bluuebunny/crossref_metadata_2025 huggingface dataset:
PVA Films with Mixed Silver Nanoparticles and Gold Nanostars for Intrinsic and Photothermal Antibacterial Action
Authors: Grisoli Pietro , De Vita Lorenzo , Milanese Chiara , Taglietti Angelo , Diaz Fernandez Yuri , Bouzin Margaux , D’Alfonso Laura , Sironi Laura , Rossi Silvia , Vigani Barbara , Sperandeo Paola , Polissi Alessandra , Pallavicini Piersandro
Published: May 2021

PVA films with embedded either silver nanoparticles (AgNP), NIR-absorbing photothermal gold nanostars (GNS), or mixed AgNP+GNS were prepared in this research. The optimal conditions to obtain stable AgNP+GNS films with intact, long lasting photothermal GNS were obtained. These require coating of GNS with a thiolated polyethylene glycol (PEG) terminated with a carboxylic acid function, acting as reticulant in the film formation. In the mixed AgNP+GNS films, the total noble metal content is <0.15% w/w and in the Ag films < 0.025% w/w. The slow but prolonged Ag+ release from film-embedded AgNP (8–11% of total Ag released after 24 h, in the mixed films) results in a very strong microbicidal effect against planktonic Escherichia coli and Staphylococcus aureus bacterial strains (the release of Au from films is instead negligible). Beside this intrinsic effect, the mixed films also exert an on-demand, fast hyperthermal bactericidal action, switched on by NIR laser irradiation (800 nm, i.e., inside the biotransparent window) of the localized surface plasmon resonance (LSPR) absorption bands of GNS. Temperature increases of 30 °C are obtained using irradiances as low as 0.27 W/cm2. Moreover, 80–90% death on both strains was observed in bacteria in contact with the GNS-containing films, after 30 min of irradiation. Finally, the biocompatibility of all films was verified on human fibroblasts, finding negligible viability decrease in all cases.
Defects and Strain Engineering of Structural, Elastic, and Electronic Properties of Boron-Phosphide Monolayer: A Hybrid Density Functional Theory Study
Authors: Li Fang-Qiang , Zhang Yang , Zhang Sheng-Li
Published: May 2021

Defects and in-plane strain have significant effects on the electronic properties of two-dimensional nanostructures. However, due to the influence of substrate and environmental conditions, defects and strain are inevitable during the growth or processing. In this study, hybrid density functional theory was employed to systematically investigate the electronic properties of boron-phosphide monolayers tuned by the in-plane biaxial strain and defects. Four types of defects were considered: B-vacancy (B_v), P-vacancy (P_v), double vacancy (D_v), and Stone–Wales (S-W). Charge density difference and Bader charge analysis were performed to characterize the structural properties of defective monolayers. All of these defects could result in the boron-phosphide monolayer being much softer with anisotropic in-plane Young’s modulus, which is different from the isotropic modulus of the pure layer. The calculated electronic structures show that the P_v, D_v, and S-W defective monolayers are indirect band gap semiconductors, while the B_v defective system is metallic, which is different from the direct band gap of the pure boron-phosphide monolayer. In addition, the in-plane biaxial strain can monotonically tune the band gap of the boron-phosphide monolayer. The band gap increases with the increasing tension strain, while it decreases as the compression strain increases. Our results suggest that the defects and in-plane strain are effective for tuning the electronic properties of the boron-phosphide monolayer, which could motivate further studies to exploit the promising application in electronics and optoelectronics based on the boron-phosphide monolayer.
Improved Device Distribution in High-Performance SiNx Resistive Random Access Memory via Arsenic Ion Implantation
Authors: Yen Te-Jui , Chin Albert , Gritsenko Vladimir
Published: May 2021

Large device variation is a fundamental challenge for resistive random access memory (RRAM) array circuit. Improved device-to-device distributions of set and reset voltages in a SiNx RRAM device is realized via arsenic ion (As+) implantation. Besides, the As+-implanted SiNx RRAM device exhibits much tighter cycle-to-cycle distribution than the nonimplanted device. The As+-implanted SiNx device further exhibits excellent performance, which shows high stability and a large 1.73 × 103 resistance window at 85 °C retention for 104 s, and a large 103 resistance window after 105 cycles of the pulsed endurance test. The current–voltage characteristics of high- and low-resistance states were both analyzed as space-charge-limited conduction mechanism. From the simulated defect distribution in the SiNx layer, a microscopic model was established, and the formation and rupture of defect-conductive paths were proposed for the resistance switching behavior. Therefore, the reason for such high device performance can be attributed to the sufficient defects created by As+ implantation that leads to low forming and operation power.
The Relationship between Bodyweight Status and Weight Perception Explains Differences in Calories Ordered in a Food Choice Exercise
Authors: Mbarushimana Jean-Claude , Gustafson Christopher R. , Gitungwa Henriette , Zeballos Eliana
Published: May 2021

