bluuebunny/crossref_metadata_2025 huggingface dataset:
Lagrangian Regularized Twin Extreme Learning Machine for Supervised and Semi-Supervised Classification
Authors: Ma Jun , Yu Guolin
Published: June 2022

Twin extreme learning machine (TELM) is a phenomenon of symmetry that improves the performance of the traditional extreme learning machine classification algorithm (ELM). Although TELM has been widely researched and applied in the field of machine learning, the need to solve two quadratic programming problems (QPPs) for TELM has greatly limited its development. In this paper, we propose a novel TELM framework called Lagrangian regularized twin extreme learning machine (LRTELM). One significant advantage of our LRTELM over TELM is that the structural risk minimization principle is implemented by introducing the regularization term. Meanwhile, we consider the square of the l2-norm of the vector of slack variables instead of the usual l1-norm in order to make the objective functions strongly convex. Furthermore, a simple and fast iterative algorithm is designed for solving LRTELM, which only needs to iteratively solve a pair of linear equations in order to avoid solving two QPPs. Last, we extend LRTELM to semi-supervised learning by introducing manifold regularization to improve the performance of LRTELM when insufficient labeled samples are available, as well as to obtain a Lagrangian semi-supervised regularized twin extreme learning machine (Lap-LRTELM). Experimental results on most datasets show that the proposed LRTELM and Lap-LRTELM are competitive in terms of accuracy and efficiency compared to the state-of-the-art algorithms.
Influence of Elastic–Plastic Deformation on the Structure and Magnetic Characteristics of 13Cr-V Alloyed Steel Pipe
Authors: Putilova Evgeniia , Kryucheva Kristina
Published: June 2022

The principle of symmetry is one of the general methodological principles of science. The effects of any external influences, such as deformation, stresses, temperature, etc., could lead to the anisotropy (asymmetry) of properties in constructional materials. During operation, metal structures and machine parts are exposed to time-varying external mechanical loads, which can cause changes in the metal structure, the initiation of cracks, and, as a result, the destruction of the product. The application of nondestructive testing methods prevents changes in the stress–strain state and, consequently, the destruction of the object. This article contains the results of studying the effects of elastic–plastic deformation by uniaxial tension and torsion on the change in the structure and magnetic parameters of low-alloy 13Cr-V pipe steel. Modern methods of metallography and magnetic nondestructive testing methods were used as part of this study. The results of the EBSD analysis showed that deformation during torsion, in contrast to uniaxial tension, is unevenly distributed over the sample cross section. In the cross section of the sample, the most severely deformed grains with a change in their geometry are observed near the surface; in the center, there is no change in geometry. During tension, the deformation over the cross section of the sample is uniformly distributed. Correlations between the applied normal and tangential stresses and magnetic characteristics of the 13Cr-V structural steel were determined. Informative parameters that could be used for the development of nondestructive testing methodologies for solving concrete tasks were determined. Different methods of deformation lead to diverse structural changes in grain structure.
Nonnegative Estimation of Variance Components for a Nested Three-Way Random Model
Authors: Choi Jaesung
Published: June 2022

A nonnegative variance estimation procedure is suggested for an unbalanced data where two factors are nested in another. Since the involved factors are all random, the approach is based on a nested three-way random model. The proposed method for the estimation of variance components is compared with Henderson’s Method I and III in view of the same estimation procedure based on the method of moments. Although both the Henderson’s Method I and III are known to be useful for the estimation of variance components for balanced or unbalanced data, they often yield negative values as variance estimates whereas the estimates by the suggested method are never be negative. Hence, it points out what makes this happen and discusses how to fix the problem. The proposed method shows how to define sums of squares and the orthogonal coefficient matrices that are necessary for the evaluation of expectations. All the matrices of the quadratic forms for computing sums of squares are symmetric and idempotent. It also reveals the individual coefficient of each variance component does not change from equation to equation.
Special Issue Editorial “Symmetry in Structural Health Monitoring”
Authors: Yang Yang
Published: June 2022

Structural health monitoring refers to the strategy and process of the damage diagnosis and characterization of civil engineering structures, also showing the importance of structural health monitoring where symmetry is widely used, such as the building collapse accident in Changsha city, Hunan Province, in May 2022 [...]
An Efficient Method for Solving Second-Order Fuzzy Order Fuzzy Initial Value Problems
Authors: Dallashi Qamar , Syam Muhammed I.
Published: June 2022

In this paper, we present an accurate numerical approach based on the reproducing kernel method (RKM) for solving second-order fuzzy initial value problems (FIVP) with symmetry coefficients such as symmetric triangles and symmetric trapezoids. Finding the exact solution of FIVP is not an easy task since the definition will produce a complicated optimization problem. To overcome this difficulty, a numerical method is developed to solve this type of problems. We start by introducing the necessary definitions and theorems about the fuzzy logic. Then, we derived the kernels for two Hilbert spaces. The RKM is derived for the second-order IVP in the Boolean sense, and then we generalize it for the fuzzy sense. Numerical and theoretical results will be given to obtain the accuracy of the developed technique. We solved four linear and non-linear fuzzy IVPs numerically using the proposed method, and we compute the error in each case to show the efficiency of the method. The absolute error was very small in the four examples.
Consumption of Herbal Supplements or Homeopathic Remedies to Prevent COVID-19 and Intention of Vaccination for COVID-19 in Latin America and the Caribbean
Authors: Bendezu-Quispe Guido , Benites-Meza Jerry K. , Urrunaga-Pastor Diego , Herrera-Añazco Percy , Uyen-Cateriano Angela , Rodriguez-Morales Alfonso J. , Toro-Huamanchumo Carlos J. , Hernandez Adrian V. , Benites-Zapata Vicente A.
Published: June 2022

