bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of the complete flux scheme to radio frequency discharge models
Authors: Liu Lei
Published: July 2021

This paper is concerned with the application of transient complete flux scheme to a radio frequency discharge model in a one-dimensional geometry. The transient complete flux scheme and exponential difference scheme are used to discretize plasma fluxes in space. Temporal discretization is performed by using implicit Euler method and the 2-step backward differentiation formula of first and second orders. Numerical experiments are carried out to evaluate the order and level of accuracy. The results obtained by the complete flux scheme prove to have uniformly second-order accuracy for the spatial error and coincide with solutions calculated from the fourth-order deferred correction technique.
Scalar structures around the mixing interface of a thermal mixing layer in multiscale-generated decaying turbulent flows visualized using DNS database
Authors: Jomura Shotaro , Suzuki Hiroki , Mochizuki Shinsuke , Sakai Yasuhiko
Published: July 2021

This study shows the results for the visualization of a scalar mixing layer in decaying turbulence produced by a multiscale-generated turbulence grid. For this purpose, a thermal mixing layer in the air is used as the scalar mixing layer. A fractal generating grid proposed in the previous study is used for the generation of multiscale-generated turbulence. In addition, a parameter for determining the grid shape is varied. The scalar field is then visualized using a database given by direct numerical simulations. The instantaneous scalar field, the instantaneous scalar fluctuation field, the instantaneous scalar variance field, and the scalar dissipation field are visualized, and the visualization results are discussed using the wake interaction length scale.
Inadequacy of the Shannon entropy in quantifying wave-particle duality for three-path interferometers
Authors: Lyu Xin
Published: July 2021

Based on the principle that any introduce of entanglement should not improve the limit of simultaneously obtainable information of the particle aspect and the wave aspect, we show that the Shannon entropy is not suitable for quantifying wave-particle duality by giving a counter example in three-path interferometers.
Orthogonality derivation of polarization state based on Poincaré sphere
Authors: Wang Zhanling , Huang Jiankai , Pang Chen
Published: July 2021

To make full use of the polarization information of electromagnetic waves for the polarimetric sensor array, we derive the orthogonality expression of the polarization state based on the Poincaré sphere (PS) representation. The ellipticity angle and the orientation angle of the ellipse are used to describe the polarization ellipse and the point on the surface of the Poincaré sphere. The derivation shows that two points that characterize a pair of orthogonal polarization states are distributed in the opposite positions. Compared with the conventional linear and circular polarization state, the flexible elliptical polarization state would result in the maximum separation of co-polarization and cross-polarization components, thereby enhancing the accuracy of polarization information measurement. The simulation result displays the correctness of the theoretical derivation, which could provide a basis for the further polarization state configuration.
Power-Maxwell holographic superconductors probed by entanglement entropy
Authors: Yao Weiping , Jiang Jiali , Yang Jiacheng
Published: July 2021

We study the behaviors of entanglement entropy (EE) in the Power-Maxwell holographic superconductors. We observe that the EE is a useful tool to study the critical point of the phase transition. The phase transition is less likely with the Power-Maxwell field. In the condensed phase, the EE gets larger as the strength of the Power-Maxwell field and the width increases. Furthermore, the width modifies the EE more significantly than the Power-Maxwell factor.
Stress field solution to anisotropic plate with mode II crack based on pan-complex function
Authors: Jia Purong , Suo Yongyong , Jia Cheng
Published: July 2021

The crack-tip stress problem to the anisotropic materials was mainly discussed under the shear loading model. For the sake of solving the stress boundary problem, the pan-complex function method was achieved in the first place. The elastic theory of composite materials has been clearly reviewed in order to determine the material physical parameters. Equilibrium equations and deformable compatibility condition were introduced on the basis of plane elastic mechanics. The key to the settlement of the boundary question must lie in solving the partial derivative equation and the axial transformation of the pan-complex variables. The reasonable stress functions were chosen in order to meet the needs of shear loading states. The pan-complex function and the polar coordinate replace approach are utilized with the aim of solving the stress boundary problems for the anisotropic plate. The formulas of the stress components near the crack-tip region were finally determined by the real functions. The method in this article may be much important to the fracture analysis of composite materials.
Electrochemical sensor based on graphene-modified GCE for rapid quantification of benzo(a)pyrene in dark rubber materials
Authors: Zhong Naifei , Yuan Ronghui , He Huihui , Zhong Wenhan , Wang Ying
Published: July 2021

Electrochemical sensor was constructed by depositing graphene on glassy carbon electrode (GCE), and the electrochemical properties of benzo(a)pyrene (BaP) were characterized. An oxidation peak was observed at 1.13 V according to the cyclic voltammogram with no reduction peak appeared. The differential pulse voltammetry revealed that sorption time and acid concentration play a prominent role in the oxidation of BaP-acetonitrile-NaClO4. A good linear relationship between oxidation peak current and concentration within the range from 0.5 to 30 ng mL−1 was developed. The limit of detection was calculated as 0.08 ng mL−1. Further, this reliable method was applied for BaP determination of the dark rubber materials on graphene-modified GCE. The advantages of its sensitivity and portability were noteworthy for the sample pretreatment and rapid quantification of BaP compared with gas chromatography-mass spectrometry method.
Parametric sensitivity analysis of Aerodynamic stability for planar membrane structures
Authors: Du Lingling , Song Weiju
Published: July 2021