Understanding food choice is critical to be able to address the rise in obesity rates around the globe. In this paper, we examine the relationship between measured (BMI, using self-reported height and weight) and perceived weight status with the number of calories ordered in a controlled online food choice exercise. A total of 1044 participants completed an online food choice exercise in which they selected ingredients for a sandwich from five categories: meat/protein, cheese, spread/dressing, bread, and vegetables. We examine the number of calories ordered by participants and use linear regression to study the relationship of BMI category relative to self-reported perceived weight status with calories ordered. As a comparison to previous literature, we also examine the relationship between relative weight status and self-reported dieting behavior using logistic regression. We find that participants perceiving themselves to have a higher BMI than their BMI calculated using height and weight ordered significantly fewer calories and were more likely to report dieting than participants who perceived themselves to have a lower BMI than their calculated BMI. The relationship between perceived weight status and measured weight status explains behavior in a food choice task. Understanding how people perceive their weight may help design effective health messages.
Raising Children on a Vegan Diet: Parents’ Opinion on Problems in Everyday Life
Authors: Bivi Daisy , Di Chio Teresa , Geri Francesca , Morganti Riccardo , Goggi Silvia , Baroni Luciana , Mumolo Maria Gloria , de Bortoli Nicola , Peroni Diego Giampietro , Marchi Santino , Bellini Massimo
Published: May 2021

A growing number of Italian families are adopting a vegan diet (VD) for their offspring from infancy for various reasons, with health benefits and ethics being the most common reasons. Barriers to effective communication with primary care pediatricians (PCPs) are perceived by many parents and, depending on the actors involved and the environment, a VD may affect social interactions in everyday life. A national cross-sectional survey was conducted between July and September 2020. Parents of children following a VD completed an online questionnaire. Data from 176 Italian parents were collected. About 72% (71.8%) of the children included in this study had been on a VD since weaning. Parents did not inform their primary care pediatricians (PCP) about the VD in 36.2% of the cases. In 70.8% of the cases, PCPs were perceived as skeptical or against a VD. About 70% (71.2%) of the parents relied on medical dietitians, and 28.2% on nutritionists/dietitians for dietary counseling. Parents administered an individual B12 supplement in 87.2% of the cases. To the best of our knowledge, this survey is the first which explores the relationship between vegan parents and their PCPs, the parental management of their children’s diet and problems regarding the implementation of a VD in everyday life.
Association between Creativity and Memory with Cardiorespiratory Fitness and Lifestyle among Chilean Schoolchildren
Authors: Caamaño-Navarrete Felipe , Latorre-Román Pedro Á. , Párraga-Montilla Juan A. , Álvarez Cristian , Delgado-Floody Pedro
Published: May 2021

The objective was to investigate the association between creativity and memory with cardiorespiratory fitness (CRF; i.e., CFR classification and V˙O2max); lifestyle parameters (i.e., physical activity (PA), sleep duration, screen time (ST), and food habits); and anthropometric measures (i.e., body mass index (BMI), waist circumference (WC)) among Chilean schoolchildren. A total of 248 schoolchildren (137 boys, 111 girls, 11.80 ± 1.17 and 11.58 ± 1.09 years, respectively) participated in the cross-sectional study. Creativity, memory, concentration, and selective attention and lifestyle (PA, ST, sleep duration, and Mediterranean diet (MD) adherence) were measured using a standard questionnaire. CRF (measured by the 20 m shuttle run test and expressed as maximum oxygen consumption (V˙O2max) and anthropometric measures (BMI and WC) were also included. Creativity showed a positive association with V˙O2max (mL/kg/min) (β; 0.209, 95% CI; 0.02–0.40, p = p < 0.05) and MD Adherence (score) (β; 0.206, 95% CI; 0.01; 0.74, p = p < 0.05). Long-term memory reported a positive association with CRF (β; 1.076, 95% CI; 0.02–2.13, p = p < 0.05). An increase in CRF levels, together with healthy food habits and normal nutritional status, should be a target for community- and school-based interventions to promote cognitive development in creativity and memory among schoolchildren.
Salmonella enterica Subsp. houtenae Associated with an Abscess in Young Roe Deer (Capreolus capreolus)
Authors: Trotta Adriana , Del Sambro Laura , Galgano Michela , Ciccarelli Stefano , Ottone Erika , Simone Domenico , Parisi Antonio , Buonavoglia Domenico , Corrente Marialaura
Published: May 2021

Background: S. enterica subsp. houtenae has been rarely documented, and very limited genomic information is available. This report describes a rare case of primary extraintestinal salmonellosis in a young roe deer, associated with Salmonella enterica subsp. houtenae. Methods: A traditional cultural-based analysis was carried out from the contents of a neck abscess; biochemical identification and PCR assay were performed to isolate and identify the pathogen. Through whole-genome sequencing (WGS), multilocus sequence typing (MLST), core genome MLST (cgMLST), and the Salmonella pathogenicity islands (SPIs) survey, resistome and virulome genes were investigated to gain insight into the virulence and antimicrobial resistance of S. houtenae. Results: Biochemical identification and PCR confirmed the presence of Salmonella spp. in the swelling. The WGS analysis identified Salmonella enterica subspecies houtenae serovar 43:z4,z23:- and ST 958. The virulence study predicted a multidrug resistance pattern with resistance shown against aminoglycosides, tetracycline, beta-lactamase, fluoroquinolones, fosfomycin, nitroimidazole, aminocoumarin, and peptide. Fifty-three antibiotic-resistant genes were identified. No plasmids were detected. Conclusion: This study demonstrates the importance of continuous surveillance of pathogenic salmonellae. Biomolecular analyses combined with epidemiological data can provide important information about poorly described Salmonella strains and can help to improve animal welfare.
Property-Tuneable Microgels Fabricated by Using Flow-Focusing Microfluidic Geometry for Bioactive Agent Delivery
Authors: Lai Wing-Fu , Wong Wing-Tak
Published: May 2021

