bluuebunny/crossref_metadata_2025 huggingface dataset:
Traders' dilemma: Developing countries' response to trade wars
Authors: Devarajan Shantayanan , Go Delfin S. , Lakatos Csilla , Robinson Sherman , Thierfelder Karen
Published: November 2020

As the United States engages in a trade war with its major trading partners, policymakers in developing countries face the ‘traders’ dilemma’: should they join the trade war, stay out or do something different, including continuing to pursue regional trading arrangements? Using a global, general equilibrium model, we paper simulate an increase in U.S. tariffs to non‐MFN rates and retaliation in kind by its major trading partners—the European Union, China, Mexico, Canada and Japan. We consider four possible responses by developing countries to this trade war: (a) join the trade war; (b) do nothing; (c) form regional trading arrangements with all regions outside the United States; and (d) unilaterally liberalise tariffs on imports from the United States. We find that joining the trade war is the worst option for developing countries (twice as bad as doing nothing); and forming RTAs with non‐U.S. regions and liberalising tariffs on U.S. imports (“turning the other cheek”) is the best. The reason is that a trade war between the United States and its major partners creates opportunities for developing countries to increase their exports to these markets. Liberalising tariffs increases developing countries’ price competitiveness, enabling them to further capitalise on these opportunities.
Comparison of crop and weed height, for potential differentiation of weed patches at harvest
Authors: Shahbazi Nooshin , Flower Ken C. , Callow J. Nikolaus , Mian Ajmal , Ashworth Michael B. , Beckie Hugh J.
Published: November 2020

Weeds and weed control are major production costs in global agriculture, with increasing challenges associated with herbicide‐based management because of concerns with chemical residue and herbicide resistance. Non‐chemical weed management may address these challenges but requires the ability to differentiate weeds from crops. Harvest is an ideal opportunity for the differentiation of weeds that grow taller than the crop, however, the ability to differentiate late‐season weeds from the crop is unknown. Weed mapping enables farmers to locate weed patches, evaluate the success of previous weed management strategies, and assist with planning for future herbicide applications. The aim of this study was to determine whether weed patches could be differentiated from the crop plants, based on height differences. Field surveys were carried out before crop harvest in 2018 and 2019, where a total of 86 and 105 weedy patches were manually assessed respectively. The results of this study demonstrated that across the 191 assessed weedy patches, in 97% of patches withAvena fatua(wild oat) plants, 86% withRaphanus raphanistrum(wild radish) plants and 92% withSonchus oleraceusL. (sow thistles) plants it was possible to distinguish the weeds taller than the 95% of the crop plants. Future work should be dedicated to the assessment of the ability of remote sensing methods such as Light Detection and Ranging to detect and map late‐season weed species based on the results from this study on crop and weed height differences.
Views of Trainee Science Teachers in Kuwait Regarding the NoS Dimensions and Their Conception of Creativity in Science Education
Authors: Alshammari Ahmad Shallal , Alsahou Hamed Jassim , Alshemmari Joza M
Published: November 2020

Science educators are often advised to pay attention to trainee teachers’ views on issues related to education, particularly the nature of science (NoS). Views on the NoS can be translated into pedagogical practices and then transferred to students; therefore, teachers should hold informed views about the NoS. This study sought to explore the views of trainee science teachers in Kuwait about the NoS and its aspects or dimensions. It also aimed to identify the possible connections among the NoS dimensions and teachers’ views on creativity in science. This multi-method study involved 152 trainee science teachers. The research instruments consisted of a questionnaire about teachers’ views of the nature of science (VNoS), a questionnaire about teachers’ views of creativity in science education, and semi-structured interviews. The findings revealed that trainee science teachers hold naïve and sometimes perplexing views of the NoS dimensions, and they are more likely to follow a traditional positivist worldview when they discuss the nature of scientific knowledge. Also, the findings revealed trainee teachers’ views of creativity in science education as well as significant correlations among six NoS dimensions and creativity. Detailed findings are discussed to draw conclusions and address possible suggestions for science educators and for the community of science education research.
Availability Analysis of a Steam Boiler in Textile Process Industries Using Failure and Repair Data: A Case Study
Authors: Patil Suyog S. , Bewoor Anand K. , Patil Rajkumar B.
Published: November 2020

The demand of steam in process industries is increasing rapidly, and this demand can be met by increasing the capacity utilization of steam boilers. Many of the process industries depend on industrial steam boilers as a vital component for their operation. The availability of the boiler can be improved by identifying critical mechanical subsystems/components concerning failure frequency, reliability, and maintainability and minimizing their likelihood of occurrences. The selection of appropriate technique for data collection and reliability analysis is essential. The time between failure (TBF) and time to repair (TTR) of all components and subsystems were collected to carry out reliability, availability, and maintainability (RAM) analysis. The best-fit distribution and distribution parameters were calculated using reliasoft software weibull++10 after performing trend testing. The preventive maintenance intervals of all components and subsystems and the availability of the system were evaluated. The analysis reveals that the combustion system, feed-water system, and blow-down system are the critical subsystems from a reliability perspective and are still the biggest reasons for the boiler downtime. The research study also showed that TTR was longer for the combustion system than the other subsystems, and thus, to enhance its availability, it is suggested that maintenance resources should be allocated at the appropriate moment to the combustion system. The study also shows the usage of RAM analysis in deciding the preventive maintenance intervals of components/subsystems of the boiler. It also provides a reference for the preparation of the maintenance plan for the boiler system.
Novel Approach for Optical Characterization of Thrust Collar Lubricated Area: Experimental and Numerical Results
Authors: Kerr Thomas , Delgado Adolfo
Published: November 2020

