bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and analysis of nickel ferrite resonator antenna for C band applications
Authors: da Silva Isaac Barros Tavares , D'Assunção Adaildo Gomes , de Oliveira João Bosco Lucena , de Holanda Samanta Mesquita , Cordeiro Carlos Henrique Nascimento
Published: February 2021

This article shows the design of dielectric resonator antenna with nickel ferrite as dielectric material. Its main characteristics and measurements are described. Nickel ferrite was synthetized by sol–gel modified by ionic coordination reaction technique. Calcination was performed at 1100°C (10 h, 10°C/min step), followed by compression procedure at 227 MPa, to manufacture the bulk. Sintering process was applied at calcination temperature, for 4 h, to ensure bulk's physical resistance, and its electrical characterization was performed for antenna design and simulations. Simulated radiation patterns are presented, as reflection coefficient, which is compared with measurements. Measured reflection coefficient presented good agreement with performed simulations, with a difference of 0.74% in resonance frequency. Simulated radiation patterns also presented good results, with relatively high gain in co‐polarization planes, 2.11 dB for E plane, and low cross‐polarization E plane value, −47 dB.
Highly sensitive temperature sensor based on multimode‐interference fiber structure with gel cladding
Authors: Sakata Hajime , Okada Kengo , Mochizuki Jun
Published: February 2021

We present a temperature‐sensitive, single‐mode–multimode–single‐mode (SMS) fiber structure with an index‐matching gel as a cladding material in a multimode segment. A silica core with the surrounding gel is supported straight by a thin glass tube to produce a bandpass transmission response. The passband wavelength shifts by 96 nm from 1624.5 to 1528.5 nm as the temperature increased from 40 to 200°C. The maximum sensitivity obtained is 2 nm/°C in the temperature range 40–70°C, whereas the minimum sensitivity is 0.13 nm/°C in the temperature range 125–200°C. The SMS fiber structure, including the gel cladding, allows high operating temperatures and high thermal sensitivities.
A multicompartment model for intratumor tissue‐specific analysis of DCE‐MRI using non‐negative matrix factorization
Authors: Xie Yuhai , Zhao Jun , Zhang Puming
Published: February 2021

Purpose

A pharmacokinetic analysis of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) data is subject to inaccuracy and instability partly owing to the partial volume effect (PVE). We proposed a new multicompartment model for a tissue‐specific pharmacokinetic analysis in DCE‐MRI data to solve the PVE problem and to provide better kinetic parameter maps.

Methods

We introduced an independent parameter named fractional volumes of tissue compartments in each DCE‐MRI pixel to construct a new linear separable multicompartment model, which simultaneously estimates the pixel‐wise time‐concentration curves and fractional volumes without the need of the pure‐pixel assumption. This simplified convex optimization model was solved using a special type of non‐negative matrix factorization (NMF) algorithm called the minimum‐volume constraint NMF (MVC‐NMF).

Results

To test the model, synthetic datasets were established based on the general pharmacokinetic parameters. On well‐designed synthetic data, the proposed model reached lower bias and lower root mean square fitting error compared to the state‐of‐the‐art algorithm in different noise levels. In addition, the real dataset from QIN‐BREAST‐DCE‐MRI was analyzed, and we observed an improved pharmacokinetic parameter estimation to distinguish the treatment response to chemotherapy applied to breast cancer.

Conclusion

Our model improved the accuracy and stability of the tissue‐specific estimation of the fractional volumes and kinetic parameters in DCE‐MRI data, and improved the robustness to noise, providing more accurate kinetics for more precise prognosis and therapeutic response evaluation using DCE‐MRI.
Three‐dimensional spatially resolved phase graph framework
Authors: Gao Xiang , Kiselev Valerij G. , Lange Thomas , Hennig Jürgen , Zaitsev Maxim
Published: February 2021

Purpose

An open‐source spatially resolved phase graph framework is proposed for simulating arbitrary pulse sequences in the presence of piece‐wise constant gradients with arbitrary orientations in three dimensions. It generalizes the extended phase graph algorithm for analysis of nonperiodic sequences while preserving its efficiency, and is able to estimate the signal modulation in the 3D spatial domain.

Methods

The framework extends the recursive magnetization‐evolution algorithm to account for anisotropic diffusion and exploits a novel 3D k‐space grid‐merging method to balance the computational effort and memory requirements against acceptable simulation errors. A new postsimulation module is proposed to track and visualize the signal evolution both in the k‐space and in the image domain, which can be used for simulating image artifacts or finding frequency‐response profiles. To illustrate the developed technique, three examples are presented: (1) fast off‐resonance calculation for dictionary building in MR fingerprinting, (2) validation of a steady‐state sequence with quasi‐isotropic diffusion weighting, and (3) investigation of the magnetization evolution in PRESS‐based spectroscopic imaging.

Results

The grid‐merging algorithm of the proposed framework demonstrates high calculation efficiency exemplified by frequency‐response simulation of pseudo steady‐state or diffusion‐weighted steady‐state sequences. It further helps to visualize the signal evolution in PRESS‐based sequences.

