bluuebunny/crossref_metadata_2025 huggingface dataset:
Savings and Investment Decisions in the Polish Energy Sector
Authors: Derkacz Arkadiusz J. , Dudziak Agnieszka
Published: January 2021

The paper presents the results of empirical studies of the energy sector in Poland in the period 2005–2020. The main research problem was the impact of gross savings of changes in gross investment levels in this sector. To this end, we used a formula determining the value of private investments from the theory of the economic dynamism of M. Kalecki. First, we checked its adjustment to the economic reality of the energy sector and analysed the impact of individual independent variables on gross investment levels. We calculated linear regression and correlation coefficients in two variants due to delays between investments and investment decisions. The results of the studies justified the hypothesis. According to it, gross investments in the Polish energy sector are determined by the level of gross savings of companies.
A Comparison Study between Universal Design for Learning-Multiple Intelligence (UDL-MI) Oriented STEM Program and Traditional STEM Program for Inclusive Education
Authors: Nasri Nurfarahin , Rahimi Nik Mohd , Nasri Nurfaradilla Mohamad , Talib Mohamad Asyraf Abd
Published: January 2021

The Universal Design for Learning (UDL) model and Multiple Intelligence (MI) theory hold considerable promise for advancing inclusive education. However, the effectiveness of UDL and MI in supporting inclusive science, technology, engineering, and mathematics (STEM) education has never been tested empirically. This study examined the impact of the UDL-MI-oriented STEM program on eighth-grade rural students’ attitudes towards STEM through mixed research design. A total of 122 students were selected through purposive sampling and randomly distributed into experimental (N = 62) and control groups (N = 60). The experimental group experienced STEM learning through the UDL-MI-oriented program and the control group received traditional classroom teaching. Both groups studied learning units on environmental sustainability and conservation for 10 weeks. Changes in students’ attitudes towards STEM were assessed over the time period (pre-test, post-test, follow-up) using an adapted Mahoney Student Attitude toward STEM instrument and individual interviews (post-test, follow-up). The results indicated that in comparison to the traditional classroom, the UDL-MI-oriented program significantly improved and maintained the students’ attitudes towards STEM. Next, the qualitative findings were presented to support the statistical analyses. This study provides empirical evidence for adopting the UDL-MI-oriented STEM program as an effective way of providing inclusive STEM education to rural students by enhancing their attitudes towards STEM.
Supervision of the Default Risk of Online Car-Hailing Platform from an Evolutionary Game Perspective
Authors: Weng Zhicheng , Luo Pinliang
Published: January 2021

Online car-hailing services are becoming a key component of the public transportation system, despite there being some certain risks, especially default risk. Turning to the evolutionary game method, this research constructed an evolutionary game model of online car-hailing platform, and then analyzed the equilibrium state of three scenarios (i.e., no supervision, internal supervision of platform enterprises, and external supervision of regulators), followed by carrying out a simulation. The results showed that to realize the evolution stability strategies (ESS) of default risk control, a strong credit constraint or the establishment of a coordinated supervision mode with appropriate intensity are needed. On this basis, this research puts forward the coordinated “platform enterprise + regulator” supervision mode, as well as the following four specific strategies: Promoting the construction of a credit system, strengthening the construction of laws and regulations, establishing a service process control mechanism, and introducing innovative regulatory means.
Cost Effective and Sustainable Test Methods to Investigate Vulnerabilities of EMP Attack on Existing Buildings Using Public Frequency Devices
Authors: Lim Chaeyeon , Min Kyungryeung , Kim Kukjoo , Park Young-Jun
Published: January 2021

High-power electromagnetic pulses are electromagnetic shock waves with strong energy, which can cause the destruction or malfunction of both electrical and electronic systems. The measurement of the electromagnetic wave shielding performance of buildings is effective for determining the level of EMP protection for each facility. However, it is extremely inefficient to practically measure the electromagnetic wave shielding performance using methods based on various standards for general buildings, in term of testing cost and time. Therefore, cost effective and sustainable test methods to investigate vulnerabilities of electromagnetic pulses attack on existing buildings using public frequency is proposed in this study. The study focuses on a simpler and more reliable method such as the use of broadcast or communication signals. From the results, it was concluded that the shielding performance can be measured approximately −45 dB using broadcast devices, −70 dB using walkie-talkie as simplified measurements of the electromagnetic-wave shielding performance. Therefore, if the test methods which are proposed in this study are allowed for preliminary investigation to find the vulnerabilities of existing buildings, cost and energy in the investigation can be reduced and it is expected to bring out frequency inspection and sustainable EMP protection performance of buildings.
Sustainable Organic Corn Production with the Use of Flame Weeding as the Most Sustainable Economical Solution
Authors: Rajković Miloš , Malidža Goran , Tomaš Simin Mirela , Milić Dragan , Glavaš-Trbić Danica , Meseldžija Maja , Vrbničanin Sava
Published: January 2021

