bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Living Dental Pulp Cells in Direct Contact with Mineral Trioxide Aggregate
Authors: Hattori-Sanuki Tamaki , Karakida Takeo , Chiba-Ohkuma Risako , Miake Yasuo , Yamamoto Ryuji , Yamakoshi Yasuo , Hosoya Noriyasu
Published: October 2020

Mineral trioxide aggregate (MTA) was introduced as a material for dental endodontic regenerative therapy. Here, we show the dynamics of living dental pulp cells in direct contact with an MTA disk. A red fluorescence protein (DsRed) was introduced into immortalized porcine dental pulp cells (PPU7) and cloned. DsRed-PPU7 cells were cultured on the MTA disk and cell proliferation, chemotaxis, the effects of growth factors and the gene expression of cells were investigated at the biological, histomorphological and genetic cell levels. Mineralized precipitates formed in the DsRed-PPU7 cells were characterized with crystal structural analysis. DsRed-PPU7 cells proliferated in the central part of the MTA disk until Day 6 and displayed a tendency to move to the outer circumference. Both transforming growth factor beta and bone morphogenetic protein promoted the proliferation and movement of DsRed-PPU7 cells and also enhanced the expression levels of odontoblastic gene differentiation markers. Mineralized precipitates formed in DsRed-PPU7 were composed of calcium and phosphate but its crystals were different in each position. Our investigation showed that DsRed-PPU7 cells in direct contact with the MTA disk could differentiate into odontoblasts by controlling cell–cell and cell–substrate interactions depending on cell adhesion and the surrounding environment of the MTA.
Immersive Virtual Reality as Analgesia during Dressing Changes of Hospitalized Children and Adolescents with Burns: A Systematic Review with Meta-Analysis
Authors: Lauwens Yannick , Rafaatpoor Fatemeh , Corbeel Kobe , Broekmans Susan , Toelen Jaan , Allegaert Karel
Published: October 2020

Children and adolescents with severe burns require medical and nursing interventions, associated with pain. As immersive virtual reality (VR) gained prominence as non-pharmacological adjuvant analgesia, we conducted a systematic review and meta-analysis on the efficacy of full immersive VR on pain experienced during dressing changes in hospitalized children and adolescents with severe burns. This exercise included quality and risk of bias assessment. The systematic review resulted in eight studies and 142 patients. Due to missing data, four studies were excluded from the meta-analysis. Fixed effects meta-analysis of the four included studies (n = 104) revealed a large effect size (ES) (Standardized Mean Difference = 0.94; 95% Confidence Interval = 0.62, 1.27; Z = 5.70; p < 0.00001) for adjuvant full immersive VR compared to standard care (SC). In conclusion, adjuvant full immersive VR significantly reduces pain experienced during dressing changes in children and adolescents with burns. We therefore recommend implementing full immersive VR as an adjuvant in this specific setting and population. However, this requires further research into the hygienic use of VR appliances in health institutions. Furthermore, due to the high cost of the hardware, a cost–benefit analysis is required. Finally, research should also verify the long term physical and psychological benefits of VR.
Fire Rating of Post-Installed Anchors and Rebars
Authors: Mahrenholtz Philipp , Sharma Akanshu
Published: October 2020

Fire safety is a critical performance aspect of construction products, and post-installed anchors and rebars are no exemption in that regard. During their service life, anchors and rebars are subjected to different kinds of load actions, so they have to be qualified and designed for critical safety performance. While the qualification guidelines for static and seismic loading have matured to conclusive requirements over the past two decades, the requirements for determining the resistance to fire are just about to consolidate. This contribution strives to provide clarity on the fire rating of post-installed anchors and rebars. For this, the current status of the regulations, as well as the underlying background, is reviewed after a brief introduction. Typical examples of fire ratings in the field of post-installed anchors and rebars are given, and recent research undertaken to close the last regulative gaps is briefly presented.
Analysis of a Wide Range of Commercial Exterior Wood Coatings
Authors: Gibbons Michael J. , Nikafshar Saeid , Saravi Tina , Ohno Katie , Chandra Sanjeev , Nejad Mojgan
Published: October 2020

This study was focused on measuring the properties of twenty-three commercially available coatings formulated for exterior wood applications. The coatings were characterized by measuring their surface tension, solid content, viscosity, pH, and glass transition temperatures (Tg). Additionally, the wetting properties of coating droplets on wood substrates were measured. The contact angle of solvent-based and water-based coatings were characterized on untreated southern yellow pine wood samples using high-resolution image analysis and the Young–Laplace solution. An innovative image processing technique for determining the average diameter of coating droplets on wood was developed, and an iterative method to calculate the average contact angle using the Young–Laplace solution was applied. The water-resistance of the coated wood samples was evaluated during one week of water immersion tests. In general, solvent-based coatings had significantly lower contact angles and water uptake than water-based coatings. Water-based paint samples had the largest average contact angle (81°), and solvent-based transparent penetrating stains had the smallest contact angle (13.9°). A strong correlation was observed between the coating water uptake and their surface tension and solid content.
Effect of Ultrasound Irradiation on the Synthesis of Hydroxyapatite/Titanium Oxide Nanocomposites
Authors: Sánchez-Hernández A. K. , Martínez-Juárez J. , Gervacio-Arciniega J. J. , Silva-González R. , Robles-Águila M. J.
Published: October 2020

