bluuebunny/crossref_metadata_2025 huggingface dataset:
Bibliometric analysis of research hotspots and development trends in selective fetal reduction
Authors: Meng Yi L. , Ren Li J. , Yin Shao W.
Published: February 2021

Aim

To evaluate the theme trends and knowledge structure of multifetal pregnancy reduction (MPR)‐related literature by using bibliometric analysis.

Methods

Published scientific papers regarding MPR were retrieved from the PubMed database. Data extraction and statistics were conducted using Bibliographic Item Co‐Occurrence Matrix Builder (BICOMB). Furthermore, gCLUTO software was used in the study for bi‐clustering analysis and strategic diagram analysis.

Results

According to the search strategy, 906 total papers were included. Among all the extracted MeSH terms, 41 high frequency ones were identified and hotspots were clustered into four categories. In the strategic diagram, research on intrauterine treatment of MPR was most well developed. In contrast, statistical data on the sequelae of fetal reduction surgery and applications of MPR in assisted reproductive technologies were relatively immature.

Conclusion

The analysis of common terms among the high‐frequency network terms in multiparous pregnancy reduction can help researchers and clinicians understand the hotspots, key topics, and issues to be discovered on MPR. Research on intrauterine treatment of MPR was most well developed.
Quality improvement initiative to improve the duration of kangaroo mother care for twin preterm neonates born at a tertiary care hospital in resource‐limited settings
Authors: Arora Pihu , Kommalur Anitha , Devadas Sahana , Kariyappa Mallesh , Rao Suman P N
Published: February 2021

Aim

Kangaroo mother care (KMC) can be challenging in multiple births and more so in resource‐limited settings. This study aims at increasing the mean duration of KMC with early initiation in twin preterm neonates born at a tertiary care hospital using a quality improvement (QI) initiative.

Methods

Barriers for poor KMC practice in twin preterm neonates born at the tertiary care hospital were analysed and baseline data were collected over a period of 4 months using a predesigned proforma. A QI team was formed and suggested solutions were prioritised through focus group discussions in the form of Plan‐Do‐Study‐Act (P‐D‐S‐A) cycles. Each cycle was of one‐month duration and three cycles were implemented, followed by the sustenance phase studied at 1‐month post‐implementation.

Results

There were a total of 238 twin deliveries in the study period, of which 169 twin pairs were included in the study. At the end of implementation, the average day of initiation of KMC improved from 8th to 3rd day of life and the duration of KMC increased significantly from an average of 2.70 h/infant/day to 7.88 h/infant/day.

Conclusion

This QI project focused on the improvement of KMC practice in twin preterm neonates in a tertiary care hospital where results were achieved with maximal utilisation of available hospital resources and low‐cost interventions. This study design is generalizable to other hospitals in resource‐limited settings where family participatory care can be strengthened to overcome the challenges of KMC in multiple births.
Computer tomography‐assisted visualization of the movement triggered by frost in Ostrinia nubilalis overwintering in maize stalks
Authors: Keszthelyi Sándor , Binder Antal , Csóka Ádám , Pónya Zsolt , Donkó Tamás
Published: February 2021

The damage of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), causes is mainly determined by the success of its overwintering. The aim of our study was to assess the consequences of the artificial cooling on the movement and survival ability of overwintering larvae of O. nubilalis by using computer‐assisted tomography. The in situ movement of the examined larvae in icy media of different thickness (5, 15, and 30 cm) and during freezing periods of 5, 10, 20, 40, and 60 min was determined in maize stalks using CT and the positioner‐laser of the CT apparatus. It has been found that the thickness of the ice had a significant effect on the displacement of the overwintering larvae, however, the impact of the duration of freezing on the moving of the larvae could not be proven statistically. Enhanced larvae activity due to thinner ice layers (5, 15 cm) were of exponential type, which was more pronounced just prior to the freezing point. In contrast, thicker ice covering (30 cm) caused complete immobility. According to our results, the diapausing larvae were still able to move and albeit it appeared to be capable of surviving the direct impact of extreme cold, it could even leave its overwintering place as a result of low temperature. Furthermore, the maize stalk tissue contributes to the survival‐success of the larvae as it seems to act as a temperature‐buffer moderating the severe impact that low temperature exerts on living tissue.
Discrimination against the elderly in health‐care services: a systematic review
Authors: Saif‐Ur‐Rahman KM , Mamun Razib , Eriksson Erik , He Yupeng , Hirakawa Yoshihisa
Published: February 2021

