bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Potential Habitat Changes of Two Invasive Alien Fish Species with Climate Change at a Regional Scale
Authors: Hong Seungbum , Jang Inyoung , Kim Daegeun , Kim Suhwan , Park Hyun Su , Lee Kyungeun
Published: May 2022

Developing national-level policies related to climate change induced expansions of invasive species requires predictive modelling at a regional scale level. This study aimed to predict future changes in the habitat distributions of two major invasive alien fish species, Micropterus salmoides and Lepomis macrochirus, in South Korea. An ensemble system with multiple species distribution models was used for the prediction, and gridded water portion data from the linear-structure information on river channels inputted as habitat characteristics of freshwater ecosystem into the models. Bioclimatic variables at 20-year intervals from 2001 to 2100 were generated from predicted temperature and precipitation data under the representative concentration pathway 4.5 and 8.5 scenarios. The overall distribution probabilities of the potential habitats increased with time in both climate change scenarios, and the potential habitats were predicted to expand to upstream areas. Combined with regional ecological value information, such as biodiversity in freshwater ecosystems, these results can be an important basis for deriving regional priority information for managing alien species in climate change. Additionally, the modelling approach is highly applicable to various national-level policies for ecosystem conservation since it is not greatly restricted by spatial scales.
A Structural Characterisation of the Mitogen-Activated Protein Kinase Network in Cancer
Authors: Chatzaroulas Evangelos , Sliogeris Vytenis , Victori Pedro , Buffa Francesca M. , Moschoyiannis Sotiris , Bauer Roman
Published: May 2022

Gene regulatory networks represent collections of regulators that interact with each other and with other molecules to govern gene expression. Biological signalling networks model how signals are transmitted and how activities are coordinated in the cell. The study of the structure of such networks in complex diseases such as cancer can provide insights into how they function, and consequently, suggest suitable treatment approaches. Here, we explored such topological characteristics in the example of a mitogen-activated protein kinase (MAPK) signalling network derived from published studies in cancer. We employed well-established techniques to conduct network analyses, and collected information on gene function as obtained from large-scale public databases. This allowed us to map topological and functional relationships, and build hypotheses on this network’s functional consequences. In particular, we find that the topology of this MAPK network is highly non-random, modular and robust. Moreover, analysis of the network’s structure indicates the presence of organisational features of cancer hallmarks, expressed in an asymmetrical manner across communities of the network. Finally, our results indicate that the organisation of this network renders it problematic to use treatment approaches that focus on a single target. Our analysis suggests that multi-target attacks in a well-orchestrated manner are required to alter how the network functions. Overall, we propose that complex network analyses combined with pharmacological insights will help inform on future treatment strategies, exploiting structural vulnerabilities of signalling and regulatory networks in cancer.
A Multi-Strategy Improved Arithmetic Optimization Algorithm
Authors: Liu Zhilei , Li Mingying , Pang Guibing , Song Hongxiang , Yu Qi , Zhang Hui
Published: May 2022

To improve the performance of the arithmetic optimization algorithm (AOA) and solve problems in the AOA, a novel improved AOA using a multi-strategy approach is proposed. Firstly, circle chaotic mapping is used to increase the diversity of the population. Secondly, a math optimizer accelerated (MOA) function optimized by means of a composite cycloid is proposed to improve the convergence speed of the algorithm. Meanwhile, the symmetry of the composite cycloid is used to balance the global search ability in the early and late iterations. Thirdly, an optimal mutation strategy combining the sparrow elite mutation approach and Cauchy disturbances is used to increase the ability of individuals to jump out of the local optimal. The Rastrigin function is selected as the reference test function to analyze the effectiveness of the improved strategy. Twenty benchmark test functions, algorithm time complexity, the Wilcoxon rank-sum test, and the CEC2019 test set are selected to test the overall performance of the improved algorithm, and the results are then compared with those of other algorithms. The test results show that the improved algorithm has obvious advantages in terms of both its global search ability and convergence speed. Finally, the improved algorithm is applied to an engineering example to further verify its practicability.
Optimal Topology Design for Distributed Generation Networks Considering Different Nodal Invulnerability Requirements
Authors: Jiao Peng , Huang Shengjun , Jiang Bo , Zhang Tao
Published: May 2022

Distributed generators and microgrids are of great importance for the stable operation of power systems when failures occur. The major work of this paper is proposing an optimal topological design model of preset connection lines, aiming at a distributed power generation network based on different nodal invulnerability requirements. Moreover, the important innovation of this paper lies in that the perspective is shifted from the system to an individual node of a different type. When a node malfunction occurs, the faulty node can be connected to its neighbor nodes by closing a switch to achieve energy exchange. The distributed generation network consists of a series of nodes that can realize self-sufficiency and can be classified into three types with different levels of importance according to their tasks. The nodes of different types must meet different requirements of destructibility. In this paper, a mixed-integer linear programming model is formulated to solve the optimal topology design problem. In addition, this paper also analyzes the influence of changing nodal power generation capacity and nodal type, and the simulation results show the practicability of the proposal.
Sex-Related Left-Lateralized Development of the Crus II Region of the Ansiform Lobule in Cynomolgus Monkeys
Authors: Sawada Kazuhiko , Saito Shigeyoshi
Published: May 2022

