bluuebunny/crossref_metadata_2025 huggingface dataset:
Dispersal Characteristics and Pathways of Japanese Glass Eel in the East Asian Continental Shelf
Authors: Han Yu-San , Hsiung Kuan-Mei , Zhang Heng , Chow Lai-Yin , Tzeng Wann-Nian , Shinoda Akira , Yoshinaga Tatsuki , Hur Sung-Pyo , Hwang Sun-Do , Iizuka Yoshiyuki , Kimura Shingo
Published: May 2019

The Japanese eel Anguilla japonica is an important aquaculture fish species in the East Asian countries of Japan, China, Korea, and Taiwan. All glass eel fry are captured from the wild and understanding the recruitment patterns of the glass eel is important. The larvae of A. japonica are passively transported to the East Asian Continental Shelf by the North Equatorial Current, the Kuroshio, the Kuroshio intrusion currents, and coastal currents. In each location, recruitment time is diverse: It is November in Taiwan and April in the Yalu River. How the glass eels reach recruitment areas remains poorly understood. Here, we combine information from larval ages based on otolith increments, simulated drifting paths on the East Asian Continental Shelf, and main fishing seasons in each location of East Asia. We identify five main recruitment blocks: (1) The main Kuroshio, (2) The Taiwan Strait Warm Current, (3) The Taiwan Warm Current, (4) The Yellow Sea Warm Current and (5) The branch of Yellow Sea Warm Current. The counted age of the glass eels is significantly underestimated for the later recruits, possibly due to the cessation of the otolith edge growth under low water temperatures. This study clarifies the eel’s larval characteristics and transport mechanisms in the East Asia Continental Shelf, providing important information for its recruitment dynamics in the marine stage.
Landscape Design as a Tool to Reduce Soil Salinization: The Study Case of Keriya Oasis (NW China)
Authors: Seydehmet Jumeniyaz , Lv Guang-Hui , Abliz Abdugheni
Published: May 2019

Irrational use and management of water and land are associated with poor hydro-geological conditions causing water logging and salinization problems, possibly leading to farmland abandonment and economic loss. This poses a great challenge to the sustainability of oasis’ and requires desalinization through reasonable landscape design by multiple crossing studies so we collected traditional knowledge by field interviews and literature schemes, except for the modern desalinization approaches by literature, and we found that the salinization problem has been solved by traditional land reclamation, traditional drainage, natural drainage and flood irrigation, locally. It is worth mentioning that the traditional reclamation in salinized areas requires flood water, sand dunes and a salinized pit area; the sand dunes are used to elevate the pit surface, and water is used to leach salt from the soil. Natural drainage (the depth and width are 4–10 m and 50–100 m, respectively) caused by flash flooding has significant benefits to some salinized villages in the range of 3000–5000 m and ancient groundwater drainage systems, such as Karez are supporting the oasis with drainage water for centuries. In addition landscape characteristics, salinization and hydro-geological conditions of the oasis were studied from Landsat image, DEM, literature and field photos. Then based on the gathered information above, a desalinization model was developed to decrease the groundwater table and salt leaching in the water logging landscape. Then according to landscape characteristics, different desalinization approaches were recommended for different landscapes. To address environmental uncertainties, an adaptive landscape management and refinement approach was developed, and acceptance of the model was validated by stakeholder opinion. The results provide guidelines for sustainable desalinization design and highlight the importance of combining traditional knowledge and modern ecological principles in sustainable landscape design.
Progress and Stagnation of Renovation, Energy Efficiency, and Gentrification of Pre-War Walk-Up Apartment Buildings in Amsterdam Since 1995
Authors: Oorschot Leo , De Jonge Wessel
Published: May 2019

Increasing the energy efficiency of the housing stock has been one of the largest challenges of the built environment in the Netherlands in recent decades. Parallel with the energy transition there is an ongoing revaluation of the architectural quality of pre-war residential buildings. In the past, urban renewal was traditionally based on demolition and replacement with new buildings. This has changed to the improvement of old buildings through renovation. Housing corporations developed an approach for the deep renovation of their housing stock in the period 1995–2015. The motivation to renovate buildings varied, but the joint pattern that emerged was quality improvement of housing in cities, focusing particularly on energy efficiency, according to project data files from the NRP institute (Platform voor Transformatie en Renovatie). However, since 2015 the data from the federation of Amsterdam-based housing associations AFWC (Amsterdamse Federatie Woningcorporaties) has shown the transformation of pre-war walk-up apartment buildings has stagnated. The sales of units are slowing down, except in pre-war neighbourhoods. Housing associations have sold their affordable housing stock of pre-war property in Amsterdam inside the city’s ring road. The sales revenue was used to build new affordable housing far beyond the ring road. This study highlights the profound influence of increasing requirements established by the European Energy Performance of Building Directive (EPBD) and the revised Housing Act of 1 July 2015, for the renovation of the pre-war housing stock. The transformation process to climate-neutral neighbourhoods inside the ring road is slowing down because of new property owners, making a collective heat network difficult to realize; furthermore, segregation of residents is appearing in Amsterdam.
Stability of Ecosystem CO2 Flux in Response to Changes in Precipitation in a Semiarid Grassland
Authors: Bao Kaiqiang , Tian Haifeng , Su Min , Qiu Liping , Wei Xiaorong , Zhang Yanjiang , Liu Jian , Gao Hailong , Cheng Jimin
Published: May 2019

