TY - JOUR A1 - Beaulieu, Jean-Philippe A1 - Bennett, David P. A1 - Fouqué, Pascal A1 - Williams, Andrew A1 - Dominik, Martin A1 - Jorgensen, Uffe Grae A1 - Kubas, Daniel A1 - Cassan, Arnaud A1 - Coutures, Christian A1 - Greenhill, John A1 - Hill, Kym A1 - Menzies, John A1 - Sackett, Penny D. A1 - Albrow, Michael D. A1 - Brillant, Stephane A1 - Caldwell, John A. R. A1 - Calitz, Johannes Jacobus A1 - Cook, Kem H. A1 - Corrales Cosmeli, Esperanza de Santa Cecilia A1 - Desort, Morgan A1 - Dieters, Stefan A1 - Dominis, Dijana A1 - Donatowicz, Jadzia A1 - Hoffman, Martie A1 - Kane, Stephen R. A1 - Marquette, Jean-Baptiste A1 - Martin, Ralph A1 - Meintjes, Pieter A1 - Pollard, Karen R. A1 - Sahu, Kailash C. A1 - Vinter, Christian A1 - Wambsganss, Joachim A1 - Woller, Kristian A1 - Horne, Keith A1 - Steele, Iain A1 - Bramich, Daniel M. A1 - Burgdorf, Martin A1 - Snodgrass, Colin A1 - Bode, Mike A1 - Udalski, Andr T1 - Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing N2 - In the favoured core-accretion model of formation of planetary systems, solid planetesimals accumulate to build up planetary cores, which then accrete nebular gas if they are sufficiently massive. Around M-dwarf stars ( the most common stars in our Galaxy), this model favours the formation of Earth-mass (M+) to Neptune-mass planets with orbital radii of 1 to 10 astronomical units (AU), which is consistent with the small number of gas giant planets known to orbit M-dwarf host stars(1-4). More than 170 extrasolar planets have been discovered with a wide range of masses and orbital periods, but planets of Neptune's mass or less have not hitherto been detected at separations of more than 0.15 AU from normal stars. Here we report the discovery of a 5.5(-2.7)(+5.5)M(+) planetary companion at a separation of 2.6(- 0.6)(+1.5) AU from a 0.22(-0.11)(+0.21)M(.) M-dwarf star, where M-. refers to a solar mass. (We propose to name it OGLE- 2005-BLG-390Lb, indicating a planetary mass companion to the lens star of the microlensing event.) The mass is lower than that of GJ876d (ref. 5), although the error bars overlap. Our detection suggests that such cool, sub-Neptune-mass planets may be more common than gas giant planets, as predicted by the core accretion theory. Y1 - 2006 UR - http://www.nature.com/nature/ U6 - https://doi.org/10.1038/Nature04441 SN - 0028-0836 ER - TY - JOUR A1 - Chipman, Ariel D. A1 - Ferrier, David E. K. A1 - Brena, Carlo A1 - Qu, Jiaxin A1 - Hughes, Daniel S. T. A1 - Schroeder, Reinhard A1 - Torres-Oliva, Montserrat A1 - Znassi, Nadia A1 - Jiang, Huaiyang A1 - Almeida, Francisca C. A1 - Alonso, Claudio R. A1 - Apostolou, Zivkos A1 - Aqrawi, Peshtewani A1 - Arthur, Wallace A1 - Barna, Jennifer C. J. A1 - Blankenburg, Kerstin P. A1 - Brites, Daniela A1 - Capella-Gutierrez, Salvador A1 - Coyle, Marcus A1 - Dearden, Peter K. A1 - Du Pasquier, Louis A1 - Duncan, Elizabeth J. A1 - Ebert, Dieter A1 - Eibner, Cornelius A1 - Erikson, Galina A1 - Evans, Peter D. A1 - Extavour, Cassandra G. A1 - Francisco, Liezl A1 - Gabaldon, Toni A1 - Gillis, William J. A1 - Goodwin-Horn, Elizabeth A. A1 - Green, Jack E. A1 - Griffiths-Jones, Sam A1 - Grimmelikhuijzen, Cornelis J. P. A1 - Gubbala, Sai A1 - Guigo, Roderic A1 - Han, Yi A1 - Hauser, Frank A1 - Havlak, Paul A1 - Hayden, Luke A1 - Helbing, Sophie A1 - Holder, Michael A1 - Hui, Jerome H. L. A1 - Hunn, Julia P. A1 - Hunnekuhl, Vera S. A1 - Jackson, LaRonda A1 - Javaid, Mehwish A1 - Jhangiani, Shalini N. A1 - Jiggins, Francis M. A1 - Jones, Tamsin E. A1 - Kaiser, Tobias S. A1 - Kalra, Divya A1 - Kenny, Nathan J. A1 - Korchina, Viktoriya A1 - Kovar, Christie L. A1 - Kraus, F. Bernhard A1 - Lapraz, Francois A1 - Lee, Sandra L. A1 - Lv, Jie A1 - Mandapat, Christigale A1 - Manning, Gerard A1 - Mariotti, Marco A1 - Mata, Robert A1 - Mathew, Tittu A1 - Neumann, Tobias A1 - Newsham, Irene A1 - Ngo, Dinh N. A1 - Ninova, Maria A1 - Okwuonu, Geoffrey A1 - Ongeri, Fiona A1 - Palmer, William J. A1 - Patil, Shobha A1 - Patraquim, Pedro A1 - Pham, Christopher A1 - Pu, Ling-Ling A1 - Putman, Nicholas