bluuebunny/crossref_metadata_2025 huggingface dataset:
Adjustment of Planned Surveying and Geodetic Networks Using Second-Order Nonlinear Programming Methods
Authors: Mustafin Murat , Bykasov Dmitry
Published: December 2021

Due to the huge amount of redundant data, the problem arises of finding a single integral solution that will satisfy numerous possible accuracy options. Mathematical processing of such measurements by traditional geodetic methods can take significant time and at the same time does not provide the required accuracy. This article discusses the application of nonlinear programming methods in the computational process for geodetic data. Thanks to the development of computer technology, a modern surveyor can solve new emerging production problems using nonlinear programming methods—preliminary computational experiments that allow evaluating the effectiveness of a particular method for solving a specific problem. The efficiency and performance comparison of various nonlinear programming methods in the course of trilateration network equalization on a plane is shown. An algorithm of the modified second-order Newton’s method is proposed, based on the use of the matrix of second partial derivatives and the Powell and the Davis–Sven–Kempy (DSK) method in the computational process. The new method makes it possible to simplify the computational process, allows the user not to calculate the preliminary values of the determined parameters with high accuracy, since the use of this method makes it possible to expand the region of convergence of the problem solution.
Facilitating Preschool Children’s Mathematics Development in China, Japan, and the United States: Is the Classroom Library Considered?
Authors: Stites Michele L. , Sonnenschein Susan , Chen Yongxiang , Imai-Matsumura Kyoko , Gürsoy Hatice
Published: December 2021

The two studies examined in this paper compare the different mathematical opportunities provided in preschool classrooms in China, Japan, and the United States, with an emphasis on mathematical-themed books in classroom libraries. Study one presents the results of an online survey to examining the content of preschool classroom libraries in China (N = 134), Japan (N = 168), and the United States (N = 291). Study two presents data obtained from semi-structured interviews of teachers in China (N = 8), Japan (N = 8), and the United States (N = 8). The interviews examined teacher perceptions of how they teach mathematics, the importance of teaching mathematics, and the use of the classroom library as a venue for mathematics. Study one results indicated that teachers from all three countries encourage classroom library use; however, teachers from China reported more mathematics storybooks than their Japanese or United States counterparts. Study two results indicated that teachers from all three countries viewed mathematics as important and provided various mathematics learning opportunities to children throughout the school day. Chinese teachers reported providing the most mathematics learning opportunities using whole group instruction, mathematics centers, and free play. Japanese teachers reported few whole group forms of instruction other than circle time but reported providing opportunities for using mathematics during free play and other embedded activities. United States teachers indicated that mathematics learning occurred using whole group instruction and mathematics centers.
Effect of Plasma-Activated Solution Treatment on Cell Biology of Staphylococcus aureus and Quality of Fresh Lettuces
Authors: Zhao Jianying , Qian Jing , Zhuang Hong , Luo Ji , Huang Mingming , Yan Wenjing , Zhang Jianhao
Published: December 2021

This study aimed to investigate effects of plasma-activated solution (PAS) on the cell biology of Staphylococcus aureus and qualities of fresh lettuce leaves. PAS was prepared by dielectric barrier discharge plasma and incubated with S. aureus for 10–30 min or with lettuces for 10 min. Effects on cell biology were evaluated with microscopic images, cell integrity, and chemical modification of cellular components. Effects on lettuce quality were estimated with the viable microbial counts, color, contents of vitamin C and chlorophyll, and surface integrity. PAS reduced S. aureus population by 4.95-log and resulted in increased cell membrane leakage. It also resulted in increased contents of reactive oxygen species in cells, C=O bonds in peptidoglycan, and 8-hydroxydeoxyguanosine content in cellular DNA, and reduced ratios of unsaturated/saturated fatty acids in the cell membrane. PAS treatment reduced bacterial load on fresh lettuce and had no negative effects on the quality. Data suggest that PAS can be used for the disinfection of ready-to-eat fresh vegetables.
Physical and Oxidative Stability of Low-Fat Fish Oil-in-Water Emulsions Stabilized with Black Soldier Fly (Hermetia illucens) Larvae Protein Concentrate
Authors: Queiroz Lucas Sales , Casanova Federico , Feyissa Aberham Hailu , Jessen Flemming , Ajalloueian Fatemeh , Perrone Italo Tuler , de Carvalho Antonio Fernandes , Mohammadifar Mohammad Amin , Jacobsen Charlotte , Yesiltas Betül
Published: December 2021

