703 research outputs found

    Effect of recombinant human nerve growth factor eye drops in patients with dry eye: a phase IIa, open label, multiple-dose study

    Get PDF
    Background: Dry eye disease (DED) affects more than 14% of the elderly population causing decrease of quality of life, high costs and vision impairment. Current treatments for DED aim at lubricating and controlling inflammation of the ocular surface. Development of novel therapies targeting different pathogenic mechanisms is sought-after. The aim of this study is to evaluate safety and efficacy of recombinant human nerve growth factor (rhNGF) eye drops in patients with DED. Methods: Forty consecutive patients with moderate to severe DED were included in a phase IIa, prospective, open label, multiple-dose, clinical trial to receive rhNGF eye drops at 20 μg/mL (Group 1: G1) or at 4 μg/mL (Group 2: G2) concentrations, two times a day in both eyes for 28 days (NCT02101281). The primary outcomes measures were treatment-emerged adverse events (AE), Symptoms Assessment in Dry Eye (SANDE) scale, ocular surface staining and Schirmer test. Results: Of 40 included patients, 39 completed the trial. Both tested rhNGF eye drop concentrations were safe and well tolerated. Twenty-nine patients experienced at least one AE (14 in G1 and 15 in G2), of which 11 had at least 1 related AE (8 in G1 and 3 in G2). Both frequency and severity of DED symptoms and ocular surface damage showed significant improvement in both groups, while tear function improved only in G1. Conclusions: The data of this study indicate that rhNGF eye drops in both doses is safe and effective in improving symptoms and signs of DED. Randomised clinical trials are ongoing to confirm the therapeutic benefit of rhNGF in DED. Trial registration number: NCT02101281

    Clustering of galaxies around GRB sight-lines

    Full text link
    There is evidence of an overdensity of strong intervening MgII absorption line systems distributed along the lines of sight towards GRB afterglows relative to quasar sight-lines. If this excess is real, one should also expect an overdensity of field galaxies around GRB sight-lines, as strong MgII tends to trace these sources. In this work, we test this expectation by calculating the two point angular correlation function of galaxies within 120^{\prime\prime} (470 h711 Kpc\sim470~h_{71}^{-1}~\mathrm{Kpc} at z0.4\langle z\rangle \sim0.4) of GRB afterglows. We compare the Gamma-ray burst Optical and Near-infrared Detector (GROND) GRB afterglow sample -- one of the largest and most homogeneous samples of GRB fields -- with galaxies and AGN found in the COSMOS-30 photometric catalog. We find no significant signal of anomalous clustering of galaxies at an estimated median redshift of z0.3z\sim0.3 around GRB sight-lines, down to KAB<19.3K_{\mathrm{AB}}<19.3. This result is contrary to the expectations from the MgII excess derived from GRB afterglow spectroscopy, although many confirmed galaxy counterparts to MgII absorbers may be too faint to detect in our sample -- especially those at z>1z>1. We note that the addition of higher sensitivity Spitzer IRAC or HST WFC3 data for even a subset of our sample would increase this survey's depth by several orders of magnitude, simultaneously increasing statistics and enabling the investigation of a much larger redshift space.}Comment: 10 pages, 6 figures. A&A accepte

    Indium joints for cryogenic gravitational wave detectors

    Get PDF
    A viable technique for the preparation of highly thermal conductive joints between sapphire components in gravitational wave detectors is presented. The mechanical loss of such a joint was determined to be as low as 2 × 10−3 at 20 K and 2 × 10−2 at 300 K. The thermal noise performance of a typical joint is compared to the requirements of the Japanese gravitational wave detector, KAGRA. It is shown that using such an indium joint in the suspension system allows it to operate with low thermal noise. Additionally, results on the maximum amount of heat which can be extracted via indium joints are presented. It is found that sapphire parts, joined by means of indium, are able to remove the residual heat load in the mirrors of KAGRA