Conclusions

The proposed simulation framework has been validated based on several different example applications for analyzing signal evolution in the frequency and spatial domain.
Prevalence of high‐risk bladder categorization with prenatal and postnatal myelomeningocele repair types
Authors: Gerber Jonathan A. , Stocks Blair T. , Zhu Huirong , Castillo Heidi , Castillo Jonathan , Borden Alexandra N. , Tu Duong D. , Whitehead William E. , Austin Paul F.
Published: February 2021

Introduction

Urologic substudies of prenatal myelomeningocele (MMC) closure have focused primarily on continence without significant clinical benefit. Fetoscopic MMC repair (FMR) is a newer form of prenatal intervention and touts added benefits to the mother, but urological outcomes have yet to be analyzed. We set out to focus on bladder safety rather than continence and examined bladder outcomes with different prenatal MMC repairs (FMR and prenatal open [POMR]) and compared bladder‐risk‐categorization to traditional postnatal repair (PSTNR).

Methods

An IRB‐approved retrospective analysis of all patients undergoing all forms of MMC repairs with inclusion and exclusion criteria based on the MOMS trial was performed. Bladder safety assessment required initial urodynamic studies (UDS), renal bladder ultrasound (RBUS), and/or voiding cystourethrogram (VCUG) within the 1st year of life. Follow‐up analyses within the cohorts required follow‐up studies within 18 months after initial evaluations. Outcomes assessed included bladder‐risk‐categorization based on the CDC UMPIRE study (high, intermediate, and safe), hydronephrosis (HN), and vesicoureteral reflux (VUR). A single reader evaluated each UDS.

Results

Initial UDS in 93 patients showed that the prevalence of high‐risk bladders were 35% FMR versus 36% PSTNR and 60% POMR. Follow‐up UDS showed only 8% of FMR were high‐risk compared to 35% POMR and 36% PSTNR. Change from initial to follow‐up bladder‐risk‐category did not reach significance (p = .0659); however, 10% PSTNR worsened to high‐risk on follow‐up, compared to none in either prenatal group. Subanalysis of follow‐up UDS between the prenatal cohorts also was not significant (p = .055). Only 8% of FMR worsened or stayed high‐risk compared to 35% with POMR (p = .1). HN was significantly different at initial and subsequent follow up between the groups with the least in the FMR group.

Conclusions

Early outcome UDS analyses demonstrated lower incidence of high‐risk bladders in FMR patients with a trend toward clinically significant improvement compared to POMR in regard to all evaluated metrics. Larger, prospective, confirmatory studies are needed to further evaluate the potential benefits on FMR on bladder safety and health.
Demand estimation of mass‐gathering healthcare in developing countries: The case of Kumbh Mela in India
Authors: Zhao Tiancheng , Ye Han , Mukherjee Ujjal Kumar , Chhajed Dilip
Published: February 2021

A mass‐gathering is defined as a congregation of a relatively large number of people in a specific location for a specific purpose over a short duration of time. Managing Mass‐Gathering Healthcare (MGH), especially in resource‐constrained regions, is a key policy challenge. Planning and preparation for MGH require understanding the sources, and estimation of demand. We propose a spatio‐temporal Poisson point process model for MGH demand estimation that considers the associated risk factors. We analyze admissions data from a multi‐specialty hospital in Ujjain, India, spanning a period before, during, and after Kumbh Mela, one of the larger religious gatherings globally. The results show that the effect of mass‐gathering on hospital admissions is heterogeneous across disease groups. We identify key socio‐economic and healthcare infrastructural factors that are associated with MGH demand. We establish the external‐validity of the results by demonstrating that mass‐gatherings generally increase the spatial dependence across regions, particularly where availability of healthcare infrastructure is relatively low. Finally, we discuss policy insights for managing MGH.
Effect of compression garments on muscle perfusion in delayed‐onset muscle soreness: A quantitative analysis using intravoxel incoherent motion MR perfusion imaging
Authors: Riexinger Andreas , Laun Frederik Bernd , Höger Svenja Alina , Wiesmueller Marco , Uder Michael , Hensel Bernhard , Forst Raimund , Hotfiel Thilo , Heiss Rafael
Published: February 2021

The aim of this prospective cohort study was to evaluate the effect of compression garments under resting conditions and after the induction of delayed‐onset muscle soreness (DOMS) by MR perfusion imaging using intravoxel incoherent motion (IVIM). Magnetic resonance imaging of both lower legs of 16 volunteers was performed before and after standardized eccentric exercises that induced DOMS. A compression garment (21–22 mmHg) was worn during and for 6 h after exercise on one randomly selected leg. IVIM MR imaging, represented as total muscle perfusion D*f, perfusion fraction f and tissue diffusivity D, were compared between baseline and directly, 30 min, 6 h and 48 h after exhausting exercise with and without compression. Creatine kinase levels and T2‐weighted images were acquired at baseline and after 48 h. DOMS was induced in the medial head of the gastrocnemius muscle (MGM) in all volunteers. Compression garments did not show any significant effect on IVIM perfusion parameters at any time point in the MGM or the tibialis anterior muscle (p > 0.05). Microvascular perfusion in the MGM increased significantly in both the compressed and noncompressed leg between baseline measurements and those taken directly after and 30 min after the exercise: the relative median f increased by 31.5% and 24.7% in the compressed and noncompressed leg, respectively, directly after the exercise compared with the baseline value. No significant change in tissue perfusion occurred 48 h after the induction of DOMS compared with baseline. It was concluded that compression garments (21–22 mmHg) do not alter microvascular muscle perfusion at rest, nor do they have any significant effect during the regeneration phase of DOMS. In DOMS, only a short‐term effect of increased muscle perfusion (30 min after exercise) was observed, with normalization occurring during regeneration after 6–48 h. The normalization of perfusion independently of compression after 6 h may have implications for diagnostic and therapeutic strategies and for the better understanding of pathophysiological pathways in DOMS.
Effect of a brief motivational intervention in the immediate postpartum period on breastfeeding self‐efficacy: Randomized controlled trial
Authors: Franco‐Antonio Cristina , Santano‐Mogena Esperanza , Sánchez‐García Pablo , Chimento‐Díaz Sara , Cordovilla‐Guardia Sergio
Published: February 2021

