2,399 research outputs found

    Variation of Molecular Line Ratios and Cloud Properties in the Arp 299 Galaxy Merger

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    High resolution observations of 12CO (2.''3), 13CO (3.''9), and HCN (5.''4) J=1--0 in the galaxy merger Arp 299 (IC 694 and NGC 3690) show the line ratios vary dramatically across the system. The 12CO/13CO ratio is unusually large, 60 +- 15, at the IC 694 nucleus, where 12CO emission is very strong, and much smaller, 10 +- 3, in the southern extended disk of that galaxy. Elsewhere, the 12CO/13CO line ratio is 5-20, typical of spiral galaxies. The line ratio variation in the overlap between the two galaxies is smaller, ranging from 10 +- 3 in the east to 20 +- 4 in the west. The 12CO/HCN line ratio also varies across Arp 299, although to a lesser degree. HCN emission is bright towards each galaxy nucleus and in the extranuclear region of active star formation; it was not detected in the IC 694 disk, or the eastern part of the overlap region, leading to lower limits of 25 and 20 respectively. By contrast, at the nuclei of IC 694 and NGC 3690 the ratios are 9 +- 1 and 14 +- 3 respectively. In the western part of the overlap region it is 11 +- 3.Comment: 16 pages, 4 postscript figures, to appear in ApJ Letter

    Safety in the workplace and the role of the internal communicator

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    This paper describes the role of the internal communicator in the promotion of safety in the workplace and provides recommendations for effective communication strategies in this area. The authors conducted structured interviews with internal communicators and environmental, health, and safety professionals working in large corporations in the United States. Using a grounded theory methodology, common themes were identified and practical recommendations for internal communicators were generated. The analysis of the interview data yielded five themes which describe an appropriate role of the internal communicator with respect to safety communication: (a) engagement with safety personnel, (b) engagement with management, (c) engagement with workers, (d) the need for collaboration, and (e) the value of traditional communication technologies

    Increasing the susceptibility of the rat 208F fibroblast cell line to radiation-induced apoptosis does not alter its clonogenic survival dose-response.

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    Recent studies have suggested a correlation between the rate and incidence of apoptosis and the radiation response of particular cell lines. However, we found that increasing the rate of induction of apoptosis in the fibroblast line 208F, by transfecting it with human c-myc, did not lead to a change in its clonogenic survival dose-response for either gamma-irradiation or 125I-induced DNA damage. It was also found that expression of mutant (T24) Ha-ras in the 208F line appeared to decrease the level of apoptosis per mitosis after irradiation and inhibited the formation of nucleosomal ladders, but did not affect either the onset of the morphological features of apoptosis or the clonogenic survival dose-response of the cells to either gamma-irradiation or 125I-induced DNA damage. Our findings suggest that it may be incorrect to make predictions about the radiosensitivity of cells based only on knowledge of their mode of death

    New determinations of gamma-ray line intensities of the Ep = 550 keV and Ep = 1747 keV resonances of the 13-C(p,gamma)14-N reaction

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    Gamma-ray angular distributions for the resonances at Ep = 550 keV and 1747 keV of the radiative capture reaction 13-C(p,g)14-N have been measured, using intense proton beams on isotopically pure 13-C targets. Relative intensities for the strongest transitions were extracted with an accuracy of typically five per cent, making these resonances new useful gamma-ray standards for efficiency calibration in the energy range Egamma = 1.6 to 9 MeV.Comment: 17 pages, 6 figures, Nuclear Instruments and Methods, Sec. A, accepte

    Describing return to work after stroke : a feasibility trial of 12-month outcomes

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    Objective: Stroke is the greatest cause of disability in adults. A quarter of strokes in the UK affect people of working age, yet under half of them return to work after stroke. There has been little investigation into what constitutes “return to work” following stroke. The aim of this study is to describe the work metrics of stroke survivor participants in a feasibility randomized controlled trial of an early stroke specific vocational rehabilitation intervention. Methods: Retrospective analysis of trial data. Metrics on work status, working hours, workplace accommodations and costs were extracted from trial out - comes gathered by postal questionnaire at 3, 6, and 12 months’ post-randomization for 46 stroke participants in a feasibility randomized controlled trial. Participants were randomized to receive vocational rehabilitation (intervention) or usual care (control). Results: Two-thirds ( n = 29; 63%) of participants re - turned to work at some point in the 12 months following stroke. Participants took a mean of 90 days to return to work. Most returned to the same role with an existing employer. Only one-third of participants who were employed full-time at stroke onset were working full-time at 12 months post-stroke. Most participants experienced a reduction in pre-stroke earnings. Workplace accommodations were more common among intervention group participants. More intervention participants than control participants reported satisfaction with work at both 6 and 12 months post-randomization. Conclusion: This study illustrates the heterogeneous nature of return to work and the dramatic impact of stroke on work status, working hours and income. Longitudinal research should explore the socioeconomic legacy of stroke and include clear definitions of work and accurate measures of working hours and income from all sources

