bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial Peptides-Coated Stainless Steel for Fighting Biofilms Formation for Food and Medical Fields: Review of Literature
Authors: Hage Mayssane , Akoum Hikmat , Chihib Nour-Eddine , Jama Charafeddine
Published: October 2021

Emerging technology regarding antimicrobial coatings contributes to fighting the challenge of pathogenic bacterial biofilms in medical and agri-food environments. Stainless steel is a material widely used in those fields since it has satisfying mechanical properties, but it, unfortunately, lacks the required bio-functionality, rendering it vulnerable to bacterial adhesion and biofilm formation. Therefore, this review aims to present the coatings developed by employing biocides grafted on stainless steel. It also highlights antimicrobial peptides (AMPs)used to coat stainless steel, particularly nisin, which is commonly accepted as a safe alternative to prevent pathogenic biofilm development.
Vapour Phase Deposition of Thin Siloxane Coatings on the Iron Surface. The Impact of the Layer Structure and Oxygen Adsorption on Corrosion Stability
Authors: Nazarov Andrei , Petrunin Maxim , Maksaeva Liudmila , Yurasova Tatyana , Traverso Pierluigi , Marshakov Andrey
Published: October 2021

The mechanism of iron corrosion protection by thin siloxane films was clarified. Quartz crystal microbalance technique (QCM) was applied to control the vapour phase deposition of alkoxysilanes and the formation of thin siloxane films. It was shown that the addition of water vapour increased the thickness of the grafted siloxane films. Crystal-like films spontaneously grow to 10–16 monolayers at 100% RH of Ar flow due to the catalytic effect of the surface. X-ray photoelectron (XPS) and Auger spectroscopies analysed the thin siloxane films and Scanning Kelvin Probe (SKP) showed the formation of iron-siloxane bonds passivating the iron surface. The films showed high hydrophobicity and corrosion inhibition in humid air contaminated by sulphur dioxide. Thick films were less ordered, hydrophilic and accelerated the corrosion of iron. For corrosion protection, the presence of oxygen in the atmosphere is extremely important. In a wet Ar atmosphere, contaminated by sulphur dioxide, the surfaces are not stable and quickly corroded. Oxygen adsorption stabilizes the surface oxide film that correspondingly preserves the anchoring iron-siloxane bonds and enables corrosion protection by the coating.
Analysis of Microstructure and Mechanical Properties in As-Built/As-Cast and Heat-Treated Conditions for IN718 Alloy Obtained by Selective Laser Melting and Investment Casting Processes
Authors: Pereira Juan Carlos , Aranzabe Jon , Taboada Mari Carmen , Ruiz Noelia , Rodriguez Pedro Pablo
Published: October 2021

In this work, new customized heat treatments for selective laser melted (SLM) parts in IN718 alloy were analyzed. This was done through the evaluation of the mechanical properties and advanced characterization of the phases and microstructure obtained in as-built condition and after the application of standard and tailored heat treatments. The microstructure and mechanical properties were compared and discussed with results reported in the literature. Finally, strengthening mechanisms of IN718 alloy processed by SLM and its differences with mechanisms that occur in investment casting were analyzed. Both processes generate quite different microstructures, investment casting is composed mainly by a dendritic structure, and SLM is characterized by columnar and cellular structures with very thin cells. Due to the fine and homogeneous microstructure obtained from SLM processing and its specific strengthening mechanisms, it is not necessary to apply homogenization and solution stages as in standard heat treatment used for this type of alloy in casting or wrought. The pre-heating and process parameters selected, in combination with a direct stepped aging (at 720 °C/620 °C), provide the material with its best mechanical properties, which are superior to those obtained by standard heat treatment (AMS 5383F) applied to investment casting of IN718 alloy.
Whole-Genome Sequencing Analysis of a stx-Negative Escherichia coli O63:H6 Isolate Associated with Hemolytic Uremic Syndrome
Authors: Kim Tae Yeul , La Tae-Min , Kim Taesoo , Yun Sun Ae , Lee Sang-Won , Huh Hee Jae , Lee Nam Yong
Published: October 2021

Shiga toxin-encoding genes (stx) of enterohemorrhagic Escherichia coli (EHEC) can be lost during infection or in vitro cultivation, and in clinical practice, it is difficult to distinguish EHEC that have lost stx (EHEC-LST) from enteropathogenic E. coli (EPEC), as both are stx-negative and eae-positive. In this study, we performed whole-genome sequencing (WGS) of a stx-negative, eae-positive E. coli O63:H6 isolate from a child with hemolytic uremic syndrome and compared its genome with those of nine E. coli O63:H6 strains in public databases. Virulence gene profiles were analyzed and core-genome multilocus sequence typing (cgMLST) was conducted. The virulence gene profile of our isolate was consistent with EHEC, except for the absence of stx, and the isolate clustered with seven EHEC strains but was distant from two EPEC strains in cgMLST. In genome alignment, our isolate exhibited a high nucleotide identity with EHEC strain 377323_2f but displayed a gap corresponding to the stx-harboring prophage sequence. Overall, our isolate was genetically closely related to EHEC strains, consistent with this being an EHEC-LST strain. As EHEC-LST may be misdiagnosed as EPEC in routine laboratories, comparative genomic analysis using WGS can be useful to determine whether stx-negative and eae-positive isolates are EHEC-LST or EPEC.
Ωto_abR: A Web Application for the Visualization and Analysis of Click-Evoked Auditory Brainstem Responses
Authors: Ballas Aristotelis , Katrakazas Panagiotis
Published: October 2021

