bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Analysis of A Soybean Ferredoxin-NADP Reductase (FNR) Gene in Response to Soybean Mosaic Virus
Authors: Shen Yingchao , Karthikeyan Adhimoolam , Yang Yunhua , Ma Na , Yin Jinlong , Yuan Yuan , Wang Liqun , Zhi Haijian
Published: August 2021

The Ferredoxin-NADP reductase (FNR) gene plays a significant role in NADPH production, carbon assimilation, antioxidation, and cross-talking between chloroplasts and mitochondria in plants. This study aims to know the functional response of the soybean FNR gene (GmFNR) during a soybean mosaic virus (SMV) infection. For this purpose, we developed the bean pod mottle virus (BPMV)-based gene construct (BPMV-GmFNR) and used it to silence the GmFNR gene in resistant and susceptible lines. The results showed that GmFNR expression decreased to 50% in the susceptible line, compared to 40% in the resistant line. The silencing of GmFNR reduces the photosynthetic capacity and CAT activity of both lines compared to their respective controls. In addition, the H2O2 content increased significantly in the susceptible line, whereas the resistant line did not exhibit any change. Further, an SMV infection in the silencing plants of the susceptible line resulted in serious morphological changes and increased the SMV NIa-protease transcript accumulation compared to its control plants. However, the same impact was not observed in the resistant line. The yeast two-hybrid system, BIFC assay, and quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that the GmFNR was interacting with EF1A and coincided with the increased SMV accumulation. The results obtained in this study improve the understanding of the soybean FNR gene response during SMV infection and provide a novel insight into the SMV resistance mechanism.
Toxic Elements in Soil and Rice in Ecuador
Authors: Atiaga Oliva , Ruales Jenny , Nunes Luís Miguel , Otero Xosé Luis
Published: August 2021

The concentration of trace toxic metals (Cr, Zn, As, Pb, Cd, Cu, and Ni) in soil and rice plants, including the stems, leaves, and grain, from the main rice-producing provinces in Ecuador, was determined. Additionally, the soils were analyzed to determine their properties, composition, total content, bioavailable fraction, and geochemical fractions of toxic elements. Approximately 30% of soil samples in the case of Cr and Cu and 10% of samples in the case of Ni exceeded the legal thresholds for Ecuador. Moreover, for Cr and Cu, approximately 4% and 13% of samples, respectively, exceeded the threshold value of 100 mg kg−1 proposed for these two elements in several international regulations. Concentrations of As, Pb, and Cd in the soils were below the threshold values established both by Ecuadorian laws and by other countries. The concentrations of metals in rice plants did not correlate linearly with the total metal concentrations in the soil, nor with their bioavailability. However, the bioconcentration factors for As, Cd, Cu, Ni, and Zn could be predicted from bioavailability by a power law with exponents ranging from −0.724 to −1.625, which is typical of accumulator plants, where trace metal homeostasis plays an important role.
Lime and Organic Manure Amendment Enhances Crop Productivity of Wheat–Mungbean–T. Aman Cropping Pattern in Acidic Piedmont Soils
Authors: Islam Mohammad Rafiqul , Jahan Rounok , Uddin Shihab , Harine Israt Jahan , Hoque Mohammad Anamul , Hassan Sabry , Hassan Mohamed M. , Hossain Mohammad Anwar
Published: August 2021

Soil acidity is a major problem when it comes to improving crop productivity and nutrient uptake. This experiment was therefore conducted at a farmer’s field—Nalitabari Upazila under AEZ 22 (northern and eastern Piedmont plains) to evaluate the effects of lime and organic manure (OM) amendment on crop productivity and nutrient uptake of the wheat–mungbean–T. Aman cropping pattern in acidic soils of northern and eastern Piedmont plains. The experiment was laid out in a randomized complete block design with three replications. There were nine treatments applied, varying doses of lime (dololime at the rate of 1 and 2 t ha−1), OM (cow dung at the rate of 5 t ha−1, poultry manure at the rate of 3 t ha−1) and a lime–OM combination to the first crop; T. Aman and its residual effects were evaluated in the succeeding second crop, wheat, and the third crop, mungbean. Results demonstrate that application of lime and organic manure to soil had significant effects on the first crop. However, the effects of lime and organic manure were more pronounced in the second and third crops. The increase in grain yield over control ranged from 0.24 to 13.44% in BINA dhan7. However, it varied from 10.14 to 54.38% in BARI Gom30 and 40 to 161.67% in BARI Mung6. The straw yields of the crops also followed a similar trend. The N, P, K, and S uptake by grain and straw of T. Aman, wheat, and mungbean were influenced significantly by the combined application of lime and organic manure. Sole or combined application of lime and manure amendment significantly improved nutrient availability and soil quality. Therefore, application of lime in combination with manure can be practiced for uplifting the crop productivity and improving soil quality in acidic Piedmont soils of northern and eastern Piedmont plains.
Effect of Lactobacillus plantarum Biofilms on the Adhesion of Escherichia coli to Urinary Tract Devices
Authors: Carvalho Fábio M. , Teixeira-Santos Rita , Mergulhão Filipe J. M. , Gomes Luciana C.
Published: August 2021