Bioceramic materials, such as hydroxyapatite, Ca10(PO4)6(OH)2, (HAp), can be chemically bound to bone tissue; since they are bioactive and biocompatible. HAp, titanium oxide (TiO2), and hydroxyapatite/titanium oxide (HAp/TiO2) nanocomposite nanoparticles were obtained by ultrasound irradiation assisted by sol-gel and co-precipitation methods at different time intervals, using Ca(NO3)2•4H2O, (NH4)2HPO4, and TiOSO4•xH2O as calcium, phosphorus, and titanium sources, respectively. HAp, TiO2, and HAp/TiO2 nanocomposite powders were characterized by X-ray Diffraction (XRD) and Raman Spectroscopy. The percentages of anatase phase for TiO2 and of monoclinic and hexagonal phases for HAp were quantified by Rietveld refinement. Furthermore, sample crystallinity in each material was enhanced by increasing the ultrasound irradiation time. The nanoparticle shape was semi-spherical, agglomerated, and between 17 and 20 nm in size. The agglomeration of particles in the samples was corroborated with a Field Emission Scanning Electron Microscope (FESEM).
Galectin-3 Plasma Levels Are Associated with Risk Profiles in Pulmonary Arterial Hypertension
Authors: Scelsi Laura , Ghio Stefano , Matrone Benedetta , Mannucci Letizia , Klersy Catherine , Valaperta Serenella , Turco Annalisa , Greco Alessandra , Derosa Giuseppe , Oltrona Visconti Luigi
Published: October 2020

Galectin-3 is a circulating biomarker of fibrosis whose prognostic role in pulmonary arterial hypertension (PAH) has not been fully explored. We undertook a pilot study to evaluate the relationship between galectin-3 plasma levels and validated risk scores in PAH. The study included 70 PAH patients admitted to a single referral center from June 2016 to June 2018. Patients were stratified according to the REVEAL 2.0 risk score, according to the parameters suggested by the European Society of Cardiology and European Respiratory Society (ESC/ERS) Guidelines, and according to a focused echocardiographic assessment of right heart performance. The association between galectin-3 levels and risk profiles was evaluated by generalized linear regression model with adjustment for etiology. Galectin-3 plasma levels increased linearly in the three risk strata based on the REVEAL 2.0 score (from 16.0 ± 5.7 in low-risk to 22.4 ± 6.3 in intermediate-risk and in 26.9 ± 7.7 ng/mL in high-risk patients (p for trend < 0.001). Galectin-3 levels were significantly lower in low-risk patients defined according to the prognostic parameters of ESC/ERS Guidelines (delta between low-risk and intermediate/high-risk = −9.3, 95% CI −12.8 to −5.8, p < 0.001, p < 0.001). Additionally, galectin-3 levels were lower in the low-risk profile defined on the basis of the echocardiographic evaluation of right heart performance (delta between low-risk and intermediate-/high-risk = −6.3, 95% CI −9.9 to −2.7, p = 0.001). Galectin-3 plasma levels are directly associated with several risk profiles in PAH patients. The prognostic role of this biomarker in PAH is worthwhile to be explored in larger prospective studies.
Complexity of Fracturing in Terms of Non-Extensive Statistical Physics: From Earthquake Faults to Arctic Sea Ice Fracturing
Authors: Vallianatos Filippos , Michas Georgios
Published: October 2020

Fracturing processes within solid Earth materials are inherently a complex phenomenon so that the underlying physics that control fracture initiation and evolution still remain elusive. However, universal scaling relations seem to apply to the collective properties of fracturing phenomena. In this article we present a statistical physics approach to fracturing based on the framework of non-extensive statistical physics (NESP). Fracturing phenomena typically present intermittency, multifractality, long-range correlations and extreme fluctuations, properties that motivate the NESP approach. Initially we provide a brief review of the NESP approach to fracturing and earthquakes and then we analyze stress and stress direction time series within Arctic sea ice. We show that such time series present large fluctuations and probability distributions with “fat” tails, which can exactly be described with the q-Gaussian distribution derived in the framework of NESP. Overall, NESP provide a consistent theoretical framework, based on the principle of entropy, for deriving the collective properties of fracturing phenomena and earthquakes.
Quantifying Information without Entropy: Identifying Intermittent Disturbances in Dynamical Systems
Authors: Montoya Angela , Habtour Ed , Moreu Fernando
Published: October 2020

A system’s response to disturbances in an internal or external driving signal can be characterized as performing an implicit computation, where the dynamics of the system are a manifestation of its new state holding some memory about those disturbances. Identifying small disturbances in the response signal requires detailed information about the dynamics of the inputs, which can be challenging. This paper presents a new method called the Information Impulse Function (IIF) for detecting and time-localizing small disturbances in system response data. The novelty of IIF is its ability to measure relative information content without using Boltzmann’s equation by modeling signal transmission as a series of dissipative steps. Since a detailed expression of the informational structure in the signal is achieved with IIF, it is ideal for detecting disturbances in the response signal, i.e., the system dynamics. Those findings are based on numerical studies of the topological structure of the dynamics of a nonlinear system due to perturbated driving signals. The IIF is compared to both the Permutation entropy and Shannon entropy to demonstrate its entropy-like relationship with system state and its degree of sensitivity to perturbations in a driving signal.
Strategies for Successful Learning with Geographical Comics: An Eye-Tracking Study with Young Learners
Authors: von Reumont Frederik , Budke Alexandra
Published: October 2020

