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344 results on '"Pettitt, A R"'

3. Whole-genome sequencing of chronic lymphocytic leukemia identifies subgroups with distinct biological and clinical features

Author

Robbe, Pauline, Ridout, Kate E., Vavoulis, Dimitrios V., Dréau, Helene, Kinnersley, Ben, Denny, Nicholas, Chubb, Daniel, Appleby, Niamh, Cutts, Anthony, Cornish, Alex J., Lopez-Pascua, Laura, Clifford, Ruth, Burns, Adam, Stamatopoulos, Basile, Cabes, Maite, Alsolami, Reem, Antoniou, Pavlos, Oates, Melanie, Cavalieri, Doriane, Gibson, Jane, Prabhu, Anika V., Schwessinger, Ron, Jennings, Daisy, James, Terena, Maheswari, Uma, Duran-Ferrer, Martí, Carninci, Piero, Knight, Samantha J. L., Månsson, Robert, Hughes, Jim, Davies, James, Ross, Mark, Bentley, David, Strefford, Jonathan C., Devereux, Stephen, Pettitt, Andrew R., Hillmen, Peter, Caulfield, Mark J., Houlston, Richard S., Martín-Subero, José I., and Schuh, Anna

Published
2022
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6. Self-consistent modelling of the Milky Way structure using live potentials.

Author

Durán-Camacho, Eva, Duarte-Cabral, Ana, Pettitt, Alex R, Treß, Robin G, Clark, Paul C, Klessen, Ralf S, Bogue, Kamran R J, Smith, Rowan J, and Sormani, Mattia C

Subjects
MILKY Way, INTERSTELLAR medium, TERMINAL velocity, STAR formation, STREAMING video & television
Abstract

To advance our understanding of the evolution of the interstellar medium (ISM) of our Galaxy, numerical models of Milky Way (MW) type galaxies are widely used. However, most models only vaguely resemble the MW (e.g. in total mass), and often use imposed analytic potentials (which cannot evolve dynamically). This poses a problem in asserting their applicability for the interpretation of observations of our own Galaxy. The goal of this work is to identify a numerical model that is not only an MW-type galaxy, but one that can mimic some of the main observed structures of our Galaxy, using dynamically evolving potentials, so that it can be used as a base model to study the ISM cycle in a galaxy like our own. This paper introduces a suite of 15 MW-type galaxy models developed using the arepo numerical code, that are compared to Galactic observations of |$^{12}$| CO and H  i emission via longitude–velocity plots, from where we extract and compare the skeletons of major galactic features and the terminal gas velocities. We found that our best-fitting model to the overall structure, also reproduces some of the more specific observed features of the MW, including a bar with a pattern speed of |$30.0 \pm 0.2$| km s |$^{-1}$|  kpc |$^{-1}$|⁠ , and a bar half-length of |$3.2 \pm 0.8$|  kpc. Our model shows large streaming motions around spiral arms, and strong radial motions well beyond the inner bar. This model highlights the complex motions of a dynamic MW-type galaxy and has the potential to offer valuable insight into how our Galaxy regulates the ISM and star formation. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Clinical significance of DNA methylation in chronic lymphocytic leukemia patients: results from 3 UK clinical trials

Author

Wojdacz, Tomasz K., Amarasinghe, Harindra E., Kadalayil, Latha, Beattie, Alice, Forster, Jade, Blakemore, Stuart J., Parker, Helen, Bryant, Dean, Larrayoz, Marta, Clifford, Ruth, Robbe, Pauline, Davis, Zadie A., Else, Monica, Howard, Dena R., Stamatopoulos, Basile, Steele, Andrew J., Rosenquist, Richard, Collins, Andrew, Pettitt, Andrew R., Hillmen, Peter, Plass, Christoph, Schuh, Anna, Catovsky, Daniel, Oscier, David G., Rose-Zerilli, Matthew J.J., Oakes, Christopher C., and Strefford, Jonathan C.

Published
2019
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12. JASMINE: Near-infrared astrometry and time-series photometry science.