Novel technologies to prevent biofilm formation on urinary tract devices (UTDs) are continually being developed, with the ultimate purpose of reducing the incidence of urinary infections. Probiotics have been described as having the ability to displace adhering uropathogens and inhibit microbial adhesion to UTD materials. This work aimed to evaluate the effect of pre-established Lactobacillus plantarum biofilms on the adhesion of Escherichia coli to medical-grade silicone. The optimal growth conditions of lactobacilli biofilms on silicone were first assessed in 12-well plates. Then, biofilms of L. plantarum were placed in contact with E. coli suspensions for up to 24 h under quasi-static conditions. Biofilm monitoring was performed by determining the number of culturable cells and by confocal laser scanning microscopy (CLSM). Results showed significant reductions of 76%, 77% and 99% in E. coli culturability after exposure to L. plantarum biofilms for 3, 6 and 12 h, respectively, corroborating the CLSM analysis. The interactions between microbial cell surfaces and the silicone surface with and without L. plantarum biofilms were also characterized using contact angle measurements, where E. coli was shown to be thermodynamically less prone to adhere to L. plantarum biofilms than to silicone. Thus, this study suggests the use of probiotic cells as potential antibiofilm agents for urinary tract applications.
Isoorientin Attenuated the Pyroptotic Hepatocyte Damage Induced by Benzo[a]pyrene via ROS/NF-κB/NLRP3/Caspase-1 Signaling Pathway
Authors: Li Hao , Yuan Li , Li Xueyi , Luo Ying , Zhang Zhong , Li Jianke
Published: August 2021

Isoorientin (Iso), a natural bioactive flavonoid, possesses significant anti-tumor and anti-oxidant activities. Benzo[a]pyrene (BaP) is a food processing injurant with carcinogenicity, teratogenicity, and genotoxicity. Our preliminary study demonstrates that Iso attenuated the pyroptotic hepatocyte damage induced by BaP; however, the molecular mechanism remains unknown. The present study showed that Iso reduced the increase caused by BaP in the overflow of LDH, NO, and the electrical conductivity and the protein expressions of GSDMD-N, IL-18, and IL-1β, further showing that Iso could reduced the pyroptotic damage in HL-7702 cells induced by BaP. Caspase-1 inhibitor (Z-VAD-FMK) inhibited the characteristic pyroptosis protein expressions of Caspase-1, GSDMD-N, IL-18, and IL-1β, showing that the classic pyroptosis pathway depending on Caspase-1 was caused by BaP in HL-7702 cells. Consistent with the effects of the NLRP3 inhibitor (MCC950), NF-κB inhibitor (PDTC), ROS, and mtROS inhibitor (NAC and Mito-TEMPO), Iso weakened the stimulatory effects of BaP on the levels of ROS, the nuclear localization of NF-κB, and the activation of NLRP3 inflammasome and the characteristic indices of pyroptosis, demonstrating that Iso could alleviate the BaP-induced pyroptotic hepatocytes injury through inhibiting the ROS/NF-κB/NLRP3/Caspase-1 signaling pathway, which provides a new perspective and strategy to prevent liver injury induced by BaP.
Enhanced Tunability of BaTixSn1−xO3 Films on Dielectric Substrate
Authors: Tumarkin Andrey , Sapego Evgeny , Gagarin Alexander , Senkevich Stanislav
Published: August 2021

The structural properties of ferroelectric films of barium titanate-stannate on alumina substrates and the microwave characteristics of planar capacitive elements based on them are studied. It is established that the composition of the gas medium and the temperature of the substrate during the deposition of the film has a significant effect on the crystal structure, phase composition of the films and their electrical characteristics. Planar capacitors based on films subjected to high-temperature annealing after deposition exhibit 85% tunability at a frequency of 2 GHz, which is the best result for today.
Establishment of a Geographic Information System-Based Algorithm to Analyze Suitable Locations for Green Roofs and Roadside Trees
Authors: Kim Heeju , Oh Kyushik , Lee Dongwoo
Published: August 2021