Thrust collars (TCs) are bearing elements used in geared machinery that transmit axial loads from one shaft to another. TCs are primarily used in integrally geared compressors (IGCs) but are also found in gearboxes and marine propulsion applications. TCs are hydrodynamic elements featuring a converging-diverging wedge to generate a pressure field that reacts axial loads. Accurate modeling requires knowledge of the film characteristics such as cavitation, turbulence, and air ingestion, all of which reduce load capacity. Current models in the literature do not include mass-conserving cavitation algorithms or turbulence flow. The following paper introduces a new test rig that optically characterizes the thin film region of a TC. The test rig geometries, speeds, and loads match those typically seen in IGC applications. The test rig utilizes a transparent acrylic window in conjunction with a high-speed camera (HSC) to obtain high-speed images of the oil film. Images are filtered and averaged to obtain areas of interest in the oil film. Cavitation and turbulence areas are measured for pinion speeds of 2.5, 5, and 7.5 krpm and axial loads of 0.5, 1, and 1.5 kN. Cavitation occurs in the diverging (upper) region of the TC and appears at pinion speeds over 5000 rpm but does not change in shape after that speed. The cavitation is independent of applied load. Turbulence at the inlet region (bottom) occurs at all speeds but increases to almost 35% of the total area at the highest speed. This paper also presents a finite element (FE) model that includes predictions for the static characteristics of the TC, specifically the cavitation area. The cavitation modeling uses an iterative Elord's method, which conserves mass. The model predicts a similar cavitation area for all speeds and loads. A computational fluid dynamics (CFD) study predicts a similar cavitation area and pressure field to the FE model. The CFD model predicts turbulence in the lower region that increases for increasing spin speed, which matches the experimental results. The CFD model tends to under-predict the turbulence area compared to the experiments. As IGCs move into new application areas to satisfy new needs, the increase in efficiency and capacity comes at a cost of more load and higher speed requirements on the TCs. This work will help original equipment manufacturers model TCs more accurately to ensure safe and efficient operation.
A New Methodology of Production Performance Prediction for Strong Edge-Water Reservoir
Authors: Zhang Angang , Fan Zifei , Zhao Lun , Wang Jincai , Song Heng
Published: November 2020

Material balance is a basic principle in reservoir engineering, which is still used as a quick and easy analytical tool for reservoir evaluation. In this article, a new methodology of production performance prediction for water-flooding reservoir was proposed based on the material balance principle, which considers the water saturation change caused by water injection and natural water influx, and its effect on transient gas–oil ratio. Among them, the cumulative water production was calculated based on Tong’s water-driver performance curve; the cumulative water influx was obtained by the Fetkovitch method; the transient gas–oil ratio can be acquired by Darcy’s law and Baker’s relative permeability model. Comparisons have been made between the new methodology and commercial reservoir simulator for two different reservoirs. The results show that there is good similarity between these two tools, which verifies the correctness of the new methodology.
Numerical Simulation of Impact Behavior of Ceramic Coatings Using Smoothed Particle Hydrodynamics Method
Authors: Zhang Jian , Lu Zhe , Sagar Sugrim , Choi Hyunhee , Jung Yeon-Gil , Park Heesung , Koo Dan Daehyun , Zhang Jing
Published: November 2020

In this work, the impact behavior of an alumina spherical particle on alumina coating is modeled using the smoothed particle hydrodynamics (SPH) method. The effects of impact angle (0 deg, 30 deg, and 60 deg) and velocity (100 m/s, 200 m/s, and 300 m/s) on the morphology changes of the impact pit and impacting particle, and their associated stress and energy are investigated. The results show that the combination of impact angle of 0 deg and velocity of 300 m/s produces the highest penetration depth and largest stress and deformation in the coating layer, while the combination of 100 m/s and 60 deg causes the minimum damage to the coating layer. This is because the penetration depth is determined by the vertical velocity component difference between the impacting particle and the coating layer, but irrelevant to the horizontal component. The total energy of the coating layer increases with the time, while the internal energy increases with the time after some peak values, which is due to energy transmission from the spherical particle to the coating layer and the stress shock waves. The energy transmission from impacting particle to coating layer increases with the increasing particle velocity and decreases with the increasing inclined angle. The simulated impact pit morphology is qualitatively similar to the experimental observation. This work demonstrates that the SPH method is useful to analyze the impact behavior of ceramic coatings.
Parameter Identification Based on Nonlinear Observer for Mechanical Systems
Authors: Ordaz Patricio , Ramírez Miguel , Rodríguez Liliam , Cuvas Carlos , Romero Hugo , Sandre Omar
Published: November 2020

