942 results on '"J. Galvin"'
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102. The Multistate Hard Core Model on a Regular Tree.
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David J. Galvin, Fabio Martinelli, Kavita Ramanan, and Prasad Tetali
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- 2011
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103. An upper bound for the number of independent sets in regular graphs.
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David J. Galvin
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- 2009
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104. Matchings and independent sets of a fixed size in regular graphs.
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Teena Carroll, David J. Galvin, and Prasad Tetali
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- 2009
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105. Perception of Sung Speech in Bimodal Cochlear Implant Users
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Joseph D. Crew, John J. Galvin, and Qian-Jie Fu
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Otorhinolaryngology ,RF1-547 - Abstract
Combined use of a hearing aid (HA) and cochlear implant (CI) has been shown to improve CI users’ speech and music performance. However, different hearing devices, test stimuli, and listening tasks may interact and obscure bimodal benefits. In this study, speech and music perception were measured in bimodal listeners for CI-only, HA-only, and CI + HA conditions, using the Sung Speech Corpus, a database of monosyllabic words produced at different fundamental frequencies. Sentence recognition was measured using sung speech in which pitch was held constant or varied across words, as well as for spoken speech. Melodic contour identification (MCI) was measured using sung speech in which the words were held constant or varied across notes. Results showed that sentence recognition was poorer with sung speech relative to spoken, with little difference between sung speech with a constant or variable pitch; mean performance was better with CI-only relative to HA-only, and best with CI + HA. MCI performance was better with constant words versus variable words; mean performance was better with HA-only than with CI-only and was best with CI + HA. Relative to CI-only, a strong bimodal benefit was observed for speech and music perception. Relative to the better ear, bimodal benefits remained strong for sentence recognition but were marginal for MCI. While variations in pitch and timbre may negatively affect CI users’ speech and music perception, bimodal listening may partially compensate for these deficits.
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- 2016
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106. Identification and Cost of Disposable Endourological Devices for Nephrolithiasis: A Cross-Sectional Study Among Urological Trainees
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E Maccraith, Niall F Davis, Cliodhna Brown, David J Galvin, David M Quinlan, Gerald M Lennon, and David W Mulvin
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disposable devices ,endourology ,health economics ,urology training ,Medicine - Abstract
Introduction: Knowledge on health economics among urology trainees is not formally assessed. The cost of commonly utilised endourological devices may not be considered by trainees. Aim: The present study was conducted with the aim to assess whether urology trainees were knowledgeable on identification and cost of commonly used disposable devices in the management of nephrolithiasis. Materials and Methods: Forty urology trainees in Ireland were invited to complete a visual online questionnaire on the identification of 10 frequently utilised disposable endourological devices. In addition, trainees were requested to estimate the cost of 12 disposable endourological devices. Responses were stratified according to trainee grade and urological subspecialty of interest. Data are presented as a mean ± standard deviation. Results: The response rate was 70% (28/40). Endourology was the subspecialty of interest in 21% (n= 6). No trainee correctly identified all 10 endourological devices and the mean test score was 5.32 ± 2.28. No trainee accurately estimated the cost for all 12 devices assessed. The cost of endourological devices was underestimated by €67.13 ± €60.76 per device. A total of 54% (n=15) of trainees underestimated the total cost of disposable devices used during standard flexible ureterorenoscopy, laser lithotripsy and JJ stent insertion by €303.66 ± €113.83. Conclusion: Our findings indicate deficiencies in trainee knowledge on endourological devices and their associated costs. Incorporating a health economics module into postgraduate urology training may familiarise trainees with healthcare expenditure within their departments.
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- 2016
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107. Effects of Within-Talker Variability on Speech Intelligibility in Mandarin-Speaking Adult and Pediatric Cochlear Implant Patients
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Qiaotong Su, John J. Galvin, Guoping Zhang, Yongxin Li, and Qian-Jie Fu
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Otorhinolaryngology ,RF1-547 - Abstract
Cochlear implant (CI) speech performance is typically evaluated using well-enunciated speech produced at a normal rate by a single talker. CI users often have greater difficulty with variations in speech production encountered in everyday listening. Within a single talker, speaking rate, amplitude, duration, and voice pitch information may be quite variable, depending on the production context. The coarse spectral resolution afforded by the CI limits perception of voice pitch, which is an important cue for speech prosody and for tonal languages such as Mandarin Chinese. In this study, sentence recognition from the Mandarin speech perception database was measured in adult and pediatric Mandarin-speaking CI listeners for a variety of speaking styles: voiced speech produced at slow, normal, and fast speaking rates; whispered speech; voiced emotional speech; and voiced shouted speech. Recognition of Mandarin Hearing in Noise Test sentences was also measured. Results showed that performance was significantly poorer with whispered speech relative to the other speaking styles and that performance was significantly better with slow speech than with fast or emotional speech. Results also showed that adult and pediatric performance was significantly poorer with Mandarin Hearing in Noise Test than with Mandarin speech perception sentences at the normal rate. The results suggest that adult and pediatric Mandarin-speaking CI patients are highly susceptible to whispered speech, due to the lack of lexically important voice pitch cues and perhaps other qualities associated with whispered speech. The results also suggest that test materials may contribute to differences in performance observed between adult and pediatric CI users.
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- 2016
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108. Effects of Monaural Asymmetry and Target–Masker Similarity on Binaural Advantage in Children and Adults With Normal Hearing
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Qian-Jie Fu, Quinton Gopen, Ji-Sheng Liu, Ya-Feng Yu, Yi Li, Fei Ye, John J. Galvin, and Duo-Duo Tao
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Adult ,Male ,Auditory perception ,Linguistics and Language ,medicine.medical_specialty ,business.product_category ,Speech perception ,Hearing loss ,media_common.quotation_subject ,Monaural ,Audiology ,behavioral disciplines and activities ,Language and Linguistics ,Speech and Hearing ,Hearing ,Perception ,otorhinolaryngologic diseases ,medicine ,Humans ,Active listening ,Child ,Hearing Loss ,Headphones ,media_common ,Hearing Tests ,Auditory Perception ,Speech Perception ,Female ,medicine.symptom ,business ,Psychology ,Binaural recording ,psychological phenomena and processes - Abstract
PurposeFor colocated targets and maskers, binaural listening typically offers a small but significant advantage over monaural listening. This study investigated how monaural asymmetry and target–masker similarity may limit binaural advantage in adults and children.MethodTen Mandarin-speaking Chinese adults (aged 22–27 years) and 12 children (aged 7–14 years) with normal hearing participated in the study. Monaural and binaural speech recognition thresholds (SRTs) were adaptively measured for colocated competing speech. The target–masker sex was the same or different. Performance was measured using headphones for three listening conditions: left ear, right ear, and both ears. Binaural advantage was calculated relative to the poorer or better ear.ResultsMean SRTs were significantly lower for adults than children. When the target–masker sex was the same, SRTs were significantly lower with the better ear than with the poorer ear or both ears (p< .05). When the target–masker sex was different, SRTs were significantly lower with the better ear or both ears than with the poorer ear (p< .05). Children and adults similarly benefitted from target–masker sex differences. Substantial monaural asymmetry was observed, but the effects of asymmetry on binaural advantage were similar between adults and children. Monaural asymmetry was significantly correlated with binaural advantage relative to the poorer ear (p= .004), but not to the better ear (p= .056).ConclusionsBinaural listening may offer little advantage (or even a disadvantage) over monaural listening with the better ear, especially when competing talkers have similar vocal characteristics. Monaural asymmetry appears to limit binaural advantage in listeners with normal hearing, similar to observations in listeners with hearing impairment. While language development may limit perception of competing speech, it does not appear to limit the effects of monaural asymmetry or target–masker sex on binaural advantage.
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- 2020
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109. Labor’s Legacy: The Construction of Subnational Work Regulation
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Daniel J. Galvin
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Organizational Behavior and Human Resource Management ,Labour economics ,Strategy and Management ,Labour law ,05 social sciences ,State legislature ,0506 political science ,Politics ,Work (electrical) ,Management of Technology and Innovation ,Political science ,0502 economics and business ,050602 political science & public administration ,050207 economics - Abstract
In recent decades, much of the authority to regulate the workplace has shifted from national-level labor law to state-level employment law. What contributions, if any, did labor unions make to this historic shift in workplace governance? The author uses quantitative and qualitative analyses to test hypotheses and move incrementally closer toward drawing causal inferences. In the first part, he finds a strong statistical relationship between union density and state employment law enactments. Next, analyzing the cases the model identifies as “deviant” (Pennsylvania and Maine), he uses systematic process tracing to test the hypothesis that labor unions were integral players in legislative campaigns for stronger employment laws. Strong evidence supports the hypothesis that labor unions, even as they declined, contributed to the construction of this new system of subnational work regulation—arguably one of their most significant and durable legacies.