Users of complementary and alternative medicine (CAM) have a lower intention to receive vaccines. Furthermore, Latin America and the Caribbean (LAC) region are among the most affected areas by the COVID-19 pandemics and present a high proportion of CAM users. Therefore, this study evaluates the association between the consumption of herbal supplements or homeopathic remedies to prevent COVID-19 and the intention to vaccinate against COVID-19 in the LAC region. We conducted a secondary data analysis of a Massachusetts Institute of Technology (MIT) survey with Facebook to assess COVID-19 beliefs, behaviours, and norms. Crude and adjusted prevalence ratios (aPR) with their respective 95% confidence intervals (95% CI) were calculated using generalized linear models of the Poisson family with the log link function. The prevalence of the use of products to prevent COVID-19 was the following: consumption of herbal supplements (7.2%), use of homeopathic remedies (4.8%), and consumption of garlic, ginger, and lemon (11.8%). An association was found between using herbal supplements (19.0% vs. 12.8%; aPR = 1.44; 95% CI: 1.30–1.58), the use of homeopathic remedies (20.3% vs. 12.3%; aPR = 1.58; 95% CI: 1.25–1.98), and the consumption of garlic, ginger, and lemon (18.9% vs. 11.9%; aPR = 1.55; 95% CI: 1.50–1.61) and non-intention to vaccinate against COVID-19. In the LAC population, there is an association between using herbal supplements, using homeopathic remedies and consuming garlic, ginger, and lemon to prevent infection by COVID-19 and non-intention to vaccinate against this disease. Therefore, it is necessary to design targeted strategies for groups that consume these products as preventive measures against COVID-19 to increase vaccination coverage and expand the information regarding transmission and prevention strategies for SARS-CoV-2.
Testing Quantum Gravity in the Multi-Messenger Astronomy Era
Authors: Piórkowska-Kurpas Aleksandra , Biesiada Marek
Published: June 2022

Quantum gravity (QG) remains elusive despite almost century-long efforts to combine general relativity and quantum mechanics. All the approaches triggered and powered by purely theoretical considerations eventually failed with a prevailing feeling of a complete lack of guidance from the experimental side. Currently, however, this circumstance is beginning to change considerably. We have entered the era of multi-messenger astronomy. The electromagnetic window to the universe—so far the only one—has been tremendously enlarged in the energy range beyond gamma rays up to ultra-high-energy photons and has been complemented by other messengers: high-energy cosmic rays, cosmic neutrinos, and gravitational waves (GWs). This has created a unique environment in which to observationally constrain various phenomenological QG effects. In this paper, we focus on the LIV phenomenology manifested as energy-dependent time-of-flight delays and strong lensing time delays. We review results regarding time-of-flight delays obtained with GRBs. We also recall the idea of energy-dependent lensing time delays, which allow one to constrain LIV models independently of the intrinsic time delay. Lastly, we show how strongly a gravitationally lensed GW signal would place interesting constraints on the LIV.
Analytic Solution and Noether Symmetries for the Hyperbolic Inflationary Model in the Jordan Frame
Authors: Paliathanasis Andronikos
Published: June 2022

The Noether symmetry analysis is applied for the study of a multifield cosmological model in a spatially flat FLRW background geometry. The gravitational Action Integral consists of two scalar fields, the Brans–Dicke field and a second scalar field minimally coupled to gravity. However, the two scalar fields interact in kinetic terms. This multifield has been found to describe the equivalent of hyperbolic inflation in the Jordan frame. The application of Noether’s theorems constrains the free parameters of the model so that conservation laws exist. We find that the field equations form an integrable dynamical system, and the analytic solution is derived.
Identification of Dobrava-Belgrade Virus in Apodemus flavicollis from North-Eastern Italy during Enhanced Mortality
Authors: Leopardi Stefania , Drzewnioková Petra , Baggieri Melissa , Marchi Antonella , Bucci Paola , Bregoli Marco , De Benedictis Paola , Gobbo Federica , Bellinati Laura , Citterio Carlo , Monne Isabella , Pastori Ambra , Zamperin Gianpiero , Palumbo Elisa , Festa Francesca , Castellan Martina , Zorzan Maira , D’Ugo Emilio , Zucca Paolo , Terregino Calogero , Magurano Fabio
Published: June 2022