Gelatine methacryloyl (GM) shows high biocompatibility and is extensively used in tissue engineering; however, few works have explored the use of GM in bioactive agent delivery. This study adopts a microfluidic approach involving the use of flow-focusing microfluidic geometry for microgel fabrication. This approach generates highly monodisperse microgels whose size can be tuned by altering various fabrication conditions (including the concentration of the gel-forming solution and the flow rates of different phases). By using tetracycline hydrochloride as a model agent, the fabricated microgels enable prolonged agent release, with the encapsulation efficiency being around 30–40% depending on the concentration of the gel-forming solution. Along with their negligible cytotoxicity, our microgels show the potential to serve as carriers of bioactive agents for food and pharmaceutical applications.
The Prospering of Macromolecular Materials Based on Plant Oils within the Blooming Field of Polymers from Renewable Resources
Authors: Silva Julio Antonio Conti , Grilo Luan Moreira , Gandini Alessandro , Lacerda Talita Martins
Published: May 2021

This paper provides an overview of the recent progress in research and development dealing with polymers derived from plant oils. It highlights the widening interest in novel approaches to the synthesis, characterization, and properties of these materials from renewable resources and emphasizes their growing impact on sustainable macromolecular science and technology. The monomers used include unmodified triglycerides, their fatty acids or the corresponding esters, and chemically modified triglycerides and fatty acid esters. Comonomers include styrene, divinylbenzene, acrylics, furan derivatives, epoxides, etc. The synthetic pathways adopted for the preparation of these materials are very varied, going from traditional free radical and cationic polymerizations to polycondensation reactions, as well as metatheses and Diels–Alder syntheses. In addition to this general appraisal, the specific topic of the use of tung oil as a source of original polymers, copolymers, and (nano)composites is discussed in greater detail in terms of mechanisms, structures, properties, and possible applications.
Performance of the IMERG Precipitation Products over High-latitudes Region of Finland
Authors: Mahmoud Mohammed T. , Mohammed Safa A. , Hamouda Mohamed A. , Dal Maso Miikka , Mohamed Mohamed M.
Published: May 2021

Highly accurate and real-time estimation of precipitation over large areas remains a fundamental challenge for the hydrological and meteorological community. This is primarily attributed to the high heterogeneity of precipitation across temporal and spatial scales. Rapid developments in remote sensing technologies have made the quantitative measurement of precipitation by satellite sensors a significant data source. The Global Precipitation Measurement (GPM) mission makes precipitation data with high temporal and spatial resolutions available to different users. The objective of this study is to evaluate the accuracy of Integrated Multi-satellite Retrievals for GPM (IMERG) V06 (Early, Late, and Final) satellite precipitation products (SPPs) at high latitudes. Ground-based observation data across Finland were used as a reference and compared with IMERG data from 2014 to 2019. Three aspects were evaluated: the spatial coverage of the satellite estimates over Finland; the accuracy of the satellite estimates at various temporal scales (half-hourly, daily, and monthly); and the variation in the performance of SPPs over different spatial regions. The results showed that IMERG SPPs can be used with high confidence over Southern, Eastern, and Western Finland. These SPPs can be used with caution over the region of the historical province of Oulu but are not recommended for higher latitudes over Lapland. In general, the IMERG-Final SPP performed the best, and it is recommended for use because of its low number of errors and high correlation with ground observation. Furthermore, this SPP can be used to complement or substitute ground precipitation measurements in ungauged and poorly gauged regions in Southern Finland.
Phytoplankton Biomass and the Hydrodynamic Regime in NEOM, Red Sea
Authors: Papagiannopoulos Nikolaos , Raitsos Dionysios E. , Krokos Georgios , Gittings John A. , Brewin Robert J. W. , Papadopoulos Vassilis P. , Pavlidou Alexandra , Selmes Nick , Groom Steve , Hoteit Ibrahim
Published: May 2021

