bluuebunny/crossref_metadata_2025 huggingface dataset:
Subgingival Periopathogens Assessment and Clinical Periodontal Evaluation of Gastric Cancer Patients—A Cross Sectional Pilot Study
Authors: Nicolae Flavia Mirela , Didilescu Andreea Cristiana , Șurlin Petra , Ungureanu Bogdan Silviu , Șurlin Valeriu Marin , Pătrașcu Ștefan , Ramboiu Sandu , Jelihovschi Igor , Iancu Luminita Smaranda , Ghilusi Mirela , Cucu Mihai , Gheonea Dan Ionuț
Published: March 2022

Oral microbiota have shown a higher bacterial diversity in patients with cancers of the digestive tract, with higher levels of periopathogens. Recent studies have shown that Fusobacterium links to gastro-intestinal neoplastic tissue and accelerates its progression, as well as worsening patient outcome. The present pilot study was carried out between February and December 2020 to evaluate the possible association between the abundance of some periopathogens (Fusobacterium nucleatum, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola and Tannerella forsythia) in subgingival plaque and periodontal status with characteristics of gastric cancer. The study was performed on a sample of 24 patients with gastric cancer from the 1st Department of Surgery and Department of Gastroenterology within the Clinical County Hospital of Emergency of Craiova, Romania. The patients’ oral cavity was examined, gingival crevicular samples were collected, and signs of periodontal disease were recorded. On the histopathological exam, the differentiation grade and size of the tumour were registered. Our results showed that, from the periopathogens studied, the most abundant bacteria were F. nucleatum followed by T. forsythia in all groups. In our present study, the strong correlation between tumour dimension and all periodontal parameters but also between tumour dimension and F. nucleatum could suggest a positive association between periodontal disease, tumoral growth and periopathogens implication in this process.
Assay for Evaluating the Abundance of Vibrio cholerae and Its O1 Serogroup Subpopulation from Water without DNA Extraction
Authors: Nasreen Tania , Hussain Nora A.S. , Ho Jia Yee , Aw Vanessa Zhi Jie , Alam Munirul , Yanow Stephanie K. , Boucher Yann F.
Published: March 2022

Cholera is a severe diarrheal disease caused by Vibrio cholerae, a natural inhabitant of brackish water. Effective control of cholera outbreaks depends on prompt detection of the pathogen from clinical specimens and tracking its source in the environment. Although the epidemiology of cholera is well studied, rapid detection of V. cholerae remains a challenge, and data on its abundance in environmental sources are limited. Here, we describe a sensitive molecular quantification assay by qPCR, which can be used on-site in low-resource settings on water without the need for DNA extraction. This newly optimized method exhibited 100% specificity for total V. cholerae as well as V. cholerae O1 and allowed detection of as few as three target CFU per reaction. The limit of detection is as low as 5 × 103 CFU/L of water after concentrating biomass from the sample. The ability to perform qPCR on water samples without DNA extraction, portable features of the equipment, stability of the reagents at 4 °C and user-friendly online software facilitate fast quantitative analysis of V. cholerae. These characteristics make this assay extremely useful for field research in resource-poor settings and could support continuous monitoring in cholera-endemic areas.
Impact of Pharmacokinetic and Pharmacodynamic Properties of Monoclonal Antibodies in the Management of Psoriasis
Authors: Rodríguez-Fernández Karine , Mangas-Sanjuán Víctor , Merino-Sanjuán Matilde , Martorell-Calatayud Antonio , Mateu-Puchades Almudena , Climente-Martí Mónica , Gras-Colomer Elena
Published: March 2022

The treatment of psoriasis has been revolutionized by the emergence of biological therapies. Monoclonal antibodies (mAb) generally have complex pharmacokinetic (PK) properties with nonlinear distribution and elimination. In recent years, several population pharmacokinetic/pharmacodynamic (PK/PD) models capable of describing different types of mAb have been published. This study aims to summarize the findings of a literature search about population PK/PD modeling and therapeutic drug monitoring (TDM) of mAb in psoriasis. A total of 22 articles corresponding to population PK/PD models of tumor necrosis factor (TNF)-α inhibitors (adalimumab and golimumab), interleukin (IL)-23 inhibitors (guselkumab, tildrakizumab, and risankizumab), IL-23/IL-12 inhibitor (ustekinumab), and IL-17 inhibitors (secukinumab, ixekizumab, and brodalumab) were collected. A summary of the clinical trials conducted so far in psoriasis was included, together with the current structural population PK and PD models. The most significant and clinical covariates were body weight (BW) and the presence of immunogenicity on clearance (CL). The lack of consensus on PK/PD relationships has prevented establishing an adequate dosage and, therefore, accentuates the need for TDM in psoriasis.
An Evaluation of CXCR4 Targeting with PAMAM Dendrimer Conjugates for Oncologic Applications
Authors: Lesniak Wojciech G. , Azad Babak Behnam , Chatterjee Samit , Lisok Ala , Pomper Martin G.
Published: March 2022