Brief motivational intervention (bMI) is a therapeutic approach that encourages self‐efficacy and may have a positive effect on breastfeeding self‐efficacy (BSE). The purpose of this study was to analyze the effectiveness of a bMI in increasing BSE in women who started breastfeeding in the immediate postpartum period and to explore the roles of general self‐efficacy and other baseline variables in this relationship. A randomized, parallel‐group clinical trial was carried out. A bMI was compared with an educational session on breastfeeding. Changes in BSE and its dimensions and the interaction and mediation/moderation of general self‐efficacy and other variables were analyzed. BSE increased in the bMI group from a mean baseline score of 59.14 (±9.35) to 64.62 (±7.91) at 1st month (p < 0.001). An interaction was found in that only women with higher education had an improvement in BSE during the follow‐up period that was attributable to the bMI (mean difference between the bMI and the attention control group: 18.25 (95% confidence interval: 5.86–30.19; p = 0.006). This interaction was not found for the changes produced in the intrapersonal thoughts dimension of BSE, whose scores were higher in the bMI group at 3 and 6 months. General self‐efficacy exerted a moderating effect on the association of bMI with BSE change. The effect of bMI was no longer significant when the general self‐efficacy score was above 84. Thus, bMI is effective in increasing BSE. This effectiveness was limited by the mother's educational level and moderated by baseline general self‐efficacy.
A Quantitative Molecular Orbital Perspective of the Chalcogen Bond
Authors: de Azevedo Santos Lucas , van der Lubbe Stephanie C. C. , Hamlin Trevor A. , Ramalho Teodorico C. , Matthias Bickelhaupt F.
Published: February 2021

We have quantum chemically analyzed the structure and stability of archetypal chalcogen‐bonded model complexes D2Ch⋅⋅⋅A− (Ch = O, S, Se, Te; D, A = F, Cl, Br) using relativistic density functional theory at ZORA‐M06/QZ4P. Our purpose is twofold: (i) to compute accurate trends in chalcogen‐bond strength based on a set of consistent data; and (ii) to rationalize these trends in terms of detailed analyses of the bonding mechanism based on quantitative Kohn‐Sham molecular orbital (KS‐MO) theory in combination with a canonical energy decomposition analysis (EDA). At odds with the commonly accepted view of chalcogen bonding as a predominantly electrostatic phenomenon, we find that chalcogen bonds, just as hydrogen and halogen bonds, have a significant covalent character stemming from strong HOMO−LUMO interactions. Besides providing significantly to the bond strength, these orbital interactions are also manifested by the structural distortions they induce as well as the associated charge transfer from A− to D2Ch.
Synthesis of Tetra‐Substituted Trifluoromethyl‐3,1‐Benzoxazines by Transition‐Metal‐Catalyzed Decarboxylative Cyclization of N‐Benzoyl Benzoxazinones
Authors: Uno Hiroto , Fujimoto Daichi , Harada Kyosuke , Tanaka Chika , Shibata Norio
Published: February 2021

Efficient synthesis of N,O‐heterocyclic tetra‐substituted trifluoromethyl‐3,1‐benzoxazines via a transition‐metal‐catalyzed decarboxylative intramolecular cyclization was achieved. The decarboxylation of N‐benzoyl trifluoromethyl‐benzoxazinones generated the amide oxygen nucleophile, allowing a selective internal C1‐attack on Pd‐ or Cu‐coordinated zwitterions, affording medicinally attractive tetra‐substituted vinyl‐ or ethynyl‐trifluoromethyl‐3,1‐benzoxazines. This protocol can be applied to the synthesis of perfluoroalkyl‐ and non‐fluorinated 3,1‐benzoxazines.
Understanding the panorama of sexuality and gender identity with an emphasis on transgender persons and the impact of intervention through the rights‐based counseling approach: A case study
Authors: Jena Saswati
Published: February 2021

