rupture duration
Recently Published Documents


TOTAL DOCUMENTS

25
(FIVE YEARS 10)

H-INDEX

5
(FIVE YEARS 2)

2021 ◽  
Vol 118 (25) ◽  
pp. e2107770118
Author(s):  
Natalie Y. Chen ◽  
Paul H. Kim ◽  
Yiping Tu ◽  
Ye Yang ◽  
Patrick J. Heizer ◽  
...  

Defects or deficiencies in nuclear lamins cause pathology in many cell types, and recent studies have implicated nuclear membrane (NM) ruptures as a cause of cell toxicity. We previously observed NM ruptures and progressive cell death in the developing brain of lamin B1–deficient mouse embryos. We also observed frequent NM ruptures and DNA damage in nuclear lamin–deficient fibroblasts. Factors modulating susceptibility to NM ruptures remain unclear, but we noted low levels of LAP2β, a chromatin-binding inner NM protein, in fibroblasts with NM ruptures. Here, we explored the apparent link between LAP2β and NM ruptures in nuclear lamin–deficient neurons and fibroblasts, and we tested whether manipulating LAP2β expression levels would alter NM rupture frequency. In cortical plate neurons of lamin B1–deficient embryos, we observed a strong correlation between low LAP2β levels and NM ruptures. We also found low LAP2β levels and frequent NM ruptures in neurons of cultured Lmnb1−/− neurospheres. Reducing LAP2β expression in Lmnb1−/− neurons with an siRNA markedly increased the NM rupture frequency (without affecting NM rupture duration), whereas increased LAP2β expression eliminated NM ruptures and reduced DNA damage. Consistent findings were observed in nuclear lamin–deficient fibroblasts. Reduced LAP2β expression increased NM ruptures, whereas increased LAP2β expression virtually abolished NM ruptures. Increased LAP2β expression nearly abolished NM ruptures in cells subjected to mechanical stress (an intervention that increases NM ruptures). Our studies showed that increasing LAP2β expression bolsters NM integrity in nuclear lamin–deficient cells and markedly reduces NM rupture frequency.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Leili Yekefallah ◽  
Peyman Namdar ◽  
Leila Dehghankar ◽  
Fereshteh Golestaneh ◽  
Soghra Taheri ◽  
...  

Abstract Background Yoga can reduce the risk of preterm delivery, cesarean section (CS), and fetal death. The aim of the present study was to investigate the effects of Yoga on pregnancy, delivery, and neonatal outcomes. Methods This was a clinical trial study and using the random sampling without replacement 70 pregnant women entered Hatha Yoga and control groups according to the color of the ball they took from a bag containing two balls (blue or red). The data collection tool was a questionnaire pregnancy, delivery, and neonatal outcomes. The intervention in this study included pregnancy Hatha Yoga exercises that first session of pregnancy Yoga started from the 26th week and samples attended the last session in the 37th week. They exercised Yoga twice a week (each session lasting 75 min) in a Yoga specialized sports club. The control group received the routine prenatal care that all pregnant women receive. Results The results showed that yoga reduced the induction of labor, the episiotomy rupture, duration of labor, also had a significant effect on normal birth weight and delivery at the appropriate gestational age. There were significant differences between the first and second Apgar scores of the infants. Conclusion The results of the present study showed that Yoga can improve the outcomes of pregnancy and childbirth. They can be used as part of the care protocol along with childbirth preparation classes to reduce the complications of pregnancy and childbirth. Trial registration IRCT20180623040197N2 (2019-02-11).


