bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Citizen Science Initiatives as a Springboard towards the Education for Environmental Citizenship: A Systematic Literature Review of Empirical Research
Authors: Adamou Anastasia , Georgiou Yiannis , Paraskeva-Hadjichambi Demetra , Hadjichambis Andreas Ch.
Published: December 2021

Environmental Citizen Science (CS) initiatives have been recognized over time as a promising way to engage citizens in the investigation and management of various socio-ecological issues. In this context, it has been often hypothesized that these CS initiatives may also contribute to the education and subsequent transformation of citizens into environmentally aware and active citizens. However, the potential of CS to serve as a springboard for supporting Education for Environmental Citizenship (EEC) has not been explored yet. A systematic review was conducted, seeking to examine how citizens’ participation in environmental CS initiatives contributes to the EEC, as a venue through which citizens can undertake actions in different scales (local, national, global) to achieve environmental citizenship. A content analysis procedure was implemented on thirty-one empirical studies (n = 31) retrieved from a systematic review of the literature covering the timespan of the last two decades (2000–2020), according to the PRISMA methodology. The findings indicated that the majority of the reviewed environmental CS initiatives primarily enhanced citizens’ skills and knowledge over the competences of attitudes, values, and behaviors. In addition, it was found that CS initiatives empowered primarily citizens’ personal and responsible environmental actions, which were situated in the private sphere and at the local scale. The derived environmental outcomes were mainly related to the solution and prevention of environmental problems. Finally, correlational statistical analysis indicated that there were strong correlations between the Environmental Citizenship (EC) competences, actions and EEC outcomes and unveiled a set of keystone components; namely, components of crucial significance in the field of EC. We reflect on these findings, and we discuss directions for future research.
Durable Steel-Reinforced Concrete Structures for Marine Environments
Authors: Melchers Robert E. , Chaves Igor A.
Published: December 2021

Even in harsh marine environments, concrete structures reinforced with steel can show excellent long-term durability, with little or no reinforcement corrosion. Very few actual reinforced concrete (RC) structures have been closely scrutinized over many years and subject to interpretation using recent state-of-the-art understanding gained from detailed laboratory observations. Such a case is described for an 80-year-old RC structure observed annually over about 30 years in what is essentially an extraordinary long experiment. Despite very high chloride concentrations, field excavation evidence showed that reinforcement corrosion overall remains minimal, except where insufficient concrete compaction permitted air-voids to initiate quite severe, very localized corrosion even with still high concrete pH. It is possible that the use of blast furnace slag as aggregate may have assisted the observed durability. The case study supports other studies that show that it is possible to achieve long-term durable and therefore sustainable RC structures without additives and using only conventional reinforcement steels and conventional cements and aggregates. However, the potential dangers of deep narrow cracking extending to the reinforcement and the potentially deleterious effects of alkali–aggregate reactivity of some aggregates needs to be considered.
Street Art Participation in Increasing Investments in the City Center of Bucharest, a Paradox or Not?
Authors: Cercleux Andreea-Loreta
Published: December 2021

This article analyses street art’s contribution to the current economic life in the city center of an Eastern European capital, Bucharest. The development of socio-economic activities in the Romanian capital has been strongly influenced in the last 30 years by a complex of effects generated by the transition to the capitalist economy in the early 1990s, the impact of globalization, and recently the COVID-19 pandemic. This study focuses on the investigation of those areas that through street art came to know processes of urban regeneration. By applying semi-structured interviews to providers of alternative guided tours, but also questionnaires among the population that is familiar with this subculture, including an organization of urban regeneration through street art, an important number of economically new spaces, next to reinvented ones, have been investigated. In these areas, street art ends up by supporting activities from hospitality, cultural, and creative industries, changing for the better the perspectives of economic and cultural development, along with the attractiveness of the Bucharest city center. Street art proves to be an important tool in the regeneration process bringing positive effects when involving active cooperation between the public and the private sectors.
The Mediating Role of HRM in the Relationship between CSR and Performance in the Hospitality Industry
Authors: Franzoni Simona , Sarwar Huma , Ishaq Muhammad Ishtiaq
Published: December 2021

In recent years, the concepts of human resource management (HRM) and corporate social responsibility (CSR) have gained significant focus across industries. The role and implications of CSR are vital for organizational success; similarly, HRM plays a vital role in understanding, developing, and implementing CSR strategies. Therefore, we claimed that the nexus of HRM and CSR is worthwhile to study and relevant in the current pandemic situation. Despite recent calls about the role of human resource management (HRM) and corporate social responsibility (CSR) in achieving sustainable performance, a few studies have investigated their role combinedly in the hospitality industry, especially in a cross-cultural context. Therefore, the present study addresses the current lack of comparative research about the impact of HRM and CSR on sustainable performance in the hospitality industry of Pakistan, the UK, and Italy and shows the mediating role of HRM in such a relationship. A quantitative methodology is applied to the survey of the employees from 354 Pakistani, 438 British, and 520 Italian hotels working in three-, four-, and five-star hotels. The results showed a positive correlation between CSR, HRM, and sustainable performance. Moreover, the results also indicated significant differences among the three countries analyzed concerning the mediating role of HRM in this relationship.
Video Platforms’ Value-Added Service Investments and Pricing Strategies for Advertisers
Authors: Liu Gang , An Fengyue
Published: December 2021