The chemokine receptor 4 (CXCR4) is a promising diagnostic and therapeutic target for the management of various cancers. CXCR4 has been utilized in immunotherapy, targeted drug delivery, and endoradiotherapy. Poly(amidoamine) [PAMAM] dendrimers are well-defined polymers with unique properties that have been used in the fabrication of nanomaterials for several biomedical applications. Here, we describe the formulation and pharmacokinetics of generation-5 CXCR4-targeted PAMAM (G5-X4) dendrimers. G5-X4 demonstrated an IC50 of 0.95 nM to CXCR4 against CXCL12-Red in CHO-SNAP-CXCR4 cells. Single-photon computed tomography/computed tomography imaging and biodistribution studies of 111In-labeled G5-X4 showed enhanced uptake in subcutaneous U87 glioblastoma tumors stably expressing CXCR4 with 8.2 ± 2.1, 8.4 ± 0.5, 11.5 ± 0.9, 10.4 ± 2.6, and 8.8 ± 0.5% injected dose per gram of tissue at 1, 3, 24, 48, and 120 h after injection, respectively. Specific accumulation of [111In]G5-X4 in CXCR4-positive tumors was inhibited by the peptidomimetic CXCR4 inhibitor, POL3026. Our results demonstrate that while CXCR4 targeting is beneficial for tumor accumulation at early time points, differences in tumor uptake are diminished over time as passive accumulation takes place. This study further confirms the applicability of PAMAM dendrimers for imaging and therapeutic applications. It also emphasizes careful consideration of image acquisition and/or treatment times when designing dendritic nanoplatforms for tumor targeting.
Neural Network-Based Transceiver Design for VLC System over ISI Channel
Authors: Li Lin , Zhu Zhaorui , Zhang Jian
Published: March 2022

In this letter, we construct the neural network (NN)-based transceiver to compensate for the varying inter-symbol-interference (ISI) effect in visible light communication (VLC) systems. For processing variable-length sequences, the convolution neural network (CNN) is utilized, and then the residual network structure is further leveraged at the receiver part to enhance the performance. To cope with varying ISI, the pilot sequence, instead of channel side information (CSI) obtained by an additional module, is integrated into the framework to recover the data sequence directly. Simulation results show that the symbol error rate (SER) performance of the proposed NN-based transceiver can outperform separately designed transceiver schemes and approach the ideal perfect CSI (PCSI) case with a few pilot symbols or even no pilot.
Increasing the Storability of Fresh-Cut Green Beans by Using Chitosan as a Carrier for Tea Tree and Peppermint Essential Oils and Ascorbic Acid
Authors: Abdelgawad Karima F. , Awad Asmaa H. R. , Ali Marwa R. , Ludlow Richard A. , Chen Tong , El-Mogy Mohamed M.
Published: March 2022

The quality of fresh-cut green beans deteriorates rapidly in storage, which contributes to increased food waste and lower perceived customer value. However, chitosan (Cs) and certain plant essential oils show promise in reducing postharvest quality loss during storage. Here, the effect of Cs and the combinations of Cs + tea tree oil (TTO), Cs +x peppermint oil (PMO), and Cs + ascorbic acid (AsA) on the quality of fresh-cut green bean pods (FC-GB) is studied over a 15-d storage period at 5 °C. All four FC-GB treatments reduced weight loss and maintained firmness during storage when compared to uncoated FC-GB. Furthermore, all treatments showed higher total chlorophyll content, AsA, total phenolic compounds, and total sugars compared to the control. The best treatment for reducing microbial growth was a combination of Cs + AsA. Additionally, the combination of Cs with TTO, PMO, or AsA showed a significant reduction in the browning index and increased the antioxidant capacity of FC-GB up to 15 d postharvest.
Fundamental Chemistry of Essential Oils and Volatile Organic Compounds, Methods of Analysis and Authentication
Authors: Sadgrove Nicholas , Padilla-González Guillermo , Phumthum Methee
Published: March 2022

The current text provides a comprehensive introduction to essential oils, their biosynthesis, naming, analysis, and chemistry. Importantly, this text quickly brings the reader up to a level of competence in the authentication of essential oils and their components. It gives detailed descriptions of enantiomers and other forms of stereoisomers relevant to the study of natural volatiles and essential oils. The text also describes GC-MS work and provides tips on rapid calculation of arithmetic indices, how to interpret suggested names from the NIST mass spectral library, and what additional efforts are required to validate essential oils and defeat sophisticated adulteration tactics. In brief, essential oils are mixtures of volatile organic compounds that were driven out of the raw plant material in distillation, condensed into an oil that is strongly aroma emitting, and collected in a vessel as the top layer (uncommonly bottom layer) of two phase separated liquids: oil and water. Essential oils commonly include components derived from two biosynthetic groups, being terpenes (monoterpenes, sesquiterpenes and their derivatives) and phenylpropanoids (aromatic ring with a propene tail). The current text provides details of how terpenes and phenylpropanoids are further categorised according to their parent skeleton, then recognised by the character of oxidation, which may be from oxygen, nitrogen, or sulphur, or the presence/absence of a double bond. The essential oil’s science niche is an epicentre of individuals from diverse backgrounds, such as aromatherapy, pharmacy, synthetic and analytical chemistry, or the hobbyist. To make the science more accessible to the curious student or researcher, it was necessary to write this fundamentals-level introduction to the chemistry of essential oils (i.e., organic chemistry in the context of essential oils), which is herein presented as a comprehensive and accessible overview. Lastly, the current review constitutes the only resource that highlights common errors and explains in simplistic detail how to correctly interpret GC-MS data then accurately present the respective chemical information to the wider scientific audience. Therefore, detailed study of the contents herein will equip the individual with prerequisite knowledge necessary to effectively analyse an essential oil and make qualified judgement on its authenticity.
Near-Infrared-Light-Assisted Self-Healing Graphene-Thermopolyurethane Composite Films
Authors: Wang Yuehui , Zhou Zhimin , Li Sixing , Zheng Han , Lu Jiaxin , Wang Shuyue , Zhang Jiahao , Wang Ke , Lin Kaiwen
Published: March 2022

