bluuebunny/crossref_metadata_2025 huggingface dataset:
Extended Physics-Based Reduced-Order Capacity Fade Model for Lithium-Ion Battery Cells1
Authors: Salyer Zachary , D’Arpino Matilde , Canova Marcello
Published: February 2021

Aging models are necessary to accurately predict the state of health (SOH) evolution in lithium-ion battery systems when performing durability studies under realistic operations, specifically considering time-varying storage, cycling, and environmental conditions, while being computationally efficient. This article extends existing physics-based reduced-order capacity fade models that predict degradation resulting from the solid electrolyte interface (SEI) layer growth and loss of active material (LAM) in the graphite anode. Specifically, the physics of the degradation mechanisms and aging campaigns for various cell chemistries are reviewed to improve the model fidelity. In addition, a new calibration procedure is established relying solely on capacity fade data and results are presented including extrapolation/validation for multiple chemistries. Finally, a condition is integrated to predict the onset of lithium plating. This allows the complete cell model to predict the incremental degradation under various operating conditions, including fast charging.
Barriers to Physical Activity Among Emergency Medical Services Professionals
Authors: Supples Michael W. , Rivard Madison K. , Cash Rebecca E. , Chrzan Kirsten , Panchal Ashish R. , McGinnis Henderson D.
Published: February 2021

Background: Emergency medical services (EMS) professionals demonstrate low adherence to physical activity guidelines and experience a high prevalence of obesity and incidence of injury. The authors investigate the barriers to participating in physical activity among EMS professionals. Methods: The EMS professionals employed by 15 North Carolina EMS agencies were surveyed with validated items. Multivariable logistic regression models were used to estimate the odds (odds ratio, 95% confidence interval) of not meeting physical activity guidelines for each barrier to being active, controlling for age, sex, body mass index category, race/ethnicity, certification and education level, and work hours. Results: A total of 1367 EMS professionals were invited to participate, and 359 complete responses were recorded. Half of the respondents (48.2%) met Centers for Disease Control and Prevention physical activity guidelines. According to standard body mass index categories, 55.9% were obese. There were increased odds of not meeting physical activity guidelines for the following barriers: lack of energy (5.32, 3.12–9.09), lack of willpower (4.31, 2.57–7.22), lack of time (3.55, 2.12–5.94), social influence (3.02, 1.66–5.48), and lack of resources (2.14, 1.12–4.11). The barriers of fear of injury and lack of skill were not associated with meeting physical activity guidelines. Conclusion: Half of EMS professionals did not meet physical activity guidelines, and the majority were obese. Significant associations exist between several modifiable barriers and not meeting physical activity guidelines.
Gesturing Elsewhere and Offshore Memory: Amateur Elite Soccer in the Fiji Islands, 1980–1992
Authors: James Kieran , Nadan Yogesh
Published: February 2021

This article studies the amateur elite National Soccer League in the Fiji Islands from 1980 to 1992 and the Fiji national team's landmark 1–0 win over Australia in 1988. The authors use the theoretical idea of “gesturing elsewhere,” taken from the work of popular music scholar Emma Baulch, to explain how the local Fiji soccer community receives its meaning and identity largely as the local-outpost or chapter of the global soccer scene. Therefore, a victory over the sporting powerhouse Australia boosts the self-image of the Fiji soccer world by temporarily upturning the established hierarchies. The shock 1988 win saw Fiji assigned extra credibility in the global context. The authors also look at the Indo-Fijian (Fijians of Indian decent) emigrant communities of the West and argue that, through their ongoing love of Fiji soccer, they play a role akin to offshore memory or offshore library, cataloging past history and revering past stars and classic contests.
A methylotrophic origin of methanogenesis and early divergence of anaerobic multicarbon alkane metabolism
Authors: Wang Yinzhao , Wegener Gunter , Williams Tom A. , Xie Ruize , Hou Jialin , Wang Fengping , Xiao Xiang
Published: February 2021

Phylogenomic analyses reveal the origin and evolution of anaerobic alkane metabolism in the domain of Archaea.
First record of the sound produced by the oldest Upper Paleolithic seashell horn
Authors: Fritz C. , Tosello G. , Fleury G. , Kasarhérou E. , Walter Ph. , Duranthon F. , Gaillard P. , Tardieu J.
Published: February 2021

A prehistoric conch shell converted into a musical instrument makes its first sounds in 18,000 years.
Complete Genome Sequences of Two Type 3 Porcine Circoviruses, WB17KW and WB20GG, Isolated from Korean Wild Boar
Authors: Song Sok , Park Kyu-Nam , Choe SeEun , Cha Ra Mi , Shin Jihye , Hyun Bang-Hun , An Dong-Jun
Published: February 2021

Porcine circovirus type 3 (PCV3) in domestic pigs was first reported in South Korea in 2017. Here, we report the first complete genome sequences of two PCV3 strains isolated from Korean wild boar, which enhance our understanding about the genetic relatedness of PCV3 in domestic pigs and wild boar.
Complete Genome Sequence of Burkholderia cenocepacia Phage Mica
Authors: Garcia James , Yao Guichun , Vizoso-Pinto Maria Guadalupe , Clark James , Le Tram , Gonzalez Carlos , Gill Jason , Liu Mei
Published: February 2021

