bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the English as a medium of instruction as a pedagogical technology in university educational activities
Authors: Litovchenko V I , Shmeleva Zh N
Published: December 2020

In 2020 the world has faced the pandemic situation with COVID-19 that caused a vast amount of challenges for many spheres of human life including the system of higher education. Students and faculty members of higher educational institutions were forced to critically change their learning style using distant technologies, Zoom and Moodle platforms which was not always perceived positively. Nevertheless, the existing situation of restrictions revealed larger opportunities for an increase in English learning and education through English. One of the most popular directions is English as a medium of instruction (EMI). The international character and popularity of English are undisputable, that’s why it is widely used to teach specific subjects in non-native English-speaking countries. Institutions of higher education all over the world start offering educational programs in English for disciplines in different training directions whether it is management or agriculture. The article aims at focusing on implementing EMI in two institutions of higher education in the Siberian Federal District where faculty members teach in English within modern European internationalization trend of offering courses and Master degree programs in English. The authors make an attempt to reveal advantages and disadvantages of EMI implementation and introduction. Based on the works and experiments of foreign scientists and having some experience in using English as a medium of instruction, the authors draw the conclusion that the EMI implementation in its pure form has certain imperfections. Consequently, the authors suggest the set of measures to make this process more effective: first, to search for opportunities for the foreign language additional study by students in the Bachelor’s degree, via elective courses, or Language Learning Business Centers; secondly, to use the so-called CLIL-ised EMI; thirdly, to provide faculty members with English-training courses and ensure the access to the resources for the development of methodological materials.
Implementing e-learning with personalized trajectories
Authors: Russkikh P A , Kapulin D V , Moor I A
Published: December 2020

The article presents the author’s approach to building adaptive e-learning courses, an example of the Moodle distance learning system. The introduction of adaptive e-learning courses into the educational process improves the quality of the educational process. The main advantage is the individualization of the educational process for each student. In addition, students’ independent work will acquire a directional character with minimal teacher involvement. The developed course allows for statistical processing of learning outcomes and tracking the dynamics students’ performance as they study the discipline.
The use of digital technologies in the professional training of cadets
Authors: Eltemerov Aksar A , Fedorova Svetlana N
Published: December 2020

The modern education system should provide the society with a confident transition to the digital era. Digitalization contributes to the immediate response to any emergency. Consequently, the introduction of digital technologies plays an important role in the training of rescuers. The significance and ways of introducing digital technologies in the process of professional training of universities teaching fire-safety specialists have been analyzed in the article. It is emphasized that the system of training future specialists requires the use of innovative methods of training. The experience of leading universities is analyzed, where various training programs, electronic textbooks and simulation facilities are used. The role of pedagogical technologies based on students’ own activity, interactive communication, teamwork, group and individual reflection is growing. At the stage of the specialist’s training, the situation of possible emergency situations is simulated and the student is placed in conditions in which the personal qualities necessary for professional activity will be developed. The variety of forms for organizing educational activities in the conditions of digitalization will increase significantly, if they acquire a dynamic character (shift groups, spatially distributed training teams, various scenarios of rapid transition from group to individual activities and vice versa).
Natural-scientific cases as an instrument for assessment of logical thinking
Authors: Solodikhina M V , Odintsova N I , Odintsova E E
Published: December 2020

Logic is the basis of both critical thinking and the scientific method of nature cognition, so it can be effectively developed when studying natural science disciplines. The existing tools for assessing logical thinking require a lot of time to work with materials that are barely related to natural science. Instead, it is proposed to use natural science cases, which can serve simultaneously as both a development tool and a diagnostic tool for logical thinking. The aim of the study was to test the criterion validity of such cases for assessing logical thinking. The study involved students of the Master’s program “Modern Natural Science” of the Moscow Pedagogical State University and the bachelor’s program of the Peoples’ Friendship University of Russia. The diagnostic results showed a high degree of correlation between the results obtained by the subjects when solving cases with the results of four independent assessments: Test of Logical Thinking, the Group Assessment of Logical Thinking, solving a set of logical problems and expert assessment of students’ work on a natural science project.
Modern approaches to polytechnic education
Authors: Likhacheva O N , Shilovich O B , Tymchuk E V , Shiyan S I , Pupkova Yu V , Kostenko R V
Published: December 2020

In modern society there is a growing demand in high-quality specialists of engineering sphere as a result of science, technique and technology development. In this context a new concept of polytechnic education is important, in which there is a special significant place for the humanitarian segment. Mastering the above mentioned competences implies a high cultural and educational level of a future specialist of engineering sphere. The aim of this article is to study the modern condition of humanitarian subjects in a technical university and offer the ways of solving the existing problems by means of modeling the academic process in a new demanded context of a high school. The actuality of this article consists in an insufficient study of the humanitarian segment and a growing need in changing approaches to its studying in a polytechnic university.
Pre-processing of data on the behavior of users of the Moscow Electronic School service
Authors: Frolov Y V , Bosenko T M
Published: December 2020