Urban green spaces offer various ecosystem services such as those for controlling the urban microclimate, improving water circulation, and providing leisure and recreation opportunities. However, it is almost impossible to create new, large green spaces in cities where urbanization has been long underway. Consequently, small-scale green spaces such as green roofs and roadside trees are gaining attention as features that can increase the effects of ecosystem services. Although the area of individual buildings in urban areas is relatively small, the sum of building rooftop areas account for a large portion of urban areas. Moreover, there are areas widely available throughout cities where street trees could be planted. However, this requires large amounts of accurate databases (DBs) and long-term spatial analyses to identify specific locations suitable for small-scale green facilities on a citywide scale using a geographic information system (GIS). Consequently, in-depth research on this topic has been insufficient. Thus, this study presents an algorithm to analyze locations where green roofs and roadside trees could be introduced based on GIS spatial analysis and verifies the effectiveness of the algorithm built for the city of Seoul. In addition, computational fluid dynamics (CFD) modeling is performed to analyze the temperature reduction effect, the representative function of ecosystem control services that can be brought about by the potential green spaces. The results show that rooftop greening in study areas is possible in 311,793 of 742,770 buildings. The rooftop floor area of buildings that can apply rooftop greening is 33,288,745 m2, which is about 50% of the total area of the rooftop in Seoul. It was found that roadside trees could be planted on a sidewalk with an extension length of 872,725 m and an area of 838,864 m2. A total of 145,366 trees can be planted in the study area. In addition, it was shown that the introduction of green roofs reduced temperatures by 0.13 °C to 0.14 °C and roadside trees reduced temperatures by 0.14 °C to 0.6 °C. With the growing need to improve urban ecosystem services as a result of rapid climate change, the algorithm developed in this study can be utilized to create spatial policies that expand and manage urban green spaces and thereby contribute to the improvement of urban ecosystem services.
Presence of Systemic Amyloidosis in Mice with Partial Deficiency in Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in Aging
Authors: Sparks Jason , Jungling Adel , Kiss Gabriella , Hiripi Laszlo , Pham Daniel , Tamas Andrea , Hoffmann Orsolya , Bardosi Sebastian , Miseta Attila , Reglodi Dora
Published: August 2021

Pituitary adenylate cyclase-activating polypeptide (PACAP), a neuropeptide with widespread expression and general cytoprotective effects, is also involved in aging. Previously, we observed accelerated systemic senile amyloidosis in PACAP knockout (KO) mice. As mice partially lacking PACAP (heterozygous-HZ) show variable symptoms, here we investigated whether HZ mice have accelerated aging, completed with observations in PAC1 receptor KO mice. As we have limited data on qualitative or quantitative changes in the blood of PACAP-deficient mice, we investigated whether these changes could be in the background of the amyloidosis. Routine histological staining was used to examine amyloid deposits, rated on a severity scale 0–3. Blood was collected from PACAP wild type/HZ mice for complete blood analysis. In contrast to receptor KO mice showing no amyloidosis, histopathological analysis revealed severe deposits in PACAP HZ mice, with kidney, spleen, skin, and intestines being most affected. Increased cholesterol, lipoprotein levels, and differences in several blood count parameters were found in HZ mice. In summary, amyloidosis also develops in partial absence of PACAP, in contrast to the lack of its PAC1 receptor. In addition to the earlier identified inflammatory and degenerative disturbances, the alteration in lipid metabolism and bone marrow activity can also be additional factors leading to systemic degenerative processes.
Adaptable and Explainable Predictive Maintenance: Semi-Supervised Deep Learning for Anomaly Detection and Diagnosis in Press Machine Data
Authors: Serradilla Oscar , Zugasti Ekhi , Ramirez de Okariz Julian , Rodriguez Jon , Zurutuza Urko
Published: August 2021

Predictive maintenance (PdM) has the potential to reduce industrial costs by anticipating failures and extending the work life of components. Nowadays, factories are monitoring their assets and most collected data belong to correct working conditions. Thereby, semi-supervised data-driven models are relevant to enable PdM application by learning from assets’ data. However, their main challenges for application in industry are achieving high accuracy on anomaly detection, diagnosis of novel failures, and adaptability to changing environmental and operational conditions (EOC). This article aims to tackle these challenges, experimenting with algorithms in press machine data of a production line. Initially, state-of-the-art and classic data-driven anomaly detection model performance is compared, including 2D autoencoder, null-space, principal component analysis (PCA), one-class support vector machines (OC-SVM), and extreme learning machine (ELM) algorithms. Then, diagnosis tools are developed supported on autoencoder’s latent space feature vector, including clustering and projection algorithms to cluster data of synthetic failure types semi-supervised. In addition, explainable artificial intelligence techniques have enabled to track the autoencoder’s loss with input data to detect anomalous signals. Finally, transfer learning is applied to adapt autoencoders to changing EOC data of the same process. The data-driven techniques used in this work can be adapted to address other industrial use cases, helping stakeholders gain trust and thus promote the adoption of data-driven PdM systems in smart factories.
Performance of Communication- and Computation-Intensive SaaS on the OpenStack Cloud
Authors: Bystrov Oleg , Pacevič Ruslan , Kačeniauskas Arnas
Published: August 2021

The pervasive use of cloud computing has led to many concerns, such as performance challenges in communication- and computation-intensive services on virtual cloud resources. Most evaluations of the infrastructural overhead are based on standard benchmarks. Therefore, the impact of communication issues and infrastructure services on the performance of parallel MPI-based computations remains unclear. This paper presents the performance analysis of communication- and computation-intensive software based on the discrete element method, which is deployed as a service (SaaS) on the OpenStack cloud. The performance measured on KVM-based virtual machines and Docker containers of the OpenStack cloud is compared with that obtained by using native hardware. The improved mapping of computations to multicore resources reduced the internode MPI communication by 34.4% and increased the parallel efficiency from 0.67 to 0.78, which shows the importance of communication issues. Increasing the number of parallel processes, the overhead of the cloud infrastructure increased to 13.7% and 11.2% of the software execution time on native hardware in the case of the Docker containers and KVM-based virtual machines of the OpenStack cloud, respectively. The observed overhead was mainly caused by OpenStack service processes that increased the load imbalance of parallel MPI-based SaaS.
Numerical Characterization of the Solid Particle Accumulation in a Turbulent Flow through Curved Pipes by Means of Stokes Numbers
Authors: Henríquez Lira Santiago , Torres María Josefina , Guerra Silva Rafael , Zahr Viñuela Jorge
Published: August 2021