Author

Kawata, Daisuke, Kawahara, Hajime, Gouda, Naoteru, Secrest, Nathan J, Kano, Ryouhei, Kataza, Hirokazu, Isobe, Naoki, Ohsawa, Ryou, Usui, Fumihiko, Yamada, Yoshiyuki, Graham, Alister W, Pettitt, Alex R, Asada, Hideki, Baba, Junichi, Bekki, Kenji, Dorland, Bryan N, Fujii, Michiko, Fukui, Akihiko, Hattori, Kohei, and Hirano, Teruyuki

Subjects
GALACTIC center, JASMINE, PHOTOMETRY, ASTROMETRY, VARIABLE stars, MILKY Way
Abstract

The Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is Galactic archaeology with a Galactic Center survey, which aims to reveal the Milky Way's central core structure and formation history from Gaia-level (∼25 |${\mu} $| as) astrometry in the near-infrared (NIR) H w band (1.0–1.6  |${\mu} $| m). The other is an exoplanet survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic Center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information on the stars in the Galactic Center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic Center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars, and microlensing studies, including discovery of (intermediate-mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions. [ABSTRACT FROM AUTHOR]

Published
2024
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13. The impact of bar origin and morphology on stellar migration.

Author

Iles, Elizabeth J, Pettitt, Alex R, Okamoto, Takashi, and Kawata, Daisuke

Subjects
*STELLAR evolution, *STAR formation, *STELLAR populations, *MORPHOLOGY, *STELLAR orbits
Abstract

Different mechanisms driving bar structure formation indicate that bar origins should be distinguishable in the stellar populations of galaxies. To study how these origins affect different bar morphologies and impact stellar orbits and migration, we analyse three simulated discs which are representative of bar formation under isolated evolution motivated by disc instability, and interaction-driven tidal development. The first isolated disc and the tidally driven disc produce similar bar structure, while the second isolated disc, generated by the tidal initial condition without the companion, is visibly dissimilar. Changes to radial and vertical positions, angular momentum in the disc-plane, orbital eccentricity, and the subsequent disc metallicities are assessed, as is the dependence on stellar age and formation radii. Bar origin is distinguishable, with the tidal disc displaying larger migration overall, higher metallicity difference between the inner and outer disc, and a population of inner disc stars displaced to large radii and below the disc-plane. The effect of closest approach on populations of stars formed before, after, and during this period is evident. However, bar morphology is also found to be a significant factor in the evolution of disc stellar properties, with similar bars producing similar traits in migration tendency with radius, particularly in vertical stellar motion and in the evolution of central metallicity features. [ABSTRACT FROM AUTHOR]

Published
2024
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16. Chlorambucil plus ofatumumab versus chlorambucil alone in previously untreated patients with chronic lymphocytic leukaemia (COMPLEMENT 1): a randomised, multicentre, open-label phase 3 trial

Author

Hillmen, Peter, Robak, Tadeusz, Janssens, Ann, Babu, K Govind, Kloczko, Janusz, Grosicki, Sebastian, Doubek, Michael, Panagiotidis, Panagiotis, Kimby, Eva, Schuh, Anna, Pettitt, Andrew R, Boyd, Thomas, Montillo, Marco, Gupta, Ira V, Wright, Oliver, Dixon, Iestyn, Carey, Jodi L, Chang, Chai-Ni, Lisby, Steen, McKeown, Astrid, and Offner, Fritz

Published
2015
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18. Star cluster formation and feedback in different environments of a Milky Way-like galaxy.

Author

Ali, Ahmad A, Dobbs, Clare L, Bending, Thomas J R, Buckner, Anne S M, and Pettitt, Alex R

Subjects
STAR formation, INTERSTELLAR medium, STAR clusters, DENSITY of stars, GLOBULAR clusters, GALAXY clusters
Abstract

It remains unclear how galactic environment affects star formation and stellar cluster properties. This is difficult to address in Milky Way-mass galaxy simulations because of limited resolution and less accurate feedback compared to cloud-scale models. We carry out zoom-in simulations to re-simulate 100– |$300 \,\rm {pc}$| regions of a Milky Way-like galaxy using smoothed particle hydrodynamics, including finer resolution (⁠|$0.4 \,\rm {M_{\odot }{}}$| per particle), cluster-sink particles, ray-traced photoionization from O stars, H2/CO chemistry, and interstellar medium heating/cooling. We select ∼ |$10^{6} \,\rm {M_{\odot }{}}$| cloud complexes from a galactic bar, inner spiral arm, outer arm, and inter-arm region (in order of galactocentric radius), retaining the original galactic potentials. The surface densities of star formation rate and neutral gas follow |$\Sigma _\mathrm{SFR}\propto \Sigma _\mathrm{gas}^{1.3}$|⁠ , with the bar lying higher up the relation than the other regions. However, the inter-arm region forms stars two to three times less efficiently than the arm models at the same Σgas. The bar produces the most massive cluster, the inner arm the second, and the inter-arm the third. Almost all clusters in the bar and inner arm are small (radii <5 pc), while 30–50 per cent of clusters in the outer arm and inter-arm have larger radii more like associations. Bar and inner arm clusters rotate at least twice as fast, on average, than clusters in the outer arm and inter-arm regions. The degree of spatial clustering also decreases from bar to inter-arm. Our results indicate that young massive clusters, potentially progenitors of globular clusters, may preferentially form near the bar/inner arm compared to outer arm/inter-arm regions. [ABSTRACT FROM AUTHOR]