To explore the influence of design parameters on the aerodynamic stability of planar membrane structures, a mathematical model for calculating the critical wind speed of flat panel structures was established, and the closed expression of the critical wind speed was obtained through the criterion of instability. The influence of membrane size, membrane density, pretension and other parameters on the critical wind speed was studied by monofactor analysis. The results show that, with the help of the new concept of benefit loss coefficient, the sensitivity analysis of instability critical wind speed parameters can be easily carried out, and many qualitative and quantitative laws can be obtained.
Boundary value problem for a fully nonlinear elliptic equation
Authors: Wu Ruili , Li Junyan
Published: July 2021

In this paper, we investigate the well-posedness of a fully nonlinear elliptic problem. By using the acute angle principle for the weakly continuous operator, we obtained the W
2,p
-strong solution of the fully nonlinear elliptic problem.
An improved multi-objective gravitational search algorithm
Authors: Guo Yuhong , Luo Teng , Cao Hongqian
Published: July 2021

Multi-objective search algorithm is a common optimization tool to deal with complex multi-objective problems, such as Multiple Objectives Particle Swarm Optimization (MOPSO) and Non dominated Sorting Genetic Algorithm-II (NSGA-II). Gravitational Search Algorithm (GSA) is a new heuristic evolutionary algorithm, which is based on the Newtonian gravity and the laws of motion to search optimal solutions. Some of agents have bigger mass, so other smaller mass agents are affected easily to fall into local optimization. In order to improve the search ability of the algorithm, this paper proposes an Improved Multi-Objective Gravitational Search Algorithm (IMOGSA). The proposed method uses the fast non-dominated sorting strategy and crowding distance of NSGA-II, and uses Sine Cosine Algorithm (SCA). Using strategy of NSGA-II is to reduce the complexity of the algorithm, in addition, using SCA is to improve the convergence and distribution of IMOGSA by improving the weight of acceleration. Finally, the proposed method has been compared with other well-known heuristic search methods by using some benchmark functions.
Contradiction argument in the study of convexity for a special case of Hessian equation in the ball
Authors: Lin Xiaomin , Ye Yunhua
Published: July 2021

The convexity is intimately related to geometric properties of solutions to partial differential equations. In this paper, the contradiction argument is used to study some convexity properties for the solutions of a special type of Hessian equation in the unit ball. It reveals that some power of the solution is strictly convex in the ball.
Pricing perpetual American straddle option driven by bifractional Black-Scholes model
Authors: Xu Feng , Ye Min
Published: July 2021

This paper addresses the pricing of perpetual American straddle options under the bifractional Black-Scholes model. We use the comparison principle for the variational inequality to analyze the behaviour of exercise boundaries for the perpetual American straddle option with a constant dividend yield. The conclusion is derived that it has two exercise boundary points with a constant dividend yield and only one free boundary point with zero dividend yield, which is consistent with the financial context.
Risk spillovers between China and other BRICS countries during COVID-19 pandemic: A CoVaR-copula approach
Authors: Cheng Yangnan , Liu Jianxu , Sriboonchitta Songsak
Published: July 2021

This paper aims to assess risk spillover effect between China and other BRICS countries by CoVaR-copula method. We analyse the result of ΔCoVaR in two sub-periods–year 2019 and COVID-19 period. Data for stock prices of major stock market in each country are used. Our results show that risk spillover effect from China to other BRICS countries increased during the epidemic. Meanwhile, COVID-19 pandemic enhanced the co-movement between China and other four countries. Under the shock from other countries, stock market in China stayed strong. By contrast, stock markets in Brazil, India and South Africa are vulnerable. The results show the accuracy of CoVaR-copula approach for risk spillover effect measurement.
Application of one-factor copula with Durante generators to high-dimensional data: empirical study on stock market of China
Authors: Cheng Yangnan , Liu Jianxu , Sriboonchitta Songsak
Published: July 2021

This paper investigates the performance of one-Factor copula with Durante generators (FDG copula) in high-dimensional applications. We use data with 28, 102 and 227 dimensions respectively to compare the mean absolute error in three cases. The results show that estimation error deceases as dimension increases, which means the higher the dimension, the better this model performs. Empirically, we measure the dependence between industrial sectors in Chinese stock market by FDG copulas. It is found that Machinery and equipment sector has the largest dependence coefficients with other sectors. In addition, by comparing the results before and during the COVID-19 pandemic, we find that the epidemic strengthened the connection between the Computer and Media industry and other industries. FDG copulas, tractable and flexible, suits well for high-dimensional estimation. Potential of its application to other fields remains to be discovered.
Project duration-cost-quality prediction model based on Monte Carlo simulation
Authors: Chen Xingguang , Cheng Luqiang , Deng Guohua , Guan Shuqi , Hu Lewei
Published: July 2021

