bluuebunny/crossref_metadata_2025 huggingface dataset:
Applications of Starch Biopolymers for a Sustainable Modern Agriculture
Authors: Gamage Ashoka , Liyanapathiranage Anuradhi , Manamperi Asanga , Gunathilake Chamila , Mani Sudhagar , Merah Othmane , Madhujith Terrence
Published: May 2022

Protected cultivation in modern agriculture relies extensively on plastic-originated mulch films, nets, packaging, piping, silage, and various applications. Polyolefins synthesized from petrochemical routes are vastly consumed in plasticulture, wherein PP and PE are the dominant commodity plastics. Imposing substantial impacts on our geosphere and humankind, plastics in soil threaten food security, health, and the environment. Mismanaged plastics are not biodegradable under natural conditions and generate problematic emerging pollutants such as nano-micro plastics. Post-consumed petrochemical plastics from agriculture face many challenges in recycling and reusing due to soil contamination in fulfilling the zero waste hierarchy. Hence, biodegradable polymers from renewable sources for agricultural applications are pragmatic as mitigation. Starch is one of the most abundant biodegradable biopolymers from renewable sources; it also contains tunable thermoplastic properties suitable for diverse applications in agriculture. Functional performances of starch such as physicomechanical, barrier, and surface chemistry may be altered for extended agricultural applications. Furthermore, starch can be a multidimensional additive for plasticulture that can function as a filler, a metaphase component in blends/composites, a plasticizer, an efficient carrier for active delivery of biocides, etc. A substantial fraction of food and agricultural wastes and surpluses of starch sources are underutilized, without harnessing useful resources for agriscience. Hence, this review proposes reliable solutions from starch toward timely implementation of sustainable practices, circular economy, waste remediation, and green chemistry for plasticulture in agriscience
Learner Autonomy between Students and Teachers at a Defence University: Perception vs. Expectation
Authors: Abd Rahman Emily , Md Yunus Melor , Hashim Harwati , Ab. Rahman Nur Khadirah
Published: May 2022

The success of nurturing learner autonomy lies in the collaboration between two parties—teachers and students. A mismatch of perception and expectation of the desirable level of learner autonomy that should be given in class may lead to failure in developing learner autonomy. Hence, this paper aims to investigate if there are differences between the teachers’ and students’ perceptions of learner autonomy that is currently being practiced in ESL classrooms at a defence university in Malaysia to understand the existing level of learner autonomy in this context, as well as investigate the level of learner autonomy they expect to have in the future. A quantitative research design with descriptive approach was employed using a questionnaire to collect data from 132 students and 10 English teachers. The instrument was based on the twelve categories about learner autonomy through classroom experience and data collected were analysed using SPSS. Results show that the teachers and students are involved collaboratively in carrying learner autonomy. However, all of the significant differences pointed out a higher degree of support for learner autonomy of the students and a lower degree of support for learner autonomy of the teachers. The success of promoting learner autonomy is influenced by the teachers’ beliefs, motivation and encouragement, and also students’ capacity to be autonomous, namely ability, willingness and opportunity.
Location Optimization of Emergency Station for Dangerous Goods Accidents Considering Risk
Authors: Lu Jianfeng , Yang Qiang
Published: May 2022

Emergency station is very important for emergency rescue work in hazardous chemical accidents. In order to ensure the efficiency of emergency rescue work, the setting characteristics and objectives of the emergency station should be comprehensively considered. A bi-level programming model of emergency station location for hazardous chemical accidents is established in this paper. The optimization objectives of the model include the minimum risk of emergency station location, the minimum construction and operation cost, the minimum weighted path distance, and the highest coverage level. Based on the NSGA-II algorithm, the model solving technology is designed and applied to the case analysis. The obtained results showed that the efficiency of emergency rescue is continuously improving with the increase in the number of emergency stations.
An Integrated Modelling Study on the Effects of Weir Operation Scenarios on Aquatic Habitat Changes in the Yeongsan River
Authors: Choi Byungwoong , Kim Byungik , Park Jonghwan , Kang Tae-Woo , Shin Dong-Seok , Na Eun Hye , Choi Jiyeon
Published: May 2022

The Seungchon and Juksan Weirs were constructed in 2012 through four major river projects to control floods and secure water in the Yeongsan River. However, anthropogenic changes in the environment can lead to loss of biodiversity and longitudinal connectivity and the deterioration of ecosystem health. The objective of this study is to evaluate the effects of physical and chemical changes in the Yeongsan River on aquatic habitats through an integrated (water quality–aquatic habitat) model (i.e., Delft3D and HABITAT). The target species used to simulate habitat suitability included Squalidus chankaensis tsuchigae (an endemic fish), Cyprinus carpio, and Micropterus salmoides (an invasive species of fish). Based on the results, maintaining the lowest water level in one of the two weirs was predicted to improve the habitat of the target species. In particular, the habitat area was greatly improved, especially when the Juksan Weir was completely opened. Furthermore, resistance to environmental changes due to habitat area changes indicates that invasive species adapt more to environmental changes than endemic species. This study suggests that physical and chemical changes in the environment can predict the impact on the health of the aquatic ecosystems, which will be useful in establishing an integrated water management plan. These results can be used as basic data for supporting water management policy, to apply an aquatic ecology prediction model suitable for the Yeongsan River system, and to present a management plan for improving the health of an aquatic ecosystem.
A Comprehensive Study of HVDC Link with Reserve Operation Control in a Multi-Infeed Direct Current Power System
Authors: Ramadhan Umar Fitra , Suh Jaewan , Hwang Sungchul , Lee Jaehyeong , Yoon Minhan
Published: May 2022