H. A1 - Rabouille, Catherine A1 - Ramos, Olivia Mendivil A1 - Rhodes, Adelaide C. A1 - Robertson, Helen E. A1 - Robertson, Hugh M. A1 - Ronshaugen, Matthew A1 - Rozas, Julio A1 - Saada, Nehad A1 - Sanchez-Gracia, Alejandro A1 - Scherer, Steven E. A1 - Schurko, Andrew M. A1 - Siggens, Kenneth W. A1 - Simmons, DeNard A1 - Stief, Anna A1 - Stolle, Eckart A1 - Telford, Maximilian J. A1 - Tessmar-Raible, Kristin A1 - Thornton, Rebecca A1 - van der Zee, Maurijn A1 - von Haeseler, Arndt A1 - Williams, James M. A1 - Willis, Judith H. A1 - Wu, Yuanqing A1 - Zou, Xiaoyan A1 - Lawson, Daniel A1 - Muzny, Donna M. A1 - Worley, Kim C. A1 - Gibbs, Richard A. A1 - Akam, Michael A1 - Richards, Stephen T1 - The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima JF - PLoS biology N2 - Myriapods (e. g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history. Y1 - 2014 U6 - https://doi.org/10.1371/journal.pbio.1002005 SN - 1545-7885 VL - 12 IS - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Chladkova, Katerina A1 - Hamann, Silke A1 - Williams, Daniel A1 - Hellmuth, Sam T1 - F2 slope as a Perceptual Cue for the Front-Back Contrast in Standard Southern British English JF - Language and speech N2 - Acoustic studies of several languages indicate that second-formant (F2) slopes in high vowels have opposing directions (independent of consonantal context): front [i.]-like vowels are produced with a rising F2 slope, whereas back [u.]-like vowels are produced with a falling F2 slope. The present study first reports acoustic measurements that confirm this pattern for the English variety of Standard Southern British English (SSBE), where /u./ has shifted from the back to the front area of the vowel space and is now realized with higher midpoint F2 values than several decades ago. Subsequently, we test whether the direction of F2 slope also serves as a reliable cue to the /i.// u./ contrast in perception. The findings show that F2 slope direction is used as a cue (additional to midpoint formant values) to distinguish /i./ from /u./by both young and older Standard Southern British English listeners: an otherwise ambiguous token is identified as /i./if it has a rising F2 slope and as /u./if it has a falling F2 slope. Furthermore, our results indicate that listeners generalize their reliance on F2 slope to other contrasts, namely /epsilon/-/./and /ae/-/./, even though F2 slope is not employed to differentiate these vowels in production. This suggests that in Standard Southern British English, a rising F2 seems to be perceptually associated with an abstract feature such as [+ front], whereas a falling F2 with an abstract feature such as [-front]. KW - perceptual cues KW - front-back contrast KW - /u./-fronting KW - Standard Southern British English KW - vowel perception KW - phonological feature Y1 - 2017 U6 - https://doi.org/10.1177/0023830916650991 SN - 0023-8309 SN - 1756-6053 VL - 60 SP - 377 EP - 398 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Palkopoulou, Eleftheria A1 - Lipson, Mark A1 - Mallick, Swapan A1 - Nielsen, Svend A1 - Rohland, Nadin A1 - Baleka, Sina Isabelle A1 - Karpinski, Emil A1 - Ivancevici, Atma M. A1 - Thu-Hien To, A1 - Kortschak, Daniel A1 - Raison, Joy M. A1 - Qu, Zhipeng A1 - Chin, Tat-Jun A1 - Alt, Kurt W. A1 - Claesson, Stefan A1 - Dalen, Love A1 - MacPhee, Ross D. E. A1 - Meller, Harald A1 - Rocar, Alfred L. A1 - Ryder, Oliver A. A1 - Heiman, David A1 - Young, Sarah A1 - Breen, Matthew A1 - Williams, Christina A1 - Aken, Bronwen L. A1 - Ruffier, Magali A1 - Karlsson, Elinor A1 - Johnson, Jeremy A1 - Di Palma, Federica A1 - Alfoldi, Jessica A1 - Adelsoni, David L. A1 - Mailund, Thomas A1 - Munch, Kasper A1 - Lindblad-Toh, Kerstin A1 - Hofreiter, Michael A1 - Poinar, Hendrik A1 - Reich, David T1 - A comprehensive genomic history of extinct and living elephants JF - Proceedings of the National Academy of Sciences of the United States of America KW - paleogenomics KW - elephantid evolution KW - mammoth KW - admixture KW - species divergence Y1 - 2018 U6 - https://doi.org/10.1073/pnas.1720554115 SN - 0027-8424 VL - 115 IS - 11 SP - E2566 EP - E2574 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Kubas, Daniel A1 - Cassan, A. A1 - Beaulieu, Jean-Philippe A1 - Coutures, C. A1 - Dominik, M. A1 - Albrow, Michael D. A1 - Brillant, Stephane A1 - Caldwell, John A. R. A1 - Dominis, Dijana A1 - Donatowicz, J. A1 - Fendt, Christian A1 - Fouque, P. A1 - Jorgensen, Uffe Grae A1 - Greenhill, John A1 - Hill, K. A1 - Heinmüller, Janine A1 - Horne, Keith A1 - Kane, Stephen R. A1 - Marquette, Jean-Baptiste A1 - Martin, Ralph A1 - Menzies, J. W. A1 - Pollard, K. R. A1 - Sahu, K. C. A1 - Vinter, C. A1 - Wambsganss, Joachim A1 - Watson, R. A1 - Williams, A. A1 - Thurl, C. T1 - Full characterization of binary-lens event OGLE-2002-BLG-069 from PLANET observations N2 - We analyze the photometric data obtained by PLANET and OGLE on the caustic-crossing binary-lens microlensing event OGLE-2002-BLG-069. Thanks to the excellent photometric and spectroscopic coverage of the event, we are able to constrain the lens model up to the known ambiguity between close and wide binary lenses. The detection of annual parallax in combination with measurements of extended-source effects allows us to determine the mass, distance and velocity of the lens components for the competing models. While the model involving a close binary lens leads to a Bulge- Disc lens scenario with a lens mass of M = (0.51 ± 0.15) M-&ODOT; and distance of D-L = (2.9 ± 0.4) kpc, the wide binary lens solution requires a rather implausible binary black-hole lens ( M &GSIM; 126 M-&ODOT;). Furthermore we compare current state-of-the-art numerical and empirical models for the surface brightness profile of the source, a G5III Bulge giant. We find that a linear limb-darkening model for the atmosphere of the source star is consistent with the data whereas a PHOENIX atmosphere model assuming LTE and with no free parameter does not match our observations Y1 - 2005 SN - 0004-6361 ER - TY - JOUR A1 - Cassan, A. A1 - Beaulieu, Jean-Philippe A1 - Brillant, Stephane A1 - Coutures, C. A1 - Dominik, M. A1 - Donatowicz, J. A1 - Jorgensen, Uffe Grae A1 - Kubas, Daniel A1 - Albrow, Michael D. A1 - Caldwell, John A. R. A1 - Fouque, P. A1 - Greenhill, John A1 - Hill, K. A1 - Horne, Keith A1 - Kane, Stephen R. A1 - Martin, Ralph A1 - Menzies, J. W. A1 - Pollard, K. R. A1 - Sahu, K. C. A1 - Vinter, C. A1 - Wambsganss, Joachim A1 - Watson, R. A1 - Williams, A. A1 - Fendt, Christian A1 - Hauschildt, P. A1 - Heinmueller, Janine A1 - Marquette, Jean-Baptiste A1 - Thurl, C. T1 - Probing the atmosphere of the bulge G5III star OGLE-2002-BUL-069 by analysis of microlensed H alpha line N2 - We discuss high-resolution, time-resolved spectra of the caustic exit of the binary microlensing event OGLE 2002-BLG-069 obtained with UVES on the VLT. The source star is a G5III giant in the Galactic Bulge. During such events, the source star is highly magnified, and a strong differential magnification around the caustic resolves its surface. Using an appropriate model stellar atmosphere generated by the PHOENIX v2.6 code we obtain a model light curve for the caustic exit and compare it with a dense set of photometric observations obtained by the PLANET microlensing follow up network. We further compare predicted variations in the Halpha equivalent width with those measured from our spectra. While the model and observations agree in the gross features, there are discrepancies suggesting shortcomings in the model, particularly for the Halpha line core, where we have detected amplified emission from the stellar chromosphere after the source star's trailing limb exited the caustic. This achievement became possible by the provision of the very efficient OGLE-III Early Warning System, a network of small telescopes capable of nearly-continuous round-the-clock photometric monitoring, on-line data reduction, daily near-real-time modelling in order to predict caustic crossing parameters, and a fast and efficient response of a 8 m class telescope to a "Target-of-Opportunity" observation