Many studies report that comics are useful as learning material. However, there is little known about how learning with comics works. Based on previously established theories about multimedia learning, we conducted an eye-tracking experiment to examine learning about geography with a specially designed combination of comic and map which we call geo-comic. In our experiment, we show that our geo-comic fulfills many prerequisites for promoting deep learning. Thus, we establish guidelines for an effective design of geo-comics and recommend deploying comics in combination with maps in geography classes.
Direct and Indirect Effects of Literacy Skills and Writing Fluency on Writing Quality Across Three Genres
Authors: Troia Gary A. , Brehmer Julie S. , Glause Kaitlin , Reichmuth Heather L. , Lawrence Frank
Published: October 2020

Data were collected for this study early in the school year to analyze the direct and indirect effects of word-level literacy skills (word recognition, spelling, and written vocabulary use) and handwriting fluency on writing quality across three genres of typewritten papers. We further explored whether typing fluency and text generation fluency mediated the effects. Finally, we examined whether there was any difference in the effects across three writing genres. Fourth and fifth graders (N = 175) from 21 typical classrooms in 12 different Midwestern U.S. schools participated. Regression path analyses were employed and revealed that word-level literacy skills had both significant direct and serial indirect effects on quality, via typing fluency and then text generation fluency (text length) when controlling for handwriting fluency. Further, handwriting fluency had no direct effect when controlling for word-level literacy skills but did have a significant serial indirect effect on writing quality via typing fluency then text generation fluency. Results indicate that handwriting fluency matters, even when composing on the computer. Stronger transcription fluency, particularly by hand, leads to higher quality writing, likely because less cognitive effort is devoted to transcription. This study adds to limited research on the cross-modal effects of transcription on writing quality.
“Let’s Talk about It”—Explicit Discussions as a Way to Reduce the Resistance of Religious Jewish Science Teachers to Learning and Teaching about Evolution: A Case Study
Authors: Alkaher Iris , Shmueli Marva , Dreyfus Amos
Published: October 2020

Acknowledging the diverse perceptions about science–religion relationships among learners who come from various religious environments may increase learners’ willingness to learn about evolution. This study is based on a zoology course designed for in-service teachers, which aimed to provide basic scientific knowledge about evolution using the Religious Cultural Competence in Evolution Education framework. The study explores whether learners who were resistant to evolution modify their attitudes and willingness to learn about it, and whether they develop respect toward learners who hold contradicting views. Using qualitative methods, the findings indicate that using the Religious Cultural Competence in Evolution Education framework increased some formerly “resistant” learners’ willingness to learn about evolution and include it in their own teaching, albeit in varying degrees and with various reservations. The learners appreciated the freedom to express their challenges concerning evolution learning or teaching and became more willing to respect opposing perspectives, even though not all the religious learners accepted evolution as an explanation for the development of organisms. This study has international implications for bridging the gap between science and religion, thus reducing resistance to learning and teaching about evolution.
An Active and Passive Hybrid Battery Equalization Strategy Used in Group and between Groups
Authors: Gao Mingyu , Qu Jifeng , Lan Hao , Wu Qixing , Lin Huipin , Dong Zhekang , Zhang Weizhong
Published: October 2020

Active battery equalization and passive battery equalization are two important methods which can solve the inconsistency of battery cells in lithium battery groups. In this paper, a new hybrid battery equalization strategy combinfigureing the active equalizing method with a passive equalizing method is proposed. Among them, the implementation of the active equalizing method uses the bidirectional Flyback converter and Forward converter. This hybrid equalizing strategy adopts the concept of hierarchical equilibrium: it can be divided into two layers, the top layer is the equalization between groups, and the bottom layer is the equalization of group. There are three active equilibrium strategies and one passive equilibrium strategy. For verification purposes, a series of experiments were conducted in MATLAB 2018b/Simulink platform. The simulation and experiment results show that this hybrid battery equalizing method is efficient and feasible.
Real-Time Remote Health Monitoring System Driven by 5G MEC-IoT
Authors: Zhang Yangan , Chen Guichen , Du Hang , Yuan Xueguang , Kadoch Michel , Cheriet Mohamed
Published: October 2020

Telemedicine over Internet of Things (IoT) generates an unprecedented amount of data, which further requires transmission, analysis, and storage. Deploying cloud computing to handle data of this magnitude will introduce unacceptable data analysis latency and high storage costs. Thus, mobile edge computing (MEC) deployed between the cloud and users, which is close to the nodes of data generation, can tackle these problems in 5G scenarios with the help of artificial intelligence. This paper proposes a telemedicine system based on MEC and artificial intelligence for remote health monitoring and automatic disease diagnosis. The integration of different technologies such as computers, medicine, and telecommunications will significantly improve the efficiency of patient treatment and reduce the cost of health care.
Energy Harvesting towards Self-Powered IoT Devices
Authors: Elahi Hassan , Munir Khushboo , Eugeni Marco , Atek Sofiane , Gaudenzi Paolo
Published: October 2020

