The preparatory phase of the Mw 6.1 2009 L’Aquila (Italy) normal faulting earthquake traced by foreshock time-lapse tomography

Geology ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Paola Baccheschi ◽  
Pasquale De Gori ◽  
Fabio Villani ◽  
Fabio Trippetta ◽  
Claudio Chiarabba

Abstract The Mw 6.1 (6 April 2009) L’Aquila (Italy) earthquake occurred in one of the most seismically active areas of central Italy and was preceded by a three-month-long foreshock period. Thanks to recordings by a regional permanent network, we derive for the first time P- and S-wave velocity tomographic models of a major fault prone to an imminent main shock. Close to the Mw 6.1 hypocenter, we observe high Vp (>6.8 km/s) and high Vp/Vs (>1.9) consistent with thick dolomitic volumes filled with fluids sealed by impermeable anhydritic layers. Significant changes in velocities defined by time-lapse imaging during the foreshock period suggest rapid fluid migration through the locked fault zone. The complex positive feedback between fluid pressure buildup and hydrofracturing of the dolomitic reservoir, testified by foreshock production, eventually provoked the catastrophic coseismic breaching of the fault seal. Our results show that foreshock time-lapse tomography provides clues on the preparatory phase of a large normal-faulting earthquake.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroaki Shimono ◽  
Atsushi Kaida ◽  
Hisao Homma ◽  
Hitomi Nojima ◽  
Yusuke Onozato ◽  
...  

AbstractIn this study, we examined the fluctuation in radioresponse of HeLa cells during the cell cycle. For this purpose, we used HeLa cells expressing two types of fluorescent ubiquitination-based cell cycle indicators (Fucci), HeLa-Fucci (CA)2 and HeLa-Fucci (SA), and combined this approach with the micronucleus (MN) assay to assess radioresponse. The Fucci system distinguishes cell cycle phases based on the colour of fluorescence and cell morphology under live conditions. Time-lapse imaging allowed us to further identify sub-positions within the G1 and S phases at the time of irradiation by two independent means, and to quantitate the number of MNs by following each cell through M phase until the next G1 phase. Notably, we found that radioresponse was low in late G1 phase, but rapidly increased in early S phase. It then decreased until late S phase and increased in G2 phase. For the first time, we demonstrated the unique fluctuation of radioresponse by the MN assay during the cell cycle in HeLa cells. We discuss the difference between previous clonogenic experiments using M phase-synchronised cell populations and ours, as well as the clinical implications of the present findings.


2011 ◽  
Vol 434 (3) ◽  
pp. 523-535 ◽  
Author(s):  
Marcus Fulde ◽  
Manfred Rohde ◽  
Angela Hitzmann ◽  
Klaus T. Preissner ◽  
D. Patric Nitsche-Schmitz ◽  
...  

Streptococcus canis is an important zoonotic pathogen capable of causing serious invasive diseases in domestic animals and humans. In the present paper we report the binding of human plasminogen to S. canis and the recruitment of proteolytically active plasmin on its surface. The binding receptor for plasminogen was identified as a novel M-like protein designated SCM (S. canis M-like protein). SPR (surface plasmon resonance) analyses, radioactive dot-blot analyses and heterologous expression on the surface of Streptococcus gordonii confirmed the plasminogen-binding capability of SCM. The binding domain was located within the N-terminus of SCM, which specifically bound to the C-terminal part of plasminogen (mini-plasminogen) comprising kringle domain 5 and the catalytic domain. In the presence of urokinase, SCM mediated plasminogen activation on the bacterial surface that was inhibited by serine protease inhibitors and lysine amino acid analogues. Surface-bound plasmin effectively degraded purified fibrinogen as well as fibrin clots, resulting in the dissolution of fibrin thrombi. Electron microscopic illustration and time-lapse imaging demonstrated bacterial transmigration through fibrinous thrombi. The present study has led, for the first time, to the identification of SCM as a novel receptor for (mini)-plasminogen mediating the fibrinolytic activity of S. canis.