Hantaviruses include several zoonotic pathogens that cause different syndromes in humans, with mortality rates ranging from 12 to 40%. Most commonly, humans get infected through the inhalation of aerosols or dust particles contaminated with virus-containing rodent excreta. Hantaviruses are specifically associated with the host species, and human cases depend on the presence and the dynamics of reservoir hosts. In this letter, we report the identification of Dobrava-Belgrade virus (DOBV) in the yellow-necked mouse (Apodemus flavicollis) from Italy. The virus was detected in the mountainous area of the province of Udine, bordering Austria and Slovenia, during an event of enhanced mortality in wild mice and voles. Despite serological evidence in rodents and humans that suggested the circulation of hantaviruses in Italy since 2000, this is the first virological confirmation of the infection. Phylogenetic analyses across the whole genome of the two detected viruses confirmed the host-specificity of DOBV sub-species and showed the highest identity with viruses identified in Slovenia and Croatia from both A. flavicollis and humans, with no signs of reassortment. These findings highlight the need for ecologists, veterinarians and medical doctors to come together in a coordinated approach in full compliance with the One Health concept.
Natural Immunity against HIV-1: Progression of Understanding after Association Studies
Authors: Luo Ma
Published: June 2022

Natural immunity against HIV has been observed in many individuals in the world. Among them, a group of female sex workers enrolled in the Pumwani sex worker cohort remained HIV uninfected for more than 30 years despite high-risk sex work. Many studies have been carried out to understand this natural immunity to HIV in the hope to develop effective vaccines and preventions. This review focuses on two such examples. These studies started from identifying immunogenetic or genetic associations with resistance to HIV acquisition, and followed up with an in-depth investigation to understand the biological relevance of the correlations of protection, and to develop and test novel vaccines and preventions.
Development of a Singleplex Real-Time Reverse Transcriptase PCR Assay for Pan-Dengue Virus Detection and Quantification
Authors: Songjaeng Adisak , Thiemmeca Somchai , Mairiang Dumrong , Punyadee Nuntaya , Kongmanas Kessiri , Hansuealueang Prachya , Tangthawornchaikul Nattaya , Duangchinda Thaneeya , Mongkolsapaya Juthathip , Sriruksa Kanokwan , Limpitikul Wannee , Malasit Prida , Avirutnan Panisadee
Published: June 2022

Dengue virus (DENV) infection is a significant global health problem. There are no specific therapeutics or widely available vaccines. Early diagnosis is critical for patient management. Viral RNA detection by multiplex RT-PCR using multiple pairs of primers/probes allowing the simultaneous detection of all four DENV serotypes is commonly used. However, increasing the number of primers in the RT-PCR reaction reduces the sensitivity of detection due to the increased possibility of primer dimer formation. Here, a one tube, singleplex real-time RT-PCR specific to DENV 3′-UTR was developed for the detection and quantification of pan-DENV with no cross reactivity to other flaviviruses. The sensitivity of DENV detection was as high as 96.9% in clinical specimens collected at the first day of hospitalization. Our assay provided equivalent PCR efficiency and RNA quantification among each DENV serotype. The assay’s performance was comparable with previously established real-time RT-PCR targeting coding sequences. Using both assays on the same specimens, our results indicate the presence of defective virus particles in the circulation of patients infected with all serotypes. Dual regions targeting RT-PCR enhanced the sensitivity of viral genome detection especially during the late acute phase when viremia rapidly decline and an incomplete viral genome was clinically evident.
First Evidence of Past and Present Interactions between Viruses and the Black Soldier Fly, Hermetia illucens
Authors: Pienaar Robert D. , Gilbert Clément , Belliardo Carole , Herrero Salvador , Herniou Elisabeth A.
Published: June 2022

Black soldier flies (BSFs, Hermetia illucens) are becoming a prominent research model encouraged by the insect as food and feed and waste bioconversion industries. Insect mass-rearing facilities are at risk from the spread of viruses, but so far, none have been described in BSFs. To fill this knowledge gap, a bioinformatic approach was undertaken to discover viruses specifically associated with BSFs. First, BSF genomes were screened for the presence of endogenous viral elements (EVEs). This led to the discovery and mapping of seven orthologous EVEs integrated into three BSF genomes originating from five viral families. Secondly, a virus discovery pipeline was used to screen BSF transcriptomes. This led to detecting a new exogenous totivirus that we named hermetia illucens totivirus 1 (HiTV1). Phylogenetic analyses showed this virus belongs to a clade of insect-specific totiviruses and is closely related to the largest EVE located on chromosome 1 of the BSF genome. Lastly, this EVE was found to express a small transcript in some BSFs infected by HiTV1. Altogether, this data mining study showed that far from being unscathed from viruses, BSFs bear traces of past interactions with several viral families and of present interactions with the exogenous HiTV1.
Specific Recognition of the 5′-Untranslated Region of West Nile Virus Genome by Human Innate Immune System
Authors: Bignon Emmanuelle , Marazzi Marco , Miclot Tom , Barone Giampaolo , Monari Antonio
Published: June 2022

In the last few years, the sudden outbreak of COVID-19 caused by SARS-CoV-2 proved the crucial importance of understanding how emerging viruses work and proliferate, in order to avoid the repetition of such a dramatic sanitary situation with unprecedented social and economic costs. West Nile Virus is a mosquito-borne pathogen that can spread to humans and induce severe neurological problems. This RNA virus caused recent remarkable outbreaks, notably in Europe, highlighting the need to investigate the molecular mechanisms of its infection process in order to design and propose efficient antivirals. Here, we resort to all-atom Molecular Dynamics simulations to characterize the structure of the 5′-untranslated region of the West Nile Virus genome and its specific recognition by the human innate immune system via oligoadenylate synthetase. Our simulations allowed us to map the interaction network between the viral RNA and the host protein, which drives its specific recognition and triggers the host immune response. These results may provide fundamental knowledge that can assist further antivirals’ design, including therapeutic RNA strategies.
The Mediating Role of the Perceived COVID-19 Vaccine Benefits: Examining Israeli Parents’ Perceptions Regarding Their Adolescents’ Vaccination
Authors: Bord Shiran , Satran Carmit , Schor Ayelet
Published: June 2022

