bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial Steps towards a Multilevel Functional Principal Components Analysis Model of Dynamical Shape Changes
Authors: Farnell Damian J. J. , Claes Peter
Published: April 2023

In this article, multilevel principal components analysis (mPCA) is used to treat dynamical changes in shape. Results of standard (single-level) PCA are also presented here as a comparison. Monte Carlo (MC) simulation is used to create univariate data (i.e., a single “outcome” variable) that contain two distinct classes of trajectory with time. MC simulation is also used to create multivariate data of sixteen 2D points that (broadly) represent an eye; these data also have two distinct classes of trajectory (an eye blinking and an eye widening in surprise). This is followed by an application of mPCA and single-level PCA to “real” data consisting of twelve 3D landmarks outlining the mouth that are tracked over all phases of a smile. By consideration of eigenvalues, results for the MC datasets find correctly that variation due to differences in groups between the two classes of trajectories are larger than variation within each group. In both cases, differences in standardized component scores between the two groups are observed as expected. Modes of variation are shown to model the univariate MC data correctly, and good model fits are found for both the “blinking” and “surprised” trajectories for the MC “eye” data. Results for the “smile” data show that the smile trajectory is modelled correctly; that is, the corners of the mouth are drawn backwards and wider during a smile. Furthermore, the first mode of variation at level 1 of the mPCA model shows only subtle and minor changes in mouth shape due to sex; whereas the first mode of variation at level 2 of the mPCA model governs whether the mouth is upturned or downturned. These results are all an excellent test of mPCA, showing that mPCA presents a viable method of modeling dynamical changes in shape.
A Collaborative Virtual Walkthrough of Matera’s Sassi Using Photogrammetric Reconstruction and Hand Gesture Navigation
Authors: Notarangelo Nicla Maria , Manfredi Gilda , Gilio Gabriele
Published: April 2023

The COVID-19 pandemic has underscored the need for real-time, collaborative virtual tools to support remote activities across various domains, including education and cultural heritage. Virtual walkthroughs provide a potent means of exploring, learning about, and interacting with historical sites worldwide. Nonetheless, creating realistic and user-friendly applications poses a significant challenge. This study investigates the potential of collaborative virtual walkthroughs as an educational tool for cultural heritage sites, with a focus on the Sassi of Matera, a UNESCO World Heritage Site in Italy. The virtual walkthrough application, developed using RealityCapture and Unreal Engine, leveraged photogrammetric reconstruction and deep learning-based hand gesture recognition to offer an immersive and accessible experience, allowing users to interact with the virtual environment using intuitive gestures. A test with 36 participants resulted in positive feedback regarding the application’s effectiveness, intuitiveness, and user-friendliness. The findings suggest that virtual walkthroughs can provide precise representations of complex historical locations, promoting tangible and intangible aspects of heritage. Future work should focus on expanding the reconstructed site, enhancing the performance, and assessing the impact on learning outcomes. Overall, this study highlights the potential of virtual walkthrough applications as a valuable resource for architecture, cultural heritage, and environmental education.
Construction and Validation of the HeiQ: An Operation-Oriented Figural Matrices Test
Authors: Pallentin Vanessa S. , Danner Daniel , Rummel Jan
Published: April 2023

Figural matrices tests are among the most popular and well-investigated tests used to assess inductive reasoning abilities. Solving these tests requires the selection of a target that completes a figural matrix among distractors. Despite their generally good psychometric properties, previous matrices tests have limitations associated with distractor construction that prevent them from realizing their full potential. Most tests allow participants to identify the correct response by eliminating distractors based on superficial features. The goal of this study was to develop a novel figural matrices test which is less prone to the use of response elimination strategies, and to test its psychometric properties. The new test consists of 48 items and was validated with N = 767 participants. Measurement models implied that the test is Rasch scalable, inferring a uniform underlying ability. The test showed good to very good reliability (retest-correlation: r = 0.88; Cronbach’s alpha: α = 0.93; split-half reliability: r = 0.88) and good construct validity (r = 0.81 with the Raven Progressive Matrices Test, r = 0.73 with global intelligence scores of the Intelligence Structure Test 2000R, and r = 0.58 with the global score of the Berlin Intelligence Structure Test). It even superseded the Raven Progressive Matrices Tests in criterion-related validity (correlation with final year high school grades (r = −0.49 p < .001)). We conclude that this novel test has excellent psychometric properties and can be a valuable tool for researchers interested in reasoning assessment.
Analysis of the Mooring Effects of Future Ultra-Large Container Vessels (ULCV) on Port Infrastructures
Authors: Sáenz Sara Sanz , Diaz-Hernandez Gabriel , Schweter Lutz , Nordbeck Pieter
Published: April 2023