Ageism in health‐care services is a cardinal public health concern in geriatric health. It is important to know the types and extent of discrimination experienced by elderly individuals while seeking health care. This systematic review aimed to explore the available research to identify discrimination of elderly individuals in health‐care services. MEDLINE through PubMed, Web of Science, PsycInfo, and Cochrane Database were searched by using a comprehensive search strategy in September 2020 with no limitation in the year of publication and types of publication. Articles published in English focusing on disparities in health‐care service among the elderly were included. Two independent authors screened, extracted, and assessed the quality of data using the Joanna Briggs Institute Critical Appraisal Tool. A narrative synthesis was conducted followed by qualitative content analysis to identify themes from the extracted outcomes of the included studies. Of 3117 articles retrieved from the initial search, 21 articles were included. A total of 611 608 participants from 38 countries in four geographic regions were reported. Articles were published between 2003 and 2020. Most of the studies (n = 19) were cross‐sectional in design, and the remaining two studies were qualitative. Major themes of discrimination were age‐related discrimination, racial discrimination, gender discrimination, wealth‐related discrimination, and technology‐related discrimination. This systematic review identified the major perspectives on disparities faced by the elderly in accessing health services. There is a huge research gap on this issue. Specific strategies should be incorporated to address the varying types of discrimination experienced by elderly individuals.
Explicit and Implicit Hopelessness and Self‐injury
Authors: Gray Nicola Susan , Knowles James , George Danielle , Harvey Alex , Powell Rachel , Zadeh Mehrnaz Vazirian , Wansing Carlotta , Snowden Robert J.
Published: February 2021

Objective

This study examined the relationship between explicit and implicit measures of hopelessness and self‐injurious behavior (defined here as self‐harming or suicidal actions and thoughts).

Method

A community sample of 267 participants completed explicit measures of hopelessness (Beck's Hopelessness Scale and a Feeling Thermometer), an implicit measure of hopelessness (Hopelessness Implicit Association Test), and a self‐report measure of their history of self‐injurious behavior.

Results

The results showed that high levels of hopelessness, measured both explicitly or implicitly, were associated with a past and recent history of self‐injury. However, there was also an interaction between the implicit and explicit measures such that explicit hopelessness was more strongly predictive of self‐injury in people with high levels of implicit hopelessness.

Conclusion

The findings show that the implicit measurement of hopelessness can help predict past and recent self‐injury beyond what explicit measures of hopelessness currently achieve and could be used in the assessment of risk of both self‐harming and suicidal behaviors.
MATRA‐A: A study on massive transfusion
Authors: Ünlü Aytekin , Yılmaz Soner , Akbasli Izzet Turkalp , Karaagac Akyol Tulay , Akkapulu Nezih , Tumer Murat , Ertugrul Oruc Nigar , Balas Sener , Goral Seniz , Topcuoglu Pervin , Tanriseven Mustafa , Sayin Selim , Eryilmaz Mehmet
Published: February 2021

Background

We use massive transfusion in various clinical conditions and it is associated with high mortality. Although some massive transfusion protocols improve patient outcomes, the clinical circumstances requiring it are not well defined.

Methods

MATRA‐A is a multicenter retrospective study. Six University and Training Research Hospitals in Ankara participated in the study. We collected clinical data on patients (>18 years) who received massive transfusions (≥10 units/24 h) from 2017 through 2019.

Results

Overall, 167 (0·27% of transfused patients) received a massive transfusion of 2586 units of red blood cells (1·5% of total RBCs transfused). The median interquartile range values for RBCs, fresh frozen plasma (FFP) and platelets were 13 (11–176), 16 (9–33) and 4 (0–11), respectively. Surgical patients received 90% of massive transfusions. The most common clinical indications for massive transfusion were cardiovascular diseases (42·6%), trauma (20·3%) and malignancies (11%). FFP: RBC: Platelets ratio was 1·9:1:0·5. The overall and trauma‐related mortality rates were 57·4% and 61·8%, respectively. The hospital mortality rates of trauma patients that received high vs. low ratio (FFP: RBCs > 1:1·5 vs. ≤1:1·5) transfusions were 47·6% and 86·6% and the difference was statistically significant (P = 0·03).

Conclusion

Cardiovascular diseases and trauma occasion are the most common causes of massive transfusion. It is infrequent in clinical settings and is associated with high mortality rates. Additionally, in massively transfused trauma patients, a high FFP:RBCs ratio seems to be associated with increased survival. Focused prospective studies are required to define the areas that need improvement on a national scale.
Amlodipine as adjuvant therapy to current chelating agents for reducing iron overload in thalassaemia major: a systematic review, meta‐analysis and simulation of future studies
Authors: Elfaituri Muhammed Khaled , Ghozy Sherief , Ebied Amr , Morra Mostafa Ebraheem , Hassan Osama Gamal , Alhusseiny Ahmed , Abbas Alzhraa Salah , Sherif Nourin Ali , Fernandes Juliano Lara , Huy Nguyen Tien
Published: February 2021

Background and Objectives

Iron overload in thalassaemia is a crucial prognostic factor and a major cause of death due to heart failure or arrhythmia. Therefore, previous research has recommended amlodipine as an auxiliary treatment to current chelating agents for reducing iron overload in thalassaemia patients.

Materials and Methods

A systematic review and meta‐analysis of the results of three randomized clinical trials evaluating the use of amlodipine in thalassaemia patients through 12 databases were carried out.

Results

Our final cohort included 130 patients. Insignificant difference in decreasing liver iron concentrations was found between amlodipine and control groups {weighted mean difference = −0·2, [95% confidence interval = (−0·55–0·15), P = 0·26]}. As regards serum ferritin, our analysis also showed no significant difference in serum ferritin between amlodipine and control groups {weighted mean difference [95% confidence interval = −0·16 (−0·51–0·19), P = 0·36]}. Similarly, there was insignificant difference in cardiac T2* between amlodipine and control groups {weighted mean difference [95% confidence interval = 0·34 (−0·01–0·69), P = 0·06]}.

