94 research outputs found
Tom Robotham, 25th Annual ODU Literary Festival
No full textTom Robotham is the editor of Port Folio Weekly, a news and opinion magazine serving southeastern Virginia. Before joining Port Folio in 1998, Robotham worked as a freelance writer and video producer. He is the author of five books, including a volume on the 19th century American landscape painter, Albert Bierstadt, and a book on early photographs of American Indians. Robotham holds an M.A. in American Studies from the Graduate Center of the City University of New York
Galaxy and mass assembly (GAMA) : AUTOZ spectral redshift measurements, confidence and errors
No full textThe Galaxy And Mass Assembly (GAMA) survey has obtained spectra of over 230 000 targets using the Anglo-Australian Telescope. To homogenize the redshift measurements and improve the reliability, a fully automatic redshift code was developed (AUTOZ). The measurements were made using a cross-correlation method for both the absorption-and the emission-line spectra. Large deviations in the high-pass-filtered spectra are partially clipped in order to be robust against uncorrected artefacts and to reduce the weight given to single-line matches. A single figure of merit (FOM) was developed that puts all template matches on to a similar confidence scale. The redshift confidence as a function of the FOM was fitted with a tanh function using a maximum likelihood method applied to repeat observations of targets. The method could be adapted to provide robust automatic redshifts for other large galaxy redshift surveys. For the GAMA survey, there was a substantial improvement in the reliability of assigned redshifts and in the lowering of redshift uncertainties with a median velocity uncertainty of 33 kms-1.Peer reviewe
School of Optometry: Graduating class of 1999
No full textSchool of Optometry
Final Year Students 1999
Back row: Claire Peacock, Allyson Eaton, Jayne Robotham, Renae Snape, Katie Edwards, Antonia Bigault, Mark Lloyd, Luke Arkapaw, Matt Bennett, Aaron Ko, Simon Kelly
Third row: Jasmin Geldard, Mark Stevenson, Melanie Wiseman, Tina Doan, Chris Blanch, Tony Fraser, Steven Davis, Peter Lau
Second row: Leonie Story, Anthony Mulvahil, Leith McGahey, Carolyn Drabsch, Stephen Henry, Jennifer Chen, Peter McKay, Kamaile Shirley
Front row: Joanna Wu, Lucy Hseih, Damien Fisher, David Campling, Douglas Garth
Absent: Betty Fok, Geoff Grounds, Vincent Ho, Sharon Muller, Ben Par
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Evaluation of the regioselectivity of human UDP-glucuronosyltransferase isozymes with three common sub-classes of flavonoids via metal complexation and tandem mass spectrometry
No full texttextBased on reactions with two flavanones, three flavonols, and five flavones the regioselectivities of twelve human UDP-glucuronosyltransferase (UGT) isozymes were elucidated. The various flavonoid glucuronides were differentiated based on LC-MS/MS fragmentation patterns of [Co(II)(flavonoid – H)(4,7-diphenyl-1,10-phenanthroline)2]+ complexes generated upon post-column complexation. Glucuronide distributions were evaluated to allow a systematic assessment of the regioselectivity of each isozyme. The various UGT enzymes, including eight UGT1A and four UGT2B, displayed a remarkable range of selectivities, both in terms of the positions of glucuronidation and relative reactivity with flavanones, flavonols and flavones. The UGT1A enzyme selectivities are affected by the presence of a hydroxyl group at the 3, 6, 4’, or 3’ positions as well as by the presence of a methoxy at the 3’ position. The UGT2B enzymes show poor to no reactivity with the flavonols or flavones. This result implies that the greater planarity of the flavonols and flavones compared to structure of flavanones inhibits interaction with the UGT2 enzymes. For baicalein and scutellarein, three of the UGT1A isozymes (1A8, 1A9, and 1A10) resulted in the formation of 6-O glucuronides, enabling the fragmentation rules for the metal complexation/MS/MS strategy to be expanded.Chemistr
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De novo sequencing and peptide characterization via ultraviolet photodissociation mass spectrometry
No full textAlthough in silico database search methods remain more popular for shotgun proteomics methods, de novo sequencing offers the ability to identify proteins lacking sequenced genomes and ones with subtle splice variants or truncations. Ultraviolet photodissociation (UVPD) of peptides derivatized by selective attachment of a chromophore at the N-terminus generated characteristic series of y ions. The UVPD spectra of the chromophore-labelled peptides were simplified and thus amenable to de novo sequencing. E.coli lysates were modified by the use of carbamylation and the attachment of a UV chromophore to the N-terminus of digested peptides. UVPD of the resulting peptides generated clean sets of y ions. A novel de novo algorithm, UVnovo, afforded high confidence identification of thousands of peptides from an E. coli lysate and allowed UVPD/CID paired spectra to be searched. E.coli lysate peptides were analyzed in alternating scans by UVPD and CID on the same precursors to generate paired UVPD/CID spectra. UVnovo enabled sequence tag de novo sequencing of peptides in order to find matching sequences from a database. Ultimately the UVnovo functioned as a standalone de novo sequencing program or a hybrid de novo/database search program. In an effort to better characterize the fragmentation pathways promoted by ultraviolet photoexcitation in comparison to CID, six adrenocorticotropic hormone (ACTH) peptides in a range of charge states were subjected to 266 nm ultraviolet photodissociation (UVPD), 193 nm UVPD, and CID. While both UVPD and CID led to preferential cleavage of the Y-S bond for all ACTH peptides (except ACTH (1-39)), UVPD was far less dependent on charge state and location of basic sites for the production of C-terminal and N-terminal ions.Chemistr
Vertical axis wind turbines - are we any better informed?
