bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydraulic requirements of freshwater mussels (Unionidae) and a conceptual framework for how they respond to high flows
Authors: Randklev Charles R. , Hart Michael A. , Khan Jennifer M. , Tsakiris Eric T. , Robertson Clinton R.
Published: December 2019

Spatiotemporal variability in flow determines the physical structures of habitat. During low flows, aquatic organisms can be exposed to reduced dissolved oxygen concentrations, increased water temperature, and desiccation, whereas at high flows, increased velocity and hydraulic forces on the streambed can be equally detrimental. These constraints create a mosaic of habitat that influences the distribution and abundance of aquatic biota. This mosaic can change due to stochastic events or those mediated by humans. Understanding how low and high flow conditions affect aquatic organisms is critical not only for advancing ecological knowledge but also for protecting imperiled aquatic species such as unionid mussels. The overall goal of this project was to examine how substrate and hydrologic conditions affect mussel habitat and to then use the resulting information combined with life‐history traits and shell morphology (i.e., sculpturing) to better understand how flow shapes mussel assemblage structure. Using quantile regression, we found that low values of relative shear stress (RSS), a measure of substrate stability, were associated with high mussel species richness and density. Change point analysis using threshold indicator taxa analysis (TITAN) indicated species‐specific preferences for varying levels of bed stability. These preferences were best explained by life‐history strategy and shell morphology based on the results of a principal component analysis. Using these results, we then present a conceptual model from which to derive expectations concerning taxonomic composition, life‐history strategy, and shell sculpture type based on the degree of substrate mobility using RSS and variability in RSS.
Soil erosion rates assessed by RUSLE and PESERA for a Chinese Loess Plateau catchment under land‐cover changes
Authors: Li Pengfei , Zang Yuzhe , Ma Doudou , Yao Wanqiang , Holden Joseph , Irvine Brian , Zhao Guangju
Published: December 2019

On the Chinese Loess Plateau, soil erosion models are often employed to predict erosion rates and responses to land‐use/‐cover changes (LUCCs). Previous Loess Plateau studies employed individual models with specific emphases but model comparisons have not been undertaken so the relative performance of different models is not known. In this study we employed two extensively applied models (RUSLE and PESERA) to investigate the impact of LUCCs during 1990–2000 and 2000–2011 on soil erosion rates for a typical Loess Plateau catchment (i.e. Huangfuchuan), and compared their modelling results. Land‐cover patterns for 1990, 2000 and 2011 were derived from Landsat images. The catchment was dominated by grassland (over 70%) and experienced considerable LUCCs: vegetation coverage increased from 38.3% in 1990 to 48.7% in 2011. Modelling results suggested that mean soil erosion rates of the catchment increased under the 1990–2000 LUCC and decreased under the 2000–2011 LUCC. Sandy land and scrubland were found to suffer from most severe soil erosion and thus should be the focus of future conservation work. Mean soil erosion rates on steep slopes (i.e. > 25°) were predicted to increase under the 2000–2011 LUCC, implying that further work is still needed to study soil erosion processes and their conservation on steep slopes. Model comparisons showed that RUSLE predictions were higher than PESERA predictions for most areas (particularly for steep slopes), and the former were generally closer than the latter to check‐dam sediment yield measurements. RUSLE and PESERA results were not linearly correlated, possibly due to differences in their underlying principles and their sensitivity to crucial parameters – RUSLE is more sensitive to slope gradients while PESERA is more sensitive to vegetation coverage. PESERA needs improvement to better account for steep slope erosion processes on the Loess Plateau, while RUSLE needs improvement in the description of vegetation effects. © 2019 John Wiley & Sons, Ltd.
From Half‐Cells to Membrane‐Electrode Assemblies: a Comparison of Oxygen Reduction Reaction Catalyst Performance Characteristics
Authors: Kim O.‐H. , Ahn C.‐Y. , Kang S. Y. , Kim S. , Choi H. J. , Cho Y.‐H. , Sung Y.‐E.
Published: December 2019

Several studies relying on the improvements to the important oxygen reduction reaction (ORR) activity for increasing the performance of fuel cells have been reported. However, the application of catalyst conditions used for realizing the excellent activity in a half‐cell to a single‐cell does not guarantee the translation of the excellent performance. Therefore, we investigated the performance characteristics of various types of commercially available catalysts, including alloy catalysts, and compared the trends between the half‐cells and single‐cells using linear scan voltammetry (LSV), polarization curves (IVP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. Furthermore, regression analysis was performed to identify the influential factors for examining the complex relationship between the half‐cell and single‐cell performance parameters. The study reveals, that it is highly challenging to express the performances of the catalyst and single‐cell using isolated factors. Additionally, even though the measured activity of the catalyst in a half‐cell is higher than that in the other half‐cells, the difference does not manifest significantly in the single‐cell when the conditions required for its activity are not optimized, indicating that the overall performance of the fuel cell membrane electrode assembly (MEA) is not determined solely by the catalyst.
Early‐Paleozoic mafic intrusion in North Qinling (Central China): Implication for the initiation back‐arc system along the Shangdan suture zone
Authors: Wu Sainan , Qin Jiang‐Feng , Lai Shao‐Cong , Long Xiao‐Ping , Ju Yin‐Juan , Zhang Ze‐Zhong , Wang Jiang‐Bo , Li Chunyu
Published: December 2019

