bluuebunny/crossref_metadata_2025 huggingface dataset:
Facing the New Situation of Religious Education in Iceland
Authors: Gunnarsson Gunnar J.
Published: October 2020

Over the last two decades, Iceland has faced rapid societal changes in many ways, and cultural and religious diversity has grown faster than ever before. This has influenced the curricula of religious education. In 2011/2013, drastic changes were made to the National Curriculum Guide, and the curricula of individual subjects were merged into larger entities. Religious education thus became a part of the social studies curriculum, together with history, geography, sociology, life skills, ethics and philosophy. The aim of this article is to explore and discuss the influences of the societal changes in Iceland on religious education in compulsory schools. As little research exists on the consequences of the changes made to the curriculum for the practice of religious education, the focus will also be on some of the research that can shed light on the changing conditions of religious education in Iceland, such as Icelanders’ attitudes towards religion, and parents’ attitudes towards religious education in compulsory school. Particular attention will be paid to research into young people’s views towards the growing cultural and religious diversity in Iceland. The aim is to understand better the new situation of religious education in Iceland and the changes that have been made to the National Curriculum Guide.
Comparing Two Different Option Pricing Methods
Authors: Bondi Alessandro , Radojičić Dragana , Rheinländer Thorsten
Published: October 2020

Motivated by new financial markets where there is no canonical choice of a risk-neutral measure, we compared two different methods for pricing options: calibration with an entropic penalty term and valuation by the Esscher measure. The main aim of this paper is to contrast the outcomes of those two methods with real-traded call option prices in a liquid market like NASDAQ stock exchange, using data referring to the period 2019–2020. Although the Esscher measure method slightly underperforms the calibration method in terms of absolute values of the percentage difference between real and model prices, it could be the only feasible choice if there are not many liquidly traded derivatives in the market.
The Linear Link: Deriving Age-Specific Death Rates from Life Expectancy
Authors: Pascariu Marius , Basellini Ugofilippo , Aburto José , Canudas-Romo Vladimir
Published: October 2020

The prediction of human longevity levels in the future by direct forecasting of life expectancy offers numerous advantages, compared to methods based on extrapolation of age-specific death rates. However, the reconstruction of accurate life tables starting from a given level of life expectancy at birth, or any other age, is not straightforward. Model life tables have been extensively used for estimating age patterns of mortality in poor-data countries. We propose a new model inspired by indirect estimation techniques applied in demography, which can be used to estimate full life tables at any point in time, based on a given value of life expectancy at birth. Our model relies on the existing high correlations between levels of life expectancy and death rates across ages. The methods presented in this paper are implemented in a publicly available R package.
(Quasi-)Real-Time Inversion of Airborne Time-Domain Electromagnetic Data via Artificial Neural Network
Authors: Bai Peng , Vignoli Giulio , Viezzoli Andrea , Nevalainen Jouni , Vacca Giuseppina
Published: October 2020

The possibility to have results very quickly after, or even during, the collection of electromagnetic data would be important, not only for quality check purposes, but also for adjusting the location of the proposed flight lines during an airborne time-domain acquisition. This kind of readiness could have a large impact in terms of optimization of the Value of Information of the measurements to be acquired. In addition, the importance of having fast tools for retrieving resistivity models from airborne time-domain data is demonstrated by the fact that Conductivity-Depth Imaging methodologies are still the standard in mineral exploration. In fact, they are extremely computationally efficient, and, at the same time, they preserve a very high lateral resolution. For these reasons, they are often preferred to inversion strategies even if the latter approaches are generally more accurate in terms of proper reconstruction of the depth of the targets and of reliable retrieval of true resistivity values of the subsurface. In this research, we discuss a novel approach, based on neural network techniques, capable of retrieving resistivity models with a quality comparable with the inversion strategy, but in a fraction of the time. We demonstrate the advantages of the proposed novel approach on synthetic and field datasets.
Towards DCS in the UV Spectral Range for Remote Sensing of Atmospheric Trace Gases
Authors: Galtier Sandrine , Pivard Clément , Rairoux Patrick
Published: October 2020

The development of increasingly sensitive and robust instruments and new methodologies are essential to improve our understanding of the Earth’s climate and air pollution. In this context, Dual-Comb spectroscopy (DCS) has been successfully demonstrated as a remote laser-based instrument to probe infrared absorbing species such as greenhouse gases. We present here a study of the sensitivity of Dual-Comb spectroscopy to remotely monitor atmospheric gases focusing on molecules that absorb in the ultraviolet domain, where the most reactive molecules of the atmosphere (OH, HONO, BrO...) have their highest absorption cross-sections. We assess the achievable signal-to-noise ratio (SNR) and the corresponding minimum absorption sensitivity of DCS in the ultraviolet range. We propose a potential light source for remote sensing UV-DCS and discuss the degree of immunity of UV-DCS to atmospheric turbulences. We show that the characteristics of the currently available UV sources are compatible with the unambiguous identification of UV absorbing gases by UV-DCS.
Thick Cloud Removal of Remote Sensing Images Using Temporal Smoothness and Sparsity Regularized Tensor Optimization
Authors: Duan Chenxi , Pan Jun , Li Rui
Published: October 2020