Based on the earned value management theory, the project duration and cost forecast data are obtained through Monte Carlo simulation, combined with the knowledge of mathematical statistics to in-depth analysis of the data, and then the project quality calculation is completed by establishing the quality correlation function. On the basis of existing scholars’ research, at the process level, the management focus is identified by calculating process influence and quality, and at the project level, the operation of the entire project is simulated and predicted by the calculation of the total construction period, cost, and quality.
A fuzzy behavioral portfolio decision model with trapezoidal fuzzy return and aspiration
Authors: Zhang Qiansheng , Yao Haixiang
Published: July 2021

This paper deals with the stock portfolio selection problem involved with trapezoidal fuzzy number returns and multiple mental accounts. A fuzzy behavioral portfolio decision model is proposed to maximize the possibilistic mean value of portfolio return and ensure the portfolio return of each mental account exceeding the given minimum fuzzy aspiration level with a given probability. Then, some programming models are designed to solve the optimal portfolio strategy. Finally, one numerical example is given to illustrate the effectiveness of the proposed fuzzy behavioral portfolio decision approach.
Application of cluster analysis in optimization problem of pricing of a mobile Internet App
Authors: Bai Sixuan , Liao Daiqin , Wang Mei , Ma Yang
Published: July 2021

This paper focus on the problem of task pricing and completion of the tasks of a mobile Internet APP. Based on the original data set, the original pricing model of the project’s tasks was established by using the multiple linear regression analysis. The influences of factors such as the task point’s pricing, number of other tasks, and total task price on tasks completion were analysed. Further, based on the factors which affecting task completion, a new task pricing model was developed by using cluster analysis to tailor the price of some task points and significantly improved the completion of task without increasing the total task price.
Energy intensity gap between enterprises and governments: A global perspective
Authors: Wang Heng , Liu Jianxu , Sriboonchitta Songsak
Published: July 2021

Information asymmetry on energy efficiency target between enterprises and governments is a major controversy about sustainability. Enterprises desire to pursue the maximum profits in the market while governments confront with incomplete information on energy intensity potential and policy implementation. To investigate the influence of information gap between them, this study uses two-tier stochastic frontier (TSF) model with scaling property on the panel data in 56 contracting countries in Kyoto Protocol from 1995 to 2014 on energy intensity from energy, economic and technological perspective. The results present that on average about 70% of the unexplained variations in energy intensity accounts for the influence of energy intensity gap on energy savings potential between enterprises and governments. And the actual energy intensity is upper biased by average 7.03% due to the information asymmetry although the net impacts differ slightly across developing and developed countries and over time. Enterprises have stronger influence on the energy intensity during sample period. We recommend developing countries’ governments to have a strong renewable energy governance framework to support urbanization for economic development is their backbone for long period.
The dynamic dependence of natural gas and renewable energy stock markets
Authors: Zhou Yefan , Liu Jianxu , Sirisrisakulchai Jirakom , Sriboonchitta Songsak
Published: July 2021

We measure the dynamics dependence structure between the European renewable energy stock (ERIX) market, natural gas, and other clean energy markets from 2008 to 2021 by adopting static and time-varying copula approaches. Empirical results show strong and positive dependence between ERIX and S&P global clean energy stock markets symmetric tail dependence, which indicates S&P clean energy assets provide limited hedging condition on the ERIX market and extreme upward and downward clean prices have a similar impact on the ERIX market. Furthermore, our evidence on the co-movement mechanisms between European renewable energy and clean energy markets is helpful for policymakers and investors. Governments need to adopt fiscal policy tools for clean energy firms when renewable energy prices rise (fall) together. Investors can assess and control potential risk contagion between European renewable energy stock markets and other clean energy markets via information about co-movement mechanisms.
Albedo-induced global warming impact of Conservation Reserve Program grasslands converted to annual and perennial bioenergy crops
Authors: Abraha Michael , Chen Jiquan , Hamilton Stephen K , Sciusco Pietro , Lei Cheyenne , Shirkey Gabriela , Yuan Jing , Robertson G Philip
Published: July 2021

Climate benefit assessments of bioenergy crops often focus on biogeochemical impacts, paying little if any attention to biogeophysical impacts. However, land conversions required for large-scale bioenergy crop production are substantial and may directly affect the climate by altering surface energy balance. In the US, such land conversions are likely to be met in part by converting Conservation Reserve Program (CRP) grassland to bioenergy crops. Here, we converted three 22 year old CRP smooth brome grass fields into no-till corn, switchgrass, or restored prairie bioenergy crops. We assessed the biogeophysical climate impact of the conversions using albedo changes relative to unconverted reference CRP grassland. The corn and perennial fields had higher annual albedo than the grassland they replaced—causing cooling of the local climate. The cooling of the corn field occurred solely during the non-growing season—especially when surfaces were snow-covered, whereas the cooling of the perennial fields was more prominent during the growing season. Compared to biogeochemical impacts with fossil fuel offsets for the same land conversions over eight years, the annual albedo-induced climate benefits add ∼35% and ∼78% to the annual biogeochemical benefits provided from the switchgrass and restored prairie fields, respectively, and offset ∼3.3% of the annual greenhouse gas (GHG) emissions from the corn field. We conclude that albedo-induced climate mitigation from conversion of CRP lands to perennial but not annual bioenergy crops can be substantial, and future climate impact assessments of bioenergy crops should include albedo changes in addition to GHG balances in order to better inform climate policies.
Growing farms and groundwater depletion in the Kansas High Plains
Authors: Ao Yufei Z , Hendricks Nathan P , Marston Landon T
Published: July 2021

