bluuebunny/crossref_metadata_2025 huggingface dataset:
Cover Crop Contributions to Improve the Soil Nitrogen and Carbon Sequestration in Almond Orchards (SW Spain)
Authors: Repullo-Ruibérriz de Torres Miguel A. , Moreno-García Manuel , Ordóñez-Fernández Rafaela , Rodríguez-Lizana Antonio , Cárceles Rodríguez Belén , García-Tejero Iván Francisco , Durán Zuazo Víctor Hugo , Carbonell-Bojollo Rosa M.
Published: February 2021

Almond (Prunus dulcis Mill. [D.A. Webb]) is the third most widely spread crop in Spain and has traditionally been cultivated in marginal areas and shallow soils under rainfed conditions. However, it recently has been progressively introduced in flat irrigated areas. The implementation of cover crops in the inter-rows of woody crops has been proven as a suitable strategy to reduce the runoff and soil erosion but they also can boost soil quality and health. A field experiment was conducted during two-monitoring seasons to examine the soil nitrogen and carbon sequestration potential of three seeded cover crops [barley (Hordeum vulgare L.), hairy vetch (Vicia villosa Roth), and a mixture of 65% barley and 35% vetch] and a control of spontaneous flora in irrigated almond orchards (SW Spain). Here, we show that barley provided the highest biomass amount, followed by mixture covers, vetch, and the control treatment. Also, vetch covered the soil faster in the growing stage, but its residues were decomposed easier than barley and mixture treatments during the decomposition period after mowing, providing less soil protection when the risk of water erosion with autumn rainfall is high. On the other hand, vetch improved soil nitrate content by over 35% with respect to barley and mixture treatments at 0–20 cm soil depth throughout the studied period. In addition, a greater carbon input to the soil was determined in the barley plot. That is, the mixture and barley cover crops had higher potential for carbon sequestration, augmenting the soil organic carbon by more than 1.0 Mg ha−1 during the study period. Thus, taking into consideration the findings of the present experiment, the establishment of a seeded cover crop would be more advisable than spontaneous flora to mitigate soil erosion, enhancing soil fertility and carbon sequestration in irrigated almond plantations in Mediterranean semi-arid regions.
Species Interactions and Nitrogen Use during Early Intercropping of Intermediate Wheatgrass with a White Clover Service Crop
Authors: Li Shoujiao , Jensen Erik Steen , Liu Nan , Zhang Yingjun , Dimitrova Mårtensson Linda-Maria
Published: February 2021

Perennial grain crops intercropped with legumes are expected to use nitrogen (N) resources efficiently. A pot experiment using the 15N isotope dilution method demonstrated interspecific competition and use of N from the soil and N2 fixation in intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, IWG) and white clover (Trifolium repens L., WC) intercrops at five species-relative frequencies and four levels of inorganic N fertilizer in a replacement series design. The proportion of N in WC derived from the atmosphere increased from 39.7% in a sole crop to 70.9% when intercropped with IWG, and 10.1% N in IWG transferred from WC. Intermediate wheatgrass showed high fitness with maintained high total dry matter production at low relative frequencies. Decreasing IWG-relative frequency only increased dry matter and N accumulation of WC, resulting in increased amounts of N2 fixed. Increased levels of N fertilization increased the proportion of N acquired from the fertilizer in IWG and WC but decreased the N fixed by WC and N absorbed by IWG from the soil. Our study indicates that WC supply sufficient fixed N2 for IWG intercrop biomass yields under appropriate levels of soil N fertility and species-relative frequencies.
Variation among Tanzania Rice Germplasm Collections Based on Agronomic Traits and Resistance to Rice Yellow Mottle Virus
Authors: Suvi William Titus , Shimelis Hussein , Laing Mark , Mathew Isack , Shayanowako Admire I. T.
Published: February 2021

Rice (Oryza species) is a commercial crop worldwide. Across Africa, the potential yield and quality of rice is diminished by a lack of high performance, locally adapted varieties, and the impact of rice yellow mottle virus (RYMV). The objective of this study was to assess the performance of a diverse collection of rice germplasm for RYMV resistance and agronomic traits, and to select promising lines for breeding for Tanzanian conditions. Fifty-four rice genotypes were field evaluated in two important rice production sites (Ifakara and Mkindo) in Tanzania, which are recognized as RYMV hotspots, using a 6 × 9 alpha lattice design with two replications. There was significant (p < 0.05) genotypic variation for agronomic traits and RYMV susceptibility in the tested germplasm. Seven genotypes with moderate to high RYMV resistance were identified, including Salama M-57, SSD1, IRAT 256, Salama M-55, Mwangaza, Lunyuki, and Salama M-19, which were identified as new sources of resistance genes. Positive and significant correlations were detected between grain yield and number of panicles per plant (NPP), panicle length (PL), number of grains per panicle (NGP), percentage-filled grains (PFG), and thousand-grain weight (TGW), which are useful traits for simultaneous selection for rice yield improvement. A principal component analysis allocated five principal components, accounting for 79.88% of the total variation present in the assessed germplasm collection. Traits that contributed most to variability included NPP, number of tillers/plant (NT), PL, grain yield (GY), and days to 50% flowering (DFL). The genotypes Rangimbili, Gigante, and SARO possess complementary agronomic traits and RYMV resistance, and can be recommended for further evaluation, genetic analysis, and breeding.
Baicalein Inhibits Streptococcus mutans Biofilms and Dental Caries-Related Virulence Phenotypes
Authors: Vijayakumar Aparna , Sarveswari Hema Bhagavathi , Vasudevan Sahana , Shanmugam Karthi , Solomon Adline Princy , Neelakantan Prasanna
Published: February 2021

