bluuebunny/crossref_metadata_2025 huggingface dataset:
Time trends and heterogeneity in the disease burden of trachoma, 1990–2019: a global analysis
Authors: He Jingxin , Chen Aiming , Zou Minjie , Young Charlotte Aimee , Jin Ling , Zheng Danying , Jin Guangming , Congdon Nathan
Published: September 2021

Purpose

To evaluate the epidemiological trends and associated risk factors of disease burden due to trachoma.

Methods

Data for the country-specific disability-adjusted life year (DALY) number, rate and age-standardised rate of trachoma together with related data of other common eye diseases were acquired from the Global Burden of Disease Study 2019 database. The Socio-Demographic Index (SDI), Human Development Index (HDI), inequality-adjusted HDI and other related indices were obtained from published data or publicly available databases. Regression analyses were conducted to evaluate the associations between potential risk factors and the age-standardised DALY burden of trachoma.

Results

The global DALY burden due to trachoma decreased by 37% from 1990 to 2019 and decreased by 69.8% after adjusting for age and population growth, and, in available 1990–2019 data, had the greatest reduction in attributable DALYs of all common eye disease, with the others analysed being cataract, glaucoma, refractive disorders and age-related macular degeneration. Women had higher age-standardised DALY burden due to trachoma than men (p<0.001). The African region (p<0.001) had the heaviest burden among global regions. The age-standardised DALY rate was higher in countries with lower income (p<0.001) and lower SDI (p<0.001). Higher disease burden due to trachoma was associated with lower HDI (β=−48.102, 95% CI −86.888 to −9.316, p=0.016), lower SDI (β=−48.063, 95% CI −83.702 to −12.423, p<0.001) and lower expected years of schooling (β=−2.352, 95% CI −3.756 to −0.948, p=0.002).

Conclusions

The global disease burden due to trachoma decreased from 1990 to 2019 and it had the greatest reduction compared with other common eye diseases. Lower HDI, socioeconomic status and educational level were related to a higher national disease burden of trachoma. Our findings could provide necessary information for trachoma control and prevention.
Cohort profile: Prematurity Immunology in Mothers living with HIV and their infants Study (PIMS)
Authors: Malaba Thokozile R , Myer Landon , Gray Clive , Newell Marie-Louise
Published: September 2021

Purpose

Prematurity Immunology in Mothers living with HIV and their infants Study (PIMS) is a prospective cohort study in South Africa investigating the association between antiretroviral therapy (ART) use, preterm delivery (PTD) and small-for-gestational age (SGA) live births. PIMS main hypotheses are that ART initiation in pregnancy and ART-induced hypertension are associated with PTD and SGA respectively and that reconstitution of cellular immune responses in women on ART from before pregnancy results in increases in PTD of GA infants.

Participants

Pregnant women (n=3972) aged ≥18 years regardless of HIV status recruited from 2015 to 2016 into the overall PIMS cohort (2517 HIV-negative, 1455 living with HIV). A nested cohort contained 551 women living with HIV who were ≤24 weeks’ GA on ultrasound: 261 initiated ART before pregnancy, 290 initiated during the pregnancy.

Findings to date

Women in the overall cohort were followed antenatally through to delivery using routine clinical records; further women in the nested cohort were actively followed up until 12 months post partum, with data collected on maternal health (HIV care and ART use, clinical care and intercurrent clinical history). Other procedures conducted on the nested cohort included physical examinations (anthropometry, blood pressure measurement), assessment of fetal growth (ultrasound), maternal and infant phlebotomy for storage of plasma, RNA and peripheral blood mononuclear cells, collection of delivery specimens (placenta and cord blood) and infant 12-month developmental assessment. Preliminary findings have contributed to our understanding of risk factors for adverse birth outcomes, and the relationship between pregnancy immunology, HIV/ART and adverse birth outcomes.

Future plans

Using specimens collected from study participants living with HIV throughout pregnancy and first year of life, the PIMS provides a valuable platform for answering a variety of research questions focused on temporal changes of immunology markers in women whose immune status is altered by HIV infection, and how ART initiated during the pregnancy affects immune responses. The relationship between these immunological changes with adverse birth outcomes as well as possible longer-term impact of exposure to ART in fetal and early life will be explored. Additionally, further active and passive follow-up of mothers and their infants is planned at school-going age and beyond to chart growth, morbidity and development, as well as changes in family circumstances.
ReIMAGINE Prostate Cancer Screening Study: protocol for a single-centre feasibility study inviting men for prostate cancer screening using MRI
Authors: Marsden Teresa , Lomas Derek J , McCartan Neil , Hadley Joanna , Tuck Steve , Brown Louise , Haire Anna , Moss Charlotte Louise , Green Saran , Van Hemelrijck Mieke , Coolen Ton , Santaolalla Aida , Isaac Elizabeth , Brembilla Giorgio , Kopcke Douglas , Giganti Francesco , Sidhu Harbir , Punwani Shonit , Emberton Mark , Moore Caroline M
Published: September 2021

Introduction

The primary objective of the ReIMAGINE Prostate Cancer Screening Study is to explore the uptake of an invitation to prostate cancer screening using MRI.