Since its inception by Jewett and Williston in the late 1960s, the auditory brainstem response (ABR) has been an indispensable diagnostic tool, used by audiologists around the world. Click-evoked ABR testing proves to be a reliable tool, as it provides an objective representation of the auditory function, an estimate of hearing thresholds and the ability to pinpoint a potential issue in the auditory neural pathway. The present study describes state-of-the-art ABR analytics-related platforms and provides an overview of their functionality. In conjunction, we introduce the design and development of a newly developed, user-friendly web application, built in R language. This application provides several well-known and newly key characteristics for the analysis of ABR waveforms. These include absolute peak latencies, amplitudes, and interpeak latencies.
Impact of Bone Augmentation of Facial Bone Defect around Osseointegrated Implant: A Three Dimensional Finite Element Analysis
Authors: Hudieb Malik , AlKhader Mustafa , Mortaja Salah , Abusamak Mohammad , Wakabayashi Noriyuki , Kasugai Shohei
Published: October 2021

(1) Background: When dental implants are placed at the esthetic zone, facial bone fenestration might be expected. This study aimed to evaluate the biomechanical effect of bone augmentation around implants with facial bone fenestration defects using the finite element method. (2) Methods: An anterior maxillary region model with facial concavity was constructed with a threaded implant inserted following the root direction, resulting in apical threads exposure to represent the fenestration model. Several bone coverage levels were simulated by gradually shifting the deepest concavity point buccally, mimicking bone augmentation surgeries with different bone fill results. Oblique forces were applied, and analysis was performed. (3) Results: Peak compressive stress magnitude and distribution varied according to the level of exposure and facial concavity depth. The fenestration model demonstrated a slightly lower peak peri-implant bone stress, smaller implant displacement, and smaller bone volume with strain levels above 200 µ strain. A gradual increase in compressive stress, implant displacement, and bone volume exhibited strain level above 200 µ strain was observed with the increased bone fill level of the facial bone fenestration. (4) Conclusions: Exposure of implants apical threads at the maxillary anterior region does not significantly affect the peri-implant stress and strain results. However, increasing the buccolingual width and eliminating the buccal concavity might increase the peri-implant bone volume exhibited favorable loading levels.
Selection of the Optimal Number of Topics for LDA Topic Model—Taking Patent Policy Analysis as an Example
Authors: Gan Jingxian , Qi Yong
Published: October 2021

This study constructs a comprehensive index to effectively judge the optimal number of topics in the LDA topic model. Based on the requirements for selecting the number of topics, a comprehensive judgment index of perplexity, isolation, stability, and coincidence is constructed to select the number of topics. This method provides four advantages to selecting the optimal number of topics: (1) good predictive ability, (2) high isolation between topics, (3) no duplicate topics, and (4) repeatability. First, we use three general datasets to compare our proposed method with existing methods, and the results show that the optimal topic number selection method has better selection results. Then, we collected the patent policies of various provinces and cities in China (excluding Hong Kong, Macao, and Taiwan) as datasets. By using the optimal topic number selection method proposed in this study, we can classify patent policies well.
Revealing Impact Factors on Student Engagement: Learning Analytics Adoption in Online and Blended Courses in Higher Education
Authors: Fan Si , Chen Lihua , Nair Manoj , Garg Saurabh , Yeom Soonja , Kregor Gerry , Yang Yu , Wang Yanjun
Published: October 2021

This study aimed to identify factors influencing student engagement in online and blended courses at one Australian regional university. It applied a data science approach to learning and teaching data gathered from the learning management system used at this university. Data were collected and analysed from 23 subjects, spanning over 5500 student enrolments and 406 lecturer and tutor roles, over a five-year period. Based on a theoretical framework adapted from Community of Inquiry (CoI) framework by Garrison et al. (2000), the data were segregated into three groups for analysis: Student Engagement, Course Content and Teacher Input. The data analysis revealed a positive correlation between Student Engagement and Teacher Input, and interestingly, a negative correlation between Student Engagement and Course Content when a certain threshold was exceeded. The findings of the study offer useful suggestions for future course design, and pedagogical approaches teachers can adopt to foster student engagement.
Designing a Learning Progression about Micro-Evolution to Inform Instruction and Assessment in Elementary Science
Authors: Cardace Amy , Wilson Mark , Metz Kathleen E.
Published: October 2021