Conclusions

Despite the growing evidence supporting the role of amlodipine in reducing iron overload in thalassaemia patients, our meta‐analysis did not find that evidence collectively significant. The results of our simulation suggest that when more data are available, a meta‐analysis with more randomized clinical trials could provide more conclusive insights.
Aero-Thermal Aspects of Film Cooled Nozzle Guide Vane Endwall—Part 1: Aerodynamics
Authors: Alqefl Mahmood H. , Nawathe Kedar P. , Chen Pingting , Zhu Rui , Kim Yong W. , Simon Terrence W.
Published: February 2021

The first-stage turbine of a modern gas turbine is subjected to high thermal loads which lead to a need for aggressive cooling schemes to protect its components from melting. Endwalls are particularly challenging to cool due to the complex system of secondary flows near them that wash the protective film coolants into the mainstream. This paper shows that without including combustor cooling, the complex secondary flow physics is not representative of modern engines. Aggressive injection of all cooling flows upstream of the passage is expected to interact and change passage aerodynamics and, subsequently, mixing and transport of coolants. This study describes, experimentally, the aero-thermal interaction of cooling flows near the endwall of a first-stage nozzle guide vane passage. The test section involves an engine-representative combustor–turbine interface geometry, combustor coolant flow, and endwall film cooling flow injected upstream of a linear cascade. The approach flow conditions represent flow exiting a cooled, low-NOx combustor. This first part of this two-part study aims to understand the complex aerodynamics near the endwall through detailed measurements of passage three-dimensional velocity fields with and without endwall film cooling. The aerodynamic measurements reveal a dominant vortex in the passage, named here as the Impingement Vortex, that opposes the passage vortex formed at the airfoil leading edge plane. This Impingement Vortex completely changes our description of flow over a modern film cooled endwall.
Jurassic evolution of the Qaidam Basin in western China: Constrained by stratigraphic succession, detrital zircon U-Pb geochronology and Hf isotope analysis
Authors: Qian Tao , Wang Zongxiu , Wang Yu , Liu Shaofeng , Gao Wanli , Li Wangpeng
Published: February 2021

The formation and evolution of an intracontinental basin triggered via the subduction or collision of plates at continental margins can record intracontinental tectonic processes. As a typical intracontinental basin during the Jurassic, the Qaidam Basin in western China records how this extensional basin formed and evolved in response to distant subduction or collisional processes and tectonism caused by stresses transmitted from distant convergent plate margins. The Jurassic evolution of the Qaidam Basin, in terms of basin-filling architecture, sediment dispersal pattern and basin properties, remains speculative; hence, these uncertainties need to be revisited. An integrated study of the stratigraphic succession, conglomerates, U-Pb geochronology, and Hf isotopes of detrital zircons was adopted to elucidate the Jurassic evolutionary process of the Qaidam Basin. The results show that a discrete Jurassic terrestrial succession characterized by alluvial fan, braided stream, braided river delta, and lacustrine deposits developed on the western and northern margins of the Qaidam Basin. The stratigraphic succession, U-Pb age dating, and Hf isotope analysis, along with the reconstructed provenance results, suggest small-scale distribution of Lower Jurassic sediments deposited via autochthonous sedimentation on the western margin of the basin, with material mainly originating from the Altyn Tagh Range. Lower Jurassic sediments in the western segment of the northern basin were shed from the Qilian Range (especially the South Qilian) and Eastern Kunlun Range. And coeval sediments in the eastern segment of the northern basin were originated from the Quanji massif. During the Middle-Late Jurassic, the primary source areas were the Qilian Range and Eastern Kunlun Range, which fed material to the whole basin. The Jurassic sedimentary environment in the Qaidam Basin evolved from a series of small-scale, scattered, and rift-related depressions distributed on the western and northern margins during the Early Jurassic to a larger, extensive, and unified depression occupying the whole basin in the Middle Jurassic. The Altyn Tagh Range rose to a certain extent during the Early Jurassic but lacked large-scale strike-slip tectonism throughout the Jurassic. At that time, the North Qaidam tectonic belt had not yet been uplifted and did not shed material into the basin during the Jurassic. The Qaidam Basin experienced intracontinental extensional tectonism with a northeast-southwest trend throughout the Jurassic in response to far-field effects driven by the sequential northward or northeastward amalgamation of blocks to the southern margin of the Qaidam Block and successive accretion of the Qiangtang Block and Lhasa Block onto the southern Eurasian margin during the Late Triassic−Early Jurassic and Late Jurassic−Early Cretaceous, respectively.
Pulmonary artery sarcoma masquerading as a pulmonary embolism
Authors: Gnanalingam Chevanthy , Wright Matthew , Ahmed Yasser
Published: February 2021