Methods and analysis

The ReIMAGINE Prostate Cancer Screening Study is a prospective single-centre feasibility study. Eligible men aged 50–75 years with no prior prostate cancer diagnosis or treatment will be identified through general practitioner practices and randomly selected for invitation. Those invited will be offered an MRI scan and a prostate-specific antigen (PSA) blood test. The screening MRI scan consists of T2-weighted, diffusion-weighted and research-specific sequences, without the use of intravenous contrast agents. Men who screen positive on either MRI or PSA density will be recommended to have standard of care (National Health Service) tests for prostate cancer assessment, which includes multiparametric MRI. The study will assess the acceptability of an MRI-based prostate screening assessment and the prevalence of cancer detected in MRI-screened men. Summary statistics will be used to explore baseline characteristics in relation to acceptance rates and prevalence of cancer.

Ethics and dissemination

ReIMAGINE Prostate Cancer Screening is a single-site screening study to assess the feasibility of MRI as a screening tool for prostate cancer. Ethical approval was granted by London–Stanmore Research Ethics Committee Heath Research Authority (reference 19/LO/1129). Study results will be published in peer-reviewed journals after completion of data analysis and used to inform the design of a multicentre screening study in the UK.

Trial registration number

ClinicalTrials.gov Registry (NCT04063566).
Under-5 mortality in sub-Saharan Africa: is maternal age at first childbirth below 20 years a risk factor?
Authors: Ahinkorah Bright Opoku
Published: September 2021

Objectives

This study aimed at examining the association between young maternal age at first childbirth and under-5 mortality in sub-Saharan Africa (SSA).

Design and setting

This cross-sectional study pooled nationally-representative data from the most recent Demographic and Health Surveys conducted in 30 countries in SSA from 2010 to 2019.

Participants

116 379 mothers of children under 5.

Results

The prevalence of adolescent childbirth and death in children under 5 in SSA were 57.36% (95% CI 53.73% to 60.99%) and 4.10% (95% CI 3.65% to 4.54%), respectively. Children born to mothers whose first childbirth occurred at <20 years were 11% more likely to die before the age of 5 compared with those whose mothers’ first childbirth occurred at age ≥20 years (adjusted odds ratio (aOR) 1.11; 95% CI 1.05 to 1.18). In terms of the covariates, the likelihood of under-5 mortality was higher among children born to single (aOR 1.54; 95% CI 1.41 to 1.67) and cohabiting mothers (aOR 1.10; 95% CI 1.01 to 1.21) compared with married mothers. Children born to mothers who were obese were more likely to die before the age of 5 compared with those born to mothers with normal body weight (aOR 1.17; 95% CI 1.09 to 1.26). The odds of under-5 mortality were higher among children whose weight at birth was <2500 g compared with those whose weight was ≥2500 g at birth (aOR 1.83; 95% CI 1.64 to 2.03).

Conclusions

The findings call for the need to enhance policies aimed at reducing under-5 mortality in SSA by reducing adolescent pregnancy and childbirth through family planning, comprehensive sexuality education, and the elimination of child marriage. Again, Since under-5 mortality among adolescent mothers is linked with their poor socio-economic status, there is the need for government and non-governmental organisations in SSA to introduce poverty alleviation programmes and improve access to both formal and informal education as a way of enhancing the socioeconomic status of adolescent mothers. Public health education, through continuous advocacy programmes should be done to encourage adolescent mothers to access antenatal care and health facility deliveries as a way of enhancing the survival status of their children. These interventions should be implemented, taking into consideration other characteristics of mothers such marital status and BMI and child’s characteristics such as child’s weight, which were found to be associated with high under-5 mortality.
Global access to COVID-19 vaccines: a scoping review of factors that may influence equitable access for low and middle-income countries
Authors: Peacocke Elizabeth F , Heupink Lieke Fleur , Frønsdal Katrine , Dahl Elin Hoffmann , Chola Lumbwe
Published: September 2021

Objective

To identify the factors contributing to equitable access to COVID-19 vaccines for low and middle-income countries (LMIC).

Methods

We conducted a scoping review following the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews and a five-stage framework for scoping studies. We performed systematic searches for published peer-reviewed literature in five databases: Medline, Embase, Web of Science, Global Index Medicus and COVID-19 Evidence Epistemonikos (August 2020, updated May 2021).

Results

Systematic selection according to predefined criteria resulted in the final inclusion of 45 peer-reviewed articles, with no limitations on study design or publication type. We derived four key factors that potentially influence equitable access to COVID-19 vaccines in LMICs: (1) collectively agreed global mechanisms or frameworks; (2) bilateral purchasing, contracting, and vaccine prices; (3) vaccine manufacturing that is supported by sharing know-how; and (4) countries’ strength in implementing vaccination programmes.

