bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of near-source static and dynamic measurements from the 1979 Imperial Valley earthquake
Authors: Archuleta Ralph J. 
Published: June 2021

abstractGross features of the rupture mechanism of the 1979 Imperial Valley earthquake (ML = 6.6) are inferred from qualitative analysis of near-source ground motion data and observed surface rupture. A lower bound on the event's seismic moment of 2.5 × 1025 dyne-cm is obtained by assuming that the average slip over the whole fault plane equals the average surface rupture, 40.5 cm. Far-field estimates of moment suggest an average slip over the fault plane of 105 cm, from which a static stress drop of 11 bars is obtained. An alternative slip model, consistent with the far-field moment, has 40.5 cm of slip in the upper 5 km of the fault and 120 cm of slip in the lower 5 km. This model suggests a static stress drop of 39 bars. From the lower estimate of 11 bars, an average strain drop of 32 µstrain is derived. This strain drop is four times greater than the strain that could have accumulated since the 1940 El Centro earthquake based on measured strain rates for the region. Hence, a major portion of the strain released in the 1979 main shock had been accumulated prior to 1940.Unusually large amplitude (500 to 600 cm/sec2) vertical accelerations were recorded at stations E05, E06, E07, E08, EDA of the EI Centro array, and the five stations of the differential array near EDA. Although the peak acceleration of 1705 cm/sec2 at E06 is probably amplified by a factor of 3 due to local site conditions, these large amplitude vertical accelerations are unusual in that they are evident on only a few stations, all of which are near the fault trace and at about the same epicentral range. Two possible explanations are considered: first, that they are due to a direct P wave generated from a region about 17 km north of the hypocenter, or second, that they are due to a PP phase that is unusually strong in the Imperial Valley due to the large P-wave velocity gradient in the upper 5 km of the Imperial Valley.Based on the distribution of both the horizontal and vertical offsets, it is likely that the rupture went beyond stations E06 and E07 during the main shock. By exploiting the antisymmetry of the parallel components of particle velocity between E06 and E07 and by examining polarization diagrams of the particle velocity at E06 and E07, an average rupture velocity in the basement of 2.5 to 2.6 km/sec between the hypocenter and station E06 is obtained. In addition, several lines of evidence suggest that the Imperial fault dips about 75° to the NE.
Finite faults and inverse theory with applications to the 1979 Imperial Valley earthquake
Authors: Olson Allen H. , Apsel Randy J. 
Published: June 2021

abstractUsing a representation theorem from elastodynamics, subsurface slip on a known fault is formulated as the solution to an inverse problem in which recorded surface ground motion is the data. Two methods of solution are presented: the least-squares method, which minimizes the squared differences between theory and data, and the constrained least-squares method which simultaneously maintains a set of linear inequalities. Instabilities in the solution are effectively eliminated in both methods, and the sensitivity of the solution to small changes in the data is quantitatively stated. The inversion methodology is applied to 77 components of near-field ground acceleration recorded during the 15 October 1979 Imperial Valley earthquake. The faulting is constrained to propagate bilaterally away from the epicenter at an average velocity of 90 per cent of the shear wave speed on a vertical fault plane extending from the surface to 10 km depth. Inequality constraints are used to keep the faulting sequence physically reasonable by maintaining right-lateral motion and positive slip velocity. The preferred solution is stable and provides a good fit to the data; it is also realistic and consistent with observed surface offsets and independent estimates of seismic moment
Broadband analysis of the extended foreshock sequence of the Miyagi-Oki earthquake of 12 June 1978
Authors: Choy George L. , Boatwright John 
Published: June 2021

abstract
The Miyagi-Oki earthquake of 12 June 1978, a large (Ms 7.8) interplate thrust event, occurred in a region which had not experienced earthquakes of magnitude greater than 7 since 1938. A sequence of four moderate-sized (5.4 &lt; mb &lt; 6.1) earthquakes encircled the rupture zone of the Miyagi-Oki earthquake over a period of 2 yr before the main shock. Broadband displacement and velocity records of body waves recorded digitally by stations of the Global Digital Seismograph Network are analyzed to determine the static and dynamic characteristics of the sequence. These characteristics include moment, radiated energy, dynamic and static stress drop, and apparent stress. Inversions of duration measurements made on the velocity waveforms permit quantifying the complexity of an event as well as constraining its rupture geometry.
Intervals of 7 to 8 months separated the first three events; the main shock occurred 4 months after the third event. The rupture process of the third event was relatively complex; the event also had a substantially higher dynamic stress drop (175 bars) than did the stress drops of the first two events (9 and 10 bars, respectively). These observations suggest that the third event was an interme-diate-term precursor to the main shock. The fourth event, a short-term precursor to the main shock, occurred about 8 min before the main shock. Its dynamic stress drop (20 bars) was lower than that of the third event but higher than that of the first two events.
The 1971 San Fernando earthquake: A double event?
Authors: Heaton Thomas H. 
Published: June 2021

