bluuebunny/crossref_metadata_2025 huggingface dataset:
Amplitude Nonlinear Normal Modes of Piecewise Linear Systems
Authors: Jiang Dongying , Soumier Vincent , Pierre Christophe , Shaw Steven W.
Published: November 2020

A numerical method for constructing nonlinear normal modes for piecewise linear autonomous systems is presented. Based on the concept of invariant manifolds, a Galerkin based approach is applied here to obtain nonlinear normal modes numerically. The accuracy of the constructed nonlinear modes is checked by the comparison of the motion on the invariant manifold to the exact solution, in both time and frequency domains. It is found that the Galerkin based construction approach can represent the invariant manifold accurately over strong nonlinearity regions. Several interesting dynamic characteristics of the nonlinear modal motion are found and compared to those of linear modes. The stability of the nonlinear normal modes of a two-degree of freedom system is investigated using characteristic multipliers and Poincaré maps, and a flip bifurcation is found for both nonlinear modes.
Analysis of Periodic Frictional Contact in Finite Elements Problems
Authors: Nacivet Samuel , Pierre Christophe , Thouverez Fabrice , Jezequel Louis
Published: November 2020

This paper considers the dynamics of structural systems modeled using the finite element method and subject to dry friction damping, using Coulomb’s law for the friction force model. A new frequency-time domain method, the Dynamic Lagrangian mixed Frequency-Time method (DLFT), is developed to calculate the steady-state forced response. The dynamic Lagrangians formulation introduced herein, when used in conjunction with a nonlinear solver in the frequency domain, is better suited to handling dry friction nonlinearities than the traditional augmented Lagrangians method. Namely, the use of dynamic Lagrangians allows one to solve for the nonlinear forces between two finite element nodes of the structure without using artifacts such as a spring. Hence the finite element model does not have to be degraded at the contact interface. Furthermore, a new reduction of the nonlinear system is proposed to decrease the required computation time. Finally, a set of numerical examples is presented for a beam in contact with a flexible dry friction element connected to ground, for frictional constraints that feature two-dimensional relative motion, and for a large-scale structural system with many friction dampers.
Newtonian and Variational Formulations of the Vibrations of Plates With Active Constrained Layer Damping
Authors: Park Chul H. , Baz A.
Published: November 2020

This paper presents Newtonian and variational formulations of the dynamics of plates treated fully with Active Constrained Layer Damping (ACLD). The developed equations of the plate/ACLD system provide analytical models for predicting the dynamic of laminated plates subjected to passive and active vibration damping controls. Numerical solutions of the analytical models are presented for simply-supported plates in order to study the performance of the plate/ACLD system for different control strategies. The developed models present invaluable means for designing and predicting the performance of the smart laminated plates that can be used in many critical engineering applications.
A Model to Evaluate the Aerodynamic Energy Requirements of Active Materials in Morphing Wings
Authors: Pettit Gregory W. , Robertshaw Harry H. , Gern Frank H. , Inman Daniel J.
Published: November 2020

A computational model is presented which predicts the force, stroke, and energy needed to overcome aerodynamic loads encountered by morphing wings during aircraft maneuvers. This low-cost model generates wing section shapes needed to follow a desired flight path, computes the resulting aerodynamic forces using a unique combination of conformal mapping and the vortex panel method, computes the longitudinal motion of the simulated aircraft, and closes the loop with a zero-error control law. The aerodynamic force prediction method has been verified against two more expensive codes. This overall model will be used to predict the performance of morphing wings and the requirements for the active material actuators in the wings.
Development and Implementation of Adaptive Order Analysis in the Application of Multiaxial Systems
Authors: Pan Min-chun , Chen Jeng-xing
Published: November 2020

This study investigates the varying-order analysis based on mechanism, and realizes it in dynamic signal processing of rotary machinery. Firstly, the synthetic signatures consisting of fixed-order, varying-order components and resonance-related ones as well are designed to validate the developed computation schemes. Secondly, this work takes an electrical scooter as a test bench, which some experiments have been conducted on. The noise and vibration signatures are measured and processed to characterize different spectral components and identify their sources. Some of the annoying ones belong to fixed order (e.g., gear whine noise), varying order (e.g., CVT-belt noise) and structure resonance (e.g., the structure-borne noise originated from the CVT housing). Therefore, the concerned noise/vibration can subsequently be coped with via machine component modification.
Nonlinear Analysis of Rotor Systems Including a Bearing Clearance by the Multiple Shooting Method
Authors: Demailly David , Thouverez Fabrice , Jézéquel Louis , Bonini Jérôme
Published: November 2020

In this paper the Multiple Shooting Method is briefly exposed. This method is then applied to a simplified model of a rotor/stator system including a bearing with clearance under static and unbalance forces. With bearing having a small amount of clearance, it is pointed out that the orbits are no longer circular at certain frequencies as for linear systems. If the clearance is large, the frequency response curve can be divided into three zones: a non-contact zone, a zone with one or several gains and looses of contact per period and a full contact zone. For both cases we emphasize on the evolution of the orbits while passing through transition zones.
Dynamic Polytope Function and Control Modeling
Authors: Wang Du , Guo Zhongyang , Hagiwara Ichiro
Published: November 2020

