bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptome-Wide Analysis for Ginsenoside Rb3 Synthesis-Related Genes and Study on the Expression of Methyl Jasmonate Treatment in Panax ginseng
Authors: Wang Kangyu , Zhang Zixuan , Li Shaokun , Hu Jian , Liu Tao , Jiang Yang , Wu Jun , Lu Minghai , Zhao Mingzhu , Li Li , Zhu Lei , Wang Yanfang , Wang Yi , Zhang Meiping
Published: April 2021

Panax ginseng C. A. Meyer is a kind of renascent herb that belongs to the genus Panax in the family Araliaceae. It is a traditional Chinese precious herbal medicine with a long history of medicinal use. Ginsenoside Rb3 is one of the important active ingredients in ginseng and has important physiological activity in the treatment of many diseases. In this study, we screened and systematically analyzed the candidate genes related to ginsenoside Rb3 synthesis through bioinformatics methods; discussed the functions, expression patterns, and interactions of the genes related to ginsenoside Rb3 synthesis; and finally, selected seven genes, mainly PgRb3, that directly contribute to the synthesis of ginsenoside Rb3. This study provides a reference for revealing the expression rules of ginsenoside Rb3 synthesis-related genes and elucidating the regulatory mechanism of methyl jasmonate, lays a theoretical foundation for the research of ginsenoside Rb3 synthesis, and provides theoretical and technical support for the factory production of ginsenoside monomer saponins.
T-Growth Stochastic Model: Simulation and Inference via Metaheuristic Algorithms
Authors: Barrera Antonio , Román-Román Patricia , Torres-Ruiz Francisco
Published: April 2021

The main objective of this work is to introduce a stochastic model associated with the one described by the T-growth curve, which is in turn a modification of the logistic curve. By conveniently reformulating the T curve, it may be obtained as a solution to a linear differential equation. This greatly simplifies the mathematical treatment of the model and allows a diffusion process to be defined, which is derived from the non-homogeneous lognormal diffusion process, whose mean function is a T curve. This allows the phenomenon under study to be viewed in a dynamic way. In these pages, the distribution of the process is obtained, as are its main characteristics. The maximum likelihood estimation procedure is carried out by optimization via metaheuristic algorithms. Thanks to an exhaustive study of the curve, a strategy is obtained to bound the parametric space, which is a requirement for the application of various swarm-based metaheuristic algorithms. A simulation study is presented to show the validity of the bounding procedure and an example based on real data is provided.
An Enhanced DC-Link Voltage Response for Wind-Driven Doubly Fed Induction Generator Using Adaptive Fuzzy Extended State Observer and Sliding Mode Control
Authors: Alhato Mohammed Mazen , Ibrahim Mohamed N. , Rezk Hegazy , Bouallègue Soufiene
Published: April 2021

This paper presents an enhancement method to improve the performance of the DC-link voltage loop regulation in a Doubly-Fed Induction Generator (DFIG)- based wind energy converter. An intelligent, combined control approach based on a metaheuristics-tuned Second-Order Sliding Mode (SOSM) controller and an adaptive fuzzy-scheduled Extended State Observer (ESO) is proposed and successfully applied. The proposed fuzzy gains-scheduling mechanism is performed to adaptively tune and update the bandwidth of the ESO while disturbances occur. Besides common time-domain performance indexes, bounded limitations on the effective parameters of the designed Super Twisting (STA)-based SOSM controllers are set thanks to the Lyapunov theory and used as nonlinear constraints for the formulated hard optimization control problem. A set of advanced metaheuristics, such as Thermal Exchange Optimization (TEO), Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Harmony Search Algorithm (HSA), Water Cycle Algorithm (WCA), and Grasshopper Optimization Algorithm (GOA), is considered to solve the constrained optimization problem. Demonstrative simulation results are carried out to show the superiority and effectiveness of the proposed control scheme in terms of grid disturbances rejection, closed-loop tracking performance, and robustness against the chattering phenomenon. Several comparisons to our related works, i.e., approaches based on TEO-tuned PI controller, TEO-tuned STA-SOSM controller, and STA-SOSM controller-based linear observer, are presented and discussed.
General Bivariate Appell Polynomials via Matrix Calculus and Related Interpolation Hints
Authors: Costabile Francesco Aldo , Gualtieri Maria Italia , Napoli Anna
Published: April 2021

An approach to general bivariate Appell polynomials based on matrix calculus is proposed. Known and new basic results are given, such as recurrence relations, determinant forms, differential equations and other properties. Some applications to linear functional and linear interpolation are sketched. New and known examples of bivariate Appell polynomial sequences are given.
DICER 2.0: A New Model Checker for Data-Flow Errors of Concurrent Software Systems
Authors: Xiang Dongming , Zhao Fang , Liu Yaping
Published: April 2021