Flame weeding is an alternative method of weed control. Essentially, it is a supplement to other physical and mechanical processes used in organic production. Weed control costs have a large share of the total cost of crop production. This study aimed to investigate hand weed hoeing’s cost-effectiveness, accompanied by inter-row cultivation and flame weeding applied in organic maize production using two different machines to determine the economically best solution. For this purpose, the prototype flame weeder and commercial flame-weeding machinery were used. Designed primarily for smaller fields, the prototype flame weeder was equipped with a cultivator and a 70 kg propane bottle. Commercial Red Dragon flame weeder, fitted with an 800 kg propane tank and featuring no cultivation implements, is designed for larger areas. The analysis has shown that hand hoeing produced a higher yield (8.3 t/ha in total), but it contributed significantly to the production costs. The costs per hectare decreased when the prototype flame weeder and the commercial Red Dragon flame weeder were used compared to hand hoeing. More beneficial economic impacts were recorded when the prototype flame weeder was used (489.39 €/ha) than in applying the Red Dragon flame weeder (456.47 €/ha). The efficacy of flame weeding is somewhat limited and could be enhanced by additional hand hoeing, if the effect of the machine in terms of weeding is observed. However, the analysis has shown that, in this case, investments in additional hand hoeing are not economically justified because the operating costs incurred therein (168 €/ha) were not met by a yield increase of 500 kg/ha, i.e., a surplus revenue of 100 €/ha. Moreover, the economic impacts of flame weeding would be considerably more significant in larger fields.
Impact of Climate Change on Cotton Production in Bangladesh
Authors: Nadiruzzaman Md , Rahman Mahjabeen , Pal Uma , Croxton Simon , Rashid Md Bazlur , Bahadur Aditya , Huq Saleemul
Published: January 2021

Bangladesh produces only 5% of the cotton she needs to sustain her readymade garments industries. The country has very limited agricultural land and cotton competes with other crops for this scarce land resource. On top of that, Bangladesh is regarded as a country where agriculture is highly vulnerable to the variabilities of weather patterns that result from climate change. Against this backdrop, to better understand the potential for the sustainable expansion of cotton production in Bangladesh, we examine cotton’s agricultural value chain and projected climate risks associated with different phases of the chain. We identified associated stakeholders at different phases of cotton production, engaged with them to understand climatic and non-climatic threats and developed an integrated set of recommendations for climate-risk management through improving the connection of producers to markets, increasing economic returns to small farmers, and improving efficiency along the value chain. We discussed our estimated climate projections with stakeholders to understand the challenges at different stages of production and marketing, and together explored and identified probable solutions. This research offers a new and evolving approach to assess climate change impact on agriculture utilizing a holistic approach, which could be adopted for other crops.
Optimal Design Model for a Residential PV Storage System an Application to the Spanish Case
Authors: Ballesteros-Gallardo Juan Antonio , Arcos-Vargas Angel , Núñez Fernando
Published: January 2021

Self-consumption of photovoltaic energy is being promoted as an effective way for energy consumption in residential households. The European Directive 944/2019 promotes the use of green energy and battery energy storage systems (BESS) for self-consumption and, in Spain, the 244/2019 Royal Decree of the Spanish electrical regulatory framework allows the self-consumption of energy with a photovoltaic (PV) facility for residential use, as well as the injection of the surplus energy into the grid for which compensation will be received. At the same time, new developments in PV and BESS technologies reduce the costs of facilities, a fact that can increase the profitability of self-consumption through PV energy. This study evaluates the profitability of a household PV facility with BESS using a model based on real market prices, hourly data from user smart meters, and their own location; especially, the model gives the best configuration of PV panels power and BESS capacity. The financial indicators taken as reference for the results and conclusions are the Net Present Value (NPV), Internal Rate of Return (IRR), and Investment Return (IR). Our method examines also the effect of the BESS and PV panel costs on the profitability of the facility. Unlike other studies, our model is based on actual (not simulated) demand and price data, and it can be easily extended to other locations and market prices.
The Production of Biogenic Silica from Different South African Agricultural Residues through a Thermo-Chemical Treatment Method
Authors: Maseko Ncamisile Nondumiso , Schneider Denise , Wassersleben Susan , Enke Dirk , Iwarere Samuel Ayodele , Pocock Jonathan , Stark Annegret
Published: January 2021

A thermo-chemical treatment method was used to produce biogenic amorphous silica from South African sugarcane and maize residues. Different fractions of South African sugarcane (leaves, pith, and fiber) were processed for silica production. The biomass samples were leached with either 7 wt% citric acid or 7 wt% sulfuric acid at 353 K for 2 h prior to being rinsed, dried and combusted using a four-step program ranging from room temperature to 873 K in a furnace. The characterization of the pre-treated biomass samples was conducted using thermogravimetric analysis (TG/DTA), X-ray fluorescence analysis (XRF) and elemental analysis (CHN), while the final products were characterized by XRF, X-ray diffraction (XRD), elemental analysis, nitrogen physisorption and scanning electron microscopy (SEM). Citric acid pre-treatment proved to be an attractive alternative to mineral acids. Amorphous biogenic silica was produced from sugarcane leaves in good quality (0.1 wt% residual carbon and up to 99.3 wt% silica content). The produced biogenic silica also had great textural properties such as a surface area of up to 323 m2 g−1, average pore diameter of 5.0 nm, and a pore volume of 0.41 cm3 g−1.
The Influence of Dynamic and Adaptive Marketing Capabilities on the Performance of Portuguese SMEs in the B2B International Market
Authors: Reimann Caroline , Carvalho Fernando , Duarte Marcelo
Published: January 2021