The article presents the results of preliminary processing of data on the behavior of users of the Moscow Electronic School with a volume of about 50 thousand observations. The relevance of the study is due to the increase in the volume of distance and mixed education in the context of digitalization of space. The aim of this study was to identify groups of teachers (users) exhibiting differing behaviors when interacting with educational content on the Moscow Electronic School platform. According to the results of the study, the relationships between the behavioral parameters of users were determined and 5 behavioral types of the Moscow Electronic School users were identified, which will further allow using this approach in increasing the efficiency of the Moscow Electronic School platform as a recommendation system.
Impact of digitalization on the pedagogical aspects of traditional education
Authors: Yarychev N U , Mentsiev Adam U
Published: December 2020

Traditional education is focused on sources such as teachers, print media, and school. The only way a learner can reach the information source by enrolling with schools, libraries, and teachers. By the majority of people, information was not easily accessible. In case if you have access to the data, it might not be the latest. In the modern era, everyone wants access to the latest information, and the advancement in technology has made it possible. Digitalization has given us many learning opportunities.
Rational and semi-rational solutions to the asymmetric Nizhnik–Novikov–Veselov system
Authors: Guo Lijuan , He Jingsong , Mihalache Dumitru
Published: December 2020

In this paper, we use the binary Darboux transformation technique to derive an uniform mathematical expression of all kinds of solutions to the (2 + 1)-dimensional asymmetric Nizhnik–Novikov–Veselov system. For the same seeding solution, a family of eigenfunctions associated with the same eigenvalue is obtained, which is used to construct rational and semi-rational solutions. Interestingly, there exists a category of localized rational solutions that show nontrivial interaction scenarios, namely the pulses undergo a scattering process after the head-on collision. The semi-rational solutions are characterized by two generic evolution scenarios: fission and fusion processes. We also find a subclass of dark rogue waves, namely trains of line solitons that evolve to significant strongly localized transient waves.
Pressure and flow statistics of Darcy flow from simulated annealing
Authors: Westbroek Marise J E , King Peter R , Vvedensky Dimitri D , Schwede Ronnie
Published: December 2020

The pressure and flow statistics of Darcy flow through a three-dimensional random permeable medium are expressed as a path integral in a form suitable for evaluation by simulated annealing. There are several advantages to using simulated annealing for this problem: (i) any probability distribution can be used for the permeability, (ii) there is no need to invert the transmissibility matrix which, while not a factor for single-phase flow, offers distinct advantages for multiphase flow, and (iii) the action used for simulated annealing, whose extremum yields Darcy’s law, is eminently suitable for coarse graining by integrating over the short-wavelength degrees of freedom. We show that the pressure and flow statistics obtained by simulated annealing are in excellent agreement with those obtained from standard finite-volume calculations.
Mechanical properties of rubber aggregates based geopolymer concrete - A review
Authors: Yeluri Sesha Choudary , Yadav Nishant
Published: December 2020

Aggregates are the furthermost vital components of concrete, but there is a need for replacement of these natural resources due to the insufficient availability of the materials. To overcome the difficulty of materials and to develop sustainable concrete, much research has been conducting to date. The replacement of aggregates wholly or partially is one of the best alternatives to this problem. To develop sustainability in concrete waste materials that are causing depletion to the environment are used as alternative materials. Rubber tire waste is one such material which is causing a lot of greenhouse gas emission. This paper reviews the use of rubber tire waste as aggregates in geopolymer concrete which shows the effect of various sizes of rubber, untreated and treated rubber aggregate on various properties such as Fresh Properties where flow values of mortar reduced with escalation in the rubber and workability of the mortar and concrete increased. Nevertheless, the Mechanical Properties shows a decrement in compressive strength, and tension properties show an increment. There is a significant amount of increment in the possessions of mortar and concrete after the crumbed rubber treated. The loss of strength for the small amount of replacement of rubber, which is 5-10% shows the strength higher than the standard concrete. The outcomes show that the custom of the rubber in concrete primes to a substantial amount of strength loss, but the addition of mineral admixture and superplasticiser helps us to achieve the geopolymer mortar and concrete applications in the field of construction.
Comparative study of conventional bricks with Padobe
Authors: Yugasini S , Uma Maguesvari M , Muthaiyan P , Ammaiappan M
Published: December 2020

In this study the properties of conventional brick compared with the brick made with Padobe. Padobe is a mixture of clay, paper pulp and water. Here we have added GGBS into this mixture. A composite material of the brick that having moderate physical and mechanical characteristics, which mainly helps the business industry like as construction. The addition of paper pulp and GGBS in clay helps in the reduction of environmental issues and cost of construction. Paper pulp is kept as constant and the other materials like clay and GGBS is done with various proportions such as 70:20:10, 60:3:10, 50:40:10 and 40:50:10. An experimental study has been conducted for optimize the mix of Padobe depending on the compressive strength.
Understanding of Non-Value Added Overtime in Manufacturing Operations
Authors: Abdul Rasib A. H. , Musazali M.
Published: December 2020

