bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and factors associated with false hyperkalaemia in Asians in primary care: a cross-sectional study (the Unlysed Hyperkalaemia- the Unseen Burden (UHUB) study)
Authors: Boo Alicia Ying Ying , Koh Yi Ling Eileen , Hu Pei Lin , Tan Ngiap Chuan
Published: September 2020

Serum potassium is part of routine laboratory tests done for patients with hypertension or diabetes mellitus in primary care. Those found to have raised potassium (K>5.5 mmol/L) are recalled for repeat potassium in emergency departments or primary care clinics. Repeat potassium are often normal (≤5.5 mmo/L), that is, false hyperkalaemia. Haemolysis is known to cause false hyperkalaemia. We postulated that unlysed false hyperkalamia was prevalent and was associated with factors such as delayed processing time.

Objective

We aimed to determine the prevalence of unlysed false hyperkalaemia and the factors associated with false-and-true-hyperkalaemia.

Setting

Outpatients in a cluster of public primary care clinics (polyclinics) in Singapore.

Participants

All patients of any ethnicity aged ≥21 with serum potassium test done.

Methods

Electronic health records of index patients with potassium >5.5 mmol/L and its corresponding laboratory processing time in seven local polyclinics were reviewed between August 2015 and August 2017. Haemolysed specimens and patients on sodium polystyrene sulfonate (SPS) suspension were excluded. If repeat potassium level was ≤5.5 mmol/L within 8 days, the case was defined as false hyperkalaemia. The proportion of such patients was computed to determine its prevalence. Linear and logistic regressions were used to identify the associated factors.

Results

The study population comprised of 3014 index cases, of which 1575 had repeat potassium tests without preceding SPS. 86.4% (1362/1575) of them had potassium ≤5.5 mmol/L. The average processing time among specimens with potassium ≥6.0 mmol/L was 50 min longer, compared with those with potassium <5.1 mmol/L. Risk factors significantly associated with false hyperkalaemia included estimated glomerular filtration rate (eGFR) (60–89 mL/min/1.73 m2, OR=3.25, p<0.001;>90 mL/min/1.73 m2, OR=3.77, p<0.001) and delayed laboratory processing time (beta coefficient 0.001, p<0.001).

Conclusion

The prevalence of false hyperkalaemia was 86.4%. Recommendation to repeat potassium tests may target those with eGFR<60ml/min/1.73m2.
Predictors of oral anticoagulant-associated adverse events in seniors transitioning from hospital to home: a retrospective cohort study protocol
Authors: Benipal Harsukh , Holbrook Anne , Paterson J. Michael , Douketis James , Foster Gary , Thabane Lehana
Published: September 2020

Introduction

Oral anticoagulants (OACs) are widely prescribed in older adults. High OAC-related adverse event rates in the early period following hospital discharge argue for an analysis to identify predictors. Our objective is to identify and validate clinical and continuity of care variables among seniors discharged from hospital on an OAC, which are independently associated with OAC-related adverse events within 30 days.

Methods and analysis

We propose a population-based retrospective cohort study of all adults aged 66 years or older who were discharged from hospital on an OAC from September 2010 to March 2015 in Ontario, Canada. The primary outcome is a composite of the first hospitalisation or emergency department visit for a haemorrhage or thromboembolic event or mortality within 30 days of hospital discharge. A Cox proportional hazards model will be used to determine the association between the composite outcome and a set of prespecified covariates. A split sample method will be adopted to validate the variables associated with OAC-related adverse events.

Ethics and dissemination

The use of data in this project was authorised under section 45 of Ontario’s Personal Health Information Protection Act, which does not require review by a research ethics board. Results will be disseminated via peer-reviewed publications and presentations at conferences and will determine intervention targets to improve OAC management in upcoming randomised trials.

Trial registration number

ClinicalTrials.gov Identifier:NCT02777047; Pre-results.
Neuroendocrine tumours: what gastroenterologists need to know
Authors: Khan Mohid S , Pritchard D Mark
Published: September 2020

Gastroenterologists are intermittently involved in diagnosing and managing patients who have neuroendocrine tumours (NETs). However, few UK gastroenterologists have received extensive training about this topic. This article aims to provide a brief introduction to NETs; it is aimed at a general gastroenterologist audience.

NETs present in diverse ways and many symptomatic patients unfortunately experience significant delays in diagnosis. Comprehensive evaluation of a patient with a possible NET involves assessing their symptoms, the tumour’s primary organ of origin, its differentiation status, grade and stage, whether the NET is secreting hormones and whether there is any underlying hereditary predisposition. Such assessment often needs specialist investigations such as nuclear medicine scans. All these factors influence patient management and prognosis, so a patient’s case and investigations should always be discussed by a fully constituted NET multidisciplinary team. Most localised tumours are considered for resection, but there are multiple treatment options for metastatic disease and many patients receive several different therapies during the course of their illness. The most common first line treatment in patients who have metastatic low grade NETs is monthly long acting somatostatin analogue injections. Prognosis is highly variable, but some patients who have inoperable metastases survive for many years on treatment with good quality of life. Gastroenterologists may also be involved in managing the non-tumour associated chronic gastrointestinal problems that some patients experience. Their involvement has been shown to improve patient-reported outcomes and quality of life.
Globotriaosylsphingosine (lyso-Gb3) and analogues in plasma and urine of patients with Fabry disease and correlations with long-term treatment and genotypes in a nationwide female Danish cohort
Authors: Effraimidis Grigoris , Feldt-Rasmussen Ulla , Rasmussen Åse Krogh , Lavoie Pamela , Abaoui Mona , Boutin Michel , Auray-Blais Christiane
Published: September 2020

Introduction

Recent studies showed the usefulness of globotriaosylsphingosine (lyso-Gb3) and related analogues, deacylated forms of globotriaosylceramide (Gb3), for high-risk screening, treatment monitoring and follow-up for patients with Fabry disease.