The relationship between the Shangdan and Erlangping suture zone (ESZ) and the initiation stretch time of the Early Paleozoic back‐arc system in the Qinling Orogen still remains unclear. This paper reports the chronological and geochemical data of the Miaogou mafic intrusion along the southern margin of the Shangdan suture. The pyroxenite in the mafic intrusion has a zircon U–Pb age of 485 ± 5 Ma (Mean Standard Weighted Deviation (MSWD) = 0.08, n = 18). It has low SiO2 (45.41–46.02 wt%), K2O (0.42–0.44 wt%), and TiO2 (0.73–0.83 wt%) contents, high MgO (13.9–15.13 wt%) contents with high Mg# (74–77). In combination with its high clinopyroxene portion, the pyroxenite represented the accumulates from the mafic magma. Some sieve rims of the clinopyroxene indicate that the primitive pyroxenite was metasomatized by subduction‐related fluids. However, their consistent trace element and rare earth element (REE) patterns suggest that the metasomatism process has insignificant effects on their geochemical features. Zircons from the pyroxenite have positive εHf(t) (+7.18 to +11.75) values, reveal a depleted source region. In combination with its high V (322–1,093 ppm) contents, low Ti/V (10–15) ratios and smooth REE patterns, we propose that the pyroxenite was derived from metasomatized depleted mantle wedge in a back‐arc basin. In considering the duration limit (<475 Ma) of the back‐arc basin along the ESZ, we argued that the ~485 Ma Miaogou pyroxenite represented the initiation back‐arc basin in the Shangdan suture, which might represent the initial rifting of the North Qinling microcontinent induced by the northward subduction of the Shangdan Ocean.
Patient safety culture in university hospital's emergency departments: A case study
Authors: Nekoei‐Moghadam Mahmood , Raadabadi Mehdi , Heidarijamebozorgi Majid
Published: December 2019

Background

Improving patient safety culture in healthcare organization is the first step in reducing medical errors and improving patient safety. The aim of the study was to determine and to compare patient safety culture dimensions in emergency departments of selected educational hospitals of Kerman University of Medical Sciences.

Methods

This descriptive‐analytical study was conducted in 2018 in the emergency departments Shahid Bahonar, Afzalipour, Shahid Beheshti, and Shafa hospitals. Data collection was carried using the Hospital Survey of Patient Safety Culture questionnaire which includes 42 questions and 12 dimensions. Data were analyzed using descriptive and analytical statistics.

Results

The highest and lowest mean related to the organizational learning (3.96 ± 0.34) and handoffs and transitions (2.27 ± 0.55). According to independent t test, there was a significant relationship between nurse's gender and patient safety culture. Also, according to analysis of variance test, there was a significant relationship between work experience and patient safety culture.

Conclusions

The situation of patient safety culture was average at a moderate level. Development of reporting system and encouraging staff to report errors and adjusting nursing number and workload is suggested.
Electrospinning of tyrosine‐based oligopeptides: Self‐assembly or forced assembly?
Authors: Hamedani Yasaman , Macha Prathyushakrishna , Evangelista Elvira L. , Sammeta Vamshikrishna R. , Chalivendra Vijaya , Rasapalli Sivappa , Vasudev Milana C.
Published: December 2019

Short oligomeric peptides typically do not exhibit the entanglements required for the formation of nanofibers via electrospinning. In this study, the synthesis of nanofibers composed of tyrosine‐based dipeptides via electrospinning, has been demonstrated. The morphology, mechanical stiffness, biocompatibility, and stability under physiological conditions of such biodegradable nanofibers were characterized. The electrospun peptide nanofibers have diameters less than 100 nm and high mechanical stiffness. Raman and infrared signatures of the peptide nanofibers indicate that the electrostatic forces and solvents used in the electrospinning process lead to secondary structures different from self‐assembled nanostructures composed of similar peptides. Crosslinking of the dipeptide nanofibers using 1,6‐diisohexanecyanate (HMDI) improved the physiological stability, and initial biocompatibility testing with human and rat neural cell lines indicate no cytotoxicity. Such electrospun peptides open up a realm of biomaterials design with specific biochemical compositions for potential biomedical applications such as tissue repair, drug delivery, and coatings for implants.
Novel core‐shell nanocomposites based on TiO2‐covered magnetic Co3O4 for biomedical applications
Authors: Tonelli Amanda M. , Venturini Janio , Arcaro Sabrina , Henn Jeferson G. , Moura Dinara J. , Viegas Alexandre da Cas , Bergmann Carlos P.
Published: December 2019