abstractEvidence is presented which suggest that the 1971 San Fernando earthquake may have been a double event that occurred on two separate, subparallel thrust faults. It is postulated that the initial event took place at depth on the Sierra Madre fault zone which runs along the base of the San Gabriel Mountains. Rupture is postulated to have occurred from a depth of about 15 km to a depth of about 3 km. A second event is thought to have initiated about 4 sec later on another steeply dipping thrust fault which is located about 4 km south of the Sierra Madre fault zone. The surface trace of this fault coincides with the San Fernando fault zone which was the principal fault associated with surface rupture. It is postulated that rupture propagated from a depth of 8 km to the free surface. The moments of the first and second events are approximately 0.7 × 1026 dyne-cm and 1.0 × 1026 dyne-cm, respectively. This model is found to explain the combined data sets of strong ground motions, teleseismic P and S waveforms, and static offsets better than previous models, which consist of either a single fault plane or a plane having a dip angle which shallows with decreasing depth. Nevertheless, many features of the observed motions remain unexplained, and considerable uncertainty still exists regarding the faulting history of the San Fernando earthquake.
Tidal triggering of earthquakes
Authors: Heaton Thomas H. 
Published: June 2021

abstractAnalysis of the tidal stress tensor at the time of moderate to large earthquakes fails to confirm an earlier hypothesis that the origin times of shallow dip-slip earthquakes correlate with solid-earth tidal shear stress. Furthermore, no correlation is seen for either tidal shear stress or tidal normal-to-the-fault compressive stress with shallow strike-slip earthquakes or with deep earthquakes.
Assessment and comparison of clinico-microbiological efficacy of moxifloxacin plus vancomycin combined therapy with fortified vancomycin in bacterial keratitis
Authors: Abdullah Ahmad , Askari S N , Ahmad Shamim , Alvi Yasir 
Published: June 2021

To assess and compare clinico-microbiological efficacy of Moxifloxacin (0.5%) plus Vancomycin (2.5%) combined therapy to Fortified Vancomycin (5%) in bacterial keratitis.The present study was conducted on patients who visited eye OPD, J.N.M.C.H and Gandhi Eye Hospital, Aligarh. Patientsiwith bacterial keratitis were diagnosed and included in the study. Right eyes were instilled moxifloxacin plus vancomycin combination therapy and Left eyes were instilled fortified vancomycin. Microbiological results were recorded on first visit and on follow up visits during course of treatment.Total of 32 patients were included in the study. At first visit, only 8 cases were positive for bacterial culture with coagulase negative Staphylococcus (CoNS) being the most common organisms. All the smears became negative in first follow-up (7th day) in both the groups. No significant difference were found in clinical and microbiological study outcome betweenthe two-study groups.We conclude that both the drugs, i.e. moxifloxacin (0.5%) plus vancomycin (2.5%) combined therapy and fortified vancomycin (5%) had good efficiency clinically and in microbial elimination in cases of bacterial keratitis with equivalent outcome.
Comparative study on incidence of posterior vitreous detachment (PVD) between conventional and femtosecond laser-assisted laser in situ keratomileusis (LASIK)
Authors: Chaitanya S Ravi , Ravindran Meenakshi , Venugopal Anitha 
Published: June 2021