The size of container vessels is continuously growing, always exceeding expectations. Port authorities and terminals need to constantly adapt and face challenges related to maritime infrastructure, equipment, and operations, as these are the principal areas affected by the future Ultra Large Container Vessels (ULCVs). Maneuvring areas are at their limits, and mooring equipment is at an increased risk of being overloaded. This study aims to analyze the limitations that present mooring systems may face when ULCVs are subjected to wind and passing-ship forces exerted by a future ULCV and wind forces through Dynamic Mooring Analysis (DMA). A hypothetical and massive future ULCV with a capacity of 40,000 TEU is compared to the Emma Maersk, which is a present vessel that regularly calls at container terminals. The Emma Maersk, with its current mooring arrangement, experiences higher motion than future ULCVs, which experience higher forces but are also moored with more and stronger lines. This translates into considerably higher loads in the mooring system, potentially compromising safe mooring conditions at the terminal. Mitigating measures are proposed in the study to face these limitations. In addition, the study explores the potential of new and innovative mooring technologies, such as high-strength synthetic ropes and smart mooring systems, to address the challenges posed by ULCVs. A container terminal at the Port of Rotterdam, Europe’s largest sea port, has been analyzed as a case study. The terminal is located next to a busy fairway that leads to other container terminals, justifying the need to analyze both wind and passing-ship effects on moored ships.
Computing Vegetation Indices from the Satellite Images Using GRASS GIS Scripts for Monitoring Mangrove Forests in the Coastal Landscapes of Niger Delta, Nigeria
Authors: Lemenkova Polina , Debeir Olivier
Published: April 2023

This paper addresses the issue of the satellite image processing using GRASS GIS in the mangrove forests of the Niger River Delta, southern Nigeria. The estuary of the Niger River Delta in the Gulf of Guinea is an essential hotspot of biodiversity on the western coast of Africa. At the same time, climate issues and anthropogenic factors affect vulnerable coastal ecosystems and result in the rapid decline of mangrove habitats. This motivates monitoring of the vegetation patterns using advanced cartographic methods and data analysis. As a response to this need, this study aimed to calculate and map several vegetation indices (VI) using scripts as advanced programming methods integrated in geospatial studies. The data include four Landsat 8-9 OLI/TIRS images covering the western segment of the Niger River Delta in the Bight of Benin for 2013, 2015, 2021, and 2022. The techniques included the ’i.vi’, ’i.landsat.toar’ and other modules of the GRASS GIS. Based on the GRASS GIS ’i.vi’ module, ten VI were computed and mapped for the western segment of the Niger River Delta estuary: Atmospherically Resistant Vegetation Index (ARVI), Green Atmospherically Resistant Vegetation Index (GARI), Green Vegetation Index (GVI), Difference Vegetation Index (DVI), Perpendicular Vegetation Index (PVI), Global Environmental Monitoring Index (GEMI), Normalized Difference Water Index (NDWI), Second Modified Soil Adjusted Vegetation Index (MSAVI2), Infrared Percentage Vegetation Index (IPVI), and Enhanced Vegetation Index (EVI). The results showed variations in the vegetation patterns in mangrove habitats situated in the Niger River Delta over the last decade as well as the increase in urban areas (Onitsha, Sapele, Warri and Benin City) and settlements in the Delta State due to urbanization. The advanced techniques of the GRASS GIS of satellite image processing and analysis enabled us to identify and visualize changes in vegetation patterns. The technical excellence of the GRASS GIS in image processing and analysis was demonstrated in the scripts used in this study.
Multi-Target Tracking in Multi-Static Networks with Autonomous Underwater Vehicles Using a Robust Multi-Sensor Labeled Multi-Bernoulli Filter
Authors: Zhang Yuexing , Li Yiping , Li Shuo , Zeng Junbao , Wang Yiqun , Yan Shuxue
Published: April 2023

This paper proposes a centralized MTT method based on a state-of-the-art multi-sensor labeled multi-Bernoulli (LMB) filter in underwater multi-static networks with autonomous underwater vehicles (AUVs). The LMB filter can accurately extract the number of targets and trajectories from measurements affected by noise, missed detections, false alarms and port–starboard ambiguity. However, its complexity increases as the number of sensors increases. In addition, due to the time-varying underwater environment, AUV detection probabilities are time-varying, and their mismatches often lead to poor MTT performance. Consequently, we detail a robust multi-sensor LMB filter that estimates detection probabilities and multi-target states simultaneously in real time. Moreover, we derive an effective approximate form of the multi-sensor LMB filter using Kullback–Leibler divergence and develop an efficient belief propagation (BP) implementation of the multi-sensor LMB filter. Our method scales linearly with the number of AUVs, providing good scalability and low computational complexity. The proposed method demonstrates superior performance in underwater multi-AUV network MTT simulations.
Adaptive Beamforming with Hydrophone Arrays Based on Oblique Projection in the Presence of the Steering Vector Mismatch
Authors: Dai Yan , Sun Chao
Published: April 2023

In sonar systems, the performance of adaptive beamformers severely degrades when mismatches occur between the actual and presumed steering vectors of the desired signal, mainly due to hydrophone position errors, amplitude-phase errors, and the scattered effect of arrays. Similarly, an inadequate number of “training” samples can lead to performance degradations similar to those caused by mismatches. In this paper, an adaptive beamforming algorithm based on oblique projection (OP-ABF) mismatch compensation is proposed to remove the degradation caused by the arbitrary-type steering vector mismatch of the desired signal. The proposed algorithm is motivated by the fact that the weight vector of adaptive beamforming can be represented as a linear combination of the optimal one and the oblique projection (OP) vector, which is generated by the steering vector mismatch and does not exist without this. Our algorithm was developed by constructing the oblique projection mismatch compensation vector (OPMCV) to provide the minimum variance distortionless response (MVDR) beamformer. Then, the algorithm could be implemented by the solution of the OP matrix with the formulation of the covariance matrix loading (CML). The simulation results of a uniform linear array (ULA) and a half-cylindrical conformal array (HCCA) show that the OP-ABF can optimize the original weight vector as much as possible without sacrificing the output signal-to-interference-plus-noise ratio (SINR) under different conditions. Experimental results for the HCCA also confirm the effectiveness of this algorithm.
Effects of Lateral Flows on the Supercavitation and Hydrodynamic Characteristics of Underwater Series and Parallel High-Speed Projectiles
Authors: Zhang Lite , Zhang Chengwei , Jia Huixia , Dong Ruoling
Published: April 2023