Methods

We evaluated Gb3, lyso-Gb3 and analogues using tandem mass spectrometry in 57 women with Fabry disease followed during a period of 15.4 years. Twenty-one women were never treated and 36 received treatment (agalsidase-beta, n=30; agalsidase-alfa, n=5; or migalastat, n=1). Lyso-Gb3 and analogues at m/z (−28), (−2), (+16), (+34) and (+50) were analysed in plasma and urine. Total Gb3 and lyso-Gb3 analogues at m/z (−12) and (+14) were evaluated in urine while the analogue at m/z (+18) was evaluated in plasma.

Results

A strong correlation between plasma and urine lyso-Gb3 and analogue levels was revealed. Plasma and urine lyso-Gb3 and analogue levels were not statistically different between patients carrying missense (n=49), nonsense (n=6) or deletion mutations (n=2). Never treated patients had lower plasma lyso-Gb3 and analogues at m/z (−28), (−2), (+16), (+34) and the seven urinary lyso-Gb3 analogues compared with pretreatment levels of the treated patients. A significant reduction of plasma lyso-Gb3 and five analogues, as well as urine Gb3 and six lyso-Gb3 analogues, but not lyso-Gb3 and lyso-Gb3 at m/z (+50), was observed post-treatment with agalsidase-beta. The same tendency was observed with agalsidase-alfa.

Conclusion

Women with Fabry disease who started treatment based on clinical manifestations had higher lyso-Gb3 and analogue biomarker levels than never treated women. This indicates that a biomarker cut-off could potentially be a decision tool for treatment initiation in women with Fabry disease.
Psychotherapy is still failing patients: revisiting informed consent—a response to Garson Leder
Authors: Blease Charlotte
Published: September 2020

Compared with mainstream medicine and complementary and alternative therapies, the practice of psychotherapy has enjoyed a relative pass when it comes to ethical evaluation. Therefore, contributions to the, although slowly growing, body of literature on psychotherapy ethics are to be welcomed. In his paper ‘Psychotherapy, placebos, and informed consent’, Garson Leder takes issue with what he calls the ‘go open’ project in psychotherapy ethics—the idea that the so-called ‘common factors’ in therapy should be disclosed to prospective patients. Although Leder does not give a detailed list, the common factors include therapist characteristics (empathy, positive regard, positive expectations that therapy will succeed), patient characteristics (expectations about therapy including its plausibility, confidence in the therapist), and the working alliance (how well both therapist and patient work well together during sessions). He argues that the project advocating disclosure of these factors is flawed on two grounds: (1) that information about common factors is not necessary for informed consent; and (2) clarity about specific mechanisms of change in therapy is consistent with ‘many theory-specific forms of psychotherapy’. There are multiple serious problems with Leder’s critique of the recent literature, including how he represents the contours of the debate, which I list, and address in this response.
Collision tumour of two nodal metastases (adenocarcinoma and mast cell tumour) in a dog
Authors: Gibson Danielle , Beck Samuel , Gonzàlez‐Gasch Esteban , Harper Aaron
Published: September 2020

An 11‐year‐old female neutered Labrador retriever was referred for a large vulvar mast cell tumour that extended into the vagina. Abdominal ultrasound revealed an enlarged right medial iliac lymph node, and cytology of the node was consistent with an endocrine/neuroendocrine tumour. An approximately 1.5‐cm right anal sac mass was palpated. Medial iliac lymphadenectomy via ventral celiotomy, right anal sacculectomy and marginal vulvar mass resection were performed. Histopathology was consistent with right anal sac adenocarcinoma, vulvar mast cell tumour, and the right medial iliac lymph node showed a metastatic collision of both the adenocarcinoma and mast cell tumour cell populations. Adjunctive chemotherapy and radiotherapy were recommended to address the risk of local recurrence and further metastasis but were declined by the owner. The dog remains alive and asymptomatic with no visible evidence of recurrence 14 months after initial presentation.
Effect of local cold application during exercise on gene expression related to mitochondrial homeostasis
Authors: Meister Ben , Collins Chris , McGlynn Mark , Slivka Dustin
Published: September 2020