The accumulation of particles in a turbulent flow of incompressible air with mono-dispersed solid particles inside a 90° pipe bend was simulated using ANSYS® Fluent (CFD), taking into account the effect of gravity, drag force and a bidirectional fluid-particle coupling. An analysis of the geometrical parameters and the structures of the secondary flow generated in a curved pipe (Dean vortices) was developed, thus determining the characteristic time scales of the flow. Four Stokes numbers (Stk) were formulated, whose values are calculated and studied from the numerical simulations performed. Two different particle sizes (d1 = 50 μm y d2 = 150 μm), at two different flow conditions (Re1 = 61,500 y Re2 = 173,972), and for three curvature ratios Rc/R = 1, 4 and 8 were studied. The flow was solved using a Eulerian–Lagrangian approach with a RNG k-ε turbulence model. Once the multiphase flow was solved and validated, the distribution and maximum particle concentration inside the 90° bend were presented. Additionally, the Stk numbers were calculated to estimate the possible particle concentration level for the different system configurations (dp, Re and Rc/R). It is concluded that, if all Stk numbers are less than one, relative concentration levels reach a minimum, while for Stk numbers larger than one, an increase in the maximum concentration inside the pipe bend was noticed.
The Relationship between Mitochondria and Neurodegeration in the Eye: A Review
Authors: Liu Hongtao , Liu Hanhan , Prokosch Verena
Published: August 2021

Mitochondria are the energy factories of cells. Mitochondrial dysfunction directly affects the function and morphology of cells. In recent years, growing evidence has shown that mitochondrial dysfunction plays an important role in neurodegenerative diseases. In the eye, some age-related diseases are considered to be neurodegenerative diseases, such as primary open-angle glaucoma (POAG) and age-related macular degeneration (AMD). Here, we review the mechanisms of mitochondrial damage, post-injury repair, and the roles of mitochondria in various tissues of the eye. In the following sections, the potential for treating glaucoma by reducing mitochondrial damage and promoting post-injury repair is also discussed.
Flabby Ridge, a Challenge for Making Complete Dentures
Authors: Ştefănescu Corina-Laura , Zaharia Agripina , Murineanu Rodica Maria , Puşcaşu Cristina Gabriela , Sachelarie Liliana , Grigorian Mircea
Published: August 2021

In the case of old mobile denture wearers, one of the main problems is related to the dentures’ retention and insufficient stability. Our goal was to improve support and stability using a different type of final impression, with different types of impression materials. In this study we chose a number of three complete edentulous patients who presented for complete oral rehabilitation. They were wearing full acrylic dentures with poor support and stability. Complete examination revealed the presence of the flabby ridge. The impression methods for the prosthetic fields with a flabby ridge differ from the classical method by using techniques that involve the use of at least two impression materials with fluid consistency to record all the details of the prosthetic fields in the final impression, this being done in two steps; the impression of the flabby ridge areas must be done without pressure, in its resting position. The impression methods we applied led to the expected results, and the dentures succeeded in offering the patient the desired functional comfort. Using fluid impression material for the flabby ridge in a resting position, and a fenestrated custom tray, offered a good quality in adaptation, maintenance and stability of the final dentures.
Simulations between Network Topologies in Networks of Evolutionary Processors
Authors: Sánchez Martín José Ángel , Mitrana Victor
Published: August 2021

In this paper, we propose direct simulations between a given network of evolutionary processors with an arbitrary topology of the underlying graph and a network of evolutionary processors with underlying graphs—that is, a complete graph, a star graph and a grid graph, respectively. All of these simulations are time complexity preserving—namely, each computational step in the given network is simulated by a constant number of computational steps in the constructed network. These results might be used to efficiently convert a solution of a problem based on networks of evolutionary processors provided that the underlying graph of the solution is not desired.
Mechanisms of Flexible Information Sharing through Noisy Oscillations
Authors: Powanwe Arthur S. , Longtin Andre
Published: August 2021