Carbon dioxide (CO2) flux provides feedback between C cycling and the climatic system. There is considerable uncertainty regarding the direction and magnitude of the responses of this process to precipitation changes, hindering accurate prediction of C cycling in a changing world. We examined the responses of ecosystem CO2 flux to ambient precipitation and experimentally decreased (−35%) and increased precipitation (+20%) in a semiarid grassland in China between July 2013 and September 2015. The measured CO2 flux components included the gross ecosystem productivity (GEP), net ecosystem CO2 exchange (NEE), ecosystem respiration (Re), and soil respiration (Rs). The results showed that the seasonal and diurnal patterns of most components of ecosystem CO2 flux were minimally affected by precipitation treatments, with less than 4% changes averaged across the three growing seasons. GEP and NEE had a quadratic relationship, while Re and Rs increased exponentially with soil temperature. GEP, RE, and Rs, however, decreased with soil moisture. Decreased precipitation reduced the dependence of CO2 flux on soil temperature but partly increased the dependence on soil moisture; in contrast, increased precipitation had the opposite influence. Our results suggested a relatively stable CO2 flux in this semiarid grassland across the tested precipitation regimes.
Belowground Bud Bank Distribution and Aboveground Community Characteristics along Different Moisture Gradients of Alpine Meadow in the Zoige Plateau, China
Authors: Ding Xinjing , Su Peixi , Zhou Zijuan , Shi Rui
Published: May 2019

The belowground bud bank plays an important role in plant communities succession and maintenance. In order to understand the response of the bud bank to the sod layer moisture, we investigated the bud bank distribution, size, and composition of six different water gradient alpine meadows through excavating in the Zoige Plateau. The results showed: (1) The alpine meadow plant belowground buds were mainly distributed in the 0–10 cm sod layer, accounting for 74.2%–100% of the total. The total bud density of the swamp wetland and degraded meadow was the highest (16567.9 bud/m3) and the lowest (4839.5 bud/m3). (2) A decrease of the moisture plant diversity showed a trend of increasing first and then decreasing. Among six alpine meadows the swamp meadow plant diversity was the highest, and species richness, Simpson, Shannon–Wiener, and Pielou were 10.333, 0.871, 0.944, and 0.931, respectively. (3) The moisture was significantly positively correlated with the total belowground buds and short rhizome bud density. There were significant positive correlations with sod layer moisture and tiller bulb bud density. This study indicates that the moisture affected bud bank distribution and composition in the plant community, and the results provide important information for predicting plant community succession in the alpine meadow with future changes in precipitation patterns.
A Systems Analysis Approach to Identifying Critical Success Factors in Drinking Water Source Protection Programs
Authors: Merrett Hew Cameron , Chen Wei Tong , Horng Jao Jia
Published: May 2019

The success of source protection in ensuring safe drinking water is centered around being able to understand the hazards present in the catchment then plan and implement control measures to manage water quality risk to levels which can be controlled through downstream barriers. The programs in place to manage source protection are complex sociotechnical systems involving policy, standards, regulators, technology, human factors and so on. This study uses System Theoretic Process Analysis (STPA) to analyze the operational hazards of a typical drinking water source protection (DWSP) program and identify countermeasures to ensure safe operations. To validate the STPA results a questionnaire was developed based on selective grouping of the initial countermeasures identified and distributed to specialists in DWSP in Taiwan, Australia and Greece. Through statistical analysis using Principle Components Analysis (PCA), the study identified four critical success factors (CSFs) for DWSP based on the questionnaire responses. The four CSFs identified were “Policy and Government Agency Support of Source Protection”, “Catchment Risk Monitoring and Information”, “Support of Operational Field Activities” and “Response to Water Quality Threats”. The results of this study provide insight into the approach of grouping of source protection measures to identify a series of targeted CSF for operational source protection programs. Using CSF can aid catchment management agencies in ensuring that the risk level in the catchment is managed effectively and that threats to public health from drinking water are managed appropriately.
Align My Curriculum: A Framework to Bridge the Gap between Acquired University Curriculum and Required Market Skills
Authors: Almaleh Ahood , Aslam Muhammad Ahtisham , Saeedi Kawther , Aljohani Naif Radi
Published: May 2019