request Y1 - 2004 ER - TY - JOUR A1 - Jiang, G. F. A1 - DePoy, D. L. A1 - Gal-Yam, A. A1 - Gaudi, B. S. A1 - Gould, A. A1 - Han, C. A1 - Lipkin, Y. A1 - Maoz, D. A1 - Ofek, E. O. A1 - Park, B. G. A1 - Pogge, R. W. A1 - Udalski, A. A1 - Kubiak, Marcin A1 - Szymanski, M. K. A1 - Szewczyk, O. A1 - Zerbrun, K. A1 - Wyrzykowski, L. A1 - Soszynski, I. A1 - Pietrzynski, G. A1 - Albrow, Michael D. A1 - Beaulieu, Jean-Philippe A1 - Caldwell, John A. R. A1 - Cassan, A. A1 - Coutures, C. A1 - Dominik, M. A1 - Donatowicz, J. A1 - Fouque, P. A1 - Greenhill, John A1 - Hill, K. A1 - Horne, Keith A1 - Jorgensen, S. F. A1 - Jorgensen, Uffe Grae A1 - Kane, Stephen R. A1 - Kubas, Daniel A1 - Martin, Ralph A1 - Menzies, J. W. A1 - Pollard, R. A1 - Sahu, K. C. A1 - Wambsganss, Joachim A1 - Watson, R. A1 - Williams, A. T1 - OGLE-2003-BLG-238 : Microlensing mass estimate of an isolated star N2 - Microlensing is the only known direct method to measure the masses of stars that lack visible companions. In terms of microlensing observables, the mass is given by M (c(2)/4G)(r) over tilde (E)theta(E) and so requires the measurement of both the angular Einstein radius theta(E) and the projected Einstein radius (r) over tilde (E). Simultaneous measurement of these two parameters is extremely rare. Here we analyze OGLE-2003-BLG-238, a spectacularly bright (I-min 10.3), high-magnification (A(max) 170) microlensing event. Pronounced finite-source effects permit a measurement of theta(E) = 650 muas. Although the timescale of the event is only t(E) 38 days, one can still obtain weak constraints on the microlens parallax: 4.4 AU < <(r)over tilde>(E) < 18 AU at the 1 σ level. Together these two parameter measurements yield a range for the lens mass of 0.36 M-&ODOT; < M < 1.48 M-&ODOT;. As was the case for MACHO- LMC-5, the only other single star (apart from the Sun) whose mass has been determined from its gravitational effects, this estimate is rather crude. It does, however, demonstrate the viability of the technique. We also discuss future prospects for single-lens mass measurements Y1 - 2004 SN - 0004-637X ER - TY - JOUR A1 - Sackett, Penny D. A1 - Albrow, Michael D. A1 - Beaulieu, Jean-Philippe A1 - Caldwell, John A. R. A1 - Coutures, C. A1 - Dominik, M. A1 - Greenhill, John A1 - Hill, K. A1 - Horne, Keith A1 - Jorgensen, Uffe Grae A1 - Kane, Stephen R. A1 - Kubas, Daniel A1 - Martin, Ralph A1 - Menzies, J. W. A1 - Pollard, K. R. A1 - Sahu, K. C. A1 - Wambsganß, Joachim A1 - Watson, R. A1 - Williams, A. T1 - PLANET II : a microlensing and transit search for extrasolar planets N2 - Due to their extremely small luminosity compared to the stars they orbit, planets outside our own Solar System are extraordinarily difficult to detect directly in optical light. Careful photometric monitoring of distant stars, however, can reveal the presence of exoplanets via the microlensing or eclipsing effects they induce. The international PLANET collaboration is performing such monitoring using a cadre of semi-dedicated telescopes around the world. Their results constrain the number of gas giants orbiting 1-7 AU from the most typical stars in the Galaxy. Upgrades in the program are opening regions of ''exoplanet discovery space'' - toward smaller masses and larger orbital radii - that are inaccessible to the Doppler velocity technique. Y1 - 2003 UR - http://arxiv.org/pdf/astro-ph/0211098 ER - TY - JOUR A1 - Archambault, S. A1 - Archer, A. A1 - Benbow, W. A1 - Bird, R. A1 - Bourbeau, E. A1 - Brantseg, T. A1 - Buchovecky, M. A1 - Buckley, J. H. A1 - Bugaev, V. A1 - Byrum, K. A1 - Cerruti, M. A1 - Christiansen, J. L. A1 - Connolly, M. P. A1 - Cui, W. A1 - Daniel, M. K. A1 - Feng, Q. A1 - Finley, J. P. A1 - Fleischhack, H. A1 - Fortson, L. A1 - Furniss, A. A1 - Geringer-Sameth, A. A1 - Griffin, S. A1 - Grube, J. A1 - Hütten, M. A1 - Hakansson, N. A1 - Hanna, D. A1 - Hervet, O. A1 - Holder, J. A1 - Hughes, G. A1 - Hummensky, B. A1 - Johnson, C. A. A1 - Kaaret, P. A1 - Kar, P. A1 - Kelley-Hoskins, N. A1 - Kertzman, M. A1 - Kieda, D. A1 - Koushiappas, S. A1 - Krause, M. A1 - Krennrich, F. A1 - Lang, M. J. A1 - Lin, T. T. Y. A1 - McArthur, S. A1 - Moriarty, P. A1 - Mukherjee, R. A1 - Nieto, D. A1 - Ong, R. A. A1 - Otte, A. N. A1 - Park, N. A1 - Pohl, M. A1 - Popkow, A. A1 - Pueschel, Elisa A1 - Quinn, J. A1 - Ragan, K. A1 - Reynolds, P. T. A1 - Richards, G. T. A1 - Roache, E. A1 - Rulten, C. A1 - Sadeh, I. A1 - Santander, M. A1 - Sembroski, G. H. A1 - Shahinyan, K. A1 - Smith, A. W. A1 - Staszak, D. A1 - Telezhinsky, Igor O. A1 - Trepanier, S. A1 - Tucci, J. V. A1 - Tyler, J. A1 - Wakely, S. P. A1 - Weinstein, A. A1 - Wilcox, P. A1 - Williams, D. A. A1 - Zitzer, B. T1 - Dark matter constraints from a joint analysis of dwarf Spheroidal galaxy observations with VERITAS JF - Physical review : D, Particles, fields, gravitation, and cosmology N2 - We present constraints on the annihilation cross section of weakly interacting massive particles dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of similar to 230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is 1.35 x 10(-23) cm(3) s(-1) at 1 TeV for the bottom quark (b (b) over bar) final state, 2.85 x 10(-24) cm(3) s(-1) at 1 TeV for the tau lepton (tau+tau(-)) final state and 1.32 x 10-25 cm(3) s(-1) at 1 TeV for the gauge boson (gamma gamma) final state. Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevD.95.082001 SN - 2470-0010 SN - 2470-0029 VL - 95 IS - 8 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Williams, Daniel A1 - Escudero, Paola T1 - A cross-dialectal acoustic comparison of vowels in Northern and Southern British English JF - The journal of the Acoustical Society of America N2 - This study compares the duration and first two formants (F1 and F2) of 11 nominal monophthongs and five nominal diphthongs in Standard Southern British English (SSBE) and a Northern English dialect. F1 and F2 trajectories were fitted with parametric curves using the discrete cosine transform (DCT) and the zeroth DCT coefficient represented formant trajectory means and the first DCT coefficient represented the magnitude and direction of formant trajectory change to characterize vowel inherent spectral change (VISC). Cross-dialectal comparisons involving these measures revealed significant differences for the phonologically back monophthongs /D, , , u:/ and also /3z:/ and the diphthongs /eI, e, aI, I/. Most cross-dialectal differences are in zeroth DCT coefficients, suggesting formant trajectory means tend to characterize such differences, while first DCT coefficient differences were more numerous for diphthongs. With respect to VISC, the most striking differences are that /u:/is considerably more diphthongized in the Northern dialect and that the F2 trajectory of /e/proceeds in opposite directions in the two dialects. Cross-dialectal differences were found to be largely unaffected by the consonantal context in which the vowels were produced. The implications of the results are discussed in relation to VISC, consonantal context effects and speech perception. (c) 2014 Acoustical Society of America. Y1 - 2014 U6 - https://doi.org/10.1121/1.4896471 SN - 0001-4966 SN - 1520-8524 VL - 136 IS - 5 SP - 2751 EP - 2761 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Williams, Daniel A1 - Escudero, Paola T1 - Influences of listeners' native and other dialects on cross-language vowel perception JF - Frontiers in psychology KW - non-native speech perception KW - native dialects KW - non-native dialects KW - speech production KW - acoustic phonetics Y1 - 2014 U6 - https://doi.org/10.3389/fpsyg.2014.01065 SN - 1664-1078 VL - 5 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Kashima, Eri A1 - Williams, Daniel A1 - Ellison, T. Mark A1 - Schokkin, Dineke A1 - Escudero, Paola T1 - Uncovering the acoustic vowel space of a previously undescribed language: The vowels of Nambo JF - The journal of the Acoustical Society of America N2 - This study presents the first acoustic description of the vowel space of a Papuan language—Nambo, spoken in southern Papua New Guinea—based on