2,764 research outputs found

    To see or not to see a bow shock. Identifying bow shocks with Ha allsky surveys

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    OB-stars have the highest luminosities and strongest stellar winds of all stars, which enables them to interact strongly with their surrounding ISM, thus creating bow shocks. These offer us an ideal opportunity to learn more about the ISM. They were first detected and analysed around runaway OB-stars using the IRAS allsky survey by van Buren et al. (1995, AJ, 110, 2614). Using the geometry of such bow shocks information concerning the ISM density and its fluctuations can be gained from such infrared observations. As to help to improve the bow shock models, additional observations at other wavelengths, e.g. H, are most welcome. However due to their low velocity these bow shocks have a size of 1°, and could only be observed as a whole with great difficulties. In the light of the new H allsky surveys (SHASSA/VTSS) this is no problem any more. We developed different methods to detect bow shocks, e.g. the improved determination of their symmetry axis with radial distance profiles. Using two H-allsky surveys (SHASSA/VTSS), we searched for bow shocks and compared the different methods. From our sample we conclude, that the correlation between the direction of both proper motion and the symmetry axis determined with radial distance profile is the most promising detection method. We found eight bow shocks around HD 17505 , HD 24430 , HD 48099 , HD 57061 , HD 92206 , HD 135240 , HD 149757 , and HD 158186 from 37 candidates taken from van Buren et al. (1995, AJ, 110, 2614)

    Rapporteur’s report – innovative geotechnologies for energy transition

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    The 9th Society for Underwater Technology (SUT) International Conference on Offshore Site Investigation and Geotechnics (OSIG) closed with a Rapporteur’s report given by the author. This paper provides a record of that report, transcribed from a video recording. The presentation slides are shown as Figures.</p

    DEFRApH - Sample collection and handling procedures

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    All chemical and biogeochemical process in the sea are affected by the acidity of the water. Acidity is therefore fundamental property of seawater. The growing concern that the acidity of the oceans might be increasing has revealed weaknesses in our knowledge of this fundamental property and its variation in space and time. In 2008 the DEFRApH project (DEFRA contract ME4133) was initiated to provide this missing information in UK related waters. It required sampling for and analysis of the total inorganic carbon and total alkalinity content of samples. This reports documents the procedures sued for sampling. A companion document Hartman Dumousseaud and Roberts (NOC Internal Document No. 01) describes in detail the analytical procedures used and the calculation of the results

    Scientific Prospects of the 3D-NTT Instrument

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    Radio haloes in nearby galaxies modelled with 1d cosmic ray transport using SPINNAKER

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    We present radio continuum maps of 12 nearby (D ≤ 27 Mpc), edge-on (i ≥ 76?), latetypespiral galaxies mostly at 1.4 and 5 GHz, observed with the Australia Telescope CompactArray, Very LargeArray, Westerbork Synthesis Radio Telescope, Effelsberg 100-m, and Parkes64-m telescopes. All galaxies show clear evidence of radio haloes, including the first detectionin the Magellanic-type galaxy NGC 55. In 11 galaxies, we find a thin and a thick discthat can be better fitted by exponential rather than Gaussian functions. We fit our SPINNAKER(SPectral INdex Numerical Analysis of K(c)osmic-ray Electron Radio-emission) 1D cosmicray transport models to the vertical model profiles of the non-thermal intensity and to thenon-thermal radio spectral index in the halo. We simultaneously fit for the advection speed (ordiffusion coefficient) and magnetic field scale height. In the thick disc, the magnetic field scaleheights range from 2 to 8 kpc with an average across the sample of 3.0 ± 1.7 kpc; they showno correlation with either star formation rate (SFR), SFR surface density (Σ SFR), or rotationspeed (Vrot). The advection speeds range from 100 to 700 km s-1 and display correlations ofV α SFR0.36±0.06 and V α Σ0.39±0.09 SFR; they agree remarkably well with the escape velocities(0.5 ≤ V/Vesc ≤ 2), which can be explained by cosmic ray-driven winds. Radio haloes showthe presence of disc winds in galaxies with ΣSFR &gt; 10-3Mo˙yr-1 kpc-2 that extend overseveral kpc and are driven by processes related to the distributed star formation in the disc.</p

    Sunitinib treatment exacerbates intratumoral heterogeneity in metastatic renal cancer

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    This work was supported by the Chief Scientist Office, Scotland (ETM37; to G.D. Stewart, A.C.P. Riddick, M. Aitchison, and D.J. Harrison), Cancer Research UK (Experimental Cancer Medicine Centre; to T. Powles, London and D.J. Harrison, Edinburgh), Medical Research Council (to A. Laird and D.J. Harrison), Royal College of Surgeons of Edinburgh (to A. Laird), Melville Trust (to A. Laird), Medical Research Council (MC_UU_12018/25; to I.M. Overton), Royal Society of Edinburgh Scottish Government Fellowship cofunded by Marie Curie Actions (to I.M. Overton), Renal Cancer Research Fund (to G.D. Stewart), Kidney Cancer Scotland (to G.D. Stewart) and an educational grant from Pfizer (to T. Powles).Purpose: The aim of this study was to investigate the effect of VEGF targeted therapy (sunitinib) on molecular intratumoral heterogeneity (ITH) in metastatic clear cell renal cancer (mccRCC). Experimental design: Multiple tumor samples (n=187 samples) were taken from the primary renal tumors of mccRCC patients who were sunitinib treated (n=23, SuMR clinical trial) or untreated (n=23, SCOTRRCC study). ITH of pathological grade, DNA (aCGH), mRNA (Illumina Beadarray) and candidate proteins (reverse phase protein array) were evaluated using unsupervised and supervised analyses (driver mutations, hypoxia and stromal related genes). ITH was analysed using intratumoral protein variance distributions and distribution of individual patient aCGH and gene expression clustering. Results: Tumor grade heterogeneity was greater in treated compared to untreated tumors (P=0.002). In unsupervised analysis, sunitinib therapy was not associated with increased ITH in DNA or mRNA. However, there was an increase in ITH for the driver mutation gene signature (DNA and mRNA) as well as increasing variability of protein expression with treatment (p<0.05). Despite this variability, significant chromosomal and transcript changes to key targets of sunitinib, such as VHL, PBRM1 and CAIX, occurred in the treated samples. Conclusions: These findings suggest that sunitinib treatment has significant effects on the expression and ITH of key tumor and treatment specific genes/proteins in mccRCC. The results, based on primary tumor analysis, do not support the hypothesis that resistant clones are selected and predominate following targeted therapy.Peer reviewe

    Reply to the discussion by McCarron on “Modelling spatial variability in as-laid embedment for high pressure and high temperature (HPHT) pipeline design”

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    N/AThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror

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    We experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ~12 ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3 ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5 km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ~15 nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality

    An introduction to management science: quantitative approaches to decision making

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    Retaining the accessible application-driven approach for which An Introduction to Management Science is highly regarded, adapting author Mik Wisniewski has carefully reworked the existing US textbook to benefit students across the UK, Europe, Middle East and Africa. Packed with diverse realistic examples from Scotland to Saudi Arabia, the landmark text from the ASW team is now available in a truly internationalised version for students studying Management Science and Operations Research at postgraduate and undergraduate level
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