Ikerbasque

About: Ikerbasque is a other organization based out in Bilbao, Spain. It is known for research contribution in the topics: Graphene & Quantum. The organization has 713 authors who have published 7967 publications receiving 231990 citations. The organization is also known as: Basque Foundation for Science.

Biological membranes in EV biogenesis, stability, uptake, and cargo transfer: an ISEV position paper arising from the ISEV membranes and EVs workshop

Abstract: Paracrine and endocrine roles have increasingly been ascribed to extracellular vesicles (EVs) generated by multicellular organisms. Central to the biogenesis, content, and function of EVs are their delimiting lipid bilayer membranes. To evaluate research progress on membranes and EVs, the International Society for Extracellular Vesicles (ISEV) conducted a workshop in March 2018 in Baltimore, Maryland, USA, bringing together key opinion leaders and hands-on researchers who were selected on the basis of submitted applications. The workshop was accompanied by two scientific surveys and covered four broad topics: EV biogenesis and release; EV uptake and fusion; technologies and strategies used to study EV membranes; and EV transfer and functional assays. In this ISEV position paper, we synthesize the results of the workshop and the related surveys to outline important outstanding questions about EV membranes and describe areas of consensus. The workshop discussions and survey responses reveal that while much progress has been made in the field, there are still several concepts that divide opinion. Good consensus exists in some areas, including particular aspects of EV biogenesis, uptake and downstream signalling. Areas with little to no consensus include EV storage and stability, as well as whether and how EVs fuse with target cells. Further research is needed in these key areas, as a better understanding of membrane biology will contribute substantially towards advancing the field of extracellular vesicles.

Understanding caustic crossings in giant arcs: Characteristic scales, event rates, and constraints on compact dark matter

Abstract: The recent discovery of fast transient events near critical curves of massive galaxy clusters, which are interpreted as highly magnified individual stars in giant arcs due to caustic crossing, opens up the possibility of using such microlensing events to constrain a range of dark matter models such as primordial black holes and scalar field dark matter. Based on a simple analytic model, we study lensing properties of a point mass lens embedded in a high magnification region, and we derive the dependence of the peak brightness, microlensing time scales, and event rates on the mass of the point mass lens, as well as the radius of a source star that is magnified. We find that the lens mass and source radius of the first event MACS J1149 Lensed Star 1 (LS1) are constrained, with the lens mass range of $0.1\text{ }\text{ }{M}_{\ensuremath{\bigodot}}\ensuremath{\lesssim}M\ensuremath{\lesssim}4\ifmmode\times\else\texttimes\fi{}{10}^{3}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ and the source radius range of $40{R}_{\ensuremath{\bigodot}}\ensuremath{\lesssim}R\ensuremath{\lesssim}260{R}_{\ensuremath{\bigodot}}$. In the most plausible case with $M\ensuremath{\approx}0.3\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ and $R\ensuremath{\approx}180{R}_{\ensuremath{\bigodot}}$, the source star should have been magnified by a factor of $\ensuremath{\approx}4300$ at the peak. The derived lens properties are fully consistent with the interpretation that MACS J1149 LS1 is a microlensing event produced by a star that contributes to the intracluster light. We argue that compact dark matter models with high fractional mass densities for the mass range ${10}^{\ensuremath{-}5}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}\ensuremath{\lesssim}M\ensuremath{\lesssim}{10}^{2}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ are inconsistent with the observation of MACS J1149 LS1 because such models predict too low magnifications. Our work demonstrates a potential use of caustic crossing events in giant arcs to constrain compact dark matter.