bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Artificial Intelligence Interpretation of Colposcopic Images in Cervical Cancer Screening
Authors: Kim Seongmin , Lee Hwajung , Lee Sanghoon , Song Jae-Yun , Lee Jae-Kwan , Lee Nak-Woo
Published: March 2022

The accuracy of colposcopic diagnosis depends on the skill and proficiency of physicians. This study evaluated the feasibility of interpreting colposcopic images with the assistance of artificial intelligence (AI) for the diagnosis of high-grade cervical intraepithelial lesions. This study included female patients who underwent colposcopy-guided biopsy in 2020 at two institutions in the Republic of Korea. Two experienced colposcopists reviewed all images separately. The Cerviray AI® system (AIDOT, Seoul, Korea) was used to interpret the cervical images. AI demonstrated improved sensitivity with comparable specificity and positive predictive value when compared with the colposcopic impressions of each clinician. The areas under the curve were greater with combined impressions (both AI and that of the two colposcopists) of high-grade lesions, when compared with the individual impressions of each colposcopist. This study highlights the feasibility of the application of an AI system in cervical cancer screening. AI interpretation can be utilized as an assisting tool in combination with human colposcopic evaluation of exocervix.
Virucidal Activity of Different Mouthwashes against the Salivary Load of SARS-CoV-2: A Narrative Review
Authors: Garcia-Sanchez Alvaro , Peña-Cardelles Juan-Francisco , Salgado-Peralvo Angel-Orión , Robles Flor , Ordonez-Fernandez Esther , Ruiz Steve , Végh Dániel
Published: March 2022

The saliva of COVID-19-confirmed patients presents a high viral load of the virus. Aerosols generated during medical and dental procedures can transport the virus and are a possible causative agent of cross-infection. Since the onset of the pandemic, numerous investigations have been attempting to mitigate the risk of transmission by reducing the viral load in saliva using preprocedural mouthwashes. This study aims to review the most up-to-date in vitro and in vivo studies investigating the efficacy of different mouthwashes on reducing the salivary viral load of SARS-CoV-2, giving particular attention to the most recent randomized control trials published.
KRAS Assessment Following ESMO Recommendations for Colorectal Liver Metastases. Is It Always Worth It?
Authors: Morató Olga , Villamonte Maria , Sánchez-Velázquez Patricia , Pueyo-Périz Eva , Grande Luís , Ielpo Benedetto , Rosso Edoardo , Anselmo Alessandro , Burdío Fernando
Published: March 2022

Background: Genetic evaluation is essential in assessing colorectal cancer (CRC) and colorectal liver metastasis (CRLM). The aim of this study was to determine the pragmatic value of KRAS on oncological outcomes after CRLM according to the ESMO recommendations and to query whether it is necessary to request KRAS testing in each situation. Methods: A retrospective cohort of 126 patients who underwent surgery for hepatic resection for CRLM between 2009 and 2020 were reviewed. The patients were divided into three categories: wild-type KRAS, mutated KRAS and impractical KRAS according to their oncological variables. The impractical (not tested) KRAS group included patients with metachronous tumours and negative lymph nodes harvested. Disease-free survival (DFS), overall survival (OS) and hepatic recurrence-free survival (HRFS) were calculated by the Kaplan–Meier method, and a multivariable analysis was conducted using the Cox proportional hazards regression model. Results: Of the 108 patients identified, 35 cases had KRAS wild-type, 50 cases had a KRAS mutation and the remaining 23 were classified as impractical KRAS. Significantly longer medians for OS, HRFS and DFS were found in the impractical KRAS group. In the multivariable analyses, the KRAS mutational gene was the only variable that was maintained through OS, HRFS and DFS. For HRFS (HR: 13.63; 95% confidence interval (CI): 1.35–100.62; p = 0.010 for KRAS), for DFS (HR: 10.06; 95% CI: 2.40–42.17; p = 0.002 for KRAS) and for OS (HR: 4.55%; 95% CI: 1.37–15.10; p = 0.013). Conclusion: Our study considers the possibility of unnecessary KRAS testing in patients with metachronous tumours and negative lymph nodes harvested. Combining the genetic mutational profile (i.e., KRAS in specific cases) with tumour characteristics helps patient selection and achieves the best prognosis after CRLM resection.
South African Banks’ Cross-Border Systemic Risk Exposure: An Application of the GAS Copula Marginal Expected Shortfall
Authors: Manguzvane Mathias Mandla , Muteba Mwamba John Weirstrass
Published: March 2022

Systemic susceptibility highlights the extent to which a banking sector is sensitive to negative shocks. Policymakers and regulators’ objective is to avoid financial crises, and even though they can somewhat control local conditions, internationally transmitted crises are difficult to tackle. This paper analyzes the cross-border systemic risk exposure of South African banks. The marginal expected shortfall is employed with data covering 2002 to 2020. The results show that South African banks are significantly prone to crises emanating beyond the country’s borders. The findings confirm the existence of a significant transfer of risk from other countries to South Africa’s banking sector. Moreover, the amount of foreign capital invested in a bank is found to be a strong predictor of a bank’s international exposure. Knowledge of the linkages that the banking system has with other countries, and how cross-border exposures endanger banks, will form a basis for regulations that ensure a safer financial system.
Extracellular Vesicles Secreted by Glioma Stem Cells Are Involved in Radiation Resistance and Glioma Progression
Authors: Ma Chenkai , Nguyen Hong P. T. , Jones Jordan J. , Stylli Stanley S. , Whitehead Clarissa A. , Paradiso Lucy , Luwor Rodney B. , Areeb Zammam , Hanssen Eric , Cho Ellie , Putz Ulrich , Kaye Andrew H. , Morokoff Andrew P.
Published: March 2022