In this paper, the supercavitation of the parallel and tandem projectiles moving underwater with high-speed under the condition with/without lateral flows is numerically simulated by the volume of fraction (VOF) model. The motion of the projectiles was handled by the overlapping grid and six degrees of freedom (DOF) techniques. The supercavitation evolution and the hydrodynamic characteristics of the projectiles were analyzed for the parallel and tandem projectiles under different conditions. The results show that the cavity shape is symmetrical under the condition without lateral flows, but is no longer symmetrical under the conditions with lateral flows. The asymmetry of the cavity contour increases with the velocity of the lateral flow. For the parallel projectiles, the change trends of the axial velocity of projectile 1 and projectile 2 are nearly the same. The offset velocity of projectile 1 and projectile 2 increases with the increase in the velocity of the lateral flow. The deflection angle of projectile 1 decreases with the increase in the lateral flow velocity but that of projectile 2 increases with the increase in the lateral flow velocity. At t = 3.0 ms, the deflection angle of projectile 2 is up to 20° under the condition of the lateral flow velocity of 11.25%, while the deflection angle of projectile 1 and 2 under other conditions is in the range of 5°. For the tandem projectiles, the axial velocity of projectile 1 gradually decreases. The change trend of the axial velocity of projectile 2 at first is the same as that of projectile 1, and then the change is dependent on the velocity of the lateral flow. Under the condition of the lateral flow velocity with 11.25%Vp, projectile 2 cannot enter the cavity of the front projectile. The change trend of the axial velocity of projectile 2 is similar as but somewhat slower than that of projectile 1. For the parallel projectiles, the ballistic stability of the projectile on the oncoming side is better than that of the projectile on the backflow side. Whether parallel or tandem projectiles, the ballistic stability of projectile 2 becomes worse with the increase in the lateral flow velocity.
Cyclosporine Affects the Main Virulence Factors of Cryptococcus neoformans In Vitro
Authors: de Andrade Iara Bastos , Corrêa-Junior Dario , Alves Vinicius , Figueiredo-Carvalho Maria Helena Galdino , Santos Marcos Vinicius , Almeida Marcos Abreu , Valdez Alessandro Fernandes , Nimrichter Leonardo , Almeida-Paes Rodrigo , Frases Susana
Published: April 2023

This study aimed to investigate the effects of cyclosporine on the morphology, cell wall structure, and secretion characteristics of Cryptococcus neoformans. The minimum inhibitory concentration (MIC) of cyclosporine was found to be 2 µM (2.4 µg/mL) for the H99 strain. Yeast cells treated with cyclosporine at half the MIC showed altered morphology, including irregular shapes and elongated projections, without an effect on cell metabolism. Cyclosporine treatment resulted in an 18-fold increase in chitin and an 8-fold increase in lipid bodies, demonstrating changes in the fungal cell wall structure. Cyclosporine also reduced cell body and polysaccharide capsule diameters, with a significant reduction in urease secretion in C. neoformans cultures. Additionally, the study showed that cyclosporine increased the viscosity of secreted polysaccharides and reduced the electronegativity and conductance of cells. The findings suggest that cyclosporine has significant effects on C. neoformans morphology, cell wall structure, and secretion, which could have implications for the development of new antifungal agents.
Metabolic Engineering of Pichia pastoris for the Production of Triacetic Acid Lactone
Authors: Feng Linjuan , Xu Junhao , Ye Cuifang , Gao Jucan , Huang Lei , Xu Zhinan , Lian Jiazhang
Published: April 2023

Triacetic acid lactone (TAL) is a promising renewable platform polyketide with broad biotechnological applications. In this study, we constructed an engineered Pichia pastoris strain for the production of TAL. We first introduced a heterologous TAL biosynthetic pathway by integrating the 2-pyrone synthase encoding gene from Gerbera hybrida (Gh2PS). We then removed the rate-limiting step of TAL synthesis by introducing the posttranslational regulation-free acetyl-CoA carboxylase mutant encoding gene from S. cerevisiae (ScACC1*) and increasing the copy number of Gh2PS. Finally, to enhance intracellular acetyl-CoA supply, we focused on the introduction of the phosphoketolase/phosphotransacetylase pathway (PK pathway). To direct more carbon flux towards the PK pathway for acetyl-CoA generation, we combined it with a heterologous xylose utilization pathway or endogenous methanol utilization pathway. The combination of the PK pathway with the xylose utilization pathway resulted in the production of 825.6 mg/L TAL in minimal medium with xylose as the sole carbon source, with a TAL yield of 0.041 g/g xylose. This is the first report on TAL biosynthesis in P. pastoris and its direct synthesis from methanol. The present study suggests potential applications in improving the intracellular pool of acetyl-CoA and provides a basis for the construction of efficient cell factories for the production of acetyl-CoA derived compounds.
Voiding Dysfunction Due to Urethral Sphincter Dysfunction Might Be an Early Neurological Presentation of Central Nervous System Disorders in Aged Patients
Authors: Ho Guan-Ru , Wei Chiao-Wen , Kuo Hann-Chorng
Published: April 2023

