bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Hot Water and Ultrasonication Pretreatment of Microalgae (Nannochloropsis oculata) on Biogas Production in Anaerobic Co-Digestion with Cow Manure
Authors: Saleem Muhammad , Hanif Muhammad Usman , Bahadar Ali , Iqbal Hamid , Capareda Sergio C. , Waqas Adeel
Published: November 2020

Anaerobic co-digestion provides a promising solution for converting inexpensive carbon from wastes to biogenic methane. We used microalgae (Nannochloropsis oculata) with cow manure and sludge to produce a better quantity and quality of biogas. To further improve the gas production, microalgae were pretreated with ultrasonication, hot water, and a combination of both. Interestingly, the results showed that the pretreatment of microalgae decreased biogas production by 5 to 30%. The no-pretreatment runs produced a maximum of 118 L of biogas. The relative content of biogenic methane was higher in the pretreated feedstock (48 to 52%) in comparison with the no-pretreatment runs (44%). The conversion of volatile suspended solids present in the feedstock to total biogenic methane production was highest in hot-water-treated runs. The carbon content in the gas produced by the pretreated microalgae peaked (38%) in the middle of the experiment (i.e., at 45 days), whereas for no-pretreatment runs, the content remained constant from the start to the middle and declined (from 36 to 34%) at the end of the experiment (i.e., at 90 days). We also report the chemical structure of microalgae with and without pretreatments.
Modeling Bidirectional Polarization Distribution Function of Land Surfaces Using Machine Learning Techniques
Authors: Liu Siyuan , Lin Yi , Yan Lei , Yang Bin
Published: November 2020

Accurate estimation of polarized reflectance (Rp) of land surfaces is critical for remote sensing of aerosol optical properties. In the last two decades, many data-driven bidirectional polarization distribution function (BPDF) models have been proposed for accurate estimation of Rp, among which the generalized regression neural network (GRNN) based BPDF model has been reported to perform the best. GRNN is just a simple machine learning (ML) technique that can solve non-linear problems. Many ML techniques were reported to work well in solving non-linear problems and consequently may provide better performance in BPDF modeling. However, incorporating various ML techniques with BPDF modeling and comparing their performances have never been well documented. In this study, three widely used ML algorithms—i.e., support vector regression (SVR), K-nearest-neighbor (KNN), and random forest (RF)—were applied for BPDF modeling. Using measurements collected by the Polarization and Directionality of the Earth’s Reflectance onboard PARASOL satellite (POLDER/PARASOL), non-linear relationships between Rp and the input variables, i.e., Fresnel factor (Fp), scattering angle (SA), reflectance at 670 nm (R670) and 865 nm (R865), were built using these ML algorithms. Results showed that taking Fp, SA, R670, and R865 as input variables, the performance of the four ML-based BPDF models was quite similar. The KNN-based BPDF model provided slightly better results, and improved the accuracy of the semi-empirical BPDF models by 9.55% in terms of the overall root mean square error (RMSE). Experiments of different configuration of input variables suggested that using multi-band reflectance as input variables provided better results than using vegetation indices. The RF-based BPDF model using all reflectances at six bands as input variables produced the best results, improving the overall accuracy by 6.62% compared with the GRNN-based BPDF model. Among all the input variables, reflectance at absorbing spectral bands—e.g., 490 nm and 670 nm—played more significant roles in RF-based BPDF modeling due to the domination of polarized partition in total reflectance. Fresnel factor and scattering angle were also important for BPDF modeling. This study confirmed the feasibility of applying ML techniques to more accurate BPDF modeling, and the RF-based BPDF model proposed in this study can be used to increase the accuracy of remote sensing of the complete aerosol properties.
CNN-Based Tree Species Classification Using High Resolution RGB Image Data from Automated UAV Observations
Authors: Egli Sebastian , Höpke Martin
Published: November 2020

Data on the distribution of tree species are often requested by forest managers, inventory agencies, foresters as well as private and municipal forest owners. However, the automated detection of tree species based on passive remote sensing data from aerial surveys is still not sufficiently developed to achieve reliable results independent of the phenological stage, time of day, season, tree vitality and prevailing atmospheric conditions. Here, we introduce a novel tree species classification approach based on high resolution RGB image data gathered during automated UAV flights that overcomes these insufficiencies. For the classification task, a computationally lightweight convolutional neural network (CNN) was designed. We show that with the chosen CNN model architecture, average classification accuracies of 92% can be reached independently of the illumination conditions and the phenological stages of four different tree species. We also show that a minimal ground sampling density of 1.6 cm/px is needed for the classification model to be able to make use of the spatial-structural information in the data. Finally, to demonstrate the applicability of the presented approach to derive spatially explicit tree species information, a gridded product is generated that yields an average classification accuracy of 88%.
Development of an IoT Structural Monitoring System Applied to a Hypogeal Site
Authors: De Angelis Alessio , Santoni Francesco , Carbone Paolo , Cecconi Manuela , Vecchietti Alessia , Di Lorenzo Francesco
Published: November 2020