Glioblastoma is the most aggressive brain tumour with short survival, partly due to resistance to conventional therapy. Glioma stem cells (GSC) are likely to be involved in treatment resistance, by releasing extracellular vesicles (EVs) containing specific molecular cargoes. Here, we studied the EVs secreted by glioma stem cells (GSC-EVs) and their effects on radiation resistance and glioma progression. EVs were isolated from 3 GSCs by serial centrifugation. NanoSight measurement, cryo-electron microscopy and live imaging were used to study the EVs size, morphology and uptake, respectively. The non-GSC glioma cell lines LN229 and U118 were utilised as a recipient cell model. Wound healing assays were performed to detect cell migration. Colony formation, cell viability and invadopodium assays were conducted to detect cell survival of irradiated recipient cells and cell invasion post GSC-EV treatment. NanoString miRNA global profiling was used to select for the GSC-EVs’ specific miRNAs. All three GSC cell lines secreted different amounts of EVs, and all expressed consistent levels of CD9 but different level of Alix, TSG101 and CD81. EVs were taken up by both LN229 and U118 recipient cells. In the presence of GSC-EVs, these recipient cells survived radiation exposure and initiated colony formation. After GSC-EVs exposure, LN229 and U118 cells exhibited an invasive phenotype, as indicated by an increase in cell migration. We also identified 25 highly expressed miRNAs in the GSC-EVs examined, and 8 of these miRNAs can target PTEN. It is likely that GSC-EVs and their specific miRNAs induced the phenotypic changes in the recipient cells due to the activation of the PTEN/Akt pathway. This study demonstrated that GSC-EVs have the potential to induce radiation resistance and modulate the tumour microenvironment to promote glioma progression. Future therapeutic studies should be designed to interfere with these GSC-EVs and their specific miRNAs.
Molecular Cross-Talk between Gravity- and Light-Sensing Mechanisms in Euglena gracilis
Authors: Nasir Adeel , Richter Peter Rolf , Le Bail Aude , Daiker Viktor , Stoltze Julia , Prasad Binod , Strauch Sebastian Michael , Lebert Michael
Published: March 2022

Euglena gracilis is a photosynthetic flagellate. To acquire a suitable position in its surrounding aquatic environment, it exploits light and gravity primarily as environmental cues. Several physiological studies have indicated a fine-tuned relationship between gravity sensing (gravitaxis) and light sensing in E. gracilis. However, the underlying molecular mechanism is largely unknown. The photoreceptor photoactivated adenylyl cyclase (PAC) has been studied for over a decade. Nevertheless, no direct/indirect interaction partner (upstream/downstream) has been reported for PAC. It has been shown that a specific protein, kinase A (PKA), showed to be involved in phototaxis and gravitaxis. The current study reports the localization of the specific PKA and its relationship with PAC.
The Effects of Light and the Circadian System on Rhythmic Brain Function
Authors: von Gall Charlotte
Published: March 2022

Life on earth has evolved under the influence of regularly recurring changes in the environment, such as the 24 h light/dark cycle. Consequently, organisms have developed endogenous clocks, generating 24 h (circadian) rhythms that serve to anticipate these rhythmic changes. In addition to these circadian rhythms, which persist in constant conditions and can be entrained to environmental rhythms, light drives rhythmic behavior and brain function, especially in nocturnal laboratory rodents. In recent decades, research has made great advances in the elucidation of the molecular circadian clockwork and circadian light perception. This review summarizes the role of light and the circadian clock in rhythmic brain function, with a focus on the complex interaction between the different components of the mammalian circadian system. Furthermore, chronodisruption as a consequence of light at night, genetic manipulation, and neurodegenerative diseases is briefly discussed.
Long-Term Changes in Ovarian Follicles of Gilts Exposed Neonatally to Methoxychlor: Effects on Oocyte-Derived Factors, Anti-Müllerian Hormone, Follicle-Stimulating Hormone, and Cognate Receptors
Authors: Witek Patrycja , Grzesiak Małgorzata , Koziorowski Marek , Slomczynska Maria , Knapczyk-Stwora Katarzyna
Published: March 2022