Using a game-theoretical approach, this paper develops a duopoly model and examines value-added service (VAS) investments and pricing strategies on video platforms with opposite inter-group network externalities between two groups. We consider two scenarios with VAS investment, namely, a single platform investing in VASs for advertisers (S-Model) and both platforms investing in VASs for advertisers (B-Model). We found the following: (i) In the S-Model, the investing platform’s VAS level remains maximum when the marginal investing cost is low; otherwise, it decreases with the cost. Investing and non-investing platforms’ advertising prices are unaffected by the marginal investing cost if the cost is low; otherwise, the prices decrease and increase with the cost, respectively. Furthermore, the investing platform’s advertising price is higher than the non-investing platform’s. (ii) In the B-Model, the two platforms’ VAS levels remain maximum if the marginal investing cost is low; otherwise, they decrease with the cost. The two platforms’ advertising prices are equal and irrelevant to the marginal investing cost. (iii) The investing platform’s VAS level in the S-Model is higher than or the same as that in the B-Model and the investing platform’s advertising price in the S-Model is higher than that in the B-Model. (iv) Compared to the scenario without VAS investment, the investing platform’s advertising price is higher in the S-Model, but the same in the B-Model.
Team Learning, Work Behaviors, and Performance: A Qualitative Case Study of a Technical University in Ghana
Authors: Atatsi Eli Ayawo , Stoffers Jol , Kil Ad
Published: December 2021

Higher education institutions in Ghana have a lot of expectations but appear to be facing contemporary challenges. Using five focus groups, this study explores individual learning, team learning, organizational citizenship behaviors, leader–member exchanges, innovative work behaviors, and performance in a Ghanaian technical university. Interactive exchanges suggest that individual social behaviors and leadership exchanges are important to higher educational institutions (HEIs). Both stakeholders and managers should activate these behaviors and leadership qualities to enhance performance. The inherent benefits help both faculty and HEIs fulfill their core mandates of teaching, research, and community service. With these, they remain globally competitive given challenges, dynamism, and expected performance from both faculty and HEIs as agents of socio-economic development. This study informs on underlying mechanisms that affect engagement in some of these behaviors, including the effect of culture as an inhibitor of women’s innovative behaviors. Next to that, it provides both theoretical and practical evidence for stakeholders, especially HEI managers, regarding how to increase faculty members’ efficiencies and performance. Finally, the study offers both recommendations and directions for future research.
External Thermal Insulation Composite Systems (ETICS) from Industry and Academia Perspective
Authors: Michalak Jacek
Published: December 2021

External Thermal Insulation Composite System (ETICS) is a commonly used solution in EU countries to increase building energy efficiency. The article describes ETICS in terms of environmental impact from two perspectives, i.e., industry and academia. In EU countries, ETICS manufacturers to place construction products to the market must subject it to the assessment and verification of constancy of performance (AVCP). The basis of this process is the European Technical Assessment (ETA). Based on the number of issued and valid ETAs for ETICS and the number of Environmental Product Declarations (EPDs), the dimension of sustainability issues was discussed. Analysis of one of the environmental indicators (Global Warming Potential—GWP) for ETICS with EPS, XPS, and MW showed only a general trend. However, there are significant differences between the values of the GWP and other environmental indicators that one can use for future AVCP of construction products. In the light of the research described in the paper, it seems reasonable to conclude that AVCP for ETICS in terms of sustainability will be challenging to implement in practice-based only on environmental indicators according to EN 15804. The article also reviews scientific publications on the sustainability of ETICS.
Comparative Study of Factors Contributing to Land Surface Temperature in High-Density Built Environments in Megacities Using Satellite Imagery
Authors: Zeng Frankie Fanjie , Feng Jiajun , Zhang Yuanzhi , Tsou Jin Yeu , Xue Tengfei , Li Yu , Li Rita Yi Man
Published: December 2021

In this study, the root sources contributing to the urban heat island (UHI) effect between megacities, such as Hong Kong and Shenzhen, were integrated and compared using satellite remote sensing data. Classification and multilayer perceptron regression tree (CARTMLP) algorithms were used to classify land use. The radiative transfer equation method was applied to retrieve the land surface temperatures (LSTs) in the study area. Multiple linear regression analysis was applied to determine the relationship between land-use types and UHIs. The experimental results show a large area of relatively high temperature dispersed within Shenzhen, and comparatively small areas highly centralized in Hong Kong, with the retrieved LST in Hong Kong lower than that in Shenzhen. In addition, the surface temperature of large complex buildings decorated with high-albedo materials in Hong Kong was higher than in Shenzhen (e.g., Hong Kong International Airport, 25.12 °C; Shenzhen Bao’an International Airport, 23.38 °C), with artificial heat being an important contributor to these differences. These results also imply that high-albedo materials are sufficient to alleviate high temperatures. These findings are integrated to propose an organic combination strategy for reducing UHI effects in urban areas in megacities worldwide, such as Hong Kong and Shenzhen in China.
Research on Ternary Interactive Gatekeeping Model for Multi-Channel Networks (MCNs) in Social Media Era
Authors: Xin Jie , Ni Wan , Yu Zhiyuan
Published: December 2021