Conclusions

This scoping review highlights the ongoing challenges for the international community in ensuring equitable access to COVID-19 vaccines for LMICs. The literature suggests that vaccine manufacturing can influence the supply of vaccines, as can the role of patent holders who can influence global governance through their role in the distribution of COVID-19 vaccines. Our findings indicate that including the principles of equitable access throughout vaccine research and development, procurement, scale-up and distribution processes can support equitable access for LMICs. Advances made with mRNA vaccines may have additional benefits in relation to expanding the manufacturing of other vaccine. Finally, the exploration and scale-up of such capacities of LMICs are likely to prove to be a valuable investment, even after the pandemic.
Assessment of difference in postpartum depression among caesarean and vaginally delivered women at 6-week follow-up in hospitals in Pune District, India: an observational cohort study
Authors: Doke Prakash P , Vaidya Varsha Mahesh , Narula Arvinder Pal Singh , Datar Manjiri Chaitanya , Patil Archana Vasantrao , Panchanadikar Tushar Madhav , Wagh Girija Narendrakumar
Published: September 2021

Objectives

To compare the proportion of postpartum depression at 6 weeks among women who had caesarean delivery and women who had vaginal delivery and to assess its association with some sociodemographic factors.

Design

This is a descriptive comparative study with prospective enrolment. We followed the enrolled women and assessed them for postpartum depression 6 weeks after delivery.

Setting

We conducted the study in Pune District, India from July 2017 to December 2018. The study sites were all non-teaching government hospitals performing five or more caesarean sections per month and two teaching hospitals: one government and one private.

Participants

We included in the study group women who have undergone caesarean section in the participating hospitals and were residents of Pune District. Women who delivered vaginally and matched in age and parity were included in the comparison group. We followed 1556 women in each group.

Main outcome measures

An Edinburgh Postnatal Depression Scale score of 10 or more for each woman was the primary outcome. χ2test and multivariable binary logistic regression were performed to assess the effect of mode of delivery on postpartum depression.

Results

The proportion of postpartum depression at 6 weeks was 3.79% among women who had caesarean delivery and 2.35% among those who had vaginal delivery (χ2=4.50, p=0.03). The adjusted OR was 1.86 (95% CI 1.14 to 3.03). Women of age less than 25 years had higher risk of postpartum depression. The adjusted OR was 2.10 (95% CI 1.21 to 3.65). The study did not observe any association between postpartum depression and income, education, occupation or sex of the newborn child.

Conclusions

We conclude that young women particularly those who had caesarean delivery should be screened 6 weeks after delivery.
Remote mental health services: a mixed-methods survey and interview study on the use, value, benefits and challenges of a national video consulting service in NHS Wales, UK
Authors: Johns Gemma , Burhouse Anna , Tan Jacinta , John Oliver , Khalil Sara , Williams Jessica , Whistance Bethan , Ogonovsky Mike , Ahuja Alka
Published: September 2021

Social distancing laws during the first year of the pandemic, and its unprecedented changes to the National Health Service (NHS) forced a large majority of services, especially mental health teams to deliver patient care remotely. For many, this approach was adopted out of necessity, rather than choice, thus presenting a true ‘testing ground’ for remote healthcare and a robust evaluation on a national and representative level.

Objective

To extract and analyse mental health specific data from a national dataset for 1 year (March 2020–March 2021).

Design

A mixed-methods study using surveys and interviews.

Setting

In NHS mental health services in Wales, UK.

Participants

With NHS patients and clinicians across child and adolescent, adult and older adult mental health services.

Outcome measures

Mixed methods data captured measures on use, value, benefits and challenges of video consulting (VC).

Results

A total of 3561 participants provided mental health specific data. These data and its findings demonstrate that remote mental health service delivery, via the method of VC is highly satisfactory, well-accepted and clinically suitable for many patients, and provides a range of benefits to NHS patients and clinicians. Interestingly, clinicians working from ‘home’ rated VC more positively compared with those at their ‘clinical base’.

Conclusions

Post 1-year adoption, remote mental health services in Wales UK have demonstrated that VC is possible from both a technical and behavioural standpoint. Moving forward, we suggest clinical leaders and government support to sustain this approach ‘by default’ as an option for NHS appointments.
Prevalence and predictors of burnout among nurses during COVID-19: a cross-sectional study in hospitals in central Uganda
Authors: Kabunga Amir , Okalo Ponsiano
Published: September 2021

Objective

To determine the prevalence of burnout and associated factors among nurses during COVID-19 in central Uganda.

Design

A cross-sectional design.

Setting

Nurse from one referral and four general hospitals. These were reception centres and cared for patients with COVID-19 in central Uganda.

Participants

395 nurses.

Main outcome measures

Burnout scores.

Results

Of the total 395 participants, 65.1% (n=257) were female; 40% (n=158) had a diploma; 47.1% (n=186) were single; and 39.2% (n=155) had worked for 11–15 years. The results show that 40% (n=158), 41.77% (n=165) and 18.23% (n=77) reported high, average and low levels of burnout, respectively. The results show that the predictors of nurses’ burnout were personal protective equipment (PPE) (OR: 7.1, 95% CI 4.08 to 12.31) and increased workload (OR 4.3, 95% CI 2.43 to 7.93).

Conclusion

This study of nurses working in hospitals dealing with patients with COVID-19 in central Uganda reported high rates of burnout, and it was associated with PPE and workload. Interventions like contracting new nurses to reduce workload, the WHO guidelines on PPE, adjusting working hours and ensuring hours of effective rest should be adapted.
Long-term outcome of primary intraocular lens implantation in bilateral congenital cataract in infants with a median age of 35 days at surgery: a case series
Authors: Sand Mari Kathrine , Cholidis Symira , Rimstad Kjartan , Krekling Elise Dees , Kristianslund Olav , Drolsum Liv
Published: September 2021

Objective

To evaluate the long-term visual outcome and safety after bilateral cataract surgery with primary intraocular lens (IOL) implantation in infants with visually significant cataract at birth operated before 12 weeks of age.