This paper describes the development of a distributed sensing system that can be disseminated in an environment of interest to monitor the vibration of a structure. This low-cost system consists of several sensor nodes and a central receiving node. All nodes are built using off-the-shelf electronic components. Each of the sensor nodes is battery-powered and equipped with a triaxial MEMS accelerometer, a wireless Long Range (LoRa) transceiver module for data transmission, a GPS module used for synchronization, and a microcontroller. The operation of the sensor node is validated by controlled laboratory tests where it is compared to a commercial reference accelerometer. Furthermore, the feasibility and potential benefits of the application of the proposed system to a structure in an archaeological site is investigated. Results show that the proposed sensor node could successfully monitor the vibration at several locations within the site. Therefore, it may be employed to detect the most relevant stresses to the structure, allowing for the identification of risks.
ResUHUrge: A Low Cost and Fully Functional Ventilator Indicated for Application in COVID-19 Patients
Authors: Vivas Fernández Francisco José , Sánchez Segovia José , Martel Bravo Ismael , García Ramos Carlos , Ruiz Castilla Daniel , Gamero López José , Andújar Márquez José Manuel
Published: November 2020

Although the cure for the SARS-CoV-2 virus (COVID-19) will come in the form of pharmaceutical solutions and/or a vaccine, one of the only ways to face it at present is to guarantee the best quality of health for patients, so that they can overcome the disease on their own. Therefore, and considering that COVID-19 generally causes damage to the respiratory system (in the form of lung infection), it is essential to ensure the best pulmonary ventilation for the patient. However, depending on the severity of the disease and the health condition of the patient, the situation can become critical when the patient has respiratory distress or becomes unable to breathe on his/her own. In that case, the ventilator becomes the lifeline of the patient. This device must keep patients stable until, on their own or with the help of medications, they manage to overcome the lung infection. However, with thousands or hundreds of thousands of infected patients, no country has enough ventilators. If this situation has become critical in the Global North, it has turned disastrous in developing countries, where ventilators are even more scarce. This article shows the race against time of a multidisciplinary research team at the University of Huelva, UHU, southwest of Spain, to develop an inexpensive, multifunctional, and easy-to-manufacture ventilator, which has been named ResUHUrge. The device meets all medical requirements and is developed with open-source hardware and software.
Bidirectional Attention for Text-Dependent Speaker Verification
Authors: Fang Xin , Gao Tian , Zou Liang , Ling Zhenhua
Published: November 2020

Automatic speaker verification provides a flexible and effective way for biometric authentication. Previous deep learning-based methods have demonstrated promising results, whereas a few problems still require better solutions. In prior works examining speaker discriminative neural networks, the speaker representation of the target speaker is regarded as a fixed one when comparing with utterances from different speakers, and the joint information between enrollment and evaluation utterances is ignored. In this paper, we propose to combine CNN-based feature learning with a bidirectional attention mechanism to achieve better performance with only one enrollment utterance. The evaluation-enrollment joint information is exploited to provide interactive features through bidirectional attention. In addition, we introduce one individual cost function to identify the phonetic contents, which contributes to calculating the attention score more specifically. These interactive features are complementary to the constant ones, which are extracted from individual speakers separately and do not vary with the evaluation utterances. The proposed method archived a competitive equal error rate of 6.26% on the internal “DAN DAN NI HAO” benchmark dataset with 1250 utterances and outperformed various baseline methods, including the traditional i-vector/PLDA, d-vector, self-attention, and sequence-to-sequence attention models.
The Value of Cluster Association for Digital Marketing in Tourism Regional Development
Authors: Tarazona-Montoya Raúl , Peris-Ortiz Marta , Devece Carlos
Published: November 2020

This paper analyses the advantages of membership in a cluster in the effective use of digital marketing tools and in a general way, in the performance, especially for the small and medium firms in underdeveloped regions. For this purpose, a case method research was conducted in the tourism sector, specifically in the hotels in the La Guajira Department, Colombia, where there is a regional tourism cluster. The tourism sector especially depends on digital marketing and the proper use of available digital marketing tools play an essential role in the performance. To conduct the study, 40 hotels in La Guajira were analyzed, whether or not they were members in the cluster. The obtained data were assessed by means of fuzzy set Qualitative Comparative Analysis to check the hypotheses. The results reveal the most effective combinations of digital marketing tools and the activities in which especially small and medium firms must engage in the cluster to obtain better results.
Physiological Effects of Visual Stimulation Using Knotty and Clear Wood Images among Young Women
Authors: Ikei Harumi , Nakamura Masashi , Miyazaki Yoshifumi
Published: November 2020