The Korean government is targeting the development of a renewable energy penetration of 30–35% by 2040 of the total generation. These conditions will decrease network stability due to a lack of inertia, especially in isolated systems, such as Jeju Island. HVDC systems with several balancing arrangements of reserve operation are used to maintain variability and uncontrollability of RES penetration. This paper presents the fast frequency reserves of HVDC control systems for frequency stability enhancement in the isolated power system by using a combined frequency containment process with grid stability standards. A new MIDC reserve operation control with angle and voltage deviation at the bus converter was developed to provide a faster and more appropriate balancing arrangement compared to the other concept. In addition, two layers of energy and transfer-capacity flexibility were considered to prevent the need to hunt for that balancing arrangement, as well as low nadir frequency, unavailability of the reserve and other constraints caused by each region having a different network size, HVDC interconnection capacity, and type. The proposed control schemes were verified by simulations on the Korean power system model implemented in PSS/E for different sizes of disturbance.
Board Characteristics and Integrated Reporting Strategy: Does Sustainability Committee Matter?
Authors: Qaderi Sumaia Ayesh , Ghaleb Belal Ali Abdulraheem , Hashed Abdulwahid Ahmed , Chandren Sitraselvi , Abdullah Zaimah
Published: May 2022

Integrated reporting (IR) is the latest topic in corporate reporting that has raised interest in the disclosure literature. Although the board’s role in IR practice has received significant attention in developed countries, this effect is still unexamined in an emerging market like Malaysia. Thus, this study sought to fill this gap in the IR literature by investigating the impact of the board of directors’ characteristics on the quantity and quality of IR disclosure. The study also examined whether the existence of a sustainability committee affects the board-IR relationship. The study used all listed companies in Bursa Malaysia that applied IR strategy from 2017 to 2020 to test the hypotheses. It employed a content analysis technique to measure the quantity and quality of IR using an index with 100 items based on the International Integrated Reporting Council guidelines. Multivariate ordinary least squares (OLS) regression was applied to examine these relationships. The analysis showed that board size, independence, gender diversity, and non-executive remuneration were positively and significantly related to greater IR disclosure, suggesting that the board of directors has a monitoring role in reducing agency problems and protecting stakeholders’ interests. However, multiple directorships did not affect IR disclosure. The analysis also showed that the presence of a sustainability committee positively affected IR disclosure, and had a moderating effect on the board-IR disclosure relationship. Our result was robust to alternative measures of the corporate board and an alternative regression model. This study is among the first to provide empirical evidence of the board and sustainability committee’s significant role in enhancing IR strategy. The findings may benefit regulatory bodies, policymakers, company managers, investors, and researchers in better understanding how directors’ characteristics influence companies’ IR practices.
Effect of Different Combustion Modes on the Performance of Hydrogen Internal Combustion Engines under Low Load
Authors: Wei Wei , He Xu , Zhu Hairong , Duan Junfa , Qin Gaolin
Published: May 2022

Detailed hydrogen–air chemical reaction mechanisms were coupled with the three-dimensional grids of an experimental hydrogen internal combustion engine (HICE) to establish a computational fluid dynamics (CFD) combustion model based on the CONVERGE software. The effects of different combustion modes on the combustion and emission characteristics of HICE under low load were studied. The simulation results showed that, with the increase in excess hydrogen, the equivalent combustion and excessive hydrogen combustion modes with medium-cooled exhaust gas recirculation (EGR) dilution could improve the intensity of the in-cylinder combustion of HICE, increase the peak values of pressure and temperature in the cylinder, and then improve the indicated thermal efficiency of HICE under low load. However, larger excessive hydrogen combustion could weaken the improvement in performance; therefore, the performance of HICE could be comprehensively improved by the adoption of excessive hydrogen combustion with a fuel–air ratio below 1.2 under low load. The obtained conclusions indicate the research disadvantages in the power and emission performances of HICE under low load, and they are of great significance for the performance optimization of HICE. Furthermore, a control strategy was proposed to improve the stability of HICE under low load.
Subordination Involving Regular Coulomb Wave Functions
Authors: Mondal Saiful R.
Published: May 2022

The functions 1+z, ez, 1+Az, A∈(0,1] map the unit disc D to a domain which is symmetric about the x-axis. The Regular Coulomb wave function (RCWF) FL,η is a function involving two parameters L and η, and FL,η is symmetric about these. In this article, we derive conditions on the parameter L and η for which the normalized form fL of FL,η are subordinated by 1+z. We also consider the subordination by ez and 1+Az, A∈(0,1]. A few more subordination properties involving RCWF are discussed, which leads to the star-likeness of normalized Regular Coulomb wave functions.
The Effect of Media in Mitigating Epidemic Outbreaks: The Sliding Mode Control Approach
Authors: Wongvanich Napasool
Published: May 2022