This study is motivated from the investigation of vehicle suspension system with changeable damping and variant stiffness parameters. Such suspension system can be modeled as a dynamic polytope based on the mapping of affinely changed parameters. According to the polytopic dynamics decomposition, knowledge of linear time invariant system can be applied to each polytope vertex and the time variant system is solved by the polytope convex synthesis method. For time variant vehicle suspension system, the different model structures for control purposes are formulated. A quarter-car is taken as the example for demonstration in observer design and nonlinear control design.
Investigations of internal stresses in high-voltage devices with deep trenches
Authors: Hieckmann Ellen , Mühle Uwe , Chekhonin Paul , Zschech Ehrenfried , Gambino Jeff
Published: November 2020

Deep trenches, as essential elements of silicon chips used in electronic high-power and high-frequency devices, are known as starting points for dislocation generation under the influence of internal mechanical stresses resulting mainly from the difference in the thermal expansion coefficients between silicon and silicon dioxide. Since the electrical insulation of the devices requires a sequence of mechanical, chemical, and high-temperature processes during the preparation of the deep trenches, including the formation of an amorphous SiO2 edge layer, the emergence of the internal stresses is hardly avoidable. The method of cross correlation backscattered electron diffraction in the scanning electron microscope is used here to quantitatively determine the magnitude and local distribution of internal stresses in silicon around the deep trenches after four different process steps. For this purpose, Kikuchi diffraction images are recorded of the wafer cross section areas along lines perpendicular and parallel to the deep trenches. After Fourier transformation, these images are cross correlated with the Fourier transform of the diffraction image from a stressfree reference sample site. The well-established numerical evaluation of cross correlation functions provides the complete distortion tensor for each measuring point of the line scan, from which the stress tensor can be calculated using Hooke's law. It is found that the in-plane normal stress component σ11 perpendicular to the long edges of the deep trench is larger than the other stress components. That means it essentially determines the magnitude of the von-Mises stress, which was determined as a general stress indicator for all measuring points, too. A characteristic feature is the local distribution of the stress component σ11 with maximum tensile stresses of some hundred megapascals at transition between Si and amorphous SiO2 on the long edges of the deep trench, and with even higher maximum compressive stresses immediately below the bottom of the deep trench. At a distance of about 2 μm from the edges of a single deep trench, all stress components decrease to negligibly small values so that steep stress gradients occur. The range and distribution of tensile and compressive stresses are in accordance with finite element simulations; however, the measured stresses are higher than expected for all investigated states so that dislocation formation seems to be possible. The influence of the electron acceleration voltage on the determination of the internal stresses is discussed as well.
Genomic Characterization of Emerging Bacterial Uropathogen Neisseria meningitidis, Which Was Misidentified as Neisseria gonorrhoeae by Nucleic Acid Amplification Testing
Authors: Sukhum Kimberley V. , Jean Sophonie , Wallace Meghan , Anderson Neil , Burnham Carey-Ann D. , Dantas Gautam
Published: November 2020

Neisseria meningitidis
and
Neisseria gonorrhoeae
are pathogenic bacteria that can cause human infections. While
N. meningitidis
infections are associated with bacterial meningitis and bacteremia, a strain of
N. meningitidis
, isolated from the urogenital system, has recently been associated with urethritis.
Determination of Genomic Epidemiology of Historical Clostridium perfringens Outbreaks in New York State by Use of Two Web-Based Platforms: National Center for Biotechnology Information Pathogen Detection and FDA GalaxyTrakr
Authors: Carey Jaclyn , Cole Jocelyn , Venkata Sai Laxmi Gubbala , Hoyt Hannah , Mingle Lisa , Nicholas David , Musser Kimberlee A. , Wolfgang William J.
Published: November 2020

Clostridium perfringens
is the second leading cause of bacterial foodborne illness in the United States. The Wadsworth Center (WC) at the New York State Department of Health enumerates infectious dose from primary patient and food samples and, until recently, identified
C. perfringens
to the species level only.
Deeply Sequenced Infectious Clones of Key Cassava Begomovirus Isolates from Cameroon
Authors: Hoyer J. Steen , Fondong Vincent N. , Dallas Mary M. , Aimone Catherine Doyle , Deppong David O. , Duffy Siobain , Hanley-Bowdoin Linda
Published: November 2020

We deeply sequenced two pairs of widely used infectious clones (4 plasmids) of the bipartite begomoviruses African cassava mosaic virus (ACMV) and East African cassava mosaic Cameroon virus (EACMCV). The ACMV clones were quite divergent from published sequences. Raw reads, consensus plasmid sequences, and the infectious clones themselves are all publicly available.
Metagenomic Analysis of the Microbial Diversity in Solid Waste from Okhla Landfill, New Delhi, India
Authors: Yadav Bindu , Johri Atul Kumar , Dua Meenakshi
Published: November 2020

The Okhla landfill site is consistently in the news for pollution levels higher than the city average. Here, we report the taxonomic and functional characterization of the microbial diversity of Okhla landfill solid waste. The metagenome analyses revealed the microbial and metabolic diversity of the site.
Complete Genome Sequence of a Canadian Klebsiella michiganensis Strain, Obtained Using Oxford Nanopore Technologies Sequencing
Authors: Kang Mingsong , Chmara John , Duceppe Marc-Olivier , Phipps-Todd Beverley , Huang Hongsheng
Published: November 2020

