bluuebunny/crossref_metadata_2025 huggingface dataset:
Evacuation Shelter Decision Method Considering Non-Cooperative Evacuee Behavior to Support the Disaster Weak
Authors: Tanaka Tomoki , Matsuda Yuki , Fujimoto Manato , Suwa Hirohiko , Yasumoto Keiichi
Published: May 2021

In disaster situations, special support for the disaster weak are crucial to keep them safe. Common evacuation strategies guide individuals to the shelters closest to their present locations. If evacuees are unevenly distributed across areas, some shelters will not be able to accommodate all arriving evacuees due to the limited capacity of shelters. To tackle this, the existing method decides the destinations for each evacuee considering congestion in disaster areas. However, this method does not consider the disaster weak and can be burdensome for them. Giving that the priority to the disaster weak for shelter decision would be effective to lessen burdens for them, but not all evacuees follow the guidance. When a shelter accepts arriving evacuees unconditionally, some evacuees are rejected, causing a delay in evacuation. If the disaster weak are rejected, the delay will be increased. In this paper, we propose two evacuation shelter decision methods considering the capacity of shelters, the disaster weak, and evacuees’ selfish behavior to realize quick evacuation for the disaster weak: (1) Fixed-rate Reduction Method (FRM), which reduces the assignment number of evacuees less than the capacity at the same percentage to all shelters. (2) Simulation-based Reduction Method (SRM), which reduces the assignment number to shelters that will be crowded based on simulation of an evacuation scenario. Then, these methods decide the destinations for evacuees, with the priority given to the disaster weak. To evaluate the efficiency of the proposed methods, we conducted multi-agent simulation assuming the scenario of evacuation of 30,000 visitors for the Gion Festival including the disaster weak. Through the simulation, we compared our methods with conventional methods including the nearest shelter selection method and the exiting method. As a result, our methods can reduce evacuation time of the disaster weak compared to conventional methods with sufficient cooperation by evacuees.
Photovoltaic BIPV Systems and Architectural Heritage: New Balance between Conservation and Transformation. An Assessment Method for Heritage Values Compatibility and Energy Benefits of Interventions
Authors: Polo López Cristina S. , Troia Floriana , Nocera Francesco
Published: May 2021

This paper proposes to identify an approach methodology for the incorporation of building-integrated photovoltaic systems (BIPV) in existing architectural heritage, considering regulatory, conservation and energy aspects. The main objective is to provide information about guidance criteria related to the integration of BIPV in historical buildings and about intervention methods. That will be followed by the development of useful data to reorient and update the guidelines and guidance documents, both for the design approach and for the evaluation of potential future interventions. The research methodology includes a categorization and analysis of European and Swiss case studies, taking into account the state of preservation of the building before the intervention, the data of the applied photovoltaic technology and the aesthetic and energy contribution of the intervention. The result, in the form of graphic schedules, provides complete information for a real evaluation of the analyzed case studies and of the BIPV technological system used in historical contexts. This research promotes a conscious BIPV as a real opportunity to use technology and a contemporary architectural language capable of dialoguing with pre-existing buildings to significantly improve energy efficiency and determine a new value system for the historical building and its environment.
Large-Scale Road Network Congestion Pattern Analysis and Prediction Using Deep Convolutional Autoencoder
Authors: Ranjan Navin , Bhandari Sovit , Khan Pervez , Hong Youn-Sik , Kim Hoon
Published: May 2021

The transportation system, especially the road network, is the backbone of any modern economy. However, with rapid urbanization, the congestion level has surged drastically, causing a direct effect on the quality of urban life, the environment, and the economy. In this paper, we propose (i) an inexpensive and efficient Traffic Congestion Pattern Analysis algorithm based on Image Processing, which identifies the group of roads in a network that suffers from reoccurring congestion; (ii) deep neural network architecture, formed from Convolutional Autoencoder, which learns both spatial and temporal relationships from the sequence of image data to predict the city-wide grid congestion index. Our experiment shows that both algorithms are efficient because the pattern analysis is based on the basic operations of arithmetic, whereas the prediction algorithm outperforms two other deep neural networks (Convolutional Recurrent Autoencoder and ConvLSTM) in terms of large-scale traffic network prediction performance. A case study was conducted on the dataset from Seoul city.
The Influence of the Digital Supply Chain on Operational Performance: A Study of the Food and Beverage Industry in Indonesia
Authors: Saryatmo Mohammad Agung , Sukhotu Vatcharapol
Published: May 2021

In this rapidly developing digital era, digital transformations take place within every industry, and they have effects on the management of the supply chains. The aim of this study is to delve into the influence of the digital supply chain on the quality, productivity, and cost reduction aspects of operational performance. This study relies on quantitative methodology and data collected from the food and beverage industry of Indonesia. Data from a survey comprising a total of 209 responses were selected for investigation. PLS-SEM was used to perform the analysis. The investigation reveals that the digital supply chain has significant effects on operational performance in terms of quality, productivity, and cost reduction performance. This study contributes to the understanding of supply chain management by addressing the knowledge gap associated with the digital supply chain. In particular, it has concentrated on the hitherto unresearched effect of operational performance in the context of the Indonesian manufacturing industry.
Optimizing the Power Generation of a Wind Farm in Low Wind Speed Regions
Authors: Taleb Hanan M. , Abu Hijleh Bassam
Published: May 2021