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- 2020
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110. Party Domination and Base Mobilization: Donald Trump and Republican Party Building in a Polarized Era
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Daniel J. Galvin
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Mobilization ,Sociology and Political Science ,Political science ,Political economy ,General Social Sciences ,Base (topology) - Abstract
Since the 2016 election, President Trump has achieved unparalleled dominance over the Republican Party. He has also given his party a central role in his reelection campaign and invested heavily in its organizational capacities. This dual approach to party leadership – domination paired with organizational investment – bears a strong resemblance to the way every Republican president since Eisenhower interacted with his party, different only in degree. Where Trump’s party leadership diverges qualitatively from past patterns is in its apparent purposes. Previous Republican presidents dominated and invested in their party for the explicit purpose of building a new majority in American politics. Reaching out to new demographic groups and trying to persuade them to join the party was integral to this project. Trump, in contrast, has (thus far) predominantly pursued a base-mobilization strategy. Rather than fan out horizontally in search of new groups to join the party coalition, Trump’s strategy drills down vertically to penetrate and deepen his base. Instead of trying to diversify the GOP and extend its reach, his strategy aims to swell the number of like-minded supporters who are active in electoral and party politics (while suppressing, demobilizing, and delegitimizing the opposition party). By setting into motion a mutually reinforcing cycle of party domination and base mobilization, and amplifying its effects through organizational investment, Trump has turned his party into a formidable vehicle for advancing his personal purposes and augmenting his power – while raising troubling questions about the stability of American democracy. This article examines Trump’s party leadership to date, compares it to previous presidential party leadership projects, and considers the implications.
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- 2020
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111. The Political Effects of Policy Drift: Policy Stalemate and American Political Development
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Jacob S. Hacker and Daniel J. Galvin
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Gridlock ,History ,Sociology and Political Science ,media_common.quotation_subject ,Polarization (politics) ,Stalemate ,Politics ,Politics of the United States ,Political science ,Political economy ,Polity ,Disability insurance ,Welfare ,media_common - Abstract
In recent years, scholars have made major progress in understanding the dynamics of “policy drift”—the transformation of a policy's outcomes due to the failure to update its rules or structures to reflect changing circumstances. Drift is a ubiquitous mode of policy change in America's gridlock-prone polity, and its causes are now well understood. Yet surprisingly little attention has been paid to the political consequences of drift—to the ways in which drift, like the adoption of new policies, may generate its own feedback effects. In this article, we seek to fill this gap. We first outline a set of theoretical expectations about how drift should affect downstream politics. We then examine these dynamics in the context of four policy domains: labor law, health care, welfare, and disability insurance. In each, drift is revealed to be both mobilizing and constraining: While it increases demands for policy innovation, group adaptation, and new group formation, it also delimits the range of possible paths forward. These reactions to drift, in turn, generate new problems, cleavages, and interest alignments that alter subsequent political trajectories. Whether formal policy revision or further stalemate results, these processes reveal key mechanisms through which American politics and policy develop.
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- 2020
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112. Effect of Ipsilateral, Contralateral or Bilateral Repetitive Transcranial Magnetic Stimulation in Patients with Lateralized Tinnitus: A Placebo-Controlled Randomized Study
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Yi Li, Yong-Cong Shen, John J. Galvin, Ji-Sheng Liu, and Duo-Duo Tao
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General Neuroscience ,otorhinolaryngologic diseases ,subjective tinnitus ,lateralized tinnitus ,repetitive transcranial magnetic stimulation ,visual analogue scale - Abstract
The relative benefit of ipsilateral, contralateral, and bilateral repetitive transcranial magnetic stimulation (rTMS) for tinnitus treatment remains unclear, especially for patients with lateralized tinnitus. In this study, we compared outcomes after 10 sessions of 1-Hz rTMS at 110% of resting motor threshold over a two-week period. In total, 104 right-handed patients with lateralized subjective tinnitus were randomly divided into four groups according to rTMS treatment: Left (n = 29), Right (n = 23), Bilateral (n = 30), and Sham stimulation (n = 22). Outcomes included estimates of tinnitus severity, psychological state, and psychoacoustic measures. Patients with left- or right-sided tinnitus were similarly distributed across treatment groups. There were no significant changes in outcome measures for the Right or Sham treatment groups. For the Left and Bilateral groups, tinnitus severity was significantly lower after treatment (p < 0.05). The reduction in tinnitus severity was largest for ipsilateral treatment in the Left group. The overall response rate was 56.1% for the Left group, 46.7% for the Bilateral group, 8.3% for the Right group, and 8.3% for the Sham group. For the Left and Bilateral groups, the response rate was larger for patients with left- than right-sided tinnitus. Changes in tinnitus severity were best predicted by changes in anxiety, depression, and the loudness of the tinnitus. The results suggests that rTMS on the left temporoparietal cortex is more effective for patients with left-sided than with right-sided tinnitus.
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- 2022
113. Constraining the Radio Properties of the $z$=6.44 QSO VIK J2318$-$3113
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Luca Ighina, James K. Leung, Jess W. Broderick, Guillaume Drouart, Nick Seymour, Silvia Belladitta, Alessandro Caccianiga, Emil Lenc, Alberto Moretti, Tao An, Tim J. Galvin, George H. Heald, Minh T. Huynh, David McConnell, Tara Murphy, Joshua Pritchard, Benjamin Quici, Stas S. Shabala, Steven J. Tingay, Ross J. Turner, Yuanming Wang, and Sarah V. White
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Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
The recent detection of the quasi-stellar object (QSO) VIKING J231818.3$-$311346 (hereafter VIK J2318$-$3113) at redshift $z=6.44$ in the Rapid ASKAP Continuum Survey (RACS) uncovered its radio-loud nature, making it one of the most distant known to date in this class. By using data from several radio surveys of the Galaxy and Mass Assembly 23$^\mathrm{h}$ field and from dedicated follow-up, we were able to constrain the radio spectrum of VIK J2318$-$3113 in the observed range $\sim$0.1--10 GHz. At high frequencies (0.888--5.5 GHz in the observed frame) the QSO presents a steep spectrum ($\alpha_{\rm r}$=1.24, with $S_\nu\propto \nu^{-\alpha_{\rm r}}$), while at lower frequencies (0.4--0.888 GHz in the observed frame) it is nearly flat. The overall spectrum can be modelled by either a curved function with a rest-frame turnover around 5 GHz, or with a smoothly varying double power law that is flat below a rest-frame break frequency of about 20 GHz and which significantly steepens above it. Based on the model adopted, we estimated that the radio jets of VIK J2318$-$3113 must be a few hundred years old, in the case of a turnover, or less than few$\times$10$^4$ years, in the case of a break in the spectrum. Having multiple observations at two frequencies (888 MHz and 5.5 GHz), we further investigated the radio variability previously reported for this source. We found that the marginally significant flux density variations are consistent with the expectations from refractive interstellar scintillation, even though relativistic effects related to the orientation of the source may still play a non-negligible role. Further radio and X-ray observations are required to conclusively discern the nature of this variation., Comment: Accepted for publication in A&A
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- 2022
114. The Evolutionary Map of the Universe Pilot Survey – ADDENDUM
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Ray P. Norris, Joshua Marvil, J. D. Collier, Anna D. Kapińska, Andrew N. O’Brien, L. Rudnick, Heinz Andernach, Jacobo Asorey, Michael J. I. Brown, Marcus Brüggen, Evan Crawford, Jayanne English, Syed Faisal ur Rahman, Miroslav D. Filipović, Yjan Gordon, Gülay Gürkan, Catherine Hale, Andrew M. Hopkins, Minh T. Huynh, Kim HyeongHan, M. James Jee, Bärbel S. Koribalski, Emil Lenc, Kieran Luken, David Parkinson, Isabella Prandoni, Wasim Raja, Thomas H. Reiprich, Christopher J. Riseley, Stanislav S. Shabala, Jaimie R. Sheil, Tessa Vernstrom, Matthew T. Whiting, James R. Allison, C. S. Anderson, Lewis Ball, Martin Bell, John Bunton, T. J. Galvin, Neeraj Gupta, Aidan Hotan, Colin Jacka, Peter J. Macgregor, Elizabeth K. Mahony, Umberto Maio, Vanessa Moss, M. Pandey-Pommier, and Maxim A. Voronkov
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Space and Planetary Science ,Astronomy and Astrophysics - Published
- 2022
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115. Wide-band spectral variability of peaked spectrum sources
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K Ross, N Hurley-Walker, N Seymour, J R Callingham, T J Galvin, and M Johnston-Hollitt
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Scattering ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - astrophysics of galaxies ,Astrophysics::Instrumentation and Methods for Astrophysics ,Galaxies - active ,FOS: Physical sciences ,Radio continuum - general ,Astronomy and Astrophysics ,Radio continuum - galaxies ,Astrophysics - high energy astrophysical phenomena ,Radio continuum - ISM - Abstract