Petri nets are widely used to model concurrent software systems. Currently, there are many different kinds of Petri net tools that can analyze system properties such as deadlocks, reachability and liveness. However, most tools are not suitable to analyze data-flow errors of concurrent systems because they do not formalize data information and lack efficient computing methods for analyzing data-flows. Especially when a concurrent system has so many concurrent data operations, these Petri net tools easily suffer from the state–space explosion problem and pseudo-states. To alleviate these problems, we develop a new model checker DICER 2.0. By using this tool, we can model the control-flows and data-flows of concurrent software systems. Moreover, the errors of data inconsistency can be detected based on the unfolding techniques, and some model-checking can be done via the guard-driven reachability graph (GRG). Furthermore, some case studies and experiments are done to show the effectiveness and advantage of our tool.
Thermal Decomposition Kinetics of Rare Earth Minerals in Tailings with Addition of MgO
Authors: Zhou Yan , Song Shizhe , Liu Jianxing , Cheng Gongjin , Yang He , Xue Xiangxin
Published: April 2021

Due to the advantage in deactivating fluorine and enhancing the decomposition of rare earth (RE) minerals, MgO was applied to the magnetizing roasting of Bayan Obo tailings in this work. The effects of MgO dosages, roasting temperature, and holding time on the decomposition rate of RE minerals were experimentally studied. With a MgO dosage of 10 wt.%, the decomposition rate of RE minerals reached 98.09% at 750 °C. The phase composition of roasted samples was characterized by XRD and SEM-EDS. The incomplete decomposition rate was investigated with the observation of leaching residual by SEM-EDS. The decomposition kinetics of the RE minerals with the addition of MgO was analyzed with the Ginstling-Brundshtein model, where the reaction rate was controlled by chemical reaction.
Tribological Properties of Micro-Groove Cemented Carbide by Laser Processing
Authors: Zheng Guoqiang , Lin Youxi
Published: April 2021

Tool wear is the main factor of tool failure in cutting difficult-to-machine materials. This paper aims to analyze the anti-friction mechanism of laser machining micro-groove cemented carbide. Firstly, micro-grooves were prepared on the cemented carbide surface by laser processing. Secondly, we conducted an analysis of the mechanical properties of laser texturing by measuring hardness. Finally, we studied the anti-friction mechanism of micro-grooves by a wear test (ASTM G133-05). Results show that surface hardness increases after laser treatment. The friction coefficient and surface wear of micro-groove cemented carbide are significantly reduced compared with the conventional surface. The friction coefficient of PE and OB decreased by 20.6% and 10.7%, respectively. It is found that the direction of micro-grooves determines whether metal debris can be removed—the stronger the ability to remove metal debris, the better the tribological properties of the micro-groove surface.
Microsphere-Based Microfluidic Device for Plasma Separation and Potential Biochemistry Analysis Applications
Authors: Xu Hongyan , Wu Zhangying , Deng Jinan , Qiu Jun , Hu Ning , Gao Lihong , Yang Jun
Published: April 2021

The development of a simple, portable, and cost-effective plasma separation platform for blood biochemical analysis is of great interest in clinical diagnostics. We represent a plasma separation microfluidic device using microspheres with different sizes as the separation barrier. This plasma separation device, with 18 capillary microchannels, can extract about 3 μL of plasma from a 50 μL blood sample in about 55 min. The effects of evaporation and the microsphere barrier on the plasma biochemical analysis results were studied. Correction factors were applied to compensate for these two effects. The feasibility of the device in plasma biochemical analysis was validated with clinical blood samples.
Impact of Diagenesis on the Low Permeability Sandstone Reservoir: Case Study of the Lower Jurassic Reservoir in the Niudong Area, Northern Margin of Qaidam Basin
Authors: Li Wenhuan , Fan Tailiang , Gao Zhiqian , Wu Zhixiong , Li Ya’nan , Zhang Xinlei , Zhang Heng , Cao Fangda
Published: April 2021

