bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical and mathematical modeling of transients in a synchronous generator utilizing synchronized phasor measurements
Authors: Rafikov V.R. , Ivanov I.E. , Bratoliubov A.A.
Published: June 2021

There have been quite a few attempts to compute synchronous generator parameters based on voltage and current synchrophasors taken under power system transients. However, we have not seen any publications with thorough analysis as to how soon the phasor measurement unit reacts to disturbance conditions, which components of the transient are filtered out and which are passed through, as well as what the total vector error is. The goal of this research is to determine all of these characteristics of a phasor measurement unit when playing back transient oscillograms for a stator short circuit obtained through mathematical modeling. The transient oscillograms have been derived via both a full Park-Gorev system of flux linkage equations as well as the MATLAB/Simulink Synchronous Machine block. Physical modeling was then conducted via a real-time digital simulator (RTDS) along with a dedicated phasor measurement unit ENIP-2 (PMU), and the stator current phasors were recorded. Our analysis has shown that both RTDS and ENIP-2 (PMU) almost entirely filter out the exponentially decaying DC component of the fault current while closely following the periodical signal envelope. The total vector error has been estimated to become below 1–2 % after around 0,02–0,03 s into the fault when selecting the “P” class filters according to IEEE C37.118. We have come to a conclusion that synchrophasor measurements under power system disturbances could be utilized for estimating the synchronous, transient, and subtransient generator parameters. The selected synchronous machine model in the form of flux linkage equations is correct, as the obtained transient oscillograms are exactly the same as those produced by Simulink. “P” class phasor measurements can be recommended for representing transients in the stator circuit of a synchronous generator. The results of this investigation are meant to be employed for synchronous machine parameter estimation based on phasors sourced from RTDS and, hopefully, from phasor measurement units installed at power plants.
Electrocatalytic Effect of Al2O3 Supported on Clay in Oxidizing of Ibuprofen at Graphite Electrode
Authors: EL Ouafy Hayat , EL Ouafy Tarik , Oubenali Mustapha , EL Haimouti Aziz , Gamouh Ahmed , Mbarki Mohamed
Published: June 2021

In this work, the electro-catalytic oxidation of ibuprofen was studied using aluminum oxide supported on clay (Clay/Al2O3). The latter has been successfully prepared by impregnating aluminum particles in the clay by heat treatment. The electro-catalytic performances of Clay/Al2O3 for the oxidation of ibuprofen were studied using cyclic voltammetry (CV), chronoamperometry, and differential pulse voltammetry (DPV) in 0.1 mol L-1 of the phosphate buffer (pH = 7). It has been shown that the proposed catalyst exhibits remarkably an electro-catalytic effect performance vis-a-vis the oxidation of ibuprofen. In addition, the peak oxidation currents depend linearly on the ibuprofen concentration in the wide ranges from 1.0·10-3 mol L-1 to 1.0·10-6 mol L-1 with a detection limit of 1.95·10-8 mol L-1 and response time of 30 second. Possible interferences were evaluated in 1.0·10-5 mol L-1 ibuprofen. The proposed catalyst also indicated suitable repeatability and stability. Besides, the proposed CPE-Clay/Al2O3 has been successfully applied for ibuprofen analysis in human blood with good recoveries.
From Colour Catcher® to colorimetric sensors: disposable and cheap devices for inorganic ions determination
Authors: Alberti Giancarla , Callegari Sofia , Concardi Ilaria , Ronca Lorenzo , Sbardi Maria Teresa
Published: June 2021

We describe disposable and cheap colorimetric devices obtained by fixing classical dyes on the commercial paper sheet known as "Colour Catcher®" (here named under the acronym CC), the product used to prevent color runs in washing machines cycles. These devices can be used as colorimetric sensors for different analytes of environmental and biological interest since the indicator dye, fixed on the solid material, changes its spectral properties (color and hence UV-vis spectrum) upon contact with the analyte. The relationship between the analyte content and the UV-vis spectrum (or RGB values) change of each sensor is provided using a chemometric tool: the Partial Least Squares regression (PLS). Promising results were obtained when applying these sensors to actual samples, so because of their simple preparation with low-cost reagents, they can be effective for application in environmental and food analysis.
The Severity of Situational and Personal Anxiety Among University Students with Disabilities During the Pandemic
Authors: Petrova E.A. , Nazarenko V.V.
Published: June 2021