Identity of any individual creates the path for future to function and liberty of thought and expression unwrap tremendous possibilities. If one's identity is denied or altered then both path and possibilities become obscure. One society cannot show its prominence and accomplishments, if some sections of its population are repressed and neglected. Sexually minority groups and more specifically transgender community is one of such repressed and oppressed communities till date in India. A transgender is an individual, who identifies with a different gender other than the sex assigned at birth, and in India, for the very first time, they were officially counted in 2011 census, and the number was approximately 5,00,000. The present study emphasized to understand the canopy of sexuality and gender identity with a focus on transgender persons. As there is much ambiguity, confusion, and ignorance among people, these sexual minority communities become easy targets of stigma, discrimination, bias, harassment in multiple levels, and they become vulnerable to have disturbed mental health and well‐being. At this juncture, Rights‐based Counseling approach has been established as an effective intervention program to liberate the fragile self‐concept and to safeguard the mental health of this client. It stresses on assuring the dignity of the individual irrespective of class, caste, creed, gender, and religion and to fight for one's rights.
Scientifically framed gene drive communication perceived as credible but riskier
Authors: MacDonald Edith A. , Edwards Eric D. , Balanovic Jovana , Medvecky Fabien
Published: February 2021

Humans have caused a catastrophic decline to animal species and look to emerging technologies to stop the decline. Gene drive is a potential tool that may eradicate invasive rodents known for their devastating impact on native animals. The use of gene drive will be significantly influenced by public opinion and support, thus early dialogue with society is needed.

Framing is a communication technique in which certain beliefs or values are emphasized that resonate with the target audience. Framing may increase how much people objectively think about new information and update their opinions; framing may mitigate emotive and polarising public opinion of contentious topics.

Four framed articles were developed that aligned to values of four pre‐identified segments (scientific, humanitarian, pragmatic and individualistic). A representative sample of New Zealanders (n = 1,600) read two frames (one aligning to their segment and one to another segment) and were surveyed. Four constructs were measured: (a) public support for gene drive for conservation gains; (b) motivated reasoning (how fixed the opinion is and thus susceptible to bias processing); (c) affective response (how emotive the topic is) and (d) risk perception (the extent the tool is perceived as detrimental to humans and nature).

Our study found no evidence of motivated reasoning or heightened emotional response to the counter‐aligned frames, suggesting gene drive remains a new topic to the public and entrenched opinion has not been established. While the scientifically framed article was regarded as the most objective and credible, it elicited the greatest perception of risk from the humanitarian group. While current support for gene drive is currently high amongst this group, long‐term exposure to scientifically framed messages may result in reduced support and polarisation. Communicating with this group using language that recognises the sanctity of all life and humaneness of gene drive may be more effective in facilitating an open dialogue over time.

Early and effective public engagement about gene drive should occur prior to entrenched public attitudes, which is the current context in New Zealand, and not wait for further technology development.

A free Plain Language Summary can be found within the Supporting Information of this article.
Antibacterial activities of centrifugally spun polyethylene oxide/silver composite nanofibers
Authors: Hasan Md Toukir , Gonzalez Ramiro , Chipara Mircea , Materon Luis , Parsons Jason , Alcoutlabi Mataz
Published: February 2021

Composite nanofibers were prepared successfully by centrifugal spinning of poly(ethylene oxide) aqueous solutions containing silver nanoparticles. The core focus of the present work is to carefully evaluate the antibacterial activity of poly(ethylene oxide)–Ag composite nanofibers in the presence of Escherichia coli (E. coli) and Bacillus cereus (B. cereus) bacteria. Centrifugally spun nanofibers were obtained from poly(ethylene oxide)–Ag precursor solutions with different Ag nanoparticle loadings. The process parameters such as the spinneret rotational speed, collector‐spinneret distance, and relative humidity were optimized to obtain fine fibers. The complex morphology and flexible structure of the poly(ethylene oxide)–Ag composite fibers were investigated by scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis, and Raman spectroscopy. The composite nanofibers have been proven as a strong antibacterial agent against E. coli and B. cereus due to their capacity to form superior inhibition zones. The efficiency of inhibiting bacteria by nanofibers was over 98%. The workability of the bacteria was impeded by the nanofibrous membrane as the Ag nanoparticles presented an effective chemical ability to dysfunction the bacterial structure at the nanoscale. These results demonstrate that the centrifugally spun poly(ethylene oxide)–Ag nanofibers are promising antibacterial agents for biomedical applications.
Generosity in dictator game and social value orientation predicted the type of costly punishment in ultimatum game
Authors: Li Jing , Cheng Nanhua , Hou Wenwen
Published: February 2021

The current study investigated two types of punishment (prosocial and proself punishment) in the ultimatum game (UG) and examined the impact of individuals' prosocial orientation on the costly punishment in the UG in a representative sample of Chinese undergraduate students (N = 344). The prosocial orientation was measured with individuals' performance in the dictator game (DG), social value orientation (SVO), and the personal norm of reciprocity. Prosocial and proself punishers were established with responses in advantage and disadvantage offers in the UG. Results showed that prosocial and proself punishers coexisted in the UG, and prosocial punishers were more likely to be prosocial in SVO and allocated more resources to the recipient in the DG than proself punishers, but differences in positive/negative reciprocity between prosocial and proself punishers were not found. Further regression analysis found that SVO type and generosity in the DG could predict the type of punishers in the UG, but not positive/negative reciprocity. These findings indicate that individuals rejecting unfair offers in the UG may be motivated by either prosocial motivation with strict fairness concern (prosocial punishment) or selfish motivation with maximizing self‐interest concern (proself punishment). Moreover, SVO type and generosity in the DG might be effective measures to discriminate prosocial and proself punishers in the UG.
Thermodynamic analysis of micelles formation of anionic surfactant SDS in the presence of aqueous and aqueous solution of ionic liquid 1‐butyl‐3‐methylimidazolium chloride
Authors: Kumar Harsh , Katal Arjuna
Published: February 2021