Magnetic Co3O4 nanoparticles (NPs) have great potential for applications in biomedicine, as contrast enhancement agents for magnetic resonance imaging, or for drug delivery. Although these NPs are so attractive, their potential toxicity raises serious questions about decreasing cellular viability. In this context, Co3O4 NPs were prepared via sol–gel method and encapsulated with a layer of TiO2, a biocompatible oxide, and subjected to structural, magnetic and toxicity characterization. X‐ray diffractograms of the samples demonstrate the successful synthesis of the spinel and Raman spectroscopy confirms the coating of the Co3O4 spinel with TiO2. The Co3O4 cores showed a very intense superparamagnetic character; however, this behavior is strongly suppressed when the material is covered with TiO2. According to the neutral red uptake assay, the coating of the cores with TiO2 significantly decreases the cytotoxic character of the Co3O4 particles and, as it can be observed with the zeta (ξ) potential measurements, they form a stable colloidal dispersion at cytoplasmic pH. The effect of the thermal treatment enhances the biocompatibility even further, with no statistically significant effect on cell viability even at the highest analyzed concentration. The proposed pathway presents a successful sol–gel method for the preparation of Co3O4@TiO2 core‐shell nanoparticles. This work opens up possibilities for future application of these materials not only for magnetic resonance imaging but also in catalysis and hyperthermia.
Evaluating the lucrative role of probiotics in the aquaculture using microscopic and biochemical techniques
Authors: Noor Zohaib , Noor Mannal , Khan Imran , Khan Syed Allauddin
Published: December 2019

The present study focused to elucidate the promising role of probiotics in the fish culture, by employing microscopic and biochemical parameters to rationalize the possible outcomes. After preliminary feeding trial histopathological analysis revealed clear and visible changes in the intestinal and liver cells of CTRL (control group) compared to probiotics supplemented group, the bacterial inoculations resulted in shorten and swelled villi, while liver kupffer cells increased many folds in the CTRL. Moreover, there was clear hypertrophy and lamellar fusion in the gills tissues examined under microscope. Furthermore, intriguing results were obtained, such as a substantial increase in the weight gain, specific growth rate (%BW/day), FCE%, survival%, and improved secretions of amylase, cellulase, and protease activities. Likewise, high crude protein, fats content, while low moisture and total Ash was noticed in EXP I (Probiotics supplemented) compared to CTRL. The microscopic and biochemical analysis disclosed the positive role of probiotics on the fish health, thus we suggest its supplementations in the fish diet.
Design, synthesis, and bioactivity of nortopsentin analogues containing 1,2,4‐triazole moieties
Authors: Zhao Xinyu , Liao Ancai , Zhang Fan , Zhao Qi , Zhou Lijia , Fan Jingjing , Zhang Zheng , Wang Ziwen , Wang Qingmin
Published: December 2019

Plant diseases are serious and difficult to control. Novel and efficient pesticides are urgently needed. A series of nortopsentin analogues were designed, synthesized, and evaluated for their antiviral activities and fungicidal activities. Compound 3g with higher antiviral activity than nortopsentin D and ribavirin emerged as new antiviral lead compound. Further fungicidal activity tests revealed that nortopsentin analogues displayed broad‐spectrum fungicidal activities. Compounds 3a, 3d, and 3f displayed higher antifungal activities against Cercospora arachidicola Hori than commercial fungicides carbendazim and chlorothalonil. Current research has laid a foundation for the application of nortopsentin analogues in plant protection.
Beige FAPs Transplantation Improves Muscle Quality and Shoulder Function After Massive Rotator Cuff Tears
Authors: Lee Carlin , Liu Mengyao , Agha Obiajulu , Kim Hubert T. , Feeley Brian T. , Liu Xuhui
Published: December 2019

Rotator cuff (RC) tears are a common cause of upper extremity disability. Any tear size can result in subsequent muscle atrophy and fatty infiltration (FI). Preoperative muscle degeneration can predict repair and postoperative functional outcomes. Muscle residential fibro‐adipogenic progenitors (FAPs) are found to be capable of differentiating into beige adipocytes that release factors to promote muscle growth. This study evaluated the regenerative potential of local cell transplantation of beige FAPs to mitigate muscle degeneration in a murine massive RC tear model. Beige FAPs were isolated from muscle in UCP‐1 reporter mice by flow cytometry as UCP‐1+/Sca1+/PDGFR+/CD31−/CD45−/integrin α7−. C57/BL6J mice undergoing supraspinatus tendon tear with suprascapular nerve transection (TT + DN) received either no additional treatment, phosphate‐buffered saline injection, or beige FAP injection 2 weeks after the initial injury. Forelimb gait analysis was used to assess shoulder function with DigiGait. Mice were sacrificed 6 weeks after cell transplantation. FI, fibrosis, fiber size, vascularity were analyzed and quantified via ImageJ. Our results showed that beige FAP transplantation significantly decreased fibrosis, FI, and atrophy, enhanced vascularization compared with saline injection and non‐treatment groups. Beige FAP transplantation also significantly improved shoulder function as measured by gait analysis. This study suggests that beige‐differentiated FAPs may serve as a treatment option for RC muscle atrophy and FI, thus improving shoulder function in patients with massive RC tendon tears. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1159‐1166, 2020
Analyticity of solutions to the primitive equations
Authors: Giga Yoshikazu , Gries Mathis , Hieber Matthias , Hussein Amru , Kashiwabara Takahito
Published: December 2019

This article presents the maximal regularity approach to the primitive equations. It is proved that the 3D primitive equations on cylindrical domains admit a unique global strong solution for initial data lying in the critical solonoidal Besov space for with . This solution regularize instantaneously and becomes even real analytic for .
Falls in Progressive Supranuclear Palsy
Authors: Brown Fraser S. , Rowe James B. , Passamonti Luca , Rittman Timothy
Published: December 2019

Background

Despite falls being an almost universal clinical feature and central to the presentation and diagnostic criteria of progressive supranuclear palsy, our understanding of falls is surprisingly limited and there are few effective treatment options.