With the advancement of technology, academics and curriculum developers are always under pressure to provide students with skills that match the market’s requirements. A systematic and continuous examination of the market is needed, to stay up to date with the required skills, and then to update the curriculum to train the students with required market skills. In this article, we present a framework referred to as Align My Curriculum (AMC). The AMC framework aims to facilitate alignment between acquired university curriculum outcomes and required market skills. It can be used to classify, compare and visualize the data of a university curriculum and job vacancies in the market. The presented framework benefits academics and curriculum developers by improving the courses and therefore bridging the skills gap. Stakeholders from both academia and industry can gain insights into the predominant required and acquired skills. In addition, it may be useful for analysts, students, and job applicants. This article describes the architecture, implementation and experimental results, with visual analysis to help decision and policy-makers.
The Multi-Risk Assessment Approach as a Basis for the Territorial Resilience
Authors: Pilone Eleonora , Demichela Micaela , Baldissone Gabriele
Published: May 2019

The deep modifications to climate are currently provoking risks of increasing impact, that can cause unexpected consequences, interacting with other risks. However, the available planning regulations and instruments appear inadequate to face this challenge, most of all at a local scale. This paper presents a semi-quantitative methodology for the assessment of multiple risks, developed for the direct use of the municipality technicians, in order to increase their awareness towards multiple risks and unexpected events that could hit their territory. The methodology is based on the assignation of rates to the risks, and on a simple calculation of the binary interactions. It was tested on two Italian case studies, revealing a good feasibility in the results obtained for the interactions, and highlighting some problems neglected in the sectorial risk plans. The methodology is a background knowledge of the ‘Responsible Risk Resilience Center’ (R3C) of Politecnico di Torino, and it was furtherly developed through an in-depth analysis of the territorial vulnerabilities. This paper introduces two new indicators of sensitivity towards external risks, related to fire and flood risks, proposed for the application at a local scale. The indicators belong to a wider R3C framework in the phase of development to operationalize resilience.
Exploring the Determinants of Hot Spring Tourism Customer Satisfaction: Causal Relationships Analysis Using ISM
Authors: Mi Chuanmin , Chen Yetian , Cheng Chiung-Shu , Uwanyirigira Joselyne Lucky , Lin Ching-Torng
Published: May 2019

To stand out in the hot spring tourism industry, customer satisfaction has become the crucial issue for competitiveness. A company cannot implement several customer satisfaction improvement practices altogether with limited resources. Researchers advocate that companies should evaluate the relationships among success factors and explore determinants for their improvement implementation. However, such a relationship evaluation has not yet been adequately performed. This paper intends to explore the determinants for improving hot spring customer satisfaction. Adopting grounded theory (GT) and using data collected from websites, Ctrip and Qunar, the first 12 key factors for customer satisfaction were identified. Then, their interrelationships were assessed by 15 experts, and interpretive structural modeling (ISM) was employed to analyze the interrelationships and the driving and dependence power among key factors. The results show that “Environment Quality”, “Special Resource”, “Convenience”, “Food”, Service Quality”, and “Facilities” were the decisive factors affecting customer satisfaction. The findings offer important implications for hot spring management and practice. The contribution of this study is using a novel approach to establish a hierarchical structural model for comprehensive understanding of factor relationships that influence hot spring tourists’ satisfaction and to explore decisive factors which can help hot spring practitioners to better plan and design effective improvement strategies to attract potential new consumers and retain their current consumers, especially with limited resources.
Multi-Objective Service Selection and Scheduling with Linguistic Preference in Cloud Manufacturing
Authors: He Wei , Jia Guozhu , Zong Hengshan , Kong Jili
Published: May 2019

Service management in cloud manufacturing (CMfg), especially the service selection and scheduling (SSS) problem has aroused general attention due to its broad industrial application prospects. Due to the diversity of CMfg services, SSS usually need to take into account multiple objectives in terms of time, cost, quality, and environment. As one of the keys to solving multi-objective problems, the preference information of decision maker (DM) is less considered in current research. In this paper, linguistic preference is considered, and a novel two-phase model based on a desirable satisfying degree is proposed for solving the multi-objective SSS problem with linguistic preference. In the first phase, the maximum comprehensive satisfying degree is calculated. In the second phase, the satisfying solution is obtained by repeatedly solving the model and interaction with DM. Compared with the traditional model, the two-phase is more effective, which is verified in the calculation experiment. The proposed method could offer useful insights which help DM balance multiple objectives with linguistic preference and promote sustainable development of CMfg.
Perspectives of Socio-Spatial Differentiation from Soaring Housing Prices: A Case Study in Nanjing, China
Authors: Liu Chunhui , Song Weixuan
Published: May 2019