The present investigation aims study the sustainability of the business model of the Portuguese SMEs operating in the B2B International market analyzing the influence of dynamic marketing capabilities and adaptive marketing capabilities in their international marketing performance. It will also analyze the moderating effects of Competitive Intensity within this international scenario. A quantitative study was developed, using a questionnaire as a research method. In total, 335 valid responses were collected from Portuguese SMEs in June 2020. To test the hypotheses, multiple hierarchical regressions were performed. As for the analyzes involving Competitive Intensity environments, namely low and high intensity, dummies were developed to evaluate the different effects produced by the capacities in the International Marketing Performance. This study shows the positive impact of the dynamic marketing capabilities and adaptive marketing capabilities on the international marketing performance of the surveyed companies, essentially from the product development management, supply chain management, vigilant market learning and open marketing. when in a low competitive intensity environment only dynamic marketing capabilities had a positive effect on performance, but in a high, competitive, intensity environment both dynamic marketing capabilities and adaptive marketing capabilities showed positive effects in relation to performance. This study innovates by bringing international marketing, through two marketing capacities, from the perspective of SMEs that perform B2B activities.
Impact on the Virtual Learning Environment Due to COVID-19
Authors: Torres Martín César , Acal Christian , El Homrani Mohammed , Mingorance Estrada Ángel
Published: January 2021

As a result of the global pandemic caused by COVID-19, universities have carried out teaching in a digital way, accelerating the inclusion and use of technologies in methodological adaptation. The research aims to ascertain the perception that students at the Faculty of Education Sciences of the University of Granada have regarding the pedagogical model adopted in the virtual learning environment during confinement through the second semester of the 2019–2020 academic year. The information collection method was an online questionnaire, using simple random sampling with proportional affixing 0.5, 95% confidence level and maximum permissible error of 4.7%. The results demonstrate a generalised dissatisfaction of the students, being fundamental to carry out the transition of the educational processes and training of the teaching staff. The implementation of active methodologies increases due to the virtual condition, specifically the flipped classroom methodology, but students manifest generalised dissatisfaction regarding the adequate methodological development and the involvement of professors. There is an outstanding use of e-mail and the virtual learning platform (PRADO), although they consider that they do not have the appropriate knowledge about image editors, video, computer graphics, synchronous response systems and anti-plagiarism tools. The students surveyed express that the tutoring functions, tasks and beliefs of the teaching staff in e-learning are not satisfactory.
User Automotive Powertrain-Type Choice Model and Analysis Using Neural Networks
Authors: Marques dos Santos Fabio Luis , Tecchio Paolo , Ardente Fulvio , Pekár Ferenc
Published: January 2021

This paper presents an artificial neural network (ANN) model that simulates user’s choice of electric or internal combustion engine automotive vehicles based on basic vehicle attributes (purchase price, range, operating cost, taxes due to emissions, time to refuel/recharge and vehicle price depreciation), with the objective of analyzing user behavior and creating a model that can be used to support policymaking. The ANN was trained using stated preference data from a survey carried out in six European countries, taking into account petrol, diesel and battery electric automotive vehicle attributes. Model results show that the electric vehicle parameters (especially purchase cost, range and recharge times), as well as the purchase cost of internal combustion engine vehicles, have the most influence on consumers’ vehicle choices. A graphical interface was created for the model, to make it easier to understand the interactions between different attributes and their impacts on consumer choices and thus help policy decisions.
Radiant Floors versus Radiant Walls Using Ceramic Thermal Panels in Mediterranean Dwellings: Annual Energy Demand and Cost-Effective Analysis
Authors: Echarri-Iribarren Víctor , Wong Nyuk Hien , Sánchez-Ostiz Ana
Published: January 2021

The present study focuses on the application of large-format thermal ceramic conditioning panels (TCPs) containing polypropylene (PPR) capillary tube mats in dwellings on the Mediterranean coast. The thermal and energy behaviours were examined once the underfloor heating was installed, and they were compared with an alternative wall application. The system was implemented in a single-family house located on the Spanish Mediterranean coast. After having monitored the house during a complete one-year cycle, the annual energy demand was quantified using the Design Builder tool. TCP panels applied to radiant floors reduced energy demand by 5.15% compared to the wall-layout alternative. Significant reductions in CO2 emissions were also achieved, as well as a 25.19% reduction in energy demand compared to convection systems. The incorporation of 24 m2 of solar thermal panels into the system, combined with solar cooling systems based on lithium chloride, was also analysed. A reduction in energy demand of 57.46% was obtained compared to all-air convection systems. Finally, the amortisation periods of the investments in TCP panels and solar panels were calculated and compared to a convection system. Underfloor TCP panels proved to be more cost-effective than a wall installation. The additional cost of EUR 21,844 could be amortised over approximately 14 years with the radiant underfloor TCP system, while the wall TCP would be amortised over 17.4 years.
Mapping Urban Environmental Performance with Emerging Data Sources: A Case of Urban Greenery and Traffic Noise in Sydney, Australia
Authors: Nourmohammadi Zahra , Lilasathapornkit Tanapon , Ashfaq Mudabber , Gu Ziyuan , Saberi Meead
Published: January 2021