The average farm size has more than doubled within the United States over the last three decades, transforming the agricultural industry and rural farming communities. It is unclear, however, how this ubiquitous trend has affected and is affected by the environment, particularly groundwater resources critical for food production. Here, we leverage a unique multi-decadal dataset of well-level groundwater withdrawals for crop irrigation over the Kansas High Plains Aquifer to determine the interactions between groundwater depletion and growing farms. Holding key technological, management, and environmental variables fixed, we show that doubling a farm’s irrigated cropland decreases groundwater extractions by 2%–5% depending on the initial farm size. However, a corresponding shift by larger farms to different irrigation technologies offsets this reduction in groundwater use, leading to a slight increase in overall groundwater use. We find groundwater depletion increases the likelihood farmland is sold to a larger farm, amplifying the cycle of groundwater depletion and the consolidation of farmland.
Trends and legacy of freshwater salinization: untangling over 50 years of stream chloride monitoring
Authors: Mazumder Bhaswati , Wellen Christopher , Kaltenecker Georgina , Sorichetti Ryan J , Oswald Claire J
Published: July 2021

Excessive use of road salts to maintain safe winter travel conditions leads to increasing chloride (Cl) concentrations in streams, damaging the structure and function of freshwater ecosystems. Long-term increasing stream Cl trends are generally attributed to increases in urban land cover, however recent research shows that even relatively rural streams can retain Cl and exceed water quality guidelines in summer after road salting has stopped. Untangling the relative influences of long-term changes in streamflow and urban growth on Cl trends is critical for making informed decisions about road salt management. The portion of Cl trends not explained by changes in streamflow or urban growth could be due to changes in road salt application rates and/or legacy Cl in groundwater that is slowly making its way to streams. This study assessed seasonal, long-term stream Cl trends across the Province of Ontario, Canada, where urbanization accelerated and road salt management plans started to develop since early 2000s. We compared stream Cl trends over salting and non-salting seasons with urban growth estimates from two independent time periods, 1965–1995 and 2002–2018. For a subset of sites with sufficient flow data in the periods analyzed, we parsed the seasonal trends into flow and management trend components. We found that most of the variance in the management trend component in the winter salting season could be explained by urbanization, while about half of it could be explained in the summer non-salting season. We further analyzed Cl estimates in low-flow conditions to explore the extent of subsurface contributions to Cl trends, and concluded with a summary of challenges and recommendations for future studies on road salt legacy in streams.
Uniqueness of fat-tailed self-similar profiles to Smoluchowski’s coagulation equation for a perturbation of the constant kernel
Authors: Throm Sebastian
Published: July 2021

This article is concerned with the question of uniqueness of self-similar profiles for Smoluchowski’s coagulation equation which exhibit algebraic decay (fat tails) at infinity. More precisely, we consider a rate kernel

K
K

which can be written as

K
=
2
+
ε
W

K=2+\varepsilon W

. The perturbation is assumed to have homogeneity zero and might also be singular both at zero and at infinity. Under further regularity assumptions on

W
W

, we will show that for sufficiently small

ε
\varepsilon

there exists, up to normalisation of the tail behaviour at infinity, at most one self-similar profile.

Establishing uniqueness of self-similar profiles for Smoluchowski’s coagulation equation is generally considered to be a difficult problem which is still essentially open. Concerning fat-tailed self-similar profiles this article actually gives the first uniqueness statement for a non-solvable kernel.
The nature of intraspecific and interspecific genome size variation in taxonomically complex eyebrights
Authors: Becher Hannes , Powell Robyn F , Brown Max R , Metherell Chris , Pellicer Jaume , Leitch Ilia J , Twyford Alex D
Published: July 2021

Background and aims

Genome size varies considerably across the diversity of plant life. Although genome size is, by definition, affected by genetic presence/absence variants, which are ubiquitous in population sequencing studies, genome size is often treated as an intrinsic property of a species. Here, we studied intra- and interspecific genome size variation in taxonomically complex British eyebrights (Euphrasia, Orobanchaceae). Our aim is to document genome size diversity and investigate underlying evolutionary processes shaping variation between individuals, populations and species.

Methods

We generated genome size data for 192 individuals of diploid and tetraploid Euphrasia and analysed genome size variation in relation to ploidy, taxonomy, population affiliation and geography. We further compared the genomic repeat content of 30 samples.

Key results

We found considerable intraspecific genome size variation, and observed isolation-by-distance for genome size in outcrossing diploids. Tetraploid Euphrasia showed contrasting patterns, with genome size increasing with latitude in outcrossing Euphrasia arctica, but with little genome size variation in the highly selfing Euphrasia micrantha. Interspecific differences in genome size and the genomic proportions of repeat sequences were small.