duration and first and second formant measurements from 19 adult male and female speakers across three age groups (young, middle-aged, senior). Phonemically, Nambo has six full vowels /i, e, æ, ɑ, o, u/ and a reduced vowel tentatively labeled /ə/. Unlike the full vowels, the quality of /ə/ showed great variation: seniors' and young females' realizations tended to be more open and retracted than those by young males, while middle-aged speakers' productions fell between these two variants. Y1 - 2016 U6 - https://doi.org/10.1121/1.4954395 SN - 0001-4966 SN - 1520-8524 VL - 139 SP - EL252 EP - EL256 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Elvin, Jaydene A1 - Williams, Daniel A1 - Escudero, Paola T1 - Dynamic acoustic properties of monophthongs and diphthongs in Western Sydney Australian English JF - The journal of the Acoustical Society of America N2 - This study provides a thorough acoustic analysis of the 18 Australian English monophthongs and diphthongs produced in a variety of phonetic contexts by young adult speakers from Western Sydney. The 18 vowels are well separated by duration and dynamic formant trajectory information. Vowel durations and formant trajectories were affected by the consonantal context in which the vowels were produced, particularly those produced in the /hVd/ context. Finally, the results indicate that capturing aspects of vowel inherent spectral change may be useful in future cross-dialectal and cross-linguistic studies. (C) 2016 Acoustical Society of America. Y1 - 2016 U6 - https://doi.org/10.1121/1.4952387 SN - 0001-4966 SN - 1520-8524 VL - 140 SP - 576 EP - 581 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Mayr, Robert A1 - Morris, Jonathan A1 - Mennen, Ineke A1 - Williams, Daniel T1 - Disentangling the effects of long-term language contact and individual bilingualism: The case of monophthongs in Welsh and English JF - International journal of bilingualism : cross-disciplinary, cross-linguistic studies of language behavior N2 - Aims and objectives: This study investigates the effects of individual bilingualism and long-term language contact on monophthongal vowel productions in English and Welsh. Design: To this end, we recorded the Welsh and English vowel productions of two sets of Welsh-English bilinguals differing in home language use, as well as the English vowel productions of English monolinguals. Data and analysis: The data were analysed acoustically, with a focus on spectral and temporal properties. Comparisons were then made within each language and cross-linguistically. Findings: The results of a cross-linguistic acoustic comparison revealed a high degree of convergence in the monophthong systems of Welsh and English, but also some language-specific categories. Interestingly, at the individual level we found no effect of linguistic experience on vowel production: the two sets of bilinguals and the English monolinguals did not differ in their realisation of English vowels, and the two sets of bilinguals did not differ in their realisation of Welsh vowels. Implications: The findings demonstrate pervasive phonetic convergence in a language contact situation with a historical substrate. They also indicate that a homogeneous peer group with shared values can override the effects of individual linguistic experience. KW - Acoustic analysis KW - experience KW - language KW - phonetic convergence KW - vowel productions KW - Welsh-English bilingualism Y1 - 2017 U6 - https://doi.org/10.1177/1367006915614921 SN - 1367-0069 SN - 1756-6878 VL - 21 SP - 245 EP - 267 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Hosseinzadeh, Griffin A1 - Cowperthwaite, Philip S. A1 - Gomez, Sebastian A1 - Villar, Victoria Ashley A1 - Nicholl, Matt A1 - Margutti, Raffaella A1 - Berger, Edo A1 - Chornock, Ryan A1 - Paterson, Kerry A1 - Fong, Wen-fai A1 - Savchenko, Volodymyr A1 - Short, Phil A1 - Alexander, Kate D. A1 - Blanchard, Peter K. A1 - Braga, Joao A1 - Calkins, Michael L. A1 - Cartier, Regis A1 - Coppejans, Deanne L. A1 - Eftekhari, Tarraneh A1 - Laskar, Tanmoy A1 - Ly, Chun A1 - Patton, Locke A1 - Pelisoli, Ingrid Domingos A1 - Reichart, Daniel E. A1 - Terreran, Giacomo A1 - Williams, Peter K. G. T1 - Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters N2 - On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at d(L) = 156 +/- 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at d(L) = 377 +/- 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field gamma-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the gamma-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg(2) are likely essential. KW - binaries: close KW - gravitational waves KW - methods: observational KW - stars: black holes KW - stars: neutron Y1 - 2019 U6 - https://doi.org/10.3847/2041-8213/ab271c SN - 2041-8205 SN - 2041-8213 VL - 880 IS - 1 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Mokari, Payam Ghaffarvand A1 - Gafos, Adamantios I. A1 - Williams, Daniel T1 - Perceptuomotor compatibility effects in vowels BT - effects of consonantal context and acoustic proximity of response and distractor JF - JASA Express Letters N2 - In a cue-distractor task, speakers' response times (RTs) were found to speed up when they perceived a distractor syllable whose vowel was identical to the vowel in the syllable they were preparing to utter. At a more fine-grained level, subphonemic congruency between response and distractor-defined by higher number of shared phonological features or higher acoustic proximity-was also found to be predictive of RT modulations. Furthermore, the findings indicate that perception of vowel stimuli embedded in syllables gives rise to robust and more consistent perceptuomotor compatibility effects (compared to isolated vowels) across different response-distractor vowel pairs. KW - speech Y1 - 2021 U6 - https://doi.org/10.1121/10.0003039 SN - 2691-1191 VL - 1 IS - 1 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Ghaffarvand-Mokari, Payam A1 - Gafos, Adamantios I. A1 - Williams, Daniel T1 - Perceptuomotor compatibility effects in vowels BT - beyond phonemic identity JF - Attention, perception, & psychophysics N2 - Perceptuomotor compatibility between phonemically identical spoken and perceived syllables has been found to speed up response times (RTs) in speech production tasks. However, research on compatibility effects between perceived and produced stimuli at the subphonemic level is limited. Using a cue-distractor task, we investigated the effects of phonemic and subphonemic congruency in pairs of vowels. On each trial, a visual cue prompted individuals to produce a response vowel, and after the visual cue appeared a distractor vowel was auditorily presented while speakers were planning to produce the response vowel. The results revealed effects on RTs due to phonemic congruency (same vs. different vowels) between the response and distractor vowels, which resemble effects previously seen for consonants. Beyond phonemic congruency, we assessed how RTs are modulated as a function of the degree of subphonemic similarity between the response and distractor vowels. Higher similarity between the response and distractor in terms of phonological distance-defined by number of mismatching phonological features-resulted in faster RTs. However, the exact patterns of RTs varied across response-distractor vowel pairs. We discuss how different assumptions about phonological feature representations may account for the different patterns observed in RTs across response-distractor pairs. Our findings on the effects of perceived stimuli on produced speech at a more detailed level of representation than phonemic identity necessitate a more direct and specific formulation of the perception-production link. Additionally, these results extend previously reported perceptuomotor interactions mainly involving consonants to vowels. KW - speech perception KW - speech production KW - psycholinguistics Y1 - 2020 U6 - https://doi.org/10.3758/s13414-020-02014-1 SN - 1943-3921 SN - 1943-393X VL - 82 IS - 5 SP - 2751 EP - 2764 PB - Springer CY - New York ER - TY - GEN A1 - Driel-Gesztelyi, L. van A1 - Baker, Daniel N. A1 - Török, Tibor A1 - Pariat, Etienne A1 - Green, L. M. A1 - Williams, D. R. A1 - Carlyle, J. A1 - Valori, G. A1 - Démoulin, Pascal A1 - Matthews, S. A. A1 - Kliem, Bernhard A1 - Malherbe, J.