Burkholderia cenocepacia
is a multidrug-resistant Gram-negative pathogen known to colonize patients with chronic granulomatous disease and cystic fibrosis. Here, we describe
Burkholderia
phage Mica, which is predicted to be a lysogenic myophage based on the similarity of its structural proteins to
Enterobacteria
phage P2 and
Burkholderia
phage KL3.
Non-ST elevation myocardial infarction (NSTEMI) and complex coronary artery fistula in a fit 57-year-old man and its management
Authors: Malik Muhamamd Isfandyar Khan
Published: February 2021

A fit 57-year-old man presented with exertional chest pain to the emergency department and was found to have anterolateral T wave inversion on ECG and blood troponin of 1290. Coronary angiography showed a severe proximal to mid-course lesion in mid left anterior descending (LAD) artery, severe ostial disease in obtuse marginal 1 (OM1) and large coronary artery fistula between proximal LAD and main pulmonary artery (PA). Subsequent cardiac CT multiple gated acquisition scan showed a coronary artery to main PA fistula, fed by small branches of the LAD and right coronary artery (RCA). Cardiac magnetic resonance (CMR) showed preserved left ventricle systolic function, ejection fraction 62% and small left to right shunt. Following multidisciplinary team (MDT) discussion, the patient was offered coronary artery bypass grafting (CABG) and fistula ligation as first option, but percutaneous intervention (PCI) to the LAD would also be feasible. After lengthy discussions the patient declined CABG and opted for PCI and stent insertion.
Detecting non-alcoholic fatty liver disease and risk factors in health databases: accuracy and limitations of the ICD-10-AM
Authors: Hayward Kelly Lee , Johnson Amy L , Horsfall Leigh U , Moser Chris , Valery Patricia C , Powell Elizabeth E
Published: February 2021

Objective

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) cirrhosis is often underestimated in healthcare and administrative databases that define disease burden using International Classification of Diseases (ICD) codes. This retrospective audit was conducted to explore the accuracy and limitations of the ICD, Tenth Revision, Australian Modification (ICD-10-AM) to detect NAFLD, metabolic risk factors (obesity and diabetes) and other aetiologies of chronic liver disease.

Design/Method

ICD-10-AM codes in 308 admitted patient encounters at two major Australian tertiary hospitals were compared with data abstracted from patients’ electronic medical records. Accuracy of individual codes and grouped combinations was determined by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Cohen’s kappa coefficient (κ).

Results

The presence of an ICD-10-AM code accurately predicted the presence of NAFLD/NASH (PPV 91.2%) and obesity (PPV 91.6%) in most instances. However, codes underestimated the prevalence of NAFLD/NASH and obesity by 42.9% and 45.3%, respectively. Overall concordance between clinical documentation and ‘grouped alcohol’ codes (κ 0.75) and hepatitis C codes (κ 0.88) was high. Hepatitis B codes detected false-positive cases in patients with previous exposure (PPV 55.6%). Accuracy of codes to detect diabetes was excellent (sensitivity 95.8%; specificity 97.6%; PPV 94.9%; NPV 98.1%) with almost perfect concordance between codes and documentation in medical records (κ 0.93).

Conclusion

Recognition of the utility and limitations of ICD-10-AM codes to study the burden of NAFLD/NASH cirrhosis is imperative to inform public health strategies and appropriate investment of resources to manage this burgeoning chronic disease.
Predicting mortality in adults with suspected infection in a Rwandan hospital: an evaluation of the adapted MEWS, qSOFA and UVA scores
Authors: Klinger Amanda , Mueller Ariel , Sutherland Tori , Mpirimbanyi Christophe , Nziyomaze Elie , Niyomugabo Jean-Paul , Niyonsenga Zack , Rickard Jennifer , Talmor Daniel S , Riviello Elisabeth
Published: February 2021

Rationale

Mortality prediction scores are increasingly being evaluated in low and middle income countries (LMICs) for research comparisons, quality improvement and clinical decision-making. The modified early warning score (MEWS), quick Sequential (Sepsis-Related) Organ Failure Assessment (qSOFA), and Universal Vital Assessment (UVA) score use variables that are feasible to obtain, and have demonstrated potential to predict mortality in LMIC cohorts.

Objective

To determine the predictive capacity of adapted MEWS, qSOFA and UVA in a Rwandan hospital.

Design, setting, participants and outcome measures

We prospectively collected data on all adult patients admitted to a tertiary hospital in Rwanda with suspected infection over 7 months. We calculated an adapted MEWS, qSOFA and UVA score for each participant. The predictive capacity of each score was assessed including sensitivity, specificity, positive and negative predictive value, OR, area under the receiver operating curve (AUROC) and performance by underlying risk quartile.

Results

We screened 19 178 patient days, and enrolled 647 unique patients. Median age was 35 years, and in-hospital mortality was 18.1%. The proportion of data missing for each variable ranged from 0% to 11.7%. The sensitivities and specificities of the scores were: adapted MEWS >4, 50.4% and 74.9%, respectively; qSOFA >2, 24.8% and 90.4%, respectively; and UVA >4, 28.2% and 91.1%, respectively. The scores as continuous variables demonstrated the following AUROCs: adapted MEWS 0.69 (95% CI 0.64 to 0.74), qSOFA 0.65 (95% CI 0.60 to 0.70), and UVA 0.71 (95% CI 0.66 to 0.76); there was no statistically significant difference between the discriminative capacities of the scores.