The paper presents the results of a study of situational and personal anxiety among university students with disabilities during the COVID-19 pandemic (Spring 2020). The study involved 35 students with disabilities from Russian State Social University aged 18—26 (21 men and 14 women). We used 2 questionnaires for measuring anxiety: Spielberger State-Trait Anxiety Inventory and Taylor Manifest Anxiety Scale. The results allowed us to make conclusions about the increased level of situational anxiety, as well as about pronounced personal anxiety in the studied category of students. The study has practical importance for the organization of psychological sup- port for students with disabilities at the university.
Solving two-point seismic-ray tracing problems in a heterogeneous medium
Authors: Pereyra V. , Lee W. H. K. , Keller H. B.
Published: June 2021

abstract

A study of two-point seismic-ray tracing problems in a heterogeneous isotropic medium and how to solve them numerically will be presented in a series of papers. In this Part 1, it is shown how a variety of two-point seismic-ray tracing problems can be formulated mathematically as systems of first-order nonlinear ordinary differential equations subject to nonlinear boundary conditions. A general numerical method to solve such systems in general is presented and a computer program based upon it is described. High accuracy and efficiency are achieved by using variable order finite difference methods on nonuniform meshes which are selected automatically by the program as the computation proceeds. The variable mesh technique adapts itself to the particular problem at hand, producing more detailed computations where they are needed, as in tracing highly curved seismic rays.

A complete package of programs has been produced which use this method to solve two- and three-dimensional ray-tracing problems for continuous or piecewise continuous media, with the velocity of propagation given either analytically or only at a finite number of points. These programs are all based on the same core program, PASVA3, and therefore provide a compact and flexible tool for attacking ray-tracing problems in seismology.

In Part 2 of this work, the numerical method is applied to two- and three-dimensional velocity models, including models with jump discontinuities across interfaces.
Induced versus natural earthquakes: Search for a seismic discriminant
Authors: Peppin William A. , Bufe Charles G.
Published: June 2021

abstract

A sizeable body (150 records) of three-component, wideband (0.2 to 50 Hz) digital seismic data has allowed a direct comparison between earthquakes at The Geysers geothermal area, California and along nearby active faults of the San Andreas system. An attempt has been made to find analog or spectral parameters which would permit discrimination between 12 events within the steam production field and 30 outside it. Results of the study for both classes of events are: (1) seismic moments vary with local magnitude ML as log M0 = (1.06 ± 0.11) ML + 16.9 ± 0.1; (2) the ratio of vertical P-wave to horizontal S-wave spectral corner frequencies is near unity; (3) seismic stress drops are low (1.0 to 10 bars); and (4) focal mechanisms are quite comparable during the time period of this study.
Tidal tilt from localized ocean loading in the New Hebrides Arc
Authors: Marthelot Jean-Michel , Coudert Elisabeth , Isacks Bryan L.
Published: June 2021

abstract

Tidal signals recorded by two tiltmeters located near the coast on Vate Island (New Hebrides) are interpreted in terms of the loading effect of the local tide. Homogeneous and stratified elastic models are used in the computation of the theoretical tilts due to the tidal loading. The direction and the magnitude of the tidal tilt recorded at a distance of 120 m from the coast indicate the presence of a surficial layer with a very low value of rigidity overlying materials with much higher rigidity.
S-wave velocity measurements in deep soil deposit and bedrock by means of an elaborated down-hole method
Authors: Ohta Y. , Goto N. , Yamamizu F. , Takahashi H.
Published: June 2021

abstract

Deep S-wave velocity measurements were planned at two separate sites in the Tokyo area from the earthquake engineering point of view, and actually carried out down to 2 to 3 km in depth using geophysical observation wells.

S-waves were produced by means of ordinary small explosions and a specially designed SH-wave generator. A set of three component seismometers was installed in a capsule having a device that is clamped to the borehole wall. Measurements to the bottom of the wells were conducted at about 15 different depths at intervals of 100 to 500 m.

The S-wave velocities are around 0.8 km/sec in Pleistocene soils, 1.2 to 1.6 km/sec in Miocene soils, and 2.5 to 2.7 km/sec in Cambrian rocks. The corresponding P-wave velocities are 2.0 to 2.3 km/sec, 2.6 to 3.0 km/sec, and 4.7 to 4.9 km/sec, respectively. These data show both S- and P-wave velocities in deep soil deposit increasing with depth. The greatest velocity difference is at the boundary above the pre-Tertiary rocks.

The velocity structures completely agree with the known data such as sonic logs, density distributions, and geological sections. A comparison with velocity profiles at two separate sites was also made as the first step to visualize the three-dimensional underground structure in the Tokyo metropolitan area.

The seismological and earthquake engineering importance of shear-wave velocity measurements for thick soil deposits was demonstrated by approximate calculations of the amplification of seismic waves between ground surface and bedrock.
Temporal variation of seismicity and spectrum of small earthquakes preceding the 1952 Kern County, California, earthquake
Authors: Ishida Mizuho , Kanamori Hiroo
Published: June 2021