Measuring urban environmental performance supports understanding and improving the livability and sustainability of a city. Creating a more livable and attractive environment facilitates a greater shift to active and greener transport modes. Two key aspects, among many others, that determine the environmental performance of an urban area are greenery and noise. This study aims to map street-level greenery and traffic noise using emerging data sources including crowd-sourced mobile phone-based data and street-level imagery data in Sydney, Australia. Results demonstrate the applicability of emerging data sources and the presented advanced techniques in capturing the seasonal variations in urban greenery and time-dependent nature of traffic noise. Results also confirm the presence of a negative correlation between urban greenery and traffic noise.
Cooperative Societies and Sustainability: A Spatial Analysis of Andalusia as a Tool for Implementing Territorial Development Policies, Strategies and Initiatives
Authors: Pérez-González María del Carmen , Valiente-Palma Lidia
Published: January 2021

Local development strategies, policies and initiatives that contribute to sustainable development are gaining increasing prominence. Cooperative societies—the most relevant organisations within the social economy—are widely present in Andalusia and play a key role in boosting sustainable development through their principles and values. On this basis, the article aims to determine whether certain areas in Andalusia are more predisposed to the presence of these enterprises and are more sustainable as a result. The methods used include an adapted shift-share analysis and application of local Moran’s I to obtain spatial clusters allowing the areas most favourable to the presence of this type of organisation to be identified. Therefore, one of the main contributions of the study is that it provides a tool for the application of local development policies, strategies and initiatives involving cooperatives in pursuit of a more sustainable society.
Two-Dimensional Numerical Model for Stability Analysis of Tunnel Face Based on Particle Flow Code
Authors: Xie Tingwei , Han Kaihang
Published: January 2021

In this paper, numerical simulations of face stability of shallow tunnels are carried out by using the particle discrete element codes PFC2D from the microscopic view. Progressive instability of the tunnel face is achieved through the withdrawal of the baffle used to simulate the tunnel face. Under different retreating displacement of the tunnel face, the evolution laws of support pressure on the tunnel face, the ground deformation, ground surface settlement and contact force chain in front of the tunnel face are studied. The results show that with the withdrawal of the tunnel face, the support pressure on the tunnel face can be divided into four stages, namely, the rapid decline stage, the minimum stage, the slow rising stage, and the horizontal stability stage. Moreover, based on the simulation results of the particle contact force chain, discriminated methods of failure zones are proposed. The research results obtained from this paper will provide theoretical support for the reasonable value of support pressure of a tunnel face in practical engineering.
Path Planning of Hydraulic Support Pushing Mechanism Based on Extreme Learning Machine and Descartes Path Planning
Authors: Li Suhua , Xie Jiacheng , Wang Xuewen , Ren Fang , Zhang Xin , Bao Qingbao
Published: January 2021

As a floating system connecting hydraulic support and scraper conveyor, the path planning of pushing mechanism is of great significance for their coordinated movement. In this paper, a method for path planning of hydraulic support pushing mechanism based on extreme learning machine (ELM) and Descartes path planning is proposed. According to the motion characteristics of moving mechanism, it is transformed into industrial robot model, based on the characteristics of the coordinates of the key points on the ear seat of the scraper conveyor when advancing, a prediction method of the key points coordinates based on ELM is proposed, so the target location of the end-effector is obtained. The path of the joint is determined by polynomial path partition and Descartes path planning method. The path is modified by Gaussian filtering method, and the peak value of path obtained by planning is filtered out, and the path correction is realized. Finally, the virtual simulation test is carried out in Unity3D. The planned coordinate curve has Poisson-like distribution and approximately around the target coordinate curve, and local error and correction error are within 2 cm and 0.1 cm, respectively. The coordinate curve obtained by combining planning and correction has a better effect.
wUUNet: Advanced Fully Convolutional Neural Network for Multiclass Fire Segmentation
Authors: Bochkov Vladimir Sergeevich , Kataeva Liliya Yurievna
Published: January 2021

This article describes an AI-based solution to multiclass fire segmentation. The flame contours are divided into red, yellow, and orange areas. This separation is necessary to identify the hottest regions for flame suppression. Flame objects can have a wide variety of shapes (convex and non-convex). In that case, the segmentation task is more applicable than object detection because the center of the fire is much more accurate and reliable information than the center of the bounding box and, therefore, can be used by robotics systems for aiming. The UNet model is used as a baseline for the initial solution because it is the best open-source convolutional neural network. There is no available open dataset for multiclass fire segmentation. Hence, a custom dataset was developed and used in the current study, including 6250 samples from 36 videos. We compared the trained UNet models with several configurations of input data. The first comparison is shown between the calculation schemes of fitting the frame to one window and obtaining non-intersected areas of sliding window over the input image. Secondarily, we chose the best main metric of the loss function (soft Dice and Jaccard). We addressed the problem of detecting flame regions at the boundaries of non-intersected regions, and introduced new combinational methods of obtaining output signal based on weighted summarization and Gaussian mixtures of half-intersected areas as a solution. In the final section, we present UUNet-concatenative and wUUNet models that demonstrate significant improvements in accuracy and are considered to be state-of-the-art. All models use the original UNet-backbone at the encoder layers (i.e., VGG16) to demonstrate the superiority of the proposed architectures. The results can be applied to many robotic firefighting systems.
Neutral Delay Differential Equations: Oscillation Conditions for the Solutions
Authors: Bazighifan Omar , Alotaibi Hammad , Mousa Abd Allaah A.
Published: January 2021