Israel was among the first countries to initiate adolescent COVID-19 vaccination. As adolescent vaccination requires parental consent, we evaluated the factors associated with parents’ willingness to vaccinate their adolescents and their point of view regarding adolescents’ involvement in this decision. An online survey was completed by 581 parents of adolescents aged 16–18. The main independent variables included trust in the healthcare system, components of the Health Belief Model (HBM) and adolescents’ involvement in the decision, as well as background data, including demographics. Analysis included a multiple logistic regression and mediation examination. Parents reported that 446 adolescents (76.8%) have been or will soon be vaccinated against COVID-19, 12.2% chose not to vaccinate their child and 11% have not yet decided. Vaccination was significantly associated with HBM components and with adolescents’ involvement in the decision. The perceived vaccination benefits acted as a mediator in the association between parents’ COVID-19 perceived threat and adolescent vaccination, as well as between parents’ trust in the healthcare system and adolescent vaccination. Addressing vaccination benefits and barriers is pivotal in the attempt to enhance adolescents’ vaccination adherence. Considering the importance of adolescents’ involvement in the decision, addressing them directly may also be beneficial in improving vaccination rates.
Effect of a Third Dose of SARS-CoV-2 mRNA BNT162b2 Vaccine on Humoral and Cellular Responses and Serum Anti-HLA Antibodies in Kidney Transplant Recipients
Authors: Cassaniti Irene , Gregorini Marilena , Bergami Federica , Arena Francesca , Sammartino Josè Camilla , Percivalle Elena , Soleymaninejadian Ehsan , Abelli Massimo , Ticozzelli Elena , Nocco Angela , Minero Francesca , Pattonieri Eleonora Francesca , Lilleri Daniele , Rampino Teresa , Baldanti Fausto
Published: June 2022

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has severely impacted on public health, mainly on immunosuppressed patients, including solid organ transplant recipients. Vaccination represents a valuable tool for the prevention of severe SARS-CoV-2 infection, and the immunogenicity of mRNA vaccines has been evaluated in transplanted patients. In this study, we investigated the role of a third dose of the BNT162b2 vaccine in a cohort of kidney transplant recipients, analyzing both humoral and cell-mediated responses. We observed an increased immune response after the third dose of the vaccine, especially in terms of Spike-specific T cell response. The level of seroconversion remained lower than 50% even after the administration of the third dose. Mycophenolate treatment, steroid administration and age seemed to be associated with a poor immune response. In our cohort, 11/45 patients experienced a SARS-CoV-2 infection after the third vaccine dose. HLA antibodies appearance was recorded in 7 out 45 (15.5%) patients, but none of the patients developed acute renal rejection. Further studies for the evaluation of long-term immune responses are still ongoing, and the impact of a fourth dose of the vaccine will be evaluated.
Comparison of COVID-19 Resilience Index and Its Associated Factors across 29 Countries during the Delta and Omicron Variant Periods
Authors: Huy Le Duc , Shih Chung-Liang , Chang Yao-Mao , Nguyen Nhi Thi Hong , Phuc Phan Thanh , Ou Tsong-Yih , Huang Chung-Chien
Published: June 2022

Our study aims to compare the pandemic resilience index and explore the associated factors during the Delta and Omicron variant periods. In addition, the study aims to identify the characteristics of countries that had good performances. We analyzed observation data among 29 countries over the first eight weeks during the two periods of Delta and Omicron variant dominance. Data were extracted from open public databases. The Omicron variant caused a lowered mortality rate per 100,000 COVID-19 patients; however, it is still imposing a colossal burden on health care systems. We found the percentage of the population fully vaccinated and high government indices were significantly associated with a better resilience index in both the Delta and Omicron periods. In contrast, the higher death rate of cancers and greater years lived with disability (YLD) caused by low bone density were linked with poor resilience index in the Omicron periods. Over two periods of Delta and Omicron, countries with good performance had a lower death rate from chronic diseases and lower YLD caused by nutrition deficiency and PM2.5. Our findings suggest that governments need to keep enhancing the vaccine coverage rates, developing interventions for populations with chronic diseases and nutrition deficiency to mitigate COVID-19 impacts on these targeted vulnerable cohorts.
CFD Analysis of the Location of a Rear Wing on an Aston Martin DB7 in Order to Optimize Aerodynamics for Motorsports
Authors: O’Driscoll Thomas P. , Barron Andrew R.
Published: June 2022

