An intrinsically disordered proteins community for ELIXIR.

Intrinsically disordered proteins (IDPs) and intrinsically disordered regions (IDRs) are now recognised as major determinants in cellular regulation. This white paper presents a roadmap for future e-infrastructure developments in the field of IDP research within the ELIXIR framework. The goal of these developments is to drive the creation of high-quality tools and resources to support the identification, analysis and functional characterisation of IDPs. The roadmap is the result of a workshop titled "An intrinsically disordered protein user community proposal for ELIXIR" held at the University of Padua. The workshop, and further consultation with the members of the wider IDP community, identified the key priority areas for the roadmap including the development of standards for data annotation, storage and dissemination; integration of IDP data into the ELIXIR Core Data Resources; and the creation of benchmarking criteria for IDP-related software. Here, we discuss these areas of priority, how they can be implemented in cooperation with the ELIXIR platforms, and their connections to existing ELIXIR Communities and international consortia. The article provides a preliminary blueprint for an IDP Community in ELIXIR and is an appeal to identify and involve new stakeholders

The Impact of Fleet Coordination on Taxi Operations

On-demand mobility has existed for more than 100 years in the form of taxi systems. Comparatively recently, ride-hailing schemes have also grown to a significant mode share. Most types of such one-way mobility-on-demand systems allow drivers taking independent decisions. These systems are not or only partially coordinated. In a different operating mode, all decisions are coordinated by the operator, allowing for the optimization of certain metrics. Such a coordinated operation is also implied if human-driven vehicles are replaced by self-driving cars. This work quantifies the service quality and efficiency improvements resulting from the coordination of taxi fleets. Results based on high-fidelity transportation simulations and data sets of existing taxi systems are presented for the cities of San Francisco, Chicago, and Zurich. They show that fleet coordination can strongly improve the efficiency and service level of existing systems. Depending on the operator and the city's preferences, empty vehicle distance driven and fleet sizes could be substantially reduced, or the wait times could be reduced while maintaining the current fleet sizes. The study provides clear evidence that full fleet coordination should be implemented in existing mobility-on-demand systems, even before the availability of self-driving cars.ISSN:1979-2016ISSN:2042-319

The Impact of Fleet Coordination on Taxi Operations

International audienceOn-demand mobility has existed for more than 100 years in the form of taxi systems. Comparatively recently, ride-hailing schemes have also grown to a significant mode share. Most types of such one-way mobility-on-demand systems allow drivers taking independent decisions. These systems are not or only partially coordinated. In a different operating mode, all decisions are coordinated by the operator, allowing for the optimization of certain metrics. Such a coordinated operation is also implied if human-driven vehicles are replaced by self-driving cars. This work quantifies the service quality and efficiency improvements resulting from the coordination of taxi fleets. Results based on high-fidelity transportation simulations and data sets of existing taxi systems are presented for the cities of San Francisco, Chicago, and Zurich. They show that fleet coordination can strongly improve the efficiency and service level of existing systems. Depending on the operator and the city’s preferences, empty vehicle distance driven and fleet sizes could be substantially reduced, or the wait times could be reduced while maintaining the current fleet sizes. The study provides clear evidence that full fleet coordination should be implemented in existing mobility-on-demand systems, even before the availability of self-driving cars

Experimental study of the interplay between magmatic rift intrusion and flank instability with application to the 2001 Mount Etna eruption

International audienc

Revealing 60 years of earthquake swarms in the Southern Red Sea, Afar and the Gulf of Aden

Earthquake swarms occur sporadically at divergent plate boundaries but their recurrence over multiple decades and relation to magmatic spreading activity remain poorly understood. Here we study more than 100 earthquake swarms over a 60-year period in the southern Red Sea, Afar, and Gulf of Aden region. We first compiled an earthquake-swarm catalogue by integrating reexamined global and local earthquake catalogues from 1960 to 2017. This yielded 134 earthquake swarms that mainly cluster in 19 different areas in the study region, showing that in most cases swarms recur every few decades in the same area. The swarms exhibit a range of earthquake magnitudes and often include multiple M3 to M5 events with some swarms having occasional larger earthquakes over M6, primarily in southern Afar. Many of the earthquake swarms were clearly associated with rifting events, consisting of magmatic intrusions, surface faulting, and in some cases volcanic eruptions. Together, the swarms suggest that extension at these divergent plate boundaries occurs episodically along <100 km long segments, some of which were previously unrecognized. Within the study region, the Gulf of Aden shows the most frequent swarm activity, followed by Afar and then the southern Red Sea. The results show that the three areas were subject to an increase of earthquake-swarm activity from 2003 to 2013 in the form of three rifting episodes and at least seven volcanic eruptions. We interpret that the most likely controls on temporal variations in earthquake swarm activity are either temporal variations in magma supply, or rifting-induced stress change that trigger clusters of swarms