Characterising spectral variability of radio sources is a technique that offers the ability to determine the astrophysics of the intervening media, source structure, emission and absorption processes. We present broadband (0.072--10 GHz) spectral variability of 15 peaked-spectrum (PS) sources with the Australia Telescope Compact Array (ATCA) and the Murchison Widefield Array (MWA). These 15 PS sources were observed quasi-contemporaneously with ATCA and the MWA four to six times during 2020 with approximately a monthly cadence. Variability was not detected at 1--10GHz frequencies but 13 of the 15 targets show significant variability with the MWA at megahertz frequencies. We conclude the majority of variability seen at megahertz frequencies is due to refractive interstellar scintillation of a compact component ~25 mas across. We also identify four PS sources that show a change in their spectral shape at megahertz frequencies. Three of these sources are consistent with a variable optical depth from an inhomogeneous free-free absorbing cloud around the source. One PS source with a variable spectral shape at megahertz frequencies is consistent with an ejection travelling along the jet. We present spectral variability as a method for determining the physical origins of observed variability and for providing further evidence to support absorption models for PS sources where spectral modelling alone is insufficient., Comment: Accepted for publication in MNRAS. 17 pages, 10 figures
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- 2022
116. Radio fossils, relics, and haloes in Abell 3266: cluster archaeology with ASKAP-EMU and the ATCA
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C J Riseley, E Bonnassieux, T Vernstrom, T J Galvin, A Chokshi, A Botteon, K Rajpurohit, S W Duchesne, A Bonafede, L Rudnick, M Hoeft, B Quici, D Eckert, M Brienza, C Tasse, E Carretti, J D Collier, J M Diego, L Di Mascolo, A M Hopkins, M Johnston-Hollitt, R R Keel, B S Koribalski, T H Reiprich, Australian Government, CSIRO Land and Water (Australia), Science and Industry Endowment Fund (Australia), European Research Council, European Commission, Netherlands Organization for Scientific Research, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Australian Research Council, Department of Energy (US), Ministerio de Educación y Ciencia (España), Science and Technology Facilities Council (UK), University of Illinois, Higher Education Funding Council for England, Kavli Institute for Particle Astrophysics and Cosmology, The Ohio State University, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Ministério da Ciência, Tecnologia e Inovação (Brasil), and German Research Foundation
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Galaxies: clusters: individual: Abell 3266 ,Astrophysics - astrophysics of galaxies ,Astrophysics - cosmology and nongalactic astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,X-rays - galaxies - clusters ,Galaxies - clusters - general: Galaxies - clusters - individual ,Space and Planetary Science ,X-rays: galaxies: clusters ,Abell 3266 ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxies: clusters: general ,Galaxies: clusters: intracluster medium ,Galaxies - clusters - intracluster medium - Abstract
Abell 3266 is a massive and complex merging galaxy cluster that exhibits significant substructure. We present new, highly sensitive radio continuum observations of Abell 3266 performed with the Australian Square Kilometre Array Pathfinder (0.8–1.1 GHz) and the Australia Telescope Compact Array (1.1–3.1 GHz). These deep observations provide new insights into recently reported diffuse non-thermal phenomena associated with the intracluster medium, including a ‘wrong-way’ relic, a fossil plasma source, and an as-yet unclassified central diffuse ridge, which we reveal comprises the brightest part of a large-scale radio halo detected here for the first time. The ‘wrong-way’ relic is highly atypical of its kind: it exhibits many classical signatures of a shock-related radio relic, while at the same time exhibiting strong spectral steepening. While radio relics are generally consistent with a quasi-stationary shock scenario, the ‘wrong-way’ relic is not. We study the spectral properties of the fossil plasma source; it exhibits an ultrasteep and highly curved radio spectrum, indicating an extremely aged electron population. The larger scale radio halo fills much of the cluster centre, and presents a strong connection between the thermal and non-thermal components of the intracluster medium, along with evidence of substructure. Whether the central diffuse ridge is simply a brighter component of the halo, or a mini-halo, remains an open question. Finally, we study the morphological and spectral properties of the multiple complex radio galaxies in this cluster in unprecedented detail, tracing their evolutionary history., The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42), which is funded by the Australian Government for operation as a National Facility managed by CSIRO. The Australian SKA Pathfinder is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) that is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site., CJR, EB, and AB acknowledge financial support from the ERC Starting Grant ‘DRANOEL’, number 714245. A. Botteon acknowledges support from the VIDI research programme with project number 639.042.729, which is financed by the Netherlands Organisation for Scientific Research (NWO). KR and MB acknowledge financial support from the ERC Starting Grant ‘MAGCOW’, no. 714196. JMD acknowledges the support of projects PGC2018-101814-B-100 and María de Maeztu, ref. MDM-2017-0765. This research was supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. LDM is supported by the ERC-StG ‘ClustersXCosmo’ grant agreement 716762., This project used public archival data from the Dark Energy Survey (DES). Funding for the DES Projects has been provided by the US Department of Energy, the US National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the DES.
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- 2022
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117. Discovery of Peculiar Radio Morphologies with ASKAP using Unsupervised Machine Learning
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Nikhel Gupta, Minh Huynh, Ray P. Norris, X. Rosalind Wang, Andrew M. Hopkins, Heinz Andernach, Bärbel S. Koribalski, and Tim J. Galvin
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a set of peculiar radio sources detected using an unsupervised machine learning method. We use data from the Australian Square Kilometre Array Pathfinder (ASKAP) telescope to train a self-organizing map (SOM). The radio maps from three ASKAP surveys, Evolutionary Map of Universe pilot survey (EMU-PS), Deep Investigation of Neutral Gas Origins pilot survey (DINGO) and Survey With ASKAP of GAMA-09 + X-ray (SWAG-X), are used to search for the rarest or unknown radio morphologies. We use an extension of the SOM algorithm that implements rotation and flipping invariance on astronomical sources. The SOM is trained using the images of all "complex" radio sources in the EMU-PS which we define as all sources catalogued as "multi-component". The trained SOM is then used to estimate a similarity score for complex sources in all surveys. We select 0.5\% of the sources that are most complex according to the similarity metric, and visually examine them to find the rarest radio morphologies. Among these, we find two new odd radio circle (ORC) candidates and five other peculiar morphologies. We discuss multiwavelength properties and the optical/infrared counterparts of selected peculiar sources. In addition, we present examples of conventional radio morphologies including: diffuse emission from galaxy clusters, and resolved, bent-tailed, and FR-I and FR-II type radio galaxies. We discuss the overdense environment that may be the reason behind the circular shape of ORC candidates., Comment: Accepted in PASA, 23 pages, 16 figures
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- 2022
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118. HST WFC3/Grism Observations of the Candidate Ultra-High-Redshift Radio Galaxy GLEAM J0917-0012
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N. Seymour, G. Drouart, G. Noirot, J. W. Broderick, R. J. Turner, S. S. Shabala, D. K. Stern, S. Bellstedt, S. Driver, L. Davies, C. A. De Breuck, J. A. Afonso, J. D. R. Vernet, and T. J. Galvin
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present Hubble Space Telescope Wide Field Camera 3 photometric and grism observations of the candidate ultra-high-redshift (z>7) radio galaxy, GLEAM J0917-0012. This radio source was selected due to the curvature in its 70-230 MHz, low-frequency Murchison Widefield Array radio spectrum and its faintness in K-band. Follow-up spectroscopic observations of this source with the VLA and ALMA were inconclusive as to its redshift. Our F105W and F0986M imaging observations detect the host of GLEAM J0917-0012 and a companion galaxy, ~one arcsec away. The G102 grism observations reveal a single weak line in each of the spectra of the host and the companion. To help identify these lines we utilised several photometric redshift techniques including template fitting to the grism spectra, fitting the UV-to-radio photometry with galaxy templates plus a synchrotron model, fitting of the UV-to-near-infrared photometry with EAZY, and fitting the radio data alone with RAiSERed. For the host of GLEAM J0917-0012 we find a line at 1.12 micron and the UV-to-radio spectral energy distribution fitting favours solutions at z~2 or z~8. While this fitting shows a weak preference for the lower redshift solution, the models from the higher redshift solution are more consistent with the strength of the spectral line. The redshift constraint by RAiSERed of z>6.5 also supports the interpretation that this line could be Lyman-alpha at z=8.21; however EAZY favours the z~2 solution. We discuss the implications of both solutions. For the companion galaxy we find a line at 0.98 micron and the spectral energy distribution fitting favours solutions at z, 18 pages, 7 figures, 6 tables, accepted for publication in PASA
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- 2022