Ever since the World Health Organization gave the name COVID-19 to the coronavirus pneumonia disease, much of the world has been severely impact by the pandemic socially and economically. In this paper, the mathematical modeling and stability analyses in terms of the susceptible–exposed–infected–removed (SEIR) model with a nonlinear incidence rate, along with media interaction effects, are presented. The sliding mode control methodology is used to design a robust closed loop control of the epidemiological system, where the property of symmetry in the Lyapunov function plays a vital role in achieving the global asymptotic stability in the output. Two policies are considered: the first considers only the governmental interaction, the second considers only the vaccination policy. Numerical simulations of the control algorithms are then evaluated.
The Application of the Modified Prim’s Algorithm to Restore the Power System Using Renewable Energy Sources
Authors: Łukaszewski Artur , Nogal Łukasz , Januszewski Marcin
Published: May 2022

The recent trends in the development of power systems are focused on the Self-Healing Grid technology fusing renewable energy sources. In the event of a failure of the power system, automated distribution grids should continue to supply energy to consumers. Unfortunately, there are currently a limited number of algorithms for rebuilding a power system with renewable energy sources. This problem is possible to solve by implementing restoration algorithms based on graph theory. This article presents the new modification of Prim’s algorithm, which has been adapted to operate on a power grid containing several power sources, including renewable energy sources. This solution is unique because Prim’s algorithm is ultimately dedicated to single-source graph topologies, while the proposed solution is adapted to multi-source topologies. In the algorithm, the power system is modeled by the adjacency matrices. The adjacency matrixes for the considered undirected graphs are symmetric. The novel logic is based on the original method of determining weights depending on active power, reactive power and active power losses. The developed solution was verified by performing a simulation on a test model of the distribution grid powered by a renewable energy source. The control logic concept was compared with the reference algorithms, which were chosen from the ideas representing available approaches based on graph theory present in the scientific publications. The conducted research confirmed the effectiveness and validity of the novel restoration strategy. The presented algorithm may be applied as a restoration logic dedicated to power distribution systems.
RAISE: Rank-Aware Incremental Learning for Remote Sensing Object Detection
Authors: Li Haifeng , Chen Ye , Zhang Zhenshi , Peng Jian
Published: May 2022

The deep learning method is widely used in remote sensing object detection on the premise that the training data have complete features. However, when data with a fixed class are added continuously, the trained detector is less able to adapt to new instances, impelling it to carry out incremental learning (IL). IL has two tasks with knowledge-related symmetry: continuing to learn unknown knowledge and maintaining existing knowledge. Unknown knowledge is more likely to exist in these new instances, which have features dissimilar from those of the old instances and cannot be well adapted by the detector before IL. Discarding all the old instances leads to the catastrophic forgetting of existing knowledge, which can be alleviated by relearning old instances, while different subsets represent different existing knowledge ranges and have different memory-retention effects on IL. Due to the different IL values of the data, the existing methods without appropriate distinguishing treatment preclude the efficient absorption of useful knowledge. Therefore, a rank-aware instance-incremental learning (RAIIL) method is proposed in this article, which pays attention to the difference in learning values from the aspects of the data-learning order and training loss weight. Specifically, RAIIL first designs the rank-score according to inference results and the true labels to determine the learning order and then weights the training loss according to the rank-score to balance the learning contribution. Comparative and analytical experiments conducted on two public remote sensing datasets for object detection, DOTA and DIOR, verified the superiority and effectiveness of the proposed method.
A Normal Distributed Dwarf Mongoose Optimization Algorithm for Global Optimization and Data Clustering Applications
Authors: Aldosari Fahd , Abualigah Laith , Almotairi Khaled H.
Published: May 2022

As data volumes have increased and difficulty in tackling vast and complicated problems has emerged, the need for innovative and intelligent solutions to handle these difficulties has become essential. Data clustering is a data mining approach that clusters a huge amount of data into a number of clusters; in other words, it finds symmetric and asymmetric objects. In this study, we developed a novel strategy that uses intelligent optimization algorithms to tackle a group of issues requiring sophisticated methods to solve. Three primary components are employed in the suggested technique, named GNDDMOA: Dwarf Mongoose Optimization Algorithm (DMOA), Generalized Normal Distribution (GNF), and Opposition-based Learning Strategy (OBL). These parts are used to organize the executions of the proposed method during the optimization process based on a unique transition mechanism to address the critical limitations of the original methods. Twenty-three test functions and eight data clustering tasks were utilized to evaluate the performance of the suggested method. The suggested method’s findings were compared to other well-known approaches. In all of the benchmark functions examined, the suggested GNDDMOA approach produced the best results. It performed very well in data clustering applications showing promising performance.
Automated Coronary Optical Coherence Tomography Feature Extraction with Application to Three-Dimensional Reconstruction
Authors: Carpenter Harry J. , Ghayesh Mergen H. , Zander Anthony C. , Li Jiawen , Di Giovanni Giuseppe , Psaltis Peter J.
Published: May 2022

