bluuebunny/crossref_metadata_2025_split huggingface dataset:
Waveform modeling of strong-motion data for the Saguenay earthquake of 25 November 1988
Authors: Haddon R. A. W. 
Published: September 2021

Abstract
The magnitude 6.0 Saguenay earthquake of 25 November 1988, in Quebec, Canada, was one of the largest recorded in eastern North America (ENA) during the past 50 years, and it has provided important high-quality data for estimation of earthquake hazard in ENA. Ground motions for the event recorded by both Eastern Canadian Telemetered, and Strong Motion, Networks were anomalously large and unexpectedly rich in high-frequency energy, as compared with most other events having the same mb or moment magnitudes. Displacement waveforms derived from the eastern Canadian strong-motion acceleration data have been modeled in detail in an attempt to explain these anomalies. The modeling has provided strong evidence that the surface on which the faulting occurred is relatively long and narrow, with its long axis nearly horizontal and situated immediately above an internal crustal discontinuity that lies at a depth of about 30 km; the faulting process was essentially antiplane and unilateral, with the crack starting at the northwest end of the long axis and propagating in the negative strike direction towards the southeast; and slip durations at individual points on the fault were short (of the order of 0.2 sec) compared with the time taken for the crack to propagate from its starting point to the far end of the fault (about 2.5 sec in the model). The inferred short slip durations are consistent with the inferred fault geometry, and both are consistent with “normal” static and dynamic stress drops (i.e., within a factor of 2 of 100 bars). The narrow elongate fault geometry and associated short slip durations are responsible for the enhanced high-frequency radiation (as compared with “normal” events having the same seismic moment release). The associated spectra differ greatly from that of the Brune spectral model, with the former having at least two corner frequencies, whereas the latter has only one.
The unilateral fault propagation resulted in a strong azimuthal variation of waveform characteristics, with the largest amplitudes and shortest durations concentrated towards the south and southeast and the smallest amplitudes and longest durations in the opposite directions. As the majority of strong-motion instruments and closer ECTN stations were located within the former azimuthal range, the anomalous high-frequency content and large observed amplitudes are accentuated by the station distribution with respect to the directivity characteristics of the source. Another significant factor likely to have contributed to the observed peak amplitudes, at least in some instances, is an indicated superposition of direct waves from the source with reflections from the inferred mid-crustal discontinuity. Elongate source geometry and associated effects such as those described above may not be uncommon for large thrust intraplate earthquakes and may have significant design implications for critical structures such as nuclear power plants.
Systematic difference in the ISC body-wave magnitude-seismic moment relationship between intermediate and deep earthquakes
Authors: Kuge Keiko 
Published: September 2021

Abstract
There exists a systematic difference in the ISC body-wave magnitude (mbISC) - seismic moment (M0) relationship between intermediate and deep earthquakes around Japan. For earthquakes with the same M0, the mbISC for intermediate events is larger than that for deep events by 0.2 to 0.3 units. The mbISC discrepancy is attributed to the depth-distance correction in the procedure for determining the mbISC; a larger depth-distance correction (≈ 0.2) is made for the intermediate events than the deep events, irrespective of station distance. The discrepancy disappears if no depth-distance correction is made. I observe no depth-dependent relationship between the M0 and the JMA magnitudes (MJMA), which make a different depth-distance correction. No significant depth-dependent mbISC discrepancy appears in other regions; for example, around Tonga, I observe larger ISC P-wave amplitudes from deep events than intermediate events, which could cancel the effect of the depth-distance correction. The depth-dependent mbISC - M0 relationship around Japan is observed irrespective of whether the magnitudes are determined using the amplitude data at far or near stations, or whether stations are used in the dipping direction of the slab or not. The mbISC discrepancy for the same M0 cannot arise from local structures, radiation patterns, and station coverages. This is not attributable to the dataset of the M0 itself because no significant depth-dependent relationship between M0 and MJMA is observed.
The role of elastic, undrained, and drained responses in triggering earthquakes at Monticello Reservoir, South Carolina
Authors: Rajendran Kusala , Talwani Pradeep 
Published: September 2021