The Lower Jurassic reservoir in the Niudong area of the northern margin of Qaidam Basin is a typical low permeability sandstone reservoir and an important target for oil and gas exploration in the northern margin of the Qaidam Basin. In this paper, casting thin section analysis, scanning electron microscopy, X-ray diffraction, and stable isotope analysis among other methods were used to identify the diagenetic characteristics and evolution as well as the main factors influencing reservoir quality in the study area. The predominant types of sandstone in the study area are mainly feldspathic lithic sandstone and lithic arkose, followed by feldspathic sandstone and lithic sandstone. Reservoir porosity ranges from 0.01% to 19.5% (average of 9.9%), and permeability ranges from 0.01 to 32.4 mD (average of 3.8 mD). The reservoir exhibits robust heterogeneity and its quality is mainly influenced by diagenesis. The Lower Jurassic reservoir in the study area has undergone complex diagenesis and reached the middle diagenesis stage (A–B). The quantitative analysis of pore evolution showed that the porosity loss rate caused by compaction and cementation was 69.0% and 25.7% on average, and the porosity increase via dissolution was 4.8% on average. Compaction was the main cause of the reduction in the physical property of the reservoir in the study area, while cementation and dissolution were the main causes of reservoir heterogeneity. Cementation can reduce reservoir space by filling primary intergranular pores and secondary dissolved pores via cementation such as a calcite and illite/smectite mixed layer, whereas high cement content increased the compaction resistance of particles to preserve certain primary pores. δ13C and δ18O isotopes showed that the carbonate cement in the study area was the product of hydrocarbon generation by organic matter. The study area has conditions that are conductive to strong dissolution and mainly occur in feldspar dissolution, which produces a large number of secondary pores. It is important to improve the physical properties of the reservoir. Structurally, the Niudong area is a large nose uplift structure with developed fractures, which can be used as an effective oil and gas reservoir space and migration channel. In addition, the existence of fractures provides favorable conditions for the uninterrupted entry of acid fluid into the reservoir, promoting the occurrence of dissolution, and ultimately improves the physical properties of reservoirs, which is mainly manifested in improving the reservoir permeability.
Editorial for Special Issue: Anthocyanin
Authors: Silva Paula , Mosca Luciana
Published: April 2021

What do jabuticaba (Myrciaria jaboticaba), Jamun berry (Syzygium cumini), Malay apple (Syzygium malaccense), crimson glory vine (Vitis coignetiae) and roselle (Hibiscus sabdariffa) have in common [...]
Secretion of Mutant DNA and mRNA by the Exosomes of Breast Cancer Cells
Authors: Andreeva Olga E. , Shchegolev Yuri Y. , Scherbakov Alexander M. , Mikhaevich Ekaterina I. , Sorokin Danila V. , Gudkova Margarita V. , Bure Irina V. , Kuznetsova Ekaterina B. , Mikhaylenko Dmitry S. , Nemtsova Marina V. , Bagrov Dmitry V. , Krasil’nikov Mikhail A.
Published: April 2021

Exosomes are the small vesicles that are secreted by different types of normal and tumour cells and can incorporate and transfer their cargo to the recipient cells. The main goal of the present work was to study the tumour exosomes’ ability to accumulate the parent mutant DNA or RNA transcripts with their following transfer to the surrounding cells. The experiments were performed on the MCF7 breast cancer cells that are characterized by the unique coding mutation in the PIK3CA gene. Using two independent methods, Sanger sequencing and allele-specific real-time PCR, we revealed the presence of the fragments of the mutant DNA and RNA transcripts in the exosomes secreted by the MCF7 cells. Furthermore, we demonstrated the MCF7 exosomes’ ability to incorporate into the heterologous MDA-MB-231 breast cancer cells supporting the possible transferring of the exosomal cargo into the recipient cells. Sanger sequencing of the DNA from MDA-MB-231 cells (originally bearing a wild type of PIK3CA) treated with MCF7 exosomes showed no detectable amount of mutant DNA or RNA; however, using allele-specific real-time PCR, we revealed a minor signal from amplification of a mutant allele, showing a slight increase of mutant DNA in the exosome-treated MDA-MB-231 cells. The results demonstrate the exosome-mediated secretion of the fragments of mutant DNA and mRNA by the cancer cells and the exosomes’ ability to transfer their cargo into the heterologous cells.
Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities
Authors: Talib Wamidh H. , Alsayed Ahmad Riyad , Abuawad Alaa , Daoud Safa , Mahmod Asma Ismail
Published: April 2021

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.
Cellulose Paper Modified by a Zinc Oxide Nanosheet Using a ZnCl2-Urea Eutectic Solvent for Novel Applications
Authors: Lin Changmei , Chen Duo , Hua Zifeng , Wang Jun , Cao Shilin , Ma Xiaojuan
Published: April 2021

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation.
Soft Sensor Development for Real-Time Process Monitoring of Multidimensional Fractionation in Tubular Centrifuges
Authors: Winkler Marvin , Gleiss Marco , Nirschl Hermann
Published: April 2021

High centrifugal acceleration and throughput rates of tubular centrifuges enable the solid–liquid size separation and fractionation of nanoparticles on a bench scale. Nowadays, advantageous product properties are defined by precise specifications regarding particle size and material composition. Hence, there is a demand for innovative and efficient downstream processing of complex particle suspensions. With this type of centrifuge working in a semi-continuous mode, an online observation of the separation quality is needed for optimization purposes. To analyze the composition of fines downstream of the centrifuge, a UV/vis soft sensor is developed to monitor the sorting of polymer and metal oxide nanoparticles by their size and density. By spectroscopic multi-component analysis, a measured UV/vis signal is translated into a model based prediction of the relative solids volume fraction of the fines. High signal stability and an adaptive but mandatory calibration routine enable the presented setup to accurately predict the product’s composition at variable operating conditions. It is outlined how this software-based UV/vis sensor can be utilized effectively for challenging real-time process analytics in multi-component suspension processing. The setup provides insight into the underlying process dynamics and assists in optimizing the outcome of separation tasks on the nanoscale.
The Role of Lifestyle, Eating Habits and Social Environment in the Prevention and Treatment of Type 2 Diabetes and Hypertension
Authors: Karatzi Kalliopi , Manios Yannis
Published: April 2021