In remote sensing images, the presence of thick cloud accompanying shadow can affect the quality of subsequent processing and limit the scenarios of application. Hence, to make good use of such images, it is indispensable to remove the thick cloud and cloud shadow as well as recover the cloud-contaminated pixels. Generally, the thick cloud and cloud shadow element are not only sparse but also smooth along the spatial horizontal and vertical direction, while the clean element is smooth along the temporal direction. Guided by the above insight, a novel thick cloud removal method for remote sensing images based on temporal smoothness and sparsity regularized tensor optimization (TSSTO) is proposed in this paper. Firstly, the sparsity norm is utilized to boost the sparsity of the cloud and cloud shadow element, and unidirectional total variation (UTV) regularizers are applied to ensure the smoothness in different directions. Then, through thresholding, the cloud mask and the cloud shadow mask can be acquired and used to guide the substitution. Finally, the reference image is selected to reconstruct details of the repairing area. A series of experiments are conducted both on simulated and real cloud-contaminated images from different sensors and with different resolutions, and the results demonstrate the potential of the proposed TSSTO method for removing cloud and cloud shadow from both qualitative and quantitative viewpoints.
Remote Cross-Calibration of Wave Buoys Based on Significant Wave Height Observations of Altimeters in the Northern Hemisphere
Authors: Wang Jiuke , Aouf Lotfi , Wang Xianqiao , Li Benxia , Wang Juanjuan
Published: October 2020

Consistency between national wave buoy networks is extremely important for wave climate studies and verification of global operational wave forecasting systems; however, it is insufficiently investigated. The validation of altimeter significant wave heights (SWHs) with the wave buoy networks of China, Europe and the National Data Buoy Center (NDBC) show significant divergence in assessments. This reveals a negative bias and larger root mean square error and scatter index from the Chinese buoy network than from the European and NDBC buoy networks. A remote cross-calibration method is presented using the collocations between altimeters and buoys to match the buoy observations from different networks. The Chinese buoys are found to yield a negative bias of −0.127 m compared to European/NDBC buoy networks. The cross-calibration equation is achieved by regression of the SWHs between the Chinese and European/NDBC buoy networks. The use of this remote cross-calibration significantly reduces the inconsistency between the Chinese and European/NDBC buoys in the validation of SWH from altimeter HY2B.
Changing Patterns of Lakes on The Southern Tibetan Plateau Based on Multi-Source Satellite Data
Authors: Sun Fangdi , Ma Ronghua , He Bin , Zhao Xiaoli , Zeng Yuchao , Zhang Siyi , Tang Shilin
Published: October 2020

More than 1100 lakes covering an area greater than 4500 km2 are located on the Tibetan Plateau, and these lakes are important regulators of several large and famous rivers in Asia. The determination of hydrological changes that have occurred in these lakes can reflect climate change and supply scientific data to plateau environmental research. Data from high frequency (moderate-resolution imaging spectro-radiometer) MODIS images, altimetry, and the Hydroweb database collected during 2000–2015 were integrated in this study to delineate the detailed hydrological changes of 15 lakes in three basins—Inner Basin, Indus Basin, and Brahmaputra Basin—on the southern Tibetan Plateau. Seven of the 10 lakes in the Inner Basin presented increasing trends with various intensities, and the increasing rates in the area of four lakes (Nam Co, Selin Co, Zhari-namco, and Ngangze) were 1.62, 28.81, 2.27, and 3.70 km2/yr, respectively. The yearly increases in volume of the four lakes were 3.6, 9.44, 6, and 2.36 km3, respectively. A water balance equation was established for the four lakes based on lake volume changes to illustrate the contributions of precipitation, ground runoff, evaporation, and other factors. The results revealed that surface runoff was the major contributor to expansion, and lake surface evaporation was almost 2.76–3.86 times that of lake surface precipitation. The two lakes in Indus Basin, Rakshastal and Mapam Yumco, presented a slight retreat. As a representative of Brahmaputra Basin, Yamzho Yumco underwent a retreat of –3.49 km2/yr in area, –0.39 m/yr in level, and –0.19 km3/yr in volume. Decreasing precipitation, increasing evaporation, and the operation of a hydrological project were the main causes of its constant retreat.
Gait Characteristics Harvested during a Smartphone-Based Self-Administered 2-Minute Walk Test in People with Multiple Sclerosis: Test-Retest Reliability and Minimum Detectable Change
Authors: Bourke Alan K. , Scotland Alf , Lipsmeier Florian , Gossens Christian , Lindemann Michael
Published: October 2020