The aim of this research is to optimize the power generation of a wind farm (WF) in order to maximize the energy output, especially in low wind speeds regions such as UAE. A new WF was proposed to be built in Sir Bani Yas Island in the UAE. This project was chosen to act as the main case configuration for this research. Four configuration parameters were proposed and assessed as follows: (1) inserting smaller turbines between the original larger main turbines; (2) changing the spacing between the turbines; (3) substituting new higher efficiency turbines in place of the existing ones; (4) moving the WFs to completely new locations in different emirates within the UAE. Through using the WindFarm simulation software, the impact of these four strategies was analyzed and calculated. The main finding of this research indicates that introducing more efficient WT units has a great impact in that it can increase output by 24.5%. Bearing in mind that the UAE has a vision for a renewable energy, as well as the Gulf Cooperation Council (GCC) countries, this paper will draw a novel recommendation to optimize the wind power generation in this low-speed region.
New Aspects for Oscillation of Differential Systems with Mixed Delays and Impulses
Authors: Santra Shyam Sundar , Khedher Khaled Mohamed , Yao Shao-Wen
Published: May 2021

Oscillation and symmetry play an important role in many applications such as engineering, physics, medicine, and vibration in flight. In this work, we obtain sufficient and necessary conditions for the oscillation of the solutions to a second-order differential equation with impulses and mixed delays when the neutral coefficient lies within [0,1). Furthermore, an examination of the validity of the proposed criteria has been demonstrated via particular examples.
Inverse Derivative Operator and Umbral Methods for the Harmonic Numbers and Telescopic Series Study
Authors: Dattoli Giuseppe , Licciardi Silvia , Pidatella Rosa Maria
Published: May 2021

The formalism of differ-integral calculus, initially developed to treat differential operators of fractional order, realizes a complete symmetry between differential and integral operators. This possibility has opened new and interesting scenarios, once extended to positive and negative order derivatives. The associated rules offer an elegant, yet powerful, tool to deal with integral operators, viewed as derivatives of order-1. Although it is well known that the integration is the inverse of the derivative operation, the aforementioned rules offer a new mean to obtain either an explicit iteration of the integration by parts or a general formula to obtain the primitive of any infinitely differentiable function. We show that the method provides an unexpected link with generalized telescoping series, yields new useful tools for the relevant treatment, and allows a practically unexhausted tool to derive identities involving harmonic numbers and the associated generalized forms. It is eventually shown that embedding the differ-integral point of view with techniques of umbral algebraic nature offers a new insight into, and the possibility of, establishing a new and more powerful formalism.
Exploring the High-Temperature Electrical Performance of Ca3−xLaxCo4O9 Thermoelectric Ceramics for Moderate and Low Substitution Levels
Authors: Constantinescu Gabriel , Rasekh Shahed , Amirkhizi Parisa , Lopes Daniela V. , Vieira Miguel A. , Kovalevsky Andrei V. , Diez Juan C. , Sotelo Andres , Madre Maria A. , Torres Miguel A.
Published: May 2021

Aliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical properties and the solubility, and impact of the substituting cation also depends largely on the preparation and processing method. It is also well-known that the monoclinic symmetry of this material’s composite crystal structure allows for a significant hole transfer from the rock salt-type Ca2CoO3 buffer layers to the hexagonal CoO2 ones, increasing the concentration of holes and breaking the electron–hole symmetry from the latter layers. This work explored the relevant effects of relatively low La-for-Ca substitutions, for samples prepared and processed through a conventional ceramic route, chosen for its simplicity. The obtained results show that the actual substitution level does not exceed 0.03 (x < 0.03) in Ca3−xLaxCo4O9 samples with x = 0.01, 0.03, 0.05 and 0.07 and that further introduction of lanthanum results in simultaneous Ca3Co4O9 phase decomposition and secondary Ca3Co2O6 and (La,Ca)CoO3 phase formation. The microstructural effects promoted by this phase evolution have a moderate influence on the electronic transport. The electrical measurements and determined average oxidation state of cobalt at room temperature suggest that the present La substitutions might only have a minor effect on the concentration of charge carriers and/or their mobility. The electrical resistivity values of the Ca3−xLaxCo4O9 samples with x = 0.01, 0.03 and 0.05 were found to be ~1.3 times (or 24%) lower (considering mean values) than those measured for the pristine Ca3Co4O9 samples, while the changes in Seebeck coefficient values were only moderate. The highest power factor value calculated for Ca2.99La0.01Co4O9 (~0.28 mW/K2m at 800 °C) is among the best found in the literature for similar materials. The obtained results suggest that low rare-earth substitutions in the rock salt-type layers can be a promising pathway in designing and improving these p-type thermoelectric oxides, provided by the strong interplay between the mobility of charge carriers and their concentration, capable of breaking the electron–hole symmetry from the conductive layers.
The Comparative Study for Solving Fractional-Order Fornberg–Whitham Equation via ρ-Laplace Transform
Authors: Sunthrayuth Pongsakorn , Zidan Ahmed M. , Yao Shao-Wen , Shah Rasool , Inc Mustafa
Published: May 2021