Geophysics ◽  
2011 ◽  
Vol 76 (5) ◽  
pp. O23-O33 ◽  
Author(s):  
Tiziana Vanorio ◽  
Amos Nur ◽  
Yael Ebert

The fundamental concept of time-lapse seismic monitoring is that changes in physical parameters—such as saturation, pore fluid pressure, temperature, and stress—affect rock and fluid properties, which in turn alter the seismic velocity and density. Increasingly, however, time-lapse seismic monitoring is called upon to quantify subsurface changes due in part to chemical reactions between injected fluids and the host rocks. This study springs from a series of laboratory experiments and high-resolution images assessing the changes in microstructure, transport, and seismic properties of fluid-saturated sandstones and carbonates injected with [Formula: see text]. Results show that injecting [Formula: see text] into a brine-rock system induces chemo-mechanical mechanisms that permanently change the rock frame. Injecting [Formula: see text] into brine-saturated-sandstones induces salt precipitation primarily at grain contacts and within small pore throats. In rocks with porosity lower than 10%, salt precipitation reduces permeability and increases P- and S-wave velocities of the dry rock frame. On the other hand, injecting [Formula: see text]-rich water into micritic carbonates induces dissolution of the microcrystalline matrix, leading to porosity enhancement and chemo-mechanical compaction under pressure. In this situation, the elastic moduli of the dry rock frame decrease. The results in these two scenarios illustrate that the time-lapse seismic response of chemically stimulated systems cannot be modeled as a pure fluid-substitution problem. A first set of empirical relationships links the time-variant effects of injection to the elastic properties of the rock frame using laboratory velocity measurements and advanced imaging.


2019 ◽  
Vol 31 (12) ◽  
pp. 1851 ◽  
Author(s):  
Niamh Lewis ◽  
Karen Schnauffer ◽  
Katrin Hinrichs ◽  
Monica Morganti ◽  
Stephen Troup ◽  
...  

The use of time-lapse imaging (TLI) in the evaluation of morphokinetics associated with invitro developmental competence is well described for human, cattle and pig embryos. It is generally accepted that embryos that complete early cleavage sooner are more likely to form blastocysts and that timing of later events, such as blastocyst formation and expansion, are predictive of implantation potential and euploid status. In the horse, morphokinetics as a predictor of developmental competence has received little attention. In this study we evaluated the morphokinetics of early equine embryo development invitro for 144 oocytes after intracytoplasmic sperm injection and report the timings of blastocyst development associated with ongoing pregnancy for the first time. There was a tendency for time of cytoplasmic extrusion and first cleavage to occur earlier in the embryos that went on to form blastocysts (n=19) compared with those that arrested, and for first cleavage to occur earlier in blastocysts that established pregnancies that were ongoing (n=4) compared with pregnancies that were lost (n=2). TLI was clinically useful in identifying blastocysts when evaluation of morphology on static imaging was equivocal.


Acta Naturae ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 88-96
Author(s):  
Yu. K. Doronin ◽  
I. V. Senechkin ◽  
L. V. Hilkevich ◽  
M. A. Kurcer

In order to estimate the diversity of embryo cleavage relatives to embryo progress (blastocyst formation), time-lapse imaging data of preimplantation human embryo development were used. This retrospective study is focused on the topographic features and time parameters of the cleavages, with particular emphasis on the lengths of cleavage cycles and the genealogy of blastomeres in 2- to 8-cell human embryos. We have found that all 4-cell human embryos have four developmental variants that are based on the sequence of appearance and orientation of cleavage planes during embryo cleavage from 2 to 4 blastomeres. Each variant of cleavage shows a strong correlation with further developmental dynamics of the embryos (different cleavage cycle characteristics as well as lengths of blastomere cycles). An analysis of the sequence of human blastomere divisions allowed us to postulate that the effects of zygotic determinants are eliminated as a result of cleavage, and that, thereafter, blastomeres acquire the ability of own syntheses, regulation, polarization, formation of functional contacts, and, finally, of specific differentiation. This data on the early development of human embryos obtained using noninvasive methods complements and extend our understanding of the embryogenesis of eutherian mammals and may be applied in the practice of reproductive technologies.


2019 ◽  
Vol 1 ◽  
pp. 204-210 ◽  
Author(s):  
Alyson Wilson ◽  
Stanley Serafin ◽  
Dilan Seckiner ◽  
Rachel Berry ◽  
Xanthé Mallett

2021 ◽  
Vol 109 ◽  
pp. 103363
Author(s):  
Ben Roche ◽  
Jonathan M. Bull ◽  
Hector Marin-Moreno ◽  
Timothy G. Leighton ◽  
Ismael H. Falcon-Suarez ◽  
...  

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