Conclusion

Three scores demonstrated a modest ability to predict mortality in a prospective study of inpatients with suspected infection at a Rwandan tertiary hospital. Careful consideration must be given to their adequacy before using them in research comparisons, quality improvement or clinical decision-making.
Who will benefit from bariatric surgery for diabetes? A protocol for an observational cohort study
Authors: Kenkre Julia S , Ahmed Ahmed R , Purkayastha Sanjay , Malallah Khalefah , Bloom Stephen , Blakemore Alexandra I , Prevost A Toby , Tan Tricia
Published: February 2021

Introduction

Type 2 diabetes mellitus (T2DM) and obesity are pandemic diseases that lead to a great deal of morbidity and mortality. The most effective treatment for obesity and T2DM is bariatric or metabolic surgery; it can lead to long-term diabetes remission with 4 in 10 of those undergoing surgery having normal blood glucose on no medication 1 year postoperatively. However, surgery carries risks and, additionally, due to resource limitations, there is a restricted number of patients who can access this treatment. Moreover, not all those who undertake surgery respond equally well metabolically. The objective of the current research is to prospectively investigate predictors of T2DM response following metabolic surgery, including those directly involved in its aetiopathogenesis such as fat distribution and genetic variants. This will inform development of a clinically applicable model to help prioritise this therapy to those predicted to have remission.

Methods and analysis

A prospective multicentre observational cohort study of adult patients with T2DM and obesity undergoing Roux-en-Y gastric bypass surgery. Patients will be comprehensively assessed before surgery to determine their clinical, metabolic, psychological, genetic and fat distribution profiles. A multivariate logistic regression model will be used to assess the value of the factors derived from the preoperative assessment in terms of prediction of diabetes remission.

Ethics and dissemination

Formal ethics review was undertaken with a favourable opinion (UK HRA RES reference number 18/LO/0931). The dissemination plan is to present the results at conferences, in peer-reviewed journals as well as to lay media and to patient organisations.

Trial registration details

ClinicalTrials.gov, Identifier:NCT03842475.
Diurnal variations in the expression of core-clock genes correlate with resting muscle properties and predict fluctuations in exercise performance across the day
Authors: Basti Alireza , Yalçin Müge , Herms David , Hesse Janina , Aboumanify Ouda , Li Yin , Aretz Zita , Garmshausen Josefin , El-Athman Rukeia , Hastermann Maria , Blottner Dieter , Relógio Angela
Published: February 2021

Objectives

In this study, we investigated daily fluctuations in molecular (gene expression) and physiological (biomechanical muscle properties) features in human peripheral cells and their correlation with exercise performance.

Methods

21 healthy participants (13 men and 8 women) took part in three test series: for the molecular analysis, 15 participants provided hair, blood or saliva time-course sampling for the rhythmicity analysis of core-clock gene expression via RT-PCR. For the exercise tests, 16 participants conducted strength and endurance exercises at different times of the day (9h, 12h, 15h and 18h). Myotonometry was carried out using a digital palpation device (MyotonPRO), five muscles were measured in 11 participants. A computational analysis was performed to relate core-clock gene expression, resting muscle tone and exercise performance.

Results

Core-clock genes show daily fluctuations in expression in all biological samples tested for all participants. Exercise performance peaks in the late afternoon (15–18 hours for both men and women) and shows variations in performance, depending on the type of exercise (eg, strength vs endurance). Muscle tone varies across the day and higher muscle tone correlates with better performance. Molecular daily profiles correlate with daily variation in exercise performance.

Conclusion

Training programmes can profit from these findings to increase efficiency and fine-tune timing of training sessions based on the individual molecular data. Our results can benefit both professional athletes, where a fraction of seconds may allow for a gold medal, and rehabilitation in clinical settings to increase therapy efficacy and reduce recovery times.
Role of health simulation centres in the COVID-19 pandemic response in Italy: a national study
Authors: Ingrassia Pier Luigi , Ferrari Mattia , Paganini Matteo , Mormando Giulia
Published: February 2021

Introduction

The COVID-19 pandemic has dramatically affected the Italian health systems and drastically impacted healthcare workers’ daily routine and training. Simulation is an efficient tool to provide medical education, especially in the case of incoming public health emergencies. This study investigated the role and activities of Italian simulation centres (SCs) during the acute phase of the COVID-19 pandemic.

Methods

The population was identified through a web search. The directors of Italian SCs were contacted via email and then enrolled. A structured interview was created, internally validated and administrated by phone to participants.

Results

Following the government’s ordinance, 37 (88.37%) SCs had to be closed to the public. Twenty (46.51%) SCs organised in situ simulation while 7 (16.28%) of them organised simulation inside the centre. Twenty-three (53.49%) SCs resorted to telematic modalities to provide training about COVID-19 and 21 (48.84%) of them for other training. Up to date, 13 SCs are still closed to the public.