The manufacturing industry plays a crucial role in the production process to meet the demands of the market and to raise the standard of living recently. Nevertheless, one of the most common issues associated with the industry is unnecessary overtime. Overtime has produced a variety of negative consequences on production output. This paper aims to identify the various causes of unnecessary overtime, and the causes have been categorised through the seven wastes of lean manufacturing. This paper also focuses on unnecessary overtime occurred in industries. The method used in this paper is by reviewing the relevant literature from conference papers and journal publications, including the International Journal of Scientific and Technology Research, Journal of Advanced Manufacturing Technology, and International Journal of Engineering and Technology, amongst many others. Finally, the critical components of NAO have been finalised according to the necessary scopes of operation, which considered as factors which are pre-production, in-production, and post-production. Based on the final critical components, there were two critical sub-factors in pre-production components, six critical sub-factors in-production elements, and five critical sub-factors post-production components.
Smart Solar Panel using Light Dependent Resistors
Authors: Karthik S , Vivek Karthick P , Thirrunavukkarasu R R , Satheesh Kumar S , Selvakumar D
Published: December 2020

Solar energy is gradually approaching a most important form of renewable energy. Using solar tracker, additional energy can be produced, since the solar plate can maintain a vertical angle to the sunrays. Given the substantial initial expense of setting up the tracking device, there are less expensive alternatives that have been suggested over period. This paper addresses the strategy and development of solar tracking device prototype which has one axis of independence. Here, Light Dependent Resistors (LDRs) are used to sense the sunlight.
A Vehicle Accident Detection and Driver Surveillance
Authors: Selvakumar D , Ganesh Prabhu S , Karthik S , Karthik V , Shivaa T R , Vaigunthan H , Gowtham J
Published: December 2020

Perpetual increase in the number of deadly traffic accidents around the world are often considerablyminimized if contemporaryproficiency is integrated inside of the car towards observe the fitness of the driving force onconsistentinterims over the vehicle runningand precautionary measures predictably taken for the safety of all anxiouspersonnel, either within the vehicle or outside. The Raspberry Pi controller constantly records every one of the parameters of the vehicle based on the heartbeat, drowsiness and the level of alcohol consumption of the driver, for anticipation and recognition of mishap. In the unfortunate case of occurrence of an accident, the details and location of the vehicle is intimated to the emergency contacts via message immediately in order to seek first aid so as to prevent the avoidable loss of lives.
Gamut sensing in cognitive radio networks: A brief survey by using the concept of design thinking
Authors: Ranjani K , Rasheedha A , Suresh Kumar R
Published: December 2020

With an unprecedented intensification in mobile customer and mobile multimedia services radio telecommunications in general the need for more bandwidth is escalating every day. To accommodate such a large amount of wireless technologies huge bandwidth is needed. This necessitated the need to address spectrum scarcity as the spectrum is a scarce resource. But it is evident from many gamut measurement studies that much of the gamut is used in an inefficient way and its fullest potential is not exploited. This gives rise to the technology of cognitive radio networks. Having said this let us try to brief the operation of intelligent radio networks (CRN). The overview of this paper presents a detailed account of the concept of gamut sensing which a crucial step in CRN is. We address the different performance metrics related to spectrum sensing and present a brief idea of some of the research activities that are related to spectrum sensing by different researchers.
Analysis of Dynamic Frequency Reuse Techniques in LTE – A Cellular Network
Authors: Karthika S , Indumathi P
Published: December 2020

Inter-cell Interference (ICI) is a significant obstacle which is degrading the efficiency of mobile cellular networks particularly for end users. Frequency reuse is an ICI synchronization technique which helps to mitigate ICI by assigning dissimilar frequency reuse factors on the basis of its position to User equipment (UE). This paper proposes a Self-organized resource allocation (SORA) framework that chooses the reuse factors randomly. The output of this strategy is configured using MATLAB and correlated with numerous reuse factor combinations. Results from simulation show improved efficiency for Cell Edge Users (CEU).
The effect of pre-heat and post-heat treatment on the hardness and blackening process of electroless NiP deposits on titanium alloy
Authors: Alhaji A , Sadeghi B , Kamali S
Published: December 2020

The black coatings were fabricated via electroless NiP deposits on Ti-6Al-4V alloy substrate with heat-treatment and blackening process. Two types of coatings were obtained: coatings with heat-treatment after blackening and coatings with blackening after haet-treatment. After parameter optimization, the temperature and pH of the solution were adjusted to 85 °C–95 °C and 4.3–4.7, respectively. The substrate was coated after the addition of modifying components to the solution. After refluxing the samples, the blackening process was done for 40 s in nitric acid (9molar). An SEM-EDS analyze used to assess the morphology and chemical composition of the coating. Moreover, adhesion strength and optical absorptance of the coating were measured by Pull Of test and Shimadzu UV-3100 analysis, respectively. The optical absorptance was measured by 0.89 and 0.95, respectively, for Oxalic acid and Nitric/Flouridric acid pretreated samples. Results showed that heat-treatment after blackening causes coating with higher micro-hardness and optical absorption. The blackened electroless NiP coating on Ti substrate with the heat-treatment of 4 h after the blackening process provided high solar absorption of 0.99, which is exceptionally suitable as a solar absorber coating for space and allied applications.
Multi–layer graphene folds supported on a substrate: a variational model
Authors: Aljedani Jabr , Chen Michael J , Cox Barry J
Published: December 2020