The purpose of this article is to explore the asymptotic properties for a class of fourth-order neutral differential equations. Based on a comparison with the differential inequality of the first-order, we have provided new oscillation conditions for the solutions of fourth-order neutral differential equations. The obtained results can be used to develop and provide theoretical support for and to further develop the study of oscillation for a class of fourth-order neutral differential equations. Finally, we provide an illustrated example to demonstrate the effectiveness of our new criteria.
Controlling Safety of Artificial Intelligence-Based Systems in Healthcare
Authors: Davahli Mohammad Reza , Karwowski Waldemar , Fiok Krzysztof , Wan Thomas , Parsaei Hamid R.
Published: January 2021

Artificial intelligence (AI)-based systems have achieved significant success in healthcare since 2016, and AI models have accomplished medical tasks, at or above the performance levels of humans. Despite these achievements, various challenges exist in the application of AI in healthcare. One of the main challenges is safety, which is related to unsafe and incorrect actions and recommendations by AI algorithms. In response to the need to address the safety challenges, this research aimed to develop a safety controlling system (SCS) framework to reduce the risk of potential healthcare-related incidents. The framework was developed by adopting the multi-attribute value model approach (MAVT), which comprises four symmetrical parts: extracting attributes, generating weights for the attributes, developing a rating scale, and finalizing the system. The framework represents a set of attributes in different layers and can be used as a checklist in healthcare institutions with implemented AI models. Having these attributes in healthcare systems will lead to high scores in the SCS, which indicates safe application of AI models. The proposed framework provides a basis for implementing and monitoring safety legislation, identifying the risks in AI models’ activities, improving human-AI interactions, preventing incidents from occurring, and having an emergency plan for remaining risks.
Blood Pressure Correlates Asymmetrically with Neuropeptidase Activities of the Left and Right Frontal Cortices
Authors: Segarra Ana Belén , Prieto Isabel , Banegas Inmaculada , Martínez-Cañamero Magdalena , de Gasparo Marc , Ramírez-Sánchez Manuel
Published: January 2021

It was suggested that the brain-heart connection is asymmetrically organized. However, evidence connecting neurochemical factors from each brain hemisphere with changes in cardio-vascular functions have not yet been reported. In order to analyze potential asymmetrical connections between brain neurochemical factors with cardio-vascular functions, we studied the level of correlations between the left and right frontal cortex (FC) soluble (Sol) and membrane-bound (MB) neuropeptide-degrading enzymes alanyl (AlaAP), cystinyl (CysAP), and glutamyl (GluAP) aminopeptidase activities, involved among others in the metabolism of angiotensins, with heart rate (HR), systolic (SBP), and diastolic (DBP) blood pressure, in rats treated or not with hypotensive or hypertensive drugs such as captopril, propranolol or L-NAME. The present study suggests the existence of a bidirectional asymmetrical connection between these brain neuropeptidases and cardio-vascular functions. Specifically, depending on treatment, in control group, Sol AlaAP from the left FC correlates negatively with SBP and DBP. In captopril-treated animals, MB CysAP and MB GluAP from the right FC correlate negatively with HR. In L-NAME treated rats, Sol CysAP from the right FC correlates negatively with DBP. No significant correlations were observed in the propranolol group. Considering together all the values obtained from the left or the right cortex of the four groups regardless of drug treatment, the results demonstrated significant negative correlations between these neuropeptidase activities, mainly from the left frontal cortex, with the levels of systolic and diastolic blood pressure. Remarkably, these findings contrast drastically with previously reported results indicating significant positive correlations between the left frontal cortex with other peripheral functions such as water intake and diuresis. Both results represent noteworthy information that strongly supports the concept of a bidirectional asymmetric organization of neurovisceral integration involving left and right brain neurochemical processes with peripheral physiological functions, most probably mediated by the autonomic nervous system. Overall, the present results suggest that cognitive functions involving the frontal cortex may be asymmetrically connected with peripheral physiological processes, and vice versa.
A Two-Year Occurrence of Fusarium T-2 and HT-2 Toxin in Croatian Cereals Relative of the Regional Weather
Authors: Kiš Maja , Vulić Ana , Kudumija Nina , Šarkanj Bojan , Jaki Tkalec Vesna , Aladić Krunoslav , Škrivanko Mario , Furmeg Sanja , Pleadin Jelka
Published: January 2021