NEOM (short for Neo-Mustaqbal) is a $500 billion coastal city megaproject, currently under construction in the northwestern part of the Red Sea, off the coast of Tabuk province in Saudi Arabia, and its success will rely on the preservation of biodiverse marine ecosystems. Monitoring the variability of ecological indicators, such as phytoplankton, in relation to regional environmental conditions, is the foundation for such a goal. We provide a detailed description of the phytoplankton seasonal cycle of surface waters surrounding NEOM using satellite-derived chlorophyll-a (Chl-a) observations, based on a regionally-tuned product of the European Space Agency’s Ocean Colour Climate Change Initiative, at 1 km resolution, from 1997 to 2018. The analysis is also supported with in situ cruise datasets and outputs of a state-of-the-art high-resolution hydrodynamic model. The open waters of NEOM follow the oligotrophic character of the Northern Red Sea (NRS), with a peak during late winter and a minimum during late summer. Coral reef-bound regions, such as Sindala and Sharma, are characterised by higher Chl-a concentrations that peak during late summer. Most of the open waters around NEOM are influenced by the general cyclonic circulation of the NRS and local circulation features, while shallow reef-bound regions are more isolated. Our analysis provides the first description of the phytoplankton seasonality and the oceanographic conditions in NEOM, which may support the development of a regional marine conservation strategy.
A Spatiotemporal Change Detection Method for Monitoring Pine Wilt Disease in a Complex Landscape Using High-Resolution Remote Sensing Imagery
Authors: Zhang Biyao , Ye Huichun , Lu Wei , Huang Wenjiang , Wu Bo , Hao Zhuoqing , Sun Hong
Published: May 2021

Using high-resolution remote sensing data to identify infected trees is an important method for controlling pine wilt disease (PWD). Currently, single-date image classification methods are widely used for PWD detection in pure stands of pine. However, they often yield false detections caused by deciduous trees, brown herbaceous, and sparsely vegetated regions in complex landscapes, resulting in low user accuracies. Due to the limitations on the bands of the high-resolution imagery, it is difficult to distinguish wilted pine trees from such easily confused objects when only using the optical spectral characteristics. This paper proposes a spatiotemporal change detection method to reduce false detections in tree-scale PWD monitoring under a complex landscape. The framework consisted of three parts, which represent the capture of spectral, temporal, and spatial features: (1) the Normalized Green–Red Difference Index (NGRDI) was calculated as a descriptor of canopy greenness; (2) two NGRDI images with similar dates in adjacent years were contrasted to obtain a bitemporal change index that represents the temporal behaviors of typical cover types; and (3) a spatial enhancement was performed on the change index using a convolution kernel matching the spatial patterns of PWD. Finally, a set of criteria based on the above features were established to extract the wilted pine trees. The results showed that the proposed method effectively distinguishes wilted pine trees from other easily confused objects. Compared with single-date image classification, the proposed method significantly improved user’s accuracy (81.2% vs. 67.7%) while maintaining the same level of producer’s accuracy (84.7% vs. 82.6%).
Empirical Study of a Room-Level Localization System Based on Bluetooth Low Energy Beacons
Authors: García-Paterna Pedro J. , Martínez-Sala Alejandro S. , Sánchez-Aarnoutse Juan Carlos
Published: May 2021

The ability to locate an object or a person at room-level inside a building or a house could have multiple applications. In this study, we adapt the fingerprint technique using Bluetooth Low Energy to locate the exact room of a person, seeking a simple and low-cost solution. The system is based on BLE beacons deployed at fixed positions and a person carrying a BLE scanner that generates fingerprints from the BLE beacons in coverage. We formulate it as a classification problem where each room is a class; the objective is to estimate the exact room, trying to maximize the area and number of rooms, but also trying to minimize the number of BLE beacons. The room estimation engine is based on a kNN (k-nearest neighbors) classifier. We evaluate the accuracy in two real scenarios and empirically measure the room estimation success related to the number of BLE beacons. As a proof-of-concept, a laptop and a Raspberry Pi are used as BLE scanners to test different hardware. We follow a measurement campaign for several days at different times to evaluate the stability and repeatability of the system. With just a few beacons an accuracy between 70 and 90% is achieved for house and university scenarios.
Validity Evaluation of an Inertial Measurement Unit (IMU) in Gait Analysis Using Statistical Parametric Mapping (SPM)
Authors: Park Sangheon , Yoon Sukhoon
Published: May 2021

Inertial measurement units (IMUs) are possible alternatives to motion-capture systems (Mocap) for gait analysis. However, IMU-based system performance must be validated before widespread clinical use. Therefore, this study evaluated the validity of IMUs using statistical parametric mapping (SPM) for gait analysis. Ten healthy males (age, 30.10 ± 3.28 years; height, 175.90 ± 5.17 cm; weight: 82.80 ± 17.15 kg) participated in this study; they were asked to walk normally on a treadmill. Data were collected during walking at the self-selected speeds (preferred speed, 1.34 ± 0.10 m/s) using both Mocap and an IMU. Calibration was performed directly before each gait measurement to minimize the IMU drift error over time. The lower-extremity joint angles of the hip, knee, and ankle were calculated and compared with IMUs and Mocap; the hip-joint angle did not differ significantly between IMUs and Mocap. There were significant differences in the discrete (max, min, and range of motion) and continuous variables (waveform: 0–100%) of the knee and ankle joints between IMUs and Mocap, particularly on the swing phase (p < 0.05). Our results suggest that IMU-based data can be used confidently during the stance phase but needs evaluation regarding the swing phase in gait analysis.
Novel Stable Capacitive Electrocardiogram Measurement System
Authors: Chen Chi-Chun , Lin Shu-Yu , Chang Wen-Ying
Published: May 2021