The internet of things (IoT) manages a large infrastructure of web-enabled smart devices, small devices that use embedded systems, such as processors, sensors, and communication hardware to collect, send, and elaborate on data acquired from their environment. Thus, from a practical point of view, such devices are composed of power-efficient storage, scalable, and lightweight nodes needing power and batteries to operate. From the above reason, it appears clear that energy harvesting plays an important role in increasing the efficiency and lifetime of IoT devices. Moreover, from acquiring energy by the surrounding operational environment, energy harvesting is important to make the IoT device network more sustainable from the environmental point of view. Different state-of-the-art energy harvesters based on mechanical, aeroelastic, wind, solar, radiofrequency, and pyroelectric mechanisms are discussed in this review article. To reduce the power consumption of the batteries, a vital role is played by power management integrated circuits (PMICs), which help to enhance the system’s life span. Moreover, PMICs from different manufacturers that provide power management to IoT devices have been discussed in this paper. Furthermore, the energy harvesting networks can expose themselves to prominent security issues putting the secrecy of the system to risk. These possible attacks are also discussed in this review article.
Comparison of Performance-Assessment Methods for Residential PV Battery Systems
Authors: Niedermeyer Fabian , Braun Martin
Published: October 2020

Declining costs for high-performance batteries are leading to a global increased use of storage systems in residential buildings. Especially in conjunction with reduced photovoltaic (PV) feed-in tariffs, a large market has been developed for PV battery systems to increase self-sufficiency. They differ in the type of coupling between PV and battery, the nominal capacities of their components, and their degree of integration. High system performance is particularly important to achieve profitability for the operator. This paper presents and evaluates methods for a uniform determination of PV battery system performance. Already the requirement analysis reveals that a performance comparison of PV battery systems must cover the efficiency and effectiveness during system operation. A method based on a derivation of key performance indicators (KPIs) for these two criteria through an application test is proposed. It is evaluated by comparison to other methods, such as the System Performance Index (SPI) and aggregation of conversion and storage efficiency. These methods are applied with five systems in a laboratory test bench to identify their advantages and drawbacks. Here, a particular focus is on compliance with the initially formulated requirements in terms of both test procedures and KPI derivations. Analysis revealed that the proposed method addresses these requirements well, and is beneficial in terms of result comprehensibility and KPI validity.
Experimental Study of Harmonic Influence on Electrical Energy Metering
Authors: Shklyarskiy Yaroslav , Hanzelka Zbigniew , Skamyin Aleksandr
Published: October 2020

The paper considers the influence of harmonics on the operating of electrical energy meters in a network with nonlinear loads. It is shown that electronic static meters of active energy are tested in the presence of distortions, and electronic static meters of reactive energy accuracy requirements do not take into account the possible presence of harmonics. It is revealed that the maximum influence on the error in active energy metering is exerted by the number of harmonics taken into account and their amplitude, and the error in reactive energy metering is additionally influenced by the phase angle at the fundamental and harmonic frequencies, which has been confirmed in laboratory conditions. Additionally, experimental studies of the capacitor bank’s influence on reactive energy metering has been carried out in the presence of nonlinear electrical loads. It is shown that when capacitor banks are connected, the error in reactive energy measurement and variation range of the phase shift angle of harmonics significantly increases. The assessment of the computational error of reactive power metering according to various equations were carried out based on the field measurements. If the voltage and current distortion values do not exceed the permissible values, the error can be estimated at, at most, 5–7%.
Corrosion Behavior of Al in Ethanol–Gasoline Blends
Authors: Brito-Franco Alfredo , Uruchurtu Jorge , Rosales-Cadena Isai , Lopez-Sesenes Roy , Serna-Barquera Sergio Alonso , Hernandez-Perez Jose Alfredo , Rocabruno-Valdes Caroline , Gonzalez-Rodriguez Jose Gonzalo
Published: October 2020

The corrosion behavior of pure aluminum (Al) in 20 v/v% ethanol–gasoline blends has been studied using electrochemical techniques. Ethanol was obtained from different fruits including sugar cane, oranges, apples, or mangos, whereas other techniques included lineal polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy for 90 days. Results have shown that corrosion rates for Al in all the blends were higher than that obtained in gasoline. In addition, the highest corrosion rate was obtained in the blend containing ethanol obtained from sugar cane. The corrosion process was under charge transfer control in all blends; however, for some exposure times, it was under the adsorption/desorption control of an intermediate compound. Al was susceptible to a localized, plotting type of corrosion in all blends, but they were bigger in size and in number in the blend containing ethanol obtained from sugar cane.
From Economic to Extrinsic Values of Sustainable Energy: Prestige, Neo-Rentierism, and Geopolitics of the Energy Transition in the Arabian Peninsula
Authors: Al-Saidi Mohammad
Published: October 2020