To compare incidence of posterior vitreous detachment (PVD) in patients after microkeratome and femtosecond laser-assisted laser in situ keratomileusis (LASIK) using ultrasound B-scan. Prospective, non-randomised, comparative and interventional hospital based study. This study was performed on 138 eyes of 69 patients, 64 eyes in microkeratome group and 74 eyes in femtosecond laser group for a period of 10 months from December 2017 to October 2018. The mean age of patients in microkeratome group was 23.34 years and in femtosecond laser group was 23.19 years. All patients in both the groups underwent one of the two procedure. Patients were assessed for subjective and objective refraction, presence of PVD, subjective complaints of floaters and axial length changes at each visit. At 1 week and 1 month postoperative period there was no PVD in either of the groups and none of the patients complained about disturbing floaters. At one week postoperative period, 17 eyes (26.5%) in microkeratome group and 22 eyes (29.6%) in femtosecond laser group had residual refraction ranging from -0.25D to -0.75D. The changes in axial length following surgery was 0.08 ± 0.08mm in microkeratome group and 0.1 ± 0.07mm in femtosecond laser group at one month. Our study did not demonstrate any difference between both the procedures with respect to posterior segment complications. Patients in our study are relatively younger compared to other studies and hence, age of the patient undergoing LASIK may affect the incidence of PVD.Both microkeratome assisted LASIK and femtosecond assisted LASIK were comparable with respect to posterior segment complications. The mean age of patients in this study is assumed to have an effect on outcome. Whereas axial length, power of the eye, procedure opted did not significantly have any impact on outcome. A larger population with longer follow up is needed in Indian population to conclude our results.
To evaluate effect of intraocular pressure control on central corneal thickness, horizontal corneal diameter and axial length in primary congenital glaucoma
Authors: Tank Gunjan P , Prajapati Kamini M , Bhatt Rupal , Chauhan Amita , Mansuri Mariam , Goel Nikita 
Published: June 2021

To evaluate the effect of intraocular pressure (IOP) on central corneal thickness (CCT), horizontal corneal diameter (HCD), axial length (AL) in patients with primary congenital glaucoma (PCG) after antiglaucoma surgery. In this hospital based interventional study 36 patients (66 eyes) of PCG who underwent antiglaucoma surgery were included in the study. For each patient visual acuity, anterior and posterior segment examination, IOP, AL, CCT, HCD and refraction (in clear media) were recorded pre and post operatively (3 weeks, 3 months, 6 months). B scan ultrasonography was done to measure AL and to rule out posterior segment pathology. Surgery was performed by a glaucoma expert (by a single surgeon). Bilateral involvement was present in 83.33% with the most common symptom being photophobia and watering (30.56% each). The mean IOP, CCT, HCD, VCD and AL before surgery were 26.88+/-2.78 mmHg, 614.38+/-89.41 µ, 14.41+/-1.26mm, 13.19+/-1.46mm and 24.78+/-2.21mm and at 6 months were 13.85+/-1.93 mmHg, 548.56+/-63.13 µ, 14.62+/-0.49 mm, 13.34+/-1.10 mm and 25.73+/-1.36mm respectively. 59.1% of the patients had corneal clearing at 6 months. Control of IOP affects various parameters of eye like CCT, HCD and AL. Early surgery is the definitive line of management for controlling IOP in PCG patients.
Etiological factors & microbiological characteristics of infectious keratitis in western Maharashtra
Authors: Mohan Madhuvanthi , Magdum Renu , Kaul Sucheta , Desai Chaitali , Cardoza Namratha Judith , Mohan Madhuvanthi 
Published: June 2021

To identify the etiological factors and study the microbiological characteristics of infectious keratitis in Western Maharashtra. This was a prospective observational hospital‐based study conducted at the Department of Ophthalmology, at a tertiary care hospital, in a part of central India. Data related to socioeconomic status and etiological factors was collected. Results were analyzed on the basis of history, slit lamp examination, microbiological scraping and culture results. During the period of September 2018 to August 2020, a total of 60 patients with infectious keratitis were examined in the Ophthalmology OPD. Majority of patients of infectious keratitis were between 61 and 70 (18.33%) age group. Incidence in male was higher (68%) than female. Ocular trauma was the most common etiological factor (52%). Prevalence of Fungal keratitis (52%) was higher than bacterial (46%) in this part of India. 57% subjects showed organism on Gram staining. 53% subjects showed KOH positivity. 68.3% showed growth over microbiological culture with the most common species isolated as Fusarium species (26.6%) followed by Pseudomonas aeruginosa. Incidence of fungal keratitis is higher in this part of Western Maharashtra. Most common etiological factor was determined to be trauma with vegetative matter among farmers which tells us that they are most prone for infectious keratitis. Prompt diagnosis, microbiological scraping, culture growth identification and starting on appropriate treatment can help reduce the morbidity of corneal ulcers.
Systemic co-morbidities in patients undergoing cataract surgery
Authors: Modak Swapnil N , Mishrikotkar Jyotika P , Thakre Snehal R , Gadekar Sarika A 
Published: June 2021