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119. GaLactic and Extragalactic All-sky Murchison Widefield Array survey eXtended (GLEAM-X) I: Survey description and initial data release
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N. Hurley-Walker, T. J. Galvin, S. W. Duchesne, X. Zhang, J. Morgan, P. J. Hancock, T. An, T. M. O. Franzen, G. Heald, K. Ross, T. Vernstrom, G. E. Anderson, B. M. Gaensler, M. Johnston-Hollitt, D. L. Kaplan, C. J. Riseley, S. J. Tingay, and M. Walker
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Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Article - Abstract
We describe a new low-frequency wideband radio survey of the southern sky. Observations covering 72 - 231 MHz and Declinations south of $+30^\circ$ have been performed with the Murchison Widefield Array "extended" Phase II configuration over 2018 - 2020 and will be processed to form data products including continuum and polarisation images and mosaics, multi-frequency catalogues, transient search data, and ionospheric measurements. From a pilot field described in this work, we publish an initial data release covering 1,447 sq. deg over 4h < RA < 13h, -32.7deg < Dec < -20.7deg. We process twenty frequency bands sampling 72 - 231 MHz, with a resolution of $2'$ - $45"$, and produce a wideband source-finding image across 170 - 231MHz with a root-mean-square noise of $1.27\pm0.15$ mJy/beam. Source-finding yields 78,967 components, of which 71,320 are fitted spectrally. The catalogue has a completeness of 98% at $\sim50$mJy, and a reliability of 98.2% at $5σ$ rising to 99.7% at $7σ$. A catalogue is available from Vizier; images are made available on AAO Data Central, SkyView, and the PASA Datastore. This is the first in a series of data releases from the GLEAM-X survey., 34 pages, 21 figures, 3 tables, accepted for publication in Publications of the Astronomical Society of Australia (PASA)
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- 2022
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120. The GLEAMing of the first supermassive black holes: II. A new sample of high-redshift radio galaxy candidates
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J. W. Broderick, G. Drouart, N. Seymour, T. J. Galvin, N. Wright, A. Carnero Rosell, R. Chhetri, H. Dannerbauer, S. P. Driver, J. S. Morgan, V. A. Moss, S. Prabu, J. M. Afonso, C. De Breuck, B. H. C. Emonts, T. M. O. Franzen, C. M. Gutiérrez, P. J. Hancock, G. H. Heald, N. Hurley-Walker, R. J. Ivison, M. D. Lehnert, G. Noirot, M. Read, S. S. Shabala, D. Stern, W. J. Sutherland, E. Sutorius, R. J. Turner, and J. Vernet
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Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
While unobscured and radio-quiet active galactic nuclei are regularly being found at redshifts $z > 6$, their obscured and radio-loud counterparts remain elusive. We build upon our successful pilot study, presenting a new sample of low-frequency-selected candidate high-redshift radio galaxies (HzRGs) over a sky area twenty times larger. We have refined our selection technique, in which we select sources with curved radio spectra between 72-231 MHz from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. In combination with the requirements that our GLEAM-selected HzRG candidates have compact radio morphologies and be undetected in near-infrared $K_{\rm s}$-band imaging from the Visible and Infrared Survey Telescope for Astronomy Kilo-degree Infrared Galaxy (VIKING) survey, we find 51 new candidate HzRGs over a sky area of approximately 1200 deg$^2$. Our sample also includes two sources from the pilot study: the second-most distant radio galaxy currently known, at $z=5.55$, with another source potentially at $z \sim 8$. We present our refined selection technique and analyse the properties of the sample. We model the broadband radio spectra between 74 MHz and 9 GHz by supplementing the GLEAM data with both publicly available data and new observations from the Australia Telescope Compact Array at 5.5 and 9 GHz. In addition, deep $K_{\rm s}$-band imaging from the High-Acuity Widefield $K$-band Imager (HAWK-I) on the Very Large Telescope and from the Southern Herschel Astrophysical Terahertz Large Area Survey Regions $K_{\rm s}$-band Survey (SHARKS) is presented for five sources. We discuss the prospects of finding very distant radio galaxies in our sample, potentially within the epoch of reionisation at $z \gtrsim 6.5$., 49 pages, 3 figures (one of which is a multi-page figure with 102 separate panels), 9 tables, accepted for publication in PASA
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- 2022
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121. Mysterious Odd Radio Circle near the Large Magellanic Cloud -- An Intergalactic Supernova Remnant?
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Miroslav D Filipović, J L Payne, R Z E Alsaberi, R P Norris, P J Macgregor, L Rudnick, B S Koribalski, D Leahy, L Ducci, R Kothes, H Andernach, L Barnes, I S Bojičić, L M Bozzetto, R Brose, J D Collier, E J Crawford, R M Crocker, S Dai, T J Galvin, F Haberl, U Heber, T Hill, A M Hopkins, N Hurley-Walker, A Ingallinera, T Jarrett, P J Kavanagh, E Lenc, K J Luken, D Mackey, P Manojlović, P Maggi, C Maitra, C M Pennock, S Points, S Riggi, G Rowell, S Safi-Harb, H Sano, M Sasaki, S Shabala, J Stevens, J Th van Loon, N F H Tothill, G Umana, D Urošević, V Velović, T Vernstrom, J L West, and Z Wan
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Space and Planetary Science ,QB460 ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics ,QB ,QB799 ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We report the discovery of J0624-6948, a low-surface brightness radio ring, lying between the Galactic Plane and the Large Magellanic Cloud (LMC). It was first detected at 888 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP), and with a diameter of ~196 arcsec. This source has phenomenological similarities to Odd Radio Circles (ORCs). Significant differences to the known ORCs - a flatter radio spectral index, the lack of a prominent central galaxy as a possible host, and larger apparent size - suggest that J0624-6948 may be a different type of object. We argue that the most plausible explanation for J0624-6948 is an intergalactic supernova remnant due to a star that resided in the LMC outskirts that had undergone a single-degenerate type Ia supernova, and we are seeing its remnant expand into a rarefied, intergalactic environment. We also examine if a massive star or a white dwarf binary ejected from either galaxy could be the supernova progenitor. Finally, we consider several other hypotheses for the nature of the object, including the jets of an active galactic nucleus (AGN) or the remnant of a nearby stellar super-flare., Comment: 20 pages accepted to MNRAS
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- 2022
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122. Speech recognition in the presence of speech maskers in children
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Jithin R. Balan, Qian-Jie Fu, John J. Galvin, and Srikanta K. Mishra
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Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) - Abstract
Listening to a target talker in the presence of other talkers follows a protracted developmental period. Such listening skills are critical for speech-language development and have clinical value. The purpose of the present study was to examine speech-in-speech recognition ability using digits in children. The major advantages of using digits are that it overcomes the biggest challenge of test administration, and digits are among the few first words children learn. Data were collected from 32 normal-hearing children (4–12 years) using full bandwidth speech materials. The test had four conditions like the Listening in Spatial Noise test. (1) Low cue: The target (male talker) and two male maskers were presented from the front. (2) Talker advantage: The target and two female maskers were presented from the front. (3) Spatial advantage: The target was presented from the front, and two male maskers were presented, one each from ±90°. (4) The target was presented from the front, and two female maskers were presented, one from ±90°. Results demonstrate developmental effects, good test-retest reliability, and feasibility of the computerized version of the test. Furthermore, results will be discussed in the context of various conditions and potential clinical applications.
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- 2023
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123. Benefits of long-term music training for segregation of competing speech by tonal language speakers
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Yang-wenyi Li, Xiaoting Cheng, Chenru Ding, John J. Galvin, Bing Chen, and Qian-Jie Fu
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Acoustics and Ultrasonics ,Arts and Humanities (miscellaneous) - Abstract
Extended experience with meaningful pitch information has been shown to benefit music perception as well as speech perception where pitch cues are important, such as segregation of competing speech and tonal language perception. Interestingly, pitch perception has been shown to be similar between non-musicians who speak a tonal language and musicians who speak a non-tonal language, both of which outperform non-musicians who speak a non-tonal language. However, it is unknown whether extensive music training can further benefit pitch perception in tonal language speakers. In this study, melodic contour identification, spectro-temporal pattern perception, and masked speech recognition was measured in 16 adult normal-hearing musicians and 16 non-musicians; all were Chinese native speakers of Mandarin. Melodic contour identification, spectro-temporal pattern perception, and masked speech recognition all were significantly better for musicians than for non-musicians. Compared to non-musicians, musicians better utilized talker sex cues to segregate competing speech; utilization of talker sex cues by musicians was associated with the onset and extent of music training. Across all participants, spectro-temporal pattern perception was associated with better masked speech understanding. The data suggest that early and extensive music training may further benefit tonal language speakers’ perception and utilization of pitch cues.