In this paper, we investigated the effects of neonatal exposure to methoxychlor (MXC), a synthetic organochlorine used as an insecticide with estrogenic, antiestrogenic, and antiandrogenic activities on ovarian follicles of adult pigs. Piglets were injected with MXC (20 μg/kg body weight) or corn oil (controls) from postnatal Day 1 to Day 10 (n = 5 per group). Then, mRNA expression, protein abundance and immunolocalization of growth and differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), anti-Müllerian hormone (AMH) and cognate receptors (ACVR1, BMPR1A, BMPR1B, TGFBR1, BMPR2, and AMHR2), as well as FSH receptor (FSHR) were examined in preantral and small antral ovarian follicles of sexually mature gilts. The plasma AMH and FSH levels were also assessed. In preantral follicles, neonatal exposure to MXC increased GDF9, BMPR1B, TGFBR1, and BMPR2 mRNAs, while the levels of AMH and BMP15 mRNAs decreased. In addition, MXC also decreased BMP15 and BMPR1B protein abundance. Regarding small antral follicles, neonatal exposure to MXC upregulated mRNAs for BMPR1B, BMPR2, and AMHR2 and downregulated mRNAs for AMH, BMPR1A, and FSHR. MXC decreased the protein abundance of AMH, and all examined receptors in small antral follicles. GDF9 and BMP15 were immunolocalized in oocytes and granulosa cells of preantral follicles of control and treated ovaries. All analyzed receptors were detected in the oocytes and granulosa cells of preantral follicles, and in the granulosa and theca cells of small antral follicles. The exception, however, was FSHR, which was detected only in the granulosa cells of small antral follicles. In addition, MXC decreased the plasma AMH and FSH concentrations. In conclusion, the present study may indicate long-term effects of neonatal MXC exposure on GDF9, BMP15, AMH, and FSH signaling in ovaries of adult pigs. However, the MXC effects varied at different stages of follicular development. It seems that neonatal MXC exposure may result in accelerated initial recruitment of ovarian follicles and impaired cyclic recruitment of antral follicles.
Molecular Mechanisms of Tumor Immunomodulation in the Microenvironment of Colorectal Cancer
Authors: Plundrich Dorothea , Chikhladze Sophia , Fichtner-Feigl Stefan , Feuerstein Reinhild , Briquez Priscilla S.
Published: March 2022

Colorectal cancer remains one of the most important health challenges in our society. The development of cancer immunotherapies has fostered the need to better understand the anti-tumor immune mechanisms at play in the tumor microenvironment and the strategies by which the tumor escapes them. In this review, we provide an overview of the molecular interactions that regulate tumor inflammation. We particularly discuss immunomodulatory cell-cell interactions, cell-soluble factor interactions, cell-extracellular matrix interactions and cell-microbiome interactions. While doing so, we highlight relevant examples of tumor immunomodulation in colorectal cancer.
Comparative Analysis of Enzymatic Transglycosylation Using E. coli Nucleoside Phosphorylases: A Synthetic Concept for the Preparation of Purine Modified 2′-Deoxyribonucleosides from Ribonucleosides
Authors: Drenichev Mikhail S. , Oslovsky Vladimir E. , Zenchenko Anastasia A. , Danilova Claudia V. , Varga Mikhail A. , Esipov Roman S. , Lykoshin Dmitry D. , Alexeev Cyril S.
Published: March 2022

A comparative analysis of the transglycosylation conditions catalyzed by E. coli nucleoside phosphorylases, leading to the formation of 2′-deoxynucleosides, was performed. We demonstrated that maximal yields of 2′-deoxynucleosides, especially modified, can be achieved under small excess of glycosyl-donor (7-methyl-2′-deoxyguanosine, thymidine) and a 4-fold lack of phosphate. A phosphate concentration less than equimolar one allows using only a slight excess of the carbohydrate residue donor nucleoside to increase the reaction’s output. A three-step methodology was elaborated for the preparative synthesis of purine-modified 2′-deoxyribonucleosides, starting from the corresponding ribonucleosides.
Resilience Indicator of Urban Transport Infrastructure: A Review on Current Approaches
Authors: Yang Zhuyu , Barroca Bruno , Bony-Dandrieux Aurélia , Dolidon Hélène
Published: March 2022

Urban transport infrastructures (TIs) play a central role in an urban society that faces more and more disasters. TIs, part of critical infrastructures (CIs), are highly correlated with urban disaster management in terms of their resilience when cities are facing a crisis or disaster. According to many studies, indicator assessment has been frequently used for the resilience management of CIs in recent decades. Defining and characterizing indicators can be useful for disaster managers as it could help monitor and improve the capacities and performance of TIs. The purpose of this paper, therefore, is (1) to identify and summarize the existing indicators of TIs resilience from the currently available literature, and (2) to discuss the possible future studies of the resilience indicator of TIs. The first results indicated that there are some barriers to identify indicators following the common search method through keywords. Additionally, the indicators found are mainly related to technical information, the disruption stage, and internal TIs. Finally, due to the complexity of indicator assessment, sub-indicators and indicator spatialization are widely used in the resilience assessment of urban TIs studies.
Association between Brachial-Ankle Pulse Wave Velocity as a Marker of Arterial Stiffness and Body Mass Index in a Chinese Population
Authors: Zuo Junli , Tang Biwen , O’Rourke Michael F. , Avolio Alberto P. , Adji Audrey
Published: March 2022

