bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward Zero-Emission Hybrid AC/DC Power Systems with Renewable Energy Sources and Storages: A Case Study from Lake Baikal Region
Authors: Sidorov Denis , Panasetsky Daniil , Tomin Nikita , Karamov Dmitriy , Zhukov Aleksei , Muftahov Ildar , Dreglea Aliona , Liu Fang , Li Yong
Published: March 2020

Tourism development in ecologically vulnerable areas like the lake Baikal region in Eastern Siberia is a challenging problem. To this end, the dynamical models of AC/DC hybrid isolated power system consisting of four power grids with renewable generation units and energy storage systems are proposed using the advanced methods based on deep reinforcement learning and integral equations. First, the wind and solar irradiance potential of several sites on the lake Baikal’s banks is analyzed as well as the electric load as a function of the climatic conditions. The optimal selection of the energy storage system components is supported in online mode. The approach is justified using the retrospective meteorological datasets. Such a formulation will allow us to develop a number of valuable recommendations related to the optimal control of several autonomous AC/DC hybrid power systems with different structures, equipment composition and kind of AC or DC current. Developed approach provides the valuable information at different stages of AC/DC hybrid power systems projects development with stand-alone hybrid solar-wind power generation systems.
Finite Element and Experimental Analysis of an Axisymmetric Electromechanical Converter with a Magnetostrictive Rod
Authors: Stachowiak Dorota , Demenko Andrzej
Published: March 2020

The paper presents the numerical and experimental investigations of the axisymmetric magnetostrictive actuator with a Terfenol-D rod. The applied model consists of equations that describe the magnetic and mechanical displacement fields. The equations of both fields are coupled through a nonlinear magneto-mechanical constitutive law. The model is considered as 2D axisymmetric. The finite element method is used to solve the field equations. Special attention is paid to the proper definition of magneto-mechanical relations. These relations are formed from measurements. A unique test stand is designed for the experimental investigation. The selected results of the simulation are compared with the measurement results. The comparison shows that the applied numerical model is sufficiently accurate.
PSO-Based Oscillatory Stability Assessment by Using the Torque Coefficients for SMIB
Authors: Mohamed Kamari Nor Azwan , Musirin Ismail , Dagang Ahmad Nazri , Mohd Zaman Mohd Hairi
Published: March 2020

This study discusses the evaluation of oscillatory stability based on the synchronizing K s and damping K d torque coefficients for a single-machine system connected to an infinite bus (SMIB). Particle swarm optimization (PSO) technique is used to determine K s and K d values and subsequently identify the oscillatory stability conditions in the SMIB. The ability of PSO is compared with those of evolutionary programming (EP) techniques and artificial immune system (AIS). The least square (LS) method is selected as the benchmark for K s and K d values determined by PSO, EP, and AIS. Simulation results show that PSO successfully estimated K s and K d values closest to LS compared with EP and AIS. PSO also uses lower computational time compared with those of the two other techniques. The proposed technique is suitable for solving oscillatory stability problems based on the determination of eigenvalues and minimum damping ratio.
A Moving Bed Reactor for Thermochemical Energy Storage Based on Metal Oxides
Authors: Preisner Nicole Carina , Linder Marc
Published: March 2020

High-temperature thermal energy storage enables concentrated solar power plants to provide base load. Thermochemical energy storage is based on reversible gas–solid reactions and brings along the advantage of potential loss-free energy storage in the form of separated reaction products and possible high energy densities. The redox reaction of metal oxides is able to store thermal energy at elevated temperatures with air providing the gaseous reaction partner. However, due to the high temperature level, it is crucial to extract both the inherent sensible and thermochemical energies of the metal-oxide particles for enhanced system efficiency. So far, experimental research in the field of thermochemical energy storage focused mainly on solar receivers for continuously charging metal oxides. A continuously operated system of energy storage and solar tower decouples the storage capacity from generated power with metal-oxide particles applied as heat transfer medium and energy storage material. Hence, a heat exchanger based on a countercurrent moving bed concept was developed in a kW -scale. The reactor addresses the combined utilization of the reaction enthalpy of the oxidation and the extraction of thermal energy of a manganese–iron-oxide particle flow. A stationary temperature profile of the bulk was achieved with two distinct temperature sections. The oxidation induced a nearly isothermal section with an overall stable off-gas temperature. The oxidation and heat extraction from the manganese–iron oxide resulted in a total energy density of 569 kJ/kg with a thermochemical share of 21.1%.
Flow Allocation in Meshed AC-DC Electricity Grids
Authors: Hofmann Fabian , Schlott Markus , Kies Alexander , Stöcker Horst
Published: March 2020