This paper gives an example of how to address the challenge of designing a learning progression that describes student thinking, with the necessary specificity to align instructional opportunities and assessment tools. We describe the Conceptual Underpinnings of Evolution project and the iterative process of developing a novel learning progression theory, while critically testing that theory using structured interview data analyzed with Rasch models. We investigate elementary students’ capacities for reasoning in biology, specifically focusing on microevolution as a strategic core idea for students between the ages of seven and nine. The learning progression theory informed the design of two instructional modules which aimed to build on students’ intuitions. The modules provided opportunities for students to engage in scientific practices framed to develop more adequate explanations about how organisms may change over time, in accordance with environmental changes. Aligning the learning progression, instructional activities, and structured interview assessment was critical for meeting two of our underlying assumptions: that students’ reasoning capacities rely on instructional opportunities; and that students’ assessment scores must be interpretable in terms of learning progression levels. We share both initial and late-stage versions of the learning progression and describe how item-level information and Rasch analyses helped both to specify the learning progression levels and to define the two underlying dimensions.
A Methodological Approach for Developing and Validating a Parsimonious and Robust Measurement Tool: The Academic E-Service Quality (ACEQUAL) Model
Authors: Lupo Toni , Buscarino Ester
Published: October 2021

Nowadays, in the higher education sector, the quality measurement process of education-related services is assuming a crucial role to support focused and targeted improvement activities deeply centered on students’ needs/necessities. These are considered crucial factors for dealing with the current academic competitive context. Therefore, the quality measurement process has to be precise and accurate, namely the measurement model on which it is based has to be parsimonious and robust. The present work proposes an effective and easy-to-use methodological approach suitable for supporting the structuring of a measurement tool. Its effectiveness is shown with reference to the academic e-service provided at the University of Palermo. In particular, taking into account the students’ viewpoints and perspectives, a measurement model of the academic e-service quality is developed and validated, thus overcoming the lack of literature on the subject. Finally, a survey is conducted, and highlighted academic e-service quality shortcomings and criticalities are stressed and discussed. The outcomes of this study may be of interest to practitioners and researchers in the field, offering important suggestions on how to support the structuring of a measurement model, as well the data-driven service quality improvement process.
A Remedial Control for Short-Circuit Fault in NPC/H-Bridge Inverters without Redundant Component
Authors: Ahmadi Sajjad , Poure Philippe , Khaburi Davood Arab , Saadate Shahrokh
Published: October 2021

In this paper, a five-level neutral-point-clamped (NPC) inverter with short-circuit fault-tolerant capability is presented. Based on the proposed approach, in order to ensure service continuity subsequent to a short-circuit fault event in a switch, two steps are carried out. First of all, destructive consequences arising from short-circuit fault in a power switch is prevented. Afterwards, according to the defected component, remedial actions are taken. The proposed strategy does not require any redundant component. The service continuity is acquired by applying a remedial control and modifying switching commands applied to the power switches. Using the proposed approach helps to restore the rated voltage and rated current at the terminal, and there is no limit for modulation index during fault-tolerant operation under remedial control. Furthermore, compared to healthy operation, harmonic content of the terminal voltage and current is not deteriorated during fault-tolerant operation. Moreover, additional components, such as bidirectional switches and contactors, are not employed in this strategy. Only some fast fuses are placed in the converter circuit for protection purposes which do not impose a noticeable cost compared to the bidirectional switches and contactors.
A Survey of Vision-Based Transfer Learning in Human Activity Recognition
Authors: Adama David Ada , Lotfi Ahmad , Ranson Robert
Published: October 2021

Human activity recognition (HAR) and transfer learning (TL) are two broad areas widely studied in computational intelligence (CI) and artificial intelligence (AI) applications. Much effort has been put into developing suitable solutions to advance the current performance of existing systems. However, challenges are facing the existing methods of HAR. In HAR, the variations in data required in HAR systems pose challenges to many existing solutions. The type of sensory information used could play an important role in overcoming some of these challenges. Vision-based information in 3D acquired using RGB-D cameras is one type. Furthermore, with the successes encountered in TL, HAR stands to benefit from TL to address challenges to existing methods. Therefore, it is important to review the current state-of-the-art related to both areas. This paper presents a comprehensive survey of vision-based HAR using different methods with a focus on the incorporation of TL in HAR methods. It also discusses the limitations, challenges and possible future directions for more research.
Research on Direct Power Control Strategy Based on Voltage Controlled Virtual Synchronous Generator
Authors: Xu Haizhen , Yu Changzhou , Mao Fubin , Hu Taotao , Wu Zelin , Wang Qinglong
Published: October 2021