Methods and analysis

Medical records of infants with congenital cataract who had bilateral surgery with primary IOL implantation before 12 weeks of age at Oslo University Hospital between 2007 and 2016 were retrospectively reviewed. Fifteen infants (30 eyes) were enrolled for a prospective study examination in 2017. Corrected distance visual acuity (CDVA) and intraocular pressure (IOP) were assessed. Visual axis opacification (VAO) was defined as opacification on the anterior or posterior surface of the IOL, capsular phimosis or fibrinous membrane. Secondary glaucoma was evaluated according to international guidelines.

Results

Median age at the time of primary surgery was 35 days (range, 15 to 70 days). There were no serious intraoperative complications, and all eyes had the IOL implanted in the capsular bag. After a median follow-up of 6.1 years (range, 1.5 to 10.2 years), the CDVA was 0.5 logMAR (range, 1.2 to 0.04). All eyes had surgery for VAO and the median number of surgical procedures was 2.0 (range, 1 to 5). The cumulative incidence of secondary glaucoma was 10% after 5 years of follow-up.

Conclusion

Primary IOL implantation before 12 weeks of age gave a satisfactory visual outcome, and the incidence of secondary glaucoma was similar to that reported after primary IOL implantation in older infants. However, the risk of VAO was high.
Multidisciplinary team meetings in palliative care: an ethnographic study
Authors: Borgstrom Erica , Cohn Simon , Driessen Annelieke , Martin Jonathan , Yardley Sarah
Published: September 2021

Objectives

Multidisciplinary team meetings are a regular feature in the provision of palliative care, involving a range of professionals. Yet, their purpose and best format are not necessarily well understood or documented. This article describes how hospital and community-based palliative care multidisciplinary team meetings operate to elucidate some of their main values and offer an opportunity to share examples of good practice.

Methods

Ethnographic observations of over 70 multidisciplinary team meetings between May 2018 and January 2020 in hospital and community palliative care settings in intercity London. These observations were part of a larger study examining palliative care processes. Fieldnotes were thematically analysed.

Results

This article analyses how the meetings operated in terms of their setup, participants and general order of business. Meetings provided a space where patients, families and professionals could be cared for through regular discussions of service provision.

Conclusions

Meetings served a variety of functions. Alongside discussing the more technical, clinical and practical aspects that are formally recognised aspects of the meetings, an additional core value was enabling affectual aspects of dealing with people who are dying to be acknowledged and processed collectively. Insight into how the meetings are structured and operate offer input for future practice.
Rotated twisted-mass: a convenient regularization scheme for isospin breaking QCD and QED lattice calculations
Authors: Frezzotti R. , Gagliardi G. , Lubicz V. , Sanfilippo F. , Simula S.
Published: September 2021

We propose a scheme of lattice twisted-mass fermion regularization which is particularly convenient for application to isospin breaking (IB) QCD and QED calculations, based in particular on the so called RM123 approach, in which the IB terms of the action are treated as a perturbation. The main, practical advantage of this scheme is that it allows the calculation of IB effects on some mesonic observables, like e.g. the$$\pi ^+ - \pi ^0$$π+-π0mass splitting, using lattice correlation functions in which the quark and antiquark fields in the meson are regularized with opposite values of the Wilson parameterr. These correlation functions are found to be affected by much smaller statistical fluctuations, with respect to the analogous functions in which quark and antiquark fields are regularized with the same value ofr. Two numerical application of this scheme, that we callrotated twisted-mass, within pure QCD and QCD + QED respectively, are also provided for illustration.
Ellis wormholes in anti-de Sitter space
Authors: Blázquez-Salcedo Jose Luis , Chew Xiao Yan , Kunz Jutta , Yeom Dong-han
Published: September 2021

We construct traversable wormholes with anti-de Sitter asymptotics supported by a phantom field. These wormholes are massless and symmetric with respect to reflection of the radial coordinate $$\eta \rightarrow - \eta $$

η
→
-
η

. Their circumferential radius decreases monotonically from radial infinity to their single throat. Analogous to their asymptotically flat counterparts, these anti-de Sitter wormholes possess an unstable radial mode.
Large eddy simulation of converging Richtmyer–Meshkov instability based on subgrid-scale dissipation similar method
Authors: Zhou Hao , Feng Qijing , Hao Pengcheng , He Zhiwei , Li Li
Published: September 2021

This paper focuses on large eddy simulation of the Richtmyer–Meshkov instability (RMI) in spherical and cylindrical converging geometries with a Mach number [Formula: see text] based on subgrid-scale (SGS) dissipation similar method (SDSM). Based on the converging RMI problem, we obtain from a priori test and theoretical analysis that the suggested method can provide accurate structural correlation while ensuring the computational stability. Comparing the numerical simulation results with direct numerical simulation (DNS) and existing model in converging RMI problem, we could find that the suggested method overcomes some defects of the existing model, such as the Smagorinsky model cannot predict transition accurately and the helicity model can only predicts the quasi-two-dimensional flow precisely. It provides a beneficial tool for the research of converging RMI.
Shadow of a noncommutative-inspired Einstein–Euler–Heisenberg black hole
Authors: Maceda Marco , Macias Alfredo , Martinez-Carbajal Daniel
Published: September 2021