The physical and oxidative stability of fish oil-in-water (O/W) emulsions were investigated using black soldier fly larvae (BSFL) (Hermetia illucens) protein concentrate as an emulsifier. To improve the protein extraction and the techno-functionality, defatted BSFL powder was treated with ohmic heating (BSFL-OH) and a combination of ohmic heating and ultrasound (BSFL-UOH). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were performed in order to characterize the secondary structure and thermal stability of all protein concentrate samples. The interfacial properties were evaluated by the pendant drop technique. The lowest interfacial tension (12.95 mN/m) after 30 min was observed for BSFL-OH. Dynamic light scattering, ζ-potential and turbiscan stability index (TSI) were used to evaluate the physical stability of emulsions. BSFL-OH showed the smallest droplet size (0.68 μm) and the best emulsion stability (TSI = 8.89). The formation of primary and secondary volatile oxidation products and consumption of tocopherols were evaluated for all emulsions, revealing that OH and ultrasound treatment did not improve oxidative stability compared to the emulsion with untreated BSFL. The results revealed the promising application of BSFL proteins as emulsifiers and the ability of ohmic heating to improve the emulsifying properties of BSFL proteins.
Effect of Essential Oils and Vacuum Packaging on Spoilage-Causing Microorganisms of Marinated Camel Meat during Storage
Authors: Osaili Tareq M. , Hasan Fayeza , Al-Nabulsi Anas A. , Dhanasekaran Dinesh Kumar , Obaid Reyad Shaker , Hashim Mona S. , Radwan Hadia M. , Cheikh Ismail Leila , Hasan Haydar , Faris Moez Al-Islam E. , Naja Farah , Savvaidis Ioannis N. , Olaimat Amin N. , Ayyash Mutamed , Holley Richard
Published: December 2021

The use of essential oils (EOs) and/or vacuum packaging (VP) with meats could increase product shelf-life. However, no studies investigating the effect of EOs and VP on camel meat background microbiota have been conducted previously. The study aimed to analyze the antimicrobial effect of essential oils (EOs) carvacrol (CA), cinnamaldehyde (CI), and thymol (TH) at 1 or 2% plus vacuum packaging (VP) on the growth of spoilage-causing microorganisms in marinated camel meat chunks during storage at 4 and 10 °C. VP is an effective means to control spoilage in unmarinated camel meat (CM) and marinated camel meat (MCM) compared to aerobic packaging (AP). However, after EO addition to MCM, maximum decreases in spoilage-causing microorganisms were observed under AP on day 7. Increasing the temperature from 4 to 10 °C under AP increased the rate of spoilage-causing bacterial growth in CM and MCM; however, EOs were more effective at 10 °C. At 10 °C the maximum reductions in total mesophilic plate counts, yeast and molds, mesophilic lactic Acid bacteria, Enterobacteriaceae, and Pseudomonas spp. were 1.2, 1.4, 2.1, 3.1, and 4.8 log CFU/g, respectively. Incorporating EOs at 2% in MCM, held aerobically under temperature abuse conditions, delayed spoilage.
Preparation and Characterization of Pickering Emulsions with Modified Okara Insoluble Dietary Fiber
Authors: Bao Yue , Xue Hanyu , Yue Yang , Wang Xiujuan , Yu Hansong , Piao Chunhong
Published: December 2021

Modified okara insoluble dietary fiber (OIDF) has attracted great interest as a promising Pickering emulsifier. At present, the modification methods are mainly physicochemical methods, and the research on microbial modified OIDF as stabilizer is not clear. In this work, modified OIDF was prepared by yeast Kluyveromyces marxianus fermentation. The potential of modified OIDF as a Pickering emulsifier and the formation and stability of OIDF-Pickering emulsions stabilized by modified OIDF were characterized, respectively. The results showed that the specific surface area, hydrophilicity, and electronegativity of the modified OIDF were all enhanced compared with the unmodified OIDF. The existence of the network structure between droplets is the key to maintain the stability of the emulsions, as indicated by Croy-Scanning Electron Microscope (Croy-SEM) and rheological properties measurements. The stability of OIDF-Pickering emulsions was evaluated in terms of storage time, centrifugal force, pH value, and ionic strength (NaCl). Moreover, the OIDF-Pickering emulsions stabilized by modified OIDF showed better stability. These results will contribute to the development of efficient OIDF-based emulsifiers, expand the application of emulsions in more fields, and will greatly improve the high-value utilization of okara by-products.
Online Detection of Watercore Apples by Vis/NIR Full-Transmittance Spectroscopy Coupled with ANOVA Method
Authors: Zhang Yifei , Yang Xuhai , Cai Zhonglei , Fan Shuxiang , Zhang Haiyun , Zhang Qian , Li Jiangbo
Published: December 2021

Watercore is an internal physiological disorder affecting the quality and price of apples. Rapid and non-destructive detection of watercore is of great significance to improve the commercial value of apples. In this study, the visible and near infrared (Vis/NIR) full-transmittance spectroscopy combined with analysis of variance (ANOVA) method was used for online detection of watercore apples. At the speed of 0.5 m/s, the effects of three different orientations (O1, O2, and O3) on the discrimination results of watercore apples were evaluated, respectively. It was found that O3 orientation was the most suitable for detecting watercore apples. One-way ANOVA was used to select the characteristic wavelengths. The least squares-support vector machine (LS-SVM) model with two characteristic wavelengths obtained good performance with the success rates of 96.87% and 100% for watercore and healthy apples, respectively. In addition, full-spectrum data was also utilized to determine the optimal two-band ratio for the discrimination of watercore apples by ANOVA method. Study showed that the threshold discrimination model established based on O3 orientation had the same detection accuracy as the optimal LS-SVM model for samples in the prediction set. Overall, full-transmittance spectroscopy combined with the ANOVA method was feasible to online detect watercore apples, and the threshold discrimination model based on two-band ratio showed great potential for detection of watercore apples.
Influence of Commercial Protease and Drying Process on Antioxidant and Physicochemical Properties of Chicken Breast Protein Hydrolysates
Authors: Setthaya Phatthawin , Jaturasitha Sanchai , Ketnawa Sunantha , Chaiyaso Thanongsak , Sato Kenji , Wongpoomchai Rawiwan
Published: December 2021

