bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reinterpretation by ray tracing of a transverse refraction seismic profile through the California Sierra Nevada, part I
Authors: Bolt Bruce A. , Gutdeutsch Rolf 
Published: June 2021

abstractThis study reanalyzes a refraction seismic profile from NTS, Nevada, to San Francisco transverse to the high Sierra Nevada. Three models of the Earth's crust, with an asymmetrical mountain root, constructed by different authors are tested by the use of ray tracing: model CQM (Carer et al., 1970), with a maximum crustal thickness of 35 km centered about 50 km west of the crest of the Sierra; models A and B (Pakiser and Brune, 1980), with a mountain root extending to a depth of 55 km below the Sierra. In the latter, guided and diffracted waves are used to explain seismic Pn energy in the shadow zone of the root. The preferred model A has a high-velocity layer, dipping from west to east in the upper crust, while model B does not.The present study demonstrates how fallacies in interpretation of complicated structures can occur if all ray types are not quantitatively traced. The influence of the P-wave gradient in the upper mantle on the length of the shadow zone is shown to be important, and it is demonstrated that a modified CQM model explains the observed travel times when diffracted waves are included. (CQM does not, however, explain why the Pn travel times on a separate refraction profile along the Sierra Nevada from a Truckee earthquake are so great.) Model B interprets the Pn signals at Δ &gt; 200 km as diffracted waves, but the computed travel times do not fit the observations. The dipping wave guide in model A does not work as expected and perhaps should be ruled out.
Probabilistic earthquake expectancy in the northeast Indian region
Authors: Goswami H. C. , Sarmah S. K. 
Published: June 2021

abstractGumbel's theory of extreme events has been applied to the prediction of earthquake recurrence rates in the northeast Indian region using the largest annual earthquakes occurring between 1929 and 1978, a period for which records are relatively complete. For the northeast Indian region, as a whole, the average return periods for an earthquake of magnitude 8 or greater, are found to be about 30 and 25 yr, applying Types I and III distributions, respectively. The magnitudes of the largest annual earthquakes expected to occur in 25, 50, and 100 yr for six different tectonic blocks of the region are also estimated.
Modeling focal parameters for the magnitude 5.3 earthquake of the Xinfengjiang Reservoir area, People's Republic of China
Authors: Zhu Chengnan , Liu Yuquan , Wang Chunyong , Lu Ruxi , Chen Jiande 
Published: June 2021

abstractIn this paper, the “random test-motion adjustment” method was used for the adjustment of the triangulation net of the Xinfengjiang Reservoir earthquake area, China, and for the inversion of the focal parameters of the earthquake of magnitude 5.3. Retriangulation and leveling data of the earthquake area were thus processed. The estimated focal parameters of the earthquake are: strike, NE 62°; dip, SE at 59°; length of the fault, 4.7 km; depth of the upper boundary, 0.45 km; depth of the lower boundary, 4.5 km; dip-slip dislocation, 73.4 mm; strike-slip dislocation, 25.5 mm; seismic moment, Mo, 2.2 × 1024 dyne-cm; stress drop (Δσ), 12 bars; and the lower limit of the strain energy released (E) 1.2 × 1019 ergs. It was predominantly a normal fault. This paper concludes that the regional stress field provided the main force of the shock, whereas the stress field due to hydraulic pressure contributed the inducing force.
Resonant scattering by fluid-filled cavities
Authors: McMechan George A. 
Published: June 2021

abstract
Interaction of seismic energy with a fluid-filled cavity results both in scattering by the cavity and in excitation of its normal modes. The normal modes contain information about the properties of the fluid that fills the cavity and its size. In the frequency domain, each mode in the cavity response can be decomposed into a sum of two spectra; the “background” scattering from an empty cavity and the resonant coupling between the fluid cavity filler and the surrounding matrix. Synthetic seismograms are computed by Fourier transformation and summing modes. The theory is applied to a water-filled crack in granite, a model for the core of Mars, and a magma chamber.
Toroidal modes of a simple laterally heterogeneous sphere
Authors: Morris Sandra P. , Geller Robert J. 
Published: June 2021