Conclusions

Italy has been severely hit by COVID-19, with differences between the regions. Almost all the SCs were closed, with only a few delivering training. The SCs took advantage of emergent technologies to create new ways to train people safely. Unfortunately, nearly one-fourth of Italian SCs have not reopened yet. The evolution of the COVID-19 epidemic calls for reconsideration about training activities including adequate safety measures implemented for all individuals involved.
MINOCA: a heterogenous group of conditions associated with myocardial damage
Authors: Singh Trisha , Chapman Andrew R , Dweck Marc R , Mills Nicholas L , Newby David E
Published: February 2021

Myocardial infarction with non-obstructive coronary arteries (MINOCA) was first described over 80 years ago. The term has been widely and inconsistently used in clinical practice, influencing various aspects of disease classification, investigation and management. MINOCA encompasses a heterogenous group of conditions that include both atherosclerotic and non-atherosclerotic disease resulting in myocardial damage that is not due to obstructive coronary artery disease. In many ways, it is a term that describes a moment in the diagnostic pathway of the patient and is arguably not a diagnosis. Central to the definition is also the distinction between myocardial infarction and injury. The universal definition of myocardial infarction distinguishes acute myocardial infarction, including those with MINOCA, from other causes of myocardial injury by the presence of clinical evidence of ischaemia. However, these ischaemic features are often non-specific causing diagnostic confusion, and can create difficulties for patient management and follow-up. The purpose of this review is to summarise our current understanding of MINOCA and highlight important issues relating to the diagnosis, investigation and management of patients with MINOCA.
Success and failure of additional immune modulators in steroid-refractory/resistant pneumonitis related to immune checkpoint blockade
Authors: Beattie Jason , Rizvi Hira , Fuentes Paige , Luo Jia , Schoenfeld Adam , Lin I-Hsin , Postow Michael , Callahan Margaret , Voss Martin H , Shah Neil J , Betof Warner Allison , Chawla Mohit , Hellmann Matthew D
Published: February 2021

Background

Pneumonitis related to immune checkpoint blockade is uncommon but can be severe, fatal or chronic. Steroids are first-line treatment, however, some patients are refractory or become resistant to steroids. Like many immune-related adverse events, little is known regarding the outcomes and optimal management of patients in whom steroids are ineffective.

Methods

We performed a single-center retrospective cohort study at a high-volume tertiary cancer center to evaluate the clinical course, management strategies and outcomes of patients treated for immune checkpoint pneumonitis with immune modulatory medications in addition to systemic steroids. Pharmacy records were queried for patients treated with both immune checkpoint blockade and receipt of additional immune modulators. Records were then manually reviewed to identify patients who received the additional immune modulators for immune checkpoint pneumonitis.

Results

From 2013 to 2020, we identified 26 patients treated for immune checkpoint pneumonitis with additional immune modulators in addition to steroids. Twelve patients (46%) were steroid-refractory and 14 (54%) were steroid-resistant. Pneumonitis severity included grade 2 (42%) or grade 3–4 (58%). Additional immune modulation consisted of tumor necrosis factor-alpha inhibitor (77%) and/or mycophenolate (23%). Durable improvement in pneumonitis following initiation of additional immune modulators occurred in 10 patients (38%), including three patients (12%) in whom pneumonitis resolved and all immunosuppressants ceased. The rate of 90-day all-cause mortality/hospice referral was 50%. At last follow-up, mortality attributable to pneumonitis was 23%. In addition to mortality from pneumonitis and cancer, 3 patients (12%) died due to infections possibly associated with immunosuppression.

Conclusions

Steroid-refractory or -resistant immune checkpoint pneumonitis is uncommon but associated with significant morbidity and mortality. Additional immunomodulators can yield durable improvement, attained in over one third of patients. An improved understanding of the underlying biology of immune-related pneumonitis will be crucial to guide more precise and effective treatment strategies in the future.
Lithobiotopes of the Nemegt Gobi Basin1
Authors: Jerzykiewicz Tomasz , Currie Philip J. , Fanti Federico , Lefeld Jerzy
Published: February 2021

Three distinct but overlapping dinosaur-dominated faunas characterize the Upper Cretaceous Djadokhta, Baruungoyot, and Nemegt formations of the Nemegt Basin of Mongolia. Documented faunal differences cannot be explained easily by temporal succession, but can be understood in light of the physical processes controlling the life, death, and burial of taxa. The stratigraphy of the Gobi Desert region records tectonically driven geometries, clearly documenting preservational processes that differ from those acting in most other dinosaur-dominated beds worldwide. Small, asymmetric tectonic grabens were filled with Upper Cretaceous dinosaur-bearing deposits showing asymmetric distributions of facies, here termed lithobiotopes. The water-lain fluvial and alluvial plain facies of the Nemegt lithobiotope supported and preserved a fauna dominated by gigantic dinosaurs, but had a preservational bias against smaller animals. The Nemegt passed laterally into the interdune facies of the Baruungoyot lithobiotope, which represented a hostile environment for large species, but preserved smaller animals. This in turn passed laterally into the aeolianite facies of the Djadokhta lithobiotope, which is characterized by the remains of small dinosaurs and a rich fauna of other animals. The Nemegt Gobi Basin can be visualized as an oasis with a central pond supplied with water from ephemeral channels and surrounded by a semi-arid alluvial plain and dune fields.
A financial analysis of four carbon offset accounting protocols for a representative afforestation project (southern Ontario, Canada)
Authors: Hope Emily S. , Filewod Ben , McKenney Daniel W. , Lemprière Tony C.
Published: February 2021