In this article, we also introduced two well-known computational techniques for solving the time-fractional Fornberg–Whitham equations. The methods suggested are the modified form of the variational iteration and Adomian decomposition techniques by ρ-Laplace. Furthermore, an illustrative scheme is introduced to verify the accuracy of the available methods. The graphical representation of the exact and derived results is presented to show the suggested approaches reliability. The comparative solution analysis via graphs also represented the higher reliability and accuracy of the current techniques.
Dynamics of an Eco-Epidemic Predator–Prey Model Involving Fractional Derivatives with Power-Law and Mittag–Leffler Kernel
Authors: Panigoro Hasan S. , Suryanto Agus , Kusumawinahyu Wuryansari Muharini , Darti Isnani
Published: May 2021

In this paper, we consider a fractional-order eco-epidemic model based on the Rosenzweig–MacArthur predator–prey model. The model is derived by assuming that the prey may be infected by a disease. In order to take the memory effect into account, we apply two fractional differential operators, namely the Caputo fractional derivative (operator with power-law kernel) and the Atangana–Baleanu fractional derivative in the Caputo (ABC) sense (operator with Mittag–Leffler kernel). We take the same order of the fractional derivative in all equations for both senses to maintain the symmetry aspect. The existence and uniqueness of solutions of both eco-epidemic models (i.e., in the Caputo sense and in ABC sense) are established. Both models have the same equilibrium points, namely the trivial (origin) equilibrium point, the extinction of infected prey and predator point, the infected prey free point, the predator-free point and the co-existence point. For a model in the Caputo sense, we also show the non-negativity and boundedness of solution, perform the local and global stability analysis and establish the conditions for the existence of Hopf bifurcation. It is found that the trivial equilibrium point is a saddle point while other equilibrium points are conditionally asymptotically stable. The numerical simulations show that the solutions of the model in the Caputo sense strongly agree with analytical results. Furthermore, it is indicated numerically that the model in the ABC sense has quite similar dynamics as the model in the Caputo sense. The essential difference between the two models is the convergence rate to reach the stable equilibrium point. When a Hopf bifurcation occurs, the bifurcation points and the diameter of the limit cycles of both models are different. Moreover, we also observe a bistability phenomenon which disappears via Hopf bifurcation.
Low-Resource Named Entity Recognition via the Pre-Training Model
Authors: Chen Siqi , Pei Yijie , Ke Zunwang , Silamu Wushour
Published: May 2021

Named entity recognition (NER) is an important task in the processing of natural language, which needs to determine entity boundaries and classify them into pre-defined categories. For low-resource languages, most state-of-the-art systems require tens of thousands of annotated sentences to obtain high performance. However, there is minimal annotated data available about Uyghur and Hungarian (UH languages) NER tasks. There are also specificities in each task—differences in words and word order across languages make it a challenging problem. In this paper, we present an effective solution to providing a meaningful and easy-to-use feature extractor for named entity recognition tasks: fine-tuning the pre-trained language model. Therefore, we propose a fine-tuning method for a low-resource language model, which constructs a fine-tuning dataset through data augmentation; then the dataset of a high-resource language is added; and finally the cross-language pre-trained model is fine-tuned on this dataset. In addition, we propose an attention-based fine-tuning strategy that uses symmetry to better select relevant semantic and syntactic information from pre-trained language models and apply these symmetry features to name entity recognition tasks. We evaluated our approach on Uyghur and Hungarian datasets, which showed wonderful performance compared to some strong baselines. We close with an overview of the available resources for named entity recognition and some of the open research questions.
System of Time Fractional Models for COVID-19: Modeling, Analysis and Solutions
Authors: Iyiola Olaniyi , Oduro Bismark , Zabilowicz Trevor , Iyiola Bose , Kenes Daniel
Published: May 2021

The emergence of the COVID-19 outbreak has caused a pandemic situation in over 210 countries. Controlling the spread of this disease has proven difficult despite several resources employed. Millions of hospitalizations and deaths have been observed, with thousands of cases occurring daily with many measures in place. Due to the complex nature of COVID-19, we proposed a system of time-fractional equations to better understand the transmission of the disease. Non-locality in the model has made fractional differential equations appropriate for modeling. Solving these types of models is computationally demanding. Our proposed generalized compartmental COVID-19 model incorporates effective contact rate, transition rate, quarantine rate, disease-induced death rate, natural death rate, natural recovery rate, and recovery rate of quarantine infected for a holistic study of the coronavirus disease. A detailed analysis of the proposed model is carried out, including the existence and uniqueness of solutions, local and global stability analysis of the disease-free equilibrium (symmetry), and sensitivity analysis. Furthermore, numerical solutions of the proposed model are obtained with the generalized Adam–Bashforth–Moulton method developed for the fractional-order model. Our analysis and solutions profile show that each of these incorporated parameters is very important in controlling the spread of COVID-19. Based on the results with different fractional-order, we observe that there seems to be a third or even fourth wave of the spike in cases of COVID-19, which is currently occurring in many countries.
Nanofluids Characterization for Spray Cooling Applications
Authors: Sanches Miguel , Marseglia Guido , Ribeiro Ana P. C. , Moreira António L. N. , Moita Ana S.
Published: May 2021