Purpose: To investigate the incidence of central nervous system (CNS) diseases in adult patients with voiding dysfunction and videourodynamics (VUDS) proven urethral sphincter dysfunction. Methods: This retrospective analysis reviewed the medical charts of patients aged > 60 years who underwent VUDS for non-prostatic voiding dysfunction from 2006 to 2021. A chart review was performed to search for the occurrence and treatment of CNS diseases after the VUDS examination up to 2022. The diagnosis of CNS disease, such as cerebrovascular accidents (CVA), Parkinson’s disease (PD), and dementia, by neurologists was also retrieved from the charts. Based on the VUDS findings, patients were divided into the following subgroups: dysfunctional voiding (DV), poor relaxation of the external sphincter (PRES), and hypersensitive bladder (HSB) and coordinated sphincter subgroups. The incidence of CVA, PD, and dementia in each subgroup was recorded and compared among them using one-way analysis of variance (ANOVA). Results: A total of 306 patients were included. VUDS examinations revealed DV in 87 patients, PRES in 108, and HSB in 111. Among them, 36 (11.8%) patients had CNS disease, including CVA in 23 (7.5%), PD in 4 (1.3%), and dementia in 9 (2.9%). Among the three subgroups, the DV group had the highest incidence rate of CNS disease (n = 16, 18.4%), followed by PRES (n = 12, 11.1%) and HSB (n = 8, 7.2%). However, no significant difference was noted in the incidence of CNS disease across the three subgroups. Nevertheless, the incidence of CNS disease was higher in patients with DV and PRES than that in the general population. Conclusions: The incidence of CNS diseases was high in patients aged > 60 years with voiding dysfunction due to urethral sphincter dysfunction. Patients with VUDS-confirmed DV had the highest incidence of CNS disease among the three subgroups.
MRI Characteristics and Alterations in Patellar Height in Patients with Patellar Tendinopathy—A Retrospective Study
Authors: Loose Kim , Pennekamp Sophie , Hitzl Wolfgang , Willauschus Maximilian , Rüther Johannes , Silawal Sandeep , Schuster Philipp , Bail Hermann Josef , Millrose Michael , Geßlein Markus
Published: April 2023

(1) Background: Patellar tendinopathy (PT) is an overuse condition of the knee extensor mechanism characterized by ventral knee pain at the lower pole of the patella and limited functionality. (2) Methods: In this retrospective study, a group of patients with PT (n = 41) was compared with a control group (n = 50) in terms of patient-related data and magnetic resonance imaging (MRI) characteristics. (3) Results: Patellar height was higher in the PT patient group and there was a significant difference in Caton–Deschamps index (CD) compared to the control group (p = 0.021). Patients with PT showed a lower patella–patellar tendon angle (PPTA) (p = 0.011). The patellar tendon thickness (PTT) in the proximal (PTTprox), middle (PTTmid) and distal (PTTdistal) part of the tendon was significantly thickened (p < 0.001). Increased signal intensity in MRI was detected in symptomatic tendons over 6 months compared to a duration of less than 6 months (p = 0.025). A significant relationship between the PTTprox and an increased signal intensity was observed (p < 0.001). (4) Conclusions: Patients with PT showed a significant difference in the patellar height and PPTA. With persistence of symptoms over 6 months, MRI seems suitable to detect the morphologic tendon changes and further identify patients suitable for surgical procedures.
Risk Measure between Exchange Rate and Oil Price during Crises: Evidence from Oil-Importing and Oil-Exporting Countries
Authors: Zorgati Mouna Ben Saad
Published: April 2023

This study investigates the risk spillover effect between the exchange rate of importing and exporting oil countries and the oil price. The analysis is supported by the utilization of a set of double-long memories. Thereafter, a multivariate GARCH type model is adopted to analyze the dynamic conditional correlations. Moreover, the Gumbel copula is employed to define the nonlinear structure of dependence and to evaluate the optimal portfolio. The conditional Value-at-Risk (CoVaR) is adopted as a risk measure. Findings indicate a long-run dependence and asymmetry of bidirectional risk spillover among oil price and exchange rate and confirm that the risk spillover intensity is different between the former and the latter. They show that the oil price has a stronger spillover effect in the case of oil exporting countries and the lowest spillover effect in the case of oil importing countries.
ν-Generalized Hyperbolic Distributions
Authors: Klebanov Lev , Rachev Svetlozar T.
Published: April 2023

A new class of probability distributions closely connected to generalized hyperbolic distributions is introduced. It is better adapted for studying the distributions of sums of a random number of random variables. The properties of these distributions are studied. It seems that this class may be useful for modeling asset returns.
Comparing the Trajectory of Urban Impervious Surface in Two Cities: The Case of Accra and Kumasi, Ghana
Authors: Bilintoh Thomas Mumuni , Korah Andrews , Opuni Antwi , Akansobe Adeline
Published: April 2023