Forestry projects participate in carbon markets by sequestering carbon dioxide equivalent (CO2e) and producing carbon offsets. The creation of forest-based offsets is guided by protocols that dictate how sequestered CO2e is converted into marketable offsets. Existing protocol designs aim to produce offsets that meet sustainability requirements, while providing financial incentives for landowner participation. However, limited Canadian uptake implies that current financial incentives are insufficient to encourage the production of carbon offsets via private landowners. Here we consider various design features of four protocols and their financial implications for an illustrative afforestation project in southern Ontario, Canada. We explore the protocols (two tonne–tonne protocols and two tonne–year protocols) under two afforestation project management systems (“no-harvest” and “harvest” management scenarios). Results indicate that a project that terminates in a harvest is not economically attractive at current CO2e prices under any protocol design at a scale likely to be undertaken in southern Ontario, Canada. Projects that do not conclude in harvest are generally more attractive. Tonne–tonne protocols that pay upfront for sequestered CO2e improve the economic attractiveness of afforestation projects, but the delayed realization of the value of offset credits under tonne–year protocols reduces the economic attractiveness of these projects. We discuss these results in light of the choices facing afforestation project proponents and offset protocol designers (including governments) in general, and provide detailed insights into the financial dynamics of the Canadian case.
Evidence of morphological adaptation to life underwater: sternal keel affects swimming speed in giant water scavenger beetles (Coleoptera: Hydrophilidae: Hydrophilini)
Authors: Matsushima Ryosuke
Published: February 2021

Fundamentally, insects evolved on land and secondarily inhabited aquatic environments multiple times. To live underwater, aquatic insects have acquired enormously variable morphological, developmental, physiological, and ecological traits, such as gas exchange systems and swimming-related characteristics. Giant water scavenger beetles of the tribe Hydrophilini (Coleoptera: Hydrophilidae) are characterized by the presence of a sternal keel, which often extends posteriorly. Despite being a conspicuous morphological trait, its function remains unclear. Here, I verified two hypotheses: keel affects (1) submergence time following air replacement and (2) speed and oscillatory movement during forward swimming in Hydrophilus acuminatus Motschulsky, 1854. Submergence time was affected by body mass rather than keel removal; in other words, larger individuals replaced their gas gills more frequently. Keel removal reduced swimming speed by 12.5%. These observations support the second hypothesis, and are also consistent with previous speculations that the sternal keel is a key adaptation for swimming, but the results showed that the degree of oscillation was closely related to body mass but not to keel removal. Further studies are warranted to elucidate precise factors through which the presence of the keel increases swimming speed. Such studies would provide clues into understanding the associations among body size, swimming methods, and morphological traits.
First observation of ion beam channeling in bent crystals at multi-TeV energies
Authors: Redaelli S. , Butcher M. , Barreto C. , Losito R. , Masi A. , Mirarchi D. , Montesano S. , Rossi R. , Scandale W. , Serrano Galvez P. , Valentino G. , Galluccio F.
Published: February 2021

Planar channeling in bent crystals has been observed in LHC with multi-TeV proton beam in 2015. Two crystals, mounted on novel high-accuracy goniometers (one in the horizontal and one in the vertical plane), are integrated in the LHC collimation system, for studying the feasibility of the crystal-based collimation scheme. Using this experimental setup, tests with fully-stripped lead ion beams at both 450 Z and 6500 Z GeV were carried during dedicated LHC beam time. Planar channeling was observed for the first time with lead ions at these unprecedented energies surpassing by more than 1 order of magnitude the previous state-of-the-art for lead heavy ions and providing an important experimental basis for future applications of bent crystals in beam manipulations. The set of measurements performed to confirm this observation, as the local loss reduction in presence of channeling and the evidence of a deflected beam downstream of the crystal, are presented.
Erratum to: Distortions of Robertson–Walker metric in perturbative cosmology and interpretation as dark matter and cosmological constant
Authors: Re Federico
Published: February 2021

This erratum concerns the corrections of Equation (41) and Equation (44), that should read:
Dominant superconducting pairing symmetry in doped staggered-flux Hubbard model on a square lattice
Authors: Yu Zhuoya , Wang Jiabao , Tian Lingyu , Chen Qiaoni , Liang Ying , Ma Tianxing
Published: February 2021

A constrained path quantum Monte Carlo simulation is performed to investigate the superconducting pairing correlation in doped staggered-flux Hubbard model on a square lattice, which is an interesting platform to host Dirac fermions. For various electron fillings and interaction strengths, the [Formula: see text] pairing dominates over other pairing forms since its long-range correlation is larger over mostly distances. We deepen our study by including the nearest-neighbor interaction [Formula: see text] and found the [Formula: see text] pairing correlation is slightly suppressed by increasing [Formula: see text].
Irreducible first Brillouin zone for two-dimensional magnonic crystals with asymmetric complex lattices
Authors: Yang Hui , Yun Guo-Hong , Cao Yong-Jun
Published: February 2021