The purpose of this study is to identify the initial lateral and vertical location and angle of attack of a GT4-style rear wing on the rear downforce for an Aston Martin DB7 Vantage, prior to installation. The tests were completed with a two-dimensional model, using the Computational Fluid Dynamics (CFD) software, Fluent Ansys. The tests were completed using a range of velocities: 60–80 mph. Optimization of the position of the rear wing aerodynamic device was permitted under the Motorsport UK rules for multiple race series. The results show that while the drag decreases the farther back the wing is located, the desired configuration for the rear wing with regard to downforce is when it is positioned ca. 1850 mm back from the center point of the car, with an attack angle of 5°. Unusually, this is to the front of the boot/rear deck, but it is remarkably similar to where Aston Martin set the rear wing on their Le Mans car in 1995, above where the rear windscreen met the boot hinge, which was based upon wind tunnel studies using a scale model. Our results suggest that while 2D simulations of these types cannot give absolute values for downforce due to aerodynamic device location, they can provide low costs, fast simulation time, and a route for a wide range of cars, making the approach accessible to club motorsports, unlike complex 3D simulation and wind tunnel experimentation.
Innovative Use of Olive, Winery and Cheese Waste By-Products as Functional Ingredients in Broiler Nutrition
Authors: Bonos Eleftherios , Skoufos Ioannis , Petrotos Konstantinos , Giavasis Ioannis , Mitsagga Chrysanthi , Fotou Konstantina , Vasilopoulou Konstantina , Giannenas Ilias , Gouva Evangelia , Tsinas Anastasios , D’Alessandro Angela Gabriella , Cardinali Angela , Tzora Athina
Published: June 2022

The purpose of this study was to evaluate the dietary use of novel silage that was created by combining three agro-industrial wastes produced in bulk, i.e., olive mill wastewater, grape pomace, and deproteinized feta cheese whey, in the diets of broiler chickens. A total of 216 one-day-old male Ross-308 chicks were randomly allocated to three treatment groups with six replications (12 chicks per pen). Three isocaloric and isonitrogenous diets were formulated to include the examined silage at 0%, 5%, or 10%. Commercial breeding and management procedures were employed throughout the trial. At the end of the trial (day 35), tissue samples were collected for analysis. Feeding 10% silage resulted in increased (p ≤ 0.001) final body weight (p ≤ 0.001) and feed intake. Jejunum and cecum microflora, as well as breast and thigh meat microflora, were modified (p ≤ 0.05) by the dietary inclusion. Thigh meat oxidative stability was improved (p < 0.01) by the silage supplementation. In addition, breast and thigh meat fatty acid profiles were different, respectively, (p < 0.05) in the supplemented treatments compared to the control. The examined silage was successfully tested in broiler diets with potential benefits for their performance and meat quality.
Deep Gaussian Process for the Approximation of a Quadratic Eigenvalue Problem: Application to Friction-Induced Vibration
Authors: Sadet Jeremy , Massa Franck , Tison Thierry , Talbi El-Ghazali , Turpin Isabelle
Published: June 2022

Despite numerous works over the past two decades, friction-induced vibrations, especially braking noises, are a major issue for transportation manufacturers as well as for the scientific community. To study these fugitive phenomena, the engineers need numerical methods to efficiently predict the mode coupling instabilities in a multiparametric context. The objective of this paper is to approximate the unstable frequencies and the associated damping rates extracted from a complex eigenvalue analysis under variability. To achieve this, a deep Gaussian process is considered to fit the non-linear and non-stationary evolutions of the real and imaginary parts of complex eigenvalues. The current challenge is to build an efficient surrogate modelling, considering a small training set. A discussion about the sample distribution density effect, the training set size and the kernel function choice is proposed. The results are compared to those of a Gaussian process and a deep neural network. A focus is made on several deceptive predictions of surrogate models, although the better settings were well chosen in theory. Finally, the deep Gaussian process is investigated in a multiparametric analysis to identify the best number of hidden layers and neurons, allowing a precise approximation of the behaviours of complex eigensolutions.
Influence of Rural Development of River Tourism Resources on Physical and Mental Health and Consumption Willingness in the Context of COVID-19
Authors: Lin Hsiao-Hsien , Ting Kuo-Chiang , Huang Jen-Min , Chen I-Shen , Hsu Chin-Hsien
Published: June 2022

This study took the Three Gorges Dam as an example and discussed the influence of river regulation decisions on the sustainable development of surrounding villages. The study used mixed research methods, snowball sampling, and convenience sampling to obtain samples. The questionnaire samples were analyzed by basic statistical tests, t-test, and structural equation modeling (SEM). The respondents’ opinions were collected through semi-structured interviews and finally the results were discussed by multivariate analysis. The findings were that even though the villages were not well developed in terms of economy, environment, and natural ecology, as long as the community security could be stable, the living could be safe and convenient, people’s daily life patterns and leisure behaviors could be maintained, and people could stabilize their minds and emotions and maintain physical and mental health in order to meet their living needs and reduce the burden. There would be time and funds to invest in leisure, tourism activities, and consumption behavior. If the above consumption patterns are continued, people will gain positive perceptions, stimulating people’s willingness to invest in property purchases or to make travel plans again.
Extensive Wastewater-Based Epidemiology as a Resourceful Tool for SARS-CoV-2 Surveillance in a Low-to-Middle-Income Country through a Successful Collaborative Quest: WBE, Mobility, and Clinical Tests
Authors: Sosa-Hernández Juan Eduardo , Oyervides-Muñoz Mariel Araceli , Melchor-Martínez Elda M. , Driver Erin M. , Bowes Devin A. , Kraberger Simona , Lucero-Saucedo Sofia Liliana , Fontenele Rafaela S. , Parra-Arroyo Lizeth , Holland LaRinda A. , Peña-Benavides Samantha Ayde , Newell Melanie Engstrom , Martínez-Ruiz Manuel , Adhikari Sangeet , Rodas-Zuluaga Laura Isabel , Kumar Rahul , López-Pacheco Itzel Y. , Castillo-Zacarias Carlos , Iqbal Hafiz M. N. , Lim Efrem S. , Salas-Limón Daniel , Varsani Arvind , Halden Rolf U. , Parra-Saldívar Roberto
Published: June 2022

