224 research outputs found

    Electrophoretic and immunotaxonomic studies of three species of marine gastropods from Portonovo coast with reference to population management

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    Electrophoretic and serological studies of foot muscle protein of three species of Cerithiacea (Telescopium telescopium, Cerithidea fluviatilis and C. obtusum) were carried out to understand their relationships. Living specimens were collected from mud flats and mangrove swamps off Portonovo. Polyacrylamide electrophoresis of proteins from foot muscle extract of T. telescopium, C. fluviatilis and C. obtusum showed that the former had a different densitometric profile as well as more number of protein bands; but the later two species showed a closer related pattern as well as lesser number of protein bands. At the same time these two species are distinguished from each other in their total number of bands and Rf values. Immunological studies using micro-Ouchterlony double diffusion tests which absorbed antiserum indicated that C. fluviatilis and C. obtusum were more closely related as revealed by an identity reactions than T. telesopium as shown by non-identity reactions. Results are discussed in relation to ecological and morphological adaptation

    Biomass and composition of zooplankton in and around Gulf of Kutch

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    The faunal composition, distribution and abundance of zooplankton from 28 stations in and around the Gulf of Kutch, were studied during INS Darshak cruise in January, 1975. Zooplankton biomass was about 4.5 times more in the outside Gulf region (mean: 50.3 ml/100 m super(3)) than in the inside Gulf (mean: 11.1 ml/100 m super(3)). The mean zooplankton biomass of Dwarka (66.3 ml/100 m super(3)) was about 2.5 times more than that off Okha (26.8 ml/100 m super(3)). A rich zooplankton production in the Saurashtra waters corresponded to a rich fishery prevailing in this region

    On the stranding of sea cow Dugong dugon at Mandapam along the Gulf of Mannar coast.

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    A dead male sea cow Dugong dugon (Muller) measuring 194 cm in total length and about 125kg in weight was stranded along the Gulf of Mannar coast at Mandapam.The morphometric measurements of specimen were taken and identified to species level

    Collinear order in a frustrated three-dimensional spin-12\frac12 antiferromagnet Li2_2CuW2_2O8_8

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    Magnetic frustration in three dimensions (3D) manifests itself in the spin-12\frac12 insulator Li2_2CuW2_2O8_8. Density-functional band-structure calculations reveal a peculiar spin lattice built of triangular planes with frustrated interplane couplings. The saturation field of 29 T contrasts with the susceptibility maximum at 8.5 K and a relatively low N\'eel temperature TN3.9T_N\simeq 3.9 K. Magnetic order below TNT_N is collinear with the propagation vector (0,12,0)(0,\frac12,0) and an ordered moment of 0.65(4) μB\mu_B according to neutron diffraction data. This reduced ordered moment together with the low maximum of the magnetic specific heat (Cmax/R0.35C^{\max}/R\simeq 0.35) pinpoint strong magnetic frustration in 3D. Collinear magnetic order suggests that quantum fluctuations play crucial role in this system, where a non-collinear spiral state would be stabilized classically.Comment: published version with supplemental material merged into the tex

    SP5 - Collaborative co-creation of OER by teacher educators and teachers in India : a participatory action research study

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    15,000 teachers from 6,000 schools trained to participate in “Subject Teachers Forums (STF)” for sharing experiences and seeking ideas and resources. Afterwards, they networked with each other through subject specific google groups. Teachers share ideas, experiences and resources; mentor and seek help of peers; explore new areas of learning, and network with teacher educators and state functionaries in the STF programme. This presentation provides a review of the study as part of Research in Open Educational Resources for Development (ROER4D)

    Teacher professional learning communities : a participatory resource creation approach to OER in Karnataka

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    The presentation focuses on research in open educational resources: the techno-social context such as ICT infrastructure; the pedagogical context as in teacher development; and socio-cultural context (building community), and how these are affected by teacher participation in, and creation of OER. It reviews a survey of teachers in Karnataka (India). The use of digital methods in OER adoption helped teachers to create resources in different formats, using different editors and tools learnt in the workshops, and also to share with peers over mailing lists. OER should be made available in local languages to be contextually relevant

    Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots

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    The highest superconducting temperature Tc_c observed in any elemental metal (Li with Tc_c ~ 20 K at pressure P ~ 40 GPa) is shown to arise from critical (formally divergent) electron-phonon coupling to the transverse T1_1 phonon branch along intersections of Kohn anomaly surfaces with the Fermi surface. First principles linear response calculations of the phonon spectrum and spectral function α2F(ω)\alpha^2 F(\omega) reveal (harmonic) instability already at 25 GPa. Our results imply that the fcc phase is anharmonically stabilized in the 25-38 GPa range.Comment: 4 pages, 3 embedded figure

    Studies on the biology of the dog-whelk Nassastolata (Gmelin) of Portonovo waters

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    The morphology, anatomy and sex ratio of the mud snail Nassa stolata (Gmelin) were studied. The species, being a facultative omnivore. feeds mainly on dead animals and the digestive system is suited to this mode of feeding. The radula is of rachiglossate type and is well suited for tearing and rasping. The female reproductive system is more complicated than that of male- Studies on sex ratio clearly show the preponderance of males over females. The males mature at a size of 12.1 mm female at 12.5 mm

    Electronic and Thermoelectric Properties of RuIn_{3-x}A_{x} (A = Sn, Zn)

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    Recently, we reported [M. Wagner et al., J. Mater. Res. 26, 1886 (2011)] transport measurements on the semiconducting intermetallic system RuIn3 and its substitution derivatives RuIn_{3-x}A_{x} (A = Sn, Zn). Higher values of the thermoelectric figure of merit (zT = 0.45) compared to the parent compound were achieved by chemical substitution. Here, using density functional theory based calculations, we report on the microscopic picture behind the measured phenomenon. We show in detail that the electronic structure of the substitution variants of the intermetallic system RuIn_{3-x}A_{x} (A = Sn, Zn) changes in a rigid-band like fashion. This behavior makes possible the fine tuning of the substitution concentration to take advantage of the sharp peak-like features in the density of states of the semiconducting parent compound. Trends in the transport properties calculated using the semi-classical Boltzmann transport equations within the constant scattering time approximation are in good agreement with the former experimental results for RuIn_{3-x}Sn_{x}. Based on the calculated thermopower for the p-doped systems, we reinvestigated the Zn-substituted derivative and obtained ZnO-free RuIn_{3-x}Zn_{x}. The new experimental results are consistent with the calculated trend in thermopower and yield large zT value of 0.8.Comment: PRB Accepted, 11 pages, 10 figure
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