In power systems, flow allocation (FA) methods enable to allocate the usage and costs of the transmission grid to each single market participant. Based on predefined assumptions, the power flow is split into isolated generator-specific or producer-specific sub-flows. Two prominent FA methods, Marginal Participation (MP) and Equivalent Bilateral Exchanges (EBEs), build upon the linearized power flow and thus on the Power Transfer Distribution Factors (PTDFs). Despite their intuitive and computationally efficient concepts, they are restricted to networks with passive transmission elements only. As soon as a significant number of controllable transmission elements, such as high-voltage direct current (HVDC) lines, operate in the system, they lose their applicability. This work reformulates the two methods in terms of Virtual Injection Patterns (VIPs), which allows one to efficiently introduce a shift parameter q to tune contributions of net sources and net sinks in the network. In this work, major properties and differences in the methods are pointed out, and it is shown how the MP and EBE algorithms can be applied to generic meshed AC-DC electricity grids: by introducing a pseudo-impedance ω ¯ , which reflects the operational state of controllable elements and allows one to extend the PTDF matrix under the assumption of knowing the current flow in the system. Basic properties from graph theory are used to solve for the pseudo-impedance in dependence of the position within the network. This directly enables, e.g., HVDC lines to be considered in the MP and EBE algorithms. The extended methods are applied to a low-carbon European network model (PyPSA-EUR) with a spatial resolution of 181 nodes and an 18% transmission expansion compared to today’s total transmission capacity volume. The allocations of MP and EBE show that countries with high wind potentials profit most from the transmission grid expansion. Based on the average usage of transmission system expansion, a method of distributing operational and capital expenditures is proposed. In addition, it is shown how injections from renewable resources strongly drive country-to-country allocations and thus cross-border electricity flows.
Study of a Bidirectional Power Converter Integrated with Battery/Ultracapacitor Dual-Energy Storage
Authors: Lai Ching-Ming , Teh Jiashen , Lin Yuan-Chih , Liu Yitao
Published: March 2020

A patented bidirectional power converter was studied as an interface to connect the DC-bus of driving inverter, battery energy storage (BES), and ultracapacitor (UC) to solve the problem that the driving motor damages the battery life during acceleration and deceleration in electric vehicles (EVs). The proposed concept was to adopt a multiport switch to control the power flow and achieve the different operating mode transitions for the better utilization of energy. In addition, in order to improve the conversion efficiency, the proposed converter used a coupled inductor and interleaved-pulse-width-modulation (IPWM) control to achieve a high voltage conversion ratio (i.e., bidirectional high step-up/down conversion characteristics). This study discussed the steady-state operation and characteristic analysis of the proposed converter. Finally, a 500 W power converter prototype with specifications of 72 V DC-bus, 24 V BES, and 48 V UC was built, and the feasibility was verified by simulation and experiment results. The highest efficiency points of the realized prototype were 97.4%, 95.5%, 97.2%, 97.1%, and 95.3% for the UC charge, battery charge, UC discharge, the dual-energy in series discharge, and battery discharge modes, respectively.
Energy Utilization of Spent Coffee Grounds in the Form of Pellets
Authors: Nosek Radovan , Tun Maw Maw , Juchelkova Dagmar
Published: March 2020

Nowadays it is important to limit the use and combustion of fossil fuels such as oil and coal. There is a need to create environmentally acceptable projects that can reduce or even stop greenhouse gas emissions. In this article, we dealt with the objectives of energy policy with regard to environmental protection, waste utilization, and conservation of natural resources. The main objective of the research was to assess the possibility of the use of spent coffee grounds (SCG) as fuel. As a part of the solution, the processing of coffee waste in the form of pellets, analysis of calorific value and combustion in the boiler were proposed. The experiments were done with four samples of pellets. These samples were made from a mixture of wood sawdust and spent coffee grounds with ratio 30:70 (wood sawdust: spent coffee grounds), 40:60, 50:50 and 100% of spent coffee grounds. The calorific values were compared with wood sawdust pellets (17.15 MJ.kg−1) and the best lower calorific value of 21.08 MJ.kg−1 was measured for 100% of spent coffee grounds. This sample did not achieve the desired performance during the combustion in the boiler due to the low strength of the sample.
Study on a Dynamic Numerical Model of an Underground Air Tunnel System for Cooling Applications—Experimental Validation and Multidimensional Parametrical Analysis
Authors: Tang Liang , Liu Zhengxuan , Zhou Yuekuan , Qin Di , Zhang Guoqiang
Published: March 2020

The underground air tunnel system shows promising potentials for reducing energy consumption of buildings and for improving indoor thermal comfort, whereas the existing dynamic models using the computational fluid dynamic (CFD) method show computational complexity and are user-unfriendly for parametrical analysis. In this study, a dynamic numerical model was developed with the on-site experimental calibration. Compared to the traditional CFD method with high computational complexity, the mathematical model on the MATLAB/SIMULINK platform is time-saving in terms of the real-time thermal performance prediction. The experimental validation results indicated that the maximum absolute relative deviation was 3.18% between the model-driven results and the data from the on-site experiments. Parametrical analysis results indicated that, with the increase of the tube length, the outlet temperature decreases with an increase of the cooling capacity whereas the increasing/decreasing magnitude slows down. In addition, the system performance is independent on the tube materials. Furthermore, the outlet air temperature and cooling capacity are dependent on the tube diameter and air velocity, i.e., a larger tube diameter and a higher air velocity are more suitable to improve the system’s cooling capacity, and a smaller tube diameter and a lower air velocity will produce a more stable and lower outlet temperature. Further studies need to be conducted for the trade-off solutions between air velocity and tube diameter for the bi-criteria performance enhancement between outlet temperature and cooling capacity. This study proposed an experimentally validated mathematical model to accurately predict the thermal performance of the underground air tunnel system with high computational efficiency, which can provide technical guidance to multi-combined solutions through geometrical designs and operating parameters for the optimal design and robust operation.
Study on Polymer Electrolyte Fuel Cells with Nonhumidification Using Metal Foam in Dead-Ended Operation
Authors: Kim Myo-Eun , Sohn Young-Jun
Published: March 2020

