UCL University College London Eprints
UCL Eprints collects the work of UCL researchers and makes it freely available over the web, helping the worldwide scholarly community to discover UCL research. Institutional repositories like UCL Eprints complement the traditional academic publishing and scholarly communications processes. They raise the visibility of research and help to maximise its impact. UCL researchers are encouraged to deposit a copy of each journal article, conference paper, working paper, and any other research output, in the UCL Eprints at the earliest opportunity, ensuring that their research reaches as wide an audience as possible.
Stresses at the Cell Surface during Animal Cell Morphogenesis. - Clark, AG; Wartlick, O; Salbreux, G; Paluch, EK
Cell shape is determined by cellular mechanics. Cell deformations in animal cells, such as those required for cell migration, division or epithelial morphogenesis, are largely controlled by changes in mechanical stress and tension at the cell surface. The plasma membrane and the actomyosin cortex control surface mechanics and determine cell surface tension. Tension in the actomyosin cortex primarily arises from myosin-generated stresses and depends strongly on the ultrastructural architecture of the network. Plasma membrane tension is controlled mainly by the surface area of the membrane relative to cell volume and can be modulated by changing membrane composition, shape and the...
Cumulative impact of common genetic variants and other risk factors on colorectal cancer risk in 42 103 individuals - Dunlop, MG; Farrington, SM; Ballereau, S; Tenesa, A; Brewster, DH; Koessler, T; Pharoah, P; Schafmayer, C; Hampe, J; Völzke, H; Chang-Claude, J; Hoffmeister, M; Brenner, H; Von Holst, S; Picelli, S; Lindblom, A; Jenkins, MA; Hopper, JL; Casey, G; Duggan, D; Newcomb, PA; Abulí, A; Bessa, X; Ruiz-Ponte, C; Castellví-Bel, S; Niittymäki, I; Tuupanen, S; Karhu, A; Aaltonen, L; Zanke, B; Hudson, T; Gallinger, S; Barclay, E; Martin, L; Gorman, M; Carvajal-Carmona, L; Walther, A; Tomlinson, I; Kerr, D; Lubbe, S; Broderick, P; Chandler, I; Pittman, A; Penegar, S; Houlston, RS; Campbell, H
Objective: Colorectal cancer (CRC) has a substantial heritable component. Common genetic variation has been shown to contribute to CRC risk. A study was conducted in a large multi-population study to assess the feasibility of CRC risk prediction using common genetic variant data combined with other risk factors. A risk prediction model was built and applied to the Scottish population using available data. Design: Nine populations of European descent were studied to develop and validate CRC risk prediction models. Binary logistic regression was used to assess the combined effect of age, gender, family history (FH) and genotypes at 10 susceptibility loci...
8 guidelines for designing virtual citizen science projects - Jennett, C; Cox, AL
Is it unknown how to best design virtual citizen science projects so as to meet the needs of both scientists and volunteers. We present 8 design guidelines that we developed as a result of common problems we identified in our usability evaluations of 3 Citizen Cyberlab prototypes.
Simulations for a next-generation UHECR observatory - Oikonomou, F; Kotera, K; Abdalla, FB
We explore the potential of a future, ultra-high energy cosmic ray (UHECR) experiment, that is able to overcome the limitation of low statistics, to detect anisotropy in the arrival directions of UHECRs. We concentrate on the lower energy range of future instruments (E > 50 EeV), where, if the UHECR source number density is not too low, the sources should be numerous enough to imprint a clustering pattern in the sky, and thus possibly in the UHECR arrival directions. Under these limits, the anisotropy signal should be dominated by the clustering of astrophysical sources per-se in the large-scale structures, and...
Foreground Removal vs. Foreground Avoidance: Contamination of the EoR Window - Chapman, E; Zaroubi, S; Abdalla, F
The removal of the Galactic and extragalactic foregrounds remains a major challenge for those wishing to make a detection of the Epoch of Reionization 21-cm signal. Multiple methods of modelling these foregrounds with varying levels of assumption have been trialled and shown promising recoveries on simulated data. Recently however there has been increased discussion of using the expected shape of the foregrounds in Fourier space to define an EoR window free of foreground contamination. By carrying out analysis within this window only, one can avoid the foregrounds and any statistical bias they might introduce. In this paper we discuss the...