A mathematical model is developed to study the folding behaviour of multi–layer graphene sheets supported on a substrate. The conformation of the fold is determined from variational considerations based on two energies, namely the graphene elastic energy and the van der Waals (vdW) interaction energy between graphene layers and the substrate. The model is nondimensionalized and variational calculus techniques are then employed to determine the conformation of the fold. The Lennard–Jones potential is used to determine the vdW interaction energy as well as the graphene–substrate and graphene–graphene spacing distances. The folding conformation is investigated under three different approximations of the total line curvature. Our findings show good agreement with experimental measurements of multi–layer graphene folds from the literature.
Electrochemical modification at multiwalled carbon nanotube electrodes with Azure A for FAD- glucose dehydrogenase wiring: structural optimization to enhance catalytic activity and stability
Authors: Tsujimura Seiya , Tanaka Shunya , Gross Andrew , Holzinger Michael
Published: December 2020

Electrochemical grafting is a suitable technology for fabricating electrode surfaces with new chemical functionalities whilst maintaining the bulk properties of the electrode, and electrochemical amine oxidation and diazonium salt reduction are two widely used techniques to achieve this end. Herein, we report the electrochemical reductive grafting of Azure A onto multiwalled carbon nanotube (MWCNT) electrodes for the efficient wiring of flavin adenine dinucleotide (FAD) dependent glucose dehydrogenase. The diazonium salt of Azure A is formed in situ and subsequently grafted onto the electrode surface through electrochemical reduction. The formal potential of the resultant Azure-A-modified electrode shifted to −0.05 V vs. Ag/AgCl upon radical coupling to the MWCNT electrode. Electron transfer from FAD buried in the protein shell to the electrode via Azure A was then observed in the presence of glucose in the buffer solution. This study focused on the important effect of CNT mass loading on Azure-A loading as well as bioelectrocatalytic activity and storage stability. The three-dimensional porous structure of the MWCNT electrode was determined to be favorable for the immobilization of flavin adenine dinucleotide dependent glucose dehydrogenase and efficient electron transfer via the Azure-A functionalities. The optimized 300 µg CNT-loaded modified electrode on glassy carbon (3 mm diameter) retains its initial activity for 3 d and 25% of its initial activity after 10 d. Furthermore, we show that grafted Azure A is stably immobilized on the MWCNTs for 1 month; therefore, the limiting stability factor is enzyme leaching and/or deactivation.
Enhancement of the conversion of mechanical energy into chemical energy by using piezoelectric KNbO3−x with oxygen vacancies as a novel piezocatalyst
Authors: Tan Hong-Yi , Zhan Liang , Yan Chang-Feng , Abeykoon Lahiru K , De Silva Nuwan L , Bandara Jayasundera
Published: December 2020

Synthesis of new piezoelectric materials to harness the vibrational and thermal energies may contribute to solve the current increasing energy demands. KNbO3 is a known piezo- electric material that exhibits poor piezocatalytic activity owing to the scarcity of charge carriers in it. In order to enhance the charge carrier density in KNbO3, extra electrons were added to KNbO3 lattice. Extrinsic piezoelectric KNbO3−x having extra electrons in the lattice was synthesized via the reaction between Nb2O5 and KBH4 at elevated temperatures. The KNbO3 nanostructures formed at 450 and 550 °C contained feebly piezoelectric KNbO3−x/Nb2O5−x and piezoelectric KNbO3−x respectively. The enhanced piezocatalytic activity of KNbO3−x is demonstrated by the production of hydrogen from water by harnessing the mechanical vibrations and the observed hydrogen production rates are 0.05 and 3.19 ml h−1 g1 for KNbO3−x/Nb2O5−x and KNbO3−x respectively. The enhanced piezocatalytic activity of KNbO3−x can be attributed to the enhancement of the charge carrier density resulting from the creation of oxygen vacancies in KNbO3 that lead to enhancing the electronic conductivity as well as charge carrier separation. It is demonstrated that the piezocatalytic activity can be boosted by augmenting the charge carrier density in piezoelectric materials by synthesizing them under highly reducing reaction conditions.
Effect of nanoinclusions on the lattice thermal conductivity of SnSe
Authors: Gupta Raveena , Bera Chandan
Published: December 2020

We theoretically investigate the effect of nanoparticle(NP) inclusion on the lattice thermal conductivity (κ

l
) of SnSe matrix. The theoretical approach involves the prediction of κ

l
by varying the radius (R), density (D
1), and volume fraction (ε) of NP in SnSe matrix. NP has strong anisotropic effect on the lattice thermal conductivity reduction along the crystallographic direction. We observe the existence of an optimal NP volume fraction that minimizes the nanocomposite's thermal conductivity. At room temperature, this value is found to be ε = 0.317 for which lattice thermal conductivity reduces by 35% with NP (R = 5 nm) compared to pure SnSe. An enhancement in the figure of merit (ZT) around room temperature opens up new opportunities for thermoelectric power generation at moderate temperatures. Even larger enhancement is possible in polycrystalline SnSe which will be helpful for thermoelectric devices.
Metrics for Evaluating Polygenic Risk Scores
Authors: Baker Stuart G
Published: December 2020