Launched in 1998, the market-oriented reform of urban housing has given urban housing the dual attributes of residence and investment, and led to the rapid growth of housing prices as well as the intensification of its spatial differentiation within cities. However, the spatial patterns of the differentiation and its mechanism as well as socio-spatial effects are rarely touched. This paper studies 3963 urban residential districts in central Nanjing and explores the socio-spatial differentiation pattern and process of the urban housing prices and its growth in Nanjing based on the sample data of housing transactions over 30 quarters during the period of 2009–2017. The paper concludes that, by splitting the research duration into phases of six quarters each, the average housing prices in Nanjing alternates between “rapid growth” and “relatively stable” phases. At the same time, this paper finds that the spatial heterogeneity of housing prices in the city has been enhanced constantly, and the price gap in different types of residential housing has been clearly widened. In combination with the price level, location characteristics and architectural attributes of residential districts, this paper has categorized housing in Nanjing into nine typical types in a comprehensive manner. Based on the differences in their spatial attributes such as location, comfort and scarcity etc., different types of residences exhibit different pricing and price-to-rent ratio growth models. Based on those findings, we discussed the mechanism of the socio-spatial differentiation of housing prices in Nanjing from the housing reform and strategies of urban renewal and expansion. Beyond that, we discussed the role of urban housing consumption in the process of (re)production of urban classes, and its negative effects on urban young people, rural immigrants and other disadvantaged families. At the end of the paper, the policy suggestion about the supply-side reform of the housing market to promote socio-spatial equity and sustainable development is also presented.
LED Light Sources and Their Complex Set-Up for Visually and Biologically Effective Illumination for Ornamental Indoor Plants
Authors: Zielinska-Dabkowska Karolina M. , Hartmann Julia , Sigillo Carla
Published: May 2019

Ornamental plants are often used in indoor environments as part of biophilic design to improve the health and wellbeing of occupants, and to support sustainable, green architecture. Unfortunately, many plants do not thrive and need to be continuously replaced, which is economically unsustainable. The wavelengths and spectrum ratio of commonly used light sources such as light emitting diode (LED), and the lack of an appropriate light dark cycle (photoperiod), appear to be crucial influencing factors. Therefore, this study focuses on determining the optimal action spectrum of LEDs for visually and biologically effective illumination for plants, and humans as end users. This practice-based research study applies critical analysis of literature, photographic evaluation of the appearance of plants under various LED lighting in the form of a visual assessment questionnaire-based survey, and provides various measurements that record the properties of light including correlated color temperature (CCT), color rendering index (CRI), spectral power distribution (SPD), peak light wavelength (λP), photosynthetic photon flux density (PPFD) and daily light integrals (DLI). Research confirms the LED lighting used for horticultural food production cannot be applied to ornamental indoor plants due to fundamental differences in purpose. Such illumination provides fast growth for market consumption and usually makes plants appear unnatural, whereas ornamental plants in an indoor environment should grow at an appropriate speed which reduces maintenance costs and they should have a natural appearance. These new findings, supported by evidence and data, can help investors, clients, architects, landscape and lighting designers, as well as luminaire manufacturers, make improved, biophilic-sustainable lighting design choices.
Greenwash and Green Purchase Intention: The Mediating Role of Green Skepticism
Authors: Nguyen Thi Thu Huong , Yang Zhi , Nguyen Ninh , Johnson Lester W. , Cao Tuan Khanh
Published: May 2019

Along with the acceleration of green marketing in recent years, greenwash has been utilized by firms to get ahead of their rivals. Underpinned by the cognition–affect–behavior (C-A-B) paradigm, this study examines a model linking greenwash and green skepticism with green purchase intentions. It also investigates the moderating role of information and knowledge on the relationship between greenwash and green purchase intentions. Data were obtained from 419 Vietnamese consumers who had been involved in purchasing green vegetables using an online survey. Multivariate data analysis demonstrated that greenwash was negatively associated with green purchase intentions and that green skepticism mediated this negative association. In addition, the moderating effect of information and knowledge was confirmed. These findings enrich the extant knowledge on the relationship between greenwash and green purchase intentions. They also have important implications for firms that aim to reduce consumers’ skepticism and increase their intentions to purchase green food.
Challenges Addressed by Swedish Third-Party Logistics Providers Conducting Sustainable Logistics Business Cases
Authors: Björklund Maria , Forslund Helena
Published: May 2019

The sustainable logistics business case (SLBC) provides underlying argumentation to convince decision makers to approve initiatives within sustainable logistics. Little knowledge exists on how companies conduct SLBCs or the challenges that need to be addressed. The purpose of this paper is to explore how companies conduct SLBCs, to increase the understanding of how perceived challenges can be addressed. Potential challenges were identified in literature on business cases models in general and sustainable logistics business cases. As third-party logistics providers (3PL) are big contributors to emissions and often are responsible for designing logistics setups, they were focused in the empirical study. How SLBC were conducted was investigated based on interviews with managers responsible for conducting SLBCs and the responses triangulated with information derived from actual business cases. Despite the careful selection of 3PLs well ahead within the area, few challenges were perceived by the studied companies. This does not imply that challenges do not exist but can rather be described as a consequence of their pragmatic and inward-looking perspective. Examples of how to address challenges are provided. The compiled list of SLBC challenges provides an overview that was missing in literature.
Conservation Laws and Stability of Field Theories of Derived Type
Authors: Kaparulin Dmitry
Published: May 2019