Dental caries, the most common oral disease, is a major public healthcare burden and affects more than three billion people worldwide. The contemporary understanding of the need for a healthy microbiome and the emergence of antimicrobial resistance has resulted in an urgent need to identify compounds that curb the virulence of pathobionts without microbial killing. Through this study, we have demonstrated for the first time that 5,6,7-trihydroxyflavone (Baicalein) significantly downregulates crucial caries-related virulence phenotypes in Streptococcus mutans. Baicalein significantly inhibited biofilm formation by Streptococcus mutans UA159 (MBIC50 = 200 μM), without significant growth inhibition. Notably, these concentrations of baicalein did not affect the commensal S. gordonii. Strikingly, baicalein significantly reduced cell surface hydrophobicity, autoaggregation and acid production by S. mutans. Mechanistic studies (qRT-PCR) showed downregulation of various genes regulating biofilm formation, surface attachment, quorum sensing, acid production and competence. Finally, we demonstrate the potential translational value of baicalein by reporting synergistic interaction with fluoride against S. mutans biofilms.
Frataxins Emerge as New Players of the Intracellular Antioxidant Machinery
Authors: Uceda Ana Belén , Donoso Josefa , Frau Juan , Vilanova Bartolomé , Adrover Miquel
Published: February 2021

Frataxin is a mitochondrial protein which deficiency causes Friedreich’s ataxia, a cardio-neurodegenerative disease. The lack of frataxin induces the dysregulation of mitochondrial iron homeostasis and oxidative stress, which finally causes the neuronal death. The mechanism through which frataxin regulates the oxidative stress balance is rather complex and poorly understood. While the absence of human (Hfra) and yeast (Yfh1) frataxins turn out cells sensitive to oxidative stress, this does not occur when the frataxin gene is knocked-out in E. coli. To better understand the biological roles of Hfra and Yfh1 as endogenous antioxidants, we have studied their ability to inhibit the formation of reactive oxygen species (ROS) from Cu2+- and Fe3+-catalyzed degradation of ascorbic acid. Both proteins drastically reduce the formation of ROS, and during this process they are not oxidized. In addition, we have also demonstrated that merely the presence of Yfh1 or Hfra is enough to protect a highly oxidation-prone protein such as α-synuclein. This unspecific intervention (without a direct binding) suggests that frataxins could act as a shield to prevent the oxidation of a broad set of intracellular proteins, and reinforces that idea that frataxin can be used to prevent neurological pathologies linked to an enhanced oxidative stress.
xCT-Driven Expression of GPX4 Determines Sensitivity of Breast Cancer Cells to Ferroptosis Inducers
Authors: Lee Namgyu , Carlisle Anne E. , Peppers Austin , Park Sung Jin , Doshi Mihir B. , Spears Meghan E. , Kim Dohoon
Published: February 2021

Inducers of ferroptosis such as the glutathione depleting agent Erastin and the GPX4 inhibitor Rsl-3 are being actively explored as potential therapeutics in various cancers, but the factors that determine their sensitivity are poorly understood. Here, we show that expression levels of both subunits of the cystine/glutamate antiporter xCT determine the expression of GPX4 in breast cancer, and that upregulation of the xCT/selenocysteine biosynthesis/GPX4 production axis paradoxically renders the cancer cells more sensitive to certain types of ferroptotic stimuli. We find that GPX4 is strongly upregulated in a subset of breast cancer tissues compared to matched normal samples, and that this is tightly correlated with the increased expression of the xCT subunits SLC7A11 and SLC3A2. Erastin depletes levels of the antioxidant selenoproteins GPX4 and GPX1 in breast cancer cells by inhibiting xCT-dependent extracellular reduction which is required for selenium uptake and selenocysteine biosynthesis. Unexpectedly, while breast cancer cells are resistant compared to nontransformed cells against oxidative stress inducing drugs, at the same time they are hypersensitive to lipid peroxidation and ferroptosis induced by Erastin or Rsl-3, indicating that they are ‘addicted’ to the xCT/GPX4 axis. Our findings provide a strategic basis for targeting the anti-ferroptotic machinery of breast cancer cells depending on their xCT status, which can be further explored.
Recent Progress in Discovering the Role of Carotenoids and Metabolites in Prostatic Physiology and Pathology—A Review—Part II: Carotenoids in the Human Studies
Authors: Dulińska-Litewka Joanna , Hałubiec Przemysław , Łazarczyk Agnieszka , Szafrański Oskar , Sharoni Yoav , McCubrey James A. , Gąsiorkiewicz Bartosz , Bohn Torsten
Published: February 2021