In the digital content industry, the emerging multi-channel networks (MCNs) have dramatically changed the ways of content production and distribution in sustainable social media. As a result, it also brings an unprecedented impact and challenge to the traditional gatekeeping model, which play a vital role to describe and explain the reporting process regarding news events. In this paper, we propose a Ternary Interactive Gatekeeping (TIG) model and then discusse the gatekeeping behaviors of MCNs from the aspects of content production and distribution, which intend to integrate the roles of MCNs, content creators and social platforms all in one. In this way, MCNs are not only the intermediary, but also undertake the responsibility of gatekeeper in social media, which exerts the important role in online pseudo-environments. Semi-structured interviews are conducted with 15 interviewees that consist of the advertiser, creator, and staff in MCNs and platforms. For the content production, the gatekeeping behaviors of MCNs consist of selection, shaping and withholding. Those contents that satisfy the profits and development requirements of MCNs are chosen. For the content distribution, the gatekeeping behaviors of MCNs consist of display, timing and repetition, which aim to realize the high media exposure for Internet users. It can be seen that MCNs’ gatekeeping behaviors are affected by the business-logic. By the proposed gatekeeping scheme, we intend to provide a new perspective for future research on information management of social media.
The Inclusion of Resilience as an Element of the Sustainable Dimension in the LOMLOE Curriculum in a European Framework
Authors: Gavari-Starkie Elisa , Pastrana-Huguet Josep , Navarro-González Inmaculada , Espinosa-Gutiérrez Patricia-Teresa
Published: December 2021

This article provides the research community with a conceptual framework from a historical perspective of the impulse of education sustainability in the official international literature. In addition, the United Nations International Conferences held on Japanese territory in order to foster education for risk reduction and for training resilient individuals and communities are analyzed. The study of the content of both approaches, education for sustainability and education for risk reduction, constitute an innovative approach especially relevant after the pandemic caused by the COVID-19 crisis. The article advances with a historical analysis of the use of the concept of resilience in the European Institutions’ official documents. Our findings show that it is particular after 2015 when resilience is linked to sustainability. Before this, the European approach was mostly linked to food crises and emergencies. The article offers a synthesis of the global and European approaches in tables so that we can compare the progress in the United Nations discourse and the European Union one. In this conceptual framework, we offer a contribution to the debate for European national education systems. In particular, we offer contribute to the debate of the Organic Law LOMLOE approved in Spain in 2020, in which education for sustainability is strongly considered but not so much resilience education. The article intends to contribute to the inclusion of resilience as an element of the curriculum linked to the education for sustainability.
Sustained Change in ADHD: Interventions and Variables That Lead to Durable Improvements in Symptoms and Quality of Life
Authors: García Trinidad , Rodríguez Celestino
Published: December 2021

Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most common conditions in childhood, but it also persists into adolescence and adulthood, showing prevalence rates from 5 [...]
Understanding Job Stress and Organizational Effectiveness of Airline Employees Due to Changes in the Employment Environment under COVID-19—Focusing on the Difference in the GAD-7 of Employees
Authors: Shin Dong-Jin , Kim Yeon-Sun , Kim Bo-Kyeong
Published: December 2021

The purpose of this study was to examine the relationship between the job stress of employees due to changes in the employment environment of airlines under COVID-19 and job burnout and turnover intention. GAD-7 was applied to verify the influence relationship linking job stress, job burnout and turnover intention, using a structural equation model according to anxiety, namely, COVID blues. The results of this study can provide a theoretical basis for the relationship linking job stress, job burnout and turnover intention of employees due to changes in the employment environment resulting from the business crisis of airlines under the COVID-19 pandemic, which has been ongoing since 2020. In addition, it was possible to understand the degree of impact on stress, job burnout and turnover intention by measuring the anxiety disorder of employees, i.e., COVID-19 blues, due to the prolonged pandemic. This study provides basic data on human management measures in the aviation field. Furthermore, according to the results of this study, changes in the employment environment led to job stress in employees, which in turn increased employee job burnout and turnover intention. These results can provide practical implications and help human resource managers to better manage employees, as it was revealed that both changes in the organization of employees and changes in the employment environment of temporary employees increase job stress. Lastly, in the situation where COVID-19 and its associated blues continue, the GAD-7 scale, typically used for patients in hospitals, was applied to airline employees to determine their anxiety levels and psychological state, representing an effective method of lowering intention to leave, job stress and job burnout.
Key Determinants of Municipal Waste Sorting in Slovakia
Authors: Stričík Michal , Čonková Monika
Published: December 2021

The Slovak Republic does not meet the targets of the waste economy in the long run. In order to meet these objectives, it is necessary to make changes to the current system of municipal waste management. Building on an empirical analysis, this paper focuses on the evaluation of the production of municipal waste and the factors that influence the level of municipal waste sorting as a prerequisite for the maximal re-use, recovery, or recycling of municipal waste. The type of fee for municipal waste was confirmed as the most significant factor for the higher rate of municipal waste sorting, and pertinent recommendations were suggested according to the needs of Slovak municipalities.
The Effects of Flipped Learning Approaches in Anatomy Class
Authors: Hwang Younghui , Oh Jihyun
Published: December 2021