Klebsiella michiganensis
is a Gram-negative opportunistic pathogen that is associated with many hospital-acquired infections in humans. Here, we report the complete genome sequence of a
K. michiganensis
strain isolated from a Canadian wastewater treatment facility.
Stressors and support system among parents of neonates hospitalised with systemic infections: qualitative study in South India
Authors: Murthy Shruti , Guddattu Vasudeva , Lewis Leslie , Nair Narayanapillai Sreekumaran , Haisma Hinke , Bailey Ajay
Published: November 2020

Objective

To explore stressors and support system for families with a neonate admitted with a systemic infection.

Design

Qualitative study using in-depth interviews (IDIs), based on principles of grounded theory.

Setting

A busy level III neonatal unit of a tertiary care teaching hospital in coastal Karnataka, India, between May 2018 and January 2019.

Participants

Parents and accompanying attendants of neonates admitted to the neonatal unit with one or more systemic infections.

Methods

Using purposive sampling, semi-structured IDIs were audio recorded, transcribed verbatim and a thematic analysis was performed.

Results

Thirty-eight participants were interviewed, lasting between 30 and 59 min. Babies’ hospitalisation with sepsis was an unprecedented, sudden and overwhelming event. Stressors related to uncertainties due to the information gap inherent to the nature of illness, cultural rituals, financial constraints, barriers to bonding and others. Parents reported experiencing insomnia, gastric disturbances and fatigue. Support (emotional and/or financial) was sought from families and friends, peers, staff and religion. Availability and preference of emotional support system differed for mothers and fathers. In our context, families, peers and religion were of particular importance for reinforcing the available support system. Participant responses were shaped by clinical, cultural, financial, religious and health service contexts.

Conclusion

Designing a family-centred care in our context needs consideration of stressors that extend beyond the immediate neonatal intensive care unit environment and interactions. Understanding the influence of the nature of illness, financial, familial and cultural contexts helps identify the families who are particularly vulnerable to stress.
ATF4 activation promotes hepatic mitochondrial dysfunction by repressing NRF1–TFAM signalling in alcoholic steatohepatitis
Authors: Hao Liuyi , Zhong Wei , Dong Haibo , Guo Wei , Sun Xinguo , Zhang Wenliang , Yue Ruichao , Li Tianjiao , Griffiths Alexandra , Ahmadi Ali Reza , Sun Zhaoli , Song Zhenyuan , Zhou Zhanxiang
Published: November 2020

Objective

Mitochondrial dysfunction plays a dominant role in the pathogenesis of alcoholic liver disease (ALD); however, the underlying mechanisms remain to be fully understood. We previously found that hepatic activating transcription factor 4 (ATF4) activation was associated with mitochondrial dysfunction in ALD. This study aimed to investigate the function and mechanism of ATF4 in alcohol-induced hepatic mitochondrial dysfunction.

Design

ATF4 activation was detected in the livers of patients with severe alcoholic hepatitis (AH). The role of ATF4 and mitochondrial transcription factor A (TFAM) in alcohol-induced liver damage was determined in hepatocyte-specific ATF4 knockout mice and liver-specific TFAM overexpression mice, respectively.

Results

Hepatic PERK-eIF2α-ATF4 ER stress signalling was upregulated in patients with AH. Hepatocyte-specific ablation of ATF4 in mice ameliorated alcohol-induced steatohepatitis. ATF4 ablation also attenuated alcohol-impaired mitochondrial biogenesis and respiratory function along with the restoration of TFAM. Cell studies confirmed that TFAM expression was negatively regulated by ATF4. TFAM silencing in hepatoma cells abrogated the protective effects of ATF4 knockdown on ethanol-mediated mitochondrial dysfunction and cell death. Moreover, hepatocyte-specific TFAM overexpression in mice attenuated alcohol-induced mitochondrial dysfunction and liver damage. Mechanistic studies revealed that ATF4 repressed the transcription activity of nuclear respiratory factor 1 (NRF1), a key regulator of TFAM, through binding to its promoter region. Clinical relevance among ATF4 activation, NRF1–TFAM pathway disruption and mitochondrial dysfunction was validated in the livers of patients with AH.

