First record of Polka-dot ribbonfish Desmodema polystictum (Pisces: Trachipteridae) from Indian waters

Polka-dot ribbonfish Desmodema polystictum was recorded for the first time from Indian waters. A single specimen of D. polystictum (107 cm total length and weighing 480 g) was collected from Tharuvaikulam landing centre, north to Tuticorin, on the south-east coast of India during September 2010. The distinguishing characters of the species from other species of the family are discussed. Morphometric and meristic characters of D. polystictum are presented in this paper. With the present report, the distribution area of this species now extends to the Indian waters

Three-fold way to extinction in populations of cyclically competing species

Species extinction occurs regularly and unavoidably in ecological systems. The time scales for extinction can broadly vary and inform on the ecosystem's stability. We study the spatio-temporal extinction dynamics of a paradigmatic population model where three species exhibit cyclic competition. The cyclic dynamics reflects the non-equilibrium nature of the species interactions. While previous work focusses on the coarsening process as a mechanism that drives the system to extinction, we found that unexpectedly the dynamics to extinction is much richer. We observed three different types of dynamics. In addition to coarsening, in the evolutionary relevant limit of large times, oscillating traveling waves and heteroclinic orbits play a dominant role. The weight of the different processes depends on the degree of mixing and the system size. By analytical arguments and extensive numerical simulations we provide the full characteristics of scenarios leading to extinction in one of the most surprising models of ecology

Cu K-absorption edge study of cuprate superconductors

Cu K-absorption edges of YBa2Cu3O6.9, Tl2CaBa2Cu2O8 and Bi2CaSr2Cu2O8 show similar features. Copper is mainly in the 2+ state in these cuprates suggesting the likely presence of oxygen holes

Sharptail mola landed at Thoothukudi

A large Sharptail mola (Masturus lanceolatus) measuring 180 cm in Total length (TL) landed on 28.07.2016 at Tharuvaikulam Landing Centre, Gulf of Mannar. Interaction with the local fishermen indicated that it was caught at a depth of 150 m in a drift gill net conducting multiday fishing for 4-5 days about 40 km from shore

New Record of Satyrichthys milleri Kawai, 2013 (Peristediidae) From Gulf of Mannar, Bay of Bengal

A specimen of Satyrichthys milleri Kawai, 2013 with the standard length of 221 mm was collected from Tuticorin fishing harbour, south east coast of India on 23rd October 2014. It was collected by bottom trawlers at a depth ranges from 200-250 m. This is the first attempt to provide a detailed description of the species from the Gulf of Mannar. This record was compared with the first reported specimen in order to compare the external morphology with known specimen. The present study constitutes an extension of the known distributional range of this species from the Andaman to the Gulf of Mannar

First record of Pyramodon lindas (Markle and Olney, 1990) (Ophidiforms: Carapidae) from Indian Seas

Background: The present report is the first record of the Pyramodon lindas (Markle and Olney, Bull Mar Sci 47: 269-410, 1990) from India waters. A specimen of Pyramodon lindas measuring 483 mm total length was obtained from Tuticorin of Gulf of Mannar which is the largest specimen of so far recorded. Results: The Pyramodon lindas measured 483 mm in TL, 85 mm in Head length, 18.1 mm in snout length. Body elongate, compressed to round and eel like, supramaxilla absent, anal fin origin advanced. The specimen was deposited in the National Biodiversity Museum at the Central Marine Fisheries Research Institute, Kochi (GB.28.3.3.1) Detailed mophometric and meristic characters described and discussed. Conclusion: The Pyramodon lindas reported in the present study makes the total species reported from India as four in family Carapidae. The other reports were Carapus homei (Richardson, 1846), Pyramodon punctatum (Regan, 1914), Carapus margaritiferae (Rendahl, 1921) Brotula multibarbata Temmink & Schlegel, 1846 Antennarius hispidus (Bloch & Schneider, 1801)

Lattice-point enumerators of ellipsoids

Minkowski's second theorem on successive minima asserts that the volume of a 0-symmetric convex body K over the covolume of a lattice \Lambda can be bounded above by a quantity involving all the successive minima of K with respect to \Lambda. We will prove here that the number of lattice points inside K can also accept an upper bound of roughly the same size, in the special case where K is an ellipsoid. Whether this is also true for all K unconditionally is an open problem, but there is reasonable hope that the inductive approach used for ellipsoids could be extended to all cases.Comment: 9 page

Detecting and Characterizing Small Dense Bipartite-like Subgraphs by the Bipartiteness Ratio Measure

We study the problem of finding and characterizing subgraphs with small \textit{bipartiteness ratio}. We give a bicriteria approximation algorithm \verb|SwpDB| such that if there exists a subset $S$ of volume at most $k$ and bipartiteness ratio $\theta$, then for any $0<\epsilon<1/2$, it finds a set $S'$ of volume at most $2k^{1+\epsilon}$ and bipartiteness ratio at most $4\sqrt{\theta/\epsilon}$. By combining a truncation operation, we give a local algorithm \verb|LocDB|, which has asymptotically the same approximation guarantee as the algorithm \verb|SwpDB| on both the volume and bipartiteness ratio of the output set, and runs in time $O(\epsilon^2\theta^{-2}k^{1+\epsilon}\ln^3k)$, independent of the size of the graph. Finally, we give a spectral characterization of the small dense bipartite-like subgraphs by using the $k$th \textit{largest} eigenvalue of the Laplacian of the graph.Comment: 17 pages; ISAAC 201

Detection of Landmine Signature using SAW-based Polymer-coated Chemical Sensor

The explosive charge within a landmine is the source for a mixture of chemical vapours that form a distinctive chemical signature indicative of a landmine. The concentrations of these compounds in the air over landmines is extremely low (parts-per-trillion or lower), well below the minimum detection limits of most field-portable chemical sensors. This paper describes a portable  surface acoustic wave-based polymer-coated sensor for the detection of hidden explosives. The sensitivity and selectivity of polymer-based sensors depend on several factors including the chemo-selective coating used, the physical properties of the vapour(s) of interest, the selected transducers, and the operating conditions. The polymer-based sensor was calibrated in the  laboratory using the explosive vapour generator. The preliminary results indicated that the carbowax 1000 could be a very good chemical interface to sense low levels of chemical signature of explosive material. Response for 50 ppb of TNT vapours was observed to be 400 Hz for an exposure of 2 min