Exercise training increases mitochondrial content in active skeletal muscle. Previous work suggests that mitochondrial-related genes respond favorably to exercise in cold environments. However, the impact of localized tissue cooling is unknown. The purpose of this study was to determine the impact of local muscle cooling during endurance exercise on human skeletal muscle mitochondrial-related gene expression. Twelve subjects (age, 28 ± 6 years) cycled at 65% peak power output. One leg was cooled (C) for 30 min before and during exercise with a thermal wrap while the other leg was wrapped but not cooled, room temperature (RT). Muscle biopsies were taken from each vastus lateralis before and 4 h after exercise for the analysis of gene expression. Muscle temperature was lower in the C (29.2 ± 0.7 °C) than the RT (34.1 ± 0.3 °C) condition after pre-cooling for 30 min before exercise (p < 0.001) and remained lower after exercise in the C (36.9 ± 0.5) than the RT (38.4 ± 0.2, p < 0.001) condition. PGC-1α and NRF1 mRNA expression were lower in the C (p = 0.012 and p = 0.045, respectively) than the RT condition at 4 h after exercise. There were no temperature-related differences in other genes (p > 0.05). These data suggest that local cooling has an inhibitory effect on exercise-induced PGC-1α and NRF1 expression in human skeletal muscle. Those considering using local cooling during exercise should consider other systemic cooling options.

Novelty: Local cooling has an inhibitory effect on exercise-induced PGC-1α and NRF1 expression in human skeletal muscle. Local cooling may lead to a less robust exercise stimulus compared with standard conditions.
Sea ice and snow phenology in the Canadian Arctic Archipelago from 1997 to 2018
Authors: Dauginis Alicia L.A. , Brown Laura C.
Published: September 2020

The multiple islands and narrow channels that form the Canadian Arctic Archipelago (CAA) complicate snow/ice monitoring, as coarse resolution satellite observations are unable to resolve smaller-scale changes in snow/ice cover. We present the first study showing the utility of the Interactive Multisensor Snow and Ice Mapping System (IMS) 24 km (1997–2018) and 4 km (2004–2018) products to investigate changes in sea ice and snow phenology together in the CAA. Although ice break-up and snow retreat are shifting earlier (p > 0.05), on par with other Arctic regions, the final summer clearing of ice is shifting later. This, combined with trends towards earlier ice freeze and snow fall (p < 0.05), result in shorter open water and snow free seasons in the CAA. Spatial links between sea ice and snow are evident as significant clusters of trends were identified for all phenology parameters. The western regions were dominated by shifts towards shorter snow/ice seasons, whereas eastern regions tended to exhibit longer cover. Our research highlights the considerable regional and interannual variability in the timing of sea ice and snow advance/retreat within the CAA and emphasizes how the ice and snow dynamics in this complex region are responding to ongoing changing climate conditions.
Shear modulus and hysteretic damping of sensitive eastern Canada clays
Authors: Abdellaziz Mustapha , Karray Mourad , Chekired Mohamed , Delisle Marie-Christine , Locat Pascal , Ledoux Catherine , Mompin Rémi
Published: September 2020

The shear modulus and hysteretic damping of three sensitive clays from the sediments of Champlain Sea were investigated using a combined triaxial simple shear apparatus. The tests were conducted on undisturbed samples and were carried out on a wide range of shear strains from about 0.001% to 1%. The values of the small-strain shear modulus of the tested clays were further confirmed through a series of piezoelectric ring actuator tests. Although the shear modulus and damping ratio of the sensitive eastern Canadian clays follow some classic literature models, the results show that the examined clays exhibited more linear behaviour. Such behaviour may be attributed to their highly structured nature compared to other clays. The compilation of available data on the shear modulus and damping ratio of several sensitive eastern Canadian clays confirmed this trend and showed that some literature models might not be representative.
Towards a simple and reliable method for calculating uplift capacity of plate anchors in sand
Authors: Roy A. , Chow S.H. , O’Loughlin C.D. , Randolph M.F.
Published: September 2020

This paper investigates the uplift capacity of horizontal plate anchors in sand through finite element analyses and centrifuge experiments. The finite element simulations adopt a sophisticated bounding surface plasticity model that accounts for stress- and density-dependent behaviour, as well as loading- and fabric-related anisotropic effects in sands. Failure mechanisms at peak anchor capacity show that failure occurs progressively, with a marked decrease in mobilised friction angle within the shear bands close to the anchor edge. Numerical simulations of a large set of centrifuge experiments on rectangular, strip, and circular plates at different relative densities and stress levels are in good agreement for dense conditions, but perform more poorly for loose conditions due mainly to the open cone yield surface in the bounding surface model. Equivalent comparisons with current limit equilibrium methods highlight the challenges in direct application of element-level strength equations. Finally, the paper proposes a modified limit equilibrium solution based on a “rigid-block” failure mechanism extending to the soil surface, but with anchor factors that encompass the results from the finite element simulations. The modified solution provides a higher level of agreement with results from a large database of plate and pipeline test data than existing limit equilibrium methods.
Effects of a low-thiamine diet on reproductive traits in three populations of Atlantic salmon targeted for reintroduction into Lake Ontario
Authors: Mitchell Kimberly T. , Garner Shawn R. , Houde Aimee Lee , Wilson Chris C. , Pitcher Trevor E. , Neff Bryan D.
Published: September 2020