Conclusions

We show the utility of treating genome size as the outcome of polygenic variation. Like other types of genetic variation, such as single nucleotide polymorphisms, genome size variation may be affected by ongoing hybridization and the extent of population subdivision. In addition to selection on associated traits, genome size is predicted to be affected indirectly by selection due to pleiotropy of the underlying presence/absence variants.
Predation risk shapes the use of conflicting personal risk and social safety information in guppies
Authors: Feyten Laurence E A , Crane Adam L , Ramnarine Indar W , Brown Grant E
Published: July 2021

When faced with uncertainty, animals can benefit from using multiple sources of information in order to make an optimal decision. However, information sources (e.g., social and personal cues) may conflict, while also varying in acquisition cost and reliability. Here, we assessed behavioral decisions of Trinidadian guppies (Poecilia reticulata), in situ, when presented with conflicting social and personal information about predation risk. We positioned foraging arenas within high- and low-predation streams, where guppies were exposed to a personal cue in the form of conspecific alarm cues (a known indicator of risk), a novel cue, or a control. At the same time, a conspecific shoal (a social safety cue) was either present or absent. When social safety was absent, guppies in both populations showed typical avoidance responses towards alarm cues, and high-predation guppies showed their typical avoidance of novel cues (i.e., neophobia). However, the presence of social safety cues was persuasive, overriding the neophobia of high-predation guppies and emboldening low-predation guppies to ignore alarm cues. Our experiment is one of the first to empirically assess the use of safety and risk cues in prey and suggests a threshold level of ambient risk which dictates the use of conflicting social and personal information.
Reviewing and assessing existing meta-analysis models and tools
Authors: Makinde Funmilayo L , Tchamga Milaine S S , Jafali James , Fatumo Segun , Chimusa Emile R , Mulder Nicola , Mazandu Gaston K
Published: July 2021

Over the past few years, meta-analysis has become popular among biomedical researchers for detecting biomarkers across multiple cohort studies with increased predictive power. Combining datasets from different sources increases sample size, thus overcoming the issue related to limited sample size from each individual study and boosting the predictive power. This leads to an increased likelihood of more accurately predicting differentially expressed genes/proteins or significant biomarkers underlying the biological condition of interest. Currently, several meta-analysis methods and tools exist, each having its own strengths and limitations. In this paper, we survey existing meta-analysis methods, and assess the performance of different methods based on results from different datasets as well as assessment from prior knowledge of each method. This provides a reference summary of meta-analysis models and tools, which helps to guide end-users on the choice of appropriate models or tools for given types of datasets and enables developers to consider current advances when planning the development of new meta-analysis models and more practical integrative tools.
Learning to SMILES: BAN-based strategies to improve latent representation learning from molecules
Authors: Wu Cheng-Kun , Zhang Xiao-Chen , Yang Zhi-Jiang , Lu Ai-Ping , Hou Ting-Jun , Cao Dong-Sheng
Published: July 2021

Computational methods have become indispensable tools to accelerate the drug discovery process and alleviate the excessive dependence on time-consuming and labor-intensive experiments. Traditional feature-engineering approaches heavily rely on expert knowledge to devise useful features, which could be costly and sometimes biased. The emerging deep learning (DL) methods deliver a data-driven method to automatically learn expressive representations from complex raw data. Inspired by this, researchers have attempted to apply various deep neural network models to simplified molecular input line entry specification (SMILES) strings, which contain all the composition and structure information of molecules. However, current models usually suffer from the scarcity of labeled data. This results in a low generalization ability of SMILES-based DL models, which prevents them from competing with the state-of-the-art computational methods. In this study, we utilized the BiLSTM (bidirectional long short term merory) attention network (BAN) in which we employed a novel multi-step attention mechanism to facilitate the extracting of key features from the SMILES strings. Meanwhile, SMILES enumeration was utilized as a data augmentation method in the training phase to substantially increase the number of labeled data and enlarge the probability of mining more patterns from complex SMILES. We again took advantage of SMILES enumeration in the prediction phase to rectify model prediction bias and provide a more accurate prediction. Combined with the BAN model, our strategies can greatly improve the performance of latent features learned from SMILES strings. In 11 canonical absorption, distribution, metabolism, excretion and toxicity-related tasks, our method outperformed the state-of-the-art approaches.
Predicting potential small molecule–miRNA associations based on bounded nuclear norm regularization
Authors: Chen Xing , Zhou Chi , Wang Chun-Chun , Zhao Yan
Published: July 2021