Published
2023
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19. Massive core/star formation triggered by cloud–cloud collision – II. High-speed collisions of magnetized clouds.

Author

Sakre, Nirmit, Habe, Asao, Pettitt, Alex R, Okamoto, Takashi, Enokiya, Rei, Fukui, Yasuo, and Hosokawa, Takashi

Subjects
STAR formation, MAGNETIC field effects, SUPERGIANT stars, MAGNETIC fields, RELATIVE velocity, PLANETESIMALS
Abstract

We present a study of the effects of magnetic fields on the formation of massive, self-gravitationally bound cores (MBCs) in high-speed cloud–cloud collisions (CCCs). Extending our previous work, we perform magnetohydrodynamic simulations of the high-speed (20–40 km s−1) collisions between two magnetized (initial 4  |$\mu\!$| G), turbulent clouds of different sizes in the range of 7–20 pc. We show that a magnetic field hinders the growth of cores, particularly in the case of short-duration collisions where cores are not seen to reach a highly bound state. In such cases, a shocked region created by the collision rapidly expands into the ambient medium owing to the enhanced magnetic pressure, resulting in the destruction of the highly unbound cores and suppression of gas accretion. This negative effect on the formation of MBCs has not been reported in previous hydrodynamic simulations of CCCs. Together with our previous work, we conclude that magnetic fields provide two competing effects on the MBC formation in CCCs; while they promote the mass accumulation onto cores during a collision, they operate to destroy cores or hinder the core growth after the collision. The duration of such collisions determines which effect prevails, resulting in a maximum collision speed for the MBC formation within given colliding clouds. Our results agree with the observed trend among CCC samples in the column density range probed in the simulations presented here; CCCs with higher relative velocities require higher column densities for the formation of massive stars. [ABSTRACT FROM AUTHOR]

Published
2023
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22. Genome-wide association analysis of chronic lymphocytic leukaemia, Hodgkin lymphoma and multiple myeloma identifies pleiotropic risk loci

Author

Law, Philip J., Sud, Amit, Mitchell, Jonathan S., Henrion, Marc, Orlando, Giulia, Lenive, Oleg, Broderick, Peter, Speedy, Helen E., Johnson, David C., Kaiser, Martin, Weinhold, Niels, Cooke, Rosie, Sunter, Nicola J., Jackson, Graham H., Summerfield, Geoffrey, Harris, Robert J., Pettitt, Andrew R., Allsup, David J., Carmichael, Jonathan, Bailey, James R., Pratt, Guy, Rahman, Thahira, Pepper, Chris, Fegan, Chris, von Strandmann, Elke Pogge, Engert, Andreas, Försti, Asta, Chen, Bowang, Filho, Miguel Inacio da Silva, Thomsen, Hauke, Hoffmann, Per, Noethen, Markus M., Eisele, Lewin, Jöckel, Karl-Heinz, Allan, James M., Swerdlow, Anthony J., Goldschmidt, Hartmut, Catovsky, Daniel, Morgan, Gareth J., Hemminki, Kari, and Houlston, Richard S.

Published
2017
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23. EBV-associated post-transplant lymphoproliferative disorder following in vivo T-cell-depleted allogeneic transplantation: clinical features, viral load correlates and prognostic factors in the rituximab era

Author

Fox, C P, Burns, D, Parker, A N, Peggs, K S, Harvey, C M, Natarajan, S, Marks, D I, Jackson, B, Chakupurakal, G, Dennis, M, Lim, Z, Cook, G, Carpenter, B, Pettitt, A R, Mathew, S, Connelly-Smith, L, Yin, J A L, Viskaduraki, M, Chakraverty, R, Orchard, K, Shaw, B E, Byrne, J L, Brookes, C, Craddock, C F, and Chaganti, S

Published
2014
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24. Supplement to: Idelalisib and rituximab in relapsed chronic lymphocytic leukemia.