Conclusion

This study demonstrates that hepatic ATF4 plays a pathological role in alcohol-induced mitochondrial dysfunction and liver injury by disrupting the NRF1–TFAM pathway.
TDP-43 proteinopathies: a new wave of neurodegenerative diseases
Authors: de Boer Eva Maria Johanna , Orie Viyanti K , Williams Timothy , Baker Mark R , De Oliveira Hugo M , Polvikoski Tuomo , Silsby Matthew , Menon Parvathi , van den Bos Mehdi , Halliday Glenda M , van den Berg Leonard H , Van Den Bosch Ludo , van Damme Philip , Kiernan Matthew C , van Es Michael A , Vucic Steve
Published: November 2020

Inclusions of pathogenic deposits containing TAR DNA-binding protein 43 (TDP-43) are evident in the brain and spinal cord of patients that present across a spectrum of neurodegenerative diseases. For instance, the majority of patients with sporadic amyotrophic lateral sclerosis (up to 97%) and a substantial proportion of patients with frontotemporal lobar degeneration (~45%) exhibit TDP-43 positive neuronal inclusions, suggesting a role for this protein in disease pathogenesis. In addition, TDP-43 inclusions are evident in familial ALS phenotypes linked to multiple gene mutations including the TDP-43 gene coding (TARDBP) and unrelated genes (eg,C9orf72). While TDP-43 is an essential RNA/DNA binding protein critical for RNA-related metabolism, determining the pathophysiological mechanisms through which TDP-43 mediates neurodegeneration appears complex, and unravelling these molecular processes seems critical for the development of effective therapies. This review highlights the key physiological functions of the TDP-43 protein, while considering an expanding spectrum of neurodegenerative diseases associated with pathogenic TDP-43 deposition, and dissecting key molecular pathways through which TDP-43 may mediate neurodegeneration.
Pilot training and surgical education: flying towards a brighter future
Authors: Ahmed Hanad , Scott Alexander
Published: November 2020

Aim

Human factors, surgery and aviation are intimately tied together by the common threads of error, risk and interpersonal relationships. A plethora of research abounds in all disciplines individually. The lessons learnt in one domain however are not unique and can be shared between all to promote best practice, further research and a greater understanding at a fundamental level.

Methods

A structured, thematic, literature review was performed. PubMed, EMBASE and Ovid MEDLINE databases were interrogated directly. The Health Foundation, National Health Service and Department of Health online databases were used through querying intrinsic search functions.

Results

With expanding use of technologies such as checklists, there is a gap left to better address and understand the nuances and roles of stress, communication and emotion on both learning and clinical practice. These can be prominent in the high-pressure environments shared between aviation and surgery.

Conclusions

The authors explore lessons learnt from aviation, the human factors applicable to both and how they can be extrapolated to improve patient safety outcomes and promote the use of the ‘Software, Hardware, Environment, Liveware’ tool to aid practice.
Trace metal biogeochemical responses following wood ash addition in a northern hardwood forest
Authors: Deighton Holly D. , Watmough Shaun A. , Basiliko Nathan , Hazlett Paul W. , Reid Carolyn R. , Gorgolewski Adam
Published: November 2020

Wood ash may be useful as a forest soil amendment in Canada, but trace metals can have detrimental effects if they accumulate in, or are transported from, forest ecosystems. Metal concentrations in soil water and sugar maple (Acer saccharum Marsh.) seedling tissue chemistry were measured in a north temperate hardwood forest over 4 years following a biomass boiler ash addition field trial. Twenty plots (3 m × 3 m) were established in Haliburton Forest with both fly and bottom ash treatments of 0, 4, and 8 Mg·ha−1 with four replicates, and tension lysimeters were positioned in each plot at 30, 50, and 100 cm depths. Over the 4 years, soil water metal concentrations in treated plots were not significantly different from those of the control plots. No differences in metal concentrations in foliage of sugar maple seedlings could be detected, but there were significantly higher concentrations of some metals (Al, Fe, Zn, Pb, Ni, and Sr) in roots of treated plots. Simulated drought mobilized several metals in upper mineral soil, but this mobilization occurred similarly in controls and ash-treated soils. These results suggest that doses below 8 Mg·ha−1 industrial wood ash with trace metal concentrations below Canadian regulatory limits do not cause an increase in trace metal mobility or availability in northern hardwood forests with acidic soils during the first 5 years after application.
Comparison and analysis of optical properties between vertical and inclined GaAs nanostructures
Authors: Sun Yan , Liu Lei , Lv Zhisheng , Zhangyang Xingyue , Lu Feifei , Tian Jian
Published: November 2020

In this paper, COMSOL multi-physics field commercial software was used to design the simulation model of GaAs nanostructures array (vertical nanoholes, vertical nanowires, inclined nanoholes and inclined nanowires), and the changes of light absorption of these structures in the wavelength range of 200–840 nm were studied. The electric field distribution, carrier distribution and quantum efficiency of nanostructures are calculated and analyzed under certain structural parameters. The results show that the light absorption performance of nanowire structure in the short-wave region is better than that of the nanoholes structure. With a certain inclined angle, the inclined nanowire structure has a stronger light capture ability than the vertical nanowire structure, and the light absorption of nanowire structure has a minimum value at the 550 nm wavelength.
Higher-order homotopy perturbation method for conservative nonlinear oscillators generally and microelectromechanical systems’ oscillators particularly
Authors: Anjum Naveed , He Ji-Huan
Published: November 2020

A modification of the homotopy perturbation method is proposed by taking advantage of the enhanced perturbation method and the parameter expanding technology. A generalized oscillatory equation and some nonlinear oscillators as the special cases of this equation are considered as examples to outline the basic properties of the modification, and the result is of high accuracy.
Two synthetical five-component nonlinear integrable systems: Darboux transformations and applications
Authors: Chen Xin , Zha Qi-Lao
Published: November 2020