To support the “carbon peak and carbon neutrality” goal, new energy is poised to explode, and new energy power generation converter is simultaneously facing new challenges. The conventional current-controlled new energy converter can quickly transmit active power on the DC bus to the power grid. However, for the weak grid, the stability margin of the converter grid-connected system is reduced on the one hand, which can easily cause resonance oscillation; on the other hand, the current controlled converter cannot actively respond to system frequency and voltage fluctuation to offer support. The voltage controlled virtual synchronous generator (VVSG) is used to improve system small signal stability and frequency stability; however, its power response speed is too slow to meet the requirements of fast following power command. Although a voltage/current dual-mode switching control scheme is put forward to achieve characteristics complementary of current controlled converter and voltage-controlled converter, the control structure switching and intermediate variable following is required to realize mode switching, which is prone to large power shocks and switching failures. In view of the problem, a direct power control strategy based on VVSG is proposed. The control structure is raised based on a conventional VVSG outer active power control loop, and the output active power and frequency characteristics are analyzed. Compared with the voltage and current dual-mode control, VVSG with direct power control can perform large inertia characteristic in the weak grid and fast power following characteristics in the strong grid by adjusting λ, and without control structure switching and intermediate variable following. Moreover, the two characteristics can be smoothly transited. In addition, the active support ability of voltage source can be maintained under both characteristics. Finally, the effectiveness of the proposed control strategy is verified through simulation results.
Meta-Heuristic Optimization Techniques Used for Maximum Power Point Tracking in Solar PV System
Authors: Verma Preeti , Alam Afroz , Sarwar Adil , Tariq Mohd , Vahedi Hani , Gupta Deeksha , Ahmad Shafiq , Shah Noor Mohamed Adamali
Published: October 2021

A critical advancement in solar photovoltaic (PV) establishment has led to robust acceleration towards the evolution of new MPPT techniques. The sun-oriented PV framework has a non-linear characteristic in varying climatic conditions, which considerably impact the PV framework yield. Furthermore, the partial shading condition (PSC) causes major problems, such as a drop in the output power yield and multiple peaks in the P–V attribute. Hence, following the global maximum power point (GMPP) under PSC is a demanding problem. Subsequently, different maximum power point tracking (MPPT) strategies have been utilized to improve the yield of a PV framework. However, the disarray lies in choosing the best MPPT technique from the wide algorithms for a particular purpose. Each algorithm has its benefits and drawbacks. Hence, there is a fundamental need for an appropriate audit of the MPPT strategies from time to time. This article presents new works done in the global power point tracking (GMPPT) algorithm field under the PSCs. It sums up different MPPT strategies alongside their working principle, mathematical representation, and flow charts. Moreover, tables depicted in this study briefly organize the significant attributes of algorithms. This work will serve as a reference for sorting an MPPT technique while designing PV systems.
Edge Container for Speech Recognition
Authors: Beňo Lukáš , Pribiš Rudolf , Drahoš Peter
Published: October 2021

Containerization has been mainly used in pure software solutions, but it is gradually finding its way into the industrial systems. This paper introduces the edge container with artificial intelligence for speech recognition, which performs the voice control function of the actuator as a part of the Human Machine Interface (HMI). This work proposes a procedure for creating voice-controlled applications with modern hardware and software resources. The created architecture integrates well-known digital technologies such as containerization, cloud, edge computing and a commercial voice processing tool. This methodology and architecture enable the actual speech recognition and the voice control on the edge device in the local network, rather than in the cloud, like the majority of recent solutions. The Linux containers are designed to run without any additional configuration and setup by the end user. A simple adaptation of voice commands via configuration file may be considered as an additional contribution of the work. The architecture was verified by experiments with running containers on different devices, such as PC, Tinker Board 2, Raspberry Pi 3 and 4. The proposed solution and the practical experiment show how a voice-controlled system can be created, easily managed and distributed to many devices around the world in a few seconds. All this can be achieved by simple downloading and running two types of ready-made containers without any complex installations. The result of this work is a proven stable (network-independent) solution with data protection and low latency.
Experimental Study on the Starting-Up and Heat Transfer Characteristics of a Pulsating Heat Pipe under Local Low-Frequency Vibrations
Authors: Chen Jing , Dong Junbiao , Yao Ye
Published: October 2021

Vibrations have attracted much attention as an effective method for enhancing heat transfer in pulsating heat pipes (PHPs). This study mainly investigates and explores the effects of local low-frequency vibrations on the starting-up and heat transfer characteristics of a PHP. The starting-up temperature and average temperatures along the evaporation section of the pulsating heat pipe were experimentally scrutinized, along with thermal performance, under local vibrations on evaporation, condensation and adiabatic sections, respectively. The following important conclusions can be derived by the experimental study: (1) The effect of vibrations at the evaporation section and at the adiabatic section during the starting-up time of the PHP were more significant than that at the condensation section; (2) vibrations at different positions could reduce the starting-up temperature of the PHP—the effect of the vibrations at the evaporation section was the best when heat power was lower, while the effect of vibrations on the adiabatic section was the best when heat power was higher; (3) vibrations at the evaporation and adiabatic sections could reduce the thermal resistance of the PHP, but vibrations at the condensation section had little effect on the thermal resistance of the PHP; (4) vibrations at the evaporation and adiabatic sections could effectively reduce the temperature at the evaporation section of the PHP, but the vibrations at the condensation section had no effect on the temperature at the evaporation section of the PHP. This paper shows that local low-frequency vibrations have positive effects on the heat transfer performances of PHPs.
Tree Regeneration by Seeds in Natural Forests
Authors: Šerá Božena
Published: October 2021