To investigate into the T-2 and HT-2 toxin occurrence, 240 samples of unprocessed cereals (maize, wheat, barley, and oats) were sampled from different fields located in three Croatian regions during 2017–2018. In all samples, sum concentrations of T-2/HT-2 toxin were determined using the ELISA method, while the LC-MS/MS was used as a confirmatory method for both mycotoxins in positive samples (>LOD) and the establishment of T-2 over HT-2 toxin ratios. The results showed oats to be the most contaminated cereal, with T-2/HT-2 toxins detected in 70.0% of samples, followed by barley (40.9%), maize (26.8%) and wheat (19.2%), with the mean T-2/HT-2 ratio ranging from 1:2.7 in maize to 1:4.4 in oats. Sum T-2/HT-2 concentrations in two maize samples were higher than the indicative level recommended by the European Commission, necessitating subsequent investigations into the conditions under which these poorly investigated mycotoxins are produced. Statistically significantly (p < 0.05) higher concentrations of T-2/HT-2 toxin were determined in oats throughout study regions as compared to those found in wheat, but not maize and barley, while the concentrations of these mycotoxins were related to the regional weather in Croatia.
Direct and Competitive Optical Grating Immunosensors for Determination of Fusarium Mycotoxin Zearalenone
Authors: Székács Inna , Adányi Nóra , Szendrő István , Székács András
Published: January 2021

Novel optical waveguide lightmode spectroscopy (OWLS)-based immunosensor formats were developed for label-free detection of Fusarium mycotoxin zearalenone (ZON). To achieve low limits of detection (LODs), both immobilised antibody-based (direct) and immobilised antigen-based (competitive) assay setups were applied. Immunoreagents were immobilised on epoxy-, amino-, and carboxyl-functionalised sensor surfaces, and by optimising the immobilisation methods, standard sigmoid curves were obtained in both sensor formats. An outstanding LOD of 0.002 pg/mL was obtained for ZON in the competitive immunosensor setup with a dynamic detection range between 0.01 and 1 pg/mL ZON concentrations, depending on the covalent immobilisation method applied. This corresponds to a five orders of magnitude improvement in detectability of ZON relative to the previously developed enzyme-linked immonosorbent assay (ELISA) method. The selectivity of the immunosensor for ZON was demonstrated with structural analogues (α-zearalenol, α-zearalanol, and β-zearalanol) and structurally unrelated mycotoxins. The method was found to be applicable in maize extract using acetonitrile as the organic solvent, upon a dilution rate of 1:10,000 in buffer. Thus, the OWLS immunosensor method developed appears to be suitable for the quantitative determination of ZON in aqueous medium. The new technique can widen the range of sensoric detection methods of ZON for surveys in food and environmental safety assessment.
Silver-109/Silver/Gold Nanoparticle-Enhanced Target Surface-Assisted Laser Desorption/Ionisation Mass Spectrometry—The New Methods for an Assessment of Mycotoxin Concentration on Building Materials
Authors: Szulc Justyna , Kołodziej Artur , Ruman Tomasz
Published: January 2021

This study aimed to detect and quantify mycotoxins on building materials using innovative laser mass spectroscopy methods—silver-109/silver/gold nanoparticle-enhanced target surface-assisted laser desorption/ionisation mass spectrometry (109AgNPs, AgNPs and AuNPs SALDI). Results from SALDI-type methods were also compared with commonly used matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Standards of seven moulds mycotoxin in a final concentration of 100 µg/mL for patulin, citrinin, 3-nitropropionic acid, alternariol and 20 µg/mL for sterigmatocystin, cyclopiazonic acid, roquefortine C in the mixture were tested in pure solutions and after extraction from the plasterboards. Among the studied SALDI-type method, the lowest detection limits and the highest signal intensity of the mycotoxins tested were obtained with the use of 109AgNPs SALDI MS. The 109AgNPs method may be considered as an alternative to the currently most frequently used method MALDI MS and also liquid chromatography tandem mass spectrometry LC-MS/MS for mycotoxin determination. Future studies should attempt to use these methods for mass spectrometry imaging (MSI) to evaluate spatial distribution and depth of mycotoxin penetration into building materials.
Electric Eels Wield a Functional Venom Analogue
Authors: Catania Kenneth C.
Published: January 2021

In this paper, I draw an analogy between the use of electricity by electric eels (Electrophorus electricus) to paralyze prey muscles and the use of venoms that paralyze prey by disrupting the neuromuscular junction. The eel’s strategy depends on the recently discovered ability of eels to activate prey motor neuron efferents with high-voltage pulses. Usually, eels use high voltage to cause brief, whole-body tetanus, thus preventing escape while swallowing prey whole. However, when eels struggle with large prey, or with prey held precariously, they often curl to bring their tail to the opposite side. This more than doubles the strength of the electric field within shocked prey, ensuring maximal stimulation of motor neuron efferents. Eels then deliver repeated volleys of high-voltage pulses at a rate of approximately 100 Hz. This causes muscle fatigue that attenuates prey movement, thus preventing both escape and defense while the eel manipulates and swallows the helpless animal. Presumably, the evolution of enough electrical power to remotely activate ion channels in prey efferents sets the stage for the selection of eel behaviors that functionally “poison” prey muscles.
Baseline and Impact of First-Year Intervention on Schistosoma haematobium Infection in Seasonal Transmission Foci in the Northern and Central Parts of Côte d’Ivoire
Authors: Diakité Nana R. , Ouattara Mamadou , Bassa Fidèle K. , Coulibaly Jean T. , Tian-Bi Yves-Nathan T. , Meïté Aboulaye , Hattendorf Jan , Utzinger Jürg , N’Goran Eliézer K.
Published: January 2021