A generalized [Formula: see text] matrix spectral problem is investigated to generate two five-component nonlinear integrable systems, which involve an arbitrary smooth function. These systems are proven integrable in the sense of Lax pair. As the reduction cases, a four-component reaction diffusion equation and a four-component modified Korteweg-de Vries (mKdV) equation are solved by Darboux transformation approach.
SARS-CoV-2: influence of phosphate and magnesium, moderated by vitamin D, on energy (ATP) metabolism and on severity of COVID-19
Authors: van Kempen Theo A. T. G. , Deixler Elisabeth
Published: November 2020

The use of vitamin D to reduce the severity of COVID-19 complications is receiving considerable attention, backed by encouraging data. Its purported mode of action is as an immune modulator. Vitamin D, however, also affects the metabolism of phosphate and Mg, which may well play a critical role in SARS-CoV-2 pathogenesis. SARS-CoV-2 may induce a cytokine storm that drains ATP whose regeneration requires phosphate and Mg. These minerals, however, are often deficient in conditions that predispose people to severe COVID-19, including older age (especially males), diabetes, obesity, and usage of diuretics. Symptoms observed in severe COVID-19 also fit well with those seen in classical hypophosphatemia and hypomagnesemia, such as thrombocytopenia, coagulopathy, dysfunction of liver and kidneys, neurologic disturbances, immunodeficiency, failure of heart and lungs, delayed weaning from a respirator, cardiac arrhythmia, seizures, and, finally, multiorgan failure. Deficiencies of phosphate and Mg can be amplified by kidney problems commonly observed in patients with COVID-19 resulting in their wastage into urine. Available data show that phosphate and Mg are deficient in COVID-19, with phosphate showing a remarkable correlation with its severity. In one experiment, patients with COVID-19 were supplemented with a cocktail of vitamin D3, Mg, and vitamin B12, with very encouraging results. We, thus, argue that patients with COVID-19 should be monitored and treated for phosphate and Mg deficiencies, ideally already in the early phases of infection. Supplementation of phosphate and Mg combined with vitamin D could also be implemented as a preventative strategy in populations at risk.
Gut bioengineering strategies for regenerative medicine
Authors: O’Neill John D. , Pinezich Meghan R. , Guenthart Brandon A. , Vunjak-Novakovic Gordana
Published: November 2020

Gastrointestinal disease burden continues to rise in the United States and worldwide. The development of bioengineering strategies to model gut injury or disease and to reestablish functional gut tissue could expand therapeutic options and improve clinical outcomes. Current approaches leverage a rapidly evolving gut bioengineering toolkit aimed at 1) de novo generation of gutlike tissues at multiple scales for microtissue models or implantable grafts and 2) regeneration of functional gut in vivo. Although significant progress has been made in intestinal organoid cultures and engineered tissues, development of predictive in vitro models and effective regenerative therapies remains challenging. In this review, we survey emerging bioengineering tools and recent methodological advances to identify current challenges and future opportunities in gut bioengineering for disease modeling and regenerative medicine.
Why new biology must be uncovered to advance therapeutic strategies for chronic obstructive pulmonary disease
Authors: Nguyen Jennifer M. K. , Robinson Douglas N. , Sidhaye Venkataramana K.
Published: November 2020

Chronic obstructive pulmonary disease (COPD) is characterized by the destruction of alveolar tissue (in emphysema) and airway remodeling (leading to chronic bronchitis), which cause difficulties in breathing. It is a growing public health concern with few therapeutic options that can reverse disease progression or mortality. This is in part because current treatments mainly focus on ameliorating symptoms induced by inflammatory pathways as opposed to curing disease. Hence, emerging research focused on upstream pathways are likely to be beneficial in the development of efficient therapeutics to address the root causes of disease. Some of these pathways include mitochondrial function, cytoskeletal structure and maintenance, and airway hydration, which are all affected by toxins that contribute to COPD. Because of the complexity of COPD and unknown targets for disease onset, simpler model organisms have proved to be useful tools in identifying disease-relevant pathways and targets. This review summarizes COPD pathology, current treatments, and therapeutic discovery research, with a focus on the aforementioned pathways that can advance the therapeutic landscape of COPD.
Neuromodulation or energy failure? Metabolic limitations silence network output in the hypoxic amphibian brainstem
Authors: Adams Sasha , Zubov Tanya , Bueschke Nikolaus , Santin Joseph M.
Published: November 2020