Exotic prey fishes that have high thiaminase levels are associated with a thiamine deficiency and reduced fitness in many salmonids. If sensitivity to low thiamine availability differs among the three Atlantic salmon (Salmo salar) populations targeted for reintroduction into Lake Ontario, this could substantially influence their performance. We quantified the effects of a low-thiamine diet and a control diet on tissue thiamine concentrations, survival, growth rate, and reproductive traits (sperm and egg quality) in Atlantic salmon from the three candidate source populations. Fish that consumed the low-thiamine diet had comparable growth rates but lower survival and lower muscle thiamine concentrations (26 nmol·g–1) than control fish (34 nmol·g–1). Sperm count, velocity, motility, and longevity did not differ based on diet. Embryo survival was lower for females fed the low-thiamine diet, and the low-thiamine diet was associated with significantly lower egg thiamine concentrations (11 versus 17 nmol·g–1). The effects of the low-thiamine diet did not differ among the tested populations, which suggests that source population selection is unlikely to fully overcome this potential challenge for re-establishing wild populations.
Improvement of plant microbiome using inoculants for agricultural production: a sustainable approach for reducing fertilizer application
Authors: Sarpong Clement Kyei , Zhang Xiaofeng , Wang Qili , Wang Wenjing , Jamali Zameer Hussain , Yong Taiwen , Chang Xiaoli , Yang Wenyu , Wang Yu , Song Chun
Published: September 2020

The overuse of agrochemicals for agricultural productivity to meet the global food demand of the rapidly growing human population is a great environmental threat, particularly for aquatic ecosystems. Being associated intimately with plant health, growth, and productivity, the plant microbiome is emerging as a promising environmentally friendly and sustainable resource for agricultural productivity. For the past decades, our understanding of the interactions between plants and microorganisms and our knowledge of how to improve the plant microbiome by using microbial inoculants has increased significantly. A better understanding of the impact of the plant microbiome on mineral resources will benefit plant and soil health. In this review, we highlight the importance of microbial inoculants and their interactions with mineral fertilizers in enhancing crop productivity, as well as current challenges.
ENERGY INSECURITY IN THE ASEAN REGION: THE IMPLICATIONS OF ENERGY POLICY REFORM
Authors: RESOSUDARMO BUDY P. , NURDIANTO DITYA A. , EFFENDI YUVENTUS
Published: September 2020

Energy insecurity has become an alarming issue among ASEAN countries. One proposal to overcome this energy insecurity is to integrate energy markets among ASEAN countries. In order to do this integration, a major energy policy reform, particularly the elimination of energy subsidy policies, is needed. The main goal of this paper, hence, is to analyze the impact of an energy subsidy reduction policy in ASEAN, particularly in terms of economic growth, environmental improvement and welfare distribution. To achieve this goal, this paper uses a multi-country computable general equilibrium (CGE) for Inter-Regional System Analysis for ASEAN (IRSA-ASEAN) to conduct the analysis. This paper finds that countries in which energy subsidies significantly exist, i.e., Indonesia and Malaysia, stand to gain much from eliminating these subsidies. Gross domestic product (GDP) is likely to increase, with the added benefit of reduced CO2emissions. In terms of welfare distribution, this policy appears to be progressive in nature.
Cyclotron frequency in the quantum clock geometry
Authors: Mignemi S.
Published: September 2020

We discuss the corrections to the orbital period of a particle in a constant magnetic field, driven by the model of noncommutative geometry recently associated to a quantum clock. The effects are extremely small, but in principle detectable.
The Newtonian potential of a static Dirac spinor particle
Authors: Liu Yao-Yang , Sun La-Zhen
Published: September 2020

The gravitational theory including spinor particle is formulated with the suggestion of tetrad fields [Formula: see text] by Utiyama, Kibble and Weinberg.[Formula: see text] We might take the metric [Formula: see text] as a constraint, that is used the method of Lagrange multiplier. In the weak-field approximation we calculate the metric of a static Dirac spinor particle proton and obtain that the metric is a diagonal [Formula: see text] which coincides with the anticipative result of Newtonian Gravitational potential.
Quantum dynamics of a qutrit in a cavity filled with Kerr-like medium and intrinsic noise
Authors: Mohamed A.-B. A. , Elkhateeb M. M. , Hashem M. , Obada A.-S. F. , Eleuch H.
Published: September 2020

We study the dynamics of the intrinsic noise (IN) model of a three-level atom (qutrit) in V-configuration. The qutrit is inside an open cavity with a Kerr-like medium. The quantifiers of the atomic population, entanglement and mixedness are evaluated under the physical parameters of the photon multiplicity, IN and the nonlinearity of both the unitary interaction and the Kerr-like medium. It is found that the generated entanglement and mixedness may be enhanced by filling the cavity with a nonlinear medium. The transfer of the energy between the two upper states and the lower state are very sensitive to the physical parameters. The entanglement and mixedness depend on the initial coherent intensity, the IN and the Kerr-like medium.
Elliptic flow splitting between protons and antiprotons from hadronic potentials
Authors: Li Pengcheng , Wang Yongjia , Steinheimer Jan , Li Qingfeng , Zhang Hongfei
Published: September 2020