Among the vast variety of plant-derived phytochemicals, the group of carotenoids has continuously been investigated in order to optimize their potential application in the area of dietary intervention related to chronic diseases. One organ that has been especially targeted in many of these studies and clinical trials is the human prostate. Without doubt, carotenoids (and their endogenous derivatives—retinoids and apo-carotenoids) are involved in a plethora of intra- and intercellular signaling, cell growth, and differentiation of prostate tissue. Due to the accumulation of new data on the role of different carotenoids, such as lycopene (LYC) and β-carotene (BC), in prostatic physiology and pathology, the present review aimed to cover the past ten years of research in this regard. Data from experimental studies are presented in the first part of the review, while epidemiological studies are disclosed in this second part. The objective of this compilation was to emphasize the present state of knowledge about the most potent molecular targets of carotenoids, as well as to propose promising carotenoid agents for the prevention and possible treatment of prostatic diseases.
Determination of the Antioxidant Activity of Samples of Tea and Commercial Sources of Vitamin C, Using an Enzymatic Biosensor
Authors: Ribeiro Danilo Braga , Santos Silva Gabriela , dos Santos Djanira Rubim , Castro Costa Andressa Rose , Braga Ribeiro Eliane , Badea Mihaela , Nunes Gilvanda Silva
Published: February 2021

Antioxidants are synthetic or natural compounds capable of preventing or delaying oxidative damage caused by chemical species that can oxidize cell biomolecules, such as proteins, membranes, and DNA, leading to the development of various pathologies, such as cancer, atherosclerosis, Parkinson, Alzheimer, and other diseases serious. In this study, an amperometric biosensor was used to determine the antioxidant activity of teas and effervescent products based on vitamin C, available on the market. A sensor composed of three electrodes was used. The performance of the following electrochemical mediators was evaluated: meldola blue combined with Reineck salt (MBRS), Prussian blue (PB), and cobalt phthalocyanine (CoPC), as well as the time of polymerization in the enzymatic immobilization process and the agitation process during chronoamperometric measurements. Prussian blue proved to be more efficient as a mediator for the desired purposes. After optimizing the construction stages of the biosensor, as well as the operational parameters, it presented stability for a period of 7 months. The results clearly indicate that the biosensor can be successfully used to detect fraud in products called “antioxidants” or even in drugs containing less ascorbic acid than indicated on the labels. The detection limit was set at 4.93 µmol·L−1.
A Cascaded Ensemble of Sparse-and-Dense Dictionaries for Vehicle Detection
Authors: Rong Zihao , Wang Shaofan , Kong Dehui , Yin Baocai
Published: February 2021

Vehicle detection as a special case of object detection has practical meaning but faces challenges, such as the difficulty of detecting vehicles of various orientations, the serious influence from occlusion, the clutter of background, etc. In addition, existing effective approaches, like deep-learning-based ones, demand a large amount of training time and data, which causes trouble for their application. In this work, we propose a dictionary-learning-based vehicle detection approach which explicitly addresses these problems. Specifically, an ensemble of sparse-and-dense dictionaries (ESDD) are learned through supervised low-rank decomposition; each pair of sparse-and-dense dictionaries (SDD) in the ensemble is trained to represent either a subcategory of vehicle (corresponding to certain orientation range or occlusion level) or a subcategory of background (corresponding to a cluster of background patterns) and only gives good reconstructions to samples of the corresponding subcategory, making the ESDD capable of classifying vehicles from background even though they exhibit various appearances. We further organize ESDD into a two-level cascade (CESDD) to perform coarse-to-fine two-stage classification for better performance and computation reduction. The CESDD is then coupled with a downstream AdaBoost process to generate robust classifications. The proposed CESDD model is used as a window classifier in a sliding-window scan process over image pyramids to produce multi-scale detections, and an adapted mean-shift-like non-maximum suppression process is adopted to remove duplicate detections. Our CESDD vehicle detection approach is evaluated on KITTI dataset and compared with other strong counterparts; the experimental results exhibit the effectiveness of CESDD-based classification and detection, and the training of CESDD only demands small amount of time and data.
Designing Trojan Detectors in Neural Networks Using Interactive Simulations
Authors: Bajcsy Peter , Schaub Nicholas J. , Majurski Michael
Published: February 2021

This paper addresses the problem of designing trojan detectors in neural networks (NNs) using interactive simulations. Trojans in NNs are defined as triggers in inputs that cause misclassification of such inputs into a class (or classes) unintended by the design of a NN-based model. The goal of our work is to understand encodings of a variety of trojan types in fully connected layers of neural networks. Our approach is: (1) to simulate nine types of trojan embeddings into dot patterns; (2) to devise measurements of NN states; and (3) to design trojan detectors in NN-based classification models. The interactive simulations are built on top of TensorFlow Playground with in-memory storage of data and NN coefficients. The simulations provide analytical, visualization, and output operations performed on training datasets and NN architectures. The measurements of a NN include: (a) model inefficiency using modified Kullback–Liebler (KL) divergence from uniformly distributed states; and (b) model sensitivity to variables related to data and NNs. Using the KL divergence measurements at each NN layer and per each predicted class label, a trojan detector is devised to discriminate NN models with or without trojans. To document robustness of such a trojan detector with respect to NN architectures, dataset perturbations, and trojan types, several properties of the KL divergence measurement are presented.
Computation of Effective Elastic Properties Using a Three-Dimensional Semi-Analytical Approach for Transversely Isotropic Nanocomposites
Authors: Tapia Monica , Espinosa-Almeyda Y. , Rodríguez-Ramos R. , Otero José A.
Published: February 2021

