110 research outputs found
Magnetohydrodynamic equilibria in barotropic stars
Although barotropic matter does not constitute a realistic model for magnetic
stars, it would be interesting to confirm a recent conjecture that states that
magnetized stars with a barotropic equation of state would be dynamically
unstable (Reisenegger 2009). In this work we construct a set of barotropic
equilibria, which can eventually be tested using a stability criterion. A
general description of the ideal MHD equations governing these equilibria is
summarized, allowing for both poloidal and toroidal magnetic field components.
A new finite-difference numerical code is developed in order to solve the
so-called Grad-Shafranov equation describing the equilibrium of these
configurations, and some properties of the equilibria obtained are briefly
discussed.Comment: Conference Proceedings, Magnetic Fields in the Universe IV (2013
Nucleation of superfluid-light domains in a quenched dynamics
Strong correlation effects emerge from light-matter interactions in coupled
resonator arrays, such as the Mott-insulator to superfluid phase transition of
atom-photon excitations. We demonstrate that the quenched dynamics of a
finite-sized complex array of coupled resonators induces a first-order like
phase transition. The latter is accompanied by domain nucleation that can be
used to manipulate the photonic transport properties of the emerging superfluid
phase; this in turn leads to an empirical scaling law. This universal behavior
emerges from the light-matter interaction and the topology of the array. The
validity of our results over a wide range of complex architectures might lead
to to a promising device for use in scaled quantum simulations.Comment: 7 pages, 4 figures and supplemental material. Accepted by Scientific
Report
Evolution of fractality in space plasmas of interest to geomagnetic activity
We studied the temporal evolution of fractality for geomagnetic activity, by calculating fractal dimensions from the Dst data and from a magnetohydrodynamic shell model for turbulent magnetized plasma, which may be a useful model to study geomagnetic activity under solar wind forcing. We show that the shell model is able to reproduce the relationship between the fractal dimension and the occurrence of dissipative events, but only in a certain region of viscosity and resistivity values. We also present preliminary results of the application of these ideas to the study of the magnetic field time series in the solar wind during magnetic clouds, which suggest that it is possible, by means of the fractal dimension, to characterize the complexity of the magnetic cloud structure.Peer reviewe
An instrumental puzzle: the modular integration of AOLI
The Adaptive Optics Lucky Imager, AOLI, is an instrument developed to deliver
the highest spatial resolution ever obtained in the visible, 20 mas, from
ground-based telescopes. In AOLI a new philosophy of instrumental prototyping
has been applied, based on the modularization of the subsystems. This modular
concept offers maximum flexibility regarding the instrument, telescope or the
addition of future developments.Comment: 10 pages, 8 figures, Proc. SPIE 9908, Ground-based and Airborne
Instrumentation for Astronomy VI, 99082Z (August 9, 2016
Current State-of-the-Art Therapy for Malignant Pleural Mesothelioma and Future Options Centered on Immunotherapy
Biomarkers; Immunotherapy; Malignant pleural mesotheliomaBiomarcadores; Inmunoterapia; Mesotelioma pleural malignoBiomarcadors; Immunoterà pia; Mesotelioma pleural maligneMalignant pleural mesothelioma (MPM) is a locally aggressive disease related to asbestos exposure with a median survival for untreated patients of 4–8 months. The combination of chemotherapy based on platinum and antifolate is the standard treatment, and the addition of bevacizumab adds two months to median survival. Recently, in first-line treatment, immunotherapy combining nivolumab with ipilimumab has been shown to be superior to chemotherapy in the CheckMate-743 study in terms of overall survival (18.1 months), leading to its approval by the FDA and EMA. The positive results of this study represent a new standard of treatment for patients with MPM; however, not all patients will benefit from immunotherapy treatment. In an effort to improve the selection of patient candidates for immunotherapy for different tumors, biomarkers that have been associated with a greater possibility of response to treatment have been described. MPM is a type of tumor with low mutational load and neo-antigens, making it a relatively non-immunogenic tumor for T cells and possibly less susceptible to responding to immunotherapy. Different retrospective studies have shown that PD-L1 expression occurs in 20–40% of patients and is associated with a poor prognosis; however, the predictive value of PD-L1 in response to immunotherapy has not been confirmed. The purpose of this work is to review the state of the art of MPM treatment in the year 2023, focusing on the efficacy results of first-line or subsequent immunotherapy studies on patients with MPM and possible chemo-immunotherapy combination strategies. Additionally, potential biomarkers of response to immunotherapy will be reviewed, such as histology, PD-L1, lymphocyte populations, and TMB
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