Abstract
Following reservoir impoundment, stress changes occur due to elastic response and changes in pore pressure due to drained and undrained responses of the substratum. Elastic response may stabilize or destabilize the reservoir environment, depending on the nature of pre-existing stress field. However, the increase in pore pressure always leads to weakening of the rocks, facilitating the onset of seismicity. In most reservoirs, we usually observe the coupled poroelastic effect, and it is usually difficult to isolate individual contributions.
Due to the availability of detailed seismicity and geological and in situ stress data at Monticello Reservoir, it was possible to study various factors that control the mechanism of reservoir-induced seismicity. Our results suggest that, during the filling period, the instability resulted from elastic, undrained, and possibly onset of drained response. Subsequently, the seismicity showed a more consistent pattern associated with diffusion of pore pressure.
The shape of ground motion attenuation curves in southeastern Canada
Authors: Atkinson Gail M. , Mereu Robert F. 
Published: September 2021

AbstractThe shape of the attenuation curve of the Fourier spectrum of acceleration is established for southeastern Canada from empirical data. The dataset is comprised of 1200 digital vertical-component seismograms, from 100 earthquakes recorded on 30 stations of the Eastern Canada Telemetered Network. The distance range of the observations is 10 to 1700 km; focal depths are from 5 to 30 km.Results indicate that the attenuation curve has three distinct sections. At distances less than 70 km, corresponding to attenuation of the direct wave, amplitudes decay slightly more rapidly than 1/R (R−1.1). Between 70 and 130 km, where the direct wave is joined by SmS, spectral amplitudes are approximately constant. Beyond 130 km, corresponding to the Lg phase, amplitudes decay at a rate that is consistent with R−0.5 and Q = 670 f0.33. The findings support the hypothesis of Burger et al. (1987), that postcritical reflections from the Moho discontinuity play an important role in determining the shape of the attenuation curve. However, the influence of SmS is subtle, allowing the shape to be approximated by simple functional forms. For example, the commonly assumed bilinear form (R−1, R−0.5, with frequency-dependent Q) fits well if the transition from direct wave to Lg spreading is placed at approximately 60 km. A linear form (R−1 over all distances, with constant Q = 2000) also provides a satisfactory fit overall. We find little evidence for the dependence of attenuation on focal depth or tectonic province.
T-phase data and regional tsunamigenesis in Japan
Authors: Hiyoshi Yoshihisa , Walker Daniel A. , McCreery Charles S. 
Published: September 2021

Abstract
Good correlations are found between T-phase spectral strengths and seismic moments for large earthquakes off the coasts of northern and central Honshu, Japan. Also, earthquakes from these areas which generated regional tsunamis in Japan have larger seismic moments and T-phase spectral strengths over the frequency range of 10 to 35 Hz than nontsunamigenic earthquakes with similar source locations. These findings are consistent with earlier observations of T phases from tsunamigenic and nontsunamigenic earthquakes near Alaska and the Aleutian Islands (Walker et al., 1992) and suggest that T-phase data may be useful in improving the reliability of tsunami warning systems.
Seismic velocity structure and event relocation in Kazakhstan from secondary P phases
Authors: Quin H. R. , Thurber C. H. 
Published: September 2021

Abstract
Three-component seismic data from a set of presumed explosions recorded by stations at Bayanaul and Karkaralinsk in Kazakhstan were analyzed in order to model the crustal structure of the region and to examine the use of the arrival times of secondary P phases, primarily PmP, in regional event location. Polarization analysis aided in the identification of the secondary phases. Low-pass filtered data (4-Hz corner) from the first 5 to 10 sec of 13 presumed explosions were modeled with the reflectivity method. The two chemical explosions in 1987 provided a check on accuracy, as their locations and origin times are accurately known. A good fit to the arrival times and amplitudes in the first 5 sec of the P wave (Pn, Pg, and PmP) was obtained in the epicentral distance range of 100 to 300 km. Beyond 300 km, the simple layered model was not adequate to model the PmP arrival.
The crustal P-wave velocity model we derived has an upper crustal velocity increasing fairly rapidly from 4.5 km/sec near the surface to 6.5 km/sec at 15-km depth, then increasing more slowly to 7.05 km/sec at 50-km depth. The observed difference in the arrival times of the phases Pg, PmP, and Pn in the range between 100- and 250-km distance required a relatively sharp transition at the crust mantle boundary. The model is generally similar to previous estimates of P velocity structure in the region, though with a gentler gradient in the upper crust and a steeper gradient in the lower crust. We used the derived crustal model and the primary and secondary P-wave arrival times to relocate events in the Kazakhstan region. Inclusion of the phase PmP substantially decreases the focal depth uncertainty for many of the events. All but one of the events analyzed are concluded to be surface explosions; the identity of the remaining event is uncertain.
Impact of broadband seismology on the understanding of strong motions
Authors: Helmberger Don , Dreger Douglas , Stead Richard , Kanamori Hiroo 
Published: September 2021