The asymmetric development of the cerebellum has been reported in several mammalian species. The current study quantitatively characterized cerebellar asymmetry and sexual dimorphism in cynomolgus macaques using magnetic resonance (MR) imaging-based volumetry. Three-dimensional T1W MR images at 7-tesla were acquired ex vivo from fixed adult male (n = 5) and female (n = 5) monkey brains. Five transverse domains of the cerebellar cortex, known as cerebellar compartmentation defined by the zebrin II/aldolase expression pattern, were segmented on MR images, and the left and right sides of their volumes were calculated. Asymmetry quotient (AQ) analysis revealed significant left-lateralization at the population level in the central zone posterior to the cerebellar transverse domains, which included lobule VII of the vermis with the crura I and II of ansiform lobules, in males but not females. Next, the volume of the cerebellar hemispherical lobules was calculated. Population-level leftward asymmetry was revealed in the crus II regions in males using AQ analysis. The AQ values of the other hemispherical lobules showed no left/right side differences at the population level in either sex. The present findings suggest a sexually dimorphic asymmetric aspect of the cerebellum in cynomolgus macaques, characterized by a leftward lateralization of the crus II region in males, but no left/right bias in females.
Optimal Energy Efficiency Used DDPG in IRS-NOMA Wireless Communications
Authors: Liu Quanjin , Wu Jianlan , Hu Langtao , Bi Songjiao , Ji Wen , Yang Rui
Published: May 2022

Combining Intelligent Reflecting Surface (IRS) with Non-Orthogonal Multiple Access (NOMA) technology is a viable option for increasing communication performance. Firstly, a NOMA downlink transmission system assisted by IRS is established in this study, for maximizing its energy efficiency. Then a Deep Deterministic Policy Gradient (DDPG) algorithm with symmetric properties is used to further optimize the energy efficiency of the system by intelligently adjusting the beam-forming matrix of the access point (AP) and the phase-shift matrix of the IRS. According to the simulation results, the proposed IRS-assisted NOMA downlink network based on the DDPG algorithm presented a considerably higher energy efficiency than the orthogonal multiple access network.
New Versions of Locating Indices and Their Significance in Predicting the Physicochemical Properties of Benzenoid Hydrocarbons
Authors: Wazzan Suha , Saleh Anwar
Published: May 2022

In this paper, we introduce some new versions based on the locating vectors named locating indices. In particular, Hyper locating indices, Randić locating index, and Sambor locating index. The exact formulae for these indices of some well-known families of graphs and for the Helm graph are derived. Moreover, we determine the importance of these locating indices for 11 benzenoid hydrocarbons. Furthermore, we show that these new versions of locating indices have a reasonable correlation using linear regression with physicochemical characteristics such as molar entropy, acentric factor, boiling point, complexity, octanol–water partition coefficient, and Kovats retention index. The cases in which good correlations were obtained suggested the validity of the calculated topological indices to be further used to predict the physicochemical properties of much more complicated chemical compounds.
Consistent Deformations for a Non-Standard D = 6 Topological BF Model from a BRST-Symmetry-Based Cohomological Approach
Authors: Saliu Solange-Odile , Cioroianu Eugen-Mihăiţă , Bizdadea Constantin
Published: May 2022

This paper falls under the heading of constructing consistent self-couplings in topological BF models. Our endeavor is of interest in the context of pure gravity, General Relativity, and super-gravity in Ashtekar formalism, which allow for certain economic formulations in terms of self-coupled BF theories in the presence of certain extra-constraints. More precisely, herein we address the construction of a special class of D=6 self-interactions for a collection of topological BF models with a non-standard field spectrum. Our methodology relies on a deformation method based on the relationship between antifield–BRST symmetry and the non-trivial gauge symmetries of a given field theory and implemented via the computation of certain precise spaces of the local BRST cohomology corresponding to the free limit. This cohomological BRST approach is applied to the starting free model under standard “selection rules” from Quantum Field Theory. Our findings are completely new and reveal a self-interacting topological BF model in D=6 with a complex gauge structure that is entirely read from the expression of the fully deformed solution to the classical master equation (the canonical generator of the antifield–BRST symmetry), and includes a generalization of the famous D=2 gravity in BF formulation.
Toxic Metals in a Paddy Field System: A Review
Authors: Duan Yuanliang , Li Qiang , Zhang Lu , Huang Zhipeng , Zhao Zhongmeng , Zhao Han , Du Jun , Zhou Jian
Published: May 2022

The threat of toxic metals to food security and human health has become a high-priority issue in recent decades. As the world’s main food crop source, the safe cultivation of rice has been the focus of much research, particularly the restoration of toxic metals in paddy fields. Therefore, in this paper, we focus on the effects of toxic metals on rice, as well as the removal or repair methods of toxic metals in paddy fields. We also provide a detailed discussion of the sources and monitoring methods of toxic metals pollution, the current toxic metal removal, and remediation methods in paddy fields. Finally, several important research issues related to toxic metals in paddy field systems are proposed for future work. The review has an important guiding role for the future of heavy metal remediation in paddy fields, safe production of rice, green ecological fish culture, and human food security and health.
Diagnosing Human Fascioliasis Using ELISA Immunoassays at a Tertiary Referral Hospital in Hanoi: A Cross-Sectional Study
Authors: Nguyen Thu Huong , Dermauw Veronique , Tran Huy Tho , Roucher Clémentine , Dorny Pierre , Nguyen Thi Hoai , Trung Kien Hoang , Dao Van Thang , Do Nhu Binh , Nguyen Kim Thu
Published: May 2022