Pedagogical innovations applying flipped learning models are being applied in nursing education. The aim of this study was to verify the effects of the flipped learning approach in an anatomy class among undergraduate nursing students. This was a non-randomized controlled study. Of 154 nursing students enrolled in an anatomy class in South Korea, 79 were in the lecture-based group and 75 were in the flipped learning group. Data were collected using structured questionnaires. Problem solving ability and self-leadership improved significantly in the flipped learning group after the intervention but decreased in the lecture-based group. There was no difference in critical thinking between the flipped learning and control groups. The participants in the flipped learning group were more satisfied with the class than those in the lecture-based group. Flipped learning facilitates interactive activities that support the needs of advanced learners and provide more opportunities to develop problem-solving abilities and self-leadership.
MTV-MFO: Multi-Trial Vector-Based Moth-Flame Optimization Algorithm
Authors: Nadimi-Shahraki Mohammad H. , Taghian Shokooh , Mirjalili Seyedali , Ewees Ahmed A. , Abualigah Laith , Abd Elaziz Mohamed
Published: December 2021

The moth-flame optimization (MFO) algorithm is an effective nature-inspired algorithm based on the chemical effect of light on moths as an animal with bilateral symmetry. Although it is widely used to solve different optimization problems, its movement strategy affects the convergence and the balance between exploration and exploitation when dealing with complex problems. Since movement strategies significantly affect the performance of algorithms, the use of multi-search strategies can enhance their ability and effectiveness to solve different optimization problems. In this paper, we propose a multi-trial vector-based moth-flame optimization (MTV-MFO) algorithm. In the proposed algorithm, the MFO movement strategy is substituted by the multi-trial vector (MTV) approach to use a combination of different movement strategies, each of which is adjusted to accomplish a particular behavior. The proposed MTV-MFO algorithm uses three different search strategies to enhance the global search ability, maintain the balance between exploration and exploitation, and prevent the original MFO’s premature convergence during the optimization process. Furthermore, the MTV-MFO algorithm uses the knowledge of inferior moths preserved in two archives to prevent premature convergence and avoid local optima. The performance of the MTV-MFO algorithm was evaluated using 29 benchmark problems taken from the CEC 2018 competition on real parameter optimization. The gained results were compared with eight metaheuristic algorithms. The comparison of results shows that the MTV-MFO algorithm is able to provide competitive and superior results to the compared algorithms in terms of accuracy and convergence rate. Moreover, a statistical analysis of the MTV-MFO algorithm and other compared algorithms was conducted, and the effectiveness of our proposed algorithm was also demonstrated experimentally.
The Fractal Geometry of TiAlNiAu Thin Film Metal System and Its Sheet Resistance (Lateral Size Effect)
Authors: Torkhov Nikolay Anatolyevich , Evstigneev Maxim Pavlovich , Kokolov Andrey Alexandrocivh , Babak Leonid Ivanovich
Published: December 2021

This paper investigates the relation between the geometry of metric space of a TiAlNiAu thin film metal system and the geometry of normed functional space of its sheet resistances (functionals), which are elements of the functional space. The investigation provides a means to describe a lateral size effect that involves a dependency in local approximation of sheet resistance Rsq of TiAlNiAu metal film on its lateral linear dimensions (in (x,y) plane). This dependency is defined by fractal geometry of dendrites, or, more specifically, it is a power-law dependency on fractal dimension Df value. The revealed relation has not only fundamental but also a great practical importance both for a precise calculation of thin film metal system Rsq values in designing discreet devices and ICs, and for controlling results at micro- and nanoscale in producing workflow for thin metal films and systems based on them.
Numerical Simulation of the Evacuation Process in a Tunnel during Contraflow Traffic Operations
Authors: Khaksari Razieh , Harun Zambri , Fielding Les , Aldridge John
Published: December 2021

The purpose of this numerical research is to assess the evacuation process in a tunnel under the contraflow condition. Numerical simulations utilizing FDS+Evac codes associated with a fire dynamic simulator (FDS) model simulating a fire scenario are used to simulate evacuation and to predict the impact of a 100 MW fire scenario on the occupants inside the tunnel. Traffic and passenger conditions are based on real data from a tunnel in the UK. Two fire loads, 100 MW and 5 MW, are studied to represent an HGV and a passenger car fire. The 100 MW fire source, caused by an unexpected heavy good vehicle (HGV) catching fire, is located in the middle of the tunnel and at 20% of tunnel length to study the effect of fire source location on the usage of emergency exits and tenability thresholds. The dimensions and the inclination angle of the existing roadway tunnel are 1836 m (L) × 7.3 m (W) × 5 m (H) and 4%, respectively. It should be noted that the 4% inclination of the tunnel causes asymmetry propagation of smokes thus the visibility of the downstream and upstream from the fire behave differently. The maximum needed time to evacuate using all egress, the amount of fractional effective dose and visibility at the human’s height are analyzed. Simulation results indicate that when a realistic worst-case fire scenario is modeled, all evacuees can survive before the combustion gases and heat influence their survivability.
On Independent Secondary Dominating Sets in Generalized Graph Products
Authors: Michalski Adrian , Bednarz Paweł
Published: December 2021

