Towards coordinated regional multi-satellite InSAR volcano observations:results from the Latin America pilot project

Within Latin America, about 319 volcanoes have been active in the Holocene, but 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) developed a 4-year pilot project (2013-2017) to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring as well as with the international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). The goal is to make sure that the most useful data are collected at each volcano following the guidelines of the Santorini report that observation frequency is related to volcano activity, and to communicate the results to the local institutions in a timely fashion. Here we highlight how coordinated multi-satellite observations have been used by volcano observatories to monitor volcanoes and respond to crises. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR), which have been used in conjunction with other observations to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. During this time period, we find 26 volcanoes deforming, including 18 of the 28 volcanoes that erupted – those eruptions without deformation were less than 2 on the VEI scale. Another 7 volcanoes were restless and the volcano observatories requested satellite observations, but no deformation was detected. We describe the lessons learned about the data products and information that are most needed by the volcano observatories in the different countries using information collected by questionnaires. We propose a practical strategy for regional to global satellite volcano monitoring for use by volcano observatories in Latin America and elsewhere to realize the vision of the Santorini report

Magma plumbing systems: a geophysical perspective

Over the last few decades, significant advances in using geophysical techniques to image the structure of magma plumbing systems have enabled the identification of zones of melt accumulation, crystal mush development, and magma migration. Combining advanced geophysical observations with petrological and geochemical data has arguably revolutionised our understanding of, and afforded exciting new insights into, the development of entire magma plumbing systems. However, divisions between the scales and physical settings over which these geophysical, petrological, and geochemical methods are applied still remain. To characterise some of these differences and promote the benefits of further integration between these methodologies, we provide a review of geophysical techniques and discuss how they can be utilised to provide a structural context for and place physical limits on the chemical evolution of magma plumbing systems. For example, we examine how Interferometric Synthetic Aperture Radar (InSAR), coupled with Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) data, and seismicity may be used to track magma migration in near real-time. We also discuss how seismic imaging, gravimetry and electromagnetic data can identify contemporary melt zones, magma reservoirs and/or crystal mushes. These techniques complement seismic reflection data and rock magnetic analyses that delimit the structure and emplacement of ancient magma plumbing systems. For each of these techniques, with the addition of full-waveform inversion (FWI), the use of Unmanned Aerial Vehicles (UAVs) and the integration of geophysics with numerical modelling, we discuss potential future directions. We show that approaching problems concerning magma plumbing systems from an integrated petrological, geochemical, and geophysical perspective will undoubtedly yield important scientific advances, providing exciting future opportunities for the volcanological community

Time-Course Effects of Centrally Administered Native Urotensin-II on Motor and Cardioventilatory Activity in Trout

International audienceAlthough in most vertebrate species urotensin-II (UII) is synthesized in neurons of the central nervous system, little is known regarding the physiological actions of UII in the brain. We have investigated the effects of intracerebroventricular (ICV) administration of synthetic trout UII (1, 5, and 50 pmol) on total motor activity (ACT), ventilatory frequency (VF), ventilatory amplitude (VA), and heart rate (HR) in the unanesthetized trout. ICV injection of UII increased ACT in a dose-dependent manner, and the maximal effect was observed at a dose of 5 pmol. At doses of 1 and 5 pmol, UII did not affect VF, VA, or HR. At the highest dose tested (50 pmol), UII not only increased ACT, but also significantly activated VF, VA, and HR. In contrast, ICV injection of synthetic trout angiotensin-II (5 pmol) did not produce any effect on ACT, VF, or VA, but sharply increased HR. These data provide the first evidence that UII can act centrally to induce motor activity in a nonmammalian vertebrate species

COMSOL Model Data from Sierra Negra Volcano Galapagos Ecuador, 2005 Eruption Precursors

The following files are model data generated by COMSOL Multiphysics 5.3. Our numerical approach utilizes previously developed and benchmarked, thermomechanical and fluid-structure interaction FEM models. COMSOL Multiphysics 5.3a calculates the stress, strain, and temperature variations due to a viscous magma flowing from a deeper source into an existing, magma-filled reservoir. Model rheology implantations include: non-Temperature-dependent, Temperature-dependent, and Temperature-dependent with pre-existing weakness. Model outputs includes: Time, vertical deformation, optimized flux, change in overpressure, maximum tensile stress, and temperature

International Union of Basic and Clinical Pharmacology. XCII. Urotensin II, urotensin II-related peptide, and their receptor: from structure to function.

International audienceUrotensin II (UII) is a cyclic neuropeptide that was first isolated from the urophysis of teleost fish on the basis of its ability to contract the hindgut. Subsequently, UII was characterized in tetrapods including humans. Phylogenetic studies and synteny analysis indicate that UII and its paralogous peptide urotensin II-related peptide (URP) belong to the somatostatin/cortistatin superfamily. In mammals, the UII and URP genes are primarily expressed in cholinergic neurons of the brainstem and spinal cord. UII and URP mRNAs are also present in various organs notably in the cardiovascular, renal, and endocrine systems. UII and URP activate a common G protein-coupled receptor, called UT, that exhibits relatively high sequence identity with somatostatin, opioid, and galanin receptors. The UT gene is widely expressed in the central nervous system (CNS) and in peripheral tissues including the retina, heart, vascular bed, lung, kidney, adrenal medulla, and skeletal muscle. Structure-activity relationship studies and NMR conformational analysis have led to the rational design of a number of peptidic and nonpeptidic UT agonists and antagonists. Consistent with the wide distribution of UT, UII has now been shown to exert a large array of biologic activities, in particular in the CNS, the cardiovascular system, and the kidney. Here, we review the current knowledge concerning the pleiotropic actions of UII and discusses the possible use of antagonists for future therapeutic applications

Cationic Lipophosphoramidates Containing a Hydroxylated Polar Headgroup for Improving Gene Delivery

International audienceThe structure of the cationic moiety of amphiphiles is a key factor which directly influences their transfection efficacy. Accordingly, in the present work, we have synthesized three new lipophosphoramide-based amphiphilic compounds incorporating a methoxy 5, hydroxyl 6, or dihydroxyl 7 functional group in their cationic part. Gene delivery efficacies of these novel vectors were compared to our benchmark compound, the arsenolipophosphoramidate KLN47, and to its trimethylammonium (TMA) analogue 4. We next studied the characteristics (size, ζ potential) of the nanometric assemblies formed (liposomes and lipid/DNA complexes), and the DNA binding ability of the cationic liposomes was characterized at the physicochemical level. In vitro, all of the cationic lipids evaluated were efficient not only to condense plasmids but also to transfect two types of human airway epithelial cells. Interestingly, in vivo administration to mice (via simple tail vein injection) showed that compound 6 was the most efficient in transfecting the lungs when compared to that of the other cationic lipids studied, including compound KLN47. All of these results suggest that a hydroxyethyldimethylammonium (HE-DMA) polar head could be a valuable alternative to a trimethylarsonium (TMAs) polar head and that they also invite further evaluation of the in vivo potential of compound 6 using more clinically relevant delivery procedures