The measurement of gait characteristics during a self-administered 2-minute walk test (2MWT), in persons with multiple sclerosis (PwMS), using a single body-worn device, has the potential to provide high-density longitudinal information on disease progression, beyond what is currently measured in the clinician-administered 2MWT. The purpose of this study is to determine the test-retest reliability, standard error of measurement (SEM) and minimum detectable change (MDC) of features calculated on gait characteristics, harvested during a self-administered 2MWT in a home environment, in 51 PwMS and 11 healthy control (HC) subjects over 24 weeks, using a single waist-worn inertial sensor-based smartphone. Excellent, or good to excellent test-retest reliability were observed in 58 of the 92 temporal, spatial and spatiotemporal gait features in PwMS. However, these were less reliable for HCs. Low SEM% and MDC% values were observed for most of the distribution measures for all gait characteristics for PwMS and HCs. This study demonstrates the inter-session test-retest reliability and provides an indication of clinically important change estimates, for interpreting the outcomes of gait characteristics measured using a body-worn smartphone, during a self-administered 2MWT. This system thus provides a reliable measure of gait characteristics in PwMS, supporting its application for the longitudinal assessment of gait deficits in this population.
A Quartz Crystal Microbalance, Which Tracks Four Overtones in Parallel with a Time Resolution of 10 Milliseconds: Application to Inkjet Printing
Authors: Leppin Christian , Hampel Sven , Meyer Frederick Sebastian , Langhoff Arne , Fittschen Ursula Elisabeth Adriane , Johannsmann Diethelm
Published: October 2020

A quartz crystal microbalance (QCM) is described, which simultaneously determines resonance frequency and bandwidth on four different overtones. The time resolution is 10 milliseconds. This fast, multi-overtone QCM is based on multi-frequency lockin amplification. Synchronous interrogation of overtones is needed, when the sample changes quickly and when information on the sample is to be extracted from the comparison between overtones. The application example is thermal inkjet-printing. At impact, the resonance frequencies change over a time shorter than 10 milliseconds. There is a further increase in the contact area, evidenced by an increasing common prefactor to the shifts in frequency, Δf, and half-bandwidth, ΔΓ. The ratio ΔΓ/(−Δf), which quantifies the energy dissipated per time and unit area, decreases with time. Often, there is a fast initial decrease, lasting for about 100 milliseconds, followed by a slower decrease, persisting over the entire drying time (a few seconds). Fitting the overtone dependence of Δf(n) and ΔΓ(n) with power laws, one finds power-law exponents of about 1/2, characteristic of semi-infinite Newtonian liquids. The power-law exponents corresponding to Δf(n) slightly increase with time. The decrease of ΔΓ/(−Δf) and the increase of the exponents are explained by evaporation and formation of a solid film at the resonator surface.
Toward a Regulatory Qualification of Real-World Mobility Performance Biomarkers in Parkinson’s Patients Using Digital Mobility Outcomes
Authors: Viceconti Marco , Hernandez Penna Sabina , Dartee Wilhelmus , Mazzà Claudia , Caulfield Brian , Becker Clemens , Maetzler Walter , Garcia-Aymerich Judith , Davico Giorgio , Rochester Lynn
Published: October 2020

Wearable inertial sensors can be used to monitor mobility in real-world settings over extended periods. Although these technologies are widely used in human movement research, they have not yet been qualified by drug regulatory agencies for their use in regulatory drug trials. This is because the first generation of these sensors was unreliable when used on slow-walking subjects. However, intense research in this area is now offering a new generation of algorithms to quantify Digital Mobility Outcomes so accurate they may be considered as biomarkers in regulatory drug trials. This perspective paper summarises the work in the Mobilise-D consortium around the regulatory qualification of the use of wearable sensors to quantify real-world mobility performance in patients affected by Parkinson’s Disease. The paper describes the qualification strategy and both the technical and clinical validation plans, which have recently received highly supportive qualification advice from the European Medicines Agency. The scope is to provide detailed guidance for the preparation of similar qualification submissions to broaden the use of real-world mobility assessment in regulatory drug trials.
Biological Activity of Cannabis sativa L. Extracts Critically Depends on Solvent Polarity and Decarboxylation
Authors: Moreno-Sanz Guillermo , Ferreiro Vera Carlos , Sánchez-Carnerero Carolina , Nadal Roura Xavier , Sánchez de Medina Baena Verónica
Published: October 2020

Minor cannabinoid and non-cannabinoid molecules have been proposed to significantly contribute to the pharmacological profile of cannabis extracts. Phytoplant Research has developed highly productive cannabis cultivars with defined chemotypes, as well as proprietary methods for the extraction and purification of cannabinoids. Here, we investigate the effect of solvent selection and decarboxylation on the composition and pharmacological activity of cannabis extracts. A library of forty cannabis extracts was generated from ten different cannabis cultivars registered by Phytoplant Research at the EU Community Plant Variety Office. Plant material was extracted using two different solvents, ethanol and hexane, and crude extracts were subsequently decarboxylated or not. Cannabinoid content in the resulting extracts was quantified, and biological activity was screened in vitro at three molecular targets involved in hypoxia and inflammation (NF-κB, HIF-1α and STAT3). Changes in transcriptional activation were strongly associated to solvent selection and decarboxylation. Two decarboxylated extracts prepared with hexane were the most potent at inhibiting NF-κB transcription, while HIF-1α activation was preferentially inhibited by ethanolic extracts, and decarboxylated extracts were generally more potent at inhibiting STAT3 induction. Our results indicate that solvent selection and proper decarboxylation represent key aspects of the standardized production of cannabis extracts with reproducible pharmacological activity.
Positive Externalities from Professional Football Clubs in the Metropolitan Rhine-Ruhr, Germany: Trickle-Down Effects Associated with Promotion and Relegation
Authors: Pyun Hyunwoong , Kim Jeeyoon , Schlesinger Torsten , Matto Luca
Published: October 2020