Coronary optical coherence tomography (OCT) is an intravascular, near-infrared light-based imaging modality capable of reaching axial resolutions of 10–20 µm. This resolution allows for accurate determination of high-risk plaque features, such as thin cap fibroatheroma; however, visualization of morphological features alone still provides unreliable positive predictive capability for plaque progression or future major adverse cardiovascular events (MACE). Biomechanical simulation could assist in this prediction, but this requires extracting morphological features from intravascular imaging to construct accurate three-dimensional (3D) simulations of patients’ arteries. Extracting these features is a laborious process, often carried out manually by trained experts. To address this challenge, numerous techniques have emerged to automate these processes while simultaneously overcoming difficulties associated with OCT imaging, such as its limited penetration depth. This systematic review summarizes advances in automated segmentation techniques from the past five years (2016–2021) with a focus on their application to the 3D reconstruction of vessels and their subsequent simulation. We discuss four categories based on the feature being processed, namely: coronary lumen; artery layers; plaque characteristics and subtypes; and stents. Areas for future innovation are also discussed as well as their potential for future translation.
Transfer of Pesticide Residues from Grapes (Vitis vinifera) into Wine—Correlation with Selected Physicochemical Properties of the Active Substances
Authors: Kittelmann Arno , Müller Carola , Rohn Sascha , Michalski Britta
Published: May 2022

The concentration of pesticide residues in agricultural products at harvest can change during subsequent processing steps. This change, commonly expressed as Processing Factor (PF), is influenced by the raw agricultural commodity, and the processing conditions, as well as the properties of the substances. As it is not possible to conduct processing studies for all possible combinations of pesticide × process × product, new approaches for determining processing factors are needed. Wine was chosen as the object of the present study because it is a widely consumed product. Furthermore, it is already known that the concentration of pesticide residues can change considerably during the processing of grapes into wine, substantiating the need for PFs for a large number of pesticides. The aim of the present study was to investigate the correlation between selected physicochemical properties and PFs. In addition, the influence of different winemaking processes was explored. For this purpose, 70 processing studies conducted by pesticide manufacturers in the framework of regulatory procedures were evaluated in detail and PFs were derived for 20 pesticides. For wine, a good correlation between the PF and the octanol-water partition coefficient of the substances was found, depending on the specific production methods used. Exemplarily, the coefficient of determination for white wine was 0.85, and 0.81 for red wine, when thermovinification was applied. These results can serve as the basis for a predictive model to be validated further with future winemaking studies for pesticides.
CeO2-Zn Nanocomposite Induced Superoxide, Autophagy and a Non-Apoptotic Mode of Cell Death in Human Umbilical-Vein-Derived Endothelial (HUVE) Cells
Authors: Akhtar Mohd Javed , Ahamed Maqusood , Alhadlaq Hisham
Published: May 2022

In this study, a nanocomposite of cerium oxide-zinc (CeO2-Zn; 26 ± 11 nm) based on the antioxidant rare-earth cerium oxide (CeO2) nanoparticles (NPs) with the modifier zinc (Zn) was synthesized by sintering method and characterized. Its bio-response was examined in human umbilical-vein-derived endothelial (HUVE) cells to get insight into the components of vascular system. While NPs of CeO2 did not significantly alter cell viability up to a concentration of 200 µg/mL for a 24 h exposure, 154 ± 6 µg/mL of nanocomposite CeO2-Zn induced 50% cytotoxicity. Mechanism of cytotoxicity occurring due to nanocomposite by its Zn content was compared by choosing NPs of ZnO, possibly the closest nanoparticulate form of Zn. ZnO NPs lead to the induction of higher reactive oxygen species (ROS) (DCF-fluorescence), steeper depletion in antioxidant glutathione (GSH) and a greater loss of mitochondrial membrane potential (MMP) as compared to that induced by CeO2-Zn nanocomposite. Nanocomposite of CeO2-Zn, on the other hand, lead to significant higher induction of superoxide radical (O2•−, DHE fluorescence), nitric oxide (NO, determined by DAR-2 imaging and Griess reagent) and autophagic vesicles (determined by Lysotracker and monodansylcadeverine probes) as compared to that caused by ZnO NP treatment. Moreover, analysis after triple staining (by annexin V-FITC, PI, and Hoechst) conducted at their respective IC50s revealed an apoptosis mode of cell death due to ZnO NPs, whereas CeO2-Zn nanocomposite induced a mechanism of cell death that was significantly different from apoptosis. Our findings on advanced biomarkers such as autophagy and mode of cell death suggested the CeO2-Zn nanocomposite might behave as independent nanostructure from its constituent ones. Since nanocomposites can behave independently of their constituent NPs/elements, by creating nanocomposites, NP versatility can be increased manifold by just manipulating existing NPs. Moreover, data in this study can furnish early mechanistic insight about the potential damage that could occur in the integrity of vascular systems.
Acute and Chronic Toxicity of Binary Mixtures of Bisphenol A and Heavy Metals
Authors: Yang Jun , Liao Anqi , Hu Shulin , Zheng Yiwen , Liang Shuli , Han Shuangyan , Lin Ying
Published: May 2022