In order to assess the impact of different control strategies against Schistosoma haematobium in seasonal transmission foci in Côte d’Ivoire, a three-year cluster randomized trial was implemented. The decrease in S. haematobium prevalence among children aged 9−12 years was the primary outcome. In the first step, an eligibility survey was conducted, subjecting 50 children aged 13−14 years to a single urine filtration. Sixty-four villages with a prevalence of S. haematobium of ≥4% were selected and randomly assigned to four intervention arms consisting of annual mass drug administration (MDA) before (arm 1) and after (arm 2) the peak transmission, biannual treatment with praziquantel before and after the peak transmission season (arm 3), and annual MDA before the peak transmission season, coupled with focal chemical snail control using molluscicides (arm 4). At baseline, we observed a prevalence of 24.8%, 10.1%, 13.9%, and 15.9% in study arms 1, 2, 3, and 4, respectively. One year after the first intervention, the prevalence decreased in all study arms by about two-thirds or more. The prevalence in arm 2 was lower than in arm 1 (3.5% vs. 8.1%), but the difference was not statistically significant (odds ratio (OR) = 0.42, 95% confidence interval (CI) = 0.10−1.80). After adjusting for baseline prevalence, arms 1 and 2 performed roughly similarly (adjusted odds ratio (aOR) = 1.03, 95% CI = 0.34−3.07). The prevalence in arms 3 and 4 (1.9% and 2.2%) were significantly lower compared to arm 1 in the unadjusted and the adjusted models (arm 3 vs. arm 1, OR = 0.22, 95% CI = 0.05−0.95, aOR = 0.19, 95% CI = 0.08−0.48; arm 4 vs. arm 1, OR = 0.26, 95% CI = 0.08−0.85, aOR = 0.23, 95% CI = 0.06−0.87). The initial intervention showed a significant impact on the prevalence of S. haematobium. It will be interesting to monitor the comparative impact of the different intervention arms and to determine whether the interruption of seasonal transmission of S. haematobium can be achieved in this epidemiological setting within three years.
HCMV-Mediated Interference of Bortezomib-Induced Apoptosis in Colon Carcinoma Cell Line Caco-2
Authors: Härtel Heike , Theiß Janine , Abdelaziz Mohammed O. , Raftery Martin J. , Pecher Gabriele , Bogner Elke
Published: January 2021

Human cytomegalovirus (HCMV) has been implicated in the development of human malignancies, for instance in colon cancer. Proteasome inhibitors were developed for cancer therapy and have also been shown to influence HCMV infection. The aim of this study was to investigate if proteasome inhibitors have therapeutic potential for colon carcinoma and how this is influenced by HCMV infection. We show by immunofluorescence and flow cytometry that the colon carcinoma cell line Caco-2 is susceptible to HCMV infection. Growth curve analysis as well as protein expression kinetics and quantitative genome analysis further confirm these results. HCMV has an anti-apoptotic effect on Caco-2 cells by inhibiting very early events of the apoptosis cascade. Further investigations showed that HCMV stabilizes the membrane potential of the mitochondria, which is typically lost very early during apoptosis. This stabilization is resistant to proteasome inhibitor Bortezomib treatment, allowing HCMV-infected cells to survive apoptotic signals. Our findings indicate a possible role of proteasome inhibitors in colon carcinoma therapy.
Mixed Effects of Habitat Degradation and Resources on Hantaviruses in Sympatric Wild Rodent Reservoirs within a Neotropical Forest
Authors: Camp Jeremy V. , Spruill-Harrell Briana , Owen Robert D. , Solà-Riera Carles , Williams Evan P. , Eastwood Gillian , Sawyer Aubrey M. , Jonsson Colleen B.
Published: January 2021

Understanding the ecology of rodent-borne hantaviruses is critical to assessing the risk of spillover to humans. Longitudinal surveys have suggested that hantaviral prevalence in a given host population is tightly linked to rodent ecology and correlates with changes in the species composition of a rodent community over time and/or habitat composition. We tested two hypotheses to identify whether resource addition and/or habitat composition may affect hantavirus prevalence among two sympatric reservoir hosts in a neotropical forest: (i) increased food resources will alter the rodent community and thus hantaviral prevalence; and (ii) host abundance and viral seroprevalence will be associated with habitat composition. We established a baseline of rodent–virus prevalence in three grid pairs of distinct habitat compositions and subjected one grid of each pair to resource augmentation. Increased rodent species diversity was observed on grids where food was added versus untreated control grids during the first post-treatment sampling session. Resource augmentation changed species community composition, yet it did not affect the prevalence of hantavirus in the host population over time, nor was there evidence of a dilution effect. Secondly, we show that the prevalence of the virus in the respective reservoir hosts was associated with habitat composition at two spatial levels, independent of resource addition, supporting previous findings that habitat composition is a primary driver of the prevalence of hantaviruses in the neotropics.
The Next Generation of Influenza Vaccines: Towards a Universal Solution
Authors: McMillan Christopher L.D. , Young Paul R. , Watterson Daniel , Chappell Keith J.
Published: January 2021