In this study, the experimental conductivity, fluorescence, and UV spectroscopy study have been done for aqueous solutions of sodium dodecyl sulfate (SDS) and in aqueous ionic liquid (IL) 1‐butyl‐3‐methylimidazolium chloride [C4mim][Cl] solutions at a temperature of 298.15 K. Experimental conductivity measurement has been done at different temperatures from 298.15 to 308.15 K. Moreover, the critical micelle concentrations (CMCs) of the mentioned systems were determined by different methods; furthermore, the CMC values have been utilized to originate the values of thermodynamical parameters of micellization like standard enthalpy of micellization (
), the standard free energy of micellization (
), and standard entropy of micellization (
). Fourier transform‐infrared (FT‐IR) spectra have been recorded to investigate the interactions and structural changes that occurred in the mixed system. Work has been discussed in terms of the effect of the aqueous IL solution on the micellization process of the SDS.
Access and benefit‐sharing DNA Componentry for plant synthetic biology: Bioparts expressed in plant chassis
Authors: Rourke Michelle
Published: February 2021

Societal Impact Statement

The “Parts Agenda” is an approach to synthetic biology that fragments genetic resources into functional bioparts to help design and build biological devices and systems. Access and benefit‐sharing (ABS), and the issue of how to regulate digital sequence information (DSI) within the current ABS regime, poses a problem for synthetic biology because it assumes fragmented and abstracted bioparts can be traced to their country of origin for the purposes of benefit‐sharing, and that contributions to information and knowledge can be quantified and appropriately valued. Any DSI regulatory solutions should account for genetic resource fragmentation and other complexities of modern scientific practice.

The inclusion of digital sequence information (DSI, including genetic sequence data) in the existing access and benefit‐sharing (ABS) regime will alter the practice of synthetic biology. The potential impediments could be magnified for the “Parts Agenda”: the approach to synthetic biology that fragments genetic resources into their smallest functional units to create standardized, interchangeable “bioparts”, the building blocks for assembling synthetic biological devices. These biological devices are themselves interchangeable and can be used to engineer higher order synthetic biological systems.

This article examines how the extension of ABS laws to include DSI could foreseeably apply to the creation and use of plant‐derived and other bioparts in engineered biological devices expressed in plant chassis.

The article demonstrates that ABS issues will be similar for all approaches to synthetic biology, but that the Parts Agenda is uniquely exposed to the potential regulatory burden of bilateral ABS transactions between users and providers of genetic resources.

The original vision for bioparts was one of openness and sharing, with access and use unencumbered by intellectual property. This article shows that open access to bioparts will not last long if DSI is enclosed within the current ABS regime, destabilizing the values of openness and sharing in synthetic biology that are ostensibly foundational to this still developing field.
Thermal Decomposition of Ammonium Perchlorate in the Presence of Copper Tungsten Oxide (CuWO4)
Authors: Jain Sunil , Varma Vijay K. , Mahajan Anil K. , Khire Vrushali H. , Kandasubramanian Balasubramanian
Published: February 2021

The catalytic effect of copper tungsten oxide (CuWO4) was investigated on the thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry. A lowering of the high‐temperature decomposition peak temperature of AP was observed due to catalytic effect of copper tungsten oxide particles, now referred to as CTO in this paper henceforth. The kinetic parameters were evaluated using the Kissinger method. The decrease in the activation energy confirmed the catalytic activity of CTO. Further, CTO was evaluated in a standard composite propellant formulation having 86 % solid loading. Propellant performance and processing parameters such as the end of mix (EOM) viscosity, density, burning rate, pressure exponent (n‐value), etc. were measured for standard as well as a composition containing 1 % CTO. The results revealed that at 1 % level CTO causes more than 36 % increase in propellant burning rate compared to the standard propellant composition at 6.86 MPa pressure. The pressure exponent also increased to 0.48, whereas the standard composition was having its value of 0.41.
Measuring migration motives with open‐ended survey data: Methodological and conceptual issues
Authors: Gillespie Brian Joseph , Mulder Clara H. , Eggleston Casey M.
Published: February 2021

Motives for migration are difficult to measure. Open‐ended data collection can be an attractive option, but also comes with pitfalls. We use the “Motives for Migration” survey on internal migration in Sweden to identify some of these pitfalls. We identify five categories of methodological issues: how the respondents—and we—dealt with multiple motives for migration; who the motive pertained to (i.e., the respondents themselves or someone else in the household); whether the motive was related to a status or an event; which third‐party person(s) the respondent meant to refer to; and which geographical unit the motive pertained to. We also identify two conceptual issues: (1) the distinction between reasons for moving and location choice and (2) the distinction between moving “from” and moving “to” somewhere. We present some suggestions that will be useful for future attempts to study the topic and possibly such other topics as motives for immigration, getting married, or leaving the parental home.
Structural Characterization of Oxyhalide Materials for Solid‐State Batteries
Authors: Fabian Margit , Tolnai Istvan , Khanna Atul , Horvath Zsolt Endre , Kovacs Kis Viktoria , Kovacs Zsolt
Published: February 2021