Cataract is most common cause of blindness in the world. As it is an age related change, it is usually associated with other systemic illness. To assess the presence of systemic co morbidities found during routine preoperative evaluation in the patients undergoing cataract surgery at tertiary care hospital. Interventional study included patients attending the ophthalmology outpatient department who were operated for cataract surgery between Jun. 2019 and May. 2020 at tertiary health care centre. Out of 412 patients 147 (35.68%) had systemic co-morbidity and 66 had a presence of both systemic and ocular co-morbidity. Out of 147 patients with systemic co-morbidity hypertension was found in 79 (53.74%) patients while 47 (31.97%) presented with Diabetes Mellitus. Bronchial asthma and Ischemic heart disease was observed in 19 (12.93%) patients followed by stroke in 8 (5.44%) patients. Presence of systemic comorbidity increase the number of investigations needed for fitness of the patient for cataract surgery. Also it can cause intra operative complication and may affect surgical outcome.
Pengaruh Lalu-Lintas Kereta Api dan Shift Jaga di Era Pandemi Covid-19 Terhadap Persepsi dari Penjaga Perlintasan Kereta Api (PJL) di Wilayah Kerja Daerah Operasi (DAOP) 1 JAKARTA
Authors: Oktaria Dhina Setyo 
Published: June 2021

Penjaga perlintasan kereta api atau yang biasa disebut PJL adalah orang yang bersinggungan dengan keselamatan perkeretaapian di pintu perlintasan kereta api. Di era pandemik covid-19 PT KAI selaku penyelenggara perkeretaapian membatasi jumlah kereta api yang beroperasi. Penelitian ini membahas tentang lalu-lintas kereta api dan shift jaga di era pandemik covid-19 apakah mempengaruhi persepsi kinerja PJL di wilayah kerja. Daop 1 Jakarta. Metode penelitian berupa metode kuantitatif dan kualitatif dimana kuesioner yang disebarkan kepada PJL di wilayah kerja Daop 1 Jakarta menggunakan skala likert dengan nilai antara 1, 2 dan 3 dan di olah dengan SPSS 25. Pertanyaan di kuesioner di uji validitas dan reliabilitasnya. Analisis yang digunakan berupa Regresi linier berganda, Dilakukan uji klasik antara lain uji regresi distribusi normal, uji multikoliniearitas tolerance dan VIF, uji heteroskedastisitas dan uji autokorelasi Durbin Watson. Jumlah responden sebanyak 190 orang responden dengan teknik sampling teknik non-probability sampling berupa accidental sampling. Uji F Simultan jika nilai sig 0.05 Dimana signifikansi 0,000 0,05 maka variabel independent yaitu lalu-lintas kereta api (X1) dan shift jaga (X2) secara simultan berpengaruh terhadap persepsi (Y) atau variabel dependent. Uji F simultan jika nilai F hitung F dimana F hitung = 15,683 lebih besar daripada F tabel 3,04 artinya lalu-lintas kereta api (X1) dan shift jaga (X2) secara simultan berpengaruh terhadap persepsi (Y) dengan nilai 14,4%.Kata kunci : Persepsi, Penjaga perlintasan kereta api, Daerah Operasi 1 Jakarta, lalu-lintas kereta api, shift jaga
Does using constrained acetabular component really limit hip range of motion?
Authors: ÇELEN Zekeriya Ersin , OZKURT Bulent , UTKAN Ali , ARSLAN Aydin , GAFUROĞLU Tuba Ümit , ESER Filiz 
Published: June 2021