2021 ◽  
Author(s):  
Mathieu Causse

<p>Here, I use seismological observations (~70 broadband stations at distances between 100 and 400 km from the source) to characterize the rupture properties of the Petrinja mainshock (Mw 6.4). First, I perform a spectral analysis of the P-waves to compute the corner frequency. In order to remove the wave propagation effects and isolate the source properties, I use the largest foreshocks and aftershocks (Mw>4) as empirical Green’s functions (EGFs). Assuming a Brune’s source model, the obtained stress drop is ~20 MPa. This rather large value is in agreement with the short rupture length of ~8 km inferred by InSAR data (Ganas et al. 2021). In addition, the weak azimuthal variations of the corner frequencies indicates a bilateral rupture, that is a rupture nucleating close to the fault center. Second, I compute the apparent source time functions (i.e. the source time functions “seen” from any station) using an EGF deconvolution approach. The results indicate an average rupture duration of 5-6 s with weak azimuthal variation of the apparent rupture duration, in agreement with the spectral analysis. Finally, I perform a Bayesian inversion of the apparent source function, in order to obtain a kinematic model of the rupture propagation (slip distribution, rupture velocity). The preliminary results reveal a slow velocity of the rupture propagation. Such a slow rupture velocity associated with a large stress drop has been observed on other faults with slow slip rates (e.g. Causse et al. 2017). This work provides insight on the rupture process of this major event on a poorly documented fault. I am fully open for collaborations to further develop and enrich this study.</p><p><br><strong>References</strong><br>Causse, M., G. Cultrera, L. Moreau, A. Herrero, E. Schiapappietra and F. Courboulex. Bayesian rupture imaging in a complex medium. The 29 May 2012 Emilia, Northern Italy, earthquake (2017), Geophysical Research Letters, DOI : 10.1002/2017GL074698.<br>Ganas, A., Elias, P., Valkaniotis, S., Tsironi, V., Karasante, I., Briole, P., 2021, Petrinja earthquake moved crust 10 feet, Temblor, http://doi.org/10.32858/temblor.156</p>


2021 ◽  
Author(s):  
Leili Yekefallah ◽  
Peyman Namdar ◽  
Leila dehghankar ◽  
Fereshteh Golestaneh4 ◽  
Soghra Taheri ◽  
...  

Abstract Background: yoga can reduce the risk of preterm delivery, cesarean section (CS), and fetal death. The aim of the present study was to investigate the effects of yoga on pregnancy, delivery, and neonatal outcomes. Methods: the random allocation method was used among 70 nulliparous women. The data collection tool was a questionnaire pregnancy, delivery, and neonatal outcomes. The intervention in this study was practicing hate yoga. Results: The results showed that yoga reduced the induction of labor, the episiotomy rupture, duration of labor, also had a significant effect on normal birth weight and delivery at the appropriate gestational age. There were significant differences between the first and second Apgar scores of the infants.Conclusion: The results of the present study showed that yoga can improve the outcomes of pregnancy and childbirth. they can be used as part of the care protocol along with childbirth preparation classes to reduce the complications of pregnancy and childbirth.Trial registration: IRCT20180623040197N2


2020 ◽  
Vol 110 (4) ◽  
pp. 1680-1687 ◽  
Author(s):  
Timothy I. Melbourne ◽  
Walter M. Szeliga ◽  
V. Marcelo Santillan ◽  
Craig W. Scrivner

ABSTRACT We have developed a global earthquake monitoring system based on low-latency measurements from more than 1000 existing Global Navigational Satellite System (GNSS) receivers, of which nine captured the 2019 Mw 6.4 Ridgecrest, California, foreshock and Mw 7.1 mainshock earthquakes. For the foreshock, coseismic offsets of up to 10 cm are resolvable on one station closest to the fault, but did not trigger automatic offset detection. For the mainshock, GNSS monitoring determined its coseismic deformation of up to 70 cm on nine nearby stations within 25 s of event nucleation. These 25 s comprise the fault rupture duration itself (roughly 10 s of peak moment release), another 10 s for seismic waves and displacement to propagate to nearby GNSS stations, and a few additional seconds for surface waves and other crustal reverberations to dissipate sufficiently such that coseismic offset estimation filters could reconverge. Latency between data acquisition in the Mojave Desert and positioning in Washington State averaged 1.4 s, a small fraction of the fault rupture time itself. GNSS position waveforms for the two closest stations that show the largest dynamic and static displacements agree well with postprocessed time series. Mainshock coseismic ground deformation estimated within 25 s of origin time also agrees well with, but is ∼10% smaller than, deformation estimated using 48 hr observation windows, which may reflect rapid postseismic fault creep or the cumulative effect of nearly 1000 aftershocks in the 48 hr following the mainshock. GNSS position waveform shapes, which comprise a superposition of dynamic and static displacements, are well modeled by frequency–wavenumber synthetics for the Hadley–Kanamori 1D crustal structure model and the U.S. Geological Survey finite-rupture distribution and timing. These results show that GNSS seismic monitoring performed as designed and offers a new means of rapidly characterizing large earthquakes globally.