Portable power sources have attracted increasing interest and attention, with a focus on the reduction of the system volume. Thus, portable power sources often use polymer electrolyte fuel cell (PEFC) systems with dead-ended operation—which are simpler and more fuel-efficient than conventional PEFC systems. In these systems, the fuel may be supplied under nonhumidified conditions to minimize the balance of plant (BOP). In recent studies, metal foams have been used as flow fields to improve fuel diffusion and water management in the PEFC; the performance can be compared to that of a conventional channel. This study compared the performance and water management ability of channel and metal foam flow fields under nonhumidified conditions with dead-ended operation. The results demonstrate that the average output was similar for both flow fields. In terms of fuel efficiency, the PEFC with the metal foam could be operated for a significantly longer time without purging than that with the channel.
Improved Hydrogen-Production-Based Power Management Control of a Wind Turbine Conversion System Coupled with Multistack Proton Exchange Membrane Electrolyzers
Authors: Guilbert Damien , Vitale Gianpaolo
Published: March 2020

This paper deals with two main issues regarding the specific energy consumption in an electrolyzer (i.e., the Faraday efficiency and the converter topology). The first aspect is addressed using a multistack configuration of proton exchange membrane (PEM) electrolyzers supplied by a wind turbine conversion system (WTCS). This approach is based on the modeling of the wind turbine and the electrolyzers. The WTCS and the electrolyzers are interfaced through a stacked interleaved DC–DC buck converter (SIBC), due to its benefits for this application in terms of the output current ripple and reliability. This converter is controlled so that it can offer dynamic behavior that is faster than the wind turbine, avoiding overvoltage during transients, which could damage the PEM electrolyzers. The SIBC is designed to be connected in array configuration (i.e., parallel architecture), so that each converter operates at its maximum efficiency. To assess the performance of the power management strategy, experimental tests were carried out. The reported results demonstrate the correct behavior of the system during transient operation.
Study of the Improvement on Energy Efficiency for a Building in the Mediterranean Area by the Installation of a Green Roof System
Authors: Peñalvo-López Elisa , Cárcel-Carrasco Javier , Alfonso-Solar David , Valencia-Salazar Iván , Hurtado-Pérez Elias
Published: March 2020

Rooftop gardens ona building have proved to be a good way to improve its storm water management, but many other benefits can be obtained from the installation of these systems, such as reduction of energy consumption, decrease of the heat stress, abatement on CO2 emissions, etc. In this paper, the effect from the presence of these rooftop gardens on abuilding’s energy consumption has been investigated by experimental campaigns using a green roof ona public building in a Mediterranean location in Spain. The obtained results demonstrate a substantial improvement by the installation of the green roof onthe building’s cooling energy demand for a standard summer day, in the order of 30%, and a reduction, about 15%, in the heating energy demand for a winter day. Thus, given the longer duration of the summer conditions along the year, a noticeable reduction on energy demand could be obtained. Simulation analysis, using commercial software TRNSYS code, previously calibrated using experimental data for typical summer and winter days, allows for the extrapolation to the entire year of these results deducing noticeable improvement in energy efficiency, in the order of 19%, but with an increase of 6% in the peak power during the winter period.
An Ultrasonic Longitudinal Through-Transmission Method to Measure the Compressive Internal Stress in Epoxy Composite Specimens of Gas-Insulated Metal-Enclosed Switchgear
Authors: Zou Zhouyiao , Hao Yanpeng , Tian Fangyuan , Zheng Yao , He Weiming , Yang Lin , Li Licheng
Published: March 2020

Situations of internal stress in basin insulators inside gas-insulated metal-enclosed switchgear (GIS) can lead to cracks, which can influence the safety and stability of apparatus. However, there is currently no research on internal stress measurements for composites of GIS basin insulators, and only measurements for surface stress. In this paper, an internal stress measurement method for GIS epoxy composite is proposed using an ultrasonic longitudinal through-transmission technique based on the acoustoelastic effect. An internal stress measurement system is developed to investigate the relationship between the uniaxial compressive internal stress and the velocity of the ultrasonic wave vertical to the stress in epoxy composite within a range of 0–70 MPa, and to calculate the acoustoelastic coefficient of epoxy composite. The effects of system delay are eliminated in measuring the propagation time. Some epoxy composite cuboid specimens with similar materials and using a manufacturing process similar to those of 252 kV GIS basin insulators are synthesized, and the uniformity of the internal stress in cuboid specimens is verified by finite element simulation. The results reveal a linear increase of the ultrasonic longitudinal wave velocity with increasing stress. It has been shown that the average acoustoelastic coefficient of GIS epoxy composites, using the longitudinal waves vertical to the stress, is 4.556 × 10−5/MPa. Additionally, the absolute errors of the internal stress measurements are less than 12.397 MPa. This research shows that the ultrasonic method based on the acoustoelastic effect for measuring the internal stress in GIS epoxy composites is feasible.
Assessing the Use of Reinforcement Learning for Integrated Voltage/Frequency Control in AC Microgrids
Authors: Younesi Abdollah , Shayeghi Hossein , Siano Pierluigi
Published: March 2020