Mounting evidence has demonstrated the significance of taking microRNAs (miRNAs) as the target of small molecule (SM) drugs for disease treatment. Given the fact that exploring new SM–miRNA associations through biological experiments is extremely expensive, several computing models have been constructed to reveal the possible SM–miRNA associations. Here, we built a computing model of Bounded Nuclear Norm Regularization for SM–miRNA Associations prediction (BNNRSMMA). Specifically, we first constructed a heterogeneous SM–miRNA network utilizing miRNA similarity, SM similarity, confirmed SM–miRNA associations and defined a matrix to represent the heterogeneous network. Then, we constructed a model to complete this matrix by minimizing its nuclear norm. The Alternating Direction Method of Multipliers was adopted to minimize the nuclear norm and obtain predicted scores. The main innovation lies in two aspects. During completion, we limited all elements of the matrix within the interval of (0,1) to make sure they have practical significance. Besides, instead of strictly fitting all known elements, a regularization term was incorporated to tolerate the noise in integrated similarities. Furthermore, four kinds of cross-validations on two datasets and two types of case studies were performed to evaluate the predictive performance of BNNRSMMA. Finally, BNNRSMMA attained areas under the curve of 0.9822 (0.8433), 0.9793 (0.8852), 0.8253 (0.7350) and 0.9758 ± 0.0029 (0.8759 ± 0.0041) under global leave-one-out cross-validation (LOOCV), miRNA-fixed LOOCV, SM-fixed LOOCV and 5-fold cross-validation based on Dataset 1(Dataset 2), respectively. With regard to case studies, plenty of predicted associations have been verified by experimental literatures. All these results confirmed that BNNRSMMA is a reliable tool for inferring associations.
Alpha-Band Phase Modulates Bottom-up Feature Processing
Authors: Jia Jianrong , Fan Ying , Luo Huan
Published: July 2021

Recent studies reveal that attention operates in a rhythmic manner, that is, sampling each location or feature alternatively over time. However, most evidence derives from top-down tasks, and it remains elusive whether bottom-up processing also entails dynamic coordination. Here, we developed a novel feature processing paradigm and combined time-resolved behavioral measurements and electroencephalogram (EEG) recordings to address the question. Specifically, a salient color in a multicolor display serves as a noninformative cue to capture attention and presumably reset the oscillations of feature processing. We then measured the behavioral performance of a probe stimulus associated with either high- or low-salient color at varied temporal lags after the cue. First, the behavioral results (i.e., reaction time) display an alpha-band (~8 Hz) profile with a consistent phase lag between high- and low-salient conditions. Second, simultaneous EEG recordings show that behavioral performance is modulated by the phase of alpha-band neural oscillation at the onset of the probes. Finally, high- and low-salient probes are associated with distinct preferred phases of alpha-band neural oscillations. Taken together, our behavioral and neural results convergingly support a central function of alpha-band rhythms in feature processing, that is, features with varied saliency levels are processed at different phases of alpha neural oscillations.
Epidemiology and Risk of Coronavirus Disease 2019 Among Travelers at Airport and Port Quarantine Stations Across Japan: A Nationwide Descriptive Analysis and an Individually Matched Case-Control Study
Authors: Tsuboi Motoyuki , Hachiya Masahiko , Ohtsu Hiroshi , Akashi Hidechika , Miyoshi Chiaki , Umeda Tamami
Published: July 2021

Background

The epidemiology and risk of coronavirus disease 2019 (COVID-19) among travelers at international borders remain unclear.

Methods

We conducted descriptive and individually matched case-control studies using a nationwide register for COVID-19 testing of travelers from 3 August to 31 October 2020 at airport/port quarantine stations across Japan. Case patients, defined as travelers positive for COVID-19 on arrival, were individually matched with 4 controls for arrival date and airport or port. We assessed associations between test positivity and traveler characteristics using conditional logistic regression analysis.

Results

Overall, 157 507 travelers arriving from 146 countries/areas at 17 quarantine stations across Japan were tested for COVID-19. The percentage of test positivity during the study period was 0.35%. In the case-control study, with 536 case patients and 2144 controls, we found evidence of lower test positivity in travelers aged 3–19 years, female travelers, and travel corridor users (adjusted odds ratio [95% confidence interval], 0.36 [.22–.60], 0.71 [.56–.89], and 0.48 [.30–.77], respectively), whereas higher positivity was associated with arrival from South-East Asia (1.88 [1.33–2.65]) or lower-middle- or low-income countries (2.46 [1.69–3.58] and 7.25 [2.22–23.66], respectively), any symptom (4.08 [1.43–11.65]), and nasopharyngeal compared with saliva sampling (2.75 [1.85–4.09]). A higher 14-day average incidence in the countries of stay was also associated with higher test positivity (1.64 [1.16–2.33] and 3.13 [1.88–5.23] for those from countries and areas where the 14-day average incidence was from 10 to <100 and ≥100 cases per million, respectively).

Conclusions

These findings justify travel restrictions based on the epidemic situation in countries of stay, although underestimation of the epidemic in lower-income countries should be considered. A strict travel corridor could also reduce the risk of COVID-19 importation.
Reintervention rates following bioprosthetic surgical aortic valve replacement—a Danish Nationwide Cohort Study
Authors: Schmiegelow Michelle D S , Elming Hanne , Sibilitz Kirstine L , Bruun Niels E , Carranza Christian L , Dahl Jordi S , Fosbøl Emil , Køber Lars , Torp-Pedersen Christian , Schmiegelow Søren S
Published: July 2021

OBJECTIVES

Updated European guidelines recommend annual echocardiographic evaluation after bioprosthetic surgical aortic valve replacement (bio-SAVR). Given the increased demand on health care resources, only clinically relevant controls can be prioritized. We therefore aimed to explore reintervention rates following bio-SAVR.