Lunar occultation of the diffuse radio sky: LOFAR measurements between 35 and 80 MHz - Vedantham, HK; Koopmans, LVE; Bruyn, AGD; Wijnholds, SJ; Brentjens, M; Abdalla, FB; Asad, KMB; Bernardi, G; Bus, S; Chapman, E; Ciardi, B; Daiboo, S; Fernandez, ER; Ghosh, A; Harker, G; Jelic, V; Jensen, H; Kazemi, S; Lambropoulos, P; Martinez-Rubi, O; Mellema, G; Mevius, M; Offringa, AR; Pandey, VN; Patil, AH; Thomas, RM; Veligatla, V; Yatawatta, S; Zaroubi, S; Anderson, J; Asgekar, A; Bell, ME; Bentum, MJ; Best, P; Bonafede, A; Breitling, F; Broderick, J; Brüggen, M; Butcher, HR; Corstanje, A; Gasperin, FD; Geus, ED; Deller, A; Duscha, S; Eislöffel, J; Engels, D; Falcke, H; Fallows, RA; Fender, R; Ferrari, C; Frieswijk, W; Garrett, MA; Grießmeier, J; Gunst, AW; Hassall, TE; Heald, G; Hoeft, M; Hörandel, J; Iacobelli, M; Juette, E; Kondratiev, VI; Kuniyoshi, M; Kuper, G; Mann, G; Markoff, S; McFadden, R; McKay-Bukowski, D; Mulcahy, DD; Munk, H; Nelles, A; Norden, MJ; Orru, E; Pandey-Pommier, M; Pizzo, R; Polatidis, AG; Reich, W; Renting, A; Röttgering, H; Schwarz, D; Shulevski, A; Smirnov, O; Stappers, BW; Steinmetz, M; Swinbank, J; Tagger, M; Tang, Y; Tasse, C; Veen, ST; Thoudam, S; Toribio, C; vocks, C; Wise, MW; Wucknitz, O; Zarka, P
We present radio observations of the Moon between $35$ and $80$ MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far beyond the primary beam (global signal) for the first time. In particular, we show that (i) the Moon appears as a negative-flux source at frequencies $35<\nu<80$ MHz since it is `colder' than the diffuse Galactic background it occults, (ii) using the (negative) flux of the lunar disc, we can reconstruct the spectrum of the diffuse Galactic emission with the lunar thermal emission as a reference, and (iii) that reflected RFI (radio-frequency interference) is concentrated at...
Combining Dark Energy Survey Science Verification Data with Near Infrared Data from the ESO VISTA Hemisphere Survey - Banerji, M; Jouvel, S; Lin, H; McMahon, RG; Lahav, O; Castander, FJ; Abdalla, FB; Bertin, E; Bosman, SE; Carnero, A; Kind, MC; Costa, LND; Gerdes, D; Gschwend, J; Lima, M; Maia, MAG; Merson, A; Miller, C; Ogando, R; Pellegrini, P; Reed, S; Saglia, R; Sanchez, C; Annis, SAJ; Bernstein, G; Bernstein, J; Bernstein, R; Capozzi, D; Childress, M; Cunha, CE; Davis, TM; DePoy, DL; Desai, S; Diehl, HT; Doel, P; Findlay, J; Finley, DA; Flaugher, B; Frieman, J; Gaztanaga, E; Glazebrook, K; Gonzalez-Fernandez, C; Gonzalez-Solares, E; Honscheid, K; Irwin, MJ; Jarvis, MJ; Kim, A; Koposov, S; Kuehn, K; Kupcu-Yoldas, A; Lagattuta, D; Lewis, JR; Lidman, C; Makler, M; Marriner, J; Marshall, JL; Miquel, R; Mohr, JJ; Neilsen, E; Peoples, J; Sako, M; Sanchez, E; Scarpine, V; Schindler, R; Schubnell, M; Sevilla, I; Sharp, R; Soares-Santos, M; Swanson, MEC; Tarle, G; Thaler, J; Tucker, D; Uddin, SA; Wechsler, R; Wester, W; Yuan, F; Zuntz, J
We present the combination of optical data from the Science Verification phase of the Dark Energy Survey (DES) with near infrared data from the ESO VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to extract fluxes and associated errors from the shallower VHS data. Joint 7-band (grizYJK) photometric catalogues are produced in a single 3 sq-deg DECam field centred at 02h26m-04d36m where the availability of ancillary multi-wavelength photometry and spectroscopy allows us to test the data quality. Dual photometry increases the number of DES galaxies with measured VHS fluxes by a factor of ~4.5 relative to...