In this paper the mathematical and physical correlation between fundamental thermophysical properties of materials, with their structure, for nanofluid thermal performance in spray cooling applications is presented. The present work aims at clarifying the nanofluid characteristics, especially the geometry of their nanoparticles, leading to heat transfer enhancement at low particle concentration. The base fluid considered is distilled water with the surfactant cetyltrimethylammonium bromide (CTAB). Alumina and silver are used as nanoparticles. A systematic analysis addresses the effect of nanoparticles concentration and shape in spray hydrodynamics and heat transfer. Spray dynamics is mainly characterized using phase Doppler interferometry. Then, an extensive processing procedure is performed to thermal and spacetime symmetry images obtained with a high-speed thermographic camera to analyze the spray impact on a heated, smooth stainless-steel foil. There is some effect on the nanoparticles’ shape, which is nevertheless minor when compared to the effect of the nanoparticles concentration and to the change in the fluid properties caused by the addition of the surfactant. Hence, increasing the nanoparticles concentration results in lower surface temperatures and high removed heat fluxes. In terms of the effect of the resulting thermophysical properties, increasing the nanofluids concentration resulted in the increase in the thermal conductivity and dynamic viscosity of the nanofluids, which in turn led to a decrease in the heat transfer coefficients. On the other hand, nanofluids specific heat capacity is increased which correlates positively with the spray cooling capacity. The analysis of the parameters that determine the structure, evolution, physics and both spatial and temporal symmetry of the spray is interesting and fundamental to shed light to the fact that only knowledge based in experimental data can guarantee a correct setting of the model numbers.
The Existence, Uniqueness, and Stability Analysis of the Discrete Fractional Three-Point Boundary Value Problem for the Elastic Beam Equation
Authors: Alzabut Jehad , Selvam A. George Maria , Dhineshbabu R. , Kaabar Mohammed K. A.
Published: May 2021

An elastic beam equation (EBEq) described by a fourth-order fractional difference equation is proposed in this work with three-point boundary conditions involving the Riemann–Liouville fractional difference operator. New sufficient conditions ensuring the solutions’ existence and uniqueness of the proposed problem are established. The findings are obtained by employing properties of discrete fractional equations, Banach contraction, and Brouwer fixed-point theorems. Further, we discuss our problem’s results concerning Hyers–Ulam (HU), generalized Hyers–Ulam (GHU), Hyers–Ulam–Rassias (HUR), and generalized Hyers–Ulam–Rassias (GHUR) stability. Specific examples with graphs and numerical experiment are presented to demonstrate the effectiveness of our results.
Immunotoxicity of Per- and Polyfluoroalkyl Substances: Insights into Short-Chain PFAS Exposure
Authors: Woodlief Tracey , Vance Samuel , Hu Qing , DeWitt Jamie
Published: May 2021

Novel per- and polyfluoroalkyl substances (PFAS) were recently identified in drinking water sources throughout North Carolina. These include the perfluoroether acids (PFEAs) perfluoro-2-methoxyacetic acid (PFMOAA), perfluoro-2-methoxypropanoic acid (PFMOPrA), and perfluoro-4-methoxybutanioc acid (PFMOBA). Little toxicological data exist for these PFEAs. Therefore, the present study described signs of toxicity and immunotoxicity following oral exposure. Adult male and female C57BL/6 mice were exposed once/day for 30 days to PFMOAA (0, 0.00025, 0.025, or 2.5 mg/kg), PFMOPrA, or PFMOBA (0, 0.5, 5, or 50 mg/kg). A dose of 7.5 mg/kg of perfluorooctanoic acid (PFOA) was used as a positive control. Terminal body weights, and absolute liver, spleen, or thymus weights did not differ by dose for any compound; exposure to 50 mg/kg of PFMOBA increased relative liver weights in males. Changes in splenic cellularity were observed in males exposed to PFMOPrA and decreased numbers of B and natural killer (NK) cells were observed in males and females exposed to PFMOBA. Exposure did not alter NK cell cytotoxicity or T cell-dependent antibody responses at doses administered. Our results indicate that these “understudied” PFAS have toxicological potential but require additional investigation across endpoints and species, including humans, to understand health effects via drinking water exposure.
Validation of a Method Scope Extension for the Analysis of POPs in Soil and Verification in Organic and Conventional Farms of the Canary Islands
Authors: Acosta-Dacal Andrea , Rial-Berriel Cristian , Díaz-Díaz Ricardo , Bernal-Suárez María , Zumbado Manuel , Henríquez-Hernández Luis , Alonso-González Pablo , Parga-Dans Eva , Luzardo Octavio
Published: May 2021