In this study, we present methods to assess newly developed urban impervious surface (UIS) datasets derived from satellite imagery of the cities of Kumasi and Accra, Ghana, at three different time points. Each city has three binary maps from 2000, 2011, and 2021, in which one shows the presence of UIS and zero shows its absence. We employed the binaryTimeSeries method to compare the gross gains and losses in the two cities. In addition, we show how three components of change—quantity, allocation, and alternation—compare across the two sites. The results show that both cities experienced a large proportion of gains during the change in impervious surfaces between 2000 and 2011, and 2011 and 2021, with relatively smaller loss proportions and alternations. Comparatively, the results from the components of change show that change is fastest in Kumasi, which had a larger proportion of quantity gain. Our methods show an acceleration in UIS in the two cities during the temporal extent, and this trend is likely to continue with increasing urban populations. As a result, we recommend that the Land Use and Spatial Planning Authority, Town and Country Planning and other stakeholders make contingency plans to regulate the unplanned increase in UIS, since other studies have shown their negative effects on people and the environment.
Spatiotemporal Variation in the Yangtze River Delta Urban Agglomeration from 1980 to 2020 and Future Trends in Ecosystem Services
Authors: Wang Yongzheng , Gu Xinchen , Yu Haoran
Published: April 2023

Over the past 40 years of reform and opening up, human activities in the Yangtze River Delta region have caused major changes in land use patterns and ecosystem functions. Clarifying the spatiotemporal change characteristics and future development trends of ecosystem service functions is the basis for rational land development and utilization. In this study, the InVEST model and the CASA model were used to calculate habitat quality, water conservation, carbon sequestration and oxygen release, and soil conservation ecosystem services in the Yangtze River Delta urban agglomeration from 1980 to 2020. The spatial pattern, change law, and future trend of these services were analyzed using the Theil–Sen median trend analysis, Mann–Kendall test, and Hurst index analysis. The results show that the four types of ecosystems in the Yangtze River Delta urban agglomeration (habitat quality, water conservation, carbon sequestration and oxygen release, and soil conservation) exhibited an overall spatial pattern of being high in the southwest mountainous area and low in the northeast plain, and the conversion from constructed to agriculture was the most frequent type of land conversion over the past 40 years. From 1980 to 2020, the average level of habitat quality showed a downward trend and is expected to continue to deteriorate in the future. Water conservation, carbon sequestration and oxygen release, and soil conservation showed a fluctuating upward trend, with the latter two primarily predicted to have a future trend of improvement. The changes in ecosystem services exhibit gradient effects and horizontal spatial differentiation. The decline in ecosystem service functions is more pronounced in the vicinity of large cities. It is thus necessary to accelerate the transformation of the economic development model, and abandon the extensive urbanization development model, and promote high-quality urbanization development on the basis of improving resource and environmental carrying capacities.
Wetland Evolution and Driving Force Analysis in the Qingtongxia Reservoir Area
Authors: Li Qianwen , Jin Tiantian , Yang Jing , Zhao Qingxu , Peng Qidong , Lin Junqiang , Zhang Di
Published: April 2023

In recent years, the combination of river disruption and irrational human activities has caused serious damage to wetlands. Based on long-time-series remote-sensing images, this study applied the land use transfer matrix and landscape index method to investigate the dynamic evolution and driving forces of the Qingtongxia wetland in the upper reaches of the Yellow River from 1999 to 2020. The results show that the land use types of Qingtongxia wetland changed insignificantly from 1999 to 2020, with the area of water and grassland decreasing and the area of reed wetland, beach, farmland and forest increasing. The spatial changes in the watershed changed the distribution of other land uses within the wetland, with the watershed concentrating in a southwest–northeast direction and shrinking in the southwestern part of the wetland area between years. From 1999 to 2011, the wetlands were restored, the landscape became less fragmented and simpler in shape and the dominant species developed significantly. From 2010 to 2020, the wetlands were disturbed and, as a new tourist destination, the planning and renovation work increased fragmentation and the complexity of the patches. The complexity of the patch shape increased, and, at the same time, with the implementation of various conservation measures, the development of the dominant species within recovered. The drivers of change in the different land use areas within the wetlands of the Qingtongxia reservoir are dominated by flow, and the drivers of the evolution of landscape patterns within the wetlands are closely related to the population and gross regional product, in addition to being influenced by flow. In recent years, increased fragmentation has been the main reason for the decline in bird habitat quality. Maintaining bird diversity in the wetlands of the Qingtongxia reservoir can be based on rational planning of the proportion of different land uses within the wetlands, reducing landscape fragmentation by limiting human activities in the corresponding areas, as well as appropriate flow control measures. This study provides some reference for biodiversity conservation within wetlands.
Spatial Liminality as a Framework for Revitalising Dilapidated Abandoned Buildings in Historic Cities: A Case Study
Authors: Tavakoli Hamed , Hedayati Marzbali Massoomeh , Maghsoodi Tilaki Mohammad Javad
Published: April 2023