In 2008, Hedetniemi et al. introduced (1,k)-domination in graphs. The research on this concept was extended to the problem of existence of independent (1,k)-dominating sets, which is an NP-complete problem. In this paper, we consider independent (1,1)- and (1,2)-dominating sets, which we name as (1,1)-kernels and (1,2)-kernels, respectively. We obtain a complete characterization of generalized corona of graphs and G-join of graphs, which have such kernels. Moreover, we determine some graph parameters related to these sets, such as the number and the cardinality. In general, graph products considered in this paper have an asymmetric structure, contrary to other many well-known graph products (Cartesian, tensor, strong).
High Harmonic Generation in Monolayer and Bilayer of Transition Metal Dichalcogenide
Authors: Lee Yeon , Kim Dasol , Kim Dong-Eon , Chacón Alexis
Published: December 2021

In transition metal dichalcogenides (TMDCs), charge carriers have spin, pseudospin, and valley degrees of freedom associated with magnetic moments. The monolayers and bilayers of the TMDCs, in particular, MoS2, lead to strong couplings between the spin and pseudospin effects. This feature has drawn attention to TMDCs for their potential use in advanced tech devices. Meanwhile, high-order harmonic generation (HHG) has recently been applied to the characterization of the electronic structure of solids, such as energy dispersion, Berry-curvature, and topological properties. Here, we show theoretical results obtained with the ‘philosophy’ of using HHG to investigate the structural effects of the monolayer and bilayers of MoS2 on nonlinear optical emission. We use a simple model for MoS2 in the 3R AB staking. We find that the pseudospin and valley indexes (the Berry curvature and the dipole transition matrix element) in TMDC driven by a circularly polarized laser (CPL) can encode in the high-energy photon emissions. This theoretical investigation is expected to pave the way for the ultrafast manipulation of valleytronics and lead to new questions concerning the spin-obit-coupling (SOC) effects on TMDC materials, Weyl Semimetals, and topological phases and transitions in topological insulators.
Comprehensive Analysis and Biological Characterization of Venom Components from Solitary Scoliid Wasp Campsomeriella annulata annulata
Authors: Alberto-Silva Carlos , Vieira Portaro Fernanda Calheta , Kodama Roberto Tadashi , Pantaleão Halyne Queiroz , Inagaki Hidetoshi , Nihei Ken-ichi , Konno Katsuhiro
Published: December 2021

Venoms of solitary wasps are utilized for prey capture (insects and spiders), paralyzing them with a stinger injection to be offered as food for their larvae. Thus, the identification and characterization of the components of solitary wasp venoms can have biotechnological application. In the present study, the venom components profile of a solitary scoliid wasp, Campsomeriella annulata annulata, was investigated through a comprehensive analysis using LC-MS and -MS/MS. Online mass fingerprinting revealed that the venom extract contains 138 components, and MS/MS analysis identified 44 complete sequences of the peptide components. The peptides are broadly divided into two classes: bradykinin-related peptides, and linear α-helical peptides. Among the components of the first class, the two main peptides, α-campsomerin (PRLRRLTGLSPLR) and β-campsomerin (PRLRRLTGLSPLRAP), had their biological activities evaluated. Both peptides had no effects on metallopeptidases [human neprilysin (NEP) and angiotensin-converting enzyme (ACE)] and acetylcholinesterase (AChE), and had no cytotoxic effects. Studies with PC12 neuronal cells showed that only α-campsomerin was able to enhance cell viability, while β-campsomerin had no effect. It is noteworthy that the only difference between the primary structures from these peptides is the presence of the AP extension at the C-terminus of β-campsomerin, compared to α-campsomerin. Among the linear α-helical peptides, annulatin (ISEALKSIIVG-NH2) was evaluated for its biological activities. Annulatin showed histamine releasing activity from mast cells and low hemolytic activity, but no antimicrobial activities against all microbes tested were observed. Thus, in addition to providing unprecedented information on the whole components, the three peptides selected for the study suggest that molecules present in solitary scoliid wasp venoms may have interesting biological activities.
The Antagonistic Effect of Glutamine on Zearalenone-Induced Apoptosis via PI3K/Akt Signaling Pathway in IPEC-J2 Cells
Authors: Wang Tianhu , Wang Jingjing , Zhang Tong , Gu Aixin , Li Jianping , Shan Anshan
Published: December 2021

Zearalenone (ZEN) is a non-steroidal estrogen mycotoxin produced by Fusarium fungi, which inevitably exists in human and animal food or feed. Previous studies indicated that apoptosis seems to be a key determinant of ZEN-induced toxicity. This experiment aimed to investigate the protective effects of Glutamine (Gln) on ZEN-induced cytotoxicity in IPEC-J2 cells. The experimental results showed that Gln was able to alleviate the decline of cell viability and reduce the production of reactive oxygen species and calcium (Ca2+) induced by ZEN. Meanwhile, the mRNA expression of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, and catalase was up-regulated after Gln addition. Subsequently, Gln supplementation resulted in the nuclear fission and Bad-fluorescence distribution of apoptotic cells were weakened, and the mRNA expression and protein expression of pro-apoptotic genes and apoptotic rates were significantly reduced. Moreover, ZEN reduced the phosphorylation Akt, decreased the expression of Bcl-2, and increased the expression of Bax. Gln alleviated the above changes induced by ZEN and the antagonistic effects of Gln were disturbed by PI3K inhibitor (LY294002). To conclude, this study revealed that Gln exhibited significant protective effects on ZEN-induced apoptosis, and this effect may be attributed to the PI3K/Akt signaling pathway.
Platelet Endothelial Cell Adhesion Molecule 1 (CD31) Is Essential for Clostridium perfringens Beta-Toxin Mediated Cytotoxicity in Human Endothelial and Monocytic Cells
Authors: Tarek Basma , Bruggisser Julia , Cattalani Filippo , Posthaus Horst
Published: December 2021