Steady subsidence of a repeatedly erupting caldera through InSAR observations: Aso, Japan

The relation between unrest and eruption at calderas is still poorly understood. Aso caldera, Japan, shows minor episodic phreatomagmatic eruptions associated with steady subsidence. We analyse the deformation of Aso using SAR images from 1993 to 2011 and compare it with the eruptive activity. Although the dataset suffers from limitations (e.g. atmospheric effects, coherence loss, low signal-to-noise ratio), we observe a steady subsidence signal from 1996 to 1998, which suggests an overall contraction of a magmatic source below the caldera centre, from 4 to 5 km depth. We propose that the observed contraction may have been induced by the release of the magmatic fluids feeding the eruptions. If confirmed by further data, this hypothesis suggests that degassing processes play a crucial role in triggering minor eruptions within open conduit calderas, such as at Aso. Our study underlines the importance of defining any eruptive potential also from deflating magmatic systems with open conduit

New findings on compositionally distinct maar volcanoes: A case study from Acıgöl (Nevşehir) caldera (Central Anatolia, Turkey)

Recent experiments have largely reshaped our knowledge of maar volcanism. A new evolutionary model promoting the role of explosion depth and vent migration during the formation of maars has provided an alternative approach to previous models. Despite a few attempts to test this model with real cases, there is still a need for field-based studies exploring the depositional characteristics of maars to better understand the factors affecting the model constraints. More investigations on less known felsic maars are required to elucidate the possible differences from their more common mafic counterparts. Here, we explore compositionally distinct monogenetic clusters within the Acıgöl caldera (NW of Central Anatolian Volcanic Province, CAVP), with four felsic maars (İnallı, Kalecitepe, Acıgöl, and Korudağ) and one mafic maar (İcik). Our field observations reveal a successive formation between rhyolitic maars and adjacent lava domes. The mugearitic İcik coalescent maar and the adjacent scoria cone are synchronously formed, which is disclosed by the intercalation of the maar and scoria cone deposits. The geochemistry of the maar juveniles suggests a parental basaltic magma source that has been possibly differentiated by varying degrees of fractional crystallization. Our findings identify the main factors in maar formation (i.e., optimum scaled depth-OSD, water-magma interaction, and basement lithology). We also determine some differences between the felsic and mafic maars in the region, such as higher juvenile content, less amount of sedimentary structure, and a clear transition from phreatomagmatic to magmatic explosions through the end of stratigraphy. All these reflect the complexity of maars, mainly formed by different depths of explosions that occurred in the shallowest few hundred meters rather than a systematic incremental decrease of the eruption locus. Further geophysical and geochronological studies will complete our proposed evolutionary model for the youngest monogenetic activity in the Acıgöl caldera that would also warrant volcanic hazard assessment due to the presence of low-velocity anomalies, shallow Curie depths, and prevalent geothermal activity.</p

What controls the shallow structure of divergent plate boundaries? Insights from field and modelling data

The interest in the role of magma in splitting plates at divergent plate boundaries through discrete rifting episodes has been re-invigorated. However, despite the renewed enthusiasm for this topic, the precise mechanism by which the magma affects the geometry, the kinematics, and the temporal evolution of a rift is still poorly understood. Here we address several of the related issues, focusing on the surface deformation along plate boundaries, and then comparing the observed deformation with the results of analogue models on dike intrusion. We investigated surface deformation at divergent plate boundaries via field surveys in the Neovolcanic Zone of Iceland and the Main Ethiopian Rift, with focus on: 1) single eruptive fissures (Laki and Eldgjá, South Iceland), 2) mature rifts where several diking events have occurred comparatively recently (i.e. Sveinagjá and Krafla in North Iceland and Fantale in Ethiopia) and 3) on fissure swarms where strike-slip component is also present (Vogar and Þingvellir swarms, Southwest Iceland). Systematic measurements of fault and extension-fracture geometries and kinematics were carried out, including the analysis of the morphology of the fault terminations as possible indicators of the propagation direction of the faults. In addition, we conducted measurements across the fossil Álftafjörður dyke swarm, of late Tertiary age, in East Iceland, exposed at a depth of about 1.2 km below the original surface of the rift zone within which the dikes were emplaced. We use this dataset to calculate the crustal dilation due to diking and faulting at depth at 1-2 km. Analogue models are used as a complementary tools to aid understanding of the geometry and the kinematics of dike-induced structures, under systematically varied boundary conditions (intrusion depth, number of dikes per unit length of profile, etc). Laser-scanner and Particle Image Velocimetry (PIV) techniques were used to quantify the surface deformation in the analogue models and to reconstruct the time evolution of the rift-zone development. The field and analogue results make it possible to provide a general model which considers the role of tectonics and magma (diking) in the development of the axial part of divergent plate boundaries