Population dynamics of cobia Rachycentron canadum (Linnaeus, 1766) off Cochin coast, south-eastern Arabian Sea

Estimated landings of cobia from the Indian EEZ by the commercial fishing vessels are mostly as bycatch in hooks and line cum gillnet and trawl nets. However, the catches are substantial compared to that reported in several other countries of Asia. The species is also gaining considerable importance as a favoured candidate species for sea farming using cages. Very little is known about the fishery and biological characters such as maturation, fecundity and feeding preferences of cobia in Indian seas. Study indicated a fast growth rate with estimates of L∞ = 184 cm (FL) and K = 2.6 (yr-1) in cobia. The total mortality rate (Z) was estimated as 5.18, natural mortality (M) was 2.01 and fishing mortality (F) was 3.17 with an exploitation rate (E) of 0.61. The length at first capture (Lc50) estimated from the catch curve was 72 cm. Fecundity was found to be high and variable, with mean fecundity estimated as 12,37,545 eggs with a coefficient of variation (CV) of 16.7. As inferred from the oocyte development pattern, spawning activity is brief and fish is classified as synchronous ovulatory type. The growth parameters and condition factor estimated in this study indicate that relatively high growth rates are also possible in wild stocks considering that food is abundant and the environmental temperature is in the optimum range. Feeding preferences indicated balistid fish and shrimps with a wide variety of food items including finfishes, crustaceans and molluscs present

Fermented brewers’ spent grain containing dextran and oligosaccharides as ingredient for composite wheat bread and its impact on gut metabolome in vitro

Brewers’ spent grain or BSG is a fiber and protein rich food-grade side stream that has remained underutilized due to its poor technological and sensory characteristics. In this study, BSG was fermented with Weissella confusa A16 in presence of sucrose to induce the synthesis of dextran and maltosyl-isomaltooligosaccharides. Fermented BSG with or without the above polysaccharides was used as ingredient in wheat bread. Digestion of BSG breads was simulated in vitro with Simulator of Human Intestinal Microbial Ecosystem, and levels of fecal metabolites were analyzed. Enrichment of BSG breads with in situ dextran and maltosyl-isomaltooligosaccharides improved the baking quality compared to native BSG. Metabolism of free amino acids and synthesis of short chain fatty acids varied at different stages and parts of colon. The increase in butyric acid was similar in both the proximal and distal colon. In situ dextran and maltosyl-isomaltooligosaccharides, and higher content of proteins and fiber in BSG breads had a positive influence towards gut microbiota functionality. Along with several essential amino acids, an increase in amount of γ-aminobutyric acid was also observed after simulated digestion. BSG breads had a significant effect on the gut metabolome during in vitro digestion, showing increased production of microbial metabolites with potential health benefits

Spin-Peierls instability in a quantum spin chain with Dzyaloshinskii-Moriya interaction

We analysed the ground state energy of some dimerized spin-1/2 transverse XX and Heisenberg chains with Dzyaloshinskii-Moriya (DM) interaction to study the influence of the latter interaction on the spin-Peierls instability. We found that DM interaction may act either in favour of the dimerization or against it. The actual result depends on the dependence of DM interaction on the distortion amplitude in comparison with such dependence for the isotropic exchange interaction.Comment: 12 pages, latex, 3 figure

Oil sardine from Oman enter fish markets of Kerala

The Oil sardine Sardinella longiceps is a major fishery resource in India and catches in 2014 were an estimated 5.44 lakh tonnes (t). Of this, Kerala accounted for 1.55 lakh t forming 28% of the All India Oil sardine landings. In the domestic retail markets of Kerala when Oil sardine prices were ranging between ` 80 - 140 per kilogram, large sized sardines with average weights > 120 g each were also appearing and being sold at prices 40 - 60% higher than the locally caught sardines. Although market sources informed that these large sized Oil sardine were coming from Oman, the claim could not be traced. However, during a weekly visit to Kalamukku landing centre, Kochi for sampling fish on 23.6.2015, the unloading of packed cartons containing large sized Oil sardine was observed and these were traced to being sourced from Oman

Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure

Temperature dependent extended x-ray absorption fine structure (EXAFS) spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20 - 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence of the pair-distance distribution widths, \sigma(T) was accurately modeled using a correlated-Debye model for the lattice vibrational properties, suggesting Debye-like behavior in this material. We obtain pair- specific correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7 K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the first unambiguous determination of Ga-specific vibrational properties in PuGa alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu bonds. This effect has important implications for lattice stabilization mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres

Frustration induced Raman scattering in CuGeO_3

We present experimental data for the Raman intensity in the spin-Peierls compound CuGeO_3 and theoretical calculations from a one-dimensional frustrated spin model. The theory is based on (a) exact diagonalization and (b) a recently developed solitonic mean field theory. We find good agreement between the 1D-theory in the homogeneous phase and evidence for a novel dimerization of the Raman operator in the spin-Peierls state. Finally we present evidence for a coupling between the interchain exchange, the spin-Peierls order parameter and the magnetic excitations along the chains.Comment: Phys. Rev. B, Rapid Comm, in Pres

Lattice dynamics and correlated atomic motion from the atomic pair distribution function

The mean-square relative displacements (MSRD) of atomic pair motions in crystals are studied as a function of pair distance and temperature using the atomic pair distribution function (PDF). The effects of the lattice vibrations on the PDF peak widths are modelled using both a multi-parameter Born von-Karman (BvK) force model and a single-parameter Debye model. These results are compared to experimentally determined PDFs. We find that the near-neighbor atomic motions are strongly correlated, and that the extent of this correlation depends both on the interatomic interactions and crystal structure. These results suggest that proper account of the lattice vibrational effects on the PDF peak width is important in extracting information on static disorder in a disordered system such as an alloy. Good agreement is obtained between the BvK model calculations of PDF peak widths and the experimentally determined peak widths. The Debye model successfully explains the average, though not detailed, natures of the MSRD of atomic pair motion with just one parameter. Also the temperature dependence of the Debye model largely agrees with the BvK model predictions. Therefore, the Debye model provides a simple description of the effects of lattice vibrations on the PDF peak widths.Comment: 9 pages, 11 figure

Further studies on the physics potential of an experiment using LHC neutrinos

We discuss an experiment to investigate neutrino physics at the LHC, with emphasis on tau flavour. As described in our previous paper Beni et al (2019 J. Phys. G: Nucl. Part. Phys. 46 115008), the detector can be installed in the decommissioned TI18 tunnel, ≈ 480 m downstream the ATLAS cavern, after the first bending dipoles of the LHC arc. The detector intercepts the intense neutrino flux, generated by the LHC beams colliding in IP1, at large pseudorapidity η, where neutrino energies can exceed a TeV. This paper focuses on exploring the neutrino pseudorapity versus energy phase space available in TI18 in order to optimize the detector location and acceptance for neutrinos originating at the pp interaction point, in contrast to neutrinos from pion and kaon decays. The studies are based on the comparison of simulated pp collisions at √s = 13 TeV: PYTHIA events of heavy quark (c and b) production, compared to DPMJET minimum bias events (including charm) with produced particles traced through realistic LHC optics with FLUKA. Our studies favour a configuration where the detector is positioned off the beam axis, slightly above the ideal prolongation of the LHC beam from the straight section, covering 7.4 < η < 9.2. In this configuration, the flux at high energies (0.5-1.5 TeV and beyond) is found to be dominated by neutrinos originating directly from IP1, mostly from charm decays, of which ∼50% are electron neutrinos and ∼5% are tau neutrinos. The contribution of pion and kaon decays to the muon neutrino flux is found small at those high energies. With 150 f b-1 of delivered LHC luminosity in Run 3 the experiment can record a few thousand very high energy neutrino charged current (CC) interactions and over 50 tau neutrino CC events. These events provide useful information in view of a high statistics experiment at HL-LHC. The electron and muon neutrino samples can extend the knowledge of the charm PDF to a new region of x, which is dominated by theory uncertainties. The tau neutrino sample can provide first experience on reconstruction of tau neutrino events in a very boosted regime

Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade

The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE