bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring and Mathematical Modeling of Soil and Groundwater Contamination by Harmful Emissions of Nitrogen Dioxide from Motor Vehicles
Authors: Dyvak Mykola , Rot Artur , Pasichnyk Roman , Tymchyshyn Vasyl , Huliiev Nazar , Maslyiak Yurii
Published: March 2021

The article considers the task and a new approach to monitoring of soil and groundwater contamination by harmful emissions of nitrogen dioxide from motor vehicles. The approach is based on combination of measurement procedure of the harmful emissions concentrations in the surface atmospheric layer and mathematical modeling of the impact of these emissions on soil and groundwater contamination. The scheme of this harmful emission concentrations measurement using a mobile complex Sniffer4D Hyper-local Air Quality Analyzer is given. Based on these results, a mathematical model of diffusion of this harmful substance in the upper layers of soil and water resources is proposed. As a result of the computations, the distribution of concentrations of soil and water contamination in the neighborhood of separate observation points has been built. Also, the field of nitrogen dioxide concentrations at various depths for observation points has been modeled. For a waterbody, the concentration of nitric acid, which is formed due to the interaction of nitrogen dioxide with water, is higher in water than in the surface layer of the soil. This concentration can be significantly increased during prolonged downpours when acidic solutions drain from surrounding soil areas into the waterbodies. The obtained research results are fully consistent with the practical and theoretical results on the diffusion of gases into soils and water resources. It means that the proposed approach can be used instead of the existing very expensive approach to analysis of soil and groundwater contamination in the laboratory.
A Case Study of a Robot-Assisted Speech Therapy for Children with Language Disorders
Authors: Estévez David , Terrón-López María-José , Velasco-Quintana Paloma J. , Rodríguez-Jiménez Rosa-María , Álvarez-Manzano Valle
Published: March 2021

The aim of this study was to explore the potential of using a social robot in speech therapy interventions in children. A descriptive and explorative case study design was implemented involving the intervention for language disorder in five children with different needs with an age ranging from 9 to 12 years. Children participated in sessions with a NAO-type robot in individual sessions. Qualitative methods were used to collect data on aspects of viability, usefulness, barriers and facilitators for the child as well as for the therapist in order to obtain an indication of the effects on learning and the achievement of goals. The main results pointed out the affordances and possibilities of the use of a NAO robot in achieving speech therapy and educational goals. A NAO can contribute towards eliciting motivation, readiness towards learning and improving attention span of the children. The results of the study showed the potential that NAO has in therapy and education for children with different disabilities. More research is needed to gain insight into how a NAO can be applied best in speech therapy to make a more inclusive education conclusions.
Online Tourist Behavior of the Net Generation: An Empirical Analysis in Taiwan Based on the AISAS Model
Authors: Xue Lin-Lin , Shen Ching-Cheng , Morrison Alastair M. , Kuo Li-Wen
Published: March 2021

This study was intended to investigate the online behavior of Taiwan’s Net Generation (born between 1977 and 1997) based on Dentsu’s AISAS (Attention-Interest-Search-Action-Share) model. A conceptual framework and several hypotheses were developed and tested. A questionnaire survey was conducted in Taiwan in 2018 with 338 valid responses being received. The data were analyzed through linear regression analysis with learning and growth set as the dependent variable. Information search was the key action variable and especially during travel. Attention and interest had significant indirect influences on actions, which impacted sharing, learning, and growth. Learning and growth and action increased sharing. Post-travel sharing stimulated attention and was a catalyst for another cycle of AISAS. This research intended to fill a gap in the literature by examining the relationships among stages in the online purchase and consumption of travel products and services.
The Antecedents and Consequences of Rapport between Customers and Salespersons in the Tourism Industry
Authors: Hwang Jinsoo , Lee Kwang-Woo , Kim Seongseop (Sam)
Published: March 2021

This study examined the antecedents and consequences of rapport between customers and salespersons in the context of duty-free shops. Specifically, this study proposed six sub-dimensions of service-dominant orientation (i.e., relational, ethical, individuated, empowered, concerted, and developmental interactions). These dimensions have a positive influence on rapport. In addition, rapport is hypothesized to aid in the formation of customer satisfaction and brand preference, which in turn positively affects word-of-mouth communications. Data were collected from 649 Chinese shoppers who have purchased a product in a Korean duty-free shop. In addition, this study employed confirmatory factor analysis to check the adequacy of the measurement items and structural equation modeling to test 11 hypotheses. Data analysis results indicated that five sub-dimensions of service-dominant orientation, excluding individuated interaction, play an important role in the formation of rapport. Furthermore, rapport has a positive effect on customer satisfaction and brand preference, which in turn positively affects word-of-mouth communications. The findings of this study offer valuable insights for managers of duty-free stores into the most effective methods for managing their operations and providing an appropriate blend of products. Furthermore, this paper contributes to theoretical understanding in this area by improving the acceptability of a commonly believed shopper behavior model.
Exploring Smallholder Farmers’ Preferences for Climate-Smart Seed Innovations: Empirical Evidence from Southern Ethiopia
Authors: Geda Shimelis Araya , Kühl Rainer
Published: March 2021

Rapid plant breeding is essential to overcome low productivity problems in the face of climatic challenges. Despite considerable efforts to improve breeding practices in Ethiopia, increasing varietal release does not necessarily imply that farmers have access to innovative varietal choices. Prior research did not adequately address whether varietal attributes are compatible with farmers’ preferences in harsh environmental conditions. With an agricultural policy mainly aiming to achieve productivity maximization, existing breeding programs prioritize varietal development based on yield superiority. Against this background, we estimated a multinomial logit (MNL) model based on choice-experiment data from 167 bean growers in southern Ethiopia to explore whether farmers’ attribute preferences significantly diverge from those of breeders’ priorities. Four important bean attributes identified through participatory research methods were used. The results demonstrate that farmers have a higher propensity toward drought-tolerant capability than any of the attributes considered. The model estimates further show the existence of significant preference heterogeneity across farmers. These findings provide important insight to design breeding profiles compatible with specific producer segments. We suggest demand-driven breeding innovations and dissemination strategies in order to accelerate the adoption of climate-smart and higher-yielding bean innovations that contribute to achieve the national and global sustainability goals in Ethiopia.
Exploring the Impacts of Student-Led Sustainability Projects with Secondary School Students and Teachers
Authors: Vare Paul
Published: March 2021

Secondary school students are granted few opportunities to change their world, yet they are expected to engage fully as citizens the moment they leave school. This issue is growing starker with multiple global crises contributing to mental health concerns. This situation stimulated a practical education for sustainability project designed to promote student agency by supporting small, student-led, community-based projects, planned and supported within the secondary school context. This research ran alongside the project in order to investigate (a) the impact of implementing these projects on the students involved and (b) the implications of this for their teachers. The research approach was based on Cultural-historical Activity Theory, which explores the learning generated through multi-layered interactions within a given activity system. In stimulating student agency, it was clear that the project had challenged existing practice. Students sensed a shift in power relations, remarking on how teachers respected and listened to their opinions. Those teachers who appeared more authoritarian appeared to experience the greatest transformation although ceding power did not come naturally, particularly where this challenged notions around teacher responsibility. In this way, teachers’ professionalism threatened to become the means by which they withheld power from their students. Implications of this for schools and policy are considered.
Sustainable Urban Drainage Systems in Spain: A Diagnosis
Authors: Andrés-Doménech Ignacio , Anta Jose , Perales-Momparler Sara , Rodriguez-Hernandez Jorge
Published: March 2021

Sustainable urban drainage systems (SUDS) were almost unknown in Spain two decades ago; today, urban drainage in the country is transitioning towards a more sustainable and regenerative management in a global context where green policies are gaining prominence. This research establishes a diagnosis of SUDS in Spain and examines the extent to which the country is moving towards the new paradigm in three dimensions: (a) the governance and social perception of the community, (b) the regulative background, and (c) the implementation and the technical performance of SUDS. The diagnosis identifies barriers that hinder the change. Then, we define the challenges that Spain has to face to overcome obstacles that delay the transition. Barriers to the governance sphere are related to the lack of involvement, knowledge, and organisational responsibilities. Within the regulative framework, the absence of national standards hinders the general implementation at the national scale, although few regional and local authorities are taking steps in the right direction with their own regulations. From the technical perspective, SUDS performance within the Spanish context was determined, although some shortcomings are still to be investigated. Despite the slowdown caused by the hard recession periods and the more recent political instability, SUDS implementation in Spain is today a fact, and the country is close to reaching the stabilisation stage.
A Study on the Practical Pressure-Driven Hydraulic Analysis Method Considering Actual Water Supply Characteristics of Water Distribution Network
Authors: Chang Dong Eil , Yoo Do Guen , Kim Joong Hoon
Published: March 2021

For reliable pressure-driven analysis (PDA) results, it is necessary to reasonably determine an objective head-outflow relationship (HOR) and the required head for each node. So far, no methodology has been proposed to objectively determine two factors based on data of real block. In this study, the HOR was defined using the water supply method, residential environment, and water consumption data within real blocks. The standard minimum residual pressure criteria were reviewed to quickly and rationally determine the required head for each node. To validate the proposed methodology, the HOR and required head application conditions were configured for different scenarios; the available flow rate of nodes and the water supply capacity of the entire block were evaluated based on PDA results. Through the results for each scenario, the HOR definition method was able to provide a reasonable result reflecting the actual block’s conditions, unlike the conventional orifice-type HOR, and the standard minimum residual pressure criteria as the required head was evaluated to be more efficient than the conventional time-consuming method. The HOR uncertainty and the lack of rationality in the selection of the required heads affected the reliability of PDA results; these problems can be solved using the proposed methodology.
Fish Farmers’ Perception of Ecosystem Services and Diversification of Carp Pond Aquaculture: A Case Study from Warmia and Mazury, Poland
Authors: Turkowski Konrad
Published: March 2021

Ecosystem services, multifunctionality and diversity play a particular role in the management of carp pond aquaculture. These three concepts have been increasingly considered in sustainable aquaculture science and policymaking. However, the understanding and acceptance of sustainable aquaculture by fish farmers is a prerequisite for the successful implementation of such a targeted policy. Research on a fish farmers’ perception of ecosystem services, multifunctionality and diversification of carp aquaculture was carried out in Warmia and Mazury, Poland. The results of interviews showed that farmers have a deep understanding of the ecosystem services and multifunctionality of carp ponds. Production services were indicated as the most important, but the role of ponds in the preservation of biodiversity was another highly valued service. The greatest diversity of the activities, and conviction of their significant impact on the profitability of carp pond farming, was observed on farms with ponds of 1 to 50 ha. In the case of larger farms, the assessment of such impact was more moderate. All surveyed farms provided educational services regarding the ecological values of the ponds. All pond users, regardless of their size, highly rated the need for financial support for the conservation and development of biodiversity.
Safeguarding Free-Flowing Rivers: The Global Extent of Free-Flowing Rivers in Protected Areas
Authors: Opperman Jeffrey J. , Shahbol Natalie , Maynard Jeffrey , Grill Günther , Higgins Jonathan , Tracey Dieter , Thieme Michele
Published: March 2021

Approximately one-third of long rivers remain free-flowing, and rivers face a range of ongoing and future threats. In response, there is a heightened call for actions to reverse the freshwater biodiversity crisis, including through formal global targets for protection. The Aichi Biodiversity Targets called for the protection of 17% of inland water areas by 2020. Here, we examine the levels and spatial patterns of protection for a specific type of inland water area—rivers designated as free-flowing. Out of a global total of 11.7 million kilometers of rivers, 1.9 million kilometers (16%) are within protected areas and 10.1 million kilometers are classified as free-flowing, with 1.7 million kilometers of the free-flowing kilometers (17%) within protected areas. Thus, at the global level, the proportion of rivers in protected areas is just below the Aichi Target, and the proportion of free-flowing rivers within protected areas equals that target. However, the extent of protection varies widely across river basins, countries, and continents, and many of these geographic units have a level of protection far lower than the target. Further, high discharge mainstem rivers tend to have lower extent of protection. We conclude by reviewing the limitations of measuring river protection by the proportion of river kilometers within protected areas and describe a range of mechanisms that can provide more effective protection. We also propose a set of recommendations for a more comprehensive quantification of global river protection.
The Two-Echelon Dual-Channel Models for the Intermodal Container Terminals of the China Railway Express Considering Container Accumulation Modes
Authors: Guo Shujuan , Diao Cuijie , Li Gang , Takahashi Katsuhiko
Published: March 2021

China Railway Express (CR Express) is a pioneer of the Silk Road Economic Belt and the 21st Century Maritime Silk Road. The intermodal container terminal system consisting of a maritime terminal and a railway terminal is investigated in this paper. It connects the shipping route and the CR Express route. Typically, there are two container accumulation modes in the railway terminal to dispatch a train, i.e., the fixed-length and the fixed-time container accumulation modes. The intermodal container terminal system can be formulated as the two-echelon dual-channel supply chain model. The steady-state probability matrix is obtained by solving the equilibrium equations. The cooperation between the maritime terminal and the railway terminal is considered to accelerate the accumulation of the containers. The total revenue of the two terminals is used as the key system performance indicator. Numerical experiments are conducted to compare the fixed-length and the fixed-time container accommodation modes. The situations with and without cooperation between two terminals are also compared in the two container accumulation modes, respectively.
An Analysis of the Demand-Side, Platform-Based Collaborative Economy: Creation of a Clear Classification Taxonomy
Authors: Kovács Tünde Zita , David Forest , Nagy Adrián , Szűcs István , Nábrádi András
Published: March 2021

The rapid proliferation of the demand-side, platform-based collaborative economy and its various forms have been an aspect of everyday life for over a decade. However, despite the platform’s popularity, the descriptions and names attributed to the demand-side, platform-based collaborative economy are often used interchangeably and can be ambiguous, resulting in confusion among researchers and practitioners. This study examines the articles published during the previous ten years, which have aimed not only to define, but also to classify, the collaborative economy according to various criteria. After reviewing the existing classification criteria, this article presents a clearer taxonomy of the multiple forms of the collaborative economy by distinguishing service providers’ groups on their respective attributes. Our review and analysis have both theoretical and practical importance. Regarding the latter, our research will help managers and government officials alike in rethinking the taxation and subsidizing policies related to the various demand-side, platform-based collaborative economies and in preparing national and international consultations and conventions. This study aims to define the demand-side, platform-based collaborative economy and integrate the concept into various economic activities, providing a new and valuable contribution to the literature.
An MCDM Model for Sustainable Decision-Making in Municipal Residential Buildings Facilities Management
Authors: Klumbytė Eglė , Bliūdžius Raimondas , Medineckienė Milena , Fokaides Paris A.
Published: March 2021

Measuring and monitoring sustainability plays an essential role in impact assessment of global changes and development. Multi-criteria decision-making (MCDM) represents a reliable and adequate technique for assessing sustainability, especially in the field of municipal buildings management, where numerous parameters and criteria are involved. This study presents an MCDM model for the sustainable decision-making, tailored to municipal residential buildings facilities management. The main outcome of this research concerned normalized and weighted decision-making matrixes, based on the complex proportion assessment (COPRAS) and weighted aggregated sum product assessment (WASPAS) methods, applied for ranking investment alternatives related to the management of the buildings. The delivered model was applied to 20 municipal buildings of Kaunas city municipality, located in Lithuania, which an EU member state employing practices and regulations in accordance with the EU acquis, as well as a former Soviet Republic. The proposed model aspires to enhance sustainability practices in the management of municipal buildings and to demonstrate a solid tool that will allow informed decision-making in the building management sector.
A New Technique for Generating Distributions Based on a Combination of Two Techniques: Alpha Power Transformation and Exponentiated T-X Distributions Family
Authors: Klakattawi Hadeel S. , Aljuhani Wedad H.
Published: March 2021

In the following article, a new five-parameter distribution, the alpha power exponentiated Weibull-exponential distribution is proposed, based on a newly developed technique. It is of particular interest because the density of this distribution can take various symmetric and asymmetric possible shapes. Moreover, its related hazard function is tractable and showing a great diversity of asymmetrical shaped, including increasing, decreasing, near symmetrical, increasing-decreasing-increasing, increasing-constant-increasing, J-shaped, and reversed J-shaped. Some properties relating to the proposed distribution are provided. The inferential method of maximum likelihood is employed, in order to estimate the model’s unknown parameters, and these estimates are evaluated based on various simulation studies. Moreover, the usefulness of the model is investigated through its application to three real data sets. The results show that the proposed distribution can, in fact, better fit the data, when compared to other competing distributions.
Numerical Investigation of Time-Fractional Equivalent Width Equations That Describe Hydromagnetic Waves
Authors: Shah Nehad Ali , Dassios Ioannis , Chung Jae Dong
Published: March 2021

The present research article is related to the analytical investigation of some fractional-order equal-width equations. The homotopy perturbation technique along with Elzaki transformation is implemented to discuss the fractional view analysis of equal-width equations. For better understanding of the proposed procedure some examples related to equal-width equations are presented. The identical behavior of the derived and actual solutions is observed. The proposed technique can be modified to study the fractional view analysis of other problems in various areas of applied sciences.
Lorentz Symmetry Group, Retardation and Energy Transformations in a Relativistic Engine
Authors: Rajput Shailendra , Yahalom Asher , Qin Hong
Published: March 2021

In a previous paper, we have shown that Newton’s third law cannot strictly hold in a distributed system of which the different parts are at a finite distance from each other. This is due to the finite speed of signal propagation which cannot exceed the speed of light in vacuum, which in turn means that when summing the total force in the system the force does not add up to zero. This was demonstrated in a specific example of two current loops with time dependent currents, the above analysis led to suggestion of a relativistic engine. Since the system is effected by a total force for a finite period of time this means that the system acquires mechanical momentum and energy, the question then arises how can we accommodate the law of momentum and energy conservation. The subject of momentum conservation was discussed in a pervious paper, while preliminary results regarding energy conservation where discussed in some additional papers. Here we give a complete analysis of the exchange of energy between the mechanical part of the relativistic engine and the field part, the energy radiated from the relativistic engine is also discussed. We show that the relativistic engine effect on the energy is 4th-order in 1c and no lower order relativistic engine effect on the energy exists.
Some Higher-Degree Lacunary Fractional Splines in the Approximation of Fractional Differential Equations
Authors: Srivastava Hari Mohan , Mohammed Pshtiwan Othman , Guirao Juan L. G. , Hamed Y. S.
Published: March 2021

In this article, we begin by introducing two classes of lacunary fractional spline functions by using the Liouville–Caputo fractional Taylor expansion. We then introduce a new higher-order lacunary fractional spline method. We not only derive the existence and uniqueness of the method, but we also provide the error bounds for approximating the unique positive solution. As applications of our fundamental findings, we offer some Liouville–Caputo fractional differential equations (FDEs) to illustrate the practicability and effectiveness of the proposed method. Several recent developments on the the theory and applications of FDEs in (for example) real-life situations are also indicated.
New Applications of the Fractional Integral on Analytic Functions
Authors: Alb Lupaş Alina
Published: March 2021

The fractional integral is a function known for the elegant results obtained when introducing new operators; it has proved to have interesting applications. In the present paper, differential subordinations and superodinations for the fractional integral of the confluent hypergeometric function introduced in a previously published paper are presented. A sandwich-type theorem at the end of the original part of the paper connects the outcomes of the studies done using the dual theories.
2,2-Bis(4-Hydroxyphenyl)-1-Propanol—A Persistent Product of Bisphenol A Bio-Oxidation in Fortified Environmental Water, as Identified by HPLC/UV/ESI-MS
Authors: Drzewiecka Małgorzata , Beszterda Monika , Frańska Magdalena , Frański Rafał
Published: March 2021

Biodegradation of bisphenol A in the environmental waters (lake, river, and sea) has been studied on the base of fortification of the samples taken and the biodegradation products have been analyzed using HPLC/UV/ESI-MS. Analysis of the characteristic fragmentation patterns of [M-H]− ions permitted unambiguous identification of the biodegradation products as 2,2-bis(4-hydroxyphenyl)-1-propanol or as p-hydroxyacetophenone, depending on the type of surface water source. The formation of 2,2-bis(4-hydroxyphenyl)-1-propanol was much more common than that of p-hydroxyacetophenone. Moreover, 2,2-Bis(4-hydroxyphenyl)-1-propanol has not been further biodegraded, in contrast to the p-hydroxyacetophenone, which was further mineralized. It has been proved, for the first time, that 2,2-bis(4-hydroxyphenyl)-1-propanol can be regarded as persistent product of bisphenol A biodegradation in the fortified environmental waters.
Natural Co-Occurrence of Multiple Mycotoxins in Unprocessed Oats Grown in Ireland with Various Production Systems
Authors: De Colli Lorenzo , De Ruyck Karl , Abdallah Mohamed F. , Finnan John , Mullins Ewen , Kildea Steven , Spink John , Elliott Christopher , Danaher Martin
Published: March 2021

The natural co-occurrence of 42 mycotoxins was investigated in unprocessed oat grains grown in Ireland. The sample set included a total of 208 oat crops harvested during 2015–2016 and produced using conventional, organic, or gluten free farming systems. A range of different toxins was identified, including the major type A (neosolaniol, HT-2 and T-2 toxins, T-2 triol, and T-2-glucoside, co-occurring in 21 samples) and B trichothecenes (deoxynivalenol, nivalenol, and deoxynivalenol-3-glucoside), enniatins (B1, B, and A1, co-occurring in 12 samples), as well as beauvericin, alternariol, mycophenolic acid, and sterigmatocystin. The influences of sowing season, year, and production system were investigated, eventually indicating that the latter factor may have a higher impact than others on the production of certain mycotoxins in oats. The most frequently quantified compounds were HT-2 (51%) and T-2 (41%) toxins, with gluten free oats containing significantly lower concentrations of HT-2 compared to conventionally produced oats. Although the prevalence and concentrations of mycotoxin found in oat samples in this study should be substantially reduced by processing. However, as mycotoxin occurrence is clearly influenced by multiple factors, controlled field trials should be carried out to define optimal agronomic practices and mitigate mycotoxin production. Furthermore, this work highlights the need for regularly testing cereal-based foods with multi-residue analytical methods with wider specificities than the traditionally screened and regulated toxins, to generate knowledge on the occurrence of several mycotoxins that are, to date, rarely investigated.
Inferior Education or Killing Grandma: The Dilemma Facing the Public School Systems in the United States
Authors: Bodin Lawrence , Frieman Barry
Published: March 2021

Due to COVID-19, school districts in the fall of 2020 had to decide whether to conduct all classes in person or offer some or all of these classes virtually. Many school districts would decide on a program and then change their decision based on the COVID-19 situation in their area. These changes caused education and personal issues for the students, teachers, parents, and others who worked in their school system. This paper explores how the Analytic Hierarchy Process (AHP), a well-regarded, multi-criteria decision analysis approach, can be used to analyze this situation by developing two prototype versions of the AHP and illustrating these versions of the AHP with a detailed example. The team approach for analyzing this issue is also described. Additionally, the current situation of this problem in the United States and elsewhere is discussed. Finally, Professor Bodin is making software that he has developed available (at no cost) for carrying out many of the computations for the AHP versions described in this paper.
Target Product Profile Analysis of COVID-19 Vaccines in Phase III Clinical Trials and Beyond: An Early 2021 Perspective
Authors: Funk Colin D. , Laferrière Craig , Ardakani Ali
Published: March 2021

The coronavirus SARS-CoV-2, which causes Coronavirus disease 2019 (COVID-19), has infected more than 100 million people globally and caused over 2.5 million deaths in just over one year since its discovery in Wuhan, China in December 2019. The pandemic has evoked widespread collateral damage to societies and economies, and has destabilized mental health and well-being. Early in 2020, unprecedented efforts went into the development of vaccines that generate effective antibodies to the SARS-CoV-2 virus. Teams developing twelve candidate vaccines, based on four platforms (messenger RNA, non-replicating viral vector, protein/virus-like particle, and inactivated virus) had initiated or announced the Phase III clinical trial stage by early November 2020, with several having received emergency use authorization in less than a year. Vaccine rollout has proceeded around the globe. Previously, we and others had proposed a target product profile (TPP) for ideal/optimal and acceptable/minimal COVID-19 vaccines. How well do these candidate vaccines stack up to a harmonized TPP? Here, we perform a comparative analysis in several categories of these candidate vaccines based on the latest available trial data and highlight the early successes as well as the hurdles and barriers yet to be overcome for ending the global COVID-19 pandemic.
Genetic Variation in the Domain II, 3′ Untranslated Region of Human and Mosquito Derived Dengue Virus Strains in Sri Lanka
Authors: Dayananda P. D. , de Silva Harendra , Fernando LakKumar , de Silva B. G. D. N. K.
Published: March 2021

Genetic variations in dengue virus (DENV) play a distinct role in epidemic emergence. The DENV 3′ UTR has become a recent interest in research. The objective of the study was to examine the genetic variation in the domain II, 3′ UTR region of human and mosquito-derived DENV. DENV-infected human sera were orally infected to laboratory reared Aedes aegypti mosquitoes. The domain II, 3′ UTR of each human- and mosquito-derived sample was amplified. The nucleotide sequence variation, phylogenetic and secondary structure analysis was carried out incorporating respective regions of so far recorded Sri Lankan and the reference genotype strains of the DENV3 and DENV1 serotypes. The human- and mosquito-derived domain II, 3′ UTR were identical in nucleotide sequences within the serotypes isolated, indicating the conserved nature of the region during host switch. The sequence analysis revealed distinct variations in study isolates compared to so far recorded Sri Lankan isolates. However, despite single nucleotide variations, the maintenance of structural integrity was evident in related strains within the serotypes in the secondary structure analysis. The phylogenetic analysis revealed distinct clade segregation of the study sequences from so far reported Sri Lankan isolates and illustrated the phylogenetic relations of the study sequences to the available global isolates of respective serotypes.
COVID-19 Vaccine Failure in a Patient with Multiple Sclerosis on Ocrelizumab
Authors: Chilimuri Sridhar , Mantri Nikhitha , Gongati Sudharsan , Zahid Maleeha , Sun Haozhe
Published: March 2021

Vaccines will play a key role in ending the COVID-19 pandemic. Vaccination against infections remains an important part of the management of patients with multiple sclerosis. However, there are limited data about the safety and efficacy of the currently available COVID-19 mRNA vaccines in patients with multiple sclerosis receiving concurrent immunosuppressive therapies. Patients on B cell depleting therapy such as ocrelizumab have an attenuated vaccine response. We report the first case of COVID-19 vaccine failure in a patient with relapsing-remitting multiple sclerosis on B cell depleting therapy, ocrelizumab. We offer suggestions to improve vaccine efficacy in these patients.
VLP-Based Vaccines as a Suitable Technology to Target Trypanosomatid Diseases
Authors: Queiroz Aline Maria Vasconcelos , Oliveira Johny Wysllas de Freitas , Moreno Cláudia Jassica , Guérin Diego M. A. , Silva Marcelo Sousa
Published: March 2021

Research on vaccines against trypanosomatids, a family of protozoa that cause neglected tropical diseases, such as Chagas disease, leishmaniasis, and sleeping sickness, is a current need. Today, according to modern vaccinology, virus-like particle (VLP) technology is involved in many vaccines, including those undergoing studies related to COVID-19. The potential use of VLPs as vaccine adjuvants opens an opportunity for the use of protozoan antigens for the development of vaccines against diseases caused by Trypanosoma cruzi, Leishmania spp., and Trypanosoma brucei. In this context, it is important to consider the evasion mechanisms of these protozoa in the host and the antigens involved in the mechanisms of the parasite–host interaction. Thus, the immunostimulatory properties of VLPs can be part of an important strategy for the development and evaluation of new vaccines. This work aims to highlight the potential of VLPs as vaccine adjuvants for the development of immunity in complex diseases, specifically in the context of tropical diseases caused by trypanosomatids.
Reduced Efficacy of Fenbendazole and Pyrantel Pamoate Treatments against Intestinal Nematodes of Stud and Performance Horses
Authors: Zanet Stefania , Battisti Elena , Labate Federico , Oberto Francesca , Ferroglio Ezio
Published: March 2021

Nematodes are an important cause of disease and loss of performance in horses. Changes in the parasitic fauna of horses have occurred in the past few decades, making cyathostomins the major parasites in adult horses, while large strongyles have become less prevalent. Parascaris spp. remains the most important parasite infecting foals and weanlings. Anthelmintic resistance is highly prevalent in cyathostomins and Parascaris spp. worldwide and it must be factored into treatment decisions. To assess anthelmintic efficacy in Northern Italy, we sampled 215 horses from 17 sport and horse-breeding farms. Fecal egg count reduction tests (FECRT) were used to assess anthelmintic efficacy. Copromicroscopic analysis was performed using MiniFLOTAC before treatment with fenbendazole, pyrantel pamoate or ivermectin, and repeated 14 days post-treatment. Strongyle-type eggs were detected in 66.91% of horses (CI95% 61.40–73.79%), while Parascaris spp. was detected in 2.79% (CI95% 1.94–5.95%). Reduced efficacy against cyathostomins was observed for fenbendazole in 55.56% of the treated animals (CI95% 41.18–69.06%), and for pyrantel pamoate in 75% of animals (CI95% 30.06–95.44%). Ground-based actions must be set in place to promote the uptake of state-of-the-art worm control plans that will prevent clinical disease while minimizing the selection pressure of resistant parasites.
A Novel Physically Based Distributed Model for Irrigation Districts’ Water Movement
Authors: Mi Boyu , Chen Haorui , Wang Shaoli , Jin Yinlong , Jia Jiangdong , Chang Xiaomin , Fu Xiaojun , Chai Ronghua , Wei Meiling
Published: March 2021

The water movement research in irrigation districts is important for food production. Many hydrological models have been proposed to simulate the water movement on the regional scale, yet few of them have comprehensively considered processes in the irrigation districts. A novel physically based distributed model, the Irrigation Districts Model (IDM), was constructed in this study to address this problem. The model combined the 1D canal and ditch flow, the 1D soil water movement, the 2D groundwater movement, and the water interactions among these processes. It was calibrated and verified with two-year experimental data from Shahaoqu Sub-Irrigation Area in Hetao Irrigation District. The overall water balance error is 2.9% and 1.6% for the two years, respectively. The Nash–Sutcliffe efficiency coefficient (NSE) of water table depth and soil water content is 0.72 and 0.64 in the calibration year and 0.68 and 0.64 in the verification year. The results show good correspondence between the simulation and observation. It is practicable to apply the model in water movement research of irrigation districts.
An Experimental Study on the Sources of Strontium in Mineral Water and General Rules of Its Dissolution—A Case Study of Chengde, Hebei
Authors: Wang Ruifeng , Wu Xiong , Zhai Yanliang , Su Yuxuan , Liu Chenhui
Published: March 2021

Chengde City boasts a wealth of high-quality mineral water resources characterized by a high level of strontium (Sr), a low level of sodium, and low alkalinity. In order to study the mechanism of formation of Sr-bearing mineral water in Chengde and to scientifically guide future mineral water exploration, taking three typical mineral water exploration areas in Chengde as examples, this paper studies the sources of Sr in mineral water and the general rules of its dissolution via a laboratory static leaching experiment and impact experiments, and it provides an analysis of the characteristics of typical rock samples. The research results indicate that the content of Sr in surrounding rock and the characteristics of minerals existing in surrounding rock jointly control the dissolution of Sr in water; that CO2 can promote the formation of mineral water containing Sr; and that temperature increases may boost the dissolution of Sr from carbonate minerals but also inhibit the dissolution of Sr from silicate minerals.
Short-Term Response of Chlorophyll a Concentration Due to Intense Wind and Freshwater Peak Episodes in Estuaries: The Case of Fangar Bay (Ebro Delta)
Authors: F-Pedrera Balsells Marta , Grifoll Manel , Fernández-Tejedor Margarita , Espino Manuel
Published: March 2021

