bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of Stresses Within the Boundary of Photoelastic Models
Authors: Weller R. , Shortley G. H.
Published: March 2021

A method is proposed for the determination of the internal stresses in a two-dimensional system from data furnished by a photoelastic analysis. The method involves the numerical integration of the Laplace difference equation over a region with known boundary values by the iteration of a set of improvement formulas. The underlying theory is discussed briefly, reference being made to a more mathematical treatment appearing in another paper by the authors. New procedures for increasing the speed and accuracy of such computations are described and application is made to a typical photoelastic study. In this the complete system of internal stresses is computed, using the data obtained from the usual fringe photograph, without recourse to isoclinic lines, or other supplementary experimental measurements. The method is also applicable to other problems of potential theory which involve the vanishing of the Laplacian. This includes electric fields, steady-state heat conduction, shapes of membranes, and problems in hydrodynamics and gravitation.
Creep, Elastic Hysteresis, and Damping in Bakelite Under Torsion
Authors: Leaderman Herbert
Published: March 2021

The creep in torsion of various forms of bakelite under constant load and the creep recovery on removal of load is found to follow closely the superposition principle or “memory law” of Boltzmann, if the previous maximum strain in a test is not exceeded. If the previous maximum strain is exceeded, an additional plastic flow takes place which is not, at any rate immediately, recoverable.

A function of the elapsed time called the “equivalent time” is introduced in order to analyze the creep and creep recovery when the loading history is complex.

A method is developed for calculating the stress-strain loop due to creep for step-by-step cyclic loading. Results of cyclic-loading tests reveal the presence of a true elastic-hysteresis loop in addition to the loop due to creep.

The specific damping capacity in torsion at a given stress, calculated from the measured creep and elastic-hysteresis loop, is shown to agree fairly well with the damping measured directly.
A Two-Load Method of Determining the Average True Stress-Strain Curve in Tension
Authors: MacGregor C. W.
Published: March 2021

The author describes a method, developed at the Massachusetts Institute of Technology, whereby the complete average true stress-strain curve in tension may be determined for a material from the beginning of yielding to fracture under ordinary testing speeds by the observation during the test of only two loads applied to a tapered specimen, namely, the maximum and fracture loads. Diameters at various positions along tapered specimens are measured before and after the test, and stress and reduction-of-area values computed from these observations.
Modeling Study on Reviving Abandoned Oil Reservoirs by In Situ Combustion Without CO2 Production While Recovering Both Oil and Heat
Authors: Han Yun , Li Kewen , Jia Lin
Published: March 2021

A large number of oil wells have been or will be abandoned around the world. Yet, a very large amount of oil and energy is left behind inside the rocks in abandoned reservoirs because of technological and economic limitations. The residual oil saturation is usually more than 40%, and in shale reservoirs it can be more than 90%. There have been many enhanced oil recovery methods developed to tap the residual oil and improve the oil recovery. Interestingly, a concept has been proposed to transfer abandoned oil and gas reservoirs into exceptional enhanced geothermal reservoirs by oxidizing the residual oil with injected air (Li and Zhang, 2008, “Exceptional Enhanced Geothermal Systems From Oil and Gas Reservoirs,” 43rd Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA). This methodology was referred to as an exceptional enhanced geothermal system (EEGS). However, zero CO2 production has not been achieved during the process of EEGS. To this end, numerical models of EEGS in abandoned oil reservoirs configured with vertical wells were established in the present study. Numerical simulations in different well configurations were conducted. The effects of well distance, perforation position, and formation permeability on the CO2 production and the reservoir temperature have been investigated. The numerical simulation results showed that when the depth difference between the production and the injection well perforation positions reaches a specific value, the daily CO2 production rate could be kept at almost zero for over 50 years or even permanently while producing oil and thermal energy continuously. This implies that we realized the concept of EEGS with no CO2 successfully using numerical simulation.
Heat Transfer in Rotating, Trailing-Edge, Converging Channels With Smooth Walls and Pin-Fins
Authors: Sahin Izzet , Chen I-Lun , Wright Lesley M. , Han Je-Chin , Xu Hongzhou , Fox Michael
Published: March 2021

The heat transfer and pressure drop characteristics of a rotating cooling channel that has an angled trapezoidal cross section and converges from the hub to the tip in both the streamwise and spanwise directions are experimentally investigated. The channel is oriented 120 deg with respect to the direction of rotation to model the geometry of an internal, trailing-edge cooling passage. Both the leading and trailing sides of the channel are divided into three and six regions in the spanwise and streamwise directions, respectively. The copper plate method is used to obtain regionally averaged heat transfer coefficients. The pressure drop is measured using pressure taps placed at the inlet and outlet of the channel. Experiments were conducted with the inlet Reynolds number ranging from 10,000 to 40,000. The rotational speed varies from 0 rpm to 300 rpm, resulting in the highest rotation number of 0.21. The effects of full pin-fins on the heat transfer and pressure drop characteristics are obtained and compared to the smooth surface converging channel results. The impact of the convergence, which causes variations of flow and geometric parameters through the passage, such as aspect ratio, Reynolds number, and rotation number, on the heat transfer coefficients and pressure drop are addressed. Results show that due to the 120 deg channel orientation, the rotation has a positive impact on the leading and trailing surface heat transfer. Furthermore, the convergence decreases the aspect ratio while increasing the Reynolds number. The convergence significantly enhances heat transfer on both the leading and trailing surfaces along the streamwise and spanwise directions. The convergence also reduces the rotation effect in the streamwise direction for a given mass flow rate.
An Additively Manufactured Four-Sensor Fast Response Aerodynamic Probe
Authors: Chasoglou Alexandros C. , Tsirikoglou Panagiotis , Kalfas Anestis I. , Abhari Reza S.
Published: March 2021