Persistent organic pollutants (POPs) are among the most relevant and dangerous contaminants in soil, from where they can be transferred to crops. Additionally, livestock animals may inadvertently consume relatively high amounts of soil attached to the roots of the vegetables while grazing, leading to indirect exposure to humans. Therefore, periodic monitoring of soils is crucial; thus, simple, robust, and powerful methods are needed. In this study, we have tested and validated an easy QuEChERS-based method for the extraction of 49 POPs (8 PBDEs, 12 OCPs, 11 PAHs, and 18 PCBs) in soils and their analysis by GC-MS/MS. The method was validated in terms of linearity, precision, and accuracy, and a matrix effect study was performed. The limits of detection (LOD) were established between 0.048 and 3.125 ng g−1 and the limits of quantification (LOQ) were between 0.5 and 20 ng g−1, except for naphthalene (50 ng g−1). Then, to verify the applicability of the validated method, we applied it to a series of 81 soil samples from farms dedicated to mixed vegetable cultivation and vineyards in the Canary Islands, both from two modes of production (organic vs. conventional) where residues of OCPs, PCBs, and PAHs were found.
Three-Finger Toxins from Brazilian Coral Snakes: From Molecular Framework to Insights in Biological Function
Authors: Kleiz-Ferreira Jessica Matos , Cirauqui Nuria , Trajano Edson Araujo , Almeida Marcius da Silva , Zingali Russolina Benedeta
Published: May 2021

Studies on 3FTxs around the world are showing the amazing diversity in these proteins both in structure and function. In Brazil, we have not realized the broad variety of their amino acid sequences and probable diversified structures and targets. In this context, this work aims to conduct an in silico systematic study on available 3FTxs found in Micrurus species from Brazil. We elaborated a specific guideline for this toxin family. First, we grouped them according to their structural homologue predicted by HHPred server and further curated manually. For each group, we selected one sequence and constructed a representative structural model. By looking at conserved features and comparing with the information available in the literature for this toxin family, we managed to point to potential biological functions. In parallel, the phylogenetic relationship was estimated for our database by maximum likelihood analyses and a phylogenetic tree was constructed including the homologous 3FTx previously characterized. Our results highlighted an astonishing diversity inside this family of toxins, showing some groups with expected functional similarities to known 3FTxs, and pointing out others with potential novel roles and perhaps structures. Moreover, this classification guideline may be useful to aid future studies on these abundant toxins.
Charged Residues Flanking the Transmembrane Domain of Two Related Toxin–Antitoxin System Toxins Affect Host Response
Authors: Holmes Andrew , Sadlon Jessie , Weaver Keith
Published: May 2021

A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.
Acute Exposure to European Viper Bite in Children: Advocating for a Pediatric Approach
Authors: Marano Marco , Pisani Mara , Zampini Giorgio , Pontrelli Giuseppe , Roversi Marco
Published: May 2021

Viper bite is an uncommon but serious cause of envenoming in Europe, especially in children. Our study aim is to better describe and analyze the clinical course and treatment of viper bite envenoming in a pediatric population. We retrospectively reviewed 24 cases of pediatric viper bites that were admitted to the Pediatric Emergency Department and the Pediatric Intensive Care Unit of the Bambino Gesù Children Hospital in Rome between 2000 and 2020. Epidemiological characteristics of the children, localization of the bite, clinical and laboratory findings, and treatment approaches were evaluated. The median age of the patients was 4.2 years, with male predominance. Most cases of viper bite occurred in the late summer. Most patients required admission to the ward for prolonged observation. The most common presenting signs were pain, local oedema, and swelling. Patients with a high severity score also had a significantly higher white blood cell count and an increase of INR, LDH, and CRP levels. No fatality was reported. Viper bite envenomation is a rare pediatric medical emergency in Italy but may sometimes be severe. A new pediatric severity score may be implemented in the screening of children with viper bites to favor a selective and prompt administration of antivenom.
Infection Prevention and Control at Lira University Hospital, Uganda: More Needs to Be Done
Authors: Opollo Marc Sam , Otim Tom Charles , Kizito Walter , Thekkur Pruthu , Kumar Ajay M. V. , Kitutu Freddy Eric , Kisame Rogers , Zolfo Maria
Published: May 2021

Globally, 5–15% of hospitalized patients acquire infections (often caused by antimicrobial-resistant microbes) due to inadequate infection prevention and control (IPC) measures. We used the World Health Organization’s (WHO) ‘Infection Prevention and Control Assessment Framework’ (IPCAF) tool to assess the IPC compliance at Lira University hospital (LUH), a teaching hospital in Uganda. We also characterized challenges in completing the tool. This was a hospital-based, cross-sectional study conducted in November 2020. The IPC focal person at LUH completed the WHO IPCAF tool. Responses were validated, scored, and interpreted per WHO guidelines. The overall IPC compliance score at LUH was 225/800 (28.5%), implying a basic IPC compliance level. There was no IPC committee, no IPC team, and no budgets. Training was rarely or never conducted. There was no surveillance system and no monitoring/audit of IPC activities. Bed capacity, water, electricity, and disposal of hospital waste were adequate. Disposables and personal protective equipment were not available in appropriate quantities. Major challenges in completing the IPCAF tool were related to the detailed questions requiring repeated consultation with other hospital stakeholders and the long time it took to complete the tool. IPC compliance at LUH was not optimal. The gaps identified need to be addressed urgently.
The Dirac Sea, T and C Symmetry Breaking, and the Spinor Vacuum of the Universe
Authors: Monakhov Vadim
Published: May 2021