This paper deals with the parameter identification problem for nonlinear mechanical systems based on state estimation. Here, the concept of Sliding Mode Observer for finite time state estimation and the Least-Square Method for parameter identification have been combined; thus, guaranteeing that the estimated state converges to the real one in a finite time. The asymptotic parameter identification is performed by applying the Least-Square approach, minimizing the so-called joint uncertainty; in this process, a specific persistent excitation condition is introduced to guarantee the effectiveness of the proposed identification algorithm. With the proposed approach and some considerations, the algorithm is capable of estimating friction coefficients and inertia moments, within a narrow time-window. Finally, the performance of the identification algorithm designed in this paper is tested on a real-time underactuated system, specifically the double pendulum on a cart platform. Furthermore, a successful benchmarking between the algorithm herein and the traditional least-square method is reported.
Truncation Error Based Mesh Optimization
Authors: Jackson Charles W. , Roy Christopher J. , Schrock Christopher R.
Published: November 2020

Truncation error is used to drive mesh adaptation in order to reduce the discretization error in solutions to a variety of 1D and 2D flow problems. The adaptation is performed using r-adaptation to move the mesh nodes in the domain in an attempt to reduce the truncation error since it is the local source of discretization error. Here, we present a new set of r-adaptation methods called mesh optimization along with three different ways of performing this type of adaptation. Each of these techniques uses a finite difference gradient-based local optimization technique with different sets of design variables to create a mesh that minimizes a functional based on truncation error. These new truncation error based mesh optimization techniques are compared to a more common truncation error based mesh equidistribution technique. Some observations on the performance and behavior of the different adaptation methods and best practices for their use are presented. All of the optimization methods are shown to reduce the truncation error one or two orders of magnitude and the discretization error by roughly one order of magnitude for the 1D problems tested. In two dimensions, the optimization-based adaptation methods are able to reduce the discretization error by up to a factor of seven. Mesh equidistribution achieved similar levels of improvement for much less cost compared to the mesh optimization techniques.
Guillain-Barré syndrome and COVID-19: an observational multicentre study from two Italian hotspot regions
Authors: Filosto Massimiliano , Cotti Piccinelli Stefano , Gazzina Stefano , Foresti Camillo , Frigeni Barbara , Servalli Maria Cristina , Sessa Maria , Cosentino Giuseppe , Marchioni Enrico , Ravaglia Sabrina , Briani Chiara , Castellani Francesca , Zara Gabriella , Bianchi Francesca , Del Carro Ubaldo , Fazio Raffaella , Filippi Massimo , Magni Eugenio , Natalini Giuseppe , Palmerini Francesco , Perotti Anna Maria , Bellomo Andrea , Osio Maurizio , Scopelliti Giuseppe , Carpo Marinella , Rasera Andrea , Squintani Giovanna , Doneddu Pietro Emiliano , Bertasi Valeria , Cotelli Maria Sofia , Bertolasi Laura , Fabrizi Gian Maria , Ferrari Sergio , Ranieri Federico , Caprioli Francesca , Grappa Elena , Broglio Laura , De Maria Giovanni , Leggio Ugo , Poli Loris , Rasulo Frank , Latronico Nicola , Nobile-Orazio Eduardo , Padovani Alessandro , Uncini Antonino
Published: November 2020

Objective

Single cases and small series of Guillain-Barré syndrome (GBS) have been reported during the SARS-CoV-2 outbreak worldwide. We evaluated incidence and clinical features of GBS in a cohort of patients from two regions of northern Italy with the highest number of patients with COVID-19.

Methods

GBS cases diagnosed in 12 referral hospitals from Lombardy and Veneto in March and April 2020 were retrospectively collected. As a control population, GBS diagnosed in March and April 2019 in the same hospitals were considered.

Results

Incidence of GBS in March and April 2020 was 0.202/100 000/month (estimated rate 2.43/100 000/year) vs 0.077/100 000/month (estimated rate 0.93/100 000/year) in the same months of 2019 with a 2.6-fold increase. Estimated incidence of GBS in COVID-19-positive patients was 47.9/100 000 and in the COVID-19-positive hospitalised patients was 236/100 000. COVID-19-positive patients with GBS, when compared with COVID-19-negative subjects, showed lower MRC sum score (26.3±18.3 vs 41.4±14.8, p=0.006), higher frequency of demyelinating subtype (76.6% vs 35.3%, p=0.011), more frequent low blood pressure (50% vs 11.8%, p=0.017) and higher rate of admission to intensive care unit (66.6% vs 17.6%, p=0.002).

Conclusions

This study shows an increased incidence of GBS during the COVID-19 outbreak in northern Italy, supporting a pathogenic link. COVID-19-associated GBS is predominantly demyelinating and seems to be more severe than non-COVID-19 GBS, although it is likely that in some patients the systemic impairment due to COVID-19 might have contributed to the severity of the whole clinical picture.
Large contribution of pulsed subsidies to a predatory fish inhabiting large stream channels
Authors: Itakura Hikaru , Miyake Yoichi , Kitagawa Takashi , Sato Takuya , Kimura Shingo
Published: November 2020