This study presents a noncontact electrocardiogram (ECG) measurement system to replace conventional ECG electrode pads during ECG measurement. The proposed noncontact electrode design comprises a surface guard ring, the optimal input resistance, a ground guard ring, and an optimal voltage divider feedback. The surface and ground guard rings are used to reduce environmental noise. The optimal input resistor mitigates distortion caused by the input bias current, and the optimal voltage divider feedback increases the gain. Simulated gain analysis was subsequently performed to determine the most suitable parameters for the design, and the system was combined with a capacitive driven right leg circuit to reduce common-mode interference. The present study simulated actual environments in which interference is present in capacitive ECG signal measurement. Both in the case of environmental interference and motion artifact interference, relative to capacitive ECG electrodes, the proposed electrodes measured ECG signals with greater stability. In terms of R–R intervals, the measured ECG signals exhibited a 98.6% similarity to ECGs measured using contact ECG systems. The proposed noncontact ECG measurement system based on capacitive sensing is applicable for use in everyday life.
Digital Proficiency and Psychological Well-Being in Online Learning: Experiences of First-Generation College Students and Their Peers
Authors: Deng Xuefei (Nancy) , Yang Zheng
Published: May 2021

The study examines the role of digital proficiency in relation to psychological well-being of a vulnerable population—first-generation college students (FGS)—and their counterparts, continuing-education students, in online learning during the coronavirus pandemic (COVID-19). Informed by positive computing and FGS studies, this paper empirically tests a model of three key influencing factors by using a data sample (n = 309) collected from a minority-serving university in the U.S. in April 2020. Our data analysis confirms that FGS underperformed in digital proficiency, compared to their peers. Moreover, digital proficiency had a significant effect on individual psychological well-being, regardless of a student’s generational status. Our paper contributes to the positive computing research by empirically demonstrating the association between users’ technology competence and psychological well-being. Practically, our findings highlight the importance of implementing educational programs and policies to promote the digital skills and well-being of underserved students such as FGS in college education.
The E-Scooter Potential to Change Urban Mobility—Belgrade Case Study
Authors: Glavić Draženko , Trpković Ana , Milenković Marina , Jevremović Sreten
Published: May 2021

As we witness a global change occurring with the advent of e-scooters (electric scooters), it is clear that adequate measures need to be taken for the implementation of this means of transport. Bearing in mind that the user should be the focus of the proposed measures, the aim of this paper encompasses the analysis of e-scooter users’ travel patterns, as well as standard scooter users’ willingness to switch to e-scooters for different hypothetical scenarios, and the determination of factors that have an influence on the users’ willingness to switch. The scenarios include the availability of various infrastructure capacities for the city of Belgrade, namely, a separate infrastructure for e-scooters, or sharing the existing infrastructure with cyclists, pedestrians and motor vehicles. Standard methods of descriptive statistics, the McNemar–Bowker test of paired samples, and multinomial logistic regression were used in this paper. The results showed that there was a statistically significant difference in users’ willingness to use an e-scooter, depending on the available infrastructure. The results of multinomial logistic regression showed that the mode of transport used before and during the COVID-19 pandemic, as well as the average distance traveled, had a statistically significant impact on the users’ willingness to switch to e-scooters if they were allowed to use the cycling infrastructure. This paper also identifies additional factors that have a positive (environmental benefits, congestion avoidance) and negative (safety issues, lack of infrastructure, etc.) impact on users’ willingness to switch, which can be of use to decision-makers as a basic guideline for the adequate implementation of e-scooters in transport systems.
Sustainability of Food Placement in Retailing during the COVID-19 Pandemic
Authors: Končar Jelena , Marić Radenko , Vukmirović Goran , Vučenović Sonja
Published: May 2021

This work aims to define the impact of different indicators on the sustainability of food placement in the retail sector, during periods of crisis and emergencies, such as the COVID-19 pandemic. An empirical survey conducted in the Western Balkans (WB) region showed that indicators such as developed infrastructure, consistency, and transparency of the supply chain, skilled workers, costs, food safety, food prices, energy consumption, and changes in consumer needs are statistically significant since they affect the sustainability of food placement in the retail sector. As food placement and the retail sector itself are inseparable from other participants in the food supply chain (FSC), an analysis was conducted at the level of all FSC sectors. The results showed some deviations viewed individually in the sectors of production, physical distribution, wholesale, and retail, and in selected Western Balkan countries. Based on the results obtained, the sustainability model of food placement in the retail sector has been defined. The model will serve as the basis for defining the set of measures and incentives that competent institutions and FSC management need to undertake, to minimize the impact of indicators that endanger sustainability. The originality of the study lies in the fact that it fills the research gap that exists in this subject matter in academic research and studies in the WB region. In addition, some indicators important for food placement have been precisely isolated, with the definition of the intensity of their impact, observed overall at the level of the entire FSC as well as by individual sectors. Guidelines and suggestions for future research are listed in the paper.
Combining Management, Education and Participation for the Transformation of Universities towards Sustainability: The Trébol Programme
Authors: Gomera Antonio , de Toro Ana , Aguilar José Emilio , Guijarro Clara , Antúnez Miguel , Vaquero-Abellán Manuel
Published: May 2021