Infections with the zoonotic liver flukes Fasciola gigantica and Fasciola hepatica may result in severe disease in humans. In Vietnam, an emergence of fascioliasis cases has been observed from the late 1990s onwards. Various diagnostic tools are used in the country, but the agreement between these tools has not been critically evaluated. We aimed to describe the clinical presentation and diagnostic outcomes in fascioliasis patients in Vietnam. A retrospective, cross-sectional study was conducted on the medical records of a group of 145 patients diagnosed with fascioliasis at a tertiary referral hospital in Hanoi. Based on the review, sociodemographic background and clinical presentation were recorded. These patients all received standard routine serologic tests, including internal antibody (Ab)-ELISA, an enzyme-linked immunosorbent assay (ELISA), and commercial coproantigen (cAg)-ELISA. The majority of cases were between 30 and 59 years old (68.3%), and about half of them were male (51.0%). Upper quadrant and epigastric pain were the most commonly reported symptoms (61.4% and 35.2%, respectively). All but one patient had liver lesions upon ultrasound examination (99.3%), and eosinophilia was present in most of the patients (89.7%). A high number of patients were positive in the in-house and the commercial Ab-ELISA (95.9% and 87.4%, respectively), yet only a slight agreement was observed between the two tests (kappa coefficient, 0.06). A further 47.4% of cases were positive for the commercial cAg-ELISA, whereas stool microscopy indicated the presence of Fasciola spp. eggs in 25.7% of patients. The current study emphasizes the challenges related to the diagnosis of human fascioliasis in Vietnam.
Convolutional Neural Networks Based on Sequential Spike Predict the High Human Adaptation of SARS-CoV-2 Omicron Variants
Authors: Nan Bei-Guang , Zhang Sen , Li Yu-Chang , Kang Xiao-Ping , Chen Yue-Hong , Li Lin , Jiang Tao , Li Jing
Published: May 2022

The COVID-19 pandemic has frequently produced more highly transmissible SARS-CoV-2 variants, such as Omicron, which has produced sublineages. It is a challenge to tell apart high-risk Omicron sublineages and other lineages of SARS-CoV-2 variants. We aimed to build a fine-grained deep learning (DL) model to assess SARS-CoV-2 transmissibility, updating our former coarse-grained model, with the training/validating data of early-stage SARS-CoV-2 variants and based on sequential Spike samples. Sequential amino acid (AA) frequency was decomposed into serially and slidingly windowed fragments in Spike. Unsupervised machine learning approaches were performed to observe the distribution in sequential AA frequency and then a supervised Convolutional Neural Network (CNN) was built with three adaptation labels to predict the human adaptation of Omicron variants in sublineages. Results indicated clear inter-lineage separation and intra-lineage clustering for SARS-CoV-2 variants in the decomposed sequential AAs. Accurate classification by the predictor was validated for the variants with different adaptations. Higher adaptation for the BA.2 sublineage and middle-level adaptation for the BA.1/BA.1.1 sublineages were predicted for Omicron variants. Summarily, the Omicron BA.2 sublineage is more adaptive than BA.1/BA.1.1 and has spread more rapidly, particularly in Europe. The fine-grained adaptation DL model works well for the timely assessment of the transmissibility of SARS-CoV-2 variants, facilitating the control of emerging SARS-CoV-2 variants.
Host Responses Following Infection with Canadian-Origin Wildtype and Vaccine Revertant Infectious Laryngotracheitis Virus
Authors: Elshafiee Esraa A. , Isham Ishara M. , Najimudeen Shahnas M. , Perez-Contreras Ana , Barboza-Solis Catalina , Ravi Madhu , Abdul-Careem Mohamed Faizal
Published: May 2022

Infectious laryngotracheitis (ILT) is caused by Gallid herpesvirus-1 (GaHV-1) or infectious laryngotracheitis virus (ILTV) and was first described in Canadian poultry flocks. In Canada, ILTV infection is endemic in backyard flocks, and commercial poultry encounters ILT outbreaks sporadically. A common practice to control ILT is the use of live attenuated vaccines. However, outbreaks still occur in poultry flocks globally due to ILTV vaccine strains reverting to virulence and emergence of new ILTV strains due to recombination in addition to circulating wildtype strains. Recent studies reported that most of the ILT outbreaks in Canada were induced by the chicken-embryo-origin (CEO) live attenuated vaccine revertant strains with the involvement of a small percentage of wildtype ILTV. It is not known if the host responses induced by these two ILTV strains are different. The objective of the study was to compare the host responses elicited by CEO revertant and wildtype ILTV strains in chickens. We infected 3-week-old specific pathogen-free chickens with the two types of ILTV isolates and subsequently evaluated the severity of clinical and pathological manifestations, in addition to host responses. We observed that both of the isolates show high pathogenicity by inducing several clinical and pathological manifestations. A significant recruitment of immune cells at both 3 and 7 days post-infection (dpi) was observed in the tracheal mucosa and the lung tissues of the infected chickens with wildtype and CEO vaccine revertant ILTV isolates when compared to uninfected controls. Overall, this study provides a better understanding of the mechanism of host responses against ILTV infection.
Probable Vogt–Koyanagi–Harada Disease after COVID-19 Vaccination: Case Report and Literature Review
Authors: Ding Xinyi , Chang Qing
Published: May 2022