Different proteases can be applied to produce certain bioactive peptides. This study focused on the effects of some commercial proteases and drying processes on the physical, chemical, and biological properties of chicken breast hydrolysates (CBH). Chicken breast hydrolyzed with Alcalase® presented a higher degree of hydrolysis (DH) than papain. Moreover, the treatment with Alcalase®, followed by papain (A-P), was more proficient in producing antioxidant activities than a single enzyme treatment. Conditions comprising 0.63% Alcalase® (w/w) at pH 8.0 and 52.5 °C for 3 h, followed by 0.13% papain (w/w) at pH 6.0 and 37 °C for 3 h, resulted in the highest yields of DH and peptide contents. The spray-dried microencapsulated powder improved the physicochemical properties including moisture content, color measurement, solubility, and particle morphology. In summary, the dual enzyme application involving the hydrolysis of Alcalase® and papain, coupled with the spray-drying process, could be used to produced antioxidant CBH.
Microalgae as Sources of High-Quality Protein for Human Food and Protein Supplements
Authors: Wang Yanwen , Tibbetts Sean , McGinn Patrick
Published: December 2021

As a result of population growth, an emerging middle-class, and a more health-conscious society concerned with overconsumption of fats and carbohydrates, dietary protein intake is on the rise. To address this rapid change in the food market, and the subsequent high demand for protein products, agriculture, aquaculture, and the food industry have been working actively in recent years to increase protein product output from both production and processing aspects. Dietary proteins derived from animal sources are of the highest quality, containing well-balanced profiles of essential amino acids that generally exceed those of other food sources. However, as a result of studies highlighting low production efficiency (e.g., feed to food conversion) and significant environmental impacts, together with the negative health impacts associated with the dietary intake of some animal products, especially red meats, the consumption of animal proteins has been remaining steady or even declining over the past few decades. To fill this gap, researchers and product development specialists at all levels have been working closely to discover new sources of protein, such as plant-based ingredients. In this regard, microalgae have been recognized as strategic crops, which, due to their vast biological diversity, have distinctive phenotypic traits and interactions with the environment in the production of biomass and protein, offering possibilities of production of large quantities of microalgal protein through manipulating growing systems and conditions and bioengineering technologies. Despite this, microalgae remain underexploited crops and research into their nutritional values and health benefits is in its infancy. In fact, only a small handful of microalgal species are being produced at a commercial scale for use as human food or protein supplements. This review is intended to provide an overview on microalgal protein content, its impact by environmental factors, its protein quality, and its associated evaluation methods. We also attempt to present the current challenges and future research directions, with a hope to enhance the research, product development, and commercialization, and ultimately meet the rapidly increasing market demand for high-quality protein products.
Effect of Chitosan Coatings with Cinnamon Essential Oil on Postharvest Quality of Mangoes
Authors: Yu Kaibo , Xu Jing , Zhou Lei , Zou Liqiang , Liu Wei
Published: December 2021

Mango (Mangifera indica Linn.) is a famous climacteric fruit containing abundant flavor and nutrients in the tropics, but it is prone to decay without suitable postharvest preservation measures. In this study, the chitosan (CH)-cinnamon essential oil (CEO) Pickering emulsion (CH-PE) coating was prepared, with cellulose nanocrystals as the emulsifier, and applied to harvested mangoes at the green stage of maturity. It was compared with a pure CH coating and a CH-CEO emulsion (CH-E) coating, prepared with the emulsifier Tween 80. Results showed that the CH-PE coating had a lower water solubility and water vapor permeability than the other coatings, which was mainly due to electrostatic interactions, and had a better sustained-release performance for CEO than the CH-E coating. During mango storage, the CH-PE coating effectively improved the appearance of mangoes at 25 °C for 12 d by reducing yellowing and dark spots, and delayed water loss. Hardness was maintained and membrane lipid peroxidation was reduced by regulating the activities of pectin methyl esterase, polygalacturonase, and peroxidase. In addition, the nutrient quality was improved by the CH-PE coating, with higher contents of total soluble solid, titratable acid, and ascorbic acid. Therefore, the CH-PE coating is promising to comprehensively maintain the postharvest quality of mangoes, due to its enhanced physical and sustained-release properties.
Use of Artificial Neural Network Model for Rice Quality Prediction Based on Grain Physical Parameters
Authors: Sampaio Pedro Sousa , Almeida Ana Sofia , Brites Carla Moita
Published: December 2021