Hosting sport events is costly, but the positive impact of hosting sport events has not been studied well. We consider the promotion of physical activity, known as the trickle-down effect, to be a new dimension of this kind of impact. Using exogenous variations in promotion and relegation in the Bundesliga 1, we test the effect of the presence of a Bundesliga 1 club on local non-profit football club membership. Using German city-level annual non-profit sport club membership data from the metropolitan Rhine-Ruhr, we group cities with experience of either promotion or relegation as treatment cities and other cities as the comparison group. Difference-in-difference analyses show that promotion (using a strict definition of promotion) of local professional football clubs increases non-profit football club membership by 14% while relegation does not affect membership. The presence of Bundesliga 1 clubs in a city increases non-profit football club membership by 11%. Falsification tests support the idea that the impact of promotion on membership results in a net increase in membership.
The Socio-Economic Impact of Migration on the Labor Market in the Romanian Danube Region
Authors: Chiripuci Bogdan-Cristian , Constantin Marius , Popescu Maria-Floriana , Scrieciu Albert
Published: October 2020

The dynamics of the labor market have been significantly influenced and impacted in recent decades by the scale of globalization, not only from a socio-economic standpoint, but also from the perspective of generating the premises of destroying boundaries. Taking this into consideration, our research is aimed at highlighting the socio-economic impact of migration on the labor market in the Romanian Danube Region in order to create a framework which can be used when elaborating a solid action plan meant to increase the socio-economic attractivity in the analyzed region. This research was carried out by resorting to the multicriterial analysis, aimed at quantifying the state of development of the analyzed counties from the perspective of clearly defined socio-economic indicators. Additionally, the linear regression research method was applied in order to ensure a more in-depth analysis of the relationship between local employment and the departure from domicile. The main finding was that Mehedinţi County has greater potential for socio-economic development than the neighboring county, even though the population is not encouraged to remain in the rural areas, one of the reasons being the lack of attractiveness of the local labor market. The designed econometric model confirms (66.17%) this result in the case of the localities part of Mehedinţi County.
Identification of Key Carbon Emission Sectors and Analysis of Emission Effects in China
Authors: Yuan Yongke , Wang Yixing , Chi Yuanying , Jin Feng
Published: October 2020

Analysis of sectors’ emission effects is crucial for identifying key emission sectors and reducing carbon. Current literature for calculating sectors’ emission effects in China ignore intermediate demand. This might introduce inaccuracy into the analyzed results. To solve this gap, this paper used an alternative input–output method to analyze sectors’ emission effects in China. Firstly, it identifies the key emission sectors and their emission effect characteristics from 2005 to 2017. Then, the reasons for the changes in these sectors’ emission effects are analyzed. Lastly, emission effects were further decomposed so that the driving relationships of emissions among these sectors can be sorted out. The results show that the overall key emission sectors were metal smelting and processing and nonmetal mineral products. The backward-emission-dominant sectors were construction, chemical products, other services (such as finance, health and education), metal products, and so on. The forward-emission-dominant sectors were production and supply of electricity and heat, transportation, storage, postal, and telecommunications services. In 2017, transportation, storage, postal, and telecommunications services’ own final demand emissions and forward emissions accounted for 41.7% and 58.3%, respectively, of this sector’s direct emissions. Moreover, from 2005 to 2017, the main sector emission paths affecting the growth of China’s emissions shifted from manufacturing and construction industries to service industries. Accordingly, strategies for emission reduction, such as substituting pollution inputs, were proposed and analyzed. The research provides an important reference for the Chinese government to adopt appropriate measures to reduce carbon.
Mechanisms of Grazing Management in Heterogeneous Swards
Authors: Pontes-Prates Arthur , de Faccio Carvalho Paulo César , Laca Emilio Andrés
Published: October 2020

We explored the effects of heterogeneity of sward height on the functioning of grazing systems through a spatially implicit mechanistic model of grazing and sward growth. The model uses a population dynamic approach where a sward is spatially structured by height, which changes as a function of defoliation, trampling, and growth. The grazing component incorporates mechanisms of bite formation, intake, and digestion rates, but excludes sward quality effects. Sward height selection is determined by maximization of the instantaneous intake rate of forage dry mass. For any given average sward height, intake rate increased with increasing spatial heterogeneity. Spatio-temporal distribution of animal density over paddocks did not markedly affect animal performance but it modified the balance of vegetation heterogeneity within and between paddocks. Herbage allowance was a weak predictor of animal performance because the same value can result from multiples combinations of herbage mass per unit area, number of animals, animal liveweight, and paddock area, which are the proximate determinants of intake rate. Our results differ from models that assume homogeneity and provide strong evidence of how heterogeneity influences the dynamic of grazing systems. Thus, we argue that grazing management and research need to incorporate the concept of heterogeneity into the design of future grazing systems.
Discovering Spatio-Temporal Clusters of Road Collisions Using the Method of Fast Bayesian Model-Based Cluster Detection
Authors: Sun Yeran , Wang Yu , Yuan Ke , Chan Ting On , Huang Ying
Published: October 2020