COVID-19 vaccination is considered the most effective and promising approach for the elimination of the SARS-CoV-2 pandemic globally. Although the vaccine has been proven to be safe, as evidenced by the promotion of mass vaccination, new side effects, including several ocular complications that were not described during the experimental stage, are now emerging. In the present study, we report a 33-year-old Chinese man who developed probable Vogt–Koyanagi–Harada (VKH) disease only one day after his first dose of an inactivated COVID-19 vaccine, without any systemic symptoms. His medical history was unremarkable, except for hypertension. Although successfully relieved by oral prednisone, the patient progressed to the chronic stage of VKH disease with ocular depigmentation 4 months after onset. By reviewing similar cases previously reported, we discuss and summarize the common characteristics of VKH disease associated with vaccines against SARS-CoV-2, as well as the possible mechanisms behind this phenomenon. Although the causality is unclear, ophthalmologists and generalists should be aware of this possible ocular adverse effect after COVID-19 vaccination.
Influence of a Heterologous (ChAdOx1-nCoV-19/BNT162b2) or Homologous (BNT162b2/BNT162b2) Vaccination Regimen on the Antibody and T Cell Response to a Third Vaccination with BNT162b2
Authors: Reiter Rieke , Von Blanckenburg Pia , Mutters Reinier , Thiemer Julia , Geßner Reinhard , Seifart Ulf
Published: May 2022

Emerging numbers of SARS-CoV-2 infections are currently combated with a third vaccination. Considering the different vaccination regimens used for the first two vaccine doses, we addressed whether the previous vaccination influences the immune response to the booster. Participants for this prospective study were recruited from among healthcare workers. N = 20 participants were previously vaccinated with two doses of BNT162b2, and n = 53 received a priming dose of ChAdOx1-nCoV-19 followed by a BNT162b2 dose. Participants were vaccinated with a third dose of BNT162b2 in December 2021. Antibody concentrations were determined after vaccination, and in a subset of n = 19 participants, T cell responses were evaluated. Anti-S concentrations and IFNγ production increased during the first 21 days. The choice of the first and second vaccineshad no influence on the final outcome of the booster vaccination. Before booster vaccination, antibody concentrations were lower for older participants but increased more strongly over time.
Targeting Membrane Trafficking as a Strategy for Cancer Treatment
Authors: Tejeda-Muñoz Nydia , Mei Kuo-Ching , Sheladiya Pooja , Monka Julia
Published: May 2022

Membrane trafficking is emerging as an attractive therapeutic strategy for cancer. Recent reports have found a connection between Wnt signaling, receptor-mediated endocytosis, V-ATPase, lysosomal activity, and macropinocytosis through the canonical Wnt pathway. In macropinocytic cells, a massive internalization of the plasma membrane can lead to the loss of cell-surface cadherins, integrins, and other antigens that mediate cell–cell adhesion, favoring an invasive phenotype. V-ATPase is a key regulator in maintaining proper membrane trafficking, homeostasis, and the earliest developmental decisions in the Xenopus vertebrate development model system. Here, we review how the interference of membrane trafficking with membrane trafficking inhibitors might be clinically relevant in humans.
Impact of Pneumococcal Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae and Microbiota Profiles in Preschool Children in South East Poland
Authors: Kielbik Karolina , Pietras Aleksandra , Jablonska Joanna , Bakiera Adrian , Borek Anna , Niedzielska Grazyna , Grzegorczyk Michal , Grywalska Ewelina , Korona-Glowniak Izabela
Published: May 2022

In 2017, Poland introduced the 10-valent pneumococcal conjugate vaccine (PCV) into its national immunization schedule. This prospective study was conducted between March and June 2020 to determine the impact of vaccination on prevalence of the nasopharyngeal carriage of S. pneumoniae in 176 healthy children and to determine how conjugate vaccines indirectly affect colonization of nasopharyngeal microbiota. Pneumococcal isolates were analyzed by serotyping and antimicrobial resistance tests. Nasopharyngeal microbiota were detected and identified using the culture method and real-time PCR amplification primers and hydrolysis-probe detection with the 16S rRNA gene as the target. In the vaccinated group of children, colonization was in 24.2% of children, compared to 21.4% in the unvaccinated group. Serotypes 23A and 23B constituted 41.5% of the isolates. Serotypes belonging to PCV10 and PCV13 constituted 4.9% and 17.1% of the isolates, respectively. S. pneumoniae isolates were resistant to penicillin (34.1%), erythromycin (31.7%), and co-trimoxazole (26.8%). Microbial DNA qPCR array correlated to increased amounts of Streptococcus mitis and S. sanguinis in vaccinated children, with reduced amounts of C. pseudodiphtericum, S. aureus, and M. catarrhalis. Introduction of PCV for routine infant immunization was associated with significant reductions in nasopharyngeal carriage of PCV serotypes and resistant strains amongst vaccine serotypes, yet carriage of non-PCV serotypes increased modestly, particularly serotype 23B.
The Global Impact of Hepatitis B Vaccination on Hepatocellular Carcinoma
Authors: Flores Joan Ericka , Thompson Alexander J. , Ryan Marno , Howell Jessica
Published: May 2022