Bisphenol A (BPA) and heavy metals are widespread contaminants in the environment. However, the combined toxicities of these contaminants are still unknown. In this study, the bioluminescent bacteria Vibrio qinghaiensis Q67 was used to detect the single and combined toxicities of BPA and heavy metals, then the joint effects of these contaminants were evaluated. The results show that chronic toxicities of chromium (Cr), cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), nickel (Ni), and BPA were time–dependent; in fact, the acute toxicities of these contaminants were stronger than the chronic toxicities. Furthermore, the combined toxicities of BPA and heavy metals displayed BPA + Hg > BPA + Cr > BPA + As > BPA + Ni > BPA + Pb > BPA + Cd in the acute test and BPA + Hg > BPA + Cd > BPA + As > BPA + Cd in the chronic test, which suggested that the combined toxicity of BPA and Hg was stronger than that of other mixtures in acute as well as chronic tests. Additionally, both CA and IA models underestimated the toxicities of mixtures at low concentrations but overestimated them at high concentrations, which indicates that CA and IA models were not suitable to predict the toxicities of mixtures of BPA and heavy metals. Moreover, the joint effects of BPA and heavy metals mainly showed antagonism and additive in the context of acute exposure but synergism and additive in the context of chronic exposure. Indeed, the difference in the joint effects on acute and chronic exposure can be explained by the possibility that mixtures inhibited cell growth and luminescence in chronic cultivation. The chronic toxicity of the mixture should be considered if the mixture results in the inhibition of the growth of cells.
Biological Effects of Animal Venoms on the Human Immune System
Authors: Avalo Zharick , Barrera María Claudia , Agudelo-Delgado Manuela , Tobón Gabriel J. , Cañas Carlos A.
Published: May 2022

Venoms are products of specialized glands and serve many living organisms to immobilize and kill prey, start digestive processes and act as a defense mechanism. Venoms affect different cells, cellular structures and tissues, such as skin, nervous, hematological, digestive, excretory and immune systems, as well as the heart, among other structures. Components of both the innate and adaptive immune systems can be stimulated or suppressed. Studying the effects on the cells and molecules produced by the immune system has been useful in many biomedical fields. The effects of venoms can be the basis for research and development of therapeutic protocols useful in the modulation of the immunological system, including different autoimmune diseases. This review focuses on the understanding of biological effects of diverse venom on the human immune system and how some of their components can be useful for the study and development of immunomodulatory drugs.
Membrane Cholesterol Content and Lipid Organization Influence Melittin and Pneumolysin Pore-Forming Activity
Authors: Ganpule Shamish , Vijaya Akshay Kumar , Sukova Aleksandra , Preta Giulio
Published: May 2022

Melittin, the main toxic component in the venom of the European honeybee, interacts with natural and artificial membranes due to its amphiphilic properties. Rather than interacting with a specific receptor, melittin interacts with the lipid components, disrupting the lipid bilayer and inducing ion leakage and osmotic shock. This mechanism of action is shared with pneumolysin and other members of the cholesterol-dependent cytolysin family. In this manuscript, we investigated the inverse correlation for cholesterol dependency of these two toxins. While pneumolysin-induced damage is reduced by pretreatment with the cholesterol-depleting agent methyl-β-cyclodextrin, the toxicity of melittin, after cholesterol depletion, increased. A similar response was also observed after a short incubation with lipophilic simvastatin, which alters membrane lipid organization and structure, clustering lipid rafts. Therefore, changes in toxin sensitivity can be achieved in cells by depleting cholesterol or changing the lipid bilayer organization.
Understanding the Association between PrEP Stigma and PrEP Cascade Moderated by the Intensity of HIV Testing
Authors: Zhang Chen , Liu Yu
Published: May 2022

(1) Background: In the U.S., men who have sex with men (MSM) account for the majority of new HIV infections. On the other hand, pre-exposure prophylaxis (PrEP) is an effective strategy to curb HIV transmission, but it is widely underutilized. It is unknown how stigma affects PrEP care in the context of other HIV prevention strategies. (2) Methods: We included a total of 318 MSM in the current analysis. We employed bivariate and multivariable analyses to assess the association between PrEP stigma and PrEP cascade while controlling for potential confounders on each specific pathway. We further used a series of moderation analyses based upon the intensity of HIV testing within different timeframes to assess the association between PrEP stigma and PrEP cascade. (3) Results: Compared with MSM who used PrEP, those who never used PrEP reported higher internalized and vicarious PrEP stigma. Internalized PrEP stigma has significantly reduced the likelihood of PrEP willingness and PrEP uptake among this group. The trend analysis showed significant trend patterns across different frequencies of HIV testing. (4) Conclusions: A structural-level reform is urgently needed to turn the HIV service encounters into opportunities to facilitate and optimize the PrEP cascade among this group who may benefit from PrEP use.
A Short Review on the Latest Neutrinos Mass and Number Constraints from Cosmological Observables
Authors: Sakr Ziad
Published: May 2022

We review the neutrino science, focusing on its impact on cosmology along with the latest constraints on its mass and number of species. We also discuss its status as a possible solution to some of the recent cosmological tensions, such as the Hubble constant or the matter fluctuation parameter. We end by showing forecasts from next-generation planned or candidate surveys, highlighting their constraining power, alone or in combination, but also the limitations in determining neutrino mass distribution among its species.
Special Issue: Phage–Bacteria Interplay in Health and Disease
Authors: Drulis-Kawa Zuzanna , Augustyniak Daria
Published: May 2022

Bacteriophages are obligatory parasites propagating in bacterial hosts in a lytic or lysogenic/pseudolysogenic cycle [...]
Simultaneous Giant Virus and Virophage Quantification Using Droplet Digital PCR
Authors: del Arco Ana , Fischer Matthias , Becks Lutz
Published: May 2022