2020 ◽  
Author(s):  
Mohammadreza Jamalreyhani ◽  
Pınar Büyükakpınar ◽  
Simone Cesca ◽  
Torsten Dahm ◽  
Henriette Sudhaus ◽  
...  

Abstract. The 24 January 2020 Mw 6.77 Elazığ-Sivrice earthquake (Turkey), responsible for 42 casualties and ~ 1600 injured people, is the largest earthquake affecting the East Anatolian Fault (EAF) since 1971. The earthquake partially ruptured a seismic gap. The mainshock was preceded by two foreshocks with Mw ≥ 4.9 and small seismicity clusters occurring in the previous months close to the nucleation point of the main rupture. The significant aftershock sequence comprises twelve earthquakes with Mw ≥ 4.5 within 60 days. We jointly model quasi co-seismic static surface displacements from Interferometric Synthetic Aperture Radar (InSAR) and high-frequency co-seismic data from seismological networks at local, regional and teleseismic distances to retrieve source parameters of the mainshock. We reconstruct the rupture process using a Bayesian bootstrap based probabilistic joint inversion scheme to obtain source parameters and their uncertainties. Full moment tensor for 18 fore-/after-shocks with Mw ≥ 4.3 are obtained based on the modeling of regional broadband data. The posterior mean model for the 2020 Elazığ-Sivrice mainshock shows that the earthquake, with a magnitude Mw 6.77, ruptured at shallow depth (5 ± 2 km) with a left-lateral strike-slip focal mechanism, with a dip angle of 74° ± 2° and a causative fault plane strike of 242° ± 1°, which is compatible with the orientation of the EAF at the centroid location. The rupture nucleated in the vicinity of small foreshock clusters and slowly propagated towards WSW, with a rupture velocity of ~ 2100 ± 130 m s−1 and ~ 27 s rupture duration. The main rupture area, with a length of ~ 26 ± 5 km, only covered 70 % of the former seismic gap, leaving a smaller, unbroken segment of ~ 30 km length to the SE with positive stress change. The subsequent aftershock sequence extended over a broader region of ~ 70 km in length, spreading to both sides of the mainshock rupture patch into the regions experiencing a stress increase according to our Coulomb stress modeling. Our results support the hypothesis of a shallow locking depth of the Anatolian micro-plate, which has a possible implication to the seismic bursts along the EAF and alternating seismic activity on the North Anatolian and the East Anatolian faults.


2019 ◽  
Vol 17 (1) ◽  
pp. 16
Author(s):  
Ramadhan Priadi ◽  
Angga Wijaya ◽  
Maria Annaluna Pasaribu ◽  
Riska Yulinda