This study describes the design, development, and testing of a miniature fast response aerodynamic probe (FRAP) with four sensors (4S), which are able to perform measurements in the unsteady three-dimensional flow field. Moreover, the calibration and first results with the newly developed probe are provided. The miniature FRAP-4S demonstrates a 3 mm tip diameter, offering a 25% reduction in diameter size, in comparison to a first-generation FRAP-4S, without any loss in terms of measurement bandwidth. The 3 mm outer casing of the probe is additively manufactured with a high-precision binder jetting technique. In terms of aerodynamic performance, the probe demonstrates high angular sensitivity up to ± 18 deg incidence angle in both directions. To evaluate the measurement accuracy of the newly developed FRAP-4S, measurements are performed at the Laboratory for Energy Conversion (LEC) in both a round axisymmetric jet and an one-and-a-half stage, unshrouded and highly loaded axial turbine configuration. Turbulence measurements performed with the miniature FRAP-4S are compared against hot-wire studies in round free-jets found in the literature. Good agreement in both trends but also absolute values is demonstrated. Moreover, the performance of the probe is compared against traditional instrumentation developed at LEC, namely, miniature pneumatic and FRAP-2S probes. The results indicate that the FRAP-4S, despite its larger size in comparison to the other probes tested, can resolve the main flow patterns, with the highest deviations occuring in the presence of highly skewed and sheared flow. Furthermore, the additively manufactured probe was proven to be robust after more than 50 hours of testing in the representative turbine environment configuration. Finally, it should be highlighted that the newly developed FRAP reduces measurement time by a factor of three in comparison to FRAP-2S, which directly translates to reduced development time and thus cost during the turbomachinery development phase.
Shape optimization of acoustic horns for improved directivity control and radiation efficiency based on the multimodal method
Authors: Dong Hao , Gao Hao , Feng Xuelei , Shen Yong
Published: March 2021

The multimodal method is used to develop an approach for optimizing the shape of axisymmetric acoustic horns for both well-controlled directivity and high radiation efficiency over a wide frequency range. A horn with an arbitrary profile can be efficiently modeled with the multimodal method by projecting the wave field over transverse modes in connected short cylinders; the radii of the cylinders are used directly as design variables. Many design variables are employed in the optimization process to ensure design flexibility and computational accuracy. The relative weights for the design objectives of constant directivity, high radiation efficiency, and acceptable shape smoothness are adjusted by two coefficients in the objective function. The optimization problem is solved with a gradient-based algorithm, which takes advantage of algebraic gradient expressions. Numerical experiments demonstrate that the optimization procedure generates smooth horn contours that exhibit considerably improved performance over the target frequency band. Interestingly, a high-quality horn produced with moderate weight coefficients is similar in shape to constant-directivity horns invented earlier while having good low-frequency loading properties. The proposed method provides an attractive alternative to conventional horn design approaches.
Performance Assessment for Rock Climbers: The International Rock Climbing Research Association Sport-Specific Test Battery
Authors: Draper Nick , Giles David , Taylor Nicola , Vigouroux Laurent , España-Romero Vanesa , Baláš Jiří , Solar Altamirano Ignacio , Mally Franziska , Beeretz Ina , Couceiro Canalejo Jorge , Josseron Gabriel , Kodejška Jan , Arias Téllez María José , Cabeza de Vaca German Gallo
Published: March 2021

Purpose: To examine the validity and reliability of a battery of 10 measures designed to assess the key physiological parameters for successful rock climbing performance. Methods: In phase 1 of the research, an expert panel, using the Delphi method, established a 10-item test battery based on the key determinants of climbing performance. In phase 2, the tests were assessed for validity and reliability to examine their suitability as sport-specific measures of rock climbing performance. A total of 132 rock climbers, from 7 countries, volunteered to take part in the study. Each climber visited their nearest laboratory on 3 separate occasions in order to enable the required tests and retests to be completed. A minimum of 7 days was allowed between visits. Results: The 10 tests established for phase 2 were designed as sport-specific measures of flexibility, strength, power, and endurance. Results indicated that, while reliable, the flexibility and strength tests were only partially successful in differentiating across climber abilities. The power and endurance tests, however, performed well with regard to validity and reliability, with the finger hang and powerslap tests being most strongly correlated with performance ability (P < .0005 to P < .002). Conclusion: The authors’ data suggest that climbing may require a threshold level of flexibility and strength for successful performance, beyond which further improvements may not be required. In contrast, the finger hang and powerslap tests were not only reliable measures but also differentiated between climber abilities from lower grade to elite levels.
A venous-specific purinergic signaling cascade initiated by Pannexin 1 regulates TNFα-induced increases in endothelial permeability
Authors: Maier-Begandt Daniela , Comstra Heather Skye , Molina Samuel A. , Krüger Nenja , Ruddiman Claire A. , Chen Yen-Lin , Chen Xiaobin , Biwer Lauren A. , Johnstone Scott R. , Lohman Alexander W. , Good Miranda E. , DeLalio Leon J. , Hong Kwangseok , Bacon Hannah M. , Yan Zhen , Sonkusare Swapnil K. , Koval Michael , Isakson Brant E.
Published: March 2021