Viruses are an abundant component of aquatic systems, but their detection and quantification remain a challenge. Virophages co-replicate with giant viruses in the shared host cell, and can inhibit the production of new giant virus particles, thereby increasing the survival of the infected host population. Here, we present a protocol for Droplet Digital PCR (ddPCR) to quantify simultaneously giant virus and virophage in a mixed sample, enabling the rapid, culture-free and high throughput detection of virus and virophage. As virophage can be present as free virus particles or integrated into the virus host’s genome as well as associated with organic particles, we developed a simple method that enables discrimination between free and particle-associated virophages. The latter include aggregated virophage particles as well as virophage integrated into the host genome. We used, for our experiments, a host-virus-virophage system consisting of Cafeteria burkhardae, CroV and mavirus. Our results show that ddPCR can be an efficient method to quantify virus and virophage, and we discuss potential applications of the method for studying ecological and evolutionary processes of virus and virophages.
Expanded Basal Compartment and Disrupted Barrier in Vocal Fold Epithelium Infected with Mouse Papillomavirus MmuPV1
Authors: King Renee E. , Ward-Shaw Ella T. , Hu Rong , Lambert Paul F. , Thibeault Susan L.
Published: May 2022

Laryngeal infection with low-risk human papillomaviruses can cause recurrent respiratory papillomatosis (RRP), a disease with severe effects on vocal fold epithelium resulting in impaired voice function and communication. RRP research has been stymied by limited preclinical models. We recently reported a murine model of laryngeal MmuPV1 infection and disease in immunodeficient mice. In the current study, we compare quantitative and qualitative measures of epithelial proliferation, apoptosis, differentiation, and barrier between mice with MmuPV1-induced disease of the larynx and surrounding tissues and equal numbers of uninfected controls. Findings supported our hypothesis that laryngeal MmuPV1 infection recapitulates many features of RRP. Like RRP, MmuPV1 increased proliferation in infected vocal fold epithelium, expanded the basal compartment of cells, decreased differentiated cells, and altered cell–cell junctions and basement membrane. Effects of MmuPV1 on apoptosis were equivocal, as with RRP. Barrier markers resembled human neoplastic disease in severe MmuPV1-induced disease. We conclude that MmuPV1 infection of the mouse larynx provides a useful, if imperfect, preclinical model for RRP that will facilitate further study and treatment development for this intractable and devastating disease.
Understanding the Mechanisms That Drive Phage Resistance in Staphylococci to Prevent Phage Therapy Failure
Authors: Jurado Andrea , Fernández Lucía , Rodríguez Ana , García Pilar
Published: May 2022

Despite occurring at the microscopic scale, the armed race between phages and their bacterial hosts involves multiple mechanisms, some of which are just starting to be understood. On the one hand, bacteria have evolved strategies that can stop the viral infection at different stages (adsorption, DNA injection and replication, biosynthesis and assembly of the viral progeny and/or release of the newly formed virions); on the other, phages have gradually evolved counterattack strategies that allow them to continue infecting their prey. This co-evolutionary process has played a major role in the development of microbial populations in both natural and man-made environments. Notably, understanding the parameters of this microscopic war will be paramount to fully benefit from the application of phage therapy against dangerous, antibiotic-resistant human pathogens. This review gathers the current knowledge regarding the mechanisms of phage resistance in the Staphylococcus genus, which includes Staphylococcus aureus, one of the most concerning microorganisms in terms of antibiotic resistance acquisition. Some of these strategies involve permanent changes to the bacterial cell via mutations, while others are transient, adaptive changes whose expression depends on certain environmental cues or the growth phase. Finally, we discuss the most plausible strategies to limit the impact of phage resistance on therapy, with a special emphasis on the importance of a rational design of phage cocktails in order to thwart therapeutic failure.
Epidemiology and Molecular Analyses of Influenza B Viruses in Senegal from 2010 to 2019
Authors: Touré Cheikh Talibouya , Fall Amary , Andriamandimby Soa Fy , Jallow Mamadou Malado , Goudiaby Deborah , Kiori Davy , Sy Sara , Diaw Yague , Ndiaye Koba Ndiende , Mbaye Fatimata , Niang Mbayang Ndiaye , Heraud Jean Michel , Dia Ndongo
Published: May 2022

Influenza virus types A and B are responsible for acute viral infections that affect annually 1 billion people, with 290,000 to 650,000 deaths worldwide. In this study, we investigated the circulation of influenza B viruses over a 10-year period (2010–2019). Specimens from patients suspected of influenza infection were collected. Influenza detection was performed following RNA extraction and real-time RT-PCR. Genes coding for hemagglutinin (HA) and neuraminidase (NA) of influenza B viruses were partially sequenced, and phylogenetic analyses were carried out subsequently. During the study period, we received and tested a total of 15,156 specimens. Influenza B virus was detected in 1322 (8.7%) specimens. The mean age of influenza B positive patients was 10.9 years. When compared to reference viruses, HA genes from Senegalese circulating viruses showed deletions in the HA1 region. Phylogenetic analysis highlighted the co-circulation of B/Victoria and B/Yamagata lineage viruses with reassortant viruses. We also noted a clear seasonal pattern of circulation of influenza B viruses in Senegal.
The Contribution of Viral Proteins to the Synergy of Influenza and Bacterial Co-Infection
Authors: Mikušová Miriam , Tomčíková Karolína , Briestenská Katarína , Kostolanský František , Varečková Eva
Published: May 2022