September 28th, 2018, Donggala-Palu earthquake M 7.5 occurred at depth of 12 km and generated tsunami to be released off the coast in Palu Bay. The tsunami that occurred in Palu was very interesting because the results of the earthquake source mechanism Palu had a type of strike-slip fault that should not have generated a tsunami. This study purpose to estimate the characteristics of the Donggala-Palu tsunami based on rupture duration ( and orientation fault activated using the HC-plot method. The data used in this study are data waveforms from 17 seismic stations and CMT Global catalog data with the area of research 0.87 0 N-1.78 0S dan 118.640E- 120.95 0E. The waveform data used is a phase P-PP vertical component signal with a Bandpass-filter 1-5 Hz for determination . The fastest rupture duration from the earthquake source is obtained from the calculation of each station. Delay time measurement after P wave for 90% (T0.9), 80% (T0.8), 50% (T0.5), dan 20% (T0.2) from its peak value. Then the HC-plot method is used to estimate the orientation of generator fault Palu earthquake and the direction of rupture from the focal mechanism. From the results of processing obtained 2 pairs of seismic stations with almost the same distance but with different azimuths. The fastest rupture duration is at BBSI station with value of 82.014 s and distance from station to epicenter . So that the rupture direction is in the azimuth  from the north. The result of fault orientation was obtained hypocenter distance to the centroid for nodal plane 1 is 6.32 km and nodal plane 2 is 30.17 km with distance centroid to hypocenter is 31.22 km. So in Palu earthquake, the tsunami generator fault was in nodal plane 1 with direction north-south. Criteria obtained indicate that the Palu earthquake M 7.5 has potential for a tsunami because of its  value has meet  ≥ 65 s, but from the result of the focal mechanism direction field not passing through the Palu bay is thought to be another parameter that generates a tsunami and Palu koro fault line uncharted.


2019 ◽  
Vol 17 (1) ◽  
pp. 10
Author(s):  
Muhammad Fikri Haykal Hiola ◽  
A. Nasrurroh

Sulawesi is an area that has a high potential for tsunamis, especially in the North Sulawesi region due to the presence of a Pundungan Mayu subduction resulting from a double collision between the Maluku Sea plate and Halmahera and Sangihe arcs. Analysis of the duration rupture and estimated Mwp has been carried out using the P-wave phase in the North Sulawesi region as one of the tsunami early warning parameters. The data used were teleseismic body wave (300-900) from three earthquake-generating earthquakes with magnitudes above 7 (Sulawesi earthquake November 16, 2008, Celebes earthquake February 11, 2009, Molucca earthquake November 15, 2014) taken from the IRIS waveform catalog with 90 stations BHZ component registrar. The wave used is the P-PP wave phase (20% -90%) with a high frequency bandpass (1-2 Hz) butterworth filter. The results of the duration of the rupture obtained for the Sulawesi earthquake, Celebes earthquake, Molucca earthquake respectively 53.72 s, 52.98 s, 52.50 s. Whereas for Mwp, it has conformity with Mw from the IRIS catalog. So it can be concluded that the tsunami-generating earthquake in Sulawesi has a duration of rupture greater than 50 s which can be categorized as tsunamigenic earthquake (> 50 s) and the use of Mwp can be applied. Keywords : rupture duration, tsunami, Northern Sulawesi, Mwp


2019 ◽  
Vol 5 (5) ◽  
pp. eaav2032 ◽  
Author(s):  
Diego Melgar ◽  
Gavin P. Hayes

Whether earthquakes of different sizes are distinguishable early in their rupture process is a subject of debate. Studies have shown that the frequency content of radiated seismic energy in the first seconds of earthquakes scales with magnitude, implying determinism. Other studies have shown that recordings of ground displacement from small to moderate-sized earthquakes are indistinguishable, implying a universal early rupture process. Regardless of how earthquakes start, events of different sizes must be distinguishable at some point. If that difference occurs before the rupture duration of the smaller event, this implies some level of determinism. We show through analysis of a database of source time functions and near-source displacement records that, after an initiation phase, ruptures of M7 to M9 earthquakes organize into a slip pulse, the kinematic properties of which scale with magnitude. Hence, early in the rupture process—after about 10 s—large and very large earthquakes can be distinguished.


Sign in / Sign up

Export Citation Format

Share Document