Development of materials with novel composition to obtain rechargeable solid‐state batteries with improved capacity and energy density is one of the hot topics in material science. Inorganic and thermally stable oxyhalide materials are potential substitutes for the toxic and flammable organic liquid electrolytes used in the Li‐ion batteries. Herein, Li‐, Na‐, and K‐ion‐based oxyhalide materials doped with Ca, Ba, and Mg are synthesized. The samples are characterized by neutron and X‐ray diffractometry, Raman spectroscopy, thermal analysis, and transmission electron microscopy (TEM). Significant differences can be observed between the Li/Na/K‐series, but within the series the diffraction character of the compositions is similar; semi‐amorphous/crystalline phases are identified. Characteristic first‐ and second‐neighbor distributions reveal a very compact network structure. X‐ray diffractometry and Raman studies prove that the investigated Li‐, Na‐, and K‐based samples absorb water, even if they are kept under dry conditions. The Li3OCl antiperovskite phase is identified by X‐ray diffraction (XRD) in all the Ca‐, Ba‐, and Mg‐doped samples. TEM studies show that the morphology of the samples consists of nanograins of different size below 100 nm. According to elemental maps, the doping Ba forms oxide nanoparticles, while Mg is incorporated into the Na‐ and K‐based network structure.
Objective Bayesian inference for the capability index of the Gamma distribution
Authors: de Almeida Marcello Henrique , Ramos Pedro Luiz , Rao Gadde Srinivasa , Moala Fernando Antonio
Published: February 2021

The Gamma distribution has been applied in research in several areas of knowledge, due to its good flexibility and adaptability nature. Process capacity indices like are widely used when the measurements related to the data follow a normal distribution. This article aims to estimate the index for nonnormal data using the Gamma distribution. We discuss maximum likelihood estimation and a Bayesian analysis through the Gamma distribution using an objective prior, known as a matching prior that can return Bayesian estimates with good properties for the . A comparative study is made between classical and Bayesian estimation. The proposed Bayesian approach is considered with the Markov chain Monte Carlo method to generate samples of the posterior distribution. A simulation study is carried out to verify whether the posterior distribution presents good results when compared with the classical approach in terms of the mean relative errors and the mean square errors, which are the two commonly used metrics to evaluate the parameter estimators. Based on the real dataset, Bayesian estimates and credibility intervals for unknown parameters and the prior distribution are achieved to verify if the process is under control.
Teaching sciences and mathematics – A challenge for higher education institutions: A systematic review
Authors: Vedrenne‐Gutiérrez Fernand , Altamirano‐Bustamante Myriam M. , Monroy‐Fraustro Daniela , de Hoyos Bermea Adalberto , Lopez‐Suero Carolina
Published: February 2021

The current job market requires scientifically literate human resources. At a time in which scientific reasoning should be part of the higher education curriculum, the general population is pulling away from it. This review aims to identify how students’ and teachers’ attitudes and values influence academic performance in science courses. PICO and the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) approaches were used to explore four databases and 6488 articles were retrieved. Articles had to be relevant to the research question and published within the last 10 years. Articles without an identifiable author or articles unrelated to the research question were excluded. Following three rounds of quality screening, 10 articles were finally selected for analysis. Study designs and quality varied across the selected articles. Self‐efficacy, having mastery goals, perceiving the course as valuable, and having a student identity were consistently associated with good learning outcomes. Cooperation was found to increase task value and autonomy when taking science courses; conversely, a performance approach and a consumer identity were negatively correlated with good learning outcomes. In the past 10 years, there was paucity in research studying the role of teacher attitudes towards science courses on learning outcomes. This article proposes a hypothetical model that describes how attitudes and values may lead to mastery and a good academic performance in undergraduate science courses. With this model, we seek to enhance and strengthen the nature and scope of science education in universities.
Output feedback control for quadratic systems: A Lyapunov function approach
Authors: Tognetti Eduardo S. , Jungers Marc , Calliero Taís R.
Published: February 2021

This article deals with the design of quadratic and linear dynamic output feedback controllers for quadratic systems to ensure, on the one hand, local exponential stability of the origin in the closed‐loop form and, on the other hand, to increase an estimate of the basin of attraction of the origin as large as possible. The introduction of a quadratic term in the controller allows us to consider a controller in the same class of dynamics as the studied system. Here, our approach is to consider a Lyapunov function with respect to the extended state gathering the states of the system and the controller. The induced nonlinear inequalities are treated thanks to an auxiliary vector repeating the extended state adequately and by combining distinct linearization techniques to finally obtain linear matrix inequalities. For comparison purposes, we also provide another approach characterizing the extended state as belonging to a polytope in the state space. Numerical examples illustrate the results.
Consistent decentralized cooperative localization for autonomous vehicles using LiDAR, GNSS, and HD maps
Authors: Héry Elwan , Xu Philippe , Bonnifait Philippe
Published: February 2021