    Factorizable ribbon quantum groups in logarithmic conformal field theories

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    We review the properties of quantum groups occurring as Kazhdan--Lusztig dual to logarithmic conformal field theory models. These quantum groups at even roots of unity are not quasitriangular but are factorizable and have a ribbon structure; the modular group representation on their center coincides with the representation on generalized characters of the chiral algebra in logarithmic conformal field models.Comment: 27pp., amsart++, xy. v2: references added, some other minor addition

    Exposure of benthic invertebrates to sediment vibration: From laboratory experiments to outdoor simulated pile-driving

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    This is the final version of the article. Available from Acoustical Society of America via the DOI in this record.Fourth International Conference on the Effects of Noise on Aquatic Life, Dublin, Ireland, 10-16 July 2016Activities directly interacting with the seabed, such as pile-driving, can produce vibrations that have the potential to impact benthic invertebrates within their vicinity. This stimuli may interfere with crucial behaviors such as foraging and predator avoidance, and the sensitivity to vibration is largely unknown. Here, the responsiveness of benthic invertebrates to sediment vibration is discussed in relation to laboratory and semi-field trials with two marine species: the mussel (Mytilus edulis) and hermit crab (Pagurus bernhardus). Sensory threshold curves were produced for both species in controlled laboratory conditions, followed by small-scale pile-driving exposures in the field. The merits of behavioral indicators are discussed, in addition to using physiological measures, as a method of determining reception and measuring responses. The measurement and sensors required for sediment vibration quantification are also discussed. Response and threshold data were related to measurements taken in the vicinity of anthropogenic sources, allowing a link between responsiveness and actual operations. The impact of pile-driving on sediment-dwelling invertebrates has received relatively little research, yet the data here suggest that such activities are likely to impact key coastal species which play important roles within the marine environment.LR would like to thank the organizers and sponsors of the 2016 conference for supporting her attendance for which she is extremely grateful. This study was partially funded by a research award from the Malacological Society of London to LR. The authors would also like to acknowledge Defra and NERC who funded the laboratory and field work aspects respectively, and the staff at the OREC field site, Blyth

    Library technician course recognition: meeting the challenge of a distributed national education program

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    This paper looks at the challenges presented for the Australian Library and Information Association by its role as the professional association responsible for ensuring the quality of Australian library technician graduates. There is a particular focus on the issue of course recognition, where the Association?s role is complicated by the need to work alongside the national quality assurance processes that have been established by the relevant technical education authorities. The paper describes the history of course recognition in Australia; examines the relationship between course recognition and other quality measures; and describes the process the Association has undertaken recently to ensure appropriate professional scrutiny in a changing environment of accountability

    Calling by Concluding Sentinels: Coordinating Cooperation or Revealing Risk?

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    Efficient cooperation requires effective coordination of individual contributions to the cooperative behaviour. Most social birds and mammals involved in cooperation produce a range of vocalisations, which may be important in regulating both individual contributions and the combined group effort. Here we investigate the role of a specific call in regulating cooperative sentinel behaviour in pied babblers (Turdoides bicolor). ‘Fast-rate chuck’ calls are often given by sentinels as they finish guard bouts and may potentially coordinate the rotation of individuals as sentinels, minimising time without a sentinel, or may signal the presence or absence of predators, regulating the onset of the subsequent sentinel bout. We ask (i) when fast-rate chuck calls are given and (ii) what effect they have on the interval between sentinel bouts. Contrary to expectation, we find little evidence that these calls are involved in regulating the pied babbler sentinel system: observations revealed that their utterance is influenced only marginally by wind conditions and not at all by habitat, while observations and experimental playback showed that the giving of these calls has no effect on inter-bout interval. We conclude that pied babblers do not seem to call at the end of a sentinel bout to maximise the efficiency of this cooperative act, but may use vocalisations at this stage to influence more individually driven behaviours
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