We consider the orbits of test particles moving in the gravitational field of a noncommutative-inspired Einstein–Euler–Heisenberg black hole. Using the geometric metric, we determine the circular orbits followed by massless particles, comparing them with the circular photon orbits coming from the Plebanski pseudo-metric that takes into account the nonlinear nature of the Euler–Heisenberg electrodynamics. Using the impact parameter of the photon orbits, we define the shadow of the noncommutative-inspired black hole and discuss the constraints on the model by comparing its shadow with the prediction from General Relativity.
STABILITY ANALYSIS OF A SEIQRS EPIDEMIC MODEL ON THE FINITE SCALE-FREE NETWORK
Authors: LIU XIA , ZHAO KUN , WANG JUNLI , CHEN HUATAO
Published: September 2021

Taking into account the quarantine for an infectious disease, a susceptible-exposed-infected-quarantined-recovery-susceptible (SEIQRS) epidemic model with time delay on the finite scale-free network is given. The basic reproduction number [Formula: see text], which is dependent not only on all kinds of transfer rates, but also on the topology of the network, is derived. By constructing the Lyapunov function, it is asserted that the disease-free equilibrium of system is locally asymptotically stable if [Formula: see text], moreover, disease-free equilibrium of system is globally asymptotically stable when [Formula: see text]. In addition, the influence of network nodes on the spread of diseases is discussed. Finally, the theoretical results are verified by corresponding numerical simulation.
ADOPTION OF FRACTIONAL DIFFERENTIAL EQUATIONS UNDER IMPROVED VARIATIONAL ITERATIVE ALGORITHM COMBINED WITH DNA CODING ALGORITHM IN IMAGE ENCRYPTION
Authors: LI XU , KATEB FARIS , WU SHAOFEI
Published: September 2021

To explore the application of improved variational iterative method in solving fractional differential equations and the effect of DNA coding algorithm based on logistic chaos mapping in image encryption, combining Chebyshev polynomial with variational iterative method, a new algorithm for solving fractional differential equations is proposed. In order to solve the initial value problem, the simulation software is used to compare the approximate solution after the change of values of [Formula: see text] and [Formula: see text] in the solution process to investigate the influence of different parameters on the accuracy of fractional order system. Subsequently, the logistic chaos sequence is used to generate discrete binary sequences, and an image encryption algorithm based on DNA coding is proposed. In order to verify the encryption performance of the proposed algorithm, Matlab simulation software is used to simulate and verify the image encryption processing. The results show that when [Formula: see text] approaches 1, the solution is closer to the exact solution than that when [Formula: see text] approaches 0.5, 0.7, and 0.9; compared with 1, 3, 5, and 7, the constructed algorithm has the highest accuracy when [Formula: see text] value is 9. The simulation results of the fuzzy partial fractional order system show that the chaotic sequence is sensitive to the initial value, and the logistic mapping sequence is suitable for the information encryption of the secure communication system. The simulation results of the image encryption algorithm based on DNA coding show that the algorithm can effectively encrypt the image, and the image histogram after encryption is approximately a horizontal line; slight changes in the initial value will affect the decryption effect of the image; the correlation analysis results show that there is no correlation between adjacent pixels in the image after encryption, which indicates that combining Chebyshev polynomials with variational iteration method can reduce the computational burden and improve the computational accuracy, and the image encryption algorithm proposed in this study can improve the reliability and security of image encryption.
FINANCING RISK MANAGEMENT AND CONTROL FOR HIGH-TECHNOLOGICAL SMALL AND MEDIUM ENTERPRISES — UNDER NONLINEAR DIFFERENTIAL EQUATION
Authors: LI XIMEI , CHEN JING , OQAIBI HADI , FAN XIANGMEI
Published: September 2021

In this paper, a financing decision-making method is proposed based on the nonlinear differential equations (NDEs) to promote the healthy development of high-technological (high-tech) small and medium enterprises (SMEs). An assessment index system for financing risks is established, and the financing decision-making method is proposed based on the backward stochastic differential equation (BSDE). Then, the financing risk is evaluated with analytic hierarchy process (AHP) combined with fuzzy evaluation based on the financing status of Peilin Company. Finally, the corresponding financing decision is proposed based on the BSDE. It is found that the comprehensive score of financing risk of Peilin Company is 63.6124, indicating that the risk is high. The financing decision obtained shows that the current equity fund financing should be 396.24[Formula: see text]million to achieve the future goal. It is proved that the proposed financing risk evaluation method can assess the financing risks accurately, and the financing decision-making method based on NDE can obtain more appropriate financing decisions through calculation. This study can provide a crucial reference for management and control of financing risk for enterprises.
STEREO VISION INFORMATION SYSTEM USING MEDIAN THEOREM AND ATTITUDE COMPENSATION WITH NONLINEAR DIFFERENTIAL EQUATIONS
Authors: ZHANG YUEJIN , YIN GUANXIANG , YE MENGQIU , LIU QI , TU BOTAO , LI GUANGHUI , ZHAN AIYUN
Published: September 2021