Resource subsidies exert critical influences on recipient habitats with relatively higher perimeter-to-area ratios, such as headwaters in watersheds. However, little is known about how those subsidies contribute to the energy sources in recipient habitats where the perimeter-to-area ratio is low, such as large stream channels. Here, we show that the diet of small Japanese eels (Anguilla japonica) <500 mm in total length inhabiting natural shoreline areas in large stream channels consists largely of terrestrial earthworms (Metaphire spp.). Stable isotopic analyses showed that the earthworms were the prey animal that contributed most to the eels’ diet (45%–47%). Earthworms constituted the largest portion of the eels’ stomach contents (7%–93%). Eels ingested earthworms within 2 days after rainfall during spring, summer, and autumn, and their consumption increased as the precipitation increased. These findings indicate that the pulsed earthworm subsidy that is driven by rainfall could temporarily bias the eels’ diet toward this allochthonous resource, which may explain the large contribution of the subsidy for consumers inhabiting large stream channels. Furthermore, diverse earthworm species could drive multiple pulsed subsidies across seasons and provide the predators with a prolonged subsidy, enhancing the long-term contribution of the subsidy to the predators’ diet.
Variance estimation for mean growth from successive double sampling for stratification
Authors: Fischer Christoph , Saborowski Joachim
Published: November 2020

Double sampling for stratification (2SS) is a sampling design that is widely used for forest inventories. We present the mathematical derivation of two appropriate variance estimators for mean growth from repeated 2SS with updated stratification on each measurement occasion. Both estimators account for substratification based on the transition of sampling units among the strata due to the updated allocation. For the first estimator, sizes of the substrata were estimated from the second-phase sample (sample plots), whereas the respective sizes in the second variance estimator relied on the larger first-phase sample. The estimators were empirically compared with a modified version of Cochran’s well-known 2SS variance estimator that ignores substratification. This was done by performing bootstrap resampling on data from two German forest districts. The major findings were as follows: (i) accounting for substratification, as implemented in both new estimators, has substantial impact in terms of significantly smaller variance estimates and bias compared with the estimator without substratification, and (ii) the second estimator with substrata sizes being estimated from the first-phase sample shows a smaller bias than the first estimator.
On the invariant analysis, symmetry reduction with group-invariant solution and the conservation laws for (2 + 1)-dimensional modified Heisenberg ferromagnetic system
Authors: Vinita  , Ray S. Saha
Published: November 2020

In this paper, a [Formula: see text]-dimensional modified Heisenberg ferromagnetic system, which appears in the biological pattern formation and in the motion of magnetization vector of the isotropic ferromagnet, is being investigated with the aim of exploring its similarity solutions. With the aid of Lie symmetry analysis, this system of partial differential equations has been reduced to a new system of ordinary differential equations, which brings an analytical solution of the main system. Infinitesimal generators, commutator table, and the group-invariant solutions have been carried out by using Lie symmetry approach. Moreover, conservation laws of the above mentioned system have been obtained by utilizing the new conservation theorem proposed by Ibragimov. By applying this analysis, the obtained results might be helpful to understand the physical structure of this model and show the authenticity and effectiveness of the proposed method.
Metaheuristic Optimization of Insulin Infusion Protocols Using Historical Data with Validation Using a Patient Simulator
Authors: Wang Hongyu , Chepulis Lynne , Paul Ryan G. , Mayo Michael
Published: November 2020

Metaheuristic search algorithms are used to develop new protocols for optimal intravenous insulin infusion rate recommendations in scenarios involving hospital in-patients with Type 1 Diabetes. Two metaheuristic search algorithms are used, namely, Particle Swarm Optimization and Covariance Matrix Adaption Evolution Strategy. The Glucose Regulation for Intensive Care Patients (GRIP) serves as the starting point of the optimization process. We base our experiments on a methodology in the literature to evaluate the favorability of insulin protocols, with a dataset of blood glucose level/insulin infusion rate time series records from 16 patients obtained from the Waikato District Health Board. New and significantly better insulin infusion strategies than GRIP are discovered from the data through metaheuristic search. The newly discovered strategies are further validated and show good performance against various competitive benchmarks using a virtual patient simulator.
Influence Maximization on Undirected Graphs
Authors: Schoenebeck Grant , Tao Biaoshuai
Published: November 2020

We study the influence maximization problem in undirected networks, specifically focusing on the independent cascade and linear threshold models. We prove APX-hardness (NP-hardness of approximation within factor (1-τ) for some constant τ > 0) for both models, which improves the previous NP-hardness lower bound for the linear threshold model. No previous hardness result was known for the independent cascade model.

As part of the hardness proof, we show some natural properties of these cascades on undirected graphs. For example, we show that the expected number of infections of a seed set
S
is upper bounded by the size of the edge cut of
S
in the linear threshold model and a special case of the independent cascade model, the weighted independent cascade model.

Motivated by our upper bounds, we present a suite of highly scalable local greedy heuristics for the influence maximization problem on both the linear threshold model and the weighted independent cascade model on undirected graphs that, in practice, find seed sets that on average obtain 97.52% of the performance of the much slower greedy algorithm for the linear threshold model and 97.39% of the performance of the greedy algorithm for the weighted independent cascade model. Our heuristics also outperform other popular local heuristics, such as the degree discount heuristic by Chen et al. [7].
Dynamic Neutron Imaging and Modeling of Cationic Impurities in Polymer Electrolyte Water Electrolyzer
Authors: Zlobinski Mateusz , Babic Ugljesa , Fikry Meriem , Gubler Lorenz , Schmidt Thomas J. , Boillat Pierre
Published: November 2020