abstractTwo methods which have been proposed for calculating the normal modes of laterally heterogeneous models of the Earth are first-order degenerate perturbation theory and the Rayleigh-Ritz variational procedure. The purpose of this paper is to compare these two techniques in a calculation of some low-order toroidal modes of a simple laterally heterogeneous body—a sphere consisting of two hemispheres with different elastic properties. Both methods express the eigenfunctions of the test case as linear combinations of degenerate eigenfunctions of the corresponding laterally averaged model. Our results show, however, that solutions generated by the more accurate variational technique can contain significant contributions from modes from several degenerate multiplets, whereas each solution given by first-order degenerate perturbation theory contains the effects of modes from only one degenerate multiplet. Furthermore, the variational procedure yields solutions which reflect the presence of lateral heterogeneity of odd angular order, but first-order degenerate perturbation theory does not. These differences are potentially important for free oscillation studies of realistic, laterally heterogeneous models of the Earth: our findings suggest that the Rayleigh-Ritz variational procedure, or a comparably accurate method, may be required for such work.
The optical anchor—A geophysical strainmeter
Authors: Wyatt Frand , Beckstrom Kent , Berger Jon 
Published: June 2021

abstract
An instrument has been developed to monitor the horizontal displacement of near-surface monuments, so as to reduce the noise of observatory-based strain measurements. The device measures the shear strain in the upper 24 m of the earth's crust using an equal path length Michelson interferometer. The magnitude of the observations (∼50 μm) indicates that such measurements are needed to interpret the records produced by precision strainmeters.
Catalog of earthquakes felt in the eastern United States megalopolis (1850-1930)
Authors: Winkler Louis 
Published: June 2021

abstract
The area covered by this catalog is the region east of the Appalachians from the southern border of Virginia to the southeast tip of New York State. For the period 1850 to 1930, a total of 191 earthquakes were felt in the area. Of these earthquakes, 39 were damaging in the area of interest with intensities V-VI to VIII. The vast majority of the historical sources used to construct the description were local newspapers.
An appendix to this catalog includes additions and expansions of earthquakes in another catalog regarding the United States before 1850.
A preliminary investigation of tsunami hazard
Authors: Lin I-Chen , Tung Chi C. 
Published: June 2021

abstractA method for determining tsunami hazard is presented using simple seismological and hydrodynamic models.The seismological model assumes that submarine earthquakes of the dipstrike type can occur, with equal likelihood, anywhere along a well-defined straight fault and that the site under consideration lies on the perpendicular bisector of and far removed from the fault. The ground dislocation is circular in the horizontal plane, and the vertical offset is uniform. The radius of the circle and the vertical offset are related to seismic moment which is assumed to be random.The hydrodynamic model is based on linear dispersive wave theory. It is assumed that the earth is flat, water depth constant, and ocean infinite in horizontal extent. The maximum elevation of water surface of the leading wave is related to ground motion characteristics (or seismic moment) and the distance from the site to the source.The probability of the event that the water elevation at a site exceeds an arbitrary but specified level is then derived and computed. A sensitivity study is performed to determine the importance of various parameters.
A real-time digital seismic event detection and recording system for network applications
Authors: Michael Andrew J. , Gildea Stephen P. , Pulli Jay J. 
Published: June 2021

abstract
A real-time digital seismic event detection and recording system has been developed for the MIT Seismic Network. The system has been designed specifically for an environment of low natural seismic activity and for surface stations which are often influenced by weather conditions and cultural noise. The system runs on an HP-1000 computer and can handle up to 16 channels of short- and long-period data. The structure of the system centers around the event detectors, one for short-period data and one for long-period data. These detectors base their decisions on a metric computed from the Walsh transform of the data. This allows them to detect changes in the amplitude of the waveform as well as frequency shifts. Detections at several stations are correlated to prevent glitches from triggering the detector. Present operation successfully saves those events that are large enough for analysis and leaves 23 of the computer available for general timesharing use.
Inversión en línea y emociones durante la experiencia del usuario de un videojuego
Authors: Aucay-Orellana Diana Carolina , Culqui-Cuenca Julio Alejandro , Tinoco-Egas Raquel Miroslava , Herrera-Peña Jonathan Neptalí 
Published: June 2021