Using computer vision technology to obtain and analyze biomechanical information is an important research direction in recent years. However, the linear model in the computer vision system cannot accurately describe the geometric relationship of the camera imaging, so it is difficult to realize human posture recognition in high-precision mechanics information. Therefore, how to improve the recognition accuracy is very important. In this paper, we apply nonlinear differential equations to stereo computer vision (SCV) information systems. And based on the median theorem, a nonlinear posture recognition and error compensation algorithm based on BP neural network is proposed to reduce the recognition error. The test set uses the Leeds Motion Pose (LSP) dataset to verify the performance of the algorithm. Experimental results show that the compensated median filter of BP neural network can eliminate glitches in attitude data. Superimposing the output attitude error compensation value with the attitude estimation value can greatly reduce the root-mean-square error of the attitude angle. The result of gesture recognition is closer to reality. Compared with traditional algorithms, the cyclomatic complexity of the proposed BP neural network algorithm has a much lower growth rate in high-order calculations, which indicates that the proposed BP neural network algorithm is more concise and scalable.
AN EMPIRICAL ANALYSIS OF THE DYNAMIC NONLINEAR RELATIONSHIP BETWEEN INBOUND TOURISM AND ECONOMIC DEVELOPMENT USING PANEL THRESHOLD REGRESSION MODEL
Authors: GENG NANA , ALKHATHLAN ALI , SHAO XIUYING
Published: September 2021

In order to further explore the important impact of inbound tourism on economic development, six cities such as X city are selected as the research objects. Based on the panel threshold regression model and relevant data, the dynamic nonlinear relationship between inbound tourism and the economic development of the tertiary industry is explored through mathematical empirical analysis. The specific research results are as follows. The inbound tourism of X city develops rapidly and is in the stage of accelerating development. Meanwhile, the development of inbound tourism in X city has a certain pulling effect on the development of related industries and the tertiary industry. Among them, the elasticity coefficients of inbound tourism in X city to transportation industry, accommodation and catering industry, wholesale and retail industry, finance and insurance industry, and real estate industry are 1.137, 1.104, 1.134, 1.105, and 1.062, respectively; the elasticity coefficient to the income of the tertiary industry is 0.436. Moreover, the analysis of the relationship between inbound tourism and the development of the tertiary industry in six cities shows that there is a dynamic nonlinear relationship between them, and the research results are in line with the expected hypothesis. The research results can provide scientific and effective reference for the follow-up study of inbound tourism and economics.
DYNAMIC NONLINEAR EXPRESSION RECOGNITION TECHNOLOGY USING NEURAL NETWORK AND ATTENTION MECHANISM
Authors: ZHANG GUANHONG , LV GANG , BINSAWAD MUHAMMAD , ODBAL H.
Published: September 2021

The purpose is to apply deep learning to facial expression recognition and improve the efficiency of facial expression recognition in real scenes: first, convolutional neural network (CNN) theoretical model is proposed. On this basis, a new CNN model is proposed, which has six learning layers, including three convolutional layers and three fully connected layers. Then, based on the shortcomings of the model, weight decay and dropout optimization methods are proposed. Moreover, the attention module is designed based on the theory of attention mechanism. After each convolutional layer, a hybrid attention module (channel domain attention and spatial domain attention) is added. Finally, the frame error rate (FER) 2013 dataset and Cohn–Kanade (CK)+ dataset are used to test and compare the performance of the model. The results show that after 50Epoch, the accuracy rate of the original model fluctuates greatly in the process of convergence; however, after attention mechanism is added, the fluctuation of the accuracy of the model is obviously reduced. In the CK+ dataset, the accuracy of each model is maintained at about 95%, while the accuracy of FER2013 dataset is about 71%. After attention mechanism is added, the recognition rate of dynamic nonlinear expression is higher than that of basic model. The recognition rate of the original model and the optimized model with attention mechanism for the dynamic nonlinear expression with occlusion decreases in varying degrees, but the reduction of the recognition rate of the latter is alleviated.
MULTI-FACTOR STATUS PREDICTION BY 4D FRACTAL CNN BASED ON REMOTE SENSING IMAGES
Authors: WANG LI , WANG XIAOYI , ZHAO ZHIYAO , WU YUXI , XU JIPING , ZHANG HUIYAN , YU JIABIN , SUN QIAN , BAI YUTING
Published: September 2021