Wood is a sustainable and natural material used in interior design for living environment. Knots are prominent features on wood surfaces, and they affect a user’s building preference and impression. Data on the effects of wood knots on human physiological responses are limited. Hence, further studies should be conducted. This study examined the effects of interior wall images comprising knotty or clear wood on physiological responses. Computer graphics were used to prepare wall images of knotty or clear lumber. A gray image was set as the control. In total, 28 adult Japanese female university students were included in this study. They observed two types of wood interior wall images for 90 s. The control was also set for 90 s. The oxyhemoglobin level in the prefrontal cortex measured by near-infrared time-resolved spectroscopy (TRS) and the activities of parasympathetic and sympathetic nerves assessed using the heart rate variability (HRV) were utilized as physiological indexes. TRS sensors, which emit and receive near-infrared light, were attached to frontal pole (Fp) 1 and Fp2, based on the international 10–20 method. R-R interval was measured using HRV sensors attached based on the three-point guidance method, and frequency data were analyzed to assess high frequency (HF), which reflects parasympathetic nervous system activity, and the ratio of high and low frequencies (LF/HF), which reflects sympathetic nervous system activity. The knotty wood sedated the right prefrontal cortex activity compared with the control and enhanced parasympathetic nerve activity compared with before stimulation. Clear wood sedated the left prefrontal cortex activity compared with the control and suppressed sympathetic nerve activity compared with before stimulation. Subjective evaluations revealed that compared with gray wall images, both knotty and clear wood images significantly promoted comfort, relaxation, and natural feeling and improved overall mood states. In addition, clear wood image had a more positive subjective effect than knotty image. Wall images comprising knotty or clear wood, when used as a visual stimulus, have a physiological relaxation effect among adult women in their 20s.
Land Cover Change and Landscape Transformations (2000–2018) in the Rural Municipalities of the Upper Silesia-Zagłębie Metropolis
Authors: Pukowiec-Kurda Katarzyna , Vavrouchová Hana
Published: November 2020

Dynamic changes in the landscape have been observed in recent years. They are particularly visible in areas with a high degree of anthropopressure. An example of such areas is metropolitan regions and their immediate rural surroundings. The purpose of this article is to identify changes in land cover in the rural municipalities within metropolises and detect the processes of landscape transformation in rural areas, which are extremely sensitive to anthropopressure. The dynamics of land cover changes in the years 2000–2018 were determined using a change index (ChI), and their directions were determined using the indicator of changes in types of land cover. Corine Land Cover for level 2 groups (1.1–4.2) was used as research material, and the Upper Silesia-Zagłębie Metropolis was selected as the model area. The greatest changes in the landscape were observed in built-up areas, industrial areas, meadows and mining areas. This is due to the disappearance of the mining industry that was traditional for this region and the ongoing suburbanization process, as well as the re-industrialization of modern industry and the abandonment of arable land in rural areas.
The Path of Petrila Mining Area towards Future Industrial Heritage Tourism Seen through the Lenses of Past and Present
Authors: Ionica Andreea , Samuil Ionela , Leba Monica , Toderas Mihaela
Published: November 2020

The paper explores the industrial tourism development potential of a former mining area in Petrila, Jiu Valley, Romania, drastically affected by deindustrialization, in order to build a theme park in the old mine site. The research context is determined by the current economic and social state of the area, and also by the potential of the identified industrial heritage elements. For this reason, there was developed an optimal selection algorithm, based on multi-criteria analysis and Greedy approach. This optimal selection algorithm blends the objectivity of the technical-economic studies and the subjectivity of the residents’ perceptions of community satisfaction. After carrying out the Petrila case study, the results of the proposed algorithm application concerning the destination, from the point of view of their use, of each existing building in the Petrila site was determined. Compared with other studies, ours considers different criteria and can always be reapplied to validate or refine the selection based on new emerging inputs.
COVID-19, Storms, and Floods: Impacts of Tropical Storm Cristobal in the Western Sector of the Yucatan Peninsula, Mexico
Authors: Frausto-Martínez Oscar , Aguilar-Becerra Cesar Daniel , Colín-Olivares Orlando , Sánchez-Rivera Gabriel , Hafsi Adel , Contreras-Tax Alex Fernando , Uhu-Yam Wilberth David
Published: November 2020

The presence of extreme hydrometeorological threats has co-occurred with the COVID-19 pandemic, increasing the potential risk of a disaster scenario occurring. The hurricane “Cristobal”, which impacted Mexico’s tropical regions, presented a high risk of contagion and death caused by the combined effects of violent winds, floods, and evacuations. This work aims to determine whether the presence of concurrent events during the pandemic caused an increase in confirmed positive COVID-19 cases in the Yucatan Peninsula’s western sector. To achieve this, a numerical analysis and identification of the tropical storm’s extreme characteristics were conducted. Next, a combined analysis of the territorial system subject to flooding and the rainfall level reported during the emergency period was conducted at the municipal level. The third phase consisted of analyzing the confirmed positive cases of COVID-19 at the municipal level on four strategic dates (before, during, observation, and end of the emergency period). Finally, a content analysis of the emergency bulletins, action guides, and disaster declarations was carried out to identify the measures and adaptations implemented during the pandemic. It is recognized that emergency management measures were implemented for municipalities with more than 30 confirmed positive cases of COVID-19 and where the shelter capacity was reduced. Protocols for caring for people were followed, these being one of the leading adaptive methods. From the analyzed data, it can be pointed out that there is no direct evidence for an increase in positive COVID-19 cases in 10 of the municipalities. However, in the case of the municipality of Escarcega, there was a sudden increase in cases from June 8, which continues to grow. Therefore, it is necessary to deepen the study of multiple events to recognize the actions that can prevent catastrophes in these times of crisis.
Assessment of Industry 4.0 Maturity Models by Design Principles
Authors: Dikhanbayeva Dinara , Shaikholla Sabit , Suleiman Zhanybek , Turkyilmaz Ali
Published: November 2020