Seed quality and production are major factors governing the regeneration, structure, and succession of trees in natural forests [...]
Eastern Red Bat Responses to Fire during Winter Torpor
Authors: Layne Jason T. , Green Dana , Scesny Anna , Robbins Lynn W.
Published: October 2021

Prescribed fires are a forest management tool used to improve natural areas for a variety of benefits including increased plant diversity, reduced competition for desired species, decreased fuel loads, and improved wildlife habitat. The post-fire results in landscapes have shown positive benefits for bat populations. However, prescribed fires set in the winter may cause direct mortality of eastern red bat (Lasiurus borealis) populations that use leaf litter for roosting during periods of colder (<10 °C) temperatures. Therefore, we used controlled laboratory techniques to explore if eastern red bats arouse from torpor when exposed to cues associated with fire (i.e., smoke and the sound of fire). Through subsequent field trials, we confirmed latencies of first response (i.e., movement or increased respiration), arousal, and flight behaviors to the stimuli of fire. We provide evidence of smoke influencing eastern red bat first response and arousal through laboratory and field trial results. Latencies of all behaviors were negatively correlated with temperatures and wind speeds prior to and during field trials. We recommend prescribing winter fires on days when temperatures are >10 °C to provide eastern red bats with a better chance to passively rewarm and react to an approaching fire.
Variation in Downed Deadwood Density, Biomass, and Moisture during Decomposition in a Natural Temperate Forest
Authors: Přívětivý Tomáš , Šamonil Pavel
Published: October 2021

Deadwood is a resource of water, nutrients, and carbon, as well as an important driving factor of spatial pedocomplexity and hillslope processes in forested landscapes. The applicability of existing relevant studies in mountain forests in Central Europe is limited by the low number of data, absence of precise dating, and short time periods studied. Here, we aimed to assess the decomposition pathway in terms of changes and variability in the physical characteristics of deadwood (wood density, biomass, and moisture) during the decomposition process, and to describe differences in decomposition rate. The research was carried out in the Žofínský Primeval Forest, one of the oldest forest reserves in Europe. Samples were taken from sapwood of downed logs of the three main tree species: Fagus sylvatica L., Abies alba Mill., and Picea abies (L.) Karst. The time since the death of each downed log was obtained using tree censuses repeated since 1975 and dendrochronology. The maximal time since the death of a log was species-specific, and ranged from 61–76 years. The rate of change (slope) of moisture content along the time since death in a linear regression model was the highest for F. sylvatica (b = 3.94) compared to A. alba (b = 2.21) and P. abies (b = 1.93). An exponential model showing the dependence of biomass loss on time since death revealed that F. sylvatica stems with a diameter of 50–90 cm had the shortest decomposition rate—51 years—followed by P. abies (71 years) and A. alba (72 years). Our findings can be used in geochemical models of element cycles in temperate old-growth forests, the prediction of deadwood dynamics and changes in related biodiversity, and in refining management recommendations.
Differential Impact of an Eclipse on Photosynthetic Performance of Trees with Different Degrees of Shade Tolerance
Authors: Molina-Montenegro Marco A. , Atala Cristian , Carrasco-Urra Fernando
Published: October 2021

Solar eclipses represent a natural and unexpected event for plants that can potentially affect photosynthetic performance at the individual level. This effect, however, has seldom been evaluated. Here, we measured the impact of a total solar eclipse on the photosynthetic rate of different tree species—located in the Bosque Fray Jorge National Park, Chile—with varying degrees of shade tolerance. Specifically, we assessed whether the rapid and progressive light limitation facilitated by a solar eclipse would negatively impact the photosynthetic responses of these tree species and whether their photosynthetic performance would have a greater decrease when the percentage of eclipse shadow was higher, particularly in the less shade-tolerant species. To accomplish this, we compared daily changes in the photosynthetic rates of three tree species during a control (non-eclipse) vs. an eclipse day that occurred on 2 July 2019. Overall, tree species showed differences between a non-eclipse and eclipse day in the daily dynamics of their photosynthetic performance, with this trend being most evident at the peak of the solar eclipse. Additionally, each species showed a different pattern of de-epoxidation in accordance with its degree of shade tolerance. Our results suggest that solar eclipses negatively affect the photosynthesis of the studied Chilean tree species, which may be related to energy dissipation capacity via the de-epoxidation of xanthophyll pigments. This effect was more evident in shade-intolerant species, indicating that eclipses can present different consequences for the overall performance of various plant species.
Rheological and Functional Properties of Hydrocolloids from Pereskia bleo Leaves
Authors: López-Barraza Diana , Ortega-Ramos Andres , Torregroza-Fuentes Edilbert , Quintana Somaris E. , García-Zapateiro Luis A.
Published: October 2021