We have developed a quantum field theory of spinors based on the algebra of canonical anticommutation relations (CAR algebra) of Grassmann densities in the momentum space. We have proven the existence of two spinor vacua. Operators C and T transform the normal vacuum into an alternative one, which leads to the breaking of the C and T symmetries. The CPT is the real structure operator; it preserves the normal vacuum. We have proven that, in the theory of the Dirac Sea, the formula for the charge conjugation operator must contain an additional generalized Dirac conjugation operator.
Towards a Geometrization of Renormalization Group Histories in Asymptotic Safety
Authors: Ferrero Renata , Reuter Martin
Published: May 2021

Considering the scale-dependent effective spacetimes implied by the functional renormalization group in d-dimensional quantum Einstein gravity, we discuss the representation of entire evolution histories by means of a single, (d+1)-dimensional manifold furnished with a fixed (pseudo-) Riemannian structure. This “scale-spacetime” carries a natural foliation whose leaves are the ordinary spacetimes seen at a given resolution. We propose a universal form of the higher dimensional metric and discuss its properties. We show that, under precise conditions, this metric is always Ricci flat and admits a homothetic Killing vector field; if the evolving spacetimes are maximally symmetric, their (d+1)-dimensional representative has a vanishing Riemann tensor even. The non-degeneracy of the higher dimensional metric that “geometrizes” a given RG trajectory is linked to a monotonicity requirement for the running of the cosmological constant, which we test in the case of asymptotic safety.
Geodesic Incompleteness and Partially Covariant Gravity
Authors: Antoniadis Ignatios , Cotsakis Spiros
Published: May 2021

We study the issue of length renormalization in the context of fully covariant gravity theories as well as non-relativistic ones such as Hořava–Lifshitz gravity. The difference in their symmetry groups implies a relation among the lengths of paths in spacetime in the two types of theory. Provided that certain asymptotic conditions hold, this relation allows us to transfer analytic criteria for the standard spacetime length to be finite and the Perelman length to be likewise finite, and therefore formulate conditions for geodesic incompleteness in partially covariant theories. We also discuss implications of this result for the issue of singularities in the context of such theories.
Vacuum Polarization in a Zero-Width Potential: Self-Adjoint Extension
Authors: Grats Yuri V. , Spirin Pavel
Published: May 2021

The effects of vacuum polarization associated with a massless scalar field near pointlike source with a zero-range potential in three spatial dimensions are analyzed. The “physical” approach consists in the usage of direct delta-potential as a model of pointlike interaction. We use the Perturbation theory in the Fourier space with dimensional regularization of the momentum integrals. In the weak-field approximation, we compute the effects of interest. The “mathematical” approach implies the self-adjoint extension technique. In the Quantum-Field-Theory framework we consider the massless scalar field in a 3-dimensional Euclidean space with an extracted point. With appropriate boundary conditions it is considered an adequate mathematical model for the description of a pointlike source. We compute the renormalized vacuum expectation value ⟨ϕ2(x)⟩ren of the field square and the renormalized vacuum averaged of the scalar-field’s energy-momentum tensor ⟨Tμν(x)⟩ren. For the physical interpretation of the extension parameter we compare these results with those of perturbative computations. In addition, we present some general formulae for vacuum polarization effects at large distances in the presence of an abstract weak potential with finite-sized compact support.
Gentrification and Touristification in the Central Urban Areas of Seville and Cádiz
Authors: Parralejo Julio-José , Díaz-Parra Ibán
Published: May 2021

Intensive tourism in historic city centers is causing socio-spatial effects that are already visible to society. This has led politicians and academics to focus on the issue, creating a debate about gentrification in certain central urban areas which overlaps with studies on touristification, understood by some authors as tourism gentrification. This article aims to identify whether socio-demographic changes identifiable as touristification have occurred in the historic centers of two Andalusian cities, Seville and Cádiz, and which we interpret as the replacement of residents with visitors. The work is based primarily on the exploratory analysis of socio-demographic data from the Population Register and data on housing and rentals provided by different sources. The work shows strong indications of a relationship between the increase of tourist apartments and losses of residents in both historic centers. The paper concludes by pointing to the need for further research on this relationship in public statistics that can guide future policy action.
Development and Validation of a Mucosal Antibody (IgA) Test to Identify Persistent Infection with Foot-and-Mouth Disease Virus
Authors: Biswal Jitendra K. , Nardo Antonello Di , Taylor Geraldine , Paton David J. , Parida Satya
Published: May 2021