Brain areas must be able to interact and share information in a time-varying, dynamic manner on a fast timescale. Such flexibility in information sharing has been linked to the synchronization of rhythm phases between areas. One definition of flexibility is the number of local maxima in the delayed mutual information curve between two connected areas. However, the precise relationship between phase synchronization and information sharing is not clear, nor is the flexibility in the face of the fixed structural connectivity and noise. Here, we consider two coupled oscillatory excitatory-inhibitory networks connected through zero-delay excitatory connections, each of which mimics a rhythmic brain area. We numerically compute phase-locking and delayed mutual information between the phases of excitatory local field potential (LFPs) of the two networks, which measures the shared information and its direction. The flexibility in information sharing is shown to depend on the dynamical origin of oscillations, and its properties in different regimes are found to persist in the presence of asymmetry in the connectivity as well as system heterogeneity. For coupled noise-induced rhythms (quasi-cycles), phase synchronization is robust even in the presence of asymmetry and heterogeneity. However, they do not show flexibility, in contrast to noise-perturbed rhythms (noisy limit cycles), which are shown here to exhibit two local information maxima, i.e., flexibility. For quasi-cycles, phase difference and information measures for the envelope-phase dynamics obtained from previous analytical work using the Stochastic Averaging Method (SAM) are found to be in good qualitative agreement with those obtained from the original dynamics. The relation between phase synchronization and communication patterns is not trivial, particularly in the noisy limit cycle regime. There, complex patterns of information sharing can be observed for a single value of the phase difference. The mechanisms reported here can be extended to I-I networks since their phase synchronizations are similar. Our results set the stage for investigating information sharing between several connected noisy rhythms in neural and other complex biological networks.
Development and Evaluation of Gellan Gum/Silk Fibroin/Chondroitin Sulfate Ternary Injectable Hydrogel for Cartilage Tissue Engineering
Authors: Lee Seongwon , Choi Joohee , Youn Jina , Lee Younghun , Kim Wooyoup , Choe Seungho , Song Jeongeun , Reis Rui L. , Khang Gilson
Published: August 2021

Hydrogel is in the spotlight as a useful biomaterial in the field of drug delivery and tissue engineering due to its similar biological properties to a native extracellular matrix (ECM). Herein, we proposed a ternary hydrogel of gellan gum (GG), silk fibroin (SF), and chondroitin sulfate (CS) as a biomaterial for cartilage tissue engineering. The hydrogels were fabricated with a facile combination of the physical and chemical crosslinking method. The purpose of this study was to find the proper content of SF and GG for the ternary matrix and confirm the applicability of the hydrogel in vitro and in vivo. The chemical and mechanical properties were measured to confirm the suitability of the hydrogel for cartilage tissue engineering. The biocompatibility of the hydrogels was investigated by analyzing the cell morphology, adhesion, proliferation, migration, and growth of articular chondrocytes-laden hydrogels. The results showed that the higher proportion of GG enhanced the mechanical properties of the hydrogel but the groups with over 0.75% of GG exhibited gelling temperatures over 40 °C, which was a harsh condition for cell encapsulation. The 0.3% GG/3.7% SF/CS and 0.5% GG/3.5% SF/CS hydrogels were chosen for the in vitro study. The cells that were encapsulated in the hydrogels did not show any abnormalities and exhibited low cytotoxicity. The biochemical properties and gene expression of the encapsulated cells exhibited positive cell growth and expression of cartilage-specific ECM and genes in the 0.5% GG/3.5% SF/CS hydrogel. Overall, the study of the GG/SF/CS ternary hydrogel with an appropriate content showed that the combination of GG, SF, and CS can synergistically promote articular cartilage defect repair and has considerable potential for application as a biomaterial in cartilage tissue engineering.
Novel Insight of Histamine and Its Receptor Ligands in Glaucoma and Retina Neuroprotection
Authors: Sgambellone Silvia , Lucarini Laura , Lanzi Cecilia , Masini Emanuela
Published: August 2021

Glaucoma is a multifactorial neuropathy characterized by increased intraocular pressure (IOP), and it is the second leading cause of blindness worldwide after cataracts. Glaucoma combines a group of optic neuropathies characterized by the progressive degeneration of retinal ganglionic cells (RGCs). Increased IOP and short-term IOP fluctuation are two of the most critical risk factors in glaucoma progression. Histamine is a well-characterized neuromodulator that follows a circadian rhythm, regulates IOP and modulates retinal circuits and vision. This review summarizes findings from animal models on the role of histamine and its receptors in the eye, focusing on the effects of histamine H3 receptor antagonists for the future treatment of glaucomatous patients.
A Conceptual Model of Multi-Spectra Perceptions for Enhancing the Safety Climate in Construction Workplaces
Authors: Kim Sungjin , Song Siyuan , Lee Donghoon , Kim Daeyoung , Lee Sangsoo , Irizarry Javier
Published: August 2021