The food industry has increased its interest in using natural and consumer-friendly ingredients to produce food products. In the case of hydrocolloids of natural origin, the materials are biodegradable and environmentally friendly. This study aimed to isolate hydrocolloids from Pereskia bleo leaves and evaluate their proximal composition, technological and rheological properties. High-carbohydrate Pereskia bleo with high water holding capacity and emulsifying stability were obtained. The samples showed a shear-thinning behavior adjusted to the Cross model (R2 > 0.93) and a high dependence on temperature corroborating with the higher activation energy value (11.78 kJ/mol, R2 = 0.99) as an indicator of a rapid change in viscosity and microstructure. The viscoelastic properties are shown with a storage modulus higher than the loss modulus, presenting a gel structure. The isolation of hydrocolloids from leaves is a major challenge for commercializing natural ingredients with technological properties. Therefore, this study suggests that these hydrocolloids from Pereskia bleo leaves can be good ingredients in microstructure and texturizing products, improving the stability as thickener agents.
A Hybrid Parallel Numerical Model for Wave-Induced Free-Surface Flow
Authors: Leftheriotis Georgios A. , Chalmoukis Iason A. , Oyarzun Guillermo , Dimas Athanassios A.
Published: October 2021

An advanced numerical model is presented for the simulation of wave-induced free-surface flow, utilizing an efficient hybrid parallel implementation. The model is based on the solution of the Navier–Stokes equations using large-eddy simulation of large-scale coastal free-surface flows. The three-dimensional immersed boundary method was used for the enforcement of the no-slip boundary condition on the bed surface. The water-air interface was tracked using the level-set method. The numerical model was effectively validated against laboratory measurements involving wave propagation over a flatbed with an elliptical shoal, whose presence induces combined wave refraction and diffraction phenomena. The parallel implementation of the model enabled the efficient simulation of depth-resolved, wave-induced, three-dimensional, free-surface flow; the model parallel efficiency and strong scaling are quantitatively demonstrated.
Current Status and Perspectives on the Application of CRISPR/Cas9 Gene-Editing System to Develop a Low-Gluten, Non-Transgenic Wheat Variety
Authors: Verma Anil K. , Mandal Sayanti , Tiwari Aadhya , Monachesi Chiara , Catassi Giulia N. , Srivastava Akash , Gatti Simona , Lionetti Elena , Catassi Carlo
Published: October 2021

Wheat gluten contains epitopes that trigger celiac disease (CD). A life-long strict gluten-free diet is the only treatment accepted for CD. However, very low-gluten wheat may provide an alternative treatment to CD. Conventional plant breeding methods have not been sufficient to produce celiac-safe wheat. RNA interference technology, to some extent, has succeeded in the development of safer wheat varieties. However, these varieties have multiple challenges in terms of their implementation. Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease 9 (CRISPR/Cas9) is a versatile gene-editing tool that has the ability to edit immunogenic gluten genes. So far, only a few studies have applied CRISPR/Cas9 to modify the wheat genome. In this article, we reviewed the published literature that applied CRISPR/Cas9 in wheat genome editing to investigate the current status of the CRISPR/Cas9 system to produce a low-immunogenic wheat variety. We found that in recent years, the CRISPR/Cas9 system has been continuously improved to edit the complex hexaploid wheat genome. Although some reduced immunogenic wheat varieties have been reported, CRISPR/Cas9 has still not been fully explored in terms of editing the wheat genome. We conclude that further studies are required to apply the CRISPR/Cas9 gene-editing system efficiently for the development of a celiac-safe wheat variety and to establish it as a “tool to celiac safe wheat”.
Monitoring of Food Waste Anaerobic Digestion Performance: Conventional Co-Substrates vs. Unmarketable Biochar Additions
Authors: Chaher Nour El Houda , Nassour Abdallah , Hamdi Moktar , Nelles Michael
Published: October 2021

This study proposed the selection of cost-effective additives generated from different activity sectors to enhance and stabilize the start-up, as well as the transitional phases, of semi-continuous food waste (FW) anaerobic digestion. The results showed that combining agricultural waste mixtures including wheat straw (WS) and cattle manure (CM) boosted the process performance and generated up to 95% higher methane yield compared to the control reactors (mono-digested FW) under an organic loading rate (OLR) range of 2 to 3 kg VS/m3·d. Whereas R3 amended with unmarketable biochar (UBc), to around 10% of the initial fresh mass inserted, showed a significant process enhancement during the transitional phase, and more particularly at an OLR of 4 kg VS/m3·d, it was revealed that under these experimental conditions, FW reactors including UBc showed an increase of 144% in terms of specific biogas yield (SBY) compared to FW reactors fed with agricultural residue. Hence, both agricultural and industrial waste were efficacious when it came to boosting either FW anaerobic performance or AD effluent quality. Although each co-substrate performed under specific experimental conditions, this feature provides decision makers with diverse alternatives to implement a sustainable organic waste management system, conveying sufficient technical details to draw up appropriate designs for the recovery of various types of organic residue.
Food Loss and Waste Actions: Experiences of the Costa Rican Food Loss and Waste Reduction Network
Authors: Bolaños-Palmieri Carolina , Jiménez-Morales María Fernanda , Rojas-Vargas Julián , Arguedas-Camacho Manrique , Brenes-Peralta Laura
Published: October 2021