A 52-year-old woman was referred to the respiratory team with worsening shortness of breath for the last 3 months, which had deteriorated significantly over the last 2–3 weeks. She underwent a CT pulmonary angiogram, which was reported locally as showing a large pulmonary embolism. Given the chronic history and appearance of the thrombus, the patient was referred to a specialist pulmonary vascular disease multidisciplinary team and underwent a PET-CT scan with the diagnosis being felt to be more consistent with a pulmonary artery sarcoma. Within 4 weeks, she underwent a pulmonary endarterectomy which confirmed the presence of an extensive mass. She underwent bilateral endarterectomy and pulmonary artery valve replacement, with subsequent improvement of her breathlessness back to premorbid baseline. Postoperative histology has confirmed a pulmonary artery angiosarcoma. Alternate imaging modalities and early referral to a specialist unit allowed as early a diagnosis as possible with good symptomatic benefit.
Lawsonella clevelandensis: an emerging cause of vascular graft infection
Authors: Ramesh Rommel , Assi Mariam , Esquer Garrigos Zerelda , Sohail Muhammad Rizwan
Published: February 2021

Lawsonella clevelandensis,an emerging pathogen, was first described in 2016, and has been implicated in abdominal, breast and spinal abscesses in a limited number of cases. Being a fastidious organism, it is primarily identified with molecular methods. With the incorporation of broad-range PCR testing in clinical diagnostics,L. clevelandensishas been increasingly reported in the literature. We describe a case of a 65-year-old man who presented with bilateral psoas abscesses secondary to aorto-bi-iliac vascular graft infection withL. clevelandensisidentified using 16S rRNA/PCR sequencing. The patient underwent surgical resection and replacement of infected graft, followed by 6 weeks of intravenous antibiotic therapy and then chronic suppression with doxycycline and cefadroxil. He was infection-free at last follow-up.
Carfilzomib-induced atypical haemolytic uraemic syndrome: a diagnostic challenge and therapeutic success
Authors: Darwin Alicia , Malpica Leonger , Dhanoa Jugraj , Hashmi Hamza
Published: February 2021

Haemolytic uraemic syndrome (HUS) is a thrombotic microangiopathy (TMA) that presents with renal insufficiency, thrombocytopaenia and microangiopathic haemolytic anaemia. Typical HUS is associated with Shiga toxin while atypical HUS (aHUS) is due to overactivation of the alternative complement pathway. aHUS has numerous causes, including drugs, with rare reports of carfilzomib, a proteasome inhibitor used in multiple myeloma, as causative agent. Cases vary in presentation, presenting a diagnostic challenge. Historically, TMAs were treated with plasma exchange. aHUS, however, is considered refractory to plasma exchange and best treated with eculizumab, a monoclonal antibody targeting C5, a terminal complement protein. We report a patient with history of multiple myeloma who presented with headaches, elevated blood pressure, petechiae, ecchymosis and haemolytic anaemia. His condition was determined to be carfilzomib-induced aHUS and he was successfully treated with eculizumab. Early detection and treatment of drug-induced aHUS is vital in reducing morbidity and mortality related to the condition.
The ‘nightstick’ ischial fracture: a unique oddity of the pelvic injury family
Authors: Gillespie Matthew John , Makaram Navnit S , White Tim O , Molyneux Samuel G
Published: February 2021

We present an unusual ischial fracture unreported in the literature. We discuss the mechanism and describe the appropriate investigations and surgical management of this fracture. A 36-year-old man sustained a direct blow to his right buttock following a fall from a dirt bike. Examination revealed a firm haematoma, with severe pain on any stretch involving the posterior compartment of the thigh. Radiographs revealed a displaced fracture of the ischial body. CT confirmed integrity of the pelvic ring. The patient underwent open reduction and internal fixation with a partially threaded cannulated screw via a ‘modified longitudinal’ posterior approach to the ischium. The patient was managed partially weight-bearing for 6 weeks; 6-month follow-up confirmed satisfactory clinical and radiographic outcomes. Clinicians should be aware of this novel pelvic fracture and its unusual presentation, currently not included in any pelvic fracture classification system. We report a novel operative technique for appropriate surgical management of such injuries.
Peer-Assisted Lifestyle (PAL) intervention: a protocol of a cluster-randomised controlled trial of a health-coaching intervention delivered by veteran peers to improve obesity treatment in primary care
Authors: Wittleder Sandra , Smith Shea , Wang Binhuan , Beasley Jeannette M , Orstad Stephanie L , Sweat Victoria , Squires Allison , Wong Laura , Fang Yixin , Doebrich Paula , Gutnick Damara , Tenner Craig , Sherman Scott E , Jay Melanie
Published: February 2021

Introduction

Among US veterans, more than 78% have a body mass index (BMI) in the overweight (≥25 kg/m2) or obese range (≥30 kg/m2). Clinical guidelines recommend multicomponent lifestyle programmes to promote modest, clinically significant body mass (BM) loss. Primary care providers (PCPs) often lack time to counsel and refer patients to intensive programmes (≥6 sessions over 3 months). Using peer coaches to deliver obesity counselling in primary care may increase patient motivation, promote behavioural change and address the specific needs of veterans. We describe the rationale and design of a cluster-randomised controlled trial to test the efficacy of the Peer-Assisted Lifestyle (PAL) intervention compared with enhanced usual care (EUC) to improve BM loss, clinical and behavioural outcomes (aim 1); identify BM-loss predictors (aim 2); and increase PCP counselling (aim 3).