This article presents the design and development of the ‘Trébol (Clover) Programme’, a tool which allows us to improve environmental sustainability in the university environment by reinforcing the education, awareness, and training of its members. The system for certifying ‘good practice’ is divided into four progressive levels, and a certificate is awarded in order to demonstrate the environmental commitment acquired to third parties. The aim of the whole process is to create a practical forum for participation, communication, motivation and competence, which is necessary to foster effective pro-environmental behaviour. The study took place at the University of Córdoba (Spain), and, since it began in the 2013/2014 academic year, over 50 groups a wide range of areas have taken part, making a total of nearly 600 participants. The results show that the Trébol Programme enables environmental commitment to be put into practice, through continuous, systematised, participative and well-organised improvements in environmental performance. Its potential as an educational resource for environmental improvement should also be noted, by boosting environmental awareness and establishing new norms. It fits in well with the principles and areas of action of Education for Sustainable Development, and can be applied to universities and other settings to bring about a shift towards sustainability in the fields of teaching, research and management.
Sustainable Development Evaluation of Innovation and Entrepreneurship Education of Clean Energy Major in Colleges and Universities Based on SPA-VFS and GRNN Optimized by Chaos Bat Algorithm
Authors: Liang Yi , Wang Haichao , Hong Wei-Chiang
Published: May 2021

The research on the sustainability evaluation of innovation and entrepreneurship education for clean energy majors in colleges and universities can not only cultivate more and better innovative and entrepreneurial talents for the development of sustainable energy but also provide a reference for the sustainable development of innovation and entrepreneurship education for other majors. To achieve systematic and comprehensive scientific evaluation, this paper proposes an evaluation model based on SPA-VFS and Chaos bat algorithm to optimize GRNN. Firstly, the sustainability evaluation index system of innovation and entrepreneurship education for clean energy major in colleges and universities is constructed from the four aspects of the environment, investment, process, and results, and the meaning of each evaluation index is explained; Then, combined with variable fuzzy set evaluation theory (VFS) and set pair analysis theory (SPA), the classical evaluation model based on SPA-VFS is constructed, and the entropy weight method and rank method are coupled to obtain the index weight. The basic bat algorithm is improved by using Tent chaotic mapping, and the chaotic bat algorithm (CBA) is proposed. The generalized regression neural network (GRNN) model is optimized by CBA, and the intelligent evaluation model based on CBA-GRNN is obtained to realize fast real-time calculation; finally, a numerical example is used to verify the scientificity and accuracy of the model proposed in this paper. This study is conducive to a comprehensive evaluation of the sustainability of innovation and entrepreneurship education for clean energy major in colleges and universities, and is conducive to the healthy and sustainable development of innovation and entrepreneurship education for clean energy major in colleges and universities, so as to provide more innovative and entrepreneurial talents for the clean energy industry.
Towards an Understanding of the Pre-War Landscape Transformations in the Face of Contemporary Urban Challenges on the Example of Gajowice in Wrocław
Authors: Gierko Aleksandra
Published: May 2021

This paper discusses the results of desk and field studies conducted in the Gajowice estate in Wrocław. The aim of the paper is to identify the original assumptions of the development of areas around multifamily buildings and to examine the process of their transformation to the present day. The research hypothesis states that the used solutions would now be defined as green infrastructure or nature-based solutions. This was confirmed with the help of comparative cartographic studies. Research on the original land development of the interwar period allows for identifying the principles based not only on compositional aspects, but also the recognition of natural values in the variety of green forms used in a given area and the important role of trees with large target sizes, in addition to the principle of shaping the green system that permeates the urban tissue, creating ecological corridors and positively influencing the local climate. Thus, the historical development is in line with the contemporary postulates of climate resilient cities.
Metrics to Accelerate Private Sector Investment in Sustainable Development Goal 2—Zero Hunger
Authors: Brown Molly E.
Published: May 2021

Substantial investment from both the private and public sectors will be needed to achieve the ambitious Sustainable Development Goal 2 (SDG2), which focuses on ending poverty and achieving zero hunger. To harness the private sector, high quality, transparent metrics are needed to ensure that every dollar spent reaches the most marginalized segments of a community while still helping institutions achieve their goals. Satellite-derived Earth observations will be instrumental in accelerating these investments and targeting them to the regions with the greatest need. This article proposes two quantitative metrics that could be used to evaluate the impact of private sector activities on SDG2: measuring increases in yield over baseline and ensuring input availability and affordability in all markets.
Durability Performance Evaluation of Rubberized Geopolymer Concrete
Authors: Luhar Salmabanu , Luhar Ismail , Nicolaides Demetris , Gupta Rajesh
Published: May 2021