Beta toxin (CPB) is a small hemolysin beta pore-forming toxin (β-PFT) produced by Clostridium perfringens type C. It plays a central role in the pathogenesis of necro-hemorrhagic enteritis in young animals and humans via targeting intestinal endothelial cells. We recently identified the membrane protein CD31 (PECAM-1) as the receptor for CPB on mouse endothelial cells. We now assess the role of CD31 in CPB cytotoxicity against human endothelial and monocytic cells using a CRISPR/Cas9 gene knockout and an antibody blocking approach. CD31 knockout human endothelial and monocytic cells were resistant to CPB and CPB oligomers only formed in CD31-expressing cells. CD31 knockout endothelial and monocytic cells could be selectively enriched out of a polyclonal cell population by exposing them to CPB. Moreover, antibody mediated blocking of the extracellular Ig6 domain of CD31 abolished CPB cytotoxicity and oligomer formation in endothelial and monocytic cells. In conclusion, this study confirms the role of CD31 as a receptor of CPB on human endothelial and monocytic cells. Specific interaction with the CD31 molecule can thus explain the cell type specificity of CPB observed in vitro and corresponds to in vivo observations in naturally diseased animals.
Iron Related Biomarkers Predict Disease Severity in a Cohort of Portuguese Adult Patients during COVID-19 Acute Infection
Authors: Moreira Ana C. , Teles Maria Jose , Silva Tânia , Bento Clara M. , Alves Inês Simões , Pereira Luisa , Guimarães João Tiago , Porto Graça , Oliveira Pedro , Gomes Maria Salomé
Published: December 2021

Large variability in COVID-19 clinical progression urges the need to find the most relevant biomarkers to predict patients’ outcomes. We evaluated iron metabolism and immune response in 303 patients admitted to the main hospital of the northern region of Portugal with variable clinical pictures, from September to November 2020. One hundred and twenty-seven tested positive for SARS-CoV-2 and 176 tested negative. Iron-related laboratory parameters and cytokines were determined in blood samples collected soon after admission. Demographic data, comorbidities and clinical outcomes were recorded. Patients were assigned into five groups according to severity. Serum iron and transferrin levels at admission were lower in COVID-19-positive than in COVID-19-negative patients. The levels of interleukin (IL)-6 and monocyte chemoattractant protein 1 (MCP-1) were increased in COVID-19-positive patients. The lowest serum iron and transferrin levels at diagnosis were associated with the worst outcomes. Iron levels negatively correlated with IL-6 and higher levels of this cytokine were associated with a worse prognosis. Serum ferritin levels at diagnosis were higher in COVID-19-positive than in COVID-19-negative patients. Serum iron is the simplest laboratory test to be implemented as a predictor of disease progression in COVID-19-positive patients.
SARS-CoV-2 Delta Variant Displays Moderate Resistance to Neutralizing Antibodies and Spike Protein Properties of Higher Soluble ACE2 Sensitivity, Enhanced Cleavage and Fusogenic Activity
Authors: Neerukonda Sabari Nath , Vassell Russell , Lusvarghi Sabrina , Wang Richard , Echegaray Fernando , Bentley Lisa , Eakin Ann E. , Erlandson Karl J. , Katzelnick Leah C. , Weiss Carol D. , Wang Wei
Published: December 2021

The SARS-CoV-2 B.1.617 lineage variants, Kappa (B.1.617.1) and Delta (B.1.617.2, AY) emerged during the second wave of infections in India, but the Delta variants have become dominant worldwide and continue to evolve. Here, we compared B.1.617 variants for neutralization resistance by convalescent sera, mRNA vaccine-elicited sera, and therapeutic neutralizing antibodies using a pseudovirus neutralization assay. B.1.617.1, B.1.617.2, and AY.1 pseudoviruses showed a modest 1.5- to 4.4-fold reduction in neutralization by convalescent sera and vaccine-elicited sera. In comparison, similar modest reductions were also observed for C.37, P.1, R.1, and B.1.526 pseudoviruses, but 7- and 16-fold reductions for vaccine-elicited and convalescent sera, respectively, were seen for B.1.351 pseudoviruses. Among twenty-three therapeutic antibodies tested, four antibodies showed either complete or partial loss of neutralization against B.1.617.2 pseudoviruses and six antibodies showed either complete or partial loss of neutralization against B.1.617.1 and AY.1 pseudoviruses. Our results indicate that the current mRNA-based vaccines will likely remain effective in protecting against B.1.617 variants. Finally, the P681R substitution confers efficient cleavage of B.1.617 variants’ spike proteins and the spike of Delta variants exhibited greater sensitivity to soluble ACE2 neutralization, as well as fusogenic activity, which may contribute to enhanced spread of Delta variants.
High Incidence of Strawberry Polerovirus 1 in the Czech Republic and Its Vectors, Genetic Variability and Recombination
Authors: Fránová Jana , Lenz Ondřej , Přibylová Jaroslava , Čmejla Radek , Valentová Lucie , Koloniuk Igor
Published: December 2021