Graphene-thermopolyurethane (G-TPU) composite films were fabricated and the effects of the TPU initial concentration, characteristics of TPU, and graphene loading on the electrical, mechanical, thermal, infrared thermal response and near-infrared-light-assisted self-healing properties of the composite films were investigated in detail. The experimental results demonstrate that the comprehensive performances of the composite film are related to the initial concentration of the TPU solution and the characteristics of the TPU and the graphene loading. The composite film prepared from TPU solution with low initial concentration can have conductivity under the condition of low graphene content. However, the composite film prepared with appropriate initial concentration of TPU solution and high graphene loading is conducive to obtain high conductivity. After 60 s of near-infrared illumination, the temperature of the composite film first increases and then decreases with the increase in graphene loading until it reaches saturation. The near-infrared light thermal response of the composite film with high graphene loading is related to the initial concentration of TPU solution, while the near-IR thermal response of the composite film with low graphene loading is independent of the initial concentration of TPU. The surface micro-cracks of the composite film almost disappeared after 10 min of near-infrared illumination. The resistance of the conductive composite film increases after healed. The composite film prepared with low melting point TPU is more favorable to obtain high near-IR thermal self-healing efficiency.
Tapered Waist Tensile Specimens for Evaluating Butt Fusion Joints of Polyethylene Pipes—Part 1: Development
Authors: Kim Sunwoo , Eom Taemin , Lee Wonjae , Choi Sunwoong
Published: March 2022

The structural integrity of butt fusion (BF) joints in thermoplastic pressure piping systems is critical to their long-term safe use. The tapered waist tensile (TWT) specimen was developed to alleviate issues associated with ISO 13953 waisted tensile (WT) specimen for evaluating BF joints. Experimental and finite element analyses were performed to obtain optimum TWT specimen designs for the BF joint destructive test. For TWT specimens, depending on the pipe size, the displacement at onset necking was reduced by 30~100%, and the tested BF area increased by 60~80% compared to the WT specimen. In addition, the transverse specimen deflection was lower thus providing better experimental stability. Furthermore, it showed the same BF displacement at the maximum force local to the BF bead, indicating that the tapered waist geometry provides equivalent deformation constraint and BF failure mode designed for the BF joint in the WT specimens. Therefore, TWT specimens offer simplicity, adaptability, stability, and accuracy in specimen preparation, testing, and analysis compared to WT specimens.
Control of Photoinduced Electron Transfer Using Complex Formation of Water-Soluble Porphyrin and Polyvinylpyrrolidone
Authors: Cao Yilin , Takasaki Tomoe , Yamashita Satoshi , Mizutani Yasuhisa , Harada Akira , Yamaguchi Hiroyasu
Published: March 2022

Inspired by the natural photosynthetic system in which proteins control the electron transfer from electron donors to acceptors, in this research, artificial polymers were tried to achieve this control effect. Polyvinylpyrrolidone (PVP) was found to form complex with pigments 5,10,15,20-tetrakis-(4-sulfonatophenyl) porphyrin (TPPS) and its zinc complex (ZnTPPS) quantitatively through different interactions (hydrogen bonds and coordination bonds, respectively). These complex formations hinder the interaction between ground-state TPPS or ZnTPPS and an electron acceptor (methyl viologen, MV2+) and could control the photoinduced electron transfer from TPPS or ZnTPPS to MV2+, giving more electron transfer products methyl viologen cationic radical (MV+•). Other polymers such as PEG did not show similar results, indicating that PVP plays an important role in controlling the photoinduced electron transfer.
The Influence of Colloidal Properties of Carbon Black on Static and Dynamic Mechanical Properties of Natural Rubber
Authors: Kyei-Manu William Amoako , Herd Charles R. , Chowdhury Mahatab , Busfield James J. C. , Tunnicliffe Lewis B.
Published: March 2022