Objectives

To provide an overview of the topic of the impact, assessment, mechanism, and management of falls in progressive supranuclear palsy.

Methods

We performed a literature search for “falls” and “progressive supranuclear palsy” and included additional relevant literature known to us. We synthesized this literature with experience from clinical practice.

Results

We review current understanding of the pathophysiology of falls, highlighting the roles of the indirect pathway and the pedunculopontine nucleus. We go on to identify shortcomings in commonly used assessments to measure falls. We discuss medical and nonmedical fall prevention strategies, and finally we discuss balancing falls risk against promoting independence.

Conclusion

Falls are central to progressive supranuclear palsy presentation and diagnosis. Indirect locomotor and pedunculopontine nucleus dysfunction are thought to be the neural substrate of falls in this condition. Attempts to measure and prevent falls, by medical and nonmedical means, are currently limited. A personalized approach is advocated in the management of falls.
Recruitment and methodological issues in conducting dementia research in British ethnic minorities: A qualitative systematic review
Authors: Waheed Waquas , Mirza Nadine , Waheed Muhammed Wali , Blakemore Amy , Kenning Cassandra , Masood Yumna , Matthews Fiona , Bower Peter
Published: December 2019

Objective

Identifying existing recruitment and methodological issues within dementia research conducted in UK studies that included ethnic minorities.

Methods

We searched for and included any publication detailing dementia research in the UK that included any ethnic minority. The search results and all titles and abstracts were screened according to the inclusion criteria followed by screening of the full texts. We extracted data regarding the recruitment and methodological issues faced by the researchers. This data was combined and listed, and related issues were grouped into overarching themes and subthemes.

Results

Of 52 publications suitable for analysis, 33 provided data collated into six themes: attitudes and beliefs about dementia in ethnic minority communities, recruitment process, data collection issues, practical issues, researcher characteristics, and lack of published research and normative data. These themes allowed us to identify three areas responsible for addressing these recruitment and methodological issues: community and patient education, health services, and researchers' training.

Conclusions

This is the first review identifying recruitment and methodological issues within UK dementia research that included ethnic minorities. We now have a compilation of reported existing issues and a framework of areas responsible for addressing them and devising solutions.
A diagnostic classification version of Schizotypal Personality Questionnaire using diagnostic classification models
Authors: Xi Chongqin , Cai Yan , Peng Siwei , Lian Jie , Tu Dongbo
Published: December 2019

Objective

To obtain more precise and rich information from the measurements for schizotypal personality disorder (SPD), a cutting‐edge psychometric theory called diagnostic classification models (DCMs) was first employed in the present study to develop a diagnostic classification version of the Schizotypal Personality Questionnaire (DC‐SPQ) based on the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders.

Methods

Under the framework of DCMs, 980 college students were recruited to calibrate item parameters of the Schizotypal Personality Questionnaire. Items that fit the psychometric characteristic would be selected to compose the DC‐SPQ, prior to an analysis of its indexes.

Results

Results showed that the DC‐SPQ had high reliability and validity in both the classical test theory and DCMs, in addition to showing a sensitivity of 0.921 and a specificity of 0.841 with area under receiver operating characteristic curve = 0.936. Meanwhile, the four‐factor model proposed adequately fits with the data. More importantly, the DC‐SPQ provides not only the general‐level information similar to traditional questionnaires but also the symptom‐level information with the posterior probability, which provides an insight into delivering the individual‐specific intervention that is tailor made to schizotypal personality disorder.

Conclusions

This study demonstrates that the DC‐SPQ is very valuable for psychometric detection in that it can clarify the symptom being measured and provide more reasonable estimates.
Prevalence, dimensionality and clinical relevance of self‐disturbances and psychotic‐like experiences in Polish young adults: a latent class analysis approach.
Authors: Pionke Renata , Gidzgier Piotr , Nelson Barnaby , Gawęda Łukasz
Published: December 2019

Objectives

We aimed to investigate latent classes of psychotic‐like experiences (PLEs) and self‐disturbances (SD) and to explore mutual overlapping between derived subgroups. Further, our goal was to investigate class membership relationship with an exposure to childhood trauma and different psychopathological factors such as cognitive biases, depression, insomnia, psychiatric diagnosis and lifetime suicidality.

Methods

Participants consist of 3167 non‐clinical adults. We performed two latent class analyses (LCA), for PLEs and SD separately, to identify subgroups of individuals with different profiles on PLEs and SD. Associations between psychopathological factors and latent class membership were examined using multinomial logistic regression analysis.

Results

LCA produced 5 classes within SD and 3 classes within PLEs. Class of the highest endorsement of SD showed 53% overlap with class of the highest endorsement of PLEs. The highest risk of belonging to High Class for both SD and PLEs was associated in particular with depression, cognitive biases and insomnia. Trauma emerged as a significant predictor only for PLEs classes.

