyran-3-carboxylate

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    The authors thank Dr Babu Varghese, Senior Scientific Officer SAIF, IIT Madras, India, for carrying out the data collection.Peer reviewedPublisher PD

    Measurement of the emission spectrum of a semiconductor laser using laser-feedback interferometry

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    The effects of optical feedback (OF) in lasers have been observed since the early days of laser development. While OF can result in undesirable and unpredictable operation in laser systems, it can also cause measurable perturbations to the operating parameters, which can be harnessed for metrological purposes. In this work we exploit this ‘self-mixing’ effect to infer the emission spectrum of a semiconductor laser using a laser-feedback interferometer, in which the terminal voltage of the laser is used to coherently sample the reinjected field. We demonstrate this approach using a terahertz frequency quantum cascade laser operating in both single- and multiple-longitudinal mode regimes, and are able to resolve spectral features not reliably resolved using traditional Fourier transform spectroscopy. We also investigate quantitatively the frequency perturbation of individual laser modes under OF, and find excellent agreement with predictions of the excess phase equation central to the theory of lasers under OF

    Fluctuation spectrum of fluid membranes coupled to an elastic meshwork: jump of the effective surface tension at the mesh size

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    We identify a class of composite membranes: fluid bilayers coupled to an elastic meshwork, that are such that the meshwork's energy is a function Fel[Aξ]F_\mathrm{el}[A_\xi] \textit{not} of the real microscopic membrane area AA, but of a \textit{smoothed} membrane's area AξA_\xi, which corresponds to the area of the membrane coarse-grained at the mesh size ξ\xi. We show that the meshwork modifies the membrane tension σ\sigma both below and above the scale ξ\xi, inducing a tension-jump Δσ=dFel/dAξ\Delta\sigma=dF_\mathrm{el}/dA_\xi. The predictions of our model account for the fluctuation spectrum of red blood cells membranes coupled to their cytoskeleton. Our results indicate that the cytoskeleton might be under extensional stress, which would provide a means to regulate available membrane area. We also predict an observable tension jump for membranes decorated with polymer "brushes"

    Assignment of the Human and Mouse Prion Protein Genes to Homologous Chromosomes

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    Purified preparations of scrapie prions contain one major macromolecule, designated prion protein (PrP). Genes encoding PrP are found in normal animals and humans but not within the infectious particles. The PrP gene was assigned to human chromosome 20 and the corresponding mouse chromosome 2 using somatic cell hybrids. In situ hybridization studies mapped the human PrP gene to band 20p12→pter. Our results should lead to studies of genetic loci syntenic with the PrP gene, which may play a role in the pathogenesis of prion diseases or other degenerative neurologic disorders

    Welding Studies on a Near-alpha Titanium Alloy

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    The mechanical properties and microstructures of electron beam and friction welds of a near-alpha titanium alloy IMI 834 (presently TIMET 834) have been evaluated. Electron beam welds that contain micro pores and friction welds are free from such solidification-related defects. Porosity index in electron beam welds shows a decreasing trend with an increase in the welding speed. Electron beam welds contain coarse prior β grains and fine transformed β microstructure while, friction welds contain fine prior β grains and coarse transformed β microstructure. Electron beam welds with fine transformed β microstructure exhibited higher strength as compared to friction welds with coarse transformed β microstructure. The impact toughness of both the welds is comparable. Drastic reduction in impact toughness was observed when the welds were subjected to post-weld ageing as a result of inter-lath precipitation. Coarse-grained electron beam welds exhibited better creep and stress rupture properties as compared to friction welds.Defence Science Journal, 2011, 61(6), pp.590-596, DOI:http://dx.doi.org/10.14429/dsj.61.64

    The mitochondrial genome of Parascaris univalens - implications for a “forgotten” parasite

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    © Jabbar et al.; licensee BioMed Central Ltd. 2014 This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The file attached is the Published/publisher’s pdf version of the article

    cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

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    Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE) that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites

    Cooling Ability-based Integrated Quality of Laser-drilled Holes

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    Research aimed at improving the end-product quality in meeting the functional needs isimperative to sustain product development. Aerospace manufacturers are increasingly usingpercussion laser drilling for producing cooling holes in turbine components made of nickel basesuperalloys. Laser drilling of superalloys has been initiated at the Defence Metallurgical ResearchLaboratory, Hyderabad in the last decade keeping in view its uses in Kaveri Gas Turbine Engineprogramme. Considerable.work has been carried out in this direction. Laser-drilled hole's qualityissue has been addressed in the past considering separately the shape, precision, and functionalcharacteristics of the laser-drilled holes. In the present investigation, a newer approach for defininghole quality has been reported which takes into account the above hole characteristics forcomputing cooling ability of the holes. This approach indicates that it is feasible to producebetter integrated quality holes through laser drilling
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