A pathway underlying the TNFα-induced decrease in endothelial barrier function is found in veins but not arteries.
Probiotic supplements and bone health in postmenopausal women: a meta-analysis of randomised controlled trials
Authors: Yu Jiawei , Cao Gaoyang , Yuan Shuohui , Luo Cong , Yu Jiafeng , Cai Ming
Published: March 2021

Objective

Osteoporosis is a common disease in postmenopausal women. Several studies have analysed the associations between dietary supplementation with probiotics and bone health in postmenopausal women, but the results are still controversial. We conducted this meta-analysis to assess the effects of probiotics supplement on bone mineral density (BMD) and bone turnover markers for postmenopausal women.

Design

Systematic review and meta-analysis.

Methods

We systematically searched PubMed, EMBASE and the Cochrane Library from their inception to November 2020 for randomised controlled trials (RCTs) assessing probiotic supplements and osteoporosis in postmenopausal women. Study-specific risk estimates were combined using random-effect models.

Results

Five RCTs (n=497) were included. Probiotic supplements were associated with a significantly higher BMD in the lumbar spine (standardised mean difference, SMD=0.27, 95% CI 0.09 to 0.44) than in control. There was no difference between probiotic supplements and BMD in hips (SMD=0.22, 95% CI −0.07 to 0.52). Collagen type 1 cross-linked C-telopeptide levels in the treatment groups were significantly lower than those of the placebo group (SMD=−0.34, 95% CI −0.60 to −0.09). In subgroup meta-analysis, levels of bone-specific alkaline phosphatase, osteoprotegerin, osteocalcin and tumour necrosis factor did not differ between the probiotic and placebo groups.

Conclusions

We conclude cautiously that supplementation with probiotics could increase lumbar BMD. More RCTs are recommended to validate or update these results.
Temporal trends in heart failure medication prescription in a population-based cohort study
Authors: Uijl Alicia , Vaartjes Ilonca , Denaxas S , Hemingway Harry , Shah Anoop , Cleland J , Grobbee Diederick , Hoes Arno , Asselbergs Folkert W , Koudstaal Stefan
Published: March 2021

Objective

We examined temporal heart failure (HF) prescription patterns in a large representative sample of real-world patients in the UK, using electronic health records (EHR).

Methods

From primary and secondary care EHR, we identified 85 732 patients with a HF diagnosis between 2002 and 2015. Almost 50% of patients with HF were women and the median age was 79.1 (IQR 70.2–85.7) years, with age at diagnosis increasing over time.

Results

We found several trends in pharmacological HF management, including increased beta blocker prescriptions over time (29% in 2002–2005 and 54% in 2013–2015), which was not observed for mineralocorticoid receptor-antagonists (MR-antagonists) (18% in 2002–2005 and 18% in 2013–2015); higher prescription rates of loop diuretics in women and elderly patients together with lower prescription rates of angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers, beta blockers or MR-antagonists in these patients; little change in medication prescription rates occurred after 6 months of HF diagnosis and, finally, patients hospitalised for HF who had no recorded follow-up in primary care had considerably lower prescription rates compared with patients with a HF diagnosis in primary care with or without HF hospitalisation.

Conclusion

In the general population, the use of MR-antagonists for HF remained low and did not change throughout 13 years of follow-up. For most patients, few changes were seen in pharmacological management of HF in the 6 months following diagnosis.
Personal protective equipment for reducing the risk of COVID-19 infection among healthcare workers involved in emergency trauma surgery during the pandemic: an umbrella review protocol
Authors: Griswold Dylan P , Gempeler Andres , Kolias Angelos G , Hutchinson Peter J , Rubiano Andres M
Published: March 2021

Introduction

Many healthcare facilities in low-income and middle-income countries are inadequately resourced and may lack optimal organisation and governance, especially concerning surgical health systems. COVID-19 has the potential to decimate these already strained surgical healthcare services unless health systems take stringent measures to protect healthcare workers (HCWs) from viral exposure and ensure the continuity of specialised care for patients. The objective of this broad evidence synthesis is to identify and summarise the available literature regarding the efficacy of different personal protective equipment (PPE) in reducing the risk of COVID-19 infection in health personnel caring for patients undergoing trauma surgery in low-resource environments.

Methods

We will conduct several searches in the L·OVE (Living OVerview of Evidence) platform for COVID-19, a system that performs automated regular searches in PubMed, Embase, Cochrane Central Register of Controlled Trials and over 30 other sources. The search results will be presented according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. This review will preferentially consider systematic reviews of experimental and quasi-experimental studies, as well as individual studies of such designs, evaluating the effect of different PPE on the risk of COVID-19 infection in HCWs involved in emergency trauma surgery. Critical appraisal of eligible studies for methodological quality will be conducted. Data will be extracted using the standardised data extraction tool in Covidence. Studies will, when possible, be pooled in a statistical meta-analysis using JBI SUMARI. The Grading of Recommendations, Assessment, Development and Evaluation approach for grading the certainty of evidence will be followed and a summary of findings will be created.