The main goal of this study was to test the ability of an artificial neural network (ANN) for rice quality prediction based on grain physical parameters and to conduct a comparison with multiple linear regression (MLR) using 66 samples in duplicate. The parameters used for rice quality prediction are related to biochemical composition (starch, amylose, ash, fat, and protein concentration) and pasting parameters (peak viscosity, trough, breakdown, final viscosity, and setback). These parameters were estimated based on grain appearance (length, width, length/width ratio, total whiteness, vitreous whiteness, and chalkiness), and milling yield (husked, milled, head) data. The MLR models were characterized by very low coefficient determination (R2 = 0.27–0.96) and a root-mean-square error (RMSE) (0.08–0.56). Meanwhile, the ANN models presented a range for R2 = 0.97–0.99, being characterized for R2 = 0.98 (training), R2 = 0.88 (validation), and R2 = 0.90 (testing). According to these results, the ANN algorithms could be used to obtain robust models to predict both biochemical and pasting profiles parameters in a fast and accurate form, which makes them suitable for application to simultaneous qualitative and quantitative analysis of rice quality. Moreover, the ANN prediction method represents a promising approach to estimate several targeted biochemical and viscosity parameters with a fast and clean approach that is interesting to industry and consumers, leading to better assessment of rice classification for authenticity purposes.
Methane Fermentation Residue Compost Derived from Food Waste to Aid Komatsuna (Brassica rapa) Growth
Authors: Santi Nur , Dewi Ratih Kemala , Suganuma Yutaka , Iikubo Tsutomu , Seki Hiroichi , Komatsuzaki Masakazu
Published: December 2021

One suitable solution to achieve sustainable development goals (SDGs) is to utilize methane fermentation residue obtained from food waste. However, methane fermentation residue compost is often difficult to use due to its inhibitory properties and pungent smell. To evaluate chemical parameters and plant growth, we examined the use of methane-fermented food waste residue compost (FWM), three types of animal manure, namely, horse manure (HM), cow manure (CWM), and chicken manure (CKM). Our results revealed that mixing food waste compost with cow and horse manure reduced the inhibition of Komatsuna germination, however, chicken manure blending limited inhibition reduction. The improvement of GI in the combination of FWM and animal manure was obtained at a ratio 1:4 with an improvement in GI of 20.8%, 16.8%, and 3.8% for combination FWM + HM, FWM + CWM, and FWM + CKM, respectively. The ratio of the combination of FWM + HM could be increased to a ratio of 2:3 with an improvement of 14.7%. Additionally, for Komatsuna growth, FWM with cow and horse manure mixer considerably enhanced plant growth and yield. Furthermore, the combination of FWM + HM and FWM + CWM could improve the ratio of NUE compost/NUE FWM with the values being 12.0 and 11.1, respectively. Therefore, combining FWM with CWM and HM increases the utility value of methane fermentation residues obtained from food waste as compost for maintaining soil fertility, while reducing the use of chemical fertilizer.
Light Intensity Modulates the Accumulation of Carbohydrates, Antioxidant Enzymes and Production of Iceberg Lettuce under Tropical Conditions
Authors: Aires Eduardo Santana , Aragão Carlos Alberto , Dantas Bárbara França , Rodrigues João Domingos , Ono Elizabeth Orika
Published: December 2021

High solar radiation in tropical regions can affect the development, physiology, and biochemistry of plants. Our aim with this research was to evaluate the biochemical responses and production of iceberg lettuce cultivars under environments with different shadings. An experiment under field conditions was installed in a 4 × 4 factorial scheme. Four cultivars of iceberg lettuce (Great Lakes, Winslow, Delicia, and Balsamo) and four environments with different shadings (three types of shading screens: red, ChromatiNet®, and black; and treatment under the full sun) were evaluated. Forty-five days after transplanting, the plants were harvested, and the biomass was weighed to obtain the fresh consumable part (FCP) and the biochemical parameters: total soluble sugar (TSS), reducing sugar (RS), and the activity of SOD, CAT, and POD. We found that shading modulates biochemical and productive responses of iceberg lettuce, and the main microclimatic factor related to these responses was solar radiation. We observed a negative correlation between RS and FCP. The solar radiation between 16 and 18 MJ·m−2·day−1, observed in the environments with a black screen and ChromatiNet®, promoted the highest activity of the SOD enzyme and average levels of TSS and RS, providing higher FCP of the cultivars Delícia and Balsamo in high temperatures period.
Revisiting the Existence of EKC Hypothesis under Different Degrees of Population Aging: Empirical Analysis of Panel Data from 140 Countries
Authors: Li Shuyu , Li Rongrong
Published: December 2021

Population aging and environmental sustainability have become two hot topics in the world today. To clarify whether the Environmental Kuninets Curve (EKC) hypothesis between the economy and the environment is still valid in the context of population aging is the key to reveal the complexity of social-ecological systems in aging societies. So far, the impact of population aging on the environment has not been clear. To this end, an empirical analysis on the threshold panel model was conducted using panel data of 140 countries from 2000 to 2015. The global findings suggest that economic growth was the main reason for the increase in the ecological footprint at the beginning of aging. However, deepening aging weakened this association between economic and ecological footprints. For high-income countries, with the deepening of aging, the economic and ecological footprints were firstly negatively correlated, then positively correlated, and finally negatively correlated. In other words, the EKC hypothesis remained valid in high-income countries as aging deepened. In contrast, for the low- and middle-income group, the economic-environmental association was not affected by the degree of aging. This result sheds light on the variability of different income country groups in coping with the environmental impacts of aging. For the high-income group, policy makers should pay attention to the aging threshold in socio-ecological management. Only in this way can the development of aging and the ecological environment be reconciled to the greatest extent.
The Relationship of Trunk Muscle Activation and Core Stability: A Biomechanical Analysis of Pilates-Based Stabilization Exercise
Authors: Lee Kyeongjin
Published: December 2021