The main purpose of this paper is to present a novel algorithmic reinforcement learning (RL) method for damping the voltage and frequency oscillations in a micro-grid (MG) with penetration of wind turbine generators (WTG). First, the continuous-time environment of the system is discretized to a definite number of states to form the Markov decision process (MDP). To solve the modeled discrete RL-based problem, Q-learning method, which is a model-free and simple iterative solution mechanism is used. Therefore, the presented control strategy is adaptive and it is suitable for the realistic power systems with high nonlinearities. The proposed adaptive RL controller has a supervisory nature that can improve the performance of any kind of controllers by adding an offset signal to the output control signal of them. Here, a part of Denmark distribution system is considered and the dynamic performance of the suggested control mechanism is evaluated and compared with fuzzy-proportional integral derivative (PID) and classical PID controllers. Simulations are carried out in two realistic and challenging scenarios considering system parameters changing. Results indicate that the proposed control strategy has an excellent dynamic response compared to fuzzy-PID and traditional PID controllers for damping the voltage and frequency oscillations.
Semi-Analytical Modeling and Analysis of Halbach Array
Authors: Sim Min-Seob , Ro Jong-Suk
Published: March 2020

Analysis of Halbach array placed in open space by using finite element method involves substantial consumption of memory, time, and cost. To address this problem, development of a mathematical modeling and analytic analysis method for Halbach array can be a solution, but research on this topic is currently insufficient. Therefore, a novel mathematical modeling and analytic analysis method for Halbach array in open space is proposed in this study, which is termed as the Ampere model and the Biot–Savart law (AB method). The proposed AB method can analyze the Halbach array rapidly and accurately with minimal consumption of memory. The usefulness of the AB method in terms of accuracy and memory and time consumption is verified by comparing the AB method with finite element method in this paper.
Maximum Power Point Tracking Technology of Photovoltaic Array under Partial Shading Based On Adaptive Improved Differential Evolution Algorithm
Authors: Zhang Peng , Sui Huibin
Published: March 2020

In the case of partial shading conditions, there will be more than one maximum power point (MPP) in photovoltaic (PV) array. The traditional maximum power point tracking (MPPT) methods are easy to get in the local maximum power point (LMPP) and fail. Based on the standard differential evolution (DE) algorithm, the mutation strategy, scaling factor F, and cross factor CR of the algorithm are optimized. Also, the population position variance δ 2 is used to prevent falling into LMPP. Finally, the conditions for algorithm termination and restart are set. It is verified by simulation that the method has fast convergence speed, high accuracy, and can adapt well to changes in the external environment. The improved DE algorithm has a great advantage in MPPT.
LPWAN Technologies: Emerging Application Characteristics, Requirements, and Design Considerations
Authors: Chaudhari Bharat S. , Zennaro Marco , Borkar Suresh
Published: March 2020

Low power wide area network (LPWAN) is a promising solution for long range and low power Internet of Things (IoT) and machine to machine (M2M) communication applications. This paper focuses on defining a systematic and powerful approach of identifying the key characteristics of such applications, translating them into explicit requirements, and then deriving the associated design considerations. LPWANs are resource-constrained networks and are primarily characterized by long battery life operation, extended coverage, high capacity, and low device and deployment costs. These characteristics translate into a key set of requirements including M2M traffic management, massive capacity, energy efficiency, low power operations, extended coverage, security, and interworking. The set of corresponding design considerations is identified in terms of two categories, desired or expected ones and enhanced ones, which reflect the wide range of characteristics associated with LPWAN-based applications. Prominent design constructs include admission and user traffic management, interference management, energy saving modes of operation, lightweight media access control (MAC) protocols, accurate location identification, security coverage techniques, and flexible software re-configurability. Topological and architectural options for interconnecting LPWAN entities are discussed. The major proprietary and standards-based LPWAN technology solutions available in the marketplace are presented. These include Sigfox, LoRaWAN, Narrowband IoT (NB-IoT), and long term evolution (LTE)-M, among others. The relevance of upcoming cellular 5G technology and its complementary relationship with LPWAN technology are also discussed.
Impact of Processing and Intestinal Conditions on in Vitro Digestion of Chia (Salvia hispanica) Seeds and Derivatives
Authors: Calvo-Lerma Joaquim , Paz-Yépez Carolina , Asensio-Grau Andrea , Heredia Ana , Andrés Ana
Published: March 2020