    International Space Station Columbus Payload SoLACES Degradation Assessment

    Get PDF
    SOLAR is a European Space Agency (ESA) payload deployed on the International Space Station (ISS) and located on the Columbus Laboratory. It is located on the Columbus External Payload Facility in a zenith location. The objective of the SOLAR payload is to study the Sun. The SOLAR payload consists of three instruments that allow for measurement of virtually the entire electromagnetic spectrum (17 nm to 2900 nm). The three payload instruments are SOVIM (SOlar Variable and Irradiance Monitor), SOLSPEC (SOLar SPECctral Irradiance measurements), and SolACES (SOLar AutoCalibrating Extreme UV/UV Spectrophotometers)

    Gamma-Ray Bursts Trace UV Metrics of Star Formation over 3 < z < 5

    Get PDF
    We present the first uniform treatment of long duration gamma-ray burst (GRB) host galaxy detections and upper limits over the redshift range 3<z<5, a key epoch for observational and theoretical efforts to understand the processes, environments, and consequences of early cosmic star formation. We contribute deep imaging observations of 13 GRB positions yielding the discovery of eight new host galaxies. We use this dataset in tandem with previously published observations of 31 further GRB positions to estimate or constrain the host galaxy rest-frame ultraviolet (UV; 1600 A) absolute magnitudes M_UV. We then use the combined set of 44 M_UV estimates and limits to construct the M_UV luminosity function (LF) for GRB host galaxies over 3<z<5 and compare it to expectations from Lyman break galaxy (LBG) photometric surveys with the Hubble Space Telescope. Adopting standard prescriptions for the luminosity dependence of galaxy dust obscuration (and hence, total star formation rate), we find that our LF is compatible with LBG observations over a factor of 600x in host luminosity, from M_UV = -22.5 mag to >-15.6 mag, and with extrapolations of the assumed Schechter-type LF well beyond this range. We review proposed astrophysical and observational biases for our sample, and find they are for the most part minimal. We therefore conclude, as the simplest interpretation of our results, that GRBs successfully trace UV metrics of cosmic star formation over the range 3<z<5. Our findings suggest GRBs are providing an accurate picture of star formation processes from z ~3 out to the highest redshifts.Comment: publ. ApJ 809 (2015) 76; 14 figures; replacement to reflect changes to v1 (rounding effects, diff. LF from Bouwens

    Multiwavelength analysis of three SNe associated with GRBs observed by GROND

    Get PDF
    After the discovery of the first connection between GRBs and SNe almost two decades ago, tens of SN-like rebrightenings have been discovered and about seven solid associations have been spectroscopically confirmed to date. Using GROND optical/NIR data and Swift X-ray/UV data, we estimate the intrinsic extinction, luminosity, and evolution of three SN rebrightenings in GRB afterglow light curves at z~0.5. The SNe 2008hw, 2009nz, and 2010ma exhibit 0.80, 1.15, and 1.78 times the optical (r band) luminosity of SN 1998bw, respectively. While SN 2009nz evolves similarly to SN 1998bw, SNe 2008hw and 2010ma show earlier peak times. The quasi-bolometric light curves were corrected for the contribution of the NIR bands using data available in the literature and blackbody fits. The large luminosity of SN 2010ma (1.4x10^43 erg/s) is confirmed, while SNe 2008hw and 2009nz reached a peak luminosity closer to SN 1998bw. Physical parameters of the SN explosions, such as synthesised nickel mass, ejecta mass, and kinetic energy, are estimated using Arnett's analytic approach, which resulted in nickel masses of around 0.4-0.5 Msun. By means of the a very comprehensive data set, we found that the luminosity and the nickel mass of SNe 2008hw, 2009nz, and 2010ma resembles those of other known GRB-associated SNe. This findings strengthens previous claims of GRB-SNe being brighter than type-Ic SNe unaccompanied by GRBs.Comment: 11 pages, 9 figures, accepted for publication in Astronomy & Astrophysics, abstract abridge

    Another short-burst host galaxy with an optically obscured high star formation rate: The case of GRB 071227