The COVID-19 pandemic has challenged healthcare systems worldwide. Efforts in low-to-middle-income countries (LMICs) cannot keep stride with infection rates, especially during peaks. A strong international collaboration between Arizona State University (ASU), Tec de Monterrey (TEC), and Servicios de Agua y Drenaje de Monterrey (Local Water Utilities) is acting to integrate wastewater-based epidemiology (WBE) of SARS-CoV-2 in the region as a complementary approach to aid the healthcare system. Wastewater was collected from four sewer catchments in the Monterrey Metropolitan area in Mexico (pop. 4,643,232) from mid-April 2020 to February 2021 (44 weeks, n = 644). Raw wastewater was filtered and filter-concentrated, the RNA was extracted using columns, and the Charité/Berlin protocol was used for the RT-qPCR. The viral loads obtained between the first (June 2020) and second waves (February 2021) of the pandemic were similar; in contrast, the clinical cases were fewer during the first wave, indicating poor coverage. During the second wave of the pandemic, the SARS-CoV-2 quantification in wastewater increased 14 days earlier than the COVID-19 clinical cases reported. This is the first long-term WBE study in Mexico and demonstrates its value in pandemic management.
A Framework to Support the Selection of an Appropriate Water Allocation Planning and Decision Support Scheme
Authors: Nel Johannes B. , Mativenga Paul T. , Marnewick Annlizé L.
Published: June 2022

Water is becoming a scarce resource in many parts of the world, leading to increased competition amongst water users. Optimized water allocation is increasingly important to balance the growing demand for water and the limited supply of accessible clean water. The literature on water allocation schemes and decision support systems, developed for application in specific water management areas or watersheds, was critically reviewed. Although the literature is rich in studies on the application of a broad range of water allocation schemes, there is a lack of information available on the methodology and process of selecting the most applicable scheme that balances the local realities and requirements of stakeholders while considering the local context with regard to the economic, social and environmental impact of water usage. In this article, a framework is presented that water management practitioners can use to select applicable water allocation planning schemes and associated decision support systems based on the characteristics and requirements of the specific water management situation. The framework was used to analyse the water supply situation in South Africa (SA), taking broader factors into account. Based on this, a generic conceptualized water allocation planning and decision support framework for a typical SA water management area is proposed.
Machine Learning and Multiple Imputation Approach to Predict Chlorophyll-a Concentration in the Coastal Zone of Korea
Authors: Kim Hae-Ran , Soh Ho Young , Kwak Myeong-Taek , Han Soon-Hee
Published: June 2022

The concentration of chlorophyll-a (Chl-a) is an integrative bio-indicator of aquatic ecosystems and a direct indicator that evaluates the ecological status of water bodies. In this study, we focused on predicting the Chl-a concentration in seawater using machine learning (after replacing missing values). To replace the missing values among marine environment observation data, a comparison experiment was performed using multiple built-in imputation methods (i.e., pmm, cart, rf, norm, norm.nob, norm.boot, and norm.predict) of the mice package in R. The cart method was selected as the most suitable. We generated each regression model using six machine learning algorithms (regression tree, support vector regression (SVR), bagging, random forest, gradient boosting machine (GBM), and extreme gradient boosting (XGBoost)) to predict the Chl-a concentration based on the complete imputed dataset. The prediction performance of the models was evaluated by four evaluation criteria using 10-fold cross-validation tests. XGBoost, an ensemble learning approach, outperformed other models in predicting the Chl-a concentration; SVR, a single model, also showed a good performance. The most important environmental factor in predicting the Chl-a concentration was an organic carbon particulate; however, dissolved oxygen also showed potential. This study was conducted with field observations in the spring and summer in the coastal zone of Korea. There exists a limit in machine learning applications, which excludes temporal and spatial factors. However, extensions to time series forecasting for deep learning or machine learning can lead to meaningful regional and seasonal analysis. It can also improve prediction performance as a result of the long-term data accumulation of field observations of more varied features (such as meteorological and hydrodynamic) besides water quality.
Grid-Point Rainfall Trends, Teleconnection Patterns, and Regionalised Droughts in Portugal (1919–2019)
Authors: Espinosa Luis Angel , Portela Maria Manuela
Published: June 2022