In total, 332 strawberry plants from 33 different locations in the Czech Republic with or without disease symptoms were screened by RT-PCR for the presence of strawberry polerovirus 1 (SPV1) and five other viruses: strawberry mottle virus, strawberry crinkle virus, strawberry mild yellow edge virus, strawberry vein banding virus, and strawberry virus 1. SPV1 was detected in 115 tested strawberry plants (35%), including 89 mixed infections. No correlation between symptoms and the detected viruses was found. To identify potential invertebrate SPV1 vectors, strawberry-associated invertebrate species were screened by RT-PCR, and the virus was found in the aphids Aphis forbesi, A. gossypii, A. ruborum, A.sanquisorbae, Aulacorthum solani, Chaetosiphon fragaefolii, Myzus ascalonicus, and several other non-aphid invertebrate species. SPV1 was also detected in aphid honeydew. Subsequent tests of C. fragaefolii and A.gossypii virus transmission ability showed that at least 4 h of acquisition time were needed to acquire the virus. However, 1 day was sufficient for inoculation using C. fragaefolii. In conclusion, being aphid-transmitted like other tested viruses SPV1 was nevertheless the most frequently detected agent. Czech SPV1 isolates belonged to at least two phylogenetic clusters. The sequence analysis also indicated that recombination events influence evolution of SPV1 genomes.
The A179L Gene of African Swine Fever Virus Suppresses Virus-Induced Apoptosis but Enhances Necroptosis
Authors: Shi Jun , Liu Wei , Zhang Miao , Sun Jing , Xu Xiulong
Published: December 2021

A179L, a non-structural protein of African swine fever virus (ASFV), is capable of suppressing apoptosis by binding the BH3 domain of the pro-apoptotic Bcl-2 family proteins via a conserved ligand binding groove. Our present study aims to determine if A179L affects necroptosis, the second form of programmed cell death induced by DNA and RNA viruses. Here we report that A179L enhanced TNF-α or TSZ (TNF-α, Smac, and Z-Vad)-induced receptor-interacting protein kinase (RIPK1), RIPK3, and mixed lineage kinase domain like peudokinase (MLKL) phosphorylation in L929 cells, a murine fibrosarcoma cell line. Sytox green staining revealed that A179L significantly increased the number of necroptotic cells in TSZ-treated L929 cells. Using human herpes simplex virus 1 (HSV-1) to model DNA virus-induced cell death, we found that A179L blocked the HSV-1-induced cleavage of poly (ADP-ribose) polymerase (PARP), caspase 8, and caspase 3 and decreased the number of apoptotic cells in HSV-1-infected IPEC-DQ cells, a porcine intestinal epithelial cell line. In contrast, A179L transfection of IPEC-DQ cells enhanced HSV-1-induced RIPK1, RIPK3, and MLKL phosphorylation and increased the number of necroptotic cells. Consistently, A179L also suppressed apoptosis but enhanced the necroptosis induced by two RNA viruses, Sendai virus (SeV) and influenza virus (IAV). Our study uncovers a previously unrecognized role of A179L in regulating cell death and suggests that A179L re-directs its anti-apoptotic activity to necroptosis.
Local and Systemic Adverse Reactions to mRNA COVID-19 Vaccines Comparing Two Vaccine Types and Occurrence of Previous COVID-19 Infection
Authors: Parés-Badell Oleguer , Martínez-Gómez Xavier , Pinós Laia , Borras-Bermejo Blanca , Uriona Sonia , Otero-Romero Susana , Rodrigo-Pendás José Ángel , Cossio-Gil Yolima , Agustí Antònia , Aguilera Cristina , Campins Magda
Published: December 2021

The aim of this study was to assess adverse reactions to COVID-19 vaccines, comparing the BNT162b2 or the mRNA-1273 COVID-19 vaccines and the presence and seriousness of a previous COVID-19 infection. We conducted a cross-sectional online survey of vaccinated healthcare workers at a tertiary hospital in Barcelona (Spain). Thirty-eight percent of vaccine recipients responded to the questionnaire. We compared the prevalence of adverse reactions by vaccine type and history of COVID-19 infections. A total of 2373 respondents had received the BNT162b2 vaccine, and 506 the mRNA-1273 vaccine. The prevalence of at least one adverse reaction with doses 1 and 2 was 41% and 70%, respectively, in the BNT162b2 group, and 60% and 92% in the mRNA-1273 group (p < 0.001). The BNT162b2 group reported less prevalence of all adverse reactions. Need for medical leave was significantly more frequent among the mRNA-1273 group (12% versus 4.6% p < 0.001). Interestingly, respondents with a history of allergies or chronic illnesses did not report more adverse reactions. The frequency of adverse reactions with dose 2 was 96% (95% CI 88–100%) for those with a history of COVID-19 related hospitalization, and 86% (95% CI 83–89%) for those with mild or moderate symptomatic COVID-19, significantly higher than for participants with no history of COVID-19 infections (67%, 95% CI 65–69%). Our results could help inform vaccine recipients of the probability of their having adverse reactions to COVID-19 vaccines.
mRNA Vaccine Protects against Zika Virus
Authors: Medina-Magües Lex G. , Gergen Janina , Jasny Edith , Petsch Benjamin , Lopera-Madrid Jaime , Medina-Magües Emily S. , Salas-Quinchucua Cristhian , Osorio Jorge E.
Published: December 2021

