We study the incidence rate of damped systems associated with the host galaxies of gamma-ray bursts Lya (GRB-host DLAs) as functions of neutral hydrogen column density ( ) and projected star formation rate (SFR) NH i using cosmological SPH simulations. Assuming that the occurrence of GRBs is correlated with the local SFR, we find that the median of GRB-host DLAs progressively shifts to lower va...

The polarization of the optical afterglow (AG) of Gamma-Ray Bursts (GRBs) has only been measured in a few instances at various times after the GRB. In all cases except the best measured one (GRB 030329) the observed polarization and its evolution are simple and easy to explain in the most naive version of the “Cannonball” model of GRBs: the “intrinsic” AG polarization is small and the observati...

Cosmological gamma ray bursts (GRBs) are the brightest explosions in the Universe. Satellite detectors, such as Beppo-SAX, HETE2 and more recently Swift, have provided a wealth of data, including the localization and redshifts of subsets of GRBs. The redshift distribution has been utilized in several studies in attempts to constrain the evolving star formation rate and to probe GRB rate evoluti...

GRB 970508 is the second gamma-ray burst (GRB) for which an optical afterglow has been detected. It is the first GRB for which a distance scale has been determined: absorption and emission features in spectra of the optical afterglow place GRB 970508 at a redshift of z ≥ 0.835 (Metzger et al. 1997a, 1997b). The lack of a Lyman-α forest in these spectra further constrains this redshift to be les...

Granzyme B (GrB), a component of the cytotoxic cell granule secretion pathway, is designed to kill infected and transformed cells after intracellular delivery by the pore forming protein, perforin. The mechanism of the delivery remains speculative. In this study we tested the hypothesis that GrB possesses capacity to bind and disrupt lipid membranes. Here in comparison to previous studies that ...

Several gamma-ray burst (GRB) luminosity indicators have been proposed, which can be generally written in the form of L̂ = c ∏ x ai i , where c is the coefficient, xi is the i-th observable, and ai is its corresponding power-law index. Unlike Type-Ia supernovae, calibration of GRB luminosity indicators using a low-redshift sample is difficult. This is because the GRB rate drops rapidly at low re...

Aims. Long-duration gamma-ray bursts (GRBs) have been found to be associated with broad-lined type-Ic supernovae (SNe), but only a handful of cases have been studied in detail. Prompted by the discovery of the exceptionally bright, nearby GRB 130427A (redshift z = 0.3399), we aim at characterising the properties of its associated SN 2013cq. This is the first opportunity to test directly the pro...

Plexiform lesions (PLs), the hallmark of plexogenic pulmonary arterial hypertension (PAH), contain phenotypically altered, proliferative endothelial cells (ECs). The molecular mechanism that contributes to EC proliferation and formation of PLs is poorly understood. We now show that a decrease in intersectin-1s (ITSN-1s) expression due to granzyme B (GrB) cleavage during inflammation associated ...

In the present study we have investigated the contribution of the insulin receptor substrate proteins (IRS-1 and IRS-2) to the insulin/insulin like growth factor I (IGF-I)-signaling pathways in fetal rat brown adipocytes, a model that expresses both insulin and IGF-I receptors. Insulin/IGF-I rapidly stimulated IRS-1 and IRS-2 tyrosine phosphorylation, their association with p85alpha, and IRS-1-...

We show that the time variability of a gamma-ray burst (GRB) appears to be correlated with the absolute luminosity of the burst: smooth bursts are intrinsically less luminosity. This Cepheid-like relationship can be used to determine the redshift of a GRB from parameters measured solely at gamma-ray energies. The relationship is based on only seven events at present and needs to be further conf...