There is growing interest in the use of polygenic risk scores based on genetic variants to predict cancer incidence. The type of metric used to evaluate the predictive performance of polygenic risk scores plays a crucial role in their interpretation. I compare 3 metrics for this evaluation: the area under the receiver operating characteristic curve (AUC), the probability of cancer in a high-risk subset divided by the prevalence of cancer in the population, which I call the subset relative risk (SRR), and the minimum test tradeoff, which is the minimum number of genetic variant ascertainments (one per person) for each correct prediction of cancer to yield a positive expected clinical utility. I show that SRR is a relabeling of AUC. I recommend the minimum test tradeoff for the evaluation of polygenic risk scores because, unlike AUC and SRR, it is directly related to the expected clinical utility.
Binaural Frequency Modulation Detection in School-Age Children, Young Adults, and Older Adults: Effects of Interaural Modulator Phase
Authors: Kane Stacey G. , Buss Emily , Grose John H.
Published: December 2020

Objectives:

The purpose of this study was to measure low-rate binaural frequency modulation (FM) detection across the lifespan as a gauge of temporal fine structure processing. Children and older adults were expected to perform more poorly than young adults but for different reasons.

Design:

Detection of 2-Hz FM carried by a 500-Hz pure tone was measured for modulators that were either in-phase or out-of-phase across ears. Thresholds were measured in quiet and in noise. Participants were school-age children (n = 44), young adults (n = 11), and older adults (n = 17) with normal or near-normal hearing.

Results:

Thresholds were lower for out-of-phase than in-phase modulators among all listening groups. Detection thresholds improved with child age, with larger effects of age for dichotic than diotic FM. Introduction of masking noise tended to elevate thresholds; this effect was larger for the dichotic condition than the diotic condition, and larger for older adults than young adults. In noise, young adults received the greatest dichotic benefit, followed by older adults, then young children. The relative effects of noise on dichotic benefit did not differ for young adults compared to young children and older adults; however, young children saw greater reduction in benefit due to noise than older adults.

Conclusion:

The difference in dichotic benefit between children and young adults is consistent with maturation of central auditory processing. Differences in the effect of noise on dichotic benefit in young children and older adults support the idea that different factors or combinations of factors limit performance in these two groups. Although dichotic FM detection appears to be more sensitive to the effects of development and aging than diotic FM detection, the positive correlation between diotic and dichotic FM detection thresholds for all listeners suggests contribution of one or more factors common to both conditions.
Rationing and triage of scarce, lifesaving therapy in the context of the COVID-19 pandemic: a cross-sectional, social media-driven, scenario-based online query of societal attitudes
Authors: Muensterer Oliver J. , Gianicolo Emilio A. , Paul Norbert W.
Published: December 2020

Background:

The recent coronavirus disease 2019 (COVID-19) pandemic made us aware that medical resources are limited. When demand for essential resources surpasses availability, difficult triaging decisions are necessary. While algorithms exist, almost nothing is known on societal attitudes regarding triage criteria.

Methods:

A cross-sectional survey was conducted via social media channels to query a broad sample of society. Participants were asked to make triage decisions in case-based vignettes, exploring a variety of factors. They also were asked to assess how sure they were about their decisions, and how such decisions should be reached.

Results:

The survey was completed in full by 1626 participants in April 2020. Median age was 39 years (range, 12–80 y), 984 (61%) were female. Patient prognosis, responsibility toward others, the absence of behavior-induced comorbidities, and younger age were rated the most important triage criteria, while participants found that insurance status, social status, and nationality should not play a substantial role. Ethics-committees and point systems were regarded potentially helpful for triage decision-making, while decisions based on order of presentation (first-come first-serve) or on a legal basis were viewed critically. Participants were least sure about their decision when dealing with age or behavior-induced comorbidities. Overall, women were surer about their decisions than men, participants of Christian faith were also more secure about their decision than atheists-agnostics.

Conclusions:

This study uses social media to generate insight into public opinion and attitudes regarding triage criteria and modalities. These findings may be helpful for the development of future medical triage algorithms.
Empirically derived back pain subgroups differentiated walking performance, pain, and disability
Authors: Butera Katie A. , Fox Emily J. , Bishop Mark D. , Coombes Stephen A. , George Steven Z.
Published: December 2020