Two-dimensional (2D) magnonic crystal (MC) with an asymmetric complex basis is proposed in this paper, and its band structures are calculated in the whole area of the first Brillouin zone (BZ). This kind of MCs is composed of two different atoms in the unit cell, and the symmetry of the unit cell is broken due to changes in the position of the second atom, so the irreducible part of the BZ is no longer the small area [Formula: see text] for square lattice, and it must be expanded to the whole first BZ. Only by investigating the whole first BZ, can we get the true full band-gap for this kind of MCs.
Probabilistic model of structural phase transition in perovskites
Authors: Jabarov S. H. , Aliyev R. T. , Ismayilova N. A.
Published: February 2021

In this work, the crystal structures and phase transitions of compounds with perovskite structure were investigated. The classification of structural phase transitions in perovskites was carried out, the most common crystal structures and structural phase transitions were shown. A mathematical model was constructed, a theorem was given and proved for the probability of a possible transition. The formulas [Formula: see text] and [Formula: see text] are given for the mathematical expectation and variance of random variable [Formula: see text], which is the moment when the stochastic process [Formula: see text] deviation from the boundary [0, [Formula: see text]] interval for the first time. According to the mathematical model, one of the trajectories of random processes corresponding to the phase transitions that occur in perovskites is constructed.
Realization of Generalized Current-Mode Multifunction Filter
Authors: Jitender  , Mohan Jitendra , Chaturvedi Bhartendu
Published: February 2021

In this work, a three-input single-output structure of current-mode second-order multifunction filter is presented. Two multiple-output second-generation current conveyors serve as the active building blocks. Additionally, two grounded resistors and two grounded capacitors are employed as passive components. On appropriate selection of the input values, all second-order filter functionalities, namely, low-pass, high-pass, all-pass, band-pass and band-reject, can be availed. Proposed filter shows good sensitivity performance and supports high frequency operation. Non-ideal analysis is presented to show the intactness of filter characteristics under runtime conditions. Simulation results show good correlation with the theoretical performance of the proposed filter.
Adaptive non-hierarchical Galerkin methods for parabolic problems with application to moving mesh and virtual element methods
Authors: Cangiani Andrea , Georgoulis Emmanuil H. , Sutton Oliver J.
Published: February 2021

We present a posteriori error estimates for inconsistent and non-hierarchical Galerkin methods for linear parabolic problems, allowing them to be used in conjunction with very general mesh modification for the first time. We treat schemes which are non-hierarchical in the sense that the spatial Galerkin spaces between time-steps may be completely unrelated from one another. The practical interest of this setting is demonstrated by applying our results to finite element methods on moving meshes and using the estimators to drive an adaptive algorithm based on a virtual element method on a mesh of arbitrary polygons. The a posteriori error estimates, for the error measured in the [Formula: see text] and [Formula: see text] norms, are derived using the elliptic reconstruction technique in an abstract framework designed to precisely encapsulate our notion of inconsistency and non-hierarchicality and requiring no particular compatibility between the computational meshes used on consecutive time-steps, thereby significantly relaxing this basic assumption underlying previous estimates.
New results about the canonical transformation for boson operators
Authors: Raduta C. M. , Raduta A. A.
Published: February 2021

The Bogoliubov transformation for a monopole boson induces a unitary transformation connecting the Fock spaces of initial and correlated bosons. Here, we provide a very simple method for deriving the analytical expression for the overlap matrix of the basis states generating the two boson spaces.
Moduli spaces for Lamé functions and Abelian differentials of the second kind
Authors: Eremenko Alexandre , Gabrielov Andrei , Mondello Gabriele , Panov Dmitri
Published: February 2021

The topology of the moduli space for Lamé functions of degree [Formula: see text] is determined: this is a Riemann surface which consists of two connected components when [Formula: see text]; we find the Euler characteristics and genera of these components. As a corollary we prove a conjecture of Maier on degrees of Cohn’s polynomials. These results are obtained with the help of a geometric description of these Riemann surfaces, as quotients of the moduli spaces for certain singular flat triangles. An application is given to the study of metrics of constant positive curvature with one conic singularity with the angle [Formula: see text] on a torus. We show that the degeneration locus of such metrics is a union of smooth analytic curves and we enumerate these curves.
A Computationally Efficient Method for Optimum Tuning of Single-Sided Pounding Tuned Mass Dampers for Structural Vibration Control
Authors: Erdogan Yildirim Serhat , Ada Mehmet
Published: February 2021