Public availability of geo-coded or geo-referenced road collisions (crashes) makes it possible to perform geovisualisation and spatio-temporal analysis of road collisions across a city. This study aims to detect spatio-temporal clusters of road collisions across Greater London between 2010 and 2014. We implemented a fast Bayesian model-based cluster detection method with no covariates and after adjusting for potential covariates respectively. As empirical evidence on the association of street connectivity measures and the occurrence of road collisions had been found, we selected street connectivity measures as the potential covariates in our cluster detection. Results of the most significant cluster and the second most significant cluster during five consecutive years are located around the central areas. Moreover, after adjusting the covariates, the most significant cluster moves from the central areas of London to its peripheral areas, while the second most significant cluster remains unchanged. Additionally, one potential covariate used in this study, length-based road density, exhibits a positive association with the number of road collisions; meanwhile count-based intersection density displays a negative association. Although the covariates (i.e., road density and intersection density) exhibit potential impact on the clusters of road collisions, they are unlikely to contribute to the majority of clusters. Furthermore, the method of fast Bayesian model-based cluster detection is developed to discover spatio-temporal clusters of serious injury collisions. Most of the areas at risk of serious injury collisions overlay those at risk of road collisions. Although not being identified as areas at risk of road collisions, some districts, e.g., City of London, are regarded as areas at risk of serious injury collisions.
HDPE Geomembranes for Environmental Protection: Two Case Studies
Authors: Lavoie Fernando Luiz , Valentin Clever Aparecido , Kobelnik Marcelo , Lins da Silva Jefferson , Lopes Maria de Lurdes
Published: October 2020

High-density polyethylene (HDPE) geomembranes have been used for different applications in engineering including sanitation, such as landfills and waste liquid ponds. For these applications, the material can be exposed to aging mechanisms as thermal and chemical degradation, even to UV radiation and biological contact, which can degrade the geomembrane and decrease the material’s durability. This paper aims to present an experimental evaluation of two exhumed HDPE geomembranes, the first was used for 2.75 years in a sewage treatment aeration pond (LTE sample) and another was used for 5.17 years in a municipal landfill leachate pond (LCH sample). Physical and thermal analyses were used such as thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC) and dynamic mechanic analysis (DMA). The thermogravimetric analyses showed significant changes in the LCH sample’s thermal decomposition probably caused by the interaction reactions between the polymer and the leachate. For the DSC analyses, the behavior seen in the LTE sample was not observed in the LCH sample. In the DMA analyses, the behavior of the LTE sample storage module shows which LCH sample is less brittle. The LTE sample presented low stress cracking resistance and low tensile elongation at break, following the DMA results.
Teenagers’ Awareness about Local Vertebrates and Their Functions: Strengthening Community Environmental Education in a Mexican Shade-Coffee Region to Foster Animal Conservation
Authors: Andresen Ellen , López-del-Toro Paulina , Franquesa-Soler Montserrat , Mora Francisco , Barraza Laura
Published: October 2020

Peoples’ understanding and appreciation of wildlife are crucial for its conservation. Nevertheless, environmental education in many tropical countries is seldom incorporated into public-school curricula and wildlife topics are often underrepresented. In this research we aimed to (1) assess the effects of an environmental education intervention focused on improving students’ awareness about wild vertebrates and their ecological functions and (2) to evaluate whether previous exposure to general environmental education could improve the effects of the intervention. We worked in four schools in a high-biodiversity shade-coffee-producing region in Mexico; two of the schools had received general environmental education as part of a Community Program, while the other two had not. In all schools we conducted a targeted intervention providing information about wild vertebrates and their ecological functions. Through questionnaires, we assessed students’ awareness before and after the intervention. We found that students’ awareness about wildlife was improved by our intervention, and that this effect was stronger in students that had attended the Community Program. Our results contribute to Sustainable Development Goals 11 and 15 by showing that targeted education interventions can help achieve specific conservation goals, and that previous community-based environmental education can condition peoples’ awareness, improving the assimilation and/or understanding of new concepts.
Algebraic DVR Approaches Applied to Describe the Stark Effect
Authors: Bermúdez-Montaña Marisol , Rodríguez-Arcos Marisol , Lemus Renato , Arias José M. , Gómez-Camacho Joaquín , Orgaz Emilio
Published: October 2020

