214 research outputs found
Coseismic deformation and source modeling of the May 2012 Emilia (Northern Italy) earthquakes
On May 20th, 2012, an ML 5.9 earthquake (Table 1) occurred near the town of Finale Emilia, in the Central Po Plain, Northern Italy (Figure 1). The mainshock caused 7 casualties and the collapse of several historical buildings and industrial sheds. The earthquake sequence continued with diminishing aftershock magnitudes until May 29th, when an ML 5.8 earthquake occurred near the town of Mirandola, ~12 km WSW of the mainshock (Scognamiglio et al., 2012). This second mainshock started a new aftershock sequence in this area, and increased structural damage and collapses, causing 19 more casualties and increasing to 15.000 the number of evacuees.
Shortly after the first mainshock, the Department of Civil Protection (DPC) activated the Italian Space Agency (ASI), which provided post-seismic SAR Interferometry data coverage with all 4 COSMO-SkyMed SAR satellites. Within the next two weeks, several SAR Interferometry (InSAR) image pairs were processed by the INGV-SIGRIS system (Salvi et al., 2012), to generate displacement maps and preliminary source models for the emergency management. These results included continuous GPS site displacement data, from private and public sources, located in and around the epicentral area.
In this paper we present the results of the geodetic data modeling, identifying two main fault planes for the Emilia seismic sequence and computing the corresponding slip distributions. We discuss the implication of this seismic sequence on the activity of the frontal part of the Northern Apennine accretionary wedge by comparing the co-seismic data with the long term (geological) and present day (GPS) velocity fields.Published645-6551.1. TTC - Monitoraggio sismico del territorio nazionale1.9. Rete GPS nazionale1.10. TTC - Telerilevamento3.2. Tettonica attivaJCR Journalrestricte
Interseismic ground velocities in Central Apennines from GPS and InSAR measurements: new contributions for seismic hazard models by preliminary results of ESA CHARMING project
The contribution of space geodetic techniques to interseismic velocity estimation, and thus seismic hazard
modelling, has been recognized since two decades and made possible in more recent years by the increased availability
and accuracy of geodetic measurements. We present the preliminary results of a feasibility study performed within the
CHARMING project (Constraining Seismic Hazard Models with InSAR and GPS), funded by the European Space Agency
(ESA). For a 200 km x 200 km study area, covering the Abruzzi region (central Italy) we measure the mean surface
deformation rates from Synthetic Aperture Radar and GPS, finding several local to regional deformation gradients
consistent with the tectonic context. We then use a kinematic finite element model to derive the long-term strain rates, as
well as earthquake recurrence relations. In turn these are input to state-of-the-art probabilistic seismic hazard models, the
output of which is validated statistically using data from the Italian national accelerometric and macroseismic intensity
databases.Published373-3773T. Pericolosità sismica e contributo alla definizione del rischioN/A or not JCRope
Activation of the SIGRIS monitoring system for ground deformation mapping during the Emilia 2012 seismic sequence, using COSMO-SkyMed InSAR data
On May 20, 2012, at 02:03 UTC, a moderate earthquake
of local magnitude, ML 5.9 started a seismic sequence in the
central Po Plain of northern Italy (Figure 1) [Scognamiglio
et al. 2012, this volume]. The mainshock occurred in an area
where seismicity of comparable magnitude has neither been
recorded nor reported in the historical record over the last
1,000 years [Rovida et al. 2011].
The aftershock sequence evolved rapidly near the epicenter,
with diminishing magnitudes until May 29, 2012,
when at 07:00 UTC a large earthquake of ML 5.8 occurred
12 km WSW of the mainshock, starting a new seismic sequence
in the western area (Figure 1); a total of seven earthquakes
with ML >5 occurred in the area between May 20 and
June 3, 2012 (Figure 1). The details of the seismic sequence
can be found in the report by Scognamiglio et al. [2012].