Influenza viruses remain a constant burden in humans, causing millions of infections and hundreds of thousands of deaths each year. Current influenza virus vaccine modalities primarily induce antibodies directed towards the highly variable head domain of the hemagglutinin protein on the virus surface. Such antibodies are often strain-specific, meaning limited cross-protection against divergent influenza viruses is induced, resulting in poor vaccine efficacy. To attempt to counteract this, yearly influenza vaccination with updated formulations containing antigens from more recently circulating viruses is required. This is an expensive and time-consuming exercise, and the constant arms race between host immunity and virus evolution presents an ongoing challenge for effective vaccine development. Furthermore, there exists the constant pandemic threat of highly pathogenic avian influenza viruses with high fatality rates (~30–50%) or the emergence of new, pathogenic reassortants. Current vaccines would likely offer little to no protection from such viruses in the event of an epidemic or pandemic. This highlights the urgent need for improved influenza virus vaccines capable of providing long-lasting, robust protection from both seasonal influenza virus infections as well as potential pandemic threats. In this narrative review, we examine the next generation of influenza virus vaccines for human use and the steps being taken to achieve universal protection.
Identification of Promiscuous African Swine Fever Virus T-Cell Determinants Using a Multiple Technical Approach
Authors: Bosch-Camós Laia , López Elisabet , Navas María Jesús , Pina-Pedrero Sonia , Accensi Francesc , Correa-Fiz Florencia , Park Chankyu , Carrascal Montserrat , Domínguez Javier , Salas Maria Luisa , Nikolin Veljko , Collado Javier , Rodríguez Fernando
Published: January 2021

The development of subunit vaccines against African swine fever (ASF) is mainly hindered by the lack of knowledge regarding the specific ASF virus (ASFV) antigens involved in protection. As a good example, the identity of ASFV-specific CD8+ T-cell determinants remains largely unknown, despite their protective role being established a long time ago. Aiming to identify them, we implemented the IFNγ ELISpot as readout assay, using as effector cells peripheral blood mononuclear cells (PBMCs) from pigs surviving experimental challenge with Georgia2007/1. As stimuli for the ELISpot, ASFV-specific peptides or full-length proteins identified by three complementary strategies were used. In silico prediction of specific CD8+ T-cell epitopes allowed identifying a 19-mer peptide from MGF100-1L, as frequently recognized by surviving pigs. Complementarily, the repertoire of SLA I-bound peptides identified in ASFV-infected porcine alveolar macrophages (PAMs), allowed the characterization of five additional SLA I-restricted ASFV-specific epitopes. Finally, in vitro stimulation studies using fibroblasts transfected with plasmids encoding full-length ASFV proteins, led to the identification of MGF505-7R, A238L and MGF100-1L as promiscuously recognized antigens. Interestingly, each one of these proteins contain individual peptides recognized by surviving pigs. Identification of the same ASFV determinants by means of such different approaches reinforce the results presented here.
Impact of Recommended Maternal Vaccination Programs on the Clinical Presentation of SARS-CoV-2 Infection: A Prospective Observational Study
Authors: de la Cruz Conty Maria , Encinas Pardilla Maria , Garcia Sanchez Marta , Gonzalez Rodriguez Laura , Muner-Hernando Marta , Royuela Vicente Ana , Pintado Recarte Pilar , Martinez Varea Alicia , Martinez Diago Clara , Cruz Melguizo Sara , Martinez-Perez Oscar ,   on behalf of the Spanish Obstetric Emergency Group
Published: January 2021

The COVID-19 pandemic has raised questions about the possible cross immunity resulting from common vaccination programs and SARS-CoV-2 infection. Therefore, the Spanish Obstetric Emergency group performed a multicenter prospective study on the vaccination status of Influenza and Tdap (diphtheria, tetanus and pertussis vaccine boost administered in adulthood) in consecutive cases of SARS-CoV-2 infection in a pregnancy cohort, in order to assess its possible association with the clinical presentation and severity of symptoms of SARS-CoV-2 infection, as well as to determine the factors that may affect vaccination adherence. A total of 1150 SARS-CoV-2 positive pregnant women from 78 Spanish hospitals were analyzed: 183 had not received either vaccine, 23 had been vaccinated for Influenza only, 529 for Tdap only and 415 received both vaccines. No association was observed between the vaccination status and the clinical presentation of SARS-CoV-2 infection and/or the severity of symptoms. However, a lower adherence to the administration of both vaccines was observed in the Latin-American subgroup. Based on the results above, we reinforce the importance of maternal vaccination programs in the actual pandemic. Health education campaigns should be specially targeted to groups less likely to participate in these programs, as well as for a future SARS-CoV-2 vaccination campaign.