Type 2 diabetes (T2DM) and hypertension are major health problems, with an undisputed growth burden in the past decades [...]
Hepatic Transcriptome Profiling Reveals Lack of Acsm3 Expression in Polydactylous Rats with High-Fat Diet-Induced Hypertriglyceridemia and Visceral Fat Accumulation
Authors: Junková Kristýna , Mirchi Lukáš F. , Chylíková Blanka , Janků Michaela , Šilhavý Jan , Hüttl Martina , Marková Irena , Miklánková Denisa , Včelák Josef , Malínská Hana , Pravenec Michal , Šeda Ondřej , Liška František
Published: April 2021

Metabolic syndrome (MetS) is an important cause of worldwide morbidity and mortality. Its complex pathogenesis includes, on the one hand, sedentary lifestyle and high caloric intake, and, on the other hand, there is a clear genetic predisposition. PD (Polydactylous rat) is an animal model of hypertriglyceridemia, insulin resistance, and obesity. To unravel the genetic and pathophysiologic background of this phenotype, we compared morphometric and metabolic parameters as well as liver transcriptomes among PD, spontaneously hypertensive rat, and Brown Norway (BN) strains fed a high-fat diet (HFD). After 4 weeks of HFD, PD rats displayed marked hypertriglyceridemia but without the expected hepatic steatosis. Moreover, the PD strain showed significant weight gain, including increased weight of retroperitoneal and epididymal fat pads, and impaired glucose tolerance. In the liver transcriptome, we found 5480 differentially expressed genes, which were enriched for pathways involved in fatty acid beta and omega oxidation, glucocorticoid metabolism, oxidative stress, complement activation, triacylglycerol and lipid droplets synthesis, focal adhesion, prostaglandin synthesis, interferon signaling, and tricarboxylic acid cycle pathways. Interestingly, the PD strain, contrary to SHR and BN rats, did not express the Acsm3 (acyl-CoA synthetase medium-chain family member 3) gene in the liver. Together, these results suggest disturbances in fatty acid utilization as a molecular mechanism predisposing PD rats to hypertriglyceridemia and fat accumulation.
New Phenolic Compounds in Posidonia oceanica Seagrass: A Comprehensive Array Using High Resolution Mass Spectrometry
Authors: Astudillo-Pascual Marina , Domínguez Irene , Aguilera Pedro A. , Garrido Frenich Antonia
Published: April 2021

The studies on the Posidonia oceanica Delile (P. oceanica) phenolic composition have been focused on the foliar tissues and have often neglected the phenolic compounds in rhizomes or roots alike. With the current improvements in high resolution mass spectrometry (HRMS) analyzers, such as the Orbitrap MS, there is a new opportunity to more deeply study P. oceanica. One of the benefits is the possibility of conducting an exhaustive phenolic monitoring, which is crucial in the search for new stressor-specific biomarkers of coastal deterioration. For this purpose, the different tissues (leaf, rhizome, and root) of P. oceanica seagrass from several marine sampling areas were analyzed through target, suspected, and non-target screenings. This paper brings a fast and tissues-specific extraction, as well as a detection method of phenolic compounds applying for the first time the potential of HRMS (Exactive Orbitrap) in P. oceanica samples. As a result, 42 phenolic compounds were satisfactorily detected, of which, to our knowledge, 24 were not previously reported in P. oceanica, such as naringenin, naringenin chalcone and pinocembrin, among others. Information here reported could be used for the evaluation of new stressor-specific biomarkers of coastal deterioration in the Mediterranean waters. Furthermore, the followed extraction and analytical method could be considered as a reference protocol in other studies on marine seagrasses due to the exhaustive search and satisfactory results.
Development of Polylactic Acid Thermoplastic Starch Formulations Using Maleinized Hemp Oil as Biobased Plasticizer
Authors: Lerma-Canto Alejandro , Gomez-Caturla Jaume , Herrero-Herrero María , Garcia-Garcia Daniel , Fombuena Vicent
Published: April 2021

In this study, hemp seed oil was reacted with maleic anhydride in an ene reaction to obtain maleinized hemp seed oil (MHO). The use of MHO as a plasticizer and compatibilizer has been studied for polylactic acid (PLA) and thermoplastic starch (TPS) blends (80/20, respectively). By mechanical, thermal and morphological characterizations, the addition of MHO provides a dual effect, acting as plasticizer and compatibilizer between these two partially miscible biopolymers. The addition of MHO up to 7.5 phr (parts by weight of MHO per hundred parts of PLA and TPS) revealed a noticeable increase in the ductile properties, reaching an elongation at break 155% higher than the PLA/TPS blend. Furthermore, contrary to what has been observed with maleinized oils such as linseed oil, the thermal properties do not decrease significantly as a result of the plasticizing effect, due to the compatibilizing behavior of the MHO and the natural antioxidants present in the oil. Finally, a disintegration test was carried out in aerobic conditions at 58 °C, for 24 days, to demonstrate that the incorporation of the MHO, although causing a slight delay, does not impair the biodegradability of the blend, obtaining total degradation in 24 days.
Exploring Religions in Relation to Populism: A Tour around the World
Authors: Yilmaz Ihsan , Morieson Nicholas , Demir Mustafa
Published: April 2021

This paper explores the emerging scholarship investigating the relationship between religion(s) and populism. It systematically reviews the various aspects of the phenomenon going beyond the Western world and discusses how religion and populism interact in various contexts around the globe. It looks at Islam, Hinduism, Buddhism, Judaism, and Christianity and how in different regions and cultural contexts, they merge with populism and surface as the bases of populist appeals in the 21st century. In doing so, this paper contends that there is a scarcity of literature on this topic particularly in the non-Western and Judeo-Christian context. The paper concludes with recommendations on various gaps in the field of study of religious populism.
Infrequent Pattern Detection for Reliable Network Traffic Analysis Using Robust Evolutionary Computation
Authors: Rashid A. N. M. Bazlur , Ahmed Mohiuddin , Pathan Al-Sakib Khan
Published: April 2021

While anomaly detection is very important in many domains, such as in cybersecurity, there are many rare anomalies or infrequent patterns in cybersecurity datasets. Detection of infrequent patterns is computationally expensive. Cybersecurity datasets consist of many features, mostly irrelevant, resulting in lower classification performance by machine learning algorithms. Hence, a feature selection (FS) approach, i.e., selecting relevant features only, is an essential preprocessing step in cybersecurity data analysis. Despite many FS approaches proposed in the literature, cooperative co-evolution (CC)-based FS approaches can be more suitable for cybersecurity data preprocessing considering the Big Data scenario. Accordingly, in this paper, we have applied our previously proposed CC-based FS with random feature grouping (CCFSRFG) to a benchmark cybersecurity dataset as the preprocessing step. The dataset with original features and the dataset with a reduced number of features were used for infrequent pattern detection. Experimental analysis was performed and evaluated using 10 unsupervised anomaly detection techniques. Therefore, the proposed infrequent pattern detection is termed Unsupervised Infrequent Pattern Detection (UIPD). Then, we compared the experimental results with and without FS in terms of true positive rate (TPR). Experimental analysis indicates that the highest rate of TPR improvement was by cluster-based local outlier factor (CBLOF) of the backdoor infrequent pattern detection, and it was 385.91% when using FS. Furthermore, the highest overall infrequent pattern detection TPR was improved by 61.47% for all infrequent patterns using clustering-based multivariate Gaussian outlier score (CMGOS) with FS.
Localized Bioimpedance Measurements with the MAX3000x Integrated Circuit: Characterization and Demonstration
Authors: Critcher Shelby , Freeborn Todd J.
Published: April 2021

The commercial availability of integrated circuits with bioimpedance sensing functionality is advancing the opportunity for practical wearable systems that monitor the electrical impedance properties of tissues to identify physiological features in support of health-focused applications. This technical note characterizes the performance of the MAX3000x (resistance/reactance accuracy, power modes, filtering, gains) and is available for on-board processing (electrode detection) for localized bioimpedance measurements. Measurements of discrete impedances that are representative of localized tissue bioimpedance support that this IC has a relative error of <10% for the resistance component of complex impedance measurements, but can also measure relative alterations in the 250 mΩ range. The application of the MAX3000x for monitoring localized bicep tissues during activity is presented to highlight its functionality, as well as its limitations, for multi-frequency measurements. This device is a very-small-form-factor single-chip solution for measuring multi-frequency bioimpedance with significant on-board processing with potential for wearable applications.
Machine Learning-Inspired Hybrid Precoding for mmWave MU-MIMO Systems with Domestic Switch Network
Authors: Li Xiang , Huang Yang , Heng Wei , Wu Jing
Published: April 2021

Hybrid precoding is an attractive technique in MU-MIMO systems with significantly reduced hardware costs. However, it still requires a complex analog network to connect the RF chains and antennas. In this paper, we develop a novel hybrid precoding structure for the downlink transmission with a compact RF structure. Specifically, the proposed structure relies on domestic connections instead of global connections to link RF chains and antennas. Fixed-degree phase shifters provide candidate signals, and simple on-off switches are used to route the signal to antennas, thus RF adders are no longer required. Baseband zero forcing and block diagonalization are used to cancel interference for single-antenna and multiple-antenna users, respectively. We formulate how to design the RF precoder by optimizing the probability distribution through cross-entropy minimization which originated in machine learning. To optimize the energy efficiency, we use the fractional programming technique and exploit the Dinkelbach method-based framework to optimize the number of active antennas. Simulation results show that proposed algorithms can yield significant advantages under different configurations.
Taking on the Institution: An Autoethnographic Account
Authors: Hodgins Margaret
Published: April 2021

