1,186 research outputs found

    Incidence of the protozoan Perkinsus sp. on a cultivated population of the carpet shell clam Ruditapes decussatus (L., 1758) in the Arousa ria (northwestern Spain)

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    La almeja fina Ruditapes decussatus L., 1758 es una especie importante en el sector pesquero gallego, con una producción que se ha situado en 760 t en el año 2000. La escasa información disponible sobre el crecimiento de esta especie establece en cuatro años el tiempo necesario para alcanzar la talla legal de extracción: 40 mm de longitud. En este trabajo se obtiene el mismo crecimiento en 27 meses y se muestra la importancia del sustrato sobre el crecimiento y el índice de condición, así como la incidencia de la infección por Perkinsus sp., que consigue prevalencias (porcentaje de almejas infectadas) de hasta el 100%.The carpet shell clam Ruditapes decussatus L., 1758 is a major species in the fishery of Galicia (northwestern Spain), with a production of 760 t in 2000. Information regarding the growth of this species is scarce, and it was formerly estimated that it took 4 years to achieve the legal size (40 mm length). However, the present paper shows that the same length can be obtained in 27 months. The importance of the substrate on the species's growth and condition index is also discussed, as well as the infestation of Perkinsus sp., with a prevalence as high as 100%.Instituto Español de Oceanografí

    High-Flow Oxygen with Capping or Suctioning for Tracheostomy Decannulation

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    9 p.BACKGROUND When patients with a tracheostomy tube reach a stage in their care at which decannulation appears to be possible, it is common practice to cap the tracheostomy tube for 24 hours to see whether they can breathe on their own. Whether this approach to establishing patient readiness for decannulation leads to better outcomes than one based on the frequency of airway suctioning is unclear. METHODS In five intensive care units (ICUs), we enrolled conscious, critically ill adults who had a tracheostomy tube; patients were eligible after weaning from mechanical ventilation. In this unblinded trial, patients were randomly assigned either to undergo a 24-hour capping trial plus intermittent high-flow oxygen therapy (control group) or to receive continuous high-flow oxygen therapy with frequency of suctioning being the indicator of readiness for decannulation (intervention group). The primary outcome was the time to decannulation, compared by means of the log-rank test. Secondary outcomes included decannulation failure, weaning failure, respiratory infections, sepsis, multiorgan failure, durations of stay in the ICU and hospital, and deaths in the ICU and hospital. RESULTS The trial included 330 patients; the mean (±SD) age of the patients was 58.3±15.1 years, and 68.2% of the patients were men. A total of 161 patients were assigned to the control group and 169 to the intervention group. The time to decannulation was shorter in the intervention group than in the control group (median, 6 days [interquartile range, 5 to 7] vs. 13 days [interquartile range, 11 to 14]; absolute difference, 7 days [95% confidence interval, 5 to 9]). The incidence of pneumonia and tracheobronchitis was lower, and the duration of stay in the hospital shorter, in the intervention group than in the control group. Other secondary outcomes were similar in the two groups. CONCLUSIONS Basing the decision to decannulate on suctioning frequency plus continuous highflow oxygen therapy rather than on 24-hour capping trials plus intermittent highflow oxygen therapy reduced the time to decannulation, with no evidence of a between-group difference in the incidence of decannulation failure. (REDECAP ClinicalTrials.gov number, NCT02512744.

    Wavelength calibration for OSIRIS/GTC* tunable filters

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    OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the first light instrument of the Gran Telescopio Canarias (GTC). It provides a flexible and competitive tunable filter (TF). Since it is based on a Fabry-Perot interferometer working in collimated beam, the TF transmission wavelength depends on the position of the target with respect to the optical axis. This effect is non-negligible and must be accounted for in the data reduction. Our paper establishes a wavelength calibration for OSIRIS TF with the accuracy required for spectrophotometric measurements using the full field of view (FOV) of the instrument. The variation of the transmission wavelength λ(R)\lambda(R) across the FOV is well described by λ(R)=λ(0)/1+(R/f2)2\lambda(R)=\lambda(0)/\sqrt{1+(R/f_2)^2}, where λ(0)\lambda(0) is the central wavelength, RR represents the physical distance from the optical axis, and f2=185.70±0.17f_2=185.70\pm0.17\,mm is the effective focal length of the camera lens. This new empirical calibration yields an accuracy better than 1\,\AA\ across the entire OSIRIS FOV (\sim8\arcmin×\times8\arcmin), provided that the position of the optical axis is known within 45 μ\mum (\equiv 1.5 binned pixels). We suggest a calibration protocol to grant such precision over long periods, upon re-alignment of OSIRIS optics, and in different wavelength ranges. This calibration differs from the calibration in OSIRIS manual which, nonetheless, provides an accuracy 1\lesssim1\AA\, for R\lesssim 2\arcmin.Comment: 22 pages, 7 figures, accepted for publication in PAS

    A mid-infrared view of the inner parsecs of the Seyfert galaxy Mrk 1066 using CanariCam/GTC

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    We present mid-infrared (MIR) imaging and spectroscopic data of the Seyfert 2 galaxy Mrk 1066 obtained with CanariCam (CC) on the 10.4-m Gran Telescopio CANARIAS (GTC). The galaxy was observed in imaging mode with an angular resolution of 0.24 arcsec (54 pc) in the Si-2 filter (8.7 μm). The image reveals a series of star-forming knots within the central ∼400 pc, after subtracting the dominant active galactic nucleus (AGN) component. We also subtracted this AGN unresolved component from the 8–13 μm spectra of the knots and the nucleus, and measured equivalent widths (EWs) of the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature which are typical of pure starburst galaxies. This EW is larger in the nucleus than in the knots, confirming that, at least in the case of Mrk 1066, the AGN dilutes, rather than destroys, the molecules responsible for the 11.3 μm PAH emission. By comparing the nuclear GTC/CC spectrum with the Spitzer/Infrared Spectrograph (IRS) spectrum of the galaxy, we find that the AGN component that dominates the continuum emission at λ < 15 μm on scales of ∼60 pc (90–100 per cent) decreases to 35–50 per cent when the emission of the central ∼830 pc is considered. On the other hand, the AGN contribution dominates the 15–25 μm emission (75 per cent) on the scales probed by Spitzer/IRS. We reproduced the nuclear infrared emission of the galaxy with clumpy torus models, and derived a torus gas mass of 2 × 10^5  M_⊙, contained in a clumpy structure of ∼2 pc radius and with a column density compatible with Mrk 1066 being a Compton-thick candidate, in agreement with X-ray observations. We find a good match between the MIR morphology of Mrk 1066 and the extended Paβ, Brγ and [O iii] λ5007 emission. This coincidence implies that the 8.7 μm emission is probing star formation, dust in the narrow-line region and the oval structure previously detected in the near-infrared. On the other hand, the Chandra soft X-ray morphology does not match any of the previous, contrary to what it is generally assumed for Seyfert galaxies. A thermal origin for the soft X-ray emission, rather than AGN photoionization, is suggested by the different data analysed here
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