Conclusions

Our findings confirm that high PLEs and SD co‐occur and are concentrated in a relatively small number of individuals, at least in the general population. Their combination may capture the highest risk of psychosis in the general population.
Wave scattering and diffraction of subsurface cavities in layered half‐space for incident SV‐P and SH waves
Authors: Lin Gao , Li Zhi‐yuan , Li Jian‐bo
Published: December 2019

A novel approach is proposed to deal with the problem of wave scattering and diffraction of subsurface cavities embedded in stratified half‐space. The subsurface cavity with complex surroundings is treated as a substructure. The continuity condition at the interface between the substructure and the far field of stratified half‐space is maintained by applying a free‐field approach. As the boundary of the free‐field ground is regular, the construction of the dynamic matrices and the evaluation of the wave input on the interface become considerably easier. Based on the previous work with some improvement, a novel approach for evaluation of Green's functions in stratified half‐space is presented. The wave equation is decoupled into the one for SV‐P wave components and the other one for SH wave component. The precise integration technique ensures high accuracy of the solution of wave equations. The layer merging technique and the dual form equation make it possible to obtain Green's function in closed‐form solution of matrix equations. Numerical examples validate accuracy and efficiency of the proposed approach.
On regularized Hermitian splitting iteration methods for solving discretized almost‐isotropic spatial fractional diffusion equations
Authors: Bai Zhong‐Zhi , Lu Kang‐Ya
Published: December 2019

The shifted finite‐difference discretization of the one‐dimensional almost‐isotropic spatial fractional diffusion equation results in a discrete linear system whose coefficient matrix is a sum of two diagonal‐times‐Toeplitz matrices. For this kind of linear systems, we propose a class of regularized Hermitian splitting iteration methods and prove its asymptotic convergence under mild conditions. For appropriate circulant‐based approximation to the corresponding regularized Hermitian splitting preconditioner, we demonstrate that the induced fast regularized Hermitian splitting preconditioner possesses a favorable preconditioning property. Numerical results show that, when used to precondition Krylov subspace iteration methods such as generalized minimal residual and biconjugate gradient stabilized methods, the fast preconditioner significantly outperforms several existing ones.
Quantitative study of the substituent effects on the electronic absorption and fluorescence spectra of coumarins
Authors: Cisse Lamine , Djande Abdoulaye , Capo‐Chichi Martine , Khonté Abdourahmane , Bakhoum Jean‐Pierre , Delattre François , Yoda Jules , Saba Adama , Tine Alphonse , Aaron Jean‐Jacques
Published: December 2019

Because of their important fluorescence properties, coumarins are widely applied in sensing devices. In this paper, the electronic inductive, mesomeric, and electromeric substituent effects on the electronic absorption and fluorescence spectra of 11 substituted coumarins, including NH2, NMe2, NEt2, OH, CF3, CH3, COOH, Cl, and Br substituents, have been quantitatively studied by means of structure‐reactivity relationships. We have applied the Hammett, Brown‐Okamoto, and Yukawa‐Tsuno correlations to the coumarins electronic absorption and fluorescence spectra wavenumbers and Stokes shifts. The Stokes shift of coumarins decreased when the electron‐donor inductive/mesomeric power of the substituent increased. This Stokes shift decrease was more pronounced when the solvent polarity increased, which might be explained by the electromeric effect increase.
Josephson Effect in a T‐Shaped Triple‐Quantum‐Dot Structure: π‐Junction Behavior and Two‐Stage Kondo Effect
Authors: Zhong Su-Rui , Jin Li-Hui , Yang Chuan-Jing , Li Xue-Si , Yi Guang-Yu
Published: December 2019

By means of the exact diagonalization approach, the interplay between the Josephson effect and the two‐stage Kondo physics in a T‐shaped triple‐quantum‐dot (TQD) junction is theoretically investigated. It is found that by adjusting the interdot couplings, the Josephson current exhibits the rich 0–π transition behaviors. These results originate from the mutual competition and cooperation of Cooper‐pair correlation and two‐stage Kondo correlation in the system. Moreover, due to the occurrence of two‐stage Kondo effect, the Josephson phase transition can be adjusted in a precise manner. It is believed that this work can help to understand the supercurrent phase transition in the QD‐based Josephson junctions.
A Deep Carbon‐Related Acceptor Identified through Photo‐Induced Electron Paramagnetic Resonance
Authors: Paudel Subash , Zvanut Mary Ellen , Iwinska Malgorzata , Sochacki Tomasz , Bockowski Michal
Published: December 2019

Herein, a carbon‐related point defect in thick free‐standing carbon‐doped GaN substrates grown by halide chemical vapor deposition is examined. Carbon is intentionally introduced to concentrations between 2 × 1017 and 1019 cm−3, and the number of point defects is proportional to the carbon concentration. The carbon center is detected using electron paramagnetic resonance spectroscopy after photo‐excitation with light greater than 2.8 eV. Simultaneous monitoring of the defect and a shallow donor confirms that the excitation occurs via removal of an electron from the deep carbon‐related acceptor and subsequent capture by the shallow donor. The study indicates that the defect level for the carbon defect is at least 0.7 eV above the valence band edge and therefore an excellent candidate for growth of semi‐insulating GaN.
Correlation between Hall Mobility and Optical Mobility in Aluminum‐Doped ZnO Films via Boundary Scatterings and Estimation of Donor Compensation Ratio
Authors: Ghosh Shuvaraj , Basak Durga
Published: December 2019