METHODS

From the nationwide Danish Register of Surgical Procedures, we identified all patients ≥40 years with isolated bio-SAVR ± concomitant coronary artery bypass graft surgery (CABG) during 2000–2016. In 90-day reintervention-free survivors, we assessed aortic valve reintervention rates (primary outcome) and all-cause mortality rates (secondary outcome) at 1, 3 and 5 years with total follow-up until 31 December 2017 and further estimated annual theoretical echocardiographic control visits.

RESULTS

In 10 518 patients with bio-SAVR (+CABG 39.7%), we observed low reintervention rates at 1, 3 and 5 years, but with high rates of all-cause mortality; i.e. 5-year reintervention rate of 3.7/1000 person-years (≤1.5%) and 5-year mortality rate of 21.7/1000 person-years. Accounting for the competing risk of death, 5-year rates were inversely related to age group and remained relatively low across all age categories but increased gradually in the long term. A significant proportion of reinterventions were presumed due to infectious endocarditis (48% at 3 years, 37% at 5 years). With annual transthoracic echocardiography, the theoretical ratio of echocardiographies per reintervention in the first 5 years was 248, and 425 when endocarditis events were excluded.

CONCLUSION

Reintervention rates within the first 5 years following bio-SAVR were relatively rare, and with a substantial number due to endocarditis.
Strong host-specific selection and over-dominance characterize arbuscular mycorrhizal fungal root colonizers of coastal sand dune plants of the Mediterranean region
Authors: Tsiknia M , Skiada V , Ipsilantis I , Vasileiadis S , Kavroulakis N , Genitsaris S , Papadopoulou K K , Hart M , Klironomos J , Karpouzas D G , Ehaliotis C
Published: July 2021

Sand dunes of the Mediterranean region constitute drought-stressed, low-fertility ecosystems. Arbuscular mycorrhizal fungi (AMF) are regarded as key components of their biota, that contribute to plant host adaptation and fitness. However, AMF community assembly rules in the roots of the psammophilous plants of coastal sand dunes have not been investigated. We studied the root colonizing AMF communities of four characteristic native plants of eastern Mediterranean coastal foredunes, in nine locations in Greece. Host specificity (plant identity) was the major driver of AMF community assembly in the plant roots, while geographical distance between locations was not related to differences in the AMF communities. Additionally, colonizer AMF communities were characterized by overdominance of a single OTU which was remarkably host-specific among locations. Wider dissimilarity in AMF communities was observed in small and disturbed (SD) sites compared to large and undisturbed (LU) sites, a trait that may be attributed to relaxed environmental filtering and facilitated AMF dispersal/immigration in SD sites from surrounding habitats. Overall, our results indicate that the assembly of root-colonizing AMF communities in the eastern Mediterranean sand dunes is characterized by strong biotic filtering (host identity), suggesting that co-adaptation processes may be more pronounced than previously proposed, under extreme environmental conditions.
Utilization of ethanol for itaconic acid biosynthesis by engineered Saccharomyces cerevisiae
Authors: Xu Yaying , Li Zhimin
Published: July 2021

In Saccharomyces cerevisiae, ethanol can serve as both a carbon source and NADH donor for the production of acetyl-CoA derivatives. Here we investigated the metabolic regulation of ethanol utilization for itaconic acid production by S. cerevisiae. To understand the interconnection between the TCA cycle and the glyoxylate pathway, mitochondrial membrane transporter proteins SFC1, YHM2, CTP1, DIC1 and MPC1 were knocked out and results showed that SFC1 functions as an important entrance of the glyoxylate pathway into the TCA cycle, and YHM2 is helpful to IA production but not the primary pathway for citric acid supply. To decrease the accumulation of acetic acid, the major ADP/ATP carrier of the mitochondrial inner membrane, AAC2, was upregulated and determined to accelerate ethanol utilization and itaconic acid production. RNA sequencing results showed that AAC2 overexpression enhanced IA titer by upregulating the ethanol-acetyl-CoA pathway and NADH oxidase in the mitochondrial membrane. RNA-seq analysis also suggested that aconitase ACO1 may be a rate-limiting step of IA production. However, the expression of exogenous aconitase didn't increase IA production but enhanced the rate of ethanol utilization and decreased cell growth.
Gradient-boosted equivalent sources
Authors: Soler Santiago R , Uieda Leonardo
Published: July 2021

The equivalent source technique is a powerful and widely used method for processing gravity and magnetic data. Nevertheless, its major drawback is the large computational cost in terms of processing time and computer memory. We present two techniques for reducing the computational cost of equivalent source processing: block-averaging source locations and the gradient-boosted equivalent source algorithm. Through block-averaging, we reduce the number of source coefficients that must be estimated while retaining the minimum desired resolution in the final processed data. With the gradient-boosting method, we estimate the sources coefficients in small batches along overlapping windows, allowing us to reduce the computer memory requirements arbitrarily to conform to the constraints of the available hardware. We show that the combination of block-averaging and gradient-boosted equivalent sources is capable of producing accurate interpolations through tests against synthetic data. Moreover, we demonstrate the feasibility of our method by gridding a gravity data set covering Australia with over 1.7 million observations using a modest personal computer.
Spinal cord injury during selective cerebral perfusion and segmental artery occlusion: an experimental study
Authors: Honkanen Hannu-Pekka , Mustonen Caius , Tuominen Hannu , Kiviluoma Kai , Anttila Vesa , Juvonen Tatu
Published: July 2021

OBJECTIVES

Since selective cerebral perfusion (SCP) has been used in aortic arch surgical procedures, the core temperature during lower body circulatory arrest (LBCA) has been steadily rising. Simultaneously, the use of a frozen elephant trunk (FET) graft has been increasing. The safe period of LBCA in relation to spinal cord ischaemic tolerance in combination with segmental artery occlusion by the FET procedure has not been defined.