La era tecnológica ha transformado los hábitos y las costumbres de muchas personas, creando la nueva cultura digital; siendo las últimas generaciones quienes han conseguido adaptarse con mayor facilidad. El presente trabajo investigativo recaba información que puede ser utilizada por la industria de los videojuegos, ya que permite entender el comportamiento de sus usuarios y a como incitarlos a consumir sus productos digitales. El objetivo de esta investigación es identificar el comportamiento de compra de los usuarios dentro del videojuego Free Fire, producto de las emociones que se producen durante la experiencia de juego. Para ello se optó por la metodología exploratoria-descriptiva; mediante la cual se tomaron datos desde los estímulos cerebrales de los videojugadores mientras interactuaban dentro del juego y se los comparó con el comportamiento de inversión del jugador. Los resultados demostraron que la emoción del interés de los jugadores por el videojuego no es suficiente para que exista inversión en línea juegan un rol importante las emociones de compromiso, interés y relajación.
Palato-gingival groove: A silent nidus. Recognition and an innovative management approach: A report of 3 cases
Authors: Rangaswamy Purushothama , Harsha Tummala Sri , R Magarvalli Samrat , Ramachandra Sujith , Govindappa Kavitha , E Shwetha 
Published: June 2021

Developmental anomalies are one of the challenging clinical conditions to achieve successful treatment outcomes. Among these, Palatogingival groove [PGG] is a rare developmental anomaly usually found on the palatal aspect of maxillary anterior teeth. As self-cleansing is difficult in such patients, it can lead to serious localized periodontal lesion or can occur in combination with endodontic lesion. It is our sole responsibility being a specialist in the field of dentistry, to early diagnose and provide treatment for such conditions. On the basis of PGG extension to the pulp, it can be classified as simple or complex; accordingly, plethora of treatment options are available. Clinically taking interdisciplinary treatment modalities into consideration, curettage of the involved gingival tissues, elimination of the groove by grinding (saucerization), or by sealing with a Biocompatible material which might enhance the healing potential. Incase if the groove extends beyond the middle-third of the root, surgical flap debridement along with combined use of barrier membrane and alloplastic bone graft are recommended.This article represents a rare clinical case reports in management of PGG defect with an innovative conservative approach for simple, minimal groove extensive case and groove extension beyond 1/3 of the root region, treated with surgical multi-interdisciplinary approach.
The impact of covid-19 on ophthalmic practice in Bangladesh– A cross-sectional study
Authors: Ul Kadir Syeed Mehbub , Moniruzzaman Muhammad , Rahman Siddiqur , Nasa Khairun , Ahmed Tanvir , Maurya Rajendra Prakash 
Published: June 2021

To assess the interference of patient care due to COVID 19 related restrictions and to formulate the future guidelines.This cross-sectional online survey-based study was carried out among the ophthalmologist of Bangladesh in the early lock down period (01 April to 30 April) 2020. Total 93 ophthalmologists responded to the study. Most of the ophthalmologist were seeing the patients with red eye (40.9%), ocular trauma (40.9%), acute infections and inflammations (35.5%), and vision loss (31.2%). 80.6% responder informed that they wear Mask, gloves, and head cap during patient evaluation. 51.6% used Personal protection equipment. 55.9% used a breath shield with the slit lamp settings. 60.4% maintained hand wash, and disinfectant facilities for the patients. 85.7% ophthalmologist had ensured for wearing the mask to all patients before entering the examination and consultancy room. 86% ophthalmologist of our study had performed their surgeries for ophthalmic emergency.Wearing mask is an important tool to prevent transmission of COVID-19 for both patients and ophthalmologists in working place. Maintaining normal ophthalmic practice and surgery are challenging during COVID-19 pandemic.
A comparative study of efficacy of chloroquine phosphate 0.03% and sodium carboxymethylcellulose 1% in dry eye
Authors: Sharma Vandana , Tyagi Parag , Chugh J P , Chauhan R S , Rathi Ashok 
Published: June 2021