Hypoxia tolerance in the vertebrate brain often involves chemical modulators that arrest neuronal activity to conserve energy. However, in intact networks, it can be difficult to determine whether hypoxia triggers modulators to stop activity in a protective manner or whether activity stops because rates of ATP synthesis are insufficient to support network function. Here, we assessed the extent to which neuromodulation or metabolic limitations arrest activity in the respiratory network of bullfrogs—a circuit that survives moderate periods of oxygen deprivation, presumably, by activating an inhibitory noradrenergic pathway. We confirmed that hypoxia and norepinephrine (NE) reduce network output, consistent with the view that hypoxia may cause the release of NE to inhibit activity. However, these responses differed qualitatively; hypoxia, but not NE, elicited a large motor burst and silenced the network. The stereotyped response to hypoxia persisted in the presence of both NE and an adrenergic receptor blocker that eliminates sensitivity to NE, indicating that noradrenergic signaling does not cause the arrest. Pharmacological inhibition of glycolysis and mitochondrial respiration recapitulated all features of hypoxia on network activity, implying that reduced ATP synthesis underlies the effects of hypoxia. Finally, activating modulatory mechanisms that dampen neuronal excitability when ATP levels fall, KATP channels and AMP-dependent protein kinase, did not resemble the hypoxic response. These results suggest that energy failure—rather than inhibitory modulation—silences the respiratory network during hypoxia and emphasize the need to account for metabolic limitations before concluding that modulators arrest activity as an adaptation for energy conservation in the nervous system.
Use of explicit processes during a visually guided locomotor learning task predicts 24-h retention after stroke
Authors: French Margaret A. , Morton Susanne M. , Reisman Darcy S.
Published: November 2020

This study found that stroke survivors used implicit and explicit processes similar to age-matched healthy adults during a visually guided locomotion learning task. The amount of explicit processes was related to how well stroke survivors retained the new walking pattern but not to how well they performed during the task. This work illustrates the importance of understanding the underlying learning mechanisms to maximize retention of a newly learned motor behavior.
The influence of tDCS intensity on decision-making training and transfer outcomes
Authors: Ehrhardt Shane E. , Filmer Hannah L. , Wards Yohan , Mattingley Jason B. , Dux Paul E.
Published: November 2020

Using techniques such as transcranial direct current stimulation to modulate cognitive performance is an alluring endeavor. However, the optimal parameters to augment performance are unknown. Here, in a preregistered study with a large sample (123 subjects), three different stimulation dosages (0.7, 1.0, and 2.0 mA) were applied during multitasking training. Different cognitive training performance outcomes occurred across the dosage conditions, with only one of the doses (1.0 mA) leading to training transfer.
Power Control for Full-Duplex Device-to-Device Underlaid Cellular Networks: A Stackelberg Game Approach
Authors: Yang Zhen , Liu Titi , Chen Guobin
Published: November 2020

In spectrum sharing cognitive radio networks, unauthorized users (secondary users) are allowed to use the spectrum of authorized users (primary users) to improve spectrum utilization. Due to limited spectrum resources, how to formulate a reasonable spectrum allocation scheme is very important. As a mathematical analysis tool, game theory can solve the problem of resource allocation well. In recent years, it has been applied to the research of resource allocation in spectrum sharing networks by some literatures. In a cellular network consisting of multiple cellular users and full-duplex end-to-end communication users D2D (device-to-device), the self-interference caused by full-duplex communication and the interference caused by the D2D users to the cellular users will significantly reduce system throughput. In order to reduce the interference in the network, this paper introduces a power control algorithm based on Stackelberg game, which sets the cellular users and D2D users as the leaders and followers, respectively. The cellular users and the D2D users compete with each other to minimize the cost, and we propose new utility functions. We build an optimization problem under the outage probability constraint and power constraint and the transmission power of the users is obtained by using the Lagrangian dual decomposition method. The simulation results show that the proposed game algorithm improves network performance compared with other existing schemes.
Kinetic Study of Calcium Phosphate Precipitation in the System H3PO4-Ca(OH)2-H2O at 30°C
Authors: Labgairi K. , Borji A. , Kaddami M. , Jourani A.
Published: November 2020

The precipitation kinetics of calcium phosphates, namely, hydroxyapatite (HAP), dicalcium phosphate dihydrate (DCPD), dicalcium phosphate anhydrous (DCPA), and monocalcium phosphate monohydrate (MCPM), were studied at 30°C by mixing calcium hydroxide, water, and phosphoric acid. The studied mixture was selected according to the stability domain of different calcium phosphates by referring to the phase diagram of the ternary system of H3PO4-Ca(OH)2-H2O at 30°C. The precipitation reaction has been monitored by following the changes in the conductivity, pH, and calcium concentration. The solid phases formed at different stages of this precipitation were characterized by X-ray diffraction.
Determination of Optimal Warranty Period with Preventive Maintenance Actions for Items from Heterogeneous Populations
Authors: Park Minjae
Published: November 2020

In this study, we develop an optimal maintenance policy with replacement service and minimal repair service for items from heterogeneous populations and determine the optimal warranty length and repair time threshold. We consider the information-based repair-replacement policy model and develop the formula to evaluate the expected cost rate during the product life cycle. A general formulation is derived for the expected cost rate under a warranty policy for items of heterogeneous populations. When a replacement service and minimal repair service are provided for a failed item, then an item from a weak population has the property of an item from a weak population after service. Similarly, an item from a strong population has the property of an item from a strong population after service. We define the optimal maintenance strategies to minimize the expected cost rate with failure time and repair time for items with heterogeneous reliability characteristics. The effects of parameters of the intensity function for the failure times on the optimal length of the warranty period are studied numerically. Assuming that the product deteriorates, we illustrate the proposed approach using numerical applications and observe the impacts of relevant parameters on the optimal length of the warranty period.
Jaccard and Dice Similarity Measures Based on Novel Complex Dual Hesitant Fuzzy Sets and Their Applications
Authors: Mahmood Tahir , Ur Rehman Ubaid , Ali Zeeshan , Chinram Ronnason
Published: November 2020