Author

Furman, Richard R., Sharman, Jeff P., Coutre, Steven E., Cheson, Bruce D., Pagel, John M., Hillmen, Peter, Barrientos, Jacqueline C., Zelenetz, Andrew D., Kipps, Thomas J., Flinn, Ian, Ghia, Paolo, Eradat, Herbert, Ervin, Thomas, Lamanna, Nicole, Coiffier, Bertrand, Pettitt, Andrew R., Ma, Shuo, Stilgenbauer, Stephan, Cramer, Paula, Aiello, Maria, Johnson, Dave M., Miller, Langdon L., Li, Daniel, Jahn, Thomas M., Dansey, Roger D., Hallek, Michael, and OʼBrien, Susan M.

Published
2014

25. Common variation at 12q24.13 (OAS3) influences chronic lymphocytic leukemia risk

Author

Sava, G P, Speedy, H E, Di Bernardo, M C, Dyer, M JS, Holroyd, A, Sunter, N J, Marr, H, Mansouri, L, Deaglio, S, Karabon, L, Frydecka, I, Jamroziak, K, Woszczyk, D, Juliusson, G, Smedby, K E, Jayne, S, Majid, A, Wang, Y, Dearden, C, Hall, A G, Mainou-Fowler, T, Jackson, G H, Summerfield, G, Harris, R J, Pettitt, A R, Allsup, D J, Bailey, J R, Pratt, G, Pepper, C, Fegan, C, Rosenquist, R, Catovsky, D, Allan, J M, and Houlston, R S

Published
2015
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32. Idelalisib and Rituximab in Relapsed Chronic Lymphocytic Leukemia

Author

Furman, Richard R., Sharman, Jeff P., Coutre, Steven E., Cheson, Bruce D., Pagel, John M., Hillmen, Peter, Barrientos, Jacqueline C., Zelenetz, Andrew D., Kipps, Thomas J., Flinn, Ian, Ghia, Paolo, Eradat, Herbert, Ervin, Thomas, Lamanna, Nicole, Coiffier, Bertrand, Pettitt, Andrew R., Ma, Shuo, Stilgenbauer, Stephan, Cramer, Paula, Aiello, Maria, Johnson, Dave M., Miller, Langdon L., Li, Daniel, Jahn, Thomas M., Dansey, Roger D., Hallek, Michael, and OʼBrien, Susan M.

Published
2014
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39. The changing GMC population in galaxy interactions

Author

Pettitt, Alex R., Egusa, Fumi, Dobbs, Clare L., Tasker, Elizabeth J., Fujimoto, Yusuke, and Habe, Asao

Subjects
ISM: structure, Population, FOS: Physical sciences, Context (language use), Cloud computing, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, methods: numerical, 0103 physical sciences, education, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, Spiral galaxy, 010308 nuclear & particles physics, Star formation, business.industry, Molecular cloud, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Interstellar medium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: spiral, business
Abstract

With the advent of modern observational efforts providing extensive giant molecular cloud catalogues, understanding the evolution of such clouds in a galactic context is of prime importance. While numerous previous numerical and theoretical works have focused on the cloud properties in isolated discs, few have looked into the cloud population in an interacting disc system. We present results of the first study investigating the evolution of the cloud population in galaxy experiencing an M51-like tidal fly-by using numerical simulations including star formation, interstellar medium cooling and stellar feedback. We see the cloud population shift to large unbound clouds in the wake of the companion passage, with the largest clouds appearing as fleeting short-lived agglomerations of smaller clouds within the tidal spiral arms, brought together by large scale streaming motions. These are then sheared apart as they leave the protection of the spiral arms. Clouds appear to lead diverse lives, even within similar environments, with some being born from gas shocked by filaments streaming into the spiral arms, and others from effectively isolated smaller colliding pairs. Overall this cloud population produces a shallower mass function than the disc in isolation, especially in the arms compared to the inter-arm regions. Direct comparisons to M51 observations show similarities between cloud populations, though models tailored to the mass and orbital models of M51 appear necessary to precisely reproduce the cloud population., 21 pages, 25 figures, accepted for publication in MNRAS July 25 2018

Published
2018

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