A three-dimensional semi-analytical finite element method (SAFEM-3D) is implemented in this work to calculate the effective properties of periodic elastic-reinforced nanocomposites. Different inclusions are also considered, such as discs, ellipsoidals, spheres, carbon nanotubes (CNT) and carbon nanowires (CNW). The nanocomposites are assumed to have isotropic or transversely isotropic inclusions embedded in an isotropic matrix. The SAFEM-3D approach is developed by combining the two-scale asymptotic homogenization method (AHM) and the finite element method (FEM). Statements regarding the homogenized local problems on the periodic cell and analytical expressions of the effective elastic coefficients are provided. Homogenized local problems are transformed into boundary problems over one-eighth of the cell. The FEM is implemented based on the principle of the minimum potential energy. The three-dimensional region (periodic cell) is divided into a finite number of 10-node tetrahedral elements. In addition, the effect of the inclusion’s geometrical shape, volume fraction and length on the effective elastic properties of the composite with aligned or random distributions is studied. Numerical computations are developed and comparisons with other theoretical results are reported. A comparison with experimental values for CNW nanocomposites is also provided, and good agreement is obtained.
Assessment of a Spalart–Allmaras Model Coupled with Local Correlation Based Transition Approaches for Wind Turbine Airfoils
Authors: D’Alessandro Valerio , Montelpare Sergio , Ricci Renato
Published: February 2021

This paper present recent advances in the development of local correlation based laminar–to–turbulent transition modeling relying on the Spalart–Allmaras equation. Such models are extremely important for the flow regimes involved in wind energy applications. Indeed, fully turbulent flow models are not completely reliable to predict the aerodynamic force coefficients. This is particularly significant for the wind turbine blade sections. In this paper, we focus our attention on two different transitional flow models for Reynolds–Averaged Navier–Stokes (RANS) equations. It is worth noting that this is a crucial aspect because standard RANS models assume a fully turbulent regime. Thus, our approaches couple the well–known γ– technique and logγ equation with the Spalart–Allmaras turbulence model in order to overcome the common drawbacks of standard techniques. The effectiveness, efficiency, and robustness of the above-mentioned methods are tested and discussed by computing several flow fields developing around airfoils operating at Reynolds numbers typical of wind turbine blade sections.
Radiomic and Artificial Intelligence Analysis with Textural Metrics, Morphological and Dynamic Perfusion Features Extracted by Dynamic Contrast-Enhanced Magnetic Resonance Imaging in the Classification of Breast Lesions
Authors: Fusco Roberta , Piccirillo Adele , Sansone Mario , Granata Vincenza , Vallone Paolo , Barretta Maria Luisa , Petrosino Teresa , Siani Claudio , Di Giacomo Raimondo , Di Bonito Maurizio , Botti Gerardo , Petrillo Antonella
Published: February 2021

Purpose: The aim of the study was to estimate the diagnostic accuracy of textural, morphological and dynamic features, extracted by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) images, by carrying out univariate and multivariate statistical analyses including artificial intelligence approaches. Methods: In total, 85 patients with known breast lesion were enrolled in this retrospective study according to regulations issued by the local Institutional Review Board. All patients underwent DCE-MRI examination. The reference standard was pathology from a surgical specimen for malignant lesions and pathology from a surgical specimen or fine needle aspiration cytology, core or Tru-Cut needle biopsy for benign lesions. In total, 91 samples of 85 patients were analyzed. Furthermore, 48 textural metrics, 15 morphological and 81 dynamic parameters were extracted by manually segmenting regions of interest. Statistical analyses including univariate and multivariate approaches were performed: non-parametric Wilcoxon–Mann–Whitney test; receiver operating characteristic (ROC), linear classifier (LDA), decision tree (DT), k-nearest neighbors (KNN), and support vector machine (SVM) were utilized. A balancing approach and feature selection methods were used. Results: The univariate analysis showed low accuracy and area under the curve (AUC) for all considered features. Instead, in the multivariate textural analysis, the best performance (accuracy (ACC) = 0.78; AUC = 0.78) was reached with all 48 metrics and an LDA trained with balanced data. The best performance (ACC = 0.75; AUC = 0.80) using morphological features was reached with an SVM trained with 10-fold cross-variation (CV) and balanced data (with adaptive synthetic (ADASYN) function) and a subset of five robust morphological features (circularity, rectangularity, sphericity, gleaning and surface). The best performance (ACC = 0.82; AUC = 0.83) using dynamic features was reached with a trained SVM and balanced data (with ADASYN function). Conclusion: Multivariate analyses using pattern recognition approaches, including all morphological, textural and dynamic features, optimized by adaptive synthetic sampling and feature selection operations obtained the best results and showed the best performance in the discrimination of benign and malignant lesions.
Establishment of a Rolling-Sliding Test Bench to Analyze Abrasive Wear Propagation of Different Bearing Materials for Knee Implants
Authors: Hembus Jessica , Ambellan Felix , Zachow Stefan , Bader Rainer
Published: February 2021