The fourth industrial revolution and accompanying digital transformation has progressed dramatically in recent years. The new digital revolution, mostly known as Industry 4.0, introduces impressive changes in the way enterprises and organizations are operating in a globalized world and altering the well-established lifestyle of a society. Therefore, it is of utmost importance to identify the current capabilities of companies in the context of Industry 4.0. Current literature on Industry 4.0 maturity and assessment models underlies the importance of a proper development strategy with exact steps to perform. Design principles address the issue of systematizing the measurable and attainable steps for further development. The present study contributes towards the identification of the research gap in the presence of core Industry 4.0 design principles during the development of maturity models. The analysis of 12 chosen maturity models by eight core design principles was provided. This research can serve as a starting point for the development of a complex strategic roadmap and thereby to provide a successful transition from traditional manufacturing into Industry 4.0.
Are Central Government Rules Okay? Assessing the Hidden Costs of Centralised Discipline for Municipal Borrowing
Authors: Eltrudis Davide , Monfardini Patrizio
Published: November 2020

In the EU, the specialty municipal banks have been the traditional funding source besides tax sharing and governmental transfers for Local Governments (LGs). With the decentralization process, LGs experienced different market-based options so that banks were no longer the only source of funding. However, with the onset of the Eurozone crisis, public sector debt is no more risk-free, and the cost of borrowing became unstable over time. To minimise such risks, Central Governments forced LGs to adopt general principles of control of local borrowing. Previous studies evidenced that centralised controls affect unitary countries more than federations. This paper investigates the Centralised Discipline and Control Model to understand whether it generates hidden costs. For such a purpose, the paper compares municipal bonds against borrowing from banks in Italy, a European unitary country. This paper highlights the existence of hidden costs for Italian LGs because the Central Government set up an expensive system for controlling the entire public sector debt. Policy makers should pay particular attention to which model of control to adopt by considering their country’s specific characteristics and the potential impacts of the different models on them, according to the present economic circumstances.
Assessing Green Space Potential Accessibility through Urban Artificial Building Data in Nanjing, China
Authors: Du Xindong , Zhang Xiaoke , Wang Huan , Zhi Xiaojuan , Huang Jianyuan
Published: November 2020

Green spaces play an important role in improving the health and quality of life of urban residents, and environmental justice has become one of the most debated topics for scholars and governments in China. The accessibility of green space has been recognized as an effective method for the assessment of environmental justice. Population and green space are the two basic elements for evaluating green space accessibility. However, high-precision population data are difficult to obtain. To address this issue, we propose a straightforward method to assess green space accessibility using urban artificial building data and investigate how green space distribution is correlated with the population. Our analysis uses urban artificial building data and green space data from 2018 in Nanjing, China. The results show that the overall amount of green space, is not only very low, but also unevenly distributed. From the urban center to the city outskirts, the green space changed representing an M-shaped pattern, while the population sharply declined. Given the serious mismatch between the population and green space, only about 26.4% and 51.8% of Nanjing residents could access green space within 400 and 800 m, respectively, which was far below that in cities in developed countries. For residents’ wellbeing, governments must consider increasing green space provision and promoting equal access.
Implementation of Life Cycle Based Tools in the Circular Economy Context—Case Study of Plastic Waste
Authors: Joachimiak-Lechman Katarzyna , Garstecki Dawid , Konopczyński Marcin , Lewandowska Anna
Published: November 2020

This article describes research done within the CIRCE2020 project, implemented under the Interreg CENTRAL EUROPE 2014–2020 Programme. The main aim is to present the results of a life cycle assessment (LCA) and life cycle costing (LCC) carried out for a recycling plant in Wielkopolska. From the LCA perspective, the analyzed recycling plant performs two functions; therefore, two research approaches were adopted: from the final waste management perspective (Approach 1) and from the production of secondary products (Approach 2). From the first perspective, the total environmental impact for the reference flow (215.140 kg of multi-material waste) was 552.32 Pt. When focused on the second perspective, the environmental impact for the production of plastic boards (3.073 boards) reached 659.58 Pt. The difference in the obtained values results from the fact that the second analysis, besides waste processing, included additionally the generation of raw materials corrected by the quality factor. The total production cost of boards made of multi-material waste was PLN 165,957.23. Energy consumption is the main cost-generating element of production and also the most important environmental hot spot. To increase environmental efficiency and reduce costs, the use of technology allowing for the reduction of energy demand should be considered first.
Influence of the COVID-19 Pandemic on Household Food Waste Behavior in Japan
Authors: Qian Kun , Javadi Firouzeh , Hiramatsu Michikazu
Published: November 2020