Pilates is an effective exercise method for rehabilitating musculoskeletal disorders as its principles are based on the activation of local muscles. This study aimed to compare the subjects with and without Pilates experience to find out the effect of the experience on the core muscle activity and muscle co-contraction, and to examine the relationship between the core muscle activation level and the kinematic data. This study involved 32 subjects, including 16 experienced Pilates practitioners and 16 non-experienced subjects. The knee stretch on the reformer was performed in three different positions: flat back with a neutral pelvis, round back with posteriorly tilted pelvis (RPP), and extended back anteriorly tilted pelvis (EAP). The electromyography of the internal oblique (IO), rectus abdominis (RA), multifidus (MU), and iliocostalis lumborum (IL) muscles were measured, as well as kinematic data from a 3D motion analysis system. Compared to the non-experienced subjects, the experienced subjects activated the IO muscles more than the RA muscles, and the most significant difference was seen in the RPP position (p < 0.05). The experienced patients activated the MU muscles more often than the IL muscles, with the most significant difference observed in the RPP position and the least significant in the EAP position (p < 0.05). All kinematic data and muscle activity (IO, IO/RA ratio, MU/IL ratio) showed significant differences between the experienced and non-experienced subjects (p < 0.05). The subjects presented a moderate correlation between muscle activation and core stability. It was confirmed that the experienced Pilates practitioners activated the abdominal and low back core muscles effectively, and the stability of the pelvis and trunk were better than that of the non-experienced participants. In addition, the better the trunk stability was maintained, the larger and more accurate movement of the mobility segment was observed.
The Role of 2D and 3D Echo in Mitral Stenosis
Authors: Monteagudo Ruiz Juan Manuel , Zamorano Gómez José Luis
Published: December 2021

Mitral stenosis is an important cause of heart valve disease globally. Echocardiography is the main imaging modality used to diagnose and assess the severity and hemodynamic consequences of mitral stenosis as well as valve morphology. Transthoracic echocardiography (TTE) is sufficient for the management of most patients. The focus of this review is the role of current two-dimensional (2D) and three-dimensional (3D) echocardiographic imaging for the evaluation of mitral stenosis.
Optical to Planar X-ray Mouse Image Mapping in Preclinical Nuclear Medicine Using Conditional Adversarial Networks
Authors: Fysikopoulos Eleftherios , Rouchota Maritina , Eleftheriadis Vasilis , Gatsiou Christina-Anna , Pilatis Irinaios , Sarpaki Sophia , Loudos George , Kostopoulos Spiros , Glotsos Dimitrios
Published: December 2021

In the current work, a pix2pix conditional generative adversarial network has been evaluated as a potential solution for generating adequately accurate synthesized morphological X-ray images by translating standard photographic images of mice. Such an approach will benefit 2D functional molecular imaging techniques, such as planar radioisotope and/or fluorescence/bioluminescence imaging, by providing high-resolution information for anatomical mapping, but not for diagnosis, using conventional photographic sensors. Planar functional imaging offers an efficient alternative to biodistribution ex vivo studies and/or 3D high-end molecular imaging systems since it can be effectively used to track new tracers and study the accumulation from zero point in time post-injection. The superimposition of functional information with an artificially produced X-ray image may enhance overall image information in such systems without added complexity and cost. The network has been trained in 700 input (photography)/ground truth (X-ray) paired mouse images and evaluated using a test dataset composed of 80 photographic images and 80 ground truth X-ray images. Performance metrics such as peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM) and Fréchet inception distance (FID) were used to quantitatively evaluate the proposed approach in the acquired dataset.
Numerical Investigation of Internal Solitary Wave Forces on Submarines in Continuously Stratified Fluids
Authors: Li Jingyuan , Zhang Qinghe , Chen Tongqing
Published: December 2021

A numerical model of internal solitary waves in continuously stratified fluids is developed by introducing a density transport equation to the three-dimensional Navier–Stokes equation and adopting the fully nonlinear models of the Dubreil-Jacotin-Long equation to obtain the initial field of the ISW. The corresponding turbulence model has also been modified to ensure that it considers the variable density field. Comparisons between numerical simulation results and experimental results show that the total resistance, the nondimensional pressure coefficient, and the nondimensional friction coefficient for the standard submarine model proposed by the Defense Advanced Research Projects Agency under different flow field conditions are highly consistent with the experimental results. The model established is used to numerically analyse the forces and moments of the standard submarine model encountering ISWs at different submergence depths. The influence of the rotation centre position on the moment is discussed, and the position range of the optimal rotation centre is proposed.
Pilot-Assisted OFDM for Underwater Acoustic Communication
Authors: Murad Mohsin , Tasadduq Imran A. , Otero Pablo
Published: December 2021