The influence of carbon black (CB) structure and surface area on key rubber properties such as monotonic stress-strain, cyclic stress–strain, and dynamic mechanical behaviors are investigated in this paper. Natural rubber compounds containing eight different CBs were examined at equivalent particulate volume fractions. The CBs varied in their surface area and structure properties according to a wide experimental design space, allowing robust correlations to the experimental data sets to be extracted. Carbon black structure plays a dominant role in defining the monotonic stress–strain properties (e.g., secant moduli) of the compounds. In line with the previous literature, this is primarily due to strain amplification and occluded rubber mechanisms. For cyclic stress–strain properties, which include the Mullins effect and cyclic softening, the observed mechanical hysteresis is strongly correlated with carbon black structure, which implies that hysteretic energy dissipation at medium to large strain values is isolated in the rubber matrix and arises due to matrix overstrain effects. Under small to medium dynamic strain conditions, classical strain dependence of viscoelastic moduli is observed (the Payne effect), the magnitude of which varies dramatically and systematically depending on the colloidal properties of the CB. At low strain amplitudes, both CB structure and surface area are positively correlated to the complex moduli. Beyond ~2% strain amplitude the effect of surface area vanishes, while structure plays an increasing and eventually dominant role in defining the complex modulus. This transition in colloidal correlations reflects the transition in stiffening mechanisms from flexing of rigid percolated particle networks at low strains to strain amplification at medium to high strains. By rescaling the dynamic mechanical data sets to peak dynamic stress and peak strain energy density, the influence of CB colloidal properties on compound hysteresis under strain, stress, and strain energy density control can be estimated. This has considerable significance for materials selection in rubber product development.
Ionic Liquids as Homogeneous Catalysts for Glycerol Oligomerization
Authors: Kansy Dawid , Czaja Krystyna , Bosowska Kornelia , Groch Paweł
Published: March 2022

Ionic liquids (ILs) were used for the first time as catalysts for the glycerin condensation reaction. A series of imidazolium and ammonium ionic liquids differing in the length of the alkyl substituent (C2, C12, and C14) and the type of anion (Br−, CH3COO−, and NaHPO4−) were synthesized using a typical two-step method. The structure of the obtained ILs was confirmed by nuclear magnetic resonance 13C NMR, and their base power was determined on the basis of the Hammett function. The oligomerization of glycerin with the participation of the obtained ionic liquids and, for comparison, in the presence of a homogeneous basic catalyst Na2CO3, was carried out for 3 h at 180 °C, under a pressure of 0.4 bar, where the highest conversion, i.e., 92%, was obtained against 1-dodecyl-N,N,N-triethylammonium acetate. The course of the reaction was monitored using a reaction system coupled with a FTIR spectrometer, which allowed for the tracking of changes in product concentration over time and the assessment of glycerin oligomerization kinetics. The reaction products were analyzed by positive electrospray ionization mass spectrometry (ESI-MS), 13C NMR, and infrared absorption spectroscopy (FTIR).
Experimental Investigation and Numerical Simulation of a Self-Wiping Corotating Parallel Octa-Screw Extruder
Authors: Liu Cheng-Ying , Mikoshiba Shota , Kobayashi Yutaka , Ishigami Akira , Yorifuji Daisuke , Tanifuji Shin-ichiro , Ito Hiroshi
Published: March 2022

An octa-screw extruder (OSE) is equipment for pelletizing, blending, and mixing polymers and composites. In this study, the degree of resin filling, residence time distribution (RTD) of molten resin, and temperature profile in the octa-screw extruder were evaluated both experimentally and numerically. An intermeshing corotating parallel octa-screw kneading extruder was used for the experiments. For the comparison study, the results obtained from this extruder were compared with the twin-screw extruder. High-density polyethylene was selected as the material for extrusion. Meanwhile, a numerical code, based on a 2.5 D finite element method derived from the Hele–Shaw flow model, was developed to simulate the octa-screw extrusion process. The empirical outcomes suggest that octa-screw extrusion exhibited a narrower RTD of the molten resin compared with the twin-screw extrusion, suggesting better extrudate quality. The octa-screw extrusion also showed a lower temperature profile than twin-screw extrusion. The results of the simulation were also found to be in good agreement with experimental measurements. Experimental and numerical investigations of an OSE enable detailed comprehension and visualization of resin distribution in the entire length of the OSE, thus providing advantages in terms of process optimization.
CAD/CAM Diagnostic Esthetic Functional Splint (DEFS) as a Removable Prototype to Evaluate the Final Prosthetic Rehabilitation: A Narrative Review
Authors: Zarone Fernando , Sorrentino Roberto , Sorrentino Francesca , Di Mauro Maria Irene , Edelhoff Daniel
Published: March 2022

The main objective of this narrative review was to provide an overview of DEFS (Diagnostic Esthetic Functional Splint), namely CAD/CAM manufactured, “snap-retained”, tooth-colored splints available by materials exhibiting a certain degree of elasticity (like polycarbonates or acetal resins) for restoring function, esthetics and occlusion in several clinical situations, before or as an intermediate alternative to undergoing the final treatment. The search strategy included all papers dealing with snap-retained prosthetic systems and was based on a literature review of papers available in electronic databases (Pubmed/Medline, Evidence-Based Dentistry, BMJ Evidence-Based Medicine, Dynamed, Embase, BMJ Clinical Evidence, Web of Science, Scientific reports); eligible papers were researched on Opengreyand a manual search was performed, as well. From the electronic databases emerged 13,199 records, many of which were duplicates. The grey literature and the manual research did not produce any eligible article. After duplicates removal, 7690 records were obtained. Titles, abstracts and keywords were analyzed. The studies concerning the topic of interest were examined by the reviewers and discussed. Although no evidence-based data were found in the literature, according to the authors’ clinical experience, the DEFS (Diagnostic Esthetic Functional Splint) is a very promising solution in multiple clinical situations, due to its diagnostic, therapeutical, functional and esthetic versatility.
Kurds, Jews, and Kurdistani Jews: Historic Homelands, Perceptions of Parallels in Persecution, and Allies by Analogy
Authors: Khezri Haidar
Published: March 2022