Complex dual hesitant fuzzy set (CDHFS) is a combination of two modifications, called complex fuzzy set (CFS) and dual hesitant fuzzy set (DHFS). CDHFS makes two degrees, called membership valued and nonmembership valued in the form of a finite subset of a unit disc in the complex plane, and is a capable method to solve uncertain and unpredictable information in real-life problems. The goal of this study is to describe the notion of CDHFS and its operational laws. The novel approach of the complex interval-valued dual hesitant fuzzy set (CIvDHFS) and its fundamental laws are also described and defended with the help of an example. Further, the vector similarity measures (VSMs), weighted vector similarity measures (WVSMs), hybrid vector similarity measure, and weighted hybrid vector similarity measure are additionally explored. These similarity measures (SM) are applied to the environment of pattern recognition and medical diagnosis to assess the capability and feasibility of the interpreted measures. We additionally solved some numerical examples utilizing the established measures. We examine the dependability and validity of the proposed measures by comparing them with some existing measures. The advantages, comparative analysis, and graphical portrayal of the investigated interpreted measures and existing measures are additionally described in detail.
The Existence of Invariant Tori and Quasiperiodic Solutions of the Nosé–Hoover Oscillator
Authors: Niu Yanmin , Li Xiong
Published: November 2020

In this paper, we consider an equivalent form of the Nosé–Hoover oscillator,

x

′

=
y
,

y

′

=
−
x
−
y
z
,
 
and
 

z

′

=

y

2

−
a

, where

a

is a positive real parameter. Under a series of transformations, it is transformed into a 2-dimensional reversible system about action-angle variables. By applying a version of twist theorem established by Liu and Song in 2004 for reversible mappings, we find infinitely many invariant tori whenever

a

is sufficiently small, which eventually turns out that the solutions starting on the invariant tori are quasiperiodic. The discussion about quasiperiodic solutions of such 3-dimensional system is relatively new.
Some Results on Wijsman Ideal Convergence in Intuitionistic Fuzzy Metric Spaces
Authors: Esi Ayhan , Khan Vakeel A. , Ahmad Mobeen , Alam Masood
Published: November 2020

In the present work, we study and extend the notion of Wijsman

J

–convergence and Wijsman

J

∗

–convergence for the sequence of closed sets in a more general setting, i.e., in the intuitionistic fuzzy metric spaces (briefly, IFMS). Furthermore, we also examine the concept of Wijsman

J

∗

–Cauchy and

J

–Cauchy sequence in the intuitionistic fuzzy metric space and observe some properties.
Evolution of High-Value Patents in Reverse Innovation: Focus on Chinese Local Enterprises
Authors: Wei Tie , Liu Tingting
Published: November 2020

The lack of high-value patents constraints the reverse innovation of developing countries’ local enterprises. To explore how high-value patents evolve within reverse innovation in these enterprises, this paper proposes a theoretical framework to analyze the relationships among technology, law, and market values for high-value patents and builds a three-dimensional Lotka–Volterra model of high-value patents under this framework. Using this model, this study explores the evolution path and the optimal conditions for the formation high-value patents. We take a local Chinese company, Huawei, as a case to test the theoretical analysis and make some managerial suggestions accordingly. Our research provides a theoretical basis for cultivating high-value patents in reverse innovation in local enterprises in China and other developing countries.
A Precipitation Nowcasting Mechanism for Real-World Data Based on Machine Learning
Authors: Xiang Yanfei , Ma Jianbing , Wu Xi
Published: November 2020

Unpredicted precipitations, even mild, may cause severe economic losses to many businesses. Precipitation nowcasting is hence significant for people to make correct decisions timely. For traditional methods, such as numerical weather prediction (NWP), the accuracy is limited because the smaller scale of strong convective weather must be smaller than the minimum scale that the model can capture. And it often requires a supercomputer. Furthermore, the optical flow method has been proved to be available for precipitation nowcasting. However, it is difficult to determine the model parameters because the two steps of tracking and extrapolation are separate. In contrast, current machine learning applications are based on well-selected full datasets, ignoring the fact that real datasets quite often contain missing data requiring extra consideration. In this paper, we used a real Hubei dataset in which a few radar echo data are missing and proposed a proper mechanism to deal with the situation. Furthermore, we proposed a novel mechanism for radar reflectivity data with single altitudes or cumulative altitudes using machine learning techniques. From the experimental results, we conclude that our method can predict future precipitation with a high accuracy when a few data are missing, and it outperforms the traditional optical flow method. In addition, our model can be used for various types of radar data with a type-specific feature extraction, which makes the method more flexible and suitable for most situations.
Particle Swarm Optimization in the Presence of Malicious Users in Cognitive IoT Networks with Data
Authors: Gul Noor , Khan Muhammad Sajjad , Kim Su Min , St-Hilaire Marc , Ullah Ihsan , Kim Junsu
Published: November 2020