Methods and analysis

We are recruiting 461 veterans aged 18–69 years with obesity or overweight with an obesity-associated condition under the care of a PCP at the Brooklyn campus of the Veterans Affairs NY Harbor Healthcare System. To deliver counselling, PAL uses in-person and telephone-based peer support, a tablet-delivered goal-setting tool and PCP training. Patients in the EUC arm receive non-tailored healthy living handouts. In-person data collection occurs at baseline, month 6 and month 12 for patients in both arms. Repeated measures modelling based on mixed models will compare mean BM loss (primary outcome) between study arms.

Ethics and dissemination

The protocol has been approved by the Institutional Review Board and the Research and Development Committee at the VA NY Harbor Health Systems (#01607). We will disseminate the results via peer-reviewed publications, conference presentations and meetings with stakeholders.

Trial registration number

NCT03163264; Pre-results.
Open-label placebo for insomnia (OPIN): study protocol for a cohort multiple randomised controlled trial
Authors: Colagiuri Ben , Sharpe Louise , Ambarchi Zahava , Glozier Nick , Bartlett Delwyn , Costa Daniel S J , Scott Amelia
Published: February 2021

Introduction

Insomnia is a prevalent sleep disorder that causes substantial personal and societal harm. There is evidence that placebo interventions can reduce insomnia symptoms, but this research has involved deceptively administering the placebo under the guise of a real medication (conventional placebo, CP), which has obvious ethical constraints. Open-label placebo (OLP) treatment, in which a placebo is administered with full disclosure that there are no active ingredients, has been proposed as a method of using the placebo effect ethically, but the efficacy and acceptability of OLP for insomnia is currently unknown.

Methods and analysis

This study uses a cohort multiple randomised controlled trial design to compare OLP, CP and no treatment for insomnia. Two-hundred and sixty-seven participants with self-reported insomnia symptoms (Insomnia Severity Index, ISI ≥10) will be recruited into an observational study and have their sleep monitored over a 2-week period. Participants will then be randomised to one of three groups: invite to OLP, invite to CP described deceptively as a new pharmacological agent, or no invite/observational control. Those in OLP and CP accepting the invite receive identical placebos for a 2-week treatment period while sleep is monitored in all participants. The primary outcome is ISI at the end of the treatment period. Secondary outcomes include treatment uptake and clinically significant response rates, objective and subjective sleep parameters, fatigue, mood, expectancy, treatment satisfaction and side effects. Predictors of uptake and responses to OLP and CP will be explored.

Ethics and dissemination

The trial has been approved by The University of Sydney Human Research Ethics Committee. Written informed consent is obtained from every participant. OLP and CP participants accepting the invite undergo an additional consent process. Results will be disseminated via peer-reviewed conference proceedings and publications.

Trial registration number

ACTRN12620001080910.
Living with COVID-19: a phenomenological study of hospitalised patients involved in family cluster transmission
Authors: Liu Wei , Liu Jia
Published: February 2021

Objectives

To describe experiences of hospitalised patients with COVID-19 following family cluster transmission of the infection and the meaning of these experiences for them.

Design

A descriptive phenomenological design was used to construct themes depicting patients’ experiences of living with COVID-19.

Setting

This study was conducted in a major teaching hospital in Wuhan, China, in March 2020.

Participants

Fourteen patients involved in family cluster transmission of COVID-19 were recruited into the study. The participants consisted of seven males and seven females. Data were collected through semistructured, in-depth, face-to-face interviews. Interviews were transcribed verbatim and analysed using Colaizzi’s approach.

Results

Six themes emerged from data analysis during two distinct phases of patients going through COVID-19: the early outbreak phase and the later hospitalisation phase. Early in the outbreak, patients experienced life imbalances between individual well-being and family responsibilities. While facing widespread prejudice and rejection, patients dealt with the heavy toll that the illness had left on their body and mind. After being hospitalised, patients described feelings of living with uncertainty, sadness, fear of death and concerns about family, while simultaneously hoping for a better life after recovery.

Conclusions

Our findings suggest that living with COVID-19 is an emotionally and physically challenging experience for patient participants in the study. Psychological evaluations need to be routinely carried out with patients in a public health crisis. Interprofessional and interorganisational collaborative efforts should be made to examine the physical and psychological sequelae of COVID-19, as well as investigate outcomes of existing intervention programmes.
Understanding vehicular routing behavior with location-based service data
Authors: Xu Yanyan , Clemente Riccardo Di , González Marta C.
Published: February 2021

Properly extracting patterns of individual mobility with high resolution data sources such as the one extracted from smartphone applications offers important opportunities. Potential opportunities not offered by call detailed records (CDRs), which offer resolutions triangulated from antennas, are route choices, travel modes detection and close encounters. Nowadays, there is not a standard and large scale data set collected over long periods that allows us to characterize these. In this work we thoroughly examine the use of data from smartphone applications, also referred to as location-based services (LBS) data, to extract and understand the vehicular route choice behavior. Taking the Dallas-Fort Worth metroplex as an example, we first extract the vehicular trips with simple rules and reconstruct the origin-destination matrix by coupling the extracted vehicular trips of the active LBS users and the United States census data. We then present a method to derive the commonly used routes by individuals from the LBS traces with varying sample rate intervals. We further inspect the relation between the number of routes and the trip characteristics, including the departure time, trip length and travel time. Specifically, we consider the travel time index and buffer index for the LBS users taking different number of routes. Empirical results demonstrate that during the peak hours, travelers tend to reduce the impact of traffic congestion by taking alternative routes. Overall, the proposed data analysis framework is cost-effective to treat sparse data generated from the use of smartphones to inform routing behavior. The potential in practice is to inform demand management strategies, by targeting individual users while generating large scale estimates of congestion mitigation.
Representations and classification of the compact quantum groups Uq(2) for complex deformation parameters
Authors: Guin Satyajit , Saurabh Bipul
Published: February 2021