This paper describes the long-term grid-point rainfall trends in the context of climate change, recent regionalised rainfall decline and drought events for mainland Portugal, which is teleconnected, in most cases, to the trends of mathematical descriptions of the North Atlantic Oscillation (NAO) during the century from October 1919 to September 2019. Grid-point rainfall dataset (1919–2019, from 126 centroids in a regular mesh over the country) have been constructed from high-quality ground-based data and as such, it provides a reliable source for the analysis of rainfall trends at different timescales: October–December, January–March, December–March, and the hydrological year. The Mann–Kendall (MK) coupled with Sen’s slope estimator test are applied to quantify the trends. The Sequential Mann–Kendall (SQMK) analysis is implemented to obtain the fluctuation of the progressive trends along the studied 100-year period. Because of their pivotal role in linking and synchronising climate variability, teleconnections to the North Atlantic Ocean are also explored to explain the rainfall trends over the Portuguese continuum. The results provide a solid basis to explain the climate change effects on the Portuguese rainfall based on significant associations with strong negative correlations between changes in rainfall and in NAO indices. These strong opposing correlations are displayed in most of the winter seasons and in the year. After the late 1960s, a generalised rainfall decrease emerges against a background of significant upward trends of the NAO; such coupled behaviour has persisted for decades. Regionalised droughts at three identified climatic regions, based on factor analysis and Standardised Precipitation Index (SPI), are also discussed, concluding that the frequency of severe droughts may increase again, accompanied by a stronger influence of the recently more positive and unusual winter season and annual NAO indices.
Correction: Qiu et al. Detection and Quantification of Dam Leakages Based on Tracer Tests: A Field Case Study. Water 2022, 14, 1448
Authors: Qiu Huiyang , Hu Rui , Huang Yong , Gwenzi Willis
Published: June 2022

In the original publication [...]
Delimiting Pig Slurry Affected Subsurface Areas by Combining Geophysical and Geochemical Techniques
Authors: Capa-Camacho Ximena , Martínez-Pagán Pedro , Martínez-Segura Marcos A. , Gabarrón María , Faz Ángel
Published: June 2022

In Spain, livestock farming is a significant activity area that generates substantial revenues and essential jobs. However, the actual impact that this intensive activity might have on the environment is not entirely understood. Moreover, coastal aquifers are subjected to a significant environmental pressure due to nearby growing population, intensive agriculture, and livestock farming. In this work, three representative pig slurry ponds, under semiarid conditions, were studied using different techniques to evaluate the subsurface conditions in terms of pH, electrical conductivity, salts, and nitrate content. The electrical resistivity tomography (ERT) technique was employed in this study, which provides electrical resistivity values from the subsurface materials and fluids. These electrical resistivity values were compared to data obtained from geochemical analyses to derive their relationships and establish the pig slurry-affected subsurface area. Thus, ERT-based lower electrical resistivity values were associated with higher salts concentrations and nitrate content. ERT values indicated a near-surface affected by slurry infiltration that coincided with the increase of geochemical values obtained from sample analyses. Additionally, Spearman’s correlation was used to evaluate the correlation between electrical resistivity data and the physical-chemical properties of soil. The most important pollutant accumulation mainly occurs in the two-meter depth. Therefore, the risk of slurry ponds affecting deep aquifers is limited in the studied area. Finally, this study proves a complete, affordable, and scalable methodology application to livestock residue storage facilities.
Hydrochemical Characteristics and Formation Mechanism of Strontium-Rich Groundwater in Tianjiazhai, Fugu, China
Authors: Liang Chengcheng , Wang Wei , Ke Xianmin , Ou Anfeng , Wang Dahao
Published: June 2022

Strontium-rich groundwater exists in the underlying carbonate rocks of the Tianjiazhai Shimachuan River basin, Fugu, China. In this study, the hydrochemical characteristics and formation mechanisms of Sr-rich groundwater were assessed using mathematical statistics and traditional water chemistry, combining geological and hydrogeological conditions, as well as hydrogeochemical theory. The results showed that the Sr2+ content range in Sr-rich groundwater was 0.85~2.99 mg·L−1, which is weakly alkaline fresh water. HCO3− Ca·Mg·Na was the main facies type of Sr-rich groundwater. Sr-rich groundwater has relatively stable contents of chemical elements. The water–rock interaction was the main factor controlling the hydrochemical characteristics of Sr-rich groundwater, particularly carbonate dissolution, influenced by some degree of cation exchange. The Sr element in groundwater mainly comes from the dissolution of the sandstone of the Yanchang Formation. The higher the degree of weathering and the longer the water–rock reaction time, the more favorable the dissolution and enrichment of Sr in groundwater. Moreover, the large weathering thickness and fracture development of the rocks in the Tianjiazhai area provide favorable conditions for the formation of Sr-rich groundwater. The results of this study provide a scientific basis for developing effective policies to protect Sr-rich groundwater resources.
Erosion-Transportation Processes Influenced by Spatial Distribution of Terraces in Watershed in the Loess Hilly–Gully Region (LHGR), China
Authors: Gao Zhe , Zhang Genguang , Fan Henghui , Ji Qianqian , Li Anbin , Zhang Yuanyuan , Feng Boyan , Yu Yuanhao , Ma Lin , Gao Jianen
Published: June 2022