With the increasing applications in the domains of ubiquitous and context-aware computing, Internet of Things (IoT) is gaining importance. The study to efficiently exploit and manage a spectrum resources for industrial IoT (IIoT) applications is currently in the interest of research community. As increasing number of IIoT devices is heading towards the future-connected society with the cost of high system complexity, to meet the growing demands of wireless communication in future, cognitive IoT (CIoT) technology is considered as a choice. Reliable detection of the vacant spectrum holes is a vital task in the CIoT network with data. However, the performance of spectrum sensing severely degraded with the existence of malicious users (MUs) which falsifies the sensing results by reporting false data to the fusion center (FC). In this paper, we focus on the use of particle swarm optimization (PSO) to safeguard the cooperative spectrum sensing (CSS) from the negative effects caused by the MUs. The effectiveness of the proposed scheme is verified numerically in various scenarios with different types of MUs through analysis and simulations.
Experimental Study on the Evolution Law of Mesofissure in Full Tailing Cemented Backfill
Authors: Feng Yufan , Sun Guanghua , Liang Xuejian , Liu Chenyang , Wang Yue
Published: November 2020

To understand the mechanical properties of the backfill, to reveal the evolvement of micromechanical fissure of backfill, a uniaxial compression experiment was carried out for the full tailing cemented backfill. After loading, the microstructure of the specimens was observed by microscope and the pore characteristic parameters were analyzed. The results showed that the diameter of the initial damage hole of the backfill was mostly between 0 and 40 μm, the hole diameter increases gradually with the increase of pressure, and the hole diameter reached more than 5000 μm in the postpeak damage stage. The upper structure of the backfill specimen is compact while the lower structure is relatively loose. The cracks and interfaces between tailings particles and cement paste are mechanical weak surfaces, where the cracks are mainly generated and propagated. The tip of microfractures in the backfill is damaged by the influence of stress concentration. In the failure process, both surface porosity and fracture density decrease first and then increase, and the average pore diameter increases gradually. The results have guiding significance for the study of backfill mechanical properties and goaf filling design.
Core Design of a Small Pressurized Water Reactor with AP1000 Fuel Assembly Using SRAC and COBRA-EN Codes
Authors: Hoang Van Khanh
Published: November 2020

This paper presents the core design and performance characteristics of a 300 MWt small modular reactor (SMR) with fuel assemblies of the AP1000 reactor. Numerical calculations have been performed to evaluate a proper active core size and core loading pattern using the SRAC code system with the JENDL-4.0 data library and the CORBRA-EN code. The calculated temperature coefficients including fuel temperature, coolant temperature, and isothermal temperature coefficient provide adequate negative reactivity feedbacks. The thermal-hydraulic analysis reveals acceptable radial and axial fuel element temperature profiles with significant safety margin of fuel and clad surface temperature. A safety analysis using the CORBRA-EN code shows that the core will remain covered during the entire transient procedure of the fast transient of remarkably increasing power that would be caused by the ejection of control rod. The analysis results indicate that the core with a cycle length of 2.22 years is achievable while satisfying the operation and safety-related design criteria with sufficient margins.
Hypoglycemic Effect of a Combined Andrographis paniculata and Caesalpinia sappan Extract in Streptozocin-Induced Diabetic Rats
Authors: Wediasari Febrika , Nugroho Gumilar A. , Fadhilah Zahra , Elya Berna , Setiawan Heri , Mozef Tjandrawati
Published: November 2020

Introduction. Researchers usually use herbal combinations to explore and develop traditional medicine to obtain additional benefits in the treatment of diseases, including diabetes. This study aims to evaluate the hypoglycemic effect of the combination of Andrographis paniculata (Burm. f.) Wall ex Nees and Caesalpinia sappan Linn extract (APCSE) on diabetes-induced rats. There has not been sufficient research on this combination; however, single extract studies of these plants have been widely conducted. Materials and Methods. Male Sprague Dawley rats (160–200 g) were induced by injecting a low dose of streptozotocin (35 mg/kg BW) twice and fed with a high-fat diet containing 25% fat, whereas control animals received only standard feed. Rats were treated with APCSE at doses of 100 mg and 200 mg/kg BW for seven days and compared to the APE and CSE groups treated with the extract at 100 mg, respectively. For the control group, rats were treated with metformin with a dose of 250 mg/kg. The antihyperglycemic and antihyperlipidemic effects were determined by measuring blood glucose levels and lipid profiles (cholesterol, triglycerides, HDL, and LDL). To assess the impact of the extract on pancreatic and adipose tissue, the number of pancreatic beta cells and adipocytes was evaluated through histopathological and immunohistochemical study. Results and Discussion. In a nonfasting state, the blood glucose change in APCSE 200 mg was 18.65% and was significantly lower from the DM group. However, a single extract of APE and CSE showed lower fasting blood glucose levels compared to the combined extract. Lipid profiles show no significant differences in cholesterol levels between groups; however, all treatment groups, including metformin, showed higher triglyceride levels. The APE-treated group showed significantly lower HDL and LDL, whereas CSE only showed lower LDL. The β-cell number was significantly higher after treatment with single extract CSE. The CSE and the combined extract groups showed hyperplasia adipocytes. Conclusion. The combined extract of APCSE has a moderate antihyperglycemic effect; however, a single extract may have better potential than the combined extract.