To navigate autonomously, a vehicle must be able to localize itself with respect to its driving environment and the vehicles with which it interacts. This study presents a decentralized cooperative localization method. It is based on the exchange of local dynamic maps (LDM), which are cyber‐physical representations of the physical driving environment containing poses and kinematic information about nearby vehicles. An LDM acts as an abstraction layer that makes the cooperation framework sensor‐agnostic, and it can even improve the localization of a sensorless communicating vehicle. With this goal in mind, this study focuses on the property of consistency in LDM estimates. Uncertainty in the estimates needs to be properly modeled, so that the estimation error can be statistically bounded for a given confidence level. To obtain a consistent system, we first introduce a decentralized fusion framework that can cope with LDMs whose errors have an unknown degree of correlation. Second, we present a consistent method for estimating the relative pose between vehicles, using a two‐dimensional LiDAR (light detection and ranging) with a point‐to‐line metric within an iterative‐closest‐point approach, combined with communicated polygonal shape models. Finally, we add a bias estimator to reduce position errors when nondifferential GNSS (global navigation satellite system) receivers are used, based on visual observations of features geo‐referenced in a high‐definition map. Real experiments were conducted, and the consistency of our approach was demonstrated on a platooning scenario using two experimental vehicles. The full experimental data set used in this study is publicly available.
Visual diagnostics of an explainer model: Tools for the assessment of LIME explanations
Authors: Goode Katherine , Hofmann Heike
Published: February 2021

The importance of providing explanations for predictions made by black‐box models has led to the development of explainer model methods such as LIME (local interpretable model‐agnostic explanations). LIME uses a surrogate model to explain the relationship between predictor variables and predictions from a black‐box model in a local region around a prediction of interest. However, the quality of the resulting explanations relies on how well the explainer model captures the black‐box model in a specified local region. Here we introduce three visual diagnostics to assess the quality of LIME explanations: (1) explanation scatterplots, (2) assessment metric plots, and (3) feature heatmaps. We apply the visual diagnostics to a forensics bullet matching dataset to show examples where LIME explanations depend on the tuning parameter values and the explainer model oversimplifies the black‐box model. Our examples raise concerns about claims made of LIME that are similar to other criticisms in the literature.
Try these virtual orientation strategies to set students up for success
Authors: Pavlik Amelia
Published: February 2021

Nine weeks. That's how long Samantha Proffitt had to pull together an entirely online orientation in the spring and early summer of 2020.
Beat remote disconnect by creating virtual support groups
Authors: McCarthy Claudine
Published: February 2021

Effective student engagement in the age of Zoom and COVID‐19 often seems like an impossibility. But that hasn't stopped Brandi Hephner LaBanc, Ed.D., Vice Chancellor for Student Affairs and Campus Life at the University of Massachusetts Amherst.
A new disjunctive literal insertion fault detection strategy in boolean specifications
Authors: Paul T. K. , Chowdhury M. J. M. , Lau M. F.
Published: February 2021

In fault‐based Boolean expression testing, the main challenge is to generate effective test cases that can detect faults within expressions. Previous studies show that it is hard to detect literal insertion faults, more specifically Disjunctive literal insertion fault (LIF[+]) compared with other faults in Boolean expressions. Researchers have been using different strategies such as multiple near false point coverage (MNFP) and modified condition decision coverage (MCDC) to detect LIF[+] faults. However, these strategies have their own limitations. For example, MNFP can only be applied when the expression is in irredundant disjunctive normal form (IDNF), and MCDC detects a low percentage of LIF[+] faults. In this paper, we propose an abstract syntax tree (AST)‐based test case generation strategy for LIF[+] fault detection that overcomes these limitations. Furthermore, our experimental results indicate that, on average, the test suites satisfying the proposed strategy can detect approximately 97.3% of LIF[+] faults for general form expressions and 89.7% of LIF[+] faults for IDNF expressions, which are 15.6% and 13.8% improvement, respectively, compared to the MCDC test suites. Moreover, the size of the required test suite is smaller than that of MCDC test suite.
Theoretical Insight into High‐Efficiency Triple‐Junction Tandem Solar Cells via the Band Engineering of Antimony Chalcogenides
Authors: Cao Yu , Liu Chaoying , Jiang Jiahao , Zhu Xinyun , Zhou Jing , Ni Jian , Zhang Jianjun , Pang Jinbo , Rummeli Mark H. , Zhou Weijia , Liu Hong , Cuniberti Gianaurelio
Published: February 2021

Antimony chalcogenides have become a family of promising photoelectric materials for high‐efficiency solar cells. To date, single‐junction solar cells based on individual antimony selenide or sulfide are dominant and show limited photoelectric conversion efficiency. Therefore, great gaps remain for the multiple junction solar cells. Herein, triple‐junction antimony chalcogenides‐based solar cells are designed and optimized with a theoretical efficiency of 32.98% through band engineering strategies with Sb2S3/Sb2(S0.7Se0.3)3/Sb2Se3 stacking. The optimum Se content of the mid‐cell should be maintained low, i.e., 30% for achieving a low defect density in an absorber layer. Therefore, Sb2(S0.7Se0.3)3‐based mid solar cells have contributed to elevate the external quantum efficiency in triple‐junction devices by the full utilization of the solar spectrum. In a single‐junction solar cell, the bandgap gradient is regulated through the Se content gradient along the depth profile of Sb2(S1−xSex)3. Besides, an increasing Se content profile provides an additional built‐in electric field for boosting hole charge carrier collection. Thus, the high charge carrier generation rate leads to a 17.96% improvement in the conversion efficiency compared with a conventional cell. This work may pave the way to boost the conversion efficiency of antimony chalcogenides‐based solar cells to their theoretical limits.
Suppression of Defects Through Cation Substitution: A Strategic Approach to Improve the Performance of Kesterite Cu2ZnSn(S,Se)4 Solar Cells Under Indoor Light Conditions
Authors: Park Jongsung , Lee Minwoo , Karade Vijay , Shin So Jeong , Yoo Hyesun , Shim Hongjae , Gour Kuldeep Singh , Kim Dongmyung , Hwang Jiseon , Shin Donghyeop , Seidel Jan , Kim Jong H. , Yun Jaesung , Kim Jin Hyeok
Published: February 2021