Multicarrier techniques have made it possible to wirelessly transmit data at higher rates for underwater acoustic (UWA) communication. Several multicarrier techniques have been explored in the past for wireless data transmission. OFDM is known to fight off inter-symbol interference due to the orthogonality of its subcarriers. However, due to time variations, OFDM suffers from intercarrier interference. As the UWA channel is both a time and frequency variant, channel estimation becomes complex. We propose a pilot-based channel estimation technique and explore two equalizers for improving the error performance of an OFDM-based UWA system. Both the equalizers employ pilot subcarriers to estimate the UWA channel. One equalizer is a least squares (LS) equalizer and the other is a zero forcing (ZF) equalizer. Using computer simulations, it is observed that, for an acceptable error performance, the number of pilots should be one-fourth the number of subcarriers. Moreover, if the energy of the pilots is increased without changing the overall symbol energy, the error performance degrades. It is also noted that both the LS and ZF equalizers give an acceptable error performance with the ZF performing marginally better than the LS. Furthermore, the error performance of the proposed system is evaluated as a function of the transmitter-receiver distance and an acceptable error performance is observed even at 1250 m.
Harnessing Endophytic Fungi for Enhancing Growth, Tolerance and Quality of Rose-Scented Geranium (Pelargonium graveolens (L’Hér) Thunb.) Plants under Cadmium Stress: A Biochemical Study
Authors: El-Shafey Nadia Mohamed , Marzouk Marym A. , Yasser Manal M. , Shaban Salwa A. , Beemster Gerrit T.S. , AbdElgawad Hamada
Published: December 2021

Heavy metal contamination in soil is increasing rapidly due to increasing anthropogenic activities. Despite the importance of rose-scented geranium as a medicinal plant, little attention was paid to enhancing its productivity in heavy metal-polluted soil. In this regard, endophytes improve plant resistance to heavy metal toxicity and enhance its tissue quality. Here, the impact of the three endophytic fungi Talaromyces versatilis (E6651), Emericella nidulans (E6658), and Aspergillus niger (E6657) on geranium growth, tolerance, and tissue quality under cadmium (Cd) stress was investigated. In contrast to E. nidulans, T. versatilis and A. niger enhanced geranium growth and the stimulatory effect was more pronounced under Cd-stress. The three endophytes significantly alleviated Cd accumulation and increased mineral content in geranium leaves. In addition, endophytic fungi successfully alleviated Cd-induced membrane damage and reinforced the antioxidant defenses in geranium leaves. Inoculation with endophytes stimulated all the antioxidant enzymes under Cd-stress, and the response was more obvious in the case of T. versatilis and A. niger. To reduce the toxicity of tissue-Cd levels, T. versatilis and A. niger upregulated the detoxification mechanisms; glutathione-S-transferase, phytochelatin, and metallothionein levels. Moreover, endophytic fungi improved the medicinal value and quality of geranium by increasing total antioxidant capacity (TAC), phenolic compound biosynthesis (phenylalanine ammonia-lyase), and vitamin content as well as the quantity and quality of essential oil, particularly under Cd-stress conditions. The variation in the mechanisms modulated by the different endophytic fungi was supported by Principal Component Analysis (PCA). Overall, this study provided fundamental insights into endophytes’ impact as a feasible strategy to mitigate the phytotoxicity hazards of Cd-stress in geranium and enhance its quality, based on the growth and biochemical investigations.
Analysis of the Financial Information Contained in the Texts of Current Reports: A Deep Learning Approach
Authors: Wujec Maciej
Published: December 2021

An important role in the fundamental analysis is played by the acquisition and analysis of various types of information about the company. Text documents are an increasingly important source of this information. Their accurate and quick analysis is an increasingly important challenge for financial analysts. Research in the area of financial text analysis is based on sentiment analysis. The deep neural networks and the stocks’ cumulative abnormal return are used in this article to analyze the sentiment of financial texts. The proposed approach, unlike those used so far, does not require manual labeling of data or the creation of dictionaries and is free from the subjective assessment of the researcher. Taking into account the broad context of words and their meaning in financial texts, it also eliminates the problem of ambiguity of words in various contexts. The sentiment of financial texts presented in this paper is directly related to the market reaction to the information contained in these texts. For texts belonging to one of the two classes (positive or negative) with the highest probability, the deep learning model gives predictions with a precision of 62% for the positive class and 55% for the negative class. The event study results show that the sentiment calculated under the proposed method can be successfully used to determine the probable direction of the market reaction to the information contained in current reports with a 1 percent significance level. The results can be used in market efficiency research, investment strategy development or support of investment analysts using fundamental analysis.
Vulnerabilities and Threats to Natural Forest Regrowth: Land Tenure Reform, Land Markets, Pasturelands, Plantations, and Urbanization in Indigenous Communities in Mexico
Authors: Lazos-Chavero Elena , Meli Paula , Bonfil Consuelo
Published: December 2021