Currently, new materials for knee implants need to be extensively tested but such tests are expensive in a knee wear simulator in a realized design. However, using a rolling-sliding test bench, these materials can be examined under the same test conditions, but with simplified geometries. In the present study, the test bench was optimized, and forces were adapted to the physiological contact pressure in the knee joint using the available geometric parameters. Various polymers made of polyethylene and polyurethane, articulating against test wheels made of cobalt-chromium and aluminum titanate, were tested in the test bench using adapted forces based on ISO 14243–1. Polyurethane materials showed distinctly higher wear rates than polyethylene materials and showed inadequate wear resistance for use as knee implant material. Thus, the rolling-sliding test bench is an adaptable test setup to evaluate newly developed bearing materials for knee implants. It combines the advantages of screening and simulator tests and allows for the testing of various bearing materials under physiological load and tribological conditions of the human knee joint. The wear behavior of different material compositions and the influence of surface geometry and quality can be initially investigated without the need to produce complex implant prototypes of total knee endoprosthesis or interpositional spacers.
Simulation of Groundwater Flow in Fractured-Karst Aquifer with a Coupled Model in Maling Reservoir, China
Authors: Cai Jinbang , Su Yue , Shen Huan , Huang Yong
Published: February 2021

A coupled model has been developed to simulate groundwater flow in fractured karst systems according to the complex geological and karst hydrogeological conditions of the dam site, where a 3D mathematical model based on Boussinesq equation was used to describe the movement of groundwater flow in fractured medium, and a 1D conduit model for karst medium. The model was solved with the continuous hydraulic heads at the common boundaries. The hydraulic conductivities of karst medium were determined by geometrical parameters and flux of pipes. Furthermore, the permeability parameters for fractured medium were calibrated by the measured and calculated groundwater levels. The calibrated model was employed to predict the variation of groundwater flow field and leakage from the karst pipes and underground powerhouse during the reservoir operation. The simulated results showed that the groundwater level of the powerhouse had decreased by about 2–5 m. The water level of conveyance pipeline had risen by 10–20 m, and the water level on both banks had risen by 15–25 m. The leakage of karst conduits for impervious failure was larger than that for normal seepage control. In addition, the leakage of the powerhouse was estimated to be about 1000–3000 m3/d, and the seepage control of karst pipes had little influence on the leakage of underground powerhouse.
Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge
Authors: Micek Agnieszka , Jóźwiakowski Krzysztof , Marzec Michał , Listosz Agnieszka , Grabowski Tadeusz
Published: February 2021

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.
Critical View on Buffer Layer Formation and Monolayer Graphene Properties in High-Temperature Sublimation
Authors: Stanishev Vallery , Armakavicius Nerijus , Bouhafs Chamseddine , Coletti Camilla , Kühne Philipp , Ivanov Ivan G. , Zakharov Alexei A. , Yakimova Rositsa , Darakchieva Vanya
Published: February 2021

In this work we have critically reviewed the processes in high-temperature sublimation growth of graphene in Ar atmosphere using closed graphite crucible. Special focus is put on buffer layer formation and free charge carrier properties of monolayer graphene and quasi-freestanding monolayer graphene on 4H–SiC. We show that by introducing Ar at higher temperatures, TAr, one can shift the formation of the buffer layer to higher temperatures for both n-type and semi-insulating substrates. A scenario explaining the observed suppressed formation of buffer layer at higher TAr is proposed and discussed. Increased TAr is also shown to reduce the sp3 hybridization content and defect densities in the buffer layer on n-type conductive substrates. Growth on semi-insulating substrates results in ordered buffer layer with significantly improved structural properties, for which TAr plays only a minor role. The free charge density and mobility parameters of monolayer graphene and quasi-freestanding monolayer graphene with different TAr and different environmental treatment conditions are determined by contactless terahertz optical Hall effect. An efficient annealing of donors on and near the SiC surface is suggested to take place for intrinsic monolayer graphene grown at 2000 ∘C, and which is found to be independent of TAr. Higher TAr leads to higher free charge carrier mobility parameters in both intrinsically n-type and ambient p-type doped monolayer graphene. TAr is also found to have a profound effect on the free hole parameters of quasi-freestanding monolayer graphene. These findings are discussed in view of interface and buffer layer properties in order to construct a comprehensive picture of high-temperature sublimation growth and provide guidance for growth parameters optimization depending on the targeted graphene application.
Efficacy of Manual Therapy on Facilitatory Nociception and Endogenous Pain Modulation in Older Adults with Knee Osteoarthritis: A Case Series
Authors: Sánchez-Romero Eleuterio A. , González-Zamorano Yeray , Arribas-Romano Alberto , Martínez-Pozas Oliver , Fernández Espinar Elena , Pedersini Paolo , Villafañe Jorge Hugo , Alonso Pérez Jose Luis , Fernández-Carnero Josué
Published: February 2021