Energy transition in the region of the Gulf Cooperation Countries (GCC) has recently commenced and is now being implemented through large-scale renewable projects, nuclear plants, and energy efficiency measures in the built environment. This paper highlights how alternative energies are associated with non-economic factors such as prestige, modernity, and (soft or symbolic) power. It analyzes the specific ways of delivering energy diversification in the Gulf through renewable megaprojects, the reorganization of the energy sector, and the incorporation of nuclear energy as an add-on source. These decisions serve GCC states in showcasing modernity, maintaining centralized control, posturing geopolitically, and extending the rent distribution mechanisms. On one hand, the energy transition in the Gulf has been domesticated through policies and strategies suiting the political systems in the region. This can have an acceleration effect on this transition. On the other hand, the implications of the adaptation of the energy transition to the reality of the Gulf remain open. The success of this transition will depend on the ability of GCC states to ecologically modernize the Gulf societies, reduce environmental risks, and enhance GCC-wide cooperation.
An Overview of Applications of the Modular Multilevel Matrix Converter
Authors: Diaz Matias , Cárdenas Dobson Roberto , Ibaceta Efrain , Mora Andrés , Urrutia Matias , Espinoza Mauricio , Rojas Felix , Wheeler Patrick
Published: October 2020

The modular multilevel matrix converter is a relatively new power converter topology suitable for high-power alternating current (AC)-to-AC applications. Several publications in the literature have highlighted the converter capabilities, such as full modularity, fault-redundancy, control flexibility and input/output power quality. However, the topology and control of this converter are relatively complex to realise, considering that the converter has a large number of power-cells and floating capacitors. To the best of the authors’ knowledge, there are no review papers where the applications of the modular multilevel matrix converter are discussed. Hence, this paper aims to provide a comprehensive review of the state-of-the-art of the modular multilevel matrix converter, focusing on implementation issues and applications. Guidelines to dimensioning the key components of this converter are described and compared to other modular multilevel topologies, highlighting the versatility and controllability of the converter in high-power applications. Additionally, the most popular applications for the modular multilevel matrix converter, such as wind turbines, grid connection and motor drives, are discussed based on analyses of simulation and experimental results. Finally, future trends and new opportunities for the use of the modular multilevel matrix converter in high-power AC-to-AC applications are identified.
Individual Cylinder Combustion Optimization to Improve Performance and Fuel Consumption of a Small Turbocharged SI Engine
Authors: Marchitto Luca , Tornatore Cinzia , Teodosio Luigi
Published: October 2020

Stringent exhaust emission and fuel consumption regulations impose the need for new solutions for further development of internal combustion engines. With this in mind, a refined control of the combustion process in each cylinder can represent a useful and affordable way to limit cycle-to-cycle and cylinder-to-cylinder variation reducing CO2 emission. In this paper, a twin-cylinder turbocharged Port Fuel Injection–Spark Ignition engine is experimentally and numerically characterized under different operating conditions in order to investigate the influence of cycle-to-cycle variation and cylinder-to-cylinder variability on the combustion and performance. Significant differences in the combustion behavior between cylinders were found, mainly due to a non-uniform effective in-cylinder air/fuel (A/F) ratio. For each cylinder, the coefficients of variation (CoVs) of selected combustion parameters are used to quantify the cyclic dispersion. Experimental-derived CoV correlations representative of the engine behavior are developed, validated against the measurements in various speed/load points and then coupled to an advanced 1D model of the whole engine. The latter is employed to reproduce the experimental findings, taking into account the effects of cycle-to-cycle variation. Once validated, the whole model is applied to optimize single cylinder operation, mainly acting on the spark timing and fuel injection, with the aim to reduce the specific fuel consumption and cyclic dispersion.
An Overview of MnAl Permanent Magnets with a Study on Their Potential in Electrical Machines
Authors: Kontos Sofia , Ibrayeva Anar , Leijon Jennifer , Mörée Gustav , Frost Anna E. , Schönström Linus , Gunnarsson Klas , Svedlindh Peter , Leijon Mats , Eriksson Sandra
Published: October 2020

In this paper, hard magnetic materials for future use in electrical machines are discussed. Commercialized permanent magnets used today are presented and new magnets are reviewed shortly. Specifically, the magnetic MnAl compound is investigated as a potential material for future generator designs. Experimental results of synthesized MnAl, carbon-doped MnAl and calculated values for MnAl are compared regarding their energy products. The results show that the experimental energy products are far from the theoretically calculated values with ideal conditions due to microstructure-related reasons. The performance of MnAl in a future permanent magnet (PM) generator is investigated with COMSOL, assuming ideal conditions. Simplifications, such as using an ideal hysteresis loop based on measured and calculated saturation magnetization values were done for the COMSOL simulation. The results are compared to those for a ferrite magnet and an NdFeB magnet. For an ideal MnAl hysteresis loop, it would be possible to replace ferrite with MnAl, with a reduced weight compared to ferrite. In conclusion, future work for simulations with assumptions and results closer to reality is suggested.
Initial Inoculum and the Severity of COVID-19: A Mathematical Modeling Study of the Dose-Response of SARS-CoV-2 Infections
Authors: Fain Baylor , Dobrovolny Hana M.
Published: October 2020

SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) causes a variety of responses in those who contract the virus, ranging from asymptomatic infections to acute respiratory failure and death. While there are likely multiple mechanisms triggering severe disease, one potential cause of severe disease is the size of the initial inoculum. For other respiratory diseases, larger initial doses lead to more severe outcomes. We investigate whether there is a similar link for SARS-CoV-2 infections using the combination of an agent-based model (ABM) and a partial differential equation model (PDM). We use the model to examine the viral time course for different sizes of initial inocula, generating dose-response curves for peak viral load, time of viral peak, viral growth rate, infection duration, and area under the viral titer curve. We find that large initial inocula lead to short infections, but with higher viral titer peaks; and that smaller initial inocula lower the viral titer peak, but make the infection last longer.
Nursery Cultural Techniques Facilitate Restoration of Acacia koa Competing with Invasive Grass in a Dry Tropical Forest
Authors: Jacobs Douglass F. , Davis Anthony S. , Dumroese R. Kasten , Burney Owen T.
Published: October 2020

Anthropogenic activity has caused persistent and prominent losses of forest cover in dry tropical forests. Natural regeneration of forest trees in grazed areas often fails due to lack of seed sources and consumption by ungulates. To address this, the effective restoration of such sites often requires fencing and outplanting nursery-grown seedlings. In the degraded, dry forests of tropical Hawaii, USA, an additional challenge to restoration of native forest trees is the introduced kikuyu grass (Cenchrus clandestinus). This invasive, rapidly growing rhizomatous plant forms deep, dense mats. We studied the use of nursery cultural techniques to facilitate the establishment of koa (Acacia koa) seedlings outplanted amidst well-established kikuyu grass on a volcanic cinder cone on the dry, western side of Hawaii Island. Seedlings were grown four months in three container sizes (49, 164, 656 cm3) and with four rates (0, 4.8, 7.2, and 9.6 kg m−3) of 15–9–12 (NPK) controlled-release fertilizer incorporated into media prior to sowing. After 16 months in the field, seedling survival was > 80% for all treatments with two exceptions: the non-fertilized 49 cm3 (78%) and 164 cm3 (24%) containers. After 10 years, only these two treatments had significantly lower survival (35% and 10%, respectively) than the other treatments. One year following planting, none of the non-fertilized seedlings had transitioned to phyllodes from juvenile true leaves, regardless of container size. For the fertilized 656 cm3 container treatment, 78%–85% of seedlings had phyllodes, with mean values increasing by fertilizer rate. Phyllodes are known to confer greater drought resistance than true leaves in koa, which may help to explain the improved survival of fertilized trees on this relatively dry site. Overall, nursery fertilization was more influential on seedling height and diameter response than container size after outplanting. However, the largest container (656 cm3) with the addition of fertilizer, produced significantly larger trees than all other treatments during the early regeneration phase; early growth differences tended to fade at 10 years due to inter-tree canopy competition. Although koa is able to fix atmospheric nitrogen through rhizobium associations, our data confirm the importance of nursery fertilization in promoting regeneration establishment. Nursery cultural techniques may play an important role in forest restoration of dry tropical sites invaded by exotic vegetation.
Learning a Hierarchical Global Attention for Image Classification
Authors: Cao Kerang , Gao Jingyu , Choi Kwang-nam , Duan Lini
Published: October 2020

To classify the image material on the internet, the deep learning methodology, especially deep neural network, is the most optimal and costliest method of all computer vision methods. Convolutional neural networks (CNNs) learn a comprehensive feature representation by exploiting local information with a fixed receptive field, demonstrating distinguished capacities on image classification. Recent works concentrate on efficient feature exploration, which neglect the global information for holistic consideration. There is large effort to reduce the computational costs of deep neural networks. Here, we provide a hierarchical global attention mechanism that improve the network representation with restricted increase of computation complexity. Different from nonlocal-based methods, the hierarchical global attention mechanism requires no matrix multiplication and can be flexibly applied in various modern network designs. Experimental results demonstrate that proposed hierarchical global attention mechanism can conspicuously improve the image classification precision—a reduction of 7.94% and 16.63% percent in Top 1 and Top 5 errors separately—with little increase of computation complexity (6.23%) in comparison to competing approaches.
Application of a Semi-Empirical Dynamic Model to Forecast the Propagation of the COVID-19 Epidemics in Spain
Authors: Mora Juan Carlos , Pérez Sandra , Dvorzhak Alla
Published: October 2020

A semiempirical model, based in the logistic map, was developed to forecast the different phases of the COVID-19 epidemic. This paper shows the mathematical model and a proposal for its calibration. Specific results are shown for Spain. Four phases were considered: non-controlled evolution; total lock-down; partial easing of the lock-down; and a phased lock-down easing. For no control the model predicted the infection of a 25% of the Spanish population, 1 million would need intensive care and 700,000 direct deaths. For total lock-down the model predicted 194,000 symptomatic infected, 85,700 hospitalized, 8600 patients needing an Intensive Care Unit (ICU) and 19,500 deaths. The peak was predicted between the 29 March/3 April. For the third phase, with a daily rate r=1.03, the model predicted 400,000 infections and 46,000±15,000 deaths. The real r was below 1%, and a revision with updated parameters provided a prediction of 250,000 infected and 29,000±15,000 deaths. The reported values by the end of May were 282,870 infected and 28,552 deaths. After easing of the lock-down the model predicted that the health system would not saturate if r was kept below 1.02. This model provided good accuracy during epidemics development.
Extracapsular Extension Does Not Decrease Overall Survival in Rectal Cancer Patients with Lymph Node Metastasis Following Neoadjuvant Chemoradiotherapy
Authors: Lino-Silva Leonardo , Sánchez-Acosta Carmen , Salcedo-Hernández Rosa , Zepeda-Najar César
Published: October 2020