We consider the issue of correspondence between symmetries and conserved quantities in the class of linear relativistic higher-derivative theories of derived type. In this class of models the wave operator is a polynomial in another formally self-adjoint operator, while each isometry of space-time gives rise to the series of symmetries of action functional. If the wave operator is given by n-th-order polynomial then this series includes n independent entries, which can be explicitly constructed. The Noether theorem is then used to construct an n-parameter set of second-rank conserved tensors. The canonical energy-momentum tensor is included in the series, while the other entries define independent integrals of motion. The Lagrange anchor concept is applied to connect the general conserved tensor in the series with the original space-time translation symmetry. This result is interpreted as existence of multiple energy-momentum tensors in the class of derived systems. To study stability we seek for bounded-conserved quantities that are connected with the time translations. We observe that the derived theory is stable if its wave operator is defined by a polynomial with simple and real roots. The general constructions are illustrated by the examples of the Pais–Uhlenbeck oscillator, higher-derivative scalar field, and extended Chern–Simons theory.
Two-Phase Couette Flow of Couple Stress Fluid with Temperature Dependent Viscosity Thermally Affected by Magnetized Moving Surface
Authors: Ellahi Rahmat , Zeeshan Ahmed , Hussain Farooq , Abbas Tehseen
Published: May 2019

The Couette–Poiseuille flow of couple stress fluid with magnetic field between two parallel plates was investigated. The flow was driven due to axial pressure gradient and uniform motion of the upper plate. The influence of heating at the wall in the presence of spherical and homogeneous Hafnium particles was taken into account. The temperature dependent viscosity model, namely, Reynolds’ model was utilized. The Runge–Kutta scheme with shooting was used to tackle a non-linear system of equations. It was observed that the velocity decreased by increasing the values of the Hartman number, as heating of the wall reduced the effects of viscous forces, therefore, resistance of magnetic force reduced the velocity of fluid. However, due to shear thinning effects, the velocity was increased by increasing the values of the viscosity parameter, and as a result the temperature profile also declined. The suspension of inertial particles in an incompressible turbulent flow with Newtonian and non-Newtonian base fluids can be used to analyze the biphase flows through diverse geometries that could possibly be future perspectives of proposed model.
Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors
Authors: Baek Hyeongboo , Lee Jaewoo
Published: May 2019

Hard real-time systems are employed in military, aeronautics, and astronautics fields where deployed systems are susceptible to software faults that can result in functional errors. Thus, there is a need to use fault-tolerant (FT) real-time scheduling. Among the various fault-tolerant real-time scheduling techniques, re-execution has been applied widely to existing real-time systems owing to its simplicity and applicability. However, re-execution requires multiple executions of every task, and some tasks miss their deadlines owing to the prolonged execution time; therefore, it has been found to be suitable for only soft real-time systems. In this paper, we propose an FT policy that can be incorporated into most (if not all) existing real-time scheduling algorithms on multiprocessor systems, which improves the reliability of the target system without a tradeoff against schedulability. As a case study, we apply the FT policy to existing fixed-priority scheduling and earliest deadline zero-laxity scheduling, and we demonstrate that it enhances reliability without schedulability loss.
Selective Maintenance Optimization for a Multi-State System Considering Human Reliability
Authors: Zhao Zhonghao , Xiao Boping , Wang Naichao , Yan Xiaoyuan , Ma Lin
Published: May 2019

In an actual industrial or military operations environment, a multi-state system (MSS) consisting of multi-state components often needs to perform multiple missions in succession. To improve the probability of the system successfully completing the next mission, all the maintenance activities need to be performed during maintenance breaks between any two consecutive missions under limited maintenance resources. In such case, selective maintenance is a widely used maintenance policy. As a typical discrete mathematics problem, selective maintenance has received widespread attention. In this work, a selective maintenance model considering human reliability for multi-component systems is investigated. Each maintenance worker can be in one of multiple discrete working levels due to their human error probability (HEP). The state of components after maintenance is assumed to be random and follow an identified probability distribution. To solve the problem, this paper proposes a human reliability model and a method to determine the state distribution of components after maintenance. The objective of selective maintenance scheduling is to find the maintenance action with the optimal reliability for each component in a maintenance break subject to constraints of time and cost. In place of an enumerative method, a genetic algorithm (GA) is employed to solve the complicated optimization problem taking human reliability into account. The results show the importance of considering human reliability in selective maintenance scheduling for an MSS.
NMR-Based Metabolic Profiles of Intact Zebrafish Embryos Exposed to Aflatoxin B1 Recapitulates Hepatotoxicity and Supports Possible Neurotoxicity
Authors: Zuberi Zain , Eeza Muhamed N. H. , Matysik Joerg , Berry John P. , Alia A.
Published: May 2019