The difference in elliptic flow between protons and antiprotons, produced in [Formula: see text] collisions at center-of-mass energies [Formula: see text], is studied within a modified version of the ultra-relativistic quantum molecular dynamics (UrQMD) model. Two different model scenarios are compared: the cascade mode and the mean field mode which includes potential interactions for both formed and pre-formed hadrons. The model results for the elliptic flow of protons and the relative elliptic flow difference between protons and antiprotons obtained from the mean field mode agree with the available experimental data, while the elliptic flow difference is near zero for the cascade mode. Our results show that the elliptic flow splitting, observed for particles and antiparticles, can be explained by the inclusion of proper hadronic interactions. In addition, the difference in elliptic flow between protons and antiprotons depends on the centrality and the rapidity window. With smaller centrality and/or rapidity acceptance, the observed elliptic flow splitting is more sensitive to the beam energy, indicating a strong net baryon density dependence of the effect. We propose to confirm this splitting at the upcoming experiments from Beam Energy Scan (BES) Phase-II at Relativistic Heavy Ion Collider (RHIC), the Compressed Baryonic Matter (CBM) at Facility for Antiproton and Ion Research (FAIR), High Intensity heavy ion Accelerator Facility (HIAF) and Nuclotron-based Ion Collider fAcility (NICA).
Four-party quantum operation sharing with composite quantum channel in Bell and Yeo–Chua product state
Authors: Zhang Zhanjun , Xing Hang , Ye Biaoliang , Xie Chuanmei
Published: September 2020

A four-party single-qubit operation sharing scheme is put forward by utilizing the Bell and Yeo–Chua product state in an entanglement structure as the composite quantum channel. Four features of the scheme are discussed and confirmed, including its determinacy, symmetry, and security as well as the scheme experimental feasibility. Moreover, some concrete comparisons between our present scheme and a previous scheme [H. Xing et al., Quantum Inf. Process. 13 (2014) 1553] are made from the aspects of quantum and classical resource consumption, necessary operation complexity, and intrinsic efficiency. It is found that our present scheme is more superior than that one. In addition, the essential reason why the employed state in the entanglement structure is applicable for sharing an arbitrary single-qubit operation among four parties is revealed via deep analyses. With respect to the essential reason, the capacity of the product state in quantum operation sharing (QOS) is consequently shown by simple presenting the corresponding schemes with the state in other entanglement structures.
Vehicle Seat Detection Based on Improved RANSAC-SURF Algorithm
Authors: Li Xiaoguang , Zhu Juan , Ruan Yiming
Published: September 2020

In order to detect the type of vehicle seat and the missing part of the spring hook, this paper proposes an improved RANSAC-SURF method. First, the image is filtered by a Gauss filter. Second, an improved RANSAC-SURF algorithm is used to detect the types of vehicle seats. Extract the feature points of vehicle seats. The feature points are matched according to the improved RANSAC-SURF algorithm. Third, the image distortion of the vehicle seat is corrected by the method of perspective transformation. Determine whether the seat’s spring hook is missing or not according to the absolute value of the gray difference between the image collected by the camera and the image of the normal installation. The experimental results show that the MSE of the Gauss filter under a 5 [Formula: see text] 5 template is 19.0753, and the PSNR is 35.3261, which is better than that of the mean filter and the median filter. The total matching logarithm of feature points and the number of intersection points are 188 and 18, respectively, in the improved RANSAC-SURF matching algorithm.
Bifurcation Analysis and Pattern Selection of Solutions for the Modified Swift–Hohenberg Equation
Authors: Choi Yuncherl , Ha Taeyoung , Han Jongmin
Published: September 2020

In this paper, motivated by [Peletier & Rottschäfer, 2004; Peletier & Williams, 2007], we study the dynamical bifurcation of the modified Swift–Hohenberg equation endowed with an evenly periodic condition on the interval [Formula: see text]. As [Formula: see text] crosses over the critical points, the trivial solution bifurcates to an attractor and some new patterns of solutions emerge. We provide detailed descriptions of all possible final patterns of solutions on the overlapped intervals of [Formula: see text], which emerge after a gap collapses to a point. We also compute all critical values of [Formula: see text], [Formula: see text] and [Formula: see text] precisely, which are responsible for bifurcation and pattern formations. We finally provide numerical results that explain the main theorems.
Periodic Solutions of Continuous Third-Order Differential Equations with Piecewise Polynomial Nonlinearities
Authors: Llibre J. , Lopes B. D. , de Moraes J. R.
Published: September 2020

We consider third-order autonomous continuous piecewise differential equations in the variable [Formula: see text]. For such differential equations with nonlinearities of the form [Formula: see text], we investigate their periodic solutions using the averaging theory. We remark that since the differential system is only continuous we cannot apply to it the classical averaging theory, that needs that the differential system be at least of class [Formula: see text].
Effects of Low and High Neuron Activation Gradients on the Dynamics of a Simple 3D Hopfield Neural Network
Authors: Doubla Isaac Sami , Njitacke Z. Tabekoueng , Kengne J.
Published: September 2020

