Constraints on the Growth and Spin of the Supermassive Black Hole in M32 From High Cadence Visible Light Observations

We present 1-second cadence observations of M32 (NGC221) with the CHIMERA instrument at the Hale 200-inch telescope of the Palomar Observatory. Using field stars as a baseline for relative photometry, we are able to construct a light curve of the nucleus in the g-prime and r-prime band with 1sigma=36 milli-mag photometric stability. We derive a temporal power spectrum for the nucleus and find no evidence for a time-variable signal above the noise as would be expected if the nuclear black hole were accreting gas. Thus, we are unable to constrain the spin of the black hole although future work will use this powerful instrument to target more actively accreting black holes. Given the black hole mass of (2.5+/-0.5)*10^6 Msun inferred from stellar kinematics, the absence of a contribution from a nuclear time-variable signal places an upper limit on the accretion rate which is 4.6*10^{-8} of the Eddington rate, a factor of two more stringent than past upper limits from HST. The low mass of the black hole despite the high stellar density suggests that the gas liberated by stellar interactions was primarily at early cosmic times when the low-mass black hole had a small Eddington luminosity. This is at least partly driven by a top-heavy stellar initial mass function at early cosmic times which is an efficient producer of stellar mass black holes. The implication is that supermassive black holes likely arise from seeds formed through the coalescence of 3-100 Msun mass black holes that then accrete gas produced through stellar interaction processes.Comment: 8 pages, 3 figures, submitted to the Astrophysical Journal, comments welcom

Analysis of plant growth promoting potential of endophytes isolated from echinacea purpurea and lonicera japonica

Plant endophytes help in maintaining plant health by means of their biofertilizer and biocontrol attributes and, are currently being explored for their ability to produce novel biologically active compounds. Herein, we have isolated beneficial endophytic bacteria from Echinacea purpurea (EF.B3) and Lonicera japonica (LS.B11) that showed phosphate solubilization, siderophore, indole acetic acid and hydrogen cyanide production, and fixation of atmospheric nitrogen. Additionally, the endophytes also conferred antifungal activity against Fusarium sp., Rhizoctonia sp., Pythium sp. and Alternaria sp. When tested in plantae, the LS.B11 and EF.B3 strains were able to promote plant growth and control fungal infections in peaseedlings. Both strains were found to be endophytic as tested by RAPD and viability count. Based on 16S rRNA gene sequencing, we show that the LS.B11 and EF.B3 strains are related to Pseudomonas sp. And Burkholderia sp. By using degenerate primers, we identified genes related to polyketide synthases and non-ribosomal peptide synthetases in EF.B3 and LS.B11, respectively that are typically involved in the production of antimicrobial compounds. Therefore, we conclude that both endophytes can be used for increasing agriculture productivity and in the production of antimicrobial compounds for crop improvement

Induction of Mutation in Rough Lemon (Citrus jambhiri Lush.) Using Gamma Rays

The present investigation was carried out to study variability induced by gamma rays with respect to vegetative characters and LD50 dose in Rough lemon. Rough lemon seeds were gamma irradiated at doses of 0, 4, 6 and 8 kr along with control. Seed germination decreased with increasing dose of gamma radiation. Seedling height and leaf size also decreased with increasing dose of gamma radiation, whereas, apical branching, number of branches/seedling, number of variegated / albino seedlings and number of leaves increased with increasing dose of gamma radiation. Maximum variability for seedling height, number of leaves, leaf size, colour, internode length, and per cent apical branching was observed at two months from sowing in seeds treated with 8 kr dose of gamma radiation. Variability for all characters was, however, found to be minimum in the control

Identification of Microbial Population during Oil Palm Frond (OPF) Composting using Light and Scanning Electron Microscopy