The 2019 coronavirus disease (COVID-19) pandemic had various influences on people’s ordinary lives, including their thoughts and behaviors related to food consumption. Food waste has been cited as a serious issue with environmental, social, and economic consequences. In this study, we investigated how the COVID-19 pandemic altered the social consciousness and behavior related to food waste in Japan. We conducted a nationwide online-based survey and collected a cross-sectional dataset from 1959 adult respondents. The results showed that people in regions highly impacted by the pandemic reported a clearer understanding of the situation of their household food waste, more careful food preparation and purchasing, and were more strongly influenced to change their behaviors due to COVID-19. Further analyses revealed that thoughts and behaviors related to food waste significantly differed by sociodemographic characteristics, such as gender, household size, and employment status. This study also implied that the COVID-19 pandemic encouraged some improvements in peoples’ behaviors and thoughts with regard to food, such as paying attention to food waste, making efforts to reduce food waste, and attempting cooking by themselves at home.
Stability of Maximum Functional Equation and Some Properties of Groups
Authors: Sarfraz Muhammad , Liu Qi , Li Yongjin
Published: November 2020

In this research paper, we deal with the problem of determining the function χ:G→R, which is the solution to the maximum functional equation (MFE) max{χ(xy),χ(xy−1)}=χ(x)χ(y), when the domain is a discretely normed abelian group or any arbitrary group G. We also analyse the stability of the maximum functional equation max{χ(xy),χ(xy−1)}=χ(x)+χ(y) and its solutions for the function χ:G→R, where G be any group and also investigate the connection of the stability with commutators and free abelian group K that can be embedded into a group G.
Point Cloud Coding Solutions, Subjective Assessment and Objective Measures: A Case Study
Authors: Dumic Emil , da Silva Cruz Luis A.
Published: November 2020

This paper presents a summary of recent progress in compression, subjective assessment and objective quality measures of point cloud representations of three dimensional visual information. Different existing point cloud datasets, as well as discusses the protocols that have been proposed to evaluate the subjective quality of point cloud data. Several geometry and attribute point cloud data objective quality measures are also presented and described. A case study on the evaluation of subjective quality of point clouds in two laboratories is presented. Six original point clouds degraded with G-PCC and V-PCC point cloud compression and five degradation levels were subjectively evaluated, showing high inter-laboratory correlation. Furthermore, performance of several geometry-based objective quality measures applied to the same data are described, concluding that the highest correlation with subjective scores is obtained using point-to-plane measures. Finally, several current challenges and future research directions on point clouds compression and quality evaluation are discussed.
Scene Text Detection in Natural Images: A Review
Authors: Cao Dongping , Zhong Yong , Wang Lishun , He Yilong , Dang Jiachen
Published: November 2020

Scene text detection is attracting more and more attention and has become an important topic in machine vision research. With the development of mobile IoT (Internet of things) and deep learning technology, text detection research has made significant progress. This survey aims to summarize and analyze the main challenges and significant progress in scene text detection research. In this paper, we first introduce the history and progress of scene text detection and classify the traditional methods and deep learning-based methods in detail, pointing out the corresponding key issues and techniques. Then, we introduce commonly used benchmark datasets and evaluation protocols and identify state-of-the-art algorithms by comparison. Finally, we summarize and predict potential future research directions.
Sustainable Decision Making Using a Consensus Model for Consistent Hesitant Fuzzy Preference Relations—Water Allocation Management Case Study
Authors: Rehman Atiq-ur , Wątróbski Jarosław , Faizi Shahzad , Rashid Tabasam , Tarczyńska-Łuniewska Małgorzata
Published: November 2020

This paper presents an improved consensus-based procedure to handle multi-person decision making (MPDM) using hesitant fuzzy preference relations (HFPRs) which are not in normal format. At the first level, we proposed a ukasiewicz transitivity (TL-transitivity) based scheme to get normalized hesitant fuzzy preference relations (NHFPRs), subject to which, a consensus-based model is established. Then, a transitive closure formula is defined to construct TL-consistent HFPRs and creates symmetrical matrices. Following this, consistency analysis is made to estimate the consistency degrees of the information provided by the decision-makers (DMs), and consequently, to assign the consistency weights to them. The final priority weights vector of DMs is calculated after the combination of consistency weights and predefined priority weights (if any). The consensus process concludes whether the aggregation of data and selection of the best alternative should be originated or not. The enhancement mechanism is indulged in improving the consensus measure among the DMs, after introducing an identifier used to locate the weak positions, in case of the poor consensus reached. In the end, a comparative example reflects the applicability and the efficiency of proposed scheme. The results show that the proposed method can offer useful comprehension into the MPDM process.
Experimental Performance Analysis of a Small Thermoelectric System Applicable to Real-Time PCR Devices
Authors: Chung Jae Hoon , Jeong Sehoon
Published: November 2020