Ethics and dissemination

Ethical approval is not required for this review. The plan for dissemination is to publish review findings in a peer-reviewed journal and present findings at high-level conferences that engage the most pertinent stakeholders.

PROSPERO registration number

CRD42020198267.
Changes in gastric mucosal microbiota in gastric carcinogenesis: a systematic review protocol
Authors: Ji Ruoyu , Zhao Xinyu , Cao Xinyuan , Zhang Yizhen , Yang Yingyun
Published: March 2021

Introduction

The human stomach is a complex and diverse microbial ecosystem. Consecutive alternations of gastric microbiota occur in gastric carcinogenesis, while the changing pattern during this process remains controversial across studies. We aim to identify the changes in the diversity and composition of gastric mucosal microbiota in gastric tumorigenesis.

Methods and analysis

We will search through PubMed, EMBASE and Cochrane databases, as well as conference proceedings and references of review articles for observational articles reporting either the relative abundance of bacteria at the phylum or genus level or at least one of the alpha diversity indexes respectively and clearly in both gastric cancer and non-cancer groups. Selection of studies and data extraction will be performed independently by two researchers. Disagreements will be resolved through discussion. Risk of bias will be assessed using the modified Newcastle-Ottawa Scale. Quantitative analyses will be performed using a random effects model, where the effect measurement will be expressed as the MD.

Ethics and dissemination

Ethical approval for this systematic review is not required, as the study is based exclusively on published documents and will not include any individual data. Findings of this study are expected to be disseminated through peer-reviewed journals or conference proceedings.

PROSPERO registration number

CRD42020206973.
Multicentre stepped-wedge cluster randomised controlled trial of an antimicrobial stewardship programme in residential aged care: protocol for the START trial
Authors: Jokanovic Natali , Haines Terry , Cheng Allen C , Holt Kathryn E , Hilmer Sarah N , Jeon Yun-Hee , Stewardson Andrew J , Stuart Rhonda L , Spelman Tim , Peel Trisha N , Peleg Anton Y
Published: March 2021

Introduction

Antimicrobial resistance is a growing global health threat, driven by increasing inappropriate use of antimicrobials. High prevalence of unnecessary use of antimicrobials in residential aged care facilities (RACFs) has driven demand for the development and implementation of antimicrobial stewardship (AMS) programmes. The Stepped-wedge Trial to increase antibiotic Appropriateness in Residential aged care facilities and model Transmission of antimicrobial resistance (START) will implement and evaluate the impact of a nurse-led AMS programme on antimicrobial use in 12 RACFs.

Methods and analysis

The START trial will implement and evaluate a nurse-led AMS programme via a stepped-wedge cluster randomised controlled trial design in 12 RACFs over 16 months. The AMS programme will incorporate education, aged care-specific treatment guidelines, documentation forms, and audit and feedback strategies that will target aged care staff, general practitioners, pharmacists, and residents and their families. The intervention will primarily focus on urinary tract infections, lower respiratory tract infections, and skin and soft tissue infections. RACFs will transition from control to intervention phases in random order, two at a time, every 2 months, with a 2-month transition, wash-in period. The primary outcome is the cumulative proportion of residents within each facility prescribed an antibiotic during each month and total days of antibiotic use per 1000 occupied bed days. Secondary outcomes include the number of courses of systemic antimicrobial therapy, antimicrobial appropriateness, antimicrobial resistant organisms,Clostridioides difficileinfection, change in antimicrobial susceptibility profiles, hospitalisations and all-cause mortality. Analyses will be conducted according to the intention-to-treat principle.

Ethics and dissemination

Ethics approval has been granted by the Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/591). Research findings will be disseminated through peer-reviewed publications, conferences and summarised reports provided to participating RACFs.

Trial registration number

NCT03941509.
Tumor-derived ILT4 induces T cell senescence and suppresses tumor immunity
Authors: Gao Aiqin , Liu Xia , Lin Wenli , Wang Jingnan , Wang Shuyun , Si Fusheng , Huang Lan , Zhao Yangjing , Sun Yuping , Peng Guangyong
Published: March 2021

Background

Current immunotherapies including checkpoint blockade therapy have limited success rates in certain types of cancers. Identification of alternative checkpoint molecules for the development of effective strategies for tumor immunotherapy is urgently needed. Immunoglobulin-like transcript 4 (ILT4) is an immunosuppressive molecule expressed in both myeloid innate cells and malignant tumor cells. However, the role of tumor-derived ILT4 in regulating cancer biology and tumor immunity remains unclear.

Methods

ILT4 expression in tumor cells and patient samples was determined by real-time PCR, flow cytometry, and immunohistochemistry. T cell senescence induced by tumor was evaluated using multiple markers and assays. Moreover, metabolic enzyme and signaling molecule expression and lipid droplets in tumor cells were determined using real-time PCR, western blot and oil red O staining, respectively. Loss-of-function and gain-of-function strategies were used to identify the causative role of ILT4 in tumor-induced T cell senescence. In addition, breast cancer and melanoma mouse tumor models were performed to demonstrate the role of ILT4 as a checkpoint molecule for tumor immunotherapy.

