An Upstream Hfq Binding Site in the fhlA mRNA Leader Region Facilitates the OxyS-fhlA Interaction

To survive, bacteria must be able to adapt to environmental stresses. Small regulatory RNAs have been implicated as intermediates in a variety of stress-response pathways allowing dynamic gene regulation. The RNA binding protein Hfq facilitates this process in many cases, helping sRNAs base pair with their target mRNAs and initiate gene regulation. Although Hfq has been identified as a critical component in many RNPs, the manner by which Hfq controls these interactions is not known.To test the requirement of Hfq in these mRNA-sRNA complexes, the OxyS-fhlA system was used as a model. OxyS is induced in response to oxidative stress and down regulates the translation of fhlA, a gene encoding a transcriptional activator for formate metabolism. Biophysical characterization of this system previously used a minimal construct of the fhlA mRNA which inadvertently removed a critical element within the leader sequence of this mRNA that effected thermodynamics and kinetics for the interaction with Hfq.Herein, we report thermodynamic, kinetic and structural mapping studies during binary and ternary complex formation between Hfq, OxyS and fhlA mRNA. Hfq binds fhlA mRNA using both the proximal and distal surfaces and stimulates association kinetics between the sRNA and mRNA but remains bound to fhlA forming a ternary complex. The upstream Hfq binding element within fhlA is similar to (ARN)(x) elements recently identified in other mRNAs regulated by Hfq. This work leads to a kinetic model for the dynamics of these complexes and the regulation of gene expression by bacterial sRNAs

Deep UV Luminosity Functions at the Infall Region of the Coma Cluster

We have used deep GALEX observations at the infall region of the Coma cluster to measure the faintest UV luminosity functions (LFs) presented for a rich galaxy cluster thus far. The Coma UV LFs are measured to M_UV = -10.5 in the GALEX FUV and NUV bands, or 3.5 mag fainter than previous studies, and reach the dwarf early-type galaxy population in Coma for the first time. The Schechter faint-end slopes (alpha = -1.39 in both GALEX bands) are shallower than reported in previous Coma UV LF studies owing to a flatter LF at faint magnitudes. A Gaussian-plus-Schechter model provides a slightly better parametrization of the UV LFs resulting in a faint-end slope of ~ -1.15 in both GALEX bands. The two-component model gives faint-end slopes shallower than -1 (a turnover) for the LFs constructed separately for passive and star forming galaxies. The UV LFs for star forming galaxies show a turnover at M_UV ~ -14 owing to a deficit of dwarf star forming galaxies in Coma with stellar masses below M*=10^8 Msun. A similar turnover is identified in recent UV LFs measured for the Virgo cluster suggesting this may be a common feature of local galaxy clusters, whereas the field UV LFs continue to rise at faint magnitudes. We did not identify an excess of passive galaxies as would be expected if the missing dwarf star forming galaxies were quenched inside the cluster. In fact, the LFs for both dwarf passive and star forming galaxies show the same turnover at faint magnitudes. We discuss the possible origin of the missing dwarf star forming galaxies in Coma and their expected properties based on comparisons to local field galaxies.Comment: accepted for publication in Ap

Horizontal axis wind turbine performance analysis

The present work uses the method of Blade Element Momentum Theory as suggested by Hansen. The method applied to three blade models adopted from Rahgozar S. with the airfoil data used the data provided by Wood D. The wind turbine performance described in term of the thrust coefficient CT, torque coefficient CQ and the power coefficient Cp . These three coefficient can be deduced from the Momentum theory or from the Blade element Theory(BET). The present work found the performance coefficient derived from the Momentum theory tent to over estimate. It is suggested to used the BET formulation in presenting these three coefficients. In overall the Blade Element Momentum Theory follows the step by step as described by Hansen work well for these three blade models. However a little adjustment on the blade data is needed. To the case of two bladed horizontal axis wind turbine, Hansen’s approach works well over if the blade radius is RB the calculation should start from r = 0.1RB

Coral Reef Spatial Distribution in Wangi-wangi Island Waters, Wakatobi

Coral reefs contribute significant benefits in coastal area in Wangi-wangi Island, Wakatobi in terms of their ecological functions to marine biota and socio-economical services to local coastal communities. Therefore, it is importance to observe coral reef condition and its spatial distribution around Wangi-wangi island waters, Wakatobi. In this study Point Intercept Transect (PIT) and GIS tools were used to observe and analyze coral reef condition in Wangi-wangi island waters, Wakatobi. The results showed that coral reef condition in Wangi-wangi island waters can be categorized into moderate and good conditions with coverage percentage ranging from 28 – 60%. Based on spatial analysis non-acropora coral was found in greater cover percentages in Waha village, Sombu village, and Kapota island than other locations. Soft coral cover percentage was also found in larger cover percentage in Waha and Sombu regions than other locations

String Propagation in Bianchi Type I models: Dynamical anisotropy Damping and Consequences

A generic ansatz is introduced which provides families of exact solutions to the equations of motion and constraints for null-strings in Bianchi type I cosmological models. This is achieved irrespective of the form of the metric. Within classes of dilaton cosmologies a backreaction mapping relation is established where the null string leads to more or less anisotropic members of the family. The equations of motion and constraints for the generic model are casted in their first order form and integrated both analytically and numerically.Comment: 37 pages, 11 figure