At the International Space Station (ISS), not only observation of the space environment, but also biological and medical research under weightlessness has been conducted. The efficient use of energy from waste heat from the ISS away from the Earth is very important to the efficient operation of the ISS. To develop a thermoelectric module that can be used for real-time polymerase chain reaction (PCR) machinery used in biological and medical research, we simulated and evaluated the thermoelectric waste heat recovery system. Specifically, the thermoelectric module was attached to a stainless steel duct, and a hot air blower was faced with the duct inlet. The power of the thermoelectric system was measured by controlling the temperature of the hot air inlet. Additionally, the thermoelectric performance was evaluated according to the heat sink attached to the cold side of the thermoelectric module. Here, we also found the optimal heat exchange factors to improve the power and efficiency of the thermoelectric module. In this regard, it is expected that the thermoelectric module development and analysis study using waste heat will play an important role in the biological and medical research that is being conducted at ISS by developing a real-time PCR utilizing it.
Tetrodotoxin and Its Analogues in Cephalothrix cf. simula (Nemertea: Palaeonemertea) from the Sea of Japan (Peter the Great Gulf): Intrabody Distribution and Secretions
Authors: Vlasenko Anna E. , Magarlamov Timur Yu.
Published: November 2020

Some nemertean species from the genus Cephalothrix accumulate tetrodotoxin (TTX) in extremely high concentrations. The current study is the first to provide high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) data on tetrodotoxin and its analogues (TTXs) profile and concentration in different regions and organs of Cephalothrix cf. simula, and its secretions produced in response to stimulation. Different specimens of C. cf. simula possessed 7–11 analogues, including nine previously found in this species and two new for nemerteans—4,9-anhydro-8-epi-5,6,11-trideoxyTTX and 1-hydroxy-8-epi-5,6,11-trideoxyTTX. The study of the toxins’ distribution in different regions and organs of nemerteans revealed the same qualitative composition of TTXs throughout the body but differences in the total concentration of the toxins. The total concentration of TTXs was highest in the anterior region of the body and decreased towards the posterior; the ratio of the analogues also differed between regions. The data obtained suggest a pathway of TTXs uptake in C. cf. simula and the role of toxins in the life activity of nemerteans.
Ligand-Based Virtual Screening, Molecular Docking, Molecular Dynamics, and MM-PBSA Calculations towards the Identification of Potential Novel Ricin Inhibitors
Authors: Botelho Fernanda D. , dos Santos Marcelo C. , Gonçalves Arlan da S. , Kuca Kamil , Valis Martin , LaPlante Steven R. , França Tanos C. C. , de Almeida Joyce S. F. D.
Published: November 2020

Ricin is a toxin found in the castor seeds and listed as a chemical weapon by the Chemical Weapons Convention (CWC) due to its high toxicity combined with the easiness of obtention and lack of available antidotes. The relatively frequent episodes of usage or attempting to use ricin in terrorist attacks reinforce the urge to develop an antidote for this toxin. In this sense, we selected in this work the current RTA (ricin catalytic subunit) inhibitor with the best experimental performance, as a reference molecule for virtual screening in the PubChem database. The selected molecules were then evaluated through docking studies, followed by drug-likeness investigation, molecular dynamics simulations and Molecular Mechanics Poisson–Boltzmann Surface Area (MM-PBSA) calculations. In every step, the selection of molecules was mainly based on their ability to occupy both the active and secondary sites of RTA, which are located right next to each other, but are not simultaneously occupied by the current RTA inhibitors. Results show that the three PubChem compounds 18309602, 18498053, and 136023163 presented better overall results than the reference molecule itself, showing up as new hits for the RTA inhibition, and encouraging further experimental evaluation.
Current Immunotherapy Approaches in Non-Hodgkin Lymphomas
Authors: Pytlik Robert , Polgarova Kamila , Karolova Jana , Klener Pavel
Published: November 2020

Non-Hodgkin lymphomas (NHLs) are lymphoid malignancies of B- or T-cell origin. Despite great advances in treatment options and significant improvement of survival parameters, a large part of NHL patients either present with a chemotherapy-refractory disease or experience lymphoma relapse. Chemotherapy-based salvage therapy of relapsed/refractory NHL is, however, capable of re-inducing long-term remissions only in a minority of patients. Immunotherapy-based approaches, including bispecific antibodies, immune checkpoint inhibitors and genetically engineered T-cells carrying chimeric antigen receptors, single-agent or in combination with therapeutic monoclonal antibodies, immunomodulatory agents, chemotherapy or targeted agents demonstrated unprecedented clinical activity in heavily-pretreated patients with NHL, including chemotherapy-refractory cases with complex karyotype changes and other adverse prognostic factors. In this review, we recapitulate currently used immunotherapy modalities in NHL and discuss future perspectives of combinatorial immunotherapy strategies, including patient-tailored approaches.
Advancing Collaborative Water Governance: Unravelling Stakeholders’ Relationships and Influences in Contentious River Basins
Authors: Rojas Rodrigo , Bennison Gabriella , Gálvez Victor , Claro Edmundo , Castelblanco Gabriel
Published: November 2020