Unfortunately, the production of cement impacts pessimistically on environments since it emits CO2—a principal Green House Gas (GHG)—encouraging the earth-heating dilemma. Moreover, it necessitates not only high temperature produced by the devouring of narrow natural mineral coal resources to obtain very high amounts of energy, but it also gulps down natural limestone deposits as a raw material that is found confined in nature to obtain intense energy. Quite recently, geopolymerisation—an exothermic process, through which geopolymeric binders can be produced by synthesis of a pozzolanic precursor rich in Alumina and Silica, for an instant, Fly Ash, with alkali solution for activation in an alkali medium at a low temperature and low operational energy—is recognized as a brilliantly promising alternative to conventional cement. That means, no elevated temperature and higher energy consuming reactions are essential any more as found associated with contemporary cement production. This research paper moves towards fulfilling the performance evaluation of durability studies viz., water permeability, sorptivity, sulphate resistance, acid resistance, salt resistance, chloride diffusion, drying shrinkage, and corrosion of fly ash based user and eco-friendly rubberized (containing rubber tyre fibres) geopolymer concrete. Comparisons of the outcomes have been made with its counterpart, which has unearthed that Rubberized Geopolymer Concrete proved to better concerning all the above-mentioned parameters than Rubberized OPC-Concrete.
Monitoring Persistence Change in Heavy-Tailed Observations
Authors: Wang Dan
Published: May 2021

In this paper, a ratio test based on bootstrap approximation is proposed to detect the persistence change in heavy-tailed observations. This paper focuses on the symmetry testing problems of I(1)-to-I(0) and I(0)-to-I(1). On the basis of residual CUSUM, the test statistic is constructed in a ratio form. I prove the null distribution of the test statistic. The consistency under alternative hypothesis is also discussed. However, the null distribution of the test statistic contains an unknown tail index. To address this challenge, I present a bootstrap approximation method for determining the rejection region of this test. Simulation studies of artificial data are conducted to assess the finite sample performance, which shows that our method is better than the kernel method in all listed cases. The analysis of real data also demonstrates the excellent performance of this method.
A Fused Variable by Night Light Images and MODIS Products for Improving Urban Built-Up Area Extraction
Authors: Yang Guang , Ma Yuntao , Hu Jiaqi
Published: May 2021

The boundary of urban built-up areas is the baseline data of a city. Rapid and accurate monitoring of urban built-up areas is the prerequisite for the boundary control and the layout of urban spaces. In recent years, the night light satellite sensors have been employed in urban built-up area extraction. However, the existing extraction methods have not fully considered the properties that directly reflect the urban built-up areas, like the land surface temperature. This research first converted multi-source data into a uniform projection, geographic coordinate system and resampling size. Then, a fused variable that integrated the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) night light images, the Moderate-resolution Imaging Spectroradiometer (MODIS) surface temperature product and the normalized difference vegetation index (NDVI) product was designed to extract the built-up areas. The fusion results showed that the values of the proposed index presented a sharper gradient within a smaller spatial range, compared with the only night light images. The extraction results were tested in both the area sizes and the spatial locations. The proposed index performed better in both accuracies (average error rate 1.10%) and visual perspective. We further discussed the regularity of the optimal thresholds in the final boundary determination. The optimal thresholds of the proposed index were more stable in different cases on the premise of higher accuracies.
Novel Acinetobacter baumannii Myovirus TaPaz Encoding Two Tailspike Depolymerases: Characterization and Host-Recognition Strategy
Authors: Shchurova Anastasia S. , Shneider Mikhail M. , Arbatsky Nikolay P. , Shashkov Alexander S. , Chizhov Alexander O. , Skryabin Yuriy P. , Mikhaylova Yulia V. , Sokolova Olga S. , Shelenkov Andrey A. , Miroshnikov Konstantin A. , Knirel Yuriy A. , Popova Anastasia V.
Published: May 2021

Acinetobacter baumannii, one of the most significant nosocomial pathogens, is capable of producing structurally diverse capsular polysaccharides (CPSs) which are the primary receptors for A. baumannii bacteriophages encoding polysaccharide-degrading enzymes. To date, bacterial viruses specifically infecting A. baumannii strains belonging to more than ten various capsular types (K types) were isolated and characterized. In the present study, we investigate the biological properties, genomic organization, and virus–bacterial host interaction strategy of novel myovirus TaPaz isolated on the bacterial lawn of A. baumannii strain with a K47 capsular polysaccharide structure. The phage linear double-stranded DNA genome of 93,703 bp contains 178 open reading frames. Genes encoding two different tailspike depolymerases (TSDs) were identified in the phage genome. Recombinant TSDs were purified and tested against the collection of A. baumannii strains belonging to 56 different K types. One of the TSDs was demonstrated to be a specific glycosidase that cleaves the K47 CPS by the hydrolytic mechanism.
Spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical subsystem for final approach
Authors: ORLOVSKIY Igor V. , MIKHAILOV Mikhail V. , ROZHKOV Sergey N. , AVANESOV Genrikh A. , ZHUKOV Boris S.
Published: May 2021

The paper discusses an integrated system for spacecraft rendezvous and docking using measurements from satellite navigation equipment combined with the optical final approach subsystem (OFAS) which generates high-precision relative position vector during final approach It addresses issues involved in designing an OFAS which has to operate in an environment exposed to sunlight and provides an estimate for the accuracy of the relative position measurements depending on the current range and OFAS configuration. Simulations have been run of the final approach involving simultaneous control for m the satellite navigation equipment and OFAS. It was shown that at the moment of initial contact the approach accuracy of 2–5 cm for relative position, and of 1 cm/s for velocity is achieved.
Key words: spacecraft, navigation, rendezvous, docking, final approach, satellite navigation, optical sensor, TV camera, control, precision.
On the feasibility of developing a single- stage acceleration/deceleration unit based on the oxygen-hydrocarbon engine 11D58M for a super-heavy launch vehicle
Authors:   RSC Energia, SOKOLOV Boris , TUPITSYN Nikolay , TUMANIN Evgeniy , KRYUKOV Igor , KISELEV Andrey , FIRSTAEV Dmitry
Published: May 2021