abstract

The spatio-temporal variation of seismicity in the epicentral area of the 1952 Kern County California, earthquake (Ms = 7.7, 34°58.6′N; 119°02′W) was examined for the period prior to the main shock. Most of the events that occurred in the epicentral area were relocated by using the main shock as a master event. A large part of the fault plane of the Kern County earthquake had been seismically quiet for nearly 15 yr before the main shock. However, the activity in the immediate vicinity of the epicenter had been very high during the same period. The temporal variation of the activity in the vicinity of the epicentral area exhibits a pattern very similar to that found for the 1971 San Fernando earthquake. During the 112 yr period immediately before the main shock, tight clustering of activity around the main-shock epicenter occurred. This clustering may be considered to be foreshock activity. This period of increased activity was preceded by a quiet period for 2 yr from 1949 to 1950; no event was located on the fault plane of the Kern County earthquake during this period. This pattern, quiescence followed by clustering, seems to have repeated several times prior to 1949. Thus, this pattern alone cannot be used as a definite indicator of a large earthquake, but in terms of a fault model with asperities, it can be a manifestation of progressive stress concentration toward the eventual hypocenter. Spectral analyses of the Pasadena Wood-Anderson seismograms of the events that occurred near the epicentral area showed that the frequency of the spectral peak is systematically higher for the foreshocks than the events prior to 1949. A similar trend was found for the 1971 San Fernando earthquake. These results are consistent with the model of stress concentration around the eventual hypocenter.
A technique for the recovery of the seismic moment tensor applied to the Oaxaca, Mexico earthquake of November 1978
Authors: Ward Steven N.
Published: June 2021

abstract

The potential for using seismograms in a linear inversion process to recover the seismic moment tensor has been theorized for sometime. Unfortunately, practical application of the theory is difficult. Lateral variations of the Earth and imprecise knowledge of the source often severely contaminate real seismic data relative to synthetic models which must be supplied. This paper outlines an experiment which minimizes the contamination sufficiently to permit a successful inversion yet retains much of the data's sensitivity to source parameters. Routineness of technique was maintained in data selection and preparation by an unambiguous on-line windowing of P phases from the SRO network. Duplicate preparation of the theoretical P phases assured their synchronization with the observations. A time domain weighted least-squares inversion was implemented including double couple and nondouble couple constraints. Estimates of the total variance in addition to variances of the moment tensor eigenvalues and eigenvectors were returned, forming the basis for statistical tests. Seismic moments of 1.4 ± 0.4, 2.8 ± 0.3, and 2.7 ± 0.2 ×1027 dyne-cm were found for the Oaxaca, Mexico earthquake of November 1978, using 10 P phases in the distance ranges 20 to 120°, 25 to 120°, and 40 to 120°, respectively. Corresponding azimuth and dips of the probable slip vector are 21.5°, 11.8°; 30.3°, 9.3°; and 32.1°, 9.0°. No evidence was found to support the hypothesis that unconstrained source models fit the data significantly better than a double couple. We believe an automated procedure such as this is a viable means for the routine recovery and cataloging of earthquake sources.
Direct observation of a p-τ curve in a slant stacked wave field
Authors: McMechan George A. , Ottolini Richard
Published: June 2021

abstract

The well known Wiechert-Herglotz technique for computing a velocity-depth profile from refraction seismograms uses data in the form of ray parameter as a function of intercept time (a p-τ curve). The technique of slant stacking used by reflection seismologists automatically produces a p-τ curve from a common shot profile, thereby bypassing arbitrary travel-time picking and several intermediate calculations of previous methods. Successful preliminary results are presented for both synthetic and real data. This method deteriorates for widely separated geophones and where a number of apparent sources with low inter-source coherency coexist in a single profile, but is capable of completely sorting out triplications in data with less extreme contrasts without human intervention.
Surface waves in structures with locally irregular boundaries
Authors: Suteau Anne , Martel Louis
Published: June 2021

abstract

The transmitted field due to surface waves incident on a local irregularity of a plane-layered medium has been studied. A perturbation method to the first order and the Born approximation can be used if the variations in the thickness of the layers are sufficiently smooth and the wavelengths are long when compared to the size of the irregularities. The spectrum of the perturbed part of the displacement field at the surface is a sum over the surface-wave modes for the regular medium, with an additional term involving the scattered body waves. Numerical computations have been performed for structures composed of a layer overlying a half-space. The contribution of the various modes to the transmitted Love or Rayleigh fields has been studied for several structures. A general method has been obtained to analyze the effect of a complex structure as the superposition of the fields due to simpler ones. When the layer thickness is kept unchanged, the incident mode is not perturbed to the first order. Synthetic seismograms, computed at stations sufficiently close to the irregular region, show how the perturbation of the signal depends on distance. A comparison has been made for Love waves with a finite element method. Both methods give very similar results when the stations are not too close to the irregularities so that the body-wave contribution is negligible. The local phase velocity shows departures from the curves for a regular model.
The ratio of the travel times forSandPat distances less than 10°
Authors: Hales A. L. , Muirhead K. J.
Published: June 2021

abstract

The ratios of the S and P travel times, Ts/ Tp, observed at central Australian stations from Banda Sea earthquakes with depths between 100 and 200 km are less than the corresponding ratios for surface explosions in the same distance range. This result is surprising and inconsistent with the increase in the Vp/ Vs ratio with depth inferred from laboratory measurements on upper mantle minerals. Studies from several continental regions, including Japan, and oceanic regions, show similar low values.