Low back pain (LBP) is a leading cause of disability. However, the processes contributing to disability are not well understood. Therefore, this study (1) empirically derived LBP subgroups and (2) validated these subgroups using walking performance, pain, and disability measures. Seventy adults with LBP underwent testing for a priori determined sensory (temporal summation; conditioned pain modulation), psychological (positive affect/coping; negative coping), and motor (trunk extensor muscle activation during forward bending and walking) measures. A hierarchical cluster analysis determined subgroups that were then validated using walking (walking speed; Timed Up and Go [TUG]; TUG-Cognitive [TUG-Cog]; obstacle negotiation) and clinical (Brief Pain Inventory; Oswestry Disability Index; low back pressure pain threshold) measures. Two subgroups were derived: (1) a “Maladaptive” subgroup (n = 21) characterized by low positive affect/coping, high negative coping, low pain modulation, and atypical trunk extensor activation and (2) an “Adaptive” subgroup (n = 49) characterized by high positive affect/coping, low negative coping, high pain modulation, and typical trunk extensor activation. There were subgroup differences on 7 of 12 validation measures. The Maladaptive subgroup had reduced walking performance (slower self-selected walking speed, TUG completion, and obstacle approach and crossing speed) and worse clinical presentation (higher pain intensity, pain interference, and disability) (moderate to large effect sizes; P's < 0.05). Findings support the construct validity of this multidimensional subgrouping approach. Longitudinal studies are needed to determine whether the Maladaptive subgroup is predictive of poor outcomes, such as pain chronicity or persistent disability.
Health-Related Quality of Life in Patients With a Left Ventricular Assist Device (QOLVAD) Questionnaire
Authors: Sandau Kristin E. , Lee Christopher S. , Faulkner Kenneth M. , Pozehl Bunny , Eckman Peter , Garberich Ross , Weaver Carrie E. , Joseph Susan M. , Hall Shelley , Carey Sandra A. , Chaudhry Sunit-Preet , Schroeder Sarah E. , Hoffman Russell O. , Feldman David , Birati Edo Y. , Soni Meshal , Marble Judith Feighery , Jurgens Corrine Y. , Hoglund Barbara , Cowger Jennifer A.
Published: December 2020

Background

Patients with a left ventricular assist device are a unique and growing population who deserve their own valid, reliable instrument for health-related quality of life.

Objective

We developed and tested the Health-Related Quality of Life with a Left Ventricular Assist Device (QOLVAD) questionnaire.

Methods

In a prospective, descriptive study, patients from 7 sites completed the QOLVAD and comparator questionnaires. Construct validity was tested using confirmatory factor analysis. Convergent validity was tested using correlations of QOLVAD scores to well-established measures of subjective health status, depression, anxiety, and meaning/faith. Reliability and test-retest reliability were quantified.

Results

Patients (n = 213) were 58.7 ± 13.9 years old; 81.0% were male, 73.7% were White, and 48.0% had bridge to transplant. Questionnaires were completed at a median time of 44 weeks post ventricular assist device. The 5 QOLVAD domains had acceptable construct validity (root mean square error of approximation = 0.064, comparative and Tucker-Lewis fit indices > 0.90, weighted root mean square residual = 0.95). The total score and domain-specific scores were significantly correlated with the instruments to which they were compared. Internal consistency reliability was acceptable for all subscales (α = .79–.83) except the cognitive domain (α = .66). Unidimensional reliability for the total score was acceptable (α = .93), as was factor determinacy for multidimensional reliability (0.95). Total test-retest reliability was 0.875 (P < .001).

Conclusion

Our analysis provided initial support for validity and reliability of the QOLVAD for total score, physical, emotional, social, and meaning/spiritual domains. The QOLVAD has potential in research and clinical settings to guide decision making and referrals; further studies are needed.
Frequency-specific Electrocochleography and Traveling Wave Time as a Clinical Test for Menière's Disease
Authors: Conway Robert M. , Sugihara Eric M. , Lee David M. , Renker Jaclyn , Sioshansi Pedrom C. , Babu Seilesh C.
Published: December 2020

Introduction:

Menière's disease is a clinical entity with no definitive objective testing. It has been hypothesized that underlying endolymphatic hydrops stiffens the basilar membrane leading to increased speed of the acoustic stimulus, therefore traveling wave velocity has been proposed as an objective test to aid in the diagnosis. The objective of this study is to compare electrocochleography frequency-specific action potential latency, basilar membrane traveling wave time, and summation to action potential (SP/AP) ratio in Menière's and non-Menière's patients.

Methods:

Tympanic electrocochleography was performed with frequency-specific action potential latency time and SP/AP ratio recorded. Patient demographics, symptoms, audiogram data, AAO-HNS classification of Menière's disease, management interventions, and follow-up were recorded. Statistical analysis was performed to compare outcome measures across patient groups, demographics, and clinical data.

Results:

Ninety-one patients (182 ears) were included. There was a significant difference between a “definite” Menière's diagnosis and an “unlikely” or “probable” diagnosis by an average of 13 dB HL for the pure-tone thresholds at 250 Hz on the affected side (p = 0.006). There was no significant difference in pure-tone thresholds at any other frequency, AP latency at any frequency, or AP/SP ratio between the different Menière's classification groups.