Food Loss and Waste (FLW) reduction and prevention can be crucial entry points to achieve sustainable food systems. However, the complexity of this problem poses the need for multistakeholder and multidimensional approaches. The Costa Rican FLW Reduction Network has been working since 2014 as a collaborative platform that brings together different sectors and disciplines to promote a change through communication and awareness, alliances, and research and innovation. The purpose of our study was to share the experience of Costa Rica in regards to the applied FLW actions and its catalytic effect on FLW innovation. The study was developed through a multimethod approach that included case studies, stakeholder analysis and literacy analysis to provide an overall assessment of the strategy as input for further efforts in this matter. The main findings indicate that collaborative actions among institutions and sectors are vital in promoting FLW reduction; however, FLW innovation is still at an inception phase where financial resources and policy barriers remain as aspects to address. In conclusion, the Costa Rica FLW Network represents an asset to trigger ongoing and future actions, and approaches like an integrated innovation ecosystem must be promoted.
Effect of Freeze-Thaw Cycles on Juice Properties, Volatile Compounds and Hot-Air Drying Kinetics of Blueberry
Authors: Zhu Lin , Liang Xianrui , Lu Yushuang , Tian Shiyi , Chen Jie , Lin Fubin , Fang Sheng
Published: October 2021

This paper studied the effects of freeze-thaw (FT) cycles on the juice properties and aroma profiles, and the hot-air drying kinetics of frozen blueberry. After FT treatment, the juice yield increased while pH and total soluble solids of the juice keep unchanged. The total anthocyanins contents and DPPH antioxidant activities of the juice decreased by FT treatments. The electronic nose shows that FT treatments significantly change the aroma profiles of the juice. The four main volatile substances in the fresh juice are (E)-2-hexenal, α-terpineol, hexanal and linalyl formate, which account for 48.5 ± 0.1%, 17.6 ± 0.2%, 14.0 ± 1.5% and 7.8 ± 2.7% of relative proportions based on total ion chromatogram (TIC) peak areas. In the FT-treated samples, the amount of (E)-2-hexenal and hexanal decreased significantly while α-terpineol and linalyl formate remained almost unchanged. Repeated FT cycles increased the ethanol content and destroyed the original green leafy flavor. Finally, the drying kinetics of FT-treated blueberries was tested. One FT treatment can shorten the drying time by about 30% to achieve the same water content. The Deff values of the FT-treated sample are similar, which are about twice as large as the value of the fresh sample. The results will be beneficial for the processing of frozen blueberry into juice or dried fruits.
Micromorphological Study of Site Formation Processes at El Sidrón Cave (Asturias, Northern Spain): Encrustations over Neanderthal Bones
Authors: Cañaveras Juan Carlos , Sánchez-Moral Sergio , Duarte Elsa , Santos-Delgado Gabriel , Silva Pablo G. , Cuezva Soledad , Fernández-Cortés Ángel , Lario Javier , Muñoz-Cervera María Concepción , Rasilla Marco de la
Published: October 2021

El Sidrón Cave is an archaeological and anthropological reference site of the Neanderthal world. It shows singular activity related to cannibalisation, and all existing processes are relevant to explain the specific behaviour of the concerned individuals. This paper presents geoarchaeological data, primarily based on mineralogical and petrographic techniques, from an investigation of the nature of the encrustations or hard coatings that affect a large part of the Neanderthal bone remains and their relationship with the depositional and post-depositional processes at the archaeological site. Crusts and patina were found to be numerous and diverse, mainly composed of calcite and siliciclastic grains, with different proportions and textures. The analysis indicated different origins and scenarios from their initial post-mortem accumulation to the final deposit recovered during the archaeological work. The presence of micromorphological features, such as clotted-peloidal micrite, needle-fibre calcite (NFC) aggregates, clay coatings, iron–manganese impregnation, and/or adhered aeolian dust may indicate that a significant proportion of the remains were affected by subaerial conditions in a relatively short period of time in a shelter, cave entrance, or shallower level of the karstic system, prior to their accumulation in the Ossuary Gallery.
A Protocol for a Systematic Review and Meta-Analysis of Mind–Body Modalities to Manage the Mental Health of Healthcare Workers during the COVID-19 Era
Authors: Kwon Chan-Young , Lee Boram
Published: October 2021

The coronavirus disease 2019 (COVID-19) pandemic has become an unprecedented threat to humanity worldwide, including healthcare workers (HCWs). Mind–body modalities have been used to improve the mental health, well-being, quality of life, and physical health of clinical and general populations, and may also be used to improve the mental health of HCWs during COVID-19. The objective of this review is to analyze the effectiveness of mind–body modalities for the mental health of HCWs in the COVID-19 era. Six electronic bibliographic databases were comprehensively searched to find intervention studies using mind–body modalities, including meditation, mindfulness-based intervention, autogenic training, yoga, tai chi, qigong, breathing exercise, music therapy, guided imagery, biofeedback, prayer, and faith-based techniques for HCWs. All intervention studies conducted from December 2019 to August 2021 will be included. Quality assessment will be performed according to study type, and Cochrane Collaboration’s Risk of Bias tool will be used for randomized controlled clinical trials (RCTs). If sufficient homogeneous data from RCTs exist, a meta-analysis will be performed. Dichotomous data and continuous data are presented as risk ratios and mean differences with their 95% confidence intervals, respectively. The results of this systematic review will be disseminated through the publication of a manuscript in a peer-reviewed journal or by presentation at a conference.
Pharmacy Student Challenges and Strategies towards Initial COVID-19 Curriculum Changes
Authors: Liu Luyao , Caliph Suzanne , Simpson Claire , Khoo Ruohern Zoe , Neviles Geenath , Muthumuni Sithira , Lyons Kayley M.
Published: October 2021