Construction safety climates can reflect organizational safety behavior and commitment, employees’ safety perceptions and attitudes, and the supervisory and support environments. Maintaining a healthy safety climate can help prevent workers from fatal accidents and illnesses. To enhance the safety climate and, consequently, improve safety performance at a construction site, it is very important to analyze the elements that affect the safety climate and are significant for different types of construction work organizations. Therefore, the main goal of this study was to develop a multi-spectra perception model to investigate which factors were considered critical from four key perspectives: managers, superintendents, skilled laborers, and general helpers. To achieve this goal, a survey questionnaire was conducted to collect empirical data from one commercial building construction project. Based on a stepwise regression analysis, it was revealed that the most significant factors enhancing the safety climate are: from the managers’ perspective, a combination of improvement in the support environment and reduction in work pressure; for superintendents and skilled laborers, increasing worker competence; and for general laborers, increasing worker involvement. This research contributes to a better understanding of the significant factors and provides a measure for each important role in enhancing the safety climate at a job site.
Propylene Polymerization and Deactivation Processes with Isoselective {Cp/Flu} Zirconocene Catalysts
Authors: Desert Xavier , Roisnel Thierry , Dorcet Vincent , Den Dauw Katty , Vantomme Aurélien , Welle Alexandre , Carpentier Jean-François , Kirillov Evgueni
Published: August 2021

Industrially relevant single-site precatalysts used to produce isotactic polypropylene (iPP) include C2-symmetric {SBI} and C1-symmetric {Cp/Flu} complexes of group 4 metals. While the latter can produce iPPs with a higher degree of isotacticity, they also suffer from poor productivity compared to their {SBI} counterparts. Several causes for this trend have been suggested—2,1-Regioinsertions are frequently pointed out, as they are suspected to drive the catalyst into a dormant state. While this event does not seem to significantly impact the productivity of {SBI} systems, the influence of these regioerror is poorly documented for isoselective {Cp/Flu} precatalysts. To address this issue, new Ph2X(Cp)(Flu) (Ph2X = Ph2C, FluC, Ph2Si) proligands (2a–k) and some of the corresponding dichlorozirconocenes (3a–h,k) were synthesized. These new compounds were characterized and tested in homogeneous propylene polymerization at 60 °C and the amounts of regioerrors in the resulting polymers were examined by 13C NMR spectroscopy. A possible correlation between poor productivity and a high number of regioerrors was investigated and is discussed. Furthermore, a C-H activation process in the bulky nBu3C substituent upon activation of 4c (the dimethylated analog of 3c) by B(C6F5)3 has been evidenced by NMR; DFT calculations support this C-H activation as a deactivation mechanism.
Terpolymerization of CO2 with Epoxides and Cyclic Organic Anhydrides or Cyclic Esters
Authors: Lamparelli David Hermann , Capacchione Carmine
Published: August 2021

The synthesis of polymeric materials starting from CO2 as a feedstock is an active task of research. In particular, the copolymerization of CO2 with epoxides via ring-opening copolymerization (ROCOP) offers a simple, efficient route to synthesize aliphatic polycarbonates (APC). In many cases, APC display poor physical and chemical properties, limiting their range of application. The terpolymerization of CO2 with epoxides and organic anhydrides or cyclic esters offers the possibility, combining the ROCOP with ring-opening polymerization (ROP), to access a wide range of materials containing polycarbonate and polyester segments along the polymer chain, showing enhanced properties with respect to the simple APC. This review will cover the last advancements in the field, evidencing the crucial role of the catalytic system in determining the microstructural features of the final polymer.
Use of a Sequential Fermentation Method for the Production of Aspergillus tamarii URM4634 Protease and a Kinetic/Thermodynamic Study of the Enzyme
Authors: de Oliveira Rodrigo Lira , de Souza Claudino Emiliana , Converti Attilio , Porto Tatiana Souza
Published: August 2021

Microbial proteases are commonly produced by submerged (SmF) or solid-state fermentation (SSF), whose combination results in an unconventional method, called sequential fermentation (SF), which has already been used only to produce cellulolytic enzymes. In this context, the aim of the present study was the development of a novel SF method for protease production using wheat bran as a substrate. Moreover, the kinetic and thermodynamic parameters of azocasein hydrolysis were estimated, thus providing a greater understanding of the catalytic reaction. In SF, an approximately 9-fold increase in protease activity was observed compared to the conventional SmF method. Optimization of glucose concentration and medium volume by statistical means allowed us to achieve a maximum protease activity of 180.17 U mL−1. The obtained enzyme had an optimum pH and temperature of 7.0 and 50 °C, respectively. Kinetic and thermodynamic parameters highlighted that such a neutral protease is satisfactorily thermostable at 50 °C, a temperature commonly used in many applications in the food industry. The results obtained suggested not only that SF could be a promising alternative to produce proteases, but also that it could be adapted to produce several other enzymes.
Study on Flexural Performance of Concrete Beams Reinforced by Steel Fiber and Nano–SiO2 Materials
Authors: Shi Ke , Zhang Mengyue , Zhang Tao , Xue Ru , Li Pengfei , Chen Gang
Published: August 2021