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- 2023
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124. Interactions between the Jet and Disk Wind in Nearby Radio-intermediate Quasar III Zw 2
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Ailing Wang, Tao An, Shaoguang Guo, Prashanth Mohan, Wara Chamani, Willem A. Baan, Talvikki Hovatta, Heino Falcke, Tim J. Galvin, Natasha Hurley-Walker, Sumit Jaiswal, Anne Lahteenmaki, Baoqiang Lao, Weijia Lv, Merja Tornikoski, Yingkang Zhang, CAS - Shanghai Astronomical Observatory, Metsähovi Radio Observatory, Netherlands Institute for Radio Astronomy, Radboud University Nijmegen, CSIRO, Curtin University, Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astronomy ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies - Abstract
Disk winds and jets are ubiquitous in active galactic nuclei (AGN), and how these two components interact remains an open question. We study the radio properties of a radio-intermediate quasar III Zw 2. We detect two jet knots J1 and J2 on parsec scales, which move at a mildly apparent superluminal speed of $1.35\,c$. Two $\gamma$-ray flares were detected in III Zw 2 in 2009--2010, corresponding to the primary radio flare in late 2009 and the secondary radio flare in early 2010. The primary 2009 flare was found to be associated with the ejection of J2. The secondary 2010 flare occurred at a distance of $\sim$0.3 parsec from the central engine, probably resulting from the collision of the jet with the accretion disk wind. The variability characteristics of III Zw 2 (periodic radio flares, unstable periodicity, multiple quasi-periodic signals and possible harmonic relations between them) can be explained by the global instabilities of the accretion disk. These instabilities originating from the outer part of the warped disk propagate inwards and can lead to modulation of the accretion rate and consequent jet ejection. At the same time, the wobbling of the outer disk may also lead to oscillations of the boundary between the disk wind and the jet tunnel, resulting in changes in the jet-wind collision site. III Zw 2 is one of the few cases observed with jet-wind interactions, and the study in this paper is of general interest for gaining insight into the dynamic processes in the nuclear regions of AGN., Comment: accepted by ApJ
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- 2023
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125. Sampling independent sets in the discrete torus.
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David J. Galvin
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- 2008
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126. Sharpness Overconstancy: the Roles of Visibility and Current Context.
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Sue J. Galvin, Abigail M. Squire, Diane S. Hailstone, and Robert P. O'Shea
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- 1997
127. Slow mixing of Glauber dynamics for the hard-core model on regular bipartite graphs.
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David J. Galvin and Prasad Tetali
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- 2006
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128. PSII-2 Daily patterns for respiration rates and internal temperatures of heat stressed lactating sows with or without electronically controlled cooling pads
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Jay S Johnson, Robert M Stwalley, Tyler C Field, Taylor L Jansen, Michaiah J Galvin, Jason R Graham, and Allan P Schinckel
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Poster Presentations ,Animal science ,Chemistry ,Respiration ,Genetics ,Animal Science and Zoology ,General Medicine ,Food Science - Abstract
Lactating sows are especially sensitive to heat stress (HS) due to high metabolic demands resulting from milk output. Therefore, there is a need to develop effective cooling technologies that reduce the impact of HS on lactating sows. The study objective was to determine whether electronically controlled cooling pads (ECP) would allow sows to remain euthermic under HS conditions. Twelve multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg) and litters (11.4 ± 0.7 piglets/litter) were assigned to either a non-functional ECP (NECP; n = 6) or an ECP (n = 6), housed in farrowing crates, and tested over two repetitions. Sows were provided feed and water ad libitum and all sows were exposed to HS (28.27 ± 1.42°C nighttime to 35.14 ± 0.70°C daytime). Body temperature (TB), was measured hourly using vaginal implants, and respiration rate (RR) was measured in 30 min intervals from 0600 to 2100 hrs over 2 d representing mid- and late lactation. Mixed model periodic regression equations were fitted to the TB and RR to time. The final model for TB included the effect of replicate, random effect of sow, day of lactation as a covariate, single-phase sine and cosine variables for each treatment and 2-phase sine and cosine periodic regression variables. The final model for RR included the random effect of sow, effect of treatment, replicate, day of lactation, sleeping, and single-phase sine and cosine functions for each treatment. An interaction (P < 0.05) between treatment and sine or cosine was observed for TB. For RR there was no interaction for treatment and cosine (P = 0.07), but an interaction (P < 0.05; -9.94) was observed for sine. The significant treatment by wavelength interactions observed indicate a change in RR and TB patterns when sows are placed on ECPs.
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- 2021
129. On Phase Transition in the Hard-Core Model on Math.
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David J. Galvin and Jeff Kahn 0001
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- 2004
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130. A Narrative Review on the Pathophysiology and Management for Radiation Cystitis
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C. Browne, N. F. Davis, E. Mac Craith, G. M. Lennon, D. W. Mulvin, D. M. Quinlan, Gerard P. Mc Vey, and D. J. Galvin
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Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Radiation cystitis is a recognised complication of pelvic radiotherapy. Incidence of radiation cystitis ranges from 23 to 80% and the incidence of severe haematuria ranges from 5 to 8%. High quality data on management strategies for radiation cystitis is sparse. Treatment modalities are subclassified into systemic therapies, intravesical therapies, and hyperbaric oxygen and interventional procedures. Short-term cure rates range from 76 to 95% for hyperbaric oxygen therapy and interventional procedures. Adverse effects of these treatment strategies are acceptable. Ultimately, most patients require multimodal treatment for curative purposes. Large randomised trials exploring emergent management strategies are required in order to strengthen evidence-based treatment strategies. Urologists encounter radiation cystitis commonly and should be familiar with diagnostic modalities and treatment strategies.
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- 2015
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131. Constraining the Nature of the 18 min Periodic Radio Transient GLEAM-X J162759.5-523504.3 via Multiwavelength Observations and Magneto-thermal Simulations
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N. Rea, F. Coti Zelati, C. Dehman, N. Hurley-Walker, D. de Martino, A. Bahramian, D. A. H. Buckley, J. Brink, A. Kawka, J. A. Pons, D. Viganò, V. Graber, M. Ronchi, C. Pardo Araujo, A. Borghese, E. Parent, T. J. Galvin, ESP, Universidad de Alicante. Departamento de Física Aplicada, Astrofísica Relativista, European Research Council, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Australian Research Council, and Universidad Autónoma de Barcelona
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,FOS: Physical sciences ,Astronomy and Astrophysics ,Galactic radio sources ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
We observed the periodic radio transient GLEAM-X J162759.5-523504.3 (GLEAM-X J1627) using the Chandra X-ray Observatory for about 30 ks on 2022 January 22–23, simultaneously with radio observations from the Murchison Widefield Array, MeerKAT, and the Australia Telescope Compact Array. Its radio emission and 18 min periodicity led the source to be tentatively interpreted as an extreme magnetar or a peculiar highly magnetic white dwarf. The source was not detected in the 0.3–8 keV energy range with a 3σ upper limit on the count rate of 3 × 10−4 counts s−1. No radio emission was detected during our X-ray observations either. Furthermore, we studied the field around GLEAM-X J1627 using archival European Southern Observatory and DECam Plane Survey data, as well as recent Southern African Large Telescope observations. Many sources are present close to the position of GLEAM-X J1627, but only two within the 2'' radio position uncertainty. Depending on the assumed spectral distribution, the upper limits converted to an X-ray luminosity of LX < 6.5 × 1029 erg s−1 for a blackbody with temperature kT = 0.3 keV, or LX < 9 × 1029 erg s−1 for a power law with photon index Γ = 2 (assuming a 1.3 kpc distance). Furthermore, we performed magneto-thermal simulations for neutron stars considering crust- and core-dominated field configurations. Based on our multiband limits, we conclude that (i) in the magnetar scenario, the X-ray upper limits suggest that GLEAM-X J1627 should be older than ∼1 Myr, unless it has a core-dominated magnetic field or has experienced fast cooling; (ii) in the white dwarf scenario, we can rule out most binary systems, a hot sub-dwarf, and a hot magnetic isolated white dwarf (T ≳ 10.000 K), while a cold isolated white dwarf is still compatible with our limits., N.R., F.C.Z., C.D., M.R., V.G., C.P., A.B., and E.P. are supported by the ERC Consolidator Grant "MAGNESIA" under grant agreement No. 817661, and National Spanish grant No. PGC2018-095512-BI00. F.C.Z., A.B., and V.G. are also supported by Juan de la Cierva Fellowships. C.D., M.R., and C.A.'s work has been carried out within the framework of the doctoral program in Physics of the Universitat Autónoma de Barcelona. N.H.W. is supported by an Australian Research Council Future Fellowship (project number FT190100231) funded by the Australian Government. D.d.M. acknowledges financial support from the Italian Space Agency (ASI) and National Institute for Astrophysics (INAF) under agreements ASI-INAF I/037/12/0 and ASI-INAF n.2017-14-H.0 and from INAF "Sostegno alla ricerca scientifica main streams dell'INAF," Presidential Decree 43/2018 and from INAF "SKA/CTA projects," Presidential Decree 70/2016. D.B. acknowledges support from the South African National Research Foundation. D.V. is supported by the ERC Starting Grant "IMAGINE" under grant agreement No. 948582. This work was also partially supported by the program Unidad de Excelencia Maria de Maetzu de Maeztu CEX2020-001058-M and by the PHAROS COST Action (grant No. CA16214).