Due to COVID-19, tertiary institutions were forced to deliver knowledge virtually, which proposed challenges for both institutions and students. In this study, we aimed to characterize pharmacy students’ challenges and strategies during COVID-19 curriculum changes, therefore developing a comprehensive understanding of students’ learning, wellbeing, and resilience in the ever-changing situation. Data were collected from student written reflections across four year levels at one school of pharmacy from March–May 2020. In addition, data were collected from written responses of second-year pharmacy students responding to prompted questions. The data were qualitatively analyzed inductively by five coders using NVivo 12. For each piece of data, two coders independently coded the data, calculated the inter-rater agreement, and resolved discrepancies. The most coded challenges were ‘negative emotional response’ and ‘communication barrier during virtual learning’. The most coded strategies were ‘using new technology’ and ‘time management’. This study allows researchers and education institutions to gain an overview of pharmacy students’ experiences during COVID-19, therefore helping universities to provide students with necessary support and techniques on how to self-cope with COVID-19 as well as stressful events in the future.
Development and Validation of the Nursing Students’ Rights Awareness Scale in Clinical Practice: A Scale Development Study
Authors: Park Sung-Hee , Choi Mi-Young
Published: October 2021

Nursing students perform clinical training in a variety of clinical practice fields, so their rights are important. Efforts are needed to accurately identify and measure the awareness of nursing students’ rights. This study aimed to develop and evaluate the psychometric properties of nursing students’ rights awareness scale. The study procedure was carried out in four stages: the concept analysis, item development, scale development, and scale evaluation stage. First, in the concept analysis stage, the attributes of the concept were derived. Second, in the item development stage, preliminary items were derived, and the content validity was verified. Third, in the scale development stage, a preliminary and main survey were conducted, and item reduction was implemented. Fourth, in the scale evaluation stage, construct validity and reliability were verified. The collected data were analyzed using the SPSS 24.0, and item analysis was conducted using skewness, kurtosis, and item-total correlation scores. The construct validity was assessed by exploratory factor analysis, convergent validity, and divergent validity. The reliability was analyzed using Cronbach’s alpha coefficient and composite reliability. The final version of the scale was tested on 240 nursing students from three cities in South Korea. From the construct validity, three factors and 14 items were selected. The factors included “the rights to be protected, cared for, supported, and respected” (eight items), “the rights to be recognized as a member of a nursing team” (three items), and “the rights to learn” (three questions). The reliability of the scale was also verified. Through this study, the scale was developed to identify the rights of nursing students in clinical practice. The implication of this study is that it has laid the foundation for measuring the rights of nursing students applicable in clinical settings for the first time. The limitation of this study is that data were collected in some regions. Therefore, it is necessary to verify the validity and reliability of the scale in various cultures.
Novel S. pennellii × S. lycopersicum Hybrid Rootstocks for Tomato Production with Reduced Water and Nutrient Supply
Authors: Ellenberger Jan , Bulut Aylin , Blömeke Philip , Röhlen-Schmittgen Simone
Published: October 2021

Drought stress and nutrient deficiency are limiting factors in vegetable production that will have a decisive role due to the challenges of climate change in the future. The negative effects of these stressors on yield can be mitigated by crop grafting. The increasing demands for resource-use efficiency in crop production, therefore, require the development and phenotyping of more resilient rootstocks, and the selection of appropriate scions. We tested the effect of combined drought stress and nutrient deficiency on yield and fruit quality of the two tomato cultivars ‘Lyterno’ and ‘Tastery’ in the greenhouse, grafted onto different rootstock genotypes. The use of four different rootstocks, including two novel S. pennellii × S. lycopersicum hybrids and the proven-effective use of ‘Beaufort’, as well as self-grafted plants, allowed conclusions to be drawn about the differential stress mitigation of the rootstocks used. The stress-induced yield reduction of the scion ‘Lyterno’ can be mitigated more significantly by the novel hybrid rootstocks than by the commercial rootstock ‘Beaufort’. At the same time, however, the individual fruit weight and the lycopene content of the fruits were significantly reduced when grafted onto the hybrid rootstocks. In contrast, the cultivar ‘Tastery’ showed a weak stress response, so that a generally positive influence of the rootstocks independently of the scions could not be demonstrated. We conclude that, particularly for more sensitive cultivars, the selection of more resilient rootstocks offers the potential for sustainable and resource-efficient production not competing with the overall quality of tomatoes.