How to optimize the spatial distribution of terraces in the watershed is an important scientific problem. It was researched through a watershed solid-scale physical model based on the 3D reappearance of a scene under the Cartesian coordinate system, with the lowest point of the watershed as the origin. The results showed that the change of the spatial pattern of terraced fields in the basin had an important impact on the production of runoff and sediment. There was an approximate quadratic-function relationship between the spatial location and the parameters of runoff and confluence. If Rt was terrace-erosion-reduction benefit, it could be defined as the reduction in the watershed-erosion modulus per unit of terrace area. The longitudinal distribution of Rt was upper and middle > lower parts, and the vertical distribution of Rt was high > low place. The erosion reduction was 77.67% of the terraces of the middle and upper, occupying 33% of the watershed area. The change of the Rt was logarithmically related to the relative distance (r) from the center of the terrace. When r was around 0.35, there was an inflection point in Rt growth. The results of this study have important practical significance for the planning and construction of terraces in the watershed.
Measurement of Water Soil Erosion at Sparacia Experimental Area (Southern Italy): A Summary of More than Twenty Years of Scientific Activity
Authors: Pampalone Vincenzo , Carollo Francesco Giuseppe , Nicosia Alessio , Palmeri Vincenzo , Di Stefano Costanza , Bagarello Vincenzo , Ferro Vito
Published: June 2022

The main purpose of this article is to give a general idea of the scientific activity that was carried out starting from the 2000s on the basis of the data collected in the plots installed at the Sparacia experimental station for soil erosion measurement in Sicily, South Italy. The paper includes a presentation of the experimental site, a description of the methods and procedures for measuring soil erosion processes both available in the literature and applied at the Sparacia station (sediment sampling and water level reading in the storage tanks for total erosion measurements; profilometer, and Structure from Motion technique for rill erosion measurements), and the main results obtained in the monitoring period in the experimental site. The latter concern the effects of plot size and steepness on soil loss, the measurement variability, the frequency analysis of soil loss, the rill erosion characterization, and the comparison between rill and interrill erosion rates. Each of these topics is addressed with multi-temporal analyses performed with increasing size of the available database, which allowed to draw robust conclusions. Soil loss did not vary appreciably with plot length in contrast with the assumption made in the USLE/RUSLE. The variability of the measurements of soil loss, runoff volume, and sediment concentration at the event scale in replicated plots decreased as the mean measured value increased. The normalized event soil loss was distributed according to a two-component distribution. A power relationship between rill volumes and lengths was established. The measurements also confirmed the morphological similarity between the channels of the rills and ephemeral gullies described by a power dimensionless relationship. Rill erodibility of the sampled clay soil varied over time, maintaining relatively low values. Finally, rill erosion was dominant relative to interrill erosion, and a more efficient sediment transport system through the rill network occurred as plot steepness increased.
A Python Application for Visualizing the 3D Stratigraphic Architecture of the Onshore Llobregat River Delta in NE Spain
Authors: Bullejos Manuel , Cabezas David , Martín-Martín Manuel , Alcalá Francisco Javier
Published: June 2022

This paper introduces a Python application for visualizing the 3D stratigraphic architecture of porous sedimentary media. The application uses the parameter granulometry deduced from borehole lithological records to create interactive 3D HTML models of essential stratigraphic elements. On the basis of the high density of boreholes and the subsequent geological knowledge gained during the last six decades, the Quaternary onshore Llobregat River Delta (LRD) in northeastern Spain was selected to show the application. The public granulometry dataset produced by the Water Authority of Catalonia from 433 boreholes in this strategic coastal groundwater body was clustered into the clay–silt, coarse sand, and gravel classes. Three interactive 3D HTML models were created. The first shows the location of the boreholes granulometry. The second includes the main gravel and coarse sand sedimentary bodies (lithosomes) associated with the identified three stratigraphic intervals, called lower (>50 m b.s.l.) in the distal LRD sector, middle (20–50 m b.s.l.) in the central LRD, and upper (<20 m b.s.l.) spread over the entire LRD. The third deals with the basement (Pliocene and older rocks) top surface, which shows an overall steeped shape deepening toward the marine platform and local horsts, probably due to faulting. The modeled stratigraphic elements match well with the sedimentary structures reported in recent scientific publications. This proves the good performance of this incipient Python application for visualizing the 3D stratigraphic architecture, which is a crucial stage for groundwater management and governance.
Chemical Oxidation and Reduction Pathways of Mercury Relevant to Natural Waters: A Review
Authors: Si Lin , Branfireun Brian A. , Fierro Jessica
Published: June 2022

Mercury (Hg) pollution in the environment is a global issue and the toxicity of mercury depends on its speciation. Chemical redox reactions of mercury in an aquatic environment greatly impact on Hg evasion to the atmosphere and the methylation of mercury in natural waters. Identifying the abiotic redox pathways of mercury relevant to natural waters is important for predicting the transport and fate of Hg in the environment. The objective of this review is to summarize the current state of knowledge on specific redox reactions of mercury relevant to natural waters at a molecular level. The rate constants and factors affecting them, as well as the mechanistic information of these redox pathways, are discussed in detail. Increasing experimental evidence also implied that the structure of natural organic matter (NOM) play an important role in dark Hg(II) reduction, dark Hg(0) oxidation and Hg(II) photoreduction in the aquatic environment. Significant photooxidation pathways of Hg(0) identified are Hg(0) photooxidation by hydroxyl radical (OH•) and by carbonate radical (CO3−•). Future research needs on improving the understanding of Hg redox cycling in natural waters are also proposed.