Objectives: Arterial stiffness is widely accepted as an important predictor of cardiovascular disease (CVD) development. While obesity is generally associated with increased CVD risk, there is evidence that overweight patients with existing CVD may have better clinical outcomes than their lean counterparts. Our study sought to observe any potential association between brachial–ankle pulse wave velocity (BAPWV), a marker of arterial stiffness related to CVD risk, and Body Mass Index (BMI), a crude and widely used measure of obesity. Methods: Adult individuals (n = 857) assessed for routine CV risk were included and grouped according to their BMI (<25 kg/m2: normal; 25–30 kg/m2: overweight, ≥30 kg/m2: obese). Their anthropometric parameters, brachial cuff pressures, and BAPWV were measured. Results: Brachial pressure was significantly higher as BMI increased. BAPWV showed a positive linear association with systolic (r = 0.66, p < 0.01), mean (r = 0.60, p < 0.01), diastolic (r = 0.51, p < 0.01), and pulse (r = 0.53, p < 0.01) pressures. However, a linear relationship between BMI and BAPWV was only apparent in males aged <50 years (p = 0.01) and in females aged ≥50 years (p < 0.01). In individuals with similar brachial systolic pressure, BAPWV was higher in normal-weight subjects compared to overweight–obese ones. Conclusions: This conflicting finding is attributed to an overestimation of the degree of arterial stiffness as a measure of CVD risk in individuals with a less ‘healthy’ BMI. This suggests that BMI may not the appropriate obesity indicator to assess CV risk. Our finding emphasizes the importance of establishing a non-linear relationship between CVD risk, age, and BMI, taking into account apparent sex differences, to predict future CV events. While this finding may suggest a lower degree of stiffness in large arteries of overweight–obese subjects compared to their normal-weight counterparts, the potential implications for individuals with higher BMI need be explored further.
Routine and Advanced Laboratory Tests for Hemostasis Disorders in COVID-19 Patients: A Prospective Cohort Study
Authors: Billoir Paul , Leprêtre Perrine , Thill Caroline , Bellien Jeremy , Le Cam Duchez Veronique , Selim Jean , Tamion Fabienne , Clavier Thomas , Besnier Emmanuel
Published: March 2022

Background: Thrombosis is frequent during COVID-19 disease, and thus, identifying predictive factors of hemostasis associated with a poor prognosis is of interest. The objective was to explore coagulation disorders as early predictors of worsening critical conditions in the intensive care unit (ICU) using routine and more advanced explorations. Materials: Blood samples within 24 h of ICU admission for viscoelastic point-of-care testing, (VET), advanced laboratory tests: absolute immature platelet count (A-IPC), von Willebrand-GPIb activity (vWF-GpIb), prothrombin fragments 1 + 2 (F1 + 2), and the thrombin generation assay (TGA) were used. An association with worse outcomes was explored using univariable and multivariable analyses. Worsening was defined as death or the need for organ support. Results: An amount of 85 patients with 33 in critical condition were included. A-IPC were lower in worsening patients (9.6 [6.4–12.5] vs. 12.3 [8.3–20.7], p = 0.02) while fibrinogen (6.9 [6.1–7.7] vs. 6.2 [5.4–6.9], p = 0.03), vWF-GpIb (286 [265–389] vs. 268 [216–326], p = 0.03) and F1 + 2 (226 [151–578] vs. 155 [129–248], p = 0.01) were higher. There was no difference observed for D-dimer, TGA or VET. SAPS-II and A-IPC were independently associated with worsening (OR = 1.11 [1.06–1.17] and OR = 0.47 [0.25–0.76] respectively). The association of a SAPS-II ≥ 33 and an A-IPC ≤ 12.6 G/L predicted the worsening of patients (sensitivity 58%, specificity 89%). Conclusions: Immature platelets are early predictors of worsening in severe COVID-19 patients, suggesting a key role of thrombopoiesis in the adaption of an organism to SARS-CoV-2 infection.
Exploring Parent Support Needs during the Newborn Hearing Diagnosis Pathway
Authors: Elliott Kayla , Vears Danya F. , Sung Valerie , Poulakis Zeffie , Sheehan Jane
Published: March 2022

Universal newborn hearing screening (UNHS) facilitates early detection of permanent congenital hearing loss in newborns. In recognition of specific needs among parents, support services have been established within some UNHS programs, including the Victorian Infant Hearing Screening Program (VIHSP). Despite this, there is limited research about how to best support parents in the context of well-established UNHS programs. This project aims to retrospectively explore parental support needs between the newborn hearing screen and enrolment into early intervention services. We used semi-structured interviews with parents three- to- six-months post confirmation of their newborn’s diagnosis of bilateral moderate-profound sensorineural hearing loss. Data were analysed using inductive content analysis. Thirteen parents of ten children were interviewed. Parents described high satisfaction with the support they received. Some parents felt unprepared for a diagnosis of hearing loss, having been reassured that transient causes such as middle ear fluid caused the hearing screen result. Parents reported mixed responses regarding the value of parent-mentor support along the pathway and some parents described needing additional psychological input to adjust to their child’s diagnosis. These findings provide insights into how a well-established UNHS program, VIHSP, supports parents along the hearing diagnosis pathway and how support can be further enriched.
Diagnostic Accuracy of Coronary Angiography-Based Vessel Fractional Flow Reserve (vFFR) Virtual Stenting
Authors: Tomaniak Mariusz , Neleman Tara , Ziedses des Plantes Anniek , Masdjedi Kaneshka , van Zandvoort Laurens J. C. , Kochman Janusz , den Dekker Wijnand K. , Wilschut Jeroen M. , Diletti Roberto , Kardys Isabella , Zijlstra Felix , Van Mieghem Nicolas M. , Daemen Joost
Published: March 2022