A correlation between the Hall and optical mobility via boundary (BND) scatterings arising from grain as well as surface boundaries in radio frequency (RF) sputtered Al‐doped ZnO (AZO) films done by a comprehensive study on the electrical carrier transport and near infrared optical transmittance properties. AZO films with thicknesses from 100 to 1550 nm are grown by sputtering 1.9 wt% Al2O3‐doped ceramic target under identical growth conditions. The Hall measurement shows an increase in the carrier concentration value from 6.93 × 1020 to 1.1 × 1021 cm−3 with a mobility value (μHall) in the range of 4.98–10.3 cm2 (V s)−1 as the thickness increases. Unprecedentedly, it is shown that the optical mobility value (μopt) calculated using Drude theory is higher than that of the μHall up to a film thickness of ≈1000 nm beyond which both the values merges. Though the carrier concentration is higher than 5 × 1020 cm−3, BND scattering playing an important role in addition to the in‐grain scattering below a thickness of ≈1000 nm is demonstrated. Considering the BND scattering, donor compensation ratio is calculated and is uniquely found to vary with the film thickness.
Bivariate semiparametric control charts for simultaneous monitoring of process mean and variance
Authors: Koutras Markos V. , Sofikitou Elisavet M.
Published: December 2019

In the present article, two semiparametric bivariate control charts are presented, which use order statistics and are effective in jointly monitoring of possible shifts in the process mean and/or variance. To achieve that both the median location (or more generally the location of a specific order statistic) and the number of specific observations of the test sample lying between the control limits are taken into account. The false alarm rate and the in‐control average run length are not affected by the marginal distributions, while the effect of the dependence structure on them is negligible; therefore, they can be used as fully nonparametric charts. A performance‐comparison study is carried out, and an illustrative example is provided using a real‐world data set.
Hybrid of Graphitic Carbon Nitride and Palladated Magnetic Carbon Dot: An Efficient Catalyst for Coupling Reaction
Authors: Mohammadi Leila , Heravi Majid M. , Sadjadi Samahe , Malmir Masoumeh
Published: December 2019

To take advantage of the properties of graphitic carbon nitrides and carbon quantum dots, a novel hybrid system was designed based on the synthesis and palladating of magnetic carbon quantum dots followed by hydrothermal treatment with graphitic carbon nitrides. The resulting hybrid, g‐C3N4‐Pd/CQDs@Fe, was then utilized as an efficient catalyst for promoting ligand and co‐catalyst‐free Sonogashira coupling reaction under mild reaction condition in aqueous media. Not only the catalyst could catalyze the reaction of broad range of the substrates, but also it showed good recyclability and could be easily recovered by using an external magnet and reused for several times. The study of the catalytic activities of palladated graphitic carbon nitride and magnetic carbon quantum dots confirmed that the hybrid system was more efficient catalyst compared to each component.
The Spirit of Blumer's Method as a Guide to Sociological Discovery
Authors: Schwalbe Michael
Published: December 2019

Herbert Blumer did not offer textbook‐style instructions for how to do research. What he offered, in his classic 1969 essay “The Methodological Position of Symbolic Interactionism,” is a broad account of what research must entail to accord with symbolic interactionist premises that human social life depends on meanings, interpretation, and interaction. Blumer's essay also voices a spirit of research that is ardently empirical, sociological, and creative. It is this spirit, I argue, that holds great value for guiding sociological research toward fresh discoveries. I make this argument by reviewing what Blumer meant by exploration and inspection, and then drawing out five Blumerian principles of inquiry. By embracing these principles we can avoid the problems of inadvertent theorizing, unreflective mesearch, analytic foreclosure, excessive subjectivism, and aprocessuality. I also suggest how we can enhance the sociological value of Blumer's method by paying more attention to power, inequality, and our own institutional biases. Embracing the spirit of Blumer's method, I conclude, can help a new generation of symbolic interactionists do more imaginative and insightful work.
Dynamic Surface Control Using Fuzzy Logic Systems for Uncertain, Strict‐feedback, Nonlinear Systems with Unknown Control Directions
Authors: Shi Wenrui , Xu Lijia , Chen Sanyan
Published: December 2019

This paper proposes an adaptive tracking control design procedure for a class of uncertain, strict‐feedback, nonlinear systems in the presence of unknown structure uncertainties, external disturbances, and unknown control directions. To stabilize the systems, fuzzy logic systems are utilized to approximate the unknown structure uncertainties, and the weight matrices and the upper bounds of approximation errors of fuzzy logic systems are not supposed to be known a priori. Then, to avoid the problem of ‘explosion of terms’, a dynamic surface control approach is employed by introducing a first‐order low‐pass filter. Furthermore, the issue of unknown control directions is solved by inserting the Nussbaum function. In addition, the projection operator is applied in the adaptation laws to guarantee the boundedness of the estimated parameters. Finally, simulation results are presented to show the validity of the proposed control strategy. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
The crystallization, thermal and mechanical properties of nano‐Sb2O3 filled poly(butylene terephthalate)
Authors: Xu Jianlin , Kang Chenghu , Niu Lei , Xu Chengcheng , Zhang Jianbin , Ma Jiqiang
Published: December 2019