Host galaxy colour gradients and accretion disc obscuration in AEGIS z~1 X-ray-selected active galactic nuclei

We describe the effect of AGN light on host galaxy optical and UV-optical colours, as determined from X-ray-selected AGN host galaxies at z~1, and compare the AGN host galaxy colours to those of a control sample matched to the AGN sample in both redshift and stellar mass. We identify as X-ray-selected AGNs 8.7 +4/-3 per cent of the red-sequence control galaxies, 9.8 +/-3 per cent of the blue-cloud control galaxies, and 14.7 +4/-3 per cent of the green-valley control galaxies. The nuclear colours of AGN hosts are generally bluer than their outer colours, while the control galaxies exhibit redder nuclei. AGNs in blue-cloud host galaxies experience less X-ray obscuration, while AGNs in red-sequence hosts have more, which is the reverse of what is expected from general considerations of the interstellar medium. Outer and integrated colours of AGN hosts generally agree with the control galaxies, regardless of X-ray obscuration, but the nuclear colours of unobscured AGNs are typically much bluer, especially for X-ray luminous objects. Visible point sources are seen in many of these, indicating that the nuclear colours have been contaminated by AGN light and that obscuration of the X-ray radiation and visible light are therefore highly correlated. Red AGN hosts are typically slightly bluer than red-sequence control galaxies, which suggests that their stellar populations are slightly younger. We compare these colour data to current models of AGN formation. The unexpected trend of less X-ray obscuration in blue-cloud galaxies and more in red-sequence galaxies is problematic for all AGN feedback models, in which gas and dust is thought to be removed as star formation shuts down. [See paper for full abstract.]Comment: Accepted to MNRAS. 19 pages, 14 figures, 1 table; table, four figures (4, 6, 11, 13) revised to reflect corrected values for one of our objects; results unchange

Large-scale magnetic fields from inflation due to Chern-Simons-like effective interaction

We discuss the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the $CPT$-even dimension-six Chern-Simons-like effective interaction with a fermion current in inflationary cosmology. It is shown that the magnetic fields on 1Mpc scale with the field strength of $\sim 10^{-9}$G at the present time can be generated even for the scale of the effective interaction being the Planck scale.Comment: 13 pages, 2 figures, additional explanations include

Mid-IR Luminosities and UV/Optical Star Formation Rates at z<1.4

UV continuum and mid-IR emission constitute two widely used star formation indicators at intermediate and high redshifts. We study 2430 galaxies with z<1.4 in the Extended Groth Strip with MIPS 24 mic observations from FIDEL, spectroscopy from DEEP2, and UV, optical, and near-IR photometry from AEGIS. The data are coupled with stellar population models and Bayesian SED fitting to estimate dust-corrected SFRs. In order to probe the dust heating from stellar populations of various ages, the derived SFRs were averaged over various timescales--from 100 Myr for "current" SFR to 1--3 Gyr for long-timescale SFRs. These SED-based UV/optical SFRs are compared to total infrared luminosities extrapolated from 24 mic observations. We find that for the blue, actively star forming galaxies the correlation between the IR luminosity and the UV/optical SFR shows a decrease in scatter when going from shorter to longer SFR-averaging timescales. We interpret this as the greater role of intermediate age stellar populations in heating the dust than what is typically assumed. This holds over the entire redshift range. Many so-called green valley galaxies are simply dust-obscured actively star-forming galaxies. However, there exist 24 mic-detected galaxies, some with L>10^11 L_sun, yet with little current star formation. For them a reasonable amount of dust absorption of stellar light is sufficient to produce the observed levels of IR. In our sample optical and X-ray AGNs do not contribute on average more than ~50% to the mid-IR luminosity, and we see no evidence for a large population of "IR excess" galaxies (Abridged).Comment: Accepted for publication in ApJ. Content identical to arXiv version 1. No color figure

Fabrication of smart glass electrochromic device using rf magnetron sputtering

Electrochromic device is an important functional device to control the amount of light through a glass. It usually used in sunlight control window glazing for buildings and automobile. The important feature of electrochromic glass is the ability to response toward the apply voltage in shortest time, and endurance to maintain in color shape after apply voltage. In this thesis, the oxygen gas percentage is optimized during the fabrication of tungsten trioxide (WO3) as an electrochromic glass for window glazing application by using RF magnetron sputtering. The oxygen flow rate for the deposition is varied from 10sccm -22sccm which is 25%, 27%, 30%, and 35% of oxygen flow. The structures of WO3 were investigated using X-Ray diffraction, Field effect scanning electron microscopy (Fe-Sem) and Atomic force microscopy (AFM). The electrochromic properties were characterized by a cyclic voltammogram and UV-Vis absorption spectra. The results show that nanocrystalline film with particle size of 51.54nm was deposited at 27% oxygen flow rate has the largest charge capacity and coloration efficiency among the others. The time respond taken for complete coloration at 4V is 2second. This result is a starting point for future work such as optimizing the film thickness or doping by other metals