With the acceleration of industrialization and urbanization, most lakes and reservoirs have been in eutrophication state. Eutrophication of water body will produce a series of environmental problems, among which cyanobacteria bloom is one of the most studied and seriously polluted problems. It is of great significance to effectively control the occurrence of cyanobacteria blooms by predicting and simulating the outbreak process of cyanobacteria blooms and accurately forecasting the relevant governance departments. However, there are two problems in the existing analysis of algal blooms: on the one hand, it is difficult to consider the impact of other factors on cyanobacteria blooms by taking chlorophyll concentration as the main influencing factor, and it is also unable to determine the relationship between various factors. On the other hand, only based on the field monitoring data research, lack of comprehensive analysis of the whole water area. The remote sensing image can reflect the change of the whole water area, but the traditional analysis method is difficult to deal with the massive remote sensing data effectively. In this study, eutrophication level was used as characterization index of cyanobacteria bloom, and the remote sensing image and its inversion map were taken as the main research data, and a new method of cyanobacteria bloom prediction based on four-dimensional (4D) fractal CNN was proposed. The prediction model uses 4D fractal CNN to extract the features of multi factor remote sensing images, capture the temporal and spatial characteristics and the interaction between multiple factors, and predict the eutrophication level of water body. In this study, a total of 216 remote sensing images of Taihu Lake Basin were selected from 29 groups with fine weather from 2009 to 2010 obtained by MODIS satellite. The simulation results show that the method proposed in this paper has excellent prediction performance, and the accuracy rate of 85.71% is better than that of common 3D CNN and 4D CNN models.
DIFFERENTIAL OPTIMAL INVESTMENT TIMING DECISION MODEL FOR NONLINEAR DYNAMIC URBAN INFRASTRUCTURE PLANNING SYSTEM
Authors: JIANG QI-JIE , XU XIN-YING , SABBAN AHMAD MADANI , YIN CHUAN-BIN
Published: September 2021

With the acceleration development of urbanization, the infrastructure construction plays an increasingly crucial role in the expansion process of cities. However, the existing decision-making methods of urban infrastructure investment still stay at the static level, resulting in a huge waste of resources, which does not meet the needs of dynamic urban development and management. Based on geometric Brownian motion, option function and the theory of real option, this paper establishes a dynamic differential optimal investment opportunity decision model applied to urban infrastructure construction. An example was then conducted to test the operability and application of the proposed model. The results confirm that the proposed approach contributes to improving the scientificity of urban infrastructure planning and construction, and realizing the maximization of infrastructure’s social value. Meanwhile, this paper contributes to promoting the development of city infrastructure investment decision-making methods from static to dynamic, and from partial to overall.
DEFAULTABLE TERM STRUCTURES DRIVEN BY SEMIMARTINGALES
Authors: GÜMBEL SANDRINE , SCHMIDT THORSTEN
Published: September 2021

In this paper, we consider a market with a term structure of credit risky bonds in the single-name case. We aim at minimal assumptions extending existing results in this direction: first, the random field of forward rates is driven by a general semimartingale. Second, the Heath–Jarrow–Morton (HJM) approach is extended with an additional component capturing those future jumps in the term structure which are visible from the current time. Third, the associated recovery scheme is as general as possible, it is only assumed to be nonincreasing. In this general setting, we derive generalized drift conditions which characterize when a given measure is a local martingale measure, thus yielding no asymptotic free lunch with vanishing risk (NAFLVR), the right notion for this large financial market to be free of arbitrage.
Vector Form Intrinsic Finite Element Method for Stochastic Analysis of Train–Track–Bridge Coupling System
Authors: Wang Su-Mei , Ni Yi-Qing , Duan Yuan-Feng , Yau Jong-Dar
Published: September 2021

In this paper, a train–track–bridge (TTB) interaction model that can account for coach-coupler effect is presented for stochastic dynamic analysis of a train traveling over a bridge. Based on the vector form intrinsic finite element (VFIFE) method, both the bridge and non-ballasted track are discretized into a set of mass particles connected by massless beam elements, in which the fasteners that fixed the tracks on the bridge deck are modeled as a series of linear spring-dashpot units. The multi-body train car is regarded as seven mass particles (1 for car body, 2 for bogies and 4 for wheelsets) connected by parallel spring-dashpot units. Considering the random nature of rail irregularities, the Karhunen–Loéve expansion (KLE) method is used to simulate the vertical profile of the tracks. To calculate the mean and standard deviation of the stochastic response of the TTB system, the point estimated method (PEM) based on the Gaussian integration and dimension reduction method is adopted. The proposed VFIFE–TTB interaction model is then applied to stochastic resonance analyses of a train moving on a bridge. It is shown that the present VFIFE–TTB model is able to analyze the dynamic interaction of the TTB system simply and efficiently. The influence of rail irregularity-induced stochastic vibration on the train and bridge would become significant once the resonant vibration takes place on the TTB system.
Stability of Excited Exciton States in Semiconductor Quantum Dots Under a Lateral Electric Field
Authors: Safwan S. A. , El Meshad Nagwa
Published: September 2021

The effect of the lateral electric field (LEF) on the excited and ground state stability of an exciton ([Formula: see text]) confined in a parabolic cylindrical quantum dot (QD) was estimated in this study. The calculation was performed in the framework of single-band effective mass theory using a variational approach. Our results revealed that the ground state binding energy of [Formula: see text] decreases with increasing the cylindrical QD radius until the exciton stability is lost at moderate LEF strength. By increasing the LEF strength, the excited heavy-hole ([Formula: see text]) can create an excited state [Formula: see text] or excited state [Formula: see text] of [Formula: see text], and the results indicate that the first state is more stable. In contrast, when an excited electron ([Formula: see text]) combines with an excited hole ([Formula: see text]) or unexcited hole ([Formula: see text]), it contains no split excited states for [Formula: see text] with less binding energy than the state [Formula: see text]. Comparing our previous results of donor impurity [Formula: see text] with [Formula: see text], we found that [Formula: see text] has a more stable ground state than [Formula: see text]. Moreover, the excited [Formula: see text] states are more stable than the excited states of [Formula: see text]. The quantum Stark shift (QSS) of the light- and heavy-hole exciton energy was explored, and a blue-shifted and quadratic QSS was observed. In contrast, for single particles (electron, heavy-hole and light hole), a red-shifted and linear QSS was observed.
Mining of structural motifs in proteins using artificial bee colony optimization framework for druggability
Authors: Suma L. S. , Vinod Chandra S. S.
Published: September 2021