The high operation and capital costs of polymer electrolyte water electrolyzers (PEWE) are the major obstacles that have to be tackled for hydrogen to penetrate the market as a solution for renewable energy storage. Commercial stacks often suffer from cationic contamination of catalyst-coated membranes (CCMs) that comes from impure feed water and corrosion of system components, which can result in increasing operation costs and lowered lifetime. This study describes the behavior of the contaminants in the CCMs and their impact on performance under various operating conditions using Gd3+ as model contaminant imaged with neutron with a combination of high effective temporal (2 s) and spatial (30 μm) resolutions. The presence of electric field directly affects the position of cations in the CCM leading to their accumulation near the cathode catalyst layer. The cationic impurities trigger multiple loss mechanisms, as the ohmic resistance increase does not scale linearly with the amount of occupied exchange groups in the membrane (10% resistance increase caused by 2.5% exchange groups occupation). A model has been developed that predicts the movement of the ions in the CCM under intermittently operating PEWE and was used as a basis to explain the hysteresis observed in the polarization curve of contaminated PEWEs.
Effects of PEMFC Operational History under Dry/Wet Conditions on Additional Voltage Losses due to Ionomer Migration
Authors: Du Fengmin , Dao Tuan Anh , Peitl Pia Valentina Josephine , Bauer Andreas , Preuss Kathrin , Bonastre Alex Martinez , Sharman Jonathan , Spikes Geoffrey , Perchthaler Markus , Schmidt Thomas J. , Orfanidi Alin
Published: November 2020

Over its lifetime in a fuel cell electric vehicle, a polymer electrolyte membrane fuel cell inevitably suffers from certain duration of dry operational conditions, where significant performance losses of the fuel cell take place. In this study, we investigate the activity changes of the fuel cell after a prolonged degradation protocol under dry operational condition, followed by various recovery procedures under wet conditions. The utilization of diluted air on the cathode side is found to be advantageous for the recovery due to the superior heat and water management. This more efficient recovery protocol allows the deconvolution of reversible and irreversible voltages losses after dry operations. A subsequent mechanistic study reveals an irreversible decrease of the effective ionomer coverage on the catalyst particles, while the proton conductivity of the catalyst layer drops. These observations point towards ionomer structural changes caused by the dry conditions. This is confirmed by post-mortem analysis via scanning electron microscope, showing clearly that ionomer redistributes and migrates, an additional mechanism which leads to the performance losses. Overall, the degradation mechanisms seem to be mitigated by higher ionomer content in the catalyst layer, while the investigated surface modification of carbon support shows minor sensitivities.
Editors’ Choice—Review—Creating Electrocatalytic Heterojunctions for Efficient Photoelectrochemical CO2 Reduction to Chemical Fuels
Authors: Strange Lyndi E. , Yadav Jeetika , Li Xiao , Pan Shanlin
Published: November 2020

Artificial photosynthesis can potentially address the global energy challenges and environmental issues caused by fossil fuels. Photoelectrochemical heterojunction structures of new photonic structures have been developed for efficient sunlight absorption, charge generation and separation and transport, and selective reduction of CO2 and water splitting. In this review, an overview of several recently developed heterojunction model systems comprised of low-cost photonic materials such as transition metal dichalcogenides (TMDs), perovskite semiconductor nanocrystals, and plasmonic nanostructures is presented to rationalize the potential benefits of utilizing heterojunction structures for efficient and selective CO2 reduction with renewable energy resources. Recent advances in electroanalytical methods for CO2 reduction such as scanning electrochemical microscopy (SECM) are reviewed. These techniques can potentially resolve local CO2 reduction kinetics and their spatial heterogeneities of a heterojunction photoelectrochemical structure.
Communication—Luminescence Properties of a Novel l Rb2KGaF6:Mn4+ Red-Emitting Phosphor for Solid-State Lighting
Authors: Shi Dongxin , Xie Xiaoling , Pu Haiqi , Zhang Xi , Zhou Qiang , Wang Zhengliang , Ye Yanqing , Chen Minghong
Published: November 2020

A novel red-emitting Rb2KGaF6:Mn4+ phosphor with octahedral particulate morphology was presented. The XRD Rietveld refinement results indicate that the phosphor crystallized into the cubic phase of Fm

3

¯

m space group with double perovskite structure. The photo-luminescence spectrum exhibits intense red emission lines with zero-phonon line (ZPL) and v
6 peak locating at 620 and 628 nm respectively. The optical parameters of low color temperature (T
c = 3824 K) and high color rendering index (R
a = 90.2 ) from white LED imply its potential application in solid-state lighting.
The effectiveness of formative assessment in pathophysiology education from students’ perspective: a questionnaire study
Authors: Cong Xin , Zhang Yan , Xu Hai , Liu Li-Mei , Zheng Ming , Xiang Ruo-Lan , Wang Jin-Yu , Jia Shi , Cai Jing-Yi , Liu Cheng , Wu Li-Ling
Published: November 2020