Abstract
Most analyses of strong motion attenuation assume simple whole-space type geometrical spreading, namely (1/R) or its modified form e−kR/R. However, broadband data presently becoming available suggests a more complex behavior with substantial crustal effects. Events such as the Sierra Madre event, M = 5.8, triggered the strong motion channels at all of the TERRAscope stations allowing for 0.01-sec sampling of the wavefield. We find that most of the well-defined crustal bodywave arrivals defined and modeled in the 1 to 0.1-hz bandpass also contain high-frequency energy. By comparing the triggered channels with the continuous channels we see that several of the more distant stations triggered on the depth phase sPmP. These phases as well as the depth phase sSmS are obvious in velocity and quite apparent in accelerations. Our best models for Southern California contain a relatively thick low-velocity layer at the surface, roughly 5 km thick with shear velocities below 3 km/sec. This layer or zone, because it appears to vary considerably, controls the wavefield at nearly all frequencies out to about 60 km and yields attenuation decay faster than (1/R). At large ranges the lower crustal triplications dominate and the attenuation curve flattens. Adding random scatters to these layered models adds additional complexity but does not alter the basic flat-layer predictions.
A relative magnitude model for measurements of Soviet underground nuclear explosions from regional stations
Authors: Anderson Kevin K. , Nicholson Wesley L. 
Published: September 2021

Abstract
Recent research has shown the stability of root-mean-square Lg measurements for the accurate estimation of yields of Soviet underground nuclear explosions. Hansen, Ringdal, and Richards (1990) presented log-rms Lg data for 16 well-recorded Soviet underground nuclear explosions from eight seismic stations in Norway, the USSR, and China and a worldwide mb measurement for the same events. These data were analyzed using a relative magnitude model in which the parameters represent relative or normalized versions of the station intercepts, slopes and log-yields from the usual seismic magnitude / yield relationship. These normalized parameters are estimable without yield data and are simple transformations of the actual station intercepts, station slopes, and log-yields.
Relative magnitude modeling permits comparisons of the seismic magnitude / yield relationships of the individual stations and the worldwide mb measurements without yield data. The slope at the China Digital Seismograph Network station Hailar was found to be significantly different from that of the other stations in the study. The residual analysis estimated the precision of the log-rms Lg measurements of well-recorded explosions to be 0.0279 in magnitude units, which is in agreement with the findings of Hansen, Ringdal, and Richards (1990).
On the decoupling of surficial sediments from surrounding geology at Mexico City
Authors: Bard Pierre-Yves , Chávez-García Francisco J. 
Published: September 2021

Abstract
The geotechnical conditions at Mexico City suggest strongly the idea of decoupling the vertical resonance of the thin, very soft, clay layer at the surface, from the two-dimensional (2-D) effects of a much stiffer underlying sedimentary valley. The purpose of this paper is to explore whether numerical modeling supports this idea. This problem has also a bearing on the contradiction between the extent of local models usually assumed by seismologists and those considered by geotechnical engineers. We present results of 1-D models and of two different approaches to a 2-D modeling in an effort to explore the extent of local geology that must be considered in evaluating site effects at Mexico City. Our results indicate that there is a significant degree of coupling between the surficial clay layer and the underlying sediments, despite the extremely large impedance contrast. As a consequence, a full 1-D analysis gives better results than a 2-D “decoupled” one. It is also shown that deeper layers affect significantly ground motion at the surface. Thus, a simplified 1-D model that would consider only the uppermost very soft layers would be wrong in its prediction of surface motion by a factor about 3 both in frequency and time domains.
A systematic review of autopsy findings in COVID 19: The road ahead
Authors: Faizal Felice , Kapoor Umesh , Nambiar Balachandra 
Published: September 2021