Results

We reported that ILT4 is highly expressed in human tumor cells and tissues, which is negatively associated with clinical outcomes. Furthermore, tumor-derived ILT4/PIR-B (ILT4 ortholog in mouse) is directly involved in induction of cell senescence in naïve/effector T cells mediated by tumor cells in vitro and in vivo. Mechanistically, ILT4/PIR-B increases fatty acid synthesis and lipid accumulation in tumor cellsviaactivation of MAPK ERK1/2 signaling, resulting in promotion of tumor growth and progression, and induction of effector T cell senescence. In addition, blocking tumor-derived PIR-B can reprogram tumor metabolism, prevent senescence development in tumor-specific T cells, and enhance antitumor immunity in both breast cancer and melanoma mouse models.

Conclusions

These studies identify a novel mechanism responsible for ILT4-mediated immune suppression in the tumor microenvironment, and prove a novel concept of ILT4 as a critical checkpoint molecule for tumor immunotherapy.
Thermodynamics of asymptotically flat Reissner–Nordstrom black hole
Authors: Sinha Aloke Kumar
Published: March 2021

We established the criteria for thermal stability of a most general black hole in the form of a series of inequalities connecting second-order derivatives of the black hole mass with respect to its parameters. The mass of a black hole depends solely on these parameters, e.g. horizon area and electric charge are these parameters for non-rotating charged black hole. We also introduced the notion of “Quasi stability”. It is known how to calculate the fluctuations of these parameters for both stable and quasi stable black holes. In this paper, we consider the simplest black hole having nontrivial parameter, i.e. electrically charged non-rotating asymptotically flat Reissner–Nordstrom black hole (AFRNBH). We will show here that this black hole is not stable anywhere in its parameter space, but it is actually quasi stable, having positive specific heat in some region, violating Hawking’s prediction. In fact, this black hole will be shown to exhibit phase transition which is structurally quite different from that in case of Schwarzschild black hole, as predicted first by Hawking. This black hole will also be shown to try to resist its decay under Hawking radiation, but ultimately remains unsuccessful.
Sharp discontinuous traveling waves in a hyperbolic Keller–Segel equation
Authors: Fu Xiaoming , Griette Quentin , Magal Pierre
Published: March 2021

In this work, we describe a hyperbolic model with cell–cell repulsion with a dynamics in the population of cells. More precisely, we consider a population of cells producing a field (which we call “pressure”) which induces a motion of the cells following the opposite of the gradient. The field indicates the local density of population and we assume that cells try to avoid crowded areas and prefer locally empty spaces which are far away from the carrying capacity. We analyze the well-posedness property of the associated Cauchy problem on the real line. We start from bounded initial conditions and we consider some invariant properties of the initial conditions such as the continuity, smoothness and monotony. We also describe in detail the behavior of the level sets near the propagating boundary of the solution and we find that an asymptotic jump is formed on the solution for a natural class of initial conditions. Finally, we prove the existence of sharp traveling waves for this model, which are particular solutions traveling at a constant speed, and argue that sharp traveling waves are necessarily discontinuous. This analysis is confirmed by numerical simulations of the PDE problem.
New primal and dual-mixed finite element methods for stable image registration with singular regularization
Authors: Barnafi Nicolás , Gatica Gabriel N. , Hurtado Daniel E. , Miranda Willian , Ruiz-Baier Ricardo
Published: March 2021

This work introduces and analyzes new primal and dual-mixed finite element methods for deformable image registration, in which the regularizer has a nontrivial kernel, and constructed under minimal assumptions of the registration model: Lipschitz continuity of the similarity measure and ellipticity of the regularizer on the orthogonal complement of its kernel. The aforementioned singularity of the regularizer suggests to modify the original model by incorporating the additional degrees of freedom arising from its kernel, thus granting ellipticity of the former on the whole solution space. In this way, we are able to prove well-posedness of the resulting extended primal and dual-mixed continuous formulations, as well as of the associated Galerkin schemes. A priori error estimates and corresponding rates of convergence are also established for both discrete methods. Finally, we provide numerical examples confronting our formulations with the standard ones, which prove our finite element methods to be particularly more efficient on the registration of translations and rotations, in addition for the dual-mixed approach to be much more suitable for the quasi-incompressible case, and all the above without losing the flexibility to solve problems arising from more realistic scenarios such as the image registration of the human brain.
Final size and convergence rate for an epidemic in heterogeneous populations
Authors: Almeida Luis , Bliman Pierre-Alexandre , Nadin Grégoire , Perthame Benoît , Vauchelet Nicolas
Published: March 2021

