1,983 research outputs found
Multiwavelength active optics Shack-Hartmann sensor for seeing and turbulence outer scale monitoring
Real-time seeing and outer scale estimation at the location of the focus of a
telescope is fundamental for the adaptive optics systems dimensioning and
performance prediction, as well as for the operational aspects of instruments.
This study attempts to take advantage of multiwavelength long exposure images
to instantaneously and simultaneously derive the turbulence outer scale and
seeing from the full-width at half-maximum (FWHM) of seeing-limited images
taken at the focus of a telescope. These atmospheric parameters are commonly
measured in most observatories by different methods located away from the
telescope platform, and thus differing from the effective estimates at the
focus of a telescope, mainly because of differences in pointing orientation,
height above the ground, or local seeing bias (dome contribution). Long
exposure images can either directly be provided by any multiwavelength
scientific imager or spectrograph, or alternatively from a modified active
optics Shack-Hartmann sensor (AOSH). From measuring simultaneously the AOSH
sensor spot point spread function FWHMs at different wavelengths, one can
estimate the instantaneous outer scale in addition to seeing. Although AOSH
sensors are specified to measure not spot sizes but slopes, real-time r0 and L0
measurements from spot FWHMs can be obtained at the critical location where
they are needed with major advantages over scientific instrument images:
insensitivity to the telescope field stabilization, and being continuously
available. Assuming an alternative optical design allowing simultaneous
multiwavelength images, AOSH sensor gathers all the advantages for real-time
seeing and outer scale monitoring. With the substantial interest in the design
of extremely large telescopes, such a system could have a considerable
importance.Comment: Accepted for publication in A&A. arXiv admin note: text overlap with
arXiv:1201.233
Gyrochronology of Wide Binaries in the Kepler K2 Fields
Gyrochronology is the method of determining a stars age based on its rotation period and mass. A cool main sequence star loses it\u27s angular momentum as it ages, so the rotation rate slows down. Gyrochronology has been tested on star clusters in previous studies and now we are applying the theory to binary stars. Components of a binary should be the same age, so Gyrochronology should return the same age for both stars in binary systems. We examined the rotation periods for 290 wide binary main sequence stars in the Kepler K2 fields. These observations are part of a continuing investigation of Gyrochronology. Using the determined rotation periods and color index (a proxy for mass), we estimated ages for ~20 binary pairs. Presented here is a status report on our analysis of data from the K2 and the calculated ages of the studied binaries
Ertapenem Resistance of Escherichia coli
An ertapenem-resistant Escherichia coli isolate was recovered from peritoneal fluid in a patient who had been treated with imipenem/cilastatin for 10 days. Ertapenem resistance may be explained by a defect in the outer membrane protein and production of extended-spectrum β-lactamase CTX-M-2
Unexpected Occurrence of Plasmid-Mediated Quinolone Resistance Determinants in Environmental Aeromonas spp.
Identification of plasmid-mediated qnr genes outside Enterobacteriaceae underlines a possible diffusion of those resistance determinants within gram-negative rods
Driving next-generation autophagy researchers towards translation (DRIVE), an international PhD training program on autophagy
The European autophagy consortium Driving next-generation autophagy researchers towards translation (DRIVE) held its kick-off meeting in Groningen on the 14(th) and 15(th) of June 2018. This Marie Sklodowska-Curie Early Training Network was approved under the European Union's Horizon 2020 Research and Innovation Program and is funded for 4 years. Within DRIVE, 14 European research teams from academia and industry will train 15 PhD students through applied, cross-disciplinary and collaborative macroautophagy/autophagy research. The goal of DRIVE is to stimulate applied approaches in autophagy research and provide training towards translation, while advancing our knowledge on autophagy in specific physiological and pathological states. The strong focus on translation will prepare the PhD students to be at the forefront to exploit autophagy for the development of therapies directly benefitting patients. Thereby, DRIVE will contribute to filling the educational gap that currently exists between academia and industry, and will prepare its PhD students for alternative and highly flexible professional paths.Non peer reviewe
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