Possible reasons for the inconsistency are discussed. Studies of three well-observed earthquakes in the Hokkaido region lead to the conclusion that the depths of earthquakes in the 60 to 200 km depth range are systematically underestimated by ISC and that there is an associated error in the times of origin of about 3 sec. Using corrected origin times, the average value of the Ts/ Tp ratio over the distance range 0° to 8° is about 1.785.
Rapid solution of ray tracing problems in heterogeneous media
Authors: Thurber C. H. , Ellsworth W. L.
Published: June 2021

abstract

The determination of local earthquake hypocenters and orgin times from first-P-arrival times by Geiger's method requires a technique for finding the minimum travel time (and derivatives) between the source and the station. Sophisticated ray tracing techniques have been developed for this purpose for use in complex velocity structures. Unfortunately, the two common techniques, shooting and bending, are generally prohibitively expensive for routine use in data analysis. The bending method is also particularly vulnerable to the problem of local minima in travel time. A method has been developed known as the ray initializer, which can be used to circumvent these problems in many cases. First, the technique can find a reasonable estimate of the minimum-time ray path in a quick and efficient manner. The velocity in a region local to the source and receiver is laterally averaged to yield an approximate layered velocity model. One-dimensional ray tracing techniques are used to find the minimum-time path for this layered structure. The ray path estimate can then be used as the starting path in a bending routine, a procedure resulting in more rapid convergence and the avoidance of local minima. Second, the travel time found by numerical integration along the estimated ray path is an excellent approximation to the actual travel time. Thus, in many cases, the ray initializer can be substituted for a three-dimensional ray tracing routine with a tremendous increase in efficiency and only a small loss in accuracy. It is found that the location of an explosion, derived using the ray initializer, is nearly identical to a complete ray tracing solution, even for a highly complex velocity structure.
Crust and upper mantle structure along the flank of Kōko Seamount
Authors: Furukawa K. , Gettrust J. F. , Kroenke L. W. , Campbell J. F.
Published: June 2021

abstract

Inversion of an 80-km-long reversed seismic refraction profile near the northwestern flank of Kōko Seamount indicates that the crust adjacent to the southern end of the Emperor Seamount chain is approximately 9-km thick with no dip in the refracting horizons. These data require positive P-velocity gradients in the crust and upper mantle to fit the observed amplitudes.

The crustal refractor P velocities and crustal thickness found are in general agreement with those found previously for the Emperor chain and near the Hawaiian Ridge. It is inferred from our data that the tectonic mechanism which created the Emperor and Hawaiian chains was highly localized.
Attenuation of intensity with epicentral distance in the Philippines
Authors: Vanmarcke Erik H. , Lai Shih-Sheng P.
Published: June 2021

abstract

With data from 83 earthquakes in the Philippine region, an intensity attenuation equation is derived in the form: I(R) − Io = 4.01 − 0.015 R − 2.40 log R. This compares very favorably with results for a tectonically similar region, the San Andreas region, derived by Howell and Schultz (1975).
Analysis of small seismographic station networks
Authors: Uhrhammer Robert A.
Published: June 2021

abstract

A procedure is developed for objectively analyzing the geometrical configuration of a small seismographic station network. The elements of the parameter space covariance matrix are used to determine the uncertainty in the hypocentral parameters and their corresponding cross-correlations for a given network geometry. Likewise, the elements of the data space covariance matrix are used to determine which data supply the least information toward the solution of the system of equations and which combinations of observations are redundant. Knowledge of the variation of these covariance matrices in the vicinity of a network allows an objective basis for comparing the performance of proposed network geometrical configurations.

A small triangular quadripartite network (10-km radius) is analyzed as an example of the method. For small networks, generally the most important data are S-wave onset times at the peripheral stations and P-wave onset times at the interior stations. The single most useful indicator of the performance of a proposed network configuration is the span of the semi-major axes of the covariance matrices for hypocenters in the vicinity of the network.
Fault impedance and earthquake energy in the Fourier transform domain
Authors: Andrews D. J.
Published: June 2021

abstract

The response of the elastic medium in which a fault is contained determines one relation between the slip function and the stress function on the fault. In the space-time domain, the slip and stress functions are related by a singular integral equation. If a Fourier transformation is performed over the two space dimensions on the fault and over time, the stress transform equals the slip rate transform times an impedance function. Using this impedance function, we may determine the energy radiated or stored in the elastic medium from either the slip or the stress transform.
The reproducing earthquakes of the Galapagos Islands
Authors: Kaufman Kris , Burdick L. J.
Published: June 2021

abstract

The largest swarm of earthquakes of the last few decades accompanied the collapse of the Fernandina caldera in the Galapagos Islands in June of 1968. Many of the events were relatively large. (The largest 21 had moments ranging from 6 ×1024 to 12 ×1024 dyne-cm.) They produced teleseismic WWSSN records that were spectacularly consistent from event to event. The entire wave trains of the signals were nearly identical on any given component at any given station. This indicates that the mode of strain release in the region was unusually stable and coherent.