Chia seeds present with an excellent nutrient profile, including polyunsaturated fat, protein, fibre and bioactive compounds, which make them a potential food or ingredient to bring beneficial health effects. However, their tough structure could mean that these seeds remain hardly disrupted during digestion, thus preventing the release and digestibility of nutrients. In the present study, different chia products (seeds, whole flour, partially defatted flour and sprouts) were assessed in terms of proteolysis, lipolysis, calcium and polyphenols bioaccessibility and antioxidant activity. In vitro digestions were performed supporting standard intestinal (pH 7, bile salts concentration 10 mM) and altered (pH 6, bile salts concentration 1 mM) conditions. The altered conditions significantly reduced lipolysis, but not proteolysis. Regarding the food matrix, compared to the chia seeds, whole and partially defatted flour increased the hydrolysis of lipids and protein, relating to reduced particle size. Sprouting had an enhancing effect on proteolysis but prevented lipolysis. Calcium bioaccessibility dropped in all the samples in the two intestinal conditions. The digestion process led to increased polyphenols bioaccessibility in all the structures, but reduced antioxidant activity except in the milled structures. In conclusion, milling should be applied to chia seeds prior to consumption in cases where enhancing the potential uptake of macro and micronutrients is targeted, and sprouting is suitable to enhance protein digestibility and reduce lipolysis.
A Review of the Methodology of Analyzing Aflatoxin and Fumonisin in Single Corn Kernels and the Potential Impacts of These Methods on Food Security
Authors: Chavez Ruben A. , Cheng Xianbin , Stasiewicz Matthew J.
Published: March 2020

Current detection methods for contamination of aflatoxin and fumonisin used in the corn industry are based on bulk level. However, literature demonstrates that contamination of these mycotoxins is highly skewed and bulk samples do not always represent accurately the overall contamination in a batch of corn. Single kernel analysis can provide an insightful level of analysis of the contamination of aflatoxin and fumonisin, as well as suggest a possible remediation to the skewness present in bulk detection. Current literature describes analytical methods capable of detecting aflatoxin and fumonisin at a single kernel level, such as liquid chromatography, fluorescence imaging, and reflectance imaging. These methods could provide tools to classify mycotoxin contaminated kernels and study potential co-occurrence of aflatoxin and fumonisin. Analysis at a single kernel level could provide a solution to the skewness present in mycotoxin contamination detection and offer improved remediation methods through sorting that could impact food security and management of food waste.
Seascape Genetics and the Spatial Ecology of Juvenile Green Turtles
Authors: Jensen Michael P. , Dalleau Mayeul , Gaspar Philippe , Lalire Maxime , Jean Claire , Ciccione Stéphane , Mortimer Jeanne A. , Quillard Mireille , Taquet Coralie , Wamukota Andrew , Leroux Géraud , Bourjea Jérôme
Published: March 2020

Understanding how ocean currents impact the distribution and connectivity of marine species, provides vital information for the effective conservation management of migratory marine animals. Here, we used a combination of molecular genetics and ocean drift simulations to investigate the spatial ecology of juvenile green turtle (Chelonia mydas) developmental habitats, and assess the role of ocean currents in driving the dispersal of green turtle hatchlings. We analyzed mitochondrial (mt)DNA sequenced from 358 juvenile green turtles, and from eight developmental areas located throughout the Southwest Indian Ocean (SWIO). A mixed stock analysis (MSA) was applied to estimate the level of connectivity between developmental sites and published genetic data from 38 known genetic stocks. The MSA showed that the juvenile turtles at all sites originated almost exclusively from the three known SWIO stocks, with a clear shift in stock contributions between sites in the South and Central Areas. The results from the genetic analysis could largely be explained by regional current patterns, as shown by the results of passive numerical drift simulations linking breeding sites to developmental areas utilized by juvenile green turtles. Integrating genetic and oceanographic data helps researchers to better understand how marine species interact with ocean currents at different stages of their lifecycle, and provides the scientific basis for effective conservation management.
Mapping-by-Sequencing via MutMap Identifies a Mutation in ZmCLE7 Underlying Fasciation in a Newly Developed EMS Mutant Population in an Elite Tropical Maize Inbred
Authors: Tran Quan Hong , Bui Ngoc Hong , Kappel Christian , Dau Nga Thi Ngoc , Nguyen Loan Thi , Tran Thuy Thi , Khanh Tran Dang , Trung Khuat Huu , Lenhard Michael , Vi Son Lang
Published: March 2020

Induced point mutations are important genetic resources for their ability to create hypo- and hypermorphic alleles that are useful for understanding gene functions and breeding. However, such mutant populations have only been developed for a few temperate maize varieties, mainly B73 and W22, yet no tropical maize inbred lines have been mutagenized and made available to the public to date. We developed a novel Ethyl Methanesulfonate (EMS) induced mutation resource in maize comprising 2050 independent M2 mutant families in the elite tropical maize inbred ML10. By phenotypic screening, we showed that this population is of comparable quality with other mutagenized populations in maize. To illustrate the usefulness of this population for gene discovery, we performed rapid mapping-by-sequencing to clone a fasciated-ear mutant and identify a causal promoter deletion in ZmCLE7 (CLE7). Our mapping procedure does not require crossing to an unrelated parent, thus is suitable for mapping subtle traits and ones affected by heterosis. This first EMS population in tropical maize is expected to be very useful for the maize research community. Also, the EMS mutagenesis and rapid mapping-by-sequencing pipeline described here illustrate the power of performing forward genetics in diverse maize germplasms of choice, which can lead to novel gene discovery due to divergent genetic backgrounds.
Genetic Diversity, Population Structure and Linkage Disequilibrium Assessment among International Sunflower Breeding Collections
Authors: Filippi Carla V. , Merino Gabriela A. , Montecchia Juan F. , Aguirre Natalia C. , Rivarola Máximo , Naamati Guy , Fass Mónica I. , Álvarez Daniel , Di Rienzo Julio , Heinz Ruth A. , Contreras Moreira Bruno , Lia Verónica V. , Paniego Norma B.
Published: March 2020