Dry eye disease (DED) is a multifactorial disease of the tear film which leads to ocular discomfort, visual disturbances and damage to ocular surface. The objective of treatment of DED has now shifted from managemnt of ocular symptoms and patient relief to attainment of normal physiological composition of the tear film.Aim of this study was to compare the efficacy of chloroquine phosphate 0.03% (CQP) eye drops with sodium carboxymethyl cellulose 1% (CMC) eye drops in the management of DED.A single blind, prospective and comparative study including 100 patients of dry eyes was planned. The patients were randomly divided into two groups, each comprising of 50 patients. Group-1 patients were given CMC 1% eye drops 4 times a day for 12 weeks and Group-2 patients were given CQP 0.03% eye drops as the treatment modality 2 times a day for 12 weeks. The efficacy of both the drugs was compared and evaluated statistically.The study showed that both CQP and CMC eye drops are effective in treating DED, although faster onset of action was observed with CQP on ocular surface staining tests and Schirmer’s test. Also, it was noted that patients with severe DED showed least improvement in both the groups suggesting that mono-drug therapy is least effective in treatment of severe DED and multi drug therapy should be used early in treatment of severe DED.
Aqueous humor pharmacokinetics of Benzalkonium chloride free bimatoprost formulated in tight junction modulation technology compared to Benzalkonium chloride preserved bimatoprost 0.01% ophthalmic solution in rabbit eyes
Authors: Khopade Ajay J , Halder Arindam , Burade Vinod , Vakharia Monali 
Published: June 2021

This study was undertaken with an objective to compare the aqueous humor pharmacokinetics (PKs) of bimatoprost and bimatoprost free acid of innovator bimatoprost 0.01% (BAK-Bimatoprost) and the novel formulation, Tight Junction Modulation technology based bimatoprost 0.01% (TJM-bimatoprost) containing polyhexamethylene Biguanide hydrochloride (PHMB) as a preservative.All animals in the study were assigned to one of two treatment arms: either a single dose of BAK-Bimatoprost (n=28) or a TJM-bimatoprost ophthalmic solution (n=28). Time points for aqueous humor collection were 0.5, 1, 2, 4, 8, 12 and 24 Hrs after drug administration. The mean Cmax of 11.93± 2.70 vs 10.92± 3.84 ng/ml was comparable (P&#62;0.05, one-way ANOVA) across TJM bimatoprost and BAK-bimatoprost treatment arms. Results of other PK parameters pertaining to bimatoprost+ bimatoprost free acid concentration were as follows: time to maximum concentration (T_max) was 1.75± 2.0 vs 1.50 ± 1.16 hr and half-live (T_half) was 2.13 ± 0.58 vs 2.47 ± 0.79 hr in the TJM- bimatoprost and BAK-bimatoprost treatment arms respectively. Overall, there was no difference between TJM-bimatoprost and BAK-bimatoprost treatment arms in the PK end points. The results taken in totality support the hypothesis that pharmacokinetics TJM-bimatoprost 0.01%, containing PHMB preservative, is comparable to BAK-bimatoprost 0.01%. A new formulation of bimatoprost 0.01% using Tight Junction Modulation technology is pharmacokinetically comparable to marketed formulation of bimatoprost containing benzalkonium chloride preservative.
Evaluation of changes in the keratometric values after pterygium excision with conjunctival autografting in different grades of pterygium
Authors: Laad Sagarika , Damle Vasudha , Agarwal Prakash Chand 
Published: June 2021

To study the changes in keratometric values after pterygium excision with conjunctival autograft in different grades of pterygium. A retrospective, comparative study was done on 75 patients of various grades of pterygium who underwent excision surgery with conjunctival autograft. Preoperative and postoperative details of all the patients on 1, 7 and 30 day were taken into account including detailed ocular examination, best-corrected visual acuity, slit-lamp biomicroscopic examination, keratometric details and posterior segment examination. Net astigmatism was calculated preoperatively and on post-op examinations. Mean of difference in preoperative and post operative net astigmatism is calculated and compared in different grades of pterygium. Our study showed that there are significant changes in net astigmatism after pterygium excision mainly in grade 3 pterygium. Difference in mean net astigmatism at the end of 1 month from preoperative values was 2.39±0.73 in Group C, 1.45±0.5 in Group B and 0.49±0.24 in group C and this difference is significant. The amount of keratometric astigmatism is proportional to grades of pterygium (size of pterygium) and pterygium excision reduces the induced astigmatism and it varies according to grades.
Evaluation of strabismus in 0-18 years of age group in tertiary health care hospital: A prospective cross-sectional observational study
Authors: Champaneria Dhruvi K , Trivedi Harish R 
Published: June 2021