In this paper, the effects of low and fast response speeds of neuron activation gradient of a simple 3D Hopfield neural network are explored. It consists of analyzing the effects of low and high neuron activation gradients on the dynamics. By considering an imbalance of the neuron activation gradients, different electrical activities are induced in the network, which enable the occurrence of several nonlinear behaviors. The significant sensitivity of nontrivial equilibrium points to the activation gradients of the first and second neurons relative to that of the third neuron is reported. The dynamical analysis of the model is done in a wide range of the activation gradient of the second neuron. In this range, the model presents areas of periodic behavior, chaotic behavior and periodic window behavior through complex bifurcations. Interesting behaviors such as the coexistences of two, four, six and eight disconnected attractors, as well as the phenomenon of coexisting antimonotonicity, are reported. These singular results are obtained by using nonlinear dynamics analysis tools such as bifurcation diagrams and largest Lyapunov exponents, phase portraits, power spectra and basins of attraction. Finally, some analog results obtained from PSpice-based simulations further verify the numerical results.
Another New Chaotic System: Bifurcation and Chaos Control
Authors: Ray Arnob , Ghosh Dibakar
Published: September 2020

We propose a new simple three-dimensional continuous autonomous model with two nonlinear terms and observe the dynamical behavior with respect to system parameters. This system changes the stability of fixed point via Hopf bifurcation and then undergoes a cascade of period-doubling route to chaos. We analytically derive the first Lyapunov coefficient to investigate the nature of Hopf bifurcation. We investigate well-separated regions for different kinds of attractors in the two-dimensional parameter space. Next, we introduce a timescale ratio parameter and calculate the slow manifold using geometric singular perturbation theory. Finally, the chaotic state annihilates by decreasing the value of the timescale ratio parameter.
A New Type of Solitary Wave Solution of the mKdV Equation Under Singular Perturbations
Authors: Zhang Lijun , Han Maoan , Zhang Mingji , Khalique Chaudry Masood
Published: September 2020

In this work, we examine the solitary wave solutions of the mKdV equation with small singular perturbations. Our analysis is a combination of geometric singular perturbation theory and Melnikov’s method. Our result shows that two families of solitary wave solutions of mKdV equation, having arbitrary positive wave speeds and infinite boundary limits, persist for selected wave speeds after small singular perturbations. More importantly, a new type of solitary wave solution possessing both valley and peak, named as breather in physics, which corresponds to a big homoclinic loop of the associated dynamical system is observed. It reveals an exotic phenomenon and exhibits rich dynamics of the perturbed nonlinear wave equation. Numerical simulations are performed to further detect the wave speeds of the persistent solitary waves and the nontrivial one with both valley and peak.
On the Three-Dimensional Fractional-Order Hénon Map with Lorenz-Like Attractors
Authors: Khennaoui Amina-Aicha , Ouannas Adel , Odibat Zaid , Pham Viet-Thanh , Grassi Giuseppe
Published: September 2020

A three-dimensional (3D) Hénon map of fractional order is proposed in this paper. The dynamics of the suggested map are numerically illustrated for different fractional orders using phase plots and bifurcation diagrams. Lorenz-like attractors for the considered map are realized. Then, using the linear fractional-order systems stability criterion, a controller is proposed to globally stabilize the fractional-order Hénon map. Furthermore, synchronization control scheme has been designed to exhibit a synchronization behavior between a given 2D fractional-order chaotic map and the 3D fractional-order Hénon map. Numerical simulations are also performed to verify the main results of the study.
Stochastic Analysis of a Computer System with Unit Wise Cold Standby Redundancy and Priority to Hardware Repair Subject to Failure of Service Facility
Authors: Malik S. C. , Yadav R. K.
Published: September 2020

The use of semi-Markov process and regenerative point has been made for determining reliability measures of a computer system. The stochastic model is developed by considering the ideas of unit wise redundancy and failure of service facility. The treatment to the failed service facility is given in order to resume the jobs with full efficiency. The system is analyzed at different time points in the steady state. The profit of the system model has been obtained under the following two policies: In first policy, the profit is evaluated by taking cost per unit time for busy period of the service facility and cost per unit time treatment of the service facility. In second policy, the profit is evaluated by taking cost per unit hardware repair, per unit time software up-gradation and cost per unit time treatment of the service facility. The behavior of some reliability measures, such as MTSF, availability and profit function, has been shown graphically for arbitrary values of the parameters.
Synchronization by noise for the stochastic quantization equation in dimensions 2 and 3
Authors: Gess Benjamin , Tsatsoulis Pavlos
Published: September 2020

We prove uniform synchronization by noise with rates for the stochastic quantization equation in dimensions two and three. The proof relies on a combination of coming down from infinity estimates and the framework of order-preserving Markov semigroups derived in [O. Butkovsky and M. Scheutzow, Couplings via comparison principle and exponential ergodicity of SPDEs in the hypoelliptic setting, preprint (2019), arXiv:1907.03725]. In particular, it is shown that this framework can be applied to the case of state spaces given in terms of Hölder spaces of negative exponent.
Regularization Strategies for Contiguous and Noncontiguous Damage Detection of Structures
Authors: Luo Ziwei , Yu Ling
Published: September 2020