Recent efficiency advancements in kesterites have reinforced the use of Cu2ZnSn(S,Se)4 (CZTSSe) in indoor photovoltaic applications. However, the performance of kesterites under low light intensity conditions is mainly hindered by deep‐level defects. In this study, a strategic approach of silver (Ag) and germanium (Ge) cation substitution to cure these defects are employed. The Ag‐doped CZTSSe (CZTSSe:Ag) and Ge‐doped (CZTSSe:Ge) samples experimentally demonstrated a significant improvement in kesterite device performance under all intensities of LED and white fluorescent lamp conditions are prepared. Interestingly, the CZTSSe:Ag device exhibited the highest performance levels, i.e., 1.2–1.5 and 2.5–3 times better than those of Ge‐doped CZTSSe:Ge and undoped CZTSSe, respectively. This improved device performance is mainly attributed to the reduced energy level of deep‐level defects in CZTSSe:Ag. Moreover, these defects assisted in the generation of a larger potential difference between the grain boundary and grain interior in the CZTSSe:Ag sample, attracting minority carriers near the grain boundary. Consequently, the improved carrier separation process reduced the carrier recombination losses and enhanced the power output under low light intensity conditions. This Ag and Ge cation substitution in kesterite is found to be an effective approach to improve the device performance under low light intensity conditions.
Evolution of Microporosities in Wide‐Thick Continuous Casting Slab during Heavy Reduction Process
Authors: Zhang Jinyuan , Wu Chenhui , Ji Cheng , Chen Yi , Zhu Miaoyong
Published: February 2021

Heavy reduction (HR) is an effective process that can significantly minimize the internal porosity and other internal defects in continuous casting steel. Herein, samples taken from different wide‐thick slab positions are examined by scanning acoustic microscopy and 3D reconstructed. The morphology and distribution of microporosities <1 mm in size in the wide‐thick slab are revealed. The microporosities are mainly distributed in a stripping zone symmetric about the centerline within a 1/3‐slab thickness, and most have a considerably obvious long‐ and short‐axis tendency, which can be approximated as ellipsoids. The microporosity evolution in the wide‐thick slab during HR at the solidification end is numerically investigated with a 3D thermal–mechanical coupled model. The microporosity evolution in an aggregated distribution region during HR is little influenced by the surrounding microporosities. With increasing slab centerline‐microporosity distance, the microporosity minimization effect of HR becomes poor. When the axial ratio (long axis/short axis) is 1.43, the microporosity closure is the largest, and the porosity closure is the highest when the long axis is perpendicular to the reduction direction. When the total segment reduction is constant, the reduction mode with gradually decreasing reduction results in the highest total porosity closure and minimum reduction force.
Analysis of the primary sources of quantitative adult plant resistance to stripe rust in U.S. soft red winter wheat germplasm
Authors: Ward Brian P. , Merrill Keith , Bulli Peter , Pumphrey Mike , Mason Richard Esten , Mergoum Mohamed , Johnson Jerry , Sapkota Suraj , Lopez Benjamin , Marshall David , Brown‐Guedira Gina
Published: February 2021

Stripe rust, or yellow rust (Puccinia striiformis Westend. f. sp. tritic), is a disease of wheat (Triticum aestivum L.) historically causing significant economic losses in cooler growing regions. Novel isolates of stripe rust with increased tolerance for high temperatures were detected in the United States circa 2000. This increased heat tolerance puts geographic regions, such as the soft red winter wheat (SRWW) growing region of the southeastern United States, at greater risk of stripe rust induced losses. In order to identify sources of stripe rust resistance in contemporary germplasm, we conducted genome‐wide association (GWA) studies on stripe rust severity measured in two panels. The first consisted of 273 older varieties, landraces, and some modern elite breeding lines and was evaluated in environments in the U.S. Pacific Northwest and the southeastern United States. The second panel consisted of 588 modern, elite SRWW breeding lines and was evaluated in four environments in Arkansas and Georgia. The analyses identified three major resistance loci on chromosomes: 2AS (presumably the 2NS:2AS alien introgression from Aegilops ventricosa Tausch; syn. Ae. caudata L.), 3BS, and 4BL. The 4BL locus explained a greater portion of variance in resistance than either the 2AS or 3BS loci in southeastern environments. However, its effects were unstable across different environments and sets of germplasm, possibly a result of its involvement in epistatic interactions. Relatively few lines carry resistance alleles at all three loci, suggesting that there is a pre‐existing reservoir of enhanced stripe rust resistance that may be further exploited by regional breeding programs.