Background. The Tumor-Node-Metastasis system does not include additional prognostic factors present in the Lymph Node Metastasis (LNM) such as extra-capsular extension (ECE), which is associated with decreased survival. There are not studies addressing this topic in rectal cancer patients with preoperative chemoradiotherapy (nCRT) and total mesorectal excision (TME). Aim. We aimed to examine the survival influence of ECE in patients with stage III rectal cancer who received nCRT followed by surgery. Methods. A retrospective study of 126 patients prospectively collected with rectal cancer in clinical stage III rated with nCRT and TME from 2010 to 2015 was performed. Results. In total, 71.6% of cases had 1 to 3 lymph node metastases, most tumors were grade 2 (52.4%), 25.4% had good pathologic response, 77.8% had a good quality TME, and the median tumor budding count was 4/0.785 mm2. Forty-four (34.9%) patients had ECE+, which was associated with a higher nodal stage (pN2), perineural invasion and a higher lymph node retrieval. The factors associated with the survival were a higher pathologic T stage, higher pathological N stage, high-grade tumors, and perineural invasion. The ECE did not decrease the 5–year survival with a similar median survival (86.5 months for the ECE+ group vs. 84.1 for the ECE–). Conclusion. Our results demonstrate that ECE has no impact on overall survival in rectal cancer patients who received nCRT and this was independent of nodal stage or number of lymph nodes examined.
Characterization of Zinc Oxide Nanoparticle Cross-Linked Collagen Hydrogels
Authors: Agban Yosra , Mugisho Odunayo O. , Thakur Sachin S. , Rupenthal Ilva D.
Published: October 2020

Collagen is the most abundant protein in mammals and possesses high biocompatibility and low antigenicity. These biological properties render it one of the most useful biomaterials for medical applications. This study investigated the mechanical and physical characteristics of collagen hydrogels cross-linked with different ratios of polyvinylpyrrolidone capped zinc oxide nanoparticles (ZPVP). Fourier transform infrared spectroscopy indicated molecular interactions between collagen fibers and ZPVP. Texture analysis revealed a significant increase in gel hardness, adhesiveness, and viscosity after cross-linking with ZPVP. Rheological measurements showed that as the ratio of ZPVP increased, stronger hydrogels were formed which in turn resulted in more sustained release of the model drug, dexamethasone sodium phosphate. We can therefore conclude that the mechanical properties of collagen hydrogels can be modified by controlling the ratio of ZPVP used for cross-linking, offering the potential to develop biocompatible sustained release drug delivery systems.
Identification of Novel Interspersed DNA Repetitive Elements in the Trypanosoma cruzi Genome Associated with the 3′UTRs of Surface Multigenic Families
Authors: Calderano Simone Guedes , Nishiyama Junior Milton Yutaka , Marini Marjorie , Nunes Nathan de Oliveira , Reis Marcelo da Silva , Patané José Salvatore Leister , da Silveira José Franco , da Cunha Julia Pinheiro Chagas , Elias Maria Carolina
Published: October 2020

Trypanosoma cruzi is the etiological agent of Chagas disease, which affects millions of people in Latin America. No transcriptional control of gene expression has been demonstrated in this organism, and 50% of its genome consists of repetitive elements and members of multigenic families. In this study, we applied a novel bioinformatics approach to predict new repetitive elements in the genome sequence of T. cruzi. A new repetitive sequence measuring 241 nt was identified and found to be interspersed along the genome sequence from strains of different DTUs. This new repeat was mostly on intergenic regions, and upstream and downstream regions of the 241 nt repeat were enriched in surface protein genes. RNAseq analysis revealed that the repeat was part of processed mRNAs and was predominantly found in the 3′ untranslated regions (UTRs) of genes of multigenic families encoding surface proteins. Moreover, we detected a correlation between the presence of the repeat in the 3′UTR of multigenic family genes and the level of differential expression of these genes when comparing epimastigote and trypomastigote transcriptomes. These data suggest that this sequence plays a role in the posttranscriptional regulation of the expression of multigenic families.
Multigene Expression Assay for Assessment of the Immune Status of Atlantic Salmon
Authors: Krasnov Aleksei , Afanasyev Sergey , Nylund Stian , Rebl Alexander
Published: October 2020

