13,528 research outputs found

    Competition between noise and coupling in the induction of synchronisation.

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    We apply a Fokker-Planck analysis to investigate the relative influences of coupling strength and noise on the synchronisation of two phase oscillators. We go beyond earlier studies of noise-induced synchronisation (without couplings) and coupling-induced synchronisation (without common noise) to consider both effects together, and we obtain a result that is very different from a straightforward superposition of the effects of each agent acting alone: two regimes are possible depending on which agent is inducing the synchronisation. In each regime, one agent induces and the other hinders the synchronisation. In particular we show that, counterintuitively, coupling can sometimes inhibit synchronisation

    Identification of red supergiants in nearby galaxies with mid-IR photometry

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    The role of episodic mass loss in massive star evolution is one of the most important open questions of current stellar evolution theory. Episodic mass loss produces dust and therefore causes evolved massive stars to be very luminous in the mid-infrared and dim at optical wavelengths. We aim to increase the number of investigated luminous mid-IR sources to shed light on the late stages of these objects. To achieve this we employed mid-IR selection criteria to identity dusty evolved massive stars in two nearby galaxies. The method is based on mid-IR colors, using 3.6 {\mu}m and 4.5 {\mu}m photometry from archival Spitzer Space Telescope images of nearby galaxies and J-band photometry from 2MASS. We applied our criteria to two nearby star-forming dwarf irregular galaxies, Sextans A and IC 1613, selecting eight targets, which we followed up with spectroscopy. Our spectral classification and analysis yielded the discovery of two M-type supergiants in IC 1613, three K-type supergiants and one candidate F-type giant in Sextans A, and two foreground M giants. We show that the proposed criteria provide an independent way for identifying dusty evolved massive stars, that can be extended to all nearby galaxies with available Spitzer/IRAC images at 3.6 {\mu}m and 4.5 {\mu}m.Comment: 8 pages, 4 figures, A&A in pres

    “After all the time I put into this”: co-creation and the end-of-life of social network games

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    User engagement in processes of co-design and co-creation are common practices in Social Network Games (SNGs). Though the interdependency between producer and user is of mutual benefit throughout much of the lifetime of an SNG, there are critical moments where this relationship becomes problematic. We adopt an ethnographic approach, covering the entire three year lifespan of a well-known SNG, with a focus on the ‘end of life’ experience from players’ perspectives. Our results show that, at the game’s discontinuation announcement, players reflect strongly on the value that they associate with their gameplay and its involvement. We suggest that the notion of players as co-creators may be undervalued by companies during strategic decision-making especially since at discontinuation players are left without ownership of their co-created product. This deeper understanding of players as co-creators serves as case study for developers building social games both on and off social networking platforms

    Long-Term Safety of Tedizolid in a Patient With Spondilodiscitis After Switch From Linezolid Due to Toxicity

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    The patient is a 57-year-old man with liver cirrhosis, Bricker anastomosis after a radical cystoprostatectomy and, a history of bacteremias caused by extended-spectrum -lactamase-positive Escherichia coli, Enterococcus faecium, and Candida albicans. He presented with persistent low back pain and was diagnosed with vertebral osteomyelitis, for which he received ertapenem-linezolid treatment. However, after 20 days, linezolid had to be discontinued because of myelotoxicity and metabolic acidosis. The patient was switched to tedizolid, which, in combination with ertapenem, was successfully given for 114 days until biopsy showed no growth of gram-positive cocci. We conclude that tedizolid can be an alternative to linezolid in case of toxicity, especially in long-term treatments
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