Aim: In surgical treatment of instability, constrained acetabular inserts are frequently used in hip arthroplasty. However the reasons why surgeons avoid constrained acetabular components are the concern of an increased rate of loosening possibly due to impingement and the concern of decreased range of motion. This study aims to investigate the influence of constrained acetabular insert usage on hip range of motions and functional results.
Material and Methods: Twenty-eight patients who needed revision hip arthroplasty were included. Patients were divided into two groups according to acetabular insert used in surgery (constrained and non-constrained). Mean follow-up period was 61±7 months (range, 50-74) in constrained group and 59±7 (range, 50-72) in non-constrained group. Hip range of motion and harris hip scores were recorded pre-operatively and at final follow-up.
Results: The final avarage flexion, abduction, adduction, external rotation and internal rotation was respectively 78°±15°, 43°±4°, 28°±3°, 30°±7°,19°±8° in constrained group (n=15) and 75°±14°, 40°±6°, 26°±5°, 30°±12°, 17°±6° in non-constrained group (n=13). The difference between groups was not statistically significant. Harris hip score increased in both groups and there was no significant difference between groups (p=0.730).
Conclusion: Findings of this mid term study showed that hip range of motions and functional results in patients with constrained acetabular inserts are not inferior than the patients with non-constrained inserts.
Paranazal sinüs anatomik varyantları ve hastalıklarının tanısında bilgisayarlı tomografi ile konvansiyonel manyetik rezonans görüntülemenin etkinliğininin karşılaştırması
Authors: ALTAN KUS Aylin 
Published: June 2021

Amaç: Çalışmamızda amacımız; paranazal sinüs anatomisi, anatomik varyantları ve hastalıklarının tanısında Bilgisayarlı Tomografi (BT) ile Konvansiyonel Manyetik Rezonans Görüntülemenin etkinliğini karşılaştırmaktır
Gereç ve Yöntemler: Çalışmamızda paranazal sinüs BT için kliniğimize başvuran 35 olguya aksiyel ve koronal kesitlerde BT incelemesi yapıldı. MRG‘nin ek katkısını araştırmak amaçlı; BT ile paranazal sinüslerin anatomik varyantları, mukozal kalınlaşmaları ve yer kaplayıcı lezyonları izlenen 35 olguda MR inceleme yapıldı. Her iki modalitedeki anatomik detaylar, anatomik varyasyonlar, enflamatuvar mukozal hastalık, yer kaplayıcı kistik ya da solid lezyonlar ve dental kaynaklı artefaktlar karşılaştırıldı.
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Bulgular: BT ile 35 hastada saptanan toplam 32 anatomik varyasyonların tamamı, 46 paranazal sinüs patolojisinin 44’ü MRG ile doğrulanmıştır. BT tanısı temel olarak alındığında sinonazal patolojilerde MRG’nin sensitivitesi %95.6 bulundu
Sonuç: Çalışmamız MRG’nin paranazal sinüs anatomik varyasyonları ve patolojilerinde BT’ye alternatif olarak kullanılabileceğini gösteren mevcut çalışmaları desteklemektedir
Which anemia is associated with mortality in COVID-19? Mild, moderate or severe ?
Authors: TEZCAN Büşra , ÇİFTÇİ Halis 
Published: June 2021

Aim:We aimed to investigate the prevalence of anemia at admission to intensive care unit (ICU), association between anemia and mortality, lengths of stay in hospital and ICU (LOS-H and LOS-ICU) in COVID-19 patients.
Material and Methods:We retrospectively analyzed the data of 288 COVID-19 patients who needed ICU admission. Patients were divided into two groups: anemic and nonanemic. Demographic data, labaratory findings at ICU admission, LOS-H and LOS-ICU, mortality were compared between groups. A further classification was made based on hemoglobin levels; severe, moderate and mild anemic patients were analyzed. LOS-H, LOS-ICU and mortality were compared between patients with hemoglobin > 109 g/L and ≤ 109 g/L. Thus; moderate and severe anemic patients were compared to mild anemic and nonanemic patients.
Results: Anemia was detected in 137 (47.6%) patients upon admission to the ICU. Of those; 54 patients (39.4%) had mild, 76 patients (55.5%) had moderate, 7 patients (5.1%) had severe anemia. Anemic patients were older, had multiple comorbidities, lower hemoglobin and albumin, higher red cell distribution width (RDW), creatinine and procalcitonin levels. While LOS-H, LOS-ICU and mortality rates did not significantly differ between anemic and nonanemic patients; mortality rate was significantly high in patients with hemoglobin levels ≤ 109 g/L (moderate anemic) compared to patients with a hemoglobin level > 109 g/L (mild anemic and nonanemic). LOS-H and LOS-ICU were not significantly different between these patient groups. Only seven patients had severe anemia and all of these died.
Conclusion: The results of this retrospective study showed that the anemia prevalence in ICU patients with COVID-19 was high, and mild anemia was not associated with higher mortality rates, while moderate and severe anemia were. Hemoglobin levels of anemic patients with COVID-19 should be closely monitored for timely detecting signs of disease progression.