Current interdisciplinary medical training calls for reforms and innovations in the assessment of pathophysiology education. Formative assessment is used to monitor student learning to provide ongoing feedback that can improve both learning and teaching. Beginning in 2016, we implemented a formative assessment composed of case-based multiple-choice questions (MCQs) for all students in all majors. In 2017, case study questions began to be employed in the formative assessment, and student-set, case-based questions were further introduced. Aiming to gather the students’ suggestions and feedback on the mixed-method assessment, we conducted a survey on aspects such as the effectiveness of the assessment, assessment content and completion, opinions on student-set questions, and the impact on pathophysiology learning for students from 2017 to 2019. In addition, we compared students’ semesterly final scores with those of previous students and evaluated the relationship between formative and summative assessment scores. The results for 1,277 students clearly showed that the reformed formative assessment system was well received by the students. The students thought that the formative assessment not only allowed for the provision of real-time feedback on the effectiveness of teaching and learning but also nurtured self-motivation, the development of analytical and problem-solving skills, and collaborative efforts. Both the semesterly final scores and the proportions of students scoring in higher score ranges increased after the implementation of the formative assessment, and the summative assessment scores were positively related to the formative assessment scores. Consequently, the reformed formative assessment system significantly improved the quality of pathophysiology education.
Comparative Analysis of Different Isolated Oleaginous Mucoromycota Fungi for Their γ‐Linolenic Acid and Carotenoid Production
Authors: Mohamed Hassan , El-Shanawany Abdel-Rahim , Shah Aabid Manzoor , Nazir Yusuf , Naz Tahira , Ullah Samee , Mustafa Kiren , Song Yuanda
Published: November 2020

γ‐Linolenic acid (GLA) and carotenoids have attracted much interest due to their nutraceutical and pharmaceutical importance. Mucoromycota, typical oleaginous filamentous fungi, are known for their production of valuable essential fatty acids and carotenoids. In the present study, 81 fungal strains were isolated from different Egyptian localities, out of which 11 Mucoromycota were selected for further GLA and carotenoid investigation. Comparative analysis of total lipids by GC of selected isolates showed that GLA content was the highest in Rhizomucor pusillus AUMC 11616.A, Mucor circinelloides AUMC 6696.A, and M. hiemalis AUMC 6031 that represented 0.213, 0.211, and 0.20% of CDW, respectively. Carotenoid analysis of selected isolates by spectrophotometer demonstrated that the highest yield of total carotenoids (640 μg/g) was exhibited by M. hiemalis AUMC 6031 and M. hiemalis AUMC 6695, and these isolates were found to have a similar carotenoid profile with, β‐carotene (65%), zeaxanthin (34%), astaxanthin, and canthaxanthin (5%) of total carotenoids. The total fatty acids of all tested isolates showed moderate antimicrobial activity against Staphylococcus aureus and Salmonella Typhi, and Penicillium chrysogenum. To the best of our knowledge, this is the first report on the highest yield of total lipid accumulation (51.74% CDW) by a new oleaginous fungal isolate R. pusillus AUMC 11616.A. A new scope for a further study on this strain will be established to optimize and improve its total lipids with high GLA production. So, R. pusillus AUMC 11616.A might be a potential candidate for industrial application.
Investigating the Response Amplitude Operator of a Heaving Pontoon under the Influence of a Submerged Trapezoidal Breakwater
Authors: Ghadimi Parviz , Pourmostafa Mehdi , Najafi Saeed
Published: November 2020

Although breakwaters are of great importance to damp the wave energy and protect floating vessels/facilities, they are not fully successful in reducing the waves’ height. Therefore, special attention should be paid to accurately investigate the performance of breakwaters. In this paper, the efficiency of a submerged trapezoidal breakwater in the vicinity of a floating pontoon is numerically investigated. First, different simulations are conducted to calibrate the numerical model to achieve an optimum mesh size. Next, a test case is presented for simulation of regular waves passing over a submerged breakwater. Subsequently, the heave response amplitude operator (RAO) of a rectangular pontoon facing an incoming regular wave is studied. A comparison of the obtained results in both test cases with experimental data shows good compliance. Ultimately, the heave motion of a rectangular pontoon behind four different submerged trapezoidal breakwaters facing a regular wave is investigated and different parametric studies are conducted to assess the geometrical effect of the breakwaters. This is the main novelty of the present work which studies the effect of a breakwater on the response amplitude operator (RAO) of a floating structure. In fact, a new version of RAO is presented which includes both incident and transferred wave (which pass over the breakwater) affecting the floating body. Based on the acquired results, the modified RAO of the heaving pontoon shows that breakwater has no effect on the responding frequency, but it does reduce the amplitude of the exciting wave up to 30%.
Location-Constrained Virtual Machine Placement (LCVP) Algorithm
Authors: Liu Zhenpeng , Lu Jiahuan , Su Nan , Zhang Bin , Li Xiaofei
Published: November 2020

Virtual machine (VM) placement is the current day research topic in cloud computing area. In order to solve the problem of imposing location constraints on VMs to meet their requirements in the process of VM placement, the location-constrained VM placement (LCVP) algorithm is proposed in this paper. In LCVP, each VM can only be placed onto one of the specified candidate physical machines (PMs) with enough computing resources and there must be sufficient bandwidth between the selected PMs to meet the communication requirement of the corresponding VMs. Simulation results show that LCVP is feasible and outperforms other benchmark algorithms in terms of computation time and blocking probability.
Calculation of Hinge Moments for a Folding Wing Aircraft Based on High-Order Panel Method
Authors: Xu Hao , Huang Qin , Han Jinglong , Yun Haiwei
Published: November 2020