Two algebraic approaches based on a discrete variable representation are introduced and applied to describe the Stark effect in the non-relativistic Hydrogen atom. One approach consists of considering an algebraic representation of a cutoff 3D harmonic oscillator where the matrix representation of the operators r2 and p2 are diagonalized to define useful bases to obtain the matrix representation of the Hamiltonian in a simple form in terms of diagonal matrices. The second approach is based on the U(4) dynamical algebra which consists of the addition of a scalar boson to the 3D harmonic oscillator space keeping constant the total number of bosons. This allows the kets associated with the different subgroup chains to be linked to energy, coordinate and momentum representations, whose involved branching rules define the discrete variable representation. Both methods, although originating from the harmonic oscillator basis, provide different convergence tests due to the fact that the associated discrete bases turn out to be different. These approaches provide powerful tools to obtain the matrix representation of 3D general Hamiltonians in a simple form. In particular, the Hydrogen atom interacting with a static electric field is described. To accomplish this task, the diagonalization of the exact matrix representation of the Hamiltonian is carried out. Particular attention is paid to the subspaces associated with the quantum numbers n=2,3 with m=0.
A Comparative Usability Study of Bare Hand Three-Dimensional Object Selection Techniques in Virtual Environment
Authors: Zhou Xiaozhou , Qin Hao , Xiao Weiye , Jia Lesong , Xue Chengqi
Published: October 2020

Object selection is the basis of natural user–computer interaction (NUI) in a virtual environment (VE). Among the three-dimensional object selection techniques employed in virtual reality (VR), bare hand-based finger clicking interaction and ray-casting are two convenient approaches with a high level of acceptance. This study involved 14 participants, constructed a virtual laboratory environment in VR, and compared the above two finger-based interaction techniques in terms of aspects of the task performance, including the success rate, total reaction time, operational deviation, and accuracy, at different spatial positions. The results indicated that the applicable distance range of finger clicking interaction and finger ray-casting was 0.2 to 1.4 m and over 0.4 m, respectively. Within the shared applicable distance, the finger clicking interaction achieved a shorter total reaction time and higher clicking accuracy. The performance of finger clicking interaction varied remarkably at the center and edge of the horizontal field of view, while no significant difference was found among ray-casting at various horizontal azimuths. The current findings could be directly applied to the application of bare-hand interaction in VR environments.
Nonlinear Dynamic Behavior of Porous and Imperfect Bernoulli-Euler Functionally Graded Nanobeams Resting on Winkler Elastic Foundation
Authors: Penna Rosa , Feo Luciano
Published: October 2020

Nonlinear free vibrations of functionally graded porous Bernoulli–Euler nano-beams resting on an elastic foundation through a stress-driven nonlocal elasticity model are studied taking into account von Kármán type nonlinearity and initial geometric imperfection. By using the Galerkin method, the governing equations are reduced to a nonlinear ordinary differential equation. The closed form analytical solution of the nonlinear natural flexural frequency is then established using the Hamiltonian approach to nonlinear oscillators. Several comparisons with existing models in the literature are performed to validate the accuracy and reliability of the proposed approach. Finally, a numerical investigation is developed in order to analyze the effects of the gradient index coefficient, porosity volume fraction, initial geometric imperfection, and the Winkler elastic foundation coefficient, on the nonlinear flexural vibrations of metal–ceramic FG porous Bernoulli–Euler nano-beams.
Gravity with Higher Derivatives in D-Dimensions
Authors: Rubin Sergey G. , Popov Arkadiy , Petriakova Polina M.
Published: October 2020

The aim of this review is to discuss the ways to obtain results based on gravity with higher derivatives in D-dimensional world. We considered the following ways: (1) reduction to scalar tensor gravity, (2) direct solution of the equations of motion, (3) derivation of approximate equations in the presence of a small parameter in the system, and (4) the method of test functions. Some applications are presented to illustrate each method. The unification of two necessary elements of a future theory is also kept in mind—the extra dimensions and the extended form of the gravity.
Gravitational Radiation as the Bremsstrahlung of Superheavy Particles in the Early Universe
Authors: Grib Andrey A. , Pavlov Yuri V.
Published: October 2020

The number of superheavy particles with the mass of the Grand Unification scale with trans-Planckian energy created at the epoch of superheavy particle creation from the vacuum by the gravitation of the expanding Universe is calculated. In later collisions of these particles, gravitational radiation is radiated playing the role of bremsstrahlung for gravity. The effective background radiation of the Universe is evaluated.
Synthesis, Structure, and Function of Human Adenovirus Small Non-Coding RNAs
Authors: Punga Tanel , Darweesh Mahmoud , Akusjärvi Göran
Published: October 2020

Human adenoviruses (HAdVs) are common pathogens causing a variety of respiratory, ocular and gastrointestinal diseases. To accomplish their efficient replication, HAdVs take an advantage of viral small non-coding RNAs (sncRNAs), which have multiple roles during the virus lifecycle. Three of the best-characterized HAdV sncRNAs; VA RNA, mivaRNA and MLP-TSS-sRNA will be discussed in the present review. Even though VA RNA has been extensively characterized during the last 60 years, this multifunctional molecule continues to surprise us as more of its structural secrets unfold. Likely, the recent developments on mivaRNA and MLP-TSS-sRNA synthesis and function highlight the importance of these sncRNA in virus replication. Collectively, we will summarize the old and new knowledge about these three viral sncRNAs with focus on their synthesis, structure and functions.
A Nationwide Study about the Dispersal Patterns of the Predominant HIV-1 Subtypes A1 and B in Greece: Inference of the Molecular Transmission Clusters
Authors: Kostaki Evangelia Georgia , Gova Maria , Adamis Georgios , Xylomenos Georgios , Chini Maria , Mangafas Nikos , Lazanas Marios , Metallidis Simeon , Tsachouridou Olga , Papastamopoulos Vasileios , Chatzidimitriou Dimitrios , Kakalou Eleni , Antoniadou Anastasia , Papadopoulos Antonios , Psichogiou Mina , Basoulis Dimitrios , Pilalas Dimitrios , Papageorgiou Ifigeneia , Paraskeva Dimitra , Chrysos Georgios , Paparizos Vasileios , Kourkounti Sofia , Sambatakou Helen , Bolanos Vasileios , Sipsas Nikolaos V. , Lada Malvina , Barbounakis Emmanouil , Kantzilaki Evrikleia , Panagopoulos Periklis , Petrakis Vasilis , Drimis Stelios , Gogos Charalambos , Hatzakis Angelos , Beloukas Apostolos , Skoura Lemonia , Paraskevis Dimitrios
Published: October 2020