This paper develops the theory of liminality as a guideline for revitalising disused urban fabrics in historic cities. Since Middle Eastern historic cities exist as a transitional phenomenon, spatial liminality is identified as an epistemological tool for their investigation. This paper sets up a mixed-method approach based on questionnaire surveys and field studies in twelve urban blocks in historic Yazd and Kashan. Using an interpretive historical study, it is verified that, during the premodern eras, spatial liminality has been synonymous with the formation of sense of place/citizenship, mainly generated as a result of the existence of in-between spaces in historic cities, which, in turn, could have facilitated the rites of passage for residents. In a quantitative layer, the correlation between dilapidated abandoned buildings (DABs) (i.e., disused urban fabrics) and sense of place/citizenship is investigated in case studies, which unfolds associations that lack of sense of place amongst local communities could convey to the meaning of spatial liminality. The analysis demonstrates DABs are associated with lack of spatial liminality, contributing to the breakdown of sense of community identification/place. Therefore, DABs need to be reutilized while maintaining their heritage values. The discourse identifies in-between spaces that once facilitated spatial liminality and demonstrates a guideline for revitalising historic cities. This study put forward a theoretical contribution that enables the use of spatial liminality to guide the understanding and management of historic cities.
Ecological Risk Evaluation and Ecological Restoration Model of Mining in the Source Area of the Yellow River Basin
Authors: Xu Wenjia , Yao Weiling , Bai Zhongke , Yang Jinzhong , Li Li
Published: April 2023

Finding out about the ecosystem damaged by mining development and carrying out ecological risk diagnoses are important prerequisites for formulating mine ecological restoration strategies. This study established an integrated approach to quantitatively analyze mining ecological risks by combining water conservation and biodiversity conservation ecosystem service functions with natural ecological conditions, and based on these, proposes appropriate mine ecological restoration strategies. Results show that: (1) A total of 14,874.80 hm2 of ecosystems were damaged in the Qinghai section of the Yellow River Basin, caused by mining excavation, crushing and hollow collapse, and of which 52.10% were located in national important ecological function areas and National Nature Reserves, which caused a decrease of the important ecosystem service functions of water conservation and biodiversity conservation in the area, and aggravated the ecological risks of the river source area; (2) The areas of high ecological risk and comparatively high ecological risk in the research area are 1,093,800 hm2 and 902,100 hm2, which accounted for 7.27% and 6.00% of the land area, respectively. Ecological risk hotspot areas are mainly distributed in the Qilian Mountains, Hehuang Valley, Sanjiangyuan and other key water systems and water sources; (3) According to the principle of “one mine, one policy”, we propose five mine ecological restoration models: ecological reconstruction, artificial assistance and protection and conservation, artificial assistance, protection and conservation and natural restoration. This study provides a reliable basis for exploring the status of mining ecological risk at the source of the Yellow River and scientifically carrying out ecological restoration and risk management.
Increased Trypanosoma cruzi Growth during Infection of Macrophages Cultured on Collagen I Matrix
Authors: Logullo Jorgete , Diniz-Lima Israel , Rocha Juliana Dutra B. , Cortê-Real Suzana , Silva-Júnior Elias Barbosa da , Guimarães-de-Oliveira Joyce Cristina , Morrot Alexandre , Fonseca Leonardo Marques da , Freire-de-Lima Leonardo , Decote-Ricardo Debora , Freire-de-Lima Celio Geraldo
Published: April 2023

The interactions between cell and cellular matrix confers plasticity to each body tissue, influencing the cellular migratory capacity. Macrophages rely on motility to promote their physiological function. These phagocytes are determinant for the control of invasive infections, and their immunological role largely depends on their ability to migrate and adhere to tissue. Therefore, they interact with the components of the extracellular matrix through their adhesion receptors, conferring morphological modifications that change their shape during migration. Nevertheless, the need to use in vitro cell growth models with the conditioning of three-dimensional synthetic matrices to mimic the dynamics of cell-matrix interaction has been increasingly studied. This becomes more important to effectively understand the changes occurring in phagocyte morphology in the context of infection progression, such as in Chagas disease. This disease is caused by the intracellular pathogen Trypanosoma cruzi, capable of infecting macrophages, determinant cells in the anti-trypanosomatid immunity. In the present study, we sought to understand how an in vitro extracellular matrix model interferes with T. cruzi infection in macrophages. Using different time intervals and parasite ratios, we evaluated the cell morphology and parasite replication rate in the presence of 3D collagen I matrix. Nevertheless, microscopy techniques such as scanning electron microscopy were crucial to trace macrophage-matrix interactions. In the present work, we demonstrated for the first time that the macrophage-matrix interaction favors T. cruzi in vitro replication and the release of anti-inflammatory cytokines during macrophage infection, in addition to drastically altering the morphology of the macrophages and promoting the formation of migratory macrophages.
Comparing the Impact of COVID-19 on Vaccinated and Unvaccinated Patients Affected by Myasthenia Gravis
Authors: Scarsi Elena , Massucco Sara , Ferraro Pilar M. , Cella Arianna , Grisanti Stefano G. , Assini Andrea , Beronio Alessandro , Della Cava Fabio , Gemelli Chiara , Bandini Fabio , Serrati Carlo , Del Sette Massimo , Schenone Angelo , Benedetti Luana , Prada Valeria , Grandis Marina
Published: April 2023