3D coronary angiography-based vessel fractional flow reserve (vFFR) proved to be an accurate diagnostic alternative to invasively measured pressure wire based fractional flow reserve (FFR). The ability to compute post-PCI vFFR using pre-PCI vFFR virtual stent analysis is unknown. We aimed to assess the feasibility and diagnostic accuracy of pre-PCI vFFR virtual stenting analysis (residual vFFR) with post-PCI FFR as a reference. This is an observational, single-center retrospective cohort study including consecutive patients from the FFR-SEARCH registry. We blindly calculated residual vFFR from pre-PCI angiograms and compared them to invasive pressure-wire based post-PCI FFR. Inclusion criteria involved presentation with either stable or unstable angina or non-ST elevation myocardial infarction (NSTEMI), ≥1 significant stenosis in one of the epicardial coronary arteries (percentage diameter stenosis of >70% by QCA or hemodynamically relevant stenosis with FFR ≤0.80) and pre procedural angiograms eligible for vFFR analysis. Exclusion criteria comprised patients with ST elevation myocardial infarction (STEMI), coronary bypass grafts, cardiogenic shock or severe hemodynamic instability. Eighty-one pre-PCI residual vFFR measurements were compared to post-PCI FFR and post-PCI vFFR measurements. Mean residual vFFR was 0.91 ± 0.06, mean post-PCI FFR 0.91 ± 0.06 and mean post-PCI vFFR was 0.92 ± 0.05. Residual vFFR showed a high linear correlation (r = 0.84) and good agreement (mean difference (95% confidence interval): 0.005 (−0.002–0.012)) with post-PCI FFR, as well as with post-PCI-vFFR (r = 0.77, mean difference −0.007 (−0.015–0.0003)). Residual vFFR showed good accuracy in the identification of lesions with post-PCI FFR < 0.90 (sensitivity 94%, specificity 71%, area under the curve (AUC) 0.93 (95% CI: 0.86–0.99), p < 0.001). Virtual stenting using vFFR provided an accurate estimation of post-PCI FFR and post-PCI vFFR. Further studies are needed to prospectively validate a vFFR-guided PCI strategy.
Iterative Multiple Bounding-Box Refinements for Visual Tracking
Authors: Cruciata Giorgio , Lo Presti Liliana , La Cascia Marco
Published: March 2022

Single-object visual tracking aims at locating a target in each video frame by predicting the bounding box of the object. Recent approaches have adopted iterative procedures to gradually refine the bounding box and locate the target in the image. In such approaches, the deep model takes as input the image patch corresponding to the currently estimated target bounding box, and provides as output the probability associated with each of the possible bounding box refinements, generally defined as a discrete set of linear transformations of the bounding box center and size. At each iteration, only one transformation is applied, and supervised training of the model may introduce an inherent ambiguity by giving importance priority to some transformations over the others. This paper proposes a novel formulation of the problem of selecting the bounding box refinement. It introduces the concept of non-conflicting transformations and allows applying multiple refinements to the target bounding box at each iteration without introducing ambiguities during learning of the model parameters. Empirical results demonstrate that the proposed approach improves the iterative single refinement in terms of accuracy and precision of the tracking results.
Multi-Modal Sonar Mapping of Offshore Cable Lines with an Autonomous Surface Vehicle
Authors: Jung Jongdae , Lee Yeongjun , Park Jeonghong , Yeu Tae-Kyeong
Published: March 2022

Monitoring offshore infrastructure is a challenging task owing to the harsh ocean environment. To reduce human involvement in this task, this study proposes an autonomous surface vehicle (ASV)-based structural monitoring system for inspecting power cable lines under the ocean surface. The proposed ASV was equipped with multimodal sonar sensors, including a multibeam echosounder (MBES) and side-scan sonar (SSS) for mapping the seafloor, combined with a precisely estimated vehicle pose from navigation sensors. In particular, a globally consistent map was developed using the orthometric height as a vertical datum estimated based on the geoid height received from the GPS. Accordingly, the MBES and SSS generate a map of the target objects in the form of point clouds and sonar images, respectively. Dedicated outlier removal methods for MBES sensing were proposed to preserve the sparse inlier point cloud, and we applied the projection of the SSS image pixels to reflect the geometry of the seafloor. A field test was conducted in an ocean environment using real offshore cable lines to verify the efficiency of the proposed monitoring system.
Working Performance of the Deep-Sea Valve-Controlled Hydraulic Cylinder System under Pressure-Dependent Viscosity Change and Hydrodynamic Effects
Authors: Wu Jia-Bin , Li Li , Zou Xing-Long , Wang Pin-Jian , Wei Wei
Published: March 2022

The valve-controlled hydraulic cylinder system (VCHCS) is commonly used for actuators such as manipulators in deep-sea equipment, whose working performance is crucial to subsea tasks. Affected by the ambient pressure introduced by the pressure compensator, the viscosity of the hydraulic oil increases significantly. On this basis, the viscosity changes further when flowing in the slender pipeline, making the pipeline pressure loss substantially increase and subsequently affecting the working performance of the deep-sea VCHCS. Aiming at this issue, a detailed nonlinear mathematical model of the deep-sea VCHCS is established, in which the viscosity-pressure characteristics of the hydraulic oil is considered to take the viscosity changes in the pipeline into account. Besides, the hydrodynamic effects are also included in the model. Then the corresponding numerical simulation model of the deep-sea VCHCS is established, and its working performance at different depths is simulated and analyzed. When the depth is 11km, the extension and retraction movements are delayed by 52.50% and 43.12% respectively. The root cause of the delay is then analyzed and discussed. Finally, the parameters that affect the working performance are studied, and suggestions to reduce or eliminate the delay phenomenon are given. The results can provide theoretical support for the performance optimization of the deep-sea VCHCS.
Hydrolysis of Al3+ in Aqueous Solutions: Experiments and Ab Initio Simulations
Authors: Giacobello Fausta , Mollica-Nardo Viviana , Foti Claudia , Ponterio Rosina Celeste , Saija Franz , Trusso Sebastiano , Sponer Jiri , Cassone Giuseppe , Giuffrè Ottavia
Published: March 2022