Our aim was to investigate the dispersal patterns and parameters associated with local molecular transmission clusters (MTCs) of subtypes A1 and B in Greece (predominant HIV-1 subtypes). The analysis focused on 1751 (28.4%) and 2575 (41.8%) sequences of subtype A1 and B, respectively. Identification of MTCs was based on phylogenetic analysis. The analyses identified 38 MTCs including 2–1518 subtype A1 sequences and 168 MTCs in the range of 2–218 subtype B sequences. The proportion of sequences within MTCs was 93.8% (1642/1751) and 77.0% (1982/2575) for subtype A1 and B, respectively. Transmissions within MTCs for subtype A1 were associated with risk group (Men having Sex with Men vs. heterosexuals, OR = 5.34, p < 0.001) and Greek origin (Greek vs. non-Greek origin, OR = 6.05, p < 0.001) and for subtype B, they were associated with Greek origin (Greek vs. non-Greek origin, OR = 1.57, p = 0.019), younger age (OR = 0.96, p < 0.001), and more recent sampling (time period: 2011–2015 vs. 1999–2005, OR = 3.83, p < 0.001). Our findings about the patterns of across and within country dispersal as well as the parameters associated with transmission within MTCs provide a framework for the application of the study of molecular clusters for HIV prevention.
A Decade in Review: A Systematic Review of Universal Influenza Vaccines in Clinical Trials during the 2010 Decade
Authors: Corder Brigette N. , Bullard Brianna L. , Poland Gregory A. , Weaver Eric A.
Published: October 2020

On average, there are 3–5 million severe cases of influenza virus infections globally each year. Seasonal influenza vaccines provide limited protection against divergent influenza strains. Therefore, the development of a universal influenza vaccine is a top priority for the NIH. Here, we report a comprehensive summary of all universal influenza vaccines that were tested in clinical trials during the 2010–2019 decade. Of the 1597 studies found, 69 eligible clinical trials, which investigated 27 vaccines, were included in this review. Information from each trial was compiled for vaccine target, vaccine platform, adjuvant inclusion, clinical trial phase, and results. As we look forward, there are currently three vaccines in phase III clinical trials which could provide significant improvement over seasonal influenza vaccines. This systematic review of universal influenza vaccine clinical trials during the 2010–2019 decade provides an update on the progress towards an improved influenza vaccine.
A Systematic Evaluation of High-Throughput Sequencing Approaches to Identify Low-Frequency Single Nucleotide Variants in Viral Populations
Authors: King David J. , Freimanis Graham , Lasecka-Dykes Lidia , Asfor Amin , Ribeca Paolo , Waters Ryan , King Donald P. , Laing Emma
Published: October 2020

High-throughput sequencing such as those provided by Illumina are an efficient way to understand sequence variation within viral populations. However, challenges exist in distinguishing process-introduced error from biological variance, which significantly impacts our ability to identify sub-consensus single-nucleotide variants (SNVs). Here we have taken a systematic approach to evaluate laboratory and bioinformatic pipelines to accurately identify low-frequency SNVs in viral populations. Artificial DNA and RNA “populations” were created by introducing known SNVs at predetermined frequencies into template nucleic acid before being sequenced on an Illumina MiSeq platform. These were used to assess the effects of abundance and starting input material type, technical replicates, read length and quality, short-read aligner, and percentage frequency thresholds on the ability to accurately call variants. Analyses revealed that the abundance and type of input nucleic acid had the greatest impact on the accuracy of SNV calling as measured by a micro-averaged Matthews correlation coefficient score, with DNA and high RNA inputs (107 copies) allowing for variants to be called at a 0.2% frequency. Reduced input RNA (105 copies) required more technical replicates to maintain accuracy, while low RNA inputs (103 copies) suffered from consensus-level errors. Base errors identified at specific motifs identified in all technical replicates were also identified which can be excluded to further increase SNV calling accuracy. These findings indicate that samples with low RNA inputs should be excluded for SNV calling and reinforce the importance of optimising the technical and bioinformatics steps in pipelines that are used to accurately identify sequence variants.
Phosphoinositide 3′-Kinase γ Facilitates Polyomavirus Infection
Authors: Clark Paul , Gee Gretchen V. , Albright Brandon S. , Assetta Benedetta , Han Ying , Atwood Walter J. , DiMaio Daniel
Published: October 2020