Sunflower germplasm collections are valuable resources for broadening the genetic base of commercial hybrids and ameliorate the risk of climate events. Nowadays, the most studied worldwide sunflower pre-breeding collections belong to INTA (Argentina), INRA (France), and USDA-UBC (United States of America–Canada). In this work, we assess the amount and distribution of genetic diversity (GD) available within and between these collections to estimate the distribution pattern of global diversity. A mixed genotyping strategy was implemented, by combining proprietary genotyping-by-sequencing data with public whole-genome-sequencing data, to generate an integrative 11,834-common single nucleotide polymorphism matrix including the three breeding collections. In general, the GD estimates obtained were moderate. An analysis of molecular variance provided evidence of population structure between breeding collections. However, the optimal number of subpopulations, studied via discriminant analysis of principal components (K = 12), the bayesian STRUCTURE algorithm (K = 6) and distance-based methods (K = 9) remains unclear, since no single unifying characteristic is apparent for any of the inferred groups. Different overall patterns of linkage disequilibrium (LD) were observed across chromosomes, with Chr10, Chr17, Chr5, and Chr2 showing the highest LD. This work represents the largest and most comprehensive inter-breeding collection analysis of genomic diversity for cultivated sunflower conducted to date.
Subsoil Reconstruction in Geostatistics beyond Kriging: A Case Study in Veneto (NE Italy)
Authors: Fabbri Paolo , Gaetan Carlo , Sartore Luca , Dalla Libera Nico
Published: March 2020

The reconstruction of hydro-stratigraphic units in subsoil (a general term indicating all the materials below ground level) plays an important role in the assessment of soil heterogeneity, which is a keystone in groundwater flow and transport modeling. A geostatistical approach appears to be a good way to reconstruct subsoil, and now other methods besides the classical indicator (co)kriging are available as alternative approximations of the conditional probabilities. Some of these techniques take specifically into account categorical variables as lithologies, but they are computationally prohibitive. Moreover, the stage before subsoil prediction/simulation can be very informative from a hydro-stratigraphic point of view, as the detailed transiogram analysis of this paper demonstrates. In this context, an application of the spMC package for the R software is presented by using a test site located within the Venetian alluvial plain (NE Italy). First, a detailed transiogram analysis was conducted, and then a maximum entropy approach, based on transition probabilities, named Markovian-type Categorical Prediction (MCP), was applied to approximate the posterior conditional probabilities. The study highlights some advantages of the presented approach in term of hydrogeological knowledge and computational efficiency. The spMC package couples transiogram analysis with a maximum entropy approach by taking advantage of High-Performance Computing (HPC) techniques. These characteristics make the spMC package useful for simulating hydro-stratigraphic units in subsoil, despite the use of a large number of lithologies (categories). The results obtained by spMC package suggest that this software should be considered a good candidate for simulating subsoil lithological distributions, especially of limited areas.
Enable, Reconnect and Augment: A New ERA of Virtual Nature Research and Application
Authors: Litleskare Sigbjørn , E. MacIntyre Tadhg , Calogiuri Giovanna
Published: March 2020

Being exposed to natural environments is associated with improved health and well-being, as these environments are believed to promote feelings of “being away” from everyday struggles, positive emotional reactions and stress reduction. Despite these positive effects, humanity is becoming increasingly more distanced from nature due to societal changes, such as increased urbanization and the reduced accessibility of natural environments. Technology is also partly to blame, as research suggests that people replace nature contact with increased screen time. In this cross-section between nature and technology, we find technological nature which is progressing towards a point where we may be capable of simulating exposure to real nature. Concerns have been raised regarding this technology, as it is feared it will replace real nature. However, research suggests that virtual nature may have a more positive impact on society than a mere replacement of real nature, and this review propose several areas where virtual nature may be a beneficial addition to actual nature (Enable), help people reconnect with the real natural world (Reconnect) and “boost” human-nature interactions (Augment). Based on the current research and theoretical framework, this review proposes guidelines for future research within these areas, with the aim of advancing the field by producing high quality research.
The Toxic Effects of Sulfoxaflor Induced in Earthworms (Eisenia fetida) under Effective Concentrations
Authors: Zhang Xiaolian , Wang Xiuguo , Liu Yalei , Fang Kuan , Liu Tong
Published: March 2020

Sulfoxaflor is a new kind of neonicotinoid insecticide that is used to control sap-feeding insect pests. In this study, a hazard assessment of sulfoxaflor on soil invertebrate earthworms was performed under effective concentrations. The results showed that different exposure times and doses had significant influence on the toxicity of sulfoxaflor. Sulfoxaflor degraded quickly in artificial soil with a degradation rate of 0.002–0.017 mg/(kg·d) and a half-life of 12.0–15.4 d. At 0.5 mg/kg and 1.0 mg/kg, the ·OH− content, antioxidant enzyme activeities, thiobarbituric acid reactive substances (TBARS) content and 8-OHdG content had significant differences compared to those in the control group. On the 56th day, significant differences were only observed in the Glutathione S-transferase enzyme (GST) activity and 8-OHdG content at 1.0 mg/kg compared to those in the control group due to the degradation of sulfoxaflor. This indicated that the risk of sulfoxaflor to earthworms was reduced because it was easily degraded in soil. However, because sulfoxaflor is a super toxic pollutant to earthworms, high concentrations of sulfoxaflor should not be released into the soil environment.
The Mediating Role of the Patient Health Engagement Model on the Relationship Between Patient Perceived Autonomy Supportive Healthcare Climate and Health Literacy Skills
Authors: Barello Serena , Palamenghi Lorenzo , Graffigna Guendalina
Published: March 2020