Despite the economic and social costs of national and international efforts to restore millions of hectares of deforested and degraded landscapes, results have not met expectations due to land tenure conflicts, land-use transformation, and top-down decision-making policies. Privatization of land, expansion of cattle raising, plantations, and urbanization have created an increasingly competitive land market, dispossessing local communities and threatening forest conservation and regeneration. In contrast to significant investments in reforestation, natural regrowth, which could contribute to landscape regeneration, has not been sufficiently promoted by national governments. This study analyzes socio-ecological and economic vulnerabilities of indigenous and other peasant communities in the Mexican states of Veracruz, Chiapas, and Morelos related to the inclusion of natural regeneration in their forest cycles. While these communities are located within protected areas (Los Tuxtlas Biosphere Reserve, Montes Azules Biosphere Reserve, El Tepozteco National Park, and Chichinautzin Biological Corridor), various threats and vulnerabilities impede natural regeneration. Although landscape restoration involves complex political, economic, and social relationships and decisions by a variety of stakeholders, we focus on communities’ vulnerable land rights and the impacts of privatization on changes in land use and forest conservation. We conclude that the social, economic, political, and environmental vulnerabilities of the study communities threaten natural regeneration, and we explore necessary changes for incorporating this process in landscape restoration.
Peer Effects on First-Year University Students’ Results: The Role of Classmates’ Academic Performance and Socioeconomic Status
Authors: Granger-Serrano Angela , Villarraga-Orjuela Alexander
Published: December 2021

Peer effects in the context of higher education have lately received increased attention. Higher diversity in the composition of new cohorts of students, generated mainly in countries where public and institutional policies have enabled access to students from low socioeconomic conditions and races who unusually attend postsecondary education, make these effects even more relevant. This research estimates and analyzes the effect of peers’ academic performance and course composition by socioeconomic origin on students’ academic achievement at a private Colombian university between 2008 and 2019. The estimates, by Ordinary Least Squares and Multilevel models, support the existence of significant peer effects. There was a positive effect of peers’ performance on Calculus I academic results, principally of medium and high-performance peers, and a null effect of the socioeconomic level in Calculus I, but a significant effect in Communication Skills I, although with a limited impact. By introducing heterogeneities, it is evident that students perceived a greater benefit from performance improvements from peers who are in the same performance category or socioeconomic level. These results provide evidence of the existence, direction, and magnitude of peer effects in Colombian higher education. Additionally, they suggest that the most relevant characteristic of classmates is their academic performance and not their socioeconomic origin.
Fractional Dynamics of Vector-Borne Infection with Sexual Transmission Rate and Vaccination
Authors: Hussain Shah , Madi Elissa Nadia , Iqbal Naveed , Botmart Thongchai , Karaca Yeliz , Mohammed Wael W.
Published: December 2021

New fractional operators have the aim of attracting nonlocal problems that display fractal behaviour; and thus fractional derivatives have applications in long-term relation description along with micro-scaled and macro-scaled phenomena. Formulated by fractional operators, the formulation of a dynamical system is used in applications for the description of systems with long-range interactions. Vector-borne illnesses are one of the world’s most serious public health issues with a large economic impact on the nations that are impacted. Population increase, urbanization, globalization, and a lack of public health infrastructure have all had a role in the introduction and reemergence of vector-borne illnesses during the last four decades. The control of these infections are important to lessen the economic burden of vector-borne diseases in infected regions. In this research work, we formulate the transmission process of Zika virus with the impact of sexual incidence rate and vaccination in terms of mathematics. We presented the fundamental theory of fractional operators Caputo–Fabrizio (CF) and Atangana–Baleanu (AB) for the analysis of the proposed system. We examine our system of Zika infection and determined the endemic indicator through a next-generation matrix technique. The uniqueness and existence of the solution has been investigated through fixed point theory. Accordingly, a numerical method has been introduced to investigate the dynamical nature of the system and make a comparison of the outcomes of the operators. The impact of different input factors has been conceptualized through dynamical behaviour of the system. We observed that lowering the index of memory, the fractional system provides accurate results about the recommended Zika dynamics and dramatically reduces infected people. It has been proved that high efficacy of a vaccine can lower the level of infection. Moreover, the impact of other parameters on the system of Zika virus infection are highlighted through numerical results.
Scalability of k-Tridiagonal Matrix Singular Value Decomposition
Authors: Tănăsescu Andrei , Carabaş Mihai , Pop Florin , Popescu Pantelimon George
Published: December 2021

Singular value decomposition has recently seen a great theoretical improvement for k-tridiagonal matrices, obtaining a considerable speed up over all previous implementations, but at the cost of not ordering the singular values. We provide here a refinement of this method, proving that reordering singular values does not affect performance. We complement our refinement with a scalability study on a real physical cluster setup, offering surprising results. Thus, this method provides a major step up over standard industry implementations.
Modelling of Heat Transfer Processes in Heat Exchangers for Cardiopulmonary Bypass
Authors: Danilova Valentyna , Shlykov Vladyslav , Kotovskyi Vitalii , Višniakov Nikolaj , Šešok Andžela
Published: December 2021