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- 2022
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132. Low-frequency Radio Continuum Imaging and SED Modeling of 11 LIRGs: Radio-only and FUV to Radio Bands
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Subhrata Dey, Arti Goyal, Katarzyna Małek, Timothy J. Galvin, Nicholas Seymour, Tanio Díaz Santos, Julia Piotrowska, and Vassilis Charmandaris
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interstellar medium ,galaxy photometry ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,luminous infrared galaxies ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,spectral energy distribution ,radio continuum emission - Abstract
We present the detailed analysis of 11 local luminous infrared galaxies (LIRGs) from ultraviolet through far-infrared to radio ($\sim$70 MHz to $\sim$15 GHz) bands. We derive the astrophysical properties through spectral energy distribution (SED) modeling using the Code Investigating GALaxy Emission (CIGALE) and UltraNest codes. The radio SEDs include our new observations at 325 and 610 MHz from the GMRT and the measurements from public archives. Our main results are (1) radio SEDs show turnovers and bends, (2) the synchrotron spectral index of the fitted radio spectra ranges between $-$0.5 and $-$1.7, and (3) the infrared luminosity, dust mass, dust temperature, stellar mass, star-formation rates (SFRs) and AGN fraction obtained from CIGALE falls in the range exhibited by galaxies of the same class. The ratio of 60$\mu$m infrared and 1.4 GHz radio luminosity, the 1.4 GHz thermal fraction, and emission measure range between 2.1 and 2.9, 0.1% and 10%, 0.02 and 269.5$\times$10$^{6}$ cm$^{-6}$ pc, respectively. We conclude that the turnovers seen in the radio SEDs are due to free-free absorption; this is supported by the low AGN fraction derived from the CIGALE analysis. The decomposed 1.4 GHz thermal and nonthermal radio luminosities allowed us to compute the star formation rate (SFR) using scaling relations. A positive correlation is observed between the SFR$_{IR}$ obtained 10 Myr ago (compared to 100 Myr ago) and 1.4 GHz radio (total and nonthermal) because similar synchrotron lifetimes are expected for typical magnetic field strengths observed in these galaxies ($\approx$50$\mu$G)., Comment: ApJ accepted. Comments are welcome
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- 2022
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133. Princeton Studies in American Politics: Dwight D. Eisenhower to George W. Bush
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Daniel J. Galvin
- Published
- 2009
134. Segregation of competing speech in adults and children with normal hearing and in children with cochlear implants
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Ji-Sheng Liu, Qian-Jie Fu, Duo-Duo Tao, Ya-Feng Yu, John J. Galvin, and Yang-Wenyi Liu
- Subjects
Masking (art) ,Adult ,Male ,medicine.medical_specialty ,Speech perception ,Acoustics and Ultrasonics ,business.industry ,Perceptual Masking ,Audiology ,Cochlear Implants ,Arts and Humanities (miscellaneous) ,Hearing ,otorhinolaryngologic diseases ,Speech Perception ,Medicine ,Humans ,Speech ,Female ,Speech reception ,Association (psychology) ,business ,Child ,psychological phenomena and processes - Abstract
Children with normal hearing (CNH) have greater difficulty segregating competing speech than do adults with normal hearing (ANH). Children with cochlear implants (CCI) have greater difficulty segregating competing speech than do CNH. In the present study, speech reception thresholds (SRTs) in competing speech were measured in Chinese Mandarin-speaking ANH, CNH, and CCIs. Target sentences were produced by a male Mandarin-speaking talker. Maskers were time-forward or -reversed sentences produced by a native Mandarin-speaking male (different from the target) or female or a non-native English-speaking male. The SRTs were lowest (best) for the ANH group, followed by the CNH and CCI groups. The masking release (MR) was comparable between the ANH and CNH group, but much poorer in the CCI group. The temporal properties differed between the native and non-native maskers and between forward and reversed speech. The temporal properties of the maskers were significantly associated with the SRTs for the CCI and CNH groups but not for the ANH group. Whereas the temporal properties of the maskers were significantly associated with the MR for all three groups, the association was stronger for the CCI and CNH groups than for the ANH group.
- Published
- 2021
135. Speech understanding in diffuse steady noise in typically hearing and hard of hearing listeners
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Julie Bestel, Elsa Legris, Frédéric Rembaud, Thierry Mom, and John J. Galvin
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Adult ,Multidisciplinary ,Hearing ,Speech Perception ,Humans ,Speech ,Hearing Loss ,Noise - Abstract
Spatial cues can facilitate segregation of target speech from maskers. However, in clinical practice, masked speech understanding is most often evaluated using co-located speech and maskers (i.e., without spatial cues). Many hearing aid centers in France are equipped with five-loudspeaker arrays, allowing masked speech understanding to be measured with spatial cues. It is unclear how hearing status may affect utilization of spatial cues to segregate speech and noise. In this study, speech reception thresholds (SRTs) for target speech in “diffuse noise” (target speech from 1 speaker, noise from the remaining 4 speakers) in 297 adult listeners across 9 Audilab hearing centers. Participants were categorized according to pure-tone-average (PTA) thresholds: typically-hearing (TH; ≤ 20 dB HL), mild hearing loss (Mild; >20 ≤ 40 dB HL), moderate hearing loss 1 (Mod-1; >40 ≤ 55 dB HL), and moderate hearing loss 2 (Mod-2; >55 ≤ 65 dB HL). All participants were tested without aided hearing. SRTs in diffuse noise were significantly correlated with PTA thresholds, age at testing, as well as word and phoneme recognition scores in quiet. Stepwise linear regression analysis showed that SRTs in diffuse noise were significantly predicted by a combination of PTA threshold and word recognition scores in quiet. SRTs were also measured in co-located and diffuse noise in 65 additional participants. SRTs were significantly lower in diffuse noise than in co-located noise only for the TH and Mild groups; masking release with diffuse noise (relative to co-located noise) was significant only for the TH group. The results are consistent with previous studies that found that hard of hearing listeners have greater difficulty using spatial cues to segregate competing speech. The data suggest that speech understanding in diffuse noise provides additional insight into difficulties that hard of hearing individuals experience in complex listening environments.
- Published
- 2021
136. A radio transient with unusually slow periodic emission
- Author
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N, Hurley-Walker, X, Zhang, A, Bahramian, S J, McSweeney, T N, O'Doherty, P J, Hancock, J S, Morgan, G E, Anderson, G H, Heald, and T J, Galvin
- Abstract
The high-frequency radio sky is bursting with synchrotron transients from massive stellar explosions and accretion events, but the low-frequency radio sky has, so far, been quiet beyond the Galactic pulsar population and the long-term scintillation of active galactic nuclei. The low-frequency band, however, is sensitive to exotic coherent and polarized radio-emission processes, such as electron-cyclotron maser emission from flaring M dwarfs
- Published
- 2021
137. Radio Continuum Sources behind the Large Magellanic Cloud
- Author
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Tim J. Galvin, Thomas G. Pannuti, Jordan D. Collier, Corrado Trigilio, A. Ingallinera, G. Umana, Jeffrey L Payne, J. Marvil, Evan J Crawford, Lister Staveley-Smith, Ivan S. Bojičić, Kevin Grieve, Craig S. Anderson, Miroslav Filipovic, B. S. Koribalski, Misao Sasaki, D. A. Leahy, Ray P. Norris, Devika Shobhana, Natasha Hurley-Walker, Nicholas F. H Tothill, Simone Riggi, Gavin Rowell, Heinz Andernach, R. Z. E. Alsaberi, Roland Kothes, Clara M. Pennock, P. Maggi, Bi-Qing For, Frank Haberl, Chandreyee Maitra, Isabella Prandoni, Laurence A. F. Park, Hidetoshi Sano, Lawrence Rudnick, Eleni Vardoulaki, Andrew M. Hopkins, H. Leverenz, J. Th. van Loon, Dejan Urošević, Patrick J. Kavanagh, Observatoire astronomique de Strasbourg (ObAS), and Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Infrared ,galaxies: active ,Population ,radio continuum: general ,FOS: Physical sciences ,Astrophysics ,01 natural sciences ,0103 physical sciences ,Magellanic Clouds ,QD ,Continuum (set theory) ,education ,Large Magellanic Cloud ,010303 astronomy & astrophysics ,catalogues ,QC ,QB ,Physics ,education.field_of_study ,Spectral index ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Alpha (navigation) ,Astrophysics - Astrophysics of Galaxies ,Redshift ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Radio frequency ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a comprehensive multi-frequency catalogue of radio sources behind the Large Magellanic Cloud between 0.2 and 20 GHz, gathered from a combination of new and legacy radio continuum surveys. This catalogue covers an area of $\sim$144~deg$^2$ at angular resolutions from 45 arcsec to $\sim$3 arcmin. We find 6434 discrete radio sources in total, of which 3789 are detected at two or more radio frequencies. We estimate the median spectral index ($\alpha$; where $S_{v}\sim\nu^\alpha$) of $\alpha = -0.89 $ and mean of $-0.88 \pm 0.48$ for 3636 sources detected exclusively at two frequencies (0.843 and 1.384 GHz) with similar resolution (FWHM $\sim$40-45 arcsec). The large frequency range of the surveys makes it an effective tool to investigate Gigahertz Peak Spectrum (GPS), Compact Steep Spectrum (CSS) and Infrared Faint Radio sources populations within our sample. We find 10 GPS candidates with peak frequencies near 5 GHz, from which we estimate their linear size. 1866 sources from our catalogue are (CSS) candidates with $\alpha 0.5$. We found optical counterparts for 343 of the radio continuum sources, of which 128have a redshift measurement. Finally, we investigate the population of 123 Infrared Faint Radio Sources (IFRSs) found in this study., Comment: Accepted for publication in MNRAS
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- 2021
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138. Vocal emotion recognition with cochlear implants.