Calculating hinge moments during the morphing process is a critical aspect in the folding wing design. The deficiencies of the traditional flat-plate aerodynamic model in the calculation are expounded in this work, and a flight simulation platform based on a high-order panel method is established. On the basis of the platform, a typical flight-folding process of the aircraft is simulated, and the results of different aerodynamic models are compared. Results show that airfoil thickness has a great influence on the aerodynamic loading distribution of wing surfaces and thus affects the hinge moments during the folding process. The flat-plate method, which ignores the influence of the airfoil thickness, shows a great simulation error in hinge moment, whereas the high-order panel method can effectively describe the thickness effect and obtain reliable simulation results.
Rigosertib Induces Mitotic Arrest and Apoptosis in RAS-Mutated Rhabdomyosarcoma and Neuroblastoma
Authors: Kowalczyk Joshua T. , Wan Xiaolin , Hernandez Edjay R. , Luo Ruibai , Lyons Gaelyn C. , Wilson Kelli M. , Gallardo Devorah C. , Isanogle Kristine A. , Robinson Christina M. , Mendoza Arnulfo , Heske Christine M. , Chen Jinqui-Qiu , Luo Xiaoling , Kelly Alexander E. , Difilippantinio Simone , Robey Robert W. , Thomas Craig J. , Sackett Dan L. , Morrison Deborah K. , Randazzo Paul A. , Jenkins Lisa M. Miller , Yohe Marielle E.
Published: November 2020

Relapsed pediatric rhabdomyosarcomas (RMS) and neuroblastomas (NBs) have a poor prognosis despite multimodality therapy. In addition, the current standard of care for these cancers includes vinca alkaloids that have severe toxicity profiles, further underscoring the need for novel therapies for these malignancies. Here, we show that the small-molecule rigosertib inhibits the growth of RMS and NB cell lines by arresting cells in mitosis, which leads to cell death. Our data indicate that rigosertib, like the vinca alkaloids, exerts its effects mainly by interfering with mitotic spindle assembly. Although rigosertib has the ability to inhibit oncogenic RAS signaling, we provide evidence that rigosertib does not induce cell death through inhibition of the RAS pathway in RAS-mutated RMS and NB cells. However, the combination of rigosertib and the MEK inhibitor trametinib, which has efficacy in RAS-mutated tumors, synergistically inhibits the growth of an RMS cell line, suggesting a new avenue for combination therapy. Importantly, rigosertib treatment delays tumor growth and prolongs survival in a xenograft model of RMS. In conclusion, rigosertib, through its impact on the mitotic spindle, represents a potential therapeutic for RMS.
The Expression of ZnT3 and GFAP Is Potentiated in the Hippocampus of Drug-Resistant Epileptic Rats Induced by Amygdala Kindling
Authors: Huang Yuanxin , Wang Lin , Ren Siying , Wu Guofeng , Wu Jing
Published: November 2020

Objective: The first-line treatment for epilepsy, a chronic neurological disorder characterized by spontaneous seizures, includes the application of anticonvulsant drug therapy. Only one-third of patients are incapable of complete controlling of their seizures after the administration of ≥2 pharmaceuticals. Here, we aimed to observe the ultrastructure changes and the expression of ZnT3 and GFAP in the hippocampus of drug-resistant epileptic rats. Methods: A total of 50 healthy adult male SD rats were used to generate the model ofepilepsy by amygdala kindling. After the rats were successfully kindled, pharmacoresistant epileptic (PRE) rats were selected according to their response to phenobarbital and phenytoin. The ultrastructure as well as the expression of zinc transporter 3 (ZnT3, a member of a growing family of mammalian zinc transporters) and glial fibrillary acidic protein (GFAP) were compared among PRE, pharmacosensitive epileptic (PRE), and normal (NRC) rats. Results: The PRE rats displayed severe synapses, neuronal degeneration, and necrosis. Moreover, the expression of ZnT3 and GFAP was significantly increased in both PRE and PSE rats; compared with NRC rats, the promotion of this expression was more pronounced in the PRE rats. Conclusions: Taken together, obvious synapses, neuronal degeneration, necrosis, mossy fiber sprouting, and astrogliosis were found in the drug-resistant epileptic rat model induced by amygdala kindling.
Expositionsübungen und Verhaltensexperimente: Varianten des erfahrungsbasierten Lernens in der Verhaltenstherapie
Authors: Hoyer Jürgen , Niermann Hannah C.M.
Published: November 2020

Expositionsübungen (Reizkonfrontationen) stellen die wichtigste Interventionskomponente bei Angststörungen dar; Verhaltensexperimente die wichtigste beobachtungsbezogene Disputationsmethode. Beides sind Beispiele erfahrungsorientierten Lernens in der Verhaltenstherapie. In der vorliegenden Übersichtsarbeit werden diese Vorgehensweisen definiert, in ihren Durchführungsvarianten dargestellt und hinsichtlich ihrer logischen Begründung sowie ihrer hypothetischen Wirkmechanismen verglichen. Dabei wird deutlich, dass beide Ansätze gemäß dem Prinzip der Erwartungs- bzw. Befürchtungswiderlegung (expectancy violation) erwartungs- bzw. einstellungskonträre Erfahrungen ermöglichen sollen. Der Schwerpunkt bei den Expositionsübungen liegt auf der Veränderung des emotionalen Erlebens und automatisierter Vermeidungsreaktionen in bestimmten Zielsituationen, bei den Verhaltensexperimenten liegt er auf der Veränderung von Einstellungen und Erwartungen. Ferner wird bei den Expositionsübungen der Erwerb emotionaler Kompetenzen (Furchttoleranz) angestrebt, was bei Verhaltensexperimenten zumindest nicht primär intendiert ist. Zwar zielt die Fallkonzeption bei Expositionen mehr auf die Veränderung problematischer Handlungen/Vermeidungsreaktionen und bei Verhaltensexperimenten mehr auf die Veränderung problematischer Kognitionen, beide Interventionsvarianten konvergieren aber grundsätzlich hinsichtlich des übenden Ansatzes, bei dem durch häufige Wiederholung im Alltag positive Kontrasterfahrungen stabil im Gedächtnis verankert werden sollen.
Lecturers’ language problems in writing english papers for international publications
Authors: Hartono Hartono , Arjanggi Ruseno , Nugroho Kurniawan Yudhi , Maerani Ira Alia
Published: November 2020