Individuals with low health literacy (HL) are known to have poorer health outcomes and to have higher mortality rates compared to individuals with higher HL; hence, the improvement of HL is a key outcome in modern healthcare systems. Healthcare providers are therefore asked to support patients in becoming more and more engaged in their healthcare, thus augmenting their literacy skills. Our main hypothesis is that the well-known relationship between patients’ perceived autonomy supportive healthcare climate and HL skills is mediated by the Patient Health Engagement Model (PHE-model) which describes the patients’ progressive maturation of a psychological readiness to become active players in their healthcare. The purpose of this study was to formulate a hypothetical structural equation model (SEM) linking an autonomy-supportive healthcare climate to PHE-model and HL. A cross-sectional survey design was employed involving 1007 Italian chronic patients. The hypothetical model was tested using SEM to verify the hypothesized mediation of the PHE-model between autonomy-supportive healthcare climate and HL. Results show that the theoretical model has a good fit indexes and that PHE-model fully mediates the relationship between autonomy-supportive healthcare climate and HL. This finding suggests healthcare systems to implement a new paradigm where patients are supported to play an autonomous role in their own healthcare.
Applicability of a Recreational-Grade Interferometric Sonar for the Bathymetric Survey and Monitoring of the Drava River
Authors: Halmai Ákos , Gradwohl–Valkay Alexandra , Czigány Szabolcs , Ficsor Johanna , Liptay Zoltán Árpád , Kiss Kinga , Lóczy Dénes , Pirkhoffer Ervin
Published: March 2020

Sonar survey of shallow water bodies has challenged scientists for a long time. Although these water courses are small, still they have an increasing ecological, touristic and economical role. As maritime sonars are non-ideal tools for shallow waters, the bathymetric survey of these rivers has been taken with cross-sectional methods. Due to recent developments, interferometric surveying technology have also burst into the market of recreational-grade fish-finders. The objective of the current study was the development of a novel, complex and integrated surveying technique which is affordable, robust and applicable even at low water levels. A recreational-grade sonar system was assembled and mounted on a double-hull vessel and connected with a geodetic Global Navigation Satellite System (GNSS) device. We have developed a novel software which enables the bridging between a closed sonar file format and the commonly used Geographic Information System (GIS) datasets. As a result, the several month-long conventional bathymetric survey of the 146 km-long reach of the Drava River was reduced to 20 days and provided channel bathymetry of many orders of magnitude higher than the classical methods. Additionally, a large number of spatial derivatives were generated which enables the analysis of channel morphology, textural variation of channel sediments and the accurate delineation of navigational routes.
Mitochondrial Epigenetics: Non-Coding RNAs as a Novel Layer of Complexity
Authors: Cavalcante Giovanna C. , Magalhães Leandro , Ribeiro-dos-Santos Ândrea , Vidal Amanda F.
Published: March 2020

Mitochondria are organelles responsible for several functions involved in cellular balance, including energy generation and apoptosis. For decades now, it has been well-known that mitochondria have their own genetic material (mitochondrial DNA), which is different from nuclear DNA in many ways. More recently, studies indicated that, much like nuclear DNA, mitochondrial DNA is regulated by epigenetic factors, particularly DNA methylation and non-coding RNAs (ncRNAs). This field is now called mitoepigenetics. Additionally, it has also been established that nucleus and mitochondria are constantly communicating to each other to regulate different cellular pathways. However, little is known about the mechanisms underlying mitoepigenetics and nuclei–mitochondria communication, and also about the involvement of the ncRNAs in mitochondrial functions and related diseases. In this context, this review presents the state-of-the-art knowledge, focusing on ncRNAs as new players in mitoepigenetic regulation and discussing future perspectives of these fields.
Curcumin as an Anticancer Agent in Malignant Mesothelioma: A Review
Authors: Baldi Alfonso , De Luca Antonio , Maiorano Patrizia , D’Angelo Costantino , Giordano Antonio
Published: March 2020

Malignant mesothelioma is an infrequent tumor that initiates from the mesothelial cells lining of body cavities. The great majority of mesotheliomas originate in the pleural cavity, while the remaining cases initiate in the peritoneal cavity, in the pericardial cavity or on the tunica vaginalis. Usually, mesotheliomas grow in a diffuse pattern and tend to enclose and compress the organs in the various body cavities. Mesothelioma incidence is increasing worldwide and still today, the prognosis is very poor, with a reported median survival of approximately one year from presentation. Thus, the development of alternative and more effective therapies is currently an urgent requirement. The aim of this review article was to describe recent findings about the anti-cancer activity of curcumin and some of its derivatives on mesotheliomas. The potential clinical implications of these findings are discussed.
Does the Pre-Ovulatory Pig Oviduct Rule Sperm Capacitation In Vivo Mediating Transcriptomics of Catsper Channels?
Authors: Martinez Cristina A. , Alvarez-Rodriguez Manuel , Wright Dominic , Rodriguez-Martinez Heriberto
Published: March 2020