Collaborative water governance (CWG) has emerged as a promising framework to tackle water management challenges. Simple identification of participants however is not enough to unravel the intricacies of stakeholders’ interlinkages, roles and influences for robust CWG. A clear understanding of the stakeholders’ landscape is therefore required to underpin CWG. In this work, we combine stakeholder analysis (SA), social network analysis (SNA) and participatory processes (PP) under a theoretical collaborative governance framework to advance CWG in the contentious Rapel River Basin (RRB), Chile. By combining these techniques, we identified a cohort of leading (and secondary) stakeholders, their relationships and critical roles on basin-wide CWG-enabling networks (collaborative ties, information flows and financial exchanges) and their influence to achieve a shared vision for water planning. The results show members of this cohort perform critical roles (bridging, connecting and gatekeeping) across the networks and in influencing explicit elements of the shared vision. Specific CWG-enabling networks properties indicate a weak adaptive capacity of stakeholders to deal with potential water management challenges and strong prospects for sharing innovative ideas/solutions and achieving long-term water planning goals. A major CWG implementation challenge in the RRB is the lack of a leading organisation. One way forward would be formally organising stakeholders of the identified cohort to advance CWG in the RRB. By implementing the methodological framework, we facilitated social learning, fostered trust among stakeholders and mobilised efforts towards implementing CWG in practice in the contentious RRB.
Correlating Microbial Community Characteristics with Environmental Factors along a Two-Stage Biological Aerated Filter
Authors: An Yuchen , Li Songmin , Wang Xiaoling , Liu Yuyang , Wang Ruonan
Published: November 2020

The purification effect of a biological aerated filter (BAF) mainly comes from the microorganisms in the reactor. Understanding the correlation between microbial community characteristics and environmental factors along the filter has great significance for maintaining good operation and improving the removal efficiency of the filter. A two-stage BAF was employed to treat domestic sewage under organic loads of 1.02 and 1.55 kg/m3·d for 15 days each. 16S rDNA high-throughput sequencing technology and redundancy analysis were applied to explore the correlation between microbial community characteristics and environmental variables. The results showed that: (1) the crucial organic-degrading bacteria in the A-stage filter were of the genus Novosphingobium, which had a significant increase in terms of relative abundance at sampling outlet A3 (135 cm of the filling height) after the increase of organic load; (2) the microbial communities at different positions in the B-stage filter were similarly affected by environmental factors, and the main bacteria associated with nitrogen removal in the B-stage filter were Zoogloea and Rhodocyclus; and (3) to improve the pollutant removal performance of this two-stage biological aerated filter, a strategy of adding an internal circulation in the B-stage filter can be adopted.
Available Dissolved Organic Carbon Alters Uptake and Recycling of Phosphorus and Nitrogen from River Sediments
Authors: Stutter Marc , Graeber Daniel , Weigelhofer Gabriele
Published: November 2020

Concurrent with nutrient pollution, agriculture has significantly impacted the quantity, composition, and bioavailability of catchment-derived dissolved organic carbon (DOC) in stream ecosystems. Based on the stoichiometric theory, we tested the hypothesis that bioavailable DOC will stimulate the heterotrophic uptake of soluble reactive P (SRP) and inorganic nitrogen in stream sediments. In a simplified laboratory column flow-through study, we exposed stream sediments to additions of glucose, nitrate, and phosphate alone and in combination (+C, +NP, +CNP), and calculated gross and net changes in DOC and nutrients via a mass balance approach. Our results show that glucose-C increased nutrient uptake, but also that NP additions resulted in the enhanced consumption of both native and added organic C. The effects of C addition were stronger on N than P uptake, presumably because labile C stimulated both assimilation and denitrification, while part of the P uptake was due to adsorption. Internal cycling affected net nutrient uptake due to losses of dissolved organically-complexed P and N (DOP and DON). Overall, our study shows that increases in the stoichiometric availability of organic carbon can stimulate N and P sequestration in nutrient-polluted stream sediments. Future studies are required to assess the effects of complex organic carbon sources on nutrient uptake in stream sediments under different environmental conditions, and whether these stoichiometric relations are relevant for ecosystem management.
The Long-Term and Retention Impacts of the Intervention Policy for Cage Aquaculture on the Reservoir Water Qualities in Northern China
Authors: Kang Gelin , Yin Jingchen , Cui Naixin , Ding Han , Wang Shaoming , Wang Yuqiu , Qi Zuoda
Published: November 2020