An experimental and computational study on the hydrolysis of Al3+ in aqueous solutions is here reported. Speciation model and formation constants were determined by potentiometric titrations at T = 298.15 K, 0.1 ≤ I/mol L−1 ≤ 1 in aqueous NaCl, NaNO3, NaCl/NaNO3 solutions. The dependence of formation constants on ionic strength is reported in all the ionic media over the range of 0.1–1.0 mol L−1. Under the studied experimental conditions, the formation of Al3(OH)45+ and Al13(OH)327+ species is observed in all the investigated ionic media and ionic strengths. The formation constants of the species formed by Al3+ with Cl− were determined together with the dependence on the ionic strength. Moreover, with the aim of unveiling the molecular structure of the formed Al complexes, quantum-mechanical calculations and state-of-the-art ab initio molecular dynamics simulations under explicit solvation were executed. These computations show, for the first time, the highly cooperative role played by the surrounding water molecules in neutralising mononuclear systems–such as AlCl2+ and AlClOH+–and the hydrolytic polynuclear system, Al3(OH)45+.
Increase Service Life for Rail Wheel Bearings—A Review of Grease Lubrication for This Application
Authors: Allmaier Hannes
Published: March 2022

Billions of rolling bearings (RB) are in use today in a broad and diverse range of applications. In the mobility sector, RB help to reduce friction losses and increase efficiency. In rail applications, the rail wheel rolling bearing is a critical component, which requires a strict maintenance schedule. In this literature review, grease lubrication in RB is reviewed and potential ways to improve the service life of greases in RB are discussed with special emphasis on the application as rail wheel bearing. Understanding the discussed fundamental lubrication processes is the key to increase the service life of the rail wheel bearings and might provide a basis for future work that aims to make maintenance of these bearings condition-based (condition-based maintenance). This review is primarily intended for R&D professionals from rail (and related) industry and others being interested in a rather brief, but fundamental, overview of this subject.
Numerical Evaluation of the Hygrothermal Performance of a Capillary Active Internal Wall Insulation System under Different Internal Conditions
Authors: Kaczorek Dobrosława
Published: March 2022

In certain situations, internal insulation is the only possible renovation option. However, it is risky where there is high humidity in a building and ventilation is not working sufficiently. The internal insulation retrofit changes the original thermal and moisture balance of a wall, therefore, it is necessary to carefully design it already at the initial stage. This paper analyses four interior insulation systems based on open diffusion capillary active materials: wood fibreboards (flex and rigid), perlite boards, and microporous calcium silicate. The hygrothermal performance under the climatic conditions of Central Europe (Poland) was assessed using the WUFI Plus software, taking into account the dynamic variation of indoor and outdoor conditions. The analysis included three insulation thicknesses with different ventilation rates and varying moisture loads. The results show that the hygrothermal properties of the wall change with the increase of insulation thickness and depend on the individual moisture properties of the material. In addition, both the reduction of moisture load and more intensive air exchange improve the hygrothermal properties at the interface between the insulation and the wall. Of all the solutions analysed, the system with perlite board and the system with wood fibreboard showed the worst hygric properties. Conversely, the highest risk of mould and interstitial condensation was recorded for the flex wood fibreboard solution.
Perspectives of RealSense and ZED Depth Sensors for Robotic Vision Applications
Authors: Tadic Vladimir , Toth Attila , Vizvari Zoltan , Klincsik Mihaly , Sari Zoltan , Sarcevic Peter , Sarosi Jozsef , Biro Istvan
Published: March 2022

This review paper presents an overview of depth cameras. Our goal is to describe the features and capabilities of the introduced depth sensors in order to determine their possibilities in robotic applications, focusing on objects that might appear in applications with high accuracy requirements. A series of experiments was conducted, and various depth measuring conditions were examined in order to compare the measurement results of all the depth cameras. Based on the results, all the examined depth sensors were appropriate for applications where obstacle avoidance and robot spatial orientation were required in coexistence with image vision algorithms. In robotic vision applications where high accuracy and precision were obligatory, the ZED depth sensors achieved better measurement results.
Nonlinear Valuation with XVAs: Two Converging Approaches
Authors: Brigo Damiano , Buescu Cristin , Francischello Marco , Pallavicini Andrea , Rutkowski Marek
Published: March 2022