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Xin Luo 0002, Qian-Jie Fu, and John J. Galvin III
- Published
- 2006
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139. Science and Business of Medicinal Chemistry: A 'Bench-to-Bedside' Course for Nonmajors
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Steven Casper, Cooper J. Galvin, Grace E. Beck, and Anna G. Wenzel
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Science instruction ,Class (computer programming) ,Scientific literacy ,business.industry ,Public policy ,General Chemistry ,business ,Commercialization ,Medicinal chemistry ,Curriculum ,Bench to bedside ,Education ,Pharmaceutical industry - Abstract
“The Science and Business of Medicinal Chemistry” was developed to provide nonscience majors with an in-depth perspective into the pharmaceutical industry. As a lecture course with a laboratory component, topics discussed include an introduction to the basic concepts of medicinal chemistry, such as drug discovery, development, and commercialization; a discussion of chemical bonding and the organic functional groups found in drug molecules; and an examination of the physiochemical properties related to drug action. Student scientific literacy of the public policy debates surrounding the pharmaceutical industry and the commercialization of science was enhanced through class discussions and group-based projects. The details of this course, its implementation, and assessment are discussed.
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- 2019
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140. Radio observations of supernova remnant G1.9+0.3
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Quentin Roper, Michael G. Burton, Ain De Horta, Kieran J. Luken, Gavin Rowell, T. J. Galvin, Nicholas O Ralph, Natasha Hurley-Walker, Miroslav Filipovic, Graeme F Wong, Ray P. Norris, Denis Leahy, Lisa Harvey-Smith, N. Maxted, Dejan Urošević, I. Sushch, Catherine Braiding, Rebecca Blackwell, Roland Kothes, James R. Allison, and Robert Brose
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Expansion rate ,FOS: Physical sciences ,ISM [radio continuum] ,Astrophysics ,01 natural sciences ,Radio spectrum ,law.invention ,Telescope ,supernovae: general ,law ,0103 physical sciences ,ISM: individual objects: G1.9+0.3 ,Supernova remnant ,010303 astronomy & astrophysics ,ISM: supernova remnants ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,individual objects: G1.9+0.3 [ISM] ,Spectral index ,010308 nuclear & particles physics ,supernova remnants [ISM] ,Astronomy and Astrophysics ,Continuum flux ,Astrophysics - Astrophysics of Galaxies ,radio continuum: ISM ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,ddc:520 ,Astrophysics - High Energy Astrophysical Phenomena ,general [supernovae] - Abstract
Monthly notices of the Royal Astronomical Society 492(2), 2606 - 2621 (2020). doi:10.1093/mnras/stz3439, We present 1–10 GHz radio continuum flux density, spectral index, polarization, and rotation measure (RM) images of the youngest known Galactic supernova remnant (SNR) G1.9+0.3, using observations from the Australia Telescope Compact Array. We have conducted an expansion study spanning eight epochs between 1984 and 2017, yielding results consistent with previous expansion studies of G1.9+0.3. We find a mean radio continuum expansion rate of (0.78 ± 0.09) per cent yr$^{−1}$ (or ∼8900 km s$^{−1}$ at an assumed distance of 8.5 kpc), although the expansion rate varies across the SNR perimetre. In the case of the most recent epoch between 2016 and 2017, we observe faster-than-expected expansion of the northern region. We find a global spectral index for G1.9+0.3 of −0.81 ± 0.02 (76 MHz–10 GHz). Towards the northern region, however, the radio spectrum is observed to steepen significantly (∼−1). Towards the two so-called (east and west) ‘ears’ of G1.9+0.3, we find very different RM values of 400–600 and 100–200 rad m$^2$, respectively. The fractional polarization of the radio continuum emission reaches (19 ± 2) per cent, consistent with other, slightly older, SNRs such as Cas A., Published by Oxford Univ. Press, Oxford
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- 2019
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141. Réponses auditives corticales en fonction du système de réhabilitation auditive chez des patients atteints d’une surdité unilatérale
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Sylvie Roux, J.-M. Aoustin, David Bakhos, E. Legris, John J. Galvin, and université François-Rabelais de Tours
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[SPI]Engineering Sciences [physics] ,03 medical and health sciences ,0302 clinical medicine ,Otorhinolaryngology ,Surgery ,030223 otorhinolaryngology ,16. Peace & justice ,ComputingMilieux_MISCELLANEOUS ,030217 neurology & neurosurgery - Abstract
Resume Objectif Evaluer l’impact des systemes de rehabilitation auditive dans le cadre d’une surdite unilaterale (contralateral routing of signal [CROS], BAHA ou bone-anchored hearing aid [BAHA] et implant cochleaire [IC]) par l’intermediaire des reponses auditives corticales et des performances auditives. Sujets et methode Vingt et un adultes presentant une surdite unilaterale rehabilites par un CROS (n = 6), BAHA (n = 6) et IC (n = 9) ont ete inclus. Sept sujets normo-entendants ont servi de groupe controle. Il a ete effectue l’etude des potentiels evoques auditifs corticaux (PEAC) suite a une stimulation auditive (/ba/) avec et sans leur rehabilitation auditive. L’amplitude et la latence des differentes ondes relevees sur le global field power (GFP) ont ete analysees ainsi que les cartographies de champ de potentiels. Les mesures comportementales (reconnaissance de phrases dans le bruit avec et sans indices spatiaux) ont ete collectees. Resultats Seul l’IC induit un changement d’amplitude pour le pic de l’onde N1 (p Conclusion L’IC presente un impact plus important sur la morphologie des PEAC et les performances auditives. Une etude longitudinale permettrait d’analyser l’evolution de la reorganisation corticale.
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- 2019
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142. The ATLAS 9.0 GHz survey of the extended Chandra Deep Field South: the faint 9.0 GHz radio population
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Nick Seymour, Timothy J Galvin, Minh Huynh, and Ray P. Norris
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Radio galaxy ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,law.invention ,Telescope ,law ,0103 physical sciences ,Source counts ,education ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,education.field_of_study ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Alpha (navigation) ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Square degree ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Chandra Deep Field South - Abstract
We present a new image of the 9.0 GHz radio emission from the extended Chandra Deep Field South. A total of 181 hours of integration with the Australia Telescope Compact Array has resulted in a 0.276 square degree image with a median sensitivity of $\sim$20 $\mu$Jy/beam rms, for a synthesised beam of 4.0 $\times$ 1.3 arcsec. We present a catalogue of the 9.0 GHz radio sources, identifying 70 source components and 55 individual radio galaxies. Source counts derived from this sample are consistent with those reported in the literature. The observed source counts are also generally consistent with the source counts from simulations of the faint radio population. Using the wealth of multiwavelength data available for this region, we classify the faint 9 GHz population and find that 91% are radio loud AGN, 7% are radio quiet AGN and 2% are star forming galaxies. The 9.0 GHz radio sources were matched to 5.5 and 1.4 GHz sources in the literature and we find a significant fraction of flat or inverted spectrum sources, with 36% of the 9 GHz sources having $\alpha_{5.5GHz}^{9.0GHz}$ $>$ -0.3 (for $S \propto \nu^\alpha$). This flat or inverted population is not well reproduced by current simulations of radio source populations., Comment: 17 pages, 12 figures. Accepted for publication in MNRAS
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- 2019
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143. Let’s not conflate APD with political history, and other reflections on 'Causal Inference and American Political Development'
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Daniel J. Galvin
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Economics and Econometrics ,Sociology and Political Science ,05 social sciences ,Conflation ,0506 political science ,Epistemology ,Politics ,Politics of the United States ,Pluralism (political theory) ,Causal inference ,0502 economics and business ,Political history ,050602 political science & public administration ,Comparative historical research ,050207 economics ,Public finance - Abstract
American political development (APD) is a distinctive field of research that should not be conflated with, or flattened into a caricature of, historical research that uses historical data to make flawed causal inferences. It is a problem-driven inquiry into the dynamics of American politics, a substantive and theoretical exploration of how American politics has changed over time. APD research uses diverse types of data from a wide range of sources and employs multiple methodologies and analytical approaches, as appropriate. Because APD is a substantive and theoretical inquiry and not a method per se, there is no a priori reason to think that design-based causal inference cannot play a valuable role in studies of America’s political development, just as advanced quantitative methods have. However, while APD research does often seek to explain outcomes and establish causal relationships, that is not its only goal, and its orientation toward causality, causes, and theory tends to differ from much of the work in the causal inference tradition. This essay endeavors to clear up some of the confusion by offering the author’s perspective on what APD does well and how it does it. It also suggests how experimental research and APD research might be brought into more fruitful intellectual exchange and concludes with some thoughts on the value of methodological and intellectual pluralism.