The over-representation of men and the under-representation of women in senior positions in academic institutions is a familier and deep-rooted problem. While gender inequality in Higher Education Institutions has multiple causes, recruitment and internal promotion practices are particularly potent contributors to inequality regimes. This paper contains an autoethnographic account based on my failure to secure promotion and my subsequent legal action. It offers a personalized account of the experience of gender discrimination, in order to illuminate aspects of the culture of the Higher Educational Institution that contribute to this problem, and the challenges inherent in changing it. The theoretical perspective includes notions of organizational culture as gendered, drawing on the works of Louise Morley and Georgina Waylen, Pat O’Connor, Louise Chappel and Teresa Rees, as well as Carol Agócs work on institutionalized resistance to change, and theories of hidden and invisible power. The paper is a personal narrative autoethnography with self-reflection, adopting an analytic/interpretive approach. Based on an analysis of publicly available documents, personal journaling and media material, I identify four themes; (1) Slow Fuse burning, (2) From indifference to resistance, (3) Fixing me/Fixing women, (4) Solidarity. I conclude with reflections on the importance of seeing gender inequality and discrimination when it occurs and the importance of data in creating greater transparency that facilitates ‘seeing’. I also consider the importance of female anger and the importance of female solidarity.
I Am Niqabi: From Existential Unease to Cyber-Fundamentalism
Authors: Ainz-Galende Alexandra , Lozano-Díaz Antonia , Fernández-Prados Juan Sebastián
Published: April 2021

Currently, niqabi women are more and more visible, even in traditionally non-Muslim societies. However, there is a deep ignorance with regard to their worldview in general and about them in particular. The aim of this paper, which is based on a research carried out using the Grounded Theory, is to give answer to three fundamental questions: did niqabi women belonging to the Telegram channel Orgullo niqabi choose to become niqabis after experiencing some kind of crisis or existential unease? Has the grouping of these women in said channel contributed to the polarization of their posture on the niqab in some way? Additionally, if that is the case, has said polarization fueled or given rise to some ideology in particular? One of our conclusions, after conducting 27 in-depth interviews, is that most of these women opted for being niqabi and Muslim in response to the existential unease they experienced, which somehow kept them searching for some meaning in their lives. Another interesting aspect we have observed is that these women have reinforced their posture on the niqab, polarizing their perception in a fundamentalist way. Additionally, our third conclusion is that these women are cyber-fundamentalists, given that, besides the reactionary nature of their ideology, they construct it in a modern way.
Violence, Terrorism, and Identity Politics in Afghanistan: The Securitisation of Higher Education
Authors: Kaunert Christian , Sahar Arif
Published: April 2021

This article investigates the securitisation of the higher education sector in Afghanistan by examining ‘hidden’ non-discursive practices as opposed to overt discursive threat construction. Non-discursive practices are framed by the habitus inherited from different social fields, whereas in Afghanistan, securitising actors converge from different habitus (e.g., institutions, professions, backgrounds) to bar the ‘other’ ethnic or social groups from resources and spaces which could empower these groups to become a pertinent threat, a fear, and a danger to the monopoly of the state elites over the state power and resources. The most prominent securitisation practices emerging from the data include mainly (1) the obstruction of the formation of critical ideas and politics; (2) the obstruction of economic opportunities; and (3) the obstruction of social justice. This article deploys a case study methodology and uses the Kabul University as its subject of investigation.
Citizenship Education for Political Engagement: A Systematic Review of Controlled Trials
Authors: Donbavand Steven , Hoskins Bryony
Published: April 2021

Citizenship Education could play a pivotal role in creating a fairer society in which all groups participate equally in the political progress. But strong causal evidence of which educational techniques work best to create political engagement is lacking. This paper presents the results of a systematic review of controlled trials within the field based on transparent search protocols. It finds 25 studies which use controlled trials to test causal claims between Citizenship Education programs and political engagement outcomes. The studies identified largely confirm accepted ideas, such as the importance of participatory methods, whole school approaches, teacher training, and doubts over whether knowledge alone or online engagement necessarily translate into behavioral change. But the paucity of identified studies also points both to the difficulties of attracting funding for controlled trials which investigate Citizenship Education as a tool for political engagement and real epistemological tensions within the discipline itself.
External Carbon Source Facilitates Indirect Cr (VI) Bioreduction Process by Anaerobic Sludge Produced from Kitchen Waste
Authors: Han Hui , Hou Jinju , Zhang Dalei , Zhong Yuanning , Chen Chao , Zhang Qiuzhuo
Published: April 2021