This article highlights the positive relations between the Jewish and the Kurdish nations, maintained mainly by Kurdistani Jews until their displacement to Israel in the mid-20th century. These positive relations have been transmitted through their oral traditions, documented by both communities and travelers to Kurdistan, and validated by several scholars who studied the Jews of the region, Kurdistan, and Jewish-Kurdish relations. The dearth of historical documentation of both societies has resulted in a ‘negative myth’ used by the enemies of the Kurds and the Jews to dehumanize them before the 20th century, and therefore delegitimizing their right to statehood in modern times. From the 16th century onward, there is more solid evidence about the Kurdistani Jews and their relations with Kurdish neighbors. There are considerable and certain parallels between the two nations in terms of their oral traditions as well as linguistic and literary practices. The historical ties between the Jews and their neighbors in Kurdistan formed a fruitful ground for the relations between the Jewish people of Israel and the Kurds since 1948. Despite the exodus of almost the entire Kurdistani Jewish population to the State of Israel, Kurdistani Jews have largely retained their identity, culture, and traditions and have effectively influenced Israel’s policy towards the Kurds. The often-secret relations between the Kurdish movement in Iraq and Israel since 1960 played an important role in the global security policy of the Jewish nation in the Middle East, and in effect served to keep Baghdad from becoming involved in the Arab-Israeli conflict on one hand, and allowed the Kurdish liberation movement in Southern/Iraqi Kurdistan to survive on the other. These ties were reinforced by the sense of a common fate and struggle for statehood, persecution and genocides, feeling of solidarity, mutual strategic interests, humanitarian and economic dimensions, in post-1988 Halabja Massacre, the operation of the US led coalition against Iraq in 1991, and 2003 Invasion of Iraq. Since the Arab Spring, the military interventions against the self-proclaimed caliphate, Islamic State (IS), and the referendum for an independent Kurdish state in northern Iraq in 2017, this relationship allegedly has extended to include the relationships between Israel and the Kurds in Western/Syrian and Eastern/Iranian Kurdistan as well. Notably, Israel was the only state that publicly supported the creation of an independent Kurdish state. With all the development the Kurdish question has paved in the 21st century, the article concludes that the majority of the Kurds of the 21st century can be described as a ‘pariah people’ in Max Weber’s definition and meditation of the term and Hannah Arendt’s ‘rightless’, who ‘no longer belong to any community’, while describing the different aspects of the political, economic, and cultural calamity of Jews, refugees, and stateless people at the beginning of the 20th century.
A Block Shuffle Network with Superpixel Optimization for Landsat Image Semantic Segmentation
Authors: Yang Xuan , Chen Zhengchao , Zhang Bing , Li Baipeng , Bai Yongqing , Chen Pan
Published: March 2022

In recent years, with the development of deep learning in remotely sensed big data, semantic segmentation has been widely used in large-scale landcover classification. Landsat imagery has the advantages of wide coverage, easy acquisition, and good quality. However, there are two significant challenges for the semantic segmentation of mid-resolution remote sensing images: the insufficient feature extraction capability of deep convolutional neural network (DCNN); low edge contour accuracy. In this paper, we propose a block shuffle module to enhance the feature extraction capability of DCNN, a differentiable superpixel branch to optimize the feature of small objects and the accuracy of edge contours, and a self-boosting method to fuse semantic information and edge contour information to further optimize the fine-grained edge contour. We label three sets of Landsat landcover classification datasets, and achieved an overall accuracy of 86.3%, 83.2%, and 73.4% on the three datasets, respectively. Compared with other mainstream semantic segmentation networks, our proposed block shuffle network achieves state-of-the-art performance, and has good generalization ability.
Influence of Residual Amplitude and Phase Error for GF-3 Quad-Polarization SAR on Wind Vector Retrieval
Authors: Wang Xiaochen , Hu Yuxin , Han Bing , Yuan Xinzhe , Yang Junxin , Duan Jitong
Published: March 2022