It is well known that approximately 50% of cattle infected with foot-and-mouth disease (FMD) virus (FMDV) may become asymptomatic carrier (persistently infected) animals. Although transmission of FMDV from carrier cattle to naïve cattle has not been demonstrated experimentally, circumstantial evidence from field studies has linked FMDV-carrier cattle to cause subsequent outbreaks. Therefore, the asymptomatic carrier state complicates the control and eradication of FMD. Current serological diagnosis using tests for antibodies to the viral non-structural proteins (NSP-ELISA) are not sensitive enough to detect all carrier animals, if persistently infected after vaccination and do not distinguish between carriers and non-carriers. The specificity of the NSP ELISA may also be reduced after vaccination, in particular after multiple vaccination. FMDV-specific mucosal antibodies (IgA) are not produced in vaccinated cattle but are elevated transiently during the acute phase of infection and can be detected at a high level in cattle persistently infected with FMDV, irrespective of their vaccination status. Therefore, detection of IgA by ELISA may be considered a diagnostic alternative to RT-PCR for assessing FMDV persistent infection in ruminants in both vaccinated and unvaccinated infected populations. This study reports on the development and validation of a new mucosal IgA ELISA for the detection of carrier animals using nasal, saliva, and oro-pharyngeal fluid (OPF) samples. The diagnostic performance of the IgA ELISA using nasal samples from experimentally vaccinated and infected cattle demonstrated a high level of specificity (99%) and an improved level of sensitivity (76.5%). Furthermore, the detection of carrier animals reached 96.9% when parallel testing of samples was carried out using both the IgA-ELISA and NSP-ELISA.
N-Glycolylneuraminic Acid in Animal Models for Human Influenza A Virus
Authors: Spruit Cindy M. , Nemanichvili Nikoloz , Okamatsu Masatoshi , Takematsu Hiromu , Boons Geert-Jan , de Vries Robert P.
Published: May 2021

The first step in influenza virus infection is the binding of hemagglutinin to sialic acid-containing glycans present on the cell surface. Over 50 different sialic acid modifications are known, of which N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) are the two main species. Animal models with α2,6 linked Neu5Ac in the upper respiratory tract, similar to humans, are preferred to enable and mimic infection with unadapted human influenza A viruses. Animal models that are currently most often used to study human influenza are mice and ferrets. Additionally, guinea pigs, cotton rats, Syrian hamsters, tree shrews, domestic swine, and non-human primates (macaques and marmosets) are discussed. The presence of NeuGc and the distribution of sialic acid linkages in the most commonly used models is summarized and experimentally determined. We also evaluated the role of Neu5Gc in infection using Neu5Gc binding viruses and cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH)−/− knockout mice, which lack Neu5Gc and concluded that Neu5Gc is unlikely to be a decoy receptor. This article provides a base for choosing an appropriate animal model. Although mice are one of the most favored models, they are hardly naturally susceptible to infection with human influenza viruses, possibly because they express mainly α2,3 linked sialic acids with both Neu5Ac and Neu5Gc modifications. We suggest using ferrets, which resemble humans closely in the sialic acid content, both in the linkages and the lack of Neu5Gc, lung organization, susceptibility, and disease pathogenesis.
CMV-Specific Cell-Mediated Immunity in Immunocompetent Adults with Primary CMV Infection: A Case Series and Review of the Literature
Authors: Chiereghin Angela , Verucchi Gabriella , Lazzarotto Tiziana
Published: May 2021

Cytomegalovirus-specific cell-mediated immunity (CMV-CMI) in actively infected healthy immunocompetent hosts has been poorly investigated. Conversely, correlates of maternal protective immunity for the fetus after primary infection in pregnancy continue to be studied. The kinetics and magnitude of CMV-specific CMI in immunocompetent primary CMV-infected adults are described. A literature review on CMV-CMI in primarily infected pregnant women and its correlation to the risk of vertical virus transmission is included. Immunological measurements after infection were performed by enzyme-linked ImmunoSPOT assay enumerating IFN-γ secreting CMV-specific T cells, at a single cell level, upon in vitro stimulation with viral antigens. Simultaneously, serological and virological profiles of infected patients were investigated. Patients displayed mild-to-moderate clinical and laboratory profiles for infection, and all showed positive EliSpot results in the early stage of infection (<20 days after onset). The virus-CMI was strong in the majority of patients (58.8%) in which the lowest CMV-DNAemia levels (<300 copies/mL) were detected. Significantly higher viral loads were observed in patients with weak CMV-CMI at the same time-point post-infection (up to 15,104 copies/mL; p < 0.001). T cell response magnitudes to IE-1 and pp65-UL83 peptides were overlapping and stable over time. In these case series, the early presence of CMV-CMI was probably pivotal in controlling viral replication and led to spontaneous viral clearance.
HCMV Antivirals and Strategies to Target the Latent Reservoir
Authors: Perera Marianne R. , Wills Mark R. , Sinclair John H.
Published: May 2021

Human cytomegalovirus (HCMV) is a ubiquitous human herpesvirus. In healthy people, primary infection is generally asymptomatic, and the virus can go on to establish lifelong latency in cells of the myeloid lineage. However, HCMV often causes severe disease in the immunosuppressed: transplant recipients and people living with AIDS, and also in the immunonaive foetus. At present, there are several antiviral drugs licensed to control HCMV disease. However, these are all faced with problems of poor bioavailability, toxicity and rapidly emerging viral resistance. Furthermore, none of them are capable of fully clearing the virus from the host, as they do not target latent infection. Consequently, reactivation from latency is a significant source of disease, and there remains an unmet need for treatments that also target latent infection. This review briefly summarises the most common HCMV antivirals used in clinic at present and discusses current research into targeting the latent HCMV reservoir.
Frontline Screening for SARS-CoV-2 Infection at Emergency Department Admission by Third Generation Rapid Antigen Test: Can We Spare RT-qPCR?
Authors: Cento Valeria , Renica Silvia , Matarazzo Elisa , Antonello Maria , Colagrossi Luna , Di Ruscio Federica , Pani Arianna , Fanti Diana , Vismara Chiara , Puoti Massimo , Scaglione Francesco , Perno Carlo , Alteri Claudia ,   on behalf of the S.Co.Va Study Group
Published: May 2021