Regularization strategies have attracted attention in the structural damage detection (SDD) field. However, there is lack of studies on regularization strategies for damage patterns in the existing methods. This paper proposes regularization strategies for contiguous and noncontiguous damages of structures and performs comparative studies. The objective functions are first defined to consider effects of strategies on SDD by adding distinct norm penalties, and then are solved by the particle swarm optimization (PSO). Three numerical simulation models are employed to assess the applicability of three strategies. The results show that the [Formula: see text] norm regularization is suitable for detecting multiple damages, the [Formula: see text] norm regularization performs well in contiguous damages, and the sparsest solutions can be obtained by the [Formula: see text] norm regularization.
A Hybrid Fundamental-Solution-Based Finite Element Method for Transient Heat Conduction Analysis of Two-Dimensional Orthotropic Materials
Authors: Liu Huan , Wang Keyong , Liu Qing , Li Peichao
Published: September 2020

A new hybrid fundamental-solution-based finite element method (HFS-FEM) is developed for the transient heat conduction analysis of two-dimensional orthotropic materials. By using coordinate transformation and time-stepping approximation, the governing equation of the original problem is converted to the modified Helmholtz equation. In the solution procedure, the homogeneous solutions of the problem are sought by employing HFS-FEM while the particular solutions are approximated with the aid of radial basis function. HFS-FEM has many attractive features compared to the conventional FEM. The computational efficiency and convergence of the present method are examined through several numerical examples.
Overlapping Multi-Domain Spectral Method for MHD Mixed Convection Slip Flow Over an Exponentially Decreasing Mainstream with Nonuniform Heat Source/Sink and Convective Boundary Conditions
Authors: Mkhatshwa Musawenkhosi P. , Motsa Sandile S. , Sibanda Precious
Published: September 2020

Overlapping multi-domain bivariate spectral quasilinearization method is applied on magnetohydrodynamic mixed convection slip flow over an exponentially decreasing mainstream with convective boundary conditions and nonuniform heat source/sink effects. The method is employed in solving the transformed flow equations. The convergence properties and accuracy of the method are determined. The method gives highly accurate results after few iterations and using few grid points in each space subinterval and the entire interval. The use of minimal numbers of grid points at each subinterval minimizes the effects of round-off errors that can lead to instabilities. The accuracy increases as the number of overlapping subintervals increases. The accuracy improvement is achieved through making the coefficient matrices less dense. The effects of controlling parameters on the flow fields and physical quantities of interest are studied. Results show that increasing Biot number and nonuniform heat source/sink enhances the flow fields while reducing skin friction and heat transfer rate. The fluid properties improve with injection whereas the flow characteristics augment with suction. The considered exponentially decreasing external flows have particular applications in diverging channel flows. This study has practical significance in various boundary layer problems such as in controlling and delaying boundary layer separation on control surfaces and in suppressing recirculating bubbles.
Lehmer’s problem for arbitrary groups
Authors: Lück W.
Published: September 2020

We consider the problem whether for a group [Formula: see text] there exists a constant [Formula: see text] such that for any [Formula: see text]-matrix [Formula: see text] over the integral group ring [Formula: see text] the Fuglede–Kadison determinant of the [Formula: see text]-equivariant bounded operator [Formula: see text] given by right multiplication with [Formula: see text] is either one or greater or equal to [Formula: see text]. If [Formula: see text] is the infinite cyclic group and we consider only [Formula: see text], this is precisely Lehmer’s problem.
Unconventional Monetary Policy and a Financial Intermediary: Were they Relevant to Fluctuations in the Japanese Economy?
Authors: Zhang Siyu
Published: September 2020

In this paper, we study whether the implementation of unconventional monetary policy (UMP) in Japan is relevant to its economy fluctuations. We conducted a Bayesian estimation of a DSGE model with an endogenous financial intermediary, and the central bank in the model is allowed to conduct a credit policy. Our findings can be summarized in the following three points: first, we find that the estimated posterior distribution of model parameters and the impulse response provide a plausible interpretation of the data. Second, by shock decomposition, we find that the credit supply shock of the bank sector played a crucial role in the GDP and investment fluctuations in the sample period. Third, the estimated risk spread reveals a high degree of correlation to the actual credit spread in Japan. Our estimation results suggest that UMP in Japan is effective in the sense of narrowing credit spreads, which leads to subsequent increase in investment and, in turn, positively affects the economy.
A Short Survey on Green’s Function for Acoustic Problems
Authors: Okoyenta Augustus R. , Wu Haijun , Liu Xueliang , Jiang Weikang
Published: September 2020

Green’s functions for acoustic problems is the fundamental solution to the inhomogeneous Helmholtz equation for a point source, which satisfies specific boundary conditions. It is very significant for the integral equation and also serves as the impulse response of an acoustic wave equation. They are important for acoustic problems that involve the propagation of sound from the source point to the observer position. Once the Green’s function, which satisfies the necessary boundary conditions, is obtained, the sound pressure at any point away from the source can be easily calculated by the integral equation. The major problem faced by researchers is in the process of constructing these Green’s functions which satisfy a specific boundary condition. The aim of this work is to review some of these fundamental solutions available in the literature for different boundary conditions for the ease of analyzing acoustics problems. The review covers the free-space Green’s functions for stationary source and rotational source, for both when the observer and the acoustic medium are at rest and when the medium is in uniform flow. The half-space Green’s functions are also summarized for both stationary acoustic source and moving acoustic source, derived using the image source method, equivalent source method and complex equivalent method in both time domain and frequency domain. Each of these methods used depends on the different impedance boundary conditions for which the Green’s function will satisfy. Finally, enclosed spaced Green’s functions for both rectangular duct and cylindrical duct for an infinite and finite duct is also covered in the review.
Geodynamic context of the Proterozoïc deposits of the Firgoun Region (eastern border of the West African Craton, West Niger)
Authors: Alzouma Amadou Diafarou , Konaté Moussa , Ahmed Yacouba
Published: September 2020