Over 1.5 million preventable new hepatitis B infections continue to occur each year and there are an estimated 296 million people living with chronic hepatitis B infection worldwide, resulting in more than 820,000 deaths annually due to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B vaccination remains the cornerstone of public health policy to prevent HCC and a vital component of the global hepatitis B elimination response. The WHO has set a 90% vaccination target to achieve hepatitis B elimination by 2030; however, there is wide variability in reported birth dose coverage, with global coverage at only 42%. In this review, we outline the global trends in hepatitis B vaccination coverage and the impact of hepatitis B vaccination on HCC incidence and discuss the challenges and enabling factors for achieving WHO 2030 hepatitis B vaccination coverage targets.
Dextran Sulphate Sodium Acute Colitis Rat Model: A Suitable Tool for Advancing Our Understanding of Immune and Microbial Mechanisms in the Pathogenesis of Inflammatory Bowel Disease
Authors: Adamkova Petra , Hradicka Petra , Kupcova Skalnikova Helena , Cizkova Veronika , Vodicka Petr , Farkasova Iannaccone Silvia , Kassayova Monika , Gancarcikova Sona , Demeckova Vlasta
Published: May 2022

Inflammatory bowel disease (IBD) is a group of disorders causing inflammation in the digestive tract. Recent data suggest that dysbiosis may play a pivotal role in the IBD pathogenesis. As microbiome-based therapeutics that modulate the gut ecology have been proposed as a novel strategy for preventing IBD, the aim of presenting study was to evaluate the dextran sulphate sodium (DSS) rat model mainly in terms of microbial shifts to confirm its suitability for dysbiosis study in IBD. Acute colitis was induced using 5% DSS solution for seven days and rats were euthanized five days after DSS removal. The faecal/caecal microbiota was analyzed by next generation sequencing. Disease activity index (DAI) score was evaluated daily. Blood and colon tissue immunophenotyping was assessed by flow cytometry and histological, haematological, and biochemical parameters were also evaluated. The colitis induction was reflected in a significantly higher DAI score and changes in all parameters measured. This study demonstrated significant shifts in the colitis-related microbial species after colitis induction. The characteristic inflammation-associated microbiota could be detected even after a five day-recovery period. Moreover, the DSS-model might contribute to an understanding of the effect of different treatments on extraintestinal organ impairments. The observation that certain bacterial species in the gut microbiota are associated with colitis raises the question of whether these organisms are contributors to, or a consequence of the disease. Despite some limitations, we confirmed the suitability of DSS-induced colitis model to monitor microbial changes during acute colitis, in order to test attractive new microbiome-based therapies.
Examining the Impact of Rotated Neck and Trunk Postures on Vertical Seat-to-Head Vibration Transmissibility and Self-Reported Discomfort
Authors: Goggins Katie , Kelly Elizabeth , Thompson Taryn , Eger Tammy
Published: May 2022

Adopting non-neutral sitting postures while exposed to whole-body vibration (WBV) can put heavy equipment operators at an increased risk for lower back pain and may cause damage to the spinal tissue. A laboratory experiment involving 11 participants (5 females, 6 males) completing four 45-min test sessions incorporating different seated conditions (vibration versus no vibration, and rotation versus no rotation) was used to assess seat-to-head transmissibility (STHT) and self-reported discomfort while in four rotated neck and trunk postures. The vibration exposure profile was a constant vertical sinusoidal signal with a frequency of 3 Hz and 0.7 m/s2 acceleration. Vibration measured at the head was greater than at the seat under all conditions, with a statistically significant effect of time (F1,10 = 101.73, p < 0.001, Eta2 = 0.910) and posture (F3,8 = 5.64, p = 0.023, Eta2 = 0.679). Mean self-reported discomfort ratings revealed increased participant discomfort in rotated neck and trunk positions in both vibration and non-vibration conditions. Increasing time also had a significant (F(1,10) = 15.53, p = 0.003) impact on higher rates of participant discomfort. Overall, it was found that increasing the degree of rotated neck and trunk position from neutral amplified the STHT and self-reported discomfort.
Placed Riprap Deformation Related to Axial Load at Toe Support: Physical Modelling
Authors: Dezert Théo , Ravindra Ganesh Hiriyanna Rao , Sigtryggsdóttir Fjóla Guðrún
Published: May 2022