High-resolution wind vector is important to investigate local winds’ variability over the global ocean. Quad-polarization Synthetic Aperture Radar (SAR) can provide wind vector independently without any external wind direction inputs. Although quad-polarization SAR wind retrieval algorithms have been widely studied, improvements are still required. The amplitude and phase imbalance of polarization channel cannot be neglected for improving the wind vector retrieval precision. In this study, rainforest was performed to remove the amplitude and phase imbalance of polarization channel of GF-3 SAR. To explore the applicability of this method for sea surface measurement, the influence of residual amplitude and phase error for GF-3 quad-polarization SAR on wind vector retrieval was assessed. Variation of amplitude and phase imbalance of sea surface for transmit and receive channel were assessed against collocated wind speed and incidence angle. Considering the polarization difference of VV channel relative to HH channel, the residual amplitude and phase error was found to be closely related to wind speed and polarization isolation. Correction of residual amplitude and phase error were employed to improve the retrieval precision of wind vector. It is revealed that the wind speed retrieval precision of VV polarization improved with correction of residual amplitude error. In addition, the influence of residual amplitude and phase error on wind direction retrieval can be neglected. Thus, it is concluded that correction of amplitude and phase error has the potential to improve wind vector retrievals from GF-3 quad-polarization SAR.
DIC-ST: A Hybrid Prediction Framework Based on Causal Structure Learning for Cellular Traffic and Its Application in Urban Computing
Authors: Zhang Kaisa , Chuai Gang , Zhang Jinxi , Chen Xiangyu , Si Zhiwei , Maimaiti Saidiwaerdi
Published: March 2022

The development of technology has strongly affected regional urbanization. With development of mobile communication technology, intelligent devices have become increasingly widely used in people’s lives. The application of big data in urban computing is multidimensional; it has been involved in different fields, such as urban planning, network optimization, intelligent transportation, energy consumption and so on. Data analysis becomes particularly important for wireless networks. In this paper, a method for analyzing cellular traffic data was proposed. Firstly, a method to extract trend components, periodic components and essential components from complex traffic time series was proposed. Secondly, we introduced causality data mining. Different from traditional time series causality analysis, the depth of causal mining was increased. We conducted causality verification on different components of time series and the results showed that the causal relationship between base stations is different in trend component, periodic component and essential component in urban wireless network. This is crucial for urban planning and network management. Thirdly, DIC-ST: a spatial temporal time series prediction based on decomposition and integration system with causal structure learning was proposed by combining GCN. Final results showed that the proposed method significantly improves the accuracy of cellular traffic prediction. At the same time, this method can play a crucial role for urban computing in network management, intelligent transportation, base station siting and energy consumption when combined with remote sensing map information.
Monitoring Respiratory Motion during VMAT Treatment Delivery Using Ultra-Wideband Radar
Authors: Fallatah Anwar , Bolic Miodrag , MacPherson Miller , La Russa Daniel J.
Published: March 2022

The goal of this paper is to evaluate the potential of a low-cost, ultra-wideband radar system for detecting and monitoring respiratory motion during radiation therapy treatment delivery. Radar signals from breathing motion patterns simulated using a respiratory motion phantom were captured during volumetric modulated arc therapy (VMAT) delivery. Gantry motion causes strong interference affecting the quality of the extracted respiration motion signal. We developed an artificial neural network (ANN) model for recovering the breathing motion patterns. Next, automated classification into four classes of breathing amplitudes is performed, including no breathing, breath hold, free breathing and deep inspiration. Breathing motion patterns extracted from the radar signal are in excellent agreement with the reference data recorded by the respiratory motion phantom. The classification accuracy of simulated deep inspiration breath hold breathing was 94% under the worst case interference from gantry motion and linac operation. Ultra-wideband radar systems can achieve accurate breathing rate estimation in real-time during dynamic radiation delivery. This technology serves as a viable alternative to motion detection and respiratory gating systems based on surface detection, and is well-suited to dynamic radiation treatment techniques. Novelties of this work include detection of the breathing signal using radar during strong interference from simultaneous gantry motion, and using ANN to perform adaptive signal processing to recover breathing signal from large interference signals in real time.
Parallel Optimisation and Implementation of a Real-Time Back Projection (BP) Algorithm for SAR Based on FPGA
Authors: Cao Yue , Guo Shuchen , Jiang Shuai , Zhou Xuan , Wang Xiaobei , Luo Yunhua , Yu Zhongjun , Zhang Zhimin , Deng Yunkai
Published: March 2022

This study conducts an in-depth evaluation of imaging algorithms and software and hardware architectures to meet the capability requirements of real-time image acquisition systems, such as spaceborne and airborne synthetic aperture radar (SAR) systems. By analysing the principles and models of SAR imaging, this research creatively puts forward the fully parallel processing architecture for the back projection (BP) algorithm based on Field-Programmable Gate Array (FPGA). The processing time consumption has significant advantages compared with existing methods. This article describes the BP imaging algorithm, which stands out with its high processing accuracy and two-dimensional decoupling of distance and azimuth, and analyses the algorithmic flow, operation, and storage requirements. The algorithm is divided into five core operations: range pulse compression, upsampling, oblique distance calculation, data reading, and phase accumulation. The architecture and optimisation of the algorithm are presented, and the optimisation methods are described in detail from the perspective of algorithm flow, fixed-point operation, parallel processing, and distributed storage. Next, the maximum resource utilisation rate of the hardware platform in this study is found to be more than 80%, the system power consumption is 21.073 W, and the processing time efficiency is better than designs with other FPGA, DSP, GPU, and CPU. Finally, the correctness of the processing results is verified using actual data. The experimental results showed that 1.1 s were required to generate an image with a size of 900 × 900 pixels at a 200 MHz clock rate. This technology can solve the multi-mode, multi-resolution, and multi-geometry signal processing problems in an integrated manner, thus laying a foundation for the development of a new, high-performance, SAR system for real-time imaging processing.
Determination of Turning Radius and Lateral Acceleration of Vehicle by GNSS/INS Sensor
Authors: Jagelčák Juraj , Gnap Jozef , Kuba Ondrej , Frnda Jaroslav , Kostrzewski Mariusz
Published: March 2022