A severe course of acute respiratory disease caused by influenza A virus (IAV) infection is often linked with subsequent bacterial superinfection, which is difficult to cure. Thus, synergistic influenza–bacterial co-infection represents a serious medical problem. The pathogenic changes in the infected host are accelerated as a consequence of IAV infection, reflecting its impact on the host immune response. IAV infection triggers a complex process linked with the blocking of innate and adaptive immune mechanisms required for effective antiviral defense. Such disbalance of the immune system allows for easier initiation of bacterial superinfection. Therefore, many new studies have emerged that aim to explain why viral–bacterial co-infection can lead to severe respiratory disease with possible fatal outcomes. In this review, we discuss the key role of several IAV proteins—namely, PB1-F2, hemagglutinin (HA), neuraminidase (NA), and NS1—known to play a role in modulating the immune defense of the host, which consequently escalates the development of secondary bacterial infection, most often caused by Streptococcus pneumoniae. Understanding the mechanisms leading to pathological disorders caused by bacterial superinfection after the previous viral infection is important for the development of more effective means of prevention; for example, by vaccination or through therapy using antiviral drugs targeted at critical viral proteins.
Diagnostic Performance of an Automated System for Assaying Anti-Hepatitis E Virus Immunoglobulins M and G Compared with a Conventional Microplate Assay
Authors: Abravanel Florence , Parraud Delphine , Chapuy-Regaud Sabine , Miedouge Marcel , Bonnin Estelle , Larrieu Margaux , Aversenq Alexandre , Lhomme Sébastien , Izopet Jacques
Published: May 2022

To evaluate the diagnostic performance of the Liaison® Murex anti-HEV IgM and IgG assays running on the Liaison® instrument and compare the results with those obtained with Wantai HEV assays. We tested samples collected in immunocompetent and immunocompromised patients during the acute (HEV RNA positive, anti-HEV IgM positive) and the post-viremic phase (HEV RNA negative, anti-HEV IgM positive) of infections. The specificity was assessed by testing HEV RNA negative/anti-HEV IgG-IgM negative samples. The clinical sensitivity of the Liaison® IgM assay was 100% for acute-phase samples (56/56) and 57.4% (27/47) for post-viremic samples from immunocompetent patients. It was 93.8% (30/32) for acute-phase (viremic) samples and 71%% (22/31) for post-viremic samples from immunocompromised patients. The clinical sensitivity of the Liaison® IgG assay was 100% for viremic samples (56/56) and 94.6% (43/47) for post-viremic samples from immunocompetent patients. It was 84.3% (27/32) for viremic samples and 93.5% (29/31) for post-viremic samples from immunocompromised patients. Specificity was very high (>99%) in both populations. We checked the limit of detection stated for the Liaison® IgG assay (0.3 U/mL). The clinical performance of the Liaison® ANTI-HEV assays was good. These rapid, automated assays for detecting anti-HEV antibodies will greatly enhance the arsenal for diagnosing HEV infections.
Histamine Is Responsible for the Neuropathic Itch Induced by the Pseudorabies Virus Variant in a Mouse Model
Authors: Wang Bing , Wu Hongxia , Qi Hansong , Li Hanglin , Pan Li , Li Lianfeng , Zhang Kehui , Yuan Mengqi , Wang Yimin , Qiu Hua-Ji , Sun Yuan
Published: May 2022

Pseudorabies virus (PRV) is the causative agent of pseudorabies (PR). It can infect a wide range of mammals. PRV infection can cause severe acute neuropathy (the so-called “mad itch”) in nonnatural hosts. PRV can infect the peripheral nervous system (PNS), where it can establish a quiescent, latent infection. The dorsal root ganglion (DRG) contains the cell bodies of the spinal sensory neurons, which can transmit peripheral sensory signals, including itch and somatic pain. Little attention has been paid to the underlying mechanism of the itch caused by PRV in nonnatural hosts. In this study, a mouse model of the itch caused by PRV was elaborated. BALB/c mice were infected intramuscularly with 105 TCID50 of PRV TJ. The frequency of the bite bouts and the durations of itch were recorded and quantified. The results showed that the PRV-infected mice developed spontaneous itch at 32 h postinfection (hpi). The frequency of the bite bouts and the durations of itch were increased over time. The mRNA expression levels of the receptors and the potential cation channels that are relevant to the itch-signal transmission in the DRG neurons were quantified. The mRNA expression levels of tachykinin 1 (TAC1), interleukin 2 (IL-2), IL-31, tryptases, tryptophan hydroxylase 1 (TPH1), and histidine decarboxylase (HDC) were also measured by high-throughput RNA sequencing and real-time reverse transcription PCR. The results showed that the mean mRNA level of the HDC in the DRG neurons isolated from the PRV-infected mice was approximately 25-fold higher than that of the controls at 56 hpi. An immunohistochemistry (IHC) was strongly positive for HDC in the DRG neurons of the PRV-infected mice, which led to the high expression of histamine at the injected sites. The itch of the infected mice was inhibited by chlorphenamine hydrogen maleate (an antagonist for the histamine H1 receptor) in a dose-dependent manner. The mRNA and protein levels of the HDC in the DRG neurons were proportional to the severity of the itch induced by different PRV strains. Taken together, the histamine synthesized by the HDC in the DRG neurons was responsible for the PRV-induced itch in the mice.
Characterization of Vaccine Breakthrough Cases during Measles Outbreaks in Milan and Surrounding Areas, Italy, 2017–2021
Authors: Bianchi Silvia , Gori Maria , Fappani Clara , Ciceri Giulia , Canuti Marta , Colzani Daniela , Dura Marco , Terraneo Mara , Lamberti Anna , Baggieri Melissa , Senatore Sabrina , Faccini Marino , Magurano Fabio , Tanzi Elisabetta , Amendola Antonella
Published: May 2022