Rockfill dams are hydraulic structures of major importance. They can be exposed to extreme flood events, in turn leading to overtopping. These phenomena erode and affect structural and geotechnical integrity, which in turn can cause dam breach. Ripraps are broadly used for rockfill dam protection against such erosion processes. For steep slopes, as the one considered in this study (S = 1:1.5, vertical: horizontal), understanding the riprap behavior during overtopping is an important issue to improve dam design and reinforcement techniques. In this work, datasets are obtained from five experimental models of placed riprap built on a rock filter layer in a flume, at the hydraulic laboratory of the Norwegian University of Science and Technology, Trondheim. The riprap stones were placed in an interlocking pattern with a metallic support at the toe. The models were subjected to successive and incremental overtopping discharges until their complete failure. A laser traverse system was used to measure the coordinates (3D) of individual marked riprap stones between each discharge increase. Six load cells located at the toe measured the imposed loads during the entire procedure. From the total load values, two different types of load contributions could be distinguished: the self-weight of the stones and the hydraulic load depending on the discharge level of the overflow. This article highlights the strong relation in each of the five tests between riprap stone displacements, axial reaction load values measured at the toe and overtopping discharges. Moreover, as demonstrated in previous works, a buckling deformation of the riprap layer was observed and described. The results demonstrate that as the hydraulic load induces 2D deformations of the riprap, a larger part of the riprap weight is supported at the toe. Thus, the measured axial load during overtopping arises both from the hydraulic load and from the load imparted due to the compaction of the riprap layer. This compaction effect induces an even greater load than the one imposed due to the hydraulic contribution. The results from this study are finally put into perspective with the Norwegian Water Resources and Energy Directorate recommendations for full scale dams and suggest the great resistance of supported riprap at the toe.
An Equivalent Pipe Network Modeling Approach for Characterizing Fluid Flow through Three-Dimensional Fracture Networks: Verification and Applications
Authors: Zhang Jing , Liu Richeng , Yu Liyuan , Li Shuchen , Wang Xiaolin , Liu Ding
Published: May 2022

The equivalent pipe network (EPN) model is an effective way to model fluid flow in large-scale fractured rock masses with a complex fracture network due to its straightforwardness and computational efficiency. This study presents the EPN model for characterizing fluid flow through three-dimensional fracture networks using the Monte-Carlo method. The EPN model is extracted from an original three-dimensional discrete fracture network (DFN) model and is used to simulate the fluid flow processes. The validity of the proposed EPN modeling approach is verified via the comparisons of permeability (k) with analytical solutions and simulation results reported in the literature. The results show that the numerically calculated k using EPN models agrees well with the analytical values of simplified DFN models and the simulation results of complex DFN models. The k increases following an exponential function with the increment of mean length of exponentially distributed fractures (u), which is strongly correlated with fracture density (P32) and average intersection length (Li). The P32 increases in an exponential way with the increment of u. The Li increases as u increases, following a power-law function. The increment of u leads to the increment of a number of long fractures in three-dimensional DFN models. A larger u results in a denser fracture network and a stronger conductivity when the number and length distribution range of fractures remain the same. The representative elementary volumes (REVs) of three-dimensional DFN models with u = 9 m and P32 = 0.4 m2/m3 are determined as 2.36 × 104 m3, 9.16 × 103 m3, and 1.26 × 104 m3 in 3 flow directions, respectively.
Flood Risk Modeling under Uncertainties: The Case Study of Croatia
Authors: Kekez Toni , Andricevic Roko , Knezic Snjezana
Published: May 2022

This study presents an approach for assessing the flood risk using the fully probabilistic description of the annual damage using the derived higher-order statistical moments of the annual damage random variable. The annual damage distribution is used to analyze the impact on the macro-scale agglomeration described with the unified damage function in the case study of the river Kupa, Croatia. The agglomeration damage function is derived through the unit damage function and estimated distribution of building thresholds within the studied agglomeration. The unit damage is described with the shape function, which can easily accommodate different forms of damage assessment depending on the available information. The estimated distribution of annual maximum flood levels is propagated through the agglomeration damage function into the annual damage distribution derived using higher-order statistical moments and presented with the exceedance probability, indicating the likelihood that a certain annual maximum damage can be exceeded. Besides the aleatory uncertainty of annual maximum flood levels, we analyzed the impact of the uncertainty in estimating the unit damage function upon the annual damage distribution. This uncertainty shows a significant impact on the shape of the annual damage distribution, particularly in the region of extreme flood events. Analyzing the annual damage distribution range, resulting from the uncertainty in damage functions, provides more information to policymakers in assessing the potential consequences on the future spatial planning programs, particularly from the strategic environmental assessment point of view.
Long-, Medium-, and Short-Term Nested Optimized-Scheduling Model for Cascade Hydropower Plants: Development and Practical Application
Authors: Shang Ling , Li Xiaofei , Shi Haifeng , Kong Feng , Wang Ying , Shang Yizi
Published: May 2022