In this paper, we obtain a complete list of inequivalent irreducible representations of the compact quantum group [Formula: see text] for nonzero complex deformation parameters [Formula: see text], which are not roots of unity. The matrix coefficients of these representations are described in terms of the little [Formula: see text]-Jacobi polynomials. The Haar state is shown to be faithful and an orthonormal basis of [Formula: see text] is obtained. Thus, we have an explicit description of the Peter–Weyl decomposition of [Formula: see text]. As an application, we discuss the Fourier transform and establish the Plancherel formula. We also describe the decomposition of the tensor product of two irreducible representations into irreducible components. Finally, we classify the compact quantum group [Formula: see text].
Non-extensive value-at-risk estimation during times of crisis
Authors: Hajihasani Ahmad , Namaki Ali , Asadi Nazanin , Tehrani Reza
Published: February 2021

Value-at-risk (VaR) is a crucial subject that researchers and practitioners extensively use to measure and manage uncertainty in financial markets. Although VaR is a standard risk control instrument, there are criticisms about its performance. One of these cases, which has been studied in this research, is the VaR underestimation during times of crisis. In these periods, the non-Gaussian behavior of markets intensifies, and the estimated VaRs by typical models are lower than the real values. A potential approach that can be used to describe the non-Gaussian behavior of return series is the Tsallis entropy framework and nonextensive statistical methods. This paper has used the nonextensive models for analyzing financial markets’ behavior during crisis times. By applying the q-Gaussian probability density function for emerging and mature markets over 20 years, we can see a better VaR estimation than the regular models, especially during crisis times. We have shown that the q-Gaussian models composed of VaR and Expected Shortfall (ES) estimate risk better than the standard models. By comparing the ES, VaR, [Formula: see text]-VaR and [Formula: see text]-ES for emerging and mature markets, we see in confidence levels more than 0.98, the outputs of q models are more real, and the [Formula: see text]-ES model has lower errors than the other ones. Also, it is evident that in the mature markets, the difference of VaR between normal condition and nonextensive approach increases more than one standard deviation during times of crisis. Still, in the emerging markets, we cannot see a specific pattern. The findings of this paper are useful for analyzing the risk of financial crises in different markets.
Quasi-Periodic Motion and Hopf Bifurcation of a Two-Dimensional Aeroelastic Airfoil System in Supersonic Flow
Authors: Huang Wentao , Cao Chengcheng , He Dongping
Published: February 2021

In this article, the complex dynamic behavior of a nonlinear aeroelastic airfoil model with cubic nonlinear pitching stiffness is investigated by applying a theoretical method and numerical simulation method. First, through calculating the Jacobian of the nonlinear system at equilibrium, we obtain necessary and sufficient conditions when this system has two classes of degenerated equilibria. They are described as: (1) one pair of purely imaginary roots and one pair of conjugate complex roots with negative real parts; (2) two pairs of purely imaginary roots under nonresonant conditions. Then, with the aid of center manifold and normal form theories, we not only derive the stability conditions of the initial and nonzero equilibria, but also get the explicit expressions of the critical bifurcation lines resulting in static bifurcation and Hopf bifurcation. Specifically, quasi-periodic motions on 2D and 3D tori are found in the neighborhoods of the initial and nonzero equilibria under certain parameter conditions. Finally, the numerical simulations performed by the fourth-order Runge–Kutta method provide a good agreement with the results of theoretical analysis.
Stability and Bifurcation Analysis in a Predator–Prey Model with Age Structure and Two Delays
Authors: Wang Yujia , Fan Dejun , Wei Junjie
Published: February 2021

In this paper, a predator–prey model with age structure, Beddington–DeAngelis functional response and time delays is considered. Using a geometric method for studying transcendental equation with two delays, we conduct detailed analysis on the distribution of the roots for the characteristic equation of the model. Then, applying the integrated semigroup theory and the Hopf bifurcation theorem for an abstract Cauchy problem within a nondense domain, we proved the existence of Hopf bifurcation for the model. Stability switches can also occur, as the two time delays pass through a continuous curve in the parameter plane. To illustrate the theoretical results, numerical simulations are presented.
Multistability in a 3D Autonomous System with Different Types of Chaotic Attractors
Authors: Yang Ting
Published: February 2021

This paper investigates multistability in a 3D autonomous system with different types of chaotic attractors, which are not in the sense of Shil’nikov criteria. First, under some conditions, the system has infinitely many isolated equilibria. Moreover, all equilibria are nonhyperbolic and give the first Lyapunov coefficient. Furthermore, when all equilibria are weak saddle-foci, the system also has infinitely many chaotic attractors. Besides, the Lyapunov exponents spectrum and bifurcation diagram are given. Second, under another condition, all the equilibria constitute a curve and there exist infinitely many singular degenerated heteroclinic orbits. At the same time, the system can show infinitely many chaotic attractors.
STUDY ON A RAPID MANUFACTURING OF DIAMOND MICROMIXER BY CO2 LASER
Authors: TIAN YUE , CHEN XUEYE
Published: February 2021