In the Firgoun region located on the southwestern part of Niger, Proterozoic sedimentary deposits mark the southeastern edge of the West African Craton. The lowermost coarse-grained sandstones, structureless, are related to fluviatile deposits. They evolve vertically to alternating quartzitic sandstone beds and silty–clayey sandstone layers, interpreted as a shallow marine turbiditic sequence. The uppermost deposits have glacial features comparable with those found in Gourma and Taoudenni basins. These are diamictites interbeddeds–carbonates–silexites and cryoturbation features in slates, attributed to the association of ‘tillite
–
limestone
–
chert’ related to the ‘triad’. The Firgoun area deposits, as with their equivalents of Gourma and Béli basins, have recorded the Pan-African deformation episodes. In this paper we show that the studied deposits were firstly affected by an early distensive phase D1 and secondly by two Pan-African compressive episodes D2a and D2b. The distensive deformation episode is well recorded in the basal deposits (‘Sandstone of Firgoun Formation’). The deformation structures correspond to 70–80° N trending, syn-depositional normal faults. The plotting of the faults planes onto the stereographic diagram shows the prevailing of the extensional regime marked by a 140° N trending stretching. The first compressive deformation stage D2a is characterized in the basal deposits by isopachous folds and by anisopachous folds in the uppermost deposits. The combination of the satellite image and the plotting of the fold axial planes (30° N–45° NE to 50° N–50° NE) onto the stereographic diagram indicate a compressive regime with 120–140° N trending shortening. The last compressive deformation stage D2b is marked by thrust and reverse fault planes oriented 60–80° N, crosscutting all of the previous structures, mainly observed in the uppermost deposits (‘Béli–Garous Formation’). Their plotting onto the stereographic diagram reveals a 40° N shortening direction.
Neural Network-based Inherently Fault-tolerant Hardware Cryptographic Primitives without Explicit Redundancy Checks
Authors: Alam Manaar , Bag Arnab , Roy Debapriya Basu , Jap Dirmanto , Breier Jakub , Bhasin Shivam , Mukhopadhyay Debdeep
Published: September 2020

Fault injection-based cryptanalysis is one of the most powerful practical threats to modern cryptographic primitives. Popular countermeasures to such fault-based attacks generally use some form of redundant computation to detect and react/correct the injected faults. However, such countermeasures are shown to be vulnerable to selective fault injections. In this article, we aim to develop a cryptographic primitive that is
fault tolerant by its construction
and does not require to compute the same value multiple times. We utilize the effectiveness of Neural Networks (NNs), which show “some degree” of robustness by functioning correctly even after the occurrence of faults in any of its parameters. We also propose a novel strategy that enhances the fault tolerance of the implementation to “high degree” (close to 100%) by incorporating selective constraints in the NN parameters during the training phase. We evaluated the performance of revised NN considering both software and FPGA implementations for standard cryptographic primitives like 8×8 AES SBox and 4×4 PRESENT SBox. The results show that the fault tolerance of such implementations can be significantly increased with the proposed methodology. Such NN-based cryptographic primitives will provide inherent resistance against fault injections without requiring any redundancy countermeasures.
Toward a Criminology of Sexual Harassment
Authors: Uggen Christopher , Powers Ráchael A. , McLaughlin Heather , Blackstone Amy
Published: September 2020

Public attention to sexual harassment has increased sharply with the rise of the #MeToo movement, although the phenomenon has sustained strong scientific and policy interest for almost 50 years. A large and impressive interdisciplinary scholarly literature has emerged over this period, yet the criminology of sexual harassment has been slow to develop. This review considers how criminological theory and research can advance knowledge on sexual harassment—and how theory and research on sexual harassment can advance criminological knowledge. We review classic and contemporary studies and highlight points of engagement in these literatures, particularly regarding life-course research and violence against women. After outlining prospects for a criminology of sexual harassment that more squarely addresses perpetrators as well as victims, we discuss how criminological insights might contribute to policy efforts directed toward prevention and control.
Statistical Properties of Subgrid-Scale Turbulence Models
Authors: Moser Robert D. , Haering Sigfried W. , Yalla Gopal R.
Published: September 2020

This review examines large eddy simulation (LES) models from the perspective of their a priori statistical characteristics. The most well-known statistical characteristic of an LES subgrid-scale model is its dissipation (energy transfer to unresolved scales), and many models are directly or indirectly formulated and tuned for consistency of this characteristic. However, in complex turbulent flows, many other subgrid statistical characteristics are important. These include such quantities as mean subgrid stress, subgrid transport of resolved Reynolds stress, and dissipation anisotropy. Also important are the statistical characteristics of models that account for filters that do not commute with differentiation and of the discrete numerical operators in the LES equations. We review the known statistical characteristics of subgrid models to assess these characteristics and the importance of their a priori consistency. We hope that this analysis will be helpful in continued development of LES models.