This paper presents a nested approach for generating long-term, medium-term, and short-term reservoir scheduling models, which is based on the actual needs of the scheduling operation of the Three Gorges–Gezhouba (TG-GZB) cascade reservoirs. The approach has established a five-tier optimal scheduling model in which the time interval of the scheduling plan prepared by the model can be as short as 15 min, meeting the real-time scheduling requirements of the cascade hydropower station system. This study also presents a comparatively comprehensive introduction to all solving algorithms that have ever been adopted in the multi-time scale coordinated and optimized scheduling model. Based on that, some practical and efficient solving algorithms are developed for the characteristics of the scheduling model, including the coupled iterative method of alternating reservoirs (CIMAR)—the improved dynamic programming (IDP) algorithm and the improved genetic algorithm (IGA). In addition, optimized-scheduling solutions were generated by each of the three algorithms and were compared in terms of their convergence rate, calculation time, electric energy generated, and standard deviation of the algorithm. The results based on the Cascade Scheduling and Communication System (CSCS) of Three Gorges–Gezhouba, China, which includes two interlinked mega-scale reservoir projects, show that scheduling models have better efficiency and good convergence, and more importantly, the maximization of the power generation benefits of the hydropower plants has been achieved without violating any of the reservoir scheduling regulations.
Genesis of Geothermal Waters in Suichuan County, China: An Integrated Method Constrained by the Hydrochemical and Isotopic Characteristics
Authors: Akram Waseem , Chen Wei , Huang Changsheng , Hou Baoquan , Wang Xianguang , Bai Ximin , Feng Shuangshou , Arifullah  , Hussain Hadi , Hussain Javid , Han Wenjing , Hussain Sadam
Published: May 2022

Numerous geothermal resources of medium to low temperature have been reported in southern China. Suichuan County is one of the regions where thermal manifestations are abundant. However, the study regarding the understanding of geothermal water sources, hydrochemical composition and fluid-rock interaction lacks behind. Therefore, this study has characterized the slightly acidic to slightly alkaline bicarbonate geothermal waters of medium-low temperature of the Suichuan area. Geothermal waters of the study area have been evaluated mainly as of HCO3-Ca-Na hydrochemical type with a maximum temperature of 80 °C. The results indicate the low hydrochemical concentration where HCO3− acts as a principal anion. Furthermore, the F− content in geothermal and two cold water samples have been found high with a maximum value of 13.4 (mg/L), showing high pH of 9.6 as well. Here, the compilation of deuterium and oxygen-18 isotopic data of geothermal waters showed a local precipitation origin with a recharge elevation ranging from 630–1000 m. The circulation depth and reservoir temperatures are estimated, explaining the deep thermal water behavior. Additionally, the estimation of saturation indices of various minerals shows the geothermal waters’ corrosive or scaling behavior. Subsequently, the geothermal water points in the study area represent a fracture convection formation pattern. Finally, by integrating conventional hydrochemistry along with isotopic data, and considering the geological framework, a conceptual genetic model of the Suichuan thermal ground waters has been discussed. Hydrochemistry and isotopic features along with a conceptual circulation model have been provided by the foundation towards the sustainable management of hydrothermal resources in Suichuan. Proper management policies and practices are required for further development of Suichuan hydrothermal waters.
Unfavorable Geology and Mitigation Measures for Water Inrush Hazard during Subsea Tunnel Construction: A Global Review
Authors: Niu Fangyuan , Cai Yuancheng , Liao Hongjian , Li Jigang , Tang Kunjie , Wang Qiang , Wang Zhichao , Liu Dedi , Liu Tong , Liu Chi , Yang Tao
Published: May 2022

Water inrush hazard seriously threatens construction safety of subsea tunnels in unfavorable geological areas. In recent years, a large number of subsea tunnels have been built worldwide, some of which have experienced many water inrush disasters, especially in Japan and Norway. In this paper, a systematic methodology is proposed to rigorously review the current literature about water inrush in subsea tunnels. Emphasis is placed on recorded causes and evolution processes of water inrush, as well as relevant mitigation measures. In particular, the geological conditions that generate such water inrush hazards are initially discussed by counting cases of tunnel water inrush in the past decades (43 cases of water inrush hazards in tunnels (including mountain tunnels)). The process of formation of failure modes of water inrush, and the corresponding research methods (including theoretical, numerical and experimental) are reviewed, and can be used to pave the ways for hazard prevention and future research. This is followed by a summary of the prevention methods and mitigation measures used in practice, and a short discussion of the achievements and limitations of each method. Then combined with the evolution characteristics of the failure area, the water inrush process of different modes is divided into three stages, with a proposed a grouting scheme for each stage. Finally, concluding remarks, current research gaps and future research directions on subsea tunnel water inrush are provided and discussed.
Genotoxicity Set Up in Artemia franciscana Nauplii and Adults Exposed to Phenanthrene, Naphthalene, Fluoranthene, and Benzo(k)fluoranthene
Authors: Albarano Luisa , Serafini Sara , Toscanesi Maria , Trifuoggi Marco , Zupo Valerio , Costantini Maria , Vignati Davide A. L. , Guida Marco , Libralato Giovanni
Published: May 2022