Conclusions:

Our study fails to show significance of the traveling wave velocity as an objective test for Menière's disease. A significant correlation was found with low-frequency hearing loss between AAO-HNS Menière's classification groups.
Projected Cost Simulation in Chronic Ear Surgery: Cost in Chronic Ear Surgery
Authors: Tadokoro Kent , Bacalao Emily , Wozniak Amy , Kazemian-Marvi Elycia , Kircher Matthew L.
Published: December 2020

Objective:

To examine the projected healthcare costs of intact canal wall (ICW) and canal wall down (CWD) tympanomastoidectomy surgery and associated clinic follow-up visits in the management of chronic ear disease.

Study Design:

A review of literature was performed to analyze the cholesteatoma recidivism rates of ICW and CWD tympanomastoidectomy. Projected Medicare cost simulation applied to representative samples of patients undergoing otologic surgery and follow-up clinic appointments projected over 15 years with an annual 25% cholesteatoma recidivism rate.

Setting:

Tertiary academic center.

Patients:

Simulated patient population status postchronic ear surgery and representative follow-up clinic visits with or without in-office mastoid debridement procedures.

Interventions:

Therapeutic and rehabilitative.

Main Outcome Measures:

Healthcare cost.

Results:

Simulation of cost for chronic ear surgery with follow-up visits produced a higher mean cost for the ICW group compared with the CWD group at year 1 ($9112.06 versus $4954.16). However, CWD patients accumulate cost over time due to routine mastoid debridements. The accumulated costs for the CWD group surpassed the ICW group at 12.54 (CI: 12.02–13.11) years.

Conclusions:

Using a projected cost analysis model, intact canal wall tympanomastoidectomy incurs a larger upfront cost than the canal wall down technique. However, long-term mastoid cavity maintenance costs accumulate to surpass the intact canal wall group at 12.54 years.
Does Cognitive Dysfunction Correlate With Dizziness Severity in Meniére's Disease Patients
Authors: Dornhoffer James R. , Liu Yuan F. , Zhao Elise E. , Rizk Habib G.
Published: December 2020

Objective:

Characterize the relationship between cognitive dysfunction and the dizziness severity in Meniére's disease (MD) patients.

Study Design:

Retrospective review.

Setting:

University-based tertiary medical center.

Patients:

Three hundred patients were evaluated for MD from 2015 to 2019. Excluding comorbid or alternative vestibular disorders, 29 patients with definite MD and available pre- and postintervention data were included for analysis.

Interventions:

A progressive protocol of salt restriction, diuretics, steroid and/or gentamycin injection, and endolymphatic sac decompression for those refractory to medical therapy.

Main Outcome Measures:

Quality of life measured with the Dizziness Handicap Inventory (DHI) and cognitive function measured with the Cognitive Failures Questionnaire (CFQ). Pre- and posttreatment DHI and DHI subscale scores and change in these scores were correlated with pre- and posttreatment CFQ scores and change in CFQ with therapy.

Results:

Analysis showed a number of limited associations between improvement in DHI and improvement in CFQ. Total DHI scores failed to correlate scores or variation in scores with change in CFQ (p = 0.091 and p = 0.085, respectively). Improvement in the CFQ false-triggering domain was significantly associated with improvement in the DHI physical subscale (r = 0.491, p = 0.007) and was nonsignificantly associated with improvement in total DHI and DHI emotional subscale scores (r = 0.422, p = 0.016 and r = 0.399, p = 0.032).

Conclusions:

The DHI correlates with several pre- and posttreatment measures of cognitive dysfunction (CFQ) in MD patients. However, change in DHI and CFQ with therapy correlate poorly. Overall, the commonly used DHI may fail to adequately assess cognitive dysfunction in MD patients possibly due to factors not directly implicated by measures of vestibular dysfunction, such as central nervous system or cognitive dysfunction; however, the specific physical and emotional subscales may offer helpful insight into cognitive dysfunction change/improvement with treatment.
Migraine Features in Patients With Recurrent Benign Paroxysmal Positional Vertigo
Authors: Bruss David , Abouzari Mehdi , Sarna Brooke , Goshtasbi Khodayar , Lee Ariel , Birkenbeuel Jack , Djalilian Hamid R.
Published: December 2020

Objectives:

To identify migraine features present in a cohort of patients with recurrent benign paroxysmal positional vertigo (BPPV).

Methods:

Patients presenting with recurrent BPPV were surveyed. Recurrent BPPV was defined as three episodes or greater in 6 months before presentation, with resolution of symptoms after Epley maneuver. Current or past migraine headache (MH) diagnosis was made according to the International Headache Society guidelines.

Results:

Fifty-eight patients with recurrent BPPV with a mean age of 53.8 ± 17.4 years were included. Half (29 patients) fulfilled criteria for MH and half (29 patients) did not meet the criteria for MH (non-MH). No statistically significant difference was found in a majority of migraine-related symptoms between the MH and non-MH cohorts with recurrent BPPV. History of migraine medication usage (p = 0.008), presence of a weekly headache (p = 0.01), and duration of dizziness after positional vertigo (p = 0.01) were the only variables that were different on multivariate analysis between the MH and non-MH cohorts.