We formulate a general SEIR epidemic model in a heterogeneous population characterized by some trait in a discrete or continuous subset of a space [Formula: see text]. The incubation and recovery rates governing the evolution of each homogeneous subpopulation depend upon this trait, and no restriction is assumed on the contact matrix that defines the probability for an individual of a given trait to be infected by an individual with another trait. Our goal is to derive and study the final size equation fulfilled by the limit distribution of the population. We show that this limit exists and satisfies the final size equation. The main contribution of this work is to prove the uniqueness of this solution among the distributions smaller than the initial condition. We also establish that the dominant eigenvalue of the next-generation operator (whose initial value is equal to the basic reproduction number) decreases along every trajectory until a limit smaller than 1. The results are shown to remain valid in the presence of a diffusion term. They generalize previous works corresponding to finite number of traits (including metapopulation models) or to rank 1 contact matrices (modeling e.g. susceptibility or infectivity presenting heterogeneity independently of one another).
POLYNOMIAL TERM STRUCTURE MODELS
Authors: CHENG SI , TEHRANCHI MICHAEL R.
Published: March 2021

In this paper, we explore a class of tractable interest rate models that have the property that the price of a zero-coupon bond can be expressed as a polynomial of a state diffusion process. Our results include a classification of all such time-homogeneous single-factor models in the spirit of Filipović’s maximal degree theorem for exponential polynomial models, as well as an explicit characterization of the set of feasible parameters in the case when the factor process is bounded. Extensions to time-inhomogeneous and multi-factor polynomial models are also considered.
A Fuzzy MCDM Method Based on New Fermatean Fuzzy Theories
Authors: Aydın Serhat
Published: March 2021

This paper presents a new Multi-criteria Decision-Making (MCDM) method with Fermatean fuzzy sets (FFSs). The proposed method uses the entropy theory to determine the weights of criteria and utilize cosine similarity measures to determine the best alternative. First, we develop a new Fermatean fuzzy entropy formula based on the Euclidean distance between Fermatean fuzzy number (FFN) and its compliment. The properties of the proposed formula and the proof of the properties are also given. Then, Fermatean fuzzy cosine similarity measures are introduced. We develop four different Fermatean fuzzy cosine similarity measures, also properties and proof of the properties are worked out systematically. Then, the algorithm of the proposed Fermatean fuzzy MCDM method, which includes Fermatean fuzzy entropy and Fermatean fuzzy cosine similarity measures, is introduced. The advantage of the proposed method is that Fermatean fuzzy entropy calculates how much valuable knowledge the current data provides in weights of criteria, and Fermatean fuzzy cosine similarity measures define the similarity between alternatives and ideal solution and negative ideal solution, in this way the method determines the best alternative smoothly. To show the applicability of the proposed method, an illustrative example is given for third party logistic (3PL) firm evaluation problem in cold chain management. In the illustrative example section, we determine six different criteria and six different 3PL alternatives. Then, alternatives are evaluated according to the proposed Fermatean fuzzy MCDM method. Moreover, the results are compared to the Euclidean measure, and sensitivity analysis is also performed. The comparison analysis results show that our model works efficiently and effectively.
Ideals and Bosbach States on Residuated Lattices
Authors: Woumfo Francis , Koguep Njionou Blaise B. , Temgoua Alomo Etienne R. , Lele Celestin
Published: March 2021

In random experiments, the fact that the sets of events has a structure of a Boolean algebra, i.e. it follows the rules of classical logic, is the main hypothesis of classical probability theory. Bosbach states have been introduced on commutative and non-commutative algebras of fuzzy logics as a way of probabilistically evaluating the formulas. In this paper, we focus on the relationship between some properties of ideals and Bosbach states in the framework of commutative residuated lattices. In particular, we introduce the concept of co-kernel of a Bosbach state which is an ideal and we establish the relationship between the notion of co-kernel and the kernel. Moreover, we define and characterize maximal ideals and maximal MV-ideals in residuated lattices.
On LM-Valued F-Transforms, LM-Valued Fuzzy Rough Sets and LM-Valued Fuzzy Transformation Systems
Authors: Tripathi Abha , Tiwari S. P. , Singh Anand P.
Published: March 2021

The goal of this contribution is to propose [Formula: see text]-valued [Formula: see text]-transforms, which are essentially the many-valued generalizations of the notion of lattice-valued [Formula: see text]-transforms. Further, we associate the concepts of [Formula: see text]-valued fuzzy rough sets and [Formula: see text]-graded fuzzy topologies/co-topologies with [Formula: see text]-valued [Formula: see text]-transforms. Moreover, we show an interesting relationship between [Formula: see text]-valued [Formula: see text]-transforms and [Formula: see text]-valued fuzzy transformation systems.
Theory of Mutant Soft Set in Abstract Biology
Authors: Kandemi̇r Mustafa Burç
Published: March 2021

In this paper, we have established the concept of mutant soft set for algebraic formalization of biological mutation, and examined its structural properties.
Fabrication of p-n Junction (Ni/Zn)O and Reduced Graphene Oxide (rGO) Nanocomposites for the Electrocatalysis of Analgesic Drug (Acetaminophen) Detection in Pharmaceutical and Biological Samples
Authors: Tamilalagan Elayappan , Vetri Selvi Subash , Chen Shen-Ming , Akilarasan Muthumariappan , Maheshwaran Selvarasu , Chen Tse-Wei , Al-Mohaimeed Amal M. , Al-onazi Wedad A. , Soliman Elshikh Mohamed , Liu Xiaoheng
Published: March 2021