Steel fiber and Nano–SiO2 reinforced concrete is a novel material of concrete which has great potential to be used in practical engineering. However, there is relatively little literature available on the flexural behavior of steel fiber and Nano–SiO2 materials reinforced concrete (SFNMRC) beams. Hence, the main objective of this paper is to investigate the flexural performance of SFNMRC beams through combined experimental and theoretical studies. A total of 10 specimens were tested to investigate the flexural behavior and the effect of some key parameters, including concrete strength, the volume fraction of steel fiber, and the amount of Nano–SiO2. The load vs. deflection curves of SFNMRC beams during the whole loading process were analyzed in detail. The failure mode was discussed in detail, and the specimens all behaved in a very ductile manner. Furthermore, the test results indicated that bending cracks and concrete crushing were formed in the compression zone of all specimens. With the increase in concrete strength and the volume fraction of steel fiber, both the cracking load and ultimate load of beams increased. The amount of Nano–SiO2 had a limited effect on the flexure performance. Finally, the calculation formula for predicting the flexural bearing capacity of SFNMRC beams was derived with consideration of the effect of steel fiber on the cracked sections after beam cracking. The predicted results show satisfactory agreement with both experimental results. The studies may provide a considerable reference for designing this type of structure in engineering practice.
Exploring Faculty Perspectives during Emergency Remote Teaching in Engineering at a Large Public University
Authors: Chierichetti Maria , Backer Patricia
Published: August 2021

In Spring 2020, the College of Engineering at San José State University (SJSU) conducted a comprehensive analysis of the impact of COVID-19 on faculty who were forced to transition to an online learning environment. The purpose of this study is to assess the impact of COVID-19 on faculty teaching methods, assessment methods, and personal well-being. The study was a combination of a quantitative survey and a qualitative study using interviews of engineering faculty teaching in Spring 2020. In the first part, we surveyed all faculty teaching during Spring 2020 in the SJSU College of Engineering about their experiences after the move to 100% online instruction in March 2020. In the second part of the research, we interviewed 23 faculty members to obtain a more in-depth understanding of their experiences during the move online in Spring 2020. Overall, 98 faculty participated in the survey: lecturers (58), tenure-track (18), tenured (13), adjunct (1), and Teaching Associates (1). The faculty reported being worried about their family and their students’ well-being. In addition, 65% of faculty members reported either a moderate or a great deal of stress related to the shelter in place, and this percentage was higher for female faculty (74%) and for tenure-track faculty (83%). Overall, faculty members felt that they had their classes under control most of the time and that the transition to online teaching was positive, even if they felt they had too much work to do and felt always in a hurry and under pressure. From a teaching perspective, the interviews highlight that faculty members’ main concerns focus on testing and assessment and students’ engagement. Overall, SJSU College of Engineering faculty members felt under stress in the transition to online teaching, especially the tenure-track faculty members, but were able to transition their classes with ease.
The Role of the Social Sciences When Choosing University Studies: Motivations in Life Stories
Authors: Corrales Serrano Mario , Sánchez-Martín Jesús , Moreno Losada José , Zamora Polo Francisco
Published: August 2021

The motivations that lead students to decide on a study modality or on a university degree provide relevant information to improve teaching–learning processes. This work addresses the question regarding the choice of study through analysis of four particular cases. They are special because the individuals chose their studies according to reasons different from the usual ones. To study these cases, interviews were carried out with the individuals. The results were subsequently analyzed according to a qualitative methodology using WebQDA software. The aim was to distinguish the incidence of internal and external motivations when choosing studies. The results obtained represent a contradiction with other pieces of research that analyzed the incidence of these types of motivations for choosing studies and allow for the assessment of various factors that may influence this process. The results obtained in this research indicate that the participants presented a high incidence of internal motivation. This allows for establishing some conclusions about the nature of those motivations when compared with the standard ones referred to in other works that dealt with a general population. The results reveal that in the subjects of this study’s sample, there is a higher incidence of internal motivational factors, such as vocation, while in other subjects, external factors predominate, such as socioeconomic position.
Intersectional Aspects of Education at the Nexus of Disability and Forced Migration: Perspectives of Parents, Educational Experts, and School Authorities in Greater Vienna
Authors: Subasi Singh Seyda , Pellech Camilla , Gutschik Alexandra , Proyer Michelle , O’Rourke Iris
Published: August 2021

Although Austrian statistics inform about the distribution of students among different school types based on either their special education needs or their (forced) migration background, the group facing the disadvantages of both situations is almost invisible in the national context. There is a lack of data about the intersection of the kind of schooling (integrative setting, inclusive settings, or special education classes), gender, nationality, or first language use. In order to learn about the current educational practices and challenges in the Austrian context, parents of disabled children from a refugee background as well as educational experts and school authorities were interviewed. Findings showed that there is only a little awareness of the intersectional aspects of disability and forced migration among educational experts and school authorities, while the diagnosis of special education needs suffers from the complexity of the situation. Additionally, parents’ lack of information, as well as the need to improve collaboration and increase the availability of translation services, multilingual counseling, or service provision in general were other aspects that this study found. Parents perceived school choice as a key decision and findings underlined that their worries, also as a result of past experiences, affected current decision-making regarding their children’s education.
Knowledge Building in Online Mode: Insights and Reflections
Authors: Soliman Dina , Costa Stacy , Scardamalia Marlene
Published: August 2021