Pounding tuned mass dampers (PTMD), which relies on impact to dissipate vibration energy, have shown remarkable performance in suppressing structural vibrations with its modest design. However, the optimum design of PTMDs is computationally expensive due to non-smooth contact-impact behavior. This study provides a computationally efficient approach to determine the optimal parameters of single-sided PTMDs used in vibration control of structural systems. An optimization strategy is used to minimize the maximum response of the controlled structure. As is well-known, the calculation of the dynamic response of a structure could be cumbersome when conventional time-stepping techniques are used in each iteration of the optimization routine. Hence, an exact analytical solution of the steady-state vibration is used to calculate the response for different excitation frequencies, which substantially decreases the computational burden. The adopted method is computationally very inexpensive with respect to the conventional time-stepping techniques used to solve the nonlinear equations of motion to obtain response quantities. The exact solution only requires the solution of the system of five nonlinear equations in order to evaluate the steady-state response per each excitation frequency of harmonic force. A four-storey shear building is used to evaluate the optimally-tuned PTMD by the proposed procedure. In addition, simplified design equations for the coefficient of restitution and frequency ratio are provided using curve and surface fitting for preliminary design. It was shown that the effect of damping ratio of the primary structure on the optimal coefficient of restitution value is not considerable, while it has significant influence on the optimal frequency ratio. It was also realized that the objective function used in optimum parameter design has only one local optimum, which is suitable for the application of gradient-based optimization methods.
On the universal envelope of a Jordan triple system of n × n matrices
Authors: Elgendy Hader A.
Published: February 2021

We study the universal (associative) envelope of the Jordan triple system of all [Formula: see text] [Formula: see text] matrices with the triple product [Formula: see text] over a field of characteristic 0. We use the theory of non-commutative Gröbner–Shirshov bases to obtain the monomial basis and the center of the universal envelope. We also determine the decomposition of the universal envelope and show that there exist only five finite-dimensional inequivalent irreducible representations of the Jordan triple system of all [Formula: see text] matrices.
Fabrication of a pH-Responsive 5-FU@MSN-SA Nanoplatform for Anti-Tumor Activity
Authors: Li Wenlong , Zhang Weiwei , Jin Weihao , Zhu Longbao , Li Wanzhen , Song Ping , Tao Yugui , Ge Fei
Published: February 2021

Design of high-performance drug delivery system is necessary to improve the anticancer ability of 5-fluorouracil (5-FU). In this work, we developed a pH-responsive 5-FU loaded and sodium alginate (SA) modified mesoporous silica nanoparticles (MSNs) drug delivery system (5-FU@MSN-SA). After 5-FU was loaded into the pores, MSNs were successfully functionalized with amino groups and then capped by sodium alginate. Compared to acidic conditions, the drug release rate in the neutral environment was quite low. Moreover, detailed investigations confirmed that 5-FU@MSN-SA can easily be up-taken by cancer cells and proved the high cytotoxicity to 4T1 cells. The calculated IC[Formula: see text] values for 5-FU and 5-FU@MSN-SA were 34.67[Formula: see text][Formula: see text][Formula: see text]g/mL and 54.95[Formula: see text][Formula: see text][Formula: see text]g/mL, respectively. These results indicated that 5-FU@MSNs-SA can be a promising nanoplatform in cancer therapy.
Influence of Sb2O3 doping on the sintering and polarization characteristics of PbTiO3 ceramic materials
Authors: Ri Chol-Nam , Ri Jong-Su , Ju Kwang-Ho
Published: February 2021

In this paper, the effect of Sb2O3 doping on the sintering and polarization stability of PbTiO3 ceramics was investigated. The Sb2O3-doped PbTiO3 ceramic materials were prepared viaa conventional piezoelectric ceramic processing. The results showed that the as-prepared PbTiO3 ceramics exhibit a good sintering stability without cracking during sintering because of reducing spontaneous strain stemmed from decrease the tetragonal degree of PbTiO3 by Sb2O3 doping. Furthermore, the polarization stability of Sb2O3-doped PbTiO3 ceramics was considerably enhanced by the relaxation of strain and stress concentration during poling stemmed from the formation of good microstructure with fine grain and high density, and by decreasing the loss stemmed from reduction of oxygen vacancy concentration due to the substitution of Sb[Formula: see text] ions for Ti[Formula: see text] ions under a polarization condition with temperature of 130–150[Formula: see text]C and applied electric field of 4.5–5.5 kV/mm, and its yield of polarization is achieved ca. 80%.
Critical temperature below the Curie temperature of ferroelectric ceramics PZT
Authors: Kuzenko D. V.
Published: February 2021

The article presents the results of research the pre-transitional features of the behavior of solid solutions based on lead zirconate-titanate. The presence of a “special” critical temperature [Formula: see text] on the temperature dependences of the permittivity [Formula: see text] and the remanent polarization [Formula: see text], preceding the temperature of the paraelectric phase transition at the Curie temperature [Formula: see text], is noted. In the temperature range [Formula: see text] < [Formula: see text], the [Formula: see text] dependence obeys a power law. In the temperature range [Formula: see text]<[Formula: see text]<[Formula: see text], this law is not fulfilled. The results of X-ray experiments make it possible to associate this behavior with reversible disordering at [Formula: see text]<[Formula: see text] of an ordered domain structure formed during the polarization of piezoelectric ceramics and with its irreversible disordering in the temperature range [Formula: see text]<[Formula: see text]<[Formula: see text]. This is due to the appearance of internal mechanical stresses in a polycrystalline ferroelectric due to irreversible depolarization of the samples at temperatures [Formula: see text]<[Formula: see text]<[Formula: see text].
Valuing Water Quality with Adaptation: Evidence from a Natural Experiment in Jordan
Authors: Morgan Seth , Baker Justin , Orgill-Meyer Jennifer , Jeuland Marc
Published: February 2021