Autopsy data on the COVID 19 is scarce and has left a gap in understanding the disease process. This study attempts to review the available data gleamed from the limited autopsies performed worldwide which would help in guiding future treatment protocols.A literature search was undertaken using PubMed, Scopus, Embase and Google search engines for original and review articles. Studies that mentioned autopsy and COVID-19 were included. Findings from a total of 16 studies mentioning 139 autopsies in confirmed cases of COVID 19 were analysed. The most common features in fatal cases has been cough followed by progressive dyspnoea. Fatal cases show a predominance in the elderly age group, male gender and individuals with blood type A.Autopsy findings in various organs have been described with the prominent feature being Diffuse alveolar damage and microthrombii formation in the lung. Massive pulmonary embolism and Deep vein thrombosis seem to be overlooked features in the fatal cases.Complement mediated destruction is a potential pathogenetic mechanism suggested by C4d and C5b-9 deposition in the skin lesions and lung capillaries.To conclude, Prophylactic dose of low molecular weight heparin, chest CT and serial D-dimer levels are recommended in all patients with suspected COVID 19 admitted to the hospital.The demonstration of complement mediated injury to various tissues also suggest a role of anti-complement therapy to improve patient outcomes.Detailed autopsy studies are required to evaluate the pathology of COVID 19 in various organs to understand the disease process better
Prognostic significance of immunohistochemical markers in Primary CNS lymphomas
Authors: Ramachandran Nair Indu , Phalak Pooja , Mangalath Rajamma Bindhu , Pradeep Aiswarya , Retnathankom Ayyadurai , M Jose Wesley 
Published: September 2021

Primary CNS lymphoma (PCNSL) is a rare form of extra nodal Non-Hodgkin Lymphoma that is typically conﬁned to the brain, spinal cord, lepto meninges and eyes. We studied the clinico pathological features of PCNSLs, immuno histochemical (IHC) markers expressed and the association of morphological features & IHC markers with clinical outcome. 30 cases of primary CNS lymphomas were studied. 25 cases were diffuse large B cell lymphomas, which were sub classified using Hans algorithm into GCB and non-GCB. The IHC markers done were CD20, CD3, BCL2, BCL6, MUM-1, CD10 and c-myc. Mean proliferation index Ki was 80%. Follow up and survival data was collected and the association of each IHC marker and subtype with prognosis was assessed. PCNSL forms around 2% of all lymphomas as well as primary CNS tumours. Non GCB type is more common (72%). Mean overall survival was 9.7 months. Ki-67 index of 80% or more is the only independent variable of prognostic significance. None of the other IHC markers or sub typing had any influence on the outcome.
Observational study on serum markers and circulating tumor cells in ovarian cancer
Authors: Jaiswal Riddhi , Tripathi Piyush , Venkatesh Vimala , Gupta Pravesh 
Published: September 2021

1) To detect Cyclophilin, APC and SFRP5 genes associated with Epithelial ovarian cancer by PCR. 2) To study and compare the prognostic and diagnostic efficacy of serological markers like Ca 125 and HE4 and their correlation with epithelial/ non epithelial ovarian neoplasms.Comparative observational study, Prospective study 64 cases fulfilling the inclusion criteria and giving their consent for inclusion in the study were enrolled as subjects of the present study over a period of one year. After DNA extraction (Invitrogen mini kit, USA) conventional PCR to amplify the extracted DNA and further subjected them to agarose gel electrophoresis for the identification(expression) of 3 genes i.e Cyclophillin, APC and SFRP5, was done; However, none expressed.ELISA was used to assess CA125 and HE4 pre and post surgical intervention. The serum markers were raised more in malignant epithelial ovarian cancer cases and levels plummeted after surgical intervention, as compared to benign masses. We could not establish correlation of the genes’ expression with the serum markers and histopathology. Combining HE4 and CA125 both might be more helpful than either of them using alone, in diagnosing as well as prognosticating ovarian diseases. A panel of multiple genes on a larger sample size may be needed for CTC detection.Early detection of ovarian tumors leads to early diagnosis and hence early institution of intervention and hence decreased morbidity and mortality.
Women’s Preference for Cosmesis of Incisions Used for Open Versus Robotic Lower Urinary Tract Reconstructive Surgery
Authors: Hina Dr Saddaf , Alhasso Ammar , Granitsiotis Paraskeve 
Published: September 2021