Initial LOFAR observations of epoch of reionization windows II. Diffuse polarized emission in the ELAIS-N1 field - Jelic, V; de Bruyn, AG; Mevius, M; Abdalla, FB; Asad, KMB; Bernardi, G; Brentjens, MA; Bus, S; Chapman, E; Ciardi, B; Daiboo, S; Fernandez, ER; Ghosh, A; Harker, G; Jensen, H; Kazemi, S; Koopmans, LVE; Labropoulos, P; Martinez-Rubi, O; Mellema, G; Offringa, AR; Pandey, VN; Patil, AH; Thomas, RM; Vedantham, HK; Veligatla, V; Yatawatta, S; Zaroubi, S; Alexov, A; Anderson, J; Avruch, IM; Beck, R; Bell, ME; Bentum, MJ; Best, P; Bonafede, A; Bregman, J; Breitling, F; Broderick, J; Brouw, WN; Brueggen, M; Butcher, HR; Conway, JE; de Gasperin, F; de Geus, E; Deller, A; Dettmar, R-J; Duscha, S; Eisloeffel, J; Engels, D; Faleke, H; Fallows, RA; Fender, R; Ferrari, C; Frieswijk, W; Garrett, MA; Griessmeier, J; Gunst, AW; Hamaker, JP; Hassall, TE; Haverkorn, M; Heald, G; Hessels, JWT; Hoeft, M; Hoerandel, J; Horneffer, A; van der Horst, A; Iacobelli, M; Juette, E; Karastergiou, A; Kondratiev, VI; Kramer, M; Kuniyoshi, M; Kuper, G; van Leeuwen, J; Maat, P; Mann, G; McKay-Bakowski, D; MeKean, JP; Mank, H; Nelles, A; Morden, MJ; Paas, H; Pandey-Pornmier, M; Pietka, G; Pizzo, R; Polatidis, AG; Reich, W; Roettgering, H; Rowlinson, A; Scaife, AMM; Schwarz, D; Serylak, M; Smirnov, O; Steinmetz, M; Stewart, A; Tagger, M; Tang, Y; Tasse, C; ter Veen, S; Thoudam, S; Toribio, C; Vermeulen, R; Voeks, C; van Weeren, RJ; Wijers, RAMJ; Wijnholds, SJ; Wucknitz, O; Zarka, P
Photometric redshift analysis in the Dark Energy Survey Science Verification data - Sánchez, C; Kind, MC; Lin, H; Miquel, R; Abdalla, FB; Amara, A; Banerji, M; Bonnett, C; Brunner, R; Capozzi, D; Carnero, A; Castander, FJ; Costa, LAND; Cunha, C; Fausti, A; Gerdes, D; Greisel, N; Gschwend, J; Hartley, W; Jouvel, S; Lahav, O; Lima, M; Maia, MAG; Martí, P; Ogando, RLC; Ostrovski, F; Pellegrini, P; Rau, MM; Sadeh, I; Seitz, S; Sevilla-Noarbe, I; Sypniewski, A; Vicente, JD; Abbot, T; Allam, SS; Atlee, D; Bernstein, G; Bernstein, JP; Buckley-Geer, E; Burke, D; Childress, MJ; Davis, T; DePoy, DL; Dey, A; Desai, S; Diehl, HT; Doel, P; Estrada, J; Evrard, A; Fernández, E; Finley, D; Flaugher, B; Gaztanaga, E; Glazebrook, K; Honscheid, K; Kim, A; Kuehn, K; Kuropatkin, N; Lidman, C; Makler, M; Marshall, JL; Nichol, RC; Roodman, A; Sánchez, E; Santiago, BX; Sako, M; Scalzo, R; Smith, RC; Swanson, MEC; Tarle, G; Thomas, D; Tucker, DL; Uddin, SA; Valdés, F; Walker, A; Yuan, F; Zuntz, J
We present results from a study of the photometric redshift performance of the Dark Energy Survey (DES), using the early data from a Science Verification (SV) period of observations in late 2012 and early 2013 that provided science-quality images for almost 200 sq.~deg.~at the nominal depth of the survey. We assess the photometric redshift performance using about 15000 galaxies with spectroscopic redshifts available from other surveys. These galaxies are used, in different configurations, as a calibration sample, and photo-$z$'s are obtained and studied using most of the existing photo-$z$ codes. A weighting method in a multi-dimensional color-magnitude space is applied...