A model of the heat exchange process in the heat exchanger of the cardiopulmonary bypass device is proposed which allows for automation of the process of temperature regulation in the cardiopulmonary bypass with an accuracy of ±1 °C during cardiac surgery under controlled cooling and warming of the patient’s heart and brain. The purpose of this research is to create a concept and model of the temperature control circuit using the MSC Easy5 system, the creation of mathematical models of blocks of the temperature control circuit, and the description of the principle of temperature control in the cardiopulmonary bypass circuit. The model of the temperature control loop in the heat exchanger of the heart-lung machine was created using the MSC Easy5 system with a programmable microcontroller. The microcontroller implements a specialized temperature control algorithm in the C language. The model allows the creation of a full-fledged virtual prototype of a temperature control device in a heat exchanger, and helps to conduct virtual tests of the developed device at the design stage. The model identifies control system flaws and influences decisions made before producing an official prototype of the product.
An Efficient Visually Meaningful Quantum Walks-Based Encryption Scheme for Secure Data Transmission on IoT and Smart Applications
Authors: El-Latif Ahmed A. Abd , Iliyasu Abdullah M. , Abd-El-Atty Bassem
Published: December 2021

Smart systems and technologies have become integral parts of modern society. Their ubiquity makes it paramount to prioritise securing the privacy of data transferred between smart devices. Visual encryption is a technique employed to obscure images by rendering them meaningless to evade attention during transmission. However, the astounding computing power ascribed to quantum technology implies that even the best visually encrypted systems can be effortlessly violated. Consequently, the physical realisation quantum hardware portends great danger for visually encrypted date on smart systems. To circumvent this, our study proposes the integration of quantum walks (QWs) as a cryptographic mechanism to forestall violation of the integrity of images on smart systems. Specifically, we use QW first to substitute the original image and to subsequently permutate and embed it onto the reference image. Based on this structure, our proposed quantum walks visually meaningful cryptosystem facilities confidential transmission of visual information. Simulation-based experiments validate the performance of the proposed system in terms of visual quality, efficiency, robustness, and key space sensitivity, and by that, its potential to safeguard smart systems now and as we transition to the quantum era.
E-Learning Platform Assessment and Selection Using Two-Stage Multi-Criteria Decision-Making Approach with Grey Theory: A Case Study in Vietnam
Authors: Toan Pham Ngoc , Dang Thanh-Tuan , Hong Le Thi Thu
Published: December 2021

Education has changed dramatically due to the severe global pandemic COVID-19, with the phenomenal growth of e-learning, whereby teaching is undertaken remotely and on digital platforms. E-learning is revolutionizing education systems, as it remains the only option during the ongoing crisis and has tremendous potential to fulfill instructional plans and safeguard students’ learning rights. The selection of e-learning platforms is a multi-criteria decision-making (MCDM) problem. Expert analyses over numerous criteria and alternatives are usually linguistic terms, which can be represented through grey numbers. This article proposes an integrated approach of grey analytic hierarchy process (G-AHP) and grey technique for order preference by similarity to ideal solution (G-TOPSIS) to evaluate the best e-learning website for network teaching. This introduced approach handles the linguistic evaluation of experts based on grey systems theory, estimates the relative importance of evaluation criteria with the G-AHP method, and acquires e-learning websites’ ranking utilizing G-TOPSIS. The applicability and superiority of the presented method are illustrated through a practical e-learning website selection case in Vietnam. From G-AHP analysis, educational level, price, right and understandable content, complete content, and up-to-date were found as the most impactful criteria. From G-TOPSIS, Edumall is the best platform. Comparisons are conducted with other MCDM methods; the priority orders of the best websites are similar, indicating the robust proposed methodology. The proposed integrated model in this study supports the stakeholders in selecting the most effective e-learning environments and could be a reference for further development of e-learning teaching-learning systems.
XCM: An Explainable Convolutional Neural Network for Multivariate Time Series Classification
Authors: Fauvel Kevin , Lin Tao , Masson Véronique , Fromont Élisa , Termier Alexandre
Published: December 2021

Multivariate Time Series (MTS) classification has gained importance over the past decade with the increase in the number of temporal datasets in multiple domains. The current state-of-the-art MTS classifier is a heavyweight deep learning approach, which outperforms the second-best MTS classifier only on large datasets. Moreover, this deep learning approach cannot provide faithful explanations as it relies on post hoc model-agnostic explainability methods, which could prevent its use in numerous applications. In this paper, we present XCM, an eXplainable Convolutional neural network for MTS classification. XCM is a new compact convolutional neural network which extracts information relative to the observed variables and time directly from the input data. Thus, XCM architecture enables a good generalization ability on both large and small datasets, while allowing the full exploitation of a faithful post hoc model-specific explainability method (Gradient-weighted Class Activation Mapping) by precisely identifying the observed variables and timestamps of the input data that are important for predictions. We first show that XCM outperforms the state-of-the-art MTS classifiers on both the large and small public UEA datasets. Then, we illustrate how XCM reconciles performance and explainability on a synthetic dataset and show that XCM enables a more precise identification of the regions of the input data that are important for predictions compared to the current deep learning MTS classifier also providing faithful explainability. Finally, we present how XCM can outperform the current most accurate state-of-the-art algorithm on a real-world application while enhancing explainability by providing faithful and more informative explanations.