When pricing OTC contracts in the presence of additional risk factors and costs, such as credit risk and funding and collateral costs, the starting “clean price” is modified additively by valuation adjustments (XVAs) that account for each factor or cost in isolation, while seemingly ignoring the combined effects. Instead, risk factors and costs can be jointly accounted for ab initio in the pricing mechanism at the level of cash flows, and this “adjusted cash flow" approach leads to a nonlinear valuation formula. While for practitioners this made more sense because it showed which discount factor is used for which cash flow (recall the multi-curve environment post-crisis), for academics, the focus was on checking that the resulting nonlinear valuation formula is consistent with the theoretical arbitrage-free “replication approach” that we also analyse in the paper. We formulate specific reasonable assumptions, which ensure that the valuation formulae obtained by the two approaches coincide, thus reinforcing both academics’ and practitioners’ confidence in adopting such nonlinear valuation formulae in a multi-curve setup.
Adaptation Process of the Mathematic Self-Efficacy Survey (MSES) Scale to Mexican-Spanish Language
Authors: Morán-Soto Gustavo , Valdivia Vázquez Juan Antonio , González Peña Omar Israel
Published: March 2022

Trained professionals in science, technology, engineering, and mathematics (STEM) are needed for a robust, science-based economy that incorporates various technologies’ design, construction, and commercialization to address societal problems. However, keeping students interested in STEM subjects and achieving optimal performance is a challenging task. Math self-efficacy has shown to be one of the most important factors affecting students’ interest in STEM majors and assessing this factor has been a great challenge for education researchers around the world due to the lack of calibrated and culturally adapted instruments. Observing this need, this seminal study conducted psychometric validation tests and cultural adaptations to the Mathematic Self-Efficacy Survey (MSES) aiming to measure this instrument in Spanish-speaking students in different STEM areas in Mexico. Data collected from 877 students were tested for validity using sequential exploratory factor analyses, and contextual modifications were performed and analyzed aiming to achieve cultural equivalency. Suggestions for continuing the adaptation and validation process of the MSES to Spanish language and STEM students’ context are presented with the results of the exploratory factor analyses.
Factors Influencing Teachers’ Use of ICT in Class: Evidence from a Multilevel Logistic Model
Authors: Gómez-Fernández Nerea , Mediavilla Mauro
Published: March 2022

Information and Communication Technologies (ICTs) have become a key factor in the educational context, especially in the aftermath of the COVID-19 pandemic, and, correctly implemented, can help to improve academic performance. The aim of this research was to analyse the factors that influence teachers’ decisions to use ICT more- or less frequently to carry out tasks and exercises in their classes. To this end, we estimated a multilevel logistic model with census data from the individualized evaluation of students of the Community of Madrid (Spain) carried out at the end of the 2018–2019 academic year in primary and secondary education. Additionally, we applied multiple imputation techniques to deal with missing values. Based on our results, we found that motivated teachers who have received ICT training, teach calm and respectful classes, and work at schools where students have access to digital devices and frequently use ICT at home, have a high predisposition to use ICT in their classes. Considering our results, our recommendations are aimed at improving teacher training in ICT, encouraging a frequent but responsible use of ICT at home, and increasing the provision of technological resources in schools.
SPGD: Search Party Gradient Descent Algorithm, a Simple Gradient-Based Parallel Algorithm for Bound-Constrained Optimization
Authors: Syed Shahul Hameed A. , Rajagopalan Narendran
Published: March 2022

Nature-inspired metaheuristic algorithms remain a strong trend in optimization. Human-inspired optimization algorithms should be more intuitive and relatable. This paper proposes a novel optimization algorithm inspired by a human search party. We hypothesize the behavioral model of a search party searching for a treasure. Motivated by the search party’s behavior, we abstract the “Divide, Conquer, Assemble” (DCA) approach. The DCA approach allows us to parallelize the traditional gradient descent algorithm in a strikingly simple manner. Essentially, multiple gradient descent instances with different learning rates are run parallelly, periodically sharing information. We call it the search party gradient descent (SPGD) algorithm. Experiments performed on a diverse set of classical benchmark functions show that our algorithm is good at optimizing. We believe our algorithm’s apparent lack of complexity will equip researchers to solve problems efficiently. We compare the proposed algorithm with SciPy’s optimize library and it is found to be competent with it.
Classification of Alzheimer’s Disease and Mild-Cognitive Impairment Base on High-Order Dynamic Functional Connectivity at Different Frequency Band
Authors: Khatri Uttam , Kwon Goo-Rak
Published: March 2022

Functional brain connectivity networks obtained from resting-state functional magnetic resonance imaging (rs-fMRI) have been extensively utilized for the diagnosis of Alzheimer’s disease (AD). However, the traditional correlation analysis technique only explores the pairwise relation, which may not be suitable for revealing sufficient and proper functional connectivity links among brain regions. Additionally, previous literature typically focuses on only lower-order dynamics, without considering higher-order dynamic networks properties, and they particularly focus on single frequency range time series of rs-fMRI. To solve these problems, in this article, a new diagnosis scheme is proposed by constructing a high-order dynamic functional network at different frequency level time series (full-band (0.01–0.08 Hz); slow-4 (0.027–0.08 Hz); and slow-5 (0.01–0.027 Hz)) data obtained from rs-fMRI to build the functional brain network for all brain regions. Especially, to tune the precise analysis of the regularized parameters in the Support Vector Machine (SVM), a nested leave-one-out cross-validation (LOOCV) technique is adopted. Finally, the SVM classifier is trained to classify AD from HC based on these higher-order dynamic functional brain networks at different frequency ranges. The experiment results illustrate that for all bands with a LOOCV classification accuracy of 94.10% with a 90.95% of sensitivity, and a 96.75% of specificity outperforms the individual networks. Utilization of the given technique for the identification of AD from HC compete for the most state-of-the-art technology in terms of the diagnosis accuracy. Additionally, results obtained for the all-band shows performance further suggest that our proposed scheme has a high-rate accuracy. These results have validated the effectiveness of the proposed methods for clinical value to the identification of AD.
Usage of Selected Swarm Intelligence Algorithms for Piecewise Linearization
Authors: Škorupová Nicole , Raunigr Petr , Bujok Petr
Published: March 2022