Indonesian lecturers are now encouraged to publish papers in international journals so that they can better disseminate research findings and innovations globally.  However, many of them have the problems with English language mastery. This study was aimed at identifying and analyzing language problems of the Indonesian university lecturers in writing English academic papers for international publications. The subjects of the study were 66 randomly selected lecturers of various disciplines other than English Education and English Literature. The data were collected by questionnaire and English writing tasks on phrases, sentences, and paragraphs which were then analyzed descriptively. The results show that language errors and mistakes in grammar, syntax, vocabulary, spelling and word forms were all found in the subjects’ writings.  In writing academic papers for international publications, university lecturers faced language problems as constructing phrases and sentences, choosing and using appropriate vocabulary and terms relevant to their topic of study as well as translating their Indonesian sentences into English.
Self-efficacy and work readiness among vocational high school students
Authors: Tentama Fatwa , Merdiaty Netty , Subardjo Subardjo
Published: November 2020

This study aims to empirically examine the effect of self-efficacy on students' work readiness. The subjects in this study were students of class XII of State Vocational High School 1 Seyegan totalling 174 students which were obtained by cluster random sampling. The research method used is a quantitative method with work readiness scale and self-efficacy scale. Analysis of the data used in this study is a simple regression analysis technique. The results of data analysis showed a very significant effect of self-efficacy on work readiness, with the F test, namely: 22.768, with a significance level (p) of 0.000 (p 0.01). The contribution of the effect of self-efficacy of 11.2% on work readiness and the remaining 88.8% was influenced by other factors outside the variables studied. It means that students’ self-efficacy can predict their work readiness.
Student motivation in choosing learning at UIN Raden Intan Lampung
Authors: Leni Nurhasanah
Published: November 2020

Entering the 4.0 industrial revolution, the number of Indonesians who consider it important to education is increasing. This is evidenced by the increasing number of students and the increasing number of university choices. However, what actually motivated the students to choose the college? This study aims to determine the factors that influence the decisions of students (motivation) who choose to study at Raden Intan Lampung State Islamic University. This study uses an anthropological approach with ethnography method. The subject of the study was students of UIN Raden Intan Lampung with a sample of class A UIN students (Class Chair and Secretary) of 2015 from 5 faculties. The results showed that there were 6 factors that influenced students to choose to study at UIN Raden Intan Lampung, with the most dominant factor is respondents’ self motivation who think that UIN Raden Intan Lampung is an Islamic based institution, so that students would get world knowledge (academic) and the Hereafter (Islamic).
The effect of virtual reality laboratory on conceptual understanding in electrolytes and non-electrolytes
Authors: Amiati Afsari
Published: November 2020

This study aims to determine the effect of the use of learning media Virtual Reality Laboratory (VR-Lab) on the conceptual understanding of Senior high school students on the concept of electrolytes and non-electrolytes. The learning media used were developed using models adapted from the ADDIE model, while the type of research as a whole uses this type of research, namely Quasy experiment with posttest only design. The instrument used in this study was a multiple choice question of 40 items. This research was conducted using 84 students consisting of the control class, experiment I, and experiment II. The analysis technique used one-way ANOVA. The results obtained in this study were that between the control class and experiment I class there were no significant differences with a mean of 44.91 and 45.67. Whereas for the experimental II class had a significant difference with the other two classes with an average of 68.66.
Multicultural strip comic as a learning media to improve the caring character in primary school
Authors: Aulia Nisa , Wuryandani Wuri
Published: November 2020

This research of development aims to produce eligible media and test the effectiveness of multicultural strip comic to improve the caring character of primary school students. It referred to the 10 steps of Borg Gall.  This research was held on fourth-grade students at five primary schools in Gondokusuman District, Yogyakarta. It consisted of 9 students at the preliminary field testing, 36 students at the main field testing and 62 students at the operational field testing which were divided into two groups, namely experiment class and control class. The technique of data collection involved interviews, observation, scales, and questionnaires. The expert rating scale and the response questionnaire were used to determine the feasibility of the media. The effectiveness of the media was analyzed by the N-Gain score and t-test with a significance level of 0.05. The result showed that multicultural strip comic media is feasible and effective to improve caring character.  This is seen from the N-Gain score and the result of the t-test which obtained a significance value of 0.000 (p ≤ 0.05) which means it can improve the caring character of primary school students.