Conclusions:

Half of recurrent BPPV patients suffer from migraine headaches. The other half presented with migraine-related symptoms, but do not meet criteria for MH. The high comorbidity of MH in our recurrent BPPV cohort as well as the absence of a statistically significant difference in a majority of migraine-related features among patients who did and did not fulfill criteria for MH may suggest that recurrent BPPV has a relationship with migraine. Recurrent BPPV may potentially be a manifestation of migraine in the inner ear, which we term otologic migraine including cochlear, vestibular, or cochleovestibular symptoms.
Audio-vestibular Abnormalities in Patients With Vitiligo: A Prospective Case-control Study
Authors: Lasheen Reham Mamdouh , Elsheikh Mohamed Nasser , Fawzy Mohamed M. , Tomoum Mohamed Osama
Published: December 2020

Introduction:

Vitiligo is a disease that is characterized by a deficit of functional melanocytes all over the body including the inner ear.

Objectives:

To study the effect of the reduction of melanocytes on the audio-vestibular system in patients with vitiligo.

Subjects and Methodology:

Our study included 35 patients with vitiligo (study group) and 35 healthy volunteers (control group). Audiological and vestibular function assessments were performed in all the participants and the results were compared between the two groups. We assessed the auditory function utilizing pure-tone audiometry and the auditory brainstem response, while vestibular function was assessed by the Dizziness Handicap Inventory, the cervical vestibular-evoked myogenic potential (cVEMP), and videonystagmography.

Results:

Twelve patients with vitiligo showed impairment of the hearing especially in high frequencies in comparison with the control group. Auditory brainstem response wave III and I–III inter-peak latencies were significantly prolonged in the study group relative to the control subjects. On cVEMP testing, waves P13 and N23 were significantly delayed in the study group and the caloric test results showed that five vitiligo patients had unilateral weakness and three patients had bilateral weakness.

Conclusion:

Vitiligo is a systemic disease that can influence the audio-vestibular system. Screening tests for early detection of audio-vestibular changes in patients with vitiligo are important, as they are more susceptible to oxidative damage of ototoxic medications, noise exposure, and age-related hearing loss.
Clinical Presentation in Children With Coeliac Disease in Central Europe
Authors: Riznik Petra , De Leo Luigina , Dolinsek Jasmina , Gyimesi Judit , Klemenak Martina , Koletzko Berthold , Koletzko Sibylle , Korponay‐Szabó Ilma Rita , Krencnik Tomaz , Not Tarcisio , Palcevski Goran , Sblattero Daniele , Werkstetter Katharina Julia , Dolinsek Jernej
Published: December 2020

Objectives:

During the past decades, there has been a shift in the clinical presentation of coeliac disease (CD) to nonclassical, oligosymptomatic, and asymptomatic forms. We assessed clinical presentation of CD in children and adolescents in Central Europe.

Methods:

Paediatric gastroenterologists in 5 countries retrospectively reported data of their patients diagnosed with CD. Clinical presentation was analyzed and the differences among very young (<3 years) and older children and adolescents were studied.

Results:

Data from 653 children and adolescents (median age 7 years 2 months; 63.9% girls) from Croatia, Germany, Hungary, Italy, and Slovenia were available for the analysis. One fifth (N = 134) of all children were asymptomatic. In symptomatic children, the most common leading symptom was abdominal pain (33.3%), followed by growth retardation (13.7%) and diarrhoea (13.3%). The majority of symptomatic children (47.6%; N = 247) were polysymptomatic. Abdominal pain was the most common symptom in polysymptomatic (66.4%) as well as in monosymptomatic children (29.7%). Comparing clinical presentation of CD in very young children (younger than 3 years) with older children (3 years or older), we found that symptoms and signs of malabsorption were significantly more common in younger (P < 0.001), whereas abdominal pain and asymptomatic presentation were more common in older children and adolescents (both P < 0.001).

Conclusion:

In children with CD, abdominal pain has become the most common symptom. However, in younger children, symptoms of malabsorption are still seen frequently. This raises a question about the underlying mechanism of observed change in clinical presentation in favour of nonclassical presentation and asymptomatic disease at certain age.
Dengue and Plasmodium falciparum Coinfection With Secondary Hemophagocytic Lymphohistiocytosis in a 3-Year-old Boy: A Clinical Conundrum
Authors: Srivatsav Sathya , Mahalingam Soundarya , Ramineni Pardha , Manya Sharath
Published: December 2020

Hemophagocytic lymphohistiocytosis (HLH) is a multisystem disease wherein there is an exaggerated immune system activation following a trigger such as infection, malignancy, or autoimmune diseases. Here we report a case of a 3-year-old boy who presented to us with fever, was diagnosed with dengue fever, and treatment started for the same. Clinical response was poor to treatment and high-grade fever persisted. Subsequent evaluation showed Plasmodium falciparum malaria and treatment was initiated with antimalarial drugs. Further clinical deterioration with poor trend of laboratory values over the next few days prompted evaluation for HLH; workup was positive satisfying the HLH-2004 criteria and IV dexamethasone was started. The child gradually improved and was discharged with normal counts on follow-up over the next 3 months. This article emphasizes on the importance of high degree of suspicion, early workup, and initiation of treatment for HLH for a better outcome.