OBJECTIVE: To compare the cosmetic appeal of incisions used for open (Pfannenstiel or Vertical midline) versus robotic-assisted laparoscopic lower urinary tract reconstructive surgery in women.
STUDY DESIGN: Cross-sectional descriptive study
PLACE AND DURATION: Outpatient Urology Clinic of Western General Hospital, Edinburgh Scotland, UK from 1st February 2019 till 28th February 2020.
METHODS: All patients were provided illustrations of Pfannenstiel incision (incision at “bikini line”- (A), Vertical midline laparotomy incision (incision from midline symphysis to umbilicus –( B), Robotic-assisted laparoscopic incisions-variation I- (C) and Robotic-assisted laparoscopic incisions-variation II (-D). Patients were asked to rate each incision in order of their preference. Chi square distribution was used to compare mean previous surgeries and no previous surgeries between different preferred incisional groups and ages of the patients.
RESULTS: One hundred patients with mean age were 53.11±15.05 years with minimum 19 years and maximum 84 years and mean BMI was 28.18±7.05 kg/m2 with minimum 15.6 and maximum 55 kg/m2 calculated. Out of 100 patients (1st preference of incision), 78% preferred incision A, 3% preferred B incision and 16% & 3% patients preferred incision C and D respectively. Similarly (2nd preference of incision) 3% patients preferred incision A, 19% preferred B incision and 56% & 22% patients preferred incision C and D respectively. The mean comparison between first preferred incision with second preferred incision with respect of surgeries (previous surgeries and no previous surgeries) showed significant difference p≤0.05 (chi value=167.692, p=0.000). Relation of preferred incisions with respect to ages of the patients showed no significant difference (Pearson relation value -0.182 and p=0.069).
CONCLUSION: Overall, open incisions were preferred over robotic incisions. Patient perception of the "visibility" of abdominal incisions and previous experience in term of surgical scars may be the distinguishing issue to explain the difference in the preferences between open versus robotic-assisted laparoscopic incisions in women.
“Comparing Locking Compression Plate with Limited Contact Dynamic Compression Plate For the Treatment of Adult Diaphyseal Both Bone Forearm Fractures”
Authors: Hossain Md. Akter , Misty Mahmuda Khan , Chanda Palash Kumar 
Published: September 2021

Introduction: The human forearm serves an important role in upper extremity function, facilitating placement of the hand in space, thus helping to provide the upper extremity with its unique mobility Fractures involving the bones of forearm present unique problem not encountered with fractures of other long bones.
Objective: To evaluate and compare the outcomes of locking compression plate (LCP) with limited contact dynamic compression plate (LC-DCP) for the treatment of adult diaphyseal both bone forearm fractures.
Material and Methods: This study conducted in the Department of orthopedics, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from January 2018 to December 2020 included 20 patients with 40 fractures in each group. Patients were selected randomly to receive either LCP (20 patients, 40 fractures) or LC-DCP (20 patients, 40 fractures). Operative time, callus formation, functional outcome and complications were recorded.
Results: Mean operative time did not differ significantly in the LCP and LC-DCP group (71.25 and 75.70 minutes respectively) .There was some difference in callus formation and mean time to bone union between the two groups which was significant. However, overall functional outcome did not differ significantly between both the groups. One case had delayed union in the (LC-DCP) group while one patient in each group developed superficial infection.
Conclusion: In this prospective study comparing LCP with LC-DCP, the outcomes were equal in terms of final functional outcomes and mean operating time but LCP showed slight advantage in terms of callus formation and mean time to bone union.