Despite the existence of an effective live-attenuated vaccine, measles can appear in vaccinated individuals. We investigated breakthrough measles cases identified during our surveillance activities within the measles/rubella surveillance network (MoRoNet) in Milan and surrounding areas (Northern Italy). Between 2017 and 2021, we confirmed measles virus (genotypes B3 or D8) infections in 653 patients and 51 of these (7.8%) were vaccinees. Among vaccinated individuals whose serum was available, a secondary failure was evidenced in 69.4% (25/36) of cases while 11 patients (30.6%) were non-responders. Non-responders were more frequently hospitalized and had significantly lower Ct values in both respiratory and urine samples. Median age and time since the last immunization were similar in the two groups. Importantly, we identified onward transmissions from vaccine failure cases. Vaccinees were involved in 20 outbreaks, in 10 of them they were able to transmit the virus, and in 8 of them, they were the index case. Comparing viral hemagglutinin sequences from vaccinated and non-vaccinated subjects did not show a specific mutation pattern. These results suggest that vaccination failure was likely due to the poor immune response of single individuals and highlights the importance of identifying breakthrough cases and characterizing their clinical and virologic profiles.
Fecal Feline Coronavirus RNA Shedding and Spike Gene Mutations in Cats with Feline Infectious Peritonitis Treated with GS-441524
Authors: Meli Marina L. , Spiri Andrea M. , Zwicklbauer Katharina , Krentz Daniela , Felten Sandra , Bergmann Michèle , Dorsch Roswitha , Matiasek Kaspar , Alberer Martin , Kolberg Laura , von Both Ulrich , Hartmann Katrin , Hofmann-Lehmann Regina
Published: May 2022

As previously demonstrated by our research group, the oral multicomponent drug Xraphconn® containing GS-441524 was effective at curing otherwise fatal feline infectious peritonitis (FIP) in 18 feline coronavirus (FCoV)-infected cats. The aims of the current study were to investigate, using samples from the same animals as in the previous study, (1) the effect of treatment on fecal viral RNA shedding; (2) the presence of spike gene mutations in different body compartments of these cats; and (3) viral RNA shedding, presence of spike gene mutations, and anti-FCoV antibody titers in samples of 12 companion cats cohabitating with the treated cats. Eleven of the eighteen treated FIP cats (61%) were shedding FCoV RNA in feces within the first three days after treatment initiation, but all of them tested negative by day 6. In one of these cats, fecal shedding reoccurred on day 83. Two cats initially negative in feces were transiently positive 1–4 weeks into the study. The remaining five cats never shed FCoV. Viral RNA loads in feces decreased with time comparable with those in blood and effusion. Specific spike gene mutations linked to systemic FCoV spread were consistently found in blood and effusion from treated FIP cats, but not in feces from treated or companion cats. A new mutation that led to a not yet described amino acid change was identified, indicating that further mutations may be involved in the development of FIP. Eight of the twelve companion cats shed FCoV in feces. All but one of the twelve companion cats had anti-FCoV antibodies. Oral treatment with GS-441524 effectively decreased viral RNA loads in feces, blood, and effusion in cats with FIP. Nonetheless, re-shedding can most likely occur if cats are re-exposed to FCoV by their companion cats.
Inflammatory Gene Expression Associates with Hepatitis B Virus cccDNA- but Not Integrant-Derived Transcripts in HBeAg Negative Disease
Authors: Magri Andrea , Harris James M. , D’Arienzo Valentina , Minisini Rosalba , Jühling Frank , Wing Peter A. C. , Rapetti Rachele , Leutner Monica , Testoni Barbara , Baumert Thomas F. , Zoulim Fabien , Balfe Peter , Pirisi Mario , McKeating Jane A.
Published: May 2022

Chronic hepatitis B virus (HBV) infection is a global health problem that presents as a spectrum of liver disease, reflecting an interplay between the virus and the host immune system. HBV genomes exist as episomal covalently closed circular DNA (cccDNA) or chromosomal integrants. The relative contribution of these genomes to the viral transcriptome in chronic hepatitis B (CHB) is not well-understood. We developed a qPCR method to estimate the abundance of HBV cccDNA- and integrant-derived viral transcripts and applied this to a cohort of patients diagnosed with CHB in the HBe antigen negative phase of disease. We noted a variable pattern of HBV transcripts from both DNA templates, with preS1/S2 mRNAs predominating and a significant association between increasing age and the expression of integrant-derived mRNAs, but not with inflammatory status. In contrast, cccDNA-derived transcripts were associated with markers of liver inflammation. Analysis of the inflammatory hepatic transcriptome identified 24 genes significantly associated with cccDNA transcriptional activity. Our study uncovers an immune gene signature that associates with HBV cccDNA transcription and increases our understanding of viral persistence.