To ensure the safety of the water supply of the Panjiakou reservoir, in 2016, the Chinese central government comprehensively banned the fishing cage culture that had lasted for almost 30 years. However, the long-term effects and retention impacts of the government’s mandatory intervention on the reservoir water quality are unknown. To determine the reservoir water quality, we employed statistical methods along with the mathematical model to investigate the internal relationship since the construction of the reservoir. We applied seasonal trend decomposition using loess (STL) to explore the long-term and seasonality trend of monthly total nitrogen (TN) and total phosphorous (TP). To separate the impact of upstream water quality changes from cage culture on reservoir water quality, we employed generalized additive models (GAMs). We created a model, the LAKE2K model, to investigate the internal sources of the sediment that accumulated during the aquaculture period and its retardant effect. The results revealed that the concentration of upstream TN was more affected by non-point sources than by TP. The long-term policy of encouraging aquaculture has greatly contributed to the increase in the reservoir TP concentration rather than an increase in TN; the prohibition of cage aquaculture has resulted in a sharp drop in TP. After the ban, the sediment became the main source of TP. We suspect that the TP concentration of the reservoir and sediment will decrease gradually until a new equilibrium is reached within 10 years. This study offers lake managers an opportunity to increase their insight into the interaction of management measures with water quality and provides valuable information for the natural recovery of the eutrophic system.
Experimental Research and Numerical Analysis of Flow Phenomena in Discharge Object with Siphon
Authors: Sedlář Milan , Procházka Pavel , Komárek Martin , Uruba Václav , Skála Vladislav
Published: November 2020

This article presents results of the experimental research and numerical simulations of the flow in a pumping system’s discharge object with the welded siphon. The laboratory simplified model was used in the study. Two stationary flow regimes characterized by different volume flow rates and water level heights have been chosen. The study concentrates mainly on the regions below and behind the siphon outlet. The mathematical modelling using advanced turbulence models has been performed. The free-surface flow has been carried out by means of the volume-of-fluid method. The experimental results obtained by the particle image velocimetry method have been used for the mathematical model validation. The evolution and interactions of main flow structures are analyzed using visualizations and the spectral analysis. The presented results show a good agreement of the measured and calculated complex flow topology and give a deep insight into the flow structures below and behind the siphon outlet. The presented methodology and results can increase the applicability and reliability of the numerical tools used for the design of the pump and turbine stations and their optimization with respect to the efficiency, lifetime and environmental demands.
Distributions of Microplastics in Surface Water, Fish, and Sediment in the Vicinity of a Sewage Treatment Plant
Authors: Park Tae-Jin , Lee Seung-Hyun , Lee Myung-Sung , Lee Jae-Kwan , Park Ji-Hyoung , Zoh Kyung-Duk
Published: November 2020

Microplastics are ubiquitously found in freshwater and marine environments worldwide. In particular, wastewater treatment plants (WWTPs) or sewage treatment plants (STPs) have been recognized as a main source of microplastics in the receiving freshwater. However, only a few studies have been conducted to examine the impact of these facilities on receiving waters. In this study, we investigated the distribution of microplastics in surface water, fish, and sediment near a sewage treatment plant (STP) in the Tanchon stream, one of the main tributaries flowing into the Han River, Korea. The concentration of microplastics in water varied spatially and temporarily, ranging between 5.3 and 87.3 particles/m3 (31.4 ± 28.5 particles/m3). In fish, the concentration in upstream and downstream sites was 7.3 ± 7.3 and 12.4 ± 17.9 particles/fish, respectively. Spatially, the downstream site was the most polluted with microplastics in water and fish. The concentration of microplastics was positively correlated with fish body length and weight. In sediment, microplastic concentration in upstream and downstream sites was 493.1 ± 136.0 and 380.0 ± 144.2 particles/kg, respectively. The contribution of upstream to the microplastic load in downstream was 15.8% in dry season (April), which was higher than that of STP effluent and Yangjaechon creek. Meanwhile, the highest load was observed in STP effluent (5.1%) in rainy season (August). Microplastics were more abundant in water in the rainy season (37.4 ± 37.0 particles/m3) than in the dry season (28.2 ± 22.2 particles/m3). Polyethylene (49%) and polypropylene (18%) were the most abundant polymer types in water, fish, and sediment. Regarding shape of microplastics, fragments were dominant (95%) over fiber and film in water, fish, and sediment.
Drying Behavior and Sensory Quality of Yellowfin Tuna (Thunnus albacares) Skin Using Vertical-type Mechanical Dryer
Authors: Pantuhan Guillermo Pana
Published: November 2020

The general objective of this study was to determine the drying behavior of yellowfin tuna (Thunnus albacares) skin as benchmark research for processing tuna skin as food material. The drying temperature of 47±3°C and airflow rates of 0.95m/s and 0.80m/s were used. The target moisture content of 10.00% w.b. for the final product was attained from an initial moisture content of 61.86% w.b. Result shows that the drying rate was initially faster for 0.95m/s air velocity than at 0.80m/s. At 1.50hrs, case-hardening was observed for 0.95m/s so that drying became slower. Consequently, reaching the final moisture content took a longer time at 0.95m/s. This lead to significant differences in both drying time and drying rate, with better drying characteristics at a slower airflow rate of 0.80m/s. The findings of the study can be used to design a more energy-efficient system of processing tuna skin at mild drying conditions.