Though water scarcity threats are increasing in severity across many regions of the world, allocation often remains inefficient — as in Jordan, the site of this study. One commonly discussed solution for increasing resource availability in water-scarce regions is the use of recycled wastewater for irrigation. Yet, despite significant potential benefits, an oft-cited concern with wastewater reuse is its potential impact on water quality. This paper examines the impact of this solution by exploiting a natural experiment arising from complementary infrastructure investments that introduced recycled wastewater to a new region of the Jordan Valley. We study farmer preferences for wastewater reuse, as well as farm adaptation and profitability. We find no evidence of negative impacts on farm revenues or costs over the short term, and observe signs of adaptation via the shifting of production toward less-salinity sensitive crops. Contingent valuation measures of the willingness to pay for reliable recycled water supply across newly treated and comparison areas indicate resistance to the expanded reuse of wastewater, however, which suggests that farmers may believe that this shift will entail more substantial long-term costs. Furthermore, the stated willingness to pay and short-term marginal productivity of water estimates appear unrelated. These results suggest the need for caution in interpreting short-term adaptation and preference responses to policies that substantially alter irrigation choices and behaviors, and point to the need for longer-term studies of wastewater reuse.
BRUCS: a new system for classifying and naming mappable rock units
Authors: Gillespie Martin R. , Graham Leslie A.
Published: February 2021

A new scheme is introduced for classifying and naming mappable rock bodies that lack primary stratification. In recognition of their distinctive geological characteristics, these ‘nonstratiform’ bodies are defined and classified according to their 3D form, spatial distribution and genetic relationships, in two hierarchical (parent–child) chains: one for intrusions and one for tectonometamorphic units. Geologically complex units, encompassing bodies of different genetic classes, are classified in a third chain reserved specifically for ‘mixed-class’ units. The new classification scheme is offered as an alternative to existing recommendations in the International Stratigraphic Guide and North American Stratigraphic Code, in which nonstratiform bodies are recognized and defined primarily by their lithological character. BRUCS (the
BGS Rock Unit Classification System
) combines the three new parent–child chains for nonstratiform units with the well-established chain for stratiform units (bed–member–formation–group–supergroup) to create a flexible, practical and effective solution for classifying and naming all mappable rock bodies. The taxonomic rigour of BRUCS means that the considerable capabilities of modern digital systems for managing and communicating mapping data can be exploited fully.
Leveraging the Defects Life Cycle to Label Affected Versions and Defective Classes
Authors: Vandehei Bailey , Costa Daniel Alencar Da , Falessi Davide
Published: February 2021

Two recent studies explicitly recommend labeling defective classes in releases using the affected versions (AV) available in issue trackers (e.g., Jira). This practice is coined as the
realistic approach
. However, no study has investigated whether it is feasible to rely on AVs. For example, how available and consistent is the AV information on existing issue trackers? Additionally, no study has attempted to retrieve AVs when they are unavailable. The aim of our study is threefold: (1) to measure the proportion of defects for which the realistic method is usable, (2) to propose a method for retrieving the AVs of a defect, thus making the realistic approach usable when AVs are unavailable, (3) to compare the accuracy of the proposed method versus three SZZ implementations. The assumption of our proposed method is that defects have a stable life cycle in terms of the proportion of the number of versions affected by the defects before discovering and fixing these defects. Results related to 212 open-source projects from the Apache ecosystem, featuring a total of about 125,000 defects, reveal that the realistic method cannot be used in the majority (51%) of defects. Therefore, it is important to develop automated methods to retrieve AVs. Results related to 76 open-source projects from the Apache ecosystem, featuring a total of about 6,250,000 classes, affected by 60,000 defects, and spread over 4,000 versions and 760,000 commits, reveal that the proportion of the number of versions between defect discovery and fix is pretty stable (standard deviation <2)—across the defects of the same project. Moreover, the proposed method resulted significantly more accurate than all three SZZ implementations in (i) retrieving AVs, (ii) labeling classes as defective, and (iii) in developing defects repositories to perform feature selection. Thus, when the realistic method is unusable, the proposed method is a valid automated alternative to SZZ for retrieving the origin of a defect. Finally, given the low accuracy of SZZ, researchers should consider re-executing the studies that have used SZZ as an oracle and, in general, should prefer selecting projects with a high proportion of available and consistent AVs.
Smartphone Sonar-Based Contact-Free Respiration Rate Monitoring
Authors: Wang Xuyu , Huang Runze , Yang Chao , Mao Shiwen
Published: February 2021

Vital sign (e.g., respiration rate) monitoring has become increasingly more important because it offers useful clues about medical conditions such as sleep disorders. There is a compelling need for technologies that enable contact-free and easy deployment of vital sign monitoring over an extended period of time for healthcare. In this article, we present a SonarBeat system to leverage a phase-based active sonar to monitor respiration rates with smartphones. We provide a sonar phase analysis and discuss the technical challenges for respiration rate estimation utilizing an inaudible sound signal. Moreover, we design and implement the SonarBeat system, with components including signal generation, data extraction, received signal preprocessing, and breathing rate estimation with Android smartphones. Our extensive experimental results validate the superior performance of SonarBeat in different indoor environment settings.