Zika virus (ZIKV), a mosquito-borne flavivirus, has recently triggered global concern due to severe health complications. In 2015, a large ZIKV outbreak occurred in the Americas and established a link between ZIKV and microcephaly in newborn babies, spontaneous abortion, persistent viremia, and Guillain–Barré syndrome. While antivirals are being developed and prevention strategies focus on vector control, a safe and effective Zika vaccine remains unavailable. Messenger RNA (mRNA) vaccine technology has arisen as a flexible, simplified, and fast vaccine production platform. Here, we report on an mRNA vaccine candidate that encodes the pre-membrane and envelope (prM–E) glycoproteins of ZIKV strain Brazil SPH2015 and is encapsulated in lipid nanoparticles (LNPs). Our ZIKV prM–E mRNA-LNP vaccine candidate induced antibody responses that protected in AG129 mice deficient in interferon (IFN) alpha/beta/gamma (IFN-α/β/γ) receptors. Notably, a single administration of ZIKV prM–E mRNA-LNP protected against a lethal dose of ZIKV, while a two-dose strategy induced strong protective immunity. E-specific double-positive IFN-γ and TNF-α T-cells were induced in BALB/c mice after immunizations with a two-dose strategy. With the success of mRNA vaccine technology in facing the coronavirus (COVID-19) pandemic, our data support the development of prM–E RNActive® as a promising mRNA vaccine against Zika to counter future epidemics.
Intention of Parents to Immunize Children against SARS-CoV-2 in Italy
Authors: Russo Luisa , Croci Ileana , Campagna Ilaria , Pandolfi Elisabetta , Villani Alberto , Reale Antonino , Barbieri Maria Antonietta , Raponi Massimiliano , Gesualdo Francesco , Tozzi Alberto Eugenio
Published: December 2021

Several countries have targeted adolescents for immunization against SARS-CoV-2 to mitigate COVID-19 spread. In Italy, immunization for children ≥ 12 years has been available starting from June 2021. We conducted a cross-sectional study to investigate the knowledge, attitude and intention to vaccinate children < 18 years in Italian families. We used a multinomial logistic regression model to investigate factors associated with intention to vaccinate. We collected a total of 1696 responses. Among the 491 families of children ≥ 12 years, 41.2% would not vaccinate their children and 21.2% were uncertain, while among the 1205 families of children < 12 years, 36.1% would not vaccinate and 33.8% were uncertain. Determinants of intention to vaccinate both age groups were perceived safety and efficacy of vaccines and perceived risk of transmitting infection to adults. For children < 12 years, additional determinants were perceived risk of being infected and being hospitalized because of COVID-19. In view of the expanding strategy to vaccinate adolescents and the availability of immunization for children < 12 years, our results call for a communication strategy targeted at families of children focused on the safety and efficacy of COVID-19 vaccine in children and on the dynamics of infection spread across different age groups. As perceptions in families are volatile and may change rapidly over time, repeated surveys for measuring attitudes to vaccinate would be advisable.
Humoral Immune Response after the Third SARS-CoV-2 mRNA Vaccination in CD20 Depleted People with Multiple Sclerosis
Authors: Achtnichts Lutz , Jakopp Barbara , Oberle Michael , Nedeltchev Krassen , Fux Christoph Andreas , Sellner Johann , Findling Oliver
Published: December 2021

CD20 depletion is a risk factor for unfavorable outcomes of COVID-19 in people with MS (pwMS). Evidence suggests that protective IgG response to mRNA-based vaccines in B cell-depleted individuals is limited. We studied the seroconversion after the third mRNA SARS-CoV-2 vaccine in B cell-depleted pwMS with limited or no IgG response after the standard immunization. Sixteen pwMS treated with ocrelizumab or rituximab received a third homologous SARS-CoV-2 mRNA vaccine, either the Moderna mRNA-1273 or Pfizer-BioNTech’s BNT162b2 vaccine. We quantified the response of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 four weeks later. An antibody titer of 100 AU/mL or more was considered clinically relevant. The median time between the last infusion of the anti-CD20 treatment and the third vaccination was 22.9 weeks (range 15.1–31.3). After the third vaccination, one out of 16 patients showed an IgG titer deemed clinically relevant. Only the seroconverted patient had measurable B-cell counts at the time of the third vaccination. The development of a humoral immune response remains rare in pwMS on anti-CD20 therapy, even after third dose of the homologous SARS-CoV-2 mRNA vaccine. It remains to be determined whether T-cell responses can compensate for the lack of seroconversion and provide sufficient protection against CoV-2 infections.
Left Pulmonary Artery Coarctation Associated with Pneumonia and Pulmonary Hypertension in a Cat
Authors: Valente Carlotta , Tursi Massimiliano , Poser Helen , Guglielmini Carlo
Published: December 2021

A five-month-old European shorthair female kitten was referred because of recurrent episodes of respiratory distress. Results of physical examination, thoracic radiography, and echocardiography led to a presumptive diagnosis of severe precapillary pulmonary hypertension (PH) and interstitial pneumonia associated with right-sided cardiac remodeling. The cat rapidly died because of respiratory insufficiency. Pulmonary and cardiovascular pathological findings evidenced left pulmonary artery coarctation, severe right-sided cardiac hypertrophy, and bilateral pneumonia. This is the first report of pulmonary artery coarctation associated with pneumonia and PH in a cat.