In this paper, the influence of the parameters of CO2 laser cutting system on the rhombus microchannel is studied. In the experiment, we changed the laser processing speed, laser processing power, and laser processing number of CO2 laser cutting system, and the depth and width of microchannel are studied by changing these three parameters. It is found that the depth and width of microchannel increase with the increase of laser processing number and laser processing power. For example, when the speed is 6[Formula: see text]mm/s and the number of laser processing is three times, the width of microchannel increases from 0.51[Formula: see text]mm to 0.64[Formula: see text]mm and the depth increases from 0.75[Formula: see text]mm to 1.60[Formula: see text]mm with the increase of power. However, the depth and width of the microchannel decrease with the increase of laser processing speed. For example, when the power is 8[Formula: see text]W and the number of laser processing is three times, the width of the microchannel decreases from 0.51[Formula: see text]mm to 0.39[Formula: see text]mm, and the depth of the microchannel decreases from 0.75[Formula: see text]mm to 0.34[Formula: see text]mm.
SYNTHESIS, CHARACTERIZATION AND ORR ACTIVITY OF METAL-N4-NANOCOMPOSITES
Authors: SHARMA VIVEK , KUMAR ANUJ
Published: February 2021

Inspired by nature, Metal-N4-complexes have been utilized as potential models to catalyze the sluggish oxygen reduction reaction (ORR) at cathode in fuel cells. Herein, we designed and synthesized dibenzo-N4-[14]annulene metal complexes of FeII and CoII metal ions and their nanocomposites with carbon black and characterized by various techniques. Computational and spectroscopic results suggested that the prepared complexes have saddle octahedral geometry. Further, the electrocatalytic activity of prepared nanocomposites towards ORR was investigated by using cyclic and linear sweep voltammetric techniques. The results exhibited that these nanocomposites are significantly ORR active; however, Fe-nanocomposite showed high ORR activity as compared to Co-composite. Theoretical studies indicated that the HOMO of Fe-complex was very near to the antibonding LUMO orbitals of dioxygen as compared to Co-complex, endowing high ORR activity.
Braided Rota–Baxter algebras, quantum quasi-shuffle algebras and braided dendriform algebras
Authors: Li Yunnan , Guo Li
Published: February 2021

Rota–Baxter algebras and the closely related dendriform algebras have important physics applications, especially to renormalization of quantum field theory. Braided structures provide effective ways of quantization such as for quantum groups. Continuing recent study relating the two structures, this paper considers Rota–Baxter algebras and dendriform algebras in the braided contexts. Applying the quantum shuffle and quantum quasi-shuffle products, we construct free objects in the categories of braided Rota–Baxter algebras and braided dendriform algebras, under the commutativity condition. We further generalize the notion of dendriform Hopf algebra to the braided context and show that quantum shuffle algebra gives a braided dendriform Hopf algebra. Enveloping braided commutative Rota–Baxter algebras of braided commutative dendriform algebras are obtained.
Quantum-state estimation problem via optimal design of experiments
Authors: Suzuki Jun
Published: February 2021

In this paper, we study the quantum-state estimation problem in the framework of optimal design of experiments. We first find the optimal designs about arbitrary qubit models for popular optimality criteria such as [Formula: see text]-, [Formula: see text]-, and [Formula: see text]-optimal designs. We also give the one-parameter family of optimality criteria which includes these criteria. We then extend a classical result in the design problem, the Kiefer–Wolfowitz theorem, to a qubit system showing the [Formula: see text]-optimal design which is equivalent to a certain type of the [Formula: see text]-optimal design. We next compare and analyze several optimal designs based on the efficiency. We explicitly demonstrate that an optimal design for a certain criterion can be highly inefficient for other optimality criteria.
Monotonicity results for the fractional p-Laplacian in unbounded domains
Authors: Wu Leyun , Yu Mei , Zhang Binlin
Published: February 2021

In this paper, we develop a direct method of moving planes in unbounded domains for the fractional p-Laplacians, and illustrate how this new method to work for the fractional p-Laplacians. We first proved a monotonicity result for nonlinear equations involving the fractional p-Laplacian in [Formula: see text] without any decay conditions at infinity. Second, we prove De Giorgi conjecture corresponding to the fractional p-Laplacian under some conditions. During these processes, we introduce some new ideas: (i) estimating the singular integrals defining the fractional p-Laplacian along a sequence of approximate maxima; (ii) estimating the lower bound of the solutions by constructing sub-solutions.
PRICING MULTI-ASSET AMERICAN OPTION WITH STOCHASTIC CORRELATION COEFFICIENT UNDER VARIANCE GAMMA ASSET PRICE DYNAMIC
Authors: MEHRDOUST FARSHID , SAMIMI OLDOUZ
Published: February 2021

This paper considers a class of Levy process namely the variance gamma (VG) process to offer a more realistic way to model the dynamics of the logarithm of stock prices. Then, we verify the uniqueness and existence of the solution to the stochastic differential equation of the model. We also examine the valuation of multi-asset American options under VG model when the correlation coefficient is governed by the modified Ornstein–Uhlenbeck process. Various simulation experiments are presented and the achieved results are tested empirically for option prices using S&P 500 data.
Convergence Potentials in SAARC and ASEAN Economies
Authors: GHATAK SUNTERA
Published: February 2021