Nano‐Sb2O3 particles were modified by a combination modifier of cetyltrimethyl ammonium bromide (CTAB) and KH‐560 via the mechanochemical method based on high‐energy ball milling. Then, the testing specimens of the nano‐Sb2O3/PBT composites of differing compositions were prepared by melting blending technology. The crystallization, thermal, and mechanical properties of composites were characterized by X‐ray diffraction, differential scanning calorimetry, thermogravimetric analyzer, and mechanical performance test. The tensile and impact fracture surfaces of composites were determined by scanning electron microscopy. Besides, the influence of the Sb2O3 nanoparticles surface modification on crystallinity, mechanical properties of the composites, and the interfacial adhesion between nano‐Sb2O3 and PBT was systematically investigated. The results indicate that the main crystalline characteristics of PBT matrix remain unchanged in the nanocomposites. However, the addition of nano‐Sb2O3 particles plays a heterogeneous nucleation and can effectively improve the crystallization of PBT matrix. In addition, the compound modification of the nano‐Sb2O3 can effectively enhance mechanical properties of the composites and interfacial interaction between nano‐Sb2O3 and PBT. The enhanced fracture properties in the nanocomposites were caused by the assisted void formation at the edge of the nano‐Sb2O3 particle. When the nano‐Sb2O3 mass fraction is 3%, the composites show excellent comprehensive performance. The interfacial adhesion parameter B and the half‐debonding angle θ of composites were assessed to quantitatively characterize the interfacial adhesion strength between nano‐Sb2O3 and PBT. Finally, the reinforcement and toughening mechanisms were described. J. VINYL ADDIT. TECHNOL., 26:268–281, 2020. © 2019 Society of Plastics Engineers
An implementation and numerical experiments of the FEM‐BEM coupling for the elastodynamic wave equation in 3D
Authors: Eberle Sarah
Published: December 2019

In this paper we deal with an implementation as well as numerical experiments for the coupling of interior and exterior problems of the elastodynamic wave equation with transparent boundary conditions in 3D as described in a previous paper by this author. In more detail, the FEM‐BEM‐coupling as well as the time discretization by using leapfrog and convolution quadrature is considered. Our aim is to provide an insight into the necessary steps of the implementation. Based on this, we present numerical experiments for a non‐convex domain and analyze the errors.
Relating amplitude and PDF factorisation through Wilson-line geometries
Authors: Falcioni Giulio , Gardi Einan , Milloy Calum
Published: December 2019

Abstract

We study long-distance singularities governing different physical quantities involving massless partons in perturbative QCD by using factorisation in terms of Wilson-line correlators. By isolating the process-independent hard-collinear singularities from quark and gluon form factors, and identifying these with the ones governing the elastic limit of the perturbative Parton Distribution Functions (PDFs) — δ(1 − x) in the large-x limit of DGLAP splitting functions — we extract the anomalous dimension controlling soft sin- gularities of the PDFs, verifying that it admits Casimir scaling. We then perform an independent diagrammatic computation of the latter using its definition in terms of Wil- son lines, confirming explicitly the above result through two loops. By comparing our eikonal PDF calculation to that of the eikonal form factor by Erdogan and Sterman and the classical computation of the closed parallelogram by Korchemsky and Korchemskaya, a consistent picture emerges whereby all singularities emerge in diagrammatic configurations localised at the cusps or along lightlike lines, but where distinct contributions to the anomalous dimensions are associated with finite (closed) lightlike segments as compared to infinite (open) ones. Both are relevant for resumming large logarithms in physical quantities, notably the anomalous dimension controlling Drell-Yan or Higgs production near threshold on the one hand, and the gluon Regge trajectory controlling the high-energy limit of partonic scattering on the other.
Automated formal synthesis of provably safe digital controllers for continuous plants
Authors: Abate Alessandro , Bessa Iury , Cordeiro Lucas , David Cristina , Kesseli Pascal , Kroening Daniel , Polgreen Elizabeth
Published: December 2019

We present a sound and automated approach to synthesizing safe, digital controllers for physical plants represented as time-invariant models. Models are linear differential equations with inputs, evolving over a continuous state space. The synthesis precisely accounts for the effects of finite-precision arithmetic introduced by the controller. The approach uses counterexample-guided inductive synthesis: an inductive generalization phase produces a controller that is known to stabilize the model but that may not be safe for all initial conditions of the model. Safety is then verified via bounded model checking: if the verification step fails, a counterexample is provided to the inductive generalization, and the process further iterates until a safe controller is obtained. We demonstrate the practical value of this approach by automatically synthesizing safe controllers for physical plant models from the digital control literature.
Revealing factors determining immunodominant responses against dominant epitopes
Authors: Ritmahan Wannisa , Kesmir Can , Vroomans Renske M.A.
Published: December 2019