Background: manual therapy (MT) has been shown to have positive effects in patients with osteoarthritis (OA)-related pain, and its use in clinical settings is recommended. However, the mechanisms of action for how these positive effects occur are not yet well understood. The aim of the present study was to investigate the influence of MT treatment on facilitatory nociception and endogenous pain modulation in patients with knee OA related pain. Methods: Twenty-eight patients with knee OA were included in this study. Pain intensity using the numerical pain rating scale (NPRS), temporal summation (TS), conditioned pain modulation (CPM), and local (knee) and distant (elbow) hyperalgesia through the pressure pain threshold (PPT), were assessed to evaluate the pain modulatory system. Patients underwent four sessions of MT treatments within 3 weeks and were evaluated at the baseline, after the first session and after the fourth session. Results: the MT treatment reduced knee pain after the first session (p = 0.03) and after the fourth session (p = 0.04). TS decreased significantly after the fourth session of MT (p = 0.02), while a significant increase in the CPM assessment was detected after the fourth session (p = 0.05). No significant changes in the PPT over the knee and elbow were found in the follow-ups. Conclusions: The results from our study suggest that MT might be an effective and safe method for improving pain and for decreasing temporal summation.
Functional Evaluation of a Novel Multi-Axial Alveolar Distractor—Preliminary In Vivo Animal Study
Authors: Wu Cheng-Hsien , Chen Kun-Chun , Lin Yang-Sung , Liu Yuan-Chih , Lin Chun-Li
Published: February 2021

This study evaluates the biomechanical performance of a new multi-axial alveolar distractor using an animal study. The multi-axial alveolar distractor is designed with a ball and socket joint mechanism that can rotate up to 60° toward the buccal/lingual and mesial/distal sides intra-operatively to achieve vector control. The transport segment can be moved through activating the transport screw with 0.25 pitch, allowing 13 mm in distraction height. This distractor was fixed at the right angulus mandibular of experimental rabbits and adjusted 15° toward the mesial side and 25° toward the buccal side as Group TMB (toward mesial-buccal) (n = 3), and 15° toward the mesial side as Group TM (toward mesial) (n = 3). Group TC (control) was the control group. The distractors were activated 1 mm/day for 13 days. Living bone growth was observed at various periods. The total bone growth length at the angulus region and buccal side distraction thickness after distraction were calculated. The variations in bone growth geometric shape at the mandible angulus were also recorded. Fracture testing was performed to understand the variations in the mechanical strength between the distracted and intact bone specimens. The digital radiography results showed that the osteotomy areas at the mandible angulus were healed and the bone growth completed after surgery. The average bone growth length of Group TMB was 17.68 mm. This was greater than that of Group TM at 14.79 mm. The corresponding buccal side distractor thicknesses for Group TMB and TM after distraction were 5.12 ± 0.52 mm and 3.32 ± 0.37 mm, respectively. The tensile strengths of the bone specimens after distraction of Groups TMB, TM and TC were 172.13 N, 119.27 N and 304.24 N, respectively, and the percentage of distraction bone tensile strength to normal bone was 57% and 39% for Groups TMB and TM, respectively. This study concluded that this new multi-axial alveolar bone distractor can drive bones to grow in accordance with the direction/angle of the distraction plan. The bone growth healed gradually and presented insufficient mechanical strength.
High-Resolution Acoustic Cameras Provide Direct and Efficient Assessments of Large Demersal Fish Populations in Extremely Turbid Waters
Authors: Artero Céline , Marchetti Simon , Bauer Eric , Viala Christophe , Noël Claire , Koenig Christopher , Berzins Rachel , Lampert Luis
Published: February 2021

Monitoring fish species populations in very turbid environments is challenging. Acoustic cameras allow work in very poor visibility but are often deployed as a fixed observation point, limiting the scope of the survey. A BlueView P900-130 acoustic camera was deployed in rocky marine habitats off the coast of French Guiana in order to assess the total abundance, size structure and spatial distribution of a demersal fish population. The relevancy of using an acoustic camera to achieve these three objectives was evaluated by comparing acoustic data to those obtained from fishing surveys. The detection and identification of large demersal fish species were possible with the shape and size of the acoustic signal and acoustic shadow silhouette as well as swimming behavior. Mobile surveys combined with stationary surveys increased the probability of distinguishing individuals from inanimate objects. Estimated total length based on the acoustic signal underestimated the actual length of fish measured on deck, but the data showed the same trends in spatial and temporal variation. Acoustic cameras overcame the extreme lack of visibility by increasing knowledge of fish use of habitat, therefore providing much more efficiency in the effort, more accurate data on the abundance, size structure and spatial distribution than the fishing method. Thus, despite few limitations, acoustic camera surveys are far superior to fishing surveys in evaluating large demersal fish stock status.
Sinus Floor Augmentation—Associated Surgical Ciliated Cysts: Case Series and a Systematic Review of the Literature
Authors: Kahn Adrian , Matalon Shlomo , Salem Rahaf Bassam , Kats Lazar , Chaushu Liat , Vered Marilena , Rosen Eyal
Published: February 2021