    Full text link
    We report on radio continuum observations of the host galaxy of the short gamma-ray burst 071227 (z=0.381) with the Australia Telescope Compact Array (ATCA). We detect the galaxy in the 5.5 GHz band with an integrated flux density of Fnu = 43 +/- 11 microJy, corresponding to an unobscured star-formation rate (SFR) of about 24 Msun/yr, forty times higher than what was found from optical emission lines. Among the ~30 well-identified and studied host galaxies of short bursts this is the third case where the host is found to undergo an episode of intense star formation. This suggests that a fraction of all short-burst progenitors hosted in star-forming galaxies could be physically related to recent star formation activity, implying a relatively short merger time scale.Comment: 6 pages, ApJ, accepted for publicatio

    Super-solar metallicity at the position of the ultra-long GRB130925A

    Get PDF
    Over the last decade there has been immense progress in the follow-up of short and long GRBs, resulting in a significant rise in the detection rate of X-ray and optical afterglows, in the determination of GRB redshifts, and of the identification of the underlying host galaxies. Nevertheless, our theoretical understanding on the progenitors and central engines powering these vast explosions is lagging behind, and a newly identified class of `ultra-long' GRBs has fuelled speculation on the existence of a new channel of GRB formation. In this paper we present high signal-to-noise X-shooter observations of the host galaxy of GRB130925A, which is the fourth unambiguously identified ultra-long GRB, with prompt gamma-ray emission detected for ~20ks. The GRB line of sight was close to the host galaxy nucleus, and our spectroscopic observations cover both this region along the bulge/disk of the galaxy, in addition to a bright star-forming region within the outskirts of the galaxy. From our broad wavelength coverage we obtain accurate metallicity and dust-extinction measurements at both the galaxy nucleus, and an outer star-forming region, and measure a super-solar metallicity at both locations, placing this galaxy within the 10-20% most metal-rich GRB host galaxies. Such a high metal enrichment has implications on the progenitor models of both long and ultra-long GRBs, although the edge-on orientation of the host galaxy does not allow us to rule out a large metallicity variation along our line of sight. The spatially resolved spectroscopic data presented in this paper offer important insight into variations in the metal and dust abundance within GRB host galaxies. They also illustrate the need for IFU observations on a larger sample of GRB host galaxies at varies metallicities to provide a more quantitative view on the relation between the GRB circumburst and the galaxy-whole properties.Comment: 9 pages, 3 figures, A&A in press, matches published versio

    The Afterglow and Environment of the Short GRB111117A

    Full text link
    We present multi-wavelength observations of the afterglow of the short GRB111117A, and follow-up observations of its host galaxy. From rapid optical and radio observations we place limits of r \gtrsim 25.5 mag at \deltat \approx 0.55 d and F_nu(5.8 GHz) < 18 \muJy at \deltat \approx 0.50 d, respectively. However, using a Chandra observation at t~3.0 d we locate the absolute position of the X-ray afterglow to an accuracy of 0.22" (1 sigma), a factor of about 6 times better than the Swift-XRT position. This allows us to robustly identify the host galaxy and to locate the burst at a projected offset of 1.25 +/- 0.20" from the host centroid. Using optical and near-IR observations of the host galaxy we determine a photometric redshift of z=1.3 (+0.3,-0.2), one of the highest for any short GRB, and leading to a projected physical offset for the burst of 10.5 +/- 1.7 kpc, typical of previous short GRBs. At this redshift, the isotropic gamma-ray energy is E_{gamma,iso} \approx 3\times10^51 erg (rest-frame 23-2300 keV) with a peak energy of E_{pk} \approx 850-2300 keV (rest-frame). In conjunction with the isotropic X-ray energy, GRB111117A appears to follow our recently-reported E_x,iso-E_gamma,iso-E_pk universal scaling. Using the X-ray data along with the optical and radio non-detections we find that for a blastwave kinetic energy of E_{K,iso} \approx E_{gamma,iso}, the circumburst density is n_0 \sim 3x10^(-4)-1 cm^-3 (for a range of epsilon_B=0.001-0.1). Similarly, from the non-detection of a break in the X-ray light curve at t<3 d, we infer a minimum opening angle for the outflow of theta_j> 3-10 degrees (depending on the circumburst density). We conclude that Chandra observations of short GRBs are effective at determining precise positions and robust host galaxy associations in the absence of optical and radio detections.Comment: ApJ accepted versio
    corecore