Aflatoxin B1 (AFB1) is a widespread contaminant of grains and other agricultural crops and is globally associated with both acute toxicity and carcinogenicity. In the present study, we utilized nuclear magnetic resonance (NMR), and specifically high-resolution magic angle spin (HRMAS) NMR, coupled to the zebrafish (Danio rerio) embryo toxicological model, to characterize metabolic profiles associated with exposure to AFB1. Exposure to AFB1 was associated with dose-dependent acute toxicity (i.e., lethality) and developmental deformities at micromolar (≤ 2 µM) concentrations. Toxicity of AFB1 was stage-dependent and specifically consistent, in this regard, with a role of the liver and phase I enzyme (i.e., cytochrome P450) bioactivation. Metabolic profiles of intact zebrafish embryos exposed to AFB1 were, furthermore, largely consistent with hepatotoxicity previously reported in mammalian systems including metabolites associated with cytotoxicity (i.e., loss of cellular membrane integrity), glutathione-based detoxification, and multiple pathways associated with the liver including amino acid, lipid, and carbohydrate (i.e., energy) metabolism. Taken together, these metabolic alterations enabled the proposal of an integrated model of the hepatotoxicity of AFB1 in the zebrafish embryo system. Interestingly, changes in amino acid neurotransmitters (i.e., Gly, Glu, and GABA), as a key modulator of neural development, supports a role in recently-reported neurobehavioral and neurodevelopmental effects of AFB1 in the zebrafish embryo model. The present study reinforces not only toxicological pathways of AFB1 (i.e., hepatotoxicity, neurotoxicity), but also multiple metabolites as potential biomarkers of exposure and toxicity. More generally, this underscores the capacity of NMR-based approaches, when coupled to animal models, as a powerful toxicometabolomics tool.
Recombinant Aflatoxin-Degrading F420H2-Dependent Reductase from Mycobacterium smegmatis Protects Mammalian Cells from Aflatoxin Toxicity
Authors: Li Che-Hsing , Li Wei-Yang , Hsu I-Ning , Liao Yung-Yu , Yang Chi-Ya , Taylor Matthew C. , Liu Yu-Fan , Huang Wei-Hao , Chang Hsiang-Hua , Huang Ho-Lo , Lo Shao-Chi , Lin Ting-Yu , Sun Wei-Che , Chuang Ya-Yi , Yang Yu-Chieh , Fu Ru-Huei , Tsai Rong-Tzong
Published: May 2019

Aflatoxins are carcinogenic secondary metabolites of fungi that contaminate many staple crops and foods. Aflatoxin contamination is a worldwide problem, especially in developing countries, posing health hazards, e.g., causing aflatoxicosis and hepatocellular carcinoma, and even death. Biological solutions for aflatoxin detoxification are environmentally friendly and a cheaper alternative than chemical methods. The aims of the current study were to investigate: (1) the ability of MSMEG_5998, an aflatoxin-degrading F420H2-dependent reductase from Mycobacterium smegmatis, to degrade aflatoxin B1 (AFB1) and reduce AFB1-caused damage in HepG2 cell culture model; and (2) whether a thioredoxin (Trx) linkage of MSMEG_5998 enhanced the enzyme activity. We show that Trx-linked MSMEG_5998 degraded 63% AFB1 and native MSMEG_5998 degraded 31% after 4 h at 22 °C, indicating that the Trx-linked enzyme had a better AFB1-degrading ability. In a HepG2 cell culture model, Trx-linked MSMEG_5998 reduced DNA damage and p53-mediated apoptosis caused by AFB1 to a greater extent than the native enzyme. These findings suggest that Trx-linked MSMEG_5998 could potentially be developed to protect the liver from AFB1 damage, or as a candidate protein to reduce AFB1-related toxicity in animals.
Toxin–Antitoxin Systems in Bacillus subtilis
Authors: Brantl Sabine , Müller Peter
Published: May 2019

Toxin–antitoxin (TA) systems were originally discovered as plasmid maintenance systems in a multitude of free-living bacteria, but were afterwards found to also be widespread in bacterial chromosomes. TA loci comprise two genes, one coding for a stable toxin whose overexpression kills the cell or causes growth stasis, and the other coding for an unstable antitoxin that counteracts toxin action. Of the currently known six types of TA systems, in Bacillus subtilis, so far only type I and type II TA systems were found, all encoded on the chromosome. Here, we review our present knowledge of these systems, the mechanisms of antitoxin and toxin action, and the regulation of their expression, and we discuss their evolution and possible physiological role.
Reconstruction of Mimetic Gravity in a Non-Singular Bouncing Universe from Quantum Gravity
Authors: de Cesare Marco
Published: May 2019

