31 research outputs found
Gravitationally Lensed Quasar SDSS J1442+4055: Redshifts of Lensing Galaxies, Time Delay, Microlensing Variability, and Intervening Metal System at z ∼2
We present r-band photometric monitoring of the two images, A and B, of the gravitationally lensed quasar SDSS J1442+4055 using the Liverpool Telescope (LT). From the LT light curves between 2015 December and 2018 August, we derive at once a time delay of 25.0 ± 1.5 days (1σ confidence interval; A is leading) and microlensing magnification gradients below 10-4 mag day-1. The delay interval is not expected to be affected by an appreciable microlensing-induced bias, so it can be used to estimate cosmological parameters. This paper also focuses on new Gran Telescopio Canarias (GTC) and LT spectroscopic observations of the lens system. We determine the redshift of two bright galaxies around the doubly imaged quasar using LT spectroscopy, while GTC data lead to low-noise individual spectra of A, B, and the main lensing galaxy, G1. The G1 spectral shape is accurately matched to an early-type galaxy template at z = 0.284, and it has potential for further relevant studies. Additionally, the quasar spectra show absorption by metal-rich gas at z ~ 2. This dusty absorber is responsible for an extinction bump at a rest-frame wavelength of 2209 ± 2 Å, which has strengths of ~0.47 and 0.76 mag μm−1 for A and B, respectively. In such an intervening system, the dust-to-gas ratio, gas-phase metallicity indicator [Zn/H], and dust depletion level [Fe/Zn] are relatively hig.We are grateful to the SDSS collaboration for doing that public database. This research as been conducted in the framework of the Gravitational LENses and DArk MAtter (GLENDAMA) project, which was /is supported by Spanish Department of Research, Development and Innovation grant AYA2013-47744-C3-2-P; MINECO/AEI/FEDER-UE grant AYA2017-89815-P; the complementary action “Lentes Gravitatorias y Materia Oscura” financed by the SOciedad para el DEsarrollo Regional de CANtabria (SODERCAN S.A.); the Operational Programme of FEDER-UE; and the University of Cantabri
Dynamic purine signaling and metabolism during neutrophil–endothelial interactions
During episodes of hypoxia and inflammation, polymorphonuclear leukocytes (PMN) move into underlying tissues by initially passing between endothelial cells that line the inner surface of blood vessels (transendothelial migration, TEM). TEM creates the potential for disturbances in vascular barrier and concomitant loss of extravascular fluid and resultant edema. Recent studies have demonstrated a crucial role for nucleotide metabolism and nucleoside signaling during inflammation. These studies have implicated multiple adenine nucleotides as endogenous tissue protective mechanisms invivo. Here, we review the functional components of vascular barrier, identify strategies for increasing nucleotide generation and nucleoside signaling, and discuss potential therapeutic targets to regulate the vascular barrier during inflammation
Physiological roles for ecto-5’-nucleotidase (CD73)
Nucleotides and nucleosides influence nearly every aspect of physiology and pathophysiology. Extracellular nucleotides are metabolized through regulated phosphohydrolysis by a series of ecto-nucleotidases. The formation of extracellular adenosine from adenosine 5’-monophosphate is accomplished primarily through ecto-5’-nucleotidase (CD73), a glycosyl phosphatidylinositol-linked membrane protein found on the surface of a variety of cell types. Recent in vivo studies implicating CD73 in a number of tissue protective mechanisms have provided new insight into its regulation and function and have generated considerable interest. Here, we review contributions of CD73 to cell and tissue stress responses, with a particular emphasis on physiologic responses to regulated CD73 expression and function, as well as new findings utilizing Cd73-deficient animals
SEE-THROUGH IMAGING OF LASER-SCANNED 3D CULTURAL HERITAGE OBJECTS BASED ON STOCHASTIC RENDERING OF LARGE-SCALE POINT CLOUDS
We propose a method for the precise 3D see-through imaging, or transparent visualization, of the large-scale and complex point
clouds acquired via the laser scanning of 3D cultural heritage objects. Our method is based on a stochastic algorithm and directly
uses the 3D points, which are acquired using a laser scanner, as the rendering primitives. This method achieves the correct depth
feel without requiring depth sorting of the rendering primitives along the line of sight. Eliminating this need allows us to avoid long
computation times when creating natural and precise 3D see-through views of laser-scanned cultural heritage objects. The opacity of
each laser-scanned object is also flexibly controllable. For a laser-scanned point cloud consisting of more than 107 or 108 3D points,
the pre-processing requires only a few minutes, and the rendering can be executed at interactive frame rates. Our method enables the
creation of cumulative 3D see-through images of time-series laser-scanned data. It also offers the possibility of fused visualization for
observing a laser-scanned object behind a transparent high-quality photographic image placed in the 3D scene. We demonstrate the
effectiveness of our method by applying it to festival floats of high cultural value. These festival floats have complex outer and inner
3D structures and are suitable for see-through imaging