The p-n junction (Ni/Zn)O and its reduced graphene oxide nanocomposites ((Ni/Zn)O@rGO) has been synthesized through the hydrothermal method and used for effective electrochemical determination analgesic drug acetaminophen (AAP). In addition, the XRD characteristic peak and Raman modes confirm the formation of a p-n junction (Ni/Zn)O@rGO nanocomposites. The morphology of the as-prepared nanocomposites exposes nano-sized spherical particles that were well decorated on the rGO sheets, which results in a larger surface area. Further, the incorporation rGO and (Ni/Zn)O induced the catalytic properties and electrochemical performance. The electrochemical characterization of AAP was investigated at ((Ni/Zn)O@rGO/GCE) glass carbon electrode and differential pulse voltammetry (DPV) were adopted for the quantitative analysis of AAP. As a result, the prepared nanocomposite possessed great sensitivity, selectivity and stability. Further, the prepared sensor shows the wider linear range of 0.009–0.096 μM and 0.096–413 μM with a very low detection limit of 2.2 nM. Moreover, the practical applicability of the prepared sensor was tested in the pharmaceutical and human urine samples. Also, the developed method would widen the application of nanocomposites materials in the fabrications of more novel electrochemical sensing platforms.
Perspective—Quasi-Babinet Complementary Plasmonic Templates: A Platform to Perform Spectroelectrochemistry
Authors: Akinoglu Goekalp Engin , Hutchison James Andell
Published: March 2021

Plasmonic bilayers fabricated by depositing metal on nanopillar or nanocavity arrays are an effective solution for the industrial scale production of plasmonic templates. Such structures commonly consist of a disk array and a quasi-Babinet complementary perforated film comprised of holes, which are displaced vertically by the pillar or cavity. Simultaneously, the continuous perforated film provides an electrically conductive network, which can be used as a working electrode. In this perspective, we briefly review the nanofabrication of plasmonic bilayer templates and their usage for applications in life science. We discuss quasi-Babinet complementary plasmonic templates as a potential platform to study membrane proteins through spectro-electrochemical investigations.
Redox Cycling at an Array of Interdigitated Bipolar Electrodes for Enhanced Sensitivity in Biosensing
Authors: Borchers Janis S. , Campbell Claire , Van Scoy Savanah B. , Clark Morgan J. , Anand Robbyn
Published: March 2021

An array of many bipolar electrodes (BPEs) can be controlled by a single pair of driving electrodes yet allows for multiplexedanalysis of many individual biomarkers or single cells at once. A wide range of bipolar electrochemical sensors have been devised, many of which operate under battery power and produce visible signals (e.g., luminescent, electrochromic) appropriate for smartphone or naked eye readout. These features of BPEs are advantageous in the context of clinical and environmental sensing applications at the point of need. However, the sensitivity of BPEs is poor in comparison to direct measurement of current at an individual electrode, and therefore, the enhancement of signals obtained at BPEs is an active area of research. Here, we describe signal amplification by redox cycling accomplished by interdigitation of each BPE in an array with a shared driving electrode. We evaluate amplification obtained for interelectrode spacing in the range of 35 𝜇m to 15 𝜇m. Each interdigitated BPE (IDBPE) in the array has an independent, reproducible, and linear response to a reversible electroactive analyte. Therefore, this universal amplification strategy allows for multiplexed or spatially resolved sensing in point-of-need applications.
Antidiarrheal Effect of Zornia brasiliensis Vogel (Leguminosae) on Mice Involves Adrenergic Pathway Activation
Authors: Oliveira Filipe R. M. B. , Ferreira Sarah R. D. , Aires-Moreno Giulyane T. , Silva Anne D. S. , Nascimento Yuri M. , Costa Vicente C. O. , Tavares Josean F. , Silva Marcelo S. , Cavalcante Fabiana A.
Published: March 2021

Several secondary metabolites have been isolated from Zornia brasiliensis (Leguminosae), mainly flavonoids. These compounds are known for many pharmacological actions, such as antispasmodic and antidiarrheal. Therefore, we evaluated the antidiarrheal effect of the ethanolic extract obtained from Zornia brasiliensis aerial parts (ZB-EtOHAP), as well as its underlying mechanisms. Castor-oil-induced diarrhea, fluid accumulation, and intestinal transit (normal and castor oil induced) were performed to assess the antidiarrheal, antisecretory, and antipropulsive activities of the extract. The involvement of opioid and adrenergic pathways was also investigated. ZB-EtOHAP inhibited, in a dose-dependent manner, both total defecation frequency and the number of watery stools. The extract showed no effect on fluid accumulation or normal intestinal transit. On the other hand, when the animals were pretreated with castor oil, the extract decreased the distance traveled by the marker in the small intestine. Investigation of the involvement of opioid and adrenergic systems showed that the pharmacological potency of the extract did not change in the presence of naloxone, but it was reduced in the presence of yohimbine. The data indicate that Zornia brasiliensis has an antidiarrheal effect due to inhibition of the intestinal motility through adrenergic pathway activation.
The Optimization Algorithm for Large‐Scale In Situ Stress Field
Authors: Li Fei , Chang Ningdong
Published: March 2021