This study aimed to characterize the demographic and clinical features of underreported surgical ciliated cysts developing after sinus floor augmentation, based on a series of cases from our files and a systematic review of the literature. A series of five cases (four patients) of microscopically confirmed surgical ciliated cysts following sinus floor augmentation procedures from our files are described. A systematic literature search (1991–2020) with strict clinical-, radiological- and microscopic-based exclusion and inclusion criteria was performed to detect additional similar cases. The systematic review revealed only five cases that fulfilled the inclusion criteria. Altogether, surgical ciliated cysts associated with sinus floor augmentation have been rarely reported in the literature, and have not been characterized either demographically or clinically. Graft materials were diverse, implants were placed simultaneously, or up to two years post-augmentation. The associated surgical ciliated cysts developed between 0.5 and 10 years post-augmentation. Although limited in its extent, this study is the first series to characterize possible underreported sequelae of surgical ciliated cysts associated with sinus floor augmentation. It emphasizes the need for long post-operative follow-up and confirmation of lesion by microscopic examination.
Special Issue “Thermochemical Conversion Processes for Solid Fuels and Renewable Energies”
Authors: Alobaid Falah , Ströhle Jochen
Published: February 2021

The world society ratifies international measures to reach a flexible and low-carbon energy economy, attenuating climate change and its devastating environmental consequences. The main contribution of this Special Issue is related to thermochemical conversion technologies of solid fuels (e.g., biomass, refuse-derived fuel, and sewage sludge), in particular via combustion and gasification. Here, the recent activities on operational flexibility of co-combustion of biomass and lignite, carbon capture methods, solar-driven air-conditioning systems, integrated solar combined cycle power plants, and advanced gasification systems, such as the sorption-enhanced gasification and the chemical looping gasification, are shown.
The Duality of Similarity and Metric Spaces
Authors: Rozinek Ondřej , Mareš Jan
Published: February 2021

We introduce a new mathematical basis for similarity space. For the first time, we describe the relationship between distance and similarity from set theory. Then, we derive generally valid relations for the conversion between similarity and a metric and vice versa. We present a general solution for the normalization of a given similarity space or metric space. The derived solutions lead to many already used similarity and distance functions, and combine them into a unified theory. The Jaccard coefficient, Tanimoto coefficient, Steinhaus distance, Ruzicka similarity, Gaussian similarity, edit distance and edit similarity satisfy this relationship, which verifies our fundamental theory.
Service Quality Assessment of App-Based Demand-Responsive Public Transit Services in Lahore, Pakistan
Authors: Abdullah Muhammad , Ali Nazam , Shah Syed Arif Hussain , Javid Muhammad Ashraf , Campisi Tiziana
Published: February 2021

App-based demand-responsive transit (DRT) services are emerging where conventional public transport is unable to meet the demand. SWVL (choice A) and Airlift (choice B) are two such DRT bus services operating in Lahore, Pakistan. It is important for the policy makers and operators to evaluate the satisfaction levels of the passengers using these services. This study evaluated passengers’ satisfaction regarding choice A and choice B through a questionnaire survey. A total of 440 responses were collected from the users of the DRT services through personal interviews and a web-based approach. Factor analysis on the collected data produced two underlying factors, namely service-attributes and bus ambiance. Ordinal regression showed that the service-attributes and ambiance were significant predictors of overall satisfaction levels about choice A. Service-attributes indicated a larger positive impact on overall satisfaction with choice A as compared to ambiance. Although the ordinal model for choice B fitted the data well, the predictors were found to be insignificant. The results offer an insight into which predictors affect the overall satisfaction and how it can be improved.
Reaction of Converter Slag with Supercritical Carbon Dioxide and Its Potential Applicability as Aggregate for Concrete
Authors: Moon Hoon , Kim Kyeongtae , Kim Ji-Hyun , Lee Minhee , Chung Chul-Woo
Published: February 2021

The presence of free lime and periclase in converter slag prevents it from directly being utilized as a source of concrete aggregate due to the deleterious expansion caused by reaction of free lime and periclase. In general, a six-month aging period is suggested in order to avoid any potential problems, but it is a tedious process that requires a long period of time. In this work, supercritical CO2 (SCD) was used to reduce the aging period down to one day or so. Since SCD creates a more aggressive environment for reaction, it can directly attack the surface of free lime and periclase to induce expansive reaction before using converter slag as concrete aggregate. According to the experimental results, the surface of converter slag was successfully carbonated by SCD, showing 7.80% of CO2 uptake by weight of converter slag. It was found that the mortar bar made of reacted converter slag reduced the amount of expansion. The 28-day compressive strength of mortar with converter slag was slightly reduced after reaction with SCD, but it was still 32% higher than mortar made of conventional sand.
Advances in Tissue Engineering for Disc Repair
Authors: Lee Chang Kyu , Heo Dong Hwa , Chung Hungtae , Roh Eun Ji , Darai Anjani , Kyung Jae Won , Choi Hyemin , Kwon Su Yeon , Bhujel Basanta , Han Inbo
Published: February 2021