-M. T1 - Magnetic reconnection driven by filament eruption in the 7 June 2011 event T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - During an unusually massive filament eruption on 7 June 2011, SDO/AIA imaged for the first time significant EUV emission around a magnetic reconnection region in the solar corona. The reconnection occurred between magnetic fields of the laterally expanding CME and a neighbouring active region. A pre-existing quasi-separatrix layer was activated in the process. This scenario is supported by data-constrained numerical simulations of the eruption. Observations show that dense cool filament plasma was re-directed and heated in situ, producing coronal-temperature emission around the reconnection region. These results provide the first direct observational evidence, supported by MHD simulations and magnetic modelling, that a large-scale re-configuration of the coronal magnetic field takes place during solar eruptions via the process of magnetic reconnection. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 608 KW - MHD KW - instabilities KW - Sun: activity KW - magnetic fields KW - coronal mass ejections (CMEs) KW - filaments KW - methods: numerical KW - data analysis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-415671 IS - 608 SP - 502 EP - 503 ER - TY - JOUR A1 - Williams, Daniel Philip A1 - Escudero, Paola A1 - Gafos, Adamantios I. T1 - Spectral change and duration as cues in Australian English listeners' front vowel categorization JF - The journal of the Acoustical Society of America N2 - Australian English /iː/, /ɪ/, and /ɪə/ exhibit almost identical average first (F1) and second (F2) formant frequencies and differ in duration and vowel inherent spectral change (VISC). The cues of duration, F1 × F2 trajectory direction (TD) and trajectory length (TL) were assessed in listeners' categorization of /iː/ and /ɪə/ compared to /ɪ/. Duration was important for distinguishing both /iː/ and /ɪə/ from /ɪ/. TD and TL were important for categorizing /iː/ versus /ɪ/, whereas only TL was important for /ɪə/ versus /ɪ/. Finally, listeners' use of duration and VISC was not mutually affected for either vowel compared to /ɪ/. Y1 - 2018 U6 - https://doi.org/10.1121/1.5055019 SN - 0001-4966 SN - 1520-8524 VL - 144 IS - 3 SP - EL215 EP - EL221 PB - American Institute of Physics CY - Melville ER - TY - GEN A1 - Williams, Daniel A1 - Escudero, Paola A1 - Gafos, Adamantios I. T1 - Perceptual sensitivity to spectral change in Australian English close front vowels BT - an electroencephalographic investigation T2 - 19 th annual conference of the international speech communicaton association (INTERSPEECH 2018), VOLS 1-6: Speech research for emerging marjets in multilingual societies N2 - Speech scientists have long noted that the qualities of naturally-produced vowels do not remain constant over their durations regardless of being nominally "monophthongs" or "diphthongs". Recent acoustic corpora show that there are consistent patterns of first (F1) and second (F2) formant frequency change across different vowel categories. The three Australian English (AusE) close front vowels /i:, 1, i/ provide a striking example: while their midpoint or mean F1 and F2 frequencies are virtually identical, their spectral change patterns distinctly differ. The results indicate that, despite the distinct patterns of spectral change of AusE /i:, i, la/ in production, its perceptual relevance is not uniform, but rather vowel-category dependent. KW - vowels KW - pre-attentive discrimination KW - speech perception KW - speech acoustics KW - English dialects Y1 - 2018 SN - 978-1-5108-7221-9 U6 - https://doi.org/10.21437/Interspeech.2018-2505 SN - 2308-457X SP - 1442 EP - 1446 PB - ISCA-International Speech Communication Association CY - Baixas ER -