Immediately after the mainshock, the Italian Department
of Civil Protection (Dipartimento di Protezione
Civile; DPC) requested the Italian Space Agency (Agenzia
Spaziale Italiana; ASI) to activate the Constellation of Small
Satellites for Mediterranean Basin Observation (COSMOSkyMed)
to provide Interferometric Synthetic Aperture
Radar (InSAR) coverage of the area. COSMO-SkyMed consists
of four satellites in a 16-day repeat-pass cycle, with
each carrying the same SAR payload [Italian Space Agency
2007]. In the current orbital configuration, within each 16-
day cycle, image pairs with temporal baselines of 1, 3, 4 and
8 days can be formed from the images acquired by the four
different sensors. Combined with the availability of a wide
range of electronically steered antenna beams with incidence
angles ranging from about 16° to 50° at near-range
[E-geos 2012], this capability allows trade-offs between temporal
and spatial coverage to be exploited during acquisition
planning.
A joint team involving the Istituto Nazionale di Geofisica
e Vulcanologia (INGV; National Institute of Geophysics
and Volcanology) and the Istituto per il Rilevamento
Elettromagnetico dell'Ambiente (IREA-CNR; Institute for
the Electromagnetic Sensing of the Environment) was activated
to generate InSAR-based scientific products to support
the emergency management. In this framework, the
ASI and DPC requested that INGV activated the Spacebased
Monitoring System for Seismic Risk Management
(SIGRIS) [Salvi et al. 2010]. SIGRIS consists of a hardware/
software infrastructure that is designed to provide the
DPC with value-added information products in the different
phases of the seismic cycle. During earthquake emergencies,
its goal is to rapidly provide decision-support
products, such as validated ground-displacement maps and
seismic source models.
This study reports the details of the activation of the
SIGRIS system in the case of the Emilia sequence. It provides
a description of the COSMO-SkyMed datasets and processing
procedures, as well as selected interferometric results for
the coseismic and post-seismic ground deformation. Fault
modeling results for the seismic sources of the largest earthquakes,
and a more detailed discussion of the observed
ground deformations are reported in Pezzo et al. [2012]
Mid-term review results of the ESA STSE Pathfinder CHARMING project (Constraining Seismic Hazard Models with InSAR and GPS)
We probe the feasibility of integrating GPS and
Synthetic Aperture Radar deformation rates within the
seismic hazard models of the central Apennines (Italy),
exploiting data from over 100 GPS stations and the ~20-
year long ERS and ENVISAT SAR image archive. We
then use a kinematic finite element model to derive the
long-term strain rates, as well as earthquake recurrence
relations. In turn these are input to state-of-the-art
probabilistic seismic hazard models, the output of which
is validated statistically using data from the Italian
national accelerometric and macroseismic intensity
databases.Published23-273T. Pericolosità sismica e contributo alla definizione del rischioN/A or not JCRrestricte
A multiresolution approach to automated classification of protein subcellular location images
<p>Abstract</p> <p>Background</p> <p>Fluorescence microscopy is widely used to determine the subcellular location of proteins. Efforts to determine location on a proteome-wide basis create a need for automated methods to analyze the resulting images. Over the past ten years, the feasibility of using machine learning methods to recognize all major subcellular location patterns has been convincingly demonstrated, using diverse feature sets and classifiers. On a well-studied data set of 2D HeLa single-cell images, the best performance to date, 91.5%, was obtained by including a set of multiresolution features. This demonstrates the value of multiresolution approaches to this important problem.</p> <p>Results</p> <p>We report here a novel approach for the classification of subcellular location patterns by classifying in multiresolution subspaces. Our system is able to work with any feature set and any classifier. It consists of multiresolution (MR) decomposition, followed by feature computation and classification in each MR subspace, yielding local decisions that are then combined into a global decision. With 26 texture features alone and a neural network classifier, we obtained an increase in accuracy on the 2D HeLa data set to 95.3%.</p> <p>Conclusion</p> <p>We demonstrate that the space-frequency localized information in the multiresolution subspaces adds significantly to the discriminative power of the system. Moreover, we show that a vastly reduced set of features is sufficient, consisting of our novel modified Haralick texture features. Our proposed system is general, allowing for any combinations of sets of features and any combination of classifiers.</p
Matrix analysis of identifiability of some finite markov models
Methods developed by Bernbach [1966] and Millward [1969] permit increased generality in analyses of identifiability. Matrix equations are presented that solve part of the identifiability problem for a class of Markov models. Results of several earlier analyses are shown to involve special cases of the equations developed here. And it is shown that a general four-state chain has the same parameter space as an all-or-none model if and only if its representation with an observable absorbing state is lumpable into a Markov chain with three states.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45730/1/11336_2005_Article_BF02291365.pd