Spermatozoa need to conduct a series of biochemical changes termed capacitation in order to fertilize. In vivo, capacitation is sequentially achieved during sperm transport and interaction with the female genital tract, by mechanisms yet undisclosed in detail. However, when boar spermatozoa are stored in the tubal reservoir pre-ovulation, most appear to be in a non-capacitated state. This study aimed at deciphering the transcriptomics of capacitation-related genes in the pig pre-ovulatory oviduct, following the entry of semen or of sperm-free seminal plasma (SP). Ex-vivo samples of the utero-tubal junction (UTJ) and isthmus were examined with a microarray chip (GeneChip® Porcine Gene 1.0 ST Array, Thermo Fisher Scientific) followed by bioinformatics for enriched analysis of functional categories (GO terms) and restrictive statistics. The results confirmed that entry of semen or of relative amounts of sperm-free SP modifies gene expression of these segments, pre-ovulation. It further shows that enriched genes are differentially associated with pathways relating to sperm motility, acrosome reaction, single fertilization, and the regulation of signal transduction GO terms. In particular, the pre-ovulation oviduct stimulates the Catsper channels for sperm Ca2+ influx, with AKAPs, CATSPERs, and CABYR genes being positive regulators while PKIs and CRISP1 genes appear to be inhibitors of the process. We postulate that the stimulation of PKIs and CRISP1 genes in the pre-ovulation sperm reservoir/adjacent isthmus, mediated by SP, act to prevent premature massive capacitation prior to ovulation.
Sulfonamide Inhibition Studies of an α-Carbonic Anhydrase from Schistosoma mansoni, a Platyhelminth Parasite Responsible for Schistosomiasis
Authors: Angeli Andrea , Pinteala Mariana , Maier Stelian S. , Simionescu Bogdan C. , Da’dara Akram A. , Skelly Patrick J. , Supuran Claudiu T.
Published: March 2020

Schistosomiasis is a debilitating infection provoked by parasitic flatworms called schistosomes. The species Schistosoma mansoni is endemic in Africa, where it causes intestinal schistosomiasis. Recently, an α-carbonic anhydrase (CA, EC 4.2.1.1) was cloned and characterized from this organism and designated as SmCA. The protein is expressed in the tegument (skin) of S. mansoni at the host–parasite interface. Recombinant SmCA possesses high catalytic activity in the CO2 hydration reaction, similar to that of human CA isoform II with a kcat of 1.2 × 106 s−1 and a kcat/KM of 1.3 × 108 M−1·s−1. It has been found that schistosomes whose SmCA gene is suppressed using RNA interference are unable to establish a robust infection in mice, suggesting that the chemicals that inhibit SmCA function should have the same debilitating effect on the parasites. In this study, a collection of aromatic/heterocyclic sulfonamides were investigated as possible SmCA inhibitors. Several sulfonamides inhibited SmCA with medium to weak potency (KI values of 737.2 nM−9.25 μM), whereas some heterocyclic compounds inhibited the enzyme with KI values in the range of 124−325 nM. The α-CA from S. mansoni, SmCA, is proposed as a new anti-schistosomiasis drug target.
Clinical Significance of Cytoplasmic IgE-Positive Mast Cells in Eosinophilic Chronic Rhinosinusitis
Authors: Gion Yuka , Okano Mitsuhiro , Koyama Takahisa , Oura Tokie , Nishikori Asami , Orita Yorihisa , Tachibana Tomoyasu , Marunaka Hidenori , Makino Takuma , Nishizaki Kazunori , Sato Yasuharu
Published: March 2020

Cross-linking of antigen-specific IgE bound to the high-affinity IgE receptor (FcεRI) on the surface of mast cells with multivalent antigens results in the release of mediators and development of type 2 inflammation. FcεRI expression and IgE synthesis are, therefore, critical for type 2 inflammatory disease development. In an attempt to clarify the relationship between eosinophilic chronic rhinosinusitis (ECRS) and mast cell infiltration, we analyzed mast cell infiltration at lesion sites and determined its clinical significance. Mast cells are positive for c-kit, and IgE in uncinated tissues (UT) and nasal polyps (NP) were examined by immunohistochemistry. The number of positive cells and clinicopathological factors were analyzed. Patients with ECRS exhibited high levels of total IgE serum levels and elevated peripheral blood eosinophil ratios. As a result, the number of mast cells with membranes positive for c-kit and IgE increased significantly in lesions forming NP. Therefore, we classified IgE-positive mast cells into two groups: membrane IgE-positive cells and cytoplasmic IgE-positive cells. The amount of membrane IgE-positive mast cells was significantly increased in moderate ECRS. A positive correlation was found between the membrane IgE-positive cells and the radiological severity score, the ratio of eosinophils, and the total serum IgE level. The number of cytoplasmic IgE-positive mast cells was significantly increased in moderate and severe ECRS. A positive correlation was observed between the cytoplasmic IgE-positive cells and the radiological severity score, the ratio of eosinophils in the blood, and the total IgE level. These results suggest that the process of mast cell internalization of antigens via the IgE receptor is involved in ECRS pathogenesis.