To complement RT-qPCR testing for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, many countries have introduced the use of rapid antigen tests. As they generally display lower real-life performances than expected, their correct positioning as frontline screening is still controversial. Despite the lack of data from daily clinical use, third generation microfluidic assays (such as the LumiraDx SARS-CoV-2 Ag test) have recently been suggested to have similar performances to RT-qPCR and have been proposed as alternative diagnostic tools. By analyzing 960 nasopharyngeal swabs from 960 subjects at the emergency department admissions of a tertiary COVID-19 hospital, LumiraDx assay demonstrated a specificity of 97% (95% CI: 96–98), and a sensitivity of 85% (95% CI: 82–89) in comparison with RT-qPCR, which increases to 91% (95% CI: 86–95) for samples with a cycle threshold ≤ 29. Fifty false-negative LumiraDx-results were confirmed by direct quantification of genomic SARS-CoV-2 RNA through droplet-digital PCR (median (IQR) load = 5880 (1657–41,440) copies/mL). Subgenomic N and E RNAs were detected in 52% (n = 26) and 56% (n = 28) of them, respectively, supporting the presence of active viral replication. Overall, the LumiraDx test complies with the minimum performance requirements of the WHO. Yet, the risk of a misrecognition of patients with active COVID-19 persists, and the need for confirmatory RT-qPCR should not be amended.
The Effect of Early Postnatal Nutrition on Human T Cell Leukemia Virus Type 1 Mother-to-Child Transmission: A Systematic Review and Meta-Analysis
Authors: Miyazawa Tokuo , Hasebe Yoshiyuki , Murase Masahiko , Sakurai Motoichiro , Itabashi Kazuo , Yonemoto Naohiro
Published: May 2021

The main route of mother-to-child transmission (MTCT) of human T cell leukemia virus type 1 is vertical transmission via breastfeeding. Although the most reliable method for preventing MCTC is exclusive formula feeding (ExFF), short-term breastfeeding (STBF) or frozen–thawed breast milk feeding (FTBMF) has been offered as an alternative method if breastfeeding is strongly desired. The aim of this review was to clarify the pooled risk ratio of MCTC of STBF and FTBMF compared with ExFF. This study was registered with PROSPERO (number 42018087317). A literature search of PubMed, CINAHL, the Cochrane Database, EMBASE, and Japanese databases through September 2018 identified 1979 articles, 10 of which met the inclusion criteria. Finally, 11 articles, including these 10 studies and the report of a recent Japanese national cohort study, were included in the meta-analysis. The pooled relative risks of STBF ≤3 months, STBF ≤6 months, and FTBMF compared with ExFF were 0.72 (95% confidence interval (CI): 0.30–1.77; p = 0.48), 2.91 (95% CI: 1.69–5.03; p = 0.0001), and 1.14 (95% CI: 0.20–6.50; p = 0.88), respectively. This meta-analysis showed no statistical difference in the risk of MTCT between STBF ≤3 months and ExFF, but the risk of MTCT significantly increased in STBF ≤6 months.
Herpesvirus Regulation of Selective Autophagy
Authors: Vo Mai Tram , Choi Young Bong
Published: May 2021

Selective autophagy has emerged as a key mechanism of quality and quantity control responsible for the autophagic degradation of specific subcellular organelles and materials. In addition, a specific type of selective autophagy (xenophagy) is also activated as a line of defense against invading intracellular pathogens, such as viruses. However, viruses have evolved strategies to counteract the host’s antiviral defense and even to activate some proviral types of selective autophagy, such as mitophagy, for their successful infection and replication. This review discusses the current knowledge on the regulation of selective autophagy by human herpesviruses.
Structural Insights into the Human Astrovirus Capsid
Authors: Ykema Matthew , Tao Yizhi J.
Published: May 2021

Astroviruses (AstVs) are non-enveloped, positive single-stranded RNA viruses that cause a wide range of inflammatory diseases in mammalian and avian hosts. The T = 3 viral capsid is unique in its ability to infect host cells in a process driven by host proteases. Intercellular protease cleavages allow for viral egress from a cell, while extracellular cleavages allow for the virus to enter a new host cell to initiate infection. High-resolution models of the capsid core indicate a large, exposed region enriched with protease cleavage sites. The virus spike protein allows for binding to target cells and is the major target for naturally occurring and engineered neutralizing antibodies. During maturation, the capsid goes through significant structural changes including the loss of many surface spikes. The capsid interacts with host membranes during the virus life cycle at multiple stages such as assembly, host cell entry and exit. This review will cover recent findings and insights related to the structure of the capsid and its function. Further understanding of the viral capsid structure and maturation process can contribute to new vaccines, gastric therapeutics, and viral engineering applications.