This study has set to compare the usefulness of the regional integration efforts taken by two important economic blocs, SAARC and ASEAN, within the Asian continent to reduce the regional income inequality. Therefore, the existence of income convergence (or divergence) among the SAARC and ASEAN countries is the aim of this study. To investigate whether (or not) there exists income convergence across the SAARC and ASEAN blocs over the period of 1970-2017, [Formula: see text]-convergence, σ-convergence and club convergence estimation methods have been applied. The results confirm the convergence of income across the ASEAN member countries, which is absent for the SAARC member countries at the intra-regional level. Although we considered all countries of the SAARC and ASEAN blocs together in the panel, an evidence of income convergence over the years has been found. The analysis supports the view of trade liberalization and recommends investing in the human capital to narrow down the regional disparity in future. To achieve a favorable impact of Asian rising growth, regional integration is important, for that a collective policy framework at the regional level is needed for both SAARC and ASEAN.
Putative arthropod trace fossils from the Orcadian Basin at Achanarras Quarry (Middle Devonian of Scotland)
Authors: Flannery-Sutherland Joseph T.
Published: February 2021

Achanarras Quarry, Caithness, Scotland displays a diverse fossil fish fauna that is presumed to have inhabited shallow-lacustrine environments present in the Orcadian Basin during the Early to Middle Devonian. Although Achanarras Quarry itself exposes deep-lacustrine facies, the ecology of their depositional environment remains unknown, in stark contrast to the detailed environmental reconstructions available for the lake margin. I report putative arthropod trace fossils from Achanarras Quarry that are tentatively interpreted as having been formed in a deep-lake environment. Transport of doomed pioneers from the thriving shallow-water ecosystems by turbidite flows is discussed as a possible scenario for their formation. The infrequent and ephemeral intrusions of animals into the deep waters of Lake Orcadie fit the broader narrative of the colonization of deep-lake ecosystems after the Devonian. These interpretations of deep-lacustrine trace fossils from Achanarras, along with their place within the narrative of lake ecosystem evolution, are made cautiously, however, given the paucity of the specimens and the uncertainty surrounding their sedimentary setting.
Conditional Text Generation for Harmonious Human-Machine Interaction
Authors: Guo Bin , Wang Hao , Ding Yasan , Wu Wei , Hao Shaoyang , Sun Yueqi , Yu Zhiwen
Published: February 2021

In recent years, with the development of deep learning, text-generation technology has undergone great changes and provided many kinds of services for human beings, such as restaurant reservation and daily communication. The automatically generated text is becoming more and more fluent so researchers begin to consider more anthropomorphic text-generation technology, that is, the conditional text generation, including emotional text generation, personalized text generation, and so on. Conditional Text Generation (CTG) has thus become a research hotspot. As a promising research field, we find that much attention has been paid to exploring it. Therefore, we aim to give a comprehensive review of the new research trends of CTG. We first summarize several key techniques and illustrate the technical evolution route in the field of neural text generation, based on the concept model of CTG. We further make an investigation of existing CTG fields and propose several general learning models for CTG. Finally, we discuss the open issues and promising research directions of CTG.
Attentive Excitation and Aggregation for Bilingual Referring Image Segmentation
Authors: Zhou Qianli , Hui Tianrui , Wang Rong , Hu Haimiao , Liu Si
Published: February 2021

The goal of referring image segmentation is to identify the object matched with an input natural language expression. Previous methods only support English descriptions, whereas Chinese is also broadly used around the world, which limits the potential application of this task. Therefore, we propose to extend existing datasets with Chinese descriptions and preprocessing tools for training and evaluating bilingual referring segmentation models. In addition, previous methods also lack the ability to collaboratively learn channel-wise and spatial-wise cross-modal attention to well align visual and linguistic modalities. To tackle these limitations, we propose a Linguistic Excitation module to excite image channels guided by language information and a Linguistic Aggregation module to aggregate multimodal information based on image-language relationships. Since different levels of features from the visual backbone encode rich visual information, we also propose a Cross-Level Attentive Fusion module to fuse multilevel features gated by language information. Extensive experiments on four English and Chinese benchmarks show that our bilingual referring image segmentation model outperforms previous methods.
SK channel blockade prevents hypoxia-induced ventricular arrhythmias through inhibition of Ca2+/voltage uncoupling in hypertrophied hearts
Authors: Takahashi Masayuki , Yokoshiki Hisashi , Mitsuyama Hirofumi , Watanabe Masaya , Temma Taro , Kamada Rui , Hagiwara Hikaru , Takahashi Yumi , Anzai Toshihisa
Published: February 2021

We demonstrated that hypoxia-induced ventricular arrhythmias were mainly initiated by Ca2+-loaded triggered activities in hypertrophied hearts. The blockades of small-conductance Ca2+-activated K+ channels, especially “apamin,” showed anti-arrhythmic effects by alleviation of not only action potential duration shortening but also Ca2+ handling abnormalities, most notably the “Ca2+/voltage uncoupling.”