The main objective of the study was to study the pattern of strabismus, determine the type of refractive error and measure the angle of deviation, determine streoacuity by WFDT in 0-18 years of age group. This was a prospective cross-sectional observational study. Total 50 patients were taken. Patients of 0-18 years of age presenting with squint included in study. Patients were evaluated for VA, both distance and near vision without glasses as well as BCVA tested. Anterior segment evaluation using slit lamp, cycloplegic refraction using atropine (0-9 years) or cyclopentolate (10-18 years), fundus examination, PBCT, WFDT test done. In study, total 50 subjects of 0-18 years of age group was taken. In them boys were more than girls. 49(98%) had comitant strabismus and 1(2%) had incomitant strabismus. 32(64%) had esotropia and 18(36%) had exotropia. Among esotropia 11(34.37%) had accommodative esotropia, 13(40.62%) had partially accommodative, 7(21.87%) had non accommodative, 1(3.12%) had restrictive esotropia. Among exotropia 9(50%) had basic exotropia, 6(33.33%) had divergence excess and 3(16.66%) had convergence insufficiency. 14(28%) had amblyopia. 32(64%) had hypermetropia and 18(36%) had Myopia. 33(64%) had central fixation and 12(24%) had eccentric fixation. In binocularity, 6(12%) had ARC, 25(50%) had unilateral suppression, 10(20%) had alternate suppression.Comitant squint was more common than incomitant squint. Among comitant squint, esotropia was more common than exotropia.
UTILIZAÇÃO DE UMA ÁREA DE PROTEÇÃO AMBIENTAL POR UMA COMUNIDADE DE ELASMOBRÂNQUIOS NO ATLÂNTICO SUL OCIDENTAL
Authors: Aragão Georgia Maria de Oliveira , Kotas Jorge Eduardo , Spach Henry Louis 
Published: June 2021

Globalmente a explotação dos peixes cartilaginosos marinhos é cada vez mais crescente principalmente em áreas costeiras. Entretanto, existem áreas no Atlântico Sul Ocidental que ainda são pouco conhecidas quanto a sua biodiversidade de elasmobrânquios. Portanto, o objetivo deste trabalho é de conhecer a comunidade de elasmobrânquios marinho-estuarinos e suas respectivas áreas de uso em uma unidade de conservação de uso sustentável (APA do Delta do Parnaíba), no nordeste do Brasil, a partir do monitoramento dos desembarques da pesca artesanal na região. A partir do monitoramento de 1184 desembarques realizados entre janeiro de 2016 e janeiro de 2017, foi possível identificar nove espécies de tubarões (Carcharhinus leucas, C. porosus, C. acronotus, C. limbatus, Galeocerdo cuvier, Sphyrna mokarran, S. lewini, Rhizoprionodon porosus e Ginglymostoma cirratum) e sete espécies de raias (Hypanus guttatus, H. americanus, H. marianae, Fontitrygon geijskesi, Gymnura micrura, Aetobatus narinari e Rhinoptera bonasus) que fazem uso de três áreas batimetricamente distintas. As espécies com as maiores frequências de ocorrência foram R. porosus (36%) e H. gutattus (61%). Os resultados demonstram que a área é utilizada por distintas espécies, dentre elas espécies consideradas em risco de extinção, como o S. mokarran.USE OF AN ENVIRONMENTAL PROTECTION AREA BY A COMMUNITY OF ELASMOBRANCHS IN THE TROPICAL SOUTHWESTERN ATLANTICABSTRACTWorldwide the exploitation of marine cartilaginous fi sh is increasing, mainly in coastal regions. However, there are areas in the Southwestern Atlantic that are still little known about their elasmobranch biodiversity. Therefore, this work aims to know the community of marine estuarine elasmobranchs and their respective areas of use in a sustainable use conservation unit (APA of the Parnaíba Delta), in the northeast of Brazil, from the monitoring of the landings of the fi shingin the region. From the monitoring of 1184 landings between January 2016 and January 2017, it was possible to identify nine species of sharks (Carcharhinus leucas, C. porosus, C. acronotus, C. limbatus, Galeocerdo cuvier, Sphyrna mokarran, S. lewini, Rhizoprionodon porosus and Ginglymostoma cirratum) and seven species of stingrays (Hypanus guttatus, H. americanus, H. marianae, Fontitrygon geijskesi, Gymnura micrura, Aetobatus narinari and Rhinoptera bonasus) which make use of three diff erent depth ranges. The most frequent species were R. porosus (36%) and H. gutattus (61%). The results demonstrate that the area is used by diff erent species, among them species considered endangered, such as S. mokarran.Keywords: Selachians; Batoids; Conservation biology.