We illustrate a general reconstruction procedure for mimetic gravity. Focusing on a bouncing cosmological background, we derive general properties that must be satisfied by the function f(□ϕ) implementing the limiting curvature hypothesis. We show how relevant physical information can be extracted from power-law expansions of f in different regimes, corresponding e.g., to the very early universe or to late times. Our results are then applied to two specific models reproducing the cosmological background dynamics obtained in group field theory and in loop quantum cosmology, and we discuss the possibility of using this framework as providing an effective field theory description of quantum gravity. We study the evolution of anisotropies near the bounce, and discuss instabilities of scalar perturbations. Furthermore, we provide two equivalent formulations of mimetic gravity: one in terms of an effective fluid with exotic properties, the other featuring two distinct time-varying gravitational “constants” in the cosmological equations.
Quantum Optimal Control of Rovibrational Excitations of a Diatomic Alkali Halide: One-Photon vs. Two-Photon Processes
Authors: Kurosaki Yuzuru , Yokoyama Keiichi
Published: May 2019

We investigated the roles of one-photon and two-photon processes in the laser-controlled rovibrational transitions of the diatomic alkali halide, 7Li37Cl. Optimal control theory calculations were carried out using the Hamiltonian, including both the one-photon and two-photon field-molecule interaction terms. Time-dependent wave packet propagation was performed with both the radial and angular motions being treated quantum mechanically. The targeted processes were pure rotational and vibrational–rotational excitations: (v = 0, J = 0) → (v = 0, J = 2); (v = 0, J = 0) → (v = 1, J = 2). Total time of the control pulse was set to 2,000,000 atomic units (48.4 ps). In each control excitation process, weak and strong optimal fields were obtained by means of giving weak and strong field amplitudes, respectively, to the initial guess for the optimal field. It was found that when the field is weak, the control mechanism is dominated exclusively by a one-photon process, as expected, in both the targeted processes. When the field is strong, we obtained two kinds of optimal fields, one causing two-photon absorption and the other causing a Raman process. It was revealed, however, that the mechanisms for strong fields are not simply characterized by one process but rather by multiple one- and two-photon processes. It was also found that in the rotational excitation, (v = 0, J = 0) → (v = 0, J = 2), the roles of one- and two-photon processes are relatively distinct but in the vibrational–rotational excitation, (v = 0, J = 0) → (v = 1, J = 2), these roles are ambiguous and the cooperative effect associated with these two processes is quite large.
Immune System Stimulation by Oncolytic Rodent Protoparvoviruses
Authors: Angelova Assia , Rommelaere Jean
Published: May 2019

Rodent protoparvoviruses (PVs), parvovirus H-1 (H-1PV) in particular, are naturally endowed with oncolytic properties. While being historically described as agents that selectively replicate in and kill cancer cells, recent yet growing evidence demonstrates that these viruses are able to reverse tumor-driven immune suppression through induction of immunogenic tumor cell death, and the establishment of antitumorigenic, proinflammatory milieu within the tumor microenvironment. This review summarizes the most important preclinical proofs of the interplay and the cooperation between PVs and the host immune system. The molecular mechanisms of PV-induced immunostimulation are also discussed. Furthermore, initial encouraging in-human observations from clinical trials and compassionate virus uses are presented, and speak in favor of further H-1PV clinical development as partner drug in combined immunotherapeutic protocols.
Modeling of Mutational Events in the Evolution of Viruses
Authors: Ali Akhtar , Melcher Ulrich
Published: May 2019

Diverse studies of viral evolution have led to the recognition that the evolutionary rates of viral taxa observed are dependent on the time scale being investigated—with short-term studies giving fast substitution rates, and orders of magnitude lower rates for deep calibrations. Although each of these factors may contribute to this time dependent rate phenomenon, a more fundamental cause should be considered. We sought to test computationally whether the basic phenomena of virus evolution (mutation, replication, and selection) can explain the relationships between the evolutionary and phylogenetic distances. We tested, by computational inference, the hypothesis that the phylogenetic distances between the pairs of sequences are functions of the evolutionary path lengths between them. A Basic simulation revealed that the relationship between simulated genetic and mutational distances is non-linear, and can be consistent with different rates of nucleotide substitution at different depths of branches in phylogenetic trees.
Parsimonious Scenario for the Emergence of Viroid-Like Replicons De Novo
Authors: Catalán Pablo , Elena Santiago F. , Cuesta José A. , Manrubia Susanna
Published: May 2019

Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixed length, rod-like structures typical of Pospiviroidae are difficult to fix. Using different quantitative approaches, we evaluated the likelihood that RNA sequences fold into a rod-like structure and bear specific sequence motifs facilitating interactions with other molecules, e.g., RNA polymerases, RNases, and ligases. By means of numerical simulations, we show that circular RNA replicons analogous to Pospiviroidae emerge if evolution is seeded with minimal circular RNAs that grow through the gradual addition of nucleotides. Further, these rod-like replicons often maintain their structure if independent functional modules are acquired that impose selective constraints. The evolutionary scenario we propose here is consistent with the structural and biochemical properties of viroids described to date.
The Influence of Temperature on the Bulk Settling of Cohesive Sediment in Still Water with the Lattice Boltzmann Method
Authors: Qiao Guang-quan , Zhang Jin-feng , Zhang Qing-he , Feng Xi , Lu Yong-chang , Feng Wei-bing
Published: May 2019