The body waveforms of the events have been modeled with synthetic seismograms. The best fault plane solution was found to be: strike = 335°, dip = 47°, and rake = 247°. The depths of all the larger shocks were close to 14 km. Previous work had suggested that the seismic energy was radiated by the collapsing caldera block at a depth of about 1 km. The new results indicate that large scale extensional faulting at depth was an important part of the multifaceted event during which the caldera collapsed.
The McNaughton Lake earthquake of May 14, 1978
Authors: Rogers Garry C. , Ellis Robert M. , Hasegawa Henry S.
Published: June 2021

abstract

At 22h37m02s UTC on May 14, 1978, a magnitude (ML) 4.8 earthquake occurred in the Canadian Rockies near McNaughton Lake, the large reservoir behind the Mica Dam in eastern British Columbia. The data suggest it was not a reservoir-induced earthquake.

The earthquake was within a seismic array monitoring the reservoir and consequently, the epicenter is well constrained in a northwest-southeast direction. The preferred epicenter is 52.65°N, 118.89°W, slightly east of the Rocky Mountain Trench, with a shallow focal depth of about 10 km. There were no foreshocks but a normal aftershock sequence. The focal mechanism, the first for the eastern Canadian Cordillera, indicates predominantly right-lateral strike-slip faulting along the strike of the mountains with a significant thrust component. The moment is 4 ± 2 × 1023 dyne-cm with a low stress drop (<10 bars). A well-developed Lg phase was recorded to the south of the earthquake. The isoseismals are elongated in a north-south direction and the rate with which intensity attenuates in a southerly direction is comparable to that for eastern North America.
Relocation of Koyna earthquakes
Authors: Rastogi B. K. , Talwani P.
Published: June 2021

abstract

The Koyna earthquake of December 10, 1967 was the most damaging reservoir-induced earthquake. It was followed by a long sequence of earthquakes which is still continuing. Precise locations of the Koyna earthquakes have been very much disputed as different locations of the main earthquake and stronger aftershocks were obtained by various workers. Over 1,500 epicenters of Koyna earthquakes through 1973 were obtained by Guha et al. (1974). They cover a large area in a diffused pattern. In view of the continuing seismicity and a recently obtained seismic velocity model, the larger events (ML ≧ 4.0) and about 300 selected smaller events (ML < 4.0) were relocated.

The relocated epicenters show some concentration and suggest the possibility of two trends in the NNE and NW directions. There is a NNE trend of epicenters near the dam and another about 20 km west of the reservoir. The NW trend cuts through these NNE trends. The events were grouped to obtain their composite fault-plane solutions which indicate left-lateral strike-slip faulting along the NNE faults and normal faulting in the NW direction. Faults observed in the LANDSAT imagery match with these trends.
Vertical deformation at Middleton Island, Alaska
Authors: Prescott W. H. , Lisowski M.
Published: June 2021

abstract

Analysis of leveling data from Middleton Island in the Gulf of Alaska confirms our earlier observation of high rates of vertical deformation. Although the island is only 8 km long, the deformation pattern is quite complex. The north end of the island is falling relative to the remainder at a rate of 3 mm/yr. This rate of movement is decreasing exponentially with a time constant of about 8 yr. In addition, a short level line across the island indicates some tilting down in the direction N50°W. This deformation also exhibits a declining rate.

The direction of all deformation appears to be controlled by the strike of the Aleutian Trench or, equivalently, by the axis of the 1964 Alaska earthquake deformation field. The deformation at Middleton Island is inconsistent with motion in the direction of the Minster-Jordan relative plate motion vector.

The deformation is inferred to be a long-lived aftereffect of the 1964 earthquake.
Pre-, co-, and postseismic strain changes associated with the 1952ML= 7.2 Kern County, California, earthquake
Authors: Dunbar W. Scott , Boore David M. , Thatcher Wayne
Published: June 2021

abstract

Triangulation surveys carried out in the vicinity of the White Wolf Fault in 1932, 1952, 1953, and 1963 are used to delineate the strain changes preceding, accompanying, and following the 1952 earthquake. The strain rate (engineering shear) during the preseismic interval (1932 to 1952) was 0.36 ± 0.10 μstrain/yr and was nearly uniform across the 70-km-long triangulation arc, with the plane of maximum left-lateral shear oriented N44° ± 7°E, nearly parallel to the White Wolf Fault. The coseismic observations (1952 to 1953), supplemented by leveling data, are matched using a dislocation model with the following characteristics

Dip = 60°SE

Strike = N50°E

Length = 70 km

Left-Lateral Strike-Slip = 2.4 ± 0.1 meter (m)

Reverse Dip-Slip = 1.9 to 0.6 m (decreasing to the NE)

Seismic moment ≧ 0.9 × 1027 dyne-cm.