In this work, we have developed an optimization framework for digging out common structural patterns inherent in DNA binding proteins. A novel variant of the artificial bee colony optimization algorithm is proposed to improve the exploitation process. Experiments on four benchmark objective functions for different dimensions proved the speedier convergence of the algorithm. Also, it has generated optimum features of Helix Turn Helix structural pattern based on the objective function defined with occurrence count on secondary structure. The proposed algorithm outperformed the compared methods in convergence speed and the quality of generated motif features. The motif locations obtained using the derived common pattern are compared with the results of two other motif detection tools. 92% of tested proteins have produced matching locations with the results of the compared methods. The performance of the approach was analyzed with various measures and observed higher sensitivity, specificity and area under the curve values. A novel strategy for druggability finding by docking studies, targeting the motif locations is also discussed.
Cosmological models of generalized ghost pilgrim dark energy (GGPDE) in the gravitation theory of Saez–Ballester
Authors: Garg Priyanka , Dixit Archana , Pradhan Anirudh
Published: September 2021

In this paper, we study the mechanism of the cosmic model in the presence of generalized ghost pilgrim dark energy (GGPDE) and matter in locally rotationally symmetric (LRS) Bianchi type-I space-time by the utilization of new holographic DE in Saez–Ballester theory. Here, we discuss all the data for three scenarios, the first is supernovae type-Ia union data, the second is SN Ia data in combination with baryon acoustic oscillation and cosmic microwave background observations and the third is a combination with observational Hubble data and joint light-curve analysis observations. From this, we get a model of our universe, where transit state exists from deceleration to acceleration phase. Here, we have observed that the results yielded by cosmological parameters like [Formula: see text] (energy density), equation of state [Formula: see text], squared speed of sound [Formula: see text] and [Formula: see text]–[Formula: see text] are compatible with the recent observations. The [Formula: see text]–[Formula: see text] trajectories lie in both thawing and freezing regions and the correspondence of the quintessence field with GGPDE is also discussed. Some physical aspects of the GGPDE models are mainly highlighted.
Risk and Ambiguity in Turbulent Times
Authors: Brenner Menachem , Izhakian Yehuda
Published: September 2021

This paper focuses on the 2008–2020 period during which two major crises, affecting the economy and the financial markets, occurred. Between 2008 and 2020, there were less extreme tail events, including the lingering Eurozone and Greece crises. In particular, after extremely high stock market volatility and volatility of volatility (VoV) during 2008, the long-run average volatility declined to about 20% and the VoV to around 100%. This paper analyzes this period through the lens of risk and ambiguity (uncertainty). It aims to address the question: what are the financial markets that trade risk — the volatility derivatives markets — telling us? To this end, this paper uses several measures of uncertainty. It reviews the history of volatility and uncertainty measures and discusses their informativeness. It then discusses the information derived from volatility derivatives.
Credit Transition and Structural Shocks
Authors: Ferretti Camilla , Gabbi Giampaolo , Ganugi Piero , Vozzella Pietro
Published: September 2021

Credit risk involves not only the complexity of screening but also monitoring and estimating rating transition. The adoption of inadequate transition matrices causes a misevaluation of credit risk, a consequent misallocation of capital, with the prospect that the lending process will be affected by increasing transaction costs and limited rationality, especially after a shock. Comparing the mover–stayer and the Markov chain approaches to estimate the SME rating transition matrix, we find that the risk of a structural credit shock imposes flexible estimates not constrained by the long-run trajectory of borrowers. Improved migration estimation mitigates adverse selection in banks’ lending behavior. This conclusion is particularly true during economic downturns with the consequence of reducing the cyclicality and empowering the resilience of banks.
A New Quest for Self-Reliance: East Asia and Indian Economic Nationalism
Authors: CHACKO PRIYA
Published: September 2021

Since 2017, India has introduced an increasing number of protectionist economic policies including higher tariffs, import duties and production subsidies while also rejecting and reviewing free trade agreements and imposing new regulations on foreign companies. This paper seeks to make sense of India’s recent foreign economic policies and their potential impact on its relations with East Asia. It does so by analyzing the economic, political and geopolitical drivers of these policy changes and placing their emergence within a broader historical context. It is argued that India is entering a new period of “neo-mercantilist” economic nationalism that simultaneously seeks to protect and nurture industries while attracting foreign investment and integrating India into global value chains. This is the outcome of the consequences of “liberal” economic nationalist policies and a changing geopolitical environment — including a broader global impetus toward neo-mercantilist policies and conflict with China. The COVID-19 pandemic has intensified this pre-existing turn toward neo-mercantilism. India’s new economic nationalism has the potential to produce significant changes in India’s relations with East Asia but also faces significant challenges in its implementation in the post-COVID era.