Flocculation is very common and significant for cohesive sediment in coastal areas, and the influence of temperature on it cannot be neglected. The Lattice Boltzmann Method (LBM), combined with the extended Derjaguin‒Landau‒Verwey‒Overbeek (XDLVO) theory, which considers the micro-interaction forces between particles, was applied to simulate the settling and flocculation processes of cohesive sediment under various temperature conditions. The floc size, floc volume, suspended sediment concentration (SSC), and settling velocities were analyzed. The analyses revealed that with increasing temperature, both the mean floc diameter and floc volume grew, while the maximum floc diameter initially increased and then slightly decreased with its peak at 10 °C. During settling, the SSC change rate was exponentially related to the SSC, with an optimal fitting index of 0.3. The LBM sediment settling velocity was also compared with some formulas and physical model tests; the comparison results consistently demonstrated that the LBM was reasonable for modeling the bulk settling of cohesive sediment. Further discussions illustrated that the cohesive sediment is more difficult to flocculate at low temperatures due to the low aggregation frequency, while at high temperatures, some large flocs broke easily due to the effect of the short-distance force and macro force.
Hydrogeochemical Characteristics and Controlling Factors of the Lhasa River under the Influence of Anthropogenic Activities
Authors: Qin Huanhuan , Gao Bai , He Liu , Hu Xiaohong , Dong Lei , Sanjay Dhawan , Dong Andre , Sun Zhanxue , Wan Wei
Published: May 2019

Anthropogenic activities have had diversiform impacts on the surrounding river and environments. A study on the surface water of the Lhasa River Basin was undertaken to assess its hydrogeochemical characteristics under the influence of anthropogenic activities. A total of 16 samples collected from the Lhasa River were analyzed for pH, electric conductivity (EC), oxidation-reduction potential (ORP), total dissolved solids (TDS), major cations (K+, Na+, Ca2+, and Mg2+), major anions (Cl−, SO42−, HCO3−, and NO3−), and trace metals. The pH of the analyzed water samples varied from 6.40 to 9.10, indicating alkaline in nature. The EC values varied from 77.3 to 213 μs/cm while the TDS values varied from 73.37 to 217.55 mg/L. HCO3− and SO42− are the dominant anions while Ca2+ and Na+ are the dominant cations in the river water. The concentration of alkaline earth metals (Ca2+ + Mg2+) exceed the alkali metals (Na+ + K+) and HCO3− dominates over SO42− + Cl− concentrations in the majority of the surface water samples. Ca2+-Mg2+-HCO3− and Ca2+-Mg2+-Cl− are the dominant hydrogeochemical facies in the surface water of the area. The water chemistry is mainly controlled by rock weathering with secondary contribution from anthropogenic sources. The content of trace elements in the Lhasa River is low, basically at the natural background value. The high content of individual elements is mainly due to the mineral resource exploitation and geothermal resources in the basin. Countermeasures and attention should be payed to these aspects, such as the construction of water conservancy facilities, urban economic development, the development of mining activities, and sewage and wastewater discharge, so as to protect the water quality and sustainable development of the Lhasa River Basin.
Assessment of Climate Change Impact on Future Groundwater-Level Behavior Using SWAT Groundwater-Consumption Function in Geum River Basin of South Korea
Authors: Lee Jiwan , Jung Chunggil , Kim Sehoon , Kim Seongjoon
Published: May 2019

This study was to evaluate the groundwater-level behavior in Geum River Basin (9645.5 km2) of South Korea with HadGEM3-RA RCP 4.5 and 8.5 climate change scenarios and future groundwater use data using the soil and water assessment tool (SWAT). Before evaluating future groundwater behavior, the SWAT model was calibrated and validated using the daily inflows and storage of two dams (DCD and YDD) in the basin for 11 years (2005–2015), the daily groundwater-level observation data at five locations (JSJS, OCCS, BEMR, CASS, and BYBY), and the daily inflow and storage of three weir locations (SJW, GJW, and BJW) for three years and five months (August 2012 to December 2015). The Nash–Sutcliffe efficiency (NSE) and the coefficient of determination (R2) of two dam inflows was 0.55–0.70 and 0.67–0.75. For the inflows of the three weirs, NSE was 0.57–0.77 and R2 was 0.62–0.81. The average R2 value for the groundwater levels of the five locations ranged from 0.53 to 0.61. After verifying the SWAT for hydrologic components, we evaluated the behavior of future groundwater levels by future climate change scenarios and estimated future ground water use by Korean water vision 2020 based on ground water use monitoring data. The future groundwater-level decreased by −13.0, −5.0, and −9.0 cm at three upstream locations (JSJS, OCCS, and BEMR) among the five groundwater-level observation locations and increased by +3.0 and +1.0 cm at two downstream locations (CASS and BYBY). The future groundwater level was directly affected by the groundwater recharge, which was dependent on the seasonal and spatial precipitations in the basin.