In this article, we address the determination of turning radius and lateral acceleration acting on a vehicle up to 3.5 t gross vehicle mass (GVM) and cargo in curves based on turning radius and speed. Global Navigation Satellite System with Inertial Navigation System (GNSS/INS) dual-antenna sensor is used to measure acceleration, speed, and vehicle position to determine the turning radius and determine the proper formula to calculate long average lateral acceleration acting on vehicle and cargo. The two methods for automatic selection of events were applied based on stable lateral acceleration value and on mean square error (MSE) of turning radiuses. The models of calculation of turning radius are valid for turning radius within 5–70 m for both methods of automatic selection of events with mean root mean square error (RMSE) 1.88 m and 1.32 m. The models of calculation of lateral acceleration are valid with mean RMSE of 0.022 g and 0.016 g for both methods of automatic selection of events. The results of the paper may be applied in the planning and implementation of packing and cargo securing procedures to calculate average lateral acceleration acting on vehicle and cargo based on turning radius and speed for vehicles up to 3.5 t GVM. The results can potentially be applied for the deployment of autonomous vehicles in solutions grouped under the term of Logistics 4.0.
Reliability of IMU-Derived Temporal Gait Parameters in Neurological Diseases
Authors: Hansen Clint , Ortlieb Christian , Romijnders Robbin , Warmerdam Elke , Welzel Julius , Geritz Johanna , Maetzler Walter
Published: March 2022

Evaluating gait is part of every neurological movement disorder assessment. Generally, the physician assesses the patient based on their experience, but nowadays inertial measurement units (IMUs) are also often integrated in the assessment. Instrumented gait analysis has a longstanding tradition and temporal parameters are used to compare patient groups or trace disease progression over time. However, the day-to-day variability needs to be considered especially in specific patient cohorts. The aim of the study was to examine day-to-day variability of temporal gait parameters of two experimental conditions in a cohort of neurogeriatric patients using data extracted from a lower back-worn IMU. We recruited 49 participants (24 women (age: 78 years ± 6 years, BMI = 25.1 kg/m2 and 25 men (age: 77 years ± 6 years, BMI = 26.5 kg/m2)) from the neurogeriatric ward. Two gait distances (4 m and 20 m) were performed during the first session and repeated the following day. To evaluate reliability, the Intraclass Correlation Coefficient (ICC2,k) and minimal detectable change (MDC) were calculated for the number of steps, step time, stride time, stance time, swing time, double limb support time, double limb support time variability, stride time variability and stride time asymmetry. The temporal gait parameters showed poor to moderate reliability with mean ICC and mean MDC95% values of 0.57 ± 0.18 and 52% ± 53%, respectively. Overall, only four out of the nine computed temporal gait parameters showed high relative reliability and good absolute reliability values. The reliability increased with walking distance. When only investigating steady-state walking during the 20 m walking condition, the relative and absolute reliability improved again. The most reliable parameters were swing time, stride time, step time and stance time. Study results demonstrate that reliability is an important factor to consider when working with IMU derived gait parameters in specific patient cohorts. This advocates for a careful parameter selection as not all parameters seem to be suitable when assessing gait in neurogeriatric patients.
A Low Temperature Coefficient Time-to-Digital Converter with 1.3 ps Resolution Implemented in a 28 nm FPGA
Authors: Mao Xiangyu , Yang Fei , Wei Fang , Shi Jiawen , Cai Jian , Cai Haiwen
Published: March 2022

Time-to-digital converter (TDC) is the key technology to realize accurate time delay measurement in high-precision optical fiber time-frequency transmission and synchronization, optical sensing and many scientific applications. The performance of FPGA-TDC based on the carry chain is sensitive to the operating temperature. This paper presents a parallel multichain cross segmentation method, without multitime measurements, which merges multichain into an equivalent chain, achieving low temperature coefficient and maintaining high precision. The equivalent chain breaks the limit of the intrinsic cell delay of a single carry chain, improves the precision and reduces the impact of temperature variation significantly. A two-channel TDC based on parallel multichain cross segmentation method is implemented in a 28 nm fabrication process Kintex-7 FPGA. The results show that the performance of TDC is improved with the increase of the number of chains. The 10-chain TDC with 1.3 ps resolution, 4.6 ps single-shot precision performs much better than the plain TDC with 11.4 ps resolution, 8.7 ps single-shot precision. The resolution is stable with 0.0002 ps/°C temperature coefficient under an operating temperature range from 25 °C to 70 °C. Moreover, the proposed method reduces the complexity of the circuit and the resource usage.
Prospects for the Use of Echinochloa frumentacea for Phytoremediation of Soils with Multielement Anomalies
Authors: Gorelova Svetlana V. , Muratova Anna Yu. , Zinicovscaia Inga , Okina Olga I. , Kolbas Aliaksandr
Published: March 2022