The data also require most of the slip to have occurred below ∼5 km (5 to 20 km in our model), on roughly the southwest half of the fault, with the slip occurring at shallow depths to the northeast. The postseismic triangulation data (1953 to 1963) indicate that the average shear strain rate in the 10 yr following the earthquake (0.80 ± 0.20 μstrain/yr) was about twice that during the 20 yr preceding it. The postseismic strain changes were concentrated closer to the fault than those determined for the preseismic time interval, and the 1953 to 1963 data are explained well by episodic postseismic slip of about 2 m (left-lateral strike-slip) occurring on the down-dip extension of the coseismic fault plane.
The Suez Crisis of 1956 and 1957 in West German Television News
Authors: Lehnert Sigrun
Published: June 2021

From the mid-1950s onwards, the number of television viewers in West Germany increased rapidly and television became the “window to the world” for many people. Through audio-visual reporting the people were informed so that they could feel save as they know what had happened in the world, especially in times of the Cold War. The Suez Crisis of 1956/1957 was one of the Cold War conflicts that television was able to report on continuously and thus demonstrate its advantages. The Suez Crisis has to be considered not only in the context of the larger, geopolitical conflict between East and West, but also in a decolonization context, and it affected the Federal Republic of Germany (FRG) in several ways. The daily newscast Tagesschau, and the weekly compilation Wochenspiegel was able to convey images from a distant region with high actuality. In the beginning, Tagesschau used material from the cinema newsreel and followed its style, but the news editors very soon developed their own strategies of modern reporting. This article outlines the style of West German television news in the 1950s as well as the routines and ways of reporting, which continue in news production today.
Study of keratomycosis at a tertiary care teaching hospital
Authors: Gayathri Veluri , Jeswin Ami
Published: June 2021

Corneal infections are one of the leading causes of ocular morbidity and blindness world-wide. If normal defence mechanisms of the eye are compromised, almost any microorganism can invade the cornea. It is important to know the exact aetiology of corneal ulcer to institute appropriate therapy in time, least serious consequences may follow.  

To isolate and identify the fungi from corneal scrapings of suspected keratitis patients. 

A prospective study of Fungal keratitis was conducted at Al-Azhar Medical College & Super Speciality Hospital in Thodupuzha, Kerala a tertiary care hospital with a capacity of 650 beds. The duration of the study was two years from January 2018 to January 2020. Patients with suspected fungal corneal ulcers presenting in the Out-Patient Department (OPD) of Ophthalmology were investigated for fungal etiology in the Department of Microbiology were included in this study. Each patient was examined with slit lamp. Data collected from history given by patient and patient examination. Using standard techniques. The specimens collected were then smeared on two slides, which were stained with Gram stain (for bacterial keratitis) and 10% potassium hydroxide preparation (for fungal keratitis) studied under light microscope.

Of the 866 patients with corneal ulcer investigated, 83 cases with fungal and 36 with bacterial aetiology was identified. Males were more commonly affected and were mostly in the age group of 31-40 year. It was seen that trauma was the most common predisposing factor especially in the agriculturists and the farmers. Among the identified fungi, most were hyaline. Of the 83 positive specimens, the most frequent agent isolated was Fusarium species in 31 (37.3%) cases. 23 (27.7%) was the second most common followed by , ., . Candida albicans were 5 (6%) followed by 1 (1.2%).

Fungal Keratitis is a serious problem usually following corneal trauma, it requires rapid detection and identification of fugal agents for treatment to prevent disastrous consequences.
A comparative study of Widal test with blood culture in the diagnosis of typhoid fever in febrile patients
Authors: Choubey Pooja
Published: June 2021

Typhoid fever is a major health problem in developing countries and its diagnosis on clinical ground is difficult. Diagnosis in developing countries including Madhya Pradesh is mostly done by Widal test. However, the value of the test has been debated. Hence, evaluating the result of this test is necessary for correct interpretation of the result.

A comparative study of Widal test with blood culture in the diagnosis of typhoid fever in febrile patients.

Blood samples were collected from 62 febrile patients with symptoms clinically similar to typhoid fever and visiting red cross Hospitals at bhopal from mid May 2018 to August 2018. Blood culture was used to isolate S.typhi and S.paratyphi. Slide agglutination test and tube agglutination tests were used for the determination of antibody titer.

Statistical analysis used: Data analysis by IBM SPSS Statistics 20

10 participants were females and 22 were males in blood culture and 20 were positive, 12 were negative. Total 62 cases of S. typhi were identified with the total prevalence of typhoid fever. The total number of patients who have indicative of recent infection by either of O and H antigens.