Estuaries and coastal bays are areas of large spatio-temporal variability in physical and biological variables due to environmental factors such as local wind, light availability, freshwater inputs or tides. This study focuses on the effect of strong wind events and freshwater peaks on short-term chlorophyll a (Chl a) concentration distribution in the small-scale and microtidal, Fangar Bay (Ebro Delta, northwestern Mediterranean). The hydrodynamics of this bay are primarily driven by local wind episodes modulated by stratification in the water column. Results based on field-campaign observations and Sentinel-2 images revealed that intense wind episodes from both NW (offshore) and NE-E (onshore) caused an increase in the concentration of surface Chl a. The mechanisms responsible were horizontal mixing and the bottom resuspension (also linked to the breakage of the stratification) that presumably resuspended Chl a containing biomass (i.e., micropyhtobentos) and/or incorporated nutrients into the water column. On the other hand, sea-breeze was not capable of breaking up the stratification, so the chlorophyll a concentration did not change significantly during these episodes. It was concluded that the mixing produced by the strong winds favoured an accumulation of Chl a concentration, while the stratification that causes a positive estuarine circulation reduced this accumulation. However, the spatial-temporal variability of the Chl a concentration in small-scale estuaries and coastal bays is quite complex due to the many factors involved and deserve further intensive field campaigns and additional numerical modelling efforts.
Ontogenetic Structure and Temporal Patterns of Summer Ichthyoplankton in Upper Course of the Xijiang River, SW China
Authors: Gao Minghui , Wu Zhiqiang , Tan Xichang , Huang Liangliang , Feng Jie , Rad Saeed
Published: March 2021

The summer ichthyoplankton characteristics in the Laibin section of the Xijiang River were analyzed based on a survey during summer 2017. The ontogenetic structure and temporal patterns of ichthyoplankton and the correlation between environmental parameters and the temporal patterns were investigated. A total of 10,665 eggs and 447 larval belonging to four orders, ten families, and 28 species were collected. According to the flood regime, summer is divided into three periods (pre-flood, flood period, and post-flood). Ichthyoplankton proved to be heterogeneous between periods in summer with differences in the composition and abundance. The assemblages were distinguished by multiple analytical tools, and presented a chronological pattern of marked variability in composition of the species between the periods, and under the strong influence of flood. The assemblages were mainly represented by eggs of S. wui Fang and S. robusta in the pre-flood period, S. argentatus and S. macrops in the flood period, and H. leucisculus and S. curriculus in the post-flood period, while, the larval occurred mainly in the flood period. Understanding these temporal patterns of the upper course of the Xijiang River is useful for the recruitment of fish resources and conservation of fish community diversity.
Saturated Hydraulic Conductivity Estimation Using Artificial Neural Networks
Authors: Trejo-Alonso Josué , Fuentes Carlos , Chávez Carlos , Quevedo Antonio , Gutierrez-Lopez Alfonso , González-Correa Brandon
Published: March 2021

In the present work, we construct several artificial neural networks (varying the input data) to calculate the saturated hydraulic conductivity (KS) using a database with 900 measured samples obtained from the Irrigation District 023, in San Juan del Rio, Queretaro, Mexico. All of them were constructed using two hidden layers, a back-propagation algorithm for the learning process, and a logistic function as a nonlinear transfer function. In order to explore different arrays for neurons into hidden layers, we performed the bootstrap technique for each neural network and selected the one with the least Root Mean Square Error (RMSE) value. We also compared these results with pedotransfer functions and another neural networks from the literature. The results show that our artificial neural networks obtained from 0.0459 to 0.0413 in the RMSE measurement, and 0.9725 to 0.9780 for R2, which are in good agreement with other works. We also found that reducing the amount of the input data offered us better results.
Water-Sediment Physicochemical Dynamics in a Large Reservoir in the Mediterranean Region under Multiple Stressors
Authors: Palma Patrícia , Penha Alexandra , Novais Maria , Fialho Sofia , Lima Ana , Mourinha Clarisse , Alvarenga Paula , Rosado Anabela , Iakunin Maksim , Rodrigues Gonçalo , Potes Miguel , Costa Maria , Morais Manuela , Salgado Rui
Published: March 2021

Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy.
Numerical Study on the Hydraulic Properties of Flow over Different Pooled Stepped Spillways
Authors: Ghaderi Amir , Abbasi Saeed , Di Francesco Silvia
Published: March 2021

This work presents numerical simulations carried out to study the influence of geometric characteristics of pooled steps on the energy dissipation performance, flow patterns properties, velocity rates, and pressure distributions over a spillway. The localization of the inception point of air entrainment was also assessed, being a key design parameter of spillways. With this aim, different configurations of steps were taken in account, including flat, pooled, and notch pooled types. The computational procedure was first validated with experimental results from the literature and then used to test the hydraulic behavior derived from different geometric configurations. The flat step configuration showed the best energy dissipation performance as compared with other configurations. With the notched pooled step configuration, the efficiency performance of the pooled structure improved by about 5.8%. The interfacial velocities of the flat stepped spillway were smaller than those of the pooled structure. The pressure value at the beginning of the step in the pooled configuration was larger than the flat configuration, while for the notched pool the maximum pressure values decreased near the step pool. Pool configuration (simple or notched) did not have a significant influence on the location of air entrainment.