This study presented the investigation on indirect Cr (VI) bioreduction process by anaerobic sludge produced from kitchen waste (ASKW) using an external source of glucose and sulfate to favor the reducing environment. These compounds were added at the beginning of the experiment along with 500 mg·L−1 Cr (VI). The system containing 1 g of glucose and 2 g of sulfate attained a higher reduction, which was 10% higher than that of the control experiment. This study indicated that a neutral environment (pH ~7), along with a high release of polysaccharides (PS), improved the removal efficiency by Cr (VI) bioreduction process. Desulfovibrio and Sulfurospirillum (genus level), which accounted for 3% and 1% of the whole microorganism, respectively, were responsible for the sulfidogenic reaction. Additionally, Thermovirga (genus level) reduced from 14% to 11% and 10%. These microorganisms contributed to dominating the indirect Cr (VI) bioreduction process. SEM and FTIR analysis of the sludges obtaining from the indirect Cr (VI) bioreduction systems indicated that the external glucose could facilitate the formation of looser porous structures and richer functional groups of sludges, thus adsorbing more Cr (III) to reduce its toxicity. Meanwhile, the intensity of the hydroxyl bond, which possesses strong reducibility, was much higher after adding external glucose. Chromate reductase gene (chrR) and sulfite reductase gene (dsrA) contributed to the indirect Cr (VI) bioreduction process. These might be the main mechanisms of the external glucose acting on indirect Cr (VI) bioreduction by ASKW.
Putting It All Together: Combining Learning Analytics Methods and Data Sources to Understand Students’ Approaches to Learning Programming
Authors: López-Pernas Sonsoles , Saqr Mohammed , Viberg Olga
Published: April 2021

Learning programming is a complex and challenging task for many students. It involves both understanding theoretical concepts and acquiring practical skills. Hence, analyzing learners’ data from online learning environments alone fails to capture the full breadth of students’ actions if part of their learning process takes place elsewhere. Moreover, existing studies on learning analytics applied to programming education have mainly relied on frequency analysis to classify students according to their approach to programming or to predict academic achievement. However, frequency analysis provides limited insights into the individual time-related characteristics of the learning process. The current study examines students’ strategies when learning programming, combining data from the learning management system and from an automated assessment tool used to support students while solving the programming assignments. The study included the data of 292 engineering students (228 men and 64 women, aged 20–26) from the two aforementioned sources. To gain an in-depth understanding of students’ learning process as well as of the types of learners, we used learning analytics methods that account for the temporal order of learning actions. Our results show that students have special preferences for specific learning resources when learning programming, namely, slides that support search, and copy and paste. We also found that videos are relatively less consumed by students, especially while working on programming assignments. Lastly, students resort to course forums to seek help only when they struggle.
Within-Host and Between-Host Evolution in SARS-CoV-2—New Variant’s Source
Authors: Moelling Karin
Published: April 2021

Some of the newly emerging corona viral variants show high numbers of mutations. This is unexpected for a virus with a low mutation rate due to an inherent proof-reading system. Could such a variant arise under very special conditions occurring in a host where the virus replicates and mutates in a rather unlimited fashion, such as in immune compromised patients? The virus was shown to replicate in an immunosuppressed cancer patient for more than 105 days and might be a source of new variants. These patients are asymptomatic and the virus may therefore escape detection and attention and be high-risk. Similarly, HIV-infected individuals may be immunocompromised and support coronavirus replication with increased mutation rates. The patients may promote “within-host evolution”. Some of the viruses present in such a highly mutagenic swarm or quasispecies within one patient may become founders and cause a pandemic by further “between-host evolution”. B.1.1.7 with 23 mutations may be such a case. Immunosuppressed patients can be identified and treated by the synthetic antibody cocktails as passive immunization and kept under control. Immunosuppressed patients can be easily identified and supervised by healthcare workers—once they become aware of the risk—to avoid new variants with pandemic potential.
Evaluation of Galdieria sulphuraria and Chlorella vulgaris for the Bioremediation of Produced Water
Authors: Rahman Ashiqur , Pan Shanglei , Houston Cymone , Selvaratnam Thinesh
Published: April 2021