Total 62 cases of S. Typhi or paratyphi were identify with the total prevalence of typhoid fever.Widal test is 30 patients were observed and blood culture were observed 32 patients.
Corynebacterium jeikeium - An unusual cause of meningoencephalitis in a patient with HIV and tuberculosis
Authors: Sankar Sastry Apurba , Shanmugam Lakshmi , Gunalan Anitha , Bhaskar Maanasa , Ravi Pradeep , Sivaradjy Monika , Priyadarshi Ketan
Published: June 2021

Coryneforms other than are often ignored when isolated from clinical laboratories as in most instances they represent the normal commensals of skin. was initially considered only as commensal, later it was identified as the causative agent for severe sepsis in immunocompromised patients. Here, we present a case of meningoencephalitis caused by in a 30 year old adult male with HIV and tuberculosis co-infection. Serial cerebrospinal fluid from external ventricular drainage had grown which was identified by automated MALDI-TOF system which aided in the timely diagnosis and prompt management of the patient.
Do You Want to Become a Teacher?: Career Choice Motivation Using Behavioral Strategies
Authors: Ajzenman Nicolás , Elacqua Gregory , Hincapié Diana , Jaimovich Analia , López Bóo Florencia , Paredes Diana , Román Alonso
Published: June 2021

Qualified teachers are a fundamental input for any education system. Yet, many countries struggle to attract highly skilled applicants to the teaching profession. This paper presents the results of a large-scale intervention to attract high performing high-school students into the teaching profession in Chile. The intervention was a three-arm email campaign which made salient three types of motivations typically associated with the teaching profession: intrinsic/altruistic, extrinsic, and prestige-related. The objective was to identify which type of message better appealed to high performing students to nudge them to choose a teaching major. The “intrinsic” and “prestige” arms reduced applications to teaching majors among high performers, while the “extrinsic” arm increased applications among low performers. A plausible interpretation could be that the “intrinsic” and “prestige” messages made more salient an issue that could otherwise be overlooked by high performing students (typically from more advantaged households), negatively impacting their program choice: that while the social value of the teaching profession has improved, it still lags behind other professions that are valued more by their families and social circles. In turn, the “extrinsic” arm made salient the recent improvements in the economic conditions of the teaching profession in Chile, thus appealing to low performing students who in general come from disadvantaged families and for whom monetary incentives are potentially more relevant. These results emphasize the importance of having a clear picture of the inherent motivations that could influence individuals career choice. Making salient certain types of motivations to the wrong target group could lead to undesired results.
Ragweed pollen induces allergic conjunctivitis immune tolerance in mice via regulation of the NF-κB signal pathway
Authors:   Department of Ophthalmology, Fourth Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China;, Bai Meng-Tian , Hu Zhu-Lin ,   Department of Ophthalmology, Fourth Affiliated Hospital of Kunming Medical University, Kunming 650032, Yunnan Province, China
Published: June 2021

AIM: To investigate the feasibility and mechanism of immune tolerance in allergic conjunctivitis.
METHODS: The allergic conjunctivitis immune tolerance mice model was established by ragweed pollen (RW) and the related cytokines were detected. The mice were divided into 9 groups and the maslinic acid (MA) or PBS were given for different group after modeling. The expression levels of chemokine ligand 5 (CCL5) and P-65 in the conjunctival tissue were analyzed by immunohistochemistry, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. The percentage of interleukin-17 (IL-17) and CD4+CD25+ in the splenocyte supernatant was analyzed by flow cytometry. Furthermore, the serum and splenocyte supernatant concentration of total-IgE, interleukin-10 (IL-10), and IL-17 was analyzed by enzyme linked immune response (ELISA).
RESULTS: After the model was established, symptoms of conjunctivitis were alleviated, the level of P-65, CCL5, IL-17, and total-IgE was raised, while the expression of IL-10, CD4+CD25+ was decreased. This result fully demonstrated that a typical IL-17/regulatory-T-cells (Treg cells) imbalance and NF-κB activation. When the NF-κB signal pathway was suppressed, it showed that there was a further relief of conjunctivitis in mice. At the same time, the expression of total-IgE, IL-17, and CCL5 was decreased and the expression of anti-inflammatory factor (IL-10, CD4+CD25+) was increased.
CONCLUSION: In the state of immune tolerance, symptoms of conjunctivitis in mice are alleviated, the Th-17 cells of allergic conjunctivitis mice are inhibited, and Treg cells activity is enhanced.
Inhibition of TGF-β2-induced migration and epithelial-mesenchymal transition in ARPE-19 by sulforaphane
Authors:   Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China, Huang Yan-Bing , Zheng Hui ,   Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China, Yang Xiu-Xia ,   Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China, Yang Cheng-Cheng ,   Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China, Liu Ye ,   Department of Pathology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China, Liu Yang ,   Department of Ophthalmology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, Guangdong Province, China
Published: June 2021