METHODS

Sixteen pigs were assigned to undergo 65 (n = 10) or 90 min (n = 6) of SCP at 28°C with LBCA in combination with occlusion of the 8 uppermost segmental arteries in the thoracic (Th) aorta (15–20 cm FET, Th8-level). The follow-up period consisted of a 6-h intensive period and a 5-day observation period. Near-infrared spectroscopy of the collateral network was used to determine spinal cord oxygenation. The neurological status of the patients was evaluated daily, and the brain and the spinal cord were harvested for a histopathological analysis.

RESULTS

Five out of 6 pigs after 90 min and 1 out of 10 pigs after 65 min of LBCA died within 48 h of multiorgan failure. Of the survivors in the 65-min group, 6 out of 9 had paraparesis/paraplegia; the remaining 3 reached normal function. The lone survivor after 90 min of LBCA was paraplegic. Nadir near-infrared spectroscopy of the collateral network values at Th8 and Th10 were 34 (±5) and 39 (±4), and they were reached within 35 min of SCP in both groups.

CONCLUSIONS

An extended FET graft with LBCA and SCP durations >65 min at 28°C results in a poor outcome.
Potential test-negative design study bias in outbreak settings: application to Ebola vaccination in Democratic Republic of Congo
Authors: Pearson Carl A B , Edmunds W John , Hladish Thomas J , Eggo Rosalind M
Published: July 2021

Background

Infectious disease outbreaks present unique challenges to study designs for vaccine evaluation. Test-negative design (TND) studies have previously been used to estimate vaccine effectiveness and have been proposed for Ebola virus disease (EVD) vaccines. However, there are key differences in how cases and controls are recruited during outbreaks and pandemics of novel pathogens, whcih have implications for the reliability of effectiveness estimates using this design.

Methods

We use a modelling approach to quantify TND bias for a prophylactic vaccine under varying study and epidemiological scenarios. Our model accounts for heterogeneity in vaccine distribution and for two potential routes to testing and recruitment into the study: self-reporting and contact-tracing. We derive conventional and hybrid TND estimators for this model and suggest ways to translate public health response data into the parameters of the model.

Results

Using a conventional TND study, our model finds biases in vaccine effectiveness estimates. Bias arises due to differential recruitment from self-reporting and contact-tracing, and due to clustering of vaccination. We estimate the degree of bias when recruitment route is not available, and propose a study design to eliminate the bias if recruitment route is recorded.

Conclusions

Hybrid TND studies can resolve the design bias with conventional TND studies applied to outbreak and pandemic response testing data, if those efforts collect individuals’ routes to testing. Without route to testing, other epidemiological data will be required to estimate the magnitude of potential bias in a conventional TND study. Since these studies may need to be conducted retrospectively, public health responses should obtain these data, and generic protocols for outbreak and pandemic response studies should emphasize the need to record routes to testing.
Home Medicines Review and frailty among community-dwelling older women
Authors: Thiruchelvam Kaeshaelya , Byles Julie , Hasan Syed Shahzad , Egan Nicholas , Kairuz Therese
Published: July 2021

Objectives

Home Medicines Reviews (HMRs) can optimize medications for frail older adults. This study aimed to determine the use of HMRs according to frailty status and the association between frailty and use of HMRs.

Methods

The study included 9139 female participants enrolled in the Australian Longitudinal Study on Women’s Health from 2003 (aged 77–82 years) to 2017 (aged 91–96 years). Generalized estimating equations (GEEs) using log-binomial regressions were used to determine associations using repeated measures on individuals over time.

Key findings

The majority of participants in the study remained non-frail and did not receive HMRs from 2003 [7116 (77.86%)] to 2017 [1240 (71.31%)]. The use of HMRs was low in both groups with 33 (1.68%; 95% CI, 1.16 to 2.36) frail and 64 (0.89%; 95% CI, 0.69 to 1.14) non-frail participants receiving HMRs in 2003; by 2017, 19 (4.19%; 95% CI, 2.54 to 6.46) frail and 45 (3.50%; 95% CI, 2.57 to 4.66) non-frail participants received HMRs. Frailty was not associated with receiving a HMR (RR 1.06; 95% CI, 0.95 to 1.20), although for every 1-year increase, participants were 10% more likely to receive a HMR (RR 1.10; 95% CI, 1.09 to 1.11). Participants with continuous polypharmacy, ≥4 chronic diseases, >4 general practitioner visits and Department of Veterans Affairs coverage were more likely to receive a HMR.

Conclusions

Despite the proven value of HMRs for frail older people, HMRs were not used for most frail and non-frail community-dwelling women in this study. Reasons for low use of the service should be explored, with interventions to raise awareness of the benefits of the service.