Produced water (PW) is the largest waste stream generated by the oil and gas industry. Traditional treatment of PW burdens the industry with significant expenses and environmental issues. Alternatively, microalgal-based bioremediation of PW is often viewed as an ecologically safe and sustainable platform for treating PW. Moreover, the nutrients in PW could support algal growth. However, significant dilution of PW is often required in algal-based systems due to the presence of complex chemical contaminants. In light of these facts, the current work has investigated the potential of cultivating Galdieria sulphuraria and Chlorella vulgaris in PW using multiple dilutions; 0% PW, 5% PW, 10% PW, 20% PW, 50% PW and 100% PW. While both algal strains can grow in PW, the current results indicated that G. sulphuraria has a higher potential of growth in up to 50% PW (total dissolved solids of up to 55 g L−1) with a growth rate of 0.72 ± 0.05 g L−1 d−1 and can achieve a final biomass density of 4.28 ± 0.16 g L−1 in seven days without the need for additional micronutrients. Additionally, the algae showed the potential of removing 99.6 ± 0.2% nitrogen and 74.2 ± 8.5% phosphorus from the PW.
Turning Pools in Stepped Fishways: Biological Assessment via Fish Response and CFD Models
Authors: Bravo-Córdoba Francisco Javier , Fuentes-Pérez Juan Francisco , Valbuena-Castro Jorge , Martínez de Azagra-Paredes Andrés , Sanz-Ronda Francisco Javier
Published: April 2021

With the aim of building more compact fishways and adapting them to field conditions to improve their location by fish, it is common to use turning pools, reducing the longitudinal development of the construction. However, depending on their design, turning pools may affect the hydraulic performance of the fishway and consequently the fish passage. To study these phenomena, turning pools in a vertical slot and in different configurations of submerged notches with bottom orifice fishway types were assessed. Both types of fishways were studied using numerical 3D models via OpenFOAM, a computational fluid dynamics software, in combination with fish responses, assessed with PIT (Passive Integrated Transponder) tag telemetry for three different species of potamodromous cyprinids in several fishways. Results show differences between the hydrodynamics of straight and turning pools, with lower values in the hydrodynamic variables in turning pools. Regarding fish behavior, the ascent was slower in turning pools but with no effect on passage success and without being a problem for fish migration. This information validates the use of turning pools as a key design component for fishways for studied species.
Removal of Pathogens in Onsite Wastewater Treatment Systems: A Review of Design Considerations and Influencing Factors
Authors: Wang Mian , Zhu Julia , Mao Xinwei
Published: April 2021

Conventional onsite wastewater treatment systems (OWTSs) could potentially contribute to the transmission of infectious diseases caused by waterborne pathogenic microorganisms and become an important human health concern, especially in the areas where OWTSs are used as the major wastewater treatment units. Although previous studies suggested the OWTSs could reduce chemical pollutants as well as effectively reducing microbial contaminants from onsite wastewater, the microbiological quality of effluents and the factors potentially affecting the removal are still understudied. Therefore, the design and optimization of pathogen removal performance necessitate a better mechanistic understanding of the hydrological, geochemical, and biological processes controlling the water quality in OWTSs. To fill the knowledge gaps, the sources of pathogens and common pathogenic indicators, along with their major removal mechanisms in OWTSs were discussed. This review evaluated the effectiveness of pathogen removal in state-of-art OWTSs and investigated the contributing factors for efficient pathogen removal (e.g., system configurations, filter materials, environmental and operational conditions), with the aim to guide the future design for optimized treatment performance.
Emprendimiento de una microempresa turística (parada turística), en el municipio San Diego, estado Carabobo
Authors: Carrillo Yamilett
Published: April 2021

La presente investigación tiene como objetivo proponer un plan de emprendimiento para la creación de una microempresa turística, en el sector turismo (parada turística), en el Remanso Municipio San Diego, estado Carabobo. Metodológicamente es una investigación no experimental, de carácter descriptivo y trabajo de campo; La población está conformada por 2.150 habitantes, con una muestra aleatoria de 45 habitantes de la zona, a la cual se les aplicaron cuestionarios y entrevista para la recolección de la información. A partir de esta se obtuvieron los siguientes resultados: la población residente opina que el turismo es una actividad que debe ser desarrollada en el municipio, pero que hay que mejorarla; en este sentido se propone la creación de la parada turística “El Remanso” como una microempresa comercial y de servicio, que asegure empleo directo e indirecto, orientada en una actividad prioritaria para el país en los actuales momentos.
Búsquedas de vínculos eróticos y/o afectivos a través de las apps. Un estudio comparado entre la Ciudad de Buenos Aires y la Ciudad de México
Authors: Palumbo Mariana
Published: April 2021

El artículo analiza, desde un enfoque cualitativo y de corte comparativo, por qué mujeres y varones heterosexuales adultas de clase media residentes de la Ciudad de Buenos Aires y de México eligen a las aplicaciones de citas, en este caso Tinder, como el espacio de sociabilidad a partir del cual llevar a cabo encuentros eróticos y/o afectivos. Para tal fin se describen y analizan: a) cuáles son las motivaciones – facilidades propias de la aplicación y aquellas de índole erótica y/o afectiva– que lleva a sus usuarios/as a utilizar Tinder; b) el uso geolocalizado que la aplicación ofrece: dónde sus usuarios/as la usan, cuáles son sus márgenes espaciales de búsqueda y cuál es su uso en otros países si los hubiera; c) el papel de las mujeres como consumidoras de las aplicaciones virtuales de citas.