The paper introduces a new approach to enhance optimization algorithms when solving the piecewise linearization problem of a given function. Eight swarm intelligence algorithms were selected to be experimentally compared. The problem is represented by the calculation of the distance between the original function and the estimation from the piecewise linear function. Here, the piecewise linearization of 2D functions is studied. Each of the employed swarm intelligence algorithms is enhanced by a newly proposed automatic detection of the number of piecewise linear parts that determine the discretization points to calculate the distance between the original and piecewise linear function. The original algorithms and their enhanced variants are compared on several examples of piecewise linearization problems. The results show that the enhanced approach performs sufficiently better when it creates a very promising approximation of functions. Moreover, the degree of precision is slightly decreased by the focus on the speed of the optimization process.
Unsupervised and Supervised Methods to Estimate Temporal-Aware Contradictions in Online Course Reviews
Authors: Badache Ismail , Chifu Adrian-Gabriel , Fournier Sébastien
Published: March 2022

The analysis of user-generated content on the Internet has become increasingly popular for a wide variety of applications. One particular type of content is represented by the user reviews for programs, multimedia, products, and so on. Investigating the opinion contained by reviews may help in following the evolution of the reviewed items and thus in improving their quality. Detecting contradictory opinions in reviews is crucial when evaluating the quality of the respective resource. This article aims to estimate the contradiction intensity (strength) in the context of online courses (MOOC). This estimation was based on review ratings and on sentiment polarity in the comments, with respect to specific aspects, such as “lecturer”, “presentation”, etc. Between course sessions, users stop reviewing, and also, the course contents may evolve. Thus, the reviews are time dependent, and this is why they should be considered grouped by the course sessions. Having this in mind, the contribution of this paper is threefold: (a) defining the notion of subjective contradiction around specific aspects and then estimating its intensity based on sentiment polarity, review ratings, and temporality; (b) developing a dataset to evaluate the contradiction intensity measure, which was annotated based on a user study; (c) comparing our unsupervised method with supervised methods with automatic feature selection, over the dataset. The dataset collected from coursera.org is in English. It includes 2244 courses and 73,873 user-generated reviews of those courses.The results proved that the standard deviation of the ratings, the standard deviation of the polarities, and the number of reviews are suitable features for predicting the contradiction intensity classes. Among the supervised methods, the J48 decision trees algorithm yielded the best performance, compared to the naive Bayes model and the SVM model.
Stability Analysis and Synthesis for 2-D Switched Systems with Random Disturbance
Authors: Meng Fei , Shen Xuyu , Li Xiaofeng
Published: March 2022

In this paper, the stability analysis and controller design of two-dimensional (2-D) switched system with random disturbances are studied. First, based on the Fornasini–Marchesini local state space model, a random discrete 2-D switched system model is proposed. Secondly, based on the method of switching quadratic Lyapunov function, Schur complement and linear matrix inequality the criterion of the sufficiency of the asymptotically stable under any switching signal is established. The extended average residence time method is used to obtain a sufficient criterion of the mean square exponential stability of the random discrete 2-D switched system under restricted switching conditions. According to the stability analysis results, the conditions for the existence of the state feedback controller are given and the corresponding state feedback controller is designed. Finally, two examples are given to illustrate the effectiveness of the proposed method.
Existence and Asymptotic Behavior of Ground State Solutions to Kirchhoff-Type Equations of General Convolution Nonlinearity with a Steep Potential Well
Authors: Zhou Li , Zhu Chuanxi
Published: March 2022

In this paper, we consider a new kind of Kirchhoff-type equation which is stated in the introduction. Under certain assumptions on potentials, we prove by variational methods that the equation has at least a ground state solution and investigate the asymptotic behavior of solutions.
The Interplay between Tumour Microenvironment Components in Malignant Melanoma
Authors: Amalinei Cornelia , Grigoraș Adriana , Lozneanu Ludmila , Căruntu Irina-Draga , Giușcă Simona-Eliza , Balan Raluca Anca
Published: March 2022

Malignant melanoma has shown an increasing incidence during the last two decades, exhibiting a large spectrum of locations and clinicopathological characteristics. Although current histopathological, biochemical, immunohistochemical, and molecular methods provide a deep insight into its biological behaviour and outcome, melanoma is still an unpredictable disease, with poor outcome. This review of the literature is aimed at updating the knowledge regarding melanoma’s clinicopathological and molecular hallmarks, including its heterogeneity and plasticity, involving cancer stem cells population. A special focus is given on the interplay between different cellular components and their secretion products in melanoma, considering its contribution to tumour progression, invasion, metastasis, recurrences, and resistance to classical therapy. Furthermore, the influences of the specific tumour microenvironment or “inflammasome”, its association with adipose tissue products, including the release of “extracellular vesicles”, and distinct microbiota are currently studied, considering their influences on diagnosis and prognosis. An insight into melanoma’s particular features may reveal new molecular pathways which may be exploited in order to develop innovative therapeutic approaches or tailored therapy.