This investigation highlights the activity and diversity of fungal population observed on oil palm fronds (OPF) during composting process employing Scanning Electron Microscope (SEM) and conventional identification methods. Composting is a controlled biological decomposition process, which converts organic wastes into humus-like material. It is a process that involves microbial degradation of complex organic materials under moist, self-heating and aerobic conditions; and characterized by a succession of various microbial populations. Two white rot fungi species were introduced as inoculant, namely Trametes versicolor and Schizophyllum commune. The main objective for inoculation was to shorten the composting period and produce high quality compost. In this study, the oil palm fronds (OPF) were composted for 14 weeks, with four treatment; i) control (untreated OPF), ii) OPF treated with T. versicolor, iii) OPF treated with S. commune, iv) OPF treated with both T. versicolor and S. commune, and four replicates for each. A total of eight genera of fungi namely Aspergillus, Trichoderma, Absidia, Geotrichum, Trametes, Schizophyllum, Syncephalastrum and Beauveria species were isolated and identified from composted OPF. Although T. versicolor and S. commune were introduced as accelerating agents, the presence of other fungal species perhaps occurred due to the indigenous microflora that already existed on OPF, leading  to a succession of various fungi species based on the complexity of biological process in composting substrate. Keywords: Composting, oil palm frond, white-rot fungi, inoculants, Trametes versicolor, Schizophyllum commune ABSTRAKKajian ini menumpukan kepada aktiviti dan kepelbagaian populasi kulat yang terdapat pada pelepah sawit sepanjang tempoh pengkomposan, dengan menggunakan Mikroskop Elektron Pengimbas (SEM) dan teknik identifikasi konvensional. Pengkomposan merupakan proses penguraian biologi terkawal, yang menukarkan sisa organik kepada bahan-seperti-humus. Ia adalah suatu proses yang melibatkan penguraian mikrob terhadap bahan organik kompleks dalam keadaan lembap, pemanasan-diri dan aerobik; dan proses ini dicirikan oleh sesaran pelbagai jenis populasi mikrob. Dua spesies kulat pereput putih iaitu Trametes versicolor dan Schizophyllum commune telah diperkenalkan sebagai inokula dalam pengkomposan pelepah sawit. Objektif utama inokulasi adalah untuk memendekkan tempoh pengkomposan dan menghasilkan kompos berkualiti tinggi. Dalam kajian ini, pelepah sawit dikomposkan selama 14 minggu, dengan empat rawatan yang digunakan iaitu; i) kawalan (pelepah tidak dirawat), ii) pelepah dirawat dengan T. versicolor, iii) pelepah dirawat dengan S. commune, iv) pelepah dirawat dengan T. versicolor dan S. commune, dengan empat replikasi. Secara keseluruhannya, terdapat lapan genus kulat, iaitu Aspergillus, Trichoderma, Absidia, Geotrichum, Trametes, Schizophyllum, Syncephalastrum dan Beauveria telah diasingkan dan dikenalpasti dalam kompos pelepah sawit. Walaupun T. versicolor dan S. commune telah diperkenalkan sebagai agen pecutan, kehadiran pelbagai populasi kulat lain mungkin dipengaruhi oleh mikroflora semulajadi yang hadir dalam substrat pengkomposan, serta proses sesaran pelbagai spesies kulat yang bergantung kepada proses biologi kompleks yang berlaku dalam substrat pengkomposan.  Kata kunci: Pengkomposan, pelepah sawit, kulat pereput putih, inokula, Trametes versicolor, Schizophyllum commun

Coexistence of Bloch electrons and glassy electrons in Ca10(Ir4As8)(Fe2_xIrxAs2)5 revealed by angle-resolved photoemission spectroscopy

Angle-resolved photoemission spectroscopy of Ca10(Ir4As8)(Fe2_xIrxAs2)5 shows that the Fe 3d electrons in the FeAs layer form the hole-like Fermi pocket at the zone center and the electron-like Fermi pockets at the zone corners as commonly seen in various Fe-based superconductors. The FeAs layer is heavily electron doped and has relatively good two dimensionality. On the other hand, the Ir 5d electrons are metallic and glassy probably due to atomic disorder related to the Ir 5d orbital instability. Ca10(Ir4As8)(Fe2_xIrxAs2)5 exhibits a unique electronic state where the Bloch electrons in the FeAs layer coexist with the glassy electrons in the Ir4As8 layer.Comment: 4 pages, 3 figure

Orbital Degeneracy and Peierls Instability in Triangular Lattice Superconductor Ir1−x_{1-x}Ptx_xTe2_2

We have studied electronic structure of triangular lattice Ir$_{1-x}$Pt$_x$Te$_2$ superconductor using photoemission spectroscopy and model calculations. Ir $4f$ core-level photoemission spectra show that Ir $5d$ $t_{2g}$ charge modulation established in the low temperature phase of IrTe$_2$ is suppressed by Pt doping. This observation indicates that the suppression of charge modulation is related to the emergence of superconductivity. Valence-band photoemission spectra of IrTe$_2$ suggest that the Ir $5d$ charge modulation is accompanied by Ir $5d$ orbital reconstruction. Based on the photoemission results and model calculations, we argue that the orbitally-induced Peierls effect governs the charge and orbital instability in the Ir$_{1-x}$Pt$_x$Te$_2$.Comment: 5 pages,4 figure

Cosmology with decaying tachyon matter

We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show that, under certain conditions, the scale factor represents an accelerating universe, following a phase of decelerated expansion. We make use of a model of dark energy (with p=-\rho) and dark matter (p=0) where a single scalar field (tachyon) governs the dynamics of both the dark components. We show that this model fits the current supernova data as well as the canonical \LambdaCDM model. We give the bounds on the parameters allowed by the current data.Comment: 14 pages, 6 figures, v2, Discussions and references addede

Measurement of Elastic Moduli in Ceramic Composites as a Function fo Porosity Content

Longitudinal and transverse ultrasonic velocity measurements were made to obtain elastic moduli of ceramic compacts and continuous fiber ceramic composites (CMCC) as a function of porosity volume fraction. The ceramic compacts were hot pressed silicon carbide and the CMCC were Nicalon fiber reinforced silicon carbide, manufactured using a forced chemical vapor infiltration (FCVI) process developed at Oak Ridge National Laboratory [1]. The purpose of the SiC powder compact study was to obtain experimental results of elastic moduli for various porosity level and to compare the measured results with predictions based on theoretical models. For chemical vapor infiltrated Nicalon/SiC ceramic composites, elastic constants data at different porosity level were not readily available in the literature. The purpose of the study was therefore to generate a more complete set of modulus data as a function of void content. These results can be used for the optimization of the manufacturing process and for comparison with mechanical testing results