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- 2019
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144. From Labor Law to Employment Law: The Changing Politics of Workers’ Rights
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Daniel J. Galvin
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History ,Politics ,Empirical data ,Sociology and Political Science ,State (polity) ,media_common.quotation_subject ,Political science ,Labour law ,Political economy ,Collective action ,Substantive rights ,media_common - Abstract
Over the past several decades, a new kind of labor politics has emerged in new venues (state and local levels), focusing on new governing institutions (employment laws), involving new strategies by labor unions, and featuring new organizational forms (“alt-labor”). The timing, form, and content of these developments have been powerfully shaped by the persistence of the increasingly outmoded but still authoritative national labor law, which has constrained and channeled the efforts of workers and their advocates to respond to growing problems. While the new institutions and organizations provide new substantive rights for workers and alternative vehicles for voice and collective action, the layering of these new forms alongside the old—without displacing the latter—has generated new problems without solving the problems produced by the ossification of labor law in the first place. Using novel empirical data and analysis, this article documents these changes, explores their causes, and considers their consequences for the changing politics of workers’ rights.
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- 2019
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145. Effects of tonotopic matching and spatial cues on segregation of competing speech in simulations of bilateral cochlear implants
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Mathew Thomas, Shelby Willis, John J. Galvin, and Qian-Jie Fu
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Male ,Cochlear Implants ,Multidisciplinary ,Speech Perception ,Humans ,Speech ,Cues ,Cochlear Implantation - Abstract
In the clinical fitting of cochlear implants (CIs), the lowest input acoustic frequency is typically much lower than the characteristic frequency associated with the most apical electrode position, due to the limited electrode insertion depth. For bilateral CI users, electrode positions may differ across ears. However, the same acoustic-to-electrode frequency allocation table (FAT) is typically assigned to both ears. As such, bilateral CI users may experience both intra-aural frequency mismatch within each ear and inter-aural mismatch across ears. This inter-aural mismatch may limit the ability of bilateral CI users to take advantage of spatial cues when attempting to segregate competing speech. Adjusting the FAT to tonotopically match the electrode position in each ear (i.e., increasing the low acoustic input frequency) is theorized to reduce this inter-aural mismatch. Unfortunately, this approach may also introduce the loss of acoustic information below the modified input acoustic frequency. The present study explored the trade-off between reduced inter-aural frequency mismatch and low-frequency information loss for segregation of competing speech. Normal-hearing participants were tested while listening to acoustic simulations of bilateral CIs. Speech reception thresholds (SRTs) were measured for target sentences produced by a male talker in the presence of two different male talkers. Masker speech was either co-located with or spatially separated from the target speech. The bilateral CI simulations were produced by 16-channel sinewave vocoders; the simulated insertion depth was fixed in one ear and varied in the other ear, resulting in an inter-aural mismatch of 0, 2, or 6 mm in terms of cochlear place. Two FAT conditions were compared: 1) clinical (200–8000 Hz in both ears), or 2) matched to the simulated insertion depth in each ear. Results showed that SRTs were significantly lower with the matched than with the clinical FAT, regardless of the insertion depth or spatial configuration of the masker speech. The largest improvement in SRTs with the matched FAT was observed when the inter-aural mismatch was largest (6 mm). These results suggest that minimizing inter-aural mismatch with tonotopically matched FATs may benefit bilateral CI users’ ability to segregate competing speech despite substantial low-frequency information loss in ears with shallow insertion depths.
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- 2022
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146. Mandarin speech perception in combined electric and acoustic stimulation.
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Yongxin Li, Guoping Zhang, John J Galvin, and Qian-Jie Fu
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Medicine ,Science - Abstract
For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI) and hearing aid (HA) typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0) information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2) information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects' HA-aided pure-tone average (PTA) thresholds between 250 and 2000 Hz; subjects were divided into two groups: "better" PTA (50 dB HL). The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12), further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception.
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- 2014
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147. Single- and multi-channel modulation detection in cochlear implant users.
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John J Galvin, Sandy Oba, Qian-Jie Fu, and Deniz Başkent
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Medicine ,Science - Abstract
Single-channel modulation detection thresholds (MDTs) have been shown to predict cochlear implant (CI) users' speech performance. However, little is known about multi-channel modulation sensitivity. Two factors likely contribute to multichannel modulation sensitivity: multichannel loudness summation and the across-site variance in single-channel MDTs. In this study, single- and multi-channel MDTs were measured in 9 CI users at relatively low and high presentation levels and modulation frequencies. Single-channel MDTs were measured at widely spaced electrode locations, and these same channels were used for the multichannel stimuli. Multichannel MDTs were measured twice, with and without adjustment for multichannel loudness summation (i.e., at the same loudness as for the single-channel MDTs or louder). Results showed that the effect of presentation level and modulation frequency were similar for single- and multi-channel MDTs. Multichannel MDTs were significantly poorer than single-channel MDTs when the current levels of the multichannel stimuli were reduced to match the loudness of the single-channel stimuli. This suggests that, at equal loudness, single-channel measures may over-estimate CI users' multichannel modulation sensitivity. At equal loudness, there was no significant correlation between the amount of multichannel loudness summation and the deficit in multichannel MDTs, relative to the average single-channel MDT. With no loudness compensation, multichannel MDTs were significantly better than the best single-channel MDT. The across-site variance in single-channel MDTs varied substantially across subjects. However, the across-site variance was not correlated with the multichannel advantage over the best single channel. This suggests that CI listeners combined envelope information across channels instead of attending to the best channel.
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- 2014
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148. From Document Delivery to Information Access: Convergence at the National Level
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Thomas J. Galvin
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- 2021
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149. Combinatorially interpreting generalized Stirling numbers.
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John Engbers, David J. Galvin, and Justin Hilyard
- Published
- 2013
150. Revisiting the Giant Radio Galaxy ESO 422-G028: Part I. Discovery of a neutral inflow and recent star formation in a restarted giant
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C. J. Riseley, Henry R. M. Zovaro, Nicole P. H. Nesvadba, Tim J. Galvin, Philip Taylor, U. Malik, and Lisa J. Kewley
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Physics ,Jet (fluid) ,Stellar population ,010308 nuclear & particles physics ,Star formation ,Radio galaxy ,Stellar rotation ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Accretion (astrophysics) ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Absorption (logic) ,010303 astronomy & astrophysics - Abstract
Giant radio galaxies provide important clues into the life cycles and triggering mechanisms of radio jets. With large-scale jets spanning 1.8 Mpc, ESO 422-G028 ($z = 0.038$) is a giant radio galaxy that also exhibits signs of restarted jet activity in the form of pc-scale jets. We present a study of the spatially-resolved stellar and gas properties of ESO 422-G028 using optical integral field spectroscopy from the WiFeS spectrograph. In addition to the majority $\sim 13\,\rm Gyr$ old stellar population, ESO 422-G028 exhibits a much younger ($\lesssim 10\,\rm Myr$ old) component with an estimated mass of $ 10^{7.6}\,\rm M_\odot$ which is predominantly located in the North-West region of the galaxy. Unusually, the ionised gas kinematics reveal two distinct disks traced by narrow ($\sigma_{\rm H\alpha} < 100 \,\rm km\,s^{-1}$) and broad ($\sigma_{\rm H\alpha} > 150 \,\rm km\,s^{-1}$) H$\alpha$ emission respectively. Both ionised gas disks are misaligned with the axis of stellar rotation, suggesting an external origin. This is consistent with the prominent interstellar Na D absorption, which traces a $1 - 3 \,\rm M_\odot \, yr^{-1}$ inflow of neutral gas from the North. We posit that an inflow of gas - either from an accretion event or a gas-rich merger - has triggered both the starburst and the restarted jet activity, and that ESO 422-G028 is potentially on the brink of an epoch of powerful AGN activity., Comment: 21 pages, 19 figures; submitted to the Monthly Notices of the Royal Astronomical Society
- Published
- 2021
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