Upon recognition of peptide-MHC complexes by T cell receptors (TCR), the cognate T cells expand and differentiate into effector T cells to generate protective immunity. Despite the fact that any immune response generates a diverse set of TCR clones against a particular epitope, only a few clones are highly expanded in any immune response. Previous studies observed that the highest frequency clones usually control viral infections better than subdominant clones, but the reasons for this dominance among T cell clones are still unclear. Here, we used publicly available TCR amino acid sequences to study which factors determine whether a response becomes immunodominance (ID) per donor; we classified the largest T cell clone as the epitope-specific dominant clone and all the other clones as subdominant responses (SD). We observed a distinctively hydrophobic CDR3 in ID responses against a dominant epitope from influenza A virus, compared to the SD responses. The common V-J combinations were shared between ID and SD responses, suggesting that the biased V-J recombination events are restricted by epitope specificity; thus, the immunodominance is not directly determined by a bias combination of V and J genetic segments. Our findings reveal a close similarity of global sequence properties between dominant and subdominant clones of epitope-specific responses but detectable distinctive amino acid enrichments in ID. Taken together, we believe this first comparative study of immunodominant and subdominant TCR sequences can guide further studies to resolve factors determining the immunodominance of antiviral as well as tumor-specific T cell responses.
Hierarchical stochastic graphlet embedding for graph-based pattern recognition
Authors: Dutta Anjan , Riba Pau , Lladós Josep , Fornés Alicia
Published: December 2019

Despite being very successful within the pattern recognition and machine learning community, graph-based methods are often unusable because of the lack of mathematical operations defined in graph domain. Graph embedding, which maps graphs to a vectorial space, has been proposed as a way to tackle these difficulties enabling the use of standard machine learning techniques. However, it is well known that graph embedding functions usually suffer from the loss of structural information. In this paper, we consider the hierarchical structure of a graph as a way to mitigate this loss of information. The hierarchical structure is constructed by topologically clustering the graph nodes and considering each cluster as a node in the upper hierarchical level. Once this hierarchical structure is constructed, we consider several configurations to define the mapping into a vector space given a classical graph embedding, in particular, we propose to make use of the stochastic graphlet embedding (SGE). Broadly speaking, SGE produces a distribution of uniformly sampled low-to-high-order graphlets as a way to embed graphs into the vector space. In what follows, the coarse-to-fine structure of a graph hierarchy and the statistics fetched by the SGE complements each other and includes important structural information with varied contexts. Altogether, these two techniques substantially cope with the usual information loss involved in graph embedding techniques, obtaining a more robust graph representation. This fact has been corroborated through a detailed experimental evaluation on various benchmark graph datasets, where we outperform the state-of-the-art methods.
Single and ensemble classifiers for defect prediction in sheet metal forming under variability
Authors: Dib M. A. , Oliveira N. J. , Marques A. E. , Oliveira M. C. , Fernandes J. V. , Ribeiro B. M. , Prates P. A.
Published: December 2019

This paper presents an approach, based on machine learning techniques, to predict the occurrence of defects in sheet metal forming processes, exposed to sources of scatter in the material properties and process parameters. An empirical analysis of performance of ML techniques is presented, considering both single learning and ensemble models. These are trained using data sets populated with numerical simulation results of two sheet metal forming processes: U-Channel and Square Cup. Data sets were built for three distinct steel sheets. A total of eleven input features, related to the mechanical properties, sheet thickness and process parameters, were considered; also, two types of defects (outputs) were analysed for each process. The sampling data were generated, assuming that the variability of each input feature is described by a normal distribution. For a given type of defect, most single classifiers show similar performances, regardless of the material. When comparing single learning and ensemble models, the latter can provide an efficient alternative. The fact that ensemble predictive models present relatively high performances, combined with the possibility of reconciling model bias and variance, offer a promising direction for its application in industrial environment.
Embedded axonal fiber tracts improve finite element model predictions of traumatic brain injury
Authors: Hajiaghamemar Marzieh , Wu Taotao , Panzer Matthew B. , Margulies Susan S.
Published: December 2019

With the growing rate of traumatic brain injury (TBI), there is an increasing interest in validated tools to predict and prevent brain injuries. Finite element models (FEM) are valuable tools to estimate tissue responses, predict probability of TBI, and guide the development of safety equipment. In this study, we developed and validated an anisotropic pig brain multi-scale FEM by explicitly embedding the axonal tract structures and utilized the model to simulate experimental TBI in piglets undergoing dynamic head rotations. Binary logistic regression, survival analysis with Weibull distribution, and receiver operating characteristic curve analysis, coupled with repeated k-fold cross-validation technique, were used to examine 12 FEM-derived metrics related to axonal/brain tissue strain and strain rate for predicting the presence or absence of traumatic axonal injury (TAI). All 12 metrics performed well in predicting of TAI with prediction accuracy rate of 73–90%. The axonal-based metrics outperformed their rival brain tissue-based metrics in predicting TAI. The best predictors of TAI were maximum axonal strain times strain rate (MASxSR) and its corresponding optimal fraction-based metric (AF-MASxSR7.5) that represents the fraction of axonal fibers exceeding MASxSR of 7.5 s−1. The thresholds compare favorably with tissue tolerances found in in–vitro/in–vivo measurements in the literature. In addition, the damaged volume fractions (DVF) predicted using the axonal-based metrics, especially MASxSR (DVF = 0.05–4.5%), were closer to the actual DVF obtained from histopathology (AIV = 0.02–1.65%) in comparison with the DVF predicted using the brain-related metrics (DVF = 0.11–41.2%). The methods and the results from this study can be used to improve model prediction of TBI in humans.