The Multicultural Classroom as a Comparative Law Site: A United Kingdom Perspective
This chapter studies the impact of the recent multicultural approach to comparative legal studies on comparative law teaching, with a focus on British debates and literature. I will argue that the multicultural turn of (comparative) legal teaching, reflected for example in a greater diversity of teaching techniques, a greater emphasis on minority issues and law &… disciplines, responds to a multiplicity of motivations. Pedagogically, it is a response to the increasingly diverse backgrounds of students and their differing intellectual starting-points. Pragmatically, it is a means to boost students’ employability and intellectual versality in a job market that now values “cultural awareness skills”. Finally, conceptually, it is a tool designed to unravel the pluralistic nature of law. From these diverse drivers to the multicultural turn in (comparative) legal teaching, it is possible to identify similarities with other recent trends of globalisation and internationalisation of legal education. However, this article will submit that differences remain. Having analysed these differences, I will go on to argue and reveal that in them lie the core features of a multicultural approach to legal teaching and its intrinsic connections to comparative law, as the multicultural classroom itself becomes a comparative law site
Surprisingly Simple Mechanical Behavior of a Complex Embryonic Tissue
Background: Previous studies suggest that mechanical feedback could coordinate morphogenetic events in embryos. Furthermore, embryonic tissues have complex structure and composition and undergo large deformations during morphogenesis. Hence we expect highly non-linear and loading-rate dependent tissue mechanical properties in embryos. Methodology/Principal Findings: We used micro-aspiration to test whether a simple linear viscoelastic model was sufficient to describe the mechanical behavior of gastrula stage Xenopus laevis embryonic tissue in vivo. We tested whether these embryonic tissues change their mechanical properties in response to mechanical stimuli but found no evidence of changes in the viscoelastic properties of the tissue in response to stress or stress application rate. We used this model to test hypotheses about the pattern of force generation during electrically induced tissue contractions. The dependence of contractions on suction pressure was most consistent with apical tension, and was inconsistent with isotropic contraction. Finally, stiffer clutches generated stronger contractions, suggesting that force generation and stiffness may be coupled in the embryo. Conclusions/Significance: The mechanical behavior of a complex, active embryonic tissue can be surprisingly well described by a simple linear viscoelastic model with power law creep compliance, even at high deformations. We found no evidence of mechanical feedback in this system. Together these results show that very simple mechanical models can be useful in describing embryo mechanics. © 2010 von Dassow et al
Heart Valve Tissue Engineering: Concepts, Approaches, Progress, and Challenges
Potential applications of tissue engineering in regenerative medicine range from structural tissues to organs with complex function. This review focuses on the engineering of heart valve tissue, a goal which involves a unique combination of biological, engineering, and technological hurdles. We emphasize basic concepts, approaches and methods, progress made, and remaining challenges. To provide a framework for understanding the enabling scientific principles, we first examine the elements and features of normal heart valve functional structure, biomechanics, development, maturation, remodeling, and response to injury. Following a discussion of the fundamental principles of tissue engineering applicable to heart valves, we examine three approaches to achieving the goal of an engineered tissue heart valve: (1) cell seeding of biodegradable synthetic scaffolds, (2) cell seeding of processed tissue scaffolds, and (3) in-vivo repopulation by circulating endogenous cells of implanted substrates without prior in-vitro cell seeding. Lastly, we analyze challenges to the field and suggest future directions for both preclinical and translational (clinical) studies that will be needed to address key regulatory issues for safety and efficacy of the application of tissue engineering and regenerative approaches to heart valves. Although modest progress has been made toward the goal of a clinically useful tissue engineered heart valve, further success and ultimate human benefit will be dependent upon advances in biodegradable polymers and other scaffolds, cellular manipulation, strategies for rebuilding the extracellular matrix, and techniques to characterize and potentially non-invasively assess the speed and quality of tissue healing and remodeling
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