AIM: To investigate the effects of sulforaphane (SFN) on transforming growth factor (TGF)-β2 stimulated migration and epithelial-mesenchymal transition (EMT) in ARPE-19 cells.
METHODS: ARPE-19 cells were cultured in the presence or absence of SFN or TGF-β2. SFN toxicity was assessed by performing a lactate dehydrogenase assay (LDH) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays, and cell migration was evaluated by Transwell migration assay. Actin stress fiber formation in ARPE-19 cells was determined using immunofluorescence analysis. Immunoblotting analysis was used to determine fibronectin and α-smooth muscle actin expressions along with the degree of Smad and Akt phosphorylation.
RESULTS: SFN inhibited ARPE-19 migration. Additionally, SFN attenuated TGF-β2-induced appearance of actin stress fibers as well as fibronectin and α-smooth muscle actin expressions in these cells. SFN also hindered the TGF-β2-stimulated phosphorylation of Smad2, Smad3, and Akt. SFN showed no cytotoxicity towards ARPE-19 cells.
CONCLUSION: SFN inhibits TGF-β2-stimulated migration and EMT in ARPE-19 cells, probably by preventing the establishment of actin stress fibers and Akt and Smad2/3 signaling.
Comparison of IOL-Master 700 and IOL-Master 500 biometers in ocular biological parameters of adolescents
Authors:   Department of Ophthalmology, the First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China, Shi Qiang , Cheng Yu-Hong ,   Department of Ophthalmology, the First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China, Pei Cheng ,   Department of Ophthalmology, the First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi’an 710061, Shaanxi Province, China
Published: June 2021

AIM: To compare the differences and consistency of IOL-Master 700 biometers applying swept optical coherence tomography with the conventional IOL-Master 500 applying partial coherence interference in terms of the ocular biological parameters in adolescents with ametropia.
METHODS: A total of 110 adolescents (110 eyes) with ametropia were collected, including 55 males and 55 females; age 10.69±2.81y. Ocular biological measurements were taken by IOL-Master 700 and IOL-Master 500 respectively to obtain biological parameters including axial length (AL), mean corneal anterior surface keratometry (Km), anterior chamber depth (ACD), and horizontal corneal diameter (WTW). Paired t-test was used to compare the differences between the two instruments. The intra-group correlation coefficient (ICC) and the Bland-Altman analysis were used to evaluate the consistency of parameter measurements between the two instruments for the four biological parameters.
RESULTS: Statistical analysis showed that there was no significant difference in the Km value measured by IOL-Master 700 and IOL-Master 500 (t=-1.644, P=0.116). The average differences of the AL, ACD, and WTW distances between the two instruments are 0.028, 0.101 and 0.064 mm respectively, and the differences are statistically significant (t=2.644, 12.505, 3.911, P<0.001). The consistency study results indicated high correlation in the measurement of AL, Km, ACD and WTW between the two instruments (ICC=0.994, 0.873, 0.927, 0.912).
CONCLUSION: The novel biometric instrument IOL-Master 700 makes no difference with IOL-Master 500 in the measurement of Km. There are some differences in the values of AL, ACD, and WTW. However, the two instruments show good consistency in these four biological measurements. The measured values of Km are interchangeable between the instruments. These two types of biometrics can be used as mutual reference in consideration of that the differences in AL, ACD, and WTW measurements are not sufficient to produce clinically meaningful differences.
Atherogenic indices in non-arteritic ischemic optic neuropathy
Authors:   Department of Ophthalmology, Ondokuzmayıs University Hospital, Atakum 55200, Samsun, Turkey, Kocak Nurullah , Turunc Mustafa ,   Department of Ophthalmology, Ondokuzmayıs University Hospital, Atakum 55200, Samsun, Turkey, Bayrambas Merve ,   Department of Ophthalmology, Çankırı State Hospital, Çankırı 18100, Turkey, Eraydin Bilge ,   Department of Ophthalmology, Erbaa State Hospital, Tokat 60500, Turkey, Güngor Inci ,   Department of Ophthalmology, Ondokuzmayıs University Hospital, Atakum 55200, Samsun, Turkey
Published: June 2021

AIM: To evaluate the atherogenic indices and the relationship with visual acuity and bilateral sequential involvement in patients with non-arteritic ischemic optic neuropathy (NAION).
METHODS: A total of 65 patients with NAION and 48 age-sex matched healthy individuals were included in this retrospective study. The demographic characteristics and laboratory findings of the patients and control subjects were obtained from the electronic medical records. The atherogenic indices were calculated using the lipid parameters. The association between visual acuity, bilateral sequential involvement, and atherogenic indices was investigated.
RESULTS: The mean age was 63.8±12.5y in the NAION group and 64.7±10.1y in control group (P=0.707). Although there were no significant differences in terms of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) between two groups (P=0.089, 0.091), all the non-traditional serum lipid ratios were significantly higher in NAION group (P<0.05). In the NAION subgroup analysis, with visual acuity≤20/200 had higher TC/high-density lipoprotein cholesterol (HDL-c), LDL-c/HDL-c, and non-HDL-c/HDL-c values than the patients in the NAION group with visual acuity >20/200 (P=0.032, 0.025, 0.032, respectively). The values for the atherogenic indices were higher in NAION patients with bilateral sequential involvement in comparison to those with unilateral involvement (P=0.271, 0.127, 0.197, 0.128, 0.127, respectively).
CONCLUSION: The study reveals a relationship between NAION and the non-traditional lipid ratios. Atherogenic indices may predict the visual loss severity and second eye involvement in patients with NAION.