We evaluated 13 patients affected by myasthenia gravis (MG) who had coronavirus disease 2019 (COVID-19) before vaccination and 14 myasthenic patients who contracted severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection after vaccination to evaluate factors related to different COVID-19 outcomes. We compared the two groups’ previous stability of MG and the severity of SARS-CoV-2 infection. Vaccinated and non-vaccinated patients were comparable in terms of severity of the previous MG course (mean maximum myasthenia gravis Foundation of America–MGFA–Class III) and during SARS-CoV-2 infection (mean MGFA Class II). In non-vaccinated patients, the hospitalization and severe course percentages were 61.5%, while the mortality reached 30.8%. The hospitalization, severe course, and mortality percentages in vaccinated patients were 7.1%. In deceased, non-vaccinated patients, greater myasthenia severity in the past clinical history, but not at the time of infection, was observed. Similarly, older age at MG onset and at the time of infection correlated with a more severe COVID-19 course in non-vaccinated patients (p = 0.03 and p = 0.04), but not in the group of vaccinated patients. In summary, our data support a protective role of vaccination in myasthenic patients, even if anti-CD20 therapy might be associated with a poor immune response to vaccines.
Celecoxib, a Non-Steroidal Anti-Inflammatory Drug, Exerts a Toxic Effect on Human Melanoma Cells Grown as 2D and 3D Cell Cultures
Authors: Venuta Alessandro , Nasso Rosarita , Gisonna Armando , Iuliano Roberta , Montesarchio Sara , Acampora Vittoria , Sepe Leandra , Avagliano Angelica , Arcone Rosaria , Arcucci Alessandro , Ruocco Maria Rosaria
Published: April 2023

Cutaneous melanoma (CM) remains one of the leading causes of tumor mortality due to its high metastatic spread. CM growth is influenced by inflammation regulated by prostaglandins (PGs) whose synthesis is catalyzed by cyclooxygenases (COXs). COX inhibitors, including non-steroidal anti-inflammatory drugs (NSAIDs), can inhibit tumor development and growth. In particular, in vitro experiments have shown that celecoxib, a NSAID, inhibits the growth of some tumor cell lines. However, two-dimensional (2D) cell cultures, used in traditional in vitro anticancer assays, often show poor efficacy due to a lack of an in vivo like cellular environment. Three-dimensional (3D) cell cultures, such as spheroids, are better models because they can mimic the common features displayed by human solid tumors. Hence, in this study, we evaluated the anti-neoplastic potential of celecoxib, in both 2D and 3D cell cultures of A2058 and SAN melanoma cell lines. In particular, celecoxib reduced the cell viability and migratory capability and triggered the apoptosis of melanoma cells grown as 2D cultures. When celecoxib was tested on 3D melanoma cell cultures, the drug exerted an inhibitory effect on cell outgrowth from spheroids and reduced the invasiveness of melanoma cell spheroids into the hydrogel matrix. This work suggests that celecoxib could represent a new potential therapeutic approach in melanoma therapy.
Numerical Prediction of Microstructure Evolution of Small-Diameter Stainless Steel Balls during Cold Skew Rolling
Authors: Zhou Jing , Liu Shengqiang , Wang Baoyu , Xu Hao
Published: April 2023

The wear resistance and hardness of stainless steel (SS) balls formed by cold skew rolling are effectively improved due to the change in internal microstructure. In this study, based on the deformation mechanism of 316L stainless steel, a physical mechanism-based constitutive model was established and implemented in a subroutine of Simufact to investigate the microstructure evolution of 316L SS balls during the cold skew rolling process. The evolution of equivalent strain, stress, dislocation density, grain size, and martensite content was studied via simulation during the steel balls’ cold skew rolling process. The corresponding skew rolling experiments of steel balls were carried out to verify the accuracy of the finite element (FE) model results. The results showed that the macro dimensional deviation of steel balls fluctuates less, and the microstructure evolution agrees well with the simulation results, which proves that the established FE model has high credibility. It shows that the FE model, coupled with multiple deformation mechanisms, provides a good prediction of the macro dimensions and internal microstructure evolution of small-diameter steel balls during cold skew rolling.
Accelerating the Gas–Solid Interactions for Conductometric Gas Sensors: Impacting Factors and Improvement Strategies
Authors: Zhao Hongchao , Wang Yanjie , Zhou Yong
Published: April 2023

Metal oxide-based conductometric gas sensors (CGS) have showcased a vast application potential in the fields of environmental protection and medical diagnosis due to their unique advantages of high cost-effectiveness, expedient miniaturization, and noninvasive and convenient operation. Of multiple parameters to assess the sensor performance, the reaction speeds, including response and recovery times during the gas–solid interactions, are directly correlated to a timely recognition of the target molecule prior to scheduling the relevant processing solutions and an instant restoration aimed for subsequent repeated exposure tests. In this review, we first take metal oxide semiconductors (MOSs) as the case study and conclude the impact of the semiconducting type as well as the grain size and morphology of MOSs on the reaction speeds of related gas sensors. Second, various improvement strategies, primarily including external stimulus (heat and photons), morphological and structural regulation, element doping, and composite engineering, are successively introduced in detail. Finally, challenges and perspectives are proposed so as to provide the design references for future high-performance CGS featuring swift detection and regeneration.
An Electrochemical Sensor for the Determination of Trace Concentrations of Cadmium, Based on Spherical Glassy Carbon and Nanotubes
Authors: Grabarczyk Malgorzata , Wardak Cecylia , Piech Robert , Wawruch Agnieszka
Published: April 2023