Intervertebral disc (IVD) degeneration is a leading cause of chronic low back pain (LBP) that results in serious disability and significant economic burden. IVD degeneration alters the disc structure and spine biomechanics, resulting in subsequent structural changes throughout the spine. Currently, treatments of chronic LBP due to IVD degeneration include conservative treatments, such as pain medication and physiotherapy, and surgical treatments, such as removal of herniated disc without or with spinal fusion. However, none of these treatments can completely restore a degenerated disc and its function. Thus, although the exact pathogenesis of disc degeneration remains unclear, there are studies examining the effectiveness of biological approaches, such as growth factor injection, gene therapy, and cell transplantation, in promoting IVD regeneration. Furthermore, tissue engineering using a combination of cell transplantation and biomaterials has emerged as a promising new approach for repair or restoration of degenerated discs. The main purpose of this review was to provide an overview of the current status of tissue engineering applications for IVD regenerative therapy by performing literature searches using PubMed. Significant advances in tissue engineering have opened the door to a new generation of regenerative therapies for the treatment of chronic discogenic LBP.
Job Shop Scheduling Problem Optimization by Means of Graph-Based Algorithm
Authors: Stastny Jiri , Skorpil Vladislav , Balogh Zoltan , Klein Richard
Published: February 2021

In this paper we introduce the draft of a new graph-based algorithm for optimization of scheduling problems. Our algorithm is based on the Generalized Lifelong Planning A* algorithm, which is usually used for path planning for mobile robots. It was tested on the Job Shop Scheduling Problem against a genetic algorithm’s classic implementation. The acquired results of these experiments were compared by each algorithm’s required time (to find the best solution) as well as makespan. The comparison of these results showed that the proposed algorithm exhibited a promising convergence rate toward an optimal solution. Job shop scheduling (or the job shop problem) is an optimization problem in informatics and operations research in which jobs are assigned to resources at particular times. The makespan is the total length of the schedule (when all jobs have finished processing). In most of the tested cases, our proposed algorithm managed to find a solution faster than the genetic algorithm; in five cases, the graph-based algorithm found a solution at the same time as the genetic algorithm. Our results also showed that the manner of priority calculation had a non-negligible impact on solutions, and that an appropriately chosen priority calculation could improve them.
Performance Evaluation of Hybrid WOA-SVR and HHO-SVR Models with Various Kernels to Predict Factor of Safety for Circular Failure Slope
Authors: Wei Wei , Li Xibing , Liu Jingzhi , Zhou Yaodong , Li Lu , Zhou Jian
Published: February 2021

To detect areas with the potential for landslides, slopes are routinely subjected to stability analyses. To this end, there is a need to adopt appropriate mitigation techniques. In general, the stability of slopes with circular failure mode is defined as the factor of safety (FOS). The literature includes a variety of numerical/analytical models proposed in different studies to compute the FOS values of slopes. However, the main challenge is to propose a model for solving a non-linear relationship between independent parameters (which have a great impact on slope stability) and FOS values of slopes. This creates a problem with a high level of complexity and with multiple variables. To resolve the problem, this study proposes a new hybrid intelligent model for FOS evaluation and analysis of slopes in two different phases: simulation and optimization. In the simulation phase, different support vector regression (SVR) kernels were built to predict FOS values. The results showed that the radius basis function (RBF) kernel produces more accurate performance prediction compared with the other applied kernels. The prediction accuracy of this kernel was obtained as coefficient of determination = 0.94, which indicates a high prediction capacity during the simulation phase. Then, in the optimization phase, the proposed SVR model was optimized through the use of two well-known techniques, namely, the whale optimization algorithm (WOA) and Harris hawks optimization (HHO), and the optimum input parameters were obtained. The optimal results confirmed that both optimization techniques are able to achieve a high value for FOS of slopes; however, the HHO shows a more powerful process in FOS maximization compared with the WOA technique. In addition, the developed model was also successfully validated using new data with nine data samples.
Online Distributed Measurement of Dark I-V Curves in Photovoltaic Plants
Authors: Morales-Aragonés José Ignacio , Alonso-García María del Carmen , Gallardo-Saavedra Sara , Alonso-Gómez Víctor , Balenzategui José Lorenzo , Redondo-Plaza Alberto , Hernández-Callejo Luis
Published: February 2021

The inspection techniques for defects in photovoltaic modules are diverse. Among them, the inspection with measurements using current–voltage (I-V) curves is one of the most outstanding. I-V curves, which can be carried under illumination or in dark conditions, are widely used to detect certain defects in photovoltaic modules. In a traditional way, these measurements are carried out by disconnecting the photovoltaic module from the string inside the photovoltaic plant. In this work, the researchers propose a methodology to perform online dark I-V curves of modules in photovoltaic plants without the need of disconnecting them from the string. For this, a combination of electronic boards in the photovoltaic modules and a bidirectional inverter are employed. The results are highly promising, and this methodology could be widely used in upcoming photovoltaic plants.