The paper presents results of unsolicited exploratory design studies done by the authors into the feasibility of developing for a super-heavy launch vehicle a single-stage oxygen-hydrocarbon acceleration/deceleration unit (ADU) with two liquid-propellant rocket engines 11D58M developed by RSC Energia, intended for insertion of manned spacecraft into lunar orbit, as well as for insertion of super-heavy spacecraft into geostationary orbit (including the orbital module high-apogee transfer profile using lunar gravity assist maneuver). It demonstrates that the single-stage ADU will have a number of important advantages over both a single-stage oxygen-hydrogen ADU and a functionally similar two-stage acceleration/deceleration system of an orbital module in the form of a tandem stack of an oxygen-hydrogen acceleration stage and correction and braking stage. To assure the start-ups of the main liquid propulsion system of the ADU, it proposes a new method for inertial propellant component phase separation in the tanks in zero-gravity environment using a pre-startup pre-programmed ullage separation turn maneuver of the orbital unit about its transverse axis of inertia.
Conceptual design studies of an electrically propelled upper stage for deployment of a multi-plane orbital constellation of small spacecraft
Authors: LEVANDOVICH Aleksandr V. , MOSIN Dmitry A. , SINYAVSKIY Viktor V. , TYUTYUKIN Aleksandr Ye. , UPTMINTSEV Igor A.
Published: May 2021

The paper presents results of conceptual design studies to determine configuration of an electrically propelled upper stage (EPUS) – a space transportation stage (a space tug) with main engines based on electric propulsion powered by solar arrays. It addresses the problem of deploying a multi-plane orbital constellation of small spacecraft (SSC) using an electrically propelled upper stage. It proposes to change the SSC operational orbital planes based on the effect of the difference in precession rates between the parking and the working orbits owing to the effect of eccentricity in the Earth gravitational field. Requirements have been defined for the EPUS electrical propulsion system that take into account the need to operate it to offset the aerodynamic drag while waiting in the parking orbit for the SSC operational orbital plane to turn.
It demonstrates the feasibility of employing four EPUS that use Stationary Plasma Thruster-type electric propulsion as their main engines and gallium arsenide solar arrays for deployment in a 600 km orbit in four planes an orbital constellation of 24 small spacecraft with a mass of ~250 kg each using one launch of a medium capacity launch vehicle of Soyuz-2.1b type.
Key words: Electrically propelled upper stage, electric propulsion, small spacecraft, orbital constellation.
FACTORS PREDICTING INDIVIDUAL HEALTH BEHAVIORS DURING COVID-19 PANDEMIC
Authors: Van Chan Huynh , Mai Lan Nguyen Thi , Dung Vu , Minh Thuan Le , Thu Trang Vu , Thi Thanh Nga Nguyen , Nhan Ai Nguyen , Thuy Hao Ngo , Thi Dieu Linh Dao , Xuan Long Nguyen , Thanh Ha Le , Minh Nguyet Le , Xuan Hieu Ngo , Minh Long Dau , Ha Le Vu
Published: May 2021

Background: Covid - 19 is a global pandemic, affecting all areas of social life in every country. In the current conditions of the Covid-19 pandemic, individual health behaviors are of primary importance. Each citizen consciously implements their health behaviors not only to prevent them from being infected but also to help the country's prevention of Covid-19 effective. The study of factors predicting people’s health behaviors in the community will help managers come up with appropriate measures to improve public health and to quickly repel the pandemic.

Objectives: The research analyzes factors predicting personal health behaviors during the Covid-19 pandemic in Vietnam, including: pandemic awareness, self-assessment of the possibility of becoming infected, fear of disease, quality of life, and mental health (anxiety).

Methods:  This was a cross-sectional quantitative study. Data were collected from a convenient sample of 572 people in Vietnam (118 males, 451 females; M age =27.0 (sd = 10.0) ) by a means of an online questionnaire survey. The questionnaire was constructed based on the YouGov Behavior Change questionnaire; the Fear of Coronavirus-19 Scale (FCV-19), WHOQOL-BREF, the Moral Foundation Questionnaire, and Knowledge of Covid-19. This study performed multivariate regression analysis to explore effects of moral, quality of life, knowledge and fear of Coronavirus-19 on health behaviors of participants.

Result: The result showed that fear and sex factors explain 4% (R2-adj = 4%) of health behavior change in the Covid-19 pandemic. In addition, there is a signìicant relationship between health behaviors and fear, age, gender, and occupation.

Conclusion: People's health behaviors are particularly concerned during the Covid-19 pandemic. Community healthcare activities for the people should be tailored to suit different population groups such as gender, age or emotional experiences. More in-depth studies are needed to find out the causes of these differences, thereby proposing practical solutions to help people practice more effective health behaviors, contributing to preventing and combating the outbreak.