In a model experiment, some adaptive characteristics, the bioaccumulation of toxic elements from technogenically-contaminated soils with polyelement anomalies, and rhizosphere microflora of Japanese millet, Echinochloa frumentacea, were studied using biochemical, microbiological, physicochemical (AAS, ICP-MS, INAA), and metagenomic (16S rRNA) methods of analysis. Good adaptive characteristics (the content of photosynthetic pigments, low molecular weight antioxidants) of E. frumentacea grown on the soils of metallurgical enterprises were revealed. The toxic effect of soils with strong polyelement anomalies (multiple excesses of MPC for Cr, Ni, Zn, As, petroleum products) on biometric parameters and adaptive characteristics of Japanese millet were shown. The rhizosphere populations of E. frumentacea grown in the background soil were characterized by the lowest taxonomic diversity compared to the rhizobiomes of plants grown in contaminated urban soils. The minimal number of all groups of microorganisms studied was noted in the soils, which contain the highest concentrations of both inorganic (heavy metals) and organic (oil products) pollutants. The taxonomic structure of the rhizospheric microbiomes of E. frumentacea was characterized. It has been established that E. frumentacea accumulated Mn, Co, As, and Cd from soils with polyelement pollution within the average values. V was accumulated mainly in the root system (transfer factor from roots to shoots 0.01–0.05) and its absorption mechanism is rhizofiltration. The removal of Zn by shoots of E. frumentacea increased on soils where the content of the element exceeded the MPC and was 100–454 mg/kg of dry weight (168–508 g/ha). Analysis of the obtained data makes it possible to recommend E. frumentacea for phytoremediation of soil from Cu and Zn at a low level of soil polyelement contamination using grass mixtures.
The Case of South Korean Airlines-Within-Airlines Model: Helping Full-Service Carriers Challenge Low-Cost Carriers
Authors: Khan Nokhaiz Tariq , Aslam Javed , Rauf Ateeq Abdul , Kim Yun Bae
Published: March 2022

The South Korean aviation market has grown rapidly since the emergence of Low-Cost Carriers (LCCs), and in response to this emergence, the two Full-Service Carriers (FSCs) of South Korea adopted the airline-within-airline (AWA) model and introduced their LCCs to compete with independent LCCs (ILCCs). A few years back, ILCCs filed a petition against Asiana Airlines, one of the two FSCs in South Korea, as Asiana Air was launching another subsidiary on the model of AWA. This, interestingly, indicates that AWA are doing well in the South Korean aviation market. However, a detailed study is required to evaluate the performance of this model, as in the global market the success of AWA is blurred. This study attempts to shed light on the performance of South Korean AWA, which may provide fruitful insights considering the post-COVID-19 dynamics of the aviation market.
Assessment of Concept between Rural Development Challenges and Local Food Systems: A Combination between Multi-Criteria Decision Analysis and Econometric Modelling Approach
Authors: Prišenk Jernej , Turk Jernej
Published: March 2022

This study investigates the influence of social, economic, and environmental impacts on the promotion and marketing systems of local food products from mountain areas in Slovenia. These impacts were assessed using an econometric modelling approach. Two econometric models were developed (one for production and one for marketing). The case studies of local food products were selected from Slovenian mountain regions, most of which were from less-favored areas (LFAs). A majority of the selected food commodities were of high quality, with or without protected designations. Data collection was carried out via interviews. Due to production limitation on mountain areas in Slovenia and other constraints in LFAs, the socio-economic and environmental impacts on success of production and marketing systems need to be clarified. These relations present a potential impact on the wider socio-economic development in the region. The empirical results, obtained using an econometric modelling approach, clearly show the importance of encouraging the socio-economic and environmental impacts in ensuring the marketing and production potentials of local food products. The result express good relationships, and cooperation between the actors in the food supply chains contributing to a successful marketing system and production system of local food products (small, average, large) is dependent on the available local labour in mountain rural areas.
Stakeholders’ Preferences towards Contract Attributes: Evidence from Rice Production in Vietnam
Authors: Tuyen Mai Chiem , Sirisupluxana Prapinwadee , Bunyasiri Isriya , Hung Pham Xuan
Published: March 2022

Contract farming is typically considered an appropriate measure for small-scale farmers to solve their constraints and problems. However, despite positive effects, low participation in and high dropout rates from contract farming schemes remain challenges. Therefore, this study objects to evaluate preferences for contract attributes and attribute levels among contracting buyers, farmers, and government officials through data triangulation from key informant interviews, focus group discussions, and participant observations. Based on Henry Garrett Ranking, Rank Based Quotient, and Rank Based Sum methods, results indicate that the most important attributes were price options, payment, delivery arrangement, input provision, input-use requirements, and product quality standards. Despite a consensus on the ranking of the contract attributes, the preferences for the attribute levels among the stakeholders were heterogeneous. It is recommended that attributes and their levels should be pertinent in contract agreements. Thus, contract design with an adjusted or premium price, 50% of estimated payment before harvesting and the rest after delivery three to five days or lump-sum immediate payment, delivery after harvesting, inputs provision by the contractors through the representative branches or stores located at the local areas or cooperatives, banning active-ingredients or flexible use of inputs from the contractors to produce Good Agricultural Practices or organic products are considerable options.