We report the development of a multigene gene expression assay on the BioMark HD platform for the evaluation of immune competence (ImCom) in farmed Atlantic salmon. The first version of the assay included 92 genes selected on the basis of transcriptome analyses in 54 trials that challenged the immune system; annotations were taken into account to represent the key pathways of innate and adaptive immunity. ImCom was tested on samples collected from seven independent projects. Fish were reared from the start feeding to eight months in the sea at eight units in different parts of Norway. Several tissues were analyzed. Linear discriminant analysis (LDA) showed that no more than 10 genes were required to separate groups, and a set of 46 immune genes was sufficient for any task. The second version of the assay was tested in the gills of two groups of high-performing healthy smolts and in groups with intermediate and high mortality rates (IM and HM, respectively). A set of 645 gill samples from clinically healthy Atlantic salmon was used as a reference. The IM group showed general suppression of immunity. All HM group salmon were above the threshold by the squared deviation from the reference. This group showed marked upregulation of genes involved in acute stress and inflammation: mmp-9, mmp-13, hsp70, il-1b, lect2, and cathelicidin. Further work will clarify the boundaries of the norm and explore various cases of impaired immunity.
A Mild Phenotype Caused by Two Novel Compound Heterozygous Mutations in CEP290
Authors: Rafalska Agnieszka , Tracewska Anna M. , Turno-Kręcicka Anna , Szafraniec Milena J. , Misiuk-Hojło Marta
Published: October 2020

CEP290 is a ciliary gene frequently mutated in ciliopathies, resulting in a broad range of phenotypes, ranging from isolated inherited retinal disorders (IRDs) to severe or lethal syndromes with multisystemic involvement. Patients with non-syndromic CEP290-linked disease experience profound and early vision loss due to cone-rod dystrophy, as in Leber congenital amaurosis. In this case report, we describe two novel loss-of-function heterozygous alterations in the CEP290 gene, discovered in a patient suffering from retinitis pigmentosa using massive parallel sequencing of a molecular inversion probes library constructed for 108 genes involved in IRDs. A milder phenotype than expected was found in the individual, which serves to prove that some CEP290-associated disorders may display preserved cone function.
Genetic Variants Associated with Non-Alcoholic Fatty Liver Disease Do Not Associate with Measures of Sub-Clinical Atherosclerosis: Results from the IMPROVE Study
Authors: Castaldo Luigi , Laguzzi Federica , Strawbridge Rona J. , Baldassarre Damiano , Veglia Fabrizio , Vigo Lorenzo , Tremoli Elena , de Faire Ulf , Eriksson Per , Smit Andries J. , Aubrecht Jiri , Leander Karin , Pirro Matteo , Giral Philippe , Ritieni Alberto , Di Minno Giovanni , Mälarstig Anders , Gigante Bruna
Published: October 2020

Non-alcoholic fatty liver disease (NAFLD) and atherosclerosis-related cardiovascular diseases (CVD) share common metabolic pathways. We explored the association between three NAFLD-associated single nucleotide polymorphisms (SNPs) rs738409, rs10401969, and rs1260326 with sub-clinical atherosclerosis estimated by the carotid intima-media thickness (c-IMT) and the inter-adventitia common carotid artery diameter (ICCAD) in patients free from clinically overt NAFLD and CVD. The study population is the IMPROVE, a multicenter European study (n = 3711). C-IMT measures and ICCAD were recorded using a standardized protocol. Linear regression with an additive genetic model was used to test for association of the three SNPs with c-IMT and ICCAD. In secondary analyses, the association of the three SNPs with c-IMT and ICCAD was tested after stratification by alanine aminotransferase levels (ALT). No associations were found between rs738409, rs1260326, rs10401969, and c-IMT or ICCAD. Rs738409-G and rs10401969-C were associated with ALT levels (p < 0.001). In patients with ALT levels above 28 U/L (highest quartile), we observed an association between rs10401969-C and c-IMT measures of c-IMTmax and c-IMTmean-max (p = 0.018 and 0.021, respectively). In conclusion, NAFLD-associated SNPs do not associate with sub-clinical atherosclerosis measures. However, our results suggest a possible mediating function of impaired liver function on atherosclerosis development.
Expression Quantitative Trait Locus Mapping in Pulmonary Arterial Hypertension
Authors: Ulrich Anna , Otero-Núñez Pablo , Wharton John , Swietlik Emilia M. , Gräf Stefan , Morrell Nicholas W. , Wang Dennis , Lawrie Allan , Wilkins Martin R. , Prokopenko Inga , Rhodes Christopher J. , on behalf of The NIHR BioResource—Rare Diseases Consortium  , UK PAH Cohort Study Consortium
Published: October 2020

Expression quantitative trait loci (eQTL) can provide a link between disease susceptibility variants discovered by genetic association studies and biology. To date, eQTL mapping studies have been primarily conducted in healthy individuals from population-based cohorts. Genetic effects have been known to be context-specific and vary with changing environmental stimuli. We conducted a transcriptome- and genome-wide eQTL mapping study in a cohort of patients with idiopathic or heritable pulmonary arterial hypertension (PAH) using RNA sequencing (RNAseq) data from whole blood. We sought confirmation from three published population-based eQTL studies, including the GTEx Project, and followed up potentially novel eQTL not observed in the general population. In total, we identified 2314 eQTL of which 90% were cis-acting and 75% were confirmed by at least one of the published studies. While we observed a higher GWAS trait colocalization rate among confirmed eQTL, colocalisation rate of novel eQTL reported for lung-related phenotypes was twice as high as that of confirmed eQTL. Functional enrichment analysis of genes with novel eQTL in PAH highlighted immune-related processes, a suspected contributor to PAH. These potentially novel eQTL specific to or active in PAH could be useful in understanding genetic risk factors for other diseases that share common mechanisms with PAH.