Polyomaviruses are small, non-enveloped DNA tumor viruses that cause serious disease in immunosuppressed people, including progressive multifocal leukoencephalopathy (PML) in patients infected with JC polyomavirus, but the molecular events mediating polyomavirus entry are poorly understood. Through genetic knockdown approaches, we identified phosphoinositide 3′-kinase γ (PI3Kγ) and its regulatory subunit PIK3R5 as cellular proteins that facilitate infection of human SVG-A glial cells by JCPyV. PI3Kα appears less important for polyomavirus infection than PI3Kγ. CRISPR/Cas9-mediated knockout of PIK3R5 or PI3Kγ inhibited infection by authentic JCPyV and by JC pseudovirus. PI3Kγ knockout also inhibited infection by BK and Merkel Cell pseudoviruses, other pathogenic human polyomaviruses, and SV40, an important model polyomavirus. Reintroduction of the wild-type PI3Kγ gene into the PI3Kγ knock-out SVG-A cells rescued the JCPyV infection defect. Disruption of the PI3Kγ pathway did not block binding of JCPyV to cells or virus internalization, implying that PI3Kγ facilitates some intracellular step(s) of infection. These results imply that agents that inhibit PI3Kγ signaling may have a role in managing polyomavirus infections.
Poxviral Targeting of Interferon Regulatory Factor Activation
Authors: Lawler Clara , Brady Gareth
Published: October 2020

As viruses have a capacity to rapidly evolve and continually alter the coding of their protein repertoires, host cells have evolved pathways to sense viruses through the one invariable feature common to all these pathogens—their nucleic acids. These genomic and transcriptional pathogen-associated molecular patterns (PAMPs) trigger the activation of germline-encoded anti-viral pattern recognition receptors (PRRs) that can distinguish viral nucleic acids from host forms by their localization and subtle differences in their chemistry. A wide range of transmembrane and cytosolic PRRs continually probe the intracellular environment for these viral PAMPs, activating pathways leading to the activation of anti-viral gene expression. The activation of Nuclear Factor Kappa B (NFκB) and Interferon (IFN) Regulatory Factor (IRF) family transcription factors are of central importance in driving pro-inflammatory and type-I interferon (TI-IFN) gene expression required to effectively restrict spread and trigger adaptive responses leading to clearance. Poxviruses evolve complex arrays of inhibitors which target these pathways at a variety of levels. This review will focus on how poxviruses target and inhibit PRR pathways leading to the activation of IRF family transcription factors.
Immunogenicity of Alternative Dosing Schedules for HPV Vaccines among Adolescent Girls and Young Women: A Systematic Review and Meta-Analysis
Authors: Secor Andrew M. , Driver Matthew , Kharono Brenda , Hergott Dianna , Liu Gui , Barnabas Ruanne V. , Dull Peter , Hawes Stephen E. , Drain Paul K.
Published: October 2020

Alternative dosing schedules for licensed human papilloma virus (HPV) vaccines, particularly single dose and extended intervals between doses (>12 months), are being considered to address vaccine shortages and improve operational flexibility. We searched PUBMED/MEDLINE for publications reporting immunogenicity data following administration of one of the licensed HPV vaccines (2vHPV, 4vHPV, and 9vHPV) to females aged 9–26 years. We conducted non-inferiority analyses comparing alternative to standard schedules using mixed effects meta-regression controlling for baseline HPV status and disaggregated by vaccine, subtype, time point, and age group (9–14 and 15–26 years). Non-inferiority was defined as the lower bound of the 95% confidence interval (CI) for the geometric mean titer (GMT) ratio being greater than 0.5. Our search returned 2464 studies, of which 23 were included in data analyses. When evaluated against standard schedules, although robust immunogenicity was demonstrated across all multi-dose groups, non-inferiority of extended interval dosing was mixed across vaccines, subtypes, and time points. Single dose did not meet the criteria for non-inferiority in any comparisons. Sparse data limited the number of possible comparisons, and further research is warranted.
A New Tool for Assessing Environmental Impacts of Altering Short-Term Flow and Water Level Regimes
Authors: Bejarano María Dolores , García-Palacios Jaime H. , Sordo-Ward Alvaro , Garrote Luis , Nilsson Christer
Published: October 2020

The computational tool InSTHAn (indicators of short-term hydrological alteration) was developed to summarize data on subdaily stream flows or water levels into manageable, comprehensive and ecologically meaningful metrics, and to qualify and quantify their deviation from unaltered states. The pronunciation of the acronym refers to the recording interval of input data (i.e., instant). We compared InSTHAn with the tool COSH-Tool in a characterization of the subdaily flow variability of the Colorado River downstream from the Glen Canyon dam, and in an evaluation of the effects of the dam on this variability. Both tools captured the hydropeaking caused by a dam operation, but only InSTHAn quantified the alteration of key flow attributes, highlighting significant increases in the range of within-day flow variations and in their rates of change. This information is vital to evaluate the potential ecological consequences of the hydrological alteration, and whether they may be irreversible, making InSTHAn a key tool for river flow management.