No full textIn the early years of the modern era of the wind turbine, experimental development of vertical axis wind turbines (VAWTs) was underpinned by an incremental improvement of aerodynamic performance prediction methods; the most advanced being the double actuator disk, multiple streamtube theory devised, quite independently, by David Sharpe in the UK and Ion Paraschivoiu in Canada. Commercially, VAWTs were not successful as the 3-bladed, pitch control horizontal axis turbine became the de facto configuration for the industry, and consequently progress in VAWT development stagnated. However, renewed interest in VAWTS has emerged, prompted by the development of small turbines for use in urban environments, e.g. the helical VAWT from quietrevolution. The objective of this paper will be to review recent third party findings and present the author’s own trade studies of the helical VAWT using the double actuator disk, multiple streamtube theory. Furthermore, initial investigations will be presented of a proprietary CFD software tool, which uses a mesh-less approach to fluid dynamics modelling that makes it an attractive option for dynamic/transient flows, moving bodies, and complex body surfaces. The author concludes that the challenges for predicting the aerodynamic performance remain the same but CFD offers substantial new insights into turbine behaviou
Vertical axis wind turbines - are we any better informed?
No full textIn the early years of the modern era of the wind turbine, experimental development of vertical axis wind turbines (VAWTs) was underpinned by an incremental improvement of aerodynamic performance prediction methods; the most advanced being the double actuator disk, multiple streamtube theory devised, quite independently, by David Sharpe in the UK and Ion Paraschivoiu in Canada. Commercially, VAWTs were not successful as the 3-bladed, pitch control horizontal axis turbine became the de facto configuration for the industry, and consequently progress in VAWT development stagnated. However, renewed interest in VAWTS has emerged, prompted by the development of small turbines for use in urban environments, e.g. the helical VAWT from quietrevolution. The objective of this paper will be to review recent third party findings and present the author’s own trade studies of the helical VAWT using the double actuator disk, multiple streamtube theory. Furthermore, initial investigations will be presented of a proprietary CFD software tool, which uses a mesh-less approach to fluid dynamics modelling that makes it an attractive option for dynamic/transient flows, moving bodies, and complex body surfaces. The author concludes that the challenges for predicting the aerodynamic performance remain the same but CFD offers substantial new insights into turbine behaviou
Galaxy and Mass Assembly (GAMA) : merging galaxies and their properties
No full textWe derive the close pair fractions and volume merger rates for galaxies in the Galaxy and Mass Assembly (GAMA) survey with -23 <M-r <-17 (Omega(M) = 0.27, Omega(A) = 0.73, H-0 = 100 km s(-1) Mpc(-1)) at 0.01 <z <0.22 (look-back time of <2 Gyr). The merger fraction is approximately 1.5 per cent Gyr(-1) at all luminosities (assuming 50 per cent of pairs merge) and the volume merger rate is approximate to 3.5 x 10(-4) Mpc(-3) Gyr(-1). We examine how the merger rate varies by luminosity and morphology. Dry mergers (between red/spheroidal galaxies) are found to be uncommon and to decrease with decreasing luminosity. Fainter mergers are wet, between blue/discy galaxies. Damp mergers (one of each type) follow the average of dry and wetmergers. In the brighter luminosity bin (-23 <M-r <-20), the merger rate evolution is flat, irrespective of colour or morphology, out to z similar to 0.2. The makeup of the merging population does not appear to change over this redshift range. Galaxy growth by major mergers appears comparatively unimportant and dry mergers are unlikely to be significant in the buildup of the red sequence over the past 2 Gyr. We compare the colour, morphology, environmental density and degree of activity (BPT class, Baldwin, Phillips & Terlevich) of galaxies in pairs to those of more isolated objects in the same volume. Galaxies in close pairs tend to be both redder and slightly more spheroid dominated than the comparison sample. We suggest that this may be due to 'harassment' in multiple previous passes prior to the current close interaction. Galaxy pairs do not appear to prefer significantly denser environments. There is no evidence of an enhancement in the AGN fraction in pairs, compared to other galaxies in the same volume.Peer reviewe
Galaxy And Mass Assembly (GAMA) : the 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 μm to 1 mm
No full textWe use the Galaxy And Mass Assembly survey (GAMA) I data set combined with GALEX, Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) imaging to construct the low-redshift (z <0.1) galaxy luminosity functions in FUV, NUV, ugriz and YJHK bands from within a single well-constrained volume of 3.4 × 10 (Mpc h). The derived luminosity distributions are normalized to the SDSS data release 7 (DR7) main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 μm free from any wavelength-dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population, respectively. Using the Driver et al. prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 ± 0.3) × 10h W Mpc of which (1.2 ± 0.1) × 10h W Mpc is directly released into the inter-galactic medium and (0.6 ± 0.1) × 10h W Mpc is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid- and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post-dust attenuated energy output of the nearby Universe from 0.1μm to 0.6 mm. The largest uncertainty in this measurement lies in the mid- and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass and morphology.Peer reviewe
Regioselectivity of human UDP-glucuronosyltransferase isozymes in flavonoid biotransformation by metal complexation and tandem mass spectrometry
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