The practical application of a novel, eco-friendly electrochemical sensor based on low-dimensional structures, spherical glassy carbon microparticles, and multiwall carbon nanotubes is described. This sensor, modified with a bismuth film, was used for the determination of Cd(II) by the anodic stripping voltammetric method. The instrumental and chemical factors influencing the sensitivity of the procedure were thoroughly investigated and their most favorable values were selected (acetate buffer solution pH = 3 ± 0.1; 0.15 mmol L−1 Bi(III); activation potential/time: −2 V/3 s; accumulation potential/time: −0.9 V/50 s). Under the selected conditions, the method exhibited linearity in the range of 2 × 10−9 to 2 × 10−7 mol L−1 Cd(II) with a detection limit of 6.2 × 10−10 mol L−1 Cd(II). The results obtained also showed that the application of the sensor for Cd(II) detection did not experience any significant interference in the presence of a number of foreign ions. The applicability of this procedure was evaluated using TM-25.5 Environmental Matrix Reference Material and SPS-WW1 Waste Water Certified Reference Material as well as river water samples through addition and recovery tests.
Measurement and Analysis of Magnetic Properties of Permalloy for Magnetic Shielding Devices under Different Temperature Environments
Authors: Sun Jinji , Ren Jianyi , Li Jin , Huang Yuejing
Published: April 2023

The relative permeability, coercivity, and remanence of permalloy are closely related to the performance of magnetic shielding devices. In this paper, the relationship between the magnetic properties of permalloy and the working temperature of magnetic shielding devices is measured. Firstly, the measurement method of permalloy properties based on the simulated impact method is analyzed. What is more, a magnetic property test system consisting of a soft magnetic material tester and a high–low temperature chamber for permalloy ring samples at different temperatures was established to measure DC and AC (0.01 Hz to 1 kHz) magnetic properties at different temperatures (−60 °C to 140 °C). Finally, the results show that compared with room temperature (25 °C), the initial permeability (μi) decreases by 69.64% at −60 °C and increases by 38.23% at 140 °C, and the coercivity (hc) decreases by 34.81% at −60 °C and increases by 8.93% at 140 °C, which are the key parameters in the magnetic shielding device. It can be concluded that the relative permeability and remanence of permalloy are positively correlated with temperature, while the saturation magnetic flux density and coercivity are negatively correlated with temperature. This paper is of great significance to the magnetic analysis and design of magnetic shielding devices.
Multi-Physical Field Simulation of Cracking during Crystal Growth by Bridgman Method
Authors: He Xinke , Li Linnong , He Xinqi , Xie Chao
Published: April 2023

Crystal materials are prone to cracking during growth, which is a key problem leading to slow growth and difficulty in forming large-size crystals. In this study, based on the commercial finite element software COMSOL Multiphysics, the transient finite element simulation of the multi-physical field, including fluid heat transfer—phase transition—solid equilibrium—damage coupling behaviors, is performed. The phase-transition material properties and maximum tensile strain damage variables are customized. Using the re-meshing technique, the crystal growth and damage are captured. The results show the following: The convection channel at the bottom of the Bridgman furnace greatly influences the temperature field inside the furnace, and the temperature gradient field significantly influences the solidification and cracking behaviors during crystal growth. The crystal solidifies faster when it enters the higher-temperature gradient region and is prone to cracking. The temperature field inside the furnace needs to be properly adjusted so that the crystal temperature decreases relatively uniformly and slowly during the growth process to avoid crack formation. In addition, the crystal growth orientation also significantly affects the nucleation and growth direction of cracks. Crystals grown along the a-axis tend to form long cracks starting from the bottom and growing vertically, while crystals grown along the c-axis induce the laminar cracks from the bottom in a horizontal direction. The numerical simulation framework of the damage during crystal growth, which can accurately simulate the process of crystal growth and crack evolution and can be used to optimize the temperature field and crystal growth orientation in the Bridgman furnace cavity, is a reliable method to solve the crystal cracking problem.
Study on Concave Direction Impact Performance of Similar Concave Hexagon Honeycomb Structure
Authors: Zhao Guanxiao , Fu Tao , Li Jiaxing
Published: April 2023

Based on the traditional concave hexagonal honeycomb structure, three kinds of concave hexagonal honeycomb structures were compared. The relative densities of traditional concave hexagonal honeycomb structures and three other classes of concave hexagonal honeycomb structures were derived using the geometric structure. The impact critical velocity of the structures was derived by using the 1-D impact theory. The in-plane impact characteristics and deformation modes of three kinds of similar concave hexagonal honeycomb structures in the concave direction at low, medium, and high velocity were analyzed using the finite element software ABAQUS. The results showed that the honeycomb structure of the cells of the three types undergoes two stages: concave hexagons and parallel quadrilaterals, at low velocity. For this reason, there are two stress platforms in the process of strain. With the increase in the velocity, the joints and middle of some cells form a glue-linked structure due to inertia. No excessive parallelogram structure appears, resulting in the blurring or even disappearance of the second stress platform. Finally, effects of different structural parameters on the plateau stress and energy absorption of structures similar to concave hexagons were obtained during low impact. The results provide a powerful reference for the negative Poisson’s ratio honeycomb structure under multi-directional impact.