It seems certain that blended learning will be on the rise in higher education, with in-person meetings increasingly precious time, and online synchronous and asynchronous sessions used to complement them. This paper examines Knowledge Building in two graduate courses conducted during the COVID-19 pandemic. There were no in-person sessions; rather, synchronous Zoom sessions were combined with asynchronous work in a knowledge building environment–Knowledge Forum. Knowledge Forum is designed to make transparent and accessible means by which deep understanding and sustained creative work proceed. Accordingly, for example, rise-above notes and view rearrangement support synthesis and explanatory coherence, epistemic markers support knowledge-advancing discourse, and analytics support self-and group-monitoring of progress as work proceeds. In this report, we focus on these aspects of Knowledge Building, using a subset of analytics to enhance understanding of key concepts and design of principles-based practices to advance education for knowledge creation. Overall, we aimed to have students take collective responsibility for advancing community knowledge, rather than focus exclusively on individual achievement. As we reflect on our experiences and challenges, we attempt to answer the following questions: Do courses that introduce Knowledge Building in higher education need an in-person or synchronous component? In what ways can we leverage in-class time and Knowledge Forum work to engage students in more advanced knowledge creation? We conclude that synchronous and asynchronous Knowledge Building can be combined in powerful new ways to provide students with more design time and deeper engagement with content and peers.
AccelSDP: A Reconfigurable Accelerator for Software Data Plane Based on FPGA SmartNIC
Authors: Huang Xiaoying , Guo Zhichuan , Song Mangu , Guo Yunfei
Published: August 2021

Software-defined networking (SDN) has attracted much attention since it was proposed. The architecture of the SDN data plane is also evolving. To support the flexibility of the data plane, the software implementation approach is adopted. The software data plane of SDN is commonly implemented on a commercial off-the-shelf (COTS) server, executing an entire processing logic on a commodity CPU. With sharp increases in network capacity, CPU-based packet processing is overwhelmed. However, completely implementing the data plane on hardware weakens the flexibility. Therefore, hybrid implementation where a hardware device is adopted as the accelerator is proposed to balance the performance and flexibility. We propose an FPGA SmartNIC-based reconfigurable accelerator to offload some of the operation-intensive packet processing functions from the software data plane to reconfigurable hardware, thus improving the overall data plane performance while retaining flexibility. The accelerated software data plane has a powerful line-rate packet processing capability and flexible programmability at 100 Gbps and higher throughput. We offloaded a cached-rule table to the proposed accelerator and tested its performance with 100 GbE traffic. Compared with the software implementation, the evaluation result shows that the throughput can achieve a 600% improvement when processing small packets and a 100% increase in large packet processing, and the latency can be reduced by about 20× and 100×, respectively, when processing small packets and large packets.
Dynamic Target Tracking and Ingressing of a Small UAV Using Monocular Sensor Based on the Geometric Constraints
Authors: Wang Zi-Hao , Chen Wen-Jie , Qin Kai-Yu
Published: August 2021

In many applications of airborne visual techniques for unmanned aerial vehicles (UAVs), lightweight sensors and efficient visual positioning and tracking algorithms are essential in a GNSS-denied environment. Meanwhile, many tasks require the ability of recognition, localization, avoiding, or flying pass through these dynamic obstacles. In this paper, for a small UAV equipped with a lightweight monocular sensor, a single-frame parallel-features positioning method (SPPM) is proposed and verified for a real-time dynamic target tracking and ingressing problem. The solution is featured with systematic modeling of the geometric characteristics of moving targets, and the introduction of numeric iteration algorithms to estimate the geometric center of moving targets. The geometric constraint relationships of the target feature points are modeled as non-linear equations for scale estimation. Experiments show that the root mean square error percentage of static target tracking is less than 1.03% and the root mean square error of dynamic target tracking is less than 7.92 cm. Comprehensive indoor flight experiments are conducted to show the real-time convergence of the algorithm, the effectiveness of the solution in locating and tracking a moving target, and the excellent robustness to measurement noises.
RETRACTED: Road Object Detection: A Comparative Study of Deep Learning-Based Algorithms
Authors: Haris Malik , Glowacz Adam
Published: August 2021

Automated driving and vehicle safety systems need object detection. It is important that object detection be accurate overall and robust to weather and environmental conditions and run in real-time. As a consequence of this approach, they require image processing algorithms to inspect the contents of images. This article compares the accuracy of five major image processing algorithms: Region-based Fully Convolutional Network (R-FCN), Mask Region-based Convolutional Neural Networks (Mask R-CNN), Single Shot Multi-Box Detector (SSD), RetinaNet, and You Only Look Once v4 (YOLOv4). In this comparative analysis, we used a large-scale Berkeley Deep Drive (BDD100K) dataset. Their strengths and limitations are analyzed based on parameters such as accuracy (with/without occlusion and truncation), computation time, precision-recall curve. The comparison is given in this article helpful in understanding the pros and cons of standard deep learning-based algorithms while operating under real-time deployment restrictions. We conclude that the YOLOv4 outperforms accurately in detecting difficult road target objects under complex road scenarios and weather conditions in an identical testing environment.