In situ stress state is a predominant factor for the design and safe construction of geotechnical engineering. For a real construction site, the amount of calculation using a finite element method for in situ stress field increases dramatically with the increase of the calculation freedom due to large‐scale uncertainties. In order to reduce the computing cost without losing the accuracy of the calculation, an optimization algorithm combined with a reduced order model, which is realized by the proper orthogonal decomposition algorithm (POD) for large‐scale in situ stress field, is put forward in this paper. The POD algorithm produces a set of orthogonal bases through the extraction of the field variables, combining with the Galerkin finite element method to create a reduced order numerical model. The reduced order model is then calculated with a global optimization algorithm to inversely find the solution for the actual in situ stress field. In order to verify the accuracy and efficiency of the method, two examples are presented to simulate the inverse calculation of the in situ stress field. They showed that the computation time of the POD method could reach 1/10 of the ordinary computation time. Also, the results showed good accuracy with a minimum computational expense, which can provide a reference for inverse calculation of large‐scale in situ stress field.
Analysis of Characteristics of Tennis Singles Matches Based on 5G and Data Mining Technology
Authors: Li Ming , Li Qinsheng , Li Yuening , Cui Yunkun , Zhao Xiufeng , Guo Lei
Published: March 2021

The level of technical and tactical decision-making in a tennis game has a very important impact on the outcome of the game. How to discover the characteristics and rules of the game from a large amount of technical and tactical data, how to overcome the shortcomings of traditional statistical methods, and how to provide a scientific basis for correct decision-making are a top priority. Based on 5G and association analysis data mining theory, we established a data mining model for tennis technical offensive tactics and association rules and conducted specific case studies. It can calculate the maximization and distribution rate of certain technologies, also distinguish between the athlete’s gain and loss rate and the spatial position on the track, and use artificial statistical methods to cause errors and subjective participation. This solution provides objective and scientific decision support for this problem and is used in the decision-making of the landing point in tennis match technology and tactics. Experimental simulation shows that the data mining technology analysis system used for regional tennis matches is more concise, efficient, and accurate than traditional movie analysis methods.
About Partial Reachability Issues in an SEIR Epidemic Model and Related Infectious Disease Tracking in Finite Time under Vaccination and Treatment Controls
Authors: De la Sen Manuel , Ibeas Asier , Nistal Raul
Published: March 2021

This paper studies some basic properties of an SEIR (Susceptible-Exposed-Infectious-Recovered) epidemic model subject to vaccination and treatment controls. Firstly, the basic stability, boundedness, and nonnegativity of the state trajectory solution are investigated. Then, the problem of partial state reachability from a certain state value to a targeted one in finite time is focused on since it turns out that epidemic models are, because of their nature, neither (state) controllable from a given state to the origin nor reachable from a given initial condition. The particular formal statement of the partial reachability is focused on as a problem of output-reachability by defining a measurable output or lower dimension than that of the state. A special case of interest is that when the output is defined as the infectious subpopulation to be step-to-step tracked under suitable amounts being compatible with the required constraints. As a result, and provided that the output-controllability Gramian is nonsingular on a certain time interval of interest, a feedback control effort might be designed so that a prescribed value of the output can be approximately tracked. A linearization approximation is performed to simplify and facilitate the above task which is based on a point-to-point linearization of the solution trajectory. To this end, an “ad hoc” sampled approximate output trajectory is defined as control objective to be targeted through a point-wise calculated Jacobian matrix. A supervised appropriate restatement of the targeted suited sampled output values is redefined, if necessary, to make the initial proposed sampled trajectory compatible with the various needed constraints on nonnegativity and control boundedness. The design can be optionally performed under constant or adaptive sampling rates. Finally, some numerical examples are given to test the theoretical aspects and the design efficiency of the model.
Hormetic Effects of Bioactive Compounds from Foods, Beverages, and Food Dressing: The Potential Role in Spinal Cord Injury
Authors: Fedullo Anna Lucia , Ciccotti Mario , Giannotta Paolo , Alviti Federica , Bernardi Marco , Raguzzini Anna , Toti Elisabetta , Sciarra Tommaso , Peluso Ilaria
Published: March 2021

Spinal cord injury (SCI) is a damage or trauma to the spinal cord resulting in a total or partial loss of motor and sensory function. SCI is characterized by a disequilibrium between the production of reactive oxygen species and the levels of antioxidant defences, causing oxidative stress and neuroinflammation. This review is aimed at highlighting the hormetic effects of some compounds from foods, beverages, and food dressing that are able to reduce oxidative stress in patients with SCI. Although curcumin, ginseng, and green tea have been proposed for SCI management, low levels of antioxidant vitamins have been reported in individuals with SCI. Mediterranean diet includes food rich in vitamins and antioxidants. Moreover, food dressing, including spices, herbs, and extra virgin olive oil (EVOO), contains multiple components with hormetic effects. The latter involves the activation of the nuclear factor erythroid‐derived 2, consequently increasing the antioxidant enzymes and decreasing inflammation. Furthermore, EVOO improves the bioavailability of carotenoids and could be a delivery system for bioactive compounds. In conclusion, Mediterranean dressing in addition to plant foods can have an important effect on redox balance in individuals with SCI.