Polycyclic aromatic hydrocarbons (PAHs) consist of a group of over 100 different organic compounds mainly generated by anthropogenic activities. Because of their low water solubility, they tend to be accumulated in sediment, where their degradation rate is very low. Few studies have been carried out so far to investigate the effects of PAHs on Artemia franciscana. Artemia is easy to manage at laboratory scale, but it is not a sensitive biological model considering the traditional endpoints (i.e., mortality). In addition to evaluating the lethality on nauplii and adults of A. franciscana after 24 and 48 h, we focused on the genotoxicity to investigate the potential effects of phenanthrene (PHE), naphthalene (NAP), fluoranthene (FLT), and benzo(k)fluoranthene (BkF). Results showed that FLT was the most toxic both for nauplii and adults after 48 h of exposure. Real-time qPCR showed that all toxicants, including BkF, which had no negative effects on the survival of the crustacean, were able to switch the gene expression of all nine genes. This work has important ecological implications, especially on contaminated sediment assessment considering that PAHs represent the most abundant organic group of compounds in marine environment, opening new perspectives in understanding the molecular pathways activated by crustaceans.
Identification, Abundance, and Chemical Characterization of Macro-, Meso-, and Microplastics in the Intertidal Zone Sediments of Two Selected Beaches in Sabah, Malaysia
Authors: Zahari Nur Zaida , Tuah Piakong Mohd , Junaidi Muhammad Ramdi , Mohd Ali Siti Aishah
Published: May 2022

This study aims to present the identification, abundance, and chemical characterization of plastics in the intertidal zone sediment of two selected beaches in Kota Kinabalu city, Sabah, Malaysia. Plastic debris was classified according to weight and size and was identified for its heavy metal concentrations and polymer types. Results showed that a higher abundance, by more than 2-fold, of plastic debris was found in Kebagu beach (28.7 g) compared to ODEC, UMS (13.4 g). FTIR analysis showed that polypropylene (PP) and polyethylene (PE) were the dominant plastic polymers on both beaches, followed by polystyrene (PS) and polyethylene terephthalate (PET). Five heavy metals (arsenic, chromium, copper, zinc, and nickel) were detected from four types of plastics. The results showed that the concentration of Zn was higher in all four types of plastics on both beaches, with a range of 41 mg/kg–135.3 mg/kg, followed by Cr and As, while Ni was the lowest concentration detected in PE on both beaches: 5.6 mg/kg (ODEC) and 5.1 mg/kg (Kebagu stations). This study confirmed the presence of macro-, meso- and microplastics in both stations. Further studies remain necessary for a better understanding of the sources and fates of the pollutant in the marine environment. Findings from the studies of the Kota Kinabalu beaches have provided baseline data and a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions are required to mitigate the potential risk to the ecological system and human health.
Assessment of Annual Erosion and Sediment Yield Using Empirical Methods and Validating with Field Measurements—A Case Study
Authors: Tabarestani Ehsan Shahiri , Afzalimehr Hossein , Sui Jueyi
Published: May 2022

To implement soil conservation approaches, it is necessary to estimate the amount of annual sediment production from a watershed. The purpose of this study was to determine the erosion intensity and sedimentation rate from a watershed by employing empirical models, including the modified Pacific Southwest Inter-Agency Committee (MPSIAC), the erosion potential method (EPM), and Fournier. Moreover, the accuracy of these empirical models was studied based on field measurements. Field measurements were conducted along two reaches of Babolroud River. Total sediment transport, including suspended load and bed load, was predicted. Bed load transport rate was measured using a Helly–Smith sampler, and suspended load discharge was calculated by a sediment rating curve. The results of this study indicate that the erosion intensity coefficient (Z) of the Babolroud watershed is 0.54, with a deposition rate of 166.469 m3/(km2.year). Due to the existence of unusable crops, the highest amount of erosion appeared in the northern region of the watershed. The results using the EPM and MPSIAC models were compared with field measurements and indicated that both models provided good accuracy, with differences of 22.42% and 20.5% from the field results, respectively. Additionally, it could be concluded that the Fournier method is not an efficient method since it is unable to consider the erosion potential.
Characterization of South African Brewery Wastewater: Oxidation-Reduction Potential Variation
Authors: Khumalo Siphesihle Mangena , Bakare Babatunde Femi , Rathilal Sudesh , Tetteh Emmanuel Kweinor
Published: May 2022

Conventional wastewater treatment processes are challenged by the need to effectively reduce pollutant loads before disposal or reuse, as the composition and concentration of contaminants in brewery wastewater change with time. This results in the variation of the oxidation-reduction potential (ORP) of the affluent. Hence, the current study is aimed at the application of ORP as a real-time tool to monitor brewery wastewater quality. Other physicochemical parameters of the local brewery in South Africa investigated included temperature (T), pH, conductivity, turbidity, total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), particulate chemical oxygen demand (PCOD), total solids, orthophosphate, ammoniacal nitrogen, total Kjeldahl nitrogen (TKN), total nitrogen (TN), nitrate, and nitrite nitrogen. It was found that the ORP decreased (135 to −305 mV) with an increase in alkalinity (pH 4.4 to 12.2) with linear regression coefficient fit (R2 = 0.9994). The ORP facilitated the wastewater nutrient constituent degradability which improved the water quality. Furthermore, the high organic content of the brewery wastewater was found as measured by total COD (3447–11,813 mg/L). This suggests remediation before reuse of the brewery wastewater will require a robust integrated wastewater treatment process.